Shampoo composition and method of use

Abstract

An acidic aqueous shampoo composition, which comprises: (I) a cleansing surfactant selected from the group consisting of anionic surfactant, zwitterionic or amphoteric surfactant and nonionic surfactant; (II) an emulsified silicone, (III) an anti-settling, thickening polymer, wherein the anti-settling, thickening polymer, comprises: (a) 40 to 74.5 wt % of structural units of C.sub.1-4 alkyl acrylate; (b) 20 to 50 wt % of structural units of methacrylic acid; (c) 0.3 to <5 wt % of structural units of 2-acrylamido-2-methyl-propane sulfonic acid (AMPS); (d) 5 to 25 wt % of structural units of a specialized associated monomer having the following structure: wherein R.sup.1 is a linear saturated C.sub.10-24 alkyl group; wherein R.sup.2 is a hydrogen or a methyl group (preferably, wherein R.sup.2 is a methyl group); and wherein n is an average of 20 to 28; with the proviso that the structural units of the specialized associated monomer (d) are derived from one of (i) a single specialized associated monomer (preferably, a single specialized associated monomer wherein R.sup.1 is selected from the group consisting of a linear saturated C.sub.12 alkyl group, a linear saturated C.sub.18 alkyl group and a linear saturated C.sub.22 alkyl group; more preferably, a single specialized associated monomer wherein R.sup.1 is selected from the group consisting of a linear saturated C.sub.12 alkyl group and a linear saturated C.sub.18 alkyl group); (ii) two specialized associated monomers, wherein R.sup.1 is, respectively, a linear saturated C.sub.12 and a linear saturated C.sub.18 alkyl group; or (iii) two specialized associated monomers, wherein R.sup.1 is, respectively, a linear saturated C.sub.18 alkyl group and a linear saturated C.sub.22 alkyl group; (f) 0 to 2 wt % of structural units of multi-ethylenically unsaturated crosslinking monomer or chain transfer agent; and wherein the sum of the weight percentages of structural units (a)-(f) is equal to 100 wt % of the anti-settling, thickening polymer; and method of treating hair or scalp with such a composition. ##STR00001##

Claims

1. An acidic aqueous shampoo composition, which comprises: (I) a cleansing surfactant selected from the group consisting of anionic surfactant, zwitterionic or amphoteric surfactant, nonionic surfactant, and mixtures of any thereof; (II) an emulsified silicone; (III) an anti-settling, thickening polymer; wherein the anti-settling, thickening polymer, comprises: (a) 40 to 74.5 wt % of structural units of C.sub.1-4 alkyl acrylate; (b) 20 to 50 wt % of structural units of methacrylic acid; (c) 0.3 to <5 wt % of structural units of 2-acrylamido-2-methylpropane sulfonic acid (AMPS); (d) 5 to 25 wt % of structural units of a specialized associated monomer having the following structure: ##STR00010## wherein R.sup.1 is a linear saturated C.sub.10-24 alkyl group; wherein R.sup.2 is a hydrogen or a methyl group; and wherein n is an average of 20 to 28; with the proviso that the structural units of the specialized associated monomer (d) are derived from one of (i) a single specialized associated monomer; (ii) two specialized associated monomers, wherein R.sup.1 is, respectively, a linear saturated C.sub.12 and a linear saturated C.sub.18 alkyl group; or (iii) two specialized associated monomers, wherein R.sup.1 is, respectively, a linear saturated C.sub.18 alkyl group and a linear saturated C.sub.22 alkyl group; (e) 0 to 1 wt % of structural units of acrylic acid; and (f) 0 to 2 wt % of structural units of multi-ethylenically unsaturated crosslinking monomer and/or chain transfer agent; and wherein the sum of the weight percentages of structural units (a)-(f) is equal to 100 wt % of the anti-settling, thickening polymer.

2. The acidic aqueous shampoo composition as claimed in claim 1, wherein the anti-settling, thickening polymer includes less than 0.001 wt % of structural units of multi-ethylenically unsaturated crosslinking monomer; and wherein the anti-settling, thickening polymer includes less than 0.1 wt % of structural units of chain transfer agent.

3. The acidic aqueous shampoo composition as claimed in claim 1, wherein the anti-settling, thickening polymer has a weight average molecular weight of 25,000,000 to 300,000,000 Daltons.

4. The acidic aqueous shampoo composition as claimed in claim 1, wherein the anti-settling, thickening polymer comprises a level of AMPS of 0.5 to 3 wt %, by total weight of the polymer.

5. The acidic aqueous shampoo composition as claimed in claim 1, wherein the anti-settling, thickening polymer includes: (a) 50 to 65 wt % of structural units of C.sub.1-4 alkyl acrylate, wherein the C.sub.1-4 alkyl acrylate is ethyl acrylate; (b) 25 to 40 wt % of structural units of methacrylic acid; (c) 0.5 to 1.5 wt % of structural units of 2-acrylamido-2-methylpropane sulfonic acid (AMPS); (d) 10 to 20 wt % of structural units of the specialized associated monomer; (e) 0 to 0.1 wt % of structural units of acrylic acid; and (f) 0 to 0.001 wt % of structural units of multi-ethylenically unsaturated crosslinking monomer or chain transfer agent.

6. The acidic aqueous shampoo composition as claimed in claim 1, which has a pH of 3 to <7.

7. The acidic aqueous shampoo composition as claimed in claim 1, wherein the emulsified silicone is selected from the group consisting of polydiorganosiloxanes, silicone gums, amino functional silicones and mixtures thereof.

8. The acidic aqueous shampoo composition as claimed in claim 1, wherein the silicone is present in an amount of from 0.01 wt % to 10% wt of the total composition.

9. The acidic aqueous shampoo composition as claimed in claim 1, wherein the cleansing surfactant is selected from the group consisting of sodium lauryl sulphate, sodium lauryl ether sulphate, sodium lauryl ether sulphosuccinate, ammonium lauryl sulphate, ammonium lauryl ether sulphate, sodium cocoyl isethionate and lauryl ether carboxylic acid, coco betaine, cocamidopropyl betaine, sodium cocoamphoacetate and mixtures thereof.

10. The acidic aqueous shampoo composition as claimed in claim 1, wherein the anionic cleansing surfactant is selected from the group consisting of sodium lauryl sulphate, sodium lauryl ether sulphate (n)EO, (where n is from 1 to 3), ammonium lauryl sulphate, ammonium lauryl ether sulphate (n)EO, (where n is from 1 to 3) and mixtures thereof.

11. The acidic aqueous shampoo composition as claimed in claim 1, wherein the mixtures of any of the anionic, non-ionic and amphoteric cleansing surfactants has a ratio of primary to secondary surfactant of between 1:1-10:1, based on the inclusion weight of the cleansing surfactant in the shampoo composition.

12. The acidic aqueous shampoo composition as claimed in claim 1, wherein the cleansing surfactant is present in an amount of from 2 to 40 wt %.

13. The acidic aqueous shampoo composition as claimed in claim 1, which further comprises a pearlescer, preferably selected from the group consisting of mica, titanium dioxide, titanium dioxide coated mica, ethylene glycol distearate and mixtures thereof.

14. A method of treating hair comprising the step of applying to the hair a composition as defined by claim 1.

15. The method as claimed in claim 14 which comprises the additional step of rinsing the hair with water.

16. The acidic aqueous shampoo composition of claim 1, wherein R.sup.2 is a methyl group.

17. The acidic aqueous shampoo composition of claim 1, wherein the structural units of the specialized associated monomer (d) are derived from (i) the single specialized associated monomer wherein R.sup.1 is selected from the group consisting of a linear saturated C.sub.12 alkyl group, a linear saturated C.sub.18 alkyl group and a linear saturated C.sub.22 alkyl group.

18. The acidic aqueous shampoo composition of claim 1, wherein the structural units of the specialized associated monomer (d) are derived from (i) the single specialized associated monomer wherein R.sup.1 is selected from the group consisting of a linear saturated C.sub.12 alkyl group and a linear saturated C.sub.18 alkyl group.

19. The acidic aqueous shampoo composition as claimed in claim 1, wherein the silicone is present in an amount of from 0.1 wt % to 5 wt % of the total composition.

20. The acidic aqueous shampoo composition as claimed in claim 1, wherein the silicone is present in an amount of from 0.5 wt % to 3 wt % of the total composition.

Description

EXAMPLES

Example 1: Polymers B-L for Use in the Compositions of the Invention and Comparative Polymer a

(1) The polymers, designated Polymers B-L, for use in the compositions of the invention were prepared in accordance with formula 1. The details of Polymers A-L are given in Table 1 below, where the amount of AMPS is expressed over and above the combination of the other ingredients, in line with convention.

(2) TABLE-US-00001 TABLE 1 Structural Composition of Polymers A-L                     Sample No.                     Hydrophobe % Hydrophobe Chain Length (n) when conforming to the structure                     Ethyl Acrylate %                     Methacrylic acid %                     AMPS % A 9 12 59.5 31.5 0.25 B 9 12 59.5 31.5 0.5 C 9 12 59.5 31.5 0.75 D 9 12 59.5 31.5 1 E 9 12 59.5 31.5 1.25 F 9 12 59.5 31.5 1.5 G 16 12 52.5 31.5 1 H 20 12 48.5 31.5 1 I 16 13% 12, 3% 18 52.5 31.5 1 J 16 13% 18, 3% 22 52.5 31.5 1 K 16 8% 12, 8% 18 52.5 31.5 1 L 16 18 52.5 31.5 1
Polymers A-L were Made Using the Following General Preparation Method:

(3) A 3 liter, 4 necked round bottom flask equipped with a mechanical stirrer, thermocouple, condenser and nitrogen sparge was charged with 430 g of deionized water and 4.7 g of sodium lauryl sulfate. The flask was then purged with nitrogen and its contents were warmed to 90° C. Then a first initiator solution containing 0.33 g of ammonium persulfate dissolved in 10 g of deionized water was added to the flask. Then a monomer solution was gradually charged to the flask over a period of 107 minutes, wherein the monomer solution contained 633 g deionized water, 18 g of sodium lauryl sulfate and the amounts (as noted in TABLE 1) of each of ethyl acrylate (EA), methacrylic acid (MAA), 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and a lipophilically modified monomer (LIPO) having the following structure:

(4) ##STR00009##
wherein R.sup.1 was a linear saturated C.sub.12-14 alkyl group; R.sup.2 is selected from hydrogen or methyl(preferably, wherein R.sup.2 is a methyl group); and n was an average of 20 to 28. Starting simultaneously with the monomer solution charge, a second initiator solution containing 0.33 g of ammonium sulfate in 49 g of deionized water was gradually charged to the flask over a period of 112 minutes. Following the monomer charge and the second initiator solution charge, the transfer lines were rinsed with deionized water followed by a free radical catalyst and activator chase solution. The resulting latex products were recovered.

Example 2: Preparation of Shampoos S1-S20, in Accordance with the Invention and Comparative Shampoos, SA-SC

(5) Shampoos in accordance with the invention comprised Polymers B-L, whilst and comparative shampoos comprised Carbopol and Polymer A.

(6) Comparative shampoos SA and SC were prepared by the following method:

(7) 1. The Carbomer was thoroughly dispersed in water.

(8) 3. The cleansing surfactants, cationic polymer, mica, fragrance and preservatives were then added to the Carbomer and fully dispersed.

(9) 4. The resulting formulation was adjusted to the desired pH and viscosity using suitable pH and viscosity modifiers.

(10) Shampoos in accordance with the invention and comparative shampoo SB were prepared by the following method:

(11) 1. Polymer (Polymer (A)-(L)) was added to water.

(12) 2. The polymer was then allowed to swell by increasing the pH, using a suitable pH modifier, until a clear solution was obtained.

(13) 3. The cleansing surfactants, cationic polymer, mica, fragrance and preservatives were then added to the swollen polymer and fully dispersed.

(14) 4. The resulting formulation was adjusted to the desired pH and viscosity using suitable pH and viscosity modifiers.

(15) The compositions are shown in the following tables.

Example 3: Analytical Methods

(16) The following analytical methods were used in these examples:

(17) Silicone Deposition:

(18) Virgin hair switches were treated with the shampoo of interest. Switches were rinsed and dried before the level of silicone was quantified using x-ray fluorescence (XRF)

(19) Thermal Stability:

(20) Thermal stability was tested by placing the shampoo compositions in an oven at 45° C. for 12 weeks. The compositions were then assessed at regular time intervals over the 12 week period for sedimentation of mica particles.

(21) Viscosity:

(22) Viscosity was measured using a Brookfield RV5 spindle, at 20 rpm at 30° C.

(23) pH:

(24) pH was measured using a calibrated pH meter (pH was 4.5 unless otherwise stated)

(25) Transmission:

(26) Transmission measurements were performed on a base composition comprising 12% Sodium Laureth Sulphate, 1.6% Cocoamidopropyl Betaine and the named Polymer, that had been adjusted to neutral pH using a pH modifier. Transmission of the resulting solution was measured using a Turbiscan or similar.

Example 4: Impact of Polymer AMPS Level on Deposition of Silicone and Thermal Stability of Shampoo

(27) Shampoos were prepared, in accordance with the invention (designated S1-S5) which comprised polymers (B)-(F), having increasing amounts of AMPs (as detailed in Table 1).

(28) A Comparative Shampoo, SA, was also made, which comprised a Carbomer structurant and Comparative Shampoo SB which comprised Polymer A

(29) TABLE-US-00002 TABLE 2 Compositions of Shampoos S1-S5, in accordance with the invention and Comparative Shampoo SA and SB SA SB S1 S2 S3 S4 S5 INCI Name % w/w % w/w % w/w % w/w % w/w % w/w % w/w Aqua To 100% To 100% To 100% To 100% To 100% To 100% To 100% Carbomer 0.40 0.00 0.00 0.00 0.00 0.00 0.00 Acrylate/palmeth-25 0     0.4 (A)   0.4 (B)   0.4 (C)   0.4 (D)   0.4 (E)  0.4 (F) acrylates copolymer (polymer composition reference) Sodium Laureth 12    12    12    12    12    12    12    Sulphate Titanium Dioxide (Mica) 0.20 0.20 0.20 0.20 0.20 0.20 0.20 Cocamidopropyl 1.6  1.6  1.6  1.6  1.6  1.6  1.6  Betaine Fragrance 0.70 0.70 0.70 0.70 0.70 0.70 0.70 Guar 0.20 0.20 0.20 0.20 0.20 0.20 0.20 Hydroxypropyltrimonium Chloride Preservatives 0.55 0.55 0.55 0.55 0.55 0.55 0.55 Viscosity modifiers 0.75 0.75 0.75 0.75 0.75 0.75 0.75 pH modifiers 0.2  0.62 0.62 0.62 0.62 0.62 0.62 Dimethicone (particle 1.5  1.5  1.5  1.5  1.5  1.5  1.5  size < 10 μm)

(30) TABLE-US-00003 TABLE 2A Impact of AMPS Level on deposition of silicone and thermal stability Silicone deposition 1361 ± 276 −6 ± 35 415 ± 110 377 ± 124 465 ± 69 904 ± 108 373 ± 158 (ppm) (+/−standard deviation) Thermal storage 8-12 >12 >12 8-12 8-12 4-8 4-8 stability at 45° C. (weeks)

(31) It will be seen that as the amount of AMPS increases across shampoo 1 to shampoo 5, the amount of silicone deposition peaks at shampoo 4, which has a level of 1.25% AMPS. It will also be seen that the stability of the formulation decreases as the amount of AMPS increases, therefore the AMPS level may be tailored to achieve the right balance of silicone deposition and stability for the desired application.

Example 5: Impact of Polymer Composition on Deposition of Silicone, Transmission and Thermal Stability of Shampoo

(32) Shampoos were prepared, in accordance with the invention (designated S6-S12) which comprised polymers (D) and (G)-(L), having different structural compositions (as detailed in Table 1).

(33) Comparative Shampoo, SA, was also made, which comprised a Carbomer polymer. Transmission measurements were performed on base compositions comprising 12% Sodium Laureth Sulphate, 1.6% Cocoamidopropyl Betaine and Polymers D, G-L and Carbomer, that were adjusted to neutral pH using a pH modifier.

