Adhesive composition and low temperature applicable adhesive sheet

• US 20040219193A1
• Filed: 02/20/2004
• Published: 11/04/2004
• Est. Priority Date: 08/31/2001
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Takamatsu, Yorinobu, Abe, Hidetoshi
• Application Number:
  US10/487,369
• Publication Number:
  US 20040219193A1
• Time in Patent Office: Days
• US Class Current: 424/449
• CPC Class Codes: C08L 2666/20 Macromolecular compounds having nitrogen in the main chain according to C08L75/00 - C08L79/00; Derivatives thereof
• CPC Class Codes: C08L 67/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence
• CPC Class Codes: C08L 69/00 Compositions of polycarbonates; Compositions of derivatives of polycarbonates
• CPC Class Codes: C08L 77/02 Polyamides derived from omega-amino carboxylic acids or from lactams thereof C08L77/10 takes precedence
• CPC Class Codes: C09J 11/08 Macromolecular additives
• CPC Class Codes: C09J 133/02 Homopolymers or copolymers of acids; Metal or ammonium salts thereof
• CPC Class Codes: C09J 2467/00 Presence of polyester
• CPC Class Codes: C09J 7/22 Plastics; Metallised plastics
• CPC Class Codes: C09J 7/38 Pressure-sensitive adhesives [PSA]

Abstract

An adhesive composition having pressure sensitivity includes an adhesive polymer and a nonadhesive polymer. The adhesive polymer has a glass transition point by a dynamic viscoelasticity measuring method of −60° C. to −5° C., and the nonadhesive polymer has a glass transition point by a differential scanning calorimeter of −5° C. or less, and a fusing point of higher than 25° C. by a differential scanning calorimeter, and also has compatibility with the adhesive polymer in uncrystallized state. The adhesive composition can effectively enhance pressure sensitive adhesivity at low temperatures and tack suppression effect at the same time, which makes easy an accurate positioning of the site for sticking, and which can be easily stuck by press fitting even in an environment of low temperature of lower than 0° C.

Claims

1. An adhesive composition having pressure sensitivity comprising:

an adhesive polymer and

a nonadhesive polymer,

wherein the adhesive polymer has a glass transition point by a dynamic viscoelasticity measuring method of −

60°

C. to −

5°

C., and the nonadhesive polymer has a glass transition point by a differential scanning calorimeter of −

5°

C. or less, and a fusing point of higher than 25°

C. by a differential scanning calorimeter, and also has compatibility with the adhesive polymer in uncrystallized state.

2. An adhesive composition according to claim 1, wherein the adhesive composition is obtained by mixing almost uniformly a first solution in which the adhesive polymer is dissolved, and a second solution in which the nonadhesive polymer is dissolved to give a mixed solution, and drying the mixed solution.

3. An adhesive composition according to claim 1, wherein a probe tack measured by a method based on ASTM D2979 under conditions of 25°

C., contact pressure of 100 g/cm², contact time of 1 second, and releasing speed of 10 mm/second is lower than 7N, and a 180 degrees releasing strength measured at a releasing speed of 300 mm/minute, in −

5°

C. environment is 20 N/25 mm or more, after being stuck to a melamine baking finish plate and being left to stand for 5 minutes under −

5°

C. environment.

4. An adhesive composition according to claim 1, wherein the adhesive polymer has at least one alkyl group having 4 to 8 carbons including at least one butyl group, and at least one carboxyl group, and monomer units including alkyl groups having 4 to 8 carbons in a percentage of 60 to 99 mole % in all molecules.

5. An adhesive composition according to claim 1, wherein the adhesive polymer has a polycaprolactone skeleton or a polycarbonate skeleton in the molecule.

6. A low temperature applicable adhesive sheet comprising:

a substrate, and

an adhesive layer comprising the adhesive composition arranged at least on one main surface of the substrate,

wherein the adhesive composition includes an adhesive polymer and a nonadhesive polymer, the adhesive polymer has a glass transition point by a dynamic viscoelasticity measuring method of −

60°

C. to −

5°

C., and the nonadhesive polymer has a glass transition point by a differential scanning calorimeter of −

5°

C. or less, and a fusing point of higher than 25°

C. by a differential scanning calorimeter, and also has compatibility with the adhesive polymer in uncrystallized state, and

the substrate includes a polymer film, and has a breaking elongation of 50% or more at −

5°

C. at an elastic stress rate of 300 mm/min and a 50% elongation stress of 10 to 200 MPa at an elastic stress rate of 300 mm/min at −

5°

C.