Hot melt pressure sensitive adhesive and diaper tape closures coated therewith

• US 4,411,954 A
• Filed: 08/16/1982
• Issued: 10/25/1983
• Est. Priority Date: 08/16/1982
• Status: Expired due to Term

• Current Assignee: National Starch And Chemical Corporation (Ingredion Incorporated)
• Original Assignee: National Starch And Chemical Corporation (Ingredion Incorporated)
• Inventors: Puletti, Paul P., Butch, Peter J. III
• Primary Examiner(s): HERBERT JR, THOMAS
• Application Number:
  US06/408,357
• Time in Patent Office: 435 Days
• Field of Search: 428/355, 428/343, 428/346, 428/913, 428/914, 428/349, 526/237, 525/339, 525/332.9
• US Class Current: 428/343
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 2666/28 Non-macromolecular organic substances
• CPC Class Codes: C09J 153/025 modified
• CPC Class Codes: C09J 7/387 Block-copolymers
• CPC Class Codes: Y10S 428/913 Material designed to be responsive to temperature, light, moisture
• CPC Class Codes: Y10S 428/914 Transfer or decalcomania
• CPC Class Codes: Y10T 428/28 Web or sheet containing structurally defined element or component and having an adhesive outermost layer
• CPC Class Codes: Y10T 428/2813 Heat or solvent activated or sealable
• CPC Class Codes: Y10T 428/2826 Synthetic resin or polymer
• CPC Class Codes: Y10T 428/2883 including addition polymer of diene monomer [e.g., SBR, SIS, etc.]

Abstract

Hot melt pressure sensitive adhesives are formulated using as a base resin a mixture of a styrene-isoprene-styrene block copolymer together with a specific selectively hydrogenated block copolymer within critically defined ratios. The resultant adhesives as well as the tapes coated therewith are characterized by a unique combination of adhesion and heat and oxidative resistance properties.

Claims

1. Pressure sensitive tape comprising a sheet backing coated with a layer of normally tacky and hot melt pressure-sensitive adhesive comprising

(a) 15 to 40% by weight of a mixture of an A-B-A styrene-isoprene-styrene copolymer and a selectively hydrogenated A-B-A type block copolymer wherein the non-elastomeric block A units in both A-B-A copolymers are present in amounts less than about 25% by weight and wherein the weight ratio of the styrene-isoprene-styrene copolymer to the selectively hydrogenated copolymer is within the range of 10:

90 to 40;

60;

(b) 30 to 70% by weight of a tackifying resin;

(c) 5 to 30% by weight of a plasticizing oil or liquid polyterpene tackifying resin; and

(d) 0.05 to 2.0% by weight of an antioxidant.

2. The pressure sensitive tape of claim 1 wherein the adhesive comprises the mixture of block copolymers in amounts from 20 to 30%;

the tackifying resin in amounts from 50 to 60%;

the oil or liquid tackifying resin in amounts from 15 to 25%, and the antioxidant in amounts of about 0.5%, by weight of the hot melt composition.

3. A hot melt pressure sensitive adhesive composition comprising

(a) 15 to 40% by weight of a mixture of an A-B-A styrene-isoprene-styrene copolymer and a selectively hydrogenated A-B-A type block copolymer wherein the non-elastomeric block A units in both A-B-A copolymers are present in amounts less than about 25% by weight and wherein the weight ratio of the styrene-isoprene-styrene copolymer to the selectively hydrogenated copolymer is within the range of 10:

90 to 40;

60;

(b) 30 to 70% by weight of a tackifying resin;

(c) 5 to 30% by weight of a plasticizing oil or liquid polyterpene tackifying resin; and

(d) 0.05 to 2.0% by weight of an antioxidant.

4. The hot melt adhesive composition of claim 3 wherein the ratio of non-elastomeric block A units to elastomeric block B units in the selectively hydrogenated copolymer is 14:

86.

5. The hot melt adhesive composition of claim 3 wherein the ratio of the styrene-isoprene-styrene copolymer to the selectively hydrogenated copolymer is within the range of 25:

75 to 35;

65.

6. The hot melt adhesive composition of claim 3 wherein the ratio of the styrene-isoprene-styrene copolymer to the selectively hydrogenated copolymer is 30:

70.

7. The hot melt adhesive composition of claim 3 comprising a mixture of block copolymers in amounts from 20 to 30%;

the tackifying resin in amounts from 50 to 60%;

the oil or liquid tackifying resin in amounts, from 15 to 25%, and the antioxidant in amounts of about 0.5%, by weight of the hot melt composition.

8. The hot melt adhesive composition of claim 3 wherein the tackifying resin is selected from the class consisting of natural and modified rosins;

glycerol and pentaerythritol esters of natural and modified rosins;

polyterpene resins having a softening point, as determined by ASTM method E28 58T, of from about 60°

to 140°

C;

aliphatic petroleum hydrocarbon resins having a Ball and Ring softening point of from about 60°

to 140°

C. and the hydrogenated derivatives thereof, aromatic petroleum hydrocarbon resins and the hydrogenated derivatives thereof; and

alicyclic petroleum hydrocarbon resins and the hydrogenated derivatives thereof.

9. The hot melt adhesive composition of claim 3 wherein the plasticizing oil is a naphthenic or paraffinic process oil.

10. The hot melt adhesive composition of claim 3 wherein the liquid polyterpene tackifying resin consists essentially of polymerized structures derived from aliphatic dienes and mono-olefins of 5 to 6 carbon atoms.