Acrylic polymer emulsion

• US 4,385,152 A
• Filed: 10/13/1981
• Issued: 05/24/1983
• Est. Priority Date: 11/06/1979
• Status: Expired due to Term

• Current Assignee: Albright & Wilson Limited 610 St Kilda Road Membourne Victoria Australia
• Original Assignee: Albright & Wilson Limited 610 St Kilda Road Membourne Victoria Australia
• Inventors: Boyack, Robert M., Cooke, Perry J., Henshaw, Bruce C.
• Primary Examiner(s): Michl, Paul R.
• Application Number:
  US06/311,054
• Time in Patent Office: 588 Days
• Field of Search: 260/29.6 RB, 260/29.6 RW, 260/29.6 WB, 525/78, 525/221, 525/301, 525/902, 524/460
• US Class Current: 524/460
• CPC Class Codes: C08F 2/22 Emulsion polymerisation
• CPC Class Codes: C08F 265/06 Polymerisation of acrylate or methacrylate esters on to polymers thereof
• 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 33/06 of esters containing only carbon, hydrogen and oxygen, which oxygen atoms are present only as part of the carboxyl radical
• 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

Aqueous acrylic polymer emulsions containing as a first polymeric component a core-shell polymer having a core formed from one or more monomers selected from styrene, vinyl acetate, vinyl toluene and acrylic or methacrylic acid esters of alcohols of 1 to 4 carbon atoms and a shell formed of the above monomers in conjunction with one or more monomers selected from acrylic acid or methacrylic acid esters of alcohols of 1 to 8 carbon atoms and a minor amount of acrylic or methacrylic acid and as a second polymeric component a polymer composed of a major amount of one or more monomers selected from styrene, vinyl acetate, vinyl toluene and acrylic or methacrylic acid esters of alcohols of 1 to 4 carbon atoms and a minor portion of one or more acrylic acid esters of alcohols of 1 to 8 carbon atoms with acrylic and/or methacrylic acid.

Claims

1. A cementitious coating composition which forms a film at or below room temperature and which film has low dirt pickup properties comprising an aqueous film forming emulsion consisting essentially of

(a) a polymer formed by first reacting a minor portion of

(i) a monomer mixture comprising one or more monomers selected from acrylic or methacrylic acid esters of alcohols of 1 to 4 carbon atoms in conjunction with a minor amount of one or more monomers selected from divinyl benzene and acrylic or methacrylic acid esters of alcohols of 1 to 8 carbon atoms which monomer mixture yields a polymer having glass transition temperatures between 50°

and 150°

C. and subsequently adding to said first reaction mixture a major portion of

(ii) a monomer mixture comprising a major amount of one of more monomers selected from acrylic or methacrylic acid esters of alcohols of 1 to 4 carbon atoms and one or more monomers selected from acrylic acid or methacrylic acid esters of alcohols of 1 to 8 carbon atoms with a minor amount of acrylic acid and/or methacrylic acid which monomer mixture yields a polymer having a glass transition temperature in the range of -10°

to 10°

C.;

in admixture with

(b) a polymer formed by reacting a mixture of a major amount of one or more monomers selected from acrylic or methacrylic acid esters of alcohols of 1 to 4 carbon atoms and a minor portion of one or more acrylic acid esters of alcohols of 1 to 8 carbon atoms with acrylic and/or methacrylic acid, wherein the weight ratio of a (ii) to a (i) is within the range of 67;

33 to 95;

5 and the ratio of (a) to (b) is within the range of 3;

1 to 1;

2.

2. An emulsion according to claim 1 wherein polymer (a) comprises (i) a major amount of methyl methacrylate and a minor amount of ethylene glycol dimethacrylate and (ii) a major amount of methyl methacrylate and butylacrylate and a minor amount of methacrylic acid and polymer (b) comprises a major amount of methyl methacrylate and a minor amount of butylacrylate and methacrylic acid.

3. An emulsion according to claim 1 wherein polymer (a) and polymer (b) are present in equal weight proportions.

4. A method of treating cementitious substrates which comprises applying to wet uncured cementitious substrates a coating of an emulsion as defined in claim 1 and thereafter curing said coated substrate.