JPH03192132A - Production of microporous elastomer film - Google Patents

Abstract

PURPOSE:To produce a microporous film improved in waterproofness and gas transmissive property by feeding a film comprising a thermoplastic elastomer composition to the space between a heating roll and an elastic roll in such a way that a specified (non)woven fabric is applied to the film on the side of the heating roll and heating it under pressure. CONSTITUTION:A thermoplastic elastomer composition comprising, for example, 30-70wt.% ethylene/vinyl acetate copolymer and 70-30wt.% ethylene/propylene/ diene copolymer or polyurethane elastomer is kneaded and molded to obtain a film of a thickness of 10-40mum. This film is fed to the space between a heating roll heated to 100 deg.C or below and an elastic roll at a feed rate of 2-30m/min in such a way that a (non)woven fabric containing 40-200cc/m<2> of a mixture of water with optionally an alcohol is applied to the film on the side of the heating roll and heated to 100 deg.C or higher under a pressure of 0.1-5kg/cm<2> to obtain the title film.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing a microporous elastomer film having waterproofness and breathability. The present invention relates to a method for producing a good microporous elastomer film.

[Conventional technology]

BACKGROUND ART In recent years, waterproof and breathable sheets or films have become widely used as leak-proof sheets for disposable diapers and the like, and as materials for sportswear.

Such breathable films are generally made into a film by kneading inorganic fillers with polyolefin resin and melt-molding the mixture.
It is manufactured by making it porous through -axial or biaxial stretching. In such a breathable film, fine fractures occur starting from the inorganic filler due to stretching, thereby forming pores with a pore size of about 1 to 4 μm.

However, such breathable films not only do not have sufficient air permeability, but also have stiffness peculiar to stretched films.
There is a problem in that it has a crisp paper-like feel and is not suitable for applications that require a soft feel.

In addition, a method of manufacturing a flexible porous film by adding the same kind of low melting point polymer, rubbery polymer, olefin thermoplastic elastomer, etc. to polyolefin resin along with an inorganic filler has been proposed, but the air permeability is not sufficient. In addition, there was a problem that the film strength was poor.

For this reason, various proposals have been made to impart flexibility to stretched breathable films made of polyolefin resins and inorganic fillers. For example, JP-A-60-257221 discloses 100 parts by weight of polyolefin resin and 25 to 400 parts of filler.
A composition consisting of 1 to 100 parts by weight of a liquid or waxy hydrocarbon polymer, or a mixture of the hydrocarbon polymer and an epoxy group-containing organic compound is melt-extruded, and the resulting film is molded into two wheels. Discloses a method for producing a porous film with excellent flexibility by stretching.

In addition, JP-A-62-10141 discloses polyolefin resin,
A method for producing a porous film or sheet is disclosed, which comprises stretching a film or sheet obtained by melt-molding a composition containing a filler and a triglyceride.

Further, JP-A No. 62-27438 discloses a method for producing a breathable film by stretching in at least one direction a film made of a composition of 42 to 87 volume % of a polyolefin resin and 58 to 13 volume % of an inorganic filler. The polyolefin resin is a mixture of 50 to 95% by weight of straight low density polyethylene and 50 to 5% by weight of branched low density polyethylene, and the composition contains a fatty acid having 10 to 22 carbon atoms and 1 to 22 carbon atoms. The aliphatic alcohol fatty acid ester, which is a compound with the aliphatic alcohol of No. 12, is added to the above composition 1.
This disclosure discloses a method for producing a breathable film, characterized in that 3 to 25 parts by weight are blended with respect to 00 parts by weight.

Furthermore, Japanese Patent Publication No. 63-35721 discloses a liquid-impermeable leak-proof sheet for diapers that is integrally formed by overlaying it with an absorbent material, containing 100 parts by weight of polyolefin resin and 28 parts by weight of filler
~200 parts by weight, and 10 to 70 parts by weight of a liquid or waxy polyhydroxy saturated hydrocarbon produced by hydrogenating a hydroxyl-terminated liquid polybutadiene. After kneading and forming a film, It discloses a film that has been stretched by 1.2 times or more to create micropores.

[Problem to be solved by the invention]

However, since all of the above breathable films are obtained by stretching, they are thin and have poor mechanical strength.
It is often necessary to use it in conjunction with other materials. Therefore, secondary processing is required, which has the disadvantage of increasing the price.

As a result of various studies, the inventors of the present invention have found that a stretched film of a composition comprising a crystalline polyolefin, a rubbery polymer, and a filler is hot-pressed onto a mesh-like sheet at a temperature equal to or higher than the thermal contraction start temperature of the stretched film. discovered that by fixing the stretched film and heat-shrinking it, thereby making the stretched film microporous, it is possible to obtain a breathable composite film that is soft to the touch and has high mechanical strength, We would like to propose a method for manufacturing such a breathable composite film in JP-A-64-
No. 14023).

The above-mentioned breathable composite film has an excellent soft feel and also has excellent mechanical strength and air permeability. but,
As a result of subsequent research, the method of hot-pressing woven or non-woven fabrics and making use of the shrinkage of the elastomer film to make it microporous is affected by the weave condition of the woven or non-woven fabric.
It has been found that the sizes of the through holes are not uniform, and for this reason, the waterproofness and breathability are not necessarily satisfactory.

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

[Means to solve the problem]

As a result of intensive research in view of the above object, the present inventors formed a film from a composition containing an ethylene-vinyl acetate copolymer (E! By moistening the woven or nonwoven fabrics to be laminated and applying hot pressure, the film becomes uniformly microporous to obtain a microporous elastomer film with good waterproofness and breathability, and the obtained microporous film. It was discovered that the material properties were maintained, and the present invention was conceived.

That is, in the first method of producing a microporous elastomer film of the present invention, a film made of a thermoplastic elastomer composition is placed between a roll heated to 100°C or higher and an elastic roll, and water or water is placed on the heated roll side. It is characterized in that the film is made microporous by supplying it through a woven fabric or non-woven fabric moistened with a mixture of water and alcohol and applying heat and pressure.

A second method for producing the microporous elastomer film of the present invention is to laminate a film made of a thermoplastic elastomer composition and a woven fabric or nonwoven fabric, and to immerse the woven fabric or nonwoven fabric of the laminate in water or water+alcohol. The film is characterized in that, after being moistened with the liquid mixture, the film is supplied between a roll heated to 100° C. or higher and an elastic roll, and then heated and pressed to make the film microporous.

The present invention will be explained in detail below.

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

In the present invention, the thermoplastic resin is not particularly limited, but it is preferable to use ethylene-vinyl acetate copolymer (BV^) from the viewpoint of film moldability and the like.

In the present invention, a thermoplastic elastomer is a polymeric material that exhibits rubber elasticity at room temperature, but becomes plasticized and moldable at high temperatures, and can be processed in the same manner as ordinary thermoplastic resins. .

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 xfL/non-propylene copolymer (EPR), polyurethane elastomers, polyester elastomers, polyamide elastomers, Examples include polystyrene elastomers, chlorinated polyethylene elastomers, and polyvinyl chloride.

Thermoplastic elastomer compositions are composed of various combinations of thermoplastic resins and the above-mentioned thermoplastic elastomers, but in the present invention, a thermoplastic elastomer composition (A) containing a polymer (BPOM), ■ a thermoplastic elastomer composition (B) containing an ethylene-vinyl acetate copolymer (BV^) and a polyurethane elastomer, ■ a thermoplastic elastomer composition A thermoplastic elastomer composition (C) in which one or more thermoplastic elastomers selected from a polyester elastomer, a polyamide elastomer, and a polyurethane elastomer are added to the material (A), and (1) a thermoplastic elastomer composition ( A thermoplastic elastomer composition (D) in which a polyester elastomer and/or a polyamide elastomer is added to B)
) It is preferable to use an elastomer composition made of a combination of the following.

ME Elastomer Composition (A) Ethylene-vinyl acetate copolymer (EV^) used in the present invention
) has a content of vinyl acetate repeating units of 7.5% by weight.
This is a copolymer of the above. In particular, in the present invention, it is preferable to use an ethylene-vinyl acetate copolymer having a content of vinyl acetate repeating units 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
℃, 2.16 kg load).

In the present invention, the above ethylene-vinyl acetate copolymer (B
The blending ratio of V^) is the thermoplastic elastomer composition (A)
The content is preferably 30 to 70% by weight, particularly preferably 40 to 60% by weight. If the blending ratio of the above ethylene vinyl acetate copolymer (EV^) is lower than 30% by weight,
The moldability decreases, and if it exceeds 70% by weight, the elongation of the elastomer film becomes insufficient.

In the present invention, ethylene-propylene-diene copolymer (BPDM) refers to a copolymer containing repeating units derived from ethylene, repeating units derived from propylene, and repeating units derived from a diene compound. . Examples of the diene compounds include ethylidene norbornene, 1,4-hexadiene, and dicyclopentadiene.

The ethylene-propylene-diene copolymer (BPDM) 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%. %,
The content of repeating units derived from the diene compound is preferably 1 to 10 mol%. More preferable ranges are 62 to 66 mol% of the ethylene derivative, 33 to 37 mol% of the propylene derivative, 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/crI or less is preferable.

Furthermore, melt index (190℃, 2.16kg
A copolymer having a load) in the range of 0.1 to 5.0 g/10 minutes is preferable, more preferably 0.30 to 1.0 g/10 minutes.
1O min, more preferably 0.35 to 0.5'O
g/10 min.

The ethylene-propylene-diene copolymer (BPDM) used in the present invention basically consists of the above-mentioned repeating units, but within the range that does not impair the properties of these copolymers, for example, butene- Other repeating units such as repeating units derived from α-olefins such as 1- or 4-methylpentene-1 may also be included.

In the present invention, the blending ratio of the ethylene-propylene-diene copolymer (EPDM) in the thermoplastic elastomer composition (A) is 30 to 70% by weight, particularly 40 to 70% by weight.
It is preferably within the range of 60% by weight.

The above ethylene-propylene-diene copolymer (BPDM
) If the blending ratio is lower than 30% by weight, the elongation of the film will be insufficient, and the adhesiveness of the formed film will increase, making it difficult to handle. On the other hand, if it exceeds 70% by weight, moldability decreases.

Thermoplastic elastomer composition ω) In the thermoplastic elastomer composition ω), ethylene-
As the vinyl acetate copolymer (0VA), the same one as in the above-mentioned thermoplastic elastomer composition (A) can be used.

Furthermore, in the present invention, polyurethane elastomer basically refers to a polymer base consisting of 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 glycol as a hard segment. A polymer whose soft segment is a polymer chain consisting of a chain polyol.

Examples of the short chain glycols include ethylene glycol, propylene glycol, 1,4-butynediol, bisphenol A, etc., and examples of the long chain polyols include polyethers such as polyalkylene glycol, polyalkylene adipate, polycaprolactone, polycarbonate, etc. Examples include polyester. As the polyisocyanate, diisocyanates such as 4.4''-diphenylmethane diisocyanate and hexamethylene 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. Also, the melt viscosity at 190°C is 8000-10
000 poise is preferable.

In the present invention, the blending ratio of the polyurethane elastomer in the thermoplastic elastomer composition (B) is 30 to 70% by weight, particularly 40 to 70% by weight, as in the case of the ethylene-propylene-diene copolymer (BPDM) described above. It is preferably within the range of 60% by weight.

If the blending ratio of the polyurethane elastomer is lower than 30% by weight, the elongation of the film will be insufficient and the adhesiveness of the formed film will increase, making it difficult to handle. On the other hand, if it exceeds 70% by weight, moldability decreases.

In the present invention, other thermoplastic elastomers may be blended into 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 (0) This thermoplastic elastomer composition (C) is a mixture of the thermoplastic elastomer composition (A) and one or more of a polyester elastomer, a polyamide elastomer, and a polyurethane elastomer. It is.

In the present invention, the polyester elastomer is a multi-block polymer in which a hard segment is a high melting point, highly crystalline aromatic polyester, and a soft segment is a rubbery polymer with a low glass transition point (Tg). As the hard segment of the polyester elastomer, polybutylene terephthalate is mainly used, and as the soft segment, aliphatic polyether or aliphatic polyester is used.

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

Furthermore, melt index (230℃, 2.16kg
A copolymer with a load) within the range of 5 to 20 g/10 minutes is preferable, and a copolymer with a load of 7 to 15 g/10 minutes is more preferable.

In the present invention, the polyamide elastomer is a polymer in which polyamide is used for the hard segment and polyester or polyether is used for the soft segment.

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

-f-C-PA-C-OPB-0... (1) (In the formula, PA represents a polyamide group, PR represents a polyethylene group, and n represents a positive integer.) As the above polyamide are polyamide 6, polyamide 6-6, polyamide 11
．． Polyamide 12 or the like can be used. Further, as the polyether, polyoxyethylene, polyoxypropylene, polyoxytetramethylene, etc. can be used.

The above polyether amide can be obtained, for example, by condensation polymerization of a low molecular weight polycarboxylic acid polyamide in a molten state and an oligomer of dihydroxy polyether.

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

(In the formula, P^ represents a polyamide group, and plq represents a positive integer.) As the polyamide in F, the same polyether amide as described above can be used.

The above polyester amide is generally produced in two stages: production of polyamide oligomer and increase in molecular weight by esterification, in order to adjust the molecular weight of the oligomer and increase the molecular weight by creating polyether diol bonds. It can be obtained by polycondensation using dicarboxylic acid under high temperature conditions.

The above polyamide elastomer has a molding temperature range of 1
A temperature of about 50 to 230°C is preferable.

Furthermore, melt index (230℃, 2.16kg
Load) is preferably within the range of 1 to 20 g/10 minutes, more preferably 1 to Log/10 minutes.

In the present invention, the same polyurethane elastomer as the above-mentioned thermoplastic elastomer (B) can be used.

According to the present invention, the blending ratio of the thermoplastic elastomer composition (A) and the polyester elastomer, polyamide elastomer, and polyurethane elastomer is 40 to 60 parts by weight, preferably 45 to 60 parts by weight of the thermoplastic elastomer (A). 55 parts by weight, and each of the above elastomers accounts for 60 to 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 depending on the properties required of the film. In this case, the blending amount may be such that the total amount of each thermoplastic elastomer falls within the range of the above-mentioned blending ratio of the thermoplastic elastomers.

Thermoplastic Elastomer Composition (D) The thermoplastic elastomer composition (D) is a mixture of the thermoplastic elastomer composition (B) with a polyester elastomer and/or a polyamide elastomer.

The above-mentioned thermoplastic elastomer composition (0) can be used as the polyester elastomer and polyamide elastomer.

The blending ratio of the thermoplastic elastomer composition (B) and the polyester elastomer and/or polyamide elastomer is 40% of the thermoplastic elastomer (B).
-60 parts by weight, preferably 45-55 parts by weight, and the elastomer contains 60-40 parts by weight, preferably 55-55 parts by weight.
It is 45 parts by weight.

In addition, in the thermoplastic elastomer composition (D), an ethylene-propylene-diene copolymer (εPDM) can also be used as the thermoplastic elastomer to be blended, but in this case, the above-mentioned thermoplastic elastomer composition (
Included in 0.

In the present invention, the above-mentioned thermoplastic elastomer (A
) to (D) may be blended with low-density polyethylene for the purpose of improving the moldability of the film.

In the present invention, the low density polyethylene is generally 0.9
It has a density of 10 to 0.930 g/c+j, and is an ethylene homopolymer or 95 mol% ethylene.
It is a random or block copolymer with other α-olefins containing the above. The melt index (Ml) of low density polyethylene is 1 to 20 g/10 minutes, preferably 5 to 20 g/10 minutes.
15g/10 minutes.

The blending ratio of such low density polyethylene is 100% of each of thermoplastic elastomer compositions (A) to (D).
In terms of parts by weight, it is 1 to IO parts by weight. If the proportion of low-density polyethylene is less than 1 part by weight, the effect of its blending will not be sufficient, and if it exceeds 10 parts by weight, the properties as an elastomer film will be impaired.

The preferred blending ratio of low density polyethylene is 3 to 6 parts by weight.

In other car inventions, in addition to the above-mentioned components, other resins 1, antioxidants,
Various compounding agents such as ultraviolet absorbers, antistatic agents, and coloring agents can be appropriately blended.

Next, the method for manufacturing the microporous elastomer film of the present invention will be explained.

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

The above-mentioned ethylene-vinyl acetate copolymer (BVA), ethylene-propylene-diene copolymer (E!PDM) or polyurethane elastomer and various thermoplastic elastomers, low density polyethylene and other components added as necessary. Knead. Note that the above-mentioned kneading may be appropriately set according to the melting point and blending ratio of the thermoplastic elastomer, and -
For boat fishing, it is preferable to use resin at a temperature of 140 to 180°C.

After kneading, it is formed into a film. The thickness of the film is preferably 10 to 40 μm; if it is thinner than 10 μm, the film strength will decrease, and if it is thicker than 40 μm, it will be difficult to form fine through holes for providing ventilation. The film is formed using the inflation molding method (air cooling method) at a blow ratio (
Diameter of rose pull/diameter of die slit) is 2°0~5.
It is preferable to do this so that the value is within the range of 0. The temperature at this time is also appropriately set depending on the melting point of the thermoplastic elastomer, etc. The thickness of the film obtained by this is 10 to 40 μm
becomes.

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

Various woven or nonwoven fabrics can be used in the present invention, such as gauze or other plain woven fabrics, or nonwoven fabrics produced by spunbonding, melt blowing, or the like. The nonwoven fabric does not need to be made of long fibers, and may be made of short fibers intertwined or point welded. Moreover, it may be either hydrophilic or non-hydrophilic. It is preferable that the woven fabric or nonwoven fabric does not melt or shrink due to heat during the hot pressing process described below.

As the aqueous solution, water or an alcohol mixed solution containing 70% by volume or more of water can be used. In addition, the content of the aqueous solution in woven or nonwoven fabric is 40 to 200%.
cc/m' is preferable; less than 40 cc/m' results in a smaller amount of through holes formed, and 200 cc/m'
'', it takes too long to boil during hot pressurization.

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

Moreover, it is preferable that the said hot pressurization is performed at the pressure of 0.1-5 kg/cat. If it is less than 0.1 kg/ct1, the heat transfer effect will not be sufficient, and if it is less than 5 kg/ct1, the heat transfer effect will not be sufficient.
If it exceeds af, the film strength will decrease. More preferred pressure conditions are 0.5-2 kg/caf.

Further, the film feeding speed is preferably 2 to 30 m/min. If the feed speed is less than 2 m/min, the film will be heated excessively, which will easily damage the properties of the material.
If the speed exceeds m/min, the aqueous solution contained in the woven or nonwoven fabric will boil, making it difficult to form micropores sufficiently.

The elastic roll to be paired with the heat roll is not particularly limited, but one having a rubber mesh-like material such as silicone rubber on its surface is preferable. Further, in order to facilitate peeling of the film, the surface temperature of the roll is preferably 30° C. or lower.

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

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

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

Next, the obtained film and woven fabric or non-woven fabric are laminated.

Lamination of the film and the woven fabric 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 onto the woven or nonwoven fabric of the laminate thus obtained. As the aqueous solution, the same one as in the first method described above may be used. The content is also the same as in the first manufacturing method described above.

Subsequently, hot pressurization 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, even if a non-woven fabric or woven fabric is laminated on a film in advance, it is moistened, and then heat and pressure is applied, if the moist non-woven fabric or woven fabric is interposed between the hot roll and the film. Similarly, fine through holes can be uniformly distributed on the film surface.

The microporous elastomer film thus obtained generally has a microporous diameter of 10. ca or less, and has excellent breathability and waterproofness.

Moreover, in the production method of the present invention, if conditions such as film feeding speed, temperature, and amount of aqueous solution sprayed are constant,
It also has the advantage that the distribution of micropores hardly changes, and a uniform film can be easily produced.

[For production]

In the manufacturing method of the present invention, the woven fabric or nonwoven fabric interposed or laminated on the film is moistened and hot pressurized, so that fine through holes are uniformly distributed.

The reason for this effect is not necessarily clear, but water boils and evaporates instantaneously during hot pressurization, and these fine water particles collide with the film at high speed and penetrate the film. This is thought to be due to the formation of pores. therefore,
By adjusting the temperature of the hot roll, the feeding speed of the film, the amount of water sprinkled on the woven or nonwoven fabric, etc., the amount of water particles can be changed, thereby making it possible to obtain a desired distribution of through holes.

〔Example〕

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

This device includes a heating roll 2 for heating a film 1, a looped endless belt 3 made of woven or nonwoven fabric, a spray device 4 for applying moisture to the endless belt, a nip roll 5, and a guide roll 6. .6°
, 6°°, an elastic roll 7, a cooling roll 8 that cools the elastic roll 7, a tray 9 that applies cooling water to the cooling roll, and an auxiliary roll that adjusts the amount of cooling water adhering to the elastic roll 7. 10, and a group of rolls 111. for guiding the film.
112.113.

As mentioned above, the temperature of the heating roll 3 needs to be 100°C or higher, preferably within the range of 110 to 135°C, and is appropriately set depending on the type and thickness of the woven fabric or nonwoven fabric. Further, the gap between the heating roll 3 and the elastic roll 7 can be adjusted as appropriate so as to apply a desired pressure to each. Further, it is preferable that the elastic roll 1 is cooled to maintain a temperature of 30° C. or lower.

Further, the spraying of the aqueous solution is efficient if, as in this example, a larger amount than the desired amount is first sprayed, and then the desired amount is contained by squeezing the solution using a nip roll or the like.

The amount of dispersion into woven or nonwoven fabric is 40 to 200 cc/
Specifically, the pressure of Nituprole may be set within the range of 0.1 to 1 kg/cd in order to obtain rn''.

In addition, in the second method of the present invention, a film and a laminated sheet of woven or nonwoven fabric are set at the location of film l in FIG. 1, and the endless belt 3 is removed.
Hot pressurization is sufficient.

In this case, if the woven fabric or nonwoven fabric is laminated on only one side of the film, the elastic roll is similarly cooled to 30° C. or less, but if it is laminated on both sides, there is no need to cool it.

The method of the present invention will be explained in more detail with reference to the following specific examples.

Example 1 Ethylene-propylene-diene copolymer [Vistaron 3708, Exxon Chemical Special 360% by weight and ethylene-vinyl acetate copolymer [vinyl acetate content 28% by weight,
Melt index (Ml, 190℃, 2.16kg
Load) 20 g/10 minutes] 40% by weight was melt-kneaded using an extruder, and a film was formed using an inflation method under the following conditions.

Gui diameter...100m Die temperature...165℃ Extrusion amount...28kg/hour Pickup speed: 20nn/min The resulting film had a thickness of 25 μm.

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

Heat roll temperature: 115℃ Film feed speed: ・5m/min Nip roll pressure: ・3 kg/ca! Amount of water sprayed: 40 cc/m'' A nonwoven fabric (rayon nonwoven fabric) with a basis weight of 50 g/m'' was used for the endless belt interposed between the heat roll and the film.

The porous film thus obtained has moisture permeability,
Breathability and waterproofness were measured.

The results are shown in Table 1.

The moisture permeability, air permeability, and waterproofness were measured as follows.

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

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

The measuring device shown in FIG. 2 includes a cup part 21, a cylindrical part 22, a side pipe 23 provided on the side of the cylindrical part 22, a rubber stopper 24 for sealing the lower end of the cylindrical part, and a cylindrical part 22. A packing 25 is provided above the side tube 23 in the middle of the shaped portion 22 at a location where the inner diameter of the tube is 5 crl in area.

In such a device, ■ insert the film 1 into the packing 25, and insert the film 1 into the cup part 2;
1 is filled with ethanol to a height of 30 mm from the bottom (H in the figure).

■ 0.01kg/cffI of helium gas from the side pipe 23
distributed under pressure. (Arrow in the figure) ■Measure the time (seconds) until the total amount of bubbles passing through the film reaches 100-.

Perform the experiment using the following steps. The number of seconds was taken as the air permeability.

Note that if the film has too few or no through holes, it will balloon and break. This case was indicated as "destruction".

(3) Waterproofness: In the above breathability test, the leakage of ethanol from the film when the supply of helium gas was stopped was evaluated as follows.

◎...No leakage at all.

○: Slight leakage is observed.

×...Leakage is significant.

Example 2 A composition consisting of 50% by weight of the composition of Example 1, 45% by weight of polyester elastomer [manufactured by Toyobo ■, Perpreni P30B], and 5% by weight of low density polyethylene was melt-kneaded using an extruder, A film was formed by the inflation method under the following conditions.

Die diameter...100m111 Die temperature...185℃ Extrusion amount...26kg/hour Pickup speed: 15m/min The thickness of the obtained film was 30 μm.

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

The porous film thus obtained has moisture permeability,
Breathability and waterproofness were measured.

The results are shown in Table 1.

Example 3 50% by weight of the composition of Example 1 and a polyurethane elastomer [manufactured by Nippon Polyurethane Industry ■, P22MRNA]
T] A composition consisting of 45% by weight and 5% by weight of low density polyethylene was melt-kneaded using an extruder and formed into a film by an inflation method under the following conditions.

Gui diameter...100ml11 Gui temperature...175℃ Extrusion amount...26kg/hour Pickup speed: 15m/min The thickness of the obtained film was 40 μm.

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

The porous film thus obtained has moisture permeability,
Breathability and waterproofness 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 with a thickness of 250 mm.

Moisture was sprinkled on the obtained composite sheet under the following conditions.

Nip roll pressure: 0.5 kg/cd Water spray amount: 200 CC/m' Subsequently, in the apparatus shown in FIG. 1, the endless belt was removed and hot pressurization was carried out under the following conditions.

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

The results are shown in Table 1.

Example 5 Ethylene-vinyl acetate copolymer [vinyl acetate content 28
Weight%, melt index (M1% 190℃, 2.1
6kg load) 20g/10 minutes] 40% by weight, and polyurethane elastomer [manufactured by Nippon Polyurethane Industries ■, P
22MRNAT] A composition consisting of 60% by weight was melt-kneaded using an extruder, and a film was formed using an inflation method under the following conditions.

Gui diameter...100m+* Die temperature...185℃ Extrusion amount...24kg/hour Pick-up speed: 15m/min The thickness of the obtained film was 35 μm.

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

The porous film thus obtained has moisture permeability,
Breathability and waterproofness 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 its moisture permeability, air permeability, and waterproofness were measured.

The results are shown in Table 1.

Comparative Example 2 A film that was not subjected to hot pressing in Example 1,
A polyester spunpond nonwoven fabric having a basis weight of 30 g/rn'' was hot-pressed under the following conditions using an apparatus having two hot-pressing rolls.

First hot crimping roll...120-130°C Second hot crimping roll...100-120°C crimping speed...
...5 to 10 m/min The moisture permeability, air permeability, and waterproofness of the obtained composite sheet 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 waterproof properties. On the other hand, the film of Comparative Example 1, which used a film that was not subjected to hot pressing, was not made porous, and the film of Comparative Example 2, which was made microporous using the heat shrinkage of the film, It wasn't waterproof enough. This is comparative example 2
This is thought to be because although the film is porous, it does not have a sufficiently uniform pore size.

〔Effect of the invention〕

The microporous film produced by the method of the present invention is produced by forming a film from a thermoplastic elastomer composition and hot pressing it through a wet woven or nonwoven fabric, so that the film becomes uniformly microporous. The film has good waterproofness and breathability.

Furthermore, the resulting porous film is not exposed to excessively high temperatures during its manufacturing process, so the material properties of the elastomer are maintained.

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

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of an apparatus for carrying out the method of the present invention. FIG. 2 is a schematic diagram showing an apparatus used for measuring waterproofness and breathability. 2 ・ 3 ・ 4 ・ 5 ・ 6.6', 6' ・ 7 ・ 8 ・ 9 ・ lO・Cooling roll・Support plate・Auxiliary roll Roll group 21・22・23・24・25・・Cup part・Cylindrical part・Side pipe・Rubber stopper・Packing Figure 1 Applicant: Tonen Petrochemical Co., Ltd.

Claims (6)

[Claims] (1) A film made of a thermoplastic elastomer composition is placed between a roll heated to 100°C or higher and an elastic roll, and the woven or nonwoven fabric is moistened with water or a mixture of water and alcohol on the heating roll side. 1. A method for producing a microporous elastomer film having waterproofness and breathability, characterized in that the film is made microporous by supplying the film through a heat-pressing method. (2) After laminating a film made of a thermoplastic elastomer composition and a woven or nonwoven fabric, and moistening the woven or nonwoven fabric of the laminate with water or a mixed solution of water and alcohol,
A method for producing a microporous elastomer film having waterproofness and breathability, characterized by making the film microporous by supplying the film between a roll heated to 0° C. or higher and an elastic roll and applying heat and pressure. . (3) The method according to claim 1 or 2, wherein the thermoplastic elastomer composition contains 30 to 70% by weight of an ethylene-vinyl acetate copolymer and 70 to 70% by weight of an ethylene-propylene-diene copolymer or a polyurethane elastomer. 30
% by weight of a microporous elastomer film. (4) The method according to claim 1 or 2, 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. Production of a microporous elastomer film characterized by containing 60 to 40 parts by weight of one or more selected from polyester elastomers, polyamide elastomers, and polyurethane elastomers based on a total of 40 to 60 parts by weight. Method. (5) The method according to claim 1 or 2, wherein the thermoplastic elastomer is an ethylene-vinyl acetate copolymer 3
0-70% by weight and polyurethane elastomer 70-3
A method for producing a microporous elastomer film, characterized in that it contains 60 to 40 parts by weight of a polyester elastomer and/or a polyamide elastomer to a total of 40 to 60 parts by weight including 0% by weight. (6) In the method according to any one of claims 1 to 5, 1 to 100 parts by weight of the thermoplastic elastomer.
A method for producing a microporous elastomer film, comprising 10 parts by weight of low density polyethylene.