JPS61136518A - Production of modified polyester - Google Patents

Abstract

PURPOSE:To modify a polyester to make it easily dyeable with a basic dye, by contacting it with sulfuric anhydride in the presence of a polymetallosiloxane compound in its production step. CONSTITUTION:A polymetallosiloxane compound is added to bis(beta-hydroxyethyl) terephthalate of a degree of esterification >=about 95% and its low polymer, and the mixture is polycondensed in vacuum to obtain a prepolymer of an intrinsic viscosity <=about 0.4. Sulfuric anhydride is contacted with the above prepolymer in a molten state at normal pressure or a slight pressure. Said polymetallosiloxane compound is a polymer having a bond of formula I or II (wherein R<1>-R<4> are each H or alkyl, cycloalkyl, aryl or the like, M<1> is an alkaline earth metal and M<2> is a Group III metal), and poly(borodiphenylsiloxane) is particularly desirable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing modified polyester dyeable with basic dyes.

(Prior Art) Polyester, especially polyethylene terephthalate, has excellent mechanical and chemical properties and is used for clothing.

Widely used as an industrial fiber.

By the way, polyethylene terephthalate fibers do not have good dyeability, and various methods have been proposed to improve the dyeability.

The most typical method is to copolymerize polyester with a 5-metal sulfoisophthalic acid component (referred to as SIP) to make it dyeable with basic dyes (Japanese Patent Publication No. 34-10).
Publication No. 497). However, in order to obtain polyester fibers with satisfactory dyeability using this method, a large amount of SIP must be copolymerized.

Due to the thickening effect of SIP, if the intrinsic viscosity (degree of polymerization) of polyester is sufficiently increased, the melt viscosity will become extremely high, making melt spinning difficult, and if the intrinsic viscosity is decreased, only low-strength fibers can be obtained.

It is also known to sulfonate polyester molded products such as fibers and films with sulfuric anhydride to make them dyeable with basic dyes (British Patent No. 749.456). However, this method requires complicated treatment steps, and the treatment with sulfuric anhydride must be carried out under mild conditions.The amount of sulfonation is negligible, making it difficult to provide sufficient dyeability. be.

(Problems to be Solved by the Invention) The present invention aims to provide a method of sulfonating polyester with sulfuric anhydride in the manufacturing process to obtain a polyester dyeable with a basic dye.

(Means for Solving the Problems) The present invention achieves the above objects, and the gist thereof is as follows.

A method for producing a modified polyester, which comprises bringing sulfuric anhydride into contact with a molten polyester oligomer or polymer in the presence of a polymetal siloxane compound, when producing polyethylene terephthalate or a polyester mainly composed of polyethylene terephthalate.

The polyester in the present invention is polyethylene terephthalate, which uses terephthalic acid or an ester-forming derivative thereof and ethylene glycol or an ester-forming derivative thereof as starting materials, or a polyester mainly composed of these.

The polymetal siloxane referred to in the present invention is a polymer having a bond represented by the general formula (I) or (n).

1+S i -0-M'-0←N)R'' 0 -(-Si-0-M2-0←(ff)■ Here, Rl and R4 are hydrogen atoms or alkyl groups.

Cycloalkyl group, aryl group, acyloxy group.

Alkaryl group 8 represents an organic group such as a silyl group, an aralkyl group, a perfluoroalkyl group, etc. 1M" represents an alkaline earth metal + M" represents a metal atom of group (2).

Specifically, polymagnesiodiphenylsiloxane and polymagnesiomethylphenylsiloxane.

Examples include polyborodiphenylsiloxane, polyboromethylphenylsiloxane, polyaluminodiphenylsiloxane, and polyborodiphenylsiloxane is particularly preferred.

The amount of polymetal siloxane added is preferably 1 to 10 parts by weight per 100 parts by weight of polyester to be produced. If the amount added is less than this range, it will take a long time for sulfonation to develop the effect of improving dyeability, or the polymer itself will be oxidized and decomposed.

Even if the amount added exceeds this range, the sulfonation time will be shortened, which is not preferable as it may become brownish to black.

Not only is the color tone improvement effect not promoted, but also foreign matter derived from the polymetal siloxane that is insoluble in the polymer is generated, which is undesirable.

In the present invention, during polycondensation, 1 usually antimony,
Compounds such as titanium and germanium are used as catalysts, and various additives such as matting agents, hydroxides or carboxylates of alkali metals or alkaline earth metals, phosphorus compounds, etc. are added as necessary.

In the present invention, the sulfonation with sulfuric anhydride is preferably carried out after the polymetal siloxane compound is added, at a point when the intrinsic viscosity of the polyester does not exceed 0.4. When the intrinsic viscosity becomes high, the melt viscosity of the polymer becomes high, and uniform sulfonation may not be possible.

