JPH09227172A - Binder for glass fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a binder for glass fibers capable of readily (quickly) being dissolved without heating, having excellent stability of its solution with the lapse of time and film-forming property, and capable of completely deoiling. SOLUTION: This binder for glass fibers is composed of a modified polyvinyl alcohol powder product having 8,000-390,000 weight-average molecular weight and is obtained by subjecting polyvinyl alcohol to Michael addition reaction with acrylamide and to hydrolysis treatment, and directly drying or drying after purified with a small amount of organic solvent, as a main component.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a sizing agent for glass fibers.

[0002]

2. Description of the Related Art Conventionally, a number of materials such as starch, modified starch, dextrin, amylose, carboxymethyl cellulose, polyvinyl alcohol (hereinafter referred to as "PVA"), etc. have been proposed as a main component constituting a sizing agent for glass fibers. There is.

[0003]

However, the conventional sizing agents for glass fibers cannot be said to have sufficient film-forming properties, and there is a problem in the occurrence of fluffing and slipperiness.

When starches are used, it takes a long time to completely dissolve them, and the stability of the solution with time is poor. The same applies to PVA, and it was necessary to heat and dissolve it in order to completely dissolve it.

Further, since these are difficult to thermally decompose in the deoiling process of glass fiber products, deoiling may be incomplete,
There was a problem that it took a considerable amount of time. An object of the present invention is to solve such a problem.

[0006]

The sizing agent for glass fibers according to claim 1 is a weight average molecular weight of 8,000 to 390, obtained by subjecting PVA to a Michael addition reaction of a vinyl compound.
000 modified PVA is contained.

The sizing agent for glass fibers according to claim 2 is P
A weight average molecular weight of 8,000 obtained by subjecting VA to a Michael addition reaction with a vinyl compound and then performing a hydrolysis treatment.
It contains ~ 390,000 modified PVA.

The sizing agent for glass fibers according to claim 3 is P
After the modified PVA having a weight average molecular weight of 8,000 to 390,000, which is obtained by subjecting VA to a Michael addition reaction with a vinyl compound or subjected to a hydrolysis treatment, is directly dried, or is purified with a small amount of an organic solvent. It contains a modified PVA powder product obtained by drying. The sizing agent for glass fibers according to claim 4 is the sizing agent for glass fibers according to any one of claims 1 to 3, wherein the vinyl compound is acrylamide and / or 2-acrylamido-2-methylpropanesulfonic acid. Alternatively, it is a salt thereof.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The degree of saponification of PVA used in the present invention is not particularly limited, but when a strong alkali is used as a catalyst, it is preferably 80% or more, more preferably 99% or more of a complete saponification product. This is to prevent the alkali of the catalyst from being consumed by saponification and to suppress the amount of by-products (acetate) generated by saponification.

The degree of polymerization of PVA is 50 to 8,000.
Are good, and 300 to 4,000 in terms of ease of production.
Is more preferred.

A modified product of PVA may be used as the reaction base (raw material) PVA. Examples of the modified product include carboxyl-modified PVA obtained by saponifying a copolymer of vinyl acetate and a dibasic acid such as maleic acid and itaconic acid, and a copolymer of vinyl acetate and 2-acrylamido-2-methylpropanesulfonic acid (salt) monomer. There is a sulfonic acid-modified PVA obtained by saponifying a polymer.

PVA may be dissolved in water in advance, or may be used in the reaction as a solid. When PVA is reacted in a solid state, the average particle size is preferably 1,000 μm or less. If it exceeds 1,000 μm, there is a possibility that the catalyst and the vinyl compound may not easily permeate.

The vinyl compound used in the present invention includes acrylonitrile, acrylamide, acrylic acid or a salt thereof, acrylic ester, and 2-acrylamide-2.
-Methyl propane sulfonic acid (AMPS) or its salts (for example sodium salt, potassium salt, ammonium salt), vinyl sulfonic acid or its salts, vinyl sulfoxide, vinyl sulfone, maleic acid, nonionics such as maleic acid diester, anionic vinyl. In addition to the compounds, cationic vinyl compounds such as N, N-dimethylaminoethyl acrylate or a quaternary salt thereof, N, N-dimethylaminopropyl acrylamide or a quaternary salt thereof can be mentioned. Moreover, these can also be used in combination of 2 or more types. Of these, acrylamide, acrylonitrile, 2-acrylamido-2-methylpropanesulfonic acid or a salt thereof is preferable because of its high reactivity.

The method for producing the modified PVA used in the present invention includes the following methods, but any method may be used. A) A method in which a vinyl compound is subjected to a Michael addition reaction in a PVA aqueous solution. B) A method in which a vinyl compound is subjected to a Michael addition reaction with PVA in a solvent suspension system. C) A method of performing a Michael addition reaction between solid PVA and a liquid vinyl compound under solid-liquid reaction conditions.

The above-mentioned "c) solid-liquid reaction conditions" means
In producing a modified PVA by reacting a solid type PVA with a liquid vinyl compound (or a vinyl compound solution), the solid type PVA is not dissolved (dissolved) in the vinyl compound through a reaction. This is a condition in which a chemical reaction with the vinyl compound proceeds while the solid state (powder state) is maintained to modify the PVA.

Among the above-mentioned production methods (a)-(b)-(c), the method (c-) is preferable in terms of reactivity, stability of the product, high purity and the like. The method (c) will be described in detail.

As a procedure of compounding, first, powdered PVA is used.
, A catalyst such as NaOH, KOH or triethylamine is added, and then a vinyl compound is added. The order of addition in the present invention is not limited to this, but in any case, it is desirable to add as uniformly as possible. In this case, a method of adding a drug under high-speed stirring of PVA, or a method of spray-adding a drug is also desirable for performing a uniform reaction. The amount of the catalyst used in the reaction is 0.5 to 100 mol% based on PVA,
The amount of the vinyl compound is preferably in the range of 1 to 150 mol%.

These are stirred with a horizontal blender while maintaining the solid form of PVA, and a Michael addition reaction is carried out for 30 minutes to 10 hours. Suitable temperatures for carrying out the Michael addition reaction are in the range from 5 to 90C, preferably from 20 to 70C.
It is in the range of ° C. Depending on the type of vinyl compound (eg, acrylonitrile, acrylamide, etc.), an alkali or the like may be added after this for hydrolysis. In this case, it can be partially hydrolyzed or completely hydrolyzed depending on the use. The hydrolyzate also corresponds to the modified PVA of the present invention.

For hydrolysis, NaOH, KOH, LiO
In addition to alkaline preparations such as H, Na ₂ CO ₃ and NH ₂ OH, alkylamines such as dimethylamine and alkanolamines such as monoethanolamine can be used.

Further, by replacing the system with nitrogen during the reaction, it is possible to prevent coloring of the product and breaking of the molecular chain by radicals.

The finally obtained product is dried as it is, or 1 to 1 part by weight of the modified PVA product is used.
A powder product (average particle size 150 to 1,000 μm) can be easily obtained by purifying with a small amount of 5 parts by weight of methanol or isopropyl alcohol and then drying (a known method can be used for drying).

Thus, in order to easily obtain a powder product after the reaction, the water content of the reaction system is 0 to 70% by weight throughout the reaction.
It is necessary to set the content to 0 to 50% by weight or less. If the water content of the reaction system exceeds 70% by weight, not only powdering becomes difficult but also the reaction rate is difficult to increase. Further, if the water content exceeds 70% by weight, it becomes difficult for PVA to maintain the powder state through the reaction. The closer the water content of the reaction system is to 0% by weight, the easier it is to obtain a powder product, and a higher reaction rate can be expected.

When the water content of the reaction system is 0% by weight, the vinyl compound is originally liquid, or even if a solid vinyl compound is used, it is dissolved using a solvent other than water. Also, the catalyst, whether it is solid or liquid, is used as it is, or is dissolved or diluted in a solvent other than water before use.

It is also possible to add a PVA insoluble solvent. The PVA-insoluble solvent refers to a solvent capable of forming a slurry (suspension) of PVA by dispersing PVA in the solvent without dissolving the same, and specifically, methanol, isopropyl alcohol, acetone, methyl ethyl ketone and the like. No. The addition of the PVA-insoluble solvent has the effect of preventing the PVA (including those already modified) from forming a dumpling (lump) during the reaction.

The amount of the PVA-insoluble solvent added is PV
0.1 to 5 parts by weight to A1 part by weight is appropriate. If it is less than this, the contribution to uniformity is small, and if it is more than this, it is difficult to form a slurry.

The modification ratio of the PVA modified product obtained by the above-mentioned production method can be determined by NMR or IR.
The modification ratio of the modified PVA obtained in this study was 0.5 to 45 mol%. Other means for determining the modification rate include colloid titration for anion modification and semi-micro Kjeldahl method for modification with a nitrogen-containing compound.

The range of the weight average molecular weight (measured by GPC) of the modified PVA in the present invention is 8,000 to 39.
It is 0000. If it is less than 8,000, when it is used as a sizing agent for glass fibers, there is a problem that the strength of the coating becomes small, and if it exceeds 390,000, the viscosity of the solution becomes too high and the workability deteriorates. There is a problem. The preferred range is 25,000-300,0.
00.

The eluent in GPC is 0.1
Four columns (TSKgel G2500PW, G3000PW, G4, manufactured by Tosoh Corporation) using a specified NaCl aqueous solution.
000PW, G5000PW) were connected in series and measured.

As the sizing agent of the present invention, other sizing agents such as starch, carboxymethyl cellulose, polyvinyl alcohol, polyacrylic acid, etc. are appropriately used as necessary within a range that does not adversely affect the effects of the present invention. be able to. Further, as other additives, plasticizers, emulsifiers, leveling agents, antistatic agents, lubricants and the like can be used as appropriate.

Since the sizing agent of the present invention contains the above-mentioned modified PVA as an essential component (main component), it has excellent solubility, has a large film forming ability, has a binder effect, and has a fluffing effect during weaving. Good smoothness and anti-electricity,
Furthermore, it is easily decomposed by heat in the deoiling process and is almost completely removed at low temperature. In addition, stability over time is also good.

Therefore, the glass cloth, roving cloth, and the like woven by the sizing agent of the present invention do not have an adverse effect in applications in which electrical characteristics are important.

Modified PVA obtained by using, for example, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid (AMPS) or a salt thereof as the vinyl compound.
Is composed of the following structural units.

(Acrylamide (when not hydrolyzed))

Embedded image .

(Acrylamide (when completely hydrolyzed))

Embedded image .

(Acrylamide (when partially hydrolyzed))

Embedded image .

(AMPS)

Embedded image .

(Acrylamide / AMPS (when completely hydrolyzed))

Embedded image

[0038]

EXAMPLES Production Example 1 PVA (Kuraray PVA-117) 440 having a polymerization degree of 1,700 when completely saponified was placed in a horizontal blender having a capacity of 4 liters.
g, powdered NaOH 12 g and acrylonitrile 26
5 g was added, and the mixture was stirred at 50 ° C. for 6 hours. At this time, the water content of the reaction system was 0% by weight. The product obtained is 500
After purification with g of isopropyl alcohol and drying, 660 g of white powder (average particle size 520 μm) was obtained. When the obtained powder was analyzed by NMR, the degree of cyanoethylation (modification rate) was 45 mol% and the reaction rate was 90%. The weight average molecular weight was measured by GPC.
It was 0000.

