Use of non-ionic cellulose ethers in grouting or coating materials

p0001The invention relates to a method for producing joint sealing compounds according to Claim first

p0002Out <nplcit id="ncit0001" npl-type="s"><text>Ullmann, Encyclopedia of Industrial Chemistry, 4th edition, page 208-209</text></nplcit>, It is known that non-ionic cellulose ether derivatives such as hydroxyethyl cellulose (HEC), hydroxyethyl methyl cellulose (HEMC) and hydroxypropyl methylcellulose (HPMC) are used in plastic teeth to improve the water retention capacity, the open time, the wet adhesion and the Andick- and setting behavior. Furthermore, the mentioned<patcit id="pcit0001" dnum="DE3619142C"><text>DE-C 36 19 142</text></patcit> the use of water-soluble cellulose derivatives as auxiliaries in mechanical smoothing of not hardened surfaces of soft materials, particularly joint sealants, eg based on polyacrylates.

p0003In the <patcit id="pcit0002" dnum="CS227522A"><text>CS-A-227522</text></patcit> describes an aqueous dispersion of polyacrylates, and vinyl polymers. It consists to 18 to 53% of water, to 18 to 40% of dispersed copolymer of 2 to 10% of ethylene glycol, about 0.15 to 0.5% of methylhydroxypropyl cellulose and, optionally to 60% of powdered inorganic fillers, and up to 7% other additives. The simultaneous addition of ethylene glycol and methyl hydroxypropyl cellulose has a synergistic effect with respect to the resistance to low temperatures. The dispersion is suitable for the production of adhesives, mastics and colors.

p0004Conventionally known formulations of joint-sealing and coating compositions are usually referred to the application with Glättwasser or water / surfactant mixtures, eg <patcit id="pcit0003" dnum="DE3619142C"><text>DE-C 36 19 142</text></patcit>Smoothed. The use of smoothing agents allows the formation of both technically and optically perfect connections to angrenzeden building structures as well as the leveling of imperfections in the surfaces of these materials. By enrichment of the smoothing agent containing the wetting agents, the sliding resistance is reduced at the surface of the sealing means and allows the smoothing process as such. By enriching wetters recipe ingredients can be emulsified at the surface of masses under certain conditions; characterized because the composition of the mass is altered at the surface, the properties of the sealant may be impaired. Another disadvantage is the depletion of components of the material on the surface may have an impact.

p0005The invention is directed to a method for producing joint sealing compounds according to Claim first The jointing compounds according to the invention exhibit an improved Gesamtglättverhalten while substantially improved resistance to migration of components of the formulation in the surface of the masses over the known formulations with excellent properties such as elastic modulus, elongation at break and resilience. The use of nonionic cellulose ethers from the group formed by hydroxyethyl, hydroxyethyl methyl, hydroxypropyl methyl cellulose and hydroxypropyl cellulose group having Brookfield viscosities in 2% aqueous solution at 20 ° C of at least 3000, especially at least 5000 mPa.s, as additives for joint-sealing compositions based on aqueous dispersions of polyacrylates or acrylate copolymers will improve the spreadability and the Glättverhaltens of not yet hardened surfaces of these masses.

p0006A significant and unexpected advantage of the joint-sealing according to the invention is reasonably still be seen in the so-called wash-out, ie the applied and not yet dried mass remains stable even when exposed to water, such as rainwater, for a longer period.

p0007According to a preferred embodiment of the invention the non-ionic cellulose ether from the by hydroxyethyl, hydroxyethyl methyl, hydroxypropyl methyl cellulose and hydroxypropyl cellulose are formed group with Brookfield viscosities in 2% aqueous solution at 20 ° C of at least 3000, especially at least 5000 mPa.s, in an amount from 0.4 to 6.0 in particular 0.6 to 5.0 wt .-%, based on the solids content of the dispersion.

p0008The present in the joint sealing masses according to the invention aqueous dispersions of polyacrylates or acrylate copolymers preferably have solids contents of 40 to 70, in particular 45 to 65 wt .-%, on. Its pH should be at least 7, in particular between 8 and 9 and is adjusted if necessary to these values.

p0009Furthermore, in the joint-inventively prepared masses fillers in an amount from 0 to 60, in particular 2 to 60 wt .-%, relative masses on the total mass of the joint-sealing, be included. Such compositions have, if they have no or very little fillers, high transparency.

p0010According to a further advantageous embodiment of the invention the joint sealing compounds according to the invention as plasticizers chlorinated hydrocarbons, in particular chlorinated paraffins, and as a wetting agent nonionic surfactants. Preference is given to commercially available chlorinated paraffins having a chain length of about 10 to 18 carbon atoms and a chlorine content of about 40 to 70 wt .-%.

p0011The masses in the joint-contained aqueous dispersions of polyacrylates or acrylate copolymers, and the optional pigments, plasticizers, wetting agents, defoamers, dispersion, preservatives and anti-aging agents are commercial products that extent the person skilled in the field of joint sealing for building are known.

p0012Also according to the invention to be used non-ionic cellulose ether of the above specifications are commercially available products.

p0013The invention is explained in more detail below based on preferred embodiments.

p0014The compositions described in the examples as well as further manufactured for comparison purposes compositions were subjected to a Auswaschungstest, wherein a watering apparatus according to <figref idrefs="f0001">Fig. 1</figref> has been used; The same apparatus is in<figref idrefs="f0001">FIG. 2</figref> shown in side view.

p0015The irrigation apparatus consisted of a housing made of transparent plastic with the dimensions: height 70 cm, width 60 cm and depth of 60 cm. It comprised a housing 1, a shower head 2, a sample tray 3, a pump 4, a bottom outlet 5 and a shut-off valve 6 for the process. The sample dish consisted of a vessel of dimensions 7 x 7 cm, and had a depth of 2.5 cm. In the shower head, it was a conventional hand-held shower, as it is used for personal hygiene and was adjusted so that a uniform sprinkling of the sample was carried out. The distance between the sample 3 and the shower head 2 was 30 cm.

p0016The apparatus was operated with demineralized water, with an overpressure of about 0.4 bar has been generated by the pump. The water flow rate was 300 l / h. The spraying with water for 5 minutes, 1 minute each after filling and smoothing the surface of the test masses made. The leaching (in wt .-%) were determined by differential weighing before and after sprinkling.

p0017The compositions described in the examples, a test was further subjected to smoothness with respect to their behavior. This test was developed by 7 independently working people carried out such that, after applying a 30 cm long mass strand on a smooth, flat, dark pad mass with a spatula and fingers has been smoothed. The smoothness behavior was (very good =) judged on a scale from 1 to 6 (worst).

example 1

p0018In a planetary mixer the following components were intensively mixed for about 45 minutes:<ul><li>1750 g of aqueous, commercial Polybutylacrylesterdispersion (approximately 62% solids), pH 8.8 to 8.5, a glass transition temperature Tg -50 ° C, a viscosity of about 250 mPa.s at 23 ° C and an average particle size of 0.4 microns,</li><li>250 g of chlorinated paraffin (C₁₂-C₁₄, 49% chlorine),</li><li>2800 g of barium sulfate (commercial product: barite EWO)</li><li>100 g of titanium dioxide (commercial product Kronos RN 56)</li><li>25 g of sodium carbonate (techn. Pure commodity)</li><li>25 g ethylene oxide (about 9.5 EO) nonylphenol,</li><li>5 g of commercially available halogenated preservative,</li><li>37 g hydroxyethyl cellulose having a viscosity of about 4000 mPa.s of a 1% aqueous solution at 20 ° C and a hydroxyethyl group content of 55 wt .-%, trade name Natrosol 250 HHR.</li></ul>

p0019This mixture was poured into 310 ml plastic cartridges and was at least one year at temperatures up to 35 ° C storage stable.<tables id="tabl0001" num="0001"><table frame="all"><tgroup cols="2" rowsep="0"><colspec colnum="1" colname="col1" colwidth="120mm" /><colspec colnum="2" colname="col2" colwidth="21mm" /><tbody><row><entry>Processability in accordance with DIN 52456 (4 mm bore, 2 bar pressure, test volume 200 ml):</entry><entry>2260 g / min</entry></row><row><entry>Smoothing behavior</entry><entry>Good</entry></row><row><entry>leaching:</entry><entry>1% loss</entry></row></tbody></tgroup></table></tables>

p0020With an addition of 50 g of the same hydroxyethylcellulose following results were found:<tables id="tabl0002" num="0002"><table frame="all"><tgroup cols="2" rowsep="0"><colspec colnum="1" colname="col1" colwidth="51mm" /><colspec colnum="2" colname="col2" colwidth="24mm" /><tbody><row><entry>Processability in accordance with DIN 52456:</entry><entry>1300 g / min</entry></row><row><entry>Smoothing behavior</entry><entry>very good</entry></row><row><entry>leaching:</entry><entry>0.3% loss</entry></row></tbody></tgroup></table></tables>

example 2

p0021strength aqueous solution 20 g of a hydroxypropyl cellulose having a viscosity of about 5000 mPa.s 2%,: In a planetary mixer the ingredients listed in Example 1 were intensively mixed for about 45 minutes, but in place of the hydroxyethyl cellulose 4000 mPa.s at 20 ° C and a hydroxypropyl 70%, trade name Klucel M were used.

p0022This mixture was poured into 310 ml plastic cartridges and was storage stable at least at temperatures up to 35 ° C.<tables id="tabl0003" num="0003"><table frame="all"><tgroup cols="2" rowsep="0"><colspec colnum="1" colname="col1" colwidth="90mm" /><colspec colnum="2" colname="col2" colwidth="21mm" /><tbody><row><entry>Processability according to DIN 52456 measured as described in Example 1:</entry><entry>2100 g / min</entry></row><row><entry>Smoothing behavior</entry><entry>Good</entry></row><row><entry>leaching:</entry><entry>5% loss</entry></row></tbody></tgroup></table></tables>

example 3

p0023In a planetary mixer the ingredients listed in Example 1 were mixed intensively for about 45 minutes, but instead of the hydroxyethyl cellulose with 4000 mPa.s: sodium 37 g of methylhydroxypropylcellulose with a viscosity of about 20,000 mPa.s a 2% aqueous solution at 20 ° C and a hydroxypropyl of 3.2 wt .-%, tradename: Culminal MHPC 20000 PR were used.

p0024This mixture was poured into 310 ml plastic cartridges and was at least one year at temperatures up to 35 ° C storage stable.<tables id="tabl0004" num="0004"><table frame="all"><tgroup cols="2" rowsep="0"><colspec colnum="1" colname="col1" colwidth="90mm" /><colspec colnum="2" colname="col2" colwidth="24mm" /><tbody><row><entry>Processability according to DIN 52456 measured as described in Example 1:</entry><entry>2870 g / min</entry></row><row><entry>Smoothing behavior</entry><entry>Good</entry></row><row><entry>leaching:</entry><entry>3.5% loss</entry></row></tbody></tgroup></table></tables>

example 4

p0025In a planetary mixer the following components were intensively mixed for about 45 minutes. 4700 g of aqueous dispersion of a Polyacrylsäurebutylesters with small amounts of polymerized acrylonitrile (60% solids), pH about 5 - 6, 52 g ethylene oxide (about 9.5) with nonylphenol 25 g of commercially available silicone foam inhibitor KW-13 g of commercially available phenolic preservative (Parmetol®, Schülke Mayr, Hamburg) 102 g fumed silica (commercial product HDK V 15, Wacker-Chemie) 36 g ammonia solution (25%) 52 g of chlorinated paraffin (C₁₀-C₁₄, 49% chlorine) 18 g of hydroxyethyl cellulose having a viscosity of about 4000 mPa.s of a 1% aqueous solution and a hydroxyethyl group content of 55 wt .-%, trade name Natrosol 250 HHR.

p0026This mixture was poured into 310 ml plastic cartridges and was at least one year at temperatures up to 35 ° C storage stable.<tables id="tabl0005" num="0005"><table frame="all"><tgroup cols="2" rowsep="0"><colspec colnum="1" colname="col1" colwidth="90mm" /><colspec colnum="2" colname="col2" colwidth="24mm" /><tbody><row><entry>Processability according to DIN 52456, measured as in Example 1:</entry><entry>3700 g / min</entry></row><row><entry>Smoothing behavior</entry><entry>Good</entry></row><row><entry>leaching:</entry><entry>4.5% loss</entry></row></tbody></tgroup></table></tables>

example 5

p0027In a planetary mixer the following components were intensively mixed for about 45 minutes:<ul><li>2795 g of aqueous dispersion of a commercially available acrylic acid ester-styrene copolymer (about 50% solids) having a pH of about 8, a viscosity of 1200 mPa.s at 23 ° C and an average particle size of about 0.1 micron ( anionic dispersion type)</li><li>180 g of chlorinated paraffin ((C₁₀-C₁₂) Chain length, 40% chlorine)</li><li>1,600 g barium sulphate (barytes C 11, Sachtleben)</li><li>150 g of titanium dioxide (KRONOS RN 56)</li><li>5 g sodium salt of polyacrylic acid (Dispex N 40)</li><li>100 g of formalin (30% formaldehyde solution)</li><li>120 g of phthalic acid (bis-methylcyclohexanyl) ester</li><li>50 g hydroxyethyl cellulose having a viscosity of about 400 mPa.s of a 1% aqueous solution at 20 ° C and a hydroxyethyl group content of 55 wt .-%, trade name Natrosol 250 HHR.</li></ul>

p0028This mixture was poured into 310 ml plastic cartridges and was at least one year at temperatures up to 35 ° C storage stable.<tables id="tabl0006" num="0006"><table frame="all"><tgroup cols="2" rowsep="0"><colspec colnum="1" colname="col1" colwidth="90mm" /><colspec colnum="2" colname="col2" colwidth="24mm" /><tbody><row><entry>Processability according to DIN 52456 measured as described in Example 1:</entry><entry>1500 g / min</entry></row><row><entry>Smoothing behavior</entry><entry>very good</entry></row><row><entry>leaching:</entry><entry>0.5% loss</entry></row></tbody></tgroup></table></tables>

Comparative tests

p0029<ol><li>a) Example 1 was repeated with the omission of hydroxyethyl cellulose: 23% leaching</li><li>b) Example 1 was repeated, but instead of hydroxyethyl carboxylmethyl cellulose (DS 0.8, viscosity of 400 mPa.s in 2% aqueous solution was used at 20 ° C: 27% leaching</li><li>c) Example 4 was repeated with omission of hydroxyethyl cellulose: 20% washout.</li></ol>