JPH01163701A - Plastic lens material - Google Patents

Abstract

PURPOSE:To obtain a material having a high refractive index, excellent impact resistance and small sp. gr. by bringing a component A having a thiol group and a component B having an isocyanate group into reaction and adding a component C which can copolymerize with the component A to the reaction product. CONSTITUTION:The component A of a monomer which has >=1 thiol groups in the molecule and can be radical-polymerized and the component B which has the isocyanate group in the molecule are brought into reaction at the ratio at which the molar ratio of the thiol group and the isocyanate group is 1.05-2. The component C which can copolymerize with the component A is then polymerized at a ratio of 0-80wt.% of the entire part. Since the thiourethane bond by a sulfur atom is formed in this polymer, the material which has the higher refractive index than the refractive index of an ordinary polyurethane bound body, is resistant to impact and has the small sp. gr. is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to plastic lens materials, and more particularly to plastic lens materials containing sulfur atoms.

[Conventional technology]

Nowadays, transparent plastic materials are lightweight,
Because it has various features that cannot be obtained with inorganic glasses, such as high impact resistance and resistance to breakage, ease of processing, and the ability to be dyed, it has begun to be used in many ways as a material for optical lenses.

In particular, as a material for eyeglass lenses for vision correction, it is lightweight,
Plastic lens materials are preferred because essential properties include high impact resistance and ease of dyeing.

Furthermore, plastic lens materials are required to have a high refractive index, and this is because plastic lens materials with a high refractive index can reduce the edge thickness at the periphery of eyeglass lenses, for example. .

Conventionally, the most commonly used plastic lens material for eyeglasses is diethylene glycol bisallyl carbonate resin, but this resin has a relatively low refractive index of around 1.50, and is not necessarily satisfactory in this respect. do not have.

On the other hand, polyurethane resins have been studied in various fields as plastic lens materials with excellent impact resistance. Patent No. 3,907
．． No. 864, US Pat. No. 3,954,584, and others disclose lenses made of polyurethane resin.

However, these polyurethane resin lenses also do not have a sufficiently high refractive index and are not satisfactory in this respect.

Furthermore, as a polyurethane resin having a higher refractive index, one containing a halogen atom is disclosed in Japanese Patent Application Laid-Open No. 58-164.
This method has been proposed in Japanese Patent Publication No. 615, Japanese Patent Application Laid-open No. 133211/1980, and the like. In this way, when containing halogen atoms, especially bromine atoms and iodine atoms, the refractive index of the polymer increases according to the content, but at the same time, the refractive index of the polymer increases according to the content of halogen atoms. The specific gravity of the coalescence increases, and as a result, the light weight, which is the greatest feature of plastic materials, is lost, and the resulting plastic lens material has the advantage of having a large refractive index largely diminished.

Furthermore, a method in which a crosslinked structure is introduced into a polymer molecule by reacting a vinyl monomer containing a hydroxyl group with an isocyanate compound has been proposed in JP-A-58-168614 and other publications.

[Problem that the invention seeks to solve]

As described above, various efforts are being made to find plastic lens materials with high refractive index and excellent impact resistance.
The current situation is that we have not yet achieved something that is fully satisfactory.

The present invention was made based on the above circumstances, and an object of the present invention is to provide a plastic lens material that has a high refractive index, excellent impact resistance, and a low specific gravity.

[Means for solving problems]

In the plastic lens material of the present invention, the following component A is reacted with the following component B in a molar ratio of the thiol group of the component A to the isocyanate group of the component B in a molar ratio of 1:0.5 to 2. and 0 to 80% by weight of the whole
It is characterized in that it consists of a polymer obtained by polymerizing it together with component C below in a proportion such that:

Component A: Monomer having a radically polymerizable unsaturated group with one or more thiol groups in two molecules Component B: Compound having an isocyanate group in the molecule Component C: Monomer copolymerizable with component A [Effects] The plastic lens material according to the present invention has a high refractive index, excellent impact resistance, and has a small specific gravity. The reason why such an effect is obtained is that a thiourethane bond -N-C-3- is formed in this polymer, which makes this polymer basically a urethane with excellent impact resistance. This is because it has the structure of a resin-based resin and contains sulfur atoms in the molecule, which prevents the specific gravity from becoming excessively high and has a high refractive index. That is, the polymer formed by forming thiourethane bonds with sulfur atoms is
It has a higher refractive index than a polymer having a normal polyurethane bond formed by a hydroxyl group and an isocyanate compound, and has a lower specific gravity than a polymer containing a halogen atom.

The present invention will be explained in detail below.

In the present invention, a plastic lens material is obtained by forming a thiourethane bond with component A and component A and forming a polymer by utilizing the polymerizability of component A.

/'4 min used in the present invention is a polymerizable thio compound containing one or more thiol groups (-3H) in the molecule and having a radically polymerizable unsaturated group. This A
The radically polymerizable unsaturated group of the component is usually a vinyl group,
It may be an allyl group, a methacrylic group, an acrylic group, etc., and is not particularly limited.

Specific examples of component A include 2-mercaptoethanol, ethanedithiol, 1.2-7'lopanedithiol, L3-propanedithiol, parahydroxythiophenol, 3-mercapto-1,2-propanedithiol, 1.4 - Reaction products of thiol group-containing compounds such as aliphatic or aromatic mercapto alcohols or dithiols such as butanedithiol, 2-mercaptoalcohol, 2-mercaptoethyl sulfide, and compounds having radically polymerizable unsaturated groups, e.g. Examples include, but are not limited to, esters or allyl ethers of acrylic acid, methacrylic acid, or vinylbenzoic acid.

Component B used in the present invention is an isocyanate compound having an isocyanate group.

This component B is preferably a compound containing two or more isocyanate groups, and by using such a polyisocyanate compound as component B, a crosslinked structure is formed, so that the final polymer obtained has even better impact resistance.

Specific examples of component B include monoisocyanate compounds such as methyl isocyanate, butyl isocyanate, phenyl isocyanate, and octadecyl isocyanate, hexamethylene diisocyanate, octamethylene diisocyanate, inphorone diisocyanate,
Diisocyanate compounds such as dicyclohexylmethane diisocyanate, xylylene diisocyanate, and 4,4'-diphenylmethane diisocyanate, trifunctional or higher functional compounds such as vinyluret reaction products of hexamethylene diisocyanate, compounds with trimer structure, or adduct reaction products with trimethylolpropane. Examples include, but are not limited to, polyisocyanate compounds.

Among the above, aliphatic isocyanate compounds or hexamethylene which produce polymers that are less likely to yellow than aromatic isocyanate compounds, which tend to cause yellowing in the resulting polymers due to heat or light. It is preferable to use a polyfunctional derivative of diisocyanate, etc., which can provide a colorless, transparent and stable polymer required as a plastic lens material.

In a typical method for manufacturing the plastic lens material of the present invention, components A and B are first reacted. Through this reaction, a thiourethane monomer containing a thiourethane bond formed by bonding the thiol group of component A and the isocyanate group of component B and has a radically polymerizable unsaturated group is formed. This thiourethane formation reaction can usually be carried out at a temperature ranging from room temperature to 200°C. In this thiourethane-forming reaction, in order to shorten the reaction time, reaction catalysts used in ordinary polyurethane production, such as dibutyltin dilaurate,
Stannath octoate, dimethyltin dichloride, stannic chloride, etc. can be used as appropriate. The thiourethane formation reaction may be carried out in an organic solvent that is inert to the thiourethane bond formation reaction, and the thiourethane monomer can be obtained by removing the organic solvent after the reaction is completed.

In the above, the ratio of component A and component B is a relative ratio such that the ratio of the thiol group of the component A to the isocyanate group of the component is t:O, 5 to 2 in molar ratio,
In particular, the molar ratio of thiol groups and isocyanate groups is 1:0.
．． It is preferably within the range of 7 to 1.5. If the A component is in excess, the resulting polymer may be discolored, and if the B component is in excess, the resulting polymer may have poor durability.

This thiourethane monomer is then polymerized, thereby forming the polymer that is the plastic lens material of the present invention.

In this polymerization, the above-mentioned thiourethane monomer may be polymerized alone. However, in reality, C is made of a radically polymerizable monomer copolymerizable with component A.
Preferably, it is copolymerized with the components.

This is because the thiourethane monomer, which is a reaction product of component A and component B, may become a viscous liquid or solid. That is, even in such a case, by using component C, the monomer composition to be polymerized can be made into a low viscosity liquid, so that the polymerization process can be easily performed. It is also preferable in that by selecting the type of component C, it is possible to obtain properties suitable for the intended use in the resulting copolymer. From this point of view, the monomer used as component C is preferably a liquid substance with low viscosity.

In addition, when using the C component in this way, the thiourethane-forming reaction can be performed in the presence of the C component.

Specific examples of component C include styrene, α-methylstyrene, and chloromethylstyrene. Aromatic vinyl compounds such as divinylbenzene, allyl compounds such as diallyl phthalate, diallyl isophthalate, diethylene glycol bisallyl carbonate, methyl methacrylate, 2-ethylhexyl methacrylate, n-butyl acrylate, diethylene glycol dimethacrylate, 1.3- Examples include various acrylates and methacrylates such as butanediol diacrylate, phenyl methacrylate), 2,2-bis(4-methacryloxyethoxyphenyl)propane, etc.
It is not limited only to these.

A thiourethane monomer made of the above A component and B component,
The proportion of the C component can be changed depending on the intended use of the plastic lens material, but in the present invention, the proportion of the thiourethane monomer is 20 to 20% of the total amount.
100% by weight, and the C component ranges from 0 to 80% by weight. When the proportion of thiourethane monomer is 20% by weight, the proportion of thiourethane bonds is small, so
It is not possible to obtain a copolymer with excellent impact resistance.

In addition, the ratio of thiourethane monomer to all monomers is 9
If it exceeds 0% by weight, the viscosity of the monomer composition may become excessively high, and in this case, the monomer composition does not have sufficient fluidity, so it is used for cast polymerization. It becomes impossible to directly inject into a mold, and the cast polymerization method, which is preferred as a method for manufacturing plastic lenses, cannot be used. Therefore, from this point of view, the proportion of the thiourethane monomer is preferably within the range of 30 to 90% by weight.

As a method for polymerizing the above-mentioned thiourethane monomer alone or in combination with component C, known methods such as suspension polymerization, emulsion polymerization, or cast polymerization may be used, depending on the use of the final polymer obtained. method can be adopted. When a bifunctional or more functional polyisocyanate compound is used as the B component and when the C component is a monomer having two or more polymerizable unsaturated groups, the copolymer formed has a crosslinked structure. This is preferable in that it provides excellent impact resistance, but it is generally difficult to mold. Therefore, in this case, it is difficult to use a suspension polymerization method or an emulsion polymerization method in which fine particulate polymers are formed, so a cast polymerization method is used. When both the thiourethane monomer and component C are monofunctional, emulsion polymerization or suspension polymerization can be used.

When the plastic lens material of the present invention is obtained by the cast polymerization method 1ζ, glass, plastic, metal, etc., which are plate-shaped, lens-shaped, cylindrical, prismatic, conical, spherical, or otherwise designed according to the intended use, can be used. A mold or mold made of is prepared, and a single thiourethane, which is a reaction product of components A and B in a predetermined ratio, and the necessary component C are added to it as a radical polymerization initiator. A monomer composition obtained by mixing with the above-mentioned components may be injected, and the mixture may be polymerized by raising the temperature.

During polymerization, various additives can be added to the monomer composition as necessary. Here, as an additive,
Colorants, ultraviolet absorbers, antioxidants, heat stabilizers, and others are used depending on the intended use of the resulting lens.

The obtained molded product may be used as the desired lens material as it is, or it can be further cut and polished to obtain the desired lens material.

As described above, in order to obtain the plastic lens material of the present invention,
The case where the thiourethane monomer formation reaction between component A and component B is carried out prior to the polymerization reaction has been explained.
It is not essential to perform the thiourethane reaction first. That is, first, component A alone or together with component C
Components are polymerized to some extent to form a prepolymer, the thiol groups of component A in this prepolymer are reacted with component B to form a thiourethane bond, and then the polymerization is completed. You can also do it. Even in these cases, in the finally obtained polymer, A
The proportions of the components B component and C component need to be in the same range as above. Note that by performing the polymerization reaction in advance, there is a possibility that the subsequent thiourethane reaction may not proceed smoothly. In this case, it is preferable to carry out the thiourethane formation reaction first.

The plastic lens material of the present invention obtained as described above is dyed, surface polished, and antistatic treated as necessary to further improve its properties as a lens and improve its surface hardness. In order to increase
Of course, it is also possible to perform secondary processing such as an inorganic or organic hard coat or a non-reflective coat that is applied to ordinary lenses.

Examples of the present invention will be described below, but the present invention is not limited thereto.

Example 1 35.6 g of a monoester of methacrylic acid and ethanedithiol, i.e., 2-mercaptoethylthioester methacrylate, represented by the structural formula %, and inphorone diisocyanate)
Thoroughly mix 24.4 g and 40 g of styrene,
Add 0.01g of dibutyltin dilaurate to this,
A thiourethane reaction was carried out by reacting at 60° C. for 2 hours.

To the obtained liquid, lauroyl peroxide Ig was further added to obtain a monomer composition, which was poured into a glass mold with a spherical inner surface and heated at 50°C for 3
Time: 10 hours at 60℃, 2 hours at 80℃, then 90℃
The polymerization reaction was carried out for 2 hours, and the center thickness was 2.0 mm and the diameter was 7
A concave lens made of a transparent polymer of 5III11 was obtained.

When the refractive index of this lens was measured using an Atsube refractometer, n! =1.560.

Furthermore, this polymer was completely insoluble in common organic solvents such as methanol, ethanol, acetone, and toluene, and was recognized to have a sufficient crosslinked structure.

Furthermore, in accordance with the U.S. FDΔ standard, this lens was subjected to an impact resistance test using the steel ball drop method in which a steel ball weighing 16.33 g was dropped onto a sample from a height of 127 cm, and no damage was found. It was recognized that it had excellent impact resistance.

Further, the specific gravity of this polymer was extremely small at 1.16.

Comparative Example 1 32.4 g of 2-hydroxyethyl methacrylate,
27.6 g of inphorone diisocyanate and 40 g of styrene were thoroughly mixed, a urethane reaction was carried out according to a method similar to Example 1, and a monomer composition obtained from the reaction product was used in a mold. A polymerization reaction was carried out.

The obtained polymer had a refractive index of nτ=1.542 and a specific gravity of 1.13.

From the above, the polymer obtained in Example 1 is the same as that of Comparative Example 1.
It is clear that it has a higher refractive index than that of .

Example 2 Monoester of methacrylic acid and 1,4-butanedithiol, 37.9 g of methacrylic acid 4-mercabutobutylthioester, and inphorone diisocyanate) 22
．． 1 g of styrene and 40 g of styrene were thoroughly mixed, 0.01 g of dibutyltin dilaurate was added thereto, and the mixture was reacted at 60° C. for 2 hours to perform a thiourethane reaction.

1 g of lauroyl peroxide was further added to the obtained liquid to obtain a monomer composition, which was used in Example 1.
Polymerized using a method similar to
A concave lens made of a transparent polymer of m was obtained.

The refractive index of this lens is n%! =1.554.

From the above, it is clear that the polymer of Example 2 has a higher refractive index than that of Comparative Example 1.

Further, when this concave lens was subjected to the same impact resistance test as in Example 1, no fracture was observed, and it was found to have excellent impact resistance.

Claims (1)

[Claims] 1) The following component A is combined with the following component B, and the molar ratio of the thiol group of the component A to the isocyanate group of the component B is 1.
: A polymer with a refractive index characterized by being made of a polymer obtained by reacting at a ratio of 0.5 to 2 and polymerizing with component C below in a ratio of 0 to 80% by weight based on the total. High plastic lens material. Component A: Monomer having a radically polymerizable unsaturated group having one or more thiol groups in the molecule Component B: Compound having an isocyanate group in the molecule Component C: Monomer copolymerizable with component A