Aqueous silicone emulsions as bladder lubricants

An aqueous organopolysiloxane emulsion containing (1) hydroxyl-containing organopolysiloxanes, (2) organohydrogenpolysiloxanes, (3) a lubricant having a melting range of from 25.degree. to 80.degree. C., (4) a thickening agent, (5) a surfactant, and (6) water and an antifoam and bactericide, if desired, which may be used as a bladder lubricant for molding tires.

The present invention relates to aqueous silicone emulsions and more 
particularly to aqueous organopolysiloxane emulsions which may be used as 
bladder lubricants. 
BACKGROUND OF THE INVENTION 
In manufacturing tires, the actual shaping of the tire is caused by 
inflating a rubber bag inside a green tire carcass to force the tire into 
shape within the mold. Generally, there is substantial movement between 
the outer contact surface of the bladder, and the inner surface of the 
green tire during the expansion phase of the bladder prior to fully curing 
the tire. Likewise, there is considerable relative movement between the 
outer contact surface of the bladder and the cured inner surface of the 
tire after the tire has been molded and vulcanized during the collapse and 
the stripping of the bladder from the tire. 
It is essential that there be sufficient lubrication between the bladder 
and the inner surface of the tire in order to reduce friction between the 
bladder and the inside of the raw tire and allows for optimum slip of the 
bladder during the shaping process when the raw tire and bladder are in 
friction with one another. In addition, the lubricant also serves to 
channel the trapped air and/or gasses during high temperature curing. 
Finally, at the termination of the vulcanization cycle, the lubricant 
allows for the release and removal of the bladder from inside the tire. 
Aqueous organopolysiloxane emulsions containing treated inorganic silicates 
have been used as lubricants for molding tires. These emulsions are 
described in, for example, U.S. Pat. No. 4,184,880 to Huber et al in which 
an aqueous diorganopolysiloxane emulsion containing dispersed inorganic 
silicates which have been treated with organosilicon compounds to impart 
hydrophobic properties to the surfaces of the inorganic silicates have 
been employed as release agents for manufacturing tires. Also, U.S. Pat. 
No. 3,713,851 to Cekada describes aqueous organopolysiloxane emulsions 
which have been used as bag lubricants for molding tires in which the 
emulsion contains an alkyl methyl siloxane fluid including non-flowing 
gums, polyalkylene glycols, mica, carboxymethylcellulose, lecithin and 
water. U.S. Pat. No. 4,431,452 to Comper et al discloses a lubricating 
composition for a tire bladder comprising (1) a hydroxyl-terminated 
polydimethylsiloxane having a viscosity of up to about 25,000,000 
centistokes at 25.degree. C., (2) a hydroxyl-terminated 
polydimethylsiloxane having a viscosity up to about 120,000 centistokes at 
25.degree. C., (3) a polyalkylene glycol, (4) bentonite clay and (5) a 
surfactant. U.S. Pat. No. 3,872,038 to Adams et al discloses an aqueous 
emulsion which is useful as a bladder lubricant comprising (1) a silicone 
gum, (2) an organopolysiloxane fluid, (3) polyglycols, (4) mica, (5) 
lecithin, (6) sodium carboxymethylcellulose, (7) emulsifying agents and 
(8) water. 
A bladder lubricant is described in U.S. Pat. No. 4,359,340 to Comper et al 
in which an aqueous emulsion comprising (1) a polydimethylsiloxane having 
a viscosity up to about 25,000,000 centistokes at 25.degree. C., (2) a 
methylhydrogen silane having a viscosity of from 20 to 40 centistokes at 
25.degree. C., or a dimethylhydrogen silane having a viscosity of from 80 
to 120 centistokes at 25.degree. C., (3) a metal salt of an organic acid 
and (4) surfactants is applied to the bladder surface. 
An aqueous emulsion for treating organic fibers is described in U.S. Pat. 
No. 4,436,856 to Huhn et al in which the aqueous emulsion containing (1) 
an organopolysiloxane having at least two monovalent SiC-bonded organic 
radicals per molecule with a basic nitrogen atom, (2) an 
organopolysiloxane having at least 3 Si-bonded hydrogen atoms per 
molecule, (3) a catalyst for the condensation of Si-bonded condensable 
groups, (4) an emulsifier and (5) a diorganopolysiloxane containing an 
Si-bonded terminal hydroxyl group. 
