DE3934870C2 - Joint sealant or coating compositions based on aqueous polymer dispersions and use of nonionic cellulose ethers as additives to these compositions - Google Patents

Description

The invention relates to the use of nonionic cellulose ethers that of hydroxyethyl, hydroxyethylmethyl, hydroxypropylmethyl and Hydroxypropylcellulose formed with Brookfield viscosities in 2% aqueous solution at 20 ° C of at least 3000 mPas, as additives in an amount of 0.4 to 6.0 wt .-%, based on the solids content of Dispersion - to joint sealant and coating compositions based on aqueous Dispersions of polymers and copolymers other than Polyacrylates or acrylate copolymers, to improve the Spreadability, the smoothing behavior and the splash water resistance of not yet hardened surfaces of these masses.

From Ullmann, Enzyklopadie der technischen Chemie, 4th Edition, page 208-209, It is known that nonionic cellulose ether derivatives such as Hydroxyethyl cellulose (HEC), hydroxyethyl methyl cellulose (HEMC) and Hydroxypropylmethylcellulose (HPMC) in plastic plasters for improvement water retention capacity, open time, wet grip and Andick- Abbindverhaltens be used. Furthermore mentioned the DE-C 36 19 142 the use of water-soluble cellulose derivatives as Aids in the mechanical smoothing of not yet hardened surfaces  of pasty materials, in particular joint sealing compounds, z. B. based on Polyacrylates.

Known formulations of joint sealing and coating compounds are usually after application with smoothing water or Water / wetting agent mixtures, eg. B. according to DE-C 36 19 142, smoothed. The Application of smoothers allows the training both technically Also visually perfect connections to adjacent structures and the Leveling of defects in the surfaces of these masses. By Enrichment of the wetting agents contained in the smoothing agent is the Sliding resistance at the surface of the sealant is reduced and the Smoothing process as such allows. By the accumulation of wetting agents may, under certain conditions, contain ingredients of the recipe Surface of the masses are emulsified; because of that the composition the mass on the surface is changed, the technical Properties of the sealant are impaired. Also disadvantageous the impoverishment of constituents of the mass at the surface.

The invention further relates to joint-sealing or coating compounds which, with excellent properties such as modulus of elasticity, Elongation at break and resilience improved overall smoothness and at the same time a significantly improved migration resistance of Formulation ingredients in the surface of the masses over the known Having formulations. This task is accomplished through the use of nonionic cellulose ethers from that of hydroxyethyl, hydroxyethyl methyl, hydroxypropyl methyl and hydroxypropyl cellulose with Brookfield viscosities in 2% aqueous solution at 20 ° C of at least 3000 mPas, as additives - in an amount of from 0.4 to 6.0% by weight, based on the solids content of the dispersion - to joint sealing and Coating compositions based on aqueous dispersions of polymers and copolymers, except polyacrylates or acrylates Copolymers, to  Improvement of the spreadability and the smoothing behavior of not yet hardened surfaces of these masses dissolved.

A practical upper limit of the viscosity of the aforementioned cellulose ethers is 100,000 mPas; preferred is a viscosity in the range of 3000 to 20,000 mPas (Brookfield, 20 ° C, 2% aqueous solution).

An essential and unexpected advantage of the joint sealing or Coating compositions of the invention is further in the so-called Washout behavior, d. H. the applied and not yet dried mass remains even when exposed to splashing, z. B. Rainwater, stable for a longer period.

The dispersions to be used are those of film-forming polymers or copolymers selected from the Ethylene / vinyl acetate, butadiene / styrene, vinyl acetate / maleic ester, silicone, Urethane, vinyl acetate, methacrylic acid / chloroprene and isoprene polymers or copolymers and polysulfide polymers formed group.  

According to a preferred embodiment of the invention, the nonionic cellulose ether in an amount of 0.6 to 5.0% by weight, based on the solids content of the dispersion.

The present in the joint sealing or coating compositions of the invention aqueous dispersions of polymers or copolymers are preferred Solid contents of 40 to 75, in particular 40 to 70 wt .-%, on. Your pH Value should be at least 7, especially 8 to 9, and will, if required, set to these values.

Furthermore, in the joint sealing or coating compositions of the invention Fillers in an amount of 0 to 60, in particular 2 to 60 wt .-%, based on the total mass of the joint sealing or coating compounds, be included. Such masses, if they have no or very little Fillers contain a high temperature.  

The joint sealants or coating compounds can be used as plasticizers chlorinated hydrocarbons, in particular chlorinated paraffins, and as Wetting agents contain nonionic surfactants. Preference is given to commercial chlorinated paraffins with a chain length of 10 to 18 carbon atoms and a chlorine content of 40 to 70% by weight.

The aqueous contained in the joint sealing or coating compositions Dispersions of polymers or copolymers and optionally existing pigments, plasticizers, wetting agents, defoamers, Dispersing aids and preservatives and anti-aging agents are Commercially available products that the person skilled in the art of sealing Coating materials are known for construction purposes.

The nonionic cellulose ethers to be used according to the invention also The above specification is a commercial product.

The invention will be described below with reference to preferred Embodiments and comparative experiments explained in more detail.  

The compositions described in the examples and other masses prepared for comparison were subjected to a Auswa tion test using a sprinkler apparatus of Figure 1 was used. the same apparatus is shown in Fig. 2 in side view.

The irrigation equipment consisted of a housing made of plastic with the dimensions: height 70 cm, width 60 cm and depth 60 cm. It included a housing 1 , a shower head 2 , a sample pan 3 , a pump 4 , a bottom drain 5 and a shut-off valve 6 for the drain. The sample cup consisted of a 7x7 cm vessel and had a depth of 2.5 cm. The showerhead was a common hand shower used for personal care and adjusted to provide even irrigation of the sample. The distance between sample 3 and showerhead 2 was 30 cm.

The apparatus was operated with demineralized water, wherein the pump generates an overpressure of about 0.4 bar has been. The water flow rate was 300 l / h. The spraying with Water was left for 5 minutes, 1 minute each after filling and Smoothing the surface of the masses to be tested, vor accepted. The leaching (in% by weight) was determined by differential weighing determined before and after irrigation.

The compositions described in the examples continued subjected to a test with regard to their smoothness behavior. This test was done by 7 independent people like that performed that after applying a 30 cm long masses Strangs on a smooth, even, dark surface with the mass Spatula and fingers was smoothed. The smoothness behavior was on a grading scale from 1 (= very good) to 6 (= insufficient) assessed.  

example 1

In a planetary mixer, the following ingredients were mixed intensively for about 45 minutes:
1750 g aqueous, commercial dispersion based on a copolymer of vinyl acetate and ethylene (about 60% solids), having a pH of about 4.5 and a viscosity of about 1600 mPa · s at 20 ° C (trade name: Vinnapas EP 17, Wacker),
250 g of chlorinated paraffin (C₁₂-C₁₄, 49% chlorine),
2800 g barium sulphate (trade name: barite EWO),
100 g of titanium dioxide (trade name: KRONOS RN 56)
25 g of sodium carbonate (technical, pure merchandise),
25 g of ethylene oxide adduct (about 9.5 EO) of nonylphenol,
5 g of commercial halogenated preservative,
37 g of hydroxyethyl cellulose having a viscosity of about 100,000 mPa · s of a 2% aqueous solution at 20 ° C and a Hydroxyethylgruppengehalt of 55 wt .-% (trade name: Natrosol 250 HHR).

This mixture was filled into 310 ml cartridges and was Stable for at least one year at temperatures up to 35 ° C.

Processability according to DIN 52 465: 2300 g / min
Smoothing behavior: good
Washout: 1% loss.

Example 2

A composition was prepared according to Example 1, wherein, instead of the dispersion described there, a Copolymers of vinyl acetate and ethylene 1750 g of an aqueous, commercially available dispersion based on a copolymer Styrene and butadiene (about 64% solids) with a pH of about 10.5 and a viscosity of about 800 mPa · s at 20 ° C (trade name: Polysar 2105, Fa. Hycar) used were.

This mixture was filled into 310 ml cartridges and was Stable for at least one year at temperatures up to 35 ° C.

Processability according to DIN 52 465: 1980 g / min
Smoothing behavior: good
Washout: 1% loss.

Example 3

A composition was prepared according to Example 1, wherein, instead of the dispersion described there, a Copolymers of vinyl acetate and ethylene 1750 g of an aqueous, commercially available dispersion based on a copolymer Vinyl acetate and di-n-butyl maleate, solids content about 53%, pH 4 to 5, viscosity (Brookfield, 20 ° C., 20 rpm) 1000 to 3000 mPa · s, trade name Mowilith DM 2HB, Fa. Hoechst, were used.

The mixture was filled into 310 ml cartridges and was Stable for at least one year at temperatures up to 35 ° C.

Processability according to DIN 52 465: 2030 g / min
Smoothing behavior: good
Washout: 1% loss.

Example 4

A composition was prepared according to Example 1, wherein, instead of the dispersion described there, a Copolymers of vinyl acetate and ethylene 1750 g of an aqueous, commercial silicone emulsion (from the emulsion elastic drying, about 45% solids), a pH of about 5 and a density of about 1.0 at 20 ° C, trade name: Wacker Silicone building protection agents were used.

The mixture was filled into 319 ml cartridges and was Stable for at least one year at temperatures up to 35 ° C.

Processability according to DIN 52 465: 1790 g / min
Smoothing behavior: good
Washout: 1% loss.

Example 5

A composition was prepared according to Example 1, wherein, instead of the dispersion described there, a Copolymers of vinyl acetate and ethylene 1750 g of an aqueous, commercial dispersion of a polysulfide polymer, approximately 55% solids, pH 9 to 10, trade name: ZW 2028, Fa. Thiokol, were used.

The mixture was filled into 310 ml cartridges and was Stable for at least one year at temperatures up to 35 ° C.

Processability according to DIN 52 465: 1790 g / min
Smoothing behavior: good
Leaching: 2% loss.

Example 6

A composition was prepared according to Example 1, wherein, instead of the dispersion described there, a Copolymers of vinyl acetate and ethylene 1750 g of an aqueous, commercial dispersion of a polyurethane polymer, approximately 40% solids, pH 7.0 to 7.5, viscosity 10,000 to 18,000 mPa · s, trade name: VP-LA 3110, Henkel were.

The mixture was filled into 310 ml cartridges and was Stable for at least one year at temperatures up to 35 ° C.

Processability according to DIN 52 465: 1820 g / min
Smoothing behavior: good
Leaching: 3% loss.

Example 7

A composition was prepared according to Example 1, wherein, instead of the dispersion described there, a Copolymers of vinyl acetate and ethylene 1750 g of an aqueous, commercially available dispersion based on a polyvinyl acetate, about 50% solids, pH about 6 to 7, viscosity about 10,000 to 18,000 mPa · s (Brookfield), trade name Mowilith DRL, Hoechst.

The mixture was filled into 310 ml cartridges and was Stable for at least one year at temperatures up to 35 ° C.

Processability according to DIN 52 465: 1670 g / min
Smoothing behavior: good
Washout: 1% loss.

Example 8

A composition was prepared according to Example 1, wherein, instead of the dispersion described there, a Copolymers of vinyl acetate and ethylene 1750 g of an aqueous, commercially available dispersion based on a copolymer Chloroprene and methacrylic acid, approximately 46.5 to 48.5% Solid, pH ca. 9, trade name Neoprene Latex 115, were used.

The mixture was filled into 310 ml cartridges and was Stable for at least one year at temperatures up to 35 ° C.

Processability according to DIN 52 465: 2030 g / min
Smoothing behavior: good
Washout: 1% loss.

Example 9

A composition was prepared according to Example 1, wherein, instead of the dispersion described there, a Copolymers of vinyl acetate and ethylene 1750 g of an aqueous, commercial dispersion based on a natural rubber La tex, about 70% solids, pH about 9 to 10, commercial name Revertex standard.

This mixture was filled into 310 ml cartridges and was Stable for at least one year at temperatures up to 35 ° C.

Processability according to DIN 52 465: 1740 g / min
Smoothing behavior: good
Washout: 1% loss.

Example 10

Examples 1 to 9 were used there after replacement Hydroxyethylcellulose by a commercial Methylhydroxypropylcellulose (MHPC) with a viscosity of about 20,000 mPa · s of a 2% solution at 20 ° C after Brookfield and a hydroxypropyl group content of 3.2% by weight measured again. The ejection rates according to DIN 52 456 are comparable. The smoothing behavior is to be judged with good.

Result: Composition according to Example No., but with MHPC Leaching (in% loss) 1 1.8 2 1.0 3 1.0 4 1.4 5 2.6 6 3.0 7 1.4 8th 1.0 9 1.3

Example 11

Examples 1 to 9 were used there after replacement Hydroxyethylcellulose by a commercial Hydroxypropylcellulose (HPC) with a viscosity of about 5000 mPa · s of a 2% solution at 20 ° C according to Brookfield and a hydroxypropyl group content of 70% measured again. The Spout rates according to DIN 52 456 are comparable. The smoother Behavior is to be judged with good.

Result: Composition according to Example No., but with MHPC Leaching (in% loss) 1 2.2 2 1.9 3 2.3 4 1.3 5 2.0 6 2.5 7 1.0 8th 2.0 9 1.0

Comparative experiment A

Examples 1 to 9 were after replacing the Hydroxyethyl cellulose (HEC) by a commercial aqueous Polyacrylic acid dispersion (about 25% solids, trade name: Rohagit SD 15) again. The ejection rates after DIN 52 456 were comparable. The smoothing behavior is lacking way; the washout behavior is less favorable.

Results in the washout test: Composition according to Example No., (without HEC, with polyacrylic acid dispersion) Leaching (in% loss) 1 4 2 10 3 11 4 28 5 30 6 100 7 14 8th 4 9 16 10 6

Comparative experiment B

Examples 1 to 9 were without hydroxyethyl cellulose (HEC) (Trade name: Natrosol 250 HR). The smoothing behavior is deficient; the washout behavior is less favorable.

Results in the washout test: Composition according to Example No., (without HEC) Leaching (in% loss) 1 14 2 20 3 100 4 64 5 98 6 100 7 95 8th 7 9 90 10 7

Claims (4)

1. Use of nonionic cellulose ethers from that of hydroxyethyl-, Hydroxyethylmethyl, hydroxypropylmethyl and hydroxypropylcellulose formed Brookfield viscosities in 2% aqueous Solution at 20 ° C of at least 3000 mPas, as additives - in one Amount of 0.4 to 6.0 wt .-%, based on the solids content of Dispersion - to joint sealant and coating compounds based on aqueous dispersions of polymers and copolymers, except of polyacrylates or acrylate copolymers, for improving the Spreadability, the smoothing behavior and the splash water resistance of not yet hardened surfaces of these masses. 2. joint sealing or coating compositions, containing

• a) aqueous dispersions of polymers and copolymers, except polyacrylates or acrylate copolymers and optionally
• b) conventional additives such as pigments, wetting agents, plasticizers (extenders), defoamers, dispersants and preservatives and anti-aging agents, characterized in that they additionally
• c) nonionic cellulose ethers from the group formed by hydroxyethyl, hydroxyethyl methyl, hydroxypropylmethyl and hydroxypropylcellulose with Brookfield viscosities in 2% strength aqueous solution at 20 ° C. of at least 3000 mPas, in an amount of 0, 4 to 6.0 wt .-%, based on the solids content of the dispersion.

3. joint sealing or coating compositions according to claim 2, characterized characterized in that the nonionic cellulose ethers in an amount of From 0.6 to 5.0% by weight, based on the solids content of the dispersion, are included.   4. joint sealing or coating compositions according to one of claims 2 or 3, characterized in that the aqueous dispersions Solids contents of from 40 to 75, in particular from 40 to 70,% by weight, respectively.