CA1326732C

CA1326732C - Water and oil repellant having desoiling properties

Info

Publication number: CA1326732C
Application number: CA000580618A
Authority: CA
Inventors: Tomoko Sakaguchi; Kazuya Oharu; Takashige Maekawa
Original assignee: Asahi Glass Co Ltd
Current assignee: AGC Inc
Priority date: 1987-10-20
Filing date: 1988-10-19
Publication date: 1994-02-01
Anticipated expiration: 2011-02-01
Also published as: US4859754A; EP0312964A2; AU602430B2; EP0312964A3; DE3856225D1; JP2508760B2; EP0312964B1; DE3856225T2; AU2404188A; JPH01108290A

Abstract

ABSTRACT
A water and oil repellant having desoiling properties composed of a polyfluorinated group-containing copolymer obtained by copolymerizing the following monomers a and b as essential constituting components:
a: a polyfluorinated group-containing monomer b: an amphipathic monomer having a hydrophilic moiety and a lipophilic moiety.

Description

`` ` 1 3~673~

Our Ref: AA-504 (F88-40) WATER AND OIL REPELLANT HAVING DESOILING PROPERTIES
The present invention relates to a high performance water and oil repellant which is capable of providing excellent desoiling properties, while maintaining high water repellency.
Heretofore, water and oil repellants composed of polymers or copolymers of a polyfluorinated group-containing monomer such as a per~luoroalkyl acrylate have been widely known. For example, Japanese Unexamined Patent Publications No. 75472/1974, No. 20991/1975, No.
134786/1978 and No. 1347~7/1978 and US Patents 3,654,244 and 3,9Z0, 614 propose water and oil repellants composed of copolymers obtained by copolymerlzing a hydrophilic group-containing monomer to a polyfluorinated group-containing monomer for -the purpose of imparting desoiling properties whereby deposited stains can readily be removed e.g~ by washing (generally called desoiling or soil-removing properties or SR properties).
The above-mentioned conventional SR type water and oil repellants are usually inadequate in the water repelle and at the same time have the following dif~iculties with respect to the SR properties. Namely, a deterioration is observed in the effect for providing water repellency after the washing treatment, and the desoiling properties after exposed to a severe condition tend to be inade~uate, thus leading to pra~tical difficulties. For example, with conventional SR type water and oil repellants, the SR
prop~rties are inadequate against stains adhered during the wearing for a relatively lon~ period of time, or against stains left adhered for a long period of time since their deposition until the washing operation, although they are capable of exhibiting adequate SR properties against a low level of stains.
In order to solve such a proble~, the present applicant has pr~viously proposed a watex and oil repallant composed of a copolymer obtained by copolymerizing a high Tg ~ethacrylate monomer at a specific copolymerization ratio as a third component to a polyfluorinate~ group-containing monomer/a hydrophilic group-containing monomer. (See Japanese Unexamined Publication No. 27585/February 5, 1988.) From a further research, the present inventors have found the following problem with the above-mentioned copolymerization system of a polyfluorinated group-containing monomer/a hydrophilia group-containing monomer. Namely, with the above-mentioned copolymerization system, although high per~ormance may be obtained by solution polymerization, it i~

