JPH1015969A - Manufacturing method of decorative molded products - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative molded product which can be processed with excellent appearance quality by supplying a decorative sheet to a predetermined position of a mold accurately and in close contact without wrinkling. A manufacturing method is provided. A decorative sheet (3) is supplied to a lower mold (2) of a mold (10) comprising an upper mold (1) and a lower mold (2). A molding compound (4) is supplied from above, and the upper mold (1) is closed and heated. The surface is decorated by pressing, and in the method of manufacturing a decorative molded product to be a molded product in which a thick portion is formed on the back side of the decorative portion, provided for forming the thick portion. The molding is performed by setting the heating temperature of the concave portion 11 of the upper mold 1 to a temperature higher by 15 ° C. to 75 ° C. than the peripheral heating temperature except the concave portion 11.

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 decorative molded product whose surface is decorated with a pattern or the like.

[0002]

2. Description of the Related Art Conventionally, in the production of bathtubs, bath unit floors and the like using FRP which is a glass fiber reinforced plastic, molding methods such as a hand-up molding method or a spray-up molding method have been widely used. In these molding methods, since each product is performed almost in a state close to a manual operation, time and work man-hours are extremely large, and productivity is poor.

As a molding method for improving the productivity of this FRP product, a molding compound such as a shield molding compound (hereinafter abbreviated as SMC) or a bulk molding compound (hereinafter abbreviated as BMC) has been developed. Press molding using this molding compound is very widely used at present.

[0004] However, the molded product obtained by press molding using the molding compound as described above has a disadvantage that the color of the product is limited to a single color and the design of the color is poor.

As a method for solving the above-mentioned disadvantage, a post-process such as a secondary processing can be separately added. For example, a so-called additional process such as multi-coloring by printing, painting, etc., or giving a pattern is used. Although it is possible to decorate, there is a problem that a complicated work process is required and productivity is poor.

[0006] As a method for improving the method of decorating such a molded article, a press molding method using a decorating sheet impregnated with a thermosetting resin or the like has been proposed. This is a method of laminating a substrate, such as a glass cloth, a glass mat, a nonwoven fabric, or a woven fabric, on which a pattern is printed, on the SMC.

In Japanese Patent Application Laid-Open No. 5-285973, a printed titanium paper impregnated with a thermosetting resin is used, and the upper surface of a lower die of a press molding die composed of an upper die and a lower die is used. (To be a surface of a product), and then supply SMC from above and heat-compress molding to form a so-called decorative molded product having a decorated surface.

[0008]

However, in the conventional method of manufacturing a decorative molded product described in Japanese Patent Application Laid-Open No. 5-285973, when the molded product has a thick part, In addition to the problem that minute irregularities are generated on the decorative surface of the thick portion, the gloss of the portion is deteriorated and the appearance and design are poor, and the surface of the portion is easily contaminated.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to solve these problems and to provide a thick portion on the back side of the decorative surface of a product. Even if there is, there is provided a method for producing a decorative molded article that can be formed with excellent appearance quality without generation of minute irregularities on the decorative surface.

[0010]

According to the first aspect of the present invention, a decorative sheet is supplied to a lower mold of an upper mold and a lower mold. The molding compound is supplied from above, and the surface is decorated by closing and heating and pressing the upper mold, and a thick part is formed on the back side of the decoration part. Wherein the heating temperature of the concave portion of the upper die provided for forming the thick portion is set to a temperature higher by 15 ° C. to 75 ° C. than the heating temperature of the periphery other than the concave portion. And

In the method for producing a decorative molded article according to the present invention, a decorative sheet is supplied to a lower mold of an upper mold and a lower mold, and then a molding compound is supplied from above. In the method of manufacturing a decorative molded product, the surface is decorated by supplying, closing the upper mold and heating and pressing, and the thick portion is formed on the back side of the decorative portion. The molding is performed using a molding compound having a ratio of 0.1% or less.

