JPH09132848A - Non-woven fabric for integrating porous base material, production of non-woven fabric for integrating porous base material, composite product integrated with the non-woven fabric for integrating porous base material, and production of the composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a non-woven fabric capable of integrating porous base materials, while maintaining the non-integrated states of the porous base materials, to provide a method for producing the non-woven fabric, to obtain a composite product integrated with the non- woven fabric, and to provide a method for producing the composite product. SOLUTION: This non-woven fabric contains ultra fine fibers having a fiber diameter of <=3μm and comprises two or more kinds of resin components. The non-woven fabric can be formed by binding fiber webs containing dividable fibers capable of being divided into the ultra fine fibers, and simultaneously or subsequently dividing the dividable fibers to generate the ultra fine fibers. The objective composite product comprises the same or different porous base materials and the above non-woven fabric integrally laminated between the porous base materials. The objective composite material can be formed by laminating the above non-woven fabric between the same or different kinds of the porous base materials and subsequently applying ultrasonic waves to at least one side of the laminated product in a liquid-containing state. Therein, the ultra fine fibers of the non-woven fabric are mainly invaded into or entangled with the pores of the porous base material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nonwoven fabric capable of integrating porous substrates of the same type or different types, a method for producing the nonwoven fabric for integrating the porous substrates, and the nonwoven fabric for integrating the porous substrates. The present invention relates to a composite and a method for producing the composite.

[0002]

2. Description of the Related Art For example, in order to form a bulky fiber aggregate such as padded cotton, after stacking two or three fiber sheets,
There is a method of entanglement and integration with a needle or water flow. However, when the entanglement and integration are performed by such a method, there is a problem that the thickness of the fiber sheet is reduced, the amount of air that functions as heat insulation is reduced, and the performance as a batting is deteriorated.

Further, in order to form a gas or liquid filter having a coarse and dense structure, a coarse structure fiber sheet and a dense structure fiber sheet having an apparent density as designed are entangled and integrated by a needle or water flow, The thickness of the filter decreases, the apparent density of each fiber sheet changes,
It is not possible to form a filter as designed.

[0004]

The present invention has been made to solve the above problems, and is a nonwoven fabric which can be integrated while maintaining the state before the integration of the porous substrate.
It is an object of the present invention to provide a method for producing this nonwoven fabric, a composite body integrated with this nonwoven fabric, and a method for producing this composite body.

[0005]

The nonwoven fabric for integrating porous substrates of the present invention (hereinafter referred to as "nonwoven fabric for integration") is ultrasonic wave after being laminated between the same or different kinds of porous substrates. Is a non-woven fabric for integration that is used to integrate the porous base material by the action of.
Since it contains ultrafine fibers of m or less, the ultrafine fibers can invade and be entangled with the porous substrate by applying ultrasonic waves, and can be easily integrated.

The method for producing the non-woven fabric for integration of the present invention is 2
Simultaneously with or after bonding a fibrous web containing splittable fibers that can be split into ultrafine fibers, which consists of more than one type of resin component, is a method of splitting the splittable fibers to generate ultrafine fibers, It has strength and can easily form a non-woven fabric containing ultrafine fibers for integration.

The composite of the present invention is a composite in which the above-mentioned nonwoven fabric for integration is laminated and integrated between the same or different kinds of porous substrates, and this composite is mainly the nonwoven fabric for integration. Since the ultrafine fibers of (1) have entered the pores of the porous base material and are entangled with each other, the state of the porous base material before the integration is maintained.

