Water borne pressure sensitive adhesive compositions derived from copolymers of higher vinyl esters

• US 6,084,024 A
• Filed: 11/12/1996
• Issued: 07/04/2000
• Est. Priority Date: 11/12/1996
• Status: Expired due to Term

• Current Assignee: Ashland Licensing and Intellectual Property Llc
• Original Assignee: Air Products and Chemicals Incorporated (Linde Plc)
• Inventors: Mao, Chung-Ling, Kem, Kenneth Merle
• Primary Examiner(s): REDDICK, MARIE L
• Application Number:
  US08/748,216
• Time in Patent Office: 1,330 Days
• Field of Search: 524/560, 524/561, 524/562, 524/564, 524/832, 524/833, 524/556, 526/328, 526/329.5, 526/328.5
• US Class Current: 524/556
• CPC Class Codes: C08F 218/10 of monocarboxylic acids containing three or more carbon atoms
• CPC Class Codes: C08F 220/06 Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof
• CPC Class Codes: C08F 220/12 of monohydric alcohols or phenols
• CPC Class Codes: C08F 220/14 Methyl esters , e.g. methyl (meth)acrylate
• CPC Class Codes: C08F 220/1808 C8-(meth)acrylate, e.g. isooctyl (meth)acrylate or 2-ethylhexyl (meth)acrylate
• CPC Class Codes: C09J 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: C09J 133/062 Copolymers with monomers not covered by C09J133/06
• CPC Class Codes: C09J 2301/302 the adhesive being pressure-sensitive, i.e. tacky at temperatures inferior to 30°C
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 428/31928 Ester, halide or nitrile of addition polymer

Abstract

The present invention is directed to improved aqueous based pressure sensitive adhesive emulsion polymers. Conventional emulsion based pressure sensitive adhesives are comprised of a copolymer comprised of polymerized units of acrylic esters and ethylenically unsaturated monomers, the copolymer having a T_g of from -15 to -70° C. The improvement in the aqueous based, emulsion polymerized pressure sensitive adhesives resides in the incorporation of a vinyl C_8-13 ester of a neo-acid into the copolymer present in the pressure sensitive adhesives. Such vinyl ester is formed from a mixture of propylene oligomers and such vinyl ester is represented by the chemical formula C_8-13 H_17-27 CO₂ CH═CH₂.

Claims

1. In an aqueous emulsion based pressure sensitive adhesive, capable of bonding to a substrate on instantaneous contact, comprised of a copolymer having polymerized units of C_1-12 esters of acrylic or methacrylic acid, the improvement residing in the properties of the pressure sensitive adhesive which comprises a copolymer having a glass transition temperature of from -25 to -50°

C. and consisting of polymerized units of the following monomers;

(a) 5-40 wt % of a vinyl C_8-13 ester of a neo-acid obtained from a feedstock of propylene oligomer;

(b) 30-80 wt % of a mixture of methyl methacrylate and at least one other monomer selected from the group consisting of 2-ethylhexyl acrylate and butyl acrylate; and

(c) an alpha, beta-ethylenically unsaturated monocarboxylic acid in an amount from 2% up to 10 wt %.

2. The emulsion of claim 1 wherein the mixture is present in an amount of from 40 to 70 wt %.

3. The emulsion of claim 2 wherein the C_8-13 vinyl ester of a neo-acid is vinyl versatate.

4. The emulsion of claim 3, wherein the copolymer consists of polymerized units of methyl methacrylate, 2-ethylhexyl acrylate, vinyl versatate and acrylic acid.

5. The emulsion of claim 2 wherein the level of vinyl C_8-13 ester of a neo-acid obtained from a feedstock of propylene oligomers is from 15 to 30 wt %.

6. The emulsion of claim 5 wherein the copolymer consists of polymerized units of methyl methacrylate, 2-ethylhexyl acrylate, acrylic acid and vinyl versatate.