JP2881026B2 - Method for producing sheet for molding fiber-reinforced resin - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a sheet for molding a fiber-reinforced resin, and more particularly, to a fiber-reinforced resin sheet made of a thermosetting resin reinforced with glass fiber, carbon fiber, or the like. The present invention relates to a method for producing a sheet for molding a fiber-reinforced resin, which is a raw material when producing a resin product by a sheet molding method such as a vacuum molding method.

[Conventional technology]

Manufacturing methods of fiber reinforced resin products include hand lay-up method, spray molding method, mold molding method, vacuum molding method, pressure molding method, etc. A sheet forming method such as a vacuum forming method and a pressure forming method using a press is being developed as a method that can produce a highly accurate molded product relatively easily and efficiently.

FIG. 6 shows an outline of a conventional vacuum forming method, in which a fiber-reinforced resin formed by adding a reinforcing fiber such as a glass fiber or a carbon fiber to a liquid thermosetting resin such as a polyester resin to form a sheet. The molding sheet S is placed on a female mold (or male mold) m, and vacuum suction is performed from a vacuum suction V provided on the mold surface of the mold m. After shaping the molding sheet S so as to follow the mold surface, the molded sheet S is heated and cured by heat transfer from the mold surface of the molding die m, so that a fiber-reinforced resin molded product having a desired shape is obtained. Is to be done.

In the above method, the covering film C made of a flexible and stretchable thermoplastic resin is attached to the surface of the molding sheet S that does not contact the mold surface. When the coating film C is shaped by vacuum suction, air bubbles may enter the resin material of the molding sheet S due to a pressure difference between both surfaces of the molding sheet S, glass fibers may be fuzzy, or the surface may have irregularities. It is used to prevent

In addition, if the fiber-reinforced resin layer containing glass fibers or the like is exposed on the surface of the molded product, the smoothness of the surface is impaired by unevenness of the glass fibers or the like, or the texture of the surface is not good. Of the molding sheet S, a surface resin layer made of a thermosetting resin containing no reinforcing fibers and an appropriate coloring agent or the like added thereto may be laminated on the surface of the molding sheet S that is in contact with the mold surface. Is being done.

[Problems to be solved by the invention]

However, in the conventional molding method as described above, in the heat curing step, the coating film C covering the surface of the molding sheet S is locally melted, and as a result, the coating film C is peeled off, and the above-described molding method is performed. There is a problem that it is impossible to prevent air bubbles from penetrating into the use sheet S, smoothen the surface, and the like, and deteriorate the finished product.

The reason that the coating film C is locally melted is that when the thermosetting resin constituting the molding sheet S is heated and cured, heat is generated, and the surface layer adjacent to the coating film C starts to be cured first and has a fluidity. Heat is locally trapped in the area where the heat loss does not occur, and the coating film C in that part becomes high heat and melts, and the coating film C stretched at the time of shaping peels off to return to its original state. It will be. If the surface of the thermosetting resin is in a liquid or softened state at the time when the coating film C is peeled, the thermosetting resin is peeled off with respect to the coating film C, or as described above.
Flushing of glass fibers, intrusion of air bubbles, surface irregularities, and the like occur.

In order to solve such a problem, the present inventors cured only the thermosetting resin in the surface layer portion adjacent to the coating film C in the molding sheet S by ultraviolet irradiation separately from the entire heat curing. We invented a method to make this possible and filed a patent application in Japanese Patent Application No. 2-26903.

FIG. 7 shows an outline of the above method, in which the molding sheet S is a fiber-reinforced transparent resin layer a in which a glass fiber f is impregnated with a transparent thermosetting resin mixed with an ultraviolet curing agent,
A surface resin layer b made of only a colored thermosetting resin without the glass fiber f is laminated, and ultraviolet rays are applied from above the coating film C to the molding sheet S formed along the mold m. Irradiation cures the entire surface layer portion of the fiber-reinforced transparent resin layer a (the portion indicated by the mark x in the figure). Then, it is possible to prevent the heat generated when the entire molding sheet S is heated and hardened from being held high only in a part of the surface layer portion. Further, even if the coating film C is locally melted, if the surface layer portion of the fiber-reinforced transparent resin layer a is hardened, fluffing of glass fibers, intrusion of bubbles, and the like do not occur.

In this method, the fiber-reinforced transparent resin layer a must be transparent in order to absorb and cure ultraviolet rays, and in order to produce a colored molded product, the fiber-reinforced transparent resin layer a is colored. The surface resin layer b needs to be laminated.

However, in the above prior art, the surface resin layer b is locally thinned depending on the shape of the fiber-reinforced resin molded product,
The inner fiber-reinforced transparent resin layer a is visible, and the color tone of the surface is not uniformly finished, causing color unevenness and poor appearance.

This is because, as shown in FIG. 7, when there is a protrusion P on the surface of the mold, the surface resin layer b is
This is because the thickness is reduced by being strongly pressed or stretched locally. Since the surface resin layer b does not contain reinforcing fibers, it is more easily deformed than the fiber-reinforced transparent resin layer a, and distortion during molding is concentrated on the surface resin layer b, so that the surface resin layer b is inevitably thin. If the fiber-reinforced transparent resin layer a is colored in the same color as the surface resin layer b, the appearance is not conspicuous even if the surface resin layer b is thinned, but if the fiber-reinforced transparent resin layer a is colored. UV light does not pass through, and the surface layer cannot be cured by the above-described UV irradiation.

In order to solve such a problem, a three-layer fiber reinforced resin having a fiber reinforced colored resin layer colored in the same color as the surface resin layer between the fiber reinforced transparent resin layer a and the surface resin layer b Forming sheets are effective. In order for the three-layer molding sheet to effectively work to solve the above-mentioned problems, it is essential that the fiber-reinforced transparent resin layer a be ultraviolet-curable. Therefore, in order to prevent the function of each layer from being hindered by mixing the layers with each other, the production of the three-layer fiber-reinforced resin molding sheet is performed after the previously formed layer. This is carried out by performing a thickening treatment prior to the formation of the layer. That is, usually, after forming the surface resin layer b on the coating film, a thickening treatment is performed, and then, after forming a fiber-reinforced colored resin layer thereon, a thickening treatment is performed again. In order to manufacture by the procedure of forming the fiber reinforced transparent resin layer a thereon, at least two thickening treatments are required until the entire sheet is formed. This means that the thickening treatment usually requires 3 to 5 hours, and therefore, the production of the three-layer fiber-reinforced resin molding sheet is extremely poor in productivity. Therefore, in spite of the excellent performance of the sheet, it is currently an obstacle to its practical use.

Therefore, an object of the present invention is to provide a method for efficiently producing a sheet for molding a fiber-reinforced resin comprising the above three layers.

[Means for solving the problem]

A method for producing a sheet for forming a fiber-reinforced resin according to the present invention, which solves the above-mentioned problems, is a sheet for forming a fiber-reinforced resin, which is formed by shaping along a mold surface of a forming die and then heat-cured to form the sheet. A colored surface resin layer arranged on one surface of the sheet, a fiber-reinforced colored resin layer arranged adjacent to the inside of the surface resin layer and colored in a similar color to the surface resin layer, and the other of the molding sheet At least a UV-curable fiber-reinforced transparent resin layer disposed on the surface.

In a method for producing a sheet for molding a fiber-reinforced resin,
After forming the fiber-reinforced transparent resin layer, a fiber-reinforced colored resin layer is laminated on the fiber-reinforced transparent resin layer without subjecting the fiber-reinforced transparent resin layer to a thickening treatment. , And then a surface resin layer is laminated.

Various thermosetting resins can be freely used as the resin material constituting the fiber-reinforced resin molding sheet, similarly to the ordinary molding sheet. Specific examples include unsaturated polyester resins, epoxy resins, unsaturated polyurethane resins, epoxy (meth) acrylate resins, and the like. Resin materials include heat curing agents, ultraviolet curing agents and curing aids,
Various additives are blended as required. For example, when the resin material is an unsaturated polyester resin, specific examples of the heat curing agent include organic peroxides and diazo compounds.

As the reinforcing fibers for the resin material, the same fibers as in the case of ordinary fiber reinforced resins can be used, and specifically, glass, carbon, metal, Kevlar (trade name, aramid resin),
Roving, mat, swirl mat, non-woven fabric and the like of fibers made of Tetron (trade name, polyester resin) and the like are included. A basic fiber-reinforced resin layer is formed by applying or impregnating the above-mentioned reinforced fibers with the liquid resin material to form a sheet. As for the content of the reinforcing fiber contained in the fiber-reinforced resin layer, the reinforcing effect generally increases as the fiber content increases, but molding becomes difficult. Usually, a fiber having a fiber content of about 10 to 70% by weight is used.

The surface resin layer is given a predetermined color by adding various colorants to the resin material as described above, and may also be added with various additives for adjusting the surface properties and texture. . The colorant used for the surface resin layer is not particularly limited as long as it does not inhibit the curability of the resin layer,
Various pigments, dyes and the like can be used. For example, titanium white (titanium oxide) can be mentioned as a typical white colorant.

In the present invention, as the fiber-reinforced resin layer, a fiber-reinforced transparent resin layer in which the reinforcing fiber is impregnated with a resin material having ultraviolet curability by blending a transparent resin material with an ultraviolet curing agent or the like; The layer is combined with a fiber-reinforced colored resin layer colored in a similar color.

