DE69430873T2 - METHOD FOR TREATING TEXTILE PRODUCTS AND TEXTILE PRODUCTS TREATED WITH IT - Google Patents

Abstract

A fiber is firstly treated with a carboxylic acid-metal complex obtained from a metal salt and a carboxylic acid in a first stage, and then treated with a usual fluorine-containing water- and oil-repellent in a second stage. According to the present invention, the water-repellency which is durable to washing and friction is imparted to a textile, and the touch, the feeling and the flexibility of the textile itself are not deteriorated.

Description

FIELD OF INVENTION

The present invention relates to a method of treating a fabric, and a treated fabric. More particularly, it relates to a method of treating a fabric, the method maintaining durable water and oil repellency even after long-term use including washing and further maintaining a touch, a feeling and a flexibility of the fiber itself by a modification treatment of the fabric.

It has been known heretofore that a fluorine-containing compound having a fluoroalkyl group imparts excellent water and oil repellency to a fabric. In particular, a treating agent of acrylic polymer having a perfluoroalkyl group has been practically used. However, in a treatment using the treating agent of the acrylic polymer having a perfluoroalkyl group, there is a disadvantage that a touch, sensation and flexibility of the treated fabric are significantly deteriorated, and the resulting water repellency is significantly deteriorated by washing or abrasion. As an attempt to improve the durability of water and oil repellency, a combined agent has been used in the treatment together with the acrylic polymer having the fluoroalkyl group. Examples of the combined agent include a melamine resin or a urea resin. When these resins are used in combination, the durability is improved as compared with the case that the polymer is used alone. but the touch, sensation and flexibility of the fiber itself are liable to be deteriorated. Consequently, it can be said that the durability and the touch, sensation and flexibility of the fiber itself are contradictory to each other when the fluorine-containing polymer is used. Japanese Patent Publication Kokai No. 98568/1993 describes that animal hair fibers are treated with an alkyl phosphate salt to impart water repellency and flexibility to the animal hair fibers. However, the treated fibers are inferior in durability because they are not treated with a fluorine-containing water and oil repellent agent.

EP-A-0 624 680 discloses an agent for treating a tissue comprising a modifier which is a fluorine-containing phosphoric acid derivative having the formula (I) as defined below wherein R¹ and R² are the same or different, a hydrogen atom or Rf-(CH₂)m-, where Rf is a saturated or unsaturated, straight or branched fluorine-containing aliphatic group having 4 to 20 carbon atoms in which an oxygen atom, a nitrogen atom, a sulfonyl group and/or an aromatic ring may be present between the carbon atoms; and m is 1 or 2; A is an oxygen atom, a sulfur atom or a direct bond, and n is 1 or 2. The treating agent further comprises a metal salt compound. After treating the fabric with the treatment agent, the fabric is treated with a fluorine-containing water and oil repellent agent or a fluorine-containing stain protection agent.

Heretofore, a chromium complex of carboxylic acid has also been used as a processing agent for a fabric or paper for the purpose of imparting water repellency. In particular, a chromium complex of carboxylic acid having a perfluoroalkyl group has been used for the purpose of imparting oil repellency in addition to for water repellency (see Japanese Patent Publications Kokoku Nos. 466/1958 and 3274/1969). However, the effect of these chromium complexes is not always sufficient and further improvement of the effect has been demanded.

An object of the present invention is to maintain durable water and oil repellency even after long-term use including washing and the like, and to maintain a touch, sensation and flexibility of the fiber itself even after treatment. The present invention provides a method of treating a fabric comprising:

(A) Applying a modifier consisting of a phosphoric acid derivative represented by the general formula:

wherein R¹ and R² are the same or different and are a hydrogen atom or a saturated or unsaturated, straight-chain or branched hydrocarbon group having 4 to 20 carbon atoms, in which an oxygen atom, a nitrogen atom, a sulfonyl group or an aromatic ring may be present between the carbon atoms, provided that R¹ and R² are not simultaneously a hydrogen atom;

A is an oxygen atom, a sulfur atom or a direct bond is; and

n is 1 or 2,

or a salt thereof, to a tissue before or after treating the tissue with a fixative consisting of a metal salt compound,

and treating the tissue with an acid solution with a pH of 1 to 5, and then

(B) Treating the textile with a fluorine-containing water and oil repellent agent.

