The invention relates to two-component preparations comprising components (I) and (II), wherein at least one component comprises epoxy compounds and the preparations cure by cationic polymerization, initiated by Lewis and/or Brxc3x6nsted acids, after mixing of the two components, the preparations comprising the Lewis and/or Brxc3x6nsted acids in the form of precursor compounds which are suitable for the formation of Lewis and/or Brxc3x6nsted acids.

The invention relates to two-component preparations comprising epoxy compounds, in particular for the preparation of dental compositions. The invention particularly relates to two-component dental compositions which comprise epoxy compounds and are cured by cationic polymerization.
An important parameter of multi-component dental compositions is their processing time. This is understood as meaning the time from the start of setting after mixing of the component to curing of the composition. After mixing the components of the dental composition, the user requires an exactly defined period of time in which he can handle the composition without problems. Directly after this period of time the composition should harden within the shortest time. A slow solidifying of the composition during processing or working is intolerable for the user.
Various systems which attempt to adjust the course of setting of a curing dental composition are known from the prior art.
DE-A-197 53 461 describes, for example, storage-stable cationically polymerizing preparations in which soluble and/or finely divided alkaline earth metal and/or alkali metal compounds allow adjustment of the course of setting. In the case of two-component formulations, the initiator system described there can comprise, inter alia, free Lewis or Brxc3x6nsted acids. A disadvantage of these preparations is that they allow only a very limited period of time for adjustment of the start of setting, and in addition if the concentration of alkaline earth or alkali metals is increased for the purpose of extending the setting range, they severely delay the end of setting and severely adversely impair the mechanical properties.
DE-A-197 42 980 indeed describes in principle cationically polymerizable compositions, but these are based on ROMP oligomers or polymers, it being possible for epoxy-functional comonomers to be added to the compositions. Free Lewis or Brxc3x6nsted acids are employed in the catalyst system mentioned. A disadvantage of this system is the fact that the course of setting cannot be adjusted. After the start of the polymerization, this starts to proceed and leads to a hard material with a low volume shrinkage within an extremely short time.
DE-A-195 02 751 describes photocurable model materials for dentistry in which Lewis acids can be formed by a suitable light source. Photocurable materials indeed in principle have a processing time of any desired length, but in practice this property would take effect only in a dark room. In the dental sector, however, work is carried out in without protection in daylight or under an intense artificial light source, which lead to a gradual solidifying of the dental material, as a result of which these initiation systems are not suitable for the preparation of dental materials with a widely adjustable processing time.
Further polymerizable compositions based on epoxides with Lewis or Brxc3x6nsted acids in free or reactive form as the catalyst or initiator system are known from DE-A-196 48 283. A disadvantage of these compositions in turn is that the setting characteristics cannot be adjusted.
The invention is based on the object of providing dental compositions which do not have the disadvantages from the prior art.
This object is achieved by two-component preparations, wherein at least one component comprises epoxy compounds and the preparations cure by cationic polymerization, initiated by Lewis and/or Brxc3x6nsted acids, after mixing of the two components, the preparations comprising the Lewis and/or Brxc3x6nsted acids in the form of precursor compounds which are suitable for the formation of Lewis and/or Brxc3x6nsted acids and which are formed by chemical reaction during or after mixing of the components.
The advantages of the dental compositions prepared from the preparations according to the invention lie in the exact adjustability of the processing time and in the outstanding physical values of the cured dental compositions.
In particular, when the dental compositions are used as model materials in dentistry for the production of working models, further advantages are found: Compared with gypsum, the compositions according to the invention show increased mechanical values, such as abrasion resistance, tensile strength and compressive strength. The detail reproduction of fine contours and grooves and the dimensional accuracy, which is largely influenced by the lowest possible polymerization shrinkage, are also considerably better. Compared with model materials known to date which are based on plastics and are distinguished by a rather cumbersome handling and/or by too long a setting phase compared with gypsum, the dental compositions according to the invention can be mixed automatically and the setting phase can be adjusted in an outstanding manner. The end of the setting phase determines the earliest possible point in time at which the model can be removed from the mould and worked further.
The preparations are also suitable for other dental applications where low shrinkage is an advantage, for example as materials for the production of temporary crowns and bridges and fixing cements.
The preparations according to the invention comprise two components (I) and (II).
The epoxy compounds and the Lewis and/or Brxc3x6nsted acids in the form of compounds which are capable of the formation of Lewis and/or Brxc3x6nsted acids and do not react with the epoxy compounds can be present in component (I) and/or in component (II) in any desired distribution.
Dental compositions obtained from the preparations according to the invention comprise, distributed over components (I) and (II), the following constituents:
(A) 10 to 80 wt. %, preferably 10 to 60 wt. %, of epoxy compounds,
(B) 0.01 to 20 wt. %, preferably 0.1 to 10 wt. %, of compounds which are capable of formation of Lewis or Brxc3x6nsted acids, and optionally free Lewis and/or Brxc3x6nsted acids,
(C) 10 to 89.99 wt. %, preferably 30 to 89.99 wt. %, of diluents,
(D) 0 to 79.99 wt. %, preferably 15 to 59.99 wt. %, of modifiers.
Epoxy compounds according to constituent (A) can be cycloaliphatic and/or aromatic and/or aliphatic epoxy compounds with at least two and/or at least four epoxy groups.
Cycloaliphatic epoxides can be, for example, the epoxides known from DE-A-196 48 283, which correspond to the following general formulae:
in which the symbols have the following meanings:
Z an aliphatic, cycloaliphatic or aromatic radical having 0 to 22, preferably 0 to 18 C atoms, or a combination of these radicals, it being possible for one or more C atoms to be replaced by O, Cxe2x95x90O, xe2x80x94O(Cxe2x95x90O)xe2x80x94, SiR2 and/or NR, wherein R is an aliphatic radical having 1 to 7 C atoms, it being possible for one or more C atoms to be replaced by O, Cxe2x95x90O and/or xe2x80x94O(Cxe2x95x90O)xe2x80x94,
A an aliphatic, cycloaliphatic or aromatic radical having 1 to 18, preferably 1 to 15 C atoms or a combination of these radicals, it being possible for one or more C atoms to be replaced by O, Cxe2x95x90O, xe2x80x94O(Cxe2x95x90O)xe2x80x94, SiR2 and/or NR, wherein R is an aliphatic radical having 1 to 7 C atoms, in which one or more C atoms can be replaced by O, Cxe2x95x90O and/or xe2x80x94O(Cxe2x95x90O)xe2x80x94,
B1, B2, D, E independently of one another, an H atom or an aliphatic radical having 1 to 9, preferably 1 to 7 C atoms, it being possible for one or more C atoms to be replaced by O, Cxe2x95x90O, xe2x80x94O(Cxe2x95x90O)xe2x80x94, SiR2 and/or NR, wherein R is an aliphatic radical having 1 to 7 C atoms, in which one or more C atoms can be replaced by O, Cxe2x95x90O and/or xe2x95x90O(Cxe2x95x90O)xe2x80x94,
X CH2, S or O,
n 2 to 7, preferably 2 to 5,
m 1 to 10, preferably 1 to 7,
p 1 to 5, preferably 1 to 4, and
q 1 to 5, preferably 1 to 4.
Low-viscosity epoxides such as are described in DE-A-196 48 283 can also be employed.
The epoxides known from U.S. Pat. Nos. 2,716,123, 2,985,667, 2,750,395, 2,863,881, 3,187,018, 5,085,124, EP-A-0 449 027 and EP-A-0 574 265 are also suitable, in particular epoxides of the following structural formulae
Combinations of aliphatic, cycloaliphatic or aromatic epoxides are possible. Cycloaliphatic epoxy compounds with at least two epoxy groups, cycloaliphatic epoxy compounds with at least four epoxy groups or the combination of cycloaliphatic epoxy compounds with two epoxy groups and cycloaliphatic epoxy compounds with at least four epoxy groups are preferably employed.
The Lewis and/or Brxc3x6nsted acids according to constituent (B) are formed by chemical reactions of selected constituents of the two components during or after mixing thereof. Free Lewis and/or Brxc3x6nsted acids such as are known from conventional systems can also be employed.
In the case where free Lewis or Brxc3x6nsted acids are additionally used, it has proved expedient to add the acids to that component which comprises no epoxy compounds. Where appropriate, to adjust the processing time it is expedient also to employ the substances for delaying cationic polymerization known from DE-A-197 53 461xe2x80x94which has not yet been published at the time of this Application.
Examples of free acids which may be mentioned are: BF3 or adducts thereof, such as, for example, BF3∃THF, BF3∃Et2O, AlCl3, FeCl3, HPF6, HAsF6, HSbF6 and HBF4.
Both components of the dental compositions according to the invention can additionally comprise certain contents of so-called photoinitiators which form Brxc3x6nsted or Lewis acids when irradiated with light of the wavelength range from 200 to 650 nm. Typical classes of compounds for these photoinitiators are onium salts, such as diazonium, sulphonium, iodonium and ferrocenium salts with complex anions of low nucleophilicity. These include, for example, diazonium compounds (U.S. Pat. No. 3,205,157), sulphonium compounds (U.S. Pat. No. 4,173,476) and iodonium compounds (U.S. Pat. Nos. 4,264,703, 4,394,493). In the examples mentioned, instructions are given to use ultraviolet light.
Derivatives of cyclopentadienyl-iron-arene complexes (EP-A-0 094 915, WO-96/03453, EP-A-0 661 324) can also be used. It is also possible to add xcex1-dicarbonyl compounds, for example camphorquinone, which act as sensitizers in the visible range. Combined preparations of camphorquinone and iodonium compounds are known from U.S. Pat. Nos. 5,554,676 and 4,828,583.
To produce the Brxc3x6nsted and/or Lewis acids, the components comprising photoinitiators are irradiated, before mixing, by lamps which emit light of the required wavelength range.
The photoinitiators are preferably employed in a component which comprises no epoxy compounds.
The Brxc3x6nsted and/or Lewis acids are produced by selected constituents which are stored separately in the two components and which react chemically with one another during or after mixing of the two components.
Typical examples of those reactions which can lead to the acids necessary for initiation of the polymerization of epoxy compounds are redox reactions using bisaryliodonium salts, reducing agents and copper complexes, and the dehalogenation of alkyl halides assisted by metal salts.
In the case of these latent initiation systems, it is possible to add the particular reaction partner both to the components comprising epoxy compounds and to the component which comprises no epoxy compounds.
In general, the distribution of the constituents of the latent initiation systems over the two components is undertaken such that premature polymerization of the epoxy compounds during storage of the two-component materials is reliably avoided.
This object is achieved, for example, by using components which cannot be polymerized by acids and which comprise the particularly critical constituent of the particular latent initiation system.
In the case of the formation of acids by redox reactions from bisaryliodonium salts, reducing agents and copper compounds, for example, it has thus proved expedient to store the bisaryliodonium salts and the reducing agents in a component which comprises no epoxy compounds. A further component then comprises the copper compounds together with the epoxy compounds.
The iodonium salts are present in the components to the extent of 0.01 to 20 wt. %, preferably 0.2 to 10 wt. %, based on the weight of the mixed material, the reducing agents also necessary are present to the extent of 0.01 to 10 wt. %, preferably 0.05 to 5 wt. %, based on the weight of the mixed material, and the copper compounds are present to the extent of 0.005 to 10 wt. %, preferably 0.01 to 5 wt. %, based on the weight of the mixed material.
The bisaryliodonium compounds, for example, which are known from U.S. Pat. Nos. 4,225,691 and 4,238,587 are suitable. Methods for the preparation of further diaryliodonium compounds are known from F. M. Beringer, R. A. Falk, M. Karmal, J. Lillien, G. Masullo, M. Mausner, E. Sommers, J. Am. Chem. Soc., 81, 342 (1958) and I. Mason, Nature, 139, 150 (1937).
Diaryliodonium compounds, which are known, inter alia, from DE-A-197 36 471, are particularly preferred. They have the following structure:
xe2x80x83[((R1)aAr1)xe2x80x94Ixe2x80x94(Ar2(R2)b)]+Yxe2x88x92
Ar1 and Ar2 independently of one another can be different, substituted or unsubstituted, fused or non-fused aromatic systems having 4 to 20 C atoms, such as, for example, phenyl, tolyl, cumyl, anisyl, chlorophenyl, nitrophenyl, naphthyl, thienyl, furanyl and pyrazolyl, wherein R1 and R2 are identical or different and independently of one another denote an H atom, an aliphatic radical having 1 to 19, preferably 1 to 9 C atoms, it being possible for one or more C atoms to be replaced by O, Cxe2x95x90O, xe2x80x94O(Cxe2x95x90O)xe2x80x94, F, Cl, Br, SiR33 and/or NR32, wherein R3 is an aliphatic radical having 1 to 7 C atoms, in which one or more C atoms can be replaced by O, Cxe2x95x90O and/or xe2x80x94O(Cxe2x95x90O)xe2x80x94, and a and b independently of one another can be 1 to 5. The aromatics Ar1 and Ar2 can be bonded to one another via R1 and/or R2.
The counter-anion Yxe2x88x92 is an anion of low nucleophilicity of the following structure:
KxLyxe2x88x92
wherein K is an element of main group IIII, V or VII, such as B, Al, P, Sb, As or I, and x can assume numerical values from 1 to 4. The L independently of one another denote aromatic, aliphatic, araliphatic or cycloaliphatic radicals having 1 to 25 C atoms, in which one or more C atoms can be substituted by F, Cl, Br or I, and y can assume numerical values from 0 to 6.
Preferred radicals L are pentafluorophenyl, tetrafluorophenyl, trifluorophenyl, fluorophenyl, phenyl, 4-trifluoromethylphenyl, 3,5-bis(trifluoromethyl)phenyl, 2,4,6-tris(trifluoromethyl)phenyl, fluorine and iodine.
Particularly preferred counter-anions Yxe2x88x92 are PF6xe2x88x92, AsF6xe2x88x92, SbF6xe2x88x92, B(C6F5)4xe2x88x92 and BF4xe2x88x92.
Further diaryliodonium compounds are also described, for example, in U.S. Pat. No. 4,246,703.
Particularly suitable diaryliodonium compounds are:
diphenyliodonium tetrafluoroborate
diphenyliodonium hexafluorophosphate
diphenyliodonium hexafluoroantimonate
diphenyliodonium tetrakis(pentafluorophenyl)borate
bis-(4-methylphenyl)iodonium hexafluorophosphate
bis-(4-methylphenyl)iodonium hexafluoroantimonate
bis-(4-methylphenyl)iodonium tetrakis(pentafluorophenyl)borate
phenyl-4-methylphenyliodonium hexafluorophosphate
phenyl-4-methylphenyliodonium hexafluoroantimonate
phenyl-4-methylphenyliodonium tetrakis(pentafluorophenyl)borate
phenyl-4-methoxyphenyliodonium hexafluoroantimonate
phenyl-4-methoxyphenyliodonium tetrakis(pentafluorophenyl)borate
phenyl-3-nitrophenyliodonium hexafluorophenylantimonate
phenyl-3-nitrophenyliodonium tetrakis(pentafluorophenyl)borate
bis(4-tert-butylphenyl)iodonium hexafluoroantimonate
bis(4-tert-butylphenyl)iodonium tetrakis(pentafluorophenyl)borate
phenyl-4-diphenyliodoinium hexafluoroantimonate
dinaphthyliodonium hexafluorophosphate
dinaphthyliodonium hexafluoroantimonate
dinaphthyliodonium tetrakis(pentafluorophenyl)borate
bis(4-dodecylphenyl)iodonium hexafluoroantimonate
bis(4-dodecylphenyl) tetrakis(pentafluorophenyl)borate
4-methylphenyl-4-isopropylphenyliodonium hexafluoroantimonate
4-methylphenyl-4-isopropylphenyliodonium tetrakis(pentafluorophenyl)borate
Reducing agents for carrying out the redox reaction for formation of acids are organic or inorganic compounds or polymers which are capable of lowering the charge of the heteroatom within the diaryliodonium salt. Compounds which are worth mentioning are ascorbic acid and derivatives thereof, in particular the palmitate, oleate and acetate. Tin(II) compounds can also be employed, for example Sn2+ carboxylates, in particular tin octoate, tin stearate, tin laurate, tin citrate, tin oxalate and tin benzoate. Among the organic compounds there may be mentioned xcex1-hydroxy compounds, for example ketones, in particular acyloins and benzoins. Also included are iron(II) compounds, for example ferrocenes, FeBr2 and FeCl2, reducing sugars, such as glucose, fructose and galactose, phenols, such as thiophenol, silanes and organosiloxanes.
Copper compounds are to be understood as meaning copper(I) and copper(II) compounds, for example salts of carboxylic acids and mineral acids, such as CuBr, CuCl, Cu(II) benzoate, Cu(II) citrate, Cu(II) formate, Cu(II) acetate, Cu(II) stearate, Cu(II) oleate, Cu(II) carbonate, Cu(II) gluconate, Cu(II) naphthenoate or Cu(II) acetylacetonate.
Copper chelates such as are mentioned in Cotton and Wilkinson, Advanced Inorganic Chemistry, 3rd Edition, Interscience Publishers, New York, 1972, pages 905 to 922 can also be used. Preferred copper chelates are those which can be incorporated or dispersed in the cationically polymerizable material in a sufficient amount. Copper acetylacetonate, copper salicylate, CuI(C6H5)3P, CuI(C2H5O)3P, CuCl2C2H8N2, [(Nxe2x80x94C4H9)4N]2CuCl4 etc. are particularly suitable.
Alkyl halides which are suitable for the dehalogenation of alkyl halides assisted by metal salts are described in xe2x80x9cMakromol. Chem.xe2x80x9d 178, 2139-2140 (1977) and in xe2x80x9cDie Makromolekulare Chemiexe2x80x9d 156 (1972) 325-328.
Compounds of the type R3Cxe2x80x94X, wherein X represents a halogen, preferably Cl and Br, and R represents any desired substituted or unsubstituted aliphatic or cycloaliphatic radical with a chain length of 1 to 15 C atoms, preferably 1 to 8 C atoms, or an aromatic radical substituted in any desired manner, are suitable in particular. Compounds with up to three different substituents on the central C atom can also be used.
Metal salts are understood as meaning inorganic or organic metal salts which are capable of abstracting the halogen from the compounds of the abovementioned type. Possible salts are those such as AgBF4, Ag SbF6, AlCl3, ZnCl2 and also BF3. Lewis acid compounds of the type M(III)X3, M(II)X2, M(V)X5 and possible adducts thereof with AgX are generally suitable. X here represents a halogen, preferably F, Cl or Br, and M represents a metal from the main or sub-group in question, preferably from main groups III and V, and in these preferably B, Al, Sb or As, and from sub-groups I, II, IVa and VIIIa, and in these preferably Cu, Ag, Zn, Fe, Co, Ni and Ti.
Diluents as flow improvers as constituent (C) are present in at least one of the two components of the preparations according to the invention. Diluents which are usually used as plasticizers can advantageously be employed.
Typical representatives are the esters of phthalic acid, such as di-2-ethylhexyl phthalate, or the esters of polybasic aliphatic acids, such as dioctyl adipate or acetyl tributylcitrate.
In addition, aliphatic and aromatic hydrocarbons with 6 to 30 C atoms which can be branched or unbranched are very suitable. Typical examples are polypropylene oils or polyisobutylene oils. Advantageously, aromatic hydrocarbons such as polyphenylene compounds, dibenzyltoluene and dibenzylphenyl methane are used.
Polyester polyols which can be prepared for example by polycondensation from low-molecular polyols and polycarboxylic acids and/or their anhydrides can also be used.
Typical representatives of this class are marketed by Hxc3xcls under the name Dynacoll. Preferably, polyester polyols whose molar masses are between 1000 and 5000 g/mol and hydroxyl equivalent masses of 500 to 2000 are used.
Particularly preferably, polyester polyols as they can be obtained through catalysed reactions of caprolactone with different starting alcohols can be used.
Typical representatives of this compound class are marketed by UCC under the name Tone or by Daicel under the name Placcel.
Polycaprolactone triols with molar masses of 200 to 1000 g/mol and polycaprolactone diols with molar masses of 300 to 2000 g/mol can be used.
Furthermore, polycarbonate diols with molar masses of 400 to 2000 g/mol and the general structure
can be used as diluents, X and Y being able to be identical or different and, independently of each other, mean alkylene, arylene, alkarylene, polyoxyalkylene and p can assume values between 1 and 50.
Furthermore, partly epoxidated polybutane diols can optionally be used which represent homopolymerisates of butadiene, which are terminated with OH groups, have molar masses of 1000 to 5000 g/mol and possess a high content of double bonds, which, through epoxidation, can optionally be partly converted to central aliphatic epoxide groups. Representatives of this compound class are marketed by Atochem under the name xe2x80x9cPoly bdxe2x80x9d.
Finally, polyether polyols of the general structure:
can also be used, m meaning an integer of 20 to 150, n an integer of 1 to 5 and R hydrogen or C1-C4 alkyl.
Preferably, mixed polyether polyols which are composed of propylene oxide units and/or ethylene oxide units and/or tetrahydrofurane units, are used.
Alkoxy-extended polyols such as for example ethoxylated Bisphenol A or propoxylated trimethylol propane can also advantageously be used.
To adjust the properties, it can be expedient to use mixtures of polyols of different average molar mass and different structure.
By modifiers are meant for example fillers. Fillers can be for example quartz, quartz powder, ground or reactive glasses, fragment polymerisates, silica gels as well as pyrogenic silicic acid or their granules, customary in the dental field. But other fillers such as for example finely-distributed metal or plastic powder, barium sulphate, titanium dioxide or in general finely-ground minerals are suitable. For better incorporation into the polymer matrix, it can be advantageous to hydrophobize the fillers. Hydrophobizing agents are silanes, for example glycidyloxypropyltrimethoxysilane. The maximum particle size of the inorganic fillers is 100 xcexcm, preferably 20 xcexcm.
As further modifiers, such as dyes or thixotropic agents, the substances customary in the dental engineering field can be used.
The two components of the preparations according to the invention can be stored separately, for example in double-chamber cartridges, and be mixed internally before use by eduction via a static or dynamic mixer. Hand-mixing variants are also possible.
The ratio between the component containing no epoxy compounds and the component containing epoxy compounds can be 1:10 to 1:1 and preferably 1:5 to 1:2.

Two-component preparations containing epoxy compounds


A method and system for the management of deletion requests for related documents in a content management system. When a user requests to delete a related document associated with a record in the content management system, the request determines whether there are other documents associated with the record, collects the documents and determines if any of the collected documents are parent documents, removes the association between each collected document and the record, and initiates a deletion process to delete the parent documents.

1. Technical Field
The present invention relates generally to a content management system, and more particularly to systems and methods for the management and deletion of related documents in a content management system.
2. Discussion of Related Art
A content management system is a system that can typically manage all types of electronic data objects including, for example, HTML and XML Web content, document images, office documents, e-mail messages, SMS messages, textual data, printed output, audio, video, and other digital representations of information (collectively referred to herein as "documents").
Conventional content management systems typically include a client access Application Program Interface (API), a library server, and one or more resource managers. The library server stores metadata relating to all documents stored in the resource manager, and also controls the particular documents that a particular client user can access. The resource manager is where the actual document or a record containing a pointer to the actual document is stored, and it utilizes a variety of services for storage management. Through the client API, the end user's application program can store, search for, mark-up and delete documents associated with records in the content management system, by accessing the resource manager.
In a conventional content management system, thousands of different documents may be stored, and the documents may be related, for example an email and its attachments may be stored as separate documents, as may a master document and its embedded sub-documents, or an original document and its versions. These related documents may provide challenges to the system, as when a user deletes only one version of a document, or only one sub-document and not the other sub-documents or the master document. These actions may cause a content management system to have incomplete data, or may cause errors in which deletion is prevented of related documents.

Management of deletion requests for related documents in a content management system

International Business Machines Corporation


This invention consists of a coating that is zebra mussel resistant and biofouling resistant without dependence on copper leaching. The coating is a solid solution of copper and nickel containing at least 65 percent copper. Application of the coating to stationary screens, traveling water screens, trash racks, louvers, and other components of water withdrawal and hydroelectric systems, netting and other porous materials used in barrier nets, fish nets, aquaculture, and fish hatcheries, the bottoms of water craft including recreational craft, boats, and ships and on bouys, piers and pilings and other materials that might benefit from resistance to the attachment of zebra mussels and other aquatic or marine organisms. Unlike coatings that depend on release of copper or copper ion for resistance, the rate of copper and copper ion release into the surrounding waters when measured using NSF International standard leach testing protocol and USEPA certified testing procedures is below the practicable detection limits of the equipment of 50 parts per billion.

Zebra mussels were first reported in U.S. waters in the mid to late 1980's. The mussels live in fresh water and are not native to North America. Initially they were identified in Lake Erie and there was much discussion of the possibility that they would not live in the other Great Lakes, nor would they survive in inland rivers, lakes, ponds, or streams. Viable populations of the mussels have since been found throughout the Great Lakes, as far north as the upper reaches of the St. Lawrence Seaway and the Mississippi River past Minneapolis, Minn. They are present in the Illinois River, the Hudson River, and the St. Croix River. They have been found as far south in the Mississippi River as Vicksburg, Miss. and are present in the Atchafalaya River Basin. They have been found in the Arkansas River, the Tennessee River, the Ohio River from Cairo, Ill. to its confluence with the Monongahela at Pittsburgh, Pa. and in the Monongahela near Monesson, Pa. They have also been found in 45 inland lakes in Michigan, 15 lakes each in Indiana and New York, 8 inland lakes in Ohio and 7 inland lakes in Wisconsin. They have also been found in Lake Champlain in Vermont and Lakes Saratoga and George in New York.
The spread of zebra mussels may be due, in part, to its reproductive cycle. It is reported that a fully mature female mussel may produce several hundred thousand eggs per reproductive season. The eggs are fertilized outside the mussels body and within a few days develop into free swimming larvae called veligers. The veligers grow into the typical double shelled mussel shape. Within a year, a zebra mussel can grow up to an inch and become sexually mature. The mussels can become established regardless of depth, light intensity or winter temperature. Colonies of the mussels seem to grow rapidly wherever oxygen and particulate food is available and where the water currents are generally less than 6 feet per second. The mussels have also been found to colonize soft, sandy or muddy bottoms. Extensive mats of mussels several inches thick have been found on lake bottoms and on the inside and outside of pipes.
The attachment and growth of zebra mussels on water intake screens, intake structures, intake pipelines, boat bottoms, fisherman's nets, fish barrier nets, and virtually any other surface in the infested waters is a significant problem in the fresh waters of the United States.
Similarly, biofouling, the attachment and growth of aquatic organisms on submerged surfaces in fresh water, sea water, and all the intermediate water mixtures can interfere with the water supply, increase energy and fuel use requirements, increase corrosion rates, and generally cause problems and increase maintenance requirements.
For years it has been recognized that, at many locations, when pure copper or alloys high in copper content were used in sea water or mixtures of sea water and fresh water, the attachment and growth of aquatic organisms on the material was much less severe than on other materials. At a minimum, the strength of the attachment bond of the organisms to the material was not as strong to the copper based materials as it was to other materials--making cleaning and removal of the organisms easier. In general, biofouling in fresh waters was not a major concern because the fresh water organisms didn't create major problems.
The mechanism by which these alloys afford resistance to the attachment and growth of organisms in the water has generally been believed to be as a result of the release of copper or copper ions into the water source. It is commonly suggested that the biofouling resistance of copper and copper alloys is the result of copper dissolving into the water and "poisoning" the organisms. It has been observed that when some corrosion products form on the surface or debris accumulates on the surface, organisms attach to the debris or to the portion of the surface with corrosion products.
Zebra mussel attachment resistance and resistance to biofouling organism attachment without dependence on copper leaching is the unique combination of characteristics of copper nickel materials. Copper and nickel form a solid solution throughout all combinations of concentrations from 100% copper and 0% nickel to 0% copper and 100% nickel. The characteristic resistance to corrosion in fresh and sea water of the individual elements seems to be enhanced when the two elements are combined in solid solution. When the copper concentration in the solid solution equals or exceeds 65% resistance to the attachment of marine organisms has been observed. When the concentration of copper in the solid solution is in the range of 90% resistance to the attachment of zebra mussels is observed. The precise mechanisms for this resistance to attachment is not known. It may be as a result of increases in the thermal or electrical conductivity of the material which increases with increasing copper concentration. It may be as a result of the surface energy of the material. It may be as a result of the formation of oxides of copper and nickel which form on the material surface. The great resistance to corrosion of the copper nickel solid solutions in fresh and sea waters is a strong indicator that the mechanism of resistance to organism attachment is not a result of copper or copper ion leaching into the water.
The arrival of zebra mussels in U.S. waters created a new and significant biofouling problem in our fresh waters. The mussels' behavior of growing rapidly, attaching and growing on virtually any object, and growing on other mussel shells has resulted in clogging of water intake pipes and trash racks; interference with the operation of locks and dams; fouling of boat bottoms, fish nets, and barrier nets; and build ups that weigh down bouys, reducing their visibility and effectiveness.
An array of control and management techniques have been applied to biofouling and zebra mussel control.
One technique is chemical control. This is particularly common on intake systems and intake pipelines. Chlorine, chlorine dioxide, potassium permanganate or other disinfection chemicals are introduced into the water to kill the zebra mussels and their larvae. Chemical control can be effective. Chemical control also has problems. It can be expensive to install and operate a chemical control system. Great care must be used in handling the chemicals as they can be toxic to humans, as well as desirable aquatic organisms such as fish. Care must be exercised in the dispersal of the chemicals. Release of the chemicals into the open water source could result in death to fish and other desirable creatures in the water. Management and control of the chemicals can also be a hazard to people using the water that has been treated. The natural action of the chemicals produces disinfectant by-products which can be dangerous, particularly in drinking water supplies.
A second technique is the use of very warm water. Subjecting zebra mussels to very warm water has been found to kill the mussels or inhibit their growth or reproductive systems. The use of heat can be effective. The use of heat also has its problems. Among these problems are the need for a source of a significant quantity of very warm water. A thermal electric generating station may have a source for such water, a municipal treatment plant might find the production of a sufficient quantity of very warm water excessively expensive. If a sufficient quantity of very warm water is available then the next problem with this technique must be addressed--getting the water to the point where control is desired. This can often be very expensive and difficult to accomplish. The use of very warm water for control also presents challenges with regard to environmental protection. Introduction of very warm water into the source water body can distort the natural ecosystem in the vicinity of the heated water discharge. Sudden loss of supply of the very warm water can result in thermal shock that kills fish that have been attracted to the area. The need for control of the zebra mussels must be balanced against the possible damage to fish and other aquatic organisms in the water body and the cost of producing and delivering the water.
A third technique is the use of pure copper as the material of construction. It has been reported that a copper alloy with copper concentration of 70% produced no noticeable reduction in zebra mussel attachment when compared to stainless steel or acrylic material. There are reports of copper alloy materials producing successful resistance to zebra mussel attachment and growth. The composition of the materials is not identified in the reports. Construction with materials containing high concentrations of copper, 70% or more in sea water and higher for zebra mussel control, may be an effective control technique. Construction with materials containing 70% or more copper also has problems. In general, these alloys are soft and not very strong. As a result, more material is required to provide the structural integrity required by the application. The materials are heavy--about 10% heavier than steel or stainless steel. When weight and strength are both design factors, the copper and copper alloy materials may require 50% to 100% greater weight of material than a similar construction in stainless steel. The materials are expensive, costing 21/2 to 5 times as much as stainless steel. The materials, particularly the alloys, are not always readily available in the required shapes, sizes or thicknesses to allow their use in construction. Copper and some of the alloys corrode readily in fresh water, sea water, and mixtures. As a result, these materials also have a limited service life--they waste away. They release copper and copper ion into the water. There are also some indications that the presence of corrosion products on the material surface interferes with their biofouling and zebra mussel resistance. Corrosion of the material creates an additional problem for municipal water systems. These systems must meet a lead-copper concentration standard at the water taps of their customers. Corrosion of copper materials in these systems could make meeting the standard more difficult.
A fourth technique is mechanical cleaning. Zebra mussels and other biofouling organisms can be removed by scraping, chipping, plucking, or blasting the material off the surface to be cleaned. Divers may work under water to remove the unwanted organisms or the surface of interest can be removed from the water, the organisms removed, and then the surfaces returned to the water. This technique can be effective but it also has its problems. The principal problems are cost and accessibility. In some cases it is very difficult for divers to be able to reach and clean the surfaces that need to be cleaned.
The fifth technique is the use of coatings. The coatings are of generally two forms: One form is copper-containing paints and organotin paints that have been used to control fouling on boat bottoms for years. A variety of antifouling paints have been developed for sea water applications and are currently being employed for zebra mussel resistance. This form of coating is designed to inhibit the attachment and growth of organisms on the coated surface through the release of material toxic to the organisms of concern. The second form is coatings that depend on slipperiness to minimize the strength of attachment of zebra mussels and biofouling. These coatings don't resist attachment, instead they are intended to make removal of the attached growth easier or depend on high local velocities to remove accumulated materials. Some work has been done on cladding of surfaces for control of marine biofouling. Thin layers of copper or copper alloy sheet are secured to the structure to be protected. Coating with copper bearing paints, organotin paints, antifouling paints, and cladding can be effective. These coatings also have problems. Paints tend to lose their biofouling resistance over time as the toxic components are lost and the paints need to be reapplied on a regular basis. In fact, the preponderance of these paints that have been demonstrated to be effective are "ablative" by design. The paints are designed to wear away so that new biofouling or zebra mussel resistant material is exposed. There are also problems with the binders used in the paint and difficulties with wear and abrasion of the coatings when the materials are placed in natural waters. These coatings are designed to have a relatively short term service life and intended to be re-applied on a regular basis to maintain resistance to attachment and growth. For both the coatings intended to provide resistance and the coatings intended to enhance the slipperiness of the surface, there are problems with the carriers used in the paints. The carriers are often volatile organic compounds and the application process must be done in such a way as to minimize the release of these VOC's to the surrounding environment. An additional problem with all of the paints is application--particularly to structures such as water intake screens with smaller openings. The paint has a tendency to block the openings in the screen and preclude water from entering the system. A further problem with many forms of coatings and cladding is that they are frequently thick and not particularly flexible. As a result, application of the coating on items such as fish nets makes it impossible for them to be used for their intended purpose.
Claddings are generally expensive, difficult to install, and, in some cases, impossible to install in such a way as to provide the desired coverage and protection.

Aquatic organism and corrosion resistant coating and method for producing the coating


A soluble polyimide derived from dehydration of a polyamic acid which is the liquid phase condensation reaction product of a solution in aprotic solvent of approximately equimolar amounts of aromatic dianhydride and aromatic diamine. At least 50 mole % of the dianhydride must have ring linkages which prevent conjugation between the rings and at least 20 mole % of the diamine must contain electron withdrawing groups.

