DD238808A1 - FUNGICIDIZED COLD BINDERING SILICONE RUBBER ONE COMPONENT PASTE - Google Patents

Abstract

The invention relates to fungicidally treated cold-crosslinking silicone rubber one-component pastes which, in addition to crosslinkers, fillers and catalysts, contain methylene bis (methyl cyanimidodithiocarbonate) as fungicidal active ingredient. They find application in the construction industry and are used in particular in damp indoor rooms, mainly in sanitary area, as jointing compounds.

Description

Field of application of the invention

The invention relates to sealants and adhesives based on cold-curing silicone rubber one-component pastes containing crosslinkers, fillers, catalysts and additionally a fungicidal active ingredient. They are used in the construction industry and are used in particular in damp indoor areas, mainly in the sanitary sector, as jointing compounds.

Characteristic of the known technical solution

The sealants and adhesives based on silicone rubber used in construction, especially in the sanitary sector, as well as other polymer materials, are subject to a fault! through mushrooms. The fungal attack both the aesthetic appearance of the sealant surfaces. That manifests itself in a partially permanent discoloration or Verfeckung, as well as the utility properties of the sealant, eg. B. its liability to the Fugenfianken impaired. In addition, by the Mikrobenbefai! a deterioration of hygienic conditions. To avoid the reduction in utility, therefore, fungicidal active compounds such as 2-4-thiazolylbenzimidazole, benzimidazolylalkyl carbamates, 4-1,4-dimethylsulfonyl-2,3,5,6-tetrachloropyridine or dibutyltin diacetate are added to the silicone rubber one-component pastes (also referred to as SEP) , The disadvantage of these drugs is the difficult to produce or high toxicity associated with unpleasant odor (dibutyltin diazetate). Carbamates, e.g. Carbendazim, because of their inadequate effectiveness, require higher use concentrations that are uneconomical. The good activity of these compounds given in the patent DD-AS 138427 at an active ingredient content of 0.1-0.5 wt .-% could not be confirmed by experiments. Other known fungicides such as captan, thiram, zineb, tributyltin oxide, chloroacetamide and 2-mercapfobenzothiazole still have a good effect in the agar plate test, but fail completely in conjunction with the SEP. A particularly difficult problem is the preservation of SEP with high filler content, since due to the adsorptive effect of the fillers, the active ingredients are no longer sufficiently available by diffusion inhibition.

Object of the invention

The aim of the invention is to provide for the construction industry jointing compounds based on cold-curing SEP, which are protected against reduction of their use value as a result of fungal infestation by adding an easily accessible, highly effective and low-toxic active ingredient.

Explanation of the essence of the invention

It is an object of the present invention to provide a fungicidally-engineered SEP having high utility value properties for the construction industry. It has been found that methylenebis (methyl) cyanimidodithiocarbonate) (Mbmc) is surprisingly well-suited for the fungicidal protection of SEP of the following general formula, with amounts between 0.01% and 1.0% Mbmc, based on the mass of the SEP ensure excellent resistance to fungal attack on cold-curing SEP.

General recipe

Mixture consisting of: 70 to 100 parts of an α , ω-dihydroxypolydimethylsiloxane having a viscosity of 5000 to 100,000 mPa.s., 0 to 30 parts of a dimethyl polysiloxane which is blocked at the ends with trimethylsiloxy, having a viscosity of 50 to 10OOmPa.s., 10 to 200 parts of the usual fillers for rubber pastes and 5 to 10 parts of a curing at room temperature under the action of moisture crosslinking system.

From the water, the active ingredient Mbmc leached out of the crosslinked rubber only very slowly, which is countered over a long time a high infection pressure.

Mbmc shows good compatibility with the components of SEP, d. H. a negative mutual interference of activity and shelf life could not be observed. The good fungicidal activity remains even when training in

SEP obtained with high filler content. - -

In the networked state, no reductions in parameters such as elasticity, adhesiveness, etc. are discernible. Mbmc is low in toxicity and readily accessible from carbon disulfide, cyanamide and common alkylating agents. (DD-WP 221177) The cold-crosslinking SEPs according to the invention are used as sealants or adhesives in construction. They are particularly useful in the sanitary sector, where the impairment of hygienic conditions and the decorative appearance caused by fungal infestation and at the same time adhesion, elasticity, etc., ie the full utility value to be obtained.

-2- 238S08

embodiments

In the tables given below the following examples mean:

Thiram: tetramethylthiuram disulfide DADZ: zinc bis (N-diethyldithiocarbamate)

Mbmc: methylene-bis-fmethyl-cyanimidodithiocarbonat) ι

Captan: N-trichloromethylthio-tetrahydro-phthalimide TBTO: Tributyltin oxide

Carbendazim: N (Benzimidazol-2-yl) -methylcarbamate Zineb: Zinc-ethylene-1,2-bis-dithiocarbamate Example 1 Testing of various microbicidal compounds in agar plate test Agar cooled to 45 ° C. is mixed with the substances to be tested in the corresponding test concentrations added. After solidification, a mixed spore suspension consisting of Aspergillus niger and Penicillium spec were inoculated. The evaluation of the plates incubated at room temperature took place on the 5th and 10th day with the aid of the following rating scheme.

rating scale:

1 = unhindered growth of the fungus (as untreated)

2 = growth slightly inhibited

3 = growth strongly inhibited

4 = no mushroom growth

The rating values to be taken from Table 1 are averages of 4 repetitions.

Table 1 Effect of microbially active compounds on a mixed-spore suspension Active Ingredient Conc. (% AS) Bonitogenic

5th day 10th day

untreated - 1.0 1.0 known active ingredients thiram 2.0 4.0 4.0 1.0 4.0 4.0 0.5 4.0 4.0 0.05 4.0 4.0 0.02 4.0 3.5 0.01 4.0 3.5 dadz 2.0 3.0 2.0 1.0 3.0 2.0 0.5 3.0 2.0 0.1 1.0 1.0 0.05 1.0 1.0 0.02 1.0 1.0 0.01 1.0 1.0 captan 2.0 4.0 4.0 1.0 4.0 4.0 0.5 4.0 4.0 0.1 4.0 4.0 0.05 3.0 3.0 0.02 3.5 2.0 0.01 1.0 1.0 TBTO 2.0 4.0 4.0 1.0 4.0 4.0 0.5 4.0 4.0 0.1 4.0 4.0 0.05 4.0 4.0 0.02 4.0 4.0 0.01 3.0 3.0 carbendazim 2.0 4.0 4.0 1.0 3.0 3.0 0.5 2.5 2.0 0.1 1.0 1.0 π nt% , -Ι Λ - ~. -.! i η __. _ U, UO 0.02 I, VJ 1.0 I , \ J 1.0 0.01 1.0 1.0 Zineb 2.0 4.0 4.0 1.0 4.0 4.0 0.5 4.0 4.0 0.1 4.0 4.0 0.05 4.0 3.5 0.02 4.0 3.5 0.01 4.0 3.5

inventive additive 2.0 4.0 4.0 Apply Now Mbmc 1.0 4.0 4.0 0.5 4.0 4.0 0.1 4.0 4.0 0.05 4.0 4.0 0.02 4.0 3.5 0.01 3.5 3.0

Example 2

Well-acting fungicides (see Example 1) were incorporated into the paste with the following formulation in various concentrations (see Table 2).

Recipe 1:

Mixture consisting of: 70 parts of an α, ω-Dihydroxypolydimethylsiloxans with a viscosity of 5000OmPa. s., 30 parts

a Dimethylsüoxans with a viscosity of 500 mPa blocked at the outer ends with Trimethylsüoxygruppen. s., 50 parts of a filler consisting of precipitated potassium carbonate having a particle size range of about 80% between 1 to 5μίη, 0.01 to 1 parts of a fungicidally active additive and 5 parts of methyltriacetoxysilane as crosslinking component.

The test of this SEP was carried out as follows.

Cardboard strips (2 χ 4cm) were evenly coated with a SEP of Formulation 1 and placed under a fume cupboard for 72 hours to evaporate the acetic acid. Subsequently, the treated strips were infected with a spore suspension consisting of Aspergiiius niger or Penicillium spec. The incubation was carried out at room temperature in a moist chamber (98% relative humidity). After a 15-week incubation period, a macroscopic assessment of fungal infestation was made using the rating scheme below.

rating scale:

1 = heavy vegetation (100 colonies)

2 = medium growth (10-100 colonies)

3 = weak growth (1-10 colonies)

4 = not covered

The effectiveness of the additive according to the invention and the comparison with known active ingredients is shown in Table 2. Table 2 Inhibition of fungal growth by various incorporated drugs Active substance quantity Boniturnoten

i.d. Paste (%) Aspergillus niger Penicillium spec.