In the present invention, the method of bringing sulfuric anhydride into contact with polyester oligomers or polymers is not particularly limited, but it is preferable that the sulfuric anhydride introduction tube be installed so as to open below the liquid level in the reactor. The pressure during the sulfonation period may normally be normal pressure to slightly reduced pressure, but from the viewpoint of the color tone of the produced polymer, it is particularly preferable to set the pressure inside the reactor to 50 to 700 mmHg@reduced pressure.

FIG. 1 is a schematic diagram of a reaction apparatus used in an example of the present invention. 1 is a polycondensation reactor, and a stirring blade 2 is rotated by a stirring motor. Further, 3 is a decompression line, which is connected to a vacuum pump. On the other hand, 4 is a glass container and 6 is fuming sulfuric acid with a specific gravity of about 1.86, which is heated in a hot water bath 5. The generated sulfuric anhydride is blown into the reaction solution through the pulp 7 and the ceramic-coated introduction tube 8.

(Function) It is well known that compounds having active hydrogen can be sulfonated with sulfuric anhydride, but when polyester is sulfonated with sulfuric anhydride, the reaction must be carried out under extremely mild conditions. If it is brought into contact with sulfuric anhydride in a molten state, it will carbonize.

However, in accordance with the present invention, when a molten polyester oligomer or polymer is contacted with sulfuric anhydride in the presence of a polymetallic siloxane compound.

The reason is not clear, but without causing carbonization.

Sulfonation becomes possible.

(Example) Next, the present invention will be specifically explained with reference to Examples.

In addition, in the examples, characteristic values etc. were measured as follows.

(1) Intrinsic viscosity [η] Measured at 20°C using an equal weight mixture of phenol and tetrachloroethane as a solvent.

(2) Melting point differential scanning calorimeter needle (DSC-1 manufactured by Perkin Elmer)
B).

(3) Degree of sulfonation The amount of S was determined using a fluorescent X-ray analyzer (Geigerflex 3604 M2 type, manufactured by Rigaku Denki Co., Ltd.).

(4) The drawn yarn with dyeability of 75d/36f is made into a tubular knitted fabric, and after boiling and scouring, washing with water, and drying, the basic dye Astrazone Blu is applied.
In the secondary dye bath using eFRR (manufactured by Bayer)
The dye was dyed at 100° C. for 60 minutes, and the dye concentration in the residual dye solution was measured to determine the dye exhaustion rate.

Dye concentration 5χowf Sodium acetate 0.2 g/It Acetic acid 0.2 mjl/g Bath ratio 1:50 Example Esterification reaction tank containing bis(β-hydroxyethyl) terephthalate and its low polymer (B) IET) A slurry of terephthalic acid and ethylene glycol (molar ratio 1:1.6) was continuously supplied to the reactor at 250°C and 0.
．． The reaction was carried out at 05 kg/ad G for a residence time of 8 hours to continuously obtain BHET with a reaction rate of 95%.

This BHET was charged into the polycondensation reactor of the reactor shown in Figure 1, and the polymetal siloxane compound shown in Table 1 and 2XIO-' mol of antimony dioxide/mol of acid component were added as a catalyst, and the pressure was gradually reduced. do.

Finally, polycondensation was performed at 0.1 mmHg to obtain a prepolymer [η] shown in Table 1.

Next, under a reduced pressure of 200 mmt (H), sulfuric anhydride was blown into the molten prepolymer at a ratio of 0.1 mol/mol acid component hour, and after contacting with stirring for 1 hour,
Polycondensation was carried out at 0.1 mmHg for 1 hour.

Table 1 shows the characteristic values of the obtained polyester and the dyeability of the yarn obtained by melt spinning and drawing by a conventional method.

In Table 1, the polymetallic siloxanes in Example 2 are diphenyldichlorosilane and Hou Chengwen &;! ; m (synthesized by reacting with hismagnesium in di-n-butyl ether at 5120°C for 12 hours (effects of the invention)) According to the present invention, by contacting polyester with sulfuric anhydride in the manufacturing process, simple It is possible to obtain a polyester that is uniformly and uniformly sulfonated, and to effectively produce a modified polyester that can be easily dyed with a basic dye.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a reaction apparatus used in two examples of the present invention. 1-Polycondensation reactor, 8.-Sulfuric anhydride inlet tube.

Claims (1)

[Claims] (1) When producing polyethylene terephthalate or a polyester mainly composed of polyethylene terephthalate, a method for producing a modified polyester characterized by bringing sulfuric anhydride into contact with a molten polyester oligomer or polymer in the presence of a polymetal siloxane compound. .