JPS61282424A - Polyester monofilament for screen plain gauge - Google Patents

Abstract

PURPOSE:The titled filament having specific intrinsic viscosity, specified titanium oxide content, specific amount of carboxyl residue, high toughness, high modulus, improved resistance to fibrillation and high fastness to wet friction and slightly slackening. CONSTITUTION:The titled polyester monofilament having 0.7-1.2 intrinsic viscosity, <=0.1wt% titanium oxide, <=25<eq>/10<6>g carboxyl residue amount and preferably 9-20 denier fineness. The polyester is preferably polyethylene terephthalate.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a polyester monofilament for screen shearing. More particularly, the present invention relates to a screen shear polyester suitable for use in the manufacture of IC wiring prints.

(Prior Art) Polyester monofilaments, particularly polyethylene terephthalate monofilaments, have many excellent properties and have traditionally been used in screen shears. This conventionally used polyester monofilament is a normal semi-dull yarn and has an intrinsic viscosity of 0.
65, titanium oxide content is around 0.5% by weight, and carboxylic acid residue amount is 30 to 50 eq/106 g.

(Problems to be Solved by the Invention) However, such conventional polyester monofilaments have low toughness and modulus, poor fibril resistance, which causes fibrillation during weaving, and furthermore, low fastness to wet rubbing. When a shear is woven and used for printing, there is a problem that it is easily worn out and has a short lifespan as a shear.

In particular, the screen shear used for IC wiring printing requires an extremely precise shear of 200 to 280 meshes, and if the monofilament that makes up the shear becomes even slightly sagging or fibrillated, it becomes unusable. Polyester monofilament has the problem that sagging and fibrils are likely to occur during printing, and the service life of the shear is extremely short.

The purpose of the present invention is to solve the problems of the conventional polyester monofilament for screen shearing, to have high toughness, high modulus, excellent fibril resistance, high fastness to wet rubbing, and to prevent sagging on the shear during weaving as well as printing. To provide a polyester monofilament that is less likely to undergo fibrillation.

(Means for solving the problems) The present invention has an intrinsic viscosity of 0.7 to 1.2, a titanium oxide content of 0.001% by weight or less, and a carboxylic acid residue amount of 25 eq/
This is a polyester monofilament for screen shearing, characterized in that it weighs 106 g or less.

The polyester monofilament referred to in the present invention is primarily a monofilament made of polyethylene terephthalate. However, even if it is a monofilament made of a polyester containing ethylene terephthalate as the main repeating unit and a small proportion (usually 20 mol% or less) of a third component other than the terephthalic acid component and the ethylene glycol component copolymerized and/or mixed. good. Furthermore, arbitrary additives may be mixed into the monofilament as required. Such a monofilament may be melt-spun as a multifilament, drawn and then split, or may be melt-spun and drawn as a monofilament from the beginning.

The above-mentioned polyester monofilament has a remarkable effect when the monofilament has a fineness of 20 deniers or less, particularly a monofilament having a fineness of 5 to 15 deniers.

The polyester monofilament of the present invention has an intrinsic viscosity of 0.
．． It is necessary to be within the range of 7 to 1.2. If the intrinsic viscosity is less than 0.7, the toughness and modulus will be low, resulting in poor fibril resistance. Conversely, if the intrinsic viscosity exceeds 1.2, spinning and drawing become difficult. Here, the value of the intrinsic viscosity is measured in an O-dichloroenol solution at 25°C.

Further, in the polyester monofilament of the present invention, the titanium oxide content must be 0.1% by weight or less.

If the titanium oxide content exceeds 0.1% by weight, the frictional resistance on the fiber surface will increase, and the fibril resistance and wet rubbing fastness will decrease. The amount must be 25eq/106g or less.

If the amount of carboxylic acid residue exceeds 25 eq/106 g, it is unsuitable because the wet rubbing fastness when made into a shard decreases. In order to adjust the amount of carboxylic acid residues, an end-blocking agent that reacts with carboxylic acid terminals may be appropriately added during the polymerization process, polymer melting process, etc.

