Curatives

A clathrate comprising a host compound and a guest compound in which the host compound is selected from compounds of general formula

• wherein X, X1, X2 and X3 are independently selected from S or O and at least one of Y1 and Y2 is present;
• and wherein when both Y1 and Y2 are present they may be the same or different and are selected from NHR or OH where R is selected from H or a hydrocarbyl group, and wherein;
• the guest compound comprises at least one compound selected from the group consisting of
• in which R1 represents a hydrogen atom, a C1-C10 alkyl group, an aryl group, an arylalkyl group, or a cyanoethyl group, and R2 to R4 each independently represent a hydrogen atom, a nitro group, a halogen atom, a C1-C20 alkyl group, a C1-C20 alkyl group substituted with a hydroxy group, an aryl group, an arylalkyl group, or a C1-C20 acyl group, and wherein;
• the mol ratio of the host compound to the guest compound is from 0.95 to 1.4, and wherein;
• the average particle size D50 of the clathrate as measured by laser diffraction (ASTM D4464) is, in the range of from 5 to 40 μm, and wherein;
• and
• the guest component of the clathrate comprises an accelerator or curative compound having an amino group.