JP3532329B2 - Polyester fiber for paper - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyester fiber for paper, a paper using the polyester fiber and a dispersant for the polyester fiber for paper. More specifically, the present invention has good dispersibility when producing polyester fiber paper or a mixed paper of polyester fiber and other fibers by papermaking, and therefore has excellent uniformity, good texture and paper strength. The present invention relates to a polyester fiber for paper, which is capable of obtaining paper having the above, a paper obtained by using the polyester fiber, and a dispersant for the polyester fiber for paper.

[0002]

2. Description of the Related Art Vinylon, polypropylene-based fibers, and polyacrylonitrile-based fibers have been widely used for the production of synthetic fiber papers in recent years. At the same time, cost reduction is also required. Therefore, among the synthetic fiber papers, various attempts have been made to develop a polyester fiber paper which has a unique soft texture, is excellent in dimensional stability when wet, and is low in cost.

In the production of polyester fiber paper by papermaking, good water dispersibility of the polyester fiber prevents the dispersion of the fiber and generation of lumps due to agglomeration, resulting in excellent uniformity and good texture. Moreover, it is an important requirement for obtaining strong and strong paper. Water-soluble polyurethane, polyoxyethylene alkyl ether, or a mixture thereof has been used as a dispersant for polyester fibers for papermaking, but any of them must impart sufficiently good dispersibility to the fiber. Could not be obtained, and polyester fiber paper having excellent strength could not be obtained.

In addition to the above, a polyester / polyether block composed of a polyester block composed of terephthalic acid and / or isophthalic acid and a lower alkylene glycol and a polyether block composed of polyalkylene glycol and / or its monoether is used. A method of adhering a polymer to polyester fibers for papermaking to improve the water dispersibility of the fibers (JP-A-58-2084).
99 and JP-A-58-208500),
Paper making a copolyester obtained by copolymerizing a polyester mainly composed of a terephthalic acid unit and / or an isophthalic acid unit and a lower alkylene glycol unit with an ester-forming alkali metal sulfonate unit (for example, a sodium 5-sulfoisophthalate unit) A method of adhering to polyester fiber for use to improve water dispersibility of the fiber (Japanese Patent Publication No. 3-33837) and the like have been proposed.

When the polyester block / polyether block copolymer is used, or when the above-mentioned conventional method using the copolyester is used, the polyester fiber has a fiber length of less than 10 mm or a large fineness. The dispersibility of the fibers can be improved to some extent, and thereby the strength and texture of the paper can be improved to some extent. However, when the fiber length of the polyester fiber is as long as 10 mm or more and the fineness is 0.5 denier or less, the water dispersibility of the fiber becomes poor, and a polyester fiber paper excellent in uniformity, texture and strength cannot be obtained. .

[0006] Further, for the purpose of dispersing polyester fibers having a large aspect ratio to make paper, a surfactant having a high foaming property is mixed with the fiber slurry, and the mixture is vigorously stirred to be foamed. A method of making a paper and then defoaming it with an antifoaming agent has been proposed (JP-A-4-35).
2897). However, in the case of this method, a foaming step and a subsequent defoaming step are required, which complicates the process and makes it difficult to manage the process,
Moreover, there is a drawback when the productivity becomes low.

[0007]

The object of the present invention is to obtain a high-quality polyester fiber paper or a mixed paper of polyester fiber and other fibers, which is excellent in properties such as uniformity, texture (texture), and paper strength. It is to provide a polyester fiber for paper which is excellent in water dispersibility. The object of the present invention is to produce polyester fiber paper or a mixed paper of polyester fiber and other fibers having the above-mentioned excellent properties in a simple process and with good productivity regardless of the aspect ratio of the polyester fiber. A polyester fiber for paper, which has good water dispersibility and does not cause foaming, and a dispersant therefor. Further, an object of the present invention is to provide a polyester fiber paper and a mixed paper of polyester fiber and other fibers, which are excellent in properties such as uniformity, texture (texture) and paper strength.

[0008]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present inventors have made repeated studies from various points. As a result, a specific molecular weight of polyoxyalkylene fatty acid amide, a specific molecular weight of polyoxyalkylene triglyceride, a specific molecular weight of polyoxyalkylene styrenated phenyl ether and a specific molecular weight of polycarboxylic acid salt in a specific ratio. Forming a dispersant containing it, and attaching the dispersant to polyester fiber, polyester fiber for paper with extremely excellent water dispersibility can be obtained, and when paper is produced by papermaking using the polyester fiber, uniformity It has been found that a polyester fiber paper or a mixed paper of polyester fiber and other fibers excellent in texture such as texture and paper strength can be obtained. Furthermore, the present inventors have found that when the above-mentioned dispersant is used, foaming does not occur in the aqueous papermaking slurry in which polyester fibers are dispersed, and therefore the dispersion of fibers is performed without defoaming the slurry. It was found that a paper having a good appearance and excellent in properties such as uniformity and texture, which is free from defects and lumps due to nodulation, can be obtained, and the present invention was completed based on these findings.

