Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2002-12-13
2004-04-06
Wu, David W. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S242000, C524S529000, C524S543000
Reexamination Certificate
active
06716944
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a water and oil repellent composition which can impart water and oil repellency and an antifouling property to an object.
BACKGROUND ART
Heretofore, techniques of coating an object with a hydrophobic solid material having a small surface tension to modify the surface of the object, have been known. For example, there is a technique of treating an object with a low molecular weight hydrocarbon compound, such as a hydrophobic wax, a carbonic acid having at least one long-chain alkyl group in its molecule, an amine or a thiol, an acrylate type or vinyl type high molecular weight compound, or a silicone. However, such a hydrocarbon type low molecular weight compound or a silicone had a disadvantage that it can not impart oil repellency, although it can impart water repellency to an object.
On the other hand, as a technique for imparting water repellency and oil repellency at the same time, it has been common to treat an object with an organic solvent solution or an aqueous dispersion of a polymer containing polymerized units of a polymerizable monomer containing a polyfluoroalkyl group (hereinafter, a polyfluoroalkyl group will be referred to as an R
f
group) in its molecule or a copolymer of such a polymerizable monomer with other monomers (hereinafter such polymer and copolymer will be commonly referred to also as an R
f
group-containing polymer), or a low molecular weight compound having an R
f
group.
The development of such water and oil repellency is caused by formation of “a surface having a low surface energy” where the critical surface tension is low, which is formed on the surface of the coating film by a surface orientation of R
f
groups. It has been considered that in order to develop both water repellency and oil repellency, the orientation of R
f
groups on the surface is important, and, in order to realize the surface orientation of R
f
groups, it is necessary that the melting point of fine crystals in the polymer, derived from R
f
groups, exists. For this purpose, an R
f
group-containing monomer (crystalline R
f
group-containing monomer) having a melting point of fine crystals derived from R
f
groups, has been used.
This crystalline R
f
group-containing monomer achieves the purpose with a view to developing the water and oil repellency, and improvements have been made in other practical functions. For example, an improvement has been made such that in order to improve the durability against e.g. washing, dry cleaning and abrasion, a monomer for providing high hardness or a monomer having a crosslinking reactive group is employed in addition to the crystalline R
f
group-containing monomer, or the copolymer obtained is blended with a polymer having high coating film strength.
On the other hand, with respect to a copolymer (crystalline polymer) containing polymerized units of a crystalline R
f
group-containing monomer, an investigation has been made to soften the hard hand, or to lower the melting point of R
f
groups in order to develop the water repellency under the low temperature curing condition. For example, a case is known wherein a monomer containing a perfluoroalkyl group (hereinafter, a perfluoroalkyl group will be referred to as an R
F
group) having a wide range of chain length, is copolymerized with an alkyl group-containing monomer. Further, in the same manner, a method is known which uses a silicone containing an R
F
group having a wide range of chain length.
For example, JP-A-7-173025 (cosmetic composition containing a fluorine type compound and a wax having a specific melting point), JP-A-10-237133 (tetrapolymer comprising R
F
group (meth)acrylate, stearyl (meth)acrylate and other two types of monomers as essential components), JP-A-10-81873 (mixture of a fluorine type water and oil repellent, and an alcohol having an R
F
group having a specific chain length or a perfluoropolyether group-containing alcohol) and JP-A-8-109580 (reacted product of an amino group-containing silicone and an R
f
group-containing ester compound) may be mentioned as known art.
Meanwhile, as an example of limiting the chain length of an R
f
group-containing monomer to be used, JP-A-62-179517 (acryl type heptapolymer wherein the chain length distribution of R
f
groups is defined) may, for example, be mentioned, but it contains at least 40% of crystalline R
f
group-containing monomers.
Further, there has been a problem that on a surface treated with a water and oil repellent having a crystalline polymer as an active component, the bonding property and the hand are not satisfied at the same time. Namely, even when bonding treatment is attempted to impart various functions on the surface of fiber products treated with a water and oil repellent containing a crystalline polymer, for example, even when it is attempted to bond a film laminate or a seam tape to impart a water proofing property, or even when it is attempted to bond a urethane or acrylic resin to impart moisture permeability and water proofing property, it has been difficult to secure a sufficient bonding property since the crystalline Rf groups impair the bonding property. It has been tried to improve the bonding property by using a copolymer of a crystalline R
f
group-containing monomer and a specific monomer such as vinyl chloride. However, this method tends to further harden the hand of fibers, and thus, the bonding property and the hand have not been satisfied at the same time.
In the techniques of this field represented by these known art references, the physical properties are improved from a viewpoint of functions required in addition to the water and oil repellency, without impairing the water repellency and oil repellency attributable to R
f
groups. However, since the R
f
group-containing crystal polymer is used as the main component, the following demerits resulting therefrom have not been fundamentally overcome.
In conventional water and oil repellents, in order to achieve both of imparting of the water and oil repellency and imparting of the durability, it has been considered essential to use a crystalline R
f
group-containing monomer wherein the melting point derived from fine crystals of R
f
groups, is high (usually at least 70° C.), among crystalline R
f
group-containing monomers.
However, if the crystalline R
f
group-containing monomer is used, the entire polymer will have high crystallinity derived therefrom, and accordingly, an object coated or treated with such a polymer becomes very hard. For example, in the case of e.g. fiber products which should naturally be flexible, their flexible hand may be impaired, or since the coating film is hard and brittle, a defect such as a hand mark or a chalk mark formed during handling of the object, tends to remain on the whole cloth as the final product.
Further, there has been a demerit that a high water and oil repellency may be developed in the initial stage after the treatment, such performance tends to be extremely deteriorated by abrasion during the usage or by repeated washing. Namely, a water and oil repellent which can maintain the initial performance stably, has been desired. Further, on the coating film, shortage in the bonding property of the surface, or cracks or fractures which deteriorate the quality of the object tend to result, and therefore, it has been desired to overcome such problems so that this type of water and oil repellent can be applied to a wider range of materials.
Further, when a crystalline polymer is used as the main component, in order to obtain a uniform coating film having high water and oil repellency, usually, a process has been essential wherein after the coating, a high temperature treatment at a temperature higher than the melting point of fine crystals, is applied to melt the polymer, followed by cooling to form the film. However, if such a high temperature treatment is applied, there has been a case where a problem such as deterioration of color fastness, hardening of the hand or a fading, is induced and the quality of treated objects is further det
Maekawa Takashige
Seki Ryuji
Shimada Minako
Sugimoto Shuichiro
Asahi Glass Company Limited
Hu Henry S.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Wu David W.
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