MXPA00006462A - Styrene copolymer compositions having reduced surface gloss and composite articles incorporating same - Google Patents

Abstract

The invention provides a weatherable low gloss styrene copolymer composition which requires the addition of from 0.1 to 20%by weight of the total composition, of a partially crystalline polymer such as a polyalkylterephthalate, especially polybutyleneterephthalate or polyethyleneterephthalate, or polyethylenenaphthalate to a styrene copolymer (A). The low gloss styrene copolymer composition of the invention has a graft copolymer resin which results from polymerizing one or more monomers (A1) selected from the group consisting of (i) aromatic vinyl compounds, (ii) ethylenically unsaturated compounds, and (iii) mixtures thereof, in the presence of an elastomeric rubber (A2) in particulate form. The elastomeric rubber (A2) in particulate form results from polymerizing one or more monomers selected from the group consisting of (i) alkyl acrylates having from 1 to 8 carbon atoms, (ii) butadiene, (iii) olefin compounds, (iv) ethylenically unsaturated compounds, (v) aromatic vinyl compounds, (vi) polyfunctional monomers having a crosslinking effect, and (vii) mixtures thereof. The invention further provides a method of reducing the surface gloss of a styrene copolymer resin by adding to a styrene copolymer resin (A), from 0.1 to 20%by weight of a partially crystalline polymer such as a polyalkylterephthalate (B), based on the total weight of the composition. The invention also provides a composite suitable for use as exterior siding for a structure, the composite comprising at least one interior layer (I) comprising a thermoplastic resin, and at least one exterior layer (II) having a low gloss styrene copolymer comprising the low gloss styrene copolymer composition of the invention, wherein exterior layer (II) is continuous and coextensive with interior layer (I).

Description

COMPOSITIONS OF STYRENE COPOLYMER WHICH HAVE REDUCED SURFACE BRIGHTNESS AND COMPOSITE ARTICLES THAN INCORPORATE Description This invention relates to styrene copolymer compositions having reduced surface gloss, a method for reducing the surface gloss of a styrene composition, composite articles incorporating these compositions and a process for preparing these composite articles. More particularly, this invention relates to weather-resistant styrene copolymer compositions, especially to acrylonitrile-styrene-acrylate ("ASA") compositions having reduced surface gloss and to multilayer composites incorporating the compositions. The compounds are useful as wallcovering materials for the construction industries. Two-phase styrene copolymer resins composed of a resin matrix and an elastomeric or rubber component are known to provide a number of useful properties. Illustrative examples are ASA resins, olefin-styrene-acrylonitrile (OSA) or acrylonitrile-EPDM-styrene (AES), and acrylonitrile-butadiene-styrene (ABS). These resins find use in a variety of applications in the markets of the construction (linings of domestic and commercial walls, profiles of windows and doors, channels), in applications of entertainment and recreation (inks of hydromassage (spas), marine components, furniture for exteriors, components of snowmobiles, recreational vehicles, motor homes, towing vehicles for camping, etc.), and in the automotive industry (side moldings for bodies, bumpers, interior decorative finishes and mirror housings). Depending on the resin and particular elastomeric composition, various performance characteristics are possible. For example, ABS resins provide excellent impact resistance at low temperature and processability. ASA and AES resins are particularly known for their convenient impact strength, processability and weather resistance, that is, good color retention and properties after prolonged outdoor exposure. Extruded articles of ABS, AES or ASA generally exhibit a surface gloss that falls within the high gloss range (90 units of brightness at 75 °) or medium brightness range (60 units of brightness at 75 °). The prior art has long desired to provide styrene copolymer resins and / or compositions that possess the above advantageous performance and physical characteristics but exhibit a low gloss surface appearance. In particular, it would be advantageous to provide ABS, ABS and ASA compositions, especially ASA compositions having low brightness and desirable performance properties. These compositions would be of benefit in the construction industry, especially with respect to the manufacture of linings for walls. Attempts by the prior art to provide styrene copolymer compositions having a reduced surface gloss have included embossing mold surfaces and applying a low gloss coating material to the surface of a molded plastic article. These methods failed to provide a sufficient reduction in surface gloss and were disadvantageous with respect to processing, cost and / or performance considerations. Various other attempts of the prior art have focused on the addition or modification of a particular rubber or elastomeric component. The patent of the U.S.A. No. 5,081,193 discloses a low gloss agent for thermoplastic resins comprising a graft copolymer containing a rubber component, especially a low cis polybutadiene.

The patent of the U.S.A. No. 5,237,004 discloses thermoplastic polymer compositions having reduced surface gloss due to the presence of polymer particles from 2 to 15 microns and having a particular core / shell structure. The patent of the U.S.A. No. 5No. 475,053 describes molding compositions having a matte surface comprising a modified impact thermoplastic A and an agent producing a matte finish B. The thermoplastic resin A can ABS, ASA or the like. The dyeing agent B is a particular graft copolymer having from 30 to 80 of a particularly specified elastomeric graft base and from 20 to 70% of a particularly specified graft liner. The patent of the U.S.A. No. 4,652,614 discloses molding materials having a matte surface that is based on neutral and acidic graft polymers. The patent of the U.S.A. No. 4,169,869 describes ABS compounds having low gloss or matte finish. The claimed compositions are obtained by including polybutadiene and a copolymer of butadiene and acrylonitrile in ABS. The patent of the U.S.A. No. 4,668,737 discloses graft polymers having a matt surface. The claimed polymers require from 20 to 0.1 part by weight of a base containing vinyl group, preferably heterocyclic nitrogen, from 40 to 99.8 parts by weight of particular vinyl aromatic monomers, from 20 to 0.1 parts by weight of a mono- or di- -acid containing a polymerizable double bond and from 0 to 40 parts by weight of acrylonitrile in a particular rubber having an average particle diameter from 0.05 to 20.0 microns and a glass transition temperature less than or equal to 10 degrees C, the content of total rubber represents between 5 and 80% by weight. However, previous prior art attempts have generally been characterized by one or more disadvantages, especially with respect to the desirability of surface gloss reduction, surface appearance quality, cost considerations, ease of manufacture, ease of processing and / or the performance properties of the compositions. Accordingly, it would be advantageous to provide a method for reducing the surface gloss of styrene copolymer compositions, particularly with respect to molded articles made from these styrene compositions, especially ASA. It would be convenient to provide styrene copolymer compositions, especially ASA compositions, which exhibit desirable performance properties, a reduction in surface gloss compared to traditional styrene copolymer compositions, advantageous cost considerations and ease of fabrication and / or processing. It would also be convenient to provide composite structures incorporating these low gloss styrene compositions, especially ASA compositions, which are suitable for use as wall liners, as well as a method for the manufacture of these compounds. An object of this invention is to provide styrene copolymer compositions, especially ASA compositions, which exhibit a reduced surface gloss when processed. Another object of this invention is to provide a method for reducing the surface gloss of commercially available styrene copolymer compositions. In particular, an object of this invention is to provide a method for reducing the surface gloss of commercially available styrene copolymer compositions, especially ASA compositions, which are advantageous with regard to cost and ease of manufacture. Finally, an object of the invention is to provide a compound incorporating prior low gloss styrene copolymer compositions as an outer layer and a method for producing these compounds. In particular, it is an object of the invention to provide low gloss styrene copolymer compositions, especially low gloss ASA compositions, which can be used in the fabrication of low gloss, weather resistant outer wall composite structures. and a method for making these wallcovering compositions. This invention satisfies the above objectives and more by providing a particular low gloss styrene copolymer composition., which requires the addition, preferably from 0.1 to 20% by weight of the total composition, of a crystalline polymer partially as a mat imparting agent. In one aspect of the invention, a polyalkylene terephthalate, or a mixture of different polyalkylene terephthalates, especially polybutylene terephthalate or polyethylene terephthalate, is used as a mat imparting agent. Instead of a polyalkylene terephthalate, a polyalkylene naphthalate or a mixture thereof can also be used as a bad agent. It is also possible to use a mixture of different polyalkylene naphthalates. Among the polyalkylene naphthalates, polyethylene naphthalate is preferred. According to another aspect of the invention, polyamide, polyamide copolymers or a mixture of different polyamide or polyamide copolymers can be used as a mat imparting agent. The low gloss styrene copolymer composition of the invention has a graft copolymer resin (A) resulting from polymerizing one or more monomers (Al) selected from the group consisting of (i) vinyl aromatic compounds, (ii) ethylenically compounds unsaturated and (iii) their mixtures, in the presence of an elastomeric rubber (A2) in the form of particles. The elastomeric rubber (A2) in the form of particles results from polymerizing one or more monomers selected from the group consisting of (i) alkyl acrylates having from 1 to 32, preferably 1 to 8 carbon atoms, (ii) butadiene or isoprene , (iii) olefin compounds (other than ii), (iv) ethylenically unsaturated compounds, (v) vinyl aromatic compounds, (vi) polyfunctional monomers having an entanglement effect and (vii) their mixtures. The low gloss thermoplastic resin compositions of the invention require from 0.1 to 20% by weight of the matte imparting agent (B), all percentages by weight are based on the total weight of the composition. The invention further provides a method for reducing the surface brightness of a styrene copolymer resin, by adding to a styrene copolymer resin when adding to a styrene copolymer resin (A), from 0.1 to 20% by weight of the styrene agent. imparts a matte finish (B), based on the total weight of the composition, preferably at temperatures of about 20 ° C below the melting point of (B) to temperatures above the melting point of (B). Finally, the invention also provides a composite suitable for use as an outer liner for a structure, the composite comprises at least one inner layer (I) comprising a thermoplastic resin, and at least one outer layer (II) having a low gloss styrene copolymer comprising the above copolymer (A) and from 0.1 to 20% by weight of the imparting agent matte finish (B), all percentages given by weight based are given based on the total weight of the composition, wherein the outer layer (II) is continuous and coextensive with the inner layer (I). Figure 1 is an enlarged partial cross-sectional view of one embodiment of the composite structure of the invention showing an outer layer of weather-resistant styrene copolymer adhered to an inner layer of polyvinyl chloride (PVC). In one aspect, in its most preferred embodiment, the present invention is intended to provide a low gloss styrene copolymer composition comprising a copolymer of styrene (A) and a polyalkylene terephthalate or a polyalkylene naphthalate (B). In another aspect in its most preferred embodiment, the present invention is intended to provide a low gloss styrene copolymer composition comprising a styrene copolymer (A) and a polyamide or polyamide copolymer (B). As used herein, the term "low gloss" refers to a measure of surface gloss that falls within the range of 15 to 45 gloss units as measured by the BYK / Gardner gloster at 75 °. Gloss is typically measured in an extruded monolayer styrene copolymer or co-extruded sheets having an outer layer of styrene copolymer, the thickness of the styrene copolymer in any case is generally in the range of 0.127 to 1.27 mm (5 to 50 mils). Styrene copolymers as used herein, generally refer to polymer compositions or resins resulting from the polymerization or copolymerization of at least one vinyl aromatic monomer. Preferably, at least vinyl aromatic monomer will be copolymerized with vinyl cyanide. More preferably, all or at least part of the vinyl aromatic monomer and the vinyl cyanide will at least be copolymerized in the presence of an elastomeric or rubber component. The styrene copolymers suitable as component (A) of the invention are preferably graft copolymers. More preferably, the graft copolymers will have a core / shell structure. Preferably, the styrene copolymer (styrene resin (A)) will contain certain rubber particles (A2) grafted with one or more monomers (Al). In some cases, at least the vinyl aromatic monomer and the vinyl cyanide will at least be copolymerized in the presence of a linear polyalkyldiene. Preferably, this graft cover of the rubber particles will be formed by polymerizing styrene and acrylonitrile in the presence of the rubber. Equally convenient as component (A) are mixtures of graft copolymers and polymers or copolymers of at least one vinyl aromatic monomer and at least one vinyl cyanide monomer (A3). This mixture can already be prepared by mixing graft copolymer with (A3) or formed in situ. The latter is the case where not all vinyl aromatic monomers or vinyl cyanide are grafted onto the elastomeric or rubber component. The styrene resin (A) will generally result from the polymerization or copolymerization of at least one monomer (Al). The monomers (Al) in general can be those monomers used in the production of styrene copolymers. These monomers are typically described as (i) vinyl aromatic compounds, (ii) ethylenically unsaturated compounds and / or (iii) their mixtures. Illustrative examples of vinyl aromatic compounds (i) are styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, p-methylstyrene, 1,3-dimethylstyrene, tert-butylstyrene, vinylnaphthalene, and the like. Preferred aromatics (i) are styrene, α-methylstyrene, p-methylstyrene and tert-butylstyrene. More preferred aromatic compounds (i) are styrene and α-methylstyrene. Illustrative examples of ethylenically unsaturated monomers (ii) are compounds such as vinyl cyanides such as acrylonitrile, methacrylonitrile, alkyl acrylates and alkyl methacrylates having from 1 to 4 carbon atoms in the alkyl portion, acrylic acid, methacrylic acid, maleic anhydride, acrylamide and / or vinyl methyl ether. Preferred ethylenically unsaturated monomers (ii) are vinyl cyanides such as acrylonitrile. When the styrene resin (A) results only from the polymerization or copolymerization of one or more monomer (s) (Al), the amounts of monomers (i) and / or (ii) depend on the desired resin properties (A).

However, it is particularly preferred that one or more monomers (Al) contain at least one monomer which is a vinyl aromatic compound (i). Preferably, one or more monomers (Al) will have at least 20% by weight of an aromatic vinyl compound (i), based on the total weight of one or more monomers (Al). More preferably, one or more monomers (Al) will have from 30 to 85, preferably from 30 to 75, percent by weight of the vinyl aromatic compound (i). The monomers (Al) can be polymerized by traditional processes known to those skilled in the art. The polymerization can be carried out in bulk, solution, suspension or aqueous emulsion. Free radical polymerization is preferred. Especially when (A) is SAN and monomers (Al) are styrene and acrylonitrile. * The styrene resin component (A) can also be a graft copolymer resin as is well known in the art. An illustrative example is described in U.S. Pat. No. 4,634,734, here incorporated by reference completely. For example, the resin (A) may comprise the result of polymerizing one or more monomers (Al) in the presence of elastomeric rubber (A2). Elastomeric rubber (A2) can also be referred to as a graft base. It will be appreciated that a large variation in the performance properties of the resin (A) can be obtained depending on the selection of rubber or graft base (A2).

Examples of suitable rubbers (A2) are polybutadiene, polyisoprene, styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, alkyl acrylate rubbers, EPM rubbers (ethylene / propylene rubbers), EPDM rubbers (ethylene / propylene / diene rubber containing a non-conjugated diene, such as for example 1, 5-hexadiene or norbornadiene, in small amounts such as diene) and silicone rubbers. Those skilled in the art will appreciate that the elastomeric rubber (A2) can result from the polymerization or copolymerization of one or more monomers (A2 ') selected from the group consisting of (i) alkyl acrylates having 1 to 8 carbon atoms in the alkyl group, (ii) a 1,3-diene, (iii) olefinic compounds, (iv) ethylenically unsaturated compounds, (v) vinyl aromatic compounds, (vi) polyfunctional monomers having an entanglement effect and (vii) their mixtures . The rubber (A2) can result from the polymerization or copolymerization of one or more monomers (A2 ') selected from the group of (i) alkyl acrylates having from 1 to 8 carbon atoms in the alkyl group. Alkyl acrylates having from 4 to 8 carbon atoms in the alkyl portion are preferred. More preferred examples are n-butyl acrylate and ethylhexyl acrylate. The monomer (A2 ') can be one or more alkyl acrylates alone or in mixture with each other. Suitable alkyl acrylates may also be mixed with suitable monomers selected from the monomers (ii) - (vi) described herein. One or more monomers (A2 ') can also be selected from the group consisting of 1,3 dienes (ii). Illustrative examples are butadiene, isoprene and the like. The 1,3-dienes can be used alone, in a mixture with another 1,3 dienes or in a mixture with other suitable monomers selected from monomers (i) and / or (iii) - (vi) described herein. For example, it will be appreciated that when the resin (A) is an ABS resin, the rubber (A2) can be a conjugated diolefin polymer latex, such as polybutadiene or a butadiene copolymer of butadiene-styrene, butadiene-acrylonitrile, butadiene. -alkyl acrylates and the like. The monomers (A2 ') can also be one or more olefins (iii). Illustrative examples of olefins (iii) are those aliphatic compounds having from 2 to 4 carbon atoms such as ethylene, propylene, butylene and the like. Ethylene and propylene are preferred. Olefins (iii) can be used alone as a monomer (A2 ') or in a mixture with one another or in a mixture with one or more other monomers selected from monomers (i) - (ii) and / or (iv) - (vi). The monomers (A2 ') can be selected from monomers that are ethylenically unsaturated compounds (iv). Ethylenically unsaturated compounds suitable for use as the monomer (iv) and therefore the monomer (A2 '), are those described above with respect to monomers suitable for use as one or more monomers (Al) (ii). Other illustrative examples include hydroxyalkyl acrylates or methacrylates. Preferred hydroxyalkyl acrylates / methylacrylates are those having from 2 to 6 carbon atoms in the alkyl portion. One or more of the monomers (A2 ') can be an ethylenically unsaturated compound alone, or in admixture with another ethylenically unsaturated compound or an ethylenically unsaturated compound in admixture with one or more other monomers selected from the monomers (i) - (iii) and / or (v) - (vi). One or more monomers (A2 ') may be selected from vinyl aromatic compounds (v). Vinyl aromatic compounds suitable for use as the monomers (v) and therefore one or more monomers (A2 ') are those described above with respect to the monomers (Al) (i). Styrene is particularly preferred to be used as a monomer (v). One or more of the monomers (A2 ') can be a vinyl aromatic compound alone or in mixture with another vinyl aromatic compound, or a vinyl aromatic compound in admixture with one or more other monomers selected from monomers (i) - (iv) and / or (vi) .

