JPH10331091A - Polyester fiber for making paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain polyester fibers exhibiting good dispersibility and foamability in a paper-making process and used for making paper by imparting a specific polyesterpolyether block copolymer as a dispersing agent to polyester fibers. SOLUTION: The polyester fibers for making paper are obtained by imparting a dispersing agent in an amount of 0.05-2 wt.%, preferably 0.2-1 wt.%, to polyester fibers. The dispersing agent comprises a polyesterpolyether block copolymer produced by polymerizing a dicarboxylic acid having a 10-14C condensed multi- cyclic hydrocarbon skeleton, such as naphthalene dicarboxylic acid, a 6-10C aliphatic dicarboxylic acid such as adipic acid, a lower alkylene glycol and a dialkylaminoether.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a papermaking polyester fiber suitable for producing a polyester fiber paper. More specifically, the present invention relates to a polyester fiber for papermaking, which is characterized by exhibiting good dispersibility and excellent foamability in papermaking of polyester staple fiber, and having a dispersant imparting high paper strength as a product.

[0002]

2. Description of the Prior Art Vinylon, rayon, natural cellulose, polypropylene and polyacrylonitrile fibers have been used quite widely as fibers for papermaking, but recently, the required performance has been improved and the cost has been increased. It has a unique soft feel among various fiber papers due to reduction of dimensional stability,
The development of polyester fiber paper that is heat resistant and inexpensive has been considerably advanced.

[0003] However, at present, there are almost no products put to practical use, and the excellent performance of polyester itself is not fully utilized. In particular, in the papermaking process, the dispersibility of the polyester fiber is improved, the production rate is improved, and the foamability is low.As a result, the wet dispersant for giving a polyester fiber paper having good formation and high paper strength is At present, it has not been found yet.

Conventionally used dispersants include:
For example, a mixture of water-soluble polyurethane, polyoxyalkylene ether, hydrophilic polyester having a sulfonic acid group and the like at an appropriate ratio, or only a single composition has been used. However, none of them gave good dispersibility of fibers, and it was not possible to obtain a paper having sufficient strength.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polyester fiber paper which has good dispersibility and excellent defoaming properties which cannot be obtained by the prior art, and has a good formation. The purpose of the present invention is to provide a high-strength polyester fiber paper.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies in order to achieve the above-mentioned object, and as a result, have found that a dicarboxylic acid having a condensed polycyclic hydrocarbon group having 10 to 14 carbon atoms, and a dicarboxylic acid having 6 to 10 carbon atoms.
Of a polyester polyether block copolymer dispersant comprising an aliphatic dicarboxylic acid, a lower alkylene glycol and a dialkylamino ether in an amount of 0.0
It has been found that a polyester fiber paper having good dispersibility and high paper strength can be obtained by forming a polyester fiber added to a 5 to 2% by weight fiber.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The dicarboxylic acid component used in the production of the polyester polyether block copolymer of the present invention comprises a dicarboxylic acid having a condensed polycyclic hydrocarbon group having 10 to 14 carbon atoms and a dicarboxylic acid having 6 to 10 carbon atoms. It is important to use an aliphatic dicarboxylic acid in combination. As the dicarboxylic acid having a condensed polycyclic hydrocarbon group having 10 to 14 carbon atoms, for example, a dicarboxylic acid having a naphthalene skeleton, a dicarboxylic acid having a condensed polycyclic hydrocarbon skeleton having 10 to 14 carbon atoms such as a dicarboxylic acid having an anthracene skeleton An acid can be used, and in the present invention, it is preferable to use naphthalenedicarboxylic acid. As the aliphatic dicarboxylic acid having 6 to 10 carbon atoms, adipic acid, suberic acid, sebacic acid and the like can be used, and adipic acid is particularly preferable. In the present invention, the dicarboxylic acid component may be used by appropriately combining the above dicarboxylic acids, but the combination of naphthalenedicarboxylic acid and adipine is most preferred. Here, the carbon number of the aliphatic dicarboxylic acid,
It refers to the number of carbons including the carbon of the carboxyl group, and the number of carbons of the dicarboxylic acid having the condensed polycyclic hydrocarbon skeleton refers only to the carbons constituting the polycyclic ring.

As the lower alkylene glycol, lower alkylene glycols having about 2 to 6 carbon atoms, such as ethylene glycol, propylene glycol, tetramethylene glycol, pentamethylene glycol, and diethylene glycol, are preferred. Particularly, ethylene glycol is preferred.

As the dialkylamino ether, dimethylaminoether, diethylaminoether, dipropylaminoether and dibutylaminoether are suitable, and have an average molecular weight of 500 to 6000, preferably 80.
0 to 4500 is preferred.

[0010] In the block copolymer, the composition ratio of the dicarboxylic acid having a condensed polycyclic hydrocarbon group and the aliphatic dicarboxylic acid is set so as to balance the heat resistance and the polymerizability of the target oil agent. For example, when naphthalenedicarboxylic acid and adipic acid are used, it is preferable from the viewpoint of dispersibility that the naphthalate unit: adipate unit is in the range of 90:10 to 30:70 as the repeating unit. . Also, naphthalate unit + adipate
G unit: dialkylamino ether unit is 2: 1 to 8:
It is particularly preferable that it is in the range of 1 (molar ratio) from the viewpoint of improving dispersibility.

The average molecular weight of the block copolymer is usually 3,000 to 20,000, preferably 4,000 to 12,
000. If the molecular weight is out of this range, it is difficult to obtain good dispersibility, and problems arise in the solubility of the dispersant, foaming during dissolution, foaming during papermaking, and the like.

The polyester fiber suitable for the present invention is appropriately selected depending on the desired paper quality, but the fiber length is 2
The paper material is cut to a size of 30 mm to 30 mm, preferably 3 mm to 15 mm. In addition, as a raw material polymer,
Polyethylene terephthalate is optimal, but its acid component and / or diol component is partially isophthalic acid,
Dicarboxylic acids such as adipic acid, sebacic acid, 5-sodium sulfoisophthalic acid, diethylene glycol, 1,
Copolyesters substituted by diols such as 4-butanediol, neopentyl glycol and polyethylene glycol may also be used.

[0013] These polyesters may contain a matting agent, an antistatic agent, a deodorant, a fragrance, a flame retardant and the like.

In the present invention, the adhesion of the block copolymer dispersant to the fibers is 0.05% by weight or more and 2% by weight or less, preferably 0.2% by weight or more and 1% by weight or less. That is, when the content is less than 0.05% by weight, it is difficult to provide good dispersibility. When the content is more than 2% by weight, the dispersibility is good, but not only the cost is increased but also a waste amount is provided. You don't need to do that. The means for applying the dispersant used in the present invention to the fibers is not particularly limited, and can be applied after spinning and drawing by a conventional method.

The polyester fiber used in the present invention to which a specific amount of the dispersant is added has good dispersibility, so that it is possible to make paper alone, but it may be mixed with other fibers. Rayon, pulp, vinylon, acrylic,
Combinations with one or more other fibers, such as nylon, are contemplated. Further, as the binder fiber, for example, a PVA-based water-soluble fiber generally known as easily soluble vinylon can be used.

The paper is made from the above-mentioned stock by a conventional wet papermaking method. And after forming the paper layer,
A strong polyester paper can be obtained through a normal dehydration step and drying step, and can be made without a special heat treatment machine.

[0017]

The present invention will be described below with reference to examples.
The present invention is not limited by these examples. The test method in the examples is as follows. (1) Dispersion test One liter of a solution having a fiber concentration of 0.05% was stirred with a TAPPI disintegrator (manufactured by Kumagai Seiki Co., Ltd.) at 3000 rpm for 1 minute, and T
The number of binding fibers after papermaking with an APPI paper machine was counted. (2) Foaming test After adjusting the oil agent to a concentration of 50 ppm, 50 ml was used for a shinto machine (270 times / min, amplitude 90 mm, manufactured by Iwaki Co., Ltd.).
3 minutes, and measure the height of the foam from the liquid level after stopping (m
m). (3) Papermaking test The fiber to which the dispersant was added was adjusted so that the fiber concentration became 0.2% by weight, and a 0.2 wt% thickener (manufactured by Meisei Chemical Industry Co., Ltd., trade name: Alcox SR) was also used. added. These mixed solutions were supplied to a TAPPI paper machine (round type) to make paper.
The temperature of the dry part was set at 105 ° C. and drying was performed. The basis weight of the obtained polyester fiber paper is 30 g / m ² ,
The paper strength of these polyester fiber papers was examined.

Examples 1 to 3 and Comparative Examples 1 and 2 Various dispersants were obtained with the compositions and composition ratios shown in Table 1 according to a usual polyester polymerization method. Next, a polyester having an intrinsic viscosity of 0.62 was added to 1200 m /
A single yarn denier of 1.0 d to obtain an undrawn yarn of 1.0 d, and cut the undrawn yarn into a length of 5 mm to obtain a single yarn denier of 0.4 d and a fiber length of 3 mm. It was dispersed in water so as to have a ratio of 30:70 with the drawn polyester short fiber, and a dispersion test and a papermaking test were performed on various dispersants. The type and amount of the dispersant applied to the undrawn yarn and the drawn yarn, the adhesion amount, and the test results are as shown in Table 1.

[0019]

[Table 1]

When the dispersant of the present invention was used, compared with Comparative Examples 1 and 2, there were almost no binding fibers and the foamability was low, so that the formation was good and the paper strength was 0.55 kg.
/ 15 mm or more.

Comparative Examples 3 and 4 In the same manner as in Examples 1 to 3, only the type of the dispersant was changed as shown in Table 2 to obtain a dispersion test, a foaming test,
A papermaking test was performed. The dispersion state of both Comparative Examples 3 and 4 was not preferable.

[0022]

[Table 2]

[0023]

The polyester fiber for papermaking to which the dispersant of the present invention has been applied exhibits extremely excellent dispersibility and foamability in the papermaking process, and the obtained polyester fiber has a stronger paper strength than conventional similar paper. It is excellent.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasunori Murate 7471 Tamashima Otoshima, Kurashiki City, Okayama Prefecture Kuraray Co., Ltd.

Claims (2)

[Claims] 1. A polyester polyether comprising a dicarboxylic acid having a condensed polycyclic hydrocarbon skeleton having 10 to 14 carbon atoms, an aliphatic dicarboxylic acid having 6 to 10 carbon atoms, a lower alkylene glycol and a dialkylamino ether. A polyester fiber for papermaking, characterized in that a block copolymer dispersant is added to the fiber in an amount of 0.05 to 2% by weight based on the fiber. 2. The dicarboxylic acid having a condensed polycyclic hydrocarbon skeleton having 10 to 14 carbon atoms is naphthalenedicarboxylic acid,
2. The papermaking polyester fiber according to claim 1, wherein the aliphatic dicarboxylic acid having 6 to 10 carbon atoms is adipic acid.