JP4851644B2 - Long fiber nonwoven fabric with excellent moldability - Google Patents

Description

【００２７】
（２）引張強力および５％伸長時応力
ＪＩＳ Ｌ−１９０６に準じて測定した。
（３）目付
ＪＩＳ Ｌ−１９０６に規定の方法で測定した。
〔参考例１〕
極限粘度［η］が０．９２であるポリトリメチレンテレフタレートを２６５℃で溶融紡糸し、エジェクターで吸引しながら紡糸速度５０００ｍ／ｍｉｎで延伸し、移動する多孔質帯状体に捕集・堆積させて長繊維ウェブを作成した。
【００２８】
このウェブに、ノズル径０．１５ｍｍ、ノズルピッチ０．８ｍｍ、列数２列の多数のノズルから水圧４．９×１０³ｋＰａ〔ｇａｕｇｅ〕の柱状流を噴射して繊維を交絡させた。ノズルと長繊維ウェブの間隔は２５ｍｍで、ウェブは１６ｍ／ｍｉｎの速度で移動するステンレス製メッシュスクリーンで支持され、メッシュスクリーンを通して吸引脱水させた。同様の処理をシートの反対側にも施し、目付５０ｇ／ｍ²の長繊維不織布を得た。
【００２９】
この不織布のタテ方向の物性を測定した結果を、表１に示す。
〔実施例２〕
参考例１において、紡糸速度３５００ｍ／ｍｉｎで延伸したこと以外は、参考例１と同様にしてウェブを得た。次いで、参考例１と同様の方法・条件で柱状流加工を施し、目付５０ｇ／ｍ²の長繊維不織布を得た。
【００３０】
この不織布のタテ方向の物性を測定した結果を、表１に示す。
〔参考例３〕
極限粘度［η］が０．６６であるポリトリメチレンテレフタレートを２７０℃で溶融紡糸し、エジェクターで吸引しながら紡糸速度４６００ｍ／ｍｉｎで延伸し、移動する多孔質帯状体に捕集・堆積させて長繊維ウェブを作成した。次いで、このウェブを一対の金属製の加熱ロールにより熱圧着させ、目付５０ｇ／ｍ²の長繊維不織布を得た。加熱ロールの一方は、表面にエンボス模様が加工されており、もう一方の表面はフラット状である。
【００３１】
この不織布のタテ方向の物性を測定した結果を、表２に示す。
また、比較の対象として、ポリエチレンテレフタレート長繊維不織布（旭化成工業社製「Ｅ０１０５０」目付５０ｇ／ｍ²）と、ナイロン６長繊維不織布（旭化成工業社製「Ｎ０１０５０」目付５０ｇ／ｍ²）のタテ方向の物性を同様に表２に示す。
【００３２】
〔比較例１〕
ナイロン６ポリマーを用いて２６５℃で溶融紡糸し、紡糸速度４５００ｍ／ｍｉｎで延伸したこと以外は、参考例１と同様にしてウェブを作成し、参考例１と同様に、水圧３．９×１０³ｋＰａ〔ｇａｕｇｅ〕で柱状流加工を施し、目付５０ｇ／ｍ²の長繊維不織布を得た。
この不織布のタテ方向の物性を測定した。結果を表１に示す。
【００３３】
〔比較例２〕
極限粘度［η］が０．７１のポリエチレンテレフタレートを用いて３００℃で溶融紡糸し、紡糸速度４４００ｍ／ｍｉｎで延伸したこと以外は、参考例１と同様にしてウェブを作成し、参考例１と同様に、水圧４．９×１０³ｋＰａ〔ｇａｕｇｅ〕で柱状流加工を施し、目付５０ｇ／ｍ²の長繊維不織布を得た。
【００３４】
この不織布のタテ方向の物性を測定した結果を、表１に示す。
【００３５】
【表１】

