JP2012149170A - Carbon fiber-reinforced polyolefin-based resin composite material and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the physical properties such as strength in a carbon fiber-reinforced polyolefin-based composite material.SOLUTION: The carbon fiber-reinforced composite material contains 10-100 mm long or continuously long carbon fibers to whose surfaces a sizing agent composition containing a polyurethane resin and a polyether resin are adhered, and an acid group-containing polyolefin-based resin having an acid content (converted into maleic anhydride) of 0.05-0.5 wt.%.

Description

  The present invention relates to a composite material in which the mechanical strength and the like of a carbon fiber reinforced polyolefin resin composite material are remarkably improved, a composite material molded body, and a manufacturing method thereof.

  A fiber reinforced composite material using a thermoplastic resin as a matrix has been a material that has been attracting attention in the past because of its excellent toughness, moldability, storage stability, recyclability, and the like. Due to global environmental problems in recent years, the reduction of carbon dioxide and the recycling of materials have become important issues. As one countermeasure, it is necessary to reduce the weight with materials that can recycle automobile components. It is coming. As a material for this purpose, fiber-reinforced composite materials using a polyolefin resin as a matrix have attracted attention, and the development of processing techniques is progressing.

  As a method for improving the physical properties of a carbon fiber reinforced polyolefin resin composite material, a fiber comprising a carbon long fiber surface-treated with a sizing agent having a functional group capable of reacting with an acid group-containing polyolefin resin and an acid group-containing polyolefin resin Carbon long fiber reinforced resin pellets having a length of 4 to 50 mm have been proposed (see Patent Document 1). However, the above technique relates to long fiber injection molding, and the carbon fiber length after injection molding is several mm, and the strength is not sufficient.

JP 2005-125581 A

  An object of the present invention is to improve physical properties such as strength in a carbon fiber reinforced polyolefin resin composite material and to establish a manufacturing method thereof.

  The present inventors have found that the subject can be solved by using a long-fiber carbon fiber having a sizing agent including a polyurethane resin and a polyether resin attached to the surface. That is, the present invention is a carbon fiber having a fiber length of 10 mm to 100 mm or continuous carbon fiber, a carbon fiber having a sizing agent containing a polyurethane resin and a polyether resin attached to the surface, and an acid content in terms of maleic anhydride, A carbon fiber reinforced composite material comprising 0.05 to 0.5% by weight of an acid group-containing polyolefin resin, and a composite material molded body obtained by shaping the carbon fiber reinforced composite material into a three-dimensional shape.

  According to the present invention, the carbon fiber reinforced composite in which the opening property of the carbon fiber is improved, the impregnation property of the acid group-containing polyolefin resin of the matrix is improved, and the carbon fiber and the acid group-containing polyolefin resin are more firmly bonded. A material is obtained, and a carbon fiber-reinforced composite material molded body shaped into a three-dimensional shape with significantly improved mechanical properties can be provided.

Schematic (perspective view and cross-sectional view) of a molded body produced in Example 15.

Hereinafter, embodiments of the present invention will be sequentially described.
[Sizing composition]
The carbon fiber constituting the carbon fiber reinforced composite material of the present invention is obtained by attaching a sizing composition containing a polyurethane resin and a polyether resin to the surface. The polyurethane resin contained in the sizing composition is preferably a reaction product of aromatic isocyanate and polyether or polyester. Examples of the aromatic isocyanate include tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, xylene diisocyanate, naphthylene-1,5-diisocyanate, mono- or dichlorophenylene-2,4-diisocyanate, and diphenylmethane-4,4. Diisocyanates such as' -diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 3-methyldiphenylmethane-4,4'-diisocyanate, metaphenylene diisocyanate, paraphenylene diisocyanate, diphenyl ether diisocyanate, pitolylene diisocyanate; And triisocyanates such as triphenylmethane triisocyanate.

  Examples of polyethers include addition polymerization of one or more alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to polyhydric alcohols such as ethylene glycol, propylene glycol, butylene recall, glycerin, and trimethylolpropane. Polyether having a hydroxyl group at the terminal, polyoxytetramethylene glycol which is a ring-opening heavy compound of tetrahydrofuran, alkylene oxide addition polymer of polyhydric phenols such as bisphenol, succinic acid, adipic acid, fumaric acid, maleic acid And alkylene oxide addition polymers of polybasic carboxylic acids such as glutaric acid, azelaic acid, phthalic acid, terephthalic acid, dimer acid and pyromellitic acid.

  Examples of the polyester include a condensate of the above-mentioned polyhydric alcohol and the above-mentioned polybasic carboxylic acid, a condensate of the above-mentioned polyhydric alcohol with a hydroxycarboxylic acid such as castor oil or castor oil fatty acid, and the like.

  Polyurethane resin has aromatic isocyanate as tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate and / or diphenylmethane-4,4′-diisocyanate, polyether as polyethylene glycol, and / or polypropylene glycol, polyester However, polyethylene adipate and / or polybutylene sebacate can be preferably used.

  As a specific example, as a reaction product of aromatic isocyanate and polyether, HYDRAN HW-312B, VONDIC 1040NS, VONDIC 1050B-NS, VONDIC 1310NSC, VONDIC 1320NSC, VONDIC 1510 (above, manufactured by Dainippon Ink & Chemicals, Inc.), Examples of the reaction product of aromatic isocyanate and polyester include HYDRANHW-301, HYDRAN HW-310, HYDRAN HW-311, HYDRANHW-333, HYDRAN HW-340, HYDRANHW-350, VONDIV 1230NS, VONDIC 1250 (above, Dainippon Ink Chemical Co., Ltd.) Kogyo Co., Ltd.).

The polyether resin contained in the sizing agent composition is preferably represented by the following formula (1).
R ₁ —O— (CH ₂ CH ₂ O) _m —R ₂ (1)
(In the formula, R ₁ represents an alkyl group having 1 to 30 carbon atoms, bisphenol A, and a phenyl group, R ₂ represents hydrogen or a glycidyl group, and m represents an integer of 1 to 60.)

Specific examples include polyoxyethylene (m) lauryl glycidyl ether, polyoxyethylene (m) lauryl ether, ethylene oxide (m) adduct of bisphenol A, polyoxyethylene (m) phenyl glycidyl ether, polyoxyethylene (m ) Phenyl ether and the like.
Although there is no restriction | limiting in particular in polyether resin, Polyoxyethylene (m) lauryl glycidyl ether or the ethylene oxide (m) addition product of bisphenol A can use it conveniently.

In the present invention, the blending ratio of polyurethane resin / polyether resin in the sizing composition is preferably 40/60 to 90/10. By using this blending ratio, a strand having both stranding property and opening property can be obtained.
When the blending ratio of the polyurethane resin is less than 40, the scratch resistance is lowered and fluff is likely to occur. When the blending ratio of the polyurethane resin exceeds 90, the fiber opening property is deteriorated, and the impregnation property of the matrix resin with respect to the carbon fiber strand may be lowered.

  The sizing composition is a resin composition in which a polyurethane resin and a polyether resin are mixed as essential components, but a higher fatty acid ester can be included as a third component. Specific examples of higher fatty acid esters include stearic acid esters such as methyl stearate, ethyl stearate, propyl stearate, butyl stearate, octyl stearate, and stearyl stearate, and oleic acid esters such as isopropyl palmitate. It is done. The blending amount of the higher fatty acid as the third component is preferably in the range of 5 to 20% by weight when the entire sizing composition is 100% by weight. When the blending amount of the higher fatty acid exceeds 20% by weight, the mechanical properties when formed into a molded product may be deteriorated.

As the form when the sizing composition is adhered to the carbon fiber strand, an aqueous solution, an aqueous dispersion, a solution dissolved in an organic solvent, or the like is used. However, in consideration of a safety environment, an aqueous solution or an aqueous dispersion is preferable.
The amount of sizing composition attached to 100 parts by weight of carbon fiber is preferably 0.1 to 3.0 parts by weight, and more preferably 0.3 to 1.8 parts by weight.

  When the adhesion amount of the sizing composition is less than 0.1 parts by weight, good scratch resistance may not be obtained. When the adhesion amount of the sizing agent exceeds 3.0 parts by weight, the carbon fiber strand becomes stiff and the openability tends to be lowered, so that the impregnation property of the acid group-containing polyolefin resin to the carbon fiber strand is lowered. There is a case. In the present invention, examples of the method for attaching the sizing composition to the carbon fiber include a commonly used dipping method, roller transfer method, and / or spray method. Moreover, adjustment of the adhesion amount of the sizing agent composition to the carbon fiber is performed by adjusting the concentration of the sizing agent solution, squeezing roller, strand tension or the like. The carbon fiber after sizing application is dried. The drying means is not particularly limited, and may be a commonly used drying means such as hot air drying, far-infrared drying, or drying with a heat roller.

