DE112021001579T5 - Process for preparing a synthetic fiber treating agent, synthetic fiber treating agent, synthetic fibers and synthetic fiber manufacturing method - Google Patents

Abstract

The present invention addresses the problem of how to suitably suppress linting during a spinning process. This method for producing a treatment agent for synthetic fibers, wherein a boron content of the non-volatile portion of the treatment agent for synthetic fibers determined by ICP emission spectrometry is at most 200 ppm, has: an addition step in which a (poly)oxyalkylene derivative is prepared by an alkylene oxide is added to an alcohol in the presence of a catalyst containing a boron atom in each molecule, and a discharging step of discharging the catalyst so that the boron content of the non-volatile portion of the synthetic fiber treating agent is 200 or less as determined by ICP emission spectrometry ppm.

Description

TECHNICAL AREA

The present invention relates to a method for producing a synthetic fiber treating agent, a synthetic fiber treating agent, a synthetic fiber and a method for producing a synthetic fiber.

TECHNICAL BACKGROUND

Carbon fibers are produced, for example, by performing a spinning step in which an acrylic resin is spun into fibers to produce a carbon fiber precursor formed as synthetic fibers, and a heat treatment step in which the synthetic fibers are subjected to heat treatment.

In Patent Document 1, there is disclosed an acrylic fiber treatment agent containing an amino-modified silicone and a polyoxyalkylene alkyl ether.

PRIOR ART DOCUMENTS

PATENT DOCUMENTS

Patent Document 1: International Reference WO 2017/169632

OVERVIEW OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

In the spinning step, fuzzing of the fibers may occur; avoidance of fuzz in the spinning step is an object.

The present invention has been made in view of these circumstances, and an object of the invention is to provide a method for producing a treating agent for synthetic fibers, by which generation of lint in the spinning step can be suitably avoided. Another object of the invention is to provide a synthetic fiber treating agent by which fuzz can be suitably avoided in the spinning step, a synthetic fiber to which the synthetic fiber treating agent is adhered, and a method for producing a synthetic fiber using the treating agent provide for synthetic fibers.

MEANS OF SOLVING THE PROBLEMS

A method for producing a synthetic fiber treatment agent to solve the above problem is that a synthetic fiber treatment agent is prepared in which a boron content of the non-volatile portion of the synthetic fiber treatment agent determined by ICP emission spectrometry is at most 200 ppm ; the method comprises an addition step in which an alkylene oxide is added to an alcohol in the presence of a catalyst whose molecule contains a boron atom to obtain a (poly)oxyalkylene derivative, and a removal step in which the catalyst is removed so that the boron content of the non-volatile fraction of the synthetic fiber treatment composition, as determined by ICP emission spectrometry, does not exceed 200 ppm.

In the process for producing a synthetic fiber treating agent, in the discharging step, the catalyst is preferably discharged so that the boron content of the non-volatile portion of the synthetic fiber treating agent is at most 40 ppm as determined by ICP emission spectrometry.

In the process for producing a treating agent for synthetic fibers, the (poly)oxyalkylene derivative preferably has a composition in which an alkylene oxide having 2 to 4 carbon atoms is added in a total ratio of 1 to 30 moles to 1 mole of alcohol.

In the process for producing a synthetic fiber treating agent, the alcohol is preferably an alcohol containing an alkyl chain having 10 to 18 carbon atoms in its molecule.

In the process for producing a synthetic fiber treating agent, the alcohol is preferably an alcohol containing an alkyl chain having 12 to 16 carbon atoms in its molecule.

In the process for producing a synthetic fiber treating agent, the alcohol is preferably a monohydric aliphatic alcohol having a hydroxy group at a β-position of an alkyl chain.

In the method for producing a synthetic fiber treating agent, the method preferably has a mixing step in which a sizing agent is mixed.

In the method for producing a synthetic fiber treating agent, the sizing agent preferably comprises silicone.

In the process for producing a synthetic fiber treating agent, the sizing agent preferably comprises an amino-modified silicone.

In the method for producing a treating agent for synthetic fibers, the smoothing agent is preferably mixed in the mixing step such that - when the sum of the content of the (poly)oxyalkylene derivative and the smoothing agent is calculated as 100 parts by mass - the proportion of the (poly)oxyalkylene derivative is 10 to is 70 parts by weight and the proportion of the smoothing agent is 90 to 30 parts by weight.

In the method for producing a synthetic fiber treating agent, the synthetic fiber is preferably a carbon fiber precursor.

A synthetic fiber treating agent for solving the above problem comprises a sizing agent and a (poly)oxyalkylene derivative, and the boron content of the non-volatile portion of the treating agent is at most 200 ppm by ICP emission spectrometry.

In the synthetic fiber treating agent, the boron content is preferably at most 40 ppm.

In the synthetic fiber treating agent, the (poly)oxyalkylene derivative preferably has a composition in which an alkylene oxide having 2 to 4 carbon atoms is added in a ratio of 1 to 30 moles in total to 1 mole of alcohol.

In the synthetic fiber treating agent, the alcohol preferably has an alkyl chain having 10 to 18 carbon atoms in its molecule.

In the synthetic fiber treating agent, the alcohol preferably has an alkyl chain having 12 to 16 carbon atoms in its molecule.

In the synthetic fiber treating agent, the alcohol is preferably a monohydric aliphatic alcohol having a hydroxy group at a β-position of an alkyl chain.

In the synthetic fiber treating agent, the slickening agent preferably comprises an amino-modified silicone.

In the treating agent for synthetic fibers, when the sum of the content of the (poly)oxyalkylene derivative and the smoothing agent is calculated as 100 parts by mass, the proportion of the (poly)oxyalkylene derivative is 10 to 70 parts by mass and the proportion of the smoothing agent is 90 to 30 parts by mass.

In the synthetic fiber treating agent, the synthetic fiber is preferably a carbon fiber precursor.

A synthetic fiber for solving the above problem is a synthetic fiber to which the synthetic fiber treating agent is adhered.

A method for producing a synthetic fiber to solve the above problem comprises adhering the synthetic fiber treating agent to fibers.

EFFECTS OF THE INVENTION

The present invention succeeds in suitably avoiding lint formation occurring in a spinning step.

character list

• the 1 Fig. 12 is a schematic view of an apparatus for measuring a smoothness.

MODES FOR CARRYING OUT THE INVENTION

(First embodiment)

In the following, a first exemplary embodiment is described, which is designed as a treatment agent for synthetic fibers (hereinafter also simply referred to as treatment agent) according to the invention.

The treating agent according to the present embodiment includes a smoothing agent and a (poly)oxyalkylene derivative. In the case of the treatment agent, a boron content of the non-volatile component of the treatment agent, determined by means of ICP emission spectrometry, is at most 200 ppm. Since the boron content in the treating agent is at most 200 ppm, generation of lint in a spinning step can be suitably avoided.

The boron content of the non-volatile component of the treatment agent, detected by means of ICP emission spectrometry, is preferably at most 40 ppm and particularly preferably at most 15 ppm. With the boron content being at most 40 ppm, fuzzing in a spinning step can be prevented more suitably.

The boron content of the non-volatile component of the treatment agent detected by means of ICP emission spectrometry can also be, for example, at least 0.1 ppm, at least 0.6 ppm, at least 0.9 ppm or at least 2 ppm.

In the aspects of the (poly)oxyalkylene derivative, there are a compound in which an alkylene oxide is added to an alcohol or a carboxylic acid, and an ether/ester compound in which an alkylene oxide is added to an ester compound of a carboxylic acid and a polyhydric alcohol. The alcohol or carboxylic acid may be an aliphatic-based alcohol or aliphatic-based carboxylic acid having a straight chain or a branched chain, or may be an aromatic-based alcohol or aromatic-based carboxylic acid. Alternatively, he/she may be a saturated alcohol or carboxylic acid, or an unsaturated alcohol or carboxylic acid. Alternatively, it may be an alcohol or a carboxylic acid which is monohydric or dihydric or more.

Specific embodiments of the (poly)oxyalkylene derivative include a compound in which 12 moles of ethylene oxide is added to 1 mole of 2-dodecanol, a compound in which 9 moles of ethylene oxide is added to 1 mole of 2-tetradecanol, a compound in which 5 moles of ethylene oxide are added to 1 mole of 2-dodecanol, a compound in which 9 moles of ethylene oxide are added to 1 mole of 2-dodecanol, a compound in which 30 moles of ethylene oxide are added to 1 mole of 2-dodecanol, a compound in which 9 moles of ethylene oxide are added to 1 mole of 2-tridecanol, a compound where 12 moles of ethylene oxide are added to 1 mole of 2-tridecanol, a compound where 9 moles of ethylene oxide are added to 1 mole of 2-decanol, a compound where 9 moles of ethylene oxide are added to 1 mole of 2-octadecanol, a compound where 5 moles of ethylene oxide are added to 1 mole of 2-nonanol, a compound where 7 moles of ethylene oxide are added to 1 mole of 4-dodecanol, a compound in which 25 moles of ethylene oxide are added to 1 mole of 1-tetradecanol, a compound in which 5 moles of ethylene oxide are added to 1 mole of 2-pentadecanol, a compound in which 7 moles of ethylene oxide are added to 1 mole of 1-octanol, a compound in which 20 moles of ethylene oxide is added to 1 mole of 1-nonanol, a compound in which 9 moles of ethylene oxide is added to 1 mole of 1-dodecanol, and a compound in which 5 moles of ethylene oxide is added to 1 mole of 2-dodecanol will.

One type of the (poly)oxyalkylene derivative can be used alone, or two or more types of the (poly)oxyalkylene derivative can be used in combination.

For the (poly)oxyalkylene derivative, there is no particular limitation on a number of moles of an alkylene oxide having 2 to 4 carbon atoms added relative to 1 mole of an alcohol; preferably, it has a composition in which an alkylene oxide having 2 to 4 carbon atoms is added in a total ratio of 1 to 30 moles to 1 mole of an alcohol.

The alcohol preferably has an alkyl chain having 10 to 18 carbon atoms in its molecule, more preferably it has an alkyl chain having 12 to 16 carbon atoms in its molecule.

The alcohol is preferably a monohydric aliphatic alcohol having a hydroxy group at a β-position of an alkyl chain. The monohydric aliphatic alcohol may be saturated aliphatic alcohol or unsaturated aliphatic alcohol. Alternatively, the monohydric aliphatic alcohol may be a straight chain aliphatic alcohol or a branched chain aliphatic alcohol.

As described below, by using the monohydric aliphatic alcohol having the hydroxy group at the β-position of the alkyl chain, a wetting property of the treating agent with respect to a synthetic fiber is improved.

Specific forms of the alkylene oxide having 2 to 4 carbon atoms are ethylene oxide, propylene oxide and butylene oxide. Of these, ethylene oxide is preferred. The polymerization sequence is not particularly limited and may be block adduct or random adduct.

Forms of the smoothing agent contained in the treating agent according to the present embodiment may be a silicone and an ester.

There are no particular restrictions on the silicone used as the smoothing agent; Examples are dimethyl silicone, phenyl modified silicone, amino modified silicone, amide modified silicone, polyether modified silicone, aminopolyether modified silicone, alkyl modified silicone, alkyl aralkyl modified silicone, alkyl polyether modified silicone, ester -modified silicone, epoxy-modified silicone, carbinol-modified silicone and mercapto-modified silicone.

Of the above substances, an amino-modified silicone is preferably contained.

Because the smoothing agent has an amino-modified silicone, the smoothness of the treatment agent is improved—as described below.

There are no particular restrictions on the ester used as a smoothing agent; Examples thereof are (1) an ester compound of an aliphatic monoalcohol and an aliphatic monocarboxylic acid such as octyl palmitate, oleyl laurate, oleyl oleate and isotetracosyl oleate, (2) an ester compound of an aliphatic polyhydric alcohol and an aliphatic monocarboxylic acid such as 1, 6-hexanediol didecanoate, glycerol trioleate, trimethylolpropane trilaurate and pentaerythritol tetraoctanoate, (3) an ester compound of an aliphatic monoalcohol and an aliphatic polycarboxylic acid such as dioleyl azelate, dioleyl thiodipropionate, diisocetyl thiodipropionate and diisostearyl thiodipropionate, (4) an ester compound of an aromatic monoalcohol and an aliphatic monocarboxylic acid such as benzyl oleate and benzyl laurate, (5) a full ester compound of an aromatic polyhydric alcohol and an aliphatic monocarboxylic acid such as bisphenol A dilaurate and the dilaurate of an alkyl noxide adduct of bisphenol A, (6) a full ester compound of an aliphatic monoalcohol and an aromatic polycarboxylic acid such as bis-2-ethylhexyl phthalate, diisostearyl isophthalate and trioctyl trimellitate, and (7) natural oils and fats such as coconut oil , canola oil, sunflower oil, soybean oil, castor oil, sesame oil, fish oil and beef tallow. It is also possible to use a known sizing agent incorporated in synthetic fiber treating agents.

