Fiber sizing agents and fibers

Abstract

To provide a fiber sizing agent which can suppress crystallization when in an aqueous solution state and has excellent sizing properties. [Solution] A fiber sizing agent containing a vinyl ester resin (A) represented by chemical formula (1) and a nonionic surfactant (B), characterized in that the fiber sizing agent contains, in chemical formula (1), a vinyl ester resin (A1) in which n is 1, a vinyl ester resin (A2) in which n is 2, a vinyl ester resin (A3) in which n is 3, and a vinyl ester resin (A4) in which n is 4. TIFF0007676055000012.tif22144R 1 Each independently represents an alkylene group having 1 to 3 carbon atoms, R 2 ,R 3 : each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, n: an integer of 0 to 20

Description

[Technical field]

[0001] The present invention relates to a fiber sizing agent and a fiber. [Background technology]

[0002] A sizing agent is an agent that is applied to fibrous materials such as carbon fibers, and is used for purposes such as reducing damage to the fibrous materials and increasing the bundling ability of the fibrous materials.

[0003] Patent Document 1 describes a fiber sizing agent composition containing a vinyl ester resin (A) represented by the following chemical formula (4) and a nonionic surfactant (B): The vinyl ester resin (A) comprises at least a vinyl ester resin (A1) in which n in the following chemical formula (4) is 0 or 1, and a vinyl ester resin (A2) in which n in the following chemical formula (4) is 2 or more, and n in the following chemical formula (4) per molecule of the vinyl ester resin (A) is 20 or less, The document describes a fiber sizing agent composition in which the ratio (W1 / W2) of the total weight W1 of vinyl ester resins (A1) in which n is 0 or 1 in the following chemical formula (4) to the total weight W2 of vinyl ester resins (A2) in which n is 2 or more in the following chemical formula (4) is 15 / 85 to 90 / 10. [ka]

[0004] In the formula, R 1 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms; R 2 are each independently a structural portion represented by either a methylene group or an isopropylidene group, and R 3 each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n is an integer of 0 or greater.

[0005] The sizing agent described in Patent Document 1 has excellent sizing properties and excellent adhesion between the fibers and the matrix resin. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 7248851 Summary of the Invention [Problem to be solved by the invention]

[0007] The sizing agent described in Patent Document 1 may undergo crystallization of some of its components when in an aqueous solution. If such crystallization occurs during storage of the sizing agent, it may become difficult to use the sizing agent.

[0008] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a fiber sizing agent which is capable of suppressing crystallization when in an aqueous solution state and has excellent sizing properties. [Means for solving the problem]

[0009] The fiber sizing agent according to the present invention for achieving the above object is a fiber sizing agent containing a vinyl ester resin (A) represented by the following chemical formula (1) and a nonionic surfactant (B), and the following chemical formula (1) includes vinyl ester resin (A0) in which n is 0, vinyl ester resin (A1) in which n is 1, vinyl ester resin (A2) in which n is 2, vinyl ester resin (A3) in which n is 3, vinyl ester resin (A4) in which n is 4, and vinyl ester resin (A5) in which n is 5. More than 10 or moreand the content of the vinyl ester resin (A0) in the non-volatile matter is 5% by mass or more and 40% by mass or less, the content of the vinyl ester resin (A1) is 2% by mass or more and 23% by mass or less, the content of the vinyl ester resin (A2) is 2% by mass or more and 26% by mass or less, the content of the vinyl ester resin (A3) is 1% by mass or more and 20% by mass or less, the content of the vinyl ester resin (A4) is 1% by mass or more and 10% by mass or less, and the content of the vinyl ester resin (A5) is 1% by mass or more and 8% by mass or less.

[0010] [ka]

[0011] R 1 Each independently is an alkylene group having 1 to 3 carbon atoms. R 2 ,R 3 Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. n: An integer between 0 and 20

[0012] According to this configuration, n is 0, 1, 2, 3, 4, and 5 to 10, respectively. By containing all of the vinyl ester resins (A0) to (A5) listed above, the generation of crystals when the sizing agent is made into an aqueous liquid can be effectively suppressed, and a high level of sizing ability of the fiber material can be achieved.

[0013] A further characteristic feature of the fiber sizing agent according to the present invention is that, when the total mass of the vinyl ester resin (A1) and the vinyl ester resin (A3) is W1 and the total mass of the vinyl ester resin (A2) and the vinyl ester resin (A4) is W2, the value of W1 / W2 is 0.15 or more and 5 or less.

[0014] According to this configuration, the generation of crystals when the sizing agent is made into an aqueous liquid can be further suppressed.

[0015] A further characteristic feature of the fiber sizing agent according to the present invention is that the value of W1 / W2 is 0.3 or more and less than 2.

[0016] According to this configuration, the generation of crystals when the sizing agent is made into an aqueous liquid can be further suppressed.

[0017] A further characteristic feature of the fiber sizing agent according to the present invention is that, when the total content of the vinyl ester resin (A) and the nonionic surfactant (B) is taken as 100 mass%, the fiber sizing agent contains the vinyl ester resin (A) in an amount of 10 to 90 mass%, and the nonionic surfactant (B) in an amount of 10 to 90 mass%.

