FI65360C - FUNGISTATISK AEMNESKOMPOSITION. - Google Patents

Description

65360

This invention relates to a fungistatic composition, and more particularly to a composition suitable as an anti-bleaching and anti-mold agent for sawn timber. In particular, bluing, mold and rot fungi are considered to be harmful fungi for the preservation of timber.

It is known from Finnish patent 50417 to use organic thiocyanates to prevent the microbiological contamination of a spoilable organic substance by the action of a microorganism and to prevent the formation of mucus in aqueous liquids in contact with such a substance.

However, the effectiveness of this substance has proven to be relatively weak when tested as an anti-bluing and anti-mold agent for wood and as a preservative for paints and the like.

It is also known from Finnish patent 51698 to use substituted 3-isothioazolones as fungicides, algae and bacteria. These substances have not been tested to prevent wood from becoming blue.

It is therefore an object of the present invention to provide a fungistatic composition for treating wood and in particular for preventing bluing and mold.

The main features of the present invention appear from the appended claim 1.

Thus, it has now surprisingly been found that mixtures of the above-mentioned substances known per se give good results when 65360 are used as a mixture to prevent wood bluing and mold.

Thiocyanomethylthiobenzothiazole (TCMTB) is used as the organic thiocyanate and 2-n-octyl-4-isothiazolin-3-one (OIT) is preferably used as the 3-isothiazolone. The mixture ratio of organic thiocyanate to 3-isothiazolone is preferably between 5: 1-2: 1 and very good results have been obtained when the mixture ratio has been 3: 1-2: 1, for example 2.7: 1.

The compositions according to the invention can be used as solutions, emulsions, slurries or dusts. For wood preservative treatment, emulsions and thickeners have proven to be good product forms.

At the same time, necessary and desired additives, such as paint, corrosion inhibitors, binders and antifreeze agents, can be used in the composition.

In the accompanying drawing, the degree of deterioration measured in the mini-board test is shown as a function of the mixture ratio of the two components of the fungistatic material mixture used. The mini-board test is described in more detail in the examples below, and thiocyanomethylthiobenzothiazole (TCMTB) and 2-n-octyl-4-isothiazolin-3-one (OIT) in various mixing ratios have been used as components in the mixture. The solid straight line drawn in the figure represents the calculated degree of pollution and the dashed line the degree of pollution actually obtained with different mixture ratios. It is clear from the drawing that the fungistatic composition according to the invention always has a degree of contamination below the calculated degree of contamination, which proves that the mixture according to the invention has a synergistic effect.

The invention is described in more detail below by means of examples.

Example 1 This example illustrates the ability of the active ingredient mixture 3 65360 of the invention to effectively control fungi causing bluetongue, mold and decay.

In the experiment, three active ingredient mixtures A, B, C in different concentrations have been tested by the mini-board method and the mixtures have been compared with each other. The reference substances were mixtures B and C with previously known fungicides alone.

Experimental arrangements: 1 x 5 x 30 cm mini-boards sawn from pine surface wood were immersed in half in the protective agent solution to be tested in each case for 20 seconds. Simultaneously, 5 parallel experiments were performed.

Immediately thereafter, the boards were drained in a vertical position for 20 seconds on top of the immersion vessel and allowed to dry in a vertical position for 30 min. The boards were then treated with a fungal suspension. The following bluish, mold and rot fungal suspension was used in the experiment:

Ceratocystis pilifora Z 11 Sclerophoma entoxylima Z 17 Pullularia pullulans U 2 Aspergillus niger Penicillium expansum Cladosporium cladosporioides Peniophora gigantea

One medium for every 1 liter of water.

The suspension was placed in a homogenizer for about 10 minutes before use. With the fine suspension thus obtained, the mini-boards were sprayed wet on both sides. The sprayed mini-boards were stacked on top of each other in a clean plastic box, in layers. The layers were separated. Plastic was placed on top of the box and the box was kept at a constant room temperature for the duration of the experiment.

