Pressure-sensitive adhesive tapes for gluing windows, in particular in mobile devices

Patent metadata

Field	Value
Publication number	US-9260631-B2
Application number	US-201113884098-A
Country	US
Kind code	B2
Filing date	Oct 27, 2011
Priority date	Nov 12, 2010
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

The invention relates to a double-sided adhesive tape, comprising a carrier layer and two exterior pressure-sensitive adhesive compound layers, wherein at least one of the pressure-sensitive adhesive compounds is the crosslinking product composed of a polymer compound which comprises at least the following components: A) a polymer component (component A) comprising 88 to 100 wt % of one or more polyacrylates (component A1) composed of at least: a) 1 to 15 wt %, relative to component A1, of one or more monomers having at least one ethylenically unsaturated bond, each being selected such that the glass transition temperatures T G of the corresponding homopolymers composed of the respective monomers are at least 0° C. (monomers a), wherein at least some of the monomers (a) still comprise at least one carboxylic acid (monomers a1), b) 85 to 99 wt %, relative to component A1, of one or more monomers from the group of acrylic acid esters and methacrylic acid esters, each being selected such that the glass transition temperatures T G of the corresponding homopolymers composed of the respective monomers are not higher than −30° C. (monomers b), B) at least one covalently cross-linking bifunctional or polyfunctional crosslinking agent (component B), wherein components A and B in total amount to at least 95 wt % of the polymer compound, and wherein the at least one crosslinking agent is added in a quantity such that the quantity ratio V=n Z /n P of the substance quantity n Z of the crosslinking-active centers of the crosslinking agent to the theoretical substance quantity n P of the macromolecule of polymer component A1 has a value between 0.15 and 0.60, wherein the substance quantity n Z of the crosslinking-active centers of the crosslinking agent is obtained from the mass m V of the crosslinking agent, multiplied by the number f of crosslinking-active centers per crosslinking agent molecule, divided by the molecular weight M v of the crosslinking agent, that is, n Z =f·m V /M V , and the theoretical substance quantity n P of the macromolecule of polymer component A1 is obtained from the mass m P of the polymer component in the pressure-sensitive adhesive compound, divided by the average molecular weight M n,P of said component, that is n P =m P /M n,P .

First claim

The invention claimed is:

1. A double-sided adhesive tape comprising a carrier layer and two outer layers of pressure-sensitive adhesive (PSA),
wherein at least one of the PSAs is the crosslinking product of a polymer composition which comprises at least the following components:
A) a polymer component (component A) comprising 88 to 100 wt. % of one or more polyacrylates (component A1) composed of at least:
a) 1 to 15 wt. %, based on component A1, of one or more monomers having at least one ethylenically unsaturated bond, which are each selected such that the glass transition temperatures T g of the corresponding homopolymers of the respective monomer are at least 0° C. (monomers a), and at least some of the monomers (a) also have at least one carboxylic acid group (monomers a1),
b) 85 to 99 wt. %, based on component A1, of one or more monomers from the group of acrylic esters and methacrylic esters, which are each selected such that the glass transition temperatures T g of the corresponding homopolymers of the respective monomer are not more than −30° C. (monomers b),

B) at least one covalently crosslinking di- or polyfunctional crosslinker (component B),
where components A and B account in total for at least 95 wt. % of the polymer composition, wherein the at least one crosslinker is present in an amount such that the ratio V=n Z /n P of the amount-of-substance n Z of the crosslinking-active centers of the crosslinker to the theoretical amount-of-substance n P of the macromolecules of the polymer component A1 possesses a value of between 0.15 and 0.60, where the amount-of-substance n Z of the crosslinking-active centers of the crosslinker is given by the mass m v of the crosslinker, multiplied by the number f of the crosslinking-active centers per crosslinker molecule, divided by the molar mass M V of the crosslinker, in other words n Z =f·m V /M V , and the theoretical amount-of-substance n P of the macromolecules of the polymer component A1 is given by the mass m P of the polymer component in the PSA, divided by the number-average molar mass M n,P of this component, in other words n P =m P /M n,P .

