JPH07109062B2 - Oligomer removing agent and oligomer removing method - Google Patents

Description

The present invention relates to a removing agent for oligomers generated from polyester fibers and a method for removing oligomers.

"Prior Art" A polymer obtained by polymerizing 2 to 5 monomers constituting a polymer is usually called an oligomer. This is attached to the polymer molded product (for example, fiber) itself from the time of molding, or is generated by decomposition of the polymer in a treatment step for commercialization after molding. When the polymer molded product is treated in a dry state or a wet state, the oligomer is detached and attached to the processing equipment, or reattached to the polymer molded product itself like a resin to cause various obstacles.

Since polyester fibers, which are molded polyester, are often dyed in an acid bath during dyeing, oligomers are often generated due to hydrolysis of ester groups in the polyester fibers. It has various bad effects. For example, in the case of polyester fiber, this is the most frequently used high temperature dyeing method (for example, dyeing bath pH 4 to 5, dyeing temperature 125 to 135 ° C,
When dyeing with a disperse dye under conditions such as a dyeing time of 30 to 60 minutes)
% (Weight ratio) of oligomers (mainly trimers) are said to occur. Furthermore, it is empirically known that the generation rate of oligomers is affected by the concentration of disperse dyes, the presence or absence of a disperse dyeing agent at the time of dyeing, and the hardness of dyeing water. If adhered, problems such as uneven dyeing or damage to the texture of the dyed product are likely to occur. Further, the oligomer has a property of accumulating inside the dyeing machine (especially large accumulation in the heat exchanger part of the dyeing machine) when dyeing is repeated many times, and its removal is very difficult. There is also a tendency to increase the adhesion of oligomers generated from a leveling agent mainly composed of a polycyclic ester type nonionic surfactant, which is frequently used in dyeing polyester fibers, to fibers and dyeing machines.

The oligomer attached to the fiber or the dyeing machine cannot be removed with a reducing washing solution composed of an alkaline agent and a reducing agent, which is a post-treatment agent for dyeing polyester fiber, and dissolved by a special solvent such as 1,2-dichloroethane. There is no better way than removing it. Since this solvent is expensive and harmful to the human body, this method is difficult to adopt as an industrial method. As a method of removing the attached oligomer other than the above, there is a method of promoting the hydrolysis of the oligomer using a quaternary ammonium salt as a catalyst in the presence of an alkali such as sodium hydroxide. It is that it is gradually hydrolyzed and solubilized from the surface, and when the oligomer is attached thickly, a sufficient effect cannot be obtained. In this method, since the quaternary ammonium salt used as a catalyst is a cationic substance and remains in the dyeing machine, it may adversely affect the subsequent dyeing using an anionic substance. It's hard to say that it's a good way to remove it.

“Problems to be solved by the invention” In dyeing polyester fibers, it may cause uneven dyeing, impair the texture of the dyed product, etc. It has been desired to develop a method of preventing the adhesion or easily removing the oligomer attached to the polyester fiber, dyeing equipment and the like.

“Means for Solving Problems” The present inventors have achieved the present invention as a result of intensive studies to achieve the above-described object. That is, the present invention comprises an alkali metal salt of sulfonated lignin and / or a formalin condensate of cresol sulfonic acid having 0.15 to 0.4 of sulfonic acid groups per 1 of methoxy groups in the lignin molecule. Provided is a method for removing oligomers from polyester fibers, which comprises treating the dyed polyester fibers in a bath containing an oligomer removing agent for the polyester fibers and the metal salt.

The polyester fiber referred to in the present invention is, for example, a fiber made of polyethylene terephthalate, polybutylene terephthalate, a copolymer of polyethylene terephthalate and polyethylene isophthalate, or the like, an alkali weight reduction processed product thereof, an acid modified product or a product thereof. It may be a mixed fiber of polyester fiber and other kind of fiber.

Number of methoxy groups in the lignin molecule used in the present invention 1
On the other hand, sulfonated lignin having a number of sulfonic acid groups of 0.15 to 0.4 is called low sulfonated lignin, and its alkali metal salt is usually reacted with sulfonating agent under the conditions of alkaline and high temperature pressurization with sulfite pulp eluate. Manufactured.
At this time, the alkali metal salt of sulfonated lignin having a low degree of sulfonation as described above is obtained by adjusting the sulfonation conditions (reaction temperature, reaction time, amount of sulfonating agent).

On the other hand, a formalin condensate of cresol sulfonic acid is usually produced by sulfonating cresol and reacting it with an aqueous formaldehyde solution in the presence of Glauber's salt.

In these, the alkali metal salt is sodium salt,
Examples thereof include potassium salt and lithium salt, and sodium salt is usually used.

Next, an oligomer removal method using the alkali metal salt of low sulfonated lignin and / or the alkali metal salt of formalin condensate of cresol sulfonic acid (hereinafter referred to as oligomer remover) will be described. To remove the oligomer attached to the polyester fiber or dyeing equipment, 0.1 to 20 g of an oligomer removing agent, preferably 0.5
~ 5.0 g / containing a treatment bath in which the polyester fiber at 6.0 ~ 140 ℃, preferably 90 ~ 135 ℃ 10
For 60 minutes or in the case of dyeing equipment, the treatment bath prepared as described above may be added and treated under the same conditions as above. The treated polyester fiber and dyeing equipment need only be washed with water and do not require any special operation.

When calcium ions and magnesium ions are present in the treatment bath, the effect of the method of the present invention may be impaired, so a sequestering agent such as sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, or sodium polyacrylate should be used in combination. Is preferred.

EXAMPLES The present invention will be described more specifically by way of examples. In the examples, the "sulfonation degree" of sulfonated lignin means the average number of sulfonic acid groups when the number of methoxy groups in lignin is 1.

Example 1 Production of oligomer-attached dyed fabric Kayalon Polyester Black BX-SF paste 150 (Nippon Kayaku Co., Ltd.) with polyester processed yarn woven fabric wound in a stainless steel holder and having a bath ratio of 1:10 and pH = 5 (adjusted with acetic acid and sodium acetate) Company disperse dye) 1 in a dye bath containing 15% owf
Dyeing was carried out at 35 ° C. for 30 minutes and reduction washing was carried out to obtain a dyed polyester woven fabric with 0.41% (weight ratio) oligomer attached.

Oligomer removal test (Example of removal method) The polyester processed yarn woven fabric having 0.41% of the oligomer attached as described above is treated at 100 ° C. for 20 minutes in a treatment bath containing the following oligomer removing agent and chemicals (1 g / each) ( The bath ratio was 1:30) and the degree of oligomer removal was measured.

Example 2 The polyester textured yarn woven fabric to which the oligomer obtained in Example 1 is attached is water having a German hardness of 20 ° dH and a sulfonation degree of 0.18.
Was treated with a treatment bath consisting of 1 g of the sodium salt of sulfonated lignin and 1100 g of Kayachelator C-10001 at 100 ° C for 20 minutes. (Treatment bath 1:30) A polyester textured yarn fabric was obtained in which oligomers were completely removed.

"Effects of the Invention" Prevents adhesion of oligomers that cause uneven dyeing in dyeing of polyester fibers, impair the texture of dyed products, or make it difficult to clean dyeing equipment, and also adhere to polyester fibers, dyeing equipment, etc. It became possible to easily remove the oligomer.

Claims (2)

[Claims] 1. From an alkali metal salt of a sulfonated lignin and / or a formalin condensate of cresol sulfonic acid in which the number of sulfonic acid groups is 0.15 to 0.4 with respect to the number of methoxy groups in the lignin molecule is 1. Oligomer removal agent from polyester fiber. 2. An alkali metal salt of sulfonated lignin and / or an alkali metal salt of a formalin condensate of cresol sulfonic acid, in which the number of sulfonic acid groups is 0.15 to 0.4 per the number of methoxy groups in the lignin molecule. A method for removing oligomers from polyester fibers, which comprises treating the dyed polyester fibers in a bath containing the same.