Novel Silanol Waxes

1. Field of the Invention

The present invention relates to a series of novel silanol fatty esters which provide outstanding lubrication, and hydrophobicity to a variety of substrates. The compounds of the invention are waxy solids which melt under pressure to give a clear liquid lubricating oil. The esterification by which the compounds are prepared is the reaction of a silanol, a hydroxy containing silicone polymer, and a fatty acid or polycarboxylic acids.

2. Arts and Practices

Silicone compounds have been known to be active at the surface of plastic, cellulosic and synthetic fibers as well as paper. They are good nondurable lubricants and are very stable to oxidation, however, their high cost and lack of efficiency at low concentrations as well as low durability have made their acceptance in commercial products quite low. In all instances, commercially available quats are the active ingredient in traditional laundry care markets, with little or no silicone added.

The low efficiency and low durability of polydimethylsiloxane is due to the fact that it is very water insoluble and deposits on the surface to obtain a minimum free energy in the solution. Simply, the silicone oil delivery to the surface by hydrophobic binding, not chemical bonding. At the surface, the polydimethylsiloxane is a very effective fiber lubricant, however, there are two drawbacks, first; the polydimethylsiloxane is not chemically bonded so the effect is very transient and disappears with one washing, and second; since there is no reaction of the siloxane to the surface an equilibrium between fiber absorbed polydimethylsiloxane and polydimethylsiloxane in the dispersion results in very inefficient percentage of silicone deposited. A large amount of the expensive silicone goes down the drain with the waste water.

In many applications, there is a desire for a solid wax which can spread on surfaces. These applications include personal care products like antiperspirants and skin creams. Unfortunately, most silicone derivatives are liquid to very low temperatures. Attempts to overcome this deficiency have been made by reacting stearyl alcohol with a chloro silane to obtain the following product; ##STR1##

The difficulty with the use of this material is that a large excess (50% by weight) of the alcohol needs to be added to get a product which is free of the irritating chlorosilane raw material. When such an excess is used the product behaves functionally more like the stearyl alcohol than like a silicone compound. Additionally, the compound is not polymeric, hence the superior lubrication and hydrophobicity enhancements which can be achieved by dimethylpolysiloxane is not obtainable with these compounds.

Many attempts have been made to overcome these problems and get a truly lubricious silicone wax.

U.S. Pat. No. 3,511,699 to Sterman issued May 12, 1970 teaches that epoxy compounds placed in the silicone backbone by hydrosilation can be cured onto certain fibers to give improved substantivity. The substantivity is based upon the reaction of hydroxyl groups on the cellulosic and the epoxy group in the silicone polymer. The resulting bond is a ether linkage and a new hydroxyl group. While a definite improvement over other compounds the efficiency and durability of the were not good enough to allow for cost effective incorporation of these materials in detergent formulations.

It is the object of the present invention to provide novel silanol fatty ester compounds which are solid at ambient temperatures but melt and become substantive to the surface of a fibrous, plastic or cellulosic material. These materials render in lubricity, and hydrophobicity.

It is another objective of the current invention to provide silanol esters which can be used in textile, and personal care applications to render softness and lubrication to the substrates being treated. The superior antistatic properties are an important benefit, since this is a major aspect of consumer perception of softness in consumer and industrial laundry applications. Lubrication has been a property which is purported to effect garment life. Application of the compounds of the invention can be from solvent, aqueous dispersion or solution, or applied neat in these processes. The compounds of the current invention make outstanding napping lubricants were a waxy material which liquefies under application of pressure is desirable.

The present invention relates to novel silanol fatty ester compounds. The compounds by virtue of the silanol ester group form effective surface modifying finishes. The compounds of the present invention are substantive to cellulosic and synthetic fibers as well as metal surfaces and plastic polymers.

The compounds of this invention are silanol esters made by the esterification of a fatty acid and/or polycarboxylic acid, ester or anhydride with a silanol compound. The compounds of the present invention conform to the following structure; ##STR2## R.sup.2 is ##STR3## R.sup.1 is alkyl having 6 to 30 carbon atoms; R.sup.3 is selected from --(CH.sub.2).sub.c --, or --(CH.sub.2).sub.d --CH.dbd.CH--(CH.sub.2).sub.e --;

a is an integer from 0 to 20;

b is an integer from 1 to 200;

c, d and e are independently integers from 1 to 10;

R.sup.4 is alkyl having from 1 to 18 carbon units or aryl (C6H5).

The compounds of the present invention are prepared by the reaction of a silanol compound and a fatty acid or polyacid. Examples of suitable reactants are as follows;

Silanol compounds are well known and are marketed in the trade under many names. The compounds conform to the following generic structure; ##STR4##

Compounds of the following structure are available from Siltech Inc. Norcross Ga. and are marketed under the Silteh S series tradename shown;

The esterification can be run without catalyst; however, when no catalysts used reaction rates are less efficient. Standard esterification catalysts are generally used at concentrations of between 0.05% to 0.50% with a preferred range of 0.1% to 0.3%. Catalysts which are effective include but are not limited to; sulfuric acid, p-toluene sulfonic acid, methane sulfonic acid, tin metal, zinc metal, titanium metal, organo titianates, organo tin compounds, organo zinc compounds, zinc oxide, magnesium oxide, calcium oxide, etc.. The most preferred catalyst is stannous oxylate. The reaction is conducted at between 140.degree. and 240.degree. C. under an inert nitrogen blanket. The nitrogen blanket preserves the color. Preferred temperature range is between 180.degree. and 210.degree. C. Water is removed from the reaction which is done using a nitrogen sparge or vacuum.

The reaction can be run with either a stiochiometric amount of the fatty acid. However, it is recommended that an excess of about 1 to 5% of one acid be employed.

Into a suitable round bottom, three neck flask equipped with a Dean Stark trap, a thermometer and a nitrogen sparge is added 284.0 grams of stearic acid, 0.25% by weight of the total batch charged of stannous oxylate and 5,000 grams of Siltech S 710. The reaction mass is blanketed with nitrogen, and heated to 180.degree. and 200.degree. C. under an inert nitrogen blanket. Once the reaction temperature reaches 120.degree. C. water begins to boil off and is collected in the Dean Stark Trap. Within four to five hours the theoretical water is collected off and the acid value is very low. The product is a white wax and is used without additional purification.

Example 1 is repeated only this time substituting the specified number of grams of the fatty acid specified for the stearic acid and the specified type and number of grams of silanol compound as shown below:

Into a suitable round bottom, three neck flask equipped with a Dean Stark trap, a thermometer and a nitrogen sparge is added 254.0 grams of lauric acid, 7.3 grams of adipic acid, 0.25% of total weight of the batch of stannous oxylate and 500 grams of Siltech S 701. The reaction mass is blanketed with nitrogen, and heated to 180.degree. and 200.degree. C. under an inert nitrogen blanket. Once the reaction temperature reaches 120.degree. C. water begins to boil off and is collected in the Dean Stark Trap. Within four to five hours the theoretical water is collected off and the acid value is very low. The product is a white wax and is used without additional purification.

Example 13 is repeated only this time substituting the specified number of grams of the fatty acid specified for the lauric acid and the specified type and number of grams of diacid and the specified type and number of grams of silanol compound as shown below;

Compounds of this invention were compared to standard compounds commercially available using AATCC Test Method 117-1979. The color fastness heat test uses a 400 F. (205 F.) hot iron which is applied for 60 and 180 seconds. The color is rated on a 1-5 basis for yellowness, (5 being the most yellow).

As can be seen the compounds of the present invention are non-yellowing softeners when compared to standard softeners.

As can be easily seen the compounds of the present invention are excellent lubricants.

A laboratory test is conducted to screen the wet comb properties of a representative member of the family of novel compounds. Hair swatches are purchased from a supply of human hair from the same head. Each test swatch contains 7 grams of hair and is 11 inches in length. The hair is tied tightly 1 inch from one end with string. The swatch is pre-cleaned with a 3% solution of ammonium lauryl sulfate. Subsequently, the swatch is washed under running tap water. The hair is then squeezed out and while still damp dipped into a 200 ml solution of 0.2% active quaternary. Another rinse is made, then the swatch is blotted dry. The swatch is then treated by holding the hair swatch, combing the hair as rapidly as possible while alternating the side of the swatch combed. The time needed to get one smooth free stroke without tangling is recorded. Typical results for the standard quaternary compounds used in hair conditioning (stearyldimethylbenzyl ammonium chloride) range from 12-14 seconds.

As can be seen, the compounds of the invention give significant conditioning properties to hair makes them prime candidates for cosmetic as well as textile and other related applications. The following examples are typical formulations which utilize the compounds of the present invention;

The compounds of the invention can be utilized to formulate deodorant sticks and related products. The silanol ester wax of this invention are less volatile than the cyclic silicones commonly used and can be used to replace stearyl alcohol in many formulations. Superior feel and lubrication are achieved. A typical formulation is;

The compounds of the invention can be utilized to formulate rouge and related products. A typical formulation is;

The compounds of the invention can be utilized to formulate eyeshadow products. A typical formulation is;

The compounds of this invention make outstanding bases for the preparation of lipstick products. The lipsticks made with these materials have outstanding slip and provide lubrication and emmoliency properties to the stick. A typical formulation is;

By replacing the C-20 guerbet alcohol with a guerbet citrate ester and altering the ratio of components a lipcream can be formulated;

The compounds of the present invention can be incorporated into drier sheet softener formulations to improve fiber to metal lubrication (antistat), fiber to fiber lubrication (hand and softness) without adversely effecting the melting point of the sheet. Traditional silicone compounds have not been widely used in these applications because of their liquidity, which alters the melting point properties of the sheet.

The compounds of the present invention can be incorporated into wax formulations for furniture and automotive applications. Their high lubrication properties as well as their being solid at ambient temperatures makes them excellent wax bases. The property of liquification under pressure also contributes to the functionality.

The compounds of the invention can be added to powdered detergents to obtain a detergent/softener/antistat package in one compound.