JP3205748B2 - Water and oil repellent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a water / oil repellent.
More specifically, the present invention relates to a water and oil repellent having improved washing durability.

[0002]

2. Description of the Related Art Conventionally, water- and oil-repellents containing a perfluoroalkyl group-containing copolymer as a water- and oil-repellent component have been used to improve the washing durability and the antifouling property, etc. It has been proposed to add and use a compound obtained by blocking a compound with an oxime-based compound (JP-A-61-19684, JP-A-2-209984, etc.).

[0003] When heated, these blocked isocyanate compounds dissociate oxime compounds and return to polyisocyanates. When the returned polyisocyanate is a diisocyanate, one of the isocyanate groups contains OH, NH ₂ , COO in the copolymer as a water / oil repellent component.
H, when it contains active hydrogen groups such as SH _2, reacts with these active hydrogen groups, other isocyanate groups react like with OH groups present in the fiber molecule, a water and oil repellent molecules The fiber molecules are crosslinked to prevent the water / oil repellent from falling off the fibers due to physical external force such as washing.

However, in the case of the oxime block of diisocyanate, the dissociation of the oxime compound is insufficient, that is, a molecule that dissociates only one of the blocks or a molecule that dissociates both is included. In some cases, the oil does not sufficiently contribute to the washing durability.

A similar tendency is observed in the case of the above-mentioned known oxime block of triisocyanate. In particular, the oil repellency tends to decrease remarkably as the number of washings increases.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a water / oil repellent comprising a copolymer containing a perfluoroalkyl group and an active hydrogen group as a water / oil repellent component, to which a blocked isocyanate compound is added. Another object of the present invention is to provide a water and oil repellent having improved washing durability.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
In the above water / oil repellent, a blocked isocyanate compound represented by a general formula (Here, X _{1 to} X ₃ are -ON = CR ₁ R ₂ groups and -O (CH ₂ CH ₂ ) mRf groups having an equivalent ratio of 1 to 5 mixed with each other and substituted, R ₁ and R ₂ are a hydrogen atom or a lower alkyl group, Rf is a fluorocarbon group having 4 to 18 carbon atoms, and n is
0 or a positive integer, preferably 1 to 5, and m is an integer of 1 to 4].

The blocked isocyanate compound represented by the above general formula is represented by the general formula An oxime represented by the general formula R ₁ R ₂ C = NOH,
For example, acetoxime, methyl ethyl ketoxime and the like, acetone, methyl ethyl ketone, diethyl ketone,
After reacting in a solvent such as ketones such as methyl propyl ketone and methyl isobutyl ketone, esters such as ethyl acetate, propyl acetate and butyl acetate, the compound represented by the general formula Rf (C
It is obtained by reacting with a fluorocarbon group-containing alkanol represented by H ₂ CH ₂ ) mOH.

More specifically, diphenyl methane diisocyanate is removed by distilling a commercial product which is a mixture of n = 1, n = 2, n = 3 or more, and the mixture ratio of these is about 40 / 20/40 ~
After dissolving polymethylene polyphenyl polyisocyanate which is 50/15/35 in the above solvent and sufficiently replacing with nitrogen gas, oximes are added dropwise using a dropping funnel, and then the temperature is raised to about 50 to 110 ° C. And react for about 4 to 24 hours. In this case, the oximes can be added dropwise in several stages, in which case the reaction temperature is divided into several stages at a temperature lower than the final temperature and raised to the maximum temperature in the final stage. Then
The fluorocarbon group-containing alkanol dissolved in the ketones as described above was dropped using a dropping funnel, and about 50 to 11
The reaction is carried out at a temperature of 0 ° C. for about 4 to 24 hours. The fluorocarbon group-containing alkanol is used in an amount of about 1 to 5 moles per mole of the oximes. If the molar ratio of the fluorocarbon group-containing alkanol is less than this, the fabric tends to be colored (yellowing) when subjected to water / oil repellent treatment, and the finish is hardened, so that the feel is impaired in terms of flexibility. Become. On the other hand, if it is used in a molar ratio higher than this, the number of cross-linking points decreases, and the washing durability cannot be said to be sufficient. Within such a molar ratio range, the reaction order can be reversed, or the reaction can be carried out simultaneously as a mixture. After completion of the reaction, alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol and isobutanol are added to completely eliminate free isocyanate groups.

The thus obtained blocked isocyanate compound is obtained by removing the reaction solvent from the reaction mixture, drying the mixture, and adding a surfactant, preferably a nonionic surfactant and water, to the blocked isocyanate compound. Is dispersed, the solid content concentration is about 10 to 50% by weight, preferably about 2%.
Used as a stable aqueous dispersion of 0-45% by weight.

The copolymer as a water / oil repellent component to which the blocked isocyanate is added as an aqueous dispersion contains a perfluoroalkyl group and an active hydrogen group.

The perfluoroalkyl group is a polymerizable monomer containing a perfluoroalkyl group having 6 or more carbon atoms, for example, Is introduced by copolymerizing about 50 to 90% by weight, preferably about 60 to 90% by weight.

The active hydrogen group may be a polymerizable monomer having at least one of a hydroxyl group, a carboxyl group, an amide group, an imide group and the like as exemplified below in an amount of about 25 to 1% by weight, preferably about 25 to 1% by weight. It is introduced by copolymerizing about 10 to 3% by weight.・ Hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate ・ Polyalkylene glycol mono (meth) acrylates such as polyethylene glycol mono (meth) acrylate and polypropylene glycol mono (meth) acrylate ) Acrylates ・ CH ₂ ＝ CHCOOCH ₂ CH ₂ OCOCH ₂ CH ₂ COOH and other carboxyl group-containing acrylates ・ N-methylol acrylamide, N-ethylol acrylamide and other hydroxyl group-containing acrylamides ・ CH ₂ = CHCONHCH ₂ CH ₂ NHCH _{3 and} other iminos Group-containing acrylamide

[0014] In these copolymers, at least one other vinyl monomer may be further copolymerized within a range that does not impair the properties thereof, generally at a ratio of about 40% by weight or less. it can. Such vinyl monomers include, for example, vinyl chloride, vinylidene chloride, benzyl (meth) acrylate, stearyl (meth) acrylate, acrylonitrile, vinyl acetate, acrylamide and the like.

The copolymerization reaction is carried out by an emulsion polymerization method, and the obtained latex is used as it is or diluted with water to give a solid content of about 10 to 40% by weight, preferably about 15 to 30% by weight. Used for the preparation of water and oil repellents.

The water- and oil-repellent agent is prepared by mixing a copolymer latex and an aqueous dispersion of a blocked isocyanate compound with each other in a solid content of about 50 to 90% by weight and about 50 to 10% by weight, respectively.
%, Preferably about 55-80% by weight and about 45-20% by weight.

The water- and oil-repellent treatment using the water- and oil-repellent agent thus prepared is performed by adding the water- and oil-repellent agent to about 0.5 to 2% by weight.
%, And then immersed the object in this diluted solution and squeezed as necessary.
The heat treatment is performed for about 30 to 180 seconds. At that time, it is preferable to dry at about 80 to 110 ° C. for about 3 to 10 minutes before the heat treatment.

[0018]

In the water / oil repellent according to the present invention, an (oxime-fluorocarbon group-containing alkanol) block of polymethylene polyphenyl polyisocyanate containing three or more isocyanate groups is used as a blocked isocyanate compound. Therefore, even at a low temperature of about 130 to 170 ° C. and a short heat treatment time of about 30 to 90 seconds, at least two isocyanate groups required for crosslinking are activated hydrogen groups in the water / oil repellent component copolymer. And it easily reacts with the hydroxyl group in the fiber molecule to exhibit excellent washing durability. Further, by increasing the heat treatment temperature or lengthening the treatment time, the washing durability is further improved.

Specifically, when a blocked isocyanate compound containing a diisocyanate group is used, after a drying step at 80 ° C. for 10 minutes, a 170 ° C.
C, 90 seconds, the polyester / cotton blend fabric requires a heat treatment of 150 ° C, 180 seconds, whereas by using the blocked isocyanate compound of the present invention, 80 ° C,
Even if the drying step for 10 minutes is omitted, almost the same water repellency is exhibited, and the effects of energy saving and cost reduction are brought about. In addition, after the drying step, a water repellency of 100 can be obtained even after washing 30 times, which was impossible in the past. Moreover, since the blocked isocyanate compound used in the present invention has a fluorocarbon group, it not only has water / oil repellency itself, but also has a cloth treated with a water / oil repellent prepared using the same. Has a low degree of discoloration (yellowing) and is also excellent in terms of texture such as smoothness and softness.

[0020]

Next, the present invention will be described by way of examples. Reference Example 1 In a separable flask equipped with a stirrer, a condenser and a thermometer, 91.8 g of polymethylene polyphenyl polyisocyanate (a mixture of n = 1, n = 2, n = 3 or more of 50/15/35) and acetone were added. After charging 227.5 g, the air was replaced with nitrogen for about 30 minutes.

Then, 33.5 g of methyl ethyl ketoxime
(0.384 mol) was added dropwise using a dropping funnel, and the mixture was heated to 55 ° C. and reacted for 7 hours. Thereafter, 125.0 g (0.270 mol) of 2-perfluoroalkyl ethanol (a mixture of 10% of C ₆ F ₁₃ , 70% of C ₈ F _{17 and} 20% of C ₁₀ F ₂₁ ) was added dropwise, while maintaining the temperature at 55 ° C. For about 6 hours. Finally, 5 g of methanol was added, and it was confirmed by infrared absorption spectrum and gas chromatography that no isocyanate group remained.

Acetone was removed from the reaction product solution, and to 35 parts by weight of dried product, 5 parts by weight of polyethylene glycol alkyl ether (HLB 11) and 60 parts by weight of water were added, and the mixture was stirred for about 24 hours with a ball mill. And solids concentration 40
A very stable aqueous dispersion of blocked isocyanate was prepared having a weight percent of 1.0 μm average particle size and a pH of 6.5.

Reference Example 2 In a separable flask equipped with a stirrer, a condenser and a thermometer, 7.5 g of nonionic surfactant (HLB 18), perfluoroalkylethyl acrylate (perfluoroalkyl group was C ₈ 70%, C 70 g, a mixture of ₁₀ 25% and C ₁₂ 5%)
Vinylidene chloride 10 g, benzyl methacrylate 20 g, 2-hydroxyethyl acrylate 5 g, acetone 75 g and water 2
After charging 50 g and keeping the temperature at 40 ° C. with stirring, a sufficient nitrogen atmosphere was added, and 2.5 g of 2,2′-azobis (2-aminodipropane) dihydrochloride was added, and the temperature was raised to 70 ° C. For 4 hours. A quaternary copolymer latex having a solid content of 26% by weight was obtained, and this latex had good transparency. In the following examples, this was diluted with water and adjusted to a solid content concentration of 25% by weight for use.

Example 1.5 parts by weight of the aqueous blocked isocyanate dispersion obtained in Reference Example 1 and 3.5 parts by weight of the quaternary copolymer latex obtained in Reference Example 2 were mixed, and water was added to obtain 100 parts by weight. To prepare a water and oil repellent.

A nylon cloth (N) or a polyester / cotton blended cloth (T / C) is immersed in the water / oil repellent for 5 seconds and then squeezed with a mangle. The squeezing rate is 45% by weight of the nylon cloth.
The blended fabric was 60% by weight.

A general heat treatment and a short-time heat treatment were applied to these drawn cloths. (General heat treatment) Nylon cloth: Dry at 80 ° C for 10 minutes, heat treat at 170 ° C for 30 seconds Blended cloth: Dry at 80 ° C for 10 minutes, heat treat at 150 ° C for 3 minutes (short-time heat treatment) Nylon cloth: 170 Heat treated at 150 ° C for 30 seconds Blended fabric: Heat treated at 150 ° C for 90 seconds

The water- and oil-repellent treated and heat-treated cloth was washed 10 times, 20 times or 30 times and dried at room temperature to obtain water repellency (by the spray method of JIS L-1092) and water repellency. Oiliness (according to AATCC Test Method 118) was measured. The results obtained are shown in Table 1 below. (Margins below) Table 1 Washing frequency heat treatment cloth test 0 10 20 30 General N water repellency 100 100 100 100 Oil repellency 6 4 4 3 T / C water repellency 100 100 100 100 Oil repellency 6 5 5 5 Short time N water repellency 100 100 100 90 Oil repellency 5 4 2 2 T / C Water repellency 100 100 100 90 Oil repellency 5 5 4 3

Comparative Example 1 In the examples, an aqueous dispersion of a methylethylketoxime block of diphenylmethane diisocyanate prepared in the same manner was used in place of the aqueous dispersion of blocked isocyanate obtained in Reference Example 1. The water repellency and oil repellency test results are shown in Table 2 below. Table 2 Number of Washing Tests of Heat-treated Cloth 0 10 20 30 General N Water Repellency 100 100 100 80 Oil Repellency 6 3 2 0 T / C Water Repellency 100 100 100 90 Oil Repellency 6 5 5 4 Short Time N Water Repellency 100 100 80 70 Oil repellency 5 200 T / C Water repellency 100 100 90 80 Oil repellency 5 4 1 0

Comparative Example 2 In Example, an aqueous dispersion of a blocked isocyanate represented by the following formula (solid content: 4.0% by weight) was used instead of the aqueous dispersion of blocked isocyanate obtained in Reference Example 1.
%, PH 6) was used. The test results of the water repellency and oil repellency are shown in Table 3 below. Table 3 Number of Washing Tests on Heat-treated Cloth 0 10 20 30 General N Water Repellency 100 100 90 70 Oil Repellency 6 3 1 0 T / C Water Repellency 100 100 100 80 Oil Repellency 6 5 3 2 Short Time N Water Repellency 100 100 80 70 Oil repellency 5 200 T / C Water repellency 100 100 90 70 Oil repellency 5 4 1 0

Using the spectrophotometer (CM-1000 manufactured by Minolta), the yellow value of the treated cloths of the above Examples and Comparative Example 1 (water-repellent and oil-repellent treated cloths subjected to general heat treatment before washing) was measured. The indicated Δb value was determined, and the degree of discoloration (degree of yellowing) was measured. In this case, the larger the Δb value, the larger the yellowing degree.
The results obtained are shown in Table 4 below. (Hereinafter the margin)

When the feeling of touch of these treated cloths was determined by 10 persons, eight persons for nylon cloth, all persons for blended cloth, and the treated cloth of the example were better than those of comparative example 1. It is judged that it was softer than that.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Eiji Arakawa 831-2 Kamiida, Isohara-cho, Kitaibaraki-shi, Ibaraki NOK Cruaver Co., Ltd. In-house (56) References JP-A-63-146976 ( JP, A) JP-A-63-90587 (JP, A) JP-A-59-145274 (JP, A) JP-A-4-214469 (JP, A) JP-A-62-16454 (JP, A) (58) ) Surveyed field (Int.Cl. ⁷ , DB name) D06M 13/00-15/715

Claims (1)

(57) [Claims] 1. A water / oil repellent comprising a copolymer containing a perfluoroalkyl group and an active hydrogen group as a water / oil repellent component, and a blocked isocyanate compound added thereto. As a compound,
General formula (Here, X _{1 to} X ₃ are -ON = CR ₁ R ₂ groups and -O (CH ₂ CH ₂ ) mRf groups having an equivalent ratio of 1 to 5 mixed with each other and substituted, R ₁ and R ₂ are a hydrogen atom or a lower alkyl group, Rf is a fluorocarbon group having 4 to 18 carbon atoms, and n is
0 or a positive integer, and m is an integer of 1 to 4].