Title of Invention

"A PROCESS FOR PREPARATION OF WATER BASED SOLID STICK ADHESIVE"

Abstract

This invention relates to A Process for Preparation of water based solid stick adhesive comprising a four stage process wherein in the first stage comprises mixture of 25%-80% by weight of water, 3 to 30% by weight of a polyol and 0.2 to 10% by weight of surfactant, at a time; followed by addition of 5-40% by weight of a polymer with constant stirring; the second stage comprises subjecting the mixture thus obtained to heating at 40-50 °C and adding 2 to 30% by weight of (C-12 to C-22) aliphatic carboxylic acid with constant strirring; the third stage comprises raising of the temperature from 50 to 80 °C for 10-60 minutes and adding 1 to 15% by weight of alkali metal hydroxide followed by addition of 1 to 20% by weight of wax with stirring and then adding further 1 to 15% by weight of alkali metal hydroxide; and the fourth stage comprising raising of the temperature till homogeneous mass is obtained, adding 1-10% by weight of preservatives and 0.1-1% by weight of perfume and then pouring into mould and allowing to cool to set into the solid stick adhesive of the present invention, wherein said polyol is selected from polyethylene glycol, polypropylene glycol and glycerol, said surfactant is selected from nonyl phenol ethoxylate, dioctyl sulfo succinate, linear alkyl benzene sulfonate and sodium lauryl sulphate; the said polymer is selected from polyvinyl alcohol, dextrin, polyvinyl pyrrolidone, polyvinyl acetate and polyacrylic acid; said carboxylic acid is selected from stearic acid, glutamic acid, palmitic acid and myristic acid, and preservative is selected from calcium propionate, benzoic acid and sodium benzoate.

Full Text

FILED OF INVENTION This invention relates to a process for preparation of water based soild stick adhesive for use for applications like gluing paper, cardboard, etc. PRIOR ART The basic component of the glue stick is binder and possessing good adhesive character. The glue stick has applications in bonding paper, cardboard etc. One of the process known in the art for preparation of glue stick as per U.S patent no 5,362,792 comprises an EVA copolymer in the concentration of 55-65%, aromatic modified aliphatic resin as a low temperature tackifying resin in the concentration of 10-20% and petroleum hydrocarbon resin as a high temperature tackifying resin in the concentration range of 20-30%. The materials described above are processed into a stick form for use in a glue gun and the glue stick thus obtained exhibits a viscosity between 80,000cps to 2,000cps over a temperature range of 250°F to 380°F. A disadvantage of the above composition is that, it is hot melt type which cannot be used at room temperature. Another process known in the art as per U.S. patent no. 3,787,346 comprises 15-30% of polyvinyl pyrrolidone (M. W. -90,000-700,000), 2-6% of dextrin, as adhesive component, 10-18% of wax acid mixture (Montan acid containing saturated aliphatic carboxylic acids having 19-33 carbon atoms) as structuring substance, 0-5% of sodium lauryl sulphate as wetting agent, 2-6% of sodium lauryl sulphoacetate as anionic surfactant, 5-25% of ethanol and 10-45% of water as polar solvent, and many other additives which includes 0-5% of propylene glycol, 0-2% of methylcellulose, 0-2% of amylum non mucilaginosum, 0-1% of hydroxy ethyl cellulose, 0-18%of wax ester, 15-25% of glycerol, and 10-15% of sorbitol. For preparation of solid adhesive stick, ingredients other than the polymer are mixed and heated between 75-85°C until a homogenous solution is formed. The polyvinyl pyrrolidone is then added slowly and the mixture is stirred until it becomes homogenous and air free. It is then poured into a mould and allowed to set. A disadvantage of the above process is that, it requires combination of polyvinyl pyrrolidone, dextrin along with montan acid as adhesive components to give desired adhesion property. Yet another process known in the art as per U.S patent no. 6,417,261 comprises 15-35% of polyurethane dispersion (30-60% solid content) alongwith 1-15% of polyvinyl pyrrolidone (M.W. 50,000 to 3,000,000) as adhesive component, 3-12% of sodium salt of fatty acid (C12-C22) as gelling agent, 40-55% of water and 0-25% of other auxiliaries, while auxiliaries include polyethylene glycol and polypropylene glycol (M.W-200-4,000), Preservatives, moisture regulators, water soluble plasticizers, resins, caprolactam and perfumes. This process requires soap gel forming constituents, the polyurethance dispersion, the polyvinyl pyrrolidone and the auxiliaries to be mixed together, heated to temperatures of at least 50°C and preferably up to 100°C, until a uniform mixture is obtained. The resulting mixture is poured into moulds and is then left to cool in the absence of mechanical action to form a gel. A disadvantage of the above process is that, it is isocyanide based product which is health hazardous. Still another process known in the art as per U.S. patent no. 4,292,229, comprises 5-40% by weight polyurethane rubber and carboxylated butadiene-arcylonitrile rubber used as polymeric component, 1-5% of benzylidence sorbitol as a structuring agent, and 5-20% of phenolic resin preferably phenol formaldehyde resin and non aqueous solvents like methyl ethyl ketone, 2-methoxy ethanol, isobutanol used in the proportion of 40-80%. In this process benzylidene sorbitol is dissolved in the mixture of the two solvents under reflux with stirring. After cooling to about 70°C, the two rubbers are added, and the mixture is stirred well at that temperature until homogenous (about 4 hours). The resin is added, and the mixture was stirred until the resin gets dissolved (about 30 min). The mixture is then poured into conventional glue-stick dispensers and allowed to cool to room temperature. A limitation of this above process is that the process uses inflammable solvent with low flash point. Another drawback of the above process is that compositions is health hazardous as vapours of solvent used in glue stick, keep on vaporising during the usage, which may be inhaled by user and may be health hazard. Yet another process known in the art as per U.S patent no. 4,618,643, comprises a co-polyester from an acid component comprising 45 to 48 mole % terephthalic acid, 38 to 45 mole % isophthalic acid and 10 to 15 mole % azelaic acid, and hydroxyl component comprising 1,4 butane diol and 1,6 hexane diol in a molar ratio of (90 to 95):(5 to 10), and a polymeric plasticizer component a poly caprolactone or selected hydroxy polyester to an extent of 3 to 4% by weight of the copolyester. A disadvantage of the above process is that the co-polyester used in this case during production undergoes degradation and hydrolytic reactions catalyzed by carboxylic acids if it is not properly stabilized with an antioxidant. OBJECTS OF PRESENT INVENTION An object of the present invention is to propose a process for preparation of water based glue stick for use such as for gluing paper, card board etc. STATEMENT OF INVENTION According to this invention there is provided a process for preparation of water based solid stick adhesive comprising a four stage process wherein in the first stage comprises mixture of 25-80% by weight of water, 3 to 30 % by weight of a polyol and 0.2 to 10% by weight of surfactant, at a time; followed by addition of 5-40% by weight of a polymer with constant stirring; the second stage comprises subjecting the mixture thus obtained to heating at 40-50 °C and adding 2 to 30 % by weight of (C-12 to C-22) aliphatic carboxylic acid with constant stirring; the third stage comprises liaising of the temperature from 50 to 80°C for 10-60 minutes and adding 1 to 15% by weight of alkali metal hydroxide followed by addition of 1-20% by weight of wax with stirring and then adding further 1 to 15% by weight of alkali metal hydroxide; and the fourth stage comprises raising of the temperature 90 to 95°C and maintaining the temperature till homogenous mass is obtained, adding 1-10% by weight of preservatives and 0.1-1% by weight of perfume and then pouring into mould and allowing to cool to set into the solid stick adhesive of the present invention, wherein said polyol is selected from polyethylene glycol, polypropylene glycol and glycerol, said surfactant is selected form nonyl phenol ethoxylate, dioctyl sulfo succinate, linear alkyl benzene sulfonate and sodium lauryl sulphate; the said polymer is selected from polyvinyl alcohol, dextrin, polyvinyl pyrrolidone, polyvinyl acetate and polyacrylic acid; said carboxylic acid is selected from stearic acid, glutamic acid, palmitic acid and myristic acid, and preservative is selected from calcium propionate, benzoic acid and sodium benzoate. DESCRIPTION OF INVENTION In this present invention, the glue stick primarily comprises a polymer as the adhesive component and (C12-C22) aliphatic carboxylic acid along with alkali metal hydroxide as the structuring agent. Other than the above three major components, a few auxiliary additives like polyols, surfactants, preservatives and perfumes are also included in the composition for imparting specific properties. The process is carried out in a container equipped with stirrer and thermometer using a water bath in four stages. In the first stage 25 to 85% by weight of water, 3 to 30% by weight of polyol and 0.2 to 10% by weight of surfactant are added one by one. Polyol is selected from polyethylene glycol, polypropylene glycol and glycerol, preferably a combination of polyethylene glycol and glycerol in the ratio by weight of (3-25):(l-15) is taken. Surfactant is selected from nonyl phenol ethoxylate, dioctyl sulfo succinate, linear alkyl benzene sulfonate and sodium lauryl sulphate, preferably a combination of nonyl phenol ethoxylate and dioctyl sulfo succinate in the ratio of (0.1-0.5):(0.1-1) is taken. The mixture is stirred and then 5-40% by weight of polymer is added under constant stirring and mixing is continued till the mixture becomes homogenous. The polymer is selected from polyvinyl alcohol, dextrin, polyvinyl pyrrolidone, polyvinyl acetate and polyacrylic acid. However a combination of polyvinyl alcohol and polyvinyl pyrrolidone in the ratio of (0.5-10): (1-5) is preferred. In the second stage of the process the mixture is heated to 40-50°C and 2-30% by weight of aliphatic carboxylic acid is added under constant stirring and the temperature is maintained until it becomes homogenous. The carboxylic acid taken has preferably 12 to 22 carbon atoms and is selected from stearic acid, glutamic acid, palmitic acid and myristic acid. In the third stage, the temperature of the resultant mass is raised to 50 to 80°C and maintained preferably at 65-70°C for 10-60 minutes, preferably 20-25 minutes. To the mass thus obtained, 1 to 15% by weight of alkali metal hydroxide, preferably sodium hydroxide is added. This is followed by addition of 1-20% by weight of wax. The mixture is stirred for 30 to 45 minutes and further quantity of 1 to 15% by weight of alkali metal hydroxide is added. In the fourth stage, temperature is raised to 90 -95°C with stirring and temperature is maintained till a homogenous mixture is obtained. To this mixture 1-10% of a preservative and 0.1 to 1% by weight of a perfume are added. The preservative is selected from calcium propionate, benzole acid and sodium benzoate. The mass thus prepared is poured into the mould and allowed to cool to set at room temperature to obtain solid stick adhesive. WORKING EXAMPLES The invention will now be illustrated with two working examples which are intended to illustrate working of invention and are not intended to be taken restrictively to imply any limitation on the scope of present invention. EXAMPLE 1 40 gm of water, 10.0 gm of glycerol, 20.0 gm of polyethylene glycol and 2.0 gm of nonyl phenol ethoxylate, 1.5 gm of dioctyl sulfo succinate were taken in a container equipped with mechanical stirrer and thermometer. The mixture was agitated for 5 minutes and then 12 gm of polyvinyl alcohol was slowly added into the mixture and stirring continued until the mixture became homogenous. Afterwards, the container was placed in a water bath, the temperature of the reaction mixture was raised to 45°C followed by addition of 20 gm of (C12-C22) aliphatic carboxylic acid and stirring was continued for 20 minutes. The temperature was further raised to 70°C, and 5.0gm of sodium hydroxide was added. To this mass, 8.0 gm of wax was added followed by addition of 5.0 gm of sodium hydroxide and stirring was continued for another 45 minutes. Finally the temperature was raised to 95°C and maintained till a homogenous mixture was obtained. To this 2 gm of calcium propionate as preservative and 0.5 gm of perfume was added. The mass so prepared was poured into the mould and allowed to cool to set a room temperature to form the solid stick adhesive. EXAMPLE 3 40.0 gm of water, 8.0 gm of glycerol, 12.0 of polyethylene glycol and 1.5 gm of dioctyl sulfo succinate were taken in a container equipped with stirrer and thermometer. The mixture was agitated for 5 minutes then 7.0 gm of polyvinyl alcohol and 5 gm of polyvinyl pyrrolidone were slowly added into it and stirring was continued until the mixture became homogenous. Afterwards, the container was placed in a water bath, the temperature of the reaction mixture was raised to 45°C followed by adding of 18.0 gm of (C12-C22) aliphatic catboxlic acid and stirring was carried out for 30 minutes. The temperature was further raised to 70°C and 5.0gm of sodium hydroxide was added. To this mass 5.0 gm of wax followed by 5.0gm of sodium hydroxide solution were added and mixture stirred for 30 minutes. Finally, the temperature was raised to 95°C and maintained till a homogenous mixture was obtained. To this 1.5 gm of sodium benzoate as preservative and 0.5 gm of perfume was added. The mass so prepared was allowed to pour in the mould and to set at room temperature to obtain the solid stick adhesive. It is to be noted that present invention is susceptible to modifications changes and adaptations by those skilled in the art. Such, variant embodiments incorporating the concepts and features of the present invention, are intended to be within the scope of the present invention, which is further set forth under the following claims: WE CLAIM: 1. A process for preparation of water based solid stick adhesive comprising a four stage process wherein in the first stage comprises mixture of 25-80% by weight of water, 3 to 30% by weight of a polyol and 0.2 to 10% by weight of surfactant, at a time; followed by addition of 5-40% by weight of a polymer with constant stirring: the second stage comprises subjecting the mixture thus obtained to heating at 40-50°C and adding 2 to 30% by weight of (C-12 to C-22) aliphatic carboxylic acid with constant stirring; the third stage comprises raising of the temperature from 50 to 80 °C for 10-60 minutes and adding 1 to 15% by weight of alkali metal hydroxide followed by addition of 1-20% by weight of wax with stirring and then adding further 1 to 15% by weight of alkali metal hydroxide; and the fourth stage comprises raising of the temperature 90 to 95 °C and maintaining the temperature till homogenous mass is obtained, adding 1-10% by weight of preservatives and 0.1-1% by weight of perfume and then pouring into mould and allowing to cool to set into the solid stick adhesive of the present invention, wherein said polyol is selected from polyethylene glycol, polypropylene glycol and glycerol, said surfactant is selected form nonyl phenol ethoxylate, dioctyl sulfo succinate, linear alkyl benzene sulfonate and sodium lauryl sulphate; the said polymer is selected from polyvinyl alcohol, dextrin, polyvinyl pyrrolidone, polyvinyl acetate and polyacrylic acid; said carboxylic acid is selected from stearic acid, glutamic acid, palmitic acid and myristic acid, and preservative is selected from calcium propionate, benzoic acid and sodium benzoate. 2. A process as claimed in claim 1 wherein said polyol is preferably a mixture of polyethylene glycol and glycerol in the ratio of (3-25):(1-15). 3. A process as claimed in claim 1 wherein said surfactant is preferably a mixture of nonyl phenol ethoxylate and dioctyl sulfo succinate in the ratio of (0.1-0.5): (0.1-1). 4. A process as claimed in claim 1 wherein said polymer is preferably a mixture of polyvinyl alcohol and polyvinyl pyrrolidone in the ratio of (0.5-10): (1-5). 5. A process as claimed in claim 1 wherein temperature during said third stage is preferably maintained at 65-70°C. 6. A process for preparation of water based solid stick adhesive as substantially described and illustrated herein.

Documents:

1204-DEL-2003-Abstract-(14-09-2009).pdf

1204-del-2003-abstract.pdf

1204-DEL-2003-Claims-(14-09-2009).pdf

1204-del-2003-claims.pdf

1204-DEL-2003-Correspondence-Others (06-11-2009).pdf

1204-DEL-2003-Correspondence-Others-(14-09-2009).pdf

1204-del-2003-correspondence-others.pdf

1204-del-2003-correspondence-po.pdf

1204-del-2003-description (complete).pdf

1204-del-2003-form-1.pdf

1204-del-2003-form-18.pdf

1204-del-2003-form-2.pdf

1204-DEL-2003-Form-3-(14-09-2009).pdf

1204-DEL-2003-GPA-(04-06-2010).pdf

1204-DEL-2003-GPA-(14-09-2009).pdf

1204-del-2003-gpa.pdf