IL30142A - Vinyl chloride resin compositions - Google Patents

Description

•ΡΠ73 7Μ*Ί «ρ® 7Β nnanyn VINYL CHLORIDE RESIN COMPOSITIONS ROHM AND HAAS COMPANY This invention is concerned with vinyl chloride resin compositions.

Rigid vinyl chloride resinous compositions, i.e., compositions containing less than about "to 10 plasticizer, are characterized by a high degree of resistance to chemical attack, by outstanding solvent resistance, by good weathering resistance, and by a high strength to weight ratio and, consequently, have come into extensive use in the chemical processing and building and construction industries. Rigid vinyl chloride resin compositions are presently finding use in such applications as, for example, chemical processing equipment, pipes and pipe fittings, moldings, sheetings, building panels, etc. The processing of rigid resinous vinyl chloride products is not, however, accomplished without serious problems and difficulty. One problem is that the extrusion or milling temperatures are extremely close to the point at which the material will degrade and the utmost care must be exercised during extrusion or milling not to exceed the degradation temperature by any significant amount. Moreover, rigid vinyl chloride resins do not achieve melt flow as readily as other thermoplastics, but instead are somewhat more viscous during processing. This subjects the resins to a high shear which in turn creates additional heat, further tending to cause the material to degrade and break down.

Another problem present with rigid vinyl chloride compositions is that articles fabricated therefrom have relatively low service temperature. In praotice, the - 5 - practical service temperature of thermoplastio bodies is dictated by the softening temperature of the thermoplastic material, or by its heat distortion temperature, a term denoting the lowest temperature at which a material being tested, of specific dimensions, yields a specified distance under a specified loading. For example, the heat distortion temperature of polyvinyl chloride at 2β4 psi loading is about 75°C, a temperature which prevents the material from finding U3e in many applications; for example, in hot-fill food pack-aging applications, or in applications involving sterilization temperatures approximating that of boiling water. It is thus apparent that there is great need for an additive which will both aid the processing and heat distortion characteristics of rigid vinyl chloride resins.

In accordance with this invention, there is provided a vinyl chloride resin composition comprising a vinyl chloride polymer containing at least 80 by weight of vinyl chloride mers and, intimately admixed therewith in an amount to improve the processing characteristics and raise the heat dista& tion temperature of the vinyl chloride polymer, a non-rubbery thermoplastic copolymer containing methyl methacrylate mers and bicyclic methacrylate mers in a weight ratio from Jil to Is3 and 0 to 20 based on the total weight of methyl and bicyclic methacrylate mers of other compatible mers, said bicyclic methacrylate mers being of the formulas where X represents -CHg-, -CH(CH-,)-, or -C(CH-j)2-> Y represents methyl and n is zero or an integer.

Exemplary bicyclic methacrylate mers are those of isobomyl methacrylate, bornyl methacrylate, fenchyl methacry-late, isofenchyl methacrylate, norbornyl methacrylate or mixtures of such mers. The above-listed bioyclic methacrylates are known compounds and may be prepared in known fashion. For example, bornyl methacrylate may be prepared from «f-pinene and methacrylic acid and the isobomyl ester can be prepared from camphene and methacrylio acid in known manner.

Preferably, the bicyclic methacrylate mers are those of isobomyl methacrylate, bornyl methacrylate or a mixture of isobomyl and bornyl methacrylate mers having at least 10 weight percent isobomyl methacrylate mers. The non-rubbery copolymer may be prepared from a monomer mixture of 25 to 75 parts by weight of bicyclic methacrylate and 75 to 25 parts by weight of methyl methacrylate. In addition to methyl and bicyclic methacrylate mers, the non-rubbery copolymer may contain other "compatible mers" by which term is meant mers which do not nullify the improved processability and higher heat distortion temperature imparted by the methyl and bicyclic methacrylate mers. Compatible mers may be provided by the use of a minor amount, up to about lOfo by weight, of the combined weight of the bicyclic methacrylate and the methyl methacrylate, of a to alkyl acrylate and/or up to about 10 by weight of styrene or a ring-substituted styrene, "based on the combined weight of the bioyclic methacrylate and the methyl methacrylate. Preferred alkyl acrylates are ethyl and butyl acrylate and while styrene as opposed to a ring substituted styrene is preferred as another optional monomer. If a ring substituted styrene is used it may be an alkyl-substituted or halogen-substituted styrene, such as for example, methyl styrene, dimethyl styrene or meta-or ortho-ohlorostyrenes. Preferably, the bicyclic methacrylate mers are present in the range of about 35 to 65 parts by weight for each 65 to 35 P&r s by weight of methyl methacrylate mers. Preferred quantity ranges for the optional compatible mers mentioned above are (for every 100 parts of methyl and bicyclic methacrylate mers) 1 to 5 parts by weight for the alkyl acrylate such as ethyl or butyl acrylate, and 2 to 8 parts for the styrene or ring-substituted styrene.

The number average molecular weight of the copolymer additive as measured on a Mechrolab Osmometer Model $01 in monochlorobenzene through gel cellophane No.600 desirably ranges from about 10,000 to 1,500,000 and above, of which the ' .15,000 to 1,000,000 is preferred and of which the range range/15,000 to 50,000 is more preferred. The estimated intrinsic viscosity of the copolymer additive in ethylene dichloride, at 30°C, measured on an Ostwald viscometer preferably ranges from about 0.1 to 2.0 and above (dl/gr).

When ethyl acrylate, butyl acrylate and/or styrene are present, the copolymer composition varies as follows: 2 to 75 parts by weight of bicyclic methacrylate, 75 to 25 parts by weight of methyl methacrylate, 0 to 10 parts by weight of ethyl acrylate or butyl acrylate (for each 100 parts by weight and methyl methacrylate of bicyclic methacrylate^ and 0 to 10 parts by weight of styrene (for each 100 parts by weight of bicyclic methacrylate and methyl methacrylate).

The non-rubbery copolymer additives may be made by a variety of methods. One suitable method is by bulk .polymerization of the monomeric ingredients. In such a process a suitable amount of monomers is mixed with an addition polymerization catalyst, such as azobisisobutyronitrile, lauroyl peroxide, acetyl peroxide, ;t--butyl peracetate, jt-butyl hydroperoxide, etc., at a temperature sufficient to cause polymerization uch as in the range of 25° to 100°C. or higher. Another suitable method for making1 the non-rubbery copolymer is by an aqueous dispersion method. In this procedure the necessary copolymerizable monomers are polymerized as an emulsion in the presence of a suitable emulsifying agent such as sodium dodecyl-benzene sulfonate or sodium lauryl sulfate, and the resulting polymer is recovered by a suitable method. Commonly used molecular weight regulators such as the aliphatic mercaptans, for example, n-dodecyl mercaptan, may also be included in the polymerization mixture, if desired.

The compositions of the invention may also contain a rubbery, polymeric, impact modifier; such modifiers comprise a class of well-known and, generally, commerically available materials. They may be heterogeneous or homogenous in charac-ter, show increased impact strength as their amount is increased in the blend, and provide an Izod impact strength, at room temperature, of at least 1 ft/lb/inch of notch when used in the ratio of 15 parts by weight of modifier per 100 parts by weight of vinyl chloride resin. Typically, these modifiers are based on butadiene or butadiene-styrene copolymers. Representative of such modifiers are the methyl methacrylate-butadiene-styrene rubbery interpolymers disclosed and claimed in U.S. Patents 2,943,074 and 2,857,360 to Seymour S. Peuer. Other useful modifiers Include the acrylonitrlle-butadiene-styrene modifiers discloeed and claimed in U.S. Patents 2,753,322 and 2,808,387 to Parks et all chlorinated polyethylene, and the all acrylic impact modifiers disclosed in U.S. Patent 3,251,904 to L.C. Souder et al.

Processing aids such as impact modifiers of various' nature are known. U.S. Patent 3,267,179 discloses polyvinyl-chloride compositions containing an acrylic polymer which has been transesterified with 10-pinenyl methanol. The cyclic struct ure of the lO^pinenyl methanol differs greatly from the bicyclic methacrylates of the present invention in that the 10-pinenyl methanol has a ring unsaturatlon and is bridged at the 2- and 4-ring carbons, while the bicyclic methacrylates are bridged as the 2- and 5- carbon atoms of the ring.

Also the 10-pinenyl methanol contains a hydroxy alkyl group while the bicyclic methacrylates are esters. The utilisation of bicyclic methacrylates has resulted in the surprising improvement in heat distortion temperature characteri sties while maintaining impact resistant properties.

Rigid vinyl chloride compositions also frequently have poor or low impact-resistant properties. The rigid vinyl chloride compositions of the present invention, however, have good impe.ct-resistant properties over a wide range of temperatures, while at the same time. showing outstanding heat -distortion characteristics. This combination of toughness and improved heat distortion temperature iB due to the presence of the processing and heat distortion tempex-ature aid, namely, the non-rubbery copolymer based on a bicyolic methaorylate ester and the rubbery impact modifier. It is a surprising and unexpeoted result that the bicyclio methaorylate oopolymer processing aid improves heat distortion characteristics in a rubbery modified vinyl ohloride resinous system1, without at the same time signifioaiitly reducing impaot-resistant or tough-ness properties, as occurs in the oase cf prior art processing aids j the processing aids and the impact modifiers used in the present invention further combine to surprisingly reduce the flux time necessary to produoe a homogeneous fluxed or fused composition.

The rubbery impact modifier, when used, will, of course, be used in amounts sufficient to give some improvement in impact resistance. Generally, the impact modifier is used in an amount of about 10 to 100 parts by weight per 100 parts of vinyl chloride resin. Preferably, the impact modifier is used in an amount of about 20 to 80 parts per 100 parts of vinyl chloride resin.

The vinyl chloride resins useful in this invention include homopolymers of vinyl chloride as well as copolymers thereof with no more than 20 by weight of mers of one or more other ethylenically unsaturated compounds. Preferably, the vinyl chloride resin employed is a homopolymer of vinyl chloride, i. e. , lpolyvinyl chloride, since the most rigid compositions are ultimately obtainable therefrom. Vinyl chloride copolymers may be derived from comonomers such as vinyl alkanoates, e.g. vinyl acetate and vinyl propionatef vinylidene halides, e.g. vinylidene bromide, vinylidene chloride, vinylidene fluorochloride; unsaturated hydrocarbons, e.g. ethylene, propylene and isobutylene; allyl compounds, e.g. allyl acetate, allyl chloride and allyl ethyl ether.

The molecular weight of the vinyl chloride resins suitable for use in this invention can vary over a wide range. An indication of the molecular weight of those vinyl chloride resins particularly useful in this invention are those obtained by having a Fikentscher -value of about 45 and above, and preferably between 45 ad 90.

The vinyl chloride resin compositions of the invention contain the non-rubbery copolymer additive in an effective amount, i.e., in an amount sufficient to give some processing and heat distortion temperature improvement.

Generally, this amount is kept to a minimum, consistent with the "benefits desired. In practice, an amount in the range of about 5 to 50o by weight based upon the total combined weight of the non-rubbery additive and the vinyl chloride resin is generally adequate, although slightly greater or lesser amounts may be used. Preferably, the non-rubbery copolymer is used in the 25 to 50 by weight range. When an impact modifier is present, the non-rubbery copolymer is generally used in an amount from about 10 to 100 parts by weight per 100 parts by weight of vinyl chloride resin.

By using the non-rubbery oopolymer additive, there is formed a blend with vinyl chloride resins which is an extrudable, millable and workable plastic composition. A smooth, flexible polyvinyl chloride sheet is formed during processing by the use of the acrylic copolymer additive which upon cooling gives a rigid product which may be termed a homogeneous blend of the vinyl chloride resin and the copolymer. Here the descriptive term "homogeneous" refers to a composition in which the ingredients are intimately mixed or blended and are well dispersed so that the composition is uniform throughout. Usually the components in the compositions of the invention are essentially miscible and compatible so that the compositions have a high degree of clarity.

The compositions of the invention exhibit good thermal and light stability. Additionally, the compositions are usually essentially non-burning or self-extinguishing, a result which is surprising in view of the known effect in this regard of prior art acrylic modifiers.

In the vinyl chloride resin compositions of the invention there may be used in addition to the copolymer additional materials such as extenders, fillers, dyes, pigments, and stabilizers. The copolymers may be the sole processing aid employed, or they may be used in conjunction with other conventional materials.