The method for producing a composite of the present invention comprises the steps of laminating the above nonwoven fabric for integration between porous substrates of the same type or different types, and then superposing the laminated nonwoven fabric from at least one side of the laminated body in a liquid-containing state. This is a method in which the ultrafine fibers of the nonwoven fabric for integration are mainly caused to invade the pores of the porous base material by the action of a sound wave so that they are entangled with each other. Therefore, the state of the porous base material before the integration is maintained. It is a method that can be easily laminated and integrated.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The nonwoven fabric for integration of the present invention contains ultrafine fibers having a fiber diameter of 3 μm or less. If the fiber diameter of the ultrafine fibers exceeds 3 μm, the ultrasonic waves that act when the porous base materials are integrated hardly cause the entanglement action and the integration becomes impossible. Therefore, the fiber diameter is 3 μm or less, preferably 1. It contains ultrafine fibers of 5 μm or less, more preferably 1 μm or less, and most preferably 0.5 μm or less. In addition, when the cross-sectional shape of the ultrafine fiber is a non-circular shape, the value converted into a circular cross section is taken as the fiber diameter.

As the ultrafine fibers having a fiber diameter of 3 μm or less, those obtained by dividing a divisible fiber that can be divided into ultrafine fibers composed of two or more kinds of resin components may be used, or obtained by a melt blowing method. Although fine fibers may be used, the ultrafine fibers obtained by dividing the former splittable fibers are stretched and oriented, and are superior in strength to the latter ultrafine fibers and have a high peel strength with the porous substrate. Therefore, it can be preferably used. Hereinafter, a case of generating ultrafine fibers from splittable fibers will be described.

The splittable fiber may be any fiber that can be split by mechanical and / or chemical treatment. For example, as shown in the schematic cross-sectional view of the fiber in FIG. A sea-island type fiber having an island-shaped fiber cross section, a multi-bimetal type fiber having a fiber cross section in which one component A and another component B are alternately laminated in layers as shown in the fiber cross-section schematic diagram, or Is a chrysanthemum flower having a fiber cross section in which one component A is divided by another component B extending from the inside of the fiber (preferably the fiber axis) to the fiber surface, as shown in FIGS. 3 (a) and 3 (b). -Type fiber, or sea-island type fiber, multiple bimetal type fiber, and chrysanthemum-type fiber are appropriately compounded, that is, the island component of the sea-island type fiber is sea-island type, multiple bimetal type,
A fiber having a chrysanthemum-shaped cross-sectional shape, one component and / or other component of a multi-bimetal type fiber is a sea-island type, a multi-bimetal type, a fiber having a chrysanthemum-shaped cross-sectional shape, one component and / or another component of a chrysanthemum-type fiber Fibers having a sea-island type, multiple bimetal type, or chrysanthemum type cross-sectional shape can be used. Among these, the sea-island type fibers can easily generate ultrafine fibers having a fiber diameter of 3 μm or less, and thus can be preferably used.

The resin component constituting the splittable fiber may be composed of two or more kinds of resins capable of forming fibers, and examples thereof include polyamides such as nylon 6, nylon 66, and nylon copolymers, polyethylene terephthalate, polyethylene. Polyester such as terephthalate copolymer, polybutylene terephthalate and polybutylene terephthalate copolymer, polyolefin such as polyethylene, polypropylene and polymethylpentene, polyurethane,
Aliphatic polyester-based polymers such as polyacrylonitrile, vinyl polymers, polyglycolic acid, glycolic acid copolymers, polylactic acid, lactic acid copolymers, etc., the aliphatic polyester-based polymers being capamide, tetramethylene adipamide Resins such as aliphatic polyesteramide-based copolymers obtained by copolymerizing aliphatic amides such as undecanamid, laurolactamide, and hexamethyleneadipamide can be used.

When sea-island type fibers are used as the splittable fibers, use of an aliphatic polyester polymer or an aliphatic polyesteramide type copolymer as the sea component is suitable for production because it can be easily removed by an alkaline aqueous solution. In addition, since these resin components are biodegradable and the waste liquid decomposed and extracted can be easily treated, they can be preferably used. In addition,
Since the ultrafine fibers generated from the splittable fibers are thermoplastic, there is also a feature that the ultrafine fibers can be more firmly integrated by being entangled with the porous substrate and then fused. Further, the cross section of the ultrafine fibers made of the thermoplastic resin component has a core-sheath shape, and when the sheath component has a lower melting point than the core component, even if the ultrafine fibers are fused, the The strength is maintained and the porous base material can be firmly integrated. The splittable fiber composed of such a resin component can be easily spun by a conventional composite spinning method, a mixed spinning method, or a combination thereof. Further, a flame retardant, an antistatic agent, a hygroscopic agent, a coloring agent, a dyeing agent, a conductive agent, a hydrophilizing agent and the like may be mixed within a range that does not reduce the spinnability and the fiber strength.

