Aqueous water and oil repellent composition

Abstract

An aqueous water and oil repellent composition is produced by emulsifying a an acrylate or methacrylate copolymer containing perfluoroalkyl or perfluoroalkenyl group in the presence of a quaternary ammonium compound in an aqueous medium containing an organic cosolvent which gives a stable dispersion and imparts excellent water and oil repellent properties to the textile and carpets.

Description

FIELD OF INVENTION

The present invention relates to a composition for treatment of textile and carpets for imparting excellent water repellency, oil repellency and soil releasability. The present invention relates to the use of a water and oil-repellent composition which is safe for exposure to humans and animals and presents little environmental impact while providing a durable water and oil repellency to a material to be treated with in a highly simplified method of application.

BACKGROUND OF THE INVENTION

Hitherto, various treatment methods have been proposed in order to impart water, oil and soil repellency to a textile or to a carpet. For example, a process often referred to as “exhaust process” of treating a textile comprises of lowering the pH of a treatment liquid, applying the treatment liquid to the textile, thermally treating the textile with steam, washing the textile with water, and dehydrating the textile as described in the U.S. Pat. Nos. 5,073,442, 5,520,962, 5,516,337 and 5,851,595 and the International Publication WO 98/50619.

The U.S. Pat. No. 5,073,442 discloses a method of treating a textile, comprising of conducting an “exhaust process” by using a water- and oil-repellent agent comprising a fluorine-containing compound, a formaldehyde condensation product and an acrylic polymer. The U.S. Pat. Nos. 5,520,962 and 5,851,595 disclose a method of treating a carpet, comprising of conducting an “exhaust process” by using a fluorinc-containing compound and a polymeric binder. The U.S. Pat. No. 5,516,337 discloses a method of treating a textile, comprising of conducting an “exhaust process” by using a fluorine-containing water- and oil-repellent agent and a metal compound such as aluminum sulfate. The International Publication WO 98/50619 discloses a method of treating a carpet, comprising of conducting an “exhaust process” by using a fluorine-containing water- and oil-repellent agent and a salt such as a magnesium salt. These methods mainly use the water and oil repellent agents in combination with the stain-blocking agents and can give water repellency and oil repellency when using the “exhaust process.” The U.S. Pat. No. 7,147,669 describes an invention wherein no use of a stain blocking agent is made using an “exhaust process.”

It is obvious from the applications described above that the process of inducing water and oil repellency to fabrics is expensive and tedious. There is therefore a need to develop a simpler, less expensive process. The present invention provides such a method of preparing a treated textile, comprising of steps of simply preparing a treatment liquid comprising a water- and oil-repellent agent and applying the treatment liquid to a textile by soaking the textile in it, wherein the water- and oil-repellent agent comprises at least one fluorine-containing compound selected from the group consisting of a fluorine-containing polymers and a fluorine-containing low molecular weight compound, the water- and oil-repellent agent or the treatment liquid additionally contains a cationic emulsifier and/or its salt.

The present invention also provides a textile prepared by the above-mentioned method, and a water- and oil-repellent agent used in the above-mentioned method. A polymer of polymerizable compound having a perfluoroalkyl or perfluoroalkenyl group and an acrylate or methacrylate group can be used as a water and oil-repellent for a fibrous fabric. In order to obtain the perfluoroalkyl group containing (meth)acrylate copolymer, a polymerization method such as bulk polymerization, solution polymerization dispersion polymerization or an emulsion polymerization is used. Emulsion polymerization is industrially advantageous because the copolymer can be obtained directly in the form of an aqueous emulsion in the presence of a surfactant and co-solvent.

However, the water and oil-repellency of a fibrous fabric treated with usual conventional aqueous dispersions is not satisfactory for various reasons. From economical view points, there is a need to develop a water and oil repellent composition that will be capable of imparting water and oil-repellency when used in small quantities, a water and oil-repellent composition capable of achieving the repellency effects when cured at a low temperature, and a water and oil repellent composition capable of providing a high production yield which is less influenced by processing conditions.

SUMMARY OF THE INVENTION

One of the objective of the present invention is to provide an aqueous water and oil-repellent composition which can impart durable water and oil-repellency to fibrous materials and exhibits excellent storage stability.

