NZ241393A

NZ241393A - Mildewproofing composition for timber comprising a mixture of 4,5-dichloro-2n-octyl-4-isothiazolin-3-one and 2,4,6-trichlorophenol

Info

Publication number: NZ241393A
Application number: NZ24139392A
Authority: NZ
Inventors: Sugai Yoshiaki; Ueda You
Original assignee: Rohm & Haas
Priority date: 1991-01-31
Filing date: 1992-01-24
Publication date: 1994-04-27
Also published as: JPH04244003A; MY108690A

Description

New Zealand Paient Spedficaiion for Paient Number £41 393 241393 Prioiity Ds; .... V3A.....

Ccrnpt&te Tp Circs' , (;Vpa^A.9>.- , n "" n t 2 7"APR 1994 Publtcat-cn Date: ^ ...........

P.O. Journal, No: .... i ? p% r*i v r> i''i ? n f*. ^ HQ mmmuit No.: Date: NEW ZEALAND IJJ£- PATENT PATENTS ACT, 1953 I 2* JAN 1992 RECEIVED COMPLETE SPECIFICATION MILDEWPROOFING AGENT FOR TIMBER We, ROHM AND HAAS COMPANY a Corporation organised and existing under the laws of Delaware, United States of America, of Independence Mall West, Philadelphia, Pennsylvania 19105, United States of America hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- (followed by page la) ■ 1*,- MILDEWPROOFING AGENT FOR TIMBER This invention relates to a mildewproofing agent for timber. 2,4,6-trichlorophenol (hereinafter to be called TCP) is an agent for timber, but it has drawbacks such as limited antibacterial spectrum, weak effects when used in a low concentration, and the occurrence of damage when the concentration is too high. 4,5-dichloro-2n-octyl-4-isothiazolin-3-one (hereinafter DOIO) is also known for such uses, but similarly it has drawbacks such as its cost, which may make it uneconomical.

We have discovered however that a combination of 4,5-dichloro-2n-octyl-4-isothiazolin-3-one and 2,4,6-trichlorophenol unexpectedly have a synergistic effect when employed in combination as a mildewproofing agent.

Accordingly the present invention provides a mildewproofing composition for timber comprising 4,5-dichloro-2n-octyl-4-isothiazolin-3-one and 2,4,6-trichlorophenol in a ratio by weight of from 1:200 to 1:2, preferably from 1:50 to 1:10. In another aspect the invention provides a method of preventing or inhibiting the growth of mildew on timber, comprising incorporating into or onto said timber, in an amount effective to adversely affect said growth, the above composition.

A further aspect of the invention comprises the use of the composition defined above to protect timber against mildew.

EXAMPLES Five test specimens were prepared for each composition shown in Table 1, which composition contained the components in the ratio as shown, by immersing particle boards having dimensions of 3 cm x 3 cm x 0.6 cm in » ' I \ *»■ *'•* t / < * ' - 2 f'AR TiW 2 the composition solution such that composition was taken up by the boards at a rate of 200-250 g/m2.

The prepared specimens were fully air dried and placed on a polyethylene net which was put on PDA agar culture medium in a Petri dish. Mixed spore suspensions prepared from Mildew cultured separately on PDA agar medium and listed below were sprayed over the specimens in an amount of 2 ml each. Each Petri dish was covered and left for culturing in a thermostatic chamber at 26°C for one month. Then, growth of mildew on the specimen surface was observed, and the effect of the composition was evaluated according to the evaluation method below.

