DESCRIPTION
Title of Invention:
METHOD OF PRODUCING THIOURETHANE RESIN RAW MATERIAL AND
APPLICATION THEREOF
Technical Field
[0001] The present disclosure relates to: a method of producing a thiourethane resin raw
material; and an application thereof.
Background Art
[0002] Plastic lenses, which are resin-containing lenses, are lightweight, hardly breakable,
and dyeable as compared to inorganic lenses; therefore, in recent years, the use of plastic
lenses as eyeglass lenses, camera lenses, and the like has been rapidly increased.
For example, various studies have been conducted on thiourethane resin-containing
lenses (see, for example, the following Patent Documents 1 to 3).
[0003] Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No. S63-46213
Patent Document 2: JP-A No. H2-270859
Patent Document 3: JP-A No. H7-252207
SUMMARY OF THE INVENTION
Technical Problem
[0004] As raw materials for the production of a thiourethane resin (hereinafter, also referred
to as "thiourethane resin raw materials"), a polythiol composition and a polyisocyanate
compound are usually used. The polyisocyanate compound is produced from, for example, a
polyamine compound. The polyamine compound that is a raw material of the
polyisocyanate compound also falls under "thiourethane resin raw materials" (i.e., raw
materials for the production of a thiourethane resin). Further, a compound used as a raw
material of this polyamine compound (e.g., a polyurea compound or a polycarbamate
compound) also falls under "thiourethane resin raw materials".
[0005] Thiourethane resin-containing lenses contain a foreign material (i.e., a component
other than the thiourethane resin) in some cases.
A lens that contains a thiourethane resin and a foreign material is produced by
milling a formed body obtained by molding a composition containing the thiourethane resin
and the foreign material (hereinafter, also referred to as "composition X"). In this process, a
large amount of milling swarf containing the thiourethane resin and the foreign material is
generated. Conventionally, such milling swarf generated in a large amount is simply
disposed without being effectively utilized.
However, from the standpoint of effective utilization of materials (i.e., recycle), a
technology for producing a thiourethane resin raw material using, as a starting material, the
thiourethane resin contained in such milling swarf is desired. The resulting thiourethane
2
resin raw material can be used as a raw material of a new thiourethane resin.
Further, a technology for producing a thiourethane resin raw material using a
thiourethane resin as a starting material, which is not limited to the use of a thiourethane resin
contained in a milling swarf as a starting material, is desired.
[0006] An object of one aspect of the disclosure is to provide: a method of producing a
thiourethane resin raw material, by which a thiourethane resin raw material can be produced
using a composition X containing a thiourethane resin and a foreign material as a starting
material; and an application thereof.

CLAIMS
Claim 1. A method of producing a thiourethane resin raw material, the method
comprising a reaction step of generating a thiourethane resin raw material by contacting a
composition X, which comprises a thiourethane resin and a foreign material, and an active
hydrogen compound with each other, and thereby reacting the thiourethane resin in the
composition X, and the active hydrogen compound, with each other.
Claim 2. The method of producing a thiourethane resin raw material according to
claim 1, wherein the foreign material comprises at least one selected from the group
consisting of a resin other than the thiourethane resin, a polymerization catalyst, a metal, a
UV absorber, an internal mold release agent, a plasticizer, a dye, a machine oil, and water.
Claim 3. The method of producing a thiourethane resin raw material according to
claim 1 or 2, wherein the thiourethane resin raw material comprises at least one selected from
the group consisting of a polythiol composition, a polyurea compound, a polycarbamate
compound, a polyamine compound, a polyisocyanate compound, and a polyurethane
compound.
Claim 4. The method of producing a thiourethane resin raw material according to any
one of claims 1 to 3, wherein the active hydrogen compound is at least one selected from the
group consisting of an amine compound and an alcohol compound.
Claim 5. The method of producing a thiourethane resin raw material according to any
one of claims 1 to 4, wherein the reaction step is a step of obtaining a reaction mixture
comprising the thiourethane resin raw material by contacting the composition X and the active
hydrogen compound with each other in the presence of a reaction solvent, and thereby
reacting the thiourethane resin in the composition X, and the active hydrogen compound, with
each other, and
the method further comprises a separation step of separating the thiourethane resin
raw material from the reaction mixture comprising the thiourethane resin raw material.
Claim 6. The method of producing a thiourethane resin raw material according to
claim 5, wherein:
the thiourethane resin raw material comprises a polythiol composition, and
the separation step comprises:
filtering the reaction mixture comprising the thiourethane resin raw material to obtain
a filtrate comprising the polythiol composition;
adding an alkali metal-containing base and then water to the filtrate comprising the
polythiol composition to perform extraction and thereby obtain a water extract comprising an
56
alkali metal salt of the polythiol composition;
adding an acid to the water extract comprising an alkali metal salt of the polythiol
composition to obtain an aqueous liquid comprising the polythiol composition;
adding an extraction solvent to the aqueous liquid comprising the polythiol
composition to perform extraction and thereby obtain an extract comprising the polythiol
composition; and
separating the polythiol composition from the extract comprising the polythiol
composition.
Claim 7. The method of producing a thiourethane resin raw material according to any
one of claims 1 to 6, wherein the composition X is collected in at least one of an eyeglass lens
production process, an eyeglass production process, or an eyeglass disposal process.
Claim 8. The method of producing a thiourethane resin raw material according to any
one of claims 1 to 7, wherein the composition X comprises a milling swarf comprising the
thiourethane resin and the foreign material.
Claim 9. A method of producing a polymerizable composition, the method
comprising:
a step of producing a thiourethane resin raw material by the method of producing a
thiourethane resin raw material according to any one of claims 1 to 8; and
a step of producing a polymerizable composition by using at least a portion of the
thiourethane resin raw material as at least a portion of a raw material.
Claim 10. A method of producing a resin, the method comprising:
a step of producing a polymerizable composition by the method of producing a
polymerizable composition according to claim 9; and
a step of obtaining a resin by curing the polymerizable composition.
Claim 11. A method of producing a resin-containing formed body, the method
comprising:
a step of producing a polymerizable composition by the method of producing a
polymerizable composition according to claim 9; and
a step of obtaining a resin-containing formed body by curing the polymerizable
composition.