Composite material

Abstract

A composite material (1) comprises a matrix resin (2), and glass fibers (3) and wollastonite (4) dispersed inside the matrix resin. The matrix resin is a PBT resin, a PP resin, or a PA resin. The composite material contains at least 1 wt% of each of the wollastonite and the glass fibers. In the composite material, when the content of the glass fibers is denoted as a wt%, the content of the wollastonite is denoted as b wt%, and the content of the matrix resin is denoted as 100-a-b wt%, the relationships of formulae 1-7 are satisfied.　Formula 1: a≥-0.5000b+27.5000(1≤b≤10) Formula 2: a≥0.0000b+22.5000(10<b≤15) Formula 3: a≥-0.3613b+27.9194(15<b≤30.5) Formula 4: a≥-0.0571b+18.6429(30.5<b≤34) Formula 5: a≥0.1429b+11.8429(34<b≤37.5) Formula 6: a≤-0.7413b+45.0000(1≤b<37.5) Formula 7: a>-3.6543b+30.0000(b>0)

Description

composite material

[0001] This invention relates to composite materials.

[0002] Resin compositions made from thermoplastic aromatic polyester resins are widely used in various industrial fields as materials with excellent mechanical properties, thermal properties, and chemical resistance. One method used to improve the rigidity of such resin compositions is to incorporate fibrous fillers such as glass fibers.

[0003] For example, Toray Industries, Inc.'s PBT resin, Toraycon® 1101G-30, has increased mechanical strength by adding 30% glass fiber to polybutylene terephthalate resin.

[0004] Furthermore, Patent Document 1 discloses a polybutylene terephthalate resin composition that suppresses the breakage of reinforcing fibers and allows for easy production of molded articles with high rigidity and high strength. Specifically, Patent Document 1 discloses a polybutylene terephthalate resin composition comprising 30 to 150 parts by weight of a molding material having at least the following components [A], [B], and [C], wherein component [C] is arranged in contact with a composite having components [A] and [B]. [A] is a reinforcing fiber bundle, [B] is a thermoplastic resin with a weight-average molecular weight of 200 to 50,000 and a melt viscosity lower than that of component [C], and [C] is a polyolefin resin with a weight-average molecular weight of 10,000 or more. Glass fibers are disclosed as the reinforcing fibers constituting the reinforcing fiber bundle.

[0005] Japanese Patent Publication No. 2012-46684

[0006] Polybutylene terephthalate resin compositions reinforced with fibrous fillers such as glass fibers, as described above, are used as materials for vehicle parts because they have excellent mechanical properties such as chemical resistance, fatigue characteristics, and rigidity. However, the carbon dioxide emission intensity of glass fibers is said to be about the same as that of polybutylene terephthalate resin made from petroleum. In other words, glass fibers are a material that emits a very large amount of carbon dioxide, a greenhouse gas. Therefore, there is a demand for composite materials that reduce carbon dioxide emissions.

[0007] This invention has been made in view of the problems of the prior art. The object of this invention is to provide a composite material that has excellent mechanical properties while reducing carbon dioxide emissions.

[0008] A composite material according to an aspect of the present invention comprises a matrix resin and glass fibers and wollastonite dispersed within the matrix resin. The matrix resin is a polybutylene terephthalate resin, a polypropylene resin, or a polyamide resin. The composite material contains 1% by weight or more of the glass fibers and the wollastonite, respectively. When the content of the glass fibers in the composite material is a% by weight, the content of the wollastonite is b% by weight, and the content of the matrix resin is 100-a-b% by weight, the following relationships of formulas 1 to 7 are satisfied. Equation 1: a ≥ -0.5000b + 27.5000 (where 1 ≤ b ≤ 10) Equation 2: a ≥ 0.0000b + 22.5000 (where 10 < b ≤ 15) Equation 3: a ≥ -0.3613b + 27.9194 (where 15 < b ≤ 30.5) Equation 4: a ≥ -0.0571b + 18.6429 (where 30.5 < b ≤ 34) Equation 5: a ≥ 0.1429b + 11.8429 (where 34 < b ≤ 37.5) Equation 6: a ≤ -0.7413b + 45.0000 (where 1 ≤ b < 37.5) Equation 7: a > -3.6543b + 30.0000 (where b > 0)

[0009] According to the present invention, it is possible to provide a composite material with excellent mechanical properties while reducing carbon dioxide emissions.

