DE10060738A1 - Use of polycarboxylate-based flow agents for non-casein, casein-free or low-casein self-leveling putty and leveling compounds - Google Patents

Abstract

The use of polycarboxylate-based superplasticizers consisting of water-soluble copolymers for casein-free or low-casein self-leveling leveling and leveling compounds containing alumina cement is described. The advantage of the flow agents used according to the invention is, on the one hand, the good flow, leveling and self-healing properties of the corresponding leveling and leveling compounds and, on the other hand, the fact that a very long-lasting processability can be achieved with extremely small quantities.

Description

The present invention is the use of Polycarboxylate-based flow aids for alumina cement-containing, Caseinfreie or caseinarme self-leveling spatula and Leveling compounds, as used for flooring work u. a. according to DIN 18 365 be used.

Casein, the most important protein constituent of milk, is usually made Cow's milk is obtained by acid precipitation and gets to clean and Drying as a white to yellowish powder on the market (see, inter alia. Rompp, Chemie Lexikon, Volume 1 (1989), page 601).

It is known to use casein as a superplasticizer in self-leveling filler and leveling compounds containing alumina cement, the effect of the casein being to achieve a particularly good processability of these materials, so that

• - The flowability is maintained over a longer period and
• - the masses after application and distribution on the ground of even a very smooth, level, seamless and error-free Surface run and thereby the desired effect of Show "self-healing", which means that the freshly applied and still flowable putty and leveling compounds for a certain amount of time be worked with a toothed spatula or a spiked roller can, without - from the effect of o. g. Tools originating - afterwards any furrows, waves or others Bumps remain, which the surface quality of hardened coating would affect.

Toner Smelting (TSZ) is a non-standard special cement made by fusing together bauxite (alumina) and limestone (calcium carbonate), the main clinker phase being monocalcium aluminate. As a hydraulic binder, TSZ is able to react very quickly with water and gives high initial compressive strengths (after 24 hours more than 40 N / mm ² ). Although TSZ is banned in Germany and other countries for all load-bearing components made of prestressed and reinforced concrete, since a TSZ embedded steel reinforcement is easily corroded due to the low pH value (≦ 9) (see, inter alia, Garlic, Schneider, "construction chemistry", Pages 129, 138, 141, 281, 3rd edition 1992). As a special cement for non-reinforced (non-structural) components, however, TSZ offers a number of technical advantages, which is why TSZ is mainly used in the following areas:

• - corrosion-resistant concretes and mortars (eg for wastewater technology)
• - refractory concretes and mortars (eg for the steel industry)
• - fast-setting mortar (installation mortar, repair mortar, Building adhesive, thin-bed mortar, tile adhesive, grout)
• - decorative artificial stones

A very special application of TSZ are quick-setting Self-leveling leveling and leveling compounds, in which as Binder usually a combination of TSZ with Portland cement and calcium sulfate is used.

There has been no lack of attempts, the flow, and history Self-healing properties of such casein-containing spatula and Balancing masses by partial or complete replacement of the casein by other superplasticizers - for example. Based on sulfonated melamine or Naphthalene-formaldehyde condensation products (so-called MFS or NSF resins) - to achieve. However, it has been shown that these Plasticizers can not be combined with casein, i. H. to a Deterioration of the liquefaction effect of casein lead, or that with these flow agents alone the excellent flow, leveling and and self-healing properties of casein-containing spatula and Compensation masses can not be achieved.

Another attempt was to make the casein in such spatula and Partially replace balancing weights with a special graft polymer. This combination of casein with the special graft polymer is in the DE-OS 44 21 722 A1 described. The combination represents progress However, this is only a partial solution to the problem, since the casein is not  is completely replaced and the casein-related ones mentioned below negative properties (mold growth, etc.) not completely eliminated become.

The desire to increase the content of casein in such spatula and Compensating masses have been reduced as much as possible Decades since Casein in addition to those listed above Processing advantages also have some significant disadvantages such as z. B. biodegradation and thereby mold, fluctuating Product quality and possibly also has ammonia release. These negative characteristics all contribute to a deterioration of the Indoor air hygiene at what z. B. in Scandinavian countries to a Ban on casein-containing filling and leveling compounds.

The present invention was therefore based on the object, flow agents to provide for self-leveling fillers and leveling compounds, which do not have the stated disadvantages of the prior art, but these systems good performance properties to lend.

This object has been achieved according to the invention by the use water-soluble polymers of polyoxyalkylene-containing structural units, Carboxylic acid and / or carboxylic acid anhydride monomers according to Claim 1 and optionally other monomers - in the further than Polycarboxylates (= PC) called.

It was surprisingly found that with these polymers as well good flow, leveling and self-healing properties of filler and Balancing masses can be achieved as with casein. This was not expected because - as described above - other superplasticizers the mode of action of Casein not reach (MFS or NSF resins) or only a partial solution of Pose problems (graft polymers).

The copolymers used according to the invention consist of the following components:

• a) 5 to 90 mol% of groups of the formula (Ia) and / or (Ib) and / or (Ic)
  where M = hydrogen, a monovalent or divalent metal cation, ammonium ion,
  a = ½ or 1,
  R ¹ = hydrogen or an aliphatic hydrocarbon radical having 1 to 20 C atoms,
  R ² and R ³ = hydrogen or methyl group,
  x = 0 to 2
  mean,
• b) 5 to 90 mol% of the structural groups of the general formula (IIa) and / or (IIb) and / or (IIc)
  wherein R ^{4 is} hydrogen, an aliphatic hydrocarbon radical having 1 to 20 C atoms, a cycloaliphatic hydrocarbon radical having 5 to 8 C atoms, an optionally substituted aryl radical having 6 to 14 C atoms,
  R ⁵ = hydrogen, optionally substituted by hydroxyl groups aliphatic hydrocarbon radical having 1 to 20 C-atoms, - (C _m H _2m O) _n -R ⁴ ,
  X is hydrogen, methyl group or -COOM _a ,
  m for 2 to 4,
  n for 0 to 200 as well
  y stand for 1 or 2 and
  R ¹ , M, a and x have the abovementioned meaning,
• c) 0 to 90 mol% of groups of the formula (IIIa) and / or (IIIb)
  wherein M, a, R ^{5 have the} abovementioned meaning,
  such as
• d) 0 to 90 mol% of the general formula (IV)
  wherein R ^{6 is} hydrogen or a methyl group and M and a have the abovementioned meaning.

Preferably, R ¹ , R ⁴ and R ^{5 represent} an aliphatic hydrocarbon radical having 1 to 4 carbon atoms. Particularly suitable monovalent or divalent metal cations for M are sodium, potassium, lithium, calcium or magnesium ions. In the case of R ⁴ = phenyl, the phenyl radical may still preferably be substituted by hydroxyl, carboxyl or sulfonic acid groups.

In a preferred embodiment, 0 to 33 mole%, based on the components a) to d), other polymerizable  Monomers, for example monomers based on N-vinyl compounds, vinyl Phosphorus compounds and optionally substituted acrylic or Methacrylamides for the construction of the copolymers of the invention used. Examples of such compounds are N-vinylpyrrolidone, Vinylphosphonic acid, 2-acrylamido-2-methylpropanesulfonic acid, etc.

From the group of copolymers based on unsaturated mono- and / or dicarboxylic acid derivatives and oxyalkylene glycol alkenyl ethers and / or esters, the following compounds have proven to be particularly advantageous:

• 1. Copolymers having 5 to 55 mol% of the components of the formula (Ia) and / or (Ib), 15 to 65 mol% of the formula (IIa) and 30 to 80 mol% (IIb).
• 2. Copolymers with 50 to 85 mol% of the components of the formula (Ia) and / or (Ic) and 15 to 50 mol% of the formula (IIa) and / or (IIb). These Copolymers may optionally also in the presence of 0.1 to 50 wt .-%, based on the monomers to be polymerized, phosphorus containing compounds have been prepared. suitable Compounds of this type are, for example, phosphinic, hypophosphorous Acid, phosphonic acid, phosphorous acid and the salts of said Acids.
• 3. Copolymers with 10 to 35 mol% of groups of the formula (Ia) and / or (Ib), 15 to 40 mol% of structural groups of the formula (IIa) and 50 to 75 mol% Assembly of the formula (IIIb).
• 4. Copolymers with 20 to 80 mol% of the formula (Ia) and / or (Ib), 10 bis 70 mol% of components of the formula (IIc), 10 to 70 mol% of assemblies of the formula (IIIb) and 0 to 60 mol% of the formula (IIIa).
• 5. Copolmers with 25 to 75 mol% of the formula (Ic), 10 to 60 mol% Modules of the formula (IIa) and 15 to 65 mol% of assemblies of the formula (IV).

These copolymers are known and, for example, in WO 97/39 037, EP-A 0 894 811, EP-A 0 736 553, EP-PS 0 610 699, WO 98/28 353, EP-A 0 983 976, WO 97/48 656, US Pat. No. 5,753,744 and EP-A 0 753 488. They preferably have an average molecular weight M _n of 5,000 to 150,000 g / mol.

The polymers are generally prepared by free-radical polymerization made with usual starters. The polymerization can be carried out in water, in Mixtures of water with up to 30% organic solvents such as. Alcohols or possibly be carried out in substance. From the watery Polymer solution can polymer powder by common methods such as For example. Spray drying and drum drying or by precipitation be won.

In a preferred embodiment, the polymeric flow agent becomes at a dosage of 0.02 to 2.0% by weight (based on the weight of the mineral constituents) and in powder form in the spatula and Balancing mass used. In the dry mortar mixture are Alumina cement and other mineral binders, fillers as well as other building materials additives such. B. Redispersible powder, stabilizer, Accelerator, defoamer, retarder and superplasticizer included. The Dry mortar mixture is delivered to the construction site and there with the prescribed amount of water to the ready-to-use filler and leveling compound mixed.

The use of the copolymers according to the invention is generally carried out by Mixing polymer powder with the binder (eg. Tonerdeschmelzzement) and with all other powdered Components of the dry mortar mixture. In isolated cases, too the addition of an aqueous solution of the polymer as used in the Polymerization is obtained or as by thinning the Polymerization solution or by dissolving polymer powder in water be made, make sense.  

As a further component, the flow agents according to the invention can also be combined with casein, the commercial types can be used easily. The weight ratio of inventive polymers to casein can be varied within wide limits wherein the ratio is preferably 100: 0 to 50:50 is set.

The advantage of the superplasticizer used according to the invention On the one hand, conventional products in cementitious building material systems are on the one hand in the good flow, course and self-healing properties of corresponding leveling and leveling compounds and on the other in the The fact that doing so with very small amounts of a long sustained processability.

The following examples are intended to illustrate the invention in more detail.  

applications

The following examples illustrate the fluidity, spreading and self-healing properties of self-leveling landfill clay-containing soil leveling compounds. For comparison, inventive and conventional flow agents were tested, namely

• - Casein (Havero 120 mesh)
• - Naphthalene-formaldehyde sulphite condensation product (NSF resin) (according to EP-PS 443 341, Example 2)
• - Melamine-formaldehyde sulphite condensation product (MFS resin) (according to DE-PS 16 71 017, Example A)
• Polycarboxylate 1 (according to WO 97/39 037 consisting of 25 mol% Maleic anhydride (Ib), 25 mole percent maleic MPEG-1150 ester (IIa) and 50 mol% styrene (IIIb))
• Polycarboxylate 2 (according to EP 0 753 488 A, Example 2)
• Polycarboxylate 3 (according to EP 0 894 811 A1 consisting of 30 mol% Maleic anhydride (Ib), 20 mole percent maleic acid MPEG-2000 ester (IIa) and 50 mol% ethylene glycol monovinyl ether (IIb))

As self-leveling bonding balance the following mixture was chosen:

Wt .-% Portland cement (CEM I 42.5 R) 18.50 High alumina cement (about 40% Al ₂ O ₃ ) 11,50 Calcium sulfate (anhydrous, synthetic anhydrite) 6.50 Quartz sand (0.1 to 0.315 mm) 41,00 Limestone flour (calcium carbonate, 10 to 20 μm) 19.40 Redispersion powder (VINNAPAS RE 523 Z, Wacker, Burghausen) 2.00 Hydroxyethylcellulose (Tylose H 300 P2, Clariant, Frankfurt) 0.05 lithium carbonate 0.10 Defoamer (Agitan P 800, Münzing Chemie) 0.15 Potassium sodium tartrate tetrahydrate 0.40 Plasticizer (Casein / NSF / MFS / PC) ^*) 0,40 ^*) Powder mixture (sum of powder components): 100.00 Mixing water (for 100.00 wt .-% powder mixture): 20.00 ^*) In the case of the NSF and MFS resins, the three-fold superplasticizer dosage was selected (1.20 wt .-%), so that in these cases, the sum of the powder components was 100.80 wt .-% and the mixing water 20, 00 wt .-% (for 100.80 wt .-% powder mixture) was.

mixing instructions

The mixing water was presented in a porcelain casserole (Mixing start t = 0 seconds) and the powder mixture was within of 30 seconds into the water.

After another 30 second wait, the mixture became 120 seconds mixed with a spoon to a homogeneous mass, then 60 Seconds left (maturing) and finally 60 seconds long stirred again with the spoon. The total mixing time was t = 5 Minutes.

With the after o. G. Mixed prescription produced masses were then the investigations described in more detail below carried out:

example 1 Flowability of leveling compounds with inventive polycarboxylates

The flowability of the soil leveling compounds was based on EN 12706 (November 1999 edition) with the prescribed ring (Inner diameter = 30 ± 0.1 mm, height = 50 ± 0.1 mm) on a flat, examined dry glass plate. The determination of the flow rate (= Diameter of the spread cake in mm) was five times per mixture performed at times t = 5, 15, 30, 45 and 60 minutes after the start of mixing, with the mixture in front of the respective Flow rate determination with the spoon stirred up again for 60 seconds has been.  

Table 1 and Fig. 1 show the tabulated and plotted results of flow measurements with some selected flow agents.

Table 1

Flow dimensions of a leveling compound with conventional and inventively used flow agents

The experiments prove that the polymers used according to the invention Flow agent at least a comparable liquefaction effect as Achieve casein over time. The effect of polymeric superplasticizers do not reach conventional flow agents even at very high dosage.

Example 2 Self-healing properties of balancing compositions according to the invention used polycarboxylates

The self-healing properties of the applied soil balance masses were examined with the so-called knife cut test. This was first a spreading cake at time t = 5 minutes on a flat Plastic plate produced, which in turn according to EN 12706 prescribed ring was used. By this left lying circular spreading pies were cuts with an ordinary one Kitchen knife pulled so that the blade of the knife during the entire cut (about 2 seconds) the plastic plate at the bottom  of the spread cake grazed. The knife cuts were among the five Times t = 7, 15, 30, 45 and 60 minutes after the start of mixing, in segments and in parallel at regular intervals to each other, so that the third cut (t = 30 minutes) pretty much the Spread cake divided into two equal halves.

The spreading cake was then at normal climate for 24 hours (+ 20 ° C, 65% relative humidity) stored for curing and Subsequently, the positions on which the day before the Knife cuts were applied, visually and possibly by feeling judged with your fingers after how good or bad the by the Knife cuts in the spreading cake made ridges healed again (i.e. flowed into each other) were.

To assess the self-healing properties, the following seven-level grading scale was established:
Grade 1: Section is complete, invisible
Grade 2: Section is running, but visible
Grade 3: cut runs, but edge visible
Grade 4: Cut runs, but edge is clearly visible
Grade 5: Cut is bad, incision remains
Grade 6: The incision is bad, the deeper incision remains
Grade 7: Cut does not go, cutting remains to the bottom of the coat

In order to create as even a scale as possible in the grading process could be compared with some of the already rated recovery patterns, which were kept helpful.

Table 2 contains the results of the knife edge tests (Self-healing properties) with conventional and inventive Flow agents.  

Figure 2 shows photos of some cured pancake that had been subjected to the above-described knife cut test.

Table 2

Knife cut tests (after 7, 15, 30, 45 and 60 minutes) and self-healing properties (grades according to the above scale) of an applied self-leveling soil leveling compound (liquefied with various flow agents, dosage in% by weight based on the dry mortar mixture)

The experiments prove that a polymeric flow agent according to the invention at least as good flow and self-healing properties as Casein scored.

Claims (14)

1. Use of superplasticizers based on polycarboxylates, consisting of water-soluble copolymers with

• a) 5 to 90 mol% of groups of the formula (Ia) and / or (Ib) and / or (Ic)
  where M = hydrogen, a monovalent or divalent metal cation, ammonium ion,
  a = ½ or 1,
  R ¹ = hydrogen or an aliphatic hydrocarbon radical having 1 to 20 C atoms,
  R ² and R ³ = hydrogen or methyl group,
  x = 0 to 2
  mean,
• b) 5 to 90 mol% of assemblies of the formula (IIa) and / or (IIb) and / or (IIc)
  wherein R ^{4 is} hydrogen, an aliphatic hydrocarbon radical having 1 to 20 C atoms, a cycloaliphatic hydrocarbon radical having 5 to 8 C atoms, an optionally substituted aryl radical having 6 to 14 C atoms,
  R ⁵ = hydrogen, optionally substituted by hydroxyl groups aliphatic hydrocarbon radical having 1 to 20 C-atoms, - (C _m H _2m O) _n -R ⁴ ,
  X is hydrogen, methyl group or -COOM _a ,
  m for 2 to 4,
  n for 0 to 200 as well
  y stand for 1 or 2 and
  R ¹ , M, a and x have the abovementioned meaning,
• c) 0 to 90 mol% of groups of the formula (IIIa) and / or (IIIb)
  wherein M, a, R ^{5 have the} abovementioned meaning,
  such as
• d) 0 to 90 mol% of the general formula (IV)
  wherein R ^{6 is} hydrogen or a methyl group and M and a have the abovementioned meaning,

for casein-free casein-free or low-casein self-leveling leveling compounds and leveling compounds. 2. Use according to claim 1, characterized in that the Copolymers of from 5 to 55 mol% of assemblies of the formula (Ia) and / or (Ib)  15 to 65 mol% of the formula (IIa) and 30 to 80 mol% of the formula (IIb) contain. 3. Use according to claim 1, characterized in that the Copolymers 50 to 85 mol% of groups of the formula (Ia) and / or (Ic) and 15 to 50 mol% of the formula (IIa) and / or (IIb). 4. Use according to claim 3, characterized in that the Copolymers in the presence of 0.1 to 50 wt .-%, based on the polymerizable monomers, phosphorus-containing compounds selected from the group phosphinic acid, hypophosphorous acid, Phosphoric acid, phosphorous acid or salts thereof have been. 5. Use according to claim 1, characterized in that the Copolymers 10 to 35 mol% of groups of the formula (Ia) and / or (Ib) 15 to 40 mol% of structural groups of the formula (IIa) and 50 to 75 mol% of the components of the formula (IIIb). 6. Use according to claim 1, characterized in that the Copolymers 20 to 80 mol% of the formula (Ia) and / or (Ib), 10 to 70 mol% Assembly of the formula (IIc), 10 to 70 mol% of the assemblies Formula (IIIb) and 0 to 60 mol% of the formula (IIIa) contain. 7. Use according to claim 1, characterized in that the Copolymers 25 to 75 mol% of the components of the formula (Ic), 10 to 60 mol% Assemblies of the formula (IIa) and 15 to 65 mol% of assemblies of the formula (IV). 8. Use according to one of claims 1 to 7, characterized characterized in that the copolymers still contain up to 33 mol% Monomers, based on the sum of the components a) to d), on the Base of N-vinyl compounds, vinyl-phosphorus compounds as well (optionally substituted) acrylic or methacrylamides have been prepared  are. 9. Use according to claim 8, characterized in that as additional monomers N-vinylpyrrolidone, vinylphosphonic acid, 2-acrylamido-2-methylpropanesulfonic acid, etc. have been used. 10. Use according to any one of claims 1 to 9, characterized in that the copolymers have an average molecular weight M _n of 5,000 to 15 0000 g / mol. 11. Use according to one of claims 1 to 10, characterized characterized in that the flow agents are used in powder form. 12. Use according to one of claims 1 to 11, characterized characterized in that the flow agents are present in an amount of 0.02 to 2% by weight. based on the content of mineral constituents be used. 13. Use according to one of claims 1 to 12, characterized characterized in that the flow agent in a dry mortar mixture consisting of alumina cement and other mineral Binders, fillers and building material additives - selected from Group of redispersible powders, stabilizers, accelerators, Defoamer, retarder - is used. 14. Use according to one of claims 1 to 13, characterized characterized in that the flow agents contain casein in a weight ratio 100: 0 to 50: 50 combined.