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US 2014/0273692 A1Published application
High tack repositionable adhesives and substrates and methods for their manufacture
AssigneeNCR Corporation
InventorsMartha Patricia Wild, Zhengzhi Zhou
Life of this patent
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Abstract
High tack repositionable adhesive obtained by combining an acrylic copolymer permanent pressure sensitive adhesive with a hydrophobically modified ethoxylate urethane (HEUR) thickener. The adhesive provides repositionable substrates, such as thermal paper, with high tack. Methods for preparing the high tack repositionable adhesive are provided.
Claims19
A high tack repositionable pressure-sensitive adhesive comprising a mixture which comprises:
- A. 99.9-95 wt % of a permanent acrylic copolymer pressure sensitive adhesive having a glass transition temperature of less than −10° C. comprising about 70% to 99.5% of a C1-C14 alkyl acrylate ester monomers and/or C1-C14 alkyl(meth)acrylate ester monomers and from 30% to 0.5% of oil-insoluble/water soluble ionic monomers or polar monomers or maleic anhydride, and
- B. 0.1-5.0 wt % of a hydrophobically modified ethoxylate urethane thickener comprising urethane polymers chains with hydrophobic groups at the terminal ends which contain a total of at least 20 carbon atoms and are linked through hydrophilic polyethylene oxide segments with a molecular weight of at least about 1500.
A high tack repositionable pressure-sensitive adhesive comprising a mixture which comprises:
- A. 99.9-95 wt. % of a permanent acrylic copolymer pressure sensitive adhesive having a glass transition temperature of less than −50° C. comprising about 70% to 99.5% alkyl acrylate ester monomers selected from the group consisting of isooctyl acrylate and 2-methyl butyl acrylate and from 30% to 0.5% of oil-insoluble/water soluble ionic monomers or polar monomers or maleic anhydride, and
- B. 0.1-5.0 wt. % of a hydrophobically modified ethoxylate urethane thickener comprising urethane polymers chains with hydrophobic groups at the terminal ends which contain a total of at least 20 carbon atoms and are linked through hydrophilic polyethylene oxide segments with a molecular weight of at least about 1500,
- in a weight ratio of 100:1-4 of component A to component B.
A process for preparing a repositionable pressure-sensitive adhesive comprising:
- A. stirring or agitating the following to obtain a uniform mixture,
- a. 99.9-95 wt. % of a permanent acrylic copolymer pressure sensitive adhesive having a glass transition temperature of less than −10° C. comprising about 70% to 99.5% of a C1-C14 alkyl acrylate ester monomers and/or C1-C14 alkyl(meth)acrylate ester monomers and from 30% to 0.5% of oil-insoluble/water soluble ionic monomers or polar monomers or maleic anhydride, and
- b. 0.1-5.0 wt % of a hydrophobically modified ethoxylate urethane thickener comprising urethane polymers chains with hydrophobic groups at the terminal ends which contain a total of at least 20 carbon atoms and are linked through hydrophilic polyethylene oxide segments with a molecular weight of at least about 1500;
- B. terminating step A. and letting the mixture stand until the viscosity builds to at least double in magnitude.
1 more element
Dependencies are inferred from the claim text.