Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
1999-08-12
2002-04-23
Sergent, Rabon (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C008S115640, C008S115670, C008S192000, C428S374000, C428S375000, C428S378000, C428S423100, C524S197000, C524S198000, C524S200000, C524S507000, C524S544000, C524S589000, C524S591000, C524S805000, C524S839000, C524S728000, C526S242000, C526S301000, C526S312000, C528S045000, C528S070000, C525S124000
Reexamination Certificate
active
06376592
ABSTRACT:
The present invention relates to a water dispersion type water and oil repellent composition which provides soft handling during treatment and which is capable of imparting practical water and oil repellency excellent in durability against washing, dry cleaning and abrasion.
Heretofore, a technique has been known to treat e.g. a fiber product with a polymer comprising, as constituting units, a polymerizable monomer having a polyfluoroalkyl group (hereinafter referred to as a R
f
group) or a compound having a R
f
group in the form of an organic solvent solution or an aqueous solvent dispersion to impart water and oil repellency to its surface.
In order to improve durability of water and oil repellency against washing or dry cleaning, it has been attempted to copolymerize a polymerizable monomer having a R
f
group with a polymerizable monomer having a bonding group, to blend a polymer having a R
f
group with a polymer having a high coating film strength, or to change the polymerization method.
Further, it is also known to improve the durability by adding a separate water-soluble or water-dispersible crosslinking agent (such as a melamine resin or a blocked urethane resin) during treatment of the fiber with a polymer dispersion, to increase the adhesion between the fiber and the polymer, and it has been confirmed that such a method is effective for improvement of the durability. However, by this method, it is required to add a large amount of a crosslinking agent in order to obtain adequate durability, and in such a case, there has been a problem that hand tends to be hard.
With conventional water and oil repellent compositions and water and oil repellent treatments, the durability against washing or dry cleaning, of the water and oil repellency imparted to common clothings, has been generally satisfactory. However, for clothings such as sports wears or mountaineering wears for which still higher water and oil repellency is required, the practical durability functions, i.e. durability against washing or dry cleaning, durability against abrasion and durability against hydrostatic head, of the water and oil repellency, have been inadequate.
Especially when polyamide fibers having a relatively high hydrophilicity, very fine synthetic fibers with a fiber diameter of at most 10 &mgr;m or fibers having a special surface shape such as modified cross-section yarns or new synthetic fibers (split yarns), are treated for water and oil repellency, the water and oil repellency or the hydrostatic head tend to remarkably decrease by a few times of washing and dry cleaning or by abrasion during wearing, such being practically problematic. Further, a large amount of crosslinking agent has been required to be added later, such being unsatisfactory also from the viewpoint of hand.
Accordingly, it has been desired to develop a water and oil repellent composition having adequate durability without requiring any crosslinking agent or with an addition of a crosslinking agent in such a small amount as not to impair the hand.
The present inventors have conducted a detailed study on the mechanism of development of durability of the water and oil repellency and the hydrostatic head imparted to a fiber product and a method for reinforcing the water and oil repellency. As a result, it has been found that the durability of water and oil repellency can be remarkably improved, and the above problems can be solved, by treating the fiber product with an aqueous medium dispersion having a certain specific composition prepared by a certain specific method.
The present invention provides a water dispersion type water and oil repellent composition obtained by polymerizing the following polymerizable monomer mixture (b) in the presence of a compound (a) having a blocked isocyanate group and no polymerizable unsaturated group:
(b) a mixture comprising a polymerizable monomer having a polyfluoroalkyl group and a polymerizable monomer having no polyfluoroalkyl group.
The mechanism of how the water and oil repellency excellent in the durability is imparted to an object treated with the water dispersion type water and oil repellent composition of the present invention is not clearly understood. However, it is considered that the compound (a) and a polymer formed from the polymerizable monomer mixture (b) will form composite particles, whereby as compared with a case where the polymer is subsequently added to the compound (a), self crosslinking of the compound (a) uniformly present even in the interior of the particles, crosslinking with the polymer formed from the polymerizable monomer mixture (b) and crosslinking with fibers, will proceed uniformly, and a firm coating film can readily be formed on the surface of the treated object.
The compound (a) is a compound having a blocked isocyanate group and no polymerizable unsaturated group, which is one having an isocyanate group moiety of an isocyanate group-containing compound blocked with a blocking agent.
Such an isocyanate group-containing compound may, for example, be tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene-1,5-diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, 4,4-dicyclohexylmethane diisocyanate, norbornane diisocyanate, isophorone diisocyanate, an adduct, an allophanate modified product, a biuret modified product, an isocyanurate modified product or a carbodiimide modified product of the foregoing compounds, or a urethane prepolymer.
The blocking agent may, for example, be an oxime such as acetone oxime or methyl ethyl. ketoxime, an alcohol such as 2-ethylhexanol, 2-methoxy-1-propanol or 3-methyl-2-penten-4-yne-1-ol, a phenol such as phenol or 2,4-dimethylphenol, a lactam such as &egr;-caprolactam or pyrrolidinone, an N-hydroxyphthalimide such as N-hydroxysuccinimide or N-hydroxyphthalimide, imidazole, or ethyl acetoacetate.
The compound (a) is preferably a non-yellowing type isocyanate such as hexamethylene diisocyanate or isophorone diisocyanate, or its modified product such as oxime or lactam blocked product. Specifically, it may, for example, be a methyl ketoxime blocked product as an isocyanurate modified product of hexamethylene diisocyanate or isophorone diisocyanate “Takenate (WB-70, WB-920 or XWB-72-Z-56), tradename, manufactured by Takeda Chemical Industries, Ltd.”, “Elastron (BN-08 or BN-11), tradename, manufactured by Daiichi Kogyo Seiyaku K.K.”.
The polymerizable monomer mixture (b) comprises a polymerizable monomer having a R
f
group (hereinafter referred to also as “a R
f
group-containing monomer”) and a polymerizable monomer having no R
f
group (hereinafter referred to also as a R
f
group-non-containing monomer), as essential components.
The R
f
group-containing monomer has a R
f
group and a polymerizable unsaturated group.
The R
f
group is a group having at least two hydrogen atoms of an alkyl group substituted by fluorine atoms. The carbon number of the R
f
group is preferably from 4 to 20, more preferably from 6 to 16, most preferably from 9 to 12. The R
f
group may have a straight chain structure or a branched chain structure. In the case of a branched chain structure, it is preferred that the branched moiety is present in the vicinity of the terminal end of the R
f
group, and the branched moiety is a short chain having from 1 to 4 carbon atoms. Further, the R
f
group may have an etheric oxygen atom between carbons of a carbon-carbon bond. The R
f
group may contain a halogen atom other than a fluorine atom, and the halogen atom other than the fluorine atom is preferably a chlorine atom.
The number of the fluorine atoms in the R
f
group is at least 60%, particularly preferably at least 80%, when it is represented by the formula of [(number of fluorine atoms in the R
f
group)/(number of hydrogen atoms contained in an alkyl group having the same carbon number as in the R
f
group)]×100(%). Further, the R
f
group is preferably a group having all hydrogen atoms in an alkyl group substituted by fluorine atoms, i.e. a perfluoroalkyl group of the formula C
m
F
2m+1
—, wherein m
Maekawa Takashige
Shimada Toyomichi
Asahi Glass Company Ltd.
Sergent Rabon
LandOfFree
Water dispersion type water and oil repellent composition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Water dispersion type water and oil repellent composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Water dispersion type water and oil repellent composition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2855588