Material for modifying impact resistance

• US 5,270,397 A
• Filed: 06/25/1992
• Issued: 12/14/1993
• Est. Priority Date: 06/29/1991
• Status: Expired due to Term

• Current Assignee: Evonik Rã¶Hm GmbH (Rag-Stiftung)
• Original Assignee: ROHM Co., Ltd.
• Inventors: Suefke, Thomas, Mueller, Reiner, Rhein, Thomas
• Primary Examiner(s): JAGANNATHAN, VASUDEVAN SALEM
• Application Number:
  US07/904,183
• Time in Patent Office: 537 Days
• Field of Search: 525/304, 525/309, 525/902, 525/281
• US Class Current: 525/309
• CPC Class Codes: C08F 285/00 Macromolecular compounds obtained by polymerising monomers on to preformed graft polymers
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 2666/24 Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof
• CPC Class Codes: C08L 33/12 Homopolymers or copolymers of methyl methacrylate
• CPC Class Codes: C08L 51/003 grafted on to macromolecular compounds obtained by reactions only involving unsaturated carbon-to-carbon bonds C08L51/04, C08L51/06 take precedence
• CPC Class Codes: Y10S 525/902 Core-shell

Abstract

An emulsion polymer having at least three phases, adaptable as an agent for modifying the impact resistance of rigid thermoplastic synthetic resins such as polymethyl methacrylate, and consisting of

A) a rigid core phase of a crosslinked homo- or copolymer,

B) an elastomer phase, prepared in the presence of the core material and having a glass transition temperature not above -10° C., comprising a crosslinked resin which includes an arylalkyl acrylate or arylalkyl methacrylate, and

C) a rigid shell phase, prepared in the presence of the elastomer phase, having a glass transition temperature of at least 50° C.

Claims

1. An agent adaptable to modifying the impact resistance of thermoplastic synthetic resins, which agent is an emulsion polymer having at least three phases and containing

A) a rigid core phase of a homopolymer or copolymer of an ethylenically unsaturated free-radically polymerizable monomer or monomers;

B) an elastomer phase, prepared in the presence of the core phase and having a glass transition temperature not above -10°

C., consisting essentially of

a) an alkyl ester of acrylic acid having 1 to 8 carbons atoms in the alkyl portion,

b)0.5 to 5 percent by weight of at least one crosslinking comonomer having two or more polymerizable double bonds in the molecule, and

c) an alkylaryl acrylate or alkylaryl methacrylate, and

C) a rigid shell phase, prepared in the presence of the elastomer phase and having a glass transition temperature of at least 50°

C., of an homo- or copolymer of ethylenically unsaturated free-radically polymerizable monomers.

2. An agent for modifying impact resistance as in claim 1 wherein said elastomer phase is synthesized from

a) 85 to 50 percent by weight of an alkyl ester of acrylic acid having 1 to 8 carbon atoms in the alkyl portion,

b) 0.5 to 5 percent by weight of said crosslinking comonomer or comonomers, and

c) 15 to 45 percent by weight of said arylalkyl acrylate or methacrylate.

3. An agent for modifying impact resistance as in claim 1 wherein at least one of said rigid core phase and said rigid shell phase consists entirely of polymethyl methacrylate or of a copolymer containing at least 50 percent by weight of methyl methacrylate.

4. An agent for modifying impact resistance as in claim 1 which contains, based on the emulsion polymer,

A) 5 to 40 percent by weight of said rigid core phase,

B) 25 to 75 percent by weight of said elastomer phase, and

C) 20 to 60 percent by weight of said rigid shell phase.