The fiber-reinforced transparent resin layer contains an ultraviolet curing agent in addition to a normal heat curing agent. Specific examples of the ultraviolet curing agent include, for example, the following as an ultraviolet curing agent for an epoxy resin. Can be

Aryldiazonium salts ArN = NPF ₆ (Ar≡ allyl or substituted allyl group) diaryliodonium salts ^{_{Ar 2 I + X - (Ar}} = aryl group or a substituted allyl group X ^- = BF ₄ ^-, As
^{_{F 6 -, PF 6 -,}} SbC1 6 - , etc.) triarylsulfonium salts ^{_{Ar 3 S + X - (Ar}} = aryl group or a substituted allyl group X ^- = BF ₄ ^-, As
^{_{F 6 -, PF 6 -,}} SbC1 6 - , etc.) fiber-reinforced colored resin layer is not limited to colored in exactly the same color as the surface resin layer, when producing a fiber-reinforced resin molded article, the surface resin layer However, even if the color is locally thinned and the fiber-reinforced colored resin layer on the back surface is visible, the same color or the same color may be applied as long as the color difference from the surrounding portion is not conspicuous.

The sheet for forming a fiber-reinforced resin has the surface resin layer disposed on one surface, the fiber-reinforced colored resin layer disposed adjacent to the surface resin layer, and the fiber-reinforced transparent resin layer disposed on the other surface. Are arranged, and a plurality of resin layers are laminated. Between the fiber reinforced colored resin layer and the fiber reinforced transparent resin layer, another fiber reinforced resin layer made of the same resin material or reinforced fiber may be laminated.
That is, provided that the fiber-reinforced resin layer having at least the fiber-reinforced colored resin layer and the fiber-reinforced transparent resin layer as described above, and a surface resin layer laminated on the surface thereof,
There is no problem in laminating other material layers.

When manufacturing a fiber-reinforced resin molding sheet, the above-described layers are sequentially laminated by the same means as a normal resin sheet. However, in the present invention, after forming the fiber-reinforced transparent resin layer, the fiber-reinforced colored resin layer is laminated thereon without subjecting this layer to a thickening treatment. The stacking order of each layer other than the above can be freely set. In the present invention, except for laminating the fiber-reinforced transparent resin layer and the fiber-reinforced colored resin layer according to the above procedure, in other processes when manufacturing a sheet for fiber-reinforced resin molding, if necessary, Thickening treatment can be performed during the lamination or after the lamination is completed. For the thickening treatment, a method of adding a thickening agent to the resin material in advance, light irradiation, heating, and other ordinary thickening means can be applied. The thickening treatment facilitates the work of laminating the constituent layers and the handling of the entire molding sheet. However, it is preferable to reduce the number of times of the thickening treatment as much as possible, because the production efficiency of the fiber-reinforced resin molding sheet is good.

When the fiber reinforced resin molding sheet is used for molding, a covering film is pasted on one or both surfaces of the fiber reinforced resin molding sheet. The material of the covering film, various thermoplastic resin films similar to those used in the ordinary molding method is used, particularly, so that it can be formed simultaneously with the molding sheet, with flexibility and stretchability, Use a material that is not affected by the resin material or the like included in the molding sheet. Specific examples include nylon, vinylon, and polyvinyl alcohol. The thickness of the coating film may be the same as in the case of a normal molding method, but is generally 5 to 500 μm.
m, more preferably about 10 to 100 μm. When attaching the covering film to the molding sheet, the covering film can be attached only by bringing the covering film into close contact with the surface of the resin layer made of a liquid resin material. Also,
It can also be achieved by sequentially laminating each resin layer constituting the molding sheet on the surface of the covering film.
If the covering film is pasted on the forming sheet, the storing and handling of the forming sheet containing the liquid resin material becomes easy, and even if a plurality of forming sheets are stacked, they do not stick.

The sheet for molding a fiber-reinforced resin manufactured by the method according to the present invention is formed by a normal vacuum forming method, a pressure forming method, or the like.
A fiber-reinforced resin molded article having an arbitrary shape is manufactured, and each step of the molding method, molding conditions, structure of the mold, and the like can be freely set.

For example, the mold may be either a female mold or a male mold.
Further, as a material of the molding die, usually, a die made of steel, aluminum or the like is used, but a resin die or the like can be used.

When the fiber reinforced resin molding sheet is mounted on the mold, a surface resin layer is placed on the mold side of the mold, and the fiber reinforced transparent surface is opened on the side that is open without contact with the mold surface of the mold. The resin layer is arranged.

Means for shaping the sheet for molding along the mold surface of the mold include a vacuum forming method of shaping the sheet by vacuum suction from a vacuum suction port provided in the mold, a mold surface of the sheet for molding. A pressure molding method in which a fluid pressure such as air is applied to the surface on the opposite side to the above, and the molding sheet is pressed against the mold surface to form the molding sheet, or a method in which the above-described vacuum suction and pressure application are used in combination can be adopted.

As a means for heating and curing the molding sheet, a method of heating the molding sheet by heat transfer from the mold surface, or a method in which the molding die is configured to be freely heatable by incorporating a heater in the molding die, or In addition to the above-described heating method, a method of heating the entire atmosphere, a method of irradiating infrared rays, and the like can be used in combination.