Aqueous organopolysiloxane emulsions employed heretofore as bladder 
lubricants in manufacturing tires have several disadvantages. For example, 
pre-formulated aqueous organopolysiloxane emulsions have stability 
problems in which the areas of ingredient settling, compaction and/or 
degradation during storage and/or during transportation, or upon 
inordinate changes such as freeze-thaw cycles that might be encountered. 
In order to reduce the sliding friction and improve venting between the 
bladder and the inside of the tire, it has been necessary to increase the 
amount of filler or the amount of silicone polymer present in the 
composition and as the amount of filler increased, settling and compaction 
become a problem. In addition, many of the aqueous organopolysiloxane 
emulsions are not stable over long periods of time and have a tendency to 
"cream" and/or form an oil on the surface. Also, some of the 
organopolysiloxane emulsions contain catalysts which have a tendency to 
accelerate the degradation of the resultant emulsion and release hydrogen 
as a by-product. Furthermore, many of the aqueous organopolysiloxane 
emulsions have to be applied to the bladder just prior to shaping the 
tire, otherwise good lubricating properties and release properties are not 
achieved. 
In contrast to the aqueous organopolysiloxane emulsions described 
heretofore, the aqueous organopolysiloxane emulsions of this invention are 
stable over long periods of time. Generally, the aqueous 
organopolysiloxane emulsions of this invention do not release hydrogen 
during storage. In addition, several tires can be manufactured with one 
application of the aqueous organopolysiloxane emulsions of this invention. 
Moreover, the aqueous organopolysiloxane emulsions of this invention can 
be applied to the inside of the green tire carcass and allowed to stand 
overnight without affecting the release properties. Furthermore, the 
inside of the green tire carcass can be coated with the aqueous 
organopolysiloxane emulsions away from the press area and then transferred 
to the press area where they are molded. 
Therefore, it is an object of the present invention to provide an aqueous 
organopolysiloxane composition which may be used as a bladder lubricant. 
Another object of the present invention is to provide a composition which 
is stable over a long period of time. Another object of the present 
invention is to provide an aqueous organopolysiloxane emulsion which will 
give numerous releases per application. Still another object of the 
present invention is to provide an aqueous organopolysiloxane emulsion 
which may be applied to the inside of a green tire carcass several hours 
before the tire is molded. A further object of the present invention is to 
provide a method for preparing an aqueous organopolysiloxane emulsion. 
Still a further object of the present invention is to provide a method for 
molding tires using an aqueous organopolysiloxane emulsion. 
SUMMARY OF THE INVENTION 
The foregoing objects and others, which will become apparent from the 
following description are accomplished in accordance with this invention, 
generally speaking, by providing aqueous organopolysiloxane emulsions 
comprising (1) a hydroxylcontaining organopolysiloxane gum having a 
plasticity value of from 50 to 100, (2) an organohydrogenpolysiloxane 
having an average of at least 3 Si-bonded hydrogen atoms per molecule, (3) 
a lubricant having a melting range of from 25.degree. to 80.degree. C., 
(4) a thickening agent, (5) surfactant and (6) water. Other ingredients 
which may be added to the organopolysiloxane emulsions are antifoams and 
bactericides, if desired. 
The aqueous organopolysiloxane emulsions are preferably prepared by mixing 
the surfactant with sufficient water and acid to form a paste; then the 
lubricant and hydroxyl-terminated organopolysiloxane gum is added to the 
paste with mixing and then the methylhydrogenpolysiloxane fluid is added 
with continual mixing. To the resultant mixture is then added the 
remainder of the water, antifoam, bactericide and sufficient ammonium 
hydroxide to increase the pH to a level of from 8 to 10. After mixing for 
a period of time, the thickening agent and sufficient acid is then added 
with agitation to reduce the pH to a range of from 4 to 6. After the 
emulsion has been thoroughly mixed it is then filtered. 
DETAILED DESCRIPTION OF THE INVENTION 
The hydroxyl-containing organopolysiloxane gum has an average unit formula 
EQU R.sub.n SiO.sub.(4-n)/ 2 
where R, which may be the same or different represent monovalent 
hydrocarbon radicals or halogenated monovalent hydrocarbon radicals having 
from 1 to 18 carbon atoms and n has an average value of from 1.9 to 2.1. 
In the above formula R represents alkyl radicals such as methyl, ethyl, 
propyl, butyl, octyl, dodecyl and octadecyl radicals; aryl radicals such 
as phenyl, diphenyl and naphthyl radicals; alkenyl radicals such as vinyl 
and allyl radicals; cycloalkyl radicals such as cyclobutyl, cyclopentyl 
and cyclohexyl radicals; alkaryl radicals such as tolyl, xylyl and 
ethylphenyl radicals; aralkyl radicals such as benzyl, alpha phenyl ethyl, 
beta phenylethyl and alpha phenylbutyl radicals and halosubstituted 
radicals described above. 
The organopolysiloxane gum may be any linear or branched chain compound 
having an average of from 1.9 to 2.1 organic radicals per silicon atom. In 
addition to the unit shown above, the organopolysiloxane gum may also 
contain units which correspond to the following formulas 
EQU SiO.sub.4/2,.sup.R SiO.sub.3/2 and R.sub.3 SiO.sub.1/2, 
where R is the same as above. These organopolysiloxane gums can be either 
homopolymeric or copolymeric materials containing 2 or more different 
siloxane units and the organic radicals attached to any one silicon atom 
can be the same or the radicals attached to any one silicon atom can be 
different. Mixtures of polymers can, of course, also be used if desired. 
Preferably, at least 75 molar percent of the silicon atoms present in the 
organopolysiloxane gum are substituted with alkyl radicals, among which 
the methyl radicals are preferred. Other radicals which may be present are 
preferably vinyl and/or phenyl radicals. Generally, these gums will have 
an R/Si ratio of from about 1.9 to about 2.1 organic groups per silicon 
atom and a plasticity value of from 50 to about 100 millimeters as 
measured by the parallel plate plastometer test described in A.S.T.M. Test 
D-926-67. 
The organohydrogenpolysiloxanes employed in the emulsions of this invention 
generally consist of units of the formula 
EQU R'.sub.m SiO.sub.4-m/ 2 
where R' represents hydrogen, a monovalent hydrocarbon radical or a 
halogenated monovalent hydrocarbon radical having from 1 to 18 carbon 
atoms in which at least 2 and preferably 3 Si-bonded hydrogen atoms are 
present per molecule and m is 1, 2 or 3. Preferred 
organohydrogenpolysiloxanes are those consisting of R'SiO units, R'.sub.2 
SiO units and R'.sub.3 SiO.sub.0.5 units in which R' is the same as above 
and an Si-bonded hydrogen atom is present for each 3 to 100 silicon atoms. 
It is preferred that the organohydrogenpolysiloxanes have a viscosity of 
from about 10 to 100 mPa.s and more preferably from about 30 to 80 mPa.s 
at 25.degree. C. 
The organohydrogenpolysiloxanes may also contain monovalent having 
aliphatic unsaturation as well as Si-bonded hydrogen atoms in the same 
molecule. 
It is preferred that the monovalent hydrocarbon radicals represented by R' 
each contain from 1 to 18 carbon atoms. Examples of suitable hydrocarbon 
radicals are alkyl radicals such as the methyl, ethyl, n-propyl, isopropyl 
radicals as well as the octadecyl radicals; cycloalkyl radicals such as 
the cyclohexyl and cycloheptyl radicals; aryl radicals such as the phenyl 
radical; alkaryl radicals such as the tolyl radicals and arylalkyl 
radicals such as the benzyl and the beta phenylethyl radicals. Examples of 
substituted hydrocarbon radicals represented by R' are halogenated 
hydrocarbon radicals such as the 3,3-trifluoropropyl radical and the 
ortho-, para- and metachlorophenyl radicals. Because of their 
availability, it is preferred that at least 50 percent of the R' radicals 
which do not consist of Si-bonded hydrogen atoms be methyl radicals. 
Examples of suitable lubricants which may be employed in the aqueous 
emulsions of this invention are waxes and esters of higher fatty acids, 
which have a melting range of from 25.degree. to 80.degree. C., and more 
preferably from about 30.degree. to 70.degree. C. Preferred examples of 
suitable fatty acid esters and waxes are lanolin, beeswax, spermaceti, 
Japan wax, bayberry, citrus peel oils, sugar cane wax, candelillia and 
synthetic waxes such as carbowax. 
Examples of suitable surfactants which may be employed in the aqueous 
emulsions of this invention are anionic, cationic and nonionic surfactants 
such as alkyl or aryl polyglycol ethers or alkylphenyls such as 
polyoxyethylene alkyl phenyls, polyoxyethylene sorbitan hexastearate, 
polyoxyethylene isotridecyl ether, trimethylnonyl ether of polyethylene 
glycol containing from 6 to 15 ethylene oxide units per molecule, 
polyoxyethylene sorbitan oleate having a saponification number of from 102 
to 108 and a hydroxyl number of from 25 to 35. It is preferred that a 
mixture of nonionic surfactants be employed such as a mixture of 
ethoxylated alkyl phenols having varying chain links. 
Several thickening agents may be employed in the emulsions of this 
invention to aid in the stability of the emulsion. Examples of suitable 
thickening agents are magnesium aluminum silicate, water-soluble cellulose 
such as sodium carboxy methyl cellulose, sodium carboxymethyl hydroxy 
ethyl cellulose, hydroxy ethyl cellulose, methyl cellulose, methylhydroxy 
propyl cellulose, ethyl hydroxy ethyl cellulose, methylethyl cellulose, 
methyl hydroxy ethyl cellulose. The thickening agent imparts viscosity to 
the emulsion, and stabilizes the emulsion over a pH range of from 3 to 11 
and keeps the internal phase droplets suspended and separated. It also 
reduces the tendency of diluted emulsions to thin or break at room 
temperature, as well as at elevated temperatures. 
The aqueous organopolysiloxane emulsions of this invention preferably 
contain from about 20 to 70 percent by weight based on the weight of the 
emulsion of the hydroxylterminated organopolysiloxane gum and more 
preferably from about 30 to 55 percent by weight of hydroxyl-terminated 
organopolysiloxane gum. The amount of organohydrogenpolysiloxane fluid may 
range from about 0.5 up to about 25 percent by weight and more preferably 
from about 4 to about 10 percent by weight. It has been found that the 
ratio of organohydrogenpolysiloxane fluid to hydroxyl-terminated 
organopolysiloxane gum is critical and the higher the ratio the greater 
the number of releases per application. However, when the ratio exceeds 
about 25 percent by weight then there is a substantial decrease in the 
stability and the release properties of the resultant emulsion. The amount 
of lubricant may range from about 0.05 up to about 5 percent by weight and 
more preferably from about 0.3 up to about 1 percent by weight based on 
the total weight of the aqueous emulsion. Generally, the surfactant will 
range from about 4 to about 10 percent by weight and more preferably from 
about 5 to 9 percent by weight, based on the weight of the 
organopolysiloxane emulsion. It is preferred that two or more nonionic 
surfactants be employed in order to obtain optimum stability of the 
emulsion. 
The amount of thickening agent employed in the aqueous organopolysiloxane 
emulsions may range from about 2 to 12 percent by weight and more 
preferably from about 4 to 8 percent, based on the weight of the aqueous 
organopolysiloxane emulsion. The amount of water will generally range from 
about 15 to about 60 percent by weight and more preferably from about 25 
to 50 percent by weight and more preferably from about 30 to 35 percent by 
weight, based on the weight of the aqueous organopolysiloxane emulsion. 
The lubricity of the aqueous emulsions of this invention may be further 
enhanced by the addition of polyalkylene glycols; however, it has been 
found that the addition of polyalkylene glycols reduces the number of 
releases per application. 
Polyalkylene glycols which may be incorporated in the silicone emulsions 
are those having the general formula 
EQU HO(R"O).sub.x H 
where R" is an alkylene radical having from 1 to 4 carbon atoms, x is a 
number of from 1 to 300 and has a melting point in the range of from 
0.degree. to 80.degree. C. 
Suitable examples of radicals represented by R" are methylene, ethylene, 
propylene, butylene radicals and mixtures thereof. 
Specific examples of polyalkylene glycols are polyethylene glycol, 
polypropylene glycols, polybutylene glycols, poly(ethyleneoxy-propylene) 
glycols, poly(ethyleneoxybutylene) glycols and poly 
(propyleneoxy-butylene) glycols. 
The amount of polyalkylene glycols which may be added to the 
organopolysiloxane emulsions of this invention may range from about 5 to 
10 percent by weight based on the organopolysiloxane emulsion and the 
polyalkylene glycols. 
Other ingredients, which may be added to the organopolysiloxane emulsions 
are antifoams and preservatives, such as bactericides. The amount of 
antifoam will generally range from about 0 to about 1.0 percent and more 
preferably from about 0.2 to 0.7 percent, based on the weight of the 
organopolysiloxane emulsion. Generally, from about 0 to about 0.3 percent 
of bactericide may be employed in these emulsions. More preferably though, 
the amount of bactericide will range from about 0.1 to about 0.2 percent, 
based on the weight of the aqueous emulsion. Other additives which may be 
included in the aqueous emulsions of this invention are rust inhibitors 
such as sodium nitrite, sodium nitrate and coloring agents and the like, 
which can be added in minor amounts to the emulsions of this invention. 
Although the aqueous silicon organopolysiloxane emulsions of this invention 
may be prepared by several techniques in a mechanical mixing apparatus, it 
is preferred that the nonionic surfactant and acid be mixed in a 
mechanical mixer with sufficient water to form a paste or grease-like 
composition. Generally, the amount of water ranges from about 10 to 25 
percent of the total amount of water employed in the emulsion. After the 
grease or paste-like composition has been formed the lubricant is then 
mixed in a mechanical mixing apparatus with the paste, then the 
hydroxyl-terminated gum is added slowly with mixing and then the 
methylhydrogenpolysiloxane fluid. The remainder of the water is then added 
slowly with mixing until the particle size of the micelles is below 10 
microns, then the antifoam and bacteriacide are added with sufficient base 
to increase the pH to a range of from 8 to 10. The mixture is then mixed 
for a period of time in order to form a pre-polymer and then the 
thickening agent and sufficient acid is added to reduce the pH to a range 
of from 4 to 6. After mixing for a period of time the resultant oil in 
water emulsion is then filtered. 
In adjusting the pH of the emulsion to a range of from 8 to 10, any basic 
material may be added to the mixture. Examples of suitable bases which may 
be employed are alkali metal hydroxides, alkaline earth metal hydroxides 
and ammonium hydroxide. Specific examples of alkali metal hydroxides are 
sodium hydroxide, potassium hydroxide. Other bases which may be employed 
are alkali and alkaline earth metal carbonates, such as sodium carbonate, 
calcium carbonate, sodium bicarbonate and sodium metasilicate as well as 
ammonia and ammonium hydroxide. 
Examples of suitable acids which may be employed in the aqueous emulsions 
of this invention are inorganic as well as organic acids. Specific 
examples of inorganic acids which may be employed are hydrochloric acid, 
sulfuric acid, orthophosphoric acid, sulfuric acid. Examples of organic 
acids which may be employed are oxalic acid, tartaric acid, maleic acid, 
citric acid, formic acid, lactic acid, acetic acid, benzoic acid and boric 
acid. 
The aqueous organopolysiloxane emulsion of this invention may be used as a 
bladder lubricant in manufacturing rubber tires in which a green tire is 
placed in a tire mold and the bladder is coated with the silicone emulsion 
of this invention. The mold is closed and the bladder expanded by 
application of internal pressure to force the tire outward against the 
mold surface to shape and cure the tire. The mold is then opened and the 
bladder collapsed and the shaped and the cured tire removed from the mold. 
In addition to applying the aqueous silicone emulsions of this invention to 
the expandable bladder, these emulsions may be applied to the inside of a 
green tire carcass and then inserted in the mold. 
It has been observed that when the aqueous silicone organopolysiloxane 
emulsions of this invention has been applied to the outer surface of an 
expandable bladder, that from 30 to 40 tires could be molded with one 
application of the emulsion. In the following examples all parts and 
percentages are by weight unless otherwise specified.

EXAMPLE 1 
An aqueous silicone emulsion is prepared by adding 0.5 parts of glacial 
acetic acid to a mixer containing 58 parts of water and 56 parts of a 
poly(ethyleneoxide) alkyl phenol having an HLB of 15 (Igepal.RTM. DM-730, 
available from General Aniline and Film Corporation) and 19 parts of a 
poly(ethyleneoxide) alkyl phenol having an HLB of 10.6 (Igepal.RTM. 
DM-530, available from General Aniline and Film Corporation) and then 
mixed in a mechanical mixer to form a paste or grease. To the resultant 
paste is added with mixing 6.3 parts of lanolin, 450 parts of a 
hydroxyl-terminated organopolysiloxane gum having a plasticity value of 
about 50 millimeters, about 40 parts of a methylhydrogenpolysiloxane fluid 
having an average of at least three Si-bonded hydrogen atoms per molecule 
and a viscosity of about 30 mPa.s at 25.degree. C. and about 245 parts of 
water. About 5.0 parts of a 10 percent silicone antifoam emulsion having a 
viscosity of 3000 cps at 25.degree. C. (available as SWS-214 from SWS 
Silicones Corporation) and 1.5 parts of a bactericide and 1.0 part of 
ammonium hydroxide (28 percent ammonia in water) are added to the 
resultant oil-in-water emulsion. The emulsion is mixed from about 2 hours 
at room temperature, then about 90.0 parts of a thickening agent 
containing about 1.5 percent by weight, Carbopol.RTM. A-941 containing 
acrylic acid polymers having a molecular weight of about 1,250,000, 
(available from B. F. Goodrich Chemical Company) and sufficient acetic 
acid are are added to the oil-in-water emulsion with mixing to provide a 
pH of from 4 to 6. The resultant emulsion is filtered, then diluted 1:1 
with water and sprayed onto the outer surface of a bladder and the coated 
bladder inserted inside a green tire carcass in a mold. The mold is closed 
and the bladder is expanded against the inside surface of the tire, which 
in turn presses the outer surface of the tire against the mold. After the 
tire is shaped and cured, the bladder is collapsed and the tire removed 
therefrom. It has been observed that from 30 to 40 tires could be molded 
with one application of the emulsion to the flexible bladder. 
EXAMPLE 2 
The silicone emulsion is prepared in accordance with the procedure of 
Example 1, except that 600 parts of a hydroxyl-terminated 
organopolysiloxane gum having a plasticity value of 80 are substituted for 
the 450 parts of hydroxyl-terminated organopolysiloxane gum and 6 parts of 
a methylhydrogenpolysiloxane fluid having a viscosity of 30 mPa.s at 
25.degree. C. are substituted for the 40 parts of 
methylhydrogenpolysiloxane fluid and 200 parts of water are substituted 
for the 303 parts of water. The resultant silicone emulsion exhibits good 
stability and exhibits excellent release properties when applied to the 
bladder or the inside of a green tire carcass and then molded into a tire. 
EXAMPLE 3 
The procedure of Example 1 is repeated, except that 200 parts of a 
hydroxyl-terminated organopolysiloxane gum having a plasticity value of 80 
are substituted for the 450 parts of hydroxyl-terminated 
organopolysiloxane gum and 6 parts of the methylhydrogenpolysiloxane fluid 
having a viscosity of 30 mPa.s at 25.degree. C. are substituted for the 40 
parts of methylhydrogenpolysiloxane fluid and 600 parts of water are 
substituted for the 303 parts of water. The resultant emulsion exhibits 
good stability and exhibits excellent release properties when applied to 
the bladder or the inside of a green tire carcass and then molded into a 
tire. 
EXAMPLE 4 
The procedure of Example 1 is repeated, except that 400 parts of a 
hydroxyl-terminated organopolysiloxane gum are substituted for the 450 
parts of hydroxyl-terminated organopolysiloxane gum and 15 parts of 
methylhydrogenpolysiloxane fluid are substituted for the 40 parts of 
methylhydrogenpolysiloxane fluid and 381 parts of water are substituted 
for the 303 parts of water. The resultant emulsion exhibits good stability 
at room temperature and exhibits excellent release properties when applied 
to the bladder or the inside of a green tire carcass and then molded into 
a tire. 
EXAMPLE 5 
The procedure of Example 1 is repeated, except that 430 parts of a 
hydroxyl-terminated organopolysiloxane gum are substituted for 450 parts 
of hydroxyl-terminated organopolysiloxane gum and 20 parts of lanolin are 
substituted for the 6.3 parts of lanolin. The resultant emulsion exhibits 
good stability at room temperature and exhibits excellent release 
properties when applied to the bladder in the molding of a tire. 
EXAMPLE 6 
The procedure of Example 1 is repeated, except that 6.3 parts of spermaceti 
are substituted for the lanolin. The resultant emulsion exhibits good 
stability at room temperature and exhibits excellent release properties 
when applied to the bladder or the inside of a green tire carcass and then 
molded into a tire. 
EXAMPLE 7 
The procedure of Example 1 is repeated, except that 6.3 parts of a 
polyethylene glycol having a melting point below 80.degree. C. are added 
to the composition. The resultant emulsion exhibits good lubricity and 
good stability at room temperature, but the number of releases is about 10 
when applied to the bladder in molding tires. 
EXAMPLE 8 
The procedure of Example 1 is repeated, except that 450 parts of a 
hydroxyl-terminated organopolysiloxane gum having a plasticity value of 
about 120 are substituted for the hydroxylterminated organopolysiloxane 
gum having a plasticity value of 50. The resultant emulsion begins to 
"break" after a period of time. 
EXAMPLE 9 
The procedure of Example 1 is repeated, except that 93.3 parts of sodium 
carboxymethylcellulose are substituted for the Carbopol. The resultant 
emulsion exhibits good storage stability and excellent release properties 
when applied to the bladder or the inside of a green tire carcass and then 
molded to form a tire.