WO2006013146A1

WO2006013146A1 - Treatment and coating for wood

Info

Publication number: WO2006013146A1
Application number: PCT/EP2005/053399
Authority: WO
Inventors: Prof. Dr. Holger Militz; Dr. Carsten Mai; Oliver Weigenand
Original assignee: Georg-August Universität Göttingen
Priority date: 2004-07-29
Filing date: 2005-07-14
Publication date: 2006-02-09
Also published as: DE102004036918A1

Abstract

The invention relates to a fungicidal wood treatment with an amino-modified silicon of general formula R5 - A<sub

Description

International new patent application: Wood preservatives and tarnish, Georg-August-Universität Göttingen, Militz, Mai, Weigenand

Protection and compensation for HoLz

The present invention relates to wood preservatives, and the use of wood preservatives, which is suitable to make wood and other substances based on cellulose and / or lignin preserved, especially against weathering and microorganisms. Furthermore, this invention relates to methods for the compensation of lignocellulosic materials by using the wood preservatives, as well as with the Holzschutzmittehi invention treated lignocellulosic materials, especially wood.

State of the art

It is known to increase the resistance of wood to the weather by a coating of paints and colors. However, dimensional changes of the wood, for example due to swelling and shrinkage due to water absorption, caused by external moisture variations, cause the flaking of such paints. 99

It is also known to protect the visual appearance and the resistance of wood against harmful microorganisms, such as fungal fungus or white rot, brown rot and soft rot by impregnation with a mixture of arsenic, ionic copper and chromium VI.

At this wood preservative is disadvantageous that at least chromium and arsenic are harmful to health and the environment.

Furthermore, water-soluble wood preservatives are known which consist of a quaternary ammonium, for example Didecylpolyoxethylammoniumborat (benzalkonium chloride). On these wood preservatives is disadvantageous that they can be deposited only superficially on this due to their immediate binding to wood.

Other biocidal active ingredients are 3-iodo-2-propynyl butylcarbamate (EPBC) or triazoles (propiconnazole, tebuconnazole).

The known organic wood preservatives are used for the use classes 1, 2 and 3 according to DIN EN 351 and do not lead to a water repellency of the wood, so that the tendency of the wood to absorb water and thus the dimensional stability remains unchanged.

To reduce the water absorption of wood, compounds based on oils, fats and waxes (paraffins, silicones) were mainly used.

Known wood preservatives which are used for hydrophobing and have a content of silicon compounds are also known. Thus, JP 2002348567A describes wood preservatives which consist of a mixture of different alkoxysilanes, including amino-containing alkoxysilanes.

No. 6,294,608 discloses aqueous emulsions for treating mineral building materials and wood with a mixture of silanes which are provided with alkyl and alkoxy groups or aminoalkyl groups. Polysiloxane compounds having at least one amino group are not disclosed. EP 0716127 discloses organopolysiloxanes and their aqueous mixtures which can be used inter alia for the hydrophobization of cellulose products or as additives for paints and coatings. As the nitrogen-containing radical, a ureido-alkyl group may be contained on the organopolysiloxane.

EP 0716128 discloses aminoalkyl-alkoxysilanes which can be used inter alia for the hydrophobization of cellulose products or as additives for paints and varnishes. Polysiloxanes are not disclosed here.

US 2002/0026881 describes a composition for the hydrophobization of surfaces which contains, inter alia, silicone. Amine-containing silicones are not specified.

The known organic wood preservatives are used for the use classes 1 to 3 according to DIN EN 351 and give the wood no or an improvement in need of hydrophobing. A desired hydrophobization with the present invention results in that the tendency of the wood to water absorption is reduced and thus the dimensional stability is maintained even when changing the water content of the environment.

Furthermore, the agents used hitherto for hydrophobing do not provide effective protection against degradation of wood by fungi. The combination of these properties can be achieved so far only by a two-stage treatment of the wood.

An example of the combination of a hydrophobizing substance with a biocidal substance is the so-called Royal method. In this two-stage process, the wood is first soaked in a first step with an organic copper salt (Cu-HDO) or an inorganic copper salt, then as a second step impregnation in oil is carried out to prevent the leaching of the biocidal copper.

Furthermore, DE 101 22 626 A1, DE 199 39 866 A, US Pat. No. 6,294,608 Bl, DE 4241 727 A1 and US Pat. No. 4,541,936 disclose organopolysiloxanes in aqueous or organic composition for the treatment of paper and / or wood or wood products , In contrast to the present invention, however, the aforementioned documents do not recognize the fungicidal action of inventive amino-modified silicones with primary, secondary and / or tertiary amino groups. The amino-modified silicones having a quaternary amino group which are particularly preferred according to the invention are not used as wood preservatives in the prior art.

General description of the invention

Compared to the known prior art, it is the object of the present invention to provide a protective agent for wood and other materials based on lignocellulose, with which the resistance to weathering and microbial infestation can be improved.

Generally, the present invention relates to protectants that can be used for wood and other lignocellulosic materials to increase their resistance, for example, to microbial degradation and / or weathering, such as sunlight (UV), rain, and other variations in humidity. The agent according to the invention is used as a protective agent for lignocellulosic materials.

In another aspect, the present invention relates to a process for improving the properties of wood or lignocellulosic materials by treatment with a preservative of the invention. In a further aspect, the present invention relates to wood or other lignocellulosic materials which have been treated with preservatives of the invention.

The protective agent to be used according to the invention for wood and wood-based materials, chipboard, medium-density fiberboard, Oriented Strand boards (OSB), paper, cardboard, lignocellulose-based insulation boards, plywood, veneers and packaging material containing biodegradable compounds, hereinafter referred to as lignocellulosic materials contains an amino-modified silicone.

The protective agent to be used in the present invention has an amino-modified silicone, which is also referred to as an aminosilicone, and improves after application to the Surface of the lignocellulosic material and / or in its volume, for example by impregnation, its weather resistance and resistance to microbial attack.

Furthermore, the amino silicone to be used according to the invention has a high resistance to washing out.

As a further advantage, the protective agent to be used according to the invention enables a method for applying, for. As an impregnation, in a single process step.

The protective agent to be used according to the invention has a backbone of straight-chain, optionally branched structural units of silicon dioxide whose free side chains have substituents selected from the group consisting of alkyl, alkoxy and amine, wherein at least one amine substituent on the amino-modified silicone is available. The amine substituent may be a primary, secondary, tertiary or quaternary amine, in the case of several amine substituents also identical or different of the amine substituents. The following aminoalkyl radicals are mentioned by way of example: H ₂ N (CH ₂ ) ₂ -; H ₂ N (CH ₂ ) ₂ NH (CH ₂ ) ₃ -; (CH ₂ ) ₂ N (CH ₂ ) -; H ₂ N (CH ₂ ) ₅ -; H (NHCH ₂ CH ₂ ) ₃ -; n- C ₄ H ₉ NHCH ₂ CH ₂ NHCH ₂ CH ₂ -.

The number of siloxane units having a SiC-donated radical having a primary, secondary, tertiary or quaternary amino group is up to 50% of the siloxane units, preferably 0.1 to 20%, more preferably 0.2 to 10%.

The molecular weight of the aminosilicones for protecting agents according to the invention is for example between about 500 and about 500,000, preferably between about 2,000 and about 200,000.

An example of a preservative to be used according to the invention is given by the following general formula I:

(I) R5 -A _n -B _m -R 6 where A =.

The substituents R 1 to R 4 are each independently selected for each structural unit from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, iso-butyl and amine, at least one radical being an amine substituent which is a primary, secondary, tertiary or quaternary amine; the substituents R 1 to R 4 may also be saturated or unsaturated, straight-chain, cyclic or branched hydrocarbons having up to 20 carbon atoms. It is preferred that three of the hydrocarbon radicals are at least monounsaturated, such as, for example, vinyl, allyl or butadienyl radicals. As a further possibility, three of the hydrocarbon radicals may be cycloaliphatic, for example a cyclohexyl radical, or aromatic, such as, for example, a phenyl, naphthyl or an alkylaryl radical, such as tosyl radicals, or aralkyl radicals, such as a benzyl radical. The hydrocarbon radicals can also have further functional groups, such as an alkoxy or hydroxyl group corresponding to R5 or R6, a carboxylic acid group or epoxy group. As an example, Lauryl is called.

m is 1 to 100, preferably 2 to 10; n is 1 to 1000, preferably 10 to 500;

R5 and R6 are selected from hydroxyl, alkyl or alkoxy groups, in particular from

Hydroxymetibyl, hydroxyethyl, dihydroxyethyl, hydroxypropyl, dihydroxypropyl,

Trihydroxypropyl, hydroxyisopropyl, hydroxybutyl, dihydroxybutyl, trihydroxybutyl,

Hydroxyisobutyl, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, methoxy, ethoxy,

Propoxy, isopropoxy, butoxy and / or isobutoxy.

Alternatively, one or more of R 1 to R 4 may also have substituents corresponding to R 5 and R 6.

The structural elements A and B can be arranged in a straight-chain or branched manner, wherein the order or arrangement of the structural elements can also be freely selected. Exemplary are: R5 -A _n -B _m -A _m -B _n -A _n -R 6, R 5 - (AB) _n - A _m - B _n - and R6 R5 - A _n - B _m - A _n - R 6.

Preferably, R1 to R3 are alkyl, more preferably methyl and / or ethyl, most preferably methyl, and R4 is an amine, most preferably a quaternary amine. Preferred quaternary amine substituents are -XN ⁺ (R1) ₂ (RZ), wherein X is a (CHa) chain with 0-10 methylene units and R1 and R2 as defined above, preferably methyl, R2 is a long-chain alkyl or fatty acid chain 8 to 20 carbon atoms, preferably lauryl, and n = 2 to 10, m = 1 to 2.

As a further embodiment, the protective agent according to the invention contains a mixture of different amino-modified silicones of the general formula I.

When the aminosilicone to be used as protectants according to the invention contains condensable groups bonded directly to silicon, it may be used in admixture with an organopolysiloxane or a mixture thereof, the organopolysiloxane having at least three Si-bonded hydrogen atoms per molecule. Optionally, it is possible to add a catalyst to condense the condensable groups bonded directly to silicon.

Preferably in mixture with the aminosilicone to be used organopolysiloxanes having at least three hydrogen atoms per molecule bonded to Si are those of the formula π

(CH ₃ ) ₃ SiO (SiR 7 ₂ O) _p Si (CH ₃ ) ₃ (TL),

where R7 is hydrogen, a methyl, ethyl or phenyl radical, p is from 10 to 500, with the proviso that at most one hydrogen atom is bonded to one silicon atom and that the ratio of R7 is ₂ SiO-structural units in which both R4 are hydrocarbon radicals, to the structural units with Si-bonded hydrogen is 3: 1 to 1: 4. Preferably, R4 is methyl when it is not hydrogen. Further, it is preferable that Si-bonded hydrogen is present in a proportion of 0.01 to 0.2% by weight based on the aminosilicone.

Alternatively or in addition to the mixture with one or more organopolysiloxanes, such as those according to formula π, the aminosilicone according to the invention in admixture with at least one trialkoxy- or tetraalkoxysilane used singly or in combination when the aminosilicone contains condensable groups bonded directly to silicon. Optionally, an additional catalyst may be included for condensing the condensable groups bonded directly to silicon in the mixture.

Trialkoxy- or tetraalkoxysilanes preferably to be used in admixture with the aminosilicone are those of the formula πia or DIb:

RSi (OR1) ₃ (ffla),

Si (ORI) ₄ (IEb) ₃ or partial hydrolysates of trialkoxy- or tetraalkoxysilanes having up to 10 silicon atoms each

Partial hydrolyzate, wherein R and Rl are as defined for formula I. The compounds IIIa and / or IIIb are preferably used in a ratio of 1 to 20 wt .-%, based on the inventive

Amino silicone, used.

Carboxylic acid salts of tin or zinc can be used as catalysts, for example, where hydrocarbon radicals can be bonded directly to tin, such as di-n-butyltin dilaurate, tin octoate, di-2-ethyltin dilaurate, di-n-butyltin di-2-ethylhexoate, di-2- Ethylhexyltin di-2-ethylhexoate, di-butyl or di-octyltin diacylates. As catalysts it is also possible to use alkoxy titanates, for example butyl titanate and triethanolamine titanate, and also zirconium compounds or mixtures of one or more of the abovementioned catalysts.

The catalyst or the catalyst mixture is preferably used in amounts of from 1 to 10% by weight, based on aminosilicone.

The combination of aminosilicone, which has condensable groups, with the aforementioned organopolysiloxanes and / or with trialkoxy- or tetraalkoxysilanes, optionally with additional catalyst for accelerating the condensation in the protective agent according to the invention, leads to crosslinking. The crosslinking results in a protective agent that is more strongly embedded in or bonded to the lignocellulosic material. This is particularly the case when the protective means are the aforementioned Having components in a formulation, so that they cross-link with each other during or after the impregnation process, for example, during a tempering step, thus leading to a high molecular weight protective agent with amino groups, which is contained in the material.

The protective agent to be used according to the invention may contain a solubilizer and / or an emulsifier, which leads to an increase in stability of the aqueous mixture, which may be a solution or emulsion. Suitable solubilizers or emulsifiers are, in particular, compounds from the group which include amino-modified silicones according to formula I, quaternary fatty alcohol derivatives, in particular a quaternary fatty amine ethanolate, polyalcohols, in particular propylene glycol, ethylene glycol or butyl diglycol and organic solvents such as ethanol, (iso) propanol, THF, DMSO, dioxane, aliphatic and / or chlorinated hydrocarbons.

In a further embodiment, the protective agent to be used according to the invention is used in a mixture with a boron compound, for example borax, borate and / or boric acid.

In a further embodiment, the protective agent to be used according to the invention is used in conjunction with a soluble copper compound, for example copper salt (copper (H) oxide, copper sulfate, copper hydroxide carbonate, bis (N-cyclohexyldiazeniumdioxy) copper). It is also possible to use the protective agent of the invention in admixture with an aforementioned boron compound and an aforementioned copper compound.

In a further embodiment, the protective agent to be used in accordance with the invention is used in conjunction with organic biocidal compounds, for example triazoles (azaconazole, cyproconazole, propiconazole, tebuconazole, TCMTB), phenylsulfamides (dichlorofluidide, tolylfluanid), carbamates (IPBC, carbendazim), aromatic fungicides ( ortho-phenylphenol, chlorothalonil) and other fungicides (bethoxazine, isothiazolone), synthetic pyrethroids (permethrin, cypermethrin, cyfluthrin, deltamethrin, silafluofen) and other insecticides (imidacloprid, flufenoxuron, chlorpyrifos, fenoxycarb). The combination of the protective agent to be used according to the invention with copper and / or boron compounds and / or organic biocidal protective agents can be used both in a one-stage process and in a two-stage process. Single-stage processes are, for example, brushing, dipping or impregnating formulations with protective agents according to the invention in organic solvents or as an aqueous emulsion. In the case of two-stage processes, preferably the organic, biocidal protective agent is first applied, for example by brushing, dipping or impregnating, and then the protective agent according to the invention.

In a preferred embodiment, the inventive use of the protective agent is carried out in emulsion, for example in aqueous emulsion. For the preparation and / or stabilization of such an (aqueous) emulsion, an emulsifier may be added, wherein the emulsifier may also be an amino-modified silicone of the general formula I.

The use of the protective agent can be carried out by brushing, spraying or other application methods on wood, or by impregnation, for example by vacuum followed by overpressure. In this case, the protective agent to be used according to the invention, optionally with an additional boron compound and / or an additional copper compound and / or at least one additional organic, biocidal protective agent, consist of one or more compounds of the formula I and are preferably used in the form of an aqueous emulsion. As aqueous emulsions so-called microemulsions and / or macroemulsions can be used.

To fix the protective agent to be used according to the invention in wood or other lignocellulosic materials, a drying step may be carried out, for example one at a temperature of between 10 and 200 ^° C., preferably between 60 and 120 ^° C. The treated material may also be subjected to freeze-drying under vacuum and / or or dried by use of microwaves.

A preferred method for applying protective agents to be used according to the invention is impregnation, which comprises the following process steps: The substrate to be impregnated is in a pressure-resistant impregnating reactor for about 5 minutes to 2 hours, preferably about 15 minutes to 1 hour, in particular about half an hour, initially a pressure of 10 to 500 mbar abs, preferably about 50 to 200 mbar abs., In particular about 100 mbar abs., Exposed. This pressure is maintained and the substrate immersed in the protective agent to be used or its aqueous solution or emulsion or covered. The pressure is then for about 0.5 to 4 hours to about 1, 5 to 20 bar abs., Preferably about 5 to 15 bar abs., In particular about 10 to 12 bar abs., Increased. Then the pressure can be adjusted to ambient pressure. The substrate is removed from the impregnating solution or emulsion, it is drained off and the vacuum and drackimpregnated substrate can be fed to the drying.

The drying of the substrate before and / or after the impregnation can be achieved by technical drying or by free-air drying, preferably up to a wood moisture content of about 10 to 20%, preferably about 13 to 17%. A conventional industrial drying is achieved by heating to about 50 to 120 ⁰ C over a period of about 4 hours to 4 weeks, preferably about 6 hours to 3 weeks. The principle of technical drying is the coordination of humidity and temperature on each other to reduce the formation of cracks. As a variant of the technical drying, the hot steam drying can be used, are used at the temperatures above the boiling point, ie above 100 ⁰ C at ambient pressure. The hot steam drying can be carried out in a temperature range from above 100 ^° C. to, for example, 140 ^° C., preferably up to about 130 ^° C., more preferably up to 121 ^° C. over a period of about 2 hours to 2 weeks, more preferably about 6 to 180 hours be performed. The suitable drying temperature and drying time depends on the dimensions of the substrate to be dried and can be determined by a person skilled in the art. The initial humidity is about 100% and is reduced in the course of drying.

It is believed that the mechanism by which the preservative to be used in the present invention makes wood and other lignocellulosic materials more resistant to weathering and / or variations in moisture content is at least partially due to the surface, preferably the layers adjacent to the surface be rendered hydrophobic to the total volume of the wood or lignocellulosic material. For wood, it is believed that the preservative to be used in the present invention results in reduced moisture absorption, which in turn results in less dimensional variation with changing ambient humidity. Thus, the protective agent of the invention therefore leads to a better dimensional stability of wood, because it penetrates into the cell wall of the wood and remains there permanently. As a result, even when dry, the wooden cell wall resembles a preswollen state and therefore absorbs less water than untreated wood. The penetration of the protective agent to be used according to the invention is achieved above all with so-called microemulsions, for example with particle sizes of 10 to 100 nm. Such microemulsions can penetrate into the pores of wood cell walls and also between cellulosic strands, so that the further uptake of water is permanently reduced. In this way, the dimensional change, for example, the shrinkage in the drying of wood is reduced as the moisture content of the environment decreases.

In the case of macroemulsions, for example with a particle size of greater than 50 to 100 nm, it is assumed that the protective agent to be used according to the invention at least partially coats the inner surfaces of wood cells and penetrates into pores of the wood cell wall.

The content of the protective agent to be used according to the invention on at least one amine substituent, which may be one or more identical or different substituents from the group of primary, secondary, tertiary or quaternary amine, on the one hand can provide a better association of the protective agent with the lignocellulosic material, on the other hand confer a certain antimicrobial effect. The antimicrobial action is inhibitory or biocidal, in particular with respect to fungi, so that lignocellulosic material treated with the protective agent according to the invention, for example wood, is less affected by discoloring, for example, fungi or mold, or destructive fungi (white rot, brown rot) and therefore has a greater resistance to having microbial degradation.

Detailed description of the invention The present invention will now be explained in more detail by way of examples, in which the amino silicones (AS) to be used according to the invention are numbered consecutively.

Brief description of the figures:

Figure 1 shows a graphic representation of the water absorption in percent of treated with the invention Aminosilikon compounds and comparative compounds

Pine wood samples during a 4 hour immersion test,

FIG. 2 shows the water absorption in percent of aminosilicone according to the invention,

Compounds treated pine wood specimens and two comparison compounds treated pine wood specimens and untreated wood during a dip test over 24

hours

FIG. 3 shows the weight loss in percent of treated and untreated beech wood samples after 12 weeks of incubation with Trametes versicolor,

FIG. 4 shows the weight loss in percent of treated and untreated pine wood samples after 12 weeks of incubation with Coniophoraputeana,

FIG. 5 shows the infestation of the surface of treated and untreated pine wood specimens by mold fungi at an ambient moisture content of about 95% over a period of 7 weeks,

FIG. 6 shows cracking, surface fungus infestation with wood exposed directly to solar radiation to the south, and infestation by mold on the sun-facing, north-facing surface of treated and untreated pine wood specimens after natural weathering in the period from September 2003 to April 2004

Figure 7 shows the weight gain of pine wood by treatment with the inventive protection products compared to water and the anti-shrinkage / anti- swelling effect according to the invention retardants at 20 ⁰ C between 0 and 65% and between 0 and 100% wood moisture, FIG. 8 shows the weight increase of beech wood and anti-SchwmdVanti swelling effect as in FIG. 7,

FIG. 9 shows the course of the weight losses of ground pine wood samples which were treated untreated (control) or with an aminosilicone (AS 3) or a conventional flame retardant (impralit F3 / 66) during a thermogravimetric analysis,

Figure 10 shows the reduction in weight loss of aminosilicone-treated pine wood samples during a flame test compared to untreated pine wood samples.

FIG. 11 shows the reduction of the burn-up distance (afterburning) of aminosilicone-treated pine wood samples during a flame test after removal of the ignition source in comparison to untreated pine wood samples and

FIG. 12 shows the weight loss of aminosilicone-treated pine sapwood samples by means of rotten rot fungi in contact with the soil according to the European prestandard ENv 807 over a period of 8 or 16 weeks.

Example 1: Impregnation with aminosilicones to reduce the water absorption of

pinewood

For impregnation, wood samples of the dimensions 5 × 10 × 30 mm (radial, tangential, longitudinal) were impregnated under vacuum and subsequent pressure.

For impregnation, the test pieces were deaerated in a vacuum of less than 100 mbar for about one hour and then kept in an aqueous emulsion of inventive preservative and comparative emulsions under a pressure of 6 bar for about 2 hours. The concentration of the aminosilicones in the impregnating emulsion was about 5% by weight. This was followed by drying at ambient temperature for 12 hours. For the determination of the water-repellent (hydrophobing) surface properties of the wood samples, the Wasseraufhahrne was measured in a dip test. The results of the determination of Wasseraufhahrne over 4 hours are shown in Figure 1, those over a period of 24 hours in Figure 2. The water absorption was determined by weighing the individual wood samples before and after the dive time.

The aminosilicone compounds (AS) 1 to 3 according to the invention used in FIGS. 1 and 2 are:

AS 1: Amino silicone according to formula I (primary amine) with R 1, R 2 and R ₃ = -CH ₃ , R 4 = - (CH ₂ ) ₃ -NH 2; R5 and R6 = -CH _3. The number of Diorganosüoxanstniktureinheiten is about 300 - 400, the viscosity of the pure compound at about 3000 mPas. The proportion of amino groups is 0.25%. The formulation used was a macroemulsion with fatty alcohol ethanolates as emulsifiers.

AS 2: Amino silicone according to formula I (quaternary ammonium) with R 1, R 2 and R ₃ = -CH ₃ , R 4 = - (CH ₃ ) ₂ N (CH ₃ ) ₂ X, wherein X is lauryl; R5 and R6 = -CH _3. The molecular weight is about 6500, with each molecule having two quaternary ammonium groups. The formulation used was a macroemulsion with fatty alcohol ethanolates as emulsifiers.

AS 3: aminosilicone (primary amine) with R 1 - R ₃ = -CH ₃ ; R 4 = - (CH ₂ ) ₃ -NH- (CH ₂ ) 2 -NH 2;

R5, R6 = -OH. The molecular weight is about 150,000, the viscosity of the pure chemical at about 3000 mPa s. The proportion of amino groups is 0.12%. The wording used was one

Macroemulsion (particle size of the emulsion approx. 200 microns).

For comparison, silicone Sl (epoxy-functional polydimethylsiloxane, the epoxy group (CHOCH ₂ ) is bonded to Si as - (CH ₂ ) ₃ -O-CH ₂ -CHOHCH ₂ ), S2 (monomeric silane, Wacker Chemie BS1701) and silicone S3 ( Silane / siloxane mixture, Wacker Chemie BS 1702), each carrying a neat aminogram, and untreated wood used as control K.

The results shown in FIGS. 1 and 2 show that the aminosilicones AS 1 to AS 3 according to the invention each have the water uptake compared to the Comparative compounds S2 and S3 or untreated wood K during a dipping time of 4 h and 24 h significantly reduced, while the silicone Sl gives a similar high hydrophobicity as the compounds of the invention.

Example 2: Impregnation of beech wood to increase the resistance against holzbaubende mushrooms

For proof of the antiperspirant effect of aminosilicones according to the invention, beech wood samples impregnated with protection agent according to the invention were exposed to degradation by Trametes versicolor (white rot). The impregnation was carried out according to Example 1. To determine the increase in the resistance of the wood samples compared to the white rot fungus, the mass loss was determined after 12 weeks. The concentration of the aminosilicones in the impregnating emulsion was about 5% by weight.

The samples of beech wood had the dimensions 5 × 10 × 30 mm, radial, tangential, longitudinal, the aminosilicones AS 1, AS 2, AS 3 were the compounds given in Example 1.

AS 4 is an aminosilicone according to formula I (primary amine) with R 1, R 2 and R ₃ = -CH ₃ , R 4 = - (CH ₂ ) ₃ -NH (CH ₂ ) ₂ NH ₂ ; R5 and R6 = -OH. The number of Diorganosüoxanstruktureinheiten was about 200 - 300, the viscosity of the pure compound at about 2000 mPas. The proportion of amino groups lab at 0.20%. The formulation used was a macroemulsion with ready alcohol ethanolates as emulsifiers.

The silicones S1 to S3 are polydimethylsiloxanes without an amino or ammonium group as comparative compounds according to Example 1.

W denotes a wax emulsion, K denotes untreated wood.

The results are shown in Figure 3 and it is clearly visible that the wood samples treated with the aminosilicone according to the invention have the least mass loss. It should be noted that the small size of the specimens (significantly smaller than EN 113) and the duration of the fungal degradation test of 12 weeks represent very extreme experimental conditions that allow the degradation by Trametes versicolor (white rot). In particular, the duration of 12 weeks is very long compared to conventional tests. Therefore, it can be concluded from the test results that the protective effect the aminosilicones according to the invention not only based on their hydrophobizing effect, but also on a fungus-inhibiting effect.

Example 3: Impregnation of pine wood to increase resistance to brown rot

Pine wood samples (5 × 10 × 30 mm, radial, tangential, longitudinal), which had been impregnated with aminosilicones AS 1 to AS 4 according to the invention, comparative compounds S1 to S3 or wax emulsion W according to Example 1, and untreated wood (marked K) were used wood-destroying brown rot fungus Coniophora puteana exposed for 12 weeks. Mass loss was determined by weighing the samples before and after the incubation period.

The measurement results are shown in Figure 4, in which it is clear that the Arninosilikone invention AS 1 to AS 4 compared to the comparative compounds Sl to S3, wax emulsion W or untreated wood K lead to a significantly reduced mass loss of treated pine wood samples.

Example 4: Impregnation with aminosilicones to reduce the infestation by mold fungi

To demonstrate the inhibiting effect of aminosilicones according to the invention against infestation by molds, impregnated pine wood samples having the dimensions 15 × 20 × 50 mm (radial, tangential, longitudinal) were stored in a closed container above a water surface with wood preservatives according to the invention in order to determine a wood moisture near the fiber saturation point of the Wood (about 30%). The impregnation was carried out according to Example 1 in aqueous solutions with 5 wt .-% of the respective silicone compound. In addition, forest soil was added to the water to increase the density of mold spores in the container. The air of the container was continuously circulated by means of a fan.

At intervals of one week each, the infestation by mold on the surface of the samples was optically evaluated on an arbitrary scale from 0 to 3, where 0 indicates no infestation, 1 low infestation, 2 middle infestation and 3 severe infestation. The results of the evaluation are shown graphically in FIG. The compounds used are the untreated control sample K, S2 and S3 as compounds without Amino group, the aminosilicones AS 1, AS 2, AS 3 according to the invention, as defined above and

AS 5: aminosilicone according to formula I (primary amine) with R 1, R 2 and R ₃ = -CH ₃ , R 4 = - (CH ₂ ) ₃ -NH 2; R5 and R6 = -CH _3; The number of Diorganosüoxanstniktureinheiten is about 300 - 400, the viscosity of the pure compound at about 3000 mPas. The proportion of amino groups is 0.25%; the formulation used was a microemulsion with fatty alcohol ethoxylates as emulsifiers, as well as

AS 6: an aminosilicone according to formula I (quaternary ammonium) with R 1, R 2 and R ₃ = -CH ₃ , R 4 = - (CH ₂ ) ₃ N (CH ₃ ) ₂ X, wherein X is lauryl; R5 and R6 = -CH _3. The molecular weight is about 3000, the viscosity of the pure compound is 550-950 mPas. Each molecule has two quaternary ammonium groups. The formulation used was in the form of a 50% solution of AS 6 in propylene glycol, which was then used in aqueous dilution with a final concentration of 5 wt .-% AS 5 for impregnation.

As a further reference substance B, the conventional organic biocidal wood preservative Bethoxazine was used.

The results clearly show that the wood samples treated with the aminosilicone according to the invention will stain less clearly from mold fungi than untreated samples. Here, the comparative compounds S 1 and S 2, which carry no amino group, showed little or no improvement over the untreated control K. The aminosilicones according to the invention having primary amine groups (AS 1, AS 3, AS 5) show a significantly lower infestation than the untreated wood sample K or the comparative compounds S 1 and S 2.

The wood samples which were treated with amino silicones according to the invention with quaternary amino group (AS 6, AS 2) showed no mold attack even after the entire treatment period of 7 weeks. Therefore, protective agents according to the invention show comparable efficacy as a conventional fungicidal protective agent (B).

Moreover, the results show that the effect of silicones on mold is not due solely to the hydrophobization of the lignocellulosic material, but that the amino silicones according to the invention have an increased activity against mold because of their amino groups.

EXAMPLE 5 Impregnation with Amino Silicones to Improve Weathering Resistance and to Protect against Wood-Diminishing Fungi (Blue) To demonstrate an improvement in the weathering resistance of lignocellulosic materials by the aminosilicones according to the invention, impregnated pinewood samples of dimensions 15 × 75 × 150 mm (radial, tangential , longitudinal) from the end of September 2003 to the beginning of April 2004 (about 24 weeks) at a weathering stand in Göttingen (Germany) exposed to outdoor weathering. The surfaces of the wood samples were oriented to the south, taking an angle of 120 ° to the earth's surface. Following the weathering time, the cracking, the infestation by surface fungi on the south-facing side and the infestation by mold on the north-facing side were visually on a scale of 0 (no infestation or no cracking), 1 (low infestation) , 2 (moderate infestation) and 3 (severe infestation, severe cracking) classified.

The wood samples were impregnated according to Example 1 with the aminosilicones AS 1 and AS 6 according to the invention with a proportion of 5 wt .-% in the impregnating solution according to Example 1.

The results are shown in FIG. 6 and it can clearly be seen that wood samples treated with the aminosilicone wood according to the invention have a significantly lower cracking and a lower level of attack by surface fungi (blues, molds) than the control samples (comparative silicone S 3 or untreated wood K) , This discoloration is caused by the blue pi & azobasidium pulp, which feeds mainly on degradation products of the wood, which are released by UV irradiation and subsequent leaching by water.

Therefore, it can be concluded from these results that the degradation caused by the weathering is significantly reduced by the aminosilicones of the present invention. This was further evident from the fact that the untreated wood samples lost their brown color to a greater extent than the samples impregnated with the protective agent according to the invention. Example 6 Reduction of Water Absorption and Increasing Dimensional Stability Wood samples having the dimensions 25 × 25 × 10 mm (radial, tangential, longitudinal) were vacuum-bonded according to Example 1 with amino silicone compounds AS 5 according to the invention in a concentration of 5% by weight. or AS 6 in concentrations of 30 wt .-%, 15 wt .-% and 7.5 wt .-% of the aminosilicone in water, the comparative silicone S3 without amino function or water as control K treated. After drying, the pine wood samples were measured in the radial, tangential and longitudinal directions and then conditioned in a climate chamber at 20 ⁰ C and 65% ambient humidity to constant weight. Subsequently, the Längen¬ dimensions were determined again. Subsequently, the samples were immersed in water and a vacuum of about 50 mbar was applied so that a water-saturated state of the samples could be established. Subsequently, again the dimensions of the wood samples were determined.

The values for weight gain (GZ, percent) given in FIGS. 7 (pine wood) and 8 (beech wood) represent the change in weight of the wood samples due to incorporation of the protective agent according to the invention. The water used for the control led to a slight reduction in weight. Here it becomes clear that the different amino silicones were absorbed in different masses by the wood.

From the determined length measurements before and after immersion, the relative swelling / shrinkage was calculated as:

S ( _r , t, i) = (L _k -L _d ) / L _d [%], where S ( _r , t, i) = relative swelling / shrinkage (radial, tangential, longitudinal),

Lk = length of air-conditioned samples (radial, tangential, longitudinal),

Ld = length of conditioned samples (radial, tangential, longitudinal)

The relative volume swelling or shrinkage of the can be calculated according to:

Sv = (Sr + I) - (St + I) - I [%], where Sv = volume swelling / shrinkage

Sr = radial swelling / shrinkage, St = tangential swelling / shrinkage.

From this it is possible to calculate the anti-shrinkage / anti-swelling effect (ASQW), which represents a measure of the increase in dimensional stability as a result of the treatment with the protective agent according to the invention compared to a control or comparison compound:

ASQW (T _A i) = (Su - Sb) / Su [%], where ASQW (^ ₁₎ = anti-shrinkage / anti-swelling action (radial, tangential, longitudinal),

Su = swelling / shrinkage of the untreated sample,

Sb = swelling / shrinkage of the treated sample

The anti-shrinkage / anti-swelling effect was determined for two ranges of wood moisture content, namely ASQW 0-20 / 65 between absolutely dry wood (0% wood moisture) and the moisture content of wood in normal climate (temperature 20 ⁰ C, 65% relative humidity) (corresponds to about 12% wood moisture), and ASQW 0-100 between absolutely dry wood (0% wood moisture) and water-saturated wood (100% wood moisture).

The results presented in Figures 7 and 8 illustrate that the wood samples treated with the present invention have significantly increased ASQW over the control sample treated with water, i. a significant increase in the dimensional stability when the wood moisture changes.

The effect of the protective agents according to the invention on increasing the dimensional stability of wood can be demonstrated both for hardwoods (shown here for beech) and for softwoods (shown here for pine). The increase in dimensional stability is achieved in particular by microemulsions of the protective agents according to the invention, while the increase in the dimensional stability by macroemulsions of the same protective agents is lower.

Example 7: Durability of Inventive Protection Agents on or in Wood. To determine the durability of the application of wood preservatives according to the invention, the leaching of the preservatives from impregnated wood samples was measured. For this test, according to Example 1 impregnated samples of pine wood with the Dimensions 5 x 10 x 30 mm (radial, tangential, longitudinal) following impregnation in a Soxhlet apparatus for 8 hours under reflux with water. The wood samples were continuously washed by returning water of about 90 ⁰ C. In this way it was ensured that no equilibrium between wood sample and extractant could be established, but in each case unladen extractant washed around the wood samples and a maximum extraction was carried out.

A weighing of the extract obtained after removal of the extractant water showed that about 2 to 5% of the erfiαdungsgemäßen amino silicones were washed out. This even under extreme conditions (90 ⁰ C, 8 h) only slight leaching of the protective agents of the invention shows their good fixation on or in the impregnated wood.

EXAMPLE 8 Flame Retardation or Reduction of Flammability by Aminosilicones To demonstrate the reduction in flammability, pine wood samples of the dimensions 5 × 10 × 30 mm (radial, tangential, longitudinal) with aminosilicone AS 3 (5% by weight in impregnating solution) according to the invention and Comparison with a commercial flame retardant for wood (Impralit F 3/66, Rütgers Organics) according to Example 1 impregnated. Untreated wood was used as control K. Subsequently, the wood samples were ground. The wood flour was continuously heated under oxygen at a rate of 20 ° C / minute from 0 ⁰ C to 800 ⁰ C on a thermobalance (STA 409 PC, Netzsch), the weight changes were measured.

The results are shown in FIG. 9 and show that the pine wood sample treated with the aminosilicone according to the invention loses mass only at a significantly higher temperature than the control sample or the sample treated with the conventional flame retardant. This suggests a significant reduction in the burning rate in the case of fire by means of the protective agent according to the invention.

In a further test for reducing the flammability or for flame retardancy by the protective agents according to the invention, pinewood samples impregnated with aminosilicones AS 1, AS 3, AS 4, AS 5 and AS 6 and having dimensions of 5 × 10 × 100 mm are impregnated according to the method of Example 1 (radial, tangential, longitudinal) at 20 ⁰ C and 65% relative humidity air-conditioned. One treated and one untreated wood sample were arranged in a V-shape at an angle of about 45 ° to the horizontal and were at the bottom End 5 mm. Both wood samples were simultaneously ignited with a Bunsen burner for 25 seconds. By the time the untreated sample was about 2/3 burnt, the flames were extinguished. The burn-up distance and the weight loss of the treated wood samples were compared with the values of the untreated wood samples. The weight loss is shown in FIG. 10, the burn-up path in FIG. 11.

From Figures 10 and 11 it is clear that the treatment with preservatives of the invention compared to untreated wood leads to a significant reduction in weight loss and the burning distance in the same time.

Example 9: Fixation of boric acid by aminosilicones

Samples of Kiefemsplintholz with the dimensions 5 x 10 x 30 mm (radial, tangential, longitudinal) are stored until reaching the equilibrium moisture in a climatic chamber at 20 ⁰ C and 65% relative humidity. The samples are treated with a solution of (a) 3% by weight boric acid, 5% by weight aminosilicone AS 1, 92% water, (b) 3% by weight boric acid, 5% by weight aminosilicone AS 5, 92 % Water or (c) 3 wt .-% boric acid, 97% water in a vacuum process according to Example 1 impregnated.

After removal from the impregnating liquid, the samples are dried for 4 hours at 60 ⁰ C and a further 16 hours at 120 ⁰ C and then stored for 24 hours in the climatic chamber at 20 ⁰ C and 65% relative humidity. Each of five samples was completely covered with 37.5 mL of demineralized water and soaked with the aid of a negative pressure of 100 mbar and remained submerged in demineralized water for a further 4 days. The fixation of the boron compound was determined on the basis of the boron emerging from the samples. Analysis of water samples after 4 days revealed a boron concentration of 2.38 g / L for (c) boron-treated wood alone and 1.22 g / L for (b) and 1.68 g / L, respectively the samples treated according to (a) with aminosilicones according to the invention.

The selected test conditions for the leaching of boric acid from the wood samples show that the aminosilicones significantly reduce the leaching of boric acid. Therefore, the aminosilones of the present invention are capable of fixing the boron compounds conventionally used as the biocidal wood preservatives, such as boric acid and other boron salts, in the lignocellulosic material, thus maintaining the effect of the boron compound for a long period of time. Example 10: Increasing resistance to soft rot by aminosilicones Pine sapwood samples of the dimensions 5 × 10 × 100 mm (radial, tangential, longitudinal) are treated according to Example 1 with the aminosilicones AS 1, AS 2 or AS 4 and according to the European prestandard ENv 807 over 16 weeks in contact with the ground exposed to the infestation by soft rot fungi. In contact with the ground, the wood is exposed to a variety of microorganisms that break down unprotected wood very quickly and lead to a loss of strength.

The controls are untreated non-durable pine sapwood samples and moderately durable pine heartwood samples. The degree of degradation of the wood samples was determined by the loss of the dynamic modulus of elasticity (dyn. E modulus). Results are shown in FIG.

The lower decrease of dyn. Young's modulus in the aminosilicone-treated wood samples compared to the untreated ones is evident both after 8 and 16 weeks of contact with the soil. This shows that the treatment with protective agents according to the invention drastically slows down the degradation by soft rot fungi, the resistance of the pine sapwood treated according to the invention even being significantly higher than that of the untreated, moderately durable pine heartwood.

The examples make it clear that the use according to the invention of amino-modified silicone as a preservative for wood gives this and other lignocellulosic materials a markedly reduced water-absorption capacity. This reduced water absorption suggests that the preservatives to be used according to the invention make wood and other lignocellulosic materials more resistant to changes in the moisture content of the environment, for example to weathering.

It has also been proved that wood which has been treated with Schutamitteln to be used according to the invention is subject to a significantly lower infestation by superficial mildew and blue fungus. This is a consequence of the combined effect of hydrophobing and imparting antiperspirant properties by the aminosilicones of the invention. The invention offers the further advantage that the aminosilicones to be used as protective agents are less toxic than known fungicidal compounds of wood preservatives. This is partly due to the fact that the protective agents according to the invention can hardly be absorbed and metabolized by humans or animals because of their high molecular weight and their rather chemical inert character.

As a further advantage, the protective agents to be used according to the invention provide lignocellulosic materials, for example wood, increased resistance to attack by algae and harmful marine organisms, such as, for example, shells. As a further advantage, the use of wood according to the invention offers increased resistance to attack by algae.

Furthermore, the preservatives to be used according to the invention can increase the resistance of wood to wood-destroying insects, for example termites, domestic goat beetles, common ruffians, sapwood beetles. This is the case in particular if, in addition to the protective agents according to the invention, insecticides are introduced into the lignocellulosic material.

Furthermore, the degradation experiments, i. the measured mass loss of beech and pine in contact with the white rot fungus Trametes versicolor or the brown rot fungus Coniophora puteana, that the inventive use of amino silicones as a protective agent wood and other lignocellulosic materials against wood-destroying fungi resistant.

The use according to the invention of amino-modified silicones also leads to lignocellulosic materials, for example wood, being markedly more resistant to attack by surface fungi, such as mold or blueness. Here again, it is shown that the protective agents to be used according to the invention can impart both hydrophobic and also antiperspirant properties to the treated lignocellulosic material.

Tests on the swelling and shrinkage behavior of beech and spruce wood samples show that the protective agents to be used according to the invention give wood increased dimensional stability in the event of moisture fluctuations in the environment. this leads to a significantly reduced cracking, as could be shown in weathering experiments.

The outdoor weathering tests showed that wood samples treated with the preservative to be used according to the invention have increased color stability. This protection is due to the fact that, in particular, lignin degradation in the upper cell wall layers of the wood is less rapid than in untreated wood. Reduced leaching of lignin, possibly degraded by UV irradiation, could play a role here.

The leaching tests with boric acid for determining the fixation of hydrophilic substances by the protective agents according to the invention in lignocellulosic materials show that the use according to the invention of the aminosilicones achieves fixation or retention of hydrophilic substances in wood or lignocellulosic materials. The fixation or retention of lipophilic substances in lignocellulosic materials by the use according to the invention as protective agents go back to the general lipophilic properties of these silicone derivatives. Therefore, the protective agents to be used according to the invention are suitable for fixing conventional wood treatment agents, such as, for example, flame retardants, fungicides, insecticides or dyes. This applies above all to those conventional compounds which are poorly retained in the matrix of the lignocellulosic material and easily washed out by water.

