JP6098086B2 - Laminated sheet for carbon fiber reinforced plastic, laminated composite material and method for producing the same - Google Patents

Description

  The present invention relates to a laminated sheet for carbon fiber reinforced plastic that can be laminated with high adhesion to carbon fiber reinforced plastic. Furthermore, this invention relates to the said laminated composite material which laminated | stacked the laminated sheet for carbon fiber reinforced plastics on carbon fiber reinforced plastic, and its manufacturing method.

In recent years, molded products using carbon fiber reinforced plastic (CFRP) composite materials have been proposed as components for sports equipment, automobiles, ships, aircraft, etc. that are subject to large impacts and deformation stresses. Has been actively adopted in certain fields. This CFRP composite material is manufactured by impregnating a carbon fiber with a matrix resin such as a thermoplastic resin or a thermosetting resin, and curing it as necessary. It is a tough member that is relatively lightweight.
On the other hand, from the viewpoint of designability, elaborate three-dimensional designs that take advantage of the beautiful luster of the matrix resin and the texture of the carbon fiber are preferred. Especially in the field of sports equipment and sports cars, CFRP is Molded products that take advantage of their inherent design are preferred.
As an example of a molded product that takes advantage of such design properties of CFRP, Patent Document 1 discloses a surface material obtained by laminating a thermoplastic resin film on the surface of CFRP and applying heat pressure, and molding using the same. The product is disclosed.

JP 10-138354 A

However, in the surface material described in Patent Document 1, a technique for increasing the adhesion between CFRP and the thermoplastic resin film has not been established, and the adhesion between CFRP and the thermoplastic resin film may be insufficient. However, there is still room for further study on the technique of laminating the thermoplastic resin film with high adhesion.
Under such circumstances, the present invention provides a laminated composite material having excellent adhesion between a carbon fiber reinforced plastic layer and a base material layer, a method for producing the same, and a carbon fiber reinforced plastic capable of providing the laminated composite material. It is an object to provide a laminated sheet for use.

  As a result of intensive studies to solve the above problems, the inventor of the present invention uses a laminated sheet for carbon fiber reinforced plastic having a heat-adhesive layer using a resin having a softening point of 80 ° C. or less on a substrate. It has been found that the above-mentioned problems can be solved by decorating the CFRP. The present invention has been completed based on such findings.

That is, the present invention provides the following inventions.
Item 1. A laminated sheet for carbon fiber reinforced plastic having a thermal adhesive layer on a substrate, wherein the thermal adhesive layer has a softening point of 80 ° C or lower.
Item 2. Item 2. The laminated sheet for carbon fiber-reinforced plastics according to Item 1, wherein the softening point of the substrate is more than 80 ° C.
Item 3. Item 3. The laminated sheet for carbon fiber reinforced plastics according to Item 1 or 2, wherein the thermal adhesive layer is formed of a polyurethane-based resin.
Item 4. Item 4. The laminated sheet for carbon fiber reinforced plastic according to any one of Items 1 to 3, wherein a transparent resin film layer is provided between the substrate and the heat-adhesive layer.
Item 5. One or more layers of a prepreg obtained by impregnating a carbon fiber with a matrix resin are disposed. On the prepreg, the laminated sheet for carbon fiber reinforced plastic according to any one of Items 1 to 4, wherein the heat-adhesive layer side is the prepreg side. A method for producing a laminated composite material, wherein the laminated composite material is integrally molded after being laminated.
Item 6. Item 6. The method for producing a laminated composite material according to Item 5, wherein the integral molding is performed by heat and pressure molding.
Item 7. A laminated composite material comprising a carbon fiber reinforced plastic layer, a heat-adhesive layer having a softening point of 80 ° C. or less, and a substrate in this order.
Item 8. Item 8. The laminated composite material according to Item 7, wherein the peel strength between the carbon fiber reinforced plastic layer and the substrate is 10 kgf / cm ² or more.

  According to the laminated sheet for carbon fiber reinforced plastics of the present invention, a laminated composite material having excellent adhesion between the carbon fiber reinforced plastic layer and the base material layer, a method for producing the laminated composite material, and carbon capable of providing the laminated composite material A laminated sheet for fiber-reinforced plastic can be provided.

  Further, in the laminated sheet for carbon fiber reinforced plastic of the present invention, the laminated composite material is laminated with the carbon fiber reinforced plastic by adjusting the kind and thickness of the thermoplastic resin of the base material or by providing a transparent resin film. Can be provided with an appearance property excellent in surface smoothness and gloss, so that it becomes possible to provide a laminated composite material having a further enhanced design effect.

It is a schematic diagram which shows the cross section of the one aspect | mode of the laminated composite material of this invention. It is a schematic diagram which shows the cross section of the one aspect | mode of the laminated composite material of this invention.

<Laminated sheet for carbon fiber reinforced plastic>
The laminated sheet for carbon fiber reinforced plastic of the present invention is a laminated sheet for carbon fiber reinforced plastic having a heat-adhesive layer on a substrate, wherein the softening point of the heat-adhesive layer is 80 ° C. or less. And

[Base material]
As the base material, a resin film made of a thermoplastic resin is typically used. The thermoplastic resin is generally a polyester resin such as acrylonitrile-butadiene-styrene resin (hereinafter referred to as “ABS resin”), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), or the like. Polyolefin resins such as acrylic resin, polypropylene and polyethylene, polycarbonate resin, vinyl chloride resin and the like are used, and polyester resin is preferably used from the viewpoint of transparency, hardness, heat resistance and the like. Moreover, a base material can be used as a single layer film of these resins, or a multilayer film by the same kind or different resin.

  Although it does not restrict | limit especially about the softening point of the thermoplastic resin which comprises a base material, For example, 60 degreeC or more is mentioned. In particular, the thermoplastic resin constituting the base material has a softening point of more than 80 ° C (more preferably more than 100 ° C, more preferably more than 120 ° C, most preferably more than 150 ° C, particularly preferably more than 180 ° C). In such a case, the laminated composite material obtained by using this has an adhesive property, and the unevenness derived from the texture of the carbon fiber does not appear on the surface, so that a laminated composite material excellent in smoothness is obtained. Therefore, it is preferable. The upper limit value of the softening point of the thermoplastic resin constituting the base material is not particularly limited, but is, for example, 230 ° C, preferably 200 ° C. In addition, the said softening point is a value measured according to "JIS K5601-2-2 paint component test method-Part 2: Component analysis in a solvent soluble material-Section 2: Softening point (ring ball method)". .

  The thickness of the substrate is selected according to the application and is not particularly limited. However, considering operability, workability, cost, etc., 10 to 500 μm is preferable, 20 to 300 μm is more preferable, and 25 to 250 μm is still more preferable.

  Further, from the viewpoint of providing excellent surface smoothness even when a transparent resin film layer to be described later is not provided, the substrate is made of a polyester resin, preferably polyethylene terephthalate, and has a thickness of 50 μm or more, preferably 75 to A film of 300 μm, more preferably 75 to 250 μm is preferably used.

  These base materials can be subjected to physical or chemical surface treatment such as an oxidation method or an unevenness method on one side or both sides, if desired, in order to improve the adhesion with the layer provided thereon.

  Examples of the oxidation method include corona discharge treatment, chromium oxidation treatment, flame treatment, hot air treatment, ozone / ultraviolet treatment method, and examples of the unevenness method include a sand blast method and a solvent treatment method. These surface treatments are appropriately selected depending on the type of substrate, but generally, a corona discharge treatment method is preferably used from the viewpoints of effects and operability.

  Further, the base material may be a colored one containing a colorant in a range in which carbon fibers are not concealed in advance.

[Thermal adhesive layer]
The laminated sheet for carbon fiber reinforced plastic of the present invention has a thermal adhesive layer on the substrate in order to improve the adhesion with the carbon fiber reinforced plastic layer. The heat-adhesive layer can be formed by applying various inks to the base material, or can be formed by printing using a printing machine, and is provided on the entire surface of the base material. It may be provided partially on the substrate.

  Examples of the method for forming the heat-adhesive layer include ordinary printing methods such as gravure printing, and ordinary coating methods such as gravure coating, gravure reverse coating, gravure offset coating, spinner coating, roll coating, and reverse roll coating. It is done.

