WO2010112197A1

WO2010112197A1 - Fibrous material as an additive for a construction product

Info

Publication number: WO2010112197A1
Application number: PCT/EP2010/002015
Authority: WO
Inventors: Ralf Recknagel; Hans-Georg Brendle
Original assignee: J. Rettenmaier & Söhne Gmbh + Co. Kg
Priority date: 2009-03-30
Filing date: 2010-03-30
Publication date: 2010-10-07
Also published as: DE102009014957A1

Abstract

The invention relates to a fibrous material as an additive for a construction product having water-insoluble fibers that contain cellulose. The whole surface of the individual fiber is coated with a hydrophobing agent and/or a plastizer.

Description

Fiber as an additive for a construction product

The invention relates to fibrous materials as an additive for a construction product, as well as construction products containing such fibrous materials.

In the field of construction products fibers of any kind are used, in particular cellulose-containing fibers. The term "construction products" means, for example, cementitious self-leveling compounds, flow screeds, cement anhydride systems, quick cements, adhesive slips, plasters.

By adding such cellulose-containing fibers, the quality of the construction product is to be improved. These include the extension of open time, as well as a reinforcement by the fibers. If the fibers are unmodified, this leads to an increase of the water-cement factor in cement products, which can unduly deteriorate the mechanical properties (for example in screed masses).

When it comes to dry mortar, the addition of additives such as the fibers mentioned is necessary to obtain a permanently weather-resistant solid mortar.

A problem with such products may be the water absorption of the fibers: Self-leveling compounds and screed masses are usually provided with flow agents. Unmodified cellulose fibers deteriorate - depending on their amount used and their fiber length - the self-development properties in an inadmissible manner.

In plastering, on the one hand, there are relatively high-priced, durable silicate systems based on waterglass and special acrylic resins, which require a lot of know-how in basic surface treatment and the installations.

On the other hand, many dry mortar manufacturers, based on low-cost cement or lime cement plaster, also want to promote the durability of their products; some hydrophobing additives are either incompatible with the Dry mortar (for example liquid silicone resin emulsions), not meterable (for example waxes) or sensitive to leaching (for example powdered fatty acid derivatives).

Cleaning mortar should protect components against harmful environmental influences.

Pork lard forms calcium stearate with lime, which can be used for water-repellent plasters (Milizia, 1784). Even today, cement-based and anhydride-bound facade building materials are rendered hydrophobic by 0.1-2.0% by weight of powdered additives such as fatty acid salts (sodium oleate, calcium iron stearate). Their effectiveness and durability in driving rain and frost is significantly limited by degradation and leaching. In the plaster standard DIN 18550 Part 1/2, therefore, requirements are made of the capillary water absorption and the water vapor diffusion, for example, to ensure sufficient weather resistance. Due to the particle structure and the chemical structure stearates can not control the water balance and the hardening of the mortar.

For adhesive and plaster mortars, hydrophobic spray-dried dispersion powders (DP) have been developed, e.g. to better comply with the standards for water storage. The amount of DP used can be up to 5.0% by weight for C 2 adhesives. As a result, the DP contributes significantly to the formulation costs. The DP primarily provides a modification of the cement's solid properties. By using hydrophobic DP solid mortar properties and hydrophobicity can not be set independently.

Even with thermal insulation composite systems, the water-cement factor is crucial, among other things, for the mechanical properties. Occasionally, water-repellent dispersion powder is used to precisely adjust the mortar consistency. The ETICS renders receive (especially in Central Europe) subsequently an additional water-repellent protective coating, the use of hydrophobic DP is often not sufficient. For emulsion paints, hydrophobic water-soluble hydroxyethylcelluloses (HEC) have existed on the market for several years. In the production of this HEC, in addition to the etherification, a further reaction with alkyl glycidyl ether must be carried out. The influence of the hydrophobic HEC on the hydrophobicity of the system after curing is limited due to the small amount used (usually below 0.4 wt .-%). An important reason for the use of hydrophobized HEC is their good compatibility with associative system thickeners based on polyurethane, which do not thicken the dilution water, but act directly on the binder rheology; These relatively effective system thickeners are increasingly being used.

