US 2785145 A
Description (OCR text may contain errors)
March 1 57 T. F. COOKE ETA]. 2,785,145
SILICONATE-AMINOPLAST COMPOSITIONS AND TEXTILES COATED THEREWITH Flled July 1, 1954 mum .OUO ROLR mcF N u M/W wm ML T W A T TORNE Y.
United States atent SlLICONATE-AMINOPLAST COMPGSITIONS AND TEXTILES CDATED THEREWITH Theodore F. Cooke, Martinsviiie, Linton A. Flock,
Pluckemin, and Philip B. Roth, Somerville, N. 3., assignors to American Cyanamid Company, New York, N. Y., a corporation of Maine Application duly 1, 1954-, Serial No. 440,848
15 Claims. (Cl. 269-29.4)
This invention relates to mixtures of water-soluble salts of substituted silanetriols and water-soluble aminoplast resins and also to the treatment of fibrous materials therewith.
When textile materials are impregnated with a solution of sodium methyl siliconate or other water-soluble salts Y of substituted silanetriols a water repellent finish is obtained after prolonged drying in air. However this treatment is not commercially feasible since, few, if any, textile finishing plants operate at such low production rates or have sufiicient storage areas available for long air drying operations. When the impregnated fabric is dried rapidly by heating on conventional equipment such as tenter frames, or large drying rolls or cans, followed by the usual process Wash, the finished fabric is not water repellent. In U. S. Patent 2,507,200 it is suggested that a water repellent finish can be obtained by curing cloth impregnated with water-soluble siliconates under acidic conditions. This, of course, complicates the process.
An object of the invention is to provide an improved composition for imparting water repellent characteristics to fibrous materials.
Another object of the invention is to provide an improved process for imparting a water-repellent finish to fibrous materials.
A further object of the invention is to provide improved water repellent textile materials.
Other objects and advantages of the invention will be apparent to those skilled in the art especially upon consideration of the detailed disclosure hereinbelow.
It has been found that fibrous materials may be treated with a mixture of a water-soluble siliconate in admixture with a water-soluble amino resin followed by drying and curing the impregnated material on conventional equipment according to standard operating procedures used in 4 commercial textile finishing plants to impart a water repellent finish of a relatively permanent nature, that is, one which is durable to both prolonged laundering or repeated dry cleaning operations. N involved treatments or special curing conditions are required in the process and no reduction in the usual production rate is necessary. In addition to water repellency, the treated material has the characteristics such as shrink resistance, crease resistance, etc. which are imparted by treatment with the aminoplast alone.
The invention accordingly comprises a composition containing an aqueous solution of a water-soluble metal salt of a hydrocarbon silanetriol and a water-soluble thermo-setting aminoplast, the treatment of fibrous materials with said solutions followed by treating the heated material to dry and cure said composition to the substantially water-insoluble state and also the resulting product.
siliconates of the type contemplated in the present invention ofier many advantages over the siloxane polymers which have been used for rendering textile materials ice water repellent. The various polysiloxanes are all irisoluble in Water and the textile finisher must either apply them to cloth in the form of organic solvent solutions with the attendant fire and/or health hazards, greater cost and a larger capital outlay for solvent recovery equipment or he must employ aqueous emulsions which have to be made up with special emulsifying equipment such as colloid mills, homogeuizers, etc. in order to use the conventional water medium of the textile industry. Even then the methyl hydrogen polysiloxane which is a component of many such emulsions introduces difiiculties by reason of its tendency to evolve gaseous hydrogen which complicates packaging and storing the emulsions. No such difiiculties are encountered with the siliconates by reason of their ready solubility in even cold water. However, the siliconates pose a problem, which is not typical of the application of silicone resins to cloth, in that they do not cure on the fabric in a reasonable time at elevated temperatures.
The siliconates operative with the present invention are strong bases. They are the water-soluble hydrocarbon-substituted metal siliconates or metal salts of hydrocarbon-substituted silanetriols which may be prepared as described in Patent 2,507,200 by hydrolyzing an alkyl or aryl trichlorosilane in ice water, filtering off the precipitate and adding an equimolar amount of aqueous sodium hydroxide or another base to produce a solution of an essentially monomeric material having the probable formula:
OH R-SP-OM H in dilute aqueous solution and the following probable formula:
when dried to a solid. In this formulae, R is an alkyl, cycloalkyl or aryl radical having a suificiently small number of carbon atoms to provide substantial solubility of the compound in water; for example, R may be a methyl, ethyl, isopropyl, cyclopropyl, phenyl or like hydrocarbon radical. The preferred substituents are lower alkyl radicals and the best results appear to be obtained with sodium methyl siliconate. an atom of an alkali metal or an alkaline earth metal including sodium, potassium, lithium, barium, calcium and strontium. in the case of the latter three polyvalent metals, two of the siliconate radicals are bonded to the metal atom. While it is contemplated that other metal ions may be present by the addition of soluble salts such as lead, zinc, silver and copper to the siliconate of a strong base with probable formation of complex metalosiliconates, it does not appear that any advantages areobtained by this addition. Although the presence of copper ions may produce resistance to mildew and other fungi, aminoplasts of the type described below produce fungicidal properties in fibrous materials and it does not seem that anything is gained by the further addition of a copper salt. Moreover, salts of these other metals may impair the solubility of the siliconate of a strong base.
A broad variety of heat-reactive, water-soluble resinforming aminoplasts may be employed in the present invention. These include the various polymethylol melamines, particularly diand trimethylol melamines, monoand dimethylol ureas, lower alkyl others of'the aforesaid melamine and urea compounds (for example, methylated methylol melamines and methylated'methylol ureas) monoand dimethylol ethylene urea and mixtures M represents are greatly preferred, and especially the ethers thereof,
for outstanding results have been obtained with the methylated methylol melamine mixture which approximates the dimethyl ether of trimethylol melamine. These and the other resins listed above are prepared by methods known to those skilled in the art and which accordingly need not be set forth here.
In order to accelerate the curing of the resin-forming mixture to a degree feasible for use in commercial finishing plants, a conventional curing agent for thermosetting amino resins should be present when the impregnated fabric is cured. The catalyst or accelerator is desirably added to the treating bath in order to simplify operations and this agent should be of a type which is compatible with any ingredient, in the alkaline treating bath. Among the many such catalysts are ammonium sulfate, diammonium hydrogen phosphate, triethanolamine hydrochloride, ammonium chloride and acid salts of amines such as the hydrochloride salts of Z-methyl, Z-amino propanol-l or mixed isopropanolamines. The optimum quantity of accelerator will, of course, vary somewhat with the substance selected but, in general, about 1 to about 30 percent of catalyst, based on the total weight of the amino resin solids in the impregnating bath should be used and the preferred range is from about 3 to about 20 percent.
If desired a wide variety of textile treating additives may be incorporated in pad baths prepared according to the present invention. For example, softening agents may be added to produce a softer hand or feel in the finished material. It is not thought that this will often be necessary because the hand of the finished material can also be determined by the choice of an aminoplast resin from the broad variety indicated above and by regulating the pick-up of amino resin on the textile fabric. Odor preventatives may be mixed into the present compositions as exemplified by small amounts of urea or dicyandiamide which function to take up any formaldehyde released in the pad bath or in the curing operation.
Where a softer texture of the treated material is desired salts of diorganosilanediols and a strong base such as those disclosed above in connection with the siliconate component may also be added to the aqueous solution. These may be prepared in the manner disclosed in U. S. Patent 2,507,200. Quantities of these siliconate modifiers may range in relative molar proportions between about 1 and about 9 mols of the siliconate per mol of soluble siliconate. Of the modifiers, sodium dimethyl siliconate is preferred.
While well adapted to the treatment of cotton fabrics, the treatment described herein is applicable to any woven, knitted or felted textile material. This includes fabrics made up in whole or in part of the fibers of cotton, viscose rayon, cuprammonium rayon, cellulose acetate, wool, silk, flax, nylon of both the adipamide and caprolactam types, homoand copolymers of acrylonitrile, polyesters such as polyethyleneglycol terephthalate, and so forth.
In the accompanying drawing the figure represents in plan view a textile fabric impregnated with the heatcured reaction product of one of the aforesaid siliconates and an aminoplast of the type described hereinabove.
In treating textile materials, a pad bath is the most convenient means of uniformly impregnating a textile add-on.
material. However, sprays and other suitable means of applying the solution are also contemplated. Considerable latitude may be exercised in selecting the particular concentration of solids in the pad bath. For most pur poses a bath containing between about 2 and about 40 percent of solids is recommended. The adjustment of the squeeze rolls is correlated with the pad bath concentration in the usual manner to provide the desired With the novel compositions these factors should be adjusted to provide an add-on or impregnation of the textile material of at least 2 percent of the soluble siliconate and aminoplast based on the weight of the dry fibrous material. The optimum pick-up of amino resin and siliconate is between 5 and 15 percent of the untreated fabric Weight. While it is contemplated that larger quantities may be employed, little or nothing appears to be gained by depositing more than 40 percent on the cloth.
It is not known with certainty whether the new agents penetrate into the interior of individual fibers or remain on their surface. Accordingly, the expressions bearing and impregnated are used herein to include either deposits of the agent in the interior of the fibers or on the surface of the fibers or both.
The treated fabric may be dried and cured in two separate operations. In this case the material is dried in equipment operating at a temperature of at least 180 F. However, it is usually preferable to dry and cure in a single operation in order to simplify the process curing alone or combined. The drying and curing is performed in equipment operating at temperatures ranging between 180 F. and the point at which deterioration of the fibrous materials begins. In general, this operation may be conducted at temperatures between about 200 and about 500 F. for a period ranging between about 10 seconds and 30 minutes with the time of cure decreasing as the temperature is increased. For. most fibrous materials the optimum drying and curing is obtained by exposure to temperatures between 250 and 400 F. for a period between 30 seconds and 15 minutes.
For a better understandingof the nature and objects of this invention, reference should be had to the accompanying examples in which all proportions are set forth in terms of weight unless otherwise indicated.
Example 1' Bleached, unmercerized cotton poplin having an x 80 count is padded through an aqueous solution containing 4.4% of sodium methyl siliconate with the squeeze rolls adjusted for a wet pick-up of of the fabric weight. The impregnated-material is then dried at 225 F. One sample of the treated percale is exposed to a temperature of 350 F. for 5 minutes while another sample is similarly heated for 15 minutes. Both samples are then subjected to a conventional process wash in an aqueous solution of 0.1% soap and 0.1% sodium carbonate. Then three swatches of cloth are cut from each sample. One of these swatches is subjected to three dry cleaning operations in Varsol No. 2 solvent for 20 minutes in a tumbling jar rotating at 55 R. P. M. Another swatch is subjected to a Sanforize Wash according to the Standard Test Method 14-52 (page 132). of the 1952 Technical Manual and Year Book of the American Association of Technical Chemists and Colorists;
Upon making Water repellency determinations, the samples of treated fabric show no improvement in water repellency over the untreated cotton cloth initially after curing for both 5 and 15 minutes at the stated temperature and also after being subjected to the aforesaid washing and dry cleaning operations. It is accordingly apparent that the treatment of fabrics with sodium methyl siliconate is ineffective in producing any improvement in Water repellency whenaccelerated drying is employed.
sodium methyl siliconate solution containing 16.5 percent :0.5 percent total base titrated as NazO and 35.5 percent percent total silicone calculated as CH3SiO1.5.
Example 2 The procedure of Example 1 is repeated using an aque ous pad bath containing 3.9% by weight sodium methyl siliconate, methylated trimethylcl melamine in essentially monomeric form, 1% triethanolamine hydrochloride as a catalyst for the melamine resin and 0.5% urea as an odor preventive. After drying at 225 F. the treated 80 x 80 cotton percale is divided into samples which are cured at 350 F. for 5 and minutes respectively and then subjected to the same process wash. Both samples display good water repellency and spot resistance. In addition, excellent shrink resistance and crease resistance, as well as a good hand are observed. A swatch from each sample is subjected to a Sanforize wash. In addition another swatch of each sample is subjected to three successive dry cleaning operations in Varsol solvent. It is found that both dry-cleaned swatches and both washed swatches have the same spray ratings as before the dry cleaning and laundering operations and that the other desirable qualities of the treated material are substantially fully retained.
Example 3 Example 1 is again substantially duplicated using an aqueous pad bath containing 3.9% by weight sodium methyl siliconate, 15% of an essentially monomeric con densate of urea and formaldehyde in a-1:1.33 molar ratio, and 1% triethanolam'ine hydrochloride as a catalyst.- After drying at 225 F. the treated 80 x 80 cotton percale is divided into samples which are cured at 350 F. for 5 and 15 minutes respectively and then subjected to the same process wash. Both samples display good water repellency and spot resistance. In addition, excellent shrink resistance and crease resistance, as well as a good hand are observed. A swatch from each sample is subjected to a Sanforize wash. In addition another swatch of each sample is subjected to three successive dry cleaning operations in Varsol solvent. It is found that both dry-cleaned swatches and both washed swatches have the same spray ratings as before the dry cleaning and laundering operations and that the other desirable qualities of the treated material are substantially fully retained.
The above examples are included to illustrate the invention and it is to be understood that the present invention is not limited thereto since various modifications and alterations may be made without departing from the scope of this invention.
1. A composition of matter which comprises an aqueous solution of a water-soluble metal salt of a hydrocarbon silanetriol and a water-soluble thermosetting aminoplast of the group consisting of formaldehyde con densates of melamine, urea, ethyleneurea, succinamide, adipamide, alkyl ethers of said condensates and polymers thereof.
2. A composition of matter which comprises an aqueous solution of a water-soluble metal salt of a hydrocarbon silanetriol, a water-soluble thermosetting mind plast of the group consisting of formaldehyde condensates of melamine, urea, ethyleneurea, succinamide, adipamide, alkyl ethers of said condensates and polymers thereof and a curing catalyst for the aminoplast.
3. A composition of matter which comprises an aqueous solution of a water-soluble alkali metal lower alkyl siliconate, a water-soluble melamine-formaldehyde condensate and a curing catalyst for the melamine-formaldehyde condensate.
4. A composition according to claim 3 in which the melamine-formaldehyde condensate comprises methylated trirnethylol melamine.
5. A composition of matter which comprises an aqueous solution of parts by weight of sodium methyl siliconate, between about 25 and about 1000 parts of methylated trimethylol melamine and a sufficient quantity of a curing catalyst to cure the methylated trimethylol melamine to the water-insoluble state.
6. A process which comprises contacting a textile material with a composition according to claim 1 and heating the treated material to dry and cure said composition to the substantially water-insoluble'state, whereby a durable water-repellent finish is imparted to the textile material.
7. A process which comprises contacting a textile material with a composition according to claim 2 and heating the treated material to dry and cure said composition to the substantially water-insoluble state, whereby a durable water-repellent finish is imparted to the textile material.
8. A process which comprises contacting a textile material with a composition according to claim 3 and heating the treated material to dry and cure said composition to the substantially water-insoluble state, whereby a durable water-re ellent finish is imparted to the textile material.
9. A process which contacting a textile material with a composition according to claim 4 and heating the treated m terial to dry and cure said composition to the substantially water-insoluble state, whereby a durable water-repellent finish is imparted to the textile material.
10. A process which comprises contacting a textile material with a composition according to claim 5 in sufiicient quantity to deposit a total of at least 2 percent of said siliconate and melamine resin thereon based on the weight of the dry textile material and heating the treated material to a temperature of at least degrees Fahrenheit for a period sufiicient to dry and cure said composition to the substantially water-insoluble state, whereby a durable water-repellent finish is imparted to the textile material.
11. An article which comprises a textile material impregnated with the heat-cured reaction product of a composition according to claim 1.
12. An article which comprises a textile material impregnated with the heat-cured reaction product of a composition according to claim 2.
13. An article which comprises a textile material impregnated with the heat-cured reaction product of a composition according to claim 3.
14. An article which comprises a textile material impregnated with the heat-cured reaction product of a composition according to claim 4.
15. A textile article having a durable water-repellent finish which comprises a textile material impregnated with at least 2 percent by weight of the heat-cured reaction product of a composition according to claim 5.
" n HA" References titted in the file of this patent UNlTED STATES PATENTS 2,500,842 MacKenZie Mar. 14, 1950 2,507,200 Elliott May 9, 1950 2,571,029 Goodwin Oct. 9, 1951 2,612,482 Rasmussen Sept. 30, 1952 2,634,285 Rust Apr. 7, 1953