JP2007143945A - Primary ground fabric for tufted carpet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a primary ground fabric for a tufted carpet, which is biodegradable, is hardly deformed and reduced in strength under a high-temperature atmosphere, and is excellently thermostable with respect to heat which is given in a carpet manufacturing process. <P>SOLUTION: Composite filaments including an aromatic polyester-based polymer and a polylactic acid-based polymer is adopted as configuration filaments. A repeating unit, which includes terephthalic acid and aliphatic dicarboxylic acid as an acid component; and ethyleneglycol and diethylene glycol as a glycol component, is adopted as a configuration component in the aromatic polyester-based polymer where the melting point is higher than that of the polylactic acid-based polymer. The melting point of the latter polymer is not less than 150°C. The composite form of the composite filaments is obtained by forming a core part with the polylactic acid-based polymer and forming a sheath part with the aromatic polyester-based polymer. Consequently, the primary ground fabric for the tufted carpet includes a composite filament nonwoven fabric with the composite filaments integrated therein, to which a binder resin adheres. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a primary base fabric for tufted carpet.

  In recent years, synthetic fibers using petroleum as a raw material have a large amount of heat generated during incineration, and therefore need to be reviewed from the viewpoint of protecting the natural environment. In contrast, fibers made of aliphatic polyester that biodegrades in nature have been developed and are expected to contribute to environmental protection. Among aliphatic polyesters, a polylactic acid polymer that is a plant-derived polymer and does not use petroleum as a raw material has a relatively high melting point, and is expected to be used in a wide range of fields. In addition, polylactic acid polymers have the best mechanical properties and cost balance among biodegradable polymers. And development of the fiber using this is performed at a rapid pitch.

  However, even the most promising polylactic acid-based polymers have a problem of poor high-temperature mechanical properties. Here, poor high temperature mechanical properties indicate that the polymer rapidly softens when the glass transition temperature (Tg) of the polylactic acid polymer exceeds 60 ° C. Actually, when a tensile test of a long-fiber non-woven fabric made of a polylactic acid polymer is performed by changing the atmospheric temperature, it has been found that the strength of the long-fiber non-woven fabric rapidly decreases at 70 ° C. or higher. Accordingly, a long fiber nonwoven fabric made of a polylactic acid-based polymer is inferior in mechanical properties at high temperatures, and therefore there is no problem when used in a normal atmosphere, but deformation or sag occurs in a high temperature atmosphere.

  On the other hand, it is known to use a nonwoven fabric in which long fiber groups are accumulated as a primary base fabric of tufted carpet. This primary base fabric is used as a support when tufting (implanting pile yarn) pile yarn. In the carpet manufacturing process, tufting is performed using desired pile yarn on the primary base fabric. A carpet is obtained by obtaining a raw machine and performing a backing process, and the obtained carpet is subjected to desired molding as necessary.

  In the backing treatment process, usually the hot melted backing material is laminated or coated and then dried in an oven to harden the backing material. The primary base fabric is contacted with the hot melted backing material. Heat is applied, and heat is also applied in the subsequent drying process. Therefore, the primary base fabric is required to have thermal stability that can withstand the heat in the backing process, that is, is not easily deformed by heating.

  Further, when molding is performed on the obtained carpet, heat is applied to the carpet, and a predetermined mold (a mold composed of a male mold and a female mold) is used and pressed to form a molded carpet. In this molding process, heating is performed at a temperature of about 130 to 140 ° C., so that the primary base fabric used for the molded carpet retains strength and stress for stretching even at high temperatures and has an appropriate elongation. Desired. In particular, when deep drawing is performed, the primary base fabric that is the support of the pile is required to follow along the molding die well, and if the follow cannot be followed, the entire base fabric does not deform uniformly. Only the molded part is excessively stretched, the base fabric in the molded part becomes thin, and a tufted carpet with a uniform thickness cannot be obtained. In severe cases, it is torn during the molding process.

  As described above, the long fiber nonwoven fabric made of a polylactic acid-based polymer is inferior in mechanical properties at high temperatures, and therefore, when applied to a primary carpet for carpet, the long-fiber nonwoven fabric is resistant to heat, self-weight, and stress applied in the backing process. There is a problem that it cannot be withstood and deformed, or that it cannot withstand the heat and stress applied during thermoforming and cannot be molded well.

The present applicant has proposed a non-woven fabric obtained by laminating a long-fiber web made of a polylactic acid polymer and a long-fiber web made of an aromatic polyester as a long-fiber non-woven fabric having good thermoformability (Patent Document 1). .
Japanese Patent Application No. 2004-238958

  An object of the present invention is a long-fiber nonwoven fabric having a polylactic acid-based polymer as a constituent polymer, is biodegradable and hardly deforms or loses strength in a high-temperature atmosphere, and is imparted in the carpet manufacturing process. An object of the present invention is to provide a primary base fabric for tufted carpet that is excellent in heat stability and heat resistance against the heat generated.

  As a result of intensive studies to apply a long-fiber nonwoven fabric having a polylactic acid-based polymer as a constituent polymer to a primary base fabric for carpet, the present inventors have found that a polylactic acid-based polymer having a melting point of 150 ° C. or higher and an acid A composite long fiber using terephthalic acid and aliphatic dicarboxylic acid as components, and an aromatic polyester copolymer comprising repeating units containing ethylene glycol and diethylene glycol as glycol components, and compounding them in a specific form The present invention has been found out that even when a non-woven fabric having a polylactic acid-based polymer as a constituent polymer is used, it is possible to impart heat resistance that is unlikely to cause deformation or strength reduction in a high-temperature atmosphere. did.

  That is, the present invention uses a composite continuous fiber containing an aromatic polyester copolymer and a polylactic acid polymer as a constituent fiber, and the aromatic polyester copolymer has terephthalic acid, aliphatic dicarboxylic acid, and glycol components as acid components. As a constituent, a repeating unit containing ethylene glycol and diethylene glycol is used as a constituent component, and the melting point is higher than that of the polylactic acid polymer. The melting point of the polylactic acid polymer is 150 ° C. or higher. The lactic acid-based polymer forms a core and the aromatic polyester copolymer is a core-sheath type composite continuous fiber that forms a sheath, or the polylactic acid-based polymer forms a core, and the aromatic polyester A multi-leaf type composite continuous fiber in which a plurality of protruding leaf parts are formed so that the copolymer surrounds the outer periphery of the core part, and the composite long fiber unwoven cloth in which the composite long fibers are accumulated Rannahli, and in which it is summarized as the primary backing for tufted carpets, characterized in that the binder resin is adhered.

  Hereinafter, the present invention will be described in detail.

  The primary base fabric for tufted carpet according to the present invention is composed of a composite long-fiber nonwoven fabric comprising composite long fibers containing an aromatic polyester copolymer and a polylactic acid-based polymer as constituent fibers.

  The aromatic polyester copolymer used in the present invention has a higher melting point than the polylactic acid polymer described later, and includes repeating units containing terephthalic acid and aliphatic dicarboxylic acid as acid components, and ethylene glycol and diethylene glycol as glycol components. Is produced by a conventionally known polycondensation method. In addition, the aromatic polyester copolymer may contain a sulfonic acid metal salt as an acid component, if necessary.

  The terephthalic acid in the acid component is preferably from 50 mol% to 95 mol%, more preferably from 52 mol% to 92 mol%, based on the total acid component as 100 mol%. The greater the amount of terephthalic acid, the higher the mechanical strength.

  The content of the aliphatic dicarboxylic acid in the acid component contributes to the biodegradability of the resulting nonwoven fabric. That is, the aliphatic dicarboxylic acid is preferably 5 mol% to 50 mol%, more preferably 10 mol% to 45 mol%, based on 100 mol% of the entire acid component. If it is less than 5 mol%, the glass transition temperature cannot be significantly lowered, and the biodegradability of the nonwoven fabric is poor. On the other hand, when it exceeds 50 mol%, the glass transition temperature is lowered, and troubles such as insufficient cooling of the spun yarn and poor opening of the spun yarn occur in the nonwoven fabric production process, and the desired heat resistance is difficult to obtain.

  The aliphatic dicarboxylic acid is an aliphatic dicarboxylic acid having 2 to 18 carbon atoms, preferably 2 to 10 carbon atoms, and specific examples thereof include azelanic acid, succinic acid, adipic acid, sebacic acid, and glutaric acid. Of these, glutaric acid is preferably used.

  The sulfonic acid metal salt can be used as necessary in order to develop biodegradability more strongly. Specific examples include a metal salt of 5-sulfoisophthalic acid, a metal salt of 4-sulfoisophthalic acid, and a metal salt of 4-sulfophthalic acid. As the metal ions, alkali metals such as sodium, potassium and lithium and alkaline earth metals such as magnesium are preferable.

  When the sulfonic acid metal salt is used, the total acid component is 100 mol%, terephthalic acid is 50 mol% to 90 mol%, aliphatic dicarboxylic acid is 4 mol% to 49.8 mol%, and the sulfonic acid metal salt is It is preferable that it is 0.2 mol%-6 mol%, and what is necessary is just to adjust the usage-amount of a sulfonic acid metal salt according to the degree of biodegradability which should be expressed as mentioned above.

  On the other hand, with respect to the glycol component constituting the aromatic copolymer polyester, the total glycol component is 100 mol%, and the ethylene glycol in the glycol component is preferably 50 mol% to 99.9 mol%, corresponding to this. Diethylene glycol is preferably 0.1 mol% to 50 mol%. If the diethylene glycol unit exceeds 50 mol%, the mechanical properties of the fiber, that is, the nonwoven fabric, tend to be inferior. Conversely, if it is less than 0.1 mol%, the desired biodegradability cannot be obtained.

  As the aromatic polyester copolymer, one having a melting point higher than that of the polylactic acid polymer is used. The aromatic polyester copolymer has a composition as described above, and can have a higher melting point than the polylactic acid polymer due to the copolymerization ratio. For example, the polylactic acid polymer has a melting point of about 180 ° C. at the maximum as described later, but the aromatic polyester copolymer can have a melting point of about 200 ° C. or higher. For example, DuPont's “Biomax (registered trademark) 4027” has a melting point of 235 ° C., and its “Biomax (registered trademark) 4026” has a melting point of 200 ° C.

  Since the aromatic polyester copolymer used in the present invention has such a composition, it is easily decomposed under composting conditions.

  The polylactic acid-based polymer used in the present invention includes poly-D-lactic acid, poly-L-lactic acid, a copolymer of D-lactic acid and L-lactic acid, and D-lactic acid and hydroxycarboxylic acid. A polymer selected from the group consisting of a copolymer, a copolymer of a copolymer of L-lactic acid and hydroxycarboxylic acid, and a copolymer of D-lactic acid, L-lactic acid and hydroxycarboxylic acid, or These blends are mentioned. Examples of the hydroxycarboxylic acid for copolymerizing the hydroxycarboxylic acid include glycolic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxypentanoic acid, hydroxycaproic acid, hydroxyheptanoic acid, hydroxyoctanoic acid, and the like. In particular, hydroxycaproic acid and glycolic acid are preferable from the viewpoint of decomposition performance and low cost.

  In the present invention, the above polylactic acid polymer having a melting point of 150 ° C. or higher or a blend thereof is used. When the melting point of the polylactic acid-based polymer is 150 ° C. or higher, it has high crystallinity. Therefore, shrinkage hardly occurs due to heat applied in the carpet manufacturing process, and heat treatment processing should be performed stably. It has excellent heat resistance.

  The melting point of poly-L-lactic acid and poly-D-lactic acid, which are homopolymers of polylactic acid, is about 180 ° C. When not a homopolymer but a copolymer is used as the polylactic acid polymer, the copolymerization ratio of the monomer components is determined so that the melting point of the copolymer is 150 ° C. or higher. In the case of a copolymer of L-lactic acid and D-lactic acid, the copolymerization ratio of L-lactic acid and D-lactic acid is a molar ratio of (L-lactic acid) / (D-lactic acid) = 5/95. ˜0 / 100 or (L-lactic acid) / (D-lactic acid) = 95/5 to 100/0. If the copolymerization ratio is out of the above range, the melting point of the copolymer becomes less than 150 ° C., the amorphousness becomes high, and the object of the present invention cannot be achieved.

  As long as the object of the present invention is achieved, the polymer constituting the composite long-fiber nonwoven fabric described above includes pigments, heat stabilizers, antioxidants, weathering agents, flame retardants, end-capping agents, plasticizers, lubricants, Release agents, antistatic agents, fillers, and the like may be added. For example, it is preferable to blend talc as a crystal nucleating agent.

  The composite form of the composite long fiber constituting the long fiber nonwoven fabric of the present invention is a core-sheath type in which the polylactic acid-based polymer forms the core and the aromatic polyester copolymer forms the sheath, or The polylactic acid-based polymer forms a core part, and the aromatic polyester copolymer is a multi-leaf type in which a plurality of protruding leaf parts are formed so as to surround the outer periphery of the core part.

  By placing the polylactic acid polymer in the core and covering the core with a sheath of the aromatic polyester copolymer, or surrounding the core with a plurality of protruding leaves of the aromatic polyester copolymer That is, by arranging the polylactic acid polymer in the center of the cross section of the fiber, it is possible to make the polylactic acid polymer difficult to transmit heat from the outside, under the high temperature of the polylactic acid polymer. The disadvantage of poor mechanical properties can be covered.

  1 and 2 are schematic views showing examples of cross sections of a multileaf type composite fiber in the present invention. 1 and 2 are multi-leaf type composite fibers 3 in which a polylactic acid-based polymer forms a core part 1 and an aromatic polyester copolymer forms a leaf part 2. In FIG. 1, each leaf part 2 is divided by the core part 1, and a part of the polylactic acid polymer of the core part 1 is exposed on the fiber surface. In FIG. 2, the leaf portion 2 is not divided by the core portion 1 but is formed in a series of rings and covers the core portion 1. With such a configuration, since the leaf part 2 protrudes in a protruding shape, the degree of atypicality becomes high, so that in the fiber production process, the melt-spun fiber is easy to cool and the opening property is improved. Play.

  The number of leaf parts in the multileaf composite type is preferably 3 to 10. When the number of protruding leaf parts is small, depending on the size of each leaf part, the polylactic acid polymer that is the core part is easily exposed on the surface of the fiber, and when the exposed ratio increases, heat from the outside is increased. Tends to be transmitted to the polylactic acid polymer, and the object of the present invention tends to be hardly achieved. In addition, when the number of leaf parts increases, the leaf parts come into contact with each other, so that a so-called core-sheath cross-sectional shape that completely covers the core part tends to be formed, and the degree of variation tends to be small. Moreover, it is preferable that the arrangement | sequence form of a protrusion-shaped leaf part is located at equal intervals on the outer periphery of a fiber cross section, respectively. If the leaf portions are offset from each other on the outer periphery of the fiber cross section, the spun yarn causes kneeling in the spinning process, which is not preferable.

  The composite ratio (mass ratio) of the polylactic acid polymer and the aromatic polyester copolymer in the composite long fiber is polylactic acid polymer / aromatic polyester copolymer = 3/1 to 1/3. preferable. When the ratio of the core exceeds 3/1, the ratio of polylactic acid polymer in the whole fiber increases, and the mechanical properties of the nonwoven fabric in a high temperature atmosphere tend to be inferior, so heat is applied in the carpet manufacturing process. Deformation and sag occur at the time of being formed, and partial tearing tends to occur during thermoforming. On the other hand, when the ratio of the core portion is less than 1/3, the mechanical properties under a high temperature atmosphere are excellent, but the ratio of the polylactic acid polymer that is a plant-derived polymer is decreased.

  The single yarn fineness of the composite continuous fiber in the present invention is about 0.5 decitex to 11 decitex in consideration of spinnability when the composite long fiber is spun, practical strength as a primary base fabric for tufted carpet, and the like. It is preferable.

  The primary base fabric for tufted carpet of the present invention is composed of a composite long fiber nonwoven fabric in which composite long fibers containing a polylactic acid polymer and an aromatic polyester copolymer are accumulated. The non-woven fabric may be simply a collection of composite long fibers, but the constituent fibers are preferably entangled three-dimensionally, and can be entangled three-dimensionally with a needle punch. Those in which the constituent fibers are entangled three-dimensionally have the advantage that delamination is unlikely to occur because the fibers are entangled not only in the two-dimensional direction, that is, the surface direction of the nonwoven fabric, but also in the thickness direction of the nonwoven fabric. According to the needle punch, the constituent fibers are strongly pushed in with a highly rigid punch needle, so that the fibers move so that the longitudinal direction of the fibers is along the thickness direction. Since they are entangled, the constituent fibers in the thickness direction can be well integrated. Therefore, the primary base fabric in which the constituent fibers are three-dimensionally entangled by the needle punch does not cause delamination when tufting the tuft yarn, and has good shape retention.

  The binder resin adheres to the composite long fiber nonwoven fabric in the present invention. By adhering the binder resin, the contact points of the constituent fibers are adhered by the binder resin, so that the obtained primary base fabric for tufted carpet is improved in stress and tensile strength when stretched.

  It is preferable that the adhesion amount (solid content adhesion amount) of binder resin is 5-20 mass% with respect to the total mass of a primary base fabric. By setting the adhesion amount of the binder resin within the above range, it is possible to increase the tensile strength of the primary base fabric and the stress at the time of extension (intermediate load) in a high temperature atmosphere. By increasing the tensile strength and intermediate load, it is difficult for thermal deformation to occur when heat is applied in the carpet manufacturing process, and the primary base fabric follows the deep-drawing mold during thermoforming and moldability. Becomes better. When the adhesion amount of the binder resin is less than 5% by mass, the effect of imparting the binder resin cannot be exhibited. On the other hand, when the adhesion amount exceeds 20% by mass, the amount of the binder resin existing between the long fibers is large. As a result, the degree of freedom of the fiber is lost, so that when the pile yarn is tufted on the primary base fabric, the fiber is greatly damaged by the tuft needle, and the strength of the primary base fabric is reduced.

  As the binder resin used in the present invention, the same resin as the polylactic acid polymer constituting the nonwoven fabric described above can be suitably used. Polysaccharides such as polyvinyl alcohol and natural starch such as starch, protein, chitosan and the like may also be used. In addition, a desired molar ratio can be obtained by combining two or more conventionally used monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, acrylonitrile, and styrene. Copolymers copolymerized with can also be employed. Moreover, you may use the bridge | crosslinking type binder resin which bridge | crosslinked these copolymers with crosslinking agents, such as a melamine resin and a phenol resin.

