POLYMER COATED PAPER RECYCLING PROCESS AND COMPOSITION

Abstract

The present invention provides a composition and process for preparing a depolymered paper product from polymer-coated paper waste, comprising the steps of treating shredded polymer-coated paper waste with a polymer removing composition comprising a mixture of a solvent component, a surfactant component, and an acidic component.

Claims

1-29. (canceled)

30. A process for removing a polymer coating from polymer-coated paper waste to provide a depolymered paper product, comprising the steps of: providing shredded polymer-coated paper waste; combining the shredded polymer-coated paper waste with a polymer removing composition in a mixing tank to provide a mixture of the polymer-coated paper waste and the polymer removing composition, wherein the polymer removing composition comprises a mixture of a solvent component, a surfactant component, and an acidic component; reacting the mixture for a time sufficient to remove the polymer from the paper to provide a first depolymered paper product; removing excess polymer removing composition from the first depolymered paper product to provide a wet depolymered paper product; washing the wet depolymered paper product with a washing solution comprising water and detergent and/or a low boiling solvent to provide a washed depolymered paper product; and drying the washed depolymered paper product to provide the final paper product.

31. The process of claim 30, wherein the polymer-coated paper waste is silicone release paper, polymer coated paper cups, or a combination of both.

32. The process of claim 31, wherein the polymer coated paper cups are polyethylene coated paper cups.

33. The process of claim 32, further comprising a flotation or filtration step to remove the polymer separated from the first depolymered paper product.

34. The process of claim 33, wherein the polymer removing composition comprises from about 70 wt % to about 100 wt %, preferably from about 70 wt % to about 98 wt %, more preferably about 90 wt %, of the solvent component, wherein the solvent component comprises one or more solvents selected from acetone, hexane, mineral spirits, water, cyclohexane, naphtha, benzyl alcohol, isoparaffin, ethanol, isopropanol, toluene, xylene, pyridine, kerosene, and gasoline.

35. The process of claim 34, wherein the polymer removing composition comprises from about 0 wt % to about 15 wt %, preferably from about 0.5 wt % to about 15 wt %, more preferably from about 1 wt % to about 10 wt %, and more preferably from about 2 wt % to about 5 wt %, of the surfactant component, wherein the surfactant component comprises one or more surfactants selected from sulfonic acid surfactants, sulfonate surfactants and sulfate surfactant.

36. The process of claim 35, wherein the surfactant component comprises sodium dodecyl sulfate, ammonium lauryl sulfate, sodium laureth sulfate, alkylbenzenesulfonic acid, methanesulfonic acid or any combination thereof.

37. The process of claim 36, wherein the polymer removing composition comprises from about 0 wt % to about 20 wt %, preferably from about 0.5 wt % to about 20 wt %, more preferably from about 0.5 wt % to about 2 wt %, of the acidic component, wherein the acidic component comprises one or more acids selected from sulfuric acid, acetic acid, hydrochloric acid, formic acid, citric acid, and nitric acid.

38. The process of claim 37, wherein the step of reacting the mixture is carried out at temperature between 25 to 100° C., and the step of washing is carried out at a temperature of from about 20° C. to about 95° C., preferably at a temperature of from about 50° C. to about 80° C.

39. The process of claim 38, wherein the step of reacting the mixture is carried out over a period of time from about 2 minutes to about 300 minutes.

40. The process of claim 39, wherein the step of reacting the mixture comprises mechanical agitation of the mixture.

41. The process of claim 40, wherein the step of removing excess polymer removing composition is carried out by centrifugation or by pressing the mixture to remove the composition.

42. The process of claim 30, wherein polymer removing composition comprises 81 wt % kerosene, 15 wt % xylene, 1.5 wt % sulfuric acid, 0.5 wt % nitric acid, 1 wt % sodium dodecyl sulfate (SDS), 0.5 wt % ammonium lauryl sulfate (ALS), and 0.5 wt % methanesulfonic acid.

43. A polymer removing composition for use in preparing a depolymered paper product from polymer-coated paper waste, wherein the polymer removing composition comprises from about 70 wt % to about 100 wt % of a solvent component, from about 0 wt % to about 15 wt % of a surfactant component, from about 0 wt % to about 20 wt % of an acidic component.

44. The composition of claim 43, wherein the polymer removing composition comprises about 90 wt % of the solvent component, wherein the solvent component comprises one or more solvents selected from acetone, hexane, mineral spirits, water, cyclohexane, naphtha, benzyl alcohol, isoparaffin, ethanol, isopropanol, water, toluene, xylene, pyridine, kerosene, and gasoline.

45. The composition of claim 44, wherein the polymer removing composition comprises from about 0.5 wt % to about 10 wt %, preferably from about 2 wt % to about 5 wt %, of the surfactant component, wherein the surfactant component comprises one or more surfactants selected from sulfonic acid surfactants, sulfonate surfactants and sulfate surfactants.

46. The composition of claim 35, wherein the surfactant component comprises sodium dodecyl sulfate, ammonium lauryl sulfate, sodium laureth sulfate, alkylbenzenesulfonic acid, methanesulfonic acid or any combination thereof.

47. The composition of claim 36, wherein the polymer removing composition comprises from about 0.1 wt % to about 2 wt % of the acidic component, wherein the acidic component comprises one or more acids selected from sulfuric acid, acetic acid, hydrochloric acid, formic acid, citric acid, and nitric acid.

48. The composition of claim 37, wherein the polymer removing composition comprises less than about 10 wt % water.

49. The composition of claim 43, wherein the polymer removing composition comprises 81 wt % kerosene, 15 wt % xylene, 1.5 wt % sulfuric acid, 0.5 wt % nitric acid, 1 wt % sodium dodecyl sulfate (SDS), 0.5 wt % ammonium lauryl sulfate (ALS) and 0.5 wt % methanesulfonic acid.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0028] FIG. 1 is a schematic depiction of a process for preparing a depolymered paper product, in accordance with one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0029] The term “polymer coated paper” is used herein to refer to a grade of paper having one or both sides being coated with a polymer in order to strengthen papers or give new properties. It includes polymer coated papers products such as coated paper cups, silicone release papers, and the like.

[0030] The term “release paper” is used herein to refer to a grade of paper having one or both sides being coated with a non-sticking material, or release agent, typically a silicone-based material. Release paper is typically used a backing paper for adhesive labels, self-adhesive films, self-adhesive tapes, and the like.

[0031] The term “silicone” is used herein to refer to a general category of synthetic polymers with a siloxane main chain made of repeating silicon to oxygen bonds, wherein each silicon atom is bonded to organic groups (such as methyl groups in polydimethylsiloxane (PDMS)). The term “silicone release agent” refers to the thin layer of silicone-based material coated on a paper substrate to provide a silicone-coated release paper product.

[0032] The term “depolymered paper” is used herein to refer to the paper product obtained after a polymer coating has been removed.

[0033] As used herein, the term “about” refers to a +/−10% variation from the nominal value. It is to be understood that such a variation is always included in a given value provided herein, whether or not it is specifically referred to.

[0034] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0035] The present invention provides a process for removing a polymer coating from polymer-coated paper waste. The process is carried out by treating the coated paper waste with a polymer removing composition to remove the polymer layer in order to provide a depolymered paper product that can be recycled for use in preparing a new paper product. In one embodiment, the excess polymer removing composition removed from the depolymered paper may be recovered for re-use in further polymer removal steps. Recycling of the polymer removing composition thus minimizes the consumption and unnecessary waste of reagents and water resources used to prepare the polymer removing composition. In one embodiment, the polymer coating is a silicone polymer coating. In one embodiment, the polymer coating is a polyethylene coating.

[0036] In accordance with the present invention, the polymer removing step can advantageously be carried out under mild reaction conditions using a polymer removing composition. The use of mild reaction conditions minimizes the reduction in quality of the resulting fibers, thus maximizing the recovery and yield of useful fibers for use in a recycled paper product.

[0037] In a preferred embodiment, the first step in the process for preparing the depolymered paper product involves shredding the polymer-coated paper waste prior to treatment with the polymer removing composition. Accordingly, in one embodiment, the process starts with dry shredding the paper waste to a size suitable for mixing of the paper shred with the polymer removing composition. In one embodiment, the size of the shredded paper is between 5 mm to 50 cm, more preferably between 30 and 300 mm, most preferably between 80 and 150 mm. Shredding the paper to too small results in fiber damage that decreases the quality of the resulting depolymered paper, while large papers are hard to handle and mix. In the next step, shredded papers are entered into the mixing tank with a specific solution.

[0038] In one embodiment, the process comprises the step of combining the shredded polymer-coated paper waste with a polymer removing composition in a mixing tank to provide a mixture of the polymer-coated paper waste and the polymer removing composition

[0039] In accordance with the present invention, the polymer removing composition comprises a mixture of a surfactant component, a solvent component, an acidic component with temperature between ambient and 95 degrees Celsius

[0040] In one embodiment, the solvent component of the polymer removing composition comprises one or more solvents selected from acetone, hexane, mineral spirits, water, cyclohexane, naphtha, benzyl alcohol, isoparaffin, ethanol, isopropanol, toluene, xylene, pyridine, kerosene, and gasoline.

[0041] In one embodiment, the polymer removing composition comprises from about 70 wt % to about 100 wt %, preferably from about 70 wt % to about 98 wt %, more preferably about 90 wt %, of the solvent component.

[0042] In one embodiment, the surfactant component of the polymer removing composition comprises one or more surfactants. The surfactant component acts as an emulsifier of the solvents and the aqueous acidic components to ensure complete mixing of the de-siliconizing composition, while also facilitating removal of the polymer layer from the coated paper.

[0043] In one embodiment, the one or more surfactants are selected from sulfonic acid surfactants, sulfonate surfactants and sulfate surfactants.

[0044] In one embodiment, the surfactant component comprises sodium dodecyl sulfate, ammonium lauryl sulfate, sodium laureth sulfate, alkylbenzenesulfonic acid, methanesulfonic acid, or any combination thereof.

[0045] In one embodiment, the polymer removing composition comprises from about 0 wt % to about 15 wt %, preferably from about 0.5 wt % to about 15 wt %, more preferably from about 1 wt % to about 10 wt %, and yet more preferably from about 2 wt % to about 5 wt %, of the surfactant component.

[0046] In one embodiment, the polymer removing composition comprises an acidic component comprising one or more acids selected from sulfuric acid, acetic acid, hydrochloric acid, formic acid, citric acid, and nitric acid.

[0047] In a preferred embodiment, the acidic component comprises sulfuric acid.

[0048] In one embodiment, the polymer removing composition comprises from about 0 wt % to about 20 wt %, preferably from about 0.5 wt % to about 20 wt %, more preferably from about 0.5 wt % to about 2 wt %, of the acidic component.

[0049] In one embodiment, the process comprises the step of reacting the mixture for a time sufficient to remove the polymer from the paper to provide a first depolymered paper product.

[0050] In one embodiment, the shredded paper is placed in the polymer removing composition and mixed. In one embodiment, the mixing comprises mechanical agitation. Although optional, the mixing step can accelerate the polymer removal from the paper by up to 5 times faster than without mixing. It is, however, within the scope of the present invention that the reaction step be carried out without mixing.

[0051] In one embodiment, the step of reacting the mixture is carried out at ambient temperature and pressure. Care should be taken that all of the papers are maintained in contact with the polymer removing composition to ensure complete reaction.

[0052] In one embodiment, the step of reacting the mixture is carried out over a period of time from about 2 minutes to about 300 minutes.

[0053] After a sufficient reaction time, the depolymered paper product is ready to be removed from the composition. As the papers being treated can absorb up to about 100% of its weight of the solution, removal and recovery of the excess polymer removing composition is critical for reuse in subsequent polymer removal processes.

[0054] Accordingly, the process of the present invention also comprises the step of removing excess polymer removing composition from the depolymered paper product to provide a wet depolymered product. In one embodiment, the step of removing excess polymer removing composition is carried out by centrifugation. In one embodiment, the step of removing excess polymer removing composition comprises pressing the mixture to remove the solution.

[0055] In one embodiment, the step of removing excess polymer removing composition also comprises a drying step. In a preferred embodiment, the papers are dried under a vacuum and/or without applying heat in this step in order to be safe.

[0056] In a preferred embodiment, the step of removing excess polymer removing composition results in the removal and recovery of about 97 to 99% of the solution for reuse in the process.

[0057] The process of the present invention further comprises the step of washing the wet depolymered paper product with a washing solution comprising water and detergent and/or a low boiling solvent to provide a washed depolymered paper product. This step is carried out to remove the residual composition.

[0058] In one embodiment, the washing step is carried out at a temperature of from about 20° C. to about 95° C., preferably from about 50° C. to about 80° C., more preferably at a temperature of about 70° C. The use of relatively mild temperatures minimizes the energy requirements for carrying out the de-siliconizing process.

[0059] The washing step can be carried out with a washing solution comprising a mixture of water and detergent or a low boiling point solvent like acetone.

[0060] In one embodiment, the washing solution comprises from about 0.1 wt % to about 10 wt %, preferably from about 3 wt % to about 7 wt %, detergent in water. In one embodiment, the washing solution comprises water and acetone.

[0061] In one embodiment, if necessary, for example, if the removed polymer is not soluble in the polymer removing composition, the polymer separated from paper can be removed with flotation or filtration.

[0062] The resulting final, washed depolymered paper product can be used wet or dry to make a new sheet of paper or other types of cellulose-based materials.

[0063] In one embodiment, the process of the present invention further comprises the step of drying the washed depolymered paper product to provide the final depolymered paper product.

[0064] Although not required, the use of heat can speed up the drying step. In one embodiment, the step of drying takes place under vacuum. In one embodiment, the step of drying takes place under heating at a temperature of from about 60° C. to about 100° C.

[0065] In one embodiment, the drying step is carried out for a period of time of about 1 minute to about 2 hours.

[0066] In one embodiment, the degree of polymer removal of the paper product can be confirmed using FTIR methods to measure the amount of polymer layer present. The degree of water absorption of the resulting paper samples can also be measured at this stage.

[0067] The following Water Absorption Test Method is used to measure the water absorption of the paper sample. The method is based on the ASTM Standard Test Method for Rate of Water Absorption by Bibulous Papers (D 824). A test paper specimen is placed on a horizontal support centering the specimen over a 40-mm hole located in the support, ensuring that there is a gap of at least 10 mm beneath the center area of the paper specimen. Avoid stretching or distorting the test paper specimen, as this may change the results of the test. A dispensing device is filled with distilled or deionized water at 23° C.

[0068] The dispensing device is held at an angle of 30 or 45° to the horizontal with its tip nearly in contact with the central portion of the test paper specimen. Then in 6 seconds or less, a specified amount of water (1.0 mL) is dispensed onto the center of the paper specimen, while maintaining the tip of the dispensing device in contact with the water drop until delivery is completed.

[0069] The timer is started as soon as the water contacts the paper specimen and the time for the drop to be completely absorbed is measured to the nearest 0.2 seconds or better. Complete absorption is indicated by no further visual specular reflection of light (or the moment of disappearance of the glossy or shiny area from the wet spot). The maximum time course for a test is 120 seconds. Based on the time required for complete absorbance of the water, or a determination of incomplete absorbance at time 120 seconds, each sample is assigned a value from 0 to 5, where a value of 5 is assigned for a sample for which the time required for complete absorbance is similar to a paper sample without coating and a value of 1 is assigned for a sample for which the water is not completely absorbed in 120 seconds. The test is conducted under conditions that avoid heating from external sources such as a light and exposure to air currents that might influence the test.

[0070] Accordingly, the method of the present invention can be conducted under ambient temperature and pressure conditions and does not require complicated instrumentation or apparatuses.

[0071] The invention will now be described with reference to specific examples. It will be understood that the following examples are intended to describe embodiments of the invention and are not intended to limit the invention in any way.

EXAMPLES

Example 1: Removal of Release Layer with Single Solvents

[0072] Shredded silicone coated release papers (100 grams) are added to a mixing vessel containing 500 grams of a polymer removing composition containing 470 g of a solvent as identified in the first column of Table 1, 15 g of sodium dodecyl sulfate (SDS) surfactant, and 15 g of sulfuric acid (98%). All components are mixed with an overhead mixer for 50 minutes, at a temperature of 30° C. followed by centrifugation of the mixture for 5 minutes at 2000 rpm to dry the treated papers and recover the solution. In the next stage, the treated papers are washed with 500 grams of water containing detergent for 30 minutes to remove any remaining polymer removing composition and silicone residue. Filtration was carried out to remove the paper residue from the wash solution.

[0073] After the washing step is completed, and the resulting paper samples are dried, the treated paper samples are tested for water absorption using the Water Absorption Test Method described herein, and assigned a value from 1 to 5.

[0074] It is apparent from the results reported in Table 1 that some solvents result in treated papers having a higher water absorption value. It was also determined that, when the water absorption test value is below 3, an FTIR test also shows the presence of some silicon residue. However, all of these resulting samples of treated paper can be pulped for making new paper product.

[0075] All percentages used in examples are weight percentages.

TABLE-US-00001 TABLE 1 Water Acidic Washing absorption Solvent Surfactant solution solution test Xylene SDS Sulfuric acid Water + 5% 5 detergent Ethanol SDS Sulfuric acid Water + 5% 4 detergent Pyridine SDS Sulfuric acid Water + 5% 3 detergent Kerosene SDS Sulfuric acid Water + 5% 5 detergent Acetone SDS Sulfuric acid Water + 5% 4 detergent Hexane SDS Sulfuric acid Water + 5% 5 detergent Mineral Spirits SDS Sulfuric acid Water + 5% 5 detergent Cyclohexane SDS Sulfuric acid Water + 5% 3 detergent Isopropanol SDS Sulfuric acid Water + 5% 4 detergent Naphtha SDS Sulfuric acid Water + 5% 5 detergent Benzyl alcohol SDS Sulfuric acid Water + 5% 4 detergent Gasoline SDS Sulfuric acid Water + 5% 5 detergent Isoparaffin SDS Sulfuric acid Water + 5% 2 detergent Water SDS Sulfuric acid Water + 5% 2 detergent

Example 2: Removal of Release Layer with Solvent Mixtures

[0076] The polymer removal process for this example is carried out under the same steps and conditions as described in Example 1, but using the solvent mixture set out in the first column of Table 2. The test results are reported in Table 2.

TABLE-US-00002 TABLE 2 Water Acidic Washing absorption Solvent Surfactant solution solution test Xylene/Ethanol SDS Sulfuric acid Water + 5% 5 detergent Acetone/Pyridine SDS Sulfuric acid Water + 5% 5 detergent Kerosene/Gasoline SDS Sulfuric acid Water + 5% 5 detergent Mineral Spirits/ SDS Sulfuric acid Water + 5% 5 Hexane detergent Naphtha/ SDS Sulfuric acid Water + 5% 5 Isopropanol detergent Gasoline/Acetone SDS Sulfuric acid Water + 5% 5 detergent Kerosene/Gasoline/ SDS Sulfuric acid Water + 5% 5 Acetone detergent Water/Ethanol SDS Sulfuric acid Water + 5% 3 detergent

Example 3: Effectiveness of Different Surfactants

[0077] Shredded silicone coated release papers (100 grams) are added to a mixing vessel containing 500 grams of a polymer removing composition containing 470 g of kerosene, 15 g of a surfactant as identified in the second column of Table 3, and 15 g of sulfuric acid (98%). The remaining steps of the process are as carried out in Example 1. The test results are reported in Table 3.

[0078] As shown in Table 3, all of examples that employed surfactants are effective and the results of the water absorption test show very good removal of the polymer layer.

TABLE-US-00003 TABLE 3 Water Acidic Washing absorption Solvent Surfactant solution solution test Kerosene SDS Sulfuric acid Water + 5% 5 detergent Kerosene ALS Sulfuric acid Water + 5% 5 detergent Kerosene SLES Sulfuric acid Water + 5% 5 detergent Kerosene alkyl- Sulfuric acid Water + 5% 5 benzenesulfonic detergent acid Kerosene Methanesulfonic Sulfuric acid Water + 5% 5 acid (70% aqueous detergent solution) Kerosene Without surfactant Sulfuric acid Water + 5% 2 detergent Kerosene SDS/SLES (1:1 Sulfuric acid Water + 5% 5 mixture) detergent Kerosene SDS/alkyl- Sulfuric acid Water + 5% 5 benzenesulfonic detergent acid (1:1 mixture)

Example 4: Effectiveness of Different Acids

[0079] Shredded silicone coated release papers (100 grams) are added to a mixing vessel containing 500 grams of a polymer removing composition containing 470 g of kerosene, 15 g of SDS surfactant, and 15 g of an acidic solution comprising the acid as identified in the third column of Table 4. The remaining steps of the process are as carried out in Example 1. The stock acidic solutions employed in this example are sulfuric acid 98%, hydrochloric acid 37%, glacial acetic acid, nitric acid 68%, and citric acid aqueous solution (50% w/w). The test results are reported in Table 4.

TABLE-US-00004 TABLE 4 Water Acidic Washing absorption Solvent surfactant solution solution test Kerosene SDS Sulfuric acid Water + 5% 5 detergent Kerosene SDS Acetic Acid Water + 5% 4 detergent Kerosene SDS Hydrochloric Water + 5% 4 acid detergent Kerosene SDS Nitric Acid Water + 5% 3 detergent Kerosene SDS Sulfuric acid/ Water + 5% 5 Acetic Acid detergent (1:1 mixture) Kerosene SDS Sulfuric acid Water + 5% 2 detergent Kerosene SDS Sulfuric acid Water + 5% 5 detergent Kerosene SDS Sulfuric acid Water + 5% 5 detergent

Example 5: Effect of Varying Concentration of Acidic Solution

[0080] Shredded silicone coated release papers (100 grams) are added to a mixing vessel containing 500 grams of a polymer removing composition containing 15 g SDS surfactant, sulfuric acid (98%) in the amount identified in the third column in Table 5, and the balance being kerosene. The remaining steps of the process are as carried out in Example 1. The test results are reported in Table 5.

[0081] It is apparent from the water absorption test that the best results are achieved when the polymer removing composition comprised greater than 2 wt % and less than 10 wt % of sulfuric acid. More than 10 wt % resulted in a degradation and damaged to the paper fibers.

TABLE-US-00005 TABLE 5 Water Acidic Washing absorption Solvent Surfactant solution solution test Kerosene SDS Sulfuric acid Water + 5% 2 0.1% detergent Kerosene SDS Sulfuric acid Water + 5% 3 0.4% detergent Kerosene SDS Sulfuric acid Water + 5% 4 1% detergent Kerosene SDS Sulfuric acid Water + 5% 5 2% detergent Kerosene SDS Sulfuric acid Water + 5% 5 3% detergent Kerosene SDS Sulfuric acid Water + 5% 5 5% detergent Kerosene SDS Sulfuric acid Water + 5% 5 10% detergent Kerosene SDS Sulfuric acid Water + 5% 5 20% detergent

Example 6: Varying Concentration of Surfactant Solution

[0082] Shredded silicone coated release papers (100 grams) are added to a mixing vessel containing 500 grams of a polymer removing composition containing 15 g sulfuric acid (98%), SDS surfactant in the amount identified in the second column in Table 6, and the balance being kerosene. The remaining steps of the process are as carried out in Example 1. The test results are reported in Table 6.

[0083] The water absorption test shows that a polymer removing composition comprising more than 2 wt % removes the release coat well, but amounts greater than that it did not result in further improvements in removal of the release layer. Once the amount of surfactant reaches 10 wt %, the washing step becomes more difficult because of removing surfactant takes more time.

TABLE-US-00006 TABLE 6 Water Acidic Washing absorption Solvent Surfactant solution solution test Kerosene SDS 0.001% Sulfuric acid Water + 5% 2 detergent Kerosene SDS 0.4% Sulfuric acid Water + 5% 3 detergent Kerosene SDS 1% Sulfuric acid Water + 5% 4 detergent Kerosene SDS 2% Sulfuric acid Water + 5% 5 detergent Kerosene SDS 3% Sulfuric acid Water + 5% 5 detergent Kerosene SDS 5% Sulfuric acid Water + 5% 5 detergent Kerosene SDS 10% Sulfuric acid Water + 5% 5 detergent Kerosene SDS 20% Sulfuric acid Water + 5% 5 detergent

Example 7: Effect of Changing Temperature of Solution

[0084] Shredded silicone polymer coated papers (100 grams) are added to a mixing vessel containing 500 grams of a polymer removing composition containing 15 g sulfuric acid (98%), 15 g of sodium dodecyl sulfate (SDS) surfactant and the balance being the solvent identified in the first column of Table 7. The reaction temperature is varied according to the second column of Table 7. The remaining steps of the process are as carried out in Example 1. The test results are reported in Table 7.