[0010] Figure 1 is a schematic diagram showing an example of the internal structure of the composite material according to this embodiment. Figure 2 is a triangular graph showing the relationship between the weight fractions (weight %) of polybutylene terephthalate resin, glass fiber, and wollastonite in the composite material according to this embodiment. Figure 3 is a graph showing the relationship between the weight fractions (weight %) of glass fiber and wollastonite in the composite material according to this embodiment.

[0011] The composite material according to this embodiment will be described in detail below with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from the actual ratios.

[0012] As mentioned above, the carbon dioxide emission intensity of glass fiber is considered to be about the same as that of petroleum-based polybutylene terephthalate resin, polypropylene resin, and polyamide resin. Specifically, the database below lists the greenhouse gases (GHGs) emitted throughout the entire lifecycle of goods and services (from raw material procurement to disposal or recycling) as CO2 emissions. ２ The data includes carbon footprint data expressed in terms of weight, converted to a volume. Furthermore, the database below shows that the GHG emissions from polybutylene terephthalate are 4.82E + 00 kg - CO2. ２ The unit is e / , and the GHG emissions from polypropylene are 1.49E + 00 kg - CO2. ２ The unit is e / , and the GHG emissions from polyamide (nylon 6) are 4.63E + 00 kg - CO2. ２ It is stated that the unit is e / . And the GHG emissions from glass fiber are 2.32E + 00 kg - CO ２ It is stated that the unit is e / unit. "Carbon Footprint System Pilot Project CO ２ Common Unit Conversion Database (Internet)<URL: https: / / s3-eu-west-1.amazonaws.com / static.bambooroll.jp / CO2kansanryo_db_ver4_jp_20120330.pdf> )

[0013] Thus, the carbon dioxide emission intensity of glass fiber is on the same order of magnitude as that of polybutylene terephthalate resin, polypropylene resin, and polyamide resin, and glass fiber is CO ２ It is a substance that emits large amounts of CO2. Therefore, CO2 in composite materials ２ To reduce emissions, it is necessary to reduce the amount of glass fiber added. However, simply reducing the amount of glass fiber would decrease the mechanical strength of the composite material. Therefore, in this embodiment, instead of reducing the amount of glass fiber added, wollastonite is added to the composite material to increase its mechanical strength.

[0014] As shown in Figure 1, the composite material 1 according to this embodiment comprises a matrix resin 2 and glass fibers 3 and wollastonite 4 dispersed within the matrix resin 2. In the composite material 1, the matrix resin 2 serves as the matrix, and glass fiber particles 3 and wollastonite particles 4 are highly dispersed within the matrix. The matrix resin 2 is a polybutylene terephthalate resin, a polypropylene resin, or a polyamide resin.

[0015] In the composite material 1 of this embodiment, polybutylene terephthalate resin (PBT resin) can be used as the matrix resin 2. PBT resin can be produced by polycondensing terephthalic acid or dimethyl terephthalate, which is the main raw material, with 1,4-butanediol. In this process, other dicarboxylic acid or diol components may be copolymerized as needed.

[0016] Other dicarboxylic acid components are not particularly limited and include, for example, aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-diphenoxyethanedicarboxylic acid, 4,4'-diphenylsulfondicarboxylic acid, and 2,6-naphthalenedicarboxylic acid; alicyclic dicarboxylic acids such as 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid; and aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, and sebacic acid.

[0017] Other diol components besides 1,4-butanediol are not particularly limited and include, for example, aliphatic diols such as ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, 1,3-propanediol, polytetramethylene ether glycol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, and 1,8-octanediol; alicyclic diols such as 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,1-cyclohexanedimethylol, and 1,4-cyclohexanedimethylol; and aromatic diols such as xylylene glycol.

[0018] The main raw material, terephthalic acid or dimethyl terephthalate, preferably accounts for 80 mol% or more of the total dicarboxylic acid components, and more preferably for 90 mol% or more. The main raw material, 1,4-butanediol, preferably accounts for 85 mol% or more of the total diol components, and more preferably for 90 mol% or more.

[0019] There are two methods for producing PBT resin: one involves a transesterification reaction between dimethyl terephthalate and 1,4-butanediol, and the other involves a direct esterification reaction between terephthalic acid and 1,4-butanediol. The direct esterification reaction using terephthalic acid and 1,4-butanediol as starting materials allows for the easy production of polybutylene terephthalate, which has a higher cooling crystallization temperature compared to the transesterification method. Furthermore, continuous polymerization minimizes the decrease in molecular weight, increase in terminal carboxyl groups, and increase in residual tetrahydrofuran during the time elapsed after removal from the reaction vessel, resulting in a high-quality resin.

[0020] In the composite material 1, polypropylene resin (PP resin) can be used as the matrix resin 2. The polypropylene resin may be a homopolymer of polypropylene, a random polypropylene obtained by copolymerizing ethylene with polypropylene, or a block polypropylene in which polyethylene is dispersed in the homopolypropylene. Also, in the composite material 1, polyamide resin (PA resin) can be used as the matrix resin 2. The polyamide resin may be polyamide 6 or polyamide 66.

[0021] As described above, the GHG emissions of the PP resin and the PA resin are approximate to those of the PBT resin. Further, all of the PP resin, the PA resin, and the PBT resin are crystalline resins, and their molding shrinkage rates are approximate. Therefore, even when the PP resin and the PA resin are used as the matrix resin 2, due to the effects of the glass fiber 3 and the wollastonite 4, a composite material excellent in mechanical properties can be obtained while reducing the carbon dioxide emissions.

[0022] In the composite material 1 of the present embodiment, the glass fiber 3 acts as a reinforcing material and is used to improve mechanical properties such as tensile strength and flexural modulus. The average fiber length of the glass fiber 3 is not particularly limited, but can be set to 200 μm to 300 μm. Also, the average fiber diameter of the glass fiber 3 is not particularly limited, but can be set to 5 μm to 25 μm. The fiber length and the fiber diameter of the glass fiber 3 can be measured by observing a cross section of the composite material 1 with an optical microscope or a scanning electron microscope (SEM). Further, as the glass fiber 3, glass fiber surface-treated with an organic treatment agent such as a silane coupling agent or an epoxy compound may be used.

[0023] In the composite material 1 of the present embodiment, particles of wollastonite 4 are added as a reinforcing material together with the glass fiber 3. Wollastonite 4 is a metasilicic acid mineral and is a triclinic compound represented by the chemical formula: CaSiO ３ and is a needle-shaped or fibrous particle, and by adding it to the resin, heat resistance, abrasion resistance, corrosion resistance, and mechanical strength can be enhanced. Further, the CO of wollastonite２ It is known that the emissions are less than 1 / 100 of those of the matrix resins 2 (PBT resin, PP resin, and PA resin) and glass fibers 3. Therefore, by incorporating wollastonite 4 into the composite material 1, the ratio of matrix resins 2 and glass fibers 3 in the composite material 1 can be reduced. As a result, the CO emissions of the entire composite material 1 are reduced. ２ Emissions can be reduced.

[0024] The average fiber diameter of wollastonite 4 is not particularly limited, but can be between 5 μm and 50 μm. Similarly, the average aspect ratio (fiber length:fiber diameter) of wollastonite 4 is not particularly limited, but can be between 3:1 and 25:1. The fiber length and fiber diameter of wollastonite 4 can be measured by observing a cross-section of the composite material 1 with an optical microscope or scanning electron microscope (SEM).

[0025] Wollastonite 4 may be surface-treated with a silane coupling agent. Because hydroxyl groups are present on the surface of wollastonite 4, the surface of wollastonite 4 may be hydrophilic. Therefore, it is preferable that wollastonite 4 be surface-treated with a silane coupling agent in order to improve the adhesion between the hydrophobic matrix resin 2 and wollastonite 4, and to further improve the dispersibility of wollastonite 4 in the matrix resin 2. By surface-treating wollastonite 4 with a silane coupling agent, the surface of wollastonite becomes hydrophobic, thereby improving its affinity with the matrix resin 2. As a result, the adhesion between the matrix resin 2 and wollastonite 4 is improved, and the dispersibility of wollastonite 4 in the matrix resin 2 can also be improved.

[0026] One method for surface-treating wollastonite 4 with a silane coupling agent is to mix wollastonite 4 with the silane coupling agent, thereby bonding the hydroxyl groups on the surface of the wollastonite with the silane coupling agent.