2. The adhesive tape of claim 1 , wherein the loss factor tan δ (ratio between loss modulus G″ and storage modulus G′) of the PSA at 0.1 rad/s and 85° C., measured by means of DMA, is in a range from 0.35 to 0.75, and the glass transition frequency f g at 25° C., determined by DMA measurement, is more than 5000 rad/s.

3. The adhesive tape of claim 1 wherein the monomers a1 are present at 3 to 5 wt. %, based on component A1.

4. The adhesive tape of claim 1 wherein the crosslinker is a covalently reacting crosslinker.

5. The adhesive tape of claim 1 wherein the proportion V=n Z /n P of the amount-of-substance n Z of the crosslinking-active centers of the crosslinker to the theoretical amount-of-substance n P of the macromolecules of the polymer component A1 possesses a value of between 0.38 and 0.59.

6. The adhesive tape of claim 1 wherein the tape has a thickness of 100 to 300 μm.

7. The adhesive tape of claim 1 wherein the layers of pressure-sensitive adhesive on both sides of the carrier layer are geometrically identical.

8. The adhesive tape of claim 1 wherein the pressure-sensitive adhesives on both sides of the carrier layer are chemically identical.

9. The adhesive of claim 1 wherein at least some of the monomers are selected from the group comprising methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate (monomers a2).

10. The adhesive tape of claim 9 , wherein the monomers a2 are present at up to 10 wt. %, based on component A1.

11. The adhesive tape of claim 1 wherein the polymer component A further comprises up to 12, of a resin component (component A2) having a softening point of 80 to 150° C.

12. The adhesive tape of claim 11 wherein the crosslinker comprises amine functions in the molecule.

13. The adhesive tape of claim 12 wherein the crosslinker istetraglycidyl-meta-xylenediamine.

14. A polymer composition for producing a crosslinked pressure-sensitive adhesive comprising at least the following components:
A) a polymer component (component A) comprising 88 to 100 wt. % of one or more polyacrylates (component A1) composed of at least:
a) 1 to 15 wt. %, based on component A1, of one or more monomers having at least one ethylenically unsaturated bond, which are each selected such that the glass transition temperatures T g of the corresponding homopolymers of the respective monomer are at least 0° C. (monomers a), and at least some of the monomers (a) also have at least one carboxylic acid group (monomers a1),
b) 85 to 99 wt. %, based on component A1, of one or more monomers from the group of acrylic esters and methacrylic esters, which are each selected such that the glass transition temperatures T g of the corresponding homopolymers of the respective monomer are not more than −30° C. (monomers b),

B) at least one di- or polyfunctional crosslinker (component B), where the at least one crosslinker is present in an amount such that the ratio V=n Z /n P of the amount-of-substance n Z of the crosslinking-active centers of the crosslinker to the theoretical amount-of-substance n P of the macromolecules of the polymer component A1 possesses a value of between 0.15 and 0.6,
where the amount-of-substance n Z of the crosslinking-active centers of the crosslinker is given by the mass my of the crosslinker, multiplied by the number f of the crosslinking-active centers per crosslinker molecule, divided by the molar mass My of the crosslinker, in other words n Z =f·m V /M V ,
and the theoretical amount-of-substance n P of the macromolecules of the polymer component A1 is given by the mass m P of the polymer component in the PSA, divided by the number-average molar mass M n,P of this component, in other words n P =m P /M n,P .

Assignees

• Husemann Marc
• Ellringmann Kai
• Kupsky Marco
• Meyer Claus
• Tesa Se

Inventors

• Husemann Marc
• Ellringmann Kai
• Kupsky Marco
• Meyer Claus

Classifications

• Y10T428/2848

  Three or more layers · CPC title

• C09J133/02

  Homopolymers or copolymers of acids; Metal or ammonium salts thereof · CPC title

• C09J7/0217 Primary

  Chemistry & Metallurgy · mapped topic

• C09J7/0246

  Chemistry & Metallurgy · mapped topic

• C09J2201/128

  Chemistry & Metallurgy · mapped topic