JP4391379B2 - Water-repellent high-strength synthetic fiber structure and water-repellent processing method - Google Patents

Description

  The present invention relates to a water repellent processing technique for a fiber structure mainly composed of high-strength synthetic fibers such as para-aramid fibers. More specifically, the present invention relates to a water-repellent high-strength synthetic fiber structure and a water-repellent processing method, which are provided with water repellency having durability against washing, dry cleaning, abrasion, and the like.

  Conventionally, as a method for imparting water repellency to synthetic fibers such as polyester fibers and nylon fibers, a method of treating fibers with a compound having a low surface energy such as a silicone compound or a fluorine-containing compound and coating the fiber surface with the compound is known. It has been. At this time, for the purpose of imparting durability against washing, dry cleaning, abrasion, etc., a method using a silicone compound and a silane coupling agent (Patent Document 1), a fluorine-containing compound and a melamine resin (Patent Document 2), or Various studies have been made, such as a method using a polyfunctional isocyanate (Patent Document 3), a method using a silicone compound and a fluorine-containing compound separately (Patent Document 4). I give it.

  However, when the above method is applied to high-strength synthetic fibers such as para-aramid fibers, there is a problem that the water repellency is remarkably lowered by washing or the like. This is presumed to be due to the high crystallinity of the fibers and the high orientation, which results in poor adhesion to the compound coating and is easy to fibrillate due to physical impact such as washing. As a method for suppressing fibrillation of high-strength synthetic fibers, a method of fixing a cation-exchangeable inorganic compound on the fiber surface and then treating with a cationic compound (Patent Document 5) is also known. Even if the above-mentioned water-repellent processing method is applied to the obtained fiber, a satisfactory durable water-repellent property is not obtained at present.

JP-A-3-249281 Japanese Patent Laid-Open No. 56-118970 JP-A-56-165072 JP 58-208473 A JP-A-1-229875

  The present invention has been made in view of such a current situation, and the object of the present invention is to fabric structures mainly composed of high-strength synthetic fibers such as para-aramid fibers, for washing, dry cleaning, wear, etc. Another object of the present invention is to provide a water-repellent high-strength synthetic fiber structure and a water-repellent processing method, which are provided with water repellency having durability.

  As a result of intensive studies to solve the above problems, the present inventor, as a result, is a coating mainly composed of a product obtained by reacting an organohydrogenpolysiloxane and a metal alkoxide on the fiber surface of a high-strength synthetic fiber structure. It is possible to suppress fibrillation of the fiber by imparting, and to impart a water repellency excellent in durability by imparting a coating containing a fluorine-containing compound as a main component on the upper part. The present invention has been found out and the present invention has been completed based on this finding.

That is, the present invention firstly includes organohydrogenpolysiloxane and
A metal alkoxide having an amino group in the molecule or a metal alkoxide having no amino group in the molecule and an amino group-containing compound;
To produce a reaction product having a cross-linked structure and a molecular weight of 500 to 100,000, and then treating the high-strength synthetic fiber structure with the first treatment liquid containing the reaction product as a main component, A water-repellent processing method for a high-strength synthetic fiber structure, characterized by treating with a second treatment liquid containing a compound as a main component.
Secondly, the present invention provides that the high-strength synthetic fiber structure contains 5 to 100% by weight of at least one high-strength synthetic fiber selected from para-aramid fibers, wholly aromatic polyester fibers, and heterocyclic fibers. It is the method described above, characterized .
The present invention, in a third, high-strength synthetic fiber structures, LOI value, characterized in that it contains 0 to 95 wt% of the fibers is 25 or more as a fiber other than the high strength synthetic fiber, in the manner described above is there.
Fourthly , the present invention is the above method, wherein the metal alkoxide is an alkoxysilane.

  ADVANTAGE OF THE INVENTION According to this invention, the water repellency which has durability with respect to washing | cleaning, dry cleaning, abrasion, etc. can be provided to a high strength synthetic fiber structure, without impairing the physical property of a high strength synthetic fiber. The water-repellent high-strength synthetic fiber structure of the present invention has properties such as high strength, heat resistance, and flame resistance, and is therefore particularly preferably used for applications such as protective clothing and building materials. The protective clothing referred to here includes fire and fire protective clothing, electrical work clothing, welding work clothing, work gloves, bulletproof vests, and the like. Particularly in bulletproof vests, since a large amount of para-aramid fiber is used, there is usually a concern about a decrease in elasticity resistance due to water wetting, but the present invention can prevent a decrease in elasticity resistance due to water wetting. The building materials refer to tent fabrics, membrane structure materials, curing meshes, and the like. Furthermore, it is also suitable for sports apparel applications such as skiing, skating, snowboarding, mountain climbing, orienteering, canoeing, kayaking, and yachting.

Hereinafter, the present invention will be described in detail.
In the present invention, the high-strength synthetic fiber structure means a fiber structure mainly composed of high-strength synthetic fibers, and is a combination of fibers other than high-strength synthetic fibers within a range that does not affect the physical properties. It doesn't matter. Examples of a method for combining high-strength synthetic fibers and fibers other than high-strength synthetic fibers include blended spinning, knitting, knitting, and knitting. The fiber structure means the whole fiber assembly such as tow, yarn, and fabric (woven fabric, knitted fabric, non-woven fabric). The high-strength synthetic fiber structure may be composed of short fibers, may be composed of long fibers (filaments), or may be a combination of these. For example, short fiber fabrics are suitable for fire and fire protection clothing, and long fiber fabrics with high tensile strength are suitable for bulletproof vests.

A high strength synthetic fiber generally refers to a synthetic fiber having a tensile strength of 2.0 GPa or more. Here, the tensile strength of the high-strength synthetic fiber is measured in accordance with JIS L 1013-1999 chemical fiber filament yarn test method (8.5) when the fiber is a long fiber yarn (multifilament yarn). In the case of high-strength synthetic fibers, measurement is performed by adding a twist represented by the following formula to the yarn before measurement in order to eliminate the disturbance of the single fiber and apply stress to each single fiber constituting the yarn. To do.
Tm = K / √D
Where Tm: number of twists (times / m)
K: Twisting coefficient (K = 957)
D: Fineness (tex)
When the fiber is a short fiber (staple), it is measured according to JIS L 1015-1999 chemical fiber staple test method (8.7).
The tensile strength of the fiber is generally expressed in N / tex units, but can be converted into GPa units as follows.
a × ρ (GPa)
Here, a: Tensile strength (N / tex)
ρ: Fiber density (g / cm ³ )
The thickness tex (tex) of the fiber is represented by a fineness indication JIS L 0101-1978 text system.
As a synthetic fiber having a tensile strength of 2.0 GPa or more, a typical example is a para-aramid fiber. Specifically, a polyparaphenylene terephthalamide fiber (for example, Kevlar (manufactured by Toray DuPont Co., Ltd.) Registered trademark)), and copolyparaphenylene-3,4'-diphenyl ether terephthalamide fiber (for example, Technora (registered trademark) manufactured by Teijin Limited). Further, as high-strength synthetic fibers other than para-aramid fibers, wholly aromatic polyester fibers (also referred to as polyarylate fibers; for example, Vectran (registered trademark) manufactured by Kuraray Co., Ltd.), heterocyclic fibers (polyparaphenylenebenzobis) Examples thereof include oxazole fibers (for example, Zylon (registered trademark) manufactured by Toyobo Co., Ltd.). Two or more kinds of these high-strength synthetic fibers may be combined.

  High-strength synthetic fibers discolor due to ultraviolet rays contained in the light when exposed to sunlight, fluorescent light, incandescent light, etc. for a long time compared to general clothing fibers such as nylon fiber and polyester fiber (both are synthetic fibers). Easy to do. In addition, the strength is easily deteriorated by ultraviolet rays, particularly ultraviolet rays in sunlight. Furthermore, it is expensive and has low versatility as a clothing fiber. Moreover, even if it is difficult to dye and can be dyed under specific conditions, there is a problem that the light fastness of the dyed product is inferior. In order to compensate for these weak points, fibers other than high-strength synthetic fibers may be combined.

  Fibers other than high-strength synthetic fibers combined with high-strength synthetic fibers are not particularly limited, and examples include natural fibers, regenerated fibers, semi-synthetic fibers, synthetic fibers (excluding high-strength synthetic fibers), and inorganic fibers. Two or more of these may be combined.

In particular, when applied to protective clothing such as fire and fire protective clothing, work clothes for electrical work, work clothes for welding, work gloves, etc., a fiber having a LOI value (Limited Oxygen Index) of 25 or more Are preferably combined. Here, the LOI value is a relative numerical value indicating combustibility and is measured according to JIS K 7201-1995. Specifically, it means the minimum oxygen concentration necessary for the substance to burn continuously for 3 minutes or more, or for the combustion length after flame to continue to burn for 50 mm or more. Therefore, the higher the LOI value, the higher the flame retardancy. Examples of fibers having a LOI value of 25 or more include meta-aramid fibers, polyphenylene sulfide fibers, noporoid fibers, polyclar fibers, modacrylic fibers, flame retardant polyester fibers (all are synthetic fibers), and the like.
In addition, all the LOI values of the above-described high-strength synthetic fibers are 25 or more.

