JPS61200501A - Production of plastic lens - Google Patents

Abstract

PURPOSE:To improve a transparency and a mechanical property of the titled lens by defaming a reactive mixture or its intermediate product capable of forming an unsatd. urethane type compd. which is added a specific polymerization initiator thereto under a specific condition followed by pouring it into a mold without generating any foaming and an undesired curing during molding and curing. CONSTITUTION:In the preparation of the titled lens in which the reactive mixture capable of forming the unsatd. urethane type compd. or the intermediate product obtd. from said mixture is poured into the mold and then cured, said reactive mixture or its intermediate product is deformed in the presence of the polymerization initiator having >=120 deg.C b.p. under <=100mmHg a pressure followed by pouring it into the mold. The reaction mixture or its intermediate product comprises preferably an alkylene oxide adduct of tetrabrombisphenol a hydroxyalkyl (metha)acrylate and a non-yellowing polyisocyanate compd. contg. an aromatic ring as an essential component. By treating as mentioned above, the foaming during molding and curing and the production of substandard products are prevented, thereby obtaining the plastic lens having a good mechanical property, a good solvent resistance, a good transparency and no change of a color.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing a plastic lens suitable for an optical element such as a lens for spectacles.

[Prior Art] Diethylene glyco-bisallyl carbonate polymers are widely used as optical resins suitable for optical elements such as eyeglass lenses. Although this polymer has various excellent properties as an optical resin, its low refractive index is a drawback. Various studies have been conducted to develop optical resins with a high refractive index, and in particular, polymers of addition polymerizable unsaturated compounds such as (meth)acrylates having a polyhalogenated aromatic nucleus have a relatively high refractive index. It is known that the rate is about to be achieved.

However, this polymer has problems in that it does not have sufficient mechanical properties such as impact resistance and is easily discolored. Addition polymers of unsaturated urethane compounds have been proposed as optical resins that solve the problems of mechanical properties and discoloration.

This plastic lens has a refractive index higher than that of the diethylene glycol bisallyl carbonate polymer and also has sufficient mechanical properties.

In the following explanation, an unsaturated urethane compound refers to a mono- or polyhydroxy compound having an addition-polymerizable unsaturated group, or a hydroxy compound and a mono- or polyhydroxy compound not having an addition-polymerizable unsaturated group, and a hydroxy group. The unsaturated hydroxy compound is a reaction product obtained by reacting an approximately equivalent amount (approximately 0.7 to 3 equivalents) of a non-yellowing polyisocyanate compound. ) are preferred, specifically hydroxyalkyl (meth)acrylates, epoxy (meth)acrylates containing hydroxy groups, polyhydric alcohols and (meth)acrylates, and polyhydric alcohols and (meth)acrylates.
Examples include partial esters of acrylic acid, and hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate are particularly preferred. As the mono- or polyhydroxy compound, a polyol having an aromatic nucleus, particularly a polyol having an aromatic nucleus to which a bromine atom is bonded, is preferable. For example, there are alkylene oxide adducts of polybrominated bisphenols. In particular, polyols obtained by adding 2 moles or more, especially 2 to 6 moles of ethylene oxide and/or propylene oxide to polybrominated bisphenol A are preferred. Particularly preferred unsaturated urethane compounds include the above-mentioned hydroxyalkyl (meth) It is a reaction product of acrylate, an alkylene oxide adduct of polybrominated bisphenol A, and a non-yellowing polyisocyanate compound having an aromatic nucleus (for example, xylylene diisocyanate).