(34) TABLE-US-00004 TABLE 3 Compositions of Shampoos S6-S12, in accordance with the invention and Comparative Shampoo SA SA S6 S7 S8 INCI Name % w/w % w/w % w/w % w/w Aqua To To To To 100% 100% 100% 100% Carbomer 0.40 0.00 0.00 0.00 Acrylate/palmeth-25 0 0.4 (D) 0.4 (G) 0.4 (H) acrylates copolymer (polymer composition reference) Sodium Laureth Sulphate 10 10 10 10 Titanium Dioxide (Mica) 0.20 0.20 0.20 0.20 Cocamidopropyl Betaine 1.5 1.5 1.5 1.5 Fragrance 0.70 0.70 0.70 0.70 Guar Hydroxypropyl- 0.20 0.20 0.20 0.20 trimonium Chloride Preservatives 0.55 0.55 0.55 0.55 Viscosity modifiers 0.75 0.75 0.75 0.75 pH modifiers 0.2 0.62 0.62 0.62 Dimethicone (particle 0.75 0.75 0.75 0.75 size <10 μm)

(35) TABLE-US-00005 TABLE 3A Impact of Polymer Composition on deposition of silicone and thermal stability Silicone deposition (ppm) 961 ± 319 ± 367 ± 464 ± (+/−standard deviation) 192 135 97 113 Thermal storage stability at 12 4-8 4-8 4-8 45° C. (weeks) % Transmission of base 1.4 72.6 77.6 70.3 composition

(36) TABLE-US-00006 TABLE 4 Compositions of Shampoos S9-S12, in accordance with the invention and Comparative Shampoo SA SA S9 S10 S11 S12 INCI Name % w/w % w/w % w/w % w/w % w/w Aqua To To To To To 100% 100% 100% 100% 100% Carbomer 0.40 0.00 0.00 0.00 0.00 Acrylate/palmeth-25 0 0.4 (I) 0.4 (J) 0.4 (K) 0.4 (L) acrylates copolymer (polymer composition reference) Sodium Laureth Sulphate 10 10 10 10 10 Titanium Dioxide (Mica) 0.20 0.20 0.20 0.20 0.20 Cocamidopropyl Betaine 1.5 1.5 1.5 1.5 1.5 Fragrance 0.70 0.70 0.70 0.70 0.70 Guar Hydroxypropyl- 0.20 0.20 0.20 0.20 0.20 trimonium Chloride Preservatives 0.55 0.55 0.55 0.55 0.55 Viscosity modifiers 0.75 0.75 0.75 0.75 0.75 pH modifiers 0.2 0.62 0.62 0.62 0.62 Dimethicone (particle 0.75 0.75 0.75 0.75 0.75 size <10 μm)

(37) TABLE-US-00007 TABLE 4A Impact of Polymer Composition on deposition of silicone and thermal stability Silicone deposition (ppm) 961 ± 447 ± 321 ± 396 ± 325 ± (+/−standard deviation) 192 183 91 105 46 Thermal storage stability 12 8-12 8-12 8-12 8-12 at 45° C. (weeks) % Transmission of base 1.4 77.1 66.6 74.6 58.4 composition

(38) D, G, H are polymers with increasing levels of hydrophobe. It will be seen that the silicone deposition increases as the hydrophobe level increases across S6 to S8.

(39) I, J and K are polymers with mixed chain length hydrophobe chains. It will be seen that shampoos with mixed hydrophobe chain lengths, S9-S11, show improved silicone deposition performance, especially those containing a mixture of C12 and C18 hydrophobes (polymers I and K in S9 and S11, respectively) compared to when only a single chain length hydrophobe was used (polymers D and L, in S8 and S12, respectively).

(40) Additionally, it will be seen that the polymers in accordance with the present invention offer greater transmission than the carbomer in the base composition. We have found that greater transmission in a base is indicative of greater quality of appearance in the end shampoo product. The impact of the high transparency has a positive visual effect even when the insoluble ingredients are present in the composition. Whilst not transparent, the shampoo compositions comprising Polymers D and G-L have an improved visual appearance.

(41) Additionally, it will be seen the shampoos in accordance with the present invention provide a good balance of acceptable thermal stability, appearance (transmission) and silicone deposition, which is not offered by the Comparative Shampoo SA, where transmission is unacceptably low.

Example 6: Impact of SLES Ethoxylation

(42) Shampoos in accordance with the invention, S13-S16, were prepared using the Polymer (D) as given in Table 1, and the method described in Example 2.

(43) Comparative Shampoo, SC, was also made, which comprised a Carbomer structurant.

