|Title of Invention||
"AN ECO-FRIENDLY, ECONOMICAL AND NON-HAZARDOUS WOOD PRESERVATIVE".
|Abstract||An eco-friendly, economical and non-hazardous wood preservative comprising of copper sulphate, zinc chloride and borax in a fixed ratio of 15:2:9.|
|Full Text||FIELD OF INVENTION
This invention relates to an eco-friendly, economical and non-hazardous wood preservative.
BACKGROUND OF INVENTION
Wood is one of the most stable complex polymers of cellulose, lignin and hemicelluloses and because of its organic nature, it is prone to attack of certain organisms which can metabolize wood to simple sugar for deriving energy. The biological decay is caused by bacteria, fungi and insects. This decay is more common in nondurable plantation grown wood species, whereas, in durable wood species certain extractives are present which make it resistant to each type of biological decay.
Therefore, to protect products of nondurable species which are exposed to soil contact or exterior ground contact, chemical treatment is required. Remarkable results are obtained with different commercial products like copper chrome arsenate (CCA), creosote, chlorinated phenols, dithiocarbamates, quarternary ammonium salts etc. In recent years the health and environmental dangers associated with wood preservatives have attracted attention of environmental protection agency.
NEED OF WOOD PRESERVATION;
Wood becomes subject to degradation by a variety of natural causes when left untreated in many outdoor applications. Although some trees possess natural resistance to decay because of extractives and are categorized in durable wood category, many such timbers are in short supply. The current annual demand of industrial wood is around 40.2 million Cubic meters, which is going to increase manifolds in near future. It is not possible to meet the increasing wood demand from forests. Even import of wood and raising
plantations of fast growing wood species are unlikely to provide long term relief because of heavy drainage of foreign exchange and high inputs required in plantations. Thus, depleting supplies of durable woods have forced use of many non-durable wood species. Such non-durable or moderately durable wood species need extra protection when exposed to adverse environments. Such situations can easily be avoided by judicious use of chemical/preservatives. The degree of protection achieved depends on the preservative used and the level of penetration and retention of the chemicals. It is observed that wood preservatives applied at recommended retention levels impart remarkable protection to the wood. Judicious use of preservative in a moderately or non-durable wood greatly enhances the life of products thus saving the replacement and material costs. The annual replacement cost of treated wood in service is much less than that of wood without treatment.
Water borne preservatives are a major component of the wood treating industry because of their ease of application, low cost and the clean appearance of the wood after treatment. In the last decade, some basic compounds of conventional wood preservative, such as arsenic in tri-chromated copper arsenic (CCA), have been banned from the European and North American markets for most applications because of their high mammalian or environmental toxicity. In addition to the development of less toxic biocides, novel strategies for wood protection have been discussed for some decades. These strategies focus on ammonical copper quaternary compounds and other copper containing compounds associated with less toxic ions, are currently being used as wood preservatives.
Copper is one of the main ingredients of emerging wood preservatives because copper ion has a low toxicity in mammals, but has high toxicity against wood rotting fungi and insects. However, copper containing preservatives need thorough chemical investigation because of small copper losses that may occur from treated wood in service. Similarly
boron is an excellent wood preservative, it is useful for insect proofing, termite resistance, decay resistance, and combustion resistance for wood products. However, boron compound based preservatives have limited applications because of their leaching behavior. Wood treated by zinc borate showed good resistance to water leaching and exhibited good antifungal properties.
In view of this, world wide search for environmentally benign chemicals is being made to meet the preservative needs in the twenty first century. Studies have been conducted in which boric acid and boron compounds have been used as wood preservatives either in solution form or in vapour phase with methyl borate for their protective action. Studies have also been conducted on the combined effect of boron and copper on termite resistance. Literature on boric acid TIM-BOR, borax and zinc borate to control the surface growth of fungus on wood suggested that zinc acts as co-biocide and plays an important role to maintain higher concentration of borate on the wood surface. Work on insoluble meta-borates formed by impregnating wood with borax and metallic salts, exhibited good biological resistance but impregnation is difficult because of its low solubility in water. The formation of zinc, calcium and lead meta-borates by impregnating wood with a saturated borax solution and then diffusion with Zn2*' Ca2+ or Pb2+ solution at 10 and 40% metallic salt concentrations greatly enhanced the decay and termite resistance, with negligible weight loss in specimens.
DRAWBACKS ASSOCIATED WITH THE EXISTING STATE OF ART :
Water borne preservatives are a major component of the wood treating industry because of their ease of application, low cost and the clean appearance. Copper chrome arsenate was patented in 1938 and three forms i.e. types 'A' 'B' and 'C' were standardized in 1969. The other type of arsenicals preservative i.e. ammonical copper arsenate (ACA) was standardized in 1950. It was later on modified to ACZA i.e. ammonical copper zinc
arsenate in 1943. Another preservative i.e. CCB (Copper-chrome-boric composition) was developed by substituting costly arsenic by boron. The composition is effective at slightly higher doses. Another type of water-based preservative is Acid Copper Chromate (ACC), but it is more prone to leaching than the other water borne preservatives. In the same category of compounds, boron compound like Borax - boric acid offer some of the most effective and versatile preservative systems available today combining the properties of broad spectrum efficacy and low mammalian toxicity. The only draw back associated with the preservative is its limited use. All products treated with borax- boric acid is meant for interior uses as the preservative is susceptible to leaching. The draw back associated with CCA, a fixed type preservative, is its toxic nature. Both arsenic and chromium metals are carcinogenic. The toxic arsenate and chromium ions may leach from treated wood or be scattered into the atmosphere when the wood is destroyed by fire. Leaching and scattering result in environmental pollution. Therefore, all such formulations are under constant review due to environmental reasons and face the threat to be phased out in the future.
In view of this, worldwide search for environmentally benign chemicals is being made to meet the preservative needs in the twenty first century. Many such formulations containing boron and zinc are under development phases.
In recent years boron and zinc compounds have enjoyed increasing applications as wood preservative biocide. This has been due to their effectiveness against a wide range of wood destroying organisms and their relative low mammalian toxicity and limited impact on environment. Boric acid and boron compounds have been used as wood preservatives either in solution form or vapor phase with methyl borate due to their protective action. These compounds are being used in the form of rods, pellets, tablets etc. similarly use of copper ion as a preservative is also recommended because the copper ion has a low
toxicity in mammals, but a high toxicity against wood rotting fungi. But further research is required to fix copper ions in wood to check its teachability in soil. Recently metaborates were tested for leachability, decay and termite resistance. The insoluble borates with borax and metallic salts were tested in wood by double diffusion process with zinc, calcium and lead. Lead metaborate formed in the wood provided superb biological resistance against decay. Although lead metaborate was very efficacious, it again triggers a debate on environmental friendly molecules/salts.
The use of borates as wood preservatives has been reviewed extensively. Some researchers demonstrated that boric acid and sodium octaborate were effective against termites in laboratory bioassays but when applied in field against field population of termites it failed to prevent termite attack and damage of treated timber. It was concluded that failure may be due to excessive leaching of borate compounds from the treated timber in the field. Thus, a need was felt to test new wood preservatives like metaborates for outdoor as well as indoor applications before any recommendation is made.
Reports are available in which boric acid, sodium octaborate tetrahydrate, copper borate and sodium octaborate were tested and found toxic up to certain level in laboratory. Field results in Australia indicated that timber treated with borate compounds were susceptible to termite attack even at higher loadings.
Thus, in the present study zinc, boron and copper metal salts were reacted together to yield ZiBOC a water insoluble compound. In this invention, a double treatment was avoided by reacting all components in fixed ratio in vitro.
Over the past few decades there has been a substantial global awareness of the danger posed to wood treatment workers by most of the conventional proprietary wood preservatives, like copper-chrome-arsenic, pentachlorophenol (PCP) etc. The environmental degradation by the same is becoming a matter of major concern worldwide. Most of the conventional wood preservatives of synthetic nature are difficult to dispose off and are non-degradable.
Most of conventional wood preservatives contain toxic metals like arsenic and chromium and attempts are underway to phase out such preservatives. Although many studies have been carried out on metaborates the exact composition and rations of metal salts exhibiting high efficacy are not reported so far. Till date double treatments of Zinc and copper metaborates are reported but none of the study reports single treatment of fixed composition of metaborates of zinc, copper and boron.
OBJECTS OF THE INVENTION
The primary object of the present invention is to propose an eco-friendly, economical and non-hazardous wood preservative which is fixed type of wood preservative prepared by the interaction of copper sulphate, zinc chloride and borax.
Another object of the present invention is to propose an eco-friendly, economical and non-hazardous wood preservative which is quite efficient at very low concentration and comparable to copper chrome arsenic.
Further object of the present invention is to propose an eco-friendly, economical and non-hazardous wood preservative which is non-polluting and eco-friendly biocidal formulation.
Still another object of the present invention is to propose an eco-friendly, economical and non-hazardous wood preservative which overcomes disadvantages of the prior arts.
STATEMENT OF INVENTION
According to this invention there is provided an eco-friendly, economical and non-hazardous wood preservative comprising of copper sulphate, zinc chloride and borax in a fixed ratio of 15:2:9.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings and wherein:
Fig. 1 shows soil block bioassay-weight loss in Populus deltoids blocks.
Fig. 2 shows soil block bioassay -w eight loss in Pinus roxburghii blocks.
Fig. 3 shows plate -1 soil block bioassay.
Fig. 4 shows plate -2 change in shape and size of populus deltoids in soil block bioassay.
Fig. 5 shows termite mound test in field.
Fig. 6 shows stake test at different test yards.
Fig. 7 shows ZiBOC and CCA treated samples.
DETAIL DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS
The present invention provides a wood preservative comprising of atleast three components in the following proportion:
1. Zinc chloride (ZnCl2) = 2 parts
2. Borax (Na2B4O7.1OH2O) = 9 parts
3. Copper sulphate (CuSo4.5 H2=O) = 15 parts
The said preservative is having pH of 3.5-4.5.
All the said salts are taken in the above ratio and a 60% solution is made in Acetic Acid. The end product thus obtained is a paste and can be further diluted to different concentrations with the help of water as required.
Copper sulphate, zinc chloride and borax are used for the preparation in a ratio of 15:2:9. All are mixed together in a small amount of water and a 60% paste is made in acetic acid. This paste is diluted in water to get required concentrations. The pH of solution varies between 3.5 to 4.5. The formulation is amorphous and water insoluble and dissolved with the help of acetic acid. Fixation/leachability study of ZiBOC exhibited only 23.6, 13.1 and 12.1% teachability of copper, zinc and boron in chir and 53.5, 6.5 and 5% leachability of respective metals in poplar wood blocks. It was observed that maximum teachability of copper in poplar and zinc in poplar and chir took place in initial hours of study. 53.5% of copper and 6.5% of zinc of total salt can be leached out in poplar blocks after 168 hrs of leaching. It shows that 46.5% copper sulphate and 93.5% of zinc chloride was efficiently fixed in poplar wood. In chir samples a better fixation of copper salt could be achieved as only 23.6% copper and 13.1% of zinc could be leached out after 168 hrs of investigation. Results showed that about 77% of copper and 87% of zinc could be fixed in the chir wood. Similarly, 97% and 88% of boron fixation could be achieved in poplar and chir blocks.
Efficacy of ZiBOC in agar bioassays against white and brown rot fungus was evaluated at
different concentrations of ZiBOC. 0.01% concentration of ZiBOC retarded growth up to
60-65% of white and brown rot fungus i.e. Trametes versicolor L. ex Fries and
Oligoporus placentus Murr respectively. However 98% inhibition in growth was observed at 0.03% concentration of preservative. It is considered as threshold concentration while complete killing of fungus took place at 0.05% of ZiBOC. Soil block bioassays results revealed 54% weight loss in control samples of chir by brown rot fungus while at 0.05, 0.10, 0.20, 0.50 and 1.0% concentration of ZiBOC weight losses of 49, 48, 0.4, 0.2 and 0.13% respectively were observed in chir blocks. Whereas, white rot fungus caused 11.4% weight loss in control samples of chir while 4.5%, 1.5, 1.0,' 1.5%
weight losses could only be observed at different concentrations of the treated samples.
In poplar blocks 18% weight loss was observed in control samples against white rot fungus and at 0.50 and 1.0% concentration only 0.4 and 0.13% weight loss was observed in treated blocks. Brown rot caused 53% weight loss in control samples of poplar while
0.05, 0.10, 0.20, 0.50 and 1.0% concentration of preservative treated blocks exhibited 38.10, 9.90, 6.50, 1.60 and 1.60% weight losses respectively.
Results revealed that brown rot fungus cause more damage as compared to white rot. Study suggests efficient protection of both hard and soft wood at 0.20% concentration of preservative Termite mound bioassays conducted consequently for two years revealed complete damage of control samples by termites and a score of '5' was recorded. Samples treated at 0.5% concentration exhibited an average score of 1.02 while at 2% concentration score of 0.75 and 0.25 were recorded in Pinus roxburghii. In Populus deltoides the damage score on completion of the study were 1.33, 1.0 and 0.75 at 0.5, 1.0 and 2.0% concentrations of the preservative respectively. Control blocks were completely damaged exhibiting a 'score' of 5.0. Level of deterioration was ascertained by scoring or visual grading of samples (table 3 and Plate 3).
Thus, Pinus roxburghii i.e. softwood could be efficiently protected against fungus and termites at low concentrations of preservative while a higher concentration i.e. 2.0% was required to protect poplar wood against fungus and termites.
Laboratory studies are conducted under controlled conditions whereas in actual conditions protection is required against several fungi and termites attacking wood simultaneously. Such tests are done in a test yard or graveyard in ground contact in the open. For this, accelerated and stake tests have been used. Accelerated tests were conducted for 36 months. Specimens of size 38x6.25x153 mm were taken to compare the efficacy of various wood preservatives to get quicker data to augment the laboratory tests.
Accelerated field-test of chir and poplar veneers at 0.5, 1.0 and 2.0% concentration and retention of 3, 6 and 11 kg/m3 exhibited complete protection of pine wood after 36 months of observation at 6 and 11 kg/m3. Whereas, poplar wood exhibited heavy attack of fungus and termite at two lower retentions while at higher retention i.e. 11 kg/m3 moderate attack of fungus and termite was noticed. All control samples of chir and poplar
were completely damaged within 30 months of installation. It was observed that control samples of chir exhibited only 1.80 score in 19 months of installation while poplar started decaying within 9 months of installation and complete damage occurred within 15 months( Table4). Thus, chir exhibits more natural decay resistance compared to poplar. Another set of experiment with higher concentrations i.e. 2.5 and 3.0% of retention levels 13.0 and 16 kg/m3 exhibited complete protection of treated poplar and chir after 15 months of installation while chir control were attacked badly by both termite and fungus. Control samples of poplar were completely damaged (Table-5).
Stake test i.e. test with bigger size of samples i.e. 305mmx 38.1mm cross section treated with 2, 3 and 4% CCA and ZiBOC were taken for the study. Study is under progress at three locations. Results up to 15 months revealed that pine samples treated with CCA and ZiBOC are normal even after 15 months of observation while control exhibited slight termite attack at Dehra Dun centre. At Chakrata all samples are normal including controls. At Jodhpur all samples either of CCA and ZiBOC treated have been slightly attacked by termites, while controls samples were completely damaged within 6 months of installation. Samples treated with 6 and 8% of ZiBOC were again installed at Jodhpur to see the performance of preservative at the site which is heavily infested with termite.
Permanency test and Efficacy evaluation:
Evaluation of ZiBOC for fungi toxicity: Effectiveness of wood preservative against
fungi in terms of inhibition and killing concentration was evaluated by the following
Permanency test of ZiBOC: Permanency against leachability of preservative in any
wood is one of the important characteristics of an ideal wood preservative. Therefore,
leachability of ZiBOC was tested. Blocks of chir (Pinus roxburghii) and poplar (Populus
deltoides) of the size 19x19x19 mm3, free from any physical defects and decay were
prepared from sapwood of seasoned planks. Blocks were conditioned to a constant
weight, kept in a beaker under a weight to prevent floating and placed in a desiccator
connected to a manometer and suction pump of milipore grade. A partial vacuum was created in the desiccator for 30 minutes and a solution of 1% of ZiBOC was poured inside the beaker through the separating runnel, completely covering the blocks. The vacuum was released and blocks were allowed to remain for 30 minutes and were taken out and weighed immediately after wiping off any excess of preservative from the surface. Retention of preservative was calculated. The treated blocks were conditioned at room temperature and left for 21 days for fixation of preservative.
Six blocks impregnated with ZiBOC were placed in Erlenmeyer flask equipped with glass stopper, a magnetic stirrer and a plastic mesh to separate specimens. 300 ml of distilled water was poured, stirred at room temperature and leachates were removed at 6, 24, 48, 96 and 168 hours. Copper, zinc and boron were estimated in laboratory by standard procedures (IS: 2753-Part I- 1999). Leached blocks were conditioned again for constant weight, ground to dust and copper, zinc and boron metals were estimated
Agar test: A nutrient medium containing 20 g of agar and 20 g of malt extract in a litre of distilled water, autoclaved at 120°C for 20 minutes was taken for petri plates (10 cm) bioassays. Five concentrations of ZiBOC i.e. 0.01, 0.03, 0.05, 0.08 and 0.10% were studied against test fungus white and brown rot i.e. Trametes versicolor L. ex Fries and Oligoporus placentus Murr. respectively for 15 days in triplicate. Control sets without ZiBOC were also taken in triplicate. The petri plates containing the medium were inoculated with inoculums taken from an actively growing culture 14-16 days old of Oligoporus placentus Murr. and Trametes versicolor L. ex Fries .
The plates were incubated for 15 days at 25 ± 2°C temperature and relative humidity of 70±4% in the incubator (BOD of Narang make). The efficacy was evaluated. The cultures were examined and total inhibition or killing of each test fungus was noted.
Testing efficacy of ZiBOC on fungal decay of wood: The agar test is useful only as a preliminary test and for comparing the efficacy of compounds of similar nature, tests can be carried out with pure culture of the organisms, which normally attack the material in
Soil block method: Efficacy and performance evaluation of any preservative is done in blocks of sapwood of hard and soft woods. Blocks of wood are impregnated with different concentrations of preservatives and after a certain period are exposed to the action of one or more wood destroying fungi. The minimum amount of preservative that completely protects the impregnated blocks against decay by a given test fungus is defined as the "threshold retention" for the organism. The failure to protect wood from decay is determined by the amount of weight loss in the treated blocks. (The test carried out is detailed below:
The test blocks of softwood i.e. Pinus roxburghii and hardwood i.e. Populus deltoides of 19x19x19 mm3 with a 3.2 mm central hole, and feeder blocks from semul (Bombax ceiba) of 4x19x3 5mm along the length of grain were prepared. Test blocks were treated with 0.05, 0.10 and 0.20% concentrations of preservative as described earlier (Table-2, fig 1 and 2).
Preparation of soil culture bottle: 125 g. of air dried ground soil with pH between 5.0 to 7.0 was filled in screw-capped bottles. Thereafter, 40 ml of distilled water was added to it and two feeder blocks were placed on the surface of soil and sterilized for 30 minutes. The fungus Trametes versicolor L. ex Fries and Oligoporus placentus Murr. inoculums (10 mm square of 3 week old culture) placed on the edge of the feeder block and incubated at 25 ± 2°C and 70 ± 4 percent relative humidity for a period of 12 weeks.
After the required test period, blocks were removed, cleaned off mycelium, dried and conditioned to a constant weight and the percent weight loss was calculated (IS: 4833; 1968)( Plate land 2).
Testing of efficacy of preservative against termite in mound: Pinus roxburghii (Chir) and Populus deltoides (Poplar) samples of size 100x25x6 mm3, with a hole of 10 mm from the end were prepared, conditioned and treated with 0.5, 1.0 and 2.0% of ZiBOC. Untreated samples served as control. Six replicates of each absorption and retention, with a conditioned weight, were buried at different places inside a termite mound of Odentotermes obesus in a randomized fashion along with control in the month of May and samples were removed in November when activity of termites almost ceased due to fall in temperature. Samples were removed from mound, cleaned off mud and debris and evaluated visually. Same samples were reinstalled in the subsequent year in the month of May so as to have exposure to termites for two successive termite seasons. Decay/damage caused was noted by visual inspection of samples as done earlier (Table 3 and PlateS).
Accelerated test: Veneer samples (153x38x6.25 mm3) of chir and poplar, prepared from seasoned and defect free planks, were treated with 0.5, 1.0, 2.0, 2.5 and 3.0% concentrations of ZiBOC by the method described above i.e. 30 min vacuum and 30 minutes dipping. Different retention levels were achieved. Six replicates of each species, at each absorption, along with control (untreated), with conditioned weight were buried half below and half exposed above the ground in horizontal and vertical rows, 60 cms apart in a split plot design. Regular inspections were carried out every month in first year, quarterly in the second year and half yearly in the third year. Knife and sound test was carried out to determine the extent of decay or destruction due to fungus or termites or combination of these two (Table4 and 5).
Stake test: Defect free specimens of size 305x38.1x38.1 mm3 were made from sap wood of Pinus roxburghii and Populus deltoides defect free, and seasoned planks. Three concentrations of preservatives i.e. 2, 3 and 4% of ZiBOC and CCA were made. 12 replicates of each species and at each concentration along with 12 numbers of controls (untreated) specimens were taken for three test yards i.e. Dehra Dun, Chakrata and
Jodhpur; i.e. a total of 36 samples of ZiBOC treated, 36 samples of CCA treated and 12 samples of control of Pinus roxburghii as well as Populus deltoides were installed at each centre. Dehra Dun (30.19 N and 78.04 E) was chosen as it has combined infestation of fungus and termite. Similarly to see the effect of fungus only, Chakrata (30.42N, 77.5 IE) of cold climate was selected. Jodhpur (26.18 N, 73.04 E) having arid climate was selected as it has only heavy termite infestation in ground. Same numbers of samples were installed at each center (Table6, Plate4 and 5).
Treatment of stakes: Impregnation of wood under pressure is the most desirable and best method to get uniform and proper treatment under controlled conditions. All specimens were placed in a treatment cylinder and vacuum of 56 cm mercury was created and maintained for 30 minutes. A pressure of 4 kg/cm2 was created and samples were treated for 30 minutes. All samples were weighed immediately after wiping off extra preservative dripping from specimens and retention on dry weight basis was calculated. Samples were kept for 21 days for fixation of preservative. AH samples were buried half below and half exposed above the ground in horizontal and vertical rows 60cm apart at all three centers. Regular inspections were carried out quarterly in the first year. Further inspection will be carried out on half yearly basis in the second year and yearly in the subsequent years. Evaluation is done by the knife and sound process.
Application/use: Treatment of non-durable wood species with preservatives of eco-friendly nature to enhance life by 5-8 times.
ADVANTAGES OVER KNOWN ART ;
Copper, zinc and boron which are either categorized under essential trace metals or have very low mammalian toxicity used to develop present invention. The present composition is a fixed composition like 'CCA' and it had exhibited excellent results against termites and fungus which is considered to be attributable to the presence of metaborates containing effective components of copper, zinc and boron in a fixed ratio. Because of
fixed ratio it had also exhibited excellent permanence. Present formulation is non-toxic to human beings and toxic to wood decaying fungus and microbes. Further, it is effective at very low concentration and very easy to handle.
Tablel: Percent loss of dry salt of ZiBOC in leaching at different time interval during permanency test in Populm deltoides and Pinus roxburehii.
Table 2; Weight loss cost by white rot (TV) and brown rot (OP) in Soil block bioassay.
Table 3: Test results ofPinus roxbirehii and Povlus deltoides sample, treated with ZiBQC, in the termite mound after 1st and 2nd season.
Table4: A- Pinus roxburshu venner samples at Dehra Dun test yard at lower cone, of preservative.
Table4: B- Poyulus deltoides venner samples at Dehra Dun test yard at lower cone, of preservative.
Table5; A- Pinus roxburehii venner samples at Dehra Dun test yard at higher cone, of preservative- Date of installation ; 21.3.06
Table5: B- Populus deltoides venner samples at Dehra Dun test yard at higher cone, of preservative Date of installation : 21.3.06
TABLE-6- Pinus roxburehii stake test at Different centers;
A-Jodhpur Yard Date of installation 28.6.06
B-Pehradun Yard Date of installation 18.7.06
C-Chkrata Yard Date of installation 14.10.06
*Level of deterioration-SCORE
It is to be noted that the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims:-
1. An eco-friendly, economical and non-hazardous wood preservative comprising of copper sulphate, zinc chloride and borax in a fixed ratio of 15:2:9.
2. An eco-friendly, economical and non-hazardous wood preservative as claimed in claim 1, wherein a 60% solution is made in Acetic Acid.
3. An eco-friendly, economical and non-hazardous wood preservative as claimed in any of the preceding claims, wherein the resultant end product is in the form of paste, which can be further diluted to different concentrations in water according to the requirement.
|Indian Patent Application Number||264/DEL/2008|
|PG Journal Number||40/2013|
|Date of Filing||30-Jan-2008|
|Name of Patentee||FOREST RESEARCH INSTITUTE (INDIAN COUNCIL OF FORESTRY RESEARCH AND EDUCATION),|
|Applicant Address||P.O. NEW FOREST, DEHRADUN-248006, INDIA.|
|PCT International Classification Number||C09D113/02; C09D113/00|
|PCT International Application Number||N/A|
|PCT International Filing date|