KR20040065454A - Resin composition for producing optical lens having low density and medium refraction index, and optical lens produced with the same - Google Patents

Abstract

PURPOSE: Provided are a resin composition for optical lens with low specific gravity and medium retraction index, which has excellent heat resistance, low absorption, impact resistance, transparency, moldability, dyeing behavior, and especially optical stability, and an optical lens produced with the same. CONSTITUTION: The resin composition comprises (A) 10-50 wt% of epoxy diacrylate compound having at least two functionalities, which has a bisphenol A backbone and is represented by formula 1, (B) 0-40 wt% of bisphenol A epoxy diacrylate having at least two functionalities, which is represented by formula 2, (C) 0-20 wt% of aliphatic compound having at least 3 acryl radicals, (D) 10-30 wt% of aliphatic acrylic acid compound, (E) 0-25 wt% of aromatic allyl compound comprising at least one functionality, (F) 5-30 wt% of aliphatic compound having at least two hydroxyl groups and at least two acryl groups, and (G) 5-20 wt% of aliphatic methacrylate compound having at least two acryl groups.

Description

Resin composition for producing optical lens having low density and medium refraction index, and optical lens produced with the same}

The present invention relates to a resin composition for a low specific gravity, medium refractive index optical lens, more specifically, having a refractive index of 1.55 or more, a specific gravity of 1.20 or less and a high Abbe number of 40 or more, and impact resistance, transparency, moldability, dyeability, in particular light It is related with the resin composition which can manufacture the low specific gravity, medium refractive index optical lens which is excellent in stability, and the optical lens manufactured using the same.

Compared with inorganic glass lenses, plastic lenses are lightweight, do not break easily, and are easy to dye, and thus are rapidly being widely used as optical elements such as spectacle lenses and camera lenses. A representative of such plastic lenses is a radical polymerization product of diethylene glycol bis (allylcarbonate) sold under the trade name CR-39 (PPG Industries, Inc., USA). The lens made of the resin is lightweight, has excellent impact resistance and dyeability, as well as excellent cutting, polishing, workability and the like. However, since the plastic lens has a refractive index (n ^D ) of about 1.50 and a lower refractive index than that of the inorganic glass lens (n ^D = 1.52), in order to increase the refractive index of the plastic lens and obtain optical characteristics equivalent to those of the inorganic glass lens, Since the thickness of the center or surroundings must be increased, there is a disadvantage that the thickness of the lens as a whole becomes thick.

Therefore, recently, in order to achieve high refractive index and high productivity of plastic lenses, plastic lenses made of various monomers and oligomers instead of CR-39 have been proposed. In general, plastic lenses should be excellent in heat resistance, impact resistance, low water absorption, surface precision of molded products, and dyeing properties. Among the properties of such plastic lenses, monomers and oligomers that give elasticity-rich structures such as ether bonds, urethane bonds, ester bonds, and carbonate bonds have been proposed as components for improving impact resistance and dyeing properties. For example, Japanese Patent Application Laid-Open No. 64-16813 discloses a low viscosity di (meth) acrylate monomer which has an ether bond in a molecule and can improve mold workability. As representative examples of the (meth) acrylate monomers, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and the like are disclosed. When the number of repeating units of ethylene oxide or propylene oxide increases in such a monomer, impact resistance and dyeing resistance of the lens are improved. However, if the number of repeating units of ethylene oxide or propylene oxide is increased, there is a disadvantage in that the heat resistance, low water absorption, and surface precision of the lens are lowered. In order to compensate for this disadvantage, a method of improving the heat resistance and low absorption of plastic lenses by introducing a hydrocarbon chain, an aromatic ring, a halogen atom, or the like into a molecule has been proposed (see Japanese Patent Application Laid-Open No. 57-66401). However, the introduction of a hydrocarbon chain, an aromatic ring, a halogen atom, etc. in the molecule in this way, the disadvantage that the impact resistance and stainability of the lens is lowered. Therefore, the research on the resin composition which can satisfy the various characteristics which the plastic lens needs evenly is currently actively progressing.

It is therefore an object of the present invention to provide a resin composition for producing a low specific gravity, medium refractive index optical lens having a refractive index of at least 1.55, a specific gravity of at most 1.20 and / or a high Abbe number of at least 40.