The experiments present below show the preparation of illustrative non-rubbery copolymers and rubbery impact modifiers. All parts, ratios and percentages in the experiments, and elsewhere throughout this specification are by weight unless otherwise mentioned. The following abbreviations are used: IMA for methyl methacrylate, IBOMA for isobornyl methacrylate, and EA for ethyl acrylate.

Experiment 1 (a) There is charged to a suitable container a vacuum-degassed mixture of 1640 parts of methyl methacrylate, 2460 parts of isobornyl methacrylate, 1.44 parts of lauroyl peroxide, 0.70 part of acetyl peroxide, 0.62 part of t-butyl hydroperoxide, and 0.41 part of n-dodecyl meroaptan. The container is placed in a forced air oven and bulk polymerized at 66°C. for 15 hours, followed by a finish-off period for 8 hours, at increasing temperatures of from 80°C. to 130°C. The resultant slab is broken and ground into granules which are extracted with boiling hexane and dried at 60°C. to reduce the residual monomer level to less than 0.15$· The product is a 60/4O copolymer of isobornyl methacrylate/methyl-methacrylate and has a Gardner-Holdt viscosity of C (lOo in toluene) and an intrinsic viscosity of about 1.5 (in ethylene dichloride, dl/gr). (b) By adjustment of the monomer ratios and following the procedure of (a) above, there is obtained a copolymer of the following composition. 4θ/βΟ IBOMA/½!A with an intrinsic viscosity of 0.4 (in ethylene dichloride, dl/gr). (c) A mixture of 60 parts isobornyl methacrylate, 38 parts methyl methacrylate and 2 parts ethyl acrylate is polymerized in bulk, in the presence of a peroxide catalyst, for 12-16 hours at 66°C. followed by a finish-off period of 20-24 hours at 120°C. The 60/38/2 isobornyl methacrylate/methyl methacrylate/ethyl acrylate copolymer is a clear, transparent solid and has an intrinsic viscosity (in ethylene diohloride, dl/gr) of about 0.5-0.6. (d) By adjustment of the monomer ratios and following the procedure of (c) above, there is obtained a copolymer of the following compositions IB0 /MA/EA» 40/58/2. This copolymer has an intrinsic viscosity of 0.89 (in ethylene dichloride, dl/gr).

Experiment 2 To a suitable reactor equipped with stirrer, thermometer, nitrogen sweep, inlets for monomer addition and reflux condenser, there are charged 700 parts of water and a total of 5I8 parts of the following monomers; isobornyl methacrylate -10 parts, methyl methacrylate - I44 parts, ethyl acrylate - 6 parts, and styrene - 1Θ parts. Sodium lauryl sulfate emulei-fier (O. jfo) , a small amount of t-butyl meroaptan, and suffioient potassium persulfate initiator to initiate polymerization are added and the mass iB emulsion polymerized for a period of about 3 to hours. over a temperature range starting ai 65°C. and ending at about 95 to 98°C. The emulsion is then oooled, isolated by coagulation r spray dried. The produot is a 50/ 48/2/6 IBOMA A/EA styrene copolymer.

■ Experiment 3 (a) A rubbery impaot modifier is prepared aooording to teachings of U.S. Patent 2,943,074, more particularly by mixing po arts of methyl methacrylate with 50 parts (rubber solids basis) of a butadiene-styrene-copolymer latex ( the ratio of the butadiene to styrene in the latex being 70 to 30)i Benzoyl peroxide (0.05 part), sodium sulfoxylate formaldehyde (O.O25 part), and dodecyl meroaptan (0. 4, part) are added.

The mixture is agitated and polymerized for 24 hours at 60°C, coagulated, v/aohed arid dried under vaouum. (b ) Part (a) above is repeated except that there are used 71· parts of methyl methacrylate and 3.75 parts acrylonitrile with 25 parts (rubber solids basis) of a buta- w diene-styrene oopolymer latex.

In the practice of this invention, the vinyl chloride resin and the non-rubbery copolymer and, if used, the impact modifier can be blended in any convenient manner and order. A suitable procedure, for instance, involves manually or mechan-ically admixing the ingredients in proportions as hereinabove described in an unheated container and adding the dry-blended mixture to an equal speed or differential roll speed two roll mill maintained at a temperature of about 350°P. to 400°P.

Other methods of processing are equally effective. For example, the ingredient can be added to a hot Banbury mill for fluxing and homogenizing and then fed to a hot roll mill or calender for a sheeting operation.

The following ingredients were dry-blended for a few minutes; polyvinyl chloride (hereinafter abbreviated PVC), 100r-X-parts; copolymer processing additive prepared according to Experiment 1 or 2, X parts; and 3 parts of barium-cadmium laurate stabilizer. After dry-blending, the samples were milled on a two-roll mill at 365° E. for 10 minutes after flux. Processing properties were noted and heat distortion temperature (HDT), reported in 0 C, was measured in accordance with ASTM ϋ-648-56 (1961 ) .

Results are set out in Table I T A B L E I Milling Properties Composition HDT,°C. Flux Rolling Re- Vacuum (26 psi) Time Bank lease Formability (Min) (a) PVC (no copolymer additive) 75 1 Fi.-or Exc. Poor (b) Wo (IBOMA/MMA 60 AO copol.); ¾ PVC 79 2 Fair Exc. Fair (c) 30$ (IBOMA/MMA 60 O copol.); 70¾ PVC 85 5-1/2 Good+ Good* Good (d) 50¾ (IBOMA MMA 60AO copol.); 5C$ PVC 98-100 8-1/2 Good+ Good Exc. (e) 5C# (IBOMA/MMA/EA 6Ο/38/2 copol.) 5C$ PVC 100-102 8-1/2 Exc. Exc. (f) 5C$ (IBOMA/MMA/EA itO/58/2 copol.); 50^ PVC 96 5 Exc. Exc. (g) $ (IBOMA/MMA ¼·0/6θ copol.); 0$ PVC 95 3-1/2 Exc. Exc. (h) 50?o copolymer of Essefflple- -Experiment 2 0$ PVC 95 Exc. Exc. Exc.

Exc. = Excellent Copol. = Copolymer The excellent processing and heat distortion resisting characteristics of the acrylic modified vinyl chloride resin composition of the present invention can be observed by inspection of Table 1 above. It can be seen that the unmodified BaCd stabilized PVC has a heat distortion temperature of only 75° C. at 26k psi and generally poor processing and working properties; an appreciable improvement in these properties is shown in the composition containing 10$ of the bicyclic methacrylate-methyl methacrylate modifier additive, wherein the bicyclic methacrylate is isobornyl methacrylate, with the trend dramatically increasing at higher levels of copolymer additive; note, for example, the rise in heat distortion temperature from 75° C. to about 100° C. at the 50 modifier level.

IMPACT MODIFIED VINYL CHLORIDE RESIN COMPOSITIONS A series of modified vinyl chloride resin compositions identified in Table II were prepared by dry blending for a few minutes polyvinyl chloride (hereinafter abbreviated PVC), a rubbery impact modifier and a non-rubbery bicyclic methacrylate copolymer. In each case, the compositions were stabilized with 3 parts of barium-cadmium laurate stabilizer. After dry blending, the specimens were milled on a two-roll mill at 3 5° F. for 10 minutes after flux. Processing properties, Izod impact properties and heat distortion temperature (KDT) are noted below in Table III. (Izod impact determined according to ASTM D 256-56; and HDT, repeated in °C, is measured in accordance with ASTM D 6^8-56 (196 ) .

A B L E II Specimen Identification Composition Unmodified PVC PVC 85 parts Rubbery Impact Modifier 15 " of Experiment 3( above 100' PVC 5 parts Rubbery Impact Modifier of Experiment (lQ above 15 " Bicyclic Methacrylate Copolymer of Experiment l(a) above jM- " 100 PVC 80 parts Rubbery Impact Modifier of Experiment 3(¾Q above 20 " & 100 PVC 6 parts Rubbery Impact Modifier of Experiment j5(¾) above 20 parts Bicyclic Methacrylate Copolymer of Experiment 1(a) above 2k " 100 PVC 75 parts Rubbery Impact Modifier of Experiment 3-( above 25 " s 100 PVC ½ parts Rubbery Impact Modifier of Experiment 3(¾^. above 25 " Bicyclic Methacrylate Copolymer of Experiment 1(a) above 30 " 100 PVC 5 parts Rubbery Impact Modifier of. Experiment 3( Q above 25 " Bicyclic Methacrylate Copolymer of Experiment 2 above 30 " PVC Rubbery Impact Modifier of Experiment 3(T¾, above Conventional Acrylic Processing Aid (MMA/EA) 90/10) Copolymer 100 A B L E III Specimen Properties HDT ° C. Izod Impact (264 psi) ft.-lbs./inch of notch Vacuum (room temperature) Forming A 75 0.5 - 0.7 Poor B 75 24.1 Poor C 85 2 Exc.

D 75 27 Poor E 84 11 .2 Exc.

F 74 20 Poor G 86 6.2 Exc.

H 88 7.1 Exc.

I 74 __ Exc. = Excellent The excellent processing, heat distortion and impact resistant properties of the vinyl chloride resin compositions of the present invention can be observed by inspection of Table III above. It can be seen that the unmodified Ba-Cd stabilized PVC has a heat distortion temperature of only 75° C. at 264 psi, very poor impact properties and poor processing and working properties as indicated by its inability to be vacuum-formed. Significant increase in HDT and in working properties is shown by specimens C, E, G, and H, without at the same time significantly sacrificing impact properties or toughness. Specimen I shows the result of using a conventional acrylic processing aid; i.e., note the decrease in HDT.

While the particular working examples above illustrate the invention wherein the bicyclic methacrylate is isobornyl methacrylate and the rubbery impact modifier is based on butadiene, styrene and methyl methacrylate, a similar improvement is noted in the properties of vinyl chloride resins when the bicyclic methacry^ate in the non-rubbery copolymer is any one of those other monomers listed earlier in this specification. Typical other non-rubbery copolymers which may be used include, for example, a copolymer of 50 parts bornyl methacrylate and 50 parts methyl methacrylate; a. copolymer of o parts methyl methacrylate and 60 parts of a mixture of 10-90 parts by weight of isobornyl methacrylate and 90-10 parts by weight of bornyl methacrylate; a copolymer of 60 parts norbornyl methacrylate and parts methyl methacrylate; a copolymer of kO parts fenchyl methacrylate and 60 parts methyl methacrylate; a copolymer of ^O parts isobornyl methacrylate, 60 parts methyl methacrylate and 3 parts butyl aerylate; and a copolymer of ) parts isobornyl methacrylate, 60 parts methyl methacrylate, 2 parts ethyl aerylate and 8 parts styrcoe. Typical additional- impact modifiers which may be used include those based on acrylonitrile , butadiene and styrene; on methyl methacrylate, acrylonitrile, butadiene and styrene; such as that of Experiment "b 3¾jP) above, or the all acrylic impact modifiers of U.S. Patent 3, 251 ,904. ) The thermoplastic vinyl chloride resin compositions of this invention may be calendered to form smooth sheets or formed into conventionally sized molding powders. The compositions of this invention offer many advantages over standard molding powders based on vinyl chloride. For example, the resistance to defor-mation at high temperatures under load is substantially improved over that of said molding powders. Also most molding powders based on vinyl chloride are difficult to mold into useful shapes in that the flow under pressure at in ection molding temperatures is poor. This defect in molding processability may cause internal defects in the molded parts, surface defects on the parts, degradation of the molding powder due tc over-heating, incomplete fill of complicated parts, increased gate sizes causing substantial waste, - - other molding difficulties, etc. On the other hand, the contritions of this invention offer outstanding molding and processing characteristics. This may be demonstrated by the fact that the flow characteristics of the composition of this invention at injection molding temperatures is better than either the polyvinyl chloride or the acrylic copolymer modifier containing the bicyclic meth-acrylate. For example, the composition of 37·5 parts of the acrylic copolymer modifier as prepared in Experiment I (b) with an estimated intrinsic viscosity in ethylene dichloride of 0.21 (dl/gr) and 62.5 parts polyvinyl chloride gives a Vicat softening temperature of 9'+ to 95° C. at 10 mils deflection, a deformation temperature under load of 850 C. at 264 psi (ASTM D-648-56-1961 ) , and viscosity of approximately 4,000 to ,300 poises at 400° F. / 1,000 seconds ~ . The viscosities at 400 F./1,000 seconds " of the polyvinyl chloride and the acrylic copolymer modifier tested alone are approximately 4,800 to 4,900 and 9,800 to 9,900 poises, respectively. Therefore, this composition offers improved service temperatures as well as better processing characteristics as evidenced by the better flow at molding temperatures and pressures. Further, such composition offers significant reduction of mold defects, warping, surface blushing, and improvements in mold filling and other processing characteristics.