When manufacturing plastic lenses from unsaturated urethane compounds by casting and curing, it is actually not preferable to completely manufacture the unsaturated urethane compound before casting. Saturated urethane compounds have high viscosity, making defoaming treatment described below difficult. Therefore,
A mixture of raw materials capable of forming the unsaturated urethane compound (hereinafter referred to as Zimmer's solution) or a mixture obtained by reacting a portion of the raw materials in advance and adding the remaining raw materials (hereinafter referred to as prepolymer solution) are cast. . In the curing reaction (urethanization reaction and addition polymerization reaction) after casting, the urethanization reaction (reaction between hydroxyl groups and isocyanate groups) usually precedes the urethanization reaction (reaction between hydroxyl groups and isocyanate groups), but the urethanization reaction and addition polymerization reaction do not occur completely separately. It is thought that there are some parts where both occur at the same time. It is thought that the reaction (particularly the urethanization reaction) gradually proceeds in the 7-mer solution and the prepolymer solution after they are produced, and that the reaction also proceeds to some extent in the defoaming treatment described below. However, as described above, it is not preferable that all the hydroxy groups and isocyanate groups react before casting to form an unsaturated urethane compound containing no unreacted substances. Therefore, it is considered that the 7-mer solution or prepolymer solution at the time of casting is a mixture containing a large amount of unreacted substances and a certain amount of reaction products (hereinafter referred to as reaction intermediates).

[Problems to be Solved by the Invention] The method for manufacturing the plastic lens described above involves adding a monomer or prepolymer solution containing a polymerization initiator to 11! After passing through and defoaming, it is poured into a lens mold and polymerized by heating. This method is
Diethylene glycol bisallyl carbonate polymer is a known method for producing plastic lenses, but the handling of unsaturated urethane compounds differs from that of diethylene glycol bisallyl carbonate in the following points.

In other words, since unsaturated urethane compounds contain compounds containing incyanate groups in the monomer or prepolymer liquid, the incyanate groups react with moisture in the liquid and in the air to generate carbon dioxide, which is then released into the polymer. It enters as air bubbles. To eliminate this problem, it is necessary to completely remove water in the system by defoaming the monomer liquid or prepolymer liquid for a long time under high vacuum. However, in such a process, low-boiling components tend to be distilled off, and especially when a low-boiling point polymerization initiator is used, the initiator is easily distilled off, so that the addition polymerization reaction is not completed. There is a problem that the mechanical properties and solvent resistance of the obtained plastic lens tend to deteriorate.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems. Namely, the present invention has been made to solve the above-mentioned problems. In a method of manufacturing a plastic lens by casting a reaction intermediate having a cyanate group and performing a curing reaction, the reactive mixture or the reaction intermediate is heated at 100°C in the presence of a polymerization initiator having a boiling point of 120°C or higher. A method for producing a plastic lens, characterized by performing a degassing treatment at the following temperature and a pressure of 100 ml (g) or less, and then casting.

The polymerization initiator in unreleased 111 has a boiling point of 120
One or more organic peroxides selected from the group consisting of (a) peroxide-based compounds and (b) azobis-based compounds having a temperature of at least 0.degree. C. are used.

(i) As a polymerization initiator, (c) hydroperoxide, (d) dialkyl peroxide, (e) peroxyketal, (h) peroxyester, (g) diacyl peroxide, (th) peroxycarbonate. One or more selected from the group consisting of:

As the hydroperoxide (c), cumene hydroperoxide, 2,5-dimethylhexane-2
,5-dihydroperoxide.

, 3,3-tetramethylbutyl hydroperoxide, p-methane hydroperoxide, and diisopropylbenzene hydroperoxide, or one or more of them are suitable.

The (d) dialkyl peroxide is 2.5
-dimethyl-2,5-di(tert-butylperoxy)hexyne-3,2,5-dimethyl-2,5-di(1-
butylperoxy)hexane, α,α′-bis(ter)
One or more selected from the group consisting of t-butylperoxy (1-isopropyl)benzene, dicumyl peroxide, and tart-butylcumyl peroxide are suitable.

As the (e) peroxyketal, 1-bis(
tert-butylperoxy) 3.3.5-trimethylcyclohexane, 1-bis(t-butylperoxy)cyclohexane, 2.2-bis(tert-butylperoxy)octane, n-butyl 4.4-bis (ter
Suitable are one or more selected from the group consisting of t-butylperoxy)valeret), 2,2-bis(tert-butylperoxy)butane.