When such an ultrafine fiber is contained in the nonwoven fabric for integration in an amount of 20% by weight or more, it can be firmly integrated with the porous substrate. However, the more the ultrafine fiber is, the more the ultrafine fiber is. Since the fibers can penetrate into the pores of the porous substrate and be entangled with each other, it is preferable that the content of the fibers is 50% by weight or more.
More preferably, it is contained in an amount of not less than 100% by weight, most preferably 100% by weight. Examples of the fibers other than the ultrafine fibers include natural fibers such as silk, wool, cotton and hemp, regenerated fibers such as rayon fibers, semi-synthetic fibers such as acetate fibers, polyamide fibers, polyvinyl alcohol fibers, acrylic fibers, polyester fibers. It is possible to mix synthetic fibers such as polyvinyl chloride fibers, polyvinylidene chloride fibers, polyurethane fibers, polyethylene fibers, polypropylene fibers, and aromatic polyamide fibers. Further, by mixing and adhering a core-sheath type adhesive composite fiber composed of two or more resin components and adhering them, the peeling strength between the porous base materials is improved, or eccentric type, laminated type, etc. Stretchability can be imparted by mixing bicomponent fibers capable of expressing crimp and causing crimp to follow the stretching of the porous substrate.

The fibrous web containing the splittable fibers as described above can be formed by a dry method such as a card method or an air lay method, or a wet method. The fiber length varies depending on the method of forming the fibrous web. When the former dry method is used, fibers of 20 to 110 mm are used, and when the latter wet method is used, fibers of 1 to 30 mm are used. use. The former dry method is more preferable because the fiber length is longer and the peel strength of the porous substrate can be increased. Further, these fiber webs may be appropriately combined and laminated.

Next, the fibrous web containing the splittable fibers is bonded to form a bonded fibrous web. As a method of bonding the fibrous web containing the splittable fiber, a method of entanglement with a needle or a water stream, a method of bonding with an adhesive, a method of fusing with a thermoplastic component of the splittable fiber or a mixed thermoplastic fiber, a special There is a method of stitching with a fine needle, but a method of entanglement with a needle or a water flow that can maintain the bonding strength even after the ultrafine fibers are generated is preferable. Among these, the method of entanglement with water flow is
This is more preferable because the entire fibrous web can be uniformly entangled without damaging the splittable fibers.

The entanglement condition by this water flow is, for example, a nozzle diameter of 0.05 to 0.3 mm, preferably 0.08 to 0.03.
2 mm, pitch 0.2-3 mm, preferably 0.4-2 mm, using nozzle plates arranged in one or more rows, pressure 10-3
A water stream of 00 kg / cm ² , preferably 50-250 kg / cm ² , is jetted. The entanglement by the water flow does not have to be performed once, and if necessary, jetting is performed twice or more from one side or both sides of the fibrous web. The pressure of the water stream may be changed, or the nozzle may be swung or vibrated.

If the non-perforated portion of the support, such as a net or mesh, which conveys the fibrous web when it is entangled with a water stream is made large, a bonded fibrous web having holes can be formed in appearance, and By reducing the size of the non-perforated portion, it is possible to form a bonded fibrous web having no pores in appearance. The former is suitable when the transfer of gas, liquid, solid or the like between the porous substrates is required, and the latter is suitable when it is not necessary. More specifically, in the former case, a coarse net of less than 50 mesh composed of a thick wire with a wire diameter exceeding 0.25 mm or a perforated plate corresponding to this is used, and in the latter case, Consists of a thin wire with a wire diameter of 0.25 mm or less, 5
A fine mesh of 0 mesh or more or a perforated plate corresponding to this is used.

