JP2001115000A - Unsaturated polyester resin composition, sheet molding compound, and molding made from the compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an unsaturated polyester resin composition that can give moldings resistant to surface crack upon impact, a sheet molding compound, and a molding prepared therefrom. SOLUTION: Provided are an unsaturated polyester resin composition essentially consisting of an unsaturated polyester resin, a polymerizable monomer, a thermoplastic resin, an inorganic filler, and a silicone rubber; a sheet molding compound obtained from the composition; and a molding obtained by thermoforming the compound under pressure.

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, a sheet molding compound, and a molded article using the same, which are useful for producing large containers such as a panel-assembled water tank and a septic tank.

[0002]

2. Description of the Related Art Unsaturated polyester resin compositions are prepared by adding, as additives, a low-shrinking agent, a curing agent, a polymerization inhibitor, a filler, a thickener, to an unsaturated polyester diluted with a polymerizable monomer.
It contains a template, a colorant, and the like. This unsaturated polyester resin composition further comprises two or more glass fibers of the sheet molding compound.
It is impregnated with a reinforcing material containing 5 to 35% by mass and used as a sheet molding compound. Then, the sheet molding compound is placed on a mold and pressurized and heat-molded, and is manufactured as a sheet molding compound molded article such as a panel-assembled water tank and a septic tank.

[0003]

The sheet molding compound molded product formed by pressurizing and heating as described above, especially a large molded product such as a panel-assembled water storage tank or a septic tank, is installed and used above or below the ground. You. However, the above-mentioned SMC molded article has a disadvantage that cracks are more likely to be generated on the surface due to an impact during assembling, transporting or use as compared with dicyclopentadiene or thermoplastic resin molded article. For this reason, the production method conversion to stainless steel in the panel-assembled water tank and dicyclopentadiene resin in the septic tank is progressing, and the use of SMC is decreasing.

The present invention has been made in view of the above problems, and provides an unsaturated polyester resin composition, a sheet molding compound, and a molded article using the same, in which cracks are not generated on the surface of the molded article by impact. The purpose is to:

[0005]

The present invention relates to the following. (1) An unsaturated polyester resin composition comprising, as essential components, an unsaturated polyester resin, a polymerizable monomer, a thermoplastic resin, an inorganic filler, and silicone rubber. (2) 100 to 200 parts by mass of inorganic filler and 3 to 3 parts of silicone rubber, based on 100 parts by mass of unsaturated polyester resin, polymerizable monomer, polymerizable monomer and thermoplastic resin in total.
Item 4. The unsaturated polyester resin composition according to item 1, containing 40 parts by mass. (3) A sheet molding compound containing 15 to 42% by mass of glass fibers in a sheet molding compound obtained by using the unsaturated polyester resin composition according to item (1) or (2). (4) A sheet molding compound molded product obtained by pressurizing and heating using the sheet molding compound described in (3).

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The unsaturated polyester resin composition of the present invention is obtained by reacting a polybasic acid component containing an α, β-unsaturated polybasic acid or its anhydride as an essential component with a polyhydric alcohol. It comprises an unsaturated polyester resin and a polymerizable monomer. A fiber reinforced molding material can be obtained by further mixing a low shrinkage agent, a curing agent and a fiber reinforcing material with the unsaturated polyester resin composition. This fiber-reinforced molding material can be used as a sheet-like molding material formed in a sheet shape.

In the present invention, the α, β-unsaturated polybasic acid or anhydride thereof, which is a raw material for the synthesis of unsaturated polyester resin, includes, for example, α, β-unsaturated dibasic acid or anhydride thereof, for example, Maleic acid, fumaric acid, itaconic acid,
Examples thereof include citraconic acid, maleic anhydride, and anhydrides thereof. These may be used in combination of two or more. Examples of the polybasic acid component include α, β-unsaturated polybasic acid or its anhydride, and saturated polybasic acid in order to control the concentration of unsaturated groups and to impart properties such as flexibility and heat resistance. It is preferable to use a basic acid or its anhydride in combination. At this time, α, β
-The unsaturated polybasic acid or its anhydride is preferably at least 40 mol% of the polybasic acid component. α, β
-When the content of the unsaturated polybasic acid or its anhydride is less than 40 mol%, the strength of the obtained molded article tends to gradually decrease. For this reason, the content of the α, β-unsaturated polybasic acid or its anhydride is more preferably 45 to 80 mol%, and more preferably 5 to 80 mol%.
It is particularly preferred that it is 0 to 70 mol%.

The saturated polybasic acids or anhydrides to be used in combination include phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, 3,6-endomethylenetetrahydrophthalic anhydride, Hexahydrophthalic acid, hexahydrophthalic anhydride, glutaric acid, adipic acid, sebacic acid, trimellitic acid, trimellitic anhydride, pyromellitic acid, dimer acid, succinic acid, azelaic acid, rosin-maleic acid adducts, etc. Can be These may be used in combination of two or more.

Polyhydric alcohols, which are another raw material for the synthesis of unsaturated polyester resins, include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol,
6-hexanediol, neopentyl glycol, 1,
Examples thereof include dihydric alcohols such as 4-cyclohexanediol and hydrogenated bisphenol A, trihydric alcohols such as glycerin and trimethylolpropane, and tetrahydric alcohols such as pentaerythritol. These may be used in combination of two or more.

The polybasic acid component and the polyhydric alcohol are preferably used in an equivalence ratio of 1 to 1.3 when the polybasic acid component is set to 1;
More preferably, it is used in the range of 1.05 to 1.05. When the polyhydric alcohol decreases, the molecular weight of the resulting unsaturated polyester resin tends to decrease, and when the polyhydric alcohol increases, the acid value decreases and the progress of thickening by the thickener tends to be slow.

As a method for producing the unsaturated polyester resin, a conventionally known method can be used. For example,
Polycondensation reaction with polybasic acid component and polyhydric alcohol component,
The reaction proceeds while removing condensed water generated when both components react. The removal of the condensed water out of the system is preferably carried out by natural distillation or vacuum distillation by passing an inert gas. In order to promote the distillation of condensed water, a solvent such as toluene or xylene can be added to the system as an azeotropic component. The progress of the reaction can be generally known by measuring the amount of distillate generated by the reaction, quantifying the functional group at the end, measuring the viscosity of the reaction system, and the like. The reaction temperature is preferably 150 ° C. or higher, and the reaction is preferably performed while passing an inert gas such as nitrogen or carbon dioxide in order to prevent a side reaction due to oxidation. For this reason, as the reaction apparatus, those made of glass, stainless steel, etc. are selected, and a stirrer, a fractionating apparatus for preventing distillation of the alcohol component by azeotropic distillation of water and the alcohol component, and increasing the temperature of the reaction system It is preferable to use a heating device, a temperature control device for the heating device, and a reaction device provided with a device for blowing an inert gas such as nitrogen.

The number average molecular weight of the unsaturated polyester is 25.
It is preferably from 00 to 4500. Molecular weight 250
If it is lower than 0, even if an appropriate amount of a thickener is added, the thickening does not increase, and when a resin composition is used, problems such as softness and deterioration in workability occur. When the molecular weight is more than 4500, the viscosity is high and impregnation of the glass fiber is impaired.

The polymerizable monomer used in the present invention includes, for example, styrene derivatives such as styrene, chlorostyrene, divinylbenzene, tertiary butyl styrene, bromostyrene, methyl methacrylate, ethyl methacrylate, ethyl acrylate Methacrylic acid or acrylic acid alkyl ester such as butyl acrylate, etc., β-hydroxyethyl methacrylate, β-hydroxyethyl acrylate etc. methacrylic acid or acrylic acid hydroxyalkyl ester, diallyl phthalate, acrylamide, phenylmaleimide and the like. Can be In addition, polyfunctional methacrylic acid or acrylic acid esters such as ethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, and trimethylpropane trimethacrylate can also be used.

An unsaturated polyester resin composition is prepared by blending an unsaturated polyester resin and a polymerizable monomer, and optionally adding a polymerization inhibitor and the like. At this time, the mixing ratio of the unsaturated polyester resin and the polymerizable monomer is 25 to 80 parts by weight of the unsaturated polyester resin and 75 to 75 parts by weight of the polymerizable monomer when the total amount of both is 100 parts by weight. Preferably it is 20 parts by weight. When the amount is less than 25 parts by weight, the viscosity of the unsaturated polyester resin composition is too low to be easily applied to a sheet, and it is difficult to uniformly mix with other components due to sedimentation and the like. Even when the material is molded, the curing shrinkage is large, and the molded product may be cracked or cracked. 80 unsaturated polyester resin
If the amount is more than 10 parts by weight, the viscosity may be too high to be applied or to be difficult to mix with other components. For this reason, it is more preferable that the unsaturated polyester resin is 40 to 65 parts by weight and the polymerizable monomer is 60 to 35 parts by weight. Examples of the polymerization inhibitor include p-benzoquinone, naphthoquinone, tolquinone, hydroquinone, mono-t-butylhydroquinone, dibutylhydroxytoluene, and the like. The polymerization inhibitor is preferably used in an amount of 0.5% by weight or less based on the total amount of the unsaturated polyester resin and the polymerizable monomer. When a curing agent is blended, it is preferable to contain 0.05% by weight or more for storage stability.

[0015] The thermoplastic resin used in the present invention functions as a low shrinkage agent, and polymethyl methacrylate, polystyrene, polycaprolactone, polyvinyl acetate, polyethylene, butadiene rubber and the like are used.
The amount used is determined in consideration of the shrinkage, surface smoothness, and surface gloss of the molded product, and is not particularly limited. The low-shrinkage agent is preferably used in an amount of 20 to 50% by weight based on the total amount of the unsaturated polyester resin and the polymerizable monomer.

Examples of the filler used in the present invention include inorganic fillers such as silica sand, calcium carbonate, talc, and clay, and organic fillers such as wood powder, polyethylene powder, and pulverized products of various FRP molded products. Can be

[0017] To the unsaturated polyester resin composition of the present invention, a silicone rubber is further added as an essential component. This silicone rubber is made to exist in the resin layer on the surface of the molded article, thereby preventing cracks from occurring. The silicone rubber is preferably an unvulcanized (uncured) liquid silicone rubber, and is preferably an RTV type (room temperature curing type) one-pack type or two-pack type, because of its good mixing properties.

In the present invention, when the inorganic filler and the silicone rubber are mixed in a specific compounding amount, a more reinforcing effect is exhibited. The compounding amount is 100 to 200 parts by mass of an inorganic filler and 3 to 40 parts by mass of a silicone rubber with respect to 100 parts by mass of a mixture of an unsaturated polyester resin, a polymerizable monomer and a thermoplastic resin. It is. When the amount of the inorganic filler is less than 100 parts by mass,
Defects such as nests and pinholes are likely to occur in molded products.
If the amount is more than 0 parts by mass, the flowability of the SMC at the time of pressurized heat molding may decrease, resulting in insufficient filling or a decrease in strength. In addition, the compounding amount of silicone rubber is 3
If the amount is less than 10 parts by mass, the impact resistance of the resin layer portion on the surface of the molded product does not increase, so that minute cracks are easily generated.
If the amount exceeds 0 parts by mass, defective portions such as color unevenness, nests and pinholes are likely to occur.

The unsaturated polyester resin composition of the present invention is further blended with a thickener, a curing agent, a release agent, a stabilizer, a coloring agent and the like.

Examples of the curing agent include ketone peroxides, peroxydicarbonates, hydroperoxides, diacyl peroxides, peroxyketals, dialkyl peroxides, peroxyesters, and alkyl peresters. No. Since the amount of the curing agent affects not only the molding cycle but also the preservability of the material, color unevenness, and the like, it is determined according to each. From the viewpoints of the preservability of the material and the molding cycle, the amount of the unsaturated polyester resin and the total amount of the polymerizable monomer may be set at 0.
Preferably 5 to 5% by weight, more preferably 1 to 3% by weight
It is.

As the thickener, magnesium oxide, magnesium hydroxide, potassium oxide, potassium hydroxide and the like are used, but magnesium oxide is generally used. The amount of the thickener is determined depending on the workability of the molding material, but is preferably 0.5 to 5% by weight, more preferably 0.5% by weight, based on the total amount of the unsaturated polyester resin and the polymerizable monomer. 0.7 to 2% by weight. If the amount of the thickener is too small, the viscosity of the resin composition may not increase. On the other hand, if the amount of the thickener is too large, the viscosity may be too high to control.

As the release agent, zinc stearate, calcium stearate and the like are used. The amount of the release agent is preferably 1 to 10% by weight, more preferably 2 to 10% by weight based on the total amount of the unsaturated polyester resin and the polymerizable monomer.
4% by weight. If the amount of the release agent is too small, if the amount is less than 1 part by weight, the molded article may stick to the mold, making it difficult to remove the mold, and cracking the molded article. If the amount of the release agent is too large, the strength of the molded article tends to decrease.

The unsaturated polyester resin composition of the present invention can further contain a reinforcing fiber to obtain a fiber-reinforced molding material. At this time, the unsaturated polyester resin contains a thickener and a curing agent as essential components. Further, it preferably contains a filler, a low shrinkage agent, a release agent, and a polymerization inhibitor. As fiber reinforced molding materials, SMC,
BMC and the like. As the reinforcing material, glass fiber, carbonate fiber, aramid fiber, polyvinyl alcohol-based fiber, or the like can be used, and glass fiber is generally used. These reinforcing materials are used in the form of continuous fibers, woven fabrics, non-woven fabrics, and the like. Roving-like materials are preferably cut to an appropriate length (in the case of SMC, cut to 20 to 30 mm, and BMC is preferably used. In the case of (1), a chopped strand cut to a length of about 1 inch (25.4 mm), for example, a chopped strand cut preferably to 6 to 15 mm is used. In producing the fiber-reinforced molding material, the amount of the reinforcing fiber used depends on the required strength, but is in the range of 15 to 42% by weight based on the total amount of the unsaturated polyester resin and the polymerizable monomer. Is preferred. When the content of the glass fiber is less than 15% by mass, the strength as a molded product is reduced, and 42% by mass.
If the ratio exceeds the above, the compound may not be sufficiently impregnated into the glass fiber, and conversely, the strength as a molded article may be reduced.

The method for molding a fiber-reinforced molded article (FRP molded article) using the unsaturated polyester resin composition is not particularly limited, and examples thereof include an open mold such as a hand lay-up method, a spray-up method, and a centrifugal molding method. Molding,
Injection molding, compression molding, casting molding, transfer molding,
Extrusion molding, back molding, cold press molding, RT
Examples include closed molding such as M molding, resin injection molding, and matched metal die molding, and continuous molding can also be performed.

The aforementioned fiber-reinforced molding material, for example, SMC
And BMC, respectively, are ordinary SMC manufacturing equipment or BMC.
It can be manufactured using an MC manufacturing apparatus. In the case of SMC, the prepared resin is applied on the release film so as to have a uniform thickness, and a reinforcing material such as glass fiber cut to a predetermined length is evenly spread thereon, and further on this. Another film coated with the compounding resin is superimposed so that the stiffener sprinkled with the compounding resin is sandwiched between the layers, and this is wound up in a roll and, if necessary, matured to form a sheet-shaped molding material. Can be. When a thickener is added, it is preferable to heat the mixture to a temperature of room temperature to 60 ° C. for aging.
As the release film, a polyethylene film, a polypropylene film, or the like can be used. In the case of BMC, reinforcing fibers are mixed with the unsaturated polyester resin composition described above, but there is no particular limitation on the mixing order of the components used in these.