The present invention provides aqueous water and oil-repellent composition comprising:

• • (A) A perfluoroalkyl or perfluoroalkenyl group compound containing acrylate or (meth)acrylate copolymer groups
  • (B) A surfactant comprising quaternary ammonium compound
  • (C) An aqueous medium

DETAILED DESCRIPTION OF THE INVENTION

In the first step of the method of the present invention, the treatment liquid comprising the water- and oil-repellent agent is prepared. In the step two of the method of the present invention, the treatment liquid is applied to the textile by known procedures such as by immersion, spraying and coating. Usually, the treatment liquid is diluted with water and is adhered to surfaces of the substrate by the methods described above such as an immersion coating, a spray coating and a foam coating to a fabric (for example, a carpet cloth), a yarn (for example, a carpet yarn) or any other fiber in raw or processed form. If necessary, the treatment liquid is applied together with a suitable cross-linking agent, followed by curing. It is also possible to add mothproofing agents, softeners, antimicrobial agents, flame retardants, antistatic agents, paint fixing agents, crease-proofing agents, etc. to the treatment liquid. The concentration of the active component (that is, the fluorine-containing compound) in the treatment liquid contacted with the substrate may be from 0.05 to 10 parts by weight, based on the treatment liquid.

In the step three of the method of the present invention, the textile is washed with water and dehydrated. In order to remove excess water, the textile is dehydrated by a usual dehydration procedure such as a centrifuging and vacuuming procedure. After the step three, the textile can be further dried.

In the emulsion polymerization, there can be used a method of emulsifying a monomer in water in the presence of a polymerization initiator and an emulsifying agent, replacing by nitrogen, and copolymerizing with stirring at the temperature within the range, for example, from 50 to 80 C for 1 to 10 hours. As the polymerization initiator, for example, water-soluble initiators (e.g., benzoyl peroxide, lauroyl peroxide, t-butyl perbenzoate, 1-hydroxycyclohexyl hydroperoxide, 3-carboxypropionyl peroxide, acetyl peroxide, azobisisobutylamidine dihydrochloride, azobisisobutyronitrile, sodium peroxide, potassium persulfate and ammonium persulfate) and oil-soluble initiators (e.g., azobisisobutyronitrile, benzoyl peroxide, di-tert-butyl peroxide, lauryl peroxide, cumene hydroperoxide, t-butyl peroxypivalate and diisopropyl peroxydicarbonate) can be used. The polymerization initiator is used in the amount within the range from 0.01 to 2 parts by weight based on 100 parts by weight of the monomer.

In order to obtain copolymer dispersion in water, which is highly desirable to enhance stability of application during storage, it is desirable that the monomers are atomized in water by using an emulsifying device capable of applying a strong shattering energy (e.g., a high-pressure homogenizer and an ultrasonic homogenizer) and then polymerized with using the water-soluble polymerization initiator. Examples of the water-soluble organic solvent include acetone, methyl ethyl ketone, ethyl acetate, propylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol, tripropylene glycol and ethanol. The water-soluble organic solvent may be used in the amount within the range from 1 to 50 parts by weight, e.g., from 10 to 40 parts by weight, based on 100 parts by weight of water.

The substrate to be treated in the present invention is preferably a textile, including a carpet. The textile may be animal or vegetable origin natural fibers such as cotton, hemp, wool and silk; synthetic fibers such as polyamide, polyester, polyvinyl alcohol, polyacrylonitrile, polyvinyl chloride and polypropylene; semisynthetic fibers such as rayon and acetate; inorganic fibers such as glass fiber, carbon fiber and asbestos fiber; and a mixture of these fibers. The present invention can be suitably used in carpets made of nylon fibers, polypropylene fibers and/or polyester fibers, because the present invention provides excellent resistance to a detergent solution and brushing (mechanical).

The textile may be in any form such as a fiber and a fabric. When the carpet is treated according to the method of the present invention, the carpet may be manufactured using treated fibers or yarns or the manufactured carpet may be directly treated according to the present invention. The water- and oil-repellent agent diluted with water to the content of 0.02 to 30% by weight, preferably 0.02 to 10% by weight.

DETAILED DESCRIPTION OF THE INVENTION

The critical components of the present invention include:

• • a) perfluoroalkylacrylate
  • b) other copolymerizable compound
  • c) a quaternary ammonium compound
  • d) reaction initiator, e.g., AIBN
  • e) chain transfer agent, e.g., alkyl mercaptan
  • f) water miscible organic solvent
  • g) water

Non-limiting specific examples of the polymerizable compound having the perfluoroalkyl or perfluoroalkenyl group and the acrylate or methacrylate groups are represented below:

