Polyvinylalcohol stabilised redispersing powder with fluidising properties

ES 2 298 642 T3

DESCRIPTION

Polyvinyl alcohol stabilized redispersing powders that have flow-through properties.

The invention relates to polyvinyl alcohol stabilized redispersion powders having fluidizing properties, processes for their production and their use in chemical construction products.

Polymer powders redispersible in water, stabilized with protective colloids (redispersion powders) are used as additives in compositions of building materials, for example based on cement or gypsum, to improve strength, resistance to abrasion or tensile bond strength in construction adhesives. Polyvinyl alcohol is often used as protective colloid, since this even contributes to the improvement of the fastness compared to polymers stabilized with lower molecular weight emulsifiers.

Such redispersing powders are available by drying the corresponding polymer dispersions stabilized with protective colloids, in which so-called drying aids (fogging aids) are added during drying, in order to prevent the formation of agglomerates. In EP-A 467103 water-soluble copolymers with comonomer units having carboxyl functionality are used as drying aids. DE-A 19707746 describes the use of copolymers based on ethylenically unsaturated carboxylic acids and their hydroxyalkyl esters as drying aids. From EP-A 629650 copolymers with acrylamidomethylpropanesulfonic acid units are known as fogging aids. EP-A 671435 recommends spray drying in the presence of copolymers with hydrophilic, water-soluble, salt-forming monomers.

In many cases, for the modification of the compositions of building materials, for example mortar or concrete, their flowability with redispersion powders is limited. In the case of flowable mortars such as filling compositions or self-leveling screeds, however, a flowable consistency is essential, which changes only slightly during processing. In these applications, so-called cement fluidizers are therefore used as additives. Thus, EP-A 549280 describes fluidizers based on graft copolymers having four different comonomer units: (meth) acrylic acid units, hydroxyalkyl (meth) acrylate units, (meth) acrylamide-2-methyl-propanesulfonic acid. , and (meth) acrylate containing EO groups. JP-A 59/162161 describes water-soluble copolymers containing hydroxyalkyl esters of an ethylenically unsaturated monocarboxylic acid and of ethylenically unsaturated mono- or dicarboxylic acids. From EP-A 407889 redispersion powders containing phenolsulfonic acid-formaldehyde condensation products are known for improving flowability when used in hydraulic binders. EP-A 812872 describes processes for the production of polymer powders in which compounds of this type which act as fluidizers are added as drying aids.

The invention aimed to provide polyvinyl alcohol stabilized redispersion powders, which improve the flowability of building material compositions.

Object of the invention are redispersion powders stabilized with poly (vinyl alcohol) that have fluidizing properties that can be obtained by drying aqueous dispersions stabilized with poly (vinyl alcohols) of homo- or copolymers of one or more monomers from the group comprising vinyl esters of linear or branched alkylcarboxylic acids with 1 to 18 carbon atoms, acrylic acid esters or methacrylic acid esters of branched or linear alcohols with 1 to 15 carbon atoms, dienes, olefins, vinyl aromatic compounds and vinyl halides, in the presence of a copolymer based on

a) 10 to 50% by weight of one or more monomers from the group comprising ethylenically unsaturated monocarboxylic acids, ethylenically unsaturated dicarboxylic acids and their anhydrides, which in all cases have 4 to 8 C atoms, as well as their salts,

b) 10 to 50% by weight of one or more ethylenically unsaturated compounds with sulfonic acid, sulfuric acid and phosphonic acid groups as well as their salts,

c) 220 to 80% by weight of one or more monomers from the group comprising vinyl esters of linear or branched alkylcarboxylic acids having 1 to 18 C atoms and esters of acrylic acid as well as methacrylic acid esters of branched or linear alcohols with 1 to 15 C atoms, in all cases referred to the total weight of the copolymer.

Suitable vinyl esters for the base copolymer are those of carboxylic acids having 1 to 18 C atoms. Preferred vinyl esters are vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl laurate, 1-methyl vinyl acetate, vinyl pivalate and vinyl esters of α-branched monocarboxylic acids with 9 to 13 carbon atoms, for example VeoVa9^R or VeoVa10^R (trade names of Shell). Vinyl acetate is particularly preferred.

Suitable methacrylic acid esters or acrylic acid esters are linear or branched alcohol esters with 1 to 15 C atoms such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, acrylate

ES 2 298 642 T3 of propyl, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate and norbornyl acrylate. Methyl acrylate, methyl methacrylate, n-butyl acrylate and 2-ethylhexyl acrylate are preferred.

