Heat activated pressure sensitive adhesive

Patent metadata

Field	Value
Publication number	US-9453148-B2
Application number	US-201314649744-A
Country	US
Kind code	B2
Filing date	Dec 2, 2013
Priority date	Dec 11, 2012
Publication date	Sep 27, 2016
Grant date	Sep 27, 2016

Abstract

A composition having three components. The first component is from 20 to 80 wt % of a styrene-diene block copolymer having from 10-30 wt % polymerized units of styrene, wherein the block copolymer is present as a dispersion of copolymer in water, and the dispersion contains less than 5 wt % organic solvent based on total dispersion weight. The second component is from 0.5 to 20 wt % of a plasticizer. The third component is from 20 to 80 wt % of a tackifier.

First claim

The invention claimed is:

1. A composition comprising: (a) from 20 to 80 dry wt % of a styrene-diene block copolymer having from 10-30 wt % polymerized units of styrene, wherein the block copolymer is present as a dispersion of copolymer in water, and said dispersion contains less than 5 wt % organic solvent based on total dispersion weight; (b) from 0.5 to 20 dry wt % of a plasticizer; and (c) from 20 to 80 dry wt % of a tackifier.

2. The composition of claim 1 in which Hoy Δδ solubility parameter for the plasticizer and polystyrene is from 2.5 to 30 (mJ/m 3 ) 1/2 .

3. The composition of claim 2 in which the tackifier comprises a rosin ester resin, a non-hydrogenated aliphatic C 5 resin, a hydrogenated aliphatic C 5 resin, an aromatic modified C 5 resin, a terpene resin, a hydrogenated C 9 resin, or combinations thereof.

4. The composition of claim 3 in which the styrene-diene block copolymer has 10-70 wt % diblock content and 30-90 wt % triblock content and the dispersion of copolymer in water comprises a dispersant selected from the group consisting of C 18 -C 32 aliphatic carboxylic acids and olefin-acrylic acid copolymers.

5. The composition of claim 4 in which the tackifier has a softening point from 65 to 180° C.

6. The composition of claim 5 in which the composition comprises: (a) from 25 to 65 dry wt % of the copolymer; (b) from 4 to 15 dry wt % of the plasticizer; and (c) from 25 to 70 dry wt % of the tackifier.

7. The composition of claim 6 in which the plasticizer is amorphous and has a softening point from 50-150° C.

8. A method for preparing a heat-activated pressure sensitive adhesive; said method comprising combining: (a) from 20 to 80 dry wt % of a styrene-diene block copolymer having from 10-30 wt % polymerized units of styrene, wherein the block copolymer is present as a dispersion in water, and the dispersion contains less than 5 wt % organic solvent based on total dispersion weight; (b) from 0.5 to 20 dry wt % of a plasticizer; and (c) from 20 to 80 dry wt % of a tackifier; to produce an adhesive composition; and coating the adhesive composition on paper or plastic film, said paper or plastic film having a thickness from 12 to 130 microns.

9. The method of claim 8 in which Hoy Δδ solubility parameter for the plasticizer and polystyrene is from 2.5 to 30 (MJ/m 3 ) 1/2 .

10. The method of claim 9 in which the adhesive composition is prepared by combining: (a) from 25 to 65 dry wt % of the copolymer; (b) from 4 to 15 dry wt % of the plasticizer; and (c) from 25 to 70 dry wt % of the tackifier.

Assignees

• Rohm & Haas
• Dow Global Technologies Llc

Inventors

• Einsla Melinda L
• Griffith Jr William B
• Himmelberger Daniel W
• Lane Melissa
• Malotky David L

Classifications

• C09J7/35 Primary

  Heat-activated · CPC title

• C09J153/02

  Vinyl aromatic monomers and conjugated dienes · CPC title

• C09J109/06 Primary

  Copolymers with styrene · CPC title

• C09J7/0203

  Chemistry & Metallurgy · mapped topic