JPS62192413A - Thermosetting composition excellent in transparency - Google Patents

Abstract

PURPOSE:To obtain the titled composition which can be obtained in god productivity and give lenses, prisms, etc., excellent in transparency, by mixing a carboxyl group-containing vinyl monomer, a glycidyl group-containing vinyl monomer, other copolymerizable monomers and (pre)(co)polymers thereof. CONSTITUTION:The titled composition is obtained by mixing 4-30% (in terms of the monomer weight, the same applies hereinbelow) carboxyl group-containing vinyl monomer such as (meth)acrylic acid, itaconic acid or crotonic acid or (pre)(co)polymers thereof with 4-96% glycidyl group-containing monomer such as glycidyl (meth)acrylate or beta-methylglycidyl (meth)acrylate or (pre)(co)polymers thereof and 0-92% other copolymerizable monomers such as methyl (meth) acrylate or (pre)(co)polymer thereof so that the total of said monomers and the total of said (pre)(co)polymers may be 20-70% and 80-30%, respectively. This composition of a suitable flow is poured into a mold, molded at 140 deg.C and cured by heating to 150 deg.C above.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application] The present invention relates to a novel transparent thermosetting composition. The present invention also seeks to provide a thermosetting composition suitable for producing various mechanical parts such as glazings, glasses and lenses, and prisms that require transparency, heat resistance, and chemical resistance. It is something to do.

[Conventional technology]

Traditionally, inorganic glass has been used for glazing, eyeglasses, and optical components, but in recent years polycarbonate, a thermoplastic resin, has been used.

Polystyrene and polymethyl methacrylate and diethylene glycol bisallyl carbonate resins, which are thermosetting resins such as those described in U.S. Pat. No. 2,542,386, are being utilized.

[Problem that the invention seeks to solve]

Inorganic glasses conventionally used for glazing, eyeglasses, and 6m optical components have excellent heat resistance and chemical resistance, but have the drawbacks of high specific gravity and easy breakage. -Among the materials used as plastic materials, polycarbonate is a thermoplastic resin.

Although polystyrene and polymethyl methacrylate are lightweight and have excellent processability, they have the disadvantage of poor heat resistance and chemical resistance. In addition, diethylene glycol bisallyl carbonate resin, which is a thermosetting resin, has relatively good heat resistance and chemical resistance, but the polymerization method involves injecting the monomer into a mold and then thermosetting it, which is a so-called one-cast mold. The ninth grade, I, has the drawbacks of poor productivity and poor dimensional stability due to volumetric shrinkage during curing. The present invention overcomes the drawbacks of conventionally used plastic materials and improves heat resistance.

The present invention provides a transparent thermosetting composition that has excellent chemical resistance and is suitable for producing transparent resins.

[Ninth way to solve the problem]

The inventors of the present invention have discovered that thermosetting resins have superior heat resistance, chemical resistance, and transparency without sacrificing the advantages of conventional thermoplastic resins, such as mass production and excellent moldability. We have been actively investigating materials suitable for making fats, but we have developed heat-resistant materials by using transparent thermosetting molds and acids, as shown below, and by devising molding methods.

The present invention was completed based on the discovery that it is possible to produce a transparent resin with excellent chemical resistance and good physiological properties.

That is, the present invention provides at least one carboxyl group-containing vinyl/LAL polymer (At 4
~30% by weight, at least 1@ glycidyl group-containing vinyl monomer (B) 4~q6iQc4 and other copolymerizable monomers (a) ~92ffi! %, and the unreacted monomer remaining in the molded article is 20% by weight or more and less than 70% by weight, preferably 60% by weight or more and 60% by weight or more. The object of the present invention is to provide a heat-exchange curable composition with excellent transparency.

The glycidyl group-containing monomer (4), which is a crosslinkable monomer constituting the thermosetting composition of the present invention, and the carboxyl group-containing monomer (4), which is a curing agent, hardly undergo a curing reaction at temperatures below 120°C. Ninth, the transparent thermosetting composition is stable at room temperature and easy to handle;
The above materials soften and exhibit fluidity at the initial stage of heating, but have the property of hardening as a thermosetting reaction progresses over time. By selecting the molding conditions accordingly, it has the characteristic that the shaping method of thermoplastic resin can be applied even though it is a thermosetting resin. This will dramatically improve productivity.

The carboxyl group-containing vinyl monomer constituting the transparent thermosetting composition of the present invention (specific examples of Al include methacrylic acid, acrylic acid, and itaconic acid).

Examples include crotonic acid. Further, glycidyl, a group-containing vinyl monomer (specific examples of Bl include glycidyl acrylate and glycidyl methacrylate.

Examples include β-methylglycidyl acrylate and β-methylglycidyl methacrylate.

In particular, the β-methylglycidyl group-containing monomer has relatively good thermal stability of the epoxy group, and since it undergoes a curing reaction with carboxyl groups in the molding temperature range, it is suitable as a monomer for the thermosetting composition of the present invention. It is something. Specific examples of the monomer tc+ used in addition to these crosslinking monomers include methyl methacrylate, ethyl methacrylate), n-7'lopyl methacrylate, IBO-propyl methacrylate, n-butyl methacrylate, 180-butyl methacrylate, ec-butyl methacrylate.

t-butyl methacrylate, 2-ethylhexyl methacrylate, methyl acrylate, ethyl acrylate,
n-propyl acrylate.

Examples include 180-propyl acrylate, n-butyl acrylate, styrene, α-methylstyrene, 2゜2,2-trifluoroethyl methacrylate, 2゜2.4A3-pentafluoropropyl methacrylate, but are not limited to these. isn't it. In addition, these monomers (Al, (B1.) may be a homopolymer, a copolymer, or a partial polymer. When the carboxyl group-containing monomer and glycidyl group-containing monomer fraction is less than 4% by weight or the glycidyl group-containing monomer component is 96% by weight or more, it is thermally cured at a temperature of 150°C or higher for a fixed time. - The degree of crosslinking is too low, resulting in problems such as insufficient heat resistance and chemical resistance, or foaming, which impairs the final transparency. - Content of carboxyl group-containing monomers If it exceeds 30%, hygroscopicity increases and dimensional stability deteriorates.Therefore, the amount of carboxyl group-containing monomers and glycidyl group-containing monomers contained in the composition in terms of monomer composition. The body content is 4-30% by weight and 4-9%, respectively.
6% by weight, preferably 7-25% and 7-80% by weight
1:%. Furthermore, if the monomer contained in the thermosetting composition is less than 20% by weight, the flow temperature of the composition becomes too high and crosslinking reaction proceeds during shaping, making injection molding difficult. If the monomer content in the composition exceeds 70 wt.

Therefore, the monomer remaining in the composition is 20% by weight or more and less than 70% by weight, preferably 30% by weight or more and less than 60% by weight.
It is preferable to make it less than

A composition for obtaining a final resin molded article from the highly transparent and slightly thermosetting composition of the present invention fc Two-stage molding in which the temperature is raised to 150°C or higher to carry out a thermosetting reaction after molding at a temperature of 140°C or lower The method is preferably used. A specific preferred method is, for example, a method in which the composition is injected into a mold heated to 150° C. or higher using an injection molding machine, and then thermally cured, and then the gold is peeled off. An example of a method is to inject the composition into a mold at a temperature of 150° C. or more, heat it to a temperature of 150° C. or higher to thermally cure it, and then peel it from the mold to obtain a molded product. The feature of this method is that after the molded product is peeled from the mold, the volume shrinkage due to cooling is extremely small, and a molded product with good dimensional accuracy can be obtained in a short time. However, if the composition is heated for a long time at a temperature of Kf 50° C. or higher before shaping, a thermosetting reaction will proceed and the composition will harden, so care must be taken when molding at a temperature of 150° C. or higher. The two-stage molding method is, in this sense, a suitable method for the thermosetting composition of the present invention.

Example] Next, the present invention will be specifically explained using examples.

Example 1 A superposition stock solution consisting of 100 parts by weight of β-methylglycidyl methacrylate, 05 parts by weight of azobisisobutyronitrile α, and 115 parts by weight of n-octyl mercaptan was pasted on the surface with a polyester film having a thickness of 25μ and reinforced with two T sheets. It was poured into a space formed by sandwiching a frame made of vinyl chloride chimneys with an outer diameter of 5Ia between glass plates, and then immersed in a constant temperature water bath at 70°C for 6 hours and then in a hot air oven VC at 110°C for 2 hours. I made a resin board of Sa4 Ugo. This resin plate was crushed using a crusher to form a powder, which was 90 parts by weight of this powder, 50 parts by weight of methyl methacrylate, and 20 parts by weight of methacrylic acid. f
A thermosetting composition was prepared by mixing part fi and 5 parts by weight of ditertiary butyl peroxide α. This composition was injection molded into a flat plate using an injection molding machine with a mold temperature of 140°C, and then held at a temperature of 140°C for 10 minutes.Then, the mold temperature was raised to 200°C, and After holding at 150°C for 3 minutes, the molded product was peeled from the mold to obtain a transparent thermosetting resin plate. The glass transition point of this resin plate was determined using Pybron DDV111-
Using the Ftll dynamic viscoelasticity measuring device, the frequency was 110H2.
The complex modulus of elasticity (E) is calculated from the peak temperature at t0, which is 172°C.Also, the surface hardness of this plate is relatively high at 4H on the lead cage hardness, and it is resistant to organic solvents such as acetone, toluene, and alcohol. Even in the immersion test, there was no change in appearance and it had excellent chemical resistance.Also, the transmittance of visible light was measured with a spectrophotometer (Hitachi Spectrophotometer) and it was found that the wavelength range was 400 nm to 800 nm. So 9
A complete display of light transmittance of 0 or more.

Examples 2-4 Poly β-methylglycidyl methacrylate.

A thermosetting resin plate was prepared in the same manner as in Example 1, except that the mixing ratio of methyl methacrylate and methacrylic acid was as shown in the table. The glass transition point, pencil hardness, chemical resistance, and visible light transmittance of each resin plate were examined in the same manner as in Example 1, and the ratio results are also shown in the table.

PMGMA: Poly β-methylglycidyl methacrylate powder MMA: Methyl methacrylate, MAA: Methacrylic acid T%: Original transmittance from 400°C to 800nm Chemical resistance ○ No change after immersion in toluene and methanol TBPO Ni-tertiary-butyl peroxide Example 5 50 parts by weight of polymethyl methacrylate pellets (Acrivet VH manufactured by Mitsubishi Dyson Co., Ltd.), 35 parts by weight of β-methylglycidyl methacrylate, 15 parts by weight of methacrylic acid, and 105 parts by weight of di-tert-butyl peroxide. A thermosetting composition was prepared by mixing. This composition was injection molded under the same conditions as in Example 1 to obtain a thermosetting resin plate. The results of evaluation using the same method as in Example 1 were as follows: E'-peak temperature: 160°C, surface hardness: 3H, visible light transmittance: 90.
It is more than enough toluene.

No change in appearance was observed in acetone and methanol immersion tests.

Comparative Example 1 A thermosetting composition was prepared by mixing 50 parts by weight of the poly β-methylglycidyl methacrylate powder used in Example 1, 47 parts of methyl methacrylate, 1 part of 3M methacrylic acid, and 1 part of ditertiary-butyl peroxide α05i. This composition was injection molded under the same conditions as in Example 1, and the molded product was removed after the mold temperature became 100°C or less. The glass transition point is 100℃ and the pencil hardness is 2H.
1. The visible light transmittance was 90% or more. Immersed in acetone, it swells at 9 places and cracks appear on the surface.Comparative Example 2 Polymethyl methacrylate pellet (Acryvet VU manufactured by Mitsubishi Rayon Co., Ltd.) SO parts by weight, methyl methacrylate 40 parts by weight, β-methylglycidyl methacrylate 3 parts by weight 1 part by weight, 7 parts by weight of methacrylic acid, and 0.05 parts by weight of ditertiary-butyl peroxide to prepare a thermosetting composition. This composition was injection molded under the same conditions as in Example 1, and the molded product was taken out after the mold temperature reached 100° C. or lower. This molded product was evaluated in the same manner as in Example 1, and it was found that the glass transition point was 110°C, the lead hardness was H1, and the visible helix transmittance was 0° or higher. Comparative Example 3 85 parts by weight of the polyβ-methylglycidyl methacrylate powder used in Example 1, methyl methacrylate) 10] 1f
I part by weight, 5 parts by weight of methacrylic acid, and 0.05 parts by weight of ditertiary-butyl peroxide to create a thermosetting composition. A curing reaction occurred and the product hardened during mixing.

Comparative Example 4 A thermosetting composition was prepared by mixing 2Qii parts of poly β-methylglycidyl methacrylate powder used in Example 1, 70 parts by weight of methyl methacrylate, 10 parts by weight of methacrylic acid, and ji parts of ditertiary peroxide α05]. Create a friend. This composition has good fluidity at room temperature, and when it is put into an injection molding machine, a large amount of monomer vapor leaks into the outside air, causing problems in the working environment. In addition, heat curing after molding requires about 1 hour at 140°C, which reduces productivity.

〔Effect of the invention〕

The thermosetting composition of the present invention can provide a composition that can form a thermosetting resin with high productivity and excellent transparency.

Claims (1)

[Scope of Claims] 1) Composition in terms of monomers: at least one carboxyl group-containing vinyl monomer (A) 4 to 30% by weight, at least one glycidyl group-containing vinyl monomer (B) 4 ~9
6% by weight and other copolymerizable monomers (C) to 92% by weight, and the monomer contained in the composition is 20% by weight or more and 70% by weight. A thermosetting composition with excellent transparency, characterized in that the transparency is less than %. 2) The thermosetting type with excellent transparency according to claim 1, wherein the carboxyl group-containing vinyl monomer (A) is a monomer selected from methacrylic acid, acrylic acid, itaconic acid, or crotonic acid. Composition. 3) Claim 1, wherein the glycidyl group-containing vinyl monomer (B) is a monomer selected from glycidyl acrylate, glycidyl methacrylate, β-methylglycidyl acrylate, and β-methylglycidyl methacrylate.
A thermosetting composition with excellent transparency as described in 1.