(44) Target viscosity specification: 4000-7000 cP (Brookfield RV5 spindle, 20 rpm 30° C.) Target pH: 4.5 (calibrated pH meter)

(45) TABLE-US-00008 TABLE 5 Compositions of Shampoos S13-S16, in accordance with the invention and Comparative Shampoo SC SC S13 S14 S15 S16 INCI Name % w/w % w/w % w/w % w/w % w/w Aqua To To To To To 100% 100% 100% 100% 100% Carbomer 0.40 0.00 0.00 0.00 0.00 Acrylate/palmeth-25 0 0.4 0.4 0.4 0.4 acrylates copolymer Sodium Laureth Sulphate 10 10 0 0 0 (average no. of ethoxylation units = 1) Sodium Laureth Sulphate 0 0 10 0 0 (average no. of ethoxylation units = 2) Sodium Laureth Sulphate 0 0 0 10 10 (average no. of ethoxylation units = 3) Titanium Dioxide (Mica) 0.20 0.20 0.20 0.20 0.20 Cocamidopropyl Betaine 1.5 1.5 1.5 1.5 1.5 Fragrance 0.70 0.70 0.70 0.70 0.70 Guar 0.20 0.20 0.20 0.20 0 Hydroxypropyltrimonium Chloride Hydroxyethyl Cellulose 0 0 0 0 0.20 Preservatives 0.55 0.55 0.55 0.55 0.55 Viscosity modifiers 0.75 0.75 0.75 0.75 0.75 pH modifiers 0.2 0.62 0.62 0.62 0.2

(46) TABLE-US-00009 TABLE 5A Impact of SLES Ethoxylation on Silicone Deposition Dimethicone (particle 1.5 1.5 1.5 1.5 1.5 size <10 μm) Silicone deposition 1629 ± 304 ± 612 ± 760 ± 919 ± (ppm) (+/−standard 223 74 47 219 191 deviation)

(47) It will be seen that increased levels of SLES ethoxylation give an increased level of silicone deposition with Polymer D. (Note: SC (comprising carbomer) is known to give high amount of silicone deposition. However, the appearance is of less good quality—see Table 3A).

Example 7: Impact of Shampoo pH

(48) Shampoos in accordance with the invention, S17-S20, were prepared using the Polymer (D) as given in Table 1, and the method described in Example 2.

(49) TABLE-US-00010 TABLE 6 Compositions of Shampoos S17-S20, in accordance with the invention S17 S18 S19 S20 INCI Name % w/w % w/w % w/w % w/w Aqua To To To To 100% 100% 100% 100% Acrylate/palmeth-25 0.4 0.4 0.4 0.4 acrylates copolymer Sodium Laureth Sulphate 10 10 10 10 Titanium Dioxide (Mica) 0.20 0.20 0.20 0.20 Cocamidopropyl Betaine 1.5 1.5 1.5 1.5 Fragrance 0.70 0.70 0.70 0.70 Guar Hydroxypropyl- 0.20 0.20 0.20 0.20 trimonium Chloride Preservatives 0.55 0.55 0.55 0.55 Viscosity modifiers 0.75 0.75 0.75 0.75 pH modifiers 0.62 0.62 0.62 0.62 Dimethicone (particle 0.75 0.75 1.5 1.5 size <10 μm)

(50) TABLE-US-00011 TABLE 6A Impact of shampoo pH on silicone deposition Shampoo pH 4.5 6.5 4.5 6.5 Silicone deposition (ppm) 107 ± 21 637 ± 54 132 ± 16 1247 ± 181 (+/−standard deviation)

(51) It will be seen that pH 6.5 was beneficial.

Example 8: Impact of Polymer Crosslinking on Transmission of Shampoo Base

(52) In a separate experiment, simple shampoo bases were prepared in accordance with the method described in Example 3 for measuring transmission. Mixture T1 was prepared according to the method containing 0.4% of the linear Polymer D, according to the invention, as described in Table 1. Comparative mixture TC was prepared via the same method and at the same active inclusion level (0.4%) with a commercially available cross-linked polymer, Carbopol Aqua SF2 supplied by Lubrizol. The measured transmission of the samples is provided in Table 7.

(53) TABLE-US-00012 TABLE 7 Transmission measurements of Shampoo Mixture T1, in accordance with the invention and comparative Shampoo Mixture TC Shampoo Shampoo Mixture T1 Mixture TC % Transmission of 89% 77% shampoo mixture

(54) The transmission of the composition with the linear polymer according to the present invention is higher than the commercially available cross-linked polymer.