JPWO2016208306A1 - Reinforcing fiber sizing agent and use thereof - Google Patents

Abstract

A sizing agent for reinforcing fibers having excellent heat resistance and a high viscosity at high temperature, and a reinforcing fiber provided with the sizing agent are provided. A sizing agent for reinforcing fibers comprising at least one selected from the following components (I) and (II): Component (I): a compound obtained by reacting a titanium compound (A) and a compound (B) having an active hydrogen group, Component (II): a titanium compound (A) and a compound (B) having an active hydrogen group. The compound (B) preferably contains a compound (B1) having a hydroxyl group. The compound (B1) preferably contains at least one selected from an epoxy resin, a polyester resin, a urethane resin, and a polyether polyol resin.

Description

  The present invention relates to a reinforcing fiber obtained by applying a reinforcing fiber sizing agent and a reinforcing fiber sizing agent.

By applying the sizing agent to the fiber, it is possible to impart various characteristics such as increasing the convergence and smoothly proceeding the production process, adjusting the texture of the produced fiber, and imparting a function to the fiber. Among these characteristics, convergence is one of the most important performances for improving production efficiency and quality, and is greatly influenced by the viscosity of the sizing agent. When the viscosity is low, the convergence is low and defects such as fiber fluffing occur. May occur. Therefore, as described in Patent Document 1, it is very important to increase the viscosity of the sizing agent in order to improve the convergence.
The sizing agent for reinforcing fibers is applied to the surface of the reinforcing fibers, facilitates the manufacturing process of the reinforcing fibers, and facilitates the handling of the manufactured reinforcing fibers. It plays various roles such as linking the reinforcing fibers and the matrix resin when the resin is impregnated with the reinforcing fibers. One of the required performances required for these sizing agents is heat resistance. When FRP of sized carbon fibers or the like is performed with a matrix resin, there are many cases in which a matrix resin is cured at a high temperature or a resin melted at a high temperature is used.
At this time, when the sizing agent is decomposed by heat, a decrease in the adhesion between the carbon fibers and the matrix resin and the decomposition product are vaporized to generate voids, which may result in an FRP less than the desired physical property value. In addition, since the FRP is exposed to a high temperature environment as described above, if the viscosity of the sizing agent is low at a high temperature, the carbon fiber may be excessively dispersed and the predetermined performance may not be exhibited. .

International Publication No. 2013/146024

  An object of the present invention is to provide a reinforcing fiber sizing agent having excellent heat resistance and high viscosity at high temperature, and a reinforcing fiber to which the sizing agent is applied.

As a result of intensive studies, the present inventors have found that the above problems can be solved by at least one selected from the specific component (I) and the specific component (II), and have reached the present invention.
That is, this invention is a sizing agent for reinforcement fibers containing at least 1 sort (s) chosen from the following component (I) and the following component (II).
Component (I): Compound obtained by reacting a titanium compound (A) and a compound (B) having an active hydrogen group Component (II): Titanium compound (A) and a compound (B) having an active hydrogen group

The compound (B) preferably contains a compound (B1) having a hydroxyl group.
The compound (B1) preferably contains at least one selected from an epoxy resin, a polyester resin, a urethane resin, and a polyether polyol resin.
The component (II) preferably satisfies the following condition 1.
Condition 1: The weight ratio (A / B) of the compound (A) to the compound (B) is 0.001 to 10% by weight.
The compound (A) is preferably represented by the following general formula (1).
(In the formula, R ^{1 to} R ⁴ are organic groups, which may be the same or different. N is an integer of 1 or more.)
The organic group is an alkyl group having 2 to 8 carbon atoms, and the n is preferably 1.
It is preferable to further contain a smoothing agent (C).

The reinforcing fiber strand of the present invention is formed by adhering the reinforcing fiber sizing agent to the raw material reinforcing fiber strand.
The fiber-reinforced composite material of the present invention includes a matrix resin and the reinforcing fiber strand.

  Since the sizing agent for reinforcing fibers of the present invention is excellent in bundling property and heat resistance, there is little decomposition at high temperature, and since the viscosity at high temperature is high, the reinforcing fiber is less likely to be broken and has excellent FRP strength.

  The sizing agent for reinforcing fibers of the present invention contains at least one selected from the above component (I) and the above component (II). Since both component (I) and component (II) are components derived from the titanium compound (A) and the compound (B) having an active hydrogen group, first, the component has a titanium compound (A) and an active hydrogen group. The compound (B) will be described.

[Titanium compound (A)]
The titanium compound (A) is a compound containing a titanium atom in the molecule, and reacts or is used in combination with a compound (B) having an active hydrogen group, which will be described later, whereby the active hydrogen group of the compound (B) is crosslinked or mutually bonded. It acts to improve the viscosity and heat resistance of the reinforcing fiber sizing agent.
Although it will not specifically limit as said compound (A) if it bridge | crosslinks with an active hydrogen group, An organic titanium compound and / or an inorganic titanium compound are mentioned.

  The organic titanium compound is an organometallic compound in which a titanium atom is bonded to an organic group through oxygen (oxygen atom), and examples thereof include alkoxides, chelates, acylates, carboxylic acids, and amines. It is done.

  Examples of alkoxides include tetramethoxy titanium, tetraethoxy titanium, tetraisopropoxy titanium, tetra n-propoxy titanium, tetra n-butoxy titanium, tetraisobutoxy titanium, tetra sec-butoxy titanium, tetra tert-butoxy titanium, tetra (2 -Ethylhexyl) titanate, tetracyclohexyl titanate, tetraoctadecyl titanate, tetraphenyl titanate, tetrabenzyl titanate, triisopropoxyisopropyl titanium, trinormal butoxy normal butyl titanium, trinormal butoxy titanium monostearate and the like.

The alkoxide is preferably represented by the general formula (1) from the viewpoint of improving heat resistance because crosslinking with a hydroxyl group is likely to occur.
In general formula (1), R ^{1 to} R ⁴ are organic groups, which may be the same or different. n is an integer of 1 or more.
Said R < ¹ > -R < ⁴ > is at least 1 sort (s) chosen from a C1-C8 alkyl group, a C3-C8 alkenyl group, and a C6-C10 aryl group from a viewpoint of heat resistance improvement. Is preferred. More preferably, an alkyl group having 2 to 4 carbon atoms is preferable.
When n is 1, it is preferable from the viewpoint of easily causing a crosslinking reaction and extremely improving heat resistance.
The preferable upper limit of n is 4. If it exceeds 4, the compatibility with the compound (B) having an active hydrogen group used in combination may be lowered, and the stability of the reinforcing fiber sizing agent may be lowered.

  Examples of chelates include diisopropoxy titanium bis (methyl acetoacetate), diisopropoxy titanium bis (ethyl acetoacetate), diisopropoxy titanium bis (propyl acetoacetate), diisopropoxy titanium bis (butyl acetoacetate), diisopropoxy titanium bis ( Hexyl acetoacetate), di n-propoxy titanium bis (methyl acetoacetate), di n-propoxy titanium bis (ethyl acetoacetate), di n-propoxy titanium bis (propyl acetoacetate), di n-propoxytitanium bis (butyl acetoacetate), di n-propoxy titanium bis (hexyl acetoacetate), di n-butoxy titanium bis (methyl acetoacetate), di n-butoxy titanium bis (ethyl acetoacetate) ), Di n-butoxy titanium bis (propyl acetoacetate), di n-butoxy titanium bis (butyl acetoacetate), di n-butoxy titanium bis (hexyl acetoacetate), 1,3-propanedioxytitanium bis (ethyl acetoacetate), di Isopropoxytitanium bis (acetylacetonate), di-n-propoxytitanium bis (acetylacetonate), di-n-butoxytitanium bis (acetylacetonate), titanium tetraacetylacetonate, titanium tetraethyl acetoacetate, titanium tetrapropyl acetoacetate, titanium tetra Examples include butyl acetoacetate.

  Examples of acylates include tri-n-butoxy titanium monostearate, diisopropoxy titanium distearate, titanium stearate, diisopropoxy titanium, diisostearate (2-n-butoxycarbonylbenzoyloxy) tributoxy titanium, etc. Is mentioned.

  Examples of carboxylic acids include trimellitic acid titanium, titanium tetraacetate, titanium triacetate, titanium tetrabutyrate, titanium tributyrate, tetrakis lactate, titanium citrate, titanium oxalate, titanium potassium oxalate, and sodium sodium oxalate.

  The inorganic titanium compound is not particularly limited as long as it reacts with an active hydrogen group, and examples thereof include titanium chloride.

[Compound (B) having an active hydrogen group]
When the compound (B) having an active hydrogen group is reacted with or combined with the compound (A), the active hydrogen groups interact with each other through crosslinking or a titanium compound, and the viscosity of the sizing agent is improved.

  The compound (B) having an active hydrogen group is not particularly limited, but a compound (B1) having a hydroxyl group, a compound (B2) having an amino group, a compound (B3) having a carboxyl group, a compound having a thiol group ( B4) and a compound (B5) having a phosphoric acid group, and among them, a compound (B1) having a hydroxyl group is preferable from the viewpoint of being easily cross-linked with the compound (A) and improving viscosity at high temperature and excellent heat resistance. .

The compound having a hydroxyl group (B1) is not particularly limited as long as it has a hydroxyl group, but is an aliphatic hydroxyl group-containing compound, an aromatic hydroxyl group-containing compound, an epoxy resin, a polyester resin, a urethane resin, a polyether polyol resin, and a polycarbonate polyol resin. , A polybutadiene polyol resin, a polyacryl polyol resin, a polybutadiene polyol resin, a hydrogenated polybutadiene resin, a castor oil-based polyol resin, a compound having a hydroxyl group such as polyvinyl alcohol, or a polymer.
Among them, epoxy resin, polyester resin, urethane resin and polyether polyol resin are preferable from the viewpoint of improving viscosity and heat resistance, and because they are easy to react with the compound (A), from the viewpoint of improving viscosity and heat resistance, An epoxy resin is more preferable.

The aliphatic hydroxyl group-containing compound is not particularly limited, and examples thereof include glycerin, trimethylolpropane, pentaerythritol, diglycerin, α-methylglucoside, sorbitol, xylit, mannitol, dipentaerythritol, glucose, fructose, sucrose, and the like. It is done.
The aromatic hydroxyl group-containing compound is not particularly limited, and examples thereof include pyroganol, catechol, hydroquinone, bisphenol A, bisphenol F, and bisphenol S.

  An epoxy resin is a compound having two or more reactive epoxy groups in the molecular structure. The epoxy resin is typically a glycidyl ether type obtained from epichlorohydrin and an active hydrogen compound, and other examples include glycidyl ester type, glycidyl amine type, and alicyclic type. The epoxy resin may be used alone or in combination of two or more.

  The epoxy resin is not particularly limited as long as it has a hydroxyl group. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, alkylphenol Examples thereof include novolac type epoxy resins, biphenyl type epoxy resins, dicyclopentadiene type epoxy resins, naphthalene type epoxy resins, and various modified epoxy resins such as amine-modified aromatic epoxy resins.

  Among these, an epoxy resin having a repeating unit represented by the following chemical formula (2) is particularly preferable from the viewpoint of improving viscosity and heat resistance.

(In formula (2), R ¹ , R ² , R ³ and R ⁴ are each independently a hydrogen atom or a methyl group. N1 is an integer of 1 or more.)

  The epoxy equivalent of the epoxy resin is preferably 100 to 1500 g / eq, more preferably 120 to 1000 g / eq, and further preferably 150 to 800 g / eq. When the epoxy equivalent is less than 100 g / eq, curing of the reinforcing fiber strand with time may be promoted. When the epoxy equivalent is more than 1500 g / eq, the adhesion with the matrix resin may be lowered. In addition, an epoxy equivalent means the thing based on JIS-K7236.

  100-10000 are preferable, as for the weight average molecular weight of an epoxy resin, 100-8000 are more preferable, and 150-7000 are further more preferable. When the weight average molecular weight is less than 100, the heat resistance may be insufficient and volatilize in the drying step of the reinforcing fiber strand. When the weight average molecular weight exceeds 10,000, the long-term storage stability of the sizing agent may be lowered.

The polyester resin is not particularly limited, but has a structure in which polycarboxylic acid or an anhydride thereof and a polyol are dehydrated and condensed, and has at least one hydroxyl group in the molecule.
Examples of the polycarboxylic acid include aromatic dicarboxylic acids, sulfonate-containing aromatic dicarboxylic acids, aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, and trifunctional or higher functional polycarboxylic acids.

Examples of the aromatic dicarboxylic acid include phthalic acid, terephthalic acid, isophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid, and phthalic anhydride.
Examples of the sulfonate-containing aromatic dicarboxylic acid include sulfoterephthalate and 5-sulfoisophthalate.
As aliphatic dicarboxylic acid or alicyclic dicarboxylic acid, fumaric acid, maleic acid, itaconic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, 1,4-cyclohexanedicarboxylic acid, succinic anhydride, anhydrous And maleic acid.
Examples of the tri- or higher functional polycarboxylic acid include trimellitic acid, pyromellitic acid, trimellitic anhydride, pyromellitic anhydride, and the like.

Examples of the polyol include diols and trifunctional or higher functional polyols.
Diols include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, polybutylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, tetramethylene glycol 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, resorcin, hydroquinone, bisphenol A or an alkylene oxide adduct thereof.
Examples of the trifunctional or higher functional polyol include trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, ditrimethylolpropane, and the like.
Also, a resin having the above hydroxyl group can be used.

  The hydroxyl value of the polyester resin is preferably 10 to 250 mgKOH / g, more preferably 15 to 150 mgKOH / g, and still more preferably 30 to 120 mgKOH / g. The hydroxyl value was measured according to JIS K 1557-1970.

The number average molecular weight of the polyester resin is preferably 500 to 10,000, more preferably 700 to 8000, and still more preferably 1000 to 4000. In addition, the number average molecular weight as used in the field of this invention was computed from the said hydroxyl value.
The polyester resin can be obtained by a method similar to a known polyester production method by dehydrating and condensing the above polycarboxylic acid or its anhydride and the above polyol.

The polyurethane resin is not particularly limited as long as it is a reaction product mainly composed of a known polyisocyanate and a known polyol.
The polyisocyanate may be an aromatic polyisocyanate compound or an aliphatic polyisocyanate compound.
Examples of the aromatic polyisocyanate compound include tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, xylene diisocyanate, naphthylene-1,5-diisocyanate, mono- or dichlorophenylene-2,4-diisocyanate, diphenylmethane- 4,4′-diisocyanate, 3,3′-dimethyldiphenylmethane-4,4′-diisocyanate, 3-methyldiphenylmethane-4,4′-diisocyanate, metaphenylene-diisocyanate, paraphenylene-diisocyanate, triphenylmethane triisocyanate, etc. Can be mentioned.
Examples of the aliphatic polyisocyanate compound include 1,6-hexamethylene diisocyanate, propyl diisocyanate, and butyl diisocyanate. As the polyisocyanate compound, the polyisocyanate compounds exemplified above may be used alone or in combination of two or more.
Examples of the polyol include polyether polyols such as polyethylene glycol, polypropylene glycol, ethylene oxide and / or propylene oxide adducts of bisphenol A, and polyesters that are condensates of polybasic acids such as succinic acid, adipic acid, and phthalic acid. Examples thereof include polyols having a carboxyl group and a sulfonic acid group such as 2,2-dimethylolpropionic acid and 1,4-butanediol-2-sulfonic acid, and polyol compounds exemplified as a constituent component of a polyester resin. .

  The polyether polyol resin is not particularly limited, but includes polyethylene glycol, polypropylene glycol, polybutylene glycol, polytetramethylene glycol, polyethylene glycol / polypropylene glycol block copolymer, polyethylene glycol / polypropylene glycol random copolymer, and bisphenol A. Examples include various polyether adducts and various polyether adducts of hydrogenated castor oil.

  The polycarbonate polyol resin is not particularly limited, and examples thereof include polyethylene carbonate diol, polypropylene carbonate, polybutylene carbonate diol, polypentamethylene carbonate diol, polyhexamethylene carbonate diol, and copolymers thereof.

  The polyacryl polyol resin is not particularly limited as long as it is synthesized from a known acrylic monomer and a polymerization initiator, but those having a hydroxyl group in the side chain of the polyacryl resin or those having a hydroxyl group introduced at both ends are used. Can be mentioned.

  Although it does not specifically limit as a compound (B2) which has an amino group, Polyamide compound, polyoxyalkyleneamine, ethylenediamine, diethylenetriamine, trimethylenetetramine, tetramethylenepentamine, propanediamine, butanediamine, pentanediamine, hexanediamine, isophorone Examples include diamine, metaxylylenediamine, norbornanediamine, and the like.

  Examples of the compound (B3) having a carboxyl group include the same compounds as the polycarboxylic acid.

  Although it does not specifically limit as a compound (B4) which has a thiol group, A polysulfide polymer etc. are mentioned.

  Examples of the compound (B5) having a phosphate group include organic phosphates, and specific examples thereof include, but are not limited to, lauryl phosphate, cetyl phosphate, oleyl phosphate, POE lauryl phosphate, POE cetyl phosphate, POE oleyl. Phosphate, and the like.

[Sizing agent for reinforcing fibers]
The sizing agent for reinforcing fibers of the present invention contains at least one selected from the following component (I) and the following component (II).
Component (I): Compound obtained by reacting a titanium compound (A) and a compound (B) having an active hydrogen group Component (II): Titanium compound (A) and a compound (B) having an active hydrogen group
In Component (I), the titanium compound (A) and the compound (B) having an active hydrogen group react to increase the molecular weight, thereby increasing the viscosity of the sizing agent and being excellent in heat resistance. Component (II) is excellent in heat resistance because the viscosity of the sizing agent is increased by the interaction between the titanium compound (A) and the compound (B) having an active hydrogen group.
The component (I) and the component (II) are obtained by blending the titanium compound (A) and the compound (B) having an active hydrogen group, but the titanium compound (A) and the compound (B) having an active hydrogen group. The blending ratio (A / B) is not particularly limited, but is preferably 0.001 to 10% by weight, more preferably 0.01 to 5% by weight, and 0.2 to 3% by weight from the viewpoint of exerting the effect of the present application. % Is more preferable.

The weight ratio of titanium atoms in the nonvolatile content of the sizing agent for reinforcing fibers is not particularly limited, but is preferably 0.00004 to 3% by weight, more preferably 0.0004 to 2.7% by weight, and 0.004 to 2.4% by weight is more preferable, and 0.02 to 2.1% by weight is particularly preferable. If it is less than 0.00004, the effect of the present application may not be exhibited. On the other hand, if it exceeds 3, the effect of the present application may not be exhibited.
In addition, the weight ratio of the titanium atom to the non-volatile content of the sizing agent for reinforcing fibers means a value measured by the ICP method.

  0.001-10 weight% is preferable, as for the weight ratio of the said compound (A) to the non volatile matter of component (II), 0.01-9 weight% is more preferable, 0.1-8 weight% is further more preferable. 0.5 to 7% by weight is particularly preferable. If the amount is less than 0.001% by weight, the effect of the present application may not be exhibited. If the amount exceeds 10% by weight, the thickening effect by the crosslinking reaction may be too high, and thus kneading may not be possible.

  The weight ratio of the compound (B) in the nonvolatile content of the component (II) is preferably 20 to 99.999% by weight, more preferably 40 to 99.99% by weight, and further preferably 50 to 99.9% by weight. 60-99.5% by weight is particularly preferred. If it is less than 20% by weight, the effect of the present application may not be exhibited, and if it exceeds 99.999% by weight, the effect of the present application may not be exhibited.

  In the component (II), the weight ratio (A / B) of the compound (A) to the compound (B) is preferably 0.001 to 10% by weight, more preferably 0.01 to 9% by weight, and 1 to 8% by weight is more preferable, and 0.5 to 7% by weight is particularly preferable. If the amount is less than 0.001% by weight, the effect of the present application may not be exhibited. If the amount exceeds 10% by weight, the thickening effect by the crosslinking reaction may be too high, and thus kneading may not be possible.

  The sizing agent for reinforcing fibers of the present invention can be used in a state dispersed or dissolved in an organic solvent such as acetone or methyl ethyl ketone, but it is safe for the human body during handling, disaster prevention such as fire, natural From the viewpoint of prevention of environmental pollution, etc., it may further contain water, and the neutralized product and the polymer component (A) may be dispersed in water (aqueous dispersion) or dissolved in water (aqueous solution). preferable.

  The method for producing the sizing agent for reinforcing fibers of the present invention as an aqueous dispersion or aqueous solution is not particularly limited, and a known method can be employed. For example, each component that constitutes the sizing agent for reinforcing fibers is poured into warm water under stirring and emulsified, dispersed or dissolved, and each component that constitutes the sizing agent for reinforcing fibers is mixed, and the resulting mixture is softened Examples include a method in which water is gradually added and water is gradually added while applying mechanical shearing force using a homogenizer, a homomixer, a ball mill or the like after warming to a point or higher.

In addition, the water dispersion or the aqueous solution is not limited to water such as an organic solvent within the range that does not impair the advantages of the water dispersion and the aqueous solution for the purpose of improving the operability during production and the stability of the aqueous dispersion over time. The solvent can be contained.
Examples of the organic solvent include alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; glycols or glycol ethers such as ethylene glycol, propylene glycol, ethylene glycol monoisopropyl ether, and ethylene glycol monobutyl ether; ketones such as acetone and methyl ethyl ketone. It can be illustrated. Although the content depends on the type of solvent, in order not to impair the advantages of the aqueous dispersion and aqueous solution, the content is preferably 100% by weight or less, and 50% by weight or less based on the nonvolatile content of the sizing agent for reinforcing fibers Further preferred.

When the sizing agent for reinforcing fibers of the present invention is an aqueous dispersion or an aqueous solution, the concentration of the non-volatile content is not particularly limited, and the stability as an aqueous dispersion is determined by the non-volatile composition of the sizing agent for reinforcing fibers. In consideration of the viscosity, etc., which is easy to handle as a product, it is appropriately selected, but considering the transportation cost of the product, it is preferably 10% by weight or more, more preferably 20-60% by weight, and more preferably 30-50% by weight. Is particularly preferred.
Examples of components other than those described above constituting the sizing agent for reinforcing fibers of the present invention include various surfactants, various antioxidants, flame retardants, antibacterial agents, crystal nucleating agents, antifoaming agents, and the like. be able to. These may be used alone or in combination of two or more.

In particular, when the surfactant has a resin component that is water-insoluble or hardly soluble in the reinforcing fiber sizing agent of the present invention, the surfactant can be used as an emulsifier to efficiently carry out aqueous emulsification. Therefore, the sizing agent for reinforcing fibers can be made into an aqueous dispersion. The weight ratio of the entire non-volatile content when using the surfactant is preferably 5 to 40% by weight, more preferably 10 to 30% by weight, and still more preferably 15 to 25% by weight.
The surfactant is not particularly limited, and a known one can be appropriately selected from nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants. Surfactant may use together 1 type (s) or 2 or more types.

Nonionic surfactants include, for example, alkylene oxide-added nonionic surfactants (higher alcohols, higher fatty acids, alkylphenols, styrenated phenols, benzylphenols, sorbitans, sorbitan esters, castor oil, hydrogenated castor oil, etc. And alkylene oxides such as oxides and propylene oxides (two or more types can be used together), polyalkylene glycols added with higher fatty acids, and ethylene oxide / propylene oxide copolymers. .
Examples of the anionic surfactant include carboxylic acid (salt), sulfate ester salt of higher alcohol / higher alcohol ether, sulfonate salt, phosphate ester salt of higher alcohol / higher alcohol ether, and the like.

Examples of cationic surfactants include quaternary ammonium salt type cationic surfactants (such as lauryltrimethylammonium chloride and oleylmethylethylammonium etosulphate), amine salt type cationic surfactants (polyoxyethylene laurylamine), and the like. Lactate etc.).
Examples of amphoteric surfactants include amino acid type amphoteric surfactants (such as sodium laurylaminopropionate), betaine type amphoteric surfactants (such as stearyl dimethyl betaine, lauryl dihydroxyethyl betaine), and the like.

  The sizing agent for reinforcing fibers of the present invention can be used in combination with a resin having no hydroxyl group as long as the performance is not impaired. Specific examples include polyethylene resin, polypropylene resin, polybutadiene resin, polyamide resin, polyimide resin, acrylic resin, styrene resin, nylon resin, and polyester resin.

[Smoothing agent (C)]
Since the sizing agent for reinforcing fibers of the present invention further contains a smoothing agent (C), it is preferable because it has excellent scratch resistance.
The smoothing agent (C) is not particularly limited as long as it exhibits smoothness, and examples thereof include ester compounds and sulfur-containing ester compounds having a structure in which an aliphatic alcohol and a fatty acid are ester-bonded.

  Examples of the ester compound include, but are not limited to, 2-decyltetradecanoyl erucinate, 2-decyltetradecanoyl oleate, 2-octyldodecyl stearate, isooctyl palmitate, isooctyl stearate, butyl palmitate , Butyl stearate, butyl oleate, isooctyl oleate, lauryl oleate, isotridecyl stearate, hexadecyl stearate, isostearyl oleate, oleyl octanoate, oleyl laurate, oleyl palmitate, oleyl stearate Oleyl oleate and the like. Among these, 2-decyltetradecanoyl oleate, 2-octyldodecyl stearate, isooctyl palmitate, isooctyl stearate, lauryl oleate, isotridecyl stearate, hexadecyl stearate, isostearyl oleate, Oleyl oleate, trimethylolpropane tricaprylate, trimethylolpropane tricaprinate, trimethylolpropane trilaurate, trimethylolpropane trioleate, trimethylolpropane (laurate, myristylate, palmitate), trimethylolpropane (laurate, myristylate, Oleate), trimethylolpropane (tripalm fatty acid ester), trimethylolpropane (tricoconut fatty acid ester), palm oil, rapeseed , Palm oil, glycerol trilaurate, glycerol trioleate, glycerol triisostearate, sorbitan trioleate, sorbitan (laurate, myristylate, oleate), pentaerythritol tetracaprylate, pentaerythritol tetracaprinate, pentaerythritol tetralaurate, Erythritol tetralaurate, pentaerythritol (tetrapalmyl fatty acid ester), pentaerythritol (tetracoconut fatty acid ester), 1,6-hexanediol dioleate, dioctyl adipate, dilauryl adipate, dioleyl adipate, diisocetyl adipate, sebacine Dioctyl acid, dilauryl sebacate, dioleyl sebacate, diisocetyl sebacate, dithiodiethanoic acid n-dodecyl) ester, thiodiethanic acid di (n-tridecyl) ester, thiodiethanic acid di (n-tetradecyl) ester, thiodiethanic acid di (n-pentadecyl) ester, thiodiethanic acid di (n-hexadecyl) ester, thiodiethanic acid di ( Thiodietanic acid di-linear ester such as oleyl ester; thiodiethanic acid di (isododecyl) ester, thiodiethanic acid di (isotridecyl) ester, thiodiethanic acid di (isotetradecyl) ester, thiodiethanic acid di (isopentadecyl) ester, thiodieethane Di (isohexadecyl) acid ester, di (2-hexyldecyl) thiodiethanate ester, di (isostearyl) thiodiethanate ester, etc .; di (n-dodecyl) thiodipropionate; Ester, thiodipropionic acid di (n-tridecyl) ester, thiodipropionic acid di (n-tetradecyl) ester, thiodipropionic acid di (n-pentadecyl) ester, thiodipropionic acid di (n-hexadecyl) ester, Thiodipropionic acid di-linear ester such as di (oleyl) ester; thiodipropionic acid di (isododecyl) ester, thiodipropionic acid di (isotridecyl) ester, thiodipropionic acid di (isotetradecyl) ) Ester, thiodipropionic acid di (isopentadecyl) ester, thiodipropionic acid di (isohexadecyl) ester, thiodipropionic acid di (2-hexyldecyl) ester, thiodipropionic acid di (isostearyl) ester Di-branched thiodipropionic acid Thiodibutanoic acid di (n-dodecyl) ester, thiodibutanoic acid di (n-tridecyl) ester, thiodibutanoic acid di (n-tetradecyl) ester, thiodibutanoic acid di (n-pentadecyl) ester, thiodibutanoic acid di (n-hexadecyl) Esters, thiodibutanoic acid di (oleyl) ester and other thiodibutanoic acid di linear esters; thiodibutanoic acid di (isododecyl) ester, thiodibutanoic acid di (isotridecyl) ester, thiodibutanoic acid di (isotetradecyl) ester, thiodibutanoic acid di (iso Thiodibutanoic acid di (isohexadecyl) ester, thiodibutanoic acid di (2-hexyldecyl) ester, thiodibutanoic acid di (isostearyl) ester, etc. Acid di (n-dodecyl) ester, thiodipentanoic acid di (n-tridecyl) ester, thiodipentanoic acid di (n-tetradecyl) ester, thiodipentanoic acid di (n-pentadecyl) ester, thiodipentanoic acid di (n-hexadecyl) ester, thiodipentane Thiodipentanoic acid di linear ester such as acid di (oleyl) ester; thiodipentanoic acid di (isododecyl) ester, thiodipentanoic acid di (isotridecyl) ester, thiodipentanoic acid di (isotetradecyl) ester, thiodipentanoic acid di (isopentadecyl) Thiodipentanoic acid dibranched esters such as esters, thiodipentanoic acid di (isohexadecyl) ester, thiodipentanoic acid di (2-hexyldecyl) ester, thiodipentanoic acid di (isostearyl) ester; Preference is given to esters with thioether monocarboxylic acids such as xanthdiol dioctadecyl thiopropionate, trimethylolpropane tridodecyl thiopropionate, glycerol tridodecyl thiopropionate, pentaerythritol tetraoctadecyl thiopropionate.

  The ester compound can be synthesized and obtained by a known method using a commercially available fatty acid, aliphatic alcohol, or sulfur-containing compound.

[Reinforcing fiber strand]
The reinforcing fiber strand of the present invention is a reinforcing fiber for reinforcing the thermoplastic matrix resin by adhering the sizing agent for reinforcing fiber to the raw synthetic fiber strand.

The manufacturing method of the reinforced fiber strand of this invention is a manufacturing method including the sizing process process which makes the sizing agent for reinforcing fibers adhere to a raw material synthetic fiber strand, and dries the obtained deposit.
The method for attaching the reinforcing fiber sizing agent to the raw synthetic fiber strand to obtain the deposit is not particularly limited, but the reinforcing fiber sizing agent is a kiss roller method, roller dipping method, spray method or other known methods, Any method may be used as long as it is attached to the raw synthetic fiber strand. Among these methods, the roller dipping method is preferable because the sizing agent for reinforcing fibers can be uniformly attached to the raw synthetic fiber strand.
There is no limitation in particular about the drying method of the obtained deposit, For example, it can heat-dry with a heating roller, a hot air, a hot plate, etc.

  In adhering the reinforcing fiber sizing agent to the raw synthetic fiber strand, all components of the reinforcing fiber sizing agent may be adhered after mixing, or the components are separately divided into two or more stages. May be attached. In addition, the thermosetting resin such as epoxy resin, vinyl ester resin, phenol resin and / or polyolefin resin other than the polymer component of the present invention, nylon resin, polycarbonate resin, polyester resin, as long as the effect of the present invention is not impaired. Thermoplastic resins such as polyacetal resin, ABS resin, phenoxy resin, polymethyl methacrylate resin, polyphenylene sulfide resin, polyetherimide resin, polyether ketone resin may be attached to the raw synthetic fiber strand.

  The reinforcing fiber strand of the present invention is used as a reinforcing fiber of a composite material using various thermoplastic resins as a matrix resin, and the form to be used may be a continuous fiber state or a state cut to a predetermined length.

The adhering amount of the non-volatile content of the reinforcing fiber sizing agent to the raw synthetic fiber strand can be selected as appropriate, and the adhering amount may be a necessary amount for the synthetic fiber strand to have a desired function. The content is preferably 0.1 to 20% by weight. In the synthetic fiber strand in a continuous fiber state, the adhesion amount is more preferably 0.1 to 10% by weight, and further preferably 0.5 to 5% by weight with respect to the raw material synthetic fiber strand. Moreover, in the strand cut | disconnected by the predetermined length, 0.5 to 20 weight% is more preferable, and 1 to 10 weight% is further more preferable.
When the adhesion amount of the reinforcing fiber sizing agent is small, it is difficult to obtain the effects of the present invention relating to the resin impregnation property and adhesiveness, and the converging property of the synthetic fiber strand is insufficient, and the handling property may be deteriorated. Further, if the adhesion amount of the reinforcing fiber sizing agent is too large, the synthetic fiber strand is too stiff, and on the contrary, the handling property may be deteriorated, or the resin impregnation property may be deteriorated at the time of composite molding. Absent.

  The synthetic fiber of the synthetic fiber strand to which the sizing agent for reinforcing fiber of the present invention can be applied includes various inorganic fibers such as carbon fiber, glass fiber and ceramic fiber, aramid fiber, polyethylene fiber, polyethylene terephthalate fiber, polybutylene Examples of the organic fiber include terephthalate fiber, polyethylene naphthalate fiber, polyarylate fiber, polyacetal fiber, PBO fiber, polyphenylene sulfide fiber, and polyketone fiber. Carbon fiber, aramid fiber, polyethylene fiber, polyethylene terephthalate fiber, polybutylene terephthalate fiber, polyethylene naphthalate fiber, polyarylate fiber, polyacetal fiber, PBO fiber, polyphenylene sulfide fiber from the viewpoint of physical properties as the resulting fiber reinforced composite material And at least one selected from polyketone fibers is preferred.

[Fiber-reinforced composite materials]
The fiber-reinforced composite material of the present invention includes a matrix resin and the above-described reinforcing fiber strand. Here, the matrix resin refers to a base material that holds the reinforcing fibers of the fiber-reinforced composite material. Since the reinforcing fiber strands are treated with the reinforcing fiber sizing agent of the present invention, the affinity with the reinforcing fiber strands and the matrix resin is good, and a fiber-reinforced composite material having excellent adhesion is obtained.
Here, the matrix resin refers to a matrix resin composed of a thermosetting resin and / or a thermoplastic resin, and is not particularly limited, and a known matrix resin can be appropriately selected and used. The above may be included.
The thermosetting matrix resin is not particularly limited, and examples thereof include an epoxy resin, an unsaturated polyester resin, a vinyl ester resin, a benzoxazine resin, a phenol resin, a urea resin, a melamine resin, and a thermosetting polyimide resin. it can.
The thermoplastic matrix resin is not particularly limited. For example, polyolefin resin, nylon resin, polycarbonate resin, polyester resin, polyacetal resin, ABS resin, phenoxy resin, polymethyl methacrylate resin, polyphenylene sulfide resin, polyetherimide resin, Examples include polyether ketone resins. These thermoplastic matrix resins may be partially or wholly modified for the purpose of further improving the adhesion to the synthetic fiber strand.
The method for producing the fiber reinforced composite material is not particularly limited, and known methods such as compound injection molding using chopped fibers and long fiber pellets, press molding using UD sheets and woven sheets, and other filament winding molding can be employed.
The content of the synthetic fiber strand in the fiber reinforced composite material is not particularly limited, and may be appropriately selected according to the type of fiber, the form, the type of thermoplastic matrix resin, etc. 5 to 70% by weight is preferable, and 20 to 60% by weight is more preferable.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, it is not limited to the Example described here. The percent (%) shown in the following examples represents “% by weight” unless otherwise specified. Each characteristic value was measured based on the following method.

<Viscosity>
In order to investigate the thickening effect of the compound (A) and the compound (B), the viscosity was measured. It measured at each temperature of 50 degreeC, 75 degreeC, and 100 degreeC using the corn plate type viscometer (the product made by RESEARCH EQUIIPMENT, IC CON & PLATE VISCOMETER). Based on the following indicators, ◎ and ○ were accepted.
Compared to the sizing agent that does not contain compound (A),
A: When 10 times or more B: When over 1.2 times and less than 10 times <Convergence>
It was visually evaluated whether or not 10 pieces of carbon fiber sized with each sizing agent (diluted to 3% with water, adhesion rate 1%) were cut out with a cutter knife at a length of 5 mm. Judgment was made based on the following evaluation criteria, and ○ was regarded as acceptable.
○: 2 or less loosening Δ: 7 to 3 loosening ×: 8 or more loosening <heat resistance>
The sizing agent is heat-treated at 105 ° C. to remove the solvent and the like and reach a constant weight to obtain a non-volatile content of the sizing agent. About 4 mg of the obtained non-volatile content was put on an aluminum pan having a known weight, and the weight (W1) was measured. The non-volatile content in the aluminum pan is set on a differential thermobalance TG-8120 (manufactured by Rigaku Corporation), heated from 25 ° C. to 500 ° C. at a heating rate of 20 ° C./min, and weight at 300 ° C. (W2) was measured. Thereafter, the weight loss rate was calculated by the following formula. Based on the following indicators, ◎ and ○ were accepted.
Weight reduction rate (%) = ((W1-W2) / W1) × 100
The weight reduction rate of the index is compared with the weight reduction rate of the sizing agent with no addition of the compound (A),
◎: When less than 1/10 ◯: When less than 8/10 to 1/10 In addition, the non-volatile content in this specification is a heat treatment at 105 ° C. to remove the solvent, etc., to reach a constant weight. Means things.

(Examples 1-11, Comparative Examples 1-4)
Sizing for reinforcing fibers according to Examples 1 to 11 and Comparative Examples 1 to 4 are carried out using the components (A-1 to D-3) shown below and mixing at the ratios (parts by weight) shown in Tables 1 to 6. Each agent was obtained. The results are shown in Tables 1-4.
A-1 Tetraethoxytitanium A-2 Tetraisopropoxytitanium A-3 Tetrabutoxytitanium A-4 Tetraisopropylglycoxytitanium A-5 Tetrabutoxytitanium tetramer B-1 Liquid epoxy resin (JER-828 Molecular weight: 380, Mitsubishi Chemical) (Made by company, molecules with hydroxyl groups are contained in a ratio of 1 molecule per 10 molecules)
B-2 Solid epoxy resin (JER-1001 molecular weight: 900, manufactured by Mitsubishi Chemical Corporation)
B-3 Polyester polymerized from 2 mol of PEG / maleic anhydride on both ends of Bis-A (acid value: 4.6 KOHmg / g)
B-4 PTMG (polytetramethylene glycol, molecular weight 2000) and HDI (hexamethylene diisocyanate) reacted at 2: 1 (molar ratio).
B-5 Duranol T-5562 manufactured by Asahi Kasei Chemicals Corporation C-1 oleyl oleate D-1 150 mol addition-cured castor oil ether (polyether polyol)
D-2 Monoisopropyl glycol ether D-3: Water

As shown in Tables 1 to 4, the fiber treating agents of Examples 1 to 11 were blended with the titanium compound (A) and the compound (B) having an active hydrogen group, so that the component (I) and the above were treated. Since the component (II) is contained, it can be seen that the problem at the present application could be solved because of excellent heat resistance and high viscosity at high temperature.
On the other hand, although the fiber processing agent of Comparative Examples 1-4 contains the compound (B) having an active hydrogen group, it does not contain the titanium compound (A), so any of the problems of the present application are solved. Not done.

Industrial applicability

  A fiber reinforced composite material in which a matrix resin is reinforced with a reinforced fiber is used for automobile applications, aerospace applications, sports / leisure applications, general industrial applications, and the like. Examples of the reinforcing fiber include various inorganic fibers such as carbon fiber, glass fiber, and ceramic fiber, and various organic fibers such as aramid fiber, polyamide fiber, and polyethylene fiber.

Claims (9)

A sizing agent for reinforcing fibers comprising at least one selected from the following components (I) and (II):
Component (I): Compound obtained by reacting a titanium compound (A) and a compound (B) having an active hydrogen group Component (II): Titanium compound (A) and a compound (B) having an active hydrogen group   The sizing agent for reinforcing fibers according to claim 1, wherein the compound (B) includes a compound (B1) having a hydroxyl group.   The sizing agent for reinforcing fibers according to claim 2, wherein the compound (B1) contains at least one selected from an epoxy resin, a polyester resin, a urethane resin, and a polyether polyol resin. The sizing agent for reinforcing fibers according to any one of claims 1 to 3, wherein the component (II) satisfies the following condition 1.
Condition 1: The weight ratio (A / B) of the compound (A) to the compound (B) is 0.001 to 10% by weight. The sizing agent for reinforcing fibers according to any one of claims 1 to 4, wherein the compound (A) is represented by the following general formula (1).
(In the formula, R ^{1 to} R ⁴ are organic groups, which may be the same or different. N is an integer of 1 or more.)   The sizing agent for reinforcing fibers according to claim 5, wherein the organic group is an alkyl group having 2 to 8 carbon atoms, and the n is 1.   The sizing agent for reinforcing fibers according to any one of claims 1 to 6, further comprising a smoothing agent (C).   A reinforcing fiber strand formed by adhering the reinforcing fiber sizing agent according to any one of claims 1 to 7 to a raw material reinforcing fiber strand.   A fiber-reinforced composite material comprising a matrix resin and the reinforcing fiber strand according to claim 8.