JP3101414B2 - Stretchable polyester-based elastic nonwoven fabric and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretchable non-woven fabric comprising a copolyester-based elastic conjugate fiber, and can be used as a pulp material, an interlining, a supporter, a stretch tape and the like. More specifically, an elastic polyester having extensibility, because the polymer itself exhibits tackiness, sticks (blocks) between filaments at the time of forming a filament, and has poor openability. An object of the present invention is to provide a polyester elastic nonwoven fabric having improved elasticity and a production method.

[0002]

2. Description of the Related Art Polyurethane is known as a typical example of a polymer called spandex, but it has drawbacks in heat resistance, light resistance, or wet heat resistance.
There is a problem that the cost is high. For this reason, polyester-based elastic polymers have been developed, and as disclosed in JP-A-56-118911, polybutylene terephthalate (hereinafter referred to as PBT) has been developed.
Polymers having a main component of a polytetramethylene glycol (hereinafter abbreviated to PTMG) as a main component are well known. For the purpose of forming a non-woven fabric using such a polymer, for example, Japanese Patent Application Laid-Open No. 57-82552 discloses a non-woven fabric by a needle punch method and a method thereof. It is not suitable for a method of producing a nonwoven fabric having a small basis weight, and has the problem that other cloths, papers, etc. must be used on one or both sides of the web or sheet during needle punching. Japanese Patent Application Laid-Open No. 57-82553 and Japanese Patent Application Laid-Open No. Hei 3-8855 also describe a method for producing a nonwoven fabric, which is presumed to be due to the tackiness of the polymer. The following are appropriate in terms of the spreadability, and there is a problem in productivity.

[0003]

Conventionally, a copolymer component having a high PTMG content ratio has poor filament opening due to fusion between filaments, so-called blocking, since filaments have tackiness in the spinning process. However, the elastic properties of the resulting nonwoven fabric are excellent. Further, a copolymer component having a small PTMG content ratio has a problem that the nonwoven fabric obtained has good elasticity, but the elasticity of the obtained nonwoven fabric is poor because the occurrence of blocking is small.

The present invention solves the above-mentioned problems. That is, the copolymer component having a high PTMG content ratio is
An object of the present invention is to provide a nonwoven fabric having good sheet formation and elastic properties and a method for producing the same by positioning both components in a core-sheath composite of a sheath with a copolymer component having a low MG ratio.

[0005]

Means for Solving the Problems The present inventors have made intensive studies in order to solve such problems, and have reached the present invention.

That is, the present invention relates to a copolymerized polyester elastomer comprising a polyester having polybutylene terephthalate as a main component and a polyether having polytetramethylene glycol as a main component.
-20% by weight and a polyether component of 51-80% by weight with a high polyether content ratio as a core component, a polyester component of 90-51% by weight, and a polyether component of 1%.
A stretchable polyester-based elastic non-woven fabric comprising a core-sheath composite long fiber in which a component having a low polyether content ratio of 0 to 49% by weight is arranged in a sheath component.

The fineness of the single yarn constituting the nonwoven fabric is 2 to 12 denier, the temperature is 5 to 30 ° C. lower than the melting point of the sheath component of the conjugate fiber determined by DSC, and the area of pressed area is 4 to 40. 2. The method for producing a polyester-based elastic nonwoven fabric according to claim 1, wherein the nonwoven fabric is partially thermocompression-bonded with an embossing roll having a percentage of 100%.

Hereinafter, the present invention will be described in detail. The polyester elastomer referred to in the present invention is disclosed in
-118911, which is a copolymer composed of a polyester whose main component is PBT and a polyether whose main component is PTMG. The polyester component is mainly composed of terephthalic acid as a dicarboxylic acid component, and PBT composed of butanediol as a diol component. Other copolymer components include, for example, polyethylene terephthalate, polyethylene isophthalate, polybutylene isophthalate, and polybutylene. Adipate or the like may be copolymerized, for example, in an amount of about 10 polymerized parts as long as spinnability and elasticity are not impaired.

On the other hand, the main component of the polyether component is PTMG made of tetramethylene glycol, and the number average molecular weight is 1000 to 30 from the viewpoint of spinnability and elasticity.
00 is preferred. In addition, ethylene glycol, diethylene glycol, trimethylene glycol or the like may be copolymerized.

[0010] In addition, the above-mentioned two components may include optional additives such as a matting agent, a pigment, a flame retardant, a deodorant, an antistatic agent, an antioxidant, and an ultraviolet absorber as long as the object of the present invention is not impaired. Additives can be added.

The polyester-based elastomer referred to in the present invention is a copolymerized polyester / polyether composed of the above, and the copolymerization ratio applied to the core component is 49 to 20% by weight for the polyester component and 51 to 51% for the polyether component.
Must be 80% by weight. That is, when the polyester component is 50% by weight or more, excellent mechanical properties are exhibited, but the elastic recovery rate is inferior. On the contrary, when the polyester component is 19% by weight or less, poor penetration of the component by a melt extruder. In addition, the yarn is cut in the yarn-making process, and the intended nonwoven fabric cannot be obtained outside the scope of the present invention.

The copolymerization ratio applied to the core component is 90-51% by weight for the polyester component and 10% for the polyether component.
Should be ~ 49% by weight. That is, if the polyester component is 90% by weight or more, since the elasticity of the core component is too different from that of the core component, even if the core-sheath composite cross section is slightly eccentric, a loop-like thread is generated on the surface of the nonwoven fabric and the quality is low. Inferior and inferior in elastic properties.

On the other hand, if the content is 50% by weight or less, the object is not the object of the present invention because blocking occurs in the form of a thread and the spreadability is poor. Further, an advantageous range of the copolymerization ratio of both components is as follows.

Core component = polyester: polyether = 4
0 to 25% by weight: 60 to 75% by weight, sheath component = polyester: polyether = 80 to 60% by weight: 20 to 40% by weight, and the polymerized polyester / polyether is 1/1 of ethane tetrachloride / phenol. The relative viscosity measured at a temperature of 20 ° C by weight ratio is preferably 1.3 to 3.0.

For comparison, when both components of the present invention are subjected to melt spinning of each component alone instead of the core-sheath composite spinning, the following problems are encountered. That is, when the core component is spun alone,
Because the filaments are sticky, for example, in the spinning method, the filaments are fused to each other in the jet, and in the subsequent opening step, there is a problem that the fiber is not opened at all. Has poor mechanical performance. On the other hand, if the sheath component is spun alone, sufficient elastic properties cannot be obtained because the amount of PTMG is too small.

For this reason, the copolyester / polyether component having a low PTMG content ratio as in the present invention is used as a sheath component and the PTMG content ratio is high, that is, a copolyester / polyether component having excellent elastic properties. By arranging in the core component, a nonwoven fabric having excellent spreadability and elastic properties can be obtained.

In the core-sheath composite long fiber of the present invention, when the composite ratio of the copolymerized polyester / ether having a large PTMG content ratio as the core component is increased, a nonwoven fabric having more excellent elastic properties can be obtained. On the other hand, PTM which is a sheath component
When the composite ratio of the copolyester / ether having a small G ratio is increased, a nonwoven fabric having excellent mechanical properties can be obtained, although the elastic properties are slightly inferior.

The composite ratio should be determined according to the required performance of the nonwoven fabric, but the core / sheath = 1/3 to 3/1 is a preferable range.

The core-sheath composite continuous single yarn used in the present invention is obtained by melt-spinning two polymers having different PTMG amounts by a conventionally known melt composite spinning machine. It is melted at a temperature 15 to 80 ° C. higher than the melting point of the polyester elastomer of the sheath component having a high melting point, discharged from the spinneret, and cooled using a conventionally known cooling device. Then, set the target fineness to 20
It is towed at a speed of not less than 00 m / min and not more than 4000 m / min. This accelerates and orients the elastic fibers with high velocity airflow. If the drawing speed exceeds 4000 m / min, the thread-like cutting or orientation becomes too high, and the elastic recovery of the obtained fiber is impaired. Then the obtained filament is
The fiber is uniformly spread through a fiber opening machine, collected in a sheet shape by a net conveyor, and formed into a fiber web having a predetermined thickness and a filament arrangement.

