SK280239B6 - Coating material for glass surfaces and its use - Google Patents

Abstract

A coating material contains, as the film-forming component, mono- or di-carboxylic acid esters with a total of up to 40 carbon atoms in a molecule and up to 10 weight percent of by an alkyl group modificated siloxanes of the general formula (I) wherein R1 and R2 is methyl or C8-24alkyl and at least two groups R1 or R2 in a molecule denote alkyl with a long chain, m = 1 to 200 and n = 0 to 50, as well as nonionic emulgators, thickening agents, preservatives and water. Said coating material is usable for repeated applying upon glass surface with 0 - 50 degrees Celsius, especially upon an outer surface of hollow glass containers.

Description

Technical field

BACKGROUND OF THE INVENTION The present invention relates to a train mass for glass surfaces for covering traces of wear, such as scratches and scratches on the glass surface, in particular reusable container glass.

BACKGROUND OF THE INVENTION

Glass containers filled with, for example, beverages such as milk, beer, fruit juice, mineral water or lemonade are largely returnable containers. After collection, they are returned to the manufacturer after use and refilled. The bottles are damaged during transport and when filled by touching the bottles or touching metal surfaces. These wear marks should be overlapped. To this end, several requirements must be met:

- good coverage of scratched areas,

- water resistance after only a short time,

- Applicability also for wet bottles

- non-sticky coating with pleasant feel,

- no impact on labels, inks and label adhesives,

- perfect washability of films and desirable behavior in an alkaline wash bath,

- toxicological harmlessness.

Films must have good hiding power for traces of wear while being water resistant. Since glass containers are often stored in refrigerators and refrigerated counters, the coatings must be resistant to condensation water. The film deposit must also be operable on wet and cold bottles. The film must not be sticky because stickyness would be unacceptable to the customer and, moreover, the coating would become contaminated by the application of dust. The thermal curing of the film is not feasible due to the high filling speed, and the filling material could be affected. It must be ensured that the film can be washed with an alkaline water bath.

Although methods have already been proposed for covering traces of wear which are not removable by an alkaline washing bath. However, they are not advantageous because the glass containers are refilled, transported, emptied, collected and washed repeatedly. The permanent film itself is easily damaged and then has undesirable traces of wear. During the washing process, the quality of the coating deteriorates, so that it becomes, for example, opaque in the milk. In addition, layer thicknesses of up to 50 µm are desirable in such a case; this is unacceptable in terms of the cost of covering traces of wear.

The current state of the art for solving this problem is already described in detail in U.S. Pat. No. 4,237,334, which discloses a formulation consisting of high molecular weight polysiloxane resin with methyl, phenyl and alkoxy groups on silicon atoms dissolved in hydrocarbon solvents such as toluene and xylene. This method is inconclusive with regard to hygienic and toxicological considerations.

The use of low molecular weight, and thus ethanol-soluble, polyorganosiloxins is described in U.S. Pat. No. 3,574,673. The adhesion to the glass surface is improved by the introduction of monofunctional groups. A disadvantage of this method is the use of flammable solvents. Due to the use of aminofunctional groups, a marked yellow color is observed upon storage of the treated bottles.

The use of modified polyorganoxiloxanes containing functional groups such as amino, mercapto and / or trialkoxysilyl groups to improve adhesion to glass surfaces is described in U.S. Pat. No. 4,222,554. The crosslinkable polyorganoxiloxanes are cured using a toxicologically based tin catalyst. doubtful.

U.S. Pat. No. 4,662,221 discloses polysiloxanes in combination with cationic and nonionic surfactants. A process based on polysiloxanes that can be applied in volatile polysiloxanes as solvents to the surface of bottles is disclosed in EP-A-3 95077.

EP-A-464779 discloses triglyceride emulsions which can be prepared using nonionic emulsifiers and additional paraffinic and silicone oil components.

In all of these methods known in the art, considerable amounts of polysiloxanes are generally used. These substances, however, are degraded under the washing bath conditions to the volatile, ring sulfoxane monomers D3, D4 and D5. However, this is undesirable in filling plants and especially in breweries as foam stability problems may occur. The use of polysiloxanes is therefore critical for the practical use of coating agents in filling plants and therefore difficult to maintain or avoid.

DE-C-33 41 121 discloses paraffin oil emulsions and waxes, fatty acid esters being used as emulsifiers. Sodium polyacrylate and morpholine fatty acid salt are added to improve both coating and processability characteristics. However, paraffins, as short-chain oils, have only a low water resistance and impart a sticky effect to the film. On the other hand, higher melting waxes with long chain cover imperfectly and form an undesirable foam in the washing bath by dissolving the film particles, which is deposited on the surface of the glass containers and interferes with the washing process.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a train material which meets all the requirements and has not elucidated the drawbacks of the prior art.

SUMMARY OF THE INVENTION

According to the invention, the coating composition for covering the traces of wear of glass surfaces consists of a monocarboxylic or dicarboxylic acid ester having a total of up to 40 carbon atoms in the molecule and up to 10% by weight of alkyl-modifying groups as a film-forming component.

where it means

R ¹ and R ^{2 are} methyl or C 8 -C 24 alkyl and at least two R ¹ or R ² in the molecule are long chain alkyl, m 1 to 200 and 0 to 50.

The coating composition of the invention has a melting point lower than the processing temperature.