[0018] According to this configuration, it is possible to effectively suppress the generation of crystals when the sizing agent is made into an aqueous liquid, and it is possible to specify the content ratio of the vinyl ester resin (A) and the nonionic surfactant (B) that can realize a high level of sizing ability of the fiber material.

[0019] A further characteristic feature of the fiber sizing agent according to the present invention is that it further contains at least one resin (C) selected from vinyl ester resins other than the vinyl ester resin (A), epoxy resins, polyester resins, and urethane resins.

[0020] According to this configuration, by containing any one of the above resins (C), it becomes easier to impart bundling properties to the fiber material.

[0021] A further characteristic feature of the fiber sizing agent according to the present invention is that, when the total content of the vinyl ester resin (A), the nonionic surfactant (B), and the resin (C) is taken as 100% by mass, the fiber sizing agent contains the vinyl ester resin (A) in an amount of 10 to 90% by mass, the nonionic surfactant (B) in an amount of 5 to 85% by mass, and the resin (C) in an amount of 5 to 85% by mass.

[0022] According to this configuration, it is possible to effectively suppress the generation of crystals when the sizing agent is made into an aqueous liquid, and it is possible to specify the content ratios of the epoxy resin (A), the nonionic surfactant (B), and the resin (C) that can achieve a higher level of sizing of the fiber material.

[0023] The characteristic feature of the fiber sizing agent according to the present invention is that the fiber sizing agent is attached to the fiber sizing agent according to any one of the above-mentioned aspects.

[0024] According to this configuration, the present invention can be easily applied to reinforce composite materials whose base material is resin, ceramic, metal, or the like.

[0025] A further characteristic feature of the fiber according to the present invention is that it is a reinforcing fiber.

[0026] According to this configuration, the present invention can be more easily applied to the reinforcement of composite materials whose base material is resin, ceramic, metal, or the like.

[0027] A further characteristic feature of the fiber sizing agent according to the present invention is that the fiber sizing agent is attached to carbon fibers or glass fibers.

[0028] According to this configuration, the present invention is particularly applicable to the reinforcement of composite materials whose base material is resin, ceramic, metal, or the like. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, an embodiment of the present invention will be described. The fiber sizing agent of the present invention (hereinafter simply referred to as "sizing agent") is a fiber sizing agent containing a vinyl ester resin (A) represented by the following chemical formula (1) and a nonionic surfactant (B), and is characterized in that, in the following chemical formula (1), it contains a vinyl ester resin (A1) in which n is 1, a vinyl ester resin (A2) in which n is 2, a vinyl ester resin (A3) in which n is 3, and a vinyl ester resin (A4) in which n is 4. [ka]

[0030] R 1 Each independently is an alkylene group having 1 to 3 carbon atoms. R 2 ,R 3 Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. n: An integer between 0 and 20

[0031] In the present invention, the sizing agent contains a vinyl ester resin (A) in which n is any integer from 1 to 4. That is, the sizing agent of the present invention contains all of the vinyl ester resin (A1) in which n is 1, the vinyl ester resin (A2) in which n is 2, the vinyl ester resin (A3) in which n is 3, and the vinyl ester resin (A4) in which n is 4. As long as this requirement is satisfied, the sizing agent of the present invention may contain a vinyl ester resin (A) with another n, particularly with n=0.

[0032] R 1 is a C1 to C3 alkylene group, and can be, for example, a methylene group or an isopropylidene group.

[0033] R 2 ,R 3 The C1 to C4 alkyl group in the formula (I) can be, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, or a tert-butyl group.

[0034] The vinyl ester resin (A) represented by the above chemical formula (1) can be a reaction product of an epoxy resin and methacrylic acid or acrylic acid. The ratio of the amounts of the reaction substrates when producing the reaction product may be such that the epoxy value of the epoxy resin and the acid value of the methacrylic acid are equal, or one of them is larger.

[0035] The epoxy resin can be separated and purified, for example, as follows, but is not limited to this.

[0036] That is, for example, a mixture of epoxy resins with different molecular weights is dissolved in a solvent (tetrahydrofuran) as a raw material, and the epoxy resins are separated by molecular weight using a GPC separation device. The separated liquid is charged into a reaction vessel (a four-neck glass flask reaction vessel) equipped with a heating / cooling device and a stirring device, and the solvent (tetrahydrofuran) is removed by gradually reducing the pressure to 20 mmHg at 80 to 100°C, for example, to separate and purify the epoxy resins.

[0037] The mixture of epoxy resins may be, for example, jER (registered trademark) series (jER (registered trademark) 828, jER (registered trademark) 834, jER (registered trademark) 1001, jER (registered trademark) 1002, jER (registered trademark) 1004, etc.) manufactured by Mitsubishi Chemical Corporation, NPES series (NPES301, NPES302, etc.) manufactured by Nanya Plastic Corporation, and Sumiepoxy (registered trademark) series (Sumiepoxy (registered trademark) ELM-434, Sumiepoxy (registered trademark) ELM-100, etc.) manufactured by Sumitomo Chemical Co., Ltd., but is not limited thereto.

[0038] The vinyl ester resin (A) can be produced as follows using the above-mentioned separated and purified epoxy resin and methacrylic acid (or acrylic acid).

[0039] That is, epoxy resin and methacrylic acid (or acrylic acid) are added to a container such as a flask and heated to, for example, 60°C, and then hydroquinone and triethylamine are added, after which the temperature is increased to 100°C and the mixture is allowed to react until the acid value becomes 1 or less, thereby obtaining a vinyl ester resin.

[0040] The nonionic surfactant (B) may be any nonionic surfactant commonly used in the art. The nonionic surfactant (B) may be a single compound or a mixture of multiple compounds.

[0041] The nonionic surfactant (B) may be, for example, an alkylene oxide adduct of a compound having a hydroxyl group. Examples of the compound having a hydroxyl group include aromatic alcohols such as tristyrenated phenol, distyrenated phenol, and bisphenol A, and aliphatic alcohols such as dodecyl alcohol, isododecyl alcohol, tetradecyl alcohol, tridecyl alcohol, secondary dodecyl alcohol, secondary tridecyl alcohol, 2-ethylhexyl alcohol, oleyl alcohol, and isononyl alcohol, and aromatic alcohols are preferred. Examples of alkylene oxides include, but are not limited to, ethylene oxide and propylene oxide. Therefore, the nonionic surfactant (B) may preferably be an alkylene oxide adduct of an aromatic alcohol.

[0042] In addition, multiple types of alkylene oxides may be used in combination in the nonionic surfactant (B). The number of alkylene oxides added may be, but is not limited to, 6 moles or more and 40 moles or less per mole of the nonionic surfactant (B).

[0043] The nonionic surfactant (B) may be one type of compound or a mixture of multiple types of compounds.

[0044] It is believed that the sizing agent crystallizes due to the precipitation of the vinyl ester resin (A0). By including all of the vinyl ester resins (A1) to (A4) as in the sizing agent of the present invention, the molecular weight distribution becomes continuous (gentle), and it is believed that the vinyl ester resin (A0) is less likely to precipitate. Therefore, by including all of the vinyl ester resins (A1) to (A4) in which n is 1 to 4 as in this configuration, it is possible to effectively suppress the generation of crystals when the sizing agent is made into an aqueous liquid, and to achieve a high level of sizing ability for fiber materials.

[0045] In the sizing agent of the present invention, when the total mass of the vinyl ester resin (A1) and the vinyl ester resin (A3) is W1 and the total mass of the vinyl ester resin (A2) and the vinyl ester resin (A4) is W2, the value of W1 / W2 is preferably 0.15 or more and 5 or less, and more preferably 0.3 or more and less than 2.

[0046] In this configuration, the mass ratio between the total mass W1 of the vinyl ester resin (A1) and the vinyl ester resin (A3) and the total mass W2 of the vinyl ester resin (A2) and the vinyl ester resin (A4) is specified.

[0047] In this configuration, the generation of crystals when the sizing agent is made into an aqueous liquid can be further suppressed.

[0048] The sizing agent of the present invention preferably contains 10 to 90 mass% of the vinyl ester resin (A) and 10 to 90 mass% of the nonionic surfactant (B), when the total content of the vinyl ester resin (A) and the nonionic surfactant (B) is 100 mass%.

[0049] In this configuration, the generation of crystals when the sizing agent is made into an aqueous liquid can be effectively suppressed, and the content ratio of the vinyl ester resin (A) and the nonionic surfactant (B) can be specified to achieve a high level of sizing ability for fiber materials.

[0050] The sizing agent of the present invention preferably further contains at least one resin (C) selected from vinyl ester resins other than the vinyl ester resin (A), epoxy resins, polyester resins, and urethane resins.

[0051] The vinyl ester resin may be any vinyl ester resin other than the vinyl ester resin (A), and for example, a one-terminated vinyl ester resin may be used.

[0052] The epoxy resin may be any of the epoxy resins exemplified above.

[0053] A polyester resin is a copolymer of a diol monomer and a dicarboxylic acid monomer. Therefore, the polyester resin has, in its molecule, a diol residue, which is a partial structure derived from a diol monomer (a diol compound or a derivative thereof), and a dicarboxylic acid residue, which is a partial structure derived from a dicarboxylic acid monomer (a dicarboxylic acid or a derivative thereof). The composition of a polyester resin is specified by the ratio (molar ratio) of the monomers that make up the molecule.

[0054] The diol monomer constituting the polyester resin may include one or more diol compounds. Examples of the diol compound include, but are not limited to, ethylene glycol, diethylene glycol, bisphenol A, ethylene oxide adduct of bisphenol A (Newpol (registered trademark) BPE series (Newpol (registered trademark) BPE-20, Newpol (registered trademark) BPE-40, Newpol (registered trademark) BPE-100, etc.) manufactured by Sanyo Chemical Industries, Ltd.), and propylene oxide adduct of bisphenol A (Newpol (registered trademark) BP series (Newpol (registered trademark) BP-2P, Newpol (registered trademark) BP-3P, Newpol (registered trademark) BP-5P, etc.) manufactured by Sanyo Chemical Industries, Ltd.).

[0055] The dicarboxylic acid monomer constituting the polyester resin may include one or more dicarboxylic acid compounds, such as, but not limited to, isophthalic acid, terephthalic acid, fumaric acid, maleic acid, and 5-sulfoisophthalic acid alkali metal salts (such as sodium salt, potassium salt, and lithium salt).

[0056] Non-limiting examples of polyester resins include copolymers of diethylene glycol, isophthalic acid, and sodium salt of 5-sulfoisophthalic acid, copolymers of ethylene glycol, diethylene glycol, isophthalic acid, terephthalic acid, and sodium salt of 5-sulfoisophthalic acid, copolymers of an ethylene oxide adduct of bisphenol A and fumaric acid (in other words, copolymers of bisphenol A, ethylene glycol, and fumaric acid), and copolymers of an ethylene oxide adduct of bisphenol A and maleic acid (in other words, copolymers of bisphenol A, ethylene glycol, and maleic acid). The polyester resin may be a single type of compound or a mixture of multiple types of compounds.

[0057] The urethane resin may be, but is not limited to, DISPERCOLL U 54 (manufactured by COVESTRO), Superflex 500M (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Superflex 650 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Superflex 860 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Superflex E-2000 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and the like.

[0058] By containing any one of the above resins (C), it becomes easier to impart bundling properties to the fiber material.

[0059] The sizing agent of the present invention preferably contains 10 to 90 mass% of vinyl ester resin (A), 5 to 85 mass% of nonionic surfactant (B), and 5 to 85 mass% of resin (C), when the total content of vinyl ester resin (A), nonionic surfactant (B), and resin (C) is 100 mass%.

[0060] According to this configuration, it is possible to effectively suppress the generation of crystals when the sizing agent is made into an aqueous liquid, and it is possible to specify the content ratios of the vinyl ester resin (A), the nonionic surfactant (B) and the resin (C) that can achieve a higher level of sizing of the fiber material.

[0061] (Other Ingredients) The sizing agent according to this embodiment may contain components other than the vinyl ester resin (A), the nonionic surfactant (B), and the resin (C). Examples of such other components include, but are not limited to, preservatives, antistatic agents, antioxidants, UV absorbers, antifoaming agents (such as modified silicones), and resins other than the resin (C).

[0062] In addition, a typical embodiment of the sizing agent used in the sizing treatment of a fiber material is a dilution of the non-volatile components such as the vinyl ester resin (A) with a diluent (generally referred to as a sizing liquid). Such a diluent is also an example of the other components. Examples of diluents include water (tap water, industrial water, ion-exchanged water, distilled water, etc.), acetone, methyl ethyl ketone, and N-methyl-2-pyrrolidone, but are not limited thereto. The concentration of the non-volatile components in the sizing agent in an embodiment in which the non-volatile components are diluted with a diluent is not particularly limited, but may be, for example, 10% by mass or more and 60% by mass or less. The non-volatile components of the sizing agent refer to the components that remain after the sizing agent is heated in a hot air dryer at 105°C for 2 hours without volatilization, and the concentration refers to the ratio of the mass of the non-volatile components in the sizing agent to the mass of the sizing agent.

[0063] [Method of producing sizing agent] The sizing agent according to the present embodiment can be obtained by mixing the vinyl ester resin (A), the nonionic surfactant (B), and any other optional components in a known manner, for example by adding water to the vinyl ester resin (A), the nonionic surfactant (B), and any other optional components at a temperature between 20° C. and 90° C. over a period of 5 hours while stirring.

[0064] [How to use the bundling agent] The sizing agent according to the present embodiment is used in the sizing treatment of fiber materials. The sizing treatment is a treatment for attaching a sizing agent to a fiber material, and the method may be any method commonly used in the art for attaching this type of sizing agent to a fiber material. That is, the immersion oiling method, the spray oiling method, the roller oiling method, the guide oiling method, and the like may be adopted. Note that when applying each method, the sizing agent may be appropriately diluted with a diluent such as water.

[0065] The amount of the sizing agent attached to the fiber material is not particularly limited. For example, it is preferable that the amount of the sizing agent attached to the entire fiber material to which the sizing agent is attached is 0.1% by mass to 3% by mass.

[0066] In addition, when the sizing agent according to the present embodiment is applied in the production of reinforced fibers, reinforced fibers having the sizing agent attached to a fiber material are obtained. This reinforced fiber is an example of the fiber according to the present invention. The fiber material is preferably an inorganic fiber, and in this case, the reinforced fiber is an inorganic fiber having a sizing agent attached thereto. In addition, it is more preferable that the inorganic fiber is a carbon fiber or a glass fiber.

[0067] These reinforcing fibers can be used in composite materials whose matrix is ​​resin, ceramic, metal, etc. A composite material characterized by including the above-mentioned reinforcing fibers and a matrix resin that is a thermosetting resin is one embodiment of the present invention.

[0068] Other embodiments The present invention may be a fiber sizing agent containing a vinyl ester resin (A) represented by the following chemical formula (1) and a nonionic surfactant (B), characterized in that the fiber sizing agent contains a vinyl ester resin (A1) in which n is 1, a vinyl ester resin (A2) in which n is 2, a vinyl ester resin (A3) in which n is 3, and a vinyl ester resin (A4) in which n is 4 in the following chemical formula (1). 1 are each independently an alkylene group having 1 to 3 carbon atoms, and R 2 and R 3are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n is an integer of 0 to 20. According to this configuration, by containing all of the vinyl ester resins (A1) to (A4) in which n is 1 to 4, the generation of crystals when the sizing agent is made into an aqueous liquid can be effectively suppressed, and the sizing ability of the fiber material can be achieved at a high level. [ka]

[0069] Regarding other configurations, it should be understood that the embodiments disclosed in this specification are illustrative in all respects and that the scope of the present invention is not limited thereto. A person skilled in the art would easily understand that appropriate modifications are possible without departing from the spirit of the present invention. Therefore, other embodiments modified without departing from the spirit of the present invention are naturally included in the scope of the present invention. EXAMPLES

[0070] Example 1 The vinyl ester resin (A) represented by the above chemical formula (1) was produced by the following method.

[0071] First, the raw epoxy resin was separated and purified. 400 g of jER (registered trademark) 1001 (manufactured by Mitsubishi Chemical Corporation) was dissolved in tetrahydrofuran to a solid content of 2%, and the epoxy resin was separated by molecular weight using a GPC separation apparatus (recycle separation HPLC: LC-9130NEXT (manufactured by Japan Analytical Industry Co., Ltd.)). Then, each separated solution was charged into a reaction vessel (a glass four-neck flask reaction vessel) equipped with a heating / cooling device and a stirring device, and the pressure was gradually reduced to 20 mmHg at 90° C. to remove tetrahydrofuran, and the following compounds (a-0) to (a-5) (epoxy resins) were obtained.

[0072] Bisphenol type epoxy resin (a-0) (molecular weight 340) where p in chemical formula (2) is 0 Bisphenol type epoxy resin (a-1) (molecular weight 624) where p in chemical formula (2) is 1 Bisphenol type epoxy resin (a-2) (molecular weight 908) where p in chemical formula (2) is 2 Bisphenol type epoxy resin (a-3) (molecular weight 1192) where p is 3 in chemical formula (2) Bisphenol type epoxy resin (a-4) where p in chemical formula (2) is 4 (molecular weight 1476) Bisphenol-type epoxy resin (a-5) (Mn 1760 or more) in which p in the chemical formula (2) is 5 or more and 10 or less

[0073] [ka]

[0074] The epoxy resins (a-0) to (a-5) are each represented by R in chemical formula (2). 4 is a compound having an isopropylidene group.

[0075] A vinyl ester resin (A) was produced as follows using any one of the epoxy resins (a-0) to (a-5) produced as above, and methacrylic acid or acrylic acid.

[0076] 344 parts by mass of epoxy resin (a-0) and 172 parts by mass of methacrylic acid were added to a four-necked glass flask and heated to 60°C with stirring, after which 0.5 parts by mass of hydroquinone and 0.5 parts by mass of triethylamine were added and the temperature was raised to 100°C. The mixture was allowed to react until the acid value became 1 or less, producing a vinyl ester resin (A0-1) in which n is 0.

[0077] In addition, 344 parts by mass of epoxy resin (a-0) and 144 parts by mass of acrylic acid were added to a four-necked glass flask and heated to 60°C with stirring, and then 0.5 parts by mass of hydroquinone and 0.5 parts by mass of triethylamine were added, and the temperature was increased to 100°C and reacted until the acid value became 1 or less, producing a vinyl ester resin (A0-2) in which n is 0.

[0078] In addition, 344 parts by mass of epoxy resin (a-0), 86 parts by mass of methacrylic acid, and 72 parts by mass of acrylic acid were added to a four-necked glass flask and heated to 60°C with stirring, and then 0.5 parts by mass of hydroquinone and 0.5 parts by mass of triethylamine were added, and the temperature was raised to 100°C and the mixture was reacted until the acid value became 1 or less, producing a vinyl ester resin (A0-3) in which n is 0.

[0079] In the above-mentioned method, the vinyl ester resin (A1-1) to the vinyl ester resin (A1-3) in which n is 1 is produced by replacing the epoxy resin (a-0) with the epoxy resin (a-1), the vinyl ester resin (A2-1) to the vinyl ester resin (A2-3) in which n is 2 is produced by replacing the epoxy resin (a-0) with the epoxy resin (a-2), the vinyl ester resin (A3-1) to the vinyl ester resin (A3-3) in which n is 3 is produced by replacing the epoxy resin (a-0) with the epoxy resin (a-3), the vinyl ester resin (A4-1) to the vinyl ester resin (A4-3) in which n is 4 is produced by replacing the epoxy resin (a-0) with the epoxy resin (a-4), and the vinyl ester resin (A4-0) to the vinyl ester resin (A4-3) in which n is 5 is produced by replacing the epoxy resin (a-0) with the epoxy resin (a-5). More than 10 or more Vinyl ester resin (A5-1) to vinyl ester resin (A5-3) were produced.

[0080] An overview of the vinyl ester resin (A) produced is shown in Table 1.

[0081] [Table 1]

[0082] In addition, in A0-3, for convenience, in Table 1, [R 2 : Methyl group, R 3 However, A0-3 is a mixture of compounds having the following functional groups. The same is true for A1-3 to A5-3. [R 2 : Methyl group, R 3 : methyl group] [R 2 : Hydrogen atom, R3 :hydrogen atom] [R 2 : Hydrogen atom, R 3 : methyl group]

[0083] Example 2 The sizing agents of the present invention were produced by the above-mentioned sizing agent production method (Invention Examples 1 to 26). That is, the sizing agents were produced by adding water to the vinyl ester resin (A), the nonionic surfactant (B), and any other optional components while stirring at temperatures between 20°C and 90°C over 5 hours.

[0084] In Examples 1 to 6 of the present invention, the vinyl ester resin (A) contains vinyl ester resin (A0-1) to vinyl ester resin (A5-1), the nonionic surfactant (B) contains at least one of the following (B-1) to (B-3), and the resin (C) contains at least one of the following (EP-1), (PE-1), (PE-2), (PU-1), (VE-1), and (VE-2).

[0085] In addition, in Examples 7 to 12 of the present invention, the vinyl ester resin (A) contains vinyl ester resin (A0-2) to vinyl ester resin (A5-2), the nonionic surfactant (B) contains at least one of the following (B-1) to (B-3), and the resin (C) contains at least one of the following (EP-1), (PE-1), (PE-2), (PU-1), (VE-1), and (VE-2).

[0086] In addition, in Examples 13 to 17 of the present invention, the vinyl ester resin (A) contains vinyl ester resin (A0-3) to vinyl ester resin (A5-3), the nonionic surfactant (B) contains at least one of the following (B-1) to (B-3), and the resin (C) contains at least one of the following (EP-1), (PE-1), (PE-2), (PU-1), and (VE-1).

[0087] In addition, in Example 18 of the present invention, the vinyl ester resin (A) contains vinyl ester resins (A0-1), (A2-2), (A1-3), (A3-3), (A4-3), and (A5-3), the nonionic surfactant (B) contains the following (B-1) and (B-3), and the resin (C) contains (VE-1).

[0088] In addition, in Examples 19 to 26 of the present invention, the vinyl ester resin (A) contains vinyl ester resin (A0-1) to vinyl ester resin (A5-1), and the nonionic surfactant (B) contains at least one of the following (B-1) and (B-2).

[0089] The mass percentages (total 100 mass%) of the vinyl ester resin (A), nonionic surfactant (B) and resin (C) in Inventive Examples 1 to 18 are shown in Tables 2-1 and 2-2, and the mass percentages (total 100 mass%) of the vinyl ester resin (A) and nonionic surfactant (B) in Inventive Examples 19 to 26 are shown in Tables 2-2 and 2-3.

[0090] [Table 2-1]

[0091] [Table 2-2]

[0092] [Table 2-3]

[0093] (B-1): A compound in which 30 moles of ethylene oxide and 6 moles of propylene oxide are added to 1 mole of tristyrenated phenol. (B-2): A compound in which 27 moles of ethylene oxide are added to 1 mole of tristyrenated phenol. (B-3): A compound in which 18 moles of ethylene oxide are added to 1 mole of bisphenol A.

[0094] (EP-1): Sumiepoxy (registered trademark) ELM-434 (manufactured by Sumitomo Chemical Co., Ltd.) (epoxy resin) (PE-1): A polyester resin having a molar ratio of 5-sodium sulfoisophthalic acid:isophthalic acid:diethylene glycol of 4:46:50 and a number average molecular weight of 15,000. (PE-2): Fumaric acid and Nupol BPE-20 (manufactured by Sanyo Chemical Industries, Ltd.) in a molar ratio of 3:4 to produce a polyester resin. (PU-1): Urethane resin, which is the non-volatile resin part of DISPERCOLL U 54 (manufactured by COVESTRO) (VE-1): VE-1 (single-terminated vinyl ester epoxy resin) synthesized by the method described below (VE-2): VE-2 (single-terminated vinyl ester epoxy resin) synthesized by the method described below

[0095] VE-1 was produced as follows. 344 parts by mass of epoxy resin (a-0) and 86 parts by mass of methacrylic acid were added to a four-neck glass flask and heated to 60°C while stirring, after which 0.5 parts by mass of hydroquinone and 0.5 parts by mass of triethylamine were added, and the temperature was raised to 100°C and reacted until the acid value was 1 or less to obtain a reaction product. 400 g of this reaction product was dissolved in tetrahydrofuran to a solid content concentration of 2%, and the reaction product was fractionated by molecular weight using the above-mentioned GPC fractionation apparatus. Thereafter, each fraction was charged into the above-mentioned reaction vessel equipped with a heating / cooling device and a stirring device, and the pressure was gradually reduced to 20 mmHg at 90°C to remove tetrahydrofuran, and R in chemical formula (3) was obtained. 5 is an isopropylidene group, q is 0, R 6 Compound VE-1 (molecular weight 430) in which the aryl group is a methyl group was obtained.

[0096] [ka]

[0097] VE-2 was prepared as follows. 624 parts by mass of epoxy resin (a-0) and 86 parts by mass of methacrylic acid were added to a four-neck glass flask and heated to 60°C while stirring, after which 0.8 parts by mass of hydroquinone and 0.8 parts by mass of triethylamine were added, and the temperature was raised to 100°C and reacted until the acid value was 1 or less to obtain a reaction product. 400 g of this reaction product was dissolved in tetrahydrofuran to a solid content concentration of 2%, and the reaction product was separated by molecular weight using the above-mentioned GPC separation device. Thereafter, each separated solution was charged into the above-mentioned reaction vessel equipped with a heating / cooling device and a stirring device, and the pressure was gradually reduced to 20 mmHg at 90°C to remove tetrahydrofuran, and R in chemical formula (3) was obtained. 5 is an isopropylidene group, q is 1, R 6 Compound VE-2 (molecular weight 710) in which the aryl group is a methyl group was obtained.

[0098] Furthermore, when the total mass of the vinyl ester resin (A1-1) and the vinyl ester resin (A3-1) is W1 and the total mass of the vinyl ester resin (A2-1) and the vinyl ester resin (A4-1) is W2, the value of W1 / W2 is shown in Tables 2-1 to 2-3.

[0099] The sizing agent of the comparative examples was produced by the above-mentioned method for producing the sizing agent (Comparative Examples 1 and 2). In Comparative Example 1, the vinyl ester resin (A) contains vinyl ester resins (A0-1), (A2-1) to (A5-1), and the nonionic surfactant (B) contains (B-1). In Comparative Example 2, the vinyl ester resin (A) contains vinyl ester resins (A0-1) to (A2-1), and the nonionic surfactant (B) contains (B-1). The mass percentages of the vinyl ester resin (A) and the nonionic surfactant (B) in Comparative Examples 1 and 2 are shown in Table 2-3 (total 100 mass%).

[0100] <Evaluation method> For the above-mentioned invention examples 1 to 26 and comparative examples 1 and 2, the crystallization suppression ability and sizing ability of the sizing agent were evaluated.

[0101] The crystallization inhibition ability was evaluated by preparing 100 mL of a 30% by mass aqueous solution of the bundling agent in each of the invention examples and comparative examples, sealing it in a 140 mL transparent glass bottle, and leaving it at 0°C for 10 days. The crystalline deposit that had accumulated at the bottom was then evaluated according to the following criteria.

[0102] S: No crystalline deposits were observed and crystallization inhibition was very good. A: Crystalline deposits were deposited on the bottom of the glass bottle, but they were small, covering less than 10% of the bottom area, and the crystallization inhibition was good. B: Crystalline deposits were deposited on the bottom of the glass bottle, but they accounted for 10% to less than 20% of the bottom area, and crystallization inhibition was at an acceptable level. C: A large amount of crystalline deposits were deposited on the bottom of the glass bottle, occupying more than 20% of the bottom area, and the crystallization inhibition was poor.

[0103] The bundling ability was evaluated by filling a sizing bath with a sizing solution (non-volatile content 4%) containing the sizing agent in each of the present invention examples and each of the comparative examples, and passing a fiber material (carbon fiber or glass fiber) through the sizing bath to apply the sizing agent. The roll of fiber material to which the sizing agent had been applied was set on a creel and unwound at a speed of 5 m per minute, and the state of the fiber material passing through the roller immediately after unwinding was observed. Depending on the observation results, the bundling ability of the fiber material provided by the sizing agent in each of the present invention examples and each of the comparative examples was evaluated on the following three-point scale.

[0104] A: Almost no fiber material was found to be wound around the roller, and the passed fiber material was well-cohered. B: A small amount of fibrous material was found to be wound around the roller, but the fibrous material that had passed through was well held together. C: A large amount of fibrous material was wrapped around the roller, and the fibrous material that passed through was seen to break apart.

[0105] <Evaluation Results> The results of evaluation of the crystallization suppression and focusing properties of each of the invention examples and comparative examples are shown in Tables 2-1 to 2-3.

[0106] In terms of crystallization suppression, Examples 1 to 21 of the present invention were rated S (very good), Examples 22 to 24 of the present invention were rated A (good), and Examples 25 and 26 of the present invention were rated B (acceptable level). That is, Examples 1 to 26 of the present invention were found to be able to effectively suppress crystallization.

[0107] At this time, the value of W1 / W2 was 0.333 to 1.875 in Inventive Examples 1 to 21 (S rating), 0.208 to 4.667 in Inventive Examples 22 to 24 (A rating), and 0.111 to 5.429 in Inventive Examples 25 and 26 (B rating).

[0108] On the other hand, Comparative Examples 1 and 2 were each rated C (poor).

[0109] The sizing agent of the present invention (Invention Examples 1 to 26) contains all of the vinyl ester resins (A1-1) to (A4-1). In contrast, Comparative Example 1 does not contain the vinyl ester resin (A1-1), and Comparative Example 2 does not contain the vinyl ester resins (A3-1) and (A4-1). It is believed that the sizing agent crystallizes due to the precipitation of the vinyl ester resin (A0-1). From the above results, it is believed that by containing all of the vinyl ester resins (A1-1) to (A4-1) like the sizing agent of the present invention, the molecular weight distribution becomes more continuous (gentler) than in each of the comparative examples, and the vinyl ester resin (A0-1) is less likely to precipitate.

[0110] The values ​​of W1 / W2 were 0.125 and 2.000 in Comparative Examples 1 and 2, respectively.

[0111] From the above, it was recognized that the lower limit of W1 / W2 should be greater than 0.125, for example 0.15, and preferably 0.3, and the upper limit of W1 / W2 should be 5.429 or less, for example 5,000 or less, and preferably less than 2,000.

[0112] In other words, it was found that a value of W1 / W2 of 0.15 or more and 5 or less can further suppress the occurrence of crystallization, which is preferable, and that a value of W1 / W2 of 0.3 or more and less than 2 can further suppress the occurrence of crystallization, which is even more preferable.

[0113] In terms of focusing ability, Examples 1 to 18 of the present invention were rated A (almost no winding was observed), and Examples 19 to 26 of the present invention were rated B (slight winding was observed). In other words, Examples 1 to 26 of the present invention were at or above the permissible level.

[0114] In this case, Inventive Examples 1 to 18 contain a vinyl ester resin (A), a nonionic surfactant (B) and a resin (C), and Inventive Examples 19 to 26 contain an epoxy resin (A) and a nonionic surfactant (B).

[0115] In other words, it was found that by containing any of the above-mentioned resins (C), as in Examples 1 to 18 of the present invention (Rating A), it is easier to impart bundling properties to the fiber material than when the resin (C) is not contained (Examples 19 to 26 of the present invention).

[0116] In Inventive Examples 19 to 26, the total content of the vinyl ester resin (A) and the nonionic surfactant (B) was 100 mass%. That is, in Inventive Examples 19 to 26, the content of the vinyl ester resin (A) was 67 to 76 mass%, and the content of the nonionic surfactant (B) was 24 to 33 mass%.

[0117] It was found that when the ratio of each component satisfies the above requirements, the generation of crystals when the sizing agent is made into an aqueous liquid can be effectively suppressed, and a high level of sizing ability of fiber materials can be achieved.

[0118] When the total content of the vinyl ester resin (A) and the nonionic surfactant (B) is taken as 100 mass% (Invention Examples 19 to 26), it is believed that the same effects as those described above can be obtained by including 10 to 90 mass% of the vinyl ester resin (A) and 10 to 90 mass% of the nonionic surfactant (B).

[0119] In Inventive Examples 1 to 18, the total content of the vinyl ester resin (A), nonionic surfactant (B) and resin (C) was 100 mass%. That is, in Inventive Examples 1 to 18, the content of the vinyl ester resin (A) was 18 to 58 mass%, the content of the nonionic surfactant (B) was 15 to 30 mass%, and the content of the resin (C) was 20 to 52 mass%.

[0120] It was found that when the ratio of each component satisfies the above requirements, the generation of crystals when the sizing agent is made into an aqueous liquid can be effectively suppressed, and a higher level of sizing ability of fiber materials can be achieved.

[0121] When the total content of the epoxy resin (A), the nonionic surfactant (B), and the resin (C) is 100 mass%, it is believed that the same effects as those described above can be obtained by containing the epoxy resin (A) in an amount of 10 to 90 mass%, the nonionic surfactant (B) in an amount of 5 to 85 mass%, and the resin (C) in an amount of 5 to 85 mass%. [Industrial Applicability]

[0122] The present invention can be used, for example, in the sizing process of textile materials.

Claims

1. A fiber sizing agent comprising a vinyl ester resin (A) represented by the following chemical formula (1) and a nonionic surfactant (B), In the following chemical formula (1), the vinyl ester resin includes a vinyl ester resin (A0) in which n is 0, a vinyl ester resin (A1) in which n is 1, a vinyl ester resin (A2) in which n is 2, a vinyl ester resin (A3) in which n is 3, a vinyl ester resin (A4) in which n is 4, and a vinyl ester resin (A5) in which n is 5 or more and 10 or less, Of the non-volatile content, The content of the vinyl ester resin (A0) is 5% by mass or more and 40% by mass or less, The content of the vinyl ester resin (A1) is 2% by mass or more and 23% by mass or less, The content of the vinyl ester resin (A2) is 2% by mass or more and 26% by mass or less, The content of the vinyl ester resin (A3) is 1% by mass or more and 20% by mass or less, The content of the vinyl ester resin (A4) is 1% by mass or more and 10% by mass or less, and The content of the vinyl ester resin (A5) is 1% by mass or more and 8% by mass or less. A fiber sizing agent characterized by: 【Chemistry 1】 R １ each independently represents an alkylene group having 1 to 3 carbon atoms R ２ , R ３ Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. n: an integer between 0 and 20

2. 2. The fiber sizing agent according to claim 1, wherein a value of W1 / W2 is 0.15 or more and 5 or less, where W1 is a total mass of the vinyl ester resin (A1) and the vinyl ester resin (A3) and W2 is a total mass of the vinyl ester resin (A2) and the vinyl ester resin (A4).

3. The fiber sizing agent according to claim 2, wherein the value of W1 / W2 is 0.3 or more and less than 2.

4. 2. The fiber sizing agent according to claim 1, wherein the vinyl ester resin (A) is contained in an amount of 10 to 90 mass%, and the nonionic surfactant (B) is contained in an amount of 10 to 90 mass%, when the total content of the vinyl ester resin (A) and the nonionic surfactant (B) is taken as 100 mass%.

5. 2. The fiber sizing agent according to claim 1, further comprising at least one resin (C) selected from a vinyl ester resin other than the vinyl ester resin (A), an epoxy resin, a polyester resin, and a urethane resin.

6. 6. The fiber sizing agent according to claim 5, wherein the vinyl ester resin (A) is contained in an amount of 10 to 90 mass%, the nonionic surfactant (B) is contained in an amount of 5 to 85 mass%, and the resin (C) is contained in an amount of 5 to 85 mass%, when the total content of the vinyl ester resin (A), the nonionic surfactant (B), and the resin (C) is taken as 100 mass%.

7. A fiber having the fiber sizing agent according to any one of claims 1 to 6 attached thereto.

8. The fiber of claim 7 which is a reinforcing fiber.

9. The fiber according to claim 7 , wherein the fiber sizing agent is attached to carbon fiber or glass fiber.

Images