` ~

di~ficult to smoothly conduct th~ copolymerization reaction of the polyfluorinated group-containing monomer and the hydrophilic group-containing monomer by copolymerization ~n an aqueous dispersion system such a6 by emul~ion polymerization. Accordingly, it used to be difficult to attain high levels o water and oil repellency and SR
properties.
The pre~ent invention overcomes or at least mitigate~
bo~h of th~ above-mentioned proble~ inherent to conventional SR type water and oil repellant~ and provides a SR type water and oil repellant which i~ capable of providing adequate SR
properties against heavy stains and which has high water repellency.
As a rssult of various researches and ~tudies the present inventors have made the following v~ry interesting disc~veries. Na~ly, it has be~n found possible to 6~00thly and advantageously conduct the copolymeriæation reaction not only by solution pol~erization but al~o by polymeriz~ion in an aqueous dispersion system such as by emul ion polymerization, by employing ~n amphipathic monomer having not only a hydrophilic moiety but also a lipophilic moieky in the ~ole~ule, as a ~onomer to be copolymeri~ed with the polyfluorinated group~containing ~ono~er. Further, it has been ~ound that by employing such an amphipathic monomert ~xcellent SR properties can be obtained while maintaining the water and oil repellency, and even by the polymerization in an aqueous dispersion system, i-t is possible to obtain both the water and oil repellency and the SR properties, which used to be difficult to at-tain simultaneously.
The present invention has been accomplished on the basis of the above-mentioned discoveries and provides a water and oil repellant having desoiling properties composed of a polyfluorinated group-containing copolymer obtained by copolymerizing the following monomers a and b as essential cons-tituting components:
a: a polyfluorinated group-containing monomer b: an amphipathic monomer having a hydrophilic moiety and a lipophilic moiety.
Now, the present invention will be described in detail with reference to the preferred embodiments.
In the novel water and oil repellant of the present invention, it is preferred that the weight ratio of a/b in the polyfluorinated group-containing copolymer is 65-95/5-35, and the total conten-t of a and b in the copolymer is at least 80% by weight.
In the present inventionl the polyfluorinated group-containing monomer may be an acrylate or methacrylate containing a terminal perfluoroalkyl group having from 3 to 20 carbon atoms, preferably from 6 to 14 carbon atoms, such as CF3(cF2)7cH2cH2ococH=

