DE913846C - Container closure sealing compound and container closures equipped with such as well as methods for introducing such mass into container closures - Google Patents

Description

(WiGBL p. 175)

ISSUED JUNE 21, 1954

D 6306 IVa j 53b

Compared to the manufacture of metal parts, the manufacture of blown glass bodies is an extraordinary one imprecise procedure. As a result, the sealing and sealing of glass containers offer significant greater difficulties and problems than that of metal containers. The seals of the closures must have a considerable mass in order to compensate for the inaccuracy inherent in the glass parts and to form an effective tight seal. This necessity distinguishes the specialty of manufacture Removable closures for glass or metal containers from the tin can manufacture. Both the latter only gets a small amount of liquid sealant into the groove of the can end by means of air pressure or -deckis introduced if the same below the outlet nozzle for the sealant in one Chuck rotates. The dry weight of a seal for a 2 pound (about 900 g) can will vary between 40 and 80 mg, which are distributed over a * circumference of 10.5 inches (about 270 mm). After a such lining of the caulking, the sealant is dried, and then the thin film the dried sealant between two relatively precisely machined metal parts.

compressed when these are rolled together to form a permanent double case.

The savings associated with this so-called flow-in process cannot be achieved in the manufacture of removable closures for glass or metal containers because of the amount of sealing material to be used; so requires z. B. an ordinary screw cap with a circumference of only about 200 mm (7.85 inches), such as those used for mayonnaise and peanut butter jars, already 1 g of sealant. Therefore molded rings made of rubber are still used for such closure caps. Although it requires a lot of work or costly equipment to insert the molded rings into the closure, such is still competitive with the cost of pouring in a large amount of liquid sealant and drying it until it solidifies. In addition, the performance of the flow-in process when it is applied to removable closures for glass or metal containers is only low, because the machines can finish fewer container closures than can ends in the same time and because the container closures in the dryer i ^x / ₂ to 2 hours or more must dwell longer to dry the thick deposit necessary to seal a container in such a manner.

It has now been found that it is possible to use a sealant for use in glass or to produce other removable container closures, which have the following novel characteristics possesses: It can be changed from a liquid to a solid, rubber-like sealing compound without loss of volume be transferred. It can be applied without splashing around. She stays during the whole Manufacturing process in their position on the container closure. It can counter flow at the flow temperature to be immobilized; but you can also give it precisely controllable flow characteristics. It can be reinforced against cutting. It neither settles nor bakes up during storage, but results in uniform seals.

Such a container closure sealing compound, which solidifies at room temperature and is uniform in itself, and container closures equipped with such are achieved according to the invention in that the sealing compound comprises a resin-plasticizer mixture which forms a paste, within which the resin in the plasticizer at 20 ⁰ C is practically insoluble, but practically completely soluble at higher temperatures, and furthermore comprises a filler and a solidifying agent, the solidifying agent making up 2 to 25 percent by weight of the total mass and thus allowing the mass to solidify at room temperature and have a significantly lower viscosity than in the molten state the same resin-plasticizer mixture at the same temperature without the solidifying agent. At medium temperatures (about 32 to 64 ° C) the solidifying agent melts,. and under adequate pressure, for the masses are often thixotropic, the mass becomes a free flowing colloidal liquid. If the mass is heated to even higher temperatures, e.g. B. to about 177 ⁰ C, it flows, ie the resin dissolves in the plasticizer, and the mass then forms a stable, rubber-like mass after cooling.

The material goes through a series of physical transformations: a) First of all, it is a solid, paste-like mass solidified at room temperature; b) it becomes a free flowing liquid when it passes through the applicator nozzle but does not yet show any flux, i.e. H. the resin is still in the plasticizer not resolved; c) it hardens or re-solidifies on contact with the cooler metal fastener; d) it becomes a solution when heated to a temperature high enough to cause the resin to become cause to dissolve in the plasticizer, and finally e) it will on the subsequent cooling to a solid, tough, rubber-like, permanent mass.

These successive physical changes, which take place at different temperatures make what is described below according to the invention Method for introducing the sealant into container closures on high-speed Machines possible.

A small amount of the solidified mass is continuously withdrawn from a container and onto the heated moderate temperature range, at which the material becomes liquid. This liquid is under Pressure is applied to closure blanks through a heated nozzle if this is one of the usual closure delivery machines run through. When it comes into contact with the cold closure blank, the mass solidifies immediately and then stays exactly where it was which it has been applied to the closure, despite all the machine forces that move it strive, and in spite of all the jolts from the advancing mechanism originate from the machine. Then the lined closures go to a heating furnace, where the solidified paste is made to flow in a few seconds or minutes, depending on the type of oven will. Eventually the mass is cooled and becomes a permanent, rubbery one Poetry.

In the drawings is

Fig. Ι a diagram of the viscosity-temperature diagram of the masses according to the invention, the temperatures in degrees Fahrenheit as the abscissa and the viscosities in 1000 centipoises are plotted as the ordinate;

Fig. 2 is a vertical section through a side seal closure; which shows the application nozzle in elevation. This view just recreates the moment shut off the nozzle;

Figure 3 is a partial cross-section through the finished side seal closure shown in Figure 2;

Fig. 4 is a vertical section through part of a one-piece screw cap; the eye iao is shown look straight after the nozzle has been shut off; FIG. 5 is a partial section of the completed closure of FIG

Fig. 4;

Fig. 6 is a vertical section of a flat top closure shown at the moment just after shutting off the nozzle;

Figure 7 is a cross-section of the completed closure according to Fig. 6;

Fig. 8 is a vertical section of a side seal closure just after the nozzle has been shut off; Fig. 9 shows the same section some time after rotating in the chuck;

Fig. 10 is a cross section of the same side seal closure 8 after completion; Figures ii, 12 and 13 illustrate the malleability this mass.

Fig. 11 shows a thixotropic mass contained in the side seal parts 53 of a known commercially available closure 50 is introduced. The nozzle 51 is set so that that it applies the mass 52 on the shoulder and under the small retracted flange 54, the outer edge of the closure forms.

When the closure goes through the flow furnace face up, as shown in Fig. 12, then sags the mass together into a shape, as shown in the cross section of the De.ckels and the finished seal is.

When the closure through the flow furnace with the

Front side goes down, as shown in Fig. 13, then the mass collapses so that it assumes the shape 52 ^, which is in the cross section of the lid and the finished seal is shown.

Closures according to FIG. 12 are used for glasses with an angled edge.

On the other hand, closures according to FIG. 13 are used for glasses with a beaded or cylindrical rim. In addition, the latter type allows the housewife to reseal the jar, because the lid is on the Glass held in slumped belt 55 by the inward thrust of material 52 ^, which results from the warping of the material into the hollow zone 56 when the closure is on the glass is pressed.

The characteristic properties of the mass thus make it possible to use two types of closures from a single mass and a single construction of the metal part.

Three factors are decisive here: solidification, type of filler and control of the resin viscosity are described individually below. * 5 The solidifying agent of the mixture modifies the Resin-plasticizer dispersion and does not cause the whole mass to solidify far from, but certainly above room temperatures. The masses are during transportation and during storage before Seal solid substances or at least stiff gels. The solidifying agent also prevents splashing around the mass due to centrifugal force under the lining machine. The solidifying agent also prevents that the sealant runs when the closures are examined or otherwise treated and it also prevents the individual constituents of the mass from settling or sticking together during transportation and storage.

A significant number of substances can be used for this purpose. Petroleum hydrocarbons, such as

z. B. paraffin wax, long-chain alcohols, such as. B.

Stearyl and cetyl alcohol, as well as glycerides, e.g.

Japan wax are particularly suitable. It has been found that such substances quite unexpectedly reduce the viscosity of the mass when it is ^{heated to about 32 to 64 0} C (go to 150 ⁰ F), and that they cause the viscosity-temperature curve to flatten and the temperature range in which the mass is flowable, expand.

To show the effect of the solidifying agent the following compositions were prepared and their characteristics were measured. These indicators were plotted on the abscissas and ordinates in the same scale units and represent changes of 10 ° F or 1000 centipoises. The graph is shown in FIG.

Masses according to FIG. 1

A B j CID

Vinyl chloride-vinyl acetate

(97: 3) 200 200 200 200

Dioctyl phthalate 280 280 280 280

Zinc resinate 3 3 3 3

Tributyl phosphate 20 20 20 20

Barite 400 400 400 400

. Paraffin wax, mp 52 ⁰ C .. - 36 - - g ₀

Stearyl alcohol - - 45 -

Cetyl alcohol - - - 45

As curve A shows, the viscosity curve of a mass without a solidifying agent gradually drops because the viscosity decreases with increasing temperature. With the addition of a setting agent, as shown by curves B, C and D, the viscosity at room temperature and slightly above is very high; but the curve falls on a point about 32 to 43.5 ⁰ C (90 to 110 ⁰ F) very sharp, almost vertically from, and in a minimum viscosity, which is still below the lowest portion of the curve A. In the temperature range from the sudden change of direction of the curve to about 64 ^° C. (150 ^° F.), curves B, C and D are flat, ie the viscosity remains practically constant despite temperature fluctuations. In the steep slope of the curve, the viscosity of the mass drops by at least 500 and in many cases up to 5000 centipoises per degree Fahrenheit. In contrast, the viscosity-temperature curve A shows a composition which does not contain a solidifying agent, a maximum drop of 250 centipoises, averaging about 100 centipoises per degree Fahrenheit.

Accordingly, the solidification agent maintains the composition at low temperatures below about 32.5 ⁰ C (90 ⁰ F) in a buttery, rigid, plastic state, but permits it to suddenly becomes liquid at the temperature of the sharp drop in the curve and used iao . Immediately after application to the closure, the slight decrease in temperature resulting from the cooling of the mass on contact with the cooler closure is sufficient to restore the mass to its relative stiffness almost immediately.

The mass is placed on the shutter in normal feeding machines applied, the feed line and the application nozzle are heated to the liquefaction temperature of the solidified mass have to.

A closure feeding machine places the closures on a rotating chuck and puts them in rapid rotation, applies the sealant, strips the fasteners from the chuck and pushes

ίο them on a pick-up device at speeds up to 250 closures per minute. At such speeds the liquids are thrown around splashed and spilled. However, the compositions according to the invention have the property to solidify immediately when the closures are touched, thus avoiding any splashing and flinging around will.

By choosing a solidifying agent which gives the mass properties as shown in curves B, C and D, the advantages of the invention are achieved and the application of the mass by high-speed fastener lining machines is made most effective. Curve C shows the viscosity-temperature diagram of a composition with a content of 5 ° / ₀ stearyl alcohol. At about 37.5 ⁰ C (100 ⁰ F) measured by a Brookfield viscometer viscosity is 8750 centipoises. At about 41 ⁰ C (105 ⁰ F), the viscosity amounts to 1250 centipoises and about 43.5 ⁰ C (no ° F) to 760 centipoises. Substances which cause the mass to solidify at room temperature and allow it to liquefy at moderate temperature, ie at about 32 to 64 ^° C. (90 to 150 ^° F), are referred to below as solidifying agents.

Solidifying agents produce the following effects in the compositions according to the invention:

1. A uniform dispersion solidifies without visible Elimination of the individual components. Then there is no settling, caking or significant excretion of the constituents takes place.

2. Fillers and reinforcing materials are solidified in the The parent compound of the initial dispersion is kept rigidly in suspension. So you can do a lot heavy, but on the other hand very effective reinforcing agents, such as barytes, which would otherwise be eliminated, use with benefit.

3. When the heated and therefore liquid material When placed on a cold lid, it freezes almost instantly. The subsequent exam and Treatment cannot move the shift.

4. The mass is in a wide temperature range, e.g. B. between etwa41 to 62.5 ⁰ C (105 and 145 ⁰ F) without significant change in viscosity liquid; therefore, temperature fluctuations at the time the closure is fed out have little influence on the volume of the mass supplied in the unit of time. The stiffness of the mass is restored with a minimum of temperature reduction.
The masses offer the following outstanding advantages: 1. The feeding machines can run faster because a) the mass is not thrown out of the closure, b) 100% of the volume of the liquid is equal to 100% of the solid seal volume and thus less mass in the feeding time must be put in the cap and because 6g 2. drying is superfluous in the usual sense.

Neither water nor a volatile solvent or suspending agent is to be removed. Around to transform the mass from its original plastic state into a rubber-like substance, it is only necessary to bring it to a temperature sufficient to bring the mass to flow (Usually it is exposed to heat for 3 to 5 minutes), after which it is cooled. If the Heat is supplied to the mass as it would in a furnace with a stream of hot air of high Speed happens, then the flow can take hold in a few seconds. Cool after the flow brings the procedure to a close.

The setting and viscosity effects that paraffin wax exerts on such a mass are characteristic of this type of setting agent. In order to emphasize the effect of the setting agent, no filler was added according to the following example. The following mixture was prepared: 280 parts of dioctyl phthalate, 20 parts of tributyl phosphate, 3 parts of zinc resinate, 200 parts of a finely ground copolymer of vinyl chloride and vinyl acetate (about 97: 3). To this mixture varying amounts of paraffin go, mp. About 52 ⁰ were C (125 ⁰ F), added. At 10% paraffin and above, the dispersion was a solid paste at room temperature. With decreasing paraffin contents, first a stiff slurry and then a non-flowing sludge (at 2%) was obtained. The viscosities were measured with a Brookfield viscometer. When a mass was heated with a wax content of 10%, the viscosity fell from 3180 centipoises at about 37 ⁰ C (98 ⁰ F) to 400 centipoises at about 44 ° C (in 5 ° F), but subsequently fell in the temperature range from about 44 to 62.5 ° C (iii.5 ° F) only around 280 centipoises. The curves for concentrations of 4% and above were similar and rectangular. The curves for concentrations below 4% showed, even at concentrations as low as 2%, although they deviated from the rectangular shape, a visible decrease in viscosity at the same temperature and a much steeper change in viscosity than the curves for the pure resin-plasticizer Mixture.

The following experiment shows the effect of the solidifying agent on settling and caking. Five samples of the same basic composition were prepared, containing the following parts by weight: 240 polyvinyl chloride acetate, 3.6 zinc resinate, 24 tributyl phosphate, 480 barite (chosen because of the high specific weight), 336.8 dioctyl phthalate. Various amounts of paraffin wax from 0 to 10 ⁰ J ₀ , based on the weight of the whole mass, were added to these samples. Alternating amounts of additional dioctyl phthalate were added to the iao samples with a content of less than 10% paraffin wax. The purpose of the additional plasticizer was to adjust the viscosities of all samples to about 350 centipoises, so that the effect was achieved with a constant viscosity of the compositions

of the paraffin wax could be determined on the settling alone. The samples were at room temperature ι month, with the following results:

Amounts of the added Weight Amount of viscosity behavior sediment Wax share additional at about 49 ⁰ C
(120 ⁰ F) when weaning (Cake) in percent
of weight 0.0 Plasticizer the whole crowd 27.8 Parts by weight 361 cP 30% clear serum Hard not to stir 0.00 57.0 144 360 cP 20% clear serum Soft, easy to stir 2.28 92 352 cP 8 ° / ₀ clear serum Very soft, so could 4.78 50 moved away again 87.9 will. 120.0 348 cP 0% 7.25 45 347 cP 0% 10.00 0

The action of the setting agent takes on useful forms at 2% of the total concentration.

An optimum does not exist, but the physical properties of the seals are unfavorable at wax concentrations greater than 10 ° / _0, and at a tensile strength of 25% Dehnungsund penetration assume values such that the composition has no commercial moderate significance. These values are not absolute; they vary depending on the specific solidifying agent and the specific filler used, but represent average values.

Instead of paraffin, other materials, such as e.g. B. Japan wax, long-chain alcohols, such as. B. stearyl and cetyl alcohol, and mixed paraffins of various Use origin. These produce a sharp drop in the viscosity curve near their melting point of the mass and keep the mass at a low viscosity over a wide temperature range. Diglycol stearate, beeswax, polyamide wax, candelilla wax, octadecenylamine, polyethylene glycol and myristic acid or amorphous waxes, e.g. B. those that are extracted from lubricating oils, In contrast to crystalline waxes, they cause the mass to solidify and thus prevent anything The constituents settle out, but they do not cause a sharp kink in the viscosity-temperature curve; nor do they show a permanent low viscosity over a wide temperature range. the end for this reason they can only be used in lower-speed feeding processes will.

The choice and treatment of the filler is the second factor of the present combination which the mass adapts to specific manufacturing processes and specific closure constructions. It three different effects on the heated liquid mass can be achieved by the fillers: a) Newtonian viscosity, d. H. Systems in which increasing pressure is directly proportional to the amount of flow increased to the applied pressure.

b) thixotropy, d. H. Systems in which each increasing force exceeds a certain threshold value exceeds, the amount of flow does not increase in proportion to the force applied.

c) dilation, d. H. Systems in which suddenly applied forces result in additional resistance and the amount of flow is inconsistent with the force applied.

Crystalline fillers generally impart Newtonian viscosity, e.g. B. barite in dioctyl phthalate. The gasket can add rigidity and resistance to cutting by adding Newtonian fillers be awarded; however, this does not affect the flow properties of the molten mass influenced. This is the case with the manufacture of closures with a sealing groove in the cover according to FIG. 4 and 5 in which a recessed groove or retaining ring is pressed into the metal. When a such a closure provided with a seal liner and then with the seal side up in the Is brought into the flow furnace, the mass melts and every irregularity in the lining disappears, because the liquid seeks its own level and flows together to form an even ring.

It has been found that when the resins listed in the exemplary embodiments are used, a ratio of resin to plasticizer = 55:45 results in a stiff mass which is just suitable for rotating filling machines. The consistencies, as they are suitable for nozzle application machines, amount to weight ratios of 50:50 and below. Resin to plasticizer ratios below 25:75 are too soft for an effective closure seal. Other resins and other plasticizers also impose other limits on the weight ratios. The limits for the weight ratios of the fillers cannot be specified precisely. A relatively small proportion (8%) of hydrous calcium silicate z. B. makes a mass too stiff to use. On the other hand Barite is a use-enabled mass in a filler to resin weight ratio of 80: 20. Most fillers require ⁰ these limits.

It has been found that the sealant in a flat closure lid according to FIGS. 6 and 7 is attached provided that the mass is made so thixotropic that it can be made even when melted does not flow under its own weight. In general, Thixotropic 1 as are imparted by flaky fillers,

like ζ. B. clay in dioctyl phthalate or hydrous magnesium silicate (fibrous), titanium dioxide, lithopone, etc. The threshold should be within the limits that it prevents the flow of the liquid mass under its own weight and allows the mass to exit through nozzles. When such a mass touches the cooler shutter, it becomes immobile because it solidifies; it resists impact and does not flow when molten.
ίο Dilatation is desirable when the closures are conveyed through the furnace by means of an intermittent device. In this case it is advantageous to give the mass a resistance to suddenly occurring forces. Alpha cellulose flakes in dioctyl phthalate are a typical example. The mass becomes stiffer as the shear increases. Other fillers, especially whiting chalk, often have a dilate effect.

Fillers cannot be divided into certain categories. Your concentration in the crowd and the specific plasticizer seem to determine the properties. Barytes in dioctyl phthalate z. B. give a Newtonian viscosity; in tricresyl phosphate they act somewhat dilatently. By making use of these properties, individually or in combination, the mass can meet the respective requirements of the closure sealing process.

The third factor of the combination according to the invention is the regulation of the resin viscosity. The most important The property of the resin is that it is relatively insoluble in the cold plasticizer, but in the the same plasticizer should be easily soluble at higher temperatures. Such resins, e.g. B. Polymers vinyl chloride or copolymers of vinyl chloride and acetate are well known.

It is also known that resins which are soluble in the plasticizer are insoluble in the same plasticizer can be made if you put the finely divided resin in a heat transferring inert suspending agent such as B. light paraffin oil, heated.

Hereinafter, the term paste forming resin is used for a resin, which still gelled in a specific plasticizer mixture at 20 ⁰ C (68 ° F) neither appreciably dissolved but practically completely dissolves at higher temperature and upon cooling forms a gel with the plasticisers .

Since the amount of liquid sealant that can be applied to the lid is determined by the Amount of mass which passes through a certain opening under a certain pressure and during can be pressed for a certain time, the exact adherence to the viscosity is one Precondition for a uniform closure production. The resin tends to be very plasticizer not appearing in the form of individual dispersed particles, but rather in the form of large agglomerates, and if they are too large, the viscosity of the mass may be indeterminate will. Large agglomerates are prevented by carefully moistening all of the components. This can be done by prolonged milling, but a mixture of the filler is preferred and part of the plasticizer is tributyl phosphate or zinc resinate, or preferably a mixture add both, grind this until it is well and evenly moistened, and then the heart and add the plasticizer and finally the setting agent and the remaining plasticizer and continue grinding until fine grain uniformity is achieved. Such an approach reduces the possibility of large lumps of resin forming. Other sequences in accessories and various operations also give usable results.

The manufacture of a one-piece vacuum side-seal closure makes extraordinarily high demands.

Side seals are commonly used on jelly jars, spread jars, and sauce bottles. They are characterized by a strip of sealing material running along the neck the bottle or the rim of the glass extends downwards, practically at right angles to it the disc-shaped part of the closure. A common method for making such Closures consists in putting a tubular sealing strip into the angled edge portion of the Insert the fastener and then bead the bead, to hold the seal in place.

Example I.

Stage ι parts by weight

Barite 2000

Titanium dioxide 1 _p . 72

Soot J ^ri § ^mem ϊ

Acid washed kaolin 2250

Dioctyl phthalate 2000

Machining in the pan mill until uniform.

Level 2 parts by weight

Add: _10g

Tributyl phosphate 360

25 ° / _o by weight solution of zinc resinate in

Dioctyl phthalate 216

Continue processing until a smooth mixture is achieved.

Level 3 parts by weight

Add to:
Mixed polymer of vinyl chloride

acetate (ratio 97: 3) 3000

Dioctyl phthalate 1000

Continue processing in the pan mill.

Level 4

Parts by weight

Paraffin, m.p. about 52 "C (125 ⁰ F) 400

Dioctyl phthalate 500

Melting together. When uniformity is achieved, add hot to Stage 3 product. Increase the temperature in the pan mill to about 49 ⁰ C 120 ° F).

Level 5
Add to:

Acid (phosphoric, maleic, benzoic or other acid) to adjust the

Plasticity of the kaolin ioo

Grind at about 49 ⁰ C (120 ⁰ F) for ¹ Z ₂ hours. The mass is then poured into containers and allowed to cool. It solidifies in the dispersed state, ίο whereby the fillers and the resin are uniformly suspended in the mass. At room temperature the material is a stiff, paste-like, solid mass. Before adding the acid and at about 49 ⁰ C (i20 ° F), this mass shows a viscosity of 3000 centipoises at 60 rpm. (Brookfield viscometer) and a viscosity of 11000 centipoises at 6 rev / min. After adding the acid, the same material at about 49 ° C (120 ⁰ F) has a viscosity of 9600 centipoises at 60 rev./min. and from ao 44000 Centipoises at 6 rev / min. At the flow temperature (175 ° C = 345 ° F of the surrounding medium) the material can slowly collapse and flow under its own weight to a small extent. The closures are lined as follows. It can be used normal Deckelausfütterungsmaschinen when the nozzle, the feed line and the reservoir heated and all parts of the system heated to normal Ausfütterungstemperatur with a tolerance of 5 ⁰ F (about 2.8 ° C) are maintained.

Fig. 2 shows a vertical section through a one-piece side seal vacuum cover 10. The nozzle 11 is shown in elevation; it should be set at the correct angle in order to apply the mass 12 to the jacket 13. The jacket ends in an open turn 14. As a result of the solidification of the mass, which occurs as soon as the mass assumes the position at 12, the closure can be turned over and placed on a base. It is then placed in a flow furnace that is maintained at a temperature of 175 ° C (345 ⁰ F), where in 2 to 5 minutes, the collapsing of the mass I2- ⁴ of the same allows the shell 13 along downward, then to the open Convolute 14 to flow, lodge there and protrude slightly above the jacket to form the convex zone 15, and then come into flow to form a permanent, rubber-like, solid ring. The closure is ready when it has cooled down. When such a closure is placed over a cylindrical glass with a side seal, the convex zone 15 is delimited radially by the jacket 13, and part of the seal pushes into the concave zone 16 and firmly grips the glass. This gives a re-lockable facility.

One-piece screw cap and strap closures usually have a groove to hold the mass in keep. Masses for this can e.g. B. can be produced as follows:

Example II
Stage ι parts by weight

Barite 400

Dioctyl phthalate 157

Processing in the pan mill.

Parts by weight level 2

Add to:

Parts by weight

20th

Tributyl phosphate

25 ° / ₀ solution of zinc resinate in dioctyl phthalate 12

Further processing to create a smooth blend.

Parts by weight

level 3
Add to:

Vinyl chloride-vinyl acetate copolymer (ratio of chloride to

Acetate = 97: 3) 200

Dioctyl phthalate 67

Continue the pan mill processing and raise the temperature of the mixture to approximately 52 ⁰ C (125 ° F).

Level 4 parts by weight

Add to:

Paraffin wax, m.p. about 52 ° C

(125 ° F) 37-5

Melted in dioctyl phthalate ... 47.0

The pan processing is then continued for a considerable time at a temperature of 46 to 52 ⁰ C (115 to 125 ⁰ F). The mass is then poured into containers and allowed to cool down in them. The viscosity at 44 ° C (no ⁰ F) is 700 centipoises. " ₅

Such a mass is only suitable for closures which have a groove or which otherwise inhibit the flow of the fluid. This type is represented by the shutter 20 (Figures 4 and 5). The same application machine and the same application ratios are used as are described in Example 1, but the nozzle 21 is set vertically so that the mass 22, as shown, flows into the groove. Since the mass solidifies in the position shown, the closures ₁₀ can be checked and treated as desired. They are then brought to 2 to 5 minutes at a temperature of 175 ⁰ C (345 ⁰ F) with the extended fed face up into the flow furnace. Since the temperature rises before it comes into flow, the mass becomes very fluid and flows. The flow compensates for any irregularities in the lining.

Example III

Level ι

Parts by weight

Dioctyl sebacate 173.9

Tricresyl Phosphate 173.9

Zinc resinate 3.6

Polyvinyl chloride 240.0

Barite 482.0

Paraffin wax 45.0

The dioctyl sebacate is heated together with the tricresyl phosphate while stirring continuously in the zinc resinate to about io6 ° C (225 ° F) until the Zinc resinate is completely dissolved.

Level 2

^{The mixture of stage 1 is} cooled to 65.5 ° C. (150 ° C.), then paraffin wax is added and the mixture is stirred.

level 3

When the wax is completely melted, barite is added. Stir for 5 minutes.

Level 4

The temperature is lowered to about 49 ° C (120 ⁰ F). Polyvinyl chloride is added. Stir for 10 minutes while maintaining the temperature at about 49 ° C (120 ° F).

Level 5

The mixture is left at a temperature of about 49 ° C (120 ⁰ F) go through a colloid mill.

Level 6
The mass is allowed to run into a container and to cool.

At about 32 ⁰ C (90 ° F), the viscosity of the mass is equal to 6000 centipoises; it is slightly thixotropic. The measurement of the viscosity with a Brookneld viscometer at 60 rev / min. shows the viscosity drops from 6000 centipoises at about 32 ° C (90 ° F) to 500 centipoises at about 47.5 ° C (117.5 ° F). The mass is used and applied according to the instructions given in Example III.

Example IV
Stage ι parts by weight

Barite 2000

Kaolin 3000 washed with acid

Titanium dioxide 72

Soot ι

Dioctyl phthalate 1500

Process in the pan mill or in a ball mill until the mixture is a smooth, uniform paste has become.

Level 2 parts by weight

Add to:

Tributyl phosphate 360

25% strength solution of zinc resinate in ^e

Dioctyl phthalate 216

Dioctyl phthalate 860

Grind further until completely mixed.

Level 3 parts by weight

Add to:

Copolymer of vinyl chloride
and vinyl acetate

(in a ratio of 97: 3) 3000

Dioctyl phthalate 1000

Continue milling and raise the temperature to about 52 ⁰ C (125 ⁰ F).

Level 4 parts by weight

Add to:

Paraffin wax, m.p. 52 ° C (125 ° F) 400 Melted in dioctyl phthalate ... 500

The milling about ¹ Z continue for ₂ hour at about 46 to 52 ° C (115 to 125 ⁰ F). Pour the mass into containers and let cool.

This mass is extremely thixotropic. The following table shows the viscosity of the mass at around 43.5 ° C (iio ° F) and various forces.

Brookfield viscometer

Spindle speed
per minute Viscosity in centipoises o, 3 850,000 0.6 520,000 i, 5 230,000 3, o 140,000 6.0 82 500 12.0 45,000 3O, o 29,000 60.0 21 500

Over considerable periods of time, these and similar masses show the property of "cold flow" go above the solidification temperature, but not during the times of the process steps. There is no measurable flow in the course of ^{1 and} _{2 minutes.}

The high degree of thixotropy, as can be seen from the table above, enables manufacture of closures according to FIGS. 6, 7, 8 and 9. In the manufacture of flat-lid closures according to 6, the mass is allowed to flow into the cover next to the jacket 33. The threshold of this mass is so large that a 66 mm fastener with a 25o rev. min. can revolve, resulting in a centrifugal force of about 2.2 times the force of gravity, without that the mass climbs up the mantle. When the nozzle is shut off, the mass solidifies immediately, and these closures can then be passed on or checked without running the risk of the Sealing ring is moved. The mass does not flow when in the process of influencing because its thixotropy is high enough to prevent anything flowing under its own weight. The mass flows together to form a rubber-like ring, which adheres to the upper part of the closure, as Fig. 7 shows. If you make the threshold mass high enough, roughly equal to three times that gravity, then the closures can be made at reasonable speeds, without the vibrations of the machine being able to cause a displacement of the mass.

The same mass can be used to make the side seal closures according to FIGS. 8, 9 and 10 to manufacture. The nozzle 41 is adjusted so that it the mass 42 is applied to the jacket 43 of the closure 40. One chooses a speed that is high enough is to generate a centrifugal force which spreads the mass on the shell 43; 500 rev / min. result in a centrifugal force of 8.96!

Gravity on a closure 66 mm in diameter. Upon rotation of the closure, the mass flattens to a band which upwards, but to slide the casing also downwards against the lid of the closure in order to g shown in FIG. General to take shape. This material does not move either when it solidifies or is heated in a flow furnace.

The closures are brought into flow by placing them in an oven at a temperature of about 176 ^° C (345 ^° F) for a period of 2 to 5 minutes; then let them cool down. A cross-section of the finished closure is shown in FIG. It will be noted that the mass, which has now become a solid, rubber-like ring, has the same shape as the unfluxed mass shown in FIG.

These masses show the right-angled characteristic curves of curves B, C and D in FIG. 1. The recommended ones Lining temperatures, d. H. the temperatures for application fall within the dashed area of the Figure. For operations at the highest speed, the lining temperature range should be close to the bend of the Curve can be held so that freezing is at a minimum Temperature change can occur.

The above examples show preferred embodiments for dry and hot preserved foods. For commercial products, however, the choice is much greater. Closures for products such as paints, Insecticides, finishes, etc., do not require odorless plasticizers; furthermore is the poisonous effect the constituents of lesser importance.

Some of the tried and tested operating materials are listed below in tabular form.

Polymers Solidifying agent Plasticizers Fillers Wetting agents 100 Polyvinyl chloride Stearyl alcohol Dioctyl phthalate Barite Tributyl phosphate ₈ , Polyvinyl chloride Cetyl alcohol Dioctyl sebacate Fibrous Zinc resinate acetate Magnesium silicate Mixed polymer
from vinylidene chloride
and acrylonitrile Diglycol stearate Tricresyl phosphate talc Magnesium resinate Myristic acid Dicapryl phthalate Ge with acid go
Sorbitol dioleate 105 washed kaolin Polyethylene glycol Petroleum frac lignin Rosin resin tions with high Polyamide wax Content of aroma Finely ground oil-free lecithin g ₅ tables and naph- calcium carbonate 110 Mixed long thenic chain amides Hydrocarbon Aluminum oxide Sodium petroleum fabrics sulfonate Octadecenylamine Methyl acetyl Fine slate flour Ricinoleate Paraffins "Flexol N 8" Alpha cellulose unknown to flakes Different composition, More graphitic paraffin prepared by mica mixes the Carbide & Car bon Chemical Company Japan wax Cork flour Amorphous Mixtures of the Lithopon Petroleum wax above substances Candelilla wax Kieselguhr Beeswax Calcium silicate

Glass closure feeding machines now work at speeds of 225 to 280 per minute. The nozzle is open and injects mass into the closure during one or two turns, depending on the thickness desired Seal, and the lined closure is removed after about one more turn The application nozzle has been shut off.

The present invention enables the same machine to run at speeds of 356 to 700 per minute to let work. It has been found that the mass is smoothed against the jacket and that the The mass is given enough time to solidify if the closure is turned one more revolution after the nozzle has been shut off power. During this time the solidification has progressed to such an extent that closures, which are produced by the Machine can be removed immediately after ejection, can be treated roughly without adding to the mass move.

Although these masses are specially designed for glass closures, which are relatively thick sealing elements require, they can also be used for sealing containers, which less

Require sealing material, ζ. B. for closures on containers made of metal, paper or plastics.

Claims (8)

PATENT CLAIMS: 1. Container closure sealing compound, which solidifies at room temperatures and is uniform in itself, and container closures equipped with such, characterized in that the sealing compound is a paste-forming resin-plasticizer mixture, within which the resin in the plasticizer at 20 ⁰ C is practically is insoluble, but practically completely soluble at higher temperatures, and also contains a filler and a solidifying agent, the solidifying agent making up 2 to 25 percent by weight of the total mass and thus solidifying the mass at room temperature and having a significantly lower viscosity than that in the molten state ao same resin-plasticizer mixture for the same temperature without the solidifying agent. 2. Container closure sealant and with such equipped container closures according to claim i, characterized in that the sealant contains a filler which gives the mass sufficient thixotropic properties and thus prevent the same from flowing under the action of gravity and the sealant even at temperatures above their Solidification point does not show any flow under the action of gravity for at least V _{2 minutes.} 3. Container closure sealing compound and with such equipped container closures according to claim ι or 2, characterized in that the sealing compound is a resin made of polyvinyl chloride and contains paraffin wax as a solidifying agent. 4. Container closure sealant and container closures equipped with such one of claims 1 to 3, characterized in that that the sealant contains a filler which is proportional to the flow capacity of the mass to increase the pressure applied and which when the mass is heated on their Viscosity exerts little influence. 5. Procedure for applying the sealant according to one of claims 1 to 4 in container closures on high-speed machines, thereby characterized in that the sealant is applied at a temperature at which it has a low viscosity, then allowed to cool and continue to sufficient Solidification is circulated. 6. The method according to claim 5, characterized by such a speed of the rotating parts, where the centrifugal force is more than three times the force of gravity, and by adhering to one Average temperature of the closure below the solidification temperature of the mass. 7. The method according to claim 5 or 6 for introducing sealant into container closures with side jacket, characterized by the reversal of the lined closure or lid, by increasing the temperature of the closure to the pour point of the mass, through which Regulating the temperature rise of the mass such that it is in the temperature range between their melting point and their pour point flows and in the zone next to the edge of the closure collapses, by the introduction of the mass and by the subsequent cooling of the closure, whereby a thickened ring of sealing compound on the inner wall of the closure jacket is formed next to the edge. 8. The method according to any one of claims 5 to 7, characterized in that the sealing compound is applied in a heated state to the base, while this is on a below the The solidification point of the mass is kept at a temperature, the mass then solidified by heating the base to flow and finally the whole thing is cooled. 1 sheet of drawings © 9522 6.54