JP2006241623A - Aqueous dispersion and inorganic fiber treated with the same and inorganic-fiber reinforced thermoplastic resin composition comprising the same inorganic fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous dispersion having excellent sizing properties of inorganic fibers and improving adhesiveness to the inorganic fibers and a matrix resin and thereby affording a molded product of an inorganic-fiber reinforced thermoplastic resin having excellent mechanical strength, to provide the inorganic fibers treated with the aqueous dispersion and to provide an inorganic-fiber reinforced thermoplastic resin composition comprising the inorganic fibers. <P>SOLUTION: The aqueous dispersion is characterized as comprising an acid-modified polyolefinic resin (A) which is an acid-modified polyolefinic resin modified with unsaturated dicarboxylic acids and has >20,000 weight-average molecular weight and ≥4 acid value and/or its salt. The inorganic fibers are treated with the aqueous dispersion and the inorganic-fiber reinforced thermoplastic resin composition comprises the inorganic fibers. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an aqueous dispersion of an unsaturated dicarboxylic acid-modified polyolefin resin useful as a sizing agent for inorganic fibers, an inorganic fiber treated with the aqueous dispersion, and an inorganic fiber-reinforced thermoplastic containing the inorganic fiber. The present invention relates to a resin composition.

  Conventionally, as a treatment agent (bundling agent) for reinforcing inorganic fibers blended in a resin composition, a silane coupling agent, a urethane emulsion, an epoxy emulsion, an acrylic emulsion, or the like has been used in order to enhance the resin reinforcing effect. .

  However, when the matrix resin is a polyolefin resin, the one treated with the above conventional sizing agent has insufficient adhesion strength between the matrix resin and the inorganic fibers, and the resulting inorganic fiber reinforced thermoplastic resin molded article is tensile. There was a problem that various physical properties such as strength, bending strength and impact strength were lowered.

Patent Document 1 proposes a sizing agent for inorganic fibers comprising an aqueous dispersion containing a polypropylene resin modified with an unsaturated dicarboxylic acid or a salt thereof as an essential component. Even when blended inorganic fibers were added, the effect of improving the strength of the resin was insufficient. Further, Patent Document 2 describes a sizing agent for inorganic fibers containing a carboxylic acid or a salt thereof bonded to a polymer chain. The strength improvement effect was insufficient.
JP-A-6-107442 JP-A-10-1331048

  The object of the present invention is to solve the above-mentioned conventional problems, and can improve the adhesion of inorganic fibers and improve the adhesion between the inorganic fibers and the matrix resin, whereby the inorganic fibers have excellent mechanical strength. An object is to provide an aqueous dispersion capable of obtaining a reinforced thermoplastic resin molded article, inorganic fibers treated with the aqueous dispersion, and an inorganic fiber-reinforced thermoplastic resin composition containing the inorganic fibers.

  The aqueous dispersion of the present invention is an acid-modified polyolefin resin modified with an unsaturated dicarboxylic acid, having a weight average molecular weight of more than 20000 and an acid value of 4 or more, and / or an acid-modified polyolefin resin (A) and / or It contains the salt.

  In the aqueous dispersion of the present invention, the polyolefin resin is preferably a polypropylene resin, and the aqueous dispersion is an anionic surfactant (B) 1 with respect to 100 parts by weight of the polyolefin resin (A) and / or its salt. It is preferable that it contains ~ 20 parts by weight, the water content is 3 to 90% by weight, and the resin solid content is present as finely dispersed particles.

  Such an aqueous dispersion of the present invention is suitable as a sizing agent for inorganic fibers.

  The inorganic fiber of the present invention is characterized by being treated using such an aqueous dispersion of the present invention.

  The inorganic fiber reinforced thermoplastic resin composition of the present invention is characterized by including the inorganic fiber of the present invention, and a polyolefin resin is suitable as the matrix resin.

  The aqueous dispersion of the present invention is excellent in the binding property of inorganic fibers and can effectively improve the adhesion between the inorganic fibers and the matrix resin. Therefore, by using the inorganic fibers treated with this aqueous dispersion, Further, mechanical properties such as tensile strength, bending strength and impact strength of the inorganic fiber reinforced thermoplastic resin molded article can be remarkably improved.

Hereinafter, embodiments of the present invention will be described in detail.
<Polyolefin resin (A)>
The polyolefin resin (A) contained in the aqueous dispersion of the present invention is a polyolefin resin modified with unsaturated dicarboxylic acids.

  The polyolefin resin is preferably a propylene resin, for example, a homopolymer of propylene, and a copolymer of propylene and one or more selected from ethylene, other α-olefins or vinyl compounds. Here, as the other α-olefin, an α-olefin having 4 to 18 carbon atoms, such as 1-butene, isobutene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene and 1-decene. , 1-dodecene and the like. These polyolefin resins may be used alone or in combination of two or more. Of these, preferred as polyolefin resins are propylene homopolymers.

  There are no particular restrictions on the unsaturated dicarboxylic acids used for modification of the polyolefin-based resin. For example, unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, and itaconic acid, as well as maleic anhydride and itaconic anhydride. Examples thereof include anhydrides of unsaturated dicarboxylic acids such as acid and citraconic anhydride, and ester derivatives of unsaturated dicarboxylic acids such as methyl maleate. These unsaturated dicarboxylic acids may be used individually by 1 type, and may use 2 or more types together. A preferred unsaturated dicarboxylic acid is maleic anhydride.

  When the weight average molecular weight of the acid-modified polyolefin resin (A) used in the present invention is 20000 or less, the impact strength of an inorganic fiber reinforced thermoplastic resin molded article blended with inorganic fibers treated using the aqueous dispersion of the present invention. The effect of improving the mechanical strength is insufficient. Accordingly, in the present invention, an acid-modified polyolefin resin (A) having a weight average molecular weight exceeding 20000 is used. The upper limit of the weight average molecular weight of the acid-modified polyolefin resin (A) is not particularly limited, but if it is excessively large, the dispersed particle size of the produced aqueous dispersion becomes enlarged, and the storage stability of the aqueous dispersion is lowered. Therefore, it is usually about 150,000. The weight average molecular weight of the acid-modified polyolefin resin (A) is preferably 25,000 to 120,000.

  In addition, when the acid value of the acid-modified polyolefin resin (A) used in the present invention is less than 4, the impact of the inorganic fiber reinforced thermoplastic resin molded product containing the inorganic fiber treated with the aqueous dispersion of the present invention. The effect of improving mechanical strength such as strength is insufficient. Accordingly, in the present invention, an acid-modified polyolefin resin (A) having an acid value of 4 or more is used. Although there is no restriction | limiting in particular about the upper limit of the acid value of this acid-modified polyolefin resin (A), since the dispersion rate of an aqueous dispersion will fall when too large, it is about 200 normally. The acid value of the acid-modified polyolefin resin (A) is preferably 10 to 160.

  The acid-modified polyolefin resin (A) can be produced by reacting an unsaturated dicarboxylic acid with a polyolefin resin according to a conventional method, and the modifying group may be in the form of a salt.

  This acid-modified polyolefin resin (A) may be present in the form of a salt when a basic substance is added, as described later, during the production of the aqueous dispersion of the present invention.

<Anionic surfactant (B)>
The aqueous dispersion of the present invention may contain an anionic surfactant (B). By containing the anionic surfactant (B), the aqueous dispersion of the present invention appears to be a solid fine particle. An aqueous dispersion of particles. Here, the anionic surfactant (B) is not particularly limited, and examples thereof include primary higher fatty acid salts, secondary higher fatty acid salts, primary higher alcohol sulfates, and secondary higher alcohols. Sulfate ester, primary higher alkyl sulfonate, secondary higher alkyl sulfonate, higher alkyl disulfonate, sulfonated higher fatty acid salt, higher fatty acid sulfate ester salt, higher fatty acid ester sulfonate salt, higher alcohol ether Sulfate sulfonates, higher alcohol ether sulfonates, higher fatty acid amide alkylol sulfates, alkylbenzene sulfonates, alkylphenol sulfonates, alkylnaphthalene sulfonates, alkylbezoimidazole sulfonates, etc. Can be mentioned.

  Among these anionic surfactants, particularly preferred are higher fatty acids, particularly saturated or unsaturated higher fatty acid salts having 10 to 20 carbon atoms, particularly alkali metal salts. Specifically, Capric acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, arachidic acid, etc. Or an alkali metal salt of a mixture thereof.

  One type of these anionic surfactants (B) may be used alone, or two or more types may be used in combination.

  The anionic surfactant (B) is contained in an amount of 1 to 20 parts by weight, particularly 5 to 15 parts by weight, based on 100 parts by weight of the acid-modified polyolefin resin (A) and / or a salt thereof according to the present invention. It is preferable that If the amount of the anionic surfactant (B) is less than 1 part by weight, the emulsification characteristics are reduced and the amount of non-emulsified product is increased. If the amount exceeds 20 parts by weight, the reinforcing effect on the thermoplastic resin is reduced. Is also not preferred.

<Other ingredients>
The aqueous dispersion of the present invention may contain a thermoplastic resin other than the acid-modified polyolefin resin (A). In particular, in order to reduce the particle size of the aqueous dispersion, one or more of low molecular weight acid-modified polyolefin (co) polymers may be contained. Here, as the low molecular weight acid-modified polyolefin (co) polymer, the same ethylene- and propylene homopolymers as those of the polyolefin-based resin of the acid-modified polyolefin resin (A), and propylene and ethylene, other α-olefins or And a copolymer with one or more selected from vinyl compounds. Examples of the α-olefin include α-olefins having 4 to 18 carbon atoms such as 1-butene, isobutene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene and 1-dodecene. Etc. Of these, preferred are propylene homopolymers.

<Properties of aqueous dispersion>
The aqueous dispersion of the present invention preferably has a moisture content of 3 to 90% by weight and a solid content concentration of 10 to 97% by weight, particularly 25 to 65% by weight. When the water content is high and the solid content concentration is low, the thermoplastic resin is insufficiently reinforced. Conversely, when the water content is low and the solid content concentration is high, the storage stability of the aqueous dispersion is low. descend.

  In addition, the aqueous dispersion of the present invention is usually solid or pasty in a moisture content range of 3 to 35% by weight.

  The aqueous dispersion of the present invention also has a resin solid content derived from the polyolefin resin (A) and / or a salt thereof as a finely dispersed particle phase. The average particle diameter of the finely dispersed particles of the resin solid content is preferably 0.01 to 1 μm, and particularly preferably 0.05 to 0.5 μm. In order to make the average particle size of the finely dispersed particles excessively small, the resin physical properties of the inorganic fiber reinforced thermoplastic resin composition are lowered by increasing the necessary addition amount of the anionic surfactant, and if it is too large, the aqueous dispersion The storage stability of the resin deteriorates and is not preferable for practical use.

<Method for producing aqueous dispersion>
The aqueous dispersion of the present invention is prepared by, for example, melt-kneading the acid-modified polyolefin resin (A), an anionic surfactant (B), and, if necessary, a low molecular weight acid-modified polyolefin copolymer and other additives. Then, it can be produced by adding water and a basic substance to the obtained melt-kneaded product and causing phase inversion so that the resin solid content becomes finely dispersed particles. The basic substance is required to saponify an unneutralized anionic surfactant when phase inversion of resin solids as finely dispersed particles is used.

  Here, basic substances used include substances that act as bases in water such as alkali metals, alkaline earth metals, ammonia, and amines, alkali metal oxides, hydroxides, weak bases, hydrides, Examples thereof include substances that act as bases in water, such as alkaline earth metal oxides, hydroxides, weak bases, and hydrides, and alkoxides of these metals.

  The basic substance may be added directly, but is preferably added in the form of an aqueous solution of about 5 to 40% by weight. The addition amount of the basic substance is usually about 0.4 to 8 parts by weight with respect to the polyolefin resin (A) and / or a salt thereof.

  The melt kneading step and the phase inversion step may be performed sequentially or simultaneously.

  The melt kneading means used in the melt kneading step may be any known means, but preferably a kneader, a Banbury mixer, a multi-screw extruder, etc. can be exemplified. The aqueous dispersion produced by sequentially dropping water and melt-kneading is then cooled naturally or artificially to room temperature. At this time, the dispersed particles are solidified to form a stable aqueous dispersion.

  By producing an aqueous dispersion in this way, an aqueous dispersion in which the resin solid content derived from the acid-modified polyolefin resin (A) and / or its salt is present as a finely dispersed particle phase is obtained.

  In the production of the aqueous dispersion of the present invention, various auxiliary materials that can be usually used in the aqueous dispersion, such as emulsifiers, stabilizers, wetting agents, thickeners, foaming agents, antifoaming agents, coagulations, etc. An agent, a gelling agent, an anti-aging agent, a plasticizer, a filler, a coloring agent, a flavoring agent, an anti-tacking agent, a release agent, and the like can be used in combination as necessary.

[Inorganic fiber]
The inorganic fiber of the present invention is obtained by treatment with the aqueous dispersion of the present invention as described above.

  Examples of inorganic fibers to which the aqueous dispersion of the present invention is applied include glass fibers, carbon fibers, alumina fibers, ceramic fibers, rock fibers, slug fibers, and the like, and carbon fibers and glass fibers are particularly preferable. These fibers may be used alone or in combination of two or more.

  Specific examples of the glass fiber include glass roving, glass chop strand, glass middle fiber, glass powder, glass stable, glass cloth, and the like.

  As carbon fibers, various known carbon fibers such as carbon fibers made from polyacrylonitrile, rayon, pitch, hydrocarbon gas, graphite fibers, and metal-coated carbons coated with metals such as nickel, aluminum, copper, etc. Examples thereof include fibers. Particularly preferred are polyacrylonitrile-based carbon fibers and metal-coated carbon fibers obtained therefrom.

  Carbon fibers having a fiber length of 0.1 to 50 mm and a fiber diameter of 5 to 30 μm, particularly 10 to 20 μm are preferred from the viewpoint of the reinforcing effect.

  In the present invention, the method for treating the inorganic fiber with the aqueous dispersion is not particularly limited, and any method such as a dipping method, a spray method, or a transfer method may be used, but the dipping method is preferable, and the impregnation property is improved. It is preferable to use a plurality of rollers during immersion. For example, an inorganic fiber strand composed of thousands to hundreds of thousands of filaments is dipped in the aqueous dispersion of the present invention, dried, and then cut into a length of 0.1 to 50 mm. An inorganic fiber chopped strand bundled with an aqueous dispersion can be obtained. In this case, the amount of the aqueous dispersion of the present invention to be attached to the inorganic fiber is not particularly limited, but usually 0.1 to 5% by weight, preferably about 0.2 to 3% by weight as a solid content with respect to the inorganic fiber. It is preferable to set it as the range.

  In this treatment, the concentration may be adjusted by adding water to the aqueous dispersion of the present invention. The solid concentration suitable for the treatment is usually about 30 to 650 g / L.

[Inorganic fiber reinforced thermoplastic resin composition]
The inorganic fiber reinforced thermoplastic resin composition of the present invention contains the inorganic fiber of the present invention as described above.

  The resin used as the matrix resin of the thermoplastic resin composition of the present invention is not particularly limited. For example, ABS, AAS, AES, ethylene vinyl acetate copolymer, modified ethylene vinyl acetate copolymer, chlorinated ethylene Vinyl acetate copolymer, ethylene vinyl alcohol copolymer, polyethylene, ultra high molecular weight polyethylene, polypropylene, fluorine plastic, polyacetal, polyamide, polyethylene terephthalate, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, polycarbonate, polystyrene, polyvinyl alcohol , Polyvinyl butyral, polyphenylene ether, polymethyl methacrylate and the like. These thermoplastic resins may be used individually by 1 type, and may use 2 or more types together. Of these, polyolefin resins such as polyethylene, polypropylene, ethylene vinyl acetate copolymer, and ethylene vinyl alcohol copolymer are preferable, and polypropylene resin is particularly preferable.

  The content of the inorganic fiber treated with the aqueous dispersion of the present invention relative to the thermoplastic resin in the composition is 5 to 70 parts by weight, preferably 10 to 50 parts by weight with respect to 100 parts by weight of the thermoplastic resin. If the content of the inorganic fiber is less than 5 parts by weight, the mechanical strength of the resulting composition is not sufficiently improved, and if it exceeds 70 parts by weight, the moldability is lowered and molding becomes difficult, resulting in a molded product obtained. The mechanical strength also decreases. In addition, in the thermoplastic resin composition of this invention, 2 or more types of inorganic fiber may be contained, and the inorganic fiber processed with the different aqueous dispersion may be contained.

  The thermoplastic resin composition of the present invention further includes other fillers and reinforcing materials, thermal stabilizers, antioxidants, light stabilizers, flame retardants, plasticizers, in addition to the above components, for the purpose of strengthening or modifying the components. An antistatic agent, a release agent, a foaming agent, a nucleating agent, and the like may be contained.

  The inorganic fiber reinforced thermoplastic resin composition of the present invention can be produced by melt-kneading a matrix resin together with inorganic fibers treated with the aqueous dispersion of the present invention and other optional components. Here, a known technique can be applied to the kneading method. For example, the compounding ingredients are supplied to a kneader such as a single screw extruder, twin screw extruder, Banbury mixer, kneading roll, Brabender, kneader, etc., or a kneading machine such as a Henschel mixer, and 170 to 300 ° C., preferably 180 to 280. It can be performed by heating and melting at 0 ° C.

  EXAMPLES Hereinafter, although a manufacture example, an Example, and a comparative example are given and this invention is demonstrated further more concretely, unless this summary is exceeded, this invention is not limited to a following example. In the following, “part” means “part by weight”, and “%” means “% by weight”.

Production Example 1: Production of Aqueous Dispersion (X-1) Polypropylene resin modified with maleic anhydride having a weight average molecular weight of 30000 and an acid value of 52 (a homopolymer of propylene) ("Yumex" manufactured by Sanyo Chemical Industries, Ltd.) 1010 ") 100 parts and 10 parts of potassium oleate. Next, this mixture was fed at a rate of 4 kg / hour from a hopper of a twin-screw extruder (“PCM-30 type” L / D = 40 manufactured by Ikekai Steel Co., Ltd.), and a potassium hydroxide 20% aqueous solution was fed at 110 g / hour. While continuously supplying, the melt was kneaded at a heating temperature of 200 ° C. to extrude the melt. Subsequently, the melt was continuously supplied to a cooling single screw extruder attached to the tip of the extruder and cooled to 90 ° C. The taken-out solid was poured into warm water at 80 ° C. and continuously dispersed to obtain an aqueous dispersion (X-1) having an average particle diameter of dispersed particles of 0.22 μm and a solid content concentration of 45%.

Production Example 2: Production of Aqueous Dispersion (X-2) As acid-modified polyolefin resin, polypropylene resin modified with maleic anhydride having a weight average molecular weight of 40,000 and an acid value of 26 (propylene homopolymer) (Sanyo Kasei) An aqueous dispersion (X-2) was prepared in the same manner as in Production Example 1 except that 100 parts of “YUMEX 1003” manufactured by Kogyo Co., Ltd. was used. This aqueous dispersion (X-2) had an average particle diameter of dispersed particles of 0.25 μm and a solid content concentration of 45%.

Production Example 3 Production of Aqueous Dispersion (X-3) As an acid-modified polyolefin resin, a polypropylene resin modified with maleic anhydride having a weight average molecular weight of 10,000 and an acid value of 3.5 (propylene homopolymer) ( An aqueous dispersion (X-3) was prepared in the same manner as in Production Example 1 except that 100 parts of “Yumex 100TS” manufactured by Sanyo Chemical Industries, Ltd. was used. This aqueous dispersion (X-3) had an average particle diameter of dispersed particles of 0.15 μm and a solid content concentration of 45%.

Production Example 4: Production of carbon fiber chopped strand (Y-1) The aqueous dispersion (X-1) of the present invention obtained in Production Example 1 was adjusted to a concentration of 200 g / l by diluting with water. A carbon fiber strand (manufactured by Toho Rayon Co., Ltd., diameter 7 μm × 12000 filaments) is immersed in the body and dried to obtain 2.5% of the aqueous dispersion (X-1) as a solid content in the carbon fiber strand. Attached. Next, the carbon fiber strand was cut into a fiber length of 6 mm to prepare a carbon fiber chopped strand (Y-1).

Production Example 5: Production of carbon fiber chopped strand (Y-2) Carbon fiber chopped strand (Y-2) was produced in the same manner as in Production Example 4 except that the aqueous dispersion (X-2) was used as the aqueous dispersion. Was made.

Production Example 6: Production of carbon fiber chopped strand (Y-3) Carbon fiber chopped strand (Y-3) was carried out in the same manner as in Production Example 4 except that the aqueous dispersion (X-3) was used as the aqueous dispersion. Was made.

Production Example 7: Production of carbon fiber chopped strand (Y-4) The same as Production Example 4 except that a bisphenol type epoxy resin ("Epicoat 828" manufactured by Yuka Shell Epoxy Co., Ltd.) was used as the carbon fiber treatment agent. A carbon fiber chopped strand (Y-4) was produced.

Production Example 8: Production of carbon fiber chopped strand (Y-5) A carbon fiber chopped strand (Y-5) was produced in the same manner as in Production Example 4 except that a urethane resin emulsion was used as the carbon fiber treatment agent.

Examples 1 and 2 and Comparative Examples 1 to 3
Polypropylene resin (“J205” manufactured by Tonen Chemical Co., Ltd.) was kneaded at 230 ° C. and 250 rpm using a 44 mmφ twin screw extruder, and obtained in Production Examples 4 to 8 using a gravimetric feeder in the middle of the extruder. Each carbon fiber chopped strand was supplied to obtain a carbon fiber reinforced polypropylene resin composition. In any case, the mixing ratio was 25 parts of carbon fiber chopped strands with respect to 75 parts of polypropylene resin.

The bending elastic modulus, tensile breaking strength, and Izod impact strength of the obtained carbon fiber reinforced polypropylene resin composition were measured by the following methods, and the results are shown in Table 1.
Flexural modulus: measured according to ASTM D-790 Tensile strength at break: measured according to ASTM D-638 Izod impact strength: measured according to ASTM D-256

  From Table 1, it can be seen that according to the present invention, an inorganic fiber reinforced thermoplastic resin molded article having excellent bending elastic modulus, tensile breaking strength and impact strength can be obtained.

Claims (8)

  An acid-modified polyolefin resin modified with an unsaturated dicarboxylic acid, characterized by comprising an acid-modified polyolefin resin (A) having a weight average molecular weight exceeding 20000 and an acid value of 4 or more and / or a salt thereof. Aqueous dispersion.   The aqueous dispersion according to claim 1, wherein the polyolefin-based resin is a polypropylene resin.   The aqueous dispersion according to claim 1 or 2, comprising 1 to 20 parts by weight of an anionic surfactant (B) with respect to 100 parts by weight of the polyolefin resin (A) and / or a salt thereof.   The aqueous dispersion according to any one of claims 1 to 3, wherein the water content is 3 to 90% by weight and the resin solid content is present as finely dispersed particles.   The aqueous dispersion according to any one of claims 1 to 4, wherein the aqueous dispersion is a sizing agent for inorganic fibers.   An inorganic fiber treated with the aqueous dispersion according to any one of claims 1 to 5.   An inorganic fiber reinforced thermoplastic resin composition comprising the inorganic fiber according to claim 6.   The inorganic fiber-reinforced thermoplastic resin composition according to claim 7, wherein the thermoplastic resin is a polyolefin resin.