【００３６】
【表２】

【００３７】
【発明の効果】
本発明の不織布は、低モジュラスかつ高伸度で、成型性に優れた長繊維不織布であり、その特徴を活かしてスキンクロス用途などに有用である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a long-fiber nonwoven fabric having low modulus, high elongation, and excellent moldability.
[0002]
[Prior art]
Polytrimethylene terephthalate obtained by polycondensation of lower alcohol ester of terephthalic acid represented by terephthalic acid or dimethyl terephthalate and trimethylene glycol (1,3-propanediol) has excellent elastic recovery and low elasticity. It is an epoch-making polymer that has properties similar to those of polyamide such as rate and dyeability, and properties similar to polyethylene terephthalate such as light resistance, heat setting properties, dimensional stability, and low water absorption. It is applied to carpets, brushes, tennis guts, etc. (Japanese Patent Laid-Open Nos. 9-3724, 8-173244, and 5-262862).
[0003]
In addition, in the existing spunbond nonwoven fabric, which is a typical long-fiber nonwoven fabric, nonwoven fabrics made of polymers such as polyamide, polyester, and polyolefin are marketed, and these are generally constituted by thermocompression bonding of filaments, It is characterized by high tensile strength and tear strength. Furthermore, a long-fiber nonwoven fabric made of poly (ethylene methylene terephthalate) having an appropriate stretchability, soft texture, and uniform basis weight has also been proposed (Japanese Patent Laid-Open No. 11-1000076). These nonwoven fabrics are useful for uses such as packaging materials for disposable warmers, living materials such as furoshiki, table cloth, sanitary materials such as disposable diapers, and civil engineering materials.
[0004]
However, these long-fiber non-woven fabrics have the disadvantages that the thermocompression bonding is used for joining the filaments, so that the elongation at break is low, the texture is hard, and the drapeability is lacking. Therefore, when the nonwoven fabric is deep-drawn or when it is bonded to an object of a certain shape without a gap, when the modulus is high, the nonwoven fabric stretches and a gap is generated, and when the elongation is low There was a problem that the stressed portion was broken.
[0005]
In particular, it is complex and highly moldable for fabric use that is used as an auxiliary material by being bonded to cushion materials (urethane foam, etc.) of vehicle seats for railway vehicles, automobile vehicles, ships, etc., called lining cloth (skin cloth). Is required. In addition, as other required characteristics, it is desired that the strength is large, that there is little generation of yarn waste and yarn waste at the time of cutting, excellent followability to the skin, inexpensiveness, etc. As a representative material, tricot fabric is used.
[0006]
The tricot fabric is stretched with low stress (ie, has a low modulus) and has a high elongation due to the characteristics of the production method, and is excellent in followability of the epidermis and widely used as a skin cloth. However, since it is a woven fabric, it is inevitable and expensive to scatter the yarn during cutting.
Non-woven fabrics, on the other hand, have no defects in cutting and are inexpensive because of their high productivity. However, they have disadvantages such as high modulus and difficulty in stretching, so these disadvantages are overcome and comparable to tricot fabrics. There is a demand for nonwoven fabrics with excellent moldability.
[0007]
Therefore, studies have been made to provide a nonwoven fabric having a higher strength and a soft texture than conventional nonwoven fabrics. For example, the fabric weight is composed of polytrimethylene terephthalate fibers and entangled by a columnar flow. A nonwoven fabric having an amount of 30 to 200 g / m ² has been proposed (Japanese Patent Laid-Open No. 11-107149).
However, the moldability of the nonwoven fabric described in the publication is not always sufficient.
[0008]
[Problems to be solved by the invention]
The subject of this invention is providing the long-fiber nonwoven fabric excellent in the moldability suitable for the use where complicated and high moldability is requested | required like a back fabric (skin cloth).
[0009]
[Means for Solving the Problems]
As a result of detailed investigations from the viewpoint of the structural design of the nonwoven fabric in order to improve the elongation characteristics of the long-fiber nonwoven fabric, the present inventors have found that the above-mentioned problem is caused by using long fibers made of a specific polytrimethylene terephthalate. It was found that the problem was solved and the present invention was reached.
[0010]
That is, the present invention is composed of long fibers made of polytrimethylene terephthalate having an intrinsic viscosity [η] of 0.4 to 2.0, has a longitudinal elongation at break of 60% or more, and a stress at 5% elongation of 5%. A long fiber nonwoven fabric characterized by being 6 N / 3 cm or less, and a skin cloth composed of the long fiber nonwoven fabric.
The intrinsic viscosity [η] of the polytrimethylene terephthalate used in the present invention is 0.4 to 2.0, preferably 0.5 to 1.5, and more preferably 0.6 to 1.2. Within this range, a fiber excellent in strength and spinnability can be obtained. When the intrinsic viscosity is less than 0.4, the melt viscosity of the polymer is too low, so that the spinning becomes unstable, and the strength of the resulting fiber is not satisfactory. When the intrinsic viscosity exceeds 2.0, the melt viscosity is too high, so that melt fracture or spinning failure occurs during spinning.
[0011]
The long fiber nonwoven fabric of the present invention has a longitudinal elongation at break of 60% or more and a stress at 5% elongation of 6 N / 3 cm or less.
The breaking elongation in the vertical direction is related to the ability to follow the form of complicated and advanced deformation when a long fiber nonwoven fabric is molded as a skin cloth. If the breaking elongation in the vertical direction is less than 60%, it is insufficient for complex and high formability as a skin cloth. Further, if the breaking elongation in the vertical direction exceeds 300%, the skin cloth surface tends to become uneven during molding. Therefore, the breaking elongation in the vertical direction is preferably 80 to 300%, more preferably 130 to 250%.
[0012]
The stress at 5% elongation in the vertical direction is related to the beauty of a product formed from a long fiber nonwoven fabric as a skin cloth. If the stress at 5% elongation in the vertical direction exceeds 6 N / 3 cm, the concave part of the bent part of the molded product is rounded and the sharp shape is impaired. Further, if the stress at 5% elongation in the vertical direction is less than 0.2 N / 3 cm, the skin cloth surface of the molded product tends to become wrinkles. Therefore, the stress at 5% elongation in the vertical direction is preferably 0.2 to 5 N / 3 cm, and more preferably 0.5 to 2 N / 3 cm.
[0013]
The fineness of the filament constituting the long fiber nonwoven fabric of the present invention is preferably 0.5 to 5 dtex. If it is greater than 5 dtex, the resulting nonwoven fabric tends to be stiff due to insufficient cooling. On the other hand, if it is smaller than 0.5 dtex, the filament cannot sufficiently withstand the tension of the ejector during spinning, and part of the filament may be broken. The fineness of the filament is preferably 1 to 4 dtex. Moreover, it is preferable that the fabric weight of a nonwoven fabric is 10-100 g / m < ² >.
[0014]
In the present invention, polytrimethylene terephthalate refers to a trimethylene terephthalate unit as a main repeating unit, and the trimethylene terephthalate unit is about 50 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more. Particularly preferably, it means 90 mol% or more. Therefore, the total amount of the other acid component and / or glycol component as the third component is about 50 mol% or less, preferably 30 mol% or less, more preferably 20 mol% or less, particularly preferably 10 mol% or less. And polytrimethylene terephthalate contained in
[0015]
Polytrimethylene terephthalate is produced by condensing terephthalic acid or a functional derivative thereof with trimethylene glycol or a functional derivative thereof in the presence of a catalyst under suitable reaction conditions. In this production process, a suitable one or two or more third components may be added to obtain a copolyester.
As the third component to be added, aliphatic dicarboxylic acids (oxalic acid, adipic acid, etc.), alicyclic dicarboxylic acids (cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acids (isophthalic acid, sodium sulfoisophthalic acid), aliphatic Glycols (ethylene glycol, 1,2-propylene glycol, tetramethylene glycol, etc.), alicyclic glycols (cyclohexane glycol, etc.), aromatic dioxy compounds (hydroquinone bisphenol A, etc.), aliphatic glycols containing aromatics (1 , 4-bis (β-hydroxyethoxy) benzene), aliphatic oxycarboxylic acids (p-oxybenzoic acid, etc.), and the like. In addition, a compound having one or three or more ester-forming functional groups (benzoic acid or the like or glycerin or the like) can be used as long as the polymer is substantially linear.
[0016]
Further, polytrimethylene terephthalate has a matting agent such as titanium dioxide, a stabilizer such as phosphoric acid, an ultraviolet absorber such as hydroxybenzophenone derivative, a crystallization nucleating agent such as talc, a lubricant such as aerosil, a hindered phenol. Antioxidants such as derivatives, flame retardants, antistatic agents, pigments, fluorescent brighteners, infrared absorbers, antifoaming agents, and the like may be included.
[0017]
The long fiber nonwoven fabric of the present invention can be obtained, for example, by the following method.
A number of continuous filaments obtained by melt spinning polytrimethylene terephthalate from a number of spinning nozzles are stretched by a traction device such as an ejector, and dispersed and deposited on a moving collection device to form a web, and then The nonwoven fabric of the present invention can be obtained by sheeting this web continuously by thermocompression bonding, columnar flow processing, or a combination of both.
[0018]
The spinning temperature at the time of melt spinning is suitably 230 to 320 ° C, preferably 235 to 300 ° C, more preferably 240 to 280 ° C. If the spinning temperature is less than 230 ° C., the temperature is too low to be in a stable molten state, the resulting fiber has large spots, and may not exhibit satisfactory strength. On the other hand, when the spinning temperature exceeds 320 ° C., the obtained yarn tends to be colored due to thermal decomposition and does not show satisfactory strength and elongation. There is no restriction | limiting in particular about the shape of the spinneret to be used, and a circular shape, a triangular shape, a polygonal shape, a flat shape or the like can be used, and it is usually a circular shape having a diameter of about 0.1 to 0.5 mm.
[0019]
Here, the ejector refers to an apparatus having a function of taking up and fine-pulverizing a melt-spun filament at high speed using a high-speed air flow by pressurized air as a driving force and causing the filament to accompany the high-speed air flow.
The speed of the filament extruded from the ejector, that is, the spinning speed is generally 2000 to 6000 m / min. The spinning speed is an index of the thinning of the filament single yarn, and the higher the speed, the finer the single yarn and the lower the fineness of the fiber. The spinning speed is mainly governed by conditions such as the discharge amount, the position of the ejector, and the pressure of the air fed in, but the preferred spinning speed range is 3500-5500 m / min. If it is less than 3500 m / min, it cannot be said that the tensile strength is necessarily sufficient because the filament is not sufficiently stretched, and the strength of the nonwoven fabric obtained from the filament tends to be low. If the spinning speed exceeds 5500 m / min, yarn breakage may occur during melt spinning, and the productivity of the nonwoven fabric tends to decrease.
[0020]
The group of filaments ejected together with the air flow from the outlet of the ejector, etc. is a movable porous receiver provided below, more specifically, a metal or resin mesh running at a constant speed It is collected as a web on etc. At this time, when the filaments ejected from the ejector or the like tend to harden and the spread of the collected web is narrow and the uniformity and quality as a sheet tend to be lacking, the filaments are particularly separated from each other. It is effective to devise such that it is ejected and collected in a state. For this purpose, for example, a collision member is provided below the ejector or the like, a filament is collided with the collision member, and the filament is triboelectrically charged and opened, or a corona discharge is performed below the ejector or the like. A method in which the filament is forcibly charged to open the filament can also be used.
[0021]
When collecting such webs, the accumulated web may be blown away and turbulent due to the air flow impinging on the receiver accompanying the filament group. To prevent this phenomenon, It is preferable to adopt means for sucking air from below the receiver.
The continuous fiber nonwoven fabric of the present invention can be obtained by continuously forming the web obtained as described above into a sheet by thermocompression bonding, columnar flow processing, or a combination of both.
[0022]
The thermocompression processing is preferably performed, for example, by pressing under heating at 80 to 240 ° C., and good press-bonding between fibers and heat stabilization treatment can be performed by the hot pressing. As a processing method, a heated flat plate can be used, but a method in which a web is pressed between a pair of heating rolls is excellent in productivity. The temperature and pressure of the treatment should be appropriately selected according to conditions such as the basis weight and speed of the web to be supplied, and there are some points that cannot be defined unconditionally, but a more preferable temperature is 180 to 240 ° C. and heating. When processing with a roller, the pressure is preferably at least a linear pressure of 10 kg / cm or more in order to stabilize the quality of the obtained long fiber nonwoven fabric. As the heating roller, it is also possible to use a plurality of rotating rollers having a smooth surface or a pattern engraved, a combination of these same types of rollers, or a combination of different types of rollers.
[0023]
The total area of the thermocompression bonding part is preferably 30% or less with respect to the total area of the nonwoven fabric, and more preferably in the range of 10 to 20%, so that the flexibility and bulkiness of the nonwoven fabric are satisfactorily exhibited. Preferred above.
Columnar flow processing is a method in which a high-speed fluid of liquid or gas is jetted onto a web and fibers are entangled and integrated three-dimensionally. The high-speed fluid has features such as ease of handling, cost, and magnitude of collision energy. Therefore, liquid is preferable, and water is most preferable.
[0024]
As a specific example, using a device in which injection holes having a hole diameter of 0.05 to 2 mm are arranged in one or a plurality of rows with an injection hole interval of 0.05 to 10 mm, liquid is supplied from the injection holes to 1.96 × 10 ^{3 to} 9. It is sprayed at a pressure of .81 × 10 ³ kPa [gauge] and collides with a web placed on a support. Conditions such as the pressure of the liquid, the number of rows of injection holes, the processing speed, the number of processings, etc. may be appropriately selected according to the use of the nonwoven fabric. As a support body, what is necessary is just for the structure which a high-speed fluid penetrates a web and a support body, for example, a mesh screen and a perforated board should just be used. By appropriately selecting the structure of the mesh screen, the size of the mesh, and the like, the surface form of the nonwoven fabric can be made smooth, and holes and patterns of various shapes can be provided.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited at all by these.
The measuring method is as follows.
(1) Intrinsic viscosity Intrinsic viscosity [η] is a ratio (ηsp / C) of specific viscosity ηsp and concentration C (g / 100 ml) using an Ostwald viscosity tube at 35 ° C. using o-chlorophenol. Extrapolated to zero concentration and determined according to the following formula.
[0026]
[Expression 1]

[0027]
(2) Tensile strength and stress at 5% elongation Measured according to JIS L-1906.
(3) Weight per unit area Measured by the method defined in JIS L-1906.
[ Reference Example 1]
Polytrimethylene terephthalate having an intrinsic viscosity [η] of 0.92 is melt-spun at 265 ° C., drawn at a spinning speed of 5000 m / min while being sucked by an ejector, and collected and deposited on a moving porous belt. A long fiber web was made.
[0028]
Fibers were entangled by spraying a columnar flow with a water pressure of 4.9 × 10 ³ kPa [gauge] from a large number of nozzles having a nozzle diameter of 0.15 mm, a nozzle pitch of 0.8 mm, and two rows. The distance between the nozzle and the long fiber web was 25 mm, and the web was supported by a stainless mesh screen moving at a speed of 16 m / min, and sucked and dehydrated through the mesh screen. The same treatment was applied to the other side of the sheet to obtain a long fiber nonwoven fabric having a basis weight of 50 g / m ² .
[0029]
The results of measuring the physical properties of the nonwoven fabric in the vertical direction are shown in Table 1.
[Example 2]
In Reference Example 1, a web was obtained in the same manner as in Reference Example 1 except that stretching was performed at a spinning speed of 3500 m / min. Next, columnar flow processing was performed in the same manner and conditions as in Reference Example 1 to obtain a long fiber nonwoven fabric having a basis weight of 50 g / m ² .
[0030]
The results of measuring the physical properties of the nonwoven fabric in the vertical direction are shown in Table 1.
[ Reference Example 3]
Polytrimethylene terephthalate having an intrinsic viscosity [η] of 0.66 is melt-spun at 270 ° C., drawn at a spinning speed of 4600 m / min while being sucked by an ejector, and collected and deposited on a moving porous strip. A long fiber web was made. Next, this web was subjected to thermocompression bonding with a pair of metal heating rolls to obtain a long fiber nonwoven fabric having a basis weight of 50 g / m ² . One of the heating rolls has an embossed pattern on the surface, and the other surface is flat.
[0031]
Table 2 shows the results of measuring the physical properties of the nonwoven fabric in the vertical direction.
In addition, as a comparison object, a polyethylene terephthalate long fiber nonwoven fabric (Asahi Kasei Kogyo “E01050” basis weight 50 g / m ² ) and a nylon 6 long fiber nonwoven fabric (Asahi Kasei Kogyo “N01050” basis weight 50 g / m ² ) vertical direction. The physical properties of are also shown in Table 2.
[0032]
[Comparative Example 1]
Nylon 6 polymer was melt spun at 265 ° C. with the exception that the stretching at a spinning speed of 4500 m / min, to create a web in the same manner as in Reference Example 1, in the same manner as in Reference Example 1, water pressure 3.9 × 10 ^A columnar flow process was performed at ³ kPa [gauge] to obtain a long fiber nonwoven fabric having a basis weight of 50 g / m ² .
The physical properties of the nonwoven fabric in the vertical direction were measured. The results are shown in Table 1.
[0033]
[Comparative Example 2]
The intrinsic viscosity [eta] is melt spun at 300 ° C. using a polyethylene terephthalate 0.71, except that the stretching at a spinning speed of 4400 m / min, to create a web in the same manner as in Reference Example 1, Reference Example 1 Similarly, columnar flow processing was performed at a water pressure of 4.9 × 10 ³ kPa [gauge] to obtain a long fiber nonwoven fabric having a basis weight of 50 g / m ² .
[0034]
The results of measuring the physical properties of the nonwoven fabric in the vertical direction are shown in Table 1.
[0035]
[Table 1]

[0036]
[Table 2]

[0037]
【The invention's effect】
The non-woven fabric of the present invention is a long-fiber non-woven fabric having a low modulus, high elongation, and excellent moldability, and is useful for skin cloth applications and the like by taking advantage of its characteristics.

Claims (2)

A method for producing a long-fiber nonwoven fabric, comprising the following steps:
Polytrimethylene terephthalate having an intrinsic viscosity [η] of 0.4 to 2.0 is melt-spun,
Stretching at a spinning speed of 2000 to 3500 m / min while sucking with an ejector, collecting and depositing on a moving porous strip to obtain a long fiber web, and
A columnar flow is jetted onto the long fiber webs so as to be entangled, and the breaking elongation in the vertical direction is in the range of 130 to 250%, and the stress at 5% elongation is in the range of 0.5 to 2 N / 3 cm. To obtain a long fiber nonwoven fabric,
Including said method. The long-fiber nonwoven fabric manufactured by the method of Claim 1.