JPH04321664A - Production of monomer composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition excellent in impact resistance, having a high refractive index and useful for an optical resin, etc., by admixing an organic solvent containing a thioacrylic(thiomethacrylic) acid ester as a monomer with another copolymerizable monomer. CONSTITUTION:With an organic solvent (e.g. methylene chloride) containing a thioacrylic acid ester and/or a thiomethacrylic acid ester (e.g. methyl thioacrylate) as a monomer, another monomer (e.g. 2-hydroxyethyl methacrylate) copolymerizable therewith is admixed. As necessary, a polymerization inhibitor (hydroquinone) is added thereto. The organic solvent is then removed, thus obtaining the objective monomer composition. As the mixture ratio of the other monomer, the other monomer is used in an amount of 5-1000 pts.wt. in the case of a monofunctional monomer or 10-1000 pts.wt. in the case of a >=2 functional monomer based on 100 pts.wt thioacrylic(thiomethacrylic) acid ester.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a monomer composition comprising a thioacrylic acid ester and/or a thiomethacrylic acid ester and another monomer copolymerizable therewith.

0002

BACKGROUND OF THE INVENTION Thioacrylic acid esters and/or thiomethacrylic acid esters are often used in admixture with other monomers copolymerizable with them.

That is, this monomer composition is useful as an optical material, and is also used in paints, inks, adhesives, rubber vulcanizing agents, photosensitive resins, crosslinking agents, and the like. In particular, the resin obtained by polymerizing this composition has excellent impact resistance,
Since it has a high refractive index, it is suitably used in the field of optical materials as an organic glass, for example, as an optical lens such as a spectacle lens or an optical equipment lens.

By the way, this thioacrylic acid ester or thiomethacrylic acid ester is generally produced by dehydration condensation of thiol and acrylic acid or methacrylic acid in an organic solvent solution, or by combining thiol and acrylic acid chloride or methacrylic acid chloride. Synthesized by dehydrochlorination in the presence of a base. Therefore, the above-mentioned thioacrylic acid ester and/or thiomethacrylic acid ester can be obtained as an organic solvent solution. In order to produce the monomer composition, the solvent is removed from the organic solvent solution of the thioacrylic ester and/or thiomethacrylic ester obtained in this way to obtain the thioacrylic ester and/or thiomethacrylic ester. After isolation, it is a common method to mix these with a copolymerizable monomer.

[0005]

However, the thioacrylic acid ester and/or the thiomethacrylic acid ester are partially polymerized in the step of removing the organic solvent from the organic solvent solution, resulting in the formation of a polymer. Therefore, a polymerization inhibitor is usually added to the organic solvent solution before the organic solvent is removed, but a satisfactory effect in suppressing the formation of polymers has not been obtained. Resins obtained by polymerizing thioacrylic esters and/or thiomethacrylic esters containing the above polymers have various physical properties such as transparency and hardness that are significantly impaired due to the above polymers.

[0006] Against this background, it has been a major challenge to develop a method for producing the monomer compositions using simple operations without producing such polymers.

[0007]

[Means for Solving the Problems] The present inventors have made extensive research in order to solve the above problems. the result,
Before removing the organic solvent from an organic solvent solution containing thioacrylic acid ester and/or thiomethacrylic acid ester as a monomer, this monomer can be mixed with another monomer that can be copolymerized with the above monomer. They have discovered that the formation of polymers can be prevented, and have completed the present invention.

That is, in the present invention, after mixing other monomers copolymerizable with the above monomer into an organic solvent solution containing thioacrylic acid ester and/or thiomethacrylic acid ester as a monomer, A method for producing a monomer composition comprising the above-mentioned monomer and another monomer copolymerizable therewith, characterized in that the solvent is removed.

In the present invention, known compounds can be used as the thioacrylic ester and thiomethacrylic ester without any restriction. Among these, compounds represented by the following formulas (I) and (II) are preferably employed.

0010

[Chemical formula 1]

(However, R1 is a hydrogen atom or a methyl group, R2 and R3 are the same or different hydrogen atoms or alkyl groups, respectively, and R4 is a hydrogen atom,
It is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group, and m is an integer of 0 or more. )

0012

[Case 2]

[However, R1 and R1' are hydrogen atoms or methyl groups, and A is

[0014]

[Chemical 3]

[0015]

[C4]

[0016] or

[0017]

[C5]

(However, R2 and R3 are represented by the above formula (I)
is the same as , X is an oxygen atom or a sulfur atom, and n
1, n2 and n3 are integers greater than or equal to 0). ] In the above general formulas (I) and (II), R2 and R3 are not particularly limited as long as they are the same or different hydrogen atoms or alkyl groups, but from the viewpoint of the use of the polymer obtained by polymerization in optical materials. is preferably a hydrogen atom or a methyl group.

In the above general formula (I), R4 is a hydrogen atom,
A substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group. The above alkyl group is not particularly limited in its carbon number, but from the viewpoint of the viscosity of the thioacrylic acid ester and thiomethacrylic acid ester and the refractive index of the polymer obtained by polymerization, the carbon number of the alkyl group is 1 to 1. It is preferable that it is 5. For example, methyl group, ethyl group, n-
Propyl group, i-propyl group, n-butal group, sec
-butyl group, t-butyl group, n-pentyl group, etc. Further, the above aryl group is not particularly limited in its carbon number, but preferably has 6 to 10 carbon atoms for the same reason as above. Examples include phenyl group, tolyl group, xylyl group, naphthyl group, and the like. The number of carbon atoms in the aralkyl group is not particularly limited, but is preferably 7 to 10 for the same reason as above. Examples include benzyl group, phenethyl group, phenylpropyl group, and the like.

Substituents for the alkyl, aryl, and aralkyl groups represented by R4 are not particularly limited, and include halogen atoms, alkoxy groups, alkylthio groups, phenyl groups, phenylthio groups, and the like. Representative examples of these substituted alkyl groups, substituted aryl groups, and substituted aralkyl groups include, for example, halogenoaralkyl groups such as chlorophenylmethyl group, dibromophenylmethyl group, and tribromophenylmethyl group; chloromethyl group, bromomethyl group; , halogenoalkyl groups such as trichloromethyl group; halogenoaryl groups such as chloroenyl group, bromophenyl group, dichlorophenyl group, dibromophenyl group, tribromophenyl group; methylthiophenyl group, di(methylthio)phenyl group, phenylthiophenyl group, Examples include biphenyl group, methylthiophenylmethyl group, and di(methylthio)phenylmethyl group. In the present invention, R4 in general formula (I) may be selected depending on the use of the resulting resin, but in order to obtain a resin with a high refractive index and low dispersion, it is necessary to select a substituted or unsubstituted aralkyl group. It is preferable that there be.

In addition, m in the above general formulas (I) and (II), and n1, n2 and n3 in the general formula (II)
may be an integer greater than or equal to 0. Generally, if these values are made too large, the viscosity of the compounds represented by general formulas (I) and (II) will increase rapidly, making handling difficult, and the heat resistance of the resin obtained by polymerization will decrease. Problems arise, such as being left behind. Therefore, considering the refractive index, impact resistance, and heat resistance of the resulting resin, m, n1,
It is preferable that n2 and n3 are each selected in the range of 0 to 5, particularly m is selected in the range of 1 to 3, and n1, n2 and n3 are selected in the range of 0 to 2.

Examples of thioacrylic acid esters and/or thiomethacrylic acid esters preferably employed in the present invention include methyl thiomethacrylate, ethyl thiomethacrylate, phenyl thiomethacrylate, biphenyl thiomethacrylate, and naphthyl thiomethacrylate. , benzyl thiomethacrylate, chlorophenyl thiomethacrylate, tribromophenyl thiomethacrylate, methyl thioacrylate, phenyl thioacrylate, naphthyl thioacrylate, benzyl thioacrylate, benzylthioethylthiomethacrylate, benzylthioisopropylthiomethacrylate, Examples include ethanedithioldithiomethacrylate, isopropyldithioldithiomethacrylate, and phenyldithioldithiomethacrylate.

