JP6699153B2 - Aqueous resin composition and fiber sizing agent - Google Patents

Description

  The present invention relates to an aqueous resin composition and a fiber sizing agent which are useful for fiber sizing and the like.

  Generally, glass fibers are formed by drawing molten glass from a large number of nozzles provided at the bottom of a platinum bushing, and the surface of each glass fiber (filament) is coated with a sizing agent, then several hundreds to several Thousands are bundled into one strand. Further, the glass fiber reinforced thermoplastic resin composition, the strand obtained as described above is cut into a predetermined length, or the strand is once wound and then pulled out, to obtain a glass chopped strand by cutting into a predetermined length After that, this is kneaded with a thermoplastic matrix resin while heating, and then molded into a predetermined shape by various molding methods.

Conventionally, for the purpose of improving the mechanical properties of glass fiber reinforced thermoplastic resin (FRTP), various glass fiber sizing agents have been proposed which are coated on the surface of glass fiber and impart suitable adhesion to the thermoplastic resin. . Among these, as a glass fiber sizing agent for the purpose of improving the strength of the molded product, an acrylic resin obtained by copolymerizing a polymerizable monomer consisting of (anhydrous) maleic acid and (meth)acrylic acid ester is an essential component. The acrylic resin composition has been proposed (for example, refer to Patent Document 1).

  However, the molding material obtained using the fiber sizing agent described in Patent Document 1 is inferior in heat discoloration resistance during high temperature processing, and there is a problem in the appearance of the molded product.

JP, 2011-116589, A

  The problem to be solved by the present invention is to provide an aqueous resin composition and a fiber sizing agent which are excellent in fiber sizing property and can be used for producing a molded article having excellent mechanical strength and appearance.

  As a result of studies conducted by the present inventors to solve the above problems, it was found that an acrylic resin having a specific composition and a weight average molecular weight of 5,000 to 150,000, and an aqueous resin composition containing an aqueous medium can solve the above problems. It was

  That is, the present invention relates to an acrylic resin (A) having a weight average molecular weight of 5,000 to 150,000 and containing (meth)acrylic acid alkyl ester (a1), (anhydrous) maleic acid (a2), and styrene (a3) as essential raw materials. And a mass ratio of the (meth)acrylic acid alkyl ester (a1) in the monomer component that is a raw material of the acrylic resin (A), which is 20 to 80. A water-based resin in which the mass ratio of the (anhydrous) maleic acid (a2) is in the range of 2 to 30 mass% and the mass ratio of the styrene (a3) is in the range of 10 to 40 mass%. It relates to a composition.

  INDUSTRIAL APPLICABILITY The aqueous resin composition of the present invention can be used as a fiber sizing agent because it has excellent fiber sizing properties and a molded product with excellent mechanical strength and appearance is obtained.

  Further, a molded article obtained by using a fiber bundle and a matrix resin bundled by using this fiber sizing agent has a small degree of coloring, and when it is stretched or bent, even when it is subjected to a strong impact, Since it has a mechanical strength of a level that does not cause cracks and the like, it can be used in various applications including, for example, members of automobiles and aircraft, parts of home electric appliances, and wind power generation members.

  The aqueous resin composition of the present invention comprises an acrylic resin (meth)acrylic acid alkyl ester (a1), (anhydrous) maleic acid (a2) and styrene (a3) as an essential raw material and having a weight average molecular weight of 5,000 to 150,000 ( A), and an aqueous resin composition containing an aqueous medium (B), wherein the mass ratio of the (meth)acrylic acid alkyl ester (a1) in the monomer component that is the raw material of the acrylic resin (A). Is in the range of 20 to 80% by mass, the mass ratio of the (anhydrous) maleic acid (a2) is in the range of 2 to 30% by mass, and the mass ratio of the styrene (a3) is in the range of 10 to 40% by mass. Is what is.

  In the present invention, the expression "(meth)acrylic acid alkyl ester" represents either or both of "acrylic acid alkyl ester" and "methacrylic acid alkyl ester", and "(anhydrous) maleic acid" The notation of "" represents either or both of "maleic acid" and "maleic anhydride".

