JP2003201672A - Water- and oil-repelling fiber structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water- and oil-repelling fiber structure containing cotton fibers and having high durability unattainable by conventional techniques for a cotton-containing fiber structure. <P>SOLUTION: The fiber structure contains cotton single fibers crosslinked or filled in its inside and/or surface with (A) a processing agent having ≥2 reactive groups reactive with the cotton fiber or with the agent A and (B) a compound having ≥2 active hydrogen groups reactive with (A). The outermost layer of the crosslinked fiber is coated with a reaction product of (C) a water- and oil-repelling agent with (D) a crosslinking compound reactive with (C). The cotton single fiber on the surface of the fiber structure is not fibrillated by repeating the washing of the structure 50 times by a method in conformity to JIS L0217-1976-103. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fibrous structure which has been subjected to a water / oil repellent treatment, and more particularly to a water / oil repellent property against washing and dry cleaning, and furthermore, against friction when worn. The present invention relates to a fibrous structure containing cotton fibers having improved durability. 2. Description of the Related Art Conventionally, as a method for imparting a high degree of water and oil repellency to a fiber structure such as a cloth, a water and oil repellent agent made of a fluorine compound is applied to the surface of the fiber to form a water and oil repellent film. Has been carried out. However, since these processing agent films are brittle and have poor adhesion to the fiber, the processing agent film is easier than the fiber due to washing and dry cleaning, and even friction between cloths and other objects when worn. And the water- and oil-repellency is greatly reduced. [0003] In particular, with respect to water repellency, cotton fiber, which is a hydrophilic fiber, has particularly poor durability, and the following proposals have been made to improve the durability. That is, a method of mixing a blocked isocyanate-based crosslinking agent with a fluorine-based water / oil-repellent finishing agent containing an active hydrogen group (JP-A-54-13348).
No. 6), a method of forming a base layer of a blocked isocyanate compound on the fiber surface to improve the adhesion of a fluorine-based water / oil repellent agent (Japanese Patent Application Laid-Open No. 54-139,641).
A method of condensing and crosslinking on the fiber surface using a fluorine-based water / oil repellent agent containing a condensable methylol group (JP-A-59-13)
No. 0374), a method of treating with a water-based fluorine-based water / oil repellent agent and then treating with a solvent-based fluorine-based water / oil repellent agent (Japanese Patent Application Laid-Open No. S60-151380). Method of copolymerizing on the surface (JP-B-63-
No. 14117). However, these methods do not have sufficient durability of water repellency, and when a high durability test such as washing 50 times is performed, the water repellency is almost lost. SUMMARY OF THE INVENTION The present invention provides a highly durable water- and oil-repellent fiber structure which has not been obtained by the prior art for a fiber structure containing cotton fibers. It is. The inventors of the present invention have conducted intensive studies on the cause of the decrease in water repellency due to washing and friction of a cotton fiber fabric water-repellent with a fluorine-based water / oil repellent agent. Not only due to the drop of the water processing agent, but also due to washing and friction, the cotton single fibers on the fabric surface are fibrillated, and the cellulose surface not covered with the water repellent agent appears on the single fiber surface. It has been found that the aqueous properties decrease. [0006] From the above, the present inventors, in order to dramatically improve the durability of the water-repellent and oil-repellent finishing of the fibrous structure containing cotton fibers, to remove the water- and oil-repellent finishing agent from the fiber. Prevention alone is not sufficient, and the present invention was deemed necessary because it was necessary to prevent the fibers themselves from being fibrillated by washing or friction between fabrics. That is, the present invention relates to a processing agent (A) or (A) in which the inside or / and the surface of a cotton fiber has two or more reactive groups capable of reacting with the cotton fiber. ) And (A) are crosslinked or filled with a compound (B) having two or more active hydrogen groups capable of reacting with water, and the outermost layer surface of the cotton fiber is mainly composed of a water- and oil-repellent agent (C) or (C). ) Is a fiber structure having a single cotton fiber coated with a film of a reaction product with a crosslinkable compound (D) capable of reacting with the crosslinkable compound (D), and the fiber structure is defined by JIS L0
A water-repellent and oil-repellent fibrous structure characterized in that the cotton single fiber on the surface of the fibrous structure is not fibrillated after 50 times of washing treatment according to the method 103 of 217-1976. [0008] In cotton fibers, the inside of a single fiber is not uniform, but forms various microstructures. The cotton single fiber is composed of a primary wall which contains a lot of waxy and pectic substances and is removed in the refining process, and a secondary wall mainly composed of cellulose. The secondary wall is also
It forms a higher-order structure composed of fine cellulose structures called lamella, fibrils, microfibrils, and elementary fibrils, and there are minute voids between the structures. Therefore, when a large external force is applied due to friction or the like, the fiber structure is not uniformly scraped off, but the fiber structure is torn between lamellas and fibrils, which are large fine structures, and the single fibers are fibrillated. Although the fibrillation of the cotton fibers due to the friction occurs even in a dry state, it is particularly likely to occur when the cotton fibers swell due to water or the like and the gaps between the microstructures are widened. Therefore, when the cotton fibers rub against each other and the washing machine tub wall or the like in a water-swelled state due to washing or the like, and the fabric surface is subjected to strong friction, the single fibers on the fabric surface tend to fibrillate. The fibrillation caused by this washing is so small that it cannot be seen by the naked eye. However, when the surface of the cotton fabric after washing is magnified 500 times or more with a scanning electron micrograph, it is less than several μm from the surface of the single fiber. It can be seen that fibrils in the form of fibers are generated as if the fibrous tissue was turned up. In order to prevent the water and oil repellency from decreasing due to the fibrillation, it is effective to increase the friction durability of the single fiber so as not to fibrillate due to friction. As a method for improving the friction durability of a single fiber in order to prevent fibrillation due to friction, the active hydrogen groups of the cotton fiber itself are cross-linked using a cross-linkable compound to cross-link the inside of the single fiber or the fiber surface. Or a method of forming a tough film on the fiber surface. First, the active hydrogen groups of the cotton fibers themselves are cross-linked by using a cross-linkable compound to crosslink the inside or surface of the single fiber to improve friction durability. One method is to use two reactive groups that react and cross-link with the active hydrogen groups. There is a method in which the compound having the above is penetrated into the inside of the single fiber or applied to the fiber surface, and crosslinked and cured by heat treatment or the like. Examples of the compound having two or more reactive groups capable of reacting and crosslinking with an active hydrogen group include formalin, N-methylol compounds, ketone resins, acetal resins, isocyanate compounds, epoxy resins, active vinyl compounds, polycarboxylic acid compounds and the like. Available. Examples of the N-methylol compound include urea formaldehyde resins such as dimethylol urea and urea formalin condensate, melamine formaldehyde resins such as trimethylol melamine and hexamethylol melamine, dimethylol ethylene urea, dimethylol dihydroxy ethylene urea, dimethylol propylene Urea, dimethylol butylene urea, dimethylol urone, dimethylol alkyl triazine, tetramethylol acetylene urea,
Cyclic urea type resins such as 4-methoxy-5-dimethylpropylene urea, alkyl carbamate resins such as dimethylol alkyl carbamate, dimethylol hydroxyethyl carbamate, N-methylol acrylamide polymers and other acrylic and methacrylic compounds. Polymers and the like can be used. Further, methyl ether compounds of the above N-methylol compounds can also be used. As the ketone resin, an acetone formaldehyde resin or the like can be used. As the acetal resin, glycol acetal, pentaerythritol bisacetal and the like can be used. As the isocyanate compound, a compound having two or more isocyanate groups in which an isocyanate group is blocked by an oxime compound such as sodium sulfite or methyl ethyl ketoxime can be used. Examples of the epoxy resin include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, polyglycerin polyglycidyl ether, trimethylolpropane triglycidyl ether, and sorbitol. Glycidyl ether compounds such as polyglycidyl ether and sorbitan polyglycidyl ether can be used. Among these crosslinkable compounds, those having a relatively large molecular weight are preferred in order to efficiently crosslink the gaps between the microstructures (between lamellas and fibrils) or the fiber surface inside the single fiber. In this sense, a crosslinkable compound having a small molecular weight, whose molecular weight becomes large at the time of crosslinking by self-condensation, is particularly effective in the present invention. It is also effective to use a compound having another active hydrogen group in combination to lengthen the crosslinked chain to crosslink the fine structure gap, or to form a crosslinked film which is also crosslinked with the fiber on the fiber surface. As the compound used in combination to extend the crosslinked chain or to form a crosslinked film on the fiber surface, a compound having two or more active hydrogen groups capable of crosslinking with the crosslinking compound can be used. Examples of the compound include a polyhydric alcohol compound and a polymer compound having two or more active hydrogen groups. Examples of the polyhydric alcohol compound include polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, trimethylolpropane and pentaerythritol, natural sugars such as glucose, sorbitan and sorbitol, and ethylene oxide and propylene. Oxide adducts and the like can also be used. Examples of the high molecular compound having two or more active hydrogen groups include polyalkylene oxide compounds, polyvinyl alcohol, acrylic copolymers having a hydroxyl group in the side chain, starch, and natural polysaccharides such as carboxymethyl starch and the like. Modified products, such as sodium alginate, carboxymethylcellulose, methylcellulose, hydroxyethylcellulose, and hydroxypropylcellulose, can be used. These polyhydric alcohol compounds and high molecular compounds need to have a small molecular size in order to enter between the microstructures inside the swollen single fiber and play a role of a cross-linking chain between the microstructures, Is desirably tens of thousands or less. On the contrary, in order to form a crosslinked film with the crosslinkable compound on the fiber surface, it is preferable that the molecular weight is large. When the above-mentioned crosslinkable compound and the compound having an active hydrogen group are applied to the fiber, if the purpose is to crosslink the inside of the fiber, the cellulosic fiber is used to penetrate the compound into the inside of the fiber. It is necessary to dissolve and apply by using a solvent that swells. The solvent for swelling the fibers is not particularly limited, but for example, water is preferable. Next, as another method of preventing fibrillation due to friction, a method of forming a tough film on the fiber surface includes applying a film-forming polymer compound to the fiber surface to form a film, A method of forming a film by imparting a hydrophilic compound and polymerizing on the fiber surface. As a method for forming a film by applying a film-forming polymer compound to the fiber surface, the film-forming polymer is dissolved, dispersed, or emulsified in water or various solvents, applied to the fiber surface, and dried by heat or the like. And a method of curing and forming a film. Examples of the film-forming polymer include vinyl polymer, acrylic polymer, urethane polymer, polyalkyl oxide polymer, polyester polymer, polyamide polymer, epoxy polymer, and cellulose polymer. Molecules can be used. At this time, for the purpose of improving the durability of the polymer compound film, the polymer film may be cross-linked by using a cross-linkable compound, or the polymer film and the cellulose fiber may be cross-linked. As the crosslinkable compound, N-methylol compound, ketone resin, acetal resin, isocyanate compound,
Epoxy resin and the like can be used. As a method of forming a film by providing a polymerizable compound and polymerizing on the fiber surface, an acrylic monomer,
A method can be used in which a methacrylic monomer or other compound containing a polymerizable unsaturated group is applied to the fiber surface and then polymerized by heat, ultraviolet light, radiation, or the like. At this time, other polymer compounds and crosslinkable compounds can be used in combination for the purpose of improving the film strength and further improving the adhesiveness with the cellulose fiber and the water repellent. In order to efficiently carry out the crosslinking reaction or the polymerization reaction of the compound used for the purpose of preventing the fibrillation of the fiber, additives such as a catalyst and an initiator depending on each compound may be used. Further, in order to reduce the friction on the fiber surface and to make the texture after processing preferable, a silicon-based or aliphatic-based smoothing agent and a softening agent can be used in combination. The amount of these compounds applied to the fiber structure is desirably used within a range that does not significantly impair the texture of the fabric, and the amount applied to the fiber structure is within 20%, preferably within 10%, based on the fiber weight. is there. In order to obtain the durable water- and oil-repellent fibrous structure of the present invention, it is necessary to perform the above-described processing for preventing fibrillation and water- and oil-repellent processing. However, the processing for preventing fibrillation may be performed before the water / oil repellent processing or at the same time as the water / oil repellent processing. As the water- and oil-repellent agent usable in the present invention, those obtained by dissolving, dispersing or emulsifying a generally used fluorine-based or silicon-based compound in a water or solvent can be used. Among them, a fluorine-based water- and oil-repellent agent is desirable in order to obtain high water- and oil-repellency. In order to improve the adhesion between the fluorine-based water- and oil-repellent agent and the film formed on the fiber surface to prevent the formation of cellulose fibers or fibrillation, the water- and oil-repellent agent is crosslinked with blocked isocyanate. It is more preferable in the present invention to use an agent in combination. The processing agent for preventing fibrillation and the processing agent for water- and oil-repellent treatment used for obtaining the durable water- and oil-repellent fiber structure of the present invention are made of fiber. As a method for applying to a structure, a dipping method, a pad method, a coating method, a spray method, or the like can be used.
Among these, the pad method is preferable in order to uniformly apply the entire fiber. Next, the most important method for determining fibrillation in the present invention will be described. The term "fibrillation" as used herein means that a single fiber is subdivided due to a phenomenon such as splitting of a single cotton fiber into two or more fibers or separation of a fiber structure from the surface of a single cotton fiber. The determination of fibrillation can be easily performed by the following method. That is, the surface of the fibrous structure containing the water-repellent cotton fibers was photographed with a scanning electron microscope (about 500 times), and then the fibrous structure was subjected to a household washing test (JIS L0217-1976 103 method). Later, the surface is again photographed with a scanning electron microscope. Then, by comparing the two photographs before and after washing, it is determined whether or not fibrillation has occurred by washing. Here, the photographing of the surface before washing is performed in order to avoid the influence of fibrils generated by a step (for example, a raising treatment, an enzyme treatment, etc.) before the water-repellent processing. Here, in order to clearly determine the fibrils due to washing, the site of the observed fabric sample is important. The fibrillation of cotton fibers by washing is most likely to occur at the portion of the fabric surface where the yarn is most raised, that is, at the center of the warp weave in a woven fabric and at the top of the yarn loop in a knitted fabric. Therefore, it is necessary to observe this part when determining fibrillation by observation with a scanning electron microscope. In order to clearly obtain the effect of improving the water / oil repellency of the fibrous structure according to the present invention, it is necessary that fibrillation does not occur until 50 times after washing. It goes without saying that it is preferable that the number of times that fibrillation does not occur increases. The fiber structure having cotton fibers referred to in the present invention refers to yarns, woven fabrics, knitted fabrics and nonwoven fabrics containing cotton fibers, which are other fibers such as natural fibers other than cotton, synthetic fibers, and regenerated fibers. It can be a mixture with EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. Synthesis of Processing Agent (A) Fluorine Water / Oil Repellent Processing Agent Perfluorooctylethyl acrylate: 80 parts, 2-
Ethylhexyl methacrylate: 8 parts, 2-acryloyloxyethyl-2-hydroxyethylphthalic acid: 7
Parts, methyl methacrylate: 5 parts by emulsion copolymerization in an aqueous solvent, and a fluorine-based water / oil repellent agent (active ingredient: 20%,
Dispersed particle diameter: 0.1 μm, hereinafter abbreviated as FWP). (B) Blocked isocyanate crosslinking agent A blocked isocyanate compound obtained by blocking the isocyanate group of diphenylmethane diisocyanate with methyl ethyl ketoxime is dispersed in water (active ingredient: 30%, dispersed particle diameter: 0.5 μm, hereinafter abbreviated as BNCO), and An isocyanate crosslinking agent was used. Example 1 and Comparative Example 2 Refined, bleached, mercerized cotton twill fabric (80/2 ×
80 / 2-185 × 95 pcs / inch), pad treatment (squeezing rate: 60%) with a pretreatment bath composed of the following water-soluble polymer, crosslinkable compound, and catalyst After drying for 3 minutes, a curing treatment was performed at 160 ° C. for 3 minutes. Thereafter, a water- and oil-repellent agent treatment bath comprising the following fluorine-based water- and oil-repellent agent and a blocked isocyanate crosslinking agent is subjected to pad treatment (squeezing ratio: 60%), dried at 110 ° C. for 3 minutes, and then 160 ° C. For 3 minutes. (Pretreatment processing agent formulation) (Example 1) Polyvinyl alcohol (molecular weight 100,000) 2 parts Methylol urea highly condensed resin (active ingredient: 85%) 5 parts 2-methyl-2-aminopropanol hydrochloride (active ingredient: 20) %) 1 part Ion exchange water 94 parts (Comparative Example 2) Polyvinyl alcohol (molecular weight 15,000) 2 parts Dimethylol dihydroxyethylene urea (active ingredient: 50%) 10 parts Magnesium chloride aqueous solution (active ingredient: 20%) 1 Part 90 parts of ion-exchanged water (formulation of water- and oil-repellent finishing agent of Example 1 and Comparative Example 2) 5 parts of FWP 2 parts of BNCO 93 parts of ion-exchanged water Comparative Example 1 Same cotton as Example 1 and Comparative Example 2 Pad treatment (squeezing rate: 60%) using the same water- and oil-repellent treatment prescription as in Example 1 and Comparative Example 2, dried at 110 ° C. for 3 minutes, and then cured at 160 ° C. for 3 minutes It was carried out. Evaluation method Fibrillation determination method A test cloth subjected to a water-repellent treatment was subjected to a warp × width: 20 × 20 cm.
Cut into squares for home washing tests (JIS L021)
7-1976 103 method), the washing process is performed continuously,
Samples were taken every 10, 20, 30, 40, and 50 washes, and three warp portions were photographed at a magnification of 500 times on the surface of the woven fabric using a scanning electron microscope. The three photographs were compared with those before washing, and fibrillation was determined based on (Table 1). [Table 1] Water repellency evaluation method JIS L 1092-1986
Initial and home washing tests (JIS) of the work cloths after the water and oil repellency treatment of Example 1, Comparative Examples 1 and 2 by the spray test of
L0217-1976 103 method) 10, 20, 30, 40,
The water repellency after 50 times was evaluated. Evaluation of water repellency (Table 2)
It went based on. [Table 2] Tables 3 and 4 show the fibrillation and water repellency of Example 1 and Comparative Examples 1 and 2 at the initial stage and after washing. As compared with the comparative example, the water repellency in the washing test of Example 1 of the present invention was improved even when water repellency was performed using the same fluorine-based water / oil repellent agent and blocked isocyanate crosslinking agent. It can be seen that it is greatly improved. Also, there is a high correlation between the decrease in water repellency due to washing and the fibrillation, and it can be seen that even when the same water / oil repellent is used for water repellency, the less the fibrillation, the better the water repellency. [Table 3] [Table 4] The water-repellent and oil-repellent fiber structure containing the cotton fiber of the present invention is more resistant to washing, dry cleaning and friction when worn than the conventional water-repellent and oil-repellent fiber structure containing the cotton fiber. Durability is remarkably excellent, and processing can be performed by using a conventionally used facility without requiring a new facility.

Claims (1)

Claims 1. A processing agent (A) or (A) or (A) wherein the inside or / and the surface of the cotton fiber has two or more reactive groups capable of reacting with the cotton fiber. Crosslinked or filled with the compound (B) having two or more reactive hydrogen groups capable of reacting, and the outermost layer surface of the cotton fiber is mainly reactive with the water and oil repellents (C) and (C). A fibrous structure having a cotton single fiber coated with a film of a reaction product with the reactive compound (D), the fibrous structure being subjected to a washing process 50 times according to the 103 method of JIS L0217-1976, A water- and oil-repellent fibrous structure, characterized in that the single cotton fibers on the surface of the structure are not fibrillated.