That is, the present invention provides (A) a molecular weight of 300.
~ 4000 polyoxyalkylene fatty acid amides,
(B) a polyoxyalkylene triglyceride having a molecular weight of 700 to 8000, (C) a polyoxyalkylene styrenated phenyl ether having a molecular weight of 500 to 6000, and (D) a polycarboxylic acid salt having a molecular weight of 1000 to 15000 are represented by the following formulas;

[0010]

## EQU3 ## {a / (a + b + c)} × 100 = 10 to 30 (wt%) {b / (a + b + c)} × 100 = 20 to 80 (wt%) {c / (a + b + c)} × 100 = 10 50 (% by weight) a: c = 1: 0.2 to 1: 3 (a + b + c): d = 20: 80 to 80:20 (wherein, a = weight of polyoxyalkylene fatty acid amide b = polyoxyalkylene triglyceride) Of the polyoxyalkylene styrenated phenyl ether (d = weight of the polycarboxylic acid salt) is attached to the polyester fiber for paper. Then, the present invention includes a paper obtained by using the polyester fiber for paper, and the paper here includes both a polyester fiber paper and a mixed paper of polyester fiber and other fibers.

The present invention also provides (A) a molecular weight of 300 to
4000 polyoxyalkylene fatty acid amide [hereinafter this may be referred to as "component (A)"], (B) polyoxyalkylene triglyceride having a molecular weight of 700 to 8000 [hereinafter may be referred to as "component (B)"] ,
(C) Polyoxyalkylene styrenated phenyl ether having a molecular weight of 500 to 6000 [hereinafter referred to as "component (C)" and (D) a polycarboxylic acid salt having a molecular weight of 1000 to 15000 [hereinafter referred to as "component (D)" There is the following formula ~;

[0012]

## EQU00004 ## {a / (a + b + c)} × 100 = 10 to 30 (wt%) {b / (a + b + c)} × 100 = 20 to 80 (wt%) {c / (a + b + c)} × 100 = 10 50 (wt%) a: c = 1: 0.2 to 1: 3 (a + b + c): d = 20: 80 to 80:20 [wherein, a = weight of component (A), b = component (B). And c = weight of component (C) and d = weight of component (D)] in a proportion satisfying the above conditions.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. As described above, the dispersant for polyester fibers of the present invention is required to contain four components (A) to (D). Among these components, the component (A) and the component (B) have a function of making the surface of the polyester fiber hydrophilic and improving the water dispersibility of the polyester fiber, and the component (C) and the component (D). ) Makes the polyester fiber hydrophilic and, at the same time, increases the friction coefficient between the polyester fiber and the polyester fiber, and when other fibers are used together, increases the friction coefficient between the polyester fiber and the other fiber to increase the paper strength. Has a function of improving.

The polyoxyalkylene fatty acid amide used as the component (A) in the dispersant of the present invention has a alkanol group bonded to the nitrogen atom of the fatty acid amide obtained by the reaction of a fatty acid and an amine or an alkanol group bonded to the nitrogen atom. It is a fatty acid amide ether in which a polyoxyalkylene group (polyalkylene oxide group) is bonded to a hydroxyl group.

Preferable examples of the above-mentioned fatty acids used in the production of the component (A) include saturated fatty acids and unsaturated fatty acids having 8 to 22 carbon atoms, and these fatty acids may be used alone or in combination of two or more kinds. May be used. Further, examples of the above-mentioned amine used for the production of the component (A) include monoalkylamines (methylamine, ethylamine, propylamine, butylamine, pentylamine,
Alkylamines such as heptylamine, octylamine, etc., monoarylamines (aniline, etc.), monoaralkylamines (benzylamine, etc.), monoalkanolamines (monoethanolamine, monopropanolamine, monobutanolamine, etc.), dialkanols. Examples include amines (diethanolamine, dipropanolamine, dibutanolamine, etc.), alkylenediamines (ethylenediamine, propylenediamine, etc.), dialkylenetriamines (diethylenetriamine, etc.), trialkylenetetramines (triethylenetetramine, etc.), and these amines are They may be used alone or in combination of two or more. Among them,
It is preferable to use triethylenetetramine or stearylamine as the amine.

Further, as the polyalkylene oxide group (polyoxyalkylene group) in the component (A),
Examples thereof include a polypropylene oxide group, a polyethylene oxide group, a propylene oxide / ethylene oxide random copolymer group, and a block copolymer group consisting of a polypropylene oxide block / polyethylene oxide block. Among them, polypropylene oxide block / polyethylene oxide block Is preferably a block copolymer group consisting of In the component (A) used in the present invention, an alkylene oxide group (usually an ethylene oxide group and / or a propylene oxide group) is usually bonded in an amount of about 5 to 30 mol.

The polyoxyalkylene fatty acid amide used as the component (A) has a molecular weight of 300 to 400.
It is necessary to be 0, preferably 600 to 1500, and more preferably around 1000. When the molecular weight of the component (A) deviates from the above-mentioned range of 300 to 4000, the surface of the polyester fiber cannot be made sufficiently hydrophilic, the water dispersibility of the polyester fiber becomes poor, and the polyester fiber is not processed. At times, foaming becomes large and it becomes impossible to obtain a uniform dispersion.In the obtained polyester fiber paper or mixed paper of polyester fiber and other fibers, many particles due to poor dispersion of fibers and agglomeration occur, The appearance, texture, and strength are poor.

The polyoxyalkylene triglyceride used as the component (B) in the present invention is a polyoxyalkylene group (polyalkylene oxide) with respect to a hydroxyl group of a triglyceride having a hydroxyl group such as castor oil, rapeseed oil and soybean oil. It is a triglyceride ether having a group bonded thereto. As the polyalkylene oxide group (polyoxyalkylene group) in the component (B), a polypropylene oxide group, a polyethylene oxide group, a propylene oxide / ethylene oxide random copolymer group, a block copolymer composed of a polypropylene oxide block / polyethylene oxide block. Examples thereof include groups, and among them, a block copolymer group composed of polypropylene oxide block / polyethylene oxide block is preferable. In the component (B) used in the present invention, an alkylene oxide group (usually an ethylene oxide group and / or a propylene oxide group) is usually bonded in an amount of about 10 to 70 mol.

The polyoxyalkylene triglyceride used as the component (B) has a molecular weight of 700-80.
It is necessary to be 00, preferably 1500 to 4000, and more preferably around 2000.
When the molecular weight of the component (B) is less than 700, the surface of the polyester fiber cannot be made sufficiently hydrophilic and the water dispersibility of the polyester fiber becomes poor, resulting in excellent uniformity, texture and strength. Is not obtained, and the fiber friction coefficient tends to decrease. On the other hand, when the molecular weight of the component (B) exceeds 8,000, dispersibility in the dispersant is lowered.

Further, the polyoxyalkylene styrenated phenyl ether used as the component (C) in the present invention is a polyoxyalkylene group (polyalkylene group) with respect to a phenyl group having one, two or three styryl groups bonded. (Oxide group) is a styrenated phenyl ether having an ether bond. In component (C),
The polyalkylene oxide group (polyoxyalkylene group) ether-bonded to the phenyl group is composed of a polypropylene oxide group, a polyethylene oxide group, a propylene oxide / ethylene oxide random copolymer group, a polypropylene oxide block / polyethylene oxide block. Examples thereof include a block copolymer group, and among them, a block copolymer group composed of polypropylene oxide block / polyethylene oxide block is preferable. In the component (D) used in the present invention, an alkylene oxide group (usually an ethylene oxide group and / or a propylene oxide group) is usually bonded in an amount of about 10 to 70 mol.

The polyoxyalkylene styrenated phenyl ether used as the component (C) must have a molecular weight of 500 to 6000.
It is preferably ˜3000, more preferably around 1500. When the molecular weight of the component (C) is less than 500, the surface of the polyester fiber cannot be made sufficiently hydrophilic, the water dispersibility of the polyester fiber becomes poor, and the friction coefficient between the fibers can be increased. Not possible, uniformity,
Paper with excellent texture and strength cannot be obtained. On the other hand, when the molecular weight of the component (C) exceeds 6000, the defoaming effect on the surface of the dispersant decreases.

The polycarboxylic acid salt used as the component (D) in the present invention is an unsaturated monocarboxylic acid such as acrylic acid, methacrylic acid, crotonic acid, oleic acid; maleic acid, fumaric acid, citraconic acid, mesaconic acid. One or two of unsaturated dicarboxylic acids or their anhydrides such as
The carboxyl group of the polycarboxylic acid obtained by polymerizing the above is converted into a salt of an alkali metal such as sodium, potassium and lithium, or a salt of an alkaline earth metal such as calcium and magnesium. Among them, the potassium salt and sodium salt of the above-mentioned polycarboxylic acid are preferably used as the component (D).

The polycarboxylic acid salt used as the component (D) is required to have a molecular weight of 1,000 to 15,000, preferably 2,000 to 10,000, and more preferably about 5,000. Ingredient (D)
If the molecular weight of is out of the above-mentioned range of 1000 to 15000, the surface of the polyester fiber cannot be made sufficiently hydrophilic, the water dispersibility of the polyester fiber becomes poor, and the foaming during the papermaking of the polyester fiber becomes large. As a result, it becomes impossible to obtain a uniform dispersion, resulting in poor dispersion of fibers and lumps due to agglomeration, resulting in poor texture, uniformity and strength of the paper.

In the dispersant used in the present invention, the content ratios of the components (A) to (D) in the dispersant are represented by the following formulas;

[0025]

## EQU00005 ## {a / (a + b + c)} × 100 = 10 to 30 (wt%) {b / (a + b + c)} × 100 = 20 to 80 (wt%) {c / (a + b + c)} × 100 = 10 50 (wt%) a: c = 1: 0.2 to 1: 3 (a + b + c): d = 20: 80 to 80:20 [wherein, a = weight of component (A), b = component (B). , C = weight of component (C) and d = weight of component (D)].

When the content ratio of the components (A) to (D) is out of the range of the above formulas, the water dispersibility of the polyester fiber becomes poor, and the foaming of the papermaking raw material containing the polyester fiber becomes large. , Uniformity, texture,
Polyester fiber paper with excellent properties such as paper strength cannot be obtained. Water dispersibility of polyester fiber, prevention of foaming,
From the viewpoint of quality of the obtained polyester fiber paper and mixed paper,
Based on the total weight of the component (A), the component (B) and the component (C), the weight (a) of the component (A) is about 20% by weight,
The weight (b) of the component (B) is around 50% by weight, the weight (c) of the component (C) is around 30% by weight, and (a + b + c): d = 40: 60 to 70:30. preferable.

Then, a dispersant for adhering to the polyester fiber for paper is prepared by using the above components (A) to (D) in a ratio satisfying the above numerical formula. The dispersant is usually preferably in the form of an aqueous dispersion, and even if the aqueous dispersion contains only the components (A) to (D),
Alternatively, a small amount of other components such as a surfactant, a silicon-based defoaming agent, a non-silicon-based defoaming agent (for example, a polyether-based defoaming agent), and an organic solvent may be included, if necessary.
However, when a silicone-based defoaming agent is used, care should be taken because if used in a large amount, silicon may remain in the obtained polyester fiber paper and cause trouble.

In the dispersant in the form of an aqueous dispersion, the total amount of components (A) to (D) is adjusted to about 5 to 50% by weight based on the total weight of the aqueous dispersion. In this case, the viscosity of the aqueous dispersion of the dispersant becomes appropriate and the handling becomes good, and moreover, the required amount of components (A) to (D) is evenly distributed in the polyester fiber. Can be attached with good processability.

The amount of the dispersant attached to the polyester fibers is based on the weight of the polyester fibers, and the amount of the component (A) to
The total weight of component (D) is preferably 0.1% by weight to 2.0% by weight, more preferably 0.4 to 1.0% by weight. When the amount of the dispersant attached is less than 0.1% by weight, it becomes difficult to impart good water dispersibility to the polyester fiber, and it becomes difficult to obtain a polyester fiber paper excellent in homogeneity, texture and paper strength. . On the other hand, even if the amount of the dispersant attached to the polyester fiber exceeds 2.0% by weight, the water dispersibility of the polyester fiber is not so good as compared with the case of 2.0% by weight or less, and a large amount of the dispersant is used. It is uneconomical because of the high cost.

The method of applying the dispersant to the polyester fibers is not particularly limited, and any method may be used as long as it can be uniformly applied to the surface of the polyester fibers. In attaching the dispersant to the polyester fiber, for example, a method of attaching the polyester fiber at the stage of the long fiber before spinning or after spinning / spinning / stretching of the polyester fiber, or by winding the polyester fiber and then rewinding A method of adhering in a fiber state, a method of adhering after cutting polyester fibers into short fibers, etc. can be adopted, and as a method of adhering the dispersant at that time, a roll coating method, a slit nozzle imparting method, a jet nozzle inside Can be applied from the entire circumference of the yarn, a dipping method, a method using a spray nozzle, and the like.

Then, the polyester fiber for paper of the present invention to which the dispersant is attached is obtained by the above. The polyester fiber to which the aqueous dispersion of the dispersant is attached may be directly used for papermaking in a wet state, or may be once dried and then used for papermaking. The polyester fiber obtained by adhering the aqueous dispersion of the dispersant to the polyester fiber and then drying it to remove water has excellent handleability and can be stored, distributed and sold in a stable state. .

The polyester fiber for paper used in the present invention may be any polyester fiber known to be used in polyester fiber paper, and is not particularly limited, but polyethylene terephthalate, polybutylene terephthalate, or A copolyester in which an ethylene terephthalate unit and / or a butylene terephthalate unit is a main constituent unit and a small amount of another copolymerization unit is contained therein is preferably used, and polyethylene terephthalate is particularly preferably used.

