JP2001279077A - Sheet-molding compound and molded product produced from the compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet-molding compound that gives a reduced amount of the fired residue and shows excellent recycling properties and heat resistance and provide molded products produced from the compound. SOLUTION: In the objective sheet-molding compound that is produced by impregnating an organic fibrous base material with the unsaturated polyester composition containing an unsaturated polyester resin, a polymerizable monomer, a low-shrinking material, a curing agent and a thickener, the content of the organic fibrous base material is characteristically adjusted to 2-40 mass % and the content of the short-cut glass fiber is to 0.5-5 mass %. The resultant compound is compression heat-molded to give the objective molded product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to bathroom equipment such as a bathtub, a washing pan, and a bathroom wall panel, a panel assembled water tank,
The present invention relates to a sheet molding compound (hereinafter, referred to as SMC) which is a molding material used for a septic tank or the like, and a molded product obtained by molding the SMC.

[0002]

2. Description of the Related Art SMC is an unsaturated polyester diluted with a vinyl monomer and added as additives such as a low-shrinking agent, a curing agent, a polymerization inhibitor, a filler, a thickener, a template, and a coloring agent. It is a molding material which is impregnated with glass fiber into a paste mixed with an agent or the like, formed into a sheet, covered on both sides with a carrier film, and aged and semi-solidified. The SMC is placed on a mold and molded by heating under pressure, and is manufactured as an SMC molded product such as a bathtub, a panel-assembled water storage tank, and a septic tank.

[0003]

The SMC molded article molded under pressure and heat as described above has excellent durability, water resistance, mechanical strength, gloss of the molded article surface, etc., and freedom of shape. It is widely used as bathroom equipment such as bathtubs, panel-assembled water storage tanks, septic tanks, etc. because of its large design and excellent design. However, the above-mentioned SMC molded products have difficulty in recyclability and industrial waste treatment as compared with dicyclopentadiene, thermoplastic resin molded products and the like. That is,
SMC molded products generally contain glass fiber as a reinforcing material in an amount of 10 to 50% by mass. Therefore, when heat recovery and recycling are performed using a raw material such as cement fuel, compared with other thermoplastic resin molded products, In addition, there are problems such as a low amount of generated heat and poor heat recovery efficiency, and a large amount of waste disposal after combustion due to remaining glass fibers.

[0004] Further, since the material recycling contains glass fibers, it is difficult to separate the glass recycling at present, and it is impossible at present, and the material must be landfilled, which is becoming an environmental problem. Further, since the SMC molded product contains glass fibers having a high specific gravity, the specific gravity is higher than that of a dicyclopentadiene resin or a thermoplastic resin, making it difficult to reduce the weight of the product and inferior in workability. Because of this, SMC
Molded articles are being replaced by dicyclopentadiene resins and thermoplastic resins that do not contain glass fibers in septic tanks, panel-assembled water tanks, exterior members for automobiles, and the like.

[0005] The present invention has been made in view of the above problems, and has as its object to provide an SMC and an SMC molded product having excellent recyclability.

[0006]

The present invention relates to the following. (1) In a sheet molding compound in which a fiber base material is impregnated with an unsaturated polyester resin composition containing an unsaturated polyester, a polymerizable monomer, a thermoplastic resin and a filler, glass having an average length of 0.05 mm to 2 mm A sheet molding compound comprising 0.5 to 5% by mass of a fiber and 2 to 40% by mass of an organic fiber base as a fiber base. (2) The sheet molding compound according to item (1), wherein the organic fiber base material is a nonwoven fabric mainly having a fiber length of 3 to 150 mm. (3) The sheet molding compound according to item (1) or (2), wherein the organic fiber base is mainly made of polyester fiber. (4) A sheet molding compound molded product obtained by subjecting the sheet molding compound according to any one of items (1) to (3) to pressure and heat molding.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The sheet molding compound (SMC) of the present invention is a fiber reinforced compound comprising an unsaturated polyester resin, a polymerizable monomer, a low shrinkage agent, a curing agent, a thickener and a fiber reinforcement. A molding material formed in a sheet shape.

[0008] The unsaturated polyester resin in the present invention is obtained by reacting a polybasic acid component containing an α, β-unsaturated polybasic acid or an anhydride thereof as an essential component with a polyhydric alcohol. In the present invention, examples of the α, β-unsaturated polybasic acid or an anhydride thereof, which is a raw material for synthesizing an unsaturated polyester resin, include, for example, α, β-unsaturated dibasic acid or an anhydride thereof, for example, maleic acid, Examples include fumaric acid, itaconic acid, 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 amount 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.

The method for producing the unsaturated polyester resin can be a conventionally known method. 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, tert-butylstyrene, and bromostyrene, methyl methacrylate, ethyl methacrylate, and 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 is blended with a polymerizable monomer, and if necessary, a polymerization inhibitor and the like are added to obtain an unsaturated polyester resin composition. 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.

As the low shrinkage agent used in the present invention, thermoplastic resins such as polymethyl methacrylate, polystyrene, polycaprolactone, polyvinyl acetate, polyethylene and butadiene rubber 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.

The curing agent used in the present invention includes ketone peroxides, peroxydicarbonates, hydroperoxides, diacyl peroxides,
Peroxy ketals, dialkyl peroxides,
Peroxyesters, alkyl peresters and the like can be mentioned. 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 storage stability of the material and the molding cycle, the amount is preferably 0.5 to 5% by weight, more preferably 1 to 3% by weight, based on the total amount of the unsaturated polyester resin and the polymerizable monomer.

As the thickener, magnesium oxide, magnesium hydroxide, potassium oxide, potassium hydroxide and the like are used, and generally, magnesium oxide is 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.

The glass fiber having an average length of 0.05 mm to 2 mm is preferably contained in the unsaturated polyester resin composition in advance. It is preferable that the used amount is included so as to be 0.5 to 5% by mass with respect to the total amount of SMC. When the average length of the short glass fiber is less than 0.05 mm, when the SMC molded article is formed, the reinforcing effect thereof is insufficient, and the effect of improving the heat resistance is small. When the thickness exceeds 2 mm, the heat resistance is improved, but the viscosity of the unsaturated polyester resin composition is increased. Therefore, the impregnation property of the organic fiber base material during SMC coating is reduced, and defects such as blistering during molding are reduced. It is more likely to occur, and the strength of the molded article also decreases. The amount of the short glass fiber is preferably 0.5% by mass or more and 5% by mass or less in the obtained SMC. Addition weight is 0.5% by mass
If it is less than 5%, the effect of improving heat resistance is not sufficient, and if it exceeds 5% by mass, the viscosity of the unsaturated polyester resin composition increases, and the occurrence of blistering and strength reduction of the molded product due to the decrease in impregnation into the organic fiber base material is reduced. To happen.

As the inorganic filler, silica sand, calcium carbonate, magnesium silicate, aluminum silicate, aluminum hydroxide, silicon dioxide, talc, clay and the like may be used in combination. The total amount of the inorganic filler is preferably 100 to 200 parts by mass based on 100 parts by mass of the mixture of the unsaturated polyester resin, the polymerizable monomer and the low-shrinking agent.

The above-mentioned unsaturated polyester resin composition is further blended with a releasing agent, a stabilizer, a coloring agent and the like as appropriate.

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.

Organic fibers are used as the fiber reinforcing material. The content of this organic fiber in SMC is 2 to 40% by mass.
Is preferred. If the content is less than 2% by mass, the reinforcing effect is not sufficient, and the strength of the obtained SMC molded product is insufficient. On the other hand, if it exceeds 40 mass, the impregnating property to the unsaturated polyester resin composition is reduced, and defects such as fibrous eyes, blisters, cracks, pinholes, etc. are generated in the molded product, which impairs the appearance of the product and decreases the strength. This is because The form of the organic fiber used may be a non-woven fabric, cloth, chopped short fiber, or the like, but the non-woven fabric has a higher fluidity than the cloth at the time of forming the SMC (at the time of manufacturing a molded product). Good fiber uniform dispersibility and resin impregnation are better than chopped short fibers. The length of the organic fiber constituting the organic fiber base material is preferably 3 to 150 mm. If the fiber length is less than 3 mm, the reinforcing effect is insufficient and the strength of the molded product is insufficient, and if it exceeds 150 mm, the fluidity of the resin at the time of molding is poor, the appearance of the molded product is impaired, and the filling of ribs and bosses is also poor. This is because the use and shape of the molded product are limited. As the above organic fibers, polyester fibers, cellulose fibers, nylon fibers, aramid fibers, and the like can be used, but polyester fibers are preferred because of their excellent adhesion to unsaturated polyester resins.

The SMC can be manufactured by using an ordinary SMC manufacturing apparatus. The unsaturated polyester resin composition is applied to a carrier film disposed above and below so as to have a uniform thickness, and a fiber reinforcement of a predetermined size unwound from an unwinder is disposed above and below. The carrier film is sandwiched between the unsaturated polyester resin compositions, and then the whole is passed between impregnating rolls, and the fiber reinforcing material is impregnated with the unsaturated polyester resin composition by applying pressure, and then rolled. Fold it up and roll it up. Thereafter, aging and the like are performed as necessary. 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.

The viscosity of SMC at 40.degree.
It is preferably adjusted to be 0 to 18,000 Pa · s. 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 from 1,500 Pa · s at 40 ° C.
It is more preferably adjusted to be 15,000 Pa · s, and particularly preferably adjusted to be 3,500 to 12,000 Pa · 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.

The SMC is formed by compression molding, transfer molding or the like, and a wide range of FRP molded products can be obtained. Molding temperature is 70-150 ° C, molding pressure is 0.1
It is preferably from 10 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 or the like, and it is excellent for large containers such as panel-assembled water tanks and septic tanks, and large molded products. Can have characteristics.

[0028]

EXAMPLES In the following, polystyrene PS-9415 was used as an unsaturated polyester resin diluted with styrene.
(Styrene solution of 40% by mass of unsaturated polyester resin,
Polystyrene (Denka Styrol, trade name of Denki Kagaku Kogyo Co., Ltd.) was used as a low shrinkage agent.

Examples 1 to 5 and Comparative Examples 1 to 5 (Preparation of SMC) 80 parts by weight of an unsaturated polyester resin dissolved in styrene (60% by weight of styrene) and 20 parts by weight of polystyrene dissolved in styrene (70 parts by weight of styrene) Parts by mass) and 1 part by mass of t-butyl peroxybenzoate as a curing agent with respect to 100 parts by mass of a mixture of an unsaturated polyester diluted with styrene as the polymerizable monomer and polystyrene dissolved with styrene. 0.06 parts by mass of parabenzoquinone as an inhibitor, 3.5 parts by mass of zinc stearate as a release agent, 0.7 parts by mass of magnesium oxide as a thickener, 140 parts by mass of calcium carbonate, and glass fiber (average fiber length 1 mm) Was blended in the amounts shown in Table 1 or Table 2.
The unsaturated polyester resin composition thus obtained was impregnated with predetermined organic fibers at a predetermined content as shown in Table 1 or Table 2 to prepare SMC.

Production of Molded Product Using the SMC obtained above, a flat plate of 220 cm square was molded under pressure and heat. The molding conditions were as follows: SMC input weight 0.5 kg, charge area 0.05 m ² (15 cm
Corner), molding pressure of 9 MPa, and holding time of 4 minutes.

Test method (1) Impregnating property of fiber substrate The fiber substrate in the obtained SMC sheet was observed while removing the resin on the surface with a cutter knife, and the portion of the fiber substrate not impregnated with the resin was observed. The presence or absence was visually determined. The case where there was no portion of the fiber base material not impregnated with the resin was evaluated as Δ, and the case where there was a portion was evaluated as x. (2) Appearance of molded article The obtained molded article was visually observed, and the degree of SMC filling, presence of defects such as blisters, nests, and pinholes were examined. Those having no defect were evaluated as Δ, and those having defect were evaluated as x. (3) Molded product specific gravity It was measured by an electronic balance type specific gravity meter. (4) Bending strength Measured by a tensile tester manufactured by Orientec Co., Ltd. in accordance with JIS K 6911. (5) Heat resistance An oil pan preheated to a temperature on the surface of the molded article was placed, and the minimum temperature of the oil pan at which deformation such as blisters occurred on the surface when left for 30 seconds was examined.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

According to the present invention, SM is obtained by impregnating an unsaturated polyester resin composition with an organic fiber as a fiber base in place of glass fiber.
C and its molded product have a low specific gravity, are useful for reducing the weight of the product, and are excellent in heat resistance. In addition, the incineration residue is small due to a small amount of non-incinable glass fiber, and therefore, the thermal efficiency is high even as a cement-burning raw material, and the residue is in powder form, so that disposal is easy.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 5/00 C08K 5/00 7/14 7/14 C08L 101/00 C08L 101/00 // B29L 7: 00 B29L 7:00 (72) Inventor Mamoru Kimura 1250 Shimoe-ren, Shimodate-shi, Ibaraki Pref. AB11 AB25 AD16 AH49 MA10 MB01 MC03 4J002 AB013 AC032 BB032 BC032 BF022 BG062 CF033 CF192 CF221 CL003 CL063 DE147 DE237 DJ007 DJ017 DJ037 DJ047 DL008 EA046 EB126 EF046 EH076 EH146 FA043 FA048 FD010 FD017 FD140 FD160 FD140 FD140 FD140 FD140 FD140 FD140 FD140 FD140 FD140 FD140 FD140 FD140 FD140 FD140 FD140 FD017 FD140 FD140

Claims (4)

[Claims] An average length of a sheet molding compound obtained by impregnating an unsaturated polyester resin composition containing an unsaturated polyester, a polymerizable monomer, a thermoplastic resin and a filler into a fiber base material is 0.05 mm to 2 mm. A sheet molding compound comprising 0.5 to 5% by mass of a glass fiber and 2 to 40% by mass of an organic fiber base as a fiber base. 2. The organic fiber substrate has a fiber length of 3 to 150 mm.
The sheet molding compound according to claim 1, which is a nonwoven fabric mainly composed of: 3. The sheet molding compound according to claim 1, wherein the organic fiber base is mainly composed of polyester fibers. 4. A sheet molding compound molded product obtained by pressurizing and heating the sheet molding compound according to claim 1.