JP2018062119A - Carbon fiber-reinforced plastic laminate and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fiber-reinforced plastic laminate having excellent heat resistance without causing production problems.SOLUTION: The fiber-reinforced plastic laminate is provided that is a laminate having at least a two-layer structure, and has the following layer A and the following layer B, a softening point of the layer B being higher than that of the layer A and a softening point of the layer B being 230°C or higher and 300°C or lower. The layer A: fiber-reinforced plastic including a reinforcing fiber and a thermoplastic resin, an average fiber length of the reinforcing fiber being 10 mm or more. The layer B: reinforcing plastic including a thermoplastic resin, or a filler-containing material and a thermoplastic resin.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fiber-reinforced plastic laminate having heat resistance and a method for producing the same.

  In various fields such as aircraft members, automobile members, wind turbine members for wind power generation, and sports equipment, structural materials formed by stamping molding sheet-like fiber reinforced plastics are widely used. The fiber reinforced plastic is formed, for example, by stacking and integrating a plurality of prepreg base materials in which a reinforced fiber is impregnated with a thermoplastic resin.

  As a prepreg base material, for example, a sheet in which continuous reinforcing fibers having a long fiber length are aligned in one direction and impregnated with a thermoplastic resin is known. With a fiber reinforced plastic formed with a prepreg base material using such continuous long reinforcing fibers, a structural material having excellent mechanical properties can be produced.

  However, since the fiber reinforced plastic is a continuous reinforcing fiber, the fluidity at the time of shaping is low, and it is difficult to form into a complicated shape such as a three-dimensional shape. Therefore, when using this fiber reinforced plastic, the structural material to manufacture is mainly limited to the thing close | similar to a planar shape.

  When manufacturing a structural material by shaping a fiber reinforced plastic into a complicated shape such as a three-dimensional shape, a relatively short reinforcing fiber generally having a fiber length of 100 mm or less is required to ensure fluidity during shaping. Is used. However, when the fiber length of the reinforcing fiber is shortened, the mechanical properties of the structural material after shaping tend to be lowered. Therefore, a prepreg base material has been proposed in which a structural material having high mechanical properties is obtained while using reinforcing fibers having a short fiber length (Patent Document 1).

  When such a thermoplastic fiber reinforced plastic is used for a member exposed to a high temperature for a certain period of time, such as a coating process of an automobile member, a matrix resin having high heat resistance is used. For example, Patent Document 2 discloses a thermoplastic fiber reinforced plastic having heat resistance of coating by using a high heat resistant resin as a matrix.

International Publication No. 2012/140793 JP 2014-95034 A

  However, in order to use a highly heat-resistant matrix resin in order to improve the heat resistance of the fiber reinforced plastic, it is necessary to set a high temperature for producing the prepreg base material. It is generally difficult to impregnate the resin in the reinforcing fiber, and when a higher temperature is required, not only the heating equipment cost is increased, but the resin is easily decomposed due to the high temperature, Conversely, when the temperature rise is suppressed to suppress decomposition, impregnation failure occurs due to insufficient heating.

  An object of this invention is to provide the thermoplastic fiber reinforced plastic which has heat resistance, without producing the problem at the time of manufacture of said prepreg base material.

  As a result of intensive studies to solve the above problems, the present inventors have completed the present invention. That is, the gist of the present invention resides in the following [1] to [9].

[1] A laminate having at least a two-layer structure, comprising the following A layer and the following B layer, the softening point of the B layer being higher than that of the A layer, and the softening point of the B layer being 230 ° C. or higher and 300 ° C. A fiber reinforced plastic laminate which is the following.
Layer A: a fiber-reinforced plastic containing reinforcing fibers and a thermoplastic resin, wherein the average fiber length of the reinforcing fibers is 10 mm or more.
B layer: a thermoplastic resin, or a reinforced plastic containing a filler-containing material and a thermoplastic resin.
Softening point: When the thermoplastic resin constituting the layer is a crystalline resin, the melting point of the thermoplastic resin is the softening point of the layer, and when the thermoplastic resin constituting the layer is an amorphous resin, The glass transition point of the thermoplastic resin is the softening point of the layer.

[2] The fiber-reinforced plastic laminate according to the above [1], wherein the ratio of the thickness of the B layer is 0.5 or more and 0.9 or less with respect to the total thickness of the fiber-reinforced plastic laminate.
[3] The fiber-reinforced plastic laminate according to the above [1] or [2], wherein the fiber volume content of the reinforcing fibers in the A layer is 10 to 60% by volume.
[4] The fiber-reinforced plastic laminate according to any one of [1] to [3], wherein the average fiber length of the reinforcing fibers in the A layer is 10 to 50 mm, and the fibers are randomly oriented.
[5] The fiber-reinforced plastic laminate according to any one of [1] to [3], wherein the A layer is a laminate of a plurality of unidirectional continuous fiber prepregs.

[6] The fiber-reinforced plastic laminate according to any one of the above [1] to [5], wherein the filler of the B layer is a fiber having an average fiber length of 10 mm or less.
[7] The laminate according to any one of the above [1] to [6], which is a laminate having at least a three-layer structure, having A layers on both surface layers, and having the following B layers between both surface layers. Fiber reinforced plastic laminate.
[8] The method for producing a fiber-reinforced plastic laminate according to any one of [1] to [7], wherein the A layer and the B layer are integrated by press molding.
[9] The method for producing a fiber-reinforced plastic laminate according to any one of [1] to [7], wherein the A layer and the B layer are integrated by injection molding.

  It is possible to provide a fiber-reinforced plastic laminate having excellent heat resistance without causing problems during production such as thermal decomposition and impregnation failure.

It is the perspective view which showed a mode that a material was pressurized with a pair of press roll. It is the schematic diagram which showed an example of the double belt type heating pressurization noble.

  The fiber reinforced plastic laminate of the present invention is a laminate having at least a two-layer structure, and includes the following A layer and the following B layer, the softening point of the B layer being higher than that of the A layer, and the softening point of the B layer. Is a fiber reinforced plastic laminate having a temperature of 230 ° C. or higher and 300 ° C. or lower.

  When the softening point of the B layer is higher than that of the A layer, it is possible to obtain a fiber reinforced fiber reinforced plastic laminate having heat resistance at low cost while maintaining productivity.

Moreover, in order to endure the baking temperature at the time of coating after molding, the softening point is preferably 230 ° C. or higher, and the softening point is preferably 300 ° C. or lower in order to maintain excellent molding processability. Further, the softening point is preferably 230 ° C. or higher and 280 ° C. or lower.
<A layer>
A fiber reinforced plastic including reinforced fibers and a thermoplastic resin, wherein the average fiber length of the reinforced fibers is 10 mm or more.
<B layer>
It is a reinforced plastic containing a thermoplastic resin or a filler-containing material and a thermoplastic resin.

  In the present invention, the softening point of the layer means that when the thermoplastic resin constituting the layer is a crystalline resin, the melting point of the thermoplastic resin is the softening point of the layer, and the thermoplastic resin constituting the layer is In the case of an amorphous resin, the glass transition point of the thermoplastic resin is the softening point of the layer.

  The fiber reinforced plastic laminate of the present invention may have any layer structure of two or more layers, but preferably has a layer structure of three or more layers from the viewpoint of strength. Moreover, when it has a layer structure of three or more layers, it is preferable from a viewpoint of intensity | strength to have A layer in both surface layers, and to have B layer between the said both surfaces. Moreover, it is preferable that the ratio of the thickness of B layer is 0.5 or more and 0.9 or less with respect to the total thickness of a fiber reinforced plastic laminated body from a relation of strength or heat resistance.

(Reinforced fiber)
The reinforcing fibers used in the A layer are not particularly limited, and for example, reinforcing fibers having inorganic fibers, organic fibers, metal fibers, or a hybrid structure in which these are combined can be used. Examples of the inorganic fiber include carbon fiber, graphite fiber, silicon carbide fiber, alumina fiber, tungsten carbide fiber, boron fiber, and glass fiber. Examples of the organic fibers include aramid fibers, high density polyethylene fibers, other general nylon fibers, and polyester fibers. Examples of metal fibers include fibers such as stainless steel and iron, and carbon fibers coated with metal may be used. Among these, carbon fibers are preferable in view of mechanical properties such as strength of the structural material that is the final molded product.

  The carbon fiber is not particularly limited, and examples thereof include polyacrylonitrile (PAN) -based carbon fiber and PICH-based carbon fiber. A preferred carbon fiber is a carbon fiber having a strand tensile strength measured in accordance with JIS R7601 (1986) of 1.0 GPa or more and 9.0 GPa or less and a strand tensile elastic modulus of 150 GPa or more and 1000 GPa or less. More preferred carbon fibers are carbon fibers having a strand tensile strength of 1.5 GPa or more and 9.0 GPa or less measured according to JIS R7601 (1986) and a strand tensile modulus of 200 GPa or more and 1000 GPa or less.

  The average fiber length of the reinforcing fibers used in the A layer is preferably 10 mm or more. When used for stamping molding, 10 to 100 mm is preferable, 10 to 50 mm is more preferable, and 20 to 50 mm is particularly preferable. In general, the longer the reinforcing fiber, the more structural material excellent in mechanical properties can be obtained. However, the fluidity is lowered particularly during stamping molding, so that it becomes difficult to obtain a structural material having a complicated three-dimensional shape. When the average fiber length of the reinforcing fibers is not more than the upper limit value, excellent fluidity can be obtained at the time of shaping, and the reinforcing fibers and the matrix resin can easily flow. Therefore, it is easy to obtain a complicated three-dimensional structural material such as a rib or a boss. Moreover, if the average fiber length of the reinforcing fibers is not less than the lower limit value, a structural material having excellent mechanical properties can be produced.

The average fiber length of the reinforcing fiber in the fiber reinforced plastic can be measured by the following method. The matrix resin in the fiber reinforced plastic is burned off, and only the reinforcing fiber is taken out, and the fiber length of the reinforcing fiber is measured with a caliper or the like. The measurement is performed on 100 randomly selected reinforcing fibers, and the average fiber length is calculated as the mass average of them.
1-50 micrometers is preferable and, as for the average fiber diameter of a reinforced fiber, 5-20 micrometers is more preferable.

(Fiber volume content of reinforcing fibers in layer A)
10-60 volume% is preferable, as for the fiber volume content (Vf) of the reinforced fiber in the fiber reinforced plastics of this invention, 15-55 volume% is more preferable, and 20-50 volume% is further more preferable. If the Vf of the reinforcing fiber is not more than the upper limit value, the interface strength is not easily lowered due to a decrease in toughness, and the fluidity at the time of molding is hardly lowered. If Vf of the reinforcing fiber is equal to or higher than the lower limit value, mechanical properties required as a fiber reinforced plastic are easily obtained.

  The Vf value of the fiber reinforced plastic means the ratio of the reinforced fiber to the total volume of the reinforced fiber, the matrix resin, and other components such as additives excluding voids (gas) in the fiber reinforced plastic. Since the Vf value measured based on JIS K7075 varies depending on the amount of voids present in the fiber reinforced plastic, the present invention employs a fiber volume content that does not depend on the amount of voids present.

(Matrix resin for layer A)
The matrix resin used for the A layer may be used alone or in combination of two or more. As the matrix resin, a thermoplastic resin is preferable. Since a thermoplastic resin generally has a higher toughness value than a thermosetting resin, it is easy to obtain a structural material having excellent strength, particularly impact resistance, by using a thermoplastic resin as a matrix resin. In addition, the shape of the thermoplastic resin is determined by cooling and solidification without chemical reaction. Therefore, when a thermoplastic resin is used, molding can be performed in a short time, and the productivity of fiber reinforced plastic and structural material is excellent.

  The thermoplastic resin is not particularly limited, and polyamide resin (nylon 6, nylon 66, nylon 12, nylon MXD6, etc.), polyolefin resin (low density polyethylene, high density polyethylene, polypropylene, etc.), modified polyolefin resin (modified polypropylene resin) Etc.), polyester resin (polyethylene terephthalate, polybutylene terephthalate, etc.), polycarbonate resin, polyamideimide resin, polyphenylene oxide resin, polysulfone resin, polyethersulfone resin, polyetheretherketone resin, polyetherimide resin, polystyrene resin, ABS resin , Polyphenylene sulfide resin, liquid crystal polyester resin, copolymer of acrylonitrile and styrene, copolymer of nylon 6 and nylon 66, and the like. . Examples of the modified polyolefin resin include a resin obtained by modifying a polyolefin resin with an acid such as maleic acid. A thermoplastic resin may be used individually by 1 type, and may use 2 or more types together.

  The thermoplastic resin used for the A layer is a polyolefin resin, a modified polypropylene resin, a polyamide resin, a polyester from the viewpoint of the balance between the adhesion to the reinforcing fiber, the impregnation into the reinforcing fiber, and the raw material cost of the thermoplastic resin. It is preferable to include at least one selected from the group consisting of a resin and a polycarbonate resin.

(A layer)
Specific examples of the A layer include a random material in which the average fiber length of the reinforcing fibers in the A layer is 10 to 50 mm and the fibers are randomly oriented, a laminate of a plurality of unidirectional continuous fiber prepregs, and the like. It is done.

(B layer thermoplastic resin)
The thermoplastic resin used for the B layer is preferably superior in heat resistance to the A layer. In the case of a crystalline resin, the softening point is preferably 230 ° C. or higher in order to withstand the baking temperature during coating, and the softening point is preferably 300 ° C. or lower in order to maintain excellent moldability. Further, the softening point is preferably 230 ° C. or higher and 280 ° C. or lower. The thermoplastic resin having such a softening point preferably includes at least one selected from the group consisting of polyamide resin, polyester resin, and polyphenylene sulfide resin.

(Filler contained in layer B)
The layer B may not contain a filler, but may contain a filler from the viewpoint of strength and heat resistance.
Examples of the filler contained in the B layer include glass fiber and carbon fiber. From the viewpoint of easy production, the filler contained in the B layer is preferably fibrous with an average fiber length of 10 mm or less, and is fibrous with an average fiber length of 0.01 to 5.0 mm. It is more preferable.

(Other ingredients)
In the B layer of the present invention, a flame retardant, a weather resistance improver, an antioxidant, a heat stabilizer, an ultraviolet absorber, a plasticizer, a lubricant, a colorant, a compatibilizer depending on the required characteristics of the target structural material In addition, additives such as non-fibrous fillers, conductive fillers, mold release agents, and surfactants may be blended. In addition, these may be mix | blended with A layer.

(Method for producing unidirectionally oriented fiber reinforced plastic)
As a manufacturing method of the unidirectionally oriented fiber reinforced plastic of the present invention, a method having the following steps (i) to (iii) is preferable.
Step (i): A step of opening the reinforcing fibers aligned in one direction to form a sheet-like reinforcing fiber bundle having a uniform basis weight.
Step (ii): A step of sandwiching the sheet-like reinforcing fiber bundle from both sides with a film-like matrix resin and impregnating the matrix resin through a heating and pressing roll.
Step (iii): A step of obtaining a unidirectionally oriented fiber reinforced plastic by cooling and solidifying the fiber reinforced bundle impregnated with the matrix resin.

(Production method of randomly oriented fiber reinforced plastic)
As a method for producing the randomly oriented fiber-reinforced plastic of the present invention, a method having the following steps (iv) to (vi) is preferable.
Step (iv): A step of obtaining a material including a prepreg base material in which cuts are formed so as to intersect the fiber axis of the unidirectionally oriented fiber reinforced plastic obtained in the steps (i) to (iii).
Step (v): Using a pressurizing device that presses substantially uniformly in a direction orthogonal to the traveling direction of the material, the direction of the fiber axis of the reinforcing fiber intersects the traveling direction, and the material is unidirectional The process of pressurizing in the state heated to the temperature T more than a glass transition temperature, when not having melting | fusing point or more of the said matrix resin, making it run.
Step (vi): A step of cooling the material pressed by the pressing device to obtain a randomly oriented fiber reinforced plastic.

(Manufacturing method of fiber reinforced plastic laminate)
A fiber reinforced plastic laminate is obtained by laminating the fiber reinforced plastic (A layer) and heat-resistant resin (B layer) obtained as described above, and the production method is preferably any of the following methods. In any case, the fiber reinforced plastic of the A layer may be used alone or may be used by being laminated so as to have an appropriate thickness.
(1) A method in which a heat-resistant resin (B layer) is processed into a sheet shape in advance and laminated with the fiber reinforced plastic (A layer) by a hot press.
(2) A method of obtaining a laminate by charging the fiber reinforced plastic (A layer) into a mold and filling the remaining space with a heat resistant resin (B layer) by injection molding.
Examples of methods for evaluating the fiber reinforced plastic laminate include the following methods.

(Measurement method of softening point)
In the case of a crystalline resin, the softening point is synonymous with the melting point, and is the melting peak temperature (Tpm) described in JIS K7121. In the case of an amorphous resin, the softening point is synonymous with the glass transition temperature, and is defined as the intermediate point glass transition temperature (Tmg) described in JIS K7121.

(Measurement method of deflection temperature under load)
Among the methods described in JISK7191-2, a flat-wise test is used. The test piece size is 80 mm in length, 10 mm in width, and 4 mm in thickness. The temperature at which the load reaches 0.45 MPa as defined by the B method and the specified deflection amount is 0.34 mm is defined as the deflection temperature under load.

(Evaluation of heat resistance)
Those having a deflection temperature under load of 200 ° C. or higher are judged to be heat-resistant fiber-reinforced plastic laminates.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to the invention as described in an Example.
[Example 1]
(A layer)
Carbon fiber (product name: Pyrofil (registered trademark) TR-50S15L manufactured by Mitsubishi Rayon Co., Ltd.) is aligned in one direction to form a reinforcing fiber sheet having a basis weight of 72.0 g / m ^2, and both sides of the reinforcing fiber sheet Is sandwiched between films of polyamide 6 resin (manufactured by Ube Industries, product name: 1013B) having a basis weight of 45.6 g / m ² , and a fiber sheet is impregnated with a thermoplastic sheet through a calender roll heated to 280 ° C., A unidirectional fiber reinforced plastic having a fiber volume content (Vf) of 33% and a thickness of 0.12 mm was obtained. The obtained unidirectional fiber reinforced plastic was cut into a 300 mm square, and 8 layers were stacked in a pseudo isotropic manner ([0/45/90 / −45] s).

(B layer)
Next, 250 g of pellets of polyamide 66 resin (manufactured by DuPont, product name: Seidel 101F) are placed in a 300 mm square and 5.0 mm deep stamping mold and heated to form a compression molding machine (manufactured by Shinto Metal Industry, product name: SFA-50HH0), held at high temperature side press at 280 ° C. and hydraulic pressure instruction of 0 MPa for 7 minutes, then held at the same temperature for hydraulic pressure instruction of 2 MPa (press pressure 0.55 MPa) for 7 minutes, The mold was moved to a cooling press and held for 3 minutes at 80 ° C. and a hydraulic pressure instruction of 5 MPa (press pressure 1.38 MPa) to obtain a sheet-like molded product having a thickness of about 2 mm.

  The A layer and the B layer thus obtained were stacked in the order of A layer / B layer / A layer, placed in the mold, heated, and heated at 280 ° C. with a high temperature side press using the compression molding machine. Hold for 7 minutes under the condition of 0MPa, then hold at the same temperature for 7 minutes under the condition of hydraulic pressure indication 2MPa (press pressure 0.55MPa), then move the mold to the cooling press, 80 ℃, hydraulic pressure indication 5MPa (press pressure 1.38 MPa) for 3 minutes to obtain a fiber reinforced plastic laminate having a thickness of 4 mm.

[Evaluation results]
The softening temperature of the A layer was 220 ° C., the softening temperature of the B layer was 263 ° C., and the deflection temperature under load of the fiber reinforced plastic laminate in which the A layer and the B layer were laminated was sufficiently high at 200 ° C.

[Example 2]
(A layer)
The unidirectional fiber reinforced plastic obtained by the method described in Example 1 was cut into a rectangle of 300 mm (0 ° direction with respect to the fiber axis) × 900 mm (90 ° direction with respect to the fiber axis), and then a cutting plotter ( Rezac L-2500 cutting plotter) is used to reinforce the unidirectional fiber reinforced plastic so that the absolute value of the angle φ between the cut and the fiber axis of the reinforcing fiber is 45 ° and the fiber length L of the reinforcing fiber is 25 mm. A notch having a depth for cutting the fiber was made to obtain a notched unidirectional fiber-reinforced plastic. Four sheets of the prepreg base material with cuts were laminated so that the fiber axes of the reinforcing fibers were in the same direction to obtain a prepreg laminate. The direction of the fiber axis of the reinforcing fiber in the prepreg laminate with respect to the axial direction of the press roll is applied to the double belt type heating and pressing machine illustrated in FIG. 2 in which the upper and lower belts are driven at 1.0 m / min. Was added so that the angle θ formed by In the double belt type heating and pressurizing machine, the prepreg laminate is heated by a two-stage press roll having a roll temperature of 310 ° C. and a belt clearance of 300 μm immediately below the roll to melt the thermoplastic resin. did. After that, a 1.5 m cooling section provided with a one-stage hot water roll having a roll temperature of 30 ° C. and a clearance between belts of 300 μm immediately below the roll was passed, and the thermoplastic resin was solidified to obtain a fiber reinforced plastic.

(B layer)
A sheet-like molded product having a thickness of 2 mm was obtained in the same manner as in the example.
The A layer and B layer thus obtained were laminated and heated and pressed in the same manner as in Example 1 to obtain a fiber reinforced plastic laminate having a thickness of 4 mm.

[Evaluation results]
The softening temperature of the A layer was 220 ° C., the softening temperature of the B layer was 263 ° C., and the deflection temperature under load of the fiber reinforced plastic laminate in which the A layer and the B layer were laminated was sufficiently high, 200 ° C.

[Comparative Example 1]
After obtaining A layer by the same method as Example 1, the sheet | seat of 2 mm thickness was created using the polyamide 6 resin (the Ube Industries, product name: 1013B) by the same method as Example 1. FIG. Next, lamination and heating press were performed in the same manner as in Example 1 to obtain a fiber reinforced plastic laminate having a thickness of 4 mm.
As a result, the softening temperature of the A layer was 220 ° C., the softening temperature of the B layer was 220 ° C., and the deflection temperature under load of the fiber reinforced plastic laminate in which the A layer and the B layer were laminated was 155 ° C., which was insufficient.

[Example 3]
A resin in which polycarbonate resin (product name: Iupilon H-4000, manufactured by Mitsubishi Engineering Co., Ltd.) and polybutylene terephthalate resin (product name: manufactured by Mitsubishi Engineering Corp., product name: NOVADURAN 5010R5) is mixed with the A layer film at a blend ratio of 80:20. Except for the use, the A and B layers were obtained in exactly the same manner as in Example 1, and then they were laminated and heated and pressed to obtain a 4 mm thick fiber reinforced plastic laminate.
As a result, the softening temperature of the A layer was 222 ° C., the softening temperature of the B layer was 263 ° C., and the deflection temperature under load of the fiber reinforced plastic laminate in which the A layer and the B layer were laminated was sufficiently high, 200 ° C.

[Comparative Example 2]
A resin in which polycarbonate resin (product name: Iupilon H-4000, manufactured by Mitsubishi Engineering Co., Ltd.) and polybutylene terephthalate resin (product name: manufactured by Mitsubishi Engineering Corp., product name: NOVADURAN 5010R5) is mixed with the A layer film at a blend ratio of 80:20. Except for the use, the A layer and the B layer were obtained in exactly the same manner as in Example 2, and then they were laminated and heated and pressed to obtain a 4 mm thick fiber reinforced plastic laminate.
As a result, the softening temperature of the A layer was 222 ° C., the softening temperature of the B layer was 220 ° C., and the deflection temperature under load of the fiber reinforced plastic laminate in which the A layer and the B layer were laminated was 155 ° C., which was insufficient.

[Example 4]
Carbon fiber (product name: Pyrofil (registered trademark) TR-50S15L manufactured by Mitsubishi Rayon Co., Ltd.) is aligned in one direction to form a reinforcing fiber sheet having a basis weight of 72.0 g / m ^2, and both sides of the reinforcing fiber sheet Is impregnated with a film made of a modified polypropylene resin (product name: Modic P958, manufactured by Mitsubishi Chemical Corporation) with a basis weight of 36.4 g / m ² , and the fiber sheet is impregnated with a thermoplastic sheet through a calender roll heated to 250 ° C. A fiber volume content (Vf) of 33% and a thickness of 0.12 mm were obtained. The obtained unidirectional fiber-reinforced plastic was cut into a 300 mm square, and four layers were stacked in a pseudo isotropic manner ([0/45/90 / -45]) (A layer).

Next, the same method as in Example 1 375 g of polyamide 66 pellets were hot-pressed to obtain a B layer having a thickness of 3 mm, and then layered in the order of A layer / B layer / A layer in the same manner as in Example 1. Then, a hot press was performed to obtain a fiber reinforced plastic laminate having a thickness of 4 mm.
As a result, the softening temperature of the A layer was 165 ° C., the softening temperature of the B layer was 263 ° C., and the deflection temperature under load of the fiber reinforced plastic laminate in which the A layer and the B layer were laminated was 200 ° C.

[Comparative Example 3]
A fiber-reinforced plastic laminate having a thickness of 4 mm was obtained in the same manner as in Example 4 except that polyamide 6 was used for layer B.
As a result, the softening temperature of the A layer was 165 ° C., the softening temperature of the B layer was 220 ° C., and the deflection temperature under load of the fiber reinforced plastic laminate in which the A layer and the B layer were laminated was 155 ° C., which was insufficient.

[Example 5]
After obtaining a unidirectionally oriented fiber reinforced plastic in the same manner as in Example 1, heat pressing was performed to obtain a 1 mm thick pseudo-isotropic laminated fiber reinforced plastic (layer A). Thereafter, the fiber reinforced plastic was cut into 100 mm × 100 mm, and inserted into an injection mold having a cavity size of 100 mm × 100 mm and a thickness of 4 mm. Thereafter, PPS resin (product name: Torelina A504X90, manufactured by Toray Industries, Inc.) was injection molded at a cylinder temperature of 330 ° C. and a mold temperature of 110 ° C. so that the resin was filled on one side of the inserted A layer.
As a result, the softening temperature of the A layer was 220 ° C., the softening temperature of the B layer was 278 ° C., and the deflection temperature under load of the fiber reinforced plastic laminate in which the A layer and the B layer were laminated was 250 ° C. or higher.

[Comparative Example 4]
A fiber reinforced plastic laminate is obtained in the same manner as in Example 5 except that the injection resin of layer B is set to PEEK resin (product name: 450G manufactured by VICTREX), cylinder temperature 380 ° C., mold temperature 150 ° C. It was. However, since the PEEK resin was at a high temperature during injection molding, the A layer existing at the interface was decomposed and evaluation could not be performed.

[Comparative Example 5]
(A layer)
Carbon fiber (product name: Pyrofil (registered trademark) TR-50S15L manufactured by Mitsubishi Rayon Co., Ltd.) is aligned in one direction to form a reinforcing fiber sheet having a basis weight of 72.0 g / m ^2, and both sides of the reinforcing fiber sheet Is sandwiched between films of polyamide 66 resin (manufactured by DuPont, product name: Seidel 101F) with a basis weight of 45.6 g / m ² and passed through a calender roll heated to 280 ° C., but the resin is sufficiently contained in the fiber bundle. Could not be impregnated.

DESCRIPTION OF SYMBOLS 1 Double belt type heat press machine 10 Press roll 12 Belt 14 IR heater 16 Hot water roll 18 Winding roll 20 Drive roll 22 Driven roll 24 Guide roll 100 Unidirectional fiber reinforced plastic 110 Reinforced fiber 120 Fiber reinforced plastic (A layer)

Claims (9)

A laminate having at least a two-layer structure, comprising the following A layer and B layer, the softening point of the B layer being higher than that of the A layer, and the softening point of the B layer being 230 ° C. or higher and 300 ° C. or lower. , Fiber reinforced plastic laminate.
Layer A: a fiber-reinforced plastic containing reinforcing fibers and a thermoplastic resin, wherein the average fiber length of the reinforcing fibers is 10 mm or more.
B layer: a thermoplastic resin, or a reinforced plastic containing a filler-containing material and a thermoplastic resin.
Softening point: When the thermoplastic resin constituting the layer is a crystalline resin, the melting point of the thermoplastic resin is the softening point of the layer, and when the thermoplastic resin constituting the layer is an amorphous resin, The glass transition point of the thermoplastic resin is the softening point of the layer.   The fiber-reinforced plastic laminate according to claim 1, wherein the ratio of the thickness of the B layer is 0.5 or more and 0.9 or less with respect to the total thickness of the fiber-reinforced plastic laminate.   The fiber reinforced plastic laminate according to claim 1 or 2, wherein the fiber volume content of the reinforcing fibers in the A layer is 10 to 60% by volume.   The fiber reinforced plastic laminate according to any one of claims 1 to 3, wherein the average fiber length of the reinforcing fibers in the A layer is 10 to 50 mm, and the fibers are randomly oriented.   The fiber-reinforced plastic laminate according to any one of claims 1 to 3, wherein the A layer is a laminate of a plurality of unidirectional continuous fiber prepregs.   The fiber-reinforced plastic laminate according to any one of claims 1 to 5, wherein the filler of the B layer is a fiber having an average fiber length of 10 mm or less.   It is a laminated body which has at least 3 layer structure, Comprising: A fiber reinforced plastics laminated body in any one of Claims 1-6 which has A layer in both surface layers, and has the following B layer between both surface layers. .   The method for producing a fiber-reinforced plastic laminate according to any one of claims 1 to 7, wherein the A layer and the B layer are integrated by press molding.   The method for producing a fiber-reinforced plastic laminate according to any one of claims 1 to 7, wherein the A layer and the B layer are integrated by injection molding.