JP2009074229A - Sizing agent for fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sizing agent for fiber, which hardly causes napping, and is excellent in molded product strength when applied to a fiber-reinforced resin. <P>SOLUTION: The sizing agent for fiber is applied to carbon fiber or aramid fiber for fiber-reinforced resin and contains a vinyl polymer (A) comprising 10 mol% or more of one or more monomer (a) selected from the group consisting of an ammonium salt of an anionic monomer, a nitrogen atom-containing cationic monomer, and a salt of the nitrogen atom-containing cationic monomer, and 90 mol% or less of other monomers (b), wherein the vinyl polymer (A) has contact angle of 55° or less between a film obtained by drying the vinyl polymer (A) and an ethanol/water mixture liquid of a weight ratio of 10/90. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fiber sizing agent used for carbon fiber or aramid fiber for fiber reinforced resin.

Carbon fiber, aramid fiber, glass fiber, or the like is used as the fiber for fiber reinforced resin. Conventionally, polyester-based polymers, polyurethane-based polymers, and the like have been used as sizing agents used in these fiber sizing processes. These conventional sizing agents were suitable for glass fibers, but because the coating was relatively hard and brittle, when used on thin and soft carbon fibers or aramid fibers, the coating was damaged by abrasion during the sizing process. There was a problem that a lot of fluff was generated due to damage. As a sizing agent for carbon fibers, there is an example in which a water-soluble vinyl polymer is used as a sizing agent used for carbon fibers for papermaking or concrete reinforcement (Patent Document 1). However, these water-soluble vinyl polymers have a problem that voids are easily formed during the molding of the fiber reinforced resin, and the strength of the molded product is not sufficient.
Patent 3592936

  An object of the present invention is to provide a fiber sizing agent that is difficult to fluff and has a sufficient strength of a molded product when used in a fiber reinforced resin.

  As a result of intensive studies to solve the above-mentioned problems, the inventors of the present application are responsible for the generation of voids at the time of molding because the water-soluble vinyl polymer is a salt such as an alkali metal salt. It was found that voids are likely to occur, resulting in insufficient strength of the molded product. In addition, it was found that the wettability of the water-soluble vinyl polymer dry film and the matrix resin greatly affects the strength of the molded product, and the contact angle between the dry film of the polymer and the ethanol / water mixture as an indicator of wettability. It has been found that excellent molded product strength can be obtained by limiting to a certain range. That is, the present invention is a fiber sizing agent used for carbon fiber or aramid fiber for fiber reinforced resin, an ammonium salt of an anionic monomer, a nitrogen atom-containing cationic monomer and a salt of a nitrogen atom-containing cationic monomer Containing at least one monomer (a) selected from the group consisting of 10 mol% or more, and another monomer (b) containing 90 mol% or less of a vinyl polymer (A), A fiber sizing agent, characterized in that it is a vinyl polymer having a contact angle between a film obtained by drying (A) and a 10/90 weight ratio ethanol / water mixed solution of 55 ° or less.

  The fiber sizing agent of the present invention is less prone to fluff during the sizing process, its film has an appropriate strength and polarity, and is not hygroscopic. And exhibits good molded product strength because it does not generate voids.

  In the present invention, the vinyl polymer (A) is selected from the group consisting of an anionic monomer ammonium salt (a1), a nitrogen atom-containing cationic monomer (a2), and a nitrogen atom-containing cationic monomer salt (a3). One or more kinds of monomers (a) all contain a nitrogen atom in the molecule and are ionic, so that they have an appropriate polarity. Moreover, since (a) has comparatively little hygroscopicity, the fiber sizing agent containing a vinyl polymer composed of a monomer containing these monomers is less likely to generate voids.

The following (a11)-(a13) are mentioned as an anionic monomer which comprises the ammonium salt (a1) of an anionic monomer among (a).
(A11) a carboxyl group-containing monomer;
Unsaturated monocarboxylic acid [(meth) acrylic acid etc.] and unsaturated dicarboxylic acid [maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, crotonic acid etc.] are mentioned. In the present invention, (meth) acryl ... means acrylic ... and methacryl ...

(A12) a sulfonic acid group-containing vinyl monomer;
C2-C6 alkene sulfonic acid [vinyl sulfonic acid and (meth) allyl sulfonic acid etc.], C6-C12 vinyl group-containing aromatic sulfonic acid [alpha-methylstyrene sulfonic acid etc.], sulfonic acid group-containing (Meth) acrylic ester monomers [2- (meth) acryloyloxyethanesulfonic acid, etc.], sulfonic acid group-containing (meth) acrylamide monomers [2- (meth) acrylamide-2-methylpropanesulfonic acid, etc.], sulfonic acid Vinyl monomer containing a group and a hydroxyl group [3- (meth) acrylamide-2-hydroxypropanesulfonic acid, 3-allyloxy-2-hydroxypropanesulfonic acid, 3- (meth) acryloyloxy-2-hydroxypropanesulfonic acid, etc.] , Alkyl (C3-C18) allylsulfosuccinate [ Decyl allyl sulfosuccinate], and the like.

(A13) phosphate ester group-containing vinyl monomer;
Monoalkenyl phosphate (2 to 12 carbon atoms) [vinyl phosphate, allyl phosphate, propenyl phosphate and isopropenyl phosphate, etc.], (meth) acryloyloxyalkyl (1 to 12 carbon atoms) phosphate ester [ (Meth) acryloyloxyethyl phosphate and (meth) acryloyloxyisopropyl phosphate] and the like.