• • CF₃(CF₂)₇(CH₂)₁₀OCOCH═CH₂
  • CF₃(CF₂)₇(CH₂)₁₀OCOC(CH₃)═CH₂
  • CF₃(CF₂)₆CH₂OCOCH═CH₂
  • (CF₃)₂CF(CF₂)₁₀(CH₂)₂OCOCH═CH₂
  • (CF₃)₂CF(CF₂)₆(CH₂)OCOC(CH₃)═CH₂
  • (CF₃)₂CF(CF₂)₈(CH₂)₂OCOC(CH₃)═CH₂
  • CF₃CF₂(CF₂)₆(CH₂)₂OCOCH═CH₂
  • CF₃CF₂(CF₂)₈(CH₂)₂OCOCH═CH₂
  • CF₃CF₂(CF₂)₁₀(CH₂)₂OCOCH═CH₂
  • CF₃CF₂(CF₂)₆(CH₂)₂OCOC(CH₃)═CH₂
  • CF₃CF₂(CF₂)₁₀(CH₂)₂OCOC(CH₃)═CH₂
  • CF₃(CH₂)₇SO₂N(CH₃)(CH₂)₂OCOCH═CH₂
  • (CF₃)₂CF(CF₂)₆CH₂CH(OH)CH₂OCOCH═CH₂

The amount of the perfluoroalkyl group containing monomer used may range from 40 to 95% by weight, preferably from 50 to 90% by weight, more preferably from 60 to 85% by weight based on the copolymer.

Examples of another copolymerizable compound include ethylenically unsaturated monomers which are copolymerizable with monomers containing perfluoroalkyl or perfluoroalkenyl groups. Non-limiting examples of such monomers are (a) acrylic acid and methacrylic acid, and methyl, ethyl, propyl, 2-ethylhexyl, hexyl, decyl, lauryl, cetyl, stearyl, isobornyl, β-hydroxyethyl, glycidyl, phenyl, benzyl esters thereof (b) vinyl esters of fatty acid such as acetic acid, propionic acid, caprylic acid, lauric acid and stearic acid (c) styrene compounds (d) vinyl halides (e) vinyl alkyl ketones (f) acryl amides and (g) dienes like isoprene.

Examples of quaternary ammonium compounds used in this invention include dialkyl(C₁₂-C₂₂)dimethyl ammonium chloride, alkyldimethyl benzayl ammonium chloride, octadecyltrimethyl ammonium chloride, dialkyl(tallow)dimethylammonium chloride, dodecyltrimethylammonium chloride, hexadecyltrimethyl ammonium chloride, biphenyltrimethylammonium chloride, alkylimidazoline quaternary salt, octadecyldimethylbenzylammonium chloride, polyoxyethylenedodecylmonomethylammonium chloride and 1-hydroxyethyl-2-alkylimidazoline quaternary salt.

The amount of quaternary compound may be from 0.01 to 10 parts by weight, preferably from 2 to 7 parts by weight, based on 100 parts by weight of the polymer.

The aqueous medium in the present invention is preferably water or a mixture of water and another water-miscible solvent. The water soluble organic solvent having a flash point of at least 70° C. is employed as co-solvent. Examples include propylene glycol, dipropylene glycol and dipropylene glycol mono-methyl ether.

Example of a method for preparing the polymer include bulk polymerization method, solution polymerization method, suspension polymerization method, emulsion polymerization method and the like; the emulsion polymerization method is preferable.

In the emulsion polymerization method, it is preferable to copolymerize the monomers in the presence of quaternary ammonium compound/compounds as surfactant in an aqueous medium having a polymerization initiator and a chain transfer agent.

A water soluble initiator is preferable and particularly a water soluble salt of an azo type compound is more preferable. Preferable polymerization temperature is from 50 to 160° C. to assure formation of a stable emulsion.

The chain transfer agent used in this invention includes mercaptans or alkyl mercaptans.

In the present invention, before starting emulsion polymerization, it is preferable to have a mixture of monomers, quaternary ammonium salt and an aqueous medium subjected to mixing and dispersing. A solid content of water and oil-repellent composition of the present invention is preferably from 10 to 40% w/w, more preferably from 20-30% w/w, keeping in view the emulsion stability and cost or the like.

Examples of the materials to be treated with water and oil-repellent composition of the present invention include textile fabrics such as single fiber, complex fiber, cloth, leather, carpets or like, fur, paper, wood, plastics, glass, metals, bricks, ceramics, cement, while the preferable example includes textile fibers such as cotton, hemp, wool, silk and like, synthetic fibers such as polyamide, polyester, PVA, polyacrylonitrile, PP, PVC or like, semi synthetic fibers such as acetate, rayon or the like, inorganic fibers such as carbon fibers, glass fibers, asbestos fibers or like.

The water and oil-repellent composition of the present invention is diluted to a concentration keeping its use in view. Any coating method can be employed depending on a kind of the material to be treated. For example, when employing a dip-coating method, a material to be treated is dipped in a diluted solution of the water and oil-repellent composition, it is preferable to carry out a curing treatment at high temperature (180° C.-200° C.).

For example, when treating textile fabrics such as nylon, polyester, cotton, etc., a non volatile content concentration is preferably from 0.1 to 3% w/w, more preferably from 0.5 to 2% w/w in order to achieve excellent water and oil repellency while maintaining satisfactory hand feel softness of the textile and keeping the economical advantages in view. It is preferable to carry out a heat treatment and curing at 180 to 200° C. for 100 to 300 seconds.

The water and oil-repellent composition of the present invention imparts water and oil repellency excellent in terms of durability without affecting the physical appearance of the textile. The processing method is convenient and provides economical affordability.

Preferred Embodiments of the Present Invention

The following examples which do not limit the present invention, further illustrate the present invention in detail.

The properties are measured as follows:

Water Repellency

Aqueous solution of isopropyl alcohol (IPA) shown in Table 1 is positioned on a test fabric, the water repellency is evaluated according to AATCC-TIM 118-1992 and then expressed as water repellency grade shown in Table 1.

TABLE 1
Water Repellency Test Liquid
Grade            (Volume Ratio %)
10               IPA 100
9                IPA 90/WATER 10
8                IPA 80/WATER 20
7                IPA 70/WATER 30
6                IPA 60/WATER 40
5                IPA 50/WATER 50
4                IPA 40/WATER 60
3                IPA 30/WATER 70
2                IPA 20/WATER 80
1                IPA 10/WATER 90
W                WATER 100
0                Inferior to w

Oil Repellency

According to AATCC-TM118-1992, several droplets (diameter: 4 mm) of the test liquid shown in Table 2 are positioned on two sites of test fabric and penetration states of the test liquid are determined after 30 seconds. The oil-repellency is expressed by the oil-repellency grade shown in Table 2

TABLE 2
Oil		Surface Tension
Repellency		(Dyne/cm,
Grade	Test Solution	25° C.)
8	n-Heptane	20.0
7	n-octane	21.8
6	n-decane	23.5
5	n-dodecane	25.0
4	n-tetradecane	26.7
3	n-hexadecane	27.3
2	n-hexadecane:Nujol (35:65)	29.6
1	Nujol	31.2
0	Inferior to 1	—

Preparation of Repellent Composition

EXAMPLE 1

• 1. Perfluoroalkylethyl acrylate C_nF_2n+1CH₂CH₂OCOCH═CH₂, mixture of n=6-16, average value of n=9, 150 g
• 2. Stearyl acrylate, 53.5 g
• 3. Hydroxyethylacrylate, 10 g
• 4. Stearyltrimethyl ammonium chloride, 5 g
• 5. Dodecyl mercaptan, 0.5 g
• 6. Deionized water, 200 g
• 7. Dipropylene glycol, 98 g
• 8. Azobisisobutylamidine dihydrochloride, 0.85 g

Components 1-7 were charged into a 1 L autoclave and emulsified at 75° C. for 20 minutes by sonification. Under nitrogen cover, component 8 was added and the reaction was continued for 8 hours to give an aqueous water and oil-repellent dispersion.

EXAMPLE 2-4

Procedure of Example 1 was repeated with different emulsifying quaternary ammonium compounds:

Example Surfactant
2       Dioctadecyldimethylammonium chloride
3       Benzyldodecyldimethylammonium chloride
4       Lauryltrimethylammonium chloride

Preparation of Treating Solution

A treating solution for processing was prepared by adjusting a water and oil-repellent composition (Examples 1-4) with water in such a manner as to make a non-volatile content concentration 1% w/w.

Preparation of Cloth for Evaluating Water and Oil-Repellency

An undyed mercerized cotton (100%) broadcloth was dipped in a treating solution, and the wet cloth thus dipped was subjected to squeezing between two rubber rollers in such a manner as to make a wet pickup 70% w/w/. The cloth thus treated was dried at 110° C. for 200 seconds and was then heat-treated at 180° C. for 180 seconds to prepare a test cloth.

TABLE 3
Water and Oil Repellency
	Initial	Durability
	HL 0	HL 3
	Water	Oil	Water	Oil
Example	Repellency	Repellency	Repellency	Repellency
1	10	6	8	4
2	10	7	8	4
3	10	7	8	4
4	10	6	8	4
Note:
HL-0: initial (Before washing and cleaning)
HL-3: After 3 hand washes

Effects of Invention

According to the present invention, the aqueous water and oil-repellent composition is disclosed having durable water and oil repellency and excellent storage stability.

Claims

1. An aqueous water and oil repellent composition which comprises:

a. An acrylate or methacrylate copolymer containing perfluoroalkyl or perfluoroalkenyl group.

b. A surfactant comprising a quaternary ammonium compound

c. An aqueous medium containing an organic co-solvent

2. The composition of claim 1 wherein said copolymer compound comprises a repeat unit derived from a fluoroalkyl group-containing monomer, a fluoroalkyl group containing maleate or fumarate.

3. A method of manufacturing said copolymer of claim 1 wherein a perfluoroalky or perfluoroalkenyl group monomer is polymerized with ethylenically unsaturated monomers, mixed with a chain transfer agent, said surfactant of claim 1 and emulsified in the medium of an organic cosolvent.

4. The method of claim 2 wherein said perfluoroalkyl or perfluoroalkenyl group containing acrylate or methacrylate groups is selected from the group of compounds comprising:

a. CF3(CF2)7(CH2)10OCOCH═CH2,

b. CF3(CF2)7(CH2)10OCOC(CH3)═CH2,

c. CF3(CF2)6CH2OCOCH═CH2,

d. (CF3)2CF(CF2)10(CH2)2OCOCH═CH2,

e. (CF3)2CF(CF2)6(CH2)OCOC(CH3)═CH2,

f. (CF3)2CF(CF2)8(CH2)2OCOC(CH3)═CH2,

g. CF3CF2(CF2)6(CH2)2OCOCH═CH2,

h. CF3CF2(CF2)8(CH2)2OCOCH═CH2,

i. CF3CF2(CF2)10(CH2)2OCOCH═CH2,

j. CF3CF2(CF2)6(CH2)2OCOC(CH3)═CH2,

k. CF3CF2(CF2)10(CH2)2OCOC(CH3)═CH2,

l. CF3(CH2)7SO2N(CH3)(CH2)2OCOCH═CH2, and

m. (CF3)2CF(CF2)6CH2CH(OH)CH2OCOCH═CH2

5. The method of claim 2 wherein the concentration of said perfluoroalkyl or perfluoroalkenyl group is 40 to 95% by weight.

6. The method of claim 2 wherein polymerization is carried out within the temperature range of 50 to 160° C.

7. The method of claim 2 wherein said ethylenically unsaturated monomer is selected from a group comprising (a) acrylic acid and methacrylic acid, and methyl, ethyl, propyl, 2-ethylhexyl, hexyl, decyl, lauryl, cetyl, stearyl, isobornyl, β-hydroxyethyl, glycidyl, phenyl, benzyl esters thereof (b) vinyl esters of fatty acid, propionic acid, caprylic acid, lauric acid and stearic acid (c) styrene compounds (d) vinyl halides (e) vinyl alkyl ketones (f) acryl amides and (g) dienes.

8. The method of claim 1 wherein said chain transfer agent is selected from a group comprising mercaptans or alkyl mercaptans.

9. The method of claim 2 wherein said organic solvent is selected from a group comprising propylene glycol, dipropylene glycol and dipropylene glycol mono-methyl ether.

10. The composition of claim 1 wherein said quaternary ammonium compound is selected from a group comprising of dialkyl(C12-C22)dimethyl ammonium chloride, alkyldimethyl benzayl ammonium chloride, octadecyltrimethyl ammonium chloride, dialkyl(tallow)dimethylammonium chloride, dodecyltrimethylammonium chloride, hexadecyltrimethyl ammonium chloride, biphenyltrimethylammonium chloride, alkylimidazoline quaternary salt, octadecyldimethylbenzylammonium chloride, polyoxyethylenedodecylmonomethylammonium chloride and 1-hydroxyethyl-2-alkylimidazoline quaternary salt.

11. The composition of claim 1 wherein the concentration of said of quaternary compound is from 0.01 to 10 parts by weight of the polymer.

12. A method of processing a textile, comprising treating the textile with said repellent composition according to claim 1, comprising steps of: (1) preparing a treatment composition by diluting said repellent, (2) applying the treatment composition to a textile, and (3) washing the textile with water and (4) dehydrating the textile.

13. The method of claim 10 wherein said treatment composition is dilute to 0.1 to 3% using water.