Aqueous emulsion and adhesive in which same is used

Patent metadata

Field	Value
Publication number	US-9963520-B2
Application number	US-201515537996-A
Country	US
Kind code	B2
Filing date	Dec 24, 2015
Priority date	Dec 26, 2014
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

The present invention relates to an aqueous emulsion including an ethylenically unsaturated monomer unit-containing polymer as a dispersoid and a polyvinyl alcohol as a dispersant. The content of a free polyvinyl alcohol in the aqueous emulsion is 0.2 to 20 parts by mass relative to 100 parts by mass of the ethylenically unsaturated monomer unit-containing polymer. The free polyvinyl alcohol has a degree of saponification of 80.0 to 99.5 mol % and a viscosity-average degree of polymerization of 200 to 5000, and the free polyvinyl alcohol has a symmetry factor (W 0.05h /2f) that satisfies the following expression (1) as determined by gradient high-performance liquid chromatography for reversed-phase separation using a water-acetone eluent according to JIS K 0124 (2011).

0.85≤ W 0.05h /2 f ≤1.30  (1)

(The definitions of the symbols are omitted.)

First claim

The invention claimed is:

1. An aqueous emulsion comprising an ethylenically unsaturated monomer unit-containing polymer as a dispersoid and a polyvinyl alcohol as a dispersant,
wherein
an amount of the polyvinyl alcohol is present in the form of a free polyvinyl alcohol in the aqueous emulsion,
the content of the free polyvinyl alcohol is 0.2 to 20 parts by mass relative to 100 parts by mass of the ethylenically unsaturated monomer unit-containing polymer,
the free polyvinyl alcohol has a degree of saponification of 80.0 to 99.5 mol % and a viscosity-average degree of polymerization of 200 to 5000, and
the free polyvinyl alcohol has a symmetry factor (W 0.05h /2f) that satisfies the following expression (1) as determined by gradient high-performance liquid chromatography for reversed-phase separation using a water-acetone eluent according to JIS K 0124 (2011):
0.85≤ W 0.05h /2 f≤ 1.30  (1),

where W 0.05h represents a peak width at 5% peak height and f represents a distance from a leading edge point a at 5% peak height to an intersection point b between a horizontal line passing through the leading edge point a and a vertical line passing through a peak top.

2. The aqueous emulsion according to claim 1 , produced by emulsion polymerizing an ethylenically unsaturated monomer using a polyvinyl alcohol in an amount of 0.5 to 40 parts by mass relative to 100 parts by mass of the ethylenically unsaturated monomer, wherein the polyvinyl alcohol has a symmetry factor (W 0.05h /2f) that satisfies the following expression (2) as determined by gradient high-performance liquid chromatography for reversed-phase separation using a water-acetone eluent according to JIS K 0124 (2011):
0.70≤ W 0.05h /2 f≤ 1.10  (2),

where W 0.05h represents a peak width at 5% peak height and f represents a distance from a leading edge point a at 5% peak height to an intersection point b between a horizontal line passing through the leading edge point a and a vertical line passing through a peak top.

3. The aqueous emulsion according to claim 1 , wherein the ethylenically unsaturated monomer unit-containing polymer is a polymer containing a unit derived from at least one selected from the group consisting of a vinyl ester monomer, a (meth)acrylic acid ester monomer, a styrene monomer, and a diene monomer, and the content of the unit is 70 mass % or more of the total monomer units of the polymer.

4. The aqueous emulsion according to claim 1 , further comprising a polyfunctional isocyanate compound.

5. An adhesive comprising the aqueous emulsion according to claim 4 .

6. A method for producing the aqueous emulsion according to claim 1 , comprising emulsion polymerizing an ethylenically unsaturated monomer using a polyvinyl alcohol as a dispersant, wherein the polyvinyl alcohol is used in an amount of 0.5 to 40 parts by mass relative to 100 parts by mass of the ethylenically unsaturated monomer, and the polyvinyl alcohol has a symmetry factor (W 0.05h /2f) that satisfies the following expression (2) as determined by gradient high-performance liquid chromatography for reversed-phase separation using a water-acetone eluent according to JIS K 0124 (2011):
0.70≤ W 0.05h /2 f≤ 1.10  (2),

where W 0.05h represents a peak width at 5% peak height and f represents a distance from a leading edge point a at 5% peak height to an intersection point b between a horizontal line passing through the leading edge point a and a vertical line passing through a peak top.

Assignees

• Kuraray Co
• Kuraray Asia Pacific Pte Ltd

Inventors

• Maki Hideki
• Nakamae Masato

Classifications

• C09J133/04

  Homopolymers or copolymers of esters {(C09J143/04 takes precedence)} · CPC title

• C08G18/6212

  Polymers of alkenylalcohols; Acetals thereof; Oxyalkylation products thereof · CPC title

• C08G18/2835

  having less than 5 ether groups · CPC title

• C08F8/12

  Hydrolysis · CPC title

• C09J157/00

  Adhesives based on unspecified polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title