JPH0326544A - Decorative composite material and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve external surface quality, especially, a depth or thickness feeling by providing the first layer composed of a thin plate made of natural precious wood impregnated with a thermosetting resin strongly bondable to a base material, the second layer composed of a fiber sheet material impregnated with a thermosetting resin and a layer of a thermosetting resin showing crosslinking reaction or adhesiveness. CONSTITUTION:A laminate is prepared by laminating decorative veneer 12 composed of natural precious wood impregnated with a thermosetting resin strongly bondable to a base material 11 and a fiber sheet material 13B impregnated with a resin showing crosslinking reaction to the resin of the decorative veneer 12. By applying primary thermal pressure to the laminate in a press mold whose inner surface is subjected to mirror surface finish, the preform consisting of the base material 11, the decorative veneer 12 and the fiber sheet material 13B is formed. Subsequently, the preform is coated with a thermosetting resin solution 13A such as a solution of a thermosetting polyurethane resin capable of being subjected to the crosslinking reaction with the thermosetting resin of the fiber sheet material 13B of the preform or strongly bondable to said thermosetting resin immediately before perfect curing. Further, by applying secondary thermal pressure to the coated molded body, the base material 11, the resin impregnated decorative veneer 12, the resin impregnated sheet material layer 13B and the surface coated transparent resin layer 13A are integrally and perfectly cured and molded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a decorative laminate composite having a transparent resin surface coating layer used for, for example, automobile interior parts such as center clusters, console upper panels, door trim ornament panels, etc. Concerning materials and their manufacturing methods, they include decorative laminate composite materials with a transparent resin surface coating layer that allows the natural wood grain to be visible, especially those used in high-end vehicles. [Prior Art] As shown in Figure 2, a high-grade decorative composite material with a surface coating layer of transparent resin on a decorative natural wood veneer for automobile interiors is made of plywood such as beech, shina, birch, or lauan as a base material. 4, and on top of this, a decorative veneer 2 made by slicing beautiful natural wood such as teak, bird's eye mable, walnut, and scrap into a thickness of about 0.2 to 1.5 ml1 is layered, and this laminate is coated with phenolic resin and area. After bonding and integrating by heat pressing using a resin adhesive or resin-impregnated viewing film 5, the inner and outer peripheries are trimmed and then finished by painting with a spray gun 7 for a transparent resin coating film 6. It is made by doing. With the recent improvement in the general economic level, natural materials have been reconsidered, and in the automobile market, 6 natural wood decorative veneers are coated with transparent resin to create a high-gloss, mirror-like surface. Products that are smooth and have a sense of depth are being put into practical use mainly for internal parts of luxury cars. However, the transparent resin coating requires several preparations, including sanding to smooth the decorative veneer and remove dirt, and multiple coats of polyester or urethane-based colored paint to prevent discoloration and tar, and to even out the exterior color tone. After applying a second undercoat, drying, and re-sanding, as a finishing process, an intermediate coat of polyester or urethane-based transparent paint is applied to give a sense of texture, depth, and transparency, and to prevent eye discoloration. After applying a top coat and drying, it is necessary to finish by sanding and polishing with compound wax. In addition, these coatings are generally applied using an air spray coating method using a spray gun 7, but the coating efficiency of the coating is low. The loss is large, and it is difficult to finish a smooth and uniform paint film, causing boils to form on the painted surface.
It is prone to surface defects such as sagging, color unevenness, whitening, and orange beer. For this reason, the work was finished with careful consideration by skilled painting technicians, and with sufficient time and strict work management. Furthermore, decorative laminate composite materials used as interior materials for automobiles are strongly exposed to external effects such as temperature, humidity, and sunlight, so the base material made of natural wood plywood is prone to expansion and contraction. Due to the effects of microbubbles and moisture contained in the decorative veneer being viewed, as well as differences in wood grain density, the transparent resin coating will expand and contract, creating minute irregularities on the painted surface, which not only impairs smoothness and gloss. , which may cause cracks, peeling, warping, and deformation in the long term.

