JPS61130901A - Production of copolymer for lens having high refractive index - Google Patents

Abstract

PURPOSE:To obtain a lens having an excellent transparency, a weather resistance, a solvent resistance, and an easily polymerizable property and to obtain and uniform dying by using a copolymer composed of divinyl benzene having a high purity and a comonomer capable of a radical polymerization from which a polymer having a specific refractive index is formed. CONSTITUTION:A monomer mixture consisting essentially of 5-80wt% the high purity divinyl benzene (DVB) having >=80wt% purity and <=2wt% nonpolymerisable impurity and 95-20wt% a monomer capable of the radical polymerization and the polymer having >=1.55 the refractive index is polymer ized. The latter monomer shown by the formula wherein R is a hydrogen atom, 1-2C alkyl group, X is a halogen atom except F, (p) is 1-5, (n) is 0-4, is preferably in order to obtain a polymer having a good dyeing property, a high refractive index and a low dispersibility. The copolymer and the titled lens obtd. therefrom having the prescribed properties are prepared by using the prescribed DVB.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for producing a copolymer for high refractive index lenses. More specifically, the present invention is characterized in that high-purity divinylbenzene having a purity of 80% by weight and containing non-polymerizable impurities of 2% by weight or less is used as one component of the copolymer. Production of copolymers.

It is about law.

BACKGROUND OF THE INVENTION Plastic lenses have been widely used in optical products because they are easy to manufacture and lightweight. However, organic lenses generally have a lower refractive index than inorganic glass lenses, and have the disadvantage that when molded into lenses, they must be extremely thick. In addition, it is generally said that they have poorer solvent resistance and heat resistance than inorganic lenses.

Currently, diethylene glycol bisallyl carbonate resin is said to have excellent optical properties as an organic glass for optical lenses, but its refractive index is as low as about /,j, which is a drawback.

On the other hand, research has been conducted in many fields in recent years to obtain organic lenses with high refractive index. Examples include polyvinylnaphthalene, polyvinylcarbazole, polynaphthyl methacrylate, and the like. However, although a high refractive index can be obtained, only those with poor heat resistance and solvent resistance have been obtained.

High refractive index, heat resistance, and solvent resistance are important for lenses, and attempts have been made to copolymerize them with various crosslinking agents in order to impart these properties to lenses. . However, there are few crosslinking agents that have a plurality of polymerizable functional groups and whose polymers have a high refractive index, and a useful crosslinking agent has been desired.

As examples of crosslinking agents that provide high refractive index polymers, compounds with aromatic rings such as diallylphthalate and divinylbenzene are used in some cases, but the former polymers have a relatively high refractive index of /37. Although high, it is generally known that the reactivity of allyl groups as polymerizable functional groups is poor.

Furthermore, divinylbenzene currently used industrially has a purity of less than &0% by weight, and when it is used as a lens material, it has the following various drawbacks. That is.

First, since the divinylbenzene content is low, the crosslinking effect is poor. Moreover, since it contains impurities, polymerization is inhibited. Furthermore, the biggest drawback is that non-polymerizable impurities 5 such as diethylbenzene exist in the lens and dissolve over time, causing the lens surface to become cloudy or dirty.
It may impair weather resistance, or it may cause adverse effects such as subsequent lens surface treatments such as note coating, multi-coating, etc. not being uniformly applied, or the coating layer peeling off easily. happens. Naturally, the optical properties of the lens itself change over time due to the elution of non-polymerizable impurities. Furthermore, when a lens is dyed, the dyeing is often uneven or cannot be dyed sufficiently.

SUMMARY OF THE INVENTION The inventors of the present invention have intensively investigated the search for a crosslinking agent with a high refractive index in view of the above-mentioned current situation, and have found that by using high-purity divinylbenzene, a high refractive index and solvent resistance with less elution of impurities can be achieved. We succeeded in obtaining an excellent copolymer for lenses.

That is, 1. The method for producing a copolymer for lenses according to the present invention is as follows:
, high-purity divinylpenzee y (■) having a purity of 80 weight i-4 or more and non-polymerizable impurities of 2 weight or less
! ~, subjecting to polymerization conditions a monomer mixture whose main components are a radically polymerizable monomer (II) or jQxo-jyokeiji which gives a polymer having 80% by weight and a refractive index of 4tt or more;
It is characterized by:

Effects According to the present invention, by using high-purity diethylbenzene, polymerization is easier than when conventional commercially available divinylbenzene is used, and the surface of the obtained lens does not become cloudy, and weather resistance is improved. It has now become possible to produce a copolymer for lenses that can be easily treated and dyed uniformly. In addition, since it is made from divinylbenzene, which is a bifunctional monomer that is easily available, it has a high refractive index and excellent solvent resistance. Lenses were easily obtained.

The divinylbenzene content is 80 or more.

Furthermore, high-purity divinylbenzene with non-polymerizable impurities of λ weight or less can be obtained by precisely refining commonly used low-purity divinylbenzene of 40 weight or less, or divinylbenzene, which has been developed in recent years, can be obtained by precision purification. It can also be obtained by a Grignard reaction between benzene and vinyl chloride. Divinylbenzene has three types of isomers: ortho, nosila, and meta, and in the present invention, these isomers may be used alone or as a mixture, and the divinylbenzene content is 91 or more, preferably rt weight or more, That's fine.

Generally, commercially available divinylbenzene contains ethylstyrene, diethylbenzene, naphthalene, etc. in addition to divinylbenzene. Of these, ethylstyrene has ortho,
Para and meta isomers exist. These do not have a crosslinking effect, but since they have polymerizable functional groups, they are incorporated into the polymer chain during polymerization, so they are eluted from the formed polymer or lens over time. It never comes. However, since non-polymerizable impurities such as diethylbenzene and naphthalene do not polymerize, they are eluted onto the lens surface over time and have adverse effects such as the aforementioned clouding of the lens. In the present invention, high purity divinylbenzene, divinylbenzene content is 80% by weight or more, caddiethylbenzene,
The content of non-polymerizable impurities such as naphthalene is less than 50% by weight, preferably less than 5% by weight.

In the present invention, divinylbenzene is used as a copolymer component!
~♂0 weight is used. ! If it is less than the weight range, the divinylbenzene content will be too small and the crosslinking effect will be poor, making it impossible to impart solvent resistance to the lens. On the other hand, if the weight range exceeds 80, a hard lens with a high refractive index can be obtained, but the strength will be relatively low. Preferably,
r~70 fold f14 is often used.

Comonomer (II) From the viewpoint of the strength of the copolymer produced, the upper limit of the content of divinylbenzene as a copolymer component should be 80% by weight. Niri! It is composed of radically polymerizable monomers that give a polymer having a weight layer refractive index of i, rs or more.

Examples of monomers having a refractive index of I, 11 or higher and capable of radical polymerization include (11 aromatic vinyl compounds such as styrene, α-methylstyrene, vinylnaphthalene, vinylcarbazole, +2) p- Nuclear halogen-substituted aromatic vinyl compounds such as chlorostyrene and p-bromostyrene, (3) aliphatic (mer)acrylates such as methyl methacrylate, butyl acrylate, isopropyl methacrylate, and diethylene glycol dimethacrylate, (41 methyl = α-chloro) Acrylate, butyl =
α-bromoacrylate, λ, 3-dipromob a pill=
Aromatic (meth)acrylates such as methacryloxyethoxybenzene, (meth)acryloxypolyethoxybenzene, (meth)acryloxypolypropoxybenzene,
(61 diethylene glycol bisallyl carbonate,
Examples include various allyl compounds such as diallyl phthalate, triallyl isocyanurate, allyl 7namate, allyl methacrylate, diallylated bisphenol A, allylruco, ψ, and A-1J bromobenzene.

Among these monomers, it is particularly dyeable and has a high refractive index.

It is desirable to use a monomer represented by the linear formula as it can impart low dispersibility.

(In the formula, R is hydrogen or an alkyl group of 01 to 02, X excludes fluorine) ・Rogen atom, p represents the number of ・Rogen substitutions / -j, and n is selected from θ to μ (Integer. When multiple X and R exist, they may be the same or different.) Chlorine, bromine, and iodine are common halogen atoms (X), but the high refractive index of the resulting copolymer From the viewpoint of stability over time, chlorine and bromine are more preferably used. The value of i has an important meaning on lens characteristics,
When this value is 5 or more, the surface hardness of the resulting lens tends to be poor and the refractive index tends to decrease. Therefore, in the present invention, an integer selected such that O-≠ is used. Of course, a mixture of various n may be used. The value of p has the greatest effect on the refractive index. By changing this value from l to 3,
It is possible to design a lens with a refractive index that suits the purpose.

Examples of such monomers include U and Hiromu.

6-Dolipromophenyl (meth), acrinaut, p-
Chlorphenyl(meth)acrylJl/-),/-(meth)acryloxyethoxydibromobenzene.

/-(meth)acryloxyethoxy-2,≠, t-tribromobenzene, /-(meth)acryloxyjethoxy-x, <c, 4-)I77"lombenzene, /-(meth)acryloxyethoxy- Hiro-Brombenzene, /-(
Examples include meth)acryloxyethoxyco, <c,4-)lichlorobenzene, /-(meth)acryloxyethoxypentabromobenzene, and mixtures thereof. As used herein, "(meth)acryloxy" and "(
The term "meth)acrylate" includes both groups and structures derived from acrylic acid and methacrylic acid.

In the present invention, these monomers are merely examples.

It is not limited to these. Moreover, these monomers (II) may be ls or a mixture, and high purity divinylbenzene (1), r-to weight ratio! It has been mentioned above that a weight width of ~J is used.

The copolymer produced by Akira Mizumoto is a high-purity divinylbenzene (I
) and comonomer (II) are subjected to polymerization conditions. Here, "mainly composed" means monomer (I) and (
II), in particular, a small amount of a copolymerizable third comonomer may be copolymerized as long as it does not unduly impede the effects inherent to the present invention that are primarily based on the use of monomer (I). means. Such a third comonomer is comonomer (II)
In contrast, there are no restrictions on the refractive index of the resulting polymer, and selection of one such monomer will be easy for those skilled in the art.

Polymerization Polymerization of the monomer mixture as described above proceeds using a conventional radical polymerization initiator. The polymerization method is also the one commonly used for normal radical polymerization! Get 7. However, since the resulting copolymer uses divinylbenzene, it is cross-linked and involves melting or dissolution, making it practically impossible to process the copolymer. Generally preferred.

Cast polymerization is a well-known technique. As the cast polymerization container, plate-shaped, lens-shaped, cylindrical, prismatic, conical, spherical, or other molds or molds designed according to the purpose are used. The material may be any suitable material such as inorganic glass, plastic, or metal. Polymerization is carried out by optionally heating a mixture of monomers and a polymerization initiator placed in such a container.

The polymerization can also be carried out in such a manner that a prepolymer or syrup obtained by carrying out a certain degree of polymerization in a separate container is charged into a polymerization container to complete the polymerization.

The required monomers and polymerization initiator may be mixed in their entire amounts at once, or may be mixed in stages. Also.

This mixture can be used depending on the intended use of the resulting copolymer.
It may also contain antistatic agents, colorants, fillers, ultraviolet absorbers, heat stabilizers, antioxidants and other auxiliary materials.

Another specific example of the polymerization method of the present invention is a method in which a mixture of required monomers and a polymerization initiator or a prepolymer is suspended in water to carry out polymerization, that is, suspension polymerization. This method is suitable for obtaining spherical lenses of various particle sizes. The suspension polymerization method is also a well-known technique, and the present invention may be appropriately carried out according to well-known knowledge.

The obtained copolymer is heated to complete any incomplete polymerization or to increase its hardness, or annealed to remove the strain incorporated by cast polymerization. Needless to say, it is possible to perform post-processing.

Lens The lens according to the present invention is essentially the same as a conventional synthetic resin lens, except for the following five points, when the lens material is the crosslinked copolymer of the present invention. Therefore, the present copolymer can be directly obtained as a lens by casting polymerization, or it can be cut out from a plate or other material.

If surface polishing, antistatic treatment, and other post-treatments are performed as necessary, a lens having various properties inherent to the copolymer of the present invention can be obtained. Furthermore, in order to increase the surface hardness, it is of course possible to form a coating film with an organic or inorganic hard coating agent by spray coating, dipping, etc. By multi-coating an inorganic material by surface vapor deposition or the like, it is also possible to reduce the surface gloss reflectance or increase the surface hardness.

Experimental Examples / Hiromu Kazuhiro, 6-dolipromophenyl methacrylate 7Jj
Ifik part O and 25 parts by weight of high-purity meta-divinyl buff 9F are mixed, and lauroyl peroxide/! A cast polymerization was carried out in a glass mold.

The purity of high-purity metadivinylbenzene was analyzed using a gas chromatograph. The resulting chart is the same as shown in FIG. 4 C-Shunko-As a result, this meta-divinylbenzene is meta-divinylbenzene 9F22. Meta and badge ethylbenzene as impurities 0.0
'16 to 4tTIL1, and ethylstyrene/, rj
It was found that it contains l#fp. 1 Analysis conditions are as follows.

Gas chromatograph device: Hitachi 463-30 type column packing material! 8DC! -60, 80wt%DIaaol
1d (Silicon system) Column length, diameter = λM X j mmφ column temperature K:
/≠o℃ Carrier gas: H2JO liter/min Detector:
TCD polymerization rate is so℃/hour, 60℃/i'i hour, I
The temperature was rO°C/2 hours and 80°C/80 hours. .

The obtained lens was colorless and transparent and had a beautiful luster. The refractive index and Abbe number of this lens are as follows, and this lens has an extremely high refractive index.

Refractive index ``n, /, 6Jr Atsube number ν = λr, Riko's lens is odorless, completely insoluble in solvents such as acetone and toluene, and the crosslinking effect is also found to be sufficiently large. In a vacuum dryer at 30°C/mmHg
When the evaluation time was maintained at a vacuum level of 1, the mold breakage decreased by θ, 02
It can be seen that the content of impurities and unreacted additives is extremely low, with the weight being less than 1.5 mm.This lens was made by conventional vapor deposition.

It was possible to apply a multilayer coating such as MgFz. .

Comparative example/! , 4c, j-tribromophenyl methacrylate (parts by weight) and commercially available divinylbenzea (i parts) were mixed, and cast polymerization was carried out in the same manner as in Example.

The chart of pure divinylbenzene on the market was analyzed using Gas Chromadogua 17, as shown in FIG.

As a result, this commercially available divinylbenzene contained 57 xi% para- and meta-divinylbenzene, ethylstyrene j7.
t ) l il %, diethylbenzene≠, 2% by weight and naphthalene 0.722λ/%.

The copolymer lens obtained by polymerization with a concentration of 4% had a strong odor due to remaining impurities. Refractive index is nr12
0 = /, 6λ/, Atsbe number = λ, 4! It can be seen that the crosslinking effect is poorer than that of Example. In addition, the lens surface becomes sticky due to the elution of impurities.
It was easy for dirt to adhere to it. This lens was vacuum dried under the same conditions as in Example. Lens weight reduction is 0.1
It can be seen that there is a problem as a lens because there is a lot of unreacted 2 and impurities remaining. Furthermore, when this lens was coated with a multilayer coating of various inorganic substances by vapor deposition, a transparent coating was not obtained, but the coating layer easily peeled off from the surface.

Example λ Acryloxyjetoxy-λ, 44. J-tribromobenzene 7! High purity metadivinylbenzene used in Example 1 and the heavy moiety 2! ; TL Pro was mixed, 1 part by weight of initiator lauroyl peroxide was added thereto, and cast polymerization was performed in a glass mold.

The obtained lens had good transparency and a high refractive index having the following optical properties.

Refractive index "n" = /, j 07 Atpe number ν = J/, t This lens was completely insoluble in organic solvents such as acetone and benzene, and had an excellent structural effect. The weight loss of this lens was measured in a vacuum dryer at 5° C. according to Example 1, and it was found to be 0.01% by weight or less. This lens was placed in an aqueous solution of ``Sumikalon Blue E-F'BLJ (manufactured by Sumitomo Chemical G Ceramics) /, !g/water/liter at rO℃.
When treated for 9 minutes, bright blue staining was observed, indicating that the staining properties were rich.

Comparative Example 7j parts by weight of λ acryloxyjethoxy-λ,g,4-tribromobenzene and 5 parts by weight of the commercially available divinylbenzene used in Comparative Example were mixed, and 1 part by weight of lauroyl peroxide was added thereto. , Cast polymerization was carried out in the same manner as in Example 1. The obtained lens had a strong odor of residual impurities, as in Comparative Example, and elution of the residual impurities was observed on the surface. The refractive index and Atsube number were as follows.

Refractive index n, 20 == /, 7 Atpe number ν; 3λ, 01 Compared with Example 2, it can be seen that the polymerizable crosslinking effect is insufficient. Next, the weight loss was measured at 5°C in a dryer according to Example 1), and the result showed that it was approximately 20%.Also, a similar lens was prototyped and used in Example 1. When a staining test was conducted in accordance with the above, it was found that the color was poor and there were some undyed areas, indicating that 98 effects of residual impurities had appeared.

Example Ju, Hiroshi, J-) 30 parts by weight of dibromophenyl methacrylate, methacryloxydiethoxylate 2. Hiroshi.

Cast polymerization was carried out in a glass mold under the same conditions as in Example 1 using 1 IoIL parts of 6-tripromobenzene and 30 parts of high purity para-9 vinylbenzene.

A gas chromatography chart of high purity haladivinylbenzene is shown in FIG. This diagram shows that this badged vinylbenzene is paradivinylbenzene 2g'f
Xk'', 1.6% by weight of parachloromethane, parahydroxystyrene o, weight t'16 fpr: It can be seen that it contains tr.

The optical properties of the copolymer lens obtained by M Society were as shown below. ”n20=/, t-20, shi:λri,,ro In this way, this lens was useful and had a high refractive index. When I measured the decrease in void, it was about 0.0
/%Met.

Example Hiroacryloxyethoxy-4,≠,6-dripromohenzene 27 parts by weight, methacryloxyethoxy! ,,4!
, 4-tribromobenzene JjfL amount part, S f v y
30 heavy 74 parts O and high purity divinyl pair 'c!
7/! Cast polymerization of the zMjtk part was carried out according to Example 1 of the actual hTli. The gas chromatograph chart of this high #g anti-divinylbenzene was as shown in Figure 4L.

As shown in this figure, this divinylbenzene contains n% by weight of meta and haladivinylbenzene, and 1% by weight of ethylmethylbenzene. ．． double f
It contained other impurities such as θ, Ir, and other impurities. The lens obtained by polymerization was colorless and transparent, and had almost no odor from impurities. The optical properties of this lens were as shown below.

nn /, A (77 &'=J/, J From this data, it can be seen that this lens has a high useful high refractive index. Fruit 1: According to Example I/, the ■ mass reduction in a vacuum dryer When measured, the weight loss was o, otr#
;:H% or less, which was a small amount, and was found to be useful as a lens.

For example, acryloxyethoxy-λ, Hiroshi, 6-dribromobenzene-Zj M 1% (S, methacryloxyethoxy-2, Hiroshi, 6-dribromobenzene Hiroshi' M 'At
Example 114. The +++ purity metadivinylbenzene/j -4 parts used in Example 1 and 15 parts by weight of α-methylstyrene, and 5 parts of lauroyl peroxide as a polymerization initiator were polymerized. , Example 1
Cast polymerization was carried out in a glass mold according to . A good copolymer lens was obtained. Its optical properties were as shown below.

Refractive index "In": /, 4/J.

Atsube number ν=JOJ This lens did not dissolve in acetone, toluene, etc. and exhibited good chemical resistance. (under the same conditions as Example 1)! ! As a result of air drying, the weight loss of this lens was 0.0/
It's below the J' weight section.

Example 6 2,≠,j-) Libromophenyl methacrylate loading part, methacryloxyjethoxy-,2,tl.

A-) IJ 7” Lomobenzene JJ N Okibe, α
-)l f A/ , I.

A lens was prototyped according to Example 1 using 20 parts by weight of tyrene and 75 parts by weight of the high-purity divinylbenzene used in Example Hiro. The optical properties of the obtained lens were as shown below.

Refractive index nn −/, A / A Atsbe number ν = JO,j Further, as a result of vacuum drying under the same conditions as in Example 1, the weight loss of this lens was less than o, or weight %.

■

[Brief explanation of the drawing]

1st. ! FIG. 1 is a reproduction of a chart showing the gas chromatograph measurement results of high-purity divinylbenzene used in the present invention. FIG. 2 is a reproduction of a chart showing the results of gas chromatography measurements of commercially available divinylbenzene.

Claims (1)

[Scope of Claims] 1. High purity divinylbenzene (I) 5 to 8 having a purity of 80% by weight or more and containing non-polymerizable impurities of 2% by weight or less
0% by weight and 95 to 20% by weight of a radically polymerizable monomer (II) giving a polymer with a refractive index of 1.55 or more is subjected to polymerization conditions. A method for producing a copolymer for high refractive index lenses. 2. Production of a copolymer according to claim 1, wherein the radically polymerizable monomer (II) that provides a polymer with a refractive index of 1.55 or more is a monomer represented by the following formula: Law. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R is hydrogen or an alkyl group of C_1 to C_2,
X is a halogen atom excluding fluorine, p represents the number of halogen substitutions, and is an integer selected from 1 to 5, n is 0
An integer selected from ~4 is shown, respectively. When a plurality of X and R are present, they may be the same or different. )