Title of Invention

A PROCESS FOR THE PREPARATION OF IMPROVED SURFACE COATING FROM BHILAWANUT SHELL LIQUID; USEFUL FOR THE PROTECTION OF BAMBOO SURFACES.

Abstract The present invention provides a process for the preparation of improved surface coating from bhilawanut shell liquid useful for the protection of bamboo surfaces, which comprises reacting under reflux at a temperature in the range of 80 to 90°C for a period in the range of one to one and half hours the ingredients comprising of Bhilwanut shell Liquid 20 to 40 parts by weight, Phenol 30 to 60 parts by wei, Formalin 35 to 70 parts by weight, Catalyst Na OH 2.5 to 5 parts by weight, Water 5 to 10 parts by weight and adding 5-6% of Cupric chloride to the refluxed composition to get the said surface coating of air drying property.
Full Text The present invention relates to the preparation of improved surface coating from Bhilawanut Shell Liquid(BSL) useful for the protection of bamboo surfaces. This invention will lead to fruitful utilisation of plant based waste material BSL for the development of surface coatings with improved properties.
Bamboo, because of excellent mechanical properties is an ideal timber substitute for many structural applications. Bamboo is having good mechanical properties but it has poor durability. It is highly affected by moisture penetration and deteriorates very fastly. When bamboo is exposed to out door condition especially when it is in contact with ground it is subjected to number of deteriorating influence including decay due to micro organisms, fungi and degradation due to UV radiation of Sun light and it has poor resistance to corrosive atmosphere, which ultimately degrade bamboo and increase the cost due to frequent replacement while being used as a structural component. The protection of bamboo surface by BSL based coatings would help in saving the replacement cost.
References may be made to Goldstein I.S. 1973, Degradation and protection of wood In: Nicholas DD(ed.) 1973, wood deterioration and its prevention by preservative treatments, Vol.1 : degradation and protection of wood , Syracuse University press, New York. PP 307-339, wherein coating materials like Phosphate, Ammonium Sulphate, borax and Zinc chloride have been used as protective coatings for cellulosic materials. The drawbacks of these coatings materials are lechability and poor resistance to corrosive atmosphere. They are not suitable for the structural purpose bamboo.
The available information on the chemistry of Bhilawanut shell Liquid (BSL) shows that it is a rich source of bhilawanol (C21 H32 O2) which is phenolic in nature and contains unsaturated side chain in meta position. The BSL also contains a small quantity of mono hydroxy phenol (Semicarpal) and a mixture of hydrocarbons. BSL is similar to

Cashewnut Shell Liquid (CNSL) in its chemical properties as both contains substituted phenols namely bhilawanol and cardanol respectively.
Reference may be made to Indian patent specification number 13734 wherein condensation of CNSL is carried out with formalin and hexamine and no efforts have been made to substitute CNSL by BSL in the formulations. Reference may be made to patent specification number 28003 wherein BSL is used for consideration with formalin and hexamine. The drawbacks are the products require further heat curing at 80° - 200 ° C under pressure to obtain a hard compact body and they are stoving type. In conventional type coatings the consideration of BSL is carried out with formalin in the presence of aqueous solution of hexamine where the phenolic ingredient is wholly BSL. The product thus obtained are heat hardenable and require stoving and they are suitable for metallic surfaces and not for the cellulosic surface like bamboo and none of them are air drying.
Reference may be made to V. Sorna Gowri and Mohini Saxena., Ind., J., Chem., Tech., 1997, 228, 424 wherein CNSL was used to prepare CNSL - phenol formaldehyde and CNSL - styrene coatings and the drawbacks are, the coating are having poor resistance to acid medium and have poor mechanical film properties. The following table gives the mechanical film properties of CNSL based coatings.
Mechanical Film Properties of Coatings based on CNSL

(Table Removed)
The main object of the present invention is to provide a process for the preparation of improved surface coating from Bhilawanut Shell liquid(BSL) useful for the protection of
bamboo surfaces.
Another object of the present invention is to develop surface coatings from BSL utilising to advantage its long unsaturated side chain which obviates the drawbacks as detailed above.
Yet another object of the present invention is to obtain surface coatings suitable for the protection of bamboo surface from corrosive environments.
Accordingly the present invention provides a process for the preparation of improved surface coating from Bhilawanut Shell Liquid, useful for the protection of bamboo surfaces, which comprises reacting under reflux at a temperature in the range of 8UU C to 90° C. for a period of one to one and half hours ,
Accordingly, present invention provides a process for the preparation of improved surface coating from bhilawanut shell liquid useful for the protection of bamboo surfaces, which comprises
a) reacting under reflux at a temperature in the range of 80 to 90°C for a period in the
range of one to one and half hours the following ingredients,
Bhilwanut shell Liquid 20 to 40 parts by weight
Phenol 30 to 60 parts by weight
Formalin 35 to 70 parts by weight
Catalyst Na OH 2.5 to 5 parts by weight
Water 5 to 10 parts by weight;
b) adding 5-6% of Cupric chloride to the refluxed composition as obtained in step a)
to get the said surface coating of air drying property.
In an embodiment of the present invention the formalin used is of a concentration in the range of 37 to 39%
In an another embodiment of the present invention 5-6% of the curing agent Cupric chloride is incorporated in the improved coating to effect air drying property.

Fig.l of the drawing accompanying this specification represents the reaction mechanism for the preparation of the improved coating of the present invention.
The present invention provides a process for the preparation of new surface coatings from Bhilawanut shell Liquid (BSL) for the protection of bamboo surfaces which essentially consists of the preparation of BSL - phenol - formaldehyde coating( V) from BSL(II), phenol(I), formalin(III) and caustic soda(IV) which are in the range of BSL 20-40; Phenol ,30-60; formalin (37%) 35-70; catalyst 2.5- 5; water 5-10 parts by weight and allowed to react under reflux at a temperature range of 80° to 90 ° C and the coatings are air dried after the addition of curing agent Cu Cl 2
The coating prepared by the process of the present invention is useful for the protection of bamboo surfaces. The bamboo specimen may be prepared by splitting the culm in to two half horizontally and cut in to the size of 170 X 50 mm. These specimens may be dried at temperature of 103° ± 2° C for one hour. After drying the surfaces may be roughened with emery paper. A selective coating of approximate coating thickness 50 |a may be applied by brush and air dried. The specimen may be coated again and air dried.
In conventional type coatings the consideration of BSL was carried out with formalin in the presence of aqueous solution of hexamine where the phenolic ingredient is wholly BSL and the product obtained are heat hardenable and require stoving and they are suitable only for the metallic surfaces. None of them are air drying. The coatings prepared by the process of the present invention involve the partial replacement of BSL by phenol and the coatings is prepared without hexmine and the coating is air dried by adding curing agent. The coating of the present invention are having good mechanical film properties, durability and resistant to acids and they are converted to cross linked structures at atmospheric temperature.

The following example is given by way illustration of the present invention and therefore should not be construed to limit the scope of the present invention.
Example -1
The BSL - phenol - formaldehyde coating formation is carried out in a round bottom flask and the total required quantity of phenol, formalin are taken together and caustic soda dissolved in water and added to the reactants in the round bottom flask and reacted under reflux at a temperature of 85°C for one hour. The ingredients of the composition are as follows :
Reactants Parts by weight
BSL 40
Phenol 60
Formalin (37%) 70
Sodium Hydroxide 05
Water 10
To the coating so obtained 5% by weight Cucl2 is added. The resultant coating is air drying.

The BSL - phenol -formaldehyde coatings in this example has non-volatile matter 86%, Viscosity 58 centiposies at 30° C and pH value of 8.74, Drying time 50 minutes and specific gravity 1.12. The BSL -phenol-formaldehyde coating has good resistant to acidic medium. The coating passed both direct and indirect impact testing when subjected to 1 Kg. weight from 70 cm. The scratch hardness value is 1.5 Kg. and the thickness of the coating id 30 µ.
The main advantages of the present invention are
1. Use of cheap locally available, indigenous plant based waste materials BSL for
making coating compositions.
2. Coatings based on BSL are having good mechanical film properties.
3. Air drying coating material which are curable at atmospheric temperature.
4. Protection of bamboo surfaces from corrosive environments.
5. Coating imparts resistance to chemical attack while being applied as protective
coatings on bamboo.



We Claim:
A process for the preparation of improved surface coating not def from Bhilawanut shell Liquid useful for the protection of bamboo surfaces, which comprises:
a) reacting under reflux at a temperature in the range of 80 to 90°C for a period in the
range of one to one and half hours the following ingredients,
Bhilwanut shell Liquid 20 to 40 parts by weight
Phenol 30 to 60 parts by weight
Formalin 35 to 70 parts by weight
Catalyst Na OH 2.5 to 5 Parts by weight
Water 5 to 10 parts by weight;
b) adding 5-6% of Cupric chloride define to the refluxed composition as obtained in step a)
to get the said surface coating of air drying property.
A process as claimed in claim 1, wherein the formalin used is of a concentration in the range of 37 to 39%.
A process for the preparation of improved surface coating from Bhilawanut Shell Liquid useful for the protection of bamboo surfaces, substantially as herein described with reference to the example accompanying this specification.


Documents:

2382-del-1998-abstract.pdf

2382-del-1998-claims.pdf

2382-del-1998-correspondence-others.pdf

2382-del-1998-correspondence-po.pdf

2382-del-1998-description (complete).pdf

2382-del-1998-drawings.pdf

2382-del-1998-form-1.pdf

2382-del-1998-form-19.pdf

2382-del-1998-form-2.pdf


Patent Number 215739
Indian Patent Application Number 2382/DEL/1998
PG Journal Number 12/2008
Publication Date 21-Mar-2008
Grant Date 03-Mar-2008
Date of Filing 13-Aug-1998
Name of Patentee COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH
Applicant Address RAFI MARG, NEW DELHI-110001, INDIA.
Inventors:
# Inventor's Name Inventor's Address
1 MOHINI SAXENA REGIONAL RESEARCH LABORATORY (CSIR), HOSHANGABAD ROAD, BHOPAL-462026
2 SORNA GOWRI REGIONAL RESEARCH LABORATORY (CSIR), HOSHANGABAD ROAD, BHOPAL-462026
PCT International Classification Number C09D
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA