Crosslinking composition having a polyrotaxane and a compound having two or more oxirane groups and/or oxetane groups
The present invention provides a material of high toughness that could not have been provided by an epoxy resin alone. The present invention provides a crosslinking composition having (A) one or more polyrotaxanes in which end-capping groups which prevent dissociation of the linear group are situated at both ends of a pseudo-polyrotaxane formed by inclusion of a linear molecule in the opening of a cyclic molecule by being threaded therethrough, the polyrotaxane having on the cyclic molecule a functional group that is capable of reacting with the oxirane group and/or the oxetane group, the functional group being one or more selected from the group consisting of carboxylic acid groups, carboxylate groups, primary amine groups, secondary amino groups, tertiary amino groups, phenol groups, the oxirane group, and the oxetane group, and (B) a compound having two or more oxirane groups and/or oxetane groups; and a crosslinked product employing the composition.
1. A crosslinked body formed from a crosslinking composition, which comprises:
A. a polyrotaxane comprising a pseudopolyrotaxane, which has a linear molecule and a cyclic molecule(s) in which the linear molecule is included in a cavity (cavities) of the cyclic molecule(s) in a skewered manner, and capping groups, each of which locates at each end of the pseudopolyrotaxane in order to prevent the dissociation of the cyclic molecule(s), wherein the cyclic molecule(s) has (have) a functional group capable of reacting with an oxirane group and/or an oxetane group, the functional group is one or more selected from the group consisting of a carboxylic acid group, a carboxylate group, a primary amine group, a secondary amine group, a phenol group, an oxirane group, and an oxetane group; and
B. a compound having two or more oxirane and/or oxetane groups, and
wherein the functional group is bound to the cyclic molecule via a spacer,
the spacer comprises a polymeric portion having 1.5 to 10 of an average repeating unit, and
the weight ratio of (polyrotaxane A)/(compound B) is 0.15 or less,
the crosslinked body has toughness with 25 mm or less of a minimum mandrel diameter, when cracks are caused by bending the crosslinked body in a method in accordance with JIS K5600-5-1; and
the crosslinking composition further comprises:
C. a crosslinking agent or crosslinking initiator.
2. A scaling material comprising the crosslinked body according to claim 1 .
3. A coating film comprising the crosslinked body according to claim 1 .
4. A method for producing a crosslinked body, comprising the steps of:
a) preparing a polyrotaxane A comprising a pseudopolyrotaxane, which has a linear molecule and a cyclic molecule(s) in which the linear molecule is included in a cavity (cavities) of the cyclic molecule(s) in a skewered manner, and capping groups, each of which locates at each end of the pseudopolyrotaxane in order to prevent the dissociation of the cyclic molecule(s), wherein the cyclic molecule(s) has (have) a functional group capable of reacting with an oxirane group and/or an oxetane group, the functional group is one or more selected from the group consisting of a carboxylic acid group, a carboxylate group, a primary amine group, a secondary amine group, a phenol group, an oxirane group, and an oxetane group;
b) preparing a compound B having two or more oxirane and/or oxetane groups; and
c) mixing the polyrotaxane A and the compound B, and heating the mixture, to crosslink the polyrotaxane A and the compound B; and
d) preparing a crosslinking agent or crosslinking initiator C, wherein the crosslinking agent or crosslinking initiator C is mixed together with the polyrotaxane A and the compound B in the step c) and the mixture is heated, to crosslink the polyrotaxane A and the compound B; and
e) binding the functional group via a spacer to the cyclic molecule, wherein the spacer comprises a polymeric portion having 1.5 to 10 of an average repeating unit, and
wherein the weight ratio of (polyrotaxane A)/(compound B) is 0.15 or less,
thereby to obtain the crosslinked body, and
wherein the crosslinked body has toughness with 25 mm or less of a minimum mandrel diameter, when cracks are caused by bending the crosslinked body in a method in accordance with JIS K5600-5-1.
5. The method according to claim 4 ,
wherein the crosslinking agent or crosslinking initiator C is:
C1. at least one selected from the group consisting of phenol resins, acid anhydrides, polycarboxylic acid compounds, and primary amine compound; or
C2. at least one selected from the group consisting of imidazoles, secondary amines, and tertiary amines.
6. The method according to claim 4 , wherein the step a) comprises:
a)-1) a step of preparing a polyrotaxane comprising a pseudopolyrotaxane, which has a linear molecule and a cyclic molecule(s) in which the linear molecule is included in a cavity (cavities) of the cyclic molecule(s) in a skewered manner, and capping groups, each of which locates at each end of the pseudopolyrotaxane in order to prevent the dissociation of the cyclic molecule(s);
a)-2) a step of preparing a second compound having a source of the functional group which is one or more selected from the group consisting of a carboxylic acid group, a carboxylate group, a primary amino group, a secondary amino group, a phenol group, an oxirane group, and an oxetane group; and
a)-3) a step of reacting the polyrotaxane and the second compound, to obtain the polyrotaxane A having the functional group on the cyclic molecule.
7. The crosslinked body according to claim 1 , wherein C. the crosslinking agent or crosslinking initiator is:
C1. at least one selected from the group consisting of phenol resins, acid anhydrides, polycarboxylic acid compounds, and primary amine compounds; or
C2. at least one selected from the group consisting of imidazoles, secondary amines, and tertiary amines.