Thereafter, the fibrous web is partially thermocompression-bonded between the constituent filaments with a heated embossing roller. The temperature of the embossing roller is most affected by the copolymerization composition of the polyester elastomer used, but is 5 to 5 degrees below the melting point of the polyester elastomer which is a component having a small PTMG content ratio as a sheath component.
It should be pressed at a temperature lower than 30 ° C. If the temperature is lower than 5 ° C., the temperature is too high, so that the nonwoven fabric is liable to adhere to the embossing roller, the workability is poor, and the flexibility of the obtained nonwoven fabric is significantly impaired. 30 ° C
When the above is not satisfied, the non-woven fabric is not subjected to sufficient thermocompression bonding, so that the shape retention is poor, fuzzing of the non-woven fabric surface is likely to occur, and the mechanical properties are poor.

The pressing area ratio of the embossing roll is 4 to 4
Should be thermocompressed at 0%. If it is less than 4%, the thermocompression bonding portion is too small with respect to the nonwoven fabric, resulting in poor shape retention, surface fluffing property, and mechanical performance. On the other hand, if it exceeds 40%, the length at which the elastic fiber freely expands and contracts becomes shorter, and the result is inferior flexibility.

The elastic polyester-based nonwoven fabric having elasticity can be obtained by the above method. The shape, number and basis weight of the filaments forming the fibrous web are not particularly limited. Should be denier. If it is less than 2 deniers, not only is the productivity inferior, but also too small, the elastic stress is insufficient, and the desired elastic nonwoven fabric cannot be obtained. On the other hand, when the denier is 12 denier or more, the coarse and hard feeling becomes large and a nonwoven fabric of good quality cannot be obtained. 50% of elastic polyester nonwoven fabric having such elasticity
It shows a value of 25% or more as an instantaneous elastic recovery rate at the time of stretching, and has not only elasticity but also drapability, and also has excellent heat resistance and wet heat resistance.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to this method.

FIG. 1 is a process diagram illustrating an embodiment of the method for producing a nonwoven fabric of the present invention. The spinning apparatus has individual melt-extrusion of component A and component B, and measuring units 1 and 2. The weighed components are combined in a die 3 and spun as a set 4 of many monofilaments. At this time, the die discharge hole has both components as illustrated in FIGS.
It is arranged in a core-sheath structure. Even if the core portion is eccentric as shown in FIG. 3, there is no problem.

After being cooled by the cooling device 5, the discharged monofilament aggregate 4 is taken up as a core-sheath composite yarn by a take-up means consisting of a jet 6, and then passed through a corona discharge opening device 7 in a high piezoelectric field. The web 9 is spread on a moving deposition device 8 composed of a screen. The web 9 is partially thermocompression-bonded by a hot embossing roll 10 and wound up as a nonwoven fabric 11.

[0026]

The present invention will be described in detail with reference to examples, but the present invention is not limited by these examples. In the examples, the measurement method and measurement conditions for each item are as follows.

(1) Strength of nonwoven fabric Tensilon TM-4-1-1 manufactured by Toyo Baldwin Co., Ltd.
According to the method described in JIS-L-1096A, a sample length of 10 cm, a width of 5 cm, and a tensile speed of 10 cm /
Measured in minutes.

(2) Elongation of nonwoven fabric Same as the method described in (1).

(3) Elastic recovery rate of nonwoven fabric The recovery rate at 50% elongation was determined on a sample piece of 10 cm in length and 5 cm in width under the condition of a tensile speed of 10 cm / min.

(4) Melting Point of Polymer The temperature at which the maximum value of the melting endothermic peak measured at a heating rate of 20 ° C./min using a DSC-2 type differential scanning calorimeter manufactured by Perkin Elmer Co., Ltd. was defined as the melting point.

[0031]

Example 1 The melting point obtained by DSC was 208.
° C, PT with relative viscosity 1.92, number average molecular weight 1500
When the copolymerization ratio of MG and PBT is PTMG / PBT = 40 /
60 copolymerized polyester-based elastomer as the sheath component,
Melting point: 187 ° C, relative viscosity: 2.07, number average molecular weight: 1
PTMG / PBT copolymerization ratio of 500 is PTMG / P
A copolymer polyester elastomer having BT = 57/43 was used as a core component, the composite ratio of the sheath component and the core component was set to 1: 1, the melting temperature of the sheath component was 255 ° C., and the melting temperature of the core component was 23.
It was melt-extruded at 5 ° C. at a single hole discharge rate of 1.5 g / min.

