A curable composition includes a (meth)acrylic acid ester polymer (A), wherein the (meth)acrylic acid ester polymer (A) includes a monomer and a macromonomer (a). The monomer includes a reactive silicon group represented by the general formula (1): SiR.sup.1.sub.aX.sub.3-a (1) (in the formula, R.sup.1 represents a substituted or unsubstituted hydrocarbon group with 1 to 20 carbon atoms, X each independently represents a hydroxyl group or a hydrolyzable group, and a represents 0 or 1.) and a polymerizable unsaturated group. The macromonomer (a) is a (meth)acrylic acid ester polymer having a polymerizable unsaturated group.

The objectionable odor of one component condensation curable organopolysiloxane compositions is eliminated by replacing all or the most substantial part of water scavenger vinyltrimethoxysilane with a phenyltrialkoxysilane, without compromising storage or curing properties.

The objectionable odor of one component condensation curable organopolysiloxane compositions is eliminated by replacing all or the most substantial part of water scavenger vinyltrimethoxysilane with a phenyltrialkoxysilane, without compromising storage or curing properties.

RTV-1 compositions, despite containing conventional alkoxysilyl-terminated polymers, exhibit rapid cure and excellent physical properties when they further contain silicone resins, and employ metal, amidine, or guanidine curing catalysts C1 and amine-containing cocatalysts C2 in specific mole ratios.

RTV-1 compositions, despite containing conventional alkoxysilyl-terminated polymers, exhibit rapid cure and excellent physical properties when they further contain silicone resins, and employ metal, amidine, or guanidine curing catalysts C1 and amine-containing cocatalysts C2 in specific mole ratios.

The use of an amidine of formula (I) and/or a conversion product thereof as a catalyst for the crosslinking of a composition based on silane group-containing polymers. The amidine of formula (I) and the conversion products thereof are essentially odourless at room temperature and non-volatile and accelerate the crosslinking of the composition very well without impairing the storage stability of the composition, and are very compatible in the composition. As a result, the compositions do not have a tendency to separate, migrate or evaporate the catalyst.

The use of an amidine of formula (I) and/or a conversion product thereof as a catalyst for the crosslinking of a composition based on silane group-containing polymers. The amidine of formula (I) and the conversion products thereof are essentially odourless at room temperature and non-volatile and accelerate the crosslinking of the composition very well without impairing the storage stability of the composition, and are very compatible in the composition. As a result, the compositions do not have a tendency to separate, migrate or evaporate the catalyst.

Provided is a curable composition that can, when cured, form a cured product having adhesiveness and adhesion to an adherend at excellent levels. The curable composition contains a polyorganosilsesquioxane and one of (A) a compound represented by Formula (X); and (B) a polymerization stabilizer, where Formula (X) is expressed as follows:

##STR00001##

wherein r1 represents an integer from 4 to 20; L represents a group containing epoxy, oxetanyl or vinyl ether group; R.sup.11 and R.sup.12 each represent an optionally substituted hydrocarbon group; s1 represents an integer from 1 to 3; t1 represents an integer from 0 to 2, where s1 plus t1 equals 3; and R.sup.13 and R.sup.14 are selected from hydrogen and an optionally substituted hydrocarbon group. The polyorganosilsesquioxane has a number-average molecular weight of 1000 to 3000 and a molecular-weight dispersity of 1.0 to 3.0, includes a constitutional unit represented by Formula (1), has a ratio of a constitutional unit represented by Formula (I) to a constitutional unit represented by Formula (II) of 5 or more, and has a total proportion of the constitutional unit represented by Formula (1) and a constitutional unit represented by Formula (4) of 55 to 100 mole percent of all siloxane constitutional units. [R.sup.1SiO.sub.3/2] (1), [R.sup.aSiO.sub.3/2] (I), [R.sup.bSiO.sub.2/2(OR.sup.c)] (II), [R.sup.1SiO.sub.2/2(OR.sup.c)] (4), where R.sup.1 represents an epoxy-containing group; R.sup.a and R.sup.b are each selected from an epoxy-containing group, substituted or unsubstituted aryl, substituted or unsubstituted aralkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, and hydrogen; and R.sup.c is selected from hydrogen and C.sub.1-C.sub.4 alkyl.

Provided is a curable composition that can, when cured, form a cured product having adhesiveness and adhesion to an adherend at excellent levels. The curable composition contains a polyorganosilsesquioxane and one of (A) a compound represented by Formula (X); and (B) a polymerization stabilizer, where Formula (X) is expressed as follows:

##STR00001##

wherein r1 represents an integer from 4 to 20; L represents a group containing epoxy, oxetanyl or vinyl ether group; R.sup.11 and R.sup.12 each represent an optionally substituted hydrocarbon group; s1 represents an integer from 1 to 3; t1 represents an integer from 0 to 2, where s1 plus t1 equals 3; and R.sup.13 and R.sup.14 are selected from hydrogen and an optionally substituted hydrocarbon group. The polyorganosilsesquioxane has a number-average molecular weight of 1000 to 3000 and a molecular-weight dispersity of 1.0 to 3.0, includes a constitutional unit represented by Formula (1), has a ratio of a constitutional unit represented by Formula (I) to a constitutional unit represented by Formula (II) of 5 or more, and has a total proportion of the constitutional unit represented by Formula (1) and a constitutional unit represented by Formula (4) of 55 to 100 mole percent of all siloxane constitutional units. [R.sup.1SiO.sub.3/2] (1), [R.sup.aSiO.sub.3/2] (I), [R.sup.bSiO.sub.2/2(OR.sup.c)] (II), [R.sup.1SiO.sub.2/2(OR.sup.c)] (4), where R.sup.1 represents an epoxy-containing group; R.sup.a and R.sup.b are each selected from an epoxy-containing group, substituted or unsubstituted aryl, substituted or unsubstituted aralkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, and hydrogen; and R.sup.c is selected from hydrogen and C.sub.1-C.sub.4 alkyl.

The use of a catalyst of the formula (I) for the crosslinking of a curable composition. The catalyst of the formula (I) contains at least one aliphatic guanidine group. It is substantially odourless and nonvolatile at room temperature and accelerates the crosslinking of curable compositions very efficiently, without impairing the storage stability thereof. It is particularly suitable for compositions based on polymers containing silane groups, where it has very good compatibility, as a result of which such compositions do not have a tendency to separation or migration or evaporation of the catalyst.