Then, the splittable fibers constituting the bonded fiber web are split to form an unwoven fabric containing ultrafine fibers. The method of splitting this splittable fiber differs depending on the type of splittable fiber.In the case of sea-island type fiber, it is extracted with a solvent that can extract sea components and split into ultrafine fibers, and the multi-bimetal type fiber and chrysanthemum type fiber are separated. In this case, a liquid such as water or a solid such as a needle or a calender is allowed to act to divide it into ultrafine fibers. In the case of the latter multiple bimetal type fiber or chrysanthemum type fiber, since the fiber web can be entangled and can be split at the same time, there is an advantage that the splitting step of this splittable fiber can be omitted. On the other hand, as described above, the sea component of the sea-island fiber is
An aliphatic polyester polymer or an aliphatic polyester amide-based copolymer is suitable for the process because it can be easily removed with an alkaline solution, and since these resin components are biodegradable, the waste liquid decomposed and extracted is treated. There is an advantage that it is easy to do.

It should be noted that multiple bimetal type fibers and chrysanthemum type fibers are used as the splittable fibers and are formed by hydroentanglement,
In terms of appearance, in a bonded fiber web having pores, that is, a non-woven fabric for integration, mainly fiber groups in which ultrafine fibers are entangled substantially intersect each other, and further, they are entangled at intersections between the fiber groups. On the other hand, using sea-island type fibers as splittable fibers, formed by hydroentanglement, in appearance, constituting a bonded fiber web having pores, nonwoven fabric for integration formed by extracting the sea component of sea-island type fibers is The fiber groups in which the bundles of ultrafine fibers are entangled substantially intersect each other, and the bundles of ultrafine fibers are also entangled mainly at the intersections between the fiber groups. The latter nonwoven fabric for integration is excellent in strength, and the ultrafine fibers are easily entangled by ultrasonic waves.

Further, multiple bimetal type fibers or chrysanthemum type fibers are used as the splittable fibers and are formed by hydroentangling.
In a bonded fiber web having no pores in appearance, that is, a non-woven fabric for integration, ultrafine fibers are mainly entangled over the whole non-woven fabric for integration. On the other hand, using sea-island type fibers as splittable fibers, formed by hydroentangling, to form a bonded fiber web with no holes in appearance, the nonwoven fabric for integration formed by extracting the sea component of sea-island type fibers is , Bundles of ultrafine fibers are intertwined. The latter nonwoven fabric for integration has excellent tensile strength, and ultrafine fibers are easily entangled by ultrasonic waves. in this way,
It is preferable to use sea-island type fibers as the splittable fibers, because they are present in the state of a bundle of ultrafine fibers and are easily entangled with the porous base material by ultrasonic waves rather than being entangled with the ultrafine fibers.

The unit weight of the nonwoven fabric for integration of the present invention is not particularly limited, but is preferably ² to 150 g / m ² in order not to adversely affect the porous substrate.
It is more preferably about 100 g / m ² .

The composite of the present invention is one in which the above-mentioned non-woven fabric for integration is laminated and integrated between the same or different types of porous substrates, and this composite mainly constitutes the non-woven fabric for integration. Since the ultrafine fibers penetrate the pores of the porous base material and are entangled with each other, the porous base material maintains the state before the integration.

The porous substrate may be, for example, a net, woven fabric, knitted fabric, non-woven fabric, or the like, but ultrafine fibers penetrate into the pores of the porous substrate by the ultrasonic treatment described later. However, the wire diameter (or fiber diameter) is preferably 1.5 mm or less so that they are easily entangled. When the fiber diameter of the ultrafine fibers constituting the unifying nonwoven fabric is about 3 μm, the pore diameter (or average pore diameter) of the porous substrate should be about 35 μm or more, but the fiber diameter is 1 μm or less. In some cases, a porous substrate having a pore size (or average pore size) of about 15 μm can also be integrated, which is more versatile.

