FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
MODIFIED FIBER-CEMENT COMPOSITION
RELIANCE INDUSTRIES LIMITED
an Indian Company
of 3rd Floor, Maker Chamber-IV
222, Nariman Point, Mumbai-400021,
Maharashtra, India.
Inventors:
1. GAJELLICHANDRAMOULIGANGARAM
2. KELKAR ANIL KRISHNA
3. ARORA ARUN
4. KRISHNAMURTHY GURUDATT
5. NIKAM SURESH
6. BHANGALE VIKAS
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

FIELD OF THE DISCLOSURE
The present disclosure relates to a modified fiber-cement composition. More particularly, the present disclosure relates to a modified fiber-cement composition for use as construction material.
BACKGROUND
Cement has been conventionally used as construction material for making articles such as slabs, columns, plinths and roofing sheets. Over the years, different substances have been coupled with cement to improve properties such as durability, load bearing and abrasion resistance.
Asbestos has been popularly used along with cement in the manufacture of roofing sheets. US 3985610 discloses a product comprising asbestos, cement, inorganic fillers accompanied by a 60% asphalt-water emulsion that may have diversified uses for construction purposes. US 2335208 discloses corrugated sheets made from asbestos and cement that are largely used for applications such as manufacture of roofing material. US 4184906 describes slabs prepared from asbestos-cement that may have additional layers such as metal foils for creating fluted and other ornamental effects that may be used at construction sites.
Mining and use of asbestos, however, is being banned in major parts of the world today due to the health risks associated with its use. Diffuse pleural thickening, lung cancer, cancer of the larynx, ovarian cancer, mesothelioma and asbestosis are some of the physiological manifestations caused by prolonged inhalation of asbestos fibers. Therefore, organizations such as the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and their Disposal, National Occupational Health and Safety Commission (NOHSC), British Government's Health and Safety Executive (HSE) and the Supreme Court of India have instituted a ban on the use of asbestos, whole or in part.
Efforts are, therefore, being directed towards developing compositions that contain less amounts of asbestos or different asbestos substituents. US 5637144 discloses use of water retention agents and metal clays, which when used in pre-determined

proportions, yield properties analogous to those of asbestos when used in cement-mortar compositions. US 4302370 discloses a composition comprising polyolefin fibers blended with asphalt cutback along with propylene carbonate as a coupling agent. The compositions of the afore-stated patents, however, contain significant quantities of asphalt that, in excess, causes various health hazards such as headache. skin rash, sensitization, fatigue, reduced appetite, throat and eye irritation, cough and skin cancer and poses significant threat to the environment.
The inventors of the present disclosure envisage a modified fiber-cement composition and a process for preparation thereof that precludes most of the disadvantages associated with the prior art compositions.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment is able to achieve, are discussed herein below.
It is an object of the present disclosure to provide a modified fiber-cement composition.
It is another object of the present disclosure to provide a modified fiber-cement composition which is economic and environment friendly.
It is yet another object of the present disclosure to provide a modified fiber-cement composition which is safe with regards to human use.
It is still another object of the present disclosure to provide a process for the preparation of the modified fiber-cement composition.
It is yet another object of the present disclosure to provide various articles prepared from the modified fiber-cement composition having desired flexural strength and load bearing strength.
It is still another object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.

Other objects and advantages of the present disclosure will be more apparent from the following description which is not intended to limit the scope of the present
disclosure.
SUMMARY
The present disclosure provides a modified fiber-cement composition comprising:
a. cement in an amount ranging between 40 % and 98 % of the total mass of
the composition;
b. asbestos fibers in an amount ranging between 1 % and 15 % of the total
mass of the composition;
c. polyester fibers in an amount ranging between 0.1 % and 1 % of the total
mass of the composition; and
d. optionally at least one additive,
wherein said polyester fibers are characterized by linear mass density ranging between 0.6 den and 2.0 den and length ranging between 1 mm and 20 mm; and
the ratio of said asbestos fibers and said polyester fibers ranges between 99: 1 and 70:30
Typically, the composition further comprises at least one ingredient selected from the group consisting of vegetable fiber, asphalt, silica fume, fly ash, rice husk ash. slate, sand, steel, microconcrete, clay, metal, galvanized metal and coated metal.
Typically, the polyester fiber is at least one selected from the group consisting of polyethylene terephthalate (PET), polyglycolic acid (PGA), polylactic acid (PLA), polycaprolactone (PCL), polyhydroxyalkanoate (PHA), polyhydroxybutyrate (PHB), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polytrimethylene napthalate (PTN), polybutylene naphthalate (PBN), polyethylene naphthalate (PEN) and vectran.

Typically, the polyester fiber is recycled polyester.
Typically, the additive is at least one selected from the group consisting of vehicles, binding agents, viscosity modifiers, fillers, foamers, rheology modifiers, preservatives, wetting and dispersing agents.
Typically, the dispersing agent is at least one selected from the group consisting of non-ionic polymeric surfactants, acrylic homopolymers, acrylic copolymers, fatty acids and salts of fatty acids in an amount ranging between 0.05 % and 2 % of the total mass of the composition.
Typically, the vehicle is water.
The present disclosure further provides an article prepared from the modified fiber-cement composition, wherein the article is selected from the group consisting of boards, plinths, slabs, columns, sheets and shafts.
The present disclosure still further provides a process for the preparation of an article composed of fibers and cement; said process comprising the following steps:
a, preparing a fiber-cement composition by admixing cement in an amount
ranging between 40 % and 98 % of the total mass of the composition,
asbestos fibers in an amount ranging between 1 % and 15 % of the total
mass of the composition, polyester fibers in an amount ranging between 0.1
% and 1.0 % of the total mass of the composition and optionally, at least
one additive, in at least one vehicle, in any order; and
b. forming an article from said fiber-cement composition by a process selected
from the group consisting of casting and the Hatschek method,
said article being selected from the group consisting of boards, plinths, slabs, columns, sheets and shafts.
Typically, said step of casting comprises the following steps:

i. casting said composition in at least one mold to obtain a molded composition; and
ii. drying said molded composition at a temperature ranging between 20 °C and 60 °C for a time period ranging between 20 hours and 30 hours to obtain the article.
Typically, the step of admixing further comprises incorporating at least one ingredient selected from the group consisting of vegetable fiber, asphalt, silica fume, fly ash, rice husk ash, slate, sand, steel, microconcrete, clay, metal, galvanized metal and coated metal.
Typically, the polyester fiber is at least one selected from the group consisting of polyethylene terephthalate (PET), polyglycolic acid (PGA), polylactic acid (PLA), polycaprolactone (PCL), polyhydroxyalkanoate (PHA), polyhydroxybutyrate (PHB), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polytrimethylene napthalate (PTN), polybutylene naphthalate (PBN), polyethylene naphthalate (PEN) and vectran.
Typically, the polyester fiber is recycled polyester.
Typically, the polyester fiber is characterized by linear mass density ranging between 0.6 den and 2.0 den and length ranging between 1 mm and 20 mm.
Typically, the additive is at least one selected from the group consisting of vehicles, binding agents, viscosity modifiers, fillers, foamers, rheology modifiers, preservatives, wetting and dispersing agents.
Typically, the dispersing agent is at least one selected from the group consisting of non-ionic polymeric surfactants, acrylic homopolymers, acrylic copolymers, fatty acids and salts of fatty acids in an amount ranging between 0.05% and 2.0%
Typically, the vehicle is water.

DETAILED DESCRIPTION
In accordance with one aspect of the present disclosure, there is provided a modified fiber-cement composition that consists of cement, asbestos fibers, polyester fibers and optionally, at least one additive. Generally, cement is present in an amount ranging between 40 % and 9% % of the total mass of the composition and asbestos fibers in an amount ranging between 1% and 15 % of the total mass of the composition.
The composition of the present disclosure includes polyester fibers as a substitute for asbestos fibers in order to reduce the health and environmental hazards associated with the use of the latter. The polyester fibers cannot directly bond with the cement whereas the asbestos fibers form a part of the cement without any fiber pull out. Therefore, this combination of ingredients of the present composition gives improved processing without affecting the strength. The polyester fibers are present in an amount ranging between 0.1 % and 1.0 % of the total mass of the composition. Further, the length of the polyester fibers of the present disclosure ranges between 1 mm and 20 mm and the linear mass density ranges between 0.6 den and 1.0 den. The characteristic small dimensions of the polyester fibers of the present disclosure facilitate their uniform dispersion throughout the composition as compared to the long fibers. The polyester fiber of the present disclosure is at least one selected from the group that includes but is not limited to polyethylene terephthalate (PET). polyglycolic acid (PGA), polylactic acid (PLA), polycaprolactone (PCL), polyhydroxyalkanoate (PHA), polyhydroxybutyrate (PHB), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polytrimethylene napthalate (PTN), polybutylene naphthalate (PBN), polyethylene naphthalate (PEN) and vectran. In one embodiment, the polyester fiber of the present disclosure is recycled polyester. The ratio of said asbestos fibers and said polyester fibers ranges between 99: 1 and 70:30.
The composition of the present disclosure optionally comprises at least one additive selected from the group consisting of vehicles, binding agents, viscosity modifiers, fillers, foamers, rheology modifiers, preservatives, wetting and dispersing agents. Dispersing agents are added to the composition so as to effectively disperse the

polyester fibers in the entire composition. In one embodiment, the dispersing agents are coated over the surface of the polyester to improve the dispersion. The dispersing agent is at least one selected from the group that includes but is not limited to non-ionic polymeric surfactants, acrylic homopolymers, acrylic copolymers, fatty acids and salts of fatty acids. The dispersing agent is present in an amount ranging between 0.05 % and 2.0 % of the total mass of the composition. The vehicle of the present disclosure is water.
The composition of the present disclosure further comprises at least one ingredient selected from the group that includes but is not limited to vegetable fiber, vegetable fibers in asphalt, silica fume, fly ash, rice husk ash, slate, sand, steel, microconcrete, clay, metal, galvanized metal and coated metal.
In accordance with another aspect of the present disclosure there is provided at least one article prepared from the modified fiber-cement composition of the present disclosure. Typically, the article is selected from the group that includes but is not limited to boards, plinths, slabs, columns, sheets and shafts. Despite the substitution of asbestos fibers by polyester fibers, the physical properties of the articles prepared from the composition of the present disclosure are at par with those of the articles prepared from the conventional asbestos fiber-cement compositions.
In accordance with yet another aspect of the present disclosure, there is provided a process for the preparation of an article composed of fibers and cement that consists of initially, admixing cement, asbestos fibers, polyester fibers and optionally at least one additive in water to obtain a composition. The resultant composition is in the form of dispersion.
The cement is taken in an amount ranging between 40 % and 98 % of the total mass of the composition, the asbestos fibers in an amount ranging between 01 % and 15 % of the total mass of the composition and the polyester fibers in an amount ranging between 0.1 % and 1 % of the total mass of the composition.
The length of the polyester fibers of the present disclosure ranges between 1 mm and 20 mm and the linear mass density ranges between 0.6 den and 2.0 den. Further, the

polyester fiber is at least one selected from the group that includes but is not limited to polyethylene terephthalate (PET), polyglycolic acid (PGA), polylactic acid (PLA), polycaprolactone (PCL), polyhydroxyalkanoate (PHA), polyhydroxybutyrate (PHB), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polytrimethylene napthalate (PTN), polybutylene naphthalate (PBN), polyethylene naphthalate (PEN) and vectran. In one embodiment, the polyester fiber of the present disclosure is recycled polyester.
The additive used in the process of the present disclosure is at least one selected from the group that includes but is not limited to vehicles, binding agents, viscosity modifiers, fillers, foamers, rheology modifiers, preservatives, wetting and dispersing agents. The dispersing agent is at least one selected from the group consisting of non-ionic polymeric surfactants, acrylic homopolymers, acrylic copolymers, fatty acids and salts of fatty acids and is included in an amount ranging between 0.05 % and 2.0 % of the total mass of the composition. The vehicle of the present disclosure is water.
The step of admixing optionally includes incorporating at least one ingredient selected from the group that includes but is not limited to vegetable fiber, asphalt, silica fume, fly ash, rice husk ash, slate, sand, steel, microconcrete, clay, metal, galvanized metal and coated metal.
The composition is processed further to obtain the article of the present disclosure. In one embodiment, the composition, in the form of a paste, is cast in at least one mold to obtain molded composition. The shape and dimensions of the mold depend upon the article to be prepared. The molded composition is then dried at a temperature ranging between 20 °C and 60 °C for a time period ranging between 20 hours and 30 hours to obtain the article. In another embodiment the composition is subjected to the Hatschek method to obtain the article of the present disclosure. In one exemplary embodiment, the Hatschek machine is employed to process the composition and yield the article of the present disclosure. The article is selected from the group that includes but is not limited to boards, plinths, slabs, columns, sheets and shafts.

The paste and the composition are the modified fiber-cement compositions of the present disclosure.
The present disclosure will now be discussed in the light of the following non-limiting embodiments;
Example 1: Flexural strength of slabs prepared from cement only, asbestos fiber-cement and the composition of the present disclosure (asbestos fiber-polyester fiber-cement)
A] Batch containing only cement:
84 g by weight cement was admixed in 33 ml water to obtain a cement water paste. The paste was caste in a mold and allowed to dry at 40 °C for 24 hours to obtain a slab. The slab had a length of 20 cm, width of 4 cm and thickness of 0.65 cm and a density of 1.35 g/cc. The solidified slab was then soaked in water for 24 hours and tested on a universal tensile testing machine (Instron) in a two point flexural strength mode under a span length of 100 mm and cross head speed of 1 mm/min. The breaking load was recorded by the instrument and expressed as flexural strength in MPa.
B] Batch containing cement and asbestos fibers:
98% by weight of cement and 2% by weight of asbestos fibers were dry mixed in a mixer to obtain a reaction mass 84 g. 33 ml of water was poured in the reaction mass followed by admixing to obtain a paste. The paste was caste in a mold and allowed to dry at 40 °C for 24 hours to obtain a slab. The slab had a length of 20 cm, width of 4 cm and thickness of 0.65 cm and a density of 1.35 g/cc. The solidified slab was then soaked in water for 24 hours and tested on a universal tensile testing machine (Instron) as mentioned in Batch A.
C] Batch containing cement, asbestos fibers and polyester fibers (the composition of
the present disclosure):

98% by weight of cement, 1.8% by weight of asbestos fibers and 0.2% by weight of polyester fibers (linear mass density- 1.5 den and cut length- 6 mm) were dry mixed in a mixer to obtain a reaction mass 84 g. 33 ml of water was poured in the reaction mass followed by admixing to obtain a paste. The paste was caste in a mold and allowed to dry at 40 °C for 24 hours to obtain a slab. The slab had a length of 20 cm, width of 4 cm and thickness of 0.65 cm and a density of T35 g/cc. The solidified slab was then soaked in water for 24 hours and tested on a universal tensile testing machine (Instron) as mentioned in Batch A.
Table 1. Breaking load of the articles prepared as per the process of Example 1.

Batch Details Flexural strength (MPa)
Batch A 2.9
Batch B 3.3
Batch C 3.4
It was observed that the flexura] stress of the slabs prepared from the cement-asbestos fiber-polyester fiber admixture (the composition of the present disclosure) is almost similar and even slightly higher than that of the slabs prepared from the cement-asbestos fiber admixture. Therefore, the replacement of asbestos with polyester fibers does not adversely affect load bearing strength.
Example 2: Process of preparation of the article of the present disclosure
9.6% by weight of the asbestos fibers, 37% fly ash and 53.4 % cement were admixed in water to prepare a dispersion having 10% solid content. To this dispersion, 0.1% polyester fibers having 6 mm length and 1.5 den linear density were admixed. The resultant dispersion was pumped into a Hatschek pilot machine and formed into corrugated sheets. The sheets were air cured in the open for 14 days and the 1 square meter sheets were tested for load bearing capacity by placing weights at the center of the sheets till they broke. During the trials improvement in process in terms of

machine speed and filterability was observed. The average load bearing strength of the sheets was found to be 525 kg.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE
Polyester fibers replace asbestos fibers in the composition of the present disclosure which in turn reduces the health and environmental hazards associated with the composition.
Further, inclusion of polyester fibers renders the composition cost effective along with increasing the production rate with minimum process variation.

Even further, physical properties of the composition such as flexural resistance are not adversely affected due to the replacement of asbestos fibers with polyester fibers.
Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression "at least" or "at least one" suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results.
The numerical values given for various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the invention and the claims unless there is a statement in the specification to the contrary.
While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Variations or modifications in the process or compound or formulation or combination of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this invention. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention.

We claim:
1. A modified fiber-cement composition comprising:
a. cement in an amount ranging between 40 % and 98 % of the total mass of
the composition;
b. asbestos fibers in an amount ranging between 1 % and 15 % of the total
mass of the composition;
c. polyester fibers in an amount ranging between 0.1 % and 1.0 % of the total
mass of the composition; and
d. optionally at least one additive,
wherein said polyester fibers are characterized by linear mass density ranging between 0.6 den and 2.0 den and length ranging between 1 mm and 20 mm; and
the ratio of said asbestos fibers and said polyester fibers ranges between 99: 1 and 70:30
2. The composition as claimed in claim 1 further comprises at least one ingredient selected from the group consisting of vegetable fiber, asphalt, silica fume, fly ash, rice husk ash, slate, sand, steel, microconcrete, clay, metal, galvanized metal and coated metal.
3. The composition as claimed in claim 1, wherein said polyester fiber is at least one selected from the group consisting of polyethylene terephthalate (PET), polyglycolic acid (PGA), polylactic acid (PLA), polycaprolactone (PCL), polyhydroxyalkanoate (PHA), polyhydroxybutyrate (PHB), polybutylene terephthalate (PBT),*polytrimethylene terephthalate (PTT), polytrimethylene napthalate (PTN), polybutylene naphthalate (PBN), polyethylene naphthalate (PEN) and vectran.

4. The composition as claimed in claim 1, wherein said polyester fiber is recycled polyester.
5. The composition as claimed in claim 1, wherein said additive is at least one selected from the group consisting of vehicles, binding agents, viscosity modifiers, fillers, foamers, rheology modifiers, preservatives, wetting and dispersing agents.
6. The composition as claimed in claim 5, wherein said dispersing agent is at least one selected from the group consisting of non-ionic polymeric surfactants, acrylic homopolymers, acrylic copolymers, fatty acids and salts of fatty acids in an amount ranging between 0.05% and 2.0 % of the total mass of the composition.
7. The composition as claimed in claim 5, wherein said vehicle is water.
8. An article prepared from the modified fiber-cement composition as claimed in claim 1, wherein said article is selected from the group consisting of boards, plinths, slabs, columns, sheets and shafts.
9. A process for the preparation of an article composed of fibers and cement; said process comprising the following steps:
a. preparing a fiber-cement composition by admixing cement in an amount
ranging between 40 % and 98 % of the total mass of the composition,
asbestos fibers in an amount ranging between 1 % and 15 % of the total
mass of the composition, polyester fibers in an amount ranging between 0.1
% and 1.0 % of the total mass of the composition and optionally, at least
one additive, in at least one vehicle, in any order; and
b. forming an article from said fiber-cement composition by a process selected
from the group consisting of casting and the Hatschek method,
said article being selected from the group consisting of boards, plinths, slabs, columns, sheets and shafts.

10. The process as claimed in claim 9, wherein said step of casting comprises the
following steps:
i. casting said composition in at least one mold to obtain a molded composition; and
ii. drying said molded composition at a temperature ranging between 20 °C and 60 °C for a time period ranging between 20 hours and 30 hours to obtain the article.
11. The process as claimed in claim 9, wherein said step of admixing further comprises incorporating at least one ingredient selected from the group consisting of vegetable fiber, asphalt, silica fume, fly ash, rice husk ash, slate, sand, steel, microconcrete, clay, metal, galvanized metal and coated metal.
12. The process as claimed in claim 9, wherein said polyester fiber is at least one selected from the group consisting of polyethylene terephthalate (PET), polyglycolic acid (PGA), polylactic acid (PLA), polycaprolactone (PCL), polyhydroxyalkanoate (PHA), polyhydroxybutyrate (PHB), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polytrimethylene napthalate (PTN), polybutylene naphthalate (PBN), polyethylene naphthalate (PEN) and vectran.
13.The process as claimed in claim 9, wherein said polyester fiber is recycled polyester.
14. The process as claimed in claim 9, wherein said polyester fiber is characterized by linear mass density ranging between 0.6 den and 2.0 den and length ranging between 1 mm and 20 mm.
15. The process as claimed in claim 9, wherein said additive is at least one selected from the group consisting of vehicles, binding agents, viscosity modifiers, fillers, foamers, rheology modifiers, preservatives, wetting and dispersing agents.

16. The process as claimed in claim 15, wherein said dispersing agent is at least one selected from the group consisting of non-ionic polymeric surfactants, acrylic homopolymers, acrylic copolymers, fatty acids and salts of fatty acids, in an amount ranging between 0.05 and 2.0%
17. The process as claimed in claim 15, wherein said vehicle is water.