JPH08120168A - Unsaturated polyester resin composition and production of unsaturated polyester resin formed product - Google Patents

Abstract

PURPOSE: To provide an unsaturated polyester resin composition which comprises an unsaturated polyester resin, an inorganic filler, an aliphatic peroxyester type organic peroxide and reinforcing fibers in a specific proportion, thus gives molded products of good quality with reduced discoloration when they are dipped in water by cold compression molding. CONSTITUTION: A composition comprising (A) 100 pts.wt. of unsaturated polyester resin, (B) 50-350 pts.wt. of an inorganic filler and (C) 0.3-5 pts.wt. of an aliphatic peroxyester type organic peroxide having 40-80 deg.C 10 hour half-life temperature such as t-butylperoxy neodecanoate is combined with (D) 2-40wt.%, based on the total weight, of reinforcing fibers, preferably glass fibers to give this composition. As component B, calcium carbonate is preferred with reference to its physical properties and costs, and the molded products of high transparency and design can be given using aluminum hydroxide or glass powder. The component D has usually 1-80mm fiber length.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unsaturated polyester resin composition and a method for producing an unsaturated polyester resin molding, and in particular, for compression molding which makes it possible to obtain a molding having little discoloration when immersed in water. Of the unsaturated polyester resin composition and a method for producing an unsaturated polyester resin molded article by compression molding.

[0002]

2. Description of the Related Art A reinforcing fiber material such as glass fiber is impregnated with a resin composition obtained by adding a filler, a curing agent, a release agent, a pigment, a thickener, etc. to an unsaturated polyester resin to obtain a sheet or a bulk. The unsaturated polyester resin molding material formed in the above is called a sheet molding compound (SMC), a bulk molding compound (BMC), or the like. These SMCs and BMCs are mainly compression-molded and widely used for housing equipment, industrial parts, automobile parts and the like. In addition, residential equipment is often used in a water contact environment such as a bath unit.

These molding materials are often compression molded under heating. However, in compression molding, if an attempt is made to expand applicable products (larger size, higher variety of products), a large molding machine will be required, and expensive die investment will be required. growing.

On the other hand, conventionally, in compression molding, the molding temperature is 130 to 160 ° C. and the compression molding pressure is 80 to 1
A high pressure of 00 kg / cm ² is used. Therefore, it is considered that the cost burden can be reduced if compression molding can be performed at a lower temperature and a lower pressure.

However, if compression molding is attempted at a low temperature, not only the molding time tends to be long, but also the obtained molded product is apt to undergo yellowing or whitening when immersed in water.
In addition, the decrease in viscosity due to heating is reduced, the fluidity is insufficient, and the wall thickness is easily lost.

Further, in order to cure at a higher speed, Japanese Patent Application Laid-Open No. 2-115207 discloses a method of incorporating a salt of a metal such as cobalt as a curing accelerator.
However, with this method, although the molding time can be shortened, discoloration becomes significant when immersed in water.

[0007]

DISCLOSURE OF THE INVENTION The object of the present invention is to make it possible to produce a good molded product with high productivity in compression molding at a low temperature, and yet to prevent a discoloration upon immersion in water. It is an object of the present invention to provide an unsaturated polyester resin composition and a method for producing a molded article, which makes it possible to obtain

[0008]

According to a first aspect of the present invention, 50-350 parts by weight of an inorganic filler is added to 100 parts by weight of an unsaturated polyester resin, and a 10-hour half-life temperature is 40 ° C-80 ° C. An unsaturated polyester resin composition having reinforcing fiber content of 2 to 40 wt% is added to a composition obtained by mixing 0.3 to 5 parts by weight of aliphatic peroxyester-based organic peroxide It is a thing, by which
The above object is achieved.

Further, the invention according to claim 2 is such that 100 parts by weight of the unsaturated polyester resin and 50 to 35 of the inorganic fillers are used.
0 parts by weight and aliphatic peroxyester-based organic peroxide having a 10-hour half-life temperature of 40 ° C to 80 ° C 0.3 to
2 to 40 parts by weight of the reinforcing fiber in the composition containing 5 parts by weight.
Blended so as to be weight% or combined,
A method for producing an unsaturated polyester resin molded product, which comprises compression molding at a molding temperature of 60 ° C to 120 ° C.

The unsaturated polyester resin composition used in the inventions of claims 1 and 2 (hereinafter referred to as the present invention) means an unsaturated polyester resin, and an inorganic filler as an essential component, 10
An aliphatic peroxyester-based organic peroxide having a time half-life temperature of 40 ° C. to 80 ° C., a reinforcing fiber are added, and a mold release agent, a thickener, a pigment, and the like are usually added as other components to form polyethylene. Cover with a release film such as a film to increase the viscosity,
It is a semi-solid product.

The unsaturated polyester resin composition is formed into a sheet or bulk according to the purpose. As the inorganic filler, fine particles of calcium carbonate, aluminum hydroxide, calcium sulfate, glass powder, talc, mica, etc. are used.

Calcium carbonate is preferably used in terms of physical properties and price. Further, aluminum hydroxide or glass powder is preferably used in order to obtain a molded product having higher transparency and design.

The particle size of the inorganic filler is preferably 0.1.
Is about 200 μm. More preferably, 0.5 to 100
μm. If it is less than 0.1 μm, the viscosity of the composition is increased, the reinforcing fibers are not sufficiently impregnated, air is likely to be mixed into the material, and cavities are easily formed in the molded product. on the other hand,
If it is larger than 200 μm, physical properties such as impact strength may deteriorate.

The unsaturated polyester resin 10 may be added either singly or in combination.
It is in the range of 50 to 350 parts by weight with respect to 0 parts by weight.
It is preferably in the range of 60 to 300 parts by weight. When the amount is less than 50 parts by weight, the handleability of the composition before molding is deteriorated. Further, if it is more than 350 parts by weight, the viscosity will be significantly increased, the fluidity at the time of molding processing will be lowered, the impregnability with the reinforcing fiber will be lowered, and it becomes easy to mix air into the material, and the physical properties of the molded product Is reduced.

100 parts by weight of the unsaturated polyester resin means the total amount of the unsaturated polyester polymer component, the polymerizable monomer, and the thermoplastic resin for reducing the shrinkage, which is added if necessary. Is.

The aliphatic peroxyester-based organic peroxide having a 10-hour half-life temperature of 40 ° C. to 80 ° C. as a curing agent is represented by the following structural formula (1) or (2). There are things.

[0017]

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[0018]

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Here, for the sake of convenience, the term "aliphatic compound" includes not only chain hydrocarbon compounds such as alkanes, alkenes and alkynes but also alicyclic hydrocarbon compounds such as cycloalkanes and bicycloalkanes. ,Preferably,
A compound having 1 to 15 carbon atoms is used.

When a curing agent having a 10-hour half-life temperature lower than 40 ° C. is used, the curing rate is increased, but the storage stability of the composition is extremely lowered. Further, the curing rate is too fast, pregel is liable to be generated, and the surface property of the molded product is deteriorated. When a curing agent having a 10-hour half-life temperature higher than 80 ° C. is used, the curing rate is lowered and whitening upon immersion in water is likely to occur. Therefore, the above-mentioned organic peroxide having a 10-hour half-life temperature of 40 to 80 ° C, more preferably 50 to 75 ° C is used.

When an aromatic type curing agent is used,
Yellowing is likely to occur during water immersion, and when a peroxyketal-based curing agent and diacyl peroxide-based curing agent are used, curing does not proceed sufficiently in a short time, and whitening during water immersion is likely to occur. .

When a hydroperoxide type curing agent or a dialkyl peroxide type curing agent is used, the curing rate is slow and the productivity is lowered. When a ketone peroxide-based curing agent is used, storage stability is poor, curing does not proceed sufficiently, and whitening during immersion in water is likely to occur.

The amount of the aliphatic type peroxyester organic peroxide added is 0.3 to 5 parts by weight based on 100 parts by weight of the unsaturated polyester resin. Preferably,
0.5 to 4 parts by weight. More preferably, 0.7-
3 parts by weight. If the amount is less than 0.3 parts by weight, it may take a long time to complete the curing, or the amount of residual monomers may increase, and whitening may easily occur in the water. Also,
If the amount is more than 5 parts by weight, yellowing becomes significant when immersed in water.

More specific examples of the aliphatic peroxyester organic peroxide having a 10-hour half-life temperature of 40 ° C. to 80 ° C. include tertiary butyl peroxy neodecanoate and tertiary butyl peroxide. Oxyneohexanoate, tert-butylperoxypivalate, 2,4,4-trimethylpentylperoxy-2-
Ethyl hexanoate, tertiary amyl peroxy-2-ethyl hexanoate, tertiary butyl peroxy-2-ethyl hexanoate, tertiary butyl peroxyisobutyrate, 1,1,3,3-tetramethyl Butyl peroxy neodecanoate, 1-cyclohexyl-1-methylethyl peroxy neodecanoate, tertiary hexyl peroxy neodecanoate, tertiary hexyl peroxypivalate, 1-
Examples thereof include cyclohexyl-1-methylethylperoxy-2-ethylhexanoate and tertiary hexylperoxy-2-ethylhexanoate.

As the reinforcing fibers, glass fibers, carbon fibers, asbestos fibers, whiskers, organic synthetic fibers, natural fibers and the like are used. Preferably, glass fibers are used in terms of physical properties and price. As the reinforcing fibers, fibers having a constant length or continuous fibers may be used as they are, or mat-shaped or cloth-shaped fibers may be used. For example, in the case of glass fiber, a chopped strand obtained by cutting the strand into a certain length, or a chopped strand mat in which the chopped strand is bonded with a binder to form a mat is used. As a fixed length fiber,
Usually, one having a diameter of 1 to 80 mm is used. If it is shorter than 1 mm, there is no reinforcing effect, and if it is longer than 80 mm, the viscosity increases and the moldability deteriorates. The orientation of the fibers in the saturated polyester resin composition is arbitrary, and random ones, ones arranged in one direction, ones arranged in an X shape, and the like are used.

The reinforcing fiber is mixed in the range of 2 to 40% by weight with respect to the whole unsaturated polyester resin composition containing the reinforcing fiber. It is preferably in the range of 3 to 35% by weight. When the amount is less than 2% by weight, the handling property of the material is deteriorated, and the reinforcing effect is insufficient, so that the molded product is apt to crack or bend. When it is more than 40% by weight, the viscosity is increased and the fluidity is deteriorated.

In the present invention, the unsaturated polyester resin means an unsaturated polyester obtained by polycondensing an unsaturated dibasic acid, a glycol, and optionally a saturated dibasic acid, a polymerizable monomer, and It is a mixture composed of a thermoplastic resin for reducing shrinkage, which is added as necessary.

As the unsaturated dibasic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid and the like are used. Examples of glycols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, bisphenol A, hydrogenated bisphenol A, and bisphenol A ethylene oxide. Adducts, neopentyl glycol and the like are used.

As the saturated dibasic acid, phthalic anhydride, orthophthalic acid, isophthalic acid, terephthalic acid, adipic acid, succinic acid, tetrachlorophthalic acid, het acid and the like are used.

As the polymerizable monomer, styrene, dichlorostyrene, vinyltoluene, vinyl acetate, methacrylic acid, methacrylic acid ester, acrylic acid, acrylic acid ester, diallyl phthalate and the like are used, but styrene is preferably used. To be done.

Usually, the amount of the polymerizable monomer contained in the unsaturated polyester resin is 20 to 60% by weight. Also,
Examples of the thermoplastic resin for reducing shrinkage include polystyrene, polyvinyl acetate, polymethyl methacrylate, polyethylene, poly ε-caprolactone, saturated polyester, polyvinyl chloride, polybutadiene, polystyrene-acrylic acid copolymer, polystyrene- Polyvinyl acetate copolymer, ethylene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, acrylonitrile-styrene copolymer and the like are used.

Further, as the mold release agent which can be used in the unsaturated polyester resin composition of the present invention, metal salts of fatty acids such as zinc stearate and calcium stearate are preferable.

As the thickener, an inorganic thickener and an organic thickener are used. As the inorganic thickener, a metal oxide or metal hydroxide thickener such as magnesium oxide, magnesium hydroxide, calcium oxide, calcium hydroxide, zinc oxide or the like is used. Further, as the organic thickener, a polyfunctional isocyanate compound, an oxazoline compound, an epoxy compound or the like is used.

When an inorganic thickening agent is used, the thickening to obtain a semi-solid state is usually carried out for 5 hours to 2 days at 30 to 50 ° C.
By placing the composition under the temperature conditions of. On the other hand, it is also possible to make the composition semi-solid without using the thickener. For example, using a more crystalline unsaturated polyester using a symmetric monomer such as terephthalic acid or 1,4-butylene glycol, under heating,
There is a method in which a semi-solid unsaturated polyester composition is obtained by impregnating a filler, a reinforcing fiber and the like and cooling at room temperature.

The unsaturated polyester resin composition of the present invention can be formed into either a sheet form or a bulk form. The sheet form molding material is called SMC or TMC and is formed by using a known machine. . For example, using a doctor blade on a release sheet such as polyethylene film,
Apply the unsaturated polyester resin composition to a uniform thickness,
After spreading the reinforcing fibers on the surface, the reinforcing fibers may be sandwiched with the unsaturated polyester resin composition applied to the release sheet prepared in the same manner and impregnated with a roll to form a sheet. The bulk molding material is called BMC and is formed by a mixer such as a kneader.

According to the invention of claim 2, 100 parts by weight of the unsaturated polyester resin and a 10-hour half-life temperature of 40 ° C.
A composition containing 0.3 to 5 parts by weight of an aliphatic peroxyester-based organic peroxide having a temperature of -80 ° C. is added to or combined with reinforcing fibers in an amount of 2 to 40% by weight based on the total weight. And a compression temperature of 60 ° C. to 120 ° C. for compression molding.

The reinforcing fiber may be added when obtaining the unsaturated polyester resin composition, or may be prepared separately from the composition and may be laminated on the composition during compression molding to obtain a molded article. In this case, a preform mat preliminarily shaped in the shape of the molded product, or a sheet-shaped reinforcing fiber base material such as mat or cloth is used.

The above unsaturated polyester resin composition has a composition of 6
The required amount is put into a mold heated at 0 to 120 ° C., and compression molding is performed. The temperature is preferably 80 to 110 ° C. 6
If the temperature is lower than 0 ° C, the molding time will be significantly increased and the fluidity at the time of molding will be lowered. On the other hand, if the temperature is higher than 120 ° C., pregel is liable to be generated during the molding process and the surface property of the molded product is deteriorated. Also, low cost molds cannot be used.

Although compression molding can be performed at a molding pressure of ² to 150 kg / cm ² , it is preferably ² to 30 kg / cm ² in order to reduce equipment investment such as a mold and a press. If it is less than 2 kg / cm ² , the fluidity is lowered, so that it is difficult to obtain a desired molded article, and it is impossible to extrude or reduce the voids, so that the surface properties and the physical properties are largely lowered. If it is larger than 30 kg / cm ² , the above-mentioned capital investment burden cannot be reduced.

Preferred examples of the invention of claim 1 are shown below. An inorganic filler having an average particle size of 0.5 to 20 μm based on 100 parts by weight of the unsaturated polyester resin composition.
60 to 300 parts by weight of calcium carbonate, or 60 to 300 aluminum hydroxide having an average particle size of 0.5 to 30 μm
Add parts by weight or 60 to 300 parts by weight of glass powder having an average particle size of 0.5 to 20 μm.

When the above fillers are used in combination, the total amount is 60 to 300 parts by weight. To the unsaturated polyester composition consisting of these compositions, 1
0.5-4.0 parts by weight of aliphatic peroxyester organic peroxide having a 0-hour half-life temperature of 50-75 ° C., 2-10 parts by weight of zinc stearate as a release agent, and oxidation as a thickening agent 0.2 to 3 parts by weight of magnesium is mixed, and the reinforcing fibers are added to the composition in an amount of 3 to 35% by weight based on the total amount of the composition by using an SMC or BMC manufacturing apparatus.

As a preferred example of the invention of claim 2, the material of the preferred example of claim 1 is used, and the material is placed in a mold heated to 80 to 110 ° C.,
A method in which the mold is closed and compression molding is performed at a pressure of 5 to 20 kg / cm ² can be mentioned.

[0043]

[Function] 0.3 to 5 parts by weight of an aliphatic peroxyester-based organic peroxide having a 10-hour half-life temperature of 40 to 80 ° C. and 50 to 350 parts of an inorganic filler are used with respect to 100 parts by weight of an unsaturated polyester resin. When an unsaturated polyester resin composition having a reinforcing fiber content of 2 to 40% by weight is compression-molded at a low temperature, reinforcing radicals are relatively quickly generated and radicals are generated. It acts efficiently on double bonds in the monomer and polyester. Therefore, it is possible to obtain a complete curing degree in a short time, so that the productivity of compression molding can be improved, and there is no whitening or yellowing even in an aqueous environment, and it is possible to obtain a molded product that can be sufficiently used. it can. Further, in the present invention, since an aromatic type curing agent is not used, it is considered that a molded product which does not yellow even in an aqueous environment or a light environment can be obtained.

[0044]

EXAMPLES Non-limiting examples of the present invention will be described below. (Example) 100 parts by weight of an unsaturated polyester resin obtained by dissolving an unsaturated polyester containing isophthalic acid, maleic acid, and propylene glycol as main components and polystyrene in a styrene monomer is used in an amount of 1 part by weight of carbonic acid as shown in Table 1. Calcium (average particle size 2 μm), a curing agent of the following types, a release agent (zinc stearate) 3 parts by weight, and a thickener (magnesium oxide) 0.8 parts by weight are added, and an inhibitor is further added. A composition prepared by mixing 0.035 parts by weight of (hydroquinone) with 1 inch of chopped strand (glass fiber manufactured by Asahi Fiber Glass Co., Ltd., trade name: ERAF1
1) was impregnated and covered with a polyethylene film to obtain SMC. The obtained SMC was aged at 40 ° C. for 1 day.

The composition and glass fiber content of the SMC are shown in Table 1. The following were used as the curing agent. A: tertiary hexyl peroxy-2-ethylhexanoate 1.5 parts by weight (10-hour half-life temperature = 69.9 ° C., aliphatic peroxyester-based organic peroxide) B; 2, 4, 4 -Trimethylpentylperoxy-2-ethylhexanoate 1.9 parts by weight (10-hour half-life temperature = 64 ° C, aliphatic peroxyester-based organic peroxide) C; Tertiary butylperoxy neohexanoate 1.5 parts by weight (10-hour half-life temperature = 54 ° C., aliphatic type peroxyester-based organic peroxide) Using the above SMC, a flat plate (270 mm × 150 mm × thickness 4 mm) was prepared using a 300-ton press. It was molded with a mold at a molding pressure of 10 kgf / cm ² . Table 1 shows the pressing time and the mold temperature. The charge of the SMC was placed in the corner on the short side of the flat plate mold, and the charge area ratio was about 11%.

Evaluation Moldability was evaluated according to the following criteria. ○: Good ×: Occurrence of flesh loss, nest, white streak pattern, etc.

As a water immersion test, the molded article was immersed in hot water at 80 ° C. for 500 hours on one side and then the surface was observed to evaluate the degree of whitening and the degree of yellowing according to the following criteria. ○: No change △: Color change is recognizable ×: Significant color change is recognizable

Comparative Example In addition to A and B as a curing agent,
The following curing agents DG were used. D: Cumyl peroxy octoate 1.4 parts by weight (10-hour half-life temperature = 65.1 ° C., aromatic peroxy ester-based organic peroxide) E: Cumyl peroxy neodecanoate 1.5 parts by weight (10-hour half-life temperature = 36.5 ° C., aromatic peroxyester-based organic peroxide) F; 1,1-bis (tert-butylperoxy) -3,5,5-trimethylcyclohexane 1. 4 parts by weight (10-hour half-life temperature = 90 ° C., aliphatic peroxyketal-based organic peroxide) G; succinic acid peroxide 1.2 parts by weight (10-hour half-life temperature = 65.9 ° C., fat Group-type diacyl peroxide organic peroxides)

SMC was blended and evaluated in the same manner as in Example except that the above curing agent was used. For Comparative Example 5, the amount of curing agent (A) was 5.5 parts by weight. Further, in Comparative Example 7, the amount of the curing agent (A) was 0.
2 parts by weight. In Comparative Example 7, curing agent B was used and pressed for 20 minutes, but curing was incomplete and a molded product could not be obtained.

[0050]

[Table 1]

[0051]

[Table 2]

[0052]

According to the invention of claim 1, with respect to 100 parts by weight of the unsaturated polyester resin, the 10-hour half-life temperature is 40 to 40.
Reinforcing fibers are added to a composition containing 0.3 to 5 parts by weight of an aliphatic peroxyester-based organic peroxide at 80 ° C. and 50 to 350 parts by weight of an inorganic filler to obtain a reinforcing fiber content of 2
Since the unsaturated polyester resin composition is -40% by weight, a good molded product can be produced with high productivity even when compression molding is performed at a low temperature. Moreover, it is possible to obtain a durable and high-quality molded product in which whitening and yellowing hardly occur even in a water environment.

Furthermore, since the molding can be performed at low temperature and low pressure, the capital investment for the mold and the like can be reduced, and the compression molding method such as SMC can be applied to the larger molded products and the multi-medium-volume products. The range of application of the molding method using, for example, can be expanded.

Further, in the invention described in claim 2, in the state where the reinforcing fiber is blended or combined with the above-mentioned specific unsaturated polyester resin composition in the above-mentioned specific ratio,
Molding is performed at a relatively low temperature of 120 ° C. Therefore, the cost of compression molding can be reduced, and similarly to the first aspect of the invention, it is possible to stably supply a molded product that is unlikely to cause coloration or yellowing when immersed in water.

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Claims (2)

[Claims] 1. An unsaturated polyester resin of 100 parts by weight, an inorganic filler of 50 to 350 parts by weight, and an aliphatic peroxyester-based organic peroxide having a 10-hour half-life temperature of 40 to 80 ° C. An unsaturated polyester resin composition comprising a composition containing 3 to 5 parts by weight of reinforcing fibers, and the reinforcing fibers being contained in a proportion of 2 to 40% by weight based on the whole composition. 2. 100 parts by weight of an unsaturated polyester resin, 50 to 350 parts by weight of an inorganic filler, and an aliphatic peroxyester-based organic peroxide having a 10-hour half-life temperature of 40 to 80 ° C. The composition containing 3 to 5 parts by weight of the reinforcing fibers is blended or combined so as to be 2 to 40% by weight of the whole, and the molding temperature is 60
A method for producing an unsaturated polyester resin molded article, which comprises compression molding at a temperature of from ℃ to 120 ℃.