# US 4,393,172 A · High-notched-impact core-shell polymers having improved weather resistance

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- Number: US 4,393,172 A
- Document ID: US4393172A
- Status: Granted
- Kind: A
- Application number: 06/309,569
- Filed: 1981-10-08
- Granted: 1983-07-12
- Earliest claimed: 1980-02-23
- Assignees: Bayer Aktiengesellschaft
- Inventors: Christian Lindner; Karl-Heinz Ott; Alfred Pischtschan
- Web page: https://patentgrep.com/patent/US4393172A

## CPC

- C08F 279/02: on to polymers of conjugated dienes
- Y10S 525/902: Core-shell
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

A particulate graft polymer comprising (a) a core formed by a crosslinked homopolymer of a conjugated diene or a copolymer thereof with up to 10% by weight of styrene or acrylonitrile; (b) a first shell formed by a crosslinked homopolymer of an acrylic acid alkyl ester or a copolymer thereof with up to 30% by weight of vinyl monomers; (c) a second shell formed by a polymer of resin-forming monomers, a process for manufacturing these graft polymers by means of a multi-stage emulsion polymerization, and their application as molding compositions, optionally together with rigid thermoplastic resins.

## Claims

### Claim 1

Particulate graft polymer comprising
(a) a core which is a crosslinked homopolymer of a conjugated diene or a copolymer thereof with up to 10% by weight of copolymerized styrene or acrylonitrile and having a gel content of more than 50%,
(b) a first shell which is a crosslinked rubber formed by polymerizing a monomer mixture consisting of at least one acrylic acid alkyl ester having 1 to 8 carbon atoms in the alkyl moiety and 0.05 to 10% by weight, based on the weight of (b), of a crosslinking polyfunctional monomer and
(c) a second shell of a polymer of at least one resin-forming monomer selected from the group consisting of .alpha.-methyl styrene, styrene, acrylonitrile and methyl methacrylate.

### Claim 2 (depends on 1)

Particulate graft polymer according to claim 1, wherein the weight ratio of (a) and (b) is 0.1 to 99.9 to 80 to 20.

### Claim 3 (depends on 1)

Particulate graft polymer according to claim 1, wherein the core (a) is polybutadiene.

### Claim 4 (depends on 1)

Particulate graft polymer according to claim 1, wherein (c) is a copolymer of styrene and acrylonitrile.

### Claim 5 (depends on 1)

A moulding composition comprising a particulate graft polymer according to claim 1 and a rigid thermoplastic resin.

### Claim 6 (depends on 5)

A moulding composition as claimed in claim 5, wherein the rigid thermoplastic resin is a styrene/acrylonitrile copolymer.