The compositions of this invention may be fabricated into pipes or pipe sections, building panels, home siding (replacing conventional sidings such as aluminum or asbestos), window components, including window sash and rails , etc. , by such diverse forming or molding operations as extrusion, injection molding, blow molding, rotational molding, etc. The improved resistance to deformation at elevated temperatures allows fluids at higher temperatures to be used in plastic pipe made from the composition of this invention. Further, building panels and window components made from the composition of this invention offer outstanding - -resistance to degradation of appearance and physcial properties upon outdoor exposure and exposure to various elements.

Claims (12)

What we claim is :

1. » A vinyl chloride resin composition comprising a vinyl chloride polymer containing at least 8C# by weight of vinyl chloride mers and, intimately admixed therewith in an amount to improve the processing characteristics and raise the heat disybortion te4fe«%iett- temperature of the vinyl chloride polymer, a non-rubbery thermoplastic copolymer containing methyl methacrylate mers and bicyclic methacrylate mers in a weight ratio from 3*1 to 1:3 and 0 to 2C#, based on the total weight of methyl and bicyclic methacrylate mers of other compatible mers, said bicyclic methacrylate mers being of the formula : 0 CH-. where X represents -CI^-, -CH(CR-J-, or -CCCE..^-, Y represents methyl and n is zero or an integer.

2. A composition according to Claim 1 which, based on the combined weight of vinyl chloride polymer and non-rubbery copolymer, contains 5 - by weight of the non-rubbery copolymer.

3. A composition according to Claim 2 which, based on the combined weight of vinyl chloride polymer and non-rubbery copolymer, contains 25 to 5C$ of the non-rubbery copolymer.

4. , A composition according to any one of the preceding claims in which the vinyl chloride polymer is a homopolymer of vinyl chloride.

5. A composition according to any one of the preceding claims wherein the bicyclic methacrylate mers in the non-rubbery copolymer are those of isobornyl methacrylate.

6. A composition according to any one of the preceding claims which also contains a rubbery impact modifier in an amount of about 10 to 100 parts by weight per 100 parts of vinyl chloride polymer.

7. A composition according to Claim 6, wherein the component impact modifier is a butadiene/styrene copolymer.

8. A composition according to any one of the preceding claims, wherein the non-rubbery copolymer either consists entirely of methyl methacrylate and said bicyclic methacrylate mers or contains, as said compatible mers, up to 10$ by weight, based on the total weight of methyl methacrylate and bicyplic methacrylate mers, of a C^-C^ alkyl acrylate and/or up to 10$ by weight, based on the total weight of methyl methacrylate mers and bicyclic methacrylate mers,^of styrene or a ring substituted styrene.

9. A composition according to Claim 8, wherein the non-rubbery copolymer contains 1-5$ by weight of ethyl acrylate and/or butyl acrylate mers based on the combined weight of methyl methacrylate and bicyclic methacrylate mers.

10. A composition according to Claim 8, wherein the non-rubbery copolymer contains -8$ by weight of styrene based on the combined weight of methyl methacrylate and bicyclic methacrylate mers.

11. A composition according to any one of the preceding claims wherein the number average molecular weight, measured as hereinbefore described, of the non-rubbery copolymer is from 10,000 to 1 ,500,000.

12. A composition according to Claim 11 , wherein said molecular weight is from 15,000 to 1,000,000. 13· A composition according to Claim 1 1 , wherein said molecular weight is from 15 , 000 to 50, 000 , 1*f. A composition according to any one of the preceding claims wherein the vinyl chloride polymer has a Fikentscher K- value between and 90. For the Applicants DR. R-!IAD CCHN AND PARTNERS By' /