Fiber Reinforced Resin Material, Molded Article, and Method for Producing Fiber Reinforced Resin Material

Abstract

To provide a fiber-reinforced resin material which prevents breakage of long fibers of a thermoplastic resin when impregnating to the long fibers and can be efficiently manufactured, a molding using the fiber-reinforced resin material, and a method for manufacturing a fiber-reinforced resin material.SOLUTION: A fiber-reinforced resin material contains 65-170 pts.mass of inorganic fibers having a number average fiber length of 3 mm or more with respect to 100 pts.mass of a thermoplastic resin component, and contains 0.05-0.50 pt.mass of at least one of a metal acetate in 100 pts.mass of the thermoplastic resin component.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a fiber-reinforced resin material, a molded article, and a method for producing a fiber-reinforced resin material.

Background Art

[0002] Conventionally, in order to improve the mechanical strength of a molded article formed from a thermoplastic resin, a fiber-reinforced resin material in which reinforcing fibers are blended with the thermoplastic resin has been studied. In particular, in order to increase the mechanical strength of a molded article, a fiber-reinforced resin material using long fibers has been studied (Patent Document 1, Patent Document 2). Further, in Patent Document 2, when producing such a fiber-reinforced resin material, glass fiber roving is introduced into the crosshead of an impregnation die filled with a molten polyamide resin composition to obtain a resin-impregnated glass fiber roving bundle. Further, the obtained resin-impregnated glass fiber roving bundle is continuously drawn out from a spinneret to obtain one strand. Further, this strand is cooled and solidified in a water-cooled bath, and the strand is made into pellets by a pelletizer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, as described above, when impregnating a thermoplastic resin into long fibers such as glass fiber roving, the thermoplastic resin may thicken and break the long fibers. The present invention aims to solve such problems, and provides a fiber-reinforced resin material in which long fibers are less likely to break during impregnation of a thermoplastic resin into the long fibers and can be efficiently manufactured, a molded article using the fiber-reinforced resin material, and a method for manufacturing the fiber-reinforced resin material.

Means for Solving the Problems

[0005] As a result of investigations by the present inventors under the above problems, it has been found that the above problems can be solved by blending a predetermined amount of a metal acetate salt into a thermoplastic resin component. Specifically, the above problems have been solved by the following means. <1>A fiber-reinforced resin material containing 65 to 170 parts by mass of inorganic fibers having a number average fiber length of 3 mm or more with respect to 100 parts by mass of a thermoplastic resin component, and containing 0.05 to 0.50 parts by mass of at least one kind of metal acetate salt in 100 parts by mass of the thermoplastic resin component. <2>The fiber-reinforced resin material according to <1>, wherein the metal acetate salt contains at least one kind selected from sodium acetate, calcium acetate, and magnesium acetate. <3>The fiber-reinforced resin material according to <1> or <2>, wherein the inorganic fibers contain glass fibers and / or carbon fibers. <4>The fiber-reinforced resin material according to <1> or <2>, wherein the inorganic fibers contain glass fibers. <5>The fiber-reinforced resin material according to any one of <1> to <4>, wherein the thermoplastic resin component contains a polyamide resin. <6>The fiber-reinforced resin material according to <5>, wherein the polyamide resin contains a structural unit derived from a diamine and a structural unit derived from a dicarboxylic acid, 70 mol% or more of the structural unit derived from the diamine is derived from xylylenediamine, and 70 mol% or more of the structural unit derived from the dicarboxylic acid is derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. <7>The fiber-reinforced resin material according to any one of <1> to <6>, wherein the number average fiber length of the inorganic fibers is 10 mm or less. <8>The fiber-reinforced resin material according to any one of <1> to <6>, wherein the number average fiber length of the inorganic fiber is 2 cm or more. <9>The fiber-reinforced resin material according to any one of <1> to <7>, wherein the fiber-reinforced resin material is a pellet. <10>The fiber-reinforced resin material according to any one of <1> to <6> and <8>, wherein the fiber-reinforced resin material is a UD tape (unidirectional tape). <11>A molded article formed from the fiber-reinforced resin material according to any one of <1> to <10>. <12>A method for producing a fiber-reinforced resin material, comprising impregnating 100 parts by mass of a thermoplastic resin component containing 0.05 to 0.50 parts by mass of at least one metal acetate in 100 parts by mass of a thermoplastic resin component with 65 to 170 parts by mass of an inorganic fiber having a number average fiber length of 2 cm or more. <13>The method for producing a fiber-reinforced resin material according to <12>, comprising masterbatch-forming the metal acetate with a thermoplastic resin and then blending it with other components to obtain the thermoplastic resin component. <14>The method for producing a fiber-reinforced resin material according to <13>, wherein the blending is a dry blend. <15>The method for producing a fiber-reinforced resin material according to any one of <12> to <14>, wherein the fiber-reinforced resin material is the fiber-reinforced resin material according to any one of <1> to <10>.

