EP1789325B1 - Method for preventing serum formation during storage of paste-type preparations - Google Patents

Abstract

The invention relates to a method for preventing serum formation during the storage of paste-type preparations by preventing the separation of packed stable paste-type preparations. According to said invention, said packaging is exposed to a gas prior to or during a filling operation, wherein said gas is at least partly is absorbed by said preparation. The thus available forms of the product, which is problemlessly stored without appearance of separation, are also disclosed.

Description

The present invention relates to a method for avoiding the separation of stable pasty preparations, which are present in packaging, as well as supply forms, the problem-free, i. without Separationserscheinungen, are storable.

A frequently observed problem in the storage of pasty preparations is that a change in viscosity within the preparation occurs over time. Often, this change is noticeable in that a portion of the paste-like preparation is due to viscosity reduction in much thinner form than the rest of the preparation. The usually resulting in the separation thin phase is undesirable in the application practice.

The process of separation is particularly disadvantageous if this results in a shift in the application properties. For example, in the case of the first application of adhesives filled in tubes, it often happens that first the thin-bodied, separated part of the adhesive is applied to the surfaces to be bonded. Due to the qualitative defects of the separated part, it may then come to complaints because of lack of adhesive power or other technical defects.

Similar observations can be made in other fields of application. For example, the separation in hair dye pastes can lead to a reduced or altered effect of the more liquid part of the preparation.

In the patent application US 3960187 A describes a method for packaging pasty preparations, wherein the packaging is charged during filling with a gas. A disadvantage of this method is that this method is not suitable to prevent the separation of paste-like preparations.

In the previous practice, this stability disadvantage was taken in the absence of a solution. In order to avoid disadvantages for the consumer, it is recommended in some cases, for example with some hair dye pastes, in the product description, on first use, to discard the part of the preparation that first leaves the tube.

Object of the present invention was to develop a simple solution for this unsatisfactory situation. In particular, a filling method and forms of supply should be developed which should easily lead to the separation of pasty preparations being prevented.

1. a) die genannte Verpackung vor oder während des Befüllens mit einem Gas beaufschlagt wird und
2. b) das genannte Gas zumindest teilweise in der genannten Zubereitung aufgenommen wird.

Accordingly, the present invention is a method for avoiding the separation of stable pasty preparations, which are present in packages in which

1. a) the said package is charged with gas before or during filling, and
2. b) said gas is at least partially taken up in said preparation.

As a paste-like preparation, the present invention understands formulations which have extrusion values of 100 g / min. up to 5000 g / min. The preparations are particularly preferably the formulation of solid particles in a liquid matrix. The determination of the extrusion values is carried out, for example, based on the standardized methods ISO 9048, DIN EN 29048. In these methods, the preparation is filled into an extrusion tube and the extrusion is carried out under standard conditions and a pressure of about 200 kPa. The amount of extruded product is determined. The extrusion rate is given by the following formula: $$\mathrm{extrusion\; rate}\left[\mathrm{mL}/\min \right]=\mathrm{Amount\; of\; extruded\; product\; per\; time}$$

The inventive method leads to particular improvements when the outlet of said packages compared to the part of the packaging to which the outlet connects, is significantly tapered. For example, it has been found that the advantages of the method according to the invention are particularly noticeable when the outlet is in the form of a narrower screw thread as compared to the packaging directly adjacent to the outlet.

In addition, another preferred embodiment of the method is provided when said package is placed downwards when being filled with the outlet. In practice, then usually collects the less liquid part of the paste-like preparation in the channel of the narrower outlet. As a result, the amount initially applied from the packaging is generally of a different quality than the rest of the preparation. Defects in the application and complaints are therefore often foreseeable.

It is also preferred if, upon exercise of the method according to the invention, the outlet of the packaging is formed of plastic material, preferably polyethylene, polyamide, PET, PVC or polypropylene.

In a further preferred embodiment of the method according to the invention, the filled pasty preparations are stored in said packagings for up to one-half, preferably up to a whole and more preferably more than a whole year, without separation phenomena occurring. This is particularly important because in industrial practice bottled products are rarely delivered directly to the consumer. Most of the mentioned products are stored intermediately and / or are still in supermarkets or similar facilities for a long time before they are opened for the first time and fed to the application.

The gas to be used in the process according to the invention is preferably chosen such that it at least partially dissolves in the said preparation and / or reacts with one of the components contained in the preparation.

It is particularly advantageous if the said gas is selected from CO ₂ , butane, pentane or methylal.

Depending on the recipe, however, it may be that the selection of the gas is important for the suppression of the separation properties. In this case, it is recommended to examine the gases in question in the process of the invention and to compare their effect on the separation behavior. If, for example, adhesives based on silane-terminated polymers are filled in the context of the process according to the invention, it is particularly preferable to use CO ₂ as the gas to be used; however, if the systems are NCO-containing, pentane is to be particularly preferred as the gas to be used according to the invention.

The inventive method is preferably applied to filling processes of pasty preparations in which the pasty preparation is introduced via a pipe or a tube-like hollow body in the packaging during filling. It is particularly preferred if the tube is introduced during filling to more than two thirds in the package.

In a further preferred embodiment of the method according to the invention, the gas to be used according to the invention is introduced into the packaging via a pipe or a pipe-like hollow body. It is particularly preferred as in the filling of the preparation, when the tube is introduced during filling to more than two thirds in the package. In particular, it is preferred that the tube extends to where the outlet joins the remainder of the package.

A further preferred embodiment of the method according to the invention can be realized by arranging said tube or tube-like hollow body for the application of the gas in or around or adjacent to a tube or tube-like hollow body to be used for the application of the paste-like product. Advantage of this procedure is that at

Implementation of the most automated filling process at the same time the tube for the product and gas supply must be introduced into the package to be loaded. As a rule, an acceleration of the filling process is associated with such an approach: one saves an additional process step for the introduction of the product tube.

In the context of the method according to the invention, however, it may also be preferable on a case by case to arrange the tube or the tube-like hollow body provided for the gas supply independently of a tube or tube-like hollow body intended for the supply of the pasty preparation and preferably the said gas in a separate step into the packaging.

As already indicated above, the filling process in the context of the method according to the invention is preferably carried out in a conventional rotary machine. It is particularly preferred if 5 to 30, preferably 10 to 20 packages are filled per minute.

In a preferred embodiment of the offer form is in the said preparation, in particular in the outlet part of said preparation, a process according to the invention gas to be used in at least partially dissolved and / or reacted with one of the components contained in the preparation form.

It is particularly advantageous if the said gas is selected from CO ₂ , butane, pentane or methylal.

Depending on the recipe, however, it may be that the selection of the gas is important for the suppression of the separation properties. The statements made above in this context for the method according to the invention apply correspondingly to the subject of the present invention.

In a further preferred embodiment, the outlet of said package is made of plastic material, more preferably polyethylene, polyamide, PET, PVC or polypropylene.

There is also a preferred form of the offer form when said preparation is substantially anhydrous. By "essentially anhydrous" it is to be understood that the proportion of water, based on the total preparation, is less than 1% by weight, more preferably less than 0.5% by weight and most preferably less than 0.1% by weight.

Examples

In the context of the present invention, three formulations have been investigated for the applicability of the invention.

For the preparation of the formulations, a paste of the components Alkylsuresulfonester, chlorinated paraffin, PVC powder and pigments was first stirred together. The respective amounts are included in Table 1. This paste was heated to 70 ° C. After cooling to 40 ° C., a prepolymer in the amounts shown in Table 1 was added with stirring. This was followed by the addition of the other ingredients according to Table 1. Then, it was degassed at a pressure of 30 mbar. Table 1: Example formulations for reviewing the procedure Paste A Paste B Paste C PU prepolymer * 29 29 29 Reactive Polysiloxanes ** 0.5 2.0 6.0 alkylsulfonic 18.1 17.6 16.3 chlorinated paraffin 7.8 7.6 7.1 PVC powder 31.1 30.3 28.1 TiO ₂ 5 5 5 Other pigments and additives 8.5 8.5 8.5 * The PU prepolymer used was made from
- 62 wt.% Polypropylene glycol
24% by weight of polyether polyol and
15% by weight of technical diphenylmethane-4,4'-diisocyanate (MDI)
** Dihydroxypolydimethylsiloxane with a viscosity of 350 Pas was used.

With the paste-like preparations compiled according to Table 1, in a process according to the prior art, two packaging tubes were filled and sealed via a tube. During the filling process were the

Tubes with closed screw cap arranged downwards. The filling did not take place via the outlet of the tube, but via an upwardly pointing opening of the tube, which was closed in the usual way after completion of the filling process.

With the same paste-like preparations according to Table 1, packaging tubes were also filled and sealed in a method modified according to the invention. The only difference with the first method was that when using the second method before filling the tubes with paste, the tubes were each blown with carbon dioxide for about 30 seconds. The supply of carbon dioxide was carried out via a tube, which was introduced for this purpose up to the height of the screw cap in the tubes. After subsequent filling with the pastes according to Table 1, these tubes were sealed as above.

All tubes filled in this way were stored with the screw cap downwards at room temperature for a period of 8 weeks.

Then a paste strand of about 10 cm length was applied to a DIN A4 paper sheet from each tube. This was followed by the visual assessment of the corresponding paste strands. The results are summarized in Table 2. Table 2: Visual evaluation of the test strands prepared by experiment Method 1 - Evaluation of paste strand Method 2 - Assessment of paste strand Paste A About 2 cm before the actual strand of paste begins, there is an approximately 1 cm wide and 2 cm long blob-like strip of a thin liquid composition, which emerged directly from the tube when applying the paste. The strip runs thin and forms a transparent layer on the paper. Then, about 0.5 cm overlapping with the blob-like strip, the expected strand of paste follows. The strand has an elongated cylindrical shape and has a diameter of about 0.5 cm. As desired, a pure paste strand is present without the upstream blob-like strip observed in Procedure 1. The strand has an elongated cylindrical shape and has a diameter of about 0.5 cm. Paste B The same appearance as in method 1 with paste A The same appearance as in method 2 with paste A Paste C The same appearance as in method 1 with paste A The same appearance as in method 2 with paste A

As the examples set out show, the separation of thin parts which occurs during storage of pasty preparations can be prevented by the process according to the invention.

Claims (15)

1. Method for preventing the separation of stable, paste-type preparations in packagings, wherein

   a) said packaging is exposed to a gas before or during the filling process, and

   b) said gas is absorbed, at least in part, in said preparation.
2. Method according to claim 1, characterised in that the outlet of said packagings tapers considerably compared to the part of the packaging to which the outlet is connected, for example in the form of a screw thread which is narrower than the packaging.
3. Method according to either claim 1 or claim 2, characterised in that said packaging is arranged with the outlet downwards during the filling process.
4. Method according to one or more of claims 1 to 3, characterised in that no separation is observed, even after storage times of from six to twelve months.
5. Method according to one or more of claims 1 to 4, characterised in that said gas dissolves, at least in part, in said preparation and/or reacts with one of the components contained in the preparation.
6. Method according to one or more of claims 1 to 5, characterised in that said gas is selected from CO₂, butane, pentane and methylal.
7. Method according to one or more of claims 1 to 6, characterised in that the outlet is formed from plastics material, preferably from polyethylene, polyamide, PET, PVC or polypropylene.
8. Method according to one or more of claims 1 to 7, characterised in that said paste-type preparation is introduced into the packaging during the filling process via a tube or a tubular hollow member.
9. Method according to claim 8, characterised in that the tube is inserted into the packaging by more than two-thirds during the filling process.
10. Method according to one or more of claims 1 to 9, characterised in that said gas is introduced into the packaging via a tube or a tubular hollow member.
11. Method according to claim 10, characterised in that said tube or tubular hollow member is inserted into the packaging by more than two-thirds, preferably as far as the region of the outlet part, when gas is introduced.
12. Method according to either claim 10 or claim 11, characterised in that said tube or tubular hollow member is arranged in or beside a tube or tubular hollow member to be used in accordance with either claim 8 or claim 9.
13. Method according to one or more of claims 10 to 12, characterised in that said tube or tubular hollow member is arranged independently of a tube or tubular hollow member to be used in accordance with either claim 8 or claim 9 and said gas is preferably introduced into the packaging in a separate step.
14. Method according to one or more of claims 1 to 13, characterised in that the filling process is carried out in a conventional rotary machine.
15. Method according to one or more of claims 1 to 14, characterised in that from 5 to 30, preferably from 10 to 20, packagings are filled per minute.