US 11,891,507 B2
Thermosetting epoxy resin composition having low curing temperature and good storage stability
Noah Munzinger, Zürich (CH); and Dominique Gallo, Otelfingen (CH)
Assigned to SIKA TECHNOLOGY AG, Baar (CH)
Appl. No. 17/287,067
Filed by SIKA TECHNOLOGY AG, Baar (CH)
PCT Filed Dec. 23, 2019, PCT No. PCT/EP2019/086914
§ 371(c)(1), (2) Date Apr. 20, 2021,
PCT Pub. No. WO2020/141130, PCT Pub. Date Jul. 9, 2020.
Claims priority of application No. 19150161 (EP), filed on Jan. 3, 2019.
Prior Publication US 2021/0355316 A1, Nov. 18, 2021
Int. Cl. C08L 63/04 (2006.01); C08G 59/40 (2006.01); C09J 7/35 (2018.01); C08F 136/06 (2006.01); C08G 18/75 (2006.01); C08G 59/24 (2006.01); C08G 59/46 (2006.01); C08L 71/02 (2006.01); C08L 75/04 (2006.01); C09J 163/04 (2006.01)
CPC C08L 63/04 (2013.01) [C08F 136/06 (2013.01); C08G 18/755 (2013.01); C08G 59/245 (2013.01); C08G 59/4021 (2013.01); C08G 59/4035 (2013.01); C08G 59/46 (2013.01); C08L 71/02 (2013.01); C08L 75/04 (2013.01); C09J 7/35 (2018.01); C09J 163/04 (2013.01); C08L 2205/03 (2013.01); C09J 2463/00 (2013.01)] 14 Claims
 
1. A thermosetting epoxy resin composition comprising
a) at least one epoxy resin A having an average of more than one epoxy group per molecule;
b) at least one curing agent B for epoxy resins, where the curing agent B is a dihydrazide selected from the group consisting of glutaric dihydrazide, adipic dihydrazide and pimelic dihydrazide; and
c) at least one accelerator C of the formula (Ia) or (Ib)

OG Complex Work Unit Chemistry
where R1 is H or an n-valent aliphatic, cycloaliphatic or araliphatic radical;
R2 and R3 are
either
each independently an alkyl group or aralkyl group;
or
together are a divalent aliphatic radical which has 3 to 20 carbon atoms and is part of an optionally substituted heterocyclic ring having 5 to 8 ring atoms;
R1′ is an n′-valent aliphatic, cycloaliphatic or araliphatic radical;
R2′ is an alkyl group or aralkyl group or alkylene group;
R3′ is independently H or an alkyl group or aralkyl group; and
n and n′ each have a value of 1 to 4,
wherein when R1 is not H, R1 does not include an aromatic group bonded directly to a nitrogen atom of Formula (Ia),
wherein a ratio of a proportion of epoxy groups of the epoxy resin A in a mol/a proportion of dihydrazide in mol is 3-5,
wherein a ratio of a proportion of accelerator C in grams per mole of epoxy groups of the epoxy resin A is 0.08-0.15 g/mol of epoxy groups, and
wherein the epoxy resin composition has a viscosity at 25° C. of 500 to 3000 Pa*s.