  The ratio of the high-strength synthetic fiber and the fiber other than the high-strength synthetic fiber is not particularly limited, and may be set as appropriate in consideration of the physical properties required for the fiber structure. A ratio is 5 weight% or more with respect to the whole fiber structure. If the proportion of the high strength synthetic fiber is less than 5% by weight, the characteristics cannot be sufficiently exhibited. For example, high-strength synthetic fibers have characteristics such as being hard to cut against sharp metals such as blades and not shrinking when burned, but if the proportion of high-strength synthetic fibers is too small, these characteristics will be fully demonstrated. Not. More preferably, the ratio of the high strength synthetic fiber is 35% by weight or more, and more preferably 50% by weight or more.

  In addition, when fibers having a LOI value of 25 or more are combined as fibers other than high-strength synthetic fibers, the ratio is preferably 95% by weight or less, more preferably 5 to 65% by weight with respect to the entire fiber structure. %, More preferably 10 to 40% by weight. As a fiber other than the high-strength synthetic fiber, when the ratio of the fiber having a LOI value of 25 or more exceeds 95% by weight, the characteristics of the high-strength synthetic fiber are not sufficiently exhibited as described above.

  The water-repellent high-strength synthetic fiber structure of the present invention is treated with a first treatment liquid mainly composed of a reaction product of an organohydrogenpolysiloxane and a metal alkoxide, followed by a second treatment mainly comprising a fluorine-containing compound. It can be obtained by treating with a liquid. Here, the main component means that it accounts for 50% by weight or more of the components excluding the liquid medium constituting the treatment liquid.

  The reaction product of the organohydrogenpolysiloxane and the metal alkoxide, which is the main component of the first treatment liquid, is an organohydrogenpolysiloxane, a metal alkoxide, or a condensation catalyst for promoting the reaction of the organohydrogenpolysiloxane and the metal alkoxide. , And if necessary, a mixed composition consisting of water can be obtained by stirring under specific conditions. In this reaction, the alkoxide group of the metal alkoxide is hydrolyzed by moisture in the air or water in the mixed composition, and then the hydroxyl group of the metal hydroxide generated by the hydrolysis becomes the hydrogen of the organohydrogenpolysiloxane. This is a reaction in which dehydrogenative condensation with atoms and finally crosslinking of the organohydrogenpolysiloxanes form a network cross-linked structure.

  By covering high-strength synthetic fibers with a coating containing the above reaction product as a main component, it is possible to increase the lubricity of the fiber surface and lower the frictional resistance, thereby suppressing fibrillation due to physical impact such as washing. It becomes possible. Moreover, since the adhesiveness between the reaction product and the fluorine-containing compound coating is good, it is possible to suppress the peeling of the coating due to washing or the like.

  The organohydrogenpolysiloxane used in the present invention only needs to have two or more hydrogen atoms directly bonded to silicon atoms in the molecular chain terminal and / or molecular chain of the polysiloxane, and the molecular structure is linear. There is no particular limitation such as a branched shape or a ring shape. When the number of hydrogen atoms directly bonded to the silicon atom is less than 2, the condensation reaction with the metal alkoxide and the crosslinking between the organohydrogenpolysiloxanes are not efficient, and the intended reaction product (described later) is obtained. It becomes difficult.

  In the present invention, a commercially available organohydrogenpolysiloxane can be used without particular limitation, but preferably has a degree of polymerization of 3 to 100, more preferably 3 to 80. When the degree of polymerization is less than 3, crosslinking between the organohydrogenpolysiloxanes is not efficient, and it becomes difficult to obtain a target reaction product. When the degree of polymerization exceeds 100, the viscosity is high and difficult to handle. In addition, the molecular weight of the organohydrogenpolysiloxane having a polymerization degree of 3 to 100 is usually 200 to 6000.

  When producing an organohydrogenpolysiloxane, it is impossible to accurately control the degree of polymerization. Accordingly, when an organohydrogenpolysiloxane having a degree of polymerization of 3 to 100, more preferably 3 to 80 is used in the present invention, the degree of polymerization is mainly 3 to 100, more preferably 3 to 80 in view of the polymerization degree distribution. There is nothing but the meaning of using organohydrogenpolysiloxane, and other materials may be included.

The organohydrogenpolysiloxane may be a copolymer such as dimethylsiloxane / methylhydrogensiloxane copolymer or methylphenylsiloxane / methylhydrogensiloxane copolymer.
Two or more types can be used in combination.
In the present invention, methyl hydrogen polysiloxane is particularly preferably used.

  The metal alkoxide used in the present invention has an alkoxide group on an appropriate metal such as silicon, titanium, zirconium, aluminum, tin, germanium, boron, iron, copper, gallium, magnesium, phosphorus, antimony, tantalum, vanadium, and tungsten. A compound in which two or more are bonded, and among them, a silane alkoxide (alkoxysilane) excellent in chemical stability is preferable. When the number of alkoxide groups is one, the organohydrogenpolysiloxanes cannot be bridged with each other, and the desired reaction product cannot be obtained.

  The alkoxide group preferably has 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms. When the number of carbon atoms exceeds 8, the hydrophobicity is strong and the hydrolysis reaction hardly occurs.

In addition, vinyl group, phenyl group, methacryloxy group, acryloxy group, ureido group, chloro group, mercapto group, sulfide group, isocyanate group, glycidoxy group, amino group, epoxy group, etc., as long as it does not affect the hydrolysis / condensation reaction It is also possible to use a compound in which one or more other than the alkoxide group is bonded to a metal atom, such as an alkyl group such as a methyl group, an ethyl group, a propyl group or a butyl group, or an alkyl group having a functional group. These are also included in the metal alkoxide referred to in the present invention. Among them, the metal alkoxide having an amino group is preferably used in the present invention because it has catalytic ability and does not require the addition of a condensation catalyst. More specifically, an aminomethyl group, β-aminoethyl group, γ-aminopropyl group, σ-aminobutyl group, γ- (methylamino) propyl group, γ- (ethylamino) propyl group, γ- (β -Aminoethylamino) propyl group, and a metal alkoxide having a salt in which a part or all of these amino groups are quaternary ammonium-ized.
These metal alkoxides may be used in combination of two or more.

  The amount of the metal alkoxide used varies depending on the type, but is usually 0.05 to 20 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the organohydrogenpolysiloxane. If the amount used is outside the range of 0.05 to 20 parts by weight, it will be difficult to obtain the intended reaction product. That is, if the amount used is less than 0.05 parts by weight, the hydrolysis / condensation reaction cannot sufficiently proceed, and if it exceeds 20 parts by weight, the reaction proceeds excessively, which is not preferable.

  Metal alkoxide absorbs moisture in the air, hydrolyzes itself, and initiates a condensation reaction with organohydrogenpolysiloxane, so it is not always necessary to add water, but water should be added to control the reaction. Is possible. In this case, if a mixed composition composed of organohydrogenpolysiloxane, metal alkoxide, etc. is exposed to the air, the reaction proceeds excessively due to moisture in the air, making it difficult to obtain the desired reaction product. It becomes. Therefore, when adding water, it is preferable to block the mixed composition from the outside air.

  The timing of adding water is preferably such that the mixing of water or a composition containing water with the organohydrogenpolysiloxane or the composition containing organohydrogenpolysiloxane is the last. Others are not particularly limited, and all raw materials (water, metal alkoxide, and condensation catalyst) except organohydrogenpolysiloxane may be mixed in advance with organohydrogenpolysiloxane, All raw materials except water (organohydrogenpolysiloxane, metal alkoxide, and condensation catalyst) may be mixed in advance, and water may be mixed. Furthermore, organohydrogenpolysiloxane and metal alkoxide are mixed in advance. In addition, a mixture of water and a condensation catalyst may be mixed. The point is to prevent the dehydrogenative condensation reaction from occurring until the last raw material is mixed. By doing so, a uniform reaction product can be obtained.

  The usage-amount of water is 1-100 weight part with respect to 100 weight part of metal alkoxide, Preferably it is 5-40 weight part. When the amount used is less than 1 part by weight, the metal alkoxide is not sufficiently hydrolyzed, and the reaction cannot be sufficiently advanced. If the amount used exceeds 100 parts by weight, the reaction product and water are likely to cause phase separation, making it difficult to obtain the desired reaction product.

  Since water is insoluble in organohydrogenpolysiloxane, which accounts for a large proportion in the mixed composition, water is usually added in the form of a mixed solution with a polar organic solvent. Examples of polar organic solvents used for such purposes include alcohols such as methanol, ethanol, propanol, isopropanol and propylene glycol, ketones such as acetone, cyclohexanone and isophorone, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone and sulfolane. And so on. Among these, alcohols have a hydroxyl group in the molecule and are excellent in the effect of uniformly mixing water with the organohydrogenpolysiloxane. Therefore, alcohols are preferably used in the present invention, and lower alcohols are particularly preferably used.

  It is mixed with a polar organic solvent so that the water concentration is 40% by weight or less, preferably 20% by weight or less. When the concentration of water exceeds 40% by weight, the compatibility with the organohydrogenpolysiloxane is poor and the reaction cannot be performed uniformly.

The dehydrogenative condensation reaction between the hydroxyl group produced by hydrolysis of the metal alkoxide and the hydrogen atom of the organohydrogenpolysiloxane is an extremely slow reaction, so industrially, a condensation catalyst is added to accelerate the reaction. Should. Condensation catalysts used for this type of reaction are known, and conventionally known appropriate base catalysts such as ethanolamine, diethanolamine, and triethanolamine can be used. Two or more of these may be combined.
When a condensation catalyst insoluble in the organohydrogenpolysiloxane is used, it is added in a form dissolved in a polar organic solvent.

Although the usage-amount of a condensation catalyst changes also with the kinds, it is 0.01-10 weight part normally with respect to 100 weight part of organohydrogenpolysiloxane, Preferably it is 0.05-5 weight part. If the amount used is less than 0.01 parts by weight, the effect as a condensation catalyst is insufficient, and if it exceeds 10 parts by weight, the reaction proceeds rapidly and cannot be controlled.
In addition, when a metal alkoxide has an amino group, since an amino group exhibits catalytic ability, it is not necessary to add a condensation catalyst separately.

  By stirring the mixed composition in which water is added to the organohydrogenpolysiloxane, metal alkoxide, and condensation catalyst described above as necessary, at 0 to 100 ° C. for a certain period of time, the main component of the first treatment liquid is obtained. A reaction product of an organohydrogenpolysiloxane and a metal alkoxide can be obtained. If the temperature is less than 0 ° C., the reaction proceeds slowly and is not efficient, and if the temperature exceeds 100 ° C., water evaporates, making it difficult to obtain the desired reaction product. A more preferable temperature range is 10 to 30 ° C.

  The time required to obtain the target reaction product varies depending on the temperature, humidity, the presence or absence of addition of water, etc., and is not particularly limited.

  Here, the target reactive organism refers to a state in which organohydrogenpolysiloxanes are crosslinked in a network by metal alkoxides to increase the molecular weight. The molecular weight of the reaction product varies depending on the degree of polymerization of the organohydrogenpolysiloxane used, but is usually 500 to 100,000. When the molecular weight is less than 500, a film having sufficient strength cannot be formed, and the film easily peels off by washing or the like. When the molecular weight exceeds 100,000, the reaction product gels and becomes difficult to handle, and the coating is fragile and easily peels off. In addition, the viscosity of the mixed composition when the molecular weight is 500 to 100,000 is usually 30 to 100,000 cP, and this can be used as a measure of the molecular weight.

  The reaction between the organohydrogenpolysiloxane and the metal alkoxide needs to be stopped when the mixed composition thickens to the above range. The reaction is stopped by diluting the mixed composition with a nonpolar organic solvent. As a result, the reaction rate is significantly reduced, and the reaction is apparently stopped. In addition, the dilution liquid obtained in this way is the 1st process liquid in this invention. Examples of the nonpolar organic solvent include n-hexane, n-heptane, cyclohexane, isoparaffin, benzene, toluene, xylene and the like. In addition, mineral oil fractions such as industrial gasoline, petroleum naphtha, and taven can also be used. Furthermore, two or more of these may be combined. Of these, inexpensive petroleum naphtha and tarben are preferably used.

The dilution with the nonpolar organic solvent is prepared so that the concentration of the reaction product is 1 to 50% by weight. When the concentration of the reaction product is less than 1% by weight, it becomes difficult to impart a target amount of the reaction product to the high-strength synthetic fiber structure. If the concentration of the reaction product exceeds 50% by weight, the reaction between the organohydrogenpolysiloxane and the metal alkoxide cannot be stopped, and the reaction proceeds even after dilution.
In addition, the metal alkoxide present in an unreacted state is hydrolyzed with moisture in the air after being applied to the high-strength synthetic fiber structure, and is further added by the reaction product or the second treatment liquid. The reaction is completely stopped by dehydrogenative condensation.

  The amount of reaction product applied to the high-strength synthetic fiber structure is preferably 0.01 to 50% by weight, more preferably 0.1 to 40% by weight. When the applied amount is less than 0.01% by weight, fibrillation cannot be suppressed, and sufficient durable water repellency cannot be obtained. Even if the applied amount exceeds 50% by weight, there is no difference in the ability to suppress fibrillation and durable water repellency, but the texture is remarkably cured, and when used for protective clothing, for example, it becomes unusable. In addition, in this specification, when it is called the application amount of a reaction product, it shall mean the total application amount containing not only the target reaction product but unreacted organohydrogenpolysiloxane and a metal alkoxide.

  By adjusting the concentration of the reaction product in the first treatment liquid and the amount of the first treatment liquid applied to the high-strength synthetic fiber structure, a target amount of the reaction product can be imparted to the high-strength synthetic fiber structure. it can.

  As a method for applying the first treatment liquid to the high-strength synthetic fiber structure, a conventionally known method can be adopted, and examples thereof include a mangle-pad method, a spray method, and a coating method. Among these, the mangle-pad method can be preferably used in the present invention because each fiber can be reliably coated while maintaining the voids between the fibers in the high-strength synthetic fiber structure.

  Next, the high-strength synthetic fiber structure provided with the first treatment liquid is dried. The drying is not particularly limited as long as the non-polar organic solvent and water do not remain. What is necessary is just to set suitably in consideration of the kind (boiling point) and production efficiency of a nonpolar organic solvent.

  In the processing method of the present invention, after the high-strength synthetic fiber structure is treated with the first treatment liquid mainly composed of the reaction product of organohydrogenpolysiloxane and metal alkoxide, the high-strength synthetic fiber structure is further treated with a fluorine-containing compound as the main component. Treat with 2 treatment solutions.

  As the fluorine-containing compound in the present invention, a conventionally known compound having water repellency can be used. Specifically, a monomer having a fluoroalkyl group, such as an acrylate, methacrylate, maleate having a fluoroalkyl group, Examples thereof include a polymer having a structural unit derived from fumarate or urethane having a fluoroalkyl group.

  When a commercially available fluorine-based water repellent is used, either an organic solvent type or a water dispersion type can be used, but an organic solvent type is preferred. If the water-dispersed type is used, the reaction of the reaction product imparted by the first treatment liquid may proceed excessively, and sufficient durable water repellency may not be obtained. The organic solvent type fluorine-based water repellent is commercially available in a form in which the above-mentioned fluorine-containing compound is dissolved or dispersed in an appropriate concentration with a nonpolar organic solvent.

  The amount of the fluorine-containing compound applied to the high-strength synthetic fiber structure is preferably 0.1 to 10% by weight, more preferably 0.2 to 5% by weight. If the applied amount is less than 0.1% by weight, sufficient durable water repellency cannot be obtained. There is no difference in durable water repellency even if the applied amount exceeds 10% by weight.

  By adjusting the concentration of the fluorine-containing compound in the second treatment liquid and the amount of the second treatment liquid applied to the high-strength synthetic fiber structure, a target amount of the fluorine-containing compound can be imparted to the high-strength synthetic fiber structure. it can.

The second treatment liquid contains a fluorine-containing compound as an essential component, but it is also possible to use a crosslinking agent in combination. By using a cross-linking agent in combination, acrylic, urethane, etc. that form the basis of the fluorine-containing compound are cross-linked, and the adhesion between the reaction product film of the organohydrogenpolysiloxane and the metal alkoxide is improved. Durability can be improved. Examples of the crosslinking agent used for such purposes include compounds having a reactive group such as melamine resin, epoxy resin, and isocyanate compound.
Two or more kinds of crosslinking agents can be used in combination.

The usage-amount of a crosslinking agent is 0.1-20 weight% with respect to a fluorine-containing compound, Preferably it is 1-10 weight%. When the amount of the crosslinking agent used is less than 0.1% by weight, the above-mentioned effect due to the combined use of the crosslinking agent is not sufficiently exhibited, and when it exceeds 20% by weight, sufficient initial water repellency cannot be obtained. The texture is markedly cured.
The crosslinking agent is added in the form of an organic solvent solution or an aqueous dispersion according to the form of the second treatment liquid.

  As described above, a nonpolar organic solvent is preferably used as the solvent for the fluorine-containing compound and, if necessary, the crosslinking agent. Specific examples include n-hexane, n-heptane, cyclohexane, isoparaffin, benzene, toluene, xylene and the like. In addition, mineral oil fractions such as industrial gasoline, petroleum naphtha, and terpenes can be used. Furthermore, two or more of these may be combined. Of these, inexpensive petroleum naphtha and terpenes are preferably used.

  In the second treatment liquid, the concentration of the fluorine-containing compound is preferably 0.1 to 20% by weight, more preferably 0.5 to 2% by weight. When the concentration of the fluorine-containing compound is outside the range of 1 to 20% by weight, it becomes difficult to impart a target amount of the fluorine-containing compound to the high-strength synthetic fiber structure.

  As a method for applying the second treatment liquid to the high-strength synthetic fiber structure, as in the case of the first treatment liquid, conventionally known methods such as a mangle-pad method, a spray method, and a coating method can be employed. However, the mangle-pad method is preferably used.

  Next, the high-strength synthetic fiber structure to which the second treatment liquid is applied is dried. The drying is not particularly limited as long as the non-polar organic solvent and water do not remain. What is necessary is just to set suitably in consideration of the kind (boiling point) and production efficiency of a nonpolar organic solvent.

Finally, heat treatment is performed at 50 to 200 ° C. in order to form a film of the fluorine-containing compound. When the heat treatment temperature is less than 50 ° C., a film having sufficient strength cannot be formed, and the film easily peels off due to physical impact such as washing. Even if the heat treatment temperature exceeds 200 ° C., there is no difference in durable water repellency, which is not efficient. When using a crosslinking agent together, it is necessary to heat-treat at a temperature higher than the temperature at which the crosslinking agent reacts. Moreover, the heat processing time at this time is 30 seconds-10 minutes normally.
It is also possible to perform drying and heat treatment in one step.

  Thus, the high strength synthetic fiber structure can be provided with water repellency having durability against washing, dry cleaning, friction and the like. Moreover, the original physical properties of the high-strength synthetic fiber are not impaired.

[Example]
EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example. Unless otherwise indicated, parts and% in the examples are based on weight. Moreover, the performance of the fabric obtained by water-repellent processing was evaluated by the following method.

(1) Water repellency It measured by the water repellency test (spray test) of JIS L 1092-1998. The water repellency was evaluated for the finished sample and the sample subjected to the washing treatment or the abrasion treatment.
(2) Fibrillation The processed sample and the surface of the sample subjected to the washing treatment were photographed at three places with a scanning electron microscope at a magnification of 500. The states before and after washing were compared, and three levels of evaluation were performed according to the following criteria.
○ Similar to the sample before washing, fibrils are not observed on the fiber surface △ Some fibrils are observed on the fiber surface × Many fibrils are observed on the fiber surface (3) Flameproofing JIS L 1091-1999 A-4 method ( Measured by the vertical method). The flameproofing evaluation was performed on the finished sample.

(4) Washing treatment Washing treatment was performed in accordance with method 103 of JIS L 0217-1995.
That is, 25 liters of hot water at 40 ° C. is put into a two-layer electric washing machine for household use, and a washing solution containing household synthetic detergent (manufactured by Kao Corporation, new enzyme Zab) is added to 1 g / liter. Loaded cloth (cotton gold cloth) was put together with the sample (finished) so that the ratio was 1:30, and the cloth was washed for 50 minutes. After dehydrating for 30 seconds, rinsing was performed for 10 minutes while overflowing normal temperature water. Thereafter, dehydration, rinsing and dehydration were performed under the same conditions, and the washing was performed 10 times. The washing 30 times treatment is a repetition of this operation 3 times. After the laundering treatment, the samples were air-dried overnight and evaluated for water repellency and fibrillation.

(5) Abrasion treatment The sample (finished) is attached to a Schiefer type abrasion tester, a uniform tension is applied to the sample with a tensile load of 2.26 kg, and the same work cloth as the sample is attached to the friction element, and the pressure load The sample was rubbed 100 times or 500 times in multiple directions at 2.27 kg, a frictional member rotational speed of 238 rpm, and a sample rotational speed of 250 rpm. At this time, 70 μl of water was dropped on the sample and rubbed in a wet state. About the obtained sample, the water repellency of the friction surface was evaluated.

A reaction product having a viscosity of 500 cP was obtained by stirring the mixed composition shown in Formula 1 below for 60 minutes under the conditions of 25 ° C. and 65% RH.
Formula 1
Methyl hydrogen polysiloxane (degree of polymerization 60, molecular weight 3600, solid content 100%) 100 parts 3-aminopropyltriethoxysilane (solid content 100%) 2 parts Next, the reaction product was terpene (boiling point 150-200 ° C.). The first treatment liquid was prepared by diluting to a concentration of 10%.
Polyparaphenylene terephthalamide fiber (Kevlar (registered trademark) manufactured by Toray DuPont Co., Ltd., LOI value 29, tensile strength of raw cotton 2.9 GPa), which is a kind of para-aramid fiber, is used as the first treatment liquid. A plain woven fabric (warp density 49 / 2.54 cm, weft) woven using a spun yarn (warp: cotton count 20/2, tensile strength 50.0 N, weft: cotton count 20/1, tensile strength 20.6 N) The density was 47 / 2.54 cm, and the basis weight was 200 g / m ² ).
The Kevlar spun yarn used here is a short fiber (single yarn fineness 2.2 decitex, fiber length 51 mm) obtained by cutting Kevlar fiber (raw cotton tensile strength 2.9 GPa) for spinning by the ring spinning method. Spinned.
Subsequently, it was impregnated in the second treatment liquid shown in the following formulation 2, narrowed down to 45% by mangle, dried at 120 ° C. for 1 minute, and then heat treated at 170 ° C. for 2 minutes to obtain a water-repellent fabric.

Formula 2
Fluoroalkyl group-containing solvent-based water repellent (block isocyanate compound blend, solid content 10%) 10%
Turpen 90%

A reaction product having a viscosity of 500 cP was obtained by stirring the mixed composition shown in the following formulation 3 for 40 minutes under sealing conditions.
Formula 3
Methyl hydrogen polysiloxane (degree of polymerization 60, molecular weight 3600, solid content 100%) 100 parts 3-aminopropyltriethoxysilane (solid content 100%) 2 parts Water 10 / isopropyl alcohol 90 mixed solution 10 parts Hereinafter, Examples In the same manner as in Example 1, a water repellent fabric was obtained.

By stirring the mixed composition shown in the following formulation 4 for 40 minutes under the conditions of 25 ° C. and 65% RH, a reaction product having a viscosity of 500 cP was obtained.
Formula 4
Methyl hydrogen polysiloxane (degree of polymerization 60, molecular weight 3600, solid content 100%) 100 parts tetraethoxysilane (solid content 100%) 2 parts ethanolamine (solid content 100%) 0.5 parts Hereinafter, the same as in Example 1 A water repellent cloth was obtained.

A reaction product having a viscosity of 30 cP was obtained by stirring the mixed composition shown in the following prescription 5 for 60 minutes under the conditions of 25 ° C. and 65% RH.
Formula 5
Methyl hydrogen polysiloxane (degree of polymerization 60, molecular weight 3600, solid content 100%) 100 parts butyl titanate (solid content 100%) 2 parts ethanolamine (solid content 100%) 0.5 parts Hereinafter, in the same manner as in Example 1. To obtain a water repellent cloth.

As a high-strength synthetic fiber structure, polyparaphenylene terephthalamide fiber (Kevlar (registered trademark) manufactured by Toray DuPont Co., Ltd., LOI value 29, tensile strength of raw cotton 2.9 GPa), which is a kind of para-aramid fiber 65% blended yarn composed of 35% polymetaphenylene isophthalamide fiber, which is a kind of meta-aramid fiber (NOMEX (registered trademark) manufactured by DuPont, LOI value 29, tensile strength of raw cotton 0.6 GPa) 2/1 twill woven fabric (cotton count 30/2, tensile strength 19.1 N) (warp density 85 / 2.54 cm, weft density 54 / 2.54 cm, basis weight 230 g / m ² ) A water repellent cloth was obtained in the same manner as in Example 1 except that.

[Comparative Example 1]
A water-repellent fabric was obtained in the same manner as in Example 1 except that the treatment liquid shown in Formula 6 below was used as the first treatment liquid.
Formula 6
Methyl hydrogen polysiloxane (degree of polymerization 60, molecular weight 3600, solid content 100%) 10%
Turpen 90%

[Comparative Example 2]
A water-repellent cloth was obtained in the same manner as in Example 1 except that the treatment liquid shown in Formula 7 below was used as the first treatment liquid. Formulation 7 is a processing liquid in which the mixed composition shown in Formulation 1 is dissolved (diluted) in turpentine without reacting.
Formula 7
Methyl hydrogen polysiloxane (degree of polymerization 60, molecular weight 3600, solid content 100%) 10%
3-aminopropyltriethoxysilane (solid content 100%) 0.2%
Turpen 89.8%

[Comparative Example 3]
By stirring the mixed composition shown in the following formulation 8 for 40 minutes under the conditions of 25 ° C. and 65% RH, a reaction product having a viscosity of 30 cP was obtained.
Formula 8
Dimethylpolysiloxane (degree of polymerization 60, molecular weight 4500, solid content 100%) 100 parts 3-aminopropyltriethoxysilane (solid content 100%) 2 parts Hereinafter, in the same manner as in Example 1, a water-repellent fabric was obtained.

[Comparative Example 4]
The treatment solution shown in Formula 2 is impregnated with the plain woven fabric used in Example 1, drawn to 70% with a mangle, dried at 120 ° C. for 1 minute, and then heat treated at 170 ° C. for 2 minutes to make a water-repellent fabric Got.

  Table 1 shows the results of evaluating water repellency and fibrillation of the above Examples, Comparative Examples, and unprocessed fabrics (the plain fabric used in Example 1).

  As is apparent from the table, it can be seen that the water-repellent fabric obtained by the water-repellent processing method of the present invention is excellent in durable water repellency. Moreover, the original physical properties (flameproof) of the high strength synthetic fiber are maintained.

Claims (4)

With organohydrogenpolysiloxane
A metal alkoxide having an amino group in the molecule or a metal alkoxide having no amino group in the molecule and an amino group-containing compound;
To produce a reaction product having a cross-linked structure and a molecular weight of 500 to 100,000, and then treating the high-strength synthetic fiber structure with the first treatment liquid containing the reaction product as a main component, A water-repellent processing method for a high-strength synthetic fiber structure, characterized by treating with a second treatment liquid containing a compound as a main component. High strength synthetic fiber structures, characterized in that it contains at least one high strength synthetic fiber 5 to 100 wt% selected from the para-aramid fiber, wholly aromatic polyester fibers and heterocyclic fibers, according to claim 1, wherein the method of. The method according to claim 1 or 2, wherein the high-strength synthetic fiber structure contains 0 to 95% by weight of a fiber having a LOI value of 25 or more as a fiber other than the high-strength synthetic fiber . 4. A process according to claim 1, 2 or 3, characterized in that the metal alkoxide is an alkoxysilane.