As the peroxy ester, tert-hexylperoxyneohexanoate, tert-butylperoxyneohexanoate, tert-hexylperoxypivalate.

tart-hexyl peroxyneodecanoate.

cumyl peroxyoctoate, tert-butylperoxyisopropyl carbonate), tert-butylperoxymaleic acid, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane.

Di-tert-butyl cibaroxyisophthalate.

tert-butyl peroxybenzoate, tert
-butylperoxylaure F* tert-butylperoxy 3.5.5-trimethylhexanoate.

tert-butyl peroxy 2-ethylhexanoate, cumyl peroxy neodecanoate.

tert-butyl peroxyneodecanoate.

tert-butyl peroxybivalate, tert-
one or two selected from the group consisting of
More than just seeds are appropriate.

The (t) diacyl peroxides include acetyl peroxide, imbutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3.5.5-trimethylhexanoyl peroxide, and succinic acid peroxide. .

One or more selected from the group consisting of benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, and layer-toluoyl peroxide are suitable.

As the peroxycarbonate (H), G2-
Ethylhexyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di-myristyl peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate, di-methoxyisopropyl peroxydicarbonate, di(3-methyl-3- methoxybutyl) peroxydicarbonate.

One or more members selected from the group consisting of tert-butyl peroxyallyl carbonate are suitable.

As the (b)azobis compound, for example, 2.2'
-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-valeronitrile), (1-phenylethyl)azodiphenylmethane, 2,2'-7zobis Isobutyronitrile, dimethyl 2,2'-7zobisisobutyrate,
2.2'-azobis(2-methyl-butyronitrile)
,, Beazobis(1-cyclo-hexanecarbonitrile).

2-(Carbamoylazo)-isobutyronitrile.

Examples include 2'-azobis(2,4,4-trimethyl-pentane) and 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile.

In the present invention, among the above-mentioned polymerization initiators, the above-mentioned (c) hydroperoxide, (d) dialkyl peroxide, (e) peroxyketal, (t) diacyl peroxide, and (t) azobis-based compound are preferred, but especially (
(d) Dialkyl peroxide, (e) peroxyketal, (e) diacyl peroxide, and (i) azobis-based compounds are preferred.

In the present invention, particularly preferable (d)dialkyl peroxides include dicumyl peroxide, te
rt-butylcumyl peroxide is used as the (e)peroxyketal, n-butyl-4,4-bis(t
ert-butylperoxy)valerate, 1-bis(tert-butylperoxy)3.3.5-trimethylcyclohexane is the diacyl peroxide described above, and benzoyl peroxide is the diacyl peroxide described above (a).
Examples of azobis-based compounds include 2.2'-7zobisisobutyronitrile and 2.2'-azobis(2,4,4-)limethyl-pentane).

As mentioned above, as raw materials for unsaturated urethane compounds, unsaturated hydroxy compounds and unmodified polyisocyanate compounds are essential raw materials, but mono- or polyhydroxy compounds having no unsaturated groups (hereinafter referred to as saturated hydroxy compounds) are essential raw materials for unsaturated urethane compounds. (referred to as a compound) is preferably used in combination.

As an unsaturated hydroxy compound, (meth)acrylic acid-
Alkylene oxide adducts, e.g.
1111r Cast Small 〒 17 So + Wang, ~ No V starvation [8 is a hydroxyalkyl (meth)acrylate consisting of a propylene oxide adduct, a partial ester of a polyhydric alcohol and (meth)acrylic acid, such as a dihydric alcohol. Monoester, mono- or diester of trihydric alcohol, 4
Epoxy (meth)acrylates containing mono-, di-, or tri-esters of alcohols or hydroxyl, such as phenyl glycidyl ether, diglycidyl ethers of bisphenols and their oligomers (a type of epoxy resin), and other epoxy group-containing compounds There are compounds obtained by reacting (meth)acrylic acid with (meth)acrylic acid, etc.If these unsaturated hydroxy compounds do not have an aromatic nucleus, the aromatic nucleus-containing saturated hydroxy compound described below is used to increase the refractive index of the plastic lens. It is necessary to use them together. When the unsaturated hydroxy compound has an aromatic nucleus, it is not necessary to use a saturated hydroxy compound, but a small amount may be used, and when it is a saturated hydroxy compound containing an aromatic nucleus, a relatively large amount may be used. You can. The aromatic nucleus of the aromatic nucleus-containing unsaturated hydroxy compound may contain a halogen such as chlorine or bromine. A particularly preferred unsaturated hydroxy compound is hydroxyalkyl (meth) having a hydroxyalkyl group having 2 to 4 carbon atoms.
Acrylates are particularly suitable, particularly 2-hy10xyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate.

As the saturated hydroxy compound, a polyhydroxy compound having an aromatic nucleus is preferable, but a small amount of other saturated hydroxy compound may also be used in combination.As the aromatic nucleus-containing saturated polyhydroxy compound, polyhydric phenols, especially bisphenols, Preferably, the polyhydric phenols have one or more chlorine or bromine, particularly preferably polybrominated bisphenols, such as tetrabromobisphenol A.
, tetrabromobisphenol S, tetrabromobisphenol F, etc. The alkylene oxide is preferably an alkylene oxide having 2 to 4 carbon atoms, particularly ethylene oxide and propylene oxide. For addition of alkylene oxide to polyhydric phenols, it is appropriate to use one or more alkylene oxide molecules, particularly about 1 to 6 molecules, per one phenolic hydroxyl group. For polybrominated bisphenols, it is preferable that about 2 to 6 alkylene oxide molecules are added to the polybrominated bisphenol molecule. In the present invention, a particularly preferred saturated hydroxy compound is tetrabromobisphenol A ethylene oxide. and/or a propylene oxide adduct (the amount added is 2 to 6 molecules of the latter per 1 molecule of the former).

The ratio of the unsaturated hydroxy compound and the saturated hydroxy compound to be used is preferably a combination of 20 to 10% by weight of the former and 0 to 80% by weight of the latter, particularly 20 to 70% by weight of the former.
In the case of a compound in which the former has an aromatic nucleus and the latter has an aromatic nucleus, a combination of 30 to 130% by weight of the former and 40 to 70% by weight of the latter is particularly preferable.

Amorphous modified polyisocyanates include polyisocyanate compounds that do not have an aromatic nucleus and polyisocyanate compounds that have an aromatic nucleus (however, the isocyanate group is not directly bonded to the aromatic nucleus). The latter is preferred; examples of the former include hexamethylene diisocyanate, methylenebisrecyclohexyl isocyanate, inphorone diisocyanate, etc., and examples of the latter include xylylene diisocyanate, α, α.

α′, α′, -Tetramethylxylylene diisocyanate, α, α, α′, α′, α″.

α″-hexamethyl mesitylene triisocyanate, etc. These polyisocyanates may be modified products, such as prepolymer-type modified products, carbodiimide modified products, Beauleft modified products, urea modified products, allophanate resins, etc. ka)' ht, ask ka se gil iso,
- As mentioned above, the appropriate amount of the 77-cell compound used is about 0.7 to 3 equivalents, especially 0.8 to 3 equivalents, based on the total amount of hydroxyl compounds. , 2 equivalents are preferred.

A compound that is non-reactive with respect to a hydroxyl group or incyanate group or a small amount of a reactive compound can be blended into the reactive mixture consisting of a mixture of the raw materials listed in L. Examples of non-reactive compounds include non-reactive addition polymerizable compounds. Although the use of this addition polymerizable compound is not essential, it can be copolymerized with an unsaturated urethane compound for the purpose of improving physical properties. Other optional ingredients include stabilizers, colorants, polymerization inhibitors, fillers (that do not make the plastic lens opaque), and urethanization catalysts. Stabilizers include ultraviolet absorbers, antioxidants, and light stabilizers. If these optional raw materials are compounds with a low boiling point, it is difficult to blend them before the defoaming treatment, and in that case, it is desirable to blend them after the defoaming treatment.

A reactive mixture may be a mixture (monomer liquid) obtained by mixing all the raw materials in a recycled manner, or a mixture (prepolymer liquid) obtained by reacting some parts in advance and mixing other parts with it. Good too. In particular, it is preferable to use a prepolymer solution obtained by mixing the remaining polyisocyanate compound with a prepolymer obtained by reacting all hydroxy compounds with a small amount of polyisocyanate compound in advance. This is a preferred method when using an alkylene oxide adduct of bisphenols. This is because in a mixture of all hydroxy compounds containing this compound, there is a problem that this compound tends to precipitate at room temperature, and this problem of precipitation can be solved by reacting a small amount of polyisocyanate compound in advance. be. The amount of the polyisocyanate compound reacted in advance is preferably 5 to 40% by weight based on the total polyisocyanate compound. The polymerization initiator may be added in advance to one component of the raw materials, but if heat treatment is performed before the mixture is manufactured, there is a risk that the polymerization initiator will decompose. A polymerization initiator is added to the polymer solution after it is produced.The solution after the addition of the polymerization initiator is preferably subjected to a cancer sieve to remove insoluble matter and impurities.

The amount of polymerization initiator used varies depending on the type of polymerization initiator, but it is usually 0 weight jt 1% or less, based on the total raw materials.
In particular, it is 0.5% by weight or less, and 0.5% by weight or less. O1 hair ¥% or more is preferable.

The defoaming treatment is carried out at a temperature of 100° C. or less and a pressure of lohmHg or less. Preferably, it is carried out at a temperature of 60° C. or less and a pressure of 20 mmHg or less.

It is preferable that both temperature and pressure are low, but if the temperature is too low, it will take time to degas, and if the pressure is too low, there is a risk that the polymerization initiator will be distilled off. Usually, defoaming treatment is carried out at a temperature of 0° C. or higher and a pressure of 0.1 m) or higher.

Addition polymerization is preferably carried out by thermal polymerization, but depending on the case, it can be carried out by ultraviolet rays, electron beams, or other energy rays. The addition polymerization temperature depends on the type of addition polymerization initiator, but at the initial stage of addition polymerization, a temperature of about room temperature to about 80°C is appropriate.In the latter stage of addition polymerization, higher temperatures can be used, but the upper limit is about 150°C. preferable.

Molding of optical resin is performed by a casting method. That is, the defoamed 7mer liquid or prepolymer liquid (often a reaction intermediate) is injected into the mold, and after the curing reaction is completed in the mold, the molded product is removed from the mold. It's a method. The molded product is preferably a colorless transparent or colored transparent plastic lens used for eyeglass lenses.The mold for lens molding is usually two glass or plastic molds; It is not limited. A mold release agent may be applied to the inner surface of the mold, if desired.

The most suitable plastic lens manufactured according to the present invention is a lens for spectacles, but it is not limited thereto.

[Example] Example 1 In a reactor equipped with a stirring blade and a cooling tube, 368 parts (parts by weight: the same shall apply hereinafter) of 2 mole adduct of tetrabromobisphenol A with ethyleneoxy and 303 parts of hydroxyethyl methacrylate were placed in a reactor equipped with a stirring blade and a cooling tube. A homogeneous solution was obtained by heating to 75° C. for 1 hour under atmosphere. After this solution was allowed to cool to 45°C, 49.4 parts of xylylene diisocyanate (corresponding to 15% of the equivalent weight) was added, stirred thoroughly, and then cooled to room temperature to obtain a colorless and transparent liquid. 279.8 parts of xylylene diisocyanate was mixed with this to produce a prepolymer liquid.

