JP7606346B2 - Antistatic agent for glass fibers and sizing agent for glass fibers containing the same - Google Patents

Description

The present invention relates to an antistatic agent for glass fibers and a sizing agent for glass fibers.

Glass fibers are widely used as reinforcing fibers in the manufacture of fiber-reinforced plastics (FRP) and fiber-reinforced cement products. A bundling agent is applied to glass filaments (single glass fibers) pulled out of a bushing (a spinning nozzle for molten glass) to bundle a predetermined number of filaments, which are then wound up into glass strands (glass fiber bundles). These are then heated and dried, and processed into glass fiber products such as rovings (glass strands wound into a cylindrical shape), chopped strands (glass strands cut to a predetermined length), and chopped strand mats (chopped strands stacked and formed into a mat).

In the glass fiber manufacturing process, static electricity is easily generated, which can be an obstacle to the work. For example, static electricity generated in the glass strand cutting process can cause the cut material to stick to the cutter and the cutting performance to deteriorate in a short period of time. For this reason, in order to prevent the generation of static electricity, methods have been used in the past to add an antistatic agent to the bundling agent or to apply an antistatic agent between the production and cutting of the glass strand. Quaternary ammonium sulfates such as lauryl dimethyl ethyl ammonium ethyl sulfate and octyl dimethyl ethyl ammonium ethyl sulfate are used as antistatic agents for such glass fibers (see Patent Documents 1 to 4).

Special Publication No. 62-42870 Special Publication No. 5-30780 JP 2015-113256 A JP 2017-206787 A

However, these conventional quaternary ammonium salts do not have sufficient antistatic effect, and a large amount of antistatic agent must be used to obtain the desired antistatic effect. In addition, conventional quaternary ammonium salts have the disadvantage of causing coloring of glass fibers at high temperatures, and coloring of glass fibers at high temperatures such as during the drying process in the glass fiber manufacturing process is a problem. In view of the above problems, there has been a demand for the development of an antistatic agent that exhibits sufficient antistatic performance and does not cause coloring of glass fibers.
The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an antistatic agent for glass fibers that can reduce static electricity generated during processing of glass fibers and can produce resin molded articles with good appearance.

The inventors came up with the idea of using a highly concentrated liquid quaternary ammonium salt to facilitate migration of the salt to the surface of the glass strands together with moisture as they dry, thereby improving the antistatic properties, and thus completed the present invention.

（式中、Ｒ^１は、炭素数８以上２２以下のアルキル基又はアルケニル基を示し、Ｒ^２は、炭素数１以上３以下のアルキル基を示し、ｍ及びｎは、エチレンオキシ基の平均付加モル数を示し、それぞれ独立に０．５以上１０以下の数である。Ｒ^３は、炭素数１以上３以下のアルキル基を示す。）
［２］常温で液状である、［１］に記載のガラス繊維用帯電防止剤。
［３］［１］又は［２］に記載のガラス繊維用帯電防止剤を含有するガラス繊維用集束剤。
［４］さらに被膜形成剤、潤滑剤及びシランカップリング剤を含有する、［３］に記載のガラス繊維用集束剤。
［５］複数本のガラス繊維モノフィラメントと、該ガラス繊維モノフィラメントに［３］又は［４］に記載のガラス繊維用集束剤を塗布して形成された皮膜とを有するガラス繊維。
［６］［５］に記載のガラス繊維と、熱硬化性樹脂とを含有することを特徴とする樹脂成型体。 That is, the present invention is as follows.
[1] An antistatic agent for glass fibers, comprising a quaternary ammonium salt represented by the following general formula (1):

(In the formula, ^R1 represents an alkyl group or alkenyl group having 8 to 22 carbon atoms, ^R2 represents an alkyl group having 1 to 3 carbon atoms, m and n represent the average number of moles of ethyleneoxy groups added, each of which is independently a number of 0.5 to 10. ^R3 represents an alkyl group having 1 to 3 carbon atoms.)
[2] The antistatic agent for glass fibers according to [1], which is liquid at room temperature.
[3] A sizing agent for glass fibers, comprising the antistatic agent for glass fibers according to [1] or [2].
[4] The glass fiber sizing agent according to [3], further comprising a film-forming agent, a lubricant, and a silane coupling agent.
[5] A glass fiber having a plurality of glass fiber monofilaments and a coating formed by applying the glass fiber sizing agent according to [3] or [4] to the glass fiber monofilaments.
[6] A resin molding comprising the glass fiber according to [5] and a thermosetting resin.

According to the present invention, it is possible to provide an antistatic agent for glass fibers that exhibits excellent antistatic performance and causes little coloring of glass fibers even after exposure to high temperatures. The present invention also provides a sizing agent for glass fibers that contains the antistatic agent.

Hereinafter, an embodiment of the present invention will be described, but the present invention is not limited to the following embodiment.

（式中、Ｒ^１は、炭素数８以上２２以下のアルキル基又はアルケニル基を示し、Ｒ^２は、炭素数１以上３以下のアルキル基を示し、ｍ及びｎは、平均付加モル数を示し、それぞれ独立に０．５以上１０以下の数である。Ｒ^３は、炭素数１以上３以下のアルキル基を示す。） [Antistatic agent for glass fibers]
The antistatic agent for glass fibers used in the present invention contains a quaternary ammonium salt represented by the following general formula (1).

(In the formula, ^R1 represents an alkyl group or alkenyl group having 8 to 22 carbon atoms, ^R2 represents an alkyl group having 1 to 3 carbon atoms, m and n represent the average number of moles added and are each independently a number of 0.5 to 10. ^R3 represents an alkyl group having 1 to 3 carbon atoms.)

Specific examples of the alkyl group having 8 to 22 carbon atoms include an n-octyl group, an n-decyl group, a dodecyl group (lauryl group), a tridecyl group, a tetradecyl group (myristyl group), a hexadecyl group (palmityl group), an octadecyl group (stearyl group), an eicosyl group, a docosyl group (behenyl group), a tetracosyl group, etc. Specific examples of the alkenyl group having 8 to 22 carbon atoms include an octenyl group, a nonenyl group, a decenyl group, a dodecenyl group, a tridecenyl group, a tetradecenyl group, a pentadecenyl group, a hexadecenyl group, a heptadecenyl group, an octadecenyl group, an eicosenyl group, a docosenyl group, a tetracosenyl group, etc., which may have a branched structure or a cyclic structure.
Among these, from the viewpoint of imparting appropriate antistatic properties, alkyl or alkenyl groups having 8 to 18 carbon atoms are preferred, with dodecyl, isotridecyl, tetradecyl, hexadecyl and octadecyl groups being particularly preferred.

In general formula (1), m and n represent the average number of moles of ethylene oxide added, and from the viewpoint that the quaternary ammonium salt is liquid at a high concentration and migrates to the surface of the strand to improve antistatic performance, each of them is independently 0.5 or more, preferably 1.0 or more, and from the same viewpoint, 10 or less, preferably 5 or less, and more preferably 3 or less. Also, from the viewpoint of improving antistatic performance, m+n is 1 or more, preferably 1.5 or more, and from the same viewpoint, 20 or less, preferably 5 or less, and more preferably 3 or less.

In the general formula (1), ^R2 and ^R3 each represent an alkyl group having a carbon number of 1 to 3. Examples include a methyl group, an ethyl group, and a propyl group, and the most preferred is an ethyl group.

There are no particular limitations on the method for producing the quaternary ammonium salt used in the present invention, but it can be produced by reacting a polyoxyethylene aliphatic amine, which is an aliphatic amine to which ethylene oxide has been added, with a dialkyl sulfate.

Examples of polyoxyethylene aliphatic amines include, but are not limited to, one or more aliphatic amines selected from the group consisting of octyldiethanolamine, decyldiethanolamine, lauryldiethanolamine, myristyldiethanolamine, palmityldiethanolamine, stearyldiethanolamine, and oleyldiethanolamine, coconut alkyldiethanolamine, polyoxyethylene cocoamine, polyoxyethylene tallow alkylamine, etc.

Examples of dialkyl sulfates include, but are not limited to, dimethyl sulfate, diethyl sulfate, and dipropyl sulfate.

The reaction temperature when reacting the polyoxyethylene aliphatic amine with the dialkyl sulfate is preferably 50°C or higher, more preferably 60°C or higher, and preferably 100°C or lower, more preferably 90°C or lower, and even more preferably 80°C or lower, in order to allow the reaction to proceed quickly.

The reaction molar ratio of polyoxyethylene aliphatic amine (a) and dialkyl sulfate (b) is preferably (a)/(b) = 0.1 to 1.2, more preferably 0.5 to 1.0, and even more preferably 0.7 to 1.0. In particular, a reaction molar ratio of 1.0 or less is preferable because the viscosity of the reaction product decreases due to the influence of unreacted compounds, which migrate to the surface and make the antistatic properties more effective.

If the reaction product containing a quaternary ammonium salt is in a solid or gel state at room temperature, the antistatic properties will be insufficient, so it is preferable that it is in a liquid state at room temperature. In this case, room temperature is 25°C.

The antistatic agent for glass fibers of the present invention can be mixed into a bundling agent or can be applied directly to glass strands. In either case, it can impart excellent antistatic properties to the glass strands.

[Glass fiber sizing agent]
When the antistatic agent for glass fibers of the present invention is used by adding it to a sizing agent, the sizing agent is not particularly limited, and a commonly used sizing agent may be used depending on the type of glass fiber and its application. The sizing agent is usually an aqueous liquid containing 1 to 20 parts by mass of a film-forming agent such as a starch-based, cellulose-based, or synthetic resin emulsion-based agent. When the antistatic agent for glass fibers of the present invention is used by adding it to a sizing agent, the amount added is preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass, and even more preferably 3 to 10 parts by mass, based on 100 parts by mass of the active ingredient of the film-forming agent. That is, if the amount of the antistatic agent added is too small, the antistatic property cannot be fully exhibited, and conversely, if it is too large, the antistatic property may be saturated and the sizing property of the glass strand may decrease.

As the film-forming agent of the bundling agent to which the antistatic agent for glass fibers of the present invention is added, a synthetic resin emulsion-based film-forming agent is preferred from the viewpoint of antistatic effect. Examples of synthetic resin emulsion-based film-forming agents include polyvinyl acetate emulsion, vinyl acetate/(meth)acrylic acid ester copolymer emulsion, ethylene/vinyl acetate copolymer emulsion, poly(meth)acrylic acid ester emulsion, epoxy resin emulsion, urethane resin emulsion, etc.

When the antistatic agent for glass fibers of the present invention is added to a sizing agent, it may contain other additives. Such other components include silane coupling agents, lubricants, surfactants, etc.

Examples of silane coupling agents include vinyl-based silanes such as vinyltrichlorosilane, vinyltris-β-methoxyethoxysilane, and vinyltriethoxysilane; amino-based silanes such as aminomethyltriethoxysilane, aminopropyltrimethoxysilane, diaminopropyldiethoxysilane, triaminopropylethoxysilane, and γ-aminopropyltriethoxysilane; methacryloxy-based silanes such as γ-methacryloxypropyltrimethoxysilane; epoxy-based silanes such as β-3,4-epoxycyclohexylethyltrimethoxysilane and γ-glycidoxypropyltrimethoxysilane; and mercapto-based silanes such as γ-mercaptopropyltrimethoxysilane. The amount of the silane coupling agent to be blended is about 0.2 to 20 parts by mass per 100 parts by mass of the active ingredient of the film-forming agent in the bundling agent.

Examples of lubricants include aliphatic hydrocarbons such as paraffin wax; aliphatic alcohols such as lauryl alcohol, palmityl alcohol, and stearyl alcohol; aliphatic amides such as palmitic acid amide and stearic acid amide; and fatty acid esters such as butyl stearate, octyl stearate, and fatty acid triglycerides. The amount of lubricant to be blended is about 0.5 to 10 parts by mass per 100 parts by mass of the active ingredient of the film-forming agent in the bundling agent.

Examples of surfactants include polyoxyalkylene alkyl ethers, polyethylene glycol propylene oxide adducts, polypropylene glycol ethylene oxide adducts, glycerin fatty acid esters or their ethylene oxide adducts, sorbitan fatty acid esters or their ethylene oxide adducts, alkyl polyglucosides, fatty acid monoethanolamides or their ethylene oxide adducts, fatty acid diethanolamides or their ethylene oxide adducts, sucrose fatty acid esters, polyglycerin fatty acid esters, polyethylene glycol fatty acid esters, fatty acid methyl ester ethoxylates, and weak acid salts of partial fatty acid amides of polyethylene polyamines. The amount of surfactant to be added is about 0.2 to 20 parts by mass per 100 parts by mass of the active ingredient of the film-forming agent in the bundling agent.

When the antistatic agent for glass fibers of the present invention is applied directly to glass strands without being mixed with a sizing agent, the step of applying the antistatic agent is preferably performed after the sizing agent is applied to the glass strands, and more preferably after the glass strands are dried and before they are cut. In this case, it is preferable to apply the antistatic agent as an aqueous solution of 1 to 50 parts by mass. The amount of the antistatic agent applied to the glass strands is preferably 0.005 to 0.5% by mass relative to the glass strands. In addition, the aqueous solution of the antistatic agent may be mixed with the lubricant or surfactant.

[Glass fiber]
The glass fiber of the present invention is characterized by having a plurality of glass fiber monofilaments and a coating formed by applying the above-mentioned glass fiber sizing agent to the glass fiber monofilaments.

The glass fiber of the present invention can be obtained, for example, as follows. First, molten glass is drawn from multiple nozzles provided at the bottom of a platinum bushing to form 30 to 6,000 glass fiber monofilaments. Next, the above-mentioned glass fiber sizing agent is applied to these glass fiber monofilaments using an applicator or the like, and these glass fiber monofilaments are gathered into a single bundle using a gathering shoe to form a glass fiber strand, which is then wound up on a collet to form a cake. The cake is then placed in a dryer and heated at 80 to 130°C for about 1 to 30 hours to evaporate the solvent (volatile matter) contained in the glass fiber sizing agent, forming a solid film that covers the surface of the glass fiber monofilaments. This results in the glass fiber wound up on the cake.

The dried glass fibers are pulled out of the cake and cut into lengths of approximately 1 to 40 mm to become chopped strands.

As the glass that constitutes the glass fiber, glass of any composition can be used, such as E glass, A glass, S glass, D glass, NCR glass, NE glass, etc.

If the glass fiber monofilaments constituting the glass fiber of the present invention have a fiber diameter of 3 to 30 μm, the chopped strands and the thermosetting resin can be mixed uniformly in the BMC method. The average diameter of the glass fiber monofilaments may be measured using an optical microscope or a laser measuring device.

The glass fiber of the present invention preferably has a mass ratio of the glass fiber sizing agent, i.e., ignition loss, of 0.2 to 3.0 mass% when the volatile substances are completely volatilized by applying the glass fiber sizing agent and drying. If the ignition loss of the glass fiber sizing agent applied to the glass fiber surface is too small, the above-mentioned properties may not be fully exhibited. On the other hand, if the ignition loss of the glass fiber sizing agent applied to the glass fiber surface is too large, the above-mentioned properties are not improved despite an increase in the amount applied, and it is not economical. The ignition loss is more preferably 1.0 to 2.0 mass%. The ignition loss of the glass fiber sizing agent on the glass fiber can be measured in accordance with JIS R 3420 (2013) 7.3.2.

[Resin molding]
Next, the resin molded product of the present invention will be described.
The resin molded product of the present invention is characterized by containing the above-described glass fiber and a thermosetting resin.

The resin molded body of the present invention is produced by the SMC method, which is produced by pressing a laminate of sheets containing glass chopped strands and a thermosetting resin, or the BMC method, which is produced by pouring a mixture of glass chopped strands and a thermosetting resin compound into a pot of a mold, pushing it with a plunger, and molding it by heating and pressurizing it.

The content of chopped strands in the resin molded body is preferably 10 to 40% by mass. If the content of chopped strands is too low, the content of chopped strands will be insufficient, and the reinforcing effect may not be sufficient. On the other hand, if the content of chopped strands is too high, the chopped strands and the thermosetting resin may not be uniform, or the shape of the resin molded body may not be maintained. The content of chopped strands is more preferably 15 to 30% by mass.

The present invention will now be described with reference to examples, but the present invention is not limited to these examples.

<Production of Quaternary Ammonium Salt>
Production Example 1
342.2 g of coconut alkyl diethanolamine was placed in a 500 mL four-neck flask, and the temperature was raised to 80° C. under nitrogen bubbling. 157.8 g of diethyl sulfate was then added dropwise from a dropping funnel over 120 minutes. After the completion of the dropping, the mixture was allowed to react for 60 minutes to obtain a yellow to reddish brown transparent liquid containing dihydroxyethyl ethyl cocoalkyl ammonium ethyl sulfate. The reaction rate (quaternization rate) in this reaction was 85%.

Production Example 2
A 500 mL four-neck flask was charged with 338.0 g of lauryldiethanolamine, and the temperature was raised to 80° C. under nitrogen bubbling, and then 162.0 g of diethyl sulfate was added from a dropping funnel in the same manner as in Production Example 1, to obtain a yellow to reddish brown transparent liquid containing dihydroxyethyl ethyl lauryl ammonium ethyl sulfate. The reaction rate (quaternization rate) in this reaction was 85%.

Production Example 3
A yellow to reddish brown transparent liquid containing dipolyoxyethylene ethyl cocoalkyl ammonium ethyl sulfate was obtained in the same manner as in Production Example 1, except that 354.9 g of polyoxyethylene (5) cocoalkylamine and 144.8 g of diethyl sulfate were mixed into a 500 mL four-neck flask. The reaction rate (quaternization rate) in this reaction was 100%.

Production Example 4
A yellow to reddish brown transparent liquid containing dipolyoxyethylene ethyl cocoalkyl ammonium ethyl sulfate was obtained in the same manner as in Production Example 1, except that 438.0 g of polyoxyethylene (20) cocoalkylamine and 59.1 g of diethyl sulfate were mixed into a 500 mL four-neck flask. The reaction rate (quaternization rate) in this reaction was 100%.

Production Example 5
A yellow to reddish brown transparent liquid containing dipolyoxyethylene ethyl tallow alkyl ammonium ethyl sulfate was obtained in the same manner as in Production Example 1, except that 439.4 g of polyoxyethylene (20) tallow alkyl amine and 60.6 g of diethyl sulfate were mixed into a 500 mL four-neck flask. The reaction rate (quaternization rate) in this reaction was 100%.

<Preparation of glass fiber sizing agent>
Example 1
A glass fiber sizing agent 1 was prepared by dissolving the quaternary ammonium sulfate, dihydroxyethyl ethyl cocoalkylammonium ethyl sulfate obtained in Production Example 1 at 0.8 mass %, polyvinyl acetate resin Movinyl 350 (manufactured by Japan Coating Resins Co., Ltd.) at 10 mass % (solids content equivalent, the same applies below), polyurethane resin Bondic 2220 (manufactured by DIC Corporation) at 1 mass %, and silane coupling agent A-174 (manufactured by Momentive Performance Materials Japan, LLC) at 0.5 mass % with deionized water.

Example 2
Glass fiber sizing agent 2 was prepared in the same manner as in Example 1, except that dihydroxyethyl ethyl lauryl ammonium ethyl sulfate obtained in Production Example 2 was used as the quaternary ammonium sulfate.

Example 3
Glass fiber sizing agent 3 was prepared in the same manner as in Example 1, except that dipolyoxyethylene (n=2, m=3) ethyl cocoalkylammonium ethyl sulfate obtained in Production Example 3 was used as the quaternary ammonium sulfate.

Example 4
Glass fiber sizing agent 4 was prepared in the same manner as in Example 1, except that dipolyoxyethylene (n, m = 10) ethylstearylammonium ethyl sulfate obtained in Production Example 4 was used as the quaternary ammonium sulfate.

Example 5
Glass fiber sizing agent 5 was prepared in the same manner as in Example 1, except that dihydroxyethyl ethylstearyl ammonium ethyl sulfate obtained in Production Example 5 was used as the quaternary ammonium sulfate.

(Comparative Example 1)
A glass fiber sizing agent 6 was prepared in the same manner as in Example 1, except that lauryl dimethyl ethyl ammonium ethyl sulfate was used as the quaternary ammonium sulfate.

(Comparative Example 2)
Glass fiber sizing agent 7 was prepared in the same manner as in Example 1, except that octyldimethylethylammonium ethyl sulfate was used as the quaternary ammonium sulfate.

Glass fiber sizing agents 1 to 7 were applied to a glass fiber monofilament having an average diameter of 13 μm with an applicator so that the ignition loss was 1.0 mass %, and 300 glass fiber monofilaments were bundled into one to obtain a glass fiber. The glass fiber was then wound as a cake on a collet, and the glass fiber sizing agent applied to the glass fiber was dried at a temperature of 140°C for 10 hours, after which the glass fiber was removed from the cake, yarned, and wound to obtain a glass roving strand with a count of 4800 tex. The glass roving strand was then cut to obtain chopped strands with a length of 25 mm.

The amount of charge on the chopped strands and the appearance color of a resin molded article produced using the chopped strands were evaluated by the following methods. The results are shown in Table 1.
The amount of charge was measured by measuring the charged voltage of the chopped strands one minute after the glass fibers had been cut using a static electricity measuring device, Statiron DZ4 (manufactured by Shishido Electrostatic Corporation).
The appearance color was evaluated by visually inspecting the appearance of a resin molded body produced by the SMC method using a bathtub compound (75% by mass) made of unsaturated polyester resin, calcium carbonate, and aluminum hydroxide, and a sheet made of chopped strands (25% by mass). If the desired color was obtained as a result of the visual inspection, it was marked with "◯", and if the desired color was not obtained, it was marked with "X".

As shown in Table 1, the chopped strands of Examples 1 to 6 all had excellent antistatic properties and appearance.
In contrast, the chopped strands of Comparative Examples 1 and 2 did not have sufficient antistatic properties.

Claims (5)

A reaction product of lauryldiethanolamine, coconut alkyldiethanolamine, or polyoxyethylene coconut alkylamine with diethyl sulfate,
Contains a quaternary ammonium salt represented by the following general formula (1) :
An antistatic agent for glass fibers , comprising the above reactant which is liquid at room temperature .

(In the formula, ^R1 represents an alkyl group or an alkenyl group having 8 to 22 carbon atoms, ^R2 represents an ethyl group , m and n represent the average number of moles of ethyleneoxy groups added, each of which is independently a number of 0.5 to 10, and ^R3 represents an ethyl group .) A sizing agent for glass fibers, comprising the antistatic agent for glass fibers according to claim 1 . The glass fiber sizing agent according to claim 2 , further comprising a film-forming agent, a lubricant and a silane coupling agent. 4. A glass fiber comprising a plurality of glass fiber monofilaments and a coating formed by applying the glass fiber sizing agent according to claim 2 or 3 to the glass fiber monofilaments. A resin molding comprising the glass fiber according to claim 4 and a thermosetting resin.