JPH11140759A - Production of hot water-soluble nonwoven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production process for a nonwoven fabric that is made of a polyvinyl alcohol (hereinafter abbreviated to PVA) 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: A composition of a plasticizer and a hot water-soluble PVA resin, particularly with an average polymerization degree of 150-5,000 and an average saponification degree of 85-100 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 jetting 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 a polyvinyl alcohol (hereinafter abbreviated as PVA) -based nonwoven fabric useful for medical applications such as surgical gowns, which can be dissolved and sterilized in hot water after use. To provide a method for producing disposable non-woven fabric without causing environmental problems.

[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 lower, a composition of a PVA-based resin and a plasticizer is formed through a plurality of nozzle holes. Particularly, a filament group obtained by melt-spinning a melt-spinnable PVA resin having an average degree of polymerization of 150 to 5000, an average degree of saponification of 85 to 100 mol%, and soluble in hot water of 50 ° C. or higher, preferably 70 ° C. or higher is formed into a suction jet. The present inventors have found that such a purpose can be achieved in the case of performing a bonding treatment such as forming a web after forming the web by spraying onto a non-woven sheet forming surface with a jet airflow, and accomplishing the present invention.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The PVA resin used in the present invention includes not only partially saponified or completely saponified polyvinyl acetate but also a vinyl ester and a monomer copolymerizable therewith, such as ethylene, propylene, isobutylene, α-octene, α Olefins such as dodecene and α-octadecene; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, and itaconic acid or salts thereof, and mono- or dialkyl esters; acrylonitrile, methacrylonitrile, etc. Nitriles, amides such as acrylamide and methacrylamide, olefinsulfonic acids such as ethylenesulfonic acid, allylsulfonic acid and methallylsulfonic acid or salts thereof, alkyl vinyl ethers, N-acrylamidomethyltrimethylammonium chloride, allyl Limethylammonium chloride, a compound having a cationic group such as dimethyldiallylammonium chloride, vinyl ketone, N-vinylpyrrolidone, vinyl chloride, vinylidene chloride, saponified copolymers with oxyalkylene group-containing compounds, but not necessarily. It is not limited to these.

The average saponification degree of the PVA resin 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. Such PVA resin is hot water, that is, 50 ° C. or more, preferably 70 ° C.
Since it is necessary to dissolve in water at a temperature of not less than ° C, the PVA fiber is subjected to heat treatment, drawing, and other processes such as water insolubilization. Such a PVA-based resin can be more efficiently melt-spun by including a plasticizer. The content of the plasticizer is practically 0.1 to 20% by weight, preferably 3 to 10% by weight, based on the composition. The plasticizer is not particularly limited, and any known plasticizer for PVA can be used. Specifically, polyhydric alcohols such as sorbit and mannitol, glycerin, diglycerin, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, glycols such as methylpentanetriol, sorbitan fatty acid esters and ethylene oxide adducts thereof, and the like. Illustrated, these may be used alone or in combination.

Next, the method of the present invention will be described for each step. 1. Spinning raw material preparation process The PVA resin may be in the form of powder or pellets,
The pellets can be advantageously melt-spun. To incorporate the plasticizer, the PVA-based resin may be once pelletized and then impregnated with the plasticizer, or the powdered PVA-based resin and the plasticizer may be introduced into an extruder and melt-extruded into pellets. Further, an optional additive such as a crosslinking 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.

[0009] 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 30 to 2000 g / min.

[0010] 3. Non-woven fabric manufacturing process The PVA-based spun fiber obtained above is passed through a jet device provided below the nozzle port, where a high-speed jet stream is applied to index the spun fiber downward by using its propulsive force, The non-woven fabric is formed by uniformly spraying and depositing a jet together with the jet stream ejected from the suction jet device on a flat or curved non-fiber sheet forming surface as a collecting device.
In addition, a belt conveyor, a net,
A mold or the like may be used, 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 air flow may be operated at an appropriate time from the state of the unsolidified fiber immediately after spinning until it is 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.

The web is subjected to a bonding treatment. Examples of such a 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 fluororesin emulsion; ethylene urea such as octadecylethylene 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, wood fibers such as groundwood pulp, kraft pulp, semi-chemical pulp, sulfite pulp, soda pulp, chemi ground pulp, and the like are used as raw PVA-based fibers without impairing the scope of the present invention. ,
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 applications, 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.

[0018]

The present invention will be specifically described below with reference to examples. Example 1 PV having an average degree of polymerization of 1800 and an average degree of saponification of 99.3 mol%
A pellet (containing 15% by weight of diglycerin as a plasticizer) with a screw diameter of 50 mm and a screw length of 800 mm
Of the extruder, the supply port was dried under a nitrogen atmosphere, and then melted. The spinning head temperature was 180 ° C., and the hole diameter was 0.5.
Extrusion was carried out at a discharge rate of 670 g / min from a nozzle having a diameter of 1000 mm and a hole of 670 g / min. Then, a jet stream was applied to the PVA discharge filament by a suction jet device installed at a position 40 cm below the spinneret, and a spinning speed of 4000 m / min.
Then, the suction jet device was sprayed and deposited on the wire-mesh-shaped nonwoven sheet forming surface by the jet airflow while the suction jet device was traversed at the above position to produce a uniform web. The single fiber fineness of the fiber taken out of this web is 1.
One denier and strength was 12 g / d. Then 140
The web was pressure-bonded with an embossing roll at a temperature of ° 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 fluororesin 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 PVA having an average degree of polymerization of 1200 and an average degree of saponification of 89 mol%
The same experiment as in Example 2 was performed except that was used. Table 1 shows the results.

[0023]

Table 1 Example 1 Example 2 Example 3 Weight per unit area (g / m ² ) 60 60 60 Solubility in hot water (° C) 90 90 60 Water pressure resistance (mm / Aq) 185 270 180 Rigidity (mm) 35 40 35

[0024]

According to the present invention, the body temperature of blood or the like that may come into contact with the material at the time of use is maintained by using a composition of a specific PVA resin and a plasticizer, particularly by a production method by a spun bond method while maintaining a feeling. Alternatively, hot water-soluble PV having sufficient water resistance to water at a temperature lower than that
A type nonwoven fabric can be manufactured.

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

Claims (10)

[Claims] 1. A filament group obtained by melt-spinning a composition of a polyvinyl alcohol-based resin and a plasticizer 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. A method for producing a hot-water-soluble nonwoven fabric, comprising forming a web and performing a bonding treatment. 2. A polyvinyl alcohol resin of 50
2. The method for producing a hot-water-soluble nonwoven fabric according to claim 1, wherein a resin soluble in water at a temperature of not less than ° C is used. 3. A polyvinyl alcohol-based resin of 70
2. The method for producing a hot-water-soluble nonwoven fabric according to claim 1, wherein a resin soluble in water at a temperature of not less than ° C is used. 4. A polyvinyl alcohol-based resin having an average degree of polymerization of 150 to 5000 and an average degree of saponification of 85 to 100 mol%, which can be melt-spun, is used as the polyvinyl alcohol-based resin. A method for producing the hot water-soluble nonwoven fabric described in the above. 5. The content of the plasticizer is 0.1 to 0.1 per composition.
The method for producing a hot-water-soluble nonwoven fabric according to any one of claims 1 to 4, wherein the content is 20% by weight. 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 hot water of 70 ° C. or higher or hot water of 70 ° C. or higher containing a disinfectant after use as a medical or nursing substrate. A method for producing the hot water-soluble nonwoven fabric according to claim 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.