As the decorative sheet used in the method for producing a decorative molded article of the present invention, a printing base material is impregnated with a thermosetting resin, and a dried prepreg sheet or a base material is impregnated with the thermosetting resin. A known conventional material such as a semi-cured or thickened sheet can be used. Examples of the substrate include various papers such as titanium paper, coated paper and art paper having a basis weight of 10 to 300 g / m ² , glass mats, and nonwoven fabrics and woven fabrics of synthetic fibers such as nylon and polyester. Is used.

The amount of the thermosetting resin impregnated in the base material is preferably 30 to 70% by weight, more preferably 40 to 60% by weight of the total weight after impregnation. .

The printing of a picture (pattern) or the like on a base material to be used as a decorative sheet can be performed by conventional gravure, offset, screen, letterpress printing, and the like. Conventionally known fibers such as fibers colored with dyes are used.

As the ink for printing, for example, those based on resins such as thermosetting type melamine resin, phenohill resin, unsaturated polyester resin, two-pack type acrylic urethane and polyester urethane are preferably used. . The ink is used by appropriately kneading a colorant such as a pigment or a dye, a plasticizer, a stabilizer, a filler, a solvent, and the like, as necessary, with the base resin. Furthermore, in order to improve the appearance and design, granulated particles of thermosetting resin products, natural mica, colored mica, cold water stone, natural stone powder, shell, metal powder and other pattern materials, pigments, dyes, etc. are added. Is also good.

As a method of manufacturing a decorative sheet, a base material is immersed in a tank containing an impregnating resin, the resin is impregnated, excess resin is dropped by a roll or the like, and a drying oven is used if necessary. Or by flowing a base material on a belt, placing an impregnating resin on the base material, and squeezing with a roll or a blade.

In the present invention, various molding compounds such as SMC and BMC can be used. For example, as these thermosetting resins, unsaturated polyester resins, epoxy acrylate resins, urethane acrylate resins, etc. are used, and various fillers, reinforcing materials, additives, etc. are added as necessary, and SMC, BMC, etc. Is used as a thermosetting resin composition having the form of

[0018] The molding material of the thermosetting resin composition may contain, as a low-shrinking agent, polyvinyl acetate, polymethyl (meth) acrylate, polyethylene, ethylene-vinyl acetate copolymer, vinyl acetate-styrene copolymer. Thermosetting resins such as polybutadiene, saturated polyesters and saturated polyethers can be used in an appropriate amount as required.

Further, if necessary, an appropriate amount of a polymerizable monomer such as styrene, alpha methylene styrene, divinylbenzene, vinyltoluene, diallyl phthalate, various acrylate monomers and various methacrylate monomers may be added to the above molding material. it can. Among them, styrene and methyl methacrylate are preferable because they are excellent in price and various performances.

In the above molding material, an organic peroxide as a radical reaction initiator can be used if necessary. For example, ketone peroxides such as methyl ethyl ketone peroxide, and tertiary butyloxybenzoate, tertiary butyl peroxyisopropyl carbonate, and the like can be generally used.

When the above-mentioned thermosetting resin is used, if the amount used is too large, the viscosity of the molding material becomes high, resulting in poor moldability. If the amount is too small, cracks are generated. The content is preferably 0.1 to 30% by weight, more preferably 0.3 to 20%.

When the above-mentioned organic peroxide is used,
The amount is preferably 0.3 to 5 parts by weight, more preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the total of the thermosetting resin having a reactive unsaturated bond and the copolymerizable monomer. If the amount used is too small, the curing speed of the molding material becomes slow,
On the other hand, if the amount is too large, the molding material may turn yellow during curing.

Further, a thickener is added to the molding material. As the thickener, oxides or hydroxides of alkaline earth metals such as magnesium and calcium can be used. For example, magnesium oxide, magnesium hydroxide and the like can be mentioned. The amount of the thickener is 1.0 to 5.0 parts based on 100 parts by weight of the resin component. If the amount is too small, the resin viscosity is too low, and the handleability will deteriorate, such as dripping of the resin or the viscosity will increase.If the amount is too large, the viscosity of the molding material will be too high and the fluidity in the mold will be insufficient. Problems such as underfilling occur.

The molding material may contain an appropriate amount of an inorganic filler, for example, calcium carbonate, clay, aluminum hydroxide, barium sulfate, graphite, etc., according to the purpose and application. As the amount of the filler,
It is 10 to 100 parts by weight based on 100 parts by weight of the resin component. If the amount is too small, the resin viscosity is too low, and the handleability will deteriorate, such as dripping of the resin or the viscosity will increase.If the amount is too large, the viscosity of the molding material will be too high and the fluidity in the mold will be insufficient. Problems such as underfilling occur.

Further, various reinforcing fibers such as glass fiber and carbon fiber can be added to the molding material in an appropriate amount as a reinforcing material. The amount of the reinforcing material used is 100
It is preferably from 10 to 250 parts by weight, more preferably from 20 to 200 parts by weight, based on parts by weight. If the content is too small, a sufficient reinforcing effect cannot be obtained. If the content is too large, the reinforcing material floats on the surface of the product, and the appearance is impaired.

As the molding machine used in the present invention, a conventional press molding machine can be used, and the molding dies include not only a conventional upper and lower mold, but also a casting mold and the like. Can also be used.

As the form of the molding die, a die composed of an upper die and a lower die is preferably used, and a decorative sheet is supplied to the lower die to form a thick portion on the upper die side. Good to do.
The thick portion refers to a reinforcing portion generally provided in a molded product, and includes, for example, a boss for an embedded screw and a reinforcing rib for preventing strength and deformation.

As a method of heating the thick portion, for example, a method of forming a mold of the thick portion by a separate block and heating by a separate heater, or a method of projecting a pin protruding into a concave portion forming a boss portion or the like. Is provided, a method of separately heating the projecting pin or the like is used.

In the manufacturing method according to the present invention, dies (upper and lower dies) are attached to a press molding machine, and
It is characterized by heating to 0 ° C., for example, heating the periphery of the concave portion forming the thick portion to a temperature higher by 15 to 75 ° than the heating temperature of the concave portion. In this case, if the difference between the temperature around the thick portion and the temperature between the thick portion is less than 15 ° C., the occurrence of minute irregularities on the surface of the decorative molded product cannot be prevented, and the temperature difference is more than 75 ° C. If it is large, the surface of the decorative molded product may be swollen.

Further, the temperature around the thick portion is preferably heated to 110 to 200 ° C. while maintaining the above temperature difference. When the temperature is lower than 110 ° C., the occurrence of minute irregularities on the surface of the decorative molded product cannot be prevented, and when it is higher than 200 ° C., the surface of the decorative molded product may be swollen.

The heating conditions for the mold and the like are set, and
Supply the decorative sheet to the lower mold, and subsequently supply the molding compound, press-mold at a molding pressure of ² to 150 kg / cm ² for 30 to 15 minutes, and after curing, open the mold and perform molding. Can be completed.

The molding pressure in the above molding process is preferably 50 to 120 kg / cm ² when using SMC or BMC which is a molding compound, and when using so-called low pressure SMC, 5-25k
g / cm ² is preferred. In this case, if the molding pressure is too low, sufficient fluidity of the molding material cannot be obtained, and if the molding pressure is too high, there is a problem that deterioration of the mold during mass production is apt to progress.

[0033]

In general, molding compounds such as SMC and BMC are completely filled in a mold and then expanded by the generation of reaction heat of a curing reaction (radical polymerization). Thereafter, shrinkage occurs due to volume shrinkage due to the phase change and temperature decrease due to the stop of the curing reaction. At this time, since the surrounding flat portion is thinner than the thick portion, the volume shrinkage due to the phase change of the molding compound and the shrinkage due to the temperature change are smaller than the thick portion. For this reason, after shrinkage of the thick part,
Only the surrounding flat portion receives pressure, and the pressure of the thick portion decreases, which causes minute unevenness after molding in this portion.

