JPS6411457B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a stretchable laminated fiber structure having flexibility and breathability. Conventionally, nets made of elastic material in stretchable knitted fabrics,
Stretchable fiber structures made of laminated films, sheets, or foam sheets are known. These materials are used in a wide range of fields as materials for clothing, medical materials, and interior materials that require stretch properties.
Such a laminated fiber structure is highly bulky, and has properties such as thickness, texture, and heat retention that cannot be obtained by using a fabric made by mixing and weaving polyurethane elastic yarns alone. However, these known stretchable laminate structures each have their own characteristics and limitations in performance. That is,
Although the laminate of polyurethane net and stretchable fabric made by molding has breathability and stretchability,
Since the number of meshes in the net cannot be made small, it is difficult to make the surface layer smooth, and it is inevitable that the surface layer will be poor in flexibility. Furthermore, structures in which a polyurethane film is laminated on a base fabric using a wet method or a transfer method are waterproof, but have poor breathability and flexibility (see, for example, Japanese Patent Publication No. 32338/1983). . Furthermore, a structure in which a polyurethane foam or a synthetic rubber foam is laminated on a base fabric can provide a sufficiently thick feeling, but the air permeability is lost. When the foam is sliced and used, breathability can be obtained, but the elasticity is inferior. Furthermore, sheets of elastic material such as rubber and knitted fabrics do not provide breathability or flexibility. As described above, each of the conventionally known elastic fiber structures has features and limitations in performance, and is used in a manner that takes advantage of each feature. An object of the present invention is to provide a laminated fiber structure that is lightweight, thick, has a soft feel, and has excellent elasticity and breathability. The present invention provides a polyurethane elastic fiber nonwoven fabric in which melt-spun polyurethane elastic filaments are laminated without substantially converging, and the contact points of the laminated filaments are joined by the filaments themselves; The growth rate
A stretchable laminated fiber structure having flexibility and breathability, which is made by laminating and bonding two or more layers of 10% or more of knitted fabric. As the polyurethane elastic body constituting the nonwoven fabric applied to the present invention, a known melt-spuntable thermoplastic polyurethane elastic body is used. Such polyurethane elastomers usually contain a low melting point polyol with a molecular weight of 500 to 6000, such as dihydroxy polyether, dihydroxy polyester, dihydroxy polycarbonate, dihydroxy polyester amide, etc., and an organic diisocyanate with a molecular weight of 500 or less, such as p,p'-diphenylmethane. diisocyanate, tolylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, 2,6-diisocyanate methyl caproate, hexamethylene diisocyanate, etc., and a chain extender with a molecular weight of 500 or less, such as glycol, amino alcohol or is a polymer obtained by reaction with a triol. Among these polymers, particularly good are polytetramethylene glycol, polyurethane using polyε-caprolactone or polybutylene adipate as the polyol. Further, as the organic diisocyanate, p,p'-diphenylmethane diisocyanate is suitable. In addition, as a chain extender, 1,4-
Bishydroxyethoxybenzene and 1,4-
Butanediol is preferred. The polyurethane elastomer is synthesized from a polyol, an organic diisocyanate, and a chain extender as described above, but polyurethane elastomers are preferably used in the present invention when the polyol component accounts for 65% or more of the total weight, and in particular A preferable content is 68% by weight or more; if the content of the polyol component is low, the elongation and elongation modulus of the resulting nonwoven fabric will be low. These polyurethane elastomers may contain plasticizers, pigments, stabilizers, and the like. The nonwoven fabric used in the present invention uses the thermoplastic polyurethane elastomer described above as the polymer, but more preferably, a polyisocyanate compound is added to the molten polyurethane elastomer, kneaded, and then discharged from a spinning nozzle. good. The nonwoven fabric used in the present invention is a fabric in which polyurethane elastic filaments are spread and laminated over substantially the entire length of the yarn without convergence. If the monofilaments are joined in a bundled state without being opened, the flexibility of the nonwoven fabric will be significantly impaired. Also, the diameter of this monofilament is usually average
It is less than 50 microns, preferably less than 30 microns on average, particularly preferably less than 20 microns. The diameter of the monofilament may vary, but the maximum diameter is preferably 70 microns or less. As the fiber diameter of the monofilament increases, the nonwoven fabric becomes rough and rigid. The nonwoven fabric applied to the present invention is one in which polyurethane elastic filaments are laminated, and the contact points between the fibers constituting this laminate are joined by the fibers themselves, preferably at least half of the contact points, particularly preferably at least 80%, Most preferably, it is approximately 100% bonded. Such a bonded state can be achieved by thermally fusing the polyurethane elastic fibers together. Methods using solvents or other adhesives are not preferred because they reduce the air permeability and flexibility of the nonwoven fabric. However, an adhesive may be used in combination without impairing these properties. One of the important features of the nonwoven fabric applied to the present invention is that the nonwoven fabric has extremely high breaking strength and elongation, and has excellent elastic performance. This is because the performance of the polyurethane elastic fibers constituting the nonwoven fabric is directly reflected. This is a performance that cannot be obtained with polyurethane or synthetic rubber foam sheets. The elongation at break of the nonwoven fabric applied to the present invention is usually 300% or more, preferably 500%.
That's all. The breaking strength varies depending on the thickness of the nonwoven fabric, but is usually 0.4 kg/cm, preferably
It is 1.0Kg/cm or more. Further, the 100% elongation elastic modulus is usually 85% or more, preferably 90% or more. The strength, elongation, and elongation modulus of a nonwoven fabric vary depending on the adhesive strength of the contact points between the fibers that make up the nonwoven fabric. The percentage indicates that the contact points are sufficiently bonded. The greatest feature of the nonwoven fabric used in the present invention is that it is extremely flexible. Bending resistance of non-woven fabric (JIS
L-1096 (45 degree cantilever method) increases as the basis weight of the nonwoven fabric increases, but the nonwoven fabric used in the present invention has a basis weight of X (g/m ² ) and bending resistance of y (mm). Then, y<0.2X+30, and more preferably y<0.2X+20. This feature is obtained by combining the physical properties of the polyurethane elastic body with the above-mentioned structure of the nonwoven fabric and the small diameter of the constituent fibers. This was something that could not be achieved with polyurethane nets or sheets manufactured by the method. The knitted fabric applied to the present invention has an elongation rate in at least one direction of 10% or more, preferably 20% or more. When the elongation rate is small, the elongation of the desired laminated structure becomes small. In the present invention, the elongation rate refers to the elongation rate when a 1.5 kg load is applied to a sample with a width of 5 cm and the sample is left for 1 minute. As the structure of the knitted fabric applied to the present invention, either knitted fabric or woven fabric can be used, but warp knitted fabric and weft knitted fabric are suitable because of their high elongation. A stretch knitted fabric in which elastic yarns are mixed is more suitable. In the case of woven fabrics, stretch woven fabrics using elastic yarns for the warp or weft are particularly suitable. In addition, the fibers that make up knitted fabrics include nylon, acrylic, polyester, polypropylene,
Alternatively, chemical fibers such as rayon and acetate, natural fibers such as cotton, linen, wool, silk, and combinations thereof are preferably used. Examples of such knitted fabrics include two-way tricot fabrics made of nylon and urethane yarns, circular knitted fabrics made of interknitted cotton and urethane yarns, and wool stretch fabrics. In addition, raised fabrics subjected to raised processing, flocked fabrics subjected to flocking processing, terry cloth, terry cloth, etc. are particularly suitable from the viewpoint of surface texture and feel. The special shape of the knitted fabric applicable to the present invention includes a fabric which itself has a small elongation rate and is folded into a jagged shape. Such a shape can be obtained, for example, by laminating a stretched polyurethane nonwoven fabric and a knitted fabric, joining them together, and then allowing the nonwoven fabric to recover. The structure of the present invention is made by laminating and bonding the above-described polyurethane elastic fiber nonwoven fabric and knitted fabric, and the number of layers is two or more, particularly three layers in which knitted fabric is laminated on both sides of the polyurethane elastic fiber nonwoven fabric. The structure is suitable. The structure of the present invention can be manufactured by bonding a polyurethane elastic fiber nonwoven fabric and a knitted fabric using, for example, an adhesive. The adhesive may be emulsion type, as long as it does not dissolve or swell the polyurethane nonwoven fabric.
Either solution type can be used. Although there are no particular restrictions on the type of adhesive, polyurethane-based adhesives, acrylic ester-based adhesives, synthetic rubber-based adhesives, etc., which have elasticity themselves, are particularly suitable. The emulsion or solution of these adhesives may be applied as is, but a laminated structure obtained by using the so-called foam coating method, in which fine bubbles are formed using an appropriate whipper or stirrer before being applied, can be used. The air permeability, flexibility, and stretchability are even better, which is preferable. Further, a wet or powdered hot melt adhesive may be used as the adhesive. As another method for producing the laminated structure of the present invention, a method in which the joining is performed by thermal fusing of the polyurethane elastic fibers themselves is also suitable. For example, devices such as a thermal adhesive laminating machine, a high frequency welder, or an ultrasonic sewing machine can be suitably used. In this case, it is also possible to use the above-mentioned adhesives or hot melt adhesives together. Another suitable method for producing the laminated structure of the present invention is a method in which a polyurethane elastic fiber nonwoven fabric and a knitted fabric are laminated and joined by quilting. In this case, the elongation of the laminated structure can be improved by making the seams zigzag or wavy, using elastic thread such as polypivalolactone fiber, or using a sewing machine that produces seams with high elongation. It is best to prevent this from decreasing. One of the advantages of the present invention is that the strength of the elastic nonwoven fabric does not decrease even when joined by quilting in this way, which could not be achieved with elastic films, sheets, or foams. One of the important properties of the structure of the present invention is its excellent elastic performance. The elongation rate of the structure is limited by the elongation rate of the laminated knitted fabrics, but 10
% or more, and not only 40 to 60%, which is suitable for casual clothing and sports clothing, but also 100 to 200%, which is used for stretch tapes, etc., can be easily obtained. In addition, after being stretched under tension, it recovers extremely quickly and has a high recovery rate when the tension is removed.For example, the instantaneous recovery rate when stretched by 10% is
More than 90%. Another feature of the structure of the present invention is that it is extremely flexible. This flexibility is achieved due to the high flexibility of the polyurethane elastic fiber nonwoven fabric constituting the present invention, and cannot be obtained by laminating it with known elastic nets, films, foam sheets, etc. It's about performance. This flexibility provides an extremely soft feel suitable for clothing applications. Further, the structure of the present invention has air permeability and moisture permeability, and is suitable for use in clothing, medical use, or sanitary materials. The present invention will be explained below with reference to Examples. Note that various physical properties were measured by the following methods.
Breaking strength and elongation: JIS L
According to 1096, grip interval is 5cm, pulling speed is 10cm/
Stretch as min, and measure the strength and elongation per 1 cm width at break. Elongation rate: According to the constant load method for stretch fabrics of JIS L 1096, a load of 1.5 kg was applied to a sample with a width of 5 cm.
Measure the elongation rate after standing for a minute. Elongation elastic modulus: A sample with a width of 2 cm is grasped at a distance of 5 cm, and a tensile speed of 10 cm/min is stretched to a constant elongation, then immediately recovered to the original length at the same speed, the residual elongation is determined from the recorded load-elongation curve, and the elongation elasticity is calculated using the following formula. Calculate the rate. Elongation modulus (%) = L - L ₁ /L x 100 where L: constant elongation (mm), L ₁ : residual elongation (mm) bending resistance: according to the 45° cantilever method of JIS L 1096. Air permeability: JIS L 1096 Frazier type tester was used. Example 1 Polybutylene adibate with a molecular weight of 1500, p,
A thermoplastic polyurethane elastomer synthesized from p'-diphenylmethane diisocyanate and 1,4-butanediol is melted, and a polyurethane resin synthesized from polybutylene adipate with a molecular weight of 1000 and twice the mole of p,p'-diphenylmethane diisocyanate is The first performance was obtained when 10% by weight of an isocyanate compound was added and kneaded, then discharged from the spinneret of a melt blow spinning device and heat treated at 100°C for 3 hours after spinning.
A nonwoven fabric as shown in the table was obtained.

[Table] In each case, monofilaments of polyurethane elastic fibers were opened and stacked, and the intertwining points between the filaments were joined to each other by fusion. The air permeability was extremely high in all cases, exceeding 400 cm ³ /cm ² /sec. The elongation rate in the horizontal direction on both sides of No. 1-1 nonwoven fabric is 95
%, cotton knitted fabric with a basis weight of 137 g/m ² was thermally bonded using a thermal bonding laminating machine at 200° C. and at a linear pressure of 20 kg/cm at a speed of 10 m/min. The elongation rate of this laminated structure in the horizontal direction was 80%, making it suitable as a foundation material. In addition, it has a laminated structure in which the front side of the nonwoven fabric in 1-2 is made of nylon tricot with an elongation rate of 42% vertically and 100% horizontally, and the back side is made of cotton knitted fabric with an elongation rate of 45% vertically and 165% horizontally bonded using an acrylic adhesive. The material was 33% vertically and 78% horizontally, making it suitable as a material for sports jackets. In addition, the laminated structure in which 1-3 non-woven fabric is laminated with 100% cotton pile knit on the surface and cotton knitted fabric with 95% elongation on the back has an elongation rate of 68% and air permeability of 45cm ³ /cm ² /sec, making it healthy. It was suitable as a material for a belly band. Example 2 p,p'-diphenylmethane diisocyanate,
Polytetramethylene glycol with a molecular weight of 1000,
Made from polyurethane elastic pellets made of 1,4-butanediol, arranged in a row with a diameter
The melting temperature was determined using a melt blow spinning device with a 0.8 mm nozzle and slits for injection of heated gas on both sides.
The polymer was discharged at 245° C. at a rate of 0.5 g per minute per nozzle, and air heated to 200° C. was injected through the slit at a pressure of 3.5 kg/cm ² to atomize the polymer. The fine filament was collected on a conveyor consisting of a 30-mesh wire mesh placed 25 cm below the nozzle, and then sandwiched between rollers to obtain a nonwoven fabric. This nonwoven fabric was made up of opened and laminated monofilaments of polyurethane elastic fibers, and the intertwining points between the filaments were joined together by fusion. The physical properties of this nonwoven fabric were as follows. Weight: 86.2g/ ^m2 Tensile strength: 0.790Kg/cm Elongation at break: 730% 100% elongation recovery rate: 92% Bending resistance: 31mm Filament diameter: 20 microns Air permeability: 400cm ³ /cm ² /sec or more Next, made of nylon and spandex Two-way tricot (horizontal elongation rate 128%, basis weight)
291g/m ² ) on the front side of the above nonwoven fabric.
133 g/m ² ) was attached to the back side of the above nonwoven fabric to form three layers. When laminating these, they were laminated using an acrylic adhesive (trade name: Yodozol A-4540, manufactured by Kanebo NSC Co., Ltd.) using a form coating method. The physical properties of the laminated structure obtained by heat treatment at 100°C for 5 minutes and 130°C for 3 minutes were as follows. Weight: 499 g/ ^m2 Elongation: 55% 50% elongation modulus: 90% Bending resistance: 48 mm Air permeability: 55 cm ³ /cm ² /sec The laminate thus obtained has a high elongation rate and a high recovery rate. It was highly flexible and had excellent breathability. When this product was applied to a wetsuit, it showed excellent elasticity and stability against repeated deformation, and had excellent conformability to the human body when worn.

Claims (1)

[Scope of Claims] 1. A polyurethane elastic fiber nonwoven fabric in which melt-spun polyurethane elastic filaments are laminated without substantially convergence, and the mutual contact points of the laminated filaments are joined by the filaments themselves; A stretchable laminated fiber structure having flexibility and breathability, which is obtained by laminating and bonding two or more layers of a knitted fabric with an elongation rate of at least 10% or more in one direction. 2. The structure according to claim 1, wherein the polyurethane elastomer filaments have an average diameter of 50 microns or less. 3 The bending resistance y of polyurethane elastic fiber nonwoven fabric is expressed by the general formula y<0.2X+30 [where y is bending resistance (mm) and X is basis weight (g/ ^m2 )
The structure according to claim 1, which is within the range represented by [representing]. 4. The structure according to claim 1, wherein the polyurethane elastic fiber nonwoven fabric has a 100% elongation modulus of 90% or more. 5. The structure according to claim 1, wherein the elongation rate of the knitted fabric in at least one direction is 20% or more. 6. The structure according to claim 1, wherein the knitted fabric is a warp knitted fabric or a weft knitted fabric. 7. The structure according to claim 1, wherein the knitted fabric is a raised fabric. 8. The structure according to claim 1, wherein the knitted fabric is made by inter-knitting or inter-weaving elastic yarns. 9. The structure according to claim 1, wherein a knitted fabric is laminated on both sides of a polyurethane elastic fiber nonwoven fabric.