  Preferred among (a1) is (a11), and more preferred are (meth) acrylic acid, maleic acid, fumaric acid, and combinations thereof. Since (a1) is an ammonium salt, it has low hygroscopicity and less voids. Alkali metal salts and organic amine salts have high hygroscopicity, and the strength of the molded product is insufficient.

  The vinyl polymer (A) having the monomer (a1) as a constituent monomer may polymerize the ammonium salt of the above anionic monomer, but from the viewpoint of handling the monomer, after the anionic monomer is polymerized, ammonia is added. It is preferable to neutralize to an ammonium salt.

Among (a), the nitrogen atom-containing cationic monomer (a2) includes the following (a21) to (a23).
(A21) Primary or secondary amino group-containing monomer:
Aminoalkyl (1 to 8 carbon atoms) (meth) acrylate and (meth) acrylamide [aminoethyl (meth) acrylate, aminopropyl (meth) acrylate, N-aminoethyl (meth) acrylamide, etc.] and their monoalkyl (carbon) Formula 1-6) Substituents [monomethylaminoethyl (meth) acrylate, monoethylaminoethyl (meth) acrylate, t-butylaminoethyl methacrylate, etc.], mono (meth) allylamine and the like can be mentioned.

(A22) Tertiary amino group-containing monomer:
Dialkyl (1 to 4 carbon atoms) aminoalkyl (1 to 8 carbon atoms) (meth) acrylate and (meth) acrylamide [dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, etc. And morpholinoethyl (meth) acrylate and the like.

(A23) Quaternary ammonium group-containing monomer:
Trialkyl (1 to 4 carbon atoms) ammonium alkyl (1 to 8 carbon atoms) (meth) acrylate and (meth) acrylamide [trimethylammoniumethyl (meth) acrylate, triethylammoniumethyl (meth) acrylate and trimethylammoniumpropyl (meth) Acrylate etc.] and the like.

  The salt (a3) of the nitrogen atom-containing cationic monomer in (a) includes a salt obtained by neutralizing the above (a2) with an acid. Examples of the acid include mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid and boric acid, and organic acids such as formic acid, acetic acid and lactic acid.

  Preferred among (a2) and (a3) are dialkylaminoalkyl (meth) acrylate and its hydrochloride, and trialkylammonium alkyl (meth) acrylate, more preferably dimethylethylaminoacrylate and trimethylammonium ethylacrylate. It is.

  In the vinyl polymer (A), these (a) s may be used alone or in combination of two or more. Examples of the other monomer (b) include the following (b1) to (b6).

(B1) Unsaturated carboxylic acid ester:
(Meth) acrylates with alcohols having an alkyl group having 1 to 20 carbon atoms (methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl and 2-ethylhexyl); glycol (ethylene glycol, propylene glycol, 1, 4 -Butanediol, polyethylene glycol, polypropylene glycol and the like) mono (meth) acrylates; diesters of maleic acid, fumaric acid or itaconic acid with the above alcohols, etc.
(B2) Aliphatic hydrocarbon monomer:
Ethylene, propylene, butadiene and isobutylene.
(B3) Carboxylic acid vinyl ester or (meth) allyl ester:
Vinyl acetate, vinyl propionate and allyl acetate.
(B4) Aromatic vinyl monomer:
Styrene, α-methylstyrene, chlorostyrene, vinyltoluene and the like.
(B5) Halogen-containing monomer:
Vinyl chloride, vinylidene chloride, chloroprene, etc.
(B6) Nitrile group-containing monomer:
(Meth) acrylonitrile and the like.

  Preferred among (b) are (meth) acrylates with alcohols having alkyl groups, monoacrylates of glycols, styrene, ethylene and butadiene, and more preferred are mono (meth) acrylates of polyethylene glycol, ethylene and butadiene. It is.

  (A) is composed of 10 mol% or more of all monomers and 90 mol% or less of other monomers (b). If the proportion of (a) is 10 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, particularly preferably 50 mol% or more, (A) has an appropriate polarity, so that wettability is achieved. And the strength of the fiber-reinforced resin molded product is good.

The vinyl polymer (A) can be obtained by a usual method such as solution polymerization, emulsion polymerization or bulk polymerization, and examples thereof include the following methods.

  A method in which a monomer, a polymerization initiator and, if necessary, a chain transfer agent and / or a solvent are charged in a reactor, and after the inside of the container is replaced with nitrogen, polymerization is performed at a temperature of normal temperature to 150 ° C. with stirring for 1 to 30 hours. The reactor may be charged all at once or by a dropping method. As the solvent, water, methanol, isopropanol, acetone and the like can be used, and they may be used separately or in combination.

  Polymerization initiators include inorganic peroxides (persulfates, such as ammonium persulfate and potassium persulfate), organic peroxides (acyl peroxides such as benzoyl peroxide, and dialkyls such as di-t-butyl peroxide). Peroxides and hydroperoxides such as cumene hydroperoxide), azo compounds (azoisobutyronitrile, azobisdimethylvaleronitrile, etc.), and peroxides and reducing agents (as reducing agents) Sulfites, acidic sulfites or ferrous salts). The amount of the polymerization initiator used is usually 0.01 to 2% with respect to the monomer (in the following, unless otherwise specified,% represents% by weight), preferably 0.05 to 1%.

