JP2019177669A - Thermoplastic resin laminate - Google Patents

Abstract

An object of the present invention is to provide a thermoplastic resin laminate excellent in mechanical strength and impact resistance. A core layer containing a thermoplastic resin, an outermost layer containing carbon fibers, and a metal sheet layer having an elongation of 10% or more during a tensile test between the core layer and the outermost layer. Is a thermoplastic resin laminate having the following formula: [Selection diagram] None

Description

  The present invention relates to a laminate in which a thermoplastic resin and carbon fiber are combined.

  In recent years, there has been a growing need for molded products that are lightweight, high-strength, and excellent in impact resistance, such as casings for large electrical appliances, interior materials and exterior materials for automobiles and railways. In particular, such molded products are also required to emphasize productivity while maintaining performance such as mechanical strength. That is, a material having a good balance between mechanical strength and impact resistance is required. Based on such a background, a material in which a thermoplastic resin and inorganic fibers are combined has been proposed.

  For example, Patent Document 1 discloses a core layer made of a synthetic resin foam, an outermost layer made of an aluminum sheet, and a reinforcing layer made of glass fiber with an adhesive layer between the core layer and the outermost layer. An aluminum laminated plate provided with the above is disclosed.

  Patent Document 2 discloses a polycarbonate resin laminate having a polycarbonate resin substrate and a polycarbonate composite layer containing a filler laminated on the substrate.

JP 2001-301092 A JP 2009-96048 A

  However, in the aluminum laminate disclosed in Patent Document 1, the core layer made of a synthetic resin foam has a foam structure, and the reinforcing fiber-containing resin layer is provided with pores, so that it is impact resistant and lightweight. However, mechanical strength, particularly bending elastic modulus, is weakened by pores present in the reinforcing fiber-containing resin layer.

  In the polycarbonate resin laminate disclosed in Patent Document 2, a laminate having an excellent balance with impact resistance in the vicinity of 5 GPa is disclosed, but when a flexural modulus greater than 5 GPa is expressed. There is no mention of the relationship with the impact resistance of the.

  An object of the present invention is to provide a thermoplastic resin laminate excellent in mechanical strength and impact resistance.

  As a result of intensive studies in view of the above circumstances, the present inventors have found that the following invention can solve the above problems, and have completed the present invention.

That is, the gist of the present invention is as follows.
[1] A core layer including a thermoplastic resin, an outermost layer including carbon fibers, and a metal sheet layer having an elongation of 10% or more during a tensile test between the core layer and the outermost layer. A thermoplastic resin laminate.
[2] The thermoplastic resin laminate according to [1], wherein the thickness ratio of the metal sheet layer to the laminate is 2 to 30%.
[3] The thermoplastic resin laminate according to [1] or [2], wherein the carbon fiber is a polyacrylonitrile-based carbon fiber.
[4] The thermoplastic resin laminate according to any one of [1] to [3], wherein the metal sheet layer is made of aluminum having a purity of 99.99% or more.
[5] The thermoplastic resin laminate according to any one of [1] to [4], wherein the core layer further includes glass fibers.

  ADVANTAGE OF THE INVENTION According to this invention, the thermoplastic resin laminated body excellent in mechanical strength and impact resistance can be provided.

  Hereinafter, embodiments of the thermoplastic resin laminate of the present invention will be described in detail.

  It should be noted that the upper and lower limits of the numerical range in the present invention are those of the present invention as long as they have the same operational effects as those in the numerical range even if they are slightly outside the numerical range characterized by the present invention. It is included in the equivalent range. The main component in the present invention is a component contained in the largest amount, and is usually a component containing 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more. .

<Thermoplastic resin laminate>
The thermoplastic resin laminate of the present invention has a core layer containing a thermoplastic resin, an outermost layer containing carbon fibers, and an elongation of 10% or more during a tensile test between the core layer and the outermost layer. And a metal sheet layer.
Hereinafter, the “thermoplastic resin laminate of the present invention” may be referred to as “the present laminate”.
Conventionally, a synthetic resin foam as disclosed in Patent Document 1 is used as a core layer as a laminated body that is lightweight and retains high rigidity and is resistant to external impact, and a fiber reinforced plastic is used as the core layer. A laminate in which aluminum sheets were laminated was used. However, as described above, in this configuration, although the impact resistance and the light weight are ensured, the mechanical strength, particularly the bending elastic modulus, is weak due to the pores present in the reinforcing fiber-containing resin layer.
In order to express the flexural modulus, a means of stacking high-rigidity materials is used. On the other hand, from the viewpoint of impact resistance, the higher-rigidity material is more likely to break, and the material is damaged by cracks. Cheap. In other words, there is a contradiction in high rigidity and impact resistance.

On the other hand, this laminated body is excellent in both mechanical strength and impact resistance. The reason for this is not clear, but a layer containing carbon fiber having a high elastic modulus is disposed on the outermost layer of the laminate, and a metal sheet layer having tensile elongation characteristics is disposed between the core layer and the outermost layer. It is considered that the impact resistance is also exhibited without hindering the high rigidity developed by the carbon fiber-containing layer. In addition, the laminate is less likely to be deformed when subjected to an impact.
Hereinafter, the core layer, the outermost and back layers, and the metal sheet of the laminate will be described.

[Core layer]
A core layer is a layer which exists as an intermediate | middle layer of this laminated body, and contains a thermoplastic resin.
When the core layer contains the thermoplastic resin, the laminate having excellent moldability and heat resistance can be obtained.
The core layer may further contain glass fibers in order to further increase the rigidity of the laminate.

(Thermoplastic resin)
The thermoplastic resin is not particularly limited, and examples thereof include polyolefin resins, polycarbonate resins, polyamide resins, and polyester resins. These resins may be used alone or in combination of two or more.
Among these resins, by using a polyolefin-based resin, it is possible to obtain the present laminate having excellent moldability and light weight. As will be described later, among polyolefin resins, a polypropylene resin is particularly preferable.

  Hereinafter, the polyolefin resin, the polycarbonate resin, the polyamide resin, and the polyester resin will be described.

(1) Polyolefin resin Examples of the polyolefin resin include homopolymers, random copolymers, block copolymers, and the like of α-olefins such as propylene and ethylene. Specifically, polyethylene resins, polypropylene resins, and polybutadienes. Based resins and the like. Polypropylene resins and polyethylene resins are preferred from the viewpoint of moldability and light weight of the thermoplastic resin laminate, and polypropylene resins are particularly preferred from the viewpoint of mechanical properties and heat resistance. The polyolefin resin may be used by mixing a plurality of polyolefin resins.

The polypropylene resin may be a homopolymer of propylene, or a comonomer component such as ethylene or butene may be copolymerized with propylene. Moreover, when a core layer contains glass fiber, a modified polymer can also be preferably used from the point of adhesiveness with reinforcing fibers, such as glass fiber, and the familiarity.
Examples of the comonomer other than ethylene and butene include α-olefins having 5 to 20 carbon atoms. Examples of the α-olefin having 5 to 20 carbon atoms include 1-hexene and 1-octene. One or more α-olefins copolymerized with propylene may be used.

  The polyethylene resin may be a homopolymer of ethylene or may be copolymerized with a comonomer component such as ethylene and α-olefin.

  The melt mass flow rate (MFR), which is an index of the molecular weight of the polyolefin resin, is not particularly limited, but it is necessary that kneading, laminating and the like be performed stably.

The MFR (230 ° C., 21.2 N load) of the polypropylene resin is preferably 1 g / 10 min or more and 100 g / 10 min or less, more preferably 5 g / 10 min or more, or 75 g / 10 min or less. Preferably it is 10 g / 10 min or more, or 50 g / 10 min or less.
The MFR (190 ° C., 21.2 N load) of the polyethylene resin is preferably 1 g / 10 min or more and 50 g / 10 min or less, more preferably 2 g / 10 min or more, or 35 g / 10 min or less, more preferably It is 5 g / 10 min or more or 25 g / 10 min or less.

  When the MFR of the polypropylene resin and the polyethylene resin is equal to or more than the above lower limit, the followability to the mold at the time of press molding becomes easy. On the other hand, by being below the above upper limit, there is no possibility of flowing out of the mold due to pressurization during press molding, and resin impregnation between carbon fibers and glass fibers becomes easy.

  Here, MFR is a value measured in accordance with JIS K7210-1999 “Testing methods for melt flow rate (MFR) and melt volume flow rate (MVR) of plastic-thermoplastic plastic”.

  The method for producing the polyolefin resin is not particularly limited, and a known polymerization method, for example, an ion polymerization method using a radical polymerization method, a Ziegler catalyst, a metallocene catalyst, a Phillips catalyst or the like can be employed.

(2) Polycarbonate resin The polycarbonate resin that can be used in the present invention may be either a homopolymer or a copolymer. Further, the polycarbonate-based resin may have a branched structure, a linear structure, or a mixture of a branched structure and a linear structure. A plurality of polycarbonate resins may be mixed and used.
The so-called polyester carbonate resin (resin having both ester bond and carbonate bond in the molecular chain) is also included in the polycarbonate resin.

Representative examples of the dihydric alcohol (diol) constituting the polycarbonate resin include bisphenols. In particular, 2,2-bis (4-hydroxyphenyl) propane, that is, bisphenol A is preferably used.
A diol other than bisphenol A may be used alone or in combination with a plurality of diols, and any of an aromatic diol, an aliphatic diol, and an alicyclic diol may be used.

  The melt mass flow rate (MFR) of the polycarbonate resin is measured in accordance with JIS K7210 (1999) under the conditions of a temperature of 300 ° C. and a load of 1.2 kgf, and is preferably 1 g / 10 min or more and 50 g / 10 min or less. / 10 min or more or 35 g / 10 min or less is more preferable, and 3 g / 10 min or more or 30 g / 10 min or less is particularly preferable. When the MFR is 1 g / 10 min or more, followability to the mold during press molding becomes easy. On the other hand, when it is 40 g / 10 min or less, there is no fear of flowing out of the mold due to pressurization during press molding, and resin impregnation between carbon fibers and glass fibers becomes easy.

  The production method of the polycarbonate-based resin is not particularly limited, and a known polymerization method such as a phosgene method, a transesterification method, a pyridine method, and the like can be given.

(3) Polyamide-based resin The polyamide-based resin that can be used in the present invention is preferably an aliphatic polyamide, which is obtained by ring-opening homopolymerization of ω-amino acids, or obtained by ring-opening copolymerization of different ω-amino acids. And those obtained by copolymerization of diamine and dicarboxylic acid. In addition, aromatic polyamide and aromatic-aliphatic polyamide can also be used.

  The melt mass flow rate (MFR) of the polyamide-based resin is measured under the conditions of a temperature of 230 ° C. and a load of 2.16 kgf in accordance with JIS K7210 (1999) in the case of an aliphatic polyamide, 0.1 g / 10 min or more, 60 g / 10 min. Or less, more preferably 0.5 g / 10 min or more, or 30 g / 10 min or less, and particularly preferably 1 g / 10 min or more, or 20 g / 10 min or less. When the MFR is 0.1 g / 10 min or more, impregnation of the mold during press molding becomes easy. On the other hand, when it is 60 g / 10 min or less, there is no risk of flowing out of the mold due to pressurization during press molding, and resin impregnation between carbon fibers and glass fibers becomes easy.

  The production method of the polyamide-based resin is not particularly limited, and a known polymerization method can be employed.

(4) Polyester resin Examples of the polyester resin that can be used in the present invention include aliphatic polyester resins and aromatic polyester resins. Among these, from the viewpoint of heat resistance and moldability of the thermoplastic resin laminate, aromatic polyester resins are preferable, and specific examples include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and polytrimethylene terephthalate.

  The melt mass flow rate (MFR) of the polyester resin is measured in accordance with JIS K7210 (1999) under the conditions of a temperature of 230 ° C. and a load of 2.16 kgf, and is preferably 0.1 g / 10 min or more and 60 g / 10 min or less. 0.5 g / 10 min or more, or 30 g / 10 min or less is more preferable, and 1 g / 10 min or more or 20 g / 10 min or less is particularly preferable. When the MFR is 0.1 g / 10 min or more, impregnation of the mold during press molding becomes easy. On the other hand, when it is 60 g / 10 min or less, there is no risk of flowing out of the mold due to pressurization during press molding, and resin impregnation between carbon fibers and glass fibers becomes easy.

  The manufacturing method of a polyester-type resin is not specifically limited, A well-known polymerization method is employable.

The core layer is preferably made of a thermoplastic resin composition containing various additives in addition to the thermoplastic resin described above.
Specific examples of additives that the thermoplastic resin composition may include include colorants including pigments such as carbon black, flame retardants, weathering stabilizers, heat stabilizers, antistatic agents, melt viscosity improvers, crosslinkers, Examples thereof include a lubricant, a nucleating agent, a plasticizer, an anti-aging agent, an antioxidant, a light stabilizer, an ultraviolet absorber, a neutralizing agent, an antifogging agent, an antiblocking agent, and a slip agent.

(Glass fiber)
As described above, the core layer may further contain glass fibers in order to further increase the rigidity of the laminate, and the thermoplastic resin composition preferably contains glass fibers.
When the core layer contains glass fibers as reinforcing fibers, the mechanical strength and impact resistance of the thermoplastic resin laminate can be further increased.
Only one type of glass fiber may be used, or two or more types having different materials, average fiber length, fiber diameter, and the like may be used.

  Generally as a glass fiber, a commercially available thing can be used suitably. The fiber diameter of the glass fiber is preferably 8 to 20 μm, more preferably 10 to 15 μm, and the average fiber length of the glass fiber is preferably 20 to 200 mm, more preferably 25 to 200 mm. When the diameter of the glass fiber is 8 μm or more, the price is suppressed and the cost is excellent, and when it is 20 μm or less, the mechanical strength is excellent. From the viewpoint of mechanical strength and impact resistance, the glass fiber is preferably a mixture of glass fibers of various lengths. Moreover, it is preferable to use as a fiber bundle which contains 100-4,000 such single fibers in one fiber bundle.

  The breaking elongation of the glass fiber is preferably 2.0% or more, more preferably 2.5% or more, and further preferably 3.0% or more. When the breaking elongation of the glass fiber is 2.0% or more, the impact resistance of the laminate is easily set in a more practical range. Although there is no restriction | limiting in particular in the upper limit of the breaking elongation of glass fiber, Usually, the breaking elongation of glass fiber is 3-5% or less.

  The glass fiber that can be contained in the core layer preferably has a higher elongation at break than the carbon fibers used in the outermost and back layers. Specifically, the difference between the breaking elongation (%) of the glass fiber and the breaking elongation (%) of the carbon fiber is preferably about 1.0 to 5.0 (%). When the difference in elongation at break is within this range, the laminate can exhibit excellent mechanical strength and impact resistance.

  The core layer preferably contains glass fiber and thermoplastic resin, and the content of each component is 30 to 400 parts by weight, preferably 50 to 300 parts by weight of thermoplastic resin with respect to 100 parts by weight of glass fiber. Further, it is preferable to contain 60 to 200 parts by weight. Moreover, it is preferable that a core layer contains 30 weight% or more of glass fiber and a thermoplastic resin in total, and it is preferable to contain especially 30-100 weight%. When the thermoplastic resin content is in the above range, a laminate having excellent mechanical strength and excellent balance between mechanical strength and impact resistance is obtained.

From the viewpoint of impact resistance, the thickness of the core layer is preferably 1.5 mm or more, more preferably 2.0 mm or more, and further preferably 2.5 mm or more.
Further, the ratio of the thickness of the core layer to the laminate ([the thickness of the core layer / the total thickness of the laminate) × 100] is in the range of 60 to 90%. From the viewpoint of the balance between the properties and the mechanical strength of the thermoplastic resin laminate and the cost.

The core layer is produced by laminating one or a plurality of thermoplastic resin sheets made of the thermoplastic resin composition containing the above-described thermoplastic resin.
When the core layer further contains glass fiber, a glass fiber sheet made of glass fiber and a thermoplastic resin sheet may be laminated and used, or a thermoplastic resin sheet made of a thermoplastic resin composition containing glass fiber (A thermoplastic resin sheet containing glass fibers) may be used. When laminating a glass fiber sheet and a thermoplastic resin sheet, one or a plurality of sheets can be used for each sheet. When a plurality of sheets are used, glass fiber sheets and thermoplastic resin sheets may be alternately laminated, or may be laminated randomly, or a plurality of glass fiber sheets and a plurality of thermoplastic resins. You may overlap a sheet | seat. Also when using a glass fiber-containing thermoplastic resin sheet, one or a plurality of glass fiber-containing thermoplastic resin sheets can be used. A glass fiber sheet may be further laminated on the glass fiber-containing thermoplastic resin sheet, and a reinforcing fiber sheet other than the glass fiber may be further laminated as necessary.
Among the above, the core layer is preferably produced by using a single glass fiber-containing thermoplastic resin sheet or by laminating a plurality of sheets from the viewpoint of increasing the mechanical strength of the laminate.

  The glass fiber-containing thermoplastic resin sheet is preferably glass fiber paper or glass fiber mat. Here, both “glass fiber paper” and “glass fiber mat” are sheets in which fiber bundles are opened, dispersed, formed by a wet method, a dry method, or the like, and made into a flat film.

  Glass fiber paper and glass fiber mat are usually manufactured by either the dry nonwoven fabric method or the wet papermaking method, but those manufactured by the dry nonwoven fabric method from the viewpoint of better productivity and fiberglass opening. It is preferable to use it.

  The glass fiber-containing thermoplastic resin sheet may be a so-called prepreg in which glass fiber is impregnated with the above-described thermoplastic resin such as polyolefin resin. In general, “glass fiber mat” is distinguished from “glass fiber paper” in terms of thermoplastic resin content, thickness and the like. Usually, the glass fiber mat has a larger thermoplastic resin content and a larger thickness than the glass fiber paper.

The glass fiber-containing thermoplastic resin sheet preferably has a large basis weight (glass fiber amount and thermoplastic resin) from the viewpoint of mechanical strength and impact resistance of the laminate. Considering the balance between productivity and cost of the sheet itself, the basis weight (glass fiber amount) of the thermoplastic resin sheet is preferably 50 to 400 g / m ² , more preferably 50 to 350 g / m ² , and particularly preferably. Is 50 to 300 g / m ² . Moreover, it is preferable that the amount of thermoplastic resin of a glass fiber sheet shall be about 0 to 70 weight% with respect to carbon fiber.

  The thickness of the glass fiber-containing thermoplastic resin sheet is not particularly limited, and varies depending on whether the glass fiber-containing thermoplastic resin sheet is used as a single layer sheet or a laminated sheet of a plurality of glass fiber-containing thermoplastic resin sheets. However, it is usually about 100 to 5000 μm.

[Outermost layer]
The outermost layer is a layer mainly contributing to increase the rigidity of the laminate, and is a layer containing carbon fibers.
The carbon fiber may be any of pitch-based carbon fiber and polyacrylonitrile-based carbon fiber (PAN-based carbon fiber), and may be used in combination. However, the PAN-based fiber is less likely to break in the process of forming the reinforcing fiber mat. Carbon fiber is preferred. In addition, carbon fiber may be used individually by 1 type, and 2 or more types may be mixed and used for it.

From the viewpoint of the mechanical strength of the laminate, in particular, from the viewpoint of easily developing high rigidity in a bending test, carbon fibers having a low elongation at break and a high tensile elastic modulus may be disposed on the outermost layer of the laminate. preferable.
Therefore, as described above, it is preferable to use carbon fibers having a lower elongation at break than the glass fibers in the case where the core layer contains glass fibers as the outermost layer.

The fiber length of the carbon fiber is preferably 30 to 200 mm, more preferably 35 to 200 mm, still more preferably 40 to 200 mm, and still more preferably 40 to 100 mm. The proportion of carbon fibers having such a fiber length is preferably 25 to 100 parts by weight, particularly preferably 30 to 100 parts by weight, in 100 parts by weight of carbon fibers. When the fiber length of carbon fiber of 25 parts by weight or more out of 100 parts by weight of carbon fiber is 30 mm or more, the mechanical strength of the laminate is more excellent.
From the viewpoint of mechanical strength, the fiber length of carbon fiber is preferably as long as continuous fiber, but from the viewpoint of fiber defibration and dispersibility in the process of creating a nonwoven fabric containing carbon fiber by a dry method, carbon fiber fiber The length is usually 100 mm or less.

  When the carbon fiber has the above-described fiber length, the bending elastic modulus of the laminate can be maintained, and balance with impact resistance can be achieved.

  Here, the fiber length of the carbon fiber can be measured by the method described in the section of Examples described later.

  The breaking elongation of the carbon fiber is preferably 1.0% or more, more preferably 1.4% or more, and further preferably 1.5% or more. When the elongation at break of the carbon fiber is 1.0% or more, the impact resistance of the laminate is easily maintained within a practical range. Further, from the viewpoint of impact resistance, the larger the breaking elongation of the carbon fiber, the better. However, the breaking elongation of the carbon fiber described above is usually 2.5% or less.

The outermost layer may include only one type of the above carbon fibers, or may include two or more types of carbon fibers having different materials, fiber lengths, fiber diameters, and the like.
Moreover, the carbon fiber of the outermost layer and the carbon fiber of the outermost layer may be the same or different, but they are the same from the viewpoint of convenience of material procurement and suppression of warpage of the laminate. It is preferable that

In addition to the carbon fibers, the outermost and back layers may contain the above-described thermoplastic resin such as a polyolefin resin as a binder resin so that the carbon fibers are not easily dissociated. Moreover, the outermost surface back layer may contain the various additives which the thermoplastic resin composition which comprises a core layer may contain as needed.
When the outermost layer includes a thermoplastic resin, the content of the thermoplastic resin in the outermost layer is preferably 0 part by weight or more and 200 parts by weight or less, particularly 50 parts by weight, with respect to 100 parts by weight of the carbon fiber. The amount is preferably 150 parts by weight or less. In addition, the outermost layer and the outermost layer preferably contain 90% by weight or more, in particular 95 to 100% by weight, of the reinforcing fibers and the thermoplastic resin as main components. When the thermoplastic resin content in the outermost and back layers is 50 parts by weight or more with respect to 100 parts by weight of the carbon fibers, it becomes easy to secure a sufficient amount of carbon fibers in the outermost and back layers, and the thermoplastic resin laminate is bent. It becomes easy to ensure rigidity.

The thickness of the outermost layer is 0.1 mm or more, preferably 0.2 mm or more, and more preferably 0.3 mm or more as the thickness of each of the outermost layer and the outermost layer. More preferred.
Further, the thickness ratio of the outermost layer and the outermost layer with respect to the present laminate, that is, [(the thickness of the outermost layer / the total thickness of the present laminate) × 100] and [(the thickness of the outermost layer / the total thickness of the present laminate). ) × 100] is preferably in the range of 2 to 30%. Although the thickness of the outermost layer and the outermost layer may be different, it is preferable that they are the same from the viewpoint of suppressing warpage of the laminate.

  The outermost layer is usually produced by producing a sheet containing the above-described carbon fiber and laminating one or more carbon fiber sheets. Alternatively, a carbon fiber sheet and a thermoplastic resin sheet may be respectively produced and laminated. At that time, if necessary, a reinforcing fiber sheet other than carbon fiber, or a reinforcing fiber other than carbon fiber and a thermoplastic resin sheet may be laminated and used.

  The method for producing the carbon fiber sheet is not particularly limited, but the carbon fiber sheet is preferably carbon fiber paper or carbon fiber mat. Here, both “carbon fiber paper” and “carbon fiber mat” are sheets formed by opening and dispersing fiber bundles, forming them by a wet method, a dry method, etc., and making a paper into a flat film.

  The carbon fiber sheet is usually produced by either a dry nonwoven fabric method or a wet papermaking method, but it is preferable to use a carbon fiber sheet produced by a dry nonwoven fabric method from the viewpoint of better productivity and fiber opening.

  As described above, the outermost layer may include a thermoplastic resin, and a so-called prepreg in which a fiber is impregnated with a binder resin made of the above-described thermoplastic resin such as a polyolefin resin is used as a carbon fiber sheet. Also good. In general, the “carbon fiber mat” is distinguished from the “carbon fiber paper” in terms of the content and thickness of the binder resin. Usually, the carbon fiber mat has a larger binder resin content and a larger thickness than the carbon fiber paper.

The carbon fiber sheet preferably has a large basis weight (reinforcing fiber amount and binder resin) from the viewpoint of mechanical strength and impact resistance. However, in consideration of the balance between productivity and cost of the sheet itself, the carbon fiber sheet The basis weight (carbon fiber amount) is preferably 50 to 400 g / m ² , more preferably 50 to 350 g / m ² , and particularly preferably 50 to 300 g / m ² . Moreover, it is preferable that the binder resin amount of a carbon fiber sheet shall be about 0 to 70 weight% with respect to carbon fiber.

  There is no particular limitation on the thickness of the carbon fiber sheet, although it varies depending on whether the carbon fiber sheet is used as a single-layer sheet or as a laminated sheet of a plurality of carbon fiber sheets or carbon fibers and a thermoplastic resin sheet. It is about 100-5000 micrometers.

[Metal sheet layer]
The metal sheet layer is interposed between the outermost and back layers and the core layer. That is, the metal sheet layer is interposed between the outermost layer and the core layer and between the outermost layer and the core layer. The metal sheet layer is present in order to reduce the deformation amount (deflection amount) of the laminate when an impact is applied to the laminate, and the elongation at the time of the tensile test is 10% or more (conforms to JISZ2241). .
The metal sheet layer is not particularly limited as long as the elongation during the tensile test is 10% or more, but is preferably made of aluminum having a purity of 99.99% or more for the purpose of improving impact resistance.
Here, the elongation in the tensile test of the metal sheet layer is 10% or more means that the elongation when the metal sheet layer is subjected to a tensile test at a tensile strength of 60 N / mm ² and a temperature of 20 ° C. is 10% or more. .

The thickness of the metal sheet layer is preferably 0.3 mm or more, preferably 0.4 mm or more, and more preferably 0.5 mm or more from the viewpoint of impact resistance.
Further, the thickness ratio of the metal sheet layer to the present laminate, ie, [(thickness of metal sheet layer / total thickness of the present laminate) × 100] is the viewpoint of impact resistance, high rigidity, and cost of the present laminate. Therefore, it is preferably in the range of 2 to 30%, more preferably 5 to 30%, and still more preferably 10 to 30%. The thickness of the metal sheet layer interposed between the outermost layer and the core layer and the thickness of the metal sheet layer interposed between the outermost layer and the core layer may be different but are the same. It is preferable from the viewpoint that warpage of the laminate is suppressed.

The metal sheet layer is formed by laminating a thermoplastic resin sheet on the front and back of the metal sheet layer in order to improve the adhesion between the outermost and back layers including carbon fibers and the core layer; It is preferable to carry out a process for forming minute irregularities by a chemical treatment or the like for imparting the odor; or a process for combining both.
The thermoplastic resin sheet is a sheet containing the above-described thermoplastic resin, and may further contain various additives.

  As a method for forming irregularities on the front and back of the metal sheet layer, the chemical treatment described above; a method of forming holes on the metal surface with a laser; a film (such as an oxide film) is formed on the surface of the metal sheet layer; Methods for expecting chemical bonds and the like are generally disclosed, and any one or a combination thereof can be used.

[Method for producing this laminate]
The manufacturing method of this laminated body will not be restrict | limited especially if the layer structure of outermost layer / metal sheet layer / core layer / metal sheet layer / outermost layer can be formed. For example, this laminated body can be produced by laminating the sheets described in the explanation of each layer.

As described above, the metal sheet layer is preferably laminated with a thermoplastic resin sheet on the front and back of the metal sheet layer in order to improve adhesion between the outermost and back layers containing carbon fibers and the core layer.
That is, in the present invention, molding is performed with the configuration of outermost layer / thermoplastic resin layer / metal sheet layer / thermoplastic resin layer / core layer / thermoplastic resin layer / metal sheet layer / thermoplastic resin layer / outermost layer. Is preferred.

This laminated body may have other layers other than the outermost layer, the metal sheet layer, and the core layer, and in the case of providing other layers, similarly, a sheet constituting the other layers is prepared, What is necessary is just to laminate | stack another layer in an outermost surface back layer, a metal sheet layer, and a core layer. For example, when laminating a flame retardant layer or the like as another layer between the metal sheet layer and the core layer, the flame retardant is formed into a sheet shape, and the flame retardant sheet is placed between the metal sheet and the thermoplastic resin sheet. What is necessary is just to laminate. Moreover, you may mix a flame retardant with a thermoplastic resin composition, and may produce a core layer.
When another layer is provided on the outer layer of the metal sheet layer, a sheet constituting the other layer may be prepared in advance and integrated when the laminate is manufactured, or a surface layer may be further provided after the manufacture.

More specifically, the laminate is a single-layer sheet or laminate sheet for outermost and back layers; a single-layer sheet or laminate sheet for metal sheets; a single-layer sheet or laminate sheet for core layers; a heat constituting a thermoplastic resin layer. Each of the plastic resin sheets is prepared, and these are prepared as a single-layer sheet or laminated sheet for the outermost layer / single-layer sheet for thermoplastic resin or laminated sheet / sheet for metal sheet layer / single-layer sheet for thermoplastic resin layer or laminated sheet. / Single layer sheet or laminated sheet for core layer / Single layer sheet or laminated sheet for thermoplastic resin layer / Single layer sheet or laminated sheet for metal sheet layer / Single layer sheet or laminated sheet for thermoplastic resin layer / For backmost layer It can be produced by stacking single layer sheets or laminated sheets in order and press-molding at an appropriate temperature and pressure. Alternatively, it can be produced by directly laminating the constituent sheets of each layer and press-molding them at an appropriate temperature and pressure without preparing a laminated sheet for each layer in advance.
In addition, the single-layer sheet or laminated sheet for the outermost and rear layers can be obtained by using the carbon fiber sheet constituting the outermost layer as a single layer, or by laminating the required number of carbon fiber sheets and thermoplastic resin sheets. it can.
A single layer sheet or a laminated sheet for a metal sheet can be obtained by using a metal sheet as a single layer, or by laminating a required number of fiber sheets and thermoplastic resin sheets.
For the single layer sheet or laminated sheet for the core layer, the glass fiber-containing thermoplastic resin sheet constituting the core layer is used as a single layer or two or more layers, or the required number of glass fiber sheets and thermoplastic resin sheets are laminated. Can be obtained.
The thermoplastic resin sheet constituting the thermoplastic resin layer can be obtained by using the required number of thermoplastic resin sheets constituting the thermoplastic resin layer as a single layer or by laminating.

  Here, when manufacturing the laminated sheet for the outermost and back layers, the laminated sheet of the carbon fiber sheet and the thermoplastic resin sheet should be laminated by appropriately laminating one or more carbon fiber sheets and the thermoplastic resin sheet. Is preferred. When using a plurality of carbon fiber sheets, the plurality of carbon fiber sheets may be the same, or the types and thicknesses of the carbon fibers may be different. From the viewpoint of sex. When the laminated sheet for the core layer is produced by laminating a glass fiber sheet and a thermoplastic resin sheet, when two or more glass fiber-containing thermoplastic resin sheets are used, and when two or more thermoplastic resin sheets are used. It is the same.

Although press molding conditions differ also with the kind of thermoplastic resin used for each layer, as press molding temperature, the range of 170-290 degreeC is preferable, and the range of 170-280 degreeC is more preferable. Moreover, as a press pressure, the range of 0.5-6 MPa is preferable, and the range of 1-6 MPa is more preferable.
By performing press molding in such a range, a laminate having an excellent balance between mechanical strength and impact resistance can be produced.

  The laminate may be produced by a so-called batch method, or may be produced by a continuous pressing method in which these sheets are laminated and continuously press-molded while producing reinforcing fibers or thermoplastic sheets used for each layer. Good.

  The thickness (total thickness) of the laminate is not particularly limited, but is preferably 3.0 mm or more, more preferably 10.0 mm or less, and further preferably 3.5 mm or more and 10.0 mm or less. Preferably, it is 4.0 mm or more and 10 mm or less. When the thickness of the laminate is 3.0 mm or more, the laminate; and a product obtained by press-molding the laminate are excellent in surface appearance. Moreover, if the thickness of this laminated body is 10.0 mm or less, this laminated body is excellent in press moldability.

  By providing the outermost layer that mainly contributes to high rigidity and the core layer that mainly contributes to press formability within the range of the above thickness, the balance of characteristics such as uniform mold followability and mechanical strength balance during press forming is achieved. An excellent laminate can be obtained.

  In addition, it is preferable that this laminated body is set as the structure symmetrical in the thickness direction centering | focusing on a core layer from a viewpoint of suppressing curvature.

  EXAMPLES Hereinafter, examples for more specifically describing the present invention will be shown, but the present invention is not limited to the specific modes shown in the following examples.

1. Materials used (1) Carbon fiber and polyacrylonitrile-based carbon fiber used for the production of the carbon fiber sheet: manufactured by Mitsubishi Chemical Corporation, trade name “Pyrofil TR40”, elongation at break = 2.0%, fiber diameter = 7-9 μm, Fiber length 40mm

(2) Aluminum sheet / high-purity aluminum sheet: manufactured by Izumi Metal Co., Ltd., trade name “5N-H”, purity 99.999%
-General aluminum sheet: Japanese Industrial Standard (JIS) "A5052", purity 99.52%
Each aluminum sheet was subjected to a tensile test at a temperature of 20 ° C. and a tensile strength of 60 N / mm ² using a tensile tester manufactured by Shimadzu Corporation. As a result, a 0.3 mm high purity aluminum sheet and a 0.5 mm high purity were obtained. The elongation of the aluminum sheet was 15%. The elongation of the 0.5 mm general aluminum sheet was 7%.

(3) Glass fiber-containing thermoplastic resin sheet / glass fiber reinforced polypropylene plate used for preparation of core layer: Quadrant, trade name “GMT (P4038)”, glass fiber breaking elongation = 4%, glass fiber 100 Ratio of polypropylene resin to parts by weight = 150 parts by weight

(4) Thermoplastic resin (adhesive component between metal sheet layer and core layer or front and back layers)
-Polypropylene resin (PP): manufactured by Mitsubishi Chemical Corporation, trade name "Modic P908" (acid-modified PP resin)

2. Production of each sheet (1) Production of carbon fiber sheet for outermost layer formation Using a dry method for producing nonwoven fabric, a carbon fiber cut fiber having a fiber length of 40 mm is opened with a card machine, and a production method using a needle punch machine A carbon fiber sheet having a basis weight of 150 g / m ² and a thickness of 4 mm was prepared.

(2) Production of aluminum sheet for forming metal sheet layer A high-purity aluminum sheet having a thickness of 0.3 mm or 0.5 mm was used, and a general aluminum sheet having a thickness of 0.5 mm was used.
The obtained high-purity aluminum sheet and general aluminum sheet were each immersed in hydrochloric acid and immersed on the surface until the unevenness having an elevation difference of 20 μm was formed, and the surface of the aluminum sheet was made uneven.

(3) Production of glass fiber-containing thermoplastic resin sheet for core layer formation The glass fiber-reinforced polypropylene plate described above (GMT (P4038) manufactured by Quadrant Co.) was used as a glass fiber-containing thermoplastic resin sheet.

(4) Production of thermoplastic resin sheet for forming thermoplastic resin layer An acid-modified polypropylene resin (PP) (Modic P908) was melt-kneaded using an extrusion sheeting apparatus. The resin melt-kneaded from the extruder was discharged from the T die die, and a thermoplastic resin sheet (PP sheet) having a thickness of 30 μm was formed using a casting device and a take-up device.

3. Examples and Comparative Examples [Example 1]
One carbon fiber sheet (A1) as the outermost layer, five thermoplastic resin sheets (D) as the thermoplastic resin layer, one high-purity aluminum sheet (B1) (0.5 mm thickness) as the metal sheet layer, One thermoplastic resin sheet (D) as the thermoplastic resin layer, a glass fiber reinforced polypropylene plate (C) (GMT, 3.8 mm thickness) as the core layer, and a thermoplastic resin sheet (D) 1 as the thermoplastic resin layer Sheets, one high-purity aluminum sheet (B2) (0.5 mm thickness) as the metal sheet layer, five thermoplastic resin sheets (D) as the thermoplastic resin layer, and carbon fiber sheet (A2) as the backmost layer One sheet is laminated in the order of A1 / D / B1 / D / C / D / B2 / D / A2, and press-molded under the conditions of temperature = 180 ° C., pressure = 3 MPa, time = 15 minutes, thermoplastic resin Laminate It was.
When the thickness of each layer was measured about the obtained thermoplastic resin laminated body, each thickness of carbon fiber layer (outermost layer) / aluminum sheet / core layer / aluminum sheet / carbon fiber layer (outermost layer) was 0.00. It was 46 mm / 0.54 mm / 2.87 mm / 0.53 mm / 0.35 mm.

[Example 2]
The thermoplastic resin laminate was obtained in the same manner as in Example 1 except that the thicknesses of the high-purity aluminum sheets (B1) and (B2) used in the metal sheet layer of Example 1 were each 0.3 mm. .
When the thickness of each layer was measured about the obtained thermoplastic resin laminated body, each thickness of carbon fiber layer (outermost layer) / aluminum sheet / core layer / aluminum sheet / carbon fiber layer (outermost layer) was 0.00. It was 35 mm / 0.27 mm / 2.79 mm / 0.34 mm / 0.36 mm.

[Comparative Example 1]
The glass fiber reinforced PP plate used for the core layer of Example 1 was used. The thickness of this core layer was 3.63 mm.

[Comparative Example 2]
As a core layer, the glass fiber reinforced PP plate (C) of Comparative Example 1 is used, and one carbon fiber sheet (A1) is used as the outermost layer; five thermoplastic resin sheets (D) are used as the intermediate layer on the surface layer side, and carbon fibers Combination of one sheet (A1) and five thermoplastic resin sheets (D); one carbon fiber sheet (A2) as the backmost layer; five thermoplastic resin sheets (D) as the intermediate layer on the back layer side, A laminated structure in which one carbon fiber sheet (A2) and five thermoplastic resin sheets (D) are combined and laminated in the order of A1 / D / A1 / D / C / D / A2 / D / A2. Then, press molding was performed under the conditions of temperature = 180 ° C., pressure = 3 MPa, and time = 15 minutes to obtain a thermoplastic resin laminate.
When the thickness of each layer was measured about the obtained thermoplastic resin laminated body, each thickness of carbon fiber layer (outermost layer) / core layer / carbon fiber layer (outermost layer) was 0.94 mm / 2.09 mm / It was 0.97 mm.

[Comparative Example 3]
As the core layer, the glass fiber reinforced PP plate (C) of Comparative Example 1 was used, and one thermoplastic resin sheet (D) as the outermost layer; one high-purity aluminum sheet (B1) as the metal sheet layer on the outer layer side ( 0.3 mm thickness), a combination of five thermoplastic resin sheets (D) and one carbon fiber sheet (A1); one thermoplastic resin sheet (D) as the backmost layer; as a metal sheet layer on the back layer side, A combination of one carbon fiber sheet (A2), five thermoplastic resin sheets (D), and one high-purity aluminum sheet (B2) (0.3 mm thickness); D / B1 / D / Lamination was performed in the order of A1 / C / A2 / D / B2 / D, and press molding was performed under the conditions of temperature = 180 ° C., pressure = 3 MPa, and time = 15 minutes to obtain a thermoplastic resin laminate.
When the thickness of each layer was measured about the obtained thermoplastic resin laminated body, each thickness of an aluminum sheet (surface layer side) / carbon fiber layer / core layer / carbon fiber layer / aluminum sheet (back layer side) was 0.00. It was 35 mm / 0.36 mm / 2.60 mm / 0.38 mm / 0.37 mm.

[Comparative Example 4]
In the production of the thermoplastic resin laminate of Comparative Example 3, the high-purity aluminum sheets (B1) and (B2) used for the metal sheet layer were replaced with general aluminum sheets (B1) and (B2) (each 0.5 mm thick). A thermoplastic resin laminate was obtained with the same laminate configuration and pressing conditions except that the change was made to).
When the thickness of each layer was measured about the obtained thermoplastic resin laminated body, each thickness of an aluminum sheet (surface layer side) / carbon fiber layer / core layer / carbon fiber layer / aluminum sheet (back layer side) was 0.00. It was 37 mm / 0.44 mm / 2.64 mm / 0.45 mm / 0.46 mm.

3. Measurement and Evaluation The thermoplastic resin laminates produced in the examples and comparative examples were evaluated for the mechanical strength and impact resistance shown below.

(1) Mechanical strength (flexural modulus)
The produced thermoplastic resin laminate is cut to a width of 15 mm and a length of 100 mm, and a three-point bending test is performed at a distance between fulcrums = 80 mm, speed = 5.3 mm / min, temperature = 23 ° C. according to JIS K7074, and bending strength is obtained. And the flexural modulus was measured.
The flexural modulus was determined according to the following evaluation criteria, and the results are shown in Table 1.
○: 9.0 GPa or more ×: less than 9.0 GPa

(2) Impact resistance (falling ball test)
Cut the produced thermoplastic resin laminate to a width of 50 mm and a length of 150 mm, and set it in a fixed vise of the falling ball impact test device (two sides in the longitudinal direction of the test piece are bitten by 25 mm each and the distance between the vices is set to 100 mm) Then, when the falling weight (500 g) was dropped from a height of 120 cm, the state of the sample was observed, evaluated according to the following criteria, and the results are shown in Table 1.
○: No surface crack on the back side of the falling ball ×: Surface crack on the back side of the falling ball

(3) Impact resistance (deformation test)
Cut the produced thermoplastic resin laminate to a width of 50 mm and a length of 150 mm, and set it in a fixed vise of the falling ball impact test device (two sides in the longitudinal direction of the test piece are bitten by 25 mm each and the distance between the vices is set to 100 mm) Then, when the falling weight (500 g) was dropped from a height of 120 cm, the deformation of the sample was observed and evaluated according to the following criteria.
The falling surface side was placed on the surface of a flat desk, and the gap generated by measuring the gap between the desk surface and the sample was evaluated as the gap. The results are shown in Table 1. Further, the deformation amount is shown in Table 1.
○: Less than 1 mm × 1 mm or more

As shown in Table 1, the thermoplastic resin laminate of the present invention produced in the examples has an excellent balance between mechanical strength (rigidity) and impact resistance.
On the other hand, the laminate of the comparative example that does not satisfy the conditions specified in the present invention is inferior in mechanical strength (rigidity) or impact resistance.

  Since this laminate is excellent in mechanical strength, particularly bending elasticity, and impact resistance, and has a good balance between the two, and can meet the demands for light weight and low cost, It can be suitably used for various molded products such as electrical appliance casings, automobile and railway interior materials, exterior materials, and the like.

Claims (5)

A core layer containing a thermoplastic resin;
A front and back layer containing carbon fiber;
A thermoplastic resin laminate having a metal sheet layer having an elongation during tensile test of 10% or more between the core layer and the outermost layer.   The thermoplastic resin laminate according to claim 1, wherein the thickness ratio of the metal sheet layer to the laminate is 2 to 30%.   The thermoplastic resin laminate according to claim 1 or 2, wherein the carbon fibers are polyacrylonitrile-based carbon fibers.   The thermoplastic resin laminate according to any one of claims 1 to 3, wherein the metal sheet layer is made of aluminum having a purity of 99.99% or more.   The thermoplastic resin laminate according to any one of claims 1 to 4, wherein the core layer further contains glass fibers.