US2874863A

US2874863A - Controlled torque gasket compositions

Info

Publication number: US2874863A
Application number: US649633A
Authority: US
Inventors: Harold W Unger; Donald H Zipper
Original assignee: White Cap Co
Current assignee: White Cap Co
Priority date: 1957-04-01
Filing date: 1957-04-01
Publication date: 1959-02-24
Anticipated expiration: 1976-02-24
Also published as: DE1066686B; GB844400A; FR1196944A

Description

Feb. 24, 1959 -H. w. UNGER ETAL CONTROLLED TORQUE GASKET COMPOSITIONS Filed April 1, 1957 5 M 0 i 1;... Z U n M v United States Patent CONTROLLED TORQUE GASKET COMPOSITIONS Harold W. Unger, Mount Prospect, and Donald H. Zipper, Elmhurst, Ill., assignors to White Cap Company, Chicago, 111., a corporation of Delaware Application April 1, 1957, Serial No. 649,633

35 Claims. (Cl. 215-40) The present invention relates generally to improved gasket compositions in the form of permanent rubbery gels which, forexample, may be derived or produced from plastisols, the improved compositions being particularly adapted for use in rotatable caps to provide the same with controlled opening torques following application to glass containers in sealed relation therewith. More specifically, the invention is directed to the provision of a lubricating coating or film on the sealing surface of the gasket or lining material on the interiors of closure caps, which coating or film serves to reduce the coeflicient of friction between the gasket and that part of the container with which it is in contact. The lubricating function of such coating controls the magnitude of cap-removing torque required to loosen and remove thecap from the container to prevent seizure between the gasket material and the finish of the container following application of the cap to the container in known automatic capping machines such as that disclosed in a copending application Serial No. 549,987, filed November 30, 1955.

A lug-type rotatable closure cap with which the improved gasket material of the present invention is adapted for use is disclosed, for example, in a copending application Serial No. 520,881, filed July 8, 1955. This type of cap is formed from a metal shell having a top panel portion and a depending skirt portion, the outer margin of the inner surface of the top panel portion being provided with gasket material into which is pressed the top rim or edge of a container, such as a glass jar or bottle, when the cap is forced down into sealed relation therewith. The depending skirt portion of the cap is provided with inwardly directed lugs which are slidingly moved along glass threads or lugs formed in the outer surface of the container inwardly of the top edge thereof. The cap is turned on in a known manner and the advancing of the top panel of the cap toward the top edge of the container brings the gasket into intimate sealing relation with the top edge of the container to seal the same. In sealing glass containers the contents placed in the containers are frequently at elevated temperatures and the cap including its gasket is also frequently heated when applied to the container.

In addition to the lug-type caps described, other rotatable caps such as the internally threaded type may be provided with a controlled opening torque by means of the improvements to be described. Also, the gasket material may be used in the form of annular side-seal and.

,sealing action with containers. Copolymeric gasket materials include vinyl chloride-vinylidene chloride resins and vinyl chloridevinylacetate resins. Sealing compositions formed from these copolymers may be prepared by following several different procedures which are well known.

Extruded, cast and calendered compositions as well as mixtures commonly referred to as plastisols and organosols may be applied to the inner surfaces of caps for container sealing purposes. While several different forms of vinyl chloride resin base compositions may be improved by following the teachings of the present invention, the plastisol compositions are specifically dealt with in the following description due to the adaptability of such compositions to be applied to caps using the flowedin technique.

The plastisol gasket materials in use at the present time are made from a paste-forming, resin-plasticizer mixture which preferably and usually contains a filler. The mixture, upon fluxing at elevated temperatures after being applied to the inner surface of a cap shell, forms a permanent gel which becomes elastic and rubbery upon subsequent cooling. Upon the reheating of the plastisol gasket material, during a sealing operation requiring heat, when the cap carrying the same is brought into seating contact with a filled heated jar, the plastisol loses its elasticity until subsequently cooled at which time the original elasticity is quickly regained. Still further, a plastisol of this type is known to relax under pressure even when cold. These two inherent physical phenomena of plastisol gasket materials combine to make it commercially difficult if not impractical to apply caps having gaskets formed of ordinary plastisols to jars without .either applying the caps too loosely so that they become leakers or too tightly so that they freeze" on and require excessive opening torque to remove.