1 32~732 CF3(CF2)4CH20COC(CH3)=CH2, ( 3)2CF(CF2)6(CH2)30COCH=CH2~

( 3)2CF(CF2)~(CH2)30COC(CH3)=CH2, ( 3)2cF(cF2)lO(cH2)3ococH=cH
CF3(CF2)6(CH2)20COC(CH3)=CH2~
( F3)2CF(CF2)5(CH2)20COCH=CH2, 3(CF2)7S02N(C3H7)(cH2)2ococ(c~3)=cH2r C~3(cF2)7(cH2)4ococH=cH2t 3( F2)7S02N(C3H7)(c~2)2ococH(CH3 )=CH2 or ( 3 )2CF(CF2)6CH2CH(OH)CH2OCOCH=CH2.
A fluoroalkyl group-containing polymerizable compound such as H(CF2)10CH~OCOCH=CH2 or CF2Cl(CF2)10OCOCH=CH2 may also be mentioned. However, the above-mentioned monomer having a terminal perfluoroalkyl group is preferred from the viewpoin-t of the water and oil repellency.
In the present invention, the amphiphatic monomer having a hydrophilic moiety and a lipophilic moiety is the one having, as the hydrophilic moiety, a non-ionic group such as a polyoxyethylene chain, an anionic group such as a sulfonic acid group or a carboxylic acid group, or a cationic group such as an ammonium salt or an amine salt, and, as the lipophilic moiety, a polyoxypropylene chain, a polyoxybutylene chain or an alkylene chain. Usually, an amphipathic monomer having a hydrophilic-lipophilic balance (HLB) of hydrophilic moiety/lipophilic moiety being from 5 to 15 is selected. In the present invention, it is particularly preferred to employ a mixed polyoxyalkylene chain-containing amphiphatic monomer which has, as the hydrophilic moiety, a polyoxyethylene chain and, as the lipophilic moiety, a polyoxypropylene chain capable of con-trolling the crystallinity of the polyoxye-thylene chain. Namely, such a mixed polyoxyalkylene chain-containing amphipathic monomer is advantageous from the viewpoint of the reactivi-ty for the copolymerization with the polyfluorinated group-containing monomer and the availability. It is also excellent in providing high perormance of the SR properties and the _ water and oil repellency simultaneously. Particularly preferred as such an amphipathic monom,er is an acrylate or methacrylate of the formula:
CH2=C(R )CO2 [(C3H6)m(c2H4o)n] R
wherein Rl is H or CH3, R2 is H or a C1-C20 alkyl or aralkyl group, m 2 l, n > l, and 60 > m ~ n > 2.
In the present invention, the amphiphatic acrylate or methacrylate having the above formula is preferably selected from those having a polyoxyalkylene chain moiety with HLB of rom 5 to 15. It is usual to employ the one wherein m ~ n = 5 to 30, and m/n = l/4 to 4/l, preferably ', 1/2 to 2/l. Rl may be H or CH3, but R2 is preferably a C1-~20 alkyl group rather than H. For example, R is preferably a methyl group or a C2-Cl~ alkyl group.
,' 25 In the specified copolymer of the present invention, , the weight ratio of the polyfluorinated group-containing monomer ~component a)/the specified amphipathic monomer (componen-t b) is usually from 65-95/5-35, preferably 70-90/lO-30, and the total content of components a and b in the copolymer is usually at least 80~ by weight, preferably at least 85% by weight.
In the present invention, in addition to the above-mentioned essential components a and b, one or more additional monomers such as a monomer having a cross-linking group or an adsorption group to fibers, a high Tg monomer for improving the film-forming property, or a low Tg monomer for improving the flexibility of the coating film, may be incorporated wi-thout any particular restriction.
To obtain the copolymer of the present invention, various systems and conditions for the polymerization reaction may be employed, and any of various . .
polymerization systems such as bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, radiation polymerization and photo polymerization may be employed. As the polymerization initiating source, various polymerization init-i-ators such as an organic peroxide, an azo compound and a persulfate as well as ionized radiation such as y-raysr may be employed. As an emulsifier for emulsion polymerization, almost all emulsifiers including anionic, cationic and non-ionic emulsifiers may be used. Thus, it is possible that the polymerizable compound as the starting material is dissolved in an organic solvent and polymerized by solution polymerization by the action of a polymeriza-tion initiating source (such as a peroxide or azo compound soluble in the organic solvent used, or ionized radiation). The solvent suitable for the solution polymerization includes trichlorotrifluoroethane, tetrafluorodifluoroethane, methylchloroform, ethanol, isopropanol and a solvent mixture thereof.
With respect to the composition of the organic solution thus obtained, there is no particular restriction as to the concentration of the specified copolymer in the organic solvent. Usually, however, satisfactory -properties can be imparted in the treatment of fiber fabrics if the concentration is at least about 0.05% by weigh-t. Further, it is possible to prepare -the lS composition in the form of a concentrated solution having a concentration of ~rom 4 to 50% by weight, preferably from 6 to 35% by weight, so that it will be diluted for use to a concentration of from 0.05 to 4% by weight, preferably from 0.3 to 1.5% by weight. Thus, the concentration of the specified copolymer can be adjusted withi-n a wide range of from 0.05 to 50% by weight, preferably from 0.3 to 35% by weight. If the concentration is too low, the effect for imparting the desired properties will be inadequate, and if the concentration is too high, it will be difficult to obtain a uniform solution.
Further, in the present invention, it is possible that g the organic solution is prepared as described above, then a propellant such as dichlorofluoromethane, monofluorotrichloromethane, dichlorotetrafluoroethane, propane, butane, vinyl chloride, dimethyl ether, CO2 or N2O is added thereto, and the mixture is filled in a container to obtain an aerosol.
The feature of the present invention is significant particularly in the polymerization in an aqueous dispersion system. Namely, the copolymerization system of the present invention may be a solution polymeriza-tion system as described above in which a high performance can of course be obtained~ However, according to the present invention, the water and oil repellency and the SR
properties can be attained simultaneously even in the aqueous dispersion system, in which the conventional SR
type wa-ter and oil repellant can hardly attain the desired properties. It presents a significant advantage in the industrial operation that high performance can be obtained by an aqueous dispersion system. For example, with such a system, the :Elash point is high as compared with -the organic solvent system, or no flash point exists, the composition of the treating bath can easily be controlled, and no adverse effects will be impartea to the articles to be treated. Usually, the water and oil repellant of the present invention may be prepared in the form of a concentrated aque~us dispersion having a solid concentration of from 5 to 50% by weigh~, preferably from 15 to 30~ by weight, so that it may be diluted at the time of treatment to a concentration of from 0.1 to 5.0% by weight, preferably from 0.3 to 2.0% by weigh-t.
The water and oil repellant of the present invention may be applied -to the articles to be treated by an optional method dependin4 upon the type of the articles to be treated or the above-mentioned preparation system (e.g.
the aqueous dispersion, the solution or the aerosol). For example, in the case of the solution system, it is possible to employ a method wherein the repellan-t is _ deposited on the surface o~ the articles to be treated by a known coating method such as a dip coating method, followed by drying. If necessaryj the repellant is applied together with a suitable cross-linking agent, followed by curing. In the case of the aerosol sys-tem, .
the repellant can simply be sprayed to the articles to be treated, whereupon it is immediately dried to provide adequate properties. In the case of the aqueous dispersion system particularly suitable in the present invention, the articles to be treated are dipped in a treating bath prepared to have ~he above-mentioned solid concentration, then squeezed to a suitable extent so that the latex is deposited on the surface, followed by drying and curing. Also in this case, a cross-linking agent may be incorporated, if necessary.
Further, to the polyfluorinated group-containing specified copolymer, other polymer blenders may be `` 1 326732 incorporated. Further, other water repellants or oil repellants, or optional additives such as insecticides, flame retardants, an-tistatic agents, dyestuffs, stabilizers or crease preventing agen-ts, may be incorporated, as the case requires.
The articles to be treated by the water and oil repellant of the present invention are not restricted to fiber fabrics, and various examples may be mentioned, including glass, paper, wood, leather, fur, asbes-tos, bricks, cement, metals and their oxide, porcelains, plastics, coated surfaces and plasters. As the fibrous fabrics, fabrics made of animal or plant natural fibers such as cotton, wool or silk; various synthetic fibers such as polyamide, polyester, polyvinyl alcohol, lS polyacrylonitrile, polyvinyl chloride or polypropylene;
semisynthetic fibers such as rayon or ace-ta-te; inorganic fibers such as glass fiber or asbestos ~iber; or blends of these fibers, may be mentioned.
In the present invention, the water and oil repellant is believed to provide high water repellency under a normal condition since the polyfluorinated groups such as perfluoroalkyl groups cover tne surface of the clo-th. At the time of washing, however, the hydrophilic moiety contained in the copolymer appears on the surface of the cloth to provide wettability to a soap solution and thereby to improve the desoiling properties. This is believed to be the reason why the water repellency and desoiling properties can be obtained simultaneously.
Further, the amphiphatic monomer exhibits a suitable lipophilic properties during the polymerization, especially during the polymerization in an aqueous dispersion system (such as suspension polymerization or emulsion polymerization), whereby the distribution to the aqueous phase is controlled, and the compatibility with the polyfluorinated group-containing monomer is improved.
Consequently, the random copolymerization proceeds smoothly, and the water and oil repellency and the desoiling properties are believed to be thus obtainable .
simultaneously and advantageously.

However, it should be understood that the above explanation is intended solely to help understand the present invention and by no means restricts the present . .
invention.
Now, the present inven-tion will be described in further detail with reference to Examples. Howev~r, it should be understood that the present invention is by no means restricted by these specific Examples.
-I-n the ~ollowing Examples, the water repellency and the oil repellency are represented by the following standards.
Namely, the water repellency is represented by the water repellency number (see the following Table 1) by the spray method of JIS L-1005. The oil repellency was determined by placing a Eew drops (a diameter oE about mm) of the test solution as shown in the following Table 2, on a sample cloth at two locations, and evaluating the infiltration condition upon expiration of 30 seconds.
(AATCC-TM 118-1966).

Table 1 Water _ repellency State No.
._ .
-15 100 No wetting was observed on the surface.
The surface was slightly we-tted.

The surface was partly soaked.
The surface was soaked.
The entire surface was soaked.
~5 _ The entire clo-th was completely soaked Table 2 Oil Test solution Surface tenOion repellency _ dyne/cm, 25 C

8 n-Heptane 20.0 7 n-Octane . 21.8 6 n-Decane 23.5 n-Dodecane 25.0 ~ n-Tetradecane 26.7 -20 3 n-Hexadecane 27.3 2 Hexadecane 35/Nujol 65 29.6 mixed solution 1 Nu~ol 31.2 . Poorer than 1 - - The tests for desoiling properties (SR properties) were conducted as follows. A sample cloth was placed on a blotting paper spread horizontally, five drops of heavy oil-B were dropped thereon, a polyethylene sheet was placed thereon, an~ a weight of 2 kg was loaded thereon.
60 minutes later, the weight and polyethylene sheet were removed, the excess oil was wiped off, and the sample cloth was left to stand at room temperature for one hour.

Then, the sample cloth and ballast cloth were charged into an electric washing machine with a capacity of 35 liters in a to-tal amount of 1 kg, washed at 40C for 10 minutes by using 60 g of a detergent (Super Zab, trade name), rinsed and dried in air. The stained level of the sample cloth was compared with the photographic standards of AATCC Test Method 130-1970 and the desoiling properties of the sample cloth were represented by the corresponding standard level.

Table 3 Desoiling levels Evaluation standards 1 Remarkable stains were observed.
2 Substantial stains were observed.

3 Slight stains were observed.

4 No substantial stains were observed.
No stain was observed.

The water repellency number, the oil repellency and the SR properties marked with symbol + indicate that the respective properties are slightly better.
Into a glass ampoule having an internal capacity of 100 ml, 8.0 g of CH2=CHCOOC2H4CxF2x+l wherein x is from 6 to 16 and an average of 9 (hereinafter referred to simply as FA), 2.0 g of fH3 CH2=C(CH3)COO(CH2CHO)7(CH2CH2O)gC8H17 ` 1 326732 (hereinafter referred to simply as POEP), 20 g of trichlorotrifluoroethane 0.2 g of azobisisobutyroni-trile and 0.05 g of t-dodecylmercaptan were charged. The gas phase of the ampoule was replaced by nitrogen, and the ampoule was closed, heated and shaked at 60C for 12 hours for copolymerization. The copolymer solution thus obtained was diluted with trichlorotri1uoroethane to obtain a solution having a solid content of 0.6~ by weight. To this diluted solution, a polyester cloth was dipped, then dried in air and subjected to heat treatment at 150C for 3 minutes. The water repellency (WR), the oil repellency (OR) and the SR properties of the treated cloth were measure~. The results are shown in Table 4.

In the same manner as in Example 1, the . .
copolymerization, the preparation of the solution, the trea-tment and the measurement of the properties were conducted except that instead o~ POEP in Example 1, CH2=C(CH3)COO(C2H4O)gCH3 (hereinafter referred to simply as M9OG) was used. The results are shown in Table ~.
EXA~P-LE 2 and COMPARATIVE EXAMPLE ~
In the same manner as in Example 1, the copolymerization, the preparation of a solu-tion, the treatment and the measurement of the properties were conducted except that the monomer as identified in Table 4 was used. The results are shown in Table 4.

Table 4 _ Copolymer Initial After washing composition 5 times OR/WR SR ~
Example 1 FA/POEP=80/20 6/100 ~ 6/70 3 Example 2 FA/PMEP=80/20 6/100 4 6/70 3 ~ompara- FA/M9OG=80/20 6/ 70 4 5/50 3 Example l ~Z0. ~ompara- FA/PE350=80/20 6/ 60 2 5/50 Example 2 _ _ _ Note: The SR properties were measured after the sample was left to stand for one hour.
.. In Table 4, PMEP represents 2 3 (CH2CHO)7 (C2H4O)7CH3, and PE350 represents CH2=C\'CH3)COO(C2H4O)gH.
: EXAMPLE 3 A monomer/emulsifier/water mixture comprising 32.0 g of F~, l0.0 9 of POEP, 1.5 g of polyoxyethyleneoleyl ether, 0.25 g of trimethylstearylammonium chloride, 10.0 g : 35 of ethyl acetate and 121.3 9 of deionized water, was emulsified by a high pressure homogenizer. Then, 50 9 of the emulsion thus obtained, 0.24 9 of azobisisobutyronitrile and 0.12 9 of tert-dodecylmercaptan 1 32~732 were charged into a 100 ml glass ampoule. The gas phase was replaced by nitrogen, and the mixture was copolymerized at 60C for 12 hours. The emulsion thereby obtained was diluted with deionized water to obtain a treating bath having a solid con-tent of 1.0~ by weight. A
polyes-ter cloth was dipped therein, then squeezed by an angle to a pick ~p of 70% and then dried by hot air at 130C for 3 minutes and cured at 170C for one minute. The WR, OR and SR properties of the treated cloth are shown in Table 5.
EXAMPI.ES 4 to 7 and COMPARATIVE EXAMPLES 3 to 4 The copolymerization, the preparation of a treating ba-th and the treatment were conducted in the same manner as in Example 3 e~cept that the monomer composition in E~ample 3 was changed to the monomers and the amounts as identified in Table 5. The results are shown in Table 5.

Table 5 _ Copolymer Inltial After washing (wt~) 5 time OR/WR SR OR/WR SR
.. _ .
Example 3 FA/POEP=80/20 6/90 4 5/70 3 Example 4 FA/PMEP=80/20 6/90 4 5/70 3 Example 5 FA/POEP/PP800 6/90 4 5/80 3 - 4 = 70/20/10 Example 6 FA/PCPE/PP800 7 /90 4 - 3 5/80 3 - = 70/20/10 Example 7 FA/P~EP/PP800 .
~, = 70/20/10 6/90 4 5/80 3 - 4 tive FA/M9OG-80/20 6/70 3 5/50 2 Example 1 Compara- FA/M9OG/PP800 6/70 3 5/60 2 - 3-0 tive = 70/20/10 Example 2 _ ~ _ Note: The SR properties were measured after the sample was left to stand for one hour.
In Table S, PP800 represents -- fH3 CH2=C(CH3)COO(CH2CHO)13H, and PCPE represen-ts fH3 (CH2=C(CH3)COO(CH2CH2O)lo(CH2CHO)4 C16H33-n.
The water and oil repellant of the present invention has an excellent effect of providin~ the water and oil repellency and the desoilin~ properties simultaneously, 1 32~732 . and it also exhibits an effect such that after the washing operation, a high level of water and oil repellency can be obtained without heat treatment. Particularly, it provides remarkable effect such that a high level of both properties can be obtained in an aqueous dispersionsystem.

. .

Claims

1. A water and oil repellant having desoiling properties composed of a polyfluorinated group-containing copolymer obtained by copolymerizing the following monomers a and b as essential constituting components:
a: a polyfluorinated group-containing monomer b: an amphipathic monomer having a hydrophilic moiety and a lipophilic moiety.

2. The water and oil repellant according to Claim 1, wherein the weight ratio of a/b in the polyfluorinated group-containing copolymer is 65-95/5-35, and the total content of a and b in the copolymer is at least 80% by weight.

3. The water and oil repellant according to Claim 1, wherein the polyfluorinated group-containing monomer is a monomer containing a perfluoroalkyl group having from 3 to 20 carbon atoms.

4. The water and oil repellant according to Claim 1, wherein the polyfluorinated group-containing monomer is an acrylate or methacrylate containing a perfluoroalkyl group having from 3 to 20 carbon atoms.

5. The water and oil repellant according to Claim 1, wherein the amphipathic monomer is a monomer containing mixed polyoxyalkylene groups constituting the hydrophilic moiety and the lipophilic moiety.

6. The water and oil repellant according to Claim 1, wherein the amphipathic monomer is an acrylate or methacrylate having the following formula:
CH2=C(R1)CO2 [(C3H6O)m(C2H4O)n]R2 wherein R1 is H or CH3, R2 is H or a C1-C20 alkyl or aralkyl group, m ? 1, n ? 1, and 60 ? m + n ? 2.