JP2015160933A - aqueous resin composition and glass fiber sizing agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous resin composition which is excellent in properties of sizing glass fibers and usable in production of moldings excellent in mechanical strength and appearance and a glass fiber sizing agent.SOLUTION: An aqueous resin composition comprises (A) an acrylic resin obtained by copolymerizing a monocarboxylic acid (a1) having an unsaturated double bond and a dicarboxylic acid (anhydride) (a2) having an unsaturated double bond as essential raw materials and (B) an aqueous medium, and the acid number of (A) the acrylic resin is 700-900. A glass sizing agent containing the aqueous resin composition is excellent in properties of sizing glass fibers, and a glass fiber-reinforced plastic containing the composition or the glass sizing agent is excellent in appearance and mechanical strength.

Description

  The present invention relates to an aqueous resin composition useful for a glass fiber sizing agent and a glass fiber sizing agent.

  In general, glass fiber is formed by drawing molten glass from a number of nozzles provided at the bottom of a platinum bushing, and after the sizing agent is applied to the surface of each glass fiber (filament), several hundred to several Thousands are bundled into one strand. In addition, the glass fiber reinforced thermoplastic resin composition is made into a glass chopped strand by cutting the strand obtained as described above into a predetermined length, or winding the strand once and then drawing out and cutting it into a predetermined length. Thereafter, this is kneaded while being heated with a thermoplastic matrix resin, 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 give suitable adhesion to the thermoplastic resin. . Under such circumstances, as a glass fiber sizing agent for the purpose of improving the strength of a molded product, an acrylic resin copolymerized with a polymerizable monomer comprising (anhydrous) maleic acid and (meth) acrylic acid ester is an essential component. An acrylic resin composition has been proposed (see, for example, Patent Document 1).

  However, the molded product obtained by using the fiber sizing agent described in Patent Document 1 has insufficient strength in applications where higher mechanical strength is required, and when the fiber sizing agent is heated. The degree of coloring was large, and there was a problem with the appearance.

JP 2011-116589 A

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

  As a result of studying the above problems, the present inventors have found that an acrylic resin having a specific acid value obtained by copolymerizing a specific raw material and an aqueous resin composition containing an aqueous medium have the above problems. I found that it can be solved.

  That is, the present invention provides an acrylic resin (A) obtained by copolymerizing a monocarboxylic acid (a1) having an unsaturated double bond and a dicarboxylic acid (anhydride) (a2) having an unsaturated double bond as essential raw materials. ), And an aqueous resin composition containing an aqueous medium (B), wherein the acrylic resin (A) has an acid value in the range of 700 to 900.

  Since the acrylic resin composition of the present invention is excellent in glass fiber sizing properties, it can be used as a glass fiber sizing agent.

  In addition, the molded product obtained using the fiber bundle and the matrix resin bundled using the glass fiber sizing agent has a small degree of coloring, even when it is pulled, bent, or subjected to a strong impact. Since it has a mechanical strength at a level that does not pull cracks, it can be used in various applications including automobile and aircraft parts, home appliance parts and wind power generation members.

  The aqueous resin composition of the present invention is an acrylic resin obtained by copolymerizing a monocarboxylic acid (a1) having an unsaturated double bond and a dicarboxylic acid (anhydride) (a2) having an unsaturated double bond as essential raw materials. An aqueous resin composition containing a resin (A) and an aqueous medium (B), wherein the acrylic resin (A) has an acid value in the range of 700 to 900. In the present invention, the expression “dicarboxylic acid (anhydride)” represents one or both of “dicarboxylic acid” and “dicarboxylic anhydride”.

  First, the acrylic resin (A) will be described. The acrylic resin (A) is obtained by copolymerizing a monocarboxylic acid (a1) having an unsaturated double bond and a dicarboxylic acid (anhydride) (a2) having an unsaturated double bond as essential raw materials. is there.

  Examples of the monocarboxylic acid (a1) having an unsaturated double bond include (meth) acrylic acid, crotonic 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-octenoic acid, 7-octenoic acid, 2-nonenoic acid, 3-nonenoic acid, 8-nonenoic acid, 9-decenoic acid, 10- Examples include undecenoic acid, 3-allyloxypropionic acid, allyloxyvaleric acid, and ω-carboxy-polycaprolactone monoacrylate. Among these, (meth) acrylic acid is preferable because a molded product having more excellent tensile strength can be obtained. In addition, these monocarboxylic acid (a1) which has an unsaturated double bond can be used individually, or can also be used together 2 or more types.

  In the present invention, the notation “(meth) acryl” represents one or both of “acryl” and “methacryl”.

  Examples of the dicarboxylic acid (anhydride) (a2) having an unsaturated double bond include itaconic acid (anhydride), maleic acid (anhydride), and fumaric acid. Among these, itaconic acid (anhydride) and maleic acid (anhydride) are preferable because a molded article having more excellent tensile strength can be obtained. These dicarboxylic acids (anhydrides) (a2) having an unsaturated double bond can be used alone or in combination of two or more.

  As a raw material of the acrylic resin (A), in addition to the monocarboxylic acid (a1) and the dicarboxylic acid (anhydride) (a2), a monomer having another polymerizable unsaturated group as necessary ( a3) can be used.

  As said other monomer (a3) which has a polymerizable unsaturated group, (meth) acrylic-acid alkylester is mentioned, for example.

  Examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, cyclohexyl (meth) acrylate, and 2-ethylhexyl (meth). Examples include acrylate, lauryl (meth) acrylate, and stearyl (meth) acrylate. Among them, an alkyl having 1 to 8 carbon atoms (i.e., an alkyl group having an even better bundling property to the fiber and imparting more excellent strength to the finally obtained molded product ( A (meth) acrylate is preferable, and an alkyl (meth) acrylate having an alkyl group having 1 to 4 carbon atoms is more preferable.

  Examples of the other monomer (a3) having a polymerizable unsaturated group include vinyl monomers such as styrene, α-methylstyrene, paramethylstyrene, chloromethylstyrene, and vinyl acetate.

  Examples of the other monomer (a3) having a polymerizable unsaturated group include tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate, glycidyl (meth) acrylate, and diester. (Meth) acrylic acid diethylene glycol, di (meth) acrylic acid-1,4-butanediol, di (meth) acrylic acid-1,6-hexanediol, tri (meth) acrylic acid trimethylolpropane, di (meth) acrylic Acid glycerin etc. are mentioned.

  The other monomer (a3) having a polymerizable unsaturated group may be used alone or in combination of two or more.

  The amount of the monocarboxylic acid (a1) used is 10 to 90 in terms of a mass ratio in the monomer component that is a raw material of the acrylic resin (A) because the tensile strength and appearance of the obtained molded product are improved. The range of mass% is preferable, and the range of 20 to 80 mass% is more preferable. The amount of the dicarboxylic acid (anhydride) (a2) used is such that the tensile strength and appearance of the resulting molded product are improved, so the mass ratio in the monomer component that is the raw material of the acrylic resin (A). And the range of 10-70 mass% is preferable, and the range of 20-60 mass% is more preferable. In addition, the usage-amount of the other monomer (a3) used as needed is said monocarboxylic acid (a1) and dicarboxylic acid from the total 100 mass% of the monomer component which is a raw material of the said acrylic resin (A). It becomes the remainder except the use ratio of acid (anhydride) (a2).

  The acid value of the acrylic resin (A) is in the range of 700 to 900 because a molded product having excellent tensile strength and appearance is obtained, but the range of 700 to 800 is preferable. In addition, in this invention, an acid value is an acid value calculated | required by calculation from the monomer composition which is a raw material.

  The acrylic resin (A) preferably has a weight average molecular weight in the range of 3000 to 150,000.

  The acrylic resin (A) includes, for example, the monocarboxylic acid (a1) and the dicarboxylic acid (anhydride) (a2), and if necessary, the other monomer (a3), an organic solvent and / or water. In the presence of a polymerization initiator, it can be produced by heating at a temperature of 60 to 140 ° C. and radical polymerization.

  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, Cellosolves such as propylene glycol monomethyl ether acetate; ketones such as methyl ethyl ketone and methyl isobutyl ketone can be used. These solvents can 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), azobiscyanovaleric acid; tert-butylperoxy Organic peroxides such as pivalate, tert-butylperoxybenzoate, tert-butylperoxy-2-ethylhexanoate, di-tert-butyl peroxide, cumene hydroperoxide, benzoyl peroxide, tert-butyl hydroperoxide Oxides; inorganic peroxides such as hydrogen peroxide, ammonium persulfate, potassium persulfate, sodium persulfate and the like. These polymer initiators can be used alone or in combination of two or more. Moreover, it is preferable to use the said polymerization initiator within the range of 0.1-10 mass% with respect to the sum total of the monomer used as the raw material of the said acrylic resin (A).

  The aqueous resin composition of the present invention contains the acrylic resin (A) and the aqueous medium (B), but the acrylic resin (A) obtained by the above method is dissolved or dissolved in the aqueous medium (B). It is preferable that it is dispersed.

  Examples of the aqueous medium (B) include water, organic solvents miscible with water, and mixtures 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 glycols And lactams such as N-methyl-2-pyrrolidone. 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 only water.

  As a method of dissolving or dispersing the acrylic resin (A) in the aqueous medium (B), 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 (B), a method of neutralizing the acrylic resin (A), and a method of mixing the aqueous medium (B).

  When neutralizing the acrylic resin (A), it is preferable to use a basic compound. Examples of these basic compounds include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, 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 include quaternary ammonium hydroxide. Of these, organic amines and ammonia (ammonia water may be used) are preferably used. These basic compounds can be used alone or in combination of two or more.

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

  In addition, the glass fiber sizing agent of the present invention can contain components such as a binder such as urethane resin, acrylic resin, and epoxy resin, a lubricant, and an antistatic agent as long as the effects of the present invention are not impaired.

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

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples.

(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 95 parts by mass of n-butyl acetate and heated to 120 ° C., to which 99 parts by mass of maleic anhydride and 47 parts by mass of methyl acrylate were added. , 99 parts by mass of acrylic acid, 75 parts by mass of n-butyl acetate, 1.6 parts by mass of ditertiary butyl hydroperoxide and 3.0 parts by mass of tertiary butyl peroxybenzoate were added dropwise over 2 hours, 120 The reaction was performed at ˜125 ° C. After holding at 120 ° C. for 120 minutes, 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 for neutralization and water dissolution. After removing the solvent at 90 ° C. under reduced pressure (0.080 to 0.095 MPa), the solution was cooled to obtain an aqueous resin composition (1) having a nonvolatile content of 18% by mass, a pH of 7.5, and a viscosity of 580 mPa · s.

[Evaluation of appearance (coloring degree)]
The aqueous resin composition (1) obtained above 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. A film was obtained. Further, the appearance of the film after heat treatment at 200 ° C. for 1 hour was measured with a spectrocolorimeter (“CM-3500d” manufactured by Konica Minolta Co., Ltd.), and evaluated by ΔEab value. The lower the ΔEab value, the lower the coloring degree and the better.

(Example 2: Preparation and evaluation of aqueous resin composition (2))
A four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen blowing tube was charged with 150 parts by mass of ion-exchanged water, and the temperature was raised to 80 ° C .. A dissolved mixture dissolved in 180 parts by mass of ion-exchanged water heated to ° C and a dissolved product of 0.45 parts by mass of ammonium persulfate and 15 parts by weight of ion-exchanged water were dropped over 2 hours at 77 to 83 ° C. Reaction was performed. Thereafter, after holding at 80 ° C. for 120 minutes, the temperature is lowered to 50 ° C., 95% by mass of 25% aqueous ammonia is added, and an aqueous resin composition having a nonvolatile content of 16.4% by mass, pH 9.3, and a viscosity of 150 mPa · s 2) was obtained.

The appearance (coloring degree) was evaluated in the same manner as in Example 1 except that the aqueous resin composition (2) was used instead of the aqueous resin composition (1) of Example 1.

(Comparative Example 1: Preparation and evaluation of aqueous resin composition (R-1))
A 4-necked flask equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen blowing tube was charged with 95 parts by mass of n-butyl acetate and heated to 120 ° C., and then 74 parts by mass of maleic anhydride and 74 parts by mass of methyl acrylate. , 98 parts by mass of acrylic acid, 75 parts by mass of n-butyl acetate, 1.6 parts by mass of ditertiary butyl hydroperoxide and 3.0 parts by mass of tertiary butyl peroxybenzoate were added dropwise over 2 hours, and 120 The reaction was performed at ˜125 ° C. After holding at 120 ° C. for 120 minutes, 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 for neutralization and water dissolution. After removing the solvent at 90 ° C. under reduced pressure (0.080 to 0.095 MPa), the resultant was cooled to obtain an aqueous resin composition (R-1) having a nonvolatile content of 20% by mass, a pH of 7.3, and a viscosity of 580 mPa · s. It was.

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

(Comparative Example 2: Preparation and evaluation of aqueous resin composition (R-2))
A 4-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen blowing tube was charged with 95 parts by mass of n-butyl acetate and heated to 120 ° C., to which 98 parts by mass of maleic anhydride and n-butyl methacrylate 147 were added. A dissolved mixture of parts by mass, 75 parts by mass of n-butyl acetate, 1.6 parts by mass of ditertiary butyl hydroperoxide and 3.0 parts by mass of tertiary butyl peroxybenzoate was added dropwise over 2 hours, and the temperature reached 120 to 125 ° C. The reaction was performed. After holding at 120 ° C. for 120 minutes, 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 for neutralization and water dissolution. After removing the solvent at 90 ° C. under reduced pressure (0.080 to 0.095 MPa), the mixture was cooled to obtain an aqueous resin composition (R-2) having a nonvolatile content of 23% by mass, a pH of 7.6, and a viscosity of 580 mPa · s. It was.

The appearance (coloring degree) was evaluated in the same manner as in Example 1 except that the aqueous resin composition (R-2) was used instead of the aqueous resin composition (1) of Example 1.

  Table 1 shows the monomer compositions and evaluations of Examples 1-2 and Comparative Examples 1-2.

(Example 3: Preparation and evaluation of glass fiber sizing agent (1))
12.2 parts by mass of the aqueous resin composition (1) obtained above (3 parts by mass as solid content), 0.5 part by mass of γ-aminopropyltriethoxysilane, and 87.3 parts by mass of ion-exchanged water were mixed. And a glass fiber sizing agent (1) was prepared.

[Evaluation of convergence]
The glass fiber sizing agent (1) obtained above was uniformly applied to the surface of the 13 μm diameter fiber by 1% with respect to the fiber mass. After concentrating the fibers, the fibers were cut to a length of 3 mm and dried to prepare chopped strands (1). 50 g of this chopped strand (1) and 100 g of polyamide 66 resin were put into a 1 L volume tumbler and mixed for 10 minutes, and then the generated fluff was collected and its mass was measured and evaluated according to the following criteria.
○: Less than 0.15 g Δ: 0.15 g or more and less than 1.5 g ×: 1.5 g or more

[Evaluation of tensile strength]
A mixture composed of 30% by mass of the chopped strand (1) obtained above, 69.5% by mass of polyamide 66 (nylon 66) resin, and 0.5% by mass of magnesium oxide was kneaded while heating at 270 ° C. After pelletizing by the method, an FRTP molded product was prepared by injection molding the pellet. Subsequently, the tensile strength (ASTM D638) of the obtained FRTP molded product was evaluated according to the following criteria.
◎: 100 MPa or more ○: 90 MPa or more and less than 100 MPa Δ: 70 MPa or more and less than 90 MPa ×: 70 MPa or less

(Example 4: Preparation and evaluation of glass fiber sizing agent (2))
18.3 parts by mass of the aqueous resin composition (2) obtained in Example 2 (3 parts by mass as the solid content), 0.5 parts by mass of γ-aminopropyltriethoxysilane, and 81.2 parts by mass of ion-exchanged water Were mixed to prepare a glass fiber sizing agent (2). Moreover, it replaced with the glass fiber sizing agent (1) used in Example 3, and produced the chopped strand and the FRTP molded product similarly to Example 3 except having used the glass fiber sizing agent (2). And tensile strength were evaluated.

(Comparative Example 3: Preparation and evaluation of glass fiber sizing agent (R-1))
15 parts by mass (3 parts by mass as a solid content) of the aqueous resin composition (R-1) obtained in Comparative Example 1, 0.5 parts by mass of γ-aminopropyltriethoxysilane, and 84.5 parts by mass of ion-exchanged water Were mixed to prepare a glass fiber sizing agent (R-1). Moreover, it replaced with the glass fiber sizing agent (1) used in Example 3, and produced the chopped strand and the FRTP molded product similarly to Example 3 except having used the glass fiber sizing agent (R-1). The bundling property and the tensile strength were evaluated.

(Comparative Example 4: Preparation and evaluation of glass fiber sizing agent (R-2))
13 parts by mass (3 parts by mass as a solid content) of the aqueous resin composition (R-1) obtained in Comparative Example 1, 0.5 parts by mass of γ-aminopropyltriethoxysilane, and 86.5 parts by mass of ion-exchanged water Were mixed to prepare a glass fiber sizing agent (R-2). Moreover, it replaced with the glass fiber sizing agent (1) used in Example 3, and produced the chopped strand and the FRTP molded product similarly to Example 3 except having used the glass fiber sizing agent (R-2). The bundling property and the tensile strength were evaluated.

  Table 2 shows the compositions and evaluation results of Examples 3 to 4 and Comparative Examples 3 to 4 described above.

  Examples 1 and 2, which are aqueous resin compositions of the present invention, have a low degree of coloration upon heating, and the glass fiber sizing agent containing them has excellent glass fiber sizing properties, and also contains them. It was confirmed that the glass fiber reinforced plastic is excellent in mechanical strength (tensile strength).

  On the other hand, Comparative Example 1 is an example in which the acid value of the acrylic resin that is a component of the aqueous resin composition is outside the range of 700 to 900, but the sizing property of the obtained glass fiber sizing agent, and the obtained glass fiber. It was confirmed that the mechanical strength (tensile strength) of the reinforced plastic was insufficient.

  Comparative Example 2 is an example in which the component of the acrylic resin that is a component of the aqueous resin composition does not have a monocarboxylic acid having an unsaturated double bond, and the acid value is outside the range of 700 to 900. It was confirmed that the degree of coloring at the time of heating was large, and the sizing property of the obtained glass fiber sizing agent and the mechanical strength (tensile strength) of the obtained glass fiber reinforced plastic were insufficient.

Claims (3)

  Acrylic resin (A) obtained by copolymerizing monocarboxylic acid (a1) having an unsaturated double bond and dicarboxylic acid (anhydride) (a2) having an unsaturated double bond as essential raw materials, and an aqueous medium An aqueous resin composition comprising (B), wherein the acrylic resin (A) has an acid value in the range of 700 to 900.   The mass ratio of the monocarboxylic acid (a1) having the unsaturated double bond in the monomer component which is a raw material of the acrylic resin (A) is in the range of 10 to 90% by mass, and the unsaturated double bond 2. The aqueous resin composition according to claim 1, wherein a mass ratio of the dicarboxylic acid (anhydride) (a2) having a content of 10 to 70 mass%.   A glass fiber sizing agent comprising the aqueous resin composition according to claim 1.