JP2009275306A - Nonwoven fabric of polyester composite filament - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nonwoven fabric of polyester composite filaments, comprising the filaments of composite fibers in which a polyester having excellent crystallinity while having the low melting point is arranged at the sheath parts, enabling the processing at a low temperature when subjected to a thermobonding treatment by allowing the nonwoven fabric to lie in a fiber structure, and providing the fiber structure (product) exhibiting small heat shrinkage, and excellent dimensional stability, heat resistance and flame retardancy. <P>SOLUTION: The nonwoven fabric of the polyester composite filaments is composed of a web obtained by accumulating the composite filaments composed of a polyester A comprising a dicarboxylic acid component consisting essentially of terephthalic acid and a diol component containing ≥50 mol% 1,6-hexanediol, containing 0.01-5.0 mass% nucleating agent, and having 100-150°C melting point (Tm), and an amorphous polyester B, and having 2,000-15,000 ppm content of phosphorus atom in the fiber, and has ≤10% area shrinkage. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is a long-fiber non-woven fabric composed of a web in which a polyester having a low melting point and excellent crystallinity is arranged in a sheath portion, and a long fiber of a composite fiber containing a flame retardant is deposited, and is dimensionally stable The present invention relates to a polyester composite long fiber nonwoven fabric excellent in properties, thermal adhesiveness and flame retardancy.

  Synthetic fibers, especially polyester fibers, are indispensable as clothing and industrial materials due to their excellent dimensional stability, weather resistance, mechanical properties, durability, and recyclability. Many polyester fibers are used.

  In recent years, non-woven structures formed by bonding fibers have been proposed in automobile interior materials, and non-woven structures may be bonded together for the purpose of reinforcing them. Thus, when non-woven structures are bonded to each other, both non-woven structures are formed by interposing a non-woven structure composed of fibers having thermal adhesiveness between the non-woven structure and the non-woven structure, and applying heat treatment. Glue things. As such a non-woven fabric, a non-woven structure is mainly made of a polyester fiber, and therefore, a non-woven fabric made of a polyester polymer is preferable from the viewpoint of recycling.

  And as such a nonwoven fabric, the nonwoven fabric which consists of a long fiber comprised from the polyethylene terephthalate is mentioned, for example, but in the long fiber nonwoven fabric which consists of a polyethylene terephthalate, what functions as an adhesive agent when heat-bonding is a nonwoven fabric Only binder fibers contained therein (fibers made of a polymer having a lower melting point than polyethylene terephthalate). Since the amount of the binder fiber is relatively small, the adhesiveness is weak and easy to peel to bond the non-woven structures to each other with the long-fiber nonwoven fabric.

  In addition, in order to improve the adhesion to the nonwoven structure, a nonwoven fabric comprising a core-sheath type composite long fiber having polyethylene terephthalate as a core and a polyethylene terephthalate copolymer copolymerized with an isophthalic acid component as a sheath. Are also used. Since this non-woven fabric consists of a core portion having a high melting point and a sheath portion having a low melting point, during the heat bonding process, the core portion is not melted and the fiber form is maintained, and only the sheath portion is melted. Strength can be maintained.

  However, since the polyethylene terephthalate copolymer obtained by copolymerizing the isophthalic acid component in the sheath is amorphous and does not exhibit a clear crystal melting point, softening starts at a temperature above the glass transition point. For this reason, there has been a problem that the fibers shrink during the thermal bonding treatment and the dimensional stability of the obtained nonwoven structure deteriorates. In addition, when the bonded non-woven structure is used in a high temperature atmosphere, there is a problem that the bonding strength is reduced and deformed.

  As a solution to the above problem, Patent Document 1 describes a core-sheath type composite fiber. This fiber has a core sheath in which polyethylene terephthalate is disposed in the core portion and a polyester copolymer obtained by copolymerizing a terephthalic acid component, an aliphatic lactone component, an ethylene glycol component, and a 1,4-butanediol component is disposed in the sheath portion. Type composite fiber.

  In this composite fiber, since the copolymer of the sheath part is crystalline and has a clear melting point, the nonwoven fabric using this composite fiber has a small shrinkage during the thermal bonding treatment. For this reason, the dimensional stability of the nonwoven structure bonded using this nonwoven fabric is excellent, and the heat resistance when the bonded nonwoven structure is used in a high-temperature atmosphere is also excellent. .

  However, the copolyester of the sheath part has a melting point in the range of 150 to 200 ° C. and is not yet a low melting point region, and it is necessary to increase the processing temperature during the thermal bonding process, and the cost It was also disadvantageous.

In addition, in automobile interior materials and interior applications, it is also demanded that fiber products such as nonwoven fabric structures obtained by thermal bonding using a long-fiber nonwoven fabric having thermal adhesion have flame retardancy. Therefore, there is a demand for a long-fiber nonwoven fabric composed of binder fibers that can impart good flame retardancy to fiber products.
JP 2006-118066 A

  The present invention solves the above-mentioned problems, is a composite fiber in which a polyester having a low melting point and excellent crystallinity is arranged in the sheath, and is spun with good operability in a normal production apparatus, A non-woven fabric composed of long fibers of a composite fiber that can be obtained by fiberization, and can be processed at a low temperature when heat-bonded by interposing it in a fiber structure or the like. An object of the present invention is to provide a polyester composite long fiber nonwoven fabric that is small and can obtain a fiber structure (product) excellent in dimensional stability, heat resistance, and flame retardancy.

The inventors of the present invention have arrived at the present invention as a result of studies to solve the above problems.
That is, the present invention comprises a dicarboxylic acid component mainly composed of terephthalic acid and a diol component of 1,6-hexanediol of 50 mol% or more, and contains 0.01 to 5.0% by mass of a crystal nucleating agent. The melting point (Tm) is 100 to 150 ° C., the flow start temperature (R) is 105 to 155 ° C., and the difference (R−Tm) between the flow start temperature and the melting point of the polyester A is + 5 ° C. or less. The polyester A is a sheath part, and the polyester B is a core part in the cross-sectional shape of a single yarn, and the content of phosphorus atoms in the fiber Is a long-fiber nonwoven fabric composed of a web on which composite long fibers having a concentration of 2000 to 15000 ppm are deposited, and has a heat-bonding portion at least in part and has an area shrinkage ratio in an atmosphere of (Tm-30) ° C. The polyester composite long fiber nonwoven fabric which is characterized in that 10% or less it is an gist.

  In the polyester composite long fiber nonwoven fabric of the present invention, the polyester A arranged in the sheath portion of the composite fiber is copolymerized with 50 mol% or more of hexanediol as a diol component. Since it is excellent and contains 0.01 to 5.0% by mass of a crystal nucleating agent, the crystallization rate is low when the temperature is lowered. For this reason, one polyester B is an amorphous polymer, but there is no occurrence of welding and breakage between yarns in the spinning process when producing a long-fiber nonwoven fabric, and it has excellent operability and stability. It can be a long-fiber non-woven fabric (with good formation). Furthermore, polyester A is excellent in crystallinity and has a high crystallization rate when the temperature is lowered, so that the thermal shrinkage rate of the fiber can be reduced, and the area shrinkage rate in a (Tm-30) ° C. atmosphere is 10% or less. The long fiber nonwoven fabric can be made. For this reason, when the polyester composite long fiber nonwoven fabric of the present invention is interposed in a fiber structure or the like and thermally bonded, a product with small shrinkage and excellent dimensional stability can be obtained. Further, since the melting point of the polyester A is 100 to 150 ° C., it is possible to lower the temperature and speed of the thermal bonding treatment, which is advantageous in terms of cost.

  At the time of thermal bonding treatment, polyester B is an amorphous polymer and thus has a low fluidity when melted, and polyester A has a high fluidity when melted due to a crystalline polymer. By combining these polyesters, it has moderate fluidity, can be made into a long-fiber nonwoven fabric having a strong adhesive force, and can be suitably used for thermal bonding treatments intervening in fiber structures and the like. It becomes possible.

  Furthermore, since the composite long fiber constituting the polyester composite long fiber nonwoven fabric of the present invention contains phosphorus atoms in the fiber, it becomes an adhesive component having flame retardancy when melted by thermal bonding treatment. By interposing a polyester composite long fiber nonwoven fabric in a fiber structure or the like and heat-bonding it, it becomes possible to impart good flame retardancy to the fiber structure or the like.

  Hereinafter, the present invention will be described in detail. The composite long fiber nonwoven fabric of the present invention is composed of a web on which composite long fibers composed of polyester A and polyester B are deposited. In the present invention, the polyester composite long fiber has a single yarn cross-sectional shape (a cross-sectional shape cut perpendicularly along the fiber axis direction), polyester A is disposed on the sheath of the fiber surface, and polyester B is It exhibits a core-sheath shape arranged in the core part.

  In addition, as such a core-sheath shape, you may have a several core part, and when it has a several core part, it is preferable that the number of core parts shall be 2-10 pieces.

  First, polyester A will be described. Polyester A is composed of a dicarboxylic acid component mainly composed of terephthalic acid and a diol component of 1,6-hexanediol of 50 mol% or more, and has a melting point of 100 to 150 ° C.

  Polyester A has a melting point (Tm) of 100 to 150 ° C, preferably 110 to 140 ° C. When the Tm is less than 100 ° C., the obtained long fiber nonwoven fabric is inferior in thermal stability (heat resistance) when used in a high temperature atmosphere. On the other hand, when it exceeds 150 ° C., it is necessary to increase the heat bonding processing temperature, which is inferior in workability and economy. Further, it is not preferable because the quality and texture of the product obtained by the heat treatment are impaired.

  Polyester A has terephthalic acid as a main component as a dicarboxylic acid component, and terephthalic acid (hereinafter referred to as TPA) is preferably 60 mol% or more, more preferably 80 mol% or more. If the TPA is less than 60 mol%, the melting point of the polymer is not within the scope of the present invention, and the crystallinity tends to be lowered, which is not preferable.

  In addition, as copolymerization components other than TPA, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, 1,3-cyclobutanedicarboxylic acid are used as long as the effects are not impaired. Saturated aliphatic dicarboxylic acids exemplified by acids, 1,4-cyclohexanedicarboxylic acid, dimer acids and the like, or ester-forming derivatives thereof, unsaturated aliphatic dicarboxylic acids exemplified by fumaric acid, maleic acid, itaconic acid and the like Aromatic dicarboxylic acids exemplified by these ester-forming derivatives, phthalic acid, isophthalic acid, 5- (alkali metal) sulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, etc. These ester-forming derivatives can be used.

  As the diol component, 1,6-hexanediol (hereinafter referred to as HD) is 50 mol% or more, and as other components, ethylene glycol (hereinafter referred to as EG) or 1,4-butanediol (hereinafter referred to as HD). BD) is preferably used. In the diol component, HD is 50 mol% or more, and preferably 60 to 95 mol%. When HD is less than 50 mol%, the melting point exceeds 150 ° C.

  When EG or BD is used together with HD as the diol component, EG or BD is preferably 5 to 50 mol%, more preferably 5 to 40 mol% in the diol component.

  Furthermore, the diol component includes other copolymer components other than HD, EG and BD, as long as the properties are not impaired, 1,2-propylene glycol, 1,3-propylene glycol, diethylene glycol, triethylene glycol, tetra For ethylene glycol, 1,4-butylene glycol, 1,5-pentanediol, neopentyl glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, polyethylene glycol, polytrimethylene glycol, polytetramethylene glycol, etc. Exemplified aliphatic glycols, hydroquinone, 4,4′-dihydroxybisphenol, 1,4-bis (β-hydroxyethoxy) benzene, bisphenol A, 2,5-naphthalenediol, ethylene glycol Can be used aromatic glycols Sid is exemplified such as glycol was added.

  Although the above-mentioned polyester A has crystallinity in composition, it is not a thing until the melt | disconnection between the single yarns in the melt spinning process at the time of manufacturing a long-fiber nonwoven fabric is eliminated. Therefore, by containing a crystal nucleating agent in the polyester A, the crystallization speed at the time of cooling can be improved, and the polyester A satisfies the formula (1) described later and causes welding between single yarns. Melt spinning can be performed. Furthermore, it can be set as a long fiber with a low heat shrinkage rate, and a long fiber nonwoven fabric having an area shrinkage rate of 10% or less in an atmosphere at (Tm-30) ° C. can be obtained.

  In the present invention, polyester A contains a crystal nucleating agent in an amount of 0.01 to 5.0% by mass, preferably 0.5 to 4.0% by mass.

  When the content of the crystal nucleating agent is less than 0.01% by mass, the crystallization rate at the time of cooling cannot be improved, the long fiber having a low heat shrinkage rate cannot be obtained, and the area shrinkage rate is low. A long fiber nonwoven fabric cannot be obtained. Moreover, it becomes difficult for polyester A to satisfy the formula (1) described later.

  On the other hand, when the content of the crystal nucleating agent exceeds 5.0% by mass, the content of the crystal nucleating agent is excessively increased, and the operability during melt spinning is deteriorated. And since the operativity deteriorates, the variation in the yarn quality increases, and the area shrinkage rate of the obtained long fiber nonwoven fabric increases.

  As the crystal nucleating agent, it is preferable to use inorganic fine particles, polyolefin, sulfate or the like.

As the inorganic fine particles, those mainly composed of silicon oxide such as talc are preferable, and inorganic fine particles having an average particle size of 3.0 μm or less or a specific surface area of 15 m ² / g or more are preferably used. When the above average particle diameter or specific surface area is not satisfied, the function as a crystal nucleus is poor, and it is difficult to improve the crystallization rate when the temperature is lowered.

  The polyolefin contained as a crystal nucleating agent melts in the reaction system, so the shape is not particularly limited. For example, a chip-like one having a particle size of about 2 mm or a wax-like one having a particle size of several μm It may be.

Examples of polyolefins include olefin homopolymers such as polyethylene, polypropylene, poly-1-butene, polymethylpentene, and polymethylbutene, and propylene / ethylene random copolymers. Polyethylene, polypropylene, poly-1- Butene and propylene / ethylene random copolymers are particularly preferred.
When the polyolefin is a polyolefin obtained from an olefin having 3 or more carbon atoms, it may be an isotactic polymer or a syndiotactic polymer.

  Examples of the sulfate to be contained as a crystal nucleating agent include lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, barium sulfate, calcium sulfate, and aluminum sulfate. And magnesium sulfate are preferred.

  As a method for adding these crystal nucleating agents, they may be added at an arbitrary stage when the polyester is produced in the form of powder or in the form of a diol slurry. For example, it may be added at the time of esterification or transesterification, or may be added at the stage of polycondensation reaction. Among these, in order to improve the effect as a crystal nucleating agent, it is preferable to add in a slurry state or a dissolved state in a glycol such as ethylene glycol.

Furthermore, in the polyester A, the DSC curve showing the temperature-falling crystallization obtained from DSC satisfies the following formula (1), and it is preferable that b / a ≧ 0.06 among them. On the other hand, the larger b / a, the better the crystallinity when the temperature is lowered. However, in order to achieve the intended effect of the present invention, b / a is preferably 0.5 or less.
b / a ≧ 0.05 (mW / mg · ° C.) (1)

  The DSC curve showing the melting temperature of polyester A in the present invention and the temperature-falling crystallization obtained from DSC is a temperature range of −20 ° C. to 250 ° C. in a nitrogen stream using a differential scanning calorimeter (Diamond DSC) manufactured by PerkinElmer. The temperature is measured at a temperature rising (falling) rate of 20 ° C./min and a sample amount of 2 mg (mass of composite long fibers in the long fiber nonwoven fabric).

  Said b / a is calculated | required from the DSC curve which shows the temperature-fall crystallization calculated | required from DSC. As shown in FIG. 1, in the DSC curve of polyester A, a is the temperature A1 (° C.) at the intersection of the tangent line and the base line having the maximum inclination in the DSC curve indicating the temperature-falling crystallization, and the inclination is minimum. Is the difference (A1-A2) between the temperature A2 (° C.) at the intersection of the tangent and the base line, and b is the heat amount B1 (mW) of the base line and the heat amount B2 (mW) of the peak top at the peak top temperature. (B1-B2) divided by the amount of sample (mg).

  b / a is an index representing the crystallinity when the temperature is lowered, and the higher the b / a value, the faster the crystallization rate, and vice versa, the closer to 0, the slower the crystallization rate. When b / a is less than 0.05 (mW / mg · ° C.), the crystallization rate is low, so that welding between single yarns occurs during melt spinning, and the spinning operability deteriorates. Even if the yarn is produced by increasing the distance between the spinneret and the take-up means in order to cool the yarn more sufficiently, the yarn is swayed and the opening property is inferior, and the resulting nonwoven fabric is inferior in quality. It will be a thing. Furthermore, the area shrinkage rate of the obtained long fiber nonwoven fabric is also increased.

  As described above, b / a can be in the range specified in the present invention by setting the copolymer composition of polyester to a specific value and the content of the crystal nucleating agent in the above range. .

  Next, polyester B will be described. Polyester B is an amorphous polyester having a flow start temperature (R) of 105 to 155 ° C., and a difference (R−Tm) between the flow start temperature and the melting point (Tm) of polyester A is + 5 ° C. or less. It is.

  That is, in the polyester composite long fiber nonwoven fabric of the present invention, it is preferable that both polyester A and polyester B are melted by thermal bonding treatment to form an adhesive component. Usually, the thermal bonding temperature is arranged on the fiber surface. In order for the polyester B to melt at such a heat bonding treatment temperature, the flow start temperature of the polyester B may be higher than the melting point of the polyester. It is necessary to set the temperature to 5 ° C. or lower, and above all, it is preferably lower than the melting point of polyester A.

  Moreover, although the flow start temperature of the polyester B is 105-155 degreeC, it is preferable that it is 110-140 degreeC, especially 115-135 degreeC especially.

  When the flow start temperature of polyester B is lower than 105 ° C., heat treatment cannot be performed in the production process of the long fiber nonwoven fabric, and the heat shrinkage rate of the long fiber becomes high, and the area shrinkage rate of the obtained long fiber nonwoven fabric Is expensive. On the other hand, when it exceeds 155 ° C., it is necessary to increase the heat bonding treatment temperature when obtaining the product, and the processability and the economical efficiency are inferior.

  As the polyester B, those mainly composed of polyalkylene terephthalate such as polyethylene terephthalate (PET), polybutylene terephthalate, and polytrimethylene terephthalate are preferable. And in order to set it as the thing of said flow start temperature, it is preferable to use what was copolymerized the following components.

  Examples of copolymer components include aromatic dicarboxylic acids such as isophthalic acid and 5-sulfoisophthalic acid, aliphatic dicarboxylic acids such as adipic acid, succinic acid, suberic acid, sebacic acid, and dodecanedioic acid, and ethylene glycol, propylene glycol, Aliphatic diols such as 1,4-butanediol and 1,4-cyclohexanedimethanol, and hydroxycarboxylic acids such as glycolic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid, hydroxypentanoic acid, hydroxyheptanoic acid and hydroxyoctanoic acid Examples thereof include aliphatic lactones such as acid and ε-caprolactone.

  Among them, as polyester B, it is preferable to use PET copolymerized with isophthalic acid, and among them, those obtained by copolymerizing 25 to 40 mol% of isophthalic acid are preferable. When the copolymerization amount of isophthalic acid is less than 25 mol%, the flow start temperature becomes high and tends to exceed 155 ° C. On the other hand, if it exceeds 40 mol%, the flow start temperature tends to be low and tends to be less than 105 ° C.

  And the composite long fiber in this invention contains 2000-15000 ppm of phosphorus atoms, and it is preferable to contain 4000-10000 ppm especially. That is, a phosphorus compound is contained in either one or both of polyester A and polyester B constituting the composite long fiber. Then, both polyester A and polyester B are melted by thermal bonding treatment to become an adhesive component having flame retardancy.

  If the content of phosphorus atoms in the composite long fiber is less than 2000 ppm, the flame retardant performance of the adhesive component becomes insufficient. On the other hand, if the content exceeds 15000 ppm, the content of the phosphorus compound increases, so the production process of spinning and nonwoven fabric As a result, the operability becomes poor, and a long-fiber nonwoven fabric with poor formation is obtained.

  As a method for incorporating a phosphorus atom in the composite long fiber, it is preferable to copolymerize polyester A or polyester B with a phosphorus compound.

  Examples of phosphorus compounds include phosphate esters and derivatives thereof, phosphonic acids and derivatives thereof, phosphinic acids and derivatives thereof, and these can be used alone or in combination of two or more.

  Specific examples of phosphate esters and derivatives thereof include trimethyl phosphate, triethyl phosphate, and tripropyl phosphate. Specific examples of phosphonic acids and derivatives thereof include phenylphosphonic acid, dimethylphosphonic acid, and diethylphosphonic acid. Specific examples of phosphinic acid and its derivatives include phosphorane, a maleic acid adduct of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, an itaconic acid adduct, and the like. Moreover, the compound etc. which added ethylene carbonate to the reaction material of diphenylphosphine oxide and p-benzoquinone are mentioned.

  Polyester A and polyester B include stabilizers, cobalt compounds, fluorescent brighteners, color tone improvers such as dyes, matting agents such as titanium dioxide, plasticizers, pigments, antistatic agents, and easy dyes. One or more kinds of various additives such as an agent may be added.

  The composite ratio (mass ratio) of polyester A and polyester B of the composite long fiber in the present invention is preferably 20/80 to 80/20, and more preferably 30/70 to 70/30.

  As long as the cross-sectional shape of the single yarn of the polyester composite long fiber constituting the composite long-fiber nonwoven fabric of the present invention has a core-sheath shape, the cross-sectional shape is not only a round shape but also a flat shape or a polygonal shape such as a square or a triangle. The shape may be sufficient.

  Furthermore, the single yarn fineness of the polyester composite long fiber is not particularly limited, but is preferably 1 to 15 dtex. When the single yarn fineness is less than 1 dtex, single yarn cutting frequently occurs in the spinning and take-up processes, the operability is deteriorated, and the strength of the resulting nonwoven fabric tends to be inferior. On the other hand, if the single yarn fineness exceeds 15 dtex, the cooling property of the spun yarn becomes insufficient, which is not preferable.

  Next, the composite long fiber nonwoven fabric of the present invention is composed of a web on which the composite long fibers composed of the above-described polyester A and polyester B are deposited. From the viewpoint of form stability, at least a part of the web is heated. It has an adhesive part.

  That is, it has at least a part of a heat-bonded portion in which the long fibers constituting the web are melted or softened and bonded. Among them, one in which a part of the web is thermally bonded is preferable, and examples include one in which only a part of the web surface is thermally bonded, and one in which only the entire surface of the web (one side) is thermally bonded.

  The entire web may be heat-bonded, but such a non-woven fabric that has been heat-bonded to the entire surface becomes a film and has a small thickness.

  In addition, in the heat-bonded portion where the long fibers constituting the web are melted or softened and bonded, even if only polyester A is melted to form a heat-bonded portion, polyester B is also melted together with polyester A. You may comprise the heat bonding part.

  As a method of manufacturing a web, a polymer that has been spun from a composite spinning device and lowered to a fiberable temperature is sucked and stretched by air soccer using a high-speed air current, and then opened using a fiber opening device to form a conveyor-like net. Heated high-speed gas is sprayed on a fine stream of molten polymer spun from a spunbond method or spinning device that collects the web, and the molten polymer is stretched by the action of the gas flow to make it extremely fine and collected. There is a melt blow method for obtaining a web. Among them, in the present invention, it is preferable that the web is manufactured by a spunbond method.

  And, as a method for thermally bonding at least a part of the web, a thermocompression bonding method using a hot embossing device or an ultrasonic welding device, a hot air circulation method using dry heat such as a hot air dryer, a wet heat method using heating steam In addition, a method using an ultrasonic welding apparatus can be effectively used.

  First, examples of the above-described thermocompression bonding method include a method using a pair of embossing rolls, a partial thermocompression bonding apparatus including an embossing roll and a flat roll, or a full surface thermocompression bonding apparatus including a pair of flat rolls.

  In the partial thermocompression bonding, long fibers existing at a portion in contact with the convex portion of the embossing roll are melted or softened to form a dotted fused area, and the fibers are bonded to each other by the fused area. Each fused area may be any shape such as a circle, an ellipse, a diamond, a triangle, a T-shape, or a well.

  In the entire surface thermocompression bonding, long fibers existing on the web surface are melted or softened and thermally bonded together. Before passing through the entire surface thermocompression bonding apparatus, a partial temporary thermocompression bonding process may be applied to the web formed on the moving deposition apparatus, if necessary, for example, in order to easily carry the transfer work.

  The ultrasonic fusion apparatus is an apparatus that includes an ultrasonic oscillator that oscillates an ultrasonic wave of about 20 kHz, and a pattern roll that has convex protrusions in the form of dots or bands on the circumference. A web is passed between a support having an ultrasonic oscillator and an ultrasonic wave of about 20 kHz is oscillated for point pressure bonding.

  When adopting a hot air circulation method using dry heat or a wet heat method using heating steam, the long fibers at the fiber intersections on the web surface are melted or softened and bonded at the intersections of the fibers. In addition, as a heating steam, it can heat-process effectively by using the apparatus which can pressurize.

  The composite long fiber nonwoven fabric of the present invention has an area shrinkage of 10% or less in an atmosphere at (Tm-30) ° C. That is, the long fiber (composite fiber) constituting the long-fiber nonwoven fabric of the present invention has a low thermal shrinkage because polyester A having excellent crystallinity and a high temperature-falling crystallization rate is arranged in the sheath. The area shrinkage rate of the long fiber nonwoven fabric can be 10% or less. In particular, the area shrinkage rate is preferably 8.5% or less, and more preferably 8.0% or less. The area shrinkage rate is obtained as follows.

The composite long fiber nonwoven fabric was cut into an area A0 (20 cm × 20 cm = 400 cm ² ) as a sample, and this was left in a hot air dryer maintained at (Tm-30) ° C. for 15 minutes. The area of the non-woven fabric is A1, and the area shrinkage rate is obtained by the following formula.
Area shrinkage (%) = {(A0−A1) / A0} × 100

  Since the area shrinkage of the composite long-fiber nonwoven fabric is 10% or less, the shrinkage at the time of thermal bonding treatment is small, the shrinkage at the time of interposing between the fiber structures and the like is small, and the resulting product (fiber Structures and the like) have excellent dimensional stability. When the area shrinkage rate exceeds 10%, the heat shrinkage rate increases, and the product obtained by heat bonding using the long-fiber nonwoven fabric of the present invention has a large shrinkage when subjected to heat bonding treatment, resulting in dimensional stability. It will be inferior.

  In addition, the long fiber nonwoven fabric of the present invention has a low thermal shrinkage rate of the long fibers composed of polyester A and polyester B even in the process of thermally bonding at least a part of the web when obtaining the long fiber nonwoven fabric. It also has excellent dimensional stability when obtaining a nonwoven fabric.

And the fabric weight of the long fiber nonwoven fabric of this invention is although it does not specifically limit, It is preferable that it is 10-300 g / m < ² >. If the basis weight is less than 10 g / m ² , the formation and mechanical strength are inferior, and it tends to be unusable for practical use. On the other hand, when the basis weight exceeds 300 g / m ² , it is disadvantageous in terms of cost.

  Thus, since the composite long fiber which comprises the composite long fiber nonwoven fabric of this invention is a composite fiber which consists of the above polyester A and polyester B, polyester A and polyester B fuse | melt by low-temperature heat processing. It is preferable that both polyesters are melted to form a thermal adhesive component. And it has a strong adhesive force from the difference in fluidity between polyester A and polyester B. In other words, when the composite long fiber nonwoven fabric of the present invention is interposed between fiber structures and the like and subjected to heat treatment and adhesion, since polyester A has high fluidity, most of them penetrate into the structure, and anchor effect And adhesive strength increases. On the other hand, since polyester B has low fluidity, most of the polyester B is present on the bonding surface of the structure, thereby increasing the adhesive strength. Therefore, these two effects combine to have a strong adhesive strength. Therefore, the composite long-fiber nonwoven fabric of the present invention is suitable for use in applications in which structures are bonded to each other by being heat-treated by interposing between fiber structures and the like. ) Can be obtained.

Next, the present invention will be specifically described using examples. The measurement and evaluation methods for various characteristic values in the examples are as follows.
(A) Intrinsic viscosity [η]
Measurement was carried out based on a conventional method under the conditions of a sample concentration of 0.5% by mass and a temperature of 20 ° C. using an equal mass mixture of phenol and ethane tetrachloride as a solvent.
(B) Melting point of polyester A, DSC curve showing temperature drop crystallization determined from DSC Measured by the above method.
(C) Flow start temperature of polyester B Using a flotester (Shimadzu CFT-500 type), the temperature was increased at a rate of 10 ° C./minute from an initial temperature of 50 ° C. under a load of 9.8 MPa and a nozzle diameter of 0.5 mm. The temperature was determined as the temperature at which the polymer began to flow out of the die.
(D) Polymer composition of polyester A and polyester B The obtained polyester composite short fiber was dissolved in a mixed solvent having a volume ratio of 1/20 of deuterated hexafluoroisopropanol and deuterated chloroform, and LA- 1H-NMR was measured with a 400-type NMR apparatus, and obtained from the integrated intensity of the proton peak of each copolymer component in the obtained chart.
(E) Fineness JIS L 1015 Positive fineness Fineness was measured by A method.
(F) Basis weight After making 10 samples of 10 cm in length × 10 cm in width from the obtained long fiber nonwoven fabric and reaching the equilibrium moisture, the mass (g) of each sample piece was weighed, and the average of the obtained values The value was converted to a unit area (g / m ² ) per unit area.
(G) Spinning operability The following two stages were evaluated according to the spinning conditions.
A: The number of cut yarns during spinning is 1 / ton or less, and there is no welding between single yarns.
X: The number of cut yarns during spinning exceeds 1 time / ton, or welding occurs between single yarns.
(H) Formation The formation of the surface of the obtained nonwoven fabric was visually evaluated in two stages: good (◯) and defective (×).
(I) Area shrinkage rate Measured by the above method.
(J) Adhesive strength (N)
Polyethylene terephthalate fiber (fiber length 51 mm, fineness 2.2 T) and unite polyester-based core-sheath composite binder fiber <7080> (fiber length 51 mm, fineness 2.2 T) are blended in a mass ratio of 1: 1 to provide a card. A web having a basis weight of 400 g / m ² is prepared by a machine and subjected to a fusion treatment under a heat treatment condition of 180 ° C. × 60 seconds using a hot air dryer to obtain a short fiber nonwoven fabric.
Further, the obtained composite long fiber nonwoven fabric is sandwiched between the two short fiber nonwoven fabrics, the thickness of the laminated nonwoven fabric is regulated to 5 mm, and the heat treatment conditions (melting point of polyester A are measured using a hot air dryer). +10) A fusing treatment is performed at 100 ° C. for 100 seconds to produce a laminate having a thickness of 5 mm. Five sample pieces having a sample length of 20 cm and a sample width of 5 cm were prepared from the laminate, 10 cm between the two pieces of the short fiber nonwoven fabric of the sample piece was peeled, and the peeled portion was gripped and stretched at an interval of 5 cm and a tensile speed of 10 cm / min. The peel strength (N / 5 cm) was measured. And the average value of 5 sample pieces was made into adhesive strength (N).
In the present invention, this adhesive strength is preferably 20 N or more. Here, the adhesive strength means that after the composite long fiber nonwoven fabric is integrated with the short fiber nonwoven fabric (fiber structure), the composite long fiber nonwoven fabric is melted to integrate the short fiber nonwoven fabrics, and then between the short fiber nonwoven fabrics. It is a strong value required when peeling off.
If the adhesive strength is less than 20N, the adhesive strength with the fiber structure is inferior, and the integrated fiber structure is likely to peel off during use.
(K) Flame retardancy The obtained composite long-fiber non-woven fabric was evaluated with a limiting oxygen index (LOI) according to Fire Safety No. 65, and an LOI value of 30 or more was regarded as acceptable.

Example 1
The slurry of TPA and EG is continuously supplied to the esterification reactor and reacted under the conditions of a temperature of 250 ° C. and a pressure of 0.2 MPa, and a residence time of 8 hours is obtained to obtain a reaction product with an esterification reaction rate of 95%. It was. This reaction product was transferred to a polycondensation reaction vessel, HD was charged into the polycondensation reaction vessel, and stirred at a temperature of 240 ° C. and normal pressure for 1 hour. Next, an EG slurry containing talc having an average particle size of 1.0 μm and a specific surface area of 35 m ² / g as a crystal nucleating agent and a phosphorus compound described in the chemical formula (1) is charged into a polycondensation reaction vessel, and then reacted. The pressure in the vessel was gradually reduced, and the polycondensation reaction was carried out for about 3 hours with stirring, and the resultant was discharged into a strand by a conventional method to form chips. The obtained polyester A is composed of 87 mol% TPA as an acidic component, 13 mol% phosphorus compound, 2 mol% EG as a glycol component, 98 mol% HD, contains 0.5% by mass of talc as a crystal nucleating agent, has an intrinsic viscosity of 0.95, The copolymer was such that the melting point was 128 ° C. and the phosphorus atom content was 12000 ppm (A-1 in Table 2).
As polyester B, PET (flow start temperature 130 ° C., intrinsic viscosity 0.79, B-1 in Table 3) copolymerized with 33 mol% of isophthalic acid as an acid component was used.
A polyester A chip and a polyester B chip are supplied to a compound spinning device so that the polyester A has a sheath and polyester B has a core-sheath shape, and the mass ratio of both components is 50/50. More melt spinning was performed. At this time, melt spinning was performed at a spinning temperature of 220 ° C. and a single hole discharge rate of 1.00 g / min.
Next, the spun yarn was cooled with a cooling air flow, and then a web was produced by the spunbond method. First, it was taken up at 3000 m / min by air soccer, and this was opened and deposited on the collecting surface of a moving conveyor to form a nonwoven web. Next, this nonwoven web was passed through a partial thermocompression bonding apparatus consisting of an embossing roll and a flat roll, and the roll temperature was 100 ° C., the crimping area ratio was 14.9%, the crimping point density was 21.9 pieces / cm ² , and the linear pressure was 500 N / cm. The composite long-fiber nonwoven fabric having a basis weight of 40 g / m ² made of composite long fibers having a phosphorus atom content of 6000 ppm and a single yarn fineness of 3.3 dtex was obtained.

Example 2, Comparative Examples 1-2
A polyester composite long fiber nonwoven fabric was obtained in the same manner as in Example 1 except that the polyesters B-2 to B-4 in Table 3 were used as the polyester B.

Examples 3-4, Comparative Examples 3-4
Except that the polyesters A-2 to A-5 in Table 2 were used as the polyester A and the phosphorus atom content in the composite long fiber was as shown in Table 1, it was the same as in Example 1. A polyester composite long fiber nonwoven fabric was obtained.

Example 5
TPA, HD, BD are supplied to the esterification can, talc having an average particle size of 1.0 μm and a specific surface area of 35 m 2 / g as a crystal nucleating agent, and 17 mol% of a phosphorus compound described in chemical formula (1) are added, The mixture was stirred for 3 hours under the conditions of a temperature of 230 ° C. and a pressure of 0.2 MPa to carry out an esterification reaction, and then transferred to a polycondensation reaction can. Then, the pressure in the reactor was gradually reduced, and the polycondensation reaction was carried out for about 3 hours with stirring, and the strand was discharged into a strand by a conventional method to form chips. The obtained polyester A is composed of 87 mol% of TPA as an acidic component, 13 mol% of a phosphorus compound, 1 mol% of 1,4-butanediol (BD) as a glycol component, and 99 mol% of HD, and 0.5% by mass of talc as a crystal nucleating agent. And an intrinsic viscosity of 0.98, a melting point of 130 ° C., and a copolymer so that the phosphorus atom content is 12000 ppm (A-6 in Table 2).
A polyester composite long fiber nonwoven fabric was obtained in the same manner as in Example 1 using the same polyester B (B-1 in Table 3) as in Example 1.

Comparative Example 5
A long-fiber nonwoven fabric was obtained in the same manner as in Example 1 except that only A-1 in Table 2 was supplied to the spinning device as polyester A and melt-spun at a spinning temperature of 220 ° C. and a discharge rate of 1.00 g / min.

Example 6
Polyester A consists of TPA as an acidic component, 15 mol% of EG as a glycol component, and 85 mol% of HD, contains 0.5% by mass of talc as a crystal nucleating agent, has an intrinsic viscosity of 0.95, and a melting point of 128 ° C. (Table 2 A-7) was used.
To the esterification can, TPA, IPA, EG and the phosphorus compound described in chemical formula (1) are added and stirred for 3 hours under conditions of a temperature of 240 ° C. and a pressure of 0.2 MPa. The product was transferred to a condensation reaction can. Then, the pressure in the reactor was gradually reduced, and the polycondensation reaction was carried out for about 3 hours with stirring, and the strand was discharged into a strand by a conventional method to form chips. The obtained polyester B has an acid content of TPA of 67 mol%, isophthalic acid of 25 mol%, a phosphorus compound of 8 mol%, a glycol component of hexanediol (HD) of 100 mol%, an intrinsic viscosity of 0.79, a melting point of 115 ° C., and a phosphorus atom content. It was copolymerized to 12000 ppm (B-5 in Table 3).
And it carried out similarly to Example 1, and obtained the composite long fiber nonwoven fabric.

Examples 7-8, Comparative Examples 6-7
The composite length was the same as in Example 1 except that the same polyester A as in Example 6 (A-7 in Table 2) was used and the polyesters B-6 to B-9 in Table 3 were used as the polyester B. A fiber nonwoven fabric was obtained.

Comparative Example 8
Using the same polyester A as in Example 6 (A-7 in Table 2) and using the same polyester B as in Example 1 (B-1 in Table 3), a composite long fiber nonwoven fabric was prepared in the same manner as in Example 1. Obtained.

  Table 1 shows the characteristic values and evaluation results of the composite long fibers and the long fiber nonwoven fabrics obtained in Examples 1 to 8 and Comparative Examples 1 to 8.

As apparent from Table 1, the composite long fiber nonwoven fabrics of Examples 1 to 8 can be obtained with good spinning operability, have good formation, have a low area shrinkage rate, and from other polyester fibers. It was excellent in adhesive strength with the resulting structure and also in flame retardancy.
Since the composite long fiber nonwoven fabric of Comparative Example 1 uses a copolymerized PET having a high flow start temperature as the polyester B, the polyester B does not melt in the heat bonding treatment when bonding a structure made of other fibers or the like, The power was low. In the composite long fiber nonwoven fabric of Comparative Example 2, copolymerized PET having a low flow start temperature was used as polyester B. Therefore, cut yarn was generated during spinning, the formation was poor, and the area shrinkage ratio was high. Since the composite long fiber nonwoven fabrics of Comparative Examples 3 and 6 contained too little phosphorus atom in the composite long fibers, the composite long fiber nonwoven fabric of Comparative Example 8 did not contain phosphorus atoms in the composite long fibers. Therefore, all were inferior in flame retardance. In Comparative Examples 4 and 7, since the content of phosphorus atoms in the polyester A or the polyester B was too large, the composite long fiber could not be spun and a nonwoven fabric could not be obtained. The long-fiber non-woven fabric of Comparative Example 5 is a non-woven fabric consisting only of polyester A, and has no adhesive strength because there is no polyester B having different fluidity.

It is an example of the DSC curve which shows the temperature-fall crystallization calculated | required from DSC of the polyester A in the polyester composite long fiber nonwoven fabric of this invention.

Claims (3)

It consists of a dicarboxylic acid component mainly composed of terephthalic acid and a diol component of 1,6-hexanediol of 50 mol% or more, contains 0.01 to 5.0% by mass of a crystal nucleating agent, and has a melting point (Tm). Amorphous that has a polyester A of 100 to 150 ° C., a flow start temperature (R) of 105 to 155 ° C., and a difference (R−Tm) between the flow start temperature and the melting point of polyester A is + 5 ° C. or less. The cross-sectional shape of the single yarn is composed of polyester B, has a sheath-core shape in which polyester A is a sheath portion, and polyester B is a core portion, and the phosphorus atom content in the fiber is 2000 to 15000 ppm. It is a long-fiber non-woven fabric composed of a web on which composite long fibers are deposited, and has a heat-bonding portion at least in part and has an area shrinkage of 10% or less in an atmosphere at (Tm-30) ° C. Polyester composite long fiber nonwoven fabric characterized by. The polyester composite long fiber nonwoven fabric according to claim 1, wherein a DSC curve showing temperature-fall crystallization determined from DSC of polyester A satisfies the following formula (1).
b / a ≧ 0.05 (mW / mg · ° C.) (1)
Note that a is the temperature A1 (° C.) of the intersection between the tangent line and the baseline having the maximum inclination in the DSC curve indicating the temperature-falling crystallization, and the temperature A2 (° C.) of the intersection of the tangent line and the baseline having the minimum inclination. B) is the difference (B1-B2) between the baseline heat quantity B1 (mW) and the peak top heat quantity B2 (mW) at the peak top temperature (mg) The value divided by. The polyester composite long-fiber nonwoven fabric according to claim 1 or 2, wherein the web on which the long fibers of the composite fiber are deposited is produced by a spunbond method.