In order to maintain a seal, hermetic or otherwise, there should be sufficient friction to prevent a rotatable closure cap from turning or loosening in ordinary handling. Since there is relatively little friction between the metal lugs or threads and glass lugs or threads, the ability of a rotatable cap to stay on a glass container is due primarily to the friction between the gasket compound and the glass. Therefore, while there must be sufficient initial friction to prevent a cap from being loosened in ordinary handling or from backing off in the case of inclined lugs on the container, the friction must not increase with time by seizing to such an extent that the cap is difiicult to remove.

It has been found that the friction caused by seizing developed between known plastisol gasket material and the glass finish increases substantially upon standing.

. times as high as 80 inch-pounds. Longer .times have been known to require inch-pounds or more. As such tests revealed, the values of the opening torque subsequent to the capping operation were found to be extremely variable'and difficult, if not impossible, to control. For use by the average consumer, the ideal opening torque for a rot'atablecap should fall within a range well below 100 inch-pounds regardless of the time elapsed following the capping operation. The size of the cap will affect the magnitude of required opening torque and with the use of larger size caps the control of opening torque becomes more important. ciples of the present invention, various formulations, given later, have been made and flowed into large caps (77 mm. dia.) which were sealed onto jars. Maximum opening torque requirements of these large caps even over extended periods of storage time were found to be substantially less than 100 inch-pounds. This approaches the ideal range even though a large size cap was used. This range of opening torque is such that there is sufficient adhesioh to prevent the cap from backing off out.

Using the .prinof sealing engagement with the container in the case of inclined lugs and from becoming accidentally loosened in handling, and yet the adhesion may be readily overcome without difficulty upon intended removal of the cap from .the container.

Plastisol gasket materials .fformed from resins .such as polyvinyl chloride exhibit good initial elasticity when cold but quickly lose this elasticity under constant deformation whilesharplylosing thesame when heated to around '190 F. Elasticity is sharply regained upon cooling and the original properties reassert themselves. Whilethe .compressive force exerted against the gasket material Will cause the same to relax even while cooling, the degree of relaxation is not sufficient to counterbalance the increased adhesiveness caused by the elasticity being quickly regained. Consequently, the compressive force developed by the regaining of elasticity greatly exceeds the reduction .in compressive force caused by relaxation during the cooling of the plastisol gasket material.

TWithfincreased compressive force between the plastisol gasket and the glass finish, seizure or friction increases correspondingly. Thus, upon standing, the torque necessary to remove a cap from a container increases proportionally with increased seizure or adhesiveness. This is true also whenvthe cap is not heated, but the opening torques do not reach quite as high values and it takes more time-for the highest value to be obtained. During a hot capping operation the plastisol, being in a heated condition, exhibits minimum adhesiveness. Consequently, it is necessary to rely on the friction developed by the torque applied in turning the cap down on the container. This torque must be adequate in magnitude to establish sufficient friction between the cap and container to prevent loosening or movement of the cap following the capping operation until sufiicient adhesiveness develops betweenthe plastisol and the container by the regaining of elasticity upon cooling. This is not a problem in cold sealing, but controlling the tightening torque is very important. has been found impractical, if not impossible, when known plastisol compositions are used, to control the friction developed between the gasket and the container due to the sharp regaining of elasticity of the plastisol upon cooling. Until recently, there has been no known procedure to follow, or published formulations to use, to produce capped containers, the caps of which may be removed from the containers by the application of open ing torques falling within a specified, relatively limited and desirable range. It is during the first minute or so following the heated capping operation that adhesion is begun. In the case of cold capping, the adhesion develops more slowly.

It is an object of the present invention to provide improved gasket or sealing compositions which, when applied to the interior'ofa closure cap in accordance with known practices and the cap is thereafter applied to a container by commercial automatic capping apparatus, provide a controlled frictional seal between the gasket material and the container which may be overcome by the use of a torque falling within a predetermined relatively limited and acceptable range at any time following the capping operation regardless of the compressive forces on the gasket against the sealing surface that may result.

Another object is to provide an improved sealing gasket composition such as the plastisol or organosol type which exhibits controlled seizure upon use in a known manner in sealing a container, the friction developed between the cap and .the containerbeing capable of predetermination to allow the cap to .be removed at any time subsequent to the capping operation upon the application of an opening torque which falls within a relatively limited and useful range, the controlled opening torque resulting from the presence of .alubricating interface between .the gasket :composition .and .the container, which interface As previously described, it

' gara es is capable of controlling the magnitude of frictional resistance developed between the cap and the container while allowing the development of frictional resistance of sufiicient magnitude to establish and maintain efficient sealing action between the cap and container.

A further object is to provide improved gasket compositions of the type formed from a paste-forming resinplasticizer mixture containing discrete particles of filler material, the mixture being improved by the inclusion of lubricant which will be present on the surface of the resulting rubbery gel upon fiuxing and cooling of the mixture or transforming of the mixture into a'permanent rubbery gel by extrusion or the like, the lubricant being either lecithin or silicone fluid or combinations of lecithin, silicone fluid and paraflin, the lubricating agents or combinations of the same providing a controlled friction coating on the sealing surface of the gelled gasket composition to allow controlled torque removal of a cap carrying the composition following application of the same in sealed relation with a glass container.

Another object of the invention is the provision of rotatable closure caps having gaskets or sealing linings formed of the compositions mentioned in the foregoing objects.

Other objects not specifically set forth will become apparent from the following detailed description of the present invention made in conjunction with the drawing wherein:

Fig. 1 is a side elevational view of a glass container hermetically sealed with a closure cap of the type par ticularly adapted for use in practicing the present inventio-n;

Fig. 2 is a top plan view of the closure capflshown in Fig. 1;

Fig. 3 is .a bottom plan view of theclosure cap shown in Fig. 1;

Fig. 4 is a fragmentary sectional view of the closure cap on enlarged scale taken along line 44 of Fig. 2; and

Fig. 5 is a view similar to Fig. 4 illustrating container sealing application of the closure cap.

In Fig. 1 a glass container 10, such as an ordinary jelly glass, is sealed with a closure cap 11. The closure cap 11 is of the type previously described and as partic ularly shown in Figs. 24'consists of a cap body or shell having a top panel portion 12 and a depending skirt portion 1?. The cap body or shell is stamped out from suitable coated tin plate, although other materials may be used. Generally, the tin plate is enameled on the exterior and the interior is enameled or coated with a known lacquer-formulation so as to form a protective coating and give the interior attractiveness in appearance. The bottom edge of the depending skirt 13 is normally. rolled to reinforce this edge while giving the same a neat appearance and removing the sharp edge which is left' when the cap shell or body is stamped out. The lug-type closure cap illustrated is provided with a plurality of lugs- 14 for cooperative cap clamping engagement with circumferentially spacerd glass lugs 15 integrally formed.

on the exterior of the neck portion of the glass container 16) as shown in Fig.5.

The top panel 12 of the cap 11 is provided with a central depressed portion 16 which defines a continuous annular shoulder 17 inwardly of the skirt 13. The

shoulder 17 and skirt 13 thus define therebetween an an the cap 1 to the container 10 isshown in Fig. SWith the top edgeof the neckof the container 10 (which is generally referred to as the sealing 'finish) being embedded in'the gasket .19. Removal of the cap 11 from the container 10 requires the -application'of a torque and,

as previously described, the present invention is directed to the controlling of the opening torque within a specified range to permit substantial uniformity in opening torques required for caps of the type described.

A plastisol of the type described above is in the form of a congealed paste-forming, resin-plasticizer mixture containing, in uniform distribution, finely divided discrete particles of a filler material and finely divided discrete particles of a paste-forming, synthetic resin suspended in a non-volatile plasticizer for the resin, the resin being paste-forming with the plasticizer at a temperature below the fiuxing temperature of the resinplasticizer component and soluble in the plasticizer upon heating to the fluxing temperature. This type of plastisol forms at the resin-plasticizer fluxing temperature a permanent gel which becomes elastic and rubbery upon subsequent cooling.

It has been found that by adding to the foregoing conventional mixture of ingredients forming a plastisol certain lubricant-forming ingredients, upon the formation of the gel following fiuxing of the mixture, a lubricant will be present on the sealing surface thereof to provide an outer coating capable of lubricating the frictional seal between the gasket and a glass finish or other sealing surface. The extent of lubrication is such that the necessary tack or adhesiveness capable of resisting loosening or dislodgement of the applied cap following the capping operation is present while at the same time the frictional forces developed between the gasket and the sealed surface can be readily overcome upon the application of an opening torque of relatively low magnitude.

As shown in Figs. 4 and 5, the lubricant is in the form of a surface coating 21 present on the sealing surface of the gasket 19 for direct contact with the sealing finish of the container 10. The lubricant forms an interface which remains between the plastisol and container subsequent to the full recovery of the elasticity and accompanying compressive force of the plastisol gasket. In order to remove the cap from the container, it is necessary merely to apply a torque adequate to effect internal shearing in the lubricant interface and overcome the friction existing between the lugs of the cap and the threads of the container. Thus, while the friction existing between the lugs of the cap and the threads of the container is controlled to a predetermined extent by the capping operation, the friction existing between the plastisol gasket material and the glass finish is controlled by the type of lubricant-forming ingredients incorporated in the gasket material and the extent to which the lubricant is present on the sealing surface of the gasket material. The opening torque is the force necessary to overcome the sum of these predetermined frictional resistances and may be readily predicted and controlled to fall within an ideal opening-torque application range.

-The preferred lubricants and mixtures of lubricants constituting the essence of the pres-cut invention include the use of lecithin, silicone fluid and a sealing wax such as parafim. The preferred combination of lubricants includes the use of all three in admixed form. However, desirable results can be obtained by using lecithin alone, a silicone fluid alone, as well as mixtures of lecithin and silicone fluid, lecithin and paraffin, and silicone fluid and parafiin. The lubricants or lubricant-forming ingredients referred to above not only exhibit the desirable property of controlling friction but, still further, meet many other requirements of a material used on food containers. They are, for example, non-thermosetting, non-toxic and nondrying.

In forming a plastisol gasket composition, a polyvinyl chloride resin is preferably used; however, this resin may be readily modified with a material such as polyvinylidene chloride or polyvinylacetate. Polyvinyl chloride resin in combination with a copolymer resin of vinyl chloride and vinylidene chloride forms an effective plastisol material as will subsequently be described. The resin forms a paste with the plasticizer and is added thereto in the form of finely divided discrete particles which become uniformly distributed in suspension in the plasticizer. Any suitable plasticizer may be utilized as long as it is non-volatile. Plasticizers such as Paraplex G-62 (a polyester epoxide made by Rohm and Haas, Philadelphia, Pennsylvania) and Citroflex A-4 (an acetyltributyl citrate made by Chas. Pfizer and Company, Brooklyn, New York) have been found suitable. A filler material may be added in the form of finely divided discrete particles which are uniformly distributed throughout the mixture. A filler material such as barytes has been found to impart desirable flow properties to the mixture. The resin used should be substantially insoluble in the particular plasticizer at atmospheric temperatures while being soluble in the plasticizer at elevated fluxing temperatures.

On the basis of parts by weight of resin, the plasticizer used will preferably fall within the range of 50 to 250 parts by weight. The filler material is preferably added in quantities within the range of 0 to 250 parts by weight. To the resin plasticizer mixture, which is formulated in any known manner, is added a quantity of lubricant the amounts of which will vary depending upon the particular lubricant or mixture of lubricants used as well as the amount of resin, filler or plasticizer present. In connection with the use of lecithin of a commercial grade and form, it has been found that about 0.25% by weight of the plastisol composition and greater yields desirable result. The upper level of lecithin added to the plastisol composition will depend upon the extent to which certain physical properties of the plastisol can be sacrificed. With the use of excessive amounts of a lubricant or lubricating mixture, the modulus, hardness and tensile strength of the plastisol may be adversely affected. Consequently, the. upper limit to which lubricant may be present in the composition will depend upon its untoward effect on the physical properties of the finished gasket material.

