BRANCHED COPOLYMERS AS ADDITIVES FOR VISCOSITY REDUCTION OF MINERAL BINDER COMPOSITIONS

Abstract

The use of branched copolymers of the general structure (I) as additives for increasing the flow rate and for reducing the viscosity of mineral binder compositions. Further, mineral binder compositions including at least one branched copolymer of the general structure (I):

##STR00001##

Claims

1. A method comprising adding copolymers to a mineral binder composition in an amount effective for increasing the flow rate and/or for reducing the viscosity of the mineral binder composition, wherein the copolymers are prepared in a multistage process comprising the steps of 1) optionally reacting a starter S, selected from the group consisting of alcohols, amines, carboxylic acids and amides of the general formula R.sup.1-XH, with an alkoxylating agent and/or a halogenated alcohol or halogenated amine Hal-R.sup.2-XH, where R.sup.1 is a C1-C18 alkyl, C2-C18 alkylene, C3-C10 cycloalkyl, C6-C30 aryl, C7-C30 aralkyl or C1-C18 carbonyl, X is O or NH, Hal is Cl, Br or I, and R.sup.2is a C1-C16 alkyl, 2) reacting a starter S, selected from the group consisting of alcohols, amines, carboxylic acids and amides of the general formula R.sup.1-XH, where R.sup.1 is a C1-C18 alkyl, C2-C18 alkylene, C3-C10 cycloalkyl, C6-C30 aryl, C7-C30 aralkyl or C1-C18 carbonyl, X is O or NH, or the reaction product from step 1) with glycidol or epichlorohydrin or a mixture of glycidol and an alkoxylating agent or a mixture of epichlorohydrin and an alkoxylating agent, and 3) optionally reacting the reaction product from step 2) with an alkoxylating agent.

2. The method as claimed in claim 1, wherein the copolymers are copolymers of the general structure (I) ##STR00014## where R.sup.1 is a C1-C18 alkyl, C2-C18 alkylene, C3-C10 cycloalkyl, C6-C30 aryl, C7-C30 aralkyl or C1-C18 carbonyl, X is O or NH, A is in each case independently C1-C10 alkylene, R.sup.2 is a C1-C16 alkyl, B is in each case independently C1-C10 alkylene, R.sup.3 is H, C1-C16 alkyl, or C(O)R.sup.1 with R.sup.1 as defined above, m is in each case independently an integer in the range of 0-350, n is an integer in the range of 0-100, p is 0 or 1, q is an integer in the range of 1-10, and if q is 1, o is an integer in the range of 1-10, and, if q>1, each o is independently an integer in the range of 1-50.

3. The method as claimed in claim 1, wherein the copolymers are copolymers of the general structures (II), (III), or (V) ##STR00015## where R.sup.1 is selected from C1-C18 alkyl, A is in each case independently ethylene, propylene and/or butylene, B is in each case independently ethylene, propylene and/or butylene, m is in each case independently an integer in the range of 0-350, n is an integer in the range of 1-100, o is in each case independently an integer in the range of 1-50, q is an integer in the range of 1-10, and x is an integer in the range of 1-9, with the proviso that x<o.

4. The method as claimed in claim 1, wherein the average molar mass Mw of the copolymers is in the range of 200-75,000 g/mol.

5. The method as claimed in claim 1, wherein R.sup.1 is a C1-C18 alkyl unit.

6. The method as claimed in claim 1, wherein the mineral binder composition comprises at least one hydraulic binder, at at least 5% by weight, based on the dry mass of the mineral binder composition.

7. The method as claimed in claim 1, wherein the copolymer is present in an amount of 0.01-10% by weight, based on the total weight of mineral binder.

8. The method as claimed in claim 1, wherein the mineral binder composition further comprises water in such an amount as to result in a ratio of water to mineral binder in the range of 0.18-0.6.

9. The method as claimed in claim 1, wherein the mineral binder composition is a high-performance concrete, ultrahigh-performance concrete or self-compacting concrete.

10. The method as claimed in claim 1, wherein the mineral binder composition comprises at least one superplasticizer selected from the group of lignosulfonates, polynaphthalenesulfonates, polymelaminesulfonates and/or polycarboxylate ethers.