[0027] Thus, by surface-treating the wollastonite 4, the adhesive strength between the matrix resin 2 and the wollastonite 4 is improved. As a result, the wollastonite 4's effect as a reinforcing material is enhanced, and the overall strength of the composite material 1 can be increased.

[0028] The silane coupling agent is not particularly limited, but examples include methyltrimethoxysilane, tetramethoxysilane, methyltriethoxysilane, tetraethoxysilane, long-chain fluoroalkylsilane, vinyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, hexamethyldisilazane, 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyl Tildisiloxane, 3-methacryloxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, n-octyltriethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, 3-methacryloxypropyltriethoxysilane, 1,4-bis(3-triethoxysilylpropyl)tetrasulfide, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-(N-phenyl)aminopropyltrimethoxysilane, γ-isocyanatetopropyltriethoxysilane, ureidopropyltrialkoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, etc. can be used.

[0029] The composite material 1 of the present embodiment contains 1% by weight or more of glass fiber 3 and wollastonite 4 respectively. Further, in the composite material 1, when the content of the glass fiber 3 in the composite material 1 is a% by weight, the content of the wollastonite 4 is b% by weight, and the content of the matrix resin 2 is 100 - a - b% by weight, the following relationships of Formula 1 to Formula 7 are satisfied. Formula 1: a ≧ -0.5000b + 27.5000 (where in Formula 1, 1 ≦ b ≦ 10) Formula 2: a ≧ 0.0000b + 22.5000 (where in Formula 2, 10 < b ≦ 15) Formula 3: a ≧ -0.3613b + 27.9194 (where in Formula 3, 15 < b ≦ 30.5) Formula 4: a ≧ -0.0571b + 18.6429 (where in Formula 4, 30.5 < b ≦ 34) Formula 5: a ≧ 0.1429b + 11.8429 (where in Formula 5, 34 < b ≦ 37.5) Formula 6: a ≦ -0.7413b + 45.0000 (where in Formula 6, 1 ≦ b < 37.5) Formula 7: a > -3.6543b + 30.0000 (where in Formula 7, b > 0)

[0030] Figure 2 is a graph showing the relationship of the weight fractions (weight %) of the PBT resin which is the matrix resin 2, the glass fiber 3 and the wollastonite 4 in the composite material 1. In Figure 2, when the weight fraction of the glass fiber 3 is a% by weight and the weight fraction of the wollastonite 4 is b% by weight, the weight fraction of the PBT resin is 100 - a - b% by weight. And the colored range A in the graph of Figure 2 is the range represented by Formula 1 to Formula 6. Further, Figure 3 is a graph showing the relationship of the weight fractions (weight %) of the glass fiber and the wollastonite in the triangular graph of Figure 2. And the range B in the graph of Figure 3 is the range represented by Formula 1 to Formula 7.

[0031] As described above, the CO of wollastonite ２The discharge amount is significantly less than that of glass fiber, but it has a property that the function as a reinforcing material is inferior to that of glass fiber. However, as will be described later, the inventor has found that when the weight fractions of the PBT resin, glass fiber 3, and wollastonite 4 are within the range of symbol A in FIG. 2, the mechanical strength is equal to or higher than that of a conventional PBT resin composition in which 30% by weight of glass fiber is added. Specifically, within the range of symbol A, it has been found that the tensile strength, flexural strength, flexural modulus, flexural break deflection rate, Izod impact strength, and heat deflection temperature under load are equal to or higher than those of the conventional PBT resin composition. Furthermore, within the range of symbol B in FIG. 3, the tensile strength, flexural strength, flexural modulus, flexural break deflection rate, Izod impact strength, and heat deflection temperature under load are equal to or higher than those of the conventional PBT resin composition, and ２ it has been found that the discharge amount is less than that of the conventional PBT resin composition. Therefore, by satisfying the relationships of Formulas 1 to 7 for the content of glass fiber 3 and the content of wollastonite 4, ２ it is possible to obtain a composite material that has mechanical strength equal to or higher than that of the conventional PBT resin composition while reducing the CO

[0032] Note that in the composite material 1, the matrix resin is a polybutylene terephthalate resin, and further preferably contains 45.3 to 72% by weight of the polybutylene terephthalate resin, 16.7 to 44.3% by weight of glass fiber 3, and 1 to 37.5% by weight of wollastonite 4. This composite material 1 is within the range of symbol B in the graph of FIG. 3, and since the amount of glass fiber is less than that of the conventional PBT resin composition to which 30% by weight of glass fiber is added, ２ the CO discharge amount can be reduced. Also, since this composite material 1 is within the range of symbol B, it becomes a composite material having mechanical strength equal to or higher than that of the conventional PBT resin composition.

