JP2009013558A - Fiber and nonwoven fabric - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyvinyl alcohol-based fiber causing neither resin lump around a spinneret nor thread breakage in melt-spinning, excellent in texture and having no smell. <P>SOLUTION: The fiber includes (A) a polyvinyl alcohol resin having 1,2-diol structural units represented by general formula (1), and (B) an alkylene oxide adduct of a polyhydric alcohol. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fiber and a nonwoven fabric containing a polyvinyl alcohol resin composition (hereinafter referred to as “PVA fiber”), and more specifically, a fiber containing a PVA resin composition excellent in melt spinnability. And a non-woven fabric using the same.

  Fibers made of water-soluble resins and products using woven or non-woven fabrics using the same are used in various applications. Among these, fiber products made from PVA resin, which is a water-soluble resin, are useful because of their high tensile strength, and are used in various fields.

As a method for fiberizing the PVA-based resin, a so-called wet spinning method in which an aqueous solution of the PVA-based resin is extruded from a nozzle into an aqueous solution such as sodium sulfate and solidified is common. However, the wet spinning method can be applied only to a highly saponified PVA resin having excellent coagulation properties, and such a highly saponified PVA resin has high crystallinity and is soluble only in high-temperature water. Thus, it was impossible to obtain a PVA resin fiber excellent in water solubility.
Further, in the case of the melt spinning method which is a general method for spinning thermoplastic resins, the PVA resin has a close melting start temperature and a thermal decomposition temperature, and stable melt spinning is difficult.

In response to this problem, a PVA resin fiber using a resin composition excellent in melt spinnability, in which an alkylene oxide adduct of a polyhydric alcohol is contained as a plasticizer in a low polymerization degree PVA resin, has been proposed. (For example, refer to Patent Document 1). In this case, it is described that the melt viscosity is further lowered and the spinnability is improved by using a PVA resin modified with α-olefin or the like rather than unmodified PVA.
However, even if the resin composition described in Patent Document 1 is used, a melt spinning temperature of 200 ° C. or higher is actually required, and by spinning at such a high temperature, a low molecular compound such as a plasticizer is decomposed. -There was a problem that the resin volatilized and a lump of resin (called a spear) occurred around the spinneret, resulting in a decrease in long run properties and product quality. In addition, in order to obtain finer fibers, when the fibers are pulled strongly after spinning or at high speed, there is a problem that yarn breakage may occur due to insufficient compatibility of the constituent components.
In addition, in order to obtain a fiber having excellent water solubility, it is necessary to use a PVA resin having a low saponification degree. In this case, the acetate group in the PVA resin is thermally decomposed during melt spinning, and the fiber is acetic acid. Odor may remain.
JP 2001-302868 A

  An object of the present invention is to provide a PVA-based resin fiber that is excellent in processability at the time of melt spinning, can be taken up at high speed, has an excellent texture, and has no odor.

  As a result of intensive studies in view of the above circumstances, the present inventor has used a PVA resin (A) having a specific structure, and a resin composition in which an alkylene oxide adduct (B) of a polyhydric alcohol is blended as a plasticizer. It was found that the object of the present invention was achieved by using a product as a fiber raw material, and the present invention was completed.

That is, the gist of the present invention includes a polyvinyl alcohol resin (A) having a 1,2-diol structural unit represented by the following general formula (1) and an alkylene oxide adduct (B) of a polyhydric alcohol. It exists in the fiber characterized by this.

  The effect of the present invention is that, by adopting a PVA resin having a 1,2-diol structural unit represented by the general formula (1) as a PVA resin, addition of an alkylene oxide of a polyhydric alcohol as a plasticizer This is obtained by greatly improving the compatibility with the product (B).

  That is, since the PVA resin composition used for the fiber of the present invention can be melt-spun at a low temperature of 200 ° C. or lower, decomposition and volatilization of the plasticizer and thermal deterioration of the PVA resin itself are suppressed. No gels or spears are generated, and yarn breakage does not occur during long-run spinning, so that stable spinning is facilitated without lowering productivity and product quality. In addition, the PVA resin used in the present invention has a side chain 1,2-diol structure, so even if it has a high degree of saponification, its crystallinity is small, so it is possible to obtain fibers with excellent water solubility. It is.

A feature of the fiber of the present invention is that a PVA resin having a 1,2-diol structure in the side chain of PVA is used as the PVA resin.
In contrast, the 1,3-glycol bond, which is the main bonding mode of the PVA main chain, increases the head-to-head or tail-to-tail bond ratio by raising the polymerization temperature of polyvinyl acetate higher than usual. It is known that the obtained PVA having a main chain 1,2-glycol bond amount higher than a normal value (about 1.8 mol%) is subjected to melt molding (Japanese Patent Application Laid-Open No. 2001-181405). However, such a main chain 1,2-glycol bond is less effective in reducing crystallinity than the side chain 1,2-diol structure of the PVA of the present invention, and all of its hydroxyl groups are secondary as in ordinary PVA. Since it is a hydroxyl group, the strong hydrogen bond resulting from a primary hydroxyl group, the intermolecular cohesive force, and the compatibility improvement effect with a plasticizer like the PVA resin (A) used in the present application cannot be obtained.

  In addition, it is known that PVA having a monohydroxyalkyl group in the side chain obtained by copolymerizing an α-olefin having a hydroxyl group at the terminal is subjected to melt molding (Japanese Patent Laid-Open No. 2001-302868). The exemplified PVA resin in which a hydroxyl group is bonded to the main chain through a relatively long alkylene group may cause abnormal flow during melt spinning and the like, and further improvement is required for the effect of improving spinnability and compatibility. It is what

  The fiber of the present invention is used as a nonwoven fabric in various applications that require good water solubility and hydrophilicity, for example, embroidery substrates for clothes, chemical laces, etc., scratch protection protecting materials for automobiles, filtration filters, and confidential texts. It is useful for paper, detergents, softeners, pesticide bags, medical surgical clothes, etc.

Hereinafter, the present invention will be described in detail.
The description of the constituent requirements described below is an example (representative example) of an embodiment of the present invention, and is not limited to these contents.

The fiber in the present invention means a single fiber and a composite fiber.
The fiber of the present invention mainly comprises a polyvinyl alcohol resin (A) having a 1,2-diol structural unit represented by the following general formula (1), and an alkylene oxide adduct (B) of a polyhydric alcohol. ) In a range that does not impair the spirit of the present invention depending on the required performance, or a resin composition in which other resins and additives are uniformly mixed, It is good also as composite fiber using this resin composition and other resin.

First, the PVA resin (A) used in the present invention will be described.
Content of the said structural unit (1) in the PVA-type resin (A) used by this invention is 1-15 mol% normally, Preferably it is 2-12 mol%, Most preferably, it is 3-8 mol%. . If the content is too small, the melting point becomes high and the difference from the thermal decomposition temperature becomes small, so the melt spinning temperature range becomes narrow and the melt spinnability is lowered. Further, the long run property tends to be remarkably lowered. If the amount is too large, the metal adhesion is remarkably increased, and the generation of gels and the generation of thermally cross-linked / thermally deteriorated products becomes severe, and stable spinning tends to be impossible.
Further, when adjusting the content, it is also possible to adjust by blending at least two PVA resins (A) having different contents of the structural unit (1), and at least one of them is a structure. A PVA-based resin not containing the unit (1) may be used.
However, even in the case where a PVA resin containing the structural unit (1) and a PVA resin not containing this are blended and used, the former needs to be the main component and contains the structural unit (1). The PVA resin content is preferably 60 to 99% by weight, particularly 70 to 99% by weight.

With regard to the PVA-based resin in which the content of the structural unit (1) is adjusted in this way, the amount can be calculated by weight average, and can be calculated accurately from the measurement result of ¹ H-NMR. it can.

The saponification degree of the PVA-based resin (A) is usually 80 to 99.9 mol%, preferably 85 to 99.9 mol%, particularly preferably 88 to 99.9 as measured by a titration method (JIS K6726). 9 mol%. If the degree of saponification is too low, an odor of acetic acid is generated, the thermal stability is lowered, and the stability during long-time melt spinning, that is, the long run property tends to be deteriorated.
The lower the saponification degree of the PVA-based resin, the lower the melting point and the easier the hot melt molding, but if the saponification degree is too low, the acetic acid odor is generated, the thermal stability is lowered, and the long run property is reduced. It tends to get worse. The resin composition of the present invention is characterized in that it exhibits good hot melt moldability even when a PVA resin having a high saponification degree is used.
The degree of saponification in the present invention refers to the rate of change of the total amount of the ester portion of the vinyl ester monomer and the acyloxy portion, carbonate portion, and acetal portion of the comonomer corresponding to the 1,2-diol structural unit to the hydroxyl group ( Mol%).

The degree of polymerization of the PVA resin (A) is usually 200 to 1200, preferably 250 to 750, particularly preferably 300 to 500, as measured by an aqueous solution viscosity measurement method (JIS K6726). If the degree of polymerization is too low, the strength of the fiber becomes low and yarn breakage is likely to occur. If it is too high, the resin tends to thermally decompose due to the generation of shearing heat in the extruder.
Melting | fusing point of PVA-type resin (A) is 90-220 degreeC normally, Furthermore, 120-200 degreeC, Most preferably, it is 150-180 degreeC.

  Although it does not specifically limit about the manufacturing method of PVA-type resin (A) used by this invention, As a comonomer, 3, 4-diol- 1-butene, 3, 4- diacyloxy 1-butene, 3-acyloxy- 4-ol-1-butene, 4-acyloxy-3-ol-1-butene, 3,4-diacyloxy-2-methyl-1-butene, and the like are copolymerized with a vinyl ester monomer. A method of obtaining a polymer and then saponifying it, or [2] using vinyl ethylene carbonate or the like as a comonomer to copolymerize these with a vinyl ester monomer to obtain a copolymer, which is then saponified and depolymerized. Carbonate, or [3] 2,2-dialkyl-4-vinyl-1,3-dioxolane or the like as a comonomer and vinyl ester mono To obtain a copolymer, and then saponified and dehydrated in an aqueous solution (water or a mixed solvent of water / acetone, water / alcohol having 1 to 4 carbon atoms, etc.) using an acid catalyst. The method of ketalization etc. is mentioned.

  Among them, the polymerization proceeds well, and it is easy to uniformly introduce 1,2-diol structural units into PVA, and there are few problems at the time of melt-molding the obtained PVA, In view of the final film characteristics, the production method [1] is preferably used, and particularly preferably, 3,4-diacyloxy-1-butene and a vinyl ester monomer are used in view of excellent copolymerization reactivity. This is a method for saponifying a copolymer obtained by copolymerization. Furthermore, it is preferable to use 3,4-diacetoxy-1-butene as 3,4-diacyloxy-1-butene. Moreover, you may use the mixture of these said monomers.

  Examples of the vinyl ester monomers include vinyl formate, vinyl acetate, vinyl propionate, vinyl valelate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate, versatic. And vinyl acid. Of these, vinyl acetate is preferably used from the economical viewpoint.

In addition, the reactive ratio of each monomer when vinyl acetate is used as the vinyl ester monomer and 3,4-diacetoxy-1-butene is copolymerized is r (vinyl acetate) = 0.710, r ( 3,4-diacetoxy-1-butene) = 0.701, and in the case of vinyl ethylene carbonate described later, r (vinyl acetate) = 0.85, r (vinyl ethylene carbonate) = 5.4, 3,4-diacetoxy-1-butene is superior in copolymerization reactivity with vinyl acetate.
The chain transfer constant of 3,4-diacetoxy-1-butene is Cx (3,4-diacetoxy-1-butene) = 0.003 (65 ° C.). In the case of vinyl ethylene carbonate, Cx (vinyl Ethylene carbonate) = 0.005 (65 [deg.] C.) and Cx (2,2-dimethyl-4-vinyl-1,3-dioxolane) in the case of 2,2-dimethyl-4-vinyl-1,3-dioxolane = Compared with 0.023 (65 ° C.), it is a hindrance to polymerization and does not easily increase the degree of polymerization or cause a decrease in polymerization rate.

  In addition, such 3,4-diacetoxy-1-butene is the same as that derived from the vinyl acetate structural unit, which is a main structural unit, as a by-product generated when the copolymer is saponified. The fact that there is no need to provide a special device or process is also a great industrial advantage. Further, 3,4-diacetoxy-1-butane, 1,4-diacetoxy-1-butene, 1,4-diacetoxy-1-butane and the like may be contained as a small amount of impurities.

  3,4-diol-1-butene is available from Eastman Chemical Co., and 3,4-diacetoxy-1-butene is commercially available from Eastman Chemical Co. be able to. Further, 3,4-diacetoxy-1-butene obtained as a by-product during the production process of 1,4-butanediol can also be used. Moreover, what synthesize | combined 3, 4- diacetoxy-1-butene by the method of international publication number WO00 / 24702 can also be used.

  The water-soluble PVA having a 1,2-diol structural unit produced by the process of [2] above has a carbonate ring remaining in the side chain when the degree of saponification is low or when decarboxylation is insufficient, Decarboxylation during melt molding may cause bubbles in the molded product, which may cause fish eyes and may reduce compatibility with the component (B). . And the water-soluble PVA having a 1,2-diol structural unit produced by [3], the monomer-derived functional group (acetal ring) remaining in the side chain is melt-molded as in the production method [2]. Since it tends to detach from time to cause odors of aldehydes, it must be used with this in mind.

  The amount of the comonomer used for the copolymerization may be determined in accordance with the desired introduction amount of the 1,2-diol structural unit represented by the general formula (1) described above.

In addition to the PVA resin itself having a 1,2-diol structural unit represented by the above general formula (1), the PVA resin (A) in the present invention is a small amount (usually in a range not inhibiting the effects of the present invention). 20% or less, preferably 15% or less, particularly preferably 10% or less), and a PVA resin copolymerized with a copolymerizable unsaturated monomer. However, this means that the effect of the present invention can be obtained.
Examples of the unsaturated monomer include hydroxy groups such as α-olefins such as ethylene and propylene, 3-buten-1-ol, 4-penten-1-ol, and 5-hexene-1,2-diol. Derivatives such as α-olefins and esterified products thereof, unsaturated acids such as itaconic acid, maleic acid and acrylic acid, or salts thereof, mono- or dialkyl esters, nitriles such as acrylonitrile, amides such as methacrylamide and diacetone acrylamide And compounds such as olefin sulfonic acids such as ethylene sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, and AMPS or salts thereof.

  In addition, it is preferable to add a known polymerization inhibitor used in radical polymerization to the reaction system at the end of the polymerization. Examples of the polymerization inhibitor include m-dinitrobenzene, ascorbic acid, benzoquinone, and α-methylstyrene. Body, p-methoxyphenol and the like.

  The copolymer thus obtained is then saponified to obtain a PVA resin (A) having a 1,2-diol structural unit represented by the general formula (1).

  The PVA-based (A) resin used in the present invention may be a blend of a PVA-based resin containing the structural unit (1) and another PVA-based resin different from the PVA-based resin. Examples thereof include those having different structural units, those having different saponification degrees, and those having different molecular weights.

  In the PVA resin composition used for the fiber of the present invention, the PVA resin (A) is a base resin. The content thereof is usually 50 to 98% by weight, preferably 80 to 98% by weight, particularly preferably 90 to 98% by weight, based on the total weight of the resin composition. When the content of the PVA resin (A) is too small, the strength of the fiber is lowered, the melt tension is remarkably reduced, and melt spinning tends to be impossible.

［式中、Ｒ¹は水酸基を１つ以上有する有機基であり、Ｒ²〜Ｒ⁵は水素または有機基を示す。ｎおよびｍは０以上の整数であり、その結合順序はランダム状でもブロック状でもよく、ｎ＋ｍ＞０である。］
また、アルキレンオキシドが多価アルコールの分子内または分子間の水酸基間を架橋した構造をとる場合もある。本発明で用いる多価アルコールのアルキレンオキシド付加物（Ｂ）は、これら多価アルコールとアルキレンオキシドが反応して得られた反応物の混合物である。 In this invention, the alkylene oxide adduct (B) of a polyhydric alcohol is used together with the said (A) component, It is characterized by the above-mentioned.
Hereinafter, the alkylene oxide adduct (B) of such a polyhydric alcohol will be described.
Such an adduct (B) is a compound having an ether bond and a hydroxyl group as a result of addition of alkylene oxide to the hydroxyl group of a polyhydric alcohol.
A schematic diagram of this reaction is shown in the following chemical formula (I). In the formula, R ¹ is an organic group having one or more hydroxyl groups, but the hydroxyl groups are omitted for convenience. However, such a hydroxyl group can react similarly to the illustrated hydroxyl group.

[Wherein, R ¹ represents an organic group having one or more hydroxyl groups, and R ^{2 to} R ⁵ represent hydrogen or an organic group. n and m are integers greater than or equal to 0, and the bonding order may be random or block, and n + m> 0. ]
In some cases, the alkylene oxide may have a structure in which hydroxyl groups are cross-linked within or between polyhydric alcohol molecules. The alkylene oxide adduct (B) of polyhydric alcohol used in the present invention is a mixture of reactants obtained by reacting these polyhydric alcohol and alkylene oxide.

  In the present invention, the hydroxyl value of the alkylene oxide adduct (B) of polyhydric alcohol is important. When the polarity indicated by the adduct (B) is suitable for the polarity of the resin (A), the compatibility of both components is further improved. Then you can guess. The adduct (B) has a hydroxyl value (mgKOH / g) of usually 200 to 1500 mgKOH / g, preferably 260 to 935 mgKOH / g, particularly preferably 315 to 750 mgKOH / g.

  The polyhydric alcohol in the adduct (B) is a compound having a plurality of hydroxyl groups, and is usually a 2 to 15 valent polyhydric alcohol, preferably a 2 to 10 valent polyhydric alcohol, particularly preferably 3 to 3. Hexavalent, particularly preferably trivalent polyhydric alcohols. Moreover, it is a C2-C20 polyhydric alcohol normally, Preferably it is a C3-C10 polyhydric alcohol, Most preferably, it is a C3-C6 polyhydric alcohol.

  Such a polyhydric alcohol compound may be aliphatic or aromatic, but is preferably an aliphatic alcohol. Specifically, glycerin and glycerin derivatives such as diglycerin, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene Examples include polymethylene glycols such as methylene glycol, ethylene glycol, ethylene glycol derivatives such as diethylene glycol and triethylene glycol, propylene glycol derivatives such as propylene glycol and dipropylene glycol, and their generic names include alkylene glycol derivatives. Further, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol Dihydric alcohols such as 2,5-hexanediol, diethanolamine, triethanolamine, di-2-amino-2-hydroxymethyl-1,3-propanediol, tri-2-amino-2-hydroxymethyl-1 , 3-propanediol, poly-2-amino-2-hydroxymethyl-1,3-propanediol, and other amines having a hydroxyl group, and derivatives such as dimers and trimers thereof, 3-methylpentane -1,3,5-triol, 1,2,6-hexanetriol, 2- (2-hydroxypropyl) propane-1,3-diol Trivalent alcohols such as 2-ethyl-2-hydroxymethyl-1,3-propanediol, pentaerythritol, and pentaerythritol dimers such as di-pentaerythritol, tri-pentaerythritol, poly-pentaerythritol, and 3 amounts Pentaerythritol derivatives such as isomers, and trivalent methane dimers, trimers such as tetravalent alcohols, trimethylol methane, di-trimethylol methane, tri-trimethylol methane, poly-trimethylol methane, etc. Methylolmethane derivatives, trimethylolethane, and trimethylolethane dimers such as di-trimethylolethane and tri-trimethylolethane, and trimethylolmethane derivatives such as trimers, trimethylolpropane, and di-trimethylolproper , Trimethylolpropane dimers such as tri-trimethylolpropane, trimethylolpropane derivatives such as trimers, and the like, and trimethylolalkane derivatives such as these trimethylolalkane dimers and trimers, mannitol, sorbitol, fructose Saccharides such as glucose and arabinitol, pentavalent and hexavalent alcohols, or esterified products of these with carboxylic acids such as monocarboxylic acids, dicarboxylic acids, and tricarboxylic acids. As these properties, those in any form such as powder, granule, liquid, paste, and emulsion can be used.

  Among such polyhydric alcohol compounds, glycerin derivatives such as glycerin and diglycerin are preferable because of high compatibility with the PVA resin (A), and among these, glycerin is particularly compatible and non-bleedable. Is preferable.

  The alkylene oxide used in this adduct (B) is a compound having at least one epoxy ring in the molecule. When a compound having one epoxy ring is a monovalent alkylene oxide, it is usually a 1-3 valent alkylene. Oxides, preferably monovalent alkylene oxides. Moreover, it is a C2-C20 polyvalent alkylene oxide, Preferably it is a C2-C10 alkylene oxide, Most preferably, it is a C2-C6 alkylene oxide.

［式中、Ｒ²〜Ｒ⁵は、水素原子または有機基をあらわす。］ Specifically, the monovalent alkylene oxide can be represented by the following general formula (2).

[Wherein R ^{2 to} R ⁵ represent a hydrogen atom or an organic group. ]

R ² to R ⁵ in the general formula (2) are typically hydrogen atoms.
The organic group in the general formula (2) is not particularly limited, and examples thereof include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, and tert-butyl group, and alkenyl groups. Aliphatic hydrocarbon group such as a group, cycloalkyl group such as cyclobutane, cyclopentane and cyclohexane, alicyclic hydrocarbon group such as cycloalkenyl group, halogen atom, hydroxyl group, acyloxy group, alkoxycarbonyl group, carboxyl group, Examples include sulfonic acid groups. Such an organic group is usually an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms, preferably a carbon number. An aliphatic hydrocarbon group having 1 to 5 carbon atoms, an alicyclic hydrocarbon group having 3 to 6 carbon atoms, and particularly preferably an aliphatic hydrocarbon group having 1 to 5 carbon atoms. These hydrocarbon groups may have a substituent such as a halogen group, a hydroxyl group, an ester group, a carboxylic acid group, or a sulfonic acid group, if necessary.

  Specific examples of the epoxy compound represented by the general formula (2) include epoxy butane such as ethylene oxide, propylene oxide, 1,2-epoxybutane, 2,3-epoxybutane, and 3-methyl-1,2-epoxybutane. 1,2-epoxypentane, 2,3-epoxypentane, 3-methyl-1,2-epoxypentane, 4-methyl-1,2-epoxypentane, 4-methyl-2,3-epoxypentane, 3 -Epoxypentanes such as ethyl-1,2-epoxypentane, 1,2-epoxyhexane, 2,3-epoxyhexane, 3,4-epoxyhexane, 3-methyl-1,2-epoxyhexane, 4-methyl -1,2-epoxyhexane, 5-methyl-1,2-epoxyhexane, 3-ethyl-1,2-epoxyhexane, 3-propyl- , 2-epoxyhexane, 4-ethyl-1,2-epoxyhexane, 5-methyl-1,2-epoxyhexane, 4-methyl-2,3-epoxyhexane, 4-ethyl-2,3-epoxyhexane, Epoxyhexanes such as 2-methyl-3,4-epoxyhexane and 2,5-dimethyl-3,4-epoxyhexane, 3-methyl-1,2-epoxyheptane, 4-methyl-1,2-epoxy Heptane, 5-methyl-1,2-epoxyheptane, 6-methyl-1,2-epoxyheptane, 3-ethyl-1,2-epoxyheptane, 3-propyl-1,2-epoxyheptane 3-butyl-1,2-epoxyheptane, 4-ethyl-1,2-epoxyheptane, 4-propyl-1,2-epoxyheptane, 5-ethyl-1,2-epoxyheptane, -Methyl-2,3-epoxyheptane, 4-ethyl-2,3-epoxyheptane, 4-propyl-2,3-epoxyheptane, 2-methyl-3,4-epoxyheptane, 5-methyl -3,4-epoxyheptane, 5-ethyl-3,4-epoxyheptane, 2,5-dimethyl-3,4-epoxyheptane, 2-methyl-5-ethyl-3,4-epoxyheptane 1,2-epoxyheptane, 2,3-epoxyheptane, 3,4-epoxyheptane, and other epoxyheptanes, 1,2-epoxyoctane, 2,3-epoxyoctane, 3,4-epoxyoctane, 4, Epoxy octanes such as 5-epoxyoctane, 1,2-epoxynonane, 2,3-epoxynonane, 3,4-epoxynonane, epoxynonanes such as 4,5-epoxynonane, 1 , 2-epoxydecane, 2,3-epoxydecane, 3,4-epoxydecane, 4,5-epoxydecane, epoxydecane such as 5,6-epoxydecane, 1,2-epoxyundecane, 2,3- Epoxy undecane, 3,4-epoxy undecane, 4,5-epoxy undecane, epoxy undecanes such as 5,6-epoxy undecane, 1,2-epoxy dodecane, 2,3-epoxy dodecane, 3,4-epoxy dodecane, Examples thereof include epoxide decanes such as 4,5-epoxydodecane, 5,6-epoxydodecane, and 6,7-epoxydodecane, and aliphatic epoxy compounds having 2 to 15 carbon atoms.

R ^{8 to} R ¹¹ may be bonded rings, for example, 1,2-epoxycyclopentane, 1,2-epoxycyclohexane, 1,2-epoxycycloheptane, 1,2-epoxycyclooctane, Examples thereof include alicyclic epoxy compounds such as 1,2-epoxycyclononane, 1,2-epoxycyclodecane, 1,2-epoxycycloundecane, and 1,2-epoxycyclododecane.

  Of these, ethylene oxide and propylene oxide are preferable, and ethylene oxide is most preferable.

  In the adduct (B), the content added by the reaction of alkylene oxide with respect to 1 mol of the polyhydric alcohol is, on average, usually 1 to 12 mol, preferably 2 to 9 mol, particularly preferably 2 to 6 mol. is there. In more detail, when the saponification degree of PVA is 100 to 98 mol%, an addition product of 1 to 4 mol is preferable, and when the saponification degree is 88 to 97.9 mol%, 5 to 9 mol addition is performed. Product is preferred. When the content of the alkylene oxide is too small, the spinnability tends to be inferior. When the content is too large, the compatibility with the PVA resin tends to be lowered.

［式中、ｌ，ｏ，ｐは０以上の整数であり、ｌ＋ｏ＋ｐ＝２〜６である。］ Most preferred as the adduct (B) is a compound in which ethylene oxide is added to glycerin, and is the compound (3) shown below.
Examples of commercially available products containing such an adduct (B) include “Uniox G-150” and “Uniox G-180” manufactured by Nippon Oil & Fats Co., Ltd.

[Wherein, l, o, p are integers of 0 or more, and l + o + p = 2-6. ]

  The method for reacting the above polyhydric alcohol and alkylene oxide is not particularly limited. For example, using a strong base such as an alkali metal hydroxide such as potassium hydroxide or sodium hydroxide or an alkoxide such as potassium methoxide or sodium methoxide as a catalyst, the mixture is heated and melted together with the polyhydric alcohol, and alkylene oxide is blown into this. There is a method of adding by dropping.

  The ratio of the component (A) and the component (B) in the PVA resin composition used for the fiber of the present invention is usually 80/20 to 98/2, preferably 90/10 to 98/2, in weight ratio. Preferably, it is 95/5 to 98/2. When the amount of the component (B) is too small, yarn breakage occurs during melt spinning, and the stretchability tends to be inferior. When the amount is too large, the strength tends to decrease. Moreover, there is a possibility of bleeding on the surface of the molded product.

  The resin composition used for the fiber of the present invention can be used by blending known additives in a proportion of 20% by weight or less. Examples of such additives include aliphatic polyhydric alcohols such as glycerin, ethylene glycol, and hexanediol, plasticizers such as sugar alcohols such as sorbitol, mannitol, and pentaerythritol, stearic acid amide, ethylenebisstearic acid amide, and the like. Saturated aliphatic amide compounds, unsaturated aliphatic amide compounds such as oleic acid amide, aliphatic metal salts such as calcium stearate, magnesium stearate, zinc stearate, low molecular weight ethylene having a molecular weight of about 500 to 10,000, and low molecular weight propylene Lubricants such as low molecular weight polyolefins, etc., and inorganic acids such as boric acid and phosphoric acid, antioxidants, heat stabilizers, light stabilizers, UV absorbers, colorants, antistatic agents, surfactants, preservatives Antibacterial agent, antiblocking agent, slip agent, filler, etc. Gerare, which are appropriately blended as required.

  In order to prepare the resin composition used for the fiber of the present invention, the PVA resin (A) and the adduct (B) are dry blended in advance and then melt-kneaded and pelletized, or separately in a melt-kneader. A method of kneading while charging at a constant ratio and pelletizing can be mentioned.

  Melting | fusing point of the resin composition used for the fiber of this invention is 70-220 degreeC normally, Preferably it is 130 degreeC or more and less than 200 degreeC, Most preferably, it is 150-180 degreeC. The decomposition start temperature of the PVA-based resin (A) in the present invention is usually 230 to 250 ° C., and the melting point is significantly lower than this temperature. Therefore, even if molding processing is performed at a high temperature, the resin composition The fiber can be made without deterioration.

  The melt flow rate (MFR, 190 ° C., load 2160 g) of the resin composition used for the fiber of the present invention is usually 10 to 100 g / min, further 15 to 80 g / min, and particularly preferably 20 to 50 g / min. If the MFR is too large, the fiber strength decreases, and if it is too small, the stretchability tends not to increase. The MFR of the present invention can be determined according to JIS K 7210.

Next, the manufacturing method of the fiber of this invention is demonstrated.
The spinning method is not particularly limited, and examples thereof include a method of spinning from a single nozzle or a composite nozzle using a known melt spinning machine.
The spinning temperature may be a temperature at which the resin composition melts and does not deteriorate. Such temperature is usually 120 to 230 ° C., preferably 150 ° C. or more and less than 210 ° C., particularly preferably 170 to 190 ° C. If the temperature is too high, decomposition of the resin itself starts, and if it is too low, the torque of the extruder tends to be too high and the melt molding tends to be impossible.

  The fiber of the present invention is usually spun as a single fiber, but in order to improve the strength and flexibility when it is made into a woven or non-woven fabric and to impart surface hydrophilicity, a fiber containing a water-soluble removal portion is used. In order to spin, you may spin as a composite fiber with thermoplastic resins other than the resin composition of this application. Hereinafter, the resin composition of the present application in the composite fiber is abbreviated as (α) component, and the thermoplastic resin is abbreviated as (β) component. The composite fiber referred to in the present application means a fiber in which two or more types of resins having different components exist in a single fiber, and may be a monofilament or a multifilament.

  In the case of a composite fiber, the thermoplastic resin to be combined is not particularly limited, and is a polyester polymer such as polyethylene terephthalate or polybutylene terephthalate, a polyamide polymer such as nylon 6 or nylon 66, polypropylene, polymethylpentene, or the like. One or two or more of homopolymers, copolymers, and terpolymers such as polyolefin polymers can be selected and used.

  The cross-sectional shape of the fiber is not particularly limited, and may be any shape such as a circular shape, an elliptic shape, a hollow shape, a triangular shape, a quadrangular shape, a rhombus shape, a star shape, and a flat shape. Examples of the shape of the composite fiber include a core-sheath composite fiber, an eccentric sheath-core composite fiber, a parallel composite fiber, a split composite fiber, and a sea-island composite fiber.

  In the case of the core-sheath type, either the case where the sheath part is the (α) component, the core part is the (β) component, or the case where the sheath part is the (β) component and the core part is the (α) component can be adopted. It is. When the surface hydrophilicity is required, the sheath portion becomes the (α) component and the core portion becomes the (β) component, and the hydrophilic fiber having stretchability and strength is completed. Moreover, when calculating | requiring a hollow fiber, a sheath part may become ((beta)) component, a core part may become ((alpha)) component, and multiple cores may exist. Next, various hollow fibers can be produced by dissolving the core portion in water.

  In the case of the division type, it is possible to adopt either the case where the (β) component is divided into a plurality of segments by the (α) component or the case where the (β) component is divided into a plurality of segments by the (α) component. However, the (β) component is preferably divided into a plurality of segments by the (α) component. A known shape can be adopted as the divided shape, but it is usually one that is radially divided into even numbers, and preferably one that is radially divided into four to eight.

In addition, in the case of the sea-island structure, the fiber whose water solubility, hydrophilicity and water resistance are controlled by adjusting the distribution ratio by using the (α) component and (β) component for the sea and island components. Can be made. Further, when the island component is the (α) component, the surface of the fiber can be modified by dissolving the portion with water and removing it.
As described above, by performing mixed spinning including the (α) component, functional fibers (hollow) obtained by controlling the water solubility of the fiber, improving the texture, improving the surface, and dissolving and removing the (α) component in water. Various fibers can be created. Furthermore, the functionality can be controlled by adjusting the component ratio.

  The composite ratio (volume ratio) of the resin composition (α) of the present invention and the thermoplastic resin (β) in the composite fiber is usually 1/9 to 9/1, preferably 2/8 to 8/2, in particular. Preferably, it is 3/7 to 7/3, and is adjusted as appropriate so as to obtain physical properties suitable for the intended final product. If the composite ratio of the resin composition of the present invention is too small, hydrophilicity cannot be exhibited at all, and conversely if too large, it tends to dissolve in water or become dispersed.

  The obtained fiber is stretched as necessary. At that time, the stretching temperature is usually 75 to 190 ° C., and the stretching ratio is usually 1.5 to 8 times.

  Moreover, the obtained fiber may be crimped by a crimping device as necessary, and may be cut into a predetermined length.

  The fiber degree and fiber diameter of the fiber are not particularly limited, and preferred values are selected according to the molding method and application, but the fiber degree is usually 0.01 to 10 denier, preferably 0.1. ˜4 denier, and the fiber diameter is usually 0.1 to 50 μm, preferably 1 to 20 μm. However, for special applications, fiber diameters in the ultrafine / nanofiber region may be produced. By setting in such a range, fiber strength, flexibility, and water solubility can be obtained, and in particular, there is an effect that both strength when used as a woven fabric for chemical lace base material and good water solubility at low temperature are compatible. It becomes like this.

  In addition, although the fiber of this invention is normally used as a nonwoven fabric or a woven fabric, it is desirable to use as a nonwoven fabric especially. Further, it may be used as a single fiber and may be used in a form of being wound around a hollow or plate-like substrate.

  The method of creating a nonwoven fabric using the obtained fibers is not particularly limited, and the form of the nonwoven fabric is a dry web obtained by a card method, an air lay method or the like, a wet web obtained by a wet method alone, or these Non-woven fabric obtained by laminating two or more layers including at least one layer by mechanical entanglement processing such as needle punch method or spunlace method, thermal bonding method such as hot roll method, hot air bonding method, ultrasonic bonding method, or a combination thereof Is created.

  Moreover, the resin composition used as the fiber of the present invention is suitable for a molding method such as a spun bond method or a melt blown method in which a nonwoven fabric is directly formed from the resin composition. The spunbond method is a method in which a polymer is melt-kneaded by a melt extruder, the melted polymer stream is guided to a spinning head and discharged from a nozzle hole, the discharged yarn is cooled by a cooling device, and then an air jet nozzle or the like. Using a suction device, pull it with a high-speed air current to achieve the desired fineness, and then deposit it on a movable collection surface while opening the fiber to form a web. This is a method for obtaining a long-fiber nonwoven fabric by winding the wire. Among these, the spunbond method is preferably used because it can be produced directly from the raw material, and since it is a long fiber, a nonwoven fabric excellent in strength can be obtained.

  For example, the fiber web may be spunlaced to divide the split composite fiber to form ultrafine fibers having a fineness of 0.5 denier or less and to entangle the fibers.

The basis weight and apparent density of the nonwoven fabric thus obtained are not particularly limited, but the basis weight is usually 15 to 200 g / m ² , preferably 20 to 100 g / m ² , particularly preferably 30 to 80 g / m. ² If the basis weight is too small, if the base fabric for embroidery is used as a nonwoven fabric, there will be a problem that the embroidery needle breaks, and the texture tends to be lacking. There is a tendency for strength to become weaker.

  The nonwoven fabric made of the fibers of the present invention thus obtained has excellent water solubility as one of its characteristics. Therefore, for example, when such a nonwoven fabric is used as a base material for embroidery such as that for a chemical lace base material, the base material dissolves in water at a low temperature, so that discoloration of the embroidery itself and deterioration of the embroidery thread are suppressed. . In addition, various uses that require good water solubility and hydrophilicity as non-woven fabrics, for example, protective materials for scratches in clothes, automobiles, filtration filters, undissolved paper for confidential documents, detergents, softeners, and agricultural chemicals. It is also useful for applications such as medical bags and medical surgical clothes.

  Next, the present invention will be described in more detail with reference to examples. The present invention is not limited to the following examples as long as the gist thereof is not exceeded. Hereinafter, “parts” and “%” are based on weight.

Production Example 1
In a reaction vessel equipped with a reflux condenser, a dropping funnel, and a stirrer, 68.5 parts of vinyl acetate, 20.5 parts of methanol, 11.0 parts of 3,4-diacetoxy-1-butene (8 mol% vs. charged vinyl acetate) Was added under the conditions of an initial charge rate of 10% for vinyl acetate, a constant rate of dropwise addition of vinyl acetate and 3,4-diacetoxy-1-butene for 9 hours, and 0.3 mol% of azobisisobutyronitrile (relative to the charged vinyl acetate). ) And the temperature was raised under nitrogen flow while stirring to initiate polymerization. When the polymerization rate of vinyl acetate reaches 90%, a predetermined amount of m-dinitrobenzene is added to complete the polymerization, and then unreacted vinyl acetate monomer is removed from the system by blowing methanol vapor. A methanol solution of the copolymer was obtained.

  Next, the methanol solution was diluted with methanol, adjusted to a concentration of 45%, and charged into a kneader. While maintaining the solution temperature at 35 ° C., a 2% methanol solution of sodium hydroxide was added to the vinyl acetate structural unit in the copolymer and Saponification was carried out for 4 hours by adding 10.5 mmol with respect to 1 mol of the total amount of 3,4-diacetoxy-1-butene structural units. When saponification progresses as saponification progresses and becomes particulate, it is separated by solid-liquid separation, washed well with methanol and dried in a hot air dryer at 70 ° C. for 12 hours to achieve the target PVA System resin was produced.

The saponification degree of the obtained PVA-based resin (A1) was 98.9 mol% when analyzed by the alkali consumption required for hydrolysis of residual vinyl acetate and 3,4-diacetoxy-1-butene. . Moreover, the average degree of polymerization was 300 when analyzed according to JIS K 6726. The melting point was 168 ° C. as measured by a differential thermal analyzer DSC. The content of the 1,2-diol structural unit represented by the formula (1a) is ¹ H-NMR (300 MHz proton NMR, d6-DMSO solution, internal standard substance: tetramethylsilane, 50 ° C.). It was 8 mol% when computed from the measured integral value. (See [Figure 1])

また、主鎖に直接結合する水酸基を示すピークは、ａ₁（４．６ｐｐｍ），ａ₂（４．４ｐｐｍ），ａ₃（４.２ｐｐｍ）で表され、主鎖のメチレンを示すピークは、ｂ₁（１.０〜１．７ｐｐｍ）で表される。
変性度は、それぞれのピークの積分値より、下記式にて求めた。 [Calculation method of content of 1,2-diol structural unit]
^{In 1} H-NMR, the peaks indicating 1,2-diol represented by the structural formula (1) are A (4.2 to 4.3 ppm) and B (3.4 to 3.6 ppm) in FIG. ) And C (1.7 to 1.9 ppm). This corresponds to the proton shown in the following chemical formula (1a ′).

The peak showing a hydroxyl group bonded directly to the main chain, a ₁ (4.6 ppm), is represented by _{a 2 (4.4ppm), a 3} (4.2ppm), a peak indicating the methylene main chain, It is represented by b ₁ (1.0 to 1.7 ppm).
The degree of denaturation was determined from the integral value of each peak according to the following formula.

Production Example 2
In a reaction vessel equipped with a reflux condenser, a dropping funnel, and a stirrer, 68.0 parts of vinyl acetate, 23.8 parts of methanol, 8.2 parts of 3,4-diacetoxy-1-butene (6 mol% to charged vinyl acetate) Was added under the conditions of an initial charge rate of 10% for vinyl acetate, a constant rate of dropwise addition of vinyl acetate and 3,4-diacetoxy-1-butene for 9 hours, and 0.3 mol% of azobisisobutyronitrile (relative to the charged vinyl acetate). ) And the temperature was raised under nitrogen flow while stirring to initiate polymerization. When the polymerization rate of vinyl acetate reaches 90%, a predetermined amount of m-dinitrobenzene is added to complete the polymerization, and then unreacted vinyl acetate monomer is removed from the system by blowing methanol vapor. A methanol solution of the copolymer was obtained.

  Next, the methanol solution was diluted with methanol, adjusted to a concentration of 45%, and charged into a kneader. While maintaining the solution temperature at 35 ° C., a 2% methanol solution of sodium hydroxide was added to the vinyl acetate structural unit in the copolymer and Saponification was carried out for 4 hours by adding 10.5 mmol with respect to 1 mol of the total amount of 3,4-diacetoxy-1-butene structural units. When saponification progresses as saponification progresses and becomes particulate, it is separated by solid-liquid separation, washed well with methanol and dried in a hot air dryer at 70 ° C. for 12 hours to achieve the target PVA System resin was produced.

The saponification degree of the obtained PVA-based resin (A2) was 98.9 mol% when analyzed by the alkali consumption required for hydrolysis of residual vinyl acetate and 3,4-diacetoxy-1-butene. . Moreover, the average degree of polymerization was 300 when analyzed according to JIS K 6726. The content of the 1,2-diol structural unit represented by the formula (1a) was 6 mol% when calculated by ¹ H-NMR (internal standard substance: tetramethylsilane). And the melting | fusing point was 190 degreeC.

Production Example 3
In a reaction vessel equipped with a reflux condenser, a dropping funnel, and a stirrer, 68.3 parts of vinyl acetate, 20.8 parts of methanol, 10.9 parts of 3,4-diacetoxy-1-butene (8 mol% to charged vinyl acetate) Was added under the conditions of an initial charging rate of 10% for vinyl acetate, a constant rate of dropwise addition of vinyl acetate and 3,4-diacetoxy-1-butene for 9 hours, and 0.26 mol% of azobisisobutyronitrile (relative to the charged vinyl acetate). ) And the temperature was raised under nitrogen flow while stirring to initiate polymerization. When the polymerization rate of vinyl acetate reaches 90%, a predetermined amount of m-dinitrobenzene is added to complete the polymerization, and then unreacted vinyl acetate monomer is removed from the system by blowing methanol vapor. A methanol solution of the copolymer was obtained.

  Next, the methanol solution was diluted with methanol, adjusted to a concentration of 45%, and charged into a kneader. While maintaining the solution temperature at 35 ° C., a 2% methanol solution of sodium hydroxide was added to the vinyl acetate structural unit in the copolymer and Saponification was carried out for 2 hours by adding 7.0 mmol with respect to 1 mol of the total amount of 3,4-diacetoxy-1-butene structural unit. When saponification progresses as saponification progresses and becomes particulate, it is separated by solid-liquid separation, washed well with methanol and dried in a hot air dryer at 70 ° C. for 12 hours to achieve the target PVA System resin was produced.

The saponification degree of the obtained PVA-based resin (A3) was 96.0 mol% when analyzed by the alkali consumption required for hydrolysis of residual vinyl acetate and 3,4-diacetoxy-1-butene. . Moreover, the average degree of polymerization was 300 when analyzed according to JIS K 6726. The content of the 1,2-diol structural unit represented by the formula (1a) was 8 mol% when calculated by ¹ H-NMR (internal standard substance; tetramethylsilane). The melting point was 158 ° C.

Production Example 4
In a reaction vessel equipped with a reflux condenser, a dropping funnel and a stirrer, 68.5 parts of vinyl acetate, 27.4 parts of methanol, 4.1 parts of 3,4-diacetoxy-1-butene (3 mol% vs. charged vinyl acetate) Was added under the conditions of an initial charge rate of 10% for vinyl acetate, a constant rate of dropwise addition of vinyl acetate and 3,4-diacetoxy-1-butene for 9 hours, and 0.22 mol% of azobisisobutyronitrile (relative to the charged vinyl acetate). ) And the temperature was raised under nitrogen flow while stirring to initiate polymerization. When the polymerization rate of vinyl acetate reaches 90%, a predetermined amount of m-dinitrobenzene is added to complete the polymerization, and then unreacted vinyl acetate monomer is removed from the system by blowing methanol vapor. A methanol solution of the copolymer was obtained.

  Next, the methanol solution was diluted with methanol, adjusted to a concentration of 45%, and charged into a kneader. While maintaining the solution temperature at 35 ° C., a 2% methanol solution of sodium hydroxide was added to the vinyl acetate structural unit in the copolymer and Saponification was carried out for 2.5 hours by adding 4.0 mmol with respect to 1 mol of the total amount of 3,4-diacetoxy-1-butene structural units. When saponification progresses as saponification progresses and becomes particulate, it is separated by solid-liquid separation, washed well with methanol and dried in a hot air dryer at 70 ° C. for 12 hours to achieve the target PVA System resin was produced.

The saponification degree of the obtained PVA-based resin (A4) was 88.8 mol% when analyzed by the alkali consumption required for hydrolysis of residual vinyl acetate and 3,4-diacetoxy-1-butene. . Moreover, the average degree of polymerization was 300 when analyzed according to JIS K 6726. The content of the 1,2-diol structural unit represented by the formula (1a) was 3 mol% when calculated by ¹ H-NMR (internal standard substance; tetramethylsilane). The melting point was 175 ° C.

Example 1
(Preparation of polyvinyl alcohol resin composition)
As PVA-based resin (A), A1 is used, and as alkylene oxide adduct (B) of polyhydric alcohol, a compound obtained by reacting 2 mol% of ethylene oxide with glycerin (“Uniox G-180” manufactured by NOF Corporation) ), 95 parts by weight of component (A), 5 parts by weight of component (B), ie, (A) / (B) = 95/5 weight ratio, and using a twin screw extruder The pellets were melt extruded at a resin temperature of 190 ° C. under the following conditions. The obtained resin composition was evaluated as follows.

Pelletizing conditions Extruder: Single screw extruder (15mmφ L / D = 60)
Screw pattern = full flight CR = 3.12
Temperature pattern: C1 / C2 / C3 / C4 / C5 / C6 / C7 / C8 / D
= 90/120/150/170/180/180 /
190/190/190 ° C
Screen mesh: 90/90
Screw pattern: Full flight Screw rotation speed: 250rpm
Others: vacuum vent cooling belt pelletizer

[Evaluation]
<MFR>
MFR (190 degreeC, load 2160g) measurement was performed using the obtained pellet. The results are shown in Table 2.

<Melting point>
The melting point was measured by DSC. The results are shown in Table 2. The measurement conditions are shown below.
FirstRun: -30 to 215 ° C, (temperature increase of 10 ° C / min)
SecondRun: -30 to 230 ° C, (temperature increase of 10 ° C / min)

The obtained resin composition was melt-spun at 190 ° C. using an apparatus as shown in FIG.
Extruder: Single screw extruder (30mmφ L / D = 22)
Screw pattern = full flight CR = 3.12
Temperature pattern: C1 / C2 / C3 / C4 / A / D
= 170/180/190/190/190/190 ° C
Spinning head diameter: 0.5 mmφ Number of spinning 12 holes Mesh: 4 layers (80/100/250/50 mesh)
Discharge rate: 0.7 g / min (per hole)

[Evaluation]
<Spinning take-up speed>
The fiber when the yarn breakage occurs at the lowest air pressure by changing the air pressure of the spinning nozzle at 1.0 kg / cm ² , 2.5 kg / cm ² , and 4.5 kg / cm ² stepwise during spinning. The spinning take-up speed was calculated from the diameter using the following formula. The results are shown in Table 2.
In the formula, the specific gravity is 1.2 and the unit of discharge amount is (g / min).

The obtained fiber was evaluated as follows.
[Evaluation]
<Fiber diameter>
The diameter of the obtained fiber was measured. The results are shown in Table 2.

<Processability>
Regarding the workability when the resin obtained above is melt-molded, the torque stability in the extruder, the fluctuation of the discharge amount when discharged from the extruder, the volatility of the plasticizer, the occurrence of spears, the heat during spinning The long run properties such as generation of deteriorated products and cross-linked gel, clogging of the filter and no thread breakage were comprehensively evaluated.
A: Spinning was possible, and spinning was possible without problems.
○: Spinning is possible, but discharge was unstable.
△ ・ ・ ・ Spinning is possible, but plasticizer volatilization (smoke) and eye cracks occur.
Spinning work for a long time was not possible.
X: Frequent yarn breakage occurred and spinning was impossible.

<Fiber texture>
Five panelists touched the fiber bundle obtained by using the resin composition of the present invention by hand, and evaluated the feel of the fiber bundle in comparison with the polypropylene resin fiber bundle.
◎ ・ ・ ・ The fiber was soft and the surface was smooth.
A: The softness of the fibers was slightly lacking, and it was a hard touch.
X: The fiber itself was wet and had a sticky feel.

<Smell of fiber>
Five panelists sniffed the fiber bundles obtained using the resin composition of the present invention and evaluated the degree of odor.
◎ ・ ・ ・ Odorless.
○ ... Slightly deteriorated odor.
X: Thermally deteriorated odor and acetic acid odor were clearly found.

Example 2
In Example 1, as PVA-type resin (A), except having used A2, the fiber was obtained similarly and evaluated similarly.

Example 3
In Example 1, A3 is used as the PVA resin (A), the component (A) is 90 parts by weight, the component (B) is 10 parts by weight, that is, (A) / (B) = 90/10 weight ratio. The fibers were obtained in the same manner except that they were blended so as to be evaluated in the same manner.

Example 4
In Example 1, A3 was used as the PVA resin (A), and a compound obtained by reacting 6 mol% of ethylene oxide with glycerin was used as the adduct (B). Further, 98 parts by weight of the component (A) and (B) Fibers were obtained in the same manner except that the components were blended in an amount of 2 parts by weight, that is, (A) / (B) = 98/2, and evaluated in the same manner.

Example 5
In Example 1, fibers were obtained in the same manner except that A3 was used as the PVA resin (A), and a compound obtained by reacting 3 mol% of ethylene oxide with glycerin was used as the adduct (B). went.

Example 6
In Example 1, fibers were obtained in the same manner except that A3 was used as the PVA resin (A) and a compound obtained by reacting 4 mol% of ethylene oxide with glycerin was used as the adduct (B). went.

Example 7
In Example 1, A4 was used as the PVA resin (A), a compound obtained by reacting 6 mol% of ethylene oxide with glycerin as the adduct (B), 98 parts by weight of the component (A), and (B) Fibers were obtained in the same manner except that the components were blended in an amount of 2 parts by weight, that is, (A) / (B) = 98/2, and evaluated in the same manner.

Comparative Example 1
In Example 1, fibers were obtained in the same manner except that an unmodified polyvinyl alcohol resin not containing the structural unit represented by the structural formula (1a) was used as the PVA-based resin (A), and evaluation was performed in the same manner. It was.

Comparative Example 2
A fiber was obtained in the same manner as in Example 1 except that the alkylene oxide adduct (B) of polyhydric alcohol was not blended, and evaluation was performed in the same manner.

Comparative Example 3
In Example 3, fibers were obtained in the same manner except that glycerin (“RG” manufactured by Nippon Oil & Fats Co., Ltd.) was used instead of the adduct (B), and evaluation was performed in the same manner.

Comparative Example 4
In Example 1, fibers were obtained in the same manner except that polyethylene glycol having a polymerization degree of 300 ("PEG300" manufactured by Nippon Oil & Fats Co., Ltd.) was used instead of the alkylene oxide adduct (B) of the polyhydric alcohol. Evaluation was performed.

From the above results, all of the examples had a resin composition with a low melting point, good workability when spinning at 190 ° C., and could be spun even at a high spinning take-up speed. As a result, a fiber having a thin fiber diameter, which was not obtained conventionally, was obtained. Such fibers were excellent fibers with good texture and no odor.
From this, it can be easily estimated that the nonwoven fabric obtained by directly molding such a fiber by, for example, the spunbond method has excellent moldability, excellent strength, and excellent water solubility because of its small fiber diameter. Is.
However, Comparative Example 1 using general PVA which was not modified at all could not be melt-spun at 190 ° C. Further, in Comparative Example 2 using only the PVA containing the structural unit represented by the structural formula (1a) not containing the polyhydric alcohol alkylene oxide adduct (B), the resin composition was in a semi-unmelted state. The yarn breakage occurred frequently and could not be spun.

  The fiber of the present invention is used as a nonwoven fabric in various applications that require good water solubility and hydrophilicity, for example, embroidery substrates for clothes, chemical laces, etc., scratch protection protecting materials for automobiles, filtration filters, and confidential texts. It is useful for paper, detergents, softeners, pesticide bags, medical surgical clothes, etc.

2 is an NMR chart obtained in Production Example 1. It is a schematic diagram which shows the structure of the apparatus used for the spinning in an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Extruder 2 Spinning head 3 Take-up device 4 Fiber

Claims (6)

A fiber comprising a polyvinyl alcohol resin (A) having a 1,2-diol structural unit represented by the following general formula (1) and an alkylene oxide adduct (B) of a polyhydric alcohol.

  The fiber according to claim 1, wherein the polyvinyl alcohol resin (A) is obtained by saponifying a copolymer of a vinyl ester monomer and 3,4-diacyloxy-1-butene.   The fiber according to claim 1 or 2, wherein the alkylene oxide adduct (B) of polyhydric alcohol has an average addition amount of alkylene oxide of 1 to 12 moles per mole of polyhydric alcohol.   The ratio of the polyvinyl alcohol-based resin (A) and the polyhydric alcohol alkylene oxide adduct (B) is (A) / (B) = 80/20 to 98/2 in weight ratio. The fiber according to any one of claims 1 to 3.   The fiber according to any one of claims 1 to 4, wherein the fiber has a diameter of 0.1 µm to 50 µm.   The nonwoven fabric which consists of a fiber in any one of Claims 1-5.

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