COPOLYMER COMPRISING UNITS OF TYPE A DERIVING FROM CARBOXYLIC ACID MONOMERS AND UNITS OF TYPE B DERIVING FROM SULFONIC ACID MONOMERS

Abstract

The present invention relates to a copolymer comprising units of type A deriving from carboxylic acid monomers and units of type B deriving from sulfonic acid monomers, said units of type A and B representing more than 80 mol % of the total moles of units in the copolymer,

characterized in that it comprises at least:

one first block formed of at least 95 mol % of units of type A and having a degree of polymerization DP.sub.1 comprised between 5 and 150; and

one second block formed of at least 95 mol % of units of type A and B with a molar ratio of units of type A to units of type B greater or equal to 1, wherein said units of type A and units of type B are statistically distributed, said second block having a degree of polymerization DP.sub.2 such that DP.sub.2/DP.sub.1≥1.

It also relates to new detergent compositions comprising such a copolymer, and to the use of this copolymer in a detergent composition, especially an ADW composition, to prevent, limit or eliminate the filming phenomena.

Claims

1. A copolymer comprising units of type A deriving from carboxylic acid monomers and units of type B deriving from sulfonic acid monomers, said units of type A and B representing more than 80 mol % of the total moles of units in the copolymer, characterized in that it comprises at least: one first block formed of at least 95 mol % of units of type A and having a degree of polymerization DP.sub.1 comprised between 5 and 150; and one second block formed of at least 95 mol % of units of type A and B with a molar ratio of units of type A to units of type B being greater or equal to 1, wherein said units of type A and units of type B are statistically distributed, said second block having a degree of polymerization DP.sub.2 such that DP.sub.2/DP.sub.1≥1.

2. The copolymer according to claim 1, wherein the ratio DP.sub.2/DP.sub.1 is less than or equal to 1,000.

3. The copolymer according to claim 1 wherein the first block has a degree of polymerization DP.sub.1 greater than or equal to 10.

4. The copolymer according to claim 1 wherein the second block has a degree of polymerization DP.sub.2 less than or equal to 2,000.

5. The copolymer according to claim 1 wherein the molar ratio of units of type A to units of type B in the second block ranges from 50/50 to 90/10.

6. The copolymer according to claim 1 wherein units of type A derive from monomers selected from the group consisting of acrylic acid, methacrylic acid, ethacrylic acid, alpha-chloro-acrylic acid, bromo acrylic acid, bromomethyl acrylic acid, alpha-cyano acrylic acid, beta methyl-acrylic acid, alpha-phenyl acrylic acid, beta-acryloxy propionic acid, beta-carboxyethyl acrylic acid, sorbic acid, alpha-chloro sorbic acid, angelic acid, cinnamic acid, p-chloro cinnamic acid, beta-styryl acrylic acid, itaconic acid, maleic acid, citraconic acid, mesaconic acid, glutaconic acid, aconitic acid, fumaric acid, vinyl benzoic acid, pentenic acid, propyl acrylic acid, acetamido acrylic acid, maleimido propyl carboxylic acid and mixtures thereof.

7. The copolymer according to claim 1 wherein said units of type A of the first block are identical to said units of type A of the second block.

8. The copolymer according to claim 1 wherein units of type A of the first block and/or the second block derive from acrylic acid monomer.

9. The copolymer according to claim 1 wherein units of type B derive from monomers selected from the group consisting of acrylamido-2-methylpropanesulfonic acid, 2-methacrylamido-2-methylpropanesulfonic acid, 3-methyacrylamido-2-hydroxypropanesulfonic acid, (meth)allylsulfonic acid, 1-allyloxy-2-hydroxypropane sulfonic acid, allyloxybenzene sulfonic acid, (meth)allyloxybenzensulfonic acid, 2-hydroxy-3-(2-propenyloxy)propanesulfonic acid, 2-methyl-2-propene-1-sulfonic acid, styrene sulfonic acid, vinylsulfonic acid, 3-sulfopropyl acrylate, 3-sulfopropyl methacrylate, sulfomethylacrylamid, sulfomethylmethacrylamid, water soluble salts thereof, and mixtures thereof.

10. The copolymer according to claim 1 wherein units of type B derive from 2-acrylamido-2-methylpropanesulfonate monomer or sodium vinyl sulfonate monomer.

11. The copolymer according to claim 1 wherein said units of type A derive from acrylic acid monomer and said units of type B derive from 2-acrylamido-2-methylpropanesulfonate monomer.

12. The copolymer according to claim 1 comprises a diblock copolymer consisting of one first block and one second block as defined in claim 1.

13. The copolymer according to claim 1 wherein said diblock copolymer consists of: one first block deriving from acrylic acid monomers with a degree of polymerization DP.sub.1 comprised around 60; and one second block that is a statistical block deriving from acrylic acid (AA) and 2-acrylamido-2-methylpropanesulfonate (AMPS) monomers with a molar ratio of AA units to AMPS units comprised between 50/50 and 80/20, said second block having a degree of polymerization DP2 comprised between 50 and 250.

14. A detergent composition comprising at least one copolymer according to claim 1.

15. The copolymer according to claim 1, wherein said composition comprises from 0.001 to 10% by weight of said copolymer in respect to the total weight of the composition.

16. A method of preventing, limiting or eliminating filming phenomena comprising adding to at least one copolymer according to claim 1 a detergent composition, wherein the detergent composition is an automatic dishwashing detergent composition.

17. A diblock copolymer pAA-b-(pAA/AMPS 75/25) comprising units of type A deriving from acrylic acid monomers and units of type B deriving from acrylic acid and 2-acrylamido-2-methylpropane sulfonate monomers with a molar ratio of type A units to type B units of 50/50.

18. The copolymer according to claim 17, wherein the second block has a degree of polymerization DP.sub.2 between 60 and 80.

Description

EXAMPLES

[0332] In the following examples 1 to 8, determination of the weight average molar mass (M.sub.w) and number average molar mass (M.sub.n) of the macromolecular distributions of the (co)polymers was performed by GPC-MALS Gel Permeation chromatography—MultiAngle Light Scattering.

[0333] The elution conditions were the following: [0334] Mobile phase: Deionised water, NaCl 100 mM, NaH.sub.2PO.sub.4 25 mM, [0335] Na.sub.2HPO.sub.4 25 mM. [0336] Flow rate: 1 ml/min [0337] Columns: Varian Aquagel mixed 8 (3 colmuns×30 cm) [0338] Detection: Refractive Index (Agilent concentration detector)+MALS (Treos Minidawn) [0339] Sample concentration: around 0.5% by weight of dry matter in the mobile phase [0340] Injection loop: 100 μl [0341] Dn/dc: 0.15.

[0342] Residual monomers were measured by high-performance liquid chromatography (HPLC).

EXAMPLE 1

[0343] Synthesis of the Polymer PAA (DPn 60; Mn.sub.th 4533 g/Mol)

[0344] Into a 1L double jacketed reactor equipped with mechanical agitator and reflux condenser was added 6.25 g of O-ethyl-S-(1-methoxycarbonylethyl)xanthate (CH.sub.3CH(CO.sub.2CH.sub.3))S(C═S)OEt), 56.4 g of Ethanol, and 225.7 g of De-ionised water and 19.5 g of acrylic acid. The reactor contents were heated to 70° C. under agitation whereupon 13.2 g of a solution of 10 wt % V-50 (2,2′-Azobis(2-methylpropionamidine) dihydrochloride) was added in 1 shot. Immediately thereafter, a feed of 110.3 g of acrylic acid was added to the reactor over 3 h by means of a syringe pump. At the same time 39.7 g of a solution of 10 wt % V50 was added over 3 h10 minutes by means of a syringe pump. Once the initiator feed had ended, the reaction mixture was aged at 70° C. for a further hour whereupon it was cooled to ambient temperature and discharged. The pH of the reaction mixture was then adjusted to 2.5 using a 50% wt solution of NaOH. The ethanol was stripped from the reaction mixture by distillation using a rotary evaporator (Bath temperature 50° C., 120-50 mbar) and deionized water back added to keep the polymer concentration constant (around 30%). The measured solids content was 31.3% (115° C., 60 mins).

[0345] Dexanthation

[0346] 50 g of polymer solution was placed in a 250 ml 2 necked round bottomed flask equipped with a magnetic stirrer bar. The pH of the solution was increased to 8.5 using a 50% solution of NaOH. The mixture was heated to 70° C. with stirring whereupon 1.17 g of a 30% solution of hydrogen peroxide was added in 1 shot. After 15 minutes, a further 1.17 g shot of hydrogen peroxide (30%) was added. The addition was repeated at 30 minutes and at 45 minutes. At the end of the additions, the solution was aged for a further 3 h45 whereupon it was cooled and discharged. Dexanthation was confirmed using GPC analysis equipped with RI and UV (290 nm) detection.

[0347] The weight average molar mass was 4773 g/mol and number average molar mass as measured by the GPC technique described above was 3912 g/mol. The residual acrylic acid as measured by HPLC was <10 ppm.

EXAMPLE 2

[0348] Synthesis of the Copolymer PAA-b-(AA-Stat-AMPS) (DPn 60-60; Ratio AA/AMPS 75/25 Mol %)

[0349] i. Synthesis of the first block PAA (DPn 60)

[0350] Into a 1 L double jacketed reactor equipped with mechanical agitator and reflux condenser was added 6.25 g of O-ethyl-S-(1-methoxycarbonylethyl)xanthate (CH.sub.3CH(CO.sub.2CH.sub.3))S(C=S)OEt), 19.46 g of Acrylic acid, 56.4 g of Ethanol, and 225.7 g of De-ionised water. The reactor contents were heated to 70° C. under agitation whereupon 13 g of a solution of 10 wt % V-50 (2,2′-Azobis(2-methylpropionamidine) dihydrochloride) was added in 1 shot. Immediately thereafter, a feed of 110 g of acrylic acid was added to the reactor over 3 h by means of a syringe pump. At the same time 39.7 g of a solution of 10% wt V50 was added over 3 h10 minutes by means of a syringe pump. Once the initiator feed had ended, the reaction mixture was aged at 70° C. for a further hour whereupon it was cooled to ambient temperature and discharged. The pH of the reaction mixture was then adjusted to 2.5 using a 50% wt solution of NaOH. The ethanol was stripped from the reaction mixture by distillation using a rotary evaporator (Bath temperature 50° C., 120-50 mbar) and deionized water back added to keep the polymer concentration constant (around 30%). The measured solids content was 31.3% (115° C., 60 mins).

[0351] ii. Synthesis of the Second Block AA-s-AMPS (DPn 60; Ratio AA/AMPS 75/25 Mol %)

[0352] Into a 500 mL double jacketed reactor equipped with mechanical agitator and reflux condenser was added 126.3 g of a 31.3% solution of the 1.sup.st block, 4.05 g of Acrylic acid, 8.6 g of a 50% solution of 2-Acrylamido-2-methylpropane sulfonic acid (AMPS), and 47.8 g of De-ionised water. The reactor contents were heated to 75° C. under agitation whereupon 9.6 g of a solution of 10 wt % sodium persulphate (NaPS) was added in 1 shot. Immediately thereafter, a feed of 22.95 g of acrylic acid was added to the reactor over 2 h by means of a syringe pump. At the same time 48.71 g of a 50% solution of AMPS added over 2 h by means of a syringe pump. Once the monomer feeds had ended further 9.6 g of a 10% solution of NaPS were added to the reactor and the reaction mixture was aged at 75° C. for a further 4 hours whereupon it was cooled to ambient temperature and discharged. The measured solids content was 38.65% (115° C., 60 mins).

[0353] 150 g of polymer solution was placed in a 250 ml 2 necked round bottomed flask equipped with a magnetic stirrer bar. The pH of the solution was increased to 8.5 using a 50% solution of NaOH. The mixture was heated to 70° C. with stirring whereupon 1.84 g of a 30% solution of hydrogen peroxide was added in 1 shot. After 15 minutes, a further 1.84 g shot of hydrogen peroxide (30%) was added. The addition was repeated at 30 minutes and at 45 minutes. At the end of the additions, the solution was aged for a further 3 h45 whereupon it was cooled and discharged. Dexanthation was confirmed using GPC analysis equipped with RI and UV (290 nm) detection.

[0354] The weight average molar mass was 20720 g/mol and number average molar mass as measured by the GPC technique described above was 10170 g/mol. The residual acrylic acid as measured by HPLC was <10 ppm and the residual AMPS monomer was <20 ppm. The solids content was 34.5% (100° C., 60 minutes).

EXAMPLE 3

[0355] Synthesis of the copolymer PAA-b-(AA-stat-AMPS) (DPn 60-200; ratio AA/AMPS 75/25 mol %)

[0356] i. Synthesis of the first block PAA (DPn 60)

[0357] Into a 500 mL double jacketed reactor equipped with mechanical agitator and reflux condenser was added 7.7 g of O-ethyl-S-(1-methoxycarbonylethyl)xanthate (CH.sub.3CH(CO.sub.2CH.sub.3))S(C═S)OEt), 38.9 g of Ethanol, and 38.9 g of De-ionised water. The reactor contents were heated to 70° C. under agitation whereupon 12.54 g of a solution of 5 wt % V-50 (2,2′-Azobis(2-methylpropionamidine) dihydrochloride) was added in 1 shot. Immediately thereafter, a feed of 345.4 g of a solution of 46.3 wt % acrylic acid was added to the reactor over 3 h by means of a syringe pump. At the same time 50.0 g of a solution of 3.7 wt % V50 was added over 3 h10 minutes by means of a syringe pump. Once the initiator feed had ended, the reaction mixture was aged at 70° C. for a further hour whereupon it was cooled to ambient temperature and discharged. The pH of the reaction mixture was then adjusted to 2.5 using a 50% wt solution of NaOH. The ethanol was stripped from the reaction mixture by distillation using a rotary evaporator (Bath temperature 50° C., 120-50 mbar) and deionized water back added to keep the polymer concentration constant (around 35%). The measured solids content was 38.6% (115° C., 60 mins).

[0358] ii. Synthesis of the second block AA-s-AMPS (DPn 200; ratio AA/AMPS 75/25 mol %)

[0359] Into a 500 mL double jacketed reactor equipped with mechanical agitator and reflux condenser was added 81.6 g of a 38.6% solution of the 1.sup.st block, 9.72 g of Acrylic acid, 20.63 g of a 50% solution of 2-Acrylamido-2-methylpropane sulfonic acid (AMPS), and 173.3 g of De-ionised water. The reactor contents were heated to 75° C. under agitation whereupon 10.2 g of a solution of 10 wt % sodium persulphate (NaPS) was added in 1 shot. Immediately thereafter, a feed of 55.1 g of acrylic acid was added to the reactor over 2 h by means of a syringe pump. At the same time 116.9 g of a 50% solution of AMPS added over 2 h by means of a syringe pump. Once the monomer feeds had ended further 10.2 g of a 10% solution of NaPS were added to the reactor and the reaction mixture was aged at 75° C. for a further 4 hours whereupon it was cooled to ambient temperature and discharged. The measured solids content was 38.9% (115° C., 60 mins).

[0360] 552 g of polymer solution was placed in a 1 L 2 necked round bottomed flask equipped with a magnetic stirrer bar. The pH of the solution was increased to 8,5 using a 50% solution of NaOH. The mixture was heated to 70° C. with stirring whereupon 2.65 g of a 30% solution of hydrogen peroxide was added in 1 shot. After 15 minutes, a further 2.65 g shot of hydrogen peroxide (30%) was added. The addition was repeated at 30 minutes and at 45 minutes. At the end of the additions, the solution was aged for a further 3 h45 whereupon it was cooled and discharged. Dexanthation was confirmed using GPC analysis equipped with RI and UV (290 nm) detection.

[0361] The weight average molar mass was 57250 g/mol and number average molar mass as measured by the GPC technique described above was 25450 g/mol. The residual acrylic acid as measured by HPLC was <10 ppm and the residual AMPS monomer was <20 ppm. The solids content was 42.2% (100° C., 60 minutes).

EXAMPLE 4 (OUTSIDE THE INVENTION)

[0362] Synthesis of the copolymer PAA-b-(AA-stat-AMPS) (DPn 200-28); ratio AA/AMPS 75/25 mol %)

[0363] i. Synthesis of the first block PAA (DPn 200)

[0364] Into a 500 mL double jacketed reactor equipped with mechanical agitator and reflux condenser was added 2.3 g of O-ethyl-S-(1-methoxycarbonylethyl)xanthate (CH.sub.3CH(CO.sub.2CH.sub.3))S(C═S)OEt), 11.67 g of Ethanol, and 11.67 g of De-ionised water. The reactor contents were heated to 70° C. under agitation whereupon 7.5 g of a solution of 5 wt % V-50 (2,2′-Azobis(2-methylpropionamidine) dihydrochloride) was added in 1 shot. Immediately thereafter, a feed of 389.2 g of a solution of 69.8 wt % acrylic acid was added to the reactor over 3 h by means of a syringe pump. At the same time 50.0 g of a solution of 3.7 wt % V50 was added over 3 h10 minutes by means of a syringe pump. Once the initiator feed had ended, the reaction mixture was aged at 70° C. for a further hour whereupon it was cooled to ambient temperature and discharged. The pH of the reaction mixture was then adjusted to 2.5 using a 50% wt solution of NaOH. The ethanol was stripped from the reaction mixture by distillation using a rotary evaporator (Bath temperature 50° C., 120-50 mbar) and deionized water back added to keep the polymer concentration constant (around 35%). The measured solids content was 37.6% (115° C., 60 mins).

[0365] ii. Synthesis of the second block AA-s-AMPS (DPn 28;ratio 75/25 mol %)

[0366] Into a 500 mL double jacketed reactor equipped with mechanical agitator and reflux condenser was added 290.4 g of a 37.6% solution of the 1.sup.st block, 1.3 g of Acrylic acid, 2.75 g of a 50% solution of 2-Acrylamido-2-methylpropane sulfonic acid (AMPS), and 36.0 g of De-ionised water. The reactor contents were heated to 75° C. under agitation whereupon 6.6 g of a solution of 10 wt % sodium persulphate (NaPS) was added in 1 shot. Immediately thereafter, a feed of 7.3 g of acrylic acid was added to the reactor over 2 h by means of a syringe pump. At the same time 15.6 g of a 50% solution of AMPS added over 2 h by means of a syringe pump. Once the monomer feeds had ended further 6.6 g of a 10% solution of NaPS were added to the reactor and the reaction mixture was aged at 75° C. for a further 4 hours whereupon it was cooled to ambient temperature and discharged. The measured solids content was 36% (115° C., 60 mins).

[0367] 366 g of polymer solution was placed in a 1 L 2 necked round bottomed flask equipped with a magnetic stirrer bar. The pH of the solution was increased to 8.5 using a 50% solution of NaOH. The mixture was heated to 70° C. with stirring whereupon 2.02 g of a 30% solution of hydrogen peroxide was added in 1 shot. After 15 minutes, a further 2.02 g shot of hydrogen peroxide (30%) was added. The addition was repeated at 30 minutes and at 45 minutes. At the end of the additions, the solution was aged for a further 3 h45 whereupon it was cooled and discharged. Dexanthation was confirmed using GPC analysis equipped with RI and UV (290 nm) detection.

[0368] The weight average molar mass was 26410 g/mol and number average molar mass as measured by the GPC technique described above was 17770 g/mol. The residual acrylic acid as measured by HPLC was <10 ppm and the residual AMPS monomer was <20 ppm. The solids content was 42.2% (100° C., 60 minutes).

EXAMPLE 5

[0369] Synthesis of the copolymer PAA-b-(AA-stat-SVS) DPn 60-60); ratio AA/SVS 75/25 mol %)

[0370] i. Synthesis of the first block PAA (DPn 60)

[0371] Into a 1 L double jacketed reactor equipped with mechanical agitator and reflux condenser was added 7.7 g of O-ethyl-S-(1-methoxycarbonylethyl)xanthate (CH.sub.3CH(CO.sub.2CH.sub.3))S(C=S)OEt), 24.1 g of Acrylic acid, 55.4 g of Ethanol, and 221.5 g of De-ionised water. The reactor contents were heated to 70° C. under agitation whereupon 12.6 g of a solution of 10 wt % V-50 (2,2′-Azobis(2-methylpropionamidine) dihydrochloride) was added in 1 shot. Immediately thereafter, a feed of 136.6 g of acrylic acid was added to the reactor over 3 h by means of a syringe pump. At the same time 37.8 g of a solution of 10% wt V50 was added over 3 h10 minutes by means of a syringe pump. Once the initiator feed had ended, the reaction mixture was aged at 70° C. for a further hour whereupon it was cooled to ambient temperature and discharged. The pH of the reaction mixture was then adjusted to 2.5 pH using a 50% wt solution of NaOH. The ethanol was stripped from the reaction mixture by distillation using a rotary evaporator (Bath temperature 50° C., 120-50 mbar) and deionized water back added to keep the polymer concentration constant (around 35%). The measured solids content was 37.2% (115° C., 60 mins).

[0372] ii. Synthesis of the second block AA-s-SVS (DPn 60; ratio AA/SVS 75/25 mol %)

[0373] Into a 500 mL double jacketed reactor equipped with mechanical agitator and reflux condenser was added 206.7 g of a 37.2% solution of the 1.sup.st block, 5.7 g of Acrylic acid, 13.7 g of a 25% solution of Vinylsulfonic Acid Sodium Salt (SVS), and 57.6 g of De-ionised water. The reactor contents were heated to 70° C. under agitation whereupon 6.17 g of a solution of 10 wt % V50 (2,2′-Azobis(2-methylpropionamidine) dihydrochloride) was added in 1 shot. Immediately thereafter, a feed of 51.1 g of acrylic acid was added to the reactor over 6 h by means of a syringe pump. At the same time 122.9 g of a 25% solution of SVS was added over 6 h by means of a syringe pump and 24.7 g of a solution of 10 wt % V50 (2,2′-Azobis(2-methylpropionamidine) dihydrochloride) was added over 6 h30 by means of a syringe pump. Once the monomer feeds had ended the reaction mixture was aged at 70° C. for a further 2 hours whereupon it was cooled to ambient temperature and discharged. The measured solids content was 38.9% (115° C., 60 mins).

[0374] 450 g of polymer solution was placed in a 1 L 2 necked round bottomed flask equipped with a magnetic stirrer bar. The pH of the solution was increased to 8.5 using a 50% solution of NaOH. The mixture was heated to 70° C. with stirring whereupon 6.3 g of a 30% solution of hydrogen peroxide was added in 1 shot. After 15 minutes, a further 6.3 g shot of hydrogen peroxide (30%) was added. The addition was repeated at 30 minutes and at 45 minutes. At the end of the additions, the solution was aged for a further 3 h45 whereupon it was cooled and discharged. Dexanthation was confirmed using GPC analysis equipped with RI and UV (290 nm) detection.

[0375] The weight average molar mass was 11420 g/mol and number average molar mass as measured by the GPC technique described above was 7599 g/mol. The residual acrylic acid as measured by HPLC was 232. The solids content was 36.1% (100° C., 60 minutes).

EXAMPLE 6 (OUTSIDE THE INVENTION)

[0376] Synthesis of the copolymer PAA-stat-AMPS (DPn 60; ratio AA/AMPS 75/25 mol %)

[0377] Into a 500 ml double jacketed reactor equipped with mechanical agitator and reflux condenser was added 2.8 g of O-ethyl-S-(1-methoxycarbonylethyl)xanthate (CH.sub.3CH(CO.sub.2CH.sub.3))S(C═S)OEt), 12.6 g of Ethanol, and 12.6 g of De-ionised water. The reactor contents were heated to 70° C. under agitation whereupon 5.95 g of a solution of 10 wt % V-50 (2,2′-Azobis(2-methylpropionamidine) dihydrochloride) was added in 1 shot. Immediately thereafter, a feed of a mixture of 46 g of acrylic acid and 97.5 g of 50 wt % 2-Acrylamido-2-methylpropane sulfonic acid (AMPS) and 105.6 g of De-ionised water was added to the reactor over 3 h by means of a syringe pump. At the same time 17.9 g of a solution of 10% wt V50 diluted in 32.1 g of De-ionised water was added over 3 h10 minutes by means of a syringe pump. Once the initiator feed had ended, the reaction mixture was aged at 70° C. for a further hour whereupon it was cooled to ambient temperature and discharged. The pH of the reaction mixture was then adjusted to 2.5 pH using a 50% wt solution of NaOH. The ethanol was stripped from the reaction mixture by distillation using a rotary evaporator (Bath temperature 50° C., 120-50 mbar) and deionized water back added to keep the polymer concentration constant (around 30%). The measured solids content was 32.2% (115° C., 60 mins).

[0378] 100 g of polymer solution was placed in a 250 ml 2 necked round bottomed flask equipped with a magnetic stirrer bar. The pH of the solution was increased to 8.5 using a 50% solution of NaOH. The mixture was heated to 70° C. with stirring whereupon 1.3 g of a 30% solution of hydrogen peroxide was added in 1 shot. After 15 minutes, a further 1.3 g shot of hydrogen peroxide (30%) was added. The addition was repeated at 30 minutes and at 45 minutes. At the end of the additions, the solution was aged for a further 3 h45 whereupon it was cooled and discharged. Dexanthation was confirmed using

[0379] GPC analysis equipped with RI and UV (290 nm) detection.

[0380] The weight average molar mass was 8378 g/mol and number average molar mass as measured by the GPC technique described above was 5389 g/mol. The residual acrylic acid as measured by HPLC was <10 ppm and the residual AMPS monomer was <20 ppm. The solids content was 34.5% (115° C., 60 minutes)

EXAMPLE 7

[0381] Synthesis of the copolymer PAA-b-(AA-stat-AMPS) (DPn 60-60; ratio AA/AMPS 50/50 mol %)

[0382] i. Synthesis of the first block PAA (DPn 60, Mn.sub.th 4533 g/mol)

[0383] Into a 500 mL double jacketed reactor equipped with mechanical agitator and reflux condenser was added 6.3 g of O-ethyl-S-(1-methoxycarbonylethyl)xanthate (CH.sub.3CH(CO.sub.2CH.sub.3))S(C═S)OEt), 56.4 g of Ethanol, and 225.7 g of De-ionised water and 19.5 g of acrylic acid. The reactor contents were heated to 70° C. under agitation whereupon 13.2 g of a solution of 10 wt % V-50 (2,2′-Azobis(2-methylpropionamidine) dihydrochloride) was added in 1 shot. Immediately thereafter, a feed of 110.3 g of acrylic acid was added to the reactor over 3 h by means of a syringe pump. At the same time 39.7 g of a solution of 10 wt % V50 was added over 3 h10 minutes by means of a syringe pump. Once the initiator feed had ended, the reaction mixture was aged at 70° C. for a further hour whereupon it was cooled to ambient temperature and discharged. The pH of the reaction mixture was then adjusted to 2.5 using a 50% wt solution of NaOH. The ethanol was stripped from the reaction mixture by distillation using a rotary evaporator (Bath temperature 50° C., 120-50 mbar) and deionized water back added to keep the polymer concentration constant (around 30%). The measured solids content was 31.3% (115° C., 60 mins).

[0384] ii. Synthesis of the second block AA-s-AMPS (DPn 60; ratio AA/AMPS 50/50 mol %)

[0385] Into a 500 mL double jacketed reactor equipped with mechanical agitator and reflux condenser was added 151.6 g of a 31.3% solution of the 1.sup.st block, 3.24 g of Acrylic acid, 20.6 g of a 50% solution of 2-Acrylamido-2-methylpropane sulfonic acid (AMPS), and 25.3 g of De-ionized water. The reactor contents were heated to 75° C. under agitation whereupon 5.7 g of a solution of 10 wt % sodium persulphate (NaPS) was added in 1 shot. Immediately thereafter, a feed of 18.4 g of acrylic acid was added to the reactor over 2 h by means of a syringe pump. At the same time 116.9 g of a 50% solution of AMPS added over 2 h by means of a syringe pump. Once the monomer feeds had ended further 5.7 g of a 10% solution of NaPS were added to the reactor and the reaction mixture was aged at 75° C. for a further 4 hours whereupon it was cooled to ambient temperature and discharged. The measured solids content was 44.7% (115° C., 60 mins).

[0386] 150 g of polymer solution was placed in a 500 ml 2 necked round bottomed flask equipped with a magnetic stirrer bar. The pH of the solution was increased to 8.5 using a 50% solution of NaOH. The mixture was heated to 70° C. with stirring whereupon 1.8 g of a 30% solution of hydrogen peroxide was added in 1 shot. After 15 minutes, a further 1.8 g shot of hydrogen peroxide (30%) was added. The addition was repeated at 30 minutes and at 45 minutes. At the end of the additions, the solution was aged for a further 3 h45 whereupon it was cooled and discharged. Dexanthation was confirmed using GPC analysis equipped with RI and UV (290 nm) detection.

[0387] The weight average molar mass was 19430 g/mol and number average molar mass as measured by the GPC technique described above was 13040 g/mol. The residual acrylic acid as measured by HPLC was <10 ppm and the residual AMPS monomer was <20 ppm. The solids content was 38% (115° C., 60 minutes).

EXAMPLE 8

[0388] Synthesis of the copolymer PAA-b-(AA-stat-AMPS) (DPn 60-80; ratio AA/AMPS 50/50 mol %)

[0389] i. Synthesis of the first block PAA (DPn 60, Mn.sub.th 4533 g/mol)

[0390] Into a 500 mL double jacketed reactor equipped with mechanical agitator and reflux condenser was added 6.3 g of O-ethyl-S-(1-methoxycarbonylethyl)xanthate (CH.sub.3CH(CO.sub.2CH.sub.3))S(C=S)OEt), 56.4 g of Ethanol, and 225.7 g of De-ionised water and 19.46 g of acrylic acid. The reactor contents were heated to 70° C. under agitation whereupon 13.2 g of a solution of 10 wt % V-50 (2,2′-Azobis(2-methylpropionamidine) dihydrochloride) was added in 1 shot. Immediately thereafter, a feed of 110.3 g of acrylic acid was added to the reactor over 3 h by means of a syringe pump. At the same time 39.7 g of a solution of 10 wt % V50 was added over 3 h10 minutes by means of a syringe pump. Once the initiator feed had ended, the reaction mixture was aged at 70° C. for a further hour whereupon it was cooled to ambient temperature and discharged. The pH of the reaction mixture was then adjusted to 2.5 using a 50% wt solution of NaOH. The ethanol was stripped from the reaction mixture by distillation using a rotary evaporator (Bath temperature 50° C., 120-50 mbar) and deionized water back added to keep the polymer concentration constant (around 30%). The measured solids content was 31.3% (115° C., 60 mins).

[0391] ii. Synthesis of the second block AA-s-AMPS (DPn 80; ratio AA/AMPS 50/50 mol %)

[0392] Into a 500 mL double jacketed reactor equipped with mechanical agitator and reflux condenser was added 113.7 g of a 31.3% solution of the 1.sup.st block, 3.24 g of Acrylic acid, 20.6 g of a 50% solution of 2-Acrylamido-2-methylpropane sulfonic acid (AMPS), and 80.93 g of De-ionized water. The reactor contents were heated to 75° C. under agitation whereupon 4.3 g of a solution of 10 wt % sodium persulphate (NaPS) was added in 1 shot. Immediately thereafter, a feed of 18.4 g of acrylic acid was added to the reactor over 2 h by means of a syringe pump. At the same time 116.9 g of a 50% solution of AMPS added over 2 h by means of a syringe pump. Once the monomer feeds had ended further 4.3 g of a 10% solution of NaPS were added to the reactor and the reaction mixture was aged at 75° C. for a further 4 hours whereupon it was cooled to ambient temperature and discharged. The measured solids content was 38.2% (115° C., 60 mins). 156.8 g of polymer solution was placed in a 500 ml 2 necked round bottomed flask equipped with a magnetic stirrer bar. The pH of the solution was increased to 8.5 using a 50% solution of NaOH. The mixture was heated to 70° C. with stirring whereupon 1.2 g of a 30% solution of hydrogen peroxide was added in 1 shot. After 15 minutes, a further 1.2 g shot of hydrogen peroxide (30%) was added. The addition was repeated at 30 minutes and at 45 minutes. At the end of the additions, the solution was aged for a further 3 h45 whereupon it was cooled and discharged. Dexanthation was confirmed using GPC analysis equipped with RI and UV (290 nm) detection.

[0393] The weight average molar mass was 28050 g/mol and number average molar mass as measured by the GPC technique described above was 18340 g/mol. The residual acrylic acid as measured by HPLC was <10 ppm and the residual AMPS monomer was <20 ppm. The solids content was 38% (115° C., 60 minutes).

EXAMPLE 9

[0394] Performance of the copolymer of the invention in an ADW composition

[0395] Different (co)polymers (see table 1 below) were tested for their anti-filming effect for the washing of two glasses in an automatic dishwasher.

[0396] Test of anti-filming effect

[0397] Glass should be perfectly clean before testing. The glasses (sold by CHOMETTE FAVOR under the reference Islande 33 cL) are initially cleaned with a high alkaline detergent, which is a blend of 55% of sodium tri-polyphosphate (STPP) and 45% of sodium metasilicate. Then, glasses are cleaned with citric acid to remove the alkalinity.

[0398] Each glass should be checked under a light box that it is completely free of spot and film before use.

[0399] After this prewashing, the filming of the clean glasses is evaluated at 8, using a 1-10 scale in which 1 is completely covered with heavy chalky film and 10 is clear (Depending on the composition or the thickness, other glasses could be more transparent than these glasses and achieve a filming at 10).

[0400] Then, two clean glasses are placed on the upper rack of a Miele G 646 SC Plus Prima automatic dishwasher.

[0401] Three ADW cycles are run for an evaluation, with the introduction of 50 g of frozen soil and 20 g of detergent at each cycle at 55° C.

[0402] The soil consists in weight percentage of 70% water, 5% milk, 2.5% mustard, 2.5% ketchup, 2.5% gravy, 0.5% potato starch, 0.4% benzoic acid, 10% margarine, 5% egg yolk.

[0403] A Normal wash program consists of a 55° C. main wash followed by two heated rinses (65° C.) and a heated dry cycle. Water Hardness was adjusted to 35° TH. This water contains molar ratio of Ca:Mg of 3:1 (as salts used are CaCl.sub.2*2H.sub.2O and MgSO.sub.4*7H.sub.2O) and 400 mg/L NaHCO.sub.3.

[0404] The different (co)polymers (see table 1 below) are tested in liquid form and added five minutes later than a commercial formulation that is, in the present example, detergent P-free tablet sold under the name Finish Quantum from the United States market.

[0405] The concentration of (co)polymer or blend of (co)polymers is 5% by weight of the total blend. 20.0 g of detergent are dosed via the dispenser cup of the automatic dishwasher.

[0406] After completion of the three wash programs, the appearance of the washed glassware was assessed visually using a light box, method inspired by ASTM Method D3556 85. The light box is essentially a darkened room with the glasses being placed on racks and illuminated from within to disclose spots or film. All interior surfaces of the light box are black, so that the only light present is that which passes up through the tumblers.

[0407] Washed glasses were scored (see Table 1 below, column “Filming”) using the 1-10 scale in which 1 is completely covered with heavy chalky film and 10 is clear.

[0408] Results

[0409] The results are recorded in Table 1 below.

TABLE-US-00001 TABLE 1 Polymers used Chemistry Filming Control (no additives) 3 Acusol 587 D from Statistical AA/AMPS 80/20 3-4 Dow Mw = 18700 g/mol 5% active/tab Homopolymer pAA 3 (example 1) DPn = 60 5% active/tab Statistical copolymer pAA/AMPS 75/25 3-4 (example 6) DPn = 60 5% active/tab Diblock copolymer pAA-b-(pAA/AMPS 75/25) 4-5 (according to the DPn = 60-60 invention) 5% active/tab (example 2) Blend of Homopolymer pAA 3-4 (example 1) and DPn = 60 statistical copolymer 2.1% act/tab (example 6) and pAA/AMPS 75/25 DPn = 60 2.9% act/tab

[0410] This example clearly demonstrates the ability of the copolymer of the invention (i.e. PAA-b-P(AA-s-AMPS 75/25)) to deliver glass appearance benefits superior to those of the current statistical copolymers or homopolymers or a blend of them. The copolymer of the invention clearly provides an anti-filming effect superior to any that may be provided by the current antiscalant polymers.

EXAMPLE 10

[0411] The anti-filming performance of a diblock copolymer of the invention is compared to the performances of other diblock copolymers that do not comply with the specificities of the invention.

[0412] The protocol for testing anti-filming effect is the same as described in previous example 9 (see Table 2 below, column “Filming”). Commercial formulations used for this example are the P-free tab Finish Quantum from the United States market.

[0413] The results are recorded in Table 2 below.

TABLE-US-00002 TABLE 2 Polymers used Chemistry Filming Control (no additives) — 3 Diblock copolymer pAA-b-(pAA/AMPS 75/25) 3 (outside the invention) DPn = 200-28 (example 4) 5% active/tab Diblock copolymer pAA-b-(pAA/AMPS 75/25) 4-5 (according to the DPn = 60-60 invention) 5% active/tab (example 2) Diblock copolymer pAA-b-(pAA/AMPS 75/25) 5 (according to the DPn = 60-200 invention) 5% active/tab (example 3)

[0414] This example clearly demonstrates the effect of degree of polymerization for each block on the performances on the filming. A too high DPn (200) for acrylic acid block has an adverse impact on the filming. On the contrary, a high DPn for the block AA-s-AMPS improves the anti-filming effect.

EXAMPLE 11

[0415] The anti-filming performance of a diblock copolymer of the invention is compared to the performances of (co)polymers that do not comply with the specificities of the invention.

[0416] The protocol for testing anti-filming effect is the same as described in previous example 9 (see Table 3 below, column “Filming”). Commercial formulations used for this example are the P-free tabs Univert.

[0417] The results are recorded in Table 3 below.

TABLE-US-00003 TABLE 3 Polymers used Chemistry Filming Control (no additives)   5 Acusol 587 D from Statistical AA/AMPS 80/20 5 Dow Mw = 18700 g/mol 5% active/tab Diblock copolymer pAA-b-(pAA/AMPS 75/25) 6 (according to the DPn = 60-60 invention) 5% active/tab (example 2) Diblock copolymer pAA-b-(pAA/AMPS 50/50) 6 (according to the DPn = 60-60 invention) 5% active/tab (example 7)

EXAMPLE 12

[0418] The protocol for testing anti-filming effect is the same as described in previous example 9 (see Table 4 below, column “Filming”). Commercial formulations used for this example are the P-free tabs Univert.

[0419] The results are recorded in Table 4 below.

TABLE-US-00004 TABLE 4 Polymers used Chemistry Filming Control (no additives) — 5 Acusol 587 D from Statistical AA/AMPS 80/20 5 Dow Mw = 18700 g/mol 5% active/tab Diblock copolymer pAA-b-(pAA/AMPS 75/25) 6 (according to the DPn = 60-60 invention) 5% active/tab (example 2) Diblock copolymer pAA-b-(pAA/SVS 75/25) 7 (according to the DPn = 60-60 invention) 5% active/tab (example 5)

EXAMPLE 13

[0420] The protocol for testing anti-filming effect is the same as described in previous example 9 (see Table 5 below, column “Filming”). Commercial formulation used for this example is the SUN turbo gel all-in-one.

