JPH11269237A - Unsaturated polyester resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an unsaturated polyester resin composition which increases the shelf stability of a sheet molding compound(SMC) comprising the unsaturated polyester resin composition and also sufficiently increases the appearance properties such as smoothness, etc., of the surface of a resin molded part. SOLUTION: This composition essentially comprises an unsaturated polyester diluted with vinyl monomers and a tertiary butyl peroxy-2-methylbenzoate as a hardener. Preferably, against 100 pts.wt. unsaturated polyester diluted with vinyl monomers, 1 to 5 pts.wt. tertiary butyl peroxy-2-methylbenzoate which is a hardener is contained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an automobile exterior part,
The present invention relates to an SMC (sheet molding compound) unsaturated polyester resin composition used for wall panels, unit baths, waterproof pans, bathtubs and the like.

[0002]

2. Description of the Related Art Conventionally, an unsaturated polyester resin composition is prepared by adding a low shrinkage agent, a curing agent, a polymerization inhibitor, a filler, a thickener, to an unsaturated polyester diluted with a vinyl monomer such as styrene. A release agent, and further a coloring or the like are mixed as an additive, further impregnated with a reinforcing material, and used as a molding material SMC of a resin molded product. Then, the SMC is placed on a mold, pressed and heated, and manufactured as a resin molded product.

[0003]

As described above, the SMC used for pressurized heat molding has good storage stability of the SMC impregnated with the unsaturated polyester resin composition, and has a high curing speed (molding speed) during molding. Time) and smoothness and glossiness of manufactured resin molded products, especially products that are directly visible and touchable by hand, such as automotive exterior parts, wall panels, unit baths, waterproof pans, bathtubs, etc. Is required to have good appearance characteristics. However, since these conditions are in conflict with each other, the conventional SMC using the unsaturated polyester resin composition has not been able to satisfy all of the requirements even if they can be individually dealt with.

The present invention has been made in view of the above-mentioned problems, and is intended to improve the storage stability of an SMC comprising an unsaturated polyester resin composition and to sufficiently enhance the appearance characteristics of a resin molded product surface. An object is to provide a saturated polyester resin composition.

[0005]

According to the first aspect of the present invention, an unsaturated polyester diluted with a vinyl monomer contains tertiary butyl peroxy-2-methylbenzoate as a curing agent as an essential component. The use of the unsaturated polyester resin composition enhances the storage stability of the SMC to improve the handleability, and also enhances the appearance characteristics such as the smoothness of the surface of the resin molded product.

Further, the present invention relates to a tertiary butyl peroxy-2-methylbenzoate curing agent of 1 to 5 parts by mass per 100 parts by mass of the unsaturated polyester diluted with a vinyl monomer. The use of an unsaturated polyester resin composition containing the compound (1) increases the storage stability of SMC to improve the handleability, and also enhances the appearance characteristics such as the smoothness of the surface of the resin molded product.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The unsaturated polyester resin composition of the present invention comprises an unsaturated polyester diluted with a vinyl monomer as a main component and a tertiary butyl peroxy-2-methylbenzoate as a curing agent. Is contained as an essential component, and other additives are mixed.Other additives include a low shrinkage agent, a polymerization inhibitor, a filler, a thickener,
A release agent, a colorant, and the like are blended and uniformly mixed. The order of mixing these additives is not particularly limited. Then, the unsaturated polyester resin composition is further impregnated with a reinforcing material and used as SMC.

Among the above unsaturated polyester resin compositions, unsaturated polyester is obtained by polycondensing a polyhydric alcohol with an unsaturated polybasic acid or a saturated dibasic acid, and the polyhydric alcohol includes ethylene glycol, Propylene glycol, butanediol, diethylene glycol, dipropylene glycol, triethylene glycol, pentanediol, hexanediol, neopentyl glycol,
Hydrogenated bisphenol A, bisphenol A, glycerin and the like are used. Maleic anhydride, fumaric acid, citraconic acid, itaconic acid, etc. are used for unsaturated polybasic acids, and orthophthalic acid, isophthalic acid, terephthalic acid, adipic acid, tetrahydrophthalic anhydride, sebacine Acid, succinic acid, tetrachlorophthalic anhydride and the like are used.

The vinyl monomer for diluting the unsaturated polyester has a polymerizable double bond,
Styrene, chlorostyrene, divinylbenzene, diallyl phthalate monomer,
Methyl methacrylate, methyl acrylate, vinyl toluene and the like are used.

[0010] To the unsaturated polyester diluted with a vinyl monomer, a low-shrinking agent for preventing shrinkage of a resin molded article at the time of molding is added as an additive. Examples of the low-shrinking agent include polyethylene, polystyrene, and polystyrene. Vinyl acetate, saturated polyester, polyvinyl acetate, styrene-butadiene block copolymer and the like are used.

The unsaturated polyester curing agent diluted with a vinyl monomer includes tertiary (abbreviated as t).
Organic peroxides such as -butylperoxybenzoate, benzoyl peroxide, t-butylperoxyisopropyl carbonate, t-hexylperoxyisopropylcarbonate, t-amylperoxybenzoate and t-hexylperoxybenzoate; Is exemplified. However, with these curing agents, it is difficult to increase the storage stability of the SMC impregnated with the unsaturated polyester resin composition, and even if the storage stability can be increased, the curing speed is reduced. , Inferior in moldability.

In the present invention, t-butyl peroxy-2-methylbenzoate is essentially used as a curing agent, and the curing rate of the SMC impregnated with the unsaturated polyester resin composition is reduced at a specific compounding amount. Without doing so, storage stability can be improved, and surface characteristics such as smoothness and glossiness of the surface of the resin molded product can be improved. The compounding amount is set to 1 to 5 parts by mass of t-butyl peroxy-2-methylbenzoate as a curing agent with respect to 100 parts by mass of the unsaturated polyester diluted with the vinyl monomer, and more preferably 1.5 parts by mass. Add as ~ 3 parts by weight.
If the amount is less than 1 part by mass, the curing speed may be low, and if it exceeds 5 parts by mass, the storage stability may be reduced.

The unsaturated polyester resin composition may further contain, as additives, a polymerization inhibitor, a filler, a thickener, a release agent,
Further, a coloring agent and the like are blended and uniformly mixed. And the polymerization inhibitors include parabenzoquinone, hydroquinone, metadinitrobenzene, paraphenyldiamine,
2,6 di-t-butyl 4-methylphenol or the like is used, and as a filler, calcium carbonate, magnesium silicate,
Thickeners such as aluminum hydroxide include alkaline earth metal oxides or hydroxides such as magnesium oxide, magnesium hydroxide, calcium oxide and calcium hydroxide. Release agents include stearic acid and oleic acid. Pigments, dyes, and the like are used as coloring agents, such as zinc stearate, calcium stearate, and magnesium stearate.

The unsaturated polyester resin composition in which the above-mentioned components are mixed as additives is impregnated with a reinforcing material, aged, and used as an SMC of a molding material. As the reinforcing material, glass fiber, carbon fiber, aramid fiber, cellulose fiber, cotton fiber, or the like is used. When the SMC produced as described above is placed on a mold and subjected to pressure and heat molding, a resin molded product having surface characteristics excellent in smoothness and glossiness can be manufactured. The aging material impregnated with the reinforcing material can be used not only as a sheet-like SMC but also as a bulk-like BMC.

[0015]

EXAMPLES (Preparation of SMC) As shown in Table 1, among the unsaturated polyester resin compositions, an unsaturated polyester diluted with a vinyl monomer, an additive low shrinkage agent, a polymerization inhibitor, Fillers, thickeners, release agents, and reinforcing agents were used at fixed amounts, and among the additives, curing agents were used at different amounts to prepare SMC.

The following materials were used for each component. Among the vinyl monomers, unsaturated polyester diluted with styrene (Polyset PS-9120, manufactured by Hitachi Chemical Co., Ltd., trade name), saturated polyester of low shrinkage agent (Polyset B9201, manufactured by Hitachi Chemical Co., Ltd.) , Trade name), curing agent t-butyl peroxy-2-methylbenzoate (TRIGONOX97-C75, Akzo
Japan Corporation, trade name), t-butyl peroxybenzoate (Kayabutyl B, manufactured by Kayaku Akzo Co., Ltd.)
(Trade name) and t-butyl peroxyisopropyl carbonate (Kayacarbon BIC-75, manufactured by Kayaku Akzo Co., Ltd.).

The polymerization inhibitor parabenzoquinone (P
BQ, manufactured by Seiko Chemical Co., Ltd., trade name), calcium carbonate (S-lite 1200, manufactured by Nitto Powder Chemical Co., Ltd., trade name), magnesium oxide as a thickener (Kyowa Mag # 20, Kyowa Chemical Industry Co., Ltd.) , Trade name), release agent zinc stearate (zinc stearate, Nippon Oil & Fats Co., trade name), reinforcing glass fiber (glass roving # 580, Nitto Boseki Co., trade name) Was.

(Examples 1 to 3) Among the above components, the proportions of the components in which the blending amounts were constant were as follows. 100 parts by mass (as a 40% by mass styrene solution) of an unsaturated polyester diluted with styrene as a vinyl monomer is mixed with 30 parts by mass of a saturated polyester as a low-shrinkage agent (as a 50% by mass styrene solution). 0.1 parts by mass of parabenzoquinone as an inhibitor, 200 parts by mass of calcium carbonate as a filler,
3 parts by mass of zinc stearate as a release agent and 1 part by mass of magnesium oxide as a thickener were blended. These include the curing agent t
-Butyl peroxy-2-methylbenzoate was also blended and impregnated into 120 parts by mass of glass fiber as a reinforcing material.

Of the additives, t-butyl peroxy-2-methylbenzoate, a curing agent having a different blending amount, is used for the unsaturated polyester 1 diluted with a vinyl monomer.
3 parts by mass, 1.5 parts by mass, and 2 parts by mass
The SMC was prepared by blending parts by mass.

(Comparative Examples 1 to 3) Among the above components, the proportions of the components in which the blending amounts were constant were as follows. 100 parts by mass (as a 40% by mass styrene solution) of an unsaturated polyester diluted with styrene as a vinyl monomer is mixed with 30 parts by mass of a saturated polyester as a low-shrinkage agent (as a 50% by mass styrene solution). 0.1 parts by mass of parabenzoquinone as an inhibitor, 200 parts by mass of calcium carbonate as a filler,
3 parts by mass of zinc stearate as a release agent and 1 part by mass of magnesium oxide as a thickener were blended. These include the curing agent t
-Butyl peroxybenzoate or t-butyl peroxyisopropyl carbonate was also blended and impregnated into 120 parts by mass of the reinforcing glass fiber.

Among the additives, t-butyl peroxybenzoate as a curing agent having a different blending amount is an unsaturated polyester 10 diluted with styrene as a vinyl monomer.
SMC was prepared by blending 3 parts by mass or 3 parts by mass or 1.5 parts by mass of t-butyl peroxyisopropyl carbonate with respect to 0 parts by mass.

(Formation of Plate) As shown in Table 1, using the SMCs of Examples 1 to 3 and Comparative Examples 1 to 3,
A plate-like body having a thickness of 0 mm, a width of 300 mm, and a thickness of 2.5 mm was pressed and heated. The pressure and heat molding is performed at a molding pressure of 9.8.
MPa (100 kgf / cm ² ), mold temperature 160 ° C.,
Molding was performed with a molding pressure time set to 40 seconds or 60 seconds.

(Test Method) Table 1 shows the measurement results of the storage stability of the SMCs prepared in Examples 1 to 3 and Comparative Examples 1 to 3 and the smoothness of the plate-like body formed by heating under pressure. . The storage stability of the SMC indicates the storage days in which the SMC can be stored in an atmosphere at 23 ° C. and can be molded. The smoothness of the formed plate-like body is measured by a surface smoothness measuring device (Loria, Ashland, USA) (Manufactured by the company, trade name). The smaller the value, the better the smoothness.

[0024]

[Table 1]

From the results shown in Table 1, in the embodiment of the present invention, S
The storage stability can be increased without reducing the molding pressure time of the MC, and the surface smoothness of the resin molded product is clearly excellent.

[0026]

The unsaturated polyester diluted with a vinyl monomer is added to a tertiary butyl peroxy curing agent as a curing agent.
Since the unsaturated polyester resin composition containing 2-methylbenzoate as an essential component was used, the storage stability of the SMC impregnated with the unsaturated polyester resin composition was increased, the handling property was improved, and the resin was improved. Excellent effects such as smoothness of the surface of a molded article and appearance characteristics can be exhibited.

Claims (2)

[Claims] 1. An unsaturated polyester diluted with a vinyl monomer is added to a tertiary butyl peroxy-curing agent.
An unsaturated polyester resin composition comprising 2-methylbenzoate as an essential component. 2. A curing agent comprising 1 to 5 parts by mass of tertiary butyl peroxy-2-methylbenzoate as a curing agent with respect to 100 parts by mass of an unsaturated polyester diluted with a vinyl monomer. The unsaturated polyester resin composition according to claim 1.