JPH08333426A - Thermosetting molding material and method for molding the same - Google Patents

Abstract

PURPOSE: To obtain a thermosetting molding material which can give a molding excellent in surface smoothness, cracking resistance and boiling resistance by mixing a resin component comprising a (meth)acrylate oligomer, an unsaturated polyester and a polymerizable unsaturated monomer with an inorganic filler and a curing agent. CONSTITUTION: A molding material comprising a resin component (the total of the components (a), (b) and (c) is 100wt.%) comprising 20-60wt.% (meth) acrylate oligomer (a) having at least two (meth)acryloyl groups and a number- average molecular weight of 300-3,000, 10-50wt.% unsaturated polyester (b) obtained by reacting a glycol component (e.g. ethylene glycol) with an acid component containing an α,β-unsaturated dicarboxylic acid and/or its acid anhydride (e.g. maleic anhydride) and 20-40wt.% polymerizable unsaturated monomer (c) (e.g. styrene), an inorganic filler (e.g. aluminum hydroxide) and a curing agent (e.g. organic peroxide) is molded at 120-150 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting molding material capable of producing a molding having excellent surface smoothness, crack resistance and boiling resistance, and a molding method thereof.

[0002]

2. Description of the Related Art Unsaturated polyester resin is a thermosetting FR
It is widely used as a resin for P molding materials. The unsaturated polyester is synthesized by subjecting a polyhydric alcohol, an α, β-unsaturated dicarboxylic acid and / or an acid anhydride thereof as essential components to an esterification reaction with a saturated polybasic acid and / or an acid anhydride thereof. Is a polymer having an ester bond and an unsaturated double bond in the main chain, which is usually
A resin dissolved in a polymerizable unsaturated monomer such as styrene is called "unsaturated polyester resin", and is provided as a resin for thermosetting molding material.

A so-called B is obtained by kneading this unsaturated polyester resin together with an inorganic filler and a curing agent to form a lump.
A molding material called MC (bulk molding compound), which is molded into a final product by various molding methods. Among them, compression molding is a simple molding method in which BMC material is put in a mold and pressed under heating, but molding with poor smoothness of the surface of the molded product or cracks in the molded product. There were occasions when defects occurred.
In addition, the boiling resistance of the obtained product is not always satisfactory, and there is a gap between the refractive index of the unsaturated polyester resin and the refractive index of aluminum hydroxide used as a filler, resulting in poor transparency. There was also a practical problem of becoming.

[0004]

Therefore, in the present invention, a thermosetting molding material and a thermosetting molding material capable of producing a molding having good surface properties, hardly cracking during molding, and having little boiling deterioration are obtained. The object is to provide an optimum molding method.

[0005]

According to the present invention, a thermosetting molding material comprises (I): a resin component comprising the following (a), (b) and (c), and (a) at least one molecule. (Meth) acrylate oligomer having 2 (meth) acryloyl groups and a number average molecular weight of 300 to 3000: 20 to 60% by weight (b) glycol component, α, β-unsaturated dicarboxylic acid and / or Unsaturated polyester obtained by reacting the acid component containing the acid anhydride: 10 to 50% by weight (c) Polymerizable unsaturated monomer: 20 to 40% by weight [where (a), (b), The total of (c) is 100% by weight] (II): Inorganic filler (III): Hardener The molding method of the present invention has the gist of molding the thermosetting molding material at 120 to 150 ° C.

[0006]

The present inventors have investigated the cause of deterioration of the surface properties and boiling characteristics of the molded product, and made the resin component mixed in a specific ratio.
It has been found that the above problems can be solved only when (I) is used as the main component of the thermosetting molding material, and the present invention has been achieved. Hereinafter, the present invention will be described in detail.

The resin component (I) which is the main component of the thermosetting molding material of the present invention comprises (a) a (meth) acrylate oligomer, (b) an unsaturated polyester and (c) a polymerizable unsaturated monomer. It is a mixture of three components.

The (meth) acrylate oligomer (a) is an oligomer having a number average molecular weight of 300 to 3000 and having at least two (meth) acryloyl groups in one molecule. By using an oligomer having a molecular weight within this range, it is possible to obtain a high-performance molded product which has good surface properties, is less likely to be cracked during molding, and is less deteriorated by boiling. An oligomer having a number average molecular weight of more than 3000 has too high a viscosity, resulting in poor workability when kneading with the unsaturated polyester as the component (b) or the polymerizable unsaturated monomer as the component (c). On the contrary, when the number average molecular weight is less than 300, improvement in surface properties and boiling characteristics cannot be observed, which is not preferable. As the molecular weight, the number average molecular weight by GPC was used.

As a kind of the (meth) acrylate oligomer, an epoxy (meth) acryloyl group is introduced by reacting two or more epoxy groups in an epoxy resin with an unsaturated carboxylic acid such as (meth) acrylic acid. ) Acrylate oligomer; urethane (meth) acrylate oligomer in which two or more isocyanate groups in the polyisocyanate compound are reacted with (meth) acrylic acid having a hydroxyl group to introduce a (meth) acryloyl group; A polyester (meth) acrylate oligomer obtained by reacting an unsaturated carboxylic acid such as (meth) acrylic acid on the molecular end or side chain of polyester; polyalkylene oxide and (meth)
Polyether (meth) acrylate which is a reaction product of unsaturated carboxylic acid such as acrylic acid; polyhydric alcohol which is a reaction product of polyhydric alcohol such as pentaerythritol and unsaturated carboxylic acid such as (meth) acrylic acid ( (Meth) acrylate; spiroacetal (meth) acrylate obtained by adding an unsaturated carboxylic acid such as (meth) acrylic acid having a hydroxyl group to a spiroacetal compound such as diarylidene pentaerythritol.

Of these, epoxy (meth) acrylate oligomers, which are excellent in compatibility with unsaturated polyester and curing characteristics, are preferably used. Epoxy (meth) acrylate oligomer is bisphenol A
Type, bisphenol F type, phenol or cresol novolac type, alicyclic type, glycidyl ester type, brominated glycidyl ether type, glycidyl amine type epoxy resin, and unsaturated carboxylic acid such as (meth) acrylic acid and crotonic acid Can be obtained by reacting at about 80 to 120 ° C. for about 8 to 15 hours in the presence of an esterification catalyst such as a tertiary amine so that the epoxy group and the carboxyl group become equivalent.

The unsaturated polyester which is the component (b) is
It is obtained by reacting a glycol component with an acid component containing an α, β-unsaturated dicarboxylic acid and / or its acid anhydride. As the glycol component, ethylene glycol, 1,2- or 1,3-propylene glycol, 1,3- or 1,4-butanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, 1,5-Pentanediol, 1,6-hexanediol, bisphenol A, hydrogenated bisphenol A and the like can be mentioned, and one kind or two or more kinds can be used.

As the acid component, α, β-unsaturated dicarboxylic acid such as maleic anhydride, fumaric acid, itaconic acid and citraconic acid (hereinafter simply referred to as unsaturated dicarboxylic acid) and / or its acid anhydride is essential. Used in addition to these acid components, aromatic saturated dicarboxylic acids such as orthophthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride and / or acid anhydrides thereof, Oxalic acid,
Aliphatic or alicyclic saturated dicarboxylic acids such as malonic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, glutaric acid, and hexahydrophthalic anhydride can be used.

The unsaturated polyester can be obtained by reacting the glycol component and the acid component at 150 to 250 ° C. by a known method such as direct esterification reaction or transesterification reaction. An unsaturated polyester resin further reacted with glycidyl methacrylate or the like can also be used.

The polymerizable unsaturated monomer as the component (c) is preferably a monomer which can be copolymerized with the above unsaturated polyester and has excellent compatibility. Specifically, styrene, α-methylstyrene, α-chlorostyrene, vinyltoluene, divinylbenzene, diallyl phthalate,
Aromatic vinyl compounds such as diallylbenzene phosphonate; Vinyl esters such as vinyl acetate and vinyl adipate; Methyl (meth) acrylate, ethyl (meth) acrylate, octyl (meth) acrylate, di (meth)
Examples thereof include (meth) acrylates such as acryloyloxyethyl, and these monomers may be used alone or in combination of two or more. Of these, styrene is preferable in terms of compatibility and polymerization reactivity.

The above (a), which constitutes the resin component of the present invention,
The blending amounts of the three components (b) and (c) are (a): 20 to 6
0% by weight, (b): 10 to 50% by weight, (c): 20 to
It is 40% by weight. However, the total of the three components is 100% by weight.
And When the amount of the oligomer (a) is less than 20% by weight, crack resistance during molding and boiling deterioration of a molded product are remarkable. However, if the oligomer is used in an amount of more than 60% by weight, the viscosity of the molding material becomes too low and the appearance and gloss of the molded product are deteriorated and waviness may occur, which is not preferable.
When the unsaturated polyester of (b) is less than 10% by weight, when the amount of the monomer of (c) is increased, appearance defects and cracks at the time of molding are remarkable, so that the oligomer amount of (a) must be increased. The viscosity of the molding material becomes low and the appearance of the molded product deteriorates. When the unsaturated polyester is used in an amount of more than 50% by weight, the kneading is difficult when the amount of the monomer (c) is small, and the amount of the oligomer is reduced as a result when the amount of the monomer (c) is large. However, crack resistance during molding and boiling deterioration of a molded product occur, which is not preferable. (C)
When the amount of the monomer is less than 20% by weight, the viscosity of the molding material becomes too high and the kneading is difficult. However, if it is used in an amount of more than 40% by weight, the surface properties are poor and only a molded product having poor boiling resistance can be obtained, which is not preferable.

The molding material of the present invention contains an inorganic filler as an essential component together with the above resin component. Known inorganic powders and fibers can be used as the inorganic filler. Specific examples of the inorganic powder include aluminum hydroxide, calcium carbonate, barium sulfate, silica, mica, talc, glass powder, clay, titanium dioxide, and the like, and as the inorganic fibers, glass fibers, boron fibers, carbon fibers, Examples thereof include metal fibers, ceramic fibers such as silicon carbide, alumina, and asbestos. Whiskers can also be used. One or more kinds of these inorganic fillers can be used, and powder and fiber may be used in combination. The size of the powder is not particularly limited. The length and thickness of the fibers are, for example, 0.1 to 50 mm and 2.5 to 20 μm for glass fibers.
However, this is not particularly limited, and can be appropriately changed according to the size of the molded product, the desired strength, and the like.

The blending amount of the inorganic filler is the resin component 10 mentioned above.
20 to 500 parts by weight is preferable with respect to 0 parts by weight. Two
When the amount is less than 0 parts by weight, the surface condition of the obtained molded product is deteriorated and cracks are easily generated. If it exceeds 500 parts by weight, it may be difficult to knead with the resin component, a uniform mixture may not be obtained, and the transparency of the molded product may deteriorate and the surface condition may deteriorate. A more preferable blending amount is 50 to 400 parts by weight. Along with these inorganic fillers, organic fibers such as aramid fibers, high-strength polyethylene fibers, polyarylate fibers, polyester fibers, and polyvinyl alcohol fibers (vinylon) may be used together as long as they are about 10% of the inorganic fillers.

The molding material of the present invention contains a curing agent for curing the resin component. As the curing agent, organic peroxides and azo compounds are preferably used. Specific examples include t-butylperoxyisopropyl carbonate, benzoyl peroxide, dicumyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, t-butyl peroxybenzoate, parachlorobenzoyl peroxide, lauroyl peroxide. , Organic peroxides such as t-butyl peroxyoctoate, and azo compounds such as azobisisobutyronitrile. The preferable amount of the curing agent used is 0.05 to 5 parts by weight with respect to 100 parts by weight of the resin component.

When the organic peroxide is used as a curing agent, a known curing accelerator such as metallic soaps such as Co, V and Mn and tertiary amines can be used together. Further, the molding material of the present invention can be cured by using a photopolymerization initiator as a curing agent and irradiating with actinic rays such as ultraviolet rays and electron beams.

In the molding material of the present invention, in addition to the above essential components, a release agent such as calcium stearate, zinc stearate, stearic acid, a low shrinkage agent such as a thermoplastic resin, a plasticizer, a lubricant, a flame retardant, Known additives such as pigments, antioxidants, ultraviolet absorbers and antistatic agents may be added.

The molding material of the present invention comprises a stirring mixer such as a Henschel mixer, a Banbury mixer, a kneader, and the like.
It can be obtained by mixing with a kneading machine such as a twin-screw extruder until it becomes uniform. The material obtained is usually shaped after aging.

To mold the molding material of the present invention,
Put the molding material in the mold heated to 170 ℃,
It is preferable to employ a method of performing heat and pressure molding at a pressure of 150 kg / cm @ 2 for 1 to 30 minutes. In particular, in the case of the molding material of the present invention, it was found that when the heating conditions of 120 to 150 ° C. are selected, excellent surface smoothness and boiling resistance are obtained. The molding conditions can be appropriately changed according to the size of the mold, the thickness and shape of the molded product, the resin composition, and the like. In addition to the molding conditions described above, it is also possible to mold under a commonly used reduced pressure. Is.

[0023]

The present invention will be described in more detail with reference to the following examples, but the following examples do not limit the present invention.
All modifications and implementations that do not depart from the spirit of the description below are included in the technical scope of the present invention. In the examples below,
"Parts" and "%" mean "parts by weight" and "% by weight", respectively.

Reference Example 1 (Synthesis of Epoxy Acrylate Oligomer A) Araldite GY-250 (Bisphenol A type epoxy resin manufactured by Ciba Geigy: epoxy equivalent 180 to 19)
0), 362 parts, hydroquinone, 0.1 part, triethylamine, 2.0 parts, and acrylic acid, 144 parts were charged into a reaction vessel, and the reaction was carried out at 90 to 100 ° C. for 10 hours while introducing air. The acid value of the obtained epoxy acrylate oligomer A is 4.0, and the number average molecular weight is 5 according to GPC.
It was 00.

Reference Example 2 (Synthesis of Epoxy Acrylate Oligomer B) Araldite 6084 (Bisphenol A type epoxy resin manufactured by Ciba Geigy: epoxy equivalent 900-1000)
855 parts and Araldite 7097 (bisphenol A type epoxy resin manufactured by Ciba Geigy: epoxy equivalent 165
0-2000) 2000 parts, hydroquinone 0.1 part,
2.0 parts of triethylamine, 144 parts of acrylic acid, and 1000 parts of styrene were charged into a reaction vessel, and the reaction was carried out at 90 to 100 ° C. for 10 hours while introducing air. Obtained epoxy acrylate oligomer B (25% styrene
The acid value of the contained styrene solution) was 4.7, and the number average molecular weight was 2,900 according to GPC.

Reference Example 3 (Synthesis of Comparative Epoxy Acrylate Oligomer C) 3640 parts of Araldite 7097, 0.1 part of hydroquinone, 2.0 parts of triethylamine, 14 parts of acrylic acid
4 parts and 1260 parts of styrene were charged into a reaction vessel, and the reaction was carried out at 90 to 100 ° C. for 10 hours while introducing air.
The obtained epoxy acrylate oligomer C (styrene solution containing 25% styrene) had an acid value of 4.8 and a number average molecular weight of 3,600 according to GPC.

Examples 1 to 5 and Comparative Examples 1 to 4 First, the epoxy acrylate A synthesized in Reference Example 1 was used, and the compounding amounts of the resin components were changed as shown in Table 1,
The moldability and boiling property were evaluated. The unsaturated polyester used was one having an acid value of 25 and a molecular weight of 2000, which was obtained by condensation reaction of 1 mol of maleic anhydride, 0.3 mol of hydrogenated bisphenol A and 0.75 mol of propylene glycol. Styrene was used as the polymerizable monomer. As an inorganic filler, fine powder aluminum hydroxide H-320 (manufactured by Showa Denko KK) having an average particle size of 10 μm and a length of 3 m
m, and a glass fiber having a diameter of 13 μm was used. Molding conditions include molding temperature of 130 ° C and molding pressure of 100 kg / cm2.
For 10 minutes, thickness 10 mm, rising 10 cm,
A box-formed product having a length of 28 cm and a width of 37 cm was prepared.

The gloss, wavy state, dents, and whitening of the molded product were comprehensively judged by visual inspection, and very good ones were marked with ⊚, good ones with ○, slightly inferior ones, and considerably poor ones with x. did. The boiling property is that the molded product is
It is the result of a visual evaluation of the degree of whitening and the presence or absence of blisters / cracks after immersion for 00 hours, and evaluation based on the same criteria as the moldability. The results are also shown in Table 1.

[0029]

[Table 1]

From Table 1, it is apparent that Examples 1 to 5 of the present invention are excellent in both moldability and boiling property. On the other hand, Comparative Example 1 in which the amount of the oligomer used is small has inferior cracking and boiling properties during molding. In Comparative Example 2 in which the amount of the oligomer is too large, the moldability is poor. In Comparative Example 3, since the amount of styrene was less than that of the unsaturated polyester, it was difficult to knead, and the molded product was insufficiently cured, and the boiling property was slightly inferior. In Comparative Example 4, since the amount of unsaturated polyester is small and the amount of styrene is too large, it is considered that the surface properties of the molded product deteriorated due to the shrinkage of styrene.

Examples 6 to 7 and Comparative Examples 5 to 6 Using a styrene solution of the epoxy acrylate oligomer B having a molecular weight of 2900 synthesized in Reference Example 2 and a styrene solution of the comparative oligomer C having a molecular weight of 3600 synthesized in Reference Example 3 were used. A molding material having the composition shown in Table 2 was prepared.
The description of the oligomer amount in the table is the amount of the oligomer in the styrene solution, and the amount of styrene is the sum of the styrene in the styrene solution of the oligomer and the amount of styrene added further. The obtained molding material was molded in the same manner as in Example 1 and evaluated. Workability is an evaluation of workability during kneading. The results are shown in Table 2.

[0032]

[Table 2]

In Example 6, good results were obtained in all of workability, moldability and boiling property. High molecular weight oligomer B
In Example 7 using 60% by weight of (styrene solution), the viscosity was high, and thus the workability was slightly inferior, but the moldability and boiling property were excellent. Since the oligomer C (styrene solution) used in Comparative Examples 5 and 6 had a higher viscosity, the workability was poor and only molded products having poor moldability were obtained.

[0034]

EFFECTS OF THE INVENTION The present invention is constituted as described above and, since an oligomer having a specific molecular weight is used, a molding material excellent in molding workability can be provided. A molded product obtained from the molding material of the present invention has excellent surface smoothness and high performance without boiling deterioration. Especially 12
A molded product with the best performance is obtained when molded at 0 to 150 ° C. The molded product obtained by the present invention is useful for various products such as bathtubs, kitchen counters, and waterproof plates.

Claims (2)

[Claims] 1. (I): a resin component comprising the following (a), (b) and (c), and (a) having at least two (meth) acryloyl groups in one molecule and having a number average molecular weight: (Meth) acrylate oligomer having a content of 300 to 3000: 20 to 60% by weight (b) A glycol component, which is obtained by reacting an acid component containing an α, β-unsaturated dicarboxylic acid and / or its acid anhydride. Saturated polyester: 10 to 50% by weight (c) Polymerizable unsaturated monomer: 20 to 40% by weight [however, the sum of (a), (b) and (c) is 100% by weight] (II) : Inorganic filler (III): Hardening agent, thermosetting molding material. 2. The thermosetting molding material according to claim 1
A method for molding a thermosetting molding material, which comprises molding at a molding temperature of 20 to 150 ° C.