As mentioned above, when manufacturing decorative laminate composite materials using conventional techniques, highly skilled techniques, numerous steps, and accompanying painting equipment are required, especially in the painting process of the transparent resin coating layer 6 using the spray gun 7. Moreover, since the work takes time, production efficiency is low, which has a large impact on manufacturing costs, and the product also lacks long-term durable quality.
Improvement was strongly desired. Furthermore, since the decorative veneer is made of natural wood and the base material is plywood, air and moisture (adhesive ), which tend to collect, and this is caused by cloudy spots and boiling that occur within the paint film or at the interface between the paint film and the decorative veneer when the paint film dries, as well as minute irregularities and bumps that occur under usage environmental conditions with significant changes in temperature and humidity. Since it can cause problems such as cracks and peeling, countermeasures have been a problem. Decorative veneers include teak, rosewood (board grain and straight grain),
Thin boards such as bird's eye mable (heathered) and walnut (board grain, straight grain, and distorted) are used by adhering to the base plywood such as beech, shina, birch, etc., but their tensile strength is low and they do not elongate. It has the disadvantage that it can only be molded into flat or simple curved shapes compared to general furniture because it has a small amount of cracking and is easily broken during molding.

In addition, in the painting process, it is necessary to eliminate paint defects such as uneven color, orange beer 5 drip, sanding, fading, etc., and to prevent paint loss during spray painting, equipment and environmental pollution caused by paint spray dust and organic solvent volatilization. Prevention was also an issue. Therefore, in order to solve the problems in the conventional technology as described above, the present inventors have developed several techniques for manufacturing decorative laminate composite materials using a mold press, which can omit the finishing coating process, and have filed a patent application. (Japanese Patent Application Nos. 1-75974, 1-75975 and 1-95987). [Problems to be Solved by the Invention] The present invention aims to further improve the design quality of the appearance, since there is still room for improvement in the composite material of the previous invention, especially in terms of depth and thickness. It is an object of the present invention to provide a decorative laminate composite material of the type mentioned at the beginning, which comprises a base material such as this, a decorative veneer covered thereon, and a transparent resin surface coating layer, and a method for manufacturing the same. [Means for Solving the Problems] The present inventors have continued various studies in order to solve the above problems, and as a result, in the decorative board composite material produced by die pressing as described above, the transparent F ? When the A-fat surface coating layer is composed of a lamination of multiple different layers, and among them each has a refractive index clearly different from each other, the appearance surface quality of the resulting composite material, especially the depth and It was discovered that the thickness feeling was significantly improved, and the present invention was developed. That is, in the decorative veneer composite material of the present invention, the decorative veneer is made of a thin natural board impregnated with a thermosetting resin that can strongly adhere to the base material, and the transparent resin surface coating layer is formed in the mold. A first layer formed by leaching of the impregnated resin inside the decorative veneer during heat pressing, and a thermosetting resin that can cross-link with the impregnated resin of the decorative veneer on the fiber sheet material covered thereon. a second rvi formed by hot press curing of a coating sheet impregnated with RVI, and a thermosetting resin that can cross-react with the resin of the second layer, or at least strongly adheres thereto, and further coats the second rvi. The third layer is formed by heat press hardening. In an advantageous embodiment of the decorative laminate composite according to the invention, the base material is a low-shrinkage sheet made of a reinforcing material of inorganic or organic fibers impregnated with a resin liquid containing a thermosetting resin and a low-shrinkage agent. The decorative veneer consists of a thin sheet of natural fiber impregnated with a thermosetting resin capable of crosslinking with the base resin. In this case, not only simple shaped composite materials but also
Composites with various three-dimensional structures can also be obtained by hot pressing in molds of corresponding shapes, and composites with high strength can be obtained.

In yet another advantageous embodiment of the decorative laminate composite according to the invention, the first layer of the transparent resin surface coating layer is
, the second and third layers have different optical refractive indexes from each other, and preferably the refractive indexes gradually decrease in the order of the first layer>second layer>third layer, so that this The exterior has an excellent sense of depth and thickness, and is extremely rich in design. The method for producing a decorative laminate composite material according to the present invention includes, on a base material as described above, a decorative veneer made of a thin board of natural precious wood impregnated with a thermosetting resin capable of strongly adhering to the base material; Further, a fiber sheet material impregnated with a thermosetting resin capable of crosslinking with the impregnated resin of the decorative veneer is placed thereon to form a laminate, and this laminate is subjected to primary heat pressing in a press mold. to form a preformed body of a base material, a decorative veneer, and a fiber sheet material, and then, immediately before this preformed body is completely cured, can a crosslinking reaction be performed with the resin of the fiber sheet material;
Alternatively, the surface of the preform is coated with a thermosetting resin liquid that strongly adheres to the preform, and the coated mold is further heat-pressed for a second time, thereby forming a base material, a resin-impregnated decorative veneer, and a transparent resin surface coating layer are integrally molded under complete curing. In one of the advantageous embodiments of the method for manufacturing the decorative veneer composite material, a fibrous reinforcing sheet is applied to the back side of the decorative veneer in advance. This prevents the decorative veneer from cracking during molding, resulting in a good product.

In yet another advantageous embodiment of the method for manufacturing the decorative veneer composite material, the inside of the mold is depressurized and degassed prior to mold clamping and pressurization during the primary heat pressing, which removes air present in the decorative veneer, etc. The pores and recesses are filled with resin, which is effective in preventing surface defects such as cloudy spots and boiling on the product, as well as minute irregularities, cracks, and peeling that occur under environmental conditions with significant changes in temperature and humidity. ．． In yet another advantageous embodiment of the method for producing a decorative laminate composite, the resin coating of the preform after the primary heat pressing is performed by:
This is done by slightly lifting the upper mold and injecting the resin liquid, but this eliminates the need to depressurize the mold again and shortens the process time. [Function] If the method for manufacturing a decorative laminate composite material according to the present invention is to explain the procedure using figures, as shown in Figure 1, the process involves forming a base material II as described above, and a method that is at least strongly adhered to this base material. Decorative veneer l2 of natural precious wood impregnated with thermosetting resin to obtain,
The resin of this decorative veneer and #a fiber sheet material 13B impregnated with a resin capable of crosslinking reaction are sequentially stacked to form a laminate, and this laminate is placed in a press mold with a mirrored inner surface. First, a preformed body of the base material 11, the decorative veneer l2, and the fiber sheet material 138 is formed by primary heat pressing, and then, just before this preformed body is completely cured, this preformed body is pressed into the above fiber sheet material. 13B is coated with a thermosetting resin liquid such as a thermosetting polyurethane resin that can crosslink or at least strongly adhere to the thermosetting resin, and then this coated molded body is further coated with 3A. Secondary heat pressing, thereby substrate II. FM
Grease-impregnated decorative veneer l2, resin-impregnated sheet material layer 13B, and surface coating transparent resin layer! Completely harden and mold 3A in one piece. The above thermosetting resin layer +3A may be coated by the pouring method after once opening the mold, but the upper mold corresponding to the mold cavity is slightly raised and the resin liquid is poured into the mold. It can also be done by injection. The decorative laminate composite material according to the present invention has a transparent resin surface coating layer consisting of a base material, a resin-impregnated decorative veneer, a resin-impregnated sheet material, and a leg W1FM fat layer, which are integrally cured and molded, so that the entire surface is strongly strengthened. It has a high strength that is not found in conventional products due to its combination, and in particular, its transparent resin coating layer is formed by heat press curing of the first layer 13C leached from the decorative veneer during heat pressing and resin-impregnated sheet material. It consists of the second layer 13B and the third layer +3A made of a hardened layer of coating resin, and has different light refraction, transmission and reflection properties, so its appearance is extremely rich in design. Furthermore, the heat-press cured layer of resin liquid coated by the above method provides high gloss and excellent durability and strength even without surface polishing. The base material II of the above-mentioned decorative laminate composite material is not particularly limited as long as it can be strongly bonded to the resin-impregnated decorative veneer l2 to be placed over it and can be cured integrally by heat pressing, but in particular thermosetting resins can be used. It is preferable to use a sheet-like compound made of fiber-reinforced plastic impregnated with a reinforcing material made of inorganic or organic fibers with a resin liquid containing a low-shrinkage agent. Using this method, it becomes possible to obtain a decorative laminate composite material with a corresponding three-dimensional shape. When a preform of a low-shrinkage sheet-like molding compound is used as a base material, high mold-embedding stability and strength can be obtained even with relatively thin walls, and the resulting product also has high dimensional stability. The reinforcing fiber materials used for such base materials include organic and non-silicon high-strength fibers, and among them, relatively short glass fiber rovings are preferred. As the thermosetting resin for this base material, one or more of unsaturated polyester, epoxy resin, diallyl phthalate resin, or alkyd resin is used. In addition to these thermosetting resin brevolimers, thermoplastic resins as low-shrinkage agents (polyethylene, polyester, styrene-butadiene copolymers, polymethyl methacrylate, etc.) as well as other customary materials, such as fillers, crosslinkers, A mixture of thickeners, mold release agents, catalysts, colorants, polymerization stabilizers, solvents, etc. is impregnated into the reinforcing fiber material described above, and aged to a tag-free state over time. The resulting low-shrinkage sheet molding compound (
It is preferable to use a molded product of SMC (hereinafter abbreviated as SMC). The decorative laminate composite material obtained by this method has high rigidity,
It has high strength, thin wall, high heat resistance, high water resistance, and moderate flexibility.It has high dimensional stability and has reinforcing ribs or embedded bosses for screw fittings for attaching parts and retainer drive fittings. Now you can insert it into this,
In addition, not only planar decorative materials but also non-planar decorative materials can be made using the hot press molding method according to the present invention, which improves the degree of freedom in design and significantly reduces parts installation costs. Decorative veneer 12 can be applied directly to the grain or straight-grained or heathered thin boards of natural precious woods such as teak, rosewood, walnut, scraps, and bird's eye maable, or after being colored by dyeing or painting, it can be strongly bonded to the base material. A thermosetting resin capable of adhesion, especially a resin capable of crosslinking with the thermosetting resin when SMC as described above is used 5 Preferably also one of a diallyl phthalate resin, an unsaturated polyester resin, and an alkyd resin A material impregnated with three or more brevolimers is used. During heat pressing, the thermosetting resin Brepolymer impregnated into the decorative veneer causes a crosslinking reaction with the surface coating resin and the base material resin to form a strong bond. In other words, it softens and exhibits flexibility at the early stage of the reaction, making it extremely effective in preventing cracking during molding. In addition, air and adsorbed moisture in the cracks on the back of decorative veneers and minute gaps such as wood fiber conduits are removed when a vacuum degassing process is applied after the mold is closed. In this resin impregnation process, it is pre-dried and filled with resin liquid, so even in a usage environment where temperature and humidity changes repeatedly, the difference in expansion and contraction of the transparent resin layer and decorative veneer will cause the surface of the transparent resin surface coating layer to change. The occurrence of minute irregularities (eye discoloration), whitening, peeling, cracks, etc., is prevented.

In addition, if you use a fibrous sheet such as washi paper or other synthetic fiber non-woven fabric as a reinforcing backing material and line it with a heat-resistant SBR adhesive beforehand, the decorative veneer will not crack during molding. This can be prevented and a good product can be obtained. As this fibrous sheet, it is preferable to use pulp paper, which has strong toughness and stable physical and chemical properties, or a nonwoven fabric made of synthetic fibers such as polyester fiber, acrylic fiber, nylon fiber, or polyvinyl alcohol fiber. ．． Resin-impregnated sheet material 13B to be placed over the decorative veneer I2
After hot press molding, a fiber sheet made by Fabric Co., Ltd. that can cross-link with the thermosetting resin in the decorative veneer to an extent that does not impair the clear visibility of the wood grain of the underlying decorative veneer, preferably a similar material. Impregnated with diallyl phthalate resin, unsaturated polyester resin, or alkyd resin brepolymer is used. Preferably 20 −
Washi paper or various synthetic fiber non-woven fabric with a weight of 40g/c is impregnated with the above resin and has a thickness of 0.3-0.
．． A 5m+w sheet is used. Finally, the resin for the layer 13A used to cover the resin-impregnated sheet material 13B is a thermosetting resin that can strongly adhere to the resin-impregnated sheet material 9138 during heat press curing. and therefore of course this sheet material 13
The same resin as B may be used, but thermosetting polyurethane resin can be used, and in this case, a particularly excellent appearance can be obtained due to the difference in the refractive index of light. In order to form this layer 13A, the Brevolimer resins described above are used alone or as a mixture together with a crosslinking agent, a polymerization catalyst, internal mold release, a polymerization stabilizer, etc., and if necessary, modified. A resin liquid is used that is mixed with other resins for quality, fillers, etc. As mentioned above, the laminate of the base material, decorative veneer, and resin-impregnated sheet material is first heat-pressed in a mold, and the mold is opened just before each resin in this laminate is completely cured. After pouring the resin liquid onto the surface of the preform to cover it, the mold is closed again and a secondary heat press is performed. Alternatively, after the primary hot pressing, the L-shape is slightly raised without opening the mold, and the resin liquid is injected into the mold to cover the preform. The whole may be completely cured by secondary pressing.

By this heat pressing, a part of the thermosetting resin impregnated inside the decorative veneer l2 becomes the resin-impregnated fiber sheet layer 13
The lth layer 1 of the transparent coating resin layer leaches out to the interface with B.
Form 3c. Since this first layer 3c, the second layer 13B made of the cured layer of the resin-impregnated fiber sheet, and the third layer N made of the surface coating layer 13A have different refractive indexes, the decorative board composite according to the present invention has a sense of depth and thickness. It has a beautiful appearance with an excellent feel. [Example] Examples of the present invention are listed below. The base material is an unsaturated polyester SMC (Estermat AU-120 manufactured by Mitsui Toatsu Chemical Co., Ltd.) using a resin in which 5 parts of a thermoplastic polymer low-shrinkage agent is mixed with the thermoplastic resin. was used.

As the decorative veneer, we used a 0.3 inch thick Bird's Eye Mable veneer with a weight of 36 g/n on the back side.
Japanese paper with styrene/butadiene rubber adhesive (
The adhesive was strengthened with Mitsui Toatsu Chemical Co., Ltd.'s Structbond 1123). This decorative veneer was coated with unsaturated polyester resin (Orestar RP-1 from Mitsui Toatsu Chemical Co., Ltd.) using a vacuum/pressure method.
0331 100 parts by weight, 0.7 parts by weight of catalyst (D terh-barbenzoate) and 0.2 parts by weight of polymerization stabilizer methylhydroquinone.
A decorative veneer impregnated with resin was used. The resin-impregnated sheet material to cover this decorative veneer is thermosetting diallylphthalate Brevolimer (Osaka Soda,
Acrylic & 1 #i nonwoven fabric (product of Nippon Vilene Co., Ltd.) with a weight of 25 g/cm was impregnated with Dap A) to a resin amount of 140 g/1. After stacking them to make a laminate, charging the flat plate mold and closing the mold, the inside of the mold is vacuum degassed, and then the mold temperature is 140℃.
℃ and a press pressure of 100 kgf/c to obtain a preformed body. Next, before the preform is completely cured, the mold is opened and the number average molecular weight is 400 and the OH value is 340.
60 parts by weight of polyester polyol (K-Flex 188, manufactured by King, USA), and 40 parts of hexamethylene diisocyanate (TPA 100, manufactured by Asahi Kasei Corporation) with an NGO content of 23.1% (solid content).
After coating by pouring a urethane resin solution prepared by mixing parts by weight, the mold was closed again and secondary heat pressing was performed under the same conditions to completely cure the resin.

The decorative board composite material obtained in this way has an excellent sense of exploration,
It has a sense of thickness and the wood grain of the decorative veneer is clearly highlighted, giving it an extremely excellent appearance. As a result of examining the surface layer, it was found that there was a layer of unsaturated polyester resin leached from the decorative veneer under the resin-impregnated sheet material layer; It was found that it consisted of a layer of diallyl phthalate a resin with a refractive index of 1.50 and a polyurethane resin layer with a refractive index of about 1.46, and it was found that this was what provided the above-mentioned excellent external design. ．． [Effects of the Invention] The decorative laminate composite material according to claim 1 of the present invention has high strength because the entire laminate consisting of the base material, decorative veneer, resin-impregnated sheet material, and coating resin is firmly bonded together. At the same time, it provides a finished surface that has a sense of depth and thickness, has excellent design, and is highly durable and luxurious. When a sheet-like compound impregnated with a thermosetting resin containing a low shrinkage material is used as a base material according to claim 2, 3.
It allows the formation of composite materials with dimensional shapes, and has added value due to its high functional characteristics such as high rigidity, high strength, good formability, high dimensional stability, and heat and water resistance. can be further enhanced.

[Brief explanation of drawings]

FIG. 1 is a sectional view illustrating the manufacturing procedure of the decorative laminate composite material of the present invention, and FIG. 2 is a sectional view illustrating the manufacturing procedure of the decorative laminate composite material according to the prior art. II, ... Base material ■2, ... Decorative veneer +3A ... Thermosetting resin coating layer 13B ... LA fiber sheet material

Claims (8)

[Claims] (1) In a decorative veneer composite material that is integrally cured and molded by heat press, consisting of a base material, a decorative veneer placed over the base material, and a transparent resin surface coating layer closely formed thereon, The decorative veneer is made of a thin plate of natural wood impregnated with a thermosetting resin that can strongly adhere to the base material, and the transparent resin surface coating layer is applied to the interior of the decorative veneer during heat pressing in a mold. The first formed by leaching the impregnated resin
a second layer formed by heat press curing of a covering sheet covered thereon, the fiber sheet material being impregnated with a thermosetting resin capable of crosslinking with the impregnated resin of the decorative veneer;
and a third layer formed by heat press curing of a thermosetting resin that can crosslink with or at least strongly adheres to the resin of the second layer, which is coated thereon. , veneer composite. (2) The base material is a hot press molded sheet-like compound made of fiber-reinforced plastic impregnated with a reinforcing material made of inorganic or organic fibers with a resin liquid containing a thermosetting resin and a low-shrinkage agent, The decorative veneer composite material according to claim 1, wherein the impregnated resin of the decorative veneer is a thermosetting resin capable of crosslinking with the thermosetting resin of the base material. (3) The decorative laminate composite material according to claim 1, wherein the first, second, and third coating layers of the transparent resin surface coating layer have different optical refractive indexes. (4) Manufacture the decorative laminate composite material according to claim 1, comprising a base material, a decorative veneer bonded to the base material, and a transparent resin surface coating layer closely formed thereon. In order to do this, a decorative veneer made of a thin board of natural precious wood impregnated with a thermosetting resin that strongly adheres to the base material or can crosslink with the impregnated resin of the base material is placed on top of the base material. Further, a fiber sheet material impregnated with a thermosetting resin capable of cross-linking with the impregnated resin of the decorative veneer is placed on top of this to form a laminate, and this laminate is subjected to primary heat pressing in a press mold. Preferably, a preform of the substrate, the decorative veneer, and the fiber sheet material is formed, and then, just before the preform is completely cured, it is possible to crosslink or at least react with the resin of the fiber sheet material. The surface of the preformed body is coated with a thermosetting resin liquid that strongly adheres to the substrate, and then this coated molded body is further heat-pressed for a second time, thereby forming the base material, the resin-impregnated decorative veneer, and the transparent resin. A method for manufacturing a decorative laminate composite material, which comprises integrally molding a surface coating layer while completely curing it. (5) The manufacturing method according to claim 4, wherein a fibrous reinforcing sheet is bonded in advance to the back surface of the decorative veneer. (6) The manufacturing method according to claim 4, wherein the inside of the mold is depressurized and degassed prior to mold clamping pressurization in the primary hot press. (7) The manufacturing method according to claim 4, wherein the resin coating of the preformed body after the primary hot pressing is carried out by pouring a resin liquid while the mold is opened. (8) The manufacturing method according to claim 4, wherein the resin coating of the preformed body after the primary hot pressing is performed by slightly raising the upper die and injecting the resin liquid.