JP4471878B2 - Wet exothermic processing method of cellulosic fiber - Google Patents

Description

  The present invention relates to a wet exothermic processing method for cellulosic fibers.

  It is known that when water molecules are adsorbed on the hydrophilic functional group of the fiber, heat of adsorption is generated, and the heat of adsorption is integrated to generate heat in the fiber. Conventionally, various fiber processing techniques for promoting such a moist exothermic effect have been proposed.

  For example, a cellulosic fabric is treated with a mixed aqueous solution in which a water-soluble substance having a hydroxyl group, an amino group and / or a carboxyl group in the molecule is mixed and dissolved in water, followed by heat treatment. A cellulose-based fabric processing method has been proposed (Patent Document 1).

  Also, for example, a cellulosic fiber that is adhered and / or impregnated with a polycarboxylic acid having at least three carboxyl groups in the molecule, then heat-treated, and optionally soaped with a basic aqueous solution of an alkali metal, A hygroscopic exothermic cellulose fiber in which the polycarboxylic acid content and the salt-type carboxyl group content in the cellulose fiber are in a specific range has been proposed (Patent Document 2).

In addition, for example, a wet exothermic processing method for a cellulose fiber, comprising a step of attaching and curing a polycarboxylic acid and / or a partial salt thereof to the cellulose fiber and then treating with an aqueous solution of an organic acid or an inorganic acid. Is known (Patent Document 3).
JP 2000-178881 A JP 2000-256962 A Japanese Patent Laid-Open No. 2004-36025

  However, these technologies have insufficient wet heat generation performance and washing durability, and problems such as texture hardening and discoloration during processing. In particular, in the technique of Patent Document 1, formaldehyde is generated and there is a problem in safety.

  An object of the present invention is to provide a wet exothermic processing method for cellulosic fibers that can impart sufficient wet exothermic performance and washing durability and does not cause problems such as hardening of the texture and discoloration during processing.

  The present invention relates to a wet exothermic processing method for cellulosic fibers, characterized in that an aliphatic saturated dicarboxylic acid is adhered and cured to cellulosic fibers, and the pH of the fibers is adjusted to 5.0 to 8.0.

  According to the wet exothermic processing method of the present invention, excellent wet exothermic performance and washing durability can be imparted without causing problems such as hardening of the texture and discoloration during processing. Further, since the method of the present invention does not generate formaldehyde, it is excellent in safety.

  In the wet exothermic processing method for cellulosic fibers of the present invention, an aliphatic saturated dicarboxylic acid is first attached and cured to the cellulosic fibers. Specifically, a cellulose fiber is impregnated with a solution containing an aliphatic saturated dicarboxylic acid (hereinafter referred to as a drug compounding solution), the aliphatic saturated dicarboxylic acid is attached to the cellulose fiber, and then the cellulose fiber is heated. . As a result, an ester bond is formed between the hydroxyl group of the cellulosic fiber and one carboxyl group of the aliphatic saturated dicarboxylic acid. As a result, the other carboxyl group that does not contribute to the formation of the ester bond in the aliphatic saturated dicarboxylic acid is cellulose. It is effectively introduced into fiber.

  In the present invention, the cellulosic fibers are not particularly limited. For example, natural celluloses such as cotton and hemp, viscose rayon, copper ammonia method rayon, regenerated cellulose such as polynosic, and purified cellulose such as tencel can be used. As blended, mixed twisted, interwoven, and knitted fabrics of these cellulosic fibers and synthetic fibers (eg, polyester, polyamide, etc.), cellulosic fibers, or cellulosic fibers and animal fibers (eg, wool, silk, etc.) Cellulosic fibers are also subject to processing. The form of the cellulosic fiber is not limited to the form of the fiber itself, and may be a form of yarn, cotton, woven fabric, knitted fabric, non-woven fabric, or the like made of such a fiber, or may have a product form. .

  In the aliphatic saturated dicarboxylic acid, only one carboxyl group tends to selectively contribute to the formation of an ester bond, and as a result, the other carboxyl group can be effectively introduced into the fiber. Aromatic or alicyclic saturated dicarboxylic acids generally hardly form ester bonds with cellulosic fibers and do not provide wet exothermic performance. In order to improve the reactivity, it is conceivable to set the heating temperature at the time of curing high, but it is not practical because the cellulosic fiber is significantly damaged and the strength is greatly reduced.

  If a polycarboxylic acid compound having three or more carboxyl groups is used instead of the aliphatic saturated dicarboxylic acid, the reactivity of the carboxyl group is too high. Therefore, any carboxyl group has a strong tendency to form an ester bond with the cellulosic fiber, and the carboxyl group cannot be effectively introduced into the cellulosic fiber, resulting in insufficient wet heat generation performance. In addition, the texture may harden and the strength may decrease.

  In addition, when an unsaturated one is used instead of the aliphatic saturated dicarboxylic acid, wet heat generation performance is hardly obtained, and problems such as hardening of the texture and discoloration during processing occur.

  As the aliphatic saturated dicarboxylic acid, those having 15 or less carbon atoms, particularly those having 1 to 12 carbon atoms are preferably used from the viewpoint of easy formation of ester bonds. Specific examples of such preferable aliphatic saturated dicarboxylic acids include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, malic acid, tartaric acid and the like. Among these specific examples, those having not only two carboxyl groups but also a hydroxyl group are most preferable. Specific examples of such aliphatic saturated hydroxydicarboxylic acids include malic acid and tartaric acid.

  In the present invention, the aliphatic saturated dicarboxylic acid is not only a compound in which both of two carboxyl groups are acid-type carboxyl groups, but also one or both are salt-type carboxyl groups in which a salt is formed. It shall be used in the concept which also includes a compound. Examples of the material that forms a salt with carboxylic acid include alkali metals such as sodium and potassium, alkaline earth metals such as magnesium, calcium, and barium, and ammonium. A compound in which both of the two carboxyl groups are salt-type carboxyl groups usually does not easily form an ester bond with the cellulosic fiber. However, when an acid is added to make part of the acid-type carboxyl group, an ester bond is formed, which can be used. Hereinafter, the carboxyl group is used in a concept including both an acid type and a salt type.

  The adhesion amount of the aliphatic saturated dicarboxylic acid is not particularly limited as long as the object of the present invention is achieved. For example, 0.1 to 30% by weight, particularly 0.5 to 15% by weight based on the cellulosic fiber. % Is preferred. This adhesion amount is the adhesion amount of the aliphatic saturated dicarboxylic acid to the cellulosic fiber. If the adhesion amount is too small, sufficient wet heat generation performance may not be obtained. If the adhesion amount is too large, problems such as hardening of the texture, discoloration during processing, and reduction in strength may occur. Two or more kinds of aliphatic saturated dicarboxylic acids may be used in combination, and in that case, the total adhesion amount may be within the above range. The adhesion amount of the aliphatic saturated dicarboxylic acid to the cellulosic fiber can be calculated by multiplying the aliphatic saturated dicarboxylic acid concentration (% by weight) of the drug formulation liquid by the squeezing rate (%).

  The drug compounding solution is preferably used in the form of an aqueous solution containing water as a solvent from the viewpoint of safety and ease of handling. However, when the aliphatic saturated dicarboxylic acid is hardly soluble in water, it is aliphatic saturated. You may use in the form of the organic solution which contains the organic solvent which can melt | dissolve dicarboxylic acid as a solvent, or the form of the emulsion of the said organic solution and water.

  Any known method such as dipping, pad, spray, coating, etc. can be used for impregnating the compounded solution into the fiber. The concentration of the aliphatic saturated dicarboxylic acid in the drug blending solution and the amount of impregnation of the drug blending solution into the cellulose fiber are not particularly limited as long as the aliphatic saturated dicarboxylic acid can adhere to the cellulose fiber within the above range. In particular, the concentration of the aliphatic saturated dicarboxylic acid in the drug compound solution is too dilute, so that the aliphatic saturated dicarboxylic acid cannot contact (adhere) the cellulose fiber in a sufficient amount, and even if it is too thick, uniform adhesion is difficult. 0.1 to 50% by weight, particularly 0.5 to 20% by weight is preferred.

From the viewpoint of improving the reactivity of the aliphatic saturated dicarboxylic acid to the cellulosic fiber, it is preferable to contain a pH adjusting agent in addition to the aliphatic saturated dicarboxylic acid. Alkaline substances and acid substances can be used as the pH adjuster, and the choice of which substance to use is made according to the type of the aliphatic saturated dicarboxylic acid.
For example, when an aliphatic saturated dicarboxylic acid having two acid-type carboxyl groups is used, an alkaline substance is used as a pH adjuster. As a result, part of the acid-type carboxyl group becomes a salt-type carboxyl group, thereby improving the reactivity of the aliphatic saturated dicarboxylic acid to the cellulose fiber.
For example, when an aliphatic saturated dicarboxylic acid having two salt-type carboxyl groups is used, an acid substance is used as a pH adjuster. Thereby, a part of the salt-type carboxyl group becomes an acid-type carboxyl group, thereby improving the reactivity of the aliphatic saturated dicarboxylic acid to the cellulose fiber.

  Examples of alkali substances include alkali metal hydroxides, carbonates, bicarbonates, monocarboxylates such as formate and acetate, polycarboxylates, phosphates, borates, ammonia, and secondary grades. Examples include amines, tertiary amines, quaternary ammonium salt hydroxides, and the like. Specifically, sodium hydroxide, sodium bicarbonate, sodium carbonate, sodium borate, sodium metaborate, sodium borohydride, sodium silicate, sodium metasilicate, sodium phosphate, sodium metaphosphate, sodium polyphosphate, pyrophosphoric acid Sodium, sodium phosphite, sodium hypophosphite, sodium sulfate, sodium sulfite, sodium thiosulfate, sodium benzenesulfonate, sodium toluenesulfonate, sodium isethionate, sodium formate, sodium acetate, sodium hydroxyacetate, sodium malate And sodium tartrate, sodium citrate, sodium lactate, methylamine, dimethylamine, trimethylamine, and triethylamine. In the above specific examples, compounds in which sodium is replaced by potassium or ammonium can also be used. You may use an alkaline substance individually or in combination of 2 or more types.

  Examples of the acid substance include organic acids such as butanetetracarboxylic acid, citric acid, malic acid, succinic acid, tartaric acid, acetic acid, formic acid, and hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, phosphorous acid, hypophosphorous acid, etc. Inorganic acids.

  The content of the pH adjusting agent in the drug formulation is not particularly limited as long as the object of the present invention is achieved, and is usually 0.0001 to 30% by weight, particularly 0.01 to 10% by weight based on the total amount of the drug formulation %.

As necessary, softeners, functionality-imparting agents (antibacterial agents, deodorants, water repellents, oil repellents, SR processing agents, etc.), texture modifiers (urethane resins, acrylic resins, Additives such as ethylene vinyl acetate resin) can be included. These agents are desirably added to such an extent that the effects of the present invention (particularly, the effect of improving wet heat generation performance and washing durability) are not impaired.
As the softening agent, for example, a silicon softening agent, a polyethylene softening agent, an aliphatic amide softening agent, or the like can be used.

  The curing process is usually performed at 130 to 180 ° C. for 10 seconds to 20 minutes. As a curing method, a conventionally known method such as a baking machine or a far infrared ray can be used.

  A drying process may be performed prior to the curing process, which facilitates the conveyance of the fibers. Moreover, you may pass through the product sewing process mentioned later and a pleat provision process after this drying. When drying, the drying conditions are not particularly limited, and heating is usually performed at 50 to 150 ° C. for 10 seconds to 20 minutes. As a drying method, a conventionally known method such as a hot cylinder or a tenter can be used.

  After the adhesion / curing treatment, the pH of the cellulosic fiber is adjusted to 5.0 to 8.0, preferably 5.5 to 7.5. By controlling the pH of the cellulosic fiber within the above range, there can be obtained an effect that sufficient wet heat generation performance and washing durability can be imparted without causing problems such as hardening of the texture and discoloration during processing. When the fiber pH is less than 5.0, the wet heat generation performance is insufficient. On the other hand, if the fiber pH exceeds 8.0, problems such as processing discoloration and texture hardening occur, which is not practical.

  The pH of the fiber is based on AATCC 81-1989, and the pH of water when the fiber is boiled with water is used.

  The adjustment to the pH is performed by immersing the adhered and cured fiber in an aqueous solution of a pH adjusting agent. As the pH adjuster used here, the same pH adjuster as that contained in the drug compounding solution can be used.

  The selection of whether to use an alkaline substance or an acid substance as the pH adjusting agent for adjusting the pH of the fiber is not particularly limited as long as the pH of the fiber is adjusted within the above range. In the present invention, since the pH of the fiber immediately before pH adjustment is usually 5.0 or less, an alkaline substance is used as the pH adjuster. Furthermore, when the fiber pH after the alkali substance treatment exceeds 8.0, the pH is adjusted again with the acid substance. When pH adjustment cannot be achieved by a single treatment, the pH adjustment treatment may be repeated while adjusting the type and amount of the pH adjusting agent until a predetermined fiber pH is achieved.

  In the present invention, the pH of the fiber immediately before pH adjustment depends on the type of the aliphatic saturated dicarboxylic acid used in the adhesion / curing step, so that the processing conditions of this pH adjustment step, for example, the type and concentration of the pH adjusting agent Etc. may be appropriately determined according to the adhesion and curing conditions.

For example, when an aliphatic saturated dicarboxylic acid in which both two carboxyl groups are in acid form (hereinafter referred to as acid-type aliphatic saturated dicarboxylic acid) alone is used in the adhesion / curing process, it is introduced into the cellulosic fiber. Since the carboxyl group thus formed is an acid type and the pH of the fiber immediately before pH adjustment is relatively small, an alkaline substance is used as a pH adjuster in the pH adjustment step. At this time, the alkali substance concentration in the treatment liquid is appropriately determined according to the type of the substance. For example, when sodium carbonate is used as the alkaline substance, the concentration is 0.0001 to 30% by weight, preferably 0.001 to 20% by weight, and more preferably 0.01 to 10% by weight. The degree of increase in fiber pH can be adjusted by the alkali substance concentration. That is, the higher the alkali substance concentration, the greater the increase in the fiber pH, while the lower the concentration, the smaller the increase in the fiber pH.
When acid type aliphatic saturated dicarboxylic acid is used alone in the adhesion / curing step, the above fiber pH is never achieved when an acid substance is used as a pH adjuster.

The temperature of the aqueous pH adjusting agent solution in the pH adjusting step is not particularly limited, and usually 10 to 80 ° C. is appropriate.
Further, the immersion time is not particularly limited, and usually 5 seconds to 300 minutes is appropriate.

After the pH adjustment step, washing and drying are usually performed.
Washing with water may be sufficiently performed so that the pH adjusting agent remains and the fiber strength does not decrease.
The washing with water may be performed after the adhesion / curing step and before the pH adjustment step.
The drying may be performed under the same conditions and method as the drying described in the adhesion / curing step.

  The method of the present invention may include a product sewing step and a pleating step. In that case, product sewing may be performed before or after the above-described series of processes of the present invention, or may be performed during the above-described processing steps, for example, immediately before or after the curing process. The pleating may be performed at any time after the product is sewn, but it is preferably performed immediately after the product is sewn and immediately before the curing process from the viewpoint of maintaining a good pleat after the processing.

A representative process of the method of the present invention is illustrated below:
[Processing method 1]
First step: Adhesion / curing step,
Second step: pH adjustment step,
Third step: water washing step,
Fourth step: drying step,
5th process: Product sewing process.
[Processing method 2]
1st process: Product sewing process,
Second step: Adhesion / curing step,
Third step: pH adjustment step,
Fourth step: water washing step,
5th process: Drying process.

[Processing method 3]
First step: impregnation adhesion step and drying step in the adhesion / curing step,
2nd process: Product sewing process,
Third step: Curing step in the adhesion / curing step,
Fourth step: pH adjustment step,
5th process: water washing process,
Sixth step: drying step.
[Processing method 4]
First step: Adhesion / curing step,
2nd process: Product sewing process,
Third step: pH adjustment step,
Fourth step: water washing step,
5th process: Drying process.
[Processing method 5]
First step: impregnation adhesion step and drying step in the adhesion / curing step,
2nd process: Product sewing process,
Third step: pleating step,
Fourth step: Curing step in the adhesion / curing step,
5th process: pH adjustment process,
6th step: water washing step,
Seventh step: drying step.

  The treatment such as application of the softening agent can be performed before the wet exothermic processing, or may be performed after the wet exothermic processing.

Example 1
After impregnating 100% cotton knit material (tissue; stool) with the compounded solution shown in Table 1, squeezing with mangle (squeezing rate 100%), drying (130 ° C x 2 minutes), curing (170 ° C x 2 minutes). Further, after washing with water, the mixture was impregnated with a 0.5 wt% sodium carbonate aqueous solution at 20 ° C. for 1 minute (pH adjustment), then washed with water and dried (130 ° C. × 2 minutes) to obtain a wet exothermic fiber product. The squeezing rate is the ratio of the weight of the drug mixture liquid impregnated in the dough immediately after squeezing to the dry dough weight before impregnation.

(Example 2)
Processing was carried out under the same conditions as in Example 1 except that the chemical compounding solution shown in Table 1 was used.

(Example 3)
Processing was performed under the same conditions as in Example 1 except that a T / C mixed knit material (mixing ratio: polyester 65 / cotton 35, structure: smooth) was used.

Example 4
Processing was performed under the same conditions as in Example 1 except that the pH was adjusted with a 1 wt% aqueous sodium carbonate solution.

(Example 5)
Processing was performed under the same conditions as in Example 1 except that the pH was adjusted with a 2 wt% aqueous sodium carbonate solution.

(Comparative Example 1)
Processing was performed under the same conditions as in Example 1 except that the pH was not adjusted.

(Comparative Example 2)
Processing was performed under the same conditions as in Example 1 except that the pH was adjusted with a 1 wt% aqueous sodium hydroxide solution.

(Comparative Example 3)
Processing was carried out under the same conditions as in Example 1 except that the chemical compounding solution shown in Table 1 was used.

(Comparative Example 4)
Processing was carried out under the same conditions as in Example 1 except that the chemical compounding solution shown in Table 1 was used.

(Comparative Example 5)
Processing was carried out under the same conditions as in Example 1 except that the chemical compounding solution shown in Table 1 was used and the pH was adjusted with a 5 wt% aqueous sodium carbonate solution.

(Comparative Example 6)
Processing was carried out under the same conditions as in Example 1 except that the chemical compounding solution shown in Table 1 was used and the pH was adjusted with a 1 wt% aqueous acetic acid solution.

(Evaluation)
The resulting wet exothermic processed fiber product (sample) was evaluated for drug addition rate, fiber pH, wet exothermic performance, washing durability, texture and discoloration during processing.

(1) Drug addition rate The drug addition rate was determined by the following equation.

(2) Fiber pH
The pH of the fiber was measured according to AATCC 81-1989. Details are as follows. Boil 250 ml of ion exchange water in 10 minutes. 10 g of a sample cut into 1 cm square is put in boiling water and boiled for another 10 minutes. Then, after cooling to room temperature and removing the sample, the pH of the residual liquid was measured.

(3) Wet exothermic performance The sample and the unprocessed dough were dried at 60 ° C for 12 hours. Further, it was left in a desiccator at 25 ° C. for 2 hours to make it completely dry. Then, it moved in the atmosphere of 35 degreeC and 90% RH or more, and the time-dependent change of the temperature by wet heat_generation | fever was measured over 10 minutes. ("Data Stocker TRH-DM3" (manufactured by Shinei Co., Ltd.) used). The maximum value of the temperature difference between the sample and the unprocessed fabric at that time was used as an evaluation scale for wet heat generation.

(4) Durability for washing Wet exothermic evaluation was performed on the sample after 10 times of washing (based on JIS L0217 103 method).
(5) Texture The texture of the sample after processing was evaluated by touch.
○: Flexible;
X: Hard.
(6) Discoloration at the time of processing The degree of discoloration was visually evaluated for the samples before and after the processing.
○: No discoloration;
×: Discolored.

  The wet exothermic processing method of the present invention can be applied to all forms such as yarns, woven fabrics, knitted fabrics and non-woven fabrics as long as they contain cellulosic fibers. The processed product processed by the method of the present invention is useful for applications such as clothing and bedding.

Claims (2)

After attachment and curing of an aliphatic saturated dicarboxylic acid having two acid type carboxyl groups in cellulosic fibers, and characterized in adjusting the pH of the fibers to 5.0 to 8.0 using an alkali substance A wet exothermic processing method for cellulosic fibers.   The wet exothermic processing method for cellulosic fibers according to claim 1, wherein the aliphatic saturated dicarboxylic acid is malic acid or tartaric acid.