JP7219053B2 - METHOD FOR MANUFACTURING FIBER REINFORCED RESIN MOLDED PRODUCT - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a fiber-reinforced resin molded product. Specifically, the present invention relates to a method for manufacturing a fiber-reinforced resin molded product using a fabric composed of reinforcing fibers and thermoplastic resin fibers.

In recent years, fiber-reinforced resin materials, in which resin is reinforced with reinforcing fibers such as carbon fibers and glass fibers, have been attracting attention as various materials. As one of such fiber-reinforced resin materials, the use of a woven fabric composed of reinforcing fibers and thermoplastic resin fibers has been studied (see Patent Documents 1 to 3, for example).

JP 2016-056478 A JP 2015-098669 A Japanese Patent Application Laid-Open No. 2005-330605

However, it has been found that when a fabric composed of reinforcing fibers and thermoplastic resin fibers is heat-pressed, the orientation of the reinforcing fibers in the fabric is disturbed. If the orientation of the reinforcing fibers is disturbed, the mechanical strength is deteriorated. In particular, it has been found that the orientation of the reinforcing fibers tends to be disturbed when the yarns constituting the woven fabric are covering yarns.
The present invention is intended to solve such problems, and is a molded product obtained by heat-pressing a woven fabric, which has less disturbance in the orientation of reinforcing fibers derived from hot-pressing the woven fabric and has mechanical strength. An object of the present invention is to provide a fiber-reinforced resin molded article having a high

Based on the above-mentioned problems, the present inventors have investigated and found that when a fabric composed of reinforcing fibers and thermoplastic resin fibers and the yarns constituting the fabric contains covering yarns, the fabric is formed into multiple plies ( ply), that is, when multiple layers are stacked, the orientation of the reinforcing fibers is disturbed in a region near the press surface of the hot press machine, for example, in about two plies near the surface layer of the above fabric. The present invention succeeded in suppressing disorder in the orientation of reinforcing fibers by hot-pressing a woven fabric with an open-system press and then molding it with a closed-system mold.
Specifically, the above problems have been solved by the following means <1>, preferably by <2> to <14>.
<1> A fabric composed of reinforcing fibers and thermoplastic resin fibers is hot-pressed with an open press machine, and then molded using a closed mold. A method for producing a fiber-reinforced resin molded product, wherein at least one of the wefts is a covering yarn.
<2> The method for producing a fiber-reinforced resin molded article according to <1>, wherein the molding using the closed system mold is hybrid molding with a composition containing a thermoplastic resin.
<3> The fiber reinforcement according to <2>, wherein the hybrid molding includes placing the hot-pressed fabric in a closed mold and then injecting and molding a composition containing a thermoplastic resin. A method for manufacturing a resin molded article.
<4> The thermoplastic resin contained in the composition containing the thermoplastic resin is a thermoplastic resin of the same family as the thermoplastic resin contained in the thermoplastic resin fiber, according to <2> or <3>. A method for manufacturing a fiber-reinforced resin molded article.
<5> The method for producing a fiber-reinforced resin molded product according to any one of <1> to <4>, wherein the fabric composed of the reinforcing fiber and the thermoplastic resin fiber is one ply.
<6> The method for producing a fiber-reinforced resin molded product according to any one of <1> to <4>, including laminating two or more plies of fabrics composed of reinforcing fibers and thermoplastic resin fibers.
<7> Manufacture of a fiber-reinforced resin molded product according to any one of <1> to <6>, wherein at least one of the warp and weft constituting the fabric is a covering yarn containing a reinforcing fiber as a core yarn. Method.
<8> Any one of <1> to <6>, wherein at least one of the warp and weft constituting the fabric is a covering yarn in which the core yarn is a reinforcing fiber and the sheath yarn is a thermoplastic resin fiber. The method for producing the fiber-reinforced resin molded product according to 1.
<9> The fiber-reinforced resin molded product according to <8>, wherein at least one of the warp and the weft that constitute the fabric is a thread obtained by spirally winding a thermoplastic resin fiber in the longitudinal direction of the reinforcing fiber. manufacturing method.
<10> The method for producing a fiber-reinforced resin molded article according to any one of <1> to <9>, wherein the reinforcing fiber contains at least one of carbon fiber, aramid fiber and glass fiber.
<11> The method for producing a fiber-reinforced resin molded article according to any one of <1> to <10>, wherein the thermoplastic resin fibers contain a polyamide resin.
<12> The thermoplastic resin fiber contains a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, 50 mol% or more of the diamine-derived structural unit is derived from xylylenediamine, and the dicarboxylic acid-derived structural unit is The fiber-reinforced resin molded article according to any one of <1> to <10>, wherein 50 mol% or more contains a polyamide resin derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. manufacturing method.
<13> The method for producing a fiber-reinforced resin molded product according to any one of <1> to <12>, wherein the orientation retention rate of the reinforcing fibers on the surface of the fabric after the hot pressing is less than 95%. Here, the orientation maintenance rate is defined as five areas of 10 mm x 10 mm that are orthogonal to the warp and weft from the press-molded product, and one reinforcing fiber of the warp is selected from each area, and the reinforcing fiber is pressed. It is the average value of the retention rate obtained from the following formula by measuring the length required to pass the linear distance of 10 mm of the molded product;
Retention rate = [10 mm/(length (mm) required for the reinforcing fiber to pass through a linear distance of 10 mm)] x 100 (unit: %).
<14> A fiber-reinforced resin material obtained by hot-pressing a fabric composed of reinforcing fibers and thermoplastic resin fibers with an open press machine, wherein the orientation of the reinforcing fibers on the surface of the fabric after the hot-pressing A fiber-reinforced resin material having a retention rate of less than 95%; here, the orientation retention rate refers to five 10 mm x 10 mm regions selected from a press-molded product so as to be perpendicular to the warp and weft, and the warp yarns are reinforced from each region. Select one fiber, measure the length required for the reinforcing fiber to pass through a straight line distance of 10 mm of the press-molded product, and calculate the average retention rate from the following formula;
Retention rate = [10 mm/(length (mm) required for the reinforcing fiber to pass through a linear distance of 10 mm)] x 100 (unit: %).

INDUSTRIAL APPLICABILITY According to the present invention, it has become possible to provide a fiber-reinforced resin molded article with little disorder in the orientation of reinforcing fibers caused by hot-pressing a woven fabric and with high mechanical strength.

FIG. 4 is a schematic diagram showing disordered orientation of reinforcing fibers; In FIG. 1, 1 indicates a woven fabric and 2 indicates reinforcing fibers. 4 is an X-ray micrograph showing disordered orientation of reinforcing fibers. 1 is a schematic diagram of a mold used in Examples. FIG.

The contents of the present invention will be described in detail below. In this specification, the term "~" is used to mean that the numerical values before and after it are included as the lower limit and the upper limit.

The method for producing a fiber-reinforced resin molded product of the present invention (hereinafter sometimes simply referred to as the "production method of the present invention") comprises heating a fabric composed of reinforcing fibers and thermoplastic resin fibers with an open press machine. After pressing, the fabric is further molded using a closed mold, and at least one of warp and weft constituting the fabric is a covering yarn. With such a configuration, even if the orientation of the reinforcing fibers in the fabric is disturbed by hot pressing, it is possible to suppress the orientation disturbance of the molded product after molding using a closed system mold. . Then, it becomes possible to increase the mechanical strength of the resulting fiber-reinforced resin molded product. In this specification, a woven fabric composed of reinforcing fibers and thermoplastic resin fibers, wherein at least one of the warp and weft constituting the woven fabric is a covering yarn, is referred to as a "woven fabric formed from covering yarn."That's what it means.
Specifically, when a fabric formed from covering yarns is hot-pressed with a hot-press machine, the orientation of the reinforcing fibers is disturbed as shown in FIG. Moreover, FIG. 2 is an X-ray micrograph showing a state in which the orientation of reinforcing fibers is actually disturbed. This often occurs in the surface area of the fabric near the press face of the hot press. This is presumed to be based on the fact that there is a lot of resin flow in the surface layer region of the fabric, and the orientation of the reinforcing fibers is disturbed. In the present invention, a fabric formed from the covering yarn is hot-pressed with an open-system press and then molded with a closed-system mold, thereby obtaining a molded article having excellent strength even with such a fiber-reinforced resin material. I found out that it can be done. The reason for this is speculation, but tension is applied to the reinforcing fibers during hot pressing with a press machine, but the applied tension becomes residual stress. considered to be appropriate. In the production of fiber-reinforced resin products, the products that have been hot-pressed once are often re-molded into the desired shape, so the production method of the present invention is useful from this point of view as well. The manufacturing method of the present invention is particularly useful in the case of molds with many irregularities. As an embodiment of the mold with many unevenness, the mold has recesses or protrusions with respect to the reference surface (the surface with the largest total area among the surfaces of the same height in the mold). It is a form in which the total number of parts that are formed is at least 2 or more, preferably a form in which the total number of parts that are the concave or convex parts is 5 or more, and more preferably 5 to 7. . Another embodiment of the mold with many irregularities is a form in which the height region of the mold other than the reference surface is 50% or more of the area of the reference surface of the mold. The area of height other than the plane is 66% or more, more preferably 66 to 78%, of the area of the reference plane of the mold.
The present invention will be described in detail below.

The method for producing a fiber-reinforced resin molded product of the present invention includes a step of hot-pressing a fabric formed from covering yarns with an open press machine. An open system press means a device that performs hot pressing in a state in which at least one portion of the shape of a molded product is open to the atmosphere. In such an open press machine, the thermoplastic resin leaks from the open portion during press molding, and the leakage of the thermoplastic resin disturbs the orientation of the reinforcing fibers. In the present invention, the fiber-reinforced resin material in which the orientation of the reinforcing fibers is disturbed is molded using a closed system mold, thereby suppressing the orientation disturbance of the reinforcing fibers. In the manufacturing method of the present invention, it is preferable that the woven fabric formed from the covering yarn is in contact with the hot-pressing surface of the press on at least one surface. In the present invention, it is preferable that both sides of the hot-pressing surface of the press are in contact with the woven fabric composed of the reinforcing fibers and the thermoplastic resin fibers, respectively. In addition, when only one of the warp and weft of the fabric formed from the covering yarn used in the present invention is the covering yarn, the covering yarn should be arranged in a direction perpendicular to the conveying direction of the press machine. is preferred. That is, in the present invention, it is preferable to arrange the woven fabric so that at least the direction perpendicular to the conveying direction of the press machine is the yarn formed from the covering yarn.
The press used in the present invention is not particularly limited, but for example, a general-purpose press, a roll press, a belt press, especially a double belt press can be used. For the double belt press machine, for example, the description of paragraph 0012 and FIG. 1 of JP-A-2017-066255 can be considered, and the contents thereof are incorporated herein.

Although the temperature of the hot press in the present invention is not particularly defined, it must be at least the temperature at which the thermoplastic resin fibers melt. For example, when the glass transition temperature Tg of the thermoplastic resin constituting the thermoplastic resin fiber is used as a reference, it is preferably Tg + 50 to 300 ° C., more preferably Tg + 70 to 250 ° C., Tg + 100 to 200 ° C. is more preferred. Further, when the thermoplastic resin constituting the thermoplastic resin fiber is a crystalline thermoplastic resin, the hot press temperature is based on the melting point Tm of the crystalline thermoplastic resin, and is preferably Tm + 5 to 100 ° C. Tm+10 to 90°C is more preferred, and Tm+20 to 80°C is even more preferred.
When the thermoplastic resin fiber contains two or more thermoplastic resins, the Tg or Tm of the component with the highest content is taken as the Tg or Tm of the thermoplastic resin. If the thermoplastic resin fiber contains equal amounts of two or more resins, the Tg or Tm of the resin with the highest Tg or Tm is taken.

The pressure of hot pressing in the present invention is not particularly defined, but is preferably 1 MPa or more, more preferably 1 to 6 MPa, even more preferably 2 to 5 MPa, and even more preferably 3 to 5 MPa. Such a range promotes the impregnation of the reinforcing fibers with the thermoplastic resin, making it possible to further reduce voids in the resulting fiber-reinforced resin material. The heat press time is preferably 10 seconds to 3 minutes, more preferably 30 seconds to 2 minutes and 30 seconds. By setting it in such a range, it is possible to appropriately impregnate the thermoplastic resin while suppressing discoloration (for example, yellowing) of the obtained fiber-reinforced resin material.

The woven fabric to be hot-pressed may consist of one ply of the woven fabric formed from the covering yarn, or may be a laminate of two or more plies. In the manufacturing method of the present invention, even if the material to be hot-pressed is only one ply of the fabric, an excellent molded product can be obtained by combining with molding using an open mold, which will be described later. This is because even the interior of the fabric is immediately heated, and retention of the molten resin is suppressed.
Moreover, in the manufacturing method of the present invention, two or more plies of fabrics formed from covering yarns may be laminated. By laminating two or more plies, it becomes possible to obtain a molded article having the desired mechanical properties and dimensions in a small number of steps. In the present invention, it is more preferable to laminate 3 or more plies of fabric, more preferably 5 or more plies, and even more preferably 7 or more plies. Also, the upper limit of the number of layers to be laminated is preferably 50 plies or less, more preferably 40 plies or less, and even more preferably 15 plies or less. If two or more plies of fabric are laminated, they may each be the same or different.
Furthermore, in the present invention, materials other than fabrics formed from covering yarns may also be hot-pressed at the same time. For example, a form in which a resin film, a reinforcing fiber sheet, a material other than a fabric containing reinforcing fibers and thermoplastic resin fibers (for example, a non-woven fabric), and the like are hot-pressed together with the fabric is exemplified.
In the present invention, the thickness of the stacked materials to be pressed before hot pressing is preferably 1 to 50 mm, more preferably 5 to 40 mm. The thickness of the material after hot pressing is preferably 0.1 to 5 mm, more preferably 0.5 to 4 mm.

In the present invention, the retention rate of the orientation of the reinforcing fibers on the surface of the fabric after hot pressing (and before molding using a closed mold) is preferably less than 95%, and less than 92%. is more preferred and may be less than 90%. Although the lower limit is not particularly defined, it is usually 80% or more.
Here, the orientation maintenance rate is defined as five areas of 10 mm x 10 mm that are perpendicular to the warp and weft from the press-molded product, and one reinforcing fiber of the warp is selected from each area. The length (unit: mm) required to pass the linear distance of 10 mm of the product is measured, and the average value of the retention rate obtained from the following formula.
Retention rate = [10 mm/(length (mm) required for the reinforcing fiber to pass through a linear distance of 10 mm)] x 100 (unit %)
Specifically, it is measured according to the method described in the examples below.

Next, the woven fabric used in the present invention will be described.
The woven fabric used in the present invention contains reinforcing fibers and thermoplastic resin fibers, and at least one of the warp and weft (preferably at least the weft) constituting the woven fabric is a covering yarn. Disturbance of the orientation of the reinforcing fibers was particularly likely to occur when the covering yarn was used, but by adopting the method of the present invention, it is possible to effectively suppress the disturbance of the orientation of the reinforcing fibers.
In the woven fabric of the present invention, reinforcing fibers are regularly arranged. In the present invention, the reinforcing fibers may be regularly arranged only in one direction, that is, the warp direction or the weft direction, or may be arranged regularly in two directions, that is, both the warp direction and the weft direction. good too. In the woven fabric of the present invention, the reinforcing fibers are preferably arranged linearly as warp and/or weft threads of the woven fabric. However, as will be described in detail later, it is needless to say that the regular arrangement in the present invention also includes the case where the reinforcing fibers constitute the sheath yarn of the covering yarn.
In the woven fabric used in the present invention, at least one of the warp and weft constituting the woven fabric is a covering yarn. The other of the warp yarn and the weft yarn may be a reinforcing fiber, a thermoplastic resin fiber, a covering yarn, or a reinforcing fiber other than the covering yarn and a thermoplastic resin. It may be a thread made of fibers. In the present invention, it is preferable that both the warp and the weft constituting the woven fabric are covering yarns.

A covering yarn is one in which one or more sheath yarns are wound around one or more core yarns. When the core yarn is composed of a plurality of yarns, these yarns may be aligned or twisted together. When the sheath thread is composed of a plurality of threads, these threads may be independent of each other, aligned, or twisted. In the present invention, the number of core yarns is preferably one, and the number of sheath yarns is preferably 1 to 5, from the viewpoint of the efficiency of covering yarn production. In the present invention, when 2 to 5 sheath yarns are used, it is preferable that these yarns are twisted together because the generation of fluff can be suppressed. Usually, a sheath thread is spirally wound around the core thread. Moreover, the sheath thread may be wound in one direction, or may be wound in two or more directions (in particular, two directions). In the present invention, it is preferable to wind in one direction. The reinforcing fibers and thermoplastic resin fibers that make up the covering yarn are typically continuous reinforcing fibers and continuous thermoplastic resin fibers, respectively. However, the present invention does not exclude the use of filaments formed by twisting short reinforcing fibers or short thermoplastic resin fibers.

A first embodiment of the covering yarn in the present invention is a form in which the core yarn contains reinforcing fibers. In the covering yarn, especially when the core yarn contains reinforcing fibers, the orientation of the reinforcing fibers tends to be disturbed. Therefore, the effect of applying the method of the present invention is remarkably exhibited.
In the first embodiment of the covering yarn, it is preferable to use a covering yarn in which the core yarn is a reinforcing fiber and the sheath yarn is a thermoplastic resin fiber. More specifically, it is a yarn obtained by spirally winding thermoplastic resin fibers in the longitudinal direction of the reinforcing fibers.
In the first embodiment of the covering yarn, the core yarn is a yarn composed of reinforcing fibers other than the covering yarn and thermoplastic resin fibers, and the sheath yarn is composed of reinforcing fibers and/or thermoplastic resin fibers. It is also preferred that the yarn is More preferably, the core yarn is a yarn composed of a reinforcing fiber other than the covering yarn and a thermoplastic resin fiber, and the sheath yarn is a yarn composed of a thermoplastic resin fiber.

A second embodiment of the covering yarn in the present invention is a form in which the core yarn is a thermoplastic resin fiber and the sheath yarn is a yarn containing reinforcing fibers.

Yarns composed of reinforcing fibers and thermoplastic resin fibers other than covering yarns are preferably yarns composed of continuous reinforcing fibers and continuous thermoplastic resin fibers. In addition, in the present invention, reinforcing fibers of short fibers or thermoplastic resin fibers of short fibers may be used in a filament form by means such as twisting.
Yarns composed of reinforcing fibers and thermoplastic resin fibers other than covering yarns are specifically mixed yarns composed of reinforcing fibers and thermoplastic resin fibers, and braided cords composed of reinforcing fibers and thermoplastic resin fibers. , braided cords.
Yarns composed of reinforcing fibers and resin fibers other than the covering yarn used in the present invention include, in addition to the above, the mixed yarn described in WO2014/136662, the mixed yarn described in WO2016/039242, and WO2017. /033746, the composite material described in WO2016/159340, the material described in JP-A-2016-210027, and the composite yarn described in paragraphs 0010 to 0033 of JP-A-2017-110322. exemplified, the contents of which are incorporated herein.
The covering yarn and the yarn composed of the reinforcing fiber and the resin fiber other than the covering yarn preferably account for 80% by mass or more of the entire reinforcing fiber and thermoplastic resin fiber, and more preferably 90% by mass or more. Preferably, it accounts for 95% by mass or more.

The woven fabric in the present invention is not particularly limited, and may be plain weave, eight-piece satin weave, four-piece satin weave, twill weave, or the like. A so-called bias weave or jacquard weave may also be used. Furthermore, so-called non-crimp fabrics having substantially no bends, as described in JP-A-55-30974, may also be used.

The woven fabric in the present invention preferably has a reinforcing fiber content of 20 to 80% by volume, more preferably 30 to 70% by volume, and even more preferably 35 to 65% by volume. Also, the proportion of reinforcing fibers is preferably 15 to 85% by mass, more preferably 25 to 75% by mass, even more preferably 30 to 60% by mass. Such a structure tends to improve mechanical properties and moldability.
Also, the proportion of resin fibers is preferably 15 to 85% by mass, more preferably 25 to 75% by mass, and even more preferably 40 to 70% by mass. Such a structure tends to provide excellent drape performance and facilitate molding.
Furthermore, the woven fabric in the present invention may or may not contain components other than reinforcing fibers and thermoplastic resin fibers. In the woven fabric of the present invention, the total content of reinforcing fibers and thermoplastic resin fibers is preferably 80% by volume or more, more preferably 90% by volume or more, and even more preferably 95% by volume or more. Also, the total content of the reinforcing fibers and the thermoplastic resin fibers is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. With such a configuration, the effects of the present invention are exhibited more effectively.
The fabric weight in the present invention is preferably 50 to 10,000 g/m ² , more preferably 75 to 9,000 g/m ² , even more preferably 100 to 8,000 g/m ² . With such a configuration, the effects of the present invention are exhibited more effectively.

The woven fabric in the present invention may have a structure in which at least one end portion of the woven fabric has a higher ratio of reinforcing fibers than the central portion. With such a configuration, the reinforcing fibers at the ends can trap the resin that has flowed out from the inside. Here, at least one direction of the fabric refers to one of the warp direction and the weft direction of the fabric. The term "end portion" refers to a region within 10% of the length of the fabric in the warp direction or the width of the fabric in the weft direction from the end of the fabric, and may be a region within 5%. Further, the end portion of the fabric specifically refers to a region of 1 to 20 cm from the end of the fabric. In the production method of the present invention, when continuously producing a fiber-reinforced resin material, it is preferable that the ratio of reinforcing fibers is higher at the ends in the weft direction than at the center.
In the present invention, when the volume of reinforcing fibers per unit area of the fabric contained in the center of the fabric (area other than the area within 10% from the end of the fabric) is 100, the end of the fabric (from the end of the fabric The volume of reinforcing fibers per unit area of the woven fabric contained in the area within 10% is preferably 110 to 200, more preferably 150 to 200.

Another embodiment of the woven fabric of the present invention is a mode in which the third fibers are woven in a direction perpendicular to the woven surface defined by the warp and weft directions. By weaving the third fibers, the reinforcing fibers are fixed, and the orientation of the reinforcing fibers can be made less likely to be disturbed.
The third fiber may or may not melt during hot pressing, but preferably does not melt. The third fibers may be reinforcing fibers, resin fibers (thermoplastic resin fibers, thermosetting resin fibers), or other fibers. Preferred are thermoplastic resin fibers.
When a thermoplastic resin fiber is used as the third fiber, the glass transition temperature Tg of the thermoplastic resin constituting the thermoplastic resin fiber is preferably Tg + 10 to 300 ° C., and Tg + 30 to 280 ° C. more preferably Tg+50 to 260°C. Further, when the thermoplastic resin constituting the thermoplastic resin fiber is a crystalline thermoplastic resin, the melting point Tm of the crystalline thermoplastic resin is used as a reference, and it is preferably Tm + 10 to 200 ° C., and Tm + 20 to 190 ° C. more preferably Tm+30 to 180°C.
The third fibers may be woven into one ply of fabric, or may be woven into two or more plies of fabric. By weaving two or more plies of woven fabrics in an overlapping state, it is possible to effectively suppress a reduction in the strength of the molded product due to peeling between the woven fabrics.
The third fiber preferably has a crimp angle of 10 to 80 degrees, more preferably 20 to 70 degrees, with respect to the fabric surface. By setting it in such a range, the mechanical strength of the obtained molded product can be effectively improved, and the orientation of the reinforcing fibers can be more effectively suppressed.

Next, the reinforcing fibers used in the present invention will be explained. The reinforcing fibers used in the present invention constitute a woven fabric. The reinforcing fibers used in the present invention may be short fibers or long fibers (continuous reinforcing fibers), but continuous reinforcing fibers are preferred. Continuous reinforcing fibers refer to reinforcing fibers having a number average fiber length of 30 mm or more, preferably continuous reinforcing fibers having a number average fiber length of 50 cm or more. The number average fiber length of the continuous reinforcing fibers used in the present invention is not particularly limited, but from the viewpoint of improving moldability, it is preferably in the range of 1 to 20,000 m, more preferably 100 to 10,000 m. 000 m, more preferably 1,000 to 7,000 m.

The reinforcing fibers used in the present invention include inorganic fibers such as glass fibers, carbon fibers, alumina fibers, boron fibers, ceramic fibers, metal fibers (steel fibers, etc.), and vegetable fibers (Kenaf, bamboo fibers, etc.). ), aramid fibers, polyoxymethylene fibers, aromatic polyamide fibers, polyparaphenylenebenzobisoxazole fibers, and organic fibers such as ultra-high molecular weight polyethylene fibers. Among them, at least one of carbon fiber, aramid fiber and glass fiber is preferable, at least one of carbon fiber and glass fiber is more preferable, and at least one of glass fiber is particularly preferable. Moreover, from the viewpoint of the effect of restoring the orientation of the reinforcing fibers, at least one type of carbon fiber is preferable.

The reinforcing fibers used in the present invention are preferably treated with a treating agent. Examples of such treatment agents include sizing agents and surface treatment agents, and those described in paragraphs 0093 and 0094 of Japanese Patent No. 4894982 are preferably employed, the contents of which are incorporated herein.
The amount of the treatment agent is preferably 0.001 to 1.5% by mass of the reinforcing fiber, more preferably 0.1 to 1.2% by mass, and 0.5 to 1.1% by mass. is more preferable.

The reinforcing fibers used in the present invention may be monofilaments, but are preferably multifilaments.

Next, the thermoplastic resin fibers used in the present invention will be explained.
The thermoplastic resin fibers used in the present invention may be short fibers or long fibers (continuous fibers), preferably continuous fibers. A continuous fiber refers to a fiber having a number average fiber length of 30 mm or more, preferably a fiber having a number average fiber length of 50 cm or more. The number average fiber length of the continuous fibers used in the present invention is not particularly limited, but from the viewpoint of improving moldability, it is preferably in the range of 1 to 20,000 m, more preferably 100 to 10,000 m. , more preferably 1,000 to 7,000 m.
The thermoplastic resin fibers used in the present invention may be monofilaments, but are preferably multifilaments.
The thermoplastic resin fibers used in the present invention are composed of a thermoplastic resin fiber-forming composition containing a thermoplastic resin. The thermoplastic resin fiber-forming composition contains a thermoplastic resin as a main component (usually 90% by mass or more, preferably 95% by mass or more of the composition is a thermoplastic resin). Depending on the requirements, known additives and the like are appropriately blended. As an example of an embodiment of the present invention, the resin contained in the thermoplastic resin fiber-forming composition includes a mode in which a specific type of resin accounts for 80% by mass or more of the total, and further, the thermoplastic resin fiber As for the resin contained in the forming composition, there is also an embodiment in which one specific resin accounts for 90% by mass or more of the whole. Moreover, the resin contained in the thermoplastic resin fiber-forming composition may be a blend of two or more.
As the thermoplastic resin, thermoplastic resins used for fiber-reinforced resin materials can be widely used. , polyimide resin, polyether ether ketone resin, polyether ketone ketone resin, polyether ketone resin and the like can be used, and polyamide resin and polyacetal resin are preferred, and polyamide resin is more preferred.
When the thermoplastic resin fiber in the present invention contains a polyamide resin, the proportion of the polyamide resin in the thermoplastic resin is preferably 50% by mass or more, more preferably 80% by mass or more, and 90% by mass or more. and more preferably 95% by mass or more.

In the present invention, the thermoplastic resin constituting the thermoplastic resin fiber preferably has a melt viscosity of 10 Pa·sec or more, preferably 25 Pa·sec or more, at a temperature of +20° C., a shear rate of 1216 sec ⁻¹ , and a retention time of 6 minutes. is more preferable, and may be 100 Pa·sec or more, or 150 Pa·sec or more. The upper limit of the melt viscosity is preferably 1000 Pa·sec or less, more preferably 750 Pa·sec or less, even more preferably 500 Pa·sec or less, and even more preferably 400 Pa·sec or less. , 300 Pa·sec or less. By setting the melt viscosity to such a value, the impregnation speed is increased, and a fiber-reinforced material having excellent productivity can be obtained.

A known polyamide resin is used as the polyamide resin.
For example, polyamide 4, polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 66, polyamide 610, polyamide 612 and other aliphatic polyamide resins, and polyhexamethylene terephthalamide (polyamide 6T), polyhexamethylene isophthalamide Semi-aromatic polyamide resins such as amide (polyamide 6I), polyamide 9T, and XD-based polyamide resin, which will be detailed later. A semi-aromatic polyamide resin means that 40 to 60 mol % of the total structural units of the polyamide resin are structural units containing an aromatic ring.

Further, the polyamide resin contains structural units derived from diamine and structural units derived from dicarboxylic acid, 50 mol% or more of the structural units derived from diamine are derived from xylylenediamine, and 50 mol% or more of the structural units derived from dicarboxylic acid. is derived from an α,ω-straight-chain aliphatic dicarboxylic acid having 4 to 20 carbon atoms (hereinafter sometimes referred to as “XD-based polyamide resin”).
The XD-based polyamide resin accounts for 50 mol% or more, preferably 70 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more, and even more preferably 99 mol% or more of the diamine-derived structural units. At least mol % is derived from xylylenediamine (preferably meta-xylylenediamine and/or para-xylylenediamine). In addition, the XD-based polyamide resin contains 50 mol% or more, preferably 70 mol% or more, more preferably 90 mol% or more, and still more preferably 95 mol% or more of the dicarboxylic acid-derived structural units. Preferably, 99 mol % or more is derived from α,ω-straight-chain aliphatic dicarboxylic acids having 4 to 20 carbon atoms.

Examples of diamines other than xylylenediamine that can be used as raw material diamine components for XD-based polyamide resins include tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, and nonamethylene. Aliphatic diamines such as diamines, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 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) ) alicyclic diamines such as decalin and bis(aminomethyl)tricyclodecane, diamines having an aromatic ring such as bis(4-aminophenyl)ether, paraphenylenediamine, and bis(aminomethyl)naphthalene can be used alone or in combination of two or more.
When a diamine other than xylylenediamine is used as the diamine component, it is 50 mol% or less, preferably 30 mol% or less, more preferably 1 to 25 mol%, particularly preferably 5 to 5 mol% of the diamine structural unit. It is used at a rate of 20 mol %.

Examples of α,ω-straight-chain aliphatic dicarboxylic acids having 4 to 20 carbon atoms which are preferable for use as a starting dicarboxylic acid component for polyamide resins include succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, and adipic acid. , sebacic acid, undecanedioic acid, dodecanedioic acid, etc. can be exemplified, and one or a mixture of two or more thereof can be used. Adipic acid or sebacic acid are preferred due to their range.

Examples of dicarboxylic acid components other than the α,ω-straight-chain aliphatic dicarboxylic acids having 4 to 20 carbon atoms include phthalic acid compounds such as isophthalic acid, terephthalic acid and orthophthalic acid, 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 isomers such as naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid can be exemplified, and can be used singly or in combination of two or more.

When using a dicarboxylic acid other than an α,ω-straight-chain aliphatic dicarboxylic acid having 4 to 20 carbon atoms as the dicarboxylic acid component, terephthalic acid and isophthalic acid can be used from the viewpoint of moldability and barrier properties. preferable. When terephthalic acid or isophthalic acid is blended, the blending ratio is preferably 30 mol % or less, more preferably 1 to 30 mol %, particularly preferably 5 to 20 mol %, of the dicarboxylic acid structural unit.

Furthermore, in addition to the diamine component and the dicarboxylic acid component, as components constituting the polyamide resin, lactams such as ε-caprolactam and laurolactam, aminocaproic acid, aminoundecanoic acid and other aliphatic Aminocarboxylic acids can also be used as copolymerization components.

In the present invention, preferably 90 mol% or more, more preferably 95 mol% or more, and still more preferably 99 mol% or more of the total structural units constituting the XD-based polyamide resin are diamine-derived structural units and dicarboxylic acid-derived Consists of the constituent units of

XD-based polyamide resins that can be used in the present invention include poly-meta-xylylene adipamide resin, poly-me-xylylene sebacamide resin, poly-para-xylylene sebacamide resin, and meta-xylylene diamine and para-xylylene diamine. Polymeta-xylylene/para-xylylene mixed adipamide resins obtained by polycondensation of mixed xylylene diamines with adipic acid are preferred, and more preferred are poly-meta-xylylene sebacamide resins, poly-para-xylylene sebacamide resins and meta-xylylene sebacamide resins. Mixture of diamine and paraxylylenediamine A polymeta-xylylene/para-xylylene mixed sebacamide resin obtained by polycondensing xylylenediamine with sebacic acid. These polyamide resins tend to have particularly good moldability.

The XD-based polyamide resin used in the present invention preferably has a melt viscosity of 10 Pa sec or more, more preferably 25 Pa sec or more at a temperature of +20 ° C., a shear rate of 1216 sec ⁻¹ , and a holding time of 6 minutes. , 100 Pa·sec or more, or 150 Pa·sec or more. The upper limit of the melt viscosity is preferably 1000 Pa·sec or less, more preferably 750 Pa·sec or less, even more preferably 500 Pa·sec or less, and even more preferably 400 Pa·sec or less. , 300 Pa·sec or less. With such a melt viscosity, the impregnation property can be further improved, and discoloration (for example, yellowing) can be further reduced.
The melt viscosity of the XD-based polyamide resin can be adjusted by appropriately selecting, for example, the charging ratio of the raw dicarboxylic acid component and the diamine component, the polymerization catalyst, the molecular weight modifier, the polymerization temperature, and the polymerization time.

In the present invention, the melting point of the polyamide resin is preferably 150-310°C, more preferably 180-300°C.
Also, the glass transition point of the polyamide resin is preferably 50 to 110°C, more preferably 55 to 100°C, and particularly preferably 60 to 100°C. Within this range, the heat resistance tends to be good.

The melting point is the peak top temperature of the endothermic peak during temperature rise observed by DSC (differential scanning calorimetry). Further, the glass transition point is the glass transition point measured by heating and melting the sample once to eliminate the influence of the heat history on the crystallinity, and then raising the temperature again. For the measurement, for example, "DSC-60" manufactured by Shimadzu Corporation (SHIMADZU CORPORATION) is used, the sample amount is about 5 mg, nitrogen is flowed at 30 mL / min as the atmosphere gas, and the temperature increase rate is 10 ° C. / min. The melting point can be determined from the peak top temperature of the endothermic peak observed when the material is heated from room temperature (25° C.) to a temperature higher than the expected melting point and melted under certain conditions. Next, the melted polyamide resin is rapidly cooled with dry ice, heated again to a temperature above the melting point at a rate of 10° C./min, and the glass transition point can be determined.

As described above, the thermoplastic resin fibers are more preferably made of the thermoplastic resin fiber-forming composition. The thermoplastic resin fiber-forming composition contains a thermoplastic resin as a main component, and may contain additives and the like.

The thermoplastic resin fiber-forming composition used in the present invention may contain an elastomer component.
As the elastomer component, for example, known elastomers such as polyolefin elastomers, diene elastomers, polystyrene elastomers, polyamide elastomers, polyester elastomers, polyurethane elastomers, fluorine elastomers and silicone elastomers can be used, preferably polyolefin elastomers. Elastomers and polystyrene elastomers. These elastomers are modified with α,β-unsaturated carboxylic acids and their acid anhydrides, acrylamide and their derivatives in the presence or absence of radical initiators in order to impart compatibility with polyamide resins. Also preferred are modified elastomers.

The content of the elastomer component is usually 30% by mass or less, preferably 20% by mass or less, and particularly 10% by mass or less in the thermoplastic resin fiber-forming composition.

Furthermore, the thermoplastic resin fiber-forming composition used in the present invention contains antioxidants, stabilizers such as heat stabilizers, hydrolysis resistance improvers, and additives such as agents, matting agents, UV absorbers, nucleating agents, plasticizers, dispersants, flame retardants, antistatic agents, anti-coloring agents, anti-gelling agents, coloring agents, release agents, lubricants, etc. be able to. Details thereof can be referred to paragraphs 0130 to 0155 of Japanese Patent No. 4894982, and the contents thereof are incorporated herein.

In the present invention, the woven fabric (fiber reinforced resin material) hot-pressed with a hot press is further molded using a closed mold. The molding using the closed system mold may be performed immediately after the hot press, or may be performed after some time.
In the present invention, it is preferable to continuously perform molding using a closed mold after hot pressing. Continuously refers to molding using a closed system mold before the thermoplastic resin fibers in the woven fabric plasticized by, for example, heat press are completely cured. A mode in which hot pressing and molding using a closed system mold are successively performed in the same factory also corresponds to continuous molding.
Moreover, when carrying out after a while, the fiber-reinforced resin material may be once wound on a roll.
A closed system mold means a mold that is closed in all directions to the extent that molten resin does not flow out of the mold when pressurized. The closed system mold is preferably a mold having irregularities, and more preferably a mold having many irregularities as described above. By using a mold having such unevenness, the reinforcing fibers are stretched in the closed mold, and the reinforcing fibers can be oriented more effectively.

The molding using the closed mold is not particularly limited as long as the hot-pressed fabric is arranged in the closed mold.
In the present invention, only the hot-pressed fabric may be placed in a closed mold and molded, but preferably, after heating with an IR heater or the like, draw press molding is performed in a closed mold. Preferably, the hot-pressed fabric and other material are placed in a mold for hybrid molding, which is particularly preferred. As the press die, a die with an electromagnetic induction heating system capable of high-speed temperature control or a Thermo Assisted Molding system is preferable. Molds suitable for mass production, such as single-shot, transfer, and progressive molds, are preferable. Also, there is a mold that is divided into three, four or more divisions capable of molding complicated shapes. Examples of other materials include, but are not limited to, compositions containing thermoplastic resins. In the present invention, a method of placing the hot-pressed woven fabric in a closed mold and then injecting and molding a composition containing a thermoplastic resin is preferred.

The mold temperature when injecting the composition containing the thermoplastic resin is preferably higher than the melting point or higher than the glass transition temperature of the thermoplastic resin fibers forming the fabric. More preferably, the melting point of the thermoplastic resin constituting the thermoplastic resin fiber is +10°C or higher, or the glass transition temperature is +10°C or higher, more preferably the melting point is +20°C or higher, or the glass transition temperature is +20°C or higher, and the melting point is +30°C or higher. °C or higher, or the glass transition temperature +30 °C or higher. Although the upper limit is not particularly defined, it can be, for example, the melting point +70°C or less or the glass transition temperature +70°C or less. If the thermoplastic resin has both a melting point and a glass transition temperature, the higher temperature preferably satisfies the above range.
In addition, the timing of injecting the composition containing the thermoplastic resin and filling the mold is determined by setting the heat-pressed fabric in the mold and closing the mold, and the mold temperature is the melting point of the thermoplastic resin. It is preferably within 30 seconds after the temperature is raised to the glass transition point or higher.
In the fiber-reinforced resin molded article obtained by the hybrid molding, it is preferable that the joint portion of the textile and the composition containing the thermoplastic resin formed by injection molding has an uneven structure that is mixed with each other.
Setting the mold temperature above the melting point of the composition containing the thermoplastic resin to be injected and setting the holding pressure of the resin at the time of injection molding to a high value, for example, 1 MPa or more is effective in increasing the interfacial strength. In order to increase the interfacial strength, the holding pressure is preferably 5 MPa or more, more preferably 10 MPa or more. Although the upper limit is not particularly defined, it can be, for example, 20 MPa or less.
In addition, the pressure holding time is, for example, 5 seconds or longer, preferably 10 seconds or longer, and more preferably until the mold temperature reaches the melting point of the composition containing the thermoplastic resin or less. It is preferable from the viewpoint of enhancement. Although the upper limit of the holding pressure time is not particularly defined, it can be, for example, 5 minutes or less.

The composition containing the thermoplastic resin may consist of only one or two or more thermoplastic resins, or may contain components other than the thermoplastic resin.
The thermoplastic resin contained in the composition containing the thermoplastic resin is preferably a thermoplastic resin of the same type as the thermoplastic resin contained in the thermoplastic resin fiber. Thermoplastic resins of the same type include, for example, polyamide resins, polyester resins, polyolefin resins, polypropylene resins, polyethylene resins, acrylic resins, polyacetal resins, polycarbonate resins, styrene resins, and polyimide resins. , between polyamideimide resins, between polyamide resins and polyamideimide resins, between polyimide resins and polyamideimide resins, between polyether resins, between polyetherketone resins, between polyetheretherketone resins, between polyetherketoneketone resins, Combination of polyether ether ketone resin and polyether ketone ketone resin, combination of polyphenylene sulfide resin, combination of polyether sulfone polyphenylene sulfide resin and polyether sulfone resin, combination of polyetherimide resin, combination of polyetherimide resin and polyimide resin , a combination of a polyetherimide resin and a polyetherketone resin, a combination of a polyamide resin and a polyurethane resin, and the like. By using such a resin of the same family, it is possible to improve the adhesiveness to the fabric.
In the present invention, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more of the thermoplastic resin contained in the composition containing the thermoplastic resin is the thermoplastic resin contained in the thermoplastic resin fiber. It is preferably a resin of the same type.

The composition containing a thermoplastic resin may contain 100% by mass of the thermoplastic resin, but may contain other components. When other components are included, the total amount of the thermoplastic resin in the composition containing the thermoplastic resin is preferably 30% by mass or more, more preferably 35% by mass or more, and 35 to 70%. % by mass is more preferred.
Examples of the other component in the composition containing the thermoplastic resin include one or more selected from components other than the resin that may be blended in the composition for forming the thermoplastic resin fiber. A composition containing a thermoplastic resin may also contain a filler. Fillers include glass fiber, carbon fiber, talc, mica, glass flakes, wollastonite, potassium titanate whiskers, magnesium sulfate, sepiolite, xonolite, aluminum borate whiskers, glass beads, balloons, calcium carbonate, silica, and kaolin. , clay, titanium oxide, barium sulfate, zinc oxide, and magnesium hydroxide. When such a filler is contained in a composition containing a thermoplastic resin, it is preferably contained in a proportion of 10 to 70% by mass.

The form of the composition containing the thermoplastic resin is not particularly specified, but in the case of injection molding, a molten pellet is generally used. In addition, the composition containing a thermoplastic resin is a part molded from a composition containing a thermoplastic resin, a film molded from a composition containing a thermoplastic resin, a powder of a composition containing a thermoplastic resin, and the like. Needless to say, it is possible.

The fiber-reinforced resin molded product thus obtained may be a final product or a part. The field of application of the fiber-reinforced resin molded product of the present invention is not particularly defined, and it is used as transportation equipment parts such as automobiles, general machine parts, precision machine parts, electronic and electric equipment parts, OA equipment parts, building materials / housing equipment parts, It is widely used in medical equipment, leisure sports equipment, playground equipment, medical products, daily necessities such as food packaging films, and defense and aerospace products. In addition, it can also be used for applications described in paragraph 0038 of JP-A-2017-110322, the contents of which are incorporated herein.

EXAMPLES The present invention will be described more specifically with reference to examples below. The materials, usage amounts, ratios, processing details, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the gist of the present invention. Accordingly, the scope of the present invention is not limited to the specific examples shown below.

1. Raw material <thermoplastic resin>
MXD6: meta-xylylene adipamide resin (manufactured by Mitsubishi Gas Chemical Company, grade S6011, pellets), melt viscosity 280 Pa·sec, melting point 237°C, glass transition temperature 85°C
MP10: meta-para-xylylene sebacamide resin obtained in the following synthesis example, melt viscosity 210 Pa·sec, melting point 213°C, glass transition temperature 63°C
PA6: 1024B manufactured by Ube Industries, pellets, melt viscosity 310 Pa·sec, melting point 224°C, glass transition temperature 50°C
PP: polypropylene resin, manufactured by Mitsubishi Chemical Corporation, grade FY6, pellets, melting point 165°C, glass transition temperature 0°C

<Synthesis example of MP10>
10 kg (49.4 mol) of sebacic acid (TA grade manufactured by Ito Oil Co., Ltd.) and acetic acid were placed in a reaction vessel equipped with a stirrer, partial condenser, total condenser, thermometer, dropping funnel, nitrogen inlet tube, and strand die. After charging 11.66 g of sodium/sodium hypophosphite monohydrate (molar ratio = 1/1.5) and sufficiently replacing with nitrogen, the inside of the system was further stirred under a small amount of nitrogen stream to 170 g. It melted by heating up to °C.
6.647 kg of mixed xylylenediamine (34.16 mol of meta-xylylenediamine, 34.16 mol of meta-xylylenediamine, 14.64 mol) of diamine was added dropwise to the melted sebacic acid with stirring, and the internal temperature was continuously raised to 240° C. over 2.5 hours while the resulting condensed water was discharged out of the system.
After the dropwise addition was completed, the internal temperature was increased, and when the temperature reached 250°C, the pressure inside the reaction vessel was reduced, and the internal temperature was further increased to continue the melt polycondensation reaction at 255°C for 20 minutes. Thereafter, the inside of the system was pressurized with nitrogen, and the resulting polymer was taken out from the strand die and pelletized to obtain a polyamide resin (MP10).
<Reinforcing fiber>
Glass fiber (continuous fiber): manufactured by Nitto Boseki Co., Ltd., product number: ECDE150 1/0 1.0Z
Short glass fiber: manufactured by Nitto Boseki Co., Ltd., product number: CSG3PA810
Carbon fiber (continuous fiber): TR-50S manufactured by Mitsubishi Chemical Corporation

<Production of resin pellets containing MXD6 and glass fiber>
A raw material resin was introduced from the base of a twin-screw extruder (TEM26SS, manufactured by Toshiba Machine Co., Ltd.), melted, and then short glass fibers were side-fed to prepare resin pellets containing short glass fibers. The set temperature of the extruder was 280°C. The glass fiber content was 30% by mass.

<MXD6 film>
Polyamide resin (MXD6) dried with a vacuum dryer is melt extruded with a single screw extruder having a screw with a diameter of 30 mm, extruded through a T die with a width of 500 mm, and a stainless steel with uneven texture on the surface A pair of rolls manufactured by the manufacturer was applied at a roll temperature of 70° C. and a roll pressure of 0.4 MPa to form a film having grains on the film surface. The average thickness of the resulting MXD6 film was 50 μm.

<Method for measuring melt viscosity>
The melt viscosity was measured using a capillary rheometer at a temperature of +20°C of the melting point, a shear rate of 1216 sec ^-1 and a retention time of 6 minutes. In this example, the capillary rheometer used was "Capillograph 1D" manufactured by Toyo Seiki Seisakusho Co., Ltd. A capillary with a diameter of 1.0 mm was used.

<Measuring method of melting point and glass transition temperature>
Differential scanning calorimetry was performed according to JIS K7121 and K7122. Using a differential scanning calorimeter, the above pellet-shaped thermoplastic resin is crushed, charged into the measurement pan of the differential scanning calorimeter, heated to 300° C. at a temperature increase rate of 10° C./min in a nitrogen atmosphere, and rapidly cooled. Measurements were taken after pretreatment. The measurement conditions were a temperature increase rate of 10°C/min and a temperature of 300°C for 5 minutes, followed by a temperature decrease rate of -5°C/min down to 100°C to determine the glass transition temperature (Tg) and melting point (Tm). rice field. As a differential scanning calorimeter, "DSC-60" manufactured by Shimadzu Corporation (SHIMADZU CORPORATION) was used.

2. Fabric production <Method for producing thermoplastic resin fiber>
Thermoplastic resins (those in Table 1 or Table 2, MXD6, MP10, PA6, PP) dried at 150° C. for 7 hours using a vacuum dryer are melt-extruded with a single-screw extruder having a screw with a diameter of 30 mm. and extruded into strands from a 60-hole die. The extruded thermoplastic resin was cooled by an air blow and solidified. A treating agent was applied to the fibers through a roll whose lower part was immersed in the treating agent, and bundled and stretched while passing through a plurality of guides and wound on a roll to obtain a thermoplastic resin fiber bundle.

<Method for producing yarn 1 containing resin fiber and glass fiber>
The thermoplastic resin fiber is spirally wound in the longitudinal direction of the reinforcing fiber so that the glass fiber is 60% by mass (40% by volume) and the thermoplastic resin fiber is 40% by mass (60% by volume). Thus, a yarn (covering yarn) composed of glass fiber and thermoplastic resin fiber was obtained. However, the thread using the polypropylene resin was adjusted so as to contain 60% by mass (35% by volume) of glass fiber and 40% by mass (65% by volume) of polypropylene resin.

<Method for producing yarn 2 containing thermoplastic resin fiber and carbon fiber>
The thermoplastic resin fiber is helically wound in the longitudinal direction of the reinforcing fiber so that the carbon fiber is 60% by mass and the thermoplastic resin fiber is 40% by mass, and the glass fiber and the thermoplastic resin fiber are mixed. A structured yarn (covering yarn) was obtained.

<Method for producing yarn 3 containing resin fiber and glass fiber>
The thermoplastic resin fiber is spirally wound in the longitudinal direction of the reinforcing fiber so that the glass fiber is 40% by mass and the thermoplastic resin fiber is 60% by mass, and the glass fiber and the thermoplastic resin fiber are mixed. A structured yarn (covering yarn) was obtained.

<Manufacturing method of textile 1>
A glass fiber was used as warp, and the yarn 3 composed of the glass fiber and the thermoplastic resin fiber obtained above was used as weft, and woven using a rapier loom. The number of yarns applied was 44 warps/25 mm and 34 wefts/25 mm. The resulting woven fabric had a basis weight of 200 g/m ² , a thickness of 200 μm, a proportion of thermoplastic resin fibers of 40% by mass (60% by volume), and a proportion of reinforcing fibers of 60% by mass (40% by volume).

<Method for producing fabric 2>
The yarn 2 obtained above was woven using a rapier loom. The number of yarns applied was 12.5 warps/25 mm and 12.5 wefts/25 mm. The resulting woven fabric had a basis weight of 200 g/m ² , a thickness of 300 μm, a proportion of thermoplastic resin fibers of 60% by mass, and a proportion of reinforcing fibers of 40% by mass.

<Manufacturing method of fabric 3>
The yarn 3 obtained above was woven using a rapier loom. The number of yarns applied was 30 warps/25 mm and 20 wefts/25 mm. The resulting woven fabric had a basis weight of 100 g/m ² , a thickness of 150 μm, a proportion of thermoplastic resin fibers of 60% by mass, and a proportion of reinforcing fibers of 40% by mass.

<Manufacturing method of fabric 4>
A bundle of glass fibers and a bundle of thermoplastic resin fibers were woven using a rapier loom. The number of warp yarns was 30/25 mm, and the glass fiber and the thermoplastic resin fiber were alternately arranged. Similarly, the weft yarn was 20/25 mm, and the glass fiber and the thermoplastic resin fiber were arranged alternately. The resulting woven fabric had a basis weight of 100 g/m ² , a thickness of 150 μm, a proportion of thermoplastic resin fibers of 60% by mass, and a proportion of reinforcing fibers of 40% by mass.

Example 1
<Production of heat-pressed fabric>
The fabric shown in Table 1 (Fabric 3) was laminated by the number (plies) shown in Table 1, and put between the steel belts of a double belt press manufactured by HELD at a conveying speed of 1.0 min / m. The fabric was continuously hot-pressed at a pressure of 4 MPa for 2 minutes and then cooled at a melting point of −80° C. for 1 minute while being continuously pressed at 4 MPa to obtain a hot-pressed fabric. The thickness of the hot-pressed fabric obtained was 130 μm. The woven fabric was placed in the belt press so that the warp threads were aligned with the transport direction of the belt press.

<Molding using a closed system mold>
A hybrid molding machine (VPM1013H) manufactured by Sato Iron Works was used as the molding machine. A mold having a shape shown in FIG. 3 was used. In FIG. 3, grooves indicated by 3 are portions into which the resin composition (material to be combined with the fabric) is injected.
Heat the hot-pressed fabric with an infrared heater, place it in the mold after the material temperature reaches the melting point of the thermoplastic resin + 70 ° C. The resin composition (material to be combined with the fabric) is injected and filled at an injection pressure of 50 MPa and an injection speed of 20 mm / sec, and cooled and solidified by applying a holding pressure of 60 MPa, and the hot-pressed fabric and resin. Bonding with the composition (the material to be combined with the fabric) was carried out. The cylinder setting temperature of the injection molding machine was the melting point of the thermoplastic resin +50°C.
After molding, the mold was opened to obtain a fiber-reinforced resin molded product.

