JPS6044327B2 - Manufacturing method of resin for high refractive index lenses - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a relatively high refractive index (refractive index of 1.53 or more,
The present invention relates to a method for producing a three- or four-component resin suitable as a resin for lenses (preferably 1.55 or higher).

More specifically, the present invention relates to a method for producing a resin for a high refractive index lens having a three-dimensional structure obtained by copolymerizing liquid monomers consisting of three or four components.

The purpose of the present invention is to be lightweight, have good impact resistance, have high surface hardness and high transparency, and have high dimensional stability and heat distortion temperature, and are easy to process. The purpose of this invention is to provide a resin for high refractive index lenses that has excellent properties.

Processability here refers to the possibility of cutting, roughening, or polishing to produce lenses, etc. by mechanical processing of semi-finished lenses (semi-lenses), the possibility of machining processability for making eyeglass frames, dyes, etc. This includes the possibility of dyeing in hot water with dissolved (or dispersed) water, the possibility of antireflection coating in a vacuum evaporator, and the possibility of coating with a hard coating using silicone resin paint. Until now, resin for lenses,
In particular, diethylene glycol bisallyl carbonate called CR-39 has been mainly used in the market as a resin for eyeglass lenses.

When this monomer is polymerized in the presence of a radical polymerization initiator such as diisopropyl peroxydicarbonate (hereinafter abbreviated as 1PP), it becomes lightweight (approx.
(specific gravity), has good impact resistance, high surface hardness, high transparency, dimensional stability and heat distortion temperature, and has excellent processability, and is already widely used. . However, the refractive index of this resin. is 1.
50, it has a refractive index that is lower than the refractive index of 1.52 to 1.53 of crown glass commonly used for eyeglasses, and therefore has a refractive index of at least 1.53 or more, preferably 1.55 or more, In addition, there has been a desire for a resin for lenses that has other properties equivalent to or better than CR-39 resin. This kind of lens resin is used for the purpose of reducing the thickness of high-grade eyeglass lenses, and for the purpose of eliminating chromatic aberration, spherical aberration, coma aberration, etc. by combining two or more lenses. Helpful.
Some fusible resins, such as polycarbonate and polystyrene, have a high refractive index, but they have low dimensional stability and poor processability, making them unsuitable for use in eyeglass lenses. After all, it is necessary to be infusible and insoluble. One of the methods for obtaining an infusible, insoluble, three-dimensional lens resin with a high refractive index is to use a monomer having a pine nucleus in its molecule. Among them, derivatives from bisphenol A that are easily obtained on an industrial scale, such as 2,2-bis(
4-methacryloxyethoxyphenyl)propane, etc., or 2,2-bis(4-methacryloxyethoxyphenyl)3,5
Many methods have been proposed in which copolymerization components such as -dibromphenyl)propaO are used. Japanese Patent Publication No. 55-137
No. 47, JP-A-56-166214, JP-A-57-2
3P No., JP-A-57-102601, JP-A-57-1
No. 04101, JP-A-57-104901, JP-A-5
No. 7-116301, JP-A-57-28117, etc. propose that each of these copolymer components be used together with other copolymer components to obtain a characteristic copolymer. . However, what these ideas have in common is that they use a so-called monofunctional monomer, which has only one polymerizable double bond, as one of the main components, as another copolymerization component. be.

Contains a large amount of such monofunctional monomers (for example, 3% by weight)
Copolymers (including those listed above) strongly exhibit the properties of their monomers, and even though they are infusible and insoluble, they do not ensure strong dimensional stability, high heat distortion temperature, and high surface hardness. hard.

In manufacturing plastic lenses for eyeglasses, polishing is often used in addition to casting.

It is an essential condition for producing good polished lenses at a high yield that this polishing material (semi-finished lens) has strong dimensional stability. Furthermore, since spectacle lenses are strongly tightened by spectacle frames during use, permanent distortion is likely to occur, and for this reason as well, it is an important condition that spectacle lenses have strong dimensional stability. The present inventors have developed a lens that has a high refractive index and is characterized by light weight, high impact resistance, high transparency, strong dimensional stability, and high heat distortion temperature, which are the characteristics of the CR-39 plastic lens currently available on the market. The present invention was achieved as a result of intensive research aimed at developing a resin for lenses that possesses all of the characteristics of , high surface hardness, and excellent workability.

