JP6246580B2 - Fabric-reinforced resin molded body manufacturing method and fabric-reinforced resin molded body - Google Patents

Description

  The present invention relates to a method for producing a fabric-reinforced resin molded body and a fabric-reinforced resin molded body. More specifically, the present invention relates to a method of manufacturing a resin molded body using a fabric such as a woven fabric, a knitted fabric, and a nonwoven fabric as a reinforcing material, and a resin molded body manufactured by this method.

  In recent years, resin molded products are frequently used for travel suitcases for reasons such as light weight. On the other hand, resin suitcases are handled as cargo when checked in as baggage when boarding an airplane, and may be damaged, cracked, broken, or perforated during transportation. Conventionally, fiber reinforced plastics (FRP) are used for such resin molded bodies that require high strength.

  In addition, a fabric reinforced resin molded body using a fabric as a reinforcing material has been proposed (see Patent Documents 1 and 2). For example, Patent Documents 1 and 2 disclose resin molded bodies obtained by compression molding by impregnating a woven sheet obtained by plain weaving of carbon fiber or aramid fiber with a thermosetting epoxy resin.

Japanese Patent Laid-Open No. 5-208471 JP 2009-184239 A

  However, a resin molded body using fiber reinforced plastic is liable to be warped after heat molding and has a problem in shape retention. The problem of “warping” after molding is particularly remarkable when deep drawing is performed. In addition to the above-described shape retention, the fabric reinforced resin molded article using the woven fabric sheet described in Patent Documents 1 and 2 has a problem that the manufacturing cost increases because the reinforcing material is expensive. is there.

  Accordingly, the main object of the present invention is to provide a method for producing a fabric-reinforced resin molded body and a fabric-reinforced resin molded body in which warpage hardly occurs after molding.

  In fiber reinforced plastics, the fiber that is the reinforcing material is partially stretched during thermoforming, but the partial stretching strain applied to the reinforcing fiber is relaxed after molding, and the molded body warps. Conceivable. Therefore, the present inventor conducted earnest experiments on the reinforcing material and the molding method, and united two or more composite fibers each provided with a coating layer made of a thermoplastic resin around the fibrous reinforcing material. The present inventors have found that a fabric formed using a linear composite material can be molded by a specific method to obtain a fabric-reinforced resin molded body free from warpage.

That is, the method for producing a fabric-reinforced resin molded body according to the present invention heats a fabric formed of a linear composite material obtained by integrating two or more composite fibers by heat stretching or a sheet material using the fabric. And a step of compressing or vacuum forming a heated fabric or sheet material using a mold in a cold state, wherein the composite fiber is a fibrous reinforcement and the fibrous reinforcement A coating layer made of a thermoplastic resin provided around the material, and the linear composite material is made of a thermoplastic resin in which the coating layers of each composite fiber are fused and integrated to form the coating layer. A matrix resin in which the fibrous reinforcing material is present is used.
As the fibrous reinforcing material, for example, a differential scanning calorimeter can be used, and the crystallinity measured by the melting calorimetry method can be 60% or more at a temperature rising rate of 30 ° C./min.
In addition, a polyolefin resin having a melting point of 130 ° C. or lower can be used for the matrix resin, and a crystalline thermoplastic resin having a melting point of 20 ° C. higher than that of the polyolefin resin can be used for the fibrous reinforcing material. it can.
The linear composite material may include two or more kinds of fibrous reinforcing materials.
As the linear composite material, one having a tensile Young's modulus at 120 ° C. of 7 cN / dtex or more can be used.
On the other hand, what is necessary is just to make the said fabric or sheet material into the temperature more than melting | fusing point of the said matrix resin, and less than melting | fusing point of the said fibrous reinforcement in the said heating process.
The sheet material includes a plurality of the fabrics laminated and thermocompression bonded at a temperature at which the matrix resin melts, or a resin sheet made of one or more fabrics and the same type of resin as the matrix resin. And thermocompression-bonded at a temperature at which the matrix resin melts.
The fabric is, for example, a plain woven fabric.

  The fabric-reinforced resin molded body according to the present invention is a mold formed by heating a fabric formed of a linear composite material obtained by integrating two or more composite fibers by heat stretching or a sheet material using the fabric. The composite fiber obtained by compression molding or vacuum molding using cold is composed of a fibrous reinforcing material and a coating layer made of a thermoplastic resin provided around the fibrous reinforcing material. In the linear composite material, the fibrous reinforcing material is present in a matrix resin made of a thermoplastic resin that forms a coating layer by fusing and integrating the coating layers of the composite fibers.

  The term “fabric” as used herein includes all fabrics formed using linear composite materials such as woven fabrics, knitted fabrics and nonwoven fabrics, and “fabric reinforced resin moldings” are resins reinforced by these fabrics. Refers to a molded body.

  According to the present invention, using a fabric formed using a linear composite material in which two or more composite fibers provided with a coating layer made of a thermoplastic resin are provided around a fibrous reinforcing material. Therefore, it is possible to manufacture a fabric-reinforced resin molded body that hardly warps after molding.

It is a flowchart figure which shows the manufacturing method of the fabric reinforcement | strengthening resin molding of embodiment of this invention. AC is a schematic diagram which shows the manufacturing method of the fabric reinforced resin molding shown in FIG. 1 in order of the process. It is sectional drawing which shows the structure of a composite fiber typically. FIGS. 4A to 4C are cross-sectional views schematically showing a structural example of a linear composite material obtained by heating and stretching the composite fiber 3 shown in FIG. 3. FIGS. 4A to 4C are cross-sectional views schematically showing other structural examples of a linear composite material obtained by heating and stretching the composite fiber 3 shown in FIG. 3. FIGS. 4A to 4C are cross-sectional views schematically showing other structural examples of a linear composite material obtained by heating and stretching the composite fiber 3 shown in FIG. 3. It is a perspective view which shows typically the fabric (plain woven fabric) using the linear composite material shown to FIGS. It is a perspective view which shows the structural example of the fabric reinforcement | strengthening resin molding of embodiment of this invention. A and B are schematic views showing a method for evaluating warpage.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments described below.

