JPS5968343A - Method for manufacturing breathable film - Google Patents

Abstract

PURPOSE:To obtain an air-permeable film useful for clothing, packaging, sanitary supplies, etc., by dispersing a vinyl chloride resin obtd. by drying an emulsion-polymerized or a fine suspension-polymerized polymer emulsion or suspension, in water, melting, a coating film of the resulting aq. dispersion by heating and cooling the film. CONSTITUTION:A vinyl chloride resin having an average particle size of 50mu or below obtd. by drying an emulsion-polymerized or a fine suspension-polymerized polymer emulsion or suspension, and a plasticizer are dispersed in water. This dispersion is applied onto a subtrate having a surface release property to form a coating film. Then the film is molten by heating at a temp. not higher than that represented by the formula (wherein Tg is a glass transition point of vinyl chloride resin, and the number of parts of plasticizer added is that of the plasticizer to be added per 100pts.wt. vinyl chloride resin) and cooled to obtain an air-permeable film.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a breathable film, and more particularly, to a method for producing a soft and breathable film based on a vinyl chloride resin. It is.

Techniques for manufacturing microporous separators for storage batteries, pseudo-leather, etc. using vinyl chloride resin as a base include Tokkosho,
? Publication No. 9-23g3g, Special Publication Sho'IO-! i23 No. 2 Publication, Special Public Shogu! -5g Publication No. 1, Special Publication Sho'l5-37
G77 Publication, Special Publication Shota Otsu-25ng Publication, Special Publication Sho Guar/1.9g'1 Publication, Special Publication Showa 4/-7-G59
'% S Publication, Special Publication No. 6 U 3.5-703,
A method described in Japanese Patent Publication No. 33-/9g7 has been proposed, and some of the methods have been put into practical use.

Among these already proposed methods, a method using a composition containing a base vinyl chloride resin and a plurality of plasticizers as a raw material is disclosed in Japanese Patent Publication No. 39-23g! ig issue, special public show '70-, t2
3. There is a method described in Publication No. 3.

However, by the methods described in these publications, the thickness can be reduced to 0.
It is difficult to produce an extremely thin and flexible film with a thickness of around 111 m.

In this situation, the inventors of the present invention believe that it can be used for clothing, packaging, household goods, etc., with a thickness of around 0/mm.
With the aim of providing an industrially advantageous method for producing a soft breathable film, the present invention has been completed as a result of intensive study.

The gist and first feature of the present invention is that a polymer emulsion obtained by an emulsion polymerization method or a fine suspension polymerization method is dried, and the average particle size is 3-0 microns or less. A vinyl resin is dispersed in water together with a plasticizer, and this dispersion is applied to a substrate (1) having release properties to form a coating 11Q. 1 kan is converted into the following formula (1), that is, Tg-1-(/3O-jl] number of parts of plasticizer added)... (1) [In formula (I), Tg is the glass transition of the hinyl chloride-based fat. The number of parts of plasticizer added means the number of parts of plasticizer added to 700 parts by weight of vinyl chloride-based material. The problem lies in the film manufacturing method.

The present invention will be explained in detail below.

What is vinyl chloride resin in the present invention? It means polyvinyl chloride and a copolymer mainly composed of vinyl chloride. Monomers copolymerizable with vinyl chloride, vinyl esters, vinyl ethers, acrylic acid or methacrylic acid and esters thereof, maleic acid or fumar and esters thereof, maleic anhydride, aromatic vinyl compounds, Examples include halogenated vinylitine compounds, acrylonitrile, methacrylonitrile, ethylene, and propylene.

Adding a trace amount of a compound containing a polyfunctional group to these monomers,
It may be partially crosslinked.

The vinyl chloride resin used is one produced by emulsion polymerization or microsuspension polymerization. The vinyl chloride resins produced by these methods have small average particle diameters and are suitable for producing breathable films.

According to the present invention, the vinyl chloride resin emulsion produced by the above method is dried to form a powder, and this powder is used.

When the resin emulsion obtained by the emulsion polymerization method is dried, for example, by spray drying, a large number of microparticles with an average particle size of 2 microns or less aggregate, and porous particles with an average particle size of S microns to 10 microns are formed. Fine suspension polymerization method (Thus, the average particle diameter of the Sensin resin obtained is 20 to 40 microns, and the resin is either 0 particles or aggregates together when dried. The agglomeration property is not as strong as that produced by the emulsion polymerization method.

According to the present invention, among the dried vinyl chloride resin powders, those having an average particle size of 50 microns or less are used. If the average particle size is SO micron or more, the final (
(It is important to properly adjust the strength and air permeability of the resulting film, and it is not possible to stably obtain a film with balanced properties.The air permeability of the final film depends on the vinyl chloride type 8J used. It varies depending on the average particle size of the fat.Vinyl chloride resins can be selected from those with an average particle size of 50 microns or less and s microns or more. Depending on the air permeability, strength, and feel of the breathable film, you can choose from a variety of options, such as one or two types, a single resin (homopolymer), or a copolymer resin.

If the misfire occurs, use the vinyl chloride-based ml fat powder,
Sprinkle with a plasticizer to absorb the plasticizer into the cyclized vinyl powder.

Plasticizers that can be removed include phthalate esters such as dioctyl phthalate, dibenzyl phthalate, butylbenzyl phthalate, dibenzyl phthalate, dioctyl phthalate, dioctyl phthalate, dioctyl phthalate; dioctyl adipate, dianopinate -Aliphatic dibasic acid esters such as butyl and dibutyl sebacate; Pentaerythrite ester = 17 ethylene glycol/l/ Glycol esters such as shihenzoate; Fatty acid esters such as methyl acetyl linoleate; Tricresyl phosphate, triphenyl phosphate, etc.) phosphorus esters; epoxy/
Epoxidized oils such as oxidized soybean oil, epoxidized linseed oil;
Tray 1・, citric acid ester glass such as trilobyl/l-1/-; trialquilt φ> +-, tetra-n-octylpyromellitate, polypropylene a/
Pe-1・, 70 songs Ti1]/b of z
Ding"I]!'!lka (zareru. These plastic i11 may be used in one type or in combination of two types and two types.

The amount of scraping can be selected within the range of 20 to 70 parts by weight per 700 parts by weight of vinyl chloride resin.

In order to disperse the vinyl chloride resin powder and plasticizer in water, a dispersant is used.What can be used as a dispersant is one commonly known as a surfactant.

For example, anionic surfactants such as fatty acid soaps, alkyl sulfates, and alkyl sulfonates; cationic surfactants such as primary amine salts, secondary amine salts, and tertiary amine salts; Ampholytic surfactants include nonionic surfactants such as polyoxyethylene alkyl ether and polyoxyethylene alkyl amine.

The above-mentioned dispersant has a ratio of 0/ to 9. - It may be used within the range of % by weight.

In order to disperse the (hinyl chloride-based) yii fat flour rice powder plasticizer in water, these two components are added to the water in which the dispersant has been melted and mixed by stirring. At this time, the ratio of water and solid content (sum of vinyl chloride resin and plasticizer) is determined by adjusting the concentration of solid content in the range of 0 to 0% by weight of the dispersion (sum of water and solid content). do. When the degree of solid content is lower than this range or conversely higher than this range, it is difficult to control the thickness of the final film, and the film does not freeze well. The solid content concentration is particularly preferably in the range of 0 to 60% by weight within the above range.

The dispersion is stirred and mixed in order to absorb the plasticizer into the vinyl chloride resin powder. Vinyl chloride pine resin powder (7,
If the entire amount of the blended plasticizer is absorbed, cracks will occur on the surface of the finally obtained breathable film. Therefore,
Vinyl chloride resin powder ((The plasticizer density to be absorbed is a part of the blended plasticizer, preferably! About half, and the rest is water ((It is good to be in a dispersed state.
- 〆(Well, add excess plasticizer to water and stir.) - a method in which approximately half of the Ushizu plasticizer is absorbed into hinyl chloride-based 4fL1 fat powder, and the remainder is added to water and dispersed.
The amount is good.

The vine stirring mixer used when dispersing the vinyl chloride resin and plasticizer in water may be a 1 μs stirring mixer conventionally used for the purpose of dispersing solids in liquids.

When preparing the dispersion, small amounts of resin stabilizers, ultraviolet absorbers, fillers, dyes, pigments, flame retardants, etc. can be added and mixed.

When preparing the above dispersion using a stirring mixer, the dispersion contains
Since air bubbles, gels, and lumps may be included, it is preferable to remove these using a vacuum deaerator, a Hobart mixer, a roll mill, a filter, or the like.

According to the present invention, the dispersion prepared by the above method is applied to a substrate having surface releasability.

This base material functions to support the coating film based on the dispersion liquid. The base material may be made of a thin metal plate, paper, or a thin heat-resistant resin plate.The surface of this base material on which the coating film will be formed may be a breathable film obtained after heating and melting the coating film, or a film that is easily peeled off. In this way, surface releasability is imparted by applying a mold release agent or the like.

To form a coating film by applying the dispersion to a base material, various coating methods known per se such as spray coating, roll coating, gravure coating, reverse coating, dip coating, and knife coating can be used. It's fine.

The thickness of the coating film formed on the releasable surface of the base material is:
Adjustment 1-Rurikai so that the thickness of the breathable film obtained after the next heating and melting step is in the range of 005 to 05 marks. When the coating film is heated, the moisture evaporates, so that the thickness of the breathable film finally obtained becomes thinner than the original coating film by a proportion corresponding to the moisture contained therein. If the breathable film is too thin, it will not have enough strength and will be less practical, so it is undesirable. It seems that the range of 09mm is f, and ゛ is also 0 in the range.
．． O3-〇, it is better to set it in the range of 30 Firm (・.

According to the present invention, the coating film formed by the above method is heated and melted. By heating, the water contained in the coating film is evaporated, and then the surface of the resin particles is melted, and the adjacent particles are melted. At this time, if the heating temperature is too high, even if the heating time is short, the resin particles will completely melt and the particle shape will collapse, making it impossible to form vent holes. According to experiments, it was found that the optimum temperature for heating and melting varies depending on the secondary transition point of the resin and the amount of plasticizer added to the resin.In other words, the optimum temperature for heating and melting is as follows: Formula (1), Tg+(/so-number of plasticizer added)...(1
) [In (1) 2, Tg is the glass transition point of the vinyl chloride resin, and the number of parts of plasticizer added is the vinyl chloride resin 7
Each refers to the number of parts of plasticizer added per 00 parts by weight. ] It was found that it is best to keep the temperature below the following. Note that if the heating temperature is too low, the surface of the resin particles will not melt even if heated for a long time, and a breathable film with excellent strength will not be obtained. The lower limit temperature during heating and melting is about Sθ°C lower than the temperature expressed by the above formula CI).

For heating and melting operations, it is best to heat for a short time of about 2 to 3 minutes at a temperature slightly lower than the upper limit temperature expressed by equation (1) above, but if heating is performed rapidly at a high temperature, The resulting film often has many small cracks. In order to prevent these small cracks from forming, it is necessary to perform a pre-drying operation by heating within 5 minutes at a temperature of qO to GOC before heating and melting. After volatilizing some of the moisture, heating and melting may be performed.

According to the present invention, first, the breathable film obtained by the above method is cooled to around room temperature, and only the breathable film is
Or is this the base? - Roll it up into rolls.

In addition, if you apply a water repellent material such as +C, silicone oil, silicone emulsion, etc. to one or both sides of the film during or after cooling the breathable film, the film will become Can impart water repellency.

The breathable film obtained by the method of the present invention can be subjected to secondary processing such as printing and adhesion in the same way as ordinary soft plastic films.The breathable film obtained by the method of the present invention can be used independently. .

The method of the present invention has particularly remarkable effects as described below, and has extremely high industrial utility value.

(1) When using the method of the present invention, 0.0/~Q,'
, extremely thin and flexible breathable films in the range of 5-111 m can be easily produced.

(2) When using the method of the present invention, the amount of air permeable in the breathable film, the average particle diameter of the resin powder, the amount of plasticizer, the thickness of the coating film, the blackness of heating and melting the coating film, the time, etc. You can easily change it by selecting it.

(3) When using the method of the present invention, it is easy to color the breathable film finally obtained, and it is also easy to impart water repellency to it.

(4) The breathable film obtained by the method of the present invention is:
A void is formed between adjacent resin particles, and this void communicates from one side of the film to the other side. Therefore, when it is attached to cloth and used for purposes such as rain gear or diaper covers, moisture easily permeates through it and it does not get stuffy.

Hereinafter, the present invention will be explained in more detail based on Examples, but the present invention is not limited to the following columns unless it exceeds the gist thereof.

Example/ Polyvinyl chloride powder produced by 7L polymerization method and dried by spray drying method (average degree of polymerization/100, glass transition point f'1 gO ℃, average particle size 10 microns)
Mix the three components consisting of SO 0 wt % water q 7 wt % and horse chestnut/rubensenosulfonic acid 7-1-(D 13 S ) 3 wt %, and mix? lkA was prepared.

On the other hand, dioctyl phthalate L/-t bj! ;wt%, water 32
Mixture B was prepared by mixing three components consisting of weight percent and DBSJ coulometric ratio.

Shape is ssg weight rope PVVC ioo weight part number of plasticizer added to the trap is! iO parts by weight.

The above dispersion was applied onto the surface of commercially available release paper (paper whose surface is coated with a release agent) by a knife coating method to form a coating film.

The release paper on which the coating film was formed was left in a hot air oven adjusted to gθ°C for 3 minutes to pre-dry the coating film. Subsequently, the release paper with the coated film was left in a hot air oven adjusted to /') OC for 7 minutes to volatilize the moisture almost completely, and then the surface of the polyvinyl chloride powder particles was melted.
Adjacent particle surfaces were attached to each other.

After the above heating and melting operations were completed, the film was cooled to obtain a breathable film with a thickness of Q, /l+1 m. This breathable film is called "film/".

A reactive silicone emulsion (manufactured by Toray Silicone Co., Ltd., S Mg7os) was applied to the surface of "Film/" by the gravure coating method, and after application, it was heated for 30 seconds in a hot air oven adjusted to gθ℃ to remove moisture. It was vaporized. This film is called ``Filmco''.

The air permeability, water repellency, tensile strength, average pore diameter, etc. of "Film/" and "Filmco" were measured by the following methods. The measurement results are shown in Table 1.

Air permeability: Slow gas is sent at a pressure of o, s kg, / cnr, and expressed as the permeation amount per square centimeter for 7 minutes (in 'cc/mrn/).

Water repellent: Conforms to JIS L-1092 spray method.

Tensile strength: Based on JIS K-A732.

Average pore diameter by electron microscopy.

Example/Example/((In the example described, polyvinyl chloride powder was
Produced by emulsion polymerization method and dried by spray drying method, average degree of polymerization / 0Q, glass transition point gθ℃, average particle size 5
A breathable film was produced using the same procedure as described above, except that micron polyvinyl chloride powder was used instead.

A reactive silicone emulsion was applied to the surface of the obtained breathable film in the same manner as in preparing "Film 2" and dried. The breathable film thus obtained is
It's called "Film 3."

Regarding "Film 3", various properties were evaluated in the same manner as in the evaluation of "Film/".

The results are shown in Table 1.

Example 3 Example described in Example/ A dispersion liquid was prepared in the same manner as described on the same side, except that the amount was 3% by weight, the glass transition temperature was 70° C., and the average particle size was 25 μm.

The obtained dispersion was applied as a weight to the surface of a release paper in the same manner as described in Examples, and the coating film was pre-dried. Subsequently, the release paper with the coated film was heated and melted for 1 minute in a hot air oven adjusted to /bO'Qvc.

After cooling, the surface of the obtained breathable film was coated with a reactive silicone emulsion in the same manner as in the preparation of "Filmco" and dried. The breathable film thus obtained is referred to as "film q".

The various properties of "Filmku" were evaluated in the same manner as "Film/" was evaluated.

The results are shown in Table 47.

In the method described in Comparative Example/Example/, the operating conditions of coating, heating, and melting were 1/1: 7 in a hot air oven adjusted to 1 qoCvc.
In addition, a breathable film was manufactured using the same operating procedure as described in ``Returning''.

A reactive silicone emulsion was applied to the surface of the obtained breathable film in the same manner as in preparing "Filmco" and dried. The film thus obtained is called "film s".

Regarding "Filmku", various properties were evaluated in the same manner as "Film/J" was evaluated.

Record the results in the box/table.

Table 1 ( ( From Table 1, the following becomes clear.

(1) The film obtained by the method of the present invention has a large average pore diameter and therefore has excellent air permeability.

(2) When a vinyl chloride resin with a large average particle size is used, the average pore size becomes small, and there is a tendency for the strength to be slightly lowered (“Film 3” and “Film 3”). Comparison with "Filmku").

3) When the soricone emulsion is applied and dried, the water repellency of the breathable film increases dramatically.
Comparison between J and "Films". ).

4) When the coating film is heated and the melting temperature is equal to or higher than the upper limit temperature expressed by the formula f1), the particles are completely melted (because the bath melts and collapses, the average pore size (・) becomes smaller, Air permeability also decreases (relative yield between "Film/" and "Film S".) Applicant Mitsubishi Monsanto Chemicals Co., Ltd. Representative Patent Attorney Hase - (, □・1 or 7 people)

Claims (1)

[Scope of Claims] (1) Polymer milk suspension obtained by emulsion polymerization method or fine suspension polymerization method is dried, and the average particle size is s.
A vinyl chloride resin with a size of 0 microns or less is dispersed in water together with a plasticizer, and this dispersion is applied to a base material with surface releasability to form a coating film.
) formula, that is, Tg + (tso - number of parts of plasticizer added)...(1)
[In formula (I), Tg is the glass transition point of the vinyl chloride resin, and the number of plasticizer added is the vinyl chloride resin io
o Each refers to the number of parts of plasticizer added to parts by weight. ] A method for producing a breathable film, which comprises heating and bath-melting the film at a temperature below the temperature expressed by the formula, followed by cooling. (2) When dispersing vinyl chloride resin in water together with a plasticizer, the temperature should be set near the glass transition temperature of the vinyl chloride resin, and the solid content (vinyl chloride resin and plasticizer) concentration should be 20 to 20% of the dispersion. g. The method for producing a breathable film according to claim 1, wherein the amount is within a range of % by weight. (31 When dispersing a plasticizer in water together with a vinyl chloride resin, approximately half of the total amount of plasticizer is absorbed into the vinyl chloride resin, and the remaining plasticizer is not absorbed into the vinyl chloride resin.) A method for producing a breathable film according to claims (1) to (2), characterized in that a dispersion of ,0.0/
A method for producing a breathable film according to claims (1) to (2), characterized in that the thickness is in the range of 0.0, S mm.