Classifications

• • 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
  • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
  • B05D7/06—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to wood
  • B05D7/08—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to wood using synthetic lacquers or varnishes
• • 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
  • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
  • B05D7/50—Multilayers
  • B05D7/52—Two layers
  • B05D7/53—Base coat plus clear coat type
  • B05D7/536—Base coat plus clear coat type each layer being cured, at least partially, separately
• • 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
  • B05D2203/00—Other substrates
  • B05D2203/20—Wood or similar material
• • 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
  • B05D2502/00—Acrylic polymers
• • 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
  • B05D2508/00—Polyesters
• • 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
  • B05D2601/00—Inorganic fillers
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31652—Of asbestos
  • Y10T428/31663—As siloxane, silicone or silane

Definitions

• the present invention relates to a combination coating for wood comprising an alkyd resin primer and a silicate coating applied thereto, and a kit consisting of an alkyd resin coating composition and a silicate coating composition and a method of applying the coating.
• Alkyd resins are generally polyester compounds of polybasic acids (e.g., phthalic acid, isophthalic acid, maleic acid) and polyhydric alcohols (especially glycerol or pentaerythritol), with excess OH groups esterified with unsaturated fatty acids.
• polybasic acids e.g., phthalic acid, isophthalic acid, maleic acid
• polyhydric alcohols especially glycerol or pentaerythritol
• Alkyd resins for example, are obtainable by transesterification of a drying oil with an excess of polyol and subsequent reaction with acid anhydride. Other methods are based on acid, the alcohol and the corresponding fatty acid mixture.
• the fatty acid content is expressed in terms of the weight fraction of the oil and referred to as "oil length".
• a short oil alkyd resin has an oil length of typically 20-40%, a middle oil of 40-60%; Over 60% is generally called long-oil alkyd resin. The greater the oil length, the lower the degree of polymerization of the polyester component, and the higher the proportion of fatty acids per polyester molecule.
• Alkyd resin based paints are often used to coat wood. Wood is a relatively soft, working substrate. For a good adhesion to wood must have a Coating therefore have a certain elasticity, which is the case with alkyd paints.
• Alkyd resins are not UV-resistant. Therefore, alkyd paint coatings on wood outdoors must be renewed regularly.
• Silica coatings such as those used outdoors for coating mineral substrates or metallic surfaces, are UV-resistant and very durable, but relatively mechanically rigid, and therefore generally do not adhere permanently to wood.
• One possible solution to this problem is the use of a higher elasticity primer which serves as an adhesion promoter between the soft wood and the hard silicate paint.
• alkyd paint coatings are generally unsuitable as a primer for silicate paints since the silicate paint catalyzes the saponification of the alkyd resin. This may cause the alkyd resin to decompose before it hardens. For this reason, such combinations do not adhere permanently to wood.
• the present invention has for its object to provide a coating for wood, which is UV-stable and permanently adherent.
• the present invention provides a combination coating of alkyd primer and silicate coating, as well as the appropriate combination of suitable alkyd resin coating composition and silicate coating composition.
• the invention also relates to a method for applying the combination coating according to the invention.
• the alkyd resin coating composition which can be used according to the invention can preferably also comprise drying accelerators (A-4).
• Component (A-1) is a long-oil alkyd resin having an oil length of at least 60%, for example in the range between 60-90%, in particular 70-80%.
• the oil is here Semi-drying or drying oil with an iodine value according to DIN 53241-1 of more than 100, preferably more than 130 and especially preferably more than 160.
• oils with suitable fatty acid composition are thistle oil, linseed oil, dehydrated castor oil, sunflower oil, soybean oil, tung oil, or fish Lead oils.
• Tall oil fatty acid based alkyd resins are also contemplated.
• the component (A-1) is contained in the primer preferably in a proportion of 40-60% by weight.
• the alkyd resin dries too slowly and the alkyd resin primer can saponify upon exposure to the silicate paint, thereby rendering the durability of the combination coating insufficient.
• Suitable alkyd resins are commercially available, for example, as Setalin or Uralac Jägalyd.
• the component (A-2) consists of mineral particles and acts as an adhesion promoter. It is required for the adhesion of the silicate coating on the undercoat layer, and is preferably contained in a proportion of 5-25% by weight in the alkyd resin coating composition. Lower levels may result in degraded adhesion of the silicate coating to the primer. Particularly preferred are proportions of 10-15 wt.%.
