Printable curable mixtures and cured compositions

Patent metadata

Field	Value
Publication number	US-11655403-B2
Application number	US-201816621276-A
Country	US
Kind code	B2
Filing date	Jun 27, 2018
Priority date	Jun 30, 2017
Publication date	May 23, 2023
Grant date	May 23, 2023

Abstract

A curable mixture, a partially cured composition, a cured composition, an article containing either the partially cured composition or the cured composition, and a method of bonding two substrates are provided. The partially cured composition functions as a pressure-sensitive adhesive while the cured composition functions as a structural or semi-structural adhesive. The curable mixture can be applied to a first substrate by printing or dispensing, if desired.

First claim

What is claimed is:

1. A curable mixture comprising:
(a) a first curable composition comprising
(1) a (meth)acrylate copolymer having at least two pendant (meth)acryloyl groups, the (meth)acrylate copolymer having a weight average molecular weight in a range of 35,000 to 300,000 Daltons;
(2) a crosslinking monomer having at least two (meth)acryloyl groups, wherein the crosslinking monomer is present in an amount range from 1 to 10 weight percent based on a total weight of the curable mixture; and
(3) a free radical photoinitiator that is sensitive to actinic radiation of a first wavelength that is at least 380 nanometers; and

(b) a second curable composition that is miscible with the first curable composition and that is combined with the first curable composition only after formation of the (meth)acrylate copolymer having at least two pendant (meth)acryloyl groups, the second curable composition comprising
(1) an epoxy resin;
(2) a polyether polyol; and
(3) a photo-acid generator that is sensitive to actinic radiation of a second wavelength that is less than 380 nanometers and that is not sensitive to actinic radiation of the first wavelength;

wherein the first curable composition but not the second curable composition is curable at the first wavelength and wherein the second curable composition is cured after the first curable composition, and
wherein the curable mixture is free or have less than 0.5 weight percent of active hydrogen-containing compounds having an amino or mercapto group that can react with epoxy resin; and
wherein the curable mixture is printable.

2. The curable mixture of claim 1 , wherein the curable mixture has a shear viscosity no greater than 150 Pascal-seconds at a shear rate of 100 sec −1 when measured using a parallel plate viscometer.

3. The curable mixture of claim 1 comprising:
5 to 75 weight percent of the (meth)acrylate copolymer having at least two pendant (meth)acryloyl groups;
1 to 10 weight percent of the crosslinking monomer having at least two (meth)acryloyl groups;
0.01 to 5 weight percent of the free radical photoinitiator;
10 to 80 weight percent of the epoxy resin;
2 to 25 weight percent of the polyether polyol;
0.5 to 3 weight percent of the photo-acid generator; and
0 to less than 0.5 weight percent of active hydrogen-containing compounds having an amino or mercapto group that can react with epoxy resin.

4. A partially cured composition of a curable mixture that is printable, the partially cured composition comprising:
(a) a first cured composition that is a reaction product of a first curable composition comprising
(1) a (meth)acrylate copolymer having at least two pendant (meth)acryloyl groups, the (meth)acrylate copolymer having a weight average molecular weight in a range of 35,000 to 300,000 Daltons;
(2) a crosslinking monomer having at least two (meth)acryloyl groups, wherein the crosslinking monomer is present in an amount range from 1 to 10 weight percent based on a total weight of the curable mixture; and
(3) a free radical photoinitiator that is sensitive to actinic radiation of a first wavelength that is at least 380 nanometers; and

(b) a second curable composition that is miscible with the first curable composition and that is combined with the first curable composition only after formation of the (meth)acrylate copolymer having at least two pendant (meth)acryloyl groups, the second curable composition comprising
(1) an epoxy resin;
(2) a polyether polyol; and
(3) a photo-acid generator that is sensitive to actinic radiation of a second wavelength that is less than 380 nanometers and that is not sensitive to actinic radiation of the first wavelength,

wherein the curable mixture is free or have less than 0.5 weight percent of active hydrogen-containing compounds having an amino or mercapto group that can react with epoxy resin.

5. The partially cured composition of claim 4 , wherein the partially cured composition is a pressure-sensitive adhesive.

6. A first article comprising:
a first substrate or a first release liner; and
a partially cured composition of a curable mixture that is printable, the partially cured composition positioned adjacent to the first substrate or adjacent to the first release liner, the partially cured composition comprising
(a) a first cured composition that is a reaction product of a first curable composition comprising
(1) a (meth)acrylate copolymer having at least two pendant (meth)acryloyl groups, the (meth)acrylate copolymer having a weight average molecular weight in a range of 35,000 to 300,000 Daltons;
(2) a crosslinking monomer having at least two (meth)acryloyl groups, wherein the crosslinking monomer is present in an amount range from 1 to 10 weight percent based on a total weight of the curable mixture; and
(3) a free radical photoinitiator that is sensitive to actinic radiation of a first wavelength that is at least 380 nanometers; and

(b) a second curable composition that is miscible with the first curable composition and that is combined with the first curable composition only after formation of the (meth)acrylate copolymer having at least two pendant (meth)acryloyl groups, the second curable composition comprising
(1) an epoxy resin;
(2) a polyether polyol; and
(3) a photo-acid generator that is sensitive to actinic radiation of a second wavelength that is less than 380 nanometers and that is not sensitive to actinic radiation of the first wavelength,

wherein the curable mixture is free or have less than 0.5 weight percent of an active hydrogen-containing compounds having an amino or mercapto group that can react with epoxy resin.

7. The first article of claim 6 , wherein the partially cured composition is positioned between the first substrate and a second release liner.

8. The first article of claim 6 , wherein the partially cured composition is positioned between the first release liner and a second release liner.

9. The first article of claim 6 , wherein the partially cured composition is a pressure-sensitive adhesive.

10. A method of bonding, the method comprising:
providing a curable mixture that is printable, the curable mixture comprising
(a) a first curable composition comprising
(1) a (meth)acrylate copolymer having at least two pendant (meth)acryloyl groups, the (meth)acrylate copolymer having a weight average molecular weight in a range of 35,000 to 300,000 Daltons;
(2) a crosslinking monomer having at least two (meth)acryloyl groups, wherein the crosslinking monomer is present in an amount range from 1 to 10 weight percent based on a total weight of the curable mixture; and
(3) a free radical photoinitiator that is sensitive to actinic radiation of a first wavelength that is at least 380 nanometers; and

(b) a second curable composition that is miscible with the first curable composition and that is combined with the first curable composition only after formation of the (meth)acrylate copolymer having at least two pendant (meth)acryloyl groups, the second curable composition comprising
(1) an epoxy resin;
(2) a polyether polyol; and
(3) a photo-acid generator that is sensitive to actinic radiation of a second wavelength that is less than 380 nanometers and that is not sensitive to actinic radiation of the first wavelength,

wherein the curable mixture is free or have less than 0.5 weight percent of active hydrogen-containing compounds having an amino or mercapto group that can react with epoxy resin;
applying the curable mixture to a first substrate or to a first release liner and exposing the curable mixture to the first wavelength of actinic radiation to form a partially cured composition adjacent to the first substrate or

Assignees

• 3M Innovative Properties Company

Inventors

• Volp Kelly A
• Shafer Kathleen S
• Behling Ross E
• Gilman Ann M
• Ellis Mark F
• Smith Matthew R D
• Hedegaard Aaron T
• Jiang Xiaoming
• Anderson Cyrus A

Classifications

• C08L33/14 Primary

  of esters containing halogen, nitrogen, sulfur, or oxygen atoms in addition to the carboxy oxygen · CPC title

• C09J7/30

  characterised by the adhesive composition · CPC title

• C09J7/40

  characterised by release liners · CPC title

• C09J133/14 Primary

  of esters containing halogen, nitrogen, sulfur or oxygen atoms in addition to the carboxy oxygen · CPC title

• C09J2433/00

  Presence of (meth)acrylic polymer · CPC title