Specific embodiments of the smoothing agent are: an amino-modified silicone with a kinematic viscosity of 650 mm ² /s at 25°C and an amine equivalent weight of 1,800 g/mol, an amino-modified silicone with a kinematic viscosity of 90 mm ² /s 25°C and an amine equivalent weight of 5,000 g/mol, an amino-modified silicone with a kinematic viscosity of 4,500 mm ² /s at 25°C and an amine equivalent weight of 1200 g/mol, an amino-modified silicone with a kinematic viscosity of 40 mm ² /s at 25°C and an amine equivalent weight of 1800 g/mol, an amino-modified silicone with a kinematic viscosity of 8,000 mm ² /s at 25°C and an amine equivalent weight of 1,000 g/mole, a polyether-modified silicone with a kinematic viscosity of 500 mm ² /s at 25°C and with ethylene oxide / propylene oxide = 100/0 and a mass fraction of silicone/polyether = 50/50, a polyether-modified silicone with a kinematic viscosity of 1,700 mm ² /s at 25°C and with ethylene oxide/propylene oxide = 40/60 and a mass fraction of silicone/polyether = 20/80 dimethylsilicone with a kinematic viscosity of 10,000 mm ² /s at 25°C, thiodipropionic acid di(n-dodecyl) ester and a dilauryl ester of a 2 mole ethylene oxide adduct of bisphenol A.

One type of the smoothing agent can be used alone, or two or more types of the smoothing agent can be used in combination.

The content of (poly)oxyalkylene derivative or smoothing agent is not restricted. When the sum of the content of the (poly)oxyalkylene derivative and the smoothing agent is calculated as 100 parts by mass, the treating agent preferably contains the (poly)oxyalkylene derivative in a ratio of 10 to 70 parts by mass and the smoothing agent in a ratio of 90 to 30 parts by mass. More preferably, the treatment agent contains the (poly)oxyalkylene derivative in a proportion of 20 to 60 parts by mass and the smoothing agent in a proportion of 80 to 40 parts by mass.

(Second embodiment)

A second embodiment embodied as a method for manufacturing a treating agent according to the present invention will now be described. Above all, differences from the first embodiment will be described.

The process for preparing a treating agent has an addition step in which, in the presence of a catalyst containing a boron atom in its molecule, the alkylene oxide is added to the alcohol to obtain the (poly)oxyalkylene derivative, and a removal step in which the Catalyst is removed so that the boron content of the non-volatile fraction of the treatment agent determined by ICP spectrometry is at most 200 ppm.

There are no particular restrictions on the catalyst having a boron atom in its molecule; this may be an acid catalyst such as boron trifluoride or a complex thereof.

Illustrative of the addition step, a small number of moles, e.g. 1 to 5 moles, of ethylene oxide is caused to react with the alcohol using an acid catalyst, e.g. Next, the ethylene oxide is caused to react with the recovered low mole ethoxylate compound in the presence of an alkaline catalyst such as sodium hydroxide, potassium hydroxide or sodium alkoxide, after which the catalyst is taken out.

The process for taking out the catalyst from a liquid subjected to the addition step is not particularly limited, and a known process can be used. Examples of a process for taking out the catalyst include a process using silica to filter the liquid and separating the catalyst, and a process using a synthetic inorganic adsorbent to adsorb and remove the catalyst from the to remove liquid.

For example, ICP emission spectrometry can be performed by the following processes: First, solutions having known boron concentrations (e.g., a 0.5 ppm solution and a 1 ppm solution) are prepared in advance and treated with an ICP emission spectrometer to create a calibration curve. Next, the treating agent which has already undergone the extraction step is measured with the ICP emission spectrometer, and the boron content present in the non-volatile portion of the treating agent is measured from the calibration curve previously prepared.

The method for producing a treating agent according to the present embodiment preferably has a mixing step in which the smoothing agent is preferably mixed with the (poly)oxyalkyl lenderivat is mixed in order to achieve the content of (poly)oxyalkylene derivative and smoothing agent specified for the first exemplary embodiment.

(Third embodiment)

A third exemplary embodiment, which is designed as a synthetic fiber according to the invention, will now be described below. To the synthetic fiber according to the present embodiment, the treating agent according to the first embodiment adheres. There are no particular restrictions on the synthetic fiber, and specific examples thereof are: (1) polyethylene terephthalate, polypropylene terephthalate, polylactic acid ester and other polyester fibers, (2) nylon 6, nylon 66 and other polyamide fibers, (3) polyacrylic, modacrylic - and other polyacrylic fibres, (4) polyethylene, polypropylene and other polyolefin fibres, (5) cellulose fibers and (6) lignin fibres. As for the synthetic fibers, a carbon fiber precursor produced from lignin fibers, which is made of a resin and turns into carbon fibers by undergoing a carbonization step described later, is preferable. There are no particular restrictions on the resin constituting the carbon fiber precursor, and specific examples thereof are: acrylic resin, polyethylene resin, phenolic resin, cellulose resin, lignin resin and pitch.

There is no particular limitation on the amount of the treating agent to be adhered to the synthetic fiber according to the first embodiment, and the treating agent (except for a solvent) is adhered so that its mass fraction relative to the synthetic fiber is preferably 0.1% to 2%. is, particularly preferably 0.3% to 1.2%.

(Fourth embodiment)

A fourth embodiment of a method for producing a synthetic fiber according to the present invention will now be described below. The method for manufacturing a synthetic fiber according to the present embodiment includes adhering the treating agent of the first embodiment to a fiber.

Examples of formation of the treating agent in the first embodiment, wherein the treating agent is adhered to a fiber, include an organic solvent solution and an aqueous solution.

The method for adhering the treating agent to the synthetic fiber may be a method using, for example, an aqueous solution containing the treating agent of the first embodiment and water, or another diluted aqueous solution for adhering by a known process such as a dipping process, a spraying process, a rolling process or a method of oil lubrication of a guide using a metering pump.

A method for manufacturing a carbon fiber using the synthetic fiber according to the present embodiment will now be described below.

The method for producing a carbon fiber preferably has the following steps 1 to 3:

Step 1: a spinning step in which the synthetic fibers are spun and the treating agent according to the first embodiment is adhered to the synthetic fiber.

Step 2: a fireproofing treatment step in which the synthetic fiber obtained in Step 1 is converted into a flame retardant fiber in an oxidizing atmosphere at 200°C to 300°C, preferably 230°C to 270°C.

Step 3: a carbonization step in which the flame retardant fiber obtained in Step 2 is carbonized in an inert atmosphere at 300°C to 2000°C, preferably 300°C to 1300°C.

It is assumed that one heat treatment step is composed of steps 2 and 3 described above.

Preferably, the spinning step further includes a wet spinning step in which a resin is dissolved in a solvent and spun into a fiber, a drying and compacting step in which the wet-spun synthetic fiber is dried and compacted, and a drawing step in which the dried and compressed synthetic fiber is stretched.

While there is no particular limitation on a temperature in the drying and densification step, the synthetic fiber after passing through the wet spinning step is preferably heated, for example, at 70°C to 200°C. While a timing at which the treating agent is attached to the synthetic fiber is not particularly limited, such timing is preferably between the wet spinning step and the drying and compacting step.

There are no particular restrictions on the oxidizing atmosphere in the fireproof treatment step; it can be, for example, an air atmosphere.

There are no particular restrictions on the inert atmosphere in the carbonization step; it may be, for example, a nitrogen atmosphere, an argon atmosphere, or a vacuum atmosphere.

• (1) Das Behandlungsmittel gemäß den Ausführungsbeispielen weist das Glättmittel und das (Poly)oxyalkylenderivat auf; der mittels ICP-Emissions-Spektrometrie ermittelte Borgehalt des nichtflüchtigen Anteils des Behandlungsmittels weist einen spezifizierten Wert auf. Dadurch kann eine Fusselbildung von Fasern, die den Spinnschritt durchlaufen haben, vermieden werden. Außerdem kann eine Glätte der Fasern, die den Spinnschritt durchlaufen haben, verbessert werden. Ferner kann eine Bündelungseigenschaft der schwer entflammbaren Fasern, die den Brandschutzbehandlungsschritt durchlaufen haben, verbessert werden.
• (2) Mittels des Behandlungsmittels gemäß den Ausführungsbeispielen wird eine Benetzungseigenschaft in Bezug auf die synthetische Faser verbessert, wodurch das Behandlungsmittel gleichmäßiger an den synthetischen Fasern anhaften kann.
• (3) Das Behandlungsmittel wird zwischen dem Nassspinnschritt und dem Trocknungs- und Verdichtungsschritt an einer synthetischen Faser angehaftet. Daher kann eine Fusselbildung besonders vorteilhaft innerhalb des Spinnschritts in dem Trocknungs- und Verdichtungsschritt vermieden werden.

The following effects can be obtained by means of the treatment agent, by means of the method for producing the treatment agent, by means of the synthetic fiber and by means of the method for production of the synthetic fiber according to the exemplary embodiments:

• (1) The treating agent according to the working examples comprises the smoothing agent and the (poly)oxyalkylene derivative; the boron content of the non-volatile portion of the treatment agent, determined by ICP emission spectrometry, has a specified value. This can prevent fuzzing of fibers that have gone through the spinning step. In addition, a smoothness of the fibers that have undergone the spinning step can be improved. Further, a bundling property of the flame retardant fibers that have undergone the fireproof treatment step can be improved.
• (2) By using the treating agent according to the embodiments, a wetting property with respect to the synthetic fiber is improved, thereby allowing the treating agent to adhere to the synthetic fibers more uniformly.
• (3) The treating agent is attached to a synthetic fiber between the wet spinning step and the drying and compacting step. Therefore, lint formation can be avoided particularly advantageously within the spinning step in the drying and compacting step.

The embodiments described above can be modified as follows. The exemplary embodiments described above and the following modifications can be combined with one another within a technically consistent context.

In the embodiments, the taking-out step in which the catalyst having a boron atom is taken out may be carried out immediately after the addition step, in the middle of the addition step, or after mixing another ingredient.

In the embodiments, the synthetic fiber may be, for example, a fiber on which the heat treatment step is not performed.

Furthermore, stabilizers, antistatic agents, electrostatic inhibitors, binders, antioxidants, ultraviolet absorbers and other ingredients that are commonly used with treating agents or aqueous solutions to ensure quality of the treating agents or aqueous solutions, to the treating agent or to the aqueous solution according to the Embodiments are mixed, as far as this does not affect the effects of the present invention.

EXAMPLES

Now, examples are given below to describe in detail the features and effects of the present invention, but the present invention is not limited to these examples. In the following description of examples and comparative examples, “parts” should be understood to mean proportions by mass and “%” should be understood to mean percentages by mass.

Experimental Part 1 (Preparation of Synthetic Fiber Treatment Agents)

(Example 1)

First, in the addition step, 186 parts of 2-dodecanol and 0.5 part of boron trifluoride were charged into an autoclave; after the atmosphere was replaced with nitrogen gas, 132 parts of ethylene oxide was gradually added at 150°C to conduct etherification.

Next, to the liquid in which etherification had taken place, 5 parts of anion exchange resin was added in the catalyst-discharging step, and stirred at room temperature for 30 minutes. Thereafter, the liquid was transferred to a filter precoated with silica, and the anion exchange resin which had absorbed the boron trifluoride catalyst was removed to obtain an adduct of 2-dodecanol containing 3 moles of ethylene oxide.

Further, 318 parts of the obtained 2-dodecanol adduct containing 3 moles of ethylene oxide and 0.5 part of sodium hydroxide were charged into an autoclave; after the atmosphere was replaced with nitrogen gas, 396 parts of ethylene oxide was gradually added at 150°C to conduct etherification.

Furthermore, to the liquid in which etherification had taken place, 10 parts of a synthetic inorganic adsorbent was added and stirred at 80°C for 30 minutes. Thereafter, the liquid was transferred to a filter pre-coated with silica, and the synthetic inorganic adsorbent which had adsorbed the sodium hydroxide catalyst was removed to obtain a (poly)oxyalkylene derivative (A-1) (see Table 1).

The respective ingredients listed in Table 1 were put into a beaker for use in such a manner that the mixing ratio was 30 parts of (poly)oxyalkylene derivative (A-1) and 70 parts of smoothing agent (B-1). These were mixed well by stirring. With continued stirring, ion-exchanged water was gradually added to make the solid concentration 25%, thereby preparing a 25% aqueous solution of a synthetic fiber treating agent according to Example 1.

(Examples 2 to 23 and Comparative Examples 1 to 3)

Using the respective ingredients listed in Table 1 and following the procedures of Example 1, respective treating agents for synthetic fibers as Examples 2 to 23 and Comparative Examples 1 to 4 were prepared.

In the columns "(A) (poly)oxyalkylene derivative", "(B) smoothing agent" and "boron content in the treatment agent (ppm)" of Table 1, the type and proportion of the (poly)oxyalkylene derivative, type and Proportion of the smoothing agent and the boron content of the treatment agent specified. [Table 1] (A) (Poly)oxyalkylene derivative (B) Smoothing agent Boron content in treatment agent (ppm) Evaluation symbol mass fractions symbol mass fractions Spinning Lint Flame retardant fibers - bundling property smoothness wetting property example 1 A-1 30 B-1 70 0.9 ○○○ ○○ ○○○ ○○ example 2 A-1 30 B-2 70 0.9 ○○○ ○○ ○○○ ○○ Example 3 A-1 A-1 30 30 B-3 70 0.9 ○○○ ○○ ○○○ ○○ example 4 B-4 70 0.9 ○○○ ○○ ○○○ ○○ Example 5 A-2 65 B-2 35 2.6 ○○○ ○○ ○○○ ○○ Example 6 A-3 20 B-3 80 0.6 ○○○ ○○ ○○○ ○○ Example 7 A-4 30 B-4 70 2.7 ○○○ ○○ ○○○ ○○ example 8 A-5 35 B-5 65 3.2 ○○○ ○○ ○○○ ○○ example 9 A-6 60 B-1 40 13 ○○○ ○○ ○○○ ○○ Example 10 A-7 10 B-1 90 0.1 ○○○ ○○ ○○○ ○○ Example 11 A-2 50 B-1 B-2 25 25 2 ○○○ ○○ ○○○ ○○ Example 12 A-1 30 B-6 70 0.9 ○○○ ○○ ○○ ○○ Example 13 A-1 30 B-7 70 0.9 ○○○ ○○ ○○ ○○ Example 14 A-1 30 B-8 70 0.9 ○○○ ○○ ○○ ○○ Example 15 A-1 30 B-9 70 0.9 ○○○ ○○ ○ ○○ Example 16 A-1 30 B-10 70 0.9 ○○○ ○○ ○ ○○ Example 17 A-8 30 B-1 70 2.7 ○○ ○○ ○○○ ○○ Example 18 A-9 30 B-1 70 2.4 ○○ ○○ ○○○ ○○ Example 19 A-10 30 B-1 70 2.7 ○○ ○ ○○○ ○○ Example 20 A-11 30 B-1 70 3.6 ○○ ○○ ○○○ ○ Example 21 A-12 30 B-9 70 2.7 ○○ ○○ ○ ○ Example 22 A-13 30 B-1 70 65 ○ ○○ ○ ○○ Example 23 A-14 40 B-10 60 78 ○ ○ ○ ○ Comparative example 1 a-1 30 B-9 70 396 × × × × Comparative example 2 a-2 30 B-9 70 464 × ○ × × Comparative example 3 a-3 30 B-10 70 430 × ○ × ○

• ((Poly)oxyalkylenderivate)
  • A-1: Verbindung, bei der 12 Mol Ethylenoxid zu 1 Mol 2-Dodecanol hinzugefügt wurden
  • A-2: Verbindung, bei der 9 Mol Ethylenoxid zu 1 Mol 2-Tetradecanol hinzugefügt wurden
  • A-3: Verbindung, bei der 5 Mol Ethylenoxid zu 1 Mol 2-Dodecanol hinzugefügt wurden
  • A-4: Verbindung, bei der 9 Mol Ethylenoxid zu 1 Mol 2-Dodecanol hinzugefügt wurden
  • A-5: Verbindung, bei der 30 Mol Ethylenoxid zu 1 Mol 2-Dodecanol hinzugefügt wurden
  • A-6: Verbindung, bei der 9 Mol Ethylenoxid zu 1 Mol 2-Tridecanol hinzugefügt wurden
  • A-7: Verbindung, bei der 12 Mol Ethylenoxid zu 1 Mol 2-Tridecanol hinzugefügt wurden
  • A-8: Verbindung, bei der 9 Mol Ethylenoxid zu 1 Mol 2-Decanol hinzugefügt wurden
  • A-9: Verbindung, bei der 9 Mol Ethylenoxid zu 1 Mol 2-Octadecanol hinzugefügt wurden
  • A-10: Verbindung, bei der 5 Mol Ethylenoxid zu 1 Mol 2-Nonanol hinzugefügt wurden
  • A-11: Verbindung, bei der 7 Mol Ethylenoxid zu 1 Mol 4-Dodecanol hinzugefügt wurden
  • A-12: Verbindung, bei der 25 Mol Ethylenoxid zu 1 Mol 1-Tetradecanol hinzugefügt wurden
  • A-13: Verbindung, bei der 5 Mol Ethylenoxid zu 1 Mol 2-Pentadecanol hinzugefügt wurden
  • A-14: Verbindung, bei der 7 Mol Ethylenoxid zu 1 Mol 1-Octanol hinzugefügt wurden
    • a-1: Verbindung, bei der 20 Mol Ethylenoxid zu 1 Mol 1-Nonanol hinzugefügt wurden
    • a-2: Verbindung, bei der 9 Mol Ethylenoxid zu 1 Mol 1-Dodecanol hinzugefügt wurden
    • a-3: Verbindung, bei der 5 Mol Ethylenoxid zu 1 Mol 2-Dodecanol hinzugefügt wurden

Details regarding the respective ingredients A-1 to A-14 and B1 to B10 listed in the "Symbol" columns of Table 1 are as follows:

• ((poly)oxyalkylene derivatives)
  • A-1: Compound in which 12 moles of ethylene oxide was added to 1 mole of 2-dodecanol
  • A-2: Compound in which 9 moles of ethylene oxide is added to 1 mole of 2-tetradecanol
  • A-3: Compound in which 5 moles of ethylene oxide is added to 1 mole of 2-dodecanol
  • A-4: Compound in which 9 moles of ethylene oxide is added to 1 mole of 2-dodecanol
  • A-5: Compound in which 30 moles of ethylene oxide is added to 1 mole of 2-dodecanol
  • A-6: Compound in which 9 moles of ethylene oxide is added to 1 mole of 2-tridecanol
  • A-7: Compound in which 12 moles of ethylene oxide was added to 1 mole of 2-tridecanol
  • A-8: Compound in which 9 moles of ethylene oxide is added to 1 mole of 2-decanol
  • A-9: Compound in which 9 moles of ethylene oxide is added to 1 mole of 2-octadecanol
  • A-10: Compound in which 5 moles of ethylene oxide was added to 1 mole of 2-nonanol
  • A-11: Compound in which 7 moles of ethylene oxide is added to 1 mole of 4-dodecanol
  • A-12: Compound in which 25 moles of ethylene oxide is added to 1 mole of 1-tetradecanol
  • A-13: Compound in which 5 moles of ethylene oxide is added to 1 mole of 2-pentadecanol
  • A-14: Compound in which 7 moles of ethylene oxide is added to 1 mole of 1-octanol
    • a-1: Compound in which 20 moles of ethylene oxide was added to 1 mole of 1-nonanol
    • a-2: Compound in which 9 moles of ethylene oxide was added to 1 mole of 1-dodecanol
    • a-3: Compound in which 5 moles of ethylene oxide was added to 1 mole of 2-dodecanol

The type of (poly)oxyalkylene derivative used, the number of carbon atoms of the alcohol, the position of the hydroxy group in the alkyl chain and the boron content of the (poly)oxyalkylene derivative are given for each of the above (poly)oxyalkylene derivatives in columns "(A) (poly)oxyalkylene derivative”, “Number of carbon atoms of monohydric aliphatic alcohol”, “position of hydroxy group” and “boron content (ppm)” of Table 2. [Table 2] symbol (A) (Poly)oxyalkylene derivative Number of carbon atoms of the monohydric aliphatic alcohol position of the hydroxy group boron content (ppm) A-1 Compound in which 12 moles of ethylene oxide are added to 1 mole of 2-dodecanol 12 β position 3 A-2 Compound in which 9 moles of ethylene oxide have been added to 1 mole of 2-tetradecanol 14 β position 4 A-3 Compound in which 5 moles of ethylene oxide have been added to 1 mole of 2-dodecanol 12 β position 3 A-4 Compound in which 9 moles of ethylene oxide have been added to 1 mole of 2-dodecanol 12 β position 9 A-5 Compound in which 30 moles of ethylene oxide is added to 1 mole of 2-dodecanol 12 β position 9 A-6 Compound in which 9 moles of ethylene oxide are added to 1 mole of 2-tridecanol 13 β position 21 A-7 Compound in which 12 moles of ethylene oxide are added to 1 mole of 2-tridecanol 13 β position 1 A-8 Compound in which 9 moles of ethylene oxide are added to 1 mole of 2-decanol 10 β position 9 A-9 Compound in which 9 moles of ethylene oxide are added to 1 mole of 2-octadecanol 18 β position 8th A-10 Compound in which 5 moles of ethylene oxide have been added to 1 mole of 2-nonanol 9 β position 9 A-11 Compound in which 7 moles of ethylene oxide have been added to 1 mole of 4-dodecanol 12 δ position 12 A-12 Compound in which 25 moles of ethylene oxide have been added to 1 mole of 1-tetradecanol 14 α position 9 A-13 Compound in which 5 moles of ethylene oxide have been added to 1 mole of 2-pentadecanol 15 β position 216 A-14 Compound in which 7 moles of ethylene oxide have been added to 1 mole of 1-octanol 8th α position 194 a-1 Compound in which 20 moles of ethylene oxide is added to 1 mole of 1-nonanol 9 α position 1320 a-2 Compound in which 9 moles of ethylene oxide are added to 1 mole of 1-dodecanol 12 α position 1547 a-3 Compound in which 5 moles of ethylene oxide have been added to 1 mole of 2-dodecanol 12 β position 1432

In Table 2, the differences in the boron contents of the respective (poly)oxyalkylene derivatives are based on differences in the time for which the anionic exchange resin having adsorbed the boron trifluoride catalyst by the silica precoated filter was removed in the above-described catalyst removal step . That is, the longer the period of time in which the anionic exchange resin which had adsorbed the boron trifluoride catalyst by the silica precoated filter was removed, the lower the boron content in the (poly)oxyalkylene derivative.

• B-1: amino-modifiziertes Silikon mit einer kinematischen Viskosität von 650 mm²/s bei 25°C und einem Aminäquivalentgewicht von 1.800 g/Mol
• B-2: amino-modifiziertes Silikon mit einer kinematischen Viskosität von 90 mm²/s bei 25°C und einem Aminäquivalentgewicht von 5.000 g/Mol
• B-3: amino-modifiziertes Silikon mit einer kinematischen Viskosität von 4.500 mm²/s bei 25°C und einem Aminäquivalentgewicht von 1.200 g/Mol
• B-4: amino-modifiziertes Silikon mit einer kinematischen Viskosität von 40 mm²/s bei 25°C und einem Aminäquivalentgewicht von 1.800 g/Mol
• B-5: amino-modifiziertes Silikon mit einer kinematischen Viskosität von 8.000 mm²/s bei 25°C und einem Aminäquivalentgewicht von 1.000 g/Mol
• B-6: polyether-modifiziertes Silikon mit einer kinematischen Viskosität von 500 mm²/s bei 25°C und mit Ethylenoxid / Propylenoxid = 100/0 und einem Massenverhältnis Silikon / Polyether = 50/50
• B-7: polyether-modifiziertes Silikon mit einer kinematischen Viskosität von 1.700 mm²/s bei 25°C und mit Ethylenoxid / Propylenoxid = 40/60 und einem Massenverhältnis Silikon / Polyether = 20/80
• B-8: Dimethylsilikon mit einer kinematischen Viskosität von 10.000 mm²/s bei 25°C
• B-9: Thiodipropionsäure-Di(n-dodecyl)ester
• B-10: Dilaurylester eines 2 Mol Ethylenoxid enthaltenden Addukts von Bisphenol A

(smoothing agent)

• B-1: Amino-modified silicone with a kinematic viscosity of 650 mm ² /s at 25°C and an amine equivalent weight of 1800 g/mol
• B-2: Amino-modified silicone with a kinematic viscosity of 90 mm ² /s at 25°C and an amine equivalent weight of 5,000 g/mol
• B-3: Amino-modified silicone with a kinematic viscosity of 4500 mm ² /s at 25°C and an amine equivalent weight of 1200 g/mol
• B-4: Amino-modified silicone with a kinematic viscosity of 40 mm ² /s at 25°C and an amine equivalent weight of 1800 g/mol
• B-5: Amino-modified silicone with a kinematic viscosity of 8000 mm ² /s at 25°C and an amine equivalent weight of 1000 g/mol
• B-6: Polyether-modified silicone with a kinematic viscosity of 500 mm ² /s at 25°C and with ethylene oxide/propylene oxide=100/0 and a silicone/polyether mass ratio=50/50
• B-7: Polyether-modified silicone with a kinematic viscosity of 1,700 mm ² /s at 25°C and with ethylene oxide/propylene oxide=40/60 and a silicone/polyether mass ratio=20/80
• B-8: dimethyl silicone having a kinematic viscosity of 10,000 mm ² /s at 25°C
• B-9: Thiodipropionic acid di(n-dodecyl) ester
• B-10: Dilauryl ester of an adduct of bisphenol A containing 2 moles of ethylene oxide

Experimental Part 2 (Manufacture of Synthetic Fibers and Carbon Fibers)

First, in step 1, an acrylic resin was spun into synthetic fibers in a wet spinning process. Specifically, a copolymer composed of 95% by mass of acrylonitrile was 3.5 % by mass of methyl acrylate and 1.5 % by mass of methacrylic acid having an intrinsic viscosity of 1.80 dissolved in dimethylacetamide (DMAC) to prepare a dope having a polymer concentration of 21.0 % by mass and a viscosity of 500 poise at 60°C. The spinning solution was discharged from a 12,000-hole spinneret with a hole diameter (clearance) of 0.075 mm at a stretching rate of 0.8 into a coagulation bath formed as an aqueous DMAC solution (70% by mass) and at a spinning bath temperature of 35° C was held.

The coagulated thread was stretched 5 times while being desolventized in a rinsing tank to recover acrylic fiber strands (raw material fibers) in a water-saturated state. To these acrylic fiber strands, the treating agents for synthetic fibers prepared in Experimental Part 1 were respectively applied so that a solid attachment would be 1% by mass (not counting the solvent). The application of each synthetic fiber treating agent was carried out by an immersion process using a 4% solution of the synthetic fiber treating agent in ion-exchanged water. Thereafter, the acrylic fiber strands were subjected to a drying and compacting process at 130°C with an arrangement of heating rollers, further subjected to stretching at 170°C by a factor of 1.7 between heating rollers, and then they were wound by means of a winder (hereinafter also referred to as referred to as a winder) wound onto a spool.

Next, in step 2, filaments were unwound from the wound synthetic fibers, and after being subjected to fireproof treatment for one hour in a fireproofing treatment furnace having a temperature range of 230°C to 270°C in an air atmosphere, the filaments were wound on a bobbin to to win flame-retardant threads (flame-resistant fibers).

Then, in step 3, filaments were unwound from the wound flame retardant filaments and, after being converted into carbon fibers by a heat treatment in a carbonization furnace having a temperature range of 300°C to 1300°C in a nitrogen atmosphere, they were wound on a bobbin, to get the carbon fibers.

Experimental part 3 (evaluation)

For the respective treating agents according to Examples 1 to 23 and Comparative Examples 1 to 3, fuzzing of the synthetic fibers in the spinning step, bundling property of the flame retardant fibers, smoothness of the synthetic fibers and wetting property with respect to the synthetic fibers were evaluated. The respective test methods are described below. The test results are shown in Table 1 in the columns "Spray Fuzz", "Flame Retardant Fibers - Bundling Property", "Smoothness" and "Wetting Property".

(spinning lint)

• • Auswertungskriterien bezüglich Fusselbildung
  • ○○○ (hervorragend): Die Anzahl der Fusseln betrug 0 bis 2.
  • ○○ (zufriedenstellend): Die Anzahl der Fusseln betrug 3 bis 5.
  • ○ (akzeptabel): Die Anzahl der Fusseln betrug 6 bis 10.
  • × (schlecht): Die Anzahl der Fusseln betrug 11 oder mehr.

The number of lints per hour measured by a lint counter installed immediately before the winding device for winding the synthetic fibers in Step 1 of Experimental Part 2 was evaluated by the following criteria:

• • Evaluation criteria regarding fluff formation
  • ○○○ (Excellent): The number of lint was 0 to 2.
  • ○○ (satisfactory): The number of lint was 3 to 5.
  • ○ (acceptable): the number of lint was 6 to 10.
  • × (bad): The number of lints was 11 or more.

(Flame-retardant fibers - bundle property)

For the flame retardant fibers subjected to the fireproof treatment in Step 2 of Experimental Part 2, the bundling state of the flame retardant filaments before winding was visually observed, and the bundling property of the flame retardant fibers was evaluated by the following criteria:

• ○○ (zufriedenstellend): Bündelung ist erreicht und eine Spinnkabelbreite ist konstant.
• ○ (akzeptabel): Zwar ist eine Bündelung erreicht, jedoch ist die Spinnkabelbreite nicht konstant.
• × (schlecht): Es gibt Zwischenräume innerhalb der Faserbündel und eine Bündelung wurde nicht erreicht.

Evaluation criteria of the bundle property of the flame-retardant fibers

• ○○ (satisfactory): bundling is achieved and a tow width is constant.
• ○ (acceptable): Although bundling is achieved, the tow width is not constant.
• × (poor): There are gaps within the fiber bundles and bunching was not achieved.

(Smoothness)

As an apparatus for measuring a smoothness, an Autograph ABS-1kNX (tension tester) produced by Shimadzu was used.

• ○○○ (hervorragend): Der durchschnittliche Spannungswert beträgt weniger als 2N.
• ○○ (zufriedenstellend): Der durchschnittliche Spannungswert beträgt mindestens 2N, jedoch weniger als 3N.
• ○ (akzeptabel): Der durchschnittliche Spannungswert beträgt mindestens 3N, jedoch weniger als 4N.
• × (schlecht): Der durchschnittliche Spannungswert beträgt mindestens 4N.

Like in the 1 As shown, the synthetic fiber with the treatment agent attached (also referred to as test thread 1 hereinafter) was attached at one end to a gripping tool 2 of the autograph and passed in turn past a free roller 3, a chromed textured pin 4 and a free roller 5 ; at the other end of the test thread 1, a weight 6 of 50 g was attached. A driving shaft 4a with which the test thread 1 comes into contact on the chrome-plated textured pin 4 has a diameter of 1 cm and a surface roughness of 2S. An angle formed by a direction in which the test thread 1 extends between the chromed textured pin 4 and the free roller 5 relative to a direction in which the test thread 1 extends between the free roller 3 and the chromed textured pin 4 , is formed was set to 90°. In this state and under conditions of 25°C and 60%RH, the drive shaft 4a of the chromed textured pin 4 was brought into a state of being rotated at a peripheral speed of 100 m/minute in a direction in which the autograph tension was applied and the tension was measured by the autograph at 0.1 second intervals for 30 seconds. An average value (N) for the stress during this period was determined and evaluated using the following criteria:

• ○○○ (Excellent): The average tension value is less than 2N.
• ○○ (satisfactory): The average tension value is at least 2N but less than 3N.
• ○ (acceptable): The average tension value is at least 3N but less than 4N.
• × (bad): The average stress value is 4N or more.

(wetting property)

• ○○ (zufriedenstellend): Der maximale Durchmesser beträgt 12 mm oder mehr.
• ○ (akzeptabel): Der maximale Durchmesser beträgt mindestens 10 mm, jedoch weniger als 12 mm.
• × (schlecht): Der maximale Durchmesser beträgt weniger als 10 mm.

For each synthetic fiber treating agent, a 4% solution of the effective ingredients in ion-exchanged water (a solution in which that portion which was not ion-exchanged water constituted the effective ingredients) was prepared; from this solution, 0.1 g was dropped on an acrylic plate, a maximum diameter (mm) after 1 minute was measured and evaluated by the following criteria:

• ○○ (satisfactory): The maximum diameter is 12 mm or more.
• ○ (acceptable): the maximum diameter is at least 10mm but less than 12mm.
• × (bad): The maximum diameter is less than 10 mm.

The results listed in Table 1 show that the present invention is capable of adequately preventing fuzzing of the synthetic fibers in the spinning step. In addition, both the bundling property of the flame retardant fibers and the smoothness of the synthetic fibers can be improved. Furthermore, the wetting property with respect to the synthetic fibers is improved by the treatment agent according to the invention.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• WO 2017169632 [0004]

Claims (22)

A process for preparing a synthetic fiber treatment agent, wherein a boron content of the non-volatile portion of the synthetic fiber treatment agent, determined by ICP emission spectrometry, is 200 ppm or less; the method comprising: an addition step of adding an alkylene oxide to an alcohol in the presence of a catalyst containing a boron atom in its molecule to produce a (poly)oxyalkylene derivative, and a discharging step of discharging the catalyst so that the boron content of the non-volatile portion of the synthetic fiber treating agent is 200 ppm or less as determined by ICP emission spectrometry. Process for preparing a synthetic fiber treating agent claim 1 wherein, in the taking out step, the catalyst is taken out so that the boron content of the non-volatile portion of the synthetic fiber treating agent is 40 ppm or less as determined by ICP emission spectrometry. Process for preparing a synthetic fiber treating agent claim 1 or 2 wherein the (poly)oxyalkylene derivative has a composition in which an alkylene oxide having 2 to 4 carbon atoms is added in a ratio of 1 to 30 moles in total to 1 mole of an alcohol. A process for preparing a synthetic fiber treating agent according to any one of Claims 1 until 3 , where the alcohol has an alkyl chain with 10 to 18 carbon atoms in its molecule, A process for preparing a synthetic fiber treating agent according to any one of Claims 1 until 4 , the alcohol having in its molecule an alkyl chain with 12 to 16 carbon atoms. Process for preparing a synthetic fiber treating agent claim 4 or 5 , wherein the alcohol is a monohydric aliphatic alcohol having a hydroxy group at a β-position of an alkyl chain. A process for preparing a synthetic fiber treating agent according to any one of Claims 1 until 6 , further comprising a mixing step in which a smoothing agent is mixed in. Process for preparing a synthetic fiber treating agent claim 7 , wherein the smoothing agent contains silicone. Process for preparing a synthetic fiber treating agent claim 7 or 8th , wherein the smoothing agent contains an amino-modified silicone. A process for preparing a synthetic fiber treating agent according to any one of Claims 7 until 9 , wherein in the mixing step the smoothing agent is mixed in such that - if the sum of the content of (poly)oxyalkylene derivative and smoothing agent is calculated as 100 parts by mass - the proportion of the (poly)oxyalkylene derivative is 10 to 70 parts by mass and the proportion of the smoothing agent is 90 is up to 30 parts by weight. A process for preparing a synthetic fiber treating agent according to any one of Claims 1 until 10 , wherein the synthetic fiber is a carbon fiber precursor. Treatment agent for synthetic fibers, which contains a smoothing agent and a (poly)oxyalkylene derivative, wherein the boron content of the non-volatile portion of the treatment agent, determined by ICP emission spectrometry, is at least 0.1 ppm and at most 200 ppm. Synthetic fiber treatment agents claim 12 , the boron content not exceeding 40 ppm. Synthetic fiber treatment agents claim 12 or 13 wherein the (poly)oxyalkylene derivative has a composition in which an alkylene oxide having 2 to 4 carbon atoms is added in a total ratio of 1 to 30 moles to 1 mole of alcohol. Synthetic fiber treatment agents Claim 14 , the alcohol having in its molecule an alkyl chain of 10 to 18 carbon atoms. Synthetic fiber treatment agents Claim 14 or 15 , the alcohol having in its molecule an alkyl chain with 12 to 16 carbon atoms. Synthetic fiber treatment agents claim 15 or 16 , wherein the alcohol is a monohydric aliphatic alcohol having a hydroxy group at a β-position of an alkyl chain. Synthetic fiber treatment composition according to any one of Claims 12 until 17 , wherein the smoothing agent contains an amino-modified silicone. Synthetic fiber treatment composition according to any one of Claims 12 until 18 , where - when the sum of the content of (poly)oxyalkylene derivative and smoothing agent is calculated as 100 parts by mass - the proportion of the (poly)oxyalkylene derivative is 10 to 70 parts by mass and the proportion of the smoothing agent is 90 to 30 parts by mass. Synthetic fiber treatment composition according to any one of Claims 12 until 19 , wherein the synthetic fiber is a carbon fiber precursor. Synthetic fiber to which the treatment agent for synthetic fibers according to any one of Claims 12 until 19 attached. A method for producing a synthetic fiber, in which the treating agent for synthetic fibers according to any one of Claims 12 until 19 attached to a fiber.

Images