In the manufacturing method according to the first aspect of the present invention, the heating temperature of the concave portion provided for forming the thick part of the upper die is set at 15 ° from the surrounding heating temperature other than the concave portion.
Heating and expansion of the thick portion of the molded product formed by the concave portion can be increased by molding at a temperature set to ~ 75 ° higher, and shrinkage accompanying the stop of the curing reaction by heating can be increased. This can be reduced by minimizing the decrease in pressure of the portion, and the occurrence of minute irregularities on the surface of the thick portion can be prevented.

In the manufacturing method according to the first aspect of the present invention, by using a molding compound having a shrinkage of 0.1% or less, the curing shrinkage of the molding compound can be suppressed to a very small value. The pressure drop in the thick part is reduced, and the occurrence of minute irregularities on the surface of the thick part can be prevented.

[0036]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of a molding die used in the method of manufacturing a decorative molded product according to the present invention. This embodiment is an example of a waterproof pan made of FRP. In FIG. 1, the mold 10 is composed of an upper mold 1 and a lower mold 2, and a concave portion 11 for a boss formed as a thick portion is provided inside (molding side) of the upper mold 1. I have. Also, lower mold 2
A decorative pattern 21 (embossing or the like) forming the decorated surface of the molded product is provided on the upper surface (decorative molding side) of the molded product.

The decorative sheet 3 is provided on the upper surface of the decorative pattern 21.
Then, the molding compound 4 is supplied, pressure molding is performed, and the mold is opened after curing, thereby having a decorative molding surface 31 on the surface as shown in FIG. The molded product 30 provided with the thick projection 32 for the boss is obtained.

A press molding machine (1500 tons, manufactured by Kawasaki Yuko Co., Ltd.) is used for molding the molded product 30 shown in FIG.
A waterproof pan having a size of 166 cm × 116 cm was molded. Both the upper and lower molds of the metal mold were buried with the above-mentioned piping for heating, and the upper mold was provided with a plurality of concave portions for forming a boss, and a protruding pin having a heater embedded at the center thereof.

The decoration sheet 4 was adjusted as follows. 1) Preparation of resin solution for impregnation (1) Unsaturated polyester resin solution Dissolve an isocyanate-based, unsaturated polyester resin having a number average molecular weight of about 8300 in acetone and toluene solvent (1: 1), solvent 35% by weight 100 parts by weight. (2) Curing agent 3 parts of t-butyl peroxyisopropyl carbonate The above (1) and (2) were mixed and stirred to obtain a resin solution for impregnation.

2) Adjustment of decorative sheet Sheet 1: Titanium paper (0.1 mm thick, 80 g / m ² ,
80 with a stone pattern printed on PM11P Kojinsha
After being cut into a size of × 100 cm and immersed in the resin solution to impregnate the resin, excess resin was removed by a roll and dried to obtain an impregnated sheet. The content of the base material (paper) of the obtained decorative sheet was 50% by weight.

Sheet 2: non-woven fabric (polyester, thickness 0.36 mm, 40.7 g / m ² , Sontara # 8000
A decorative sheet was obtained in the same manner as in Sheet 1, except that a stone pattern was printed on Toray DuPont. The content of the base material (paper) of the obtained decorative sheet was 50% by weight.

Sheet 3: overlay paper (thickness 0.12)
mm, 100 g / m ^{2 (} manufactured by Kojin Co., Ltd.), and a decorative sheet was obtained in the same manner as sheet 1, except that a stone pattern was used. The content of the base material (paper) of the obtained decorative sheet is 4
It was 5% by weight.

The molding material used was prepared as follows. (1) Unsaturated polyester resin solution (isophthalic acid-based unsaturated polyester resin having a number average molecular weight of about 2,000 dissolved in styrene, styrene concentration 40% by weight)
70 parts by weight (2) Polystyrene resin solution (weight average molecular weight of about 9500
0 polystyrene resin dissolved in styrene, styrene concentration 65% by weight) 30 parts by weight (3) Curing material (tertiary butyl peroxybenzoate) 1 part (4) Calcium carbonate powder (NS-100 manufactured by Nitto Powder Chemical Co., Ltd.) 120 parts (5) Color pigment (titanium oxide powder SR-1 manufactured by Sakai Chemical Industry Co., Ltd.) 6 parts (6) Thickener (magnesium oxide powder Kyowa Mag 1)
50 Kyowa Chemical Industry Co., Ltd. 1 part (7) Internal release agent (Zinc Stearate Sakai Chemical Industry Co., Ltd.) 3 parts (8) Glass fiber (Roving ER4630LBD166W manufactured by Asahi Fiberglass Co., Ltd. cut into 25 mm, below) GF) 70 parts Of the above compounded materials, after mixing and sufficiently kneading the compounded materials of (1) to (7), impregnating the glass fiber of (8) with an SMC manufacturing device, and 24 hours at 40 ° C. Aging time, thickness 2m
m colored white SMC were obtained.

Further, the following were prepared as molding materials. SMC-1: Polymer Lumat 9000 Shrinkage 0.0
035% (manufactured by Takeda Pharmaceutical Company Limited) SMC-2: Polymer Rumat 683 Shrinkage 0.14
9% (manufactured by Takeda Pharmaceutical Company Limited) SMC-1: Polymer Lumat 609 Shrinkage 0.22
5% (manufactured by Takeda Pharmaceutical Company)

(Example 1) Using the above molding material and decorative sheet, molding was performed as follows. 135 upper mold
After heating the lower mold at 145 ° C. and the protrusion pin of the recess for forming the boss at 175 ° C., the sheet 1 of the decorative sheet is supplied onto the decorative pattern of the lower mold, and the colored SMC is placed thereon. Is supplied, and the upper die is 50 mm / sec up to 30 mm above the position where it contacts the SMC, 8 mm / sec from the position 30 mm above the position where it contacts the SMC to the position where it contacts the SMC, and 1 mm until the upper die is closed after contacting the SMC The upper mold was closed at respective speeds of / kg / sec. After the mold was clamped, pressure molding was performed at a pressure of 70 kg / cm ² for 240 sec. Thereafter, the mold was opened to obtain a molded product whose surface was decorated.

(Examples 2 to 7) Using the above-mentioned sheets 1 to 3, molding was performed in the same manner as in Example 1 above, with the protrusion pins of the concave portions and the heating temperature of the upper die set to the values shown in Table 1. . (Examples 8 to 10) Using the above-described sheets 1 to 3, molding was performed in the same manner as in Example 1 above, using SMC-1 as a molding material.

(Comparative Examples 1 to 5) Using the above-mentioned sheets 1 to 3, the molding temperature was set to the values shown in Table 1 by setting the protrusion pins of the concave portions and the heating temperature of the upper die to the same values as in Example 1 above. . (Comparative Examples 6 to 11) Using the above-described sheets 1 to 3, molding was performed in the same manner as in Example 1 using SMC-2 to SMC-3 as molding materials.

The above results are shown in Table 1 for Examples 1 to 7, Table 2 for Comparative Examples 1 to 5, Table 3 for Examples 8 to 10, and Table 4 for Comparative Examples 6 to 11. Was. Tables 1 to 4 show the results of visually evaluating the appearance of the decorative surface around the boss of the molded article obtained as described above.

[0049]

[Table 1]

[0050]

[Table 2]

[0051]

[Table 3]

[0052]

[Table 4]

As shown in the molding method according to the present invention shown in FIG. 3, by heating the protruding pin provided in the concave portion for the boss, the thickness is increased as compared with the conventional unheated molding method shown in FIG. It has been confirmed that the pressure of the meat portion can be kept low until the molding is completed while the pressure of the meat portion is kept small, and as a result, the occurrence of minute irregularities can be prevented.

Further, it was confirmed that the use of the low-shrinkage SMC as the molding material allows the pressure in the thick portion to be sufficiently maintained until the completion of the molding, as compared with the conventional ordinary SMC.
Therefore, it has become possible to manufacture a decorative molded product that can reliably prevent the occurrence of minute irregularities on the decorative surface on the surface of the thick portion.

