The field of the present invention is that of silicone oil-in-water emulsions that can be used to waterproof a substrate, in particular a textile substrate, in a long-lasting manner.
Liquid silicone waterproofing compositions exist either in the form of solutions in organic solvents such as white spirit or heptane, or in the form of aqueous emulsions which have appeared more recently on the market. Conventionally, after impregnation, the organic solvent phase or the aqueous phase of these compositions volatilizes and the silicone active material remains on or in the mass of the substrate treated, so as to form a barrier against moisture.
For reasons of cost, hygiene, safety and environmental friendliness, the replacement of solvent-phase liquid silicone waterproofing compositions with aqueous silicone emulsions is sought.
For example, in the textile field, waterproofing consists in preventing water from passing through a fabric, while at the same time preserving the air-porosity of said fabric. For the waterproofing of clothing, one of the desired characteristics is permanence of the treatment. In practice, it is observed that the many current formulations do not make it possible to achieve satisfactory durabilities.
The waterproof nature of a textile support provides it with a water-repellency effect (or water-repellent property) and good water-impermeability.
Providing a textile material with all these functions is already in itself a technical feat.
Among the principal agents conventionally used for providing a textile support with a waterproof nature, the following stand out:
However, providing the textile material with long-lasting functions is an additional technical difficulty. It is known (cf. patent DE-A-2 822393) that, in order to improve anchorage, it is desirable to produce covalent chemical bonds between the support and the compound that one is seeking to deposit on the textile surface. However, given the nature and the diversity of the polymers used to manufacture textile materials, this option is not always possible and, when it is, it remains specific to a certain type of support textile material.
Obtaining textiles exhibiting the properties mentioned above, in a long-lasting manner, in particular a strong water-repellent property, may prove to be very advantageous for the textile market. In addition, it will be emphasized that, for this type of application, the persistence of the properties under conditions of wet abrasion, and most particularly when subjected to washing, is essential.
Patent application US-A-2006/0041026 describes the use of an oil-in-water emulsion comprising a polydimethyl-siloxane comprising aminoalkyl groups, an emulsifier at a content of less than 5 parts by weight and a protonating agent which is an acid and the presence of which is necessary in order to stabilize the emulsion even when it is diluted, as is taught in patent EP 556740 cited as prior art in this reference.
However, the obligatory presence of an acid in this type of formulation is prejudicial in terms of industrial manufacture, which requires the handling and storage of compounds presenting environmental and safety risks.
One of the essential objectives of the present invention is to provide a composition which makes it possible to provide a large number of porous or nonporous, absorbent or nonabsorbent substrates, and in particular textile materials, with long-lasting water-proofing.
Another objective is to provide a method for the long-lasting waterproofing of a porous or nonporous, absorbent or nonabsorbent substrate, and in particular a textile substrate. This treatment thus makes it possible to confer strong water-repellent properties on the treated substrate, in particular a textile substrate, in a long-lasting manner, and without substantially calling into question the intrinsic breathability properties when the treated material is a textile.
These objectives, among others, are achieved by virtue of the present invention, which relates to a composition, in the form of an oil-in-water emulsion, based on siloxane, constituted essentially:
In order to achieve this objective, among others, the inventors have, to their credit, entirely surprisingly and unexpectedly updated the fact that for waterproofing a substrate, in particular a textile material, in a long-lasting manner, an oil-in-water emulsion according to the invention makes it possible to do away with the addition of a protonating agent such as formic acid, acetic acid, sulfuric acid, hydrochloric acid or citric acid. This has the advantage of eliminating any environmental risk or risk in terms of safety linked to the use or storage of acid in an industrial production line.
The inventors have had to show a great deal of inventiveness, since it was necessary for them to go against the technical prejudice solidly anchored in normal practices, according to which the addition of a protonating agent is necessary from the viewpoint of the stabilization of aminosilicone emulsions and consequently from the viewpoint of the effectiveness thereof.
In the present report, the expression “textile material” denotes: on the one hand, yarns, fibers and/or filaments made of synthetic and/or natural materials which are used for the manufacture of textile articles; and, on the other hand, the textile articles themselves, comprising at least one textile surface and consisting, for example, of woven, nonwoven and/or knitted articles; by extension, the expression “textile material” also denotes materials of which the basic texture is in fibrillar form, such as, in particular, paper and leather.
The composition according to the present invention may be used directly on the substrate to be treated, in particular textile articles comprising at least one textile surface and consisting, for example, of woven, nonwoven and/or knitted articles.
The term “textile surface” is intended to mean a surface obtained by assembling yarns, fibers and/or filaments by any process, such as, for example, adhesive bonding, felting, weaving, braiding, flocking or knitting.
The yarns, fibers and/or filaments which are used for the manufacture of these textile articles can result from the conversion of a synthetic thermoplastic matrix composed of at least one thermoplastic polymer chosen from the group consisting of: polyamides, polyolefins, polyvinylidene chlorides, polyesters, polyurethanes, acrylonitriles, (meth)acrylate/butadiene/styrene copolymers, copolymers thereof and blends thereof. The thermoplastic matrix may comprise additives, such as pigments, delustrants, matifying agents, catalysts, heat and/or light stabilizers, antibacterial agents, antifungal agents and/or anti-acarid agents. It may, for example, be a matifying agent, for example chosen from particles of titanium dioxide and/or of zinc sulfide.
The yarns, fibers and/or filaments may also result from natural materials such as, in particular, cotton, flax or wool, according to conversion processes known to those skilled in the art. Of course, mixtures of synthetic and natural materials may be used.
The durability of the treatment and of the abovementioned properties is essential. The durability can be assessed in a context including the washing of the textile material. Tests carried out by the applicant under drastic washing conditions have made it possible to show the notable fastness of the treatment with the composition according to the invention, correlated with a persistence of the properties. This durability can be measured by comparing the performance levels of the treated textile material, before and after having subjected this material to an intensive washing protocol, the material being spin-dried and dried before being subjected to the property test protocol(s).
The beading effect (water-repellent property) can be measured by the spray-test method, AATC Test Method 22-1996; this method is described in the examples and may consist of a visual evaluation of the wetted appearance of the sample: the test consists in sprinkling the sample of the textile article with a given volume of water; the appearance of the sample is then evaluated visually and optionally compared with a standard; a mark is assigned according to the amount of water retained.
The measurement of the durability of the water-repellent properties makes it possible to assess the durability of the silicone treatment according to the invention. The other properties provided by the combination between the textile, these constitutive yarns, fibers or filaments, and the silicone treatment also benefit from this durability.
According to one preferred embodiment, the aminopolyorganosiloxane (A) comprises siloxyl units, which may be identical or different, of general formula (I):
R1aR2bSiO4−(a+b)/2 (I)
in which:
—R4—N(R5)(R6) (II)
—[R7—N(R8)]xR8
—[C(R8)(R8)—]y
As examples of radicals R2 that are useful according to the invention, mention may be made of the following radicals:
—CH2—NH— (C2H4O)j[C2H3(CH3)O]kH
—C3H6—NH—(C2H4O)j[C2H3(CH3)O]kH
—C3H6—NH— (C2H4—NH)i(C2H4O)j[C2H3(CH3)O]kH
—C3H6—NH—C2H4—NH— (C2H4O)j[C2H3(CH3)O]kH
The indices i, j and k are integers, which may be identical or different, between 0 and 20, the sum i+j+k preferably being between 0 and 30.
It is particularly advantageous for the R2 radical described in formula (I) above to be chosen from the group constituted of:
—(CH2)3—N(R5)2; —(CH2)3—N(R5)2— and —(CH2)3—N(R5)—(CH2)2—N(R5)2 with the symbol R5 being a hydrogen atom or a monovalent hydrocarbon-based group containing from 1 to 40 carbon atoms.
According to another preferred embodiment, the R2 radical is chosen from the group constituted of the following radicals: —(CH2)3—NH2 and —(CH2)3—NH— (CH2)2—NH2.
The nature of surfactant (B) will be readily determined by those skilled in the art, the objective being to prepare a stable emulsion. Anionic, cationic, nonionic and zwitterionic surfactants may be used alone or as a mixture.
By way of anionic surfactant, mention may be made of the following surfactants:
By way of nonionic surfactants, mention may be made of poly(alkylene oxide) alkyl or aryl ethers, polyoxy-ethylenated sorbitan hexastearate, polyoxyethylenated sorbitan oleate and cetylstearyl ethers of poly-(ethylene oxide). By way of poly(alkylene oxide) aryl ether, mention may be made of polyoxyethylenated alkyl-phenols. By way of poly(alkylene oxide) alkyl ether, mention may be made of polyethylene glycol isodecyl ether and polyethylene glycol trimethylnonyl ether containing from 3 to 15 ethylene oxide units per molecule.
By way of example of a surfactant, mention may also be made of ionic, nonionic or amphoteric fluorinated surfactants, and mixtures thereof, for example:
The term “fluorinated surfactant” is intended to mean, as is entirely known per se, a compound made up of an aliphatic perfluorocarbon-based part, comprising at least three carbon atoms, and an ionic, nonionic or amphoteric hydrophilic part. The perfluorocarbon-based part of at least three carbon atoms may represent either all, or only a fraction, of the fluorocarbon-based part of the molecule. As regards this type of compound, a large number of references are found in the literature. Those skilled in the art may refer in particular to the following references:
Mention may in particular be made of the products sold by the company DU PONT under the name Zonyl®, for example FSO, FSN-100, FS-300 and FSD, and also the fluorinated surfactants known as Forafac® distributed by the company DU PONT and the products sold under the name Fluorad® by the company 3M.
Among these surfactants, mention will in particular be made of anionic, cationic, nonionic and amphoteric perfluoroalkylated compounds, and among them, more particularly, the surfactants of the Zonyl® class sold by DU PONT, e.g.:
The following may also be specified with respect thereto:
Mention may also be made of:
As an example of polyorganosiloxane resins (C) that are useful according to the invention, mention may be made of organosilicon resins prepared by cohydrolysis and cocondensation of chlorosilanes chosen from the group constituted of those of formulae (R9)3SiCl, (R9)2Si(Cl)2, R9Si(Cl)3 and Si(Cl)4. The R9 radicals are identical or different and are chosen from linear or branched C1-C6 alkyl radicals, C2-C4 alkenyl radicals, phenyl and 3,3,3-trifluoropropyl. As alkyl radicals R9, mention may, for example, be made of methyl, ethyl, isopropyl, tert-butyl and n-hexyl radicals. These resins are branched organopolysiloxane oligomers or polymers which are well known and commercially available. They have, in their structure, at least two different siloxyl units chosen from those of formulae (R9)3SiO1/2 (unit M), (R9)2SiO2/2 (unit D), R9SiO3/2 (unit T) and SiO4/2 (unit Q), at least one of these units being a T or Q unit. The R9 radicals are distributed such that the resins comprise approximately from 0.8 to 1.8 R9 radicals per silicon atom. Furthermore, these resins are not completely condensed and they also have approximately from 0.001 to 1.5 OH and/or alkoxyl groups per silicon atom. As examples of branched organopolysiloxane oligomers or polymers, mention may be made of MQ resins, MDQ resins, TD resins and MDT resins, it being possible for the OH and/or alkoxyl groups to be borne by the M, D and/or T units, the content by weight of OH and/or alkoxyl groups being between 0.2% and 10%.
Preferably, the polyorganosiloxane resin (C) is a liquid polyorganosiloxane resin of T(OH), DT(OH), DQ(OH), DT(OH), MQ(OH), MDT(OH) or MDQ(OH) type, or mixtures thereof.
As epoxy-functionalized polyorganosiloxane (D) that is useful according to the invention, mention may be made of polyorganosiloxanes comprising at least one epoxy-functional radical Y, linked to the silicon by means of a divalent radical containing from 2 to 20 carbon atoms and capable of containing at least one heteroatom, preferably oxygen, bearing at least one epoxy unit, Y preferably being selected from the following radicals:
According to one preferred embodiment of the invention, the epoxy-functionalized polyorganosiloxane (B) is constituted of units of formula (V) and terminated with units of formula (VI) and/or constituted of units of formula (V) represented below:
in which:
According to one preferred embodiment of the invention, the organofunctional groups Y′ of the epoxy type are chosen from the following formulae:
The epoxy-functionalized polyorganosiloxane (D) may be either linear or cyclic. When it is a case of cyclic polyorganosiloxanes, the latter are constituted of units (V) which may be, for example, of the dialkylsiloxy or alkylarylsiloxy type. These cyclic polyorganosiloxanes have a viscosity of the order of 1 to 5000 mPa·s.
The obtaining of such functionalized polyorganosiloxanes is entirely within the scope of those skilled in the art of silicone chemistry.
According to another preferred embodiment, the composition according to the invention, in the form of an oil-in-water emulsion, based on siloxane, is essentially constituted:
Another subject of the invention consists of a method for the long-lasting waterproofing of a substrate, it being possible for said substrate to be porous or nonporous, absorbent or nonabsorbent, characterized in that said substrate is brought into contact with the composition in the form of an oil-in-water emulsion according to the invention as defined above.
As examples of a substrate, mention may be made of the following substrates: textiles, stones, concretes, mortars, bricks, tiles and wood.
According to one preferred embodiment, the substrate is a textile material.
According to another embodiment, the composition according to the invention is used at a content of 5% by weight of polyorganosiloxanes when the substrate is a textile material so as not to damage its properties to the touch.
The final subject of the invention consists of the use of a composition according to the invention for the long-lasting waterproofing of a porous or nonporous, absorbent or nonabsorbent substrate as defined above.
Other advantages and characteristics of the present invention will emerge on reading the following examples, given by way of illustration which is in no way limiting.
The emulsions are prepared as follows:
A part of the water and the surfactant (B) are mixed in an IKA® reactor;
Preparation of an oil-in-water emulsion (according to the protocol described in paragraph 1) of an aminosilicone oil (A)=Rhodorsil® 21648 (sold by the company Rhodia, average viscosity between 1500 and 3500 mPa·S)+7% by weight of surfactant (B) relative to the aminosilicone oil−surfactant (B)=Rhodasurf® ROX aqueous solution containing 85% of an ethoxylated fatty alcohol, sold by the company Rhodia.
This emulsion is diluted so as to obtain an emulsion containing 5% by weight of silicones.
Preparation of an oil-in-water emulsion (according to the protocol described in paragraph 1) of an aminosilicone oil (A)=Rhodorsil® 21648 (sold by the company Rhodia)+2% surfactant by weight relative to the aminosilicone oil−surfactant (B)=Rhodasurf® ROX aqueous solution containing 85% of an ethoxylated fatty alcohol, sold by the company Rhodia.
This emulsion is diluted so as to obtain an emulsion containing 5% by weight of silicones.
Preparation of an oil-in-water emulsion (according to the protocol described in paragraph 1) of an aminosilicone oil (A) Rhodorsil 21643 (sold by the company Rhodia, viscosity 300 mPa·S, nitrogen content of approximately 0.2% by weight relative to the weight of the oil)+2% surfactant by weight relative to the aminosilicone oil−surfactant (B)=Rhodasure® ROX aqueous solution containing 85% of an ethoxylated fatty alcohol, sold by the company Rhodia.
This emulsion is diluted so as to obtain an emulsion containing 5% by weight of silicones.
Calendered polyamide 6.6 fabric without treatment—90 g/m2.
A piece of fabric approximately 1 meter by 1.5 meters is cut lengthwise with scissors. The piece of fabric is folded so as to obtain squares of approximately 20×20 cm, and the fold lines are cut with a cutter.
The samples of fabrics (polyamide calendered on one face) are then treated:
The fabric is placed facing the spray, about twenty centimeters from the spray nozzle. The fabric is sprayed, beginning with the upper corner. Once the fabric has been entirely wetted, three or four sprays are added at the center of the fabric and the fabric is immediately hung at an angle on a drying screen for 24 hours before testing it, or
The fabric is folded and completely soaked in the pot containing the waterproofing agent. It is subsequently unfolded and folded again in the opposite direction, such that the inside faces in the previous folding are on the outside. The fabric is then completely resoaked. The fabric is immediately hung at an angle on a drying screen for 24 hours before testing it.
The waterproofing agents are tested after drying for 36 hours, optionally followed by a period of one hour in a tumble dryer at 60° C.
A PROLINE WMP-500C domestic machine is used to test the fabrics treated according to the procedure described in paragraph 6). Washing program No. 8 at 40° C. (delicate synthetics—40 minutes) is used. A detergent dose of 4 g/L is used (i.e., for a volume of 8 L, a dose of approximately 35 g per cycle). The detergent used is standard (nonphosphated ECE). The samples are therefore subjected to a series of machine wash cycles.
The samples are tested at ambient temperature (23° C.-RH 50%) after a drying phase after application and 4 hours after washing. The evaluation is carried out on a set of 20 cm×20 cm textile remnants. The fabric is inclined at 45° during the experiment in order to allow the water to run off. The fabric, still gripped between the rings on the corner of a table, is beaten twice.
Then, a mark is assigned according to the following criteria:
5.0=No trace of water visible to the eye.
4.8=Minuscule droplets are trapped between the fibers of the fabric.
4.5=Small droplets (approximately 5 to 10) are distributed at the surface of the fabric.
4.2=Small droplets (approximately 15 to 20) are distributed at the surface of the fabric.
4.0=Numerous droplets are visible at the surface of the fabric.
3.8=Droplets at the surface of the fabric and minuscule traces of diffusion of water in the fabric are visible.
3.5=Droplets at the surface of the fabric and traces of diffusion of water in the fabric are visible.
3.0=Drops at the surface of the fabric and the impacts of the jets of water in the fabric are visible.
2.5=Drops and a broad discontinuous diffusion of water in the fabric are visible.
2.0=Drops and a virtually continuous diffusion of water in the fabric are visible.
1.5=A light film of water at the surface and a continuous diffusion film in the fabric (surface under the jet) are visible.
1.0=A continuous film of water at the surface and in the fabric are visible under the jet. One or two droplets pass through the fabric when it is beaten.
0.5=A continuous film of water at the surface and capillary diffusion of the water throughout the fabric are visible. One or two droplets pass through the fabric when it is beaten.
0.0=A continuous film of water at the surface and capillary diffusion of the water throughout the fabric are visible. Large drops pass through the fabric when it is beaten.
The spray-test results as a function of the amount of surfactant are reported in table 1.
At a low surfactant content (invention), it is noted that the water-repellent properties are obtained from the first treatment onward and are long-lasting, whereas, with the comparative, it is necessary to wash the fabric at least once in order to give it back acceptable water-repellent properties.
Number | Date | Country | Kind |
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0605938 | Jun 2006 | FR | national |
Number | Date | Country | |
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Parent | 12308933 | US | |
Child | 12764527 | US |