Examples of olefins and dienes are ethylene, propylene, and 1,3-butadiene. Suitable vinyl aromatic compounds are styrene and vinyl toluene. A suitable vinyl halide is vinyl chloride.

Optionally, 0.05 to 50% by weight, preferably 1 to 10% by weight, based on the total weight of the base polymer, of auxiliary monomers can be further copolymerized. Examples of builder monomers are ethylenically unsaturated mono- and dicarboxylic acids, preferably acrylic acid, methacrylic acid, fumaric acid and maleic acid; ethylenically unsaturated carboxylic acid amides and nitriles, preferably acrylamide and acrylonitrile; mono- and diesters of fumaric acid and maleic acid such as diethyl- and diisopropylesters, as well as maleic anhydride, ethylenically unsaturated sulfonic acids or their salts, preferably vinyl sulfonic acid and 2-acrylamido-2-methylpropanesulfonic acid. Other examples are pre-crosslinkable comonomers such as multiple ethylenically unsaturated comonomers, for example divinyl adipate, diallyl maleate, allyl methacrylate or triallyl cyanurate, or post-crosslinkable comonomers, for example acrylamidoglycolic acid (AGA), methyl acrylamidoglycolic acid methyl ester (MAGME), N-methylolacrylamide (NMA), N-methylolmethacrylamide (NMMA), N-methylolacrylamide, alkyl ethers such as isobutoxyether or esters of N-methylolacrylamide, N-methylolmethacrylamide and N-methylolallylcarbamate. Epoxy functional comonomers such as glycidyl methacrylate and glycidyl acrylate are also suitable. Other examples are silicon-functional comonomers, such as acryloxypropyltri (alkoxy) - and methacryloxypropyltri (alkoxy) -silanes, vinyltrialkoxysilanes and vinylmethyldialkoxysilanes, where, as alkoxy groups, for example methoxy, ethoxy and ethoxypropylene glycol ether residues may be contained. Monomers with hydroxy or CO groups may also be mentioned, for example hydroxyalkyl esters of methacrylic acid and acrylic acid such as hydroxyethyl, hydroxypropyl or hydroxybutyl acrylate or methacrylate, as well as compounds such as diacetonecrylamide and acetylacetoxyethyl acrylate or methacrylate.

Examples of suitable homo- and copolymers are homopolymers of vinyl acetate, copolymers of vinyl acetate with ethylene, copolymers of vinyl acetate with ethylene and one or more additional vinyl esters, copolymers of vinyl acetate with ethylene and acrylic acid esters and / or methacrylic acid esters, copolymers of vinyl acetate with ethylene and vinyl chloride, styrene-acrylic acid ester copolymers, styrene-1,3-butadiene copolymers, where the polymers may further contain the mentioned adjuvant monomers.

Homopolymers of vinyl acetate are preferred; copolymers of vinyl acetate with 1 to 40% by weight of ethylene; copolymers of vinyl acetate with 1 to 40% by weight of ethylene and 1 to 50% by weight of one or more additional comonomers from the group of vinyl esters with 1 to 12 C atoms in the carboxylic acid residue such as vinyl propionate, vinyl laurate, vinyl esters of alpha-branched carboxylic acids with 9 to 13 carbon atoms such as VeoVa9, VeoVa10, VeoVa11;

vinyl acetate copolymers, 1 to 40% by weight of ethylene and preferably 1 to 60% by weight of acrylic acid esters and / or methacrylic acid esters of linear or branched alcohols with 1 to 15 C atoms, particularly acrylate of n -butyl and / or 2-ethylhexyl acrylate and / or methyl methacrylate; and copolymers with 30 to 75% by weight of vinyl acetate, 1 to 30% by weight of vinyl laurate or vinyl esters of an alpha-branched carboxylic acid with 9 to 11 carbon atoms, as well as 1 to 30% by weight of esters acrylic acid of linear or branched alcohols with 1 to 15 C atoms, particularly n-butyl acrylate or 2-ethylhexyl acrylate, further containing 1 to 40% by weight of ethylene;

vinyl acetate copolymers, 1 to 40% by weight of ethylene and 1 to 60% by weight of vinyl chloride; where the polymers can further contain the mentioned adjuvant monomers in the mentioned amounts, and the weight percentage data is added to give in all cases 100% by weight.

Also preferred are copolymers of n-butyl acrylate or 2-ethylhexyl acrylate or copolymers of methyl methacrylate with n-butyl acrylate and / or 2-ethylhexyl acrylate;

styrene-acrylic acid ester copolymers with one or more monomers of the group methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate;

vinyl acetate-acrylic acid ester copolymers with one or more monomers of the group methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate and optionally ethylene;

styrene-1,3-butadiene copolymers;

wherein the polymers may further contain the mentioned builder monomers in the amounts mentioned, and the weight percent data is added in all cases to give 100% by weight.

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The choice of the monomers or the choice of the proportions by weight of the comonomers is carried out in such a way that a glass transition temperature Tg of from -50 ° C to + 50 ° C, preferably -30 ° C to +, generally results. 40 ° C. The glass transition temperature Tg of the polymers can be determined in a known manner by Differential Scanning Calorimetry (DSC). The Tg value can also be roughly precalculated by means of the Fox equation. According to Fox TG, Bull. A.M. Physics Soc. 1, 3, page 123 (1956), it is fulfilled: 1 / Tg = x1 / Tg1 + x2 / Tg2 + ... + xn / Tgn, where xn represents the fraction by weight (% weight / 100) of the monomer n, and Tgn is the glass transition temperature in degrees Kelvin of the homopolymer of monomer n. Tg values ​​for homopolymers are presented in Polymer Handbook, 2^to edition, J. Wiley & Sons, New York (1975).

Suitable polyvinyl alcohols are partially or fully saponified polyvinyl alcohols. Partially or fully saponified polyvinyl alcohols with a degree of hydrolysis of 80 to 100 mol% are preferred, especially partially saponified polyvinyl alcohols with a degree of hydrolysis of 80 to 95 mol% and a Hoppler viscosity, in aqueous solution 4%, 1 to 30 mPas (method according to Hoppler at 20 ° C, DIN 53015). Partially saponified, hydrophobically modified polyvinyl alcohols with a degree of hydrolysis of 80 to 95 mol% and a Hoppler viscosity, in 4% aqueous solution, of 1 to 30 mPas are also preferred. Examples of these are partially saponified copolymers of vinyl acetate with hydrophobic comonomers such as isopropenyl acetate, vinyl pivalate, vinyl ethylhexanoate, vinyl esters of alpha-branched saturated monocarboxylic acids with 5 or 9 to 11 carbon atoms, dialkyl maleates and fumarates. of dialkyl such as diisopropyl maleate and diisopropyl fumarate, vinyl chloride, vinyl alkyl ethers such as vinyl butyl ether, olefins such as ethylene and decene. The content of the hydrophobic units is preferably 0.1 to 10% by weight, based on the total weight of the partially saponified polyvinyl alcohol. Mixtures of the polyvinyl alcohols mentioned can also be used.

In most cases, polyvinyl alcohols with a degree of hydrolysis of 85 to 94 mol% and a Hoppler viscosity, in 4% aqueous solution, of 3 to 15 mPas (method according to Hoppler at 20 ° C, DIN 53015). The polyvinyl alcohols mentioned are available by processes known to those skilled in the art and are generally added during the polymerization in a total amount of 1 to 20% by weight, based on the total weight of the monomers.

The production of the polyvinyl alcohol stabilized polymer dispersions can be carried out by processes known to those skilled in the art, for example preferably radically initiated emulsion polymerization, described in DE-A 10253046.

The copolymer acting as fluidizer preferably contains as comonomer a) one or more monomers from the group comprising acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, as well as the salts of the mentioned carboxylic acids.

Preferred monomers b) are vinyl sulfonic acid and its alkali and alkaline earth metal salts, styrene sulfonic acid and its alkali and alkaline earth metal salts, methallylsulfonic acid and its alkali and alkaline earth metal salts, b-methallyloxyphenyl sulfonic acid and its alkali metal salts. and alkaline earth, and sulfonic acids of the general formula CH₂= CR¹ -CO-X-CR²R³-R⁴-SO3H and its alkali and alkaline earth metal salts, where X = O or NH, and R¹, R² and R³ are the same or different and have the meaning of H and C1 to C alkyl₃, and R⁴ is C alkylene₁ BC₄. Vinyl sulfonic acid, sulfopropyl (meth) acrylate, 2-acrylamido-2-methylpropanesulfonic acid and methallylsulfonic acid as well as their alkali and alkaline earth metal salts are particularly preferred.

Preferred comonomers c) are from the group of vinyl esters, vinyl acetate and vinyl propionate. Preferred methacrylic acid or acrylic acid esters are methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, and 2- acrylate. ethylhexyl.

The proportion of comonomer units a) is 10 to 50% by weight, preferably 10 to 30% by weight, in all cases based on the total weight of the copolymer. The proportion of comonomer units b) is 10 to 50% by weight, preferably 10 to 30% by weight, in all cases based on the total weight of the copolymer. The proportion of the comonomer units c) is 20 to 80% by weight, preferably 30 to 70% by weight, in all cases based on the total weight of the copolymer. The copolymer has a number average molecular weight Mn of less than 50,000 Dalton, preferably 5,000 to 20,000 Dalton.

The proportion of the copolymer acting as a flow agent in the redispersing powder is 0.1 to 25% by weight, preferably 2 to 20% by weight, based on the polymeric ingredients of the redispersing powder.

For the production of the redispersion powders, the aqueous dispersions stabilized with polyvinyl alcohol are dried together with the copolymer acting as fluidizer, for example by fluidized bed drying, lyophilization or spray drying. Preferably the dispersions are spray dried, particularly preferably after the addition of an additional amount of polyvinyl alcohol as a fogging aid. The spray drying is carried out in this case in conventional spray drying installations, where the atomization can be carried out by means of nozzles of one, two or more materials or with a rotating disk. The outlet temperature is generally selected in the range of 45 ° C to 120 ° C, preferably 60 ° C to 90 ° C, depending on the installation, the Tg value of the resin and the desired degree of drying.

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Polyvinyl alcohol is generally used as nebulisation aid in an amount such that the total amount of polyvinyl alcohol before the drying process amounts to 3 to 25% by weight, based on the polymer content; preferably 5 to 20% by weight are used, based on the polymer content. Suitable and preferred as fogging aids are the polyvinyl alcohols listed above as suitable and preferred protective colloids.

In the case of nebulization, a content of up to 1.5% by weight of antifoam agent, based on the base polymer, has been found to be favorable. To increase the storage susceptibility by improving blocking stability, particularly in the case of powders with comparatively low glass transition temperature, the powder obtained can be sized with an antiblocking agent (anticaking agent), preferably up to 30% by weight, referred to the total weight of the polymeric ingredients. Examples of antiblocking agents are Ca or Mg carbonate, talc, gypsum, silica, kaolins and silicates with particle sizes preferably in the range of 10 nm to 10 μιη. The viscosity of the feed to be nebulized will be adjusted by the solids content, in such a way that a value <500 mPas is obtained (Brookfield viscosity at 20 revolutions and 23 ° C), preferably <250 mPas. The solids content of the dispersion to be nebulized is> 35%, preferably> 40%.

To improve the technical properties of application, other additives can be added during the nebulization. Other ingredients of the dispersion powder formulations contained in preferred embodiments are, for example, pigments, fillers, foam stabilizers, and hydrophobicizing agents.

The water-redispersible polymer powder formulations obtained in this way can be used in typical fields of application for them. For example in chemical products for construction, optionally in association with hydraulic setting binders such as cements (Portland, aluminate, pozzolanic, iron and steel, magnesia or phosphate cement), or gypsum, lime and water glass, for the production of building adhesives, particularly tile adhesives and full thermal insulation adhesives, plasters, ordinary plaster compositions, pavement plaster compositions, leveling compositions, waterproofing grouts, joint mortars and paints. Particularly preferably in compositions for self-leveling floors and flowable underlays.

Typical recipes for self-leveling hydraulic setting compositions contain:

100 to 500 parts by weight of cement such as portland cement and / or clay cement,

300 to 800 parts by weight of fillers such as sand and / or limestone dust or fine silica dust and / or fly ash, to 200 parts by weight of anhydrite, hemihydrate and / or gypsum, to 50 parts by weight of calcium hydroxide , to 5 parts by weight of defoamers,

0.5 to 10 parts by weight of dispersing agents, to 100 parts by weight of redispersing powders,

0.5 to 5 parts by weight of retardants such as tartaric acid, citric acid or saccharides,

0.5 to 5 parts by weight of accelerators, for example alkali carbonates,

0.2 to 3 parts by weight of thickeners such as cellulose ethers, where the parts by weight are added to give 1000 parts by weight, and the dry mix is ​​kneaded with the corresponding amount of water depending on the desired consistency.

With the redispersion powders according to the invention it is no longer necessary to use additional thinners in the application for self-leveling plaster compositions (SVM). Surprisingly, it has been found that during the simultaneous spray drying of the dispersion stabilized with polyvinyl alcohol and the thinner a marked increase in the fluidizing effect is observed. Additionally, it has been found that powders stabilized with polyvinyl alcohol, which had not been modified according to the invention, but with the usual fluidizers, which contain high proportions of ethylene oxide or propylene oxide units, give powders of redispersible poorly redispersible and not blocking stable, not suitable for use in construction chemicals.

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Examples

The redispersion powders produced by spray drying were tested according to the recipe for the self-leveling compositions indicated in Table 1. The individual components were dry mixed and then kneaded with 21 g of water per 100 g of dry mix.

TABLE 1

<td>Quantity (g)</td><td>Raw material</td><td>Manufacturer / supplier</td>

<td> 94,0</td><td>Cement fondue melted with clay soil</td><td>Lafarge Aluminates Int.</td>

<td> 200,0</td><td>Portland Cement CEM 142.5 R</td><td>Milke-Zement GmbH &amp; Co. KG</td>

<td> 47,0</td><td>Anhydrite</td><td>Hilliges Gipswerke KG</td>

<td> 47,0</td><td>Light spar</td><td>W. Priem &amp; Co.</td>

<td> 359,0</td><td>Quartz sand H 33</td><td>Quarzwerke GmbH</td>

<td> 226,3</td><td>Calcium carbonate Omyacarb 20 BG</td><td>Omya GmbH</td>

<td> 23,0</td><td>RD / fluidizing powder</td><td></td>

<td> 1,2</td><td>Tartaric acid</td><td>Merck Eurolab GmbH</td>

<td> 1,0</td><td>LÍ2CO3</td><td>Merck Eurolab GmbH</td>

<td> 1,0</td><td>Defoamer, Agitan P 800</td><td>Münzing Chemie GmbH</td>

<td> 0,5</td><td>Cellulose, Tylose H 300 P2</td><td>Clariant GmbH</td>

<td> 1000,0</td><td></td><td></td>

Comparative Example 1 parts by weight of a redispersion powder based on a vinyl acetate / ethylene copolymer with a Tg value of 17 ° C and with 8% by weight of partially saponified polyvinyl alcohol were previously mixed with 3 parts by weight of Melflux 1641 (Degussa powder fluidizer), and tested according to the above recipe. The results are collected in Table 2.

Comparative Example 2 parts by weight of a redispersing powder, produced by nebulizing an aqueous polymer dispersion based on a vinyl acetate / ethylene copolymer with a Tg value of 17 ° C, with 8% by weight of polyvinyl alcohol partially saponified, and with 10% by weight of Melflux 1641, were tested according to the above recipe. The results are collected in Table 2.

Example 3 parts by weight of a redispersion powder produced by spraying an aqueous polymer dispersion based on a vinyl acetate / ethylene copolymer stabilized with 8% by weight of partially saponified polyvinyl alcohol with a Tg value of 17 ° C , with 5% by weight of partially saponified polyvinyl alcohol and with 7.4% by weight of fluidizer A (copolymer based on 22% by weight of methacrylic acid, 49% by weight of ethyl acrylate, 7% by weight of methyl methacrylate, 22% by weight of sulfopropyl acrylate), were tested according to the above recipe. The results are collected in Table 2.

Example 4

Analogously to Example 3, except that instead of 7.4% by weight of fluidizer A, 6.7% by weight of fluidizer B were sprayed together (copolymer based on 27% by weight of methacrylic acid, 49% by weight of acrylic acrylate). ethyl, 7% by weight of methyl methacrylate and 17% by weight of sulfopropyl acrylate). The results are collected in Table 2.

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Example 5

Analogous to Example 3, except that instead of 7.4% by weight of fluidizer A, 10% by weight of fluidizer A was co-nebulized. The results are shown in Table 2.

Comparative Example 6 parts by weight of a redispersion powder based on a vinyl acetate / ethylene copolymer with a Tg value of 17 ° C and with 8% by weight of partially saponified polyvinyl alcohol were previously mixed with 3 parts by weight of fluidizer A, and were tested according to the previous recipe. The results are collected in Table 2.

Comparative Example 7 parts by weight of a redispersion powder based on a vinyl acetate / ethylene copolymer with a Tg value of 17 ° C and with 8% by weight of partially saponified polyvinyl alcohol were previously mixed with 3 parts by weight of fluidizer B, and were tested according to the previous recipe. The results are collected in Table 2.

Example 8 parts by weight of a redispersing powder, produced by nebulizing an aqueous polymer dispersion based on a vinyl acetate / ethylene / VeoVa10 copolymer stabilized with 8% by weight of partially saponified poly (vinyl alcohol), with a Tg value of 5 ° C, with 5% by weight of partially saponified polyvinyl alcohol and 10% by weight of fluidizer A were tested according to the above recipe. The results are collected in Table 2.

Technical application tests

Determination of cake dimensions (dispersion)

The determination of the flow behavior was carried out according to DIN EN 12706 after a period of time of 1, 15 and 30 initially mixed.

Determination of flexural strength (BZ)

The determination of the flexural strength was carried out after one day (1 d) and 7 days (7 d) and was carried out according to prEN 13851 on prisms of 40 x 40 x 160 mm³.

Determination of compressive strength (DF)

The determination of the compressive strength was carried out after one day (1 d) and 7 days (7 d) and was carried out according to prEN 13851 on standard prisms of 40 x 40 x 160 mm³.

Determination of blocking resistance (BF)

To determine the blocking resistance, an iron tube with a screw cap was filled with the dispersion powder and then loaded with a metal ram. After loading, it was left in the drying cabinet for 16 hours at 50 ° C. After cooling to room temperature the powder was removed from the tube and the crush blocking stability of the powder was qualitatively determined. Stability to blocking was classified as follows:

1-3 = very good blocking stability

4-6 = good blocking stability

7-8 = sufficient blocking stability

9-10 = unstable to blockage, the powder was no longer able to flow after grinding.

Determination of sedimentation behavior RA

The sedimentation behavior of the redispersion serves as a measure of the redispersibility of the powder. 50% redispersions in water were produced by the application of strong shear forces.

The sedimentation behavior was then determined on dilute redispersions (solids content 0.5%), and for this 100 ml of this dispersion were introduced into a graduated tube, and the sedimentation height of the solid was measured. Data are obtained in mm of sedimentation after 24 hours. Values ​​greater than 7 indicate insufficient redispersion of the powder.

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Comparison of Comparative Example 1 with Comparative Example 2 indicates that with conventional fluidizers in the case of conebulization, only redispersion powders with a reduced fluidizing effect are obtained.

Comparison of Example 3 with Comparative Example 6, or the comparison of Example 4 with Comparative Example 7, shows that with the thinners used according to the invention in the case of conebulisation, the fluidising effect is improved.

TABLE 2

<td>Example</td><td>Dispersion 1 '[cm]</td><td>Dispersion 15 '[cm]</td><td>Dispersion 30 '[cm]</td><td>BZ 1 d / 7 d [N / mm²]</td><td>DF 1 d / 7 d [N / mm²]</td><td>BF</td><td colspan="2">RD 1 h / 24 h</td>

<td rowspan="2">Ex Comp. 1</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td> 16.0</td><td> 16.2</td><td> 16.4</td><td> 3.83/4.48</td><td> 19.64/24.37</td><td> 3</td><td> 0.2/1</td><td></td>

<td>E |. Comp. 2</td><td> 10.6</td><td> 9.8</td><td> 8.5</td><td> 3.11/4.06</td><td> 14.72/22.34</td><td> 10</td><td> &gt;7/--</td><td></td>

<td>E) .3</td><td> 16 3</td><td> 16.2</td><td> 16.1</td><td> 3.79/5.55</td><td> 19.12/24.52</td><td> 4</td><td> 0.1/1</td><td></td>

<td>Ex.4</td><td> 15.4</td><td>1S.S</td><td>16. OR</td><td>3.80 / 5.S3</td><td> 18.35/26.12</td><td> 3</td><td> 0.1/0.8</td><td></td>

<td>Ex. 5</td><td> 16 . 8</td><td> 16.3</td><td> 16.5</td><td> 4.01/5.78</td><td> 18.56/25.48</td><td> 4</td><td> 0.1/0.9</td><td></td>

<td>Ex Comp. 6</td><td> 15 . 6</td><td> 15.7</td><td> 15.4</td><td> 3.78/4.62</td><td> 17.91/24.74</td><td> 3</td><td> 0.2/1</td><td></td>

<td>Ex Comp. 7</td><td> 15.3</td><td> 15.5</td><td> 15.2</td><td> 3.78/4.63</td><td> 20.72/28.01</td><td> 3</td><td> 0.2/1</td><td></td>

<td>Ex 8</td><td> 16 . 9</td><td> 16.7</td><td> 16.7</td><td> 3.80/5.52</td><td> 17.16/23.07</td><td> 4</td><td> 0.2/1.2</td><td></td>