Polymer composition

• US 7,101,921 B2
• Filed: 10/11/2002
• Issued: 09/05/2006
• Est. Priority Date: 10/17/2001
• Status: Active Grant

• Current Assignee: Rohm and Haas Company (Dow, Inc.)
• Original Assignee: Rohm and Haas Company (Dow, Inc.)
• Inventors: Edwards, Steven Scott, Marks, Allen Philip, Maurice, Alvin Michael, Gebhard, Matthew Stewart
• Primary Examiner(s): EGWIM, KELECHI CHIDI
• Application Number:
  US10/269,402
• Publication Number:
  US 20030088014A1
• Time in Patent Office: 1,425 Days
• Field of Search: 523/201, 524/458, 524/522, 524/523
• US Class Current: 523/201
• CPC Class Codes: C08F 265/06 Polymerisation of acrylate or methacrylate esters on to polymers thereof
• CPC Class Codes: C08F 291/00 Macromolecular compounds obtained by polymerising monomers on to macromolecular compounds according to more than one of the groups C08F251/00 - C08F289/00
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• 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: C08L 55/005 Homopolymers or copolymers obtained by polymerisation of macromolecular compounds terminated by a carbon-to-carbon double bond
• CPC Class Codes: C09D 133/06 of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
• CPC Class Codes: C09D 151/003 grafted on to macromolecular compounds obtained by reactions only involving unsaturated carbon-to-carbon bonds C09D151/04, C09D151/06 take precedence

Abstract

A polymer composition including polymer particles containing a first polymer and a second polymer is disclosed. The first polymer has a crosslinked core and has a glass transition temperature in the range of −30° C. to 100° C. The second polymer containing select crosslinking groups and has a glass transition temperature in the range of −10° C. to less than 18° C. A process to prepare the polymer composition is provided. Also provided are a coated article containing a coating prepared from the polymer composition and a method of preparing the coated article. The polymer composition has good low temperature film formation and provides a film with an acceptable level of hardness.

Claims

1. A polymer composition comprising polymer particles dispersed in an aqueous medium, wherein said polymer particles comprise, based on the weight of said polymer particles:

a) from 10 to 70 weight % first polymer; and

b) from 30 to 90 weight % second polymer;

wherein said first polymer has a Tg in the range of 15°

C. to less than 30°

C. and comprises as polymerized units, based on the weight of said first polymer, from;

i) 85 to 99.9 weight % comonomer,

ii) 0 to 5 weight % anionic monomer, and

iii) 0.1 to 10 weight % multiethylenically unsaturated monomer,

wherein said second polymer has a Tg in the range of −

5°

C. to 15°

C. and comprises as polymerized units, based on the weight of said second polymer, from;

i) 70 to 99 weight % comonomer,

ii) 0 to 10 weight % anionic monomer, and

iii) 1 to 20 weight % crosslinking monomer;

and wherein the polymer composition comprises from 0.01 to less than 2 weight % volatile organic compounds, based on the weight of said polymer composition, and the polymer composition has degree of cracking of at least 6 and a hardness value of at least 65 seconds.

2. The polymer composition according to claim 1 wherein said crosslinking monomer is selected from the group consisting of acetoacetoxyethyl (meth)acrylate, acetoacetoxypropyl (meth)acrylate, acetacetoxybutyl (meth)acrylate, 2,3-di(acetoacetoxy)propyl (meth)acrylate, allyl acetoacetate, and vinyl acetoacetate.

3. The polymer composition according to claim 1 wherein said polymer composition has a pigment volume concentration in the range of 0 to 25.

4. The polymer composition according to claim 1 further comprising 0 to 20 weight % cosolvent based on the weight of said polymer composition.