JP6727084B2 - Fiber assembly and method for manufacturing the same - Google Patents

Description

The present invention relates to a fiber assembly and a method for manufacturing the fiber assembly. In particular, the present invention relates to a fiber aggregate having excellent solvent resistance and waterproofness and a method for producing the same.

When a fiber aggregate such as a nonwoven fabric containing fibers obtained by dry spinning a spinning solution in which a polymer is dissolved in an organic solvent is brought into contact with an organic solvent, the fibers are dissolved and the shape of the fiber aggregate cannot be maintained. There is a problem that the intended use is limited.

For example, even if the fiber assembly as described above is used as a separator for an electric double layer capacitor, the electrolytic solution of the electric double layer capacitor consists of an organic solvent, so the fiber assembly is dissolved in the organic solvent, and the separator There was a case where it did not work as.

Therefore, the applicant of the present application has proposed "a fiber assembly composed of fibers in which a first polymer soluble in an organic solvent is coated with a second polymer insoluble in the organic solvent" (Patent Document 1), and this second It has been disclosed that polyvinyl alcohol is used as the polymer, and specifically, that completely saponified polyvinyl alcohol and a methyl vinyl ether/maleic anhydride copolymer are used as the second polymer.

Since the first polymer soluble in the organic solvent is coated with the second polymer insoluble in the organic solvent, this fiber assembly can maintain its shape without being dissolved even when the organic solvent is heated. Although it was excellent in resistance to organic solvents, when the second polymer containing polyvinyl alcohol is used, it dissolves even with a small amount of moisture such as sweat from the hands, which makes it difficult to handle and requires waterproofing. There was a problem that it could not be used in the intended use. For example, use a non-woven fabric containing fibers having polyvinyl alcohol or polyvinyl alcohol and a methyl vinyl ether/maleic anhydride copolymer as the second polymer as the second polymer as a base fabric for an adhesive patch coated with a water-based drug. However, since the water content of the water-based drug penetrates into the non-woven fabric, it cannot be actually used as a patch base fabric.

JP, 2011-69011, A

The present invention has been made under such circumstances, and an object of the present invention is to provide a fiber assembly having excellent organic solvent resistance and waterproofness, and a method for producing the same.

The fiber assembly of the present invention is a fiber assembly comprising a fiber in which a first polymer soluble or hydrophilic in an organic solvent is coated with a second polymer, and the second polymer is polyvinyl alcohol, a carboxyl group or It is a polymer containing a non-hydroxyl group and a polymer in which an amine or a quaternary ammonium having an alkyl group having 6 or more carbon atoms is bonded.

Further, the method for producing a fiber assembly of the present invention comprises a step of forming a precursor fiber assembly containing a precursor fiber composed of a first polymer soluble or hydrophilic in an organic solvent, polyvinyl alcohol, a carboxyl group or a non-hydroxyl group. A step of coating the precursor fiber assembly with a solution containing a polymer and an amine or a quaternary ammonium having an alkyl group having 6 or more carbon atoms, polyvinyl alcohol in the solution, a polymer containing a carboxyl group or a non-hydroxyl group, And a step of binding an amine or a quaternary ammonium having an alkyl group having 6 or more carbon atoms.

In the fiber assembly of the present invention, the surface of the fiber is composed of polyvinyl alcohol, a polymer containing a carboxyl group or a non-hydroxyl group, and a polymer in which an amine having an alkyl group having 6 or more carbon atoms or a quaternary ammonium is bonded. Therefore, it has excellent organic solvent resistance and waterproofness.

In the method for producing a fiber assembly of the present invention, the fiber surface is coated with a solution containing polyvinyl alcohol, a polymer containing a carboxyl group or a non-hydroxyl group, and an amine having an alkyl group having 6 or more carbon atoms or a quaternary ammonium. Since these are combined, a fiber assembly having excellent organic solvent resistance and waterproofness can be manufactured.

The fibers constituting the fiber assembly of the present invention include a first polymer soluble or hydrophilic in an organic solvent, polyvinyl alcohol, a polymer containing a carboxyl group or a non-hydroxyl group, and an amine having an alkyl group having 6 or more carbon atoms, or Since it is coated with the second polymer to which quaternary ammonium is bonded, it has excellent organic solvent resistance and waterproofness.

One of the first polymers is soluble in an organic solvent so that the spinning solution dissolved in the organic solvent can be dry-spun. The first polymer is not particularly limited as long as it is soluble in an organic solvent. For example, polyester, acrylic resin (eg, polyacrylonitrile, acrylonitrile copolymer), polymethacrylic acid, polymethacryl Methyl acid, polycarbonate, polystyrene, polyamide, polyimide, polyolefin resin (for example, polyethylene, polypropylene, etc.), polyethersulfone, polysulfone, fluorine resin (for example, polyvinylidene fluoride, polyvinylidene fluoride copolymer, etc.), polyurethane, para Alternatively, a meta-aramid or the like can be used. The first polymer soluble in the organic solvent does not have to be one type, and two or more types may be mixed.

The organic solvent varies depending on the type of the first polymer and is not particularly limited as long as it is soluble in the first polymer. For example, acetone, methanol, ethanol, propanol, isopropanol, tetrahydrofuran, dimethyl sulfoxide, 1, 4-dioxane, pyridine, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, acetonitrile, formic acid, toluene, benzene, cyclohexane, cyclohexanone, carbon tetrachloride, methylene chloride, chloroform, trichloroethane. , Ethylene carbonate, diethyl carbonate, propylene carbonate, methyl ethyl ketone, and the like. The organic solvent does not have to be one kind, and may be a mixed solvent of two or more kinds.

In the present invention, "soluble in an organic solvent" means that a polymer is added to an organic solvent in an amount of 100 times the mass of the polymer, and in the case of an organic solvent having a boiling point of 100°C or lower, (boiling point-10)°C is 100%. In the case of an organic solvent having a boiling point higher than 0°C, it means that the mass is reduced by 70% or more when heating is continued at 100°C for 60 minutes.

The other first polymer is hydrophilic so that it has a good affinity with the second polymer. The term “hydrophilic” in the present invention means that the contact angle of water in the film state of the polymer is 90° or less. The contact angle in the present invention means a value measured by a dynamic contact angle measuring device (DM500 manufactured by Kyowa Interface Science Co., Ltd.).

The first polymer is not particularly limited as long as it is hydrophilic, but examples thereof include polyvinyl alcohol, maleic anhydride copolymer, polyethylene oxide, polyacrylic acid, poly-N-vinylpyrrolidone, and polyacrylamide. , Epoxy resin, cellulose, starch, pullulan, chitin, chitosan, gelatin, protein, inorganic polymer and the like.

Since such a first polymer soluble in an organic solvent or a hydrophilic first polymer is not soluble in an organic solvent or waterproof and cannot be applied to various uses, in the present invention, a polyvinyl alcohol or a carboxyl group is used. Alternatively, a fiber coated with a polymer containing a non-hydroxyl group and a second polymer to which an amine or a quaternary ammonium having an alkyl group having 6 or more carbon atoms is bonded (hereinafter, may be referred to as "PVA-based coated fiber"). By including the fiber assembly, the fiber assembly is excellent in organic solvent resistance and waterproofness. That is, mainly, polyvinyl alcohol and a polymer containing a carboxyl group or a non-hydroxyl group are bonded to an amine or a quaternary ammonium having an organic solvent resistance and a strongly hydrophobic alkyl group having 6 or more carbon atoms. As a result, since the PVA-based coated fiber is excellent in hydrophobicity, the fiber assembly containing the PVA-based coated fiber is excellent in organic solvent resistance and waterproofness.

As this polyvinyl alcohol, a polyvinyl alcohol-based polymer having a vinyl alcohol unit can be used. Usually, polyvinyl alcohol cannot be directly polymerized from vinyl alcohol, so that polyvinyl alcohol produced by saponifying a vinyl acetate polymer can be used. In the present invention, partially saponified polyvinyl alcohol in which vinyl acetate remains may be used in addition to 100 mol% saponified polyvinyl alcohol. The degree of saponification of the partially saponified polyvinyl alcohol is not particularly limited, but is preferably 50 mol% or more, more preferably 65 mol% or more, and further preferably 80 mol% or more. Further, even reacetic acid having a saponification degree in these ranges can be used. A cation-modified polyvinyl alcohol formed by reacting a low molecular weight compound having a quaternary ammonium group or a reactive group such as an aldehyde group with polyvinyl alcohol is used. You can also do it. However, since the cation-modified polyvinyl alcohol may decompose to generate an odor, unmodified polyvinyl alcohol (100 mol% saponified polyvinyl alcohol, partially saponified polyvinyl alcohol, or reacetic acid product) is preferable.

The average degree of polymerization of the polyvinyl alcohol of the present invention is not particularly limited, but is preferably 80 or more, more preferably 100 or more, and 120 so that the strength of the PVA-based coated fiber is excellent. The above is more preferable. Further, if the average degree of polymerization is too high, the solubility in a solvent may be lowered and the productivity may be deteriorated, so that it is preferably 30,000 or less, more preferably 20,000 or less, It is more preferably 000 or less. In the present invention, both "saponification degree" and "average degree of polymerization" refer to values measured according to JIS K6726. Even if the degree of saponification is less than about 70 mol%, the value is measured according to the JIS standard.

The second polymer constituting the PVA-based coated fiber of the present invention is bound with a polymer containing a carboxyl group or a non-hydroxyl group in addition to the above-mentioned polyvinyl alcohol. The carboxyl group of the polymer containing the carboxyl group, or the carboxyl group generated from the polymer containing a non-hydroxyl group is ester-bonded with the hydroxyl group of polyvinyl alcohol to form a crosslinked structure between the polyvinyl alcohol and the polymer containing a carboxyl group or a non-hydroxyl group. Therefore, it is considered that the organic solvent resistance and water resistance of the PVA-based coated fiber are improved.

The polymer containing a carboxyl group is not particularly limited, but a carboxyl group-containing acrylic resin or methacrylic resin can be preferably used. For example, in addition to polyacrylic acid and polymethyl methacrylate, (meth) ) It may be an acrylic copolymer or a methacrylic copolymer in which an acrylate and an ethylenically unsaturated carboxylic acid, and optionally other copolymerizable monomers are copolymerized. Here, as the (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth) ) Acrylate, benzyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, glycidyl (meth)acrylate and the like.

The ethylenically unsaturated carboxylic acid may be a monocarboxylic acid such as acrylic acid, methacrylic acid or crotonic acid, a dicarboxylic acid such as maleic acid, fumaric acid or itaconic acid, or an anhydride or half ester thereof. ..

Further, other copolymerizable monomers can be acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, vinyl acetate, alkyl vinyl ether and the like.

On the other hand, examples of the monomer containing a hydroxyl group that constitutes a polymer containing a hydroxyl group include, for example, maleic anhydride, diacrylic acid anhydride, dimethacrylic acid anhydride, and the like. , Styrene/maleic anhydride copolymer, olefin (eg, isobutylene, butadiene)/maleic anhydride copolymer, vinyl acetate/maleic anhydride copolymer, acrylic ester/maleic anhydride copolymer, methacrylic ester /Maleic anhydride-based copolymers such as maleic anhydride copolymers and methyl vinyl ether/maleic anhydride copolymers; diacrylic anhydride-based copolymers such as diacrylic anhydride/styrene copolymers; dimethacrylic acid Dimethacrylic acid anhydride-based copolymers such as anhydride/styrene copolymers; Among these, maleic anhydride-based copolymers are preferable because they have high reactivity with polyvinyl alcohol.

The molecular weight of the polymer containing a carboxyl group or a non-hydroxyl group is not particularly limited, but is preferably 3,000 to 5,000,000, more preferably 40 to 4,000,000, and 5,000 to 3,000,000. It is more preferable.

Two or more kinds of polymers containing a carboxyl group or a non-hydroxyl group may be bonded to the second polymer in the PVA-based coated fiber.

The second polymer in the PVA-based fiber of the present invention has polyvinyl alcohol bonded to a polymer containing a carboxyl group or a non-hydroxyl group, but the polyvinyl alcohol and the carboxyl group or The mass ratio with the polymer containing a non-hydroxyl group is preferably 1 to 99:99 to 1, more preferably 20 to 95:80 to 5, and further preferably 40 to 90:60 to 10. ..

The second polymer in the PVA-based coated fiber of the present invention is obtained by combining the above-mentioned polyvinyl alcohol and a polymer containing a carboxyl group or a non-hydroxyl group with an amine or quaternary ammonium having an alkyl group having 6 or more carbon atoms. Therefore, the PVA-based coated fiber is excellent in hydrophobicity. That is, the hydroxyl group of polyvinyl alcohol is ester-bonded with a polymer containing a carboxyl group or a non-hydroxyl group, and the amine or quaternary ammonium having an alkyl group having 6 or more carbon atoms is a hydroxyl group of polyvinyl alcohol or a carboxyl group. Alternatively, it is considered that the PVA-based coated fiber is excellent in hydrophobicity due to the amide bond with the polymer containing a non-hydroxyl group.

This amine or quaternary ammonium has an alkyl group having 6 or more carbon atoms, and the second polymer has strong hydrophobicity. However, the higher the carbon number, the stronger the hydrophobicity of the PVA-based coated fiber. The alkyl group preferably has 8 or more carbon atoms, more preferably 10 or more carbon atoms, further preferably 11 or more carbon atoms, and further preferably 12 or more carbon atoms. The upper limit of the carbon number of the alkyl group is not particularly limited, but is preferably 24 or less, more preferably 20 or less, and further preferably 18 or less.

The alkyl group constituting the amine or quaternary ammonium of the present invention may be linear or branched as long as it has 6 or more carbon atoms.

Specific examples of the amine include hexylamine, heptylamine, octynylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine. Primary amines such as amines, nonadecylamine, icosylamine, henicosylamine, docosylamine, tricosylamine, tetracosylamine, octadecenylamine, octadecadienylamine; dihexylamine, diheptylamine, dioctynylamine, dinonylamine, didecylamine. , Diundecylamine, didodecylamine, ditridecylamine, ditetradecylamine, dipentadecylamine, dihexadecylamine, diheptadecylamine, dioctadecylamine, dinonadecylamine, diicosylamine, dihenicosylamine, Secondary amines such as didocosylamine, ditricosylamine, ditetracosylamine, dioctadecenylamine, dioctadecadienylamine; trihexylamine, triheptylamine, trioctynylamine, trinonylamine, tridecylamine, Triundecylamine, tridodecylamine, tritridecylamine, tritetradecylamine, tripentadecylamine, trihexadecylamine, triheptadecylamine, trioctadecylamine, trinonadecylamine, triicosylamine, trihenicosylamine And tertiary amines such as ruamine, tridocosylamine, tritricosylamine, tritetracosylamine, trioctadecenylamine, trioctadecadienylamine; These amines may be one kind or a mixture of these amines derived from animal and vegetable oils such as beef tallow amine, hydrogenated tallow amine, coconut oil amine, palm oil amine and soybean oil amine. Among these, hexylamine or dodecylamine, which are excellent in reactivity, are preferable.

Examples of the quaternary ammonium include dodecyl trimethyl ammonium, hexyl trimethyl ammonium, heptyl trimethyl ammonium, octynyl trimethyl ammonium, nonyl trimethyl ammonium, decyl trimethyl ammonium, undecyl trimethyl ammonium, dodecyl trimethyl ammonium, tridecyl trimethyl ammonium, tetra Decyltrimethylammonium, pentadecyltrimethylammonium, hexadecyltrimethylammonium, heptadecyltrimethylammonium, octadecyltrimethylammonium, nonadecyltrimethylammonium, icosyltrimethylammonium, henicosyltrimethylammonium, docosyltrimethylammonium, tricosyltrimethylammonium, tetra Cosyl trimethyl ammonium, octadecenyl trimethyl ammonium, octadecadienyl trimethyl ammonium, etc. can be mentioned.

As described above, the second polymer constituting the PVA-based coated fiber of the present invention is polyvinyl alcohol, a polymer containing a carboxyl group or a non-hydroxyl group, and a polymer to which an amine or a quaternary ammonium is bonded, but the organic solvent resistance and The amount of amine or quaternary ammonium is 0.1 to 100 parts by mass relative to 100 parts by mass of polyvinyl alcohol and a polymer containing a carboxyl group or a non-hydroxyl group so as to have excellent hydrophobicity. Is preferable, the mass ratio of 0.3 to 50 parts is more preferable, and the mass ratio of 0.5 to 10 parts is more preferable.

The PVA-based coated fiber of the present invention is in a state in which the first polymer is coated with the second polymer as described above, but the first polymer is the second polymer so that it has excellent organic solvent resistance and hydrophobicity. It is preferably completely covered. However, if even a part of the surface of the first polymer is covered with the second polymer, it has excellent organic solvent resistance and hydrophobicity. Therefore, 50% or more of the surface area of the first polymer may be covered with the second polymer. Good.

The average fiber diameter of the PVA-based coated fiber of the present invention is not particularly limited, but can be 1 nm to 10,000 nm. In order to effectively utilize the surface of the PVA-based fiber, it is preferably 2,000 nm or less, more preferably 1,000 nm or less, further preferably 800 nm or less, and 600 nm or less. More preferably, it is 400 nm or less, still more preferably 300 nm or less. On the other hand, the lower limit of the average fiber diameter is not particularly limited, but it is preferably 1 nm or more, and more preferably 20 nm or more so as to have excellent strength and handleability. The "fiber diameter" in the present invention means the diameter of the fiber obtained by measuring from the electron micrograph on the plane of the fiber assembly, and the "average fiber diameter" means the arithmetic mean value of the fiber diameters at 50 locations.

The fiber assembly of the present invention contains such a PVA-based coated fiber, but preferably contains 50% by mass or more of the PVA-based coated fiber so as to have excellent organic solvent resistance and waterproofness, and 70 mass%. It is more preferably contained in the above amount, more preferably 90% by mass or more, and most preferably 100% by mass of PVA-based coated fiber.

The fibers other than the PVA-based coated fiber that can form the fiber assembly of the present invention are not particularly limited as long as they do not impair the organic solvent resistance and waterproofness of the fiber assembly, and include, for example, fluorine-based fibers. Resin fiber, polyolefin resin fiber, polyester resin fiber, polysulfone resin fiber (polysulfone, polyether sulfone, etc.), styrene resin fiber, polyether resin fiber (polyether ether ketone, polyacetal, modified polyphenylene ether, aromatic) (Polyetherketone etc.), polyamideimide resin fiber, polyimide resin fiber, urethane resin fiber, polyacrylonitrile resin fiber, polybenzimidazole resin fiber and the like.

The fiber assembly of the present invention contains the PVA-based coated fiber as described above, but the assembled state is not particularly limited. For example, it may be in a regularly gathered state such as a woven fabric or a knitted fabric, or may be in a randomly gathered state like a non-woven fabric. In particular, a non-woven fabric is preferable because it can be a fiber aggregate having uniform pore diameters.

Since the fiber assembly of the present invention is excellent in organic solvent resistance, it can be applied to applications requiring organic solvent resistance. Specifically, it is preferable that the organic solvent resistance is 5% or less after immersing in N,N-dimethylformamide for 10 minutes. The smaller the dimensional change rate, the better the organic solvent resistance. Therefore, the dimensional change rate is more preferably 3% or less, further preferably 1% or less.

（５）前記（１）〜（４）の操作を繰り返し、５枚の試料について寸法変化率を算出し、その寸法変化率の算術平均値を、繊維集合体の「寸法変化率」とする。 The dimensional change rate, which is an index of the organic solvent resistance, is a value obtained by the following operation.
(1) A 5 cm square sample is collected from the fiber assembly.
(2) The sample is immersed in a N,N-dimethylformamide solution maintained at a temperature of 25° C. for 10 minutes.
(3) After 10 minutes, after pulling up the sample from the solution, the lengths (L ₁ , L ₂ , L ₃ , L ₄ ) of the four sides of the sample are measured.
(4) The dimensional change rate (Rd, unit: %) is calculated by the following formula from the length of the four sides of the sample after immersion.

(5) The operations (1) to (4) are repeated to calculate the dimensional change rate for five samples, and the arithmetic average value of the dimensional change rate is defined as the “dimensional change rate” of the fiber assembly.

Further, since the fiber assembly of the present invention has excellent waterproofness, it can be applied to applications requiring waterproofness. Specifically, it is preferable to have waterproofness with a mass increase rate of 100% or less after being immersed in water. The smaller the mass increase rate, the better the waterproof property. Therefore, the mass increase rate is preferably 80% or less, more preferably 60% or less, and 40% or less. Is more preferable.

The mass increase rate, which is an index of the waterproof property, is a value obtained by the following operation.
(1) After collecting a 5 cm square sample from the fiber assembly, the mass (Mb) of the sample is measured.
(2) The sample is immersed in water having a temperature of 25° C. for 10 minutes.
(3) After 10 minutes, the sample is pulled out from water and dehydrated with a pair of rollers (linear pressure: 0.86 N/cm), and then the mass (Ma) of the sample is measured.
(4) The mass increase rate (Mi) is calculated from the mass of the sample before and after the immersion by the following formula.
Mi=[(Ma-Mb)/Mb]×100
(5) The operations (1) to (4) are repeated to calculate the mass increase rate for five samples, and the arithmetic average value of the mass increase rates is defined as the “mass increase rate” of the fiber assembly.

The unit weight of the fiber assembly of the present invention (value measured according to JIS L1085 as 10 cm×10 cm) is not particularly limited, but is preferably 0.1 to 500 g/m ² , and 0.5 to 100 g. more preferably from / ^{m 2,} more preferably in the range of 1 to 50 g / ^{m 2,} and even more preferably 2 to 30 g / ^{m 2.} The thickness of the fiber assembly is a value measured by using an outer micrometer under a load of 5 N, preferably 1 to 2000 μm, more preferably 3 to 400 μm, and 5 to 150 μm. Is more preferable.

Since such a fiber assembly of the present invention is excellent in organic solvent resistance and waterproofness, it can be suitably used for applications requiring organic solvent resistance and waterproofness. For example, adhesive medicated substrates, clothing materials (interlining, padding, etc.), surgical materials (surgical coverings, surgical clothes, etc.), moisture-permeable waterproof sheets, filter media (for gases, liquids) Etc.), an agricultural material sheet, a building material sheet, a diaper cover, a food packaging material, a membrane support, a separator of an electrochemical device such as an electric double layer capacitor.

The fiber assembly of the present invention can be manufactured, for example, as follows.

First, a first polymer soluble or hydrophilic in an organic solvent is prepared. The first polymer can be the first polymer as described above. Further, a solvent capable of dissolving the first polymer is prepared. This solvent is not particularly limited, but for example, if it is the first polymer soluble in the former organic solvent, it may be the above-mentioned organic solvent, and it may be the latter hydrophilic first polymer. For example, it can be water, alcohols, and other organic solvents (amides such as dimethylformamide and dimethylacetamide). This solvent may be composed of one type of solvent, or may be a mixed solvent of these solvents.

Then, a spinning solution in which the first polymer is dissolved is prepared. The solid content concentration of this spinning solution is not particularly limited as long as it can dissolve the first polymer, but the viscosity is 100 to 100,000 mPa·s so that stable spinning can be performed. It is preferably a concentration. The method for preparing the spinning solution in which the first polymer is dissolved is not particularly limited. In addition, the “viscosity” in the present invention means a value at a shear rate of 100 s ⁻¹ measured at a temperature at the time of application (for example, during spinning, during coating, etc.) using a viscosity measuring device (made by Thermo Electron).

The spinning solution may contain various functional substances. For example, it may contain a flame retardant, a conductive agent, an adsorbent, a wet strong paper agent, a sizing agent, a swelling agent, a coloring agent, a water repellent, a pressure sensitive adhesive, an adhesive, a medicinal component and the like.

Then, the spinning solution is spun to form a precursor fiber made of the first polymer. The spinning method of the precursor fiber may be a conventionally known spinning method, for example, a wet spinning method, a dry spinning method, a flash spinning method, a centrifugal spinning method, an electrostatic spinning method, and a disclosure in JP 2009-287138 A. As described above, a method of spinning by a shearing action of gas, or a method of spinning by applying a shearing force of gas in addition to the action of an electric field, as disclosed in JP 2011-32593 A, etc. Can be mentioned. Among these, the electrostatic spinning method is preferable because the average fiber diameter is small (average fiber diameter is 2000 nm or less), the fiber diameter is uniform, and continuous precursor fibers can be spun.

Next, a precursor fiber aggregate including the spun precursor fibers is formed. The method of forming this precursor fiber aggregate is not particularly limited, but the precursor fibers spun by the above-described method can be directly accumulated on a support such as a drum or a conveyor to form a precursor fiber aggregate. .. Alternatively, the spun precursor fiber may be cut into short fibers, and then the precursor fiber aggregate may be formed by a wet method or a dry method such as a card machine or an air lay. When the average fiber diameter of the precursor fibers is small (average fiber diameter is 2000 nm or less), it tends to be difficult to form the precursor fiber aggregate after forming the short fibers, and the precursor fiber aggregate Since the formation becomes complicated, it is preferable to directly accumulate the spun precursor fibers on a support to form a precursor fiber aggregate.

On the other hand, polyvinyl alcohol, a polymer containing a carboxyl group or a non-hydroxyl group, and an amine or quaternary ammonium having an alkyl group having 6 or more carbon atoms are prepared. As described above, as the polyvinyl alcohol, unmodified polyvinyl alcohol (polyvinyl alcohol saponified at 100 mol%, partially saponified polyvinyl alcohol, or reacetic acid product) is preferable. Further, as the polymer containing a carboxyl group or a non-hydroxyl group, highly reactive with polyvinyl alcohol, maleic anhydride copolymer, polyacrylic acid is preferable, and as an amine, it has excellent reactivity and is soluble in a solvent. It is preferable to prepare hexylamine or dodecylamine, which has excellent properties, and dodecyltrimethylammonium as the quaternary ammonium.

The amine or quaternary ammonium may be prepared in the form of salt. For example, it may be a hydrochloride, acetate, hydrobromide, sulfate, hydrogenate, nitrate, oxalate or the like. Such a salt form is preferable because it is easily dissolved in water.

Further, a solvent capable of dissolving either polyvinyl alcohol, a polymer containing a carboxyl group or a non-hydroxyl group, and an amine or a quaternary ammonium is prepared. This solvent is not particularly limited, but for example, water, alcohols, and other organic solvents (amides such as dimethylformamide and dimethylacetamide) can be used. This solvent may be composed of one type of solvent, or may be a mixed solvent of these solvents.

Next, a solution in which polyvinyl alcohol, a polymer containing a carboxyl group or a non-hydroxyl group, and an amine or a quaternary ammonium are dissolved (hereinafter sometimes referred to as a "coating solution") is prepared. The method for preparing the coating liquid is not particularly limited.

In addition, when preparing a coating liquid, it is preferable to mix it so that the mass ratio of polyvinyl alcohol and the polymer containing a carboxyl group or a non-hydroxyl group may be 1 to 99:99 to 1, as described above. It is more preferable to mix it so as to be 80 to 5, and it is more preferable to mix it so as to be 40 to 90:60 to 10.

Further, the amount of amine or quaternary ammonium is blended so as to be a mass ratio of 0.1 to 100 parts with respect to a total mass of 100 parts of polyvinyl alcohol and a polymer containing a carboxyl group or a non-hydroxyl group. It is more preferable to mix it in a mass ratio of 0.3 to 50 parts, and it is more preferable to mix it in a mass ratio of 0.5 to 10 parts.

Furthermore, if the viscosity of the coating liquid is high, the film of the second polymer is likely to be formed, and the porosity of the fiber assembly is likely to be impaired. Since it tends to be difficult to sufficiently coat the precursor fiber, the viscosity of the coating liquid is preferably 1 to 500 mPa·s, and more preferably 1 to 100 mPa·s.

Incidentally, the coating liquid is polyvinyl alcohol, a polymer containing a carboxyl group or a non-hydroxyl group, and other than amines or quaternary ammonium, various functional substances within a range not impairing the organic solvent resistance and waterproofness of the fiber assembly. Can be included. For example, a flame retardant, a conductive agent, an adsorbent, a wet strong paper agent, a sizing agent, a swelling agent, a coloring agent, a water repellent, a pressure sensitive adhesive, an adhesive, a medicinal component and the like can be included.

Next, the precursor liquid constituting the precursor fiber aggregate is coated with the coating liquid to form a coated precursor fiber aggregate. The method of coating the precursor fiber with this coating solution is not particularly limited, but for example, a method of immersing the precursor fiber assembly in the coating solution, a method of applying the coating solution to the precursor fiber assembly, and a precursor of the coating solution The method of spraying on a fiber aggregate can be mentioned. Among these, the method of immersing the precursor fiber aggregate in the coating liquid is preferable because the entire precursor fiber surface can be coated with the coating liquid, and it is easy to produce a fiber aggregate having excellent organic solvent resistance and water resistance. ..

Next, polyvinyl alcohol constituting the coating liquid, a polymer containing a carboxyl group or a non-hydroxyl group, and an amine or a quaternary ammonium are bonded to form a PVA-based coated fiber, and the fiber assembly of the present invention can be manufactured. For example, by heat treatment, microwave irradiation, ultraviolet irradiation, plasma irradiation, near infrared irradiation, far infrared irradiation, electron beam (radiation etc.) irradiation, polyvinyl alcohol, a polymer containing a carboxyl group or a non-hydroxyl group, and an amine or A fiber assembly can be produced by binding quaternary ammonium to form a PVA-based coated fiber.

In particular, it is preferable to perform heat treatment at 130 to 230° C., since removal of the solvent of the coating liquid and reaction can proceed simultaneously. When the temperature is lower than 130° C., an ester bond between a hydroxyl group of polyvinyl alcohol and a carboxyl group of a polymer containing a carboxyl group or a non-hydroxyl group, and/or a carboxyl group of a polymer containing a carboxyl group or a non-hydroxyl group and an amine or quaternary Since it is considered that the imide bond with ammonium does not proceed sufficiently, the temperature is preferably 140° C. or higher, more preferably 150° C. or higher. On the other hand, when the temperature exceeds 230° C., the PVA-based coated fibers are colored, the PVA-based coated fibers are partially fused with each other, and the fiber aggregate is largely shrunk to stably produce the fiber aggregate. Since it tends to be impossible, it is more preferable that the temperature is 190° C. or lower. The above temperature is the temperature on the surface of the coated precursor fiber assembly, and the temperature of the heat source may be 230°C or higher.

Further, when the PVA-based coated fiber is bonded by heat treatment, the time is a time when the bonding of polyvinyl alcohol, a polymer containing a carboxyl group or a non-hydroxyl group, and an amine or a quaternary ammonium proceeds sufficiently. Although it is not particularly limited, it is preferably 1 minute or longer, more preferably 5 minutes or longer, still more preferably 10 minutes or longer. On the other hand, the binding does not proceed even if it is heated for a too long time, so that it is preferably within 1 hour, more preferably within 45 minutes.

If necessary, various post-treatments can be performed so that the fiber assembly is suitable for various uses. For example, calendar processing or the like can be performed.

After forming the precursor fiber aggregate, the above is coated with a coating liquid containing polyvinyl alcohol, a polymer containing a carboxyl group or a non-hydroxyl group, and an amine having an alkyl group having 6 or more carbon atoms or a quaternary ammonium, and bonded. A method for producing a fiber assembly is also possible, in which a PVA-based coated fiber in which a first polymer is coated with a second polymer is formed and then cut into short fibers, and the fiber assembly is formed by a wet method or a dry method. it can.

The PVA-based coated fiber includes, for example, the spinning solution A in which the first polymer is dissolved, polyvinyl alcohol, a polymer containing a carboxyl group or a non-hydroxyl group, and an amine or quaternary ammonium having an alkyl group having 6 or more carbon atoms. A method in which the spinning solution B containing the same is mixed or spun, and the constituent components of the spinning solution B are combined, and the precursor fiber formed by spinning the spinning solution A in which the first polymer is dissolved is coated with the coating solution and then the coating solution. It can be formed by a method of combining constituent components.

When fibers other than PVA-based coated fibers are mixed in forming a fiber assembly by a wet method or a dry method using such short fibers of PVA-based coated fibers, fibers other than PVA-based coated fibers are included. Fiber aggregates can be formed.

Examples of the present invention will be described below, but the present invention is not limited to the following examples. The physical properties of the fiber assembly were evaluated by the following methods.

(Organic solvent resistance)
The dimensional change rate was calculated by the method described above.

(Waterproof)
The mass increase rate was measured by the method described above. When the mass increase rate was 100% or less, the waterproof property was evaluated as excellent.

(Example 1)
Polyacrylonitrile [manufactured by Aldrich] was dissolved in N,N-dimethylformamide to prepare a spinning solution having a concentration of 17 mass%.

Then, using an electrostatic spinning device having a nozzle and a drum as a pair of electrodes, the precursor continuous fibers are electrostatically spun under the following conditions, and then directly accumulated on the drum to obtain a precursor continuous fiber aggregate (weight per unit area). : 3.2 g/m ² , thickness: 20 μm, average fiber diameter: 300 nm).

Nozzle inner diameter: 0.44 mm
Nozzle-drum distance: 10 cm
Amount discharged from nozzle: 1 cm ³ /hour Applied voltage: 15-25 kV
Spinning environment temperature: 25°C
Environmental humidity of spinning: 40%RH

On the other hand, partially saponified polyvinyl alcohol [average degree of polymerization: 140, degree of saponification: 80 mol%] and a methyl vinyl ether/maleic anhydride copolymer (1 mol of methyl vinyl ether: 1 mol of maleic anhydride, molecular weight: 220,000). , ALDRICH) in a mass ratio of 1/1, and then 5 parts of dodecylamine hydrochloride to 100 parts of the total solid content of partially saponified polyvinyl alcohol and methyl vinyl ether/maleic anhydride copolymer. A coating aqueous solution (concentration: 1 mass%, viscosity: 1 mPa·s) was prepared by adding.

Next, the precursor continuous fiber aggregate is immersed in a coating aqueous solution, and the surface of the precursor continuous fiber is coated with the coating aqueous solution, and then heat treatment is performed at a temperature of 180° C. for 30 minutes to obtain polyvinyl alcohol, methyl vinyl ether/maleic anhydride. The copolymer and dodecylamine were combined to prepare a non-woven fabric fiber assembly consisting of 100% PVA-based continuous coated fibers. The physical properties of the fiber assembly were as shown in Table 1.

(Comparative Example 1)
Partially saponified polyvinyl alcohol [average degree of polymerization: 140, degree of saponification: 80 mol%] and a methyl vinyl ether/maleic anhydride copolymer are mixed at a mass ratio of 1/1 to prepare a coating aqueous solution (dodecylamine is not included). , Viscosity: 1 mPa·s) was prepared, and a non-woven fabric fiber aggregate consisting of 100% PVA-based continuous coated fiber was prepared in the same manner as in Example 1 except that the surface of the precursor continuous fiber was coated with this coating aqueous solution. It was made. The physical properties of the fiber assembly were as shown in Table 1.

(Comparative example 2)
The precursor continuous fiber assembly of Example 1 was used as a comparative fiber assembly. The physical properties of this fiber assembly were as shown in Table 1.

(Examples 2 to 6, Comparative Examples 3 to 4)
Polyethersulfone [Sumika Excel 5200P] was dissolved in a mixed solvent of N,N-dimethylacetamide/methylethylketone (mass ratio: 3/1) to prepare a spinning solution having a concentration of 20 mass %.

Then, using an electrostatic spinning device having a nozzle and a drum as a pair of electrodes, the precursor continuous fibers are electrostatically spun under the following conditions, and then directly accumulated on the drum to obtain a precursor continuous fiber aggregate (weight per unit area). : 5.2 g/m ² , thickness: 30 μm, average fiber diameter: 300 nm).

Nozzle inner diameter: 0.44 mm
Nozzle-drum distance: 10 cm
Amount discharged from nozzle: 1 cm ³ /hour Applied voltage: 15-25 kV
Spinning environment temperature: 25°C
Environmental humidity of spinning: 40%RH

On the other hand, completely saponified polyvinyl alcohol [average degree of polymerization: 1000] and methyl vinyl ether/maleic anhydride copolymer (1 mol of methyl vinyl ether: 1 mol of maleic anhydride, molecular weight: 220,000, manufactured by ALDRICH) After mixing in a mass ratio of 1, hexylamine acetate (5 parts) (Example 2), dodecylamine hydrochloride was added to 100 parts of the total solid content of the completely saponified polyvinyl alcohol and the methyl vinyl ether/maleic anhydride copolymer. Add 5 parts of salt (Example 3), 5 parts of dodecylamine acetate (Example 4), 5 parts of dodecyltrimethylammonium hydrochloride (Example 5), 1 part of octadecylamine hydrochloride (Example 6), A coating solution [concentration: 1 mass%, water/ethanol=9/1 (wt/wt)] was prepared. Further, a coating solution was prepared without adding an ammonium salt (Comparative Example 3).

Then, the precursor continuous fiber aggregate is dipped in a coating solution to coat the surface of the precursor continuous fiber with the coating solution, and then heat treatment is performed at a temperature of 180° C. for 30 minutes to obtain polyvinyl alcohol, methyl vinyl ether/maleic anhydride. The copolymer and the amine or the quaternary ammonium were bonded to each other to prepare a non-woven fabric fiber assembly composed of 100% PVA-based continuous coated fiber. The precursor continuous fiber assembly was used as a comparative fiber assembly (Comparative Example 4, no coating with coating solution). The physical properties of these fiber aggregates are as shown in Table 2.

(Example 7, Comparative Example 5)
Fully saponified polyvinyl alcohol [average degree of polymerization: 1000] and methyl vinyl ether/maleic anhydride copolymer (1 mol of methyl vinyl ether: 1 mol of maleic anhydride, molecular weight: 220,000, manufactured by ALDRICH) at a mass of 4/1 The mixture was mixed in a ratio to prepare a spinning aqueous solution having a concentration of 15 mass %.

Then, using an electrostatic spinning device having a nozzle and a drum as a pair of electrodes, the precursor continuous fibers are electrostatically spun under the following conditions, and then directly accumulated on the drum to obtain a precursor continuous fiber aggregate (weight per unit area). : 4.7 g/m ² , thickness: 19 μm, average fiber diameter: 300 nm).

Nozzle inner diameter: 0.44 mm
Nozzle-drum distance: 10 cm
Amount discharged from nozzle: 1 cm ³ /hour Applied voltage: 15-25 kV
Spinning environment temperature: 25°C
Environmental humidity of spinning: 40%RH

On the other hand, completely saponified polyvinyl alcohol [average degree of polymerization: 1000] and a methyl vinyl ether/maleic anhydride copolymer (1 mol of methyl vinyl ether: 1 mol of maleic anhydride, molecular weight: 220,000, manufactured by ALDRICH) After mixing in a mass ratio of 1, 1 part of dodecylamine hydrochloride was added to 100 parts of the total solid content of the completely saponified polyvinyl alcohol and the methyl vinyl ether/maleic anhydride copolymer, and the coating solution [concentration: 1 mass%] was prepared.

Next, the precursor continuous fiber aggregate is immersed in a coating aqueous solution, and the surface of the precursor continuous fiber is coated with the coating aqueous solution, and then heat treatment is performed at a temperature of 180° C. for 30 minutes to obtain polyvinyl alcohol, methyl vinyl ether/maleic anhydride. The copolymer and dodecylamine were combined to prepare a non-woven fabric fiber assembly consisting of 100% PVA-based continuous coated fibers. The precursor continuous fiber assembly was used as a comparative fiber assembly (Comparative Example 5, no coating with coating solution). The physical properties of these fiber aggregates are as shown in Table 3.

(Example 8, Comparative Example 6)
Rayon fiber (fiber diameter: 3.3 dtex, fiber length 51 mm), polypropylene fiber (fiber diameter: 2.2 dtex, fiber length: 50 mm) and polypropylene/polyethylene core-sheath composite fiber (fiber diameter: 1.7 dtex, fiber length: 51 mm) in a mass ratio of 80/15/5 to form a fiber web, which is then entangled by a hydroentangling method to form a precursor fiber aggregate in a non-woven fabric form (weight: 60 g/m ² , thickness: 340 μm). , Average fiber diameter: 15 μm) was formed.

On the other hand, completely saponified polyvinyl alcohol [average degree of polymerization: 1000] and a methyl vinyl ether/maleic anhydride copolymer (1 mol of methyl vinyl ether: 1 mol of maleic anhydride, molecular weight: 220,000, manufactured by ALDRICH) After mixing in a mass ratio of 1, 1 part of dodecylamine hydrochloride was added to 100 parts of the total solid content of the completely saponified polyvinyl alcohol and the methyl vinyl ether/maleic anhydride copolymer, and the coating solution [concentration: 0.5 mass%] was prepared.

Then, the precursor fiber aggregate is dipped in a coating aqueous solution, the precursor fiber surface is coated with the coating aqueous solution, and then heat treatment is carried out at a temperature of 150° C. for 30 minutes to obtain polyvinyl alcohol, methyl vinyl ether/maleic anhydride copolymer The union and the dodecylamine were combined to produce a non-woven fabric fiber assembly consisting of 100% PVA-based coated fibers. The precursor fiber assembly was used as a fiber assembly for comparison (Comparative Example 6, no coating with coating solution). The physical properties of these fiber aggregates are shown in Table 4.

From the results of Tables 1 to 4, the second polymer is polyvinyl alcohol, a polymer containing a carboxyl group or a non-hydroxyl group, and an amine having a C6 or more alkyl group or a quaternary ammonium-bonded polymer, It was found that the fiber assembly was excellent in organic solvent property and waterproof property.

Since the fiber assembly of the present invention is excellent in organic solvent resistance and waterproofness, it can be suitably used for applications requiring organic solvent resistance and waterproofness. For example, adhesive medicated substrates, clothing materials (interlining, padding, etc.), surgical materials (surgical coverings, surgical clothes, etc.), moisture-permeable waterproof sheets, filter media (for gases, liquids) Etc.), agricultural material sheet, building material sheet, diaper cover, food packaging material, membrane support, separator of electrochemical element such as electric double layer capacitor.

Claims (2)

An organic solvent-soluble or hydrophilic first polymer is a fiber assembly including fibers coated with a second polymer, and the second polymer is polyvinyl alcohol, a polymer containing a carboxyl group or a non-hydroxyl group, and carbon. A fiber assembly, which is a polymer to which an amine having an alkyl group of 6 or more or a quaternary ammonium is bonded. A step of forming a precursor fiber assembly including a precursor fiber composed of a first polymer soluble or hydrophilic in an organic solvent,
Coating the precursor fiber assembly with a solution containing polyvinyl alcohol, a polymer containing a carboxyl group or a non-hydroxyl group, and an amine having an alkyl group having 6 or more carbon atoms or a quaternary ammonium;
Binding polyvinyl alcohol, a polymer containing a carboxyl group or a non-hydroxyl group, and an amine or a quaternary ammonium having an alkyl group having 6 or more carbon atoms in the solution,
A method for producing a fiber assembly, comprising: