Provided is an alkyldiphenylmethane protective agent, which can prevent solidification or insolubilization of a compound by protecting a functional group of the compound to achieve easy separation and purification after a reaction. An alkyldiphenylmethane compound represented by general formula (1): ##STR00001## wherein Y represents —OR.sup.19 (wherein R.sup.19 represents a hydrogen atom or an active ester-type protecting group), —NHR.sup.20 (wherein R.sup.20 represents a hydrogen atom, a C.sub.1-6 linear or branched alkyl group, or an aralkyl group), isocyanate group, an azide group, or a halogen atom, Z represents a C.sub.1-4 linear or branched alkyl group, an alkenyl group, or a cycloalkyl group, at least one of R.sup.1 to R.sup.10 represents a group represented by formula (2):
—O—R.sup.11—X-A  (2) and the others each independently represent a hydrogen atom, a halogen atom, a C.sub.1-4 alkyl group, or a C.sub.1-4 alkoxy group; R.sup.11 represents a C.sub.1-16 linear or branched alkylene group; X represents O or CONR.sup.21 (wherein R.sup.21 represents a hydrogen atom or a C.sub.1-4 alkyl group); and A represents, for example, a group represented by formula (3): ##STR00002## wherein R.sup.12, R.sup.13, and R.sup.14 may be the same or different and each independently represent a C.sub.1-6 linear or branched alkyl group or an optionally substituted aryl group; R.sup.15 represents a single bond or a C.sub.1-3 linear or branched alkylene group; and R.sup.16, R.sup.17, and R.sup.18 each independently represent a C.sub.1-3 linear or branched alkylene group.

Provided is an alkyldiphenylmethane protective agent, which can prevent solidification or insolubilization of a compound by protecting a functional group of the compound to achieve easy separation and purification after a reaction. An alkyldiphenylmethane compound represented by general formula (1): ##STR00001## wherein Y represents —OR.sup.19 (wherein R.sup.19 represents a hydrogen atom or an active ester-type protecting group), —NHR.sup.20 (wherein R.sup.20 represents a hydrogen atom, a C.sub.1-6 linear or branched alkyl group, or an aralkyl group), isocyanate group, an azide group, or a halogen atom, Z represents a C.sub.1-4 linear or branched alkyl group, an alkenyl group, or a cycloalkyl group, at least one of R.sup.1 to R.sup.10 represents a group represented by formula (2):
—O—R.sup.11—X-A  (2) and the others each independently represent a hydrogen atom, a halogen atom, a C.sub.1-4 alkyl group, or a C.sub.1-4 alkoxy group; R.sup.11 represents a C.sub.1-16 linear or branched alkylene group; X represents O or CONR.sup.21 (wherein R.sup.21 represents a hydrogen atom or a C.sub.1-4 alkyl group); and A represents, for example, a group represented by formula (3): ##STR00002## wherein R.sup.12, R.sup.13, and R.sup.14 may be the same or different and each independently represent a C.sub.1-6 linear or branched alkyl group or an optionally substituted aryl group; R.sup.15 represents a single bond or a C.sub.1-3 linear or branched alkylene group; and R.sup.16, R.sup.17, and R.sup.18 each independently represent a C.sub.1-3 linear or branched alkylene group.

A method of producing a thiourethane resin raw material, the method including comprising the step of generating the thiourethane resin raw material by reacting a thiourethane resin and an active hydrogen compound with each other.

A method of producing a thiourethane resin raw material, the method including comprising the step of generating the thiourethane resin raw material by reacting a thiourethane resin and an active hydrogen compound with each other.

The embodiments provide processes for preparing a diisocyanate composition and an optical lens, which are excellent in yield and quality with mitigated environmental problems by using a solid triphosgene composition instead of phosgene gas in the process of preparing a diisocyanate from a diamine through a hydrochloride thereof and by controlling the content of a decomposition product in a triphosgene composition, the b* value according to CIE color coordinate of the triphosgene composition in an organic solvent, or the content of water in the triphosgene.

The embodiments provide processes for preparing a diisocyanate composition and an optical lens, which are excellent in yield and quality with mitigated environmental problems by using a solid triphosgene composition instead of phosgene gas in the process of preparing a diisocyanate from a diamine through a hydrochloride thereof and by controlling the content of a decomposition product in a triphosgene composition, the b* value according to CIE color coordinate of the triphosgene composition in an organic solvent, or the content of water in the triphosgene.

A method for the preparation of isocyanates in which: (i) a first organosilicon compound having at least one silicon atom Si.sup.1 and a unit of formula G-I bound thereto

##STR00001##

is converted to a third organosilicon compound having a unit of formula G-II

##STR00002##

by silylation of the NH group of the unit of formula G-I with a second organosilicon compound having one silicon atom Si.sup.2; and (ii) the third organosilicon compound is reacted to an isocyanate by thermolysis, whereby the unit of formula G-II is converted to an isocyanate group.

A method for the preparation of isocyanates in which: (i) a first organosilicon compound having at least one silicon atom Si.sup.1 and a unit of formula G-I bound thereto

##STR00001##

is converted to a third organosilicon compound having a unit of formula G-II

##STR00002##

by silylation of the NH group of the unit of formula G-I with a second organosilicon compound having one silicon atom Si.sup.2; and (ii) the third organosilicon compound is reacted to an isocyanate by thermolysis, whereby the unit of formula G-II is converted to an isocyanate group.

A xylylene diisocyanate, a compound represented by the following chemical formula (1), and a compound represented by the following chemical formula (2) are contained in a xylylene diisocyanate composition.

##STR00001##

A xylylene diisocyanate, a compound represented by the following chemical formula (1), and a compound represented by the following chemical formula (2) are contained in a xylylene diisocyanate composition.

##STR00001##