JPH11305001A - High-refractive index photosetting resin lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosetting resin lens which has superior optical characteristics and mechanical characteristics and is suitable for mass production due to the simplification of production process is possible. SOLUTION: The copolymer for this lens is obtained by photopolymerizing a composition containing 10 to 60 wt.% tri-or higher functional (thiol), 30 to 80 wt.% a compd. having bi-or higher functional acryl, methacryl or vinyl group and 0 to 50 wt.% monomer copolyermizable therewith. The copolymer has a refractive index of 1.58 or higher, a specific gravity of 1.30 or less and an Abbe number of 34 or greater.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens made of synthetic resin, and more particularly to a lens made of synthetic resin which is suitable for mass production because the manufacturing process can be simplified, and has excellent optical and mechanical characteristics. is there.

[0002]

2. Description of the Related Art Conventionally, various inorganic glasses and synthetic resins have been used as optical lens materials. Various physical properties are required for optical lens materials. For example, in the field of spectacle lenses, high refractive index, high Abbe number, and low specific gravity are extremely important. That is, if the lens used has a high refractive index and a low specific gravity, the lens can be made thinner and lighter, and if the lens has a high Abbe number, light dispersion is small and a comfortable wearing feeling can be obtained. It is.

[0003] Therefore, the refractive index of eyeglass lens materials tends to increase year by year, and the tendency is particularly remarkable in synthetic resin lenses which are extremely light in weight as compared with inorganic glass.

In the field of spectacle lenses, as a material of a synthetic resin lens, as a representative example of the initial stage, there is a material called "CR-39" made from diethylene glycol bisallyl carbonate. However,
Since this material has a refractive index of about 1.50, the entire lens becomes thick, and is not satisfactory as an eyeglass lens. In addition, since a very long heat curing time is required during lens production, the production efficiency is poor. On the other hand, as a synthetic resin lens material having a high refractive index, a urethane resin material obtained by thermally polymerizing thiol and isocyanate (JP-A-2-270859), a prepolymerized product of thiol and vinyl monomer (pre-polymer) (JP-A-4-57831) and a material using a novel sulfur compound (JP-A-8-57831).
No. 183816). In fact, some synthetic resin lenses obtained by polymerizing these materials have achieved a refractive index of 1.60 or more.

[0005] On the other hand, as a polymerization method for a lens material, there is a method using so-called photopolymerization in which active energy rays such as ultraviolet rays are irradiated. For example, in JP-A-59-87129, a high-refractive-index synthetic resin lens is obtained in a short time by photopolymerizing a syrupized epoxy (meth) acrylate. 1933
No. 13 discloses a method for producing a lens with small residual stress distortion by polymerizing using both irradiation of active energy rays and heat treatment.

[0006]

However, the material obtained by urethane polymerization of thiol and isocyanate is a synthetic resin obtained by a urethane reaction, and has a high refractive index and a high refractive index.
Although a lens having a high Abbe number and excellent impact resistance can be obtained, since the urethane reaction is a reaction accelerated by heat, it is difficult to synthesize it by photopolymerization. Therefore, it is inevitable to use a method by thermal polymerization, which requires a long heat curing time, and is not suitable for mass production. A material obtained by preparing a prepolymerized product (prepolymer) of a thiol and a vinyl monomer is capable of photopolymerization that can be polymerized in a short time, but requires a complicated prepolymerization. It is difficult to reduce the manufacturing time. In addition, many of the materials using the new sulfur compounds can be photopolymerized and can reduce the working time, but mass production technology has not been established because of the new substances. Moreover, the cost is high, the specific gravity is high,
There are many problems, such as insufficient properties required for an optical lens such as impact resistance, Abbe number, dyeability, and transparency.