As the resin used for the heat-adhesive layer, it is necessary to use a resin having a softening point of 80 ° C. or less (preferably 70 ° C. or less, more preferably −20 ° C. or more and 70 ° C. or less, particularly preferably 0 ° C. or more and 30 ° C. or less). Yes, for example, polyurethane resin, vinyl chloride / vinyl acetate copolymer resin, vinyl chloride / vinyl acetate / acrylic copolymer resin, chlorinated polypropylene resin, acrylic resin, polyester resin, polyamide resin, Any one of butyral resins, polystyrene resins, nitrocellulose resins, cellulose acetate resins and the like may be used alone or in admixture of two or more. In addition, when mixing and using 2 or more types of resin, the average softening point temperature according to a mixing ratio should just be 80 degrees C or less.
Here, the softening point is measured using “JIS K5601-2-2 paint component test method—Part 2: Component analysis in solvent-soluble matter—Section 2: Softening point (ring-ball method)”. Is. By selecting a heat-adhesive layer having a softening point of 80 ° C. or lower, it becomes possible to improve the adhesion to the carbon fiber reinforced plastic. On the other hand, when the softening point of the heat-adhesive layer is more than 80 ° C., even if a laminated composite material is produced using a laminated sheet for carbon fiber reinforced plastic, the colored layer does not follow the three-dimensional shape of the carbon fiber. Inferior to sex.

  Among the resins having a softening point of 80 ° C. or less used for the heat-adhesive layer, polyurethane is preferable from the viewpoint of further improving the adhesion to the carbon fiber reinforced plastic and further providing excellent surface smoothness and gloss. Resin and vinyl chloride / vinyl acetate copolymer resin, more preferably polyurethane resin.

  As the polyurethane resin, specifically, a resin obtained by curing a polyol compound as a main component and an isocyanate compound as a crosslinking agent (curing agent) is used.

  The polyol compound used as the main component of the polyurethane-based resin may be a compound having two or more hydroxyl groups in the molecule, and specifically, polyester polyol, polyester polyurethane polyol, polyether polyol, polyether polyurethane polyol. Etc. Among these polyol compounds, polyester polyol is preferable. Examples of the number of hydroxyl groups contained in these polyol compounds include 2 to 10, preferably 2 to 6, per molecule. These polyol compounds may be used individually by 1 type, and may be used in combination of 2 or more type.

  Specific examples of isocyanate compounds used as curing agents for polyurethane resins include diphenylmethane diisocyanate (MDI), polyphenylmethane diisocyanate (polymeric MDI), toluene diisocyanate (TDI), and hexamethylene diisocyanate (HDI). Bis (4-isocyanatocyclohexyl) methane (H12MDI), isophorone diisocyanate (IPDI), 1,5-naphthalene diisocyanate (1,5-NDI), 3,3′-dimethyl-4,4′-diphenylene diisocyanate (TODI) ), Aromatic diisocyanates such as xylene diisocyanate (XDI); tramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate Aliphatic diisocyanates such as isophorone diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), include diisocyanates such as alicyclic diisocyanates such as isophorone diisocyanate. These isocyanate compounds may be used individually by 1 type, and may be used in combination of 2 or more type.

  Among these polyurethane resins, a polyurethane resin obtained by curing a polyester polyol with diisocyanate is preferable from the viewpoint of providing better adhesion to carbon fiber reinforced plastic, surface smoothness, and gloss. Is a polyurethane resin obtained by curing a polyester polyol with an alicyclic diisocyanate; particularly preferably a polyurethane resin obtained by curing a polyester polyol having 2 to 6 hydroxyl groups per molecule with hexamethylene diisocyanate.

  Further, the ratio of the polyol compound and the isocyanate compound forming the polyurethane resin is appropriately set so as to satisfy the softening point described above. For example, the isocyanate of the isocyanate compound per 1 mol of the hydroxyl group of the polyol compound. The group ratio is 0.5 to 30, preferably 0.8 to 2.

  The thermal adhesive layer may be appropriately mixed with a colorant such as a pigment and a dye, an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, and a curing agent as necessary.

  Colorants include carbon black (black), iron black, titanium white, antimony white, yellow lead, titanium yellow, petal, cadmium red, ultramarine, cobalt blue and other inorganic pigments, quinacridone red, isoindolinone yellow, phthalocyanine Organic pigments or dyes such as blue, metal pigments made of scaly foil pieces such as aluminum and brass, pearlescent pigments made of scaly foil pieces such as titanium dioxide-coated mica and basic lead carbonate, and the like are used.

  The thickness of the heat-adhesive layer is preferably from 0.1 to 20 μm, more preferably from 0.1 to 15 μm, still more preferably from 0.3 to 10 μm. When the thickness of the heat-adhesive layer is 0.1 μm or more, the adhesion to the carbon fiber reinforced plastic layer is good, and when it is 20 μm or less, the drying time after integral molding can be shortened, and the productivity is improved. To do.

[Colored layer]
The laminated sheet for carbon fiber reinforced plastic of the present invention may further have a colored layer as required.

  The colored layer can be provided between the substrate and the heat-adhesive layer, or on the surface of the substrate opposite to the heat-adhesive layer, and from the viewpoint of scratch resistance, between the substrate and the heat-adhesive layer. It is preferable to provide in.

  The colored layer can be formed by coating on a substrate or a heat-adhesive layer using various inks, or can be formed by printing using a printing machine. It may be provided on the entire surface of the adhesive layer or may be provided partially.

  Examples of the method for forming the colored layer include ordinary printing methods such as gravure printing, and ordinary coating methods such as gravure coating, gravure reverse coating, gravure offset coating, spinner coating, roll coating, and reverse roll coating.

  The colored layer is formed as a picture layer and / or a colored solid layer, and the pattern formed on the picture layer is a stone imitating the surface of a rock such as a wood grain pattern or a marble pattern (for example, a travertine marble pattern). There are eye patterns, fabric patterns simulating cloth and cloth-like patterns, tiled patterns, brickwork patterns, etc. There are also patterns such as parquet and patchwork that combine these. These patterns are formed by multicolor printing with the usual yellow, red, blue and black process colors, as well as by multicolor printing with special colors prepared by preparing the individual color plates constituting the pattern. Is done.

  The colored solid layer is formed as a uniform and uniform colored layer on the base material, and gives the intended color to the entire surface of the base material. Usually, it is formed with an opaque color, but it can also be formed with a colored transparent color and make use of the pattern of the base.

  The thickness of the colored layer is preferably from 0.1 to 20 μm, more preferably from 0.1 to 15 μm, still more preferably from 0.3 to 10 μm. When the thickness of the colored layer is 0.1 μm or more, the decorative effect on the laminated composite material is good, and when it is 20 μm or less, the three-dimensional shape of the carbon fiber is easy to see.

[Transparent resin film layer]
The transparent resin film layer is used for the purpose of improving the surface smoothness and gloss, and improving the three-dimensional moldability (shape retention after three-dimensional molding) as needed between the substrate and the heat-adhesive layer. In the case where a colored layer is provided between the substrate and the heat-adhesive layer, the layer is provided between the substrate and the color layer or between the color layer and the heat-adhesive layer.

  As a method of forming the transparent resin film layer, an adhesive may be used to adhere to another layer, or the transparent resin film layer may be adhered without using an adhesive. When laminating via an adhesive, examples of the adhesive used include polyester resin, polyether resin, polyurethane resin, epoxy resin, phenol resin resin, polyamide resin, polyolefin resin, and polyresin. Examples thereof include vinyl acetate resin, cellulose resin, (meth) acrylic resin, polyimide resin, amino resin, rubber, and silicon resin. Moreover, when making it adhere | attach without an adhesive agent, it can carry out by methods, such as an extrusion method, a sand-lamination method, and a thermal lamination method.

  The resin film forming the transparent resin film layer is appropriately selected according to transparency, three-dimensional formability, shape stability, chemical resistance, etc., but usually a thermoplastic resin is used. The thermoplastic resin is not particularly limited. For example, acrylic resin, polypropylene resin (PP), polyolefin resin such as polyethylene, polycarbonate resin, ABS resin, polyester resin such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), A vinyl chloride resin etc. are mentioned. Among these, polyolefin resin is preferable, and polypropylene is more preferable.

  Although it does not restrict | limit especially about the softening point of the resin film which forms a transparent resin film layer, For example, 60 degreeC or more, Preferably 80-150 degreeC is mentioned.

  The transparent resin film layer is subjected to physical or chemical surface treatment, such as an oxidation method or an unevenness method, on one or both sides as necessary in order to improve the adhesion with other layers in contact with the transparent resin film layer. May be. These physical or chemical surface treatments are the same as the surface treatments applied to the base film layer.

  Although it does not restrict | limit especially about the thickness of a transparent resin film layer, For example, 15-500 micrometers, Preferably it is 30-300 micrometers.

<Method for producing laminated composite material>
The above-mentioned laminated sheet for carbon fiber reinforced plastic can be used for producing a laminated composite material.

  In the method for producing a laminated composite material of the present invention, one or more layers of a prepreg obtained by impregnating a carbon fiber with a matrix resin are arranged, and the above-mentioned laminated sheet for carbon fiber reinforced plastic is placed on the prepreg, After lamination so as to face the prepreg side, it is integrally formed.

[Matrix resin]
The matrix resin is not particularly limited as long as it can be used for a carbon fiber prepreg. For example, a thermosetting resin such as an epoxy resin, an unsaturated polyester resin, a phenol resin, a silicone resin, a urethane resin, or a polyimide resin, , Polysulfone, polyethersulfone, polyetherimide, polyimide and other thermoplastic resins and various thermoplastic elastomers can be used alone or in combination of two or more, and epoxy resins are particularly preferred.

[Carbon fiber]
The carbon fiber used in the present invention is not particularly limited, and any of polyacrylonitrile (PAN) type, pitch type and the like may be used, and those in which they are mixed may be used. Further, the carbon fiber weave may be any one of long fibers arranged in one direction, bi-directional woven fabric, multiaxial woven fabric, non-woven fabric, mat, knit, braided string, and the like. The long fiber here means a single fiber or a fiber bundle substantially continuous for 10 mm or more.

[Prepreg]
The prepreg is a molded intermediate base material in which a reinforcing fiber is impregnated with a matrix resin. In the present invention, a carbon fiber is used as the reinforcing fiber. A carbon fiber reinforced plastic layer can be obtained by laminating and curing these prepregs as necessary. Of course, the prepreg may be used as a single layer, but a plurality of prepregs may be laminated and used.

[Integrated molding method]
When the prepreg and the above-described laminated sheet for carbon fiber reinforced plastic are integrally formed, it is preferable to perform the integral forming by heating and pressing. When thermosetting resin such as epoxy resin is used as the matrix resin by performing heat and pressure molding, the matrix resin can be heat-cured simultaneously with integral molding, and a thermoplastic resin is used as the matrix resin. In this case, since the matrix resin can be integrally molded while being softened, the production efficiency is excellent, and the adhesion in the interface region between the matrix resin and the heat-adhesive layer is good.

  Here, press molding method, autoclave molding method, bagging molding method, wrapping tape method, internal pressure molding method, etc. can be adopted as the heat and pressure molding method, but at the same time as the integral molding, adhesion between the matrix resin and the thermal adhesive layer From the viewpoint of enhancing the properties, a press molding method is preferable.

  The molding temperature (or curing time) in the heat and pressure molding method may be appropriately selected depending on the selected matrix resin. For example, in the case of an epoxy resin composition, depending on the type of curing agent contained, etc. A temperature of 220 ° C. is preferred. If the molding temperature is too low, sufficient rapid curability may not be obtained. Conversely, if the molding temperature is too high, warping due to thermal strain may be likely to occur.

  Moreover, as a pressure shape | molded by the press molding method, although it changes with thickness of a prepreg etc., the pressure of 0.1-1 Mpa is preferable normally. If the molding pressure is too low, heat may not be sufficiently transmitted to the inside of the prepreg, resulting in uncured locally or warping. On the other hand, if it is too high, the resin will flow out before it hardens, and voids may be generated in the carbon fiber reinforced plastic.

<Laminated composite material>
The laminated composite material of the present invention obtained by the above-described production method is characterized by having a carbon fiber reinforced plastic layer, a thermal adhesive layer having a softening point of 80 ° C. or less, and a substrate in this order.
The structure of the laminated composite material of the present invention will be described in detail with reference to FIGS. In the example shown in FIG. 1, a thermal adhesive layer 12 and a base material 13 are sequentially laminated on a carbon fiber reinforced plastic layer 11. In the example shown in FIG. 2, a thermal adhesive layer 12, a transparent resin film layer 14, a colored layer 15, and a base material 13 are sequentially laminated on the carbon fiber reinforced plastic layer 11.

[Carbon fiber reinforced plastic layer]
As described above, the carbon fiber reinforced plastic layer is formed by laminating and curing a prepreg as necessary.

[Thermal adhesive layer]
Since the heat-adhesive layer of the laminated composite material according to the present invention follows the three-dimensional shape of the carbon fiber by the above-described integral molding, the adhesiveness between the base material and the carbon fiber-reinforced plastic layer is good. More specifically, the peel strength between the carbon fiber reinforced plastic layer and the substrate is preferably 10 kgf / cm ² or more, and more preferably 15 kgf / cm ² or more.
In addition, the said peeling strength is the value measured based on the plane tensile test described in the "special processing plywood" of the Japanese agricultural and forestry standard "Japanese agricultural and forestry standard of plywood".

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by this example.

<Measurement method>
(1) Softening point Measured according to "JIS K5601-2-2 Paint component test method-Part 2: Component analysis in solvent-soluble matter-Section 2: Softening point (ring and ball method)".

<Evaluation method>
(1) Gloss For the laminated composite materials obtained in each of the examples and comparative examples, the gloss value of the substrate-side surface is measured using a gloss meter (Micro-tri-gloss manufactured by Big Gardner) at an incident angle of 60 °. Was measured. The higher the value, the higher the gloss.
(Double-circle): The gloss value was 80 or more, and it was highly glossy.
A: The gloss value was 60 or more and less than 80.
X: The gloss value was less than 60.

(2) Surface smoothness The shape of the fluorescent lamp reflected on the substrate-side surface of the laminated composite material obtained in each Example / Comparative Example was visually confirmed, and the sharpness was evaluated according to the following criteria.
A: The fluorescent lamp was clearly reflected without distortion.
○: A slight unevenness emerged on the surface along the texture of the carbon fiber, but the fluorescent lamp appeared fine.
Δ: Concavities and convexities emerged locally on the surface along the carbon fiber weave, but the fluorescent light was clearly reflected in the portions other than the concavities and convexities.
X: Concavities and convexities and pinhole-like defects were present on the entire surface along the carbon fiber weave, and the fluorescent lamp was also blurred.

(3) Adhesion (part 1)
The surface (base material side) of the laminated composite material obtained in each Example / Comparative Example was cut into an X shape with a cutter knife, and the cello tape (registered trademark) “CT-24” manufactured by Nichiban Co., Ltd. Side) and then peeled off rapidly. The adhesion was evaluated according to the following criteria.
○: No peeling of the substrate.
X: There exists peeling of a base material.

(4) Adhesion (part 2)
About the laminated composite material obtained by each Example and the comparative example, the peeling strength of a carbon fiber reinforced plastic layer and a base material was measured with the following measuring method (JAS plywood standard conformity).
(Measuring method)
After cutting the molded body into 5cm square and pasting a 2cm square metal jig on the film surface with cyanoacrylate adhesive (Toa Gosei Co., Ltd. Aron Alpha General) and curing for 24 hours at room temperature (about 23 ° C) Cut with a cutter knife to the molded body along the metal jig, pull it in the vertical direction with respect to the test piece using a measurement test equipment, and visually observe and evaluate the peeling interface at that time, and tensile strength Was measured. The unit of measurement is kgf / cm ² .
Moreover, about the result of having observed the peeling interface visually, it classified according to the following criteria.
○: Cohesive failure of the base material or cohesive failure of the molded product ×: Cohesive failure of the molded product ×: Peeling of the thermal adhesive layer or interface between the base material and the molded product

Example 1
(Manufacture of laminated sheets for carbon fiber reinforced plastics)
Using a polyethylene terephthalate base material (thickness: 188 μm, softening point:> 180 ° C.) and an ink containing an acrylic resin (softening point: 67 ° C.) and an aluminum pigment, the entire surface was solid-printed to form a colored layer. . Next, on the colored layer, polyester polyol (OH value 60 mgKOH / g, weight average molecular weight 2,300) and 1,6-hexamethylene diisocyanate are mixed with 1,6-hexamethylene diisocyanate isocyanate per mol of hydroxyl group of the polyester polyol. A polyurethane resin composition containing 1 mol of a group is applied by gravure printing, and the resin composition is cured to form a heat-adhesive layer (thickness: 2 μm, softening point 30 ° C.), carbon fiber A laminated sheet for reinforced plastic was obtained.

(Manufacture of laminated composite materials)
Six layers of prepregs made by impregnating carbon fiber with an uncured epoxy resin were laminated, and the laminated sheet for carbon fiber reinforced plastic was laminated on the laminated prepreg so that the heat-adhesive layer side was directed to the prepreg side. Then, it integrally molded by heat and pressure molding (curing temperature: 130 ° C., curing time: 2 hours, pressure: 0.49 MPa) to obtain a plate-shaped laminated composite material.

Example 2
A polyethylene terephthalate base material (thickness: 75 μm, softening point:> 180 ° C.) was used as the base material, and a vinyl chloride-vinyl acetate copolymer (thickness: 4 μm, softening point 60 ° C.) was used as the thermal adhesive layer. Except for this, a laminated sheet for carbon fiber reinforced plastic and a laminated composite material were produced in the same manner as in Example 1 above.

Example 3
Polyethylene terephthalate substrate (thickness: 75 μm, softening point:> 180 ° C.) as a substrate, polyester polyol (OH value 30 mg KOH / g, weight average molecular weight 1,000) and 1,6-hexamethylene diisocyanate, A heat-adhesive layer (thickness: 2 μm, softening point 0 ° C.) using a polyurethane-based resin composition containing 1,6-hexamethylene diisocyanate in an amount of 0.8 mol per mol of hydroxyl group of polyester polyol A laminated sheet for carbon fiber reinforced plastic and a laminated composite material were produced in the same manner as in Example 1 except that it was formed.

Example 4
A laminated sheet for carbon fiber reinforced plastic and a laminated composite material were produced in the same manner as in Example 3 except that a polyethylene terephthalate substrate (thickness: 50 μm, softening point:> 180 ° C.) was used as the substrate. .

Example 5
A laminated sheet for carbon fiber reinforced plastic and a laminated composite material were produced in the same manner as in Example 3 except that an acrylic resin substrate (thickness: 120 μm, softening point: 80 ° C.) was used as the substrate. .

Example 6
A laminated sheet for carbon fiber reinforced plastic and a laminated composite material were produced in the same manner as in Example 3 except that a polypropylene substrate (thickness: 80 μm, softening point: 60 ° C.) was used as the substrate.

Example 7
Using a polyethylene terephthalate base material (thickness: 50 μm, softening point:> 180 ° C.) and an ink containing an acrylic resin (softening point: 67 ° C.) and an aluminum pigment, the entire surface was solid-printed to form a colored layer. . Next, a transparent resin film layer made of polypropylene (thickness: 200 μm, softening point: 108 ° C.) is applied onto the colored layer by applying a urethane resin adhesive by gravure coating so as to have a film thickness of 10 μm. I let you. Next, a heat-adhesive layer (thickness: 3 μm, softening point 30 ° C.) is formed on the transparent resin film side on the light resin film layer in the same manner as in Example 3 above, and for carbon fiber reinforced plastics A laminated sheet was obtained.
Furthermore, a laminated composite material was produced in the same manner as in the above-described example, using the obtained carbon fiber reinforced plastic laminated sheet.

Example 8
Example above, except that a polypropylene base material (thickness: 60 μm, softening point: 130 ° C.) was used as the base material and a polypropylene film (thickness: 80 μm, softening point: 108 ° C.) was used as the transparent resin film layer. In the same manner as in No. 7, a laminated sheet for carbon fiber reinforced plastic and a laminated composite material were produced.

Comparative Example 1
A laminated sheet for carbon fiber reinforced plastic and a laminated composite material were produced in the same manner as in Example 1 except that the thermal adhesive layer was not formed.

Comparative Example 2
Other than using an acrylic resin base material (thickness: 125 μm, softening point: 100 ° C.) as the base material and a layer made of acrylic resin (thickness: 6 μm, softening point 90 ° C.) as the heat-adhesive layer Produced a laminated sheet for carbon fiber reinforced plastic and a laminated composite material in the same manner as in Example 1 above.

Comparative Example 3
A carbon fiber was prepared in the same manner as in Example 1 except that an acrylonitrile-butadiene-styrene base material (thickness: 400 μm, softening point 80 ° C.) was used as the base material, and no thermal adhesive layer was formed. A laminated sheet for reinforced plastic and a laminated composite material were produced.

<Evaluation results>
Table 1 shows the results of evaluating the gloss, surface smoothness, adhesion and peel strength of the laminated composite materials obtained in each Example and Comparative Example based on the above evaluation methods. From this result, when the softening point of the heat-adhesive layer is 80 ° C. or lower, particularly 0 to 60 ° C., the adhesiveness of the laminated sheet for carbon fiber reinforced plastic is significantly improved with respect to the carbon fiber reinforced plastic. It became clear. Furthermore, it was confirmed that when polyester having a thickness of 75 μm or more was used as the base material and when a transparent resin film layer was provided, the smoothness and gloss were improved and the design effect was enhanced.

  The laminated sheet for carbon fiber reinforced plastic of the present invention is an interior material or exterior material of a vehicle such as an automobile, a fitting such as a window frame or a door frame, an interior material of a building such as a wall, a floor, or a ceiling, a television receiver, and an air conditioner. It is suitably used for the manufacture of laminated composite materials used for home appliances such as machines, and housings and containers of personal computers.

10. Laminated composite material 11. Carbon fiber reinforced plastic layer 12. Thermal adhesive layer 13. Base material 14. Transparent resin film layer 15. Colored layer

Claims (9)

A laminated sheet for carbon fiber reinforced plastic having a heat-adhesive layer on a substrate, wherein the heat-adhesive layer has a softening point of 60 ° C. or less, and the heat-adhesive layer has a thickness of 0.1 to 20 μm. A laminated sheet for carbon fiber reinforced plastic, characterized by being.   The laminated sheet for carbon fiber reinforced plastics according to claim 1, wherein the softening point of the substrate is higher than 80 ° C.   The laminated sheet for carbon fiber reinforced plastics according to claim 1 or 2, wherein the thermal adhesive layer is formed of a polyurethane-based resin.   The laminated sheet for carbon fiber reinforced plastics according to any one of claims 1 to 3, wherein a transparent resin film layer is provided between the substrate and the heat-adhesive layer.   5. A colored layer having a thickness of 0.1 to 20 μm is further provided between the base material and the thermal adhesive layer or on the surface of the base material opposite to the thermal adhesive layer. The laminated sheet for carbon fiber reinforced plastics according to any one of the above.   One or more layers of a prepreg formed by impregnating a carbon fiber with a matrix resin are disposed, and the laminated sheet for carbon fiber reinforced plastic according to any one of claims 1 to 5 is disposed on the prepreg, the thermal adhesive layer side being the prepreg side. A method for producing a laminated composite material, wherein the laminated composite material is integrally molded after being laminated so as to face.   The method for producing a laminated composite material according to claim 6, wherein the integral molding is performed by heat and pressure molding. A laminated composite material comprising a carbon fiber reinforced plastic layer, a thermal adhesive layer having a softening point of 60 ° C. or lower, and a substrate in this order, wherein the thermal adhesive layer has a thickness of 0.1 to 20 μm. The laminated composite material according to claim 8, wherein a peel strength between the carbon fiber reinforced plastic layer and the substrate is 10 kgf / cm ² or more.