11. An additive for mineral binder compositions, comprising at least one copolymer prepared in a multistage process, the multistage process comprising the steps of 1) optionally reacting a starter S, selected from the group consisting of alcohols, amines, carboxylic acids and amides of the general formula R.sup.1-XH, with an alkoxylating agent and/or a halogenated alcohol or halogenated amine Hal-R.sup.2-XH, where R.sup.1 is a C1-C18 alkyl, C2-C18 alkylene, C3-C10 cycloalkyl, C6-C30 aryl, C7-C30 aralkyl or C1-C18 carbonyl, X is O or NH, Hal is Cl, Br or I, and R.sup.2 is a C1-C16 alkyl, 2) reacting a starter S, selected from the group consisting of alcohols, amines, carboxylic acids and amides of the general formula R.sup.1-XH, where R.sup.1 is a C1-C18 alkyl, C2-C18 alkylene, C3-C10 cycloalkyl, C6-C30 aryl, C7-C30 aralkyl or C1-C18 carbonyl, X is O or NH, or the reaction product from step 1) with glycidol or epichlorohydrin or a mixture of glycidol and an alkoxylating agent or a mixture of epichlorohydrin and an alkoxylating agent, and 3) optionally reacting the reaction product from step 2) with an alkoxylating agent.

12. The additive as claimed in claim 11, wherein the additive additionally comprises at least one polycarboxylate ether, where the ratio of copolymer to polycarboxylate ether is in the range between 0.05:5-1:1.

13. A method for controlling the rheology of a mineral binder composition, wherein an additive as claimed in claim 11 is added to the dry mix of the mineral binder composition and/or is added together with the mixing water and/or is added shortly after addition of the mixing water.

14. A mineral binder composition comprising at least one mineral binder and at least one copolymer prepared in a multistage process, the multistage process comprising the steps of 1) optionally reacting a starter S, selected from the group consisting of alcohols, amines, carboxylic acids and amides of the general formula R.sup.1-XH, with an alkoxylating agent and/or a halogenated alcohol or halogenated amine Hal-R.sup.2-XH, where R.sup.1 is a C1-C18 alkyl, C2-C18 alkylene, C3-C10 cycloalkyl, C6-C30 aryl, C7-C30 aralkyl or C1-C18 carbonyl, X is O or NH, Hal is Cl, Br or I, and R.sup.2 is a C1-C16 alkyl, 2) reacting a starter S, selected from the group consisting of alcohols, amines, carboxylic acids and amides of the general formula R.sup.1-XH, where R.sup.1 is a C1-C18 alkyl, C2-C18 alkylene, C3-C10 cycloalkyl, C6-C30 aryl, C7-C30 aralkyl or C1-C18 carbonyl, X is O or NH, or the reaction product from step 1) with glycidol or epichlorohydrin or a mixture of glycidol and an alkoxylating agent or a mixture of epichlorohydrin and an alkoxylating agent, and 3) optionally reacting the reaction product from step 2) with an alkoxylating agent.

15. A shaped body produced by curing a mineral binder composition as claimed in claim 14 after addition of water.

16. The method as claimed in claim 1, wherein R.sup.1 is selected from the group consisting of methyl, vinyl, allyl, methallyl, and isoprenyl.

17. The method as claimed in claim 1, wherein the starter S is selected from the group consisting of methanol, vinyl alcohol, allyl alcohol, methallyl alcohol and isoprenol.

18. The method as claimed in claim 1, wherein the starter S is methanol.

19. The method as claimed in claim 1, wherein the starter S is selected from the group consisting of vinyl alcohol, allyl alcohol and methallyl alcohol.

20. The method as claimed in claim 1, wherein the starter S is isoprenol.

Description

EXAMPLES

Example 1

Preparation of the Copolymers used

[0237] Preparation of C-1

[0238] Step 1: In a reactor inertized with N.sub.2 gas, 4 g (0.074 mol) of sodium methoxide are dissolved in 576 g (8 mol) of methallyl alcohol and heated to 100° C. This is followed by metered addition of 1760 g (40 mol) of ethylene oxide over the course of 5 hours.

[0239] In the course of this, the temperature is kept at 100 to 140° C. and the pressure at 1 to 3 bar. After the metered addition has ended, the reaction mixture is stirred at 140° C. for 2 hours. Subsequently, the mixture is cooled to 30° C.

[0240] Step 2: In a reactor inertized with N.sub.2 gas, 0.54 g (0.01 mol) of sodium methoxide is added to 123 g (0.42 mol) of the mixture from step 1) and heated to 130° C. This is followed by metered addition of 93 g (1.26 mol) of glycidol over the course of 30 minutes. In the course of this, the temperature is kept at 130 to 140° C. and the pressure at 1 to 3 bar. After the metered addition has ended, the reaction mixture is stirred at 140° C. for 2 hours. The mixture is left to cool to 50° C.

[0241] Step 3: After cooling to 50° C., 2.2 g (0.04 mol) of sodium methoxide are added to the mixture from step 2). The reactor is inertized again with N.sub.2 gas and heated to 130° C. This is followed by metered addition of 628 g (14.27 mol) of ethylene oxide over the course of 4 hours. In the course of this, the temperature is kept at 130 to 140° C. and the pressure at 0 to 3 bar. After the metered addition has ended, the reaction mixture is stirred at 140° C. for 3 hours. Subsequently, the mixture is cooled to 50° C. and neutralized with 3.2 g (0.054 mol) of acetic acid. The resultant mixture is the inventive copolymer C-1.

