Claims
- 1. A process for the manufacture of a polyvinyl chloride composition having an improved heat distortion temperature, said process comprising blending at a temperature set within a range of about 150.degree.-220.degree. C.
- (A) 50-95 parts by weight of polyvinyl chloride with
- (B) a complementary amount, the total adding to 100 parts by weight, of a polymer blend, comprising a matrix and a dispersed phase, consisting essentially of about
- (i) 30-85 weight percent of a dispersed phase of an imidized acrylic resin having a glass transition temperature above 150.degree. C., as determined according to ASTM standard D3418, taking the midpoint value, and a flexural modulus of at least 690 kPa wherein at least 20% of ester groups originally present in the resin are imidized to units of the following formula (1): ##STR2## wherein each one of R1, R2, and R3 independently is hydrogen or a C.sub.1 -C.sub.20 alkyl, cycloalkyl, or aryl group, said imidized acrylic resin further containing 0-50 weight percent of a copolymerized ethylenically tinsaturated additional monomer and being substantially free of functional groups capable causing degradation of polyvinyl chloride within the temperature range of about 150.degree.-220.degree. C.; said resin being melt-processable at a temperature within the range of about 200.degree. to 300.degree. C.;
- (ii) 15-70 weight percent of a matrix of a third polymer, which is melt processable throughout the temperature range of about 150.degree. to 300.degree. C. and is substantially free of functional groups capable of causing degradation of imidized acrylic resin within the temperature range of about 200.degree.-300.degree. C. and of polyvinyl chloride within the temperature range of about 150.degree.-220.degree. C.; said polymer blend (B) of imidized acrylic resin (i) with third polymer (ii) being melt-processable below about 220.degree. C.;
- blending of polyvinyl chloride with polymer blend (B) being conducted under such temperature and shear conditions that blend (B) becomes dispersed in polyvinyl chloride; and substantially all of the imidized acrylic resin (i) forms compatible, single-phase composition with polyvinyl chloride.
- 2. A process of claim 1 wherein each one of R1, R2, and R3 is methyl.
- 3. A process of claim 1 wherein and the degree of imidization of the resin is about 60-100%.
- 4. A process of claim 3 wherein the glass transition temperature of imidized acrylic resin (i) is about 155.degree.-165.degree. C., as determined according to ASTM standard D3418, taking the midpoint value.
- 5. A process of claim 1 wherein the temperature at which polyvinyl chloride is blended with blend (B) is about 160.degree.-210.degree. C.
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part, of application Ser. No. 07/941,692 filed Sep. 8, 1992, now abandoned, which is a continuation-in-part of my application Ser. No. 07/665,642 filed Mar. 6, 1991.
US Referenced Citations (8)
Non-Patent Literature Citations (2)
Entry |
Paraloid.RTM. HT-510.TM. "Heat Distortion Temperature Modifier for Clear and Opaque PVC" Rohm & Haas Jan. 1988. |
Paraloid.RTM. EXL.TM. "EXL.TM.-4000 Additives" Rohm & Haas Jun. 1990. |
Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
941692 |
Sep 1992 |
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Parent |
665642 |
Mar 1991 |
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