The present invention also provides a fabric treated with the above method of treatment.

In the present invention, the term "treatment" as used herein means that a fabric is brought into contact with a treatment liquid containing the modifier, the fixative, the metal complex or the fluorine-containing water- and oil-repellent agent. The treatment can be carried out by, for example, an immersion, an impregnation, a padding process or a coating process.

In the first stage of treatment, the tissue can be treated with the modifier after treatment with the fixative. Alternatively, a tissue can be treated with the fixative after treatment with the modifier.

The modifier used in the first stage of the treatment is the phosphoric acid derivative or the salt thereof represented by the above general formula (I). The phosphoric acid derivative is a compound having a P-OH bond and a hydrocarbon group. The Hydrocarbon group usually means a saturated or unsaturated, straight-chain or branched aliphatic hydrocarbon group, and includes those in which an oxygen atom, a nitrogen atom, a sulfonyl group or an aromatic ring is present in a carbon-carbon bond. It is preferable that the hydrocarbon group is an alkyl group. Examples of the salt of the phosphoric acid derivative include a monovalent metal salt such as a sodium salt, a potassium salt or a lithium salt; an organic amine salt such as a diethanolamine salt, a triethylamine salt, a propylamine salt or a morpholine salt; and an ammonium salt. A molecular weight of the phosphoric acid derivative or the salt thereof varies depending on the general formula, but is preferably not more than 2,000.

Specific examples of the phosphoric acid derivative are as follows.

The metal in the metal salt compound as the fixing agent used in the first stage of the treatment may be a multivalent (divalent or more) metal that ionically bonds to a hydroxyl group bonding with a phosphorus atom. Usually, chromium, zirconium, titanium or aluminum is preferred. It is preferred that the metal salt compound is a water-soluble one. For example, chloride, nitrate, sulfate or hydroxide is preferred. Among these, basic chromium sulfate and basic zirconium sulfate are particularly preferred in view of durability.

In the present invention, the fluorine-containing water- and oil-repellent agent used in the second step of the treatment is a fluorine-containing compound having a perfluoroalkyl group. The fluorine-containing compound may be a known fluorine-containing polymer having a side chain of a perfluoroalkyl group. For example, the following monomers forming polymers or copolymers may be used.

wherein R₁ is a hydrogen atom or a methyl group; R₂ is a lower alkyl group; X is a divalent organic group; m is an integer of 1 to 4; and n is an integer of 5 to 21.

An average molecular weight of the fluorine-containing polymer is usually from 5,000 to 500,000.

The fluorine-containing compound may be a fluorine-containing urethane compound or a fluorine-containing ester compound, and examples thereof include the following.

where Rf is CmFm+1 (m is an integer from 5 to 21); and n is 0 to 4.

The fluorine-containing water- and oil-repellent agent can be used in combination with various combined agents, and examples of the combined agents include a melamine resin, a urea resin, a hindered isocyanate or glyoxal.

In the first stage of the treatment of the present invention, the tissue is treated with the modifier and the fixing agent. The order of using the modifier and the fixing agent can be freely selected as described hereinafter. Examples of the method for treatment using the modifier and the fixing agent include the following methods (1), (2) and (3).

(1) A method comprising first treating with the fixative and then treating with the modifier will be explained. The fabric is immersed in the fixative solution and removed from a bath, and then water is wiped from the fabric. After the fabric is immersed in a modifier solution, an acid solution is added to the same bath to adjust the pH to 1 to 5, preferably from 3 to 4, followed by standing. The fabric is wiped to remove water, sufficiently washed with water, wiped to remove water, and then dried. Alternatively, the fabric is immersed in the modifier solution, and after wiping off the water, the fabric is immersed in an acid solution (pH: 1 to 5), wiped to remove water, sufficiently washed with water, wiped to remove water, and then dried.

(2) The order of immersion in the fixative solution and immersion in the modifier solution can be reversed. First, the fabric is immersed in the modifier solution, taken out of the bath, and then wiped to remove water. After the fabric is immersed in the fixative solution, an acid solution is added to the same bath to adjust the pH to 1 to 5, preferably from 3 to 4, followed by standing. The fabric is wiped to remove water, sufficiently rinsed with water washed, wiped to remove water, and dried therein. Alternatively, the fabric is immersed in the fixative solution, and after wiping off water, the textile is immersed in the acid solution, wiped to remove water, sufficiently washed with water, wiped to remove water, and then dried.

(3) It is also possible to carry out a series of these treatments in the same bath. For example, after the fabric is immersed in the fixing solution, the modifier is added into the bath, and the fabric is immersed in the bath. An acid solution is added to adjust the pH to 1 to 5, preferably 3 to 4, followed by standing. The fabric is wiped to remove water, sufficiently washed with water, wiped to remove water, and then dried. The fixing solution may be added after the fabric is immersed in the modifier solution.

In the above methods (1), (2) and (3), the solution of the metal salt compound as the fixing agent is an aqueous solution of 0.01 to 10% by weight, preferably 0.03 to 3% by weight. A temperature of the fixing agent solution is usually from 20 to 70°C. A solution of the phosphoric acid derivative as the modifier is an aqueous solution or a lower alcohol solution of 0.01 to 10% by weight, preferably 0.03 to 3% by weight. Examples of the lower alcohol include methanol, ethanol or isopropyl alcohol. A temperature of the modifier solution is usually from 5 to 90°C, preferably from 20 to 70°C.

The acid solution used for immersion or pH adjustment is a solution, preferably an aqueous solution, containing a mineral acid such as hydrochloric acid and sulfuric acid, or an organic acid such as formic acid, Acetic acid and propionic acid. A concentration of the acid solution is not particularly limited, but it is usually from 0.05 to 30 wt%, preferably from 0.1 to 10 wt%. A temperature of the acid solution is usually from 5 to 90°C, preferably from 20 to 70°C. An immersion time in each of the fixing agent solution, the modifier solution and the acid solution is usually at least 10 seconds, preferably from 1 to 120 minutes, more preferably from 1 to 30 minutes. A residence time in the bath adjusted to the pH of 1 to 5 is usually at least 10 seconds, preferably from 1 to 120 minutes. A drying temperature is usually from 10 to 70°C, preferably room temperature. The drying time varies depending on the drying condition (particularly the drying temperature), but it is usually within 24 hours, preferably from 0.1 to 10 hours. In the case of the same bath shown in the above method (3), a weight ratio of the fixing agent to the modifier in the bath is usually from 0.1:1 to 10:1.

The method of the second stage (B) may be a method that has been used heretofore. For example, the treatment is carried out by an immersion, a padding method, a coating method or the like, followed by drying. In this case, the combined agent such as the melamine resin and the urea resin may be used in combination. If necessary, heat treatment, calendering, and the like may be carried out. It is also possible to use a treating agent other than the fluorine-containing compound, such as a silicone compound, in combination.

The form of the fluorine-containing water and oil repellent agent may be an emulsion or a solution in an organic solvent. In the case of the emulsion, it is preferable to use a water-soluble lower alcohol or a ketone (isopropyl alcohol is particularly preferred) in an amount of 0.1 to 10 wt.%, preferably from 1 to 5 wt.%, based on the emulsion, to the emulsion in view of the penetration of the fluorine-containing water- and oil-repellent agent.

The second stage of treatment may be applied to any fabric. For example, a resulting carpet (or fabric) may be subjected to the second stage of treatment. Alternatively, the second stage of treatment may be applied to raw yarns or raw hair used for the carpet, and the carpet may be made using the treated raw yarns or raw hair. The raw yarns and raw hair may be subjected to the first stage of treatment, and then the resulting carpet may be subjected to the second stage of treatment.

According to the invention, there is no disadvantage that the water and oil repellency is obtained only on the surface of the textile fabric, since the phosphoric acid derivative penetrates into the inside of a fiber bundle and is then fixed. It is possible to impart the advantageous effect to the inside of the fabric even if the fabric has a large thickness. Since the second stage of treatment is further carried out using the fluorine-containing water and oil repellent agent, the durability becomes stronger. When the phosphoric acid derivative is used, the deterioration of the feeling and flexibility of the fabric, which could not be avoided heretofore when using the fluorine-containing water and oil repellent agent alone, is surprisingly improved. Even when the fluorine-containing water and oil repellent agent is used in combination with the combined agent such as a melamine resin and a hindered isocyanate, an unexpected effect of maintaining the same feeling as that of the untreated fabric can be obtained. These effects are not affected by different shapes of the fabric, and the same effect can be obtained in a fiber, a yarn, a woven fabric, a knitted fabric, a non-woven fabric, an artificial leather made of superfine fibers and the like.

According to the present invention, the fabric to be treated includes a yarn, a woven fabric, a knitted fabric, a nonwoven fabric, an artificial leather and the like formed from the fiber, in addition to the fabric having the shape of the fiber as such. As the fiber, chemical fibers including synthetic fibers such as polyester and nylon can be used in addition to natural fibers such as cotton, wool and silk. It is also possible to use a textile blend of natural fibers and synthetic fibers. The woven fabric and artificial leather comprising superfine fibers which have been remarkably developed recently are suitable for the present invention in view of the fact that the sensation and the touch are considered important. The superfine fibers usually have a fineness of not more than 1.1 dtex (1 denier), preferably not more than 0.89 dtex (0.8 denier), more preferably from 0.89 to 0.00011 dtex (0.8 to 0.0001 denier), most preferably from 0.11 to 0.0011 dtex (0.1 to 0.001 denier).

The fabric obtained by the present invention has the above excellent advantages and is therefore suitably used for applications in which water and oil repellency and stain-proofing properties are required. The fabric suitable for the present invention may be, for example, a carpet. The material of the carpet may be a polyamide such as nylon, a polyester, an acrylic, a cloud and the like and is not particularly limited. The present invention is particularly effective for a nylon carpet which is usually used under severe conditions. The structure, weave and pile length of the carpet are not specifically limited.

The fabric obtained according to the present invention can be used for outdoor applications exposed to rainwater. Examples thereof include a tent, a car cover, a motorcycle cover, a canopy for the rear deck of a truck, a coated sheet for construction, an umbrella and clothing (particularly rainwear such as a raincoat and a poncho).

Applications such as the fabric that is not easily cleaned, the fabric that is easily stained, and the fabric that cannot be washed many times are preferable. For example, the present invention can be used for the fabrics used for a cover of a cap, a footwear (e.g., shoes and slippers), a bag, a pouch or a seat (e.g., a car seat, a seat, a sofa and a chair), interior articles such as a curtain, a carpet, a wall and ceiling of buildings and conveyances (e.g., a car, a train, an airplane and a ship), and various displays.

The present invention is illustrated by the following examples and comparative examples.

The water repellency shown in the examples and comparative examples is measured according to JIS-L-1092-1977 and expressed by the numbers shown in Table 1. The oil repellency is measured by a method according to AATTC TM-118-1975, and a maximum number of oil for which no penetration is observed after 30 minutes from dropping various drops of oil having various surface tensions shown in Table 2 is expressed as the oil repellency.

TABLE 1

Water repellency condition

100 Not wet on the surface

90 Slightly wet on the surface

80 Partly wet on the surface

70 Wet on the surface

50 Wet over the entire surface

0 Completely wet on the front and

Back surfaces TABLE 2

The washing resistance was measured according to JIS-L-0217-103 and was expressed by the water repellency and oil repellency before and after 20 washings. The superscript "+" in the water repellency and oil repellency represents that the result is slightly better than the water repellency and oil repellency.

The water absorption properties are measured according to JIS-K-6550-1976. That is, each sample is immersed in a distilled water, and the water absorption properties are represented by an increase in weight (%) before and after immersion.

Water resistance is measured according to JIS-K-6550-1976. That is, a sample is connected to a water resistance test machine (manufactured by Yasuda Seiki Seisakusho Co., Ltd.) with a structure such that a constant pressure is applied to a hole with a diameter of 50 mm and then a water column is gradually increased. The water resistance is represented by a height of the water column at which water leaks onto the surface of the sample.

The sensation (sensation score) of the treated fiber was evaluated according to the criteria shown in Table 3.

TABLE 3 Sign Sensation

O soft

Δ slightly hard

X hard

EXAMPLE 1 FIRST STAGE OF TREATMENT

A fabric made of superfine fibers (artificial leather SOFRINATIAL (trade name) manufactured by Kuraray Co., Ltd.) was immersed in an aqueous 0.5% solution (bath ratio: 10 : 1) of basic chromium sulfate (BAYCHROME F (trade name) manufactured by Bayer AG) at 30ºC and then subjected to a rotating treatment using a dyeing test machine (manufactured by Tsuzii Senki Kogyo Co., Ltd.) for 30 minutes. After wiping off water the fabric was immersed in a 0.5% aqueous solution (bathing ratio: 10:1) of a compound 1 (phosphoric acid derivative) shown in Table 4 at 50°C and then subjected to a rotating treatment for 30 minutes. After the pH was adjusted to 3 by adding 0.3% aqueous formic acid solution to the bath, the fabric was rotated for 30 minutes, wiped to remove water, washed with water at 40°C and then dried at room temperature.

SECOND STAGE OF TREATMENT

A fluorine-containing water and oil repellent agent (TEX3UARD TG-520 (trade name) manufactured by Daikin Industries, Ltd.) was diluted with tap water so that a solid content was 1%. Further, 2% of a hindered isocyanate (ELASTRON BN-69, manufactured by Daichi Kogyo Seiyaku Co., Ltd.) as a combined agent, 0.2% of a catalyst (ELASTORON CATALYST, manufactured by Daichi Kogyo Seiyaku Co., Ltd.) and 3% of isopropyl alcohol were added to prepare a treatment liquid. The test fabric, which had already been subjected to the first stage of treatment, was immersed in the resulting treatment liquid, pressed with a mangle to adjust a moisture absorption to 50%, dried at 110ºC for 3 minutes and then heat-treated at 160ºC for 1 minute.

The feeling, water repellency, oil repellency, water absorption property and water resistance before and after washing were measured. The results are shown in Table 5.

COMPARISON EXAMPLE 1 ONLY SECOND STAGE OF TREATMENT

The textile sample used in Example 1 was subjected only to the same treatment as the second stage of the treatment used in Example 1. The feeling, water repellency, oil repellency, water absorption property and water resistance before and after washing were measured. The results are shown in Table 5.

COMPARISON EXAMPLE 2 ONLY FIRST STAGE OF TREATMENT

The fabric sample used in Example 1 was subjected only to the same treatment as the first stage of the treatment used in Example 1. The feeling, water repellency, oil repellency, water absorption property and water resistance before and after washing were measured. The results are shown in Table 5.

TABLE 4 Connection 1:

Sodium salt of TABLE 5

(Note) LO and L20 mean "before washing" and "after 20 washes"

According to the present invention, the durable water repellency can be maintained even after long-term use including washing and rubbing, and further, the touch, sensation and flexibility of the fiber itself can be maintained even after treatment of a fabric when it is treated with a phosphoric acid derivative and a fixing agent. The present invention solves the problem of durability and the problem of flexibility which were contradictory to each other while these problems occur when a conventional fluorine-containing water and oil repellent agent is used.

Claims (4)

1. A method for treating a tissue, comprising: (A) Applying a modifier consisting of a phosphoric acid derivative represented by the general formula: wherein R¹ and R² are the same or different and are a hydrogen atom or a saturated or unsaturated, straight-chain or branched hydrocarbon group having 4 to 20 carbon atoms (an oxygen atom, a nitrogen atom, a sulfonyl group or an aromatic ring may be present between the carbon atoms), provided that R¹ and R² are not simultaneously a hydrogen atom; A is an oxygen atom, a sulfur atom or a direct bond; and n is 1 or 2, or a salt thereof, to a tissue before or after treating the tissue with a fixative comprising a metal salt compound, and treating the tissue with an acid solution having a pH of 1 to 5, and then (B) Applying a fluorine-containing water- and oil-repellent agent, which is a fluorine-containing compound having a perfluoroalkyl group, to the fabric. 2. A method for treating a fabric according to claim 1, in which the metal salt compound is a salt of chromium, zirconium, titanium or aluminum. 3. A fabric obtainable by the process according to claim 1 and comprising the fixed fabric modifier and the water and oil repellent agent as applied according to the process of claim 1. 4. A fabric according to claim 3, comprising a superfine fiber having a fineness of at most 0.89 dtex (0.8 denier).