NO159001B - AFFICIENT TREATMENT FOR THREE. - Google Patents

Abstract

1. An aqueous composition for treating wood containing 1) a water-soluble or water-dispersible, oxidatively drying binder which has a double-bond content corresponding to an iodine value of at least 100 [g iodine/100 g] and is based on a 1,3-butadiene polymer optionally modified by isomerisation, partial cyclisation or partial hydrogenation, the polymer having a relative molecular weight (-Mn ) of 500 to 6000 and containing at least 70 mol % of units obtained by polymerisation of 1,3-butadiene and not more than 30 mol % of units obtained by polymerisation of one or more other copolymerisable 1,3-diolefins and alpha-monoolefins, 2) a water-insoluble organic wood preserving agent or mixture of agents and optionally also a watersoluble organic wood preserving agent or mixture of agents, and 3) optionally one or more additives conventional in the impregnating and coating industries, but excluding pore-closing additives, characterized in that 4) the binder satisfies the additional criterion that it is a polymer carrying amino groups but not quaternary ammonium groups and containing from more than 50 up to 600 mg-atom of titratable amine nitrogen per 110 g, and 5) the composition contains acid and has a pH of from 2 to 8, the acid strength and amount of acid (degree of neutralisation) on the one hand and the amount of amino groups on the other hand being selected so that the binder is water-soluble or water-dispersible.

Description

The invention relates to a treatment agent as stated in the preamble.

By wood is meant all species of wood and wood materials such as

has an open-pored structure that is available for the application methods used in the impregnation technique.

Wood preservative means wood preservatives with biocidal action, primarily insecticidal and/or fungicidal action.

The invention relates to impregnation technology for wood and related techniques. Here, an effective and lasting tree protection is sought. In this context, it is considered important to transport the binder and wood preservative in sufficient concentration deep into the parts of the wood to be protected (penetration), and fix the agents in this place. Under certain circumstances, this can also be achieved

a decorative effect in the surface of the wood.

The invention does not relate to varnishing techniques for wood.

When varnishing, the aim is exclusively to have a decorative function in the wooden surface, but not in some cases any depth effect.

With regard to the state of the art in the area of the invention, reference should be made to DE-A 30 26 300. As a wood preservative in the treatment agents (impregnation agents) for wood described there, mention is made, among other things, of mixtures of water-soluble inorganic wood preservatives and practically water-insoluble organic wood preservatives.

The water-insoluble wood preservatives can even after previous dissolution in organic solvents compatible with water, e.g. lower alcohols and ketones, only dissolve in relatively low concentrations in aqueous solutions of the binders as they are obtained in manufacture. The concentration of the non-water-soluble wood preservative in the treated wood parts that can be achieved with the treatment agents produced in this way according to the state of the art is thus relatively small. The wood protective effect that can be achieved therefore does not always correspond to the requirements in practice.

The invention is based on the task of overcoming this shortcoming and obtaining an improved treatment agent which allows the binder and the wood preservative to be transported in sufficient concentration deep into the wooden parts to be protected, and fixed there, by means of normal treatment methods.

This task is surprisingly solved with the help of

the treatment agent according to the claim.

The person skilled in the art could neither from the described state of the art nor from the more distant state of the art described in DE-A 30 04 319 and 30 1.4 194 (water-dilutable alkyd resins are mentioned here as binders)^ find hints for solving the task according to the invention. Admittedly, according to the latter document, it is possible to form treatment agents with a relatively high content of non-water-soluble

organic wood preservatives. However, satisfying

not the concentration of the wood preservative that can be achieved with the help of these treatment agents in the treated wood parts, always the requirements in practice.

Reference should be made to the comparative example (treatment agent A according to DE-A 30 14 194) which concerns the absorption of pentachlorophenol in impregnated test specimens.

The treatment agent according to the invention meets the requirements for effective and lasting wood protection. They outperform the treatment agents according to the state of the art described in DE-A 30 2 6 300, through the clearly lower water absorption of impregnated test bodies. Correspondingly, one must expect that they are better than the treatment agents according to the mentioned state of the art also with regard to the ability to regulate the moisture uptake and release of the treated wood; so that cracking in the wood as a result of tensions under ambient conditions is avoided...

