JPH05330860A - Sizing agent of glass fiber - Google Patents

Abstract

PURPOSE:To improve antistatic performance by dispersing a cationic copolymer containing an ethylene structural unit and an acrylamide structural unit expressed by specified formulae and having specified weight average mol.wt. in water. CONSTITUTION:Ethylene-acrylate acrylic acid group copolymer is allowed to react with an N,N-dialkylamino alkylamine to obtain an acrylamide copolymer. Then the obtd. copolymer is modified to cation by using an agent to produce quaternary compd. such as alkyl halide to isolate a linear cationic copolymer. The linear cationic copolymer has 1000-50000 weight average mol.wt. and contains 65-99mol% ethylenic structural unit expressed by formula I, 1-35mol% acrylamide structural unit expressed by formula II, and 0-15mol% acrylate structural unit expressed by formula III. This copolymer is dispersed in water to obtain the sizing agent of glass fiber. In formula II, R<2> is an alkylene of 2-8C, R<3> and R<4> are alkyl groups of 1-4C, R<5> is alkyl of 1-12C, arylalkyl of 6-12C, or alicyclic alkyl of 6-12C, and X<-> is halogen ion, CH3OSO<->3, or CH3 CH2OSO<->3. In formula III, R<1> is alkyl of 1-4C.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a sizing agent for glass fibers.

[0002]

BACKGROUND OF THE INVENTION Since glass fibers are inherently brittle, they are easily cut when scratched. Especially because it is vulnerable to friction,
It is necessary to avoid direct contact between monofilaments.
Therefore, various glass fiber sizing agents have been conventionally used.

Conventionally used glass fiber sizing agents include those of starch type and resin emulsion type. As the resin emulsion-based sizing agent, polyvinyl acetate, ethylene-vinyl acetate copolymer resin, polyester resin, epoxy resin, polyacrylic acid resin, polyurethane resin and the like are used.

These glass fiber sizing agents play a role of protecting the glass fibers from abrasion during rewinding, twisting, winding, and weaving in the glass fiber manufacturing process, and preventing fluffing, yarn breakage, and the like.

Another drawback of glass fibers is that they are easily charged. Due to this charging property, the glass fiber causes troubles due to electrostatic charge in the spinning and processing steps. In order to prevent the occurrence of this trouble, an antistatic agent is widely used in the glass fiber together with the sizing agent. Antistatic agents include inorganic and organic ones, inorganic antistatic agents include chlorides such as lithium chloride and aluminum chloride, and organic antistatic agents include triethanolamine carboxylate and sulfonate. , Sulfuric acid ester, phosphoric acid ester, ethylene oxide adduct of alkyl amine, imidazoline, amine amide and its salt obtained from higher fatty acid and lower polyamine, and quaternary ammonium salt such as alkyl trimethyl ammonium salt.

[0006]

However, when the antistatic agent is used together with the sizing agent as described above, the antistatic agent inhibits the adsorption of the sizing agent to the glass fiber, and the lubricating performance of the sizing agent itself. There is a problem that it inhibits.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a glass fiber sizing agent having a sufficient sizing action, antistatic ability and lubricating performance. It is to be.

[0008]

In order to achieve the above object, the glass fiber sizing agent of the present invention contains 65 to 99 mol% of the ethylene structural unit (I) represented by the general formula 4 in the molecule. And an acrylamide structural unit (I
II) is contained in an amount of 1 to 35 mol% and a dispersion of a linear cationic copolymer having a weight average molecular weight of 1,000 to 50,000 is contained. Each structural unit may be arranged regularly or irregularly.

[0009]

[Chemical 4]

[0010]

[Chemical 5]

(However, in the chemical formula 5, R ² has 2 to 2 carbon atoms.
8 represents an alkylene group, R ³ and R ⁴ each independently represent an alkyl group having 1 to 4 carbon atoms, and R ⁵ represents 1 to 12 carbon atoms.
Represents an alkyl group having 6 to 12 carbon atoms, an arylalkyl group having 6 to 12 carbon atoms, or an alicyclic alkyl group having 6 to 12 carbon atoms, and X ⁻ represents a halogen ion, CH ₃ OSO ₃ ^— or CH ₃ CH ₂ OS.
Representing O ₃ ⁻ , R ^{2 to} R ⁵ and X ⁻ may be the same or different for each structural unit. ) In the glass fiber sizing agent of the present invention, the cationic copolymer further comprises an acrylate structural unit (I
The composition may contain I) in an amount of 15 mol% or less.

[0012]

[Chemical 6]

(However, in the chemical formula 6, R ¹ is 1 to ¹ carbon atoms.
4, R ¹ may be the same or different for each structural unit. In the present specification, the term "dispersion" includes macroscopically uniform systems such as those obtained by emulsifying the above cationic copolymer in water, those solubilized, and those dispersed. It is a concept.

The constitution of the cationic copolymer used in the glass fiber sizing agent of the present invention will be described in more detail below.

In the above cationic copolymer, the ethylene structural unit (I) represented by the general formula 4 has 6 units in the molecule.
It is contained at 5 to 99 mol%, but this content ratio is 6
If it is less than 5 mol%, the softening point of the cationic copolymer is lowered, and the lubricity of the obtained sizing agent under high temperature or high humidity is lowered. When the content of the ethylene structural unit (I) exceeds 99 mol%, the acrylamide structural unit (II
The content of (I) becomes smaller and the acrylamide structural unit (II
The antistatic effect due to I) cannot be obtained. From the viewpoint of lubricity and antistatic ability, ethylene structural unit (
More preferably, I) is contained in an amount of 85 to 97 mol%.

In the cationic copolymer used for the glass fiber sizing agent of the present invention, the acrylamide structural unit (III) represented by the general formula 5 is a cationic acrylamide structural unit having a quaternary ammonium salt. And
It is contained at 1 to 35 mol% in the molecule. When the content ratio is less than 1 mol%, sufficient antistatic ability cannot be imparted, and when the content ratio exceeds 35 mol%, hygroscopicity occurs in the cationic copolymer. The humidity dependence of the antistatic ability becomes large, and even tackiness due to tack occurs. From the viewpoints of antistatic ability, humidity dependency and tackiness, the content of the acrylamide structural unit (III) is more preferably 3 to 15 mol%.

The acrylamide structural unit (II
In I), R ² represents an alkylene group having 2 to 8 carbon atoms. Specific examples of R ² include an ethylene group, a propylene group, a hexamethylene group and a neopentylene group. These alkylene groups may be mixed in one molecule. Among these alkylene groups, an ethylene group and a propylene group are preferable, and a propylene group is particularly preferable, from the viewpoint of ease of production and economy.

R ³ and R ⁴ of the acrylamide structural unit (III) each independently represent an alkyl group having 1 to 4 carbon atoms. These alkyl groups may be mixed in one molecule. Specific examples of R ³ and R ⁴ include a methyl group, an ethyl group, a propyl group and a butyl group. Among these alkyl groups, a methyl group and an ethyl group are preferable from the viewpoint of antistatic effect.

R ⁵ of the acrylamide structural unit (III) is
It represents an alkyl group having 1 to 12 carbon atoms, an arylalkyl group having 6 to 12 carbon atoms, or an alicyclic alkyl group having 6 to 12 carbon atoms. These alkyl groups may be mixed in one molecule. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an n-octyl group and an n-lauryl group. Specific examples of the arylalkyl group include a benzyl group and a 4-methylbenzyl group. Specific examples of the alicyclic alkyl group include a cyclohexyl group and a methylcyclohexyl group. Of these, a linear alkyl group and an arylalkyl group are preferable as R ⁵ from the viewpoint of tackiness, and a lower alkyl group is preferable from the viewpoint of antistatic ability. Of these, a methyl group and an ethyl group are particularly preferable as R ⁵ .

X in the acrylamide structural unit (III)
^{- is, Cl -, Br -, I} - halogen such as ions, C
H ₃ OSO ₃ ⁻ or CH ₃ CH ₂ OSO ₃ ⁻ is represented, and these anions may be mixed in one molecule. Among these anions, from the viewpoint of economy, Cl ⁻ , CH
₃ OSO ₃ ⁻ and CH ₃ CH ₂ OSO ₃ ⁻ are preferred.

Further, the cationic copolymer used in the glass fiber sizing agent of the present invention contains the acrylate structural unit (II) represented by the general formula 6 in an amount of 15 mol% or less in the molecule. Good. It is preferable to contain the acrylate structural unit (II) because the film-forming ability is increased and the adhesiveness to the glass fiber is increased. When the content ratio of the acrylate structural unit (II) exceeds 15 mol%, the softening point of the cationic copolymer is lowered, resulting in poor lubricity. The preferred content of the acrylate structural unit (II) is 1 to 15 mol%, and above all, 3 to 7 mol%.

In the acrylate structural unit (II) represented by the general formula 6, R ¹ represents an alkyl group having 1 to 4 carbon atoms. Specific examples of R ¹ include methyl group, ethyl group, n-
Propyl group, iso-propyl group, n-butyl group, is
An o-butyl group may be mentioned. These alkyl groups may be mixed in one molecule. Of these alkyl groups, a methyl group and an ethyl group are preferable from the viewpoint that they do not adversely affect the lubricity.

The weight average molecular weight of the cationic copolymer used in the glass fiber sizing agent of the present invention is measured by gel permeation chromatography (GPC),
Ultra high temperature GPC as polystyrene equivalent weight average molecular weight
Method (Kinukawa, Journal of Polymer Science, Vol. 44, No. 2, 139-141)
Page, 1987). According to the measurement results, the preferable range of the weight average molecular weight is 1,000 to 5
It is 10,000. When the weight average molecular weight is less than 1,000, the molecular weight is too small and the film forming ability as a sizing agent is poor, and the function as a glass fiber sizing agent, which is the object of the present invention, cannot be sufficiently exhibited. Therefore, the occurrence of fluffing of the glass fiber becomes remarkable. When the weight average molecular weight of the cationic copolymer exceeds 50,000,
When it is made into a dispersion, the viscosity becomes too large, and the workability deteriorates. The preferred weight average molecular weight range of the cationic copolymer is 3,000 to 30,000.

The cationic copolymer used in the glass fiber sizing agent of the present invention can be produced, for example, as follows. That is, an ethylene-acrylic acid ester copolymer obtained by copolymerizing ethylene and an acrylic acid ester by a high-pressure polymerization method is hydrolyzed simultaneously with hydrolysis by the method described in JP-A-60-79008. To a desired molecular weight. By partially carrying out this hydrolysis reaction, an ethylene-acrylic acid ester-acrylic acid copolymer can be obtained from the ethylene-acrylic acid ester copolymer. Further, the obtained ethylene-acrylic acid ester-acrylic acid copolymer is amidated with N, N-dialkylaminoalkylamine or the like to obtain an acrylamide-based copolymer, which is then treated with an alkyl halide, dialkyl sulfuric acid or the like. The above cationic copolymer can be obtained by cation modification with a quaternizing agent and isolation. Incidentally, by completely hydrolyzing the above-mentioned ethylene-acrylic acid ester copolymer, the acrylate structural unit (I
A cationic copolymer containing no I) is obtained.

The glass fiber sizing agent of the present invention can be obtained by dispersing the above-mentioned cationic copolymer in water.
For example, it can be obtained by emulsifying the above-mentioned cationic copolymer in water by a high pressure emulsification method. In the high pressure emulsification method, the cationic copolymer is charged into an autoclave together with water and stirred under pressure at a temperature of 110 to 140 ° C. to obtain a glass fiber sizing agent as an emulsion. The cationic copolymer can be made into a dispersion without using a surfactant, but a surfactant may be added at the time of emulsification, solubilization and dispersion.

The glass fiber sizing agent of the present invention contains a dispersion of the above-mentioned cationic copolymer, but a sufficient effect can be obtained by using the dispersion alone. However, in order to improve the adhesiveness of the glass surface with the glass fiber sizing agent,
The surface of the glass fiber may be treated with a known silane coupling agent. Examples of the silane coupling agent include vinyl-based silanes such as vinyltrichlorosilane, vinyltris-β-methoxyethoxysilane, and vinyltriethoxysilane, amino-based silanes such as γ-aminopropyltriethoxysilane, and γ-methacryloxypropyltrimethoxy. Methacryloxy silane such as silane, β-3,
Epoxy-based silanes such as 4-epoxycyclohexylethyltrimethoxysilane and γ-glycidoxypropyltrimethoxysilane, and mercapto-based silanes such as γ-mercaptopropyltrimethoxysilane can be used.

The glass fiber sizing agent of the present invention may contain known lubricants such as aliphatic hydrocarbons, aliphatic alcohols, aliphatic amides and higher fatty acid esters. For example, paraffin wax can be used as the aliphatic hydrocarbon, lauryl alcohol, stearyl alcohol can be used as the aliphatic alcohol, and palmitic acid amide, stearic acid amide can be used as the aliphatic amide. it can. Examples of the higher fatty acid ester include saturated or unsaturated higher monocarboxylic acid, dicarboxylic acid or oxycarboxylic acid, monohydric alcohol such as butanol and octanol, or polyhydric acid such as ethylene glycol, glycerin, pentaerythritol and sorbitol. The thing by the combination with a polyhydric alcohol can be mentioned.

The glass fiber sizing agent of the present invention can be used in a general coating process in the same manner as a conventional glass fiber sizing agent. That is, a glass fiber sizing agent is applied to a glass fiber immediately after spinning using a roller coater, wound as a glass fiber strand, and then dried under predetermined drying conditions. The amount of the glass fiber sizing agent attached to the glass fibers is preferably 0.1 to 2% based on the weight of the glass fibers.

[0029]

The glass fiber sizing agent of the present invention contains a cationic copolymer having an ethylene structural unit as a main component, and the ethylene structural unit contributes to the formation of a film, and the adhesiveness to glass fiber and proper lubrication are provided. It is thought to give sexuality. In addition, the cationic copolymer has a quaternary alkylammonium salt bound through an amide group, and it is considered that the portion of this quaternary alkylammonium salt contributes to the antistatic ability. Be done. As a result, the glass fiber sizing agent of the present invention has an excellent balance of glass fiber sizing function, lubricity and antistatic ability.

[0030]

The glass fiber sizing agent of the present invention is excellent in the balance of glass fiber sizing function, lubricity, and antistatic ability, and therefore, during rewinding, twisting, winding, and weaving in the glass fiber manufacturing process. Protects the glass fibers from abrasion, prevents fluffing, yarn breakage, and the like, and prevents troubles due to the charging of the glass fibers.

[0031]

EXAMPLES Examples of the glass fiber sizing agent of the present invention will be described. First, a specific production example of the cationic copolymer used in the glass fiber sizing agent of the present invention will be described.

Production Example 1 (Preparation of Cationic Copolymer) 400 ml of xylene and ethylene / acrylic acid were placed in a 1-liter four-necked flask equipped with a thermometer, a stirrer, a dropping funnel and a Dean-Stark water separator. 150 g of an ethyl-acrylic acid copolymer (ethylene / ethyl acrylate / acrylic acid = 93/3/4) and 1.0 g of paratoluenesulfonic acid were charged.

Next, 21.1 g of N, N-dimethylaminopropylamine was charged and the temperature was adjusted to 140 ° C. using an oil bath.
The mixture was heated to 1, the water formed was continuously removed by azeotropic distillation with xylene, and the mixture was further reacted at 140 ° C. for 17 hours, and the amidation reaction was continued until no water was formed and no azeotropic distillation of water was observed. ..

458 g of the obtained reaction product was cooled to 80 ° C., and methyl iodide 2 was added to the reaction mixture from a dropping funnel.
8.7 g was gradually added dropwise over 1 hour. During this period, an exotherm was observed, but the reaction temperature was lowered to 90 ° C by cooling.
Maintained at. After completion of the dropping, an aging reaction was performed at 100 ° C. for 4 hours. The reaction product thus obtained was poured into a large amount of methanol, and the formed precipitate was recovered and dried to obtain a cationic copolymer.

The weight average molecular weight of this cationic copolymer was measured and found to be 19,400.

<Manufacturing Examples 2 to 9> In the same manner as in Manufacturing Example 1, the cationic copolymers shown in Manufacturing Examples 2 to 9 in Table 1 were prepared according to the method described in Japanese Patent Application No. 2-331082. Raw materials used in Production Examples 2 to 9 are as follows in Production Example 1
Is different from

In Production Examples 8 and 9, R in the ethylene / ethyl acrylate / acrylic acid copolymer as the raw material copolymer was used.
¹ is an n-propyl group and an n-butyl group, respectively,
In Production Examples 5 and 7, an ethylene / acrylic acid copolymer was used as the raw material copolymer. In Production Examples 4 and 8, N, N-dimethylaminoethylamine was used as the aminating agent,
In Production Example 6, N, N-dimethylaminoneopentylamine was used as the aminating agent, in Production Example 7, N, N-diethylaminopropylamine was used as the aminating agent, and in Production Example 9, N, N- was used as the aminating agent. Diethylaminoethylamine was used. In Production Examples 2, 5, 6 and 8, diethyl sulfate was used as a quaternizing agent, and Production Examples 4 and 9 were used.
In Example 3, benzyl chloride was used as the quaternizing agent, and in Production Example 3, p-methylbenzyl chloride was used as the quaternizing agent.

Table 1 shows R ^{1 to} R ⁵ and X ⁻ in each structural unit of the cationic copolymers of Production Examples 1 to 9, the molar ratio thereof and the weight average molecular weight.

[0039]

[Table 1]

Next, specific examples of the glass fiber sizing agent of the present invention and specific comparative examples for comparison and contrast with them will be described. <Examples 1 to 9> (Preparation of glass fiber sizing agent) Using the cationic copolymer produced in Production Example 1, a glass fiber sizing agent of Example 1 was prepared. In this glass fiber sizing agent, the cationic copolymer of Production Example 1 was charged into an autoclave together with water so that the solid content was 20%, and the temperature was kept at 120 ° C. under high temperature and high pressure of ^{2 to} 2.5 kg / cm ² for 2 hours. Obtained by stirring. Similarly, the cationic copolymers of Production Examples 2 to 9 were mixed with a solid content of 20%.
The glass fiber sizing agents of Examples 2 to 9 were obtained in the same manner as above.

Comparative Example Comparative Example 1 was a case where a conventionally known vinyl acetate type glass fiber sizing agent (commercially available product) containing no cationic antistatic agent was used. Comparative Example 2 was a case where a conventionally known vinyl acetate-based glass fiber sizing agent (commercially available product) containing a cationic antistatic agent was used.

<Performance evaluation test of glass fiber sizing agent> The glass fiber sizing agent of Examples 1 to 9 was diluted 5 times with water and used as a glass fiber sizing agent with a solid content of 4% by weight, The fluffiness and abrasion resistance were evaluated. The charge amount, fluffiness, and abrasion resistance serve as evaluation criteria for antistatic ability, adhesiveness, and lubricity, respectively. The evaluation results are shown in Table 2.

[0043]

[Table 2]

Details of each evaluation test are as follows. (1) Measurement of Charge Amount The glass fiber sizing agent diluted as described above is applied to a 10 μm / 200 filament glass fiber which is becoming fibrous with a roll coater, and after being bundled, it is wound on a collet as a strand and weighs 2 kg. It was a cake. This cake was heat-treated at 120 ° C. for 8 hours, and then 60 pieces of the cake were arranged and combined to prepare a roving. This was cut with a cutter to obtain a chopped strand having a length of 25 mm.
At this time, static electricity was not generated, and adhesion of glass fiber to the cutter was not seen. The electrification amount of this chopped strand accumulation part was measured using an electrostatic voltage detector under the conditions of 20 ° C. and 60% RH. The measurement results are shown in Table 2.

(2) Evaluation of fluffing The glass fibers were coated with a glass fiber sizing agent with a roll coater in the same manner as in the measurement of the charge amount in (1) above, and then 20
A yarn was prepared by combining 0 yarns. With respect to this yarn, the occurrence frequency of warp fluff and the number of tube fluff were evaluated. The warp fluff occurrence frequency represents the fluff ball occurrence frequency per minute of one bobbin when traveling at a predetermined speed with a predetermined load applied to the tensor. The number of tube fluffs is the number of fluffs on the surface while the tube is wound. The results of these evaluations are shown in Table 2.

(3) Wear resistance index The wear resistance index was measured using the same yarn as in (2) above. The wear resistance index is evaluated by a test machine prototyped by the present inventor for a predetermined system, and the higher this value is, the higher the wear resistance is. This tester is a system in which a specified tension is applied to the system and it is repeatedly moved back and forth while sandwiching it between dish-type compensators.The abrasion resistance index shows fluff on the part squeezed by the compensator. It is an index of the number of times to start.

From the results shown in Table 2, it can be seen that the glass fibers treated with the glass fiber sizing agent of each Example have much lower charge than those of Comparative Examples 1 and 2.
In addition, the frequency of warp fluff and the number of tube fluff are also lower than in Comparative Examples 1 and 2. Further, it can be seen that the wear resistance index of each example is larger than those of Comparative Examples 1 and 2, and the wear resistance is excellent.

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Claims (2)

[Claims] 1. An ethylene structural unit (I) represented by the general formula 1 in the molecule is
99 mol% and 1 to 35 mol% of the acrylamide structural unit (III) represented by the general formula 2 and having a weight average molecular weight of 100
A glass fiber sizing agent, characterized in that it contains a dispersion of a linear cationic copolymer of 0 to 50,000. [Chemical 1] [Chemical 2] (However, in Chemical formula 2, R ² represents an alkylene group having 2 to 8 carbon atoms, R ³ and R ⁴ each independently represent an alkyl group having 1 to 4 carbon atoms, and R ⁵ represents 1 to 4 carbon atoms. 12 alkyl group, arylalkyl group having 6 to 12 carbon atoms or 6 carbon atoms
To 12 alicyclic alkyl groups, X ⁻ represents a halogen ion, CH ₃ OSO ₃ ^— or CH ₃ CH ₂ OSO ₃ ^— , and R ^{2 to} R ⁵ and X ⁻ are the same for each structural unit. Or they may be different. ) 2. The cationic copolymer further comprises 15 mol% of an acrylate structural unit (II) represented by the general formula 3.
The glass fiber sizing agent according to claim 1, which is contained below. [Chemical 3] (However, in Chemical formula 3, R ¹ represents an alkyl group having 1 to 4 carbon atoms, and R ¹ may be the same or different for each structural unit.)