Under these conditions, the yarn is spun from a spinneret having a hole diameter of 0.5φ, a number of core-sheath composite yarns are cooled by a cooling device, and then 3,000 m / m2 is jetted by a plurality of jets arranged at a position 190 cm below the spinneret. The web was taken up at a speed of one minute, spread by a corona discharge spreader, and deposited by a moving wire mesh deposition device to form a web. At this time, the single yarn denier was 4.5 d. Then, it was partially thermocompression-bonded with a hot embossing roll having a press contact area ratio of 12%, a point pattern and a surface temperature of 175 ° C. to obtain a stretchable elastic nonwoven fabric.

The properties of the obtained stretchable elastic nonwoven fabric are shown in Table 1. As a result, a nonwoven fabric having good spreadability, good sheet formation and excellent elastic properties was obtained.

[0034]

[Table 1] <Operability> Adhesiveness: None Spreadability: Good <Non-woven fabric performance> Weight: 80 (g / m ² ) Longitudinal tensile strength: 8.8 (kg / 5cm) Longitudinal tensile elongation: 121 (%) Elastic recovery rate: 34 (%)

[0035]

Example 2 The melting point obtained by DSC was 220.
° C, relative viscosity 1.90, number average molecular weight 1500 PT
When the copolymerization ratio of MG and PBT is PTMG / PBT = 20 /
80 copolyester elastomer as sheath component,
Melting point: 187 ° C, relative viscosity: 2.07, number average molecular weight: 1
PTMG / PBT copolymerization ratio of 500 is PTMG / P
A copolymer polyester elastomer having BT = 57/43 was used as a core component, the composite ratio of the sheath component and the core component was set to 1: 1, the melting temperature of the sheath component was 265 ° C., and the melting temperature of the core component was 23.
It was melt-extruded at 5 ° C. at a single hole discharge rate of 1.5 g / min.

Under these conditions, the yarn is spun from a spinneret having a hole diameter of 0.5φ, and a large number of core-sheath composite yarns are cooled by a cooling device. The web was taken up at a speed of 1 minute, spread by a corona discharge spreader, and deposited on a moving wire mesh deposition device to form a web. At this time, the single yarn denier was 4.2 d. Then, the pressure contact area ratio is 12%, the point pattern, the surface temperature is 190 ° C.
An elastic elastic nonwoven fabric was obtained.

The properties of the obtained stretchable elastic nonwoven fabric are shown in Table 2. By improving the spreadability, a stretchable elastic nonwoven fabric having better sheet formation was obtained.

[0038]

[Table 2] Table 2 <Operability> Adhesiveness: None Spreadability: Very good <Non-woven fabric performance> Weight: 83 (g / m ² ) Tensile tensile strength: 9.1 (kg / 5cm) Longitudinal tensile elongation Degree: 104 (%) Elastic recovery rate: 30 (%)

[0039]

Example 3 Using the same polymer as in Example 1, the composite ratio of the sheath component and the core component was set to sheath / core = 1/2, and the mixture was melt-extruded at the same melting temperature and single hole discharge amount as in Example 1.

Under these conditions, spinning is performed from a spinneret having a hole diameter of 0.5φ, and a large number of core-sheath composite yarns are cooled by a cooling device. The web was taken up at a speed of one minute, spread by a corona discharge spreader, and deposited by a moving wire mesh deposition device to form a web. At this time, the single yarn denier was 4.7 d. Then, it was partially thermocompression-bonded with a hot embossing roll having a pressed area ratio of 12%, a point pattern, and a surface temperature of 190 ° C. to obtain a stretchable elastic nonwoven fabric.

The properties of the obtained elastic elastic nonwoven fabric are shown in Table 3, and a nonwoven fabric having excellent elastic properties was obtained.

[0042]

[Table 3] Table 3 <Operability> Adhesiveness: None Spreadability: Good <Non-woven fabric performance> Weight: 80 (g / m ² ) Longitudinal tensile strength: 8.5 (kg / 5cm) Longitudinal tensile elongation: 131 (%) Elastic recovery rate: 38 (%)

[0043]

Example 4 Using the same polymer as in Example 1, the composite ratio of the sheath component and the core component was set to sheath / core = 2/1, and the mixture was melt-extruded at the same melting temperature and single hole discharge rate as in Example 1.

Under these conditions, the yarn is spun from a spinneret having a hole diameter of 0.5 φ, a number of core-sheath composite yarns are cooled by a cooling device, and then 3100 m / h by a plurality of jets arranged 180 cm below the spinneret. The web was taken up at a speed of one minute, spread by a corona discharge spreader, and deposited by a moving wire mesh deposition device to form a web. At this time, the single yarn denier was 4.4d. Then, it was partially thermocompression-bonded with a hot embossing roll having a pressed area ratio of 12%, a point pattern, and a surface temperature of 190 ° C. to obtain a stretchable elastic nonwoven fabric.

The properties of the obtained stretchable elastic nonwoven fabric are shown in Table 4. The nonwoven fabric having good sheet formation and excellent mechanical properties was obtained.

[0046]

Table 4 <Operability> Adhesiveness: None Opening property: Good <Non-woven fabric performance> Weight: 82 (g / m ² ) Longitudinal tensile strength: 9.3 (kg / 5cm) Longitudinal tensile elongation: 112 (%) Elastic recovery: 31 (%)

[0047]

Comparative Example 1 The melting point obtained by DSC was 226.
° C, PT with relative viscosity 1.88, number average molecular weight 1500
When the copolymerization ratio of MG and PBT is PTMG / PBT = 5/9
5, a melting point of 187 ° C., a relative viscosity of 2.07, and a number average molecular weight of 15
00 PTMG and PBT copolymerization ratio is PTMG / PB
Using a copolyester elastomer having a T = 57/43 as a core component, a composite ratio of a sheath component and a core component is set to 1: 1,
Melting temperature of sheath component 275 ° C, melting temperature of core component 235
And extruded at 1.5 g / min.

Under these conditions, spinning is performed from a spinneret having a hole diameter of 0.5φ, a number of core-sheath composite yarns are cooled by a cooling device, and then 3530 m / h is formed by a plurality of jets arranged at a position 190 cm below the spinneret. The web was taken up at a speed of one minute, spread by a corona discharge spreader, and deposited by a moving wire mesh deposition device to form a web. At this time, single yarn denier is 3.8d
Met. Then, the pressure contact area ratio is 12%, point pattern,
Partial thermocompression bonding was performed with a hot embossing roll having a surface temperature of 195 ° C. to obtain a stretchable elastic nonwoven fabric.

The properties of the obtained stretchable elastic nonwoven fabric are shown in Table 5. The nonwoven fabric having good spreadability and good sheet formation was obtained, but only a nonwoven fabric having poor elasticity was obtained.

[0050]

[Table 5] Table 5 <Operability> Adhesiveness: None Spreadability: Good <Non-woven fabric performance> Weight: 81 (g / m ² ) Longitudinal tensile strength: 10.1 (kg / 5cm) Longitudinal tensile elongation: 98 (%) Elastic recovery rate: 23 (%)

[0051]

Comparative Example 2 Melting point obtained by DSC was 187
PT, relative viscosity 2.07, number average molecular weight 1500
When the copolymerization ratio of MG and PBT is PTMG / PBT = 57 /
Forty-three copolymer polyester elastomers were melt-extruded singly under the conditions of a single hole discharge rate of 1.5 g / min.

Under these conditions, the yarn is spun from a spinneret having a hole diameter of 0.5 φ, a number of core-sheath composite yarns are cooled by a cooling device, and then a plurality of jets arranged at a position 210 cm below the spinneret at 2650 m / h. The web was taken up at a speed of one minute, spread by a corona discharge spreader, and deposited by a moving wire mesh deposition device to form a web. At this time, the denier of the single yarn was 5.1 d. Then, it was partially thermocompression-bonded with a hot embossing roll having a pressed area ratio of 12%, a point pattern, and a surface temperature of 155 ° C. to obtain a stretchable elastic nonwoven fabric.

The properties of the obtained stretchable elastic nonwoven fabric are shown in Table-6, but although the nonwoven fabric was excellent in elastic properties, the openability was poor and a nonwoven fabric with good formation was not obtained.

[0054]

Table 6 <Operability> Adhesiveness: Yes Opening property: Poor <Non-woven fabric performance> Weight: 83 (g / m ² ) Longitudinal tensile strength: 7.4 (kg / 5cm) Longitudinal tensile elongation: 145 (%) Elastic recovery rate: 45 (%)

[0055]

Comparative Example 3 The melting point obtained by DSC was 208.
° C, PT with relative viscosity 1.92, number average molecular weight 1500
When the copolymerization ratio of MG and PBT is PTMG / PBT = 40 /
Melting temperature of 60 copolymer polyester elastomer
The mixture was melt-extruded as a single unit at 55 ° C. and a single hole discharge rate of 1.5 g / min.

Under these conditions, the yarn is spun from a spinneret having a hole diameter of 0.5 φ, a number of core-sheath composite yarns are cooled by a cooling device, and then 3150 m / h by a plurality of jets arranged 170 cm below the die. The web was taken up at a speed of one minute, spread by a corona discharge spreader, and deposited by a moving wire mesh deposition device to form a web. At this time, single yarn denier is 4.3d
Met. Then, the pressure contact area ratio is 12%, point pattern,
Partial thermocompression bonding was performed with a hot embossing roll having a surface temperature of 155 ° C. to obtain a stretchable elastic nonwoven fabric.

The properties of the obtained stretchable elastic nonwoven fabric are shown in Table 7. The nonwoven fabric having good spreadability and good sheet formation was obtained, but only a nonwoven fabric having inferior elasticity was obtained.

[0058]

[Table 7] Table 7 <Operability> Adhesiveness: None Spreadability: Good <Nonwoven fabric performance> Weight: 82 (g / m ² ) Longitudinal tensile strength: 8.3 (kg / 5cm) Longitudinal tensile elongation: 104 (%) Elastic recovery rate: 24 (%)

[0059]

According to the present invention, as described above, a polyester-based nonwoven fabric having an excellent elastic property, which has not been obtained in the past, can be economically and stably provided. The novel polyester-based elastic nonwoven fabric of the present invention can be used in a wide range such as pulp materials, interlining, supporters, stretch tapes, and the like.

[Brief description of the drawings]

FIG. 1 is a process schematic diagram showing one embodiment of a method for producing a polyester-based elastic nonwoven fabric according to the present invention.

FIG. 2 is a schematic view showing an example of a combination of cross sections of single yarns of a conjugate fiber used in the present invention.

FIG. 3 is a schematic view showing an example of a combination of cross sections of single yarns of a conjugate fiber used in the present invention.

FIG. 4 is a schematic view showing an example of a combination of cross sections of single yarns of a conjugate fiber used in the present invention.

Continuation of the front page (72) Inventor Hiroshi Nishimura 23 Uji Kozakura, Uji-city, Kyoto Unitika Inside Central Research Laboratory, Inc. (56) References JP-A-61-194247 (JP, A) JP-A-2-269854 (JP, A) JP-A-57-82553 (JP, A) JP-A-56-118911 (JP, A) JP-A-5-131580 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) ) D04H 1/00-18/00 D01D 5/34

Claims (2)

(57) [Claims] 1. A copolymerized polyester elastomer comprising a polyester containing polybutylene terephthalate as a main component and a polyether containing polytetramethylene glycol as a main component, wherein the polyester component is 49 to 20% by weight and the polyether component is 51 to 51% by weight. A component having a high polyether content ratio of 80% by weight is disposed in the core component, and a component having a low polyether content ratio of 90 to 51% by weight of the polyester component and 10 to 49% by weight of the polyether component is disposed in the sheath component. A stretchable polyester-based elastic nonwoven fabric, characterized in that core-sheath composite filaments are partially thermocompression-bonded. 2. A fiber web is formed by melt-spinning at a temperature 15 to 80 ° C. higher than the melting point of the polyester elastomer as the sheath component of the composite filament, drawing at 2,000 to 4,000 m / min, and collecting the opened fibers to form a fibrous web. Then, the nonwoven fabric is partially thermocompression-bonded with an embossing roll having a temperature 5 to 30 ° C. lower than the melting point of the sheath component of the composite long fiber determined by DSC and an embossing area ratio of 4 to 40%. The method for producing a polyester-based elastic nonwoven fabric according to claim 1, characterized in that: