JPS5930804B2 - Method for producing antistatic acrylic synthetic fiber with improved fiber performance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an antistatic acrylic synthetic fiber with improved fiber performance, and more specifically, the present invention relates to a method for producing an antistatic acrylic synthetic fiber with improved fiber performance. After mixing a copolymer (A) consisting of a body polar unit, etc. and an acrylic polymer (B) such that the antistatic monomer unit is contained in a specific amount with respect to the total polymer weight, The present invention relates to a method for producing an antistatic acrylic synthetic fiber that has significantly improved fiber performance during spinning.

Traditionally, acrylic synthetic fibers have exhibited excellent characteristics in terms of heat retention, shrinkage, shape stability, weather resistance, texture, dyeability, etc., and their demand for use in clothing and interior design is increasing. well known.

However, such acrylic synthetic fibers are not without practical limitations, and there are several problems that require urgent measures to be taken.

For example, when wearing clothing made of the above-mentioned acrylic synthetic fibers or using it as a carpet, etc., static electricity accumulates, causing problems such as causing extreme discomfort to the human body, and significantly reducing their commercial value. This became a drawback. As a way to eliminate such static electricity interference,
Conventionally, a method of treating acrylic synthetic fibers with an antistatic agent selected from the group consisting of surfactants, and a method of adding the antistatic agent to an acrylic polymer spinning stock solution for spinning have been generally used. However, in these methods, the above-mentioned antistatic agent easily falls off during the fiber manufacturing process, or during dyeing, bleaching, and even washing after the product is made, so it is difficult to find an antistatic agent that has sufficient durability. It had the fatal flaw of being unable to achieve its desired effects.

As another method, as described in U.S. Pat. No. 3,507,935, a copolymer obtained by copolymerizing acrylonitrile and alkoxypolyethylene glycol acrylate, etc. is used for the purpose of imparting antistatic properties to the final fiber. A technique has been proposed in which a polymer and a well-known acrylonitrile polymer are mixed and then spun.

However, although a certain degree of antistatic effect is certainly observed in such antistatic imparting means, on the other hand, there are disadvantages derived from the incompatibility of the above two types of polymers, that is, the final acrylic synthesis Practically satisfactory transparency (color development) cannot be imparted to the fibers, and the acrylic synthetic fibers undergo fifrillation, resulting in a significant decrease in the physical properties of the final fibers, such as bending strength and frictional strength.
(More generally speaking, in antistatic acrylic synthetic fibers, as the antistatic properties improve, the above-mentioned fiber performance decreases, and on the other hand, the fiber performance improves.) It is a well-known fact in the art that if an attempt is made to reduce the amount of electricity, the antistatic properties will be adversely affected. Considering the above circumstances, the tooling technology that gives acrylic synthetic fibers practically satisfactory antistatic properties and at the same time good fiber performance (e.g. color development, spinnability, etc.) has not yet reached the practical stage. It is no exaggeration to say that they have not. Here, the present inventors solved the various limitations associated with the conventional techniques as described above, and created a fiber that was significantly improved in the final fiber without any deterioration in the antistatic performance of the acrylic synthetic fiber. As a result of intensive research aimed at establishing industrial means for imparting performance, we have found that the object of the present invention can be effectively achieved by selecting and using a mixed polymer having a predetermined composition. This discovery led to the present invention.

The main object of the present invention is therefore to propose a method for producing antistatic acrylic synthetic fibers with improved fiber performance. Another main object of the present invention is to provide an industrial method for producing antistatic acrylic synthetic fibers to impart significantly improved transparency without any deterioration in the physical performance of the synthetic fibers. The aim is to find technical means with excellent practical utility.

Further different objects will become apparent from the description below.

Therefore, such an object of the present invention is that acrylonitrile 20
~70% by weight, unsaturated amide N-methylol compound 1
~15% by weight and compound 7 represented by the following general formula (1)
A copolymer (A) obtained by copolymerizing a monomer mixture comprising 9 to 15% by weight, and an acrylic resin comprising at least one of polyacrylonitrile or 70% by weight or more of acrylonitrile and another polymerizable unsaturated vinyl compound. This can be achieved by mixing the compound represented by the following general formula (1) with the polymer (B) so that it accounts for 1 to 10% by weight based on the total mixed polymer, and then spinning the mixture. .

CH2=CRCOO(CH2CH2O)nbi (1)(
(in the formula, n is an integer of 4 to 40, R is a hydrogen atom or a methyl group, and bi represents a hydrogen atom or an alkyl group having 8 or less carbon atoms). A copolymer (A) containing an amount of an unsaturated amide N-methylol compound and an antistatic monomer structural unit represented by the general formula (1), etc., and an acrylic polymer (B) are mixed together. By mixing the electrically conductive monomer constituent units in a predetermined amount with respect to the total mixed polymer and then spinning, the various problems that occurred with conventional methods of imparting antistatic properties can be resolved. It had become a thing.

The present inventors have also clarified the mechanism by which the fiber performance (transparency, flexural strength, frictional strength, etc.) of the final fiber is significantly improved by selecting and using a copolymer having a specific composition in the method of the present invention. Although no theoretical basis has been found, it is possible that the filament formed into a fiber after spinning develops a crosslinked structure resulting from the condensation reaction of the N-methylol group of the unsaturated amide during the subsequent drying and densification step. Therefore, even if subjected to the inherited relaxation heat treatment, the heat shrinkability of the acrylic polymer j and the N-methylol group-containing copolymer, which are the filament forming components, are maintained at the same level. This is presumed to be because the peeling behavior of the above two types of fiber-forming polymer components is suppressed and the generation of voids (VOid) is prevented. Polyacrylonitrile or an acrylic polymer (B) comprising 70% by weight or more of acrylonitrile and at least one other polymerizable unsaturated vinyl compound used in the present invention can be prepared by a well-known polymerization method, such as suspension polymerization, emulsion Polymerizable unsaturated vinyl compounds that can be produced by polymerization methods, solution polymerization methods, etc. and are copolymerizable components of acrylonitrile include acrylic acid, methacrylic acid, or esters thereof such as methyl esters and ethyl esters; acrylamide , methacrylamide or N-alkyl substituted products thereof; vinyl esters such as vinyl acetate and vinyl propionate; vinyl halides or vinylidenes such as vinyl chloride, vinyl bromide, and vinylidene chloride; vinyl sulfonic acid, allyl sulfonic acid, Unsaturated sulfonic acids such as methacrylsulfonic acid and p-styrenesulfonic acid or salts thereof; well-known unsaturated compounds copolymerizable with acrylonitrile such as styrene and methacrylonitrile can be mentioned.

The copolymer (A) which is a mixing partner of the acrylic polymer includes 20 to 70% by weight of acrylonitrile, 1 to 15% by weight of an unsaturated amide N-methylol compound, more preferably 2 to 10% by weight, and General formula CH2=CRCO
It is an essential requirement that 79 to 15% by weight of an antistatic monomer represented by O(CH2CH2O)NR'' is copolymerized.

That is, when the acrylonitrile content is less than 20% by weight based on the weight of the copolymer, disadvantages are observed in antistatic durability, which is undesirable.On the other hand, when the acrylonitrile content exceeds 70% by weight, Sufficient antistatic effect is not provided. Furthermore, if the content of the N-methylol compound in the unsaturated amide is less than 1% by weight based on the weight of the copolymer, it will be difficult to introduce a satisfactory crosslinked structure into the fiber, and the final fiber will be This is undesirable because it lowers the physical performance. On the other hand, if the content of the N-methylol compound exceeds 15% by weight, a crosslinking reaction occurs in the polymerization process and the copolymer becomes gelled, which is undesirable. Furthermore, if the content of the antistatic monomer constitutional unit is less than 15% by weight or more than 79% by weight based on the weight of the copolymer, satisfactory antistatic performance durability cannot be obtained, so it is preferable. do not have. In addition, the above ternary copolymer is
Obtained by adopting the same polymerization method (suspension polymerization method, emulsion polymerization method, solution polymerization method, etc.) as for the production of the above-mentioned acrylic polymer,
The polymerization catalyst used in such polymerization is also known (benzoyl peroxide, azobisisobutyronitrile, persulfate, hydrogen peroxide, redox initiators such as persulfate and acidic sodium sulfite, and radical polymerization initiators such as ultraviolet rays). etc)
Manufactured by arbitrarily selecting from. Further, as the unsaturated amide N-methylol compound according to the present invention, N-methylol acrylamide, N-methylolmethacrylamide, N-methylolallylamide, α-methyleneglutaramide N-methylol compounds, etc. can be mentioned. I can do it. The thus obtained two types of polymers (A and B) are then prepared such that the antistatic monomer constitutional unit represented by the above general formula is contained in an amount of 1 to 10% by weight based on the weight of the total mixed polymer. It is necessary to mix it so that it is preserved.