[Carbon fiber]
As the carbon fiber constituting the carbon fiber reinforced composite material of the present invention, any carbon fiber such as polyacrylonitrile (PAN), petroleum / coal pitch, rayon, and lignin can be used. In particular, PAN-based carbon fibers using PAN as a raw material are preferable because they are excellent in productivity and mechanical properties on an industrial scale.
Specifically, PAN-based carbon fibers having an average diameter of 5 to 10 μm can be used. As the PAN-based carbon fiber, a fiber bundle of 1000 to 50000 single fibers can be used.

  In order to enhance the adhesion between the carbon fiber and the matrix resin, it is also preferable to use a material in which an oxygen-containing functional group is introduced on the surface of the carbon fiber by a surface treatment. As the surface treatment method, known methods include liquid phase and gas phase treatment, but liquid phase electrolytic surface treatment is preferable from the viewpoint of productivity, stability, price and the like. It is preferable to manage by the surface oxygen concentration ratio O / C of the carbon fiber measured by X-ray photoelectron spectroscopy (ESCA) as an index of the degree of performing this surface treatment. The surface oxygen concentration ratio O / C of the carbon fiber is measured as follows using, for example, an X-ray photoelectron spectrometer ESCA JPS-9000MX manufactured by JEOL Ltd. The carbon fiber before sizing is irradiated with X-rays generated under conditions of an electron beam acceleration voltage of 10 kV and a current of 10 mA using Mg as a counter electrode, and the spectrum of photoelectrons generated from carbon atoms and oxygen atoms is measured. Calculate the ratio. The degree of surface treatment of the carbon fiber is preferably carried out so that the surface oxygen concentration ratio O / C is 0.03 to 0.2. When the surface oxygen concentration ratio O / C exceeds 0.2, the molecular weight of the matrix resin is reduced, and the original performance as a fiber-reinforced composite material tends not to be exhibited.

On the other hand, when the surface oxygen concentration ratio O / C is less than 0.03, the adhesion between the carbon fiber and the matrix resin is insufficient, and the mechanical properties in the fiber-reinforced composite material tend not to be sufficiently exhibited.
By giving the sizing composition to the carbon fiber to form a carbon fiber bundle, the handleability of the carbon fiber bundle can be improved, and the carbon fiber reinforced composite material of the present invention can be preferably obtained.

[Acid group-containing polyolefin resin]
The acid group-containing polyolefin resin constituting the carbon fiber reinforced composite material of the present invention has an acid content of 0.05 to 0.5% by weight in terms of maleic anhydride, preferably 0.07 to 0.00. 4% by weight, particularly preferably 0.1 to 0.3% by weight.

  The acid group-containing polyolefin resin is preferably acid-modified polyolefin (a) alone or a mixture of acid-modified polyolefin (a) and polypropylene (b). In the case of a mixture, the weight ratio of acid-modified polyolefin (a) / polypropylene (b) is preferably 50/50 to 1/99. If the amount of the acid-modified polyolefin (a) is too small, the impregnation and adhesion of the resin to the carbon fiber will be insufficient, so that it is difficult to obtain a composition with dramatically improved strength. If it is too large, the processability may be impaired and the characteristics of the polyolefin resin may be lost. The acid-modified polyolefin (a) is preferably maleic acid-modified polypropylene and / or maleic anhydride-modified polypropylene.

  The acid-modified polyolefin (a) is obtained by graft polymerization of an unsaturated carboxylic acid or a derivative thereof to an olefin homopolymer or a copolymer of two or more olefins. These acid-modified polyolefins may be used as a mixture of two or more.

  Here, examples of the unsaturated carboxylic acid used for modification include carboxyl groups such as maleic acid, fumaric acid, itaconic acid, acrylic acid, and methacrylic acid, and hydroxyl groups, amino groups, and epoxy groups as necessary. Examples thereof include compounds having a polymerizable double bond into which a functional group is introduced. Examples of unsaturated carboxylic acid derivatives include these acid anhydrides, esters, amides, imides, metal salts, and the like. Specific examples thereof include maleic anhydride, itaconic anhydride, methyl acrylate, ethyl acrylate, Butyl acrylate, glycidyl acrylate, methyl methacrylate, ethyl methacrylate, glycidyl methacrylate, maleic acid monoethyl ester, maleic acid diethyl ester, fumaric acid monomethyl ester, fumaric acid dimethyl ester, acrylamide, methacrylamide, maleic acid monoamide, Mention may be made of maleic acid diamide, fumaric acid monoamide, maleimide, N-butylmaleimide, sodium methacrylate and the like. Of these, glycidyl esters of acrylic acid and methacrylic acid and maleic anhydride are preferred.

  Preferred acid-modified polyolefins (a) include those modified by graft polymerization of maleic anhydride to an olefin polymer mainly composed of ethylene and / or propylene, and olefins mainly composed of ethylene and / or propylene. And those modified by copolymerizing glycidyl ester of (meth) acrylic acid or maleic anhydride.

  The acid-modified amount of the acid-modified polyolefin (a) is 0.05 to 10% by weight, preferably 0.07 to 5% by weight, particularly preferably 0.1 to 3% by weight in terms of maleic anhydride. The component of the unsaturated carboxylic acid or its derivative is introduced into the polymer chain by random or block copolymerization with a monomer for polyolefin or graft polymerization to polyolefin.

  The polypropylene (b) includes, in addition to propylene units, as a copolymerization component, ethylene, an α-olefin other than propylene, a cyclic olefin, and the like. Examples of the α-olefin include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 4-methyl-1-pentene, and the like. it can. Cyclic olefin monomers include cyclobutene, cyclopentene, cyclopentadiene, 4-methylcyclopentene, 4,4-dimethylcyclopentene, cyclohexene, 4-methylcyclohexene, 4,4-dimethylcyclohexene, 1,3-dimethylcyclohexene, 1,3. -Cyclohexadiene, 1,4-cyclohexadiene, cycloheptene, 1,3-cycloheptadiene, 1,3,5-cycloheptatriene, cyclooctene, 1,5-cyclooctadiene, cyclododecene and the like can be mentioned. These copolymers can take the structure of a random copolymer, a block copolymer, and a graft copolymer. A preferable copolymer molar ratio when it contains a copolymer component is 0.1 to 50%.

  Specific examples of the acid group-containing polyolefin resin include a polyethylene / ethylene / glycidyl methacrylate copolymer, a polyethylene / maleic anhydride grafted ethylene / butene-1 copolymer combination, or a polypropylene / maleic anhydride graft. Examples include a combination of polypropylene.

[Uniaxially oriented carbon fiber reinforced composite material]
A carbon fiber having a uniaxially oriented carbon fiber in which carbon fibers and acid group-containing polyolefin resin are combined by aligning continuous length carbon fiber bundles and bringing them into contact with molten acid group-containing polyolefin resin A composite material can be obtained (this may be referred to as a uniaxially oriented carbon fiber reinforced composite material).

The method for producing the uniaxially oriented carbon fiber reinforced composite material is not particularly limited, and can be obtained by, for example, a pultrusion method. In the case of the pultrusion method, carbon fibers impregnated with an acid group-containing polyolefin resin are preferably obtained. In the case where the impregnation with the acid group-containing polyolefin resin is suppressed, that is, when it is a semi-impregnated layer, for example, the carbon fiber is aligned in one direction on the sheet made of the acid group-containing polyolefin resin, and pressed as necessary. It can obtain preferably by the method of heating.
The weight ratio of carbon fiber / acid group-containing polyolefin resin in the uniaxially oriented carbon fiber reinforced composite material is preferably 20/80 to 80/20. More preferably, it is 30 / 70-70 / 30.

[Random matte carbon fiber reinforced composite material]
The carbon fiber to be used can be a discontinuous carbon fiber, and can be a carbon fiber reinforced composite material in which the carbon fiber is a random mat, including a randomly arranged carbon fiber and an acid group-containing polyolefin resin. From the viewpoint of obtaining a composite material that ensures strength, the carbon fiber length in the composite material is 10 to 100 mm. That is, the present invention comprises a carbon fiber bundle having a fiber length of 10 to 100 mm and an acid group-containing polyolefin resin, and the carbon fiber is substantially in-plane with a basis weight of 25 to 3000 g / m ^2. It includes a random mat characterized by being randomly oriented. (This may be referred to as a random matte carbon fiber reinforced composite material).

The weight ratio of carbon fiber / acid group-containing polyolefin resin in the random mat carbon fiber reinforced composite material is preferably 20/80 to 80/20. More preferably, it is 30 / 70-70 / 30.
In the random mat carbon fiber reinforced composite material, the acid group-containing polyolefin-based resin is preferably present in the form of fibers, powders, or granules.

The random mat is 1. Cutting the carbon fiber bundle,
2. A process of opening the fiber bundle by introducing cut carbon fiber into the tube and blowing air on the fiber;
3. An application process in which the carbon fiber and the thermoplastic resin are simultaneously sprayed while spreading the spread carbon fiber and sucking it together with the thermoplastic resin.
4). Fixing the applied carbon fiber and thermoplastic resin;
More preferably.

[Method for producing carbon fiber reinforced composite material]
The carbon fiber reinforced composite material of the present invention is impregnated by heating and pressing an acid group-containing polyolefin resin at a temperature equal to or higher than the melting point, that is, hot press molding, on a carbon fiber having a sizing composition attached to the surface. It can manufacture preferably. As described above, the shape of the carbon fiber may be a uniaxially oriented material or a random mat, but a plurality of these may be stacked to have a desired thickness.

  The heating temperature in the hot press molding of the present invention is preferably 230 ° C to 300 ° C. More preferably, it is preferable to set it as 230 to 270 degreeC. The heating time in hot press molding is preferably 30 seconds or longer. More preferably, it is 40 seconds or more. If the heating time is less than 30 seconds, the physical property improvement of the carbon fiber reinforced composite material may be small. A longer heating time is better, but if it is too long, further improvement cannot be expected, and productivity may be reduced.

[Composite material compact]
The present invention includes a composite material molded body obtained by shaping a carbon fiber reinforced composite material into a three-dimensional shape. Specifically, the above-mentioned carbon fiber reinforced composite material is heated to 150 to 300 ° C., then press-molded with a 30 to 150 ° C. mold and shaped into a three-dimensional shape, thereby shaping into a three-dimensional shape. A carbon fiber reinforced composite material molded body can be obtained.

  Combining a random mat carbon fiber reinforced composite material in which the form of carbon fibers in one of the carbon fiber reinforced composite materials is a random mat and a uniaxially oriented carbon fiber reinforced composite material in which the form of carbon fibers is a uniaxially oriented material, It is also preferable to form a carbon fiber composite molded body by shaping it into a three-dimensional shape. In this case, the volume ratio, the area ratio, and the lamination portion of the laminated portion can be appropriately selected according to various uses. In this case, it is more preferable that the uniaxially oriented carbon fiber reinforced composite material is present in an amount of 5 to 50% by volume based on the total volume of the composite material molded body for the purpose of obtaining a molded body with increased rigidity. Among them, the uniaxially oriented carbon fiber reinforced composite material is preferably arranged so as to effectively exhibit desired torsional rigidity and bending rigidity.

There are no particular restrictions on the heating method and conditions in the method for producing a carbon fiber reinforced composite material molded into a three-dimensional shape, but oven heating and IR heating are preferred. The heating temperature is more preferably 180 ° C to 250 ° C.
In addition, the mold temperature in the case of three-dimensional shaping with a mold is more preferably 50 ° C to 130 ° C. The press pressure and press time can also be appropriately selected.

Examples are shown below, but the present invention is not limited thereto.
[raw materials]
Acid group-containing polyolefin resin Acid-modified polypropylene (1): Toyotac (registered trademark) PMAH1000P
(Toyobo Co., Ltd., modified with 5.0% by weight maleic anhydride)
Acid-modified polypropylene (2): Yumex (registered trademark) 1010
(Manufactured by Sanyo Chemical Co., Ltd., maleic anhydride modified by 4.5% by weight)
Acid-modified polypropylene (3): OREVAC (registered trademark) CA100
(Manufactured by Arkema, modified with 1.0% by weight maleic anhydride)
Polypropylene mixed with the acid-modified polypropylene: Prime Polypro (registered trademark) J108M
(Manufactured by Prime Polymer)

(1) Bending physical property measurement method of composite material molded plate The bending test in the following examples is a three-point bending by cutting a test piece of width 15 mm × length 100 mm from the molded plate and using a central load in accordance with JIS K7074. evaluated. Maximum load and center deflection when a test piece is placed on a fulcrum of r = 2mm with a fulcrum distance of 80mm and a load is applied at a test speed of 5mm / min with an indenter of r = 5mm in the center between the fulcrum The bending strength and the bending elastic modulus were measured.

[Example 1]
45% by weight of HYDRAN HW-301 (polyester urethane, manufactured by Dainippon Ink & Chemicals, Inc.) as the polyurethane resin, and polyoxyethylene (15) lauryl glycidyl ether (POE (15) LGE: Matsumoto Yushi Seiyaku Co., Ltd.) as the polyether resin A resin composition having a blending amount of 55% by weight was dissolved in water to prepare a sizing agent solution having a concentration of 30 g / l. In this sizing solution bath, unsized carbon fiber strand (manufactured by Toho Tenax Co., Ltd., registered trademark “Tenax STS-24K N00”, diameter 7 μm × 24000 filament, fineness 1.6 g / m, tensile strength 4000 MPa, tensile elasticity Then, excess water was removed with a roller and dried at 140 ° C. for 3 minutes to continuously obtain carbon fiber strands. The amount of sizing agent attached to the carbon fiber was 1.2% by weight.
The obtained carbon fiber strand is slidably contacted with four spread bars arranged in a zigzag along the traveling direction, and spreads up to a width of 16 mm, and above and below the sheet aligned in one direction, to 100 parts by weight of carbon fiber. On the other hand, the acid-modified polypropylene resin film (prime polymer Prime Polypro J108M 96% by weight, maleic anhydride-modified polypropylene (Toyobo Toyo Tac PMA1000P)) 4% by weight so as to be 52 parts by weight of acid-modified polypropylene resin. What was mixed with a rotary blender and made into a 30μ thick film with an extruder. The acid amount in the total resin is 0.20% by weight), and uniaxially oriented carbon fiber with a 220 ° C heating roller A reinforced composite sheet was obtained. The carbon fiber basis weight of the uniaxially oriented carbon fiber reinforced composite material sheet was 100 g / m ² , and the volume content of the carbon fiber was 50 vol%.
This uniaxially oriented carbon fiber reinforced composite material sheet was cut into a size of 30 cm wide × 30 cm long, 18 sheets were stacked in one direction, and heated at 2.0 MPa for 5 minutes in a press apparatus heated to 240 ° C. A 0 mm shaped plate was obtained.
The bending properties of the obtained molded plate in the 0 ° direction were a bending strength of 880 MPa and a bending elastic modulus of 105 GPa.

[Examples 2 to 4]
A molded plate was obtained in the same manner as in Example 1, except that the total acid amount in the acid group-containing polypropylene resin and the amount of carbon fiber sizing agent attached were changed as shown in Table 1. The results are shown in Table 1.

[Example 5]
50% by weight of HYDRAN HW312B (polyether urethane, manufactured by Dainippon Ink & Chemicals, Inc.) as a polyurethane resin, and an ethylene oxide (10) adduct of bisphenol A as a polyether resin (POE (10) bisA: Matsumoto Yushi Seiyaku Co., Ltd.) A resin composition comprising 10% by weight of an emulsion of octyl stearate (manufactured by Shin Nippon Rika Co., Ltd., ENGELUB OS) as a third component is dissolved in water at a concentration of 30 g / A shaped plate having a thickness of 2.0 mm was obtained with a press apparatus heated to 240 ° C. in the same manner as in Example 1 except that the sizing agent solution 1 was prepared.
The bending properties of the obtained molded plate in the 0 ° direction were a bending strength of 870 MPa and a bending elastic modulus of 105 GPa.

[Example 6]
As an acid-modified polypropylene resin film, a primer polymer made of Prime Polypro J108M 96% by weight, maleic anhydride-modified polypropylene (Yumex 1010 manufactured by Sanyo Chemical Co., Ltd.) 4% by weight, and pellets mixed with a rotary blender is used for extrusion. A molded plate having a thickness of 2.0 mm was obtained in the same manner as in Example 5 except that a 30 μm thick film was used (the acid amount in the total resin was 0.18% by weight).
The bending properties of the obtained molded plate in the 0 ° direction were a bending strength of 860 MPa and a bending elastic modulus of 105 GPa.

[Example 7]
As an acid-modified polypropylene resin film, a primer polymer made of Polypropylene J108M 85% by weight, maleic anhydride-modified polypropylene (OREVAC CA100 manufactured by Arkema Co., Ltd.) 15% by weight and pellets mixed with a rotary blender is used as an extruder. A molded plate having a thickness of 2.0 mm was obtained in the same manner as in Example 5 except that a film having a thickness of 30 μm was used (the acid amount in the total resin was 0.15% by weight).
The bending property of the obtained molded plate in the 0 ° direction was a bending strength of 850 MPa and a bending elastic modulus of 105 GPa.

[Examples 8 to 10]
The same procedure as in Example 5 was performed except that the heating temperature of the press device during the production of the molded plate was changed as shown in Table 2. The results are shown in Table 2.

[Example 11]
An acid-modified polypropylene resin (Prime Polymer Prime Polypro J108M 96% by weight, maleic anhydride-modified polypropylene (Toyobo Toyo Tac PMA1000P) 4% by weight, and pellets mixed with a rotary blender was kneaded with an extruder. 1) was pelletized, the pellet was frozen and pulverized, and powders having an average particle diameter of about 1 mm were prepared by classification with 20 mesh and 30 mesh.
The width of the carbon fiber treated with the sizing agent containing the polyurethane resin and the polyether resin obtained in Example 5 was cut to a length of 20 mm while opening the fiber, and the supply amount of the acid-modified polypropylene powder was changed to 465 g / min. The fiber feed rate was set to 600 g / min and introduced into the tapered tube. Air was blown onto the carbon fiber in the taper tube to partially open the fiber bundle, and the fiber bundle was sprayed on a table installed at the bottom of the taper tube outlet together with polypropylene powder. The dispersed carbon fiber and polypropylene powder were sucked from the lower part of the table with a blower and fixed to obtain a carbon fiber random mat having a thickness of about 5 mm.
The obtained carbon fiber random mat was cut into a size of 30 cm wide × 30 cm long and heated at 3 MPa for 5 minutes with a press apparatus heated to 240 ° C., with a total basis weight of 1400 g / m ² , thickness of 2.0 mm, carbon A molded plate made of a carbon fiber random mat carbon fiber reinforced composite material having a fiber volume content of 40 vol% was obtained.
The bending properties of the obtained molded plate were a bending strength of 290 MPa and a bending elastic modulus of 25 GPa.

[Examples 12 to 14]
The same procedure as in Example 11 was performed, except that the total acid amount in the acid group-containing polypropylene resin and the heating temperature of the press device at the time of forming the molded plate were changed as shown in Table 2. The results are shown in Table 2.

[Comparative Example 1]
The same method as in Example 1 except that as the polypropylene resin film, Prime Polypropylene J108M made of prime polymer was used to form a film having a thickness of 30 μm by an extruder (the acid amount in the total resin is 0.00% by weight). Thus, a molded plate having a thickness of 2.0 mm was obtained.
The bending properties of the obtained molded plate in the 0 ° direction were a bending strength of 340 MPa and a bending elastic modulus of 98 GPa.

[Comparative Example 2]
As Example 11, except that the pellets of Prime Polypro J108M made of Prime Polymer were freeze pulverized and further classified by 20 mesh and 30 mesh, and the average particle diameter was about 1 mm. By this method, a carbon fiber random mat composite material molded plate having a thickness of 2.0 mm was obtained.
The bending property of the obtained molded plate in the 0 ° direction was a bending strength of 100 MPa and a bending elastic modulus of 21 GPa.

[Comparative Example 3]
As epoxy resin, EP828 (bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation) is 38% by weight, EP1001 (bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation) is 45% by weight, EPU6: urethane modified epoxy resin, manufactured by Asahi Denka Co., Ltd. ) And 7% by weight of octyl stearate (Nippon Rika Co., Ltd., NJELuB OS) emulsion containing 10% by weight of the emulsion is dissolved in water to obtain a sizing agent solution having a concentration of 30 g / l. A carbon fiber strand having an epoxy resin sizing agent adhesion of 1.2% by weight was obtained in the same manner as in Example 1 except that it was produced. Although the obtained carbon fiber strands were stretched in one direction while being spread, the carbon fiber strands were not widened to a width of 16 mm, had many eyes, and a good uniaxially oriented carbon fiber composite material sheet could not be obtained.

[Comparative Example 4]
Polyurethane resin HYDRAN HW-301 (polyester urethane, manufactured by Dainippon Ink & Chemicals, Inc.) was dissolved in water, and a polyurethane resin size was obtained in the same manner as in Example 1 except that a solution having a concentration of 30 g / l was used. A carbon fiber strand having an agent adhesion amount of 1.2% by weight was obtained. Although the obtained carbon fiber strands were stretched in one direction while being spread, the carbon fiber strands were not widened to a width of 16 mm, had many eyes, and a good uniaxially oriented carbon fiber composite material sheet could not be obtained.

[Comparative Example 5]
A polyurethane resin was obtained in the same manner as in Example 1 except that HYDRAN HW-301 (polyester urethane, manufactured by Dainippon Ink & Chemicals, Inc.) was dissolved in water as the polyurethane resin and a solution having a concentration of 30 g / l was used. A carbon fiber strand having a sizing agent adhesion of 1.2% by weight was obtained. Using the obtained carbon fiber strand, a carbon fiber random mat composite material molded plate was obtained in the same manner as in Example 11. The opening of the carbon fiber was poor, and a good carbon fiber random mat composite molded plate could not be obtained.

[Example 15]
18 sheets of uniaxially oriented carbon fiber composite material sheets with a carbon fiber basis weight of 100 g / m ² obtained in Example 1 were alternately laminated at 0/90 and heated at 240 ° C. for 5 minutes at 2.0 MPa. Heating was performed to obtain a molded plate having a width of 200 mm, a length of 300 mm and a thickness of 2.0 mm. This molded plate is preheated to 240 ° C. in an IR oven, and is adjusted to a die consisting of a pair of upper and lower parts having the cross-sectional shape of the product shown in FIG. After maintaining the pressure for 30 seconds, a molded product having a thickness of 2.0 mm was taken out. The molded article was free from material cracking and wrinkling, and a good carbon fiber composite material molded body could be obtained.

[Example 16]
The product shown in FIG. 1 in which the carbon fiber random mat composite material molding plate having a width of 200 mm × a length of 300 mm obtained in Example 11 was preheated to 240 ° C. in an IR oven and the temperature of the mold was adjusted to 80 ° C. The molded product having a thickness of 2.0 mm was taken out after being kept under pressure for 30 seconds with a cold press. The molded article was free from material cracking and wrinkling, and a good carbon fiber composite material molded body could be obtained.

[Example 17]
The carbon fiber random mat composite material molding plate obtained in Example 11 was cut into a size of 200 mm in width and 300 mm in length, and above and below the carbon fiber basis weight 100 g / m ² uniaxially oriented carbon fiber obtained in Example 1 A laminate of one composite material sheet was heated for 5 minutes at 3 MPa with a press apparatus heated to 240 ° C. to obtain a sandwich plate of t = 2.2 mm. The obtained sandwich plate was preheated to 240 ° C. in an IR oven, and adjusted to a die temperature of 80 ° C., followed by a pair of upper and lower molds having the cross-sectional shape of the product shown in FIG. Then, the molded product having a thickness of 2.0 mm was taken out. The molded article was free from material cracking and wrinkling, and a good carbon fiber composite material molded body could be obtained.

Claims (10)

  A carbon fiber having a fiber length of 10 mm to 100 mm or a continuous length carbon fiber having a sizing composition containing a polyurethane resin and a polyether resin attached to the surface, and an acid content in terms of maleic anhydride of 0.05 to A carbon fiber reinforced composite material comprising 0.5% by weight of an acid group-containing polyolefin resin. The polyurethane resin in the sizing composition is a reaction product of aromatic isocyanate and polyether or polyester, and the polyether resin is represented by the following chemical formula (1): polyoxyethylene (m) lauryl glycidyl ether or bisphenol 2. The carbon fiber reinforced composite material according to claim 1, which is an adduct of ethylene oxide (m) of A (m represents an integer of 1 to 60).
_{R 1 -O- (CH 2 CH 2} O) m-R 2 ··· (1)
(Wherein R ₁ represents an alkyl group having 1 to 30 carbon atoms, bisphenol A, and a phenyl group, R ₂ represents hydrogen or a glycidyl group, and m represents an integer of 1 to 60.)   The blending ratio of the polyurethane resin / polyether resin of the sizing composition is 40/60 to 90/10, and the adhesion amount of the sizing composition to 100 parts by weight of carbon fiber is 0.1 to 3.0 parts by weight. The carbon fiber reinforced composite material according to claim 1, wherein the composite material is carbon fiber reinforced composite material.   The carbon fiber-reinforced composite material according to any one of claims 1 to 3, wherein the acid group-containing polyolefin resin has an acid-modified polyolefin (a) / polypropylene (b) weight ratio of 50/50 to 1/99.   The carbon fiber-reinforced composite material according to any one of claims 1 to 4, wherein the acid-modified polyolefin (a) is maleic acid-modified polypropylene and / or maleic anhydride-modified polypropylene.   The carbon fiber reinforced composite material according to any one of claims 1 to 5, wherein a weight ratio of the carbon fiber / acid group-containing polyolefin resin in the carbon fiber composite material is 20/80 to 80/20. The carbon fiber reinforcement according to any one of claims 1 to 6, wherein the continuous-length carbon fiber is a uniaxially oriented material having a fiber basis weight of 50 to 300 g / m ² and aligned carbon fiber bundles uniaxially. Composite material. The carbon fiber according to any one of claims 1 to 6, wherein carbon fibers having a fiber length of 10 mm to 100 mm have a fiber basis weight of 25 to 3000 g / m ² and are substantially randomly oriented in a plane. Reinforced composite material.   The carbon fiber according to any one of claims 1 to 8, wherein the carbon fiber having the sizing composition attached to the surface is impregnated by hot press molding an acid group-containing polyolefin resin at a heating temperature of 230 to 300 ° C. A method for producing a reinforced composite material.   A carbon fiber reinforced composite material formed by shaping the carbon fiber reinforced composite material according to claim 1 into a three-dimensional shape.

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