In the production method of the present invention, first, other monomers copolymerizable with this monomer are added to an organic solvent solution containing the above-mentioned thioacrylic acid ester and/or thiomethacrylic acid ester as a monomer. are mixed. As this organic solvent, known ones can be used without particular limitation, but examples of those that are preferably used include aliphatic or aromatic solvents such as benzene, toluene, xylene, hexane, heptane, and petroleum ether. Hydrocarbons or halogenated hydrocarbons such as chloroform, methylene chloride, and ethylene chloride; ethers such as diethyl ether and dioxane tetrahydrofuran; N,N-dialkylamides such as N,N-dimethylformamide; dimethyl sulfoxide, etc. Can be mentioned. More preferably, the above-mentioned halogenated hydrocarbons are used, which have a halogen group capable of inhibiting polymerization, have a low boiling point, and are easily removed.

In the present invention, the organic solvent solution containing thioacrylic acid ester and/or thiomethacrylic acid ester as a monomer is not subject to any restrictions as long as the monomer is dissolved in the above-mentioned organic solvent. You can hire them without any hassle. Since the synthesis of thioacrylic acid ester and/or thiomethacrylic acid ester is usually carried out in an organic solvent as described above, the organic solvent solution of the monomer obtained in the synthesis process of these monomers can be used as is. be able to. Moreover, it is preferable that the concentration of the monomer in the organic solvent solution is usually in the range of 1 to 50% by weight.

In the present invention, other monomers that can be copolymerized with thioacrylic acid ester and/or thiomethacrylic acid ester are not particularly limited, and may be used depending on the use of the monomer composition to be obtained. It may be selected as appropriate.

Examples include acrylic acid, methacrylic acid,
Unsaturated carboxylic acids such as maleic anhydride and fumaric acid; methyl acrylate, methyl methacrylate, benzyl methacrylate, phenyl methacrylate, 2-hydroxyethyl methacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, bisphenol A dimethacrylate, 2,2-bis(4-methacryloxyethoxyphenyl)propane, 2,2-bis(3,5
-dibromo-4-methacryloxyphenyl)propane,
Acrylic acid and methacrylic acid ester compounds such as trifluoromethyl methacrylate, urethane acrylate, and epoxy acrylate; Fumaric acid ester compounds such as monomethyl fumarate, diethyl fumarate, and diphenyl fumarate; diallyl phthalate, diallyl terephthalate,
Allyl compounds such as diallyl isophthalate, diallyl tartrate, diallyl epoxysuccinate, diallyl maleate, allyl cinnamate, allyl isocyanate, diallyl chlorendate, diallyl hexaphthalate, diallyl carbonate, allyl diglycol carbonate; styrene, chlorostyrene, methylstyrene , vinylnaphthalene, isopropenylnaphthalene, bromostyrene, dibromostyrene, and other aromatic vinyl compounds.

Among these monomers, monofunctional monomers are particularly preferred because they have a good effect of suppressing the formation of polymers in the organic solvent removal step described below. These monomers can be used alone or in combination of two or more. Further, the amount of the organic solvent solution mixed with this copolymerizable other monomer is not particularly limited, but generally speaking, the larger the amount of the other monomer mixed, the more the polymer becomes The effect of suppressing the formation of is increased. The amount of other monomers to be mixed is usually 5 to 1000 parts by weight when the other monomers to be mixed are monofunctional, based on 100 parts by weight of thioacrylic acid ester and/or thiomethacrylic acid ester. Part by weight preferably 10~
100 parts by weight, if the other monomer is difunctional or higher, 10 to 1000 parts by weight, preferably 50 to 1000 parts by weight
Parts by weight are preferred.

In the present invention, a polymerization inhibitor and other various stabilizers are mixed in the organic solvent solution of thioacrylic acid ester and/or thiomethacrylic acid ester in addition to the above-mentioned other copolymerizable monomers. You may. In particular, it is preferable to mix a polymerization inhibitor in order to enhance the effect of suppressing the formation of a polymer. Examples of such polymerization inhibitors include hydroquinone, methoxyhydroquinone, p-methoxyphenol, ter-butylcatechol, butylated hydroxytoluene, and these can be used alone or in combination of two or more. The mixing amount is not particularly limited, but is generally 0.0001-1 part by weight, preferably 0.001-0.
Preferably it is 1 part by weight.

In the present invention, the removal of the organic solvent from the organic solvent solution containing the thioacrylic acid ester and/or thiomethacrylic acid ester as a monomer with which the other copolymerizable monomers are mixed is carried out by: There are no particular restrictions. For example, a method is preferred from the viewpoint of simplicity, in which the amount of the organic solvent is reduced to about several percent using an evaporator, and then the remaining organic solvent is further removed using a vacuum pump. The temperature at which the solvent is removed from the organic solvent solution is not particularly limited as long as the solvent can be removed, and is generally from -10°C to 50°C, preferably from 0 to 30°C. In the present invention, the thioacrylate and/or thiomethacrylate are diluted with other monomers that can be copolymerized with the thioacrylate and/or thiomethacrylate, so even if the organic solvent is removed, a polymer cannot be produced. Prevented.

[0030]

Effects of the Invention According to the production method of the present invention, thioacrylic acid ester and/or thiomethacrylic acid ester, without forming a polymer during removal of the organic solvent,
A monomer composition comprising this and other copolymerizable monomers can be produced. When this monomer composition is polymerized, for example, by a known radical polymerization method, the resulting copolymer has a high refractive index, as well as excellent physical properties such as transparency and hardness. Therefore, the monomer composition can be suitably used as a raw material for organic glasses, such as optical lenses such as eyeglass lenses and optical equipment lenses, or prisms, optical disc substrates, and optical fibers, and the production method of the present invention Extremely useful.

[0031]

[Examples] The present invention will be described below with reference to Examples in order to specifically explain the present invention, but the present invention is not limited to these Examples.

Example 1 After mixing 1 g of 2-hydroxyethyl methacrylate with 100 g of a methylene chloride solution containing 10 g of methyl thioacrylate, the methylene chloride was removed using an evaporator at 25° C. under reduced pressure. Methylene chloride was removed using a vacuum pump at room temperature for 1 hour. The amount of polymer produced in the obtained monomer composition was measured using GPC (gel permeation chromatography). The column used was Hitachi Chemical Co., Ltd. A-110, and the detector was Elma Optical Co., Ltd.
A differential refractometer (Model ERC-7510) manufactured by Komatsu, Ltd. was used. As a result, the amount of polymer produced was below 0.01% by weight, which is the detection limit.

Comparative Example 1 The same operations as in Example 1 were carried out except that 2-hydroxyethyl methacrylate was not mixed. The obtained methyl thioacrylate contained 2.0
1% by weight of polymer was produced.

Comparative Example 2 Instead of mixing 2-hydroxyethyl methacrylate in Example 1, hydroquinone 0 was used as a polymerization inhibitor.
．． The same operations as in Example 1 were carried out except that 01g was mixed. The obtained methyl thioacrylate contains 0
．． 50% by weight of polymer was produced.

Example 2 Table 1 was used instead of methyl thioacrylate in Example 1.
Example 1 except that various thioacrylic acid esters or thiomethacrylic acid esters shown in were used, respectively.
The same operation was performed. In all of the obtained monomer compositions, the amount of produced polymer was 0.01% by weight or less.

[0036]

[Table 1]

Example 3 Table 2 was used instead of 100 g of methylene chloride in Example 1.
The same operations as in Example 1 were carried out except that the various types and amounts of organic solvents shown in were used. Table 2 shows the amount of polymer in the obtained monomer composition.

[0038]

[Table 2]

Example 4 In Example 1, 2-hydroxyethyl methacrylate 1
The same operations as in Example 1 were carried out except that the various amounts of monomers shown in Table 3 were used instead of g. Table 3 shows the amount of polymer in the obtained monomer composition.

[0040]

[Table 3]

Example 5 In Example 1, 1 g of ethylene glycol diacrylate was used instead of 2-hydroxyethyl methacrylate, and hydroquinone, methoxyhydroquinone, p-methoxyphenol, ter-butylcatechol or butylhydroxytoluene was used as a polymerization inhibitor. The same operations as in Example 1 were carried out except that 0.01 g of each was added. In the obtained monomer composition, the amount of polymer produced was 0.01% by weight or less regardless of which polymerization inhibitor was added.

Claims (1)

[Claims] [Claim 1] After mixing another monomer copolymerizable with the above monomer into an organic solvent solution containing a thioacrylic acid ester and/or a thiomethacrylic acid ester as a monomer, the organic solvent is removed. A method for producing a monomer composition comprising the above monomer and another monomer copolymerizable therewith.