Examples of the lime-forming component are ester oils such as ethylhexylethylhexanoate, isopropyl myristate, butyl stearate, butyl laurate, diethylhexyl adipate or ethylhexyl palmitate.

Known non-ionic emulsifiers, such as fatty alcohol ethoxylates, fatty acid sorbitan ethoxylate, polyglycerine fatty acid ester, fatty acid methyl glucoside ethoxylate, fatty acid glycerine ethoxylate ester or alkylpolyglucoside (cetylglucoside) cetylglucoside (cetylglucoside) are used to disperse the film-forming component. .

Thickeners, such as polyacrylates or cellulose ethers (hydroxypropylcellulose), can be added to adjust the desired processing consistency. Preservatives such as, for example, formaldehyde-based commercial agents are preferred to prevent infestation by microorganisms.

The coating compositions according to the invention are used in the form of aqueous suspensions, preferably with the following composition by weight:

a) 1.0 to 40.0% of at least one film-forming substance according to the invention,

b) 0.5 to 12.0% nonionic emulsifier,

(c) 0 to 5,0% of a thickener;

d) 0 to 2.0% preservative,

e) 41.0 to 98.5% water.

A variety of methods can be used to fill hollow glass containers in fillers. The coating composition according to the invention can be applied using a spray apparatus or even with a cloth, felt or sponge or in the form of a film on a glass surface.

It is preferred that the film-forming ester oil component be in liquid form and that uniform wear coverage is achieved. Preferably, therefore, ester oils are used whose freezing point is below the processing temperature. The glass surface temperature is 0 to 50 ° C.

It is particularly advantageous to apply the coating composition according to the invention to worn hollow glass containers in filling plants by means of injection spraying devices which are used in packaging marking systems. The electronic control of these systems is modified to meet specific requirements to cover worn areas, ideally spraying only on areas where the hollow glass containers are abraded.

The coating effect appears both on hollow glass containers which are at room temperature during application and are dry, as well as on wet and cold bottles. The effect does not change over a period of several weeks, or when stored in a refrigerator or refrigerated counter. Label material, label colors and label size are not adversely affected. The coating material in the bottle washing step is completely removed and does not cause any problems in the alkaline washing bath. The film-forming components of the invention are acceptable as emollients in cosmetic compositions and are toxicologically harmless.

The invention is illustrated in more detail by the following examples.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

The ingredients are mixed with water. Using a homogenizer, a stable master emulsion is prepared with an active compound content of 60%. In use, the master emulsion is then diluted to a content of 5 to 10%. This coating material is sprayed onto bottles filled with water and sealed with a cork crown cap, which have been stored in a refrigerator for at least 12 hours. The bottles already have significant condensation in condensed water. The coating composition is evaluated by the coating characteristics of the traces of wear and by the water resistance after rinsing with water and by the feel of the bottles. Six marks are used for the evaluation, which means 1 very good and 6 very bad qualities. 6 bottles are rated for statistical reasons. The test results are shown in Table I.

Table I

Active substance emulsions Gaci coverage feel of Water resistance etylhexylizononanoát A 4 2 2-3 etylhexyletylhexanoát B 4 2 2-3 laurate B 3 2 2 isopropyl stearate A 1 2 2 isopropyl A 1 1-2 1-2 izoacetylpalmitát A 1 2 2 palmitate C 2 3 3 cetyl A 1-2 2 2 Comparison of triglyceride caprylic / capric acid A 4 3-4 3-4

A = ethoxylated glycerol oleate (eg TAGAT ^R O, Th. GoldschmidtAG)

B = aqueous dispersion of alkyl polyglycosides based on _C12 / _C14 alcohols

C = C ₁₆ / C ₁₈ glucoside (C ₁₆ ) C ₁₈ alcohol.

Industrial usability

A glass-coating composition comprising as a film-forming component a monocarboxylic or dicarboxylic acid ester having up to 40 carbon atoms per molecule and an emulsion comprising at least one film-forming material, non-ionic emulsions or thickeners, preservatives and water.

Claims (6)

PATENT CLAIMS Coating composition for covering traces of wear on glass surfaces, characterized in that it contains, as a film-forming component, a monocarboxylic or dicarboxylic acid ester having up to 40 carbon atoms per molecule and up to 10% by weight of alkyl-modified siloxanes of the general formula R ¹ and R ^{2 are} C 8 -C 24 alkyl or at least two R ¹ or R ² in the molecule are long chain alkyl, m 1 to 200 and 0 to 50. Coating composition according to claim 1, characterized in that it comprises a film-forming composition 3 Ester oil having a total carbon number of 10 to 32, in particular 12 to 24, with a melting point lower than the processing temperature. The coating composition according to claim 1 or 2, characterized in that the carboxyl portion of the film-forming component contains 3 to 28 carbon atoms and the alcohol portion contains 4 to 24 carbon atoms. Coating composition according to claims 1 to 3, characterized in that the film-forming component is isopropyl myristate. Coating composition in the form of an aqueous emulsion, characterized in that it contains by weight a) 1.0 to 40.0% of at least one film-forming substance according to claims 1 to 5, b) 0.5 to 23.0% nonionic emulsifier, (c) 0 to 5,0% of a thickener; d) 0 to 2.0% preservative, e) 41.0 to 98.5% water. Use according to claims 1 to 3 for repeated application to a glass surface at a temperature of 0 to 50 ° C, in particular to the external surface of hollow glass containers.