JPH0765269B2 - Method of modifying synthetic fibers - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for uniformly and economically modifying synthetic fibers with high reaction efficiency.

(Prior Art) Conventionally, as a method for efficiently graft-polymerizing a hydrophilic vinyl monomer onto a hydrophobic synthetic fiber, there are JP-B-59-5126 and JP-A-51-87592.

The former relates to a monomer composition for a two-step method in a bath in which graft polymerization is carried out after activation pretreatment, but it is uneconomical because it requires two steps of activation pretreatment and graft polymerization. The latter relates to a one-step method in a bath that does not require pretreatment for activation, but such a dipping heating method in a bath has a large amount of unreacted monomer and the graft reaction efficiency is not high, so that a large amount of homogenization occurs in the bath. There is also the problem of polymer contamination of processing machines, and also of wastewater.
Therefore, it is hard to say that it is economical overall.

(Means for Solving the Problems) In order to solve the above problems, the method for modifying synthetic fibers of the present invention has the following constitution. That is, in a method of modifying a synthetic fiber by graft-polymerizing a hydrophilic vinyl monomer, a quaternary ammonium salt type surfactant, a graft polymerization initiator and an aqueous mixture of a hydrophilic vinyl monomer are applied to the synthetic fiber. After that, it is sealed with a vinylidene chloride film and heated, which is a method for modifying synthetic fibers.

(Explanation of Means) The synthetic fiber as referred to in the present invention is a fiber made of a general fiber-forming synthetic resin, and includes, for example, polyalkylene terephthalate fiber, polyamide fiber, polyolefin resin, polyacrylonitrile fiber and the like. Further, it includes fibers made of these modified polymers, or a mixture thereof, or a mixed fiber of various forms in which natural fibers are used in combination. The form of these synthetic fibers may be tow, yarn, knitted fabric, non-woven fabric or the like.

The quaternary ammonium salt type surfactant referred to in the present invention is
Generally, it is commercially available as a cationic surfactant, for example, tetraalkylammonium halide, trialkylbenzylammonium halide, tetraalkylpicolinium halide, trialkylbenzylpicolinium halide, tetraalkylpyridinium halide. Examples thereof include salts and halogenated trialkylbenzylpyridinium salts, and the alkyl groups possessed by these include methyl groups to stearyl groups, and halogens include chlorine and bromine, but are not limited thereto.
These quaternary ammonium salt type surfactants are added for the purpose of stabilizing the solution, and they may be used alone or in combination of two or more kinds.

With other anionic, nonionic, and zwitterionic type boundary agents, it is difficult to obtain a stable aqueous mixed solution, and layer separation occurs in a short time, and uniform reaction cannot be performed. However, there are some that form a stable emulsion dispersion to a certain extent by adding a considerable amount (40% or more). However, adding a large amount of such a surfactant is not only uneconomical, but also increases the efficiency of graft polymerization. It causes deterioration, foaming during cleaning, and various problems.

The hydrophilic vinyl monomer referred to in the present invention is a compound which is usually applied to graft polymerization and contains at least one polymerizable unsaturated group, and can be applied regardless of the molecular weight.

Examples of such a monomer include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and itaconic acid, and unsaturated amides such as acrylamide, methacrylamide, N-methylol acrylamide and vinylpyrrolidone, and vinylphosphone. Examples include unsaturated phosphorus compounds such as acids, and various unsaturated compounds such as unsaturated aromatic compounds such as vinylsulfonic acid and styrenesulfonic acid. In the present invention, derivative compounds of these monomers can also be applied. Examples of such derivative compounds include various compounds obtained by adding ethylene oxide to the above-mentioned monomers, such as polyethylene glycol monoacrylate, polyethylene glycol dimethacrylate, and acrylamide ethylene oxide adduct, but are not limited to these monomers. There is no need, and in short, any compound containing a polymerizable unsaturated group can be applied as the monomer of the present invention. These monomers can be applied alone or in combination of two or more.

Examples of the graft polymerization initiator in the present invention include, for example,
Examples thereof include radical polymerization initiators such as benzoyl peroxide and azobisisobutyronitrile, but are not limited thereto.

In the present invention, it is not particularly necessary to add a fiber swelling agent, but it is possible to add a fiber swelling agent in order to obtain higher graft polymerization efficiency. As a fiber swelling agent,
Compounds such as chlorobenzene type, phenol type, and benzoic acid type can be applied.

The present invention maintains an extremely homogeneous and stable aqueous mixture containing a hydrophilic vinyl monomer, a graft polymerization initiator, and optionally a fiber swelling agent, and after applying the aqueous mixture to a synthetic fiber by padding. , Grafting is carried out in a single processing step by heat treatment,
At that time, in order to keep the aqueous mixed solution in an extremely uniform and stable state, it is characterized in that a quaternary ammonium salt type surfactant is added. It is preferable to adjust the monomer concentration of the aqueous mixture to a range of 5% to 70%. Below this range, the stability of the solution will drop significantly, and the grafting efficiency will also drop. On the other hand, if the content exceeds this range, the graft efficiency will decrease, which is considered to be due to the decrease in the carrier effect of water. Since the concentration of the quaternary ammonium salt type surfactant varies depending on the monomer concentration, it is preferable to add the quaternary ammonium salt type surfactant in a necessary minimum amount in terms of grafting efficiency and economy. The concentration range of the surfactant is 1% to
20%. Graft polymerization initiator concentration is 0.1% to 3.0%
Is the range. If it deviates from this range, the generation of homopolymer will increase and the grafting efficiency will decrease. Further, as described above, the fiber swelling agent is not particularly required, but when added, the concentration is preferably 5% or less as a pure product. If this is exceeded, the grafting efficiency will decrease.

The order of adding the hydrophilic vinyl monomer and the graft polymerization initiator is not particularly limited, but it is preferable to first dissolve the graft polymerization initiator in the hydrophilic vinyl monomer and then add another water or quaternary ammonium salt type interface. It is good to add an activator.

The required amount of the water-based mixed solution obtained by adjusting in this way is added to the synthetic fiber by a padding method or the like. As another application method, a method of squeezing with a centrifugal dehydrator after spraying, coating, dipping, or the like can be considered, but it can be appropriately selected depending on the form of the object to be treated, the required application amount and the like.

The object to be treated to which the aqueous mixed solution containing such a monomer is applied is sealed with a vinylidene chloride film and then transferred to a heating system. If not sealed with a vinylidene chloride film, the hydrophilic monomer will evaporate and the grafting efficiency for the fiber will be significantly reduced. When the object to be processed transferred to the heating system is allowed to stand and subjected to heat treatment, the processing solution usually moves downward due to its own weight, and preferably the solution does not move due to centrifugal force. It is preferable that the liquid is kept in a state where the liquid movement is small by rotating the liquid to a certain degree.

As the heating means, a usual heating mechanism can be applied, but preferably heating by microwaves or a combination of steam and microwaves can be selected in view of the rate of temperature rise and ease of control.

In the case of this heating method, the temperature rising rate and the maximum temperature differ depending on the requirements such as the frequency, the type and amount of the dielectric material, and the moving speed of the object to be processed. Maximum temperature can be regulated.

Graft polymerization initiation temperature varies slightly depending on the type of polymerization initiator and the type of monomer, but is usually 80 ° C or higher, preferably 10 ° C.
Temperature conditions up to 180 ℃ are applied even if higher than 0 ℃.
The modified synthetic fiber obtained by graft-polymerizing the unsaturated carboxylic acid monomer is further subjected to substitution treatment with an alkali metal such as sodium or potassium by a conventional method to obtain a hydrophilic property such as antistatic property or hygroscopic property. Further improvement can be expected, and antibacterial performance can be imparted by substitution treatment with a quaternary ammonium salt.

(Example) Example 1 0.5 g of organic peroxide (NIPPER NOF CORPORATION, Niper MT-80) as a graft polymerization initiator, 1 g of monochlorobenzene as a swelling agent of polyethylene terephthalate fiber, 30 g of methacrylic acid as a hydrophilic vinyl monomer, and a fourth -Grade ammonium salt-type surfactant (Daiichi Kogyo Seiyaku Cationogen AN Super)
3 g was diluted with water to prepare 100 g of an aqueous mixed solution.

Next, a polyethylene terephthalate-processed yarn fabric (Toray # 2525) with a scouring intermediate set was dipped in this aqueous mixture, squeezed with a mangle, wound on a roll, and then sealed with a vinylidene chloride film. At this time, the pick-up rate was 70% with respect to the weight of the textured yarn woven fabric. Next, this processed yarn woven fabric is put in a microwave treatment device (Ichikin's Apollo PET), heated and irradiated with 100 ° C steam and microwave for 5 minutes,
After washing with water, washing with water, and drying, the rate of weight increase with respect to the initial weight of the textured yarn fabric was determined.

The reaction efficiency of the monomer corresponding to the weight increase rate was calculated as follows, taking the pickup rate into consideration. The results are shown in Table 1.

Monomer reaction efficiency = Grafting efficiency Grafting efficiency (%) = [weight increase rate / 0.7 × monomer concentration] × 100 [wherein, weight increase rate:% by weight, monomer concentration:% by weight] Comparative Examples 1 and 2 Instead of the quaternary ammonium salt type surfactant, a nonionic surfactant (Neugen ET16 manufactured by Dai-ichi Kogyo Seiyaku)
0) 5 g was added (Comparative Example 1).

Next, 5 g of an anionic surfactant (Prysurf A217E manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added instead of the quaternary ammonium salt type surfactant of Example 1 (Comparative Example 2).

In Example 1, a uniform and stable aqueous mixture was obtained,
In Comparative Examples 1 and 2, the mixed solution was separated into two layers and was unsuitable as a pad solution.

Comparative Example 3 2 g of a graft polymerization initiator (Niiper MT-80 manufactured by NOF CORPORATION),
Polyethylene terephthalate fiber swelling agent; monochlorobenzene 10 g, as an emulsifier (Neugen EA16 manufactured by NOF CORPORATION)
0) 5 g, 20 g of a 1: 1 (weight) mixture of acrylic acid and methacrylic acid as hydrophilic vinyl monomers was diluted with water to make 1000 ml. Next, add 300 ml of this solution to 10 g of polyethylene terephthalate-processed yarn fabric (Toray # 2525) with a refined intermediate set.
Was immersed and heat-treated at 100 ° C. for 60 minutes. Next, after washing with hot water, washing with water, and drying, the rate of weight increase relative to the initial woven fabric was determined, and the grafting efficiency was determined by the following formula. The results are shown in Table 1.

[In the formula, weight increase rate: weight ratio] As is clear from Table 1, the woven fabric graft-treated with the aqueous mixture obtained in Example 1 in one step showed high graft efficiency, but the graft-polymerized one-step treatment in the bath was compared. The grafting efficiency of Example 3 was low. In addition, Comparative Example 1 in which a nonionic surfactant was used instead of the quaternary ammonium salt type surfactant and Comparative Example 2 in which an anionic surfactant was used did not form a stable water-based mixed solution and were subjected to one-step graft polymerization. I didn't want to do anything.

Comparative Example 4 Grafting efficiency was measured when microwave heating was performed under the same conditions as in Example 1 except that the film was immersed in an aqueous mixed solution, squeezed with a mangle, wound with a roll, and not sealed with a vinylidene chloride film. Was extremely low at 10.7%.

(Effects of the Invention) The present invention can uniformly and extremely economically modify synthetic fibers with excellent reaction efficiency. Also, when heating,
It is possible to prevent the hydrophilic monomer from scattering and prevent the graft efficiency from decreasing.

Claims (2)

[Claims] 1. A method for graft-polymerizing a synthetic vinyl fiber with a hydrophilic vinyl monomer to modify the synthetic fiber, wherein a quaternary ammonium salt type surfactant, a graft polymerization initiator, and an aqueous mixed solution of the hydrophilic vinyl monomer are added to the synthetic fiber. A method for modifying a synthetic fiber, which comprises sealing with a vinylidene chloride film, and heating after applying the same to the above. 2. The method for modifying synthetic fibers according to claim 1, wherein the heating means is a microwave or a combination of steam and microwave.