  The primary base fabric for tufted carpet of the present invention has a tensile strength at 130 ° C. of 50 N / 5 cm width or more in both the vertical and horizontal directions, and an elongation at break of 50% or more in both the vertical and horizontal directions. It is preferable that the tensile strength at 130 ° C. is 70 N / 5 cm width or more. By having the above characteristics, it can be expected that the thermoforming is performed satisfactorily. The upper limit of the tensile strength at 130 ° C. and the elongation at break should be about 300 N / 5 cm width and the elongation is about 150% in consideration of the limit value depending on the combination of the polymers used in the present invention. .

  Further, in thermoforming, it is preferable to have an appropriate stress at the initial elongation, and the stress (intermediate load) at 10% elongation at 130 ° C. is 10 N / 5 cm width or more in both the vertical direction and the horizontal direction. It is preferable that the width is 20 N / 5 cm or more. When the width is less than 10 N / 5 cm, it does not extend evenly, but locally extends in a deep drawing portion or the like, and a thin portion tends to occur. On the other hand, the upper limit of the stress is not particularly limited, but may be about 60 N / 5 cm width. Furthermore, it is preferable to have an appropriate stress at the time of initial elongation because thermal deformation in the backing process is less likely to occur.

  In the present invention, the tensile strength at 130 ° C., the elongation at break, and the stress at extension are measured in a high temperature atmosphere at 130 ° C. according to JIS-L-1906. That is, 10 pieces of strip-shaped test pieces having a width of 5 cm and a length of 20 cm were prepared for the vertical direction (MD) and the horizontal direction (CD) of the nonwoven fabric, and a constant-speed extension type tensile tester (at a high temperature atmosphere of 130 ° C.) Using Tensilon UTM-4-1-100 manufactured by Orientec Co., Ltd., hold a sample piece at a spacing of 10 cm, leave it for 5 minutes, and then stretch at a tensile rate of 10 cm / min to create an extension-load curve. . The average value of 10 points for the maximum load value (N / 5 cm width) obtained from the obtained elongation-load curve is taken as the tensile strength (N / 5 cm width) in a high temperature atmosphere, and the elongation at break is 10 The average value of the points is defined as the elongation (%) at break in a high-temperature atmosphere, and the average value of 10 points of the load value at each elongation is defined as the stress (N / 5 cm width) during expansion.

The primary base fabric for tufted carpet of the present invention preferably has a basis weight in the range of 50 to 300 g / m ² , more preferably 70 to 200 g / m ² . When the basis weight is less than 50 g / m ² , the mechanical strength is inferior, so it is not practical. On the other hand, when the basis weight exceeds 300 g / m ² , it is disadvantageous in terms of cost.

  In the present invention, a tufted carpet is obtained by tufting the above-mentioned primary base fabric for tufted carpet using a desired pile yarn. In addition, in the raw machine obtained by tufting pile yarn, for the purpose of fixing pile yarn and for maintaining the shape of tufted carpet, laminating molten polyethylene etc. from a T-die and laminating, drying And backing material can be applied. In addition, when the tufted carpet of the present invention is thermoformed, it may be thermoformed by a known method, and heat of 130 to 140 ° C. is applied to the carpet, and then a predetermined mold (male mold and female mold) is applied. And press-molding using a mold comprising the following.

  Next, the preferable manufacturing method of the primary base fabric for tufted carpets of this invention is demonstrated.

  The polylactic acid-based long fiber nonwoven fabric used in the present invention can be efficiently produced by a spunbond method.

  First, a polylactic acid polymer and the above-described aromatic polyester copolymer are prepared. Weighing each prepared polymer individually, melt spinning through a core-sheath type composite spinneret in which a polylactic acid-based polymer forms a core and an aromatic polyester copolymer forms a sheath, The spun yarn is cooled by using a conventionally known cooling device such as horizontal spraying or annular spraying, and then pulled and thinned using a suction device. Alternatively, the polylactic acid-based polymer forms a core portion, and the aromatic polyester copolymer melt-spins through a multi-leaf type composite spinneret that constitutes a leaf portion, and is similarly processed.

  The traction speed at this time is preferably set to 3500-5500 m / min. When the pulling speed is less than 3500 m / min, the molecular orientation is not sufficiently promoted in the yarn, and the resulting long fiber nonwoven fabric tends to be inferior in dimensional stability and thermal stability. On the other hand, if the pulling speed is too high, the spinning stability is poor.

  The stretched long fibers are spread with a known spreader and then spread on a movable collection surface such as a screen conveyor to form a nonwoven web in which the constituent fibers are randomly deposited. .

  Next, the obtained nonwoven web is subjected to needle punching, and the constituent fibers are entangled three-dimensionally. In addition, before performing a needle punch process, you may give low temperature heat and pressure to a nonwoven web with a roll etc. in consideration of the conveyance property of a nonwoven web. The surface temperature of the roll at this time is such that the fibers can be removed from the web and the web form can be maintained, and the fibers are not fused together, and the fused portion can be easily removed by needle punching. Try to be in the fiber state. Specifically, it is preferable to set the temperature lower by 110 to 150 ° C. than the melting point of the aromatic polyester copolymer.

The needle density in the needle punching process is preferably 20 to 100 times / cm ² . When the needle density is less than 20 times / cm ² , the degree of entanglement between the long fibers is low, and the effect of applying needle punch cannot be exhibited. On the other hand, when the needle density exceeds 100 times / cm ² , the long fibers are severely damaged, and the fibers themselves become extremely low in strength, so that the mechanical strength of the nonwoven fabric tends to be inferior.

  Next, a desired amount of binder resin is adhered to the nonwoven fabric in which the constituent fibers are entangled to obtain the primary base fabric for tufted carpet of the present invention. As a method for attaching the binder resin, a known method may be adopted, for example, impregnation with a binder resin liquid emulsified and dispersed in water, or applying a binder resin liquid by a technique such as spraying or coating, followed by a drying heat treatment. The method of doing is mentioned.

  The composite long fiber nonwoven fabric constituting the primary base fabric for tufted carpet of the present invention is a polylactic acid polymer that is biodegradable but inferior in mechanical properties at high temperatures, and has excellent mechanical properties at high temperatures as an acid component. By adopting a fiber which is a composite form of a form generally covered with an aromatic polyester copolymer comprising a repeating unit containing terephthalic acid and an aliphatic dicarboxylic acid and ethylene glycol as a glycol component, The lactic acid polymer can be made into a form in which it is difficult for heat from the outside to be transmitted, and deformation and sag are less likely to occur even in a high-temperature atmosphere, and heat and the self-weight due to backing are added during the backing process in the carpet manufacturing process. Even if it is, thermal deformation is unlikely to occur.

  In addition, the primary base fabric for tufted carpet of the present invention exhibits good heat resistance as described above, and therefore has the strength and elongation required at the time of thermoforming, and the stress at the time of stretching, and is thermoformed. At the same time, it exhibits sufficient elongation, and it can be expected that it is less likely to cause molding failure such as molding breakage and melee while following the mold, and it can also be applied to molded carpets for automobiles and the like.

Next, the present invention will be specifically described based on examples, but the present invention is not limited to only these examples. In addition, the various physical-property values in a following example and a comparative example were measured with the following method.
(1) Melt flow rate (g / 10 min): Measured at a temperature of 210 ° C. and a load of 2160 gf according to the method described in ASTM-D-1238 (E). Hereinafter, the melt flow rate is referred to as “MFR”.
(2) Relative viscosity (ηrel): 0.5 g of a sample was dissolved in 100 cc of a mixed solvent having an equal mass ratio of phenol and ethane tetrachloride and measured using an Ostwald viscometer.
(3) Melting point (° C.): Using a differential scanning calorimeter (Perkin Elma, DSC-2 type), measuring the sample mass at 5 mg and the heating rate at 10 ° C./min. The temperature giving the maximum value of was the melting point (° C.).
(4) Fineness (Decitex: hereinafter referred to as “dtex”): The fiber diameter of 50 fibers from the nonwoven web was measured with an optical microscope, and the average value obtained by correcting the density was defined as the fineness.
(5) Weight per unit area (g / m ² ): Ten sample pieces each having a sample length of 10 cm and a sample width of 5 cm were prepared from a sample in a standard state, and the mass (g) of each sample piece was weighed. The average value was converted per unit area to obtain a basis weight (g / m ² ).
(6) Tensile strength at normal temperature (N / 5 cm width), elongation (%): Ten strip-shaped test pieces having a width of 5 cm and a length of 20 cm were prepared, and a constant-speed extension type tensile tester (manufactured by Orientec) Tensillon UTM-4-1-100) was used to conduct a tensile test at a grip interval of 10 cm and a tensile speed of 20 cm / min, and measured according to JIS-L-1906 to draw an extension-load curve. The average value of 10 points for the maximum load value (N / 5 cm width) obtained from the obtained elongation-load curve is the tensile strength (N / 5 cm width), and the average value of 10 points for the elongation at break is The elongation at break (%) was taken, and the average value of 10 load values at each elongation was taken as the stress (N / 5 cm width) during expansion. In addition, the temperature at the time of measurement was 25 degreeC.

Example 1
An L-lactic acid / D-lactic acid copolymer having a melting point of 168 ° C. and an MFR of 20 g / 10 min and L-lactic acid / D-lactic acid = 98.6 / 1.4 mol% was prepared as a polylactic acid polymer. On the other hand, the aromatic polyester copolymer has a melting point of 235 ° C., a relative viscosity ηrel = 1.42, an aromatic polyester having a repeating unit comprising terephthalic acid and glutaric acid as acid components and ethylene glycol and diethylene glycol as glycol components. A copolymer (manufactured by DuPont, Biomax (R) 4027, not including a sulfonic acid metal salt) was prepared.