The binders contained in the treatment agents are for the most part known and can be produced, according to known methods (DE-C 28 38 930, DE-A 29 11 243 and 30 26 300; see also Norwegian patent application 83 0081).

The base polymers for the production of the binder preferably have >_ 90 mole percent of structural units obtained by polymerization of 1,3-butadiene, and ^ 10 mole percent of structural units which are. obtained by polymerization of other copolymerizable 1,3-dienes and α-unsaturated alkenes. The homopolymers of 1,3-butadiene are particularly preferred.

Preferred copolymers are 1,3-dienes, such as isoprene and 1,3-pentadiene. An example of a copolymerizable, α-unsaturated alkene is styrene.

The base polymers can be prepared by known methods, as e.g. is described in DE-C 11 86 631, 12 12 302, 12 41 119, 12 51 537, 12 92 853, 20 29 416, 21 22 956 and DE-B 23 61 782.

The relative molecular mass (number average molecular weight

M ) which characterizes the base polymer, is determined vapor pressure osmometrically. It preferably amounts to 800-3,000.

In the homo- or copolymers there are preferably

< 40% of the alkenic double bonds in trans structure. Of these polymers, those where at the same time >_ 40% of the alkenic double bonds are present in cis-structure are particularly preferred.

The base polymers can be used directly as they are obtained during production, for the subsequent functionalization. However, they can also be modified in a known manner before - and possibly also after - the functionalization by isomerization, partial cyclization or partial hydrogenation. The unmodified polymers are particularly preferred.

On the way to the binders, the amino groups can be introduced into the 1,3-butadiene polymers according to various known methods.

Thus, a preferred route I leads to aminodicarboxylic acid imide addition products (DE-C 28 38 930, column 7, examples 1 and 2) via the addition of oi, g-unsaturated dicarboxylic acids or their anhydrides and possibly modification of the addition products by partial cyclization (DE-A 30 14 196). and subsequent reaction of the addition product with a primary/tertiary alkenediamine or a mixture of such diamines.

The initially obtained addition products are usually based on 16-25, preferably 18-24 mass percent maleic anhydride (MSA) and 84-75, preferably 82-76 mass percent of a polybutadiene with a relative molecular mass (M) of between 800 and 2,000, an iodine number of ^ 350

/g of iodine per 100 gJ and a cis double bond content of 70%, calculated on the total double bond content.

The primary/tertiary alkenediamines have the general formula

1 2 3 where R is a C2-C8-alkene radical and R and R independently of each other are C^-C^-alkyl radicals which may be substituted with a C^-C^- alkoxy group, the a-position of the N atom being excluded, or jointly is -(CH2)5- or -(CH2)2~0-(CH2)2~, i.e. part of a ring. 2 3 The sum of the C atoms in the radicals R and R is preferably 8.

Suitable diamines with the general formula (I) are, for example:

N,N-dimethyl-ethanediamine-(1,2),

N,N-diethyl-ethanediamine-(1,2),

N,N-dimethyl-propenediamine-(1,3),

N,N-diethyl-propenediamine-(1,3),

N,N-diethyl-tetramethylenediamine-(1,4),

2,2,N,N-tetramethyl-propenediamine-(1,3),

1-diethylamino-4-methyl-tetramethylenediamine-(1,4), N-(3-aminopropyl)-morpholine and

N-(3-aminopropyl)-piperidine. Preferred is N,N-dimethyl-propenediamine-(1,3).

Part of the diamine.can be. substituted with NH^ or a primary C^-Cg-(cyclo)alkylamine,. whose (cyclo)alkyl radical may be substituted with a C 1 -C 4 ~ alkoxy group, the a-position of the N atom being excluded.

The binder obtained in route I preferably has a content of _> 120-300 mg atoms of titratable amine nitrogen per 100 g.

A preferred route II is via 1,3-butadiene polymers containing epoxide groups• These polymers can e.g. is produced by terminal functionalization of polymers obtained by the so-called "Living Polymerization" process, with epichlorohydrin. Such polymers with epoxide groups arranged at the ends are commercially available.

They can also be produced by epoxidizing 1,3-butadiene polymers (DE-C 28 38 930, column 7, line 57, to column 8, line 5), during which vinyl groups are optionally also epoxidized.

The polymers' content of titratable epoxide oxygen

(DIN 16 945) usually constitutes. 3-9 mass percent, preferably 4-8 mass percent.

The amination of 1,3-butadiene polymers containing epoxide groups is known (DE-C 28 38 930, examples 3-7;

DE-A 29 11 243 and 30 26 300; see also Norwegian patent application

83 0081).

Suitable amines have the general formula II (diamines) and III (monoamines).

1 3

where R -R has the meaning indicated above in connection with the general formula I.

R 2 and R 3 can also independently of one another be C 1 -C 8 alkyl radicals which are substituted with a hydroxyl group, the conversion to the N atom being excluded.

R 4 is a hydrogen atom or a C 1 -C 8 alkyl radical which may be substituted with a hydroxyl or C 1 -C 4 alkoxy group, the a-position of the N atom being excluded.

Suitable diamines with it. general formula (II) is, in the case where R<4> = H (primary/tertiary alkenediamines), e.g.

the diamines indicated in connection with the general formula (I) as well as N,N-bis-(2-hydroxyethyl)-propenediamine-(1,3).

Suitable diamines of the general formula (II) are, in the case where R 4 ^ H (secondary/tertiary alkene diamines), f-ex-1-methylpiperazine and 1-(g<->hydroxyethyl)-piperazine.

R"*" is a hydrogen atom or a C 1 -C 8 alkyl radical which may be substituted with a hydroxyl group or a C 1 -C 4 ~ alkoxy group, the a-position of the N atom being excluded.

R 2 is a C 1 -C 8 -(cyclo)alkyl radical which may be substituted with a hydroxyl group or a C 1 -C 4 -alkyl group, the a-position of the N atom being excluded.

R 1 and R 2 can also jointly be -(CH 2 ) 5_ or

- (CH0)0-0- (CH„) n-, i.e. part of a ring.

A i z 12

The sum of the C atoms in the radicals R and R is preferably

< 8.

Suitable monoamines of the general formula (III) are, when R = H (primary amines), e.g. the following: methylamine, ethylamine, propylamines, butylamines, pentylamines, hexylamines, 2-amino-3-methylbutane, 2-methoxyethylamine, 3-methoxypropylamine, 3-ethoxypropylamine, cyclohexylamine, ethanolamine, 2-hydroxypropylamine, 3-hydroxypropylamine and isopropanolamine, and when R"*" ^ H

(secondary amines), e.g. the following: dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, diisobutylamine, di-s-butylamine, N-methylethylamine, N-methyl-butylamine, N-methyl-s-butylamine, N-ethyl-butylamine, bis-(2-methoxyethyl )-amine, bis-(3-methoxypropyl)-amine, N-methyl-cyclohexylamine, diethanolamine, diisopropanolamine, N-methyl-ethanolamine., 1-ethylamino-butanol-(2), piperidine and morpholine.

The secondary amines are preferred. Diethanolamine is particular

preferred.

The amount of total amines available may be equimolar with respect to the content of epoxide groups in the epoxidized polymer. It is also possible to use an excess of amine and remove the unreacted amine portion after the reaction. The amine can also be added in deficit, so that some of the epoxy rings are retained unchanged.

The binders obtained in route II preferably have a content of >_ 100-300 mg-atom titratable amine nitrogen per 100 g.

With increasing amino group content, the water solubility of the acid-neutralized binder increases and the stability of the aqueous binder solutions increases. The solubility and stability can also be improved by introducing amino groups that carry hydrophilic substituents, as quaternary ammonium groups are excluded.

The thus obtained addition products are transferred in the water-soluble resp. water-dispersible form by neutralization or partial neutralization with acids or mixtures of acids. Suitable acids are inorganic acids, e.g. sulfuric acid, hydrochloric acid and carbonic acid, and organic acids, e.g. formic acid, acetic acid, propionic acid and lactic acid.

Biocidal acids are preferably used, e.g. hydrofluoric acid, hexafluorosilicic acid, phosphoric acid, boric acid, arsenic acid, benzoic acid, salicylic acid and phosphoric acid or biocidal acid salts, e.g. potassium hydrogen fluoride, or optionally such acids which form complexes with metal ions, e.g. tartaric acid or ethylenediaminetetraacetic acid.

To achieve a sufficient solubility resp. dispersibility of the binder in water, the added amount of acid must be selected sufficiently high. The higher the concentration of amino groups in the binder, the lower the degree of neutralization can be set to achieve the desired effect. Usually, the required minimum amount of acid is 0.3-0.5 equivalents of acid per equivalent amino group. As the amount of acid increases, the stability of the aqueous binder solution increases, which makes itself felt e.g. by a better tolerance towards common additives which may be contained in the treatment agent according to the invention, and by an increased penetration ability.

Thus, under certain circumstances, it may be appropriate to use 5 equivalents of acid per equivalent amino group or more. Precisely in these cases it is. suitable at least partially to use biocidal acids.

The treatment agents preferably have a pH value of 3-7.

Suitable non-water-soluble wood preservatives are e.g. 2,5-dimethylfuran-3-carboxylic acid-N-methoxy-N-cyclohexylamide, tributyltin benzoate, tributyltin naphthenate, £-hexachlorocyclohexane, pentachlorophenol, 2-mercaptobenzthiadiazole-2, methoxy-carbonylamino-benzimidazole, N,N- dimethyl-N<1->phenyl-N'-(fluorodichloromethylthio)-sulfamide, N,N-dimethyl-N'-p-tolyl-N'-(fluorodichloromethylthio)-sulfamide, carbamates, dithiocarbamates, phosphoric acid -ters, phosphonic acid esters, thiophosphoric acid esters, dithiophosphoric acid esters, thiophosphoric acid esters, o-phenyl-phenol, hydroxyquinoline derivatives, endosulfan and pyrethroids.

Suitable water-soluble wood preservatives are, for example, alkali fluorides, fluorosilicates such as MgSiFg, alkali arsenates, borates and salts of lead, tin, cadmium, nickel, cobalt, manganese, copper, mercury, zinc and trivalent chromium, as well as (C12-C14- alkyl)-benzyl-dimethylammonium chloride.

For the production of the treatment agent according to the invention, the acidic, aqueous solution or dispersion of the binder, which possibly contains a water-soluble wood preservative, can have a non-water-soluble, organic wood preservative added which can be dissolved in a water-compatible solvent. Usually, however, it is appropriate to first add the non-water-soluble wood preservative to the binder, transfer this into salt form by further adding acid and finally prepare the finished treatment agent by adding water, possibly together with a further water-soluble wood preservative.

Suitable additives according to point 3 of the patent claim are e.g. pigments, agents to prevent the formation of a surface film, stabilizers, siccatives, surfactants, viscosity regulators and water-compatible solvents.

Suitable water-compatible solvents are e.g. isopropanol, butanols, diacetone alcohol, alkyl cellosolves and dimethyl ethers of glycols. The solvents can be used in amounts of up to 100 parts by mass calculated on 100 parts by mass of binder. Preferably work is done without solvent.

Pore-closing additives that should not occur are understood to mean such additives which, due to their nature and_ their concentration in the treatment agent, will lead to a closing of the wood's pores upon application and thereby significantly prevent the intended depth effect of the treatment agent.

Additives of the type described can be mixed in amounts that are common in practice. The type and quantity of such additives always depend on the material to be treated at any given time, its intended use and the treatment method and are easy to determine with a few indicative tests.

As the binders used in the treatment agents according to the invention have oxidative drying properties, it is not usually necessary to add additional resins as cross-linking agents. Of course, additional binders can be used at the same time which (possibly by heat treatment) act as cross-linking agents, e.g. water-soluble or dispersible aminoplasts or phenolic resins, provided that the effect sought by the invention is achieved.

The treatment agents according to the invention usually have a binder content of 1-40, preferably 5-30 percent by mass,

and can be applied by all known methods according to the state of the art (see DIN 68 800, sheet 3). In this connection, the achievable protective effect - as is known to the person skilled in the art - is closely linked to the treatment method.

Particularly effective is an impregnation method where the wood, possibly under pressure or vacuum, is subjected to a full* impregnation.

The following examples serve to illustrate the invention. Parts shall be understood as parts by mass, and by percentage shall be understood. is understood as mass percentage, unless otherwise stated.

Examples

As base polymer for the production of the binders used in the treatment agents according to the invention, a polybutadiene with the following characteristics was used: Mfi (vapor pressure osmometrically determined in chlorobenzene): approx. 1,700. Iodine number [g iodine per 100 g] (DIN 53 241): 445. Double bond distribution (IR analysis) in %, calculated on the total double bonds: 73 cis and 25 trans; (in structural units obtained by 1,4-polymerization of 1,3-butadiene); 2 vinyl (in structural units obtained by 1,2-polymerization of 1,3-butadiene).

Viscosity /Pa-s] (DIN 53 214, 20°C): 0.8.

The polymers bearing amino groups (amine adducts),

was produced in two ways.

Path I (amine adduct 1)

The amine adduct 1 was prepared in a known manner (DE-C 28 38 930, column 7, example 1) from 1,462 parts of the polybutadiene, 388 parts of MSA (= 21% MSA in the polybutadiene/MSA adduct)

and 485 parts of N,N-dimethyl-propenediamine-(1,3).

Acid number: < 3 mg KOH per g.

185 mg-atom titratable amine nitrogen per 100 g.

After adding 18 parts of 50% acetic acid to 100 parts of amine adduct 1, a mixture was obtained which could be diluted unlimitedly with water.

Path II (amine adducts 2-4)

The polybutadiene was epoxidized in a known manner with 60% H 2 O 2 in the presence of formic acid (DE-C 28 38 930 , column 7, line 60, to column 8, line 5). The obtained epoxidized polybutadiene has the following characteristics: Total oxygen content [% J (elemental analysis): 8.0. Epoxy oxygen [%] (DIN 16 945): 5.9.

Viscosity: /Pa-sj (DIN 53 214, 2Q°C) : 7.2.

4.708 parts of the epoxidized polybutadiene was mixed with 872 parts of diethanolamine under a nitrogen atmosphere and heated to 190°C with stirring. After 6 h the reaction was finished. The obtained amine adduct 2 has the following characteristics: Residual epoxide oxygen [%] : 2.5.

145 mg-atom titratable amine nitrogen per 100 g.

The amine adduct 3 was obtained in a similar manner. Residual oxydeoxygen [%] : 0.7.

232 mg-atom titratable amine nitrogen per 100 g.

The amine adduct 4 was obtained in an analogous manner, although N,N-dimethyl-propenediamine-(1,3) was used instead of diethanolamine.

Residual epoxide oxygen [%] ~: 2.6.

292 mg-atom titratable amine nitrogen per 100 g.

Preparation of the treatment agents 1-4 (according to the invention) and A (according to DE-A 30 14 194)

32 parts of amine adduct 1, 14.6 parts of pentachlorophenol (PCP) and 14.5 parts of lactic acid were mixed at approx. 70°C. After adding 314 parts of water, a light brown, slightly milk-like emulsion was obtained

. (treatment agent 1):

pH value: 2.5

Solids content (%] : 15.8.

PCP content [% J : 3.9.

31.5 parts of amine adduct 2, 14.4 parts of PCP and 6 parts of 73% lactic acid were mixed at approx. 70°C. After adding 30 7 parts of water, a light grey, slightly cloudy solution was obtained

(treatment agent 2):

pH value: 3.9.

Solids content [%] : 14.0.

PCP content [%] : 4.0.

36.1 parts amine adduct.3, 17.3 parts PCP and 7.5 parts lactic acid were mixed at approx. 70°C. After adding 374 parts of water, a light brown, clear solution was obtained (treatment agent 3):

pH value: 3.5.

Solids content [%] : 14.0.

PCP content [%] : 4.0.

32.2 parts amine adduct, 4.14.7 parts PCP and 9.0 parts 50% aqueous phosphoric acid were mixed at approx. 7Q°C. After adding 312 parts of water, a grey-brown emulsion was obtained (treatment agent 4):

pH value: 3.8.

Solids content [%] : 14.0.

PCP content [%] : 4.0.

75 parts of an alkyl resin (63% in butyl glycol), which could be diluted with water and was prepared according to DE-A 30 14 194, 4 parts of triethylamine and 26 parts of 10% aqueous caustic soda were mixed (neutralized alkyl resin). To this mixture were added 23 parts of PCP and 10 parts of an addition product of ethylene oxide and nonylphenol (molar ratio 10:1). It was then diluted with water

(treatment mite! A):

pH value: 8.3.

Solids content [%] : 15.1.

PCP content [%] : 4.0.

Impregnation test.

The impregnation tests were carried out with blocks of pine sapwood (14 x 22 x 50 mm) according to the full impregnation method (DIN 52 160, pp. 2 and 3). The results are indicated in

the table.

The determination of dry matter uptake resp. the relative dry matter absorption of the test specimens took place according to the equations:

where W = the mass of impregnated, dried wood

T = mass of untreated, dried wood

I = mass of impregnated wood without drying.

For calculation of the PCP dry substance absorption, in the test bodies, W was determined indirectly by determining the quantity of the remaining PCP in the treatment agent after the impregnation.

As will be seen from. the table, the relative dry matter uptake agrees well with the solids content of the treatment agent. On the other hand, the analytical examination of the solution used for the impregnation of the test specimens which was left over shows that the composition of the treatment agent does not change during the treatment. From this, it will be seen that both the binder and the wood preservative penetrate into the test specimens.

If the samples impregnated with the treatment agents 1-4 according to the invention are stacked on top of each other, they do not stick together on the contact surfaces, i.e. the binder exhibits the necessary penetration behavior and is not secreted on the surface of the samples.

Furthermore, it appears from the table that with the treatment agents 1-4 according to the invention significantly larger proportions of PCP can be introduced into the test specimens than with the treatment agent A used for comparison (PCP dry matter uptake).

The treatment agents according to the invention are also better than corresponding treatment agents according to the closest state of the art, as described in DE-A 30 26 300, as these do not even meet the requirements for a high absorption capacity for the non-water-soluble wood preservative (achievable concentration of the agent in aqueous treatment agent) .

Claims (1)

Aqueous treatment agent for wood containing (1) a water-soluble or water-dispersible, oxidatively drying binder, which has a double bond content corresponding to an iodine number of _> 100 [g iodine per 100 gj, on the basis of an optionally modified 1,3-butadiene polymer by isomerization, partial cyclization or partial hydrogenation which has <_>> 70 mole percent structural units obtained by polymerization of 1,3-butadiene and <_ 30 mole percent structural units obtained by polymerization -seration of other copolymerizable 1,3-dienes and α-unsaturated alkenes and a relative molecular mass (Mn) of 500-6,000, (2) a non-water-soluble, organic wood preservative resp. a mixture of such and (3) optional additives common in the impregnation and varnishing technique, as pore-closing additives do not occur, characterized in that (4) the binder fulfills the additional criterion that it is a polymer which carries amino groups, but no quaternary ammonium groups and has a content of > 50-600 mg atoms of titratable amine nitrogen per 100 g, and that (5) the treatment agent contains acid and has a pH value of 2-8, the control strength and the amount of acid (the degree of neutralization) on the one hand, and the basicity and the amount of the amino groups on the other hand, being adjusted accordingly successively that the binder is water-soluble or water-dispersible.