[0242] Preparation of C-2

[0243] The preparation of C-2 is analogous to the preparation of C-1. However, 2513 g of ethylene oxide (57 mol) are metered in for preparation of C-2 in step 3).

[0244] Preparation of C-4

[0245] The preparation of C-4 is analogous to the preparation of C-1. However, in step 1), 256 g of methanol (8 mol) are used in place of methallyl alcohol.

[0246] Preparation of C-5

[0247] The preparation of C-5 is analogous to the preparation of C-4. However, 2513 g of ethylene oxide (57 mol) are metered in for preparation of C-5 in step 3).

[0248] Preparation of C-6

[0249] The preparation of C-6 is analogous to the preparation of C-5. However, 186 g (2.51 mol) of glycidol are metered in for preparation of C-6 in step 2).

[0250] Table 1 below gives an overview of the PCEs and copolymers used as additives.

TABLE-US-00001 TABLE 1 Overview of the PCEs and polymers used as additives R-1 Aqueous solution of a PCE (55% dry matter) formed from acrylic acid (3.6 mol) and ethoxylated methallyl alcohol (Mw = 2'400 g/mol; 1 mol) R-2 Aqueous solution of a PCE (30% dry matter) formed from polyacrylic acid (Mw = 5'000 g/mol), esterified with a mixture of two methyl polyethylene glycols (Mw = 1'000 g/mol and 3'000 g/mol, molar ratio 1.3:1) in a molar ratio of acid and ester of 1.9:1. R-3 ViscoCrete 1100 NT (available from Sika AG) PPG polypropylene glycol (Mn = 192 g/mol) PEG polyethylene glycol (Mn = 150 g/mol) C-1 Copolymer prepared by successive reaction of methallyl alcohol with 1) 5 equivalents of ethylene oxide 2) 3 equivalents of glycidol 3) 34 equivalents of ethylene oxide C-2 Copolymer prepared by successive reaction of methallyl alcohol with 1) 5 equivalents of ethylene oxide 2) 3 equivalents of glycidol 3) 136 equivalents of ethylene oxide C-4 Copolymer prepared by successive reaction of methanol with 1) 5 equivalents of ethylene oxide 2) 3 equivalents of glycidol 3) 34 equivalents of ethylene oxide C-5 Copolymer prepared by successive reaction of methanol with 1) 5 equivalents of ethylene oxide 2) 3 equivalents of glycidol 3) 136 equivalents of ethylene oxide C-6 Copolymer prepared by successive reaction of methanol with 1) 5 equivalents of ethylene oxide 2) 6 equivalents of glycidol 3) 136 equivalents of ethylene oxide

Example 2

Paste Tests

[0251] A dry mix was produced, consisting of 150 g of cement (CEM I 42.5 N from Vigier Holding AG), 5.8 g of microsilica (SikaFume® -HR/-TU, available from Sika Schweiz AG), 69.2 g of blast furnace slag (Regen GGBS from Hanson UK) and 41.5 g of limestone (Nekafill 15 from Kalkfabrik Netstal AG). For production of the dry mix, the constituents were dry mixed in a Hobart mixer for 30 seconds. Added to this dry mixture were the additives specified in table 2, each dissolved in 60 g of water. Mixing was continued at level 1 for 30 seconds, and finally at level 2 for 3.5 minutes.

[0252] Flow times according to DIN EN 12350-9 and spread according to DIN EN 12350-5 were measured on the cement pastes obtained. What was measured in each case was the time after which 210 g of the respective mixture V1-V3 (noninventive) or E1-E3 (inventive) had run out completely. Table 2 below gives an overview of the results.

TABLE-US-00002 TABLE 2 Results of the paste tests Test Additive* Flow time [s] Spread [mm] V1 3% R-1 215 165 V2 3% R-1 + 1% PPG 423 170 V3 3% R-1 + 1% PEG 387 172 E1 3% R-1 + 1% C-4 180 163 E2 3% R-1 + 3% C-4 150 165 E3 3% R-1 + 1% C-6 150 164 *dosage in percent by weight relative to the dry weight of the cement

[0253] It becomes clear from table 2 that the use of inventive copolymers in experiments E1-E3 leads to a reduction in flow time, corresponding to an improvement in flowability or a reduction in viscosity. Comparison is made here with a noninventive reference V1 containing solely PCE and no copolymer of the invention. In addition, it becomes clear from table 2 that the copolymers of the invention do not cause any additional liquefaction, i.e. do not cause any reduction in water demand. Finally, it becomes clear from table 2 that the use of polyethylene glycol or polypropylene glycol leads in particular to a distinct increase in flow time. This corresponds to an elevated viscosity.

Example 3

Mortar Tests

[0254] A dry mix was produced, consisting of 735 g of cement (CEM I 42.5 N from Vigier Holding AG), 28 g of microsilica (SikaFume® -HR/-TU, available from Sika Schweiz AG), 340 g of blast furnace slag (Regen GGBS from Hanson UK), 203 g of limestone (Nekafill 15 from Kalkfabrik Netstal AG) and 2845 g of aggregates having a particle size of 0-8 mm. For production of the dry mix, the constituents were dry mixed in a Hobart mixer for 30 seconds. Added to this dry mixture were the additives specified in table 3, each dissolved in the amount of water specified in table 3. Mixing was continued at level 1 for 30 seconds, and finally at level 2 for 3.5 minutes.

[0255] Spread according to DIN EN 12350-5 was measured on the mortar obtained directly after mixing (0 minutes) and after a period of 30 minutes. In addition, the funnel flow time was measured to DIN EN 12350-9. Table 3 below gives an overview of the results.

TABLE-US-00003 TABLE 3 Results of the mortar tests Water Spread [mm] Funnel flow Test Additive* [g] 0′ 30′ time [s] V4   3% R-2 250 264 249 310 E4   3% R-2 250 272 256  80   1% C-4 E5   3% R-2 250 268 261 104   3% C-4 E6   3% R-2 247 263 247 236 0.5% C-4 E7   3% R-2 247 265 253 300 0.5% C-5 E8   3% R-2 247 262 242 240 0.5% C-6 E9   3% R-2 244 267 254 181   1% C-4 E10   3% R-2 244 250 269 n.m.   1% C-5 E11   3% R-2 244 263 253 243   1% C-6 E12   3% R-2 232 263 244 210   3% C-4 *dosage in percent by weight relative to the dry weight of the cement n.m.: not measured

[0256] Inventive experiments E4 and E5 show a distinct reduction in flow time from the V funnel compared to the noninventive experiment V4. This corresponds to an improvement in flowability, or a reduction in viscosity. Inventive experiments E6-E11 show that an improvement in flowability or a reduction in viscosity can also be achieved when the amount of water is reduced.

[0257] The results from table 3 also show that the use of copolymers of the invention has only a minor influence on spread, and hence the yield point of mineral binder compositions varies only slightly.

Example 4

Concrete Tests

[0258] A dry mix was produced, consisting of 340 g of cement (CEM I 42.5 N from Vigier Holding AG), 851 g of quartz sand and 951 g of gravel. For production of the dry mix, the constituents were dry mixed in a Hobart mixer for 30 seconds. Added to this dry mix were the additives specified in table 4, each dissolved in 170 g of water. Mixing was continued at level 1 for 30 seconds, and finally at level 2 for 3.5 minutes.

[0259] Slump according to JIS A1150 and flow rate according to JSCE-F-514 were measured on the concretes obtained. Table 4 below gives an overview of the results.

TABLE-US-00004 TABLE 4 Results of the concrete tests Slump Flow Test Additive* [mm] rate [cm/s] V5  1.1% R-3 235 28.0 E13 0.95% R-3 240 40.8  0.5% C-1 E14 0.95% R-3 235 34.5  0.5% C-2 *dosage in percent by weight relative to the dry weight of the cement

[0260] It becomes clear from a comparison of inventive experiments E13 and E14 with noninventive experiment V5 that the inventive use of copolymers can distinctly increase the flow rate, corresponding to a reduction in viscosity.

Example 5

Mortar Tests

[0261] The dry mix from example 4 was passed through a sieve having a mesh size of 5 mm. Added to the resulting dry mix were the additives specified in table 5, each dissolved in 170 g of water. Mixing was effected in a Hobart mixer at level 1 for 30 seconds, and finally further mixing at level 2 for 3.5 minutes.

[0262] Spread according to JIS A1150 and a run time according to JSCE-F 541-1999 were determined on the resulting mortar mixtures. Table 5 below gives an overview of the results.

TABLE-US-00005 TABLE 5 Results of the mortar tests Spread Run Test Additive* [mm] time [s] V6  1.1% R-3 100 47.7 E15 0.95% R-3 103 24.3  0.5% C-1 E16 0.95% R-3 105 27.1  0.5% C-2 *dosage in percent by weight relative to the dry weight of the cement

[0263] It becomes clear from a comparison of inventive experiments E15 and E16 with noninventive experiment V6 that the inventive use of copolymers can distinctly reduce the outflow time, corresponding to a reduction in viscosity.