Granted Patent B2

US 12,729,328 · App. 17/927,325 · Granted Sep 8, 2026

Inventors: Adrian T. Jung (Kaarst, DE); Boris Ove Alexander Tasch (Düsseldorf, DE); Elisabeth Cura (Düsseldorf, DE); Eike H. Klünker (Kaarst, DE); Peter Bissinger (Diessen, DE); Wolf Steiger (Weil-Petzenhausen, DE); Dirk Hasenberg (Raeren, BE)

Assignee: 3M INNOVATIVE PROPERTIES COMPANY

C09J163/00

Abstract

Claims (54)

1 . A curable precursor of a structural adhesive composition, comprising:

a thermally curable resin comprising epoxy functional groups;

a thermal curing initiator for the thermally curable resin, wherein the thermal curing initiator is selected from the group consisting of aliphatic amines, cycloaliphatic amines, aromatic amines, aromatic structures having one or more amino moieties, polyamines, polyamine adducts, dicyandiamides, and any combination thereof;

a radiation self-polymerizable multi-functional compound; and

a free-radical polymerization initiator for the radiation self-polymerizable multi-functional compound, wherein the free-radical polymerization initiator is selected from the group consisting of Norrish type (I) free-radical polymerization initiators, Norrish type (II) free-radical polymerization initiators, and any combination thereof;

wherein the radiation self-polymerizable multi-functional compound has the following formula:

wherein:

Y is an ethylenically unsaturated group;

each R2 is independently selected from the group consisting of alkylene groups having from 2 to 6 carbon atoms; and

n is an integer selected such that the calculated number average molecular weight of the radiation self-polymerizable multi-functional compound is in a range from 2000 grams per mole to 20000 grams per mole.

2 . A curable precursor according to claim 1 , wherein the free-radical polymerization initiator is initiated at a temperature T1, wherein the thermal curing initiator is initiated at a temperature T2, wherein the temperature T2 is greater than the temperature T1, and wherein the temperature T1 is insufficient to cause initiation of the thermal curing initiator.

3 . A curable precursor according to claim 1 , wherein the epoxy functional groups are glycidyl groups.

4 . A curable precursor according to claim 1 , wherein the amine groups present in the thermal curing initiator are selected from the group consisting of primary amine groups, secondary amine groups, and any combination thereof.

5 . A curable precursor according to claim 1 , which further comprises a thermal curing accelerator for the thermally curable resin, which is selected from the group consisting of polyamines, polyamine adducts, ureas, substituted urea adducts, imidazoles, imidazole salts, imidazolines, aromatic tertiary amines, and any combination thereof.

6 . A curable precursor according to claim 1 , wherein the free-radical polymerization initiator for the radiation self-polymerizable multi-functional compound is selected from the group consisting of benzyl ketals, hydroxy acetophenones, amino acetophenones, aryl alkyl ketones, phosphine oxides, benzoin ethers, substituted acetophenones, substituted alpha-ketols, photoactive oximes, and any combination thereof.

7 . A curable precursor according to claim 1 , which comprises:

from 5 to 40 wt. % of the thermally curable resin;

from 0.1 to 20 wt. % of the thermal curing initiator for the thermally curable resin;

from 0.5 to 20 wt. % of the radiation self-polymerizable multi-functional compound;

from 0.01 to 10 wt. % of the free-radical polymerization initiator for the radiation self-polymerizable multi-functional compound;

optionally, 0.05 to 10 wt. % of a thermal curing accelerator for the thermally curable resin;

optionally, a toughening agent; and

optionally, a thixotropic agent;

wherein the weight percentages are based on the total weight of the curable precursor.

8 . A curable precursor according to claim 1 , wherein each Y is independently selected from the group consisting of a methacrylic group and a acrylic groups.

9 . A curable precursor according to claim 1 , wherein the thermal curing initiator for the thermally curable resin is dicyandiamide.

10 . A curable precursor according to claim 1 , wherein the radiation self-polymerizable multi-functional compound has the following formula:

wherein:

each R2 is independently selected from the group consisting of alkylene groups having from 2 to 6 carbon atoms; and

n is an integer selected such that the calculated number average molecular weight of the radiation self-polymerizable multi-functional compound is in a range from 2000 grams per mole to 20,000 grams per mole.

11 . A process of manufacturing a structural adhesive article, the process comprising:

a) applying a curable precursor according to claim 1 onto a substrate using a printing technique;

b) partially curing the curable precursor by initiating the free-radical polymerization initiator for the radiation self-polymerizable multi-functional compound, thereby forming a partially cured precursor of a structural adhesive article comprising a polymeric material comprising a self-polymerization reaction product of the radiation self-polymerizable multi-functional compound;

c) optionally, substantially fully curing the partially cured precursor of a structural adhesive article by initiating the thermal curing initiator for the thermally curable resin, thereby obtaining a substantially fully cured structural adhesive article; and

d) optionally, removing the partially cured precursor of a structural adhesive article or the substantially fully cured structural adhesive article from the substrate.

12 . A partially cured precursor of a structural adhesive composition, comprising:

a polymeric material comprising a self-polymerization reaction product of a polymerizable material comprising a radiation self-polymerizable multi-functional compound;

optionally, some residual free-radical polymerization initiator for the radiation self-polymerizable multi-functional compound;

a thermally curable resin comprising epoxy functional groups; and

a thermal curing initiator for the thermally curable resin, wherein the thermal curing initiator is selected from the group consisting of aliphatic amines, cycloaliphatic amines, aromatic amines, aromatic structures having one or more amino moieties, polyamines, polyamine adducts, dicyandiamides, and any combination thereof;

wherein the radiation self-polymerizable multi-functional compound has the following formula:

wherein:

Y is an ethylenically unsaturated group;

each R2 is independently selected from the group consisting of alkylene groups having from 2 to 6 carbon atoms; and

n is an integer selected such that the calculated number average molecular weight of the radiation self-polymerizable multi-functional compound is in a range from 2000 grams per mole to 20000 grams per mole; and

wherein the thermally curable resin is uncured and is embedded into the polymeric material comprising the self-polymerization reaction product of a polymerizable material comprising a radiation self-polymerizable multi-functional compound.

13 . A partially cured precursor according to claim 12 , wherein the epoxy functional groups are glycidyl groups.

14 . A partially cured precursor according to claim 12 , wherein the amine groups present in the thermal curing initiator are selected from the group consisting of primary amine groups, secondary amine groups, and any combination thereof.

15 . A partially cured precursor according to claim 12 , which further comprises a thermal curing accelerator for the thermally curable resin, which is selected from the group consisting of polyamines, polyamine adducts, ureas, substituted urea adducts, imidazoles, imidazole salts, imidazolines, aromatic tertiary amines, and any combination thereof.

16 . A partially cured precursor according to claim 12 , wherein the thermal curing initiator for the thermally curable resin is dicyandiamide.

17 . The partially cured precursor according to claim 12 , wherein the radiation self-polymerizable multi-functional compound has the following formula:

wherein:

each R2 is independently selected from the group consisting of alkylene groups having from 2 to 6 carbon atoms; and

n is an integer selected such that the calculated number average molecular weight of the radiation self-polymerizable multi-functional compound is in a range from 2000 grams per mole to 20,000 grams per mole.

Assignments (1)

Priority Claims (1)

Continuity (1)

References Cited (132)