Production Example 2 PVA (Kuraray PVA-117) 440 having a polymerization degree of 1,700 when completely saponified was placed in a horizontal blender having a capacity of 4 liters.
g, 30% -NaOH aqueous solution 400 g and 50% -acrylamide aqueous solution 426 g were added, and the mixture was stirred at 20 ° C. for 4 hours. The water content of the reaction system at this time was 39% by weight. The obtained product was purified with 500 g of methanol and then dried to give 630 g of white powder (average particle size 400 μm).
m). When the obtained powder was analyzed by NMR,
The degree of carbamoylethylation (modification rate) was 23 mol%, and the reaction rate was 77%. The weight average molecular weight measured by GPC was 85,000.

Production Example 3 PVA (Kuraray PVA-124) 440 having a polymerization degree of 2,400 when completely saponified was placed in a horizontal blender having a capacity of 4 liters.
g, 30% -NaOH aqueous solution 200 g and 50% -acrylamide aqueous solution 284 g were added, and the mixture was added under N ₂ gas flow at 30%.
Stirred at C for 2 hours. The water content of the reaction system at this time was 31% by weight. Then add 50% -NaOH 50g,
Hydrolysis was performed at 90 ° C. for 1 hour. At this time, the water content of the reaction system was 32%. The product obtained is dried directly,
610 g of white powder (average particle size 630 μm) was obtained. When the obtained powder was analyzed by NMR and IR, the carbamoylethylation degree was 2 mol%, the carboxyethylation degree was 13 mol% (total modification rate was 15 mol%), and the reaction rate was 75%. The weight average molecular weight was measured by GPC and found to be 120,000.

Production Example 4 PVA (Kuraray PVA-205) 490 having a saponification degree of 88% and a polymerization degree of 500 was placed in a horizontal blender having a capacity of 4 liters.
g, 50% -NaOH aqueous solution 320 g, acrylic acid 23
5 g and isopropyl alcohol 200 g (vs PVA
0.4 times the amount) was added and the mixture was stirred in a slurry state at 60 ° C. for 8 hours. The water content of the reaction system at this time was 13% by weight.
The obtained product was purified with 300 g of methanol and then dried to obtain 640 g of white powder (average particle size: 590 μm). When the obtained powder was analyzed by colloid titration, the degree of carboxyethylation (modification rate) was 16 mol% and the reaction rate was 64%. The weight average molecular weight measured by GPC was 22,000.

Production Example 5 To a 4-liter horizontal blender, 440 g of PVA having a polymerization degree of 4,000 when completely saponified, 280 g of 50% -NaOH aqueous solution and 828 g of 50% 2-acrylamido-2-methylpropanesulfonic acid aqueous solution were added. , 80 ° C
For 5 hours. The water content of the reaction system at this time was 36%. The obtained product was purified with 500 g of isopropyl alcohol and then dried to obtain 710 g of white powder (average particle size 650 μm). As a result of NMR analysis, the obtained powder had a sulfo group modification ratio of 14 mol% and a reaction ratio of 70%.
Met. In addition, the weight average molecular weight measured by GPC was 220,000.

Production Example 6 PVA (Kuraray PVA-124) 440 having a polymerization degree of 2,400 when completely saponified was placed in a horizontal blender having a capacity of 4 liters.
g, 40% -NaOH aqueous solution 150 g, and 50% N, N-dimethylaminopropylacrylamide methyl chloride quaternary salt aqueous solution 621 g were added, and the mixture was stirred at 40 ° C. for 8 hours. The water content of the reaction system at this time was 33% by weight.
Met. The product obtained was purified with 500 g of isopropyl alcohol and then dried to give a white powder (average particle size 4
80 μm) 630 g was obtained. When the degree of cationization of the obtained powder was analyzed by colloid titration, the modification rate was 10 mol% and the reaction rate was 67%. Moreover, the weight average molecular weight was 132,000 as measured by GPC.

Production Example 7 PVA (Kuraray PVA-205) 490 having a saponification degree of 88% and a polymerization degree of 500 was placed in a horizontal blender having a capacity of 4 liters.
g, 50% -NaOH aqueous solution 30 g, and 25% sodium acrylate aqueous solution 1,228 g were added, and the mixture was stirred at 60 ° C. for 8 hours. At this time, the water content of the reaction system was 54% by weight.
50% of 2-acrylamido-2 was added to the product obtained.
-230 g of an aqueous solution of sodium methylpropane sulfonate was added, and the mixture was stirred at 70 ° C for 4 hours. The water content of the reaction system at this time was 53%. The obtained product was purified with 500 g of isopropyl alcohol and then dried to obtain a white powder 72.
0 g (average particle size 800 μm) was obtained. When the obtained product was analyzed by NMR, the carboxy modification rate was 17 mol% and the sulfone group modification rate was 3 mol% (total modification rate of 20%).
%, The reaction rate was 67%. Further, the weight average molecular weight was measured by GPC, and it was 30,000.

Production Example 8 PVA (Kuraray PVA-117) 440 having a polymerization degree of 1,700 when completely saponified was placed in a horizontal blender having a capacity of 4 liters.
g, 30% -NaOH aqueous solution 200 g and 50% -acrylamide aqueous solution 284 g were added, and the mixture was added under N ₂ gas flow at 30%.
Stirred at C for 2 hours. The water content of the reaction system at this time was 31% by weight. Then add 50% -NaOH 50g,
Hydrolysis was performed at 90 ° C. for 3 hours. At this time, the water content of the reaction system was 32%. The product obtained is dried directly,
610 g of white powder (average particle size 760 μm) was obtained. When the obtained powder was analyzed by NMR and IR, the carbamoylethylation degree was 0 mol%, the carboxyethylation degree was 15 mol% (total modification rate was 15 mol%), and the reaction rate was 75%. The weight average molecular weight was 92,000 as measured by GPC.

Production Example 9 PVA (Kuraray PVA-117) 440 having a polymerization degree of 1,700 when completely saponified was placed in a horizontal blender having a capacity of 4 liters.
g, 30% -NaOH aqueous solution 400 g and 50% -acrylic acid aqueous solution 426 g were added, and the mixture was stirred at 20 ° C for 4 hours. The water content of the reaction system at this time was 39% by weight. The obtained product was purified with 500 g of methanol and then dried to obtain 600 g of white powder (average particle size 400 μm). When the obtained powder was analyzed by NMR, the carboxyethylation degree (modification rate) was 19 mol% and the reaction rate was 65%.
Met. Moreover, the weight average molecular weight was 84,000 as measured by GPC.

Production Example 10 PVA (Kuraray PVA-117) 20 having a polymerization degree of 1,700 when completely saponified in a 4-liter separable flask 20
0 g and 1,500 g of water were added, and the temperature was raised to 80 ° C.
The VA was completely dissolved. Then, 20 g of 50% -NaOH aqueous solution and 97 g of acrylamide are added,
For 10 hours. At this time, the water content of the reaction system was 83% by weight. The resulting reaction solution was poured into a large amount of methanol and sheared with a mixer, so that a powder product could be finally obtained. When the obtained powder was analyzed by NMR, the carbamoylethylation degree (modification rate) was 4 mol% and the reaction rate was 13%. The weight average molecular weight by GPC was 84,000.

Production Example 11 PVA (Kuraray PVA-117) 4 having a polymerization degree of 1,700 when completely saponified was placed in a 1-liter separable flask.
4g, 30% -NaOH aqueous solution 40g, 50% -acrylamide aqueous solution 43g, and acetone 500g were added, and
Stirred at C for 4 hours. The obtained product was filtered and dried to obtain 60 g of white powder (average particle size: 510 μm).
When the obtained powder was analyzed by NMR, the carbamoylethylation degree (modification rate) was 21 mol% and the reaction rate was 70%. Moreover, the weight average molecular weight was 82,000 as measured by GPC.

Production Example 12 PVA (Kuraray PVA-124) 4 having a polymerization degree of 2,400 when completely saponified was placed in a 1-liter separable flask.
4 g, 30% -NaOH aqueous solution 20 g, 50% -acrylamide aqueous solution 28 g, and toluene 600 g were added, and 40
Stirred at C for 7 hours. Next, 5 g of 50% -NaOH was added and hydrolysis was performed at 90 ° C. for 1 hour. The obtained product was filtered, purified with a small amount of methanol, and dried to obtain 55 g of white powder (average particle size: 650 μm).
When the obtained powder was analyzed by NMR, the carbamoylethylation degree (modification rate) was 2 mol%, the carboxyethylation degree was 13 mol% (total modification rate was 15 mol%), and the reaction rate was 75%. . Further, the weight average molecular weight was 123,000 as measured by GPC.

Examples 1 to 12 The modified PVA obtained in the above Production Examples 1 to 12 was made into a 5% aqueous solution. At this time, it was possible to rapidly dissolve without heating and dissolving. Prepared by mixing these aqueous solutions with 2% of hydrogenated castor oil as a lubricant, coating on long glass fibers with a roll coater, then bundling this into a yarn and winding it into a winder to produce a glass fiber yarn. did.

The glass fiber produced was examined for film forming properties (fluffing and smoothness).

Next, a glass cloth was prepared from this glass fiber thread, baked at 350 ° C. for 5 hours to remove oil, and the thermal decomposition property was observed from the appearance. The results are shown in Table 1 below.

Comparative Examples 1 and 2 The modified PVA of Examples 1 to 12 was replaced with modified starch (corresponding to Comparative Example 1) and PVA (Kuraray PVA-117) (corresponding to Comparative Example 2), and others were the same as Examples. The same operation was performed. The results are also shown in [Table 1].

For the preparation of the aqueous solution, Examples 1 to 12 were used.
It took more heat and time compared to.

[0055]

[Table 1]

[0056]

The sizing agent of the present invention contains modified PVA as an essential component. Not only can it be dissolved easily (short time) without heating, but it can also be easily dissolved in cold water. The stability of the solution over time is also good.

2. Since the viscosity of the solution is low and there is no spinnability, it is possible to improve workability and prevent excessive adhesion of the sizing agent.

3. It has a good film-forming property, can easily form a film even under high humidity conditions, can prevent the friction between filaments, suppress the occurrence of fluffing, and improve the slip property.

4. Almost completely deoiled at low temperature during thermal decomposition.

5. Since it dissolves easily in water, it can be deoiled with water, steam, etc.

It has many features such as

Therefore, the sizing agent of the present invention exhibits a sizing property with less fluffing and edge breakage when sizing glass fibers and the like, and can be pyrolyzed at a low temperature in a short time even in the oil removing step. Roving cloth and the like can be used for IC substrates, FRPs and the like without deteriorating electrical characteristics and the like.

Claims (4)

[Claims] 1. A weight average molecular weight of 8.0 obtained by subjecting polyvinyl alcohol to a Michael addition reaction with a vinyl compound.
A sizing agent for glass fibers, which comprises a modified polyvinyl alcohol of 00 to 390,000. 2. A sizing agent for glass fibers, which comprises modified polyvinyl alcohol having a weight average molecular weight of 8,000 to 390,000 obtained by subjecting polyvinyl alcohol to a Michael addition reaction of polyvinyl alcohol and then subjecting it to hydrolysis. 3. A weight average molecular weight of 8,000 to 39, which is obtained by subjecting polyvinyl alcohol to a Michael addition reaction with a vinyl compound or is subjected to a hydrolysis treatment thereafter.
A sizing agent for glass fibers, which comprises a modified polyvinyl alcohol powder product obtained by directly drying 10,000 modified polyvinyl alcohol, or purifying with a small amount of an organic solvent and then drying. 4. The sizing agent for glass fibers according to claim 1, wherein the vinyl compound is acrylamide and / or 2-acrylamido-2-methylpropanesulfonic acid or a salt thereof.