Process for producing polyurethane resin

Patent metadata

Field	Value
Publication number	US-9464154-B2
Application number	US-201314646109-A
Country	US
Kind code	B2
Filing date	Nov 1, 2013
Priority date	Nov 21, 2012
Publication date	Oct 11, 2016
Grant date	Oct 11, 2016

Abstract

A process for producing a polyurethane resin of the present invention includes a step (i) of obtaining a prepolymer by adding an alcohol (B) to isocyanate (A) such that a ratio of hydroxyl groups to isocyanato groups of the isocyanate (A) falls into a range of 10 mol % to 20 mol % and reacting the isocyanate (A) with the alcohol (B) in the presence of an acidic phosphoric acid ester (C) and a hindered amine-based compound (D), a step (ii) of obtaining a polymerizable composition in a manner in which the alcohol (B) is further added to and mixed with the prepolymer at a temperature of equal to or less than 30° C., and a step (iii) of polymerizing the prepolymer and the alcohol (B) contained in the polymerizable composition. The isocyanate (A) contains an aromatic isocyanate and the alcohol (B) has two or more hydroxyl groups and is further defined.

First claim

The invention claimed is:

1. A process for producing a polyurethane resin, comprising:
a step (i) of obtaining a prepolymer by adding an alcohol (B) to isocyanate (A) such that a ratio of hydroxyl groups to isocyanato groups of the isocyanate (A) falls into a range of 10 mol % to 20 mol % and reacting the isocyanate (A) with the alcohol (B) in the presence of an acidic phosphoric acid ester (C) and a hindered amine-based compound (D);
a step (ii) of obtaining a polymerizable composition in a manner in which the alcohol (B) is further added to and mixed with the prepolymer at a temperature of equal to or less than 30° C.; and
a step (iii) of polymerizing the prepolymer and the alcohol (B) contained in the polymerizable composition,
wherein the isocyanate (A) is one or more kinds of isocyanate (A) having two or more isocyanato groups, which contains aromatic isocyanate,
the alcohol (B) includes one or more kinds of alcohol having two or more hydroxyl groups, and
in the alcohol (B), a ratio of secondary hydroxyl groups to a total molar number of primary and secondary hydroxyl groups is equal to or greater than 50 mol %.

2. The process according to claim 1 ,
wherein a reaction temperature of the step (i) is equal to or less than 30° C.

3. The process according to claim 1 ,
wherein in the step (iii), a heating start temperature at the time of polymerizing the prepolymer and the alcohol (B) is equal to or less than 30° C.

4. The process according to claim 1 ,
wherein the viscosity of the prepolymer and the polymerizable composition is equal to or less than 1,000 mPa·s at 20° C.

5. The process according to claim 1 ,
wherein the step (ii) is performed by using a mixing apparatus comprising:
a cylindrical container,
a shaft that is inserted into the container from the upper portion of the container along the central axis direction of the container,
a stirring blade that is wound in the form of a screw around the outer circumferential surface of the shaft,
a first supply, portion that is disposed in the upper portion of the container and supplies the prepolymer into the container,
a second supply portion that is disposed in the upper portion of the container and supplies the alcohol (B) into the container, and
an ejection portion that is disposed at the bottom of the container,
wherein the step (ii) includes a step of supplying the prepolymer and the alcohol (B) into the container from the first supply portion and the second supply portion respectively and
a step of preparing the polymerizable composition by rotating the shaft such that the prepolymer and the alcohol (B) are moved down while being mixed together at a temperature of equal to or less than 30° C. by the stirring blade, which is wound in the form of a screw around the outer circumferential surface of the shaft, and ejecting the obtained polymerizable composition from the ejection portion.

6. The process according to claim 5 ,
wherein a rotation frequency of the shaft is within a range of 1,000 rpm to 4,000 rpm, and a rate at which the polymerizable composition is ejected from the ejection portion is within a range of 0.5 g/s to 4.0 g/s.

7. The process according to claim 5 ,
wherein the viscosity of the polymerizable composition obtained in the step (ii) is equal to or less than 500 mPa·s at 20° C.

8. The process according to claim 1 ,
wherein the aromatic isocyanate contained in the isocyanate (A) is 2,4-tolylene diisocyanate or a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate.

9. The process according to claim 1 ,
wherein the alcohol (B) contains one or more kinds of compound selected from among glycerol, diglycerol, trimethylolpropane, pentaerythritol, di(trimethylolpropane), an ethylene oxide adduct of glycerol, an ethylene oxide adduct of trimethylolpropane, an ethylene oxide adduct of pentaerythritol, a propylene oxide adduct of glycerol, a propylene oxide adduct of trimethylolpropane, and a propylene oxide adduct of pentaerythritol.

10. The process according to claim 1 ,
wherein the alcohol (B) contains one or more kinds of compound selected from among a propylene oxide adduct of glycerol, a propylene oxide adduct of trimethylolpropane, and a propylene oxide adduct of pentaerythritol.

11. The process according to claim 1 ,
wherein the acidic phosphoric acid ester (C) is contained in the polymerizable composition, in an amount of 0.1 parts by weight to 3.0 parts by weight with respect to a total of 100 parts by weight of the isocyanate (A) and the alcohol (B).

12. The process according to claim 1 ,
wherein the acidic phosphoric acid ester (C) is an acidic phosphoric acid ester represented by Formula (1),

wherein, in the formula, m represents an integer of 1 or 2; n represents an integer of 0 to 18; R 1 represents an alkyl group having 1 to 20 carbon atoms; and each of R 2 and R 3 independently represents a hydrogen atom, a methyl group, or an ethyl group.

13. The process according to claim 1 ,
wherein the hindered amine-based compound (D) is contained in the polymerizable composition, in an amount of 0.1 parts by weight to 2.0 parts by weight with respect to a total of 100 parts by weight of the isocyanate (A) and the alcohol (B).

14. A polyurethane resin obtained by the process according to claim 1 .

15. A manufacturing method of a polyurethane-molded product,
wherein in the process for producing a polyurethane resin according to claim 1 , the step (iii) includes a step of injecting the polymerizable composition into a mold,
and a step of polymerizing the prepolymer and the alcohol (B) contained in the polymerizable composition in the mold.

16. A polyurethane-molded product obtained by the manufacturing method according to claim 15 .

17. An optical material comprised of the polyurethane-molded product according to claim 16 .

18. A plastic lens comprised of the optical material according to claim 17 .

19. A manufacturing method of a plastic polarizing lens,
wherein in the process for producing a polyurethane resin according to claim 1 , a step of fixing a polarizing film into a casting mold for lens casting in a state in which at least one surface of the polarizing film is separated from the mold is performed before the step (iii), and the step (iii) includes a step of injecting the polymerizable composition obtained in the step (ii) into space(s) between the polarizing film and the mold, and a step of polymerizing and curing the polymerizable composition and laminating a layer comprised of the polyurethane resin over at least one surface of the polarizing film.

20. A plastic polarizing lens obtained by the manufacturing method according to claim 19 .

Assignees

• Mitsui Chemicals Inc

Inventors

• Kawato Nobuo
• Ogawa Tatsuya
• Hashimoto Toshiya
• Tanaka Mamoru
• Kuma Shigetoshi

Classifications

• B29C45/0001

  characterised by the choice of material · CPC title

• C08G18/8029

  Masked aromatic polyisocyanates · CPC title

• C08K5/521

  Esters of phosphoric acids, e.g. of H3PO4 · CPC title

• C08G18/10 Primary

  Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step · CPC title

• B29C45/14008

  Inserting articles into the mould (B29C45/14827 takes precedence) · CPC title