  The polylactic acid polymer is the core, the aromatic polyester copolymer is the sheath, and the core / sheath portion is 1/1 (mass ratio). After individually weighing so as to be 0.5% by mass in the lactic acid-based polymer, each polymer was melted at a temperature of 245 ° C. using an individual extruder type melt extruder, Melt spinning was carried out at 38 g / min.

  After cooling the spun yarn with a known cooling device, it is subsequently pulverized at a traction speed of 3900 m / min with an air soccer provided below the spinneret, and opened using a known fiber opening device, It was collected and deposited as a composite long fiber web on a moving screen conveyor. The single yarn fineness of the deposited composite long fiber was 3.5 dtex.

The obtained web was passed through a partial thermocompression bonding apparatus composed of an embossing roll and a smooth metal roll, and the roll temperature was 95 ° C., the crimping area ratio was 14.9%, the crimping point density was 21.9 pieces / cm ² , and the linear pressure was 196 N. A web subjected to thermocompression bonding with a basis weight of 130 g / m ² was obtained.

1 part by mass of a silicone-based oil agent is attached to the web with respect to 100 parts by mass of the fiber of the web, subjected to needle punching, and the constituent fibers are entangled three-dimensionally to form a nonwoven fabric having a basis weight of 131 g / m ² . Obtained. The needle punching conditions were a needle depth of 12 mm and a punch density of 45 times / cm ² using a # 40 regular barb punch needle. Next, prepare a binder resin solution obtained by diluting an acrylic binder resin solution (trade name “Acrodure 945L” manufactured by BASF) with water, and impregnate the binder resin solution into a nonwoven fabric in which the constituent fibers are entangled three-dimensionally. Thus, a primary base fabric for tufted carpet having a basis weight of 152 g / m ² was obtained by drying and heat treatment. Therefore, the adhesion amount (solid content) of the binder resin is 14% by mass.

Example 2
In Example 1, a primary base fabric for tufted carpet was obtained in the same manner as in Example 1 except that polyvinyl alcohol was used instead of the acrylic binder resin liquid as the binder resin.

Example 3
Example 1 Example 1 except that the basis weight of the nonwoven fabric obtained by three-dimensional entanglement was 100 g / m ² , and polyvinyl alcohol was used as the binder resin instead of the acrylic binder resin liquid. In the same manner as described above, a primary base fabric for a tufted carpet having a basis weight of 116 g / m ² was obtained. The adhesion amount of the obtained binder resin is 14% by mass (solid content).

Example 4
In Example 1, instead of the core-sheath type composite cross section, the cross-sectional shape of the composite long fiber is a polylactic acid polymer disposed in the core portion, and the core portion has six protruding leaves of an aromatic polyester copolymer. Example 1 except that it was spun from the spinneret so as to have a six-leaf type composite cross section as shown in FIG. 1 surrounded by the part, and that polyvinyl alcohol was used as the binder resin instead of the acrylic binder resin liquid. In the same manner as above, a primary base fabric for tufted carpet was obtained.

Comparative Example 1
A non-woven fabric was produced using a polylactic acid polymer. That is, L-lactic acid / D-lactic acid = 98.6 / 1.4 mol% L-lactic acid / D-lactic acid copolymer having a melting point of 168 ° C. and an MFR of 65 g / 10 min has talc as an additive. Blended in a molten polylactic acid polymer to 0.5% by mass, melt-spun in a single phase from a circular spinneret at a spinning temperature of 210 ° C. and a single-hole discharge rate of 1.67 g / min. did. Next, the spun yarn shape was cooled with a cooling air flow, and subsequently taken up at 5000 m / min with an air soccer ball, which was opened and deposited on the collecting surface of a moving conveyor to form a web. . Next, the web is passed through a partial thermocompression bonding apparatus composed of an embossing roll, and thermocompression bonding is performed under the conditions of a roll temperature of 100 ° C., a crimping area ratio of 14.9%, a crimping point density of 21.9 pieces / cm ² , and a linear pressure of 196 N / cm. Thus, a long-fiber non-woven web having a basis weight of 130 g / m ^{2 made} of only a polylactic acid polymer having a single yarn fineness of 3.3 dtex was obtained.

Next, 1% by mass of a silicone-based oil agent is attached to the nonwoven web with respect to 100 parts by mass of the fiber, needle punching is performed, and the constituent fibers are three-dimensionally entangled to have a basis weight of 131 g / m ² . A nonwoven fabric was obtained. The needle punching conditions were a needle depth of 10 mm and a needle density of 45 times / cm ² using a # 40 regular barb punch needle. Next, prepare a binder resin solution obtained by diluting an acrylic binder resin solution (trade name “Acrodure 945L” manufactured by BASF) with water, and impregnate the binder resin solution into a nonwoven fabric in which the constituent fibers are entangled three-dimensionally. Thus, a primary base fabric for tufted carpet having a basis weight of 152 g / m ² was obtained by drying and heat treatment. Therefore, the adhesion amount of the binder resin is 14% by mass.

  Table 1 shows the physical properties of the primary base fabric for tufted carpet obtained in Examples 1 to 4 and Comparative Example 1.

In the primary base fabrics for tufted carpets of Examples 1 to 4, the tensile strength in the vertical direction and the horizontal direction in a high temperature atmosphere is 70 N / 5 cm width or more, and in the vertical direction and the horizontal direction in a high temperature atmosphere. The elongation at break is 50% or more, there is little decrease in strength in a high temperature atmosphere, sufficient strength against heat applied in the carpet manufacturing process is maintained, and good heat resistance is exhibited. It was.

  On the other hand, since the primary base fabric for tufted carpet of Comparative Example 1 was composed of fibers made only of a polylactic acid-based polymer, the strength decrease under a high temperature atmosphere was extremely large. The use of was not expected.

[Tufting]
The pile yarn was tufted on the obtained primary base fabric for tufted carpets of Examples 1 to 4 and Comparative Example 1. The pile yarn is 1890 decitex / 108 filament nylon crimped yarn, and the tufting machine has 10 gauges / 2.54cm, 10 stitches / 2.54cm, pile height 5mm, pile yarn usage 447g / m Tufting was performed under the conditions of ² to obtain a living machine in which a pile was planted on the primary base fabric.

  About the obtained raw machine of Examples 1-4 and the comparative example 1, the tensile strength and elongation in room temperature and 130 degreeC atmosphere were measured, and the result is shown in Table 1.

  In the raw machines of Examples 1 to 4, the tensile strength in the vertical direction in a high temperature atmosphere is 70 N / 5 cm width or more, the elongation at break is 50% or more in both the vertical direction and the horizontal direction, and easily in a high temperature atmosphere. It is unlikely to be deformed or sag, has excellent thermal stability against the heat applied in the carpet manufacturing process, and can be expected to be well molded following the molding form during thermoforming. It can be expected to be used for molding carpets.

  On the other hand, the raw machine of Comparative Example 1 was low in both strength and elongation in a high temperature atmosphere and inferior in heat resistance and thermal stability, and good thermoforming could not be expected.

It is a schematic diagram which shows the example of the cross section of the multileaf type composite fiber in this invention. It is a schematic diagram which shows the other example of the cross section of the multileaf type composite fiber in this invention.

Explanation of symbols

1 Core 2 Leaf 3 Multileaf type composite fiber

Claims (6)

A composite long fiber containing an aromatic polyester copolymer and a polylactic acid-based polymer is used as a constituent fiber, and the aromatic polyester copolymer includes terephthalic acid and aliphatic dicarboxylic acid as an acid component, ethylene glycol and diethylene glycol as a glycol component. And having a melting point higher than that of the polylactic acid polymer, the melting point of the polylactic acid polymer is 150 ° C. or higher, and the composite form of the composite long fiber is composed of the polylactic acid polymer as a core. The core-sheath type composite continuous fiber in which the aromatic polyester copolymer forms the sheath, or the polylactic acid polymer forms the core, and the aromatic polyester copolymer is the core A multi-leaf type composite continuous fiber in which a plurality of protruding leaf portions are formed so as to surround the outer periphery of the composite long fiber, and is composed of a composite long fiber unwoven cloth in which the composite long fibers are accumulated, and a vine Primary backing for tufted carpets, characterized in that over the resin is attached. The primary base fabric for tufted carpet according to claim 1, wherein the composite long fibers are woven in a three-dimensional manner in the composite long fiber unwoven cloth in which the composite long fibers are accumulated. The composite ratio (mass ratio) of the polylactic acid polymer and the aromatic polyester copolymer is polylactic acid polymer / aromatic polyester copolymer = 3/1 to 1/3. The primary base fabric for tufted carpet according to 1 or 2. The primary base fabric for tufted carpet according to any one of claims 1 to 3, comprising a sulfonic acid metal salt as an acid component. 2. The tensile strength at 130 ° C. is 50 N / 5 cm width or more in both the vertical and horizontal directions, and the elongation at break at 130 ° C. is 50% or more in both the vertical and horizontal directions. The primary base fabric for tufted carpet according to any one of 4. A tufted carpet in which pile yarn is planted on the primary base fabric for tufted carpet according to any one of claims 1 to 5.