JP6748974B2 - Molding material, molded body, bicycle, manufacturing method of molded body - Google Patents

Description

The present disclosure relates generally to molding materials, moldings, bicycles, and methods of making the moldings. The present disclosure specifically relates to a molding material containing a thermoplastic resin and carbon fibers, a molded body made of this molding material, a method of manufacturing a molded body using this molding material, and a bicycle including the molded body. ..

Conventionally, it has been performed to improve the rigidity of a molded body by blending a resin material with carbon fiber. Generally, a resin-made molded product whose rigidity is reinforced with carbon fibers is called a carbon fiber reinforced thermoplastic (CFRTP: Carbon Fiber Reinforced Thermo Plastics). For example, Patent Document 1 discloses a molding material containing carbon fiber and polypropylene.

JP, 2017-075290, A

If the adhesion between the carbon fiber and the resin is insufficient, the rigidity of the molded product may not be sufficiently improved.

An object of the present disclosure is to provide a molding material capable of obtaining a molding having excellent rigidity, a molding made of the molding material, a method of manufacturing the molding using the molding material, and a bicycle including the molding. To provide.

A molding material according to an aspect of the present disclosure includes a first thermoplastic resin, a carbon fiber, and a second thermoplastic resin different from the first thermoplastic resin, the second thermoplastic resin, It is attached to carbon fiber.

A molded body according to an aspect of the present disclosure includes a first thermoplastic resin, carbon fibers dispersed in the first thermoplastic resin, and a second thermoplastic resin different from the first thermoplastic resin. The second thermoplastic resin is present in at least a part of the interface between the first thermoplastic resin and the carbon fiber.

A bicycle according to an aspect of the present disclosure includes the molded body and a bicycle body to which the molded body is attached.

In the method for manufacturing a molded body according to an aspect of the present disclosure, the molding material is injection molded, compression molded, extruded, or blow molded.

According to the molding material according to one aspect of the present disclosure, a molded body having excellent rigidity can be obtained. The molded body according to one aspect of the present disclosure has excellent rigidity. A bicycle according to an aspect of the present disclosure includes a molded body having excellent rigidity. According to the method for manufacturing a molded body according to one aspect of the present disclosure, a molded body having excellent rigidity can be obtained.

FIG. 1 is an enlarged view of a main part of an example of a molded body according to an embodiment of the present disclosure. FIG. 2 is a schematic side view showing an example of a bicycle according to an embodiment of the present disclosure.

1. Overview A molding material (hereinafter, also referred to as a molding material (X)) according to an embodiment of the present disclosure includes a first thermoplastic resin (hereinafter, also referred to as a first thermoplastic resin (A)) and a carbon fiber (hereinafter, It also includes a carbon fiber (B) and a second thermoplastic resin different from the first thermoplastic resin (A) (hereinafter, also referred to as the second thermoplastic resin (C)). The second thermoplastic resin (C) is attached to the carbon fiber (B).

When a molding material containing only the first thermoplastic resin (A) and the carbon fiber (B) is molded, the adhesion between the first thermoplastic resin (A) and the carbon fiber (B) may be insufficient. In that case, the rigidity of the molded body could not be sufficiently improved. If the compounding amount of the carbon fiber (B) is increased in order to increase the rigidity of the molded body, the weight of the molded body will increase.

On the other hand, the molded body 100 obtained by molding the molding material (X) of the present embodiment has the first thermoplastic resin (A) and the carbon fibers (dispersed in the first thermoplastic resin (A) ( B) and a second thermoplastic resin (C) different from the first thermoplastic resin (A). In the molded body 100, the second thermoplastic resin (C) is present in at least a part of the interface between the first thermoplastic resin (A) and the carbon fiber (B). Thereby, the adhesiveness between the first thermoplastic resin (A) and the carbon fibers (B) can be improved, and excellent rigidity can be imparted to the molded body 100.

2. Details Hereinafter, the molding material, the method for manufacturing the molded body, the molded body, and the bicycle according to the present embodiment will be described in detail.

2-1. Molding Material The molding material (X) contains the first thermoplastic resin (A), the second thermoplastic resin (B), and the carbon fiber (C) as described above. The molding material (X) may further contain a component (D) other than the first thermoplastic resin (A), the second thermoplastic resin (B) and the carbon fiber (C). These configurations will be described in detail.

(1) First Thermoplastic Resin The first thermoplastic resin (A) is the main component of the molding material (X) and is used in known molding methods such as injection molding, compression molding, extrusion molding and blow molding. , A known resin can be included. In this embodiment, the first thermoplastic resin (A) preferably contains an olefin resin (A1).

The olefin resin (A1) may include, for example, one or more materials selected from the group consisting of polyethylene, polypropylene, and polybutadiene. Examples of polyethylene include low density polyethylene (LDPE), medium density polyethylene, high density polyethylene (HDPE), homopolymers of ethylene, copolymers of ethylene and α-olefins, and the like. Polyethylene can include one or more of these materials. Examples of polypropylene include homopolymers of propylene (homopolypropylene), random copolymers containing propylene (random polypropylene), block copolymers containing propylene (block propylene), isotactic polypropylene, syndiotactic polypropylene and the like. Polypropylene can include one or more of these materials. The ratio of the olefin resin (A1) to the first thermoplastic resin (A) is preferably 80% by weight or more, preferably 90% by weight or more, and also preferably 100% by weight. That is, the first thermoplastic resin (A) may be an olefin resin (A1).

The olefin resin (A1) preferably contains polypropylene. In this case, the moldability of the molding material (X) can be improved, and the molding material (X) is particularly easy to apply to injection molding.

The material contained in the olefin resin (A1) may be modified with a resin modifier. For example, the material contained in the olefin resin (A1) is preferably acid-modified. That is, it is preferable that the first thermoplastic resin (A) contains an acid-modified olefin resin (A10). The acid-modified olefin resin (A10) has a functional group introduced by a resin modifier. By the interaction between this functional group and the second thermoplastic resin (C), the adhesion between the first thermoplastic resin (A) and the carbon fiber (B) can be improved, and the rigidity of the molded body 100 can be improved. Can be improved. Moreover, since the amount of carbon fibers (B) used can be reduced, the weight of the molded body 100 can be reduced.

The acid-modified olefin resin (A10) is obtained by modifying (reacting) the material contained in the olefin resin (A1) with a resin modifier. The resin modifier is not particularly limited, but preferably contains, for example, a polyvalent carboxylic acid anhydride. As described above, since the olefin resin (A1) preferably contains polypropylene, the acid-modified olefin resin (A10) preferably contains polycarboxylic acid anhydride-modified polypropyne. In this case, the adhesion between the first thermoplastic resin (A) and the carbon fiber (B) can be further improved, and the dispersibility of the carbon fiber (B) in the first thermoplastic resin (A) can be improved. Can be improved. Therefore, the rigidity of the molded body 100 can be particularly improved. Examples of polycarboxylic acid anhydrides include succinic anhydride, phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, maleic anhydride, dichloromaleic anhydride, itaconic anhydride, tetrabromophthalic anhydride, and anhydrous. Pyromellitic acid and the like are included. The resin modifier can include one or more of these materials. In particular, the resin modifier preferably contains maleic anhydride. That is, the acid-modified olefin-based resin (A10) preferably contains maleic anhydride-modified polypropylene. In this case, the adhesion between the first thermoplastic resin (A) and the carbon fiber (B) can be particularly improved, and the dispersibility of the carbon fiber (B) in the first thermoplastic resin (A) can be particularly improved. Can be improved. Thereby, the rigidity of the molded body 100 can be particularly improved. The ratio of the acid-modified olefin resin (A10) to the olefin resin (A1) in the first thermoplastic resin (A) is preferably 0.3% by weight or more, and more preferably 10% by weight or less. In this case, the rigidity of the molded body 100 can be improved, and the amount of the carbon fibers (B) used can be reduced, so that the molded body 100 can be made lighter.

The first thermoplastic resin (A) may contain an antioxidant, a colorant, a permanent filler, an ultraviolet absorber, a recycled material and the like.

(2) Carbon fiber (B)
The carbon fiber (B) may include a known carbon fiber mixed with a molding material. The carbon fibers (B) can include, for example, acrylonitrile-based carbon fibers or pitch-based carbon fibers.

The fiber diameter of the carbon fiber (B) is not particularly limited, but is preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 20 μm or less. In this case, it is easy to ensure the moldability of the molding material (X) and the rigidity of the molded body 1 made from the molding material (X).

The lower limit of the fiber length of the carbon fiber (B) is not particularly limited, but is preferably 0.1 mm or more, for example. In this case, the rigidity of the molded body 1 made of the molding material (X) can be easily improved. The upper limit of the fiber length of the carbon fiber (B) is not particularly limited, but is preferably 800 mm or less, for example. In this case, it is easy to ensure the moldability of the molding material (X). When the molding material (X) is applied to injection molding, the fiber length of the carbon fiber (B) is preferably 20 mm or less. In this case, the molding material (X) can be easily molded by injection molding.

(3) Second thermoplastic resin (C)
The second thermoplastic resin (C) of this embodiment is attached to the carbon fibers (B). The second thermoplastic resin (C) is preferably impregnated in the carbon fiber (B). Further, the second thermoplastic resin (C) may be filled in a plurality of fibers constituting the carbon fiber (B). For example, the carbon fibers (B) impregnated with the second thermoplastic resin (C) may be formed into pellets. In this case, the carbon fibers (B) are easily dispersed in the first thermoplastic resin (A), and the rigidity of the molded body 100 is easily improved. A commercially available product may be used as the pellet of the carbon fiber (B) impregnated with the second thermoplastic resin (C). As such a commercially available product, for example, Carbocom KB chip manufactured by Komatsu Matere Co., Ltd. may be mentioned.

The second thermoplastic resin (C) is a thermoplastic resin different from the first thermoplastic resin (A). As described above, since the first thermoplastic resin (A) contains the olefin resin (A1), the second thermoplastic resin (C) preferably contains the non-olefin resin (C1).

The non-olefin resin (C1) preferably contains a resin having thermoplasticity other than the olefin resin (A1). The non-olefin resin (C1) may include, for example, one or more materials selected from the group consisting of thermoplastic epoxy resin, acrylic resin, polyester resin, polyamide resin, polycarbonate resin, and ABS resin.

When the elastic moduli of the cured product of the second thermoplastic resin (C) and the cured product of the first thermoplastic resin (A) are compared, it is preferable that the relationship of the following formula (1) is satisfied.

That is, the molding material (X) preferably satisfies the above formula (1). In this way, the second thermoplastic resin (C) having a higher elastic modulus than the cured product of the first thermoplastic resin (A) is interposed at the interface between the first thermoplastic resin (A) and the carbon fiber (B). As a result, buckling of the carbon fiber (B) during the molding of the molding material (X) can be suppressed, and the stress generated during molding of the molding material (X) can be dispersed in the fiber direction of the carbon fiber (B). it can.

In this embodiment, the non-olefin resin (C1) preferably contains a thermoplastic epoxy resin. In this case, the adhesiveness between the first thermoplastic resin (A) and the carbon fiber (B) can be particularly improved, and the rigidity of the molded product made from the molding material (X) can be particularly improved. The thermoplastic epoxy resin is an epoxy resin having thermoplasticity even after curing, and is a linear high molecular weight epoxy polymer. For this reason, it is preferable that the thermoplastic epoxy resin is a resin whose form can be changed by treatment such as heating and pressurization after curing. The thermoplastic epoxy resin is obtained, for example, by chain extension of a bifunctional epoxy compound and a bifunctional phenol compound by an addition polymerization reaction involving ring opening of an epoxy ring.

In particular, when the first thermoplastic resin (A) contains a polyvalent carboxylic acid anhydride-modified polypropylene, in the molded body 100, the polyvalent polyhydric acid is present between the first thermoplastic resin (A) and the carbon fiber (B). There are functional groups introduced by carboxylic acid anhydrides and thermoplastic epoxy resins. Due to the interaction between this functional group and the thermoplastic epoxy resin, the adhesion between the first thermoplastic resin (A) and the carbon fiber (B) can be particularly improved, whereby the rigidity of the molded body 100 is particularly improved. Can be made. In addition, the blending amount of carbon fiber (B) can be reduced.

In the molding material (X) of this embodiment, the second thermoplastic resin (C) is attached to the carbon fiber (B), and more specifically, the second thermoplastic resin (C) is the carbon fiber (B). Is impregnated in. The volume ratio of the carbon fiber (B) to the volume of the second thermoplastic resin (C) impregnated in the carbon fiber (B) is preferably 20% or more and 80% or less, and 40% or more and 70% or less. And is preferably 50% or more and 60% or less. In this case, it is easy to secure the moldability of the molding material (X) while improving the rigidity of the molded body 100.

The ratio of the carbon fiber (B) to which the second thermoplastic resin (C) is attached to the total amount of the molding material (X) is preferably 5% by weight or more, and more preferably 7% by weight or more. In this case, the rigidity of the molded body 100 made of the molding material (X) can be sufficiently ensured. The ratio of the carbon fibers (B) to the total amount of the molding material (X) is preferably 75% by weight or less, more preferably 50% by weight or less, further preferably 25% by weight or less, and 15% by weight. % Or less is particularly preferable. In this case, it is possible to secure the rigidity of the molded body 100 while securing the moldability of the molding material (X). Particularly when the molding material (X) is injection-molded, the proportion of the carbon fiber (B) to which the second thermoplastic resin (C) is attached is preferably 15% by weight or less with respect to the total amount of the molding material (X). In this case, the strength (weld strength) of the portion where the melted molding materials join together can be improved.

The second thermoplastic resin (C) may contain a lubricant. In particular, when the second thermoplastic resin (C) contains a lubricant, the ratio of the lubricant to the total amount of the second thermoplastic resin (C) is preferably 0.02% by weight or less, and 0.01% by weight or less. It is preferable. In this case, it is possible to suppress whitening on the surface of the molded body 100 made of the molding material (X).

(4) Component (D)
As described above, the molding material (X) may contain the component (D) other than the first thermoplastic resin (A), the carbon fiber (B), and the second thermoplastic resin (C). Examples of the component (D) include colorants, dyes, UV absorbers, foaming agents, other thermoplastic resins, and the like.

(5) Preparation of molding material The molding material (X) is, for example, the first thermoplastic resin (A), the carbon fiber (B) impregnated with the second thermoplastic resin (C), and optionally a component. It can be prepared by dry blending with (D).

2-2. Molded Body Manufacturing Method As described above, the molded body 100 of the present embodiment can be manufactured by molding the molding material (X). The molding method of the molding material (X) includes methods such as injection molding, compression molding, extrusion molding and blow molding. Therefore, in the method for manufacturing the molded body 1, the molding material (X) is injection molded, compression molded, extruded, or blow molded. Thereby, the molded body 1 can be produced from the molding material (X).

2-3. Molded Product FIG. 1 is an enlarged view of a main part of a molded product 100 obtained by molding the molding material (X) of the present embodiment. As shown in FIG. 1, the molded body 100 includes a resin region 101, a carbon fiber portion 102, and an interface portion 103. The resin region 101 is formed of the first thermoplastic resin (A) contained in the molding material (X). Further, the carbon fiber portions 102 are dispersed in the resin region 101. The carbon fiber portion 102 is derived from the carbon fiber (B) contained in the molding material (X). Therefore, in the molded body 100, the carbon fibers (B) are dispersed in the first thermoplastic resin (A). The interface portion 103 is an interface portion between the resin region 101 and the carbon fiber portion 102. At least a part of the interface portion 103 is formed of the second thermoplastic resin (C) contained in the molding material (X). Therefore, in the molded body 100, the second thermoplastic resin (C) is present in at least a part of the interface portion 103 between the first thermoplastic resin (A) and the carbon fiber (B). The second thermoplastic resin (C) present in the interface portion 103 can improve the adhesion between the first thermoplastic resin (A) and the carbon fiber (B). Thereby, the rigidity of the molded body 100 can be improved. In particular, when the first thermoplastic resin (A) contains the acid-modified olefin resin (A10) modified with the above resin modifier, the second thermoplastic resin (C) and the acid-modified olefin resin ( The functional group of A10) can particularly improve the adhesion between the first thermoplastic resin (A) and the carbon fiber (B). The presence of the second thermoplastic resin (C) in the molded body 100 can be confirmed by an apparatus such as SEM or FT-IR.

Further, in the molded body 100, it is preferable that the carbon fiber portion 102 is covered with the interface portion 103 made of the second thermoplastic resin (C). That is, it is preferable that the carbon fiber (B) is covered with the second thermoplastic resin (C). In this case, the adhesion between the first thermoplastic resin (A) and the carbon fiber (B) can be particularly improved, and the rigidity of the molded body 100 can be particularly improved. Of course, in the molded body 100, there may be a portion where the carbon fiber (B) is not covered with the second thermoplastic resin (C).

In the molded body 100, the thickness of the interface portion 103 formed of the second thermoplastic resin (C) is not particularly limited, but is preferably 10 μm or more, and preferably 5 mm or less.

In the molded body 100 shown in FIG. 1, the carbon fibers (B) are dispersed in the first thermoplastic resin (A), and the carbon fibers (B) are not exposed on the surface of the molded body 100. Not limited to. For example, a part of the carbon fibers (B) may be exposed on the surface of the molded body 100.

The usage of the molded body 100 is not particularly limited as long as it is a field in which a resin molded body is used. The molded body 100 is preferably, for example, a bicycle component. In this case, examples of the bicycle parts include a basket, a chain case, a mudguard, and a child seat. By manufacturing these bicycle parts from the molded body 100, it is possible to obtain a bicycle part having excellent rigidity and reduce the weight of the bicycle part.

The molded body 100 is not limited to bicycle parts, and may be applied to, for example, a shopping basket, a distribution pallet, a home electric appliance, an automobile part or the like.

2-4. Bicycle The bicycle 200 shown in FIG. 2 includes a bicycle body 210, a basket 211, a chain case 212, a mudguard 213, and a child seat 214.

The bicycle main body 210 is a known bicycle, and includes, for example, a frame, wheels, saddles, handles, cranks, chains, brakes, and the like. Since the bicycle body 210 shown in FIG. 2 is an electrically assisted bicycle, it may further include a battery, a motor, and the like.

The basket 211, the chain case 212, the mudguard 213, and the child seat 214 are bicycle parts, and are attached to the bicycle body 210. In this embodiment, for example, the basket 211 is preferably the molded body 100. Further, for example, the chain case 212 is preferably the molded body 100. Further, for example, the mudguard 213 is preferably the molded body 100. Further, for example, the child seat 214 is preferably the molded body 100. That is, the bicycle 200 of this embodiment includes the molded body 100 and the bicycle body 210 to which the molded body 100 is attached.

In the bicycle 200 according to the present embodiment, the bicycle 200 such as the basket 211, the chain case 212, the mudguard 213, and the child seat 214 is configured with the molded body 100, so that the bicycle 200 can be easily reduced in weight.

(Examples 1-12, Comparative Examples 1-2)
The components shown in Table 1 were dry blended in the proportions shown in Table 1 to prepare the molding materials of Examples 1-15 and Comparative Examples 1-2. Details of the components shown in Table 1 are as follows.
-Polypropylene resin: Sumitomo Chemical Co., Ltd., trade name Block-PP AW564
-Acid-modified olefin resin: Maleic anhydride-modified polypropylene resin-Thermoplastic resin-impregnated carbon fiber: Thermoplastic epoxy resin-impregnated carbon fiber (trade name CABOKOMA KB chip manufactured by Komatsu Matere Co., Ltd.)
Molded articles were produced by injection molding the molding materials of Examples 1-12 and Comparative Examples 1-2. The following evaluations were performed on the molded articles of Examples 1-12 and Comparative Examples 1-2.

(Evaluation)
(1) Tensile Elastic Modulus From the molded products of Examples 1 to 12 and Comparative Examples 1 and 2, test pieces having a length of 165 mm (80 mm in the finest part), a thickness of 10 mm, and a thickness of 2.8 mm were produced. Using this test piece, the tensile modulus specified by JIS K 7161-1 was measured using a tensile tester (Autograph load cell 2kN manufactured by Shimadzu Corporation). The results are shown in Table 1.

(2) Tensile Strength of Weld Part From the molded products of Examples 1 to 12 and Comparative Example 1, the merging part (weld part) of the molten molding material was positioned so that the length was 165 mm (80 mm in the finest part), and the thick part was thick. A test piece having a size of 10 mm and a thickness of 2.8 mm was prepared. Using this test piece, the tensile strength specified by JIS K 7161-1 was measured using a tensile tester (Autograph load cell 2kN manufactured by Shimadzu Corporation). The results are shown in Table 1.

(3) Tensile Strength From the molded products of Examples 1 to 12 and Comparative Examples 1 and 2, test pieces having a length of 165 mm (80 mm in the finest part), a thickness of 10 mm, and a thickness of 2.8 mm were produced. Using this test piece, the tensile strength specified by JIS K 7161-1 was measured using a tensile tester (Autograph load cell 2kN manufactured by Shimadzu Corporation). The results are shown in Table 1.

100 molded body

Claims (12)

A first thermoplastic resin,
A thermoplastic resin-impregnated carbon fiber separate from the first thermoplastic resin ,
The thermoplastic resin-impregnated carbon fiber includes a second thermoplastic resin different from the first thermoplastic resin, and carbon fiber,
The carbon fiber is composed of a plurality of fibers ,
The second thermoplastic resin contains a thermoplastic epoxy resin, and is impregnated in the carbon fiber ,
Molding material. The thermoplastic resin-impregnated carbon fiber is formed into a pellet shape ,
The molding material according to claim 1. The first thermoplastic resin and the thermoplastic resin-impregnated carbon fiber are dry blended ,
The molding material according to claim 1 . Satisfies the following formula (1),
The molding material according to claim 1.
Elastic modulus of cured product of first thermoplastic resin ≤ Elastic modulus of cured product of second thermoplastic resin (1) The first thermoplastic resin contains an acid-modified olefin resin,
The molding material according to any one of claims 1 to 4 . The acid-modified olefin-based resin includes a polycarboxylic acid anhydride-modified polypropylene resin,
The molding material according to claim 5 . A molded body obtained from the molding material according to any one of claims 1 to 6,
The second thermoplastic resin is present in at least a part of the interface between the first thermoplastic resin and the carbon fiber ,
Molded body. At least a part of the carbon fiber is covered with the second thermoplastic resin,
The molded product according to claim 7 . The second thermoplastic resin is present in the interface portion in the entire circumference of at least a part of the carbon fiber,
The molded product according to claim 7 . It is a bicycle part,
The molded product according to any one of claims 7 to 9 . A molded article according to any one of claims 7 to 10,
A bicycle body to which the molded body is attached,
bicycle. A molding material containing a first thermoplastic resin and a thermoplastic resin-impregnated carbon fiber which is separate from the first thermoplastic resin is prepared by injection molding, compression molding, extrusion molding or blow molding. A method of manufacturing a molded body to be molded, comprising:
The thermoplastic resin-impregnated carbon fiber includes a second thermoplastic resin different from the first thermoplastic resin, and carbon fiber,
The carbon fiber is composed of a plurality of fibers ,
The second thermoplastic resin contains a thermoplastic epoxy resin, and is impregnated in the carbon fiber,
Method for producing molded body.

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