The composite of the present invention is mainly prepared by laminating the above-mentioned non-woven fabric for integration between porous substrates and then applying ultrasonic waves from at least one side of the laminate in a liquid-containing state. The ultrafine fibers forming the unifying nonwoven fabric can be formed by invading the pores of the porous base material and entangled with each other. In addition, when it is preferable that a uniform structure is formed over the entire composite body, it is preferable that a heterogeneous structure is formed, for example, by laminating porous substrates of the same kind to have a coarse and dense structure. The porous base materials are laminated. When it is necessary to move gas, liquid, or solid between the porous substrates, a non-woven fabric having a hole is used for the appearance. It is preferable to use a non-woven fabric having no pores for integration. Further, the number of the porous base materials does not have to be two, and may be three or more, and a non-woven fabric for integration may be laminated between the respective porous base materials.

In the present invention, ultrasonic waves are applied from at least one side of the laminate in a liquid-containing state, which means that the laminate of the porous substrate and the non-woven fabric is in liquid. The state in which the liquid is adhered to at least the nonwoven fabric for integration, such as the state in which the liquid is sprayed or impregnated with the liquid. As the liquid used when applying the ultrasonic waves, water or an organic solvent that does not attack the ultrafine fibers can be used. In particular, it has good wettability with ultrafine fibers,
It is preferable to use a liquid in which the ultrafine fibers penetrate into the porous substrate by ultrasonic waves and are easily entangled. For example, when the ultrafine fibers are made of polypropylene, it is preferable to use alcohol such as ethanol or propanol, or Perklen, and when the ultrafine fibers are made of nylon, it is preferable to use alcohol or water.

With respect to the ultrasonic waves used in the present invention, the case of downward irradiation with an ultrasonic horn will be described as an example. The frequency is 1 to 100 kilohertz (kHz), preferably 10 to 10.
The amplitude is preferably 10 to 150 μm at 50 kHz. If this amplitude is less than 10 μm, it takes time for the entanglement of the ultrafine fibers, and if it exceeds 150 μm, the ultrafine fibers and the porous substrate are likely to be damaged, and the ultrasonic horn itself is likely to be damaged, which is more preferable. The amplitude is 15-100 μm. In order to efficiently entangle the ultrafine fibers with ultrasonic waves, for example, a porous base material and a nonwoven fabric for integration are provided on a reflecting plate that reflects ultrasonic waves, such as a metal plate having a thickness of 5 mm or more. It is preferable to place the laminate of and to apply ultrasonic waves. When using this reflector, the distance between the reflector and the ultrasonic horn is 50 mm so that it can be easily entangled with ultrasonic waves.
The thickness is preferably not more than 35 mm, more preferably not more than 35 mm. In addition, the action time of the ultrasonic wave does not damage the ultrafine fibers or the porous substrate, so that the complex can be efficiently formed,
It is preferably 10 seconds or less. Further, as an ultrasonic wave oscillation method, for example, a magnetostrictive oscillator, a piezoelectric oscillator, an electrostrictive oscillator, an electromagnetic oscillator, a siren oscillator, a cavity resonant oscillator, a wedge resonant oscillator, etc. Can be used. The above is the case of downward irradiation with an ultrasonic horn, but for a laminate of a porous substrate and a nonwoven fabric for integration,
The method is not particularly limited as long as it is a method capable of irradiating an ultrasonic wave having an amplitude of m or more.

If the contact surface of the porous substrate with the non-woven fabric for integration contains ultrafine fibers having a fiber diameter of 3 μm or less, the ultrafine fibers of the porous substrate also contribute to the entanglement, and the fiber diameter 3μ
If the ultrafine fibers of m or less are not included, only the ultrafine fibers of the nonwoven fabric for integration are involved in the entanglement. Also, ultrasonic waves
It is not necessary to act on the entire surface of the laminate of the porous base material and the non-woven fabric for integration, and it works partially within the range where the necessary peel strength can be obtained depending on the type of the porous base material and the intended use. You may let me.

As described above, since the composite body of the present invention maintains the state before the integration of the porous base material, if the porous base material is manufactured as designed, the accuracy is as designed. is there. As this composite, for example, a composite in which a non-woven fabric for integration is laminated and integrated between a bulky non-woven fabric (porous substrate) is used as a padding, or a non-woven fabric having a dense structure (porous substrate). It is possible to use, as a filter, a composite body in which a non-woven fabric for integration which has pores is laminated and integrated between the non-woven fabric and the non-woven fabric (porous substrate) having a rough structure. In addition,
The complex of the present invention can be further chemically or physically treated,
Various functions can be added to suit various purposes.

Examples of the present invention will be described below, but the invention is not limited to the following examples. The average pore diameter is a value measured by the bubble point method using a porometer (manufactured by Coulter). In addition, since the thickness of the porous substrate having a thickness of 2 mm or more is crushed during the measurement,
It is smaller than the actual value.

[0031]

【Example】

(Example 1) Copolyester and polypropylene were mixed and spun in a pellet state with a weight ratio of 57.5: 42.5, stretched, and then cut into 38 mm to obtain an island component of polypropylene of about 2,200. Have (average fiber diameter 0.2
1 μm) and a fineness of 1.4 denier sea-island type splittable fiber was formed. Using 100% of this sea-island type splittable fiber, a unidirectional fiber web formed by a card machine is crossed with a cross layer in the traveling direction of the fiber web to form a crossed fiber web having a basis weight of 70 g / m ^2. did. This crossed fiber web was placed on a 100-mesh net (wire diameter 0.15 mm), and a water stream with a pressure of 80 kgf / cm ² was jetted from a nozzle (fixed) arranged with a diameter of 0.13 mm and a pitch of 0.6 mm. Then, after reversing the crossed fiber web, a water stream having a pressure of 120 kgf / cm ² was ejected from the same nozzle, and after reversing the crossed fiber web, a pressure of 120 kgf / cm ² was discharged from the same nozzle.
After injecting a water flow of cm ² and further reversing the crossed fiber web, a water flow of 120 kgf / cm ² in pressure was jetted from the same nozzle, and the crossed fiber web was entangled to form an entangled fiber web. . Then, the entangled fiber web is heated at a temperature of 80.
By dipping in a 10% by weight sodium hydroxide aqueous solution for 20 minutes at 20 ° C., the copolyester, which is the sea component of the sea-island type splittable fiber, is decomposed and extracted to give a polypropylene ultrafine fiber with a basis weight of 30 g / m ² and a thickness of 0.28 mm. To form a non-woven fabric for integration which has no pores in appearance. When the cross section of the unifying nonwoven fabric was observed with an electron microscope, it was confirmed that bundles of ultrafine fibers were entangled in the entire unifying nonwoven fabric.

On the other hand, polyester fiber (fiber diameter 14.3)
μm, fiber length 51 mm) 100%, unidirectional fiber web formed by card machine is cross layered
54 g / unit weight, crossing the direction of travel of the fiber web
An m ² crossed fiber web was formed. Then, spray acrylic binder from both sides of this crossed fiber web,
After drying, the basis weight is 60 g / m ² , the thickness is 5 mm, and the average pore size is 100 μ.
A non-woven fabric (porous substrate) having a size of m or more was formed.

Next, a non-woven fabric for integration made of the polypropylene ultrafine fibers is laminated between the polyester non-woven fabric (porous substrate), and the laminated product is placed on a steel plate having a thickness of 1 cm in Perkren. In this condition, the electrostrictive ultrasonic horn located 7 mm above the iron plate is used to irradiate ultrasonic waves with a frequency of 19.5 kHz and an amplitude of 50 μm for 2 seconds from one side to the other side. To penetrate into the pores of the polyester nonwoven fabric (porous substrate),
Entangled to form a composite. Since this composite is bulky and has excellent heat retention, it was suitable as a batting.