  As chain transfer agents, mercaptans (such as dodecyl mercaptan, tetradecyl mercaptan, hexadecyl mercaptan, and polyoxyethylene glycol di-2-mercaptoethyl ether), thiuram disulfide, xanthogen disulfide, phenol, sulfur, selenium, phosphine , Carbon tetrachloride, amines and nitroso compounds. The amount of the chain transfer agent used is usually 0.01 to 10%, preferably 0.1 to 5% based on the monomer.

  The vinyl polymer (A) of the present invention is usually obtained as an aqueous solution, an aqueous dispersion or a bulk. An aqueous solution or an aqueous dispersion is preferred, and the concentration of the vinyl polymer (A) in that case is preferably 10% or more, more preferably 30% or more.

  (A) has a contact angle of 55 ° or less, preferably 50 ° or less, more preferably 45 ° or less with a 10/90 weight ratio ethanol / water mixture when (A) is a dry film. is there. When the contact angle exceeds 55 °, the wettability with the matrix resin decreases, and the strength of the fiber-reinforced resin molded product becomes insufficient. The contact angle in the present invention is measured by the following method.

(1) A vinyl polymer (A) or a solution thereof is applied to an area of at least 10 cm ² or more on a 26 mm × 76 mm glass plate having a thickness of 1 mm using an applicator. The coating amount is such that the coating thickness after drying is at least 50 microns.
(2) When (A) is a solution, the solvent is removed in a dryer. The conditions are preferably as short as possible as long as (A) does not change and bubbles are not formed. For example, when (A) is an aqueous solution, it is at least 130 minutes at 130 ° C., and when it is an isopropanol solution, it is 80 ° C. At least 45 minutes and in the case of methanol solution at 70 ° C. for at least 45 minutes. The end point of the solvent removal is when the weight change of the glass plate with the film becomes 0.1% or less in 45 minutes.
(3) A drop of a 10/90 weight ratio ethanol / water mixture was dropped on the obtained film, and in a contact angle measurement mode of a fully automatic interfacial tension meter “Model PD-W” manufactured by Kyowa Interface Science Co., Ltd. The contact angle is measured 10 times per sample, and the average value is obtained. In order to obtain a vinyl polymer having a lower contact angle, it can be obtained by increasing the proportion of the monomer (a).

  The content of the vinyl polymer (A) per solid content of the fiber sizing agent of the present invention is preferably 20% or more, more preferably 30% or more, and particularly preferably 50% or more, from the viewpoint of fluff suppression and molded product strength. It is. In the present invention, “solid content” refers to components other than the aqueous medium.

  The sizing agent for fibers of the present invention may contain other resin (B) and / or emulsifier (C) in addition to the vinyl polymer (A). When the other resin (B) is contained, the sizing property is further improved, and when the emulsifier (C) is contained, the sizing agent adhering to the fiber becomes smooth, so that the fiber fluff becomes more difficult to reach.

  As other resin (B), a thermoplastic resin (B1) and a thermosetting resin (B2) are mentioned.

  Examples of the thermoplastic resin (B1) include polyethylene resin, polypropylene resin, polystyrene resin, polyurethane resin, polyurethane urea resin, polyester resin, polyamide resin, and acrylic resin. Examples of other thermoplastic resins include those described in International Publication WO2003 / 09015, International Publication WO2004 / 067612, or Japanese Patent Application Laid-Open No. 2005-120282. Of the thermoplastic resins (B1), polyurethane resins, polyurethane urea resins, and polyamide resins are preferable from the viewpoint of convergence.

  Examples of the thermosetting resin (B2) include epoxy resins, (meth) acrylate-modified resins, unsaturated polyester resins, and the like.

  As an epoxy resin, the thing of Unexamined-Japanese-Patent No. 2007-39868, etc. are mentioned. Of the epoxy resins, diglycidyl ether is preferable from the viewpoint of the strength of the molded article, more preferably diglycidyl ether of dihydric phenol, and particularly preferable is diglycidyl ether of bisphenol A (bisphenol A type epoxy resin). is there.

  Examples of the (meth) acrylate-modified resin include those described in JP-A-2007-39868.

  As unsaturated polyester resin, the thing of Unexamined-Japanese-Patent No. 2007-39868, etc. are mentioned.

  Among the other resins (B), polyurethane resin, polyurethane urea resin, polyamide resin, epoxy resin, (meth) acrylate-modified resin and unsaturated polyester resin are preferable from the viewpoint of the strength of the molded body, and polyurethane resin, More preferred are polyurethaneurea resins, epoxy resins and unsaturated polyester resins.

  The other resin (B) is usually in the form of an aqueous dispersion or a melt, and is preferably an aqueous dispersion emulsified and dispersed using an emulsifier (C) described later. The concentration of the solid content of the aqueous dispersion is usually 10% or more, preferably 30% or more. The other resin (B) is usually added in the form of an aqueous dispersion, but the content of (B) based on the solid content of the sizing agent is preferably 70% or less from the viewpoint of sizing property and strength of the molded product. More preferably, it is 60% or less, particularly preferably 50% or less. The solid content weight ratio [(B) / (A)] of the vinyl polymer (A) and the other resin (B) is preferably 0/1 to 3/1, more preferably 0/1 to 2. / 1.

  The emulsifier (C) may be used as an emulsifier when the other resin (B) is used as an aqueous dispersion, or may be added separately. As the emulsifier (C), known surfactants such as nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants (for example, JP 2006-124877 A, International Publication WO 2003/37964). No. pamphlet etc.). Two or more of these may be used in combination. In addition, as an emulsifier (C), in addition to what is described in the said well-known literature, polyhydric (2-8 valence) alcohol (C2-C6; ethylene glycol, propylene glycol, glycerol, pentaerythritol, sorbitan, etc.) ) Alkylene oxide (hereinafter abbreviated as AO) adduct {weight average molecular weight (hereinafter abbreviated as Mw) 500 to 100,000}, alkylphenol (carbon number 10 to 20) AO adduct (Mw 500 to 5000) sulfate ester salt (Sodium salt, potassium salt, ammonium salt, alkanolamine salt, etc.), arylalkylphenol {styrenated phenol (carbon number 14-62), styrenated cumylphenol, styrenated cresol (carbon number 15-61), etc.} AO Sulfate ester of adduct (Mw500-5000) Etc. The. In the emulsifier (C), examples of AO include ethylene oxide (hereinafter abbreviated as EO), 1,2-propylene oxide (hereinafter abbreviated as PO), butylene oxide, and the like. Products, block adducts, and mixed adducts thereof. When the emulsifier (C) is contained, the content of (C) based on the solid content of the sizing agent is preferably 30% or less, more preferably, from the viewpoint of the strength of the molded product and the fluffing when used in the fiber reinforced resin. It is 20% or less, particularly preferably 10% or less. The solid content weight ratio [(C) / (A)] of the vinyl polymer (A) and the emulsifier (C) is preferably 0/1 to 1/1, and more preferably 0/1 to 0.5. / 1.

  Since the vinyl polymer (A) is preferably an aqueous solution or dispersion and the other resin (B) is preferably an aqueous dispersion, the fiber sizing agent of the present invention preferably contains an aqueous medium. To do. By containing the aqueous medium, it is easy to adjust the amount of the vinyl polymer (A) attached to the fiber to an appropriate amount, so that a fiber bundle having further excellent strength when formed into a molded body can be obtained. As the aqueous medium, water, methanol, isopropanol, acetone and the like, and the aqueous medium described in JP-A No. 2006-124877 can be used, and they may be used separately or mixed. Of the aqueous medium, water and a mixed solvent of a hydrophilic organic solvent and water are preferable from the viewpoint of safety and the like, and water is more preferable.

  The form of the fiber sizing agent of the present invention is not particularly limited, and examples thereof include an aqueous solution, an aqueous dispersion, and a molten state as described above. From the viewpoint of cost and the like, a high-concentration aqueous solution or aqueous dispersion is used during distribution. In the production of a fiber bundle, a low concentration aqueous solution or aqueous dispersion is preferred. That is, a fiber bundle that reduces the transportation cost and storage cost by distributing it as a high concentration aqueous solution or aqueous dispersion, and gives excellent molded body strength by treating the fiber with a low concentration aqueous solution or aqueous dispersion. Can be manufactured. A low-concentration aqueous solution or dispersion can be easily produced by diluting a high-concentration aqueous solution or dispersion with an aqueous medium. From the viewpoint of storage stability and the like, the solid concentration of the high-concentration aqueous solution or aqueous dispersion is preferably 6 to 60%, more preferably 15 to 55%, and particularly preferably 30 to 50%. On the other hand, the solid content concentration in the low-concentration aqueous solution or aqueous dispersion is preferably 0.1 to 10%, more preferably 0.2 to 5%.

  The fiber sizing agent of the present invention may contain known additives (smoothing agents, preservatives, antioxidants and the like described in JP-A No. 2006-124877). When these additives are contained, the content is 20% or less in the solid content of the sizing agent.

The following production methods can be applied to the method for producing the fiber sizing agent of the present invention.
(1) A method of producing an aqueous dispersion-like sizing agent by mixing an aqueous solution of a vinyl polymer (A) and an aqueous dispersion of another resin (B) [the aqueous dispersion of (B) contains an emulsifier ( C) is used].
(2) A mixture of an aqueous solution of the vinyl polymer (A), the other resin (B) and the emulsifier (C) is adjusted to 20 to 90 ° C. and emulsified and dispersed while introducing an aqueous medium therein. A method for producing a dispersion-like sizing agent.
(3) A method for producing a molten sizing agent by uniformly mixing a vinyl polymer (A), other resin (B) and an emulsifier (C) at 40 to 150 ° C.
(4) A method of producing an aqueous dispersion-like sizing agent by emulsifying and dispersing the molten sizing agent into an aqueous medium at a temperature of 60 ° C. or lower.
There is no limitation on the mixing or emulsifying and dispersing apparatus, and a stirring blade (blade shape: chi-shaped, three-stage paddle, etc.), nauter mixer, ribbon mixer, conical blender, mortar mixer, universal mixer [universal mixing stirrer 5DM-L, ( Sanei Seisakusho Co., Ltd.] and Henschel mixer can be used.

  The fiber to which the fiber sizing agent of the present invention can be applied is carbon fiber or aramid fiber for fiber reinforced resin. From the viewpoint of the strength of the molded body, carbon fibers are preferred.

  The fiber bundle of the present invention is a fiber bundle obtained by treating carbon fiber or aramid fiber with the above fiber sizing agent. These fiber bundles are fiber bundles in which about 3000 to 30,000 fibers are bundled. Examples of the fiber processing method include a spray method and a dipping method. The amount of the sizing agent attached to the fiber is preferably 0.05 to 5%, more preferably 0.2 to 2.5% based on the weight of the fiber in terms of the vinyl polymer (A). is there. Within this range, the strength of the molded body is further improved.

  The fiber product of the present invention is a fiber product obtained by processing the fiber bundle, and examples thereof include woven fabric, knitted fabric, nonwoven fabric (felt, mat, paper, etc.), chopped fiber and milled fiber.

  The composite intermediate of the present invention is a composite intermediate comprising the fiber bundle and the matrix resin, or the fiber product and the matrix resin. The composite intermediate may contain a curing catalyst for a matrix resin, if necessary. When the catalyst is contained, the strength of the molded body is further improved. Examples of the matrix resin include thermosetting resins and thermoplastic resins (such as those described in International Publication WO2003 / 09015 pamphlet), preferably the other resin (B), more preferably a polyamide resin, An epoxy resin, an unsaturated polyester resin, and a (meth) acrylate modified resin. Examples of the catalyst include known curing agents for epoxy resins and curing accelerators (Japanese Patent Application Laid-Open No. 2005-213337).

  The weight ratio of the matrix resin to the fiber bundle (matrix resin / fiber bundle) is preferably 10/90 to 90/10, more preferably 20/80 to 70/30, particularly preferably from the viewpoint of the strength of the molded body. 30/70 to 60/40. In the case of containing a catalyst, the content of the catalyst is preferably 10% or less, more preferably 0.1 to 5%, particularly preferably 1 to 3% with respect to the matrix resin from the viewpoint of the strength of the molded body. .

  The composite intermediate is obtained by mixing a matrix resin that has been melted with heat (melting temperature: 60 to 300 ° C.) or a matrix resin diluted with a solvent (such as acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, and ethyl acetate) into a fiber bundle (fiber It can be manufactured by impregnating the product. When a solvent is used, it is preferable to dry the composite intermediate to remove the solvent.

  The molded product of the present invention can be obtained by separately introducing a fiber bundle or fiber product and a matrix resin into a mold and molding and / or curing, or molding and / or curing a composite intermediate. When the matrix resin is a thermoplastic resin, it can be formed into a molded body by heat molding in a mold and solidifying at room temperature. When the matrix resin is a thermosetting resin, it can be formed into a molded body by being heat-molded in a mold and cured. Curing does not need to be completed, but it is preferable that the molded body is cured to such an extent that the shape can be maintained. After molding, it may be further cured by heating. The method of thermoforming is not particularly limited. For example, a filament wiping molding method (a method of winding and thermoforming a rotating mandrel while applying tension), a press molding method (a method of laminating prepreg sheets and thermoforming), an autoclave And a method of injection molding by mixing a chopped fiber or a milled fiber with a matrix resin.

[Example]
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Hereinafter, unless otherwise indicated, parts are parts by weight, and% is% by weight.

The contact angle between the vinyl polymer (A) film and a 10/90 weight ratio ethanol / water mixture was measured by the following method.
(1) A vinyl polymer (A) or a solution thereof is applied to an area of at least 10 cm 2 or more on a 26 mm × 76 mm glass plate having a thickness of 1 mm using an applicator. The coating amount is such that the coating thickness after drying is at least 50 microns.
(2) When (A) is a solution, the solvent is removed in a dryer. Conditions are preferably as short as possible as long as (A) does not change and no bubbles are formed. For example, when (A) is an aqueous solution, it is at least 130 minutes at 130 ° C., and when it is an isopropanol solution, it is 80 ° C. At least 45 minutes and in the case of methanol solution at 70 ° C. for at least 45 minutes. The end point of the solvent removal is when the weight change of the glass plate with the film becomes 0.1% or less in 45 minutes.
(3) A drop of a 10/90 weight ratio ethanol / water mixture was dropped on the obtained film, and in a contact angle measurement mode of a fully automatic interfacial tension meter “Model PD-W” manufactured by Kyowa Interface Science Co., Ltd. The contact angle is measured 10 times per sample, and the average value is obtained.

Production Example 1 [Synthesis of polyacrylic acid ammonium salt aqueous solution (A-1)]
After charging 300 parts of isopropanol and 100 parts of water into a pressure vessel and sufficiently replacing with nitrogen, the temperature was raised to 100 ° C. with stirring. 70 parts of a 5% aqueous solution of sodium persulfate and 320 parts of acrylic acid were separately dropped into a pressure vessel separately using a pump, and sodium persulfate was dripped over 4 hours and acrylic acid over 3 hours. The temperature during dropping was kept at 100 ° C. and the pressure was kept at 0.1 MPa. Further, after aging at 80 ° C. for 1 hour, isopropanol was distilled off at 100 ° C. under nitrogen flow. After cooling to 25 ° C., 270 parts of 28% aqueous ammonia and 229 parts of water were charged and neutralized to obtain 989 parts of an aqueous solution of ammonium polyacrylate (A-1) (polyacrylate ammonium salt concentration 40%). The contact angle between the coating (A-1) and the 10/90 weight ratio ethanol / water mixture (hereinafter sometimes simply referred to as “the contact angle of the coating”) was 31 °.

Production Example 2 [Synthesis of Maleic Acid / Butadiene Copolymer Ammonium Salt Aqueous Solution (A-2)]
500 parts of methyl ethyl ketone and 125 parts of maleic anhydride were charged into a pressure vessel and sufficiently replaced with nitrogen, and then heated to 60 ° C. with stirring. 30 parts of azobisisobutyronitrile 10% methyl ethyl ketone solution and 70 parts of butadiene are dropped separately into a pressure vessel using a pump over 5 hours, the temperature during dropping is 60 ° C., and the pressure is 0.1 MPa. Retained. After aging for 3 hours under the same conditions, methyl ethyl ketone was distilled off under conditions of 60 ° C. and −0.1 MPa, neutralized by adding 155 parts of 28% ammonia water and 300 parts of water, and aqueous maleic acid / butadiene copolymer solution. (A-2) 653 parts (maleic acid / butadiene = 50 mol% / 50 mol% copolymer ammonium salt concentration 40%) were obtained. The contact angle of the film (A-2) was 38 °.

Production Example 3 [Synthesis of polydimethylaminoethyl acrylate (A-3)]
After 410 parts of isopropanol was charged in a pressure vessel and sufficiently replaced with nitrogen, the temperature was raised to 100 ° C. with stirring. 70 parts of 5% aqueous solution of sodium persulfate and 320 parts of dimethylaminoethyl acrylate were simultaneously dropped into a pressure vessel separately using a pump. The aqueous solution of sodium persulfate was taken for 4 hours, and the dimethylaminoethyl acrylate was taken for 3 hours. The whole amount was added dropwise. The temperature during dropping was kept at 100 ° C. and the pressure was kept at 0.1 MPa. The mixture was aged at 80 ° C. for 1 hour to obtain 800 parts of an isopropanol solution (A-3) of polydimethylaminoethyl acrylate (polydimethylaminoethyl acrylate concentration: 40%). The contact angle of the film of (A-3) was 53 °.

Production Example 4 [Synthesis of polytrimethylammonium ethyl acrylate (A-4)]
After charging 400 parts of isopropanol and 100 parts of water into a pressure vessel and sufficiently replacing with nitrogen, the temperature was raised to 100 ° C. with stirring. 70 parts of sodium persulfate 5% aqueous solution and 400 parts of trimethylammonium ethyl acrylate chloride are simultaneously dropped into a pressure vessel separately using a pump, the sodium persulfate aqueous solution takes 4 hours, and the trimethylammonium ethyl acrylate chloride 3 hours The whole amount was added dropwise. The temperature during dropping was kept at 100 ° C. and the pressure was kept at 0.1 MPa. After aging at 80 ° C. for 1 hour, isopropanol was distilled off at 100 ° C. under nitrogen flow, 430 parts of water was added, and 1000 parts of polytrimethylammonium ethyl acrylate (A-4) (polytrimethylammonium ethyl acrylate concentration 40 %). The contact angle of the film (A-4) was 48 °.

Production Example 5 [Synthesis of Ammonium Methacrylate / Methyl Methacrylate Copolymer Aqueous Solution (A-5)]
After charging 300 parts of isopropanol and 100 parts of water into a pressure vessel and sufficiently replacing with nitrogen, the temperature was raised to 100 ° C. with stirring. A mixture of 70 parts of 5% aqueous sodium persulfate solution and 82 parts of methacrylic acid and 222 parts of methyl methacrylate was simultaneously started dropwise into a pressure vessel using a pump separately. The total amount of the mixed solution of methyl methacrylate was dropped over 3 hours. The temperature during dropping was kept at 100 ° C. and the pressure was kept at 0.1 MPa. After aging at 80 ° C. for 1 hour, isopropanol was distilled off at 100 ° C. under nitrogen flow. After cooling to 25 ° C., 61 parts of 28% ammonia water and 265 parts of water were added to neutralize, and 800 parts of ammonium methacrylate / methyl methacrylate aqueous solution (A-5) (ammonium methacrylate / methacrylic acid). Methyl = 30 mol% / 70 mol% copolymer concentration 40%). The contact angle of the film (A-5) was 54 °.

Production Example 6 [Synthesis of Ammonium Methacrylate / Methyl Methacrylate Copolymer Aqueous Solution (A-6)]
Production Example 5 except that 82 parts of methacrylic acid was changed to 26.5 parts, 222 parts of methyl methacrylate was 277.5 parts, 61 parts of 28% aqueous ammonia was 19 parts, and 269 parts of water added after aging was 280 parts. Similarly, 770 parts of ammonium methacrylate salt / methyl methacrylate copolymer aqueous solution (A-6) (ammonium methacrylate salt / methyl methacrylate = 10 mol% / 90 mol% copolymer concentration 40%) was obtained. It was. The contact angle of the film (A-6) was 55 °.

Production Example 7 [Synthesis of aqueous polyurethane polyurea resin aqueous dispersion (B-1)]
An isocyanate group-terminated prepolymer having an isocyanate group (NCO) content of 3.3% is prepared by reacting 100 parts of polyneopentyl adipate diol (number average molecular weight 1,000, melting point: about 0 ° C.) with 34 parts of isophorone diisocyanate at 90 ° C. for 4 hours. Got. This is cooled to 30 ° C., and 17 parts of “Ionette MG-150” [manufactured by Sanyo Chemical Industries, Ltd.], 10 parts of “New Pole PE-62” (manufactured by Sanyo Chemical Industries, Ltd.) and 30 parts of water are used as emulsifiers. At the same time, thoroughly mixed and dispersed with a homomixer, further diluted with 200 parts of water, and subjected to a water elongation reaction at 60 ° C. for 5 hours to give a solid content of 41% (polyurethane urea resin 34.1% + Emulsifier (6.9%), and 391 parts of an aqueous polyurethane polyurea resin (B-1) having a urea group content of 2.3% in the resin.

Production Example 8 [Synthesis of unsaturated polyester resin aqueous dispersion (B-2)]
316 parts of bisphenol A ethylene oxide adduct ("New Pole BPE-20" manufactured by Sanyo Chemical Industries Co., Ltd.) with 2 parts of EO added to 1 part of bisphenol A, 116 parts of fumaric acid and 0.5% of tetraisopropoxy titanate The reaction was carried out for 10 hours while distilling off water at 170 ° C. under a nitrogen stream in a glass reaction vessel to obtain an unsaturated polyester resin having an acid value of 21. 300 parts of this unsaturated polyester and 100 parts of an emulsifier (PO and EO adduct of styrenated phenol, Rhodia Nikka Co., Ltd., “Soprophor 796 / P”) are mixed into a universal mixer [universal mixing agitator manufactured by Sanei Seisakusho Co., Ltd.] Mix uniformly at 70 ° C. for 30 minutes. A total of 600 parts of water was dropped into this over 6 hours to obtain 1000 parts of an unsaturated polyester resin aqueous dispersion (solid content 40%; unsaturated polyester resin 30% + emulsifier 10%) (B-2). .

Production Example 9 [Synthesis of bisphenol A type epoxy resin aqueous dispersion (B-3)]
300 parts of bisphenol A type epoxy resin (“Epicoat 828”, manufactured by Japan Epoxy Resin Co., Ltd.), 100 parts of emulsifier (PO and EO adduct of styrenated phenol, “Soprophor 796 / P” manufactured by Rhodia Nikka Co., Ltd.) The mixture was mixed uniformly at 70 ° C. for 30 minutes in a machine [Universal Mixing Stirrer, Sanei Seisakusho Co., Ltd.]. A total of 600 parts of water was dropped into this over 6 hours to obtain 1000 parts of a bisphenol A type epoxy resin aqueous dispersion (solid content 40%; epoxy resin 30% + emulsifier 10%) (B-3).

Comparative Production Example 1 [Synthesis of water-soluble vinyl polymer aqueous solution (A′-1)]
A flask was charged with 259 parts of acrylic acid, 47 parts of sodium methallylsulfonate, 69 parts of hydroxypolyethoxy (ethoxy group polymerization degree = 8) ethyl monomethacrylate, 17 parts of methyl methacrylate and 888 parts of water, and 48% of sodium hydroxide. After 220 parts of the aqueous solution was added for neutralization and dissolved uniformly, the atmosphere was replaced with nitrogen. The temperature of the reaction system is kept at 60 ° C. in a warm water bath, 3 parts of potassium persulfate is added to start polymerization, and the polymerization reaction is continued for 6 hours to complete the polymerization (sodium acrylate / methallyl). Sodium sulfonate / hydroxypolyethoxyethyl monomethacrylate / methyl methacrylate copolymer concentration 30%) (A′-1) 1503 parts were obtained. The contact angle of the film (A′-1) was 29 °.

Comparative Production Example 2 [Synthesis of Maleic Acid / Ethylene Copolymer Sodium Salt Aqueous Solution (A′-2)]
In a container equipped with a stirrer, 144 parts of maleic acid / ethylene copolymer (ALDRICH, maleic acid 50 mol%), 326 parts of 24.5% aqueous sodium hydroxide solution were charged to neutralize the product (maleic acid). Acid / ethylene copolymer sodium salt aqueous solution concentration 40%) (A′-2) 470 parts were obtained. The contact angle of the film (A′-2) was 32 °.

Comparative Production Example 3 [Synthesis of Ammonium Methacrylate / Methyl Methacrylate Copolymer Aqueous Solution (A′-3)]
Production Example except that 82 parts of methacrylic acid was changed to 13.1 parts, 222 parts of methyl methacrylate was 290.9 parts, 61 parts of 28% ammonia water was 9.5 parts, and 269 parts of water added after aging was changed to 283 parts. As in Example 5, 766.5 parts of ammonium methacrylate salt / methyl methacrylate aqueous solution (A′-3) (ammonium methacrylate salt / methyl methacrylate = 5 mol% / 95 mol% copolymer concentration) 40%). The contact angle of the film of (A′-3) was 59 °.

Examples 1 to 13 and Comparative Examples 1 to 3
The sizing agents (S-1) to (S-13) and the sizing agents (S′-1) to (S′-3) were prepared according to the weight parts shown in Table 1 and mixed. In addition, all the compounding amounts in Table 1 are apparent compounding amounts and include an aqueous medium. Moreover, the solid content ratio of (A) / (B) / (C) is the content in terms of solid content of each component when the solid content of the sizing agent is 100 parts. These sizing agents were dried at 130 ° C. for 45 minutes to evaporate the medium and the viscosity at 100 ° C. was measured. Further, these sizing agents are diluted with water so that the solid concentration in the sizing agent is 1.5%, carbon fibers (fineness 800 tex, number of filaments 12,000) are immersed to impregnate the sizing agent, The carbon fiber bundle (1) obtained by drying with hot air at 150 ° C. for 3 minutes was evaluated for fuzziness, adhesion to the matrix resin (interlaminar shear strength) and bending strength of the molded product, and the results are shown in Table 1. It was.

The viscosity was an average value measured twice under the following conditions.
Model: BL type viscometer [manufactured by Toki Sangyo Co., Ltd.]
Rotor rotation speed: 60 rpm (viscosity 10 Pa · s or less)
6 rpm (viscosity 10 Pa · s or more)
Measurement temperature: 100 ° C
Rotor: No. 4

  Fluff was measured under the following conditions. Five chrome-plated stainless steel rods with a diameter of 2 mm were arranged in a zigzag manner so that the carbon fiber bundle (1) passed through the surface at a contact angle of 120 ° at 15 mm intervals. The carbon fiber bundle (1) was zigzag between the stainless bars, and a tension of 1 kg was applied. Immediately before the winding roll, the carbon fiber bundle (1) was sandwiched between two 10 cm × 10 cm urethane foams having a load of 1 kg and rubbed at a speed of 1 m / min for 5 minutes. During this time, the weight of the fluff adhered to the sponge was measured. The smaller the value, the better the fluff characteristics.

Interlaminar shear strength (ILSS) was evaluated as follows.
The carbon fiber bundles are aligned in one direction and placed in a mold (length 10 cm x width 10 cm, thickness 2.5 mm), and bisphenol A type diglycidyl ether (epoxy equivalent 190) / BF ₃ monoethylamine salt = Add matrix resin prepared to 100/3 parts and impregnate under reduced pressure (650 Pa). At this time, the amount of the carbon fiber bundle is adjusted so that the volume content of the fiber is 60%. After impregnation, it is cured under pressure (0.49 MPa) at 150 ° C. for 1 hour, and further cured at 140 ° C. under the same pressure for 4 hours. The cured product thus obtained was cut with a diamond cutter, and the interlaminar shear strength (ILSS) of a test piece having a thickness of 2.5 mm, a width of 6.0 mm, and a length of 12 mm was measured according to ASTM D-2344. The larger the value, the better the interlaminar shear strength. In addition, when the interlaminar shear strength is excellent, the compact strength is excellent.

The bending strength of the molded product was evaluated as follows.
A carbon fiber bundle is aligned in one direction and placed in a mold (a frame mold having a length of 10 cm × width of 10 cm and a thickness of 2 mm), heated to 250 ° C. and melted therein (manufactured by Ube Industries, Ltd .: “ UBE nylon 66 1011FB "] is added and impregnated. At this time, the amount of the carbon fiber bundle is adjusted so that the volume content of the fiber becomes 30%. After the impregnation, molding was performed at 250 ° C. for 5 minutes under pressure (0.59 MPa). The molded product thus obtained was cut with a diamond cutter, and a test piece having a thickness of 2 mm, a width of 10 mm, and a length of 12 mm was subjected to bending strength according to JIS K7074 (span / thickness ratio = 32, test speed 5.0 mm / Min). The larger the value, the better the bending strength.

  A carbon fiber bundle or an aramid fiber bundle obtained by processing with the fiber sizing agent of the present invention and a fiber product obtained by processing the same are suitable for a high-strength fiber-reinforced resin with less fuzz. This fiber reinforced resin can be suitably used as various civil engineering / architectural materials, transport aircraft materials, sports equipment materials, power generator materials, and the like.

Claims (10)

  A fiber sizing agent used for carbon fibers or aramid fibers for fiber reinforced resins, selected from the group consisting of ammonium salts of anionic monomers, nitrogen atom-containing cationic monomers, and nitrogen atom-containing cationic monomers. One or more monomers (a) contain a vinyl polymer (A) comprising 10 mol% or more, and the other monomer (b) is 90 mol% or less. The vinyl polymer (A) comprises (A) A sizing agent for fibers, which is a vinyl polymer having a contact angle of 55 ° or less between a film obtained by drying and a 10/90 weight ratio ethanol / water mixed solution.   The sizing agent for fibers according to claim 1, wherein the viscosity at 100 ° C is 0.5 to 20 Pa · s.   The sizing agent for fibers according to claim 1 or 2, wherein the ammonium salt of the anionic monomer is an unsaturated carboxylic acid ammonium salt.   The fiber sizing agent according to any one of claims 1 to 3, wherein the nitrogen atom-containing cationic monomer is a dialkylaminoalkyl (meth) acrylate.   Furthermore, one or more types of resin chosen from the group which consists of a polyurethane resin, a polyurethane urea resin, a polyamide resin, an epoxy resin, a (meth) acrylate modified resin, and an unsaturated polyester resin are contained in any one of Claims 1-4. The sizing agent for fibers as described.   A fiber bundle obtained by treating carbon fiber or aramid fiber with the fiber sizing agent according to any one of claims 1 to 5.   A fiber product comprising the fiber bundle according to claim 6.   A composite intermediate comprising the fiber bundle according to claim 6 or the fiber product according to claim 7 and a resin.   A molded body formed by molding and / or curing the fiber bundle according to claim 6 or the fiber product according to claim 7 and a resin.   The molded object formed by shape | molding and / or hardening | curing the composite intermediate body of Claim 9.