JP6892572B2 - Method for manufacturing injection foam molded product of carbon fiber reinforced / modified polyester resin - Google Patents

Description

The present invention relates to providing a method for producing a foam molded product of a thermoplastic carbon fiber reinforced / modified polyester resin by an injection molding method.

Examples of the thermoplastic polyester include polyethylene terephthalate (hereinafter referred to as PET or pet), polybutylene terephthalate (PBT), polycarbonate (PC) and the like as aromatic saturated polyesters. These have excellent physical properties such as transparency, mechanical strength, and rigidity as thermoplastic resins, and are widely used as fibers, films, plastics, and the like. In particular, in the plastics field, molded products are widely used in bottles, sheets, containers, daily necessities, automobile interior materials, mechanical parts, electrical / electronic materials, building materials, earth and wood, various industrial products, and the like.
In addition, these polyesters are used for higher-grade applications because various properties such as mechanical strength and heat resistance are dramatically improved by further mixing glass fibers or carbon fibers to form a thermoplastic composite material. Has been coming. In particular, since glass fiber is inexpensive, a large amount of GF-PET composite material, GF-PBT composite material, and GF-PC composite material reinforced by the glass fiber are used. On the other hand, carbon fibers have high strength but are so expensive that these CF-polyester composites have been used in small quantities for special purposes.

In recent years, in advanced industrial fields such as civil engineering / construction, high-rise buildings, automobile industry, Shinkansen train industry, linear motor car, and aerospace industry, further weight reduction and energy saving by improving mechanical strength of constituent materials. In addition, further performance improvements such as corrosion resistance, electrical characteristics, heat resistance, and heat dissipation are required.
Generally, if the molecular weight of a synthetic resin is increased, the moldability and physical properties are improved. However, inexpensive PET-based polyesters (PET and PBT) are difficult to obtain, for example, a high molecular weight compound of 50,000 or more due to the polycondensation method, and are candy-like in a molten state. It is extremely difficult to stably produce an extruded molded product by the horizontal extrusion method, particularly an extruded foam molded product and a high-strength injection foamed molded product. In addition, the solid-layer polymerization method in which the medium molecular weight of this inexpensive PET-based polyester is doubled in molecular weight requires several hours, so that the productivity is low. In addition, there was a weakness that required a large-scale manufacturing facility for the petrochemical complex.

As shown in Patent Document 1, Patent Document 2 and Patent Document 3, the present inventors have adopted a reaction extrusion method for a medium molecular weight material having a carboxyl group at the terminal with these inexpensive PET-based polyesters, and have adopted an epoxy resin. Achieves high productivity in which polyesters are reacted with each other to increase the molecular weight in a short time of several minutes or less by using a system binder (also called a chain extender or thickener) and a catalyst, and compact and inexpensive equipment is used. A production method by a reaction extrusion method is provided. However, although there have been epoch-making advances in molding processability due to an increase in the melt tension of polyester, the effects initially expected for improvement in mechanical properties have hardly been observed.
Further, as shown in Patent Documents 4 and 5, the present inventor is an inexpensive new carbon fiber made of polyethylene terephthalate (PET) and recovered carbon fiber or thick-count PAN rayon as a raw material, 6 mm long (ZOLTEK). (Manufactured by the company) ・ Using 15 and 30% by weight of 6 mm length, carbon fiber reinforced by reacting with a twin-screw extruder in the presence of an epoxy resin-based binder (chain extender) and a catalyst by a reaction extrusion method. The modified pet resin is used, and their mechanical strength is significantly improved from about 2.9 times to about 3.5 times in tensile strength and from about 5.7 times to about 10 times in bending elasticity. Further, in Patent Document 6, the present inventor succeeded in producing a flat plate and an extruded foam plate by a T-die extrusion method using ZOLTEK carbon fiber reinforced / modified pet resin in the same manner.

Public Notice No. 3503952 International release WO2009 / 00745 A1 Registered as US 8258239B2 JP 2015-007215 JP 2016-157939 WO2016 / 117861

Further weight reduction by improving the mechanical strength of constituent materials in advanced industrial fields such as civil engineering / construction, high-rise buildings, small flying objects (drones), automobile industry, Shinkansen train industry, liner motor car, and aerospace industry. -In addition to energy saving, further performance improvements such as corrosion resistance, conductivity, heat resistance, and heat dissipation are required. In particular, an object of the present invention is to produce a device for an industrial flying object (drone), a camera, a container for storing a battery, an automobile engine cover, etc. at high speed by injection foam molding. The purpose is to develop applications such as weight reduction materials for high-rise buildings, high-strength / corrosion-resistant materials for coastal highways, corrosion-resistant / high-strength materials for marine structures, and corrosion-resistant materials for surface flying boats.

Means to try to solve the problem

An object of the present invention is to provide a lightweight new foam molded product by injecting and foaming a carbon fiber reinforced / modified PET resin having improved strength at a high speed. That is, the present invention manufactures an injection-foamed molded product of a carbon fiber-reinforced / modified polyester resin, which comprises adding a foaming agent to a carbon fiber-reinforced / modified PET-based polyester resin and foaming it by an injection molding method. It provides a method.

The present invention provides the following manufacturing method in more detail.
The present invention is firstly an injection molding method in which a foaming agent is added to a carbon fiber reinforced / modified polyester resin having a melt flow rate of 1-40 g / 10 minutes by the JIS method K7210 (260 ° C., load 2.16 kg). The present invention provides a method for producing an injection-foamed molded product of a carbon fiber-reinforced / modified polyester resin, which is characterized by being foamed in.

The present invention secondly provides a method for producing an injection foam molded product of a carbon fiber reinforced / modified polyester resin, which is characterized in that the injection molding method is a core back type.

Thirdly, the present invention is a foamed molded product of a carbon fiber reinforced / modified polyester resin, wherein the foaming agent is a volatile foaming agent and is a supercritical fluid inert gas nitrogen gas and / or carbon dioxide gas. It provides a manufacturing method of.

Fourthly, the present invention is a method for producing a foamed molded product of a carbon fiber reinforced / modified polyester resin, wherein the foaming agent is a volatile foaming agent and is an inert gas such as carbon dioxide gas and / or nitrogen gas. Is to provide.

Fifth, the present invention provides a method for producing a foamed molded product of a carbon fiber reinforced / modified polyester resin, wherein the foaming agent is a heat-decomposable foaming agent.

The present invention provides a method for producing a foamed molded product of carbon fiber reinforced / modified polyester resin, which is characterized in that the foaming agent is a microcapsule containing a hydrocarbon compound having a low boiling point. is there.

Effect of the invention

The present inventors have succeeded in producing a foam plate by a horizontal extrusion method according to Patent Document 6. However, in order to manufacture a specific shape such as an industrial flying object (drone) device, a camera, a container for storing a battery, an engine cover of an automobile, etc., the foam plate is heat-molded again into the specific shape. Must be cut.
According to the present invention, it is possible to produce a drone device, a camera, a container for storing a battery, and an engine cover having a complicated shape at a high speed by using a male and female mold of an injection foam molded product having a specific shape.
In the present invention, chopped products such as cheap new carbon fiber by the large tow method, carbon fiber recovered from less-rolled bobbins from the cheaper aircraft industry, and recycled carbon fiber from carbon fiber reinforced composite material (CFRP) of aircraft scraps are produced. It can be suitably used as a raw material. Therefore, it is possible to reduce the cost of the injection foam molded product.

Hereinafter, the present invention will be described in detail.
The carbon fiber reinforced / modified polyester resin used in the present invention has a melt flow rate of 1-40 g / 10 minutes according to the JIS method K7210 (260 ° C., load 2.16 kg), and 100 weight of polyester as the component (A). Parts, 5 to 150 parts by weight of carbon fiber of component (B), 0.1 to 2 parts by weight of polyfunctional epoxy compound containing two or more epoxy groups in the molecule as a binder of component (C), (D). ) The composition composed of 0.01 to 1 part by weight of the binding reaction catalyst of the components is produced by heating at a temperature equal to or higher than the melting point of the polyester.
[Polyester of component (A)]
The polyester of the component (A) as the main raw material in the present invention is an aromatic saturated polyester.
Specific examples of this series of polyesters include polyethylene terephthalate (PET), low melting point PET obtained by copolymerizing a small amount of isoftal acid, a copolymer of ethylene glycol, cyclohexanedimethanol and terephthalic acid (PETG), and polytetramethylene terephthalate (poly). Butylene terephthalate, PBT), polyethylene-2,6-naphthalate (PEN) and the like can be mentioned. Polybutylene terephthalate (PBT) is preferred. Polyethylene terephthalate (PET), which is mass-produced and extremely inexpensive , can be used satisfactorily.

[Carbon fiber of component (B)]
The carbon fiber of the component (B) in the present invention preferably has an oxygen-containing functional group, particularly a carboxyl group, on its surface. As the carbon fiber, it is preferable to use a PAN-based industrial product as the first series. For example, an inexpensive carbon fiber chop manufactured by ZOLTEK of the United States (6 mm length of the rattan (LT) PAN-based carbon fiber "Panex35" of ZOLTEK of the United States) is particularly preferable. Toray Industries, Inc.'s high-performance carbon fiber "Trading Card" T500, T600, T700 series for aircraft can also be used. In addition, industrial cut fiber T008 series, T010 series, TS12-006 (cut length 3-12 mm), or "Trading card" milled fiber MLD series (fiber length 30-150 μm) can also be used as raw materials. Further, in general, these carbon fiber industrial products have a relatively large content of carboxyl groups.
As the second series, industrial products of pitch-based carbon fiber of Kureha Corporation and Osaka Gas Chemical Co., Ltd. can also be used. These have a relatively high content of functional groups, but their strength is rather low. Since it has the advantage of isotropic property in the strength of the molded product, it can be preferably used.

As the carbon fiber of the component (B) of the present invention, the regenerated carbon fiber recovered from the carbon fiber reinforced thermosetting epoxy resin composite material (CFRP) can be preferably used as the third series. Carbon fiber reinforced thermosetting epoxy resin composite material (CFRP), which is the raw material, is currently about 40% by-product when assembling an aircraft, drill chips that are by-produced when boring, fishing rods, golf Obtained from tees, etc. In the future, it is expected to be derived in large quantities from CFRP scrap, which accounts for about 65% of large aircraft.
In addition, the bobbin-wound long fiber cut fiber (cut length 3-12 mm), which is collected as an odd product at the time of manufacturing an aircraft body, is of good quality and extremely inexpensive, so that it can be used satisfactorily.
As illustrated in Production Example 1 of the example, the regenerated carbon fiber is subjected to electrolytic oxidation treatment under the control of reaction conditions according to the method of Professor Sugiyama of Hachinohe National College of Technology, and a large number of carboxyl groups are introduced. Can be used particularly preferably. The amount of carboxyl groups of the regenerated carbon fiber of the present invention usually contains the range of 0.01-0.20 mmol / g. The range that can be preferably used is 0.02-0.15 mmol / g.
The fiber length of recycled carbon fiber depends on the size of CFRP scraps such as aircraft and the size of chips generated by boring during assembly. In the present invention, the fiber length is referred to as long fiber (100 mm or more), medium fiber (3-100 mm) or powdered fiber (3 mm or less). Both can be preferably used in the present invention.

[Binder of component (C)]
The binder of the component (C) of the present invention preferably has a weight average molecular weight of 1,000 to 300,000, and is a polymer-type polyfunctional epoxy compound containing 2 to 100 epoxy groups in the molecule. Can be used alone or as a mixture of two or more types. Commercially available products such as those in which a glycidyl group containing an epoxy ring is hung in a pendant shape from a resin forming a high molecular weight skeleton or those containing an epoxy group in the molecule, for example, NOF Corporation's "Marproof" series, BASF Japan Co., Ltd.'s "John Krill ADR" series can be used.

[Combination reaction catalyst of component (D)]
The binding reaction catalyst as the component (D) in the present invention consists of (1) alkali metal organic acid salts, carbonates and bicarbonates, and (2) alkaline earth metal organic acid salts, carbonates and bicarbonates. It is a catalyst containing at least one kind selected from the above group. As the organic acid salt, a carboxylate salt, an acetate salt and the like can be used, and among the carboxylates, stearate salt is particularly preferable. As the metal forming the metal salt of the carboxylic acid, alkali metals such as lithium, sodium and potassium; alkaline earth metals such as magnesium, calcium, strontium and barium can be used.

In the present invention, the spreading agent can be effectively used, but it is particularly effective when the polyester of the component (A) and the carbon fiber of the component (B) are powders. Usually, paraffin oil, liquid paraffin, trimethylsilane and the like can be used. Liquid paraffin is particularly preferred because it is non-polar, has a high boiling point and is a moderately sticky fluid. The amount added is 0.01-1 part by weight with respect to the component (A). These spreading agents are necessary for uniformly adhering the carbon fibers of the component (B) to the pellets or powders of the polyester of the component (A), and the carbon fibers / powder soar into the atmosphere and the human body or the like. It is an indispensable auxiliary agent to prevent adverse effects on electrical instrumentation equipment.

As the foaming agent of the present invention, a conventionally known foaming agent can be used. For example, as the volatile foaming agent, carbon dioxide gas and / or nitrogen gas, which are inert gases, can be used. They do not cause fires and do not require explosion-proof equipment, so they can be operated in small and medium-sized enterprise town factories. Suitable for industrial production of the low foaming ratio foam of the present invention. In particular, in the injection foam molding of the present invention, it is effective to use a supercritical fluid of nitrogen gas and / or carbon dioxide gas for densification of bubbles and homogenization of the molded product. Further, the supercritical nitrogen gas improves the dimensional accuracy of the molded product as compared with the supercritical carbon dioxide gas.
As the foaming agent of the present invention, a heat-decomposable foaming agent can be used. Since the melting point of polyester resin exceeds 200 ° C, there are few chemical substances that can actually be used. A baking soda-based foaming agent used for low foaming of polypropylene can be used. However, since water vapor is generated, short-term equipment maintenance is required for foam molding of polyester resin, which is easily hydrolyzed.
It is difficult to use low boiling point hydrocarbon compounds such as flopan, butane, and hexane as they are. These are used in microencapsulation or in the form of a masterbatch of polyolefin substrate.

Next, the present invention will be described in detail based on examples. The evaluation method for the polyester and the polyester-carbon fiber composite material of the present invention is as follows.
(1) Method for measuring intrinsic viscosity (IV value) of PET, etc. Using a mixed solvent of equal weight of 1,1,2,2-tetrachloroethane and phenol, measurement was performed at 25 ° C. with a Canon Fuensuke viscometer. Alternatively, the manufacturer's catalog value was adopted.
(2) Measurement method of melt flow rate (MFR) According to the condition 20 of JIS K7210 (ISO 1133 ASTM D1238), the measurement was performed under the conditions of a temperature of 280 ° C., a temperature of 260 ° C., and a load of 2.16 kg. However, the resin used was previously dried with hot air or vacuum at 120 ° C. × 12 hours or 140 ° C. × 4 hours.
(3) Measurement method of specific gravity It was also measured by the dimensional measurement method of JIS K7222. Alternatively, alcohol was measured as a liquid for the resin pellets or small pieces of the molded product according to the method A (underwater substitution method) of JIS K7112.
(4) Method for measuring mechanical strength A 10 mm wide piece was cut out from an injection foam molded plate.
(ISO 20753, JIS K7139 multipurpose test piece type A1 type: total length 120 mm, thickness 4 mm, chuck width 20 mm, constriction width 10 mm)
Test piece shape: Bending test piece strip type 80 mm length x 10 mm width (thickness 4 mm)
Tensile test piece Strip type 100 mm length x 10 mm width (thickness 4 mm)
Bending test: The flexural modulus is calculated from linear regression of 0.05% and 0.25% of the strain interval (JIS K771). The evaluation was made with an average value of 3-5 points.
The bending strength was evaluated by performing 3-point bending at a test speed of 5 mm / min and using an average value of 3-5 points.
Tensile test: Tensile strength was evaluated at a test speed of 2 mm / min and an average value of 3-5 points.
Young's modulus was calculated by linear regression of 25% and 75% of the maximum load (JIS K7073 et al.).

A production example of the basic resin material according to the present invention is shown.

Manufacturing example 1

[Manufacture of ZOLTEK carbon fiber reinforced / modified pet resin pellet R1 consisting of pet resin, 15% carbon fiber chop and modifier]
100 parts by weight (water content after drying of about 100 ppm or less) of general-purpose pet resin pellets (bottle grade: Taiwan / South Asia 3802T, IV value 0.80) as polyester of component A and polyfunctional epoxy resin as a binder of component C 0.60 parts by weight, 0.16 parts by weight of the mixing catalyst for the binding reaction of the D component and 0.06 parts by weight of the liquid paraffin as the spreading agent of the E component were uniformly mixed with a super mixer. These were delivered to the first hopper for extrusion of the main resin. On the other hand, as the carbon fiber of component B, LT carbon fiber chop (PAN-based carbon fiber "Panex35" 6 mm long from Zoltek's rattan (LT) rayon in the United States) was delivered to the second hopper for the side feeder.
Using a biaxial extruder (diameter 60 mm, 1 vent type) manufactured by Toshiba Machine Co., Ltd., the set temperature of the cylinder and die consisting of 10 blocks of this extruder was set to 150-270 ° C and the screw rotation speed was 150 rpm. did. Using a heavy-duty weighing feeder, a mixed resin of A component, C component, D component, etc. is reacted and extruded from the first hopper at a rate of 100 kg / h, and a carbon fiber chop is 17.6 kg / h from the second hopper. Continuous side-feeding was performed at a rate of (carbon fiber content 15%).
The strands were continuously extruded into water from an obliquely downward nozzle having a diameter of 3 mm and cut with a rotary cutter to produce about 180 kg of black resin pellet R1. The strands from the mold outlet to the basin were linear and the melt tension increased. Its shape was columnar with a diameter of about 3.4 mm and a length of about 6 mm. The MFR (260 ° C., load 2.16 kg) was 6.2 g / 10 minutes.
The black pellet R1 of this carbon fiber reinforced / modified pet resin is dried with hot air at 120 ° C. overnight, and a hybrid injection molding machine FNZ60 (molding pressure 140 tons, screw diameter 60 mm) manufactured by Nissei Resin Industry Co., Ltd. is used. The following injection molded article was molded under the conditions of a molding temperature of 280 ° C., a mold temperature of 130-145 ° C., an injection pressure of 53 MPa, an injection speed of 12 mm / s, a screw rotation speed of 80 rpm, and a cooling time of 20 seconds.
Shape of multipurpose test piece: ISO 20753, JIS K7139 A1 type, total length 120 mm, thickness 4 mm, chuck width 20 mm, constriction width 10 mm,
The same length 80 mm (Z runner method)
The ZOLDEK carbon fiber (CF15%) reinforced / modified pet resin pellet R1 showed good injection moldability without burr by-products. The surface of the test piece was smooth and glossy. The test was carried out at a tensile speed of 2 mm / min and a bending speed of 5 mm / min. The physical characteristics of these pellets are shown in Table 1.
Compared with the transparent pellet P1 containing only the sticky resin of Production Example 8, the mixing effect of about 15% of ZOLDEK carbon fibers of this Example R1 is 2.9 times the tensile strength, 4.1 times the Young's modulus, and the bending strength. It has a flexural modulus of 3.5 times and a flexural modulus of 5.7 times.

Manufacturing example 2

[Manufacture of ZOLTEK carbon fiber reinforced / modified pet resin pellet R2 consisting of pet resin, carbon fiber chop 30% and modifier]
The pellet R2 was produced under substantially the same conditions as in Production Example 1 described above. However, the speed of the side feed was doubled in order to increase the content of carbon fiber chops to about 30%. 100 parts by weight (water content after drying of about 100 ppm or less) of general-purpose pet resin pellets (bottle grade: Taiwan / South Asia 3802T, IV value 0.80) as polyester of component A and polyfunctional epoxy resin as a binder of component C 0.56 parts by weight, 0.16 parts by weight of the mixing catalyst for the binding reaction of the D component and 0.06 parts by weight of the liquid paraffin as the spreading agent of the E component were uniformly mixed with a super mixer. These were delivered to the first hopper for extrusion of the main resin. On the other hand, as the carbon fiber of the B component, LT carbon fiber chop (6 mm long rattan PAN-based carbon fiber "Panex35" manufactured by ZOLDEK in the United States) was delivered to the second hopper for the side feeder.
A twin-screw extruder (diameter 60 mm, 1 vent type) in the same direction was used, and the set temperature of the cylinder and die consisting of 10 blocks of this extruder was set to 150-270 ° C. and the screw rotation speed was 150 rpm. Using a heavy-duty weighing feeder, a mixed resin of A component, C component, D component, etc. is reacted and extruded from the first hopper at a rate of 100 kg / h, and a carbon fiber chop is 42 kg / h (carbon) from the second hopper. Continuous side-feeding at a rate of fiber content (30%).
The strand was continuously extruded into water from an obliquely downward nozzle having a diameter of 3 mm and cut with a rotary cutter to produce about 250 kg of black resin pellet R2. The strands from the mold outlet to the basin were linear and the melt tension increased.
Its shape was columnar with a diameter of about 3.4 mm and a length of about 6 mm. The MFR (260 ° C., load 2.16 kg) was 6.7 g / 10 minutes. The carbon fiber (CF15%) reinforced / modified pet resin pellet R2 showed good injection moldability without burr by-products, and the surface of the test piece was almost smooth and glossy. The physical characteristics of these pellets are shown in Table 1. Compared with the transparent pellet P1 containing only PET resin in Production Example 8, the mixing effect of about 30% of ZOLDEK carbon fibers in Example R2 is 3.5 times the tensile strength, 6.1 times the Young's modulus, and 3. It was 9 times and the flexural modulus was 10.3 times. A carbon fiber reinforced / modified pet resin pellet having good injection moldability and improved mechanical strength was obtained.

Manufacturing example 3

[Manufacture of pellet P1 using only pet resin]
Using only 100 parts by weight (3 kg) of PET resin of component A (pellets of commercially available general-purpose products for PET bottles: IV value 0.80, MFR 35 g / 10 minutes, 280 ° C., 2.16 kg), and Production Examples 4 and 5. Repellet P1 was produced under almost the same extrusion conditions to obtain 2.9 kg of transparent pellets. The strands drooped from the mold outlet to the water surface and meandered in the basin, indicating that the melt tension was small. The transparent pellet P1 was columnar and had a diameter of about 3 mm and a length of about 5 mm. The MFR (280 ° C., load 2.16 kg) was 57 g / 10 minutes, and the melt viscosity was relatively low.
The pellet P1 containing only PET resin was injection-molded to form a tensile test piece and a bending test piece in the same manner as in Production Examples 1 and 2. The tensile strength was 59 MPa, the Young's modulus was 1.9 GPa, the bending strength was 84 MPa, and the flexural modulus was 2.1 GPa.

Example 1-3

[Manufacture of injection flat plate A and injection foam plate B1-B2 from supercritical nitrogen gas from ZOLTEK (30%) carbon fiber reinforced / modified pet resin pellet R2]
A flat plate mold (inner dimension 360 mm × 250 mm, thickness 4 mm, volume 360 cc) was installed in a microcellular form (MuCell) injection molding device (450 tons) of The Japan Steel Works, Ltd.
(Example 1) Carbon fiber reinforced pet resin R2 (dried black pellet, specific gravity 1.45, MFR 6.7 g / 10 minutes: 260 ° C., load 2.16 kg) containing ZOLTEK carbon fiber (6 mm chop, 30%) 100 Injection molding was carried out at a cylinder temperature of 260-290 ° C., a mold temperature of 140-150 ° C., and a plate thickness of 4.0 mm by weight%. The produced flat plate A (36 cm × 25 cm, thickness 4 mm) had an average weight of 532 g, a specific gravity of 1.48, and no foaming. The flexural modulus of the test piece cut out from the resin injection portion in the flow direction (MD) of the carbon fiber was 14.6 GPa.
(Example 2) Under the same conditions, an injection foam (MuCell) having a resin filling rate of 80% was produced by injecting a predetermined amount of supercritical nitrogen gas. The average weight of the foamed flat plate B1 (36 cm × 25 cm, thickness 4 mm) was 432 g, the specific gravity was 1.19, and the foaming ratio was 1.24. The flexural modulus of the test piece cut out from the resin injection portion in the flow direction (MD) of the carbon fiber was 11.5 GPa.
(Example 3) Under the same conditions, an injection foam (MuCell) having a resin filling rate of 70% was produced by injecting a predetermined amount of supercritical nitrogen gas. The average weight of the foamed flat plate B2 (36 cm × 25 cm, thickness 4 mm) was 370 g, the specific gravity was 1.03, and the foaming magnification was 1.44. The flexural modulus of the test piece cut out from the injection portion of the tree finger in the flow direction (MD) of the carbon fiber was 10.1 GPa.

Example 4-5

[Manufacture of injection flat plate C1 and injection foam plate C2 by core back method using supercritical nitrogen gas from ZOLTEK (30%) carbon fiber reinforced / modified pet resin pellet R2]
(Example 4) The same apparatus as in Example 1 was used. A flat plate was manufactured by setting the thickness of the core-back type injection foam plate when it was not foamed to 2.7 mm. The produced flat plate C1 (36 cm × 25 cm, thickness 2.7 mm) had an average weight of 342 g, a specific gravity of 1.41, and no foaming.
(Example 5) The same apparatus as in Example 4 was used. The injection foam plate was manufactured by setting the thickness of the core back type injection foam plate at the time of foaming to 4.0 mm. The produced foamed flat plate C2 (36 cm × 25 cm, thickness 4.0 mm) had an average weight of 349 g, a specific gravity of 0.969, and a volume foaming ratio of 1.48. The flexural modulus of the test piece cut out from the resin injection portion in the flow direction (MD) of the carbon fiber was 9.20 GPa.

Example 6-13

[Manufacture of injection foam plate D1-D8 by core back method using supercritical nitrogen gas from ZOLTEK (30%) carbon fiber reinforced / modified pet resin pellet R2]
The core back type was continued.
(Example 6) Plate thickness 2.7 → 5.26 mm (D1): The foam plate weight was 348 g, the specific gravity was 0.421, and the volume foaming ratio was 1.95.
(Example 7) Plate thickness 2.7 → 6.20 mm (D2): The foam plate weight was 349 g, the specific gravity was 0.422, and the volume foaming ratio was 2.30.
(Example 8) Plate thickness 2.7 → 7.16 mm (D3): The foam plate weight was 347 g, the specific gravity was 0.363, and the volume foaming ratio was 2.65.
(Example 9) Plate thickness 2.7 → 8.10 mm (D4): The foam plate weight was 348 g, the specific gravity was 0.322, and the volume foaming ratio was 3.00.
(Example 10) Plate thickness 2.7 → 9.10 mm (D5): The foam plate weight was 346 g, the specific gravity was 0.285, and the volume foaming ratio was 3.37.
(Example 11) Plate thickness 2.7 → 10.1 mm (D6): The foam plate weight was 348 g, the specific gravity was 0.258, and the volume foaming ratio was 3.74.
(Example 12) Plate thickness 2.7 → 11.0 mm (D7): The foam plate weight was 348 g, the specific gravity was 0.237, and the volume foaming ratio was 4.07.
(Example 13) Plate thickness 2.7 → 12.7 mm (D8): The foam plate weight was 346 g, the specific gravity was 0.204, and the volume foaming ratio was 4.70.
In a series of core-back injection foaming tests (Example 9), foam molding is stable and bubbles are uniformly dispersed and good until the plate thickness is 2.7 → 8.10 mm (D4) and the foaming ratio is 3.37. Met. Compared with the existing nylon-glass fiber system, the product of the present invention had surprisingly good molding stability and excellent surface smoothness.

Examples 14-17

[Manufacture of injection flat plate E1 by core back type, foam plates E2 and E3 by chemical foaming agent, and injection foam plate E4 by microcapsules from carbon fiber reinforced / modified pet resin pellet R2 of ZOLTEK (30%)]
A flat plate mold (inner dimension 100 mm × 200 mm) was installed in an injection molding device (MD100X, 100 tons) of Niigata Machine Techno.
(Example 14) Carbon fiber reinforced pet resin R2 (dried black pellet, specific gravity 1.45, MFR 6.7 g / 10 minutes: 260 ° C., load 2.16 kg) containing ZOLTEK carbon fiber (6 mm chop, 30%) 100 Injection molding was carried out at a cylinder temperature of 260-300 ° C., a mold temperature of 70-80 ° C., and a plate thickness of 2.4 mm by weight%. The produced flat plate E1 (thickness 2.4 mm) had an average weight of 78.3 g, a specific gravity of 1.46, and no foaming. The releasability from the mold was good, and the surface smoothness was also good.
(Example 15) Under the same conditions, 3 parts by weight of a chemical foaming agent (manufactured by Eiwa Kasei Kogyo, Polyslen E16D, decomposition temperature 200 ° C., gas generation amount 190 ml / 5 g) was mixed to achieve a core back thickness of 2.4. → An injection foam plate was manufactured at 3.6 mm. The foamed flat plate E2 had an average weight of 76.2 g and a volume foaming ratio of 1.5. The releasability from the mold was good, and the surface smoothness was also good.
(Example 16) Under the same conditions, the chemical foaming agent (manufactured by Eiwa Kasei Kogyo, Polyslen EE204, decomposition temperature 240 ° C., gas generation amount 80 ml / 5 g) was changed to 5 parts by weight, and the core back thickness was changed to 2. An injection foam plate was manufactured from 4 to 3.6 mm. The foamed flat plate E3 had an average weight of 75.8 g and a volume foaming ratio of 1.5. The releasability from the mold was good, and the surface smoothness was also good.
(Example 17) Under the same conditions, 3 parts by weight of a microcapsule (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd., MBF2860PE, decomposition temperature 280 ° C., gas generation amount 190 ml / 5 g) was mixed, and the core back thickness was 2.4. → An injection foam plate was manufactured at 3.6 mm. The foamed flat plate E4 had an average weight of 77.1 g and a volume foaming ratio of 1.5.

According to the present invention, the injection foam of carbon fiber (30%) reinforced / modified pet resin having a flexural modulus exceeding 20 GPa, which is the highest in the world, is a supercritical flow gas, a chemical foaming agent and a microcapsule type foaming agent. Was easily produced at 1.2-3 times (specific gravity 1.2-0.48) by the supercritical flow gas foaming method and the core back method.
By strengthening the carbon fiber, the PET-based polyester resin was able to dramatically increase the mechanical strength, but this time, the weight was reduced by foaming. The present invention is a container for storing instruments, cameras, and batteries of an industrial flying object "drone", which is rapidly developing for the time being and indispensable for high strength and weight reduction, and an automobile that requires high strength and weight reduction and heat resistance and heat dissipation. Targets the engine cover of. Further, various physical properties such as corrosion resistance, heat resistance, heat transfer property, conductivity, oil resistance, and weather resistance can be improved. In addition, the cost can be reduced by using recovered carbon fiber, recycled carbon fiber from carbon fiber reinforced epoxy resin composite material, and inexpensive new carbon fiber strength.
In the future, we will target applications for civil engineering and building materials. In the near future, it will be targeted for further weight reduction and energy saving applications by improving the strength of interior materials and constituent materials in advanced industrial fields such as railroad vehicles, automobile industry, Shinkansen train industry, linear motor cars, and aerospace industry. To do. In addition, since it is possible to further improve the performance such as radio wave absorption, conductivity, heat resistance, and heat dissipation, the utility of this functional material field is great.

Claims (6)

(A) Ingredients Polyethylene terephthalate 100 parts by weight,
(B) Ingredients Carbon fiber 5 to 150 parts by weight,
(C) A polymer-type polyfunctional epoxy compound containing two or more epoxy groups in the molecule as a component binder, 0.1 to 2 parts by weight,
(D) A composition composed of 0.01 to 1 part by weight of a component binding reaction catalyst is heated and reacted at a temperature equal to or higher than the melting point of the polyethylene terephthalate, and is subjected to JIS method K7210 (260 ° C., load 2.16 kg). a melt flow rate of 1 to 40 g / 10 min at a carbon fiber reinforced-modified polyethylene terephthalate resin and then includes the step of foaming by injection molding method by adding a foaming agent to the resin,
The binding reaction catalyst is a carbon fiber reinforced / modified polyethylene terephthalate resin containing at least one selected from the group consisting of alkali metal stearate or alkaline earth metal stearate. A method for manufacturing an injection foam molded product. The method for producing an injection foam molded product of a carbon fiber reinforced / modified polyethylene terephthalate resin according to claim 1, wherein the injection molding method is a core back type. The carbon fiber reinforced / modified polyethylene terephthalate resin according to claim 1 or 2 , wherein the foaming agent is a volatile foaming agent and is a supercritical fluid inert gas nitrogen gas and / or carbon dioxide gas. A method for producing a foamed molded product. The foamed molded product of a carbon fiber reinforced / modified polyethylene terephthalate resin according to claim 1 or 2 , wherein the foaming agent is a volatile foaming agent and is an inert gas such as carbon dioxide gas and / or nitrogen gas. Manufacturing method. The method for producing a foamed molded product of a carbon fiber reinforced / modified polyethylene terephthalate resin according to claim 1 or 2 , wherein the foaming agent is a heat-decomposable foaming agent. The method for producing a foamed molded product of a carbon fiber reinforced / modified polyethylene terephthalate resin according to claim 1 or 2 , wherein the foaming agent is a microcapsule containing a hydrocarbon compound having a low boiling point.