JP2014019981A - Method for manufacturing flat yarn and method for manufacturing cloth laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a flat yarn that can stably mass produce a flat yarn having high tensile elasticity and is good in producibility and to provide a method for manufacturing a cloth laminate that has both of high flexural modulus and impact strength using a flat yarn having high tensile elasticity.SOLUTION: A method for manufacturing a flat yarn is that a surface layer including at least random polypropylene is laminated on both surfaces of an intermediate layer comprising homopolypropylene having 500 to 700 thousands of weight average molecular weight to form a belt body, and that the belt body is uniaxially stretched with 12 to 14 times of draw ratio at a high temperature higher than the melting point of homopolypropylene to manufacture the flat yarn. A method for manufacturing a cloth laminate is that the manufactured flat yarn as at least one of a warp yarn and a weft yarn is used to form a cloth-shape body, a plurality of the cloth-shape bodies is laminated at the room temperature and under the atmospheric pressure, is heat pressured, and is cool pressured to manufacture the cloth laminate.

Description

  TECHNICAL FIELD The present invention relates to a method for producing a flat yarn and a method for producing a cross laminate, and more specifically, a method for producing a flat yarn capable of stable mass production and good productivity, and a cross laminate produced using the flat yarn. Regarding the method.

  A flat yarn obtained by uniaxially stretching a strip obtained by cutting a film has a high tensile strength and is used as a yarn material in various fields. In particular, cloth-like bodies formed using flat yarns are frequently used as materials for sheets, bags and the like because they have high mechanical strength.

  In recent years, a self-reinforced polymer composite material called SRP (Self Reinforced Plastics) made of the same material has been developed. This is a fiber reinforced plastic (FRP) in which the resin matrix and the reinforcing material are the same material, and consists of an oriented crystalline polymer as a reinforcing material and a non-oriented polymer as a matrix.

  Such a composite material can be obtained by forming a cloth-like body with a high-strength and high-elasticity film, fiber, flat yarn or the like, laminating a plurality of them, and heat-compressing the resulting cross-laminated body. Is recyclable because it is composed of the same material, has a flexural modulus comparable to that of glass fiber reinforcement, is lightweight, has excellent impact resistance, and has good performance at low temperatures. It has many advantages and is expected to be used in various fields such as building materials and automotive parts.

  Conventionally, as such a flat yarn, Patent Document 1 discloses an ABA type uniaxially stretched flat yarn comprising a polypropylene intermediate layer (B) and a surface layer (A) of the same kind as the material of the intermediate layer (B). Is disclosed. This flat yarn is uniaxially stretched at a stretch ratio higher than 12 times at a temperature lower than the melting point of the intermediate layer (B), and has a tensile elastic modulus of at least 10 GPa.

Japanese translation of PCT publication No. 2004-534681

  However, a flat yarn having high mechanical strength has a problem that stable mass production is difficult. That is, in general, to obtain a flat yarn having a large tensile elastic modulus, the draw ratio is increased. However, as the draw ratio is increased, yarn breakage is more likely to occur, and the possibility of a decrease in productivity increases.

  For this reason, there is a demand for a flat yarn that exhibits a predetermined tensile elastic modulus and enables stable mass production without increasing the draw ratio so much.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a flat yarn that can stably produce a flat yarn having a high tensile elastic modulus and has good productivity.

  Another object of the present invention is to provide a method for producing a cloth laminate having a high bending elastic modulus and impact strength using a flat yarn having a high tensile elastic modulus.

  Other problems of the present invention will become apparent from the following description.

  The above problems are solved by the following inventions.

  1. A strip formed by laminating a surface layer containing at least random polypropylene on both sides of an intermediate layer made of homopolypropylene having a weight average molecular weight of 500,000 to 700,000 is 12 to 12 at a temperature higher than the melting point of the homopolypropylene. A flat yarn manufacturing method, characterized in that a flat yarn is manufactured by uniaxial drawing at a draw ratio of 14 times.

  2. 2. The method for producing a flat yarn according to 1 above, wherein the temperature at which the strip is stretched is in the range of 175 to 195 ° C.

  3. 3. The method for producing a flat yarn according to 1 or 2, wherein when the strip is stretched, the stretching time is adjusted so as not to melt to the vicinity of the center in the thickness direction of the intermediate layer.

  4). The surface layer contains random polypropylene and homopolypropylene, and the blend ratio of random polypropylene and homopolypropylene is a ratio (weight ratio) of 1: 9 to 9: 1. 3. A method for producing a flat yarn according to 3.

  5. A flat yarn manufactured by the flat yarn manufacturing method according to any one of 1 to 4 is used for either one or both of the warp and the weft, and then the cloth is formed at room temperature and normal pressure. A method for producing a cloth laminate, comprising producing a cloth laminate by laminating a plurality of sheets, followed by heat compression, then cooling compression.

  6). 6. The cloth according to 5 above, wherein the temperature during the heat compression is in the range of 130 to 160 ° C., the pressure is in the range of 0.5 to 30 MPa, and the time is in the range of 1 to 20 minutes. A manufacturing method of a layered product.

  7). 5 or 6 above, wherein the temperature during the cooling and compression is in the range of 10 to 40 ° C, the pressure is in the range of 0.5 to 30 MPa, and the time is in the range of 1 to 20 minutes. Method for producing a cross laminate.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the flat yarn with favorable productivity which can produce the flat yarn which has a high tensile elasticity modulus stably can be provided.

  Moreover, according to this invention, the cross laminated body which has a high bending elastic modulus and impact strength can be provided using the flat yarn which has a high tensile elasticity modulus.

The perspective view which shows the cross-section of the flat yarn which concerns on this invention Process chart showing the manufacturing process of cross laminate Cross-sectional view of cloth-like body used for cloth laminate The graph which shows the relationship between the draw ratio and the tensile elasticity modulus of the flat yarn which concerns on this invention The graph which shows the relationship between the draw ratio and the tensile elasticity modulus of the flat yarn outside this invention The graph which shows the relationship between the draw ratio and the tensile elasticity modulus of the flat yarn outside this invention

  Embodiments of the present invention will be described below.

  FIG. 1 is a perspective view showing a cross-sectional structure of a flat yarn according to the present invention.

  The flat yarn 1 is constituted by an intermediate layer 10 and a surface layer 20 laminated on both surfaces of the intermediate layer 10.

  The mid layer 10 is made of homopolypropylene. Homopolypropylene is a homopolymer of propylene that does not contain any component other than propylene as a monomer component.

  The homopropylene has a weight average molecular weight (Mw) of 500,000 to 700,000, preferably 500,000 to 600,000. If it is less than 500,000, there is a problem that the stretch ratio described later must be increased in order to achieve a desired tensile elastic modulus (8 to 9 GPa). Moreover, when it exceeds 700,000, the burden placed on the extruder in the molding process is large, and stable mass production becomes difficult.

  On the other hand, the surface layer 20 includes at least random polypropylene. Random polypropylene is composed of propylene as a monomer component and α-olefin of about several percent by weight (for example, ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, And α-olefins other than propylene such as 1-heptene and 1-octene) are randomly copolymerized.

  The surface layer 20 may be made of random polypropylene alone, or homopolypropylene may be blended with random polypropylene. The ratio (weight ratio) between random polypropylene and homopolypropylene is preferably 1: 9 to 9: 1 in order to achieve the object of the present invention.

  The layer ratio of the thickness of the intermediate layer 10 and the surface layer 20 in the flat yarn 1 is preferably 0.5: 9: 0.5 to 2: 6: 2 in terms of surface layer: intermediate layer: surface layer. When the layer ratio is within this range, the object of the present invention can be achieved more effectively.

  As a method of manufacturing the flat yarn 1 in which the intermediate layer 10 and the surface layer 20 are laminated in this way, a three-layer laminated film in which the surface layer 20 is laminated on both surfaces of the intermediate layer 10 is produced, and this laminated film Can be obtained by slitting to a suitable width to produce a band-like body (tape-like body) and stretching it in a uniaxial direction. It can also be obtained by stretching the laminated film itself in a uniaxial direction before slitting the laminated film and slitting it to a predetermined width after stretching.

  As a method for producing a three-layer laminated film, a film to be the intermediate layer 10 and the surface layer 20 is respectively formed and laminated using a dry laminating method or a heat laminating method. It can be appropriately selected from known methods such as a method of extruding and laminating a film that becomes the surface layer 20 on both surfaces, or a method of extruding as a three-layer film by a multilayer coextrusion method. In terms of ease of molding, cost, and adhesion between the layers, a method of obtaining a three-layer film of the intermediate layer 10 and the surface layer 20 in a single step by a multilayer coextrusion method is preferable.

  In the present invention, the uniaxial stretching treatment is characterized by being performed at a stretching ratio of 12 to 14 times at a temperature higher than the melting point of the homopolypropylene (usually 165 ° C.). It is preferable that the extending | stretching temperature is the range of 175-195 degreeC. This temperature is about 10 ° C. to 40 ° C. higher than the melting point of the homopolypropylene constituting the intermediate layer 10. By performing uniaxial stretching treatment in this temperature range and this magnification range, it is possible to obtain a tensile elastic modulus of 8 GPa to 9 GPa while maintaining a relatively low stretching ratio, and stably produce a flat yarn 1 having high mechanical strength. It becomes possible to do.

  When the temperature and the draw ratio are lower than the above range, or on the contrary, they are all easily broken at the time of drawing, and it becomes difficult to produce stably.

  When the flat yarn 1 is stretched, the uniaxial stretching process is performed at a temperature higher than the melting point of the homopolypropylene constituting the intermediate layer 10, but does not reach the vicinity of the center in the thickness direction of the intermediate layer. It is preferable to adjust the stretching time. This is because problems such as breakage can be avoided.

  As a heating means for the uniaxial stretching treatment, for example, a known heating means such as a hot air circulating oven, a hot roll, a hot plate, infrared irradiation, hot oil, steam and the like can be used.

  The stretching operation can be performed in one stage or in multiple stages of two or more stages, preferably in two stages or less.

  The shape of the flat yarn 1 in the present invention can be arbitrarily set according to the purpose. For example, the fineness is preferably 100 dt to 10,000 dt, more preferably 500 dt to 5000 dt, and the yarn width is preferably 0.00. 5 mm to 10 mm, more preferably 1.0 mm to 8 mm, and the total thickness is preferably 10 μm to 200 μm, more preferably 15 μm to 100 μm.

  Various additives can be added to the flat yarn 1 in the present invention according to the purpose. Specifically, organic phosphorus-based, thioether-based antioxidants; hindered amine-based light stabilizers; benzophenone-based, benzotriazole-based, benzoate-based ultraviolet absorbers; anti-static agents; bisamide-based, wax-based, Dispersants such as organic metal salts; lubricants such as amides and organic metal salts; flame retardants such as bromine-containing organic, phosphoric acid, melamine cyanurate, and antimony trioxide; low density polyethylene, linear low Stretching aids such as density polyethylene; organic pigments; inorganic pigments; inorganic fillers; organic fillers; inorganic antibacterial agents such as metal ions, organic antibacterial agents; nucleating agents such as organic phosphorus, benzoic acid, and sorbitol Is mentioned.

  As shown in FIG. 2, the cloth laminate according to the present invention is formed by weaving the flat yarn to form a cloth-like body (weaving step P1), and then laminating a plurality of the obtained cloth-like bodies (lamination). Step P2), followed by heat compression (heat compression step P3) and further cooling compression (cooling compression step P4).

  In the weaving process P1, the cloth-like body is obtained by weaving the flat yarn 1 using either one or both of the warp and the weft. Preferably, the cloth-like body 2 is composed of the flat yarn 1 and the warp 1A. It is obtained by weaving using both of the weft yarns 1B (see FIG. 3). As the weaving method, a plain weave or twill weave can be generally used.

  From the viewpoint of increasing the mechanical strength, the number of warps 1A and wefts 1B to be driven in the cloth-like body 2 is preferably 5 to 50 yarns / 吋 for the warp yarn 1A and 5 to 50 yarns / 吋 for the weft yarn 1B. In order to minimize the vertical and horizontal physical property difference of the obtained cloth-like body 2, it is preferable to use the same warp yarn 1A and the weft yarn 1B, and make the number of driven in the same range.

The weight per unit area of the cloth-like body 2 is preferably 30 to 500 g / m ² from the viewpoint of increasing the mechanical strength.

  In the laminating process P2, a plurality of cloth-like bodies 2 obtained in this way are prepared and laminated in a normal temperature and normal pressure environment. The number of laminated layers can be arbitrarily set according to the purpose, but in general, it is preferably 2 to 20 from the viewpoint of imparting a certain degree of mechanical strength to the cloth laminate.

  In the heat compression process P3, a laminate of the cloth-like bodies 2 that are laminated in a plurality is compressed. The compression condition is preferably performed in a temperature range in which the intermediate layer 10 is not melted, and can be set to 130 ° C. to 160 ° C., for example. By compressing in this temperature range, the intermediate layer 10 does not melt, but the surface layer 20 has a lower melting point than the intermediate layer 10, so the surface layer 20 melts and firmly bonds between the adjacent cloth-like bodies 2. To do.

  The pressure during compression is preferably 0.5 MPa to 30 MPa, and the compression time is preferably 1 to 20 minutes.

  In the cooling compression process P4, the heat-compressed laminate is compressed under cooling conditions. Here, the cooling is performed at a temperature lower than the temperature condition in the heat compression step P3, and specifically, it is preferably performed at 10 to 40 ° C. By this cooling and compression step P4, the surface layer 20 melted by heating is cured, whereby a cloth laminate in which each cloth-like body 2 is firmly cured can be obtained.

  The pressure during compression is preferably 0.5 MPa to 30 MPa, and the compression time is preferably 1 to 20 minutes.

  The compression means used in the heat compression process P3 and the cooling compression process P4 is not particularly limited, and a known apparatus such as a hydraulic press machine, a roll press machine, and a double belt press machine can be used as appropriate.

  It is preferable that the cloth laminate finally obtained through this cooling and compression step P4 has a thickness of 0.5 mm to 10 mm from the viewpoint of obtaining light weight and high mechanical strength.

<Manufacture of flat yarn A>
As the intermediate layer resin, homopolypropylene having a weight average molecular weight (Mw) of 550,000 and a melting point of 166 ° C. was used. As the resin for both surface layers, a blend resin blended so as to be 70% random polypropylene and 30% homopolypropylene was used.

  By a multilayer coextrusion method, a three-layer film comprising an intermediate layer made of the above homopolypropylene and a surface layer made of a blend resin of the above random polypropylene and homopolypropylene on both surfaces thereof was produced. The layer ratio of the thickness of the surface layer: intermediate layer: surface layer was 1: 8: 1.

  The resulting three-layer film was slit to produce a strip having a width of 4.5 mm. A flat yarn A was produced by uniaxially stretching the belt-like body while changing the stretching temperature and the stretching ratio shown in Table 1. The tensile elastic modulus (GPa) of the produced flat yarn was measured according to JIS L1013. The results are shown in Table 1 and FIG.

<Manufacture of flat yarn B>
The layer ratio of surface layer: intermediate layer: surface layer is 1: 8 by the same polypropylene as flat yarn A, except that the intermediate layer resin is homopolypropylene having a weight average molecular weight (Mw) of 400,000 and a melting point of 165 ° C. A three-layer film having a thickness of 1 was prepared. Similarly, a belt-like body was prepared. The flat body B was manufactured by changing the stretching temperature and the stretching ratio shown in Table 2 and uniaxially stretching. The tensile elasticity modulus (GPa) of the produced flat yarn was measured in the same manner as described above, and the results are shown in Table 2 and FIG.

<Manufacture of flat yarn C>
The layer ratio of surface layer: intermediate layer: surface layer is 1: 8 by using the same polypropylene as flat yarn A, except that the intermediate layer resin is homopolypropylene having a weight average molecular weight (Mw) of 350,000 and a melting point of 165 ° C. A three-layer film having a thickness of 1 was prepared. Similarly, a belt-shaped body was manufactured, and the flat body C was manufactured by changing the stretching temperature and the stretching ratio shown in Table 3 and uniaxially stretching. The tensile elasticity modulus (GPa) of the produced flat yarn was measured similarly, and the result is shown in Table 3 and FIG.

  As shown in FIG. 4, flat yarn A obtained by uniaxially stretching 12 to 14 times at a temperature 10 to 30 ° C. higher than the melting point of homopolypropylene constituting the intermediate layer (product of the present invention). Has a tensile modulus of 8 GPa to 9 GPa.

  In addition, under the stretching conditions exceeding 14 times or under the conditions where the temperature range deviates from the scope of the present invention even under the stretching ratios of 12 times to 13 times, yarn breakage occurred during the stretching treatment, and a flat yarn could not be produced.

  On the other hand, as shown in FIGS. 5 and 6, when the weight average molecular weight (Mw) of the homopolypropylene constituting the intermediate layer is less than 500,000, it was possible to produce a flat yarn, but overall tensile elasticity The rate is low. For example, in order to obtain a tensile elastic modulus of 8 GPa, in the present invention, a draw ratio of 12 times is sufficient as shown in FIG. 4, but in flat yarn B shown in FIG. The flat yarn C shown in FIG. 6 must be stretched 15 times or more at 150 ° C. and 16 times or more at 160 ° C. Must be processed.

  That is, in the flat yarns B and C, when the flat yarn having the same tensile elastic modulus as in the present invention is used, the draw ratio must be increased. If a flat yarn is to be produced at a large draw ratio, the productivity is lowered.

  That is, according to the present invention, it is understood that a flat yarn having a tensile elastic modulus of 8 GPa to 9 GPa can be stably mass-produced and the productivity is excellent.

<Manufacture of cross laminate>
A cloth-like body was woven by plain weaving using the flat yarn A having a draw ratio of 13 times produced as described above as warp and weft. The number of driven-in yarns was 15 warps / 吋, 15 wefts / 吋, and the basis weight was 200 g / m ² .

  Eight of these cloth-like bodies were laminated, laminated in a normal temperature and normal pressure environment, and then compressed using a hydraulic press. The heating and compression conditions were a temperature of 150 ° C., a pressure of 15 MPa, and a compression time of 3 minutes. The cooling compression conditions were a temperature of 35 ° C., a pressure of 15 MPa, and a compression time of 2 minutes. Table 4 shows the physical properties of the cloth laminate obtained in this manner.

A general polypropylene injection-molded product has a flexural modulus of about 1000 to 2000 MPa, a Charpy impact strength of about 5 to ²⁰ kJ / m ² , is flexible but weak, and a general short glass fiber is used. The contained FRP molded product has a flexural modulus of about 5000 MPa and a Charpy impact strength of about ²⁰ kJ / m ² , and is hard but brittle. On the other hand, it can be seen that the cloth laminate according to the present invention exhibits excellent properties having both high flexural modulus and Charpy impact strength.

1: Flat yarn 1A: Warp 1B: Weft 10: Intermediate layer 20: Surface layer

Claims (7)

  A strip formed by laminating a surface layer containing at least random polypropylene on both sides of an intermediate layer made of homopolypropylene having a weight average molecular weight of 500,000 to 700,000 is 12 to 12 at a temperature higher than the melting point of the homopolypropylene. A flat yarn manufacturing method, characterized in that a flat yarn is manufactured by uniaxial drawing at a draw ratio of 14 times.   The method for producing a flat yarn according to claim 1, wherein the temperature at which the strip is stretched is in the range of 175 to 195 ° C.   The method for producing a flat yarn according to claim 1 or 2, wherein when the strip is stretched, the stretching time is adjusted so as not to melt to the vicinity of the center in the thickness direction of the intermediate layer. .   The surface layer contains random polypropylene and homopolypropylene, and the blend ratio of random polypropylene and homopolypropylene is a ratio (weight ratio) of 1: 9 to 9: 1. Or the manufacturing method of the flat yarn of 3.   A flat yarn produced by the flat yarn production method according to any one of claims 1 to 4 is used for either one or both of warp and weft, and then the fabric is treated at normal temperature. A method for producing a cloth laminate, comprising: laminating a plurality of sheets under pressure, followed by heat compression, and then cooling compression to produce a cloth laminate.   The temperature during the heat compression is in the range of 130 to 160 ° C, the pressure is in the range of 0.5 to 30 MPa, and the time is in the range of 1 to 20 minutes. A method for producing a cloth laminate. The temperature during the cooling and compression is in the range of 10 to 40 ° C, the pressure is in the range of 0.5 to 30 MPa, and the time is in the range of 1 to 20 minutes. The manufacturing method of the cross laminated body of description.

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