Contamination-tolerant pressure-sensitive adhesive tape

• US 4,163,077 A
• Filed: 04/19/1978
• Issued: 07/31/1979
• Est. Priority Date: 04/19/1978
• Status: Expired due to Term

• Current Assignee: 3M Company
• Original Assignee: 3M Company
• Inventors: Boaz, David P., Antonsen, Stephen A.
• Primary Examiner(s): Robinson, Elis P.
• Application Number:
  US05/897,851
• Time in Patent Office: 468 Days
• Field of Search: 428/355, 428/40, 428/352, 428/521, 260/27 BB, 128/287
• US Class Current: 428/355.0BL
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C09J 153/02 Vinyl aromatic monomers and conjugated dienes
• CPC Class Codes: C09J 7/387 Block-copolymers
• CPC Class Codes: Y10T 428/1452 Polymer derived only from ethylenically unsaturated monomer
• CPC Class Codes: Y10T 428/2839 with release or antistick coating
• CPC Class Codes: Y10T 428/2883 including addition polymer of diene monomer [e.g., SBR, SIS, etc.]
• CPC Class Codes: Y10T 428/31931 Polyene monomer-containing

Abstract

Normally tacky and pressure-sensitive adhesive tape which displays good adhesion and shear properties, even when contaminated with dust, e.g., talcum powder. The adhesive is a rubbery block copolymer (especially styrene-isoprene-styrene), tackified with a combination of certain liquid and solid tackifiers. The tape is especially useful as a closure for disposable diapers.

Claims

1. Pressure-sensitive tape comprising a sheet backing coated with a layer of normally tacky and pressure-sensitive adhesive which is not only capable of maintaining useful bonding properties even after its surface has been contaminated with talc but which also has good shear adhesion, a force of at least 15 grams per centimeter width being required to remove said pressure-sensitive tape from a talc-contaminated polyethylene film, said adhesive consisting essentially of a blend of 100 parts by weight of

(a) 5-25 parts by weight of a rubbery synthetic block copolymer selected from the class consisting of:

(1) A-B, A-B-A or blends of A-B and A-B-A wherein A is a polymer of styrene and B is selected from the class consisting of homopolymers of isoprene and copolymers of ethylene and butylene and

(2) radial or teleblock copolymer consisting of several polystyrene-terminated elastomeric branches, each of said branches being a homopolymer of isoprene extending from a central hub;

(b) 15-50 parts by weight of polyterpene-type tackifier resin which is solid at room temperature; and

(c) 40-75 parts by weight of a polyterpene-type tackifier resin which is liquid at room temperature.

2. The tape of claim 1 wherein the adhesive composition falls within area I on the accompanying drawing.

3. The tape of claim 1 wherein the adhesive composition falls within area II on the accompanying drawing.

4. The tape of claim 3 wherein the rubbery block copolymer is a linear styrene:

isoprene;

styrene copolymer containing about 10-20% styrene.

5. The tape of claim 3 wherein the rubbery block copolymer is a radial or teleblock copolymer consisting of several polystyrene-terminated elastomeric branches, each of said branches being a homopolymer of isoprene extending from a central hub.

6. The tape of claim 1 wherein the adhesive composition falls within area III on the accompanying drawing.

7. The tape of claim 6 wherein the rubbery block copolymer is a styrene:

isoprene;

styrene copolymer containing about 10-20% styrene.

8. The tape of claim 6 wherein the rubbery block copolymer is a radial or teleblock copolymer consisting of several polystyrene-terminated elastomeric branches, each of said branches being a homopolymer of isoprene extending from a central hub.

9. The tape of claim 1 wherein the adhesive composition falls within area IV on the accompanying drawing.

10. The tape of claim 9 wherein the rubbery block copolymer is a styrene:

isoprene;

styrene copolymer containing about 10-20% styrene.

11. The tape of claim 9 wherein the rubbery block copolymer is a radial or teleblock copolymer consisting of several polystyrene-terminated elastomeric branches, each of said branches being a homopolymer of isoprene extending from a central hub.