POLYMER SUITABLE AS A THICKENER

Abstract

The invention relates to polymer comprising structural units according to formula (I), R.sup.1—X—(C═O)—NH—R.sup.2—NH—(C═O)—O—POA-R.sup.3—(O—POA-R.sup.4).sub.n wherein R.sup.1 represents an organic group terminated by a hydrocarbyl group having 6 to 50 carbon atoms, X represents O or N—R.sup.5, wherein R5 represents a hydrogen atom or a hydrocarbyl group having 1 to 30 carbon atoms, R.sup.2 represents an aliphatic hydrocarbyl group having 4 to 40 carbon atoms, POA represents a polyoxyalkylene group, R3 represents an organic group having 2 to 40 carbon atoms, n is an integer from 1 to 6, R.sup.4 is independently selected from —(C═O)—NH—R.sup.2—NH—(C═O)—X—R.sup.1, —(C═O)—NH—R.sup.1, —R.sup.6, wherein R.sup.6 represents a hydrogen atom or an aliphatic or aromatic group having 1 to 24 carbon atoms, and wherein the polymer has an average of at least 1.8 end groups R.sup.1 per molecule, a number average molecular weight in the range of 2000 to 100000 Daltons, a polydispersity in the range of 1.0 to 5.0, wherein the quotient of the polydispersity divided by (n+1) is less than 1.0, with the proviso that the polymer is not the reaction product of a) the mono-adduct of isophorone diisocyanate with 1-dodecanol and b) a polyether based on glycerol and a mixture of ethylene oxide and propylene oxide with an OH number of 18 mg KOH/g.

Claims

1. A polymer comprising structural units according to formula (I),
R.sup.1—X—(C═O)—NH—R.sup.2—NH—(C═O)—O—POA-R.sup.3—(O—POA-R.sup.4).sub.n wherein R.sup.1 represents an organic group terminated by a hydrocarbyl group having 6 to 50 carbon atoms, X represents O or N—R.sup.5, wherein R.sup.5 represents a hydrogen atom or a hydrocarbyl group having 1 to 30 carbon atoms, R.sup.2 represents an aliphatic hydrocarbyl group having 4 to 40 carbon atoms, POA represents a polyoxyalkylene group, R.sup.3 represents an organic group having 2 to 40 carbon atoms, n is an integer from 1 to 6, R.sup.4 is independently selected from —(C═O)—NH—R.sup.2—NH—(C═O)—X—R.sup.1, —(C═O)—NH—R.sup.1, —R.sup.6, wherein R.sup.6 represents a hydrogen atom or an aliphatic or aromatic group having 1 to 24 carbon atoms, and wherein the polymer has an average of at least 1.8 end groups R.sup.1 per molecule, a number average molecular weight in the range of 2000 to 100000 g/mol (Daltons), a polydispersity in the range of 1.0 to 5.0, wherein the quotient of the polydispersity divided by (n+1) is less than 1.0, with the proviso that the polymer is not the reaction product of a) the mono-adduct of isophorone diisocyanate with 1-dodecanol and b) a polyether based on glycerol and a mixture of ethylene oxide and propylene oxide with an OH number of 18 mg KOH/g.

2. The polymer according to claim 1, wherein X is O.

3. The polymer according to claim 1, wherein at least one R.sup.1 represents a polyoxyalkylene group terminated by a hydrocarbyl group having 6 to 50 carbon atoms.

4. The polymer according to claim 1, wherein at least one R.sup.1 represents a hydrocarbyl group having 6 to 30 carbon atoms.

5. The polymer according to claim 1, wherein the polyoxyalkylene group comprises repeating units selected from —[C.sub.2H.sub.4—O]— and —[C.sub.3H.sub.6—O]—.

6. The polymer according to claim 1, having a content of the structural units according to formula (I) of at least 70% by weight, calculated on the total mass of the polymer.

7. A process for preparing a polymer according to claim 1, comprising reacting a compound of formula
R.sup.1—X—(C═O)—NH—R.sup.2—NCO  (II) and a compound of formula
HO—POA-R.sup.3—(O—POA-R.sup.4).sub.n  (III), wherein R.sup.1 to R.sup.4, POA, X, and n are as defined above.