Add and dissolve 0.2 parts of dicumyl peroxide to 100 parts of the prepolymer solution, filter through a membrane filter with a pore size of 1 gg+, and then reduce the pressure at approximately 30°C and a vacuum pressure of 1 mmHg for 2 hours. Defoaming was performed.

The liquid thus obtained was poured into a mold made of two spherical glass molds and soft polypropylene, and heated at 40°C for 2 hours while linearly increasing the temperature from 40°C to 120°C.
After heating at 120° C. for 8 hours and 40 hours, a strong, colorless and transparent lens was obtained. For this lens sample,
A solvent resistance test and a falling ball test were conducted.

In the solvent resistance test, the weight increase rate (coulometric %) was measured after immersion in dimethylformamide at 80° C. for 2 hours.

The falling ball test was conducted in accordance with FDA standards (measured at a lens center thickness of 5 m+s and a height of 127 cm).

The results are shown in Table 1.

Example 2 For 100 parts of the prepolymer solution of Example 1, tert-
0.2 part of butyl-cumyl-peroxide was stirred and mixed, and defoaming was performed under the same conditions as in Example 1 to obtain a colorless transparent liquid.

Table 1 shows the characteristics of a lens obtained using this solution in the same manner as in Example 1.

Example 3 To 100 parts of the prepolymer liquid of Example 1, 0.2 parts of 1-bis(tert-butylperoxy) 3.3.5- )limethylcyclohexane was stirred and mixed.
A colorless transparent liquid was obtained by degassing under the same conditions as above.

Table 1 shows the characteristics of a lens obtained using this solution in the same manner as in Example 1.

Table 1 Comparative Example 1 For 100 parts of the prepolymer solution of Example 1,
0.2 part of t-butyl peroxide (boiling point 110''C) was stirred and mixed and defoamed under the same conditions as in Example 1 to obtain a colorless transparent liquid.

Table 2 shows the characteristics of a lens obtained using this solution in the same manner as in Example 1.

Table 2 Comparative Example 2 Di-isopropyl-peroxydicarbonate (boiling point 47°C haOO) was added to 100 parts of the prepolymer solution of Example 1.
mmHg) 0.2 were stirred and mixed and defoamed under the same conditions as in Example 1 to obtain a colorless transparent liquid.

The properties of a lens obtained using this solution in the same manner as in Example 1 are shown in Table 2 above.

[Effects of the Invention] The present invention has excellent effects such as significant improvement in mechanical properties such as impact resistance and #solvent properties of plastic lenses made of polymers of unsaturated urethane compounds. By making it possible to degas the space between 11'1 and 11'1, the effect of improving foaming during casting and curing and the occurrence of defective cured products is also recognized.

The plastic lens obtained in the present invention has excellent transparency and has extremely little risk of discoloration. In addition, it has excellent mechanical properties such as impact resistance, and is comparable to the diethylene glycol bisallyl carbonate polymer.

Claims (2)

[Claims] (1) In a method of producing a plastic lens by casting a reactive mixture capable of forming an unsaturated urethane compound or a reaction intermediate having unreacted isocyanate groups produced from the mixture and performing a curing reaction, the reactive mixture or the reaction intermediate at 120
1. A method for producing a plastic lens, which comprises performing a defoaming treatment at a temperature of 100° C. or lower and a pressure of 100 mmHg or lower in the presence of a polymerization initiator having a boiling point of 100° C. or higher, followed by casting. (2) A reactive mixture or a reaction thereof in which the reactive mixture or reaction intermediate contains as essential components an alkylene oxide adduct of tetrabromobisphenols, a hydroxyalkyl (meth)acrylate, and a non-yellowing aromatic nucleus-containing polyisocyanate compound A method according to claim 1, characterized in that it is an intermediate.