  FIG. 1 is a flowchart showing a method for manufacturing a fabric reinforced resin molded body according to an embodiment of the present invention, and FIGS. 2A to 2C are schematic views showing the method for manufacturing the fabric reinforced resin molded body shown in FIG. is there. As shown in FIG.1 and FIG.2, in the manufacturing method of the fabric reinforcement | strengthening resin molding (henceforth a resin molding) of this embodiment, the linear form obtained by heat-drawing two or more composite fibers A process of heating the fabric 11 or the sheet material 12 formed by the composite material (heating process S1) and a process of molding the heated fabric 11 or the sheet material 12 (molding process S2) are performed.

[Composite fiber]
FIG. 3 is a cross-sectional view schematically showing the structure of the composite fiber. The raw yarn of the linear composite material used in the method for producing a resin molded body of this embodiment is a composite fiber 3 in which a coating layer 2 made of a thermoplastic resin is provided around the fibrous reinforcing material 1 shown in FIG. . The composite fiber 3 can be formed by, for example, melt spinning.

  The coating layer 2 of the composite fiber 3 can be molded at a relatively low temperature and has a melting point of 130 ° C. or less measured at a heating rate of 10 ° C./min using a differential scanning calorimeter from the economical viewpoint. It is preferable to use a resin. Specifically, low density polyethylene, linear low density polyethylene, high density polyethylene, ethylene-based resins such as ethylene vinyl acetate, and binary or ternary copolymers of α-olefins such as ethylene and butene and propylene Random or block copolymerized polypropylene, etc. can be used. Among these polyolefin-based resins, low-density polyethylene, linear low-density polyethylene, and high-density polyethylene are preferable because they have a clear melting point and show a sharp melting behavior with respect to temperature.

  On the other hand, as the fibrous reinforcement 1, for example, synthetic fibers such as polyester fibers, natural fibers such as cotton, metal fibers such as steel fibers, glass fibers, carbon fibers, graphite fibers, ceramic fibers, and the like can be used. The material is not particularly limited. Among various fibrous reinforcing materials, synthetic fibers are preferable from the viewpoint of production, and those using crystalline resins are particularly preferable.

  It is necessary that the fibrous reinforcing material 1 does not melt even in the state of a molded body from the time of fiber production. Therefore, when synthetic fibers are used for the fibrous reinforcing material 1, it is preferable to use those made of a crystalline thermoplastic resin whose melting point is 20 ° C. or higher than that of the thermoplastic resin constituting the coating layer 2. For example, when the coating layer 2 is formed of a polyolefin resin having a melting point of 130 ° C. or lower as described above, the crystalline thermoplastic resin used for the fibrous reinforcement 1 may be isotactic polypropylene (i-PP), Examples thereof include polyethylene terephthalate (PET) and nylon.

[Linear composite]
The linear composite material used in the method for producing a resin molded body of the present embodiment is obtained by bundling a plurality of the composite fibers 3 described above and heating and stretching them. 4-6 is sectional drawing which shows typically the structural example of the linear composite material obtained by heat-stretching the composite fiber 3 shown in FIG. When two or more composite fibers 3 are heated and stretched, the coating layers 2 of the respective composite fibers 3 are fused and integrated, and the fibers are reinforced in the matrix resin 5 (the thermoplastic resin constituting the coating layer 2) in the cross section in the longitudinal direction. A linear composite material having a structure in which the material 1 exists is obtained.

  The presence state of the fibrous reinforcing material 1 is not particularly limited, and may be randomly dispersed in the matrix resin 5 in the cross section in the longitudinal direction as shown in FIG. 4A, and the fiber as shown in FIG. 4B. Part of the reinforcing material 1 may be present in contact. Moreover, as shown to FIG. 4C, in the matrix resin 5, the 2 or more types of fibrous reinforcement 1a, 1b from which a material and thickness differ may exist.

  Further, the thickness and shape of the fibrous reinforcement 1 are not particularly limited, and those having a large diameter as shown in FIG. 5A and those having an elliptical cross section as shown in FIG. May be arranged regularly or irregularly. As shown in FIG. 5C, two types of fibrous reinforcing materials 1c and 1d having different shapes may be arranged so as to intersect each other. In addition, as shown to FIG. 6A-C, the space | gap 4 may exist in the matrix resin 5 or the fibrous reinforcement 1.

  Here, the drawing conditions of the composite fiber 3 are not particularly limited, but the drawing temperature is preferably set to 145 ° C. or more from the viewpoint of improving the fiber properties. On the other hand, when the fibrous reinforcing material 1 is a synthetic fiber, it is preferable that the draw ratio is higher from the viewpoint of increasing the crystallinity of the fibrous reinforcing material 1. However, if the draw ratio is too high, the crystal orientation is disturbed and the degree of crystallinity is lowered. Therefore, the composite fiber 3 in which the fibrous reinforcing material 1 is a synthetic fiber is preferably drawn in multiple stages rather than one stage. When stretched in one step, a large stretch ratio is applied at a stretch. Therefore, stretching is started before the material to be stretched enters the heating tank, and particularly neck (necking) stretching is started extremely, and as a result, oriented crystals are hardly formed. Because.

  For example, when a linear composite material is formed by two-stage stretching, it is preferable to perform the first stage with warm water and the second stage in highly saturated steam. In that case, from the viewpoint of improving the crystallinity of the fibrous reinforcing material 1, it is preferable to set the draw ratio of the second stage to 1.5 to 2.5 times. When the draw ratio of the second stage is less than 1.5 times, the oriented crystal formed in the first stage may be disturbed and the crystallinity may be lowered. On the other hand, when the draw ratio at the second stage exceeds 2.5, thread breakage may occur or the oriented crystal may be broken and the crystallinity may be lowered.

  In addition, when the linear composite material is formed by two-stage stretching, the first-stage stretching ratio is not particularly limited, but can be set to 4.0 to 10.0 times, for example. Further, the drawing of the raw yarn 3 is not limited to two stages, and may be performed in three or more stages.

