Silane/urea compound as a heat-activatable curing agent for epoxide resin compositions

1. A thermosetting epoxy resin composition comprising:

at least one epoxy resin EH having, on average, more than one epoxide group per molecule;

an inorganic filler containing at least one metal atom selected from the group consisting of Ca atoms, Si atoms, Al atoms, and mixtures thereof; and

at least one silane of formula (I);

wherein A is an optionally branched alkylene group containing 1 to 4 C atoms, or a phenylene group;

wherein Z 1 is H or an alkyl group containing 1 to 4 C atoms;

wherein Z 2 is H, a phenyl group, or an alkyl group containing 1 to 8 C atoms;

wherein Z 3 is:

H,

a monofunctional aromatic or cycloaliphatic or aliphatic group containing 1 to 8 C atoms, which optionally contains at least one carboxylate, nitrile, nitro, phosphonate, or sulfonic or sulfonate group, or

a group having a formula of A-Si(Z 2 ) 3-a (OZ 1 ) a ;

wherein Z 4 is H or a monofunctional aromatic or cycloaliphatic or aliphatic group containing 1 to 8 C atoms;

wherein Z 5 is:

a b-functional aromatic or araliphatic or cycloaliphatic or aliphatic group containing 1 to 40 C atoms, or

a group having a formula of A-Si(Z 2 ) 3-a (OZ 1 ) a ;

wherein X is 0 or S;

wherein a is 1 or 2 or 3; and

wherein b is 1 or 2 or 3 or 4;

with the proviso that either Z 3 or Z 4 is H.

2. The thermosetting epoxy resin composition of claim 1 , wherein the silane of formula (I) is present in the thermosetting epoxy resin composition in amount of from 0.001-20% by weight, relative to the weight of the thermosetting epoxy resin composition.

3. The thermosetting epoxy resin composition of claim 1 , further comprising at least one heat-activatable curing agent B selected from the group consisting of dicyandiamide, guanamine, guanidine, aminoguanidine, a substituted urea, a phenyldimethyl urea, imidazoles, imidazole salts, imidazolines, amine complexes and derivatives thereof.

4. The thermosetting epoxy resin composition of claim 1 , wherein the thermosetting epoxy resin composition further comprises at least one impact modifier D.

5. The thermosetting epoxy resin composition of claim 4 , wherein the impact modifier D is selected from the group consisting of blocked polyurethane polymers, liquid rubbers, epoxy resin-modified liquid rubbers, block copolymers, and core-shell polymers.

6. The thermosetting epoxy resin composition of claim 5 , wherein the impact modifier D is a blocked polyurethane polymer of formula (IV)

wherein:

Y 1 is a linear or branched polyurethane polymer PU1, terminated by m+m′ isocyanate groups, after removal of all end-position isocyanate groups;

Y 2 is independently a blocking group that cleaves at a temperature above 100° C.;

Y 3 is independently a group of formula (IV′)

wherein R 4 is a radical of an aliphatic, cycloaliphatic, aromatic, or araliphatic epoxy, containing a primary or secondary hydroxyl group, after removal of the hydroxide and epoxy groups;

wherein p is 1, 2, or 3, and

wherein m and m′ each stand for an integer between 0 and 8, with the proviso that a value of m+m′ is from 1 to 8.

7. A method for the adhesive bonding of heat-stable substrates, the method comprising:

i) applying the thermosetting epoxy resin composition of claim 1 to a surface of a first heat-stable substrate S1;

ii) contacting the applied thermosetting epoxy resin composition with the surface of second heat-stable substrate S2;

iii) heating the contacted thermosetting epoxy resin composition to a temperature of 100-220° C.;

wherein substrate S2 is composed of a material that is identical to or different from substrate S1.

8. A cured epoxy resin composition obtained by heating the thermosetting epoxy resin composition claim 1 .