US 3165227 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Jan. 12, 1965 P. L. cRowELl. ETAL 3,165,227
PACKAGE AND COMPOSITIN Filed Nov. 7, 1963 INVENTORSv Mam #fifi itl k f United States Patent O 3,165,227 PACKAGE ANB CMPSITIQN Philip L. Crowell, William C. Harris, and Erland L Muoio, Racine, Wis., assignors to S. C. .lohnson l Son, Inc., Racine, Wis.
Filed Nov.. 7, 1963, Ser. No. 322,3.36 Claims. (Cl. 22h- 42) This invention relates to an improved package and more particularly to the type of package which is required to be sealed. While the package of our invention is capable of a wide variety of uses, it is particularly useful with organc solvent base compositions such as polishing compositions.
Packages which are used with certain organic solvent base compositions and other compositions having volatile constituents must be so designed as to maintain a substantially airtight seal. The package must provide a seal which will substantially inhibit leakage of the volatile contents while also substantially preventing the admission of air into the package in order to insure optimum shelf life and avoid deterioration of the contents.
Recent advances in marketing techniques and package designing have emphasized using various plastic substances in fabricating certain consumer line packages, particularly in the iield of polishing compositions and the like. These plastic packages can often be fabricated in a broad spectrum of colors and designs more readily than their metal counterparts. In addition, plastic packages have other desirable attributes including simplicity of construction, requiring the use of readily available and inexpensive components that may be formed by simple mass production techniques; durability of construction to provide for a relatively long usable life and to withstand rough usage and handling and reusability so that purchasers may reutilize the package to preserve partially used package contents.
Recent advances in various cleaning and polishing compositions and particularly organic solvent based compositions have resulted in the use of relatively volatile reactive solvents in high concentrations. Such compositions present packaging problems in that the solvents either attack various plastic substances causing swelling and distortion and/ or penetrate the package Wall resulting in weight loss and product deterioration with abbreviated shelf life. In addition, these solvents produce pressure build up under elevated temperatures causing hermetically sealed packages to swell and produce wall bubbles. Under certain conditions, hermetically sealed packages have been known to explode.
The present invention provides a package suitable for various solvent base compositions having a substantially airtight seal resulting in prolonged shelf life of the product while also resisting attack and/or penetration of the solvent. In addition, the instant package is responsive to the contents therein and will permit the escape of gases under certain conditions in order to avoid the dangers attendant to pressure build up such as explosion. Moreover, the package provides this type of seal over the life of the product including intermittent opening of the package. v
This capacity of:
(l) Resisting solvent attack,
(2) Being impervious to gases,
(3) Providing a substantially airtight seal which is responsive to changes in pressure build up of the contents and being capable of subsequently resuming a substantially airtight seal, and
(4) Maintaining a substantially air tight seal after intermittent openings of the package,
to provide the contents thereof with a prolonged shelf life is herein defined as a dynamic seal.
i' Patented dan. l2, 1955 Resistance to solvent attack is defined herein as the capacity of a plastic substance to remain substantially inert towards various organic solvents under storage conditions for substantial periods of time. In particular, resistance to naphtha solvent for periods of from about 18 to about 24 months is desired.
lmperviousness to gases is defined herein as the capacity to substantially retard the permeation of gases through various thicknesses of certain plastic substances. For example, the permeability of naphtha vapor through a preferred polyvinylchloride substance ranges from about 0.150 to about 1.250 gin/24 hrz/square meter for sheets having a thickness of about 0.024 to about 0.0613 inch.
Although the dynamically sealed package of the present invention can be used to package a wide variety of substances, it is particularly adapted to packaging certain compositions containing organic solvents such as naphtha base solvents. Naphtha base solvents are herein-defined as those organic solvents wherein at least 50 percent by weight of the solvent is naphtha. It has been found that compositions containing up to about 40 percent by weight naphtha solvents can be stored satisfactorily in the instant package having the herein ldescribed dynamic seal. For example, after prolonged storage periods of from about 18 to about 24 months with intermittent opening under various changes in storage temperature and corresponding changes in internal pressure of up to about 20 p.s.i.g. certain polishing compositions containing up to about 40 percent by weight naphtha base solvents have been found to perform satisfactorily. In contrast, similar compositions stored in packages of a similar design fabricated from various polyethylene and polypropylene plastics were found to have abbreviated shelf life, i.e., substantial weight loss, poor polishing performance, solidifying and the like. In addition, certain of these packages exhibited swelling and were reactive with the contents. The improvement in shelf life of certain polishing compositions using the dynamically sealed package of the present invention ranged from about to about 150 percent over packages of a similar design which were not capable of providing a dynamic seal as defined above.
In addition to providing optimum shelf life, a suitable package for various organic solvent base compositions must be responsive to changes in internal pressure resulting from volatilization of organic solvents.
Under certain storage conditions, such as increased temperatures, the extent of volatilization in polishing compositions approaches dangerous proportions necessitating exhausting some of the gases to avoid rupturing and/ or explosion of the package. If the package is hermetically sealed under these conditions without a venting means, it represents a significant storage risk. Accordingly, an optimum package would provide a means of venting the excess gas at a given pressure build up and subsequently resume a sealed condition when the excess gas has been discharged. The dynamically sealed package of the present invention provides a package which will withstand increases in internal pressure up to about 20 p.s.i.g. At internal pressures of about 20 p.s.i.g., the lid and container of the package distort sufficiently to provide venting for the captive gaseous components. The package is sufficiently resilient so that generally this venting can be obtained without permanent distortion of the package and the lid and container subsequently unite to provide a dynamically sealed package. However, if there is a rapid increase in internal pressure due to an extreme increase in external temperature, such as a tire, the lid will be blown off of the container and the gases discharged rather than produce an explosion. In a particular embodiment of the invention, a lid designed as described hereinafter arenas? Y d ameter of about 41/2 inches was found to withstand an internal absolute pressure of about 266.4 pounds at room temperature before lifting from the container. Internal pressures from about 200 to about 300 pounds absolute at room temperature can vbe tolerated by a lid of this size.
Various .resiiient plastic substances which areimpervious to volatile organic solvents and which are substantiaily inert lto said solvents can be used to fabricate the components of the package. In a preferred embodiment of the invention, the package is fabricated from polyvinylchlorda-nlyon -poly carbonate polymersy yand certain uorinated polymers such as Teflon. ln a particularly preferredembodiment of the invention, the package is extruded from a rigid polyvinylchloride substance having:
(1) A specific gravity between about 1.2 and about 1.5
and, preferably about 1.36;
(2) A thermal deliection temperature under load of about 66 p.s.i. between about 150 and about 180 F. and preferably about 169 F.; and,
(3) An Izod impact strength in -a 0.010 inch notch of 1A; inch piece at about 73 F. of about 15 foot pounds/ inch, and
(4) Naphtha vapor permeability through a sheet thickness of about 0.024 inch of between about 0.150 and about 0.180 gm./ 24 hr./ square meter at a surface temperature of 73 VF. with a 50 percent relative humidity and circulating air, wherein the polyvinylchloride is only in vapor contact with the naphtha.
The package of the present invention is fabricated from the various plastic substances described above by conventional injection molding techniques. 1t is preferable to employ a feed screw worm rather than a piston feed with the hereinV described polyvinylchloride substances.
Y In accordance with the present invention, a package suitable for providing a dynamic seal comprising a resilient cylindrical container and a compatible circular-lid, is provided, said lid and container comprised of a plastic substance that is substantially inert and impervious v.to the contents of the packagewhen the lid and container are brought'into sealing engagement (a)y the outer and inner skirts of the lid embrace the container providing a compressing force on that portion of the container coextensive with the sealing gland, thereby producing a substantial resistance to deforming stresses;
(b) the tapered area of theV sealing gland accommodates the outer rim of the container resultingV in a locking engagement between the lid and the container, and n (c) the sealing annulus of the inner lid skirt and the sealing gland register with .the inner sealing area and outer rim of the container to provide a .primary seal between the container and lid in the sealing gland.
More specifically, the ,present invention provides Vin combination a dynamically sealed package and a pastelike composition having an organic solvent, said com-V position when dynamically sealed in the package having. a shelf life up to at least about18 months at ambient temperatures wherein the dynamically sealed package is as described above. v
In one embodiment, the paste-like composition is a polishing composition comprising a naphtha base solvent and a wax wherein the solvent comprises up to about percent by weight of the composition 4and. the wax cornprises substantially the remainder, from about 20 to about 50 percent by weight. It is readily apparent that compositions having such high solvent concentrations are particularly suited for storage in the instantly described package. Y
In a preferred embodiment'of the invention, the polishing composition comprises:
(l) an aliphatic-naphtha base solvent having a boiling range of from about 275 F. to about 525 F. in concentrations ranging from about 20 to about y50 percent by weight. AAs noted above, o-ther organic solvents can be combined, the aliphatic naphtha base solvents including solvents such as amyl acetate, glycols, vand the cellosolves including butylV cellosolve. Preferably, the naphtha solvent comprises at least 50 percent by weight of the total organic solventV present;
(2) Wax in concentration of from about 2.00 to aboutV Mixtures of hard and soft 30.00 percent-by weight. waxes are preferred in ratios fromabout 10:1 and from about'lzS. kWaxes such as carnauba, microcrystalline and paraffin are preferred;
(3) Oroganopolysiloxanes having a viscosity of from about 50 to about 5000 -cstks. `at about 25 C. and particularly alkylpolysiloxanes such as dimethylpolysiloxane having a viscosity of about 1000 cstks. at about 25 C. in concentrations from about threerto about nine percent by weight; Y
(4) Abrasives such as diatomaceous silica and calcined diatomaceous earth in concentrations-of from about five to about 15 percent by weight,.and Y (5) Water in concentration of from zero to about ,50
percent by weight.
lf desired, preservatives such, as formaldehyde, plasticizers such as oleic acid and morpholine, and pigments and perfumes can also be added according to conventional practice.
A specific example of a preferred polishing composition which is particularly suitedy for packaging` by means of the dynamic seal provided .by the present invention is a whipped, creamy, Vgel-typeV polishing composition cornprising: Y
Centrifuged carnauba waxV 1.50 Hoechst waxes 5 (synthetic wax obtained from crude Montan wax) 2.00 Micro-crystalline wax, MP. 165/ 170 0.80 Parain wax, MP. 0.70 2% solution (ethylene maleic anhydride-cross linked) 15.00 Diatomaceous abrasive (diatornaceou-s'silica) 4.00 Super floss (calcined diatomaceous silica) 2.00 Oleic` acid 0.50 Morpholine 0.75 Dimethylpolysiloxane 1000 cstks. at 25 C. 4.00 Solvent 460 (naphtha) 18.00 HighA flash naphtha #3 20.00 Water soluble dye 0.01 Sodium nitrite` 0.10 Perfume oil-Vandor'7 V V r 0.10 Water 30.54
A series of tests were conducted to determine the permeabil-itythrough polyvinyichloride Eby certain organic solvent base compositions. VThese tests were conducted on polyvinylchloride sheets of varying thicknesses having the typical characteristics described above. T he polyvinylchloride sheets` to ybe tested were placed in contact with the vapor and liquid phases. Y In Vthe case of paste wax compositions, permeability values were obtained with the,
compositions in contact with the sheet and with the sheet in the vapor phase over the composition. All tests were conducted with the outer polyvinylchloride surface exposed to`73 and 50 percent relative humidity circulating air.
In the rst test, polyvinylchloride of varying thicknesses was exposed to 100 percent naphtha vapor for 24 hours with the lfollowing results:
TABLE I Sheet Vapor permethickness ability in in inches grrr/24 hour/ square meter In a second test, the vapor permeability through polyvinylchloride sheets was determined wherein the sheet was in direct contact with a polishing composition similar to that described specifically above in one instance, and with the sheet in contact with the vapor from vthis From the foregoing, it is apparent that the polyvinylchloride tested would be considered substantially impervious for the purposes of the present invention and would be suitable for obtaining a dynamic seal as herein described.
The accompanying drawing illustrates one practical embodiment of the invention but the construction therein shown is to be understood as illustrative only, and not aS defining the limits of the invention.
IFIG. 1 is a cut-away perspective view of the lid and container.
FIG. 2 is an exploded view of the side walls of the container and lid prior to entry.
FIG. 3 is an exploded View of Vthe side walls of the container and lid after entry.
FIG. 4 is an exploded view similar to FIG. 3 with the twist-oit opening means of the invention also disclosed.
In accordance with the present invention, there is provided a package capable of providing a dynamic seal. The package is comprised of a resilient cylindrical container -12land a compatible circular lid `14. As described hereinbefore, the container and lid are comprised of plastic substatnces that are substantially inert and impervious to the contents of the package. v
6 THE CONTAINER Container i12 has an upstanding side wall 16 integral with a bottom wall 18. Annular rim -20 projects outwardly from side wall 16 while continuous .annular sealing area 22 extends inwardly from side wall 16 substantially opposite rim 20. Sealing area ZZ is preferably in the form of a raised slope rather than a sharp protrusion. Annular lrim 20 is provided with an arcuate discontinuity 24 and a ledge 26 which projects outwardly from side wall `16. In a preferred embodiment, the juncture between side wali 16 and bottom wall 11S is curved to facilitate the complete removal `of the contents therefrom. Additionally, bottom wall 18 is provided with a depending annular skirt 28 which provides additional strength and :also functions as a means of support for the container and provides a means of securely stacking the container on the lid of a second container.
THE LID Lid member `1li is provided with outer and inner depending spaced concentric skirts 30 and 32 respectively. Depending skirts 3&0 and 32 dene a continuous tapered sealing gland 134, extending therebetween. (See FIG. 2.) The outer wall of inner depending skirt 32 is provided with at least one and preferably two continuous sealing annuli integral with said skirt. `The sealing annulus iS herein designated as 36 and 36. In a preferred embodiment yof the invention annulus 36 is disposed substantially opposite the lower edge of `outer skirt 3 0. Extending inwardly Ifrom inner skirt 32 and gland 34 is a raised integral annular molding 30. Molding 38 provides integrity and support to lid 14 and provides a rigid support for ifiexing resilient skirts 30 and 32. Lid 14 is provided with a circumferential recessed area 40 having an outerv edge defined by molding 3S. Recessed area 40 is particularly suitable for receiving annular skirt 28 of `container' 12 in a stacking type arrangement.
SEALING ENGAGEMENT When lid 14 and container 12 are brought into sealing engagement the outer and inner skirts 30 and 32 respectively of lid 14 embrace the upper end .of the container wall 16 providing a compressing force on that portion of the container cocxtensive -with sealing gland 134, thereby producing a substantial resistance to deforming stresses.
Tapered area `35 of sealing gland y314 accommodates outer rim 20 of container i112 producing a locking engagement `between lid 14 and container y12. The locking means is responsible for 4retaining the lid on the container and also provides a means of sealing the package.
FIG. 2 illustrates lid l141i and container ywall `16 prior to entry into gland 34. 4It is apparent that when wall 16 bears against annulus 36' the outermost edge of rim 20 extends beyond the inner edge of lid skirt 30. It is also apparent that sealing area 22 extends below annulus 36. Accordingly, in order to seat rim 20 and sealing area 22 in gland 34, suicient force must be applied to container 12 and lid 14 to distort skirts 30 and 32 and rim 2i?, thereby forcing seal-ing area A22. over annulus 36 and rim 20 past skirt 30 into tapered area 35 of gland 34. The leading inner edge v17 of wall 16 is preferably cham- =fered to lfacilitate entry over annulus 36 into gland 34., also provides lead-in for lid 14. FIG. 3 illustrates the lid and container after entry with rim 20 'bearing against tapered area 35 of gland `361 and sealing area ZZbeariug against the outer wall of skirt 32. The circumferential compression force brought to `bear against elements 20 and y22 of container 12 `are evidenced by the bending of wall 16 over annulus 36. This bending results in rim 20 and `sealing area `22 being disposed in a slightly tilted position relative to gland 3d. n
Sealing annulus 36 and sealing -gland 34 register with inner sealing area Z2 and outer rim 20 of the container to provide a primary circumferential seal between con- ,tainer 12 and lid 14 in the area of the sealing gland 34.
In a preferred embodiment of the invention, annular run V2t) has an arcuate discontinuity 24. Disposed below outer skirt 3d is ledge 26 which provides an area'for receiving an opening means such as a coin which registersY in the groove deiined between the bottom of skirt 3i? and ledge 26. Insertion of a coin in this groove and twisting same as shown in phantom in FIG. 4 will break the above described locking engagement obtained between lid 14 and container 12, thus opening the package.
It is believed that our invention and its advantageous characteristics will be appreciated without further description and it should be manifest that the structural details illustrated and described are capable of considerable modification and variation without departing from the essence of our invention as detined in the following claims.
1. A package suitable for providing a dynamic seal comprising a resilient cylindrical container and a compatible circular lid, said lid and container comprised of a plastic substance that is substantially inert and impervious tothe contents of the package:
I. Said container having: Y
(a) an annular rim projecting substantially outwardly from an upstanding side wall, and
(b) a continuous inner annular sealing area projecting inwardly from said side wall;
, ll. Said lid having:
(a) outer and inner depending spaced concentric skirts deiining a tapered sealing gland extending therebetween, and
(b) at least one continuous, sealing annulus integral with the outer wall of said inner skirt;
when the lid and container are brought into sealing engagement:
(a) the outer and inner skirts of the lid embrace the container providing a compressing force on that portion of the container coextensive with the sealing gland, thereby producing a substantial resistance to deforming stresses;
(b) the tapered area of the sealing gland accommodates the outer'rim of the container resulting in a locking engagement between the lid and the container, and
(c) the sealing annulus of the inner lid skirt and the sealing gland register .with the inner sealing area and outer rim of the container to provide a primary seal between the container and lid in the sealing gland.
2. A package according to claim 1 wherein the plastic substance is substantially inert and impervious to naphtha base solvents.
3. A package according to claim 2 where-in the plastic substance is selected from the group consisting of polyvinylchloride, nylon, fluorinated polymers, and poly carbonate polymers.
4. A package according to claim 1 wherein the plastic substance is a rigid polyvinylchloride compound having a specific gravity between about 1.2 and about 1.5 and a thermal deiiection temperature under load of 66 p.s.i. of between aboutl50 and about 180 F.
5. A package according to claim l wherein the lid and container remain in substantially dynamically sealed condition at internal pressure upto about 2O p.s.i.g. at room temperature.l Y
6. A package according to claim l wherein thecontainer and lid remain substantially dynamically sealed at internal absolute pressures across the lid ranging from about 200 to about 300 lbs. at roorntemperature.
7. An assembled package according to claim 1 having a pry-off type lid wherein the outer annular rim of the container has an arcuate discontinuity and also disposed below the outer skirt of the lid to provide an area for receiving an opening means which means can be brought to bear against'the lledge and theiouter skirt of the lid in order to remove the lid `from-the container.
-8. In combination a dynamically sealed package and a package having a shelf life up to at least about 18 months at ambient temperatures wherein the dynamically sealed package comprises a resilient cylindrical container and a compatible circular lid, said lid and container Vcomprised of a plastic substance that is substantially inert and impervious to said polishing composition:
I. Said container having:
(a) an annular rim projecting substantially outwardly from an upstanding side wall, and (b) aV continuous inner annular sealing area projecting inwardly from said side wall; Il. Said lid having: Y
(a) outer and inner depending concentric skirts dening a tapered sealing gland extending therebetween, and (b) at least one Continous, sealing annulus integral with the outer wall otsaid inner skirt;
when the lid and cont iner are brought into sealing engagement: i
(a) the outer and inner skirts of the ylid embrace the container providing a compressing-force on that portion ot the container coextensive Withthe sealing gland, thereby producing a substantial resistance to deforming stresses. f
(b) the tapered area of the sealingf gland accommodates the outer rim of the container resulting in a locking engagement between Vthe lid and the container, and Y (c) the sealing annulus of the inner iid skirt and the sealing gland registerfwith the inner sealing area and outer rim of the container to provide a primary seal between the container and the sealing gland; t
said polishing compositionY comprising an organic and solvent wax.
9. A dynamically sealed package according to claim 8 i wherein the composition is a gel-type polishing composition. Y
10. In `combination ajdynamically sealed package and a paste-like polishing composition having a naphtha base solvent; said composition when dynamically sealed in the package having a shelf lifel up to at least about 18 months at ambient-temperatures wherein,rthe dynamicallyY sealed package comprises a resilient cylindrical container and a compatible circular lid, said lid and container comprised of a plastic substance that is substantially inert and impervious to said polishing composition:
I. Said container having: l
(a) an annular rim projecting substantially outwardly from an upstanding side wall, and (b) afcontinuous inner annular sealing area projecting inwardly from-'said sidewall; Y il. Said lid having:`
(a) outer and inner depending concentric skirts detining a tapered sealing gland extending therebetween, and (b) at least one continuous, sealing annulus integral with the outer wall lof said inner skirty when the lid and container Vare Vbrought into sealing engagement; Y e n (a) the outer and inner skirts of the lid embrace the container providinga compressing force on that portion of the container coextensive with the sealing gland, thereby producing a substantial resistance to deforming stresses,
(b) the tapered area of the sealing gland accomand outer rirn of the container to provide a prit mary seal between the container and lid of the sealing gland; said polishing composition comprising about 35 percent by Weight naphtha, about ve percent by Weight wax, about 41 percent by weight Water, about ten percent by Weight abrasives and about six percent by Weight dimethylpolysiloxane.
i@ Y References Cited in the le of this patent UNITED STATES PATENTS 2,186,962 Foss Jan. 16, 1940 FOREIGN PATENTS 1,173,708 France Oct. 27, 1.958