Aqueous polymer blend composition

• US 7,105,593 B2
• Filed: 11/24/2004
• Issued: 09/12/2006
• Est. Priority Date: 06/04/2002
• Status: Expired due to Term

• Current Assignee: Rohm and Haas Company (Dow, Inc.)
• Original Assignee: Rohm and Haas Company (Dow, Inc.)
• Inventors: Matthews, Mary Anne Regina, Solomon, Robert David
• Primary Examiner(s): NAKARANI, DHIRAJLAL S
• Application Number:
  US10/996,775
• Publication Number:
  US 20050106402A1
• Time in Patent Office: 657 Days
• Field of Search: 524/457, 524/458, 524/460, 524/601
• US Class Current: 524/457
• CPC Class Codes: C04B 2103/0065 Polymers characterised by their glass transition temperature (Tg)
• CPC Class Codes: C04B 28/02 containing hydraulic cements other than calcium sulfates
• CPC Class Codes: C04B 41/009 characterised by the material treated
• CPC Class Codes: C04B 41/4578 Coating or impregnating of green ceramics or unset concrete
• CPC Class Codes: C04B 41/483 Polyacrylates
• CPC Class Codes: C04B 41/502 Water
• CPC Class Codes: C04B 41/63 Macromolecular compounds
• CPC Class Codes: C09D 201/00 Coating compositions based on unspecified macromolecular compounds
• CPC Class Codes: C09D 5/02 Emulsion paints including aerosols
• CPC Class Codes: Y10T 428/2998 including synthetic resin or polymer
• CPC Class Codes: Y10T 428/31667 Next to addition polymer from unsaturated monomers, or aldehyde or ketone condensation product
• CPC Class Codes: Y10T 428/31681 Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.]

Abstract

An aqueous polymer blend composition containing particles of a first polymer and particles of a second polymer with preferred molecular weight ranges is provided. Coatings prepared from the aqueous polymer blend composition may be employed as coatings which have water whitening resistance and provide resistance to efflorescence to cementitious substrates, such as roof tiles. A method of preparing a coated cementitious substrate with the aqueous polymer blend composition and an article containing the coated cementitious substrate are also provided.

Claims

1. An aqueous polymer blend composition comprising:

a) particles of a first polymer; and

b) particles of a second polymer;

wherein said first polymer has a weight average molecular weight of 250,000 or greater;

wherein said second polymer has a weight average molecular weight of 150,000 or less;

wherein said particles of said second polymer have an average diameter in the range of 20 nm to 350 nm;

wherein the glass transition temperature of said first polymer and the glass transition temperature of said second polymer have substantially the same value;

wherein the weight ratio of said first polymer to said second polymer is in the range of 1;

3 to 3;

1; and

wherein the average glass transition temperature of said first polymer and said second polymer is in the range of 15°

C. to 50°

C. and

wherein said composition contains less than 2 weight percent surfactant.

2. The aqueous polymer blend composition according to claim 1 wherein the difference in said glass transition temperature of said first polymer and said glass transition temperature of said second polymer is 5°

C. or less.

3. The aqueous polymer blend composition according to claim 1 wherein said particles of said first polymer have an average diameter in the range of 60 nm to 170 nm.

4. The aqueous polymer blend composition according to claim 3 wherein said particles of said second polymer have an average diameter in the range of 60 nm to 170 nm.