[0085] The water absorption test shows that a polymer removing composition in kerosene is not temperature dependent but in water with increasing temperature water absorption increased and in 95° C. very good removal occurred.

TABLE-US-00007 TABLE 7 Water Temperature Acidic Washing absorption Solvent ° C. Surfactant solution solution test Kerosene 25 SDS Sulfuric Water + 5% 5 acid detergent Kerosene 30 SDS Sulfuric Water + 5% 5 acid detergent Kerosene 40 SDS Sulfuric Water + 5% 5 acid detergent Water 40 SDS Sulfuric Water + 5% 2 acid detergent Kerosene 50 SDS Sulfuric Water + 5% 5 acid detergent Kerosene 60 SDS Sulfuric Water + 5% 5 acid detergent Kerosene 70 SDS Sulfuric Water + 5% 5 acid detergent Water 70 SDS Sulfuric Water + 5% 4 acid detergent Kerosene 95 SDS Sulfuric Water + 5% 5 acid detergent Water 95 SDS Sulfuric Water + 5% 5 acid detergent

Example 8: Effect of Varying Concentration of Acidic Solution for Coffee Cup Papers

[0086] Shredded coffee cup papers (100 grams, coated with polyethylene) are added to a mixing vessel containing 500 grams of a polymer removing composition containing sulfuric acid (98%) in the amount identified in the third column in Table 8, 10 grams of sodium dodecyl sulfate (SDS) as surfactant and the balance being kerosene. Reaction temperature was set to 50° C. The remaining steps of the process are as carried out in Example 1. The test results are reported in Table 8.

[0087] It is apparent from the water absorption test that the best results are achieved when the composition comprised greater than 0.5 wt % and less than 2 wt % of sulfuric acid. More than 10 wt % resulted in a degradation and damage to the paper fibers.

TABLE-US-00008 TABLE 8 Water Acidic Washing absorption Solvent solution Surfactant solution test Kerosene Sulfuric acid SDS Water + 5% 3 0.1% detergent Kerosene Sulfuric acid SDS Water + 5% 4 0.2% detergent Kerosene Sulfuric acid SDS Water + 5% 5 0.5% detergent Kerosene Sulfuric acid SDS Water + 5% 5 1% detergent Kerosene Sulfuric acid SDS Water + 5% 5 2% detergent Kerosene Sulfuric acid SDS Water + 5% 5 5% detergent Kerosene Sulfuric acid SDS Water + 5% 5 10% detergent

Example 9: Effectiveness of Different Acids for Coffee Cup Papers

[0088] Shredded coffee cup papers (100 grams, polyethylene coated) are added to a mixing vessel containing 500 grams of a composition containing 485 g of kerosene, 10 grams of sodium dodecyl sulfate (SDS) as surfactant and 5 g of an acidic solution comprising the acid as identified in the second column of Table 9. Reaction temperature was set to 50° C. The remaining steps of the process are as carried out in Example 1. The stock acidic solutions employed in this example are sulfuric acid 98%, hydrochloric acid 37%, nitric acid 68% and glacial acetic acid. The test results are reported in Table 9.

TABLE-US-00009 TABLE 9 Water Acidic Washing absorption Solvent solution Surfactant solution test Kerosene Sulfuric acid SDS Water + 5% 5 detergent Kerosene Hydrochloric SDS Water + 5% 3 acid detergent Kerosene Nitric Acid SDS Water + 5% 3 detergent Kerosene Acetic acid SDS Water + 5% 4 detergent

[0089] It is obvious that the foregoing embodiments of the invention are examples and can be varied in many ways. Such present or future variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.