3 3 3 3 3 3 4 4 2 3 3 2 1 1 1 3 3 2

4 4 4 3.7

Example 3 Examination of the long-term effect of the fungicidal equipment under water stress

From fungicidal cold-crosslinking SEP Formulation 1, plates of 2-3 mm thickness were poured, which were treated with water for a longer time (10, 30 and 90 days). The pretreated plates were infected with a mixed spore suspension of Penicillium spec and Aspergillus niger and incubated in a humidified chamber. The evaluation was carried out 6 months after infection according to the Boniturschema mentioned in Example 2. Table 3 below shows the results from this test.

known active ingredients 1.0 3 thiram 0.5 3 0.1 2 1.0 3 dadz 0.5 3 0.1 3 1.0 4 captan 0.5 4 0.1 2 1.0 3 TBTO 0.5 3 0.1 2 1.0 1 carbendazim 0.5 1 0.1 1 1.0 3 Zineb 0.5 3 0.1 2 inventive additive 1.0 4 Apply Now Mbmc 0.5 4 0.1 4 0.01 3.7

Table 3 Test of the fungicidal permanent action after leaching of water Active ingredient - active 10 days

substance (%) H ₂ O-treatment.

30 days H ₂ O treatment.

90 days H ₂ O treatment.

known active ingredients 0.5 captan 0.5 thiram 0.5 chloroacetamide inventive additive 0.5 Apply Now Mbmc

1.3 2.3 2.0

4.0

4.0

Step Example! 4 Examination of the fungicidal activity in high or low filled SEP

Pastes of Formulas 2 and 3 listed below were based on the methodology described in Examples 2 and 3

fungicidal activity checked.

Reception 2

Mixture consisting of: 70 parts of an α, ω-Dihydroxypolydimethylsiloxans with a viscosity of 500OmPa. s., 30 parts of a dimethylpolysiloxane having a viscosity of 1,000 mPa blocked at the outer ends with trimethylsiloxy groups.

s., 170 parts of a filler consisting of a whiting with a grain spectrum of 80% within 1 to 10μιτι, 0.01 to 1 parts of fungicidally active additive, (Mbmc) and 7 parts of methyltriacetoxysilane as crosslinking component.

Recipe 3

Mixture consisting of: 100 parts of an α, ω-Di hydroxy polydimethylsiloxane with a viscosity of 10000OmPa. s.,

10 parts highly dispersed fumed silica having a specific surface area of about 200 m ² / g, 0.01 to 1 parts of a

fungicidally active additive (Mbmc) and 6 parts IViethyltriazetoxysiian as crosslinking component.

The effectiveness of the additive according to the invention under normal conditions (analogous to Example 2) and after intensive

Water treatment (analogous to Example 3) is shown in Tables 4 and 5 below.

Table 4 Inhibition of fungal growth in high and low filled SEP formulation Mbmc score notes

(%) AS 5th day 10th day

2 1.0 4.0 4.0 0.5 4.0 4.0 0.1 4.0 4.0 0.01 4.0 4.0 3 1.0 4.0 4.0 0.5 4.0 4.0 0.1 4.0 4.0 0.01 4.0 4.0

Table 5 Test of fungicidal long-term effect under water contamination Recipe Mbmc Boniturnoten

(%) AS 10days

H ₂ O treatment.

0,5 0,5

4.0 4.0

30 days H ₂ O treatment.

90 days H ₂ O treatment.

4.0 4.0

Claims (2)

Claim: 1. Fungicide-equipped cold-crosslinking silicone rubber one-component pastes containing conventional admixtures such as fillers in amounts of 10-200 parts, crosslinkers, catalysts, etc., characterized in that they contain as active ingredient methylene-bismethyl-cyanimidodithiocarbonat). 2. Cold-crosslinking silicone rubber one-component pastes according to item 1, characterized in that they contain methylenebis (methyl-cyanimidodithiocarbonat) in a concentration of 0.01-5%, in particular 0.1-1%.