# US 4,395,500 A · Protective colloid-free plastics dispersion having a bimodal particle size distribution

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- Number: US 4,395,500 A
- Document ID: US4395500A
- Status: Granted
- Kind: A
- Application number: 06/306,875
- Filed: 1981-09-29
- Granted: 1983-07-26
- Earliest claimed: 1980-10-01
- Assignees: Hoechst Aktiengesellschaft
- Inventors: Gernot Lohr; Rolf Reinecke
- Web page: https://patentgrep.com/patent/US4395500A

## CPC

- C09D 5/02: Emulsion paints {including aerosols}
- C08J 3/03: in aqueous media
- C09D 5/34: Filling pastes (materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12)
- C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D)
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)

## Abstract

A protective colloid-free plastics dispersion yielding after drying a polymer film which under the influence of moisture has no or little tendency to whitening contains polymer particles having a bimodal size distribution, that is, on the one hand relatively coarse particles and on the other hand relatively fine particles. The polymer component consists of at least 10 weight % of particles having an average diameter of less than 0.2 .mu.m and of 90 weight % at most of particles having an average diameter of more than 0.25 .mu.m, and the ratio of average grain size of coarse to fine polymer is at least 2:1. The plastics dispersion is suitable especially as binder dispersion in plasters and gloss paints.

## Claims

### Claim 1

A protective colloid free plastics aqueous dispersion having a bimodal particle size distribution, wherein the plastics portion consists of from 60 to 80 weight % of a coarse-grain polymer having an average particle size of more than 0.25 .mu.m and from 40 to 20 weight % of a fine-grain polymer having an average particle size of below 0.2 .mu.m, the average particle size ratio of said coarse-grain polymer to said fine-grain polymer being at least 2:1, and wherein the coarse-grain polymer and the fine-grain polymer are copolymers consisting essentially of styrene and/or esters of acrylic acid or esters of methacrylic acid and, optionally, unsaturated acids or amides of unsaturated acids in an amount of below 10 weight percent (relative to the total monomers) and, optionally, monomers capable of being cross-linked in an amount of up to 5 weight percent (relative to the total of monomers).

### Claim 2 (depends on 1)

Plastics bound plaster or gloss paint containing as binder the plastics dispersion of claim 1.

### Claim 3 (depends on 1)

Unpigmented coating containing the plastics dispersion of claim 1.