JPH0788868A - Production of profile molded product made of thermosetting resin - Google Patents

Abstract

PURPOSE:To produce a molded product excellent in surface appearance and product strength by heating pressure molding. CONSTITUTION:A molding material I containing 1.5wt.% of a fibrous reinforcing material with a fiber length of 0.1-3.5mm is stuck to the visible surface of a molded product and a molding material II containing 5-15wt.% of a fibrous reinforcing material with a fiber length of 1-7mm is stuck to the non-visible surface of the molded product to be subjected to heating pressure molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a thermosetting resin shaped article by laminating two or more semi-solid molding materials containing a thermosetting resin and a fibrous reinforcing material and heat-pressing them. The present invention relates to a method for producing a thermosetting resin irregularly shaped product capable of uniformly improving the strength of a molded product without impairing the smoothness of the surface of the molded product.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a molded article by curing a thermosetting resin molding material composed of a thermosetting resin such as an unsaturated polyester resin, an acrylic resin or an epoxy resin, a heat and pressure molding method has been used. Widely used due to its short time. Such a heat and pressure molding method is widely used for manufacturing molded articles such as bathtubs, wash counters, kitchen counters, and tables.

In recent years, there has been an increasing trend toward higher grades in such molded products as well, and in irregularly shaped products such as bathtubs and wash-counters, which are composed of a repetitive structure of a horizontal surface and an inclined surface. There has been a demand for a material having better surface smoothness.

The heat and pressure molding method generally involves thickening a thermosetting resin composition obtained by mainly adding a filler made of an inorganic material or the like and a reinforcing material such as fiber to the thermosetting resin as described above. This is a molding method in which a semi-solid molding material is introduced into a mold or the like and heat and pressure are applied to obtain a molded product. The resin molding material used in this molding method includes a sheet molding compound (hereinafter referred to as SMC),
A bulk molding compound (hereinafter referred to as BMC) or the like is generally used. When a shaped article such as a bathtub is manufactured using these molded products, a plurality of SMCs are used as molds, as disclosed in, for example, Japanese Patent Application Laid-Open No. 50-137250, due to manufacturing and working restrictions. And is laminated and molded.

In such a heat and pressure molding method, in order to obtain a molded article having an excellent surface appearance, the length of the reinforcing material to be added is shortened or the amount of the reinforcing material is reduced to improve the fluidity, The undulation phenomenon and the wavy phenomenon on the surface are prevented. Therefore, there is a problem that the strength of the obtained molded product is inferior to the so-called hand lay-up molded product or cast molded product, which requires a long molding time.

[0006]

In order to improve such a defect in strength, Japanese Unexamined Patent Publication No. 1-141010 proposes a method of integrally molding a fiber reinforced mat during molding. However, according to this method, since the fiber reinforced mat is separately used, the material cost of the molded product is increased, and the number of working steps is increased, so that the manufacturing cost is increased. Furthermore, this method
It does not give a sufficiently satisfactory result for a molded product having a complicated shape such as a deformed molded product.

The object of the present invention is to solve the above-mentioned conventional problems and to improve the strength of the molded product uniformly without impairing the smoothness of the surface of the molded product. It is to apply the manufacturing method of the product.

[0008]

The production method of the present invention is a method in which two or more semi-solid molding materials containing a thermosetting resin and a fibrous reinforcing material are laminated and heated and pressure-molded. A molding material containing 1% by weight to less than 5% by weight of a fibrous reinforcing material of 0.1 to 3.5 mm (hereinafter referred to as "molding material I") is laminated on the visible surface side of the molded product to have a fiber length of 1 ~ 7 mm
The molding material containing 5 to 15% by weight of the fibrous reinforcing material (hereinafter referred to as "molding material II") is laminated on the non-visible surface side of the molded product.

The semi-solid molding material in the present invention is a thermosetting resin and an inorganic filler, a reinforcing material, a curing agent, and if necessary, a curing accelerator, an inhibitor, an internal release agent, a thickener, and a low shrinkage. A resin composition is prepared by mixing agents, pigments, etc.
It is possible to use a semi-solid product that is aged at 0 to 50 ° C.

Examples of the fibrous reinforcing material used in the present invention include glass fiber, polyester, phenol resin, organic fiber such as vinylon, carbon fiber, and the like.
Especially glass fiber is preferable.

The fibrous reinforcing material added to the molding material I has a fiber length of 0.1 to 3.5 mm, preferably 1 to 2 mm.
Use the reinforcement material. When the fiber length is shorter than these ranges, the reinforcing effect cannot be sufficiently obtained, and when the fiber length is longer than these ranges, the surface appearance of the molded product is deteriorated.

The amount of the fibrous reinforcing material added to the molding material I is 1% by weight to less than 5% by weight, preferably 2 to
It is 4% by weight. If the amount added is too small, a sufficient reinforcing effect cannot be obtained, and if the amount added is too large, the surface appearance of the molded product deteriorates.

The fiber length of the fibrous reinforcing material added to the molding material II is 1 to 7 mm. If the fiber length is shorter than 1 mm, the reinforcing effect is not sufficiently exhibited, and if it exceeds 7 mm, the fluidity at the time of molding becomes poor.

The amount of the fibrous reinforcing material added to the molding material II is 5 to 15% by weight. If the amount added is less than 5% by weight, a sufficient reinforcing effect cannot be obtained, and if it exceeds 15% by weight, poor flow will occur during molding.

The ratio of the molding material II to the total molding material at the time of molding can be arbitrarily set depending on the amount of the reinforcing material, the length of the reinforcing material and the like, but is usually preferably 50% by weight or less, and more preferably 50% by weight or less. It is 40% by weight or less.
When the proportion of the molding material II is large, the molding material II has an influence on the surface appearance, and waviness and waviness are likely to occur.

As for the laminated form of the molding materials I and II during molding, the molding material I is placed on the visible surface side of the molded article as described above.
The molding material II is placed on the non-visible surface side of the molded product. In the present invention, the visible surface side and the invisible surface side of the molded product are 2 in the thickness direction.
It can be divided and set. The molding material II may be arranged anywhere on the non-visible surface side of the molded product determined in this way. The molding material I may be laminated on the non-visible surface side of the molded product. In molding of a shaped article, the laminated materials show a complicated flow, and the molding material II may pass through the molding material I in the flowing process. Therefore, the proportion of the molding material II is preferably 50% by weight or less, and the laminated thickness is preferably 50% or less. In general, on the non-visible surface side of the molded article, it is preferable to laminate and mold another molding material having a higher content ratio of the fibrous reinforcing material than the molding material II, because it impedes the fluidity of the entire molding material. Absent.

In the present invention, the molding material II is preferably laminated on the entire surface of the molded product, but in some cases, it can be laminated only on a predetermined portion of the laminated product.
As the thermosetting resin used in the present invention, any known one can be used, and examples thereof include unsaturated polyester resin, epoxy resin, vinyl ester resin and the like.

As the curing agent, t-butylperoxybenzoate, benzoyl peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, t-
Butyl peroxy-2-ethyl hexanoate, 1,1
Examples thereof include organic peroxides that act on the thermosetting resin such as di-t-butylperoxycyclohexane and t-butylperoxy-isopropyl carbonate.

Examples of the fillers include calcium carbonate, magnesium carbonate, barium sulfate, talc, clay, mica, silica, alumina, glass powder, aluminum hydroxide, magnesium hydroxide, cold water stone, silica sand, and the like. You may mix and use 1 or more types. The filling amount is 50 to 3 with respect to 100 parts by weight of the thermosetting resin component.
The range of 60 parts by weight is preferable, and the particle size is 1 to 30.
μm is preferred.

As the internal release agent, higher fatty acids such as stearic acid and zinc stearate, higher fatty acid salts, alkyl phosphates and the like are used. Thickeners are those that chemically bond with hydroxyl groups, carboxyl groups, ester groups, etc. possessed by unsaturated polyesters to cause linear or partial cross-linking to increase the molecular weight and thicken unsaturated polyester resins. There are, for example, diisocyanates such as toluene diisocyanate, metal alkoxides such as aluminum isopropoxide and titanium tetrabutoxide, oxides of divalent metals such as magnesium oxide, calcium oxide and bryllium oxide, and calcium hydroxide. A divalent metal hydroxide or the like is used.

As the low-shrinkage material, polyethylene, polystyrene, polymethylmethacrylate, polyvinyl chloride, polyvinyl acetate, polycaprolactam, thermoplastic resins such as saturated polyester, polybutadiene rubber, polystyrene-acrylonitrile copolymer and the like are used. be able to.

[0022]

In the present invention, the molding material I containing a relatively small amount of the fibrous reinforcing material having a relatively short fiber length is provided on the visible side of the molded product, and a relatively large amount of the fibrous reinforcing material having a relatively long fiber length is used. The contained molding material II is placed on the non-visible surface side of the molded product and laminated, and this is heat-pressed. At the time of heat and pressure molding, the molding material I and the molding material II mainly flow in the mold to form a molded product, in which case the molding material II is laminated only on the invisible surface side of the molded product. Therefore, a molded product having excellent strength can be obtained without deteriorating the surface appearance of the molded product.

[0023]

EXAMPLES The present invention will be described in detail below with reference to examples according to the present invention. Examples 1 to 6 The molding material I and the molding material II were blended in a kneader in the proportions shown in Table 1 and aged at 40 ° C. for 24 hours to obtain BMC.
Was manufactured. BMC was manufactured by the same manufacturing method and process for both molding materials I and II. In Table 1, the blending amount is indicated by the number of parts by weight.

The molding materials I and II of Examples 1 to 6 are shown in FIG.
~ Laminated in a laminated pattern as shown in Fig. 6, placed in the lower mold 1 as shown in Fig. 1, and molded at a molding temperature of 140 ° C, a molding pressure of 100 kgf / cm ² and a molding time of 7 minutes ( (The upper die is not shown). As a result, a molded product 2 as shown in FIG. 2 was obtained. The dimension of the molded product 2 is 300mm in length ×
The width is 300 mm and the height is 200 mm, and the thickness is 7 mm.

In Examples 1, 3 and 4, as shown in FIG.
Four molding materials I are laminated on one molding material II and heat-pressed. In the second embodiment, as shown in FIG. 5, three molding materials I are placed on two molding materials II, and heat molding is performed in a laminated state. In Example 5, as shown in FIG. 4, one molding material II is placed on one molding material I, and three molding materials I are placed on the molding material I, and heat molding is performed in a laminated state. Example 6 is a slightly thick molding material as shown in FIG.
Heat and pressure molding is performed in the state where two molding materials II having a relatively large thickness are laminated on one II. B shown in FIGS. 3, 4 and 5
The weight per MC is 1 kg, and the weight per BMC shown in FIG. 6 is 1.7 kg.

The main compounding materials used in the molding materials I and II are as follows. -Unsaturated polyester: Isophthalic acid, propylene glycol maleate as a main component, styrene content of 30-40
% By weight ・ Glass powder: manufactured by Nippon Fellow Co., Ltd. (particle size: 10 μm) ・ Aluminum hydroxide: (particle size: 15 μm) ・ Calcium carbonate: manufactured by Nitto Koka Co., Ltd., product name NS-100
(Particle size 2 μm) ・ Glass fiber: fiber length 1.5 mm ・ Glass fiber: fiber length 3 mm ・ Glass fiber: fiber length 6 mm The obtained molded product was subjected to bending strength and Charpy impact test. Bending strength and Charpy impact test are JIS
Based on K6911, a test piece was cut out from the bottom surface of the molded product and measured. The measurement results are shown in Table 1. The appearance of the surface of the molded product was inspected according to the following criteria, and the results are shown in Table 1.

◯: The surface is smooth. X: The surface is wavy, wavy, etc. and not smooth.

[0028]

[Table 1]

Comparative Examples 1 to 4 Molding materials I and II were produced at the compounding ratios shown in Table 2 and heat-pressed in the same manner as in the above-mentioned Examples to obtain molded articles. In Comparative Examples 1 and 2, only the molding material I was stacked and molded. In Comparative Example 3, as shown in FIG. 7, heat molding was performed in a laminated state in which one molding material II was placed on four molding materials I. In Comparative Example 4, a molding material II containing a larger amount of glass fibers than the amount specified in the present invention was used, and as shown in FIG. 3, one molding material II was stacked with four molding materials I. Was heated and pressed.

Bending strength, Charpy impact value, and surface smoothness of the obtained molded product were evaluated in the same manner as in the above-mentioned examples.

[0031]

[Table 2]

As shown in Table 1, in Examples 1 to 6 according to the present invention, molded products having high mechanical properties and excellent surface smoothness can be obtained. On the other hand, as shown in Table 2, in Comparative Example 1 formed only from the molding material I, although the surface smoothness was excellent, the mechanical physical strength was low. Further, in Comparative Example 2 in which a large amount of glass fiber was blended, the mechanical physical strength was high, but the surface smoothness was poor. Further, in Comparative Example 3 in which the molding material II is arranged on the visible surface side, which is the opposite of the present invention, the surface smoothness is poor. Further, in Comparative Example 4 in which the molding material II contains a large amount of glass fibers, the mechanical physical strength is high, but the surface smoothness (frame top surface) is deteriorated.

[0033]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, a molding material I containing a relatively small amount of a fibrous reinforcing material having a relatively short fiber length.
By laminating on the visible surface side of the molded product, and laminating a molding material II containing a relatively large amount of fibrous reinforcing material having a relatively long fiber length on the non-visible surface side of the molded product and heating and pressing. In addition, it is possible to mold a molded product having excellent surface appearance and excellent product strength. Therefore, the manufacturing method of the present invention can be widely used for manufacturing shaped articles such as bathtubs, washstands, kitchen counters, and tables.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which molding materials I and II are laminated and arranged in a mold on the non-visible surface side in an example according to the present invention.

FIG. 2 is a perspective view showing a molded product to be molded in the embodiment according to the present invention.

FIG. 3 shows a molding material I and an example according to the present invention.
Sectional drawing which shows the laminated state of II.

FIG. 4 is a sectional view showing a laminated state of molding materials I and II in another example according to the present invention.

FIG. 5 is a cross-sectional view showing a laminated state of molding materials I and II in still another example according to the present invention.

FIG. 6 is a sectional view showing a laminated state of molding materials I and II in still another example according to the present invention.

FIG. 7 is a cross-sectional view showing a laminated state of molding materials I and II in a comparative example.

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Claims (1)

[Claims] 1. A method of producing a thermosetting resin shaped article, comprising laminating two or more semi-solid molding materials containing a thermosetting resin and a fibrous reinforcing material, followed by heat-pressing. 1% by weight of 1 to 3.5 mm fibrous reinforcing material
A molding material containing less than 5% by weight is laminated on the visible surface side of the molded article, and a fibrous reinforcing material having a fiber length of 1 to 7 mm is added to 5 to 15
A method for producing a thermosetting resin irregularly shaped article, characterized by comprising laminating a molding material containing 20% by weight on the non-visible surface side of the molding.