Sizing agent composition for fibers, fiber bundle, fiber product, and composite material

Abstract

The purpose of the present invention is to provide a sizing agent composition for fibers, which has a fluff-suppressing effect and excellent sizing properties. The present invention relates to a sizing agent composition for fibers, comprising a novolac epoxy resin (A1) and an aromatic nonionic surfactant (B1).

Description

Technical Field

[0001] The invention relates to a sizing agent composition for fibers, a fiber bundle, a fiber product and a composite material. Background Art

[0002] In recent years, composite materials composed of matrix resins such as unsaturated polyester resins, phenolic resins, epoxy resins, and polypropylene resins and various fibers have been widely used in fields such as sports equipment, leisure products, and aircraft. These composite materials use fibers such as glass fibers, carbon fibers, ceramic fibers, metal fibers, mineral fibers, rock fibers, and slug fibers. During the processing steps to create these composite materials, these fibers are typically treated with a sizing agent (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2013 / 146024 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In the sizing process of applying a sizing agent to fibers to form a fiber bundle, the sizing liquid (sizing agent) is required to penetrate between the fibers in the fiber bundle. However, the sizing agent described in Patent Document 1 cannot fully penetrate between the fibers when the fiber bundle has a large number of fibers, resulting in an inability to sufficiently suppress fuzzing of the fiber bundle.

[0008] As a method for solving this problem, sizing agents containing bisphenol-type epoxy resins have been studied. As a result, the fuzz suppression effect is improved compared to the sizing agent described in Patent Document 1. However, further improvement in sizing properties is required.

[0009] An object of the present invention is to provide a fiber sizing composition having a fuzz-suppressing effect and excellent sizing properties.

[0010] Means for solving problems

[0011] The present inventors have conducted studies to achieve the above-mentioned object and have consequently completed the present invention.

[0012] That is, the present invention is as follows.

[0013] [1] A fiber sizing composition comprising a novolac-type epoxy resin (A1) and an aromatic nonionic surfactant (B1).

[0014] [2] The fiber sizing composition as described in [1], which contains 20 to 90% by weight of a novolac-type epoxy resin (A1) and 1 to 20% by weight of an aromatic nonionic surfactant (B1), based on the weight of the non-volatile components contained in the fiber sizing composition.

[0015] [3] The fiber sizing composition according to [1] or [2], further comprising 5 to 70% by weight of a polyether-containing compound (C) based on the weight of the non-volatile components in the fiber sizing composition.

[0016] [4] The fiber sizing composition according to [3], wherein the polyether-containing compound (C) is a compound having an ester group obtained by reacting a diol (c2) with a dicarboxylic acid or its anhydride (c1).

[0017] [5] The fiber sizing composition according to [4], wherein the dicarboxylic acid or its anhydride (c1) is an aromatic dicarboxylic acid or its anhydride.

[0018] [6] The fiber sizing composition as described in [4] or [5], wherein the diol (c2) contains diol (c21), and the diol (c21) has one or more polyoxyethylene groups composed of two or more consecutive oxyethylene groups in one molecule, and the number of oxyethylene groups in each polyoxyethylene group is 2 to 60.

[0019] [7] The fiber sizing composition according to any one of [1] to [6], wherein the epoxy group concentration in the non-volatile component contained in the fiber sizing composition is 1.5 meq / g or more.

[0020] [8] A fiber bundle obtained by treating at least one fiber selected from the group consisting of carbon fiber, glass fiber, aramid fiber, ceramic fiber, metal fiber, mineral fiber and slag fiber with the fiber sizing composition described in any one of [1] to [7].

[0021] [9] A fiber product comprising the fiber bundle described in [8].

[0022]

[10] A composite material comprising the fiber bundle described in [8] and a matrix resin.

[0023]

[11] A composite material comprising the fiber product described in [9] and a matrix resin.

[0024] Effects of the Invention

[0025] According to the present invention, a sizing composition for fibers that suppresses fuzzing and has excellent sizing properties can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a side view schematically showing the arrangement of the evaluation device and the carbon fiber bundle in the fuzz evaluation. DETAILED DESCRIPTION

[0027] <Novolac type epoxy resin (A1)>

[0028] Examples of the novolac-type epoxy resin (A1) include bisphenol A novolac-type epoxy resin, phenol novolac-type epoxy resin, and cresol novolac-type epoxy resin.

[0029] From the viewpoint of sizing properties, the novolac-type epoxy resin (A1) preferably has a viscosity of 5 Pa·s or more (more preferably 10 Pa·s or more) at 60°C or is solid at 60°C.

[0030] As the novolac-type epoxy resin (A1), a commercially available item can be used.

[0031] Examples of commercially available products of bisphenol A novolac-type epoxy resins include "157S70" (solid at 60° C.) manufactured by Mitsubishi Chemical Corporation.

[0032] Commercially available products of phenol novolac-type epoxy resins include "jER154" manufactured by Mitsubishi Chemical Corporation (viscosity at 60°C is 14 Pa·s), "EPICLON N-740" manufactured by DIC Corporation (viscosity at 60°C is 13 Pa·s), "EPICLON N-770" manufactured by DIC Corporation (solid at 60°C), "YDPN-638" manufactured by Nippon Steel Chemicals Co., Ltd. (viscosity at 60°C is 15 Pa·s), and "EPPN-201" manufactured by Nippon Kayaku Co., Ltd. (solid at 60°C).

[0033] Examples of commercially available cresol novolac-type epoxy resins include "YDCN-700-7" manufactured by Nippon Steel Chemicals Co., Ltd. (viscosity of 30,000 Pa·s at 60°C), "EOCN-103S" manufactured by Nippon Kayaku Co., Ltd. (solid at 60°C), and "EOCN-104S" manufactured by Nippon Kayaku Co., Ltd. (solid at 60°C).

[0034] Among the novolac-type epoxy resins (A1), phenol novolac-type epoxy resins and cresol novolac-type epoxy resins are preferred from the viewpoint of sizing properties, and cresol novolac-type epoxy resins are more preferred.

[0035] In addition, the novolac-type epoxy resin (A1) may be used individually by 1 type, and may use 2 or more types together.

[0036] In the present invention, "solid at 60°C" means that the object does not flow within 10 seconds after tilting a container containing the object at 60°C. The "tilted container" state refers to a state in which the container, placed on a horizontal platform, is tilted by at least 10° relative to its pre-tilt state. "Before tilting" refers to a state in which the container is placed on the horizontal platform.

[0037] In the present invention, "viscosity at 60°C" refers to the viscosity measured at a strain of 1%, a frequency of 1 Hz, and a temperature of 60°C. This viscosity can be measured using a viscoelasticity measuring apparatus (e.g., "MCR302" manufactured by Anton Paar Japan Co., Ltd.) under the following measurement conditions.

[0038] Measurement mode: Shear mode

[0039] Plate: Parallel plate (25mm diameter)

[0040] Distance between boards: 1mm

[0041] The content of the novolac-type epoxy resin (A1) in the fiber sizing composition of the present invention is preferably 20 to 90% by weight, more preferably 30 to 85% by weight, based on the weight of the nonvolatile components contained in the fiber sizing composition, from the viewpoint of sizing properties.

[0042] In the present invention, the non-volatile component refers to the residue obtained by heating and drying 1 g of a sample in a glass dish at 130° C. for 45 minutes in a circulating air dryer without covering the sample.

[0043] <Aromatic nonionic surfactant (B1)>

[0044] Examples of the aromatic nonionic surfactant (B1) include compounds obtained by adding an alkylene oxide (AO) to a compound having an aromatic ring. Specifically, examples include compounds obtained by directly adding AO to an alkyl (alkyl group having 1 to 18 carbon atoms) phenol, compounds obtained by directly adding AO to styrenated (1 to 10 mol) phenol, and compounds obtained by directly adding AO to styrenated (1 to 10 mol) cumylphenol. Examples of AO include those having 2 to 4 carbon atoms, such as EO (ethylene oxide), PO (1,2-propylene oxide or 1,3-propylene oxide), BO (1,2-butylene oxide, 1,3-butylene oxide, 2,3-butylene oxide or 1,4-butylene oxide), and combinations of two or more thereof.

[0045] The average added mole number of AO is preferably 5 to 65. When a plurality of AOs are contained, the total value of the average added mole number of each AO is the average added mole number of AO.

[0046] As the aromatic nonionic surfactant (B1), a commercially available product can be used. Examples of commercially available aromatic nonionic surfactants include Soprophor 796 / P [manufactured by Solvay Nicca, Ltd.], Soprophor TSP / 724 [manufactured by Solvay Nicca, Ltd.], and Soprophor TSP / 461 [manufactured by Solvay Nicca, Ltd.] (all of which are PO and EO adducts of styrenated phenol).

[0047] The aromatic nonionic surfactant (B1) is preferably a compound obtained by directly adding AO to styrenated phenol (1 to 10 mol), and more preferably a PO and EO adduct of styrenated phenol. The aromatic nonionic surfactant (B1) may be used alone or in combination of two or more.

[0048] From the viewpoint of the fuzz-inhibiting effect, the aromatic nonionic surfactant (B1) preferably has an HLB (Hydrophile-Lipophile Balance) value of 11 to 14. The HLB value of the aromatic nonionic surfactant (B1) is more preferably 11.5 to 13.7.

[0049] In the present invention, the HLB value is a numerical value indicating the balance between hydrophilicity and lipophilicity, and in the case of a single compound, is calculated by the following formula (1) (see "Synthesis and Application of Surfactants", page 501, published by Maki Shoten in 1957; "Introduction to Surfactants", pages 212-213, published by Sanyo Chemical Industries, Ltd. in 2007, etc.).

[0050] HLB value = 10 × (inorganicity / organicity) (1)

[0051] In formula (1), "inorganicity / organicity" represents the ratio of the inorganic value to the organic value of the compound, and this ratio can be calculated from the values ​​described in the above-mentioned literature.

[0052] Regarding the organic and inorganic values, the organic value is set to 20 per carbon atom, and the inorganic value is calculated using the values ​​in the table described on page 213 of the aforementioned "Introduction to Surfactants" (the "numerical value" in the inorganic group, or the "inorganic" numerical value in the organic and inorganic group). As a calculation example,

[0053] -CH3 group: organic value 20, inorganic value 0,

[0054] -CH2- group: organic value 20, inorganic value 0,

[0055] =CH2 group: organic value 20, inorganic value 1,

[0056] =CH- group: organic value 20, inorganic value 1,

[0057] Benzene ring: organic value 120, inorganic value 15,

[0058] -O- group: inorganic value 20,

[0059] -COO-: organic value 20, inorganic value 60,

[0060] -OH group: inorganic value 100,

[0061] -COOH group: organic value 20, inorganic value 150

[0062] In addition, in the calculation of the HLB value, the organic value and inorganic value shown below were used for the following configuration.

[0063] COO - M + : Organic value 20, Inorganic value 400 (It should be noted that "M + "COO - " counter ion, representing a metal cation or an ammonium cation)

[0064] Si atom: organic value 0, inorganic value 0

[0065] The HLB value of the aromatic nonionic surfactant (B1) can be adjusted by adjusting the type and amount of the surfactant used. When the aromatic nonionic surfactant (B1) contains two or more surfactants, its HLB value can be calculated by taking a weighted average. For example, when the aromatic nonionic surfactant (B1) contains M1 parts by weight of an aromatic nonionic surfactant (B11) having an HLB value of h1 and M2 parts by weight of an aromatic nonionic surfactant (B12) having an HLB value of h2, the HLB value of the aromatic nonionic surfactant (B1) can be calculated using the following formula.

[0066] HLB value of aromatic nonionic surfactant (B1) = (h1×M1+h2×M2) / (M1+M2)

[0067] From the viewpoint of the fuzz suppressing effect, the content of the aromatic nonionic surfactant (B1) in the fiber sizing composition of the present invention is preferably 1 to 20% by weight, more preferably 5 to 15% by weight, based on the weight of the nonvolatile components contained in the fiber sizing composition.

[0068] <Fiber Sizing Composition>

[0069] The fiber sizing composition of the present invention comprises a novolac-type epoxy resin (A1) and an aromatic nonionic surfactant (B1).

[0070] According to the present invention, by containing the novolac-type epoxy resin (A1) and the aromatic nonionic surfactant (B1) having the above-mentioned properties, a fiber sizing composition having excellent fuzz suppression and sizing properties can be provided. If the novolac-type epoxy resin (A1) is not included, the sizing properties may be insufficient, and if the aromatic nonionic surfactant (B1) is not included, the fuzz suppression effect may be insufficient.

[0071] The fiber sizing composition preferably contains 20 to 90 wt % of a novolac-type epoxy resin (A1) and 1 to 20 wt % of an aromatic nonionic surfactant (B1), and more preferably contains 30 to 85 wt % of a novolac-type epoxy resin (A1) and 5 to 15 wt % of an aromatic nonionic surfactant (B1), based on the weight of the non-volatile components contained in the fiber sizing composition.

[0072] <Aliphatic nonionic surfactant (B2)>

[0073] The fiber sizing composition of the present invention may further contain an aliphatic nonionic surfactant (B2) as a component in addition to the novolac epoxy resin (A1) and the aromatic nonionic surfactant (B1). Inclusion of the aliphatic nonionic surfactant (B2) can further enhance the fuzz suppression effect.

[0074] Examples of the aliphatic nonionic surfactant (B2) include AO adducts of aliphatic monohydric alcohols having 8 to 18 carbon atoms, AO adducts of higher fatty acids (having 12 to 24 carbon atoms), products obtained by reacting polyalkylene glycols (molecular weight 150 to Mw 6,000) obtained by adding AO (excluding EO) to diols with higher fatty acids, products obtained by adding AO (excluding EO) to esters obtained by reacting polyols (divalent or higher polyols such as ethylene glycol, propylene glycol, glycerin, and sorbitan) with higher fatty acids (molecular weight 250 to Mw 30,000), and polyol (3 to 60 carbon atoms) type nonionic surfactants [such as fatty acid (3 to 60 carbon atoms) esters of divalent or higher polyols]. The aliphatic nonionic surfactant (B2) may be used alone or in combination of two or more.

[0075] As the aliphatic nonionic surfactant (B2), from the viewpoint of suppressing linting, AO adducts of aliphatic monohydric alcohols having 8 to 18 carbon atoms are preferred, and aliphatic alkylene oxide adducts represented by the following general formula (2) (hereinafter also referred to as "compounds of general formula (2)") are more preferred.

[0076] R 1 O(AO) m H(2)

[0077] (R in general formula (2) 1 is an aliphatic hydrocarbon group having 8 to 11 carbon atoms and having 3 or more methyl groups. AO is an alkyleneoxy group having 2 to 4 carbon atoms. m represents the average number of moles of AO added and is 1 to 10. From the viewpoint of further suppressing fuzzing of the fiber bundle, R 1 The number of carbon atoms is preferably 9 or more.

[0078] The aliphatic hydrocarbon group having 8 to 11 carbon atoms may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. Examples of the aliphatic hydrocarbon group having 8 to 11 carbon atoms include an aliphatic hydrocarbon group having 3 methyl groups, an aliphatic hydrocarbon group having 4 methyl groups, and an aliphatic hydrocarbon group having 5 or more methyl groups.

[0079] The "methyl" in the expression "aliphatic hydrocarbon group having three methyl groups" refers to the -CH3 contained in the aliphatic hydrocarbon group. For example, 1-ethylbutyl [CH3(CH2)2(CH3CH2)CH-] has -CH3 at the end of each ethyl group and butyl group, and therefore has a total of two methyl groups.

[0080] In all the compounds of the general formula (2) contained in the fiber sizing composition of the present invention, R 1 The number of methyl groups in is preferably 3.5 or more per molecule of the compound of general formula (2). If it is 3.5 or more, the fuzzing of the fiber bundle can be further suppressed when the fiber sizing composition is used. In addition, the impregnation of the fiber sizing composition into the matrix resin can be improved. The number of R per molecule of the compound of general formula (2) is preferably 3.5 or more. If it is 3.5 or more, the fuzzing of the fiber bundle can be further suppressed when the fiber sizing composition is used. In addition, the impregnation of the fiber sizing composition into the matrix resin can be improved. 1 The number of methyl groups in is preferably 5 or less. 1 The number of methyl groups in is sometimes a decimal.

[0081] The R 1 The number of methyl groups in the compound of general formula (2) can be determined by, for example, adjusting the raw material alcohol (R 1 -OH) 1 It was calculated by H-NMR measurement and gas chromatography analysis.

[0082] The method for producing the compound of general formula (2) is not particularly limited, and it can be produced, for example, by the method described in the Production Examples of this application. Commercially available products may also be used.

[0083] (AO) in the general formula (2) is an alkyleneoxy group (oxyalkylene group) having 2 to 4 carbon atoms, specifically, ethyleneoxy, 1,2- or 1,3-propyleneoxy, and 1,2-, 1,3-, 2,3-, or 1,4-butyleneoxy. Among them, ethyleneoxy is preferred. When the compound of the general formula (2) has two or more (m is 2 or more) (AO), the m (AO) groups may be the same or different.

[0084] Specific examples of the compound of general formula (2) include EO adducts, PO adducts, BO adducts, random adducts of EO and PO, EO-PO block adducts, PO-EO block adducts, random adducts of EO and BO, EO-BO block adducts, and BO-EO block adducts of aliphatic alcohols having 8 to 11 carbon atoms. Among them, from the viewpoint of suppressing fuzzing, EO adducts of aliphatic alcohols having 8 to 11 carbon atoms are preferred, and EO adducts of decanol (having three or more methyl groups) are more preferred.

[0085] When the fiber sizing composition of the present invention contains an aliphatic nonionic surfactant (B2), from the viewpoint of the fuzz-inhibiting effect, the content thereof is preferably 1 to 10% by weight or more, more preferably 2 to 8% by weight or more, based on the weight of the nonvolatile components in the fiber sizing composition.

[0086] <Polyether Compound (C)>

[0087] The fiber sizing composition of the present invention may further contain a polyether compound (C).

[0088] Examples of the polyether-containing compound (C) include compounds having one or more polyoxyalkylene groups in one molecule, and examples include polyether-containing compounds having one or more polyoxyethylene groups in one molecule, wherein the number of oxyethylene groups (ethyleneoxy groups) per one polyoxyethylene group is 2 to 60.

[0089] Examples of the polyether-containing compound (C) include ester compounds [compounds having an ester group formed by reacting a diol (c2) with a dicarboxylic acid or its anhydride (c1), etc.], urethane compounds [compounds formed by reacting a polyol with a diisocyanate, etc.], and polyether diols. Among these, ester compounds are preferred.

[0090] As the ester compound, a compound having an ester group obtained by reacting a diol (c2) with a dicarboxylic acid or its anhydride (c1) is preferred. As the ester compound, compounds described in JP-A-2022-169361 can be used.

[0091] Examples of the dicarboxylic acid or its anhydride (c1) include aliphatic dicarboxylic acids (such as fumaric acid), aromatic dicarboxylic acids, and their anhydrides. Among these, aromatic dicarboxylic acids and their anhydrides are preferred. The dicarboxylic acid or its anhydride (c1) may be used alone or in combination of two or more.

[0092] Examples of the aromatic dicarboxylic acid include aromatic dicarboxylic acids having 8 to 14 carbon atoms (terephthalic acid, isophthalic acid, phthalic acid, phenylmalonic acid, phenylsuccinic acid, β-phenylglutaric acid, α-phenyladipic acid, β-phenyladipic acid, 2,2′-biphenyldicarboxylic acid, 4,4′-biphenyldicarboxylic acid, naphthalene dicarboxylic acid, sodium 5-sulfoisophthalate, potassium 5-sulfoisophthalate, and the like).

[0093] Among them, terephthalic acid, isophthalic acid, and phthalic acid are more preferred from the viewpoint of sizing properties.

[0094] The diol (c2) preferably contains a diol (c21) having one or more polyoxyethylene groups composed of two or more consecutive oxyethylene groups in one molecule, wherein the number of oxyethylene groups per one polyoxyethylene group is preferably 2 to 60.

[0095] Examples of the diol (c21) include polyethylene glycols obtained by adding 1 to 59 mol of ethylene oxide (EO) to ethylene glycol (an example of a compound having one polyoxyethylene group), compounds obtained by adding 4 to 120 mol of EO to a compound having two hydroxyl groups (excluding ethylene glycol), and compounds obtained by adding 4 to 120 mol of EO to a primary amine (these are examples of compounds having two polyoxyethylene groups in one molecule and the number of oxyethylene groups per one polyoxyethylene group is 2 to 60).

[0096] Examples of compounds having two hydroxyl groups include aliphatic alkanediols, alicyclic diols, and diphenols containing aromatic rings. Among them, diphenols containing aromatic rings are preferred. Examples of diphenols containing aromatic rings include bisphenol A, bisphenol S, and hydroquinone.

[0097] The diol (c21) is preferably at least one diol selected from the group consisting of 4 to 120 mol EO adducts of aromatic ring-containing dihydric phenols, and more preferably 4 to 120 mol EO adducts of bisphenol A (the number of oxyethylene groups per polyoxyethylene group is 2 to 60).

[0098] The diol (c2) may contain other diols (c22) in addition to the above diols (c21). Examples of other diols (c22) include EO 2-mole adducts of aromatic ring-containing dihydric phenols, ethylene glycol, and propylene glycol.

[0099] The weight of the diol (c21) is preferably 35 to 100% by weight, more preferably 40 to 100% by weight, and further preferably 45 to 90% by weight, based on the weight of the diol (c2).

[0100] An example of a method for producing an ester compound is a method in which a dicarboxylic acid or its anhydride (c1) and a diol (c2) are added at a predetermined molar ratio, and water is distilled off under stirring at a reaction temperature of 100 to 250°C and a pressure of -0.1 to 1.2 MPa. In the method for producing an ester compound, a catalyst is preferably added in an amount of 0.05 to 0.5% by weight based on the weight of the ester compound. Examples of catalysts include p-toluenesulfonic acid, dibutyltin oxide, tetraisopropoxytitanate, and potassium titanium oxalate. From the perspectives of reactivity and environmental impact, tetraisopropoxytitanate and potassium titanium oxalate are preferred, and potassium titanium oxalate is more preferred.

[0101] Examples of the urethane compounds and polyether diols that can be used as the polyether compound (C) include those described in JP-A-2022-169361.

[0102] The number average molecular weight of the polyether-containing compound (C) is preferably 1,000 to 10,000, more preferably 1,000 to 9,000. The number average molecular weight is a value measured by gel permeation chromatography.

[0103] When the fiber sizing composition of the present invention contains a polyether compound (C), from the perspective of fiber opening properties, the content of the polyether compound (C) is preferably 5% by weight or more, more preferably 10% by weight or more, based on the weight of the nonvolatile components in the fiber sizing composition. Furthermore, from the perspective of sizing properties, the content of the polyether compound (C) is preferably 70% by weight or less, more preferably 50% by weight or less, based on the weight of the nonvolatile components in the fiber sizing composition. The content of the polyether compound (C) is preferably 5 to 70% by weight, more preferably 10 to 50% by weight, based on the weight of the nonvolatile components in the fiber sizing composition.

[0104] The fiber sizing composition of the present invention may further contain other components [resin (D) other than the novolac-type epoxy resin (A1), surfactant (E) other than the aromatic nonionic surfactant (B1) and the aliphatic nonionic surfactant (B2), and additives (F)] as components other than the above.

[0105] Examples of the resin (D) include epoxy resins other than the novolac epoxy resin (A1), vinyl ester resins, and unsaturated polyester resins. As these resins, resins described in Japanese Patent Application Laid-Open No. 2022-169361 can be used.

[0106] Examples of the surfactant (E) include cationic surfactants, anionic surfactants, and amphoteric surfactants.

[0107] Examples of the cationic surfactant include quaternary ammonium salts [tetraalkyl (carbon number 1 to 30) ammonium salts (lauryltrimethylammonium chloride, didecyldimethylammonium chloride, stearyltrimethylammonium bromide, etc.); polyoxyalkylene (carbon number 2 to 4) trialkyl (carbon number 1 to 30) ammonium salts (polyoxyethylenetrimethylammonium chloride, etc.)] and amine salts [inorganic acid or organic acid salts of aliphatic higher (carbon number 12 to 60) amines (laurylamine, stearylamine, etc.); and inorganic acid or organic acid salts of EO adducts of aliphatic amines (carbon number 1 to 30).

[0108] Examples of the anionic surfactant include carboxylic acids (saturated or unsaturated fatty acids having 8 to 22 carbon atoms) or salts thereof (such as sodium, potassium, ammonium, and alkanolamine salts), higher alcohol (8 to 18 carbon atoms) sulfates, higher alkyl ether sulfates [sulfates of EO (1 to 10 mol) adducts of aliphatic alcohols having 8 to 18 carbon atoms, sulfates of AO adducts of alkylphenols, and sulfates of AO adducts of arylalkylphenols], sulfonates [alkyl (1 to 20 carbon atoms) benzenesulfonates, alkyl (1 to 20 carbon atoms) naphthalenesulfonates, dialkyl sulfosuccinates (1 to 20 carbon atoms), and α-olefin (12 to 18 carbon atoms) sulfonates], and phosphates [phosphates of higher alcohol (8 to 60 carbon atoms) and phosphates of higher alcohol (8 to 60 carbon atoms) EO adducts].

[0109] Examples of the amphoteric surfactant include amino acid-type amphoteric surfactants [such as sodium propionate of higher alkylamines (having 12 to 18 carbon atoms)], betaine-type amphoteric surfactants [such as alkyl (having 12 to 18 carbon atoms) dimethyl betaine], sulfate-type amphoteric surfactants [such as sodium salts of sulfate esters of higher alkylamines (having 8 to 18 carbon atoms) and sodium salts of hydroxyethylimidazoline sulfate], sulfonate-type amphoteric surfactants [such as pentadecylsulfotaurine and imidazolinesulfonic acid], and phosphate-type amphoteric surfactants [such as phosphate amine salts of glycerol higher fatty acid (having 8 to 22 carbon atoms) esters].

[0110] As the surfactant (E), anionic surfactants are preferred, and sulfates of AO adducts of alkylphenols, sulfates of AO adducts of arylalkylphenols, and mixtures thereof are more preferred.

[0111] Examples of the additive (F) include smoothing agents, antiseptics, and antioxidants.

[0112] Examples of lubricants include waxes (polyethylene, polypropylene, oxidized polyethylene, oxidized polypropylene, modified polyethylene, and modified polypropylene), higher fatty acid alkyl (carbon number 1 to 24) esters (methyl stearate, ethyl stearate, propyl stearate, butyl stearate, octyl stearate, and stearyl stearate), higher fatty acids (myristic acid, palmitic acid, and stearic acid), natural oils (coconut oil, butter, olive oil, and rapeseed oil), and liquid paraffin.

[0113] Examples of the preservative include benzoic acids, salicylates, sorbic acids, quaternary ammonium salts, and imidazoles.

[0114] Examples of the antioxidant include phenols (such as 2,6-di-tert-butyl-p-cresol), thiodipropionates (such as dilauryl 3,3′-thiodipropionate), and phosphites (such as triphenyl phosphite).

[0115] The total content of the components other than the novolac-type epoxy resin (A1), the aromatic nonionic surfactant (B1), the aliphatic nonionic surfactant (B2) and the polyether-containing compound (C) is preferably 0 to 60% by weight, more preferably 0 to 20% by weight, based on the weight of the nonvolatile components contained in the fiber sizing composition.

[0116] The method for producing the fiber sizing composition of the present invention is not particularly limited. For example, a method can be exemplified by placing a novolac-type epoxy resin (A1), an aromatic nonionic surfactant (B1), and, if necessary, an aliphatic nonionic surfactant (B2), a polyether-containing compound (C), a resin (D), a surfactant (E), and an additive (F) in a mixing vessel and stirring the mixture preferably at 20 to 150° C., more preferably at 50 to 120° C., until the mixture is uniform. The order in which the components constituting the composition are added is not particularly limited.

[0117] The fiber sizing composition of the present invention preferably has an epoxy group concentration of 1.5 meq / g or greater in the nonvolatile component. By setting the epoxy group concentration to 1.5 meq / g or greater, a fiber sizing composition having excellent sizing properties can be provided. If the epoxy group concentration is less than 1.5 meq / g, sizing properties may be insufficient. From the perspective of sizing properties, the epoxy group concentration is preferably 1.6 meq / g or greater, and more preferably 1.7 meq / g or greater.

[0118] The epoxy group concentration can be adjusted by adjusting the type and amount of the novolac-type epoxy resin (A1).

[0119] In the present invention, the epoxy group concentration can be determined from the epoxy equivalent measured by the method specified in JISK 7236.

[0120] It should be noted that when the fiber sizing composition of the present invention contains a novolac-type epoxy resin (A1), an aromatic nonionic surfactant (B1) and a polyether-containing compound (C), from an industrial viewpoint, the respective contents are preferably 30 to 60% by weight of the novolac-type epoxy resin (A1), 5 to 15% by weight of the aromatic nonionic surfactant (B1), and 30 to 60% by weight of the polyether-containing compound (C), based on the total weight of the novolac-type epoxy resin (A1), the aromatic nonionic surfactant (B1), and the polyether-containing compound (C). More preferably, the novolac-type epoxy resin (A1), the aromatic nonionic surfactant (B1), and the polyether-containing compound (C) are 35 to 55% by weight.

[0121] In addition, when the fiber sizing composition contains a novolac-type epoxy resin (A1), an aromatic nonionic surfactant (B1), a polyether-containing compound (C) and an aliphatic nonionic surfactant (B2), from an industrial viewpoint, the content of the aliphatic nonionic surfactant (B2) is preferably 3 to 10% by weight based on the total weight of the novolac-type epoxy resin (A1), the aromatic nonionic surfactant (B1) and the polyether-containing compound (C).

[0122] The fiber sizing composition of the present invention can be used by being dissolved or dispersed in water and / or an organic solvent. Hereinafter, water and an organic solvent are also referred to as "solvents."

[0123] By dissolving or dispersing the fiber sizing composition of the present invention in a solvent, it is easy to adjust the amount of the fiber sizing composition attached to the fiber bundle to an appropriate amount.

[0124] A solution or dispersion (fiber sizing solution, fiber sizing dispersion) obtained by dissolving or dispersing the fiber sizing composition of the present invention in a solvent also falls within the scope of the present invention.

[0125] Examples of the organic solvent include monohydric alcohols having 1 to 4 carbon atoms (such as methanol, ethanol, and isopropanol), ketones having 3 to 6 carbon atoms (such as acetone, methyl ethyl ketone, and methyl isobutyl ketone), diols having 2 to 6 carbon atoms (such as ethylene glycol, propylene glycol, diethylene glycol, and triethylene glycol), their mono-lower alkyl (alkyl group having 1 to 4 carbon atoms) ethers, dimethylformamide, aromatic hydrocarbons (such as toluene and xylene), and alkyl acetates having 3 to 5 carbon atoms (such as methyl acetate and ethyl acetate).

[0126] The above solvents may be used alone or in combination of two or more. Among the above solvents, water and a mixed solvent of a water-miscible organic solvent (an organic solvent that can be uniformly mixed with water at a volume ratio of 1:1 at 25°C) and water are preferred from the viewpoint of safety against fire, etc., and water is more preferred.

[0127] Examples of fibers to which the fiber sizing composition of the present invention can be applied include inorganic fibers (carbon fibers, glass fibers, ceramic fibers, metal fibers, mineral fibers, and slag fibers) and organic fibers (aramid fibers). Among these, carbon fibers are preferred from the perspective of the strength of the fiber sizing composition and the composite material formed using the fibers.

[0128] <Fiber bundle>

[0129] The fiber bundle of the present invention is a fiber bundle obtained by treating at least one fiber selected from the group consisting of carbon fibers, glass fibers, aramid fibers, ceramic fibers, metal fibers, mineral fibers, and slag fibers with the fiber sizing composition of the present invention.

[0130] Examples of methods for producing the fiber bundle of the present invention include a method in which at least one fiber selected from the group consisting of carbon fibers, glass fibers, aramid fibers, ceramic fibers, metal fibers, mineral fibers, and slag fibers is treated with the fiber sizing composition or fiber sizing solution of the present invention to obtain a fiber bundle.

[0131] The fiber bundle of the present invention preferably has 3,000 to 50,000 fibers bundled together. The fiber sizing composition or fiber sizing solution of the present invention can sufficiently suppress fuzzing even when the fiber bundle has a large number of fibers (20,000 or more).

[0132] Examples of the fiber treatment method include a spraying method and an immersion method.

[0133] The amount of the fiber sizing composition applied to the fiber is preferably 0.05 to 5% by weight, more preferably 0.2 to 2.5% by weight, based on the weight of the fiber. When the amount of the fiber sizing composition applied is within this range, excellent sizing properties are achieved.

[0134] <Fiber products>

[0135] The fiber products of the present invention include the fiber bundles of the present invention. The fiber products include products obtained by processing the fiber bundles of the present invention into fiber products, including woven fabrics, knitted fabrics, non-woven fabrics (felt, mat, paper, etc.), chopped fibers, and milled fibers.

[0136] <Composite Materials>

[0137] The composite material of the present invention comprises the fiber bundle of the present invention and / or the fiber product of the present invention, and a matrix resin.

[0138] Examples of the matrix resin include thermoplastic resins (polypropylene, polyamide, polyethylene terephthalate, polycarbonate, and polyphenylene sulfide, etc.) and thermosetting resins [resins similar to epoxy resins, unsaturated polyester resins, and vinyl ester resins that can be used as resin (D), as well as phenolic resins (resins described in Japanese Patent No. 3723462, etc.)].

[0139] The composite material of the present invention may contain a catalyst as needed.

[0140] When the matrix resin is an epoxy resin that can be used as the resin (D), examples of the catalyst include known epoxy resin curing catalysts and curing accelerators (such as those described in Japanese Patent Application Laid-Open No. 2005-213337). Furthermore, when the matrix resin is the unsaturated polyester resin or vinyl ester resin described above, examples of the catalyst include peroxides (such as benzoyl peroxide, t-butyl perbenzoate, t-butylcumyl peroxide, methyl ethyl ketone peroxide, 1,1-di(t-butylperoxy)butane, and di(4-t-butylcyclohexyl) peroxydicarbonate) and azo compounds (such as azobisisovaleronitrile).

[0141] In the composite material of the present invention, from the viewpoint of the strength of the composite molded body, 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, and particularly preferably 30 / 70 to 60 / 40.

[0142] When the composite material contains a catalyst, the content of the catalyst is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, and particularly preferably 1 to 3 parts by weight relative to 100 parts by weight of the matrix resin, from the viewpoint of the strength of the composite material molded body.

[0143] The composite material of the present invention includes prepregs, molded bodies, and the like.

[0144] Prepregs can be produced, for example, by impregnating a fiber bundle and / or fiber product with a heat-melted matrix resin (preferably at a melting temperature of 60 to 350°C) or a matrix resin diluted with a solvent (such as acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, and ethyl acetate). When a solvent is used, it is preferably dried to remove the solvent.

[0145] When the matrix resin is a thermoplastic resin, a prepreg can be formed into a molded body by heating and molding and then curing it at room temperature.

[0146] When the matrix resin is a thermosetting resin, the prepreg can be heated, molded, and cured to produce a molded body.

[0147] These resins do not need to be completely cured, but are preferably cured to the extent that the molded body can maintain its shape. After molding, they can be further heated to completely cure.

[0148] The method of heat molding is not particularly limited, and examples include: fiber winding molding (a method of winding and heat molding while applying tension to a rotating mandrel), press molding (a method of stacking prepreg sheets and heat molding), autoclave method (a method of pressing prepreg sheets against a mold with pressure and heat molding), and a method of mixing chopped fibers or ground fibers with a matrix resin and injection molding.

[0149] [Example]

[0150] The present invention will be further described below with reference to Examples, but the present invention is not limited to these Examples. Unless otherwise specified, "%" represents % by weight and "parts" represents parts by weight.

[0151] <Production Example 1: Production of 80 mol EO adduct of bisphenol A (c21-3)>

[0152] In a pressure-resistant reaction vessel equipped with a stirrer, heating and cooling devices, and a dropping bottle, 228 parts (1 mol) of bisphenol A, 1000 parts of toluene, and 2 parts of potassium hydroxide were placed, and the pressure was maintained at -0.08 MPa. The temperature was raised to 130°C, and while the pressure was maintained at below 0.5 MPaG, 3520 parts (80 mol) of EO were added dropwise over 6 hours. The mixture was then aged at 130°C for 3 hours. Subsequently, the mixture was cooled to 100°C, and 30 parts of the adsorption treatment agent "Kyoward 600" (manufactured by Kyowa Chemical Industry Co., Ltd.) were added. After stirring at 100°C for 1 hour, the adsorption treatment agent was filtered to obtain an 80 mol adduct of bisphenol A with EO (C21-3). This adduct (C21-3) is a diol having two polyoxyethylene groups, with 40 oxyethylene groups per polyoxyethylene group.

[0153] <Production Example 2: Production of 40 mol EO adduct of bisphenol A (c21-2)>

[0154] In Production Example 1, except that 1000 parts of toluene was replaced with 400 parts of toluene, and 3520 parts of EO was replaced with 1760 parts (40 parts by mole), a 40 mol adduct of bisphenol A with EO (C21-2) was obtained in the same manner as in Production Example 1. The adduct (C21-2) is a diol having two polyoxyethylene groups, with the number of oxyethylene groups per polyoxyethylene group being 20.

[0155] <Production Example 3: Production of 120 mol EO adduct of bisphenol A (c21-4)>

[0156] In Production Example 1, except that 1000 parts of toluene was replaced with 1500 parts of toluene, and 3520 parts of EO was replaced with 5280 parts (120 parts by mole), a 120 mol adduct of bisphenol A with EO (C21-4) was obtained in the same manner as in Production Example 1. The adduct (C21-4) is a diol having two polyoxyethylene groups, with the number of oxyethylene groups per polyoxyethylene group being 60.

[0157] <Production Example 4: Production of Polyether-Containing Compound (C-1)>

[0158] 1580 parts (5 mol parts) of a 2-mol EO adduct of bisphenol A (the number of oxyethylene groups is 1 per hydroxyl group) "NEWPOL BPE-20" [manufactured by Sanyo Chemical Industries, Ltd.] (C22-1), 1590 parts (0.4 mol parts) of the adduct produced in Production Example 1 (C21-3), 996 parts (6 mol parts) of terephthalic acid (C1-1), and 3 parts of potassium titanium oxalate were reacted in a glass reaction vessel at 230°C under reduced pressure to 0.001 MPa while distilling off water for 15 hours to obtain a polyether-containing compound (C-1) having a number average molecular weight (Mn) of 1850. This compound is a polyether-containing compound (ester compound) having an ester group.

[0159] <Production Examples 5 to 9: Production of Polyether-Containing Compounds (C-2) to (C-6)>

[0160] In Production Example 4, each polyether-containing compound (C) was obtained in the same manner as in Production Example 4 except that the raw materials (parts) were used as shown in Table 1. The results are shown in Table 1.

[0161] [Table 1]

[0162]

[0163] In Table 1, the raw materials used are as follows.

[0164] (c1-1): Terephthalic acid

[0165] (c1-2): Fumaric acid

[0166] (c21-1): 4-mol EO adduct of bisphenol A (the number of oxyethylene groups per one polyoxyethylene group is 2), trade name: "NEWPOL BPE-40", manufactured by Sanyo Chemical Industries, Ltd.

[0167] (c21-2): EO 40 mol adduct of bisphenol A produced in Production Example 2

[0168] (c21-3): EO 80 mol adduct of bisphenol A produced in Production Example 1

[0169] (c21-4): 120 mol EO adduct of bisphenol A produced in Production Example 3

[0170] (c21-5): Polyethylene glycol (Mn: 2,000) (the number of oxyethylene groups per polyoxyethylene group is 45)

[0171] (c22-1): Bisphenol A EO 2-mol adduct [the number of ethylene oxide per (poly)ethylene oxide is 1, trade name: "NEWPOL BPE-20", manufactured by Sanyo Chemical Industries, Ltd.]

[0172] (c22-2): Ethylene glycol

[0173] <Production Example 10: Production of 6-mol EO Addition Product of Decanol (B2-1)>

[0174] A pressure-resistant reaction vessel equipped with a stirrer, heating and cooling device, and a dropping bottle was charged with 158 parts (1 mol) of "decanol" [manufactured by KH Neochem Co., Ltd.] and 0.5 parts (0.009 mol) of potassium hydroxide. The atmosphere was purged with nitrogen, sealed, heated to 70°C, and dehydrated under reduced pressure for 1 hour. The temperature was then raised to 160°C, and while maintaining the pressure at 0.5 MPaG or less, 264 parts (6 mol) of EO were added dropwise over 5 hours. The mixture was then aged at 160°C for 2 hours. Subsequently, the mixture was cooled to 70°C, and 10 parts of an adsorption treatment agent, "Kyoward 600" [manufactured by Kyowa Chemical Industry Co., Ltd.], were added. The mixture was stirred at 70°C for 1 hour, and the adsorption treatment agent was filtered to obtain a 6-mol EO adduct of decanol (B2-1).

[0175] pass 1 The raw material compound used in this production example, decanol manufactured by KH Neochem Co., Ltd., was analyzed by H-NMR and gas chromatography to confirm that it was an alcohol having a hydroxyl group bonded to a decyl group (an aliphatic hydrocarbon group having 10 carbon atoms). 1 The number of methyl groups in is 3.5.

[0176] Therefore, the EO 6-mol adduct (B2-1) of decanol obtained in this production example is a compound represented by the above general formula (2), wherein R 1 is decyl (R per molecule of compound 1 The number of methyl groups is 3.5), (AO) is ethyleneoxy, and m is 6.

[0177] <Examples 1 to 10, Comparative Examples 1 to 5>

[0178] The materials of the types and amounts listed in Table 2 [a novolac-type epoxy resin (A1) or a bisphenol A-type epoxy resin (A'), an aromatic nonionic surfactant (B1), a polyether-containing compound (C), and an aliphatic nonionic surfactant (B2)] were placed in a reaction vessel equipped with a stirring device, a heating and cooling device, a thermometer, and a dropping funnel, and the mixture was stirred while heating for 5 minutes to obtain a fiber sizing composition.

[0179] Next, water was added dropwise to the fiber sizing composition from a dropping funnel over a period of 1 hour to prepare fiber sizing solutions (X1) to (X10), (X'1) to (X'3), and (X'5), which were dispersions of the fiber sizing composition having a solid content concentration of 40%. Here, the solid content refers to the residue obtained by heating and drying 1 g of a sample in a glass petri dish at 130°C for 45 minutes in a circulating air dryer without a cover. The sizing properties, fuzzing, and strength of the molded products of the carbon fiber bundles produced using the above-mentioned fiber sizing solutions (X1) to (X10), (X'1) to (X'3), and (X'5) were evaluated by the following methods. The results are shown in Table 2. It should be noted that in Comparative Example 4, since the composition was not dispersed and a fiber sizing solution was not obtained, the sizing properties, fuzzing, and strength of the molded product could not be evaluated (described as "unable to measure" in Table 2).

[0180] The materials used in the production of the fiber sizing solution in Examples and Comparative Examples are as follows.

[0181] <Novolac type epoxy resin (A1)>

[0182] (A1-1): Cresol novolac-type epoxy resin [manufactured by Nippon Steel Chemicals Co., Ltd., "YDCN-700-7," viscosity at 60°C: 30,000 Pa·s, epoxy group concentration: 5.00 meq / g]

[0183] (A1-2): Phenol novolac-type epoxy resin [manufactured by DIC Corporation, "EPICLON N-740", viscosity at 60°C: 13 Pa·s, epoxy group concentration: 5.49 meq / g]

[0184] <Bisphenol A type epoxy resin (A')>

[0185] (A'-1): Bisphenol A epoxy resin [manufactured by DIC Corporation, "EPICLON 1050", viscosity at 60°C: 4000 Pa·s, epoxy group concentration: 2.11 meq / g]

[0186] (A'-2): Bisphenol A epoxy resin [manufactured by Mitsubishi Chemical Corporation, "jER828," viscosity at 60°C: 0.2 Pa·s, epoxy group concentration: 5.29 meq / g]

[0187] <Aromatic nonionic surfactant (B1)>

[0188] (B1-1): Propylene oxide-ethylene oxide adduct of styrenated phenol [trade name: "Soprophor 796 / P", manufactured by Solvay Nikka Co., Ltd., HLB value 13.7, 3 mol of styrene per 1 mol of phenol]

[0189] (B1-2): Propylene oxide-ethylene oxide adduct of styrenated phenol [trade name: "Soprophor TSP / 724", manufactured by Solvay Nikka Co., Ltd., HLB value: 11.9]

[0190] <Polyether Compound (C)>

[0191] (C-1): The polyether-containing compound (ester compound) produced in Production Example 4

[0192] (C-2): The polyether-containing compound (ester compound) produced in Production Example 5

[0193] (C-3): The polyether-containing compound (ester compound) produced in Production Example 6

[0194] (C-4): The polyether-containing compound (ester compound) produced in Production Example 7

[0195] (C-5): The polyether-containing compound (ester compound) produced in Production Example 8

[0196] (C-6): The polyether-containing compound (ester compound) produced in Production Example 9

[0197] <Aliphatic nonionic surfactant (B2)>

[0198] (B2-1): EO 6 mol adduct of decanol produced in Production Example 10

[0199] [Measurement of resin viscosity at 60°C]

[0200] The viscosities of the novolac-type epoxy resin (A1) and the bisphenol A-type epoxy resin (A') at 60° C. were measured using a viscoelasticity measuring apparatus [MCR302 manufactured by Anton Paar Japan Co., Ltd.] under the following conditions.

[0201] Measurement mode: Shear mode

[0202] Conditions: strain 1%, frequency 1 Hz

[0203] Plate: Parallel plate (25mm diameter)

[0204] Distance between boards: 1mm

[0205] [Evaluation of emulsion stability]

[0206] The median particle size of the fiber sizing solutions in the Examples and Comparative Examples was measured using a laser diffraction / scattering particle size distribution analyzer LA-950 manufactured by Horiba, Ltd., and evaluated based on the following evaluation criteria. The results are shown in Table 2. The refractive index conditions were set to 1.470 (particles) and 1.333 (dispersion medium). A smaller median particle size is preferred.

[0207] <Evaluation Criteria>

[0208] ○: Median particle size is 0.150 μm or less

[0209] △: Median diameter exceeds 0.150 μm and is 0.200 μm or less

[0210] ×: Median particle size exceeds 0.200 μm or cannot be emulsified

[0211] [Evaluation of sizing properties, fuzzing, and molded body strength]

[0212] <Manufacturing of Carbon Fiber Bundles for Evaluation Tests>

[0213] Water was added to the fiber sizing solution obtained in each Example and Comparative Example (except Comparative Example 4) to a solids concentration of 1.5% to prepare a dispersion. Untreated carbon fibers (24,000 filaments) were then impregnated with the dispersion to allow the dispersion to penetrate. The carbon fibers were then removed from the dispersion and dried in hot air at 180°C for 3 minutes to produce a carbon fiber bundle. The carbon fiber bundle was prepared so that the amount of solids contained in the dispersion of the fiber sizing composition attached to the fibers (as a percentage of the weight of the carbon fibers before impregnation) was 1.5%. This carbon fiber bundle was then subjected to sizing and fuzz evaluation tests.

[0214] <Evaluation Test of Sizing Properties>

[0215] Using test carbon fiber bundles, sizing properties were evaluated according to JIS L1096:2010 8.21.1A (45° cantilever method). Specifically, the cantilever method was used to evaluate carbon fiber bundles obtained under the processing conditions specified in the JIS. A larger measured value (cm) indicates superior sizing properties. The sizing properties measured using this evaluation method are preferably 20 cm or greater, particularly 25 cm or greater. Values ​​below 19 cm may not sufficiently improve sizing properties.

[0216] <Evaluation test of fuzzing>

[0217] (1) Description of the evaluation device

[0218] like Figure 1 As shown, five stainless steel rods (1A, 1B, 1C, 1D, and 1E) with a smooth surface and a diameter of 10 mm, which were adjusted to a temperature of 25°C, were arranged in parallel with each other so that the horizontal intervals between adjacent stainless steel rods were 50 mm. Furthermore, carbon fiber bundles 4 were arranged so that they passed through the stainless steel rods 1A, 1B, 1C, 1D, and 1E in a zigzag pattern while in contact with them. The horizontal direction is the direction indicated by the arrow line XX' in the figure and is parallel to the horizontal plane HL.

[0219] It should be noted that the straight line connecting the centers of the stainless steel rods 1A, 1C, and 1E through which the first, third, and fifth carbon fiber bundles 4 pass, and the straight line connecting the centers of the stainless steel rods 1B and 1D through which the second and fourth carbon fiber bundles 4 pass, are arranged parallel to the horizontal plane. Furthermore, before and after the second to fourth stainless steel rods 1B and 1D pass through, the straight line in the direction of travel of the carbon fiber bundle before passing and the straight line in the direction of travel of the carbon fiber bundle after passing form an angle of 120 degrees (for example, the angle formed by the straight line parallel to the direction of travel of the carbon fiber bundle passing between the first stainless steel rod 1A and the second stainless steel rod 1B and the straight line parallel to the direction of travel of the carbon fiber bundle passing between the second stainless steel rod 1B and the third stainless steel rod 1C is 120 degrees).

[0220] The unwinding roller 2 and the winding roller 3 are provided so as to rotate in the directions of arrows drawn near the respective rollers.

[0221] (2) Determination of hair weight

[0222] The fuzz weight was measured using the carbon fiber bundle for testing according to the following procedure.

[0223] The carbon fiber bundle 4 is laid out in a zigzag pattern between stainless steel rods 1A, 1B, 1C, 1D, and 1E. After passing through stainless steel rod 1E, the bundle is sandwiched between two 10 cm x 10 cm square pieces of polyurethane foam, each loaded with a 1 kg weight, in the thickness direction (vertical direction in the figure) of the bundle 4, in an area immediately before being taken up by the take-up roller 3 (area 5A 10 cm upstream of the take-up starting point 3A of the take-up roller 3). In this example, the carbon fiber bundle is fed from the unwinding roller 2 to the take-up roller 3, so the "upstream side" refers to the upstream side in the feeding direction, i.e., the side toward the unwinding roller 2.

[0224] The tension unwinding from the unwinding roll 2 was set to 9.8 N (1 kgf), and the carbon fiber bundle 4 sandwiched between the polyurethane foam was wound onto the winding roll 3 at a speed of 1 m / min for 5 minutes. During this time, the weight of the fuzz attached to the two sheets of polyurethane foam was measured and evaluated based on the following evaluation criteria. The smaller the amount of fuzz, the more effectively it was suppressed.

[0225] <Evaluation Criteria>

[0226] ◎: The amount of fuzz is 0.5 mg or less

[0227] ○: The amount of fuzz is more than 0.5 mg and less than 2 mg

[0228] ×: The amount of fuzz exceeds 2 mg

[0229] <Evaluation Test of Molded Body Strength>

[0230] The carbon fiber bundles for the test were used and evaluated according to the following procedures.

[0231] (1) Preparation of test pieces

[0232] A carbon fiber bundle was placed in a mold to achieve a carbon fiber volume fraction (Vf) of 60%. A matrix resin (see the composition below) was poured in and vacuum degassing was performed while heating. After degassing, the mold was placed in a press and heated while applying pressure to cure the resin. A flat plate with a width of 6 mm and a thickness of 2.5 mm was prepared. This flat plate was then cut into 18 mm long pieces to serve as test pieces.

[0233] (Composition of the matrix resin loaded into the mold)

[0234] 100 parts by weight of bisphenol A epoxy resin (Ep828, manufactured by Japan Epoxy Resins Co., Ltd.)

[0235] 3 parts by weight of monoethylamine boron trifluoride (manufactured by Stella Chemifa Co., Ltd.)

[0236] (Molding conditions)

[0237] Degassing: vacuum (-0.08MPa or less), 70℃×4 hours

[0238] Molding: Pressing pressure (4.9MPa), 170℃×1 hour

[0239] Post-curing: 170℃×2 hours

[0240] (2) Measurement of molded body strength (CFRP strength)

[0241] The obtained test piece (molded article) was subjected to measurement of ILSS (interlaminar shear strength) in accordance with JIS K 7078. A larger measured value indicates a higher strength and a higher adhesion between the fiber and the matrix resin.

[0242] <Evaluation Criteria>

[0243] ◎: ILSS is 90 MPa or more

[0244] ○: ILSS is 80 MPa or more and less than 90 MPa

[0245] ×: ILSS less than 80 MPa

[0246]

[0247] As shown in Table 2, it was found that when the fiber sizing composition of the Examples was used, fuzzing could be suppressed and the sizing properties could be remarkably improved.

[0248] The fiber sizing agent solutions of the above-described examples and the fiber sizing agent compositions constituting the same are within the scope of the present invention. Therefore, it is clear that the present invention can provide a fiber sizing agent that suppresses fuzzing and has excellent sizing properties.

[0249] Description of Reference Numerals

[0250] 1A, 1B, 1C, 1D, 1E stainless steel bars

[0251] 2 unwinding rollers

[0252] 3 Winding roller

[0253] 3A Coiling start point

[0254] 4 carbon fiber bundles.

[0255] 5A is located 10 cm upstream of 3A

[0256] HL horizontal plane

Claims

1. A fiber sizing composition comprising a novolac epoxy resin (A1) and an aromatic nonionic surfactant (B1).

2. The fiber sizing composition according to claim 1, wherein The fiber sizing composition contains 20 to 90 wt% of a novolac epoxy resin (A1) and 1 to 20 wt% of an aromatic nonionic surfactant (B1), based on the weight of the nonvolatile components in the composition.

3. The fiber sizing composition according to claim 1, wherein The fiber sizing composition further comprises 5 to 70 wt% of a polyether compound (C) based on the weight of the non-volatile components contained in the fiber sizing composition.

4. The fiber sizing composition according to claim 3, wherein The polyether-containing compound (C) is a compound having an ester group obtained by reacting a diol (c2) with a dicarboxylic acid or its anhydride (c1).

5. The fiber sizing composition according to claim 4, wherein The dicarboxylic acid or its anhydride (c1) is an aromatic dicarboxylic acid or its anhydride.

6. The fiber sizing composition according to claim 4, wherein The diol (c2) includes a diol (c21) having one or more polyoxyethylene groups composed of two or more consecutive oxyethylene groups in one molecule, wherein the number of oxyethylene groups per polyoxyethylene group is 2 to 60.

7. The fiber sizing composition according to claim 1, wherein The epoxy group concentration in the non-volatile component contained in the fiber sizing composition is 1.5 meq / g or more.

8. A fiber bundle obtained by treating at least one fiber selected from the group consisting of carbon fiber, glass fiber, aramid fiber, ceramic fiber, metal fiber, mineral fiber and slag fiber with the fiber sizing composition according to any one of claims 1 to 7.

9. A fiber product comprising the fiber bundle according to claim 8.

10. A composite material comprising the fiber bundle according to claim 8 and a matrix resin.

11. A composite material comprising the fiber product according to claim 9 and a matrix resin.

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