Stretch releasable adhesive tape

• US 8,557,378 B2
• Filed: 12/29/2009
• Issued: 10/15/2013
• Est. Priority Date: 12/31/2008
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Yamanaka, Michiko, Determan, Michael D., Everaerts, Albert I., Tran, Thu-Van T., Seth, Jayshree
• Primary Examiner(s): CHANG, VICTOR S
• Application Number:
  US13/142,004
• Publication Number:
  US 20110253301A1
• Time in Patent Office: 1,386 Days
• Field of Search: 428/343, 428/354, 428/355.AC
• US Class Current: 428/343
• CPC Class Codes: B32B 2262/101 Glass fibres
• CPC Class Codes: B32B 2264/10 Inorganic particles
• CPC Class Codes: B32B 2264/102 Oxide or hydroxide
• CPC Class Codes: B32B 2307/102 Insulating
• CPC Class Codes: B32B 2307/748 Releasability
• CPC Class Codes: B32B 2405/00 Adhesive articles, e.g. adhesive tapes
• CPC Class Codes: B32B 25/08 of synthetic resin
• CPC Class Codes: B32B 25/12 comprising natural rubber
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/283 comprising polysiloxanes
• CPC Class Codes: B32B 27/302 comprising aromatic vinyl (co)polymers, e.g. styrenic (co)polymers
• CPC Class Codes: B32B 27/308 comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 27/40 comprising polyurethanes
• CPC Class Codes: B32B 7/06 permitting easy separation
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: C08K 3/36 Silica
• CPC Class Codes: C08K 5/0025 Crosslinking or vulcanising agents; including accelerators
• CPC Class Codes: C08L 2205/02 containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 33/08 : Homopolymers or copolymers of acrylic acid esters
• CPC Class Codes: C09J 133/08 : Homopolymers or copolymers of acrylic acid esters
• CPC Class Codes: C09J 2301/302 : the adhesive being pressure-sensitive, i.e. tacky at temperatures inferior to 30°C
• CPC Class Codes: C09J 2301/308 : the adhesive tape or sheet losing adhesive strength when being stretched, e.g. stretch adhesive
• CPC Class Codes: C09J 2301/408 : additives as essential feature of the adhesive layer
• CPC Class Codes: C09J 2433/00 : Presence of (meth)acrylic polymer
• CPC Class Codes: C09J 2433/006 : in the substrate
• CPC Class Codes: C09J 7/24 : based on macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
• CPC Class Codes: C09J 7/385 : Acrylic polymers
• CPC Class Codes: Y02P 20/582 : Recycling of unreacted starting or intermediate materials
• 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 428/2848 : Three or more layers
• CPC Class Codes: Y10T 428/2891 : including addition polymer from alpha-beta unsaturated carboxylic acid [e.g., acrylic acid, methacrylic acid, etc.] Or derivative thereof

Abstract

Adhesive tapes, articles containing the adhesive tapes, methods of making the adhesive tapes, and uses of the adhesive tapes are described. The adhesive tape is stretch releasable and can be used to couple two substrates together. The adhesive tape can be removed easily to separate the two substrates for any reason. The adhesive tape includes a backing layer and at least one pressure-sensitive adhesive layer adjacent to the backing layer. The backing layer contains a first acrylic copolymer. Each pressure-sensitive adhesive layer contains a second acrylic copolymer plus inorganic particles that are dispersed or suspended in the second acrylic copolymer.

Claims

1. An adhesive tape comprising:

a backing layer comprising

(1) a first acrylic copolymer comprising a first polymerized product of a first polymerizable reaction mixture comprising

(a) a first crosslinker having at least two (meth)acryloyl groups in an amount up to 70 weight percent based on a total weight of polymerizable material in the first polymerizable reaction mixture; and

(b) either

(i) a first monovalent monomer mixture comprising

 

1) a low Tg yielding acrylic monomer in an amount equal to at least 40 weight percent based on the total weight of polymerizable material in the first polymerizable reaction mixture, wherein the low Tg yielding acrylic monomer has a glass transition temperature no greater than 20°

C. when polymerized to form a homopolymer; and

 

2) a first polar monomer in an amount up to 35 weight percent based on the total weight of polymerizable material in the first polymerizable reaction mixture;

or

(ii) a partially polymerized product of the first monovalent monomer mixture; and

a first pressure-sensitive adhesive layer that is adjacent to a first major surface of the backing layer and a second pressure-sensitive adhesive layer that is adjacent to a second major surface of the backing layer, wherein the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer each comprise

(1) a second acrylic copolymer that is different than the first acrylic copolymer, the second acrylic copolymer comprising a second polymerized product of a second polymerizable reaction mixture comprising

(a) a second crosslinker having at least two (meth)acryloyl groups in an amount up to 25 weight percent based on a total weight of polymerizable material in the second polymerizable reaction mixture; and

(b) either

(i) a second monovalent monomer mixture comprising

 

1) an alkyl(meth)acrylate having an alkyl group with at least 4 carbon atoms in an amount equal to at least 40 weight percent based on the total weight of polymerizable material in the second polymerizable reaction mixture; and

 

2) a second polar monomer in an amount up to 40 weight percent based on the total weight of polymerizable material in the second polymerizable reaction mixture;

or

(ii) a partially polymerized product of the second monovalent monomer mixture; and

(2) inorganic particles dispersed or suspended in the second acrylic copolymer in an amount up to 25 weight percent based on the total weight of second acrylic copolymer,

wherein, the adhesive tape is stretch releasing and is stretchable at least 50 percent in a first direction without breaking.

2. The adhesive tape of claim 1, wherein the backing layer further comprises inorganic particles dispersed or suspended in the first acrylic copolymer.

3. The adhesive tape of claim 1, wherein the first monovalent monomer mixture further comprises a high Tg yielding acrylic monomer in an amount up to 40 weight percent based on the total weight of the first polymerizable reaction mixture, wherein the high Tg yielding acrylic monomer has a Tg of at least 40°

C. when polymerized to form a homopolymer.

4. The adhesive tape of claim 1, wherein the adhesive tape is stretchable at least 300 percent in the first direction without breaking.

5. The adhesive tape of claim 1, wherein the inorganic particles in the pressure-sensitive adhesive layer comprises silica.

6. The adhesive tape of claim 5, wherein the silica is selected from fumed silica or silica aerogel particles.

7. An article comprising:

a first substrate;

a second substrate; and

an adhesive tape positioned between the first substrate and the second substrate, wherein the adhesive tape couples the first substrate to the second substrate and wherein the adhesive tape comprising

(A) a backing layer comprising

(1) a first acrylic copolymer comprising a first polymerized product of a first polymerizable reaction mixture comprising

(a) a first crosslinker having at least two (meth)acryloyl groups in an amount up to 70 weight percent based on a total weight of polymerizable material in the first polymerizable reaction mixture; and

(b) either

(i) a first monovalent monomer mixture comprising

 

1) a low Tg yielding acrylic monomer in an amount equal to at least 40 weight percent based on the total weight of polymerizable material in the first polymerizable reaction mixture, wherein the low Tg yielding acrylic monomer has a glass transition temperature no greater than 20°

C. when polymerized to form a homopolymer; and

 

2) a first polar monomer in an amount up to 35 weight percent based on the total weight of polymerizable material in the first polymerizable reaction mixture;

or

(ii) a partially polymerized product of the first monovalent monomer mixture; and

(B) a first pressure-sensitive adhesive layer that is adjacent to a first major surface of the backing layer and a second pressure-sensitive adhesive layer that is adjacent to a second major surface of the backing layer, wherein the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer each comprise

(1) a second acrylic copolymer that is different than the first acrylic copolymer, the second acrylic copolymer comprising a second polymerized product of a second polymerizable reaction mixture comprising

(a) a second crosslinker having at least two (meth)acryloyl groups in an amount up to 25 weight percent based on a total weight of polymerizable material in the second polymerizable reaction mixture; and

(b) either

(i) a second monovalent monomer mixture comprising

 

1) an alkyl(meth)acrylate having an alkyl group with at least 4 carbon in an amount equal to at least 40 weight percent based on the total weight of polymerizable material in the second polymerizable reaction mixture; and

 

2) a second polar monomer in an amount up to 40 weight percent based on the total weight of polymerizable material in the second polymerizable reaction mixture;

or

(ii) a partially polymerized product of the second monovalent monomer mixture; and

(2) inorganic particles dispersed or suspended in the second acrylic copolymer in an amount up to 25 weight percent based on the weight of the second acrylic copolymer; and

(C) a tab that extends beyond at least one of the first substrate and the second substrate, wherein pulling the tab stretches the adhesive tape and releases the adhesive tape from the first substrate, from the second substrate, or from both the first substrate and the second substrate and wherein the adhesive tape is stretchable to at least 50 percent in a first direction without breaking when the tab is pulled.

8. The article of claim 7, wherein the adhesive tape is optically clear and wherein first substrate and second substrate are each independently selected from a display, polarizer, touch panel, lens, reflector, diffraction grating, mirror, projection prism, or multilayer optical film.

9. The article of claim 7, wherein the adhesive tape is optically clear the second substrate is visible when viewed through the first substrate and the adhesive tape.

10. The article of claim 7, wherein the backing layer further comprises inorganic particles dispersed or suspended in the first acrylic copolymer.

11. The article of claim 7, wherein the first monovalent monomer mixture further comprises a high Tg yielding acrylic monomer in an amount up to 40 weight percent based on the total weight of the first polymerizable reaction mixture, wherein the high Tg yielding acrylic monomer has a Tg of at least 40°

C. when polymerized to form a homopolymer.

12. The article of claim 7, wherein the adhesive tape is stretchable to at least 300 percent in the first direction without breaking.

13. An article comprising:

a first substrate; and

an adhesive tape adhered to the first substrate, the adhesive tape comprising

(A) a backing layer comprising

(1) a first acrylic copolymer comprising a first polymerized product of a first polymerizable reaction mixture comprising

(a) a first crosslinker having at least two (meth)acryloyl groups in an amount up to 70 weight percent based on a total weight of polymerizable material in the first polymerizable reaction mixture; and

(b) either

(i) a first monovalent monomer mixture comprising

 

1) a low Tg yielding acrylic monomer in an amount equal to at least 40 weight percent based on the total weight of polymerizable material in the first polymerizable reaction mixture, wherein the low Tg yielding acrylic monomer has a glass transition temperature no greater than 20°

C. when polymerized to form a homopolymer; and

 

2) a first polar monomer in an amount up to 35 weight percent based on the total weight of polymerizable material in the first polymerizable reaction mixture;

or

(ii) a partially polymerized product of the first monovalent monomer mixture; and

(B) a first pressure-sensitive adhesive layer that is adjacent to a first major surface of the backing layer, wherein the first pressure-sensitive adhesive layer comprises

(1) a second acrylic copolymer that is different than the first acrylic copolymer, the second acrylic copolymer comprising a second polymerized product of a second polymerizable reaction mixture comprising

(a) a second crosslinker having at least two (meth)acryloyl groups in an amount up to 25 weight percent based on a total weight of polymerizable material in the second polymerizable reaction mixture; and

(b) either

(i) a second monovalent monomer mixture comprising

 

1) an alkyl(meth)acrylate having an alkyl group with at least 4 carbon in an amount equal to at least 40 weight percent based on the total weight of polymerizable material in the second polymerizable reaction mixture; and

 

2) a second polar monomer in an amount up to 40 weight percent based on the total weight of polymerizable material in the second polymerizable reaction mixture;

or

(ii) a partially polymerized product of the second monovalent monomer mixture; and

(2) inorganic particles dispersed or suspended in the second acrylic copolymer in an amount up to 25 weight percent based on the weight of the second acrylic copolymer; and

(C) a tab that extends beyond the first substrate, wherein pulling the tab stretches the adhesive tape and releases the adhesive tape from the first substrate and wherein the adhesive tape is stretchable to at least 50 percent in a first direction without breaking when the tab is pulled.

14. A method of coupling and decoupling two substrates, the method comprising:

providing a first and second substrate;

positioning an adhesive tape between the first substrate and the second substrate, wherein the adhesive tape couples the first substrate to the second substrate, the adhesive tape comprising

(A) a backing layer comprising

(1) a first acrylic copolymer comprising a first polymerized product of a first polymerizable reaction mixture that comprises

(a) a first crosslinker having at least two (meth)acryloyl groups in an amount up to 70 weight percent based on a total weight of polymerizable material in the first polymerizable reaction mixture; and

(b) either

(i) a first monovalent monomer mixture comprising

 

1) a low Tg yielding acrylic monomer in an amount equal to at least 40 weight percent based on the total weight of polymerizable material in the first polymerizable reaction mixture, wherein the low Tg yielding acrylic monomer has a glass transition temperature no greater than 20°

C. when polymerized to form a homopolymer; and

 

2) a first polar monomer in an amount up to 35 weight percent based on the total weight of polymerizable material in the first polymerizable reaction mixture;

or

(ii) a partially polymerized product of the first monovalent monomer mixture; and

(B) a first pressure-sensitive adhesive layer that is adjacent to a first major surface of the backing layer and a second pressure-sensitive adhesive layer that is adjacent to a second major surface of the backing layer, wherein the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer each comprise

(1) a second acrylic copolymer that is different than the first acrylic copolymer, the second acrylic copolymer comprising a second polymerized product of a second polymerizable reaction mixture comprising

(a) a second crosslinker having at least two (meth)acryloyl groups in an amount up to 25 weight percent based on a total weight of polymeric material in the second polymerizable reaction mixture;

(b) either

(i) a second monovalent monomer mixture comprising

 

1) an alkyl(meth)acrylate having an alkyl group with at least 4 carbon in an amount equal to at least 40 weight percent based on the total weight of polymerizable material in the second polymerizable reaction mixture;

 

2) a second polar monomer in an amount up to 40 weight percent based on the total weight of polymerizable material in the second polymerizable reaction mixture;

or

(ii) a partially polymerized product of the second monovalent monomer mixture; and

(2) inorganic particles dispersed or suspended in the second acrylic copolymer in an amount up to 25 weight percent based on the weight of the second acrylic copolymer; and

(C) a tab that extends beyond at least one of the first substrate and the second substrate; and

pulling on the tab of the adhesive tape to stretch the adhesive tape to release the adhesive tape from the first substrate, from the second substrate or from both the first substrate and the second substrate, wherein the adhesive tape is stretchable to at least 50 percent in a first direction without breaking.

15. The method of claim 14, wherein the backing layer further comprises up to 25 weight percent inorganic particles dispersed or suspended in the first acrylic copolymer.

16. The method of claim 14, wherein the adhesive tape is optically clear and wherein first substrate and second substrate are each independently selected from a display, polarizer, touch panel, lens, reflector, diffraction grating, mirror, projection prism, or multilayer optical film.