The thermogravimetric analysis shows that the use according to the invention as protective agents leads to an increased flame resistance or fire resistance of the lignocellulosic materials treated therewith, as demonstrated by the example of wood. This is particularly the case if, in addition to the preservatives according to the invention, conventional flame retardants are applied to the lignocellulosic material, for example those from phosphorus compounds (phosphates, polyphosphates), magnesium compounds (magnesium hydroxide), aluminum compounds (aluminum hydroxide), bromine / chlorine compounds (hydrogen halides) and flame retardant systems with inflating substances. The protective agents to be used according to the invention can also serve for the physical and / or chemical bonding of conventional treatment agents for wood or other materials based on cellulose and thus increase their stability. This relates in particular to the combination of protective agents according to the invention with flame retardants, insecticides or dyes, especially those compounds which are preferably stable in a hydrophobic environment or are retained there.

Moreover, woods treated with protectors used in accordance with the present invention may have more resilient surfaces, i. For example, harder and / or more abrasion resistant surfaces.

Claims

Claims:

1. Use of amino-modified silicone as antimicrobial protective agent for lignocellulosic materials.

2. Use according to claim 1, characterized in that the antimicrobial protection agent against fungi is inhibitory or biocidal.

3. Use according to claim 1 or 2, characterized in that the amino-modified silicone has the general formula I: RS -A _n -B _1n -RO (I), having the structural units

is that are arranged arbitrarily,

wherein the substituents R 1 to R 4 are each independently selected for each structural unit from the group consisting of saturated and unsaturated, straight-chain, branched and cyclic hydrocarbon radicals having 1 to 20 carbon atoms, at least one radical having an amine substituent which is a primary, secondary, tertiary or quaternary amine; n is 0 to 50, preferably 1 to 10; m is 0 to 50, preferably 1 to 10;

R5 and R6 are selected from the group consisting of saturated and unsaturated, straight-chain, branched and cyclic alkyl or alkoxy groups having 1 to 20 carbon atoms.

4. Use according to claim 3, characterized in that R5 and R6 are independently selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, methoxy, ethoxy, propoxy, isopropoxy, butoxy and / or isobutoxy.

5. Use according to any one of claims 3 to 4, characterized in that the Sύbstituenten Rl to R4 are independently selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, iso-butyl and lauryl.

6. Use according to one of claims 3 to 5, characterized in that the structural units A and B are arranged linearly.

7. Use according to one of claims 3 to 6, characterized in that the structural units are arranged as R5-A _n -B _m -A-R 6, where n = 1 to 15, preferably 1 to 10, m = 1 to 5 R4 is - (CH ₂ ) ₃ -NH ₂ or - (CH ₂ ) ₃ -NH- (CH ₂ ) ₂ -ISfH ₂ and R 5 and R 6 are methyl.

8. Use according to any one of claims 3 to 7, characterized in that the structural units are arranged as R5- A _n -B _1n - An-B _m -A _n -R 6, the at least one amine substituent -XN ⁺ (Rl) ₂ (RZ), where X is a (CH ₂ ) chain of 1 to 10 methylene units and n = 0 to 15, m = 1 to 2.

9. Use according to one of claims 3 to 8, characterized in that R2 is a long-chain alkyl or fatty acid chain having 8 to 20 carbon atoms, preferably lauryl and n = 2 to 10.

10. Use according to one of the preceding claims, characterized in that a mixture of different amino-modified silicones is used.

11. Use according to one of the preceding claims, characterized in that the amine-modified silicone is the product of a crosslinking of amino-modified silicones according to formula I.

12. Use according to one of the preceding claims, characterized in that the amino-modified silicone directly bonded to silicon condensable groups and that it has a content of at least one polysiloxane containing at least three Si-bonded hydrogen atoms per molecule.

13. Use according to one of the preceding claims, characterized in that the amino-modified silicone directly bonded to silicon condensable groups and that it has a content of at least one trialkoxy and / or tetraalkoxysilane.

14. Use according to claim 12 or 13, characterized in that the protective agent has a content of catalyst for accelerating the condensation.

15. Use according to one of the preceding claims, characterized in that the protective agent has a content of at least one boron compound.

16. Use according to one of the preceding claims, characterized in that the protective agent has a content of at least one copper compound.

17. Use according to one of the preceding claims, characterized in that it has a content of an insecticide and / or fungicide and / or flame retardant.

18. Use according to one of the preceding claims, characterized in that the protective agent is in aqueous emulsion or solution.

19. Use according to one of the preceding claims, characterized in that the protective agent comprises a solubilizer and / or emulsifier.

20. Use according to claim 19, characterized in that the solubilizer or emulsifier is an amino-modified silicone according to formula I, a quaternary fatty amine alcoholate, quaternary fatty amine ethoxide, a polyalcohol, propylene glycol, ethylene glycol or butyl diglycol.

21. A method for preserving lignocellulosic materials, characterized by the use of a protective agent according to any one of claims 1 to 20.

22. The method according to claim 21, characterized by the application of the protective agent by brushing, spraying, dipping, vacuum impregnation, pressure impregnation or Kesseldruckiinprägnieren (vacuum pressure impregnation).

23. The method according to claim 21 or 22, characterized by subsequent annealing at a temperature of 50 to 150 ⁰ C, preferably at 80 to 100 ⁰ C.

24. Protective agent for lignocellulosic materials for use according to one of the preceding claims, characterized by a content of at least one amino-modified silicone, which has the general formula I: R 5 -A _n -B _m -R 6 (I),

with the structural units

A = and B =, which are arranged arbitrarily,

wherein the substituents R 1 to R 4 are each independently selected from the group consisting of

A group consisting of saturated and unsaturated, straight-chain, branched and cyclic hydrocarbon radicals having 1 to 20 carbon atoms, wherein at least one radical having an amine substituent, which is a quaternary amine; n is 0 to 50, preferably 1 to 10; m is 0 to 50, preferably 1 to 10;

R5 and R6 are selected from the group consisting of saturated and unsaturated, straight-chain, branched and cyclic alkyl or alkoxy groups of 1 to 20

Carbon atoms.