Title of Invention

METHOD FOR PRODUCING BARS OF VARIED FORMULATIONS

Abstract

A method for producing bars of varied formulations having a water resistant coat applied at least on a surface portion thereof, said water resistant coat comprising : i. subjecting the selected surface portion of a preformed bar of desired shape /configuration and formulation to step of polymeric coating using a polymeric coat material and ii. obtaining desired water barrier/resistant coated bars therefrom

Full Text

FORM -2 THE PATENTS ACT, 1970 (39 of 1970) COMPLETE SPECIFICATION (See Section 10) METHOD FOR PRODUCING BARS OF VARIED FORMULATIONS HINDUSTAN LEVER LIMITED, a company incorporated under the Indian Companies Act, 1913 and having its registered office at Hindustan Lever House, 165/166, Backbay Reclamation, Mumbai -400 020, Maharashtra, India The following specification particularly describes the nature of the invention and the manner in which it is to be performed. Original 955/MUM/2002 GRANTED 01/11/2003 FIELD OF THE INVENTION The present invention relates to method of providing water-resistant coated bars/shaped solid such as detergent/cleaning composition in bar form usually used for cleaning hard surfaces/fabric/personal cleansing and to a system for carrying out such method to produce the said bar with desired selective surface coating. Importantly, following the above method and using the system of the invention, it is possible to provide water barrier coat on bar / shaped solid forms of detergent/cleansing formulations adapted to serve as a sacrificial water resistant coating such that only -during application of the bar the external coat gets abraded or wears-off while during its storage and non-application so long as the coated surface is not subject to any abrasive action the water barrier coat remains to favor avoiding physical disintegration/sogging of the bar in contact with water. BACKGROUND ART Detergents/cleansing bars are usually of varied compositions depending upon the end use/application desired. While various forms of such bars are made available to the art for diverse end uses, attractions and applications considering that. such detergent/cleansing bars/forms are always required to be applied/perform along with water or in the presence of the water it is found that after initial application of such bar on fabric or hard surfaces personal cleansing as the case may be, the bar when stored/kept open for subsequent use upon contact with water and/or due to spilled water in its place of storage for subsequent uses and/or due to atmospheric moisture content is found to lead to problems of physical integrity/sogginess of the bar. Importantly, such sogginess and loss of desired physical form of the bar pose problems of its holding for subsequent use/application. Moreover, the too soft and soggy physical character of the bars contribute towards extensive loss of the formulation thereby making its use a cost extensive affair since lot of the composition is lost due to unregulated release onto the fabric the substrate to be cleaned. Thus, the coverage achieved by a desired quantity of the bar formulation is reduced to a substantial extent leading to its use being extremely cost extensive and problematic. Additionally, the soggy character of the bar make it so unattractive and difficult to handle that the consumer at times even have to throw away the remainder of such soft bars as it is found not suitable for use. Moreover even if one tries to use the soggy and soft bar, the contents stick to the fingers and to the hands during application/use and this causes additional problem to the consumer. To avoid such structural problems of repeated use/application of the bar forms of formulations for fabric/hard surfaces/personal cleansing application, in our co-pending application No. 417/MUM/2001 there is disclosed a shaped detergent composition comprising: i. 0.5-60% detergent active; ii. 0-90% inorganic particulate; and iii. other conventional ingredients, wherein external surfaces of such shaped detergent article are covered with one or more materials that are substantially water insoluble, said materials having melting point higher than 30o C andvbeing adherent to the external surface and capable of being abraded during use. In our another co-pending application 1131/MUM/2001 there is provided a shaped detergent composition comprising: i. 0.5-95% by wt. detergent active; ii. 0-90% by wt. inorganic particulate; and iii. other conventional ingredients, wherein the external surface of said shaped detergent article comprise at least one selective polymer film generated using a radiation curable composition. While in our above co-pending applications, there is already proposed the coating of bars to avoid problems of loss of physical characteristics leading to soft and soggy bars due to contact with water, need has been felt to develop method and system for industrial production of the coated bars to make such products available for extensive and wide use to effectively take care of the problems of loss of shape and physical form of bars in contact with