[0055]

According to the first aspect of the present invention, the heating temperature of the concave portion provided for forming the thick product portion of the upper die is set to be 15 degrees lower than the heating temperature of the surrounding area other than the concave portion.
By molding at a high temperature of 75 ° to 75 °, the heat generation and expansion of the thick portion of the molded product formed by the concave portion can be increased, and the shrinkage accompanying the stop of the curing reaction can be increased by heating. By reducing the decrease in the pressure of the thick portion, the pressure can be reduced, and the occurrence of minute irregularities on the surface of the thick portion can be prevented.

In the manufacturing method according to the first aspect of the present invention, by using a molding compound having a shrinkage of 0.1% or less, the curing shrinkage of the molding compound can be suppressed to a very small value. The pressure drop in the thick part is reduced, and it is possible to prevent the occurrence of minute irregularities on the surface of the thick part. Therefore,
It is suitably used as a method for manufacturing a decorative molded product.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a molding die used in a method for producing a decorative molded product according to the present invention.

FIG. 2 is a sectional view of a molded product.

FIG. 3 is a pressure-molding time curve of the molding method according to the present invention.

FIG. 4 is a pressure-molding time curve of a conventional molding method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 mold 1 upper mold 11 concave portion 21 decorative pattern 30 molded product 31 decorative molding surface 32 convex portion

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] February 28, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0023

[Correction method] Change

[Correction contents]

Further, a thickener is added to the molding material. As the thickener, oxides or hydroxides of alkaline earth metals such as magnesium and calcium can be used. For example, magnesium oxide, magnesium hydroxide and the like can be mentioned. The amount of the thickener is 1.0 to 5.0 parts by weight based on 100 parts by weight of the resin component.
If the amount is too small, the resin viscosity is too low, so that the resin drips and the handleability deteriorates.If the amount is too large, the viscosity of the molding material becomes too high and the fluidity in the mold becomes insufficient. Problems such as underfilling occur.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction contents]

An appropriate amount of an inorganic filler, for example, calcium carbonate, clay, aluminum hydroxide, barium sulfate, graphite, or the like can be added to the molding material according to the purpose and application. As the amount of the filler,
It is 10 to 100 parts by weight based on 100 parts by weight of the resin component. If the amount is too small, the resin viscosity is too low, and the resin drips.
If the handleability is poor, and if the amount is too large, the viscosity of the molding material becomes too high, the fluidity in the mold is insufficient, and problems such as underfilling occur.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0044

[Correction method] Change

[Correction contents]

Further, the following were prepared as molding materials. SMC-1: Polymer Lumat 9000 Shrinkage 0.0
035% (manufactured by Takeda Pharmaceutical Company Limited) SMC-2: Polymer Rumat 683 Shrinkage 0.14
9% (manufactured by Takeda Pharmaceutical Co., Ltd.) SMC- 3 : Polymer Lumat 609 Shrinkage 0.22
5% (manufactured by Takeda Pharmaceutical Company)

Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display B29L 9:00

Claims (2)

[Claims] 1. A decorative sheet is supplied to a lower mold of a mold composed of an upper mold and a lower mold, and then a molding compound is supplied from above, and the upper mold is closed and heated and pressurized to form a surface. In the method of manufacturing a decorative molded product which is decorated and has a thick portion formed on the back side of the decorative portion, heating the concave portion of the upper die provided for forming the thick portion. The temperature is 15 ° C. higher than the surrounding heating temperature except for the concave portion.
A method for producing a decorative molded product, wherein the molding is performed at a temperature set to a temperature higher by 75 ° C. 2. A decorating sheet is supplied to a lower mold of a mold composed of an upper mold and a lower mold, and then a molding compound is supplied from above, and the upper mold is closed and heated and pressurized to form a surface. In the method for manufacturing a decorative molded product which is a molded product which is decorated and has a thick portion formed on the back side of the decorative portion, molding is performed using a molding compound having a shrinkage of 0.1% or less. A method for producing a decorative molded product, characterized by comprising: