GB2152816A - Wood preservative - Google Patents

Abstract

A stable non-toxic wood preservative ready for use contains Cu-8-hydroxy quinolate, C6-C18-alkyl phenol and/or an alkoxylated derivative thereof, e.g. nonyl phenol, C6-C18-alkyl benzene sulfonic acid, e.g. dodecyl benzene sulfonic acid, and optionally a fungicidal organo-tin compound, dissolved in an aliphatic hydrocarbon solvent, e.g. white spirit. The molar ratio of Cu-8-hydroxy quinolate to C6-C18-alkyl benzene sulfonic acid is from 1:2 to 1:3, and the molar ratio of Cu-8-hydroxy quinolate to C6-C18-alkyl phenol and/or an alkoxylated derivative thereof being not more than 1:4. It is used to protect wood against fungi, rot, blue stain, mould and insects.

Description

SPECIFICATION A Stable Wood Preservative Ready for Use and Containing Cu-8-hydroxy Quinolate Dissolved in a Hydrocarbon Solvent and a Concentrate for Use in the Preparation Thereof The present invention relates to a stable wood preservative ready for use and containing Cu-8-hydroxy quinolate and C6-C18-alkyl phenol and/or an alkoxylated derivative thereof dissolved in a hydrocarbon solvent. The invention also relates to a wood preservative concentrate containing Cu-8-hydroxy quinolate for use in the preparation of the wood preservative of the invention by dilution.

It is known to use Cu-8-hydroxy quinolate as active ingredient in wood preservatives. Cu-8-hydroxy quinolate is active against both wood destroying fungi and other rot, blue stain, mould and insects, e.g.

termites. Moreover, as Cu-8-hydroxy quinolate has a low toxicity (LD50=about 5400 mg/kg), it is particularly suitable for use in wood preservatives.

DE-OS No. 2,647,952 discloses an anti-microbial concentrate comprising Cu-8-hydroxy quinolate, alkyl phenol, and heavy aromatic naphtha, cf. Example 18 of the above-mentioned DE-OS. By dilution of the concentrate with white spirit ready-for-use wood preservatives are prepared.

However, these known ready-for-use wood preservatives are not stable, as a precipitation of solid matter in the ready-for-use wood preservative occurs when stored.

It has now been found that by the use of Cu-8-hydroxy quinolate, Ca-C18-alkyl phenol and/or an alkoxylated derivative thereof and C6-C18-alkyl benzene sulfonic acid in specific ratios a ready-for-use stable wood preservative can be prepared, which is stable even when stored for a long time.

Accordingly, the wood preservative of the invention is characterized by also comprising C6-C18-alkyl benzene sulfonic acids, the hydrocarbon solvent being a predominantly aliphatic hydrocarbon solvent, the molar ratio of Cu-8-hydroxy quinolate to C6-C18-alkyl benzene sulfonic acid being from 1:2 to 1:3, and the molar ratio of Cu-8-hydroxy quinolate to C6-C18-alkyl phenol and/or an akoxylated derivative thereof being not more than 1:4.

The ready-for-use wood preservative of the invention is a completely stable solution, which keeps its stability even when stored for a long time and subjected to the action of heat, cold or moisture without precipitation of Cu-8-hydroxy quinolate.

The wood preservative concentrate of the invention is characterized by also comprising C-C18-alkyl benzene sulfonic acids, the molar ratio of Cu-8-hydroxy quinolate to C6-C18-alkyl benzene sulfonic acid being from 1:2 to 1:3, the molar ratio of Cu-8-hydroxy quinolate to Ca-Cis-alkyl phenol and/or an alkoxylated derivative thereof being not more than 1:4, and by being soluble in a predominantly aliphatic hydrocarbon solvent.

In practice it is particularly advantageous to use nonyl phenol as the C6-C18-alkyl phenol and dodecyl benzene sulfonic acid as the C6-C18-alkyl benzene sulfonic acid as well as white spirit as the hydrocarbon solvent.

In order to obtain a broader spectrum of activity, in particular against Cu-resistant fungi of the Species Poria, it may be advantageous to add a small amount of a fungicidal organotin compound, in particular bis-tri-n-butyl tin oxide or an oil-soluble derivative thereof.

The wood preservative concentrate of the invention can be diluted to stable ready-for-use solutions with hydrocarbon solvents of different types, and the choice of solvents is not critical. Examples of such hydrocarbon solvents are aliphatic petroleum distillates ("high flash naphtha") having a content of aromatic hydrocarbons of 118 percent and a boiling interval of 18(r--230"C, which petroleum distillates are generally used for vacuum impregnation liquids and coating liquids. Furthermore, aliphatic solvents having a low aromatic content can be mentioned. Solvents of this type are increasingly used for environmental reasons.

The Cu-8-hydroxy quinolate used can be added as such or prepared in situ by reacting a copper compound, e.g. cupric hydroxide, with 8-hydroxy quinoline.

The wood preservative concentrate of the invention can be prepared by gradually adding Cu-8-hydroxy quinolate or its components to the alkyl phenol containing alkyl benzene sulfonic acid with stirring and heating to about 100120 C.

The ready-for-use, stable wood preservative of the invention can be used in e.g. vacuum impregnation plants and can be applied to the wood by coating or spraying. An excellent protection of wood against wood destroying microorganisms is obtained, which will be apparent from the following Test Examples.

The invention is further illustrated by means of the following Examples.

EXAMPLE I A. Preparation of Concentrate To a mixture of 202.5 g of lauryl benzene sulfonic acid and 787.5 g of p-nonyl phenol, 112.5 g of Cu-8-hydroxy quinolate were gradually added with stirring and heating to 1 100C. 1102.5 g of concentrate were obtained as a dark brown viscous solution.

B. Preparation of Ready-For-Use Wood Preservative 551.3 g of the concentrate prepared sub A were diluted with 7.5 kg of white spirit to obtain a clear, yellow brown, ready-for-use, stable wood preservative containing Cu-8-hydroxy quinolate in normal concentration (x). Moreover, from the concentrate prepared above ready-for-use, stable wood preservatives containing Cu-8-hydroxy quinolate in concentrations of x plus 50 percent of x and x minus 50 percent of x were prepared. The prepared ready-for-use, stable wood preservatives were used in the following Test Examples, in which the designation Cu-8 is used for copper-8-hydroxy quinolate.

EXAMPLES Il-VI Wood preservatives were prepared using substantially the same procedure as in Example I. The wood preservatives of Examples ll-lV comprised tri-n-butyl tin naphthenate as active compound in addition to Cu-8-hydroxy quinolate. In Example VI ethoxylated nonyl phenol was substituted for p-nonyl phenol. The amounts of the individual components will be apparent from the following Table.

TABLE Example No.

Ingredient 2 3 4 5 6 Cu-8 0.5 0.5 0.5 1 0.5 DBSA 1 1 1 2 1 NP 3.5 3.5 3.5 7 TBTN 0.2 0.2 0.2 - - Petroleum resin 5 - - - - Tall oil resin - 10 - - Shellsol H 89.8 84.8 94.8 90.0 94.5 NP-2EO - - 4 - 4 In the above Table the figures indicate percent by weight, and the following abbreviations are used: Cu-8=copper-8-hydroxy quinolate DBSA=lauryl benzene sulfonic acid (n-dodecyl benzene sulfonic acid) NP=p-nonyl phenol TBTN=tri-n-butyl tin naphthenate Shellsol H is a predominantly aliphatic solvent NP-2 EO=p-nonyl phenol ethoxylated by 2 moles of ethylene oxide.

The prepared wood preservatives are completely stable, even when stored for a long time, and they do not give any appreciable tint to the wood samples treated therewith.

Comparison Example I 0.5 g of Cu-8-hydroxy quinolate, 7.5 g of p-nonyl phenol and 2.5 g of toluene were heated to 80"C to form a solution, which was diluted with Shellsol H. The solution was immediately stable, even after addition of 0.2 percent of water. The solution was left for 60 hours, whereafter Cu-8-hydroxy quinolate had precipitated.

Comparison Example II 1 g of Cu-8-hydroxy quinolate, 1 g of lauryl benzene sulfonic acid, 5 g of p-nonyl phenol, and 3 g of toluene were heated, and the mixture was diluted to 200 g with Shellsol H. The solution was stable and had a good water-resistance (0.2 percent of water). The solution was left for 60 hours, whereafter Cu-8-hydroxy quinolate had precipitated in the solution.

Comparison Example Ill 1 g of Cu-8-hydroxy quinolate, 3 g of lauryl benzene sulfonic acid, and 7 g of p-nonyl phenol were heated, and the mixture was diluted to 200g with Shellsol H, whereby the liquid got cloudy at once due to the formation of an emulsion of lauryl benzene sulfonic acid.

Test Example I Mycological testing-Basidiomycet test at penetration (cf. H. P. Sutter, 1978; 221-223) on impregnated samples (20 cm x10 cmx5 cm) of Scotch pine (Pinus silvestris L.) with concentrations of 0 (white spirit), normal concentration (x) and x plus/minus 50 percent. Pickup level 0 and 23 kg/cubic metre of sapwood.

Process parameters: Pre-vacuum without liquid (pressure 50 cm Hg for 10 minutes), filling in vacuo, pre-vacuum with liquid (pressure 50 cm Hg for 10 minutes), absorption (pressure 1 atm for 10 minutes), draining. Post-vacuum without liquid: Pressure 72 cm Hg for 30 minutes. Fixing and evaporation: 1 week at room temperature (about 20"C).

Test fungi: Cellar fungus (Coniophora puteana (Fr.) Karst., strain BAM Ebw 15) and Gloeophyllum trabeum (Fr.) Murrill strain BAM 109. Dilution: White spirit. Sterilization: Radiation sterilization with 5 Mrad.

Exposure: 1 sample, size 50 mmx50 mm x4 mm in Petri-dish (q) 9 cm) with 4 repetitions. Incubation at 22+2 C and 70+5 percent of relative humidity (R.H.). Exposure time: 6 weeks.

The effect of the tested wood preservative was established as an outer sapwood zone, no penetration having occurred.

Test Example II Mycological testing against mould fungi on samples of Scotch pine (Pinus silvestris L.) of the size 2 cmx9.5 cm 18cm. The composition had been applied on all sides by means of a brush with difference weighing in an amount of about 650 g/square metre in concentrations of 0 (white spirit), normal concentration (x) and x plus/minus 50 percent. After fixing and evaporation for 1 day at about 20"C the samples were exposed in a mould-infected, closed hermetic room at about 25"C and 90 percent R.H.

Repetition: 5+1 untreated control. Exposure time: 4weeks.

After 4 weeks it was established that Cu-8 in the concentration of "normal" (x), applied in an amount of 650 g/square metre, had effectively prevented attacks from mould fungi.

Test Example Ill Mycological testing against blue stain on samples of Scotch pine (Pinus silvestris L.) of the size 2 cox9.5 cm x 18 cm.

The composition had been applied on all sides by means of a brush with difference weighing in an amount of about 650 g/square metre in concentrations of 0 (white spirit) normal concentration (x) and x plus/minus 50 percent. After fixing and evaporation for 1 day at about 20"C the samples were exposed on a meadow, sheltered and in the shade. Repetition: 5+1 untreated control. Exposure time: 4 weeks.

After 4 weeks it was established that Cu-8 in the concentration of normal (x) minus 5G percent, applied in an amount of 650 g/square metre, had effectively prevented attacks from blue stain.

Claims (12)

1. A stable wood preservative ready for use, which wood preservative comprises Cu-8-hydroxy quinolate, C6C18-alkyl phenol and/or an alkoxylated derivative thereof, C6-C18-alkyl benzene sulfonic acid(s) and a predominantly aliphatic hydrocarbon solvent, the molar ratio of Cu-8-hydroxy quinolate to C6-C18-alkyl benzene sulfonic acid(s) being in the range of from 1:2 to 1:3 and the molar ratio of Cu-8-hydroxy quinolate to C6-C18-alkyl phenol and/or an alkoxylated derivative thereof being not more than 1:4.

2. A wood preservative according to claim 1, wherein the C6-C18-alkyl phenol is nonyl phenol and the C,,-C18 alkyl benzene sulfonic acid is dodecyl benzene sulfonic acid.

3. A wood preservative according to claim 1 or 2, wherein the hydrocarbon solvent is white spirit.

4. A wood preservative according to claim 1,2 or 3, which further comprises a fungicidal organotin compound.

5. A wood preservative according to claim 4, wherein the fungicidal organotin compound is bis-tri-n-butyl tin oxide or an oii-soluble derivative thereof.

6. A wood preservative concentrate which comprises Cu-8-hydroxy quinolate, C6C,8-alkyl phenol and/or an alkoxylated derivative thereof and C6-C18-alkyl benzene sulfonic acid(s), the molar ratio of Cu-8-hydroxy quinolate to C6C,8-alkyl benzene sulfonic acid(s) being in the range of from 1:2 to 1:3 and the molar ratio of Cu-8-hydroxy quinolate to C6-C18-alkyl phenol and/or an alkoxylated derivative thereof being not more than 1:4, the concentrate being soluble in a predominantly aliphatic hydrocarbon solvent.

7. A concentrate according to claim 6, wherein the C6-C18-alkyl phenol is nonyl phenol and the C6-C18-alkyl benzene sulfonic acid is dodecyl benzene sulfonic acid.

8. A concentrate according to claim 6 or 7, which further comprises a fungicidal organotin compound.

9. A concentrate according to claim 8, wherein the fungicidal organotin compound is bis-tri-n-butyl tin oxide or an oil-soluble derivative thereof.

10. A stable wood preservative ready for use, substantially as described in any one of foregoing Examples 1 to 6.

11. A wood preservative concentrate, substantially as described in any one of foregoing Examples 1 to 6.

12. Any novel feature or combination of features described herein.