JP2000335942A - Glass fiber binder for reinforcing polyacetal resin and glass fiber bundle using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both a glass fiber binder excellent in bundling properties and capable of providing a glass fiber bundle producing high reinforcing effects on a polyacetal resin and the glass fiber bundle for reinforcing the polyacetal resin using the binder. SOLUTION: This glass fiber binder for reinforcing a polyacetal resin comprises (A) a film-forming component, (B) a coupling agent, (C) a lubricant and (D) phosphorous acid as a pH adjustor and has a pH regulated within the range of 3-6.5. The glass fiber bundle for reinforcing the polyacetal resin is obtained by applying the binder to plural glass fiber filaments and bundling the glass fiber filaments.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a glass fiber sizing agent for reinforcing a polyacetal resin and a glass fiber bundle for reinforcing a polyacetal resin using the sizing agent. More specifically, the present invention relates to a sizing agent which is excellent in sizing property and provides a glass fiber bundle which provides a high reinforcing effect to a polyacetal resin, and a polyacetal resin obtained by sizing a plurality of glass fiber filaments using the sizing agent. The present invention relates to a reinforcing glass fiber bundle.

[0002]

2. Description of the Related Art Conventionally, a glass fiber reinforced composite material in which glass fiber is blended with a thermoplastic resin or a thermosetting resin has been widely used as a material for various structures because it gives a molded article having excellent mechanical properties. . By the way, polyacetal resin (polyoxymethylene resin) is an engineering resin having excellent mechanical properties, electrical properties, chemical properties, and the like, and is used in many fields, for example, fields of electronics, automobiles, OA equipment, machinery, home electric appliances, and the like. In recent years, attempts have been made to use it as a material for composite materials in fields requiring high strength and high elastic modulus. Because this polyacetal resin is chemically inert, even if a reinforcing material such as glass fiber or glass powder is blended, polyamide, polycarbonate,
Compared to other resins such as polyethylene terephthalate,
It has a disadvantage that the reinforcing effect is hardly exhibited.

In order to improve such disadvantages, various methods for modifying polyacetal resin have been proposed (JP-B-46-25259), JP-B-55-18874, and JP-A-55-18874. Kaisho 46-6
388, JP-A-55-157645, and JP-A-58-98356). However, such a method for modifying a polyacetal resin has a disadvantage that the cost is inevitably high.

[0004] Therefore, for polyacetal resin,
As a sizing agent for providing a glass fiber bundle that provides a reinforcing effect at a low cost, a composition containing a tetrafunctional epoxy resin emulsion, a silane coupling agent, a cationic lubricant, and acetic acid has been proposed (Japanese Patent Application Laid-Open No. Sho 60/1985). -22134
No. 3). In this sizing agent, acetic acid is used to solubilize the cationic lubricant into a uniform sizing agent to give a glass fiber bundle having excellent sizing and reinforcing effects. However, when a glass fiber bundle bundled using this sizing agent is blended with a polyacetal resin, a small amount of acetic acid remaining on the surface of the glass fiber bundle may cause the polyacetal resin to decompose, and a sufficient reinforcing effect may not be obtained. Some problems arise.

On the other hand, a glass fiber sizing agent containing a reducing bleach such as phosphorous acid or phosphite has been proposed (JP-A-55-149147). In this sizing agent, phosphorous acid or phosphite is used to prevent coloring of a glass fiber bundle bundled using the sizing agent, and is not used for adjusting pH. Instead, it is fundamentally different from the technical idea of the present invention.

[0006]

SUMMARY OF THE INVENTION Under such circumstances, the present invention provides a glass fiber sizing agent which has excellent sizing properties and provides a glass fiber bundle which provides a high reinforcing effect to a polyacetal resin. It is an object of the present invention to provide a glass fiber bundle for reinforcing a polyacetal resin using an agent.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, have further adjusted the pH of a glass fiber sizing agent containing a film forming component, a coupling agent and a lubricant. With phosphorous acid as an agent, pH
It has been found that a sizing agent obtained by adjusting the content of the sizing agent to a specific range is suitable for the purpose, and based on this finding, the present invention has been completed.

That is, the present invention relates to a glass fiber sizing agent containing at least (A) a film-forming component, (B) a coupling agent and (C) a lubricant, and (D) phosphorous acid as a pH adjuster. It is intended to provide a glass fiber sizing agent for reinforcing a polyacetal resin, wherein the glass fiber sizing agent is blended and the pH is adjusted within a range of 3 to 6.5.

The present invention also relates to a glass fiber bundle obtained by adhering a glass fiber sizing agent to a plurality of glass fiber filaments and bundling the glass fiber sizing agent, wherein the glass fiber sizing agent is used as the glass fiber sizing agent. Another object is to provide a glass fiber bundle for reinforcing a polyacetal resin.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The film-forming component of component (A) in the glass fiber sizing agent for reinforcing a polyacetal resin of the present invention (hereinafter sometimes simply referred to as "the sizing agent of the present invention") is particularly limited. There is no conventional one known as a film forming component of a glass fiber sizing agent, such as polyurethane resin, acrylic resin, epoxy resin, natural rubber or synthetic rubber. Among them, those containing at least a polyurethane resin as a resin component are preferable from the viewpoint of convergence and the like. This film-forming component is usually used in the form of an aqueous emulsion.

As the above-mentioned polyurethane-based resin, those obtained from a polyisocyanate component mainly composed of xylylene diisocyanate and a polyol component mainly composed of polyester polyol are preferable from the viewpoint of sizing property and the like. Here, as xylylene diisocyanate, o
-Xylylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate and mixtures thereof. Of these, m-xylylene diisocyanate is preferred.

On the other hand, polyester polyols include:
For example, a condensation-based polyester polyol obtained by dehydration condensation of a polyhydric alcohol and a polycarboxylic acid, a lactone-based polyester polyol obtained by ring-opening polymerization of a lactone based on a polyhydric alcohol, and a polyether polyol with a lactone at the end. Examples thereof include ester-modified ester-modified polyols and copolymerized polyester polyols thereof.

Examples of the polyhydric alcohol used in the above-mentioned condensed polyester polyol include ethylene glycol, propylene glycol, 1,3-propanediol, butylene glycol, 1,4-butanediol, 1,5-pentanediol, Xylene glycol, glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, and the like.Examples of polycarboxylic acids include succinic acid, adipine Acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3-
Examples thereof include cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, and trimellitic acid.

The lactone polyester polyol includes, for example, poly (ε-caprolactone) polyol. These polyester polyols preferably have a weight average molecular weight in the range of 500 to 4000.

The polyurethane resin can be produced, for example, by heating xylylene diisocyanate and polyester polyol at about 30 to 130 ° C. in the absence of a solvent or in the presence of a small amount of an organic solvent.
When performing the heating reaction, the polyhydric alcohol exemplified in the description of the polyester polyol may be appropriately coexisted as a chain extender. When an organic solvent is used, the organic solvent is not particularly limited as long as it does not react with isocyanate and is miscible with water.Examples include acetone, methyl ethyl ketone, tetrahydrofuran, and dimethyl. Formamide and the like can be used.

As a method for producing an aqueous polyurethane resin emulsion, there are the following self-emulsification method and a method using an emulsifier, which may be appropriately combined. (1) Hydrophilicity by introducing an ionic group (sulfonic acid group, amino group, carboxyl group, etc.) or a nonionic hydrophilic group (polyethylene glycol, polyoxyalkylene glycol, etc.) into the side chain or terminal of the polyurethane resin. A method of dispersing or dissolving in water by self-emulsification after imparting properties.

(2) When producing a polyurethane resin,
As a monomer, in addition to the polyester polyol component and the xylylene diisocyanate component, a water-soluble polyol such as polyethylene glycol or monoalkoxy polyethylene glycol is coexistent, and dispersed or dissolved in water as a polyurethane resin having relatively high affinity for water. Self-emulsifying method.

(3) A blocking agent (alcohol, oxime, etc.) for the isocyanate group present in the polyurethane resin
Method for forcibly dispersing the polymer blocked by the method using an emulsifier and mechanical shearing force.

(4) A method of forcibly dispersing a polyurethane resin in water by using an emulsifier and mechanical shearing force without using a blocking agent.

When or after emulsification, a chain extender is added to the polyurethane resin having an isocyanate group, whereby a polyurethane resin emulsion having a higher molecular weight can be produced. As the chain extender at that time, for example, known agents such as ethylene glycol, diethylene glycol, propylene glycol, hydrazine, and N, N-dimethylhydrazine can be used.

The coupling agent (B) in the sizing agent of the present invention is used to improve the wettability and adhesion of the glass fiber with the polyacetal resin. There are a series, a titanate, an aluminum, a chromium, a zirconium, and a borane coupling agent. Among them, a silane coupling agent is particularly preferable.

Examples of the silane coupling agent include triethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3 , 4-Epoxycyclohexyl) ethyltrimethoxysilane, N-β- (aminoethyl)-
γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-
Mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, N-β- (vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride and the like. One type of the coupling agent (B) may be used, or two or more types may be used in combination.

The lubricant of the component (C) in the sizing agent of the present invention is used to prevent the glass fiber filaments from being damaged by mutual abrasion or from being broken and fluffed. A cationic lubricant is preferable, and examples thereof include a cationically active alkyl imidazoline derivative, triethylenetetramine pelargonic acid, and tetraethylenepentamine distearate. The lubricant of the component (C) may be used alone or in combination of two or more.

In the sizing agent of the present invention, phosphorous acid is used as the component (D) in order to adjust the pH. The sizing agent containing the above-mentioned components (A), (B) and (C) usually tends to be alkaline unless the pH is adjusted, and in the case of alkaline, the lubricant of the component (C), particularly a cationic lubricant Precipitates or does not work effectively, and the performance as a sizing agent is reduced. Therefore, conventionally, formic acid or acetic acid has been used for pH adjustment.However, when a glass fiber bundle bundled with a sizing agent containing formic acid or acetic acid is used for reinforcing a polyacetal resin, it is present on the glass fiber surface. There was a problem that the polyacetal resin was decomposed by a trace amount of formic acid or acetic acid, and the reinforcing effect was not sufficiently exhibited. In the present invention, phosphorous acid used as a pH adjuster does not decompose the polyacetal resin and has an antioxidant effect, so that it is possible to prevent coloring of the glass fiber bundle bundled with the sizing agent. In the present invention, the pH of the sizing agent is adjusted to a range of 3 to 6.5, preferably 4 to 5.5 by adding the phosphorous acid of the component (D). When the pH is out of the above range, the performance as a sizing agent is not sufficiently exhibited.

The content of each component in the sizing agent of the present invention is not particularly limited.
The component (A) of the film-forming component is preferably 1 to 20% by weight, more preferably 4 to 10% by weight, and the coupling agent of the component (B) is preferably 0.1 to 5% by weight, more preferably 0 to 5% by weight. 0.3 to 1.0% by weight, and the lubricant of the component (C) is preferably 0.0001 to 5% by weight, and more preferably 0.1 to 5% by weight.
It is selected in the range of 01 to 0.5% by weight. (D)
The component phosphorous acid is compounded so that the pH of the sizing agent is in the range of 3 to 6.5, and the compounding amount is usually 0.01 to 1.0% by weight based on the total amount of the sizing agent. Preferably 0.1
０．４0.4% by weight.

The sizing agent of the present invention may contain, if necessary, various additives conventionally used in sizing agents, for example, antistatic agents, antioxidants, plasticizers, as long as the object of the present invention is not impaired. , A softener, and a shape-retaining agent such as an amine-modified epoxy resin or an acid-modified polyolefin resin. The ratio of the components (A) to (D) contained in the sizing agent is usually about 1 to 10% by weight.

Next, the glass fiber bundle for reinforcing the polyacetal resin of the present invention (hereinafter, may be simply referred to as the "glass fiber bundle of the present invention") has the above-mentioned sizing agent attached to a plurality of glass fiber filaments. And focused.
The glass fiber filament has a fiber diameter of 3 to 30.
μm is preferable, and the number of glass fiber filaments to be bundled is preferably 100 to 1
0000, more preferably in the range of 300 to 5000. The type of glass of the glass fiber filament is not particularly limited, and those commonly used for reinforcing a thermoplastic resin or a thermosetting resin can be used, and E glass is preferable.

In the glass fiber bundle of the present invention, the amount of the sizing agent attached to the plurality of glass fiber filaments is preferably in the range of 0.1 to 1.0% by weight in terms of solid content. When the amount is less than 0.1% by weight, the sizing property is insufficient, and when a glass fiber bundle is kneaded with a polyacetal resin to produce a molded product, yarn cracks and fuzzing are likely to occur,
If it exceeds 1.0% by weight, gas is generated during molding,
This may cause blistering of the molded product and decrease of its mechanical properties. In consideration of the sizing property, the appearance and mechanical properties of the polyacetal resin molded product, the more preferable amount of the sizing agent is in the range of 0.2 to 0.8% by weight in terms of solid content, and particularly 0.2 to 0.8% by weight. A range of 0.5% by weight is preferred.

The method for producing the glass fiber bundle of the present invention is not particularly limited, and a conventionally known method can be used. For example, the molten glass is drawn out from a number of nozzles attached to the bottom of the bushing, and the glass fiber filament is wound up while applying the sizing agent through an applicator, and the wound up is 80 to 1
The glass fiber bundle of the present invention is obtained by performing the heating and drying treatment at a temperature of about 50 ° C.

The use form of the glass fiber bundle of the present invention obtained by bundling a plurality of glass fiber filaments in this way is not particularly limited, and the glass chopped strand is selected according to the use of the glass fiber reinforced polyacetal resin. , Glass roving, glass chopped strand mat, glass roving cloth and the like.

The glass fiber bundle of the present invention is used for reinforcing a polyacetal resin. As the polyacetal resin to which the glass fiber bundle is applied, for example, polyoxymethylene of a homopolymer, formaldehyde-ethylene oxide copolymer obtained from trioxane and ethylene oxide, further modified polyacetal resin such as polyurethane-containing polyacetal, elastomer-containing polyacetal and the like. Is mentioned. Using a polyacetal resin and the glass fiber bundle of the present invention, as a method for producing a glass fiber reinforced polyacetal resin, as a method for producing a glass fiber reinforced thermoplastic resin, a glass fiber used from among various conventionally known methods. It can be appropriately selected according to the form of the bundle.

For example, when a glass chopped strand is used as the glass fiber bundle, the glass chopped strand is preferably 10 to 40% by weight, more preferably 2 to 40% by weight based on the total weight with the polyacetal resin.
0 to 30% by weight, usually 180 to 220
By melt-kneading at a temperature of preferably from 190 to 210 ° C, a glass fiber reinforced polyacetal resin can be produced.

The melt-kneading can be performed, for example, using a single-screw or twin-screw extruder. At this time, if desired, various known additives such as antioxidants, heat stabilizers,
An ultraviolet absorber, a light stabilizer, a lubricant, a flame retardant, a release agent, an inorganic or organic filler, an antistatic agent, a colorant, and the like may be appropriately blended and melt-kneaded. The thus melt-kneaded raw material is extruded, cooled, and the glass fiber reinforced polyacetal resin pellet obtained by cutting is molded by a known method such as injection molding or extrusion molding, whereby a molded article having a desired shape is obtained. can get.

[0034]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In addition, the amount of fluff of the chopped strand in each example, the amount of gas generated from the compound pellets, and the physical properties of the test pieces were measured according to the following methods. (1) Agitated fluff amount of chopped strand 200 g of chopped strand and polyacetal resin pellet (manufactured by Polyplastics, trade name: Duracon M)
90-31) Put 100 g into a beaker, bring to room temperature, and
After stirring for minutes (stirring conditions: 4-blade screw, 1300 rpm), this was sieved through a 3.5-mesh sieve, and the weight of the fluff remaining on the sieve was measured. The smaller this value is,
Shows good convergence.

<Physical Properties of Test Specimens> (2) Tensile Strength Tensile strength I before the boiling test and tensile strength II after the boiling test at 100 ° C. for 4 hours were measured in accordance with ASTM D638. . (3) Tensile elongation Tensile elongation was measured according to ASTM D638. (4) Flexural strength and flexural modulus The flexural strength and flexural modulus were measured according to ASTM D790. (5) Izod impact value (with notch) Izod impact value was measured according to ASTM D256.

(6) Hue # 80 TYPE III, ZI, manufactured by Nippon Denshoku Industries Co., Ltd.
L value, a value and b value were measured using I OPTICAL SENSOR. Lightness L value: 0 Dark ← → Bright 100 Chromaticity a value: −Green ← → Red + Chromaticity b value: −Blue ← → Yellow + The closer the a and b values are to 0, the whiter. However, considering only yellowing, the smaller the absolute value of the b value, the better.

Example 1 Poly (ε-caprolactone) having a weight average molecular weight of 2000
1. 150 parts by weight of polyol, trimethylolpropane
3 parts by weight and 30 parts by weight of m-xylylene diisocyanate were mixed and reacted at 80 ° C. for 2 hours. A small amount of dimethylformamide was added to 100 parts by weight of the reaction mixture, and a polyoxyethylene.
By adding 75 parts by weight of an aqueous solution containing 6 parts by weight of polyoxypropylene glycol (polyoxyethylene segment content: about 80% by weight, weight average molecular weight of polyoxypropylene segment: 3250), and stirring vigorously,
An emulsified dispersion was obtained. Then, 20 parts by weight of a 1% by weight hydrazine aqueous solution was added with stirring to extend the chain, and further diluted with water to obtain a polyurethane emulsion having a solid concentration of 30% by weight.

Next, in terms of active ingredients, 2.4% by weight of a polyurethane emulsion, 0.4% by weight of γ-aminopropyltriethoxysilane, 0.03% by weight of tetraethylenepentamine distearate, 0.15% by weight of phosphorous acid A glass fiber sizing agent having a pH of 5.0 and containing 0.07% by weight and 0.07% by weight of an amine-modified epoxy resin as a shape retaining agent was prepared.

The sizing agent obtained in this manner was
0.4% by weight in terms of solid content was adhered to the surface of a 1 μm (measured in accordance with JIS R3420) E glass fiber filament, and 1600 strands were bundled into a strand. The strand was cut into a length of 3 mm. 8 at 120 ° C
The glass chopped strand was produced by performing the drying process for a period of time. Table 1 shows the measurement results of the stirring fuzz amount of this glass chopped strand.

Next, a polyacetal resin (manufactured by Polyplastics Co., Ltd., trade name: DURACON M90) was prepared so that the chopped strand had a glass fiber content of 25% by weight.
-31), melt-kneaded with a twin-screw extruder, extruded, and cut to obtain compound pellets. Table 1 shows the measurement results of the amount of gas generated from the compound pellet. Using the in-line screw injection molding machine, a test piece specified in ASTM D638 and D790 was prepared from the compound pellet thus obtained, and its physical properties were measured. Table 1 shows the results.

Example 2 The same operations as in Example 1 were carried out except that isophorone diisocyanate was used in the same molar amount in place of m-xylylene diisocyanate. Table 1 shows the results.

Example 3 A tetrafunctional epoxy resin (manufactured by Mitsubishi Gas Chemical Company, trade name: T
35 parts by weight of ETRAD-X), 3 parts by weight of acetone, and 2 parts by weight of an emulsifier (trade name: Emulgen 915, manufactured by Kao Corporation) were mixed, and 60 parts by weight of water was slightly added while vigorously stirring the mixture with a homomixer. At a solids concentration of 35
A weight percent of a tetrafunctional epoxy resin emulsion was obtained. Next, a glass fiber sizing agent was prepared in the same manner as in Example 1 except that the above-mentioned tetrafunctional epoxy resin emulsion was used instead of the polyurethane emulsion in Example 1, and then the same operation as in Example 1 was performed. Was performed, and each characteristic was obtained. Table 1 shows the results.

Comparative Example 1 1.2% by weight of the polyurethane emulsion obtained in Example 1, 1.3% by weight of γ-aminopropyltriethoxysilane, 0.03% by weight of tetraethylenepentamine distearate in terms of active ingredients Containing 0.7% by weight of acetic acid and 0.07% by weight of an amine-modified epoxy resin
A glass fiber sizing agent of 5.0 was prepared. Using this sizing agent, the same operation as in Example 1 was performed to determine each characteristic. Table 1 shows the results.

Comparative Example 2 A glass fiber sizing agent having a pH of 10 containing 3.0% by weight of the polyurethane emulsion obtained in Example 1 and 1.0% by weight of γ-aminopropyltriethoxysilane was prepared as active ingredients. Using this sizing agent, the same operation as in Example 1 was performed to determine each characteristic. Table 1 shows the results.

[0045]

[Table 1]

[0046]

The glass fiber sizing agent of the present invention is excellent in sizing property and can give a glass fiber bundle which gives a high reinforcing effect to polyacetal resin. The glass fiber reinforced polyacetal resin using the glass fiber bundle of the present invention has excellent mechanical properties, and is suitably used particularly in fields requiring high strength and high elastic modulus.

Claims (7)

[Claims] 1. A glass fiber sizing agent comprising at least (A) a film-forming component, (B) a coupling agent and (C) a lubricant, further comprising (D) phosphorous acid as a pH adjuster, The glass fiber sizing agent for reinforcing a polyacetal resin, wherein is adjusted to a range of 3 to 6.5. 2. The glass fiber sizing agent according to claim 1, wherein the film-forming component (A) contains at least a polyurethane resin as a resin component. 3. The glass fiber sizing agent according to claim 2, wherein the polyurethane resin is obtained by using a polyisocyanate component mainly composed of xylylene diisocyanate and a polyol component mainly composed of polyester polyol. 4. The glass fiber sizing agent according to claim 1, wherein the coupling agent as the component (B) is a silane coupling agent. 5. The glass fiber sizing agent according to claim 1, wherein the lubricant of the component (C) is a cationic lubricant. 6. A glass fiber bundle obtained by adhering a glass fiber sizing agent to a plurality of glass fiber filaments and bunching the glass fiber sizing agent, wherein the glass fiber sizing agent is used as the glass fiber sizing agent.
A glass fiber bundle for reinforcing a polyacetal resin, wherein the glass fiber sizing agent according to any one of the above items is used. 7. The amount of the glass fiber sizing agent to be attached to a plurality of glass fiber filaments is from 0.1 to 0.1 in terms of solid content.
The glass fiber bundle according to claim 6, which is 1.0% by weight.