CA2034952C - Protective coating for wood against damage by light containing undercoating comprising sterically hindered phenols - Google Patents
Protective coating for wood against damage by light containing undercoating comprising sterically hindered phenols Download PDFInfo
- Publication number
- CA2034952C CA2034952C CA002034952A CA2034952A CA2034952C CA 2034952 C CA2034952 C CA 2034952C CA 002034952 A CA002034952 A CA 002034952A CA 2034952 A CA2034952 A CA 2034952A CA 2034952 C CA2034952 C CA 2034952C
- Authority
- CA
- Canada
- Prior art keywords
- process according
- resins
- tert
- butyl
- undercoat
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
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
-
- 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
- C09D5/002—Priming paints
-
- 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
- C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
- C09D7/40—Additives
- C09D7/48—Stabilisers against degradation by oxygen, light or heat
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
- B27K3/00—Impregnating wood, e.g. impregnation pretreatment, for example puncturing; Wood impregnation aids not directly involved in the impregnation process
- B27K3/34—Organic impregnating agents
- B27K3/50—Mixtures of different organic impregnating agents
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/04—Oxygen-containing compounds
- C08K5/10—Esters; Ether-esters
- C08K5/101—Esters; Ether-esters of monocarboxylic acids
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Chemical And Physical Treatments For Wood And The Like (AREA)
- Paints Or Removers (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
- Anti-Oxidant Or Stabilizer Compositions (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
A protective coating for wood comprising a) an undercoat which penetrates the surface of the wood and contains a phenolic antioxidant, and b) a conventional top coat.
The top coat preferably contains a light stabiliser.
The top coat preferably contains a light stabiliser.
Description
Protective Coating for Wood a ainst damage by light containing Undercoating comprising Sterically Hindered Phenols The present invention relatca to a method of protecting wood surfaces against damage by light and to a protective coating for wood.
Wood surfaces which are exposed to sunlight are damaged in particular by the UV light present in the sunlight. The polymeric constituents of the wood are degraded, so that the surface undergoes roughening and discolouration. As a consequence, attack by microorganisms, especially fungi, giives rise to further damage.
The conventional method of protecting wood against light-induced degradation, without having to forgo the attractive appearance of the wood surface, is to coat the wood with a colourless varnish which contains a light stabiliser, especially a UV
absorber.
Investigations have also bec,n made to determine whether the addition of an antioxidant to the protective coatings rein:Forces the effect of the light stabiliser in the wood varnish.
According to D.N.S. Hon et al., J. Appl. Polymer Sci. 30 (1985), 1439, no, or only an insignificant effect, is obtained.
The addition of phenolic antioxidanla to wood varnishes is known. For example, US patent specification 3285855 discloses the colour stabilisation of furniture varnishes based on acid-curable urea/formaldehyde alkyd resins by adding 0.2% by weight of a phenolic antioxidant.
Wood protective coatings which contain a UV absorber, an antioxidant and an insecticide are disclosed in the publication of the JF' patent application Sho 59-115 805, published July 4, 1984.
It has now been found that antioxidants of the type of the the sterically hindered phenols have a marked stabilising acaion against light-induced degradation if they are applied, without the addition of a light stabiliser, to an undercoat which penetrates the surface of the wood, and the wood is then provided with a top coat, which top coat may contain a light stabiliser.
Accordingly, the invention ,relates to a method of protecting wood surfaces against light-induced degradation by treatment with a) an undercoat which penetrates thc: surface of the wood and which does not contain a light stabiliser, said undercoat comprising an aqueous or organic solvent, or said solvent containing a binder selecaed frorr~ the group consisting of alkyd resins, modified alkyd resins, acrylic resins, polyester resins, drying oils, phenolic resins, nitrocellulose resins and mixtures thereof, and b) one or more top coats, comprising a resin selected from the group consisting of nitrocellu-lose, polyvinyl acetate, polyvinyl chloride, unsaturated polyester resins, polyacrylates, polyurethanes, epoxy resins, phenolic resins, alkyd resins and mixtures thereof, said undercoat containing 0.05 to 10 % by weight of at least one antioxidant of the type of the sterically hindered phenols.
The antioxidant is preferablly a compound which contains at least one group of formula I
R
HO
~CH3~3C
wherein R is hydrogen, mei:hyl or tert-butyl, preferably wherein R is tert-butyl.
The antioxidant is preferably an ester of b-(3,5-di-tert-butyl-4-hydroxyphenyl~ropionic acid, more particularly a compound of formula II
t-C4H6 HO ~ ~ CFizCHZC00- R~ II
t-CQH9 wherein n is 1, 2 or 4 and, when n =: l, RI is CgH,~, and when n = 2, Rt is -(CH2)6- or -CH2CH20CH2CHZOCH2CH2-, and, when n = 4, R1 is -(CHZ)4C , The antioxidant is also preferably a compound of formula III
H H H
z Rz C Rz III
j~~~~9~~
Wood surfaces which are exposed to sunlight are damaged in particular by the UV light present in the sunlight. The polymeric constituents of the wood are degraded, so that the surface undergoes roughening and discolouration. As a consequence, attack by microorganisms, especially fungi, giives rise to further damage.
The conventional method of protecting wood against light-induced degradation, without having to forgo the attractive appearance of the wood surface, is to coat the wood with a colourless varnish which contains a light stabiliser, especially a UV
absorber.
Investigations have also bec,n made to determine whether the addition of an antioxidant to the protective coatings rein:Forces the effect of the light stabiliser in the wood varnish.
According to D.N.S. Hon et al., J. Appl. Polymer Sci. 30 (1985), 1439, no, or only an insignificant effect, is obtained.
The addition of phenolic antioxidanla to wood varnishes is known. For example, US patent specification 3285855 discloses the colour stabilisation of furniture varnishes based on acid-curable urea/formaldehyde alkyd resins by adding 0.2% by weight of a phenolic antioxidant.
Wood protective coatings which contain a UV absorber, an antioxidant and an insecticide are disclosed in the publication of the JF' patent application Sho 59-115 805, published July 4, 1984.
It has now been found that antioxidants of the type of the the sterically hindered phenols have a marked stabilising acaion against light-induced degradation if they are applied, without the addition of a light stabiliser, to an undercoat which penetrates the surface of the wood, and the wood is then provided with a top coat, which top coat may contain a light stabiliser.
Accordingly, the invention ,relates to a method of protecting wood surfaces against light-induced degradation by treatment with a) an undercoat which penetrates thc: surface of the wood and which does not contain a light stabiliser, said undercoat comprising an aqueous or organic solvent, or said solvent containing a binder selecaed frorr~ the group consisting of alkyd resins, modified alkyd resins, acrylic resins, polyester resins, drying oils, phenolic resins, nitrocellulose resins and mixtures thereof, and b) one or more top coats, comprising a resin selected from the group consisting of nitrocellu-lose, polyvinyl acetate, polyvinyl chloride, unsaturated polyester resins, polyacrylates, polyurethanes, epoxy resins, phenolic resins, alkyd resins and mixtures thereof, said undercoat containing 0.05 to 10 % by weight of at least one antioxidant of the type of the sterically hindered phenols.
The antioxidant is preferablly a compound which contains at least one group of formula I
R
HO
~CH3~3C
wherein R is hydrogen, mei:hyl or tert-butyl, preferably wherein R is tert-butyl.
The antioxidant is preferably an ester of b-(3,5-di-tert-butyl-4-hydroxyphenyl~ropionic acid, more particularly a compound of formula II
t-C4H6 HO ~ ~ CFizCHZC00- R~ II
t-CQH9 wherein n is 1, 2 or 4 and, when n =: l, RI is CgH,~, and when n = 2, Rt is -(CH2)6- or -CH2CH20CH2CHZOCH2CH2-, and, when n = 4, R1 is -(CHZ)4C , The antioxidant is also preferably a compound of formula III
H H H
z Rz C Rz III
j~~~~9~~
wherein R2 is hydrogen, methyl or tert-butyl, preferably wherein R2 is tert-butyl.
The antioxidant is also preferably a compound of formula IV
R3 / Rs IV
CH3 ~ CH3 C4H9-t wherein R3 is a group -CH2 ~ ~ OH
CaHs_t The antioxidant is also preferably a compound of formula V
OH
t-C4H9 /
CH3 - C - CH2C00 ~ R4 V
m C4H9-t OH
wherein either m is 1 and R4 is methyl, or rn is 2 and R4 is -CH2CI-I2-.
The antioxidant is also preferably a compound of formula VI
The antioxidant is also preferably a compound of formula IV
R3 / Rs IV
CH3 ~ CH3 C4H9-t wherein R3 is a group -CH2 ~ ~ OH
CaHs_t The antioxidant is also preferably a compound of formula V
OH
t-C4H9 /
CH3 - C - CH2C00 ~ R4 V
m C4H9-t OH
wherein either m is 1 and R4 is methyl, or rn is 2 and R4 is -CH2CI-I2-.
The antioxidant is also preferably a compound of formula VI
t ~4H9 (~4H9_t HO ~ ~ C ~ ~ OH VI
I
R~
Rs Rs Rs Rio wherein RS and Rto are hydrogen or tert-butyl, R6 and R9 are hydrogen or methyl, R~ is hydrogen or methyl and Rs is hydrogen or Ct-C4alkyl.
The antioxidant is also preferably 3,5-di-tert-butyl-4-hydroxytoluene.
The following compounds are illustrative of antioxidants which are suitable for use in the method of this invention:
1. Alkylated monophenols, for example 2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-butyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol, 2-(a-methylcyclohexyl)-4,6-dimethylphenol, 2,6-dioctadecyl-4-methylphenol, 2,4,6-tri-eyclohexylphenol, 2,6-di-tert-butyl-4-methoxymethylphenol, 2,6-di-nonyl-4-methyl-phenol.
2. Alkylated hydroduinones, for example 2,6-di-tert-butyl-4-methoxyphenol, 2,5-di-tert-butylhydroquinone, 2,5-di-ten-amylhydroquinone, 2,6-diphenyl-4-octadecyloxy-phenol.
3. Hydroxylated thiodiphenyl ethers, for example 2,2'-thiobis(6-tent-butyl-4-methyl-phenol), 2,2'-thiobis(4-octylphenol), 4,4'-thiobis(6-tert-butyl-3-methylphenol), 4,4'-thiobis(6-tert-butyl-2-methylphenol).
4. Alkylidenebisphenols, for example 2,2'-methylenebis(6-tent-butyl-4-methylphenol), 2,2'-methylenebis(6-tent-butyl-4-ethylphenol), 2,2'-methylenebis[4-methyl-6-(a-methyl-eyclohexyl)phenol], 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-methylene-bis(6-nonyl-4-methylphenol), 2,2'-methylenebis(4,6-di-tert-butylphenol), 2,2'-ethylidene-bis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(6-tent-butyl-4-isobutylphenol), 2,2'-methylenebis[6-(a-methylbenzyl)-4-nonylphenol], 2,2'-methylenebis(6-(a,a-dimethyl--, benzyl)-4-nonylphenol], 4,4'-methylenebis(2,6-di-tert-butylphenol), 4,4'-methylene-bis(6-tert-butyl-2-methylphenol), 1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol, 1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 1,1-bis(5-tert-butyl-4-hydroxy-2-methyl-phenyl)-3-n-dodecylmercaptobutane, ethylene glycol bis[3,3-bis(3'-tert-butyl-4'-hydroxy-phenyl)butyrate], bis(3-tert-butyl-4-hydroxy-5-methylphenyl)dicyclopentadiene, bis[2-(3'-tert-butyl-2'-hydroxy-5'-methylbenzyl)-6-tent-butyl-4methylphenyl]
terephthalate.
5. Benzyl compounds, for example 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, bis(3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, isooctyl 3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate, bis(4-tent-butyl-3-hydroxy-2,6-dimethylbenzyl) dithiolterephthalate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-Iris(4-tent-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, dioctadecyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, calcium salt of monoethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl)isocyanurate.
I
R~
Rs Rs Rs Rio wherein RS and Rto are hydrogen or tert-butyl, R6 and R9 are hydrogen or methyl, R~ is hydrogen or methyl and Rs is hydrogen or Ct-C4alkyl.
The antioxidant is also preferably 3,5-di-tert-butyl-4-hydroxytoluene.
The following compounds are illustrative of antioxidants which are suitable for use in the method of this invention:
1. Alkylated monophenols, for example 2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-butyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol, 2-(a-methylcyclohexyl)-4,6-dimethylphenol, 2,6-dioctadecyl-4-methylphenol, 2,4,6-tri-eyclohexylphenol, 2,6-di-tert-butyl-4-methoxymethylphenol, 2,6-di-nonyl-4-methyl-phenol.
2. Alkylated hydroduinones, for example 2,6-di-tert-butyl-4-methoxyphenol, 2,5-di-tert-butylhydroquinone, 2,5-di-ten-amylhydroquinone, 2,6-diphenyl-4-octadecyloxy-phenol.
3. Hydroxylated thiodiphenyl ethers, for example 2,2'-thiobis(6-tent-butyl-4-methyl-phenol), 2,2'-thiobis(4-octylphenol), 4,4'-thiobis(6-tert-butyl-3-methylphenol), 4,4'-thiobis(6-tert-butyl-2-methylphenol).
4. Alkylidenebisphenols, for example 2,2'-methylenebis(6-tent-butyl-4-methylphenol), 2,2'-methylenebis(6-tent-butyl-4-ethylphenol), 2,2'-methylenebis[4-methyl-6-(a-methyl-eyclohexyl)phenol], 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-methylene-bis(6-nonyl-4-methylphenol), 2,2'-methylenebis(4,6-di-tert-butylphenol), 2,2'-ethylidene-bis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(6-tent-butyl-4-isobutylphenol), 2,2'-methylenebis[6-(a-methylbenzyl)-4-nonylphenol], 2,2'-methylenebis(6-(a,a-dimethyl--, benzyl)-4-nonylphenol], 4,4'-methylenebis(2,6-di-tert-butylphenol), 4,4'-methylene-bis(6-tert-butyl-2-methylphenol), 1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol, 1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 1,1-bis(5-tert-butyl-4-hydroxy-2-methyl-phenyl)-3-n-dodecylmercaptobutane, ethylene glycol bis[3,3-bis(3'-tert-butyl-4'-hydroxy-phenyl)butyrate], bis(3-tert-butyl-4-hydroxy-5-methylphenyl)dicyclopentadiene, bis[2-(3'-tert-butyl-2'-hydroxy-5'-methylbenzyl)-6-tent-butyl-4methylphenyl]
terephthalate.
5. Benzyl compounds, for example 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, bis(3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, isooctyl 3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate, bis(4-tent-butyl-3-hydroxy-2,6-dimethylbenzyl) dithiolterephthalate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-Iris(4-tent-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, dioctadecyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, calcium salt of monoethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl)isocyanurate.
6. Acylaminophenols, for example 4-hydroxylauranilide, 4-hydroxystearanilide, 2,4-bis(octylmercapto)-6-(3,5-di-tert-butyl-4-hydroxyanilino)-s-triazine, octyl N-(3,5-di-tert-butyl-4-hydroxyphenyl)carbamate.
7. Esters of 13-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid with mono-or polyhydric alcohols, e.g. with methanol, octadecanol, 1,6-hexanediol, neopentyl glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, thiodiethylene glycal, N,N'-bis(hydroxyethyl)oxalodiamide.
8. Esters of 13-(5-tent-butyl-4-hydroxy-3-methylphen~propionic acid with mono-or polyhydric alcohols, e.g. with methanol, diethylene glycol, octadecanol, triethylene glycol, 1,6-hexaaediol, pentaerythritol, neopentyl glycol, tris(hydroxyethyl) isocyanurate, thiodiethylene glycol, N,N'-bis(hydroxyethyl)oxalodiamide.
9. Esters of J3-(3 5-dicyclohexyl-4-hydroxyphe~l)propionic acid with mono- or poly-hydric alcohols, e.g. with methanol, diethylene glycol, octadecanol, triethylene glycol, 1,6-hexanediol, pentaerythritol, neopentyl glycol, tris(hydroxyethyl) isocyanurate, thiodiethylene glycol, N,N'-bis(hydroxyethyl)oxalodiamide.
10. Amides of B-(3,5-di-tert-but~vdroxyphe~l)propionic acid e.g. N,N'-bas(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylenediamine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)trimethylenediamine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine.
In specific cases it may be useful to use two or more antioxidants.
The undercoat shall penetrate the surface of the wood, and should therefore be of relatively low viscosity. In the simplest case, the undercoat is a solution of the antioxidant in an organic solvent. Exemplary of useful solvents for the purpose are aliphatic hydrocarbons such as specific petroleum fractions. Further suitable solvents are aromatic hydrocarbons such as toluene or xylene; alcohols such as methanol, ethanol, isopropanol or butanol; esters such as ethyl acetate or butyl acetate; or ketones such as acetone, methyl ethyl ketone or methyl isobutyl ketone. These solvents evaporate at room temperature and therefore do not remain in the wood. It is, however, also possible to add high boiling liquids which remain in the wood, for example higher alkanols, glycols, glycol ethers, glycol esters or polyglycols. The undercoat may also contain a binder conventionaliy used for protective wood coatings. Exemplary of suitable binders are alkyd resins and modified alkyd resins, autocrosslinking or non-autocrosslinking acrylic resins, polyester resins, drying oils, phenolic resins, nitrocellulose or mixtures thereof.
The undercoat may also contain one or more phosphates which synergise the action of the antioxidants. Illustrative examples of such phosphates are:
triphenyl phosphate, diphenylalkyl phosphate, phenyldialkyl phosphate, tris(nonylphenyl) phosphate, trilauryl phosphate, trioctadecyl phosphate, distearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphate, diisodecyl pentaerythritol diphosphite, bis(2,4-di-tent-butylphenyl) pentaerythritol diphosphite, tristearyl sorbitol triphosphite.
Tris-(2,4-di-tv;rt-butylphenyl) phosphate is particularly preferred.
The undercoat may also contain preservatives such as fungicides or insecticides.
Exemplary of useful fungicides are tributyltin oxide, phenylmercury salts, copper naphthenate, 1-chloronaphthalene or pentachlorophenol. Exemplary of useful insecticides are DDT, dieldrin, lindane, parathion or phoxime.
Further ingredients which may be present in the undercoat are minor amounts of accelerators (hardeners) for the binders, dyes or pigments.
The undercoat consists mainly of the solvent and contains typically 0.05 to 10 %, preferably 0.1 to 5 %, of the antioxidant. It can further contain 0.1 to 5 %
by weight of a phosphite.
The undercoat can be applied to the wood by conventional techniques, for example by impregnating, spreading or spraying.
The undercoat may also be an aqueous coating. Instead of the organic solvent, the vehicle may then consist of water or a mixture of water and a water-soluble organic solvent. The antioxidant and the other components may be dissolved or dispersed in this vehicle.
Any coating composition suitable for coating wood may be used as top coat. It will normally contain a binder, dissolved or dispersed in an organic solvent or in water or a mixture of water and solvent. The binder may typically be a surface coating resin which dries in the air or hardens at room temperature. Exemplary of such binders are nitrocellulose, polyvinyl acetate, polyvinyl chloride, unsaturated polyester resins, polyacrylates, polyurethanes, epoxy resins, phenolic resins, and especially alkyd resins.
The binder may also be a mixture of different surface coating resins. Provided the binders are curable binders, they are normally used together with the hardener and/or accelerator.
Typical examples of organic solvents which may suitably be used for the coating compositions are aliphatic, aromatic or cycloaliphatic hydrocarbons, alcohols, esters, ketones or chlorinated hydrocarbons.
Water/solvent mixtures are typically mixtures of water and lower alcohols, glycols or glycol ethers.
The top coat may also be a radiation-curable, solvent-free formulation of photopolymerisable compounds. Illustrative examples are mixtures of acrylates or methacrylates, unsaturated polyester/styrene mixtures or mixtures of other ethylenically unsaturated monomers or oligomers.
The top coat may contain a soluble dye and/or a pigment and/or a filler. The pigment may be an organic, inorganic or metallic pigment. The filler may be typically kaolin, calcium carbonate or aluminium silicate. Preferably the top coat is a clear varnish, i.e. it contains no undissolved components.
~\
-g-Although the top coat which contains the antioxidant affords good protection against light, it is advantageous to add a light stabiliser to the top coat.111ustrative examples of suitable light stabilisers are the following compounds:
1. 2-(2'-Hydroxvphenyl)benzotriazoles for example the 5'-methyl, 3',5'-di-tert-butyl, 5'-tert-butyl, 5'-(1,1,3,3-tetramethylbutyl), 5-chloro-3',5'-di-tert-butyl, 5-chloro-3'-tert-butyl-5'-methyl, 3'-sec- butyl-5'-tert-butyl, 4'-octoxy, 3',5'-di-tert-amyl and 3',5'-bis(a,a-dimethylbenzyl) derivative, the octyl ester of 3-(5-chlorobenzotriazol-2-yl)-4-hydroxy-5-tert-butylphenylpropionic acid or the polyglycol 300 ester of 3-(benzo-triazol-2-yl)-4-hydroxy-5-tert-butylphenylpropionic acid.
2. 2-Hydrox benzophenones for example the 4-hydroxy, 4-methoxy, 4-octoxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2',4'-trihydroxy and 2'-hydroxy-4,4'-dimethoxy derivative.
3. Esters of substituted and unsubstituted benzoic acids for example, 4-tent-butylphenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoylresorcinol, bis(4-tent-butylbenzoyl)-resorcinol, benzoylresorcinol, 2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxy- benzoate and hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate.
4Acrylates, for example ethyl a-cyano-~i,~3-diphenylacrylate, isooctyl a-cyano-(3,(3-diphenylacrylate, methyl a-carbomethoxycinnamate, methyl a-cyano-~i-methyl-p-methoxy-cinnamate, butyl a-cyano-(3-methyl-p-methoxy- cinnamate, methyl a-carbo-methoxy-p-methoxycinnamate and N-(p-carbomethoxy-~3-cyanovinyl)-2-methylindoline.
5. Nickel compounds for example nickel complexes of 2,2'-thio-bis(4-(1,1,3,3-tetra-methylbutyl)phenol], such as the 1:1 or 1:2 complex, with, or without additional ligands such as n-butylamine, triethanolamine or N-cyclohexyldiethanolamine, nickel dibutyl-dithiocarbamate, nickel salts of 4-hydroxy-3,5-di-tert-butylbenzyl-phosphonic acid monoalkyl esters, e.g. of the methyl or ethyl ester, nickel complexes of ketoximes, e.g. of 2-hydroxy-4-methyl-phenyl undecyl ketoneoxime, nickel complexes of 1-phenyl-4-lauroyl-5-hydroxypyrazole, with or without additional ligands. -6. Sterically hindered amines, for example bis(2,2,6,6-tetramethylpiperidyl) sebacate, bis(1,2,2,6,6-pentamethylpiperidyl) sebacate, bis(1,2,2,6,6-pentamethylpiperidyl) ~~~~,~5 n-butyl-3,5-di-tert-butyl-4-hydroxy-benzylmalonate, the condensation product of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, the condensation product of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-tert-octylamino-2,6-dichloro-1,3,5-triazine, tris(2,2,6,6-tetramethyl-4-piperidyl)nitrilotriacetate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butane-tetraoate, 1,1'-(1,2-ethanediyl)bis-(3,3,5,5-tetramethylpipexazinone).
7. Oxalvl diamides for example 4,4'-dioctyloxyoxanilide, 2,2'-dioctyloxy-5,5'-di-tert-butaxanilide, 2,2'-didodecyloxy-5,5'-di-tert-butoxanilide, 2-ethoxy-2'-ethyloxanilide, N,N'-bis(3-dimethylaminopropyl)oxalamide, 2-ethoxy-5-tert-butyl-2'-ethyloxanilide and its mixture with 2-ethoxy-2'-ethyl-5,4'-di-tert-butoxanilide and mixtures of ortho- and para-methoxy-disubstituted oxanilides and mixtures of o-and p-ethoxydisubstituted oxanilides.
8. 2-(2-Hydroxy>ahenyl)-1 3 5-triazines for example 2,4,6-tris(2-hydraxy-4-octyloxy-phenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octylaxy-phenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2,4-dihydroxy-phenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine.
Light stabilisers of classes 1, 6 and 8 are preferred.
The addition of a mixture of a UV absorber of classes 1, 2, 3, 4, 7 and 8, preferably 1 and 8, together with a sterically hindered amine, far example of class 6 above, is particularly effective.
The amount of light stabiliser, or the sum of the light stabilisers, used is preferably 0.1 to % by weight, based on the solids content.
The top coat may further contain conventional additives of coating technology, for example levelling agents, thixotropic agents, flame retardants, antioxidants or soluble dyes.
The application of the top coat is made by conventional techniques of wood coating, for example by spreading, spraying or impregnating.
~~~~9~~
The top coat can be applied in several coats so that it has a sufficient layer thickness. How thick the top coat shall be will depend on the intended end use.
The following Examples illustrate the invention in detail. Parts and percentages are by weight.
The following stabilisers are used in the Examples:
AO-1 octadecyl-(3-(3,5-di-tart-butyl-4-hydroxyphenyl)propionate AO-2 [i-(3,S-di-tart-butyl-4-hydroxyphenyl)propionate of pentaerythritol AO-3 bis[(3-(3,5-di-tart-butyl-4-hydroxyphenyl)propionate] of triethylene glycol AO-4 2,4,6-iris(~,5-di-tart-butyl-4-hydroxybenzyl)1,x,5-trimethylbenzene AO-S bis[[i-bis(3-tent-butyl-4-hydroxyphenyl)butyrate] of ethylene glycol AO-6 bis(2-hydroxy-3-tart-butyl-5-methylphenyl)methane LS-1 j3-[3-(benzotriazol-2-yl)-4-hydroxy-5-tent-butylphenyl]propionate of polyethylene glycol 300 LS-2 bis(1,2,2,6,6-pentamethylpiperid-4-yl)sebacate P-1 iris(2,4-di-tart-butylphenyl)phosphite Example 1 An undercoat is prepared from 27 parts of an alkyd resin (Jagalyd Antihydro~, E. Jager KG, 60 % solution in white spirit) .
1 part of an accelerator (Antihydro Trockner~, E. Jager KG) 3 parts of 2-ethoxyethanol 0.5 part of an anti-skinning agent (Ascinin~ P, Bayer AG) of »~x~~~
In specific cases it may be useful to use two or more antioxidants.
The undercoat shall penetrate the surface of the wood, and should therefore be of relatively low viscosity. In the simplest case, the undercoat is a solution of the antioxidant in an organic solvent. Exemplary of useful solvents for the purpose are aliphatic hydrocarbons such as specific petroleum fractions. Further suitable solvents are aromatic hydrocarbons such as toluene or xylene; alcohols such as methanol, ethanol, isopropanol or butanol; esters such as ethyl acetate or butyl acetate; or ketones such as acetone, methyl ethyl ketone or methyl isobutyl ketone. These solvents evaporate at room temperature and therefore do not remain in the wood. It is, however, also possible to add high boiling liquids which remain in the wood, for example higher alkanols, glycols, glycol ethers, glycol esters or polyglycols. The undercoat may also contain a binder conventionaliy used for protective wood coatings. Exemplary of suitable binders are alkyd resins and modified alkyd resins, autocrosslinking or non-autocrosslinking acrylic resins, polyester resins, drying oils, phenolic resins, nitrocellulose or mixtures thereof.
The undercoat may also contain one or more phosphates which synergise the action of the antioxidants. Illustrative examples of such phosphates are:
triphenyl phosphate, diphenylalkyl phosphate, phenyldialkyl phosphate, tris(nonylphenyl) phosphate, trilauryl phosphate, trioctadecyl phosphate, distearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphate, diisodecyl pentaerythritol diphosphite, bis(2,4-di-tent-butylphenyl) pentaerythritol diphosphite, tristearyl sorbitol triphosphite.
Tris-(2,4-di-tv;rt-butylphenyl) phosphate is particularly preferred.
The undercoat may also contain preservatives such as fungicides or insecticides.
Exemplary of useful fungicides are tributyltin oxide, phenylmercury salts, copper naphthenate, 1-chloronaphthalene or pentachlorophenol. Exemplary of useful insecticides are DDT, dieldrin, lindane, parathion or phoxime.
Further ingredients which may be present in the undercoat are minor amounts of accelerators (hardeners) for the binders, dyes or pigments.
The undercoat consists mainly of the solvent and contains typically 0.05 to 10 %, preferably 0.1 to 5 %, of the antioxidant. It can further contain 0.1 to 5 %
by weight of a phosphite.
The undercoat can be applied to the wood by conventional techniques, for example by impregnating, spreading or spraying.
The undercoat may also be an aqueous coating. Instead of the organic solvent, the vehicle may then consist of water or a mixture of water and a water-soluble organic solvent. The antioxidant and the other components may be dissolved or dispersed in this vehicle.
Any coating composition suitable for coating wood may be used as top coat. It will normally contain a binder, dissolved or dispersed in an organic solvent or in water or a mixture of water and solvent. The binder may typically be a surface coating resin which dries in the air or hardens at room temperature. Exemplary of such binders are nitrocellulose, polyvinyl acetate, polyvinyl chloride, unsaturated polyester resins, polyacrylates, polyurethanes, epoxy resins, phenolic resins, and especially alkyd resins.
The binder may also be a mixture of different surface coating resins. Provided the binders are curable binders, they are normally used together with the hardener and/or accelerator.
Typical examples of organic solvents which may suitably be used for the coating compositions are aliphatic, aromatic or cycloaliphatic hydrocarbons, alcohols, esters, ketones or chlorinated hydrocarbons.
Water/solvent mixtures are typically mixtures of water and lower alcohols, glycols or glycol ethers.
The top coat may also be a radiation-curable, solvent-free formulation of photopolymerisable compounds. Illustrative examples are mixtures of acrylates or methacrylates, unsaturated polyester/styrene mixtures or mixtures of other ethylenically unsaturated monomers or oligomers.
The top coat may contain a soluble dye and/or a pigment and/or a filler. The pigment may be an organic, inorganic or metallic pigment. The filler may be typically kaolin, calcium carbonate or aluminium silicate. Preferably the top coat is a clear varnish, i.e. it contains no undissolved components.
~\
-g-Although the top coat which contains the antioxidant affords good protection against light, it is advantageous to add a light stabiliser to the top coat.111ustrative examples of suitable light stabilisers are the following compounds:
1. 2-(2'-Hydroxvphenyl)benzotriazoles for example the 5'-methyl, 3',5'-di-tert-butyl, 5'-tert-butyl, 5'-(1,1,3,3-tetramethylbutyl), 5-chloro-3',5'-di-tert-butyl, 5-chloro-3'-tert-butyl-5'-methyl, 3'-sec- butyl-5'-tert-butyl, 4'-octoxy, 3',5'-di-tert-amyl and 3',5'-bis(a,a-dimethylbenzyl) derivative, the octyl ester of 3-(5-chlorobenzotriazol-2-yl)-4-hydroxy-5-tert-butylphenylpropionic acid or the polyglycol 300 ester of 3-(benzo-triazol-2-yl)-4-hydroxy-5-tert-butylphenylpropionic acid.
2. 2-Hydrox benzophenones for example the 4-hydroxy, 4-methoxy, 4-octoxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2',4'-trihydroxy and 2'-hydroxy-4,4'-dimethoxy derivative.
3. Esters of substituted and unsubstituted benzoic acids for example, 4-tent-butylphenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoylresorcinol, bis(4-tent-butylbenzoyl)-resorcinol, benzoylresorcinol, 2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxy- benzoate and hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate.
4Acrylates, for example ethyl a-cyano-~i,~3-diphenylacrylate, isooctyl a-cyano-(3,(3-diphenylacrylate, methyl a-carbomethoxycinnamate, methyl a-cyano-~i-methyl-p-methoxy-cinnamate, butyl a-cyano-(3-methyl-p-methoxy- cinnamate, methyl a-carbo-methoxy-p-methoxycinnamate and N-(p-carbomethoxy-~3-cyanovinyl)-2-methylindoline.
5. Nickel compounds for example nickel complexes of 2,2'-thio-bis(4-(1,1,3,3-tetra-methylbutyl)phenol], such as the 1:1 or 1:2 complex, with, or without additional ligands such as n-butylamine, triethanolamine or N-cyclohexyldiethanolamine, nickel dibutyl-dithiocarbamate, nickel salts of 4-hydroxy-3,5-di-tert-butylbenzyl-phosphonic acid monoalkyl esters, e.g. of the methyl or ethyl ester, nickel complexes of ketoximes, e.g. of 2-hydroxy-4-methyl-phenyl undecyl ketoneoxime, nickel complexes of 1-phenyl-4-lauroyl-5-hydroxypyrazole, with or without additional ligands. -6. Sterically hindered amines, for example bis(2,2,6,6-tetramethylpiperidyl) sebacate, bis(1,2,2,6,6-pentamethylpiperidyl) sebacate, bis(1,2,2,6,6-pentamethylpiperidyl) ~~~~,~5 n-butyl-3,5-di-tert-butyl-4-hydroxy-benzylmalonate, the condensation product of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, the condensation product of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-tert-octylamino-2,6-dichloro-1,3,5-triazine, tris(2,2,6,6-tetramethyl-4-piperidyl)nitrilotriacetate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butane-tetraoate, 1,1'-(1,2-ethanediyl)bis-(3,3,5,5-tetramethylpipexazinone).
7. Oxalvl diamides for example 4,4'-dioctyloxyoxanilide, 2,2'-dioctyloxy-5,5'-di-tert-butaxanilide, 2,2'-didodecyloxy-5,5'-di-tert-butoxanilide, 2-ethoxy-2'-ethyloxanilide, N,N'-bis(3-dimethylaminopropyl)oxalamide, 2-ethoxy-5-tert-butyl-2'-ethyloxanilide and its mixture with 2-ethoxy-2'-ethyl-5,4'-di-tert-butoxanilide and mixtures of ortho- and para-methoxy-disubstituted oxanilides and mixtures of o-and p-ethoxydisubstituted oxanilides.
8. 2-(2-Hydroxy>ahenyl)-1 3 5-triazines for example 2,4,6-tris(2-hydraxy-4-octyloxy-phenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octylaxy-phenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2,4-dihydroxy-phenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine.
Light stabilisers of classes 1, 6 and 8 are preferred.
The addition of a mixture of a UV absorber of classes 1, 2, 3, 4, 7 and 8, preferably 1 and 8, together with a sterically hindered amine, far example of class 6 above, is particularly effective.
The amount of light stabiliser, or the sum of the light stabilisers, used is preferably 0.1 to % by weight, based on the solids content.
The top coat may further contain conventional additives of coating technology, for example levelling agents, thixotropic agents, flame retardants, antioxidants or soluble dyes.
The application of the top coat is made by conventional techniques of wood coating, for example by spreading, spraying or impregnating.
~~~~9~~
The top coat can be applied in several coats so that it has a sufficient layer thickness. How thick the top coat shall be will depend on the intended end use.
The following Examples illustrate the invention in detail. Parts and percentages are by weight.
The following stabilisers are used in the Examples:
AO-1 octadecyl-(3-(3,5-di-tart-butyl-4-hydroxyphenyl)propionate AO-2 [i-(3,S-di-tart-butyl-4-hydroxyphenyl)propionate of pentaerythritol AO-3 bis[(3-(3,5-di-tart-butyl-4-hydroxyphenyl)propionate] of triethylene glycol AO-4 2,4,6-iris(~,5-di-tart-butyl-4-hydroxybenzyl)1,x,5-trimethylbenzene AO-S bis[[i-bis(3-tent-butyl-4-hydroxyphenyl)butyrate] of ethylene glycol AO-6 bis(2-hydroxy-3-tart-butyl-5-methylphenyl)methane LS-1 j3-[3-(benzotriazol-2-yl)-4-hydroxy-5-tent-butylphenyl]propionate of polyethylene glycol 300 LS-2 bis(1,2,2,6,6-pentamethylpiperid-4-yl)sebacate P-1 iris(2,4-di-tart-butylphenyl)phosphite Example 1 An undercoat is prepared from 27 parts of an alkyd resin (Jagalyd Antihydro~, E. Jager KG, 60 % solution in white spirit) .
1 part of an accelerator (Antihydro Trockner~, E. Jager KG) 3 parts of 2-ethoxyethanol 0.5 part of an anti-skinning agent (Ascinin~ P, Bayer AG) of »~x~~~
1.3 parts of a preservative (Traetex~ 293, Acima AG) 67.2 parts of white spirit.
This undercoat has a solids content of ca. 17 %. To this undercoat is added a solution of each of the antioxidants listed in Table 1 in 10 parts of xylene.
The undercoat is applied with a brush to pinewood boards (30x10x1.5 cm) and dried for 24 hours at room temperature.
The top coat is an alkyd resin based glaze of the following composition:
53 parts of an alkyd resin as 60% solution in white spirit (Jagalyd~
Antihydro) 11 parts of a thixotropic agent as 50% solution in white spirit (Jagalyd~
Antihydro Thix N) 1.9 parts of an accelerator (Antihydro Trockner ~, Jager) 33.4 parts of white spirit K 60 0.3 part of an anti-skinning agent (Ascinin~ P, Bayer AG) 0.4 part of a preservative (Exkin~ II, Servo BV) This glaze contains no pigment and has a solids content (binder) of ca. 38 %.
If the top coat contains light stabilisers, these are predissolved in a small amount of xylene.
The top coat is applied with a brush in three layers to the boaxds treated with the undercoat. Between the application of each layer, the specimen is allowed to dry for 24 hours at room temperature.
The specimens are exposed to weathering near Zurich in the open at 45°
south. The surface gloss and fungus infestation of the surface are assessed after 11 months.
This undercoat has a solids content of ca. 17 %. To this undercoat is added a solution of each of the antioxidants listed in Table 1 in 10 parts of xylene.
The undercoat is applied with a brush to pinewood boards (30x10x1.5 cm) and dried for 24 hours at room temperature.
The top coat is an alkyd resin based glaze of the following composition:
53 parts of an alkyd resin as 60% solution in white spirit (Jagalyd~
Antihydro) 11 parts of a thixotropic agent as 50% solution in white spirit (Jagalyd~
Antihydro Thix N) 1.9 parts of an accelerator (Antihydro Trockner ~, Jager) 33.4 parts of white spirit K 60 0.3 part of an anti-skinning agent (Ascinin~ P, Bayer AG) 0.4 part of a preservative (Exkin~ II, Servo BV) This glaze contains no pigment and has a solids content (binder) of ca. 38 %.
If the top coat contains light stabilisers, these are predissolved in a small amount of xylene.
The top coat is applied with a brush in three layers to the boaxds treated with the undercoat. Between the application of each layer, the specimen is allowed to dry for 24 hours at room temperature.
The specimens are exposed to weathering near Zurich in the open at 45°
south. The surface gloss and fungus infestation of the surface are assessed after 11 months.
Table 1 Antioxidant Light stabiliser60 glossfungus infestation in the in the top coat on the surface undercoat t~ 1>
none none no longer100 %
measurable none 1 % LS-1 40 % 70 %
1 % LS-2 1 % AO-1 none 73 % 20 %
1 % AO-1 1 % LS-1 73 % 5 %
1 % LS-2 1) Amount based on solids content of the coat Example 2 An undercoat (impregnation) is prepared from 2 parts of an alkyd resin (Jagalyd~ Antihydro, 60% solution in white spirit) 1 part of accelerator (Jagalyd~ Antihydro Trockner) 3 parts of 2-ethoxyethanol 0.2 part of an anti-skinning agent (Luactim~ M, BASF AG) 1.3 parts of a preservative (Traetex~ 293, Acima AG) 52:5 parts of white spirit 1~5 parts of xylene.
This undercoat has a solids content of ca. 17 %. To the undercoat is added a solution of each of the antioxidants listed in Table 2 in an amount of 1 %, based on solids (= 0.17 part, based on the undercoat).
The undercoat is applied with a brush to pinewood boards and dried for 24 hours at room temperature. The glaze described in Example 1 is used as top coat and is applied in 3 layers with a brush as described in Example 1.
The specimens are exposed to weathering in the open for 4.5 months in Basel at 45° south.
none none no longer100 %
measurable none 1 % LS-1 40 % 70 %
1 % LS-2 1 % AO-1 none 73 % 20 %
1 % AO-1 1 % LS-1 73 % 5 %
1 % LS-2 1) Amount based on solids content of the coat Example 2 An undercoat (impregnation) is prepared from 2 parts of an alkyd resin (Jagalyd~ Antihydro, 60% solution in white spirit) 1 part of accelerator (Jagalyd~ Antihydro Trockner) 3 parts of 2-ethoxyethanol 0.2 part of an anti-skinning agent (Luactim~ M, BASF AG) 1.3 parts of a preservative (Traetex~ 293, Acima AG) 52:5 parts of white spirit 1~5 parts of xylene.
This undercoat has a solids content of ca. 17 %. To the undercoat is added a solution of each of the antioxidants listed in Table 2 in an amount of 1 %, based on solids (= 0.17 part, based on the undercoat).
The undercoat is applied with a brush to pinewood boards and dried for 24 hours at room temperature. The glaze described in Example 1 is used as top coat and is applied in 3 layers with a brush as described in Example 1.
The specimens are exposed to weathering in the open for 4.5 months in Basel at 45° south.
Before and after weathering, the Yellowness Index (YI) of the surface of the specimens is measured in accordance with ASTM D 1 925. The increase in the YI after weathering is indicated in Table 2.
Table 2 Antioxidant Increase in the YI after in the undercoat *~ 4.5 months weathering none 38.5 1 % AO-2 32.5 1 % AO-3 33.2 0.5 % AO-2 + 0.5 % P-1 34.2 0.5%AO-4+0.5%P-1 35.2 *> Amount based on the solids content of the undercoat Example 3 A 0.5 % solution of the antioxidant in xylene is used as undercoat (impregnation). This undercoat is applied with a brush to the wood and then the specimens are dried for 24 hours at room temperature.
The glaze described in Example 1 is used as top coat and applied as in Example 1.
The specimens are exposed to weathering in the open for 4.5 months in Basel at 45° south.
The Yellowness Index (YI) is measured before and after weathering.
Table 2 Antioxidant Increase in the YI after in the undercoat *~ 4.5 months weathering none 38.5 1 % AO-2 32.5 1 % AO-3 33.2 0.5 % AO-2 + 0.5 % P-1 34.2 0.5%AO-4+0.5%P-1 35.2 *> Amount based on the solids content of the undercoat Example 3 A 0.5 % solution of the antioxidant in xylene is used as undercoat (impregnation). This undercoat is applied with a brush to the wood and then the specimens are dried for 24 hours at room temperature.
The glaze described in Example 1 is used as top coat and applied as in Example 1.
The specimens are exposed to weathering in the open for 4.5 months in Basel at 45° south.
The Yellowness Index (YI) is measured before and after weathering.
Table 3 Antioxidant in Increase in YI
the undercoat after 4.S months none 37.1 AO-2 32.8 AO-S 34.8 AO-6 33.4 AO-4 + O.S % P-1 32.1 Example 4 The undercoats and top coats described in Example 1 are used and applied to pinewood boards as described therein.
The specimens are exposed to weathering in a xenon light accelerated weathering test (cycle: 102 min. dry exposure, 18 min. sprinkling). The 60° gloss of the surface of the specimens is measured according to DIN 67 S30 at specific intervals. The results are reported in Table 4.
Antioxidant in % gloss after exposure time of the undercoat *> 262 h S33 h 1039 h 1302 h none 43 S1 22 10 1 % AO-1 S3 64 S9 . 30 1 % AO-3 62 68 70 51 *> Amount based on the solids content of the undercoat
the undercoat after 4.S months none 37.1 AO-2 32.8 AO-S 34.8 AO-6 33.4 AO-4 + O.S % P-1 32.1 Example 4 The undercoats and top coats described in Example 1 are used and applied to pinewood boards as described therein.
The specimens are exposed to weathering in a xenon light accelerated weathering test (cycle: 102 min. dry exposure, 18 min. sprinkling). The 60° gloss of the surface of the specimens is measured according to DIN 67 S30 at specific intervals. The results are reported in Table 4.
Antioxidant in % gloss after exposure time of the undercoat *> 262 h S33 h 1039 h 1302 h none 43 S1 22 10 1 % AO-1 S3 64 S9 . 30 1 % AO-3 62 68 70 51 *> Amount based on the solids content of the undercoat
Claims (21)
1. A method of protecting wood surfaces against light-induced degradation by treatment with a) an undercoat which penetrates tile surface of the wood and which does not contain a light stabiliser, said undercoat comprising an aqueous or organic solvent, or said solvent containing a binder selected from the group consisting of alkyd resins, modified alkyd resins, acrylic resins, polyester resins, drying oils, phenolic resins, nitrocellulose resins and mixtures thereof, and b) one or more top coats, comprising a resin selected from the group consisting of nitrocellulose, polyvinyl acetate, polyvinyl chloride, unsaturated polyester resins, polyacrylates, polyurethanes, epoxy resins, phenolic resins, alkyd resins and mixtures thereof, said undercoat containing 0.05 to 10 % by weight of at least one antioxidant of the type of the sterically hindered phenols.
2. A method according to claim 1 wherein the antioxidant is a compound which contains at least one group of formula I
wherein R is hydrogen, methyl or tert-butyl.
wherein R is hydrogen, methyl or tert-butyl.
3. A process according to claim 2, wherein the antioxidant contains a group of formula I, wherein R is tert-butyl.
4. A process according to claim 1, wherein the antioxidant is an ester of b-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid.
5. A process according to claim 4, wherein the antioxidant is a compound of formula II
wherein n is 1, 2 or 4 and, when n = 1, R1 is C8H17, and when n = 2, R1 is -(CH2)6- or -CH2CH2OCH2CH2OCH2CH2-, and, when n = 4, R1 is ---(CH2)4C.
wherein n is 1, 2 or 4 and, when n = 1, R1 is C8H17, and when n = 2, R1 is -(CH2)6- or -CH2CH2OCH2CH2OCH2CH2-, and, when n = 4, R1 is ---(CH2)4C.
6. A process according to claim 1, wherein the antioxidant is a compound of formula III
wherein R2 is hydrogen, methyl or tert-butyl.
wherein R2 is hydrogen, methyl or tert-butyl.
7. A process according to claim 6, wherein R2 is tert-butyl.
8. A process according to claim 1, wherein the antioxidant is a compound of formulaIV
wherein R3 is a group
wherein R3 is a group
9. A process according to claim 1, wherein the antioxidant is a compound of formulaV
wherein either m is 1 and R4 is methyl, or m is 2 and R4 is -CH2CH2-.
wherein either m is 1 and R4 is methyl, or m is 2 and R4 is -CH2CH2-.
10. A process according to claim 1, wherein the antioxidant is a compound of formulaVI
wherein R5 and R10 are hydrogen or tert-butyl, R6 and R9 are hydrogen or methyl, R7 is hydrogen or methyl and R8 is hydrogen or C1-C4alkyl.
wherein R5 and R10 are hydrogen or tert-butyl, R6 and R9 are hydrogen or methyl, R7 is hydrogen or methyl and R8 is hydrogen or C1-C4alkyl.
11. A process according to claim 1, wherein the antioxidant is 3,5-di-tert-butyl-4-hydroxytolu-ene.
12. A process according to claim 1, wherein the undercoat contains a binder and/or a high boiling liquid, selected from the group consisting of the higher alkanols, glycols, glycol ethers, glycol esters,and polygylcols, or a mixture thereof.
13. A process according to claim 1, wherein the undercoat contains a phosphite.
14. A process according to claim 1, wherein the undercoat contains tris(2,4-di-tert-butylphenyl)phosphite.
15. A process according to claim 1, wherein the undercoat contains a preservative.
16. A process according to claim 1, wherein the top coat is a clear varnish.
17. A process according to claim 1, wherein the top coat contains an alkyd resin based binder.
18. A process according to claim 1, wherein the top coat contains one or more light stabilisers.
19. A process according to claim 1, wherein the top coat contains a UV
absorber and a sterically hindered amine as light stabilisers.
absorber and a sterically hindered amine as light stabilisers.
20. A protective coating for wood comprising a) an undercoat which penetrates the surface of the wood and which does not contain a light stabiliser, said undercoat comprising an aqueous or organic solvent, or said solvent containgin a binder selected from the group consisting of alkyd resins, modified alkyd resins, acrylic resins, polyester resins, drying oils, phenolic resins, nitrocellulose resins and mixtures thereof, and b) one or more top coats, comprising a resin selected from the group consisting of nitrocellulose, polyvinyl acetate, polyvinyl chloride, unsaturated polyester resins, polyacrylates, polyurethanes, epoxy resins, phenolic resins, alkyd resins and mixtures thereof, said undercoat containing 0.05 to 10% by weight of at least one antioxidant of the type of the sterically hindered phenols.
21. A protective coating for wood, wherein the undercoat is a solution of a phenolic antioxidant in an organic solvent.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH26590 | 1990-01-29 | ||
| CH265/90-0 | 1990-01-29 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2034952A1 CA2034952A1 (en) | 1991-07-30 |
| CA2034952C true CA2034952C (en) | 2001-07-03 |
Family
ID=4183070
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002034952A Expired - Fee Related CA2034952C (en) | 1990-01-29 | 1991-01-25 | Protective coating for wood against damage by light containing undercoating comprising sterically hindered phenols |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0440580B1 (en) |
| JP (1) | JP3143751B2 (en) |
| CA (1) | CA2034952C (en) |
| DE (1) | DE59104830D1 (en) |
| ES (1) | ES2069258T3 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102005046345B4 (en) * | 2004-09-21 | 2009-08-06 | Institut für Holztechnologie Dresden gGmbH | Wood materials, process for their preparation |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI93431C (en) * | 1990-12-05 | 1995-04-10 | Aho Jyrki | Parquet structure and method of its production |
| DE59808737D1 (en) * | 1997-08-19 | 2003-07-24 | Ciba Sc Holding Ag | Stabilizers for powder coatings |
| DE10030658C1 (en) | 2000-06-23 | 2002-01-03 | Trespa Int Bv | Flame retardant resin coating |
| DE102005041214A1 (en) * | 2005-08-31 | 2007-03-01 | Votteler Lackfabrik Gmbh & Co. Kg | Production of veneered mouldings involves press-moulding a combination of base material and a face veneer coated with a coherent layer of viscous impregnating material which hardens during moulding |
| ATE428549T1 (en) * | 2005-11-04 | 2009-05-15 | Ciba Holding Inc | COLOR STABILIZATION OF CORK AND DYED WOODS THROUGH THE COMBINED USE OF INORGANIC AND ORGANIC UV ABSORBERS |
| EP2181818A3 (en) | 2008-10-28 | 2012-08-22 | IHD Institut für Holztechnologie Dresden gGmbH | Method for manufacturing wood fibre substances and wood fibre substances with lower emissions of volatile VOC |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3285855A (en) * | 1965-03-11 | 1966-11-15 | Geigy Chem Corp | Stabilization of organic material with esters containing an alkylhydroxy-phenyl group |
| GB1419768A (en) * | 1972-04-27 | 1975-12-31 | Ici Ltd | Polyurethanes |
| JPS59115805A (en) * | 1982-12-24 | 1984-07-04 | 日本農薬株式会社 | Protective agent for wood |
-
1991
- 1991-01-21 DE DE59104830T patent/DE59104830D1/en not_active Expired - Fee Related
- 1991-01-21 ES ES91810047T patent/ES2069258T3/en not_active Expired - Lifetime
- 1991-01-21 EP EP91810047A patent/EP0440580B1/en not_active Expired - Lifetime
- 1991-01-25 CA CA002034952A patent/CA2034952C/en not_active Expired - Fee Related
- 1991-01-29 JP JP03047269A patent/JP3143751B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102005046345B4 (en) * | 2004-09-21 | 2009-08-06 | Institut für Holztechnologie Dresden gGmbH | Wood materials, process for their preparation |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0440580A3 (en) | 1992-07-01 |
| JP3143751B2 (en) | 2001-03-07 |
| EP0440580A2 (en) | 1991-08-07 |
| EP0440580B1 (en) | 1995-03-08 |
| CA2034952A1 (en) | 1991-07-30 |
| JPH05253539A (en) | 1993-10-05 |
| ES2069258T3 (en) | 1995-05-01 |
| DE59104830D1 (en) | 1995-04-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0943665B1 (en) | Stabilization of wood substrates | |
| US5350449A (en) | Coating materials stabilized against light-induced degradation | |
| US5322868A (en) | Coating compositions stabilized against light, heat and oxygen | |
| US5707690A (en) | Protective coating for wood | |
| US5238745A (en) | Protective coating for wood | |
| CA2034952C (en) | Protective coating for wood against damage by light containing undercoating comprising sterically hindered phenols | |
| BRPI0618213A2 (en) | color stabilization of cork and colored woods by the combined use of inorganic and organic UV absorbers | |
| US5171328A (en) | Stabilizer-containing wood stains | |
| KR102377945B1 (en) | Functional wood protection paint composition and manufacturing method thereof | |
| CA2382621C (en) | Stabilization of wood substrates | |
| US5302497A (en) | Photosensitive organic polymeric material containing UV absorbers | |
| WO2005005114A1 (en) | Stabilization of wood with sterically hindered amine-n-oxyls or hydroxyls and transparent inorganic pigments | |
| Turkoglu et al. | Research Article The Effects of Natural Weathering on Color Stability of Impregnated and Varnished Wood Materials | |
| Zhu | Photoprotection of wood using metal acetylacetonates | |
| JP2018176500A (en) | Method for protecting outdoor wood material and wood material protected by the method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |