JPH10128911A - Single board made of fiber reinforced resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form single boards made of fiber reinforced resin with a fine appearance by improving its weatherability and giving good transparency. SOLUTION: Formed on one frontal side of an SMC foundation material is a resin layer consisting of blending unsaturated polyester resin, low contracted resin, and aluminum hydroxide. The resin layer has a thickness of 0.5-5.0mm and permeability of rays of 30-48%. The refractive index of resin compound cured matter forming the resin layer is made to approximate to the refractive index of aluminum hydroxide. Also, the relation between the thickness [X](mm) of the resin layer and the permeability of rays [Y] is allowed to be in [Y]>=50-3.4 [X] (correlative coefficient (r)=0.986).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fiber-reinforced resin unit plate suitably used for a water tank, a hot water storage tank, a cooling tower, a wall panel and the like.

[0002]

2. Description of the Related Art Conventionally, a thermosetting resin such as an unsaturated polyester resin or a phenol resin, a low-shrinkage resin, a curing agent, and an inorganic filler such as calcium carbonate have been blended as a molding material for a unit plate made of fiber reinforced resin. It is known to use an SMC (sheet molding compound) in which a resin compound is impregnated into glass fiber as a fiber reinforcement. Molding of fiber reinforced resin unit plate is semi-cured SMC
Are laminated and placed on a mold, and then heated and pressed.

[0003]

A resin layer is formed on the surface of a fiber reinforced resin unit plate, and is a very thin layer containing an inorganic filler. In addition, it has a large amount of glass fiber as a fiber reinforcement near the resin layer. For this reason, surface defects are likely to appear unless special processing such as in-mold coating or surface coating after demolding is performed.

[0004] In other words, during molding, there are poor fluidity of SMC due to fiber reinforcing material, inorganic filler, hardener, etc., and phenomena such as insufficient surface gloss, generation of pinholes, and emergence of fibers and filler. Is likely to occur and the product value may be impaired.

[0005] Further, when used in a water tank, a cooling tower, or the like used outdoors, there is a deterioration due to natural exposure, and the emergence of glass fibers and the exposure of inorganic fillers occur. Furthermore, dirt and dust adhere to the uneven portions of the surface generated by these to cause contamination, and the appearance is impaired.
There is a problem that the life of the unit plate is shortened due to the deterioration of the portion.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a specific resin layer is formed on the surface of a fiber-reinforced resin unit plate to improve weatherability. It is an object of the present invention to provide a unit plate made of a fiber-reinforced resin having an excellent transparency and a beautiful appearance.

[0007]

SUMMARY OF THE INVENTION A glass fiber is impregnated with a resin compound containing a thermosetting resin such as an unsaturated polyester resin, a curing agent, and an inorganic filler such as calcium carbonate to form a semi-cured SMC. A unit plate made of a fiber-reinforced resin obtained by heating and press-molding a semi-cured SMC as a main component, and comprising, on at least one surface side, an unsaturated polyester resin, a low-shrinkage resin, and aluminum hydroxide. A resin reinforced resin unit plate, wherein the resin layer has a thickness of 0.5 to 5.0 mm and a light transmittance of 30 to 48%. It is.

Here, the semi-cured SMC is, for example,
Thermosetting resins such as isophthalic acid, terephthalic acid or bisphenol based resins, vinyl ester resins, epoxy resins, phenolic resins, etc., fillers such as calcium carbonate, curing agents, thickening of magnesium oxide etc. It is made by impregnating a resin compound containing an agent, etc., into chopping fiber of roving glass or other glass fiber or chopping fiber of carbon fiber. This is a so-called aged sheet-shaped molding material which has been thickened to a maximum.

The present invention relates to a semi-cured SMC as described above.
In a unit plate made of fiber-reinforced resin obtained by heating and pressing mainly with a resin layer formed on at least one surface side, a resin layer formed by blending an unsaturated polyester resin, a low shrinkage resin and aluminum hydroxide was formed. Wherein the resin layer has a thickness of 0.5 to 5.0 mm and a light transmittance of 30 to 48%.

In the present invention, the thickness of the resin layer is 0.1.
5 to 5.0 mm. If the thickness is less than 0.5 mm, it is difficult to form a uniform layer, and the appearance of the molded article cannot have the depth of appearance, which is a feature of the present invention, that is, transparency. If the thickness of the resin layer exceeds 5.0 mm, warpage due to a difference in shrinkage occurs on the resin layer side of the molded product, and the molded product is likely to be defective.

The resin layer has a light transmittance of 30 to 4.
8%. Here, the light transmittance means that a light beam is emitted from a light source on one side of a molded plate as a cured product of a resin compound obtained by blending an unsaturated polyester resin, a low-shrinkage resin, and aluminum hydroxide that form the resin layer. The amount of light transmitted through the molded plate and transmitted to the opposite side was measured, and is a percentage of the value obtained by dividing the light transmittance of the molded plate by the total light transmittance (based on the measurement reference sample). .

The resin layer in the present invention can be obtained by laminating a resin compound in which the cured product of the resin compound forming the resin layer has a refractive index close to that of aluminum hydroxide. Usually, for example, while the refractive index n of aluminum hydroxide is 1.57, the refractive index n of the cured resin compound is 1.56.
It is preferable to laminate the resin compound so that the thickness is about 1.55. The light transmittance increases due to the close refractive index. As the unsaturated polyester resin for the resin layer, unsaturated polyester resins such as isophthalic acid, terephthalic acid, bisphenol, and vinyl ester can be used.

When the resin layer is viewed as a compounding component, the unsaturated polyester resin 50 to 80 parts by weight, the low shrinkage resin 20 to
It is preferable to have 50 parts by weight and 150 to 250 parts by weight of aluminum hydroxide. Examples of the low-shrink resin include polymethyl methacrylate, polystyrene, polyvinyl acetate, and polyethylene resins.

A typical preferred composition of the above resin layer is exemplified by an unsaturated polyester resin (PS-H available from Hitachi Chemical Co., Ltd.).
9310) 60 parts by weight, low shrinkage resin (P
S-B9155) 40 parts by weight, aluminum hydroxide 25
0 parts by weight.

This resin layer has a thickness [X] (mm)
And the light transmittance [Y], the thickness [X] of the cured product (molded plate) of the resin compound forming the resin layer
FIG. 1 is a graph showing the relationship between the light transmittance and the light transmittance [Y]. As is apparent from the figure, the light transmittance at a thickness of 5 mm is 30%, and the relationship between the thickness [X] and the light transmittance [Y] changes linearly.
Formula [Y] = 50-3.4 [X] (correlation coefficient r = −0.9
86).

That is, in the present invention, the resin layer formed on at least one surface side of the fiber reinforced resin unit plate has a thickness of 0.5 to 5.0 mm and a light transmittance of 30 to 48. %, And more preferably the thickness [X].
(Mm) and the light transmittance [Y], [Y]
≧ 50−3.4 [X] (correlation coefficient r = −0.986). However, in practice, the value calculated by this formula should not be interpreted strictly mathematically and does not exclude an equivalent range.

The fiber-reinforced resin unit plate according to the present invention comprises:
A method in which the above-mentioned resin compound containing the unsaturated polyester resin is placed on the surface of the cured SMC molded product and heated and pressurized, and the above-mentioned resin compound containing the unsaturated polyester resin is made into a sheet and formed on the semi-cured SMC surface. It is manufactured by a method of heating and pressurizing by overlapping. S
When laminating the resin compound on the surface of the MC molded cured product, the surface of the molded cured product should be sanded in advance, or the surface should be made uneven so as to increase the adhesiveness. SM
The C base material can be manufactured by a known composition and method. Usually, the thickness of the SMC is about 3.5 to 13 mm, but it is appropriately implemented as needed and is not particularly limited.

[0018]

【Example】

Example 1 Unit plate for water tank (size: 1000 × 1
000 mm, weight 15 kg), first, a semi-cured SMC substrate was prepared by a conventional method using a resin compound having the following composition and chopping fiber (content: 30% by weight) of roving glass.

[Composition of SMC base material] Unsaturated polyester resin (isophthalic acid-based polyester resin) 80 parts by weight Low shrinkage resin 20 parts by weight Curing agent (t-butyl peroxybenzoate) 1 part by weight Internal release agent (stearin Zinc acid) 5 parts by weight Filler (calcium carbonate) 120 parts by weight Pigment 3 parts by weight

Next, the SMC base material is cut into a predetermined size to form five sheets, placed in a mold, heated and pressed, and formed into a shape having flanges (height 70 mm) standing on four sides. A unit plate was formed. Molding is performed at a mold temperature of 135.
C., a molding pressure of 50 kg / cm ² , and a pressure holding time of 7 minutes.

Further, the surface of the unit plate obtained as described above is sanded and roughened, and the refractive index of the cured product of the resin compound is close to the refractive index of aluminum hydroxide as the filler. Was placed and heated and pressed under the above-mentioned molding conditions to obtain a fiber-reinforced resin unit plate having a surface resin layer (thickness: 2 mm) having excellent transparency. The light transmittance of the cured product of the resin compound was 30% at a thickness of 5 mm (the measuring device used was a turbidimeter # 80 manufactured by Nippon Denshoku Co., Ltd.).

[Composition of Resin Compound] 60 parts by weight of unsaturated polyester resin (PS-9310 manufactured by Hitachi Chemical Co., Ltd.) 40 parts by weight of resin with low shrinkage (PS-B9155 manufactured by Hitachi Chemical Co., Ltd.) 250 parts by weight of aluminum hydroxide

Example 2 First, a semi-cured SMC substrate was prepared in the same manner as in Example 1 by a conventional method.

Next, the SMC base material was cut into a predetermined size to form five sheets, and a sheet (1 sheet) of a resin compound having the following composition was stacked thereon, and placed in a mold. Heat, pressurize, and stand upright on four sides (height 7
(0 mm). The molding conditions were the same as in Example 1.

[Composition of Resin Compound] Unsaturated polyester resin (PS-9310, manufactured by Hitachi Chemical Co., Ltd.) 60 parts by weight Low-shrink resin (PS-B9155, manufactured by Hitachi Chemical Co., Ltd.) 40 parts by weight 250 parts by weight of aluminum hydroxide

The above resin compound is formed into a sheet by applying a thickener (magnesium oxide, 0.8 parts by weight) to the above resin compound, applying it to a polypropylene film and heating and aging it. This was performed by preparing a sheet of the resin compound formed into a sheet in the above.

Thus, a fiber-reinforced resin unit plate having a surface resin layer (thickness: 2 mm) whose outer surface was excellent in transparency was obtained. The light transmittance of the cured product of the resin compound was 30% at a thickness of 5 mm (the measuring device used was a turbidimeter # 80 manufactured by Nippon Denshoku Co., Ltd.).

[0028]

According to the conventional unit plate, the molding surface of the base material SMC has the appearance as it is, but according to the present invention, a specific resin layer is formed on the surface of the fiber reinforced resin unit plate, Improves weather resistance by avoiding exposure of glass fiber and inorganic fillers due to natural exposure that easily occurs on the unit plate, and preventing dust and dirt from adhering to irregularities on the surface caused by these exposures. Can be done.

Further, the coating layer has a glossy surface, and the coating layer is excellent in transparency regardless of its thickness. A marble pattern or the like formed by partially flowing a pigment into the transparent resin layer or adding natural stone or decorative powder can be made more beautiful.

[Brief description of the drawings]

FIG. 1 is a graph showing a relationship between a thickness [X] of a cured product of a resin compound forming a resin layer and a light transmittance [Y].

Claims (3)

[Claims] A glass fiber is impregnated with a resin compound containing a thermosetting resin such as an unsaturated polyester resin, a curing agent, and an inorganic filler such as calcium carbonate to form a semi-cured SMC. Heating mainly SMC,
In the unit plate made of fiber reinforced resin obtained by pressure molding,
On at least one surface side, an unsaturated polyester resin,
A resin layer formed by mixing a low-shrinkage resin and aluminum hydroxide, wherein the resin layer has a thickness of 0.1 mm.
A fiber-reinforced resin unit plate having a thickness of 5 to 5.0 mm and a light transmittance of 30 to 48%. 2. The resin layer is formed by laminating resin compounds in which the refractive index of a cured product of the resin compound forming the resin layer is close to the refractive index of aluminum hydroxide. The fiber reinforced resin unit plate according to claim 1. 3. The resin layer has a thickness [X] (mm) and a light transmittance [Y] of [Y] ≧ 50-3.
The fiber reinforced resin unit plate according to claim 1 or 2, wherein 4 (X) (correlation coefficient r = -0.986).