JPS61130330A - Production of resin molding excellent in heat and chemical resistance - Google Patents

Abstract

PURPOSE:To obtain the titled molding excellent in heat and chemical resistances and dimensional stability, by polymerizing a carboxyl group-containing vinyl monomer with a glycidyl group-containing vinyl monomer and other copolymerizable monomers. CONSTITUTION:4-30wt% at least one carboxyl group-containing vinyl monomer (e.g., methacrylic acid), 4-96wt% at least one glycidyl group-containing vinyl monomer (e.g., beta-methylglycidyl methacrylate) and, optionally, 0-92wt% other copolymerizable monomers (e.g., methyl methacrylate) in the presence of a polymerization initiator and a chain transfer agent to obtain a transparent thermosetting resin premolding having a residual unreacted monomer content of below 20wt% and a second-order transition point <=120 deg.C. This premolding is cut to a size corresponding to that of a desired molding and molded by heating quickly to 150 deg.C or higher and pressing it against a mold or by sandwiching it between molds heated to 150 deg.C or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel method for producing a molded article with excellent heat resistance and chemical resistance. The present invention also provides a method for producing resin molded articles for glazings, eyelids, lenses, prisms, etc., which require transparency, heat resistance, and chemical resistance, and are each 1 m in length and used for original academic parts. .

[Conventional technology]

Traditionally, inorganic glass has been mainly used for dazzling purposes, eyelids, and various optical parts, but in recent years, thermoplastic resins such as polycarbonate, polystyrene, and polymethyl methacrylate, as well as those described in U.S. Patent No. 2,542,386, have been used. [Problems to be solved by the invention] Diethylene glycol bisallyl carbonate resin, which is a thermosetting resin such as The inorganic glass has the disadvantage that it has excellent heat resistance and chemical resistance, has a large ratio (1) and (2), and is relatively thin. On the other hand, it is used as a plastic material.
Among these, thermoplastic resins such as polycarbonate, polystyrene, and polymetal methacrylate are lightweight and have excellent processability, and although they have poor heat resistance and chemical resistance, the polymerization method allows monomers to be injected into molds. Since it is a so-called "press-forming universal type" which is then thermally cured, it has the disadvantages of poor productivity and poor dimensional stability due to volumetric shrinkage during curing. The present invention overcomes the drawbacks of the conventionally used plastic materials and provides a method for producing transparent resin with excellent heat resistance and chemical resistance with high productivity. Ru.

[Means for solving problems]

The inventors of the present invention have developed a method that has excellent heat resistance and chemical resistance, which are the advantages of thermosetting resins, without impairing the mass productivity and excellent moldability, which are the advantages of conventional thermoplastic resins. Study of materials and molding methods used to create transparent resin
- By using transparent thermosetting preforms as shown below and improving moldability, we have been able to produce the desired 7'C transparent resin with excellent heat resistance and chemical resistance. We found that it can be manufactured with good performance.

The invention has been completely completed. In order to achieve all of the above objects, the present invention has a structure of a preform that includes a carboxyl group-containing vinyl monomer, a glycidyl group-containing vinyl monomer, and other copolymerizable monomers in terms of monomer acid content. 4 to 3 monomers each
0][[, Contains 4 to 96% by weight and 0 to 92% by weight,
The remaining unreacted monomer is removed by 20% by weight and t%.
Established a method to obtain a molded product with good dimensional accuracy by heating and molding a transparent thermosetting preform at a temperature of 150°C or higher so that the secondary transition point is 120°C or lower, and then thermosetting it. I have a friend. The glycidyl group-containing monomer, which is the crosslinkable monomer used in the present invention, and the carhokyfur group-containing monomer, which is the curing agent, hardly undergo a curing reaction at temperatures below 120°C. Therefore, the above-mentioned transparent thermosetting preform is solid at room temperature and easy to handle, and at temperatures above 150°C, it softens and exhibits thermoplasticity at the initial stage of heating, but after 1 hour it undergoes thermosetting reaction. It has a tendency to progress and harden. Therefore, it is characteristic that the molding method of thermoplastic resin can be applied even though it is a thermosetting resin by selecting all the molding conditions. For this reason,
Ditto for productivity, friend. Specific examples of the carphokyfur group-containing vinyl monocap to be formed into the transparent thermosetting preform of the invention include methacrylic acid, acrylic acid, itaconic acid, crotonic acid, and the like. Specific examples of the glycidyl group-containing vinyl monomer include glycidyl acrylate, glycidyl methacrylate, β-methylglycidyl acrylate, and β-methylglycidyl methacrylate. In particular, the β-methylglycidyl group-functionalized monomer has relatively good thermal stability of the epoxy group, and can be used as a monomer for preforms, which undergoes a complete curing reaction with carboxyl groups in the acid temperature range. It is suitable. Specific examples of copolymerizable monomers used in addition to these crosslinkable monomers include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, 1so-propyl methacrylate, and n-butyl methacrylate.

1so-butyl methacrylate, 5ec-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, butyl acrylate, ethyl acrylate, n-propyl acrylate), iso~propyl acrylate, n-butyl acrylate, styrene,
Examples include, but are not limited to, α-methylstyrene, trifluoroethyl methacrylate, pentachloroglovir methacrylate, and the like. However, the content of the calhoquinol group-containing monomer and the glycidyl n-containing monomer in the preform is less than 4% by weight.
If the chrycidyl group-containing monomer component exceeds 961 t%, the crosslinking density of the molded product will be too low when heat-cured at a temperature of 150°C or higher, and sufficient heat resistance and chemical resistance may not be obtained. Otherwise, the problem arises that foaming occurs, impairing transparency. On the other hand, the content of carboxyl group-containing monomer is 30Xt
%, hygroscopicity increases and one-dimensional stability deteriorates. Therefore, the content of the carboxyl group-containing monomer and the glycidyl group-containing monomer contained in the composition is 4 to 30, respectively.
weight and 4 to 96% by weight, preferably 7 to 25 tc
II and 7 to 80 JE is preferable. In addition, if the amount of monomer remaining in the preform exceeds 20X, the softening temperature of the mold becomes too low, the viscosity of the resin increases, and the preform deforms when handled. The workability becomes worse. Therefore, it is preferable that the amount of monomer remaining in the set 55c is less than 20111 units.

It is preferable that the transparent thermosetting resin preform used in the present invention be produced by a bulk one-piece method. The initiator used in the first reaction is preferably a radical initiator in the medium temperature range such as azobisisobutyronitrile, azobisvaleronitrile, benzoyl peroxide or lauryl peroxide.The chain transfer agent is preferably n-dodecyl. Captan, n-octylmercaptan, n-butylmercaptan, and t-butylmercaptan are preferably used. The amount of these initiators and chain transfer agents added and l(AI-
The conditions are appropriately set based on known techniques, taking into consideration the assembly of monomers so that the residual monomer content is less than 20% by weight.

Further, in order to suppress the thermosetting reaction between the carboxyl group-containing monomer and the glycidyl group-containing monomer as low as possible, the gold production temperature is preferably set to 100° C. or lower.

As a method for obtaining a final molded body from the transparent thermosetting preform of the present invention, for example, the preform is cut into a size that matches the dimensions of the molded product intended for smoothing. Then, the preform is rapidly heated to 150° C. or higher with an infrared heater or the like, and then piezoelectrically molded into a * mold, or the preform is placed over a mold heated to 1,500° C. or higher and pressurized. At this time, a thermosetting reaction proceeds at the same time and shaping is performed, but unlike curing from a monomer such as "Numei Bandai", the body convergence accompanying polymerization is extremely small, so dimensional accuracy is reduced. A feature of this method is that good molded products can be obtained in a short time.If the product is heated for a long time at 11111 above 150°C before shaping, a thermosetting reaction will proceed and the product will harden.
It is desirable to perform molding by minimizing the time difference between heating and shaping.

Example 1 1120 parts of methacrylic, 80 parts by weight of β-methylglycidyl methacrylate, 0.05 parts of azobisisobutyronitrile, 0.05 parts of n-octyl mercaptan.
15 parts by weight of polymerized gland at.

A frame made of PVC tube with an outer diameter of 5 mm was sandwiched between two tempered glass plates with a Teflon film of 50 μm thickness attached to the surface, and the frame was poured into the tank space and heated to 70°C.
A transparent thermosetting pre-formed body with a thickness of 4 cylinders was created by crushing it in a constant temperature water bath for 14 hours. A friend of mine to investigate the secondary transformation of this preform, Toyo Baldwin Bipron 1) DV[1
-Using an EA type dynamic viscoelasticity measurement device, frequency 110Hz
The complex modulus of elasticity (Jli2N
1. The monomer remaining in the preformed body was dissolved in 700 ml of the resin plate, and the peak of ) was heated to 85°C.
When quantified using a gas chromatogram, it was found to be 10%. Cut this preform into t-30ttns squares,
Sandwiched between flat molds heated to 0℃, immediately VC7
After leaving it for 10 minutes while pressurized at a pressure of 0/-,
It was cooled and peeled from the mold to obtain a thermoset sheet with a thickness of about 200 μm. The dynamic viscoelastic properties of this sheet were examined under the same conditions as the preform, and the peak temperature was 180°C. When this sheet was immersed in a solvent of t-acetone and methylene chloride for one day at room temperature and its surface condition was observed, no change was observed in the surface condition, indicating that it had extremely good chemical resistance. It has been found. or,
When the total transmittance of the CIJ viewing source was measured using a spectrophotometer, it showed a transmittance of 90% or more between 400 nm and 800 nm, showing a light transmittance equivalent to that of polymethyl methacrylate.

Example 2 920 parts by weight of methacrylic, 40 parts by weight of β-methylglycidyl methacrylate, 4 o of methyl methacrylate! it
g, azobisisobutyronitrile 0.05 part, n
-A polymerization stock solution containing 0.15 parts of octyl mercaptan was polymerized under the same conditions as in Example 1 to produce a transparent thermosetting preform having a thickness of 4 m. When the EI peak temperature and residual monomer ti were measured under the same conditions as in Example 1, they were 90°C and 9.9°C, respectively. O]i[%. This preform was pressure-molded under the same conditions as in Example 1 to a thickness of approximately 19 mm.
A heat-cured sheet of 0μ was obtained. When the dynamic viscoelastic properties of this sheet were investigated under the same conditions as the preform, E'
Peak temperature was 178°C. When this sheet was immersed in a solvent of t-acetone and methylene chloride at room temperature for one day and its surface condition was observed, there was no change in appearance and it showed poor chemical resistance. When measuring heavy metal transmission in clear light using a spectrophotometer, it was found that 90
It had a transmittance of t-bo of 1.5% or more, and exhibited light transmittance equivalent to that of polymethyl methacrylate.

Example 3 A polymerization stock solution consisting of 15 mt parts of itacone, 40 parts by weight of β-methylglycidyl acrylate, 45 parts by weight of methyl methacrylate, 0.05 coulometric part of azobisisobutyronitrile, and 0.1'5 parts by weight of n-octyl mercaptan. A transparent thermosetting preform having a thickness of 4 was prepared by combining all the materials under the same conditions as in Example 1. i under the same conditions as Example 1
The peak temperature and residual monomer content were measured at 60°C and 10.0JF, respectively. This preform was pressure-molded under the same conditions as in Example 1 to a thickness of about 160 mm.
A heat-cured 7-t of μ was obtained.

When the dynamic and viscoelastic characteristics of this sheet were investigated, the peak temperature was 160°C. When this sheet was immersed in acetone and methylene chloride solvent for one day at room temperature and the surface condition was completely observed, no change was observed in appearance, indicating excellent chemical resistance. When the transmittance of clear light was measured using a spectrophotometer, it was found to be 90% between 400 nm and 8 U Onm.
% or more, and has a light transmittance equivalent to that of polymethyl methacrylate.

Comparative Example 1 3 parts by weight of methacrylic acid, 47 parts by weight of I-methylglycidyl methacrylate, 50 parts by weight of methyl methacrylate,
A transparent preform f with a thickness of 4fi was prepared by polymerizing a polymerization stock solution consisting of 0.05 parts of azobisin butyronitrile and 0.15 parts of n-octyl mercaptan under the same polymerization conditions as in Example 1. did. The E" peak temperature and residual monomer t were measured in the same manner as in Example 1 and found to be 87°C and 101 it%. A sheet with a thickness of approximately 150 μm was formed by pressure forming under the same conditions as in Example 1. The peak temperature of this sheet was 110°C. When this sheet was immersed in acetone and methylene chloride solvent at room temperature for one day, it swelled and cracked.

Comparative Example 2 920 parts by weight of methacrylate, 3 parts by weight of β-methylglycidyl methacrylate, 7 mN parts of methyl methacrylate,
A polymerization stock solution consisting of 0.05 parts by weight of azobisin butyronitrile and 0.15 parts by weight of n-octyl mercaptan was polymerized under the same polymerization conditions as in Example 1 to obtain transparent preforms with 4 thicknesses. Created. When E' peak temperature and residual monomer amount t were determined in the same manner as in Example 1, they were each 1.
00°C and 8% by weight. A sheet with a thickness of about 140 μm was obtained by pressure forming under the same conditions as in Example 1. The E' peak of this sheet was 115°C. When this sheet 2 was immersed for one day in a solvent of A7 and methylene chloride at room temperature, cracks appeared.

Comparative Example 3 A transparent preformed plate was prepared under the same conditions as in Example 1, except that the content of n-octyl mercaptan and the polymerization time were 0.3 N parts and 2 hours, respectively. This resin plate was soft and difficult to remove from the polymerization cell. When the amount of residual monomer gold was examined, it was found to be 35Xt.

Because it is soft and sticky, it is difficult to handle and has practical problems when used for pressure molding.

Comparative Example 4 A resin plate similar to that in Example 1 was pressure-molded under the same conditions as in Example 1 except that the mold temperature was 140° C. to obtain a resin plate with a thickness of 1 inch. The Blj peak temperature of this resin plate is 110℃
Met. It was immersed in acetone and methylene chloride solvents at room temperature for one day, causing some swelling and cracking.

Comparative Example 5 20 parts by weight of methacrylic acid, 80 parts by weight of β-methylglycidyl methacrylate! parts, Jitter 7, 0.05 parts by weight of butyl peroxide, 0 parts by weight of n-octyl mercaptan.
．． A stock solution containing 10 parts by weight was heated to a temperature of 120 in a constant temperature bath.
Polymerization was carried out under the same conditions as in Example 1 except that the temperature was 0.degree. C. to produce a transparent thermosetting preform having a thickness of 4 mm. Example 1
The E" peak temperature was measured under the same conditions as 140
I failed at C. This sheet was not bathed in solvents, so it was impossible to measure the amount of residual monomer. Pressure molding was attempted under the same conditions as in Practical Example 1, but no deformation occurred and molding was impossible.

Comparative Example 6 3 parts of methacrylic acid, 3Nt parts of β-methylglycidyl methacrylate, 94 parts of methyl methacrylate! [S, A polymerization stock solution consisting of 0.05 parts by weight of azobisin butyronitrile and 0.15 parts of n-octyl mercaptan was combined under the same conditions as in Example 1, and a 4fi transparent solution #4 was prepared.
A thermosetting preform gold was prepared. Measured under the same conditions as Example 1, E' peak @ degree and residual monomer 1t1r were 91°C and 8.0''iL amount%, respectively. This preform was processed under the same conditions as Example 1. A sheet of about 130 μm in thickness was obtained by pressure forming.The E'heat temperature of this sheet was 112°C.When this sheet was immersed again in a solvent of acetone and methylene chloride at room temperature for 1 day, I[4
L crack occurs and friend.

〔Effect of the invention〕

The preform used in the invention is in a glass state at room temperature.
] Plasticity t- transparent thermosetting, -! ! i=The molecular design of the fat composition is such that the thermosetting reaction proceeds in the molding temperature range of 9,150° C. or higher. therefore,
At room temperature, it can be handled in the same way as general thermal I'T plastic resins, and some of the molding methods used for thermal 5I plastic resins, such as pressure-compression molding, can be applied, making it relatively simple. It is suitable for mass production. Furthermore, since the final molded product obtained from the preform is thermoset, it has excellent heat resistance, chemical resistance, and dimensional stability.

It combines the advantages of both conventional thermoplastic and thermosetting plastics.

Claims (1)

[Claims] At least one carboxyl group-containing vinyl monomer 4-
30% by weight, 4-96% by weight of at least one glycidyl group-containing vinyl monomer, and 0 other copolymerizable monomers.
A preformed body consisting of ~92% by weight, the unreacted monomer remaining in the molded body is less than 20% by weight, and the secondary transition point of the molded body is 120°C or less. A method for producing a resin molded body with good dimensional accuracy, excellent heat resistance, and chemical resistance, characterized by heating a hardened preform at a temperature of 150° C. or higher.