[0033] The composite material 1 may contain an antioxidant, an ultraviolet absorber, a light deterioration inhibitor, a heat stabilizer, a release agent, a dispersant, a colorant, a flame retardant, etc., as long as the effects of the present embodiment are not inhibited.

[0034] The composite material 1 of this embodiment has excellent mechanical properties, thermal properties, and chemical resistance, making it suitable for use as a material for vehicle parts. Examples of such vehicle parts include connectors. However, vehicle parts are not limited to connectors and may include various other electrical or electronic components. For example, vehicle parts may include switches, capacitors, integrated circuits, relays, resistors, light-emitting diodes, coil bobbins, and their peripheral devices.

[0035] Next, the method for manufacturing the composite material 1 of this embodiment will be described. The composite material 1 can be obtained by melt-kneading the raw materials, a matrix resin, glass fibers, and wollastonite, along with additives as needed. Furthermore, known methods can be used for melt-kneading the composite material 1. For example, the composite material 1 can be obtained by pre-blending using a high-speed mixing device such as a Henschel mixer, and then kneading using a known kneader such as a Banbury mixer, kneader, or roll mill.

[0036] Furthermore, composite material 1 can also be obtained by pre-preparing pellets containing only matrix resin, pellets containing matrix resin and glass fibers, and pellets (masterbatch) containing matrix resin and wollastonite, and then melt-mixing them together.

[0037] The vehicle parts of this embodiment can be obtained by injection molding the resulting composite material 1.

[0038] As described above, the composite material 1 of this embodiment comprises a matrix resin 2 and glass fibers 3 and wollastonite 4 dispersed within the matrix resin 2. The matrix resin 2 is polybutylene terephthalate resin, polypropylene resin, or polyamide resin. The composite material 1 contains 1% by weight or more of glass fibers 3 and wollastonite 4, respectively. When the content of glass fibers 3 in the composite material 1 is a% by weight, the content of wollastonite 4 is b% by weight, and the content of matrix resin 2 is 100-a-b% by weight, the following relationships of formulas 1 to 7 are satisfied. Equation 1: a ≥ -0.5000b + 27.5000 (where 1 ≤ b ≤ 10) Equation 2: a ≥ 0.0000b + 22.5000 (where 10 < b ≤ 15) Equation 3: a ≥ -0.3613b + 27.9194 (where 15 < b ≤ 30.5) Equation 4: a ≥ -0.0571b + 18.6429 (where 30.5 < b ≤ 34) Equation 5: a ≥ 0.1429b + 11.8429 (where 34 < b ≤ 37.5) Equation 6: a ≤ -0.7413b + 45.0000 (where 1 ≤ b < 37.5) Equation 7: a > -3.6543b + 30.0000 (where b > 0)

[0039] The composite material 1 of this embodiment is CO ２ Instead of reducing the amount of glass fiber added, which has high CO emissions, ２ The mechanical strength is increased by adding wollastonite, which has a low CO emission rate. ２ It is possible to obtain a composite material that has mechanical strength equivalent to or greater than that of conventional resin compositions with added glass fibers, while reducing emissions.

[0040] In the composite material 1 of this embodiment, the matrix resin may be polybutylene terephthalate resin. By using polybutylene terephthalate resin as the matrix resin, CO ２ It is possible to obtain a composite material that has mechanical strength equivalent to or greater than that of conventional PBT resin compositions with added glass fibers, while reducing emissions.

[0041] The composite material 1 of this embodiment may contain 45.3 to 72% by weight of polybutylene terephthalate resin, 16.7 to 44.3% by weight of glass fiber, and 1 to 37.5% by weight of wollastonite. Such a composite material 1 has mechanical strength equivalent to that of a conventional PBT resin composition, but has a CO2 content higher than that of the PBT resin composition. ２ Emissions can be reduced.

[0042] In the composite material 1 of this embodiment, the wollastonite may be surface-treated with a hydrophobic silane coupling agent containing hydrophobic groups. This improves the adhesion between the matrix resin 2 and the wollastonite 4, and also improves the dispersibility of the wollastonite 4 in the matrix resin 2. As a result, the wollastonite 4's effect as a reinforcing material is enhanced, and the overall strength of the composite material 1 can be increased.

[0043] The vehicle component of this embodiment includes composite material 1. Since composite material 1 has excellent mechanical properties, thermal properties, and chemical resistance, it can be suitably used as a material for vehicle components.

[0044] The embodiment will be described in more detail below with reference to examples, comparative examples, and reference examples, but the embodiment is not limited to these examples.

[0045] First, the following materials were prepared as PBT resin, glass fiber, and wollastonite: • PBT resin: Toray Industries, Inc., PBT resin Trecon (registered trademark) unreinforced grade 1401X06 • Glass fiber: Nitto Boseki Co., Ltd., chopped strand CS3J-941S • Wollastonite: Nippon Talc Co., Ltd., ultrafine fiber WFB5 (average particle size 5-6 μm, average aspect ratio 12:1) • Silane coupling agent: Shin-Etsu Chemical Co., Ltd., KBM-403 (3-glycidoxypropyltrimethoxysilane) or KBM-4803 (glycidoxyoctyltrimethoxysilane)

[0046] Furthermore, the wollastonite was surface-treated using a silane coupling agent as follows: First, wollastonite powder was placed in the chamber of a Henschel mixer and heated to approximately 100°C. Next, the silane coupling agent was sprayed onto the wollastonite in the chamber, and then the mixture was rapidly stirred with the rotating blades inside the chamber. After the wollastonite had been thoroughly stirred, it was removed from the mixer and heated in an oven to approximately 100°C to react the hydroxyl groups on the surface of the wollastonite with the hydroxyl groups of the silane coupling agent. As a result, the surface of the wollastonite was coated with the silane coupling agent, and a hydrophobic wollastonite was obtained.

[0047] Then, using the above materials, pellets 1 containing only PBT resin, pellets 2 consisting of PBT resin and a predetermined amount of glass fiber, and pellets 3 consisting of PBT resin and wollastonite were prepared. In pellets 3 consisting of PBT resin and wollastonite, the wollastonite filling rate was set to 65% by weight.

[0048] Next, Pellets 1 to 3 were weighed out so that the amounts of PBT resin, glass fiber, and wollastonite were as shown in Tables 1 to 5, and then composite materials No. 1 to No. 221 were prepared by melt-kneading.

[0049]

[0050]

[0051]

[0052]

[0053]

[0054] Next, the mechanical properties of the obtained composite materials No. 1 to No. 221 were evaluated. Specifically, the tensile strength, flexural strength, flexural modulus, bending deflection ratio, Izod impact strength, and load deflection temperature of the composite materials No. 1 to No. 221 were measured in accordance with the standards shown in Table 6. The measurement results for each composite material are shown in Tables 1 to 5. In Table 6, the values ​​in the "Specifications" column represent the properties of a conventional PBT resin composition obtained by adding 30% glass fiber to PBT resin.

[0055]

[0056] Furthermore, the CO2 composite material contains 70 wt% PBT resin and 30 wt% glass fiber. ２ CO2 emissions from each composite material when the emission reduction rate is set to 0% ２ The reduction rate of emissions was calculated. Specifically, the GHG emissions from PBT resin were reduced to 4.82E + 00 kg - CO2. ２ Using e as the unit, the GHG emissions from glass fiber are calculated as 2.32E + 00 kg - CO2. ２ Using e / unit, and assuming that the GHG emissions from wollastonite are 1 / 100th of those from glass fiber, the CO2 emissions from each composite material are calculated based on the content of PBT resin, glass fiber, and wollastonite in each composite material. ２ We calculated the CO2 emissions from a composite material containing 70 wt% PBT resin and 30 wt% glass fiber. ２ CO2 emissions from each composite material when the emission reduction rate is set to 0% ２ The reduction rate of emissions was calculated for composite materials No. 1 to No. 221. ２ The reduction rates are shown in Tables 1 through 5.

[0057] The PBT resin, glass fiber, and wollastonite content of the obtained composite materials No. 1 to No. 221 were used as explanatory variables, and each characteristic value (tensile strength, flexural strength, flexural modulus, flexural deflection ratio, Izod impact strength, and load deflection temperature) was used as the objective variable. A CSV file described in a predetermined order was used as training data. These were then input into modeFRONTIOR, a multi-objective optimization tool from ESTECO, and an approximate formula for No. 1 to No. 221 was obtained using a Gaussian process as the algorithm. Using this approximate formula, the range of blending conditions for PBT resin, glass fiber, and wollastonite that satisfy the specified values ​​for tensile strength, flexural strength, flexural modulus, flexural deflection ratio, Izod impact strength, and load deflection temperature shown in Table 6 was determined and plotted on a triangular graph. As a result, the graph for the range indicated by symbol A shown in Figure 2 was obtained.

[0058] Then, by representing the outer perimeter of area A in Figure 2 with an approximate formula where the weight fraction a (wt%) of glass fiber and the weight fraction b (wt%) of wollastonite are variables, we obtained the above formulas 1 to 6. Note that formula 7 is obtained in area A of Figure 2, CO ２ This formula represents the region where emissions are lower than those of a polybutylene terephthalate resin composition containing 30 wt% glass fiber. Figure 3 shows the graph lines and ranges represented by formulas 1 to 7. Therefore, composite materials in range B represented by formulas 1 to 7 have tensile strength, flexural strength, flexural modulus, flexural deflection rate at break, Izod impact strength, and load deflection temperature that are equal to or greater than those of a PBT resin composition containing 30 wt% glass fiber, and CO ２ The amount of emissions will be less than that of the PBT resin composition in question. In Tables 1 to 5, composite materials included in range B represented by formulas 1 to 7 are labeled as examples, and composite materials that do not meet the specifications for each characteristic value in Table 6 (tensile strength, flexural strength, flexural modulus, flexural deflection ratio, Izod impact strength, and load deflection temperature) are labeled as comparative examples. In addition, in Tables 1 to 5, composite materials that meet the specifications for each characteristic value in Table 6 but are not included in range B represented by formulas 1 to 7 are labeled as reference examples.

[0059] The entire contents of Japanese Patent Application No. 2024-200930 (filing date: November 18, 2024) and Japanese Patent Application No. 2025-134060 (filing date: August 12, 2025) are incorporated herein by reference.

[0060] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents.

[0061] 1. Composite material 2. Matrix resin 3. Glass fiber 4. Wollastonite

Claims

1. A composite material comprising a matrix resin and glass fibers and wollastonite dispersed within the matrix resin, wherein the matrix resin is polybutylene terephthalate resin, polypropylene resin, or polyamide resin, the composite material contains 1% by weight or more of the glass fibers and the wollastonite, and when the content of the glass fibers in the composite material is a% by weight, the content of the wollastonite is b% by weight, and the content of the matrix resin is 100-a-b% by weight, the composite material satisfies the following relationships in formulas 1 to 7. Equation 1: a ≥ -0.5000b + 27.5000 (where 1 ≤ b ≤ 10) Equation 2: a ≥ 0.0000b + 22.5000 (where 10 < b ≤ 15) Equation 3: a ≥ -0.3613b + 27.9194 (where 15 < b ≤ 30.5) Equation 4: a ≥ -0.0571b + 18.6429 (where 30.5 < b ≤ 34) Equation 5: a ≥ 0.1429b + 11.8429 (where 34 < b ≤ 37.5) Equation 6: a ≤ -0.7413b + 45.0000 (where 1 ≤ b < 37.5) Equation 7: a > -3.6543b + 30.0000 (where b > 0) 2. The composite material according to claim 1, wherein the matrix resin is a polybutylene terephthalate resin.

3. The composite material according to claim 2, comprising 45.3 to 72% by weight of the polybutylene terephthalate resin, 16.7 to 44.3% by weight of the glass fiber, and 1 to 37.5% by weight of the wollastonite.

4. The composite material according to any one of claims 1 to 3, wherein the wollastonite is surface-treated with a hydrophobic silane coupling agent containing hydrophobic groups.

5. A vehicle component comprising the composite material according to any one of claims 1 to 4.

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