Composite material component, composite material, mobile body, method for manufacturing composite material, and method for manufacturing film.

Abstract

To provide a member for composite materials that resists breaking and has excellent handleability; during the molding of the composite material, exhibits excellent impregnation and thermal fusion with carbon fiber; and after its molding, provides a composite material having excellent flame retardancy and water absorption resistance as well as an excellent balance between strength and impact resistance.SOLUTION: A member for composite materials contains a resin component primarily composed of polyphenylene sulfide. The resin component has a melt viscosity of 250 Pa s or more and 2000 Pa s or less and a relative crystallinity of 90% or less. The composite material contains resin and reinforced fiber.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a member for a composite material made of polyphenylene sulfide that can be applied to composite materials in electric and electronic devices, automobiles, aircraft, etc., a composite material using this member for a composite material, and a moving body. The present invention also relates to a method for manufacturing a composite material and a method for manufacturing a film.

Background Art

[0002] Polyphenylene sulfide (hereinafter sometimes abbreviated as "PPS") has properties such as high heat resistance, excellent mechanical strength, flame retardancy, chemical resistance, dimensional stability, electrical properties, and injection moldability. Therefore, it is widely used in automotive parts, electric and electronic parts, precision mechanical parts, etc.

[0003] Generally, composite materials of PPS are manufactured using the powder method using resin powder, but there are problems such as instability in the volume content rate in the reinforcing fiber. Furthermore, compared with other super engineering plastics such as PEEK (polyether ether ketone) and PEI (polyether imide), PPS has low toughness and its applications are limited.

[0004] In Patent Document 1, a composite material is disclosed in which polyphenylene sulfide is used as a matrix and the electrostatic charge amount with respect to polyethylene is suppressed to improve the moldability by the powder method.

Prior Art Documents

Patent Documents

[0005] <J

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, since the manufacturing method described in Patent Document 1 employs a powder method, the powder does not sufficiently impregnate the reinforcing fibers, which tends to result in many voids.

[0007] This invention was made under such circumstances, and aims to provide a composite material component that is resistant to breakage, has excellent handling properties, exhibits excellent impregnation and heat-sealing properties with carbon fibers during composite material molding, and provides a composite material with excellent flame retardancy, water absorption resistance, and a good balance of strength and impact resistance after composite material molding. [Means for solving the problem]

[0008] The present invention provides, as a means to solve the problems of the prior art, a composite material component using polyphenylene sulfide having a specific melt viscosity.

[0009] In other words, the present invention provides the following [1] to

[14] .

[0010] [1] A composite material component comprising a resin component mainly composed of polyphenylene sulfide, wherein the melt viscosity of the resin component is 250 Pa·s or more and 2000 Pa·s or less, the relative crystallinity is 90% or less, and the composite material is a composite material comprising resin and reinforcing fibers. [2] The composite material component according to [1], wherein the content of polyphenylene sulfide in the resin component is 70% by mass or more.

[0011] [3] The composite material member according to [1] or [2], wherein the non-Newton coefficient of the resin component is 1.0 or more and 2.5 or less. [4] The composite material component according to any one of [1] to [3], wherein the melt viscosity of the polyphenylene sulfide is 250 Pa·s or more and 2000 Pa·s or less.

[0012] [5] A composite material member according to any one of [1] to [4], wherein the non-Newton coefficient of the polyphenylene sulfide is 1.0 or more and 2.5 or less. [6] A composite material component according to any of [1] to [5], wherein the heat of fusion of the crystals is 30 J / g or more and 55 J / g or less.

[0013] [7] A composite material component, which is a film, as described in any of [1] to [6]. [8] A composite material obtained by combining a composite material component described in any of [1] to [7] with reinforcing fibers. [9] The composite material described in [8], which is a prepreg. A mobile body, such as an aircraft, automobile, ship, or railway vehicle, made of the composite material described in

[10] [8] or [9].

[11] A method for manufacturing a composite material, comprising compounding a composite material component described in any of [1] to [7] with reinforcing fibers.

[0014]

[12] The method for manufacturing a composite material according to

[11] , wherein the composite material is a prepreg.

[13] A method for producing a film containing a resin component mainly composed of polyphenylene sulfide, wherein a resin component having a melt viscosity of 250 Pa·s or more and 2000 Pa·s or less is prepared, melted and kneaded in an extruder, the molten resin is extruded from a die, and the molten resin is cooled with a cast roll to produce a film with a relative crystallinity of 90% or less.

[0015]

[14] The method for producing a film according to

[13] , wherein the melt viscosity of the polyphenylene sulfide is 250 Pa·s or more and 2000 Pa·s or less. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a composite material component that is resistant to breakage, has excellent handling properties, exhibits excellent impregnation and heat-sealing properties with carbon fibers during composite material molding, and provides a composite material with excellent flame retardancy, water absorption resistance, and a good balance of strength and impact resistance after composite material molding. [Brief explanation of the drawing]

[0017] [Figure 1] It is a main part explanatory drawing schematically showing an embodiment of a method for manufacturing a film.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, an example of an embodiment of the present invention will be described. However, the present invention is not limited to the embodiments described below as long as it does not exceed the gist thereof.

[0019] In the present invention, when expressed as "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, it includes the meaning of "X or more and Y or less", and also includes the meaning of "preferably greater than X" and "preferably less than Y". Also, in the present invention, when expressed as "X or more" (X is an arbitrary number), unless otherwise specified, it includes the meaning of "preferably greater than X", and when expressed as "Y or less" (Y is an arbitrary number), unless otherwise specified, it includes the meaning of "preferably less than Y".

[0020] In the present invention, the "main component" refers to the most abundant component in the object, preferably 50% by mass or more in the object, more preferably 60% by mass or more, still more preferably 70% by mass, particularly preferably 80% by mass or more, most preferably 90% by mass or more, and may be 100% by mass.

[0021] A member for a composite material (hereinafter sometimes referred to as "this member"), which is an embodiment of the present invention, is a member for a composite material containing a resin component containing polyphenylene sulfide as a main component, wherein the melt viscosity of the resin component is 250 Pa·s or more and 2000 Pa·s or less, and the relative crystallinity is 90% or less, and the composite material is a composite material containing a resin and reinforcing fibers. The following will be described in detail.

[0022] <Resin component> The resin component contained in this material mainly consists of polyphenylene sulfide, and there are no particular restrictions as long as its melt viscosity is between 250 Pa·s and 2000 Pa·s.

[0023] The polyphenylene sulfide has a repeating unit represented by the following structural formula (1). The repeating unit consists of a benzene ring with a sulfur atom attached. n is a positive number, preferably 80 to 1000, more preferably 100 to 700, and even more preferably 150 to 500.

[0024] [ka]

[0025] The content of polyphenylene sulfide in the resin component is preferably 70% by mass or more, more preferably 75% by mass or more, even more preferably 80% by mass or more, particularly preferably 85% by mass or more, and most preferably more than 90% by mass. When a resin other than polyphenylene sulfide is included, as long as the content of polyphenylene sulfide is within this range, it becomes easy to impart the necessary effects while maintaining the effects of the present invention.

[0026] When blending polyphenylene sulfide with other resin components for the purpose of modifying the resin component, the type is not particularly limited, and polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polymethylpentene, polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, polyacetal, aliphatic polyamide, polymethyl methacrylate, polycarbonate, ABS, aromatic polyamide, polyarylate, polyetherimide, polyamideimide, polysulfone, polyethersulfone, polyaryletherketone, liquid crystal polymers, copolymers thereof, and mixtures thereof can be used.

[0027] The melt viscosity of the resin component, particularly polyphenylene sulfide, is 250 Pa·s or higher, preferably 275 Pa·s or higher, more preferably 300 Pa·s or higher, even more preferably 320 Pa·s or higher, particularly preferably 340 Pa·s or higher, especially preferably 360 Pa·s or higher, and most preferably 370 Pa·s or higher. If the melt viscosity is above the lower limit, sufficient strength can be maintained. On the other hand, the melt viscosity of the resin component is 2000 Pa·s or lower, preferably 1500 Pa·s or lower, more preferably 1000 Pa·s or lower, and even more preferably 700 Pa·s or lower. Having a melt viscosity below the upper limit has the advantage of excellent moldability.

[0028] The melt viscosity is calculated at a temperature of 300°C and a shear rate of s. -1 This refers to the melt viscosity in [the specified region], and can be measured under the measurement conditions described in the examples below.

[0029] The non-Newton coefficient of the resin component, particularly polyphenylene sulfide, is preferably 2.5 or less, more preferably 2.4 or less, even more preferably 2.3 or less, even more preferably 2.2 or less, even more preferably 2.1 or less, even more preferably 2.0 or less, even more preferably 1.9 or less, even more preferably 1.8 or less, even more preferably 1.7 or less, even more preferably 1.6 or less, especially preferably 1.5 or less, especially preferably 1.4 or less, and most preferably 1.3 or less. If the non-Newton coefficient is below the above upper limit, the toughness and impact resistance are excellent. On the other hand, there is no particular limit to the lower limit of the non-Newton coefficient of the resin component, but it is usually 1.0 or more, and preferably 1.1 or more. If the non-Newton coefficient is above the above lower limit, the toughness and impact resistance tend to be excellent.

[0030] The non-Newton coefficient can be measured under the measurement conditions described in the examples below.

[0031] The crystal melting temperature (Tm) of the resin component, particularly polyphenylene sulfide, is preferably 270°C or higher, more preferably 271°C or higher, even more preferably 272°C or higher, and particularly preferably 273°C or higher. If the crystal melting temperature of polyphenylene sulfide is above the lower limit, the resulting composite material component tends to have excellent heat resistance. On the other hand, the crystal melting temperature of the resin component, particularly polyphenylene sulfide, is preferably 300°C or lower, more preferably 299°C or lower, even more preferably 297°C or lower, particularly preferably 295°C or lower, and most preferably 290°C or lower. If the crystal melting temperature of the resin component, particularly polyphenylene sulfide, is below the upper limit, the fluidity during melt molding, such as during the manufacture of the composite material component, tends to be excellent.

[0032] The crystal melting temperature can be measured under the measurement conditions described in the examples below.

[0033] The heat of fusion (ΔHm) of the resin component, particularly polyphenylene sulfide, is preferably 35 J / g or more, more preferably 36 J / g or more, even more preferably 37 J / g or more, and particularly preferably 38 J / g or more. If the heat of fusion of the resin component, particularly polyphenylene sulfide, is above the lower limit, the resulting composite material component will have sufficient crystallinity, and consequently the resulting composite material will tend to have excellent heat resistance and rigidity. On the other hand, the heat of fusion of the resin component, particularly polyphenylene sulfide, is preferably 55 J / g or less, more preferably 52 J / g or less, and even more preferably 50 J / g or less. If the heat of fusion of the resin component, particularly polyphenylene sulfide, is below the upper limit, the crystallinity will not be too high, resulting in excellent melt moldability during the manufacture of the composite material component, and the resulting composite material will tend to have excellent durability and impact resistance.

[0034] If multiple crystal melting peaks exist, their total heat values ​​will be calculated as ΔHm, and the heat of crystal melting can be measured under the measurement conditions described in the examples below.

[0035] The crystallization temperature (Tc) of the resin component, particularly polyphenylene sulfide, during the cooling process is preferably 200°C or higher, more preferably 202°C or higher, even more preferably 204°C or higher, particularly preferably 206°C or higher, and most preferably 208°C or higher. If the crystallization temperature of the resin component, particularly polyphenylene sulfide, during the cooling process is above the lower limit, the crystallization rate is high, and the productivity of composite material components tends to be excellent. Specifically, for example, when making a film, by setting the cast roll to a temperature above the glass transition temperature and below the crystal melting temperature, crystallization is promoted while the resin is in contact with the cast roll, and a crystallized film is obtained. However, if the crystallization temperature during the cooling process is above the lower limit, the crystallization rate is high, and crystallization can be completed on the cast roll, resulting in a higher elastic modulus, which in turn suppresses adhesion to the roll and tends to improve the appearance of the film.

[0036] On the other hand, the crystallization temperature (Tc) of the resin component, particularly polyphenylene sulfide, during the cooling process is preferably 255°C or lower, more preferably 253°C or lower, even more preferably 251°C or lower, and particularly preferably 250°C or lower. If the crystallization temperature during the cooling process is below the above upper limit, crystallization does not proceed too quickly, resulting in less uneven cooling during the molding of composite material components such as films, and a tendency to obtain high-quality composite material components with uniform crystallization.

[0037] The crystallization temperature during the cooling process can be measured using the measurement conditions described in the examples below.

[0038] The method for producing the resin component used in this material, particularly polyphenylene sulfide, is not particularly limited and can be produced by known methods. In production, the conditions for achieving the desired melt viscosity and non-Newton coefficient can be appropriately selected and adopted. Specifically, for example, this could involve adjusting the type, amount, and concentration of monomers, polymerization initiators, catalysts, and chain transfer agents added during polymerization, as well as the method of adding each, or adjusting polymerization conditions such as polymerization temperature, polymerization time, and polymerization pressure. Alternatively, so-called multi-stage polymerization, in which polymerization is carried out by changing the polymerization conditions in stages, may also be employed.

[0039] <Components for composite materials> A resin component containing polyphenylene sulfide as its main component, with a melt viscosity of 250 Pa·s to 2000 Pa·s and a relative crystallinity of 90% or less, can be suitably used as a composite material component (this component) for obtaining a composite material containing resin and fibers (reinforcing fibers) to strengthen the resin. In particular, it can be suitably used as a composite material component containing resin and reinforcing fibers with a number average fiber length of 5 mm or more. This component, in particular, by containing the resin component having the specific melt viscosity and relative crystallinity described above, especially polyphenylene sulfide, tends to have excellent impregnation properties for reinforcing fibers. This advantage due to the inclusion of polyphenylene sulfide is especially pronounced when composited with reinforcing fibers that have a number average fiber length of 5 mm or more.

[0040] This component may contain various additives such as heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, antibacterial and antifungal agents, antistatic agents, lubricants, pigments, dyes, and fillers, to the extent that they do not impair the effects of the present invention (for example, in a range of less than 5% by mass of this component).

[0041] Furthermore, since this component is a material used to obtain a composite material by impregnating it with fibers for reinforcing the resin, it is preferable that this component does not contain fibers for reinforcing the resin (reinforcing fibers).

[0042] The proportion of resin components in this member, particularly polyphenylene sulfide, is preferably 35% by mass or more, more preferably 40% by mass or more, even more preferably 50% by mass or more, particularly preferably 60% by mass or more, especially preferably 70% by mass or more, and most preferably 80% by mass or more. If the proportion of resin components, particularly polyphenylene sulfide, contained in this member is above the lower limit, the member is likely to have excellent heat resistance and chemical resistance. On the other hand, there is no particular limit on the upper limit, and in order to fully exhibit properties such as heat resistance and chemical resistance, it is preferable that the proportion of resin components, particularly polyphenylene sulfide, be as high as possible. However, if additives, fillers, etc., are further included for the purpose of modifying the resin components, particularly polyphenylene sulfide, the proportion is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less. If the proportion of resin components, particularly polyphenylene sulfide, contained in this member is below the upper limit, the effects of additives, fillers, etc., when further included, are likely to be fully exhibited.

[0043] [Melting viscosity] The melt viscosity of the resin component of this member is 250 Pa·s or higher, preferably 275 Pa·s or higher, more preferably 300 Pa·s or higher, even more preferably 320 Pa·s or higher, particularly preferably 340 Pa·s or higher, especially preferably 360 Pa·s or higher, and most preferably 380 Pa·s or higher. If the melt viscosity is above the lower limit, sufficient strength can be maintained. On the other hand, the melt viscosity of the resin component of this member is 2000 Pa·s or lower, preferably 1000 Pa·s or lower, more preferably 900 Pa·s or lower, and even more preferably 700 Pa·s or lower. Having a melt viscosity below the upper limit has the advantage of excellent moldability. The melt viscosity is calculated at a temperature of 300°C and a shear rate of s. -1 This refers to the melt viscosity in [the specified region], and can be measured under the measurement conditions described in the examples below.

[0044] [Relative crystallinity] The relative crystallinity of the resin component of this member is 90% or less, preferably 80% or less, more preferably 70% or less, even more preferably 60% or less, particularly preferably 50% or less, especially preferably 40% or less, and most preferably 35% or less. If the relative crystallinity of the resin component of the composite material member is below the above upper limit, it is possible to make a composite material member that has excellent heat fusion between the resin and reinforcing fibers, is resistant to breakage, and has excellent handling properties. Since this member is resistant to breakage, for example, there is less breakage loss in the trimming process during molding, which leads to improved yield and, i.e., improved productivity. On the other hand, the relative crystallinity of the resin component of the composite material member is usually 10% or more, preferably 15% or more. Having a relative crystallinity of 10% or more does not significantly impair the elastic modulus, thus providing the advantage of excellent handling properties. The relative crystallinity can be measured using the measurement conditions described in the examples below.

[0045] [Non-Newton coefficients] The non-Newton coefficient of the resin component of this member is preferably 2.5 or less, more preferably 2.4 or less, even more preferably 2.3 or less, even more preferably 2.2 or less, even more preferably 2.1 or less, even more preferably 2.0 or less, even more preferably 1.9 or less, even more preferably 1.8 or less, even more preferably 1.7 or less, even more preferably 1.6 or less, especially preferably 1.5 or less, particularly preferably 1.4 or less, and most preferably 1.3 or less. If the non-Newton coefficient is below the above upper limit, there is less cross-linking structure and the toughness tends to improve. On the other hand, there is no particular limit to the lower limit of the non-Newton coefficient of the resin component of this member, but it is usually 1.0 or more, and preferably 1.1 or more. If the non-Newton coefficient is above the above lower limit, the toughness and impact resistance tend to be excellent. The non-Newton coefficient can be measured under the measurement conditions described in the examples below.

[0046] [Crystal melting temperature (Tm)] The crystal melting temperature of the resin component of this member is preferably 270°C or higher, more preferably 271°C or higher, even more preferably 272°C or higher, and particularly preferably 273°C or higher. If the crystal melting temperature of this member is above the lower limit, it tends to have excellent heat resistance. On the other hand, the crystal melting temperature is preferably 300°C or lower, more preferably 299°C or lower, even more preferably 297°C or lower, particularly preferably 295°C or lower, and most preferably 290°C or lower. If the crystal melting temperature of the resin component of the composite material member is below the upper limit, it tends to have excellent secondary processing properties, such as impregnation into fibers, when manufacturing a composite material with reinforcing fibers using the composite material member. The crystal melting temperature of the resin component of the composite material can be measured using the measurement conditions described in the examples below.

[0047] [Heat of fusion (ΔHm)] The heat of fusion of the resin component of this member is preferably 30 J / g or more, more preferably 31 J / g or more, even more preferably 32 J / g or more, and particularly preferably 33 J / g or more. If the heat of fusion of the resin component of this member is above the lower limit, it tends to have excellent heat resistance and rigidity. Furthermore, even after being made into a composite material with reinforcing fibers, it tends to have excellent heat resistance and rigidity. On the other hand, the heat of fusion of the resin component of this member is preferably 55 J / g or less, more preferably 52 J / g or less, and even more preferably 50 J / g or less. If the heat of fusion of the resin component of this member is below the upper limit, the degree of crystallinity is not too high, and it tends to have excellent secondary processing properties, such as impregnation into reinforcing fibers when manufacturing a composite material with reinforcing fibers. If multiple crystal melting peaks exist, their sum is calculated as ΔHm, and the heat of crystal melting of the film can be measured under the measurement conditions described in the examples below.

[0048] [Crystallization temperature (Tc)] The crystallization temperature of the resin component of this material during the cooling process is preferably 200°C or higher, more preferably 202°C or higher, even more preferably 204°C or higher, particularly preferably 206°C or higher, and most preferably 208°C or higher. If the crystallization temperature of this material during the cooling process is above the lower limit, the crystallization rate is high, and the productivity of composite material components tends to be excellent. Specifically, for example, when making a film, by setting the cast roll to a temperature above the glass transition temperature and below the crystallization melting temperature, crystallization is promoted while the resin is in contact with the cast roll, and a crystallized film is obtained. However, if the crystallization temperature during the cooling process is above the lower limit, the crystallization rate is high, and crystallization can be completed on the cast roll, resulting in a higher elastic modulus, which in turn suppresses adhesion to the roll and tends to improve the appearance of the film.

[0049] On the other hand, the crystallization temperature of the resin component of this material during the cooling process is preferably 255°C or lower, more preferably 253°C or lower, even more preferably 251°C or lower, and particularly preferably 250°C or lower. If the crystallization temperature during the cooling process is below the above upper limit, crystallization does not proceed too quickly, resulting in less uneven cooling during the molding of composite material components such as films, and a tendency to obtain high-quality composite material components with uniform crystallization.

[0050] The crystallization temperature of the resin component of this material during the cooling process can be measured using the measurement conditions described in the examples below.

[0051] [Tensile elongation at breaking] The tensile elongation at break of this component is more preferably 80% or more, even more preferably 100% or more, and particularly preferably 120% or more. Within the range of the tensile elongation at break, the composite material component will be less prone to breakage and have excellent handling properties. The tensile elongation at break can be measured under the measurement conditions described in the examples below. There is no specific upper limit for the tensile elongation at break, but it is usually 500% or less.

[0052] [Softening temperature] The softening temperature of this component is preferably 40°C or higher, more preferably 60°C or higher, even more preferably 80°C or higher, and particularly preferably 90°C or higher. If the softening temperature of this component is above the lower limit, it tends to have excellent heat resistance. On the other hand, the softening temperature is preferably 200°C or lower, more preferably 180°C or lower, even more preferably 150°C or lower, particularly preferably 120°C or lower, and most preferably 95°C or lower. Within the range of the softening temperature, it tends to have excellent moldability during composite material molding. The softening temperature can be measured using the measurement conditions described in the examples below.

[0053] The shape of the component is not particularly limited and may be any shape such as film, plate, fiber, bottle, tube, or rod, but it is preferably a film, plate, or fiber, more preferably a plate-like shape such as a film or plate, and even more preferably a film. In the case of a plate-like component, "plate-like" refers to any flat shape with an arbitrary maximum thickness, and includes not only so-called plates with a thickness of 1 mm or more, but also films with a thickness of less than 1 mm. A thin plate-like shape is preferred for the plate-like component, with a thickness of 2 mm or less preferred, more preferably less than 1 mm, even more preferably 500 μm or less, particularly preferably 400 μm or less, especially preferably 300 μm or less, and most preferably 250 μm or less. The lower limit is usually 3 μm. Furthermore, if the material has a different shape, it can be formed into various shapes, preferably into films, plates, or other components, by general molding methods, such as extrusion molding, injection molding, casting methods including molten casting, and press molding. In each molding method, the apparatus and processing conditions are not particularly limited, and known methods can be used. In particular, from the viewpoint of processability when forming a composite material with reinforcing fibers as described later, it is preferable that the composite material component be a film formed by extrusion molding, especially by the T-die method.

[0054] In this invention, "film" encompasses "sheet." Generally, a film is a thin, flat product with a thickness that is extremely small compared to its length and width, and whose maximum thickness is arbitrarily limited, and which is usually supplied in roll form (Japanese Industrial Standard JIS K6900:1994). Generally, a sheet, according to the definition in JIS, is a thin, flat product whose thickness is generally small relative to its length and width. However, since the boundary between sheet and film is not clear, in this invention, "film" encompasses "sheet." Therefore, "film" may also be "sheet."

[0055] <Method for manufacturing components for composite materials> The manufacturing method for a composite material component (the component), particularly a film (hereinafter sometimes referred to as "the film"), which is one embodiment of the present invention, is not particularly limited, but can be obtained, for example, as an unstretched or stretched film. From the viewpoint of secondary processability when manufacturing composite materials, it is preferable to obtain it as an unstretched film. An unstretched film is a film that is not actively stretched for the purpose of controlling the orientation of the film, and includes films that are oriented when taken up by a cast roll in extrusion molding such as the T-die method, and films in which the stretching ratio on the stretching roll is less than 2 times.

[0056] This film can be manufactured by melt-kneading the constituent materials in an extruder, then extruding and cooling them. Known kneaders, such as single-screw or twin-screw extruders, can be used for melt-kneading.

[0057] This invention discloses an example of a method for producing a film containing polyphenylene sulfide as the main component of the resin. Specifically, this manufacturing method involves preparing a resin component with a melt viscosity of 250 Pa·s or more and 2000 Pa·s or less, melting and kneading it in an extruder, extruding the molten resin from a die, and cooling the molten resin with a cast roll to produce a film with a relative crystallinity of 90% or less.

[0058] In the above-described manufacturing method, it is preferable that the melt viscosity of the polyphenylene sulfide is 250 Pa·s or more and 2000 Pa·s or less.

[0059] Furthermore, the present invention also discloses a method for manufacturing this film in which the heat of fusion (ΔHm) of the film after cooling is 30 J / g or more and 55 J / g or less.

[0060] In order to produce a film with a heat content of 30 J / g or more and 55 J / g or less as described above, the selection of polyphenylene sulfide used as a raw material and the conditions for extruding the film can be appropriately adjusted, but in the present invention, it is preferable to adopt the following methods (1) to (4).

[0061] (1) The polyphenylene sulfide used as a raw material shall have a melt viscosity of 250 Pa·s or more and 2000 Pa·s or less. Further details regarding the physical properties of the polyphenylene sulfide are the same as those for the polyphenylene sulfide used in the composite material components described above, so the explanation is omitted here.

[0062] (2) Adjust the melting and mixing temperature in the extruder. The melting temperature is adjusted as appropriate depending on the type of resin, the mixing ratio, and the presence and type of additives, but from the viewpoint of productivity, it is preferably 260°C or higher, more preferably 270°C or higher, even more preferably 280°C or higher, and particularly preferably 290°C or higher. By setting the resin temperature above the lower limit, the crystals of raw materials such as pellets melt sufficiently and are less likely to remain in the film, so the tensile elongation at break of the film tends to improve. On the other hand, the melting temperature is preferably 350°C or lower, more preferably 340°C or lower, even more preferably 330°C or lower, and particularly preferably 320°C or lower. By setting the resin temperature below the upper limit, the resin is less likely to decompose during melt molding and the molecular weight is more easily maintained, so the tensile elongation at break of the film tends to improve.

[0063] (3) Adjust the cooling conditions when cooling the molten resin to form a film. Cooling can be performed, for example, by using a cast roll as a cooling machine and bringing the extruded molten resin into contact with the cast roll, but it is preferable to adopt the following methods (3-1) and (3-2).

[0064] (3-1) Adjust the temperature of the cast roll. When producing a film that is not fully crystallized, for example, a film with a relative crystallinity of 90% or less, it is important to rapidly cool the molten state to below the glass transition temperature to reduce the molecular mobility to a region where crystals cannot grow. In this case, the cooling temperature (e.g., the cast roll temperature) is preferably 30°C or higher, more preferably 50°C or higher, and even more preferably 70°C or higher. On the other hand, the cooling temperature (cast roll temperature) is preferably 100°C or lower, and more preferably 90°C or lower.

[0065] (3-2) Adjust the time from when the molten resin is extruded from the die until the start of cooling. This time can be adjusted, for example, by the distance from the die to the cast roll. By shortening this distance, the time from when the molten resin is extruded until the start of cooling can be shortened, while by lengthening this distance, the start of cooling can be delayed. The distance should be adjusted appropriately considering the temperature of the extruded molten resin, the temperature of the cast roll, etc., but the distance is preferably 5 mm or more, more preferably 7 mm or more, even more preferably 10 mm or more, preferably 100 mm or less, more preferably 70 mm or less, and even more preferably 50 mm or less.

[0066] (4) When using a cast roll, the contact angle θ when bringing the molten resin into contact with the cast roll is adjusted. Instead of dropping the molten resin perpendicularly to the contact point between the cast roll and the pressure roll, as shown in Figure 1, the die 1 is slightly shifted toward the center of the cast roll 4, and the molten resin is dropped from the nozzle 2 of the die 1 into contact with the cast roll 4. This makes it less likely for problems such as waviness and wrinkles to occur when the molten resin is cooled and formed into a film shape, and makes it easier to obtain a uniformly crystallized film 5. The contact angle θ is the angle formed by the straight line connecting the contact point between the pressure roll 3 and the cast roll 4 and the nozzle 2, and the vertical line from the contact point (dotted line in Figure 1), as shown in Figure 1. θ is preferably 1° or more, more preferably 2° or more, even more preferably 3° or more, preferably 10° or less, more preferably 8° or less, and even more preferably 5° or less.

[0067] Furthermore, there are no particular limitations on the method for adjusting the surface roughness of the component, especially the film. For example, in the casting process to obtain the component by transfer treatments such as embossing roll transfer, embossing belt transfer, and embossing film transfer, sandblasting, shot blasting, etching, engraving, surface crystallization, or by coating, drying, and heat-treating the resin component on a support, various methods can be used, such as adjusting the surface roughness of the metal roll, endless metal belt, polymer film, etc. used as the support by polishing. Among these, a method of adjusting to the desired roughness by casting the film-like molten resin onto a roll such as a cast roll is preferred because it is easy to continuously and uniformly adjust the surface roughness while extruding the molten resin into a film. In this case, the surface roughness of the resin film can be adjusted by adjusting the surface roughness, such as the arithmetic mean roughness of the cast roll.

[0068] Furthermore, there are no particular restrictions on the method for adjusting the thickness accuracy of this component to a desired range. For example, if this component is a film, extrusion molding can be employed, and the conditions for extruding the film can be appropriately adjusted. Specifically, for example, (1) A method of adjusting the lip opening by mechanically rotating the lip bolt of a die such as a T-die. (2) A method of adjusting the film thickness by attaching heating devices to the die lip at regular intervals and individually adjusting their temperatures, thereby utilizing the temperature change of the viscosity of the molten resin. (3) A method for adjusting the distance between the die and the cast roll so as to minimize vibration and pulsation of the molten resin extruded into a film. (4) A method of blocking the airflow by installing a plate or cover so that the molten resin extruded in film form does not pulsate due to the flow of gases such as surrounding air when it comes into contact with the cast roll. (5) A method for adjusting the discharge volume so as not to fluctuate when extruding in film form. (6) A method to reduce the rotational fluctuation rate of the cast roll and suppress unevenness in the roll's rotation. (7) A static charge is applied to the molten resin extruded into a film shape by an electrode to which a high voltage is applied, A method of attaching a cast roll using electrostatic force (electrostatic adhesion method). (8) A method of blowing compressed air in a curtain shape onto molten resin extruded into a film and making it adhere to a cast roll. (9) A method in which the molten resin extruded into a film is brought into close contact with a cast roll by a nip roll is one example.

[0069] When this component is used in film form, there are no particular restrictions on the film thickness, but it is usually 3 μm or more, preferably 6 μm or more, more preferably 9 μm or more, even more preferably 12 μm or more, even more preferably more than 15 μm, even more preferably 18 μm or more, especially preferably 21 μm or more, particularly preferably 25 μm or more, and most preferably 30 μm or more. On the other hand, the film thickness is preferably 500 μm or less, more preferably 450 μm or less, even more preferably 400 μm or less, even more preferably 350 μm or less, particularly preferably 300 μm or less, particularly preferably 250 μm or less, and most preferably 200 μm or less. Within this range of film thickness, the thickness is neither too thin nor too thick, resulting in a balance of mechanical properties, film-forming properties, insulation properties, etc., and a tendency towards excellent secondary processing when compounded with reinforcing fibers. The thickness of the film can usually be measured using a caliper or similar tool.

[0070] Furthermore, if the component is a film, it can be a multilayer film with other layers laminated on it, as long as the effects of the present invention are not impaired. For example, known methods such as co-extrusion, extrusion lamination, thermal lamination, and dry lamination can be used for multilayering.

[0071] This component, and in particular this film, is resistant to breakage and has excellent handling properties. Furthermore, during composite material molding, it exhibits excellent impregnation and heat-sealing properties with carbon fibers, making it suitable as a material for composites of resin and reinforcing fibers, especially reinforcing fibers with a number average fiber length of 5 mm or more. In addition, the component obtained by the manufacturing method of the present invention, particularly the composite material obtained by compounding the film with reinforcing fibers, has excellent flame retardancy, water absorption resistance, and a good balance of strength and impact resistance. Therefore, it can be suitably used in mobile objects such as aircraft, automobiles, ships, or railway vehicles, as well as in sporting goods, home appliances, and building materials. In particular, it is industrially useful as a component of mobile objects such as aircraft, automobiles, ships, or railway vehicles.

[0072] [Method for manufacturing composite materials] This component is resistant to breakage, has excellent handling properties, and exhibits excellent impregnation and heat-sealing properties with carbon fibers during composite material molding. Therefore, it can be used as a component for composite materials of resin and reinforcing fibers (especially reinforcing fibers with a number average fiber length of 5 mm or more). In particular, this component can be suitably used as a component for composite materials when it is in the form of a film. In other words, this component can be combined with reinforcing fibers to create a composite material. The manufacturing method for this composite material will be described in detail below.

[0073] The types of reinforcing fibers are not particularly limited, but examples include inorganic fibers such as carbon fibers, glass fibers, boron fibers, and alumina fibers; organic fibers such as liquid crystal polymer fibers, polyethylene fibers, aramid fibers, and poly(p-phenylenebenzoxazole) fibers; and metallic fibers such as aluminum fibers, magnesium fibers, titanium fibers, SUS fibers, copper fibers, and metal-coated carbon fibers. Among these, carbon fibers are preferred from the viewpoint of rigidity and lightness.

[0074] Carbon fibers include polyacrylonitrile (PAN)-based, petroleum / coal pitch-based, rayon-based, and lignin-based types, and any of these carbon fibers can be used. In particular, PAN-based carbon fibers made from PAN as a raw material, with strands or tows of 12,000 to 48,000 filaments, are preferred due to their excellent productivity and mechanical properties on an industrial scale.

[0075] The number-average fiber length is preferably 5 mm or more, more preferably 10 mm or more, more preferably 20 mm or more, more preferably 30 mm or more, particularly preferably 40 mm or more, and most preferably 50 mm or more. It is also preferable that the reinforcing fibers are continuous fibers. Setting the number-average fiber length to be above the lower limit tends to make it easier to obtain sufficient mechanical properties for the resulting composite material. There is no particular upper limit to the number-average fiber length, but in the case of discontinuous fibers such as woven fabrics, knitted fabrics, or nonwoven fabrics as described later, the number-average fiber length is preferably 500 mm or less, more preferably 300 mm or less, and even more preferably 150 mm or less. Setting the number-average fiber length to be below the upper limit tends to make it easier to ensure sufficient filling of the reinforcing fibers into the complex-shaped parts when forming the final product, especially the complex-shaped final product, using the composite material, and to suppress the occurrence of strength reduction in those parts. The number-average fiber length of reinforcing fibers refers to the average length of the longest observed portion of the reinforcing fibers when observed using an electron microscope such as a scanning electron microscope or an optical microscope. Specifically, it can be determined by observing a cross-section in the composite material where the length direction of the reinforcing fibers can be observed, and then number-averaging the measured fiber lengths. Another method involves dispersing reinforcing fibers, from which the resin component has been removed using a solvent, in a suitable dispersant, laminating the resulting dispersion into a thin film, and then determining the number-average fiber length using image processing software based on an image of the reinforcing fibers captured with a scanner or the like.

[0076] The shape of the reinforcing fibers is not particularly limited, and can be appropriately selected as needed from among fiber bundles such as chopped strands and rovings, woven fabrics such as plain weave and twill weave, knitted fabrics, nonwoven fabrics, fiber paper, and UD materials (unidirectional materials) that form reinforcing fiber sheets.

[0077] There are no particular limitations on the method of compounding the reinforcing fibers with the main component. By employing conventionally known methods such as resin film impregnation (film stacking method), blending method, melting method, solvent method, dry powder coating method, powder suspension method, etc., composite materials such as prepregs can be manufactured by impregnating or semi-impregnating reinforcing fiber bundles or reinforcing fiber sheets with the main component. In the present invention, among these, the resin film impregnation method (film stacking method) is preferred.

[0078] Specifically, a prepreg can be formed by layering the component onto one or both sides of the aforementioned reinforcing fiber sheet and then heating and pressurizing it to melt and impregnate the resin component of the component into the reinforcing fiber sheet. In this case, by adjusting the heating and pressurizing conditions, a prepreg with a controlled amount of voids can be obtained. It should be noted that the prepreg also includes a form in which the component is temporarily bonded to the reinforcing fiber sheet by heat fusion, without the pressurizing process. A prepreg temporarily bonded in this way, especially one containing many voids, has the advantage of shortening the manufacturing time and reducing manufacturing costs, as well as being flexible and easily deformable to conform to the actual shape. The above method can be suitably used when the component is a film.

[0079] By subjecting this prepreg to known processes such as autoclave molding, infusion molding, heat and cool press molding, stamping molding, and automated lamination molding by robot, composite material products can be obtained, and the molding conditions can be selected according to the amount of voids contained. The main components such as films used in the production of the prepreg require secondary processing properties such as impregnation and heat-fusibility into reinforcing fiber sheets. In particular, because this composite material contains polyphenylene sulfide, increasing the crystallinity of the resin component results in a composite material with an excellent balance of strength and impact resistance, as well as superior flame retardancy and water absorption resistance.

[0080] To increase the crystallinity of the resin component (for example, to a relative crystallinity of 100%), it is necessary to heat the prepreg obtained by the method described above. The heating may be done during the manufacturing of the composite material such as the prepreg, or the prepreg may be heated in a process such as autoclave molding, but it is preferable to increase the crystallinity by heating during the manufacturing of the composite material.

[0081] The heating temperature is preferably 30 to 150°C higher than the glass transition temperature of the resin component contained in the material, more preferably 35 to 140°C higher, and particularly preferably 40 to 135°C higher. By setting the heating temperature within this range, the relative degree of crystallinity can be increased. In particular, when the resin component includes polyphenylene sulfide, the heating temperature is preferably 120°C or higher, more preferably 130°C or higher, and even more preferably 140°C or higher. On the other hand, it is preferably 300°C or lower, more preferably 270°C or lower, even more preferably 250°C or lower, and particularly preferably 220°C or lower.

[0082] The crystallization rate of polymer materials is thought to be maximized in the temperature range between the glass transition temperature and the crystal melting temperature, based on the balance between the crystal nucleation rate and growth rate. When producing films with high relative crystallinity, the crystallization rate is maximized within the range where the lower and upper limits of the heating temperature apply, making it easier to obtain crystallized films with excellent productivity.

[0083] The heating time is not particularly limited, but is preferably 1 to 120 minutes, more preferably 3 to 60 minutes, and most preferably 6 to 30 minutes.

[0084] The glass transition temperature refers to the value measured in accordance with JIS K7121:2012 using a differential scanning calorimeter (for example, PerkinElmer's "Pyris1 DSC") under conditions of a temperature range of 25 to 300°C and a heating rate of 10°C / min. Furthermore, if multiple glass transition temperatures exist in a mixture of multiple types of resins, the highest glass transition temperature should be considered the glass transition temperature of the resin component, and the cooling temperature should be adjusted accordingly.

[0085] The reinforcing fiber content in the composite material obtained in this way is preferably 20% by volume or more, more preferably 30% by volume or more, and even more preferably 40% by volume or more, from the viewpoint of elastic modulus and strength. On the other hand, the reinforcing fiber content in the composite material is preferably 90% by volume or less, more preferably 80% by volume or less, and even more preferably 70% by volume or less.

[0086] The composite material formed by combining this component with reinforcing fibers can be suitably used in mobile objects such as aircraft, automobiles, ships, and railway vehicles, as well as in sporting goods, home appliances, and building materials, due to its heat resistance, light weight, and mechanical strength. In particular, it is industrially useful as a component of mobile objects such as aircraft, automobiles, ships, and railway vehicles.

[0087] [Tensile elongation at breaking] The tensile elongation at break, a resin property after molding of composite materials, is preferable as high as possible. Specifically, it is preferably 0.1% or higher, more preferably 0.2% or higher, and particularly preferably 0.3% or higher. The upper limit is usually 100%. Within the range of tensile elongation at break, the composite material will have excellent impact resistance.

[0088] [Tensile modulus of elasticity] The tensile modulus of elasticity, a property of the resin after molding of the composite material, is preferable as high as possible. Specifically, it is preferable to have a tensile modulus of 5000 MPa or higher, more preferably 7000 MPa or higher, and even more preferably 8000 MPa or higher. The upper limit is usually 300,000 MPa. Within this range of tensile modulus, the composite material will have excellent strength.

[0089] [Water absorption rate] The water absorption rate of the composite material obtained by combining this member with reinforcing fibers (similarly, the water absorption rate of the resin after molding the composite material) is preferably 0.8% or less, more preferably 0.6% or less, even more preferably 0.4% or less, and particularly preferably 0.2% or less. If it is below the above upper limit, the decrease in strength due to moisture absorption can be suppressed. The water absorption rate can be measured under the measurement conditions described in the examples below.

[0090] [Flame retardant] The flame retardancy of the composite material formed by combining this component with reinforcing fibers (and similarly, the flame retardancy of the resin properties after molding the composite material) was tested with n=5 according to the procedure of the UL94 thin material vertical combustion test, a safety standard of Underwriters Laboratories. Based on the criteria of the UL94 thin material vertical combustion test (UL94VTM), the flame retardancy was evaluated as VTM-0, VTM-1, VTM-2, or non-compliant. This film is preferably VTM-2 or higher, more preferably VTM-1 or higher, and most preferably VTM-0. If it is VTM-0, a film with extremely excellent flame retardancy can be obtained. [Examples]

[0091] The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. In the examples, "%" means by mass basis.

[0092] 1. Fabrication and evaluation of composite material components First, the resin components used in the examples and comparative examples were prepared using the raw material pellets described below. The melt viscosity and non-Newton coefficients of these materials are shown in Table 1 below. PPS1: Polyphenylene sulfide (Melting viscosity: 560 Pa·s, Non-Newton coefficient: 1.25, Heat of fusion (ΔHm): 37 J / g, Crystallization temperature: 226℃) PPS2: Polyphenylene sulfide (Melting viscosity: 480 Pa·s, Non-Newton coefficient: 1.17, Heat of fusion (ΔHm): 42 J / g, Crystallization temperature: 240℃) PPS3: Polyphenylene sulfide (Melting viscosity: 370 Pa·s, Non-Newton coefficient: 1.22, Heat of fusion (ΔHm): 39 J / g, Crystallization temperature: 239°C) PPS4: Polyphenylene sulfide (Melting viscosity: 225 Pa·s, Non-Newton coefficient: 1.23, Heat of fusion (ΔHm): 42 J / g, Crystallization temperature: 238℃) • PEEK: Polyetheretherketone (vestakeep3300G (manufactured by Daicel Evonik)) • PEI: Polyetherimide (Ultem1000 (manufactured by Sabic))

[0093] The raw material pellets were evaluated and measured for various parameters as follows.

[0094] (1) Melt viscosity Regarding the raw material pellets, in accordance with JIS K7199:1999, a capillary rheometer "Capillograph 1D (manufactured by Toyo Seiki Seisakusho Co., Ltd.)" was used at 300°C and a shear rate of 100 s. -1 The melt viscosity was measured.

[0095] (2) Non-Newton coefficients The non-Newton coefficient (N) of the raw material pellets was calculated using the following formula 2 based on the melt viscosity data mentioned above. [Formula 2] ln(SR) = ln(K) + N·ln(SS) (However, SR (unit: 1 / s) is the shear rate, SS (unit: Pa·s) is the shear stress, and K is a constant.)

[0096] (3) Heat of fusion of crystals (ΔHm) For the raw material pellets, the temperature was increased using a PerkinElmer differential scanning calorimeter "Pyris1 DSC" in accordance with JIS K7122:2012, at a temperature range of 25 to 300°C and a heating rate of 10°C / min. The heat of fusion was determined from the area of ​​the melting peak in the detected DSC curve.

[0097] (4) Crystallization temperature (Tc) The raw material pellets were cooled using a PerkinElmer Pyris1 DSC differential scanning calorimeter in accordance with JIS K7121:2012, at a temperature range of 300 to 25°C and a rate of 10°C / min. The crystallization peak temperature of the detected DSC curve was then determined from the peak top temperature.

[0098] [Table 1]

[0099] (Examples 1-3 and Comparative Example 5) The polyphenylene sulfide (PPS) raw material pellets listed in Table 1 were fed into a Φ25 mm co-screw twin-screw extruder, mixed and melted, extruded through a die (T-die), and allowed to cool in close contact with a cast roll (arithmetic mean roughness (Ra) of 0.03 μm, maximum height roughness (Rz) of 0.34 μm). The temperatures of the extruder, conduit, and die (T-die) were set to 300°C, the temperature of the cast roll to 80°C, and the lip clearance of the die lip was adjusted as appropriate to produce an amorphous film with a thickness of 100 μm.

[0100] (Comparative Examples 1-4) The polyphenylene sulfide (PPS) raw material pellets listed in Table 1 were fed into a Φ25 mm co-screw extruder and melted while being kneaded. The extruded material was then extruded through a die (T-die) and allowed to adhere to a cast roll (arithmetic mean roughness (Ra) of 0.03 μm, maximum height roughness (Rz) of 0.34 μm) and cooled. The extruder, conduit, and die (T-die) were kept at 300°C to form a film. The edges of the obtained film were fixed with an aluminum frame and heated in a 200°C oven for 10 minutes to crystallize, resulting in a crystallized film with a thickness of 100 μm.

[0101] (Comparative Examples 6 and 7) The raw material pellets of polyetheretherketone and polyetherimide listed in Table 1 were fed into a Φ40 mm single-screw extruder and melted while being kneaded. The extruded material was then extruded through a die (T-die) and allowed to cool in close contact with a cast roll (arithmetic mean roughness (Ra) of 0.03 μm, maximum height roughness (Rz) of 0.34 μm). The temperatures of the extruder, conduit, and die (T-die) were set to 380°C, the temperature of the cast roll was set to 210°C, and the lip clearance of the die lip was adjusted as appropriate to produce crystallized polyetheretherketone film and amorphous polyetherimide film with a thickness of 100 μm.

[0102] 2. Film Evaluation The films obtained by the above-described method used in the above examples and comparative examples were evaluated for melt viscosity, relative crystallinity, non-Newton coefficient, crystal melting temperature (Tm), heat of fusion (ΔHm), crystallization temperature (Tc), tensile elongation at break, and softening temperature using the method described below. Note that the "longitudinal direction" of the film refers to the direction (MD) in which the film is extruded from the die (T-die), and the direction perpendicular to this within the film plane is referred to as the "transverse direction" (TD).

[0103] (1) Melt viscosity The film obtained by the method described above was subjected to a shear test using a capillary rheometer "Capillograph 1D (manufactured by Toyo Seiki Seisakusho Co., Ltd.)" at 300°C and a shear rate of 100 s in accordance with JIS K7199:1999. -1 The melt viscosity was measured.

[0104] (2) Relative crystallinity The film obtained by the method described above was heated at a heating rate of 10°C / min using a PerkinElmer differential scanning calorimeter "Pyris1 DSC". The relative crystallinity was calculated from the heat energy (J / g) of the crystal melting peak and the heat energy (J / g) of the recrystallization peak obtained at this time using Equation 1 below. If there are multiple recrystallization peaks, the sum of their heat energy is used as ΔHc, and if there are multiple crystal melting peaks, the sum of their heat energy is used as ΔHm. [Formula 1] Relative crystallinity (%) = {1 - (ΔHc / ΔHm)} × 100 ΔHc: Heat energy (J / g) of the recrystallization peak under a 10°C / min heating condition for the film. ΔHm: Heat energy (J / g) at the crystal melting peak under a 10°C / min heating condition for the film.

[0105] (3) Non-Newton coefficients The non-Newton coefficient (N) of the film obtained by the method described above was calculated using the following formula 2 based on the melt viscosity data. [Formula 2] ln(SR) = ln(K) + N·ln(SS) (However, SR (unit: 1 / s) is the shear rate, SS (unit: Pa·s) is the shear stress, and K is a constant.)

[0106] (4) Crystal melting temperature (Tm) The films obtained using the method described above were heated in accordance with JIS K7121:2012 using a PerkinElmer differential scanning calorimeter "Pyris1 DSC" at a temperature range of 25 to 300°C and a heating rate of 10°C / min. The peak top temperature of the melting peak in the detected DSC curve was then determined.

[0107] (5) Heat of fusion of crystals (ΔHm) The film obtained by the method described above was heated in accordance with JIS K7122:2012 using a PerkinElmer differential scanning calorimeter "Pyris1 DSC" at a temperature range of 25 to 300°C and a heating rate of 10°C / min. The heat of fusion was determined from the area of ​​the melting peak in the detected DSC curve.

[0108] (6) Crystallization temperature (Tc) The film obtained by the method described above was cooled using a PerkinElmer differential scanning calorimeter "Pyris1 DSC" in accordance with JIS K7121:2012, at a temperature range of 300 to 25°C and a rate of 10°C / min, and the peak top temperature of the crystallization peak in the detected DSC curve was determined.

[0109] (7) Tensile elongation at break The films obtained using the method described above were measured under conditions of 23°C and a test speed of 200 mm / min, in accordance with JIS K7127:1999.

[0110] (8) Softening temperature The films obtained using the method described above were measured using a TMA / SS6100 (manufactured by Hitachi High-Tech Science Corporation) in accordance with JIS K7196:2012.

[0111] [Table 2]

[0112] 3. Expected physical properties of the resin portion after composite material molding Using the film obtained by the method described above, the physical properties of the resin portion expected after molding of the composite material when combined with carbon fibers were measured. To improve the physical properties of the composite material, assuming a relative crystallinity of 100% for the resin portion expected after composite material formation, the tensile elongation at break, tensile modulus, water absorption rate, and flame retardancy were evaluated using the method described below. The evaluation results are shown in Table 3 below. To achieve a relative crystallinity of 100%, the edges of the film obtained by the method described above are fixed with an aluminum frame and heated in a 200°C oven for 10 minutes to induce crystallization.

[0113] (9) Tensile elongation at break The film with a relative crystallinity of 100% obtained by the method described above was measured in accordance with JIS K7127:1999 at a temperature of 23°C and a test speed of 200 mm / min.

[0114] (10) Tensile modulus For the film with a relative crystallinity of 100% obtained by the method described above, the tensile modulus at 23°C was measured using a "Tensile Compression Tester Model 205" (manufactured by Intesco) at a tensile speed of 5 mm / min.

[0115] (11) Water absorption rate From the film with a relative crystallinity of 100% obtained by the method described above, a test piece with a diameter of 10 cm (thickness of 100 μm) was cut out and used as the measurement sample. In accordance with JIS K7209:2000, the obtained sample was immersed in water at 23°C for 24 hours, and the water absorption rate was measured from the change in mass before and after immersion using Equation 3 below. [Formula 3] Water absorption rate (%) = ((Mass after immersion - Mass before immersion) / Mass before immersion) × 100

[0116] (12) Flame retardant For the films with a relative crystallinity of 100% obtained by the method described above, a combustion test of the cast film was conducted using test specimens measuring 200 mm in length, 50 mm in width, and 0.1 mm in thickness, following the procedure for the UL94 thin material vertical combustion test by Underwriters Laboratories, with n=5 samples. The flame retardancy was evaluated as VTM-0, VTM-1, VTM-2, or non-compliant based on the criteria for the UL94 thin material vertical combustion test (UL94VTM).

[0117] [Table 3]

[0118] The films in Examples 1-3 have a relative crystallinity of 40% or less. These films have a higher tensile elongation at break than shown in Table 2, making them less prone to breakage and easier to handle. Specifically, they are less likely to cause film loss due to breakage during trimming in film formation, thus improving yield. Furthermore, the films of Examples 1 to 3 have low melt viscosity, resulting in excellent carbon fiber impregnation during composite material molding, and also have low softening temperatures, resulting in excellent thermal fusion properties with carbon fibers during composite material molding. Furthermore, the data from Examples 1-3 in Table 3 shows that the composite materials obtained using the films of Examples 1-3 are excellent in flame retardancy and water absorption resistance, and have an excellent balance between strength (tensile modulus) and impact resistance (tensile elongation at break).

[0119] On the other hand, the films of Comparative Examples 1 to 4 have a higher relative crystallinity than shown in Table 2, resulting in a lower tensile elongation at break and making them prone to breakage during composite material molding. Furthermore, their higher softening temperature indicates poor thermal fusion with carbon fibers during composite material molding. Furthermore, it was found that the film of Comparative Example 5 had a melt viscosity of less than 250 Pa·s, a low tensile elongation at break, and was a material that was easily broken. The film obtained from PEEK in Comparative Example 6 has a high crystal melting temperature (Tm) and a high softening temperature, resulting in poor moldability during composite material molding. Furthermore, as shown in Table 3, the composite material obtained using Comparative Example 6 also exhibits inferior flame retardancy. In addition, its higher water absorption rate compared to PPS raises concerns about strength reduction due to moisture absorption. The film obtained from PEI in Comparative Example 7 has a high softening temperature, resulting in poor moldability during composite material molding. Furthermore, the composite material obtained using Comparative Example 7 has a high water absorption rate (as shown in Table 3), raising concerns about strength reduction due to moisture absorption. [Explanation of Symbols]

[0120] 1 die 2 nozzles 3 Crimping Roll 4 Cast Roll 5 Film

Claims

1. A prepreg component containing a resin component containing polyphenylene sulfide, wherein the content of polyphenylene sulfide in the resin component is 80% by mass or more, the melt viscosity of the resin component is 250 Pa·s or more and 2000 Pa·s or less, the relative crystallinity is 35% or less, and the prepreg obtained by compounding the prepreg component with reinforcing fibers contains the resin and reinforcing fibers with a number average fiber length of 5 mm or more.

2. The prepreg member according to claim 1, wherein the non-Newton coefficient of the resin component is 1.0 or more and 2.5 or less.

3. The prepreg member according to claim 1 or 2, wherein the melt viscosity of the polyphenylene sulfide is 250 Pa·s or more and 2000 Pa·s or less.

4. The prepreg member according to any one of claims 1 to 3, wherein the non-Newton coefficient of the polyphenylene sulfide is 1.0 or more and 2.5 or less.

5. A prepreg component according to any one of claims 1 to 4, wherein the heat of fusion of the crystals is 30 J / g or more and 55 J / g or less.

6. A prepreg component according to any one of claims 1 to 5, which is a film.

7. A prepreg comprising a prepreg member according to any one of claims 1 to 6, compounded with reinforcing fibers.

8. A mobile body, such as an aircraft, automobile, ship, or railway vehicle, using the prepreg described in claim 7.

9. A method for manufacturing a prepreg, comprising compounding a prepreg member according to any one of claims 1 to 6 with reinforcing fibers.

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