TW201920388A - Sizing agent for reinforced fiber and use thereof - Google Patents

Abstract

The present invention provides a sizing agent for reinforced fiber which enables excellent physical properties of molded products, and a carbon fiber strand having the sizing agent adhered thereto. The sizing agent for reinforced fiber of the present invention comprises: a component (A) which is an acrylic resin, a rubber component (B), and a component (C) which is a liquid rosin ester resin. The weight ratio of the component (C) to the non-volatile content of the sizing agent is preferably 20 to 80 mass %. It is preferable that the non-volatile content of the fiber sizing agent is solid at 20 DEG C. The viscosity of the component (C) at 50 DEG C, 1 atm is preferably 500,000 mPa.s or less.

Description

Bundle for reinforcing fibers and use thereof

The present invention relates to a sizing agent for reinforcing fibers (also referred to as a sizing agent in this case) and use thereof.

In a carbon fiber bundle using polyolefin as a matrix resin, it is common to use an acid-modified polyolefin resin as a bundling agent (Patent Document 1).

However, the film of polyolefin modified by acid is extremely hard and brittle, and the fiber protection is poor. In addition, since the sizing agent layer is damaged due to poor flexibility due to deformation, etc., there is a problem that the physical properties of the molded article become poor.

[Prior technical literature] [Patent Literature]

Patent Document 1: Japanese Patent Application Laid-Open No. 2015-131889

In view of this prior art, it is an object of the present invention to provide a sizing agent for reinforcing fibers which is excellent in the physical properties of a molded article, and to make the sizing agent Carbon fiber bundles made from binding agents.

The present inventors conducted intensive investigations, and as a result, found that the above-mentioned problem can be solved by a bundling agent for reinforcing fibers containing a specific component.

That is, the sizing agent for reinforcing fibers of the present invention contains the component (A) of the acrylic resin, the rubber component (B), and the component (C) of the liquid rosin ester resin.

The weight ratio of the component (C) to the non-volatile content of the reinforcing fiber sizing agent is preferably 20 to 80% by weight.

The non-volatile content of the aforementioned reinforcing agent for reinforcing fibers is preferably solid at 20 ° C.

The viscosity of the aforementioned component (C) at 50 ° C and 1 atm is preferably 500,000 mPa · s or less.

The reinforcing fiber bundle of the present invention is a product obtained by attaching the aforementioned reinforcing agent for reinforcing fibers to a raw synthetic fiber bundle.

The fiber-reinforced composite material of the present invention contains a polyolefin resin and the aforementioned reinforcing fiber bundles.

The carbon fiber bundle obtained by adhering the reinforcing fiber sizing agent of the present invention has excellent physical properties of a molded product. The fiber-reinforced composite material of the present invention has excellent physical properties of a molded product.

The bundling agent for reinforcing fibers of the present invention will be described in detail below.

[Ingredient (A)]

The component (A) is an acrylic resin. The component (A) in the reinforcing fiber sizing agent of the present invention exerts a function of exhibiting tack. The reason why the component (A) exhibits the effect of exhibiting viscosity is unknown, but it is presumed to be caused by viscoelastic behavior.

As the raw material of the acrylic resin, in addition to the acrylic monomer, other monomers having a polymerizable unsaturated group may be used as necessary.

The description of "(meth) acrylic acid" in the present invention means either or both of "acrylic acid" and "methacrylic acid".

Examples of the acrylic monomer include (meth) acrylic compounds.

Examples of the (meth) acrylic compound include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and n-butyl (meth) acrylate. , Cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, tetrahydrofuran (meth) acrylate, ( Isoamyl (meth) acrylate, benzyl (meth) acrylate, epoxypropyl (meth) acrylate, diethylene glycol di (meth) acrylate, 1,4-di (meth) acrylate Butanediol ester, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, glyceryl di (meth) acrylate, and the like.

Moreover, the said monomer which has a polymerizable unsaturated group can be used in the range which does not influence performance. Examples include styrene, α-methylstyrene, p-methylstyrene, chloromethylstyrene, vinyl acetate, and bar Bean acid, 3-butenoic acid, 4-pentenoic acid, 2-hexenoic acid, 3-hexenoic acid, 5-hexenoic acid, 2-heptenoic acid, 3-heptenoic acid, 6-heptenoic acid , 3-octenenoic acid, 7-octenenoic acid, 2-nonenoic acid, 3-nonenoic acid, 8-nonenoic acid, 9-decenoic acid, 1-undecenoic acid, 3-allyloxy Monomers of propionic acid, allyloxyvaleric acid, ω-carbonyl-polycaprolactone monoacrylate, itaconic acid (anhydride), maleic acid (anhydride), and fumaric acid.

The acrylic resin (A) can be heated, for example, in an organic solvent and / or water in the presence of a polymerization initiator at a temperature of 60 to 140 ° C. to perform the heating Produced by free radical polymerization. Examples of the organic solvent include aromatic solvents such as toluene and xylene; cycloaliphatic solvents such as cyclohexanone; ester solvents such as butyl acetate and ethyl acetate; isobutanol, n-butanol, and isopropanol , Sorbitol, propylene glycol monomethyl ether acetate, and the like (Cellosolve); methyl ethyl ketone, methyl isobutyl ketone and other ketones. These solvents can be used alone or in combination of two or more.

Examples of the polymerization initiator include couples such as 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2-methylbutyronitrile), and azobiscyanovaleric acid. Nitrogen compounds; tertiary butyl peroxy trimethyl acetate, tertiary butyl peroxy benzate, tertiary butyl peroxy-2-ethylhexanoate, diperoxide (tertiary Butyl), organic peroxides such as cumene hydrogen peroxide, benzoyl peroxide, tertiary butyl hydrogen peroxide, etc .; inorganic peroxides such as hydrogen peroxide, ammonium persulfate, potassium persulfate, sodium persulfate, etc. Oxides, etc. These polymerization initiators may be used alone or in combination of two or more. The polymerization initiator is preferably used in a range of 0.1 to 10% by mass based on the total of the monomers serving as a raw material of the acrylic resin (A). The acrylic resin (A) is dissolved or dispersed in The method of the aqueous medium includes a method of polymerizing the acrylic resin (A) in the aqueous medium, a method of mixing the acrylic resin (A) and the aqueous medium, and mixing and neutralizing the acrylic resin (A) with the latter and Method of the aforementioned aqueous medium and the like.

When the acrylic resin (A) is neutralized, a basic compound may be used. Examples of such basic compounds include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, and 2-amine. Organic amines such as ethyl alcohol, 2-dimethylaminoethanol; inorganic basic compounds such as ammonia, sodium hydroxide, potassium hydroxide; tetramethylammonium hydroxide, tetra-n-butylammonium hydroxide, Methyl benzyl ammonium quaternary ammonium hydroxide and the like. Among these, organic amines and ammonia (which may be ammonia water) are preferably used. These basic compounds can be used alone or in combination of two or more.

[Ingredient (B)]

The component (B) is rubber. The component (B) in the bunching agent for reinforcing fibers of the invention of the present application has a function of improving adhesion to a matrix. Although the reason why the component (B) exhibits the effect of improving the adhesion to the substrate is unknown, it is presumed that the affinity with the substrate is high.

The component (B) includes, for example, a vinylpyridine-styrene-butadiene-based copolymer, a modified product of a vinylpyridine-styrene-butadiene-based copolymer modified with a carboxyl group, and the like, Styrene-butadiene-based copolymers and their modified products, acrylonitrile-butadiene-based copolymers and their modified products, natural rubber, chloroprene rubber, butyl rubber, acrylate copolymer latex, etc., 2 types can be used the above. Among them, styrene butadiene rubber and natural rubber are preferred.

