JPS63154710A - Prepolymer and its production - Google Patents

Abstract

PURPOSE:To obtain a prepolymer which can give a cured product improved in optical properties, mechanical properties and shrinkage upon polymerization, by radical-polymerizing an alicyclic dially ester and stopping the reaction at a specified conversion. CONSTITUTION:A diallyl ester of an alicyclic dicarboxylic acid of formula I is radical-polymerized in the presence or absence of a solvent, and the reaction is stopped at a monomer conversion lower than the gel point to obtain a prepolymer comprising a polymer having 2-200 repeating structural units of formulas II and III as the principal components. In the formulas, R is H or a 1-3C alkyl, R' is H or a 1-3C alkyl, n is 1-2 and l and m are each 1-6. Examples of the compounds of formula I include dicaboxydiallyltricyclo [5,2,1,0<2.6>]decane and dicarboxydiallyldimethyltricyclo[5,5,1,0<2.6>]decane.

Description

DETAILED DESCRIPTION OF THE INVENTION a. Industrial Field of Application The present invention is directed to the use of diallyl phthalate, diallyl isophthalate, and diethylene glycol bisallyl as polymerizable and curable esterified products obtained from metal materials that are useful as raw materials for molded resins for optical materials. It is known that a three-dimensional thermosetting polymer can be obtained by directly dissolving and mixing a radical polymerization initiator into these monomers or prepolymers and heating the mixture at a predetermined temperature for a predetermined time.

Problems to be Solved by the C0 Invention However, the thermosetting polymer thus obtained does not necessarily have satisfactory optical and mechanical properties. For example, thermosetting polymers obtained from diallyl phthalate, diallyl isophthalate, etc. have excellent transparency and heat resistance, but they contain phenyl groups with large polarizability anisotropy in their molecular chains, resulting in birefringence. There are problems with optical properties such as easy dispersibility and high dispersibility, and mechanical properties such as impact resistance and bending strength are also insufficient. In addition, diethylene glycol bisallyl carbonate is used as a plastic lens for glasses under the name CR-39, but this lens has large birefringence, high water absorption, and has a low heat distortion temperature. Furthermore, it has many problems when used in high-performance optical materials, such as optical disk applications, and is therefore not suitable for these applications.

Further, these thermoset products are usually obtained by cast polymerization of monomers in the presence of a radical catalyst. However, a large polymerization shrinkage rate during polymerization is a common drawback of these thermosetting polymers, and there are limits to their application to optical materials that require precision molding, such as optical disk materials. In order to solve this problem of polymerization shrinkage, we synthesized a low-molecular-weight prepolymer in which only one carbon-carbon double bond of these bifunctional monomers was polymerized, and added a radical crosslinking agent to this prepolymer. The shrinkage rate during polymerization is reduced by processing the polymer and thermally curing it in a mold.

However, although conventional prepolymers can reduce the above-mentioned problem of polymerization shrinkage, the current situation is that they cannot improve the optical properties and surficial properties mentioned above, which are the essential drawbacks of the resulting cured product. be.

The object of the present invention is to develop an alicyclic dicarbonate which has improved optical properties, mechanical properties, and large shrinkage rate during polymerization of a cured product obtained by crosslinking a conventional esterified product of an unsaturated alcohol and a carboxyl group-containing compound. An object of the present invention is to provide a novel prepolymer of an acid diallyl compound and a method for producing the same.

d. Means for solving the problem The prepolymer of the present invention is produced by polymerizing an alicyclic diallyl compound represented by the following general formula ([) with a radical polymerization initiator in the presence or absence of a solvent. can be obtained by

The alicyclic diallyl compound represented by the above formula (II[) used in the present invention includes dicarboxydiallyltricycloC5,2,1,02.6]decane, dicarboxydiallyldimethyltricyclo[5,2, 1°02°6] Decane, dicarboxydiallyl pentacyclo C6,5,1
, 1”・6,02・7,00・+3] Pentadecane, etc. can be mentioned.

