JP7057502B2 - Glass chopped strand and method of manufacturing gypsum board using it - Google Patents

Description

The present invention relates to a glass chopped strand that is a source of glass fibers dispersed as a reinforcing material in a core material of gypsum board used for building materials and the like. The present invention also relates to a method for manufacturing gypsum board using the glass chopped strand as the reinforcing material.

Gypsum board is an interior material for buildings that uses gypsum as a core material and covers both sides with base paper for gypsum board. It has features such as fire resistance, sound insulation, dimensional stability, and ease of construction, and is also excellent in economic efficiency. Therefore, it is widely used for the walls and ceilings of buildings. Glass fibers are dispersed in the core material as a reinforcing material, and a glass chopped strand is used as the glass fiber source.

At the time of preparing the core material, the glass chopped strand is kneaded with gypsum and water when preparing the gypsum slurry. Since the glass chopped strand needs to be defibrated during this kneading and the glass fiber needs to be dispersed in the gypsum, the sizing agent used for the glass chopped strand is preferably water-soluble. For example, in Patent Documents 1 and 2, polyethylene oxide is used as a sizing agent for glass chopped strands for gypsum board.

Further, in addition to the above-mentioned sizing agent using polyethylene oxide, as a water-soluble sizing agent, a polyalkylene oxide having a urethane bond and a polyamine-based active agent (polyamine polyamine alkyl amide derivative, etc.), which have different uses from those for gypsum boards, are used. ) (Patent Document 3), polyvinylpyrrolidone and a polyamine-based activator (polyalkylpolyaminealkylamide derivative, etc.) (Patent Document 4), and an amide compound obtained by reacting a polyethylene polyamine with a fatty acid. It is known that an organic acid salt is blended in a sizing agent (Patent Document 5).

Japanese Unexamined Patent Publication No. 8-42111 Japanese Unexamined Patent Publication No. 10-100308 Japanese Patent Application Laid-Open No. 2002-53346 Japanese Patent Application Laid-Open No. 2003-2684 Japanese Unexamined Patent Publication No. 7-33483

As described above, the glass chopped strand for gypsum board must be defibrated during kneading of gypsum and water to disperse the glass fiber in the slurry. Since polyethylene oxide is water-soluble and also has a function as a glue (binder) for bundling glass fibers and glass fibers, it is rational to use it as a blotting agent for the glass chopped strands.

The glass chopped strand for gypsum board is supplied to the slurry via a feeder for a fixed amount supply to the slurry. The feeder includes a tank such as a screw feeder and a rotary feeder, and a rotation mechanism such as a screw and a rotor provided in the tank, and is a glass chopped strand introduced from an introduction port to the tank. Travels in the tank by the rotation mechanism, and is discharged from the distribution port of the tank.

However, if a glass chopped strand focused with polyethylene oxide is introduced into the feeder and the glass chopped strand is discharged from the discharge port of the feeder while advancing in the feeder, the feeder is likely to be clogged. .. This clogging is considered to be due to the fact that the glass chopped strands focused with polyethylene oxide are easily defibrated even in the feeder.

The present invention provides a glass chopped strand for gypsum board, which has improved defibability in gypsum slurry and improved feedability in the feeder.

The present inventor has found that the cause of the defibration of the glass chopped strands in the feeder is the frictional heat between the glass chopped strands as the glass chopped strands filled in the feeder travel in the feeder. I speculated that it might be. Then, he came up with the idea of utilizing a fatty acid amide-based compound known as a thermally stable surfactant as a focusing agent for bundling glass fibers and glass fibers.

Considering compatibility with polyethylene oxide, which has been conventionally used as a sizing agent for glass chopped strands for gypsum board, a polyalkylene polyamine fatty acid condensate having a polyalkylene polyamine unit was conceived as a fatty acid amide-based compound. bottom. As a result of diligent studies by the inventor, a sizing agent containing polyethylene oxide and a polyalkylene polyamine fatty acid condensate led to an improvement in glass chopped strands for gypsum board, leading to the present invention.

That is, the present invention
(1)
A glass chopped strand for gypsum board focused with a sizing agent, wherein the sizing agent is
Polyalkylene polyamine fatty acid condensate (B) and
Containing polyethylene oxide (A),
The ratio of the A and the B is
Expressed based on each mass,
B / A = 0.2-0.8
The glass chopped strand is characterized by the above.

Further, the present invention
(2)
Ignition loss,
0.02 to 0.3% by mass
The glass chopped strand according to (1).

Further, the present invention
(3)
The glass chopped strand according to (1) or (2), which has a water content of 5 to 12% by mass.

Further, the present invention
(4)
It is a method of manufacturing gypsum board, which uses gypsum as a core material and covers and molds both sides with gypsum board base paper.
A gypsum firing step of baking raw gypsum in a firing furnace and crushing it with a crusher to obtain a baked gypsum, and a process of kneading the baked gypsum, glass chopped strands, and water with a mixer to obtain slurry.
A gypsum board molding process in which the slurry is poured between the upper and lower base papers, molded into a plate shape with a molding machine, and then cut after curing.
It is provided with a gypsum board drying step of drying the plate-shaped product in a dryer.
A method for producing gypsum board, which comprises supplying the glass chopped strand according to the above (1), (2), or (3) into a mixer via a screw feeder in the step of obtaining the slurry.

The glass chopped strand of the present invention is not defibrated by a feeder and clogged, and has good defibration in gypsum mud and good dispersibility of glass fibers after defibration. It is possible to provide gypsum board in which glass fibers are uniformly dispersed.

It is a figure which shows the mode in which the glass chopped strand keeps the state of opening and dispersing in the evaluation of dispersibility in water, and shows the aspect which this evaluation is good (◯). It is a figure which shows the aspect in which the glass fiber of a glass chopped strand is partially aggregated in the evaluation of dispersity in water, and shows the aspect which the present invention is possible (Δ). It is a figure which shows the aspect in which the glass fiber of the glass chopped strand is aggregated and settled in the evaluation of dispersibility in water, and shows the aspect which the present invention is impossible (x).

Next, the present invention will be described in detail by showing embodiments, but the present invention is not construed as being limited to these descriptions. The embodiments may be modified in various ways as long as the effects of the present invention are exhibited.

1. 1. Gypsum board and its manufacturing method Gypsum board is usually made by pouring slurry obtained by kneading gypsum and water between the upper and lower base papers, forming it into a plate shape, hardening it, and then roughly cutting it to obtain the product dimensions after drying. Manufactured by cutting. That is, the gypsum board is a gypsum core obtained by a pouring molding method coated with a base paper.

A general gypsum board manufacturing step includes a gypsum baking step, followed by a step of obtaining gypsum, a subsequent step of forming gypsum board, and a subsequent step of drying gypsum board.
The gypsum firing step is a step of baking raw gypsum in a firing furnace, crushing it with a crusher to obtain grilled gypsum, and storing it in a silo.
The step of obtaining the slurry is a step of kneading the mixed material such as gypsum, glass chopped strand, an additive, and water with a mixer to obtain the slurry.
The gypsum board forming step is a step of pouring the slurry between the upper and lower base papers, forming it into a plate shape with a molding machine, curing it, and then cutting it.
The admixture material such as the glass chopped strand is supplied to the mixer via a screw feeder or a rotary feeder. The feeder is a device provided with a screw at the bottom of a hopper for storing glass chopped strands, and the screw is rotated to discharge the glass chopped strands.
The gypsum board drying step is a step of drying the plate-shaped product with a dryer.

In recent years, gypsum board has come to be used for dry-type doorway walls of buildings, and there is a high demand for gypsum board that is effective with nails and screws and has high altitude, out-of-plane bending rigidity and impact resistance.

In order to impart the above-mentioned characteristics, gypsum board having a specific amount of fibers dispersed in a gypsum core is manufactured. Examples of the fiber include organic fiber, inorganic fiber or a mixture thereof, and it is particularly preferable to use organic fiber and inorganic fiber in combination. Examples of the inorganic fiber include mineral fiber such as rock wool, asbestos and sepiolite, glass fiber, carbon fiber and the like. As the organic fiber, various organic fibers can be used, but it is preferable to use pulp fiber, particularly one obtained by beating waste paper. In order to improve the dispersibility of these fibers in the gypsum core, a screw feeder or rotary is used in a kneader such as a mixer that kneads gypsum and water after surface treatment with polyethylene oxide, which is a water-soluble resin. It is better to supply it via a feeder. When the fibers are uniformly dispersed in the slurry, they are uniformly mixed in the hardened gypsum body, and it is considered that the fibers act as a binder for the hardened body.

2. 2. Glass chopped strand A glass chopped strand is a bundle of a large number of glass fibers cut into a predetermined length.

The glass chopped strand of the present invention is a glass chopped strand for reinforcing gypsum board produced from the gypsum slurry described in 1 above, and comprises a polyalkylene polyamine fatty acid condensate (B) and a polyethylene oxide (A). A sizing agent containing the above is applied, and the ratio of the A to the B is B / A = 0.2 to 0.8 in terms of the respective masses.

<Glass fiber, fiberglass bundle and glass chopped strand>
A glass fiber bundle is obtained by pulling out a glass fiber from a bushing provided with tens to thousands of nozzles and applying a sizing agent by a known method. Then, by a known method, one or a plurality of the glass fiber bundles are aligned and cut to a predetermined length to obtain a glass chopped strand.

Examples of the glass fiber include those made of E glass, those made of C glass, those made of S glass, those made of D glass, those made of ECR glass, those made of A glass, those made of AR glass, and the like. .. Among these, the one made of E glass is particularly preferable because it has a composition in which the alkaline component in the glass is small and the elution of alkali is unlikely to occur.

The fiber diameter of the glass fiber is not particularly specified, but can be exemplified by 3 to 20 μm. Considering the manufacturing cost per unit mass of the glass fiber, 3 μm or more is preferable. Further, considering the dispersibility in gypsum slurry and the reinforcing effect of gypsum board, 20 μm or less is preferable. As a more preferable upper limit, 16 μm and 13 μm can be exemplified, and as a more preferable lower limit, 6 μm and 9 μm can be exemplified. These upper and lower limits can be combined arbitrarily.

The number of glass fibers (the number of focused fibers) constituting the glass fiber bundle when cutting the glass fiber bundle to obtain the glass chopped strand is not particularly limited, but is 30,000 to 20,000 in consideration of the ease of handling the glass chopped strand. A book can be exemplified. As a more preferable upper limit, 15,000 and 10,000 can be exemplified, and as a more preferable lower limit, 100 and 100 can be exemplified. These upper and lower limits can be combined arbitrarily.

The fiber length of the glass fiber, that is, the length of the glass chopped strand can be exemplified by 1 to 150 mm in consideration of the ease of handling the glass chopped strand. As a more preferable upper limit, 100 mm and 50 mm can be exemplified, and as a more preferable lower limit, 3 mm and 6 mm can be exemplified. These upper and lower limits can be combined arbitrarily.

<Funding agent>
The sizing agent used for the glass chopped strands of the present invention contains polyethylene oxide (A) and further, a polyalkylene polyamine fatty acid condensate (B).

The polyethylene oxide (A) acts like a glue (binder) that binds a large number of glass fibers to each other.

The polyalkylene polyamine fatty acid condensate (B) is one of the cationic surfactants, and the glass chopped strands play a role of a smoothing agent for reducing defibration due to contact between the glass chopped strands or with a feeder, and polyethylene oxide (polyethylene oxide (B). It is considered that by mixing with A) in a specific ratio, the sizing agent is given an appropriate strength and rapid solubility in a large amount of water.

The polyethylene oxide (A) may be a homopolymer, a copolymer (including a block copolymer), or a terpolymer as long as it is a polymer compound having a-(CH ₂ CH ₂ O) -structure of 80% or more in terms of molar ratio. Well, there are no particular restrictions. The weight average molecular weight of the polyethylene oxide is preferably 1000 or more and 3 million or less. If the weight average molecular weight is less than 1000, sufficient focusing property of glass chopped strands (binding and bundling glass fibers) cannot be obtained. Therefore, it is easy to defibrate with the feeder, and clogging occurs due to defibration with the feeder. When the weight average molecular weight is 3 million or more, polyethylene oxide is difficult to dissolve in water, and when this is used as a sizing agent, the dispersibility of glass fibers in water may decrease. It is preferably 500,000 or less. For example, arcozol GT (manufactured by Meisei Chemical Works, Ltd., active ingredient 10% by mass) can be obtained as containing polyethylene oxide (A) having a weight average molecular weight of less than 500,000.

The polyalkylene polyamine fatty acid condensate (B) used in the present invention is a kind of cationic surfactant. The surface of the glass fiber wet with water tends to be negatively charged, and the cationic group of the cationic surfactant tends to be familiar to the surface of the glass fiber.

The polyalkylene polyamine fatty acid condensate (B) is represented by the general formula _{RCONH (Cn H 2n NH} ) _m A. However, R is an alkyl group or an alkenyl group having 7 to 24 carbon atoms, A is a hydrogen atom or −HNOCR, and m and n are integers of 1 to 5.

After reacting a polyalkylene polyamine with a saturated or unsaturated higher fatty acid having a linear or branched chain to obtain a polyalkylene polyamine higher fatty acid amide, an organic or inorganic acid such as acetic acid, hydrochloric acid, sulfuric acid, or fatty acid is obtained. It can be obtained by neutralizing with. The salt of the polyalkylene polyamine fatty acid condensate is a salt obtained by a neutralization reaction between the polyalkylene polyamine fatty acid condensate and the above-mentioned organic or inorganic acid.

Examples of the polyalkylene polyamine constituting the polyalkylene polyamine fatty acid condensate include diethylenetriamine, triethyleneteramine, tetraethylenepentamine, pentaethylenehexamine, and the like, and among these, more excellent film performance is imparted. Therefore, tetraethylenepentamine and pentaethylenehexamine are preferable. Since these polyalkylene polyamines contain a plurality of amines in one molecule, it is considered that they act as a plurality of cationic groups and are easily adapted to the glass surface.

Examples of fatty acids include behenic acid, stearic acid, palmitic acid, myristic acid, lauric acid, capric acid, isostearic acid, oleic acid, linoleic acid, linoleic acid, erucic acid, etc., and coconut oil, palm oil, beef fat, rapeseed. Examples thereof include fatty acids having a long-chain alkyl composition derived from natural fats and oils such as oil and fish oil. Of these, stearic acid and palmitic acid are preferable in order to impart better film performance.

The number of moles of the fatty acid to be reacted with 1 mol of the polyalkylene polyamine is preferably 0.2 to 1.8 mol, more preferably 1.0 to 1.5 mol. If the number of moles of fatty acid is less than 0.2 mol, the film performance is not sufficient, and if it is more than 1.8 mol, the solubility in water is lowered and sufficient performance cannot be exhibited.

In order to introduce a long-chain alkyl group, a long-chain alkenyl group, etc. as a hydrophobic group into the polyalkylpolyamine which is a group of a hydrophilic group, the fatty acid is linked by an amide bond having good heat resistance and stability.

Examples of the organic acid and the inorganic acid used for neutralizing the polyalkylene polyamine fatty acid condensate include the following.

Examples of the organic acid include carboxylic acid, sulfonic acid, organic phosphoric acid and the like. i) Carous acid: Saturated monocarboxylic acid (acetic acid, propionic acid, capric acid, lauric acid, stearic acid, behenic acid, etc.) which is a monocarboxylic acid having 1 to 24 carbon atoms, unsaturated monocarboxylic acid (acrylic acid, etc.) Methacrylic acid, oleic acid, etc.), aliphatic oxycarboxylic acid (glycolic acid, lactic acid, gluconic acid, etc.), aliphatic polycarboxylic acid (succinic acid, succinic acid, adipic acid, azelaic acid, sebatic acid, maleic acid, fumaric acid, etc.) , Itaconic acid, etc.), Aromatic carboxylic acids (phthalic acid, trimellitic acid, pyromellitic acid, etc.); Lauryl sulfonic acid, etc.), aromatic sulfonic acid (toluene sulfonic acid, naphthalin sulfonic acid, etc.), etc .; iii) Organic phosphoric acid: aliphatic alkyl phosphate having 1 to 24 carbon atoms, aliphatic alkyl phosphine having 1 to 24 carbon atoms. Acids, aliphatic alkylphosphonic acids having 1 to 24 carbon atoms, etc .; and the like.

Examples of the inorganic acid include hydrofluoric acid, hydrochloric acid, bromic acid, iodoic acid, sulfuric acid, nitric acid, phosphoric acid, carbonic acid, boric acid and the like.

Of these, organic acids are preferred because they reduce product viscosity and improve handleability. Of the organic acids, carboxylic acid is preferable, monocarboxylic acid is more preferable, and acetic acid and propionic acid are particularly preferable. The pH of the neutralized salt (25 ° C., 3% aqueous solution) is preferably 3 to 10. If the pH is lower than 3, the properties become unstable, and if the pH is higher than 10, sufficient film performance cannot be obtained, which is not preferable.

Specific examples of the polyalkylene polyamine fatty acid condensate (B) according to the present invention include pentaethylene hexamine stearate / acetate, pentaethylene hexamine laurate / propionate, and tetraethylene pentamine stearate. Examples include acetates, tetraethylenepentamine stearate condensates / sulfates, diethylenetriamine laurate condensates / phosphates, and the like.

Examples of those containing those belonging to the polyalkylene polyamine fatty acid condensate (B) include Softon GW-18 (manufactured by Toho Chemical Industry Co., Ltd., active ingredient 30% by mass). As other components, a silane coupling agent, an antistatic agent, a smoothing agent and the like may be appropriately contained.

The glass chopped strand of the present invention is coated with a sizing agent containing polyethylene oxide (A) and a polyalkylene polyamine fatty acid condensate (B).

The ratio of the A to the B is preferably B / A = 0.2 to 0.8 in terms of the respective masses. The glass chopped strands coated with the sizing agent outside this range are easily defibrated by the feeder, which causes a lot of fluffing, and the discharge amount of the glass chopped strands from the feeder fluctuates and becomes unstable. More preferably, it is 0.22 to 0.76.

Considering that the surface of the glass fiber wet with water tends to be negatively charged, it is considered that the cationic surfactant is more compatible with the glass fiber than the nonionic surfactant and the anionic surfactant. Furthermore, it is considered that those containing a plurality of cation groups are more compatible with glass fibers than those containing only one cation group in one molecule.

Then, it is considered that the polyalkylene polyamine fatty acid condensate (B) is easily compatible with the surface of the glass fiber due to the action of a plurality of cation groups derived from the amine contained in one molecule.

When the polyalkylene polyamine fatty acid condensate (B) and the polyethylene oxide (A) are used as a sizing agent at the ratio of B / A, the frictional heat between the glass chopped strands as they travel through the feeder causes the glass chopped strands. The glass chopped strand of the present invention is difficult to deflate in a feeder and is used in water to obtain a film that gives continuous wear resistance resulting from the heat resistance of B and a large amount of quick solubility in water. It is considered that both defibration and ease of dispersion can be achieved.

The ignition loss is preferably 0.02 to 0.3% by mass. If it is less than 0.02% by mass, the glass chopped strand has a lot of fluffing in the feeder, and the discharge amount of the glass chopped strand from the feeder fluctuates and becomes unstable. If it is larger than 0.3% by mass, the dispersibility of the glass chopped strand in water becomes poor. More preferably, it is 0.05 to 0.25% by mass.

Adjustment of ignition loss can be performed by a known method. For example, when pulling out glass fiber from a bushing and applying a sizing agent to obtain a glass fiber bundle. The sizing agent is applied by the applicator. By appropriately adjusting the roller rotation speed of the applicator, the amount of the sizing agent applied to the glass fiber is adjusted, and as a result, the ignition loss is adjusted. In line with this, further, by adjusting the concentration of the active ingredient of the sizing agent, fine adjustment of ignition loss can be performed.

The water content is preferably 5 to 12% by mass. If it is less than 5% by mass, the glass chopped strand becomes slippery and difficult to handle. If it exceeds 12% by mass, the glass chopped strands tend to adhere to each other, which makes it difficult to handle. More preferably, it is 5 to 10% by mass.

Moisture content and ignition loss of glass chopped strands are determined according to JIS R 3420 (2006) 7.3.

In addition to the above-mentioned polyethylene oxide (A) as a component of the sizing agent of the present invention, and further, polyvinyl alcohol and polyvinyl which are water-soluble resins as long as the effects of the present invention are not impaired, in addition to the polyalkylene polyamine fatty acid condensate (B). It may contain pyrrolidone and the like.

Hereinafter, the present invention will be specifically described with reference to Examples. However, the present invention is not limited to such examples.

Table 1 summarizes Examples 1 to 10 and Table 2 summarizes the sizing agent composition of Comparative Examples 1 to 9, the characteristics of the glass chopped strand (ignition loss, moisture content), and the evaluation results thereof.

<Preparation of sizing agent>
[Examples 1 to 8]
Polyethylene oxide (A), polyalkylene polyamine fatty acid condensate (B), and water were mixed to obtain a sizing agent having an active ingredient ratio (% by mass) of each component shown in Table 1. Here, the active ingredient ratio (mass%) is a numerical value expressing the ratio of the mass of the active ingredient as a percentage based on the mass of the sizing agent.

Specifically, an aqueous solution of polyethylene oxide (manufactured by Meisei Chemical Industry Co., Ltd., trade name Arcozol GT, active ingredient 10% by mass), a polyalkylene polyamine fatty acid condensate, and a mixture of its acetate and water (Toho Chemical Industry Co., Ltd., product). In Example 1, 37.5 parts by mass and 2.5 parts by mass, and in Example 2, 37.5 parts by mass and 3.0 parts by mass, with the name Sofnon GW18, active ingredient 30% by mass). In Example 3, 42.5 parts by mass and 3.4 parts by mass, in Example 4, 42.5 parts by mass and 6.8 parts by mass, and in Example 5, 42.5 parts by mass and 10.2 parts. By mass, 42.5 parts by mass and 11.1 parts by mass in Example 6, 21.0 parts by mass and 1.7 parts by mass in Example 7, and 85.0 parts by mass in Example 8. , 20.0 parts by mass were added, water was added to each to make 1000 parts by mass as a whole, and the mixture was stirred at room temperature for 20 minutes to obtain a sizing agent. Using these sizing agents, each glass chopped strand was obtained according to the method for producing a glass chopped strand shown below, and the evaluation shown below was performed.

[Example 9]
Polyethylene oxide (A), polyalkylene polyamine fatty acid condensate (B), partially saponified polyvinyl alcohol, and water are mixed to obtain a sizing agent having an active ingredient ratio (% by mass) of each component shown in Table 1. Obtained. Here, the active ingredient ratio (mass%) is a numerical value expressing the ratio of the mass of the active ingredient as a percentage based on the mass of the sizing agent.

Specifically, an aqueous solution of polyethylene oxide (manufactured by Meisei Chemical Works, Ltd., trade name: Arcozol GT, active ingredient 10% by mass), a polyalkylene polyamine fatty acid condensate, and a mixture of its acetate and water (Toho Chemical Works, Ltd., Commodity) Name Sofnon GW18, active ingredient 30% by mass) and partially saponified polyvinyl alcohol (Taiseikayaku Co., Ltd., trade name A-520G, active ingredient 25% by mass), 37.5 parts by mass and 6. 8 parts by mass and 2.0 parts by mass were added, water was added to prepare a total of 1000 parts by mass, and the mixture was stirred at room temperature for 20 minutes to obtain a sizing agent. Using this sizing agent, glass chopped strands were obtained according to the method for producing glass chopped strands shown below, and the evaluations shown below were performed.

[Example 10]
Polyethylene oxide (A), polyalkylene polyamine fatty acid condensate (B), stearyldimethyl, hydroxyethyl, ammonium, paratoluenesulnate, and water are mixed, and the active ingredient ratio (mass) of each component shown in Table 1 is obtained. %) Obtained a sizing agent. Here, the active ingredient ratio (mass%) is a numerical value expressing the ratio of the mass of the active ingredient as a percentage based on the mass of the sizing agent. Specifically, an aqueous solution of polyethylene oxide (manufactured by Meisei Chemical Works, Ltd., trade name: Arcozol GT, active ingredient 10% by mass), a polyalkylene polyamine fatty acid condensate, and a mixture of its acetate and water (Toho Chemical Works, Ltd., Commodity) Name Sofnon GW18, active ingredient 30% by mass) and an aqueous solution of stearyldimethyl, hydroxyethyl, ammonium, paratoluene sulnate (manufactured by Daiichi Seiyaku Kogyo Co., Ltd., trade name: Catiogen D2, active ingredient 60% by mass), respectively. , 37.5 parts by mass, 3.0 parts by mass, and 0.7 parts by mass were added, water was added to prepare a total of 1000 parts by mass, and the mixture was stirred at room temperature for 20 minutes to obtain a sizing agent. .. Using this sizing agent, glass chopped strands were obtained according to the method for producing glass chopped strands shown below, and the evaluations shown below were performed.

[Comparative Example 1]
A focusing agent having the composition shown in Table 2 was prepared.

Specifically, add water to 37.5 parts by mass of an aqueous solution of polyethylene oxide (manufactured by Meisei Chemical Works, Ltd., trade name: Arcozol GT, 10% by mass of active ingredient) to make a total of 1000 parts by mass at room temperature. Stirring for 20 minutes gave a sizing agent. Using this sizing agent, glass chopped strands were obtained according to the method for producing glass chopped strands shown below, and the evaluations shown below were performed.

[Comparative Examples 2 and 3]
A focusing agent having the composition shown in Table 2 was prepared.

Specifically, an aqueous solution of polyethylene oxide (manufactured by Meisei Chemical Works, Ltd., trade name: Arcozol GT, active ingredient 10% by mass), a polyalkylene polyamine fatty acid condensate, and a mixture of its acetate and water (Toho Chemical Works, Ltd., Commodity) In Comparative Example 2, 37.5 parts by mass and 1.3 parts by mass, and in Comparative Example 3, 42.5 parts by mass and 12.0 parts by mass, were added. Then, water was added to prepare each to make 1000 parts by mass as a whole, and the mixture was stirred at room temperature for 20 minutes to obtain a sizing agent. Using these sizing agents, each glass chopped strand was obtained according to the method for producing a glass chopped strand shown below, and the evaluation shown below was performed.

[Comparative Example 4]
A focusing agent having the composition shown in Table 2 was prepared.
Specifically, 31.3 parts by mass of an aqueous solution of completely saponified polyvinyl alcohol (manufactured by Taisei Kayaku Co., Ltd., trade name: Polyace NM14, active ingredient 12% by mass), a polyalkylene polyamine fatty acid condensate, its acetate and water. Add water to 3.0 parts by mass of the mixture (Toho Chemical Industry Co., Ltd., trade name Sofnon GW18, active ingredient 30% by mass) to make 1000 parts by mass, and stir at room temperature for 20 minutes to make a sizing agent. Got Using this sizing agent, glass chopped strands were obtained according to the method for producing glass chopped strands shown below, and the evaluations shown below were performed.

[Comparative Example 5]
A focusing agent having the composition shown in Table 2 was prepared.
Specifically, 15.0 parts by mass of an aqueous solution of partially saponified polyvinyl alcohol (manufactured by Taisei Kayaku Co., Ltd., trade name A-520G, active ingredient 25% by mass), a polyalkylene polyamine fatty acid condensate, its acetate and water. (Toho Chemical Industry Co., Ltd., trade name: Softon GW18, active ingredient 30% by mass) Add water to 3.0 parts by mass, prepare to make 1000 parts by mass as a whole, and stir at room temperature for 20 minutes to focus. I got the agent. Using this sizing agent, glass chopped strands were obtained according to the method for producing glass chopped strands shown below, and the evaluations shown below were performed.

[Comparative Example 6]
A focusing agent having the composition shown in Table 2 was prepared.
Specifically, 37.5 parts by mass of an aqueous solution of polyethylene oxide (manufactured by Meisei Chemical Works, Ltd., trade name: Arcozol GT, 10% by mass of active ingredient) and an aqueous solution of stearyldimethyl, hydroxyethyl, ammonium, and paratoluene sulnate (first). Industrial Pharmaceutical Co., Ltd., trade name: Catiogen D2, active ingredient 60% by mass) 0.7 parts by mass and aqueous solution of polyoxyethylene sorbitan monooleate (manufactured by Kao Co., Ltd., trade name: Leodor TW-0106V, active ingredient 100% by mass) %) 0.9% by mass, water was added to prepare the mixture so that the total amount was 1000 parts by mass, and the mixture was stirred at room temperature for 20 minutes to obtain a sizing agent. Using this sizing agent, glass chopped strands were obtained according to the method for producing glass chopped strands shown below, and the evaluations shown below were performed.

[Comparative Example 7]
A focusing agent having the composition shown in Table 2 was prepared.
Specifically, 31.3 parts by mass of a completely saponified polyvinyl alcohol aqueous solution (manufactured by Taisei Yakuhin Co., Ltd., trade name: Polyace NM14, active ingredient 12% by mass) and stearyldimethyl, hydroxyethyl, ammonium, and paratoluene sulnate. 0.7 parts by mass of an aqueous solution (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Catiogen D2, active ingredient 60% by mass) and an aqueous solution of polyoxyethylene sorbitan monooleate (manufactured by Kao Co., Ltd., trade name: Leodor TW-0106V, Water was added to 100% by mass of the active ingredient) to 0.9% by mass, and the mixture was adjusted to 1000 parts by mass as a whole and stirred at room temperature for 20 minutes to obtain a sizing agent. Using this sizing agent, glass chopped strands were obtained according to the method for producing glass chopped strands shown below, and the evaluations shown below were performed.

[Comparative Example 8]
A focusing agent having the composition shown in Table 2 was prepared.
Specifically, 15.0 parts by mass of an aqueous solution of partially saponified polyvinyl alcohol (manufactured by Taisei Kayaku Co., Ltd., trade name A-520G, active ingredient 25% by mass) and stearyldimethyl, hydroxyethyl, ammonium, and paratoluene sulnate. (Manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Catiogen D2, active ingredient 60% by mass) 0.7 parts by mass and an aqueous solution of polyoxyethylene sorbitan monooleate (manufactured by Kao Co., Ltd., trade name: Leodor TW-0106V) , Active ingredient 100% by mass) 0.9% by mass, water was added to make 1000 parts by mass as a whole, and the mixture was stirred at room temperature for 20 minutes to obtain a sizing agent. Using this sizing agent, glass chopped strands were obtained according to the method for producing glass chopped strands shown below, and the evaluations shown below were performed.

<Making glass chopped strands>
800 glass fibers having a fiber diameter of 13 μm are pulled out from a bushing having 800 nozzles, and the glass fiber bundle in which 800 glass fibers are bundled is wound while applying the sizing agent prepared in the above procedure, and each sizing agent is wound. I got 3 cakes. Here, the cake is a wound glass fiber bundle.

Next, for each sizing agent, glass fiber bundles were pulled out from the three cakes, and the three glass fiber bundles were bundled while applying water, and cut to a length of 3 mm with a cutting machine. The moisture content and ignition loss of the obtained glass chopped strands are shown in Tables 1 and 2.

The glass chopped strands obtained here were subjected to the above-mentioned feedability evaluation and water dispersity evaluation, and the results are shown in Tables 1 and 2.
The glass chopped strands obtained above were evaluated by the methods shown below.

<Moisture rate, loss on ignition>
Moisture content and ignition loss of glass chopped strands were measured according to JIS R 3420 (2006) 7.3.

<Feedability evaluation>
A 500 g glass chopped strand was put into a screw feeder (manufactured by Kuma Engineering Co., Ltd., model name Accurate Feeder), and the screw feeder was operated at a rotation speed of 2 times / minute for 180 minutes.

From the relationship between the operating time of the screw feeder and the discharge amount of the glass chopped strand at this time, the ease of discharge (feedability) was evaluated in the following three stages. As for the feedability, the screw feeder having a larger degree of defibration of the glass chopped strand is more likely to be clogged.

The lower the rotation speed of the screw feeder, the more the chopped strands rub against each other. As a result, it is easy to express whether the degree of fluff generation that hinders the slipperiness at the time of putting into the screw and the feedability in the screw is good or bad. This condition is used because the difference is erased when the rotation speed is set to high speed.

Good (〇): 500 g of glass chopped strands could be discharged in less than 150 minutes without clogging.
Possible (Δ): 500 g of glass chopped strands could be discharged in 150 to 180 minutes without clogging.
Impossible (x): The feeder was clogged in the middle and ejection became impossible.

<Evaluation of dispersibility in water>
Put 5 g of glass chopped strands into a beaker with a capacity of 200 ml, stir with a glass rod at a rate of 20 times / minute for 1 minute, and then visually observe the mode of defibration and dispersion of the glass fibers after 10 minutes. It was evaluated in the following three stages.

Good (〇): The glass chopped strand keeps the fiber open and dispersed state (aspect shown in FIG. 1).
Possible (Δ): The glass fibers of the glass chopped strand are partially aggregated (aspect shown in FIG. 2).
Impossible (x): Glass fibers of glass chopped strands are aggregated and settled (aspect shown in FIG. 3).

As shown in Tables 1 and 2, the following was found from Examples 1 to 10 and Comparative Examples 1 to 7.
The composition of the sizing agent contains polyethylene oxide (A) and a polyalkylene polyamine fatty acid condensate (B), and the ratio of the A to the B is expressed with reference to the respective masses, and B / A = 0. In Examples 1 to 10 satisfying .2 to 0.8, the glass chopped strand can be discharged from the screw feeder without being clogged in the middle, and the feedability is good, and the dispersibility in water is also good. Met.
On the other hand, Comparative Examples 1 to 3 and Comparative Example 6 which did not satisfy B / A = 0.2 to 0.8 did not satisfy both the feedability and the dispersibility in water.
Comparative Examples 4, 5, 7, and 8 in which polyvinyl alcohol was used instead of polyethylene oxide (A) also did not satisfy both feedability and dispersibility in water.

Claims (4)

A glass chopped strand for gypsum board focused with a sizing agent, wherein the sizing agent is
With polyethylene oxide (A),
Containing polyalkylene polyamine fatty acid condensate (B),
The ratio of the A and the B is
Expressed based on each mass,
B / A = 0.2-0.8
The glass chopped strand, characterized in that it is. Ignition loss,
0.02 to 0.3% by mass
The glass chopped strand for gypsum board according to claim 1. The glass chopped strand for gypsum board according to claim 1 or 2, wherein the water content is 5 to 12% by mass. It is a method of manufacturing gypsum board, which uses gypsum as a core material and covers and molds both sides with gypsum board base paper.
A gypsum firing step for preparing gypsum and a step of kneading a mixture containing the gypsum, glass chopped strands, and water with a mixer to obtain a slurry.
A gypsum board molding process in which the slurry is poured between the upper and lower base papers, molded into a plate shape with a molding machine, and then cut after curing.
The gypsum board drying step of drying the plate-shaped product is provided.
A method for producing gypsum board, which comprises supplying the glass chopped strand according to any one of claims 1 to 3 into a mixer in the step of obtaining the slurry.

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