JPH09132875A - Microporous sheetlike material, substrate for artificial leather and their production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject microporous sheetlike material, capable of controlling the pliability, abrasion resistance and strength of the material in good balance within proper ranges and useful as a substrate for an artificial leather by surrounding two kinds of specific fibers in a nonwoven base fabric with an elastic polymer in a specific state. SOLUTION: This microporous sheetlike material comprises a nonwoven base fabric prepared by blending (A) aromatic polyester fibers with (B) polyolefin fibers or polyamide fibers, impregnated with an elastic polymer and solidified. A sheetlike material having 0.5-6.0 pliability and 1,500-8,000 abrasion resistance can be produced by adding a surfactant having a silicone segment therein into a polar organic solution of the elastic polymer, etc. The fibers (A) are bonded and surrounded with the elastic polymer and the fibers (B) are surrounded in a nonbonded state therewith.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a microporous sheet, particularly a substrate for artificial leather, and a method for producing them. More specifically, it is a microporous sheet-like material obtained by impregnating a non-woven fabric with an elastic polymer, and has properties such as flexibility, abrasion resistance, tensile strength and tear strength easily and appropriately according to the purpose and application. The present invention relates to a microporous sheet material that can be adjusted to various ranges and a method for producing the same. The microporous sheet material of the present invention can be advantageously used as a substrate for artificial leather.

A base material for artificial leather, which can be coated with a high molecular weight polymer on its surface to form a silver-finished artificial leather, or can be ground to form a suede-like or nubuck-like artificial leather, Conventionally, a woven fabric, a knitted fabric, or a non-woven base fabric is generally impregnated with a high-molecular polymer. Particularly, from the viewpoint of strength and durability, the non-woven base fabric is made of an elastic polymer such as polyurethane. It is generally impregnated with. However, in producing microporous sheet materials suitable for these artificial leather substrates, a fibrous base cloth such as a non-woven fabric is simply impregnated with a solution of an organic polar solvent such as dimethylformamide, which is an elastic polymer, so as to be solidified by water immersion. Just by doing, the elastic polymer will bond the fibers,
Features such as difficulty in elongation and abrasion resistance can be obtained, but it becomes hard and has a narrow range of use as a natural leather substitute, limiting its use. Therefore, in the prior art, various measures have been taken to prevent the elastic polymer from adhering to the fibers. For example, JP-A-47-9839 (U.S. Pat. No. 3811)
No. 923), there is a method in which a treatment agent such as silicone having a releasing effect on the elastic polymer is applied to the fiber surface before the impregnation. According to this method, when the medium of the impregnating liquid is water, it prevents the adhesion between the elastic polymer and the fiber, gives the fiber a large degree of freedom, and obtains a microporous sheet material suitable for a flexible artificial leather substrate. You can However, when the medium is an organic polar solvent such as dimethylformamide, the effect is small and a flexible sheet cannot be obtained. Further, when the fibers are covered with a treatment agent having a releasing effect such as silicone, flexibility is obtained because the elastic polymer does not adhere the fibers as described above, but the friction coefficient between the fibers is lowered and the fibers are easily stretched. Also, disadvantages such as deterioration of wear resistance are increased.

Further, as a method for producing a microporous sheet in which elastic polymer and fibers are not adhered, for example, Japanese Patent Publication No. 48
As described in JP-A-31955, a fiber surface is preliminarily provided with a water-soluble polymer such as polyvinyl alcohol and insoluble in dimethylformamide, impregnated with a dimethylformamide solution of polyurethane, and then water-immersed and solidified. After removing the polyvinyl alcohol, there is a method of washing and removing the polyvinyl alcohol. According to this method, it is possible to prevent the adhesion between the polyurethane and the fiber, give the fiber a large degree of freedom, and obtain a flexible substrate for artificial leather. However, even in this case, flexibility is obtained, but disadvantages such as easy elongation and reduced wear resistance also occur. That is, if the polyurethane and the fibers are completely adhered, there are advantages such as excellent wear resistance and less elongation, but there are drawbacks such as hardness and reduction in tear strength. Conversely, the polyurethane and the fibers are completely adhered. If it is not, flexibility will be obtained, but defects such as deterioration of wear resistance and easy elongation will occur.

[0004]

In recent years, artificial leather is used for shoes,
It is widely used for applications such as balls, furniture, clothing, gloves and other miscellaneous goods, and the required properties are different depending on the application and the type of processing method. Therefore, the conventional technology has reached the limit in finely responding to a wide range of applications and processing methods. Therefore, the present inventor can arbitrarily control the state of the bonded portion and the non-bonded portion (bonded portion and non-bonded portion) of the fiber and the elastic polymer in the non-woven fabric, depending on the use and the type of processing method. Correspondingly, research has been carried out for the purpose of providing a microporous sheet material suitable for an artificial leather substrate capable of easily changing this state (bonding and non-bonding density and proportion) and a method for producing the same. I advanced.

