Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/008—Temporary coatings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D5/00—Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D105/00—Coating compositions based on polysaccharides or on their derivatives, not provided for in groups C09D101/00 or C09D103/00
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D105/00—Coating compositions based on polysaccharides or on their derivatives, not provided for in groups C09D101/00 or C09D103/00
  • C09D105/04—Alginic acid; Derivatives thereof
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D105/00—Coating compositions based on polysaccharides or on their derivatives, not provided for in groups C09D101/00 or C09D103/00
  • C09D105/12—Agar-agar; Derivatives thereof

Definitions

• the invention relates to a method for protecting sensitive surfaces from damage by applying a protective layer.
• the foils are mostly plastic films that are removed and disposed of when the product is delivered or sold.
• the surfaces to be protected are usually painted surfaces, such as motor vehicles.
• a disadvantage of the film coating on the one hand the effort and on the other disposal of the plastic.
• the removal of the plastic film is annoying and then, if it occurs before delivery to the customer, time-consuming and costly.
• the films are generally not biodegradable, but must be recycled or otherwise disposed of.
• the object of the invention is therefore to coat scratch-sensitive surfaces with a protective film which is readily biodegradable, does not stick, can withstand higher temperatures and can be removed again with water.
• This object is achieved by a method of the type mentioned in the introduction, in which the surface to be protected is brought into contact with a gellable aqueous alginate solution and metal ions which cause the alginate to gel.
• the surface to be protected is contacted with a heated aqueous solution of agarose, carrageenan and / or gellan where it is gelled by cooling.
• a heated aqueous solution of agarose, carrageenan and / or gellan where it is gelled by cooling.
• it is usually sufficient to apply the agarose solution to a cold surface.
• carrageenan and gellan alkaline and alkaline earth ions promote gelation.
• the method according to the invention can be applied to all surfaces which are to be protected against damage, in particular scratching.
• the surfaces should be resistant to moisture.
• All of the aforementioned coating agents are natural polysaccharides. These can be modified in a known manner.
• Alginic acid is a high molecular weight natural product of ⁇ -L-guluronic acid and ⁇ -D-mannuronic acid, which may have an average molecular weight in the range of about 40,000 to about 200,000. While the free acid, a white solid, is substantially insoluble in water, the alkali salts, and especially the sodium salt, are soluble in water. Up to 3% solutions can be prepared without difficulty, but they can become very viscous with increasing concentration of alginate. Alginic acid is made from brown algae and some bacterial species and is available in large quantities at low prices.
• a particular property of the alginates is the incorporation of polyvalent metal ions, such as Ca 2+ ions, which proceeds with the formation of a spatial structure and the Gelation and precipitation of the alginate from the aqueous solution leads.
• the reaction is extremely fast and reversible; By dissolving out the calcium ions from the alginate matrix, the alginate becomes water-soluble again and can be "washed off.”
• EDTA can be used as sequestering agent for leaching out the calcium ions, but also citrate.
• the gel formation can also be induced by other metal ions, for example further alkaline earth metal ions, zinc ions, aluminum ions and iron II and iron III ions.
• Alginates have hitherto been used in food technology, in medical technology (capsules), in the textile industry, in the production of photographic papers and in impression taking. Alginate protective films have not yet become known.
• Agarose is a high molecular weight natural product, a polysaccharide of D-galactose and 3,6-anhydro-L-galactose, which are glycosidically linked together, which may have an average molecular weight in the range of about 1 10,000 to 160,000 D.
• Agarose is easily soluble in hot water. Up to 3% solutions can be prepared without difficulty, but they can become very viscous with increasing agarose concentration.
• Agarose is obtained from red algae genera Gelidium and Gracillaria and is available in large quantities at low prices. A special feature of agarose is that your solutions are gel-like, even at elevated temperatures. Agarose solutions are liquid at 95 ° C and solidify at 45 ° C. Commercially available agar contains agarose as the main ingredient.
• Carrageenan is a polysaccharide with a molecular weight of up to 1,000,000 D, which is also composed of galactose and 3,6-anhydrogalactose units which carry partial sulfate groups. Carrageenan is obtained from red algae and comes in several variants. Kappa and Jota carrageenan form solid gels with potassium, sodium and calcium ions. Gellan is a polysaccharide with a molecular weight of about 500,000 D, which consists of phamnose, glucuronic acid and glucose units. It is produced by fermentation of carbohydrates with Pseudomonas elodea. Gellan is water-soluble at elevated temperature and forms stable gels even at a concentration of 0.1% in water.
• Agarose has been used in food technology, in molecular biology for gel electrophoresis, in microbiology for nutrient media, and in plant breeding. Agarose protective films have not yet become known. Gellan is used as a gelling agent in the food industry, carrageenan as a gelling and thickening agent.
• aqueous alginate solution used according to the invention a solution of sodium alginate in water which may contain 0.3 to 3% alginate, in particular about 1%, is particularly suitable.
• the preferred metal ion for the gelling of alginate is the Ca 2+ ion.
• calcium chloride is used in aqueous solution, for example as a 0.3 to 3% solution in water and in particular as about 1% solution.
• Alginate solution and metal ions can be applied to the surface to be protected in any order. This means that the surface can first be sprayed with an aqueous solution of the metal ions, onto which the alginate solution is subsequently sprayed. This leads to gelation.
• the procedure can also be reversed, namely that first the aqueous alginate solution is sprayed onto the surface and then the solution of the metal ions.
• Spraying methods are particularly preferred for the application.
• solutions used according to the invention further solutions in water come into question, containing 0.1 to 3% agarose, carrageenan and / or gellan, in particular about 1%.
• These solutions can also be combined with alginate solutions.
• the forming gel dries with loss of water and formation of the protective layer to an opaque dry film or possibly foam.
• the method results in the formation of a foam on the surface to be protected.
• a foam on the surface to be protected.
• Foam stabilizers can help, such as sodium dodecyl sulfate or ammonium stearate.
• the foam can then be stabilized, possibly with the aid of the metal ions, to form a protective layer which has numerous pores.
• calcium carbonate can be dispersed as fine powder into an alginate foam or the aqueous alginate solution.
• Calcium ions are released by spraying with a weak acid.
• Carrageenan, agarose and gellan solution or foam are examples of Carrageenan, agarose and gellan solution or foam.
• aqueous polysaccharide solution may be biocidally-engineered to prevent infestation with bacteria or fungi. These are common biocides.
• the protective layer formed by the process according to the invention is 0.1 to 5 mm thick, in particular 0.5 to 2 mm.
• the larger layer thicknesses preferably have a foam structure. In the event that no foaming occurs, the required layer thickness can be carried out by repeated application of the protective layer former.
• the protective layer applied according to the invention can be washed off with the aid of a high-pressure cleaner, if appropriate after addition of a sequestering agent, as mentioned above and / or at elevated temperature.
• the inventive method is particularly suitable for the protection of painted surfaces of technical products, such as brand new motor vehicles.
• Another field of application is the coating of surfaces, in which further materials are applied to the protective film.
• the polysaccharide film acts as a separating layer. In this way, for example cast concrete and shuttering can be separated from each other. The same applies to other casting methods.
• the invention further relates to the use of optionally polysaccharide gels contained polysaccharide gels for the protection of technical surfaces, in particular of paint layers, particularly preferably of motor vehicles.
• the starting materials for the process according to the invention can be stored as water-soluble powders.
• the sodium alginate itself is water soluble and dries to a very thin layer.
• the water solubility is considerably limited by the addition of metal ions, so that the protective layer can not be easily washed off and removed.
• Carrageenan, agarose and gellan can be stored as water-soluble powders. Agarose and gellan are water soluble in the heat and dry to a very thin layer.
• the water solubility is considerably limited at room temperature, so that the protective layer can not be easily washed off and removed.
• the solution used can be adjusted to different viscosities, which is important for adjusting the layer thickness on the object to be protected.
• the protective film itself is stable, non-sticky and leaves no marks on touch or after removal. It is easy to remove with the help of aqueous cleaning agents and possibly a sequestering agent. It can be used on all painted, polished and otherwise treated surfaces that are not water sensitive.
• corrosion inhibitors As usual, corrosion inhibitors, UV protectants, fillers and the like can be added to the starting materials.
• Suitable fillers are, for example, Aerosil ® (fumed silica), ⁇ 0 2 ⁇ Nutshell and coconut shell flour. The amount is in the range of 0.1 to 0.5 wt .-%. The fillers make the film more tear-resistant overall.
• an amount of up to 2% by weight, in particular about 1% by weight, of glycerol may be added.

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• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Paints Or Removers (AREA)
• Other Surface Treatments For Metallic Materials (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Laminated Bodies (AREA)

Priority Applications (5)

Applications Claiming Priority (6)

Publications (1)

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Citations (4)

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• 2012
  • 2012-08-17 DE DE102012016275A patent/DE102012016275A1/de active Pending
  • 2012-08-27 WO PCT/EP2012/003594 patent/WO2013026581A1/de not_active Ceased
  • 2012-08-27 JP JP2014526421A patent/JP5972976B2/ja active Active
  • 2012-08-27 PL PL12766578T patent/PL2748267T3/pl unknown
  • 2012-08-27 ES ES12766578T patent/ES2809570T3/es active Active
  • 2012-08-27 US US14/240,623 patent/US10787577B2/en active Active
  • 2012-08-27 EP EP12766578.4A patent/EP2748267B1/de active Active

Patent Citations (4)

Non-Patent Citations (1)

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