Examples of such an end-blocking agent include a method in which polyester is reacted with a cyclic carbonate as disclosed in Japanese Patent Publication No. 4B-41713, or a biscyclic iminoether as disclosed in Japanese Unexamined Patent Publication No. 55-145734. .

(Example) The present invention will be described in detail with reference to Examples below. In each Example and Comparative Example, toughness, modulus, fibril resistance, and fastness to wet rubbing were measured by the following methods.

(b) Toughness Evaluation was performed using the following formula.

Strength x (square root of elongation at break) (b) Using a modulus tensile tester, measure the stress at 1% elongation, kg
/cn+".

(c) Fibril resistance Using a TM type platform resultant force tester manufactured by Taishu Kagaku Seiki Seisakusho, the fibers were rubbed 1500 times with a metal comb under a load of 1 kg, and the fiber surface condition was observed. Rated in stages.

(d) Wet rubbing fastness was evaluated using the above-mentioned TM type platform resultant force tester and the above-mentioned method using wetted yarn.

Examples 1 to 3, Comparative Examples 1 to 3, the polymerization conditions of polyethylene terephthalate were variously changed,
And in the polymerization process, 2,2'-bis(2
-Oxazoline) was added in various amounts to obtain polyethylene terephthalates having different intrinsic viscosities and amounts of carboxylic acid residues as shown in Table 1. Note that the titanium oxide content is 0.
It was 0.3%.

Each polyethylene terephthalate was discharged from a spinneret having one nozzle with a hole diameter of 0.45 m, and the spinning speed was 6.
The monofilament was spun at 00 m/min and then drawn 4.0 times to obtain a monofilament with a fineness of 15 denier.

A screen shear of 270 meshes was woven using this monofilament. The measurement results of toughness, modulus, fibril resistance, and fastness to wet rubbing are shown in Table 1.

Table 1 As is clear from Table 1, the intrinsic viscosity is 0.7 to 1.
According to the monofilaments of the present invention (Examples 1 to 4) in which the amount of carboxylic acid residue is 25 eq/106 g or less in 2, a product with high toughness and modulus and excellent fibril resistance and wet rub fastness can be obtained. , the intrinsic viscosity is 0.7
If it is less than (Comparative Example 1), both toughness and modulus are low, resulting in poor fibril resistance. On the other hand, when the intrinsic viscosity exceeds 1.2 (Comparative Example 2), spinning and stretching become difficult.

Moreover, when the amount of carboxylic acid residue exceeds 25 eq/106 g (Comparative Example 3), the fastness to wet rubbing decreases.

In Examples 5 and 6, Comparative Example 4, and Example 2, the experiments were repeated with various changes in the content of titanium oxide as shown in Table 2, and with the other conditions being the same as in Example 2. The measurement results of toughness, modulus, fibril resistance, and wet rubbing fastness are shown in Table 2.

As is clear from Table 2, the titanium oxide content is 0.
According to the monofilament of the present invention (Example 5.6) in which the titanium oxide content is 1% by weight or less, a product with high toughness and modulus, high fibril resistance, and high fastness to wet rubbing can be obtained, but the titanium oxide content is 0.1% by weight or less. When exceeding weight% (Comparative Example 4
), the fibril resistance and wet rubbing fastness are reduced.

(Effects of the Invention) The polyester monofilament of the present invention has high toughness, high modulus, excellent fibril resistance, high fastness to wet rubbing, and has excellent properties such as being unlikely to cause shear sagging or fibrillation during printing as well as during weaving. It has an effect.

Claims (3)

[Claims] (1) Intrinsic viscosity is 0.7 to 1.2, titanium oxide content is 0.1% by weight or less, and carboxylic acid residue amount is 25 eq/10
A polyester monofilament for screen shearing, characterized by a weight of 6g or less. (2) The polyester monofilament for screen shearing according to claim 1, which has a fineness of 9 to 20 deniers. (3) The polyester monofilament for screen shearing according to claim 1 or 2, wherein the polyester is polyethylene terephthalate.