  And the fibrous reinforcement 1 of the linear composite material used with the manufacturing method of the resin molding of this embodiment was measured by the calorific value method using a differential scanning calorimeter at a heating rate of 30 ° C./min. The crystallinity is preferably 60% or more. When the degree of crystallinity of the fibrous reinforcing material 1 is less than 60%, distortion occurs during molding, and the molded body warps. On the other hand, by setting the degree of crystallinity of the fibrous reinforcing material 1 to 60% or more, it is possible to reduce distortion generated during molding and to produce a resin molded body without warping.

  The degree of crystallinity of the fibrous reinforcement 1 of the linear composite material defined here is a value calculated from the heat of fusion of the fibrous reinforcement 1 measured using a differential scanning calorimeter (DSC). In calculating the degree of crystallinity, the reference value of heat of fusion (209 J / g, temperature increase rate 10 ° C./min) in the complete crystal of the resin constituting the fibrous reinforcing material 1 was set to 100% crystallinity. The measured amount of the fibrous reinforcing material 1 was about 10 mg, and the temperature was scanned from room temperature to a temperature 30 to 40 ° C. higher than the melting point of the fibrous reinforcing material 1 at a heating rate of 30 ° C./min.

  When the melting point of a resin is measured using DSC, the rate of temperature increase is generally set to 10 ° C./min. However, the amount of heat of fusion of oriented crystallization such as a stretched product is measured, and the fiber is measured. When obtaining the difference in the degree of crystallinity, if the rate of temperature rise is slow, crystallization proceeds during temperature rise, and the amount of heat of fusion in a state different from that before measurement is measured. Therefore, in the present embodiment, the degree of crystallinity of the fibrous reinforcing material 1 is defined by a value measured at a temperature increase rate of 30 ° C./min.

  Furthermore, it is preferable that the linear composite material used in the method for producing a resin molded body of this embodiment has a tensile Young's modulus at 120 ° C. of 7 cN / dtex or more. Thereby, the distortion which generate | occur | produces at the time of shaping | molding can be made small.

[Fabric 11 sheet material 12]
The fabric used in the method for producing a resin molded body of the present embodiment is produced using the above-described linear composite material, and is, for example, a woven fabric, a knitted fabric, or a nonwoven fabric. In addition, the fabric used in the present embodiment only needs to use the above-described linear composite material, and different fiber types may be mixed. FIG. 7 is a perspective view schematically showing a plain woven fabric which is an example of the fabric. The structure of the fabric 11 is not particularly limited, and can be appropriately selected according to applications such as a plain weave, a satin weave, a deformed structure of these original structures, in addition to the plain weave shown in FIG. Moreover, the manufacturing method of a fabric is not specifically limited, either, A well-known method can be applied.

  Furthermore, in the method for producing a resin molded body of the present embodiment, the above-described fabric can be used alone, but a sheet material obtained by laminating a plurality of fabrics and thermocompression bonding at a temperature at which the matrix resin 5 melts, Alternatively, it is preferable to use a sheet material obtained by laminating two or more fabrics and a resin sheet made of the same kind of resin as the matrix resin 5 and thermocompression bonding at a temperature at which the matrix resin 5 melts.

  Thus, by thermocompression-bonding the fabric into a sheet, the degree of crystallinity of the fibrous reinforcing material 1 can be increased, and the operability in the heating step S1 and the molding step S2 can be improved. In addition, the sheet material in which the resin sheet is laminated on the fabric can reduce the moisture permeability and air permeability that are the characteristics of the fabric, so that it can be applied to applications that dislike water permeability such as home appliances, and vacuum forming methods. Can also be applied.

  In addition, in the manufacturing method of the resin molding of this embodiment, even if the film which consists of polyolefin, polyester, or ABS (acrylonitrile butadiene styrene copolymer) resin is bonded together on the single side | surface or both surfaces of the fabric or sheet material mentioned above. Good. Thereby, it becomes possible to color the surface of a resin molding or to give design properties, such as a pattern.

[Heating step S1]
As shown in FIGS. 2A and 2B, in the heating step S <b> 1, the fabric 11 or the sheet material 12 using the fabric is heated after being cut or laminated as necessary. At that time, the heating method is not particularly limited, and a known heating device such as an oven or a hot plate can be used. Moreover, you may heat the fabric 11 or the sheet | seat material 12 in the state clamped with the metal plate etc. as needed. Thereby, thermal contraction can be prevented. The heating temperature of the fabric 11 or the sheet material 12 is preferably set to a temperature equal to or higher than the melting point of the matrix resin 5 and lower than the melting point of the fibrous reinforcing material 1. Thereby, a fabric reinforced resin molded article having good shape retention (shape retention) can be obtained.

[Molding step S2]
FIG. 8 is a perspective view showing a configuration example of a fabric reinforced resin molded body manufactured by the method of the present embodiment. As shown in FIG. 2C, the fabric 11 or the sheet material 12 heated in the heating step S1 described above is compression-molded or vacuum-molded using the molds 13a and 13b while being cold. Thereby, for example, substantially box-shaped bodies such as the deep-drawn molded body 20 shown in FIG. 8 can be manufactured, and fabric-reinforced resin molded bodies having various shapes can be manufactured.

  The conditions at the time of compression molding and vacuum molding are not particularly limited. For example, the pressure is 1 to 5 MPa, the temperature of the fabric 11 or the sheet material 12 is 120 to 150 ° C., and the cooling time is 30 to 60 seconds. To do. In addition, in the manufacturing method of the resin molding of this embodiment, although it shape | molds in cold, this is in order to manufacture efficiently the fabric reinforcement | strengthening resin molding with favorable shape retainability (shape retention). It is.

  As described above in detail, in the method for producing a resin molded body according to the present embodiment, two or more composite fibers each provided with a coating layer around a fibrous reinforcing material are bundled and heated to stretch, and the coating layers of the fibers are fused. Since the fabric formed by the linear composite material obtained by integration is used, a resin molded body in which the reinforcing material and the matrix resin are integrated is obtained. Thereby, the intensity | strength of a molded object can be raised.

