Repositionable adhesive tape

• US 5,389,438 A
• Filed: 04/08/1991
• Issued: 02/14/1995
• Est. Priority Date: 02/22/1990
• Status: Expired due to Term

• Current Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Original Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Inventors: Miller, John A., Clements, George J.
• Primary Examiner(s): Davis, Jenna L.
• Application Number:
  US07/681,655
• Time in Patent Office: 1,408 Days
• Field of Search: 428/355, 428/512, 525/95, 525/98, 525/99
• US Class Current: 428/355.0RA
• CPC Class Codes: A61F 13/58 Adhesive tab fastener elements A61F13/5611, A61F13/5616, A61F13/66 take precedence
• CPC Class Codes: A61L 15/58 Adhesives
• CPC Class Codes: B05B 12/24 made at least partly of flexible material, e.g. sheets of paper or fabric
• CPC Class Codes: C08L 2666/26 Natural polymers, natural resins or derivatives thereof according to C08L1/00 - C08L5/00, C08L89/00, C08L93/00, C08L97/00 or C08L99/00
• CPC Class Codes: C08L 53/00 Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 53/02 of vinyl-aromatic monomers and conjugated dienes
• CPC Class Codes: C09J 153/00 Adhesives based on block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Adhesives based on derivatives of such polymers
• CPC Class Codes: C09J 7/21 Paper; Textile fabrics
• CPC Class Codes: C09J 7/38 Pressure-sensitive adhesives [PSA]
• CPC Class Codes: C09J 7/387 Block-copolymers
• CPC Class Codes: Y10T 428/2861 having readily strippable combined with readily readhearable properties [e.g., stick-ons, etc.]
• CPC Class Codes: Y10T 428/2883 including addition polymer of diene monomer [e.g., SBR, SIS, etc.]
• CPC Class Codes: Y10T 428/31899 Addition polymer of hydrocarbon[s] only

Abstract

An adhesive of certain elastomeric block copolymers and tackifying materials can be hot-melt coated onto a flexible backing to provide an adhesive tape, two pieces of which can bond to each other to have excellent resistance to shear forces but can be easily peeled apart, even after prolonged periods of time. The adhesive can be low-tack or tack-free. When the novel adhesive is tacky, it can bind sheets into a note pad from which individual sheets can be removed, temporarily adhered to paper and other substrates, and later cleanly removed, even after prolonged contact.

Claims

1. A low-tack or no-tack adhesive consisting essentially of a composition of by weight:

from 20 to 80 parts of at least one elastomeric block copolymer selected from the group consisting of styrene/butadiene and styrene/isoprene block copolymers, and

correspondingly from 80 to 20 parts of tackifying material selected from the group consisting of tackifier resin and a blend of tackifier resin and liquid plasticizer oil, wherein the tackifier comprises 0 to 35 parts of a solid tackifier resin and from 0 to 80 parts of a liquid tackifying resin or plasticizing oil, and wherein the tackifier resin is selected from the group consisting of aliphatic hydrocarbon resins from the polymerization of unsaturated species with four to six carbon atoms, rosin esters and acids, aliphatic/aromatic liquid tackifiers, polyterpene tackifiers, hydrogenated tackifying resins, hydrogenated polyterpene resins and hydrogenated aliphatic and aliphatic/aromatic resins, and the liquid plasticizer oils are selected from the group consisting of mineral oil, naphthenic oil, paraffinic oil, and

aromatic oils, and mixtures thereof, which adhesive has a composite midblock glass transition temperature (CMTg) from 225 Kelvin to 240 Kelvin when the adhesive is based on styrene/isoprene block copolymers and a CMTg from 215 Kelvin to 235 Kelvin when the adhesive is based on styrene/butadiene block copolymers to provide an adhesive having no tack or low tack, which adhesive has a 90 degree peel value (as herein defined) of 0.1 to 2.7N/25 mm and a self-adhesion value (as herein defined ) of from 0.2 to 3.4N/25 mm.

2. An adhesive as defined in claim 1 and having a 90 degree Peel Value (as herein defined) of 0.1 to 2N/25 mm.

3. An adhesive as defined in claim 1 wherein the elastomeric block copolymer has a configuration selected from the group consisting of linear diblock and triblock, radial, star, and tapered block geometries.

4. An adhesive as defined in claim 1 and containing both a tackifier resin and a liquid plasticizer oil.

5. An adhesive as defined in claim 1 and comprising form 55 to 80 parts by weight of the elastomeric block copolymer.

6. An adhesive as defined in claim 5 wherein the CMTg is within 10°

Kelvin of the top of an aforementioned range.

7. An adhesive as defined in claim 1 and comprising from 20 to 45 parts by weight of the elastomeric block copolymer.

8. An adhesive as defined in claim 7 wherein the CMTg is within 10 Kelvin of the bottom of an aforementioned range, and the adhesive is a pressure-sensitive adhesive.