JP3144087B2 - Acrylic fiber and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel acrylic fiber having improved dyeability and hygroscopicity compared with conventional acrylic fibers for use in clothing. Further, the acrylic fiber of the present invention can be processed into a functional fiber such as ion exchange, chelate, deodorant, antibacterial, and immobilized enzyme as a fiber containing a primary amino group.

[0002]

2. Description of the Related Art Conventionally, to improve the hygroscopicity and dyeability of acrylic fibers for use in clothing, a method of copolymerizing a monomer containing an amide group with acrylonitrile and then spinning the same (for example, see For example, when N-substituted acrylamide is contained in a fiber, there is a problem that thermal stability is poor and shrinkage is too high.

On the other hand, as a fiber containing a primary amino group used for applications such as ion exchange, chelation, deodorization, and antibacterial, a method of aminomethylating styrene has been known.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an acrylic fiber having a low shrinkage, improved hygroscopicity and dyeability without impairing the performance of the conventional acrylic fiber, or a primary amino group. And to provide an acrylic fiber containing the same.

[0005]

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, after copolymerizing acrylonitrile and N-vinylformamide and / or N-vinylacetamide, As a result, the present inventors have found that the problem can be solved, and reached the present invention.

That is, the present invention provides the following structural unit (I)
The present invention relates to an acrylic fiber containing 85 to 99.9 mol% (acrylonitrile unit) and 0.1 to 15 mol% of the following structural unit (II) (N-vinylcarboxylic amide unit).

[0007]

Embedded image (Wherein, R represents a hydrogen atom or a methyl group) Hereinafter, the present invention will be described in detail.

In the copolymer used in the present invention, the structural unit (I) is contained in an amount of 85 to 99.9% by mole, and the structural unit (II) is added in an amount of 0.
It contains 1 to 15 mol%. As a preferable composition of the copolymer of the present invention, (I) is 88 to 99.5 mol%, (II)
Is 0.5 to 12 mol%. The viscosity of the copolymer in dimethyl sulfoxide is usually 10 to 10,000 poise, preferably 50 to 5000 poise, more preferably 100 to 3000 poise when the copolymer concentration is 15% by weight and the temperature is 50 ° C. It is.

Conventionally, in the fiber containing the acrylamide derivative, if the content is usually 5 to 10 mol%, the fiber shrinks. However, the fiber of the present invention has a low shrinkage. When the structural unit (II) of the polymer constituting the fiber of the present invention is contained in an amount exceeding 15 mol%, the polymer tends to shrink slightly, and when the structural unit (II) exceeds 30 mol%, the hydrophilicity becomes high. As a result, some of the fibers are fused. When the structural unit (II) is contained in an amount of 60 mol% or more, it is difficult to coagulate the obtained copolymer solution in water and spin it.

When the acrylic fiber of the present invention is used for ion exchange, chelate, deodorant, antibacterial, etc.,
As the copolymer, a cationic copolymer obtained by modifying the structural unit (II) in addition to the structural units (I) and (II) is usually 0.1% or more, particularly 1.0% or more. When the structural unit (II) is modified, usually the following structural unit (III)
(Vinylamine units), but depending on the monomer composition of the acrylic fiber and the modification conditions, adjacent secondary amide groups,
It may contain an amidine or lactam ring-closed structure by reacting with a nitrile group, an amide group or a carboxyl group generated by modification of the nitrile group.

[0011]

Embedded image

The structural unit (III) having a primary amino group is
Usually, those containing 0.1 to 15 mol%, preferably 1 to 10 mol% are used. The structural units (III) can be present in the form of free amino groups, salts of mineral or organic acids, or ammonium salts. The structural unit (III) can be obtained by copolymerizing monomers such as N-vinylphthalimide and N-vinylsuccinimide, and then partially modifying the copolymer under acidic or basic conditions. From the viewpoint of copolymerizability, it is preferable to obtain a polymer by partially modifying the structural unit (II). The details of this modification method will be described later.

As a method for producing the copolymer, N-vinylformamide and / or N-vinylacetamide are added in an amount of 0.1 to 99.9 to 85 mol% of acrylonitrile.
The copolymerization is carried out at a ratio of １５15 mol%, preferably 0.5〜12 mol%, and further modification is performed if necessary. From the viewpoint of copolymerizability with acrylonitrile, fiber properties obtained from the copolymer, ease of modification, and the like, it is preferable to use N-vinylformamide rather than N-vinylacetamide. In some cases, they can be used as a mixture.

The raw material copolymer used for the modification reaction is prepared by preliminarily adjusting the amount of the monomer so that the final composition becomes the target composition. In addition, as long as the properties of the acrylic fiber of the present invention are not impaired, other hydrophilic monomer units are usually contained in an amount of 0 to 10 mol%, preferably 0 to 5 mol%, more preferably 0 to 1 mol%. Can be used in a range.

Such hydrophilic monomer units include (meth) acrylamide, N-substituted (meth) acrylamide, N, N-dialkyl (meth) acrylamide,
N-dialkylaminoalkyl (meth) acrylamide, N-alkyl-N-formamide, N-alkyl-
Neutral monomers such as N-vinylacetamide, dialkylaminoalkyl (meth) acrylate, allyl alcohol, vinyl alcohol, N-vinylpyrrolidone, vinylpyridines, vinylimidazole, (meth) acrylamidoalkyltrimethylammonium salt, hydroxyalkyl ( Basic monomers such as (meth) acryloyloxyalkyltrimethylammonium salt, diallylalkylammonium salt, vinylbenzyltrialkylammonium salt, (meth) acrylamidoalkanesulfonic acid,
Metal salts or ammonium salts of acidic monomers such as (meth) acrylic acid, (meth) acryloyluoxyoxyalkanesulfonic acid, (meth) allylsulfonic acid, and vinylsulfonic acid.

Other hydrophobic monomers can be used in an amount of usually 0 to 15 mol%, preferably 0 to 5 mol%, as long as the properties of the acrylic fiber of the present invention are not impaired. Such hydrophobic monomer units include methyl acrylate, ethyl acrylate, butyl acrylate, octyl acrylate, methoxyethyl acrylate,
Acrylates such as phenyl acrylate and cyclohexyl acrylate; methacrylates such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, methoxyethyl methacrylate, phenyl methacrylate and cyclohexyl methacrylate; methyl Unsaturated ketones such as vinyl ketone, ethyl vinyl ketone, phenyl vinyl ketone and methyl isopropenyl ketone; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate and vinyl benzoate; vinyl ethers; vinyl chloride and vinyl bromide Vinyl or vinylidene halides, such as vinylidene chloride and vinylidene chloride;
(Meth) acrylonitrile; glycidyl methacrylate, styrene and the like.

As the polymerization method, a known method may be used, and any of a solution polymerization method, a suspension polymerization method, a precipitation polymerization method, an emulsion polymerization method and a bulk polymerization method may be used. Examples of the polymerization initiator include azo compounds such as azobisisobutyronitrile and 2,2′-azobis (2,4-dimethylvaleronitrile); peroxides such as benzoyl peroxide and potassium persulfate; A known catalyst such as a catalyst is used. Further, a polymerization method using heat, light, or radiation may be used without using a polymerization catalyst. Generally, the polymerization reaction is carried out under an inert gas stream.
It is carried out under a temperature condition of 30 to 100 ° C.

The method for modifying the copolymer containing a secondary amide group obtained by the above method into a copolymer containing the structural unit (III) may be carried out under an acidic condition or a basic condition. There is a method of performing decomposition. The denaturation method includes a method of performing acidic hydrolysis in water, a method of performing acidic hydrolysis in a hydrophilic solvent such as an alcohol containing water, a method of performing hydrolysis without a solvent in an atmosphere of hydrochloric acid gas, and alcoholysis under acidic conditions. Then, a method of modifying the secondary amide group while separating it as an alkyl ester and the like are exemplified. In the case of alcoholysis, any of commonly known alcohols is used, but preferably alcohols having 1 to 4 carbon atoms are used.

As the denaturing agent used in the case of acid denaturation, any compound that acts strongly acidic can be used. For example, hydrochloric acid, bromic acid, hydrofluoric acid, sulfuric acid, Examples include nitric acid, phosphoric acid, sulfamic acid, and alkanesulfonic acid. The amount of the modifier used is appropriately determined in a range of 0.1 to 10 moles per mole of the second amide group in the polymer, depending on the desired modification rate. In addition, the denaturation reaction is usually performed under the conditions of 40 to 120 ° C.

Further, the above-mentioned modification treatment can also be carried out after the fiberizing step of the copolymer described below. Then, from the viewpoint of the coagulation characteristics of the modified copolymer, it is preferable that the unmodified copolymer is formed into fibers and then modified only near the fiber surface. The purpose of the modification is to obtain a copolymer mainly containing the structural unit (III) as described above, but at the time of the modification, a part of the structural unit (I) in the nitrile portion of the polymer is decomposed. , An amide group, a carboxyl group, etc. Structural units generated by the decomposition of the nitrile group may be included in the copolymer as long as they satisfy the range of the composition of the copolymer specified in the present application. Is preferred. Therefore,
As the denaturing condition, the basic condition is generally more preferable because the nitrile group tends to be decomposed more easily under the basic condition.

The thus obtained nitrile copolymer having the copolymer composition according to the present invention is a solvent capable of dissolving the copolymer, that is, an organic solvent such as dimethyl sulfoxide, dimethylformamide, dimethylacetamide, etc. Alternatively, it is dissolved in a solvent commonly used for the production of acrylic fibers, such as an inorganic solvent such as zinc chloride, a rodane salt, and an aqueous solution of nitric acid, or a mixed solvent thereof, to obtain a spinning dope. The amount of the copolymer that can be dissolved in these solvents depends on the molecular weight of the polymer used, but is usually 5 to 40% by weight, preferably 10 to 10% by weight, based on the total amount of the spinning dope.
３０30% by weight.

The stock solution for spinning acrylic fiber of the present invention can be prepared by dissolving the acrylonitrile-based copolymer obtained after the above-mentioned polymerization method and, if necessary, modification, in the above-mentioned solvent. It is preferable to carry out the copolymerization in a solvent used for the stock solution because the step of dissolving the polymer in the solvent can be omitted. As the solvent, dimethyl sulfoxide, dimethylformamide and the like are used.

Next, the method of fiberizing the spinning stock solution is not particularly limited, but usually, after defoaming and filtering, the temperature of the spinning stock solution is set to 25 to 100 ° C., and a solvent (coagulation bath) for coagulating the solution is used. Among them, a method of spinning through a spinneret is preferable. As the coagulation bath, any coagulation bath used in a known acrylic fiber manufacturing method such as water or a mixed aqueous solution of water and a solvent of the above-described copolymer solution can be used. As the coagulation bath, for example, the concentration of the solvent is 0 to 0.
An aqueous solution of 80% by weight at a temperature of 0 to 50 ° C can be mentioned. The obtained coagulated yarn is further subjected to known post-treatments such as washing with water, single-stage or multi-stage stretching, drying, and densification,
Acrylic fibers are produced. Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples as long as the gist is not exceeded.

Examples 1 to 4 and Comparative Examples 1 and 2 Acrylonitrile (hereinafter abbreviated as AN) and N-vinylformamide (hereinafter abbreviated as NVF) were placed in a 200 ml four-necked flask equipped with a stirrer, a nitrogen inlet tube and a cooling tube. ) To Table 1
30 g as a mixture having a molar ratio shown in
0.5% by weight of 2'-azobis (2,4-dimethylvaleronitrile) based on the monomer and 120 g of dimethyl sulfoxide were added, and the mixture was stirred at room temperature in a nitrogen gas stream for 30 minutes. Thereafter, the mixture was kept at 50 ° C. for 10 hours under stirring,
A polymerization liquid was obtained.

The polymerization solution is directly used as a spinning solution, and after defoaming, is extruded into a 20% by weight aqueous solution of dimethyl sulfoxide at a pressure of 2.0 kg / cm ² using a nozzle having a pore diameter of 0.2 mm to form a fiber. I got something. The obtained fiber is subjected to post-treatments such as washing and drying, and then fineness (d) and strength (g /
d), elongation (%), dyeability and hygroscopicity were tested. The results are shown in Table 1.

The fineness was measured according to the method of JIS-L-1015. The fineness is a mass (g) per 9000 m of fibers, and is a value obtained by measuring the mass of 300 fibers of 30 mm as a set and correcting the water content in the fibers. The strength and elongation were measured according to the method of JIS-L-1015. The dyeability test was conducted using the cationic dye “Diacryl”.
Red GTL-N "(trade name of Mitsubishi Kasei Corporation) and disperse dye" Dianix / Sarmon Red F "
BE "(trade name of Mitsubishi Kasei Corporation) with 2% owf
(On fiber weight, on the weight of f
iber). In the test of hygroscopicity, the fiber dried to a constant weight at 100 ° C. is allowed to stand for 24 hours in an atmosphere of 24 ° C. and 55% RH (relative humidity), and the weight is measured in the atmosphere to increase the weight. Minutes were calculated as% by weight. In addition, the viscosity at 50 ° C. of the above spinning stock solution is shown in Table.
It is shown in FIG.

As shown in Table 1, the hygroscopicity and dyeability of the obtained acrylic fiber tended to be improved with the NVF content. Further, fibers containing NVF at 20 mol% or more tended to slightly shrink, and when NVF was contained at more than 30 mol%, fusion was observed in some of the fibers.

Example 5 AN and N-vinylacetamide were copolymerized at the molar ratios shown in Table 1 and spun in the same manner as in Examples 1 to 4 to produce an acrylic fiber. The results are shown in Table 1.

Comparative Example 3 In Example 1, A / A was used instead of the AN / NVF monomer.
The same tests as in Examples 1 to 4 were performed using the N monomer, and the results are shown in Table 1. As shown in Table 1, AN fibers containing no NVF are poor in hygroscopicity and dyeability, and as compared with the values in the examples, it was found that inclusion of NVF improves these properties. .

Comparative Example 4 A similar test was performed using N, N-dimethylacrylamide instead of NVF of Example 4, and the results are shown in Table 1. As shown in Table 1, the dyeability and hygroscopicity are improved in the same manner as when NVF is contained, but the shrinkage is high,
It turned out to be undesirable.

Example 6 Example 4 was placed in a 100 ml eggplant-shaped flask equipped with a cooling tube.
0.5 g of the fiber obtained in the above and 25 g of a 1.77 (mol / l) aqueous hydrochloric acid solution were added thereto, and heated at 95 ° C. for 4 hours to obtain a modified fiber. The modification ratio of the formamide group in the obtained fiber was 95% as determined from the amount of formic acid generated from the formamide group during hydrolysis.

Example 7 Example 4 was placed in a 100 ml eggplant-shaped flask equipped with a cooling tube.
0.5 g of the fiber obtained in 9.6 g of methanesulfonic acid,
14.9 g of n-butanol was added and heated at 95 ° C. for 4 hours to obtain a modified fiber. Methanesulfonic acid remaining in the fiber was sufficiently removed by washing with water and immersion in water, and then vacuum dried at 50 ° C. for 15 hours. Even after denaturation, the fiber strength hardly changed. The modification ratio of the formamide group in the fiber was 5% as determined from the ratio of the sulfur and carbon contents in the elemental analysis of the obtained fiber.

[0033]

[Table 1]

Note: In the above table, ◎ indicates extremely good dyeing properties,
Indicates that the dyeability is good, Δ indicates that the color is dyed but the color is light, and X indicates that the color is only partially dyed, and that the color unevenness is remarkable. Note: AN = acrylonitrile NVF = N-vinylformamide NVA = N-vinylacetamide DMA = N, N'-dimethylacrylamide

[0035]

According to the present invention, the acrylic fiber containing a secondary amide group not only provides a fiber having improved dyeability and hygroscopicity, but also has a primary amino group by modification of the secondary amide group. It is possible to produce fibers containing a group, and greatly contributes to the field of functional fibers such as ion exchange fibers, chelate fibers, deodorant fibers, antibacterial fibers, and fibers for immobilizing enzymes.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yukino Yamada 1000 Kamoshita-cho, Midori-ku, Yokohama-shi, Kanagawa Prefecture, Mitsubishi Chemical Research Institute (56) References JP-A-49-110920 (JP, A) JP-A-3-220342 (JP, A) JP-A-61-215713 (JP, A) JP-A-51-130323 (JP, A) JP-A-3-193956 (JP, A) A) JP-A-3-167343 (JP, A) JP-A-52-34026 (JP, A) JP-A-1-163208 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) ) D01F 6/38 C08F 220/48 C08F 226/02

Claims (4)

(57) [Claims] 1. The following structural unit (I) is 99.9 to 85 mol%, and the following structural unit (II) is 0.1 to 15 mol%.
Acrylic fiber contained. Embedded image (Wherein, R represents a hydrogen atom or a methyl group) 2. Acrylonitrile 99.9-85 mol%
To N-vinylformamide and / or N-
2. The acrylic system according to claim 1, wherein vinylacetamide is copolymerized at a ratio of 0.1 to 15 mol%, and the obtained copolymer solution is spun in a solvent in which the copolymer solidifies. Fiber manufacturing method. 3. An acrylic fiber obtained by modifying the acrylic fiber of claim 1 in the presence of an acid or a base and modifying 0.1% or more of the structural unit (II). 4. A copolymer containing 99.9 to 85 mol% of the structural unit (I) and 0.1 to 15 mol% of the structural unit (II) is modified in the presence of an acid or a base to form a copolymer. An acrylic fiber obtained from a modified copolymer obtained by modifying 0.1% or more of the unit (II).