8. The process according to claim 7, wherein the compound of formula (II) is obtained by reacting a diisocyanate of formula OCN—R.sup.2—NCO (IV) and a compound of formula R.sup.1—XH (V).

9. The process according to claim 8, wherein the isocyanate groups of the diisocyanate of formula (IV) differ in reactivity towards the compound of formula (V).

10. (canceled)

11. A composition comprising a) a continuous aqueous liquid phase, b) the polymer according to claim 1 dissolved in the continuous aqueous liquid phase, and c) a hydrophobic component dispersed in the continuous aqueous liquid phase.

12. The composition according to claim 11, wherein the hydrophobic component is an organic film-forming binder.

13. The composition according to claim 11, further comprising solid particles.

14. The composition according to claim 13, wherein the solid particles are selected from pigments, fillers, and combinations thereof.

15. An additive composition comprising a) 10.0 to 60.0% by weight of the polymer according to claim 1, b) 40.0 to 90.0% by weight of water, c) 0.0 to 1.0% by weight of a biocide, and d) 0.0 to 75.0% by weight of a viscosity depressant.

Description

EXAMPLES

[0082] Preparation of Starting Materials, Polymers According to the Invention, and Comparative Polymers

[0083] Molecular weights and molecular weight distributions were determined using gel permeation chromatography (GPC) according to DIN 55672 part 1 (2016-03). Tetrahydrofuran (THF) was used as the eluent. The calibration was achieved using narrowly distributed linear polyethylene glycol standards of molecular weights between 44,000 and 238 g/mol. The temperature of the column system was 40° C.

[0084] Description of Raw Materials Used

TABLE-US-00001 Trade designation Chemical Description Supplier isophorone diisocyanate MERCK benzoyl chloride SIGMA-ALDRICH 1-octanol SASOL Polyglykol Polyglykol 8000 S - a polyethylene Clariant 8000 glycol with a mean molecular (PEG-8) weight of 8000 K-KAT 348 Bismuth carboxylate catalyst KING Industries

List of Abbreviations Used

[0085] IPDI: isophorone diisocyanate
PEG: polyethylene glycol
PDI: polydispersity index
Mn: number average molecular weight
Mw: weight average molecular weight

[0086] Preparation of Mono-Adducts of Diisocyanates and Monoalcohols

[0087] Alcohols were reacted with a diisocyanate to form a mono-adduct according to the procedure described in EP 1188779. All mono-adducts were prepared in two steps comprising the synthesis and removal of excess diisocyanate by thin film evaporation.

[0088] IPDI and benzoyl chloride were heated to 40° C. and the alcohol was added dropwise. The reaction mixture was heated up to 60° C. and stirred for 3 hours. The reaction conversion was controlled by the measurement of the isocyanate value.

[0089] Afterwards, the distillation of excess IPDI was done via a thin-film evaporator at a temperature between 100° C. and 150° C. After this step, the mono-adducts contained less than 0.2% by weight of residual diisocyanate.

TABLE-US-00002 TABLE 1 Overview of mono-adducts Monoadduct no. alcohol isocyanate MA-1 1-octanol IPDI

[0090] Preparation of Polymers According to the Invention and Comparative Polymers

Examples According to the Invention

[0091] Urethane UR-1 In a four-neck round bottom flask equipped with stirrer, reflux condenser and nitrogen inlet, 181.30 g (22.9 mmol) of the Polyglykol 8000 were heated to 90° C. 0.10 g of a bismuth carboxylate catalyst were added and after homogenization, 18.7 g (45.9 mmol) of MA-1 were added. The reaction mixture was reacted for 3 h at 90° C. The reaction product is a highly viscous white product.

Comparative Example CE-1

[0092] In a four-neck round bottom flask equipped with stirrer, reflux condenser and nitrogen inlet, 185.00 g (22.3 mmol) of Polyglykol 8000 were heated to 90° C. 5.79 g (44.5 mmol) of 1-octanol and 0.10 g of a bismuth carboxylate catalyst were added. After homogenization of this mixture, 9.89 g (44.5 mmol) of IPDI were added and the reaction mixture was reacted for 3 h at 90° C. The reaction product is a highly viscous white product.

TABLE-US-00003 TABLE 2 Overview of polymers prepared Mn Mw Example Monoadduct Polyether Alcohol [g/mol] [g/mol] PDI PDI/(n + 1) UR-1 1-octanol PEG 8000 5346 9994 1.87 0.94 CE-1 PEG 8000 1-octanol 7229 24931 3.45 1.73

[0093] Preparation of an Additive Composition

[0094] The polyurethanes UR-1 and CE-1 were dissolved in the following formulations to form an aqueous additive composition.

TABLE-US-00004 TABLE 3 Additive compositions Component Description concentration [wt. %] UR-1/CE-1 polyurethane 20.00 Viscosity nonionic surfactant based 20.00 depressant 1 on block copolymer of propylene oxide and ethylene oxide with 30% ethylene oxide Water 59.70 Acticide MBS 1,2-benzisothiazolin-3- 0.30 (Biocide) one & 2-methyl-4- isothiazolin-3-one

TABLE-US-00005 TABLE 4 Binders for application testing Binder Technical description Manufacturer AC 2025 Acrylate dispersion Alberdingk Boley GmbH; Krefeld, Germany Acronal S 760 Acrylic-styrene BASF Corporation; Charlotte, copolymer dispersion North Carolina, United States Uradil AZ554 Alkyd emulsion DSM Coating Resins; Zwolle, Netherlands

[0095] Incorporation of Additive Compositions:

[0096] The additive compositions are post added under stirring and well incorporated for 5 minutes by using a Dispermat LC3 (VMA Getzmann GmbH; Reichshof, Germany).

[0097] Measurements of Rheology Properties in Binders:

[0098] The reported values of the shear viscosity of the binders were measured with a Rheometer Physica MCR 301 (Anton Paar GmbH; Graz, Austria; CSR measurement, cone 2.5 cm, 1°, shear rate 0.1-10000 1/s, 23° C.).

TABLE-US-00006 TABLE 5 Measured viscosity values [Pas] in binder AC 2025 (active substance dosage: 0.1 wt-%) Viscosity [Pas] Viscosity [Pas] Viscosity [Pas] Viscosity [Pas] Viscosity [Pas] at shear rate at shear rate 1 at shear rate at shear rate at shear rate Sample 0.1 [1/s] [1/s] 10 [1/s] 100 [1/s] 1000 [1/s] Control 2.22 1.91 1.21 0.38 0.11 UR-1 93.07 38.99 12.98 4.23 1.08 CE-1 45.35 21.04 6.47 1.78 0.49

TABLE-US-00007 TABLE 6 Measured viscosity values [Pas] in binder Acronal S 760 (active substance dosage: 0.2 wt-%): Viscosity [Pas] Viscosity [Pas] Viscosity [Pas] Viscosity [Pas] Viscosity [Pas] at shear rate at shear rate 1 at shear rate at shear rate at shear rate Sample 0.1 [1/s] [1/s] 10 [1/s] 100 [1/s] 1000 [1/s] Control 48.22 7.49 1.49 0.39 0.15 UR-1 70.5 9.94 2.13 0.71 0.34 CE-1 36.74 6.32 1.44 0.45 0.19

TABLE-US-00008 TABLE 7 Measured viscosity values [Pas] in binder Uradil AZ554 (active substance dosage: 0.2 wt-%): Viscosity [Pas] Viscosity [Pas] Viscosity [Pas] Viscosity [Pas] Viscosity [Pas] at shear rate at shear rate 1 at shear rate at shear rate at shear rate Sample 0.1 [1/s] [1/s] 10 [1/s] 100 [1/s] 1000 [1/s] Control 1.05 0.83 0.51 0.26 0.09 UR-1 2.76 2.37 1.54 0.76 0.31 CE-1 1.01 0.96 0.69 0.43 0.18

CONCLUSION

[0099] The inventive polymer UR-1 has been compared in various binders to a polymer made in a random polymerization as described for comparative example CE-1. As can be seen in Table 5, 6 and 7, the inventive polymer is superior to the non-inventive comparative example with respect to viscosity increase at the examined shear rates. Therefore, the inventive polymer UR-1 is a more efficient thickener causing increased shear viscosity in comparison to CE-1.