FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
PROVISIONAL SPECIFICATION
(See section 10; rule 13)

1. Title of the invention.

AN ECO-FRIENDLY ALTERNATIVE TO PHENOL FORMALDEHYDE RESIN

2. Applicant(s)
(a) NAME :
(b) NATIONALITY
(c) ADDRESS:

PARAMESWARAN, Sitalakshmi
An Indian Citizen
7, Kalpakam, Plot 49/1, Chhedanagar, Chembur, Mumbai - 400 089
State of Maharashtra, India

(a) NAME:
(b) NATIONALITY
(c) ADDRESS:

SANKARAN Giridhar
An Indian Citizen
A-1/73, Shivai Society, Chhedanagar, Chembur, Mumbai - 400 089
State of Maharashtra, India

3. PREAMBLE TO THE DESCRIPTION
The following specification describes the invention

FIELD OF INVENTION
The present invention relate to eco friendly resins which may be used as substitute for phenolic resins. More particularly the present invention relates to resin comprising soy and CNSL in defined ratio.
BACKGROUND AND PRIOR ART
Soya based glues were very popular in the 20th century. Soy flour contains large amount of proteins. Its amino acids are very reactive. This reactive nature of soy flour enables it to form adhesives. These soy adhesives can bind wood, paper, etc. But, these adhesives had poor shelf life.
These adhesives were replaced by petroleum based resin in the later centuries.
Environmental concerns and human health issues regarding phenol formaldehyde had caused great interest in this project.
Due to scarcity and increase in the price of petroleum products, a need was felt to find a suitable eco-friendly alternative for PF. Soy based resins are again considered the best alternatives.
Cashew Nut Shell Liquid (CNSL) is one of the sources of naturally occurring, a better and cheaper source of unsaturated phenols. It is amber colored, viscous liquid, obtained from the shells of cashew nut by extraction. It is used in polymer based industries, paints, varnishes, laminating resins and as wood preservatives.
CNSL is a potential environment-friendly substitute for the more petroleum dependant phenol which is as of now the major and/or the sole cheaper source of phenol.


The reactive nature of amino acids of soya hydrolysate provides the ability to form thermoset networks with a suitable cross-linking agent through copolymerization. This allows the use of soy flour for preparation of novel adhesives / resins.
Soy resins offer low cost raw materials and environmental sustainable benefits and flexibility and hence it makes a promising choice for use.
Soy flour is a finely ground defatted meal obtained from soybeans. It contains large amount of proteins. 25-30% of its amino acids are very reactive. For adhesive formulation, it requires dissolving flour in Sodium Hydroxide solution. The resulting degraded soy protein solution or the isolated soy protein is the soy hydrolysate. Its pH is around 10 and it is flowable at room temperature.
Soy flour can be combined or co-reacted with phenyl formaldehyde and used as binder for plywood, particle board, strand board, paper, etc.
The major by-product of cashew nut is the liquid from the pericarp known as cashew nut shell liquid (CNSL). CNSL is one of the sources of naturally occurring phenols. CNSL is amber colored viscous oil obtained from the by-product shells of the cashew nut by extraction. It is often considered as the better and cheaper source of unsaturated phenols. CNSL has innumerable applications in polymer based materials.
The composition of the CNSL is approximately 50% cardanol and 30% anacardic acid (carbopenta-dica-dienyl-phenol), with the remainder being made up of other substances.


Characteristic Properties of CNSL Extracted

Properties Value
pH 5.79
Specific Gravity, g/cm3 0.95
Viscosity 58.9
Refractive Index 1.48
Total Dissolved Solid 1.53
Molecular Weight 5030.74
Physicochemical properties of the recovered phenol:

Property Polyphenol
Phenol Resorcinol
pH 6.7 2.57
Viscosity 56.89 301.2
Specific gravity (g/cm ) 0.91 1.1
Refractive Index 1.48 1.39
Thus there is need to provide alternative for phenols in formation of adhesives/resins with soy flour. The present inventors have found that use of soy and CNSL in defined ratio provide soy CNSL resin which has high binding capacity.
OBJECTIVES OF THE INVENTION
Thus an objective of the present invention is to provide an eco-friendly alternative to phenol formaldehyde resin and prepare soy based phenolic resin


A further objective is to provide to substitute CNSL for Phenol Formaldehyde in the formation of soy CNSL resin of high bonding property.
Another object is to investigate the bonding and binding properties of the soy-CNSL resin and to find out the mechanical properties of the pressed corrugated sheets and other materials
SUMMARY OF INVENTION:
Thus according to one aspect there is provided a soy- CNSL resin comprising soya flour and CNSL resin in the ratio of from 1:1 to 1:4
DETAILED DESCRIPTION OF INVENTION
Brief Description of The Drawings
Figure 1: Bar diagram showing water absorption properties.. Figure 2: Bar diagram showing Soy-Resin properties Figure 3: Bar diagram showing tensile strength
The preparation of soy CNSL resin is shown in the following Scheme 1

two pieces of sun mica, plywood, newspaper and brown paper are also stuck with the resin. The sheets are hard-pressed together using a Screw-Jack press.
It is observed when this resin was applied to sample pieces of corrugated sheet, plywood, sun mica, news paper, brown paper all the pieces stuck well, but the samples remained wet.
The result is depicted in the following table

Resin Corrugated Plywood Plywood + Newspaper Brown
Sheet Sun Mica Paper
Only Soy Stuck well. Stuck Stuck well. Stuck well. Stuck well.
Wet Sample well. Wet Sample Wet Sample Wet Sample Wet Sample
Example 2
CNSL resin and its application
a) Preparation of the resin
50 ml of CNSL is taken in a beaker. It is heated to 70°C in a water bath. The resulting solution is used to bind different materials.
b) Application of CNSL to various materials
One big corrugated sheet is taken and cut into 5 pieces of size 12x12 cm. The craft / brown paper spread over it. CNSL was applied uniformly over the sheet. Two pieces are stuck together. 5 pairs of sheets are stuck in this manner. Similarly few pieces of newspaper and brown paper are also stuck with the resin. The sheets are hard-pressed together using a Screw-Jack press.


It is observed that CNSL was applied to the sample materials, no binding took place and the materials looked very oily.
The result is depicted in the following table

Resin Corrugated Plywood Plywood + Newspaper Brown
Sheet Sun Mica Paper
Only CNSL Very Oily. ~ ~ Very Oily. No Very Oily.
No Binding Binding No Binding
Example No. 3
Preparation of Soy-CNSL resin (1 : 1)
a") Preparation of the resin
50 ml of 12% NaOH is taken ina beaker. 2 ml MEG(Mono Ethylene Glycol) is added, stirred well, heated it to 70°C in a water bath. 20 gm soy flour is added and stirred well till it became semi-liquid. To this mixture, 20 ml CNSL is then added and stirred well. Formaldehyde is also added and stirring continued. The resulting thick solution is the resin formed.
b) Application of the prepared resin to various materials
One big corrugated sheet is taken, cut into 5 pieces of size 12 x 12 cm.. The craft / brown paper is spread over it. The resin is applied uniformly over the sheet. Two pieces are stuck together. 5 pairs of sheets are stuck in this manner. Similarly two


pieces of sun mica, plywood, newspaper and brown paper were also stuck with the resin. The sheets are hard-pressed together using a Screw-Jack press.
It is observed that when this resin was applied to sample pieces of corrugated sheet, plywood, sun mica, news paper, brown paper, good binding was observed.
The result is depicted in the following table

Resin Corrugated Plywood Plywood + Newspaper Brown
Sheet Sun Mica Paper
Soy : CNSL Good Good Good Good Good
(1:1) Binding Binding. Binding. Binding Binding
Example No. 4
Preparation Of Soy-CNSL resin (1 : 2)
a) Preparation of the resin
50 ml of 12% NaOH it is taken in a beaker. 2 ml MEG is added to it and stirred well, heated it to 70°C in a water bath. 20 gm soy flour is added and stirred well till it becomes semi-liquid. To this mixture, 40 ml CNSL is then added and stirred well. Formaldehyde is also added and stirring continued. The resulting thick solution is the resin formed.
b) Application of the prepared resin to various materials


One big corrugated sheet is taken and cut into 5 pieces of size 12 x 12 cm. The craft / brown paper is spread over it. The resin is applied uniformly over the sheet. Two pieces are stuck together. 5 pairs of sheets are stuck in this manner. Similarly two pieces of sun mica, plywood, newspaper and brown paper are also stuck with the resin. The sheets were hard-pressed together using a Screw-Jack press.
It is observed that when this resin is applied to sample pieces of corrugated sheet, plywood, sun mica, news paper, brown paper, good binding takes place.
The result is depicted in the following table

Resin Corrugated Plywood Plywood + Newspaper Brown
Sheet Sun Mica Paper
Soy : CNSL Very Good. Very Very Good. Very Good. Very Good.
(1:2) Good.
Example 5
Preparation of Soy-CNSL resin (1 : 3)
a) Preparation of the resin
50 ml of 12% NaOH is taken in a beaker and 5 ml MEG is added. It is stirred well and, heated to 70°C in a water bath. 10 gm soy flour is added and stirred well till it becomes semi-liquid. To this mixture, 30 ml CNSL is then added and stirred well. Formaldehyde is also added and stirring continued. The resulting thick solution is the resin formed.


b") Application of the prepared resin to various materials
One big corrugated sheet is cut into 5 pieces of size 12x12 cm. The craft / brown paper is spread over it. The resin is applied uniformly over the sheet. Two pieces are stuck together. 5 pairs of sheets are stuck in this manner. Similarly two pieces of sun mica, plywood, newspaper and brown paper were also stuck with the resin. The sheets are hard-pressed together using a Screw-Jack press.
It is observed that_when this resin is applied to sample pieces of corrugated sheet, plywood, sun mica, news paper, brown paper, excellent binding occurs in all materials especially in corrugated sheets
The result is depicted in the below table

Resin Corrugated Sheet Plywood Plywood + Sun Mica Newspaper Brown Paper
Soy : CNSL (1:3) Excellent Binding. VeryGoodBinding. Very Good Binding. Very Good Binding. Very Good Binding.
Example 6
Preparation of Soy-CNSL resin (1 : 4)
a) Preparation of the resin
50 ml of 12% NaOH it is taken in a beaker, 5 ml MEG is added, stirred well and heated it to 70°C in a water bath. 10 gm soy flour is added and stirred well till it becomes semi-liquid. To this mixture, 40 ml CNSL is then added and stirred well.


Formaldehyde is also added and stirring continued. The resulting thick solution is the resin formed.
b") Application of the prepared resin to various materials
One big corrugated sheet is cut into 5 pieces of size 12x12 cm. The craft / brown paper is spread over it. The resin was applied uniformly over the sheet. Two pieces are stuck together. 5 pairs of sheets are stuck in this manner. Similarly two pieces of sun mica, plywood, newspaper and brown paper are also stuck with the resin. The sheets are hard-pressed together using a Screw-Jack press.
It is found that when this resin is applied to sample pieces of corrugated sheet, plywood, sun mica, news paper, brown paper, good binding occurred in corrugated sheet, newspaper and brown paper.
The result is shown in below table:

Resin Corrugated Plywood Plywood + Newspaper Brown
Sheet Sun Mica Paper
Soy : CNSL Very Good. - - Good. Good.
(1:4)
The data from the above examples are then analysed for the effect of the different combinations to show their effects on various properties like water absorption, tensile strength and the like.
The binding properties of the resin with soy and CNSL taken alone or in various combinations are shown in the table below:


Materials Example 1 Example 2 Example 3 Example 4 Example 5 Example 6
Used
Only Only Soy : CNSL Ratio
Soy CNSL
1 : 1 1 :2 1 :3 1 :4
Corrugated Stuck well. Very Oily. Good Very Good. Excellent Very Good.
sheet Less Pot No Binding. Pot Life Binding. Pot Life
Life. Wet Sample Binding Pot Life extended Extended Pot Life Extended Extended
Plywood Stuck well. ~ Good Very Good. Very good
Less Pot Binding. Pot Life Binding.
Life. Wet Sample Pot Life extended Extended Pot Life Extended
Plywood + Stuck well. ~ Good Very Good. Very good
Sun Mica Less Pot Binding. Pot Life Binding.
Life. Wet Sample Pot Life extended Extended Pot Life Extended
Newspaper Stuck well. Very oily. Good Very Good. Very good Good. Pot
Less Pot No Binding. Pot Life Binding. Life
Life. Wet Sample Binding Pot Life extended Extended Pot Life Extended Extended

Brown paper Stuck well. Very oily. Good Very Good. Very good Good. Pot
Less Pol No Binding. Pot Life Binding. Life
Life. Wet Binding Pot Life Extended Pot Life Extended
Sample extended Extended
Thus it is evident that the resin combination with soy to CNSL in ratio of 1:3 provides the best result in terms of binding and extended pot life.
WATER ABSORPTION TEST
The resin with different proportion of soy to resin is tested for water absorption
properties. The result is depicted in the following table and figure 1.
The resin is weighed and submerged in water at 27°C + 2°C for a period of 24 hours.
The specimen is dried and weighed. The percentage of increasing weight is the water
absorption.

Resin Weight before Test (g) Weight after Test (g) % water Absorbed
Control Soya 3 8.2 63.41
1:1 1.2 1.8 50
1:2 1.6 1.9 18.75
1:3 1.4 1.6 16.7
SOY RESIN PROPERTIES
The resin with different proportion of soy to resin is tested for properties like pH. The result is depicted in the following table and figure 2.


Resin pH
Control Soya 10.0
Control CNSL 6.0
1:1 3.9
1:2 4.1
1:3 5
1:4 5.4
TENSILE STRENGTH
The resin is tested for properties like tensile strength. The result is depicted in the following table and figure 3

Tensile Strength (mPa) Elongation at Break (%)
Control (without resin) 5.4 2.8
With Soy-CNSL resin 6.2 2.2
COST FACTOR
The cost of the resin of the present invention is compared with those known in the art and the present resin is found to be cost effective as shown in the following tables.

Materials Cost (Rs.)

Soya Seed (300 gm) 6
Grinding 1
Cashew Nut Shell Liquid (750 ml) 13
Other Chemicals (Sodium Hydroxide, Mono Ethylene Glycol, Formaldehyde) 8


Cost for Soya - CNSL Resin (~ 1 Kg)

28

COMPARATIVE COST OF OTHER RESINS

Commercial Resins Amount(in Rs.) per Kg
Fevicol 125
Urea Formaldehyde 70
Phenol Formaldehyde 75
From the above results it is seen that the resins prepared were applied in sample pieces of corrugated sheets, plywood, plywood + sun mica, newspaper and brown paper, hard-pressed together using a Screw-Jack press and tested for their binding properties.
The said results is summarized as under
The resin prepared with soya flour alone when applied to the above materials it stuck well in all the pieces, but the samples remained wet. The resin had a very short shelf life.
When CNSL alone was applied to the materials, no binding took place and the materials looked very oily.


Resin prepared with 1:1 ratio of soy : CNSL, when applied to the materials, , good binding was observed in all the samples. Extended pot-life was observed with the resin sample.
The soy : CNSL resin prepared with 1:2 ratio showed very good binding effect in all the materials tested. The sample has an extended pot-life.
The resin prepared with 1:3 ratio of soy : CNSL had excellent binding properties especially in corrugated sheets as compared to other resin samples and extended pot life was also observed.
The resin sample containing 1:4 ratio of Soya : CNSL had good binding properties when applied in corrugated sheets, newspaper and brown paper. The pot life of this resin is also good.
All the resin samples prepared with soy and CNSL showed good binding properties especially the one with 1:3 ratio.
The sample bound with soy CNSL resin showed an increase in tensile strength but a reduction in the elongation at break %.
Slight changes in pH (gradual increase) were observed in the different resin samples prepared by increasing the proportion of CNSL
By increasing the proportion of CNSL the water absorption decreases.
Thus all the Soya - CNSL resin samples showed good binding property and extended pot life in all the materials tested and the 1:3 ratio Soy - CNSL resin sample showed EXCELLENT binding property in all the materials. Further the Soy - CNSL resin sample offers cost savings of more than 50% as compared to other commercially available adhesives. The soy resins offer low cost raw materials and


environmental sustainable benefits and flexibility and hence it makes a promising choice for use in furniture, paint and other industries. These new soy adhesives promise both improved performance and economics to the wood, paper products and agricultural composite industries.