FR2661358A1 - WOOD IMPREGNATING AGENT COMPRISING A FINISHING PRODUCT AND PROCESS FOR PRODUCING THE SAME. - Google Patents

Abstract

The invention relates to a liquid impregnating agent for wood, comprising a finishing product, containing a solvent and a biocide. The problem to be solved is to create a water-free impregnating agent, which can be applied by painting, penetrates well into the wood and gives a finished smooth and shiny surface. The impregnating agent is characterized in that it contains as the main component of the drying substance isocyanate-modified linseed oil and, in addition, a drying mixture, in that the solvent consists predominantly of hydrocarbon-free aliphatic liquids and in that it further contains a dispersion of fine particles of paraffin, wax or polyolefin. The process consists of adding to the solvent, with stirring and in order, the isocyanate-modified linseed oil, the drying mixture, the biocide, the anti-skin formation agent and the dispersion of fine particles. paraffin, wax or polyolefin, the mixture being each time stirred until homogeneous before adding the next component. The invention can be applied to the protection of wood.

Description

Impregnating agent for wood comprising a finishing product and

process for the manufacture of

this agent.

  The present invention relates to a liquid impregnating agent for wood, comprising a finishing product. It further relates to a process

for the manufacture of this agent.

  The impregnating agents for wood are already known. They serve to protect the wood against harmful actions from the environment as well as to prolong its service life. In particular, efforts are made to provide protection against attack by fungi and putrefactive bacteria, algae and animals such as insects Typically, impregnating agents are systems

  liquids, which may also contain water.

  An ideal wood protection agent must have a long-lasting toxic action against parasites while not being toxic to humans and domestic animals. It must not attack metals; it must also penetrate as easily as possible, even into untreated wood. It must not be washed away by rain and the like and must be as economical as possible. An important difficulty arises in getting the agent into the wood. Consequently, pressure vessel methods are currently used, in which the pre-dried wood is subjected alternately to overpressures and to depressions in a closed container containing the 'impregnating agent. These methods are not applicable, or are only very expensive, to finished wooden objects and in particular to civil engineering wooden articles. The processes by painting, which are also already known, have the disadvantage that wooden objects must first receive a printing layer with an impregnating agent, be dried for a long time, then be provided with another surface layer To this is added the fact that the carbolineum, previously used as a 'effective impregnation, can no longer be used today because of its toxicity. The problems set out above and the drawbacks of current solutions in the wood preservation sector are dealt with in detail in Rômpp's "Chemie-Lexikon" (chemistry lexicon), for example in the sixth edition of 1966,

volume II, p 2758 to 2762.

  The problem of the present invention has been to create a water-impregnating agent for wood, acting in particular as a fungicide and algaecide, which can be applied by painting, penetrating better into the wood than the known agents, but acting at the same time to give a surface finish, that is to say making superfluous the application of a varnish, a lacquer or a surface layer In addition, this agent must better protect the wood against the action of water, ultraviolet rays, solar radiation and cold It must also be compatible with the environment, including during its manufacture Finally, we ask that the surface of the wood be smooth and shiny and have a finish that can only be obtained by special coatings and that the impregnation and

finished are durable.

  To this end, the invention relates to an impregnating agent of the above type, characterized in that it contains, as main component of the drying substance, linseed oil modified with isocyanate and, in addition, , a drying mixture, in that the solvent consists mainly of aliphatic liquids free of hydrocarbons and in that it also contains a dispersion of fine particles of

  paraffin, wax or polyolefin.

  Particular embodiments are

described below.

  As has also been surprisingly found, the order of addition of the components of the wood impregnating agent according to the invention during manufacture is decisive in obtaining the best results for a given order. Consequently, the invention also relates to a process for manufacturing the impregnating agent for wood, this process being characterized in that by stirring the solvent deposited beforehand, one is added one after the other and in the order the following components: 20 to 35 parts of isocyanate-modified linseed oil, 0.05 to 0.12 part by weight of siccative mixture in relation to the metal, 0.1 to 1.0 part of biocide , O to 0.8 part of a component against skin formation, O to 1 part of Theological additive, 8 to 12 parts of a dispersion of 25% polyethylene in

white spirit.

  We will now identify more precisely the individual constituents of the agent

  impregnation according to the invention.

  The main component ("body") of the solvent-free phase of the agent, is a drying oil based on linseed oil, which is normally known only for surface layers. preferably a linseed oil modified with isocyanate A product which is particularly suitable is "Desmalkyd L 181" supplied by the company

Bayer in Leverkusen, FRG.

  To ensure better hardening of this product, which dries well in air but whose hardening must take place by itself inside the wood where the air cannot arrive, add the drying metal salts known in following ones:

  naphthenate, octoate, linoleate, resinate and the like.

  A product which has been found to be particularly suitable is a mixture of cobalt, calcium and zirconium compounds, this mixture being new and causing surprisingly good and rapid drying. Very suitable driers of this group, ie say the different metal derivatives, can be obtained under the trade designation "Nuodex" from the

  Company URAI S p a, Assago, Italy.

  As solvents, the wood impregnating agent according to the invention only comprises aliphatic compounds containing oxygen. The solvents chosen seem to be responsible for the good penetration into the wood of the agent according to the invention. in addition, they are much more compatible with the environment than hydrocarbons and do not interfere with the chemical drying of the linseed oil derivative An alcoholic ester whose boiling point is between 180 and 260 ° C has proven its worth such alcoholic esters are, for example, monoformate and glycol acetate The product "Texanol" from Eastman

Chemical Company is preferable.

  As a biocidal substance, the wood impregnating agent according to the invention preferably contains a sulphonamide derivative active against fungi, algae, of the penicillium type, resistant to light, nonvolatil, and not interfering with the drying of the linseed oil derivative An N, N-diaryl N'-aryl N '- (trihalogenomethylthio) is preferably used

sulfonamide.

  The wood impregnating agent according to the invention generally, but not necessarily, contains a leveling product, for example aldoximes or ketoximes which makes it possible to prevent skin formation. Suitable oximes are, for example, butyraldoxime, methyl ethyl ketoxime and cyclohexanoneoxime Other suitable additives are rheological additives such as, for example, layered and modified organic silicates ("Bentone SD-1" from Kronos Titan Gmb H, Leverkusen, RFA) as well as other usual additives such as wetting agents and dispersing agents, flavors, etc. The wood impregnating agent according to the invention contains, as a component giving the glossy finish, a finely dispersed polyolefin and / or a wax emulsion or paraffin In particular, the product "Lanco-Glidd KH" is used, a dispersion of finely dispersed polyethylene with a maximum particle size of 3000 nm and a size m 500 nm particle average, about 25% in white spirit, supplied by G M Langer & Co, Bremen,

FRG.

  The composition of particularly suitable impregnating agents for wood is as follows, indicated by parts by weight: Linseed oil modified with isocyanate: 20 to 35 Drying mixture (in each case based on the metal): 0.05 to 0, 15 Biocide: 0.1 to 1.0 Paraffin and wax / polyethylene emulsion at 25 t: 8 to 15 Theological additive: O to 1.0 Agent against skin formation: 0.2 to 0.8 Solvent, alcoholic esters: complement to 100 For practicing the following process

  the invention, the solvent is first placed in a container.

  with stirring, the modified linseed oil is allowed to dissolve and the siccatives and the biocide are added. Among the additives chosen, the agent against skin formation is added immediately after the siccatives, the additive rheological after the biocide After that, the wax emulsion is used. During training, it is, of course, constantly stirred. The best work is done at normal room temperature; a load of approximately 100 kg is completed in approximately 20 to 30 minutes After the addition of each component,

  the mixture is stirred until homogeneity is obtained.

  The impregnating agent is further distinguished by an increased shelf life, generally from 8 to

12 months approximately.

  For the application, the surface of the mechanically cleaned wood is coated or sprinkled with the liquid agent, it is left to dry, for example for 24 hours and the surface is coated with a second layer of the same agent A third layer n is necessary only very rarely The wood is then impregnated for its conservation and also presents its natural color, for example walnut, larch, mahogany, teak etc, without another additional layer such as stain etc being necessary The surface is shiny and

  gives the feel of wax.

  The impregnation with the finishing product is

particularly durable.

  An example will serve to explain more

clearly the invention.

EXAMPLE

  56.2 kg of "Texanol" (alcoholic ester, boiling point 2440 C) are added to an agitating container provided with an air vent and having a useful capacity of approximately liters. gradually the following products: 25 kg of "Desmalkyd L 181", 0.3 kg of cobalt drier (6% Co), 1 kg of calcium drier (4% Ca), 0.5 kg of zirconium drier (12 % Zr), 0.5 kg of "Exkin 2" (methyl ethyl ketoxime), 0.5 kg of biocide, 4 kg of "Bentone SD 1" (8% paste) and 12 kg of "I Lanco Glidd" (25 % in white spirit) After minutes of stirring, a transparent impregnating agent having the properties is obtained

  described above and penetrating very well into the wood.

  As already mentioned, an additional surface treatment of the impregnated wood is not necessary since this wood is already finished so

  fully desirable and appropriate.

Claims (6)

  1) Impregnating agent for wood in liquid form, comprising a finishing product, containing a solvent and a biocide, characterized in that it contains, as main component of the drying substance, linseed oil modified with isocyanate and, in addition, a drying mixture, in that the solvent consists mainly of aliphatic liquids free of hydrocarbons and in that it also contains a dispersion of fine particles of   paraffin, wax or polyolefin.   2) impregnating agent according to claim 1, characterized in that the drying mixture is a mixture based on cobalt compounds, calcium and zirconium.   3) Impregnating agent according to one   any of claims 1 and 2, characterized in   that it also contains an agent based on oximes against skin formation.   4) Impregnating agent according to one   any one of claims 1 to 3, characterized in that   that it also contains a Theological additive based silicates. ) Impregnating agent according to one   any one of claims 1 to 4, characterized in that   that it contains as an biocide an N, N-diaryl   N'-aryl N '- (trihalogenomethylthio) sulfonamide.   6) Impregnating agent according to claim 4, characterized in that its composition by parts by weight is as follows: a)> 20 to 35 parts of linseed oil modified with isocyanate, b) 0.05 to 0 , 15 part of siccative mixture, with reference to the metal, c) 0.2 to 0.8 part of agent against skin formation, d) 0.1 to 1.0 part of biocide, e) O to 1 part of rheological additive, f) 8 to 15 parts of 25% polyethylene dispersion in white spirit, and   g) the complement to 100 parts in solvent.   7) Impregnating agent according to one   any one of claims 1 to 6, characterized in that   that the solvent consists essentially of alcoholic esters. 8) Process for the manufacture of the impregnating agent according to claim 6, characterized in that by stirring the component g) deposited beforehand, one is added one after the other and in the order indicated in the claim 6 components a) to f) and the mixture is stirred until homogeneous, each time,   before adding the next component.