Suitable monomers for use as polyfunctional monomers (vi) having an entanglement effect are those containing at least two double bonds capable of copolymerization. Examples are divinylbenzene, diallyl maleate, diallylfuramate, diallyl phthalate, allyl methacrylate, butanediol diacrylate, hexanediol diacrylate, butadiene, isoprene, triallyl cyanurate and triallyl isocyanurate. A preferred monomer (vi) is the acrylic ester of tricyclodecenyl alcohol. Elastomeric rubber (A2) can be made by polymerization processes known to those skilled in the art. These processes include emulsion polymerization and bulk or solution polymerization followed by emulsification of the resulting polymers. An illustrative example of emulsion polymerization is described in U.S. Pat. No. 5,252,666 and DE 12 60 135, both of which are hereby incorporated by reference in their entirety. It will be appreciated that the graft copolymers according to use of this invention can and preferably will have a core / shell structure. These structures are described in U.S. Pat. No. 5,252,666. It will be appreciated that the anterior rubber (A2) generally in the form of the core. The surrounding core can be formed by the polymerization of monomers (Al) or the like in the presence of elastomeric rubber (A2). These processes are also described in U.S. Pat. No. 5,252,666. A more preferred rubber will have a weight average particle size from 50 to 600 nm. The polymer surrounding the core / shell particles will generally be surrounded by a polymer matrix, typically a rigid copolymer. Those of skill in the art will appreciate that these may comprise the ungrafted monomers free from polymerization (Al) resulting from the polymerization of monomers (Al) in the presence of elastomeric core (A2) and the production of the desired core / shell structure. Alternatively, the resin (A) may be formed from mixing polymer or copolymer prepared separately (A3) with either elastomeric rubber (A2) or the result of polymerizing monomers (Al) in the presence of elastomeric rubber (A2) ), ie graft copolymers having a core / shell structure. Copolymer (A3) will generally result from the polymerization or copolymerization of one or more monomers such as those described above with respect to the monomers (Al). Styrene, alpha methyl styrene, and acrylonitrile are preferred, with preferred mixtures of styrene and acrylonitrile in particular. (A3) can be a mixture of copolymers, ie styrene-acrylonitrile copolymer with α-methylstyrene-acrylonitrile copolymers. The copolymer (A3) will generally have from 20 to 50 weight percent of monomers (Al) (ii), based on the weight of copolymer (A3). The monomers (Al) (ii) are preferably present in an amount of 10 to 94, such as 35 to 94, preferably 10 to 90 percent by weight, based on the weight of the total composition of (Al), (A2) and (A3). The copolymer (A3) can thus be a styrene / acrylonitrile copolymer, an alpha methylstyrene / acrylonitrile copolymer, a styrene / methyl methacrylate copolymer, a styrene / maleic anhydride copolymer or an alpha-methylstyrene / styrene / acrylonitrile , a styrene / acrylonitrile / methylmethacrylate terpolymer, a styrene / acrylonitrile / maleic anhydride or a styrene / acrylonitrile / acrylic acid terpolymer, or an alpha-methylstyrene / styrene / acrylonitrile terpolymer or mixtures thereof. If the copolymer (A3) consists of a mixture of the above, the acrylonitrile content of the various copolymers containing acrylonitrile should preferably not differ from each other by more than 10 percent, more preferably not more than 5 percent by weight based on in the copolymer.

More preferably, the copolymer (A3) will be a styrene-acrylonitrile SAN resin or an a-methylstyrene-acrylonitrile resin or mixtures thereof. Suitable SAN copolymers are those discussed above with respect to the copolymer (Al). A commercially available SAN resin suitable for use in the present invention as component (A3) is the SAN LURANMR resin, available from BASF Corporation, Wyandotte, MI. Particularly convenient and preferred commercially available materials are SAN LURANMR grades 358N, 368R, 378P and 388S. These are characterized by their content of styrene, α-methylstyrene and / or substituted styrene of 50 to 100, preferably of SAN. 60 to 95, 60 to 90% by weight based on SAN is especially preferred. Its content of (meth) acrylonitrile can be up to 42%, preferably from 5 to 40, in particular from 7 to 38% by weight, based on the SAN. The remaining portions can be alkyl esters of 1 to 8 carbon atoms of (meth) acrylic acid, maleinimide, N-methyl-N-phenyl- or N-cyclohexylmaleimide or maleic anhydride. Their viscosity numbers are generally from 40 to 160, preferably from 45 to 120 ml / g (as measured in accordance with DIN at 53 726 at 25 ° C in 0.5% by weight of dimethylformamide), which corresponds to a weight molecular weight (Mw) from 40,000 to 200,000 g / mol.

Polymerization processes such as those described above with respect to the polymerization of monomers (Al) are suitable for the production of copolymer (A3). In general, copolymers (A3) will have viscosity numbers from 40 to 100, in particular from 50 to 90. If the copolymer (A3) does not result from the polymerization of monomers (Al) in the presence of elastomeric rubber (A2), the copolymer (A3) can be incorporated with the result of polymerizing monomers (Al) in the presence of elastomeric rubber (A2), by processes known to those skilled in the art. The copolymer (A3) can be mixed immediately with the result of polymerizing the monomers (Al) and (A2 '), or they can be mixed in smaller proportions. Traditional formulation techniques such as extrusion formulation using single screw extruders or cufflinks can be employed. For example, a preferred method is to intensively mix a blend of the copolymer (A3) with the result of copolymerizing graft copolymer (Al) and (A2) at temperatures above 200CC. Alternatively, if the various copolymer components were prepared by emulsion polymerization, the resulting polymer dispersion can be mixed and the polymer blend processed. Preferably, the copolymer (A3) will be mixed with the graft copolymer of (Al) and (A2) by combined extrusion, kneaded or bent on themselves from the components. Those skilled in the art will appreciate that prior to this it is necessary to isolate the components of the aqueous solution or dispersion resulting from the polymerization. Partial dehydration of the graft copolymerization products obtained in an aqueous dispersion ie graft copolymer of (Al) in (A2), is also possible and can be mixed with the copolymer (A3) as impregnated lumps with complete drying of the copolymerized graft copolymer blends which is carried out during the mixing process. Styrene copolymer resin (A) may additionally contain additives such as are commonly included for styrene copolymer resins. Examples include fillers, other compatible plastics, antistatics, antioxidants, flame retardants and lubricants. These additives are commonly used in amounts of 0.1 to 70 parts by weight based on 100 parts by weight of the resin (A), or (Al) + (A2) + (A3). In addition, dyes and pigments may be incorporated in the resin (A) in amounts of 0.02 to 10 parts by weight, based on the weight of the resin (A).

While the resin (A) can be any of the styrene copolymer resins discussed above, ie SAN, ASA, ABS, AES, or the like, it is preferred that the resin (A) be SAN, ABS or ASA. More preferably, the resin (A) will be ASA. An illustrative and convenient resin (A) can have an elastomeric phase (A2) of bu ti 1 ac ri 1 atoy tricyclodecenyl acrylate and is grafted with (Al) styrene and acrylonitrile in a ratio of 75 to 25 and mixed with a styrene copolymer acrylonitrile or de-α-methylstyrene-acrylonitrile copolymer (A3) having an acrylonitrile content of 22 to 35 percent. Particularly convenient and commercially available ASA resins suitable for use in the present invention as resin (A) are the ASA LURANMR resins available from BASF Corporation, Wyandotte, MI. A more preferred resin (A) is the resin ASA LURANMR S grade 797 SE UV. According to the invention, the matte imparting agent (B) is a partially crystalline polymer. Among these partially crystalline polyesters, polyamides or copolymers thereof can be used as component (B). Mixtures of different partially crystalline polymers can also be used as a matt-imparting agent (B).

According to one aspect of the invention, component (B) is a polyalkylene terephthalate or polyalkylene naphthalate having an alkyl group of 2 to 10, in particular 2 to 4, carbon atoms. Polybutylene terephthalate and polyethylene terephthalate and polyethylene naphthalate are particularly preferred. Of course it is also possible to use mixtures of different polyalkylene terephthalates or polyalkylene naphthalates as well as mixtures of one or more polyalkylene terephthalates and polyalkylene naphthalates. The polyalkylene terephthalates or polyalkylene naphthalates may also contain units derived from isophthalic acid. Up to 30 mol%, preferably not more than 10 mol% of the aromatic dicarboxylic acid units can be replaced by dicarboxylic, aliphatic or cycloaliphatic acid units such as units derived from adipic acid, azelaic acid, sebacic acid, dodecandibic acid or cyclohexanedicarboxylic acids. The alkylene units may be derived from diols, in particular 1,2-ethanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethylanol or neopentyl glycol or their mixtures Suitable polyalkylene terephthalates or polyalkylene naphthalates will have a viscosity number determined in accordance with ISO 1628-5 in phenol / 1,2-dichlorobenzene (1/2) of 50-200 ml / g, preferably 70-170 ml / Y in particular between 90 -140 ml / g. The polyalkylene terephthalates or polyalkylene naphthalates will preferably be uncharged. Illustrative commercially available polyalkylene terephthalates suitable for use as component (B) are the polybutylene terephthalate resins ULTRADUR available from BASF Corporation, Wyandotte, MI. A more preferred component (B) is the resin ULTRADURMR grade B2550. According to another aspect of the invention, the agent imparting matte finish B can be a polyamide or mixture of different polyamides. One of the preferred polyamides is polyamide 6.6. In particular B is a partially aromatic copolyamide or a mixture of two or more different partially aromatic copolyamides. The partial aromatic copolyamides B) present in the styrene copolymer compositions according to the invention contain as component B?) 20 -90% by weight of units derived from terephthalic acid and hexamethylene diamine. A small proportion of terephthalic acid, preferably not more than 10% by weight of the total aromatic dicarboxylic acids used, can be replaced by isophthalic acid or other aromatic dicarboxylic acids, preferably by those in which the carboxyl groups are in the para position.

In addition, the units derived from terephthalic acid and hexamethylenediamine, copolyamides B) contain as component B2) units derived from e-caprolactam and / or contain as component B3) units derived from adipic acid and hexamethylenediamine. The proportion of units derived from e-caprolactam is not greater than 50% by weight, preferably 20-50% by weight, in particular 25-40% by weight, while the proportion of units derived from adipic acid and hexamethylenediamine is up to 80% by weight, preferably 30-75% by weight, in particular 35-65% by weight. Copolyamides B) may also contain units that are not only of e-caprolactam but also of adipic acid and hexamethylenediamine; in this case, it is advantageous that the proportion of units that are free of aromatic groups is not less than 10% by weight, preferably not less than 20% by weight. The proportion of units derived from e-caprolactam and units derived from adipic acid and hexamethylenediamine is not subject to any particular restriction here. Preference is given to copolyamides whose composition in a ternary diagram is within the pentagon defined by the corner points Xx to X5 which in each case are defined as follows:? 40% by weight of Bx units) 60% by weight of units B3) X 60% by weight of Bx units) 40% by weight of units B3) X 80% by weight of units B- 5% by weight of units B2) 15% by weight of units B3) X 80% by weight of units Bx) 20% by weight of units B2) X 50% by weight of units B?) 50% by weight of units B2) The drawing shows the pentagon defined by these points within a ternary diagram (Figure 2). Particularly advantageous for many purposes has been found to present polyamides containing 50-80, in particular 60-75% by weight of units derived from terephthalic acid and hexamethylenediamine (Bx units)) and 20-50, preferably 25-40% by weight units derived from e-caprolactam (units B2)). In addition to the units described above Bx) to B3), the partially aromatic copolyamides B) may additionally contain minor amounts, preferably not more than 15% by weight, in particular not greater than 10% by weight, of additional polyamide units of Known type of other polyamides. These units can be derived from dicarboxylic acids of 4-16 carbon atoms and aliphatic or cycloaliphatic diamines with 4-16 carbon atoms and aminocarboxylic acids and the corresponding lactams of 7-12 carbon atoms. Suitable monomers of these types are suberic acid, azelaic acid, sebacic acid and isophthalic acid, simply mentioned as representative of dicarboxylic acids, 1,4-butanediamine, 1,5-pentanediamine, piperazine, 4,4'-diaminodicyclohexylmethane, 2, 2 - (4,4'-diaminodi-cyclohexyl) -propane and 3,3'-dimethyl-4,4'-diaminodicyclohexyl-methane, simply mentioned as representative of diamines and capryl lactam, enantolactam, omega-aminoundecanoic acid and laurolactam, simply mentioned as representative of lactams and aminocarboxylic acids. Particularly advantageous it has been found that partially aromatic copolyamides whose triamine content is less than 0.5, preferably less than 0.3% by weight. Most of the existing processes give partially aromatic copolyamides having triamine contents above 0.5% by weight, which have an adverse effect on product quality and leads to problems in continuous production. A particular triamine responsible for these problems is dihexamethylenetriamine, which is formed from the hexamethylenediamine starting material.

Copolyamides having low triamine content have lower melt viscosities if compared at the same rate of solution with products of the same composition, but at a higher triamine content. This fact has positive effects not only on the processability but also on the product characteristics. The melting points of partially aromatic copolyamides B) are within the range of 260 ° C over 300 ° C, that high melting point is also associated with a high glass transition temperature, generally greater than 75, in particular greater than 85 ° C (in the dry state). Binary copolyamides based on terephthalic acid, hexamethylenediamine and e-caprolactam have and contain about 70% by weight of units derived from terephthalic acid and hexamethylenediamine, melting points within the range of 300 ° C and (in the dry state) a temperature of glass transition greater than 110 ° C. Binary copolyamides based on terephthalic acid, adipic acid and hexamethylenediamine have melting points of 300 ° C or more at even lower levels of about 55% by weight units of terephthalic acid and hexamethylenediamine (HMD), although the glass transition temperature does not TS as high as in the case of binary copolyamides containing e-caprolactam instead of adipic acid or adipic acid / HMD. The partially preferred, low triamine content aromatic copolyamides can be prepared by the processes described in EP-A-129, 195, -129.196 and US Pat. No. 5,252,661. Component B can be added to the resin component (A) by traditional formulation methods known to those skilled in the art and as discussed above with respect to the incorporation of copolymer (A3). More preferably, the component (B) will be mixed with the resin component (A) using a twin-screw formulation extruder or equivalent, especially those having a size (spindle diameter) of 40 mm or greater. Preferably, during the addition of component B to component A, temperatures above the melting temperature of B should be used at a temperature that is lower than the melting temperature of B by 20 ° C. According to one aspect, it is preferred that during the addition of component B to component A, temperatures should not exceed 300 ° C, or more preferably 250 ° C. The method and composition of the invention generally requires that not more than 20% by weight of the total composition of A + B be constituted by component B. Amounts of component B greater than 20% by weight of the total composition were found to affect the performance properties of the finished composition, especially with respect to impact properties. Those skilled in the art will appreciate that when the composition of A + B comprises more than 50% B, the main phase becomes B and is no longer a styrene copolymer. It is desirable that the compositions of the invention have an optimum balance of low gloss and performance properties, especially impact properties. The compositions of the invention will have from 0.1 to 20% of component (B). Preferably, the compositions of the invention will have from 2 to 10% and more preferably from 4 to 8% by weight of the component (B), based on the weight of the components (A) and (B). The low gloss styrene compositions of the invention will generally have an average surface gloss reading of 15 to 45, as measured at 75 °. Brightness readings of 15 to 35 to 75 ° are particularly preferred. The compositions of the invention are furthermore characterized by useful performance properties especially with respect to impact resistance.

Although the compositions of the invention will find use in a variety of applications, they are particularly well suited for use in exterior applications such as in wall linings, window frames and the like. A more preferred use is in a composite suitable for use as an exterior wall liner for a structure. The compound of the invention has at least one inner layer (I) which is a thermoplastic and at least one outer layer (II), which includes the low-gloss, weather-resistant styrene compositions of the invention. The outer layer (II) will generally be continuous with and in communication with the inner layer (I). Turning to Figure 1, it can be seen that the composite 10 is constituted by the inner layer 12 and the outer layer 14. The composite 10 will be used in such a way that the inner layer 12 is placed in order to protect against exposure to light and the weather, that is, near the surface of a construction or structure, while the weather-resistant layer 14 faces outwardly exposed to light and weather. The inner layer (I) 12 will consist of at least one polymeric layer, but may be a multilayer polymeric structure. The layer 12 will generally be constituted by ABS, PVC (poly (vinylchloride)), or mixtures thereof. Preferably, layer (I) will be a PVC substrate, such as a rigid (unplasticized) PVC substrate with or without additives, such as impact modifiers, (such as CPE, acrylic copolymers, block styrenics); processing aids; thermal and oxidative stabilizers; UV stabilizers; fillers (such as talc, Ti02, calcium carbonate); Pigments and recycled products. The outer layer (II) 14 will be a styrene composition comprising styrene resin (A) and matt finishing imparting agent (B) according to the present invention. More preferably, the outer layer 14 will comprise an ASA resin (A) as described above and 4-8 weight percent matting agent imparting (B), based on weight (A) + (B) . The inner layer (I) 12 will generally have a thickness of .254 to 2.54 mm (10 to 100 mils) and preferably approximately 0.63 to 1.27 mm (25 to 50 mils). The outer layer (II) 14 will generally have an average thickness of 0.127 to 0.381 mm (5 to 15 mils). The outer layer 14 will preferably have an average thickness of 0.127 to 0.254 mm (5 to 10 mils). It will be appreciated that the thickness of both layers 12 and 14 will vary as a result of the coextrusion process. For example, layer 14 typically can show film thickness in the range of 0.178 to 0.279 mm (7 to 11 mils), with an average film thickness of approximately 0.229 mm (9 mils). The compound of the invention will be formed by co-extrusion techniques as is well known to those skilled in the art. The outer layer 12 and the inner layer 14 will be simultaneously extruded in the form of monolayer sheets or multiple layers such that the layer 12 is continuous with and in communication with the layer 14. The co-extrusion process of the compound of the invention, preferably will be out at temperatures below 250 ° C (450 ° F). More preferably, the compound of the invention will be extruded at temperatures between 178 to 222 ° C (320 to 400 ° F). Alternatively, the parts can be formed from the styrene copolymer compositions according to the invention by injection molding. In this way, it is preferred to use injection molding temperatures above the melting temperature of A and below the melting temperature of the melting agent B. The following examples are intended to illustrate but not limit the invention. Example 1 A traditional glossy styrene copolymer composition for use as a control ("Control ASA Resin") is prepared by adding approximately 2.6% titanium dioxide (Kronos 2220) to the ASA resin LURAN MR S 797 SE UV commercially available from BASF Corporation (a UV stabilized high impact ASA resin with an E module of approximately 2000 MPa determined in accordance with DIN 53457). A low gloss styrene copolymer composition according to the present invention ("Low gloss ASA resin") is prepared by adding approximately 2.6% titanium dioxide (Kronos 2220) and 4.6% resin B2550 PBT from ULTRADUR MR ( polybutylene terephthalate with a viscosity number of 107 ml / g, determined in accordance with DIN 53728) to commercially available ASA LURANMR S 797 SE UV resin from BASF Corporation. Both Control ASA resin and Low Gloss ASA resin are prepared using a twin screw extruder to incorporate Ti02 and PBT. Test plates were extruded using a Dorstener conical screw extruder with 2 V. A blue pigment was dosed into each material during extrusion to simulate coloring systems typically employed by the wallliner industry. A blue pigment was dosed in each material. Each extruded sheet was approximately 1.27 mm (50 mils) thick and enhanced as is typical of PVC wallcovering profiles. The leaves were allowed to cool and the brightness measurements were recorded at 75 ° for each temperature profile. The temperature profiles and processing conditions used are listed in Table 1. Twenty panels of each material were extruded. Of the twenty panels, five were randomly selected for surface brightness measurements. Table 1 Temperature Profiles and Processing Conditions Process Conditions A Process Conditions B Process Conditions C Process Conditions D The results are summarized in Table 2. Table 2 Brightness as a Function of Processing Conditions ASA Control Resin, Select Panel Brightness vs. Processing Temperature 171C / 188C / 204C 221C 340 ° F Brightness 370 ° F Brightness 400 ° F Brightness 430 ° F Brightness Low Gloss ASA Resin, Select Panel Gloss Against Processing Temperature 340 ° F Brightness 370 ° F Brightness 400 ° F Brightness 430 ° F Brightness The surface gloss of the low gloss styrene copolymer composition according to the invention is minimized at the two processing temperatures representative of the processing temperatures employed by the lining industry. Accordingly, the low gloss styrene copolymer composition is advantageous. Examples 2 to 6 and Comparative Example Cl A traditional gloss styrene copolymer composition, it is used as a control ("ASA resin"). It is controlled by 48 parts of crosslinked polybutylacrylate rubber (particle size, 0.5 μm, monodisperse) grafted with styrene and acrylonitrile and 52 parts of a polystyrene-acrylonitrile copolymer (PSAN 1) with 33 parts of acrylonitrile and a viscosity number of 80 ml / g measured as a 0.5 percent solution in dimethylformamide. Except for Ultradur B 2550, the following agents that impart matte finish are used: PolyclearMK RT 51 Polyethylene terephthalate (PET) resin from Hoechst Company, with a viscosity number of 76 ml / g in accordance with ISO 1628 (measured in 0.5% solution) concentration in phenol / dichlorobenzene (1: 1) UltramidMRA3 Polyamide 6.6 from BASF Corporation, with a viscosity number according to DIN 53727 of 143 cm3 / g (measured in solution at a concentration of 0.5% in sulfuric acid) UltramidMR T3: Polyamide 6.6T from BASF Corporation, with a viscosity number of 130 ml / g according to DIN 53727 (measured in 0.5% strength solution in sulfuric acid) UltramidMR Al5: Polyamide 6.6 from BASF Corporation, with a viscosity number of 80 ml / g according to DIN 53727 (measured in 0.5% solution in sulfuric acid) 90 parts of the ASA control product are mixed in a ZSK extruder 30 of the company Werner und Pfleiderer with 10 parts of the following polymers at the following temperatures as illustrated in Table 3. Table 3 The products prepared as illustrated above were then injection molded at the different temperatures shown below into discs with a diameter of 60 mm and a thickness of 2 mm. Using a Dr. Lange Reflectometer, the brightness of the discs (reflected light) is measured at an angle of 60 ° normal to the surface according to DIN 67530 (Table 4). Table 4 11 Measured at an angle of 60 ° 21 Crystalline melting temperature (T ° C), measured using DSC, heating rate ° C / minute). nm not measured * Disc surface contains molding lines, it was not possible to reproduce the measurements. As can be seen, products were obtained that particularly impart a matte finish wherein the injection molding temperatures were lower than the melting temperature of the agent imparting matte finish. Experiments 7 to 10 and Comparative Example C2 In a further set of experiments, the following components were mixed in a ZSK 30 extruder under the same conditions as described in Table 3: 62.5 parts of the control ASA product; 32.5 parts of a PSAN 1; 5 parts of a batch of carbon black at 20% PSAN 1; 7 parts of the agent that imparts matte finish. These compounds were then extruded in a single screw extruder at 230 ° C (Barmag, spindle diameter 45 mm, spindle length 25 D) in 0.7 mm sheets, which were then vacuum-formed at a temperature of 150 ° C. The gloss was measured at an angle of 60 ° C on the upper and bottom sides of the extruded sheets before and after vacuum formation. The results are given in Table 5. Table 5

Claims (13)

1. CLAIMS 1. A low gloss styrene copolymer composition, characterized in that it comprises: (A) a styrene resin comprising the result of polymerizing one or more monomers (Al) selected from the group consisting of (i) vinyl aromatic compounds, (ii) ethylenically unsaturated compounds; and (iii) their mixtures, wherein at least one monomer (Al) is a vinyl aromatic compound, and (B) from 0.1 to 20% by weight of a partially crystalline polymer as a mat imparting agent.
2. 2. The low gloss styrene copolymer composition of claim 1, characterized in that the styrene resin (A) further comprises the result of polymerizing one or more monomers (Al) in the presence of an elastomeric rubber (A2) comprising the result of polymerizing one or more monomers (A2 ') selected from the group consisting of: (i) alkyl acrylates having 1 to 8 carbon atoms, (ii) 1, 3-diene, (iii) olefin compounds (iv) ethylenically unsaturated compounds, (v) vinyl aromatic compounds, (vi) polyfunctional monomers having an interlacing effect, and (vii) their mixtures.
3. 3. The low gloss styrene copolymer composition according to claim 1 or 2, characterized in that the resin (A) further comprises a copolymer (A3) resulting from the copolymerization of one or more reagents selected from the group consisting of (i) vinyl aromatic compounds, (ii) ethylenically unsaturated compounds, and (iii) their mixtures.
4. 4. The low gloss styrene copolymer composition according to claim 1 to 3, characterized in that the agent imparting matte finish is selected from the group consisting of polyamide 6.6, partially aromatic copolyamides containing: Bx) 20 to 90% by weight of units derived from terephthalic acid and hexamethylenediamine, wherein up to 10% by weight of the total aromatic dicarboxylic acids used can be replaced by isophthalic acid or other aromatic dicarboxylic acids, B2) up to 50% by weight of units derived from -caprolactam and B3) up to 80% by weight of units derived from adipic acid and hexamethylenediamine wherein the sum of the percentages by weight of B1 to B3 is 100, polyalkylene terephthalates and polyalkylene naphthalates.
5. 5. The low gloss styrene copolymer composition of claim 1, characterized in that the mat imparting agent: (B) is selected from the group consisting of polybutylene terephthalate, polyethylene terephthalate and polyethylene naphthalate.
6. 6. The low gloss styrene copolymer composition of claim 1, characterized in that it comprises from 2 to 10% by weight of the polybutylene terephthalate, polyethylene terephthalate, polyethylene naphthalate or a mixture thereof based on the total weight of (A) and ( B).
7. 7. The low gloss styrene copolymer composition of claim 6, characterized in that the styrene resin (A) comprises (a) the result of polymerizing one or more monomers (Al) selected from the group consisting of styrene, alpha- methylstyrene, acrylonitrile, and mixtures thereof, (b) in the presence of an elastomeric rubber (A2) comprising the result of polymerizing one or more monomers (A2 ') selected from the group consisting of alkyl acrylates having from 1 to 8 atoms carbon in the alkyl group, polyfunctional monomers having an entanglement effect and mixtures thereof, and (c) a copolymer (A3) comprising the result of polymerizing one or more monomers selected from the group consisting of styrene, alpha-methylstyrene, Acrylonitrile and its mixtures.
8. 8. The low gloss styrene copolymer composition of claim 7, characterized in that it has a gloss of between 15 to 45 to 75 °.
9. 9. A low gloss styrene copolymer composition comprising: (A) a graft copolymer resin comprising linear polybutadiene and one or more monomers selected from the group consisting of: (i) aromatic vinyl compounds, (ii) ethylenically unsaturated compounds, and (iii) their mixtures, and (B) from 0.1 to 20% by weight of a partially crystalline polymer as an agent imparting matte finish.
10. 10. A composite suitable for use as an exterior wallliner for a structure, the composite comprising: (I) at least one inner layer comprising a thermoplastic, and (II) at least one outer layer comprising a copolymer resin composition. of low gloss styrene, comprising (A) a resin comprising the result of polymerizing one or more monomers (Al) selected from the group consisting of (i) vinyl aromatic compounds, (ii) ethylenically unsaturated compounds, and (iii) their mixtures, and (B) from 0.1 to 20% by weight of a partially crystalline polymer as the imparting agent matt finish, wherein the outer layer (II) is continuous and coextensive with the inner layer (I).
11. The compound according to claim 10, characterized in that the resin (A) further comprises the result of polymerizing one or more monomers (Al) in the presence of (2) an elastomeric rubber comprising the result of polymerizing one or more monomers selected from the group consisting of: (i) alkyl acrylates having from 1 to 8 carbon atoms, (ii) butadiene, (iii) olefin compounds, (iv) ethylenically unsaturated compounds, (v) vinyl aromatic compounds, (iv) vi) polyfunctional monomers having an entanglement effect, and (vii) their mixtures.
12. 12. A method of reducing the surface gloss of a styrene copolymer composition, comprising providing a styrene resin (A) comprising the result of polymerizing one or more monomers (Al) selected from the group consisting of: (i) vinyl aromatic compounds, (ii) ethylenically unsaturated compounds, and (iii) their mixtures, and in the presence of (A2) an elastomeric rubber comprising the result of polymerizing one or more monomers selected from the group consisting of: (i) alkyl acrylates having 1 to 8 carbon atoms, (ii) butadiene, (iii) olefin compounds, (iv) ethylenically unsaturated compounds, (v) vinyl aromatic compounds, (vi) polyfunctional monomers having an entanglement effect, and (vii) their mixtures, and mixing the result with a copolymer (A3) which is the result of polymerizing one or more monomers (Al) selected from the group consisting of: (i) vinyl aromatic compounds, (ii) ethylenically unsaturated compounds and (iii) their mixtures, and adding to the styrene resin (A) from 0.1 to 20% by weight of a partially crystalline polymer (B) as a mat imparting agent at a temperature of at least 20 ° C below the melting temperature of (B).
13. 13. Use in partially crystalline polymers of a matt finishing imparting agent for the production of low gloss styrene copolymer compositions comprising: (A) a styrene resin comprising the result of polymerizing one or more monomers (Al) selected from the group which consists of: (i) vinyl aromatic compounds, (ii) ethylenically unsaturated compounds, and (iii) their mixtures, wherein at least one monomer (Al) is a vinyl aromatic compound. SUMMARY OF THE INVENTION The invention provides a low gloss, weather-resistant styrene copolymer composition, which requires the addition of from 0.1 to 20% by weight of the total composition, of a partially crystalline polymer such as a polyalkylterephthalate, especially polybutylene terephthalate or polyethylene terephthalate, or polyethylene naphthalate to a styrene copolymer (A). The low gloss styrene copolymer composition of the invention has the graft copolymer resin resulting from polymerizing one or more monomers (Al) selected from the group consisting of (i) vinyl aromatic compounds, (ii) ethylenically unsaturated compounds, and (iii) their mixtures in the presence of an elastomeric rubber (A2) in the form of particles ?. The elastomeric rubber (A2) in the form of particles results from polymerizing one or more monomers selected from the group consisting of (i) alkyl acrylates having from 1 to 8 carbon atoms, (ii) butadiene, (iii) olefin compounds, (iv) ethylenically unsaturated compounds, (v) vinyl aromatic compounds, (vi) polyfunctional monomers having an entanglement effect and (vii) their mixtures. The invention further provides a method for reducing the surface gloss of a styrene copolymer resin by adding to a styrene copolymer resin (A), of

    0. 1 to 20% by weight of a partially crystalline polymer such as a polyalkylterephthalate (B), based on the total weight of the composition. The invention also provides a compound suitable for use as an outer skin for a structure, the compound comprising at least one inner layer (I) comprising a thermoplastic resin, and at least one outer layer (II) having a styrene copolymer of low gloss comprising the composition of low gloss styrene copolymer of the invention, in the outer layer (II) is continuous and coextensive with the inner layer (I).