In order to optimize the dispersions, in the individual case of pure acrylic, the more resistant acrylic silicate is changed, since the binder decisively influences the film properties. For example, the hydrophobic HEC contributes little to the early water resistance of coatings and paints.

Cement self-leveling compounds and self-leveling screeds require, in addition to superplasticizers, other additives for proper processing. Typical for cementitious screed masses are up to three filler fractions (usually spherical quartz sands), which ensure high degree of filling, high density and a sufficient slump. With flowing screed that is

Cement weight preferably 200 to 450 kg, in individual cases up to 550 kg, the water-cement ratio is preferably very low. Some newly developed calcium aluminum cements for screed work without superplasticizer but require a sulfate carrier. The water repellency of these compositions is often adjusted by stearates or hydrophobic DP. The thickeners used are less than 0.1% by weight of low-viscosity to low-viscosity cellulose ethers, as well as synthetic polymers. A major problem in the processing of the masses is segregation of the fillers as well as bleeding of the cement glue and cracking. The cellulose ethers do not provide fiber reinforcement or drainage because of their water solubility.

Micro-cracks, segregation, inhomogeneities in the structure, uneven hardening, high air pore content and rough surfaces are the points of attack for further profound damage to the cement; Of these, heavily loaded and drivable areas are particularly affected. Additives are customary in the industry, such as dispersion powders and stabilizers and viscosifiers for the compensation of inorganic binders. The commercial products which are offered for stabilization are, for example, pre-reacted prepolymers, such as longer-chain melamine sulfonates or copolymers. These products are aimed at modifying the flow agent, especially as they are compatible with this and soluble in it. The electrostatic mechanisms for flow regulation are often the same as for the flow agent. A modification of the

Self-leveling compounds by means of a water-insoluble hydrophobic cellulosic fiber is not yet known. Furthermore, no additive is known which at the same time prevents segregation in the screed, promotes deaeration and provides a fiber reinforcement.

In the manufacture of plasterboard, a variety of additives such as accelerators and retarders, thickeners and plasticizers are used simultaneously. Drying of the plasterboard by drainage action can not be accelerated with modified cellulosic fibers as the fibers result in an increase in the water-cement factor.

The invention has for its object to provide a pulp, which is suitable as an additive for a construction product, which prevents the absorption of water through the fiber. In addition, a construction product from the series of building products mentioned above is to be given, which has the desired properties of the product, thus, for example, self-leveling compounds and self-leveling screeds the property of self-leveling and self-leveling.

This object is solved by the features of the independent claims. The inventors have recognized the following:

The addition of water repellents was always done in the mass. See for example DE 10 2007 016 783 A1, there paragraph [0042], or DE 103 37 011 A1, see there paragraph [0058].

However, such an addition to the mass could not lead to success. The fibers are in fact embedded in the remaining components of the construction product. Therefore, the hydrophobizing agent or the flow agent can not wet and coat the entire surface of the individual fiber. If there are coating-free areas, water will penetrate here and lead to a swelling of the fiber. This is also not avoided by an increased addition of hydrophobing agent. As a result, only the production costs are increased, without any significant benefit.

The inventors have derived from this knowledge the doctrine that the fibers are to be treated in isolation, that is, before they are supplied to the mass of the construction product. This alone leads to complete success.

Thus, the addition of a compound of hydrophobic cellulose fiber and superplasticizer provides a variety of processing and product advantages (drainage and faster drying of plasterboard, better ventilation and segregation control of cement screed), without significantly affecting the water-binder factor.

The cellulose-containing fiber compound according to the invention is surprisingly able to significantly improve the processability of a large number of self-leveling construction products (screed, quick-setting cement, cement primer, underlayment, self-leveling compounds). The cellulose fiber can - depending on the fiber length - contribute to the stability and to the regulation of the water balance. The flow agents for adjusting the amount of cement slurry are generally used in an amount of 0.5 to 3.0% by weight. used. These superplasticizers often cause additional problems in dosage, processing and also in the final product, for example

1. Segregation and sedimentation of the filler

2. Bleeding of the cement paste (separation of mixing water) 3. Microcracks

4. Volume shrinkage and bowls

5. Absands

6. Rough surfaces and embrittlement

The cellulose-containing stabilizing and

Viscosifying agent was produced on the basis of cellulose-containing raw materials and tested in various construction chemical applications. For this purpose, it is necessary to modify the cellulose fiber so that the component can be further processed for the production of a stabilizer and viscosifier:

a) hydrophobicity. To adjust the water-repellent properties, it is preferred to use alkylketene dimer AKD, an alkyl- or alkylene-succinic acid derivative ASA or polymer sizing agent PSA, furthermore alum and organosilicon compounds, and also newly developed fatty acid derivatives.

b) Superplastication. To adjust the plasticizing properties in FE, the fiber is coated, co-processed, mixed or loaded with a flow agent. The superplasticizer may be, for example, melamine or polycarboxylate.

The preferred types of self-leveling cement are Portland cement (especially CEM I 32 5 R), composite cement (CEM II), blast furnace slag cement (CEM III) or calcium aluminate cement (TSZ), always together with a sufficient amount of suitable filler and flux. embodiments

Production of a cellulose fiber AKD polycarboxylate compound. A cellulose fiber with a fiber length of 5 μm to 1000 μm in the presence of 2.0-9.0% by weight alkyl ketene dimer AKD with chain length C 16-18 at 15-115 ° C. was preferably coated. At the same time or subsequently, the product was reacted with 0.1-8.0% by weight of liquid polycarboxylate. This gives a crude white hydrophobic cellulose fiber with a bulk density of 160-172 g / l and 93% of dry matter, which has about 1-22% sieve residue to 100 μm (air jet sieve), with a fiber length of 100-300 μm. The fiber is suitable for the stabilization of self-leveling compounds and self-leveling screeds.

1) Testing of the cellulose fiber AKD polycarboxylate compound in the cementitious screed, polycarboxylate-modified. 0.25% by weight of hydrophobic cellulose fiber

Compound together with 33.25 wt.% Cement CEM I 32 5 R, 41, 40 wt.% Coarse quartz sand 0.5-1 2 mm, 23.20 wt.% Fine quartz sand 0.1-0.3 mm , 0.70 wt .-% polycarboxylate "Woerment FM 787 (BASF) and 1, 20 wt .-% dispersion powder used in the liquid screed, with a maximum of 5 cm layer thickness.The screed has water cement factor w / z <0.48 42 to 49 cm and is laid floating, to determine the exact w / c factor, add the flux in half of the required mixing water, then add more mixing water until the processing viscosity is reached.

Segregation of the cement paste and the formation of microcracks is largely prevented at 3 -5 cm layer thickness. The screed mass is processable for about 30 minutes, the open time is unchanged or slightly prolonged compared to the 0 pattern. The Shore A hardness is after 8 hours at 20 ⁰ C and 80% r. F. About 74 (walk-in) and after 24 hours about 88. 2) Testing of cellulose fiber AKD-polycarboxylate compound in cementitious

Screed, melamine-modified.

It was 0.25 wt .-% hydrophobic cellulose fiber compound according to the invention together with 33.25 wt .-% cement CEM I 32 5 R, 41, 40 wt .-% coarse quartz sand 0.5-1, 2 mm, 23, 20 wt .-% of fine quartz sand 0.1-0.3 mm, 0.70 wt .-% melamine "Melment F 217 G" (BASF) and 1, 20 wt .-% dispersion powder used in the liquid screed, with a maximum of 5 cm Layer thickness The screed has a water-cement factor w / z <0.48, a sufficient spreading dimension of 39 to 47 cm and is laid floating. Segregaton of the cement paste and the formation of microcracks is largely suppressed at a layer thickness of 3 to 5 cm. The screed mass is processable for about 20 minutes, the open time is unchanged or slightly prolonged compared to the 0 pattern. The Shore A hardness is after 16 hours at 20 ⁰ C and 80% r. F. About 73 (walkable) and after 32 hours about 86.

Cement-based self-leveling compounds and flow screeds according to the invention contain cement, spherical quartz filler (s), superplasticizers based on polycarboxylate or melamine, stabilizing agents such as hydrophobic superplasticizer-containing cellulose fiber according to the invention and further additives such as dispersion powder and defoamer. In the case of calcium aluminum cement screed, no flow agent is needed, but a sulfate carrier and again the modified cellulose fiber.

A hydrophobic cellulose does not sufficiently fulfill the self-running properties in the cement. Cellulosic fibers that are only fluxed require additional make-up water, which worsens cement strength. The combination of cellulose with hydrophobing and plasticizer, however, meets the requirements; the product is a stabilizer and viscosifier for self-leveling soil leveling compounds, flow screeds, grouting mortars, repair mortars and thin-layer quick cements:

- hydrophobic and compatible with all commercially available superplasticizers Water-cement factor usually does not need to be adjusted to prevent bleeding, segregation, sanding and micro-cracks, which promotes deaeration and reduces the air-entrained pores, allowing homogeneous cement hardening and improved microstructure

Starting formulation:

^* depending on the filler used, the flux and the dispersion powder

3) Testing of the cellulose fiber AKD polycarboxylate compound in the thin-layer rapid cement.

0.25% by weight of hydrophobic cellulose fiber compound according to the invention together with 39.50% by weight of cement CEM I 32 5 R, 55.65% by weight screed fine filler 0.08-1, 4 mm, 1, 10 wt .-% polycarboxylate Woerment FM 787 (BASF) and 3.50 wt .-% dispersion powder used in rapid cement, at maximum 0.9 cm layer thickness. The fast cement contains aluminate for acceleration and is after 4 hours at 20 ⁰ C and 80% r. F. Dust-dry and crack-free cured.

4) Testing the Cellulose Fiber AKD Polycarboxylate Compound in a Gypsum Fibreboard Formulation.

A stucco plaster was used for 12.5 mm slabs containing less than 6% aggregate of REA and recycled gypsum and having a water-solid factor of about 0.5 Additives such as starch ethers or silicone water repellents were not used The drainage and drainage were measured on a Buchner funnel by means of a vacuum pump stand at a pressure difference of 0.7 bar.

5) Application in a lime plaster formulation

A plastic-coated lime cement plaster with 0 wt .-% and 0.5 wt .-% modified cellulose fiber BWW 45 H was applied with Smoothing trowel on commercially available sand-lime bricks (dimensions 10 x 10 x 5 cm ³ ), layer thickness 2 mm, about 35 grams of plaster per 100 cm ² . After drying, after one day with a pipette 1, 0 ml of water in the form of a drop placed on the plaster. The time [min] was stopped until the drop had run off and disappeared. The longer this time, the higher the hydrophobicity and water resistance of the plaster. In the case of a hydrophilic cleaning formulation, the drop has disappeared after 5 to 10 minutes, with the use of 0.5% by weight of BWW 45 H the drop remains standing for at least 4 hours. Furthermore, the water vapor permeability of the plaster (DIN 52615, for building and insulating materials) in the presence of 0.5 wt .-% of modified cellulose fiber BWW 45 H was increased.

Further examples:

Multifunctional cellulose-containing water-insoluble fiber which, due to hydrophobic and liquefying coatings, stabilizes, vents and homogeneously hardens the building products (self-leveling cementitious compounds,

Flow screeds, cement anhydride systems, quick cements, adhesive slips, plasters), in particular prevents the segregation and segregation of the superplasticizer with the mineral binder, reduces the air entrainment in the cement as well as the drainage, dewatering and drying of fiberboard (gypsum, anhydride, cement) improved and accelerated.

Multifunctional cellulosic water-insoluble fiber wherein, to adjust the superplasticizing properties, the fiber is coated, co-processed, mixed or charged with a plasticizer; the

Superplasticizer, for example, melamine resin, melamine sulfonate, polycarboxylate or a suitable copolymer, which is the electrostatic interaction of Particles in the cement paste controls, in an amount of from 0.1 to 50.0 wt .-%, but preferably from 1.0 to 20.0% by weight.

Multifunctional cellulose-containing water-insoluble fiber, wherein the fiber is coated, co-processed, mixed or charged with a hydrophobicizing agent to adjust the hydrophobic properties, wherein alkyl ketene dimer AKD (chain length C12, C16, C16-18 or C22) is preferred for adjusting the water-repellent properties, an alkyl or alkylene succinic acid derivative ASA or a polymer sizing agent PSA is used, furthermore alum, organosilicon compounds and also fatty acid derivatives, in an amount of 0.1-50.0 wt .-%, but preferably from 1, 0-20 , 0% by weight.

Multifunctional cellulose-containing water-insoluble fiber, fiber length, fiber diameter, degree of loading and type and amount of the hydrophobizing agent and of the flow agent permitting use for construction products, the fiber length of the cellulose being at most 4000 μm, but preferably at 5 -500 μm, the loading level being 0 - 99 wt .-% but preferably 1-50 wt .-%, the amount of fiber used at 0.01 - 5.00 wt .-%, but preferably at 0.05 - 2.00 wt .-%.

A multifunctional cellulosic water-insoluble fiber, using proportionally or exclusively a hydrophobized cellulosic fiber, a silicone paper fiber, a release paper fiber, an oil paper fiber or the like; also deinking paper, waste paper, paper sludge, (B) CTMP, wood pulp or fibers from annual plants.

Multifunctional cellulose-containing water-insoluble fiber, wherein the fiber controls viscosity, flow, plasticity, rheopexy and the yield strength of dry mortar after water addition and in ready-to-use systems; soluble components such as cellulose ethers, starch ethers, guar ethers, guar hydrolysates, welan gum, gellan, other plant ingredients (such as Example gum arabic), polycarboxylic acids, polyurethanes, polyacrylates or polyvinyl alcohols may be included as a mixture.

Multifunctional cellulose-containing water-insoluble fiber, wherein the additive is produced primarily by means of thermo-mechanical processes, wherein also mill drying, milling refining, kneading or other pretreatments of raw materials by process chemicals (such as alkali), radiation, ultrasound, enzymes or the like are not excluded.

Multifunctional cellulosic water-insoluble fiber capable of providing a single-pass application in a single operation, ensuring smooth surfaces without flow disturbances, extending the open time, preventing the formation of microcracks during the drying phase and controlling the anti-settling effect of ready-to-use systems; wherein for controlling the rheology, stability and processing further components may be included (dispersants, biocides, cement additives such as alkanolamine or polyethyleneamine, adjusting agents such as bentonite or smectite, wetting agents, defoamers, antifreeze agents, accelerators, retarders).

Multifunctional cellulose-containing water-insoluble fiber which is capable of increasing the hydrophobicity and / or the water vapor permeability of screed, coatings, leveling compounds, quick-setting cement, adhesive slurry, plaster and fiberboard; to maintain or improve the mechanical values of cementitious end products such as screed and thin coating (such as early strength, compressive strength, flexural modulus, air pore content, abrasion values, strength, notched impact strength and the like), to increase the process speed of fiberboards and / or to reduce the drying costs.

Multifunctional cellulosic water-insoluble fiber, in the form of a fiber compact, a built-up agglomerate, a microsphere, a pellet, a broken pellet, a tablet, a briquette or other was made dispersible dust reduced or dosed dosage form.

Claims

Patentansprüche1. Fiber as an additive for a construction product;

1.1 with cellulosic, water-insoluble fibers; 1.2 the surface of each fiber is either only one

Hydrophobizing agent or coated with a hydrophobing agent in combination with a flow agent.

2. Construction product, characterized by a proportion of fibers according to claim 1.

3. Construction product according to claim 2, characterized by a proportion of silicone paper fibers, release paper fibers, oil paper fibers.