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Inspections were performed 2 and 3 weeks after the start of the experiment. In the review, the untreated so-called "zero head" and the protective-treated head of each mini-board were judged separately. The degree of contamination was marked according to the following scale:

Degree of contamination 0 clean 1 signs of growth 2 little growth 3 much growth 4 full growth

The preservative efficacy number (TL) used in the experiments is calculated as follows:

The sum of the pollution levels of all mini-boards treated with the same preservative solution is divided by the sum of the corresponding zero-end pollution levels. With an efficiency number of 0.2 and below, the effectiveness of the preservative mixture can be considered good.

The following mixtures of substances were used (amounts given in% by weight): Mixture A

TCMTB (80%) 20% OIT (45%) 20% solvents, emulsifiers, etc. 60%

Seos B

OIT (45%) 40% solvents etc. 60%

Seos C

TCMTB (80%) 40% solvents etc. 60% 65360

The TCMTB used in mixtures A and C is an organic thiocyanate according to Finnish patent 50417, which is a fungicide known per se (thiocyanomethylthiobenzothiazole).

The OIT used in mixtures A and B is a 3-isothiazolone derivative according to Finnish patent 51698, which is also a fungicide known per se (2-n-octyl-4-isothiazolin-3-one).

The following Table 1 shows the test results:

table 1

Pleat- Bags- Used- _2 weeks_3 weeks_ prepared by the batch- _batch no_ batch no_

No. substance quantity 1 2 3 4 5 TL12345TL

1 A 0.2% 3-4 3-4 3-4 3-4g 0-2 0.67 3-4 3-4 3-4 3-4 2-4 0.70 2 A 0.5% 2- 4g 2-4 2-4g 2-4g 3-4g 0.55 3-4 3-4 3-4 3-4 3-4 0.75 3 A 1.0% 0-4 l-4g l-4g 0 -2 l-4g 0.17 2-4 2-4 2-4 1-4 3-4 0.50 4 A 1.5% l-4g l-4g l-4g l-4g l-4g 0.25 1-4 2-4 2-4 3-4 2-4 0.50 5 A 2.0% 1-4 1-4 1-4 l-4g 0-2 0.22 2-4 1-4 2- 4 3-4 0-4 0.40 6 B 1.0% 2-4 2-4g 2-4 2-4 1-4 0.45 3-4 3-4 2-4 3-4 3-4 0 .70 7 C 1.0% 1-4 0-2 l-4g l-4g l-4g 0.22 2-4 l-4g 2-4 2-4 2-4 0.45

In the review, the first number indicates the treated part and the second number the controlled degree of contamination (0-4).

g = only the fungus Peniophora gigantea was present in the treated part of the plate.

From the results, it can be concluded that the best result of the studied formulations, considering the concentration, was given by Formulation No. 3.

Example 2

In a manner similar to Example 1, a mixture of fungicides known per se was studied: thiocyanomethylthiobenzothiazole or TCMTB and

- 2-n-octyl-4-isothiazolin-3-one or OIT

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TCMTB accounted for 12% and OIT for 4.5%.

In addition, solvents and the like were used to obtain a water-emulsifiable product.

In experiments similar to e.g. 1, efficiency values (TL) were obtained:

Table 2

Mixture Application Rate Result TL

TCMTB + (2% 0.7 OIT j1% 1.64 (0.5% 2.0

Comparative test i2% 1.80 0.5% 2.00 i'2% 2.00 0.5% 2.30

Without any active ingredient 4.0

Example 3

The mixture according to the invention (TCMTB + OIT) was tested against the bluing, mold and rot fungi of the boards using a freshly sawn pine board measuring 25 x 100 mm and 2-4 m long. The mixture contained 12% TCMTB and 4.5% OIT and active ingredient concentrations in the mixture were 0.5%, 1.0% and 2.0%.

Shelter handling and storage of boards

The freshly sawn boards were numbered and dipped in preservative solutions. The different treatment groups usually included 50 boards. Subsequent treatments included 100 boards. After the preservative irrigation, half of these batches of 100 boards were dried in a sawmill dryer, i.e. 50 pieces. All experimental batches were bundled into their own bundles of 50 pieces. Fresh boards, which also included an untreated control bundle, were stored under a canopy for 5 weeks until the mid-term inspection.

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The dried bundles were in the sky. After the mid-term inspection, all bundles were in the sawmill area without a roof or other protection.

Inspections of test specimens The intermediate inspection was performed 5 weeks after the start of the test and the final inspection almost 4 months after the start of the test. The boards were judged one by one by inspecting both flaps of the board. Only the worse lape was taken into account in the review. The rating scale was as follows: 0 clean 1 only a few bluish, mold or rot spots 2 slight bluish, mold or rot 3 moderate bluish, mold or rot 4 abundant bluish, mold or rot (at least half the area of the patch)

The review also noted the quality of the contamination: H mold 5 bluish L rot R brown color defect that may be caused by Cephaloascus mold together with bacteria.

From the values obtained in the inspections, the average pollution rates of the test groups were calculated in Table 1. In addition, the numbers of test boards in the different pollution categories were calculated from the test lots in Tables 3 and 4.

Untreated boards were badly damaged during the first 5 weeks. At the end of the experiment, they were very badly contaminated with bluing, mold, and rot fungi.

At the mid-term inspection, only two had small mold spots on the dried boards and the others were clean. The treatments had kept the mushrooms well away.

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Based on the final inspection, it can be said that the material mixture according to the invention protected the boards well from pollution.

The 2% alloy solution repelled rot fungi.

Table 3

Averages of pollution levels of test boards.

T = fresh, K = dried boards, H = mold, S = bluish, L = rot, R = brown discolouration Treatment Interim inspection according to the invention Final inspection with a mixture of substances Silicon grade Defective grade Silicon grade Defective grade (TCMTB + OIT) _ _ _

0.5% T 0.22 LHS 2.0 HSLR

1.0% T 0.06 S 1.64 HSL

KO 1.16 HSL

2.0% TO 0.7 HSR

Untreated T 3.78 HSL 4 SHL

Table 4

Distribution of test boards in grading categories 0-4 in the mid-term review. T = fresh, K = dry.

Processing Number of test boards in different classes (TCMTB + OIT) g_i 2 3_4

0.5% 41 7 2 0 O

1.0% T 48 1 1 0 0 K 50 0 O 0 0 2.0% 50 00 0 0 Not processed 012 4 43 65360

Table 5

Distribution of test boards in evaluation categories 0-4 in the final inspection. T = fresh, K = dry.

Handling Number of test boards in different categories (TCMTB + ÖIT) 01234 0.5% T 12 6 11 12 9 1.0% T 15 11 10 5 9 K 21 10 11 6 2 2.0% T 28 10 11 1 0 Not processed TOO 0 0 50

Claims (4)

65360 A fungistatic composition for treating wood, characterized in that it simultaneously contains thiocyanomethylthiobenzothiazole and at least one substituted 3-isothiazolone of the general formula rt ° in which Y is C 1 -C 6 alkyl. Fungistatic composition according to Claim 1, characterized in that the substituted 3-isothiazolone is 2-n-octyl-4-isothiazolin-3-one. Fungistatic composition according to Claim 1 or 2, characterized in that the weight ratio of thiocyanomethylthiobenzothiazole to 3-isothiazolone in the mixture is from 5: 1 to 2: 1. Fungistatic composition according to one of the preceding claims, characterized in that the weight ratio of thiocyanomethylthiobenzothiazole to 3-isothiazolone in the mixture is from about 3: 1 to 2: 1, preferably from about 2.7: 1.