  Further, in the method for producing a resin molded body according to the present embodiment, since pre-heating is performed at a temperature lower than the melting point of the fibrous reinforcing material and then cold forming is performed, each fiber constituting the fabric is distorted. It can be prevented from occurring. As a result, the shape retention of the molded body can be improved. The method for producing a resin molded body according to the present embodiment is suitable for producing a resin molded body using a woven fabric, a knitted fabric, and a nonwoven fabric, but is particularly effective when a woven fabric having poor stretchability is used as a reinforcing material.

  Hereinafter, the effects of the present invention will be specifically described with reference to Examples and Comparative Examples of the present invention. In this example, a resin molded body was produced using a plain woven fabric formed from a linear composite material produced by the following method and conditions, and the performance was evaluated.

<Linear composite material A>
First, a linear reinforcement is formed around a fibrous reinforcement made of isotactic polypropylene (i-PP) [melt flow rate (MFR) = 18 g / 10 min (230 ° C., 21.18 N), melting point = 165 ° C.]. A composite fiber provided with a coating layer made of low density polyethylene (LLDPE) [melt flow rate (MFR) = 8 g / 10 min (190 ° C., 21.18 N), melting point = 117 ° C.] was produced. Specifically, a predetermined amount of these materials are mixed with a molten resin gear pump attached to the spinning nozzle head at a spinning temperature of 270 ° C. using a sheath-core composite spinning nozzle having pores with 240 holes. Spinning at a spinning speed of 60 m / min while measuring the amount of discharged resin, composite fibers having a sheath / core cross-sectional area ratio (sheath / core ratio) of 35/65 and a fineness of 24,163 dtex were produced.

  Subsequently, the obtained composite fiber (240 fibers) was subjected to a first draw roller (G1) = 60 m / min, a first drawing tank drawing temperature = 95 ° C. (warm water), a first drawing by a spin draw method (spinning drawing direct connection method). 2 stretching roller (G2) speed = 405 m / min, 2nd stretching tank temperature = 153 ° C. (high pressure saturated steam), 3rd stretching roller (G3) speed = 805 m / min, 1st stretching ratio (G2 / G1 speed ratio) ) = 6.75 times, second draw ratio (G3 / G2 speed ratio) = 1.99 times, and total draw ratio (G3 / G1 speed ratio) = 13.42 times. Through this stretching process, LLDPE, which is a matrix resin, was melted, and a stretched linear composite material A in which a fibrous reinforcing material (i-PP) was embedded and integrated was obtained.

  The physical properties of the drawn linear composite material A were fineness = 1828 dtex, tensile Young's modulus = 93 cN / dtex (room temperature tensile test), and 13.2 cN / dtex (120 ° C. hot tensile test). Further, for the obtained stretched linear composite material A, the heat of fusion of the fibrous reinforcing material (i-PP) is measured with a differential scanning calorimeter (DSC) under the condition of a temperature rising rate of 30 ° C./min. The degree of crystallinity was calculated from the comparison with the heat of fusion of the complete crystal of i-PP resin. As a result, the crystallinity of the fibrous reinforcing material (i-PP) was 72%.

<Linear composite material B>
A composite fiber was produced by the same method and conditions as the linear composite material A described above except that the amount of resin discharged from the gear pump was adjusted, the spinning speed was 40 m / min, and the spinning fineness was 17,809 dtex. Thereafter, the first stretching roller (G1) is 40 m / min, the first stretching tank stretching temperature is 145 ° C. (high-pressure saturated steam), the second stretching roller (G2) speed is 400 m / min, and the total stretching ratio (G2 / G1). The stretched linear composite material B was obtained by the same method and conditions as the composite fiber A described above except that the film was stretched one step under the condition of (speed ratio) = 10.00 times.

  The physical properties of the drawn linear composite material B were fineness = 1808 dtex, tensile Young's modulus = 59 cN / dtex (room temperature tensile test), and 7.1 cN / dtex (120 ° C. hot tensile test). Moreover, it measured by the method similar to the linear composite material A, and the crystallinity degree of the fibrous reinforcement (i-PP) computed was 60%.

<Linear composite material C>
A composite fiber was produced by the same method and conditions as the linear composite material A described above, except that the amount of resin discharged from the gear pump was adjusted and the spinning fineness was set to 12,544 dtex. Thereafter, the second stretching roller (G2) speed was 300 m / min, the second stretching tank temperature was 145 ° C. (high-pressure saturated steam), the third stretching roller (G3) speed was 420 m / min, and the first stretching ratio (G2 / G1 speed ratio) is 5.00 times, the second draw ratio (G3 / G2 speed ratio) is 1.40 times, and the total draw ratio (G3 / G1 speed ratio) is 7.00 times. A stretched linear composite material C was obtained by two-stage stretching under the same method and conditions as the linear composite material A.

  The physical properties of the drawn linear composite material C were fineness = 1814 dtex, tensile Young's modulus = 36 cN / dtex (room temperature tensile test), and 4.9 cN / dtex (120 ° C. hot tensile test). Moreover, it measured by the method similar to the linear composite material A, and the crystallinity degree of the fibrous reinforcement (i-PP) computed was 52%. The linear composite material C exhibits extremely lower physical properties than the above-described linear composite material A and linear composite material B in Young's modulus and crystallinity in the hot tensile test, and is assumed to have poor heat resistance. It was done. This is presumed to be caused by the fact that the draw ratio is lower than that of the fiber of the example.

<Linear composite material D>
A composite fiber was produced by the same method and conditions as the linear composite material A described above except that the amount of resin discharged from the gear pump was adjusted and the spinning fineness was 25,045 dtex. Thereafter, the second stretching roller (G2) speed is 600 m / min, the third stretching roller (G3) speed is 838 m / min, the first stretching ratio (G2 / G1 speed ratio) is 10.00 times, and the second stretching ratio. Two-stage stretching under the same method and conditions as the linear composite A described above except that (G3 / G2 speed ratio) is 1.40 times and the total draw ratio (G3 / G1 speed ratio) is 13.97 times. Thus, a stretched linear composite material D was obtained.

  The physical properties of the drawn linear composite material D were fineness = 1820 dtex, tensile Young's modulus = 82 cN / dtex (room temperature tensile test), and 6.8 cN / dtex (120 ° C. hot tensile test). Moreover, it measured by the method similar to the linear composite material A, and the crystallinity degree of the fibrous reinforcement (i-PP) computed was 58%. This linear composite material D is considered to exhibit lower physical properties than the above-described linear composite material A and linear composite material B in Young's modulus and crystallinity in the hot tensile test, and to be inferior in heat resistant physical properties. It was. From this, it is not always possible to achieve improved heat resistance by stretching at a high magnification, and the oriented crystal formed by the first-stage stretching grows because the second-stage stretching ratio, which is higher-temperature stretching than the first stage, is lower. Rather than letting go, it is presumed that it is rather destroyed.

<Linear composite E>
A composite fiber was produced by the same method and conditions as those of the linear composite material B described above, except that the amount of resin discharged from the gear pump was adjusted and the spinning fineness was 24,959 dtex. Thereafter, the second stretching roller (G2) speed was set to 560 m / min, and the same method as that for the linear composite material B described above, except that the stretching was performed under the condition of the total stretching ratio (G2 / G1 speed ratio) = 14.0 times. And it extended | stretched 1 step on condition, and the extending | stretching linear composite material E was obtained.

  The physical properties of the drawn linear composite material E were fineness = 1810 dtex, tensile Young's modulus = 71 cN / dtex (room temperature tensile test), and 6.5 cN / dtex (120 ° C. hot tensile test). Moreover, it measured by the method similar to the linear composite material A, and the crystallinity degree of the fibrous reinforcement (i-PP) calculated was 57%. This linear composite material E is assumed to exhibit lower physical properties than the above-mentioned linear composite material A and linear composite material B in Young's modulus and crystallinity in the hot tensile test, and to be inferior in heat resistance physical properties. It was. From this, as with the linear composite material D described above, it is not possible to promote the orientation and increase the crystallinity by stretching at a high magnification. It is presumed that stretching accompanied by neck (necking) deformation of the reinforcing material (i-PP) increases and orientation crystallization is suppressed.

<Linear composite material F>
The coating layer was formed of ethylene-propylene random copolymer (co-PP) [melt flow rate (MFR) = 5 g / 10 min (190 ° C., 21.18 N), melting point = 125 ° C.], and discharge of gear pump A composite fiber was produced by the same method and conditions as the linear composite material A described above except that the amount of resin was adjusted and the spinning fineness was 24,100 dtex. Thereafter, two-stage stretching was performed under the same method and conditions as the linear composite material A described above to obtain a stretched linear composite material F.

  The physical properties of the drawn linear composite material F were fineness = 1820 dtex, tensile Young's modulus = 95 cN / dtex (room temperature tensile test), and 95 cN / dtex (120 ° C. hot tensile test). Moreover, it measured by the method similar to the linear composite material A, and the crystallinity degree of the fibrous reinforcement (i-PP) computed was 71%.

  The production conditions and fiber properties other than those described above are summarized in Table 1 below for these linear composite materials A to F.

The “tensile strength” shown in Table 1 is a value measured by the following method.
(1) Room temperature According to the method defined in JIS L1013, using Autograph AG-100kN IS manufactured by Shimadzu Corporation under the conditions of a sample length of 100 mm and a tensile speed of 100 mm / min, 5 times per sample Measurements were made. And the intensity | strength (cN / dtex), elongation (%), and Young's modulus (cN / dtex) were calculated | required from the average value.

(2) 120 ° C
After adjusting for 1 hour in a 120 ° C atmosphere using a heating furnace, set the sample, and after 3 minutes (the temperature of the sample reaches 120 ° C after about 2 minutes), follow the method specified in JIS L1013. Accordingly, measurement was performed 5 times per sample using Autograph AG-100kN IS manufactured by Shimadzu Corporation under the conditions of a sample length of 100 mm and a pulling speed of 100 mm / min. And the intensity | strength (cN / dtex), elongation (%), and Young's modulus (cN / dtex) were calculated | required from the average value.

Example 1
(1) Fabrication Fabrication A plain woven fabric was fabricated by combining two linear composite materials A to 3656 dtex, and using a loom to set the original yarn punching density in the longitudinal and lateral directions to 8.33 yarns / 25 mm, respectively. The surface density of the obtained woven fabric was 244 g / m ² .

(2) Production of sheet material The obtained plain woven fabric was cut into a size of 1.5 m in length and width, and three of these were laminated and heated using a hot plate (2 m in length x 2 m in width) with a hot press machine. A thermocompression fabric sheet was prepared. As a preparation for preparing a sheet, an aluminum plate having a length and width of 1.8 m and a thickness of 1.5 mm was preheated to a predetermined temperature with a hot press machine in advance. Then, the above-described plain woven fabric was placed on the aluminum plate and thermocompression bonded under predetermined conditions. After releasing the press pressure, the entire aluminum plate was taken out, and a separately prepared aluminum plate for cooling was placed on the plate to quench the sheet, and then only the sheet was removed to prepare a thermocompression fabric sheet. At that time, the hot press conditions were a flat plate temperature of 120 ° C., a pressure of 1.6 MPa, and a pressure holding time of 45 seconds. The obtained thermocompression bonded fabric sheet had a thickness of 1.1 mm and an area density of 681 g / m ² .

(3) Compression molding test In the compression molding test, a male mold having a convex shape having a vertical length of 500 mm, a horizontal length of 700 mm, a height of 120 mm, a top end curvature R80 mm, and a bottom end curvature R10 mm was used. On the other hand, as the female mold, a mold having a concave shape corresponding to the male mold was used, and the male and female molds were mounted on a press machine and used for the compression molding test. Each mold was used in such a state that the mold temperature could be maintained in the range of 30 ° C. to 70 ° C. by passing cold water or hot water through the in-mold water cooling tube.

  The upper and lower surfaces of the fabric sheet described above were preheated with a far infrared (IR) heater until the surface temperature reached 120 ° C to 130 ° C. After reaching the predetermined temperature, the fabric sheet was quickly inserted into the compression test mold, compression molding was performed for 4 seconds with the clearance between the male and female molds being 1 mm, and then cold molding was maintained for 60 seconds. After the cold forming was completed, the mold was removed to obtain a box-shaped formed body.

  Next, the box-shaped molded body was allowed to stand at room temperature for 24 hours and then visually observed for shapes such as warpage and deformation, and the degree of warpage of the side wall surface with respect to the bottom surface was measured as a warpage angle α (°). 9A and 9B are schematic views showing a method for evaluating warpage. As shown in FIG. 9A, the warp angle α (°) is α = 0 ° when the angle θ formed by the bottom portion and the side wall portion of the box-shaped molded body is 90 °, and the side wall portion is inward as shown in FIG. 9B. The case of warping was determined as + θ °, and the case of warping to the bottom side was determined as −θ °. As a result, warpage and deformation were not recognized in the obtained box-shaped molded article, and the warp angle α was 0 °, which was good moldability.

(Example 2)
In addition to the woven fabric, a sheet made of LLDPE resin having a surface density of 200 g / m ² [melt flow rate (MFR) = 8 g / 10 minutes (190 ° C., 21.18 N), melting point = 117 ° C.] was laminated on one side A thermocompression bonded fabric sheet was produced by the same method and conditions as in Example 1 described above. The obtained thermocompression bonded fabric sheet had a thickness of 1.3 mm and an area density of 865 g / m ² .

  Next, the thermocompression bonded fabric sheet produced by the above-described method was placed so that the surface on the woven fabric side was in contact with the male side of the mold, and a compression molding test was conducted under the same method and conditions as in Example 1. As a result, in the visual observation after standing at room temperature for 24 hours, no warpage or deformation was observed in the box-shaped molded body, and the warp angle α was 0 °, indicating good moldability.

(Example 3)
In addition to woven fabric, sheet made of LLDPE resin having a surface density of 200 g / m ² [melt flow rate (MFR) = 8 g / 10 min (190 ° C., 21.18 N), melting point = 117 ° C.] sheet through PET resin sheet A thermocompression bonded fabric sheet was produced by the same method and conditions as in Example 1 except that was laminated on one side. The obtained thermocompression bonded fabric sheet had a thickness of 1.3 mm and an area density of 865 g / m ² .

  Next, the thermocompression bonded fabric sheet produced by the above-described method was placed so that the surface on the woven fabric side was in contact with the male side of the mold, and a compression molding test was conducted under the same method and conditions as in Example 1. As a result, in the visual observation after standing at room temperature for 24 hours, no warpage or deformation was observed in the box-shaped molded body, and the warp angle α was 0 °, indicating good moldability.

Example 4
Three sheets of woven fabric produced by the same method as in Example 1 were laminated without performing hot plate hot pressing to obtain a surface density equivalent to 732 g / m ² , and compression molded under the same method and conditions as in Example 1. A test was conducted. As a result, in the visual observation after standing at room temperature for 24 hours, no warpage or deformation was observed in the box-shaped molded body, and the warp angle α was 0 °, indicating good moldability.

(Example 5)
A plain woven fabric was produced by the same method and conditions as in Example 1 except that two linear composite materials B were combined to give 3616 dtex. The surface density of the obtained woven fabric was 241 g / m ² . Using this woven fabric, a thermocompression bonded fabric sheet was produced by the same method and conditions as in Example 1 described above. The obtained thermocompression bonded fabric sheet had a thickness of 1.1 mm and an area density of 670 g / m ² .

  Next, a compression molding test was performed under the same method and conditions as in Example 1 using the thermocompression bonded fabric sheet produced by the method described above. As a result, in the visual observation after standing at room temperature for 24 hours, no warpage or deformation was observed in the box-shaped molded body, and the warp angle α was 0 °, indicating good moldability.

(Example 6)
Using the plain woven fabric produced in Example 5, a thermocompression bonded fabric sheet was produced by the same method and conditions as in Example 2. The obtained thermocompression bonded fabric sheet had a thickness of 1.3 mm and an areal density of 853 g / m ² . Next, the thermocompression bonded fabric sheet produced by the above-described method was placed so that the surface on the woven fabric side was in contact with the male side of the mold, and a compression molding test was conducted under the same method and conditions as in Example 1. As a result, in the visual observation after standing at room temperature for 24 hours, no warpage or deformation was observed in the box-shaped molded body, and the warp angle α was 0 °, indicating good moldability.

(Example 7)
Three sheets of woven fabric produced by the same method as in Example 5 were laminated without performing hot plate hot pressing to obtain a surface density equivalent to 723 g / m ² , and compression molded under the same method and conditions as in Example 1. A test was conducted. As a result, in the visual observation after standing at room temperature for 24 hours, no warpage or deformation was observed in the box-shaped molded body, and the warp angle α was 0 °, indicating good moldability.

(Example 8)
A plain woven fabric was produced by the same method and conditions as in Example 1 except that two linear composite materials F were combined to give 3640 dtex. The surface density of the obtained woven fabric was 242 g / m ² . Using this woven fabric, a thermocompression bonded fabric sheet was produced by the same method and conditions as in Example 1 described above. The obtained thermocompression bonded fabric sheet had a thickness of 1.1 mm and an areal density of 681 g / m ² .

  Next, a compression molding test was performed under the same method and conditions as in Example 1 using the thermocompression bonded fabric sheet produced by the method described above. As a result, in the visual observation after standing at room temperature for 24 hours, no warpage or deformation was observed in the box-shaped molded body, and the warp angle α was 0 °, indicating good moldability.

Example 9
Using the plain woven fabric produced in Example 8, a thermocompression bonded fabric sheet was produced by the same method and conditions as in Example 2. The obtained thermocompression bonded fabric sheet had a thickness of 1.3 mm and an area density of 865 g / m ² . Next, the thermocompression bonded fabric sheet produced by the above-described method was placed so that the surface on the woven fabric side was in contact with the male side of the mold, and a compression molding test was conducted under the same method and conditions as in Example 1. As a result, in the visual observation after standing at room temperature for 24 hours, no warpage or deformation was observed in the box-shaped molded body, and the warp angle α was 0 °, indicating good moldability.

(Example 10)
Using the plain woven fabric produced in Example 8, a thermocompression bonded fabric sheet was produced by the same method and conditions as in Example 3. The obtained thermocompression bonded fabric sheet had a thickness of 1.4 mm and an areal density of 916 g / m ² . Next, the thermocompression bonded fabric sheet produced by the above-described method was placed so that the surface on the woven fabric side was in contact with the male side of the mold, and a compression molding test was conducted under the same method and conditions as in Example 1. As a result, in the visual observation after standing at room temperature for 24 hours, no warpage or deformation was observed in the box-shaped molded body, and the warp angle α was 0 °, indicating good moldability.

(Example 11)
Three sheets of woven fabric produced by the same method as in Example 8 were laminated without performing hot plate hot pressing to obtain a surface density equivalent to 732 g / m ² , and compression molded under the same method and conditions as in Example 1. A test was conducted. As a result, in the visual observation after standing at room temperature for 24 hours, no warpage or deformation was observed in the box-shaped molded body, and the warp angle α was 0 °, indicating good moldability.

(Comparative Example 1)
A plain woven fabric was produced in the same manner and under the same conditions as in Example 1 except that two linear composite materials C were combined to obtain 3628 dtex. The surface density of the obtained woven fabric was 242 g / m ² . Next, using this woven fabric, a thermocompression bonded fabric sheet was produced under the same method and conditions as in Example 1. The obtained thermocompression bonded fabric sheet had a thickness of 1.1 mm and an area density of 670 g / m ² .

  Next, a compression molding test was performed on the thermocompression bonded fabric sheet produced by the method described above under the same method and conditions as in Example 1. As a result, the obtained box-shaped molded product was warped inward of the side wall surface by visual observation after being allowed to stand at room temperature for 24 hours, and the warp angle α was + 10 °. Moreover, the box-shaped molded object of the comparative example 1 had the bottom part deform | transformed inside centering on the corner part, and its moldability was inferior compared with the Example. The deformation of the bottom part is that the linear composite material C was further stretched at the time of molding because the crystallinity of the fibrous reinforcing material was 52%, which was lower than the range of the present invention, and the strain generated at that time was left at room temperature. It is presumed that this occurred gradually due to the shrinkage of the fiber sheet that was in contact with the male mold, in particular.

(Comparative Example 2)
In addition to the woven fabric, a sheet made of LLDPE resin having a surface density of 200 g / m ² [melt flow rate (MFR) = 8 g / 10 minutes (190 ° C., 21.18 N), melting point = 117 ° C.] was laminated on one side A thermocompression bonded fabric sheet was produced by the same method and conditions as in Comparative Example 1 described above. The obtained thermocompression bonded fabric sheet had a thickness of 1.3 mm and an areal density of 856 g / m ² .

  Next, the thermocompression bonded fabric sheet produced by the above-described method was placed so that the surface on the woven fabric side was in contact with the male side of the mold, and a compression molding test was conducted under the same method and conditions as in Example 1. As a result, in the obtained box-shaped molded body, a very large warpage inward was recognized on the side wall surface in visual observation after standing at room temperature for 24 hours. The warp angle α was + 19 °, and the warp was larger than that of the box-shaped molded body of Comparative Example 1. This is because the linear composite material C has a fiber reinforcing material having a crystallinity of 52%, which is lower than the range of the present invention, and is molded in the vicinity of the melting point of the resin sheet. It is presumed that a shrinkage difference occurred between the sheet and the fibrous reinforcing material (i-PP) in the woven fabric, and the warp increased due to this difference. In addition, the box-shaped molded body of Comparative Example 2 was clearly inferior in moldability as compared with the Examples.

(Comparative Example 3)
A plain woven fabric was produced by the same method and conditions as in Example 1 except that two linear composite materials D were combined to obtain 3640 dtex. The surface density of the obtained woven fabric was 243 g / m ² . Next, using this woven fabric, a thermocompression bonded fabric sheet was produced under the same method and conditions as in Example 1. The obtained thermocompression bonded fabric sheet had a thickness of 1.1 mm and an area density of 670 g / m ² .

  Next, a compression molding test was performed on the thermocompression bonded fabric sheet produced by the method described above under the same method and conditions as in Example 1. As a result, the resulting box-shaped molded article was found to be slightly warped inward on the side wall surface by visual observation after being left at room temperature for 24 hours, and the warp angle α was + 2 °. Moreover, the box-shaped molded body of Comparative Example 3 had a bottom portion warped inward with the corner portion as the center, and was inferior in moldability as compared with the Examples. The cause of the deformation of the bottom part seems to be that the degree of crystallinity of the fibrous reinforcing material of the linear composite material D is 58%, which is lower than the range of the present invention.

(Comparative Example 4)
In addition to the woven fabric, a sheet made of LLDPE resin having a surface density of 200 g / m ² [melt flow rate (MFR) = 8 g / 10 minutes (190 ° C., 21.18 N), melting point = 117 ° C.] was laminated on one side A thermocompression bonded fabric sheet was produced under the same method and conditions as in Comparative Example 3 described above. The obtained thermocompression bonded fabric sheet had a thickness of 1.3 mm and an areal density of 855 g / m ² .

  Next, the thermocompression bonded fabric sheet produced by the above-described method was placed so that the surface on the woven fabric side was in contact with the male side of the mold, and a compression molding test was conducted under the same method and conditions as in Example 1. As a result, the obtained box-shaped molded article was found to have a large warpage inward on the side wall surface in visual observation after being left at room temperature for 24 hours. The warp angle α was + 8 °, and the warp was larger than that of the box-shaped molded body of Comparative Example 3. Moreover, the box-shaped molded body of Comparative Example 4 was clearly inferior in moldability as compared with the Examples.

(Comparative Example 5)
A plain woven fabric was produced by the same method and conditions as in Example 1 except that two linear composite materials E were combined to give 3620 dtex. The surface density of the obtained woven fabric was 241 g / m ² . Next, using this woven fabric, a thermocompression bonded fabric sheet was produced under the same method and conditions as in Example 1. The obtained thermocompression bonded fabric sheet had a thickness of 1.1 mm and an areal density of 669 g / m ² .

  Next, a compression molding test was performed on the thermocompression bonded fabric sheet produced by the method described above under the same method and conditions as in Example 1. As a result, the resulting box-shaped molded product was warped inward on the side wall surface in a small amount in visual observation after standing at room temperature for 24 hours, and the warp angle α was + 4 °. Further, the box-shaped molded body of Comparative Example 5 had a bottom portion warped inward with the corner portion as the center, and the moldability was inferior to that of the example.

(Comparative Example 6)
In addition to the woven fabric, a sheet made of LLDPE resin having a surface density of 200 g / m ² [melt flow rate (MFR) = 8 g / 10 minutes (190 ° C., 21.18 N), melting point = 117 ° C.] was laminated on one side A thermocompression bonded fabric sheet was produced by the same method and conditions as in Comparative Example 5 described above. The obtained thermocompression bonded fabric sheet had a thickness of 1.3 mm and an areal density of 853 g / m ² .

  Next, the thermocompression bonded fabric sheet produced by the above-described method was placed so that the surface on the woven fabric side was in contact with the male side of the mold, and a compression molding test was conducted under the same method and conditions as in Example 1. As a result, the obtained box-shaped molded article was found to have a large warpage inward on the side wall surface in visual observation after being left at room temperature for 24 hours. The warp angle α was + 9 °, and the warp was larger than that in Comparative Example 5. Moreover, the box-shaped molded body of Comparative Example 6 was clearly inferior in moldability as compared with the Examples.

  The above results are summarized in Table 2 and Table 3 below.

  The box-shaped molded body using the thermocompression-bonded fabric sheets of Examples 1 to 11 shown in Table 2 is compared with the box-shaped molded body using the thermocompression-bonded fabric sheets of Comparative Examples 1 to 6 shown in Table 3 above. There was no warpage and the moldability was excellent. From this result, according to the present invention, it was confirmed that a fabric-reinforced resin molded body that hardly warps after molding can be produced.

DESCRIPTION OF SYMBOLS 1, 1a-1d Fibrous reinforcement 2 Coating layer 3 Composite fiber 4 Space | gap 5 Matrix resin 10 Linear composite material 11 Fabric 12 Sheet material 13a, 13b Mold 20 Resin molding

Claims (10)

Heating a fabric formed of a linear composite material obtained by integrating two or more composite fibers by heat stretching, or a sheet material using the fabric;
A step of compressing or vacuum-forming the heated fabric or sheet material using a mold in a cold state, and
The composite fiber is composed of a fibrous reinforcing material and a coating layer made of a thermoplastic resin provided around the fibrous reinforcing material,
In the linear composite material, the fibrous reinforcing material is present in a matrix resin composed of a thermoplastic resin in which the coating layers of the composite fibers are fused and integrated to form the coating layer ,
The said linear composite material is a manufacturing method of the fabric reinforcement | strengthening resin molding whose tensile Young's modulus in 120 degreeC is 7 cN / dtex or more .   The fabric reinforcing resin according to claim 1, wherein the fibrous reinforcing material has a crystallinity of 60% or more measured by a calorimetric method using a differential scanning calorimeter at a heating rate of 30 ° C / min. Manufacturing method of a molded object.   The matrix resin is a polyolefin resin having a melting point of 130 ° C or lower, and the fibrous reinforcing material is formed of a crystalline thermoplastic resin having a melting point of 20 ° C or higher than that of the polyolefin resin. The manufacturing method of the fabric reinforcement | strengthening resin molding of description.   The said linear composite material is a manufacturing method of the fabric reinforcement | strengthening resin molding of any one of Claims 1-3 containing 2 or more types of fibrous reinforcements. The fabric reinforced resin molding according to any one of claims 1 to 4 , wherein, in the heating step, the fabric or the sheet material is set to a temperature equal to or higher than a melting point of the matrix resin and lower than a melting point of the fibrous reinforcing material. Body manufacturing method. The said sheet | seat material is a manufacturing method of the fabric reinforcement | strengthening resin molding of any one of Claims 1-5 which laminates | stacks the said multiple fabrics and thermocompression-bonded at the temperature which the said matrix resin melts. The sheet material is obtained by laminating one or two or more fabrics and a resin sheet made of the same kind of resin as the matrix resin, and thermocompression bonding at a temperature at which the matrix resin melts . 6. The method for producing a fabric reinforced resin molded article according to any one of 5 above. The method for producing a fabric-reinforced resin molded body according to any one of claims 1 to 7 , wherein the fabric is a plain woven fabric. Using the sheet material using the fabric or the fabric formed by heat-stretched two or more composite fibers integrated linear composite,
The composite fiber is composed of a fibrous reinforcing material and a coating layer made of a thermoplastic resin provided around the fibrous reinforcing material,
In the linear composite material, the fibrous reinforcing material is present in a matrix resin composed of a thermoplastic resin in which the coating layers of the composite fibers are fused and integrated to form the coating layer ,
The linear composite material is a fabric-reinforced resin molded body having a tensile Young's modulus at 120 ° C of 7 cN / dtex or more . The fabric reinforcing resin according to claim 9, wherein the fibrous reinforcing material has a crystallinity of 60% or more measured by a calorimetric method using a differential scanning calorimeter at a heating rate of 30 ° C / min. Molded body.

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