JP3279848B2 - High-speed polymerizable resin composition and lens - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition having a high-speed polymerization property and a plastic lens obtained therefrom. Lenses obtained from the present compositions, refractive index (n _d) are those having a high refractive index of 1.59 or more.

[0002]

2. Description of the Related Art Plastic lenses are lighter and harder to break than inorganic glass lenses, and have recently become widespread as eyeglass lenses, camera lenses and optical elements. Currently, as a resin widely used for these purposes, diethylene glycol bisallyl carbonate (hereinafter, CR-39) is used.
) Is radically polymerized. This resin has various characteristics such as excellent impact resistance, light weight, excellent dyeability, and good workability such as cutting and polishing properties. However, the refractive index is 1.50 compared to 1.52 of the inorganic glass.
In order to obtain optical characteristics equivalent to a glass lens, it is necessary to reduce the refractive index of the lens, and the center thickness or the edge thickness of the lens increases, and it is inevitable that the overall thickness increases. . Therefore, a lens resin having a higher refractive index is desired.

For this reason, the present inventors have previously proposed a plastic lens made of a sulfur-containing urethane resin obtained by polymerizing polyisocyanate and polythiol (Japanese Patent Publication No. 4-15249). This resin is a refractive index (n _d) has a 1.57 or more high refractive index, and, CR
It also has various advantages of -39 and is widely used at present. However, this resin has a disadvantage that the polymerization time is long, and if the polymerization is carried out in a short time, optical inhomogeneity (striae) is likely to occur in the lens. Further, the present inventors have proposed a composition in which an acrylate, methacrylate or styrene having a hydroxyl group or a mercapto group is added to the above-mentioned sulfur-containing urethane resin for the purpose of improving the heat distortion temperature (Japanese Patent Application Laid-Open No. Hei 1-1990). 96208). However, when a resin is produced using this composition, the heat distortion temperature is improved, but when polymerized at a high speed, optical inhomogeneity (striae) occurs and a sufficient refractive index is not necessarily obtained. I couldn't. Furthermore, there has been proposed a composition for improving the thermal deformation temperature and the surface hardness of a plastic lens by the same method (Japanese Patent Application Laid-Open No. 5-25240). However, since this composition uses tolylene diisocyanate, it has a relatively high refractive index, but has a disadvantage of yellowing over time due to ultraviolet rays in sunlight.

[0004]

The object of the present invention is to solve the above has a high-speed polymerizable, addition, refractive index (n _d) of as high as 1.59 or more, not over time cause the phenomenon of yellowing Sulfur It is to provide a urethane resin.

[0005]

SUMMARY OF THE INVENTION The present inventors have developed a method for solving the above problem, that is, having a refractive index (n _d ) of 1.59 or more without using tolylene diisocyanate, and The present inventors have conducted intensive studies on resin compositions having high-speed polymerization properties. As a result, by using a polythiol having three or more mercapto groups, it is possible to impart sufficient heat resistance to a resin after polymerization as a plastic lens to withstand heat during polishing and dyeing. By using a polythiol in an amount of 40% by weight or more,
It has been found that the refractive index (n _d ) of the obtained resin can be maintained at 1.59 or more, and further, even when polymerized at a high speed, it is difficult to cause fatal optical inhomogeneity (striation) as a plastic lens. The inventors have found a sulfur-containing urethane resin composition which does not cause a yellowing phenomenon with time, and have completed the present invention.

That is, the present invention provides a) i) a compound represented by the general formula (I)
A mixture of an aromatic polyisocyanate compound represented by the following formula (2) and ii) a polythiol having at least three mercapto groups in one molecule and having a sulfur content of 40% by weight or more; B) a compound comprising at least one hydroxyl or mercapto functional group and at least one acryl, methacrylic or styryl functional group in one molecule; A composition comprising at least 10 parts by weight and less than 30 parts by weight, wherein the ratio of isocyanate group to mercapto group and hydroxyl group in the composition is -NCO group /
(-SH group + -OH group) equivalent ratio of 0.50 to 1.5
The resulting resin has a refractive index ( _nd ) of 1.
The present invention relates to a high-speed polymerizable resin composition of 59 or more. The present invention also relates to a high refractive index plastic lens obtained by subjecting the above composition to heat polymerization.

[0007]

Embedded image (In the formula, R represents a hydrogen atom or a methyl group.) The resin composition of the present invention can be obtained even when the polymerization time is significantly shortened, as compared with a conventional case where heat polymerization is carried out only with a polyisocyanate and a polythiol. It does not cause optically heterogeneous (striated) portions in the lens, does not cause yellowing over time, and improves the surface hardness of the obtained resin.

The polyisocyanate represented by the general formula (I) in the present invention is, specifically, o-xylylene diisocyanate, m-xylylene diisocyanate, p-
Xylylene diisocyanate, 1,3-bis (α, α-
Compounds such as dimethylisocyanatemethyl) benzene and 1,4-bis (α, α-dimethylisocyanatomethyl) benzene. These may be used alone or as a mixture. Compounds having at least three mercapto groups in one molecule and having a sulfur content of 40% by weight or more include 1,2-bis (mercaptoethyl) trithioglycerin, pentaerythrithiol, , 4-
And polythiol compounds such as tris (mercaptomethyl) benzene and 1,3,5-tris (mercaptomethyl) benzene.

The compound having at least one hydroxyl group or mercapto functional group and at least one acrylic, methacrylic or styryl functional group in one molecule includes, for example, Compounds in which an epoxy group or a thiirane group such as hydroxyethyl acrylate or hydroxyethyl methacrylate is opened with acrylic acid or methacrylic acid, 3-phenoxy-
Acrylic acid or methacrylic acid ring-opened product of phenylglycidyl ether such as 2-hydroxypropyl acrylate or methacrylate, acrylic acid or methacrylic acid opened product of 2,4-dibromophenyl glycidyl ether, acrylic acid or methacrylic acid of bisphenol A diglycidyl ether Examples of the ring-opened product include compounds such as 1,3-bis (acryloyl) glycerin, 1,3-bis (methacryloyl) glycerin, 1-acryloyl-2-methacryloylglycerin, hydroxymethylstyrene, and mercaptomethylstyrene. Some of these compounds are commercially available,
Relatively easily available.

The high-speed polymerizable resin composition for a high refractive index lens of the present invention comprises: a) i) an aromatic polyisocyanate compound represented by the general formula (I); and ii) at least three aromatic polyisocyanate compounds per molecule. A mixture of a polythiol having a mercapto group and a sulfur content of 40% by weight or more and 70 parts by weight or more and less than 90 parts by weight; b) at least one functional group of either a hydroxyl group or a mercapto group in one molecule And a compound having at least one functional group of at least one of an acrylic group, a methacryl group, and a styryl group in a proportion of 10 parts by weight or more and less than 30 parts by weight. If component b) is less than 10 parts by weight, the surface hardness tends to be insufficiently improved, and if it exceeds 30 parts by weight, the refractive index tends to decrease. Further, in the composition of the present invention, the ratio of the equivalent of -SH group and -OH group to the equivalent of -NCO group in the composition is NCO group / (SH group + O
H)) in the range of 0.50 to 1.50, preferably 0.7
It is in the range of 5-1.25. Less than 0.50, or 1.
If it exceeds 50, it tends to be difficult to obtain the rigidity of the resin.

In order to obtain a plastic lens using the resin composition of the present invention, the resin composition is polymerized by heating. At that time, tin compounds such as dibutyltin dilaurate and dimethyltin dichloride to promote the urethane polymerization reaction of polyisocyanate and polythiol,
A polymerization catalyst such as morpholine and dimethylaminobenzene is added in an amount of 0.001 to 1.0% by weight based on the total amount of the composition. Peroxides such as benzoyl oxide, dicumyl peroxide and di-t-butyl peroxide are used in an amount of 0.01 to 3.
0% by weight may be added.

In addition, when the high-speed polymerizable resin composition of the present invention is polymerized by casting polymerization or the like, a wax, silicon or fluorine-based external mold release agent is previously provided on the surface of the mold so as to be easily released from the mold. Or a silicone-based or fluorine-based nonionic surfactant, or an anionic surfactant such as an acidic phosphate ester, etc., as an internally added mold release agent to the composition of the present invention. It is desirable to keep. When an internal addition type release agent is used, its addition amount is 10 to 20,000 with respect to the composition.
ppm is desirable. Furthermore, in the composition of the present invention, in order to improve the weather resistance of the resin obtained by polymerization, additives such as an ultraviolet absorber, an antioxidant, an anti-coloring agent, and a fluorescent dye are appropriately added as necessary. May be added. Further, in order to improve the dyeability of the resin obtained by polymerization in a disperse dye bath, pentaerythritol tetrakis (thioglycolate), pentaerythritol, and the like are provided as long as the effects of the present invention are not impaired. At least one of tetrakis (β-mercaptopropionate), trimethylolpropane tris (thioglycolate) and trimethylolpropane tris (β-mercaptopropionate) may be added. In this case, in order to maintain a high refractive index, the amount added is preferably less than 20 parts by weight in the composition.

With respect to the high-speed polymerizable resin composition of the present invention,
In the case where a resin is obtained by heat polymerization in a special mold such as an eyeglass lens, a camera lens, and an optical element, the following example is given. That is, the composition of the present invention, or a composition that has been preliminarily polymerized, if necessary,
After adding a polymerization catalyst, an internal addition type release agent, an ultraviolet absorber and the like to make a uniform solution, the solution is made of glass or metal having a spacer made of ethylene-vinyl acetate copolymer or polyvinyl chloride. After pouring into a mold, put in a heating polymerization furnace, heat polymerization, then cool,
A desired type of molded product can be obtained. The time required for casting polymerization varies depending on the size of the molded product, but when producing spectacle lenses of the same strength, there is no optical inhomogeneity (stria) by polymerizing ordinary sulfur-containing urethane lenses. It is 1/5 to 1/2 of the time required for obtaining a lens.
The lens obtained by curing the composition of the present invention has a higher surface hardness than the resin of the composition of the present invention polymerized using only polyisocyanate and polythiol.

[0014]

The present invention will be described in detail with reference to the following examples, but the present invention is not limited thereto. In addition, the part in an Example shows a weight part. Also,
Among the performance tests of the obtained lens, the refractive index, Abbe number,
Specific gravity, workability, optical distortion and pencil hardness were measured by the following test methods.・ Refractive index, Abbe number: 20 ° C. using Pulrich refractometer
Was measured. -Specific gravity: measured by Archimedes' method. Processability: The surface was ground with a ball mill for processing eyeglass lenses, and the one with a good ground surface was evaluated as good (O). -Optical distortion: Using an optical strain meter, those having no visual distortion were rated as (○), and those with distortion were rated (x). -Pencil hardness: It was performed according to JIS K-5400 method. -Weather resistance: The lens resin was set in a weatherometer equipped with a sunshine carbon arc lamp, and after 48 hours, the lens was taken out and the hues of the lens resin before and after the test were compared. The evaluation method was no change (o) and yellowing (x).

Example 1 188 parts by weight of m-xylylene diisocyanate (1.0 part by weight)
Mol), 130 parts by weight (0.5 mol) of 1,2-bis (mercaptoethyl) trithioglycerin, and 1,3-
114 parts by weight of bis (methacryloyl) glycerin (0.
5 mol) while cooling to 10 ° C., and then 50 ppm of dibutyltin dichloride was added to the entire mixture.
1000 ppm of di-t-butyl peroxide and 3000 ppm of dioctyl acid phosphate are added, mixed and homogenized, and then injected into a mold for producing a -4 diopter spectacle lens made of a glass mold and a gasket. did. Then, from 45 ° C to 130 ° C, 3
After heating and polymerizing at elevated temperature over a period of time, the mixture was heated at 130 ° C. for 1 hour, cooled, and released to obtain a lens. The lens is
The refractive index was 1.595, the Abbe number was 38, and the specific gravity was 1.33. The grindability was good, there was no optical distortion, and the pencil hardness was 3H. Examples 2 to 5 In the same manner as in Example 1, a lens was formed with the composition shown in Table 1 (Table 1). Table 2 (Table 2) shows the evaluation results of the obtained lenses.

[0016]

[Table 1] 1,3-DMIMB: 1,3-bis (α, α-dimethylisocyanatomethyl) benzene PEMP: pentaerythritol tetrakis (β-mercaptopropionate) ol or thiol: hydroxyl group or mercapto group;
Compound having acrylic group, methacryl group or styryl group

Comparative Example 1 In the same manner as in Example 1, 188 parts by weight (1.0 mol) of m-xylylene diisocyanate and 172 parts by weight of 1,2-bis (mercaptoethyl) trithioglycerin (0.66 parts) were used.
Mol) while cooling to 10 ° C., then adding 50 ppm of dibutyltin dichloride and 3000 pm of dioctyl acid phosphate to the whole mixture,
After further mixing and homogenizing, the mixture was poured into a mold for producing spectacle lenses for -4 diopters, which was composed of a glass mold and a gasket. Subsequent operations were performed in the same manner as in Example 1 to obtain a lens. Table 2 shows the physical properties of this lens.

Comparative Example 2 In the same manner as in Example 1, 188 parts by weight (1.0 mol) of m-xylylene diisocyanate and 244 parts (0.5 mol) of pentaerythritol tetrakis (mercaptopropionate) were added to 10 parts by weight. After mixing while cooling to ℃
50 parts of dibutyltin dichloride were added to the whole mixture.
ppm and dioctyl acid phosphate ester 3000p
Then, the mixture was further mixed and made uniform, and then poured into a mold for producing a spectacle lens for -4 diopters, which was made up of a glass mold and a gasket. The subsequent operations are described in Example 1.
A lens was obtained in the same manner as described above. Table 2 shows the physical properties of this lens.

Comparative Example 3 In Example 1, m-xylylene diisocyanate 1
Except that 88 parts by weight (1.0 mol) and 195 parts by weight (0.4 mol) of pentaerythritol tetrakis (3-mercaptopropionate) and 52 parts by weight (0.4 mol) of hydroxyethyl methacrylate were used. Example 1
A lens was obtained in the same manner as described above. Table 2 shows the physical properties of the lens. Comparative Example 4 In Example 1, m-xylylene diisocyanate 1
88 parts by weight (1.0 mol), 136 parts by weight (0.80 mol) of 1,3-xylylenedithiol and the methacrylic acid ring-opened product of bisphenol A diglycidyl ether 10
A lens was obtained in the same manner as in Example 1 except that 2 parts by weight (0.20 mol) was used. Table 2 shows the physical properties of the lens.

[0020]

[Table 2]

Comparative Examples 5 to 9 In Comparative Example 1, the temperature was changed from 45.degree. C. to 130.degree.
A lens was produced in the same manner as in Comparative Example 1, except that the heating time until heating was changed. Table 3 (Table 3) shows the results of observing the state of the optical distortion of the obtained lens.

[0022]

[Table 3]

Example 7 A lens was obtained in the same manner as in Example 1 except that 500 ppm of Tinuvin PS, an ultraviolet absorber manufactured by Ciba Geigy, was added to the composition of Example 1. When the change in hue before and after the weather resistance test of this lens was compared, no change (変 化) was found. There was no optical distortion.

Comparative Example 10 Instead of 188 parts by weight (1.0 mol) of m-xylylene diisocyanate of Example 1, 94 parts by weight (0.5 mol) of m-xylylene diisocyanate and 2,4-tolylene diisocyanate were used. After using a mixture of 87 parts by weight (0.5 mol) and adding 500 ppm of Ciba Geigy's UV absorber Tinuvin PS, the mixture was treated in the same manner as in Example 1. An exothermic reaction occurred and the mixture thickened vigorously. However, it was difficult to manufacture lenses. Therefore, a new liquid temperature of -5
A lens was obtained in the same manner as in Example 1 except that mixing was performed while cooling to a temperature of not more than ° C. When the hue change of this lens before and after the weather resistance test was compared, the lens was markedly colored yellow (x). Also, the optical distortion of the lens was conspicuous.

[0025]

The sulfur-containing urethane resin obtained from the composition of the present invention is less likely to cause optical nonuniformity (striae) even when polymerized in a shorter time than conventional resins. Because of its high pencil hardness, it is useful as a resin for eyeglass lenses, camera lenses and optical elements.

(56) References JP-A-5-25240 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 18/00-18/87

Claims (5)

(57) [Claims] 1. a) i) an aromatic polyisocyanate compound represented by the general formula (I) (formula 1): (Wherein, R represents a hydrogen atom or a methyl group) ii) having at least three mercapto groups in one molecule;
A mixture of at least 70 parts by weight and less than 90 parts by weight of a mixture with a polythiol having a sulfur content of 40% by weight or more; b) at least one functional group of either a hydroxyl group or a mercapto group in one molecule; And at least 10 parts by weight and less than 30 parts by weight of a compound having an acrylic group, a methacrylic group or a styryl group, wherein the isocyanate group, the mercapto group and the hydroxyl group in the composition. Is -NCO group /
(-SH group + -OH group) equivalent ratio of 0.50 to 1.5
The resulting resin has a refractive index ( _nd ) of 1.
A high-speed polymerizable resin composition having a molecular weight of 59 or more. 2. The aromatic polyisocyanate compound represented by the general formula (I) comprises o-xylylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, 1,3-bis (α, α-dimethyl Isocyanatomethyl) benzene, 1,4-bis (α, α
The high-speed polymerizable resin composition according to claim 1, which is at least one member selected from the group consisting of -dimethylisocyanatomethyl) benzene. 3. A polythiol having at least three mercapto groups in one molecule and having a sulfur content of 40% by weight or more is 1,2-bis (mercaptoethyl) trithioglycerin, pentaerythrithiol, 3. The high-speed polymerizable resin composition according to claim 1, which is at least one selected from the group consisting of 1,2,4-tris (mercaptomethyl) benzene and 1,3,5-tris (mercaptomethyl) benzene. 4. Pentaerythritol tetrakis (thioglycolate), pentaerythritol tetrakis (β
-Mercaptopropionate), trimethylolpropane tris (thioglycolate) or trimethylolpropane tris (β-mercaptopropionate), containing less than 20 parts by weight.
3. The high-speed polymerizable resin composition according to any one of 3. 5. A high refractive index plastic lens obtained by subjecting the composition according to claim 1 to heat polymerization.