In connection with the useof silicone fluid it has been found that quantities of from about 0.5% to 15% by Weight of the composition are preferably used. Quantities of from about 1% to 10% of paraffin based on the total weight of the composition are preferably used. Amounts of these lubricants including lecithin falling within the ranges specified provide a well balanced lubrication system in the plastisol composition whether or not certain of the particular lubricants, such as lecithin and silicone fluid, are used separately or any combinations of the same are used in admixture.

The preferred silicone fluid is that having a viscosity of approximately 350 centistokes although other viscosities capable of providing the desired lubricating action can be incorporated in the plastisol composition. Commercial grades and forms of lecithin have been found to be entirely suitable. While the wax lubricating ingredient is preferably parafiin, other waxy ingredients can be used. Examples of such ingredients are longchain fatty acids such as stearic acid and myristic acid, diglycol stearate, beeswax, polyamide wax, candelilla wax, octadecenylamine, polyethylene glycol, japan wax, long-chain alcohol such as stearyl and cetyl alcohols, and blended parafiins.

Upon complete mixing of the resin-plasticizer mixture including the lubricant, the paste-like composition formed is readily adapted for application to the interior of a closure cap shell to form an annular gasket or sealing lining. The particular manner in which such a pastelike mixture is applied to the cap is known and discussed, for example, in said copending application. The mixture exhibits adequate tackiness to adhere to the enameled surface of the cap and be retained in position during subsequent fiuxing procedures at which time the mixture is transformed into a permanent rubbery gel. The fluxing of the resin-plasticizer mixture is completed when the plastisol reaches a temperature of approximately aortas-s 350 'F., and lubricant 'will be present on'the surface of the gasket ring or lining carried on the cap and re mains thereon following subsequent cooling of the finished 'gasket and cap. The surface coating or film of lubricant being viscous remains on the surface of the gasket material and storage over protracted periods of time will not result in noticeably reduced lubricating efficiency when the cap is ultimately used in sealing a container.

The following examples illustrate typical plastisol compositions to which various lubricants and mixtures of lubricants of the type disclosed have been added in accordance with the principles of the present invention. The particular ingredients and amounts used as well as conditions and procedures described herein are merely illustrative and are not intended to limit the scope of the present invention.

A basic plastisol composition was used in a series of tests using different lubricants and combinations thereof wherein 77 mm. rotatable caps having four lugs were provided with the various plastisol gaskets and applied to similar glass jars having helical lugs. In each instance calcium chloride was added to the jar to dry out any moisture therein which might affect the particular test and the test cap was applied to the jar under vacuum by a known type of capping machine. The capped containers were then allowed to stand for certain time intervals and the opening torques necessary to remove the caps from the jars were measured in inch-pounds.

Basic recipe In the foregoing basic recipe, the Geon 121 is a commercial polyvinyl chloride resin manufactured by Goodrich Chemical Co., Cleveland, Ohio. The (icon 202 is a copolymer resin containing approximately 94% vinyl chloride and 6% vinylidene chloride, this resin being available from the same source as the polyvinyl chloride. The Ferro 707X is a stabilizer soap made by Ferro Chemical Co., Bedford, Ohio. While this particular stabilizer is preferred, calcium ricinoleate may be used. The Titanox RA is a titanium dioxide pigment manufactured by Titanium Pigment Corporation, New York, .New York.

The following table sets forth the opening torques required in removing the various caps applied to the containers as previously described. In each instance the basic recipe listed above was used and the parts by weight of L (lecithin), S (silicone fluid) and P (paraffin) used in each formulation is set forth.

Opening torques (in.-lb.)

Opening Age in P,4.4 P-A S 2.5 P-4.4 Days 8-2.5 L-LO L1.0 Ll.0 S -2.5 8-2.5

opening torques in inch-pounds were below '100 inchpounds and substantially .below'with those formulations including lecithin. Without the 'use of a lubricant or mixture of lubricants in the basic recipe, the opening torque necessary to remove a cap from a container would be over inchpounds. Consequently, the results ob tained indicate a significant improvement in the reduction in opening torque while maintaining efficient sealing action between the cap and container. The parafiin used in the test was of a commercial grade available from Standard Oil of Indiana and the silicone fluid was a 350 centistoke compound manufactured by Dow Corning, Midland, Michigan. The lecithin was a commercial grade obtained from Glidden Corporation, Soya Division, Chicago, Illinois.

It has been found that in using silicone fluid alone as a lubricant, substantially larger quantities thereof than of lecithin alone are necessary in order to provide comparable lubricating action. The use of paraiiin alone is not considered desirable in that, upon blooming of the wax to the surface of the gasketing material and upon application of the cap to the jar, the paraffin sets up as a solid at the interface which requires excessive torque for shearing in order to remove the cap from the jar. However, the inclusion of parafiin provides for easier cap application onto the container. Consequently, the preferred lubricating mixture includes an amount of paraflin combined With lecithin and silicone fluid.

During extended testing of the various plastisol compositions of the present invention, it has been foundthat it is desirable to increase the amount of lubricants when the plasticizer-resin and/or plasticizer filler ratios are increased. Thus, it is desirable to maintain approximately the same percentage by weight of lubricant in the over-all plastisol composition. in general, an increase in plasticizer and/ or filler requires a relative increase in lubricant.

While the use of the improved compositions has been described primarily in connection with lug-type caps, it should be understood that the controlled opening torques obtainable therewith are also useful with other forms of caps, such as screw caps. I

Obviously, many modifications and variations of the invention as hereinbefore set'forth may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

We claim:

l. A gasket forming composition comprising a vinyl chloride base resin and quantities of lecithin and silicone fluid, the latter ingredients being present in sufficient amounts so as to be present on the surface of a gasket formed from said composition and provide lubrication thereto.

2. A gasket forming composition comprising a vinyl chloride base resin and quantities of lecithin, silicone fluid and parafiin, the latter ingredients being present in sufficient amounts so as to be present on the surface of a gasket formed from said composition and provide lubrication thereto.

3. A gasket forming composition comprising a vinyl chloride base resin and quantities of silicone fluid and paraiiin, the latter ingredients being present in sufficient amounts so as to be present on the surface of a gasket formed froin'said composition and provide lubrication thereto.

4. A gasket forming composition comprising a vinyl chloride base resin and quantities of lecithin and paraffin, the latter ingredients being present in sufficient amounts so as to be present on the surface of a gasket formed from said composition and provide lubrication thereto.

5. A gasket forming'composition comprising a vinyl chloride base resin and a quantity of silicone fluid, the latter ingredientbeing present in a sufiicient amount'so as to be present on the surface of a gasket formed from said composition and provide lubrication thereto.

6. A gasketforming composition comprising a vinyl chloride base resin and quantities of lecithin and silicone fluid, the lecithin being present in an amount not less than about 0.25 by weight and the silicone fluid being present in an amount of from about 0.5% to 15% by weight so as to be present on the surface of a gasket formed from said composition and provide lubrication thereto.

7. A gasket forming composition comprising a vinyl chloride base resin and quantities of lecithin and parafiin, the lecithin being present in an amount not less than about 0.25% by weight and the paraflin being present in an amount of from about 1% to 10% by weight so as to be present on the surface of a gasket formed from said composition and provide lubrication thereto.

8. A gasket forming composition comprising a vinyl chloride base resin and quantities of lecithin, silicone fluid and paraffin, the lecithin being present in an amount of not less than about 0.25% by weight, the silicone fluid being present in an amount of from about 0.5% to by weight, and the paraflin being present in an amount of from about 1% to 10% by weight, these latter ingredients being present on the surface of a gasket formed from said composition in sufficient amounts to provide lubrication thereto.

9. A gasket forming composition comprising a vinyl chloride base resin and a quantity of silicone fluid, the latter ingredient being present in an amount of from about 0.5 to 15 by weight so as to be present on the surface of a gasket formed from said composition and provide lubrication thereto.

10. A gasket forming composition comprising a vinyl chloride base resin and quantities of silicone fluid and paraflin, the silicone fluid being present in an amount of from about 0.5 to 15 by weight and the parafiin being present in an amount of from about 1% to 10% by weight so as to be present on the surface of a gasket formed from said composition and provide lubrication thereto.

11. A gasket forming composition comprising a vinyl chloride base resin and approximately 1 part by weight of lecithin, approximately 2.5 parts by weight of silicone fluid, and approximately 4.4 parts by weight of paraffin, said lecithin, silicone fluid and paraffin being present on the surface of a gasket formed from said composition in sufficient amounts to provide lubrication thereto.

12. A rotatable cap adapted for application to a container in sealing relation therewith, said cap having a vinyl chloride base gasket material carried thereby the outer surface of which is adapted for frictional sealing engagement with a surface of said container, said outer surface being provided with a lubricant coating comprising lecithin and silicone fluid.

13. A rotatable cap adapted for application to a container in sealing relation therewith, said cap having a vinyl chloride base gasket material carried thereby the outer surface of which is adapted for frictional sealing engagement with a surface of said container, said outer surface being provided with a lubricant coating comprising lecithin, silicone fluid and paraflin.

14. A rotatable cap adapted for application to a container in sealing relation therewith, said cap having a vinyl chloride base gasket material carried thereby the outer surface of which is adapted for frictional sealing engage ment with a surface of said container, said outer surface being provided with a lubricant coating comprising lecithin and paraffin.

15. A rotatable cap adapted for application to a container in sealing relation therewith, said cap having a vinyl chloride base gasket material carried thereby the outer surface of which is adapted for frictional sealing engagement with a surface of said container, said outer surface being provided with a lubricant coating of silicone fluid.

16. A rotatable cap adapted for application to a container in sealing relation therewith, said cap having a vinyl chloride base gasket material carried thereby the outer surface of which is adapted for frictional sealing engagement with a surface of said container, said outer surface being provided with a lubricant coating comprising silicone fluid and paraffin.

17. A closure member adapted for application to a container in sealing relation therewith, said member having applied to an inner surface thereof a sealing material formed of vinyl chloride base resin and relatively small quantities of lecithin and silicone fluid sufficient for lubrication being present on the surface of said sealing material which is arranged for frictional sealing engagement with a surface of said container.

18. A closure member adapted for turn-on application to a container in sealing relation therewith, said member having applied to an inner surface thereof a sealing material formed of vinyl chloride base resin, a quantity of lecithin of not less than about 0.25 by weight, and a quantity of silicone fluid of from about 0.5 to 10% by weight, sufficient of said lecithin and silicone fluid for lubrication being present on the surface of said sealing material which is arranged for frictional sealing engagement with a surface of said container.

19. A closure member adapted for application to a container in sealing relation therewith, said member having applied to an inner surface thereof a sealing material formed of vinyl chloride base resin and relatively small quantities of lecithin and paraffin sufficient to be present on the surface of said sealing material which is arranged for frictional sealing engagement with a surface of said container.

20. A closure member adapted for application to a container in sealing relation therewith, said member having applied to an inner surface thereof a sealing material formed of vinyl chloride base resin, a quantity of lecithin of not less than about 0.25% by weight, and a quantity of paramn of from about 1% to 10% by weight, sufficient lecithin and paraflin for lubrication being present on the surface of said sealing material which is arranged for frictional sealing engagement with a surface of said container.

21. A closure member adapted for application to a container in sealing relation therewith, said member having applied to an inner surface thereof a sealing material formed of vinyl chloride base resin and relatively small quantities of lecithin, silicone fluid and paraffin being present on the surface of said sealing material which is arranged for frictional sealing engagement with a surface of said container.

22. A closure member adapted for application to a container in sealing relation therewith, said member having applied to an inner surface thereof a sealing material formed of vinyl chloride base resin, a quantity of lecithin of not less than about 0.25 by weight, a quantity of silicone fluid of from about 0.5% to 10% by weight, and a quantity of paraffin of from about 1% to 10% by weight, suflicient lecithin, silicone fluid and paraflin for lubrication being present on the surface of said sealing material which is arranged for frictional sealing engagement with a surface of said container.

23. A closure member adapted for application to a container in sealing relation therewith, said member having applied to an inner surface thereof a sealing material formed of vinyl chloride base resin and a relatively small quantity of silicone fluid being present on the surface thereof which is arranged for frictional sealing engagement with a surface of said container.

24. A closure member adapted for application to a container in sealing relation therewith, said member having applied to an inner surface thereof a sealing material formed of vinyl chloride base resin and a quantity of silicone fluid of from about 0.5 to 15% by weight, suflicient silicone fluid for lubrication being present on the surface of said sealing material which is arranged of said sealing material which is arranged for frictional 7.

sealing engagement with a surface of said container.

26. A closure member adapted for application to a container in sealing relation therewith, said member having applied to an inner surface thereof a sealing material formed of vinyl chloride base resin, a quantity of silicone fluid of from about 0.5% to 10% by Weight, and a quantity of paraffin of from about 1% to 10% by Weight, suflicient silicone fluid and parafiin for lubrication being present on the surface of said sealing material which is arranged for frictional sealing engagement with a surface of said container. 7

27. A gasket forming composition comprising a vinyl chloride base resin and suflicient quantities of lecithin and parafiin so as to be present on the surface of a gasket formed from said composition and provide lubrication thereto, the paraffin content being approximately 2% by weight.

28. A gasket forming composition comprising a vinyl chloride base resin and suflicient quantities of lecithin and parafiln so as to be present on the surface of a gasket formed from said composition and provide lubrication thereto, the lecithin content being approximately 0.5% by weight.

29. A gasket forming composition comprising a vinyl. chloride base resin and quantities of lecithin and paraffin, the lecithin being present at about 0.5% by weight and the par-aflin being present at about 2% by Weight so as to bepresent on the surface of a gasket formed from said composition and provide lubrication thereto.

30. A rotatable cap adapted for application to a container in sealing relation therewith, said cap having a vinyl chloride base gasket material carried thereby the outer surface of which is adapted for frictional sealing engagement with a surface of said container, said outer surface being provided with a lubricant coating comprising parafiin and about 0.5% by weight lecithin.

31. A rotatable cap adapted for application to a container in sealing relation therewith, said cap having a vinyl chloride base gasket material carried thereby the gardens l2 outer surface of which is adapted for frictional sealing engagement with a surface of said container, said outer surface being provided with a lubricant coating comprising lecithin and about 2% by weight paraflin.

32. A rotatable cap adapted for application to a container in sealing relation therewith, said cap having a vinyl chloride base gasket material carried thereby, the outer surface of which is adapted for frictional sealing engagement with a surface of said container, said outer surface being provided with a lubricant coating comprising about 0.5% by weight lecithin and about 2% 'by weight paraffin.

33. A closure member adapted for application to a container in sealing relation therewith, said member 'having applied to an inner surface thereof a sealing material formed of vinyl chloride base resin and relatively small quantities of lecithin and paraffin sufficient to be present on the surface of said material which is arranged for frictional sealing engagement with a surface of said container, the quantity of lecithin being about 0.5% by weight.

34. A closure member adapted for application to a container in scaling relation therewith, said member having applied to an inner surface thereof a sealing material formed of vinyl chloride base resin and relatively small quantities of lecithin and paraffin sufficient to be present on the surface of said sealing material which is arranged for frictional sealing engagement with a surface of said container, the quantity of parafiin being about 2% by weight.

35. A closure member adapted for application to -a container in sealing engagement therewith, said member having applied to an inner surface thereof a scaling material formed of vinyl chloride base resin and relatively small quantities of lecithin and paraflin' sufficient to be present along the surface of said sealing material which is arranged for frictional sealing engagement with a surface of said container, the quantity of lecithin being about 0.5 by weight and the quantity of paraffin being about 2% by weight.

References Cited in the file of this patent UNITED STATES PATENTS 2,489,407 Foye Nov. 29, 1949 2,752,059 j Schneider June 26, 1956 FOREIGN PATENTS 566,048 Great Britain Dec. 11, 1944 669,600 Great Britain Apr. 2, 1952