Table 1 (parts by weight) Composition TCP DOIO NaOH SAA Water Total A 1.0 0.1 0.2 0.4 Balance 100 B 1.0 0.05 0.2 0.4 Balance 100 C 2.0 0.1 0.4 0.4 Balance 100 D 2.0 0.05 0.4 0.4 Balance 100 E 1.0 0.01 0.2 0.4 Balance 100 F 1.0 0.005 0.2 0.4 Balance 100 G 0.5 0.1 0.1 0.4 Balance 100 H 0.5 0.05 0.1 0.4 Balance 100 I 0.2 0.1 0.05 0.4 Balance 100 J* 2.0 - 0.4 0.4 Balance 100 K* 1.0 - 0.2 0.4 Balance 100 L* 0.5 - 0.1 0.4 Balance 100 M* - 0.1 - 0.4 Balance 100 N* - 0.05 - 0.4 Balance 100 TCP: 2,4,6-trichlorophenol DOIO: 4,5-dichloro-2n-octyl-4-isothiazolin-3-one NaOH: Sodium hydroxide SAA: Nonionic surface active agent * : Comparative Example 2413§3 Organisms Aspergillus niger Trichoderma viride Aureobasidium pollulans Penicillum citronum Rhizopus nigricans Evaluation method The mildewed specimens were given marks indicating damage rating according to the following criteria. The aggregate of five specimens was taken to obtain the damage rating X for each treated specimen.

Damage rating criteria 0: No mildew on the surface of specimen 1: Mildew on only side walls of the specimen 2: Mildew on 1/3 or less of the top surface of the specimen 3: Mildew on 1/3 or more of the top surface of the specimen Untreated specimens were also subjected to the same test to obtain a damage rating Xo. A mildewproofing index was calculated for each composition based on the damage rating X of the treated specimen and the damage rating Xo of the untreated specimen from the following formula: Mildewproofing index = Xo -X x 100 Xo Test results thus obtained are shown in Table 2. It can be seen that 1.0 part of TCP (Composition K*) and 0.5 part of TCP (Composition L*) have approximately the same effect as 0.1 part of DOIO (Composition M*) and 0.05 part of DOIO (Composition N*) respectively. It is also clear that Composition B, which corresponds to a mixture of Composition J* and Composition M* in 2413P ? a ratio of 1:1, and Composition H which corresponds to a mixture of Composition K* and Composition M* in a ratio of 1:1, exhibit quite excellent synergistic effect compared with the compositions of the Comparative Examples.

Table 2 Composition Specimen's damage ratine Damage rating Mildewproofing index A 0,0,0,0,1 1 93 B 0,0,1,1,1 3 80 C 0,0,0,0,0 0 100 D 0,0,0,0,1 1 93 E 0,0,1,1,2 4 73 F 1,2,2,2,3 33 G 0,1,1,2,2 6 60 H 0,0,0,1,1 2 87 I 1,1,2,3,3 33 J* 1,2,2,2,2 9 40 K* 2,2,2,3,3 12 L* 2,2,3,3,3 13 13 M* 2,2,2,3,3 12 N* 2,2,3,3,3 13 13 None 3,3,3,3,3 - 24 1 3 9 3

Claims

WHAT WE CLAIM IS:

1. Mildewproofing composition for timber comprising (a) 4,5-dichloro-2n-octyl-4-isothiazolin-3-one and (b) 2,4,6-trichlorophenol in a ratio of from 1:200 to 1:2 by weight.

2. Mildewproofing composition according to claim 1 wherein the ratio of (a) to (b) is from 1:50 to 1:10.

3. Method of preventing or inhibiting the growth of mildew on timber, comprising incorporating into or onto said timber, in an amount effective to adversely affect said growth, a composition according to claim 1 or 2.

4. Method according to claim 3 wherein the composition is incorporated into or onto the surface of the timber in an amount of from 200 to 250 g/m2.

5. Use of a composition according to claim 1 or 2 to protect timber against mildew.

6. Mildewproofing composition for timber as claimed in claim 1 and substantially as hereinbefore described.

7. Method of preventing or inhibiting the growth of mildew on timber as claimed in claim 3 and substantially as hereinbefore described.

8. Use of a composition to protect timber as claimed in claim 5 and substantially as hereinbefore described. DATED TH1 day ** A. J. PARK.& SON /] (]*>/ per i/ x v a Ia i. y age fr-f- " - 2FEB-?94