• the particle size may be for example 1-80 microns, preferably 4-10 microns.
• mineral particles come into consideration, such as are typically used as filler, matting agents or pigments.
• silica or silicate material such as precipitated SiO 2 , diatomaceous earth (diatomaceous earth) or silicate minerals such as mica, kaolinite, muscovite or chlorite.
• Carbonate minerals such as calcites or oxides such as alumina, calcia, titania, magnesia, zirconia and / or boria are also suitable.
• oxidic pigments for example based on iron oxide, are also suitable.
• barite or zinc sulfide can be used.
• Component (A-2) can also consist of a mixture of different minerals, for example a mixture of different phyllosilicates.
• any solvent suitable for alkyd resin paints can be used in principle.
• hydrocarbon-based solvents such as e.g. Lead white spirit.
• the alkyd resin coating composition preferably contains an agent (A-4) which catalyzes the radical crosslinking of the unsaturated fatty acids. Suitable for this purpose are all siccatives customary in the prior art for alkyd paints.
• metal salts which are soluble in the coating composition in particular transition metal salts of organic acids, for example cobalt 2-ethylhexanoate.
• the agent (A-4) is used in an amount of 0.005 to 0.3% by weight, preferably 0.01 to 0.1% by weight.
• the alkyd resin coating composition may also contain other ingredients conventional in the art, as long as they are not detrimental to the adhesion of the silicate coating.
• anti-skinning agents such as 2-butanone oxime or thickening agents (e.g., bentonites) can be cited.
• the alkyd resin coating composition can be obtained by the conventional method by diluting the component (A-1) with the solvent (A-3) until the desired viscosity is reached and then stirring in the mineral component (A-2).
• a polymer (B-3) and / or an organic ammonium compound (B-4) may also be contained.
• Other optional ingredients include pigments, thickening and dispersing agents, and water as a solvent.
• Silicate paints which can be used according to the invention are described, for example, in US Pat DE 100 01 831 respectively EP 1 222 234 described.
• the molar ratio of SiO 2 to alkali oxide in the water glass or in the mixture of water glass and silica sol is 5-30 moles of SiO 2 per mole of alkali oxide, preferably 15-25 moles of SiO 2 per mole of alkali oxide, and particularly preferable 20 moles of SiO 2 per mole of alkali oxide.
• the constituents, as usual in silicate analysis are defined in relation to the oxides, even if compounds such as silicates or the like are actually present.
• glass glassy solidified melts of alkali metal silicates and their aqueous solutions, which are obtainable from alkali metal carbonates and SiO 2 .
• the water glass or the mixture of water glass and silica sol acts as binder and brings about the special properties of silicate coating materials.
• the coating composition is silicated, ie, the binder is converted into a water-insoluble silicate network, which optionally includes the components of the substrate.
• the water glass used is generally made by fusing quartz sand with alkali carbonate.
• the alkali oxide of the water glass is, for example, lithium, sodium or potassium oxide. Potassium oxide is preferred because it is less prone to blooming and cheaper than lithium oxide compared to sodium oxide.
• the alkali metal oxide is preferably 0.5 to 3% by weight, more preferably 0.5 to 0.8% by weight, based on the total weight of the silicatic coating composition. Above all, a content of alkali oxide of 0.5% by weight is preferable.
• Silica sol is understood as meaning aqueous solutions of colloidal silica.
• an alkaline silica sol is used.
• a solids content of 10 to 50% is preferred.
• the silica sol advantageously has an average particle size of ⁇ 10 nm.
• the silica sols used are also preferably characterized by a very uniform and fine distribution spectrum.
• the water glass or the mixture of water glass and silica sol is preferably 3 to 40 wt.%, Particularly preferably 15 to 35 wt.%, Based on the total weight of the siliceous coating composition. If a mixture of water glass and silica sol is used, the silica sol may be present in a proportion of from 3 to 30% by weight, based on the total weight of the siliceous coating composition.
• the silicatic coating composition which can be used according to the invention comprises a mineral component (B-2).
• component (B-2) Materials suitable, which also come for the mineral component (A-2) of the alkyd resin coating material in question.
• the mineral component (B-2) comprises one or more of the usual fillers in the art, preferably in an amount of 10 to 45 wt.% Of filler (s), based on the total weight of the siliceous coating.
• a particularly smooth and shiny surface of the silicate composition is obtained when the component (B-2) contains a crystalline filler of the class of calcite.
• the component (B-2) contains platelet-shaped substances such as phyllosilicates (mica, kaolinite, muscovite, chlorite) as filler. If component (B-2) contains such platelet-shaped substances, their proportion is preferably 5 to 25% by weight, particularly preferably 10 to 20% by weight, based on the total weight of the silicatic coating composition.
• component (B-2) may contain baryte as a filler. If component (B-2) contains barite, the proportion is preferably 3 to 15% by weight, particularly preferably 9 to 11% by weight, based on the total weight of the siliceous coating composition.
• mineral component (B-2) examples include oxides from the group of alumina, calcia, titania, magnesia, zirconia and / or Boron oxide, as well as mineral pigments to match a desired color.
• pigments mineral oxides, in particular oxides having a rutile or spinel structure, such as e.g. Iron oxides used. If the component (B-2) contains pigments, their proportion is preferably 5 to 20% by weight with respect to the weight of the coating composition.
• the silicatic coating composition which can be used according to the invention can furthermore contain a polymer.
• Polymer-containing silicate coating materials are used in particular as dispersion silicate paints.
• the addition of a polymer provides greater flexibility of the coating obtained after silification, which is advantageous for adhesion to the alkyd primer.
• dispersion silicate paints can contain a maximum of 5% organic components.
• a polymer content of up to 15% by weight, based on the total weight of the silicatic coating composition, in particular 1 to 15% by weight is advantageous.
• a polymer content of 3 to 10 wt.% is advantageous.
• the polymer is usually incorporated in the form of a dispersion in the silicate coating composition.
• the solids content of the polymer dispersion is preferably from 20 to 80% by weight.
• the polymer is a (meth) acrylate homopolymer or copolymer.
• Particularly preferred is a butyl acrylate-methyl methacrylate copolymer.
• the silicatic coating composition which can be used according to the invention can be admixed with an organic ammonium compound (B-4) for stabilization against gel formation.
• suitable ammonium compounds are in DE 100 01 831 and include compounds of formula (I): + NR 1 R 2 R 3 R 4 X - (I) wherein R 1 , R 2 and R 3 each independently represent an alkyl group having 1 to 20 carbon atoms which may optionally be substituted with a functional group, or hydrogen, R 4 represents an alkyl group having 1 to 20 carbon atoms, hydrogen or (CH 2 ) x -N + R 5 R 6 R 7 is Y-, wherein R 5 , R 6 and R 7 each independently represent an alkyl group having 1 to 20 carbon atoms, which may optionally be substituted with a functional group, or hydrogen, and wherein at least one R 1, R 2, R 3 and R 4 is not hydrogen, x is a number between 1 and 6 and x - represent an anion, respectively - and Y.
• the functional group as a substituent of the alkyl group may be, for example, a hydroxy group, an amino group, a thiol group, preferably a hydroxy group.
• the choice of anion is not limited so long as it does not diminish the effect of the organic ammonium compound, eg the anion can be F - , Cl - , Br - , I - or OH - .
• the alkyl groups of formulas (I) and (II) contain from 1 to 6 carbon atoms, and selected examples are methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, pentyl, hexyl and cyclohexyl.
• Selected examples of a hydroxy-substituted alkyl group having 1 to 6 carbon atoms are hydroxymethyl, hydroxyethyl, 1-hydroxypropyl and 2-hydroxypropyl.
• R 1 , R 2 , R 5 and R 7 each represent a methyl group
• R 3 and R 6 are each a 2-hydroxypropyl group
• x is a number between 1 and 3
• X - and Y - are OH- respectively.
• the organic ammonium compound is preferably contained in the silicate coating composition at 0.1 to 3% by weight, based on the total weight of the silicate coating composition.
• the siliceous coating composition may contain other ingredients as long as they are not detrimental to the object of the invention.
• additives customary in the prior art for example thickeners, water repellents, dispersants and / or defoamers.
• thickeners are polysaccharides, cellulose, bentonite and xanthan. Their content may be from 0.1 to 5% by weight, based on the total weight of the siliceous coating composition.
• the hydrophobing agent may e.g. Polysiloxanes and especially amino-functional polysiloxanes include.
• the hydrophobing agent may be present at 0.1 to 5 weight percent, based on the total weight of the siliceous coating composition.
• the dispersant e.g. Tetrasodium N- (1,2-dicarboxyethyl) -N-alkylsulfosuccinamid be used.
• the dispersant is preferably present at 0.1 to 0.5 wt.%, Based on the total weight of the siliceous coating composition.
• hydrophobic silica liquid hydrocarbons, nonionic emulsifiers and / or synthetic copolymers may be present in the silicate coating composition.
• the preferred amount of antifoaming agent is from 0.1 to 1% by weight, based on the total weight of the silicatic coating composition.
• the silicate coating composition may contain water, preferably in a content of 20 to 50 wt.%, Based on the total weight of the silicate coating composition.
• the silicatic coating composition which can be used according to the invention can be prepared by first dispersing the mineral component (B-2) in water, then optionally adding the organic ammonium compound (B-4) and optionally subsequently the polymer (B-3) in the form of a dispersion , After good dispersion, the water glass or the mixture of water glass and silica sol is added, then optionally further additives, such as thickeners and / or water repellents. By further stirring a very homogeneous dispersion is obtained.
• a silicatic coating composition which can be used according to the invention can be prepared as follows: First, the waterglass or the mixture of waterglass and silica sol is initially introduced and optionally mixed with the organic ammonium compound (s). For this purpose, the mineral component is then added, wherein optionally usually first the pigments and then the fillers are stirred. Subsequently, if appropriate, a polymer dispersion can be stirred in. Last, the addition of other additives can be done, such. As a thickener and / or a hydrophobing agent.
• the primer described above is applied by brush or airless on planed pinewood boards. After drying for 24 hours under standard conditions (23 ° C and 50% relative humidity), the boards are coated with the above-described silicate paint with a brush or roller.
• a wood sample produced in this way was initially stored for two weeks at standard climate and then tested in a short-term weathering according to DIN EN 927-6. At the end of the 2000 hour test period prescribed in the standard, the coating was still completely intact.
• silicate paint 1 described above was applied directly to the planed pinewood boards without previous priming. Subsequently, the wood sample thus prepared, as described in Example 1, stored for two weeks under standard conditions and then tested in a short-term weathering according to DIN EN 927-6.
• the alkyd primer 1 described above is applied by brush or airless on planed pinewood boards. After drying for 24 hours under standard conditions (23 ° C. and 50% relative humidity), the boards are coated with a commercial dispersion silicate paint according to DIN 18 363 2.4.1, which has the following composition: 30% by weight Potassium water glass with a molar ratio of SiO 2 to potassium oxide of 2.55 4% by weight Butyl acrylate / methyl methacrylate dispersion 10% by weight TiO 2 40% by weight Filler mixture of calcium carbonate and mica Balance: water
• a wood sample thus produced was then stored for two weeks under standard conditions as described in Example 1 and then tested in a short-term weathering according to DIN EN 927-6.
• a commercially available alkyd paint system (Xyladecor wood protection glaze) was twice applied with a brush to planed pine wood boards. The wood sample was then, as described in Example 1, stored for two weeks under standard conditions and then tested in a short-term weathering according to DIN EN 927-6.
• a mixture of Gus 18% by weight of silica sol (particle size 5-8 nm, solids content 30% by weight) and 6% by weight of a 29% potassium silicate solution are stirred in. After dispersion, 10% by weight of a polysaccharide solution (solids content 5% by weight) are added. As a further addition, 2% by weight of a 50% emulsion of an aminoalkyl-substituted polydimethylsiloxane is added.
• the primer described above is applied by brush or airless on planed pinewood boards. After drying for 24 hours under standard conditions (23 ° C and 50% relative humidity), the boards are coated with the above-described silicate paint by brush or roller.
• the pinewood boards thus produced were stored for two weeks under standard conditions and then, as described in DIN EN 927-3, free-weathered. After expiry of the test period of one year prescribed in the standard, no flaking or other paint damage was observed.
• the silicate paint 2 described above was applied directly to the planed pinewood boards without prior priming. Subsequently, the wood sample thus prepared, as described in Example 2, stored for two weeks under standard conditions and then freeze-weathered according to DIN EN 927-3.
• Pinewood boards were coated with an alkyd resin primer (DELTA Impregnation Primer 1.02) containing no mineral fillers and dried for 24 hours. Subsequently, the boards were coated with the silicate paint 2 described above. After two weeks of drying under standard conditions, cross-cut tests according to EN 927-3 Annex C were carried out. The silicate paint peeled off along almost the entire cut length.

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• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Wood Science & Technology (AREA)
• Paints Or Removers (AREA)
• Chemical And Physical Treatments For Wood And The Like (AREA)
• Application Of Or Painting With Fluid Materials (AREA)

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Citations (4)

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• 2009
  • 2009-01-14 EP EP20090150512 patent/EP2208544B1/fr active Active
  • 2009-01-14 PT PT09150512T patent/PT2208544E/pt unknown
  • 2009-01-14 PL PL09150512T patent/PL2208544T3/pl unknown
  • 2009-01-14 AT AT09150512T patent/ATE530262T1/de active
  • 2009-01-14 DK DK09150512T patent/DK2208544T3/da active
  • 2009-01-14 ES ES09150512T patent/ES2375597T3/es active Active
• 2010
  • 2010-01-14 CA CA 2690282 patent/CA2690282A1/fr not_active Abandoned
  • 2010-01-14 US US12/687,203 patent/US20100178519A1/en not_active Abandoned

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