JPH0432722B2 - - Google Patents

Description

[Detailed description of the invention]

(a) Object of the invention (industrial application field) The present invention relates to a wood preservative. More specifically, the present invention relates to a wood preservative that can prevent or suppress the decay of wood caused by Quercus vulgaris, Versicolor, Versicolor, and the like. (Prior Art) In recent years, with the diversification of methods of using wood and changes in lifestyles, the need for preservatives and fungicides for wood has become increasingly high. Particularly in recent residential environments, wood used for foundations, foundations, etc. is becoming a problem as it rots in a short period of time due to wood-decaying fungi such as Ophthalmia nigra, Porphyra nigra, and C. versicolor. In this regard, various proposals have been made for agents (wood preservatives) for controlling wood-decaying fungi. The performance required of these wood preservatives is that they have strong bactericidal properties against wood-decaying fungi that cause rot to the inside of the wood, even if they have no practical effect on molds that harm the surface of the wood. . Therefore, it is currently impossible to predict whether even chemicals with insecticidal or fungicidal properties can be used against such wood-decaying fungi. In particular, the evaluation of whether it can be used as a wood preservative is based on Japanese Industrial Standards (JIS) A-
9302 and/or Japan Wood Preservation Association Standards (JWPA) No. 1, but for example, TCP (trichlorphenol) Na salt, which is well-known as a fungicide, In addition to toxicity, it does not satisfy such basic performance and is not suitable for practical use. From this perspective, wood preservatives that have been proposed to date include organic agents such as phenolic compounds, organic halogen compounds, organotin compounds, naphthenic acid compounds, and tar compounds, as well as CCA.
Inorganic agents are known, such as a mixture of a copper compound, a chromium compound, and an arsenic compound, and a Wolman salt type (a mixture of a fluorine compound, a chromium compound, and a phenol). (Problems to be Solved by the Invention) However, the conventional agents do not necessarily have a sufficient preservative effect, and in particular, there is a problem in that they cannot sufficiently suppress the damage caused by the three types of wood-decaying fungi mentioned above: A. nigra, A. nigra, and C. versicolor. Ta. The present invention aims to provide a novel wood preservative that exhibits a strong pesticidal effect on Quercus vulgaris, Versicolor, Versicolor, and the like. (b) Structure of the invention Thus, according to this invention, the formula (): A wood preservative is provided which contains 2-(thiocyanomethylthio)benzothiazole represented by the formula () and methylene bisthiocyanate represented by the formula (): NCS- _CH2- SCN () as active ingredients. 2-(Thiocyanomethylthio)benzothiazole (hereinafter referred to as
TCMTB itself is generally known to have an inhibitory effect on molds, as shown in Japanese Patent Publications No. 45-14298 and No. 49-21767, etc., but its effectiveness as a wood preservative is unknown. The other active ingredient, methylene bisthiocyanate (hereinafter referred to as MBTC), is known to have antimicrobial activity, for example, according to Chemical Abstracts Vol. 51, Columns 13302 b-c (1959), but TCMTB Similarly, its effectiveness as a wood preservative is unknown. The wood to which the wood preservative of the present invention is applied is generally wood used for construction, civil engineering work, and fiber raw material for manufacturing industrial products such as paper and pulp. Examples include red pine, cedar, and beech, which are prone to rot fungi. When the wood preservative of the present invention is actually used on wood, alcohol solvents such as ethanol and isopropyl alcohol, hydrocarbon oils such as kerosene, xylene and toluene, glycol solvents such as ethylene glycol and butyl cellosolve, and dimethylformamide are used. It is suitable for use by dissolving it in an organic solvent. Furthermore, by blending these with an anionic surfactant, a nonionic surfactant, a cationic surfactant, etc., it can be diluted with water and used as an emulsion. These can be appropriately selected depending on the purpose of use and the method of treating wood. The concentration of the organic solvent solution or aqueous emulsion of TCMTB and MBTC may be selected as appropriate in the same manner as above, but for example, in the case of pressure injection method or vacuum treatment method, approximately 0.05 to 1% is usually suitable. , approximately 0.2 when using surface treatment such as coating or dipping.
The content is preferably about 2%, and when mixed into adhesives or paints, the content is about 0.1 to 2.0%. In addition, the addition ratio of TCMTB: MBTC (weight ratio)
is usually 3:7 to 7:3 to achieve the above concentration.
Preferably, the ratio is 1:2 to 2:1. The wood preservative of the present invention containing the above-mentioned TCMTB and MBTC as active ingredients exhibits a strong control effect against the above-mentioned wood-decaying fungi. Of course, the wood preservative of the present invention can be used in combination with many existing wood preservatives and insect repellents, such as chlorine compounds such as chlordane and daconyl, organophosphorus compounds such as fenitrothion and diazinon, and organotin compounds. It is also possible to use a mixture of a compound, a carbamate compound, and a boron-based or fluorine-based compound. The invention will now be illustrated by examples. (Example) TCMTB and MBTC were tested for their antiseptic efficacy against various wood-decaying fungi. An aqueous emulsion containing 20% of the above two components prepared by mixing the test compounds at a ratio of TCMTB:MBTC=1:1 (weight ratio) with a nonionic surfactant and water is described below ( According to the method for testing the preservative efficacy of wood preservatives specified in Japan Wood Preservation Association Standards (JWPA) No. 1, tests were conducted at various concentrations shown in Table 1. For comparison, the cases of TCMTB alone and MBTC alone produced in the same manner as above are also shown in Table 1. The wood-decaying fungi tested were as follows. Porphyra japonica Versicolor Physalis nigra 1 Preparation of test pieces Sapwood pieces of three species: Japanese cedar, Japanese red pine, and beech (5 x 20 x 40 mm, with a straight grain surface and the end surface sealed with room-temperature curing epoxy resin) ,
The above aqueous emulsion adjusted to various concentrations of 0.5, 0.75, 1.5 and 2.0% is applied uniformly with a brush so that it adheres at a rate of 110 ± 10 g/ ^m2 , and after air drying, no weathering operation is performed. After the latter was treated according to the JWPA weathering method, the two groups were dried at 60°C until the sapwood reached a constant weight and used as test pieces. 2 Preservation test (JWPA preservative efficacy test method) and results The medium base is JIS modified medium (peptone = 0.5%, malt extract = 1%, glucose = 2.5%, KH ₂ PO ₄ = 0.3
%, MgSO ₄ .7H ₂ O = 0.2%), and the wood-decaying fungi were cultured in the medium, and test cultures were performed using the following combinations of test specimens of three tree species and the wood-decaying fungi.
The test culture was 26±2 for C. versicolor and O.
The preservative efficacy value was determined for Namida mushrooms at 20±2°C for a period of 56 days. The results are shown in Table 1. The preservative efficacy value was calculated using the following formula. Preservative efficacy value = Difference in average weight loss rate between untreated and chemical treated specimens / Average weight loss rate of untreated specimens x 100 However, the test wood-decaying fungi applied to the sapwood pieces of the three tree species were cedar, japonica japonica, and Beech - Versicolor and Japanese red pine - Namidatake. When comparing the decay-inhibiting concentration and decay-inhibiting absorption amount of wood preservatives, this combination is determined by determining the high preservative efficacy value for the combination that results in a high weight loss with untreated wood and comparing the results. This was an attempt to evaluate efficacy more comprehensively.

[Table] As is clear from Table 1, when compared with each test compound alone at a preservative efficacy value of 90 or higher, which is considered to have a substantial preservative effect, for example, the 0.75% concentration of TCMTB alone It can be seen that most of the compounds of the present application have a value of 90 or more, whereas all of them have a value of 90 or less, and no substantial preservative effect is obtained. Furthermore, the combination of TCMTB, which has a worse preservative effect than MBTC, is considered to be diluting the MBTC alone in terms of concentration and effectiveness; nevertheless, the preservative efficacy value is much higher than that of MBTC alone. This resulted in an increase in This excellent effect is thought to be based on the synergistic effect of using each active ingredient in combination. (c) Effects of the invention As described above, the wood preservative of the present invention exhibits an extremely excellent preservative effect against various wood-decaying fungi even when added in a small amount.

Claims (1)

[Claims] 1 Formula (): 2-(Thiocyanomethylthio)benzothiazole represented by: and methylene bisthiocyanate represented by the formula (): NCS-CH ₂ -SCN () as active ingredients in a weight ratio of 1:2 to 2:1. Contains wood preservatives.