Curable silicone pressure sensitive adhesive tape and bonding method employing same

• US 5,300,171 A
• Filed: 02/16/1993
• Issued: 04/05/1994
• Est. Priority Date: 08/22/1991
• Status: Expired due to Term

• Current Assignee: Dow Corning Corporation (Dow, Inc.)
• Original Assignee: Dow Corning Corporation (Dow, Inc.)
• Inventors: Clark, Joseph N., Mealey, Shawn K., Schoenherr, William J., Braun, Joseph T., Johnson, Virgil J.
• Primary Examiner(s): Gallagher, John J.
• Application Number:
  US08/026,221
• Time in Patent Office: 413 Days
• Field of Search: 428/40, 428/355, 427/208, 427/208.4, 156/235, 156/313, 156/249, 156/329, 528/38, 525/477
• US Class Current: 156/249
• CPC Class Codes: C08L 2666/44 Silicon-containing compounds
• CPC Class Codes: C09J 183/04 Polysiloxanes
• CPC Class Codes: C09J 183/14 in which at least two but not all the silicon atoms are connected by linkages other than oxygen atoms C09J183/10 takes precedence
• CPC Class Codes: C09J 2433/00 Presence of (meth)acrylic polymer
• CPC Class Codes: C09J 2483/006 in the substrate
• CPC Class Codes: C09J 7/25 based on macromolecular compounds obtained otherwise than by reactions involving only carbon-to-carbon unsaturated bonds
• CPC Class Codes: C09J 7/38 Pressure-sensitive adhesives [PSA]
• CPC Class Codes: E06B 3/5427 the panes mounted flush with the surrounding frame or with the surrounding panes E06B3/5436 takes precedence; supporting structures for curtain walls E04B2/885
• CPC Class Codes: E06B 3/56 by means of putty, cement, or adhesives only E06B3/64 E06B3/5427 take precedence
• CPC Class Codes: E06B 3/6202 positioned between adjoining panes without separate glazing bar
• CPC Class Codes: Y10T 428/1452 Polymer derived only from ethylenically unsaturated monomer
• CPC Class Codes: Y10T 428/2852 Adhesive compositions

Abstract

A pressure sensitive adhesive tape comprising a tape substrate having at least a portion of one or more sides coated with a silicone pressure sensitive adhesive is constructed using an adhesive which cures to a permanent adhesive. The adhesive is covered on the outer side with a release film, preferably coated with a fluorosilicone release layer, to allow storage of the tape. Preferably the curable silicone pressure sensitive adhesive is cured upon exposure to moisture, the tape therefore being stored in the absence of moisture. A silicone elastomeric structural glazing tape is made by using a silicone elastomer as the tape substrate. The tape can be used to bond glazing panels to building components without the use of other means of fastening.

Claims

1. A pressure sensitive adhesive tape comprising a tape substrate having at least a portion of one or more sides coated with a silicone pressure sensitive adhesive which is curable to a permanent adhesive in the presence of moisture, the silicone pressure sensitive adhesive comprising a homogeneous mixture of

(A) a silanol-free silicone pressure sensitive adhesive component bearing curing radicals having the formula

View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)

2. The pressure sensitive adhesive tape of claim 1 in which (A) the silanol-free silicone pressure sensitive adhesive component bears 1 to 100 millimols of curing radicals per 100 parts by weight of the silicone pressure sensitive adhesive component.

3. The pressure sensitive adhesive tape of claim 2 in which all other silicon bonded radicals of the silanol-free silicone pressure sensitive adhesive component (A) being selected from the group consisting of divalent oxygen atoms linking silicon atoms, hydrogen atoms and monovalent hydrocarbon radicals;

and Z radicals are selected from the group consisting of --O--, --CH₂ CH₂ --, --CH₂ CH₂ SiMe₂ O--, and --CH₂ CH₂ SiMe₂ OSiMe₂ O-- where Me denotes methyl.

4. The pressure sensitive adhesive tape of claim 1 in which the silicone pressure sensitive adhesive is covered by a release film.

5. The pressure sensitive adhesive tape of claim 4 where the tape is enclosed in a moisture impermeable container.

6. The pressure sensitive adhesive tape of claim 5 in which a desiccant is also enclosed in the moisture impermeable container.

7. The pressure sensitive adhesive tape of claim 6 in which the tape substrate is a silicone elastomer.

8. The pressure sensitive adhesive tape of claim 7 in which two opposing sides of the tape substrate are coated with the silicone pressure sensitive adhesive.

9. The pressure sensitive adhesive tape of claim 8 in which the tape substrate has a rectangular shape in which two opposing adhesive-bearing surfaces are flat or convex with the maximum height of the convex surface less than 1.2 percent of the width of the convex surface, and in which two opposing non-adhesive-bearing surfaces are flat or concave.

10. The pressure sensitive adhesive tape of claim 9 in which all other silicon bonded radicals of the silanol-free silicone pressure sensitive adhesive component (A) being selected from the group consisting of divalent oxygen atoms linking silicon atoms, hydrogen atoms and monovalent hydrocarbon radicals;

and Z radicals are selected from the group consisting of --O--, --CH₂ CH₂ --, --CH₂ CH₂ SiMe₂ O--, and --CH₂ CH₂ SiMe₂ OSiMe₂ O-- where Me denotes methyl.

11. A method of bonding two articles together with the pressure sensitive adhesive tape of claim 1, the method comprising:

(A) placing the adhesive tape in contact with the two articles so that a surface of each of the two articles is in contact with a portion of the silicone pressure sensitive adhesive,

(B) exposing the silicone pressure sensitive adhesive in contact with the articles to moisture until the silicone pressure sensitive adhesive cures to a permanent adhesive.

12. A method of bonding two articles together with the pressure sensitive adhesive tape of claim 9, the method comprising:

(A) applying a non-covered, adhesive-bearing surface of the tape to a surface of the first article

(B) removing the release film from the tape, uncovering a second adhesive-bearing surface of the tape,

(C) applying a surface of the second article to the second adhesive-bearing surface of the tape with sufficient pressure to obtain adherence between the first article, the tape, and the second article, and

(D) exposing the silicone pressure sensitive adhesive in contact with the articles to moisture until the silicone pressure sensitive adhesive cures to a permanent adhesive.

13. The method of claim 12 in which the first article is a curtainwall mullion and the second article is an

14. A method of manufacturing the pressure sensitive adhesive tape of claim 1, the method comprising applying an adhesive-bearing surface of a transfer sheet to the tape substrate, the transfer sheet comprising a release liner coated with a layer of the silicone pressure sensitive adhesive.

15. A method of manufacturing the pressure sensitive adhesive tape of claim 9, the method comprising

(A) applying an adhesive-bearing surface of a transfer sheet to the tape substrate, the transfer sheet comprising a release liner coated with a layer of the silicone pressure sensitive adhesive,

(B) peeling the release liner off the surface of the silicone pressure sensitive adhesive,

(C) covering the surface of the silicone pressure sensitive adhesive with a release film of polyethylene, and then

(D) packaging the pressure sensitive adhesive tape in a moisture-impermeable container.