Polyimides find extensive use in electronic applications where they are useful in forming dielectric films on electrical and electronic devices such as capacitors and semiconductors. Typical uses for polyimides include protective coatings for semiconductors, dielectric layers for multilayer integrated circuits, high temperature solder masks, bonding multilayer circuits, final passivating coatings on electrical electronic devices and the like.
It is well known in the polymer art to make thermally stable all-aromatic polyimides by the condensation polymerization of dianhydrides and diamines to form polyamic acid. Such polyimide precursors are disclosed inter alia in U.S. Pat. No. 3,179,634 to Edwards. These polyamic acids are readily dehydrated to the corresponding polyimides by heating at high temperatures, e.g. 300.degree. to 400.degree. C. However, these all-aromatic polyimides known heretofore have all been insoluble and, therefore, protective films could not be coated in the polyimide form. Therefore, it has been prior practice to use instead the precursor polyamic acids which had the advantage of being readily soluble in many aprotic solvents. Such polyamic acid solutions were then coated to form the appropriate film and converted to the corresponding polyimide by heating the film at high temperature to effect volatilization of the solvent and dehydration of the polyamic acid to form the polyimide. However, polyamic acid solutions tend to have substantial viscosity instability which causes them to become lower in viscosity upon storage at room temperature. Therefore, it would be advantageous to have an already formed soluble polyimide which is viscosity stable and, because it requires no conversion, can be processed at relatively low temperatures, e.g., below 200.degree. C.


A thermoplastic, flame-retardant moulding composition having improved mechanical properties is disclosed. The composition contains 40 to 99 parts by weight of a thermoplastic polycarbonate or polyester carbonate, 0.5 to 60 parts by weight of a graft polymer, 0 to 45 parts by weight of a thermoplastic vinyl copolymer, 0.5 to 20 parts by weight of a mixture of at least one mono- and at least one oligo-phosphorus conforming to the general formula

