JPH0136418B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a molded article with a desired pattern, and in particular to FRP, which is molded at room temperature or near room temperature using a radical curing resin. This applies to molded products.

The purpose of the present invention is to apply molded products such as FRP and cast products that have rarely been painted or to which only simple post-printing or limited hand-drawn patterns can be applied. The purpose is to freely attach desired patterns to completely change the appearance and significantly improve the commercial value of the product.

Conventionally, methods for painting molded products such as FRP and cast products include methods such as heat transfer, sublimation transfer, and direct printing, methods of directly inserting printed paper or printed nonwoven fabric during molding, or Techniques such as hand-drawing patterns on gel coats have been used.

However, the appearance of molded products obtained by these existing methods is simple and lacks commercial value, lacks depth and gives a cheap feel, or the fibers of the nonwoven fabric are noticeable. It had some flaws and was not always satisfactory.

The present inventors have improved the conventional painting methods for molded products such as FRP and cast products, and obtained molded products that are superior in appearance to molded products obtained by conventional methods. As a result of various studies for this purpose, the present invention has been completed.

That is, in the present invention, when a radical curing resin or a radical curing resin and a fibrous reinforcing material are cured, a film or a foamed sheet soluble in the resin is used at an uncured stage when the resin is liquid or sticky. A film or foam sheet on which a desired pattern is printed using printing ink is brought into close contact with the resin surface so that the pattern side is in contact with the resin surface, and the film or foam sheet is dissolved in the resin and the pattern is transferred to the resin surface to remove the resin. The present invention relates to a method for producing a decorated molded article, which is characterized by curing and then painting the transferred pattern surface with a transparent or semi-transparent paint.

In the molded product obtained by the method of the present invention, the pattern is painted using a method different from conventional post-printing or non-woven fabric painting, so the pattern is sandwiched between the paint and the hardening resin. shape, and the transparency, reflectance, and degree of coloration of the upper and lower resin layers can be changed depending on the location, making it different from molded products obtained by the conventional simple printing method. It is possible to get rid of the so-called cheap appearance and the conspicuousness of the fibers of the nonwoven fabric, and to give it a much better appearance.

For example, either the resin layer above or below the pattern layer,
Alternatively, the use of resin mixed with glass beads in both resin layers is one example of this.

In other words, the present invention is not just a method of painting;
The emphasis is on beauty that gives the molded product a sense of luxury.

The radical curable resin used in the present invention can be broadly classified into the following types.

(i) Unsaturated polyester resin containing α-β unsaturated polybasic acid as one component,
A type in which an unsaturated alkyd obtained by esterification reaction with a polyhydric alcohol is dissolved in a monomer modified with any saturated acid and/or unsaturated acid.

(ii) Vinyl ester resin A type in which a resin produced by the reaction between an epoxy resin and an unsaturated monobasic acid is dissolved in a monomer.

Acrylic acid or methacrylic acid is generally used as the unsaturated monobasic acid, and can be said to be a type of unsaturated acrylate resin.

(iii) Unsaturated acrylate resin One acryloyl group or methacryloyl group
Examples include polyurethane, polyester, spiroacetal, polyether, etc. containing one or more polyesters in the molecule. Of course, each of the resins (i) to (iii) can be used in combination as necessary.

Commercially available polyhydric alcohols and polybasic acids, which are raw materials for unsaturated polyester resin synthesis, may be used as they are, and there is no need to impose any particular restrictions on their composition.

In addition, the epoxy resin component constituting the vinyl ester resin does not need to be particularly limited, and commonly used bisphenol to diglycidyl ether types, novolak to polyglycidyl ether types,
It is selected as necessary from glycidyl ester types of polybasic acids, intramolecular glycidyl group acids obtained by peracetic acid oxidation, and the like.

There are limited synthesis methods and raw materials for unsaturated acrylate resins depending on their structure. For example, polyurethane-acrylate is mainly composed of diisocyanate, unsaturated alcohol, and polyol, and polyester-acrylate is directly esterified from acrylic acid or methacrylic acid and polyhydric alcohol or polybasic acid in the presence of an acid catalyst. Synthesized by

Although there are no particular restrictions on the type of fibrous reinforcing material used together with the radical curable resin, glass fiber is preferred from a practical standpoint. The ratio of radical curing resin and fibrous reinforcing material is generally 90:10~
It's 50:50.

A filler may or may not be used, but it is often better to use it because it changes the appearance of the molded product and makes molding easier. However, it cannot be used if transparency is required for the molded product. Typical examples of fillers include calcium carbonate, clay, hydrated alumina, fly ash, and the like.

In order to cure the radical curable resin, a curing agent and, if necessary, an accelerator are naturally added to the resin.

In order to apply a pattern to a film or foam sheet soluble in the radical curable resin used in the present invention, depending on the type of the pattern, it is necessary to carefully examine the type of printing ink that makes up the pattern, especially the type of binder (vehicle). Become. For example, if the pattern does not have clear lines, such as some types of stone,
There is no need to place any particular restrictions on the type of printing ink, but if even the slightest distortion of the pattern is unacceptable,
The types of vehicles are limited. From a practical standpoint, it is desirable to use a vehicle that does not disturb the pattern even if the printed film or foam sheet is kept in contact with the uncured resin for a long time, or even when the film or foam sheet is dissolved.

With this in mind, preferred polymers or oligomers constituting the printing ink vehicle include the following types: That is, specific examples thereof include, for example, styrene-maleic acid copolymer, polymer or oligomer obtained by adding a third component to styrene-maleic acid, polyamide resin, polybutene, xylene resin, chlorinated rubber, petroleum resin, 100 % alkylphenolic resin,
Examples include oil-modified phenolic resins, ketone resins, ester gums, rosin-maleic acid resins, rosin-modified phenolic resins, oil-modified alkyd resins, dry natural oils and polymerized oils, epoxy resins, cellulose derivatives, and the like. In addition to the above, although it is a water-based ink, the dried film exhibits lipophilic properties. polymer latex,
Alternatively, it is possible to use polymers that are both water-soluble and soluble in organic solvents, such as methyl cellulose, hydroxyethyl cellulose, methyl hydroxypropyl cellulose, polyvinylpyrrolidone, and polyvinyl methyl ether.

In particular, inks made by adding colorants to organic solvent-soluble polymers, which are not commonly used in printing inks, can be used either by printing or hand-painting.

Furthermore, photocurable vehicles, which have been increasingly used in recent years, can also be used. They mainly consist of unsaturated acrylate resins, i.e., alkyd acrylates, vinyl ester resins (epoxy acrylates), and urethane acrylates, with the necessary amount of polyacrylate polyhydric alcohol added thereto, and a photosensitizer added. is the main thing.

There are no particular restrictions on the use of the colorant, which is the other component of the ink.

Furthermore, printing as used in the present invention means applying a desired pattern to a film or a foam sheet by a machine or by hand.

The material of the film or foam sheet used in the present invention is not particularly limited as long as it is soluble in the radical curing resin;
Generally, polystyrene, copolymerized polystyrene, polycarbonate, ethylene-vinyl acetate copolymer, etc. are used. The film or foam sheet on which the pattern is printed is brought into close contact with the printed surface of the radical-curing resin in an uncured stage when the resin is in a liquid or sticky state so that the printed surface is in contact with the resin surface. Thus,
A film or foam sheet with a printed pattern is dissolved in a radical curing resin, and a cured product with the pattern transferred to the resin is obtained.

Although conventional molding methods can be applied to the method of the present invention, it is preferable to use a mold when manufacturing the molded article.

Although a mold is not necessarily required when manufacturing an FRP molded product using a mold, it is preferable to use a mold when manufacturing a cast product. The type is
Any ordinary material can be used, and any shape can be used. If a mold having an uneven surface is used, a molded product having a corresponding uneven pattern, oil surface, etc. can be obtained.

According to the method of the present invention, since a printed film or foamed sheet that is soluble in a radical-curable resin is used, by the time a cured product is obtained, the film or foamed sheet has almost completely become a radical-curable resin. Therefore, it has the advantage that the step of peeling off a film or foam sheet insoluble in radical curable resin from the cured product, which is required in the conventional method, can be omitted.

In the present invention, it is necessary to further coat the patterned cured resin surface with a transparent or translucent paint.

The paint for this purpose may be the same type as the resin mentioned above that constitutes the FRP molded product or cast product, but there are also other paints such as polyurethane paint, epoxy resin paint, acrylic resin paint,
It is also possible to use a group of paints called so-called clear lacquers, such as cellulose ester paints, and various photocurable paints can also be used as those that can best exhibit their characteristics.

Painted FRP molded products and cast molded products using radical-curing resins are preferably molded at room temperature or a temperature close to room temperature. Examples of molding methods for painted FRP include hand lay-up molding, spray-up molding, cold press molding, and resin injection molding.

Next, examples will be shown below to help understand the present invention. In addition, parts in the examples mean parts by weight unless otherwise specified.

Example 1 A silicone rubber mold with inner dimensions of 400 mm x 400 mm x 10 mm was filled with unsaturated polyester resin (Showa Kobunshi).
A mixture consisting of 100 parts of Rigoratsuk #2004W), 300 parts of washed and dried fly ash, 2 parts of methyl ethyl ketone peroxide, 1 part of cobalt naphthenate, and 5 parts of black pigment was injected to a thickness of 9 mm and the gel was formed. turned into

Then the same unsaturated polyester resin as above
Further, a transparent resin consisting of 100 parts of glass beads of 0.1 to 0.3 microns, 2 parts of methyl ethyl ketone peroxide, and 1 part of cobalt naphthenate was poured into the mold until it was full.

When the surface of the resin becomes sticky and uncured,
On a foamed polystyrene sheet with a thickness of about 0.8 mm and a foaming ratio of about 30 times, 100 parts of a photocurable resin (Lipoxy SP-1509, manufactured by Showa Kobunshi Co., Ltd.) and a coloring agent (made by Nippon Metal Powder Co., Ltd.) were added. A picture of a sea bream was drawn with a printing ink mixed with 5 parts of No. 5-500G (for gold ink), and the ink was fixed by exposing it to sunlight for 2 hours. in close contact with the
A foamed polystyrene sheet was dissolved in a radical curing resin, and a pattern was transferred to the resin surface. The sheet dissolved in the resin in about 5 minutes.

After curing, a polyurethane resin clear lacquer (Kansai Paint) is applied as a top coat on this pattern surface.
Acrylic #2026GL Clear (curing type using a predetermined amount of isocyanate curing agent) manufactured by Co., Ltd.)
I applied a layer of spray paint to a thickness of about 200μ. After hardening, the product was polished and buffed to create a beautiful cast product with a striking depth of gold on a black background with a gold pattern similar to that of a sea bream maki-e.

Example 2 A wax-based mold release agent was applied onto a glass plate measuring 300 mm x 300 mm x 5 mm. Next, a #380 glass mat was placed on top of the mat and impregnated with a photocurable unsaturated spiroacetal acrylate resin (Spirac U-3163, manufactured by Showa Kobunshi Co., Ltd., containing a photoinitiator), and an output of 30kW was applied. Using an ultraviolet irradiation device with
The gel was allowed to fall by passing 20 cm under the lamp at a speed of 10 m/min.

After laminating the second layer in the same manner as above, the third layer was further laminated thereon.

When the resin impregnated into the third layer of glass pine is in a liquid state, a printed film with a morning glory flower pattern screen-printed using a drying oil fatty acid modified alkyd resin ink is attached to a 50μ thick polycarbonate film. When the polycarbonate film was allowed to stand for about 1 hour, the polycarbonate film was dissolved in the photocurable unsaturated spiroacetal acrylate resin and the pattern was transferred to the resin surface.

After curing, the same resin as above was applied as a top coat to a thickness of approximately 0.2 mm on the pattern surface, and the same resin was passed through the same ultraviolet irradiation device as above three times at a speed of 2 m/min to cure. completed.

Then, after turning it over, the glass surface was also irradiated with ultraviolet rays under the same conditions as above to be photocured.

When the glass plate was removed from the mold, a beautiful decorative plate with a flower pattern emerging from the milky-white translucent FRP layer was obtained.

Claims (1)

[Claims] 1. When curing a radical curing resin or a radical curing resin and a fibrous reinforcing material, printing ink is used on a film or foam sheet soluble in the resin at an uncured stage when the resin is liquid or sticky. A film or foam sheet printed with an arbitrary pattern is brought into close contact with the resin surface so that the pattern side is in contact with the resin surface, the film or foam sheet is dissolved in the resin, the pattern is transferred to the resin surface, the resin is cured, and then the transfer is performed. A method for producing painted molded products, which is characterized by painting the patterned surface with transparent or semi-transparent paint.