A loading hose for use in a paper machine doctor or coating device, which loading hose is located between the doctor""s or coating device""s blade support and rotatably arranged blade holder, is arranged to load the doctor blade of the doctor or the coating blade of the coating device. The loading hose incorporates a flexible casing, which is pressure-resistant and of a uniform cross-section. The loading hose includes at least one stiffening member attached to the casing and arranged to lie against either the blade support or the blade holder.

This invention relates to a loading hose for use in a paper machine doctor or coating device, which loading hose lies between the doctor""s or coating device""s blade supports and rotatable blade holder. The loading hose is arranged to load the blade of the doctor or the coating blade of the coating device, and has a flexible, pressure-resistant casing of uniform cross-section.
In a hose-loaded doctor in a paper machine, the contact force of the doctor blade on the surface of the roll being cleaned, or, in coating devices, the contact force of the coating blade on the surface being coated, is increased by means of loading hoses acting on the blade holder. Generally, two loading hoses are used in the blade holders in question. The parts of the doctor and the loading hoses are arranged so that one loading hose loads the blade and the other releases it. The return movement loading hose can also be used to create a counter-pressure, allowing a higher and more easily regulated pressure to be used in the loading hose. This is important, because the essential factor in adjustment and loading is the pressure difference, and not the pressure level. The usual pressure medium is air.
Loading hoses normally have an oval cross-section. The loading hose is set between the turning blade holder and its support. Generally, the loading hose is supported by its widest sides against the support surfaces. Over a certain distance, the loading hose operates as desired, in other words, the thickness of the hose increases, while its width remains essentially the same. However, in known loading hoses, this operational distance is short, and, as the distance between the support surfaces increases further, the loading hose assumes an increasingly round shape. In this case, the force created by the loading hose suddenly drops, which is extremely disadvantageous in terms of loading. In addition, known loading hoses are flexible in all directions, so that when the loading varies they move between the blade holder and the support and can even hang partly outside these. This causes variations in the loading force over the length of the doctor. In addition, when the blade returns, the part of the loading hose that is hanging loosely can be squeezed, and even broken, between the parts of the doctor or coating device.
The present invention provides a new type of loading hose for use in the doctor or coating device of a paper machine, which eliminates the defects of the prior art and creates the desired loading profile in the blade.
More specifically, the present invention provides a loading hose for use in a paper machine doctor or coating device, which loading hose is located between the doctor""s or coating device""s blade support and rotatably arranged blade holder. The loading hose is arranged to load the doctor blade of the doctor or the coating blade of the coating device, and incorporates a flexible casing, which is pressure-resistant and of a uniform cross-section. The loading hose includes at least one stiffening member attached to the casing, which is arranged to lie against one of the blade support or the blade holder.
The stiffening member comprises stiffening plates, at least one of which is manufactured from a composition material to create a friction or sliding effect. Alternatively, the stiffening member comprises stiffening plates, on top of one of which a layer is arranged to create a friction or sliding effect. The layer may comprise friction or sliding plates, which are narrower than the stiffening plate or the friction or sliding plates may comprise at least two narrow parts.
In yet another arrangement the layer is a surfacing.
Additional plates may be provided inside the loading hose at the location of the stiffening members, the width of which is essentially the same as that of the stiffening members.
Part of the cross-section of a loading hose according to the invention is rigid, so that it cannot become detrimentally rounded. The hose is also stiff enough longitudinally to ensure that it remains in place, even if contact is lost with the support surfaces. This makes it less probable that the hose will hang loosely and be broken. In addition, there is less variation in the level of force arising from changes in the distance between the moment point and the loading hose. The loading profile of the blade also remains as desired over the entire length of the doctor or coating device while the installation of the loading hose is facilitated. In addition, the friction properties of the loading hose can be altered if required, which also facilitates installation, among other things.
These and other features and advantages of the invention will be more fully understood from the following detailed description of the invention taken together with the accompanying drawings.

Loading hose for use in a paper machine doctor or coating device


A method and apparatus to impart a coating layer on the surface of decorative mouldings that are widely used in the externally insulated finishing systems (EIFS) in the construction industry. The method is a sequence of mechanically advancing a core, constructed from pre-formed expanded polystyrene (EPS, in a straight horizontal plane through a coating chamber/hopper with templates conforming to the desired decorative profile. The apparatus is a rectangular box with a funneled opening at the top with adjustable internal plates to direct the material from the sides of the box toward the pre-formed core that is being coated. Two plates on the bottom of the box support the pre-formed core and are adjustable to leave an opening in the center so that excess material can fall through the bottom after coating the last core. The templates are designed to be interchangeable with other coating apparatus designed by the inventor to produce start strips, decorative mouldings, wall panel sections and columns commonly used in the construction industry.

The externally insulated finishing systems (hereinafter referred to as EIFS) construction basically consists of framing a building and covering the outside surface with a backboard that may be plywood, gypsum or cement board prior to attaching the exterior insulation and finish.
The exterior insulation consists of EPS sheets mechanically or adhesively attached to the backboard. The EPS sheets are then covered with one or two layers of cloth mesh and a base coat of stucco.
The base coat is either sprayed or trowelled on and finished smooth by hand with a float. A finish stucco material is then applied to give the desired decorative surface and colour.
Decorative mouldings are generally preformed and finished and are ready to be installed on the construction site. They are typically comprised of an expanded polystyrene (EPS) core and coated with a plaster or stucco-like material to provide an attractive decorative finished surface. To improve strength and durability, a fibre mesh can be applied to the core prior to coating.
The prevalent method of producing a decorative moulding is to align rows of the cores on plastic topped tables and staple or screw them to the tabletop. There could be as many as four rows of cores places side by side on a four feet wide table, extending up to ninety feet long or more. If required, the cores may have had mesh applied prior to placing them on the table.
The coating material is poured from a pail along the length of the cores and massaged by hand on to the exposed surfaces of the cores. A box, with a steel template cut to a finish profile, is then slid along the length of the table, thus imparting the finished profile on the workpiece. The workpiece is allowed to dry, and another coating can be applied with a finer grained material to impart a smoother finish.
After allowing the workpiece to completely dry, it is pried off the table. The edges that were defined by the tabletop can be sanded and any minor imperfections can be repaired.
This whole process usually takes twenty-four hours and requires clean up after of the tabletops, removal of the screws, cleaning the box and template. This method is very costly, in terms of labour and space.
More recently, various types of automated equipment have been produced to apply the coating. These basically involve pushing the pre-formed core through a coating chamber equipped with sides, bottom and entry and exit dies or templates. So far there has not been any manufacturer to offer a rationalized standard, off the shelf, range of templates or coating chamber/hopper to accommodate such a selection. No manufacturer has been able to provide templates that are adjustable to allow for the inevitable variation of the pre-formed core sizes. For example Canadian patent 2,229,933 published Aug. 19, 1999 discloses a method and apparatus for coating a decorative workpiece. This apparatus drives a core through a coating chamber with a pair of conveyor belts with spikes penetrating the core from the bottom surface. The core is driven through a pressurized coating chamber by the conveyor belts. An elongate channel or dovetail is pre-cut in the bottom of the core that engages on a corresponding rail on the apparatus, and holds the core against lateral and vertical movement as it is coated. While this method and apparatus does provide a coating on the decorative surface of the workpiece, in practise it can be very troublesome. If the cores are not tightly placed end to end with each other as they pass through the coating chamber, the coating material leaks on to the conveyor belts and rail. The leaked material can accumulate as lumps on the belts and impart an uneven finish on the workpiece. Furthermore, as the last core passes through the coating chamber, all the excess material falls onto the rail and spiked belts thus requiring a meticulous cleanup.
Additionally, the apparatus disclosed in Canadian patent 2,229,933 published Aug. 19, 1999 is extremely limited in its application in coating decorative inside corner mouldings. Also, an undesirable channel or dovetail is required on the underside of the core. Furthermore, because the ends of the coating chamber are angled, the templates are not easily produced because of the complicated rendering of the resulting perpendicular section required on the workpiece. Also, no method is disclosed to adjust the coating thickness other than the fixed sizes of the templates.
Canadian patent application 2184205 discloses a method and apparatus for manufacturing decorative mouldings. In this method, the workpiece is driven by conveyor belts abutting both sides of the workpiece before passing through a coating chamber while being slidingly engaged with a continuous flat tabletop. While this apparatus does provide a coating on the decorative surface of the workpiece, it is also troublesome and limited in its application. Firstly, if the cores are not tightly butted up against each other, end to end, the coating material leaks on to the tabletop, accumulates and affects the thickness of the coating. Holding the cores against the tabletop as they pass through the coating chamber creates friction that makes the cores harder to drive through the coating chamber. For inside corner mouldings, the conveyor belts can only drive against two corners on the sides of the core. The belts rip the corners of the core before entering the coating chamber. Slipping can occur which results in an uneven surface finish. Pieces of the core are carried into the coating chamber and contaminate the mix. The dies as illustrated in the patent with tapered openings having sharp inside corners are not easily achieved, except by hand grinding and filing, making them too costly. Additionally, the apparatus does not allow for adjusting the coating thickness other than the fixed sizes of the templates.
Therefore, there is a need to develop a method and apparatus for coating the cored workpieces that includes a coating chamber that accepts a standard range of templates, templates that adjust to allow control of the coating thickness and for size variations of the cores, a way to allow material to escape if the cores are not butted close enough to prevent leakage between subsequent cores as they pass through the coating chamber.

Coating chamber and templates to produce decorative mouldings


A curable composition comprising (A) an organic polymer having a reactive silicon-containing group, and (B) a block copolymer containing in its molecule one soft segment and at least one hard segment having structural units of an aromatic vinyl monomer. The composition has an improved adhesive property to substrates to which conventional curable compositions comprising an organic polymer having a reactive silicon-containing group are hard to adhere, such as mortar, concrete, fluorocarbon resin coats, EPDM rubber sheet, polyvinyl chloride resin sheet and acrylic resin substrate.

The present invention relates to a curable composition useful as sealing material, adhesive, injection material, putty and the like. The curable composition of the present invention exhibits a good adhesive property to substrates such as mortar and concrete, fluorocarbon resin, EPDM rubber, polyvinyl chloride resin and acrylic resin.
Organic polymers having at least one reactive silicon-containing group in the molecule are known to have the property that the reactive silicon-containing groups hydrolyzed by moisture form siloxane bonds so as to form crosslinkages, thus converting into rubbery cured products.
Of these polymers having a reactive silicon-containing group, those having a main chain skeleton substantially composed of polyoxyalkylene polymer or polyisobutylene have been already industrially produced and widely used for many applications such as sealing material, adhesive, injection material, putty, paint and the like.
However, curable compositions comprising the organic polymers having a reactive silicon-containing group have a problem that the adhesive property is low or peeling occurs when applied to portions which are in contact with mortar or concrete. The curable compositions are also known to have a poor adhesive property to substrates such as EPDM rubber sheet and polyvinyl chloride resin sheet which are used as waterproof sheet for roof, fluorocarbon resin-coated steel sheet used as building material or the like, and acrylic resin board.
In order to solve the problem, it is attempted to incorporate the curable compositions with, as an adhesion promoter, epoxy resins, phenol resins, alkyd resins, various silane coupling agents, alkyltitanate compounds, or polyisocyanate compounds. However, s sufficient adhesive property has not been achieved.
It is an object of the present invention to provide a curable composition which comprises an organic polymer having a reactive silicon-containing group and has a good adhesive property to substrates such as mortar, concrete, fluorocarbon resin coat, EPDM rubber sheet, polyvinyl chloride resin sheet and acrylic resin board.
This and other objects of the present invention will become apparent from the description hereinafter.


Disclosed herein is a UV stabilized composition, comprising a polyester resin and a polycarbonate resin; an impact modifier; and an additive composition comprising a hindered amine light stabilizer and another UV absorber. Such compositions find utility in the manufacture of automobile components, for example.

This disclosure relates to polymer blends, and in particular to improved polyester/polycarbonate blends.
There is substantial commercial interest in the use of transparent polyester/polycarbonate blends, especially those containing impact modifiers. Blends of polyester and polycarbonate having impact modifiers are known in the art. U.S. Pat. No. 5,981,661 to Liao et al. is directed to an impact modifier in a polyester and polycarbonate blend, along with a flame retardant and a single benzotriazole UV stabilizer. U.S. Pat. No. 5,411,999 to Gallucci is directed to a polyester-polycarbonate composition, comprising a polyester having epoxy functionality, polycarbonate, a high impact rubbery modifier, and a catalyst quencher. U.S. Pat. No. 6,291,574 to Gallucci is directed to a moldable thermoplastic polyester composition comprising a sound damping amount of a monoalkenyl arene isoprenoid rubber modifier having a high level of 1,2 or 3,4 linkages.
Various rubbery modifiers have been added to polyesters to improve impact, including: U.S. Pat. No. 4,022,748 directed to rubber elastic graft copolymers; U.S. Pat. Nos. 4,034,013 and 4,092,202 directed to multistage polymers having a rubbery interior and a hard outer shell derived from acrylates; U.S. Pat. Nos. 4,090,966 and 4,271,064 directed to selectively hydrogenated monoalkenyl arene-diene block copolymers as polyester modifiers; and U.S. Pat. No. 4,257,937 directed to polyester-polycarbonate blends with polyacrylate resins.
However, it has been found that certain impact modified polyester/polycarbonate blends are prone to discoloration upon exposure to ultraviolet (UV) light. Such discoloration can be particularly acute when acrylonitrile-butadiene-styrene (ABS) impact modifiers are used. Accordingly, there remains a need in the art for impact modified polyester/polycarbonate compositions that are stabilized to the effects of UV light, such that the compositions do not discolor upon exposure to UV light.
A polyester/polycarbonate composition having enhanced stability to UV light exposure comprises a polymer system comprising a blend of a polyester resin and a polycarbonate resin; an impact modifier; and an additive composition comprising a hindered amine light stabilizer and a UV absorber.
In another embodiment, an essentially transparent, UV stabilized composition comprises a polymer system, wherein the polymer system comprises a cycloaliphatic polyester resin and a linear polycarbonate resin; a rubber grafted ABS impact modifier, wherein the ABS impact modifier comprises greater than or equal to about 90 wt % styrene-acrylonitrile copolymer grafted onto polybutadiene; and an additive composition comprising a hindered amine light stabilizer represented by the formula:
wherein G is an alkyl group having from 17 to 21 carbon atoms, and n is on average greater than about 4, and less than about 7; and a UV absorber selected from the group consisting of a different hindered amine light stabilizer, a hydroxyphenyl-triazene, a hydroxyphenyl-pyrimidine, a benzotriazole, or a combination comprising at least one of the foregoing UV absorbers.
It has been unexpectedly found that a UV stabilized polyester/polycarbonate composition containing ABS-type impact modifiers may be achieved by using an additive composition comprising a blend of two or more different UV absorbers, wherein at least one of the UV absorbers is a hindered amine light stabilizer.
Blends of polyesters (PE) and polycarbonates (PC) are the preferred polymer system, especially when transparent or essentially transparent compositions are preferred. Other polymeric components may be present in the polymer system in relatively minor amounts (e.g., less than about 20 weight percent of the combined PE, PC, and additional polymeric component), such other polymeric components including, for example, thermosetting resins such as alkyds, diallyl phthalates, epoxies, melamines, phenolics, polyesters, urethanes, silicones and the like; elastomers such as acrylates, butyls, polyurethanes, polysulfides, neoprenes, nitrites, silicones, styrenes, butadienes and the like; and thermoplastics such as, acetates, acrylics, cellulosics, polyethers, fluorocarbons, polyamides, polycarbonates, polyethylenes, polypropylenes, polyimides, polyphenyleneoxides, polystyrenes, polysulfones, vinyls, and the like.
Suitable polyesters include those derived from aliphatic, cycloaliphatic, or aromatic diols, or mixtures thereof, containing from 2 to about 10 carbon atoms, and at least one cycloaliphatic or aromatic dicarboxylic acid, and may have repeating units of the following general formula (1):
wherein R1 is a C2-C10 aliphatic, cycloaliphatic, or aromatic radical derived from a diol, and R2 is a Cxe2x80x94C aryl or cycloaliphatic radical.
The diol may be a glycol, such as ethylene glycol, propylene glycol, trimethylene glycol, 2-methyl-1,3-propane glycol, hexamethylene glycol, decamethylene glycol, cyclohexane dimethanol, or neopentylene glycol; or a diol such as 1,4-butanediol, hydroquinone, and/or resorcinol.
Examples of aromatic dicarboxylic acids represented by the decarboxylated residue R2 are isophthalic or terephthalic acid, 1,2-di(p-carboxyphenyl)ethane, 4,4xe2x80x2-dicarboxydiphenyl ether, 4,4xe2x80x2 bisbenzoic acid, and mixtures thereof. All of these acids contain at least one aromatic nucleus. Acids containing fused rings can also be present, such as, for example, in 1,4- 1,5- or 2,6-naphthalene dicarboxylic acids. Preferred dicarboxylic acids include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid and mixtures comprising at least one of the foregoing.
Also contemplated herein are the above polyesters with minor amounts, e.g., from about 0.5 to about 30 percent by weight, of units derived from aliphatic acids and/or aliphatic polyols to form copolyesters. The aliphatic polyols include glycols, such as poly (ethylene glycol). Such polyesters can be made following the teachings of, for example, U.S. Pat. Nos. 2,465,319 and 3,047,539.
Other polyesters suitable for use herein include poly(ethylene terephthalate) (xe2x80x9cPETxe2x80x9d), poly(1,4-butylene terephthalate), (xe2x80x9cPBTxe2x80x9d), and poly(propylene terephthalate) (xe2x80x9cPPTxe2x80x9d). For example, PBT resin is obtained by polymerizing a glycol component at least 70 mole %, preferably at least 80 mole %, of which consists of tetramethylene glycol and an acid component at least 70 mole %, preferably at least 80 mole %, of which consists of terephthalic acid, and polyester-forming derivatives therefore. The glycol component may preferably contain not more than about 30 mole %, preferably not more than about 20 mole %, of another glycol, such as ethylene glycol, trimethylene glycol, 2-methyl-1,3-propane glycol, hexamethylene glycol, decamethylene glycol, cyclohexane dimethanol, or neopentylene glycol. The acid component may preferably contain not more than about 30 mole %, preferably not more than about 20 mole %, of another acid such as isophthalic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 4,4xe2x80x2-diphenyl dicarboxylic acid, 4,4xe2x80x2-diphenoxyethane dicarboxylic acid, p-hydroxy benzoic acid, sebacic acid, adipic acid and polyester-forming derivatives thereof.
Block copolyester resin components are also useful, and can be prepared by the transesterification of straight or branched chain poly(1,4-butylene terephthalate) and a copolyester of a linear aliphatic dicarboxylic acid and, optionally, an aromatic dibasic acid such as terephthalic or isophthalic acid with one or more straight or branched chain dihydric aliphatic glycols. For example a poly(1,4-butylene terephthalate) can be mixed with a polyester of adipic acid with ethylene glycol, and the mixture heated at 235xc2x0 C. to melt the ingredients, then heated further under a vacuum until the formation of the block copolyester is complete. As the second component, there can be substituted poly (neopentyl adipate), poly(1,6-hexylene azelate-coisophthalate), poly(1,6-hexylene adipate-co-isophthalate) and the like. An exemplary block copolyester of this type is available commercially under the trade designation VALOX 330 (G.E. Plastics, Pittsfield, Mass.).
Useful herein when high melt strength is important, are branched high melt viscosity poly(1,4-butylene terephthalate) ester resins, which include a small amount of (e.g., up to 5 mole percent based on the terephthalate units) a branching component containing at least three ester forming groups. The branching component can provide branching in the acid unit portion of the polyester, or in the glycol unit portion, or it can be hybrid. Such branching components include, for example, tri- or tetracarboxylic acids (i.e., trimesic acid, pyromellitic acid, and lower alkyl esters thereof, and the like); polyols, preferably, triols and tetrols, (i.e., trimethylolpropane, pentaerythritol, and the like); and/or dihydroxy carboxylic acids and hydroxydicarboxylic acids and derivatives (i.e., dimethyl hydroxyterephthalate, and the like.) Branched poly(1,4-butylene terephthalate) resins and their preparation are described in Borman, U.S. Pat. No. 3,953,404. In addition to terephthalic acid units, small amounts, (e.g., from about 0.5 to about 15 weight percent) of other components may be present. Other components include: aromatic dicarboxylic acids (e.g., isophthalic acid, naphthalene dicarboxylic acid, and the like); aliphatic dicarboxylic acids (e.g., adipic acid, oxalic acid and the like) can also be present. In addition, other components include diol components other than those derived from 1,4-butanediol (i.e., ethylene glycol, cyclohexylenedimethanol, and the like), as well as trifunctional, or higher, branching components, (e.g., pentaerythritol, trimethyl trimesate, and the like). In addition, the poly(1,4-butylene terephthalate) resin component can also include other high molecular weight resins such as poly(ethylene terephthalate), block copolyesters of poly(1,4-butylene terephthalate) and aliphatic/aromatic polyesters, and the like.
The molecular weight of the poly(1,4-butylene terephthalate) should be high enough to provide an intrinsic viscosity of at least 0.6, with an intrinsic viscosity of about 0.8 desired, and an intrinsic viscosity of 0.9 deciliters per gram being more desired. The molecular weight should also be low enough to provide an intrinsic viscosity of less than about 2.0, an intrinsic viscosity of about 1.8 desired, and an intrinsic viscosity of 1.6 deciliters per gram being more desired, all of which being measured, for example, as a solution in a 60:40 mixture of phenol and tetrachloroethane at 30xc2x0 C.
Cycloaliphatic polyesters are the most preferred polyesters, and can be defined in many ways, including the method in which they are prepared. For example, suitable cycloaliphatic polyesters may be prepared by reaction of a diol with a dibasic acid or derivative thereof, provided that at least a portion of the diol and/or the acid is cycloaliphatic. Diols useful in the preparation of suitable polyester resins are straight chain, branched, or cycloaliphatic, with the straight chain or branched alkane diols preferably containing at least 2 carbon atoms, and at most 12 carbon atoms on average. Examples of suitable diols include, but are not limited to, ethylene glycol, propylene glycol (i.e., 1,2- and 1,3-propylene glycol), butane diol, e.g., 1,3- and 1,4-butane diol, diethylene glycol, 2,2-dimethyl-1,3-propane diol, 2-ethyl-2-methyl-1,3-propane diol, 1,3- and 1,5-pentane diol, di-propylene glycol, 2-methyl-15-pentane diol, 1,6-hexane diol, 1,4-cyclohexane dimethanol, triethylene glycol, 1,10-decane diol, mixtures of at least one of the foregoing, and the like. Also, chemical equivalents of diols include esters, such as dialkylesters, diaryl esters, and the like.
Examples of preferred diols include dimethanol-bicyclo-octane, and dimethanol decaline. Most preferred diols are in general cycloaliphatic diols or chemical equivalents thereof, in particular 1,4-cyclohexane dimethanol or a chemical equivalent thereof. In the instance when the preferred cycloaliphatic diol can contain a mixture of cis- and trans-isomers, a cis to trans weight to weight ratio (cis/trans) of at least about 1 to 4 cis/trans, and at most about 4 to 1 cis/trans is preferred, a cis/trans ratio of about 1 to 3 cis/trans being most preferred.
Di-acids (dibasic acids) useful in the preparation of suitable cycloaliphatic polyester resins have at least two carboxyl groups, each of which is attached to a saturated carbon in a saturated ring. A preferred diacid is 1,4-cyclohexanedicarboxylic acid and most preferred is trans-1,4-cyclohexanedicarboxylic acid as further explained above. Other examples of suitable cycloaliphatic acids include decahydro-naphthalene dicarboxylic acid, norbornene dicarboxylic acids, and bicyclo-octane dicarboxylic acids and salts thereof. Linear aliphatic diacids are useful herein provided the polyester has at least one monomer containing a cycloaliphatic ring. Examples of linear aliphatic diacids include, but are not limited to, succinic acid, adipic acid, dimethyl succinic acid, azelaic acid, and the like. Various mixtures of diacid and diols are also suitable for use herein to produce suitable cycloaliphatic polyesters.
Cyclohexanedicarboxylic acids and chemical equivalents thereof can be prepared, for example, by the hydrogenation of cycloaromatic diacids and corresponding derivatives such as isophthalic acid, terephthalic acid of naphthalenic acid in a suitable solvent. This process may also include preparation with water and/or acetic acid at room temperature and atmospheric pressure using suitable catalysts such as rhodium supported on a suitable carrier of carbon or alumina, as disclosed in Friefelder et al., Journal of Organic Chemistry, 31, 34-38 (1966); U.S. Pat. No. 2,675,390 to Roseneblatt, and U.S. Pat. No. 4,754,064 to Lillwitz. Cyclohexanedicarboxylic acids and chemical equivalents thereof may also be prepared by the use of an inert liquid medium using a catalyst of palladium or ruthenium in carbon or silica, wherein an acid is at least partially soluble under reaction conditions, as disclosed in U.S. Pat. No. 2,888,484 to Dekm et al. and U.S. Pat. No. 3,444,237 to Jaffe.
During hydrogenation, two or more isomers of cyclohexane dicarboxylic acids may be obtained, in which the carboxylic acid groups are in both the cis- and trans-positions. The cis- and trans-isomers can be separated by crystallization with or without a solvent, for example, n-heptane, or by distillation. Cis-isomers tend to provides better blending; however, trans-isomers tend to have higher melting and crystallization temperatures, either of which may be preferred depending on the end use. As such, mixtures of the cis- and trans-isomers of cyclohexanedicarboxylic acids are also useful herein. When a mixture of isomers and/or more than one diacid is used, a copolyester or a mixture of two polyesters may also be used as the cycloaliphatic polyester resin.
Chemical equivalents of these diacids include esters, alkyl esters, dialkyl esters, diaryl esters, anhydrides, acid chlorides, acid bromides, and the like. The preferred chemical equivalents comprise the dialkyl esters of the cycloaliphatic diacids. The most preferred chemical equivalent comprises dimethyl esters of the acid, particularly dimethyl-trans-1,4-cyclohexanedicarboxylate.
Dimethyl-1,4-cyclohexanedicarboxylate can be obtained by ring hydrogenation of dimethylterephthalate, wherein two isomers having the carboxylic acid groups in the cis- and trans-positions are obtained. The isomers can be separated, the trans-isomer being especially preferred. Mixtures of the isomers are suitable as explained above and preferably in the ratios as explained above.
A preferred cycloaliphatic polyester is poly-1,4-cyclohexane-dimethanol-1,4-cyclohexanedicarboxylate (hereinafter referred to as PCCD), wherein R1 and R2 is a cyclohexylidene radical, and further wherein R2 is derived from cyclohexanedicarboxylate or a chemical equivalent thereof, and is selected from the cis- or trans-isomer or a mixture of cis- and trans-isomers thereof.
Suitable cycloaliphatic polyester resins can be generally made as described in U.S. Pat. No. 2,465,319 to Whinfield et al. The reaction is generally conducted in the presence of a suitable catalyst such as, for example, tetra(2-ethyl hexyl) titanate, in a suitable amount, typically about 50 to 400 ppm of titanium based upon the final product.
The relative amounts of polyester, polycarbonate, and other optional polymers in the polymer system is generally dictated by the desired properties of the compositions and are readily determined by one of ordinary skill in the art without undue experimentation. For automotive parts, the polymer system generally comprises polyester resin in an upper amount of about 90, preferably about 70, and more preferably about 60 weight percent (wt %) of the total polymer system. The polyester resin is present in amounts greater than about 10, preferably greater than about 20 and more preferably greater than about 30 wt % of the total weight of the polymer system.
Polyester resins may also contain catalyst quenchers (also known as stabilizers) that inhibit activity of any catalysts that may be present in the resins. Catalyst quenchers are described in detail in U.S. Pat. No. 5,441,997 to Walsh et al. Preferably, quenchers provide a transparent and colorless product. Quenchers are used at a concentration of at least about 0.001%, preferably at least about 0.06% by weight of the polymer system and impact modifier. Quenchers are also used at a concentration of at most about 5%, preferably at most about 0.5% by weight of the polymer system and impact modifier.
Preferred quencher/stabilizers include an effective amount of an acidic phosphate salt; an acid, alkyl, aryl or mixed phosphite having at least one acidic hydrogen; a Group IB or Group IIB metal phosphate salt; a phosphorus oxo acid, a metal acid pyrophosphate or a mixture thereof and the like. The suitability of a particular compound for use as a stabilizer may be readily determined without undue experimentation by one of skill in the art.
Useful acidic phosphate salts include sodium dihydrogen phosphate, mono zinc phosphate (MZP), potassium hydrogen phosphate, calcium dihydrogen phosphate and the like. The phosphites may have the formula P(OR3)(OR4)(OR5), wherein R3, R4 and R5 are independently selected from the group consisting of hydrogen, alkyl and aryl with the proviso that at least one of R3, R4, and R5 is hydrogen. The phosphate salts of a Group IB or Group IIB metal of the periodic table include zinc phosphate, copper phosphate, and the like. The phosphorus oxo acids include phosphorous acid, phosphoric acid, polyphosphoric acid or hypophosphorous acid. Suitable polyacid pyrophosphates are of the formula MxHyPnO3n+1, wherein M is a metal, x is from 1 to about 12, y is from 1 to about 12, n is from 2 to about 10, and the sum of x+y is equal to n+2. The preferred M is an alkaline or alkaline earth metal.
Preferred quenchers include oxo acids of phosphorous or acidic organo phosphorus compounds. Inorganic acidic phosphorus compounds may also be used as quenchers, with the most preferred quenchers being phosphoric or phosphorous acid.
Preferably, the composition comprises a polymer system that consists essentially of a blend of cycloaliphatic polyester as described above, and polycarbonate. By this is meant that additional polymers may be present, but preferably not any that would adversely impact the UV stability of the composition. Polycarbonates are discussed below.
Polycarbonates as used herein include homopolycarbonates, copolycarbonates and copolyestercarbonates and mixtures thereof, and includes compositions having structural units of formula (2):
wherein R6 represents aromatic organic radicals and/or aliphatic, alicyclic, or heteroaromatic radicals. Preferably, R6 is an aromatic organic radical and, more preferably, a radical having the formula xe2x88x92A1xe2x88x92Y1xe2x88x92A2xe2x88x92wherein each of A1 and A2 is a monocyclic divalent aryl radical and Y1 is a bridging radical having one or more atoms which separate A1 from A2. In an exemplary embodiment, one atom separates A1 from A2. Illustrative non-limiting examples of radicals of this type include: xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94S (O)xe2x80x94, xe2x80x94S(O2)xe2x80x94, xe2x80x94C(O)xe2x80x94, methylene, cyclohexyl-methylene, 2-[2.2.1]-bicycloheptylidene, ethylidene, isopropylidene, neopentylidene, cyclohexylidene, cyclopentadecylidene, cyclododecylidene, adamantylidene, and the like. The bridging radical Y1 can be a hydrocarbon group, preferably a saturated hydrocarbon group such as, for example, methylene, cyclohexylidene or isopropylidene.
Suitable polycarbonates can be produced by the interfacial reaction of dihydroxy compounds in which only one atom separates A1 and A2. As used herein, the term xe2x80x9cdihydroxy compoundxe2x80x9d includes, for example, bisphenol compounds having generally formula (3):
wherein
Ra and Rb each represent a halogen atom or a monovalent hydrocarbon group and may be the same or different; p and q are each independently integers from 0 to 4;
and Xa represents one of the groups of formulas (4a) and (4b):
wherein Rc and Rd each independently represent a hydrogen atom or a monovalent linear or cyclic hydrocarbon group and Re is a divalent hydrocarbon group.
Some illustrative, non-limiting examples of suitable dihydroxy compounds include the dihydroxy-substituted aromatic hydrocarbons disclosed by name or formula (generic or specific) in U.S. Pat. No. 4,217,438. A nonexclusive list of specific examples of the types of bisphenol compounds represented by formulas 5a and 5b include: 1,1-bis(4-hydroxyphenyl) methane; 1,1-bis(4-hydroxyphenyl) ethane; 2,2-bis(4-hydroxyphenyl) propane (hereinafter xe2x80x9cbisphenol Axe2x80x9d or xe2x80x9cBPAxe2x80x9d); 2,2-bis(4-hydroxyphenyl) butane; 2,2-bis (4-hydroxyphenyl) octane; 1,1-bis(4-hydroxyphenyl) propane; 1,1-bis(4-hydroxyphenyl) n-butane; bis(4-hydroxyphenyl) phenylmethane; 2,2-bis(4-hydroxy-1-methylphenyl) propane; 1,1-bis(4-hydroxy-t-butylphenyl) propane; bis(hydroxyaryl) alkanes such as 2,2-bis(4-hydroxy-3-bromophenyl) propane; 1,1-bis(4-hydroxyphenyl) cyclopentane; and bis(hydroxyaryl) cycloalkanes such as 1,1-bis(4-hydroxyphenyl) cyclohexane.
Two or more different dihydric phenols or a copolymer of a dihydric phenol with a glycol or with a hydroxy (xe2x80x94OH) or acid-terminated polyester may be employed, or with a dibasic acid or hydroxy acid, in the event a carbonate copolymer rather than a homopolymer may be desired for use. Polyarylates and polyester-carbonate resins or their blends can also be employed. Branched polycarbonates are also useful, as well as blends of linear polycarbonate and a branched polycarbonate. The branched polycarbonates may be prepared by adding a branching agent during polymerization.
Suitable branching agents include polyfunctional organic compounds containing at least three functional groups, which may be hydroxyl, carboxyl, carboxylic anhydride, haloformyl and mixtures thereof. Examples include, but are not limited to trimellitic acid, trimellitic anhydride, trimellitic trichloride, tris-p-hydroxy phenyl ethane, isatin-bis-phenol, 1,3,5-tris((p-hydroxyphenyl)isopropyl)benzene, 4(4(1,1-bis(p-hydroxyphenyl)-ethyl, alpha,alpha-dimethyl benzyl)phenol, 4-chloroformyl phthalic anhydride, trimesic acid and benzophenone tetracarboxylic acid. Branching agents may be added at a level greater than about 0.005%. The branching agents may also be added at a level less than about 2.0% by weight of the polymer system and impact modifier. Branching agents and procedures for making branched polycarbonates are described in U.S. Pat. No. 3,635,895 to Kramer, and U.S. Pat. No. 4,001,184 to Scott.
Preferred polycarbonates are based on bisphenol A, in which each of A1 and A2 of formula 3 is p-phenylene and Y1 is isopropylidene. The average molecular weight of the polycarbonate is greater than about 5,000, preferably greater than about 10,000, most preferably greater than about 15,000. In addition, the average molecular weight is less than about 100,000, preferably less than about 65,000, most preferably less than about 45,000 g/mol.
For automotive parts, the polymer system comprises polycarbonate resin in an upper amount of about 90 wt %, with an upper amount of about 70 wt % desired, and an upper amount of about 60 wt % more desired, each based on the total weight of the polymer system. A lower wt % of 10 can be employed, with a lower wt % of about 35 desired, and a lower wt % of about 40 more desired, again based on the total weight of the polymer system.
The polymer system may also include various additives incorporated in the resin blend. Such additives include, for example, dyes, pigments, special effect additives, lubricants, nucleating agents, flame retardants, fillers, reinforcing agents, heat stabilizers, antioxidants, plasticizers, antistatic agents, mold releasing agents, additional resins, blowing agents, and the like. Such additional additives being dependent on the final use of the composition, the use being readily determined by those of skill in the art without undue experimentation.
Examples of flame-retardants include halogenated aromatic flame-retardants (e.g., polybromophenyl ethers, brominated polyepoxide, brominated imides, brominated polycarbonate, poly(haloaryl acrylate), poly(haloaryl methacrylate), or mixtures thereof. Examples of such suitable flame retardants are brominated BPA epoxy resins, brominated polystyrenes such as polydibromostyrene and polytribromostyrene, decabromobiphenyl ethane, tetrabromobiphenyl, brominated alpha, omega-alkylene-bis-phthalimides, e.g. N,Nxe2x80x2-ethylene-bis-tetrabromophthalimide, oligomeric brominated carbonates, especially carbonates derived from tetrabromobisphenol A, which, if desired, are end-capped with phenoxy radicals, or with brominated phenoxy radicals. Other aromatic carbonate flame-retardants are set forth in U.S. Pat. No. 4,636,544 to Hepp. The flame-retardants may also be used with a synergist, particularly inorganic antimony compounds. Inorganic synergist compounds include Sb2O5, SbS3, and the like. Especially preferred is antimony trioxide (Sb2O3).
Examples of fillers or reinforcing agents include glass flakes, glass fibers, asbestos, carbon fibers, silica, talc and calcium carbonate. Examples of heat stabilizers include triphenyl phosphite, tris-(2,6-dimethylphenyl)phosphite, tris-(mixed mono-and di-nonylphenyl)phosphite, dimethylbenzene phosphonate and trimethyl phosphate. Examples of antioxidants include octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, and pentaerythrityl-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate]. Examples of plasticizers include dioctyl-4,5-epoxy-hexahydrophthalate, tris-(octoxycarbonylethyl)isocyanurate, tristearin and epoxidized soybean oil. Examples of antistatic agents include glycerol monostearate, sodium stearyl sulfonate, and sodium dodecylbenzenesulfonate. Examples of mold releasing agents include stearyl stearate, beeswax, montan wax and paraffin wax. Examples of other resins include but are not limited to polypropylene, polystyrene, polymethyl methacrylate, and polyphenylene oxide. Individual, as well as combinations of the foregoing may be used. Such additives may be incorporated at a suitable time, in a suitable manner, and at a suitable concentration during the formation of the composition.
When present, the composition may comprise various additives in an upper amount of about 40 wt %, with an upper amount of about 30 wt % desired, and an upper amount of about 5 wt % more desired, based on the total composition. When an essentially transparent composition is desired, the composition may comprise various additives having a total upper amount of about 15 wt %, with an upper amount of about 10 wt % desired, and an upper amount of about 5 wt % more desired. As used herein, essentially transparent is defined as a material having at least 70, preferably 80, and most preferably 90% transmission of visible light. The selection of particular additives and an effective concentration thereof depends on the final use of the composition, and is readily determined by one of skill in the art without undue experimentation.
The composition further comprises an impact modifier. Impact modifiers, as used herein, include materials effective to improve the impact properties of the composition, for example the ductility and/or the notched Izod impact strength of the composition. The present impact modified compositions preferably have a notched Izod impact strength of at least about 40 kJ/m2 at xe2x88x9220xc2x0 C.
Useful impact modifiers are substantially amorphous copolymer resins, including but not limited to acrylic rubbers, ASA rubbers, diene rubbers, organosiloxane rubbers, EPDM rubbers, SBS or SEBS rubbers, ABS rubbers, MBS rubbers and glycidyl ester impact modifiers.
Acrylic rubbers are multi-stage, core-shell, interpolymer compositions having a cross-linked or partially cross linked (meth)acrylate rubbery core phase, preferably butyl acrylate. Associated with this cross-linked acrylic ester core is an outer shell of an acrylic or styrenic resin, preferably methyl methacrylate or styrene, which interpenetrates the rubbery core phase. Incorporation of small amounts of other monomers such as acrylonitrile or (meth)acrylonitrile within the resin shell also provides suitable impact modifiers. The interpenetrating network is provided when the monomers forming the resin phase are polymerized and cross-linked in the presence of the previously polymerized and cross-linked (meth)acrylate rubbery phase.
Particularly suitable are the so-called block copolymers and rubbery impact modifiers, for example, Axe2x80x94Bxe2x80x94A triblock copolymers and Axe2x80x94B diblock copolymers. The Axe2x80x94B and Axe2x80x94Bxe2x80x94A type block copolymer rubber additives which may be used as impact modifiers include thermoplastic rubbers comprised of one or two alkenyl aromatic blocks which are typically styrene blocks and a rubber block, e.g., a butadiene block which may be partially hydrogenated. Mixtures of these triblock copolymers and diblock copolymers are especially useful.
Suitable Axe2x80x94B and Axe2x80x94Bxe2x80x94A type block copolymers are disclosed in, for example, U.S. Pat. Nos. 3,078,254, 3,402,159, 3,297,793, 3,265,765, and 3,594,452 and U.K. Patent 1,264,741. Examples of typical species of Axe2x80x94B and Axe2x80x94Bxe2x80x94A block copolymers include polystyrene-polybutadiene (SBR), polystyrene-poly(ethylene-propylene), polystyrene-polyisoprene, poly(xcex1-methylstyrene)-polybutadiene, polystyrene-polybutadiene-polystyrene (SBR), polystyrene-poly(ethylene-propylene)-polystyrene, polystyrene-polyisoprene-polystyrene and poly(xcex1-methylstyrene)-polybutadiene-poly(xcex1-methylstyrene), as well as the selectively hydrogenated versions thereof, and the like. Mixtures comprising at least one of the aforementioned block copolymers are also useful. Such Axe2x80x94B and Axe2x80x94Bxe2x80x94A block copolymers are available commercially from a number of sources, including Phillips Petroleum under the trademark SOLPRENE, Shell Chemical Co., under the trademark KRATON, Dexco under the trade name VECTOR, and Kuraray under the trademark SEPTON.
Other preferred rubbers useful herein as impact modifiers include graft and/or core shell structures having a rubbery component with a Tg (glass transition temperature) below 0xc2x0 C., preferably between about xe2x88x9240xc2x0 to about xe2x88x9280xc2x0 C., which comprise poly-alkylacrylates or polyolefins grafted with poly(methyl)methacrylate or styrene-acrylonitrile copolymer. Preferably the rubber content is at least about 40 wt %, most preferably, at least about 60%, with between about 60-90 wt %.
Especially suitable rubbers for use as impact modifiers herein are the butadiene core-shell polymers of the type available from Rohm and Haas under the trade name PARALOID(copyright) EXL2600. Most preferably, the impact modifier will comprise a two stage polymer having a butadiene based rubbery core, and a second stage polymerized from methylmethacrylate alone or in combination with styrene. Impact modifiers of the type also include those that comprise acrylonitrile and styrene grafted onto cross-linked butadiene polymer, which are disclosed in U.S. Pat. No. 4,292,233 herein incorporated by reference.
Other impact modifiers useful herein include those which comprise polyphenylene ether, a polyamide or a combination of polyphenylene ether and a polyamide. The composition may also comprise a vinyl aromatic-vinyl cyanide copolymer. Suitable vinyl cyanide compounds include acrylonitrile and substituted vinyl cyanides such a methacrylonitrile. Preferably the impact modifier comprises styrene-acrylonitrile copolymer (hereinafter SAN). The preferred SAN composition comprises at least 10, preferably 25 to 28, percent by weight acrylonitrile (AN) with the remainder styrene, para-methyl styrene, or alpha methyl styrene. Another example of SANs useful herein include those modified by grafting SAN to a rubbery substrate such as, for example, 1,4-polybutadiene, to produce a rubber graft polymeric impact modifier. High rubber content (greater than 50 wt %) resin of this type (HRG-ABS) may be especially useful for impact modification of polyester resins and their polycarbonate blends.
Preferred impact modifiers, referred to as high rubber graft ABS modifiers, comprise greater than or equal to about 90 wt % SAN grafted onto polybutadiene, the remainder being free SAN. Preferred compositions include: about 8% acrylonitrile, 43% butadiene and 49% styrene, and about 7% acrylonitrile, 50% butadiene and 43% styrene, by weight. These materials are commercially available under the trade names BLENDEX 336 and BLENDEX 415 respectively (G.E. Plastics, Pittsfield, Mass.).
Other suitable impact modifiers may be mixtures comprising core shell impact modifiers made via emulsion polymerization using alkyl acrylate, styrene and butadiene. These include, for example, methymethacrylate-butadiene-styrene (MBS) and methymethacrylate-butylacrylate core shell rubbers.
A useful minimum concentration of impact modifier is about 3 weight percent (wt %), with about 5 wt % desired, and about 8 wt % more desired, based on the total weight5 of the polymer system and the impact modifier. An upper concentration of of about 50 wt % can be employed, with about 15 wt % desired, and about 10 wt % more desired, wherein the weight percentages are based on the total weight of the polymer system and the impact modifier.
The UV stabilized composition further includes an additive composition that comprises a combination of a hindered amine light stabilizer and another UV absorber. Useful hindered amine light stabilizers (hereinafter HALS) include substituted piperidine moieties and oligomers thereof, as disclosed in U.S. Pat. No. 4,895,901 to Ramey et al., U.S. Pat. No. 4,210,612 to Karrer, and U.S. Pat. No. 5,015,682 to Galbo. The preferred HALS include 4-piperidinol derivatives having the general formula (5):
wherein
X is oxygen, and Y2 is preferably hydrogen, or hydroxyalkyl, aminoalkyl, or alkyl substituted by both hydroxyl and amino groups, where the alkyl has up to about 20 carbon atoms on average, but may also represent a moiety compatible with the light stabilizing properties of the remainder of the molecule and that furnishes the requisite reactive group.
R7 and R12 are each independently selected from the group consisting of a hydrogen atom, an alkyl group, an alkenyl group, or an arylalkyl group. Preferably, R7 and R12 are each hydrogen. R8, R9, R10, and R11 are each independently selected from the group consisting of an alkyl group having 1 to about 6 carbon atoms, phenyl, an arylalkyl group, an aromatic heterocyclic group having 5 or 6 carbon atoms, and containing an oxygen, sulphur, hydrogen, or nitrogen atom, or R8, R9, R10, and R11 respectively, together or with the carbon atom to which they are attached may represent a C to C cycloalkyl group. Preferably, R8, R9, R10, and R11 are methyl.
Z represents hydrogen, an acyl group, an oxy radical, an alkyl group, an alkenyl group, an alkoxyalkyl group, an arylalkyl group that is unsubstituted or which has one or more substituents in its aryl moiety, including, for example, 2,3-epoxypropyl. Z is preferably represented by the formula xe2x80x94CH2COOR13, wherein R13 represents an alkyl group, an alkenyl group, a phenyl group, an arylalkyl group or a cyclohexyl group. Most preferably, Z is represented by the formula xe2x80x94CH2CH(R14)OR15, wherein R14 represents a hydrogen atom, a methyl group or a phenyl group and R15 represents a hydrogen atom, an alkyl group, an ester, a carbonyl, an acyl group, an aliphatic acyl group, or a group represented by the formula xe2x80x94COOR16, or xe2x80x94OOCR16, wherein R16 represents an alkyl group, a benzyl group, a phenyl group, and the like.
One preferred oligomeric HALS is represented by formula (6):
wherein n is on average greater than about 9, and less than about 12 (i.e., having a molecular weight from about 3100 to about 4000). This material is commercially available under the trade name TINUVIN 622 (CAS Number 065447-77-0, Ciba Specialty Chemicals, Inc., Basel Switzerland).
Another preferred oligomeric HALS is represented by the general formula (7):
wherein G is a C17-C21 alkyl group and n is on average greater than about 4 and less than about 7 (i.e., having a molecular weight from about 3000 to about 4000). One example of this type of HALS wherein n is on average greater than about 4 and less than about 7 is commercially available under the trade name UVINUL 5050H from BASF.
Another preferred HALS is represented by formula (8):
This HALS is commercially available under the trade name SANDUVOR 3058 from Clariant.
The HALS is present in the composition at a concentration greater than about 0.01%, preferably greater than about 0.05%, most preferably greater than about 0.08% by weight based on the total weight of the composition. The HALS is also present in the composition at a concentration less than about 10%, preferably less than about 1%, most preferably less than about 0.6% by weight based on the total weight of the composition.
In addition to the HALS, the UV additive composition also comprises another UV absorber that is different from the particular HALS selected above. This second UV absorber includes, for example, a second HALS, a benzotriazole UV absorbers, and/or a hydroxyphenyl-triazine or -pyrimidine UV absorber. Suitable benzotriazole UV absorbers include the compound represented by formula (9):
This benzotriazole UV absorber is commercially available under the trade name Tinuvin 234 from Ciba.
Another preferred benzotriazole UV absorber is represented by the formula (10):
This benzotriazole UV absorber is commercially available under the trade name Cyasorb UV-5411 from Cytec.
Suitable hydroxyphenyl-triazine or pyrimidine UV absorbers include compounds having a 2,4,6-trisaryl-1,3,5-triazine or 2,4,6-trisaryl-1,3-pyrimidine group, and which further contain free hydroxyl groups. Such compounds are described, for example, in U.S. Pat. No. 3,118,887 to Johns et al., U.S. Pat. No. 3,244,708 to Duennenberger et al., U.S. Pat. No. 3,423,360 to Huber et al., WO 86/3528, U.S. Pat. No. 4,831,068 to Reinert et al., EP-A-434 608,EP-A-458 741, EP-A-483 488, U.S. Pat. No. 5,298,067 to Valet, U.S. Pat. No. 3,442,898 to Luethi et al., and U.S. Pat. No. 4,895,981 to Reinert et al.
The preferred hydroxyphenyl pyrimidine and triazine UV absorbers comprise a pyrimidines or triazines having two phenyl groups, and a resorcinol or substituted resorcinol group attached to the triazine or pyrimidine ring, as disclosed in U.S. Pat. No. 6,239,276 B1 to Gupta et al. and U.S. Pat. No. 5,597,854 to Birbaum et al. Suitable hydroxyphenyl-triazine UV absorbers are generally represented by formula (11):
wherein A is N or CH; and, R17, R18, R19, R20, R21, R22, R23, and R24 are each independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, halogen, haloalkyl, alkoxy, alkylene, aryl, alkyl-aryl, or a combination thereof. Preferably, the hydroxyphenyl-triazine UV absorber is represented by formula (12):
This material is commercially available under the trade name TINUVIN 1577 (CAS Number 147315-50-2, Ciba Specialty Chemicals, Inc., Basel Switzerland). Another example of a preferred hydroxyphenyl-triazine UV absorber is represented by formula (13):
This material is commercially available under the trade name CYASORB UV-1164, from Cytec Industries.
The additional UV absorbers as discussed above are present in the composition at a concentration greater than about 0.01%, preferably greater than about 0.1%, most preferably greater than about 0.2% by weight, based on the total weight of the composition. The additional UV absorbers are furthermore present in the composition at a concentration less than about 10%, preferably less than about 3%, most preferably less than about 0.5% by weight, based on the total weight of the composition.
The composition may be formed by techniques known in the art. The ingredients are typically in powder or granular form, and extruded as a blend, and/or comminuting into pellets or other suitable shapes. The ingredients may be combined in any manner, e.g., by dry mixing or by mixing in the melted state in an extruder, or in other mixers. For example, one embodiment comprises melt blending the ingredients in powder or granular form, extruding the blend and comminuting into pellets or other suitable shapes. Also included is dry mixing the ingredients, followed by mixing in the melted state in an extruder.
The method of processing the present compositions into films can be carried out by conventional film extrusion techniques, for example, by melting the different materials of the different layers in separate extruders and conveying those materials to a die where these different materials are combined into a film. Also included are blow molding and injection molding of the composition. The compositions disclosed herein are thus produced in a manner readily determined by one of skill in the art without undue experimentation.
The compositions described herein unexpectedly provide an enhanced UV stability. The above-described compositions accordingly have a change color (expressed in dE) of less than about 3, preferably less than about 2, and most preferably less than about 1.7 after 810 hours of indoor weathering according to Protocol PV1303.
These UV stabilized compositions described herein are suitable for a wide variety of uses, for example in interior automotive applications including: components, decorative parts or trim pieces of dashboards, elements of sun visors or rear view mirrors, decorative or structural parts of auto interior components; in decorative, structural parts or trim pieces of recreational vehicles including golf carts, boats, jet skies, bicycles, body panels, cladding, and mirror housings; and in applications for building and construction, including, for example, outdoor signs, ornaments, and exterior siding for buildings.
The disclosure is further illustrated by the following non-limiting examples.

UV stabilized, impact modified polyester/polycarbonate blends, articles, and methods of manufacture thereof


A method for detecting and calculating the contribution by external jammer signals to the total power received by a reverse link of a communication system. The total received power for a reverse link is measured. Calculations of load estimates based on power rise due to background noise and total Eb/N0 are performed. The contribution of external jammer signals to the total power received is calculated from the load estimates. The ability to calculate the power level of external jammer signals for a certain reverse link allows a service provider to more efficiently use the capacity of the reverse link. An average of the calculated external jammer power level can be calculated over a period of time defined by the service provider of the communication system.

1. Field of the Invention
The present invention is generally related to a method for detecting and calculating the contribution of external jammer signals to total power received in a reverse link of a communication system.
2. Description of the Related Art
Communication systems, and in particular, wireless communication systems comprise a plurality of communication channels through which subscribers of such systems communicate with each other and with the system. Wireless communication systems such as Code Division Multiple Access (CDMA) systems and other communication systems have a certain capacity; that is they are limited by the amount of communication channels that can be made available to subscribers of such systems. The capacity of a communication system is the amount of total information per unit time (i.e., information rate, RT) that can be conveyed (within the system) while maintaining an acceptable quality of communications. The acceptable quality of communications is typically defined by the operator (or service provider) of the communication system. Usually, the capacity is directly related to the number of subscribers using the system; the more subscribers using the system the higher the information rate.
Referring to FIG. 1 there is shown part of a typical topography of a cellular CDMA wireless communication system. The communication system depicted in FIG. 1 comprises a plurality of cells each of which delineates a particular geographical area or terrain that is covered by the communication system. The cells have borders which form hexagons. The hexagons (108, 114, 110, 112) symbolically represent areas of coverage within which subscribers located in the same cell communicate with the cell (i.e., cell system equipment). Each cell has system equipment (owned and controlled by a system operator or service provider) that are used by the system to admit subscribers to the system; that is to allow subscribers of the system to gain access to the communication system for communicating with each other and/or with the system. At least part of the system equipment is typically located at a base station (e.g., 100, 102, 104, 106). Some of the system equipment at the base stations are Radio Frequency (RF) transmitters and receivers for conveying (i.e., transmitting and receiving) communication signals.
Other system equipment, which can also be located at a base station, provide the Operations, Administration and Maintenance (OAandM) services typically associated with communications equipment. For example, subscriber billing, allocating communication channels for subscribers, and giving subscribers access to the communication system are some of the services provided by the OAandM equipment. Subscribers given access to the communication system can communicate with other subscribers via the cell""s base station.
For a CDMA communication system, such as the one depicted in FIG. 1, a subscriber gains access by making a request to system equipment (usually located at a base station). For example, subscriber 124 in cell 112 makes a request to base station 100 to have access to the communication system. System equipment at base station 100 receive the request and decide whether to give subscriber 124 access to the communication system. Subscriber 124 and base station 100 (as well as other base stations and subscribers) communicate via communication channels called forward links and reverse links. A forward link is a communication channel through which base station 100 transmits communication signals to subscriber 124. A reverse link is a communication channel through which subscriber 124 transmits communication signals to base station 100. Thus, each subscriber has a forward link and a reverse link that it uses to communicate with system equipment and/or with other subscribers of the communication system.
Typically, the system decides to provide access to a subscriber by performing a power level analysis that attempts to maintain the quality of communications between subscribers at an acceptable level as defined by the system operator. The system could continue to admit subscribers requesting communication services (or continue to respond to a system request or xe2x80x9cpagexe2x80x9d to admit subscribers) and thus continue to increase its information rate. At some point an overload condition will occur causing the quality of communications provided by the communication system to be degraded. An overload condition occurs when the information rate of the communication system causes the quality of communications (e.g., existing voice and/or data calls) to drop below an acceptable level set by the system operator. Usually the acceptable level is set as a threshold below the system""s ultimate capacity. One example of an overload condition is when a cell communicates with a relatively large number of subscribers such that the system cannot meet the desired signal to noise ratio (SNR) requirement. The number of subscribers that can be adequately serviced by a cell depends on the SNR usually expressed in terms of a ratio,             E      b              N      0        ,
where Eb represents the total received signal energy per unit of information (e.g., energy per bit) and N0 represents the total noise power density. The higher the       E    b        N    0
of the signal measured at a receiver, the better the quality of communications.
The following equation defines the reverse-link signal to noise ratio       (                  E        b                    N        0              )        i    ,    k    m
for subscriber i in cell k as measured by cell m:                                           (                                          E                b                                            N                0                                      )                                i            ,            k                    m                ≡                                                            (                                  W                  R                                )                                            i                ,                k                                      xc3x97                          S                              i                ,                k                            m                                                          N              th                        +            J            +                                          ∑                                                      j                    =                    1                                                        j                    ≠                    i                                                                    M                  k                                                                                υ                                      j                    ,                    k                                                                                S                                      j                    ,                    k                                    m                                                      +                                          ∑                                                      l                    =                    1                                                        l                    ≠                    k                                                  L                                                                            ∑                                      j                    =                    1                                                        M                    l                                                                                υ                                          j                      ,                      l                                                                                S                                          j                      ,                      l                                        m                                                                                (        1        )
The indices i and j designate particular subscribers and the indices k, l and m designate particular cells. Ml is the number of subscribers in cell l, Mk is the number of subscribers in cell k, L is the total number of cells in the system,       (          W      R        )        i    ,    k
is called the processing gain for subscriber i in cell k where W is the bandwidth or a CDMA carrier signal and R is the information rate of subscriber i. The average power of the reverse-link signal is defined as the product of the power level (S) and the voice activity factor (xcexd) of the reverse-link signal. In equation (1) above, Sj,km is the power level of the communication signal of subscriber j in cell k as measured at cell m, and the voice activity xcexdj,k represents how often subscriber j in cell k speaks during a telephone conversation or how often a data energy burst is transmitted by the subscriber. Nth represents the power level of thermal noise typically generated by electrical and electronic circuitry. J represents the power level of any external jammer signals, which is a type of interference. Any signal other than a subscriber""s communication signal is called interference. Two major sources of interference are thermal noise and external jammer signals. An external jammer signal is any signal not generated by the communication system, but is received by the communication system or received by a subscriber of the communication system. For example, an external jammer interfering with a CDMA communication system is an analog mobile telephone user transmitting signals whose frequency spectrum is partially or entirely the same as the spectral band of the CDMA system; in such a situation the analog mobile signal interferes with CDMA subscriber signals because the subscriber or the communication system or both receive the analog mobile signal.
The aggregate power received by a base station is due to thermal noise (Nth), external jammers (J), and the CDMA subscriber signals (xcexdS). Thus, the total received power through a particular reverse link of a base station, which is called the received signal strength indicator (RSSI), has three components and is represented for a particular cell m by the following equation:                               RSSI          m                ≡                              N            th                    +          J          +                                    ∑                              l                =                1                            L                                                                  ∑                                  j                  =                  1                                                  M                  l                                                                                υ                                      j                    ,                    l                                                                                S                                      j                    ,                    l                                    m                                                                                (        2        )
where the last term on the right-hand side of equation (2) represents the power of CDMA subscriber signals. Note that the RSSI increases when the number of subscribers increases, when the power due to jammer signals increases, and/or even when the thermal noise power increases.
A common and current practice in controlling system overload for a reverse link is to measure the increase in RSSI and decide, based on the RSSI rise, whether to admit to the communication system any additional subscribers who are requesting service. Typically, an RSSI based method is used where the measured RSSI is compared to a threshold and when this measured RSSI is substantially equal to or above the threshold, the system blocks additional access requests from subscribers. Such an RSSI based method assumes that a rise in RSSI is mainly due to the subscribers of the system. Consequently, when the RSSI reaches a system operator defined threshold, no additional subscribers are admitted to the system. The flaw in the RSSI based method is that when a rise in RSSI occurs and such a rise is due to external jammers, the RSSI based method cannot attribute the rise in received power to specifically J or to any particular one of the two other components (i.e., Nth, "ugr"S) of RSSI. In other words, the measured RSSI is an aggregate number and the particular contributions to the RSSI from J cannot be measured directly.
Even though the external jammer signals have virtually no direct effect on a system""s capacity, they will affect the coverage of the communication system such as, for example, the coverage of a base station. The external jammer signal power level can be so high that many of the subscribers are not able to communicate with the system equipment because of interference; the only subscribers who are able to communicate with the system are those subscribers who are located relatively close to the base station and can transmit to the base station at a power level high enough to overcome interference. Interference due to external jammers thus directly affects the coverage (of a cell or a communication system) more so than its capacity. The coverage is the area within which communications can occur between a subscriber and system equipment (e.g., a base station). The higher the jammer power J, the smaller the coverage. Note, however, that if the coverage becomes so small that the cell cannot accommodate any subscribers, it will eventually result in a total loss of its capacity.
Both the reduced coverage and capacity loss would cause higher call blocking rate and/or call dropping rate. The call blocking rate refers to the rate at which subscribers requesting access to the communication system are denied access. The call dropping rate refers to the rate at which subscribers who have obtained access to the communication system are removed from the communication system. When a cell exhibits an increased call blocking rate or an increased call dropping rate or both, the service provider needs to have a capability of distinguishing its causes because the measures to be taken to correct the problem (or to improve the call blocking rate/dropping rate) depends on the particular cause of the problem. If the problem is due to the reduced capacity resulting from an increased subscriber loading in the cell, the system operator may choose to lower the threshold for overload control to admit more subscribers into the system at the expense of the quality, or it may choose to deploy more cells and cell equipment to off-load the excessive cell load to its neighbor cells. If the problem is due to the reduced coverage resulting from the presence of external jammers, the system operator would want to locate the source of the jamming power and then remove the jammers to restore proper coverage.
What is therefore needed is a method of determining the contribution of external jammer signals to the measured RSSI so as to better and more efficiently use the capacity of the communication system and, more particularly, use more efficiently the capacity of the reverse links of the communication system.
The present invention provides a method for detecting and calculating the external jammer signal power received by system equipment in a reverse link of a communication system. The total power received through a reverse link (i.e., RSSI) and the thermal noise power level (i.e., Nth) are measured, and the Eb/N0 and the voice activities for the reverse link are also measured in well known manners. Load estimates based on the RSSI and the Eb/N0 are calculated; that is, an RSSI based load estimate U and an Eb/N0 based load estimate X are calculated. The external jammer signal power is found to be directly related to the product of the total received power and the difference between the two load estimates. The load estimates are estimates of the cell capacity usage due to subscribers currently using the system. Estimate X is based on the ratio of the total power to background noise where background noise is defined as Nth+J. Estimate U is based on the ratio of the total power to thermal noise, Nth. The external jammer signal power J is therefore RSSIxc3x97(Xxe2x88x92U). Thus, a communication system can more efficiently use the capacity of its reverse links because it can calculate the power from external jammer signals and thus determine whether a rise in RSSI is due to external jammer signals.
In particular, the method of the present invention provides the following steps: first, the total received power(RSSIm) for a reverse link of a cell m and the thermal noise for the system equipment of the cell are measured; the Eb/N0 and the voice activity factor for all users in cell m and its neighbor cells are also measured; second, an RSSI based load estimate for cell m, Um, is calculated from the measured RSSI and Nth and an Eb/N0 based load estimate Xm, for cell m, is also calculated; third, an instantaneous jammer power J is thus calculated from RSSIm, Um and Xm where J=RSSImxc3x97(Xmxe2x88x92Um). An average jammer power can be calculated by taking the average of instantaneous jammer power levels over a defined time period.

Method of detecting and calculating external jammer signal power in communication systems


A digital multimedia terminal comprises a receiving unit to receive a broadcasting signal. The digital multimedia terminal also comprises an input unit adapted to receive input associated with a user preferred program characteristic. The digital multimedia terminal also comprises a controller, operatively coupled to the receiving unit and the input unit, adapted to extract program information from received broadcasting signals and to search extracted program information based on the user preferred program characteristic. The digital multimedia terminal may further comprise a display unit, operatively coupled to the controller, adapted to display program description information associated with the extracted program information that corresponds to a broadcast program having the user preferred program characteristic.

A mobile station may support multimedia broadcasting, such as digital multimedia broadcasting (DMB), digital video broadcasting (DVB-H), and media-forward link only (MEDIA-FLO). The DMB is a broadcasting service for providing digital multimedia signals, such as voice data and image data of high quality, to a personal digital assistant (PDA), a vehicle, or a mobile station having a DMB receiver. The DMB may be of a terrestrial DMB (TDMB) type or a satellite DMB (SDMB) type, based on how the signal waves are transmitted. In satellite DMB, a terrestrial repeater station receives digital broadcasting data transmitted from a satellite and transmits the data to a satellite digital multimedia terminal.
The TDMB is a mobile multimedia broadcasting technology capable of providing voice and image services of high quality. The TDMB transfers various contents such as music, text messages, and videos using portable terminals. Furthermore, the TDMB has a complementary relationship with digital terrestrial TV broadcasting technology.
The SDMB provides multimedia broadcasting services including audio, supplementary data, or videos to fixed and mobile receivers via satellite transmissions. The SDMB enables provision of audio broadcasting services of various qualities at low cost, and significantly increases the audible range of conventional broadcasting by providing a wider coverage area through use of satellite communications. The SDMB is being developed as a service to provide convergence between communications and broadcasting. Thus, a user may view the broadcasting of a desired channel using the digital multimedia terminal.
However, to view a desired program, the user must view or confirm the broadcasting program by selecting the channels one by one, or must search for the desired program using an Electronic Program Guide (EPG).

Program searching in digital multimedia terminal


This invention concerns a process of forming a polarizable layer in a buried oxide layer of a silicon-on-insulator substrate for the fabrication of non-volatile memory. This process comprises implanting, through the active silicon layer, Si ions into the buried oxide layer at an ion implantation energy selected so that the implanted ion has its peak concentration between 5-50 nm from the silicon/buried oxide interface. The implantation step can occur while externally heating the silicon-on-insulator substrate at a temperature between 25-300 degrees Celsius. After implantation, an annealing step may be completed to repair any damage the implantation may have created in the silicon-on-insulator substrate.

1. Field of the Invention
The present invention relates generally to silicon-on-insulator structures, and more specifically to processing a polarizable layer in the buried oxide of silicon-on-insulator substrates for the fabrication of non-volatile memory.
2. Discussion of the Background
There are various types of commercial non-volatile memory that have been fabricated on bulk silicon, but no commercial non-volatile memories have been fabricated on SOI substrates that utilize a polarizable layer in the buried oxide in their operation.
Two known techniques for forming the buried oxide layer in SOI substrates are the implantation of oxygen ions in the separation-by-implantation-of-oxygen process (SIMOX) and the method of first growing a thermal oxide and then bonding. The difficulty is that the buried oxide formed using either of these commercial processes are non-polarizable.
The test for the polarizability of the buried oxide is (1) the fabrication of point-contact transistors, (2) measurement of the transistor characteristics, (3) application of a positive poling voltage to the back-gate or drain above the operating voltage and (4) remeasurement of the transistor characteristics. The procedure is then repeated, where a negative poling voltage of the same magnitude is applied to the back-gate or drain. Any significant reproducible hysteresis in the transistor characteristics indicates that the buried oxide has been polarized. These measurements were performed on a wide range of commercially available SOI substrates, and demonstrate that the buried oxides of these substrates are non-polarizable.
In the SIMOX process, a thin layer of a monocrystalline silicon substrate is separated from the bulk of the substrate by implanting oxygen ions into the substrate to form a buried dielectric layer. The SIMOX process provides a heterostructure in which a buried silicon dioxide layer serves as a highly effective insulator for surface layer electronic devices.
In the SIMOX process, oxygen ions are implanted into silicon, after which the material is annealed to form the buried silicon dioxide layer or BOX region. The annealing phase redistributes the oxygen ions such that the silicon/silicon dioxide boundaries become smoother and more abrupt, thus forming a sharp and well-defined BOX region.
One important criterion for SIMOX wafers is the defect density, which should be minimized in order to produce high quality wafers. Defect density can be defined in terms of the departure from perfect crystallinity in the silicon layer that is separated from the bulk substrate by the buried oxide layer. In general, as the oxygen ions are implanted into the wafer to produce the buried SiO2 layer, atomic silicon is displaced. Additionally, excess silicon atoms from the growing BOX region can alter the crystal structure of the top silicon layer resulting in a variety of point and extended defects, such as threading dislocations and stacking faults, during the ion implantation and/or annealing processes. These defects degrade the quality and reliability of devices. e.g., transistors, that are subsequently formed in the upper silicon layer.
It is known that, in the SIMOX substrate, structure and quality of the buried oxide layer formed under the top silicon layer by implanting the oxygen ions into the single-crystal silicon substrate depend on an ion implanting quantity (dose of ions), so that the dose of oxygen ions as 1017-1018/cm2 is required in order to form the buried oxide layer having the abrupt interface. But, there is the disadvantage of producing crystal defects in the top single-crystal silicon layer when the dose of ions is increased, and observing the relation of a crystal dislocation density and the dose of ions, when the dose of ions reaches over 1.0xc3x971018/cm2, the dislocation density is increased and crystal quality of the top silicon layer where device elements are formed is inferior. When the dose of ions is controlled within the range between 0.5xc3x971018/cm2 and less than 1.0xc3x971018/cm2 in order not to produce the crystal defect, a breakdown electric field of the buried oxide layer is smaller and the breakdown voltage is decreased. Consequently, as a condition capable of obtaining the high breakdown electric field of the buried oxide layer and of achieving the low dislocation density in the top silicon layer, at an acceleration energy of 150-200 keV, for example, the ion implantation has been practiced by setting the dose of ions at around 0.4xc3x971018/cm2 (J. Mater. Res., Vol. 8, No. 3, 1993 pp. 524-534).
If a polarizable layer is formed in the buried oxide, then the polarizable layer/buried oxide combination can be used for the fabrication of non-volatile memory.
Accordingly, it is one object of the present invention to provide a novel process for creating a polarizable buried oxide in SOI substrates.
It is another object of this invention to provide a process for creating a polarizable buried oxide in SOI substrates by the implantation of ions.
It is another object of this invention to provide a process for creating a polarizable buried oxide in SOI substrates by the implantation of silicon ions into the buried oxide.
It is another object of this invention to provide a process for creating a polarizable buried oxide in SOI substrates by the channeling and implantation of ions such that damage effects to the top silicon region are reduced.
These and other objects, which will become apparent during the following detailed description, have been achieved by the inventors"" discovery that a polarizable buried oxide layer in a SOI substrate may by prepared by:
externally heating the silicon-on-insulator substrate;
implanting ions into the buried oxide layer; and
annealing the silicon-on-insulator substrate.
The present invention provides a process for forming a polarizable layer in a buried oxide layer of a silicon-on-insulator substrate for the fabrication of non-volatile memory, the process comprising:
externally heating the silicon-on-insulator substrate;
implanting ions into the buried oxide layer; and
annealing the silicon-on-insulator substrate.
A typical SOI includes a silicon substrate, an active silicon layer, and a buried oxide layer sandwiched between the active silicon layer and the silicon substrate. Generally, the buried oxide layer rests directly on and physically contacts the silicon substrate. Also, the active silicon layer generally rests on and physically contacts the buried oxide layer. The buried oxide layer electrically isolates the active silicon layer from the silicon substrate.
During the implantation stage, the dose of the implanted ion should be as high as can be obtained without damaging the active Si layer to such an extent that a subsequent anneal will not essentially rectify the damage.
Channeling of the ions during the implantation stage may minimize the damage to the active Si layer. Channeling, however, is not required according to the present invention.
The depth of the implant is determined by the energy. The implant energy required to obtain the desired implantation profile in the buried oxide layer will vary depending upon the implanted species, the thickness of the active Si layer and the angle of implantation. Other factors, such as the density of the buried oxide layer may also effect the required implantation energy. Thus, the energy required to obtain the desired implantation profile in the BOX is best determined empirically for each situation, using the knowledge of those skilled in the art of ion implantation. Typically, the peak implant concentration is 5 to 50 nm from the top silicon/buried oxide interface. Most typically, the peak implant concentration is about 20 nm from the top silicon/buried oxide interface.
Typically, the step of externally heating the substrate is carried out at temperatures of 25 degrees Celsius to 300 degrees Celsius.
Typically, the step of implanting is carried out such as to supply a dose of ions of 1xc3x971015 cmxe2x88x922 to 1xc3x971017 cmxe2x88x922, depending on the desired poling voltage of the MOS transistor fabricated on the top-silicon.
Typically, the step of annealing is carried out at temperatures of 900 degrees Celsius to 1000 degrees Celsius. Annealing removes residual damage in the active Si layer and stabilizes the Si-implanted buried oxide layer. At temperatures below about 800 degrees Celsius, no significant annealing occurs. At high temperatures, either the Si active layer melts or contamination becomes a greater concern. Generally, annealing is performed for about 1-5 hours. If the annealing time is overly long, the Si in the substrate may begin to reduce the BOX layer. Generally, the post-implantation anneal is performed either in vacuo or under an atmosphere that is non-reactive with the SOI structure.

Creation of a polarizable layer in the buried oxide of silicon-on-insulator substrates for the fabrication of non-volatile memory

The United States of America as represented by the Secretary of the Navy