[0421] The results are recorded in Table 5 below.

TABLE-US-00005 TABLE 5 Polymers used Chemistry Filming Control (no additives) — 2-3 Acusol 587 D from Statistical AA/AMPS 80/20 5 Dow Mw = 18700 g/mol 5% active/detergent Diblock copolymer pAA-b-(pAA/AMPS 75/25) 6 (according to the DPn = 60-60 invention) 5% active/tab (example 2) Blend of homopolymer pAA 5 (example 1) and DPn = 60 statistical copolymer 2.1% act/detergent (example 6) and pAA/AMPS 75/25, DPn = 60 2.9% act/detergent

[0422] This example clearly demonstrates the ability of the copolymer of the invention (i.e. PAA-b-P(AA-s-AMPS 75/25)) to deliver glass appearance benefits superior to those provided by commercially available statistical copolymers or by the blend of the homopolymer and statistical copolymer in a P-free gel formulation.

[0423] This example also illustrates that the copolymers of the invention can be used in different forms of detergent.

EXAMPLE 14

[0424] The diblock polymer of the invention is tested in combination with the Mirapol SURF-S-480PF on the anti-filming and anti-spotting effects.

[0425] Mirapol SURF S 480PF is known as a rinse-aid copolymer which avoids the formation of droplets after the rinsing and, thus, resulting in a clear glass with no spotting.

[0426] In this example, the spotting and the filming are both evaluated after 3 washing cycles.

[0427] Washed glasses were scored using a 1-10 scale in which 1 is completely covered with spots or heavy chalky film and 10 is clear. Commercial formulation used for this example is the SUN Turbo gel all-in-one.

[0428] Results are recorded in Table 6 below.

TABLE-US-00006 TABLE 6 Polymers used Chemistry Filming Spotting Control (no additives) — 2-3 1 Acusol 587 D from Statistical AA/AMPS 80/20 5 1 Dow Mw = 18700 g/mol 5% active/detergent Mirapol Surf S 480 PF amphoteric copolymer 2 7 0.4% active/detergent Diblock copolymer pAA-b-(pAA/AMPS 75/25) 6 1 (according to the DPn = 60-60 invention) 5% active/detergent (example 2) Blend of Mirapol 0.4% actives of Mirapol + 5 5 SURF S 480 PF and 5% actives of diblock Diblock copolymer of (pAA-b-(pAA/AMPS 75/25) the invention DPn = 60-60)

[0429] This example clearly demonstrates the effect of the blend of rinse-aid copolymer such as Mirapol 480PF and a copolymer according to the invention; the blend improves the shine of glass, less filming and less spotting are observed compared to the commercial gel formulation.

EXAMPLE 15

[0430] Performance of the copolymer of the invention in an ADW composition.

[0431] Different polymers (see Table 7 below) were tested on two different types of glasses for their anti-filming effect for the washing of glasses in a automatic dishwasher after 30 cycles.

[0432] Test of Anti-Filming Effect Glass should be perfectly clean before testing and are initially cleaned with a high alkaline detergent. Then, glasses are cleaned with citric acid to remove the alkalinity.

[0433] Each glass should be checked under a black box that it is completely free of spot and film before use.

[0434] After this prewashing, the filming of the clean glasses is evaluated at 10, using a 1-10 scale in which 1 is completely covered with heavy chalky film and 10 is clear.

[0435] Then, the clean glasses are placed on a Miele G 1355 SC automatic dishwasher. 30 ADW cycles in automatic machines are run for an evaluation, with the introduction of 50 g of soil and 20 g of detergent at each cycle at 50° C., program Turbo.

[0436] The soil consists in weight percentage of 70% water, 5% milk, 2.5% mustard, 2.5% ketchup, 2.5% gravy, 0.5% potato starch, 0.4% benzoic acid, 10% margarine, 5% egg yolk.

[0437] Water Hardness was adjusted to 35° TH (21° dH). This water contains molar ratio of Ca:Mg of 3:1 (as salts used are CaCl.sub.2*2H.sub.2O and MgSO.sub.4*7H.sub.2O) and 400 mg/L NaHCO.sub.3.

[0438] The different (co)polymers (see Table 7 below) are tested in liquid form and added on a P-free lab formula from Henkel which does not contain any polymer.

[0439] The concentration of (co)polymer or blend of (co)polymers is 5% by weight of the total blend. 20.0 g of detergent are dosed via the dispenser cup of the automatic dishwasher.

[0440] After completion of the thirty wash programs, the appearance of the washed glassware was assessed visually using a light box, method inspired by ASTM Method D3556 85. The light box is essentially a darkened room with the glasses being placed on racks and illuminated from within to disclose spots or film. All interior surfaces of the light box are black, so that the only light present is that which passes up through the tumblers. Washed glasses were scored using the 1-10 scale in which 1 is completely covered with heavy chalky film and 10 is clear.

[0441] Results

[0442] The results are recorded in Table 7 below.

TABLE-US-00007 TABLE 7 Filming Polymers used Chemistry Glass 1 Glass 2 None (control) — 2.0 2.0 Benchmark polymer Polyacrylate type > 5.0 5.0 8% active/tab Diblock copolymer pAA-b-(pAA/AMPS 50/50) 6.0 6.0 (according to the DPn = 60-80 invention) 5% active/tab (example 8)

[0443] This example clearly demonstrates the ability of the copolymer of the invention (i.e. PAA-b-P(AA-s-AMPS 50/50)) to deliver glass appearance benefits with a low dosage compared to benchmark polymer available in the market.