JPH11140760A - Production of hot water-soluble nonwoven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production process for a nonwaven fabric that is made of an oxyalkylene group-containing polyvinyl alcohol and is useful for medical purposes such as operating gowns because it is disposable with no occurrence of environmental troubles due to a reason that it can be dissolved in hot water and can be sterilized after being applied. SOLUTION: An oxyalkylene group-containing polyvinyl alcohol, particularly with an average polymerization degree of 150-5,000 and an average saponification degree of 85-100 mol.%, an oxyalkylene group content of 0.1-20 mol/% that is soluble in hot water heated above 50 deg.C, preferably above 70 deg.C, is melt- extruded through nozzle orifices arranged in plural rows, the extruded filament group is taken up by sucking jet, blown with jetted air flow to the face for forming a nonwoven sheet to form a web, then the web is pressed with a hot embossing roll.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an oxyalkylene group-containing polyvinyl alcohol (hereinafter abbreviated as EO-PVA) nonwoven fabric useful for medical applications such as surgical gowns, which is dissolved in hot water after use. Provided is a method for producing a nonwoven fabric that can be disposable without causing environmental problems because it can be sterilized.

[0002]

2. Description of the Related Art Contaminated cloth products, such as surgical gowns, gauze, and bandages, generated from medical institutions, as well as outside medical institutions,
A recent trend is to dispose as much as possible to prevent infection in medical institutions.

[0003] At present, disposable medical fabrics, especially non-woven fabric products, are mainly made of thermoplastic resin fibers such as polyethylene, polypropylene, polyester and polyamide, or rayon or cotton. However, such products require incineration for treatment after use, and there is a limit to treatment in medical institutions, and external treatment that may cause environmental problems is required. Therefore, such products are soluble in hot water such as PVA fiber. The use of nonwoven fabric products made of fibers is expected.

[0004]

However, the hot-water-soluble PVA-based nonwoven fabric proposed in the prior art has a sufficient water resistance to water at a body temperature or lower temperature such as blood which may come into contact during use. There is a drawback that holes or tears occur during use due to lack of properties, and furthermore, if water-resistant treatment is performed to improve such drawbacks, there is a drawback that the original texture of the nonwoven fabric is lost, and such problems are solved before practical use. There are many issues to be addressed.

[0005]

Means for Solving the Problems In view of such circumstances, the present inventor has made the present invention without impairing the original texture of the nonwoven fabric.
As a result of intensive research to develop a hot water-soluble nonwoven fabric having sufficient water resistance to water at a temperature of about body temperature or less, EO-PVA, particularly the oxyalkylene group content, from a plurality of nozzle holes arranged 0.1-20 mol%, average degree of polymerization 150-5000, average degree of saponification 85-100 mol%, and melts a melt-spinnable EO-PVA resin soluble in hot water at 50 ° C or higher, preferably 70 ° C or higher. This purpose can be achieved when the spun filament group is taken up by a suction jet, sprayed onto the non-woven sheet forming surface by a jet stream to form a web, and then subjected to a bonding process such as pressure bonding with a hot embossing roll. And completed the present invention.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The EO-PVA used in the present invention has an oxyalkylene group represented by Chemical Formula 1 on the side chain of polyvinyl alcohol in an amount of 0.1 to 2.
It contains 0 mol%.

Embedded image [In the formula, R ¹ represents a hydrogen atom or an alkyl group, R ² represents an alkyl group, n represents a positive number, and X represents hydrogen or any of an alkyl group, an alkylamide group, and an alkyl ester group. ]

If the content of oxyalkylene groups in EO-PVA is less than 0.1 mol%, the solubility in water is insufficient, and
If it exceeds 0 mol%, the moldability will decrease. In Chemical Formula ¹ , R ¹ needs to be a hydrogen atom or an alkyl group, and R ² needs to be an alkyl group. R ¹ is preferably a hydrogen atom, and R ² is not particularly limited as long as it is an alkyl group. , Preferably a methyl group.

[0008] The EO-PVA of the present invention can be produced by any method. For example, a method of saponifying after polymerizing a vinyl ester in the presence of a polyoxyalkylene, a method of saponifying after copolymerizing an unsaturated monomer having an oxyalkylene group represented by Chemical Formula 1 with a vinyl ester compound,
A method of post-reacting an alkylene oxide with polyvinyl alcohol may be mentioned, but the above methods are practical in terms of resin production and performance. The following method will be mainly described.

Examples of the unsaturated monomer having an oxyalkylene group include the following. However, the present invention is not limited to only these. [(Meth) acrylic acid ester type] It is represented by the following chemical formula 2, and specifically includes polyoxypropylene (meth) acrylate.

Embedded image (However, Y is a hydrogen or methyl group, A is any of a phenylene group and a substituted phenylene group, l is an integer of 0 or 1 or more,
R ¹ is hydrogen or an alkyl group, R ² is an alkyl group, n is a positive number, preferably an integer of 2 to 60, more preferably 6 to 20. )

[(Meth) acrylic amide type]
And specific examples thereof include polyoxypropylene (meth) acrylamide.

Embedded image (Where Y ¹ represents hydrogen or a methyl group, and A, Y, R ¹ ,
R ² , l and n are the same as above. )

[(Meth) allyl alcohol type]
And specific examples thereof include polyoxypropylene (meth) allyl ether.

Embedded image (However, Y, R ¹ , R ² , and n are the same as described above.)

[Vinyl ether type] It is represented by the following formula 5, and specifically includes polyoxypropylene vinyl ether and the like.

Embedded image (However, A, R ¹ , R ² , l, and n are the same as described above.) Among these oxyalkylene group-containing monomers, (meth) allyl alcohol type monomers represented by the general formula (5) are preferred. It is preferably used.

The above-mentioned vinyl ester compounds include:
Vinyl formate, vinyl acetate, vinyl trifluoroacetate, vinyl propionate, vinyl butyrate, vinyl caprate, vinyl laurate, vinyl versatate, vinyl palmitate, vinyl stearate, vinyl pivalate, etc. are used alone or in combination. However, industrially vinyl acetate is preferred.

In the present invention, a monomer having an oxyalkylene group represented by Chemical Formula 1 as described above and a general monomer other than the vinyl ester compound are used in an amount of 10 mol% or less, preferably 2 mol% or less. The polymerization may be carried out in the coexistence. These monomers are exemplified below. [Unsaturated aliphatic carboxylic acid ethylenically unsaturated dicarboxylic acid (maleic acid, fumaric acid, itaconic acid, etc.) or ethylenically unsaturated dicarboxylic monoester (monoalkyl maleate, monoalkyl fumarate, monoalkyl itaconate) Esters) or ethylenically unsaturated dicarboxylic acid diesters (eg, dialkyl maleate, dialkyl fumarate, dialkyl itaconate) or ethylenically unsaturated carboxylic anhydrides (eg, maleic anhydride, itaconic anhydride), or
(Meth) include monomers such as acrylic acid and salts thereof,
Among them, ethylenically unsaturated carboxylic acids, or ethylenically unsaturated carboxylic acid monoesters and salts thereof are preferably used.

[Alkyl esters of ethylenically unsaturated carboxylic acids, etc.] Methyl crotonate, ethyl crotonate, methyl sorbate, ethyl sorbate, methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylic acid Propyl, butyl (meth) acrylate, pentyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, hexadecyl (meth) acrylate, octadecyl (meth) acrylate And the like. [Α-olefin] ethylene, propylene, α-hexene, α-octene, α-decene, α-dodecene, α-hexadecene, α-octadecene and the like.

[Alkyl vinyl ether] propyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, dodecyl vinyl ether, tetradecyl vinyl ether, hexadecyl vinyl ether, octadecyl vinyl ether and the like. [Alkyl allyl ether] propyl allyl ether,
Butyl allyl ether, hexyl allyl ether, octyl allyl ether, decyl allyl ether, dodecyl allyl ether, tetradecyl allyl ether, hexadecyl allyl ether, octadecyl allyl ether, and the like.

In addition, nitriles such as acrylonitrile and methacrylonitrile, amides such as acrylamide and methacrylamide, olefinsulfonic acids such as ethylenesulfonic acid, allylsulfonic acid and methallylsulfonic acid or salts thereof, and N-acrylamidomethyltrimethyl Compounds having a cationic group, such as ammonium chloride, allyltrimethylammonium chloride, dimethyldiallylammonium chloride, and saponified copolymers of vinyl ketone, N-vinylpyrrolidone, vinyl chloride, vinylidene chloride, etc., are not necessarily limited to these. It is not something to be done.

The average degree of saponification of EO-PVA is 85 mol%.
As described above, it is necessary to select from a range of preferably 90 to 100 mol% and an average degree of polymerization of 150 to 5000, preferably 500 to 3000. Average saponification degree of 85 mol%
Below the fiber becomes soluble in cold water, which is not suitable for the purpose of the present invention, and when the average degree of polymerization is 150 or less, the strength of the nonwoven fabric decreases, and when it is 5000 or more, the viscosity of the spinning solution increases.

Next, the method of the present invention will be described for each step. 1. Spinning raw material preparation step EO-PVA may be in the form of powder or pellets,
The pellets can be advantageously melt-spun. Although water and a plasticizer are not always necessary, even if the EO-PVA is once pelletized and then impregnated with water or a plasticizer, the powder EO-PVA and the water or the plasticizer are introduced into an extruder. It can be melt extruded into pellets. The plasticizer is not particularly limited, and any known plasticizer for PVA can be used. Specifically, sorbitol, polyhydric alcohols such as mannitol, glycerin, diglycerin, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol,
Examples thereof include glycols such as methylpentanetriol, sorbitan fatty acid esters and ethylene oxide adducts thereof, and these are used alone or in combination. Also,
An optional additive such as a cross-linking agent, a dye, an anti-coloring agent, and a neutralizing agent may be further added in such an amount that the subsequent spinning cannot be ignored.

2. Spinning Step The above pellets are melt-spun through a nozzle. Regarding the nozzles, nozzles having an arbitrary shape such as a circle and a corner are used, and an arrangement such as a crosshair, a radiation, and a star is appropriately employed. The practical diameter of the nozzle is 0.01 to 1.0 mm. The melt extrusion is a fiber having a single yarn fineness of 0.5 to 3.0 denier, and the discharge amount from the nozzle port is desirably 0.05 to 1000 g / min.

3. Non-woven fabric manufacturing process The EO-PVA-based spun fiber obtained above is passed through a jet device provided below the nozzle port, where a high-speed jet stream acts to utilize the propulsive force to index the spun fiber downward. Then, the non-woven fabric is formed by uniformly spraying the jet together with the jet flow jetted from the suction jet device on a flat surface or a curved non-fiber sheet forming surface as a collecting device. In addition, a belt conveyor,
Examples include a net and a mold, and an internal suction device may be additionally provided. By such means, the problem of imparting water resistance to water at about body temperature while maintaining the texture can be solved.

As the suction jet device, any known device can be used. In addition, as a gas serving as a medium of the jet stream, air, nitrogen gas, carbon dioxide gas, or the like can be used, but not limited thereto. The device that uses this jet airflow may be operated at an appropriate time from the state where the fibers are not solidified immediately after spinning to the state where the fibers are cooled and solidified, and supplies air at room temperature or dry air to the suction jet device. Then, heat treatment and steam treatment may be performed subsequent to or simultaneously with index stretching by a jet stream. The fibers thus taken up by the jet stream are uniformly sprayed on the flat or curved nonwoven sheet forming surface by the jet stream, and the continuous filament is deposited in a random loop to form a web. To improve the random state,
A collision plate, a charging device, or the like can also be used.

This web is subjected to a bonding treatment. Examples of such treatment include a water needle method, a needle punch method, a chemical bond method, and a hot embossing roll method. The hot embossing roll method is practical. When the hot embossing roll method is carried out, the above web should be 100 to 24
A nonwoven fabric is obtained by passing between hot embossing rolls at about 0 ° C. and partially heat bonding. The filament group to be picked up by the high-speed airflow may be PVA alone or may be aligned with the filament group of other fibers. Further, two or more kinds of the filament groups may be picked up by separate suction jets, and the flat or curved non-uniform filament may be drawn by the jet airflow. It may be sprayed and deposited uniformly on the woven sheet forming surface.

4. Water repellent treatment step The nonwoven fabric obtained above is usually subjected to a water repellent treatment. The water resistance is improved by such treatment. The water repellent treatment is carried out by immersing the nonwoven fabric in a liquid of a water repellent, spraying or coating the liquid repellent on the surface of the nonwoven fabric. For the purpose of the present invention, it is preferable that the adhesion amount of the water repellent is 0.001 to 1% as a solid content per weight of the nonwoven fabric.

Examples of the water repellent include fluorine-based water- and oil-repellents such as perfluorooctyl acrylate polymer, polytetrafluoroethylene, and fluorine resin emulsion; ethylene urea-based such as octadecyl ethylene urea;
Examples thereof include melamines such as methylol melamine, methylolamides such as methylol stearamide, and silicones such as methyl-substituted linear dimethylpolysiloxane. SCOTCHG when listing specific product names
ARD FC-251 (Sumitomo 3M), Octex EM (Hodogaya Chemical), Paraguard 823 425
519Z (Ohara Palladium Chemical), TF-2000
TF-2001 (Matsumoto Yushi), SUMFULOIL
EM-201 (Sumitomo Chemical), Die Roof DC DG70
0 (Daiwa Chemical), NK Guard NDN-7 22 73
00 (Nichika Chemical), PHOENIX PE-1240
There is CW-40P (Futaba Fine Chemical). Thus, the nonwoven fabric obtained in the present invention has a basis weight of 20 to 300 g /
m ² is particularly useful.

In the present invention, the raw material PVA-based fibers include wood fibers such as groundwood pulp, kraft pulp, semi-chemical pulp, sulfite pulp, soda pulp, chemiground pulp and the like, as long as the scope of the present invention is not impaired. ,
Manila hemp, plant fibers such as jute, polyester-based, polyacryl-based, polyolefin-based, polyvinyl chloride-based, hydrophobic synthetic fibers such as polyamide-based, PVA-based fibers other than those defined in the present invention, hydrophilic fibers such as starch, Regenerated fibers such as viscose rayon, viscose soup, and acetate, inorganic fibers such as glass fiber, asbestos, and carbon fiber, and mixtures thereof may be used.

If necessary, various additives such as antibacterial agents, bactericides, antioxidants, dyes, pigments, compositions with plasticizers, crosslinking agents, softening agents, curing agents, anti-stick agents, etc. Well-known reagents can be used in combination.

The nonwoven fabric of the present invention thus obtained is used for various uses including medical use. If you list specific uses, medical gloves, surgical gowns, ouffs, drapes, sheets, pillowcases, sleepwear, curtains, towels, hangings, gowns, headcovers, face masks, shoe covers,
Examples include sponges, bandages, tapes, under bats, diapers, napkins, agricultural sowing sheets, cold gauze, alternatives to film for vinyl houses, paper pots, disposable tableware, trays, tobacco filters, civil engineering bags, and planting bags. When used in such applications, the practicality can be improved by not only using the nonwoven fabric obtained by the present invention alone but also laminating it with a nonwoven fabric produced by another method, for example, a nonwoven fabric obtained by a melt blow method.

[0029]

The present invention will be specifically described below with reference to examples. Example 1 EO-PVA having an average polymerization degree of 1800, an average saponification degree of 99.3 mol%, and an oxyethylene group (n = 8) content of 1 mol%
Pellets are screw diameter 50mm, screw length 800
mm, extruded into a dry nitrogen atmosphere, melted, and spun at a spinning head temperature of 190 ° C., a hole diameter of 0.5 mm, and 670 g / min from a 1000-hole nozzle.
Extrusion is performed at a discharge rate of 40 cm, and then 40 cm below the spinneret.
The jet air flow is applied to the PVA discharge filament by the suction jet device installed at the position of, and the spinning speed is 4000 m /
min, and the suction jet device was traversed at the above-mentioned position, and sprayed and deposited on the wire-mesh-shaped nonwoven sheet forming surface by the jet airflow to produce a uniform web. The single fiber fineness of the fiber taken out from the web was 1.3 denier and the strength was 7 g / d. Then 14
This web was pressed with an embossing roll at 0 ° C. to form a nonwoven fabric.

Table 1 shows the properties of the nonwoven fabric. In addition, each physical property value was measured as follows.

(1) Solubility in hot water A test piece of 30 × 30 mm was put into 300 g of hot water,
The temperature was raised while stirring at 400 rpm, and the temperature at which the dissolution rate became 95% or more was measured. (2) Water resistance According to the static pressure method of the water resistance test A method (low water pressure) of JIS L 1092 (3) Bending resistance JIS L 1085 (41.5 degree cantilever method 20)
cm x 20 cm x 3) (average value in MD and TD directions)

Example 2 The nonwoven fabric of Example 1 was immersed in a fluorine-based resin emulsion (Paraguard 823 manufactured by Ohara Palladium Chemical Co., Ltd.), subjected to a water-repellent treatment, dehydrated and dried to produce a nonwoven fabric having a resin deposition amount of 0.01% by weight. did. Table 1 shows the results.

Example 3 EO-P having an average degree of polymerization of 1200, an average degree of saponification of 89 mol% and an oxyethylene group (n = 10) content of 3.0 mol%
The same experiment as in Example 2 was performed except that VA was used.
Table 1 shows the results.

[0034]

Table 1 Example 1 Example 2 Example 3 Weight per unit area (g / m ² ) 70 70 70 Hot water solubility (° C) 60 65 55 Water pressure resistance (mm / Aq) 170 200 180 Rigidity (mm) 30 35 30

[0035]

According to the present invention, by using a polyvinyl alcohol containing an oxyalkylene group, particularly by a production method by a spun bond method, the body temperature of blood or the like which may come into contact at the time of use or a temperature lower than the temperature is maintained while maintaining the texture. A hot water soluble PVA-based nonwoven fabric having sufficient water resistance can be produced even with water.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshiaki Hirai 2-3-1 Muroyama, Ibaraki-shi Nippon Synthetic Chemical Industry Co., Ltd. Central Research Laboratory

Claims (10)

[Claims] 1. A filament group obtained by melt-spinning an oxyalkylene group-containing polyvinyl alcohol-based resin from a plurality of arranged nozzle holes is drawn by a suction jet, and sprayed onto a non-woven sheet forming surface by a jet stream to form a web. A method for producing a hot-water-soluble nonwoven fabric, which is performed after bonding. 2. The method for producing a hot water-soluble nonwoven fabric according to claim 1, wherein a resin soluble in water at 50 ° C. or higher is used as the oxyalkylene group-containing polyvinyl alcohol resin. 3. The method for producing a hot water-soluble nonwoven fabric according to claim 1, wherein a resin soluble in water at 70 ° C. or higher is used as the oxyalkylene group-containing polyvinyl alcohol resin. 4. A melt-spinnable polyvinyl alcohol resin having an average degree of polymerization of 150 to 5,000 and an average degree of saponification of 85 to 100 mol% is used as the oxyalkylene group-containing polyvinyl alcohol resin. 4. The method for producing a hot-water-soluble nonwoven fabric according to any one of items 1 to 3. 5. An oxyalkylene group-containing polyvinyl alcohol resin having an oxyalkylene group content of 0.1 to 20.
The method for producing a hot water-soluble nonwoven fabric according to any one of claims 1 to 4, wherein the content is mol%. 6. The method for producing a hot-water-soluble nonwoven fabric according to claim 1, wherein the bonding is performed by hot pressing with a hot embossing roll. 7. The method for producing a hot-water-soluble nonwoven fabric according to claim 1, wherein the nonwoven fabric is further subjected to a water-repellent treatment. 8. The method for producing a hot water-soluble nonwoven fabric according to claim 1, wherein the nonwoven fabric is used as a medical or nursing substrate. 9. A nonwoven fabric which can be disinfected and dissolved in water at 70 ° C. or higher after use or with water at 70 ° C. or higher containing a disinfectant as a medical or nursing substrate. 9. The method for producing a hot water-soluble nonwoven fabric according to 8. 10. A nonwoven fabric which can be disinfected and dissolved in hot water of 100 ° C. or higher or hot water of 100 ° C. or higher containing a disinfectant after use as a medical or nursing base material. A method for producing the hot water-soluble nonwoven fabric according to claim 8.