The viscosity of the fiber-reinforced molding material is preferably adjusted so as to be 1,000 to 18,000 Pa · s at 40 ° C. If the viscosity is too low, scumming is likely to occur on the surface of the molded article, and if the viscosity is too high, the mold clamping time will be long and the molding cycle will tend to be long. The viscosity of the fiber-reinforced molding material is 1,5 at 40 ° C.
It is more preferably adjusted to be from 00 Pa · s to 15,000 Pa · s, and from 3,500 to 12,000 P
It is particularly preferred that the adjustment be made to be a · s. However, the optimum viscosity of the fiber-reinforced molding material is determined by the molded product. The viscosity of the fiber-reinforced molding material can be adjusted by the amount of the thickener and the aging conditions.

Such a sheet-like molding material is formed by compression molding, transfer molding, or the like, and has a wide range of F
An RP molded product can be obtained. Molding temperature is 70-15
It is preferable that the molding pressure is 0 ° C. and the molding pressure is 0.1 to 10 MPa.

When the SMC manufactured as described above is used, cracks are less likely to occur when subjected to an impact during transportation and the like, and it is excellent for large containers such as panel-assembled water tanks, septic tanks, and large molded products. Can have characteristics.

[0029]

EXAMPLES Preparation of SMC As shown in Tables 1 and 2, among the unsaturated polyester resin compositions, an unsaturated polyester diluted with a polymerizable monomer, a thermoplastic resin, a curing agent, and a polymerization inhibitor were used. , Template,
And thickener, the compounding amount is constant, and filler, and silicone rubber, by changing the type and compounding amount,
In addition, SMC was produced by changing the amount of glass fibers impregnated with these compounds.

The following materials were used for each component. Among the polymerizable monomers, an unsaturated polyester resin (Polyset PS-9415, manufactured by Hitachi Chemical Co., Ltd., trade name) diluted with styrene, and a thermoplastic resin, polystyrene (Denka Styrol, manufactured by Denki Kagaku Kogyo Co., Ltd.) Name), t-butyl peroxybenzoate (Perbutyl Z, manufactured by NOF Corporation, trade name) as a curing agent, parabenzoquinone (PBQ, manufactured by Seiko Chemical Co., Ltd.) as a polymerization inhibitor,
Product name), zinc stearate (zinc stearate, manufactured by NOF CORPORATION, trade name) as a release agent, and magnesium oxide (Kyowa Mag # 20, manufactured by Kyowa Chemical Industry Co., Ltd., trade name) as a thickener Was.

The filler is calcium carbonate (NS # 2).
00, manufactured by Nitto Powder Chemical Industry Co., Ltd., silicone rubber KE-3490 (trade name of Shin-Etsu Chemical Co., Ltd.) for silicone rubber, and chopped strand of approximately 1 inch (glass roving # 750, (Trade name, manufactured by Nitto Boseki Co., Ltd.).

Examples 1 to 4 As shown in Table 1, the proportions of the components having a constant blending amount were as follows:
It was as follows. 80 parts by mass of an unsaturated polyester resin (40 parts by mass of a styrene solution) diluted with a polymerizable monomer styrene and polystyrene 20 dissolved in styrene
With respect to 100 parts by mass of a mixture of an unsaturated polyester diluted with styrene of the polymerizable monomer and polystyrene dissolved with styrene, t-butyl par as a curing agent was used. 1 part by mass of oxybenzoate, parabenzoquinone O. 05 parts by mass, 4 parts by mass of zinc stearate as a template, and 0.8 parts by mass of magnesium oxide as a thickener were blended.

The filler calcium carbonate is 12
0 parts by mass, 150 parts by mass, and 180 parts by mass, and 5 parts by mass, 25 parts by mass, and 35 parts by mass of the silicone rubber were compounded. Compounds composed of these were impregnated into 29% by mass, 32% by mass, and 35% by mass of chopped strands of glass fiber. In addition, SMC is the coating width 1,
It was produced using a 200 mm coating machine and aged.

Comparative Examples 1 to 7 As shown in Table 2, the proportions of the components having a fixed amount were as follows:
It was as follows. 80 parts by mass of an unsaturated polyester diluted with styrene as a polymerizable monomer (40% by mass of a styrene solution), 20 parts by mass of polystyrene dissolved in styrene (40% by mass of a styrene solution), and the polymerizable monomer 100 parts by mass of a mixture of unsaturated polyester diluted with styrene and polystyrene dissolved with styrene, 1 part by mass of t-butyl peroxybenzoate as a curing agent, 0.05 parts by mass of parabenzoquinone as a polymerization inhibitor,
4 parts by mass of zinc stearate as a template and 0.8 part by mass of magnesium oxide as a thickener were blended.

The amount of the calcium carbonate filler was changed from 80 parts by mass in Comparative Example 4 which is the minimum amount to 230 parts by mass in Comparative Example 5 which was the maximum amount. The blending amount was changed from 2 parts by mass of Comparative Example 2 to 45 parts by mass of Comparative Example 3 which was the maximum blending amount. The compound consisting of these was used as the minimum content of chopped strand of glass fiber in Comparative Example 6-2.
From 3% by mass, the maximum content is 45% by mass of Comparative Example 7.
And then impregnated. The SMC is the coating width 1, 2
It was produced using a 00 mm coating machine and aged.

Panel molding SMs shown in Examples 1 to 4 in Table 1 and Comparative Examples 1 to 7 in Table 2
Using C, a flat plate having a size of 220 cm square was pressed and heated.
The molding conditions were as follows: SMC input weight 1.5 kg, charge area 0.05 m ² (15 cm square), molding pressure 9 MP
a, Molding was performed for 4 minutes.

Test Methods The flat plates formed in Examples 1 to 4 and Comparative Examples 1 to 7 were observed for surface conditions such as presence of pits and pinholes. The results are shown in Tables 1 and 2. Further, a steel ball having a weight of 1 kg was dropped on the surface of the formed flat plate from a certain height, and the falling height at which cracks occurred on the flat plate surface was evaluated. The results are also shown in Tables 1 and 2.

[0038]

[Table 1]

[0039]

[Table 2]

As is clear from the results shown in Tables 1 and 2, the flat plates formed in Examples of the present invention had good formability and were less likely to crack on the surface of the formed product.

[0041]

The unsaturated polyester resin composition according to the present invention contains an unsaturated polyester resin, a polymerizable monomer, a thermoplastic resin, an inorganic filler and a silicone rubber as essential components. In a molded article obtained by impregnating fibers into SMC and applying pressure and heating using this SMC, cracks hardly occur on the surface of the resin layer.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C08L 101/00 C08L 101/00 F term (reference) 4F072 AA05 AA07 AA08 AB09 AD38 AE06 AE13 AF01 AG03 AG04 AK11 AK12 AK13 AK14 AK15 4J002 AC03X BB03X BC03X BF02X BG06X CF21W CL01X CP03Y DE237 DJ007 DJ037 DJ047 EA046 EB106 EH076 FD017

Claims (4)

[Claims] 1. An unsaturated polyester resin composition comprising, as essential components, an unsaturated polyester resin, a polymerizable monomer, a thermoplastic resin, an inorganic filler and a silicone rubber. 2. 100 to 200 parts by mass of an inorganic filler and 3 to 40 parts by mass of a silicone rubber are added to 100 parts by mass of a total of an unsaturated polyester resin, a polymerizable monomer, a polymerizable monomer and a thermoplastic resin. The unsaturated polyester resin composition according to claim 1, which contains the unsaturated polyester resin composition. 3. A sheet molding compound comprising 15 to 42% by mass of glass fibers in a sheet molding compound obtained by using the unsaturated polyester resin composition according to claim 1. 4. A sheet molding compound obtained by applying pressure and heat to the sheet molding compound according to claim 3.