That is, the present invention provides (1) the first monomer having the structural formula [1] (where R represents hydrogen or a methyl group, m≧1, n≧1 and m
5 to 95% by weight, preferably 20 to 6% by weight of one or a mixture of two or more compounds represented by (+n represents a number greater than 4 and less than or equal to 6), and diallyliso as the second monomer. Phthalate 5-95% by weight, preferably 40-8% by weight
and benzyl methacrylate 0.5~ as the third monomer
1% by weight, preferably 1 to 5% by weight, and diethylene glycol bisallyl carbonate O to 3 as the fourth monomer.
0% by weight in the presence of a radical polymerization initiator, and (2) a resin useful for a three-component or four-component high refractive index lens, and (2) a structural formula [1] as the first monomer.
One type or mixture of two or more types of compounds shown in 5 to 95
% by weight, preferably 20-6% by weight, 5-95% by weight of diallyl isophthalate as the second monomer, preferably 40-8% by weight, and 0.5% by weight of dialkyl maleate as the third monomer. ~1% by weight, preferably 1-5% by weight, 4th
A method for producing a resin useful for 3-component or 4-component high refractive index lenses, which is obtained by copolymerizing 0 to 3% diethylene glycol bisallyl carbonate as a monomer in the presence of a radical polymerization initiator. This is what we provide.

The resin for lenses obtained by the manufacturing method of the present invention can easily have a refractive index of 1.55 or more when combined, and has excellent dimensional stability. When used as a product lens, it can be manufactured easily and efficiently, and there is almost no risk of permanent deformation after it is inserted into an eyeglass frame.

The first monomer represented by structural formula [1] used in the production method of the present invention is mainly synthesized by the following method.

That is, bisphenol A is treated with ethylene oxide in the presence of an alkali (however, m≧1, n≧1 and m+n exceeds 4 and 6
Create the following numbers.

At this time, the value m+n represents the average number of added moles of ethylene oxide, so it may be not only an integer but also a decimal number (for example, 4.2 or 5.1). Of course, the values of M and n can be not only integers but also mixed decimal numbers. The compound of formula [a] thus obtained was added to methyl acrylate (
or ethyl) or methyl methacrylate (or ethyl) in a conventional manner to obtain the first monomer of structural formula [1].

When the value of m+n of this first monomer is 4 or less, the impact resistance as a resin for lenses decreases.

Furthermore, if the phenolic hydroxyl group of bisphenol A remains in the resin in a free state, it causes discoloration that is undesirable for use as a lens, so it is necessary to completely block this phenolic hydroxyl group. For this purpose, it is insufficient if the value of m+n is less than 4, so it must be a number greater than 4. However, the value of m+n is 6
If it exceeds this range, the resin becomes too soft, making it unsuitable for use in lenses, etc., and does not meet the purpose of the present invention. Therefore, it is essential that the values of m and n be within the above range. When the value is within the range of the present invention, the polymerization stock solution (by adding a catalyst, etc. to the monomer composition of the present invention,
Prepolymerized. The viscosity and fluidity of these products (the same applies hereinafter) are often moderate, and their excellent workability is also cited as an advantage. The amount of the first monomer used can range from 5 to 95% by weight, but preferably 20 to 6% by weight is recommended.

The second monomer, diallylisophthalate, contains 2 as an impurity.
Diallyl orthophthalate less than or equal to heel weight % and w weight %
There is no problem in containing the following diallyl terephthalate.

If the content of diallyl orthophthalate exceeds 2% by weight, the transparency of the resulting resin may decrease, and if the content of diallyl terephthalate exceeds 1% by weight, the fluidity of the polymer stock solution may decrease. Avoid it because it is. The amount of the second monomer used can range from 5 to 95% by weight,
Preferably, a saliva amount of 40 to 8% is recommended. The first monomer and the second monomer are the main components of the monomer group forming the resin for high refractive index lenses of the present invention.

The characteristics and roles of both are that the former has a high refractive index, promotes impact resistance, and has a relatively high polymerization rate, whereas the latter has a high refractive index, promotes surface hardness, and has a relatively low polymerization rate. . When these two are mixed in an appropriate ratio, a high refractive index, high impact resistance, high surface hardness, and appropriate polymerization rate can be obtained. This is due to the good compatibility of the two to bring about excellent effects. The third monomer, benzyl methacrylate or dialkyl maleate, accelerates the reaction and helps complete the reaction.

Rock is a component whose purpose is to act as a promoter. The mixing amount can be 0.5 to 10% by weight, but preferably 1 to 5% by weight.
% by weight is recommended. The third monomer is a so-called monofunctional monomer that has only one polymerizable double bond, and when it is mixed in a large amount, dimensional stability and
Both heat distortion temperature and surface hardness decrease. Moreover, if it is too small, it is difficult to expect the reaction to be completed. For this reason, the mixing proportions described above have been chosen. The alkyl group of the dialkyl maleate may have 1 to 8 carbon atoms.

For example, dimethyl maleate. Examples thereof include diethyl maleate, dipropyl maleate, dibutyl maleate, ethyl butyl maleate, diisoamyl maleate, di-2-ethylhexyl maleate, and dioctyl maleate. The reason for using the fourth monomer, diethylene glycol bisallyl carbonate, is to provide a means for adjusting the refractive index to a rather low value.

