EP2046875A1

EP2046875A1 - Foam stabilizer system

Info

Publication number: EP2046875A1
Application number: EP07787237A
Authority: EP
Inventors: Wilfried Hübner; Matthias Passmann; Erik Hattemer
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 2006-08-03
Filing date: 2007-07-09
Publication date: 2009-04-15
Also published as: WO2008015076A1

Abstract

The invention relates to a composition comprising at least one aqueous polymer dispersion, an N-acylamino acid derivate of the general formula (A) and/or an amide of the general formula (A'), where l, m are each an integer from 0 to 20 and the sum of l+m is an integer from 1 to 20, M+ is a monovalent counterion selected from the group of the alkali metal cations and the ammonium cation, and R1 to R6 may each independently be H or a linear or branched alkyl radical having from 1 to 20 carbon atoms, or R1 and R2 and 2 of the R3 to R6 radicals may be H or a linear or branched alkyl radical having from 1 to 20 carbon atoms, and the two others of the R3 to R6 radicals are alkylene radicals having from 1 to 20 carbon atoms and are bonded to one another via a polymer backbone, and a fatty acid salt B of a branched or unbranched, saturated or unsaturated fatty acid having a chain length of at least 10 carbon atoms, the composition being characterized in that the polymer dispersion comprises at least one polymer having a glass transition temperature of at least +25 °C.

Description

Foam stabilizer system

The present application relates to a composition comprising an aqueous polymer dispersion, an N-acylamino acid derivative and / or an amide and a fatty acid salt of a branched or unbranched, saturated or unsaturated fatty acid having a chain length of at least 10 carbon atoms and foams produced therefrom.

So far, one- or two-component polyurethane-based compositions are known which are packaged in pressure cans and applied and foamed on site at the construction site. A disadvantage of these systems are primarily the health concerns against parts of the monomers used, in particular against diisocyanate. For this reason, efforts have long been made to produce foamable compositions which have properties comparable with polyurethane foams, in particular with regard to hardness and durability, and are safer for health.

Such foamable systems (filling foams) are known from WO 98/12247 A1 and WO 98/12248 A1. These references describe water-based, foamable polymeric compositions which can be used to replace polyurethane foams. A disadvantage of these compositions, however, is that the resulting foams on the one hand dry poorly, since the water contained in these compositions evaporates only relatively slowly and also lead to relatively soft foams after curing, which is undesirable for a variety of applications in the construction sector.

Therefore, the object of the present invention was to provide a foamable polymeric composition, which on the one hand is less harmful to health than polyurethane foams and on the other hand provides relatively fast-drying and permanently stable foams.

Surprisingly, it has been found that by adding a new stabilizer system consisting of an N-acylamino acid derivative of the general formula A and / or an amide of the general formula A 'on the one hand, and a fatty acid salt B of a branched or unbranched, saturated or unsaturated fatty acid having a chain length of at least 10 carbon atoms to an aqueous polymer dispersion containing at least one polymer having a glass transition temperature of at least 10 ⁰ C, which can be overcome by the problems known from the prior art. The subject of the present application is thus a composition containing at least one aqueous polymer dispersion, an N-acylamino acid derivative of the general formula A.

and / or an amide of the general formula A '

where I, m is an integer between 0 and 20 and the sum of l + m is an integer between 1 and 20, M ^{+ is} a monovalent counterion selected from the group of alkali metal cations and the ammonium cation, and R ₁ to R ₆ each independently of one another can stand for H or a linear or branched alkyl radical having 1 to 20 C atoms, or R ₁ and R ₂ and 2 of the radicals R ₃ to R ₆ for H or a linear or branched alkyl radical having 1 to 20 C And the other two of the radicals R ₃ to R ₆ independently of one another are alkylene radicals having 1 to 20 C atoms, which are connected to one another via a polymer backbone, and a fatty acid salt B of a branched or unbranched, saturated or unsaturated fatty acid a chain length of at least 10 carbon atoms, the composition being characterized in that the polymer dispersion comprises at least one polymer having a glass transition temperature of at least +10 ⁰ C contains.

Thus, it is possible that the structures A and A 'are not incorporated as free molecules, but as a repeating unit in a polymer backbone. Such copolymers can be by Achieve copolymerization of polymerizable compounds which forms an intermediate after the copolymerization to form the structural unit A or A 'in up to three further synthetic steps, wherein R ₁ to R _{6 are} each independently H or a linear or branched alkyl radical having 1 to 20 C atoms may be or R ₁ and R ₂ and 2 of the radicals R ₃ to R _{6 is} H or a linear or branched alkyl radical having 1 to 20 carbon atoms and the other two of the radicals R ₃ to R ₆ alkylene radicals with 1 are up to 20 C-atoms, which are connected by a polymer backbone.

Suitable comonomers are in principle all monomers copolymerizable with the abovementioned compound in a polymerization. By copolymerizable is meant, in general, that two monomers in a reaction react alternately (alternately), randomly or successively with one another. In the latter case, only one monomer is consumed predominantly, then the other, so that block copolymers are formed. The mass ratio of the comonomers can be chosen largely as desired and indirectly determines the ratio of the different repeat units in the polymer.

For example, it is possible to use olefinic hydrocarbons as comonomers. Among these are ethene, propene, 1-butene, 2-butene, methylpropene, 1-propene, 2-propene, 2-methylpropene, 3-methylpropene, 1, 3-butadiene.

Another group of suitable comonomers are vinylic monomers: vinyl methyl ether, vinyl ethyl ether, vinyl acetate, vinyl pyrrolidone, vinylacetic acid, crotonic acid, or else isocrotonic acid.

Furthermore, monomers are selected from the group consisting of styrene, fumaric acid, cinnamic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, esters of acrylic or methacrylic acid with a straight-chain or branched alkyl radical having more than eight, preferably nine or ten connected carbon atoms or vinyl esters with a straight-chain or branched alkyl radical having more than eight, preferably nine or ten connected carbon atoms

It is also possible to use more than two, e.g. use three or four of the comonomers described above, which are described after the polymerization and up to three further synthetic steps by the formulas A and A, respectively. These are also represented by the formulas A and. A 'represents, but the non-backbone residues need not be identical. By this is meant that, for example, two different compounds A or A, or else a compound A with a compound A 'can be formed by the copolymerization and up to three further reactions.

Suitable monovalent counterions M ⁺ are the monovalent cations of lithium (Li ⁺ ), sodium (Na ⁺ ), potassium (K ⁺ ), rubidium (Rb ⁺ ), cesium (Cs ⁺ ) or the ammoinium cation (NH ₄ ⁺ ). However, it is also conceivable to use the compounds A or A 'as salts of di-, tri- or higher-valent cations, for example the alkaline earth elements Be ²⁺ , Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ or else Al ^{3 +} or Sn ²⁺ .

As fatty acid salts according to the invention are generally all water-soluble fatty acid salts, especially alkali metal or ammonium salts of decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonoadecane, eicosan and docosanoic in Question. This is particularly advantageous because these compositions on the one hand form foams after foaming, which retain their outer shape until they have formed a solid structure by the drying process. On the other hand, it has been found that these compounds have virtually no softening properties with respect to the polymer component, which allows the production of harder foams.

A further advantage of the composition according to the invention is the fact that foams produced from these compositions after curing are usually paintable with conventional emulsion paints. This is usually difficult with the polyurethane foams known from the prior art.

According to a preferred embodiment, at least one of the polymers contained in the polymer dispersion onto a glass transition temperature T ₉ of greater than or equal +25 ⁰ C. This is particularly advantageous because these polymers improve both the foam stability in the freshly foamed state and in the cured state.

According to a further, particularly preferred embodiment, at least one of the polymers contained in the polymer dispersion onto a glass transition temperature T ₉ of greater than or equal to +50 ⁰ C. This is particularly advantageous since such polymers form even stronger foams. A possible explanation for this could be based on the fact that the polymers of such a polymer dispersion act as solid fillers and thus a priori support the formation of a stable foam during foaming of the composition.

According to a further preferred embodiment, the polymer dispersion contains an acrylate polymer dispersion, a methacrylate polymer dispersion or that of an acrylate or methacrylate copolymer. This is particularly advantageous because very stable foams can be produced with such polymer dispersions with the stabilizer system according to the invention from A and / or A 'and B. In addition, such polymer dispersions are relatively harmless to health.

According to a further, particularly preferred embodiment of the composition according to the invention, the polymer dispersion contains a dodecyl, tetradecyl, hexadecyl, octadecyl, docosyl, isodecyl, isotridecyl, dodecyl or octadecyl acrylate or methacrylate polymer dispersion or copolymer dispersion. The polymer dispersion thus comprises dispersions of one or more aliphatic acrylic acid esters and / or methacrylic acid esters and / or such copolymers.

According to a particularly preferred embodiment, the composition according to the invention contains a styrene polymer dispersion or a styrene copolymer dispersion. This is particularly advantageous because these polymer dispersions are available at low cost, furthermore they are harmless to health and, moreover, can be produced in combination with the stabilizer system according to the invention from A and / or A 'and B long-term stable filling foams. In this case, such a styrene-containing dispersions interact with a T ₉ of 50 ⁰ C or more particularly advantageous effect on the stability of the Füllschäume. Presumably, the polymer dispersion particles act as a filler to enhance the cohesion of foams made with such polymer dispersions.

Particularly stable foams can be with polymer dispersion mixtures of styrene polymer dispersions or Styrolcopolymerdispersionen, prepared with a T ₉ of 50 ⁰ C or more and acrylate polymers, or Methacrylatpolymerdispersionen, with a T ₉ of at least 10 ⁰ C, in particular a T ₉ of at least 25 ⁰ C.

According to a further preferred embodiment, the composition according to the invention contains at least 60% by weight, in particular at least 70% by weight, of polymer dispersions. This is particularly advantageous because high polymer dispersion fractions reduce the risk of the resulting foam collapsing before curing due to the associated higher total content of polymers in the composition. For this purpose, the polymer content in the dispersions is relevant. The polymer content of a composition according to the invention is preferably above 40, in particular above 45 or 50 wt .-% based on the total composition. Although compositions with a lower polymer content or lower polymer dispersion fraction can also be foamed with the aid of the stabilizer system according to the invention, the risk that, after foaming, the foam begins to collapse during curing increases as the polymer content in the composition decreases. Although this can be compensated to a certain extent by a larger amount of the stabilizer system, but this is less economically interesting. In general, the polymer content of the composition should be as high as possible - the use of polymer dispersions having a high polymer content, for example up to 80 or 90% by weight, makes sense here. The less water the composition contains by using concentrated polymer dispersions, the shorter the curing time of a foam formed therefrom, since this - among other factors - primarily by the amount of water to be evaporated from the polymer dispersions is determined. In a further preferred embodiment, the composition according to the invention contains a fatty acid salt of a branched or unbranched, saturated or unsaturated fatty acid having a chain length of 12 to 22 carbon atoms. Particular preference is given to fatty acid salts of branched or unbranched, saturated or unsaturated fatty acids having a chain length of at least 14, in particular of at least 18 carbon atoms. Very particular preference is given to fatty acid salts of fatty acids having 14 to 20 carbon atoms. Preference is given here in particular to sodium, potassium or ammonium salts of the abovementioned fatty acids.

This is particularly advantageous since fatty acid salts of these chain lengths have good foam-forming properties without at the same time functioning as plasticizers and consequently reducing the hardness of the foams which can be prepared from the composition according to the invention. For this reason, fatty acid salts of stearic acid or palmitic acid are most preferred.

According to a further preferred embodiment of the composition according to the invention, this is white or almost white after foaming. This is of particular advantage since the polyurethane foams hitherto known from the prior art are generally yellow. Due to their low UV stability, uncovered aromatic polyurethane foams turn brown within a short time and are therefore visually less appealing overall. The foams according to the invention have a permanent UV resistance even when uncovered.

Also, the white or almost white base color of the foam facilitates the coloring with organic or inorganic dyes or pigments. In contrast to the polyurethane foams, it is not necessary first to cover a yellowish-brown intrinsic color, but it is possible to adjust the desired target color without any difficulty by adding dyes, if no white foam is desired. White foams can hardly be produced by coloring polyurethane foams - unless by selecting special but also expensive monomers.

According to a further preferred embodiment, the composition according to the invention further comprises film-forming aids, dyes, pH regulators, corrosion inhibitors, fillers, water repellents, fire retardants and / or propellant gas. Suitable film-forming aids include butyltriglycol, butyldiglycol acetate, propylene carbonate, tri- and tetraethylene glycol monomethyl ethers. The addition of these film-forming aids improves the filming of the polymer particles during drying. This improves the elasticity and / or the cohesion of the dried foams.

Suitable dyes are water-soluble, eg azo, anthraquinone, triphenylmethane, phthalocyanine dyes. The use of dyes enables the production of colored foams or the color adaptation of the foam to the background in the event that the foamed point remains visible after curing.

Suitable pH regulators are selected from the group of alkaline compounds such as ammonia or caustic soda, but also buffer systems such as the phosphate buffer (a mixture of disodium hydrogen phosphate and sodium dihydrogen phosphate) are used. The addition of pH regulators increases the storage stability of the compositions according to the invention, especially when they have been filled with propellant in pressure cans.

If the mixture according to the invention is stored in metal containers, suitable corrosion inhibitors may be added. These are available from many manufacturers. "Raybo 60 No Rust" from Raybo Chemicals Co. is particularly well suited, for example. These corrosion inhibitors prevent a reaction of the composition according to the invention with, for example, a metal can into which it has been filled prevented.

Furthermore, the compositions of the invention may contain fillers. Suitable fillers are e.g. Silica, titania, zinc oxide, siloxanes, calcium carbonate, calcium sulfate and the like.

In addition, the moisture and water repellent properties of the compositions of the invention can be further enhanced by the addition of hydrophobizing agents. These are usually neutral, slightly cationic or more cationic. By adding a small amount, for example, 1-10 wt .-%, but preferably 1, 2, 3, 4 or 5 wt .-% of the total dispersion, the foams absorb much less moisture or water.

Likewise, it may be desirable to impart fire retardant properties to the compositions of the present invention. This can be done on the one hand by the use of partially or perhalogenated polymers, on the other hand or additionally by addition of antimony oxides, brominated or chlorinated hydrocarbons, aluminum hydroxide, magnesium hydroxide, aromatic fire retardant compounds, ammonium polyphosphates or red phosphorus.

Suitable propellants are propane, n-butane, isobutane, dimethyl ether, 1, 1-difluoroethane. 1, 1, 1, 2-tetrafluoroethane and mixtures thereof. In principle, all commercially available propellant gases or mixtures can be used in order to fill the composition according to the invention as a foamable product in pressure vessels. As the sole requirement for the propellant this must not react with individual components of the composition according to the invention. However, the skilled person can determine this in simple experiments. Another object of the present invention is a foam produced by foaming a composition according to the invention with air or a propellant gas. The composition of the invention is first applied in a pressure-resistant container with a propellant or compressed air and then foamed through a nozzle. The foams thus obtained retain their volume almost constant after foaming until they are dried or hardened, and after curing have a high mechanical strength.

It is of particular advantage that the foams of the invention are long-term stable. By this is meant that the shape or the appearance, but also e.g. the strength, hardness or internal structure of the foams over one

Minimum observation period of two weeks and beyond does not change. They can be environmental influences such. Be exposed to moisture, temperature changes or wind.

Another object of the present invention is the use of the composition of the invention as a long-term stable Füllschaum, especially as a long-term stable one-component Füllschaum. The use of the composition of the invention for foaming cavities, especially in the construction sector, for example, to fill cavities between window or door soffits and masonry, is particularly advantageous because the produced from the compositions according to the invention foams quickly dry, lead to solid and long-term stable foams and health largely are harmless.

Another object of the present invention is the use of a combination of A and / or A and B as a foam stabilizer system in long-term stable Füllschäumen. The use of this foam stabilizer system according to the invention is particularly advantageous because it allows long-term stable, fast-drying filling foams to be prepared on the basis of largely polymer dispersions which are harmless to the health.

Another object of the present invention is a pressure vessel for one-component liquid systems, containing the composition according to the invention. Can be used as pressure vessel containers made of metal, plastic or other materials, which are advantageously equipped with a bleed valve, which contains a Aufschäumdüse. This is particularly advantageous because it provides an application-ready dosage form of the composition according to the invention, which is ready for use, for example, in the form of pressure cans with a tilting valve directly in place. In such pressure vessels, the composition according to the invention is moreover storage-stable for a longer period of time. measurement methods

Thermal analysis

The thermal parameters were determined by DSC (Dynamic Heat Flow Differential Calorimetry) on a Mettler Toledo DSC 821. The initial weight was 20 - 25 mg in open jars. After drying the dispersion, the crucible was sealed. The films thus formed were measured over a temperature range of -100 to +120 ⁰ C at a heating rate of 20 K / min, against an empty, also sealed crucible. The glass transition temperature T ₉ was determined from the first heating process. In this case, from a plot of the heat flow (δQ / δt [W]) against the temperature (T [ ⁰ C]) considered the stepwise offset of the trace and - graphically or arithmetically - the abscissa value of the intersection of half the height of this offset and the trace determined as the glass transition temperature T ₉ .

EXAMPLES

Raw materials:

Component 1: Styrene-butyl acrylate copolymer (KDA 168 eco, Ercros, T ₉ = 25 ⁰ C).

Component 2: polyvinyl acetate (Mowilith, Celanese, T ₉ = 31 ° C).

Component 3: Vinylidene dichloride-butyl acrylate copolymer (Solvin A50, Solvay, T ₉ = 14 ⁰ C).

Component 4: Poly (meth) acrylic acid ester (Robond H 6106, Rohm & Haas, T ₉ ~ 26 ⁰ C).

Component 5: polystyrene with a minor amount of butyl acrylate (Robond 6114, Rohm & Haas, T ₉ ^» 110 ° C).

Component 6: Methyl vinyl ether-maleic anhydride copolymer (Gantrez AN 119, CAS-RN: 9011-16-9 having a weight-average molecular weight (M _w ) of about 200 kg / mol.

Component 7: Solution of 30% by weight in acetone of a partially amidated product of the reaction of component 6 with laurylamine.

Component 8: C | | _6/18 fatty alcohol ethoxylate (Disponil TA14, HLB ca. 14) Testing

1. Foam Structure: The foam structure was determined visually. Foams with a mean bubble diameter <1 mm in diameter are considered very fine-celled.

2. Foam height: The foam height was measured by fresh foam, e.g. with a ruler, with the dried foam determined by strength measurement after cutting.

3. Drying time: The foam is considered dry if there are no damp spots during cutting.

Example 1-6: Compositions with N-acylamino acid derivatives (formula A)

manufacturing

All components are added together and homogenized for approx. 15 minutes (stirred). 95% by weight of the mixture are then introduced into an aerosol can and printed on the valve with about 4 bar of a mixture of volatile hydrocarbons. The proportion of propellant in the can is then 5 wt .-%.

TABLE 1 Compositions with N-acylamino acid derivatives (formula A)

Numbers are% by weight unless otherwise stated.

35% suspension in water * ^* Na salt (30% in water) Example 7-9: Compositions with Amides (Formula A ')

production:

All raw materials with the exception of component 7 are initially charged and homogenized for 10 minutes. Subsequently, with constant stirring, component 7 is added and stirred for a further 5-10 minutes. 95% by weight of the mixture are then introduced into an aerosol can and printed on the valve with about 4 bar of a mixture of volatile hydrocarbons. The proportion of propellant in the can is then 5 wt .-%.

Table 2: Compositions with amides (formula A ')

Numbers are% by weight unless otherwise stated.

Claims

claims

1. Composition comprising at least a) an aqueous polymer dispersion, b) an N-acylamino acid derivative of the general formula A.

and / or an amide of the general formula A '

where I, m is an integer between 0 and 20 and the sum of l + m is an integer between 1 and 20,

M ⁺ for a monovalent counterion is selected from the group of alkali metal cations and the ammonium cation

and R ₁ to R ₆ each independently of one another may be H or a linear or branched alkyl radical having 1 to 20 C atoms, or R ₁ and R ₂ and 2 of the radicals R ₃ to R _{6 may be} H or a linear or branched alkyl radical having 1 to 20 carbon atoms and the other two of the radicals R ₃ to R _{6 are} alkylene radicals having 1 to 20 carbon atoms are connected by a polymer backbone,

and

c) a fatty acid salt B of a branched or unbranched, saturated or unsaturated fatty acid having a chain length of at least 10 carbon atoms,

characterized in that the polymer dispersion contains at least one polymer having a glass transition temperature of at least +10 ⁰ C.

2. Composition according to claim 1, characterized in that at least one of the polymers contained in the polymer dispersion has a glass transition temperature T ₉ of equal to or greater than +25 ⁰ C.

3. Composition according to claim 1 or 2, characterized in that at least one of the polymers contained in the polymer dispersion has a glass transition temperature T ₉ of equal to or greater than +50 ⁰ C.

Composition according to any one of the preceding claims, characterized in that the polymer dispersion contains an acrylate polymer dispersion, a methacrylate polymer dispersion or a dispersion of an acrylate or methacrylate copolymer.

5. Composition according to one of the preceding claims, characterized in that the polymer dispersion is a dodecyl, tetradecyl, hexadecyl, octadecyl, docosyl, isodecyl, isotridecyl-acrylate or

-methacrylate dispersion, in particular a dodecyl or octadecyl acrylate or - methacrylatpolymerdispersion.

6. The composition according to any one of the preceding claims, characterized in that the polymer dispersion contains a styrene polymer dispersion or styrene copolymer dispersion.

Composition according to any one of the preceding claims, characterized in that the composition contains at least 70% by weight of polymer dispersion.

8. Composition according to one of the preceding claims, characterized in that the fatty acid salt of a branched or unbranched, saturated or unsaturated Fatty acid has a chain length of 12 to 22, especially 14 to 20 carbon atoms.

9. Composition according to one of the preceding claims, characterized in that the fatty acid salt of a branched or unbranched, saturated or unsaturated fatty acid has a chain length of at least 14, in particular of at least 16 carbon atoms.

10. The composition according to any one of the preceding claims, characterized in that the fatty acid salt B is a salt of stearic acid or palmitic acid.

11. The composition according to any one of the preceding claims, characterized in that the composition further film-forming aids, dyes, pH regulators, corrosion inhibitors, fillers, fire retardant compounds and / or propellant gas contains.

12. foam, producible by foaming a composition according to any one of the preceding claims with air or a propellant gas.

13. Use of a composition according to any one of claims 1 to 11 as a long-term stable Füllschaum, in particular as a long-term stable one-component Füllschaum.

14. Use of a combination of A and / or A and B as a foam stabilizer system in long-term stable Füllschäumen.

15. A pressure vessel for one-component liquid systems, comprising a composition according to any one of claims 1 to 11.