Protective agents for wood

Details Protective agents for wood Protective agents for wood

2000-10-04

2002-10-15

Green, Anthony J. (Department: 1755)

Compositions: coating or plastic

Coating or plastic compositions

Contains fireproofing or biocidal agent

C106S015050, C106S018000, C514S642000, C514S663000, C514S673000, C514S674000, C514S740000, C427S421100, C427S428010, C427S439000, C427S440000, C427S441000, C427S442000

Reexamination Certificate

active

06464764

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to coating materials and treatment compositions for protecting wood and/or cellulosic substrates against biological material destruction, to a process for preparing the coating materials and treatment compositions, and to a method of using them.
2. Background Art
To reduce the environmental impact of organic solvents in coating materials, it is state of the art to use binders which are dispersible or emulsifiable in water. Especially for coating materials which are used on wood or wood materials, modified drying oils (e.g. linseed oil, soya oil, etc.) or correspondingly modified alkyd resins are available. The emulsifiability of such oils or alkyd resins is achieved by adding emulsifiers or, in a more elegant way, by incorporating hydrophilic groups into the binder molecule by means, for example, of transesterification with dicarboxylic or polycarboxylic acids and/or reaction with polyalcohols, polyethylene glycols, ethylene oxide, etc. The incorporation of hydrophilic groups leaves the film-forming properties of the oils and alkyd resins substantially unaffected.
The oils and alkyd resins with hydrophilic groups in the molecule have the advantage over the systems with added emulsifier that following oxidative drying the emulsifier cannot be washed out and hence neither the removal of active substances (e.g. substances acting against fungi and/or insects) nor the weather resistance are adversely affected by the free emulsifier.
Irrespective of whether a separate emulsifier is added to the systems or hydrophilic groups are incorporated into the oil or alkyd resin molecules, a general problem which arises with the known water-based treatment compositions and coating materials is that the ready-to-use emulsions have a limited life. Prolonged standing of the preparations is accompanied by instances of phase separation, creaming, or sedimentation of the heavier constituents, with reemulsification not always being an option.
A further disadvantage of the known emulsions and dispersions, especially those comprising biocidal active substances, is their poor penetration capacity into wood and wood materials. The active substances and additives tend to be situated in the dispersed organic phase, which accumulates near the surface, while only the dispersion medium, i.e. the water, penetrates into deeper layers. Homogeneous distribution of active substances, for example substances acting against rot, blue stain or insects, is virtually impossible to achieve with these systems and they biocidal activity is lost as soon as the surface is removed or damaged.
BROAD DESCRIPTION OF THE INVENTION
It was therefore an object of the present invention to provide storage-stable water-based treatment compositions and coating materials whose biocidal active substances penetrate effectively into wood or similar materials.
In accordance with the invention, this object is achieved by means of the coating materials, treatment compositions, method and process of the invention.
It has surprisingly been found that the abovementioned disadvantages of the known coating materials and treatment compositions may be eliminated by adding biocidal primary, secondary or tertiary amines or their salts or quaternary ammonium salts or mixtures of the aforementioned amines and/or salts to the aqueous emulsions of natural or synthetic oils, alkyd resins based on natural or synthetic oils, or mixtures of the aforementioned binders. The amines and ammonium salts that may be used in accordance with the invention possess at least one alkyl group having 6 to 24 carbon atoms, preferably having 8 to 18 carbon atoms. In the present case, primary amines include those which in addition to one or more primary amino groups also contain one or more secondary and/or tertiary amino groups in the molecule. The coating materials and treatment compositions of the invention contain from 2 to 50%, preferably from 5 to 25%, of binder(s) and from 0.5 to 40%, preferably from 1 to 10%, of amines and/or ammonium salts. Hereinbelow, all percentages, unless otherwise defined, are by mass and relate to the total composition. The term “alkyl group” embraces both linear and branched groups having the particular number of carbon atoms stated.
DETAILED DESCRIPTION OF THE INVENTION
For example, an emulsion containing 15 parts of binder (oil or alkyd resin with hydrophilic groups in the molecule) and 85 parts of water becomes clear following the addition of 5 parts of DDAC (didecyldimethylammonium chloride) and after brief stirring; any turbidity disappears, and a completely transparent solution is formed. Even years of storage, fluctuating temperatures, and freezing and thawing of the system are not accompanied by any phase separation or separation of components.
Examples of suitable amines for the coating materials and treatment compositions of the invention are the following:
as primary amines: C
8-18
-alkylamines, N-(C
8-18
-alkyl)ethylenediamines, N-(C
8-18
-alkyl)propylenediamines, N,N-bis(2-aminoethyl)-C
8-18
-alkylamines, or N,N-bis(3-aminopropyl)-C
8-18
-alkylamines; as secondary amines: methyl- or ethyl-C
8-18
-alkylamines; and as tertiary amines: dimethyl(C
8-18
-alkyl)amines. Examples of suitable salts of the amines are the halides, especially the chlorides and bromides, and the salts with organic acids. Organic acids hereinbelow are especially linear or branched C
1-6
carboxylic acids such as, for example, formic acid, acetic acid, propionic acid, butyric acid or isobutyric acid, and also hydroxy acids such as, for example, glycolic acid, lactic acid, malic acid or tartaric acid, or else sulphonic acids such as, for example, methanesulphonic acid, benzene-sulphonic acid or toluenesulphonic acid.
The systems of the invention penetrate rapidly and deeply into wood and wood materials; no partial concentration differences can be found in the wood. The uniform penetration of all ingredients of the systems of the invention, comprising binder, cationic compounds and water, is surprising, since it is known that cationic compounds such as ammonium salts alone show little or no penetration into wood or comparable substrates, with the result that the biocidal activity of quaternary ammonium compounds applied from aqueous solutions, this activity being known per se, is normally restricted to the near-surface regions of the substrates. The present invention, therefore makes it possible to prepare preparations which are solvent-free, possess long-term stability (storage life), are transparent, and display penetration into wood and wood materials comparable with that of solventborne systems, combined with uniform distribution of all ingredients and good coating activity and processability.
Preferably, the coating materials and treatment compositions of the invention comprise a quaternary ammonium salt as biocidal component.
Examples of suitable quaternary ammonium salts are the following:
dimethyldi(C
8-18
alkyl)ammonium halides, dimethyldi(C
8-18
alkyl)ammonium salts of organic acids, trimethyl(C
8-18
alkyl)ammonium halides, trimethyl(C
8-18
alkyl)ammonium salts of organic acids, dimethyl(C
8-18
alkyl)benzylammonium halides, dimethyl(C
8-18
alkyl)benzylammonium salts of organic acids, 1,1′-dimethyl-4,4′-bipyridinium halides, and di(C
8-18
alkyl)methylpolyoxyethylammonium salts of organic acids, the terms “C
8-18
alkyl” and “organic acid” having the definitions given above.
Water-emulsifiable binders used are preferably oxidatively drying oils or alkyd resins.
In order to improve and supplement the biocidal activity, further biocides may be added to the coating materials and treatment compositions of the invention. For example, from 0.01 to 10% of the following active substances, alone or as a mixture, may be added: amphosurfactants having biocidal activity methyl benzimidazol-2-ylcarbamate
1,2-benzisothiazol-3-one
biguanides having biocidal activity
organic and inorganic boron derivatives
&agr;- tert-butyl-&agr;-(p-chlorophenethyl)-1H-1,2,4-triazole-1-e

Affiliated with

Also associated with

Rating

Protective agents for wood does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Protective agents for wood, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Protective agents for wood will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2956683