CA1050705A - Rubber and polymer preservative - Google Patents

Abstract

ABSTRACT
A process for protecting, preserving, and renewing surfaces, especially rubber and other natural and synthetic polymers, leather, wood, painted surfaces and metal, employs an aqueous emulsion of an unsubstituted or substituted dimethylpolysiloxane fluid, or mixtures thereof, to thoroughly wet the surfaces to be protected. After a period of penetration, preferably about twenty four hours, the surface is rewetted and allowed to penetrate as in the first application. At least one additional application and penetration gives optimum protection. A preservative composition preferred for use in the above process is also provided. In addition to a dimethylpoly-siloxane fluid aqueous emulsion as above described, this preservative also includes, based on the weight of the polysiloxane fluid, of from about 15%
to about 65% by weight of one or more polyol compounds, preferably diethylene glycol and glycerin.

Description

-~5~7GD~i ; This in~ention relates to improvem~nts in materials for preserving, rene~ing~ and enhancing the appearance of rubber, lea~her, and polgm~r surf-` aces.
Natural and synthetic polymer surfaces a~ld particu~arly rubber frequently possess rather dull surfaces and even where the surfaces are init- -ially satisfactor~, they are often subject to the dele~erious ef~ects of ozone, ultraviolet radiation, and other environmental causes of the degrada_ tion. Besides rubbers and plastics, even leather is subject to such deter_ ioration.
While not limited thereto, a major application for the invention lies in protecting and improving the appearance of rubber parts of auto-mobiles Auto tires, rubber sealing strips, and vinyl tops are subject to deterioration with time due to their e~posure to envirorlmental stresses such as ultravi~let radiation, ozone, dirt, water and grease, Subjected to such enviror~ental stresses, the rubber molecules at the surface undergo scission.
The result is a structural change in thc rubber surface that enables mole_ cules of soil and other contaminants to adhere ~o that surface in greater degree whereby the surface becomes discolor~d, Further, scission of the rubbor molecule chains causes surface cracking, ~dditionall~, release of other constituents of the rubber body that are not chemically combined ~ith the rubber molecules but are held in place only mechanically in suspensions, a phenomenon otherwi3e called blo~, also results in discolorat~on.
The invontion provides a substance which will protect the rubber against ozone, ultraviolet and the other environment~l causes of chain scission. Additionall~, it will seal and renew surfaces that have been damaged by scission against further scission. Fur~her, it provides a hydrophobic surface of relatively high lubricity to which soils do not adhere Similarlr, preservatives made according to the invention will renew, protect and enhance the appearance of plastics, particular:Ly vinyls ~6~513~7~
and acrylics, even when these plastics are ingredients in paints. The in~ent-ion is particularly useful for protecting all types of rubbers, vinyls, and acrylics and even leath~r and wood where~er found. Furniture coverings, industrial belting~ plastic mop boards are examples of important applications and illustrate the wide range of those applications.
Materials formerly used for the preservation of rubber were based on lamp black and included materials highly corrosive to metal and painted surfaces eommonly found on automobiles. These rubber ~reatment materials were applied like paint to the rubber surfaces. The rubber treated in this manner had an unnatural "painted" appearance~ Reapplications required removal of old coatings, and ~re difficult and inconvenient. Not only w~re such materials ineffective in protecting rubber surfaces from deterioration caused by environmental stresses, but they were also quite mess~ and inconvenient to use. In addition, the corrosive and toxic ingredients were harmful to the adjacent surfaces and to the user.
By contrast, the preser~a~ive of the invention is c~mpounded of non_toxic materic~ls which are safe for the user as well as for surfaces adjacent to rubber parts on automobiles. In fact, the preservative will also protect these surfaces as well. Furthermore, the prese~vative provides a natural look to the rubber, is easy to apply, and highly cffective in protect_ ing surfaces, particularly rubber, from o~one, ultra-violet radiation, water and smog.
According to the in~ention, there is provided a process for pre_ serving a~d renewing surfaces, particularly natural and synthetic polymers, wood, leather, metal and porcelain, camprising: ~1) wetting the surface ;~
with a composition comprising an emulsion of at ~east ono water-emulsifiable organopolysi~o~ane fluid and, based on the weight o~ the organopolysiloxane f`luid, from about 65% to about 5,000% by w~ight of water; (2) cillawing said composition to pen~trate the sur~ace; and, (3) repeating s~eps 1 and 2 at l~ast one time. Preferably, at l~ast about 24 hours is allowed to elapse ~or _ ~ _ ~05~705 -- .
penetration prior to rewetting of said surface and wherein steps 1 and 2 are repeated at least two tim~s It is also preferred that the surface is lightly buffed at the end of each period of penetration prior to re~etting of said surface According to a further embodiment of the invention, the composition employed further comprises; based on the weight of the organopolysiloxane fluid, fram about 15% to about 65% by weight of at least one water-miscible polyol component such as glycerin, diethylene glycol or particularly a mixture of these ~wo polyols. In such polyol mixtures, the glycerin is preferably present in an amount of from 60% to 10% by weight based on the weight of the organopolysiloxane, on the diethylene glycol in an amount of from 0.5% to 10%.
Preferred organopolysiloxane fluids are dimethylpol~siloxane fluids having a viscoslty less than about 10,000 centistokes.
The preservative composition according to the invention comprises at least one water-emulsifiable organopol~siloxane fluid emulsified in from about 65% to about 5,000% by weight of water based on the weight of the poly-siloxane fluid. Polyols which are most preferred for inclusion in the pre_ servative composition are diethylene glycol and glycerin.

In order to preserve and renew surfaces, particularly rubber surfaces, the preservative composition of the in~ention is first used to thoroughly wet the surface. After wetting the surface, suf~icient time is then allowed for thorough penetration of the preservative into the surface layer of the materi_ al. It is believed that penetration occurs by capillary action whereby the molecu}es of the preser~ative composition, and especiilly the organopolysilox~
ane fluid, are drawn into ~he surface~- There, the mslecules can hook or wrap around the molecules of the material to be protected to physically attach themselves thereto. At least one additioncil rewetting of the surface should then be made, followed by a period of penetration. Preferably, at least three applications of the preservative to the surface to be protested should be m0d~.

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It has been found that some measurable protection against environ-, mental stresses can be imparted to rubber and other polymer surfaces using an emulsion of an organopolysiloxane fluid in water. ~hen applied to a rubber ~,~
surface, the water acts to swell the surface of the rubber and helps to aid penetration of the polysiloxane fluid into the rubber or polymer surface.
It has been further discovered that a significantly greater measure of protection can be imparted, especially to natural and synthetic polymer :.
surfaces, if at least one polyol c~mpound is added to ths emulsion of the organopolysiloxane and water. Not only is a greater degree of protection and longevity thereof provid0d by this composition, but also the appearance is greatly improved. These consituents appear not to combine chemicall~ but they do combine mechanically to form a homogenous mixture. Combination is facili_ tated by emuLsifying the silicone in water and then adding the other constit_ u~nts to that emulsion. The result achieved by treatment with the mixture is different, and better than the result that is achieved if the material is treated with the constituents individually.
The mixture work~ best when the constituents are mixed in certain proportions. Alcohol and some other soil solvent~ can be added as cleaners ; without harmful effect but pre_treatment with them achieves the same result as incorporation in ~he mixture. This is not true of water, however, The appearance of the surface after application is affected by the amount of water in the mixture This is particularly apparent in the case of rubber. The degree of appearance difference is a function of the degree of deterioration of the surface at the time of application. The resultant degree of gloss appears to be less a question of how much of the o~her ingredients are deposit_ ed on the surface than it is a function of the mechanics by which the water serves as a vehicle for deposition of the preservative materialO Thus, ~ater is an important ingredient of the mixture although, whereas the other ingred-; ients remain as part of the trea~ed surface, it appears that the only function ;~ 30 of the water is to serve as a mechanism for mechanically interrelating the ,;. . .

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other substances and facilitating their application.
The organopol~siloxane or silicone fluid in the preservative is believed to be responsible for water_proofing the rwbber and for impeding scission. Scission is promoted by the presance of czone and oxygen and the silicone is believed to help to exclude those materials The preservative of the invention requires at least one water-emu~sifiable organopolysiloxane fluid. These fluids are also referred to as silicone fluids and are distinguished from silicone elastomers and resins. -They are usually basically dimethylpol~siloxane fluids, ~hich are substant-ially linear in nature. The structure of such a dimethylsilicone fluid is shown by the following general formula where N is the number of units:

CN3 ~ CN3 ~ CN3 CN3 _ Si ~ t si o _ si _CN3 CH3 _ CH3 N CH3 By substitution of som~ of the methyl groups w7th other organic or organo functional groups, such as vinyl, phenyl, trifluoropropyl, and amino, other organopolysiloxane fluids can be produced. The table shown on the following page, shows the properties of various unsubstituted dimethyl-silicone fluids as well as those dimethylsilicone fluids having between 10 mole percent to about 35 mole percent substitution of phenyl groups~

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TAB

S~bstituted Dimeth~ licones Unsubstituted 10/o Phen~l 25% Phenyl 45% Phenyl Dimethylsilicones ~ Methyl viscosit3r, cs~k,at 25 C. 100 1,0~ 10,000 100 100-150 500 Specific 0.97 0,97 0.97 Gr. 25 25~i 1.403 1.404 Flash Pt. 600 600 600 520 570 Min. DF
(Open) Cup Dielectric 2.74 2.76 2,7 Constant V.T,C.-3~ 0.60 0.62 0,61 0.62 0.76 0.83 Freezing Pt, F. -67 _S8 _50 Thermal Conductivity3~3~ .00037 .00038 S3urface 21 21 21 Tension,Dynes Per Cm. at 25C. e ~pecifiOc Heat 0.35 0.35 CaljG/ C
V~10-V100 -3~V.T.C. (viscosity temperature coefficient) is V100 Where ~ is the viscosity Cal.X Cm 3~3~Thermal Conductivity ~ At 50C.

Generally organopolysiloxane fluids are available as mixtures of polymers of varying chain length, It has been found for purposes o~ the invention that the viscosity of the silicone fluids is a measure of the effect_ ive~ess. Silicone ~luids can be used which have a viscosit~ range up to about 100,000 centistokes, Preferably, the viscosity of the silicone fluids to be used should be in the range of from about 100 centistokes up to about 10,000 centi~tokes. Most preferably, ~he viscosity is in the range of about 30~_400 centistokes~ Apparently, as the viscosity bec~mes too great, there is difficulty in penetration of the silicone fluids into the surface to be 6 _ ..

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~5~7~5 protected. When the viscosity becomes too low, the average chain length of polymer is apparently too small to provide adequata protection.
The exact choice of an organopolysiloxane f'luid or fluid mixture as described above, will depend upon the identity of the surface to be protected.
It has been found that for most applicatîons, the standard unsubstituted ; dimeth~lpolysiloxane ~luid is an excellent choice, particularly for the treat- `' m~nt of rubber and vinyl surfaces In other instances, it has been found that the inclusion of up to about 10% by weigh~, based on the weight of the dimeth_ ylpolysiloæana fluid, of a commercially available amino substituted dimethyl_ polysiloxane fluid provides increased adherence to the surface to be protected.
This combination is particularly advantageous for treatm~nt of metal surfaces.
The use of the phen~l and other substituted dimethylpolysiloxane fluids is a matter of choice, depending upon the material to be treated and/or the environ_ mental stresses to which the surface will be exposed Tha silicone fluid or mixture of fluids is used in the form of a water emulsion. The amount of water ~hich can be used is preferably from about 65% to about 660% by w~ight, based on the weight of the silicone fluid However, thc amount of water can be as high as about 5000% by weight if desired It is believed that tha small particla size of the silicoIIe in the ~mulsion (usual'ly lass than about 1/2 micron) greatly ~acilitates penetration of the silicone into the surface to ba protected.
Emulsions of silicone fluids in water are available from several major chemical companies, including for example, General Elec~ric Company; ;~
Silicone Products Department of Waterford, New York; Union Carbide Corpora~ion;
Silicones Division of West Virginia; and Dow Corning Corporation of Midland~
'~ Michigan. The silicone emulsions usuall~ contain from about 35% to about 50% ;~
by weight o~ a silicone fluid or fluid mixture, with the remainder being mostly !~ water and small amounts of emulsifier and adju~ant materials such as a rust inhibitor. A typical emulsion contains 35 parts by weight dimeth~lpolysiloxane, 10 parts by weight of an emulsifier, such as nonylphenol~ 5 parts b~ w~ight of ~;
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a rust inhibitor, such as sodium nitrite, and 65 parts by weight of water, As noted above, a certain measure of protection can be imparted to surfaces by application of a silicone emulsion as obtained from the manufact_ urer. However, significantly greater and longer lasting protection, as w~ll as enhanced appearance is possible by including in the preservative composit-ion, at least one water miscible or water soluble polyol compound. The amount of the polyol compound to be included in the preservative composition, ranges from about 50% by weight to about 65~ by weight, based on the weight of the polysiloxane fluid Examples of polyols which can be used in the preservative composit-ion according to the invention include c~mong others: glycerin ( 1, 2, 3 -propanetriol); diethylcne glycol; 1, 3 _ prop~lene glycol; 1, 2 _ propylene glycol; 1, 4 - butylene glycol; 2, 3_butylene glycol; 1, 3 _ butylene glycol;
1, 2, 6 _ hexanetriol; dipropylene glycol; tetramethylene gl~col; pentaeryth_ ritol; dipentene glycol; tetraethylene glycol; dimethylhexanediol; 2, 2 _ dimethyl - 1, 3 - butanediol; dimeth~loldioxane; tetra~thylene glycol; ethyl_ ene glycol; li~uid polyethylene glycols, and liquid polypropylene glycols, mannitol~ sorbitol, (hexahydric alcohols).
Of the above ingredients, diethylene glycol and glycerin are most preferrad for use in the composition. The preferred amount of such materials to be used is, based on the weight of the polysiloxane fluid, from about 0.5%
to about 10% by weight of diethylena glycol, and from about 60% to about 10%
~y weight of glycerin.
Dieth~lene glycol serves to aid in ~he penetra~ion of the silicone and other constituents into polymeric materials such as rubber and plastics.
It is soluble in water but once applied to a rubber surfac~, it also serves to seal the surface against water. In addition, diethylen0 glycol serves to gi~e body to the preservative mixture and to impro~e adhesion of the other constituents of the preservakive mixture to the surface. Glycerin also helps seal the surface, aids in penekration, and adds body to the mixture, increas_ - 8 _ .~., ,: " : ' , ~ )7~S
ing its viscosity and providing a creamy character. The combination of glycerin with silicone contributes most to the improved appearance of the surface resulting frQm application of the mixture Application is facilitated and, as previousl~ explained~ the degree of gloss can be controlled, by the water in the mixture The other ingred_ ients are soluble or miscible in such an emulsion and are combined into the emulsion Dow Corning DC 36 dimethylsilicone emulsion is readily ~ailable and entirel~ suitable The examples in Table II below name that material as one of the constituents and the proportions of the several ingredients are specified by setting out the number of parts by weight of those ingredients in a mixture that includes one hundred parts by weight of DC 36.
An emulsion which appears to be the equivalent of the DC 36 dimeth~l I silicone emulsion, at least in the practice of this invention, includes thirty_ ~ive percent b~ weight of a dimethylpoLysiloxane fluid of under ten thousand centistokes viscosit~ together ~ith less than ten parts by weight of a nonion_ ic or covalent emulsifier such as a nonylphenol together with not more that five parts by weight of a rust inhibitor such as sodium nitrite or an organic phosphite and not more than sixty five parts by weight of water.
The above formulation assumes that the end product is to provide maximum gloss to the surface to be treated The water content is increased if a matt appearance is desired Also, it has been found that old or aged surfaces, particularly rubber and vinyl absorb considerably more water than newer surfaces. The maximum amwunt of ~ater that can be added without degrading the protective quality of the product is approximately one hundred and sixt~ five parts by weight if the product is merely wiped on the surface to be treated. If the surface is scrubbed clean with the product, up to 98 percent of water will still provide a satisfactory protection and appearance. If the water percent_ age is to be increased to achieve a semi_gloss or mat~ appearance, then that water can be added by increasing the proportion of water in the silicone-in_ .
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water emulsion, ~ Som~ specific examples of preservative compositions within preferred ; rangcs of proportion are presented below in Table II. It should be understood that the silicone emulsion formula described above can be substituted for the material unsubs~ituted dimethylsilicone emulsion, D.C 36, which contains 35%
b~ weight of dimeth~lsilicone having a viscosity of about 350 centistokes and an average particle size of~ 2 micron. The specific gravity of the emulsion at 24C is 0 96 and the pH is 8.5. The D.C. 36 emulsion used also contains small amounts of nonylphenol emulsifier, about 10 parts b~ w~ight; a rust ~a inhibitor, sodium nitrite, abou~ 5 parts b~ weight; and ~ater, about 65 parts b~ weight.

T~BLE II

Example ~ Parts by Weight of .
Number D,C. 36 Dieth~lene G~lcol Gl~cerin 35% Dimethy~_ Silicone Emulsion _ . , . __. ~' 100 ~ 1~

2 100 0.5 8 ~

3 100 3 20 e

4 100 2 21 7 100 0.25 10 8 _ ~.5 10 i The mat~rial de~ined in ~xample 1 appears to be the best in the terms of the enhancement of the surface appearance of rubber surfaces both old and ncw and in terms of its protective character. Th~ second e~ample sets out what is sonsidered to be a product which, although not quite as good, also performs well the ~unctions of enhancing appearance and providing , ,~ :.`.'~

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protection. The third e~ample sets out a composition that provides satisfact ory results at any range of added trater from one to one hundred parts by t~ight.
; Examples 4, 5 and 6 include what is considered to be the optim ~uantity of diethylene glycol together with varying quantities of gl~cerin.
E~ampla 4 t~ith its twenty~one p~rts of glycerin is noticeably less desirable than the Example No. 3 with only twenty parts of glycerin. Accordingly, the conclusion is drawn that a per~erred formulation includes less than twenty~
on~ parts by weight of glycerin Example 5 with its five parts of glycerin is satisfactory whereas E~ample 6 t~ith four parts of gl~cerin appears to have less merit. It is concluded that at least about fi~e parts of glycerin are required in the preferred material.
Exa~ples 7 and 8 attempt to find the limits of diethylene glycol inclusion. Whereas in Example 2 one half part of diethylene gl~col appears to be satisfactory, in Example 7 the inclusion of only one fourth of one part of diethylene glycol appears to provide a less than completely satisfactory result notwiths~anding that the amount of glycerin is ten parts by weight which is considered to be optimum Similarly, while three parts by w~ight of diethylene glycol result in a satisfactory material in the Example 37 it ap-paar~ that too much diethylene glycol is included in the Example 8.
Less desirable, but still a good, inexpensive and easily applied product i9 provided by mix~^ng only silicone emulsion with glycerin. In the pr0ferred rang~ of proportions, the mixture includes more emulsion than glycerin. This form is intended primarily as an additive to wash water or isoprop~l alcohol used for washing tires It will not harm the tirss or auto-m~bile parts or paints if used without dilution although to use it that way is was~eful. The percentage of glycerin is relatively grea~ so that the product has "body" enough to inspire con~idence and encourage dilution.
The silicon~ emulsion has a milky appearance7 if it is desired to change the coloring to enhance marketability~ that can be done. One of the advantages of the invention is that water soluble dye can be aclded in quant-:

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ities small enough to al*er the product's appearance materially without affecting the colorîng of the surface *o be treated In addition to rust inhibitors and dyes, other adjuvant materials, for example ultr~violet absorbers, can be added to the preservativg ccmposit-ion of the invention These materials are advantageously used but are not critical to the composition. For example, in some instances it might be desirable to include small amounts of an antifoam agent to aid in bottling of the preservative. In addition, an anti_microbial could be added to increase shelf life of the preservative and to aid in imparting such resistance to ~reated surfaces. Such adjuvant materials should, however, be water soluble or water miscible. Various other adju~ant materials are known7 and the use theresf will be apparent to those skilled in the art.
The mixtures that are preferred for rubber treatment are preferred for the treatment of polymers generally. The description above, while primar_ ily cast in terms of rubber treatment, is equally applicable to treatment of synthetic rubbers, vinyls, acr~lics, other plastics, painted surfaces, wood, leather and the like.
In practicing the process of the invention, whether using the emulsified silicone in water alone, or the preferred preservative composition of the invention, it has been found that there are several important staps to be taken.
First, the surface which i9 to be treated should be thoroughly wetted by the preservativa composition, This can ba accomplished in an~ convenient manner, such as by rubbing, spraying, painting, immersion and the like.
After wetting the surface, it is important to ~llow sufficient time for the preservative composition to pen~trate the surface. During this time, it is believed ~hat the preservative composition is taken into the surface por~s by capillary action~ For best results, a period of at least about 24 hours should bs allowed for penetration, If lesser periods are resorted to, optimum results will not be achieved If desired, any surface cxcess can be ~ 12 _ ',' `' .
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~5~705 r~moved by a light rubbing, after the penetration period.
At least one additional application of the prese~vative should then be made to the surface in the same manner as for the first process steps.
After waiting an additional twenty-four hours, the surface can then be lightly buffed with a soft cloth to provide increased gloss, if desired. Preferabl~, however, the preservative is applied to the surface at least three times3 with a twenty four hour lapse of time for penetration between each application. ;
B~ follo~ing these steps, maximwm protection of the surface which is being treated will be obtained for the longest period of time. Additional coatings can be applied if desired, However, it is believed that in most cases, ~hree applications are adequate.
In addition to the advantages mentioned, the surfaces treated with the pres~rvative composition of the invention shed water and dirt, and cut static electricity. In addition~ the protective, inner molecular surface layer which is formed protects against ozone, ultra~iolet rays, oxygen, and elements of smog, such as nitrogen oxides, nitric acid vapor~ and sulphur oxides. ~;
Furthermore, the appearance of the surface after treatment is very natural, providing a soft lustre e~en to severely damaged surfaces, such as rubber tires, -While the invention was primarily designed for use on rubber and vinyl and equivalent polymer materials, it has been found to work equall~ well on many other surfaces, including for example, leather, wood~ paint, and many other materials.
The following further exam~les are presented for purposes of ill_ ustrating the inven~ion, ~ ' .
A preservativo according to the in~en~ion was tested according to the methodæ outlincd in A~S~TDMD D-518, Procedure B, Outdoors South~rn 45 Exposura Testing3 using as the testing material, natural rubber s~wim fin _ 13 -.

~5~7~i stock of a non_black rubber material The preservative composition which was used was comprised of 100 parts by weight of an aqueous emulsiong containing 35 parts b~ weight of unsubstituted dimethylpolysiloxane fluid, 10 parts by weight nonylphenol emulsifier, 5 parts by weight of sodium nitrite rust inhibitor, and 65 parts by weight of water. The dimethylpolysiloxane fluid had a viscosity of about 300 c~ntistokes and a particle size of less than 2 mirron. The specific ; gravity o~ the aqueous emulsion at 77 was 0.99, and the ~ was 8.S, To the above described aqueous silicone em~sion was added, with stirring, 50 parts by weight of water, 8 parts hy w~igh~ of glycerin, and 2 parts by w~ight of diethylene glycol. When ~horoughly mi~ed, the resulting preservative composition was used as described in the following procadure.
Ten, bent loop samples of natural rubber type swim fin stock were mounted ~ide by side on a wooden test fixture and numbered one through ten.
Sample No, 1 was left untreated throughout the test, and samples 6 through 10 were cleaned with isopropyl alcohol prior to the application of the pre_ servative.
Sample No 2 was wetted with the preservative cQmposition and allowed to dry for one hour At the end of this time, the surface was rubbed lightly, followed by a 24 hour drying period, and a final light buffing.
Sample No, 3 was wetted with the proservative composition and allowed to dry for one hour, The preservative was applied a second time followed by a one hour dr~ing period and a light buffing. After 24 hours, the preser~at-ive was applied again, followed b~ a one hour dr~ period, after which the surface was rubbed lightly and buf~d Sample No, 4 was wetted with the preservative composition, followed b~ drying for one hour, and lightly rubbing~ After 24 hours, the aample was lightly bu~ed, followed b~ another 48 hour period~ after which a second application of the preservative was made. This was allowed to dry for one hour, then rubbed lightly, ~ollowed b~ another 24 hour drying period, and a .. . . . . . . . .

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~05~705 light buffing Sample No 5 was treated in the same manner as Sample No. 3, e~cept that an additional application was made after seven da~s. After drying for one hour, the surfacs was ligh~ly rubbed, follo~d by a light buffir~.
~ Samples 6 through 10 received a treabment which corresponded respect-; ively to Samples 1 thraugh 5 except for the initial isopropyl alcohol clean_ sing Except for the actual application of ~he preservative, and light wiping or buffing which was done with a soft cotton cloth, the ~amples were kept out of doors. It should be noted that the rubber swIm fin stock which was used for the experiment, was made of a ~ater resistant material which results in a somewhat slo~er penetration time of thc preservative than would be the case for average rubber compositions, Results In examining the surface of the samples, a ten power magnification glass was used in place of the seven power magnification called ~or in the A S.T~M. test. The tesking was terminated after 30 days axcept where other-wise indicated. A light buffing to remove accumulated dirt and dust was ; applied to the samples after 10, 20 and 30 days.
Control Sample No 1 which received no treatment with the preservat-ive shcwed cracking after two days, The cracking initially appeared as aslight chalking on the surface which becam~ more severe with each passing day . , .
to form severe and deep cracks after seven days, when equilibrium was estab-lished.
Sample No, 2 showsd cracking after three da~s on roughly ~ive percent of the total area~ The cracks became progressively larger and deeper over the fourth, fifth, and sixth days, to finally cover approximately 25% of the total area After the seventh day, equilibrium was e3tablished.
Sa~ple No, 3 shcwed a v~r~ ~mall amount of cracking on about one percent of the area after three days. The cracking bec~me more severe and '~ . .
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.-, 7~ ~gradually increased to about 25% of the surface area during the fourth through se~enth da~s, after which equilibrium was established.
Sample No 4 showed no cracking, even after ~0 days. At this point, the test was stopped.
Sample No. 5 showed a few small cracks on abou~ one percent of the surface area after four days. On the seventh day ~hen another application of the preservative was administered, there had been no further change. The cracks grew sllghtly larger and deeper after the tenth day when equilibrium ~was established Control Sample No 6 shawed small cracks on about 50% of the surface area after about tNo days These cracks became progressively more severe until about 70% of the area was cracked af~er the fourth day, In addition, thore was spotty chalking, and the cracking grew even deeper until thc tenth day, when-equilibrium was established Sample No 7 showed a few tin~, short cracks on about 1% of its surface area after thr~e days. These cracks became progressively more severe until about 35% o~ the surface area was affected by the tenth day, when equil_ ibrium was establishedO
Sample No 8 showed a few small cracks on less than l~o of its surface area after about four days These cracks became more severe and a few additional cracks showed, up to the tenth day when equilibrium was established~ ;
Sample No 9 showed no cracks throughout the test.
Sample No 10 showed no cracks throughout the test.
It was ~ound that when two to three applications of ths preservati~e were made to the samplesg allowing for a 24 hour period for p~netration be_ twaen each application, that there was a significant amount of protection provided b~ the preservative to the rubber This was evidenced by the absence of cracking in samples 4~ S, 9 and 10. In those samples ~hich did not allDw :
for the 24 hour penetration period, protection was still better than the 16 _ ~.

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untreated samples. -Exa ple 10 The preservative used in Example 9 was sponged onto the outer side wall of a standard automobile tire. The inner opposite side was left untreat-ed for control purposes. After 24 hours, the treated side was lightl~ buffed with a soft cloth, and another application of the p3~servative was sponged over all. This application was allowed to penetrate for 24 hours followed by a light buffing and the application of an additional coat. After another ~-24 hours, the treated surface was lightly buffed The tire was then driven under normal driving conditions for 2Q,000 miles, At the end of this time, the outer side wall which was treated with the preservative appeared smooth, black and strong, similar to a new tir~
The untreated inner wall showed the expected surface cracking and rubber doterioration normally found in tires after a period of 20,000 miles of use.
Example 11 Substantially the same procedure as in Example 10 is repeated, except that the preservative composition includes an enulsion based on amine_sub_ stituted dimethylpolysiloxane in place of the unsubstituted dimethy~polysil_ oxane emulsion.
After application to the rubber tire as describedg the tire is then driven for 10,000 miles in summer desert conditions, The treated outer side wall remains smooth and strong, while the untreated inner side wall shows severe cracking and rubber deterioration.
Example 12 The dimethylsilicone emulsion of Example 9 without polyol additives, is used to treat the outer side wall of a tire substantiall~ as described in Example 10. At th~ end of the 20,000 mile period of use, the untreated inner side wall is found to show surface cracking and severe rubber deterioration.
The treated side wall is found to show surface cracking over a portion of the surface areaO
, ''.
' , .. . , ; ~ , ~IL05~7~i Thus, ~hile some protection is afforded using the silicone emulsion alone, substantially greater protection is provided by the preferred composit_ ion of the invention which includes diethyleng glycol and gl~cerin as demon_ ;~
strated in Exampl0s 10 and 11 Example 13 A preservative composition is prepared followir~ the procedure of Example 9. To the resulting composition is added, ~ith stirring, 10 parts by w~ight o~ a 35% by weight aqueous emulsion o~ amino_substituted c~th~l-polysiloxane having a viscosity of about 400 centistokes. When thoroughly mixed, the preservative c~mposition is used to ~reat new, painted ~ uminum outdoor patio furniture having vinyl web seats, The preservative is sponged onto the painted surfaces and vinyl plast-ic webbing of one patio chair, while another is untreated for control purposes.
After 24 hours penetration, the surface is re~etted as before. ~ftar 24 hours, an additional rewetting of the surface is applied, followed by 24 hours of penetration and a final light buffing of the surfaces.
A~ter 12 months outdoor exposure, the treated chair is examined and compared to the untreated chair of the same materials. At the end of this time, the untreated chair shows dullness and slight chalking of the painted surfaces, together with slight crazing, and fading in some areas, The vinyl webbing appears dulled.
The treated chair b~ contras~ appears to ha~e retained its new look with the painted surfaces retainirlg a soft lustre and no appearance of dull-ness, chalking or crazing. The vinyl webbing of the ~reated chair also app~
ears like new.
'~

_ 18 -, s ;l Th~ invention thus described provides a process using an aqueous emulsion of dimethylpolysiloxane fluid which may be partially substitu~ed with, ~`
for example, vinyl, trifluoroprop~l, phenyl, and amino groups to preserve natural and synthetic polymers, painted surfaces, porcelain, lea~her, and wood.
By including from 15~o to about 65% by weight, based on the weight of the silicon~ fluid, of a water miscible or water soluble pol~ol compound, a superior preservative com~osition is provided, "
.:

Claims (11)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process for preserving and renewing surfaces, particularly natural and synthetic polymers, wood, leather, metal and porcelain, comprising: (1) wetting the surface with a composition comprising an emulsion of at least one water-emulsifiable organopolysiloxane fluid and, based on the weight of the organopolysiloxane fluid, from about 65% to about 5,000% by weight of water; (2) allowing said composition to penetrate the surface; and, (3) repeating steps 1 and 2 at least one time.

2. A process as claimed in Claim 1 wherein: at least about 24 hours is allowed to elapse for penetration prior to rewetting of said surface and wherein steps 1 and 2 are repeated at least two times.

3. A process as claimed in Claim 1 wherein: the surface is lightly buffed at the end of each period of penetration prior to rewetting of said surface.

4. A process as claimed in Claim 1 wherein: said composition further comprises, based on the weight of the organopolysiloxane fluid, from about 15% to about 65% by weight of at least one water miscible polyol component.

5. A process as claimed in Claim 4 wherein said polyol component comprises based on the weight of the polysiloxane fluid: from about 0.5% to about 10% by weight of diethylene glycol; and, from about 60% to about 10%
by weight of glycerin.

6 A process as claimed in Claim 1 wherein: said organopolysiloxane fluid is a dimethylpolysiloxane fluid having a viscosity of from 100 to 10,000 centistokes; at least about 24 hours is allowed for penetration prior to each rewetting of said surface ; and wherein steps 1 and 2 are repeated at least two times.

7. A preservative composition comprising: at least one water-emulsif-iable organopolysiloxane fluid emulsified in from about 65% to about 5,000%

by weight of water based on the weight of the polysiloxane fluid; and from about 15% to about 65% by weight based on the weight of the polysiloxane fluid of at least one water miscible polyol component.

8. A preservative as claimed in Claim 7 wherein: said water is present in an amount of from about 65% to about 660% by weight, based on the weight of the polysiloxane fluid.

9. A preservative as claimed in Claim 8 wherein: said polyol component comprises, based on the weight of the polysiloxane fluid: from about 0.5%
to about 10% by weight of diethylene glycol and from about 60% to about 10%
by weight of glycerin.

10. A preservative as claimed in Claim 9 wherein: the organopolysilo-xane fluid is a dimethylpolysiloxane fluid having a viscosity of from 100 to 10,000 centstrokes.

11. A preservative as claimed in Claim 7 wherein: said polyol is glycerin.