Water-and oil-repellent composition

Description

BACKGROUND OF THE INVENTION

Field of the Invention

[0001] The present invention relates to an economical water- and oil-repellent composition having good water- and oil-repellency.

Description of the Related Arts

[0002] A water- and oil- repellent having a fluoroalkyl group has better properties than other conventional water- and oil-repellent, and is widely used. However, it is rela­tively expensive. In order to decrease the cost, it is proposed to replace a part of the water- and oil repellent having the fluoroalkyl group with a cheap acrylic acid base polymer or polyhydric alcohol such as sorbitol and lactose while keeping the water- and oil-repellency (cf. Japanese Patent Publication Nos. 22487/1963, 8579/1966 and 4160/1978). Although reduction of the cost is achieved to some extent while keeping the water- and oil- repellency, the above proposal is not satisfactory.

SUMMARY OF THE INVENTION

[0003] An object of the present invention is to provide an economical water- and oil-repellent composition having sufficient water- and oil-repellency.

[0004] This and other objects of the present invention are achieved by a water- and oil-repellent composition which comprises a water- and oil-repellent having a fluoroalkyl group, and a glycerol compound selected from the group con­sisting of glycerol, an ester derivative of glycerol, an ether derivative of glycerol and polyglycerol having a melting point of lower than 70°C.

DETAILED DESCRIPTION OF THE INVENTION

[0005] The ester derivative of glycerol is preferably an ester prepared by esterifying a hydroxyl group at the α-­position with a monoalkane acid having 1 to 6 carbon atoms, for example, glycerol α-monoacetate, glycerol α-monoformate and glycerol α-mono-n-hexanoate. The ether derivative of glycerol is preferably an ether prepared by substituting a hydrogen of a hydroxyl group at the α-position with an alkyl group having 1 to 6 carbon atoms, for example, glycerol α-­monomethyl ether, glycerol α-monoethyl ether and glycerol α-­monoisopropyl ether.

[0006] In the composition of the present invention, a ratio of the glycerol compound to the water- and oil-­repellent is not critical and varies in a wide range dependent on other conditions such as the kinds of the water- and oil-repellent and the glycerol compound. When rhe amount of the glycerol compound is too large, the water- and oil-repellent composition has deteriorated properties. When the amount of the glycerol compound is too small, the cost is not reduced and the water- and oil-repellency is not improved. Accordingly, the glycerol compound is usually used in an amount of 0.05 to 7 parts by weight, preferably 0.1 to 4 parts by weight per one part by weight of the water- and oil-repellent.

[0007] The amount of the water- and oil-repellent having the fluoroalkyl group is not limited. The water- and oil-­repellent having the fluoroalkyl group is usually used in an amount of 0.1 to 1.0 per 100 parts by weight of a medium.

[0008] The water- and oil-repellents include a homopolymer of an acrylate or methacrylate having a fluoroalkyl group having 4 to 21 carbon atoms and a copolymer thereof with a monomer having no fluoroalkyl group (cf. for example, Japanese Patent Publication 8068/1985).

[0009] Preferable acrylate and methacrylate having the fluoroalkyl group are as follows:
R_f(CH₂)_mOCOCR¹=CH₂ and
R_fSO₂NR²(CH₂)_mOCOR¹=CH₂
wherein R_f is a perfluoroalkyl group having 4 to 21 carbon atoms, R¹ is hydrogen or a methyl group, R² is an alkyl group having 1 to 10 carbon atoms, and m is an integer of 1 to 10.

[0010] Specific examples of the acrylate and methacrylate having the fluoroalkyl group are as follows:
CF₃(CF₂)₇(CH₂)₁₁OCOCH=CH₂
CF₃(CF₂)₄CH₂OCOC(CH₃)=CH₂
CF₃(CF₂)₆(CH₂)₂OCOC(CH₃)=CH₂
CF(CF₃)₂(CF₂)₆(CH₂)₃OCOCH=CH₂
CF(CF₃)₂(CF₂)₁₀(CH₂)₃OCOCH=CH₂
CF₃(CF₂)₇SO₂N(C₃H₇)(CH₂)₂OCOCH=CH₂
CF₃(CF₂)₇SO₂N(CH₃)(CH₂)₂OCOC(CH₃)=CH₂
CF(CF₃)₂(CF₂)₆CH₂CH(OH)CH₂OCOCH=CH₂
CF(CF₃)₂(CF₂)₆CH₂CH(OCOCH₃)OCOC(CH₃)=CH₂
CClF₂(CF₂)₁₀CH₂OCOC(CH₃)=CH₂
H(CF₂)₁₀CH₂OCOCH=CH₂
In addition to the above, the monomer having the fluoroalkyl group of the formula:
CF(CF₃)(CClF₂)(CF₂)₇CONHCOOCH=CH₂
can be used alone or in addition to the above methacrylate or acrylate.

[0011] Specific examples of the monomer having no fluoro­alkyl group are ethylene, vinyl acetate, vinyl fluoride, vinyl chloride, vinylidene fluoride, vinylidene chloride, acrylonitrile, styrene, α-methylstyrene, p-methylstyrene, acrylic acid and alkyl esters thereof, methacrylic acid and alkyl esters thereof, acrylamide, diacetone acrylamide, methylol diacetone acrylamide, methylol diacetone methacryl­amide, vinyl alkyl ether, vinyl alkyl ketone, butadiene, isoprene, chloroprene, glycidyl acrylate, maleic anhydride and the like. The monomer having no fluoroalkyl group is usually used in an amount of 0 to 75, preferably 20 to 65 parts by weight per 100 parts by weight of the polymer.

[0012] The homopolymer and copolymer of the above acrylate and methacrylate may be prepared by bulk polymeri­ zation, solution polymerization, emulsion polymerization and the like. The emulsion polymerization is usually preferable. Accordingly, a medium is usually water. The emulsion polymerization uses no specific procedure. For example, as described in Japanese Patent Publication No. 8068/1985, a mixture of monomers is emulsified in the presence of a surfactant and a polymerization initiator, and then polymerized at 50 to 100°C with stirring. The initiator includes a peroxide, an azo compound and a persulfate. As the surfactant, any of anionic, cationic and nonionic surfactants can be used. A mixture of at least one cationic surfactant and at least one nonionic surfactant is preferable.

[0013] The composition of the present invention may include conventionally used additives, for example, a cross­linking agent, an antistatic agent, a dye fixing agent, an anticrease agent, a flame retardant, a mothproofing agent and the like, and it may include general-purpose organic solvents, for example, isopropanol and the like.

[0014] The water- and oil-repellent composition of the present invention may be applied on a material to be treated by conventionally known methods such as spraying, dipping and the like.

[0015] The materials to be treated include natural and synthetic fibers and textiles. An adsorption amount of the water- and oil-repellent to the material to be treated is preferably 0.01 to 2% by weight based on the material to be treated.

[0016] When a polyhydric alcohol, an ester or ether derivative of the polyhydric alcohol, or polyglycerol having the melting point of not lower than 70°C which is not included in the glycerol compound of the present invention is used in the water- and oil-repellent composition, an effect is observed to some extent but various defects arise. For example, the ester or ether derivative of a polyhydric alcohol having more carbon atoms or hydroxyl groups than glycerol remains in a cloth in a large amount after the water- and oil-repellency treatment, and the water- and oil-repellency property decreases due to hydrophilic hydroxyl groups and lipophilic alkyl groups. In addition, the treated cloth has deteriorated feeling. An ester or ether derivative of a polyhydric alcohol or alcohol having fewer carbon atoms or hydroxyl groups than glycerol cannot increase the water- and oil-repellency. The poly­glycerol having the melting point of not lower than 70°C has the same defects as above.

[0017] The water- and oil-repellent composition according to the present invention is economical since the glycerol compound used as the blending component is more easily available than the conventional blending component which comprises the acrylic resin.

[0018] In addition, when the conventional water- and oil-­ repellent is added in a small amount, the water- and oil-­repellency is usually insufficient. But, according to the present invention, the water- and oil-repellency is sufficient because of the use of the glycerol compound even if the water- and oil-repellent adheres to a cloth in a small amount.

[0019] The present invention will be illustrated by following Examples. The Examples, of course, do not restrict the present invention.

[0020] The water- and oil-repellent composition was evaluated as follows:

[0021] The warer repellency is expressed by the water repellency No. of Table 1 determined by the spray method according to JIS (Japanese Industrial Standard) L-1092. Oil repellency is expressed by the oil repellency No. of Table 2 determined by dropping several drops (diameter: about 4 mm) of a test solvent on two positions of a surface of a test cloth and observing whether the drops are held on the surface for 30 seconds or not. The superscript "+" to the water repellency No. represents that the result is slightly better than said water repellency No.

[0022] Feeling is evaluated by measuring the rigidity and softness of the cloth by the Handle-O-meter method according to JIS L-1096.

[0023] Resistance to washing is expressed by the water- and oil-repellency Nos. which are determined after carrying out five cycles each consisting of washing a cloth treated with the water- and oil-repellent composition at 40°C in water containing 0.3 % by weight of detergent (Zabu-koso XK, manufactured by Kao) with a bath ratio of 1:40 (cloth:washing liquid (g:g)) for 5 minutes by using a domestic washing machine followed by rinsing the cloth for 15 minutes, dehydrating it and drying it at room temperature.

[0024] Resistance to dry cleaning is expressed by the water- and oil-repellency Nos. which are determined by washing a cloth treated with the water- and oil-repellent composition at 30°C in tetrachloroethylene by using a Launder-O-meter followed by drying at room temperature and then measuring the water- and oil-repellency.

Table 1

Water repellency No.	State
100	No wet on the surface
90	Slight wet on the surface
80	Drop like wet on the surface
70	Considerable wet on the surface
50	Wet over the whole surface
0	Complete wet of the surface and backface

Table 2

Oil repellency No.	Test solvent	Surface tension
		(dyne/cm, 25°C)
8	n-Heptane	20.0
7	n-Octane	21.3
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 by weight)	29.6
1	Nujol	31.2
0	Nujol penetrated

Examples 1 to 4 and Comparative Examples 1 to 3

[0025] A water- and oil-repellent used in the water- and oil-repellent composition of the present invention was pre­pared as follows:

[0026] The compound (60 g) of the formula:
(CF₃)₂CF(CF₂CF₂)_nCH₂CH₂OOCCH=CH₂
(mixture of n = 3, 4 and 5 in a weight ratio of 5:3:1),
C₁₈H₃₇OOCCH=CH₂ (38 g), CH₂=CHCOOCH₂CH(OH)CH₂Cl (2 g), pure water (250 g), acetone (50 g), n-dodecyl mercaptan (0.2 g) dimethylalkylamine acetate salt (3 g) and polyoxyethylene­alkylphenol (3 g) were charged in a flask, and stirred at 60°C for one hour under a nitrogen stream. A solution of azobisisobutylamidine hydrochloride (1 g) in water (10 g) was added and the copolymerization was carried out while stirring at 60°C for 5 hours under the nitrogen stream. According to a gas chromatography, a conversion of copolyme­rization was not lower than 99%. From this conversion, a ratio of the repeating units of the resultant copolymer was found to be substantially almost the same as a ratio of the charged monomers. The resultant emulsion contained the copolymer in the solid content of 25 %.

[0027] The emulsion was mixed with the blending components as shown in Table 3 to prepare water- and oil-­repellent compositions.

[0028] Test cloths were a polyester finished yarn woven fabric (hereinafter referred to as PE) and a nylon taffeta fabric (hereinafter referred to as N), and were dipped in the above composition for one minute and squeezed between two rolls so as to adjust the water content at 90 % and 50 %, respectively. Then, they were dried at 110°C for three minutes, PE was thermally treated at 180°C for 40 seconds and N was thermally treated at 170°C for one minute to impart the water- and oil-repellency. The water- and oil-­repellency of the treated cloths were measured. The results are shown in Table 4.

[0029] As is clear from Table 4, when the glycerol compound of the present invention is added to the water- and oil-repellent composition, good water- and oil-repellency is achieved.

Table 3

Example No.	Test cloth	Adhesion of repellent to fabric (wt%)	Blending component	Adhesion of blending component to fabric (wt%)
1	PE	0.03	Glycerol	0.015
	N	0.10		0.05
2	PE	0.03	Glycerol α-monomethyl ether	0.015
	N	0.10		0.05
3	PE	0.03	Glycerol α-monoacetate	0.015
	N	0.10		0.05
4	PE	0.03	Polyglycerol (melting point: 30°C) (molecular weight: 170)	0.015
	N	0.10		0.05
Comp.1	PE	0.03	-	-
	N	0.10		-
Comp.2	PE	0.03	Sorbitol	0.015
	N	0.10		0.05
Comp.3	PE	0.03	Polyglycerol (melting point: >70°C) (molecular weight: 1000)	0.015
	N	0.10		0.05

Table 4

Example No.	Test cloth	Initial	After washing	After dry cleaning	Feeling
		Water repellency/Oil repellency	Water-repellency/Oil-repellency	Water-repellency/Oil-repellency	(blank: 10 g)
1	PE	100⁺/7	50/0	80/3	8
	N	100⁺/2	50/0	70/0
2	PE	100⁺/7	50/0	80/3	8
	N	100⁺/1	50/0	70/0
3	PE	100⁺/6	50/0	80/2	8
	N	100⁺/1	50/0	70/0
4	PE	100⁺/5	50/0	80/20	8
	N	100/0	0/0	70/0
Comp.1	PE	80⁺/5	0/0	70/2	9
	N	80/0	0/0	50/0
Comp.2	PE	90/5	50/0	70⁺/2	12
	N	90/0	50/0	70/0
Comp.3	PE	80⁺/5	0/0	70⁺/2	10
	N	80⁺/0	0/0	50⁺/0

Claims

1. A water- and oil-repellent composition which comprises a water- and oil-repellent having a fluoro­alkyl group, and a glycerol compound selected from the group consisting of glycerol, an ester derivative of glycerol, an ether derivative of glycerol and polyglycerol having a melting point of lower than 70°C.

2. The water- and oil-repellent composition according to claim 1, wherein the ester derivative of glycerol is an ester prepared by esterifying a hydroxyl group at the α-position with a monoalkane acid having 1 to 6 carbon atoms.

3. The water- and oil-repellent composition according to claim 1, wherein the ether derivative of glycerol is an ether prepared by substituting a hydrogen of a hydroxyl group at the α-position with an alkyl group having 1 to 6 carbon atoms.

4. The water- and oil-repellent composition according to claim 1, wherein the water- and oil-repellent is a homopolymer of an acrylate or methacrylate having a fluoroalkyl group having 4 to 21 carbon atoms or a copolymer thereof with a monomer having no fluoroalkyl group.

5. The water- and oil-repellent composition according to claim 1, wherein the composition contains the glycerol compound in an amount of 0.05 to 7 parts by weight per one part by weight of the water- and oil-repellent.