As a result, when a specific surfactant is dissolved in a solution of an elastic polymer, the non-woven fabric is impregnated with the solution, and the solution is solidified in water, the elastic polymer is changed depending on the kind of the polymer constituting the fiber. It was found that the fiber and the fiber have a bonded state and a non-bonded state. Thus, the present inventors constructed a non-woven fabric from at least two types of fibers, changed the ratio of the types of the fibers, and impregnated an elastic polymer solution containing a specific surfactant, thereby forming an elastic polymer and fibers. The inventors have found that the adhered part and the non-adhered part can be controlled arbitrarily, and that flexibility, abrasion resistance and strength can be balanced and can be controlled arbitrarily, and thus the present invention has been accomplished.

[0006]

According to the present invention, there is provided a microporous sheet material obtained by impregnating and coagulating an elastic polymer into a non-woven fabric, wherein (1) the non-woven fabric is (a) aromatic. (2) The microporous sheet material is (i) the fiber A is elastic, which is a non-woven base fabric in which group polyester fiber (fiber A) and (b) polyolefin fiber or polyamide fiber (fiber B) are mixed. A portion in which the polymer is adhered and surrounded and a portion in which the fibers B are surrounded by an elastic polymer in a non-adhesive state are scattered, and (ii) the degree of softness is 0.5 to 6.0, and (ii)
i) A microporous sheet-like article is provided, which has an abrasion resistance of 1500 to 8000.

Furthermore, according to the present invention, a non-woven fabric is impregnated with a solution of an elastic polymer in an organic polar solvent, and then the solution is coagulated in a coagulation bath mainly containing water to produce a microporous sheet. In the method, (1) a non-woven fabric base fabric in which polyester fibers (fiber A) and polyolefin fibers or nylon fibers (fiber B) are mixed is used as the non-woven fabric base fabric, and (2) as the organic polar solution therein. A water-dispersible or water-soluble surfactant having 0.1 to 10 parts by weight of a surfactant having a silicone segment as a hydrophobic group per 100 parts by weight of the elastic polymer solid is used. A method for manufacturing a porous sheet material is provided.

The microporous sheet material of the present invention and the method for producing the same will be described below in detail. The fibers that make up the nonwoven base fabric of the present invention are a mixture of two types of fibers, fiber A and fiber B. Fiber A is an aromatic polyester fiber and fiber B is a polyolefin fiber or a polyamide fiber. In the following description, "surfactant which is water-dispersible or water-soluble and has a silicone segment as a hydrophobic group" contained in an organic polar solvent solution is simply referred to as "silicone-based surfactant". May be abbreviated.

The fiber A is adhered to the fiber of the type A when the elastic polymer is solidified in the coagulation bath, regardless of the presence or absence of the silicone surfactant dissolved in the impregnating liquid. Aromatic polyester fibers are typical ones because they have surface characteristics that bring about a state. Specific examples of the aromatic polyester include polyethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalate, and copolymers thereof. Unlike the fiber B, the fiber A is in a state of adhesion between these fibers A and the impregnated elastic polymer (referred to as “adhesion”) despite the presence of the silicone-based surfactant mixed in the impregnating liquid. The mechanism that causes is not clear, but is presumed as follows. When the organic polar solvent solution of the elastic polymer impregnated in the vicinity of the fibers A is immersed in the coagulation bath solution containing water as a main component, the organic polar solvent which is the solvent elutes in the coagulation bath solution and the elastic polymer Coagulates, at which time the silicone-based surfactant coordinates on the elastic polymer surface. The surface of the elastic polymer is made water repellent by the polysiloxane segment which is the hydrophobic group of the coordinated silicone-based surfactant, but since the fiber A has a strong affinity with the polysiloxane, the adhesion between the elastic polymer and the fiber A is caused. It is thought to cause the condition. As the fiber A, a fiber of a copolymer containing polyethylene terephthalate or ethylene terephthalate unit in at least 80 mol%, preferably at least 85 mol% in all repeating units is preferable.

The fibers B constituting the non-woven fabric of the present invention include the fibers due to the effect of the silicone surfactant dissolved in the impregnating liquid when the elastic polymer is solidified in the coagulation bath. It has surface properties that result in a non-bonded state with B, so that the fibers B are surrounded by the elastic polymer in the unbonded state. Examples of the polymer forming the fiber B include polyolefins such as polypropylene and polyethylene, and 6 nylon, 6/6 nylon, 6 /
Aliphatic polyamides such as 10 nylon, 10/9 nylon, 10/10 nylon, 11 nylon and 12 nylon can be mentioned. Although the mechanism by which these fibers B and the elastic polymer impregnated in the presence of the silicone-based surfactant mixed in the impregnating liquid bring about a non-adhesion state (referred to as "non-adhesion") is not clear. It is estimated as follows. When the organic polar solvent solution of the elastic polymer impregnated in the vicinity of the fibers B is immersed in the coagulation bath solution mainly composed of water, the organic polar solvent which is the solvent elutes in the coagulation bath solution to give the elastic polymer. Coagulates, at which time the silicone-based surfactant coordinates on the elastic polymer surface. The surface of the elastic polymer is made water repellent by the polysiloxane segment, which is the hydrophobic group of the coordinated silicone-based surfactant, and the contact with the fiber B is prevented through the water / organic polar solvent mixture liquid existing between the elastic polymer surface and the fiber B. It is thought that this causes the non-adhesive state.

As the polymer forming the fiber B, polypropylene or polyethylene is preferable in the case of polyolefin, and 6 nylon or 6/6 in the case of nylon.
Nylon is preferred. As the fiber B, these polyolefin fibers are particularly preferable.

In the present invention, when a non-woven base fabric composed of fibers A and B is impregnated with a solution of an elastic polymer containing a silicone-based surfactant in an organic polar solvent and subjected to a water immersion coagulation treatment, the fiber B portion is removed. A microporous sheet having a structure in which a non-adhesive state is formed with an elastic polymer, while a portion of the fiber A forms an adhered state with the elastic polymer, that is, the non-adhered state and the adhered state of the fiber and the elastic polymer are randomly present. It becomes a thing. Generally, a non-adhesive microporous sheet is highly flexible because it gives the fiber a large degree of freedom, but it tends to be easily stretched and wear resistance tends to decrease. The sheet-like material is hard to elongate because of the lack of freedom of fibers and has a large abrasion resistance, but it is very hard. Thus, in the present invention, by adjusting the mixing ratio of the fiber A and the fiber B, it is possible to arbitrarily adjust the ratio of the non-bonding structure and the bonding structure of the elastic polymer and the fiber, and the flexibility, elongation stress, It is possible to widely select the balance of characteristics such as wear resistance as required. In the present invention,
The mixing ratio of the fibers A and the fibers B can be arbitrarily selected, but a non-woven fabric obtained by mixing the fibers A and the fibers B in a weight ratio of 70:30 to 5:95 is preferable from the viewpoint of flexibility. The ratio of fiber A: fiber B is 60:40 to 1 by weight.
The range of 0:90 is particularly preferable.

The form of the non-woven fabric of the present invention is not limited as long as the fibers composing the non-woven fabric are fibers A and fibers B, but the fibers A and fibers B are uniformly mixed throughout. Is desirable. By impregnating a non-woven fabric with a uniform mixture of fibers A and B with an elastic polymer, (a) a portion where fiber A is adhered and surrounded by an elastic polymer and (b) fiber B is not adhered by the elastic polymer. A microporous sheet-like product is obtained in which the two types of parts surrounded by are present in a uniformly dispersed state.

Specific examples of the form of the non-woven fabric of the present invention include (i) uniform opening of short fibers by an opening machine typified by a carding process, then laminating to form an open web, and needle punching. Alternatively, those subjected to fiber entanglement treatment by contact with a high-speed liquid flow, (ii) those subjected to fiber entanglement treatment by laminating a long fiber nonwoven fabric and the opened web, (iii) melt blown nonwoven fabric and the above opened fiber A web laminated and subjected to a fiber entanglement treatment, (iv) a wet method nonwoven fabric and the opened web subjected to a fiber entanglement treatment, and (v) two or more long fiber nonwoven fabrics Laminated and subjected to fiber entanglement treatment, and (vi) splittable fibers in which polymers of fibers A and fibers B are alternately arranged are used as the opening web, and are contacted by needle punching or high-speed fluid. The thing which gave the fiber entanglement process is mentioned.

The form of these non-woven base fabrics may be formed by mixing two kinds of fibers, or may be formed by laminating two or more kinds of fiber layers. In any case, it is preferable to appropriately combine the cotton mixing means, the laminating means, or the fiber entanglement means so that the non-woven fabric is a uniform mixture of the fibers A and B. As the form of the non-woven fabric, the one obtained by mixing the two types of short fibers of (i) above into an open fiber web and performing a fiber entanglement treatment is suitable as a sheet for artificial leather.

Fiber A and Fiber B constituting the non-woven base fabric
May be long fibers or short fibers. However, it is preferable that either one or both of them is a short fiber, and particularly, both of them are a short fiber. When either one is a long fiber, it is preferable that the fiber A is a long fiber. The fineness of the fiber A is 0.05 to 100 de, preferably 0.1 to 5.0 de, and the fiber B is suitable.
Has a fineness of 0.05 to 100 de, preferably 0.1 to 5.
A range of 0 de is suitable. In the case of short fibers, the fiber length depends on the form of the non-woven fabric, but is generally 20 to 20.
It is in the range of 0 mm, preferably 30 to 80 mm. In this case, not only isometric cutting but also bias cutting is included.

The elastic polymer in the present invention may be any elastic polymer which is usually used for the artificial leather base cloth.
Polyurethane is preferred. As such a polyurethane, one used as a base fabric for artificial leather is suitable, and is a conventionally known thermoplastic polyurethane obtained by a polymerization reaction of an organic diisocyanate, a polymeric diol and a chain extender. The organic diisocyanate used here is an aliphatic, alicyclic or aromatic diisocyanate containing two isocyanate groups in the molecule, particularly 4,4 '.
-Diphenylmethane diisocyanate, P-phenylene diisocyanate, toluylene diisocyanate, 1,
5-naphthalene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate and the like can be mentioned. As the polymer diol, for example, at least polyester glycol obtained by condensation polymerization of glycol and aliphatic dicarboxylic acid, polylactone glycol obtained by ring-opening polymerization of lactone, aliphatic or aromatic polycarbonate glycol, or polyether glycol is used. Examples thereof include polymer glycols having an average molecular weight of 500 to 4000 selected from one kind. And as the chain extender, a diol having two or less hydrogen atoms capable of reacting with isocyanate and having a molecular weight of 500 or less, for example, ethylene glycol, 1,4-butanediol, hexamethylene glycol, xylylene glycol, cyclohexanediol, neopentyl glycol, etc. Can be mentioned.

The elastic polymer, in particular polyurethane, is used as a solution (concentration 6-20% by weight) dissolved in an organic polar solvent. A microporous sheet material is formed by a method of impregnating a non-woven fabric with this solution, that is, a wet method. A microporous sheet is formed by a method in which an elastic polymer is coagulated by impregnating a non-woven fabric with the above solution and then extracting an organic polar solvent in a coagulation bath mainly composed of water.

Examples of the organic polar solvent used for dissolving the elastic polymer include dimethylformamide, diethylformamide, dimethylacetamide, dimethylsulfoamide, tetrahydrofuran and dioxane, of which dimethylformamide is preferable.

In order to obtain the microporous sheet-like product which is the object of the present invention, a non-woven fabric is used as a solution of an elastic polymer in an organic polar solvent, which is water-dispersible or water-soluble and has a hydrophobic property. A solution in which a surfactant having a silicone segment as a group (silicone surfactant) is added and mixed is used. This silicone-based surfactant preferably contains 10 to 90% by weight of a silicone segment. This silicone-based surfactant preferably has a polysiloxane unit as a hydrophobic group in the molecule and a unit mainly having a polyoxyalkylene chain as hydrophilicity. Alternatively, it can be obtained by a method of adding an alkylene oxide such as ethylene oxide as a hydrophilic group to a polysiloxane having a group that reacts with alkylene oxide such as ethylene oxide in the molecule. Further, it can be obtained by a method of reacting an organic polyisocyanate with a polysiloxane having a group capable of reacting with an isocyanate at the molecular end or in the molecule and then reacting with a polyoxyalkylene glycol mainly containing polyoxyethylene glycol.

As the silicone-based surfactant of the present invention, those which are substantially formed of a silicone segment and a polyalkylene oxide segment are suitable, and particularly, the silicone segment is 10 to 90% by weight, particularly preferably 20 to. Those containing 80% by weight are preferred. As the polyalkylene oxide, polyethylene oxide, polypropylene oxide, polybutylene oxide or copolymers thereof are preferable, and particularly polyethylene oxide or those mainly containing polyethylene oxide are preferable.

The silicone-based surfactant preferably has a molecular weight in the range of 1200 to 120,000, and the polysiloxane component in the molecule has a molecular weight of 400 to 25,000. The molecular weight of the polysiloxane component is less than 400, or the molecular weight of the silicone-based surfactant is 12
When it is less than 00, the silicone-based surfactant is easily leached from the coagulated elastic polymer, and when the molecular weight of the surfactant exceeds 120,000, the physical properties of the elastic polymer are not deteriorated. It becomes difficult to form a non-adhesive structure of B and the elastic polymer or to dissolve in the polar solvent.

In the present invention, the amount of the silicone-based surfactant added to the organic polar solvent solution of the elastic polymer is 0.1 part to 100 parts by weight of the elastic polymer solid weight.
It is 10 parts, preferably 0.5 part to 3.0 parts. If the amount of the silicone-based surfactant added is less than 0.1 part, it becomes difficult to form a non-adhesive structure of the fiber B and the elastic polymer, which will be described later, of the present invention during the water immersion solidification. Further, the addition amount of this silicone-based surfactant is 10
If the content exceeds the above range, the silicone-based surfactant is likely to leach out from the solidified elastic polymer, which may cause problems during post-processing when making artificial leather, or when working into products such as shoes and balls. .

The microporous sheet material of the present invention thus obtained has excellent properties as a base fabric for artificial leather, and the properties can be controlled widely and arbitrarily. Among the characteristics, the flexibility is 0.5 to 6.0, preferably 0.6 to
5.0, more preferably 0.7 to 3.0, and wear resistance is 1500 to 8000, preferably 1500 to 8000.
It is in the range of 5000. Desirably further, the microporous sheet material of the present invention has a 20% elongation stress of 1.0 to 8.
It has a value of 0, preferably 2.0 to 6.0, and a tear strength of 3 to 8, preferably 4 to 7. The microporous sheet material of the present invention has an apparent specific gravity of 0.2 to 6.
0 g / cm ^3, preferably in the range of 0.3 to 5.0 g / cm ^3, and has a relatively light tender texture.

The fact that the microporous sheet material of the present invention has a suitable balance of both flexibility and abrasion resistance as described above is because it is a non-woven fabric in which two different types of fibers are mixed. It is considered that this is due to the difference in the state in which the fibers are surrounded by the elastic polymer due to the use of the base cloth and the difference in the types of the fibers. That is, the fibers A are generally adhered (or bonded) surrounded by the elastic polymer, whereas the fibers A are generally non-adhesive (or unbonded) surrounded by the elastic polymer, where the fiber B is the fiber A with respect to the elastic polymer. It is considered that the above characteristics are exhibited by having more freedom than the above.

The microporous sheet material of the present invention has a portion in which fibers are adhered and surrounded by an elastic polymer and a portion in which they are not in contact with each other. It is possible to obtain a product having wide flexibility and other physical properties. The fact that the fibers are surrounded by the elastic polymer by adhesion or non-adhesion can be easily determined by observing the cross section of the microporous sheet-like object with a photograph taken with an electron microscope. The non-bonded (or non-bonded) state can be said to be a state in which the fibers are surrounded by the elastic polymer through the interfacial voids, and can be observed by the photograph. On the other hand, the state of being bonded and surrounded means that there is no interfacial void between the fiber and the elastic polymer.

The microporous sheet material of the present invention can be used as it is for various purposes. For example, it can be used as a base fabric for artificial leather itself, but a more substantial base fabric for artificial leather can be obtained by forming an elastic polymer layer on one side or both sides. To form this elastic polymer layer, a solution of the above-mentioned elastic polymer (which does not necessarily need to contain a silicone-based surfactant in the solution) is formed on the surface of the obtained microporous sheet material. It may be applied and dried, or wet solidification drying, or laminated using release paper. The thickness of the elastic polymer layer on this surface is usually 20 to 500 μm, preferably 30 to 300 μm.

[0028]

The present invention will be described in detail below with reference to specific examples. In the examples, "parts" and "%" are based on weight, and the characteristic measurement values were obtained by the following methods.

B. A flexibility test piece of 25 mm × 90 mm was prepared, and the lower 20 mm in the longitudinal direction was held vertically by a holder, and the holder 20
While bending the sample, slide and hold the holder so that the center of the U gauge at the height of 20 mm from the tip of the other end of the test piece hits the measuring portion of the U gauge. The stress after 5 minutes from reading is read from a recorder and converted into stress per 1 cm width, and the unit is expressed in g / cm as the flexibility (bending resistance). B. Elongation property The stress at 20% elongation is measured by a method according to the method of JIS-K6550, and converted to per 1 cm of width and expressed as Kg / cm as 20% elongation stress (this measuring method is ASTM
It corresponds to D2209). C. Abrasion resistance Measured according to the method according to JIS-L1096 C method (Taber type method), H22 is used as the abrasion wheel, and abrasion resistance is expressed by the number of times until all layers are abraded. ASTM
It corresponds to D4060). D. Tear strength It is measured by a method according to the measurement of the tear strength of JIS-K6550, and the unit is expressed in Kg (this measuring method is ASTM D
4704).

Example 1 Polyethylene terephthalate fiber (2.0 denier, cut length 51 mm, number of crimps 13 / 25.4 mm) 30%
And polypropylene fiber (2.0 denier, cut length 50
mm, crimp number 13 / 25.4 mm) 70%
Create a laminated web using cards and cross layers,
Depth of 7 mm, density of 700 needles / c due to the needle room equipped with a 40th needle with regular barbs
Punching of m ² was performed to obtain an entangled web. Then
Pressurized with a mirror-finished metal roll with a surface temperature of 130 ° C to a thickness of 1.
Nonwoven fabric-1 having 0 mm and a basis weight of 230 g / m ² was obtained.

On the other hand, 4,4'-diphenylmethane diisocyanate, polytetramethylene glycol having a molecular weight of 2000, polybutylene adipate having a terminal diol having a molecular weight of 1700, and diethylene glycol were polymerized in a dimethylformamide solution to give a 12% polyurethane. -A dimethylformamide solution, in which ethylene oxide is added as a silicone-based additive, a silicone oil (trade name: FG-10, manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., silicone segment 56%, ethylene oxide segment 46%, average molecular weight) About 4000)
Was added and mixed in an amount corresponding to 1.0 part with respect to 100 parts of polyurethane solid content to prepare an impregnating liquid-1. Next, the nonwoven fabric-1 is impregnated with the impregnating liquid-1, and the excess impregnating liquid on the front surface and the back surface is scraped off and immersed in an aqueous solution of 10% dimethylformamide to coagulate the polyurethane, which is then washed with water and dried. A leather substrate-1 was prepared.

The obtained artificial leather substrate-1 has a length of 1.0 m.
It had a thickness of m, a weight of 405 g / m ² , and the flexibility, elongation property, abrasion resistance, and tear strength were well balanced as artificial leather for shoes as shown in Table 1. In addition, as a result of observing the cross-sectional structure with an electron microscope, it was confirmed that a portion in which the polyurethane bonds the fibers and a portion in which the polyurethane exists between the fibers in a non-bonded state are mixed.

Comparative Example 1 Using the non-woven fabric-1 prepared in Example 1 as the non-woven fabric, a 12% polyurethane-dimethylformamide solution obtained by the polymerization reaction of Example 1 was added to a 12% ethylene oxide adduct of a higher aliphatic alcohol. (Sanyo Chemical Co., Ltd.
Nonipol SDH-90) made by Polyurethane solid content 1
An artificial leather substrate-2 was prepared in the same manner as in Example 1 by adding and mixing an amount corresponding to 1.0 part with respect to 00 parts to prepare and use as an impregnating liquid-2. The obtained artificial leather substrate-2 has a thickness of 1.0 mm and a weight of 400 g / m ² ,
It was very hard, and other properties were unbalanced as artificial leather. As a result of observing the cross-sectional structure with an electron microscope, it was possible to confirm the part where the polyurethane bonded the fibers, but not the part where the polyurethane existed in the non-bonded state between the fibers.

Comparative Example 2 Polyethylene terephthalate fiber (2.0 denier, cut length 51 mm, crimp number 13 / 25.4 mm) 90%
And polypropylene fiber (2.0 denier, cut length 50
mm, crimp number 13 / 25.4 mm) 10% mixed,
Create a laminated web using cards and cross layers,
Depth of 7 mm, density of 700 needles / c due to the needle room equipped with a 40th needle with regular barbs
Punching of m ² was performed to obtain an entangled web. Then
Pressurized with a mirror-finished metal roll with a surface temperature of 130 ° C to a thickness of 1.
0 mm, to obtain a nonwoven fabric -2 basis weight 230 g / m ^2.

The obtained non-woven fabric-2 was impregnated with the impregnating liquid-1 containing the silicone-based additive prepared in Example 1, and thereafter, the artificial leather substrate-3 was prepared by the same procedure as in Example-1. Created. The obtained artificial leather substrate-3 had a thickness of 1.0 mm and a weight of 405 g / m ² , was extremely hard, and had other properties unbalanced as an artificial leather. . As a result of observing the cross-sectional structure with an electron microscope, it was possible to confirm the portions where the polyurethane bonded the fibers, but the portions where the polyurethane existed in the non-bonded state between the fibers were scattered, and could hardly be confirmed.

Example 2 Polyethylene terephthalate fiber (2.0 denier, cut length 51 mm, crimp number 13 / 25.4 mm) was formed into a laminated web using a card and a cross layer, and a card and a cross layer were separately formed thereon. Polypropylene fiber (2.0 denier, cut length 5)
0 mm, 13 crimps / 25.4 mm) webs are laminated and punched at a depth of 7 mm and a density of 700 pieces / cm ² by a needle room equipped with a 40-count needle having a regular barb to obtain an entangled web. It was Then, it was pressed with a mirror-finished metal roll having a surface temperature of 130 ° C. to obtain a nonwoven fabric-3 having a thickness of 1.0 mm and a basis weight of 230 g / m ² . The obtained non-woven fabric-3 was impregnated with the impregnating liquid-1 containing the silicone-based additive prepared in Example 1, and thereafter the same procedure as in Example 1 was carried out to prepare an artificial leather substrate-4.

The obtained artificial leather substrate-4 has a thickness of 1.
It had a weight of 0 mm and a weight of 405 g / m ² , and the flexibility, elongation property, abrasion resistance, and tear strength were well balanced as artificial leather for shoes as shown in Table 1. As a result of observing the cross-sectional structure with an electron microscope, it is found that polyurethane is present in a non-bonded state between the fibers in the upper layer portion containing many polypropylene fibers, and polyurethane is bonded to the fiber in the lower layer portion containing many polyester fibers. It could be confirmed.

Example 3 Polyethylene terephthalate fiber (2.0 denier, cut length 51 mm, crimp number 13 / 25.4 mm) 50%
And 6-nylon fiber (2.0 denier, cut length 50m
m, 14 crimps / 25.4 mm) 50% mixed cotton, laminated web was made using card and cross layer, depth of 7 mm, density by needle room equipped with 40-count needle with regular barb 700 lines / cm
The punching of ² was performed and the confounding web was obtained. Then, pressurizing with a mirror-finished metal roll with a surface temperature of 130 ° C to a thickness of 1.0
Nonwoven fabric-4 having a weight of 230 mm and a basis weight of 230 g / m ² was obtained.

The obtained non-woven fabric-4 was impregnated with the impregnating liquid-1 containing the silicone-based additive prepared in Example 1, and thereafter the same operation as in Example 1 was carried out.
5 was created. The obtained artificial leather substrate-5 had a thickness of 1.0 mm and a weight of 400 g / m ² , and had flexibility, elongation characteristics, abrasion resistance, and tear strength as shown in Table 1. It was a well-balanced leather. In addition, as a result of observing the cross-sectional structure with an electron microscope, it was confirmed that a portion in which the polyurethane bonds the fibers and a portion in which the polyurethane exists between the fibers in a non-bonded state are mixed.

Comparative Example 3 Nonwoven fabric-1 prepared in Example 1 was treated with reactive silicone (H
A non-woven fabric-5 was prepared by treating with a 1% aqueous dispersion of silicone oil (Geranex SH manufactured by Matsumoto Yushi-Seiyaku Co., Ltd.) and drying. The obtained non-woven fabric-5 was impregnated with the impregnating liquid-1 containing the silicone-based additive prepared in Example 1, and thereafter, the same procedure as in Example 1 was carried out to prepare an artificial leather substrate-6. The obtained artificial leather substrate-6 has a thickness of 1.0 mm and a weight of 400 g / m ² and is very soft. However, as shown in Table 1, the artificial leather has other properties such as excessive elongation. As a result, it was unbalanced. In addition, as a result of observing the cross-sectional structure with an electron microscope, it was not possible to confirm the portion where the polyurethane bonded the fibers, and it was confirmed that the polyurethane existed in the non-bonded state between the fibers.

Example 4 Polyethylene terephthalate fiber (2.0 denier, cut length 51 mm, crimp number 13 / 25.4 mm) 60%
And polypropylene fiber (2.0 denier, cut length 50
mm, crimp number 13 / 25.4 mm) 40%
Create a laminated web using cards and cross layers,
Depth of 7 mm, density of 700 needles / c due to the needle room equipped with a 40th needle with regular barbs
Punching of m ² was performed to obtain an entangled web. Then
Pressurized with a mirror-finished metal roll with a surface temperature of 130 ° C to a thickness of 1.
Nonwoven fabric-5 having a weight of 0 mm and a basis weight of 230 g / m ² was obtained. On the other hand, in the 12% polyurethane-dimethylformamide solution prepared in Example 1, a silicone oil added with ethylene oxide as a silicone-based additive (trade name F
G-11, manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., silicone segment 46%, ethylene oxide segment 54%, average molecular weight about 1800) was added and mixed in an amount corresponding to 1.0 part based on 100 parts of polyurethane solid content. Liquid-3 was prepared. Then, the non-woven fabric-5 is impregnated with the impregnating liquid-3, and thereafter, the same operation as in Example 1 is performed to form a base material for artificial leather-
7 was created.

The obtained artificial leather substrate-7 had a thickness of 1.
It had a weight of 0 mm and a weight of 400 g / m ² , and the flexibility, elongation property, abrasion resistance, and tear strength were well balanced as artificial leather for shoes as shown in Table 1. In addition, as a result of observing the cross-sectional structure with an electron microscope, it was confirmed that a portion in which the polyurethane bonds the fibers and a portion in which the polyurethane exists between the fibers in a non-bonded state are mixed.

Example 5 Polyethylene terephthalate fiber (2.0 denier, cut length 51 mm, crimp number 13 / 25.4 mm) 20%
And polypropylene fiber (2.0 denier, cut length 50
mm, crimp number 13 / 25.4 mm) 80% mixed,
Create a laminated web using cards and cross layers,
Depth of 7 mm, density of 700 needles / c due to the needle room equipped with a 40th needle with regular barbs
Punching of m ² was performed to obtain an entangled web. Then
Pressurized with a mirror-finished metal roll with a surface temperature of 130 ° C to a thickness of 1.
Nonwoven fabric-6 having a weight of 0 mm and a basis weight of 230 g / m ² was obtained.

The obtained non-woven fabric-6 was impregnated with the impregnating liquid-3 containing the silicone-based additive prepared in Example 4, and thereafter the same operation as in Example 1 was carried out.
8 was created. The artificial leather substrate-8 thus obtained had a thickness of 1.0 mm and a weight of 405 g / m ² , and had flexibility, elongation characteristics, abrasion resistance, and tear strength as shown in Table 1 for artificial shoes. It was a well-balanced leather. In addition, as a result of observing the cross-sectional structure with an electron microscope, it was confirmed that the portion where the polyurethane bonds the fibers and the portion where the polyurethane exists in the non-bonded state between the fibers are mixed.

Example 6 Polyethylene terephthalate fiber (2.0 denier, cut length 51 mm, number of crimps 13 / 25.4 mm) 50%
And 6,6-nylon fiber (1.2 denier, cut length 38
mm, crimp number 13 / 25.4 mm) 50%,
Create a laminated web using cards and cross layers,
Depth of 5 mm and density of 850 needles / c due to the needle room equipped with a 40th needle with regular barbs
Punching of m ² was performed to obtain an entangled web. Then
Pressurized with a mirror-finished metal roll with a surface temperature of 130 ° C to a thickness of 1.
Nonwoven fabric-7 having 0 mm and a basis weight of 230 g / m ² was obtained.

Then, the nonwoven fabric-7 was impregnated with the impregnating liquid-3 prepared in Example 4, and thereafter the same procedure as in Example 1 was carried out to prepare a substrate 9 for artificial leather. The artificial leather base material 9 thus obtained had a thickness of 1.0 mm and a weight of 400 g / m ² , and the flexibility, elongation property, abrasion resistance, and tear strength were as shown in Table 1 for artificial shoes. It was a well-balanced leather. In addition, as a result of observing the cross-sectional structure with an electron microscope, it was confirmed that a portion in which the polyurethane bonds the fibers and a portion in which the polyurethane exists between the fibers in a non-bonded state are mixed.

Example 7 Polyethylene terephthalate fiber (2.0 denier, cut length 51 mm, crimp number 13 / 25.4 mm) 60%
And polyethylene fiber (1.5 denier, cut length 50m
m, 14 crimps / 25.4 mm) 40% mixed with each other, a laminated web was created using a card and a cross layer, and a depth of 6 mm and a density were obtained by a needle room equipped with a 40-count needle having a regular barb. 900 / cm
The punching of ² was performed and the confounding web was obtained. Then, pressurizing with a mirror-finished metal roll with a surface temperature of 130 ° C to a thickness of 1.0
A non-woven fabric-8 having a weight of 230 g and a basis weight of 230 g / m ² was obtained.

Then, the nonwoven fabric-8 was impregnated with the impregnating liquid-1 prepared in Example 1, and thereafter, the same procedure as in Example 1 was carried out to prepare a substrate 10 for artificial leather. The obtained artificial leather substrate-10 had a thickness of 1.0 mm and a weight of 400 g / m ² , and had flexibility, elongation characteristics, abrasion resistance, and tear strength as shown in Table 1. It was a well-balanced leather. In addition, as a result of observing the cross-sectional structure with an electron microscope, it was confirmed that a portion in which the polyurethane bonds the fibers and a portion in which the polyurethane exists between the fibers in a non-bonded state are mixed.

[0049]

[Table 1]

Claims (10)

[Claims] 1. A microporous sheet material obtained by impregnating and coagulating an elastic polymer into a non-woven fabric, wherein (1) the non-woven fabric comprises (a) aromatic polyester fibers (fiber A) and (b). ) A non-woven base fabric in which a polyolefin fiber or a polyamide fiber (fiber B) is mixed, (2) the microporous sheet-like article, (i) a portion in which the fiber A is adhesively surrounded by an elastic polymer and the fiber. B is interspersed with a portion surrounded by an elastic polymer in a non-adhesive state, and (ii) the degree of softness is 0.5 to 6.0, and (ii)
i) A microporous sheet material having an abrasion resistance of 1500 to 8000. 2. The microporous sheet material according to claim 1, wherein the mixing ratio of the fibers A and the fibers B is in the range of 70:30 to 5:95 by weight. 3. The microporous sheet material according to claim 1, wherein the non-woven base fabric is obtained by laminating a web made of the fibers A and a web made of the fibers B and performing inter-fiber entanglement treatment. 4. A substrate for artificial leather having the microporous sheet according to claim 1 and an elastic polymer layer on at least one surface thereof. 5. The elastic polymer layer has a thickness of 20 to 500 μm.
The artificial leather substrate according to claim 4, having a thickness of 5. 6. A method for producing a microporous sheet material by impregnating a non-woven fabric with an organic polar solvent solution of an elastic polymer, and then coagulating the solution in a coagulation bath mainly comprising water, wherein (1) ) As the non-woven fabric, a non-woven fabric in which polyester fibers (fiber A) and polyolefin fibers or nylon fibers (fiber B) are mixed is used, and (2) water-dispersible or water-soluble as the organic polar solution. A microporous sheet-like product characterized by using a solution in which 0.1-10 parts by weight of a surfactant having a silicone segment as a hydrophobic group is dissolved per 100 parts by weight of the elastic polymer solid. Manufacturing method. 7. The method for producing a microporous sheet according to claim 6, wherein the surfactant contains 10 to 90% by weight of a silicone segment. 8. The method for producing a microporous sheet according to claim 6, wherein the surfactant is substantially formed of a polyalkylene oxide segment and a silicone segment. 9. The microporous sheet material according to claim 6, wherein the surfactant contains a polyalkylene oxide segment and a silicone segment, and the ratio thereof is in the range of 10:90 to 90:10 by weight. Production method. 10. The non-woven base fabric comprises the fiber A and the fiber B.
The method for producing a microporous sheet-like product according to claim 6, wherein the blending ratio of the above is in the range of 70:30 to 5:95 by weight.