JP2010058286A - Method for producing carbon fiber reinforcing thermoplastic resin molded body and carbon fiber reinforcing thermoplastic resin molded body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carbon fiber reinforcing thermoplastic resin molded body excellent in mechanical strength and a method for manufacturing the same. <P>SOLUTION: In the method for manufacturing the carbon fiber reinforcing thermoplastic resin body, a carbon fiber and a thermoplastic resin are irradiated with an electron beam in the range of 100-300 keV acceleration voltage. Usually, the carbon fiber and the thermoplastic resin are heated and compounded before and after the irradiation. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a carbon fiber reinforced thermoplastic resin molded body and a carbon fiber reinforced thermoplastic resin molded body.

  As a fiber reinforced composite material, a carbon fiber reinforced resin composed of a carbon fiber and a resin is known. Since carbon fiber reinforced resin has high mechanical strength, it has been developed as a material that can be applied in a wide range of fields such as aviation, space, sports equipment, general industrial use, civil engineering, architecture, and transportation equipment. It is out.

  As a carbon fiber reinforced resin, a carbon fiber reinforced thermoplastic resin composed of carbon fiber and a thermoplastic resin is known. The carbon fiber reinforced thermoplastic resin is useful as one of fiber reinforced composite materials because it has better moldability and is suitable for mass production as compared with the case where a thermosetting resin is used as the resin.

  However, in the conventional carbon fiber reinforced thermoplastic resin, since carbon fiber generally has poor wettability (impregnation) with respect to the thermoplastic resin, poor adhesion between the carbon fiber and the thermoplastic resin occurs, and sufficient physical properties are improved. I could n’t.

  Examples of the carbon fiber reinforced thermoplastic resin having improved wettability of the carbon fiber to the thermoplastic resin include carbon having a specific crystal size, an atomic ratio of carbon to oxygen (O / C), and an average short fiber diameter. Carbon fiber reinforced thermoplastic resins using fibers have been proposed (see, for example, Patent Document 1). In addition, carbon fiber reinforced thermoplastic resins using carbon fiber chopped strands in which the total content of monovalent or divalent metal elements and the amount of sizing agent attached are in a specific range have been proposed (for example, Patent Documents). 2). Furthermore, a carbon fiber reinforced thermoplastic resin using a modified thermoplastic resin has been proposed (see, for example, Patent Document 3).

The inventions disclosed in Patent Documents 1 to 3 above define the outer shape of the carbon fiber (the crystal size of the carbon fiber, the average short fiber diameter, etc.) and the composition of the carbon fiber or the thermoplastic resin. Although it improves the wettability with respect to the plastic resin, the mechanical strength of the carbon fiber reinforced thermoplastic resin is still insufficient.
JP 2003-128799 A Japanese Patent Application Laid-Open No. 2004-244531 JP 2005-325248 A

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a carbon fiber reinforced thermoplastic resin molded article excellent in mechanical strength and a method for producing the molded article.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have reinforced carbon fiber with excellent mechanical strength by irradiating carbon fiber and thermoplastic resin with an electron beam within a specific acceleration voltage range. The present inventors have found that a thermoplastic resin molding can be obtained and completed the present invention.

  That is, the method for producing a molded article of carbon fiber reinforced thermoplastic resin of the present invention is characterized in that an electron beam is irradiated to the carbon fiber and the thermoplastic resin in an acceleration voltage range of 100 to 300 keV.

  As a method for producing a carbon fiber reinforced thermoplastic resin molded body, the carbon fiber irradiated with the electron beam and the thermoplastic resin may be heated and combined after the irradiation, and the electron beam irradiation dose in the irradiation is set to 0. It is preferably in the range of 1 to 0.9MGy.

  As a method for producing a carbon fiber reinforced thermoplastic resin molding, carbon fiber and a thermoplastic resin may be combined by heating before the irradiation, and the electron beam irradiation dose in the irradiation is 0.1 to 0.5 MGy. It is preferable that it is the range of these.

  Moreover, the carbon fiber reinforced thermoplastic resin molding obtained by the said manufacturing method is contained in this invention.

  The carbon fiber reinforced thermoplastic resin molding obtained by the method for producing a carbon fiber reinforced thermoplastic resin molding of the present invention is a conventional carbon fiber that does not irradiate both the carbon fiber and the thermoplastic resin with an electron beam. Excellent mechanical strength compared to reinforced thermoplastic resin moldings.

  Further, the carbon fiber reinforced thermoplastic resin molding obtained by the method for producing a carbon fiber reinforced thermoplastic resin molding of the present invention is used in various industries such as aircraft, space rocket, automobile, transportation equipment, sports equipment, civil engineering and building equipment. It can be used as products and machine parts in the field.

Next, the present invention will be specifically described.
The method for producing a molded article of carbon fiber reinforced thermoplastic resin of the present invention is characterized in that an electron beam is irradiated to the carbon fiber and the thermoplastic resin in an acceleration voltage range of 100 to 300 keV. In the present invention, in order to prevent radiation damage of the thermoplastic resin and carbon fiber and generation of X-rays, and to prevent deformation and melting of the thermoplastic resin and carbon fiber due to heating, the acceleration voltage is 100 to 300 keV, preferably Electron beam irradiation is performed in the range of 120 to 200 keV, more preferably 150 to 180 keV.

The irradiation time of the electron beam is usually 0.2 to 5.0 seconds, and the temperature at the time of electron beam irradiation is usually in the range of room temperature to 50 ° C.
In the method for producing a carbon fiber reinforced thermoplastic resin molded body of the present invention, both the carbon fiber and the thermoplastic resin are irradiated with an electron beam, and the carbon fiber reinforced thermoplastic resin obtained by the production method of the present invention is used. The molded body is excellent in mechanical strength. The reason for this is not clear, but the present inventors irradiate both carbon fiber and thermoplastic resin with an electron beam, so that wettability of carbon fiber to thermoplastic resin and interfacial adhesion between carbon fiber and thermoplastic resin. It was estimated that the properties improved and the mechanical strength was excellent.

(Carbon fiber)
The carbon fiber used in the present invention is not particularly limited, and for example, carbon fiber produced through a carbonization process from acrylic fiber or fiber produced from pitch, rayon or the like is used. The carbon fiber is produced, for example, by a method in which an acrylic fiber mainly composed of acrylonitrile is heated and oxidized and further carbonized in an inert atmosphere. In addition, as the carbon fiber used in the present invention, a carbon fiber produced from an acrylic fiber is preferable because of excellent industrial productivity and excellent mechanical properties. The acrylic fiber is not particularly limited as long as it contains a monomer component that accelerates the flameproofing reaction. Examples of the monomer component include itaconic acid, acrylic acid, methacrylic acid and methyl esters, ethyl esters, and propyl esters thereof. , Alkali metal salts, ammonium salts, or allyl sulfonic acid, methacryl sulfonic acid, styrene sulfonic acid, and alkali metal salts thereof. In addition, it is preferable to apply a wet spinning method or a dry and wet spinning method as a spinning method of the raw fiber, but there is no particular limitation.

  The carbon fiber used in the present invention may be surface-treated with a coupling agent such as a silane coupling agent or a titanate coupling agent, or a sizing agent such as a urethane resin, an epoxy resin, or a polyester resin.

  As the carbon fiber used in the present invention, short fibers cut to a length of about 1 to 25 mm may be separated, or may be used in the form of, for example, a tow (a bundle of many filaments). In addition, long fibers or continuous fibers may be used in a shape in which they are aligned in the width direction, and further, they may be used after being changed to a woven fabric, a knitted fabric, or a nonwoven fabric.

Moreover, the said carbon fiber may be used individually by 1 type, and may mix and use 2 or more types.
The amount of carbon fiber used in the present invention is such that the proportion of carbon fiber in the carbon fiber reinforced thermoplastic resin molding obtained by the production method of the present invention is 10 to 90% by volume, preferably 20 to 65% by volume (however, The amount is preferably in the range of 100% by volume of the carbon fiber reinforced thermoplastic resin molding. In the said range, since the carbon fiber reinforced thermoplastic resin molding obtained by the manufacturing method of this invention has the high mechanical strength, maintaining the softness | flexibility which a thermoplastic resin has, it is preferable.

(Thermoplastic resin)
There is no limitation in particular as a thermoplastic resin used for this invention, Various thermoplastic resins, such as a general purpose resin, a heat resistant resin, and an engineering resin, can be used.

  Examples of the thermoplastic resin used in the present invention include polyolefins such as polyethylene and polypropylene; poly (meth) acrylates such as polystyrene, polymethyl methacrylate, polyethyl methacrylate, polymethyl acrylate, and polyethyl acrylate, Vinyl polymers such as acrylonitrile / butadiene / styrene copolymer and acrylonitrile / styrene copolymer; nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, nylon 612, nylon 61, nylon 6T, nylon 9T Such as polyamide, polyethylene terephthalate, polyester such as polybutylene terephthalate, condensation polymers such as polycarbonate, polyimide; polyacetal; polyphenylene oxide; polyphenylene sulfide; Li polyethersulfone and the like.

  Among these, polypropylene, polycarbonate, polyamide, polyethylene terephthalate, polybutylene terephthalate, polyacetal, polyphenylene oxide, polyphenylene sulfide, and polyethersulfone are preferable in terms of mechanical strength, heat resistance, workability, and the like.

Moreover, the said thermoplastic resin may be used individually by 1 type, and may blend and use 2 or more types.
The amount of the thermoplastic resin used in the present invention is such that the proportion of the thermoplastic resin in the carbon fiber reinforced thermoplastic resin molding obtained by the production method of the present invention is 10 to 90% by volume, preferably 35 to 80% by volume ( However, it is preferable that the amount be in the range of 100% by volume of the carbon fiber reinforced thermoplastic resin molding. In the said range, since the carbon fiber reinforced thermoplastic resin molding obtained by the manufacturing method of this invention has the high mechanical strength, maintaining the softness | flexibility which a thermoplastic resin has, it is preferable.

The shape of the thermoplastic resin is preferably a film or a sheet from the viewpoint of uniform electron beam irradiation.
(Additive)
In this invention, various additives may be contained as components other than the said carbon fiber and a thermoplastic resin.

  Examples of additives include fillers, flame retardants, flame retardant aids, pigments, dyes, lubricants, mold release agents, compatibilizers, dispersants, crystal nucleating agents, plasticizers, heat stabilizers, antioxidants, Any colorant, UV absorber, fluidity modifier, foaming agent, antibacterial agent, vibration control agent, deodorant, sliding property modifier, conductivity imparting agent, antistatic agent, stiffness imparting agent, etc. Additives can be used.

As the release agent, for example, polyvinyl alcohol (PVA) or wax can be used.
In the carbon fiber reinforced thermoplastic resin molding of the present invention, when an additive is included, it is usually 0.1 to 50 parts by weight, preferably 0.5 to 30 parts by weight, based on 100 parts by weight of the thermoplastic resin. Part contained.

  In the method for producing a molded article of carbon fiber reinforced thermoplastic resin of the present invention, the carbon fiber and the thermoplastic resin are usually integrated by heat compounding or the like. The integration may be performed before irradiating the carbon fiber and the thermoplastic resin with the electron beam or after irradiating the electron beam.

  In addition, in order to integrate carbon fiber and a thermoplastic resin, it can carry out by normal heating compounding. The heat composite means that the carbon fiber and the thermoplastic resin are integrated under heat and pressure. As a method for heat compounding, there is a method in which carbon fibers are sandwiched between thermoplastic resin films and integrated under heat and pressure. Further, the conditions for the heat compounding are not particularly limited, but preferably 0.02 to 0.02 at an applied gas pressure of 4 to 3000 kPa at a temperature at which the thermoplastic resin softens or a temperature higher than the melting point in an inert gas atmosphere. By holding for 2 minutes, heating and compounding can be performed.

  In the production method of the present invention, the carbon fiber and the thermoplastic resin are usually heat-combined. However, the production method of the present invention has two modes: a mode in which heat-combination is performed before irradiation with an electron beam and a mode in which irradiation is performed after irradiation. It can be roughly divided into one aspect. Each aspect will be described below.

(First aspect)
The first aspect of the method for producing a carbon fiber reinforced thermoplastic resin molding of the present invention is a carbon fiber reinforced thermoplastic resin molding in which an acceleration voltage is in the range of 100 to 300 keV and the carbon fiber and the thermoplastic resin are irradiated with an electron beam. In the method for producing a body, after the irradiation, the carbon fiber irradiated with the electron beam and the thermoplastic resin are combined by heating.

In a 1st aspect, it is preferable that the electron beam irradiation dose in the said irradiation is the range of 0.1-0.9MGy, and it is more preferable that it is the range of 0.2-0.8MGy.
When the electron beam irradiation dose is in the above range, the mechanical properties such as tensile strength, bending strength, and impact strength of the obtained carbon fiber reinforced thermoplastic resin molded product can be compared with the conventional carbon fiber reinforced thermoplastic resin molded product. Since it improves compared with it, it is preferable.

  As a specific example of the first aspect, in the method for producing a carbon fiber reinforced thermoplastic resin molded body in which an electron beam is irradiated to the carbon fiber and the thermoplastic resin in an acceleration voltage range of 100 to 300 keV, the irradiation is performed using the carbon fiber. Is performed on a laminated body sandwiched between thermoplastic resins, and the laminated body after electron beam irradiation is heated and combined. FIG. 2A shows a conceptual diagram of a specific example of the first aspect. In FIG. 2, EB means an electron beam, and CF means a carbon fiber.

  In addition, a laminate in which carbon fibers are sandwiched between thermoplastic resins is formed by arranging carbon fiber short fibers in a plane on a film or sheet-like thermoplastic resin and aligning the carbon fiber long fibers (filaments). It is obtained by arranging in a plane, or by arranging a woven fabric, knitted fabric or nonwoven fabric of carbon fiber, and placing another film or sheet-like thermoplastic resin on the carbon fiber.

  In the first aspect, as described above, the carbon fiber irradiated with the electron beam and the thermoplastic resin are combined by heating after the electron beam irradiation. That is, before irradiation with the electron beam, the carbon fiber and the thermoplastic resin are not heat-complexed. For example, the carbon fiber and the thermoplastic resin may exist separately. May exist as When carbon fiber and thermoplastic resin are present separately, electron beam irradiation may be different for carbon fiber and thermoplastic resin, or the same electron beam irradiation device may be used. Then, irradiation with an electron beam may be performed sequentially or simultaneously.

  FIG. 1 shows an example of an electron beam irradiation apparatus that can be used in the present invention. In the electron beam irradiation apparatus, a vacuum chamber 2 having a multi-electron gun 7 and a casing 1 to which carbon fiber and a thermoplastic resin are supplied are installed in a lower portion thereof, and the vacuum chamber 2 and the casing 1 are in contact with each other. It is configured as follows. The interior of the housing 1 is maintained in an inert gas atmosphere such as nitrogen gas, and a conveyor 5 suspended from the driving roll 3 and the driven roll 4 is disposed. A sample 6 is conveyed on the conveyor 5. A multi-electron gun 7 serving as a cathode is disposed in the vacuum chamber 2, and a window 8 serving as an anode is formed of a titanium film at a position below the vacuum chamber 2 and in contact with the housing 1. Since the electron beam is irradiated from the multi-electron gun 7 in the vacuum chamber 2 toward the sample 6 in the housing 1 through the window 8, the inside of the housing 1 constitutes the process region 9.

The sample 6 is an object irradiated with an electron beam, and specifically includes a laminate in which the above-described carbon fiber is sandwiched between thermoplastic resins, carbon fiber, and a thermoplastic resin.
Moreover, when using a laminated body as the sample 6, when the thickness of a laminated body increases, generally an electron beam does not fully enter into an inside, Therefore It is preferable that the thickness of a laminated body is 100-270 micrometers. In addition, when manufacturing a thick molded body as a carbon fiber reinforced resin molded body, after preparing a plurality of laminates having a thickness in the above range and performing electron beam irradiation on each laminate, It is preferable to stack and integrate.

Here, the electron beam dose D (MGy) is a relational expression between I (Irradiation current (mA)), S (Conveyor speed (m / min.)), And n (Number of Irradiation) (the following formula 1). Is calculated from

D = 0.216 × (I / S) × n (Formula 1)
When an acceleration voltage (V) is 170 keV, a nylon-6 film having a thickness of 25 μm, and a carbon fiber having a diameter of 6 μm are used, the electron beam penetrates to a depth of 100 to 270 μm. In consideration of the depth of penetration, it is necessary to appropriately control the density and thickness of the material used, the irradiation environment, and the like.

  There is no particular limitation on the apparatus used when performing the heat compounding as long as the carbon fiber and the thermoplastic resin irradiated with the electron beam can be heated and pressurized. For example, the heating and pressing apparatus shown in FIG. 3 is used. .

In the heating and pressurizing apparatus shown in FIG. 3, a molding container 28 is installed between two heaters 25. In the molding container 28, an inert gas such as nitrogen is used to keep the atmosphere inside the container in a non-oxidized state. In addition, an intake port 26 and an exhaust port 27 for supplying argon and an argon-hydrogen mixed gas are provided. A pressurizer 24 is disposed inside the molding container 28, and can pressurize the carbon fibers 21 and the thermoplastic resin 22 sandwiched between the heat insulating plates 23. In the first aspect, the carbon fiber 21 and the thermoplastic resin 22 are carbon fiber and thermoplastic resin irradiated with an electron beam, but in the second aspect described later, the electron beam is irradiated. Previous carbon fibers and thermoplastic resins are used.

  In addition to the heating and pressurizing apparatus shown in FIG. 3, for example, a laminated body made of carbon fiber and a thermoplastic resin in a heated state is used as an apparatus used when performing heat-combination. It is also possible to use a device having a function of integrating by passing it through.

  In the first embodiment, the heat compounding is performed after irradiating the carbon fiber and the thermoplastic resin with an electron beam. However, if the carbon fiber and the thermoplastic resin are left standing for a long time after the electron beam irradiation, the mechanical property of the carbon fiber reinforced thermoplastic resin molded body is obtained. Strength improvement effect is reduced. For this reason, it is preferable to heat-combine the carbon fiber and the thermoplastic resin immediately after irradiation with the electron beam. Specifically, the carbon fiber and the thermoplastic resin are heat-combined within 10 minutes after the electron beam irradiation. Is preferred.

(Second embodiment)
The second aspect of the method for producing a carbon fiber reinforced thermoplastic resin molding of the present invention is a carbon fiber reinforced thermoplastic resin molding in which an acceleration voltage is in the range of 100 to 300 keV and the carbon fiber and the thermoplastic resin are irradiated with an electron beam. In the method for producing a body, before the irradiation, the carbon fiber and the thermoplastic resin are combined by heating.

In a 2nd aspect, it is preferable that the electron beam irradiation dose in the said irradiation is the range of 0.1-0.5MGy, and it is more preferable that it is the range of 0.2-0.4MGy.
When the electron beam irradiation dose is in the above range, the obtained carbon fiber reinforced thermoplastic resin molded article has the conventional mechanical properties such as tensile strength, bending strength, and impact strength, and other conventional carbon fiber reinforced thermoplastic resin molded articles. It is preferable because it improves compared with the above.

  As a specific example of the second aspect, in the method for producing a carbon fiber reinforced thermoplastic resin molded body in which an electron beam is irradiated to the carbon fiber and the thermoplastic resin in an acceleration voltage range of 100 to 300 keV, the irradiation is performed using the carbon fiber. The method performed to the composite_body | complex obtained by heat-combining the laminated body which pinched | interposed with the thermoplastic resin is mentioned. FIG. 2B shows a conceptual diagram of a specific example of the second aspect.

In addition, the laminated body which pinched | interposed the carbon fiber with the thermoplastic resin can use the thing similar to the laminated body described in the above-mentioned 1st aspect.
In the second embodiment, the composite is obtained by heat-combining the laminate, but as an apparatus used for heat-combining, carbon fiber and thermoplastic resin can be heated and pressurized. There is no limitation in particular, For example, the heating-pressing apparatus shown in FIG. 3 described in the 1st aspect mentioned above is used.

  In the second aspect, as described above, the composite is irradiated with the electron beam, but the electron beam irradiation apparatus used for the electron beam irradiation is not particularly limited. For example, the figure described in the first aspect described above. 1 or the like can be used. In the second embodiment, the complex is used as the sample 6.

  In the second aspect, a composite obtained by heat-combining carbon fiber and a thermoplastic resin is used. As the composite, other than the composite obtained by heat-combining the above-mentioned laminate. A molded product obtained by mixing a thermoplastic resin and carbon fibers (preferably short fibers) and molding the mixture into a desired shape by injection molding or extrusion molding may be used as a composite.

  In addition, when the thickness of a composite increases, generally an electron beam does not fully penetrate into the inside, so that the thickness of the composite is preferably 100 to 270 μm. In addition, when manufacturing a thick molded body as a carbon fiber reinforced resin molded body, it is preferable to laminate a plurality of composites having a thickness in the above range after performing electron beam irradiation. .

In the above-described method for producing a carbon fiber thermoplastic resin molded body, various secondary moldings such as vacuum molding and pressure molding may be added to the integrated composite.
The carbon fiber reinforced thermoplastic resin molding of the present invention can be obtained by the above-described method for producing a carbon fiber reinforced thermoplastic resin. The carbon fiber reinforced thermoplastic resin molding of the present invention is excellent in mechanical strength. For this reason, the carbon fiber reinforced thermoplastic resin molding of the present invention can be used as products, machine parts, and the like in various industrial fields such as aircraft, space rockets, automobiles, transportation equipment, sports equipment, and civil engineering and construction equipment.

EXAMPLES Next, although an Example is shown and this invention is demonstrated further in detail, this invention is not limited by these.
[Example 1]
Polyamide film (nylon-6, EMBLEM ON made by Unitika, thickness 25 μm, width 15.
0 mm, length 30.0 mm) and unidirectional carbon fiber bundle (hereinafter also referred to as carbon fiber) (Toray T-800HB, diameter 6 μm, length 40.0 mm, number 12,000, thickness about 115 μm, The surface is treated with a sizing agent).

A carbon fiber was sandwiched between two polyamide films to obtain a laminate. Next, using the heating and pressurizing apparatus described in FIG. 3, the laminated body is pressed under the conditions of a temperature of 230 ° C., an applied pressure of 4.4 kPa, a time of 2 minutes, and an atmosphere of Ar—H ₂ gas to perform heating and compounding. Polyamide layer /
Three layers comprising a carbon fiber layer / polyamide layer were integrated. During the heat-combination, a polyamide resin was mixed between the carbon fibers to obtain a film-like composite having a length of 23.8 mm, a width of 10.2 mm, a thickness of 150 μm, and a volume of 36.4 mm ³ . At this time, unnecessary carbon fiber portions protruding from both ends were excised. The carbon fiber content of this composite was 23.3% by volume.

Next, the composite was set in the electron beam irradiation apparatus shown in FIG. 1 and irradiated with an electron beam at room temperature in a nitrogen gas atmosphere (1013 hPa) to form a film-like carbon fiber reinforced thermoplastic resin molding (1-1). Got. The irradiation conditions are as follows: Acceleration voltage is 170 keV, Irradiation current is I = 2 mA, Conveyor speed is S = 10 m / min, the vacuum degree of the vacuum chamber is 3 × 10 ⁻⁴ Pa or less, and the thickness of the Ti foil window is The distance from the window to the sample was 10 mm, the voltage applied to the sample was about 130 keV, the irradiation dose per time was 43.2 kGy, and the irradiation time per time was 0.23 seconds. The number of irradiations was 7, the irradiation time was 1.61 seconds, and the irradiation amount was 0.30 MGy.

  The carbon fiber reinforced thermoplastic resin molded body (1-1) was subjected to a tensile test according to JIS K7073. That is, using an Instron tensile tester (model number 3367), using a strip-shaped test piece having a thickness of 150 μm, a width of 10.2 mm, a length of 23.8 mm, and a carbon fiber content of 23.3 vol%, the following formula The tensile strength is calculated, and the relationship between tensile stress and elongation strain is shown in FIG.

σ = F / S
(Σ: tensile strength (MPa), F: tensile load (N), S: cross-sectional area of test piece (m ² ))
In addition, a film-like composite having a thickness of 249 μm, a width of 1.93 mm, a length of 24.0 mm, a weight of 0.01 g, and a carbon fiber content of 43.6% by volume was obtained in the same manner as described above. The composite was irradiated with an electron beam to obtain a carbon fiber reinforced thermoplastic resin molding (1-2). The same apparatus was used for the electron beam irradiation, and the irradiation conditions of the electron beam were 10 times, the irradiation time was 2.3 seconds, and the irradiation dose was 0.43 MGy. In the heat compounding step, a slight gap was formed in the test piece, so that it became thicker than planned.

A bending test of the carbon fiber reinforced thermoplastic resin molded body (1-2) was performed according to JIS K7074. That is, using a three-point bending tester, using a test piece having a thickness of 249 μm, a width of 1.93 mm, a length of 24.0 mm, a weight of 0.01 g, and a carbon fiber content of 43.6% by volume, the distance between fulcrums A bending test was performed under the condition of 9.5 mm, bending strength was calculated according to the following formula, and the relationship between bending stress and bending strain is shown in FIG.

σ = 3PL / (2bh ² )
(Σ: bending strength (MPa), P: bending load (N), L: distance between gauges (m), b: width of test piece (m), h: distance between spans (m))
[Example 2]
A polyamide film similar to that in Example 1 and carbon fiber were prepared.

A carbon fiber was sandwiched between two polyamide films to obtain a laminate.
Next, the laminate was set in the electron beam irradiation apparatus shown in FIG. 1 and irradiated with an electron beam at room temperature in a nitrogen gas atmosphere (1013 hPa). Irradiation conditions are Acceleration voltage 170 keV, Irradiation current I = 2 mA, Conveyor speed S = 10 m
/ Min. The vacuum degree of the vacuum chamber is 3 × 10 ⁻⁴ Pa or less, the thickness of the Ti foil window is 15 μm, the distance from the window to the sample is 10 mm, the voltage applied to the sample is about 130 keV, and the irradiation amount per time is The irradiation time per irradiation was 0.23 seconds at 43.2 kGy. The number of irradiations was 10, the irradiation time was 2.3 seconds, and the irradiation amount was 0.432 MGy.

Next, using the heating and pressurizing apparatus described in FIG. 3, heating is performed by pressing the laminate after electron beam irradiation under the conditions of a temperature of 230 ° C., an applied pressure of 4.4 kPa, a time of 2 minutes, and an atmosphere of Ar—H ₂ gas. performs composite polyamide layer / carbon fiber layer / polyamide layer 3 layers of is firmly integrated, length 23.8 mm, width 10.2 mm, thickness 150 [mu] m, a volume 36.4 mm ³ filmy carbon A fiber-reinforced thermoplastic resin molding (2-1) was obtained. At this time, unnecessary carbon fiber portions protruding from both ends were excised. The carbon fiber content of this carbon fiber reinforced thermoplastic resin molding (2-1) was 23.3% by volume.

In the same manner as in Example 1, a tensile test of the carbon fiber reinforced thermoplastic resin molded body (2-1) was performed according to JIS K7073.
Also, by irradiating the laminated body with an electron beam and performing heating composite in the same manner as described above, the thickness is 249 μm, the width is 1.93 mm, the length is 24.0 mm, the weight is 0.01 g, and the carbon fiber is contained. A carbon fiber reinforced thermoplastic resin molding (2-2) having a rate of 43.6% by volume was obtained. The same apparatus was used for the electron beam irradiation, and the irradiation conditions of the electron beam were 10 times, the irradiation time was 2.3 seconds, and the irradiation dose was 0.43 MGy.

In the same manner as in Example 1, a bending test of the carbon fiber reinforced thermoplastic resin molded body (2-2) was performed according to JIS K7074.
The results are shown in FIGS.

[Comparative Example 1]
A test piece was prepared from the same film-like laminate as in Example 1 without irradiating an electron beam, and a tensile test based on JIS K7073 and a bending test based on JIS K7074 were performed.

The results are shown in FIGS.
From Comparative Example 1 and Examples 1 and 2, compared to the case where the electron beam was not irradiated (Comparative Example 1), the carbon fiber reinforced thermoplastic resin molded body obtained by irradiating the electron beam (Example 1, 2) was found to have high tensile strength and high flexural modulus.

[Comparative Example 2]
A polyamide film similar to that in Example 1 and carbon fiber were prepared.
The carbon fiber was irradiated with an electron beam. Irradiation conditions are Acceleration voltage 1
70 keV, Irradiation current is I = 2 mA, Conveyor speed is S = 10 m / mi
n. The vacuum degree of the vacuum chamber is 3 × 10 ⁻⁴ Pa or less, the thickness of the Ti foil window is 15 μm, the distance from the window to the sample is 10 mm, the voltage applied to the sample is about 130 keV, and the irradiation amount per time is 4
At 3.2 kGy, the irradiation time per time was 0.23 seconds. The number of irradiations was 7, the irradiation time was 1.6 seconds, and the irradiation amount was 0.302 MGy.

A carbon fiber-irradiated carbon fiber was sandwiched between two polyamide films to obtain a laminate. Next, using the heating and pressurizing apparatus described in FIG. 3, the laminated body is pressed under the conditions of a temperature of 230 ° C., an applied pressure of 4.4 kPa, a time of 2 minutes, and an atmosphere of Ar—H ₂ gas to perform heating and compounding.
A film-like carbon fiber having a thickness of 150 μm, a width of 10.2 mm, a length of 23.8 mm, and a carbon fiber content of 23.3% by volume, in which three layers of polyamide layer / carbon fiber layer / polyamide layer are firmly integrated. A reinforced thermoplastic resin molding (c2-1) was obtained. In the same manner, a film-like carbon fiber reinforced thermoplastic resin molding (c2-) having a thickness of 249 μm, a width of 1.93 mm, a length of 24.0 mm, a weight of 0.01 g, and a carbon fiber content of 43.6% by volume. 2) was obtained. At this time, unnecessary carbon fiber portions protruding from both ends were excised.

In the same manner as in Example 1, the tensile test of the carbon fiber reinforced thermoplastic resin molded body (c2-1) was conducted according to JIS.
Performed in accordance with K7073.
In the same manner as in Example 1, the bending test of the carbon fiber reinforced thermoplastic resin molded body (c2-2) was performed according to JIS K7074.

The results are shown in FIGS.
As in Comparative Example 2, the carbon fiber reinforced thermoplastic resin moldings obtained by irradiating only the carbon fiber with the electron beam and not irradiating the thermoplastic resin with the electron beam were obtained in Example 1 and Example 2. The tensile strength and flexural modulus were inferior compared with the carbon fiber reinforced thermoplastic resin molding obtained in 1.

[Comparative Example 3, Examples 3, 4, 5, Reference Example 1]
In Example 1, the number of electron beam irradiations was 0 (Comparative Example 3), 3 (Example 3), 7 (Example 4), 10 (Example 5), 15 (Reference Example 1) times, and the irradiation dose was 0. (Comparative Example 3), 0.130 (Example 3), 0.302 (Example 4), 0.432 (Example 5), 0.648 (Reference Example 1) MGy, irradiation time 0 (Comparative Example) 3), 0.69 (Example 3), 1.61 (Example 4), 2.30 (Example 5), 3.45 (Reference Example 1) It carried out similarly and the carbon fiber reinforced thermoplastic resin molding was obtained.

  A test piece was prepared from a carbon fiber reinforced thermoplastic resin molding in the same manner as in Example 1, a tensile test based on JIS K7073 was performed, and the relationship between tensile strength and electron beam irradiation amount is shown in FIG. 8 (solid line).

[Examples 6, 7, 8, 9, 10]
In Example 2, the number of electron beam irradiations was 3 (Example 6), 7 (Example 7), 10 (Example 8), 15 (Example 9), 20 (Example 10) times, and the irradiation dose was 0. .130 (Example 6), 0.302 (Example 7), 0.432 (Example 8), 0.648 (Example 9), 0.86
4 (Example 10) MGy, irradiation time 0.69 (Example 6), 1.61 (Example 7), 2.30 (Example 8), 3.45 (Example 9), 4.60 (Example 10) A carbon fiber reinforced thermoplastic resin molding was obtained in the same manner as in Example 2 except that the time was changed to seconds.

  A test piece was prepared from a carbon fiber reinforced thermoplastic resin molded body in the same manner as in Example 2, a tensile test based on JIS K7073 was performed, and the relationship between tensile strength and electron beam irradiation amount is shown in FIG. 8 (dotted line).

Example 11
Using the same carbon fiber bundle as in Example 1, 2,000 of the carbon fiber bundles (12,000) were counted and adjusted to 10,000, and the carbon fiber content was 45. Except having changed to 5 volume%, it carried out like Example 1 and obtained the carbon fiber reinforced thermoplastic resin molding.

A test piece was prepared from a carbon fiber reinforced thermoplastic resin molded body in the same manner as in Example 1, a tensile test based on JIS K7073 was performed, and the result is shown in FIG.
The shape of the test piece was 45.5 vol% carbon fiber content: 10,000 carbon fibers, 323 μm thick, 4.55 mm wide, and 30.5 mm long.

[Comparative Example 4]
In Example 11, a test piece having a carbon fiber content of 45.5% by volume was prepared in the same manner as in Example 11 except that no electron beam irradiation was performed, and a tensile test based on JIS K7073 was performed. It is shown in FIG.

  From the comparative example 4 and Example 11, it turned out that the carbon fiber reinforced thermoplastic resin molding obtained by irradiating an electron beam has high tensile strength compared with the case where irradiation of an electron beam is not performed.

It is the schematic which shows an example of an electron beam irradiation apparatus. It is a conceptual diagram (a) which shows the specific example of the 1st aspect of the manufacturing method of a carbon fiber reinforced thermoplastic resin molding, and the conceptual diagram which shows the specific example of a 2nd aspect. It is the schematic which shows an example of the heating-pressing apparatus for heat-combining a thermoplastic resin and carbon fiber. It is a figure which shows the relationship between the tensile stress and the elongation distortion in the carbon fiber reinforced thermoplastic resin molding of Example 1 and Comparative Examples 1 and 2. It is a figure which shows the relationship between the bending stress in the carbon fiber reinforced thermoplastic resin molding of Example 1, and Comparative Examples 1 and 2, and a bending distortion. It is a figure which shows the relationship between the tensile stress and the elongation distortion in the carbon fiber reinforced thermoplastic resin molding of Example 2 and Comparative Examples 1 and 2. It is a figure which shows the relationship between the bending stress in the carbon fiber reinforced thermoplastic resin molding of Example 2, and Comparative Examples 1 and 2, and a bending distortion. It is a figure which shows the relationship between the tensile stress of the carbon fiber reinforced thermoplastic resin molding of Examples 3-10, the comparative example 3, and the reference example 1, and an electron beam irradiation amount. It is a figure which shows the relationship between the tensile stress and the elongation distortion of the carbon fiber reinforced thermoplastic resin molding of Example 11 and Comparative Example 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Housing 2 ... Vacuum chamber 3 ... Drive roll 4 ... Follower roll 5 ... Conveyor 6 ... Sample 7 ... Multi electron gun (cathode)
8 ... Window (Anode)
DESCRIPTION OF SYMBOLS 9 ... Process area 21 ... Carbon fiber 22 ... Thermoplastic resin 23 ... Insulation board 24 ... Pressurizer 25 ... Heater 26 ... Intake port 27 ... Exhaust port 28 ... Molded containers

Claims (6)

  A method for producing a carbon fiber reinforced thermoplastic resin molded article, comprising irradiating an electron beam to a carbon fiber and a thermoplastic resin in an acceleration voltage range of 100 to 300 keV.   2. The method for producing a carbon fiber reinforced thermoplastic resin molded article according to claim 1, wherein after the irradiation, the carbon fiber irradiated with the electron beam and the thermoplastic resin are combined by heating.   The method for producing a carbon fiber-reinforced thermoplastic resin molded article according to claim 2, wherein an electron beam irradiation dose in the irradiation is in a range of 0.1 to 0.9MGy.   The method for producing a molded article of carbon fiber reinforced thermoplastic resin according to claim 1, wherein the carbon fiber and the thermoplastic resin are combined by heating before the irradiation.   The method for producing a carbon fiber-reinforced thermoplastic resin molded article according to claim 4, wherein an electron beam irradiation dose in the irradiation is in a range of 0.1 to 0.5 MGy.   A carbon fiber reinforced thermoplastic resin molded article obtained by the production method according to claim 1.

Images