The present invention relates to polycarbonate-ABS moulding compositions which are made flame-retardant with phosphorus compounds, and which exhibit an excellent level of mechanical properties, particularly a considerably improved ultimate tensile strength and yield stress as well as an outstanding tensile modulus of elasticity.
EP-A-0 363 608 describes polymer mixtures comprising an aromatic polycarbonate and a copolymer or graft copolymer containing styrene, as well as oligomeric phosphates as flame retardant additives. The level of mechanical properties of these mixtures is often unsatisfactory for certain purposes of use.
EP-A-0 704 488 describes moulding compositions comprising an aromatic polycarbonate, copolymers which contain styrene, and graft polymers with a special graft base, in defined quantitative ratios. These moulding compositions have a very good notched bar impact strength, and can optionally be made flame-retardant with phosphorus compounds. Their level of mechanical properties is not always satisfactory for the production of mouldings which are subject to intensified elastic loading.
The object of the present invention is therefore to provide flame-retardant polycarbonate-ABS moulding compositions which, in addition to the requisite high level of flame-retardancy, have an excellent ultimate tensile strength and an excellent tensile modulus of elasticity.
It has now been found that PC/ABS moulding compositions, which contain phosphorus compounds according to component D (see below) and a graft polymer comprising a graft base of defined particle size, can be processed to form mouldings with a very good level of mechanical properties, particularly under intensified elastic loading also.
The present invention therefore relates to a flame-retardant thermoplastic moulding composition containing
A. 40 to 99, preferably 60 to 98.5 parts by weight, of an aromatic polycarbonate or polyester carbonate
B. 0.5 to 60, preferably 1 to 40, particularly 2 to 25 parts by weight, of a graft polymer of
B.1 5 to 95, preferably 30 to 80% by weight, of one or more vinyl monomers on
B.2 95 to 5, preferably 20 to 70% by weight of one or more graft bases with a glass transition temperature  less than 0xc2x0 C., preferably  less than xe2x88x9220xc2x0 C., and an average particle size (d50 value) of 0.20 to 0.35 xcexcm, preferably 0.25 to 0.30 xcexcm
C. 0 to 45, preferably 0 to 30, most preferably 2 to 25 parts by weight of a thermoplastic vinyl (co)polymer
D. 0.5 to 20 parts by weight, preferably 1 to 18 parts by weight, most preferably 2 to 15 parts by weight, of at least one mono- and at least one oligophosphorus compound of general formula (I)
wherein
R1, R2, R3 and R4, independently of each other, each denote a C1 to C8 alkyl which is optionally halogenated in each case, a C5 to C6 cycloalkyl, C6 to C20 aryl or C7 to C20 aralkyl, which are each optionally substituted by an alkyl, preferably a C1-C4 alkyl and/or by a halogen, preferably chlorine or bromine,
n denotes 0 or 1, which are independent of each other.
N denotes 0 to 30, and
X denotes a mono- or polynuclear aromatic radical containing 6 to 30 C atoms; and
E. denotes 0.05 to 5 parts by weight, preferably 0.1 to 1 parts by weight, most preferably 0.1 to 0.5 parts by weight, of a fluorinated polyolefine,
wherein the sum of all the parts by weight of A+B+C+D+E is 100.
Moulding compositions which are particularly preferred are those in which the ratio by weight of components B:C is between 2:1 and 1:4, preferably between 1:1 and 1:3.
In the moulding compositions according to the invention, component D is preferably present as a mixture of 10 to 90% by weight, preferably 12 to 40% by weight, of at least one monophosphorus compound of formula (I), and 10 to 90% by weight, preferably 60 to 88% by weight, with respect to the total amount of phosphorus compounds in each case, of at least one oligophosphorus compound of formula (I), wherein the mixture has an average N of 0.3 to 20, preferably 0.5 to 10, most preferably 0.5 to 6.
Aromatic polycarbonates and/or aromatic polyester carbonates according to component A which are suitable according to the invention are known from the literature or can be produced by methods known from the literature (for example, for the production of aromatic polycarbonates, see Schnell, xe2x80x9cChemistry and Physics of Polycarbonatesxe2x80x9d, Interscience Publishers, 1964, as well as DE-AS 1 495 626, DE-OS 2 232 877, DE-OS 2 703 376, DE-OS 2 714 544, DE-OS 3 000 610 and DE-OS 3 832 396; for the production of aromatic polyester carbonates see DE-OS 3 077 934 for example).
The production of aromatic polycarbonates is effected, for example, by the reaction of diphenols with carbonic acid halides, preferably phosgene, and/or with aromatic dicarboxylic acid dihalides, preferably benzenedicarboxylic acid dihalides, by the phase boundary method, optionally with the use of chain terminators e.g. monophenols, and optionally with the use of trifunctional branching agents or branching agents with a functionality higher than three, for example triphenols or tetraphenols.
Diphenols for the production of the aromatic polycarbonates and/or aromatic polyester carbonates are preferably those of formula (II)
wherein
A denotes a single bond, a C1-C5 alkylene, a C2-C5 alkylidene, a C5-C6 cycloalkylidene, xe2x80x94Oxe2x80x94, xe2x80x94SOxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94SO2xe2x80x94, or a C6-C12 arylene, on to which other aromatic rings, which optionally contain hetero atoms, can be condensed,
or a radical of formula (III) or (IV)
B denotes hydrogen a C1-C12 alkyl, preferably methyl, or a halogen, preferably chlorine and/or bromine, in each case
x is 0.1 or 2, independently of each other, in each case.
p is 1 or 0, and
R5 and R6, which are independent of each other and are individually selectable for each X1, denote hydrogen or a C1-C6 alkyl, preferably hydrogen, methyl or ethyl.
X1 denotes carbon, and
m denotes an integer from 4 to 7, preferably 4 or 5, with the proviso that R5 and R6 simultaneously denote an alkyl on at least one X1 atom.
The preferred diphenols are hydroquinone, resorcinol, dihydroxydiphenols, bis-(hydroxyphenyl)-C1-C5-alkanes, bis-(hydroxyphenyl)-C5-C6-cycloalkanes, bis(hydroxyphenyl)-ethers, bis-(hydroxyphenyl)-sulphoxides, bis-(hydroxyphenyl)ketones, bis-(hydroxyphenyl)-sulphones and xcex1,xcex1xe2x80x2-bis-(hydroxyphenyl)-diisopropylbenzenes, as well as derivatives thereof which have brominated and/or chlorinated nuclei.
Diphenols which are particularly preferred are 4,4xe2x80x2-dihydroxydiphenyl, bisphenol A, 2,4-bis(4-hydroxyphenyl)-2-methylbutane, 1,1-bis-(4-hydroxyphenyl)-cyclohexane, 1,1-bis-4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4,-dihydroxydiphenyl sulphide and 4,4,-dihydroxydiphenyl-sulphone, as well as di- and tetrabrominated or chlorinated derivatives thereof, such as 2,2-bis(3-chloro-4-hydroxyphenyl)-propane, 2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane or 2,2-bis-(3,5-dibromo-4-hydroxyphenyl)-propane.
2,2-bis-(4-hydroxyphenyl)-propane (bisphenol A) is particularly preferred.
The diphenols can be used individually or as arbitrary mixtures.
The diphenols are known from the literature or can be obtained by methods known from the literature.
Examples of suitable chain terminators for the production of the thermoplastic, aromatic polycarbonates include phenol, p-chlorophenol, p-tert.-butylphenol or 2,4,6-tribromophenol, as well as long chain alkylphenols such as 4-(1,3-tetramethyl-butyl)-phenol according to DE-OS 2 842 005 or monoalkylphenols or dialkylphenols which contain a total of 8 to 20 C atoms in their alkyl substituents, such as 3,5-di-tert.-butyl-phenol, p-iso-octylphenol, p-tert.-octylphenol, p-dodecylphenol, 2-(3,5-dimethylheptyl)-phenol and 4-(3,5-dimethylheptyl)-phenol. The amount of chain terminators used is generally between 0.5 mole % and 10 mole % with respect to the molar sum of the diphenols used in each case.
The thermoplastic, aromatic polycarbonates have mean weight average molecular weights (Mw, as measured by ultracentrifuging or by scattered light measurements) of 10,000 to 200,000, preferably 20,000 to 80,000.
The thermoplastic, aromatic polycarbonates can be branched in the known manner, in fact by the incorporation of 0.05 to 2.0 mole %, with respect to the sum of the diphenols used, of trifunctional compounds or of compounds with a functionality higher than three, for example those which contain three or more phenolic groups.
Both homopolycarbonates and copolycarbonates are suitable. For the production of copolycarbonates according to component A) in accordance with the invention, 1 to 25% by weight, preferably 2.5 to 25% by weight (with respect to the total amount of diphenols to be used) of polydiorganosiloxanes comprising hydroxy-aryloxy terminal groups can also be used. These are known (see, for example, U.S. Pat. No. 3,419,634) or can be produced by methods known from the literature. For example, the production of copolycarbonates which contain polydiorganosiloxanes is described in DE-OS 3 334 782.
Apart from bisphenol A homopolycarbonates, the preferred polycarbonates are the copolycarbonates of bisphenol A with up to 15 mole %, with respect to the molar sums of the diphenols, of other diphenols which are cited as preferred or particularly preferred, in particular 2,2-bis(3,5-dibromo-4-hydroxyphenyl)-propane.
The preferred aromatic dicarboxylic acid dihalides for the production of the aromatic polyester carbonates are the diacid dichlorides of isophthalic acid, terephthalic acid, diphenyl ether-4,4xe2x80x2-dicarboxylic acid and naphthalene-2,6-dicarboxylic acid.
Mixtures of the diacid dichlorides of isophthalic acid and terephthalic in a ratio between 1:20 and 20:1 are particularly preferred.
A carbonic acid halide, preferably phosgene, is used in conjunction as a difunctional acid derivative during the production of the polyester carbonates.
Apart from the aforementioned monophenols, suitable chain terminators for the production of the aromatic polyester carbonates include chlorocarboxylic acid esters thereof, as well as the acid chlorides of aromatic monocarboxylic acids which may optionally be substituted by C1-C22 alkyl groups, or by halogen atoms, and also include aliphatic C2-C22 monocarboxylic acid chlorides.
The amount of chain terminator is 0.1 to 10 mole % in each case, with respect to the moles of diphenols in the case of phenolic chain terminators and with respect to the moles of dicarboxylic acid dichlorides in the case of monocarboxylic acid chloride chain terminators.
The aromatic polyester carbonates may also contain incorporated hydroxycarboxylic acids.
The aromatic polyester carbonates may be either linear or may be branched in the known manner (see DE-OS 2 940 024 and DE-OS 3 007 934 in this respect also).
Tri- or multi-functional carboxylic acid chlorides can be used as branching agents, such as trimesic acid trichloride, cyanuric acid trichloride, 3,3xe2x80x2-,4,4xe2x80x2-benzophenonetetracarboxylic acid tetrachloride, 1,4,5,8-naphthalene-tetracarboxylic acid tetrachloride or pyromellitic acid tetrachloride for example, in amounts of 0.01 to 1.0 mole % (with respect to the dicarboxylic acid dichlorides used) or tri- or multi-functional phenols such as phloroglucinol, 4,6-dimethyl-2,4,6,-tri-(4-hydroxyphenyl)-heptene-2, 4,4-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptane, 1,3,5-tri-(4-hydroxy-phenyl)-benzene, 1,1,1-tri-(4-hydroxy-phenyl)-ethane, tri-(4-hydroxyphenyl)-phenyl-methane, 2,2-bis[4,4-bis(4-hydroxyphenyl)-cyclohexyl]-propane, 2,4-bis(4-hydroxyphenyl-isopropyl)-phenol, tetra-(4-hydroxyphenyl)-methane, 2,6-bis(2-hydroxy-5-methyl-benzyl)4-methyl-phenol, 2-(4-hydroxyphenyl)-2-(2,4-dihydroxyphenyl)-propane, tetra-(4-[4-hydroxyphenyl-isopropyl]-phenoxy)-methane or 1,4-bis[4,4xe2x80x2-dihydroxytriphenyl)-methyl]benzene, in amounts of 0.01 to 1.0 mole % with respect to the diphenols used. Phenolic branching agents can be placed in the reaction vessel with the diphenols. Acid chloride branching agents can be introduced together with the acid chlorides.
The proportion of carbonate structural units in the thermoplastic, aromatic polyester carbonates can be arbitrarily varied. The content of carbonate groups is preferably up to 100 mole %, particularly up to 80 mole %, most preferably up to 50 mole %, with respect to the sum of ester groups and carbonate groups. Both the ester and the carbonate fraction of the aromatic polyester carbonates can be present in the form of blocks, or can be randomly distributed in the condensation polymer.
The relative solution viscosity (xcex7rel)of the aromatic polyester carbonates falls within the range of 1.18 to 1.4, preferably 1.22 to 1.3 (as measured on solutions of 0.5 g polyester carbonate in 100 ml methylene chloride at 25xc2x0 C.).
The thermoplastic, aromatic polycarbonates and polyester carbonates can be used on their own or in any mixture with each other.
Component B comprises one or more graft copolymers of
B.1 5 to 95, preferably 30 to 80% by weight, of one or more vinyl monomers on
B.2 95 to 5, preferably 70 to 20% by weight of one or more graft bases with a glass transition temperature less than 0xc2x0 C. preferably  less than xe2x88x9220xc2x0 C. and an average particle size (d50 value) of 0.20 to 0.35 xcexcm.
Monomers B.1 are preferably mixtures of
B1.1 50 to 99 parts by weight of aromatic vinyl compounds and/or aromatic vinyl compounds with substituted nuclei (such as styrene, xcex1-methylstyrene, p-methylstyrene or p-chlorostyrene for example) and/or C1-C4 alkyl esters of (meth)acrylic acid (such as methyl methacrylate or ethyl methacrylate for example), and
B1.2 1 to 50 parts by weight vinyl cyanides (unsaturated nitriles, such as acrylonitrile and methacrylonitrile for example) and/or C1-C4 alkyl esters of (meth)acrylic acid (such as methyl methacrylate, n-butyl acrylate and t-butyl acrylate for example) and/or derivatives (such as anhydrides and imides) of unsaturated carboxylic acids (for example maleic anhydride and N-phenylmale inimide).
The preferred monomers B.1.1 are selected from at least one of the monomers styrene, xcex1-methylstyrene and methyl methacrylate. The preferred monomers B.1.2 are selected from at least one of the monomers acrylonitrile, maleic anhydride and methyl methacrylate.
The monomers which are particularly preferred are styrene as B.1.1 and acrylonitrile as B.1.2.
Examples of suitable graft bases B.2 for graft polymers B. include diene rubbers, EP(D)M rubbers, namely those based on ethylene/propylene- and optionally diene, acrylate, polyurethane, silicone, chloroprene and ethylene/vinyl acetate rubbers.
The preferred graft bases B.2 are diene rubbers (e.g. those based on butadiene, isoprene etc.) or mixtures of diene rubbers or copolymers of diene rubbers or mixtures thereof with other copolymerisable monomers (e.g. according to B.1.1 and B.1.2), with the proviso that the glass transition temperature of component B.2 is less than 0xc2x0 C.
Pure polybutadiene rubber is particularly preferred.
Examples of particularly preferred polymers B. include ABS polymers (emulsion, bulk and suspension ABS), such as those which are described, for example, in DE-OS 2 035 390 (=US-PS 3 644 574) or in DE-OS 2 248 242 (=GB-PS 1 409 275) or in Ullmann. Enzyklopxc3xa4ddie der Technischen Chemie, Volume 19 (1980), page 280 et seq. The gel content of graft base B.2 is at least 30% by weight, preferably at least 40% by weight (as measured in toluene), and the average particle diameter of graft base B.2 is 0.20 to 0.35 xcexcm, preferably 0.25 to 0.30 xcexcm.
Graft copolymers B. are produced by radical polymerisation, e.g. by emulsion, suspension, solution or bulk polymerisation, preferably by emulsion polymerisation.
ABS polymers, which are produced by redox initiation with an initiator system comprising an organic hydroperoxide and ascorbic acid according to U.S. Pat. No. 4,937,285, are particularly suitable graft rubbers.
Suitable acrylate rubbers according to B.2 of polymer B are preferably polymers of acrylic acid alkyl esters, optionally with up to 40% by weight, with respect to B.2, of other polymerisable, ethylenically unsaturated monomers. The preferred polymerisable acrylic acid esters include C1-C8 alkyl esters, for example methyl, ethyl, butyl, n-octyl and 2-ethylhexyl esters: halogenoalkyl esters, preferably halogeno-C1-C8-alkyl esters such as chloroethyl acrylate, as well as mixtures of these monomers.
Monomers with more than one polymerisable double bond can be copolymerised to provide crosslinking. The preferred examples of crosslinking monomers are the esters of unsaturated monocarboxylic acids containing 3 to 8 C atoms and unsaturated monohydric alcohols containing 3 to 12 C atoms, or saturated polyols containing 2 to 4 OH groups and 2 to 20 C atoms, such as ethylene glycol dimethacrylate or allyl methacrylatc for example; multiply-unsaturated heterocyclic compounds, such as trivinyl and triallyl cyanurate for example; polyfunctional vinyl compounds such as di- and trivinylbenzenes; and also triallyl phosphate and diallyl phthalate.
The preferred crosslinking monomers are allyl methacrylate, ethylene glycol dimethacrylate, diallyl phthalate and heterocyclic compounds which contain at least 3 ethylenically unsaturated groups.
Crosslinking monomers which are particularly preferred are the cyclic monomers triallyl cyanurate, triallyl isocyanurate, triacryloyl hexahydro-s-triazine and triallylbenzenes. The amount of crosslinked monomer is preferably 0.02 to 5, particularly 0.05 to 2% by weight, with respect to graft base B.2.
For cyclic crosslinking monomers containing at least 3 ethylenically unsaturated groups, it is advantageous to restrict the amount thereof to less than 1% by weight of graft base B.2.
Examples of preferred xe2x80x9cotherxe2x80x9d polymerisable, ethylenically unsaturated monomers which can optionally be employed apart from acrylic acid esters for the production of graft base B.2 include acrylonitrile, styrene, xcex1-methylstyrene, acrylamides, vinyl-C1-C6-alkyl ethers, methyl methacrylate and butadiene. The acrylate rubbers which are preferred as graft base B.2 are emulsion polymers which have a gel content of at least 60% by weight.
Other graft bases which are suitable according to B.2 are silicone rubbers with graft-active sites, such as those described in DE-OS 3 704 657, DE-OS 3 704 655, DE-OS 3 631 540 and DE-OS 3 631 539.
The gel content of graft base B.2 is determined at 25xc2x0 C. in a suitable solvent (M. Hoffmann. H. Krxc3x6mer. R. Kuhn, Polymeranalytik I and II, Georg Thieme-Verlag, Stuttgart 1977).
The average particle size d50 is the diameter above and below which 50% of the particles lie in each case. It can be determined by means of ultracentrifuge measurements (W Scholtan, H. Lange, Kolloide, Z. and Z. Polymere 250 (1972), 782-1796).
Since, as is known, the graft monomers are not actually grafted completely on to the graft base during the grafting reaction, graft polymers B. are also to be understood according to the invention to include those products which are obtained by (co)polymerisation of the graft monomers in the presence of the graft base and which occur in conjunction during processing.
Component C comprises one or more thermoplastic vinyl (co)polymers.
Polymers which are suitable as component C. are polymers of at least one monomer from the group comprising aromatic vinyl compounds, vinyl cyanides (unsaturated nitrites), (meth)acrylic acid (C1-C8)-alkyl esters, unsaturated carboxylic acids, as well as derivatives (such as anhydrides and imides) of unsaturated carboxylic acids. (Co)polymers which are particularly suitable are those of
C.1 50 to 99, preferably 60 to 80 parts by weight of aromatic vinyl compounds and/or aromatic vinyl compounds which comprise substituted nuclei, such as styrene, xcex1-methylstyrene, p-methylstyrene, p-chlorostyrene) and/or methacrylic acid (C1-C4)-alkyl esters, such as methyl methacrylate or ethyl methacrylate for example), and
C.2 1 to 50, preferably 20 to 40 parts by weight vinyl cyanides (unsaturated nitrites) such as acrylonitrile and methacrylonitrile and/or (meth)acrylic acid (C1-C8) esters (such as methyl methacrylate, n-butyl acrylate or t-butyl acry late for example) and/or unsaturated carboxylic acids (such as maleic acid) and/or derivatives (such as anhydrides and imides) of unsaturated carboxylic acids (for example maleic anhydride and N-phenyl-maleinimide).
(Co)polymers C are resin-like, thermoplastic and free from rubber.
The copolymer of C.1 styrene and C.2 acrylonitrile is particularly preferred.
The (co)polymers according to C are known, and can be produced by radical polymerisation, particularly by emulsion, suspension, solution or bulk polymerisation. The (co)polymers according to component C preferably have molecular weights Mw (weight average, determined by light scattering or sedimentation) between 15,000 and 200,000.
(Co)polymers according to component C are frequently produced as by-products during the graft polymerisation of component B, particularly when large amounts of monomers B.1 are grafted on to small amounts of rubber B.2. The amount of C which can also optionally be used according to the invention does not include these by-products of the graft polymerisation of B.
However, component C should be present in the moulding compositions according to the invention for certain purposes of use.
If component C is present in the moulding compositions, the ratio by weight of components B:C should be between 2:1 and 1:4, preferably between 1:1 and 1:2, in order to obtain the desired level of mechanical properties for certain purposes of use.
Component D is a mixture of at least one mono- and of at least one oligomeric phosphorus compound of formula (I).
In this formula, R1, R2, R3 and R4 have the meanings given above, R1, R2, R3 and R4 preferably denote, independently of each other, C1-C4 alkyl, phenyl, naphthyl or phenyl-C1-C4-alkyl. The aromatic groups R1, R2, R3 and R4 may themselves be substituted with halogen and/or alkyl groups, preferably chlorine, bromine and/or C1-C4-alkyl. The most preferred aryl radicals are cresyl, phenyl, xylenyl, propylphenyl or butylphenyl, as well as the corresponding brominated and chlorinated derivatives thereof.
X in formula (I) denotes a mono- or polynuclear aromatic radical containing 6 to 30 C atoms. This is derived from diphenols, such as diphenyl-phenol, bisphenol A, resorcinol or hydroquinone for example, or from chlorinated or brominated derivatives thereof.
n in formula (I) can be 0 or 1, independently of each other, n is preferably equal to 1.
N represents values of 0 to 30, and preferably represents an average value of 0.3 to 20, most preferably 0.5 to 10, particularly 0.5 to 6.
Mixtures are used as component D according to the invention which preferably comprise 10 to 90% by weight, most preferably 12 to 40% by weight, of at least one monophosphorus compound of formula (I) and of at least one oligomeric phosphorus compound, or which comprise a mixture of oligomeric phosphorus compounds in amounts of 10 to 90% by weight, preferably 60 to 88% by weight, with respect to the total amount of phosphorus compounds.
Particular monophosphorus compounds of formula (I) are tributyl phosphate, tris-(2-chloroethyl)-phosphate, tris-(2,3-dibromopropyl) phosphate, triphenyl phosphate, tricresyl phosphate, diphenyl cresyl phosphate, diphenyl octyl phosphate, diphenyl-2-ethyl-cresyl phosphate, tri-(isopropylphenyl) phosphate, halogen-substituted aryl phosphates, methylphosphonic acid dimethyl ester, methylphosphonic acid diphenyl ester, phenylphosphonic acid diethyl ester, triphenylphosphine oxide or tricresylphosphine oxide.
The mixtures of monomeric and oligomeric phosphorus compounds of formula (I) have average N values of 0.3 to 20, preferably 0.5 to 10, particularly 0.5 to 6.
The phosphorus compounds according to component D are known (see, for example, EP-A 363 608, EP-A 640 655) or can be prepared in an analogous manner by known methods (e.g. Ullmanns Encyklopxc3xa4die der technischen Chemie, Volume 8, page 301 et seq. 1979; Houben-Weyl, Methoden der organischen Chemie, Volume 12/1 page 43; Beilstein Volume 6, page 177).
Fluorinated polyolefines E) are of high molecular weight and have glass transition temperatures above xe2x88x9230xc2x0 C. generally above 100xc2x0 C. They preferably have fluorine contents of 65 to 76, particularly 70 to 76% by weight, and average particle diameters d50 of 0.05 to 1000, preferably 0.08 to 20 xcexcm. In general, fluorinated polyolefines E) have a density of 1.2 to 2.3 g/cm3. The preferred fluorinated polyolefines E) are polytetrafluoroethylene, polyvinylidene fluoride, and tetrafluoroethylene (hexafluoropropylene) and ethylene/tetrafluoroethylene copolymers. These fluorinated polyolefines are known (see xe2x80x9cVinyl and Related Polymersxe2x80x9d by Schildknecht, John Wiley and Sons, Inc., New York, 1962, pages 484-494; xe2x80x9cFluoropolymersxe2x80x9d by Wall, Wiley-Interscience, John Wiley and Sons, Inc., New York, Volume 13, 1970, pages 623-654; xe2x80x9cModern Plastics Encyclopediaxe2x80x9d, 1970-1971, Volume 47, No.10 A, October 1970. McGraw-Hill, Inc., New York, pages 134 and 774; xe2x80x9cModern Plastics Encyclopediaxe2x80x9d, 1975-1976. October 1975, Volume 52, No.10 A, McGraw-Hill, Inc., New York, pages 27, 28 and 472; and U.S. Pat. Nos. 3,671,487, 3,723,373 and 3,838,092).
They can be produced by known methods, for example by the polymerisation of tetrafluoroethylene in aqueous medium with a catalyst which forms free radicals, for example sodium, potassium or ammonium peroxydisulphate, at pressures of 7 to 71 kg/cm2 and at temperatures of 0 to 200xc2x0 C., preferably at temperatures of 20 to 100xc2x0 C. (for further details, for example, see U.S. Pat. No. 2,393,967). Depending on the form in which they are used, the density of these materials may be between 1.2 and 2.3 g/cm3, and their average particle size may be between 0.5 and 1000 xcexcm.
The polyolefines E) which are preferred according to the invention are tetrafluoroethylene polymers with average particle diameters of 0.05 to 20 xcexcm, preferably 0.08 to 10 xcexcm, and a density of 1.2 to 1.9 g/cm3. They are preferably used in the form of a coagulated mixture of emulsions of tetrafluoroethylene polymers E) with emulsions of graft polymers B).
Tetrafluoroethylene polymers with average particle diameters of 100 to 1000 xcexcm and densities of 2.0 g/cm3 to 2.3 g/cm3 are suitable fluorinated polyolefines E) which can be used in powder form.
To prepare a coagulated mixture of B) and E), an aqueous emulsion (latex) of a graft polymer B) is first mixed with a finely dispersed emulsion of a tetraethylene polymer E); suitable tetrafluoroethylene polymer emulsions usually have solids contents of 30 to 70% by weight, particularly 50 to 60% by weight, preferably 30 to 35% by weight.
The quantitative data in the description of component B may include the proportion of graft polymer for the coagulated mixture of graft polymer and fluorinated polyolefines.
In the emulsion mixture, the equilibrium ratio of graft polymer B to tetrafluoroethylene polymer E is 95:5 to 60:40. The emulsion mixture is subsequently coagulated in the known manner, for example by spray-drying, freeze-drying, or by coagulation by means of adding inorganic or organic salts, acids or bases, or organic solvents which are miscible with water, such as alcohols or ketones, preferably at temperatures of 20 to 150xc2x0 C. particularly 50 to 100xc2x0 C. If necessary, it can be dried at 50 to 200xc2x0 C., preferably 70 to 100xc2x0 C.
Suitable tetrafluoroethylene polymer emulsions are commercially available products, and are sold by the DuPont company as Teflon(copyright) 30 N.
The moulding compositions according to the invention may contain at least one of the customary additives, such as internal lubricants and demoulding agents, nucleating agents, anti-static agents and stabilisers, as well as colorants and pigments.
In addition, the moulding compositions according to the invention may also contain very finely divided inorganic powders in an amount of up to 50 parts by weight, preferably up to 20 parts by weight and particularly from 0.5 to 10 parts by weight.
These very finely divided inorganic compounds consist of one or more metals from main groups 1 to 5 or from subgroups 1 to 8 of the periodic table of the elements, preferably from main groups 2 to 5 and from subgroups 4 to 8, most preferably from main groups 3 to 5 and subgroups 4 to 8, in combination with at least one element selected from the group comprising oxygen, sulphur, boron, phosphorus, carbon, nitrogen, hydrogen and silicon.
Examples of preferred compounds include oxides, hydroxides, hydrated oxides, sulphates, sulphites, sulphides, carbonates, carbides, nitrates, nitrites, nitrides, borates, silicates, phosphates, hydrides, phosphites or phosphonates.
Particular examples of preferred, very finely divided inorganic compounds include TiN, TiO2, SnO2, WC, ZnO, Al2O3, AlO(OH), ZrO2, Sb2O3, SiO2, iron oxides, Na2SO4, BaSO4, vanadium oxides, zinc borate, silicates such as Al silicates, Mg silicates, and one-two- or three-dimensional silicates. Mixtures and doped compounds can also be used. Moreover, the surfaces of these nano-scale particles can be modified with organic molecules in order to improve the compatibility thereof with polymers. Hydrophobic or hydrophilic surfaces can be produced in this manner.
The average particle diameters are less than or equal to 200 nm, preferably less than or equal to 150 nm, particularly 1 to 100 nm.
The expressions xe2x80x9cparticle sizexe2x80x9d and xe2x80x9cparticle diameterxe2x80x9d always denote the average particle diameter d50 as determined by ultracentrifuge measurements as described by W. Scholtan et al., Kolloid-Z. und Z. Polymere 250 (1972), pages 782 to 796.
The inorganic compounds may exist as powders, pastes, sols, dispersions or suspensions. Powders can be obtained by precipitation from dispersions, sols or suspensions.
The powders can be incorporated in the synthetic thermoplastic materials by customary methods, for example by the direct kneading or extrusion of the constituents of the moulding composition and the very finely divided inorganic powders. The preferred methods are the preparation of a master batch, e.g. comprising flame retardant additives, other additives, monomers and solvents in component A, or co-precipitation from dispersions of the graft rubbers together with dispersions, suspensions, pastes or sols of the very finely divided inorganic materials.
The moulding compositions according to the invention may contain up to 35% by weight, with respect to the total moulding composition, of a further flame retardant which optionally has a synergistic effect. Examples of further flame retardants include organic halogen compounds such as decabromobisphenyl ether, tetrabromobisphenol, inorganic halogen compounds such as ammonium bromide, nitrogen compounds such as melamine, melamine-formaldehyde resins, inorganic hydroxide compounds such as Mg or Al hydroxide, inorganic compounds such as antimony oxide, barium metaborate, hydroxoantimonate, zirconium oxide, zirconium hydroxide, molybdenum oxide, ammonium molybdate, zinc borate, ammonium borate, barium metaborate and tin oxide, as well as siloxane compounds.
The moulding compositions according to the invention, which contain components A) to E) and optionally other known additives such as stabilisers, colorants, pigments, internal lubricants, demoulding agents and nucleating agents, as well as anti-static agents, are produced by mixing the respective constituents in the known manner, and by compounding and extruding them in the melt, at temperatures of 200xc2x0 C. to 300xc2x0 C., in customary processing units such as internal kneaders, extruders and twin-shaft endless screw devices, wherein component E) is preferably used in the form of the aforementioned coagulated mixture.
Mixing of the individual constituents can be effected either successively or simultaneously, in the known manner, and either at about 20xc2x0 C. (room temperature) or at elevated temperature.
Due to their excellent flame-resistance, their very good processing properties and their very good mechanical properties, particularly their outstanding rigidity, the thermoplastic moulding compositions according to the invention are suitable for the production of mouldings of any type, particularly those which are subject to the requirement of increased fracture-resistance.
The moulding compositions of the present invention can be used for the production of mouldings of any type. Mouldings can be produced by injection moulding in particular. Examples of mouldings which can be produced include housing parts of any type, e.g. for domestic appliances such as juice presses, coffee machines or mixers, or for office machines, covering panels for the building sector and parts for the motor vehicle sector. These mouldings can also be used in the field of electrical engineering, because they have very good electrical properties.
Another form of processing is the production of mouldings by the swaging of previously produced panels or sheets.
Therefore, the present invention further relates to the use of the moulding compositions according to the invention for the production of mouldings of any type, preferably of the type mentioned above, and also relates to mouldings from the moulding compositions according to the invention.

Flame resistant ABS polycarbonate mouldable materials

Abstract: and 0.05 to 5 parts by weight of a fluorinated polyolefine.