A hand device for transferring a film, of, for example, adhesive, covering, or colored material, from a backing strip to a substrate. A supply spool and a take-up spool for the backing strip are rotatably mounted in a housing. An applicator tip is arranged on the housing and includes an application edge around which the backing strip runs. Furthermore, a brake mechanism, active during the functional operation of the hand device is provided. The brake mechanism has a locking device which interacts with one of the spools. To guarantee a compact design and economical fabrication, the locking device is arranged to be integral with the applicator tip.

The present invention relates to an improved return lock device for a hand device for the transfer of a film from a backing strip to a substrate. More particularly, the present invention relates to a return lock that is integral with the applicator tip of the hand device.
A hand device for transferring a film from a backing strip to a substrate (alternately referenced herein as a xe2x80x9chand devicexe2x80x9d for the sake of convenience without intent to limit), is described in DE 42 20 712 C2. In this hand device, a supply spool and a take-up spool are rotatably mounted in a housing. A backing strip is wound on the supply spool, extends from the supply spool to an applicator tip arranged on the circumference of the housing, is wound around an application edge of the applicator tip projecting outwardly from the housing, and extends as far as the take-up spool. To transfer a film from the backing strip to a substrate, the hand device is manually gripped, pressed with the applicator tip against the substrate, and at the same time moved along the substrate so that the film adheres to the substrate as the backing strip is pulled away from the supply spool, runs around the application edge of the applicator tip, and is wound on to the take-up spool. A drive connection is provided or is operative between the supply spool and the take-up spool. On application of the torque transmitted by pulling off the backing strip on to the storage spool, the drive connection drives the take-up spool so that it takes up the backing strip at a speed which is greater than the speed of removal. A sliding clutch is provided between the supply spool and the take-up spool to guarantee that the speeds of supply and take-up are the same, and that a certain tension in the backing strip running on the take-up spool is not exceeded. Thus, tearing of the backing strip is prevented because of the sliding clutch. Here, the supply spool and the take-up spool can be arranged on a common axis of rotation, i.e., adjacent to each other. Alternatively, the supply spool and the take-up spool can be arranged axially parallel in the same circumferential plane of the backing strip, the take-up spool being arranged between the supply spool and the applicator tip.
In the hand device described in DE 42 20 712 C2, the drive connection between the supply spool and the take-up spool with integrated sliding clutch is formed by at least one pair of friction surfaces directly engaging each other, which surfaces are formed on opposing inner and outer sides of the disc-shaped spool walls. In order to guarantee rotary entrainment between the spools due to the friction acting on the frictional surfaces, a compressive stress is required for pressing the frictional surfaces against each other and prestressing them. In the hand device described in this publication, the compressive stress is generated in that at least one of the two frictional surfaces, preferably both surfaces, are formed on spool sections arranged flexibly transverse to the frictional surface concerned. The surfaces are prestressed against each other by a resilience, preferably by the spool walls themselves. The effectiveness of the rotary entrainment can be increased by engaging knobs or teeth with which the spool sections engage in each other. In this case, it is also possible that the spool sections may not be prestressed against each other, but that the rotary entrainment depends on at least one of the spool sections deviating laterally, elastically, and flexibly on mutual contact of the knobs or teeth, thereby generating a moment of resistance providing the basis of the rotary entrainment between the knobs or teeth.
A further problem with the mode of operation of existing hand devices is that both the supply spool and the take-up spool tend to run backwards somewhat after a rotary movement caused by removing the backing strip, such as a result of stresses on the backing strip. The reels reversing in this way can cause small loops which can impair the function of the hand device.
A hand device for transferring a film from a backing strip to a substrate may be provided with a return lock interacting with the take-up spool to prevent the backing strip from being pulled off the take-up spool and forming loops if the hand device is used incorrectly. In such design, the return lock is formed by a ratchet drive consisting of a toothed rim arranged on the circumferential edge of one of the winding spool walls. The rim interacts with a ratchet arm which extends sectionally to the tooth rim, and is resiliently loaded against the tooth rim so that if the direction of rotation coincides with the direction of the take-up spool, the ratchet arm runs over the tooth rim and blocks a return rotation of the take-up spool, and hence prevents looping of the backing strip in the opposite direction of rotation due to engagement in the tooth rim. The ratchet arm is connected by a plug pin connection to the lateral housing wall or the cover of the housing.
The hand device described in EP 0 606 477 A1 (corresponding to U.S. Pat. No. 5,430,904) exhibits a locking mechanism for locking the rotation of the supply spool when the hand unit is not in use. As in DE 42 20 712 C2, a backing strip extends from a supply spool, loops around an applicator tip, and extends as far as a take-up spool. The applicator tip is displaceably mounted between a retracted position of non-use and a released position of use. A ratchet arm extends from the inner end of the applicator tip to the periphery of the supply spool arranged behind the take-up spool, bypassing the take-up spool. Moreover, a stationary articulated section on the existing housing is arranged in such a position that when the applicator tip is displaced to its position of use the ratchet arm is laterally deflected to such an extent that it cannot interact with a tooth rim on the supply spool. When the applicator tip is moved to its position of non-use, the ratchet arm moves into its locking position interacting with the tooth rim on the supply spool. This known locking mechanism is capable of preventing looping of the backing strip in the non-operative position of the hand device. However, looping which occurs in the position of use, due to the intrinsic elasticity of the backing strip, for example, or due to movement of the hand device in the incorrect direction of movement, cannot be avoided with this hand device.
The present invention provides a simplified design of a hand device for transferring a film from a backing strip to a substrate with a return lock. Moreover, a hand device that is easy to install, is inexpensive to manufacture, and/or has as few components as possible, is to be provided. The locking device of the return lock or brake is formed by a component which extends integrally from the applicator tip, in the direction of an associated spool, and interacts with the applicator tip to execute a return lock. This design avoids the need for additional parts and allows simple manufacture, storage, and installation, thereby reducing production costs. The return lock or brake is able to interact with the supply spool or the take-up spool. This is possible because of the self-locking action of the drive connection between the spools.

Hand device for transferring a film from a backing strip to a substrate, with a return lock


Thermoplastic molding materials contain

The present invention relates to thermoplastic molding materials containing
A) from 5 to 97.9% by weight of a polyphenylene ether
B) from 1 to 93.9% by weight of a vinylaromatic polymer
C) from 1 to 50% by weight of an elastomeric polymer
D) from 0.1 to 10% by weight of a stabilizer mixture comprising
d1) at least one sterically hindered phenol,
d2) at least one phosphonite and
d3) at least one alkyl aryl phosphite,
E) from 0 to 70% by weight of a polyamide and
F) from 0 to 60% by weight of further additives and processing assistants,
the sum of the percentages by weight of components A) to F) being 100%.
The present invention furthermore relates to the use of the novel molding materials for the production of fibers, films and moldings and to the fibers, films and moldings obtainable thereby.
Polymer blends comprising polyphenylene ethers (PPE) and vinylaromatic polymers have long been known, cf. for example U.S. Pat. No. 3,383,435, U.S. Pat. No. 4,128,602 and U.S. Pat. No. 4,128,603.
Such blends are widely used for outdoor applications, for example as housing material for the electrical and electronic sector. Effective stabilization to heat and light is required for this purpose. Since the miniaturization of electronic components and circuits is increasing, the requirements for the corresponding housing materials are constantly growing because even very small components should have sufficiently high stability to thermal oxidation.
A number of publications relating to the heat stabilization of polymer blends comprising polyphenylene ethers and polystyrene are known. In U.S. Pat. No. 4,255,321, for example, mixtures of a metal sulfide, a metal oxide and a phosphite are used for the heat stabilization of PPE/HIPS blends.
DE-A 26 54 841 relates to thermoplastic molding materials based on polyphenylene ethers and high impact polystyrene, whose thermal stability is improved by adding a secondary aromatic amine or by combinations of the amine with sulfides and/or phosphites.
Furthermore, use of phosphites which contain substituted phenyl groups was disclosed in JP-A 55/025 347 for stabilizing polyphenylene ethers.
The use of sterically hindered amines in combination with phosphites, benzotriazoles or sterically hindered phenols for UV and heat stabilization of PPE/HIPS blends forms the subject of WO 81/02021.
The literature furthermore discloses that mixtures of sterically hindered phenols and phosphinites effectively protect molding materials comprising polyphenylene ethers and high impact polystyrene from heat aging (eg. EP 36 278 and EP-A 38 183).
U.S. Pat. No. 4,483,953 relates to thermoplastic molding materials comprising PPE and HIPS, which are heat-stabilized by a stabilizer system comprising ZnS, ZnO and a special diphosphite. However, the effect of the diphosphite is demonstrated only on the basis of the discoloration occurring during processing. The improvement in the color stability of thermoplastic molding materials comprising polyphenylene ether and HIPS forms the subject of EP-A 243 761. Here, mixtures of triaryl phosphates and alkyl aryl phosphites result in a better color quality after storage under UV light.
It is an object of the present invention to provide thermoplastic molding materials which have very good thermal stability to oxidation, flowability and good toughness.
These combined properties should also be possessed by mini-components. It is a further object of the present invention to provide a stabilizer combination which ensures good toughness, in particular good low-temperature toughness in the PPE blends, which should be as far as possible independent of the impact modifier used.
We have found that this object is achieved by the molding materials defined at the outset.
Preferred materials of this type and their use are described in the subclaims.
Component A
According to the invention, the polyphenylene ethers A are contained in the compositions in an amount of from 5 to 97.9, preferably from 15 to 88, in particular from 20 to 83, % by weight, based on the total composition.
The polyphenylene ethers A are known per se. They are compounds based on substituted, in particular disubstituted, polyphenylene ethers, the ether oxygen of one unit being bonded to the benzene nucleus of the neighboring unit. Polyethylene ethers substituted in the 2- and/or 6-position relative to the oxygen atom are preferably used. Examples of substituents are halogen, such as chlorine or bromine, and alkyl of 1 to 4 carbon atoms which preferably has no a tertiary hydrogen atom, eg. methyl, ethyl, propyl or butyl. The alkyl radicals may in turn be substituted by halogen, such as chlorine or bromine, or by hydroxyl. Further examples of possible substituents are alkoxy, preferably of up to 4 carbon atoms, or phenyl which is unsubstituted or substituted by halogen and/or by alkyl. Copolymers of different phenols, for example copolymers of 2,6-dimethylphenol and 2,3,6-trimethylphenol, are also suitable. Mixtures of different polyphenylene ethers may of course also be used.
Examples of polyphenylene ethers B are poly(2,6-dilauryl-1,4-phenylene ether), poly(2,6-diphenyl-1,4-phenylene ether), poly(2,6-dimethoxy-1,4-phenylene ether), poly(2,6-diethoxy-1,4-phenylene ether), poly(2-methoxy-6-ethoxy-1,4-phenylene ether), poly(2-ethyl-6-stearyloxy-1,4-phenylene ether), poly(2,6-dichloro-1,4-phenylene ether), poly(2-methyl-6-phenyl-1,4-phenylene ether), poly(2,6-dibenzyl-1,4-phenylene ether), poly(2-ethoxy-1,4-phenylene ether), poly(2-chloro-1,4-phenylene ether), poly(2,5-dibromo-1,4-phenylene ether).
Preferably used polyphenylene ethers are those in which the substituents are alkyl of 1 to 4 carbon atoms, such as poly(2,6-dimethyl-1,4-phenylene ether), poly(2,6-diethyl-1,4-phenylene ether), poly(2-methyl-6-ethyl-1,4-phenylene ether), poly(2-methyl-6-propyl-1,4-phenylene ether), poly(2,6-dipropyl-1,4-phenylene ether) and poly(2-ethyl-6-propyl-1,4-phenylene ether).
For the purposes of the present invention, polyphenylene ethers are also to be understood as meaning those which are modified with monomers such as fumaric acid, maleic acid or maleic anhydride.
Such polyphenylene ethers are described, inter alia, in WO 87/00540 and are suitable in particular for blends of PPE with a polyamide.
With regard to the physical properties of the polyphenylene ether, those which have a weight average molecular weight MW of from 8000 to 70,000, preferably from 12,000 to 50,000, in particular from 20,000 to 49,000, are used in the compositions.
This corresponds to a limiting viscosity of from 0.18 to 0.7, preferably from 0.25 to 0.55, in particular from 0.30 to 0.54 dl/g, measured in chloroform at 25xc2x0 C.
The molecular weight distribution is determined in general by means of gel permeation chromatography (Shodex separation columns 0.8xc3x9750 cm of the type A 803, A 804 and A 805 with tetrahydrofuran as eluent at room temperature). The polyphenylene ether samples are dissolved in tetrahydrofuran under superatmospheric pressure at 110xc2x0 C., 0.16 ml of a 0.25% strength by weight solution being injected.
Detection is effected in general by means of a UV detector. Calibration of the columns was carried out using polyphenylene ether samples whose absolute molecular weight distributions were determined by a GPC/laser light scattering combination.
Component B
According to the invention, component B is contained in the compositions in amounts of from 1 to 93.9, preferably from 10 to 83, in particular from 15 to 78, % by weight, based on the total weight of the composition.
Components B are vinylaromatic polymers which are preferably compatible with the polyphenylene ether used.
Both homopolymers and copolymers of vinylaromatic monomers of 8 to 12 carbon atoms are suitable and are prepared in the presence of a rubber. The rubber content is from 5 to 25, preferably from 8 to 17, % by weight.
Toughened polystyrenes or copolymers of styrene and other vinylaromatic compounds are particularly suitable. Such toughened polystyrenes are generally known as HIPS, are for the most part commercially available and have a viscosity number (VN) of the hard matrix of from 50 to 130, preferably from 60 to 90, ml/g (0.5% strength in toluene at 23xc2x0 C.).
Suitable monovinylaromatic compounds are styrenes alkylated on the nucleus or side chain. Examples are chlorostyrene, xcex1-methylstyrene, p-methylstyrene, vinyltoluene and p-tert-butylstyrene. However, styrene alone is preferably used.
The homopolymers are generally prepared by the known mass, solution or suspension methods (cf. Ullmans Enzyklopxc3xa4die der techn. Chemie, Volume 19, pages 265 to 272, Verlag Chemie, Weinheim 1980). The homopolymers may have a weight average molecular weight MW of from 3000 to 300,000, which can be determined by conventional methods.
Examples of suitable comonomers for the preparation of copolymers are (meth)acrylic acid, alkyl (meth)acrylates where the alkyl radical is of 1 to 4 carbon atoms, acrylonitrile and maleic anhydride as well as maleimides, acrylamide and methacrylamides and their N,N- or N-alkyl-substituted derivatives where the alkyl radical is of 1 to 10 carbon atoms.
Depending on their chemical structure, the comonomers are contained in the styrene polymers in different amounts. The miscibility of the copolymer with the polyphenylene ether is critical with regard to the content of comonomers in the copolymer. Such miscibility limits are known and are described, for example, in U.S. Pat. Nos. 4,360,618 and 4,405,753 and in the publication by J. R. Fried and G. A. Hanna, Polymer Eng. Sci., 22 (1982), 705 et seq. The copolymers are prepared by known methods, which are described, for example, in Ullmanns Enzyklopxc3xa4die der techn. Chemie, Volume 19, page 273 et seq., Verlag Chemie, Weinheim (1980). In general, the copolymers have a weight average molecular weight (Mw) of 10,000 to 300,000, which can be determined by conventional methods.
Component B is preferably high impact polystyrene.
The generally used processes for the preparation of high impact styrene polymers are the mass or solution polymerization in the presence of a rubber as described, for example, in U.S. Pat. No. 2,694,692, and processes for mass suspension polymerization, as described, for example, in U.S. Pat. No. 2,862,906. Other processes can of course also be used, provided that the desired particle size of the rubber phase is obtained.
Component C
Elastomeric polymers C (often also referred to as elastomers or impact modifiers) are, according to the invention, contained in the compositions in an amount of from 1 to 50% by weight, based on the total composition. Preferred compositions contain from 1 to 25, in particular from 1 to 20, % by weight of component C, which differs from component B).
Natural or synthetic rubbers can of course be used as component C. In addition to natural rubber, other impact modifiers are, for example, polybutadiene, polyisoprene or copolymers of butadiene and/or isoprene with styrene and other comonomers, which have a glass transition temperature of from about xe2x88x92100xc2x0 C. to +25xc2x0 C., preferably less than 0xc2x0 C., determined according to K. H. Illers and H. Breuer, Kolloidzeitschrift 190 (1) (1963) 16-34. Appropriately hydrogenated products may also be used.
Preferred impact modifiers are block polymers of vinylaromatics and dienes. Impact modifiers of this type are known. German Published Applications DE-AS 1,932,234, and DE-AS 2,000,118 and German Laid-Open Application DE-OS 2,255,930 describe elastomeric block copolymers having different compositions and comprising vinylaromatic and diene blocks. The use of appropriate hydrogenated block copolymers, if required as a mixture with the unhydrogenated intermediate, as impact modifiers is described, for example, in German Laid-Open Applications DE-OS 2,750,515, DE-OS 2,434,848 and DE-OS 3,038,551, EP-A-0 080 666 and WO 83/01254. The disclosure of the above publications is hereby incorporated by reference.
Preferred impact modifiers C are block copolymers of vinylaromatics and dienes, which are distinguished by the fact that a soft block comprising diene and vinylaromatic is present instead of a pure diene rubber, diene and vinylaromatic being randomly distributed in the soft block.
Preferred vinylaromatics are styrene, xcex1-methylstyrene, vinyltoluene and mixtures of these compounds. Preferred dienes are butadiene, isoprene, piperylene, 1-phenylbutadiene and mixtures of these compounds. A particularly preferred monomer combination comprises butadiene and styrene.
Particularly preferably, the soft blocks are composed of from 31 to 75% by weight of styrene and from 25 to 69% by weight of butadiene. Very particularly preferably soft blocks are those which have a butadiene content of from 34 to 69% by weight and a styrene content of from 31 to 66% by weight.
Block copolymers of styrene and butadiene having a monomer composition of from 15 to 66, in particular from 25 to 62, % by weight of diene and from 34 to 85, in particular from 38 to 75, % by weight of vinylaromatic are particularly preferred.
The solid block copolymer contains in general from 60 to 95, preferably from 70 to 90, in partiuclar from 80 to 88, % by volume of the soft blocks. The amounts of the hard phase formed from the vinylaromatic are accordingly from 5 to 40, preferably from 10 to 30, in particular from 12 to 20, % by volume.
The block copolymers are unambiguously defined by the quotient of the proportion by volume of the soft blocks and the % by weight of diene in the soft blocks. In addition, block copolymers are as a rule characterized by glass transition temperatures of from xe2x88x9250 to +25xc2x0 C., in particular from xe2x88x9250 to +5xc2x0 C.
The composition of the block copolymers may, as a statistical average, be homogeneous or inhomogeneous along the chain. The chain structure of the block copolymers may be linear or star-like. The structure may be described, for example, by the following general formulae:
Here, V is a hard phase comprising vinylaromatics, Q/Vm+1 is a soft block, X is a bifunctional or polyfunctional initiator and Y is a coupling center which was formed with a bifunctional or polyfunctional coupling agent. m and n are integers beginning with one.
Preferred block copolymers have the structure V-Q/V-V, X-[Q/V-V]2 or Y-[Q/V-V]2, where the soft block Q/V in turn may be divided into sub-blocks. The soft block preferably consists of from 2 to 15, in particular from 3 to 10, random sub-blocks.
The block copolymers can be prepared by living anionic polymerization in nonpolar solvents with the addition of polar cosolvents acting as Lewis bases. Aliphatic hydrocarbons, such as cyclohexane or methylcyclohexane, are preferably used as solvents. Suitable cosolvents are ethers, such as tetrahydrofuran, or aliphatic polyethers, eg. diethylene glycol dimethyl ether, or tertiary amines, such as tributylamine or pyridine.
Examples of initiators for the anionic polymerization are organometallic compounds, including methyllithium or ethyl lithium, n-propyl lithium, n-butyl lithium, sec-butyl lithium and tert-butyllithium.
The coupling center Y is formed by the reaction of the reactive anionic chain ends with a bifunctional or polyfunctional coupling agent. Such coupling agents are known per se. Divinylbenzene or epoxidized glycides, such as epoxidized linseed oil or soybean oil, are preferred.
The anionic polymerization is carried out in a plurality of stages. A part of the monomers is initially taken in the reactor and the anionic polymerization is initiated by adding the initiator. In order to achieve a defined chain structure which can be calculated from the monomer and the initiator dose, it is advisable to allow the reaction to take place to high conversions (xe2x89xa799%) before the second monomer addition is effected. However, this is not absolutely essential. The order of the addition of the monomers depends on the chosen block structure. In the case of monofunctional initiation, first vinylaromatic is either initially taken or directly metered in. Subsequently, diene and vinylaromatic should be added as far as possible simultaneously. The random structure and composition of the soft block Q/V are determined by the dose of diene relative to vinylaromatic compound, the concentration and chemical structure of the Lewis base and the reaction temperature. Thereafter, either the second hard phase V is polymerized on by adding the vinylaromatic or coupling is effected with a coupling agent. In the case of bifunctional initiation, the soft block Q/V is synthesized further, followed by the hard phase V.
The block copolymers can be worked up by protonating the carbanions with an alcohol, such as isopropanol, acidifying the reaction mixture, for example with a mixture of CO2 and water, and removing the solvent. The block copolymers may contain antioxidants and antiblocking agents.
Such block copolymers having a random structure of the blocks of the soft phase are disclosed in DE-A 44 20 952.0 and are preferably used in the novel molding materials.
Nonhydrogenated and/or hydrogenated A-B-A block rubbers are also preferably contained in the novel molding materials, A being a vinylaromatic block and B a diene block.
The nonhydrogenated ABA block rubbers which lead to molding materials having very good low-temperature toughness are particularly preferred.
Component D
The novel molding materials contain as component D, from 0.1 to 10, preferably from 0.1 to 5, in particular from 0.1 to 3, % by weight of a stabilizer combination comprising
d1) at least one sterically hindered phenol
d2) at least one phosphonite
d3) at least one alkyl aryl phosphite.
The mixing ratios of components d1 to d3 may be chosen freely within the abovementioned total amounts.
Suitable sterically hindered phenols d1) are in principle all compounds which have a phenolic structure and at least one bulky group, preferably at least 2 sterically hindered OH groups, per molecule.
Preferred compounds are, for example, those of the formula
where:
R1 and R2 are each alkyl, substituted alkyl or a substituted triazole group, it being possible for R1 and R2 to be identical or different, and
R3 is an alkyl, substituted alkyl, alkoxy or substituted amino.
Antioxidants of the stated type are described, for example, in DE-A-27 02 661 (U.S. Pat. No. 4,360,617).
A further group of preferred sterically hindered phenols is derived from substituted benzenecarboxylic acids, in particular substituted benzenepropionic acid.
Particularly preferred compounds from this class are compounds of the formula
where R4, R5, R7 and R8, independently of one another, are each C1-C8-alkyl which in turn may be substituted (at least one of them is a bulky group) and R6 is a divalent aliphatic radical of 1 to 10 carbon atoms which may also have Cxe2x80x94O-bonds in the main chain.
Preferred compounds of this formula are
(Irganox(copyright) 245 from Ciba-Geigy)
(Irganox(copyright) 259 from Ciba-Geigy)
(Irganox(copyright) 1010 from Ciba-Geigy)
In general, examples of sterically hindered phenols are:
2,2xe2x80x2-methylenebis(4-methyl-6-tert-butylphenol), 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate], pentaerythrityl tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], distearyl 3,5-di-tert-butyl-4-hydroxybenzyl phosphonate, 2,6,7-trioxa-1-phosphabicyclo-[2.2.2]oct-4-ylmethyl 3,5-di-tert-butyl-4-hydroxyhydro-cinnamate, 3,5-di-tert-butyl-4-hydroxyphenyl-3,5-distearyl-thiotriazylamine, 2-(2xe2x80x2-hydroxy-3xe2x80x2,5xe2x80x2-di-tert-butylphenyl)-5-chlorobenzotriazole, 2,6-di-tert-butyl-4-hydroxymethylphenol, 1,3,5-trimethyl-3,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 4,4xe2x80x2-methylenebis(2,6-di-tert-butylphenol), 3,5-di-tert-butyl-4-hydroxybenzyldimethylamine and N,Nxe2x80x2-hexamethylenebis-3,5-di-tert-butyl-4-hydroxyhydro-cinnamide.
Diethyl 3,5-bis(t-Butyl)-4-hydroxybenzyl-phosphonate and octadecyl 3-(3,5-bis(t-butyl)-4-hydroxyphenyl)propionate, which are commercially available under the tradenames Irganox(copyright) 1222 and Irganox(copyright) 1076 from Ciba Geigy, are particularly preferably used.
The antioxidants (d1), which may be used individually or as mixtures, are employed in an amount of from 0.05 to 3, preferably from 0.1 to 1.0, in particular from 0.2 to 0.6, % by weight, based on the components A) to F).
Suitable phosphonites d2) are those of the general formula I
where R1 is C4-C20-alkyl, C5-C8-cycloalkyl, unsubstituted or substituted C6-C20-aryl or an Oxe2x80x94, Sxe2x80x94 or N-containing 5- or 6-membered heterocyclic radical or a group of the formula II
where
R4 are identical or different alkyl groups of 1 to 18, preferably 1 to 4, carbon atoms, and
R2 and R3, independently of one another, are each hydrogen, C4-C20-alkyl, C5-C8-cycloalkyl, unsubstituted or substituted C6-C20-aryl, an Oxe2x80x94, Sxe2x80x94 or N-containing 5- or 6-membered heterocyclic radical or an alkali metal or alkaline earth metal.
Preferred are C6-C20-aryl radicals which may be substituted by OH and/or by C1-C9-alkyl.
Compounds of the formula (I) in which R1, R2 and R3 are each C4-C12-alkyl, C5- or C6-cycloalkyl and/or C6-cycloalkyl and/or C6-C20-aryl are also preferred.
The stabilizing compounds of the general formula (I) which are to be used according to the invention are commercially available under the tradenames Irgafos P-EPQ from Ciba Geigy and can be prepared by the processes known to a person skilled in the art, as described, for example, in Houben-Weyl, Vol. 12/1, Thieme-Verlag, Stuttgart 1963, page 324 et seq. Thus, the compounds of the general formula (I) can be prepared, for example, by reacting dihalophosphines with hydroxy compounds, such as alcohols or phenols, in the presence of acid acceptors, such as tertiary amines, or by Grignard reaction or by reacting alkali metal or alkaline earth methal organyls with phosphorous triesters or phosphorous diester halides. Typical compounds of this type are known as stabilizers for polypropylene [cf. J. Appl. Polym. Sci. 27 (1982), 951 et seq.] and other polymers [cf. EP-B-5447].
Examples of the phosphonites to be used according to the invention are monophosphonites were R1, R2 and R3 are each C1-C20-alkyl, such as nonyl, dodecyl or octadecyl, or aryl, such as phenyl, nonylphenyl, 2,4-dimethylphenyl, 2,4-di-tert-butylphenyl, 3,5-dimethyl-4-hydroxyphenyl, 3,5-di-tert-butyl-4-hydroxyphenyl, or cycloalkyl, such as cyclohexyl or 3,3,5,5-tetramethylcyclohexyl, or heterocyclic groups which are derived, for example, from imidazole. However, diphosphonites in which R1 is a C2-C20-alkylene, cycloalkylene or arylene group, eg. hexylene, nonylene or cyclohexylene, phenylene or 4,4xe2x80x2-bisphenylylene, or a group of the formula II in which R4 are identical alkyl groups, preferably tert-butyl are particularly preferred.
The following phosphonites are particularly preferably used:
bis(2,4-di-tert-butylphenyl) phenyl phosphonite, tris(2,4-di-tert-butylphenyl) phosphonite, tetrakis(2,4-di-tert-butyl-6-methylphenyl) 4,4xe2x80x2-biphenylylene diphosphonite, tetrakis(2,4-di-tert-butylphenyl) 4,4xe2x80x2-biphenylylene diphosphonite, tetrakis(2,4-dimethylphenyl) 1,4-phenylene diphosphonite, tetrakis(2,4-di-tert-butylphenyl) 1,6-hexylene diphosphonite and/or tetrakis(3,5-dimethyl-4-hydroxyphenyl) 4,4xe2x80x2-biphenylylene diphosphonite and tetrakis(3,5-di-tert-butyl-4-hydroxyphenyl) 4,4xe2x80x2-biphenylylene diphosphonite.
Very particularly suitable are the diphosphonites tetrakis-(2,4-di-tert-butylphenyl) 4,4xe2x80x2-biphenylylene diphosphonite, tetrakis(2,4-di-tert-butylphenyl) 1,6-hexylene diphosphonite, tetrakis(3,5-dimethyl-4-hydroxyphenyl) 4,4xe2x80x2-biphenylylene diphosphonite and tetrakis-(3,5-di-tert-butyl-4-hydroxyphenyl) 4,4xe2x80x2-biphenylylene diphosphonite and tetrakis(2,4-di-tert-butyl) 1,4-phenylene diphosphonite, where in turn the diphosphonites tetrakis(3,5-dimethyl-4-hydroxyphenyl) 4,4xe2x80x2-biphenylylene diphosphonite and tetrakis(3,5-di-tert-butyl-4-hydroxylphenyl) 4,4xe2x80x2-biphenylylene diphosphonite are particularly preferred.
Particularly preferred radicals R2 and R3 are identical or different 2,4-dialkylphenyl groups, 2,4-Di-tert-butylphenyl being very particularly preferred. An example of a preferred compound is tetrakis(2,4-di-(tert-butyl)phenyl) 4,4xe2x80x2-biphenylylene diphosphonite.
Examples of alkali metals and alkaline earth metals R2 and R3 are sodium, potassium and lithium. Such metal or metalloid salts of phosphonic acid are disclosed, inter alia, in EP-A-324 716, GB-A 22 11 850, EP A 245 207 and EP-A 321 002.
The phosphonites d2), which may be used individually or as mixtures, are employed in an amount of from 0.05 to 3, preferably from 0.1 to 2.0, in particular from 0.2 to 1, % by weight, based on the components A) to F).
The novel molding materials contain, as component d3), an alkyl aryl phosphite of the general formula III
where
R5, R6 and R7 independently of one another, are an aromatic radical of 6 to 18, preferably 6 to 14, carbon atoms or branched or linear alkyl of 1 to 20, preferably 14 to 18 carbon atoms, with the proviso that at least one radical R5, R6 or R7 is alkyl.
Preferred diaryl monoalkyl phosphites d3) are bis(p-tert-Butylphenyl) octadecyl phosphite, diphenyl isodecyl phosphite, diphenyl decyl phosphite and 2-ethylhexyl diphenyl phosphite.
Particularly suitable monoaryl dialkyl phosphites are diisodecyl p-tolyl phosphite and diisodecyl phenyl phosphite, diisodecyl phenyl phosphite being very particularly preferred.
The component d3) is contained in the novel molding materials in amounts of from 0.01 to 4, preferably from 0.1 to 3, in particular from 0.2 to 2.5, very particularly from 0.2 to 2, % by weight, based on the components A)-F).
The polyamides which may be present as component E) in the materials are known per se and comprise the semicrystalline and amorphous resins having weight average molecular weights of at least 5000, which are usually referred to as nylon. Such polyamides are described, for example, in U.S. Pat. Nos. 2,071,250, 2,071,251, 2,130,523, 2,130,948, 2,241,322, 2,312,966, 2,512,606 and 3,393,210.
The polyamides can be prepared, for example, by condensation of equimolar amounts of a saturated or of an aromatic dicarboxylic acid of 4 to 12 carbon atoms with a saturated or aromatic diamine of up to 14 carbon atoms or by condensation of xcfx89-aminocarboxylic acids or polyaddition of lactams.
Examples of polyamides are polyhexamethyleneadipamide (nylon 66), polyhexamethyleneazelaamide (nylon 69), polyhexamethylenesebacamide (nylon 610), polyhexamethylenedodecanediamide (nylon 612), the polyamides obtained by ring cleavage of lactams, such as polycaprolactam or polylaurolactam, and the amide of poly-11-aminoundecanoic acid and a polyamide obtained from di(p-aminocyclohexyl)methane and dodecanedioic acid.
According to the invention, it is also possible to use polyamides which have been prepared by copolycondensation of two or more of the abovementioned monomers or their components, for example copolymers of adipic acid, isophthalic acid or terephthalic acid and hexamethylenediamine or copolymers of caprolactam, terephthalic acid and hexamethylenediamine. Preferred partly aromatic copolyamides of this type contain, as components e1), units which are derived from terephthalic acid and hexamethylenediamine. A small amount of terephthalic acid, preferably not more than 30% by weight of the total aromatic dicarboxylic acid used, can be replaced by isophthalic acid or other aromatic dicarboxylic acids, preferably those in which the carboxyl groups are in the para position.
Partially aromatic copolyamides which, in addition to units e1) which are derived from terephthalic acid and hexamethylenediamine, contain units which are derived from xcex5-caprolactam (e2), and/or units which are derived from adipic acid and hexamethylenediamine (e3) are particularly preferred.
In such polyamides, the amount of units which are derived from xcex5-caprolactam is usually up to 50, preferably from 20 to 50, in particular from 25 to 40, % by weight, while the amount of units which are derived from adipic acid and hexamethylenediamine is usually up to 60, preferably from 30 to 60, in particular from 35 to 55% by weight.
Such copolyamides may also contain both units of xcex5-caprolactam and units of adipic acid and hexamethylenediamine. In this case, it is advantageous if the amount of units which are free of aromatic groups is at least 10, preferably at least 20, % by weight. The ratio of the units which are derived from xcex5-caprolactam to those which are derived from adipic acid and hexamethylenediamine is not subject to any particular restriction.
Polyamides having from 50 to 80, in particular from 60 to 75, % by weight of units which are derived from terephthalic acid and hexamethylenediamine (units e1)) and from 20 to 50, preferably from 25 to 40% by weight of units which are derived from xcex5-caprolactam (units e2)), have proven particularly advantageous for many intended uses.
Such partly aromatic copolyamides can be prepared, for example, by the process described in EP-A-129 195 and EP 129 196.
Linear polyamides having a melting point above 200xc2x0 C. are preferred.
The melting points of the partly aromatic copolyamides are from 270 to 325xc2x0 C., preferably from 280 to 310xc2x0 C., this high melting point also being associated with a high glass transition temperature of, as a rule, more than 75xc2x0 C., in particular more than 85xc2x0 C. (in the dry state).
Preferred polyamides are polyhexamethyleneadipamide, polyhexamethylenesebacamide and polycaprolactam as well as polyamide 6/6T (copolyamid of caprolactam, hexamethylenediamine/terephthalic acid) and polyamide 66/6T (copolyamide of hexamethylendiamine/adipic acid/terephthalic acid).
Polyamides which are obtainable, for example, by condensation of 1,4-diaminobutane with adipic acid at elevated temperatures (polyamide 4,6) may also be mentioned. Preparation processes for polyamides having this structure are described, for example, in EP-A 38 094, EP-A 38 582 and EP-A 39 524.
The polyamides E) generally have a relative viscosity of from 2 to 5 dl/g determined using a 1% strength by weight solution in 96% strength sulfuric acid at 23xc2x0 C., which corresponds to a molecular weight of from about 15,000 to 45,000. Polyamides having a relative viscosity of from 2.4 to 3.5, in partiuclar from 2.5 to 3.4, are preferably used.
The amount of the polyamides E) in the novel molding materials is from 0 to 70, preferably up to 65, in particular up to 60, % by weight, based on A) to F).
Component F
The novel molding materials contain, as component F, further additives or processing assistants or mixtures thereof. The amount of component F is in general from 0 to 60% by weight, based on the total composition. It is preferably not more than 50, in particular not more than 30, % by weight, based on the total composition.
The compositions may contain, as component F, flameproofing agents in amounts of from 0 to 20, preferably up to 18, in particular up to 15, % by weight, based on the total composition A) to F).
Organophosphorus compounds, such as phosphates or phosphine oxides, may be used as flameproofing agents.
Examples of phosphine oxides are triphenylphosphine oxide, tritolylphosphine oxide, trisnonylphenylphosphine oxide, tricyclohexylphosphine oxide, tris-n-butylphosphine oxide, tris-n-hexylphosphine oxide, tris-n-octylphosphine oxide, triscyanoethylphosphine oxide, benzylbiscyclohexylphosphine oxide, benzylbisphenylphosphine oxide and phenylbis-n-hexyl-phosphine oxide. Triphenylphosphine oxide, tricyclohexylphosphine oxide, tris-n-octylphosphine oxide and triscyanoethylphosphine oxide are particularly preferably used.
Particularly suitable phosphates are alkyl- and aryl-substituted phosphates. Examples are phenyl bisdodecyl phosphate, phenyl bisneopentyl phosphate, phenyl ethyl hydrogen phosphate, phenyl bis(3,5,5-trimethylhexyl) phosphate, ethyl diphenyl phosphate, bis(2-ethylhexyl) p-tolyl phosphate, tritolyl phosphate, trixylyl phosphate, trimesityl phosphate, bis(2-ethylhexyl) phenyl phosphate, tris(nonylphenyl) phosphate, bis(dodecyl) p-tolyl phosphate, tricresyl phosphate, triphenyl phosphate, dibutyl phenyl phosphate, p-tolyl bis(2,5,5-trimethylhexyl) phosphate and 2-ethylhexyl diphenyl phosphate. Phosphorus compounds in which each R is aryl are particularly suitable. Triphenyl phosphate, trixylyl phosphate and trimesityl phosphate are very particularly suitable. Cyclic phosphates may also be used. Particularly suitable here is diphenyl pentaerythrityl diphosphate.
Mixtures of different phosphorus compounds may also be used. For example, mixtures which are composed of
xcex1) at least one phosphine oxide of the general formula IV
xe2x80x83where R1, R2 and R3 are identical or different alkyl, aryl, alkylaryl or cycloalkyl groups of 8 to 40 carbon atoms, and
xcex2) at least one phosphate of the general formula II
xe2x80x83where R4, R5 and R6 are identical or different alkyl, aryl, alkylaryl or cycloalkyl groups of 8 to 40 carbon atoms,
and
xcex3) a boron compound
are preferred.
Mixtures of the following phosphine oxide xcex1) and phosphate xcex2) combinations are particularly preferred: triphenylphosphine oxide/triphenyl phosphate or trixylyl phosphate, tricyclohexylphosphine oxide and triphenyl phosphate, triscyanoethylphosphine oxide and triphenyl phosphate, tris-n-octylphospine oxide and triphenyl phosphate. Mixtures of a plurality of phosphine oxides and phosphates may also be used, for example the mixture of triphenylphosphine oxide, triphenyl phosphate and trixylyl phosphate.
Boron compounds xcex3) are understood as meaning both inorganic and organic boron compounds.
Examples of inorganic boron compounds are boric acid, B2O3 and salts of boric acid, preferably with alkali metals or alkaline earth metals. Boric acid, sodium borate and boron oxide are particularly preferred.
Organic boron compounds xcex3) are, for example, tetraphenyl borates, for example sodium tetraphenylborate and tribenzyl borate.
The composition of the mixture is in general (based on the content of the total mixture)
xcex1) from 1 to 98.9, preferably from 10 to 85, in particular from 20 to 70, % by weight,
xcex2) from 1 to 98.9, preferably from 10 to 85, in particular from 20 to 70, % by weight,
xcex3) from 0.1 to 70, preferably from 5 to 50, in particular from 10 to 30, % by weight.
In addition, organophosphorus compounds of the general formulae VI to VIII are suitable as flameproofing agents:
where R7 and R11 are each alkyl or aryl, R8, R10, R12 and R13 are each alkyl, aryl, alkoxy or aryloxy, n and p are each an integer from 1 to 30, R9 is alkyl, xe2x80x94SO2xe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94Nxe2x95x90Nxe2x80x94 or R14xe2x80x94Pxe2x95x90O and R14 is alkyl, aryl or alkylaryl.
In general, mixtures of different oligomers or isomers of these organophosphorus compounds are used.
The molecular weight is in general not more than 1000, preferably from 150 to 800.
Of course, mixtures of the stated flameproofing agents may also be used.
Examples of antidrip agents are additives such as Teflon or the polymers described in DE-A 195 24 585, which may be present in amounts of up to 1, preferably up to 0.7, % by weight.
Examples of further additives are heat stabilizers and light stabilizers, lubricants and mold release agents and colorants, such as dyes and pigments in conventional amounts. Other additives are reinforcing materials, such as glass fibers, carbon fibers or aromatic polyamide fibers, and/or fillers, gypsum fibers, synthetic calcium silicates, kaolin, calcined kaolin, wollastonite, talc and chalk.
Lubricants such as polyethylene wax are also suitable additives.
Carbon black or titanium dioxide may be used, for example, as pigments.
When TiO2 is used, the mean particle size is as a rule from 50 to 400 nm, in particular from 150 to 240 nm. Rutile and anatase are used industrially and, if required, are coated with metal oxides, eg. aluminas, silicas, oxides of zinc or siloxanes.
Carbon blacks are to be understood as meaning microcrystalline, finely divided carbon (cf. Kunststofflexikon, 7th Edition 1980).
Suitable examples are the furnace blacks, acetylene blacks, gas blacks and thermal blacks obtainable by thermal preparation.
The particle sizes are preferably from 0.01 to 0.1 xcexcm and the surface areas from 102 to 104 m2/g (BET/ASTM D 3037) with DBP absorptions of from 102 to 103 ml/100 g (ASTM D 2414).
Examples of further additives are impact modifiers which are suitable for polyamides.
The novel thermoplastic molding materials are advantageously prepared by mixing the components at from 250 to 320xc2x0 C. in a conventional mixing apparatus, such as a kneader, Banbury mixer or a single-screw extruder, preferably in a twin-screw extruder. Thorough mixing is necessary for obtaining a very homogeneous molding material. The order in which the components are mixed may be varied; two or, if required, three components may be premixed or all components may be mixed together.
The novel molding materials are distinguished by very good stability to thermal oxidation in combination with good flowability and toughness, in particular good low-temperature toughness. They are therefore suitable for the production of moldings of any type, which are preferably used in the electrical and electronics sector, for example as housing parts.

Thermoplastic molding materials stable to thermal oxidation

Abstract: Thermoplastic molding materials contain

Abstract: d2) at least one phosphonite and

Abstract: d3) at least one alkyl aryl phosphite,

Abstract: F)from 0 to 60% by weight of further additives and processing assistants,


Methods and devices for securing soft tissue to a rigid material such as bone are disclosed herein. A bone anchor is described that comprises a base and a top such that suture material may be compressed between surfaces on the base and top to secure the suture to the anchor. Also described is an inserter that can be used to insert the bone anchor into bone and move the anchor top relative to the anchor base to clamp suture material there between. Also described is a soft-tissue and bone piercing anchor and associated inserter. Methods are described that allow use of the bone anchors to provide multiple lengths of suture material to compress a large area of soft tissue against bone.

1. Field of the Invention
The present invention relates to medical devices and procedures. More particularly, the present invention relates to devices and methods for securing soft tissue to a rigid material such as bone.
2. Description of the Related Art
There are several medical procedures where a surgeon needs to attach soft tissue such as tendons or other soft connective tissue to bone. One common example is a torn rotator cuff, where the supraspinatus tendon has separated from the humerus causing pain and loss of ability to elevate and externally rotate the arm. To repair a torn rotator cuff, typically a surgical procedure is used to suture the torn tendon to the bone using a variety of methods. Some procedures utilize large incisions and involve complete detachment of the deltoid muscle from the acromion. Small diameter holes are made in the bone for passing suture material through the bone to secure the tendon. Such large incision procedures are traumatic, causing prolonged pain and recovery time. Other procedures make small incisions and use arthroscopic techniques to attach sutures using either small diameter holes or a bone anchor. However, it is difficult to manipulate sutures within the surgical site using arthroscopic techniques. In addition, when knot tying is used to secure the suture to a bone anchor, it is difficult to properly adjust the tension of the suture while tightening the knot. Similarly, when the suture is attached to a bone anchor prior to insertion of the anchor into the bone, it is difficult to judge the appropriate point of attachment so that the suture will be properly tensioned upon insertion of the bone anchor into the bone. Thus, there is a need for methods and devices that allow easy arthroscopic attachment of a suture to a bone anchor after the anchor is inserted into the bone without the use of knot tying.

System and method for attaching soft tissue to bone


A process for the production of detergent particles, comprises feeding an acid precursor of an anionic surfactant and a neutralising agent into a horizontal thin-film evaporator/drier comprising a mixing region, a drying region and a cooling region. The resultant detergent particles are graded to separate an oversize granule fraction in which at least 70 wt % of the particles have a minimum diameter of 1000 xcexcm. This fraction is fed back into the process.

The present invention relates to a process for the production of anionic detergent particles and detergent compositions containing them. More particularly the present invention relates to a process for the production of detergent particles having a high level of anionic surfactant which involves in situ neutralisation of an acid precursor of the anionic surfactant and drying of the surfactant thereby produced.
Granulation processes involving mixing and agglomeration to form detergent granules have been widely investigated as alternatives to spray drying processes. Such mechanical mixing processes offer a number of advantages over spray drying, e.g. production of higher bulk density products and increased formulation flexibility. These mechanical processes generally utilise technologies which are specific to the particular type of mixing apparatus being used. However, most of them involve forming the salt form of anionic surfactants by neutralising the acid form of the anionic surfactant with an alkaline neutralising agent (usually in solid form), inside the mixing apparatus. This is normally referred to as in situ neutralisation.
Although there are several types of mixing apparatus which may be employed, one common arrangement is a combination of a high speed mixer/densifer followed by a moderate speed mixer/densifier, e.g. as disclosed in EP-A-0 420 317.
Another common arrangement was a so-called fluid bed granulator, e.g. as described in WO-A-98/58046.
However, the present invention is concerned with a different class of apparatus, namely a horizontal thin-film evaporator/drier. Specifically, it is known that detergent particles having high anionic surfactant levels can be prepared by processes in which acid precursors of anionic surfactants are neutralised with a neutralising agent in horizontal thin-film evaporator/drier (WO-A-96/06916, WO-A-96/06917 and WO-A-97/32002; WO-A-98/38278 and WO-A-98/40461) and the mass is granulated and dried. As used herein, the term thin-film evaporator/drier is understood to include flash-driers and scraped-surface driers as described in WO-A-96/06916, WO-A-96/06917 and WO-A-97/32002.
Basically, a thin-film evaporator/drier comprises a cylindrical chamber in which is located a coaxial shaft on which is mounted a plurality of blade-like tools. The pitch of these tools can be set to different angles along the length of the cylindrical chamber, from input end to output end. The clearance between the tips of the blade-like tools and the internal surface of the cylindrical chamber is very small, typically 5 mm or less. The cylindrical chamber comprises at least a mixing region at or towards the input end of the cylindrical chamber, a cooling region at or towards the output end of the cylindrical chamber and a drying region between the mixing and cooling regions. The drying region typically comprises one or more heating zones and the cooling region may comprise one or more cooling zones (although usually only one cooling zone. Each of the heating and cooling zones is defined by a respective jacket around the cylindrical chamber with a respective axial gap between each and through which jackets, a heating or cooling liquid, as appropriate, is pumped during operation of the process. The layering agent is  typically an aluminosilicate or a silica.
WO 97/32002 discloses a  dry-neutralisation  process in which high anionic surfactant-content detergent particles are manufactured by contacting a pumpable acid precursor with a solid neutralising agent, such as for example sodium carbonate, in a thin-film evaporator/drier.
EP 555 622 (Procter and Gamble) describes the manufacture of detergent particles comprising anionic surfactant in which acid precursors are neutralised in a high shear mixer by a stoichiometric excess of particulate neutralising agent, preferably sodium carbonate. The neutralisation reaction is optimised by using neutralising agent of a narrowly defined particle size range, namely 50% by volume has a particle diameter of less than 5 microns.
EP 555 622 does not however relate to the production of high anionic surfactant-content detergent particles or to the use of thin-film evaporator/driers. According to the teaching of EP 555 622, the neutralising agent is preferably present in an amount of at least five times that required for stoichiometric neutralisation. In addition, the ratio of liquid ingredients (e.g. acid precursor) to powder ingredients (e.g. neutralising agent) introduced into the high shear mixer is most preferably from 1:2 to 1:3. It is not possible to make high anionic surfactant-content detergent particles using such excesses of neutralising agent and/or liquid to solid ratios. Indeed, the detergent particles of the examples contain merely 23 wt % anionic surfactant.
All such technologies produce a product with a distribution of different particle sizes. Those which are very small are sometimes called  fines . It is common to recycle the fines to the input stage of the mixer, in order to avoid having a dusty product. This is well known for various types of mixer. However, large particles, sometimes called  oversize , present more of a problem. Their presence in the product is undesirable, e.g. because they give rise to negative consumer perception of product quality. In other mixing processes, e.g. as described in EP-A-0 420 317 and WO-A-98/58046, it is found that oversize particles cannot be recycled without having a deleterious on the product. This means that the oversize particles have to be milled prior to recycling, which adds to production cost.
Surprisingly, it has now been found that in the case of processes utilising a horizontal thin-film evaporator/drier, oversize particles can be recycled without significantly detracting from product quality.
Accordingly, a first aspect of the present invention provides a process for the production of detergent particles, the process comprising feeding an acid precursor of an anionic surfactant and a neutralising agent into a horizontal thin-film evaporator/drier comprising a mixing region, a drying region and a cooling region, removing the detergent particles so formed from an outlet of the evaporator/drier, separating an oversize granule fraction in which at least 70 wt % of the particles have a minimum diameter of 1000 xcexcm from the detergent particles and recycling the oversize granule fraction to be fed back into the thin film evaporator/drier.
This invention also provides detergent particles obtained by the process.
The oversize granule fraction comprises at least 70 wt % of particles having a minimum diameter of 1000 xcexcm. However, preferably at least 95 wt % of particles in the oversize fraction have a minimum diameter of 700 xcexcm. Particles having a minimum specified particle diameter means those particles which would be retained on a seive having a mesh size corresponding to that size.
Preferably, at least some of the recycled granule fraction is fed back into the evaporator/drier before the cooling region, i.e. into the mixing region and/or onto the drying region and/or between those two regions.
Preferably also, the recycled oversize granule fraction constitutes an average of from 1% to 50%, more preferably from 5% to 25% by weight of the total solids dosed into the evaporator/drier.
The process is carried out in a horizontal thin-film evaporator/drier (hereinafter referred to as an  evaporator/drier). A commercial scale machine typically comprises at least 300, preferably at least 500, more preferably at least 750, especially at least 1000 blade-like tools. The clearance between the blades and the internal wall of the chamber is suitably less than 20 mm, e.g. 15 mm or less, or even 10 mm or less. The blade tip speed in operation is suitably xe2x89xa715 msxe2x88x921, preferably xe2x89xa720 msxe2x88x921. The ratio of exposed blade length to shaft radius is preferably less than 1, e.g. less than 0.5. Preferably, the large number of blades and the pitch of the blades also means that at least 40%, for example at least 45%, and even substantially the whole chamber wall (that part along the length of the shaft which carries the blades) is scraped during operation.
Initial mixing of the components occurs in the mixing region and the neutralisation reaction is begun. Mixing and neutralisation then continue throughout the process, through the drying and cooling regions.
The anionic surfactant acid precursor (hereinafter referred to as the  acid precursor ) and neutralising agent are normally fed into the mixing region of the evaporator/drier. However, all or part of either component can be dosed into the drying region. Neutralisation occurs to form a surfactant paste, which is then converted into detergent particles by the drying and mechanical action of the evaporator/drier. The evaporator/drier exerts its drying action by forming a thin layer of material on a heated surface within the drying region.
The acid precursor is suitably fed into the evaporator/drier in a liquid phase. As acid precursors can be unstable, the neutralisation preferably occurs sufficiently rapidly and substantially completely such that thermal decomposition of the acid due to elevated temperature is minimised and desirably avoided.
The neutralising agent is introduced into the evaporator/drier as a solid particulate material. Preferably, the amount of neutralising agent with respect to the acid precursor added to the mixing region is at least in stoichiometric equality, most preferably in excess. Preferably, at least 1.25 times required for stoichiometric neutralisation is used but preferably no more than 2 times. Higher amounts of neutralising agent, e.g. no more than 5 times, no more than 4.5 times, or no more than 4 times that required for stoichiometric neutralisation can be used but these higher amounts are generally less preferred.
The acid precursor and neutralising agent may be added as a single stream to the evaporator/drier, or as two or more streams.
The drying region of the evaporator/drier basically comprises a tube which is substantially circular in cross section and is thus defined by a cylindrical wall. The material entering the drying region is heated. Typically this is achieved by heating the wall of the drying region by means of a heating jacket through which water, steam or oil may be fed.
The drying region may be divided into a number of heating zones, each heated to the same or a different temperature, preferably by means of a respective heating jacket. The temperature in the drying region is preferably maintained at least 100xc2x0 C., more preferably at least 120xc2x0 C., yet more preferably at least 130xc2x0 C. Higher temperatures are possible, but it will be understood by the skilled person that it is preferable not to exceed the thermal decomposition temperature of the acid precursor or the anionic surfactant formed therefrom. Depending on the detergent active, temperatures up to 170xc2x0 C. or even up to 180xc2x0 C. are employed.
It has been found to be highly advantageous in the process of the invention to pass the material leaving the drying region of the evaporator/drier through a cooling region. The cooling region may be provided by a separate piece of apparatus, such as for example a cooling fluid bed, an airlift alternatively, may form part of the evaporator/drier apparatus.
The cooling region is preferably operated at a temperature not in excess of 50xc2x0 C. and more preferably not in excess of temperature 40xc2x0 C., e.g. 30xc2x0 C. Actively cooling the particles reduces the possibility of thermal decomposition occurring due to particles being heated to a high temperature. In addition, actively cooling reduces the risk of particles sticking/clumping which may occur when heated particles are allowed to cool passively.
Preferably, the cooling region is defined by a cylindrical wall which is cooled, for example, by a cooling jacket. Where the process is continuous, the evaporator/drier and the cooling region are suitably arranged so that the drying region and cooling region are substantially horizontally aligned to facilitate efficient drying, cooling and transport of the material through the drying region and cooling region in a generally horizontal direction.
In a preferred embodiment, the evaporator/drier apparatus includes the cooling region positioned after the drying region, and the cooling region is a tube which is substantially circular in cross section and is thus defined by a cylindrical wall. When such evaporator/drier apparatus is employed, a suitable temperature gradient is set up going from, for example, at least 100xc2x0 C. at the inlet end to, for example, not more than 80xc2x0 C. at the outlet end.
Agitation of the materials in the drying region generally provides efficient heat transfer and facilitates removal of water. Agitation reduces the contact time between the materials and the wall of the drying region, which, together with efficient heat transfer, reduces the likelihood of  hot spots  forming which may lead to thermal decomposition. Moreover, improved drying is secured thus allowing a shorter residence time and increased throughput in the heating zone(s).
Preferably, the cooling region is also provided with agitation means to effect efficient cooling of the material therein. This may be a fluidising gas in a cooling fluid bed. Alternatively, where the cooling region is part of the evaporator/drier apparatus, it is preferred to use the same rotating agitation means as defined above in relation to the drying region.
It will be understood that the cooling region may comprise more than one cooling zone.
In a preferred embodiment, drying and cooling regions together comprise three zones defined by a cylindrical wall, the first two zones being heating zones defining the drying region, and the third zone being the cooling region. Acid precursor and neutralising agent are fed in to the first zone and rotating agitation means comprising a series of radially extending paddles and/or blades mounted on a axially mounted rotatable shaft agitates and transports material through the heating and cooling zones to produce detergent particles.
Preferably, the evaporator/drier is operated at atmospheric pressure in counter-current or co-current with a gas stream at a throughput rate of 10-150 m3 per hour. The gas stream may simply be air, which may have been dried so as to reduce its moisture content, or may be a gas stream having an alkaline pH, such as for example a mixture of ammonia and air.
The process of the invention is preferably continuous as this facilitate continuous transportation of the particles.
Suitably the total average residence time in the drying region is from 30 seconds to 15 minutes, preferably from 1 minute to 12 minutes, more preferably from 2 minutes to 8 minutes. The average residence time may be determined by injecting a coloured tracer and plotting a concentration profile for the tracer exiting the drying region. The average residence time is taken as the value corresponding to 50% of the total area under the curve. Preferably, the measurement is repeated a suitable number of times.
The process of the invention may be carried out in any suitable apparatus. Suitable thin-film evaporator/drier apparatus include the  Flash Dryer/Reactor  manufactured by VRV, the  Turbodryer  manufactured by VOMM and a similar machine available from Bipex Hosokawa.
Prior to neutralisation and drying, the anionic surfactants are present and fed into the drying region of the evaporator/drier in their acid precursor form. The acid precursor can either be fed as an aqueous preparation or in anhydrous form. If added as an aqueous preparation, it is preferred that the water content does not exceed 25% by weight, more preferably not exceeding 10% by weight.
Suitable acid precursors include:
linear alkyl benzene sulphonic acids (LAS acids) which give linear alkyl benzene sulphonates (LAS) upon neutralisation. Preferably, any LAS anionic surfactant has a chain length of C8-18, more preferably C9-15 and most preferably C10-14.
alkyl and/or alkenyl sulphuric acid half-esters (i.e. the sulphation products of primary alcohols) which give alkyl and/or alkenyl sulphates upon neutralisation. The present invention has especial applicability in the production of detergent particles comprising PAS having a chain length of C10-22, preferably C12-14; Coco PAS is particularly desirable.
carboxylic acids which give soaps upon neutralisation. Preferred carboxylic acids are fatty acids with 12-18 carbon atoms, such as for example fatty acids of coconut oil, palm oil, palm kernel and tallow.
Other suitable acid precursors include alphaolefin sulphonic acids, internal olefin sulphonic acids, fatty acid ester sulphonic acids and primary sulphonic acids.
It is also possible to use combinations of various acid precursors as will be apparent to the skilled person.
The neutralising agent is a particulate base material capable of neutralising the acid precursor. In principle, any alkaline inorganic material can be used for the neutralisation but water-soluble alkaline inorganic materials are preferred.
Suitable neutralising agents include any salts of hydroxides, carbonates, bicarbonates and silicates. Suitably, the sodium, potassium, calcium or magnesium salts may be used. However, the sodium salt is preferred.
A preferred neutralising agent is sodium carbonate alone or in combination with one or more other water-soluble inorganic materials, for example, sodium bicarbonate or silicate.
Preferably, the neutralising agent has a D50 mean particle size of less than 40 xcexcm, preferably less than 30 xcexcm, more preferably less than 20 xcexcm. As used herein, the term D50 refers to the value of particle size corresponding to 50% weight percent of the particles on a size distribution curve (i.e. half of the area under the curve is to the right of this value, and half to the left).
In addition to the acid precursor and neutralising agent, other liquid and solid components may be fed to the drying region of the evaporator/drier, and/or the cooling zone if present. For example, pre-neutralised surfactants, e.g. PAS, LAS and LES may be fed into the drying region as separate streams and/or as an admixture with the neutralising agent and/or acid precursor.
However, it is desirable that the ratio of the total liquid ingredients to the total solid ingredients fed to the drying region of the evaporator/drier, or, where a cooling zone is employed, to the drying zone and cooling zone, is in the range 2:1 to 6:1, preferably from 3:1 to 5:1.
The detergent particles have an anionic surfactant content of at least 40% by weight. The present process can be used to make detergent particles with a anionic surfactant content of at least 50%, 60% or 70% by weight. The maximum amount is typically 90%, preferably 85% by weight.
It is desirable that the particles also comprise water in an amount of 0 to 8% and preferably 0 to 4% by weight of the particles.
Other non-surfactant components which may be present in the detergent particles include dispersion aids, preferably polymeric dispersion aids and more preferably urea, sugars, polyaklyleneoxides; and builders as hereinafter described.
If desired the detergent particles may comprise an organic and/or inorganic salt, e.g. a hydratable salt. Suitable materials in salts, preferably sodium, of tripolyphosphate, citrates, carbonates, sulphates, chlorides. Aluminosilicates, clays, silicas and other inorganic materials may also be included.
The particles may also contain one or more nonionic surfactants, for example as mentioned below in the context of a base powder with which the particles are admixed.
Similarly, organic materials, e.g. PEG and other polymer builder or soap may also be included in the particles, also as mentioned below in the latter context.
It is especially preferred that a salt be present in the particle when the anionic surfactant component comprises LAS.
The salt may be present at a level of up to 50% and preferably up to 30% by weight of the particles.
Desirably the detergent particles have an aspect ratio not in excess of 2 and more preferably are generally spherical in order to reduce segregation from other particles in a formulated detergent composition and to enhance the visual appearance of the powder.
The detergent particles can be coated by adding a layering agent either at the output end of the drying region of the evaporator/drier, in the cooling region, or in an additional step, e.g. on a vibrating conveyer belt. It is particularly preferred to add layering agent in the cooling region.
The layering agent may be any material capable of coating the particles in order to improve the granularity thereof. Relatively inert materials are preferred for this purpose but especially any of those inert materials which have a beneficial effect in the wash liquor, for example, aluminosilicates, silicas talcs and clays. A mixture of such materials may be used. Examples of aluminosilicates and silicas are outlined in more detail hereinbelow. The presence of any such material as a coating on the finished particles does not preclude the presence also of the material within the body of the particles.
In the case of aluminosilicates, these may be partly or solely dosed earlier in the process, i.e. not completely, or not at all, as layering agents. A particularly suitable way of implementing this is to feed an acid precursor of an anionic surfactant, a neutralising agent and aluminosilicate detergency builder into the horizontal thin-film evaporator/drier comprising a mixing region, a drying region and a cooling region, to effect neutralisation of the acid precursor, granulation, drying and cooling, to form the said detergent particles, wherein at least some of the aluminosilicate builder is fed into the thin-film evaporator/drier between the drying region and the cooling region and/or into the cooling region. Optionally, when all of the aluminosilicate builder is fed into the cooling region, the aluminosilicate is in an amount of more than 20% by weight of the particles exiting the cooling region.
Relative to the total other materials of the particles, the dosing weight ratio of the layering materials, e.g. added in the cooling zone, is preferably from 1:3 to 1:20, more preferably from 1:9 to 1:20.
The detergent particles may be post-dosed directly to a base powder obtained from any conventional detergent production process including a non tower process in which the components of the detergent composition are mixed and granulated as described e.g. in EP-A-367 339 and a spray drying process optionally followed by a post tower densification. As the detergent particles produced by the present invention may be post-dosed to such powders a significant degree of formulation flexibility is obtained and the level of active material in the fully formulated composition may be very high as desired. A further advantage is that a base powder which is substantially free of detergent active compounds may be produced as the detergent active compounds may be introduced substantially wholly as post-dosed particles.
The option of reducing the level of detergent active material in a base powder is especially advantageous where the base powder is produced by a spray drying process as a lower level of detergent active compound in the spray drying process permits a higher throughput to be secured thus increasing overall production efficiency.
Compositions according to the present invention may also contain, in addition to the detergent-active compound, a detergency builder and optionally bleaching components and other active ingredients to enhance performance and properties.
Detergent compositions of the invention may contain, in addition to the post-dosed detergent particles, one or more detergent-active compounds (surfactants) which may be chosen from soap and non-soap anionic, cationic, nonionic, amphoteric and zwitterionic detergent-active compounds, and mixtures thereof. Many suitable detergent-active compounds are available and are fully described in the literature, for example, in  Surface-Active Agents and Detergents , Volumes I and II, by Schwartz, Perry and Berch. The preferred detergent-active compounds that can be used are soaps and synthetic non-soap anionic and nonionic compounds.
Anionic surfactants are well-known to those skilled in the art. Examples include alkylbenzene sulphonates, particularly linear alkylbenzene sulphonates having an alkyl chain length of C8-C15; primary and secondary alkyl sulphates, particularly C12-C15 primary alkyl sulphates; alkyl ether sulphates; olefin sulphonates; alkyl xylene sulphonates; dialkyl sulphosuccinates; and fatty acid ester sulphonates. Sodium salts are generally preferred.
Nonionic surfactants that may be used include the primary and secondary alcohol ethoxylates, especially the C8-C20 aliphatic alcohols ethoxylated with an average of from 1 to 20 moles ethylene oxide per mole of alcohol, and more especially the C10-C15 primary and secondary aliphatic alcohols ethoxylated with an average of from 1 to 10 moles of ethylene oxide per mole of alcohol. Non-ethoxylated nonionic surfactants include alkylpolyglycosides, glycerol monoethers, and polyhydroxyamides (glucamide).
The total amount of surfactant present in the detergent composition is suitably from to 5 to 40 wt % although amounts outside this range may be employed as desired.
The detergent compositions of the invention generally also contain a detergency builder. The total amount of detergency builder in the compositions is suitably from 10 to 80 wt %, preferably from 15 to 60 wt %. The builder may be present in an adjunct with other components or, if desired, separate builder particles containing one or more builder materials may be employed.
Inorganic builders that may be present include sodium carbonate, if desired in combination with a crystallisation seed for calcium carbonate, as disclosed in GB-A-1 437 950; crystalline and amorphous aluminosilicates, for example zeolites as disclosed in GB-A-1 473 201; amorphous aluminosilicates as disclosed in GB-A-1 473 202; and mixed crystalline/amorphous aluminosilicates as disclosed in GB 1 470 250; and layered silicates as disclosed in EP-B-164 514. Inorganic phosphate builders, for example, sodium, orthophosphate, pyrophosphate and tripolyphosphate, may also be present, but on environmental grounds those are no longer preferred.
Aluminosilicates, whether used as layering agents and/or incorporated in the bulk of the particles may suitably be present in a total amount of from 10 to 60 wt % and preferably an amount of from 15 to 50 wt %. The zeolite used in most commercial particulate detergent compositions is zeolite A. Advantageously, however, maximum aluminium zeolite P (zeolite MAP) described and claimed in EP-A-384 070 may be used. Zeolite MAP is an alkali metal aluminosilicate of the P type having a silicon to aluminium ratio not exceeding 1.33, preferably not exceeding 1.15, and more preferably not exceeding 1.07.
Organic builders that may be present include polycarboxylate polymers such as polyacrylates, acrylic/maleic copolymers, and acrylic phosphinates; monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono-, di- and trisuccinates, carboxymethyloxysuccinates, carboxymethyloxymalonates, dipicolinates, hydroxyethyliminodiacetates, alkyl- and alkenylmalonates and succinates; and sulphonated fatty acid salts. A copolymer of maleic acid, acrylic acid and vinyl acetate is especially preferred as it is biodegradable and thus environmentally desirable. This list is not intended to be exhaustive.
Especially preferred organic builders are citrates, suitably used in amounts of from 5 to 30 wt %, preferably from 10 to 25 wt %; and acrylic polymers, more especially acrylic/maleic copolymers, suitably used in amounts of from 0.5 to 15 wt %, preferably from 1 to 10 wt %. The builder is preferably present in alkali metal salt, especially sodium salt, form.
Suitably the builder system comprises a crystalline layered silicate, for example, SKS-6 ex Hoechst, a zeolite, for example, zeolite A and optionally an alkali metal citrate.
Detergent compositions according to the invention may also contain a bleach system, desirably a peroxy bleach compound, for example, an inorganic persalt or organic peroxyacid, capable of yielding hydrogen peroxide in aqueous solution. The peroxy bleach compound may be used in conjunction with a bleach activator (bleach precursor) to improve bleaching action at low wash temperatures. An especially preferred bleach system comprises a peroxy bleach compound (preferably sodium percarbonate optionally together with a bleach activator), and a transition metal bleach catalyst as described and claimed in EP 458 397A and EP-A-509 787.
The compositions of the invention may contain alkali metal, preferably sodium, carbonate, in order to increase detergency and ease processing. Sodium carbonate may suitably be present in an amount from 1 to 60 wt %, preferably from 2 to 40 wt %. However, compositions containing little or no sodium carbonate are also within the scope of the invention.
Powder flow may be improved by the incorporation of a small amount of a powder structurant, for example, a fatty acid (or fatty acid soap), a sugar, an acrylate or acrylate/maleate polymer, or sodium silicate which is suitably present in an amount of from 1 to 5 wt %.
The materials that may be present in detergent compositions of the invention include sodium silicate; corrosion inhibitors including silicates; antiredeposition agents such as cellulosic polymers; fluorescers; inorganic salts such as sodium sulphate, lather control agents or lather boosters as appropriate; proteolytic and lipolytic enzymes; dyes; coloured speckles; perfumes; foam controllers; and fabric softening compounds. This list is not intended to be exhaustive.
The base composition is suitably prepared by spray-drying a slurry of compatible heat-insensitive ingredients, and then spraying on, admixing and/or postdosing those ingredients unsuitable for processing via the slurry. The detergent particles produced according to the process of the present invention are post-dosed to the base composition by conventional methods.
Detergent compositions of the invention preferably have a bulk density of at least 500 g/l, more preferably at least 550 g/liter.
Such powders may be prepared either by spray-drying, by post-tower densification of spray-dried powder, or by wholly non-tower methods such as dry mixing and granulation. A high-speed mixer/granulator may advantageously be used for such mixing. Processes using high-speed mixer/granulators are disclosed, for example, in EP-A-340 013, EP-A-367 339, EP-A-390 251 and EP-A-420 317.

Production of anionic surfactant granules by in situ neutralisation

Unilever Home and Personal Care USA division of Conopco, Inc.


A call made with a communication device is processed using multiple call processors (CPs) operatively connected to a network. CPs use processing load information from other CPs to select which CP will handle call set up when the call is requested. A similar selection process is used for selecting one of CPs to perform other call processing functions and to terminate the call upon receiving a request to terminate the call. The CP selected to set up a call, tear-down a call or perform other call processing depends on the load associated with the processor and the load associated with setting up, tearing down performing other call processing for the call.

The present invention generally relates to communications and, more particularly, to a method and apparatus for processing calls on a multiprocessor communication system.
In a communication system, call processing facilitates connectivity between two or more communication devices on a network. These communication devices include conventional phones, video-phones, or other types of devices that carry audio and/or video information. Initially, call processing uses a call setup process to allocate communication resources to be used by the communication devices when communicating over a network. For example, this may include allocating bandwidth and storage buffers on the system to be used by different communication devices to use during voice or data communication. A call tear-down process breaks the communication connection between the communication devices and reallocates the communication resources back to the system once the communication is completed.
Some communication networks use a call processor (CP) to perform the call setup and call tear-down processes. On larger networks multiple CPs handle the call setup and tear down processes. These CPs use signaling to communicate with the communication devices during the call setup and call tear-down processes.
In conventional systems CPs are statically associated with the particular communication devices throughout the call setup and tear down process. The association between a communication device and a CP remains constant even when call patterns change within the network. Unfortunately, calls often overload the network because several CPs become overloaded, even though other CPs are available to process calls. For example, increased communication activity on one part of the network may overload a single CP with call processing tasks while another CP on the network remains idle waiting for communication activity. Accordingly, it is desirable to implement methods and apparatus for processing communications on a multiprocessor network that prevent, or at least minimize the number of, processors that become overloaded.
A method consistent with this invention, for use in a network having multiple processors, of processing a call between communication devices includes selecting one of the multiple processors to setup the call when the call is requested, setting up the call using the selected processor, transferring information between the communication devices, and terminating the call upon receiving an appropriate request. Means for carrying out this method are also provided.
An apparatus consistent with this invention for processing a call between communication devices over a network includes a plurality of processors, each including memory containing instructions. The processors execute instructions and, when the call is requested, select one of the processors to set up the call, the selected one of the processors executing instructions thereby setting up the call. During the call, the processor transfers information between the communication devices. The plurality of processors also select one of the processors to terminate the call upon receiving an appropriate request.
A computer program product consistent with this invention for execution by a processor capable of processing a call between communication devices over a network including multiple processors includes program code capable of selecting a processor to set up the call when the call is requested, setting up the call using the selected processor, transferring information between the communication devices, and selecting a processor to terminate the call when call termination is requested.
A network consistent with this invention for use with communication devices for exchanging information over the network includes line cards operatively connected to the communication devices and the network to facilitate the exchange of information, and multiple call processors operatively connected to the network and the line cards, wherein each call processor is capable of determining which one of the multiple processors should be used to set up a call and which one of the multiple processors should be used to tear down the calls. In one embodiment, the determination of which processor should be used for setting up or tearing down calls is made based on relative activity levels of the processors.
The above desires, other desires, features, and advantages of the present invention will be readily appreciated by one of ordinary skill in the art from the following detailed description of the preferred implementations when taken in connection with the accompanying drawings.

Method and apparatus for processing calls on a multiprocessor communication system


Hairsetting compositions comprise as film-formers copolymers based on tert-butyl acrylate or tert-butyl methacrylate having a K value of from 10 to 50 which are obtainable by free-radical polymerization of

The present invention relates to novel hairsetting compositions which comprise as film-formers copolymers based on tert-butyl acrylate or tert-butyl methacrylate having a K value of from 10 to 50 and which are obtainable by free-radical polymerization of
A) from 30 to 72% by weight of tert-butyl acrylate or tert-butyl methacrylate or a mixture thereof as monomer A,
B) from 10 to 28% by weight of acrylic acid or methacrylic acid or a mixture thereof as monomer B, and
C) from 0 to 60% by weight of a free-radically copolymerizable monomer or of a free-radically copolymerizable monomer mixture as monomers C, where at least one of the monomers C produces a homopolymer having a glass transition temperature of less than 30xc2x0 C.,
the carboxyl groups of the copolymers being partially or completely neutralized.
EP-A 379 082 discloses hairsetting compositions which comprise as film-formers copolymers based on tert-butyl acrylate and/or tert-butyl methacrylate having a K value of from 10 to 50, which are obtainable by free-radical polymerization of
A) from 75 to 99% by weight of tert-butyl acrylate and/or tert-butyl methacrylate,
B) from 1 to 25% by weight of acrylic acid and/or methacrylic acid, and
C) from 0 to 10% by weight of a further free-radically copolymerizable monomer,
the carboxyl groups of the copolymers being, as usual, partially or completely neutralized by amines.
Parameters of these prior-art compositions which are still in need of improvement, however, are the ease of washoff of the polymer from the hair, the solubility of the film-former in aqueous formulations, which are nowadays increasingly displacing those formulations based solely on organic solvents which are ecologically acceptable, and the handle and set of the treated hair, since hair which is treated with the prior-art hairsetting compositions generally feels too brittle or too coarse.
It is an object of the present invention to prepare a hairsetting composition which no longer has the abovementioned disadvantages.
We have found that this object is achieved by the hairsetting compositions defined at the outset.
The monomer or monomers C serve to modify the properties of the copolymer. In a preferred embodiment, monomers used are C1-C18-alkyl acrylates or methacrylates, especially C1-C4-alkyl acrylates or methacrylates, or a mixture of these (meth)acrylates with N-C1-C18-alkylacrylamides or -methacrylamides, especially Nxe2x80x94C1-C4-alkylacrylamides or -methacrylamides. In these (meth)-acrylates and (meth)acrylamides, C1-C4-alkyl is suitably methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl.
Particularly good results are obtained when C comprises un-branched C2-C4-alkyl acrylates, alone or as a mixture with branched Nxe2x80x94C3-C4-alkylacrylamides. Particular preference is given to the use for this purpose of ethyl acrylate or of a mixture of ethyl acrylate and N-tert-butylacrylamide.
In a preferred embodiment, the composition of the copolymer used as film-former is
A) from 50 to 72% by weight, in particular from 60 to 70% by weight, of monomer A,
B) from 12 to 25% by weight, in particular from 15 to 23% by weight, of monomer B, and
C) from 3 to 38% by weight, in particular from 7 to 25% by weight, of monomer C.
The upper limit of 72% by weight for monomer A is particularly critical since above this limit the advantageous properties of the hairsetting composition of the invention are no longer found. The marked change in the spectrum of properties of the hairsetting composition between a content of 72 and 75% by weight of monomer A was surprising in particular in the context of the compositions from EP-A 379 082.
In a further preferred embodiment, the copolymer used as film-former is composed of
A) tert-butyl acrylate as monomer A,
B) methacrylic acid as monomer B, and
C) ethyl acrylate or a mixture of ethyl acrylate and N-tert-butylacrylamide as monomer C.
The copolymers described are prepared in a known manner by free-radical copolymerization of the monomers A, B and, if used, C. The reaction is carried out by the usual polymerization techniques, for example by the methods of suspension, emulsion or solution polymerization.
The polymerization reaction, which proceeds by a free-radical mechanism, is initiated by the customary peroxo or azo compounds, for example dibenzoyl peroxide, tert-butyl perpivalate, tert-butyl per-2-ethylhexanoate, di-tert-butyl peroxide, tert-butyl hydroperoxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, alkali metal persulfates or ammonium persulfates, azobisisobutyronitrile, hydrogen peroxide or redox initiators, advantageously in amounts of from 0.1 to 2% by weight, based on the weight of the monomers. The amounts of monomers and solvents or dispersants are advantageously chosen so as to give from 30 to 80% strength by weight solutions or dispersions, or suspensions, of the copolymers. The content of residual monomer can be reduced by postpolymerization in accordance with generally known methods.
The copolymers have K values of from 10 to 60, preferably from 15 to 40. The particular K value desired can be established in a manner known per se by appropriate choice of the polymerization conditions, such as the temperature of polymerization and the concentration of initiator. If desired, especially when employing emulsion and suspension polymerization, it may be appropriate to use regulators, especially sulfur compounds such as mercaptoethanol, 2-ethylhexyl thioglycolate, thioglycolic acid or dodecylmercaptan, in order to reduce the K value. The K values are measured in accordance with Fikentscher, Cellulosechemie, Vol. 13 (1932) 58 to 64 at 25xc2x0 C. in 1% strength by weight ethanolic solution and are a measure of the molecular weight.
Such copolymers normally have glass transition temperatures of between 50 and 130xc2x0 C., in particular between 60 and 100xc2x0 C.
When the hairsetting composition is prepared by emulsion polymerization the resulting dispersion can be either incorporated directly into an aqueous hairsetting formulation or dried, for example by spraydrying, so that the hairsetting composition can be processed and used in powder form.
For use in the hairsetting compositions of the invention, the carboxyl groups of the copolymers thus obtained are usually neutralized with an alkali metal hydroxide or, preferably, with an amine, partially or completely, advantageously to the extent of from 5 to 100%, preferably from 30 to 95%. Neutralization is preferably carried out with
a mono-, di- or trialkanolamine having 2 to 5 carbon atoms in the alkanol radical, which may be in etherified form, for example mono-, di- and triethanolamine, mono-, di- and tri-n-propanolamine, mono-, di- and triisopropanolamine, 2-amino-2-methylpropanol and di(2-methoxyethyl)amine,
an alkanediolamine having 2 to 5 carbon atoms, for example 2-amino-2-methyl-1,3-propanediol and 2-amino-2-ethyl-1,3-propanediol, or
a primary, secondary or tertiary alkylamine having a total of 5 to 10 carbon atoms, for example N,N-diethylpropylamine.
Particularly good results are obtained with 2-amino-2-methylpropanol, triisopropanolamine and 2-amino-2-ethyl-1,3-propanediol.
Particularly suitable alkali metal hydroxides for the neutralization are sodium hydroxide and potassium hydroxide.
The hairsetting compositions according to the invention are employed, for example, as gels, lotions, mousses and, in particular, as hairsprays. Particularly preferred hairspray formulations are those comprising the following constituents:
from 0.1 to 20% by weight, preferably from 0.5 to 10% by weight, in particular from 2 to 10% by weight, of the partially or completely neutralized copolymer
from 1 to 99.9% by weight, preferably from 5 to 50% by weight, in particular from 10 to 40% by weight, of water
from 0 to 95% by weight, preferably from 20 to 60% by weight, in particular from 25 to 50% by weight, of a customary organic solvent such as, in particular, ethanol, isopropanol or dimethoxymethane, or else acetone, n-propanol, n-butanol, 2-methoxy-1-propanol, n-pentane, n-hexane, cyclohexane, n-heptane, n-octane or dichloromethane, or a mixture thereof
from 0 to 90% by weight, preferably from 30 to 80% by weight, in particular from 45 to 70% by weight, of a customary propellant such as propane, n-butane, isobutane, 2,2-dimethylbutane, n-pentane, isopentane, dimethyl ether, difluoroethane, fluorotrichloromethane, dichlorodifluoromethane or dichlorotetrafluoroethane, or a mixture thereof.
Compounds from the above especially employed as propellants are the hydrocarbons, especially propane, n-butane, n-pentane and mixtures thereof, and also dimethyl ether and difluoroethane. If desired, one or more of the abovementioned chlorinated hydrocarbons can be used as a component of propellant mixtures, but only in a minor proportion, for instance up to 20% by weight based on the propellant mixture.
The hairsetting compositions according to the invention are also particularly suitable for pump spray formulations without the addition of propellants, and for aerosol sprays with customary pressurized gases, such as nitrogen, compressed air or carbon dioxide as propellants.
These spray formulations may additionally contain minor amounts of perfume oils, for example from 0.1 to 0.5% by weight.
A standard aqueous spray formulation has, for example, the following composition:
from 2 to 10% by weight of the copolymer 100% neutralized with 2-amino-2-methylpropanol
from 10 to 76% by weight of ethanol
from 2 to 40% by weight of water
from 10 to 40% by weight of dimethyl ether
The copolymers present in the novel hairsetting compositions are notable for their high degree of compatibility with the apolar propellants in spray formulations, especially with hydrocarbons such as propane, n-butane or mixtures thereof. They give a good hairsetting effect, which is evident from the high values for curl retention which are usually above 80% in this context. The compositions are also notable for causing almost no sticking of the hair.
However, it is in those applications-related properties which were designated as being in need of improvement, when discussing the prior-art compositions at the outset, that the novel hairsetting compositions show particularly outstanding results. In alcohols such as ethanol or isopropanol and in mixtures of these alcohols with water, they give clear solutions. The clarity of the solutions is retained even if the solutions are employed in standard spray formulations together with propellants such as dimethyl ether. The novel hairsetting compositions can be washed out of the hair very readily. Hair treated with them is of heightened sleekness and has a pleasant natural handle. At the same time, the setting effect achieved is high, so that it is possible in principle to reduce the requisite amount of film-former in the hairspray formulation.
In order to tailor the properties of hairsetting compositions it can be advantageous to employ the copolymers of the invention as a mixture with other hairsetting polymers. Further suitable hairsetting polymers are commercially available polymers such as polyvinylpyrrolidones, copolymers of vinylpyrrolidone and vinyl acetate, copolymers of vinyl acetate and crotonic acid, copolymers of vinyl acetate, vinyl propionate and crotonic acid or copolymers based on acrylate/acrylamide. Such mixtures can contain the copolymers of the invention and the other hairsetting polymers in a weight ratio of from 1:99 to 99:1.