Another object of the present invention is to provide a resin composition for producing a low specific gravity, medium refractive index optical lens capable of high-speed polymerization by radicals.

It is still another object of the present invention to provide a resin composition for producing a low specific gravity, medium refractive index optical lens having good heat resistance, low water absorption, impact resistance, transparency, moldability, dyeing properties, and especially light stability, and an optical lens prepared therefrom. .

In order to achieve the above object, the present invention is (A) 10 to 50% by weight of a bifunctional or more epoxy diacrylate compound having a bisphenol A skeleton represented by the following formula (1);

[Formula 1]

(Wherein R 1 is a methyl group and n is an integer from 1 to 4).

(B) 0 to 40% by weight of a bifunctional or higher bisphenol A epoxy diacrylate compound represented by the following Chemical Formula 2;

[Formula 2]

(Wherein R 1 is a methyl group, R 2 is hydrogen or a methyl group and n is an integer from 2 to 5).

(C) 0 to 20% by weight of an aliphatic compound having three or more acrylic functional groups; (D) 10 to 30% by weight aliphatic acrylic acid compound; (E) 0 to 25% by weight of an aromatic allyl compound containing at least one functional group; (F) 5 to 30% by weight of an aliphatic compound having two or more hydroxyl groups and two or more acrylic groups; And (G) 5 to 20 wt% of an aliphatic methacrylate compound having two or more acrylic groups.

Here, the (C) aliphatic compound having three or more acrylic functional groups is trimethylolpropane trimethacrylate, the (D) aliphatic acrylic acid compound is methacrylic acid, and (F) two or more hydroxyl groups and two or more acrylics The aliphatic compound having a group is hexanediol diacrylate, and the (G) aliphatic methacrylate compound having two or more acrylic groups is preferably triethylene glycol dimethacrylate, and the (E) aromatic allyl compound is styrene, Alphamethylstyrene, alphamethylstyrenedimer, o-divinylbenzene, m-divinylbenzene, p-divinylbenzene, m-diisopropenylbenzene and the like.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a resin composition for a medium refractive index plastic lens having a bisphenol-A epoxy diacrylate derivative having excellent heat resistance as a basic skeleton, and the present inventors have a bisphenol-based epoxy resin capable of high-speed polymerization by radicals. In order to supplement the impact resistance and formability, extensive research has been conducted on the material which is well crosslinked with the basic resin, and has excellent impact resistance in terms of resin properties, has a medium refractive index and a high Abbe number, and is light in weight. To develop a resin for a plastic lens having a three-dimensional cross-linking, it was confirmed that the visible light transmittance, polishing processability, impact resistance and the like of the plastic lens made of such a resin was completed the present invention. The present invention has a bisphenol A type epoxy acrylate obtained by reacting an equivalent to equivalent weight of epichlorohydrin and acrylic acid as a monomer to impart a balance of impact resistance and low water absorption, and having at least one functional group. It is based on the discovery that polymerizing an aliphatic acrylic acid compound and an aliphatic (methacrylate) compound having two or more hydroxyl groups can produce a plastic lens that is particularly excellent in impact resistance, dyeing resistance, heat resistance and low water absorption. The present invention is also based on the finding that thiol compounds are useful as components for improving epoxy polymethacrylate, impact resistance, transparency, and inter resin crosslinking as components for imparting heat resistance.

The resin composition for optical lenses which concerns on this invention contains the bifunctional or more epoxydiacrylate compound which has the bisphenol A frame | skeleton represented by (A) following General formula (1) as a main component.

Wherein R 1 is a methyl group and n is an integer from 1 to 4.

The bisphenol A-based epoxy diacrylate component has two or more functional groups obtained by, for example, reacting n bisphenol A with n epichlorohydrin and then reacting one epichlorohydrin with two acrylic acids. As the compound, specifically, 4,4- (1-methylethylidene) bisphenol polymer combined with chloromethyl oxirane and 2-propenoate (4,4- (1-methylethylidene) Bisphenol Polymer with (chloromethyloxirane, 2 -propenoate)), and the component (A) functions to give high refractive index, low water absorption, excellent heat resistance and surface precision. The bisphenol A-based epoxy diacrylate component is used in an amount of 10 to 50% by weight based on the total resin composition, and when the content of the component is less than 10% by weight, physical properties such as refractive index, low absorption, heat resistance, and surface precision There is a problem that the improvement effect is insufficient, and if it exceeds 50% by weight, the Abbe number is greatly reduced due to excessive increase in refractive index.

Resin composition according to the present invention (B) represented by the following formula (2), bifunctional or more bisphenol A-based epoxy di (meth) acrylate compound containing a bisphenol-A skeleton and at least 4 moles of ethylene oxide (ethylene oxide) It is preferable to include.

Wherein R 1 is a methyl group, R 2 is hydrogen or a methyl group and n is an integer from 2 to 5. The component represented by the formula (2) is characterized in that ethylene oxide is added compared to the component represented by the formula (1), and serves to impart heat resistance and impact resistance to the lens. The component represented by Chemical Formula 2 is prepared by reacting bisphenol-A with epichlorohydrin and then reacting at least 4 moles of ethylene oxide and 2 moles of (meth) acrylate, or n: 1 equivalent of epoxy and acrylic acid. After the reaction, epichlorohydrin and bisphenol A may be added, specifically, epichlorohydrin and tetraethyleneoxide added Dimethacylate of Bisphenol A, Epichlorohydrin and diethyleneoxide added Diacylate of Bisphenol A, epichlorohydrin and decaethyleneoxide added Dimethacylate of Bisphenol A) and the like. The content of the component (B) is 0 to 40% by weight, preferably 1 to 30% by weight based on the total resin composition, wherein the content of the component exceeds 40% by weight of the refractive index as described above There is a problem with the decrease in Abbe number due to excessive rise.

It is preferable that the resin composition for optical lenses which concerns on this invention contains the aliphatic compound which has (C) 3 or more acrylic functional groups. Such a component (C) easily crosslinks with other components of the resin composition, and functions not only as a crosslinking agent for improving heat resistance, Abbe's number and impact resistance of the polymerized lens, but also as a diluent because of its low viscosity. . Specific examples of the component (C) include trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, triethylolpropane trimethacrylate, and triethylolpropane trimethacrylate. Acrylate (TriethylolPropane Triacrylate), and the like, and the content thereof is 0 to 20% by weight, preferably 1 to 15% by weight, based on the total resin composition, wherein the content of the component exceeds 20% by weight Difficulty in demolding due to the strong adhesion to the glass mold due to the increase in hydroxyl group, thereby reducing the workability and the problem of mold breakage.

The resin composition of this invention contains 10-30 weight% of (D) aliphatic acrylic acid compounds with respect to the whole resin composition. The aliphatic acrylic acid compound plays an important role in improving the mechanical strength of the polymerized lens, and specifically, methacrylic acid may be exemplified. When the content of the aliphatic acrylic acid compound is less than 10% by weight, the mechanical strength of the polymerized lens may be lowered. If the content of the aliphatic acrylic acid is more than 30% by weight, the refractive index may be reduced and the mold may be damaged due to strong adhesion to the mold.

Component (E) used in the present invention is an aromatic allyl compound containing at least one functional group. The aromatic allyl compound containing one or more functional groups improves the refractive index of the optical lens and functions to dilute other components, and those capable of radical copolymerization with other components are used. Specific examples of the aromatic allyl compound include styrene monomer, alpha methyl styrene, alpha methyl styrene dimer, o-divinyl benzene, m-divinyl benzene, p-divinyl benzene, m-diisopro Phenylbenzene etc. can be illustrated, Especially preferably, styrene, alphamethylstyrene, o-divinylbenzene, m-divinylbenzene, p-divinylbenzene can be used. The content of the aromatic allyl compound is 0 to 25% by weight, preferably 1 to 15% by weight, based on the total resin composition. If the content of the aromatic allyl compound is more than 25% by weight, The lens is too hard during reduction and lens shaping and can cause problems of lens breakage due to impact.