When using the fiber-reinforced resin molding sheet produced by the method according to the present invention, the fiber-reinforced transparent resin layer of the molding sheet is irradiated with ultraviolet light until the molding sheet is cured by heating, so that the fiber-reinforced transparent resin layer is irradiated. At least the surface layer portion of the resin layer is cured. The ultraviolet irradiation is performed using a normal ultraviolet lamp or the like.

The time of irradiating the ultraviolet rays may be set at an appropriate time from before the shaping of the molding sheet until the molding sheet is completely heated and cured. However, the surface layer portion should not be excessively hardened so that shaping cannot be performed at the stage of shaping the forming sheet, and before the heat curing of the forming sheet proceeds and the coating film melts, The surface layer of the molding sheet must be at least semi-cured. Further, since there is a time lag between the irradiation of the ultraviolet rays and the progress of the curing of the surface layer portion of the molding sheet, the above-mentioned conditions are also taken into consideration. The irradiation timing of ultraviolet rays and other irradiation conditions are set. Specifically, UV irradiation can be started before the shaping process,
Ultraviolet irradiation can be performed simultaneously with the shaping step, or ultraviolet irradiation can be performed after the shaping step.

Curing of the surface layer by irradiation with ultraviolet rays is preferably stopped before the surface layer is completely cured. This is because if the surface layer is completely cured by UV irradiation,
Due to the heat curing by heat transfer from the mold surface, curing occurs with shrinkage stress remaining in the center part, causing a problem that cracks easily occur inside the molded product, and the surface layer part is completely cured If not, the contraction stress can be released. In addition, even if the surface layer portion is not completely cured by ultraviolet irradiation, it is finally completely cured by heat curing of the entire molding sheet in the same manner as the other portions.

The thickness of the surface layer portion to be cured by ultraviolet irradiation does not need to cover the entire fiber-reinforced transparent resin layer.Even if the coating film is locally melted by curing heat, bubbles may enter the resin or the resin material may be removed. A small thickness is sufficient as long as the thickness is small enough to prevent the coating film from peeling off. In addition to irradiating the entire surface of the molding sheet with ultraviolet rays to cure the surface layer portion, and irradiating only the portions where the coating film is likely to melt as described above with ultraviolet rays, the surface layer portion is locally cured. May be.

[Action]

When forming a fiber reinforced resin molding sheet in which a fiber reinforced resin layer and a colored surface resin layer are laminated, even if there is a place where the surface resin layer becomes thin due to the molding shape, it is adjacent to the surface resin layer If a fiber-reinforced colored resin layer of a similar color to the surface resin layer is provided, it is not noticeable that the surface resin layer has become thinner in appearance, and the surface of the molded product exhibits a uniform colored state. Become. Since the fiber-reinforced colored resin layer contains reinforcing fibers, even if it is pressed or stretched during molding, the thickness does not become thin, and the coloring of the surface resin layer can be reliably reinforced. I can do it.

Also, if a fiber-reinforced transparent resin layer having ultraviolet curability is provided on the surface of the molding sheet opposite to the surface resin layer, at the time of molding, the fiber-reinforced transparent resin layer is irradiated with ultraviolet light, Only the surface layer portion of the molding sheet can be cured separately from the entire heat curing. as a result,
The coating film adhered to the surface of the molding sheet is prevented from being melted and peeled, and a good finish is obtained without intrusion of air bubbles, fluffing of reinforcing fibers, or unevenness of the surface.

When manufacturing a sheet for forming a fiber-reinforced resin as described above, it is only necessary to sequentially laminate the constituent layers, but when laminating a plurality of fiber-reinforced resin layers, first between the upper and lower resin layers, The phenomenon that the formed lower layer resin is mixed into the newly laminated upper layer resin is likely to occur. Therefore, when a fiber-reinforced colored resin layer is formed, and then a fiber-reinforced transparent resin layer is laminated thereon, the colorant contained in the colored resin layer moves into the transparent resin layer, and the transparent resin layer becomes transparent. Will reduce the performance. If the transparency of the fiber-reinforced transparent resin layer deteriorates, the absorbability of ultraviolet rays decreases, and the ultraviolet curing of the surface layer cannot be performed sufficiently. In addition, it becomes impossible to prevent fluffing of the reinforcing fibers or generation of irregularities on the surface.

Therefore, in this invention, after forming the fiber-reinforced transparent resin layer, the fiber-reinforced colored resin layer is laminated on the fiber-reinforced transparent resin layer. In this case, the resin is less likely to be mixed into the previously formed transparent resin layer from the colored resin layer to be laminated later, and the possibility that the colorant migrates into the transparent resin layer is reduced.

This is because the resin movement due to the impregnation and defoaming work when laminating each layer is that the excess resin in the lower layer (the layer already impregnated and defoamed) is pushed up to the upper layer that is currently laminated In order to move, the coloring of the fiber-reinforced colored resin layer laminated on the upper layer up to the lowermost layer of the fiber-reinforced transparent resin layer laminated first (that is, the contact surface between the fiber-reinforced transparent resin layer and the covering film). It is considered that the agent cannot move, and as a result, the ultraviolet curable surface layer can be sufficiently secured in the fiber-reinforced transparent resin layer.

By the action as described above, the transparency of the fiber-reinforced transparent resin layer can be sufficiently ensured, and the above-described ultraviolet curing of the surface layer portion can be reliably and sufficiently performed. Further, the higher the viscosity of the resin liquid for forming the fiber-reinforced transparent resin layer, the higher the above-mentioned effects and effects, which are preferable. Further, if a thixotropic resin solution is used as the resin liquid, the above-mentioned effect is further enhanced, which is more preferable. In addition, although there is a possibility that mixing of the resin from the transparent resin layer to the colored resin layer may occur,
Even if a little transparent resin is mixed, there is no concern that the coloring of the entire colored resin layer becomes thin, and the covering effect of the fiber reinforced colored resin layer on the surface resin layer is not affected.

In addition, even when the fiber-reinforced transparent resin layer is later laminated on the fiber-reinforced colored resin layer, the fiber-reinforced colored resin layer may be subjected to a thickening treatment or the fiber content of the fiber-reinforced colored resin layer may be increased. Although it is possible to prevent the colorant from being mixed into the fiber-reinforced transparent resin layer to some extent, the method of increasing the viscosity of the fiber-reinforced colored resin layer has the disadvantage that the number of processing steps increases and the production efficiency decreases. There is a method of increasing the fiber content of the fiber-reinforced colored resin layer, which requires extra reinforcing fibers and increases the fiber content too much due to restrictions on molding performance, the purpose of the fiber-reinforced resin product, required performance, etc. Not applicable if not possible.

In contrast, the method of the invention described above does not use any extra working steps or materials at all, and does not affect the quality performance of other working steps or products at all. Thus, a sheet for molding a fiber-reinforced resin having the following can be efficiently produced.

〔Example〕

Next, the present invention will be described below with reference to the drawings showing embodiments.

FIG. 1 shows a cross-sectional structure in a state where a covering film is attached to a fiber-reinforced resin molding sheet. The fiber-reinforced resin molding sheet 20 has a predetermined shape so as to constitute the surface of a target molded product. A colored surface resin layer 26, and a fiber-reinforced colored resin obtained by impregnating a reinforcing fiber 23 such as glass fiber with a thermosetting resin such as an unsaturated polyester resin colored in a similar color to the surface resin layer 26. A layer 24 and a fiber-reinforced transparent resin layer 22 in which a reinforcing fiber 23 is impregnated with a transparent thermosetting resin mixed with an ultraviolet curing agent are sequentially laminated. Coating films 30 and 34 such as vinylon films are attached to both surfaces of the sheet 20 for molding fiber-reinforced resin. The covering film 34 on the side of the surface resin layer 26 is effective for facilitating protection and handling of the molding sheet 20 or facilitating removal of the mold, but may be omitted.

As described above, the method for manufacturing the fiber-reinforced resin molding sheet 20 includes, as described above, when laminating the fiber-reinforced colored resin layer 24 on the fiber-reinforced transparent resin layer 22 in the manufacturing process, There is no particular limitation other than not performing the thickening treatment, for example, a method of sequentially laminating the fiber-reinforced transparent resin layer 22, the fiber-reinforced colored resin layer 24, and the surface resin layer 26 on the coating film 30 Is mentioned.

Note that the content of the reinforcing fibers in the fiber-reinforced colored resin layer 24 is
When the content is not less than% by weight, it is possible to more reliably prevent the colorant of the colored resin layer 24 from migrating to the transparent resin layer 22.

Next, a method of forming the fiber-reinforced resin forming sheet 20 manufactured as described above will be described.

FIG. 2 shows a molded state, in which a fiber-reinforced resin molding sheet 2 in which coating films 30 and 34 are adhered on a molding die 10 is shown.
0 is arranged, vacuum suction is performed from the vacuum suction port 14 of the forming die 10, the forming sheet 20 and the coating films 30 and 34 are drawn into the die, and shaped along the die surface 12. Forming sheet 20
Starts heat curing by heat transfer from the mold surface 12 at the time of contact with the mold surface 12. As shown in FIG. 4, when the projections 14 are present on the mold surface 12, the surface resin layer 26 is pressed or stretched to be locally thin at the apexes of the projections 14 (point P). However, the fiber-reinforced colored resin layer 24 exists inside the surface resin layer 26, and the fiber-reinforced colored resin layer 24 is
Since it contains the reinforcing fibers 23, it does not become thin, but maintains a sufficient thickness.

As shown in FIG. 3, an ultraviolet irradiation lamp 50 is irradiated to form a surface layer portion 29 of the fiber-reinforced transparent resin layer 22 on the side opposite to the mold surface 12 of the molding sheet 20 (a portion indicated by a cross in the figure). ) Is UV cured. At this stage, the heat curing of the entire molding sheet 20 due to heat transfer from the mold surface 12 side has not progressed so much, and the heat generated due to the heat curing has not become high enough to melt the coating film 30. .

After the irradiation of the ultraviolet irradiation lamp 50 is completed, the entire molding sheet 20 is cured through a normal heat curing step. At this stage, due to the heat generated by heat curing, the coating film 30 may be locally melted, but the surface layer portion 29 of the molding sheet 20 has already been cured, so that the conventional problem does not occur. .

The resin material of each layer is sufficiently heated and cured to form a molding sheet
After the mold 20 is formed into a desired shape, the molding sheet 20 and the covering films 30 and 34 are taken out from the mold 10 and subjected to predetermined trimming and external processing to obtain a fiber-reinforced resin molded article as shown in FIG. 28 is obtained. The covering films 30, 34 attached to the surface of the molding sheet 20 may be peeled off from the surface of the molded article.

As shown in FIG. 4, the molded article 28 obtained in this manner has a surface resin layer 26 that is locally thinned due to deformation during molding. Since it is sufficiently covered by the fiber-reinforced colored resin layer 24 disposed on the back side, a good finish can be obtained with a uniform colored appearance over the entire surface. In addition, the surface of the fiber-reinforced transparent resin layer 22 opposite to the surface resin layer 26 was also covered with the coating film 30 at the time of molding, and the surface layer portion 29 was cured by ultraviolet rays, so that bubbles could enter and the reinforcing fibers could be removed. Smooth and good finish with no fluff, unevenness, etc.

Next, the result of specifically manufacturing the fiber-reinforced resin molding sheet according to the present invention and evaluating the molding performance thereof will be described.

In the examples, “%” means “% by weight” unless otherwise specified.

-Materials used and molds- <Resin liquid for surface resin layer> 100 parts by weight of unsaturated polyester resin (Epolac N-325 manufactured by Nippon Shokubai Kagaku Kogyo Co., Ltd.) 10 parts by weight of titanium white 2 parts by weight of anhydrous silicic acid powder 15 parts by weight of styrene Part Thickener (magnesium oxide) 1 part by weight Heat curing agent 1 part by weight (tertiary butyl / peroxy 2-ethylhexanoate) <Resin liquid for fiber-reinforced colored resin layer> Unsaturated polyester resin 100 parts by weight (Epolac G- 103 Nippon Shokubai Chemical Co., Ltd.) Titanium white 10 parts by weight Thickener (magnesium oxide) 1 part by weight Heat curing agent 1 part by weight (tertiary butyl / peroxy 2-ethylhexanoate) <Resin for fiber reinforced transparent resin layer Liquid A> 100 parts by weight of unsaturated polyester resin (Epolac G-103 manufactured by Nippon Shokubai Chemical Co., Ltd.) 15 parts by weight of styrene Thickener (acid Magnesium chloride) 1 part by weight Heat curing agent 1 part by weight (tertiary butyl / peroxy 2-ethylhexanoate) Ultraviolet curing agent 1 part by weight (benzoin methyl ether) Compounded resin liquid viscosity = 1.2 poise <Fiber-reinforced transparent resin layer resin Liquid B> 100 parts by weight of unsaturated polyester resin (Epolac G-103 manufactured by Nippon Shokubai Chemical Co., Ltd.) 1 part by weight of thickener (magnesium oxide) 1 part by weight of heat curing agent (tertiary butyl / peroxy 2-ethylhexanoate) 1 part by weight of ultraviolet curing agent (benzoin methyl ether) Resin blended liquid viscosity = 6.7 poise <Resin liquid C for fiber reinforced transparent resin layer> 100 parts by weight of unsaturated polyester resin (Epolac G-103 manufactured by Nippon Shokubai Chemical Industry Co., Ltd.) Styrene 13 parts by weight Silicic anhydride fine powder 1 part by weight Thickener (magnesium oxide) 1 part by weight Heat curing 1 part by weight (tertiary butyl / peroxy 2-ethylhexanoate) UV curing agent 1 part by weight (benzoin methyl ether) Compounded resin liquid viscosity = 5.5 poise Compounded resin thixotropic index = 2.3 <Reinforcing fiber> Glass fiber mat (MC- 450A manufactured by Nitto Bo) <Coating film> Vinylon film (thickness: 30 microns) <Mold> An opening of 600 x 150 mm, depth of 75 mm, an exhaust port inside, and the following shape along the longitudinal direction Female mold with protrusions. The cross-sectional shape of the protrusion is an isosceles triangle with a vertex angle of 90 degrees and a height of 10 mm, and the vertex is rounded with a radius of curvature of 10 mm. A groove corresponding to the projection is formed on the molded product.

-Example 1-Two glass fiber mats and sap A for a fiber-reinforced transparent resin layer were used on the covering film 30 to obtain a glass content of about 30%.
The fiber-reinforced transparent resin layer 22 was formed. On top of that,
Using one glass fiber mat and a resin liquid for a fiber-reinforced colored resin layer, a fiber-reinforced colored resin layer 24 having a glass content of about 30% was laminated.

Next, after a thickening treatment at 40 ° C. for 3 hours, spacers made of a silicone rubber band having a thickness of 1 mm and a width of 10 mm were arranged on both ends of the upper surface of the fiber-reinforced colored resin layer 24. After supplying the resin liquid for the surface resin layer onto the fiber-reinforced colored resin layer 24 between the spacers, the glass rod passed over the spacer is moved along the spacer to even out the surface of the resin liquid, and the excess The resin solution was removed to form a surface resin layer 26. The obtained laminated sheet is aged at 40 ° C. for 12 hours to form a fiber-reinforced resin molding sheet.
20 were manufactured.

The resulting molding sheet 20 had a beautiful colored surface resin layer 26 on one side, and a fiber-reinforced transparent resin layer 22 showing a good transparent state on the other side. There was a fiber-reinforced colored resin layer 24 in the middle, and no transfer of the colorant from the fiber-reinforced colored resin layer 24 to the surface layer of the fiber-reinforced transparent resin layer 22 was observed.

Next, a sheet 20 for molding a fiber-reinforced resin was molded. At the opening of the mold 10 at a mold temperature of 90 ° C., the surface resin layer 26 side is the mold surface 12.
Side, the molding sheet 20 is mounted, the periphery is fixed, the inside is evacuated, the molding sheet 20 is suction-molded into a mold, and immediately with an ultraviolet irradiation lamp.
Irradiated with UV light for 90 seconds. Remove the mold 20 minutes after shaping,
When the covering film 30 was peeled off, the obtained molded product 28 was obtained.
Has no infiltration of bubbles and unnecessary irregularities on both the front and back,
It had a good appearance with a smooth and uniform color tone, and was also excellent in strength.

Example 2 A fiber-reinforced resin molding sheet 20 was produced in the same manner as in Example 1, except that the resin liquid B was used as the resin liquid for forming the fiber-reinforced transparent resin layer 22. The state of the obtained molding sheet 20 was as good as in Example 1.

The molding sheet 20 was molded in the same manner as in Example 1 except that the ultraviolet irradiation time was changed to 70 seconds.
In the same manner as in the above, the finished product was good.

Example 3 A sheet 20 for molding a fiber-reinforced resin was produced in the same manner as in Example 1, except that the resin liquid C was used as the resin liquid for forming the fiber-reinforced transparent resin layer 22. The state of the obtained molding sheet 20 was as good as in Example 1.

The molding sheet 20 was molded in the same manner as in Example 1 except that the ultraviolet irradiation time was changed to 50 seconds.
In the same manner as in the above, the finished product was good.

Example 4 In Example 1, the fiber-reinforced colored resin layer 24
After performing the thickening treatment at 3 ° C. for 3 hours, the surface resin layer 26 was formed. In this embodiment, the same procedure as in Example 1 was carried out except that the thickening treatment of the fiber-reinforced colored resin layer 24 was omitted. A sheet 20 for molding a fiber-reinforced resin was produced. The obtained molding sheet
The condition of No. 20 was as good as in Example 1.

When the molding sheet 20 was molded in the same manner as in Example 1, the surface resin layer 26 was compared with the molded article obtained in Example 1.
Although there is a slight glass pattern on the front surface, there is no bubble intrusion or unnecessary unevenness on both the front and back surfaces, it has a good appearance with a smooth and uniform color tone, and it has excellent strength. there were.

-Comparative example- After covering the coating film 34 on a smooth base and placing the same spacers on both ends, a resin solution for the surface resin layer was supplied between the spacers, and a glass rod passed over the spacers was used. By moving along the spacer, the surface of the resin liquid was leveled to remove the excess resin liquid, and the surface resin layer 26 was formed. After increasing the viscosity at 40 ° C. for 3 hours, the fiber-reinforced colored resin layer 24 having a glass content of about 30% was coated on the surface resin layer 26 using one glass fiber mat and a resin liquid for the fiber-reinforced colored resin layer. Was formed. Then, immediately using two glass fiber mats and the resin liquid B for a fiber-reinforced transparent resin layer, a fiber-reinforced transparent resin layer 22 having a glass content of about 30% was laminated. At this stage, a part where the transparency of the fiber-reinforced colored resin layer 24 was lost due to mixing of the colorant of the fiber-reinforced colored resin layer 24 into a part of the fiber-reinforced transparent resin layer 22 was observed. Further, a small amount of the resin liquid B for a fiber-reinforced transparent resin layer was supplied thereon to facilitate defoaming, covered with the coating film 30, and defoamed with a roll. In addition, the lamination of each layer was performed using a grooving defoaming roll according to a conventional method. The whole obtained laminated sheet was aged at 40 ° C. for 12 hours to produce a sheet 20 for molding a fiber-reinforced resin. In the state of the obtained molding sheet 20, a beautiful surface resin layer 26 appeared on one side, but the fiber-reinforced transparent resin layer 22 on the other side had a fiber-reinforced colored resin layer 24.
And the transparency of the entire surface was lost.

When the molding sheet 20 was molded in the same manner as in Example 1, the coating film 30 covering the fiber-reinforced transparent resin layer 22 was broken about 4 minutes after the shaping. The obtained molded article 28 had a remarkably fuzzy surface on the fiber-reinforced transparent resin layer 22 side. Comparing this result with the result of each embodiment, it is clear that the advantage is that the fiber-reinforced transparent resin layer 22 is formed first, and the fiber-reinforced colored resin layer 24 is laminated thereon.

〔The invention's effect〕

According to the method for manufacturing a fiber-reinforced resin molding sheet according to the present invention described above, the fiber-reinforced transparent resin layer is formed, and then the fiber-reinforced colored resin layer is laminated thereon. The coloring agent blended in the layer does not migrate into and penetrate the surface layer of the fiber-reinforced transparent resin layer. Accordingly, the fiber-reinforced resin molding sheet to be produced has good transparency, particularly in the surface layer portion of the fiber-reinforced transparent resin layer, and has extremely good ultraviolet light absorption, that is, ultraviolet curability.

As a result, the fiber-reinforced resin molding sheet is provided with the fiber-reinforced colored resin layer adjacent to the surface resin layer, so that even if the surface resin layer is locally thinned during molding, the colored state of the surface is not changed. Thus, the entire molded article becomes uniform and good, and a very excellent finish in appearance can be obtained. In addition, the UV-curable fiber-reinforced transparent resin layer disposed on the surface opposite to the surface resin layer improves the finish on the surface on this side. In other words, the coating film is pasted on the surface of the molding sheet, and the surface layer is cured by irradiation with ultraviolet rays during molding. This can be reliably prevented from occurring.

As a result, the use of the fiber-reinforced resin molding sheet produced by the method according to the present invention makes it possible to produce a fiber-reinforced resin molded product having a good surface finish and excellent quality performance.

Moreover, since the method of the present invention only needs to specify the order of lamination of the fiber-reinforced transparent resin layer and the fiber-reinforced colored resin layer, the production steps and work time of the entire sheet for molding the fiber-reinforced resin do not increase, It is a highly productive and economical method.

[Brief description of the drawings]

1 is a sectional view of a sheet for molding a fiber-reinforced resin according to an embodiment of the present invention, FIG. 2 is a schematic sectional view showing a molding method, FIG. 3 is an enlarged sectional view of a main part during molding, and FIG. Is a cross-sectional view of a portion where the surface resin layer is thinned, FIG. 5 is a cross-sectional view of the obtained molded product, FIG. 6 is a cross-sectional view showing a molding state of a conventional example,
FIG. 7 is an enlarged sectional view of a main part. 20: Fiber-reinforced resin molding sheet, 22: Fiber-reinforced transparent resin layer, 23: Reinforced fiber, 24: Fiber-reinforced colored resin layer,
26: Surface resin layer, 28: Molded product, 30, 34: Coating film

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kuhisa Abe 1-4-1, Chuo, Wako-shi, Saitama Pref. Honda Research Institute Co., Ltd. (72) Inventor Kenichi Ueda 5-8, Nishimitabicho, Suita-shi, Osaka Nippon Shokubai Chemical Industry Co., Ltd. Resin Research Laboratory (72) Inventor Yuji Inagaki 5-8 Nishiburicho, Suita City, Osaka Prefecture Nippon Shokubai Chemical Industry Co., Ltd. Resin Research Laboratory (72) Inventor Daisuke Atobe Nishi Suita City, Osaka Prefecture No. 5-8 Onari-cho Nippon Shokubai Chemical Co., Ltd. Resin Research Laboratory (58) Field surveyed (Int. Cl. ⁶ , DB name) B29B 11/16 B29B 15/08-15/14 C08J 5/24 B29C 70 / 00-70/88

Claims (1)

(57) [Claims] 1. A sheet for molding a fiber-reinforced resin, which is shaped along a mold surface of a mold, heat-cured and molded, comprising a colored surface resin layer disposed on one surface of the molding sheet. A fiber-reinforced colored resin layer disposed adjacent to the inside of the surface resin layer and colored in a similar color to the surface resin layer; and a UV-curable fiber-reinforced transparent resin disposed on the other surface of the molding sheet. A method for producing a sheet for molding a fiber-reinforced resin comprising at least a layer comprising: forming a fiber-reinforced transparent resin layer, after forming the fiber-reinforced transparent resin layer, A method for producing a sheet for molding a fiber-reinforced resin, comprising: laminating a fiber-reinforced colored resin layer on the surface of the layer, and then, if necessary, subjecting these layers to a thickening treatment, followed by laminating a surface resin layer.