DE4024550A1 - Joint sealants with early resistance to rain-water - Google Patents

Abstract

Joint sealing cpds. (I) with early rain resistance are claimed, contg. aq. polymer dispersions (II) and non-ionic cellulose ethers (III) (hydroxyethyl-, hydroxyethylmethyl-, hydroxypropylmethyl-or hydroxypropyl-cellulose), with fillers and conventional additives, such as pigments, plasticisers, extenders, thickeners, foam suppressants, dispersants, pH regulators, preservatives and anti-ageing additives, as required; (I) are produced by mixing (II) with the other components, the novelty being that (III) is incorporated in retarded form as a premixed slurry with a small amt. of water. Process comprises mixing the usual additives (except the pH regulator) with (II), adding the aq. slurry of (III), then incorporating the filler and the pH regulator. (II) contain film-forming polyacrylates and/or acrylate copolymers, EVA, butadiene-styrene, vinyl acetate/maleic ester, silicone, urethane, vinyl acetate/methacrylic acid/chloroprene or -isoprene polymers or copolymers, or polysulphides. 25-90 wt.% (II) (pref. 25-40 wt.%; in highly filled prods.), 0-60 (pref. 2-60 wt.% filler, 0-1 (pref. 0.3-0.5) wt.% wetting agent, 0-20 (pref. 5-15) wt.% plasticiser, 0-10 (pref. 4-6) wt.% other additives (e.g. thickeners, foam suppressants and pigments) and up to 1.5 wt.% (III).

Description

The invention relates to early rainproof joint sealants

• - aqueous polymer dispersions (I)
• - Non-ionic cellulose ether (II) from that of hydroxyethyl, Hydroxyethylmethyl, hydroxypropylmethyl and hydroxypropylcel lulose formed group as well
• - If necessary, conventional additives such as fillers, pigments, soft makers, extenders, thickeners, defoamers, dispersants tools, pH regulators as well as preservation and aging protective means

and can be produced by intimately mixing (I) with the other Be components and a method for producing such joints sealants and their use.

Joint sealants are known to the expert and have in the Proven in practice. The use of joint seals is problematic in areas where there is a possibility or risk that  the joint sealant before curing a water load z. B. exposed to water or rain. So many of the joint sealants used so far in the outdoor area a heavy downpour that started shortly after they were applied or partially washed out. From DE 38 14 078-A-1 the Ver Use of non-ionic cellulose ethers in joint sealing or loading coating compositions based on acrylic dispersions known. By the use of certain cellulose ethers in these compositions is said to Wash-out behavior due to the action of water such as rain water and the smoothing behavior can be improved. The used there Amounts of the specified cellulose ether types are on the solid content of the acrylic dispersion. There is no explicit statement about the ratio of "free" water to the cellulose ethers makes. The examples show that they are listed there components for the production of a joint sealant in one Planetary mixers were made, but no information can be found in what form and order the individual components are mixed together.

However, it has been found in practice that with such early rainproof joint sealants adding the individual stock parts and their shape in the manufacture of joint sealants is not arbitrary. For example, the Cel Small quantities of lulose ether in some poly on a laboratory scale Sprinkle and dissolve mer dispersions, but not in production scale and not in quantities related to the "free" Water are too large to achieve a complete solution. At Such an attempt will inevitably result in clumping or Breaking the dispersion. Although it is sometimes possible, the Cel Homogenizing lulose ether clumps again is not a good thing bar once again to disperse coagulated dispersion particles. DE 38 14 078-A-1 also offers the skilled person no indication that that such early rainproof joint sealants with other water  gene polymer dispersions as the acrylic dispersions specified there are producible.

Non-ionic cellulose ethers are also found as components of Be Layering compounds and paints known z. B. those based of aqueous dispersions of organopolysiloxanes as in the DE 12 84 007 or those based on vinyl acetate / Maleic acid dibutyl ester dispersions as in DE 21 08 365 be wrote. However, the person skilled in the art cannot derive any information from this, that such cellulose ethers also for joint sealants cher polymer dispersion base are suitable and to the desired Effects.

In the journal Resin Review 35.2 is a roof coating mass described as a binder a polyacrylate dispersion and in addition to fillers and other auxiliaries also hydroxyethyl contains cellulose as a thickener. This coating mass is advertised as particularly wash-resistant. This attribute However, the specific setting behavior of the specifically for such coating compositions developed and used poly acrylic emulsions returned. So it has not for the expert nearby, hydroxyethyl cellulose to improve the early rain use strength in joint sealants.

In addition, coating compositions do not meet the requirements that be placed on joint sealants. These are especially An requirements as defined by DIN 52 456 "Determination of processing availability of sealants "and DIN 52 454" durability "ge be asked.

Especially when it comes to durability, joint sealants have to be counteracted have the property over the coating compositions, from a  filled with this mass U-profile, which after filling in the Is vertical, not or only slightly expire. Coating compounds are generally low-viscosity because they on the one hand, should be applicable by spraying or rolling and on the other hand, a certain course for leveling the mass should. Adhesive sealants can also be coated In principle, manufac turing compounds are made from the same ingredients, it should also be possible to dilute a joint seal mass to produce a reasonably usable coating mass, but Conversions cannot necessarily be drawn in reverse pull.

From Ullmann, Encyclopedia of Technical Chemistry, 4th edition, volume 9, Verlag Chemie, Weinheim / Bergstrasse 1974, pages 208-209 known that nonionic cellulose ether derivatives such as hydroxyethyl cellulose (HEC), hydroxyethyl methyl cellulose (HEMC) and hydroxy propyl-methylcellulose (HPMC) in plastic plasters and dispersions colors and a. to improve water retention, the Of time, wet grip and thickening and setting behavior be set. However, the expert can give no indication of this see that such cellulose ethers in jointing compounds an improvement in spreadability, smoothing behavior and Splash water resistance of the not yet hardened surfaces of these masses lead. Furthermore, paints such as Emulsion paints as well as plastic mortar another area of Technology that is not comparable to joint sealants. So plastic plasters can possibly be used to fill Use joints, but generally have no pronounced Sealing properties and can be in contrast to the Fu Use the trowel to portion the sealants when applied and process.

The object of the invention is to provide joint sealants based on To provide polymer dispersions in addition to a good one Smoothing behavior an early rain resistance of the uncured Have masses without other desirable properties such as Ela modulus of elasticity, elongation at break and resilience as well as migrati onsistance and freedom from coagulum and specks to be pregnant. It was also an object of the invention To provide methods that make it possible to add such masses to produce.

The task was solved by early sealing joint sealants containing

• aqueous polymer dispersions (I),
• - Non-ionic cellulose ether (II) from that of hydroxyethyl, Hydroxyethylmethyl, hydroxypropylmethyl and hydroxypropyl cellulose formed group as well,
• - If necessary, conventional additives such as fillers, pigments, soft makers, extenders, thickeners, defoamers, dispersants tools, pH regulators as well as preservation and aging protective means

and can be produced by intimately mixing (I) with the other Be constituents, characterized in that (II) in retarded form Slurried in small amounts of water and after slurrying is added and mixed.

The individual components of the joint sealing compound are known to the person skilled in the art known as such z. B. from DE 38 14 078-A-1. More suitable Polymer dispersions for the production of joint sealants are commercially available and / or are known to the person skilled in the art from the patent and specialist literature known for. B. from E. Flick, Construction and struc tural adhesives and sealants, Noyes Publications, Park Ridge 1988 or E. Flick, Adhesives and sealant compound formulations, Noyes Publications, Park Ridge 1978. Particularly advantageous Fugendich  tion compositions contain dispersions of films capable of forming Polyacrylates and / or acrylate copolymers. Are also advantageous Joint sealants according to the invention, which are based on dispersions of Polymers or copolymers selected from the film formation of ethylene / vinyl acetate, butadiene / styrene, vinyl acetate / maleic acid ester, silicone, urethane, vinyl acetate methacrylic acid / chloroprene and isoprene polymers or copolymers formed group. Different polymer dispersions can be combined. Polysulfide dispersions have also been found in connection with Polymers capable of film formation are particularly suitable. The one For the sake of simplicity, only polymer dispersions are used in the following text spoken.

Most of the ingredients are commercially available. So both are retar dated as well as non-retarded cellulose ether commercially available Lich. Retarded cellulose ethers are understood to be those which are in Water introduced delayed compared to the unretarded substances swell. This is e.g. B. by crosslinking with glyoxal on the Surface of the cellulose ether particles reached, such as is described in DE 24 15 556. While it was common until now, said cellulose ethers already in aqueous solution or in to bring in quantities that are already in the masses Allow the "free" water contained to dissolve smoothly the joint sealants according to the invention by a new manufacturer Development process with regard to the introduction of cellulose ethers.

The cellulose ethers suitable according to the invention are low Slurried amounts of water. Taking small amounts of water is in understood in this context that the amount of water is insufficient, to smoothly dissolve the introduced cellulose ethers. The watery Slurry must be added immediately after slurrying and be mixed in. Immediately in this context means that the slurry should be added before a clear one  Increasing viscosity or even gelling occurs. The An The swelling process of the cellulose ether suspended in water is allowed have not yet started or are not yet very advanced be. Under production conditions, times under 15 minutes, be practical, especially under 10 minutes. The specialist is this period is known as delayed swell.

The aqueous ones contained in the joint sealants of the invention Dispersions preferably have solids contents of 40 to 75, ins particularly 45 to 65% by weight. Your pH may be at least 6, in particular be 7 to 9 and will, if necessary, on set these values.

The Cellu contained in the joint sealants according to the invention Loose ethers are preferred as a 2% aqueous solution at 20 ° C visco Brookfield sites of at least 5000 mPa × s. To be favoured For example, those with a value of at least 25,000 mPa × s medium viscosity hydroxyethyl celluloses. So-called are particularly suitable called highly viscous cellulose ether types that have a corresponding Have a value of at least 70,000 mPa × s. B. highly viscous hydroxy ethyl cellulose. Commercially available high-viscosity hydroxyethyl cellulose scored z. B. as a 2% solution at 20 ° C already a viscosity of 100,000 mPa × s.

According to the manufacturer's instructions for hydroxyethyl cellulose. B. at Natrosol 250 HHR with a viscosity above 200,000 mPa × s complete solutions can no longer be achieved. With the less hy drophilic cellulose ether that can be used according to the invention Limit even lower, e.g. B. with hydroxypropyl cellulose at about 150,000 mPas or, for hydroxypropylmethyl cellulose, at about 100,000 Pas.

With a higher concentration, gel-like ones increasingly form Masses of. However, this seems to play a special role in the morning Rain resistance of the joint sealants according to the invention  play. Even if the exact connections are not clear, so can be surmised that when this solubility is exceeded limit an increasing build-up of a gel-like structure contributes that the masses even in the uncured state Water pollution such as rain cannot be washed out or can only be washed out slightly.

In this context, it is obviously the relationship of the men gene from cellulose ether to "free" water, which is crucial for is whether this solubility limit is exceeded or Not. Under "free" water here is the water content of you tion mass understood that is available to the cellulose ethers to loosen up in it. Thus, the total water content of the Joint sealant used for a corresponding calculation will. Rather, it must be taken into account that the other stock parts also require a certain amount of water, or more or tie less tightly. So are for most fillers called known water values. This is, for example, at Heavy spar 11 g water per 100 g heavy spar. For silica z. B. For the type HDK V 15 from Wacker-Chemie, values can be between Determine 350 to 400 g of water per 100 g of silica. Such Values provide the expert with an indication of which quantities "bound" water from the total water content of the sealant must subtract to get the amount of "free" water. It is therefore preferred that this amount of "free" water in relation to the Amount of the cellulose ether type used in each case is a ratio results that is above the respective solubility limit.

The situation becomes a little more complicated when the specialist does a what must take into account the need that arises when the disper gated polymers contain groups capable of salt formation. He if there is such an additional water requirement, the expert must if necessary, refer to the corresponding manufacturer information Based on empirical values estimate or through this need  approximate simple manual tests. Should be a fugitive tion mass are produced in which the solubility mentioned limit is exceeded, the addition of cellulose ethers not as usual - that is, as a solution. With the fiction According to the method, a way is shown, such joint sealing mass produce.

Furthermore, fillers can be used in the jointing compounds of the invention substances in an amount of 0 to 60, in particular 2 to 60% by weight, based on the total mass of the joint sealing compounds be. Such masses have no or very little Fillers contain a high level of transparency. Low fill Substance contents can be present especially with such masses which the fillers have an additional thickening effect like silica. If only fillers are used, these too have no additional effect, their content is usually between 35 and 60% by weight. One speaks here of highly filled masses.

According to a further advantageous embodiment of the invention contain the joint sealants chlorinated as plasticizers Hydrocarbons, especially chlorinated paraffins, and as a network medium non-ionic surfactants. Commercial chlo are preferred paraffins with a chain length of about 10 to 18 coals atoms and a chlorine content of about 40 to 70 wt .-%.

In a preferred embodiment, the joint seal contains masses

25-90% by weight polymer dispersion, especially for highly filled joint sealants
25-40% by weight polymer dispersion,
0-60 wt .-%, in particular 2 to 60 wt .-% fillers
0-1% by weight, in particular 0.3 to 0.5% by weight of wetting agent
0-20% by weight, in particular 5 to 15 plasticizers and
0-10% by weight, in particular 4 to 6% by weight, of further conventional additives such as thickeners, defoamers and pigments and up to
1.5% by weight cellulose ether
-% by weight based on the total amount -

The cellulose ether content should not be much less than 0.1% by weight. Good results are particularly evident in Fu gene sealing compounds in which, taking into account the frame pa parameters such as cellulose ether type and free water content of the Cellu loose ether content in a range of about 0.1 to 0.5 wt .-% on the Total amount is.

As already mentioned, the cellulose ethers are added before the production of the joint sealant according to the invention in one preferred embodiment slurried in small amounts of water. This ratio of cellulose ether to liquid is preferred in a range from 1: 2 to 1: 4, in particular around 1: 3. Furthermore, it is preferred to add the pH Regulators, especially the bases, only after adding the cellulose ether. This is particularly the case with retarded cellulose Ether is an advantage because retardation is quick in the basic area is canceled. On the other hand, a neutral to basic Adjustment of the joint sealants is favorable on their stabilizers effect, especially on their shear stability.

Usually in the manufacture of the joints according to the invention sealants submitted the polymer dispersion. It will then be in a preferred form of the process, the usual additives with Aus pH regulators added and mixed in. Subsequently  is mixed with the cellulose slurried in water ethers and then add the fillers mix of pH regulators.

It can also prove advantageous if the addition of the Filler only takes place after the addition of the pH regulator.

To avoid stirring in air and the formation of air bubbles In the product, stirring can be carried out under vacuum.

The joint sealants are preferably used according to mood. They are especially for use in areas Chen suitable in which they splash water, rain or other Are exposed to early water pollution.

The invention is illustrated below with the aid of preferred embodiments games explained.  

Examples

The masses described in the examples as well as further ver masses produced for the same purpose were subjected to a washout test subject, with an irrigation apparatus according to the DE 38 14 078-A-1 Fig. 1 was used; is the same apparatus shown in Fig. 2 in side view.

The irrigation equipment consisted of a housing made of transparent plastic with the dimensions: height 70 cm, width 60 cm and depth 60 cm. It comprised a housing 1 , a shower head 2 , a sample bowl 3 , a pump 4 , a floor drain 5 and a shut-off valve 6 for the drain. The sample pan consisted of a vessel measuring 7 × 7 cm and had a depth of 2.5 cm. The shower head was a conventional hand shower, such as that used for body care, and was set so that the sample was irrigated evenly. The distance between sample 3 and shower head 2 was 30 cm.

The apparatus was operated with demineralized water, whereby an overpressure of about 0.4 bar was generated by the pump. The Water flow rate was 300 l / h. Spraying with water became 5 Minutes, each 1 min after filling and smoothing the Surface of the masses to be tested. The washout (in % By weight) was determined by differential weighing before and after sprinkling Right.

The processability was measured according to DIN 52 456. One was Bore of 4 mm, a pressure of 2 bar and a test volume of 200 ml used.

The masses described in the examples were still one Tested for their smoothness behavior. This test  was carried out by 7 independently working persons in such a way that after applying a 30 cm long strand of mass to a smooth, smooth, dark surface smooth the mass with a spatula and fingers has been. The smoothness behavior was determined on a scale of 1 (= very good) to 6 (= insufficient).

example 1

The following ingredients were used in a planetary mixer mixed thoroughly for about 30 minutes:

1200 g commercial dispersion of an acrylic acid ester copolymer with approximately 55% by weight solid and free carboxy groups Trade name: Primal E 1785,
200 g polybutene as an extender,
20 g ethylene oxide adduct as wetting agent,
4 g commercially available halogenated preservative (AKTIZID TL 526),
200 g of butyl benzyl phthalate as a plasticizer
200 g water
80 g aliphatic low aromatic solvent (SHELLSOL D 60)
4 g highly viscous hydroxyethyl cellulose (NATROSOL 250 HHR)
2040 g of uncoated chalk
40 g titanium dioxide and
12 g 25% aqueous ammonia solution,

Processability according to DIN 52 456: 1000 g / min
Smoothing behavior: good
Washout: 4.3% loss

The procedure was as follows, that the dispersion was presented, then the polybutene, the ethylene oxide adduct, the preservative,  the plasticizer and most of the water and the solvent were intimately mixed together. The hydroxyethyl cellulose was slurried in the remaining water in a ratio of 1: 3 and likewise added and mixed in and stirred for 5 minutes. Subsequently the chalk and titanium dioxide were incorporated and 10 minutes stirred. After the ammonia had been added, it was again 15 minutes stirred under vacuum at 40 mbar.

Example 2

The following ingredients were used in a planetary mixer mixed intensively for about 45 minutes:

1750 g of aqueous, commercially available dispersion based on a copolymer of vinyl acetate and ethylene (approximately 60% solids), with a pH of approximately 4.5 and a viscosity of approximately 1600 mPa · s at 20 ° C (trade name: Vinnapas EP 17, Wacker),
250 g chlorine paraffin (C12-C14, 49% chlorine),
2800 g barium sulfate (trade name: Schwerspat EWO),
100 g titanium dioxide (trade name: KRONOS RN 56)
25 g sodium carbonate (technical, pure commercial goods),
25 g of ethylene oxide adduct (approximately 9.5 EO) with nonylphenol,
5 g commercially available halogenated preservative,
37 g of hydroxyethyl cellulose with a viscosity of about 100,000 mPa · s of a 2% strength aqueous solution at 20 ° C. and a hydroxyethyl group content of 55% by weight (trade name: Natrosol 250 HHR).

The procedure was such that first the polymer dispersion was laid. Then there was the ethylene oxide adduct (emulsifier) that Preservative, the titanium dioxide (pigment) and the chlorine par affine added and intimately mixed. The hydroxyethyl cellulose  was slurried in water in a ratio of 1: 3 and also admitted and the whole mixed well. It followed Mix in the sodium carbonate as a 10% aqueous solution. To the Finally, the barium sulfate (filler) was added and smoothed stirs.

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

Processability according to DIN 52 456: 2300 g / min
Smoothing behavior: good
Washout: 1% loss.

Example 3

The following ingredients were used in a planetary mixer about 40 minutes mixed thoroughly:

1400 g of aqueous, commercially available polybutyl acrylate dispersion (approximately 62% solids), a pH of 6.0-6.5, 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 µm,
200 g polybutene
12 g ethylene oxide adduct (approximately 9.5 EO) with nonylphenol,
8 g commercially available halogenated preservative,
10 g sodium carbonate (technically pure commercial goods)
146 g tap water,
20 g of hydroxyethyl cellulose with a viscosity of about 4000 mPa × s of a 1% strength aqueous solution at 20 ° C. and a hydroxyethyl group content of 55% by weight, trade name: Natrosol 250 HHR,
80 g titanium dioxide,
1008 g barium sulfate (heavy spar EWO),
1096 g calcium carbonate (Omega BLP 3 ),
20 g hydrocarbons (with a KP of 180 ° C-210 ° C like crystal oil 60),

Processability according to DIN 52 456: 2830 g / min
Smoothing behavior: good
Washout: 1.7% loss

The procedure was such that first the polymer dispersion was laid. Then there was the ethylene oxide adduct (emulsifier) that Preservative, titanium dioxide (pigment), polybutene and the crystal oil is added and intimately mixed. The hydroxyethyl cellulose was slurried in 56 g of water and added immediately and mixed it all well. The Na mixture followed trium carbonate dissolved in 90 g of water. In the end, the fillings added barium sulfate and calcium carbonate and stirred until smooth.

Claims (15)

1. Containing joint sealants resistant to early rain

• - aqueous polymer dispersions (I)
• - Non-ionic cellulose ethers (II) from the group formed by hydroxyethyl, hydroxyethylmethyl, hydroxypropylmethyl and hydroxypropyl cellulose and
• - If necessary, customary additives such as fillers, pigments, plasticizers, extenders, thickeners, defoamers, dispersants, pH regulators and preservatives and anti-aging agents

and can be prepared by intimately mixing (I) with the other constituents, characterized in that (II) slurried in slow release in small amounts of water and added and mixed in after slurrying. 2. Joint sealing compounds according to claim 1, characterized in that that they have dispersions of film-forming polyacrylics contain latates and / or acrylate copolymers. 3. Joint sealing compounds according to claim 1, characterized in that they are dispersions of polymers capable of film formation or copolymers selected from that of ethylene / vinyl acetate, Butadiene / styrene, vinyl acetate / maleic acid ester, silicone, ure than-, vinyl acetate methacrylic acid / chloroprene and isoprene poly contains mers or copolymers formed group. 4. Joint sealing compounds according to one of the preceding claims, since characterized in that it is an aqueous dispersion of poly contain sulfide polymers.   5. Joint sealing compounds according to one of the preceding claims, since characterized in that the aqueous polymer or copolymer dispersions solids contents of 40 to 75 wt .-%, in particular from 45 to 65% by weight. 6. Joint sealing compounds according to one of the preceding claims, there characterized in that cellulose ethers are contained, which in 2% aqueous solution at 20 ° C Brookfield viscosities of at least 5,000, in particular at least 25,000, preferred have at least 70,000 mPa · s. 7. Joint sealing compounds according to one of the preceding claims, there characterized in that the ratio of cellulose ethers to free water is chosen so that a complete solution of the Cellulose ether can no longer be obtained. 8. Joint sealing compounds according to one of the preceding claims, characterized in that they
25-90% by weight polymer dispersion, especially for highly filled joint sealants
25-40% by weight polymer dispersion,
0-60 wt .-% in particular 2 to 60 wt .-% fillers
0-1 wt .-% in particular 0.3 to 0.5 wt .-% wetting agent
0-20% by weight, in particular 5 to 15 plasticizers and
0-10% by weight, in particular 4 to 6% by weight, of further customary additives such as thickeners, defoamers and pigments and up to,
1.5% by weight cellulose ether
-% by weight based on the total amount -
contain. 9. Joint sealing compounds according to one of the preceding claims, there characterized in that in the manufacture of the cellulose slurry form ether in a ratio of 1: 2 to 1: 4, in particular about 1: 3, to be used in water. 10. Joint sealing compounds according to one of the preceding claims, there characterized in that the addition of the pH regulators, especially bases, after adding the cellulose ether occurs. 11. Process for the preparation of jointing compounds according to the foregoing existing claims, characterized in that the Polymerdi the usual additions except the pH regulators are mixed in, then the mixing with the cellulose ethers slurried in water and after the pH regulators are then mixed in be added. 12. The method according to the preceding claim, characterized in that that the admixture of the retarded slurried in water Cellulose ether occurs before the swell delay. 13. Process for the production of joint sealants according to claims chen 9 to 11, characterized in that the addition of the filling substance after the addition of the pH regulator. 14. Use of joint sealants as such, especially in Areas in which the joint sealants spray water or May be exposed to rain.