Therefore, it is not necessarily an essential component for the purpose of this invention. And by adding this substance, Ab
In many cases, the be number can be adjusted slightly higher. The amount of this fourth monomer mixed can be 0 to 3% by volume. If more than this amount is mixed, the amount of light transmitted will be significantly reduced due to poor compatibility, which will not meet the purpose of the present invention. The above-mentioned IPP is most recommended as a radical polymerization initiator when polymerizing the monomer groups explained above by selecting a mixing ratio according to the purpose, but other methods include benzoyl peroxide, lauroyl peroxide, t- Butyl peroxyisobutyrate and the like can also be used.

The amount of catalyst added is usually 0.1 to 5% by weight, but 0.5
~4% by weight is commonly used. In addition to the catalyst, it is also necessary to mix in one or more UV absorbers (commercially available products, for example, benfuzophenone), selected as appropriate. This is because it is important to prevent plastic lenses from yellowing and deterioration of their physical properties due to aging when exposed to sunlight, and to protect the eyes, especially in the case of eyeglass lenses, to block out as much ultraviolet rays as possible. This is because it is desirable. In the polymerization and molding process in the present invention, two well-polished glass molds are usually placed in parallel through a gasket made of a chemically inert rubber-like elastic material (such as ethylene-vinyl acetate copolymer). They are assembled so that they are lined up, and a liquid (polymerization stock solution) prepared by prepolymerizing a mixture of the above-mentioned monomers, a polymerization catalyst, and an ultraviolet absorber is poured into the space.

Prepolymerization is an operation in which the mixed solution is heated and stirred gently in advance to slightly increase the viscosity of the solution, thereby preventing leakage of the polymerization stock solution and at the same time reducing the adverse effects of volume shrinkage during polymerization. Once the injection is complete, it is placed in a heated oven to polymerize. Polymerization time is 10~
A period of 3 Vf is common, but a period of 15 to 2 hours is recommended for convenience of operation. To give an example of temperature control of the heating furnace, during the first 213 hours of the total polymerization time, the temperature is from 30°C to 8°C.
The temperature was gradually raised to 0 °C, and during the subsequent 113 minutes, the temperature was gradually raised from 80 °C to 100 °C until 30 minutes before the end point, and the last 3 powders were kept at 105 to 110 °C to polymerize. complete. Gaskets often lose their shape at temperatures of 90 to 100 degrees Celsius, so it is better to remove them at this point.

After the entire heating time is complete, remove the lens from the mold. It is better to clean this lens with an aesthetic solvent. The lens made by the above procedure can be put to practical use as a product as it is, but when polymerizing by casting, only the front surface of the lens is formed with a predetermined shape and a turn, and the rear surface is formed with a temporary curve (usually a -2 to -6 curve). ) by making a thick lens (usually 5 to 20 TWL thick) as a material and roughening and polishing only the rear surface, it is also possible to make a product lens of a predetermined diopter.

The resin for lenses obtained in this manner has particularly excellent suitability for roughing and polishing, and it is possible to quickly and reliably manufacture desired lenses at a high yield.

Further, lenses made of the lens resin produced by the manufacturing method of the present invention can be easily dyed using a suitable dye such as a disperse dye at a dye bath temperature of about 85 to 95°C.

Moreover, almost no change in the curve of the surface of the lens or the number of diopters due to staining is observed. These phenomena indicate that the resin for lenses manufactured by the manufacturing method of the present invention has high dimensional stability, high heat distortion temperature, and excellent processability. EXAMPLES In order to explain the present invention more specifically and in detail, Examples are shown below.

However, the present invention is not limited to these Examples. The testing methods for various physical properties shown in Examples (and Comparative Examples) are as follows. (1) Refractive index: Measured at 20°C using an Atsube refractometer.

Monobromnaphthalene was used as a contact liquid. (2) Light transmittance: Measured using an integrating sphere phase meter manufactured by Nippon Seimitsu Kogaku Co., Ltd.

(3) Impact resistance: A flat plate with a thickness of 2wrL and a diameter of 15mm. gT
W11 Steel balls weighing 16.2y are dropped from a height of 127 in order, and the test is repeated 5 times, with those that do not break being considered good.

(4) Pencil hardness: Based on the JIS K54OO test method.

Examples 1 to 10 2,2-bis(4-acryloxypolyethoxy,:3phenyl)propane with an average number of added moles of ethylene oxide of 4.2 or 5.1 or ethylene oxide with an average number of added moles of 4.3 2,2-bis(4-methacryloxypolyethoxyphenyl)propane, diallyl isophthalate, benzyl methacrylate, and (in Examples 9 and 10) diethylene glycol bisallyl carbonate were mixed in the composition shown in Table 1. Then, 0.1% by weight of IPP was added as a radical polymerization initiator, and the mixture was heated and stirred at 70°C to increase the viscosity to about 100 centipoise (at 20'C) (prepolymerization).

After cooling this to room temperature, 3. % IPP is added to prepare a polymerization stock solution. This was poured into a casting mold consisting of two glass plates with a diameter of 65 mm and a gasket made of ethylene-vinyl acetate copolymer, and cast polymerization was performed. Polymerization was carried out using a hot air circulation furnace for the first 1'2f1f! Gradually raise the temperature from 30°C to 80°C for 3 hours to polymerize, then raise the temperature to 90°C for 2 hours and 3 minutes, remove the gasket at this step, and raise the temperature to 100°C for the next 3 hours. The temperature was further increased to 105°C over the next three minutes to complete the polymerization.
Disk-shaped polymer (thickness 2T0fL) after being removed from the furnace and left to cool.
After removing from the glass plate and washing with ethyl acetate, various physical properties were measured and are shown in Table 1. Examples 11-18 In Examples 1-10 above, benzyl methacrylate. A discoidal polymer was prepared using di-n-butyl maleate in place of the rate, and all other conditions were the same, and various physical properties were measured.
It is shown in Table 2.

Comparative Examples 1 to 5 Disc-shaped polymers when monofunctional monomers benzyl methacrylate and dibutyl maleate were added beyond the scope of the present invention, and disc-shaped polymers of polydiallylisophthalate. Polycarbonate and polystyrene disks were prepared in the same manner and by injection molding, and their physical properties were measured and shown in Table 3, and used as comparative data.

As can be seen from Tables 1 to 3, the resin for lenses manufactured by the manufacturing method of the present invention has a high refractive index and a light transmittance of ? It has high hardness and impact resistance, and has proven to be extremely useful as a resin for lenses.

On the other hand, all of the resins of the comparative examples are unsuitable as lens resins.

Incidentally, semi-finished lenses (semi-lenses) were made using the lens resins of Examples 2 and 12, and finished into finished lenses by roughening and polishing, which showed excellent polishability and could easily be polished into lenses with good yield. proved.

Also, this polished lens. When a cast lens with the same composition as 40 was dyed with a disperse dye, it could be dyed beautifully at an appropriate speed, and the surface curve and number of diopters before and after dyeing ζ were... It was found that no change was allowed.

Furthermore, anti-reflective film coating was carried out using the J-vacuum deposition method, and hard coating film coating was performed using the Milicon resin-based paint using the dipping method, both of which were proven to have excellent durability. Note) Explanation of monomer abbreviations in Tables 1 to 3: BAPEPP (4.2): 2,2-bis(4-
Acryloyloxypolyethoxyphenyl)propa
(Moles of ethylene oxide added = 4.2) BMPEPP (
4.3) 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane (number of moles of ethylene oxide added = 4.3) BAPEPP (5.1) 2,2-bis(
4-Acryloyloxypolyethoxyphenyl)propane (number of moles of ethylene oxide added = 5.1) DAIP:
Diaryl isophthalate BzMA: Benzyl methacrylate DBuM: Dibutyl maleate

Claims (1)

[Claims] 1 The first monomer has a structural formula [I] ▲A mathematical formula, a chemical formula, a table, etc.▼[I] (However, R represents hydrogen or a methyl group, m≧1, n≧1, m+n represents a number greater than 4 and less than or equal to 6)
5-95% by weight of the species or mixture of two or more species, preferably 2
0 to 60% by weight, 5 to 95% by weight, preferably 40 to 80% by weight, of diallylisophthalate as the second monomer, and 0.5 to 1% of benzyl methacrylate as the third monomer.
0% by weight, preferably 1-5% by weight, and 0-3% diethylene glycol bisallyl carbonate as the fourth monomer.
1. A method for producing a three-component or four-component resin for high refractive index lenses, characterized by copolymerizing 0% by weight with 0% by weight in the presence of a radical polymerization initiator. 2 Structural formula [I] as the first monomer ▲ Numerical formula, chemical formula, table, etc. ▼ [I] (However, R represents hydrogen or a methyl group, m≧1, n≧1 and m+n exceeds 4, 1 of the compounds represented by (representing a number of 6 or less)
5-95% by weight of the species or mixture of two or more species, preferably 2
0 to 60% by weight, diallyl isophthalate as second monomer 5 to 59%, preferably 40 to 80% by weight, and dialkyl maleate as third monomer 0.5 to 10%.
% by weight, preferably 1-5% by weight, and 0-30% diethylene glycol bisallyl carbonate as the fourth monomer.
% by weight in the presence of a radical polymerization initiator.