  First, the acrylic resin (A) will be described. The acrylic resin (A) contains (meth)acrylic acid alkyl ester (a1), (anhydrous) maleic acid (a2), and styrene (a3) as essential raw materials.

  Examples of the (meth)acrylic acid alkyl ester (a1) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, Examples thereof include lauryl (meth)acrylate and stearyl (meth)acrylate. Among these, an alkyl (meth)acrylate having an alkyl group having 4 to 14 carbon atoms is preferable because the focusing property is further improved. In addition, these (meth)acrylic acid alkyl ester (a1) can be used individually or in combination of 2 or more types.

  In addition to the (meth)acrylic acid alkyl ester (a1), the (anhydrous) maleic acid (a2), and the styrene (a3), other raw materials of the acrylic resin (A) may be used, if necessary. The monomer (a4) can be used.

  Examples of the other monomer (a4) include (meth)acrylamide, glycidyl (meth)acrylate, 2-methylaminoethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and 2-hydroxypropyl (meth). ) Acrylic, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, γ-methacryloxypropyltrimethoxysilane, vinyl triethoxysilane, etc. Body, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, diethylene glycol di(meth)acrylate, di(meth)acrylic acid-1,4-butanediol, di(meth)acrylic acid-1, 6-hexanediol, trimethylolpropane tri(meth)acrylate, glycerin di(meth)acrylate, α-methylstyrene, paramethylstyrene, chloromethylstyrene, (meth)acrylic acid, fumaric acid, (anhydrous) citraconic acid , Mesaconic acid, (anhydrous) itaconic acid, (anhydrous) aconitic acid and the like. In addition, these other monomers (a4) can be used alone or in combination of two or more kinds.

  The amount of the (meth)acrylic acid alkyl ester (a1) used is a unit amount of the raw material of the acrylic resin (A) from the viewpoint of the balance of physical properties such as hue, fiber sizing property, and mechanical strength of a good molded product. The mass ratio in the body component is in the range of 20 to 80% by mass, more preferably 30 to 60% by mass.

  The amount of the (anhydrous) maleic acid (a2) used is excellent in fiber-converging property, and from the viewpoint of a good balance of physical properties such as hue, fiber-converging property and mechanical strength of the molded product, the raw material of the acrylic resin (A). The mass ratio in the monomer component is 2 to 30% by mass, and more preferably 3 to 25% by mass.

  The amount of the styrene (a3) used is a unit amount which is a raw material of the acrylic resin (A), from the viewpoint of excellent fiber-converging property, balance of physical properties such as hue, fiber-converging property and mechanical strength of a good molded product. The mass ratio in the body component is in the range of 10 to 40% by mass, but the range of 15 to 30% by mass is more preferable.

  The amount of the other monomer (a4) used as necessary may be 100% by mass of the total of the monomer components as the raw material of the acrylic resin (A) to the (meth)acrylic acid alkyl ester ( It is the balance excluding the usage ratios of a1), (anhydrous) maleic acid (a2) and styrene (a3).

  The weight average molecular weight of the acrylic resin (A) is in the range of 5,000 to 150,000, and more preferably in the range of 10,000 to 50,000, since a molded product having excellent mechanical strength can be obtained. Here, the weight average molecular weight is a polystyrene-converted value based on gel permeation chromatography (hereinafter abbreviated as “GPC”) measurement.

  Further, the acid value of the acrylic resin (A) is preferably in the range of 20 to 600, more preferably in the range of 35 to 500, from the viewpoint of the hue of a good molded product and the balance of physical properties of fiber sizing and mechanical strength. .. In the present invention, the acid value is the acid value calculated from the monomer composition of the raw material.

  The acrylic resin (A) includes, for example, the (meth)acrylic acid alkyl ester (a1), the (anhydrous) maleic acid (a2), the styrene (a3), and optionally other monomers (a4). ) Can be produced by radical polymerization in an organic solvent and/or water in the presence of a polymerization initiator at a temperature of 60 to 140°C.

  Examples of the organic solvent include aromatic solvents such as toluene and xylene; alicyclic solvents such as cyclohexanone; ester solvents such as butyl acetate and ethyl acetate; isobutanol, normal butanol, isopropyl alcohol, sorbitol, propylene. A cellosolve solvent such as glycol monomethyl ether acetate; a ketone solvent such as methyl ethyl ketone or methyl isobutyl ketone can be used. These solvents may be used alone or in combination of two or more.

  Examples of the polymerization initiator include azo compounds such as 2,2′-azobis(isobutyronitrile), 2,2′-azobis(2-methylbutyronitrile) and azobiscyanovaleric acid; tert-butylperoxy. Pivalate, tert-butyl peroxybenzoate, tert-butyl peroxy-2-ethylhexanoate, di-tert-butyl peroxide, di-tert-butyl hydroperoxide, cumene hydroperoxide, benzoyl peroxide, tert. -Organic peroxides such as butyl hydroperoxide; inorganic peroxides such as hydrogen peroxide, ammonium persulfate, potassium persulfate and sodium persulfate. These polymer initiators can be used alone or in combination of two or more kinds. Further, the polymerization initiator is preferably used within a range of 0.1 to 10% by mass based on the total amount of the monomers as the raw material of the acrylic resin (A).

  The aqueous resin composition of the present invention contains an acrylic resin (A) and an aqueous medium (B). The acrylic resin (A) obtained by the above method is dissolved in the aqueous medium (B) or It is preferably dispersed.

  Examples of the aqueous medium (B) include water, an organic solvent miscible with water, and a mixture thereof. Examples of the organic solvent miscible with water include alcohols such as methanol, ethanol, n-propanol and isopropanol; ketones such as acetone and methyl ethyl ketone; polyalkylene glycols such as ethylene glycol, diethylene glycol and propylene glycol; alkyl ethers of polyalkylene glycol. Lactams such as N-methyl-2-pyrrolidone and the like. In the present invention, only water may be used, a mixture of water and an organic solvent miscible with water may be used, or only an organic solvent miscible with water may be used. From the viewpoint of safety and load on the environment, water alone or a mixture of water and an organic solvent miscible with water is preferable, and it is particularly preferable to use water alone.

  The method of dissolving or dispersing the acrylic resin (A) in the aqueous medium (B) includes a method of polymerizing the acrylic resin (A) in the aqueous medium (B), the acrylic resin (A) and the aqueous medium. Examples thereof include a method of mixing with (B) and a method of mixing the neutralized acrylic resin (A) with the aqueous medium (B).

  When neutralizing the acrylic resin (A), it is preferable to use a basic compound, and examples of these basic compounds include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, and 2-amino. Organic amines such as ethanol and 2-dimethylaminoethanol; inorganic basic compounds such as ammonia, sodium hydroxide and potassium hydroxide; tetramethylammonium hydroxide, tetra-n-butylammonium hydroxide and trimethylbenzylammonium hydroxide. Examples thereof include primary ammonium hydroxide. Among these, it is preferable to use an organic amine and ammonia (ammonia water may be used). These basic compounds may be used alone or in combination of two or more.

  Further, the aqueous resin composition of the present invention, if necessary, a curing catalyst, a lubricant, a filler, a thixotropic agent, a tackifier, a wax, a heat stabilizer, a light fastness stabilizer, an optical brightener, a foaming agent. Such as additives, pH adjusters, leveling agents, gelation inhibitors, dispersion stabilizers, antioxidants, radical scavengers, heat resistance imparting agents, inorganic fillers, organic fillers, plasticizers, reinforcing agents, catalysts, Antibacterial agent, antifungal agent, rust preventive agent, thermoplastic resin, thermosetting resin, pigment, dye, conductivity imparting agent, antistatic agent, moisture permeability improving agent, water repellent, oil repellent, hollow foam, crystal Water-containing compounds, flame retardants, water absorbents, moisture absorbents, deodorants, foam stabilizers, defoamers, mildew-proofing agents, preservatives, anti-algae agents, pigment dispersants, anti-blocking agents, hydrolysis inhibitors, etc. Can be used together.

  The water-based resin composition of the present invention has excellent resin impregnation properties, and thus can be suitably used for binder applications such as fiber sizing agents.

  The fiber sizing agent of the present invention contains the aqueous resin composition, but it is preferable to contain a silane coupling agent because the mechanical strength of the obtained molded article is improved, and among them, γ It is particularly preferable to contain -aminopropyltriethoxysilane, γ-ureidopropyltriethoxysilane and γ-aminopropyltriethoxysilane. In addition, these silane coupling agents can be used alone or in combination of two or more kinds.

The silane coupling agent is 1 to 100 parts by mass of the solid content of the aqueous resin composition.
It is preferably used in the range of 30 parts by mass.

  Examples of the fiber material that can be treated with the fiber sizing agent of the present invention include, for example, glass fiber, carbon fiber, silicon carbide fiber, pulp, hemp, cotton, nylon, polyester, acrylic, polyurethane, polyimide, Kevlar, Nomex, etc. Examples include polyamide fibers made of aramid and the like. Among these, glass fiber and carbon fiber are preferable because a molded product having higher strength can be obtained.

The glass fibers and carbon fibers are bundled using the fiber sizing agent of the present invention, and as a method of forming a film on the surface of the glass fiber bundles or the carbon fiber bundles, for example, a fiber sizing agent is a kiss coater method, a roller. The method of uniformly applying the fiber sizing agent to the surface of the fiber by any other known method such as a coating method, a dipping method, a spray method, and a brush. When the fiber sizing agent contains an aqueous medium or an organic solvent as a solvent, it is preferable that the fiber sizing agent be dried by heating using a heating roller, hot air, a hot plate, or the like after the application.

The amount of the coating film formed on the surface of the fiber material is preferably in the range of 0.1 to 15% by mass, and preferably 1 to 10% by mass, based on the total mass of the bundled and surface-treated fiber bundle. A range is more preferable.

  The fiber treated with the fiber sizing agent of the present invention is used as a reinforcing material for a matrix resin such as a polyolefin resin, a polycarbonate resin, a polyamide resin and a polyester resin, and is particularly preferably used for a polyamide resin.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The weight average molecular weight of the acrylic resin is measured under the following GPC measurement conditions.

[GPC measurement conditions]
Measuring device: High-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation were connected in series and used.
"TSKgel G5000" (7.8 mm ID x 30 cm) x 1 "TSK gel G4000" (7.8 mm ID x 30 cm) x 1 "TSK gel G3000" (7.8 mm ID x 30 cm) x 1 This "TSKgel G2000" (7.8 mm ID x 30 cm) x 1 Detector: RI (differential refractometer)
Column temperature: 40°C
Eluent: Tetrahydrofuran (THF)
Flow rate: 1.0 mL/min Injection volume: 100 μL (tetrahydrofuran solution with sample concentration 4 mg/mL)
Standard sample: A calibration curve was prepared using the following monodisperse polystyrene.

(Monodisperse polystyrene)
Tosoh Corporation "TSK gel standard polystyrene A-500"
Tosoh Corporation "TSK gel standard polystyrene A-1000"
Tosoh Corporation "TSK gel standard polystyrene A-2500"
Tosoh Corporation "TSKgel Standard Polystyrene A-5000"
"TSK gel standard polystyrene F-1" manufactured by Tosoh Corporation
"TSK gel standard polystyrene F-2" manufactured by Tosoh Corporation
"TSK gel standard polystyrene F-4" manufactured by Tosoh Corporation
Tosoh Corporation "TSK gel standard polystyrene F-10"
Tosoh Corporation "TSK gel standard polystyrene F-20"
Tosoh Corporation "TSK gel standard polystyrene F-40"
"TSK gel standard polystyrene F-80" manufactured by Tosoh Corporation
Tosoh Corporation “TSKgel Standard Polystyrene F-128”
Tosoh Corporation "TSK gel standard polystyrene F-288"
Tosoh Corporation "TSK gel standard polystyrene F-550"

(Example 1: Preparation and evaluation of aqueous resin composition (1))
A 4-necked flask equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen blowing tube was charged with 55 parts by mass of methyl isobutyl ketone (hereinafter abbreviated as “MIBK”) and heated to 115° C. 4 parts by mass of acid, 28 parts by mass of styrene, 68 parts by mass of n-butyl acrylate, 25 parts by mass of MIBK, 1 part by mass of t-butylperoxy 2-ethylhexanoate were added dropwise over 3 hours to carry out the reaction. It was Next, the temperature was lowered to 50° C., and 6 parts by mass of 25% ammonia water and 500 parts by mass of ion-exchanged water were added over about 15 minutes to solubilize water. MIBK was removed of the solvent while maintaining the temperature at 50° C. and depressurizing the inside of the flask with an aspirator. After removing the solvent, the mixture was cooled and ion-exchanged water was added to obtain an aqueous resin composition (1) having a nonvolatile content of 25% by mass. The weight average molecular weight of this aqueous resin composition (1) was 20,000.

[Evaluation of appearance (coloring degree)]
12 parts by mass of the aqueous resin composition (1) obtained above (3 parts by mass as resin solid content), 0.5 part by mass of γ-aminopropyltriethoxysilane, 0.09 part by mass of calcium hypophosphite, and ion exchange. A fiber sizing agent (1) was prepared by mixing 87.41 parts by mass of water. This fiber sizing agent (1) was poured onto a base material having a frame at the four corners of the A4 size PP base material, dried at room temperature for 24 hours, and further dried at 150° C. for 5 minutes to obtain a film having a thickness of 150 μm. Furthermore, this film was heat-treated at 200° C. for 1 hour. The appearance of the sample before and after the heat treatment was measured with a spectrocolorimeter (“CM-3500d” manufactured by Konica Minolta Co., Ltd.), and the ΔE value was evaluated according to the following criteria. The lower the ΔE value, the smaller the degree of coloring, which is preferable.
◯: less than 5 Δ: 5 or more and less than 10 x: 10 or more

(Example 2: Preparation and evaluation of aqueous resin composition (2))
Into a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen blowing tube, 55 parts by mass of MIBK was charged and heated to 115° C., and 12 parts by mass of maleic anhydride, 24 parts by mass of styrene, and n-butyl acrylate were added. A dissolved mixture of 64 parts by mass, MIBK 25 parts by mass, and t-butylperoxy 2-ethylhexanoate 1 part by mass was added dropwise over 3 hours to carry out a reaction. Next, the temperature was lowered to 50° C., and 17 parts by mass of 25% ammonia water and 500 parts by mass of ion-exchanged water were added over about 15 minutes to effect water solubilization. MIBK was removed of the solvent while maintaining the temperature at 50° C. and depressurizing the inside of the flask with an aspirator. After removing the solvent, the mixture was cooled and ion-exchanged water was added to obtain an aqueous resin composition (2) having a nonvolatile content of 25% by mass. The weight average molecular weight of this aqueous resin composition (1) was 24,000.

(Example 3: Preparation and evaluation of aqueous resin composition (3))
Into a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen blowing tube, 45 parts by mass of MIBK was charged and the temperature was raised to 115° C., 20 parts by mass of maleic anhydride, 60 parts by mass of n-butyl acrylate, MIBK35. A dissolved mixture of 1 part by mass of t-butylperoxy 2-ethylhexanoate and 1 part by mass of t-butylperoxy was added dropwise over 3 hours to carry out a reaction. Then, the temperature was lowered to 50° C., and 28 parts by mass of 25% ammonia water and 500 parts by mass of ion-exchanged water were added over about 15 minutes to effect water solubilization. MIBK was removed of the solvent while maintaining the temperature at 50° C. and depressurizing the inside of the flask with an aspirator. After removing the solvent, the mixture was cooled and ion-exchanged water was added to obtain an aqueous resin composition (3) having a nonvolatile content of 25% by mass. The weight average molecular weight of this aqueous resin composition (3) was 18,000.

The appearance (coloring degree) was evaluated in the same manner as in Example 1 except that the aqueous resin composition (3) was used in place of the aqueous resin composition (1) of Example 1.

(Comparative Example 1: Preparation and evaluation of aqueous resin composition (R1))
95 parts by mass of butyl acetate was charged into a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen blowing tube, and heated to 120° C., and 98 parts by mass of maleic anhydride and 147 parts by mass of n-butyl methacrylate were added thereto. , 75 parts by mass of butyl acetate, 1.6 parts by mass of di-t-butyl hydroperoxide, and 3 parts by mass of t-butylperoxybenzoate were added dropwise over 3 hours to carry out the reaction. Then, the temperature was lowered to 90° C., and 137 parts by mass of 25% ammonia water and 600 parts by mass of ion-exchanged water were added over about 15 minutes to solubilize water. While maintaining the temperature at 90° C. and depressurizing the inside of the flask with an aspirator, butyl acetate was removed as a solvent. After removing the solvent, the mixture was cooled and ion-exchanged water was added to obtain an aqueous resin composition (R1) having a nonvolatile content of 23% by mass. The weight average molecular weight of this aqueous resin composition (R1) was 21,000.

The appearance (coloring degree) was evaluated in the same manner as in Example 1 except that the aqueous resin composition (R1) was used instead of the aqueous resin composition (1) of Example 1.

(Comparative Example 2: Preparation and evaluation of aqueous resin composition (R2))
Into a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen blowing tube, 45 parts by mass of MIBK was charged and heated to 115° C., and 20 parts by mass of maleic anhydride, 50 parts by mass of styrene, and n-butyl acrylate were added. A dissolved mixture of 30 parts by mass, MIBK 35 parts by mass, and t-butylperoxy 2-ethylhexanoate 1 part by mass was added dropwise over 3 hours to carry out a reaction. Next, the temperature was lowered to 50° C., and 25 parts by mass of 25% ammonia water and 500 parts by mass of ion-exchanged water were added over about 15 minutes to effect water solubilization. MIBK was removed of the solvent while maintaining the temperature at 50° C. and depressurizing the inside of the flask with an aspirator. After removing the solvent, the mixture was cooled and ion-exchanged water was added to obtain an aqueous resin composition (R2) having a nonvolatile content of 25% by mass. The weight average molecular weight of this aqueous resin composition (R2) was 25,000.

The appearance (coloring degree) was evaluated in the same manner as in Example 1 except that the aqueous resin composition (R2) was used instead of the aqueous resin composition (1) of Example 1.

  Table 1 shows the monomer compositions and evaluation results of Examples 1 to 2 and Comparative Examples 1 to 3 described above.

  It was confirmed that those of Examples 1 to 3 containing the aqueous resin composition of the present invention had a small degree of coloring upon heating and were excellent in appearance.

  On the other hand, Comparative Example 1 is an example in which the content of maleic anhydride in the monomer component that is the raw material of the acrylic resin exceeds the upper limit of 30 mass% and does not contain styrene, but the degree of coloring during heating is It was confirmed to be large.

  Comparative Example 2 is an example in which the content of styrene in the monomer component as the raw material of the acrylic resin exceeds the upper limit of 50% by mass, but it was confirmed that the degree of coloring during heating was large.

Claims (2)

Acrylic resin (A) having a weight average molecular weight of 5,000 to 150,000, which contains (meth)acrylic acid alkyl ester (a1), (anhydrous) maleic acid (a2), and styrene (a3) as essential raw materials, and an aqueous medium (B) A water-based resin composition containing, wherein the mass ratio of the (meth)acrylic acid alkyl ester (a1) in the monomer component as the raw material of the acrylic resin (A) is in the range of 20 to 80 mass %. There, the mass ratio of the maleic acid (anhydride) (a2) is in the range of 2 to 30 mass%, the mass ratio of the styrene (a3) contains a water-based resin composition in the range of 10 to 40 wt% A fiber sizing agent characterized by the above . The fiber sizing agent according to claim 1, wherein the (meth)acrylic acid alkyl ester (a1) has an alkyl group having 4 to 14 carbon atoms.