Component (F) used in the present invention is an aliphatic compound having two or more hydroxyl groups and two or more acryl groups, and the component (F) acts as a warp to prevent the mechanical strength of the lens from becoming too hard. This improves the impact resistance and elasticity of the molded lens. Specific examples of the component (F) may include Hexanediol Diacrylate, the content of which is 5 to 30% by weight, preferably 10 to 25% by weight based on the total resin composition. If the content of the component (F) is less than 5% by weight, the impact resistance and elasticity of the lens are not improved. If the content of the component (F) exceeds 30% by weight, it is difficult to demould and mold breakage due to the strong adhesion to the glass mold due to hydroxyl groups. May cause problems.

The resin composition for optical lenses which concerns on this invention contains the aliphatic methacrylate which has (G) 2 or more acrylic groups. The aliphatic methacrylate component having two or more acrylic groups has an excellent effect on crosslinking, and increases the mechanical strength and Abbe number of the lens, thereby suppressing light scattering. Specifically, triethylene glycol di A methacrylate (Triethyleneglycol Dimethacrylate) can be illustrated. The content of the component (G) is 5 to 20% by weight based on the total resin composition. If the content of the component (G) is less than 5% by weight, the mechanical strength and the Abbe number of the lens may be lowered, and the weight is 20%. If the content exceeds 20%, the color of the raw material is yellow, which causes a problem that the color changes to yellow when the lens is molded, and a problem that the refractive index may also decrease.

If necessary, radical copolymerization may also be performed by post-adding a thiol compound of 0 to 10% by weight to the resin composition for an optical lens according to the present invention. The thiol compound included in the post-treatment improves the heat resistance of the resin and, since it contains sulfur atoms in the molecule, serves to increase the refractive index of the lens. It is preferable to use a bifunctional or higher thiol compound. Specific examples of such thiol compounds include dimercaptodiethyl sulfide, ethanedithiol, trimethylolpropane trimercaptopropionate, bis (mercaptomethyl) sulfide, bis (mercaptopropyl) sulfide, and 2-mercapto Polythiol compounds, such as ethyl ether bis (3-mercapto propionate), can be illustrated. Moreover, the composition for plastic lenses of this invention may also contain various additives, such as antioxidant, a yellowing agent, a ultraviolet absorber, dye, as needed in the range which does not impair the effect of this invention.

The plastic lens composition of the present invention is used to prepare an optical lens by mixing and stirring the components (A) to (G) by a conventional method in the presence of a polymerization initiator, adding a thiol compound as a post-fix, followed by radical copolymerization. In this case, various additives may be blended as necessary. As a polymerization initiator used for hardening of the composition for optical lenses which concerns on this invention, Organic peroxides, such as benzoyl peroxide, t-butylperoxy isobutylate, t-butylperoxy-2-ethylhexanoate; Azo compounds, such as 2,2'- azobisisobutyronitrile and 2,2'- azobis (2, 4- dimethyl valeronitrile); Photoinitiators, such as 2-hydroxy-2-methyl-1-phenylpropan-1-one, methylphenylglyoxylate, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, can be illustrated. The compounding ratio of such a polymerization initiator is 0.01-5 weight part normally with respect to 100 weight part of (A)-(G) component. In the polymerization curing method, the composition of the present invention including the polymerization initiator is injected into a mirror polished two glass plate molds through a gasket made of ethylene-vinyl acetate copolymer, and the mixture is heated at a temperature of 35 to 100 ° C. for about 20 hours. The polymerization can be carried out by heating from one or both sides of the mold. As the mold, glass and glass, glass and plastic plates, glass and metal plates, or a combination thereof may be used. As the gasket, a polyester adhesive tape may be used in addition to the thermoplastic resin. When the curing of the polymer is complete, annealing is performed at a temperature of 100 ° C. or higher according to a conventional method. In addition, if necessary, the surface of the optical lens may be polished, or may be further subjected to physical and chemical treatments such as antistatic treatment, hard coat treatment, anti-reflective coating treatment, and dyeing treatment.