(Example 2) A crossed fiber web having a basis weight of 70 g / m ² formed in exactly the same manner as in Example 1 was placed on a 50 mesh net (wire diameter 0.28 mm) to have a diameter of 0.15 m.
From nozzles arranged at m and pitch of 0.6 mm, pressure 70 kgf /
A water stream of cm ² is jetted, then the crossed fiber web is inverted and placed on a 15 mesh net (wire diameter 0.75 mm), and a water jet of pressure 80 kgf / cm ² is jetted from the same nozzle, The crossed fiber webs were entangled to form an entangled fiber web having holes in appearance. Next, this entangled fiber web is immersed in a 10% by weight aqueous sodium hydroxide solution at a temperature of 80 ° C. for 20 minutes to form a sea component of the sea-island type splittable fiber.
The copolyester was decomposed and extracted to form a non-woven fabric having pores in appearance and made of polypropylene ultrafine fibers having a basis weight of 30 g / m ² and a thickness of 0.28 mm. In addition, when observing this non-woven fabric with an electron microscope,
It was confirmed that the fiber groups in which the bundles of ultrafine fibers were entangled substantially crossed over the entire nonwoven fabric for integration, and the bundles of ultrafine fibers were entangled mainly at the intersections of the fiber groups.

On the other hand, a fiber diameter 2 having a cross-sectional shape in which polypropylene resin and polyethylene resin are laminated
A fiber diameter of 46.9, which has a cross-sectional shape in which 90% by weight of side-by-side type composite fiber having a fiber length of 1.7 mm and a fiber length of 51 mm and polypropylene resin and polyethylene resin are laminated.
Side-by-side type composite fiber 10 with μm and fiber length of 76 mm
After mixing with 100% by weight, a unidirectional fiber web formed by a card machine was crossed by a cross layer to form a crossed fiber web in which the direction of travel of the fiber web was crossed.
Then, this crossed fiber web is treated with hot air at 150 ° C. to fuse only the polyethylene resin component,
A coarse nonwoven fabric (porous substrate) having a thickness of 0 g / m ² , a thickness of 8 mm, an apparent density of 0.013 g / cm ³ , and an average pore diameter of 100 μm or more was formed.
Further, the same as the above, 65% by weight of side-by-side type composite fiber having a fiber diameter of 21.7 μm and a fiber length of 51 mm, and a cross-sectional shape in which polypropylene resin and polyethylene resin are laminated, fiber diameter of 15.3 μm, fiber length of 51 mm After mixing with 35% by weight of the side-by-side type composite fiber, a unidirectional fiber web formed by a card machine was crossed with a cross layer to form a crossed fiber web intersecting with the traveling direction of the fiber web. Then, this crossed fiber web is treated with hot air at 150 ° C. to fuse only the polyethylene resin component, and a basis weight of 100 g / m ² , a thickness of 5 mm, an apparent density of 0.02 g / cm ³ and an average pore diameter of 85 μm are obtained. A non-woven fabric (porous substrate) was formed.

Next, a non-woven fabric for integration made of the polypropylene ultrafine fibers is laminated between the coarse non-woven fabric (porous substrate) and the dense non-woven fabric (porous substrate), and the resulting laminate is placed in Parkren. Placed on an iron plate with a thickness of 1 cm, located 12 mm above the iron plate, an electrostrictive ultrasonic horn was used to apply ultrasonic waves with a frequency of 19.5 kHz and an amplitude of 50 μm for 3 seconds, one side at a time to the entire surface. Irradiation, the polypropylene ultrafine fibers alone were allowed to enter the pores of the coarse and dense nonwoven fabrics and entangled to form a composite. This composite had a dense structure and was suitable as a filter.

[0037]

EFFECT OF THE INVENTION The nonwoven fabric for integrating a porous substrate of the present invention is
A non-woven fabric for integrating porous substrates, which is used to integrate ultrasonic substances by laminating it between the same or different types of porous substrates. Since the nonwoven fabric for integration contains ultrafine fibers with a fiber diameter of 3 μm or less, ultrasonic waves penetrate the ultrafine fibers into the porous substrate,
It can be entangled and easily integrated.

The method for producing a nonwoven fabric for integrating with a porous substrate of the present invention is carried out at the same time as or after bonding a fiber web containing splittable fibers which are composed of two or more kinds of resin components and can be split into ultrafine fibers. Since this method is a method of dividing the splittable fibers to generate ultrafine fibers, a nonwoven fabric for integrating a porous base material having strength and containing the ultrafine fibers can be easily formed.

The composite of the present invention is a composite in which the above-mentioned nonwoven fabric for integrating a porous base material is laminated and integrated between the same or different types of porous base materials. Since the ultrafine fibers of the nonwoven fabric for integrating a porous base material penetrate into the pores of the porous base material and are entangled with each other, the state of the porous base material before the integration is maintained.

In the method for producing a composite of the present invention, the above-mentioned nonwoven fabric for integrating porous substrates is laminated between the same or different kinds of porous substrates, and then the liquid-containing material is applied from at least one side of the laminate. By applying ultrasonic waves under the condition,
Since this is a method of infiltrating the ultrafine fibers of the nonwoven fabric for integrating a porous substrate into the pores of the porous substrate and entangled them,
This is a method in which lamination and integration can be performed while maintaining the state of the porous base material before integration.

[Brief description of the drawings]

FIG. 1 is an example of a cross-sectional shape of a splittable fiber of the present invention.

FIG. 2 is another example of the cross-sectional shape of the splittable fiber of the present invention.

FIG. 3 (a) Another example of the sectional shape of the splittable fiber of the present invention (b) Another example of the sectional shape of the splittable fiber of the present invention

[Explanation of symbols]

 A One component B Other component

Claims (8)

[Claims] 1. A non-woven fabric, which is used to integrate ultrasonic treatment to the porous substrate after laminating it between the same or different kinds of porous substrates, and the nonwoven fabric has a fiber diameter of 3 μm.
A non-woven fabric for integrating a porous substrate, which contains ultrafine fibers of m or less. 2. The nonwoven fabric for integrating a porous substrate according to claim 1, wherein the ultrafine fibers are entangled in a bundle. 3. The fiber group in which the ultrafine fibers and / or the bundles of the ultrafine fibers are entangled with each other, and the fiber groups are also entangled with each other at an intersection of the fiber groups. Nonwoven fabric for integrating porous substrates. 4. The nonwoven fabric for porous substrate integration according to claim 1, wherein the ultrafine fibers are stretched and oriented. 5. A fibrous web comprising two or more kinds of resin components and containing splittable fibers that can be split into ultrafine fibers is bonded at the same time or after the binding, the splittable fibers are split to generate ultrafine fibers. A method for producing a nonwoven fabric for integrating a porous substrate, the method comprising: 6. The method for producing a nonwoven fabric for integrating with a porous substrate according to claim 5, wherein the splittable fiber is a sea-island type fiber. 7. A composite body in which the nonwoven fabric for integrating a porous substrate according to any one of claims 1 to 4 is laminated and integrated between the same or different porous substrates, and the composite The body is a composite body in which the ultrafine fibers of the nonwoven fabric for integrating a porous substrate are mainly infiltrated and entangled in the pores of the porous substrate. 8. The non-woven fabric for porous substrate integration according to any one of claims 1 to 4 is laminated between the same or different types of porous substrates, and then from at least one side of the laminate. Characterized in that by applying an ultrasonic wave in a liquid-containing state, the ultrafine fibers of the porous base material-integrating nonwoven fabric are mainly infiltrated into the pores of the porous base material and entangled with each other.
Method for producing composite.