[Ingredient (C)]

The component (C) is a liquid rosin ester resin, and the component (C) in the sizing agent for reinforcing fibers of the present invention has a function of improving the affinity with the matrix resin. Although the reason why the component (C) exerts an effect of improving the affinity with the matrix resin is unknown, it is presumed that the reason is the molecular structure and mobility. The so-called "liquid" of the liquid rosin ester resin means that it has fluidity at normal temperature and pressure (1 atm, 30 ° C). More specifically, it means that when the composition is tilted at 45 °, the shape cannot be maintained for more than 10 minutes and a change in shape occurs.

More specifically, the viscosity at 50 ° C and 1 atm is usually 1,000,000 mPa · s or less, preferably 500,000 mPa · s or less, particularly preferably 400,000 mPa · s or less, and more preferably 300,000 mPa · s or less. A preferred lower limit is 300,000 mPa‧s. By satisfying the physical properties within this range, the affinity with the matrix resin can be improved, and bonding can be easily performed.

In addition, the rosin ester means an ester compound derived from rosin, and examples thereof include compounds obtained by esterifying rosin with a hydroxyl-containing compound.

Rosin is a natural resin obtained from pine wood, and it is a mixture containing Abietic Acid and its isomers in various ratios. Examples of the content other than rosin acid include dehydro sorbic acid, dihydro sorbic acid, neosorbic acid, pimaric acid, isopimaric acid, l-spirosaric acid, and pelicric acid. )Wait.

The above-mentioned hydroxyl-containing compound is not particularly limited, and examples thereof include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, and 1,3-butanedidiol. Alcohol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, octanediol, dioxane Compounds with two hydroxyl groups, such as propylene glycol and bisphenol A; glycerol, tris Compounds having 3 hydroxyl groups such as methylolethane and trimethylolpropane; compounds having 4 hydroxyl groups such as neopentyl alcohol, sorbose, and diglycerol; compounds having 4 hydroxyl groups such as sorbitol and dipentaerythritol 6 hydroxy compounds.

As the rosin ester (C), a compound obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide to the above-mentioned esterified product can also be used. The addition of these alkylene oxides can be performed according to a usual method.

[Bundling agent for reinforcing fibers]

The weight ratio of the aforementioned component (A) in the non-volatile content of the sizing agent is preferably 20 to 60% by weight, particularly preferably 20 to 50% by weight, more preferably 20 to 40% by weight, and particularly preferably 20 to 30% by weight. When it is less than 20% by weight, the viscosity may be insufficient, and when it exceeds 80% by weight, the viscosity may be too strong and hair balls may be generated in the process.

The weight ratio of the aforementioned component (B) in the non-volatile content of the sizing agent is preferably 20 to 80% by weight, particularly preferably 20 to 70% by weight, more preferably 20 to 60% by weight, and particularly preferably 20 to 50% by weight. When it is less than 20% by weight, the adhesive force may be insufficient, and when it exceeds 80% by weight, the texture may become too hard.

The weight ratio of the aforementioned component (C) in the non-volatile content of the sizing agent is preferably 20 to 80% by weight, particularly preferably 30 to 80% by weight, more preferably 30 to 70% by weight, and particularly preferably 40 to 60% by weight. When it is less than 20% by weight, the affinity with the matrix resin may be reduced. When it exceeds 80% by weight, the sizing agent may become liquid, and the adhesion may be insufficient.

The sizing agent for reinforcing fibers of the present invention is preferably one in which the non-volatile content of the sizing agent is solid at 20 ° C, from the viewpoint of improving the adhesion. The so-called solid means that it does not exist at normal temperature and pressure (1atm, 20 ℃). People with liquidity. More specifically, it means that when the composition is inclined at 45 °, the shape can be maintained for more than 10 minutes without any change in shape. When the non-volatile content of the sizing agent is liquid at 20 ° C, it is in the state of having a liquid sizing agent in solid carbon fibers. The sizing agent functions as a lubricant and causes the matrix / carbon fiber to slide. Will decrease. The term "non-volatile matter" as used in this specification refers to a completely dry component when a heat treatment is performed at 105 ° C to remove solvents and the like, and to reach a constant amount.

[Reinforced fiber bundle]

The reinforcing fiber bundle of the present invention is a reinforcing fiber for reinforcing the thermosetting resin or the thermoplastic matrix resin by attaching the aforementioned reinforcing agent for reinforcing fibers to the raw synthetic fiber bundle.

The manufacturing method of the reinforced fiber bundle of this invention is a manufacturing method including the process of attaching the said binding agent for reinforcing fibers to a raw material synthetic fiber bundle, and drying the obtained deposit to a sizing process.

The method for attaching the reinforcing fiber bundling agent to the raw synthetic fiber bundle to obtain an attachment is not particularly limited, and the reinforcing fiber bundling can be performed by a contact roll method, a roll dipping method, a spray method, or other generally known methods. A method for attaching an agent to a raw synthetic fiber bundle. Among these methods, the roll dipping method is preferable because the bundling agent for reinforcing fibers can uniformly adhere to the raw synthetic fiber bundle.

The drying method of the obtained adherend is not specifically limited, For example, it can heat-dry by a heating roll, a hot air, a hot plate, etc.

When the reinforcing fiber sizing agent of the present invention is attached to the raw synthetic fiber bundle, it may be adhered after mixing all the constituent components of the reinforcing fiber sizing agent, or the constituent components may be adhered in two or more stages. this In addition, as long as the effects of the present invention are not hindered, thermosetting resins such as epoxy resins, vinyl ester resins, phenol resins, and / or polyolefin resins, nylon resins other than the polymer component of the present invention, Thermoplastic resins such as polycarbonate resin, polyester resin, polyacetal resin, ABS resin, phenoxy resin, polymethyl methacrylate resin, polyphenylene sulfide resin, polyetherimine resin, polyetherketone resin, etc. Synthetic fiber bundles in raw materials.

The reinforcing fiber bundle of the present invention uses reinforcing fibers that are composite materials using various thermosetting resins or thermoplastic resins as matrix resins, and the use form may be a state of continuous fibers or a state of being cut to a predetermined length.

The adhesion amount of the non-volatile content of the reinforcing fiber bundling agent to the raw material synthetic fiber bundle can be appropriately selected, and can be set to a necessary amount for the synthetic fiber bundle to have a desired function. It is preferably 0.1 to 20% by weight. In the synthetic fiber bundle in the state of continuous fibers, the adhesion amount is particularly preferably 0.1 to 10% by weight, and more preferably 0.5 to 5% by weight, relative to the raw synthetic fiber bundle. The fiber bundle cut into a predetermined length is particularly preferably 0.5 to 20% by weight, and more preferably 1 to 10% by weight.

When the adhesion amount of the reinforcing fiber bundling agent is small, it is difficult to obtain the effects of the present invention related to the resin impregnation and adhesiveness. In addition, the bundling property of the synthetic fiber bundling is insufficient, which may deteriorate the handling properties. In addition, when the binding amount of the reinforcing fiber bundling agent is too large, the synthetic fiber bundle becomes too stiff, which deteriorates the handleability, or deteriorates the resin impregnation property during the molding of the composite, which is not preferable.

The synthetic fibers to which the (raw material) synthetic fiber bundle of the reinforcing fiber reinforcing agent of the present invention can be applied include carbon fibers, glass fibers, Various inorganic fibers such as ceramic fibers; Aramid Fibers, polyethylene fibers, polyethylene terephthalate fibers, polybutylene terephthalate fibers, polyethylene naphthalate fibers, poly Various organic fibers such as aryl ester fibers, polyacetal fibers, PBO fibers, polyphenylene sulfur fibers, and polyketone fibers. From the viewpoint of the physical properties of the obtained fiber-reinforced composite material, it is preferably selected from carbon fibers, aramid fibers, polyethylene fibers, polyethylene terephthalate fibers, and polybutylene terephthalate fibers. At least one of polyethylene naphthalate fiber, polyarylate fiber, polyacetal fiber, PBO fiber, polyphenylene sulfide fiber, and polyketone fiber.

[Fiber-reinforced composite material]

The fiber-reinforced composite material of the present invention contains a thermosetting matrix resin or a thermoplastic matrix resin and the aforementioned reinforcing fiber bundle. Since the reinforcing fiber bundle is treated with the reinforcing fiber bundle-forming agent of the present invention, the affinity between the reinforcing fiber bundle and the thermoplastic matrix resin is good, and the fiber-reinforced composite material is excellent in adhesion.

The fiber-reinforced composite material of the present invention contains a matrix resin and the aforementioned reinforcing fiber bundle. The reinforcing fiber bundle is treated by the sizing agent of the present invention, the sizing agent uniformly adheres, and the affinity between the reinforcing fiber bundle and the matrix resin becomes good, thereby becoming a fiber-reinforced composite material having excellent adhesion. In addition, it is possible to suppress thermal decomposition of the sizing agent during high-temperature processing, and to suppress adhesion of the matrix resin to the matrix resin due to thermal decomposition. The term “matrix resin” used herein means a matrix resin composed of a thermosetting resin or a thermoplastic resin, and may contain one type or two or more types. The thermosetting resin is not particularly limited, and examples thereof include epoxy resin, phenol resin, unsaturated polyester resin, and ethylene. Ester resin, cyanate resin, polyimide resin, etc. The thermoplastic resin is not particularly limited, and examples thereof include polyolefin resins, polyamide resins, polyester resins, polyacetal resins, ABS resins, phenoxy resins, polymethyl methacrylate resins, polyphenylene sulfide resins, and polymer resins. Etherimide resin, polyetherketone resin, etc. Among these, a thermoplastic resin is more preferable, and a polyamide resin is more preferable from the point that the adhesiveness improvement effect by the sizing agent of the present invention is higher. The so-called polyamidoresin resin is a polymer compound composed of a dibasic fatty acid and a diamine, an omega-amino acid, a lactam, or a derivative thereof, and having a plurality of amido groups in the main chain. Homopolymers or copolymers (copolymers) are also included. In addition, it may be a modified product in which a substituent is introduced into a main chain or a terminal.

These matrix resins are used for the purpose of further improving the adhesiveness with reinforcing fiber bundles, and some or all of them can be modified.

The manufacturing method of the fiber-reinforced composite material is not particularly limited, and composite injection molding based on short fibers (chopped fibers), long fiber pellets, etc. can be used, compression molding based on UD sheet, fabric sheet, etc., and other winding molding Wait for the generally known method.

The content of the synthetic fiber bundles in the fiber-reinforced composite material is also not particularly limited, and may be appropriately selected according to the type and shape of the fiber, the type of the thermoplastic matrix resin, etc., and is preferably 5 to 5 to the obtained fiber-reinforced composite material. 70% by weight, particularly preferably 20 to 60% by weight.

Examples

Hereinafter, the present invention will be specifically described by way of examples, but it is not limited to the examples described herein. The percentages (%) shown in the following examples represent "% by weight" unless otherwise specified. Measurement of each characteristic It measured by the method shown below.

The components used in the examples are as follows.

(Ingredient (A))

Acrylic resin A: (manufactured by DIC, Boncoat W-486)

Acrylic resin B: (manufactured by DIC, Boncoat AB-782-E)

(Ingredient (B))

SBR resin (styrene butadiene rubber) (manufactured by DIC, Lacstar 8215A)

NR resin (natural rubber) (made by Regitex, ULACOL)

(Ingredient (C))

Liquid Rosin Ester A: (Hariester SK-501NS manufactured by Harima Chemicals, 50 ° C, 1 atm, dried at 105 ° C for 2 hours, viscosity 300,000 mPa‧s)

Liquid rosin ester B: The viscosity of the article after drying at 50 ℃, 1atm and 105 ℃ for 2 hours, the viscosity is 45,000mPa‧s

[Example 1]

20% by weight of acrylic resin A, 40% by weight of SBR resin, and 40% by weight of liquid rosin ester A were mixed and stirred to obtain a sizing agent for reinforcing fibers of Example 1.

(Examples 2 to 10, Comparative Examples 1 to 7)

A sizing agent for reinforcing fibers was produced in the same manner as in Example 1, and the same evaluation was performed.

<Droplet strength>

Using composite material interface characteristics evaluation device HM410 (Dong Rong Industrial Co., Ltd. Co., Ltd.), and the adhesiveness was evaluated by the micro-droplet method.

Carbon fiber filaments were taken out of the carbon fiber bundles produced in the examples and comparative examples, and installed in a composite material interface characteristic evaluation device. A droplet of the melted polyimide resin T-663 (manufactured by Toyobo Co., Ltd.) was formed on a carbon fiber yarn on a device, and the sample was measured by sufficiently cooling it at room temperature. The measurement sample was set on the device again, the droplets were held by the device clips, the carbon fiber filament was advanced on the device at a speed of 0.06 mm / minute, and the maximum pull-out load when the droplet was pulled out from the carbon fiber filament was measured F.

The interface shear strength τ was calculated by the following formula to evaluate the adhesion between the carbon fiber filament and the polyamide-based resin.

Interfacial Shear Strength τ (Unit: MPa) = F / πdl

(F: maximum pull-out load d: diameter of the carbon fiber filament l: particle diameter in the pull-out direction of the droplet)

<Texture>

The sizing agent was adhered to the carbon fiber bundle (fineness 700tex, number of filaments 12,000) which was not sizing agent so that the nonvolatile content of the sizing agent adhered to 2.0% by weight. The texture of the obtained attached carbon fiber bundles (length: about 50 cm) was measured using a texture tester (HANDLE-O-METERHOM-2, manufactured by Daiei Scientific Precision Co., Ltd., with a slit width of 10 mm).

From Tables 1 and 2, it can be seen that the sizing agent for reinforcing fibers of Examples 1 to 5 contains the acrylic resin component (A), the rubber component (B), and the liquid rosin ester resin component (C ), So you can improve adhesion.

On the other hand, when there is only component (B) (Comparative Example 1), only When component (A) (Comparative Example 2), when there is only component (C) (Comparative Example 3), when there is no component (A) (Comparative Example 4), when there is no component (B) (Comparative Example 5), there is no component (C) (Comparative Example 6), the problem of this application cannot be solved.

Claims (6)

A bundling agent for reinforcing fibers, comprising a component (A) belonging to an acrylic resin, a rubber component (B), and a component (C) belonging to a liquid rosin ester resin. The bundling agent for reinforcing fibers according to item 1 of the scope of the patent application, wherein the weight ratio of the aforementioned component (C) in the non-volatile content of the bundling agent for reinforcing fibers is 20 to 80% by weight. The bundling agent for reinforcing fibers according to item 1 or 2 of the scope of the patent application, wherein the non-volatile content of the bundling agent for reinforcing fibers is solid at 20 ° C. The bundling agent for reinforcing fibers according to any one of claims 1 to 4, wherein the viscosity of the aforementioned component (C) at 50 ° C and 1 atm is 500,000 mPa · s or less. A reinforcing fiber bundle is obtained by attaching a bundler for reinforcing fibers according to any one of the claims 1 to 4 to a raw synthetic fiber bundle. A fiber-reinforced composite material comprises: a polyolefin resin and a reinforcing fiber bundle as described in item 5 of the scope of patent application.