On the other hand, in the method of manufacturing a lens using so-called photopolymerization, the polymerization time of photopolymerization is shorter than that of thermal polymerization, so that the lens manufacturing time can be reduced. Therefore,
Photopolymerization appears to be a very effective manufacturing method for mass production of lenses. However, for example, JP-A-59-8
The material having a high refractive index disclosed in Japanese Patent No. 7129 has a problem that the impact resistance and the Abbe number are low, and the characteristics required for an optical lens cannot be sufficiently obtained. In addition, since a pre-polymerization step is required for photopolymerization, the operation is complicated, and there is a problem that a reduction in lens manufacturing time cannot be achieved.

As described above, a material having a high refractive index and excellent impact resistance has a problem in mass production due to difficulty in photopolymerization, and a material having a high refractive index that can be photopolymerized is difficult. In addition, there is a problem that the required characteristics of the optical lens, such as impact resistance and Abbe number, are not sufficiently provided, or a complicated operation process is required, so that the operation time cannot be reduced. Therefore, a material capable of easily producing a lens having a high refractive index, a high Abbe number, a low specific gravity, and sufficient characteristics required for an optical lens using photopolymerization, that is, a lens made of a high refractive index photocurable resin. If it can be provided, it is possible to easily and easily mass-produce an excellent lens whose thickness and weight have been reduced.

Accordingly, an object of the present invention is to provide a photo-curable resin lens which is excellent in optical characteristics and mechanical characteristics and which is suitable for mass production because the production process can be simplified.

[0010]

The present invention solves the above-mentioned problems by photopolymerizing specific constituents. That is, 10 to 60% by weight of a trifunctional or higher thiol, which is a radical polymerizable component capable of photopolymerization, is used.
And a composition containing 30 to 80% by weight of a compound having a bifunctional or higher acrylic, methacrylic or vinyl group, and 0 to 50% by weight of a monomer copolymerizable therewith, by photopolymerization. Having a refractive index of 1.5
A lens made of a photocurable resin, having a specific gravity of 8 or more, a specific gravity of 1.30 or less, and an Abbe number of 34 or more.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The photocurable resin of the present invention contains a trifunctional or higher thiol in an amount of 10 to 60% by weight, preferably 20 to 60% by weight.
It contains 50% by weight. The reason for this is that when less than 10% by weight of trifunctional or more thiol, impact resistance, Abbe number,
This is because it becomes difficult to obtain characteristics required for the optical lens such as dyeability, and when the content exceeds 60% by weight, sufficient shape stability and heat resistance as the optical lens cannot be obtained.

Examples of trifunctional or higher functional thiols include trimethylpropane tristhioglycolate (TMTG),
Trimethylolpropane tristhiopropionate (T
MTP), pentaerythritol tetrakisthioglyconate (PETG), pentaerythritol tetrakisthiopropionate (PET)
P) and other four-functional sulfur compounds, and others.
It is not limited to these.

The photocurable resin of the present invention contains 30 to 80% by weight, preferably 40 to 70% by weight of a compound having a bifunctional or more functional acrylic, methacrylic or vinyl group. The reason for this is that if the amount of the compound having a bifunctional or higher acrylic, methacrylic, or vinyl group is less than 30% by weight, it becomes difficult to obtain the heat resistance required for an optical lens, and more than 80% by weight. In this case, it is difficult to obtain characteristics required for the optical lens, such as impact resistance, Abbe number, and stainability.

Examples of compounds having a bifunctional or higher acrylic, methacrylic or vinyl group include neopentyl glycol diacrylate (NPG), polyethylene glycol diacrylate (A-400) and tetramethylol methane triacrylate (TMM-3). ), Multifunctional acrylates such as multifunctional acrylate mixture (2C), 2
-Hydroxy-1,3-dimethacryloxypropane (7
01), polyfunctional methacrylates such as 2,2-bis (4-methacryloxypolyethoxyphenyl) propane (BPE-500) and trimethylolpropane trimethacrylate (TMPT), divinylbenzene (DVB), and trivinylbenzene (TVB) And the like, but are not limited thereto.

The photocurable resin of the present invention may further contain, if necessary, a monomer copolymerizable with the above components in addition to the above components. However, 50% by weight
If the amount exceeds the range, it becomes difficult to obtain sufficient heat resistance as an optical lens, so the range of 0 to 50% by weight is preferable.

At this time, any monomer can be used as long as it can be copolymerized with the above-mentioned components. Examples include, but are not limited to, styrene (St), α-methylstyrene dimer (MSD), 2-hydroxyethyl methacrylate (HEMA), lauryl acrylate (LA), and the like.

The photocurable resin of the present invention can reduce the viscosity of the composition and make the composition sufficiently fluid by the combination of the above-mentioned components. After the injection, it is possible to carry out the photopolymerization collectively, and therefore, it is possible to produce easily and at low cost.

In the photopolymerization, known photopolymerization initiators such as acetophenones and benzophenones can be used as the photopolymerization initiator, and a composition to which the photopolymerization initiator has been added in advance can be used, for example, in a casting container. After the injection, a high molecular weight copolymer can be obtained by a method such as irradiation with ultraviolet light (UV). Examples of the photopolymerization initiator at this time include α-hydroxyisobutylphenone, benzoin isobutyl ether, 2-chlorothioxanthone, and the like, but are not limited thereto.

The mixture of the components may contain a coloring agent, a heat stabilizer, and other auxiliary materials, if necessary. Further, a hard coat agent, a non-reflective coat, or another surface coat can be applied to the surface of the obtained copolymer.

The photocurable resin of the present invention is characterized in that it is a copolymer as described above. Therefore, in addition to the cast polymerization method, the photocurable resin is cut after obtaining a plate material or other copolymer. It can also be manufactured by the method of dispensing.

[0021]

The present invention will be described in more detail with reference to the following examples.
The present invention is not limited to these. In addition, the evaluation methods of the obtained various physical properties are as follows.

A test piece having a refractive index of 10 mm × 20 mm × 3 mm was prepared, and the refractive index at room temperature (20 ° C.) was measured using “Abe Refractometer 1T” manufactured by Atago, using α-bromonaphthalene as a contact liquid. It was measured.

Abbe Number The Abbe number was measured by the same measuring device and measuring method as used in the above-mentioned refractive index measurement.

A test piece having a specific gravity of 10 mm × 20 mm × 3 mm was prepared, and the specific gravity at room temperature (20 ° C.) was measured using “SGM-6” manufactured by METTLER TOLEDO.

Impact Resistance Ten test samples having a diameter of 78 mm, a radius of curvature of 0.1 m, and a center thickness of 2 mm were prepared, and a steel ball weighing 16.2 g (diameter 10/16 inch) was weighed 1.27 m. In accordance with the FDA falling ball impact strength standard, the sample was determined to be good if none of the ten samples were broken, and was judged to be defective if one of the samples was broken.

Stainability A dye solution is prepared by mixing 1 g each of Seiko Blacks Brown manufactured by Hattori Seiko Co., Ltd. and 1000 g of pure water with an auxiliary agent, and the obtained lens is added to the dye solution at 92 ° C. for 10 minutes. Dyeing is performed by immersion, and the total light transmittance is measured using an ultraviolet / visible spectrophotometer “UV-2200” manufactured by Shimadzu Corporation. And

Transparency A flat plate having a center thickness of 2.0 mm and a radius of 60 mm was prepared, and the haze was measured using "HGM-2DP" manufactured by Suga Test Instruments Co., Ltd. Those exceeding 3 were regarded as defective.

Example 1 40 g of PETG, 45 g of DVB, 15 g of 2C,
The upper part is measured in a 200 ml beaker, and the photopolymerization initiator I
RGACURE 184 (manufactured by Nippon Ciba Geigy)
After adding 00 ppm and stirring thoroughly, two glass plates
Into a casting mold consisting of
In irradiation device, irradiation dose 800mw / cm ^Two , Irradiation distance 5
UV polymerization was performed under the conditions of 0 cm and irradiation time of 10 min.
Was. After that, take out the copolymer from the casting mold and complete
Product was obtained.

The obtained copolymer had a refractive index of 1.58 or more, an Abbe number of 34 or more and a specific gravity of 1.30 or less, and a molded article having good impact resistance, dyeing properties and transparency was obtained.

Examples 2 to 4 The polymerization compositions were mixed at the composition ratios shown in Table 1, and a photopolymerization initiator IRGACURE 184 (manufactured by Nippon Ciba Geigy) was used.
Was added to a casting mold composed of two glass plates and a gasket, and the resulting mixture was irradiated with an ultraviolet ray at an irradiation dose of 800 mw / cm ² , an irradiation distance of 50 cm, and an irradiation time of 10 min. UV polymerization was performed. Thereafter, the copolymer was taken out of the casting mold to obtain a finished product.

The obtained copolymers were able to obtain physical properties as shown in Table 1. In Examples 2 to 4,
All had a refractive index of 1.58 or more, an Abbe number of 34 or more and a specific gravity of 1.30 or less, and a molded article having good impact resistance, dyeing properties, and transparency was obtained.

Comparative Example 1 As a comparative example, 2
A compound having a methacrylic group or vinyl group having
More than 0% by weight was blended, and the same photopolymerization as in the above example was performed with the composition shown in Comparative Example 1 in Table 1. as a result,
In Comparative Example 1, not only the refractive index was less than 1.58 but also the total light transmittance after dyeing exceeded 40%, and the dyeability was poor.

Comparative Example 2 As a comparative example, ethylene glycol bisthioglycolate, which is a bifunctional thiol, was blended.
The same photopolymerization as in the above example was carried out with the composition shown in the above.
As a result, the lens obtained in Comparative Example 2 was insufficient in hardness as it was soft even at room temperature, and damage was confirmed in four out of ten lenses in an impact resistance test, and the impact resistance was poor. there were.

Comparative Example 3 As a comparative example, a thiol having a functionality of 3 or more was blended in an amount exceeding 60% by weight, and an acrylic compound having a functionality of 2 or more was incorporated in an amount of 30% by weight.
With the composition shown in Comparative Example 3 in Table 1, the same photopolymerization as in the above example was performed. As a result, the lens obtained in Comparative Example 3 had a refractive index of less than 1.58 and a specific gravity of 1.
Not only the hardness exceeded 30, but also the hardness was insufficient as softer even at room temperature. Further, in the impact resistance test, breakage was confirmed in all ten lenses, and the impact resistance was poor.

Comparative Example 4 As a comparative example, styrene, which is a monofunctional vinyl compound, was added in an amount exceeding 50% by weight, and photopolymerization was carried out in the composition shown in Comparative Example 4 in Table 1 in the same manner as in the above example. Was. as a result,
The lens obtained in Comparative Example 4 not only has a refractive index of less than 1.58, but also has insufficient hardness as it is soft even at room temperature, and breaks into 5 out of 10 lenses in an impact resistance test. Was confirmed, and the impact resistance was also poor.

[0036]

[Table 1]

[0037]

According to the photo-curable resin lens of the present invention, a lens having a high refractive index, a high Abbe number, a low specific gravity, a high impact resistance and an excellent total balance can be easily produced by photopolymerization. It is a simplified process suitable for mass production.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08F 290/06 C08F 290/06 C08G 75/04 C08G 75/04

Claims (1)

[Claims] 1 to 10% by weight of a trifunctional or higher functional thiol, 30 to 80% by weight of a difunctional or higher functional compound having an acryl, methacryl or vinyl group, and a monomer copolymerizable therewith. Is a copolymer obtained by photopolymerizing a composition containing 50 to 50% by weight, and has a refractive index of 1.
A lens made of a photocurable resin, having a specific gravity of 58 or more, a specific gravity of 1.30 or less, and an Abbe number of 34 or more.