Low temperature hot melt adhesives for disposable articles with high creep resistance

Patent metadata

Field	Value
Publication number	US-9296930-B2
Application number	US-201514620540-A
Country	US
Kind code	B2
Filing date	Feb 12, 2015
Priority date	Feb 18, 2011
Publication date	Mar 29, 2016
Grant date	Mar 29, 2016

Abstract

The present invention is directed to adhesives suitable for application using a hot melt process at a relatively low temperature in the range of about 110° C. to about 130° C. Such adhesives exhibit desirable viscoelastic properties and are suitable for bonding an elastic attachment in the manufacture of disposable articles, such as disposable diapers.

First claim

The invention claimed is:

1. A method of forming an article comprising:
(a) applying a low application temperature hot melt adhesive onto a substrate at a temperature in the range of from about 110° C. to about 130° C. at an add-on-level of about 20 to about 100 mg/m/strand;
(b) cooling the adhesive to room temperature;
wherein the low application temperature hot melt adhesive comprises:
i. 5 to 20 wt % of the styrenic block copolymer that (1) has a melt flow index greater than 33, measured in accordance with ASTM D 1238, and (2) has a styrene content greater than 40%;
ii. 0.5 to 5% wt % of the wax;
iii. 30-70 wt % of a tackifier that has a ring and ball softening point less than about 105° C.;
iv. 0.1-2 wt % of an antioxidant; and
v. optionally, up to 30 wt % of an oil; and

wherein the cooled adhesive has a creep performance of less than about 15% after 300% strain is applied on the cooled adhesive at 38° C. for four hours.

2. The method of claim 1 wherein the adhesive is applied by strand coating.

3. A method of forming an article comprising:
(a) applying the low application temperature hot melt adhesive onto a substrate at a temperature in the range of from about 110° C. to about 130° C. at an add-on-level of about 3 to about 30 mg/in; and
(b) cooling the adhesive to room temperature;
i. 5 to 20 wt % of the styrenic block copolymer that (1) has a melt flow index greater than 33, measured in accordance with ASTM D 1238, and (2) has a styrene content greater than 40%;
ii. 0.5 to 5% wt % of the wax;
iii. 30-70 wt % of a tackifier that has a ring and ball softening point less than about 105° C.;
iv. 0.1-2 wt % of an antioxidant; and
v. optionally, up to 30 wt % of an oil; and

wherein the cooled adhesive has a creep performance of less than about 25% after 300% strain is applied on the cooled adhesive at 38° C. for four hours.

4. The method of claim 3 wherein the adhesive is applied by spiral coating.

Assignees

• Henkel IP & Holding GmbH

Inventors

• Hu Yuhong
• Xenidou Maria

Classifications

• C09J191/06

  Waxes · CPC title

• C09J153/02 Primary

  Vinyl aromatic monomers and conjugated dienes · CPC title

• C08L91/06

  Waxes · CPC title

• C09J191/08

  Mineral waxes · CPC title

• C08L53/02

  of vinyl-aromatic monomers and conjugated dienes · CPC title