When a polyester mainly comprising ethylene terephthalate units and / or butylene terephthalate units is used as the polyester fiber, the proportion of other copolymerized units in the copolyester is preferably 10 mol% or less. Examples of other copolymerized units include aromatic carboxylic acids such as isophthalic acid, phthalic acid, 2,6-naphthalene dicarboxylic acid, and 5-alkali metal sulfoisophthalic acid; oxalic acid, adipic acid, azelaic acid, sebacine. Aliphatic carboxylic acids such as acids; polyfunctional carboxylic acids such as trimellitic acid and pyromellitic acid; or carboxylic acid units derived from their ester-forming components; diethylene glycol, propylene glycol,
Examples thereof include units derived from 1,4-butanediol, polyethylene glycol, glycerin, pentaerythritol and the like. The copolyester can contain one or more of the above-mentioned copolymerized units.

In the present invention, the viscosity and molecular weight of the polyester used for the polyester fiber for paper are not particularly limited, but generally, it is measured at 30 ° C. in a mixed solution of phenol and tetrachloroethane by using an Ubbelohde viscometer. Sometimes, the intrinsic viscosity [η] is 0.40 to 0.65g
It is preferable to use a polyester of / dl from the viewpoint of strength, texture and uniformity of the obtained polyester paper.

The polyester fiber for paper preferably has a fiber length of about 3 to 40 mm from the viewpoints of water dispersibility of the polyester fiber, paper formability, strength of the obtained paper, feel, uniformity and the like. More preferably, it is about 5 to 20 mm. The polyester fiber for paper has a monofilament fineness of about 0.1 to 10 denier, which means that the water dispersibility of the polyester fiber, the paper-making property, the strength, feel, and uniformity of the obtained polyester fiber paper, It is preferable in terms of wet strength. Further, although not limited, the polyester fiber for paper has an aspect ratio represented by a fiber length / fiber diameter of about 100 to 5,000, which means that the water dispersibility is
Papermaking property, uniformity of the obtained polyester fiber paper, texture,
It is preferable in terms of paper strength, wet strength and the like. And, as the polyester fiber, a normal round cross-section is preferably used, but is not limited thereto, and in some cases, for example, elliptical, triangular, square, polygonal, multilobal, arrayed, It may be a V-shaped or T-shaped deformed cross-section fiber.

The polyester fiber may be used, if necessary.
Matting agent, antistatic agent, deodorant, fragrance, light stabilizer, antioxidant, ultraviolet absorber, flame retardant, dye / pigment, optical brightener,
You may contain 1 type, or 2 or more types, such as a heat storage agent.

In the production of paper, the polyester fiber for paper to which the dispersant obtained above is attached may be used alone for papermaking, or other fibers may be used in combination to produce a mixed paper. Good. When mixed with other fibers, rayon, pulp, vinylon, acrylic fiber, polyamide fiber, polypropylene fiber, polyethylene fiber, polyethylene / polypropylene composite fiber, ethylene-vinyl acetate copolymer fiber, polyvinyl chloride fiber, vinyl chloride- Fibers such as vinyl acetate copolymer fibers can be used,
These fibers may be used alone or in combination with two or more kinds. When mixed with other fibers, the use ratio of the other fibers is not particularly limited, and can be appropriately determined depending on the type of the target paper, properties, applications, etc., and even if there are more polyester fibers, More other fibers may be present, or polyester fibers and other fibers may be in the same amount. Then, when it is desired to obtain a paper utilizing the characteristics such as flexibility, dimensional stability and heat resistance of the polyester fiber, generally, the ratio of the other fiber is 50% by weight based on the total weight of the polyester fiber and the other fiber. It is better to set it to% or less.

In some cases, binder fibers may be used, and examples of the binder fibers include water-soluble polyvinyl alcohol fibers known as easily soluble vinylon and water-soluble isophthalic acid copolymerized polyester fibers. Examples thereof include low-melting point polyester fibers which have not been subjected to a stretching treatment. When the binder fiber is used, its amount is preferably about 1 to 50% by weight based on the total weight of the polyester fiber and the above-mentioned other fiber (when used).

When the paper is produced by using the polyester fiber of the present invention to which the dispersant is adhered, or optionally in combination with other fiber or binder fiber, it is carried out according to the usual wet papermaking method. You can In wet papermaking, an aqueous slurry containing polyester fibers and optionally other components is prepared, and papermaking is performed using the aqueous slurry, but the solid content concentration in the aqueous slurry (total concentration of polyester fibers and other solids Is preferably about 0.1 to 10% by weight, because papermaking properties, uniformity of the obtained paper, texture, wet strength and the like are improved. And after the web (paper layer) is constructed by papermaking,
If necessary, by stacking a plurality of them, and further performing hydroentangling treatment or the like, by performing a normal dehydration step and a drying step, excellent uniformity and texture,
Moreover, it is possible to obtain strong and excellent paper. In that case, since it is not essential to perform heat treatment after drying, no special heat treatment device is required.

The polyester fiber paper and the mixed paper of polyester fiber and other fibers of the present invention obtained as described above have excellent properties (particularly moisture resistance, flexibility, dimensional stability, heat sealability, uniformity, high It can be effectively used in many applications such as various filters, batteries, battery separators, wipers, drainage bags, etc. by taking advantage of its properties such as strength, water absorption and water retention.

[0041]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. In the following examples, the water dispersibility of polyester fibers, the foamability of dispersants, and the tenacity of the resulting polyester fiber paper (polyester fiber / pulp mixed paper) were evaluated or measured as follows.

[I] Water Dispersibility of Polyester Fiber : (1) A beaker was charged with 2000 cc of ion-exchanged water, and the polyester fiber and pulp (softwood pulp; average fiber length about 2 mm) having a dispersant attached thereto were both added. Was added in a weight ratio of 40/60 to prepare an aqueous slurry having a solid content concentration of 0.05% by weight, and the mixture was stirred for 1 hour with a propeller stirrer (rotation speed 200 rpm), and then a tappy paper machine was used. Papermaking, dehydration and drying (drying temperature 1
20 ° C), length x width x thickness = 5 cm x 15 cm x 0.5 m
m polyester fiber / pulp mixed paper was produced. (2) By observing the surface of the mixed paper obtained in (1) above with the naked eye, counting the number of spots where dislocations of fibers are caused and lumps due to agglomeration are counted, per unit area (75 cm ² ). , Very good when the number is 0 to 1 (◎), 2
The case of ˜5 was evaluated as good (◯), and the case of more than 5 was evaluated as bad (×).

[II] Foamability of the dispersant : Ion-exchanged water 100 in a domestic mixer ("MX100" manufactured by National)
0 cc was added, and 1 g of polyester fiber having a dispersant attached thereto was added thereto to prepare an aqueous slurry of polyester fiber, and this slurry was stirred at a rotation speed of 500 rpm for 15 minutes. The stirred slurry thus obtained was transferred to a beaker, the foamed state on the surface of the polyester fiber and the foamed state between the polyester fiber and the polyester fiber were observed with the naked eye, and it was extremely good when no foaming occurred (◎ ), The case where the degree of foaming is very small and it can be considered that there is almost no foaming is evaluated as good (∘), and the case where foaming is occurring over the entire paper and severe is evaluated as poor (x).

[III] Polyester fiber paper (polyester
Strength of mixed fiber / pulp paper) : (1) Put 2000 cc of ion-exchanged water in a beaker and attach a dispersant to the polyester fiber and pulp (softwood pulp; average fiber length about 2 mm) by weight ratio of both. Of 40/60 to prepare an aqueous slurry having a solid content concentration of 0.05% by weight. Using this aqueous slurry, papermaking is performed by a Reser machine paper machine (“MR-1 type” manufactured by Mitsubishi Reser Machine Co., Ltd.), and four webs (paper layers) in a wet state are stacked to perform hydroentanglement (waterflow speed 2 m / sec). After dehydration and drying (drying temperature 120 ° C.), a polyester fiber / pulp mixed paper having a thickness of 0.5 mm (basis weight 80 g / m ² ) was produced. (2) The polyester fiber / pulp mixed paper obtained in the above (1) was cut into a width of 15 cm, and an Instron tensile tester was used to measure the traveling direction (M
D) and the tenacity in the direction (CD) at right angles thereto were respectively measured according to JIS P8113, and the square root of the product [that is, (MD × CD) ^1/2 ] was determined to be the paper tenacity.

Examples 1 to 14 (1) As shown in Table 1 below, nitrogen of an amide composed of stearic acid and triethylenetetramine as component (A) for use in each example. 8 of a polyoxyalkylene stearamide having a block copolymer group consisting of a polypropylene oxide block / polyethylene oxide block bonded to each atom
Different types were prepared (molecular weight: 300 to 4000; the molar ratio of propylene oxide unit: ethylene oxide unit in the block copolymer group consisting of polypropylene oxide block / polyethylene oxide block is about 7: 3). (2) As shown in Table 1 below, for use in each Example, as a component (B), a block copolymer group composed of a polypropylene oxide block / polyethylene oxide block is bonded to a hydroxyl group of rapeseed oil. Of polyoxyalkylene triglyceride
Different types were prepared (molecular weight: 700 to 8000; the molar ratio of propylene oxide unit: ethylene oxide unit in the block copolymer group consisting of polypropylene oxide block / polyethylene oxide block is about 4: 6).

(3) As shown in Table 1 below, as a component (C), a block copolymer group consisting of a polypropylene oxide block / polyethylene oxide block was added to the monostyrylphenyl group for use in each example. 10 kinds of polyoxyalkylene monostyrenated phenyl ethers in which are bonded (molecular weight 500 to 6000; molar ratio of propylene oxide unit: ethylene oxide unit in the block copolymer group consisting of polypropylene oxide block / polyethylene oxide block) were prepared. Is about 6: 4). (4) As shown in Table 1 below, 14 kinds of sodium polyacrylate were prepared as the component (D) for use in each example (the molecular weight was 1000 to 1).
5000).

(5) As shown in Table 1 below, ion-exchanged water having a predetermined molecular weight of the component (A) prepared in the above (1) and a predetermined molecular weight of the component (B) ,
The weight ratio of [Component (A): Component (B): Component (C): Component (D) is the same as the weight ratio of the components (C) and (D). An aqueous dispersion of the dispersant was prepared by adding it at a ratio such that the total concentration of the components (A), (B), (C) and (D) in the aqueous dispersion was 30% by weight. %].

(6) Using polyethylene terephthalate (intrinsic viscosity [η] = 0.48), the spinning temperature is 300 ° C.,
After melt spinning at a take-up speed of 1400 m / min, drawing was carried out at a temperature of 90 ° C. (drawing ratio 300%) to produce a polyester fiber having a single fiber fineness of 0.5 denier. After cutting this polyester fiber into a fiber length of 15 mm, the aqueous dispersion of the dispersant prepared in (5) above is sprayed onto the fiber uniformly, and based on the weight of the polyester fiber, the components (A) to (D). Produced a polyester fiber for paper having a total amount of 0.5% by weight attached thereto. (7) Polyester fiber paper (polyester fiber / pulp mixed paper) according to the method described in [I] above, using the polyester fiber for paper obtained in (6) above.
Was produced and the water dispersibility of the polyester fiber was evaluated. The results are shown in Table 1 below. . Further, by using the polyester fiber for paper obtained in (6) above,
When the foamability of the dispersant was evaluated according to the method described in [II] above, it was as shown in Table 1 below.

[0049]

[Table 1]

From the results of Table 1 above, the molecular weight of 300-4
Dispersant containing 000 component (A), molecular weight 700 to 8000 component (B), molecular weight 500 to 6000 component (C) and molecular weight 1000 to 15000 component (D) in proportions satisfying the above mathematical formulas. The polyester fibers for paper obtained in Examples 1 to 14 having excellent adhesion are excellent in water dispersibility, and foaming does not occur.
It can be seen that the polyester fiber paper (polyester fiber / pulp mixed paper) obtained from it has no uniformity due to poor dispersion of fibers and generation of lumps due to agglomeration.

Examples 15 to 21 and Comparative Examples 1 to 7 (1) As the component (A), a block consisting of a polypropylene oxide block / polyethylene oxide block with respect to the nitrogen atom of the amide consisting of adipic acid and stearylamine. Molecular weight 1 with a copolymer group attached
000 polyoxyalkylene adipic amides were prepared (the molar ratio of propylene oxide units: ethylene oxide units in the block copolymer group consisting of polypropylene oxide block / polyethylene oxide block was 7: 3). (2) As the component (B), a polyoxyalkylene triglyceride having a molecular weight of 2000 in which a block copolymer group consisting of a polypropylene oxide block / polyethylene oxide block is bonded to a hydroxyl group of rapeseed oil was prepared (polypropylene oxide block / polyethylene). The molar ratio of propylene oxide units: ethylene oxide units in the block copolymer group consisting of oxide blocks is 4: 6).

(3) As the component (C), a polyoxyalkylene monostyrenated phenyl ether having a molecular weight of 1500 in which a block copolymer group of polypropylene oxide block / polyethylene oxide block is bonded to a monostyrylphenyl group was prepared. (The molar ratio of propylene oxide unit: ethylene oxide unit in the block copolymer group consisting of polypropylene oxide block / polyethylene oxide block is 6: 4). (4) As the component (D), sodium polyacrylate having a molecular weight of 6000 was prepared.

(5) To 1000 cc of ion-exchanged water, the components (A) to (D) prepared in (1) above were added at the weight ratios shown in Table 2 below to give an aqueous dispersion of the dispersant. [Prepared total content of component (A), component (B), component (C) and component (D) based on the total weight of the aqueous dispersion 30]
weight%].

(6) An aqueous dispersion of the dispersant prepared in the above (5) was sprayed onto a polyester fiber having a single fiber fineness of 0.5 denier and a fiber length of 15 mm produced in the same manner as in (6) of Example 1. Then, based on the weight of the polyester fiber, a polyester fiber for paper to which components (A) to (D) were attached in a total amount of 0.5% by weight was produced. (7) Using the polyester fiber for paper obtained in (6) above, polyester fiber paper (polyester fiber / pulp mixed paper) is produced according to the method described in [I] above, and the polyester fiber is dispersed in water. When the sex was evaluated, the results were as shown in Table 2 below. Further, by using the polyester fiber for paper obtained in (6) above,
When the foamability of the dispersant was evaluated according to the method described in [II] above, it was as shown in Table 2 below.
Furthermore, using the polyester fiber for paper obtained in (6) above, according to the method described in [III] above, polyester fiber paper (polyester fiber / pulp mixed paper)
Was produced, and its strength was measured. The results are shown in Table 2 below.

[0055]

[Table 2]

From the results shown in Table 2 above, the component (A) having a molecular weight of 1000, the component (B) having a molecular weight of 2000, and the molecular weight of 15
The polyester fibers of Examples 15 to 21 to which the dispersant containing the component (C) of No. 00 and the component (D) of molecular weight 6000 in a ratio satisfying the above formulas (1) to (5) are attached,
It has excellent water dispersibility and does not cause foaming. Therefore, the polyester fiber paper (polyester fiber / pulp mixed paper) obtained from it is excellent in uniformity because it does not cause dislocation of fibers and no lumps due to agglomeration. And the paper strength [(MD × CD) ^1/2 ] is 1.76 kg /
It can be seen that it has a large strength of m ² or more.

On the other hand, even if the same components (A) to (D) as in Examples 15 to 21 are used, the content ratio of each component does not satisfy any of the above formulas (1) to (4). The polyester fibers of Comparative Examples 1 to 7 to which the dispersant was adhered were inferior in water dispersibility and had large foaming, so that the polyester fiber paper (polyester fiber / pulp mixed paper) obtained therefrom had poor fiber dispersion. A large number of lumps are generated due to agglomeration, and the paper strength [(MD × CD) ^1/2 ] is 0.70 kg /
It can be seen that the strength is inferior because it is less than m ² .

[0058]

Industrial Applicability The polyester fiber for paper of the present invention is excellent in water dispersibility and does not cause foaming when dispersed in water. Therefore, the polyester fiber of the present invention is used for polyester fiber paper or polyester fiber. In the case of producing a mixed-fiber paper with the other fiber, it is possible to produce a high-quality paper excellent in uniformity, texture (texture) and paper strength. Further, in the case of producing a paper using the polyester fiber for paper of the present invention, regardless of the size of the aspect ratio of the polyester fiber, a paper having the above excellent properties, without requiring a defoaming step, It can be manufactured with high productivity by a simple process.

Continuation of front page (56) Reference JP-A-3-180587 (JP, A) JP-A-1-298297 (JP, A) JP-A-3-227493 (JP, A) JP-A-6-93567 (JP , A) JP-A-2-242977 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) D21B 1/00-1/38 D21C 1/00-11/14 D21D 1/00 -5/28 D21F 1/00-13/12 D21G 1/00-9/00 D21H 11/00-27/42 D21J 1/00-7/00 D06M 13/00-15/72

Claims (4)

(57) [Claims] 1. A polyoxyalkylene fatty acid amide having a molecular weight of 300 to 4000, and a molecular weight of 700 to 8 (B).
000 polyoxyalkylene triglycerides, (C)
Polyoxyalkylene styrenated phenyl ether having a molecular weight of 500 to 6000 and (D) a molecular weight of 1000 to 1
The polycarboxylic acid salt of 5000 is represented by the following mathematical formulas :; {a / (a + b + c)} × 100 = 10 to 30 (wt%) {b / (a + b + c)} × 100 = 20 to 80 (wt%) ) {C / (a + b + c)} × 100 = 10 to 50 (% by weight) a: c = 1: 0.2 to 1: 3 (a + b + c): d = 20: 80 to 80:20 (where a = The weight of the polyoxyalkylene fatty acid amide b = the weight of the polyoxyalkylene triglyceride c = the weight of the polyoxyalkylene styrenated phenyl ether d = the weight of the polycarboxylic acid salt). Characteristic polyester fiber for paper. 2. The paper according to claim 1, wherein the amount of the dispersant attached is 0.1 to 2.0% by weight based on the weight of the polyester fibers, based on the total weight of the components (A) to (D). For polyester fiber. 3. A paper comprising the polyester fiber for paper according to claim 1 or 2. 4. A polyoxyalkylene fatty acid amide having a molecular weight of 300 to 4000, and a molecular weight of 700 to 8 (B).
000 polyoxyalkylene triglycerides, (C)
Polyoxyalkylene styrenated phenyl ether having a molecular weight of 500 to 6000 and (D) a molecular weight of 1000 to 1
The polycarboxylic acid salt of 5000 is represented by the following numerical formulas: {a / (a + b + c)} × 100 = 10 to 30 (wt%) {b / (a + b + c)} × 100 = 20 to 80 (wt%) ) {C / (a + b + c)} × 100 = 10 to 50 (% by weight) a: c = 1: 0.2 to 1: 3 (a + b + c): d = 20: 80 to 80:20 (where a = Polyester for paper, characterized in that the content of polyoxyalkylene fatty acid amide b = weight of polyoxyalkylene triglyceride c = weight of polyoxyalkylene styrenated phenyl ether d = weight of polycarboxylic acid salt) is satisfied. Fiber dispersant.