<Orientation maintenance rate of reinforcing fibers (after hot press)>
The surface roughness of the heat-pressed fabric was evaluated according to the following criteria.
For the retention rate, 5 regions of 10 mm×10 mm were selected so as to be perpendicular to the warp and weft from the hot-pressed fabric, and one warp reinforcing fiber was selected from each region. The length required for the reinforcing fiber to pass through a straight line distance of 10 mm of the heat-pressed fabric was measured, and the retention rate was obtained from the following equation.
Retention rate = [10 mm/(length (mm) required for the reinforcing fiber to pass through a linear distance of 10 mm)] x 100 (unit %)

<Disturbance of reinforced fiber orientation (fiber reinforced resin molded product)>
Disturbances in the orientation of the reinforcing fibers of the fiber-reinforced resin molded product were measured.
Five regions of 10 mm×10 mm were selected from the fiber-reinforced resin molded product so as to be orthogonal to the warp and weft, and one warp reinforcing fiber was selected from each region. The length required for the reinforcing fiber to pass through the fiber-reinforced resin molded product at a linear distance of 10 mm was measured. The value obtained by dividing the length by 10 mm was evaluated as the disturbance of orientation in the following stages. An X-ray image of the surface layer was measured using a CT-scan (TDM 1000H-II manufactured by Yamato Co., Ltd.). For image analysis, an arbitrary reinforcing fiber was selected using image analysis software Azo-kun (manufactured by Asahi Kasei Engineering Co., Ltd.) and its length was measured.
A: 1.04 or less: little or no turbulence B: more than 1.04 and 1.07 or less: slightly turbulent C: more than 1.07 and less than 1.10: slightly turbulent D: 1. 10 or higher: very disorganized

<Mechanical Strength of Fiber Reinforced Resin Molded Product>
A 20 x 80 (mm) test piece is cut out perpendicular to the warp and weft from a region different from the rib, which is not directly affected by the injection molded resin, and the bending strength is obtained according to JIS K7171. rice field. A strograph manufactured by Toyo Seiki Co., Ltd. was used as an apparatus, and the measurement temperature was 23° C. and the measurement humidity was 50% RH (relative humidity). For Examples and Comparative Examples in which injection molding was not performed, such as Example 9, which will be described later, the same size was cut out from an arbitrary position and measured in the same manner.

<Examples 2 to 8>
In Example 1, as described in Table 1 or Table 2, the type of woven fabric, the number of woven fabric layers, and the material combined with the woven fabric were changed, and the rest was carried out in the same manner. However, in Example 4, a mold having a thickness twice that of Example 1 was used. In Example 6, a mold having a molded product thickness of 1/2 that of Example 1 was used. In addition, in Example 8, a mold having a thickness of ⅕ times that of Example 1 was used.

<Example 9>
In Example 1, the molding process using the closed system mold was changed as follows, and the others were carried out in the same manner.
A resin film was placed in a mold, and a rapidly heated fiber-reinforced resin molded product was placed in the mold, clamped, and pressed at 5 MPa for 5 minutes without using the injection molding unit of the hybrid molding machine.

<Example 10>
In Example 1, the molding process using the closed system mold was changed as follows, and the others were carried out in the same manner.
The fiber-reinforced resin molded product of the woven fabric 2 was heated, placed in a mold, clamped, and pressed at 5 MPa for 5 minutes without using the injection molding unit of the hybrid molding machine.

<Comparative Example 1>
In Example 1, the molding process using the closed system mold was omitted, and the rest was carried out in the same manner.

<Reference example 1>
The fabric 1 was placed in a mold at room temperature, the mold was clamped, and the temperature was raised to 260° C. over 15 minutes while applying 3 MPa. It was held at 260° C. for 15 minutes, and after the material was impregnated, it was cooled to room temperature over 30 minutes while applying 3 MPa.

<Reference example 2>
The procedure was the same as in Example 1 except that the woven fabric 3 was changed to the woven fabric 4.

As is clear from the above results, when the fabric formed from the covering yarn is hot-pressed with an open-system press and then molded using a closed-system mold, the orientation of the reinforcing fibers after hot-pressing is disturbed. was observed, but the disorder of the reinforcing fibers of the molded product was suppressed (Examples 1 to 10). Furthermore, the mechanical strength tended to be excellent (Examples 1 to 7, 9, 10). As for Example 8, the thickness was small, it was easy to bend, and it did not break.
On the other hand, when only hot pressing was performed in an open system, the molded product was disturbed (Comparative Example 1).
In addition, in Example 1, injection can be performed immediately after clamping, whereas in Reference Example 1, injection can be performed after 60 seconds of impregnation time after clamping, indicating that Example 1 is superior in productivity. In Reference Example 2, since the yarn 4 has glass fibers and thermoplastic resin fibers alternately arranged, the glass fibers tend to break during the processing operation.

1 Fabric 2 Reinforcing fiber 3 Groove through which resin is injected

Claims (11)

After hot-pressing a fabric composed of reinforcing fibers and thermoplastic resin fibers with an open press machine, further molding using a closed mold,
At least one of the warp and weft constituting the fabric is a covering yarn, a method for producing a fiber-reinforced resin molded product,
The molding using the closed system mold is hybrid molding with a composition containing a thermoplastic resin,
A method for producing a fiber-reinforced resin molded product, wherein the hybrid molding includes placing the hot-pressed fabric in a closed mold and then injecting and molding a composition containing a thermoplastic resin. The production of a fiber-reinforced resin molded product according to claim 1 , wherein the thermoplastic resin contained in the composition containing the thermoplastic resin is a thermoplastic resin of the same family as the thermoplastic resin contained in the thermoplastic resin fibers. Method. 3. The method for producing a fiber-reinforced resin molded article according to claim 1, wherein the fabric composed of the reinforcing fibers and the thermoplastic resin fibers is one ply. A method for producing a fiber-reinforced resin molded product according to any one of claims 1 to 3 , comprising laminating two or more plies of fabrics composed of reinforcing fibers and thermoplastic resin fibers. The method for producing a fiber-reinforced resin molded product according to any one of claims 1 to 4 , wherein at least one of the warp and weft constituting the fabric is a covering yarn containing a reinforcing fiber as a core yarn. The fiber reinforcement according to any one of claims 1 to 4 , wherein at least one of the warp yarn and the weft yarn constituting the woven fabric is a covering yarn in which the core yarn is a reinforcing fiber and the sheath yarn is a thermoplastic resin fiber. A method for manufacturing a resin molded product. 7. The method for producing a fiber-reinforced resin molded product according to claim 6 , wherein at least one of the warp and weft that constitute the woven fabric is a yarn obtained by spirally winding thermoplastic resin fibers in the longitudinal direction of the reinforcing fibers. . The method for producing a fiber-reinforced resin molded product according to any one of claims 1 to 7 , wherein the reinforcing fiber contains at least one of carbon fiber, aramid fiber and glass fiber. The method for producing a fiber-reinforced resin molded product according to any one of claims 1 to 8 , wherein the thermoplastic resin fibers contain a polyamide resin. The thermoplastic resin fiber contains a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, 50 mol% or more of the diamine-derived structural unit is derived from xylylenediamine, and 50 mol% of the dicarboxylic acid-derived structural unit. The method for producing a fiber-reinforced resin molded product according to any one of claims 1 to 8 , wherein the above comprises a polyamide resin derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. The method for producing a fiber-reinforced resin molded product according to any one of claims 1 to 9 , wherein the orientation retention rate of the reinforcing fibers on the surface of the fabric after hot pressing is less than 95%; The retention rate is defined by selecting five areas of 10 mm x 10 mm from the press-molded product so as to be orthogonal to the warp and weft, selecting one reinforcing fiber of the warp from each area, and the reinforcing fiber is the straight line distance of the press-molded product. The length required to pass through 10 mm is measured, and the average value of the maintenance rate obtained from the following formula;
Retention rate = [10 mm/(length (mm) required for the reinforcing fiber to pass through a linear distance of 10 mm] x 100 (unit: %).

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