JPH01192814A - Production of polyvinyl alcohol based fiber - Google Patents

Abstract

PURPOSE:To obtain the title fiber having water resistance in one process without lowering spinning efficiency, by using a raw material prepared by introducing acetoacetic estergroups into a PVA based resin and simultaneously adding a crosslinking agent into a spinning bath. CONSTITUTION:An aqueous solution of an acetoacetic ester group-containing PVA based resin (hereinafter referred to as AA group-containing PVA based resin) is spun into a spinning bath containing a crosslinking agent (e.g., formaldehyde or phenol) to provide the aimed fiber. Further, e.g., a resin obtained by an addition reaction of PVA having 80-100mol% average saponification degree and 500-2000 average polymerization degree with diketene is preferably used as the AA group-containing PVA based resin. Furthermore, the content of the crosslinking agent in the spinning solution is preferably 5-50g/l. In addition, the spinning is preferably carried out by normally discharging the spinning solution at 80-90 deg.C through a nozzle into the spinning bath at 10-40 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing polyvinyl alcohol (hereinafter abbreviated as PVA) fibers imparted with water resistance.

[Prior Art] Conventionally, PVA fibers have been used for fibril fibers, paper-making binders, spinning aids, surgical threads, lace base fabrics, variable weaving, decorative threads, etc. Water resistance has been achieved by some method, such as chemical treatment or treatment with a water resistance agent (crosslinking agent), and it has been put into practical use.

[Problems to be Solved by the Invention] However, when carrying out a method of making water resistant by acetalization treatment, for example, PVA is first made into fibers and then subjected to acetalization treatment. The method requires two steps and requires eight steps, and is not industrially advantageous.

Therefore, the present inventors have proposed a method in which a waterproofing agent is mixed into a PVA aqueous solution and then spun, or a method in which a PVA aqueous solution is spun into a coagulating liquid containing a waterproofing agent, in which these two steps are combined into one.
Since the process can be shortened, various studies were conducted regarding this method. However, it has become clear that the former method cannot be used industrially because the spinning solution becomes unstable due to thickening and gelation depending on the type of crosslinking agent, and cannot be sufficiently water-resistant.

On the other hand, in the latter method, the temperature of the spinning bath is at most 40 to 6
Although it was found that the cross-linking reaction hardly occurred under such temperature conditions and a satisfactory water resistance effect could not be obtained due to the restriction of approximately 0°C, we are confident that this problem can be solved by some kind of ingenuity. He continued his research under.

"Means for Solving the Problems" However, the present inventors have discovered that the above object can be achieved by introducing an acetoacetate group (hereinafter abbreviated as AA group) into PVA, and have completed the present invention. .

That is, the present invention provides a method for producing PVA-based fibers, which comprises spinning an acetoacetate group-containing polyvinyl alcohol (hereinafter abbreviated as AA-PVA) resin aqueous solution in a spinning bath containing a crosslinking agent. It is something to do.

The features of the present invention are that AA groups are introduced into the PVA resin, and that a crosslinking agent is contained together with a coagulant during spinning. As a result of the reaction of the AA groups present in PVA with the crosslinking agent proceeding smoothly even at relatively low temperatures, the conventional spinning bath temperature of 40 to 60°C during PVA fiber production can be used as is. Depending on the case, it is possible to operate at a temperature of 10 to 40°C, so there is no concern that the spinning efficiency will be impaired in any way, and it is possible to impart water resistance at the same time as spinning.

The AA-modified PVA used in the present invention is typically produced by reacting PVA with metaketene or the like to produce P V A i,: A A
It is obtained by introducing a group.

The PVA includes not only partially saponified or completely saponified polyvinyl acetate, but also vinyl esters and monomers copolymerizable therewith, such as ethylene, propylene, isobutylene, α-octyne, α-dodecene, α- Olefins such as octadecene, unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid or their salts or mono- or dialkyl esters, nitriles such as acrylonitrile and methacrylonitrile, acrylamide , amides such as methacrylamide, ethylene sulfonic acid, allyl sulfonic acid,
Olefin sulfonic acids or salts thereof such as metaallylsulfonic acid, alkyl vinyl ethers, compounds having cationic groups such as N-acrylamidomethyl trimedelammonium chloride, allyltrimethylammonium chloride, dimethyldiallylammonium chloride, vinyl ketones, N-vinylpyrrolidone, vinyl chloride,
Examples include saponified copolymers with vinylidene chloride and the like, but are not necessarily limited thereto.

The average degree of saponification of PVA is 60 to 100 mol%, preferably 80 to 100 mol%, and the average degree of polymerization is 300 to 4.00.
0. It is advantageous to choose preferably from the range 500 to 2,000.

Any method can be used to incorporate the above P V A +,: A A group, but preferably the PVA
Examples include a method of subjecting ketene to (=J addition reaction) or transesterifying it with acetoacetic acid ester. Maximum possible, but usually 0
It is often selected from the range of 1 to 20 mol%, particularly 0.2 to 10 mol%. If the content of the AA group is too small, it is difficult to obtain the effects of the present invention, and conversely, even if the content is too large, the expected effect cannot be obtained considering the amount used.

Examples of the crosslinking agent to be included in the spinning bath include the following.

(i) Aldehydes monoaldehydes such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde,
Noaldehydes such as glyoxal, malondialdehyde, succinic aldehyde, glutardialdehyde, maleidialdehyde, phthalaldehyde, etc.

(11) Initial reaction product of one or more amino compounds such as amino resin melamine, acetoguanamine, benzoguanamine, urea, etc. and formaldehyde or other aldehyde, or the product of the initial reaction with alcohol, epoxy compound, or other compound. Modified products, such as partially or completely etherified products of methylolmelamine such as methylated methylolmelamine and butylated methylolmelamine.

(iii) Phenolic resin phenol, cresol, ethylphenol, isopropylphenol, L-butylphenol, n-amylphenol, t-amylphenol, t-octylphenol, phenylphenol, xylenol, resorunone, catechol, pyrogallol, thymol, carvacrol, etc. Initial reaction products of one or more phenolic compounds and other aldehydes such as formaldehyde or furfural, or products modified with alcohols, epoxy compounds, or other compounds.

(1v) Epoxy compounds ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, chryselin di- or triglynonol ether, 1,6-hexanediol noglycidyl ether, trimedylolpropane tricrinone ether, schifringyl aniline, di- Glycidylamine etc.

(v) Isonanate compounds such as tolylene diisonanate, hydrogenated tolylene diisonoanate, trimethylolpropane-tolylene diisonanate atact, triphenylmethane triisonanate, medilenepis (4-phenylmethane triisonanate, Isophorone diisocyanate, and these compounds, oquine-blocked products, phenol-blocked products, etc.

(vl) Ammonium salts Ammonium salts of mineral acids such as ammonium chloride, ammonium sulfate and ammonium nitrate; ammonium salts of organic acids such as ammonium acetate and ammonium propionate;

(vii) Compounds with radical generating ability hydrogen peroxide, potassium persulfate, ammonium persulfate, benzoyl peroxide, succinic peroxide, t-butyl peroxide maleic acid,
L-butylhydroperoxytobenzoin alkyl ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, organic sulfur compounds such as dibutyl sulfide, benzyl sulfide, decylphenyl sulfide, diazonium salts, tetrazonium salts, or chlorides thereof Complex salts with zinc or condensates thereof, dyes such as azobisisobutyronitrile, 2,2′-azobis(2-amidinopropane) hydrochloride, methylene blue, or combinations thereof with p-toluenesulfonate ions, etc. Pyrylium salt or devirylium salt, ammonium dichromate, acetophenone, benzophenone, benzyl, phenanthrene, dioxanthone, dichloropropylphenyl ketone, anthraquinone, 2-chloroanthraquinone, 2-bromoanthraquinone, anthraquinone β-sodium sulfonate, 1.5-
Dinitroanthraquinone, 1,2-penzanthraquinone, phenanthrenequinone, 5-benzoylacenaphthene, 5-nitroacenaphthene, 1,4-naphthoquinone, ■
, 8-phthaloylnaphthalene, 2-nitro7=7-luorene, p-nitroaniline, picramide, etc.

(viii) Oxidizing agents potassium dichromate, ammonium dichromate, calcium perchlorate, etc.

(1x) Metal salts Chlorides, bromides, nitrates, sulfates, acetates, etc. of polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, zirconium, titanium, etc. Examples of salts include cupric chloride, aluminum chloride, ferric chloride, tin chloride, zinc chloride, nickel chloride, magnesium chloride, aluminum sulfate, copper acetate, chromium acetate, etc.

(X) Other common crosslinking agents used in AA-PVA resins, such as polyfunctional compounds such as polyhydric alcohols and polybasic acids, and bentonite.

The content of the crosslinking agent exemplified above in the spinning bath is 2 to 20
A value of 0@/ρ, preferably 5 to 50/ρ is appropriate.

Next, each step of the spinning method of the present invention will be explained in more detail.

18 = 1 Stock solution preparation step AA PVA resin at a predetermined concentration (usually 14 to 16% by weight)
) in a melting machine for 0 to 15 hours, 60 to 9
Dissolution is performed by heating at 0°C. For example, if mattness or color fastness is required, optional auxiliary agents such as titanium oxide or pigments of the desired hue may be added at the later stage of dissolution, and mixed uniformly.

2. Spinning process The stock solution at 80-90°C is extruded through a spinneret into a spinning bath at 10-40°C to form fibers.

As a coagulant, salts such as mirabilite, ammonium sulfate, and sodium phosphate, and alkalis such as sodium hydroxide can be used, but an aqueous solution of mirabilite is mainly used industrially due to its coagulating ability and economical efficiency.

Examples of practical spinning solutions using such a coagulant include a saturated aqueous solution of Glauber's salt or a saturated aqueous solution of ammonium sulfate.
9/a1 is preferably contained in an amount of 5 to 50 g.

Further, in order to prevent coloration in this step, zinc sulfate, magnesium sulfate, or a small amount of sulfuric acid may be added to the spinning bath, or a trace amount of salts of heavy metals such as copper or manganese may be added.

Furthermore, as the spinning solution, not only water-based solvents but also organic solvents such as alcohol-based solvents such as methanol can be used.

Regarding the spinneret, any nozzle shape such as circular or square can be used, and cross-hair, radial, star-shaped, etc. arrangements may be employed.

The PVA fibers coagulated and crosslinked in this spinning process are pulled out from the coagulation bath by rollers, and are transferred to drying, stretching, etc. processes as required.

The uses of the fiber obtained by the production method of the present invention include:
It is expected to be used in a variety of other fields, including fiber binders, paper strength enhancers, general medical products such as gauze and bandages, daily life products such as dish towels, and immobilization of enzymes and bacterial cells.

[Function] The method for producing PVA-based fibers of the present application, which is characterized by spinning an aqueous solution of AA-modified PVA-based resin in a spinning bath containing a crosslinking agent, provides water-resistant PVA-based fibers in one step. Has advantages.

[Example] Hereinafter, the present invention will be explained in more detail by giving examples.

Example 1 AA-modified PV with a degree of AA of 10 mol% obtained by reacting diketene with PVA with a degree of polymerization of 1500 and a degree of saponification of 99 mol%
15% by weight aqueous solution of A, sodium sulfate (Na2SO4) 4009/ρ(
Water) Zinc sulfate (znso,) 20g #
! (Water) Glyoxal (crosslinking agent) ]Oy
/Q (water) into a spinning bath of composition, circular, 0,1 mm.
φ, a spinneret with 100 holes in a radiation arrangement, and a discharge rate of 12
g/min, spinning at a speed of 50 m/min,
Furthermore, the obtained fibers were air-dried (moisture content: 8% by weight). As a result, fibers of 1.5 denier were obtained. The spinning bath temperature at this time was 45°C.

The obtained fibers were left in boiling water for 1 hour, but no dissolution was observed.

Examples 2 to 9 Experiments were conducted according to the method of Example 1 for various cases shown in Table 1 regarding the degree of PVAOAA, coagulant, crosslinking agent, and spinning bath temperature. The results are also shown in Table 1.

Control Example An experiment was conducted according to the method of Example 1 using PvA with a degree of polymerization of 1500 and a degree of saponification of 99 mol%. Results first
Shown in the table.

"Effect" As described above, pvA is characterized by spinning the aqueous solution of the AA-PVA resin of the present invention in a spinning bath containing a crosslinking agent.
The method for producing PVA-based fibers is extremely useful industrially because water-resistant PVA-based fibers can be obtained in one step.

Patent applicant Nippon Gosei Kagaku Kogyo Co., Ltd. Procedural amendment 1, Indication of the case Patent application No. 14188 of 1988 2, Name of the invention Process for manufacturing polyvinyl alcohol fiber 3, Person making the amendment Relationship to the case Patent applicant Address: 9-6 Nozaki-cho, Kita-ku, Osaka (zip code 530)
4. Column 5, Detailed Description of the Invention in the Specification Subject to Amendment, Contents of the Amendment (1) "During spinning" in line 1θ of page 3 of the specification is corrected to "in a spinning bath."

(2) Insert ``, primary amine, secondary amine, tertiary amine, or diamine'' after ``1 bentonite'' on page 9, line 15 of the specification.

(3) "Ammonium sulfate aqueous solution" in Table 1, page 13 of the specification is corrected to "Ammonium sulfate (NH4) 2S 04J."

Claims (1)

[Claims] A method for producing polyvinyl alcohol fibers, which comprises spinning an acetoacetate group-containing polyvinyl alcohol resin aqueous solution in a spinning bath containing a crosslinking agent.