water. OBJECTS OF THE INVENTION It is thus the basic objective of the present invention to provide for a method and system for producing coated bars such as detergent/cleansing compositions in bar form, which would avoid the aforediscussed problems of loss of physical structure and integrity of such bars when in contact with water. Another object of the present invention is directed to provide for a method and system preferably UV/EB curable for producing coated bars for detergent / personal cleansing / hard surface cleaning and the like which would achieve the desired maintenance of physical integrity of the bar by way of a selective simple and cost effective sacrificial water resistant coating to take care of aforediscussed loss of physical characteristics/constitution of such bars in contact with water. Another object of the present invention is to provide for method and system preferably UV/EB curable for producing coated bar which would provide for an aesthetic and attractive surface finish of conventional detergent/personal care/hard surface cleansing formulations in bar form. Yet another object of the present invention is provide for UV curable method and system for producing coated bars for detergent / hard surface / personal cleansing which would be storage stable as far as maintaining its physical integrity in contact with water is concerned and thus enable its extensive, extended and effective multiple use with controlled release of active formulation thereby improving the efficiency of cleaning and at the same time avoid wastage of expensive detergent/cleansing materials. Yet further object of the present invention is directed to a simple and cost effective UV curable method and system for manufacturing coated bars for detergent / hard surface / personal cleansing which would be easy to carry out and at the same time would be cost effective. Yet further object is directed to manufacture of coated bars which can be simply and easily obtained involving simple and cost effective gadgets thereby making its manufacture simple and cost effective. Importantly, in accordance with another aspect of the present invention the system for providing the coated bars involve means for recovering the unused liquid coat during the coating cycle and recycle the same for use in subsequent coating operations. This would favor cost effective utilization of the UV curable coat material. The exposure of the coated surface to the UV/EB for curing is preferably for a period of 0.5-5 sec The selective UV/EB curing system of the invention preferably involves coating surface with a photo curable resin consisting mainly of initiator, monomer and oligomer, which is in-situ polymerized to thereby obtain a film of high molecular weight cross-linked polymer. The level of cross-linking desired is based on the choice of monomer and oligomer (s) in the formulation. Importantly, curing the above system of the invention, high surface gloss, effective control on film properties, fast curing and no reaction by products coatings could be generated. The system of the invention makes selective use of radiation-curable coatings containing no solvents is made whereby no additional energy is required to volatilize an organic solvent. Additionally, the selective radiation curing system avoids the use of heat in the process such that system is operable at room temperature, thereby reducing facility/energy consumption and allowing for more rapid and efficient maintenance of the curing equipment. In addition, due to the low operating temperature, UV/EB-curable coats can be used on temperature-sensitive substrates. Also, UV/EB-curable system requires only a short time period for the radiative energy to generate the initiating species in the coating. As a result of this rapid curing rate (usually less than a few seconds), faster production throughputs are achieved. The details of the invention, its objects and advantages are explained hereunder in greater detail in relation to non-limiting exemplary illustrations/figures. The method of carrying out the preferred UV curable coating of bars in accordance with the present invention is schematically illustrated in accompanying Figure 1. As illustrated in said Figure 1, the method basically involves feeding preformed bars for the desired coating application preferably UV/EB coating in a spray coating unit followed by subjecting the thus coated bars to UV/EB curing in an UV/EB curing chamber. After the coated bars are duly coated, the coated bars are ready for packages/use. In the above process, the step of UV/EB curing is based on instantaneous polymerization of UV/EB curable coating upon exposure to UV/EB radiation. In accordance with a preferred aspect the spray coating of the bars are carried out in 5 sides of a bar with a UV curable liquid polymer. One of the sides is thus left uncoated to constitute the first contact surface of the bar for the fabric/detergent/personal cleansing activity using the same. After the coating is completed, the coated bars are subjected to UV curing. For the purpose, the coated bars are exposed to UV light for a period of 0.5- 5 sec. The above process of the invention provides for achieving instantaneous formation of a 100% solid polymer film by way of a cost effective and simple process. The Liquid Coating Application on the bar surface is carried out in the coating application chamber. For such purpose, the bars move into the chamber via appropriate conveying system to ensure that the bars are appropriately oriented and only the surfaces that need to be coated are exposed to the coating mist. It is also required that the inter bar distance is appropriately maintained to avoid shadowing of surfaces. The in-feed to the coating application chamber can be done continuously or intermittently (with a dwell time). In accordance with another aspect of the invention, the method for coating of the bars comprise step of collecting unused coating liquid and recycling the same. The method as stated above further involves the use of UV/EB curing. For such purpose the coated surface of the bar is adapted to provide the required level of UV/EB radiation for curing of liquid coating. Conventionally, the UV curing system involves placement of lamps inside an enclosed chamber and the object to be exposed is fed in and out of the chamber through a belt driven conveyor. As shown in Figure 1, the system basically involves the conveyor means (CM) for carrying the preformed bars for the coating in a coating application chamber (CAC) and subsequent curing in a curing chamber (CC) fitted with UV lamps (UVL) to finally obtain the coated bars (CB). The conveyor for such purpose is adapted to traverse through a spraying unit and thereafter through an UV curing unit. To achieve such method of coating the preformed bars are first loaded on the conveyor means and thereafter allowed to traverse on the conveyor to first reach the coating unit. The coating unit is preferably adapted for spray coating using spray nozzles (SN), of the selected side surfaces preferably five sides of the preformed bar. After the coating is attended on the selected side surfaces of the preformed bar, the coated bars are then allowed to traverse through the curing chamber. The curing chamber is preferably an UV curing system adapted to expose the preformed bar to UV light from the UV lamps (UVL) for a period of 0.5-2 sec. The UV chamber need to have desired level of intensities on all coated surface to achieve required level of curing. The UV intensity can be achieved by having an appropriate arrangement of lamps-reflector assembly that would provide the desired level of UV intensity on all the five surfaces. A simplest method to achieve this is by placing a set of lamps for each face of the coated bar. The lengths of the lamp can be selected based on the speed of the said bar. In accordance with an embodiment, the system for the UV curable coating & curing for bar coating of the invention comprise of the following units. a. bar orientation and feeding system b. Coating application chamber c. UV curing chamber with conveyor BAR ORIENTATION AND FEEDING SYSTEM The bars to be coated are appropriately oriented and fed in to the application chamber for liquid coating by means of a conveyor device. The speed of the conveyor can be adjusted to achieve the desired throughput. COATING APPLICATION CHAMBER: The system can advantageously include a specifically developed spray booth which would selectively facilitate application of coating over the objects (bars) on desired surface preferably on all visible surfaces in a clean environment. In one embodiment of the invention, the application of coating can be achieved by placing multiple spray nozzles around the moving object (bars) to achieve uniform coverage of coating on all sides. U.V. CURING CHAMBER The objective of the UV chamber is to provide uniform intensity of UV light from all sides for the objects entering the chamber. Typically it is equipped with two small openings for the passage of the conveyor, which permits the entry of the wet bars for UV curing and exit of the cured bars for packaging. It is thus possible by way of the above disclosed method and system of the invention to provide a simple and cost-effective manner of manufacture of water barrier coated bars preferably UV/EB curable coated bars especially for formulations such as detergent/cleaning agents which would improve the end use/application and storage stability of such bars and avoid problems of bar sogginess/softening due to contact with water. WE CLAIMS:- A method for producing bars of varied formulations having a water resistant coat applied at least on a surface portion thereof, said water resistant coat comprising : i. subjecting the selected surface portion of a preformed bar of desired shape /configuration and formulation to step of polymeric coating using a polymeric coat material and ii. obtaining desired water barrier/resistant coated bars therefrom. A method for producing water resistant coated bars of varied formulation such as detergent/cleansing formulations having at least on one surface portion thereof said water resistant coat as claimed in claim 1 comprising : i. subjecting the preformed bar of desired shape/configuration and formulation to step of polymeric coating using a polymeric coat material preferably UV/EB curable coat material; and ii. curing the thus coated polymeric bar to thereby obtain the coated bars of desired water barrier coat/surface finish. A method for producing water resistant coated bars as claimed in any one of claims 1 or 2 wherein said polymer coating is made of polymeric materials having water barrier property. A method for producing water resistant coated bars as claimed in any one of claims 1 or 3 wherein the polymeric coat is obtained by in-situ polymerization to obtain solid polymer coatings substantially free of any solvent or high temperature melt. A method for producing water resistant coated bars as claimed in any one of claims 1 or 4 comprising using UV/EB curing method involving coating the bar surface with a photo curable resin consisting mainly of initiator, monomer and oligomer, which is preferably in-situ polymerized to thereby obtain a film. A method for producing water resistant coated bars as claimed in any one of claims 1 to 5 wherein it is carried out at selective low operating temperatures whereby UV/EB-curable coats can be provided on temperature-sensitive substrates. A method for producing water resistant coated bars as claimed in any one of claims 1 to 5 wherein the exposure of the coated surface to the UV/EB for curing is preferably for a period of 0.5-5 sec. A method for producing water resistant coated bars as claimed in any one of claims 1 to 7 wherein the coating of the bar is carried out on all sides except the side adapted for first use/application. A method for producing water resistant coated bars as claimed in any one of claims 1 to 8 wherein the preformed bars are continuously or regular batches coated in a coating chamber and transferred to a curing chamber for curing of the coat and wherein the inter bar distance is selectively determined to avoid shadowing of surfaces in the process. A machine for carrying out the method of claim 1 comprising : - means for subjecting at least a selective surface portion of preformed bar to a water barrier polymeric coat preferably UV/EB coat; - means for providing/curing the thus coated bars. A machine for producing water resistant coated bars as claimed in claim 10 for an online production of coated bars comprising : - means for supplying the preformed bars for said water barrier coating preferably UV/EB curable coat application. - means for spray coating the selected surface portion of the preformed bar using said liquid coat material; - means for drying/curing preferably UV/EB curing means to obtain the coated bars. A machine for producing water resistant coated bars as claimed in any one of claims 10 or 11 comprising : - means to orient and feed the preformed bars into a coating module; - coating module consisting of (i) an application chamber for applying the coating to the exposed surfaces of a bar (ii) a curing chamber adapted to subject the bars preferably to uniform UV light source with the desired intensity to achieve curing. 13. A machine for producing water resistant coated bars as claimed in anyone of claims 10 to 12 comprising spraying means as the preferred mode of coating application. 14. A machine for producing water resistant coated bars as claimed in claim 13 wherein the said spraying means is adapted for airless or air/gas assisted spraying technique. 15. A machine for producing water resistant coated bars as claimed in any one of claims 10 to 14 wherein said application chamber is provided with ultrasonic spray or a liquid curtain means for the coating application. 16. A machine for producing water resistant coated bars as claimed in any one of claims 10 to 15 comprising means for recovering the unused liquid coat during the coating cycle and recycle the same for use in subsequent coating operations. 17. A machine for producing water resistant coated bars as claimed in any one of claims 10 to 16 comprising conveyor means for feeding in the bars for coating and also the coated bars for curing. 18. A method for producing water resistant coated bars of varied formulations such as detergent/cleansing formulations and a machine for carrying out such method substantially as herein described and illustrated with reference to the accompanying figures. Dated this 31st day of October 2003 Dr. Sanchita Ganguli of S. MAJUMDAR & CO Applicant's Agent

Documents:

955-mum-2002-cancelled pages(3-1-2005).pdf

955-mum-2002-claims(granted)-(3-1-2005).doc

955-mum-2002-claims(granted)-(3-1-2005).pdf

955-mum-2002-correspondence 1(31-10-2003).pdf

955-mum-2002-correspondence 2(12-9-2006).pdf

955-mum-2002-correspondence(ipo)-(20-1-2006).pdf

955-mum-2002-drawing(3-10-2003).pdf

955-mum-2002-form 1(1-11-2002).pdf

955-mum-2002-form 19(31-10-2003).pdf

955-mum-2002-form 2(granted)-(3-1-2005).doc

955-mum-2002-form 2(granted)-(3-1-2005).pdf

955-mum-2002-form 3(1-12-2002).pdf

955-mum-2002-form 3(10-1-2005).pdf

955-mum-2002-form 5(31-10-2003).pdf

955-mum-2002-power of attorney(29-4-2004).pdf

955-mum-2002-power of attorney(5-12-2002).pdf