JP2839923B2 - Method for producing microporous elastomer film - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a microporous elastomer film having waterproofness and air permeability, and particularly to a method in which fine through-holes are uniformly distributed, and thus waterproofness and air permeability. The present invention relates to a method for producing a microporous elastomer film having a good quality.

[Conventional technology]

In recent years, a sheet or film having waterproofness and air permeability has been widely used as a material for leakproof sheets such as disposable diapers and sportswear.

Such a breathable film is generally manufactured by kneading a polyolefin resin with an inorganic filler, melt-molding the film, forming a film, and making the film porous by uniaxial or biaxial stretching. In such a breathable film, stretching causes fine breakage starting from the inorganic filler, thereby forming pores having a pore diameter of about 1 to 4 μm.

However, such a breathable film not only has insufficient breathability but also has a crisp paper-like feel due to the inherent rigidity of the stretched film, and is used in applications where a soft feeling is required. There is a problem that is not suitable.

In addition, a method of producing a flexible porous film by adding a low-melting polymer of the same type, a rubbery polymer, an olefin-based thermoplastic elastomer, and the like together with an inorganic filler to a polyolefin resin has been proposed, but air permeability is not sufficient. In addition, there is a problem that the film strength is inferior.

For this reason, various proposals have been made to impart flexibility to a stretched breathable film comprising a polyolefin resin and an inorganic filler. For example, Japanese Patent Application Laid-Open No. 60-257221 discloses a polyolefin resin 100 parts by weight, a filler 25 to 400 parts by weight, a liquid or waxy hydrocarbon polymer, or a mixture of the hydrocarbon employee and an epoxy group-containing organic compound. Disclosed is a method for producing a porous film having excellent flexibility by melt-extrusion of a composition consisting of 部 100 parts by weight and subjecting the obtained film to biaxial stretching.

Japanese Patent Application Laid-Open No. 62-10141 discloses a method for producing a porous film or sheet, comprising stretching a film or sheet obtained by melt-molding a composition containing a polyolefin resin, a filler and triglyceride. doing.

JP-A-62-27438 discloses polyolefin-based resins 42-8.
A method for producing a breathable film by stretching a film comprising a composition of 7% by volume and 58 to 13% by volume of an inorganic filler in at least a uniaxial direction, wherein the polyolefin resin is a linear low-density polyethylene of 50 to 95%. % Of a branched low-density polyethylene and 50 to 5% by weight of a branched low-density polyethylene, and the composition is composed of a fatty acid having 10 to 22 carbon atoms and an aliphatic alcohol having 1 to 12 carbon atoms. Disclosed is a method for producing a breathable film, which comprises blending 3 to 25 parts by weight of a fatty acid ester with respect to 100 parts by weight of the composition.

Furthermore, Japanese Patent Publication No. 63-35721 discloses a liquid-impermeable leak-proof sheet in which absorbents are laminated and formed integrally for disposable diapers. A composition comprising 10 to 70 parts by weight of a liquid or waxy polyhydroxy saturated hydrocarbon produced by hydrogenation is kneaded,
It discloses a film formed into a film and stretched at least 1.2 times in at least one direction to form micropores.

[Problems to be solved by the invention]

However, since any of the above-mentioned breathable films are obtained by stretching, they are thin and have poor mechanical strength, and often need to be used in combination with other materials. For this reason, secondary processing is required, and there is a disadvantage that the price is increased.

Therefore, the present inventors have conducted various studies, and hot-pressed a stretched film of a composition comprising a crystalline polyolefin, a rubber-like polymer and a filler to a mesh sheet at a temperature equal to or higher than the heat shrinkage initiation temperature of the stretched film. By fixing and stretching the stretched film and heat shrinking, and thereby making the stretched film microporous, it is possible to obtain a breathable composite film having a soft feel and a large mechanical strength, A method for producing such a breathable composite film was proposed (Japanese Patent Laid-Open No. 64-64).
14023).

The breathable composite film has an excellent soft feeling and also has excellent mechanical strength and breathability. However, as a result of subsequent research, the method of hot pressing with a woven or nonwoven fabric and making it microporous using shrinkage of the elastomer film is affected by the weaving condition of the woven or nonwoven fabric, It has been found that the size is not uniform and, for this, the waterproofness and the breathability are not always satisfactory.

Accordingly, an object of the present invention is to provide a method for producing a microporous elastomer film having fine through holes and thus having excellent waterproofness and air permeability.

[Means for solving the problem]

As a result of intensive studies in view of the above objects, the present inventors have formed a film from a composition containing an ethylene-vinyl acetate copolymer (EVA) and a thermoplastic elastomer, and interposed or laminated the film. By moistening the cloth or non-woven fabric and applying hot pressure, the non-uniformity becomes microporous uniformly, and a microporous elastomer film with good waterproofness and air permeability can be obtained. And found the present invention.

That is, the first method of producing the microporous elastomer film of the present invention, a film made of a thermoplastic elastomer composition, between a roll heated to 100 ° C. or more and an elastic roll, water or water on the heating roll side The film is supplied through a woven or non-woven fabric moistened with a mixed solution of water and alcohol, and is heated and pressurized to make the film microporous.

Further, a second method for producing the microporous elastomer film of the present invention comprises laminating a film made of a thermoplastic elastomer composition and a woven or nonwoven fabric, and forming the woven or nonwoven fabric of the laminate with water or water + alcohol. After moistening with a liquid mixture, the film is supplied between a roll heated to 100 ° C. or higher and an elastic roll, and is also subjected to heat pressurization, thereby making the film microporous.

 The present invention will be described in detail below.

In the present invention, the thermoplastic elastomer composition forming a film is composed of a thermoplastic resin and a thermoplastic elastomer.

In the present invention, the thermoplastic resin is not particularly limited, but from the viewpoint of film formability and the like, ethylene-
It is preferred to use a vinyl acetate copolymer (EVA).

In the present invention, the thermoplastic elastomer is a polymer material which exhibits rubber elasticity at normal temperature, but is plasticized at high temperature and can be molded, and can be processed in the same manner as a normal thermoplastic resin. . Such thermoplastic elastomers are usually copolymers consisting of various combinations of soft and hard segments.

Examples of the thermoplastic elastomer include olefin elastomers such as ethylene-propylene-diene copolymer (EPDM) and ethylene-propylene copolymer (ERP), polyurethane elastomer, polyester elastomer, polyamide elastomer, polystyrene elastomer, Chlorinated polyethylene elastomers, polyvinyl chloride and the like can be mentioned.

The thermoplastic elastomer composition is composed of various combinations of a thermoplastic resin and the above-mentioned thermoplastic elastomer. In the present invention, ethylene-vinyl acetate copolymer (EVA) and ethylene-vinyl acetate copolymer are used.
A thermoplastic elastomer composition (A) containing a propylene-diene copolymer (EPDM), a thermoplastic elastomer composition (B) containing an ethylene-vinyl acetate copolymer (EVA) and a polyurethane elastomer, Thermoplastic elastomer composition (C) obtained by adding one or more thermoplastic elastomers selected from polyester-based elastomer, polyamide-based elastomer and polyurethane-based elastomer to thermoplastic elastomer composition (A), and thermoplastic elastomer composition It is preferable to use an elastomer composition obtained by combining the thermoplastic elastomer composition (D) obtained by adding a polyester elastomer and / or a polyamide elastomer to the product (B).

Thermoplastic elastomer composition (A) Ethylene-vinyl acetate copolymer (EV) used in the present invention
A) is a copolymer having a vinyl acetate repeating unit content of 7.5% by weight or more. In particular, in the present invention, it is preferable to use an ethylene-vinyl acetate copolymer having a vinyl acetate repeating unit content in the range of 7.5 to 30% by weight.

The melt index of the ethylene-vinyl acetate copolymer used in the present invention is usually 0.2 to 25 g / 10 minutes (190 ° C., 2.16 kg
Load).

In the present invention, the blending ratio of the ethylene-vinyl acetate copolymer (EVA) is 30 to 70% by weight in the thermoplastic elastomer composition (A), and is particularly preferably in the range of 40 to 60% by weight. When the blending ratio of the ethylene-vinyl acetate copolymer (EVA) is lower than 30% by weight, the moldability decreases, and when it is higher than 70% by weight, the elongation of the elastomer film becomes insufficient.

In the present invention, ethylene-propylene-diene copolymer (EPDM) is a repeating unit derived from ethylene,
It is a copolymer containing a repeating unit derived from propylene and a repeating unit derived from a diene compound. Examples of the diene compound include ethylidene norbornene, 1,4-hexadiene, and dicyclopentadiene.

The ethylene-propylene-diene copolymer (EPDM) used in the present invention has a content of repeating units derived from ethylene of 60 to 70 mol% and a content of repeating units derived from propylene of 30 to 40 mol. % And the content of the repeating unit derived from the diene compound is from 1 to 10
Preferably it is mol%. A more preferred range is that the ethylene derivative is 62 to 66 mol% and the propylene derivative is 33 to 66 mol%.
37 mol%, and 3 to 6 mol% of the diene compound derivative.

The number average molecular weight is preferably 400,000 to 600,000, and the density is 0.87 g /
cm ² or less is preferred.

In addition, melt index (190 ° C, 2.16kg load)
Is preferably in the range of 0.1 to 5.0 g / 10 minutes,
The copolymer is more preferably in the range of 0.30 to 1.0 g / 10 minutes, and still more preferably in the range of 0.35 to 0.50 g / 10 minutes.

The ethylene-propylene-diene copolymer (EPDM) used in the present invention is basically composed of the above-mentioned repeating units. However, as long as the properties of these copolymers are not impaired, for example, butene- Other repeating units such as repeating units derived from α-olefins such as 1 or 4-methylpentene-1 may be included.

In the present invention, the blending ratio of the ethylene-propylene-diene copolymer (EPDM) is 30 to 70% by weight in the thermoplastic elastomer composition (A), particularly 40 to 60% by weight.
Is preferably within the range. When the blending ratio of the ethylene-propylene-diene copolymer (EPDM) is lower than 30% by weight, the elongation of the film is insufficient, and the adhesiveness of the formed film increases, which makes handling difficult. On the other hand, if it exceeds 70% by weight, the moldability will decrease.

Thermoplastic Elastomer Composition (B) In the thermoplastic elastomer composition (B), the same ethylene-vinyl acetate copolymer (EVA) as the above-mentioned thermoplastic elastomer composition (A) can be used.

In the present invention, the polyurethane-based elastomer is basically a polymer chain comprising a polyisocyanate having two or more isocyanate groups and a short-chain glycol as a hard segment, and a polyisocyanate having two or more isocyanate groups and a long chain. It is a polymer having a polymer chain composed of a polyol as a soft segment. Examples of the short-chain glycol include ethylene glycol, propylene glycol, 1,4-butenediol, and bisphenol A. Examples of the long-chain polyol include polyethers such as polyalkylene glycol, polyalkylene adipate, polycaprolactone, and polycarbonate. Polyester. As the polyisocyanate, diisocyanates such as 4,4'-diphenylmethane diisocyanate and hexanemethylene diisocyanate are mainly used.

The polyurethane elastomer used in the present invention preferably has a molding temperature in the range of about 150 to 190 ° C. Further, those having a melt viscosity at 190 ° C. of about 8,000 to 10,000 poise are preferred.

In the present invention, the blending ratio of the polyurethane-based elastomer in the thermoplastic elastomer composition (B) is 30 to 70% by weight as in the case of the above-mentioned ethylene-propylene-diene copolymer (EPDM), and is particularly preferably 40 to 70% by weight. Preferably, it is within the range of 60% by weight. If the mixing ratio of the polyurethane-based elastomer is lower than 30% by weight, the elongation of the film is insufficient, and the tackiness of the formed film becomes large, which makes handling difficult. On the other hand, if it exceeds 70% by weight, the moldability will decrease.

In the present invention, another thermoplastic elastomer can be blended with the above-mentioned thermoplastic elastomer composition (A) and thermoplastic elastomer composition (B) for the purpose of improving the elongation and heat shrinkability of the film. .

Thermoplastic elastomer composition (C) This thermoplastic elastomer composition (C) is obtained by blending one or more of a polyester elastomer, a polyamide elastomer and a polyurethane elastomer with the thermoplastic elastomer composition (A). Things.

In the present invention, the polyester-based elastomer is a multi-block polymer using a high melting point and high crystalline aromatic polyester for the hard segment and a rubbery polymer having a low glass transition point (Tg) for the soft segment. Polybutylene terephthalate is mainly used as the hard segment of the polyester-based elastomer, and aliphatic polyether or aliphatic polyester is used as the soft segment.

The polyester elastomer preferably has a molding temperature in the range of about 160 to 230 ° C.

In addition, melt index (230 ° C, 2.16kg load)
Is preferably in the range of 5 to 20 g / 10 minutes,
More preferably, the copolymer is in the range of 7 to 15 g / 10 minutes.

In the present invention, the polyamide-based elastomer is a polymer in which a hard segment is made of polyamide and a soft segment is made of polyester or polyether.

Among the above-mentioned polyamide-based elastomers, examples of those using polyether as the soft segment include those represented by the following general formula (1).

(Where PA represents a polyamide group, PE represents a polyethylene group, and n represents a positive integer.) As the polyamide, polyamide 6, polyamide 6-6, polyamide 11, polyamide 12, or the like may be used. it can. As the polyether, polyoxyethylene, polyoxypropylene, polyoxytetramethylene, or the like can be used.

The polyether amide can be obtained, for example, by polycondensing a low-molecular-weight polycarboxylic acid polyamide in a molten state with an oligomer of dihydroxy polyether.

Examples of the soft segment using polyester include those represented by the following general formula (2).

(In the formula, PA represents a polyamide group, and p and q represent positive integers.) As the polyamide, the same polyamide as the above-mentioned polyether polyamide can be used.

The polyester amide is generally produced in two stages, that is, the production of a polyamide oligomer and the production of a high molecular weight by esterification. In order to control the molecular weight of the oligomer and to produce a polyether diol bond, the polyester amide is produced. It can be obtained by polycondensation using a dicarboxylic acid under high temperature conditions.

The polyamide-based elastomer has a molding temperature range of
Those having a temperature of about 150 to 230 ° C are preferred.

In addition, melt index (230 ° C, 2.16kg load)
Is preferably in the range of 1 to 20 g / 10 minutes, more preferably in the range of 1 to 10 g / 10 minutes.

In the present invention, the same polyurethane elastomer as that of the thermoplastic elastomer (B) described above can be used.

In the present invention, the thermoplastic elastomer composition (A)
The mixing ratio of the polyester-based elastomer, polyamide-based elastomer and polyurethane-based elastomer is such that the thermoplastic elastomer (A) is 40 to 60 parts by weight, preferably 45 to 55 parts by weight, and each of the above elastomers is 60 to 60 parts by weight.
It is 40 parts by weight, preferably 55 to 45 parts by weight.

In the present invention, two or more of the above-mentioned thermoplastic elastomers can be used in combination according to the characteristics required for the film. In this case, the compounding amount may be such that the total amount of the respective thermoplastic elastomers falls within the range of the mixing ratio of the thermoplastic elastomer.

Thermoplastic elastomer composition (D) The thermoplastic elastomer composition (D) is obtained by blending a polyester elastomer and / or a polyamide elastomer with the thermoplastic elastomer composition (B).

The above-mentioned thermoplastic elastomer composition (C) can be used as the polyester-based elastomer and the polyamide-based elastomer.

The mixing ratio of the thermoplastic elastomer composition (B) and the polyester elastomer and / or polyamide elastomer is such that the thermoplastic elastomer (B) is 40%.
エ ラ ス ト マ ー 60 parts by weight, preferably 45-55 parts by weight, and the elastomer is 60-40 parts by weight, preferably 55-45 parts by weight.

In the thermoplastic elastomer composition (D),
Ethylene-propylene-diene copolymer (EPDM) can be used as the thermoplastic elastomer to be blended, but in this case, it is included in the above-mentioned thermoplastic elastomer composition (C).

In the present invention, low-density polyethylene can be blended with each of the thermoplastic elastomers (A) to (D) for the purpose of improving the moldability of the film.

In the present invention, low-density polyethylene is generally 0.91
It has a density of 0 to 0.930 g / cm ³ , and is a homopolymer of ethylene or other α containing 95 mol% or more of ethylene.
-Random or block copolymers with olefins. The low density polyethylene has a melt index (MI) of 1 to 20 g / 10 minutes, preferably 5 to 15 g / 10 minutes.

The mixing ratio of such low-density polyethylene is such that each of the thermoplastic elastomer compositions (A) to (D) is 100%.
As a part by weight, it is 1 to 10 parts by weight. If the proportion of the low-density polyethylene is less than 1 part by weight, the effect of the compounding is not sufficient, and if it exceeds 10 parts by weight, the properties as an elastomer film are impaired. A preferable mixing ratio of the low-density polyethylene is 3 to 6 parts by weight.

In the present invention, in addition to the above-described components, other resins, an antioxidant, an ultraviolet absorber, an antistatic agent, and various compounding agents such as a coloring agent are appropriately added for the purpose of improving the properties of the film. be able to.

Next, a method for producing the microporous elastomer film of the present invention will be described.

First, the method for producing the first microporous film of the present invention will be described.

The above-mentioned components such as ethylene-vinyl acetate copolymer (EVA), ethylene-propylene-diene copolymer (EPDM) or polyurethane-based elastomer and various thermoplastic elastomers and low-density polyethylene added as needed are kneaded. . Note that the above kneading may be appropriately set according to the melting point and the mixing ratio of the plastic elastomer, and generally,
It is preferably carried out at a resin temperature of 140 to 180 ° C.

After kneading, it is formed into a film. The thickness of the film is preferably from 10 to 40 μm. If the thickness is less than 10 μm, the film strength is reduced. If the thickness is more than 40 μm, it is difficult to form fine through holes for providing air permeability. The film is preferably formed by an inflation molding method (air cooling method) so that the blow ratio (the diameter of the bubble / the diameter of the die slit) is in the range of 2.0 to 5.0. The temperature at this time is appropriately set according to the melting point of the thermoplastic elastomer and the like. This results in a film thickness of 10 to 40 μm.

The film thus obtained is supplied between the heating roll and the elastic roll via a woven or nonwoven fabric moistened with an aqueous solution to the heating roll side, and is heated and pressed.

As the woven fabric or nonwoven fabric used in the present invention, various types of fabrics such as gauze or other plain woven fabrics and nonwoven fabrics manufactured by a spun bond method, a melt blow method, or the like can be used. The nonwoven fabric does not need to be made of long fibers, but may be made of short fibers entangled or spot welded. It may be either hydrophilic or non-hydrophilic. It is preferred that the woven or nonwoven fabric does not melt or shrink in the following hot pressing step.

As the aqueous solution, water or an alcohol mixed solution containing 70% by volume or more of water can be used. The content of the aqueous solution in the woven or nonwoven fabric is preferably 40 to 200 cc / m ² . If it is less than 40 c / m ² , the amount of through-holes formed will be small, and if it exceeds 200 cc / m ² , it will take too long for the resin to boil into a hot pressurized resin.

In the present invention, hot pressing of the film is performed at 100 ° C. or higher. If the temperature is lower than 100 ° C., the aqueous solution contained in the woven or nonwoven fabric does not boil, and the through-holes are not sufficiently formed.

The hot pressing is preferably performed at a pressure of 0.1 to 5 kg / cm ² . If it is less than 0.1 kg / cm ² , the heat transfer effect is not sufficient, and if it exceeds 5 kg / cm ² , the film strength decreases.
More preferred pressure conditions are 0.5-2 kg / cm ² .

Further, the feeding speed of the film is preferably 2 to 30 m / min. If the feed speed is less than 2 m / min, the film is excessively heated and the properties of the material tend to be impaired.If it exceeds 30 m / min, the microporosity is sufficiently formed by the boiling of the aqueous solution contained in the woven or nonwoven fabric. It becomes difficult.

The elastic roll forming a pair with the heat roll is not particularly limited, but is preferably provided with a rubber mesh such as silicone rubber on the surface. The surface temperature of the roll is preferably set to 30 ° C. or lower in order to facilitate the peeling of the film.

Under such conditions, by interposing a moist nonwoven fabric or woven fabric between the hot roll and the film, fine through-holes can be uniformly distributed on the film surface.

Next, the second method for producing a microporous film of the present invention will be described.

In the second production method of the present invention, the steps up to the production of the film are performed in the same manner as in the first production method described above.

Next, the obtained film and a woven or nonwoven fabric are laminated. The lamination of the film with a woven or nonwoven fabric may be performed by a normal lamination method such as a dry lamination method or a wet lamination method.

An aqueous solution is sprayed on the woven or nonwoven fabric of the laminate thus obtained. As the aqueous solution, the same solution as in the first method described above may be used. The content is also the same as in the above-mentioned first production method.

Subsequently, hot pressing is performed. The temperature of the hot roll is the same as the temperature of the hot roll in the first manufacturing method described above.

In this way, a non-woven fabric or a woven fabric is laminated on the film in advance, and after moistening it,
Fine through-holes can be evenly distributed on the film surface as in the case where a moist nonwoven fabric or woven fabric is interposed between the heat roll and the film.

The microporous diameter of the microporous elastomer film thus obtained is generally 10 μm or less, and has excellent air permeability and excellent waterproofness. Moreover, in the production method of the present invention, if the conditions such as the feed speed of the film, the temperature, and the spray amount of the water diameter solution are constant, the distribution of the microporous hardly changes, and a uniform film can be easily produced. It also has the advantage of being able to.

(Operation)

In the production method of the present invention, the woven or nonwoven fabric to be interposed or laminated on the film is wet-pressed, so that fine through-holes are uniformly distributed.

The reason why such an effect is obtained is not clear, but water instantaneously boils and evaporates during hot pressurization,
It is considered that these fine water particles collide with the film at a high speed and form through holes on the film. Therefore, by adjusting the temperature of the heat roll, the film feed speed, and the amount of water sprayed on the woven or nonwoven fabric, the amount of water particles changes, and the distribution of the through-holes can be made desired. it can.

〔Example〕

FIG. 1 shows an example of an apparatus suitable for performing hot pressing in the first manufacturing method of the present invention.

This apparatus comprises a heating roll 2 for heating a film 1
An endless belt 3 made of a woven or nonwoven fabric in a loop, a spray device 4 for applying moisture to the endless belt, a nip roll 5 and guide rolls 6, 6 ',
6 ″, an elastic roll 7, a cooling roll 8 for cooling the elastic roll 7, a tray 9 for applying cooling water to the cooling roll,
It has an auxiliary roll 10 for adjusting the amount of cooling water attached to the elastic roll 7, and roll groups 111, 112, 113 for guiding a film.

The temperature of the heating roll 3 needs to be 100 ° C. or higher as described above, and is preferably in the range of 110 to 135 ° C.
It is set appropriately according to the type and thickness of the woven or nonwoven fabric. Further, the gap between the heating roll 3 and the elastic roll 7 can be appropriately adjusted so as to apply a desired pressure. It is preferable that the elastic roll 7 is cooled so as to keep the temperature at 30 ° C. or lower.

Further, spraying of the aqueous solution is efficient if the desired amount is contained by first spraying a larger amount than the desired amount and then squeezing the solution using a nip roll or the like as in this embodiment. The dispersion amount of the woven or nonwoven fabric to a 40~200cc / m ^2, specifically 0.1~1kg pressure nip roll / c
m ² .

In the second method of the present invention, a film,
What is necessary is just to set the laminated sheet of the woven or non-woven fabric at the position of the film 1 in FIG. 1, remove the endless belt 3, and apply hot pressing.

In this case, when a woven or nonwoven fabric is laminated on only one side of the film, the elastic roll is similarly cooled to 30 ° C. or lower, but when laminated on both sides, cooling is not necessary.

The method of the present invention is described in more detail by the following specific examples.

Example 1 Ethylene-propylene-diene copolymer [Vistalone
3708, Exxon Chemical Co., Ltd.]
Vinyl acetate copolymer [vinyl acetate content 28% by weight, melt index (MI, 190 ° C, 2.16kg load) 20g / 10min] 4
0% by weight of the composition was melt-kneaded by an extruder,
The film was formed by the inflation method under the following conditions.

 Die diameter: 100 mm Die temperature: 165 ° C. Extrusion amount: 28 kg / hour Take-off speed: 20 m / min The obtained film had a thickness of 25 μm.

This film was hot-pressed by the apparatus shown in FIG. 1 under the following conditions.

Heat roll temperature: 115 ° C Film feed speed: 5 m / min Nip roll pressure: 3 kg / cm ³ Amount of water dispersion: 40 cc / m ² Endless belt interposed between the heat roll and the film Used was a nonwoven fabric (rayon nonwoven fabric) having a basis weight of 50 g / m ² .

The moisture permeability, air permeability and waterproofness of the porous film thus obtained were measured.

 The results are shown in Table 1.

The measurement of moisture permeability, air permeability, and waterproofness was performed as follows.

(1) Moisture permeability: expressed by a value measured according to JIS-Z-0208.

(2) Air permeability: measured using the apparatus shown in FIG. 2 as follows.

The measuring device shown in FIG. 2 has a cup portion 21, a cylindrical portion 22,
A side tube 23 provided on a side portion of the cylindrical portion 22, a rubber stopper 24 sealing a lower end of the cylindrical portion, and an inner diameter of the tube above the side tube 23 at an intermediate portion of the cylindrical portion 22 And a packing 25 provided at a position where the pressure is 5 cm ² .

In such an apparatus, the film 1 is inserted into the packing 25, and the cup portion 21 is filled with ethanol up to a height of 30 mm (H in the figure) from the bottom thereof.

Helium gas is allowed to flow from the side pipe 23 at a pressure of 0.01 kg / cm ² . (The arrow in the figure) The time (second) until the total amount of bubbles passing through the film becomes 100 ml is measured.

Perform the experiment according to the following procedure. The number of seconds was defined as the air permeability.

If the film has too few or no through holes, it becomes balloon-like and breaks. This case was indicated as "destruction".

(3) Waterproofness: In the above-described breathability test, the following evaluation was made based on the leakage of ethanol from the film when the supply of helium gas was stopped.

 ◎ ・ ・ ・ No leakage at all.

 ・ ・ ・: Slight leakage is observed.

 X: Leakage is remarkable.

Example 2 50% by weight of the composition of Example 1 and 45% by weight of a polyester elastomer [Perpleni P30B manufactured by Toyobo Co., Ltd.]
And a low-density polyethylene of 5% by weight were melt-kneaded by an extruder and formed into a film by an inflation method under the following conditions.

 Die diameter: 100 mm Die temperature: 185 ° C. Extrusion amount: 26 kg / hour Take-off speed: 15 m / min The obtained film had a thickness of 30 μm.

This film was hot pressed under the same conditions as in Example 1.

The moisture permeability, air permeability and waterproofness of the porous film thus obtained were measured.

 The results are shown in Table 1.

Example 3 50% by weight of the composition of Example 1 and a polyurethane elastomer [P22MRNAT, manufactured by Nippon Polyurethane Industry Co., Ltd.] 45
A composition consisting of 5% by weight of a low-density polyethylene and 5% by weight of a low-density polyethylene was melt-kneaded by an extruder, and a film was formed by an inflation method under the following conditions.

 Die diameter: 100 mm Die temperature: 175 ° C. Extrusion amount: 26 kg / hour Take-off speed: 15 m / min The obtained film had a thickness of 40 μm.

This film was hot pressed under the same conditions as in Example 1.

The moisture permeability, air permeability and waterproofness of the porous film thus obtained were measured.

 The results are shown in Table 1.

Example 4 The film of Example 1 and a rayon fiber nonwoven fabric were laminated by a wet method to obtain a composite sheet having a thickness of 250 μm.

 Water was sprayed on the obtained composite sheet under the following conditions.

Nip roll pressure: 0.5 kg / cm ² Amount of water dispersion: 200 cc / m ² Subsequently, in the apparatus shown in FIG. 1, the endless belt was removed and hot pressing was performed under the following conditions.

Heat roll temperature: 115 ° C. Film feed speed: 5 m / min The moisture permeability, air permeability and waterproofness of the porous film thus obtained were measured.

 The results are shown in Table 1.

Example 5 Ethylene-vinyl acetate copolymer [vinyl acetate content 28
An extruder comprising a composition consisting of 40% by weight, a melt index (MI, 190 ° C., 2.16 kg load), 20 g / 10 minutes), 40% by weight, and a polyurethane elastomer [P22MRNAT, manufactured by Nippon Polyurethane Industry Co., Ltd.] 60% by weight , And formed into a film by the inflation method under the following conditions.

 Die diameter: 100 mm Die temperature: 185 ° C. Extrusion amount: 24 kg / hour Take-off speed: 15 m / min The obtained film had a thickness of 35 μm.

This film was hot pressed under the same conditions as in Example 1.

The moisture permeability, air permeability and waterproofness of the porous film thus obtained were measured.

 The results are shown in Table 1.

Comparative Example 1 The film obtained in Example 1 was used as it was without making it porous, and the moisture permeability, air permeability and waterproofness were measured.

 The results are shown in Table 1.

Comparative Example 2 The film which was not subjected to hot pressing in Example 1 and a polyester spun-pound nonwoven fabric having a basis weight of 30 g / m ² were hot pressed under the following conditions by an apparatus having two hot pressing rolls. .

First hot pressing roll: 120 to 130 ° C Second hot pressing roll: 100 to 120 ° C Pressing speed: 5 to 10m / min For the obtained composite sheet The moisture permeability, air permeability and prevention were measured.

 The results are shown in Table 1.

As is clear from the results in Table 1, the porous film obtained by the method of the present invention has excellent moisture permeability, air permeability and waterproofness. In contrast, the film of Comparative Example 1 using a film that was not subjected to hot pressing was not porous,
Comparative Example 2 in which the film was made microporous using heat shrinkage of the film
Was not sufficiently waterproof. This is considered to be because the film of Comparative Example 2 was porous, but did not have a sufficiently uniform pore size.

[Effect of the Invention] Since the microporous film according to the method of the present invention forms a film from the thermoplastic elastomer composition and is hot-pressed through a woven or nonwoven fabric moistened with the film, the film is uniformly formed. It is made microporous to form a film having good waterproofness and air permeability. In addition, the resulting porous film is not exposed to an excessively high temperature during the manufacturing process, so that the material properties of the elastomer are maintained.

Furthermore, in the production method of the present invention, if the conditions such as the feed rate of the film, the temperature, and the amount of the aqueous solution sprayed are constant, the distribution of the microporous hardly changes, and a uniform film can be easily produced. Therefore, it is also excellent in terms of manufacturing efficiency.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of an apparatus for performing the method of the present invention. FIG. 2 is a schematic diagram showing an apparatus used for measuring waterproofness and air permeability. DESCRIPTION OF SYMBOLS 1 ... Film 2 ... Heating roll 3 ... Endless belt 4 ... Spray device 5 ... Nip roll 6, 6 ', 6 "... Guide roll 7 ... Elastic roll 8 ... Cooling roll 9 ... Receiving tray 10 ... … Auxiliary rolls 111,112,113… Roll group 21… Cup part 22… Cylindrical part 23… Between sides 24… Rubber stopper 25… Packing

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ identification code FI // B29K 105: 04 B29L 7:00 (58) Field surveyed (Int.Cl. ⁶ , DB name) C08J 9/00-9 / 02 C08J 9/12-9/14 C08J 9/22-9 / 244,9 / 30 B29C 44/00-44 / 54,67 / 20

Claims (6)

(57) [Claims] 1. A woven fabric comprising a film made of a thermoplastic elastomer composition wetted between a roll heated to 100 ° C. or higher and an elastic roll on the side of the heated roll with water or a mixture of water and alcohol. Alternatively, a method for producing a waterproof and breathable microporous elastomer film, characterized in that the film is microporous by being supplied through a nonwoven fabric and subjected to heat and pressure. 2. A film comprising a thermoplastic elastomer composition and a woven or nonwoven fabric are laminated, and the woven or nonwoven fabric of the laminate is moistened with water or a mixture of water and alcohol, and then heated to 100 ° C. or higher. A method for producing a waterproof and air-permeable microporous elastomer film, characterized in that the film is microporous by supplying between a heated roll and an elastic roll and applying heat and pressure. 3. The method according to claim 1, wherein the thermoplastic elastomer composition comprises 30 to 70% by weight of an ethylene-vinyl acetate copolymer, an ethylene-propylene-diene copolymer or a polyurethane elastomer. A method for producing a microporous elastomer film, comprising 70 to 30% by weight. 4. The method according to claim 1, wherein the thermoplastic elastomer composition comprises 30 to 70% by weight of an ethylene-vinyl acetate copolymer and 70 to 30% by weight of an ethylene-propylene-diene copolymer. And a total of 40 to 60 parts by weight of a polyester elastomer, a polyamide elastomer and a polyurethane elastomer.
A method for producing a microporous elastomer film, comprising 60 to 40 parts by weight of a seed or two or more kinds. 5. The method according to claim 1, wherein the thermoplastic elastomer comprises 30 to 70% by weight of an ethylene-vinyl acetate copolymer and 70 to 30% of a polyurethane elastomer.
% Of the polyester-based elastomer and / or polyamide-based elastomer with respect to 40 to 60 parts by weight of
A method for producing a microporous elastomer film, characterized in that the content is from 40 to 40 parts by weight. 6. The microporous elastomer film according to claim 1, further comprising 1 to 10 parts by weight of low-density polyethylene based on 100 parts by weight of said thermoplastic elastomer. Manufacturing method.