Advantages of the Invention

[0006] According to the present invention, it is possible to provide a fiber-reinforced resin material in which long fibers are less likely to break during impregnation of a thermoplastic resin with long fibers and which can be efficiently produced, a molded article using the fiber-reinforced resin material, and a method for producing the fiber-reinforced resin material.

Modes for Carrying Out the Invention

[0007] Hereinafter, modes for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. The following present embodiment is an exemplification for explaining the present invention, and the present invention is not limited to only the present embodiment. In addition, in this specification, "~" is used to mean including the numerical values described before and after it as the lower limit value and the upper limit value. In this specification, various physical property values and characteristic values shall be those at 23°C unless otherwise specified. When the standards shown in this specification vary depending on the year and the measurement methods, etc., they shall be based on the standards as of January 1, 2021 unless otherwise specified.

[0008] The fiber-reinforced resin material of this embodiment contains 65 to 170 parts by mass of inorganic fibers having a number average fiber length of 3 mm or more with respect to 100 parts by mass of the thermoplastic resin component, and contains 0.05 to 0.50 parts by mass of at least one metal acetate in 100 parts by mass of the thermoplastic resin component. By adopting such a configuration, in the manufacturing process of the fiber-reinforced material, breakage of long fibers can be effectively suppressed, and a fiber-reinforced resin material can be efficiently obtained. That is, by blending a metal acetate into the thermoplastic resin component, an increase in the viscosity of the resin in the impregnation die can be suppressed, and by suppressing breakage of long fibers (for example, glass fiber rovings), productivity can be significantly improved. The reason is presumed to be as follows. First, the polymerization of the thermoplastic resin tends to proceed under acidic conditions. In this embodiment, it is presumed that by blending a metal acetate to create basic conditions, an increase in molecular weight could be suppressed. On the other hand, if the blending amount of the metal acetate is too large, the impregnation proceeds efficiently, but due to an extreme decrease in viscosity, the ash content decreases, and it is presumed that the mechanical strength of the molded product formed from the obtained fiber-reinforced resin material tends to be inferior. In this embodiment, it is presumed that the above problems could be solved by adjusting the blending amount of the metal acetate.

[0009] The fiber-reinforced resin material of this embodiment contains a thermoplastic resin component. The thermoplastic resin component contains a metal acetate in addition to the thermoplastic resin. Further, it may contain other resin additives.

[0010] The thermoplastic resin contained in the thermoplastic resin component is not particularly defined, and examples thereof preferably include polyester resins such as polyethylene terephthalate resin, polytrimethylene terephthalate resin, and polybutylene terephthalate resin; polyamide resins; polycarbonate resins; styrene resins; polyolefin resins such as polyethylene resin, polypropylene resin, and cyclic olefin resin; polyacetal resins; polyimide resins; polyetherimide resins; polyurethane resins; polyphenylene ether resins; polyphenylene sulfide resins; polysulfone resins; polymethacrylate resins; etc. It is preferable to contain at least one of polybutylene terephthalate resin, polyamide resin, polycarbonate resin, and polyacetal resin, and it is more preferable to contain a polyamide resin.

[0011] The thermoplastic resin in this embodiment is particularly suitable for thermoplastic resins obtained by polycondensation reaction. This is presumably because the polymerization reaction can be suppressed under basic conditions. The thermoplastic resin in this embodiment is also preferably a crystalline thermoplastic resin. In the crystalline thermoplastic resin, the effect of manufacturing stabilization is more effectively exerted. A crystalline thermoplastic resin refers to one that exhibits a distinct exothermic peak when measured according to a differential scanning calorimeter. In this embodiment, in particular, a polyamide resin is preferred. The impregnation of the polyamide resin into the long fibers is carried out at a severe heating temperature. At this time, the polyamide resin begins to decompose, the end group concentration increases, reacts with the surface treatment agent of the long fibers, etc., and tends to have a higher viscosity.

[0012] The type of the polyamide resin used in this embodiment is not particularly defined, and it may be an aliphatic polyamide resin or a semi-aromatic polyamide resin. Examples of the aliphatic polyamide resin include polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 66, polyamide 610, polyamide 612, and polyamide 6 / 66, and polyamide 66 is preferred. The polyamide resin used in this embodiment preferably contains a semi-aromatic polyamide resin. For example, it is more preferable that 90% by mass or more of the polyamide resin contained in the thermoplastic resin component in this embodiment is a semi-aromatic polyamide resin. Here, the semi-aromatic polyamide resin is composed of a structural unit derived from diamine and a structural unit derived from dicarboxylic acid, and 20 to 80 mol% of the total structural units of the structural unit derived from diamine and the structural unit derived from dicarboxylic acid are structural units containing an aromatic ring. By using such a semi-aromatic polyamide resin, the mechanical strength of the obtained molded product can be increased. Examples of the semi-aromatic polyamide resin include terephthalic acid-based polyamide resins (polyamide 6T, polyamide 9T, polyamide 10T), xylylenediamine-based polyamide resins described later, and the like.

[0013] At least one of the polyamide resins used in this embodiment contains a structural unit derived from diamine and a structural unit derived from dicarboxylic acid, and preferably 70 mol% or more of the structural unit derived from diamine is derived from xylylenediamine, and 70 mol% or more of the structural unit derived from dicarboxylic acid is derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. Hereinafter, such a polyamide resin may be referred to as a xylylenediamine-based polyamide resin. For the structural unit derived from diamine of the xylylenediamine-based polyamide resin, more preferably 75 mol% or more, still more preferably 80 mol% or more, even more preferably 85 mol% or more, even more preferably 90 mol% or more, and still more preferably 95 mol% or more is derived from xylylenediamine. For the structural unit derived from dicarboxylic acid of the xylylenediamine-based polyamide resin, more preferably 75 mol% or more, still more preferably 80 mol% or more, even more preferably 90 mol% or more, and even more preferably 95 mol% or more is derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms.

[0014] Examples of diamines other than metaxylylenediamine and paraxylylenediamine that can be used as the diamine component of the raw material for xylylenediamine-based polyamide resins include aliphatic diamines such as tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, etc., alicyclic diamines such as 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis(4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminomethyl)decalin, bis(aminomethyl)tricyclodecane, etc., and diamines having an aromatic ring such as bis(4-aminophenyl)ether, paraphenylenediamine, bis(aminomethyl)naphthalene, etc. One or more of these can be mixed and used.

[0015] Examples of α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms, which are preferable for use as the dicarboxylic acid component of the raw material for xylylenediamine-based polyamide resins, include aliphatic dicarboxylic acids such as succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, adipic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, etc. One or more of these can be mixed and used. Among these, adipic acid or sebacic acid is more preferable, and adipic acid is even more preferable because the melting point of the polyamide resin falls within an appropriate range for molding processing.

[0016] Examples of dicarboxylic acid components other than the α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms include phthalic acid compounds such as isophthalic acid, terephthalic acid, and orthophthalic acid, and isomers of naphthalenedicarboxylic acid such as 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid. One or more of them can be mixed and used.

[0017] In the xylylenediamine-based polyamide resin of this embodiment, it is preferable that 0 to 100 mol% of the structural units derived from diamine are derived from p-xylylenediamine and 100 to 0 mol% are derived from m-xylylenediamine. More preferably, 0 to 70 mol% are derived from p-xylylenediamine and 100 to 30 mol% are derived from m-xylylenediamine. Even more preferably, 0 to 50 mol% are derived from p-xylylenediamine and 100 to 50 mol% are derived from m-xylylenediamine. Still more preferably, 0 to 20 mol% are derived from p-xylylenediamine and 100 to 80 mol% are derived from m-xylylenediamine. Also, in the xylylenediamine-based polyamide resin of this embodiment, it is preferable that 70 mol% or more (preferably 80 mol% or more, more preferably 90 mol% or more) of the structural units derived from dicarboxylic acid are derived from sebacic acid and / or adipic acid (preferably adipic acid). In any of the above embodiments, the total of the structural units derived from diamine does not exceed 100 mol%, and the total of the structural units derived from dicarboxylic acid also does not exceed 100 mol%.

[0018] Incidentally, the xylylenediamine-based polyamide resin is mainly composed of structural units derived from diamine and structural units derived from dicarboxylic acid, but it does not completely exclude structural units other than these. Needless to say, it may contain structural units derived from lactams such as ε-caprolactam and laurolactam, and aliphatic aminocarboxylic acids such as aminocaproic acid and aminoundecanoic acid. Here, the main component means that among the structural units constituting the xylylenediamine-based polyamide resin, the total number of structural units derived from diamine and structural units derived from dicarboxylic acid is the largest among all structural units. In the present embodiment, in the xylylenediamine-based polyamide resin, the total of the structural units derived from diamine and the structural units derived from dicarboxylic acid preferably accounts for 90% by mass or more, more preferably 95% by mass or more, and even more preferably 98% by mass or more of all structural units.

[0019] An example of the blend form of the thermoplastic resin in the thermoplastic resin component is a blend of 80 to 100 parts by mass of a xylylenediamine-based polyamide resin and 20 to 0 parts by mass of an aliphatic polyamide resin (preferably polyamide 66), and preferably a blend of 85 to 99 parts by mass of a xylylenediamine-based polyamide resin and 15 to 1 part by mass of an aliphatic polyamide resin.

[0020] The content of the thermoplastic resin (preferably a polyamide resin) in the thermoplastic resin component is preferably 80% by mass or more, more preferably 85% by mass or more, further preferably 90% by mass or more, and even more preferably 95% by mass or more. By setting the content to be not less than the lower limit value, the mechanical strength of the molded product tends to improve. The upper limit value of the content of the thermoplastic resin in the thermoplastic resin component is a value at which the total of the thermoplastic resin and the metal acetate is 100% by mass. Incidentally, as will be described later, when some components contained in the thermoplastic resin component are made into a masterbatch, the amount including the thermoplastic resin for making such a masterbatch is taken as the content of the thermoplastic resin. The thermoplastic resin component in this embodiment may contain only one type of each thermoplastic resin, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

[0021] On the other hand, in this embodiment, in 100 parts by mass of the thermoplastic resin component, at least one kind of metal acetate is contained in an amount of 0.05 to 0.50 parts by mass. By containing the metal acetate in a proportion of 0.05 parts by mass or more, thickening of the thermoplastic resin component can be suppressed, and impregnation of the thermoplastic resin component into the long fibers can be effectively promoted. As a result, the long fibers are less likely to break, and the productivity of the fiber-reinforced resin material is improved. On the other hand, by setting the content of the metal acetate to 0.50 parts by mass or less in 100 parts by mass of the thermoplastic resin component, the mechanical strength of the obtained fiber-reinforced resin material and further the molded product obtained from the fiber-reinforced resin material can be increased. The fiber-reinforced resin material of this embodiment may contain only one kind of metal acetate, or may contain two or more kinds. When two or more kinds are contained, the total amount is within the above range.

[0022] The metal acetate is preferably an alkali metal salt of acetic acid and an alkaline earth metal salt of acetic acid, and an alkali metal salt of acetic acid is preferred. In this specification, the alkali metal means lithium, sodium, potassium, rubidium, cesium, francium, sodium and potassium are preferred, and sodium is more preferred. In this specification, the alkaline earth metal means beryllium, magnesium, calcium, strontium, barium, radium, and magnesium and calcium are preferred. In this embodiment, the metal acetate preferably contains at least one selected from sodium acetate, calcium acetate, and magnesium acetate, and more preferably contains sodium acetate.

[0023] The thermoplastic resin component in this embodiment may contain other components in addition to the thermoplastic resin and the metal acetate. Other components include nucleating agents, mold release agents, antioxidants, hydrolysis inhibitors, flame retardants, flame retardant aids, reinforcing fillers, pigments, ultraviolet absorbers, antistatic agents, antifogging agents, plasticizers, dispersants, antibacterial agents, and the like.

[0024] As the nucleating agent, talc and calcium carbonate are preferred, and talc is more preferred. The average particle size of the nucleating agent preferably has a lower limit of 0.1 μm or more, more preferably 1 μm or more, and even more preferably 3 μm or more. The average particle size of the nucleating agent preferably has an upper limit of 40 μm or less, more preferably 30 μm or less, even more preferably 28 μm or less, still more preferably 15 μm or less, and yet more preferably 10 μm or less. The content of the nucleating agent is preferably 0.1 to 2.0 parts by mass per 100 parts by mass of the thermoplastic resin component. The thermoplastic resin component may contain only one kind of nucleating agent or may contain two or more kinds. When two or more kinds are contained, the total amount preferably falls within the above range.

[0025] In order to improve the mold release property during molding, it is preferable to blend a mold release agent with the thermoplastic resin component. Examples of the mold release agent include carboxylic acid amide waxes, bisamide waxes, long-chain fatty acid metal salts, etc., and long-chain fatty acid metal salts are preferred.

[0026] The long-chain fatty acid metal salt is a metal salt of a long-chain fatty acid having 16 to 36 carbon atoms, and examples thereof include calcium stearate, calcium montanate, sodium montanate, zinc stearate, aluminum stearate, sodium stearate, lithium stearate, etc. In addition, as the mold release agent, the descriptions in paragraphs 0060 to 0063 of JP-A No. 2012-132027 can be referred to, and this content is incorporated herein.

[0027] The content of the release agent is preferably 0.001 to 1.0 part by mass, more preferably 0.005 to 0.7 part by mass, per 100 parts by mass of the thermoplastic resin component. By setting the content to be equal to or higher than the lower limit value, a sufficient release effect can be exhibited and the moldability can be improved. By setting it to be equal to or lower than the upper limit value, it becomes possible to maintain high the mechanical strength of the obtained fiber-reinforced resin material and further the molded product formed from the fiber-reinforced resin material.

[0028] Also, the thermoplastic resin component in the present embodiment preferably does not substantially contain a reinforcing material. By the thermoplastic resin component not substantially containing a reinforcing material, the fluidity of the thermoplastic resin component can be further improved. Here, not substantially containing means that the content of the reinforcing material is 5% by mass or less of the thermoplastic resin component, more preferably 3% by mass or less, and even more preferably 1% by mass or less.

[0029] Next, the inorganic fibers impregnated with the thermoplastic resin component will be described. The inorganic fibers used in the present embodiment are so-called long fibers having a number average fiber length of 3 mm or more. When using long fibers, a decrease in productivity is likely to occur, but in the present embodiment, this point is effectively avoided by using a metal acetate salt. Examples of the inorganic fibers contained in the fiber-reinforced resin material of the present embodiment are carbon fibers and / or glass fibers, and glass fibers are preferred.

[0030] The inorganic fibers in the present embodiment mean fibrous inorganic materials. More specifically, a chopped shape in which 1,000 to 10,000 inorganic fibers are bundled and cut to a predetermined length is preferred. The inorganic fibers in the present embodiment are so-called long fibers having a number average fiber length of 3 mm or more, but the length thereof can be appropriately determined according to the use and the like. In this embodiment, the inorganic fiber preferably has a number average fiber length of 5 mm or more, more preferably 2 cm or more, still more preferably 10 cm or more, and even more preferably 1 m or more, depending on the application. By setting the lower limit value or more, the mechanical strength of the obtained molded product can be further improved. In addition, the number average fiber length of the inorganic fiber is usually 10,000 m or less, but more preferably 10 mm or less, depending on the application. In particular, when the number average fiber length of the inorganic fiber is 10 mm or less (preferably 4 to 10 mm, more preferably 5 to 10 mm), the fiber reinforced resin material is preferably a pellet. In addition, when the number average fiber length of the inorganic fiber is 2 cm or more (preferably 10 cm or more, and preferably 10,000 m or less), the fiber reinforced resin material is preferably a UD tape (unidirectional tape) or a cross material (fabric), and preferably a UD tape (unidirectional tape). The number average fiber length is obtained by randomly extracting the inorganic fibers to be measured for the fiber length from the image obtained by observation with an optical microscope, measuring the long side thereof, and calculating the number average fiber length from the obtained measurement values. The magnification of the observation is set to 20 times, and the number of measurements is 1,000 or more. Generally, it corresponds to the cut length. In addition, the cross section of the inorganic fiber may be any shape such as circular, elliptical, oblong, rectangular, a shape with semi - circles combined on both short sides of a rectangle, or a mayfly shape, etc., but a circular shape is preferred. The circular shape here includes, in addition to the circular shape in the mathematical sense, those generally referred to as circular in the technical field of the present invention. The number average fiber diameter of the inorganic fiber preferably has a lower limit of 4.0 μm or more, more preferably 4.5 μm or more, and even more preferably 5.0 μm or more. The upper limit of the number average fiber diameter of the inorganic fiber is preferably 30.0 μm or less, more preferably 25.0 μm or less, and even more preferably 20.0 μm or less. The number average fiber diameter of the inorganic fiber is calculated from the obtained measurement values by randomly extracting the glass fibers to be measured for the fiber diameter from the image obtained by observation with an electron microscope, measuring the fiber diameter near the central part, and observing at a magnification of 1,000 times and a measurement number of 1,000 or more. The number average fiber diameter of the glass fiber having a cross section other than circular is the number average fiber diameter when converted into a circle having the same area as the cross-sectional area.

[0031] Next, the glass fiber preferably used in the present embodiment will be described. As the glass fiber, fibers obtained by melt spinning generally supplied E glass, C glass, A glass, S glass (D glass, M glass, alkali-resistant glass, etc.) can be used, and any glass fiber can be used as long as it can be formed, and it is not particularly limited. In the present invention, it is preferable to contain E glass. The glass fiber may be treated with a surface treatment agent.

[0032] The glass fiber is available as a commercial product. Examples of commercial products include ER2400T-423N manufactured by Nippon Electric Glass Co., Ltd., RS2400QR-843 manufactured by Nitto Boseki Co., Ltd., ER4301H-2400 manufactured by Chongqing International Composite Materials Co., Ltd. (CPIC), etc.

[0033] In the fiber-reinforced resin material of this embodiment, the content of the inorganic fiber is 65 parts by mass or more, preferably 70 parts by mass or more, more preferably 80 parts by mass or more, further preferably 90 parts by mass or more, still more preferably 110 parts by mass or more, and even more preferably 115 parts by mass or more with respect to 100 parts by mass of the thermoplastic resin. By setting it to be not less than the lower limit value, the mechanical strength of the obtained fiber-reinforced resin material, and further the molded product obtained from the fiber-reinforced resin material tends to be further improved. Also, in the fiber-reinforced resin material of this embodiment, the content of the inorganic fiber is 170 parts by mass or less, preferably 165 parts by mass or less, more preferably 160 parts by mass or less, further preferably 150 parts by mass or less, still more preferably 140 parts by mass or less, and even more preferably 130 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin. By setting it to be not more than the upper limit value, the production of the fiber-reinforced resin material tends to be more stable. The fiber-reinforced resin material of this embodiment may contain only one kind of inorganic fiber, or may contain two or more kinds. When two or more kinds are contained, it is preferable that the total amount is within the above range.

[0034] In the fiber-reinforced resin material of this embodiment, it is preferable that the total amount of the thermoplastic resin and the inorganic fiber occupies 90% by mass or more, and more preferably 95% by mass or more of the fiber-reinforced resin material.

[0035] Next, the manufacturing method of the fiber-reinforced resin material of this embodiment will be described. The manufacturing method of the fiber-reinforced resin material of this embodiment includes impregnating 100 parts by mass of a thermoplastic resin component containing at least one metal acetate salt in an amount of 0.05 to 0.50 parts by mass in 100 parts by mass of the thermoplastic resin component with 65 to 170 parts by mass of inorganic fibers having a number average fiber length of 2 cm or more. By adopting such a method, the inorganic fibers are not broken during the manufacturing process, and the fiber-reinforced resin material can be efficiently manufactured. In the method for manufacturing the fiber-reinforced resin material of the present embodiment, it is preferable to masterbatch the metal acetate salt with a thermoplastic resin and then blend it with other components to obtain the thermoplastic resin component. By masterbatch the metal acetate salt, the basicity due to the volatilization of acetic acid in the masterbatch process is promoted, and the breakage of inorganic fibers and acetic acid odor during the production of the fiber-reinforced resin material can be more effectively suppressed. Here, the other components are other components that may be blended with the thermoplastic resin or the fiber-reinforced resin material, and are synonymous with the thermoplastic resin and other components described in the above-mentioned fiber-reinforced resin material, and the preferable ranges and their blending ratios are also the same. The resin for masterbatch is the thermoplastic resin constituting the fiber-reinforced resin material. For example, when the thermoplastic resin contained in the fiber-reinforced resin material is a polyamide resin, it is preferable that the thermoplastic resin for masterbatch is also a polyamide resin. Unless otherwise specified, the thermoplastic resin contained in the thermoplastic resin component in the present embodiment means the one including the thermoplastic resin used for masterbatch. The concentration of the metal acetate salt in the masterbatch is preferably 0.50% by mass or more, more preferably 1.00% by mass or more, still more preferably 1.50% by mass or more, and may be 2.00% by mass or more. Also, the concentration of the metal acetate salt in the masterbatch is preferably 4.50% by mass or less, more preferably 4.00% by mass or less, still more preferably 3.50% by mass or less, and may be 3.00% by mass or less. The masterbatch may contain only one kind of metal acetate salt or two or more kinds. When two or more kinds are contained, it is preferable that the total amount is within the above range.

[0036] When the metal acetate salt is masterbatched, it is preferably blended with a thermoplastic resin and other components blended as required. The blending may be dry blending or melt blending, but dry blending is preferable. By performing dry blending, the decomposition of the thermoplastic resin can be effectively suppressed without giving an unnecessary heat history.

[0037] The fiber-reinforced resin material of this embodiment is usually manufactured by impregnating inorganic fibers with a molten thermoplastic resin component. For example, when the fiber-reinforced resin material is pellets, rovings are used as the inorganic fibers. While opening the inorganic fibers, the inorganic fibers are impregnated with a melt of the thermoplastic resin component, then taken up as strands, and cut to a desired pellet length. The cut length at this time becomes the number-average fiber length of the inorganic fibers. Therefore, the preferable range of the cut length is the same as the number-average fiber length of the above-mentioned inorganic fibers.

[0038] Also, when the fiber-reinforced resin material is a UD tape (unidirectional tape), rovings are used as the inorganic fibers. The rovings are arranged at equal intervals, spread out, and then passed through an impregnation die. At this time, a melt of the thermoplastic resin component is supplied, and the inorganic fibers are impregnated with the thermoplastic resin component in the impregnation die. By such a process, a UD tape can be obtained. The impregnation die preferably includes an impregnation roll. The impregnation roll can efficiently impregnate the inorganic fibers with the thermoplastic resin component. Also, as another manufacturing example when the fiber-reinforced resin material is a UD tape (unidirectional tape), inorganic fibers arranged in parallel in one direction or two or more directions are used as the inorganic fibers, and methods such as extruding into a film shape with an extruder and passing between a pair of impregnation rolls, or thermally pressing by overlapping with a film composed of a thermoplastic resin component are also exemplified. At this time, an example of the inorganic fibers arranged in parallel in one direction or two or more directions is a woven fabric of inorganic fibers. Also, it is preferable to perform thermal pressing with two films composed of a thermoplastic resin component sandwiching the woven fabric of inorganic fibers.

[0039] Also, a fiber-reinforced resin material obtained by thermally pressing with a non-woven fabric of inorganic fibers and a film composed of a thermoplastic resin component is also exemplified as the inorganic fibers.

[0040] Next, the molded article formed from the fiber-reinforced resin material of this embodiment will be described. The type of the molded product formed from the fiber-reinforced resin material of the present embodiment is not particularly limited. Further, the molded product is not limited to the final product, but also includes various parts. The molded product in the present embodiment is preferably a part of a structural member, a part of a portable electronic device, a part of a vehicle and a medical device, an electronic part including other electric circuits, a container for food and medicine, and a composite material for forming these.

Example

[0041] The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, treatment details, treatment procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. When it is difficult to obtain the measuring instruments etc. used in the examples due to their obsolescence etc., measurement can be performed using other instruments having equivalent performance.

[0042] 1. Raw materials MXD6: Polyamide resin synthesized from metaxylylenediamine and adipic acid, manufactured by Mitsubishi Gas Chemical Company, #6000 PA66: Polyamide 66, manufactured by DuPont, Zytel 101NC-10 Talc: MS Talc, manufactured by Nippon Talc Co., Ltd. StCa: Calcium stearate, manufactured by Nitto Kasei Kogyo Co., Ltd. AcNa: Sodium acetate (anhydrous), manufactured by Daito Chemical Co., Ltd. Glass fiber: Glass fiber roving, manufactured by Chongqing International Composite Materials Co., Ltd. (CPIC), ER4301H-2400 (number average fiber diameter of monofilament: 17 μm, TEX number: 2400 TEX)

[0043] <Manufacture of masterbatch> A masterbatch of sodium acetate (masterbatch concentration 2.60% by mass) was manufactured as follows. 5000 g of polyamide MXD6 #6000 and 135 g of sodium acetate were dry-blended, and then supplied from the top feed port of a twin-screw extruder (trade name: TEM26SS, manufactured by Shibaura Machine Co., Ltd.), and melt-kneaded at a cylinder set temperature of 260 °C and a screw rotation speed of 200 rpm to obtain a masterbatch of sodium acetate.

[0044] 2. Examples 1 to 4, Comparative Examples 1 to 3 <Method for manufacturing resin pellets> Among the components listed in Table 1, the components excluding glass fiber were dry-blended, and then supplied from the top feed port of a twin-screw extruder (trade name: TEM26SS, manufactured by Shibaura Machine Co., Ltd.) at the ratios (unit: parts by mass) shown in Table 1 below. The cylinder set temperature was set at the melting point of the polyamide resin + 40 °C, and the screw rotation speed was 200 rpm for melt-kneading, and the melt of the resin component was introduced into the impregnation tank. The temperature in the impregnation tank was set at the melting point of the polyamide resin + 80 °C. Four glass fiber rovings were heated to a preheater temperature of 200 °C and then introduced into an impregnation tank equipped with a resin impregnation roll through a crosshead. While opening and pulling the glass fiber rovings, they were impregnated with the melt of the resin component obtained above, and then taken out as strands from a nozzle with an inner diameter of 1.9 mm at a take-up speed of 10 m / min and cut into lengths of 6 mm to obtain pellets. The cut length and the fiber length of the glass fiber in the pellets were the same length.

[0045] <Long fiber productivity> Production was carried out for 10 hours, and the time from the start of production to the breakage of the roving was observed. If breakage occurred in even one of the four, it was judged as breakage.

[0046] <Ash content (pellets)> The pellets obtained by the above manufacturing method were dried at 120 °C for 4 hours, then weighed in a magnetic crucible, and subjected to ashing treatment in an electric furnace maintained at 650 °C for 2 hours. The ash content (unit: mass%) was calculated from the mass before and after the ashing treatment.

[0047] <Specific gravity> After drying the pellets obtained by the above manufacturing method at 120 °C for 4 hours, an ISO tensile test piece (4 mm thick) was injection molded using an injection molding machine (manufactured by Shibaura Machine Co., Ltd., "EC75SX") under the conditions of a cylinder temperature of 280 °C, a mold temperature of 130 °C, and a molding cycle of 50 seconds. The specific gravity of the obtained molded body was measured by the Archimedes method in accordance with ISO 1183.

[0048] <Method for Measuring Crystallization Temperature (Tcc)> The measurement of the crystallization temperature was carried out in accordance with JIS K7121 and K7122. Specifically, using a differential scanning calorimeter, the polyamide resin was charged into the measurement pan of the differential scanning calorimeter, heated from 30 to 300 °C at a heating rate of 20 °C / min under a nitrogen atmosphere, held at 300 °C for 3 minutes, and then cooled at a cooling rate of 10 °C / min. The peak temperature of the exothermic peak observed during cooling was measured to determine the crystallization temperature during cooling (Tcc, unit: °C). As the differential scanning calorimeter, "DSC7020 AUTO" manufactured by SII NanoTechnology Inc. was used.

[0049] <Flexural Strength and Flexural Modulus> After drying the pellets obtained by the above manufacturing method at 120 °C for 4 hours, an ISO tensile test piece (4 mm thick) was injection molded using an injection molding machine (manufactured by Shibaura Machine Co., Ltd., "EC75SX") under the conditions of a cylinder temperature of 280 °C, a mold temperature of 130 °C, and a molding cycle of 50 seconds. In accordance with ISO 178, the flexural strength (unit: MPa) and flexural modulus (unit: GPa) were measured at a temperature of 23 °C using the above ISO tensile test piece (4 mm thick).

[0050] <Charpy Impact Strength> After drying the pellets obtained by the above manufacturing method at 120 °C for 4 hours, an ISO tensile test piece (4 mm thick) was injection molded using an injection molding machine (manufactured by Shibaura Machine Co., Ltd., "EC75SX") under the conditions of a cylinder temperature of 280 °C, a mold temperature of 130, and a molding cycle of 50 seconds. The measurement of the Charpy impact strength with a notch was carried out in accordance with the ISO 179 standard.

[0051]

Table 1

[0052]

Table 2

[0053] As is clear from the above results, in the present invention (Examples 1 to 4), breakage of the long fibers could be effectively suppressed, and the fiber-reinforced resin material (resin pellets) could be efficiently produced. Further, the molded article obtained from the fiber-reinforced resin material also had high mechanical strength. When the metal acetate salt was not contained (Comparative Examples 1 and 2), the roving fibers were cut during the production, resulting in low productivity. On the other hand, when the metal acetate salt was blended at a ratio exceeding 0.50 parts by mass with respect to 100 parts by mass of the thermoplastic resin component (Comparative Example 3), the fiber-reinforced resin material (resin pellets) could be efficiently produced, but the mechanical strength of the molded article obtained from the fiber-reinforced resin material was inferior.

Claims

1. Containing 65 to 170 parts by mass of inorganic fibers having a number average fiber length of 3 mm or more with respect to 100 parts by mass of the thermoplastic resin component, A fiber-reinforced resin material containing 0.05 to 0.50 parts by mass of at least one metal acetate in 100 parts by mass of the thermoplastic resin component.

2. The fiber-reinforced resin material according to claim 1, wherein the metal acetate contains at least one selected from sodium acetate, calcium acetate, and magnesium acetate.

3. The fiber-reinforced resin material according to claim 1 or 2, wherein the inorganic fibers contain glass fibers and / or carbon fibers.

4. The fiber-reinforced resin material according to claim 1 or 2, wherein the inorganic fibers contain glass fibers.

5. The fiber-reinforced resin material according to any one of claims 1 to 4, wherein the thermoplastic resin component contains a polyamide resin.

6. The polyamide resin contains a structural unit derived from diamine and a structural unit derived from dicarboxylic acid, 70 mol% or more of the structural unit derived from diamine is derived from xylylenediamine, and 70 mol% or more of the structural unit derived from dicarboxylic acid is derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. The fiber-reinforced resin material according to claim 5.

7. The fiber-reinforced resin material according to any one of claims 1 to 6, wherein the number average fiber length of the inorganic fibers is 10 mm or less.

8. The fiber-reinforced resin material according to any one of claims 1 to 6, wherein the number average fiber length of the inorganic fibers is 2 cm or more.

9. The fiber-reinforced resin material according to any one of claims 1 to 7, wherein the fiber-reinforced resin material is a pellet.

10. The fiber-reinforced resin material according to any one of claims 1 to 6 and 8, wherein the fiber-reinforced resin material is a UD tape (unidirectional tape).

11. A molded article formed from the fiber-reinforced resin material according to any one of claims 1 to 10.

12. A method for producing a fiber-reinforced resin material, comprising impregnating 100 parts by mass of a thermoplastic resin component containing 0.05 to 0.50 parts by mass of at least one metal acetate in 100 parts by mass of the thermoplastic resin component with 65 to 170 parts by mass of inorganic fibers having a number average fiber length of 2 cm or more.

13. The method for producing a fiber-reinforced resin material according to claim 12, comprising masterbatchizing the metal acetate with a thermoplastic resin and then blending it with other components to obtain the thermoplastic resin component.

14. The manufacturing method of the fiber-reinforced resin material according to claim 13, wherein the blend is a dry blend.

15. The manufacturing method of the fiber-reinforced resin material according to any one of claims 12 to 14, wherein the fiber-reinforced resin material is the fiber-reinforced resin material according to any one of claims 1 to 10.

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