The optical lens obtained by curing the resin composition for an optical lens according to the present invention is polymerized in a short time, so that the productivity is high, the refractive index (n ^D ₂₀ ) is 1.55 or more, usually 1.595 or less, specific gravity is 1.20 or less, Abbe number Is 40 or more, and has excellent physical properties such as transparency, optical uniformity and impact resistance. In addition, the optical lens obtained by curing the resin composition according to the present invention is mainly composed of a polyvinyl bond by a reactive unsaturated group, excellent productivity, low viscosity, and low water absorption and conventional urethane which is an advantage of conventional aryl and acrylic resins The resin has the advantages of high refractive index, high Abbe's number, heat resistance, surface precision, excellent surface hardness and impact resistance, as well as low specific gravity to reduce the weight of the lens. In addition, unlike the existing CR-39, which requires a long time for synthesis and production, the compounding and processing process can be shortened to prevent productivity loss and reduce production costs.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the following examples the units of each component content are in weight percent.

[Example 1-4, Comparative Example 1-2]

After uniformly mixing and stirring the compounds of the contents and ingredients shown in Table 1 below, dimercaptodiethylsulfide, a thiol compound, was added as a post addition as necessary, followed by 2,2'-azobis (2,4 0.3 parts by weight of dimethylvaleronitrile) and stirred again. The mixture was poured into two glass molds, heat cured for 20 hours at a temperature of 35 to 100 ° C. according to a conventional method, and then cooled to 65 ° C. when curing was completed, and then the cured molding was taken out of the mold, and then at 110 ° C. Annealing for 1 hour to remove residual stress to prepare a plastic lens. Evaluation of physical properties of the prepared optical plastic lens is shown in Table 1 below.

Raw material name Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 BPA-Polymer 20 45 42 47 56 BP-2-EMA 54 BPA-4E-EDMA or BP-2EA 27 TMPTMA 5 15 10 5 9 MMA 15 15 MAA 15 20 10 15 SM 10 15 10 5 5 HDDA 15 10 18 15 18 TEGDMA 8 10 5 13 9 HEMA 6 a -MSD One DVB 1.5 DMDS (Referral) One One One 0.5 Refractive Index ( n ^D ₂₀ ) 1.5510 1.5490 1.5538 1.5513 1.549 1.548 Abbe Number ( v ^D ₂₀ ) 40 42 40 40 41 40 Specific gravity (g / cm ³ ) 1.15 1.15 1.16 1.16 1.17 1.18 Impact resistance O O O O O O Weather resistance O O O O Ⅹ Ⅹ Dyeability O O O O Ⅹ O Heat resistance O O O O Ⅹ O Optical distortion O O O O O Ⅹ Light transmittance 93% 93% 92% 93% 89% 85% UV cut 100% 100% 100% 100% 95% 90% Solvent resistance O O O O Ⅹ Ⅹ

In Table 1, BPA-Polymer represents a 4,4- (1-methylethylidene) bisphenol polymer to which chloromethyloxirane and 2-propenoate are bonded, and BP-2-EMA is a diethylene oxide added. Bisphenol A dimethacrylate (Diethyleneoxide added Dimethacylate of Bisphenol A), BPA-4E-EDMA represents epichlorohydrin and tetraethylene oxide added bisphenol A dimethacrylate, BP-2EA is epichloro Bisphenol A diacrylate to which hydrin and diethylene oxide are added, TMPTMA represents trimethylolpropane trimethacrylate, MMA represents methyl methacrylate, MAA represents methacrylic acid, SM Represents styrene monomer, HDDA represents hexanediol diacrylate, TEGDMA represents triethylene glycol dimethacrylate, and HEMA is hydroxy Hydroxyethyl Methacrylate, DMDS stands for dimercaptodiethylsulfide, m-DVB-57 stands for m-divinylbenzene (57%), and a-MSD stands for a-methylstyrene demonomer ( a-MethylStyrene Dimonomer).

In addition, the evaluation method of each physical property shown in Table 1 is as follows.

(1) Refractive index, Abbe's number: It measured at 20 degreeC using the Folfrihi refractometer.

(2) Light transmittance and UV blocking rate: It measured using the spectrophotometer.

(3) Specific gravity: The ratio of the weight and volume of the plastic lens was determined by an underwater substitution method.

(4) Impact resistance: The lens was manufactured with a center thickness of 1.8mm and a diameter of 80mm and subjected to a falling ball test using steel balls of 68g at a height of 127cm (according to the FDA standard). The thing which did not pass was defined as Ｘ.

(5) Heat resistance: Keep the lens at 130 ℃ for 2 hours, if there is no change of deformation, crack, yellowing etc. If the change is severe, it is represented by Ｘ.

(6) Dyeing property: In the dyeing bath, dyeing is performed simultaneously with diethylene glycol bisallylcarbonate resin and dyed at the same or higher level by visual observation. It was assumed that falling.

(7) Weatherability: The lens was set in a weather resistance tester equipped with a sunshine carbon discharge lamp, and the lens was taken out after 200 hours and the color was compared with the lens before the test. If there is no change in color When it turned slightly yellow, (triangle | delta) was changed and it turned into yellow when it turned yellow.

(8) Solvent resistance: After immersing the plastic lens in acetone and methylene chloride for 2 hours, if there is no crack or deformation of the plastic lens, , If present.

From the above Table 1, the high refractive index optical lens obtained by curing the resin composition for an optical lens according to the present invention has good physical properties such as weather resistance, heat resistance, dyeing property, optical distortion, and the like, unlike a resin comprising a conventional epoxy and acrylic acid reaction. In addition, it can be seen that there is an advantage that the light weight of the lens is low density.

As described above, the resin composition for an optical lens according to the present invention not only has a medium refractive index and a high Abbe number, but also has a lightweight three-dimensional crosslinking bond, and has weather resistance, heat resistance, dyeing property, light safety, visible light transmittance, and polishing property. Etc. It can be used to manufacture a medium refractive index optical lens with good physical properties.

Claims (7)

(A) 10 to 50% by weight of a bifunctional or higher epoxydiacrylate compound having a bisphenol A skeleton represented by the following formula (1); [Formula 1] (Wherein R 1 is a methyl group and n is an integer from 2 to 4). (B) 0 to 40% by weight of a bifunctional or higher bisphenol A epoxy diacrylate compound represented by the following Chemical Formula 2; [Formula 2] (Wherein R 1 is a methyl group, R 2 is hydrogen or a methyl group and n is an integer from 2 to 5). (C) 0 to 20% by weight of an aliphatic compound having three or more acrylic functional groups; (D) 10 to 30% by weight aliphatic acrylic acid compound; (E) 0 to 25% by weight of an aromatic allyl compound containing at least one functional group; (F) 5 to 30% by weight of an aliphatic compound having two or more hydroxyl groups and two or more acrylic groups; And (G) The resin composition for low specific gravity and medium refractive index optical lenses containing 5-20 weight% of aliphatic methacrylate compounds which have two or more acrylic groups. The resin composition of claim 1, wherein the compound represented by Chemical Formula 1 is a 4,4- (1-methylethylidene) bisphenol polymer having chloromethyloxirane and 2-propenoate bonded thereto. According to claim 1, wherein the compound represented by the formula (2) is epichlorohydrin and tetraethylene oxide added bisphenol A dimethacrylate, epichlorohydrin and diethylene oxide added bisphenol A diacrylate, epi Bisphenol A dimethacrylate to which chlorohydrin and decaethylene oxide is added, and a mixture thereof is selected from the group consisting of optical lenses. The aliphatic compound having at least three acrylic functional groups (C) is trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, triethylolpropane trimethacrylate, triethylolpropane triacryl. Resin composition for an optical lens, which is selected from the group consisting of a rate and mixtures thereof. The aliphatic acrylic acid compound according to claim 1, wherein the (D) aliphatic acrylic acid compound is methacrylic acid, and the (F) aliphatic compound having two or more hydroxyl groups and two or more acrylic groups is hexanediol diacrylate, and two (G) compounds. The aliphatic methacrylate compound which has the above acryl group is a triethylene glycol dimethacrylate resin composition for optical lenses. The method of claim 1, wherein the (E) aromatic allyl compound is styrene, alphamethylstyrene, alphamethylstyrene dimer, o-divinylbenzene, m-divinylbenzene, p-divinylbenzene, m-diisopropenylbenzene And a resin composition for an optical lens is selected from the group consisting of these. The optical lens manufactured by radically polymerizing the resin composition for optical lenses of any one of Claims 1-5.