Other monomers can also be copolymerized during prepolymer production, such as phthalic acid, isophthalic acid, terephthalic acid, hexahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid, naphthalene dicarboxylic acid, maleic acid, etc. Examples include diallyl esters of dibasic acids such as fumaric acid, succinic acid and adipic acid, and monoallyl esters of monobasic acids such as benzoic acid, toluenecarboxylic acid, naphthalenecarboxylic acid and cyclohexanecarboxylic acid.

Furthermore, specific examples of the radical polymerization initiator used in the prepolymer production reaction include benzoyl peroxide, di-t-butyl peroxide, diisopropyl peroxydicarbonate, methyl ethyl ketone peroxide, lauroyl peroxide, and dicumyl peroxide. oxide, acetylcyclohexylsulfonyl peroxide, isobutyl peroxide, cumyl peroxy neodecanoate, diallyl peroxy dicarbonate, di-n-propyl peroxy dicarbonate, dimyristyl baroxy dicarbonate, cumyl peroxy neo hexanoate, di(2-ethoxyethyl)peroxydicarbonate, di(methoxyisopropyl)peroxydicarbonate, t-hexylperoxyneohexanoate, di(3-methylmethoxybutyl)peroxydicarbonate, t-butyl peroxyneododecanoate, cumene hydroperoxide, t-butyl hydroperoxide, hydrogen peroxide, L-oc≠ruberoxyhenzoate, t-butyl peroxyisopropyl carbonate, t-butyl peroxybenzoate, Peroxides such as bis(L-butylperoxyisopropyl)benzene and t-butylcumyl peroxide can be mentioned. Moreover, these polymerization initiators can be used alone or in combination.

Furthermore, these peroxide-based initiators are combined with a reducing agent,
It may also be used at lower temperatures as a so-called redox initiator.

The prepolymer of the present invention can be synthesized by reacting with a radical polymerization initiator without using a solvent or in the presence of a solvent, but the polymerization rate is usually lower when a solvent is used than in a system that does not use a solvent. However, it is preferable because it increases the conversion rate of 7-mer until it reaches the gelation point (the point at which fine structure is formed), which makes post-treatment steps such as recovery of the prepolymer advantageous.

There are no particular restrictions on the solvents that can be used, as long as they can dissolve the monomer and prepolymer, such as hydrocarbon solvents such as benzene, toluene, cyclohexane, and n-heptane, and cyclic ethers such as tetrahydrofuran and dioxane. Examples include compounds.

In addition, as molecular weight regulators for prepolymers, allyl compounds such as allyl alcohol, allyl bromide, allyl chloride, and allyl phenyl ether, compounds having a benzyl group such as benzyl alcohol, and N,N-dimethylformamide, N,N-dimethyl Compounds such as acetamide can be used.

Usually, the amount of the radical polymerization initiator used is 1710 to 1/1000 per mole of the monomer of the alicyclic diallyl compound.
Mole, the amount of solvent used is 172 to 172% by weight relative to the monomer.
Twenty times the amount can be used.

The polymerization temperature or polymerization time varies depending on the type of radical polymerization initiator, but is O''C~200℃, preferably 30~200℃.
180°C, more preferably 50 to 150°C for 10 minutes to 50 hours, preferably 30 minutes to 20 hours,
More preferably, the time can be selected within the range of 1 to 10 hours,
Polymerization can be carried out until just before gelation occurs, and the reaction is stopped at a monomer conversion rate lower than the gelation point defined by the respective reaction conditions (solvent, monomer temperature, initiator concentration). For example, when using 100 parts by weight of dicarboxytricyclo(5,2,1,02=6)decane as the alicyclic diallyl compound, 300 parts by weight of cyclohexane as the solvent, and 2 parts by weight of benzoyl peroxide as the polymerization initiator, cyclohexane The polymerization time until the gelation point is reached under the polymerization condition of reflux temperature is 3.5 hours, and the polymerization conversion rate at that time is 50%.

After the reaction, the reaction solution is poured into a suitable poor solvent for the prepolymer, recovered and, after drying, can be used as a molding material.

Examples of the poor solvent for the prepolymer include methanol, ethanol, isopropyl alcohol, and ethylene glycol diethyl ether. The prepolymer of the present invention, which is a reaction product, has the following general formula (1
) and/or (If) having a repeating structural unit.

The total number of repeating structural units having the structural formula represented by general formula (1) and/or (I[) in the prepolymer of the present invention is 2 to 200, preferably 2 to 200.
150, more preferably 5-100.

The repeating structural unit having the structural formula represented by the above general formula (1) and/or (II) is 7 in the prepolymer.
The content is preferably 0 weight % or more, more preferably 75 weight %, particularly preferably 80 weight %. The molecular weight of the prepolymer of the present invention is a polystyrene equivalent molecular weight measured by gel permeation chromatography (GPC), and the average molecular weight is 500 to 30.0.
It is 00.

Injection molding is preferred as a molding method for molding the prepolymer of the present invention into a product, but methods commonly used for molding thermosetting resins, such as cast molding, can be used.

During molding, it is preferable to further add a polymerization initiator to the prepolymer of the present invention and mold it to create a three-dimensional structure. Furthermore, other monomers may be added during molding. Examples of the monomer include phthalic acid, isophthalic acid, terephthalic acid, hexahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid,
These include diallyl esters of dibasic acids such as naphthalene dicarboxylic acid, maleic acid, fumaric acid, succinic acid, and adipic acid, and monoallyl esters of monobasic acids such as benzoic acid, toluenecarboxylic acid, naphthalenecarboxylic acid, and cyclohexanecarboxylic acid. be able to.

In addition, the molding conditions for the molding are such that the recovered prepolymer is kneaded with 0.1 to 10 parts by weight of a radical polymerization initiator per 100 parts by weight of the prepolymer under conditions that do not cause gelation in a kneader or a molding machine. The resulting composition can be compression molded or injection molded and cured, for example, under conditions of 100 to 250"C for 11 to 24 hours. Further, depending on the molded product, a post-curing treatment may be performed.

Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto.

Example 1 500 equipped with reflux condenser, stirring motor, and nitrogen inlet tube
dicarboxytricyclo(
5,2,1,0"・6] 100 g of dehydrogen, 100 g of cyclohexane, and 4 g of benzoyl peroxide were charged in a nitrogen atmosphere and polymerized at 80°C for 3 hours. When the polymerization conversion rate reached 45%, The reaction was stopped. At this time, no gel was observed in the reaction system.

After the reaction, the polymerization solution was poured into a large amount of cooled methanol to solidify and precipitate the prepolymer. The prepolymer was collected in a furnace and then dried at 50° C. for 15 hours to obtain 60 g of resinous solid (polymer yield: 60%). IR of the obtained prepolymer
The absorption spectrum (KB, tablet method) is shown in FIG.

C-11 stretching vibration at 2960Cffl-', 1730c
〉C=0 stretching vibration of ester group in m-', 1170~l
C-O stretching vibration of ester group at 180 cm-', 930
cm-'=C1 (absorption of out-of-plane vibrations was observed).

Furthermore, a spectrum assigned to the following structure was observed by 'H-NMR.

Attribution Integral value a 1.3~
3.0ppm 14.4b approx. 4.5pp
m 1.59 C approx. 5.3 ppm, 1.39 d approx. 5.9 ppm 0.51 e 3.5-4.3 ppm 0
．． 69 From the above results, the structure of the prepolymer has 0 residual carbon-carbon double bonds for 1 dicyclopentadiene skeleton.
．． 5 to 0.8, and considering the measurement accuracy of 'H-NMR, the structure of the main component of the prepolymer supports the above structure.

In addition, the iodine value of the obtained prepolymer was 77,
This corresponded to 45% of the iodine value of 173 of the raw material monomer. Combining the above analysis results, it can be concluded that the main structure of the prepolymer has the above structure.

From GPC of the obtained prepolymer (measurement conditions: THF
30°C) The number average molecular weight of the main peak is 5500 (
(polystyrene equivalent molecular weight).

Further, this prepolymer was soluble in hydrocarbons such as benzene, toluene, and cyclohexane, cyclic ethers such as tetrahydrofuran and dioxane, and halogenated hydrocarbons such as chloroform and carbon tetrachloride.

2 parts by weight of dicumyl peroxide were added to 100 parts by weight of the obtained prepolymer, and after kneading this at 60°C in a kneader, the obtained composition was compression molded at a temperature of 120°C for 15 minutes. A molded product was obtained.

Regarding this molded article, birefringence, dispersion rate, bending strength, light transmittance, heat distortion temperature, water absorption, and polymerization shrinkage were measured using the measurement methods shown below. The results are shown in Table-1.

1st calm: Measured with a polarization strain meter.

Classification rate: Measured using an Asobe refractometer.

Yuzuru MA rate: Measured using a haze meter on a test piece with a thickness of 21 mm.

The skin and back of the chest were measured using the method of JIS K 6911.

Water absorption: Measured by ASTM D570 method.

Seed peel: Measured by ASTM D 648 method.

Acquisition and mounting efficiency: Measured according to the method of JIS K 6911.

Comparative Example 1 Prepolymer of diallyl phthalate (average molecular weight 4500
), 2 parts by weight of benzoyl peroxide as a radical polymerization initiator was added to 100 parts by weight, a molded article was prepared in the same manner as in Example 1, and its physical properties were evaluated. The results are shown in Table-1.

Examples 2 to 5 Prepolymers were prepared according to the formulation shown in Table-1,
Further, a molded product was prepared in the same manner as in Example 1 to obtain a cured product, and its physical properties were evaluated. The results are shown in Table-1.

Furthermore, the structure assigned from the IR absorption spectrum and 'H-NMR absorption spectrum of the prepolymer obtained in each polymerization was almost the same as the structure of the prepolymer obtained in Example 1.

Comparative Example 2 A molded article was prepared in the same manner as in Example 1 by adding 4 parts by weight of dicumyl peroxide to 100 parts by weight of the monomer shown in Table 1, and its physical properties were evaluated. The results are shown in Table-1.

Comparative Example 3 Dicarboxytricyclo(5,2,L0
2.6] 4 parts by weight of dicumyl peroxide is used as a curing agent for 100 parts by weight of delinquent (4 parts by weight is used to achieve the same crosslinked structure since the residual double bonds in the prepolymer are twice as many). A molded article was prepared in the same manner as in Example 1, and its physical properties were evaluated. The results are shown in Table-1.

e. Effect of the invention The prepolymer obtained from the diallyl alicyclic dicarboxylic acid of the present invention is a novel product that provides a three-dimensional crosslinked product with better optical properties than the three-dimensional crosslinked product obtained from the conventional aromatic diallylcarboxylic acid. It is a precursor compound with a similar structure.

The polymer obtained by the present invention has significantly improved polymerization shrinkage properties and birefringence, and also has the characteristics of impact resistance, high refractive index, and heat resistance, and is highly valued as an optical material. Are better. In addition, as optical materials, for example,
So-called lenses and prisms for eyeglasses, still cameras, video cameras, telescopes, sunlight condensing, etc.
It can be used as a material that is required to have the function of transmitting or reflecting light, such as light guiding elements such as optical waveguides, discs such as video discs, audio discs, and compact discs. Furthermore, since the polymer obtained by the present invention has good electrical insulation properties, it can also be used as a sealing material for electrical and electronic parts.

[Brief explanation of the drawing]

FIG. 1 shows the I of the prepolymer obtained in Example 1.
It is a figure showing an R absorption spectrum.

Claims (1)

[Claims] (1) A prepolymer whose main component is a polymer having 2 to 200 repeating structural units represented by formulas (I) and (II). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) [In the formula, R is hydrogen or an alkyl group having 1 to 3 carbon atoms, R
' is hydrogen or an alkyl group having 1 to 3 carbon atoms, and n is an integer of 1 to 2. l and m are integers of 1 to 6. ]
(2) General formula (III) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(III) [In the formula, R is hydrogen or an alkyl group having 1 to 3 carbon atoms, R
' is hydrogen or an alkyl group having 1 to 3 carbon atoms, and n is an integer of 1 to 2. l and m are integers of 1 to 6. ]
A method for producing a prepolymer, which comprises radically polymerizing a diallyl alicyclic dicarboxylic acid represented by the formula in the presence or absence of a solvent, and stopping the reaction at a monomer conversion rate lower than a gel point.