That is, if the amount of the antistatic monomer constituent unit is less than 1% by weight based on the weight of the entire mixed polymer, it will be difficult to impart sufficient antistatic properties to the final fiber; If it exceeds 10% by weight, it is undesirable because it impairs the dyeability and physical properties of the final fiber. In addition, as for means for adjusting the content of the antistatic monomer constituent units as described above to satisfy a predetermined range, acrylic polymers and tertiary copolymers (such as unsaturated amide N-methylol compounds, etc.) are used. This can be achieved by appropriately determining the mixing ratio with the copolymer (containing copolymer). Furthermore, there are no particular restrictions on the method of mixing the two types of polymers mentioned above, and any conventional mixing means can be selected. For example, (1) acrylic polymer (B
) and the terpolymer (A) are mixed and then dissolved in an arbitrary solvent to form a spinning stock solution; (6) a spinning stock solution of the acrylic polymer (B) and the copolymer (A); A method of mixing the copolymer (A) with a spinning dope of the acrylic polymer (B) to form a spinning dope;
3) Add acrylic polymer (B) to the yarn-protecting stock solution of copolymer (A).
) is selectively used to prepare a spinning dope.
In addition, the above-mentioned copolymer (A) and acrylic polymer (
The solvent used for preparing the spinning dope in B) may be an organic solvent such as dimethylformamide, dimethylacetamide, dimethyl sulfoxide, ethylene carbonate, γ-butyrolactone, etc. or an inorganic solvent such as a concentrated aqueous solution of sodium thiocyanate, zinc chloride, nitric acid, etc. Among them, the features of the present invention can be advantageously exhibited by using a concentrated aqueous solution of sodium thiocyanate as the solvent constituting the spinning dope. The mixed polymer spinning dope thus prepared is then spun to form a fiber thread, and the thread is subsequently subjected to water washing, hot stretching, drying and densification, relaxing heat treatment, crimp imparting treatment, etc. to produce the final fiber.

In addition, as a preferred embodiment in this fiber manufacturing process, the swollen gel-like fibers after hot drawing are immersed in an aqueous solution containing an inorganic acid and/or the dry densification is carried out for at least 90 min.
It is recommended that the test be carried out for at least 5 minutes at a temperature of ℃.
By adopting such a manufacturing process, the introduction of a crosslinked structure into the fiber due to the condensation reaction of the N-methylol compound can be more effectively achieved, thus improving the transparency and physical performance of the final fiber. Further improvements can be made. Although there are no particular restrictions on the spinning means according to the present invention, a wet spinning method is preferably employed in order to advantageously achieve the features of the present invention. Examples of the present invention will be described below, but the scope of the present invention is not limited in any way by these Examples.

Unless otherwise specified, all parts and percentages are expressed on a weight basis.In addition, the antistatic properties, transparency, and fifrillation described in the following examples were each measured by the following methods. Or say what you evaluated. (1)
Antistatic property The finally obtained acrylic synthetic fiber is manufactured by Monogen Uni (
Procter & Gambre Saint Home Co.) containing liquid (
The solution was then heated to 60-100°C for 30 minutes, and then heated to 100°C for 30 minutes.
℃ for 60 minutes to prepare test fibers.

Next, the test fibers were subjected to humidity conditioning for two days and nights at a temperature of 20° C. and a relative temperature of 40%. After that, take out the sample fiber,
The half-life was measured using a static neostometer (manufactured by Shishido Shokai) under the following conditions. Stats Honest Meter - How to use Applied voltage: 10,000 volts Application time: 3 minutes Sample rotation speed: 1,000 r. p. m The above half-life indicates that the shorter the half-life, the better the antistatic property of the treated fiber.

In addition, the washing fastness (antistatic durability) related to antistatic properties was determined by washing the finally obtained acrylic synthetic fiber in a household electric washing machine (Monogen Uni concentration 2V/11 bath ratio 1/50 to 1/10).
0140℃), washed for 10 minutes, washed with water for 20 minutes, and dried further (durability evaluation:
This operation is repeated) and evaluated by subjecting it to the antistatic property measurement as described above.

(2) Transparency The finally produced acrylic synthetic fiber is cut into two fin lengths, and this 105η is dimethyl phthalate with a refractive index of 1.512, acetophenone with a refractive index of 1.529, and 1.358 with a refractive index of After mixing ethanol and dispersing it in a solution whose refractive index was adjusted to 1.506, the dispersion was vertically
A certain amount of the sample was placed in a measuring cell of width x height = 1 x 1 x 5 cm, and evaluation was made from the transmittance measured by applying light with a wavelength of 420 mμ perpendicular to the cell surface.

(3) After cutting the fifurlylated acrylic synthetic fiber into pieces of 5 to 771 Lm, put 200 watts of this into a household electric user (Toshiba M-201G model) along with 200 ml of water, and add about 1500 r.m. p
．． The mixture was stirred for 120 minutes.

The post-treated fibers were subjected to microscopic observation to evaluate the degree of fifurlation of the fibers. Example 1 A copolymer (A) was prepared by copolymerizing 47 parts of acrylonitrile, 6 parts of N-methylolacrylamide, and 47 parts of methoxypolyoxyethylene (25 mol) methacrylate.

On the other hand, 91 parts of acrylonitrile, 8 parts of methyl acrylate.
7 parts and 0.3 parts of sodium methacrylsulfonate were copolymerized to obtain an acrylic polymer (B). Next, the two kinds of polymers thus prepared were mixed so that the ratio of copolymer (A) to acrylic polymer (B) was 1:11 (the ratio of methoxypolyoxyethylene methacrylate to the total mixed polymer weight) The content was 3.9%) and then dissolved in a 44% aqueous solution of sodium lactate to prepare a uniform spinning stock solution.

Thereafter, the spinning dope is subjected to wet spinning under normal conditions.
After being washed with water and hot-stretched, it was subjected to dry densification and relaxation heat treatment at 100°C to produce a single fiber 3-denier acrylic synthetic fiber. Table 1 shows the results of measuring the antistatic property, antistatic durability, and fiber performance of the acrylic synthetic fiber thus obtained. As a comparative example, a copolymer (C) was prepared by copolymerizing 50 parts of acrylonitrile, 50 parts of methoxypolyoxyethylene (25 mol), and 50 parts of methacrylate, and mixed with the above-mentioned acrylic polymer (B) (the mixing ratio was (same as above), a final fiber of single denier was produced by employing the same fiber manufacturing process as above.

The antistatic properties and fiber performance of such fibers are also listed in Table 1.
From the results shown in Table 1, it can be seen that the acrylic synthetic fiber according to the present invention has practically satisfactory antistatic properties, as well as good transparency and spinnability. .

When the two types of acrylic synthetic fibers mentioned above were cationically dyed under normal dyeing conditions, the acrylic synthetic fiber of the present invention had a clear color tone, whereas the comparative example had a white color. The product was not clear and had inferior commercial value.

This fact can be easily confirmed from the transparency measurement results shown in Table 1. Example 2 40 parts of acrylonitrile, 10 parts of N-methylolacrylamide and methoxypolyoxyethylene (23 moles)
A copolymer was prepared by copolymerizing 50 parts of methacrylate.

Next, such a copolymer and the same acrylic polymer as in Example 1 were mixed at a ratio of 1:10 (the content of methoxypolyoxyethylene methacrylate was 4.5% based on the weight of the total mixed polymer), and then It was dissolved in a 47% aqueous solution of sodium lactate to obtain a homogeneous spinning stock solution.

The spinning stock solution was then wet-spun, washed with water, and hot-stretched, and the resulting swollen gel-like yarn was immersed in an aqueous sulfuric acid solution under the conditions listed in Table 2, and then the same fibers as in Example 1 were prepared. Through the manufacturing process, it was made into a single fiber 3 denier acrylic synthetic fiber. The antistatic properties and fiber performance of the acrylic synthetic fiber thus obtained are shown in Table 2.

From the results in Table 2, the acrylic synthetic fiber according to the present invention (
In particular, it will be clearly understood that the swollen gel-like fibers prepared by subjecting the swollen gel-like fibers after hot stretching to an inorganic acid aqueous solution treatment significantly improve not only the antistatic properties but also the fiber performance.

In addition, the above-mentioned acrylic synthetic fiber (with sulfuric acid treatment; 0.0
1%) and that of the comparative example were fed to a spinning machine, the acrylic synthetic fiber according to the present invention showed good spinnability (low frequency of single yarn breakage), whereas that of the comparative example showed good spinnability (low frequency of single yarn breakage). Yarn breakage occurred frequently, making it difficult to produce a satisfactory spun acrylic fiber yarn.

Claims (1)

[Scope of Claims] 1. A monomer mixture consisting of 20 to 70% by weight of acrylonitrile, 1 to 15% by weight of an unsaturated amide N-methylol compound, and 79 to 15% by weight of a compound represented by the following general formula (I). A copolymer (A) obtained by copolymerizing and an acrylic polymer (B) consisting of polyacrylonitrile or 70% by weight or more of acrylonitrile and at least one other polymerizable unsaturated vinyl compound are combined into the following general formula: The compound represented by (I) is 1 to 1% of the total mixed polymer.
A method for producing an antistatic acrylic synthetic fiber with improved fiber performance, which comprises mixing the fibers so as to account for 0% by weight and then spinning the fibers. CH_2=CRCOO(CH_2CH_2O)_nR'
(I) (in the formula, n is an integer of 4 to 40, R is a hydrogen atom or a methyl group, and R' represents a hydrogen atom or an alkyl group having 8 or less carbon atoms).