EP0817811A1

EP0817811A1 - Cationic sheet-structure compounds, their production and their use

Info

Publication number: EP0817811A1
Application number: EP96908052A
Authority: EP
Inventors: Wolfgang Breuer; Christoph Lohr; Jörg-Dieter KLAMANN; Wolfgang Ritter
Original assignee: Henkel AG and Co KGaA
Current assignee: BASF Personal Care and Nutrition GmbH
Priority date: 1995-03-25
Filing date: 1996-03-15
Publication date: 1998-01-14
Also published as: WO1996030440A1; JPH11502878A; DE19511016A1; US6261530B1

Abstract

Described is an agent for the stabilization of halogen-containing plastics against thermal or photochemical degradation, the agent containing cationic sheet-structure compounds of the general formula (I) [M(II)xAl(OH)y](An-)z.mH2O. The agent is characterized in that it is produced by reacting an aqueous mixture of at least one source of bivalent metal ions (M(II)), at least one source of anions (An-) and crystalline aluminium hydroxide with 1 to 20 mole %, relative to the aluminium hydroxide, of alkali-metal hydroxide for between 10 and 240 minutes at a temperature between 100 and 240 °C and, without separating the solids from the aqueous phase, drying to a powder.

Description

CATIONIC LAYER JOINTS _. MANUFACTURE AND USE

The invention relates to special cationic layer compounds of the hydrotalcite type, processes for producing the same and their use as co-stabilizers for halogen-containing plastics stabilized in particular with calcium and / or zinc salts.

Halogen-containing plastics or molding compositions made from them are known to tend to degrade or decompose when exposed to heat or when exposed to ultraviolet light. To counteract this, heavy metal compounds based on lead, tin, barium and / or cadmium are conventionally used. From a work physiological point of view, however, there is a need to exchange these very effective stabilizers for less harmful substances. As an alternative to the heavy metal compounds, for example calcium and zinc soaps can be considered as stabilizers, but they do not achieve the performance of the above heavy metal compounds, so that co-stabilizers are required to increase their stabilizing effect. German patent DE-C-30 19 632 describes the use of hydrotalcites for inhibiting the thermal or ultraviolet degradation of halogen-containing thermoplastic resins. In this patent, test results are reported which show that if hydrotalcites which are readily available on the market are incorporated, for example, into vinyl chloride resins, these hydrotalcites accelerate the dechlorination of the resins when heated or even cause the resins to decompose, turn black or foam. In addition, it was found that these hydrotalcites have poor dispersibility in the resins and adversely affect the rheological properties of the resins during molding and the appearance of the molded products. These test results are attributed to the small crystal size of the usual hydrotalcites and the large BET specific surface area of at least about 50 m ² / g and the covering of the hydrotalcite particles with water. Accordingly, German patent DE-C-30 19 632 proposes hydrotalcites with a large crystal grain and with a BET specific surface area of not more than 30 m 2 / g, which may be coated with an anionic surface-active agent such as sodium stearate can be use. Resin compositions are also described in European patent application EP-A-189 899 which contain hydrotalcites with BET specific surface areas of less than 30 μm / g. From this European patent application it is known that the hydrotalcites can be modified with higher fatty acid esters, anionic surface-active agents and coupling agents of the silane or titanium types in order to improve the compatibility of the hydrotalcite with the plastic compositions. According to the cited European patent application EP-A-189 899, the hydrotalcites are to be modified by mechanical mixing of hydrotalcites with the modifying agents in pure or dissolved form. The patent DE-C-33 06 822 teaches that by reacting "active" aluminum hydroxide with magnesium hydroxide or magnesium oxide in the presence of basic magnesium carbonate as carbonate ion donor at a temperature of 50 ° C to 100 ° C and subsequent spray drying from the suspension hydrotalcite of the formula [Mg5Al2 (0H) i2_l (C03) 3 • 4 H2O can be obtained. This procedure presupposes the availability of "active" aluminum hydroxide, as can be obtained, for example, by precipitation from aluminum salt solutions and storage in gel form. Accordingly, this process requires an additional manufacturing step - the precipitation and washing out of the aluminum hydroxide gel - or makes it necessary to obtain such a gel from a manufacturer and thus to transport large amounts of water, which affects the economy of the process.

US-A-4 656 156 describes a manufacturing process for hydrotalcite, the aluminate solution of the Bayer process being used as the aluminum component. The Bayer lye is reacted with "active" magnesium oxide, as can be obtained, for example, by calcining magnesium carbonate. The use of this method makes economic sense only at those points where the Bayer liquor itself is produced, since otherwise larger amounts of water would also have to be transported.

DE-A-1592 126 describes the production of hydrotalcites from different starting materials, for example from a slurry of solid aluminum hydroxide, solid magnesium hydroxide and sodium hydrogen carbonate. The reactions are carried out in batches, and the products are separated from the water phase by filtration or by centrifugation and washed before they are dried. Filtration or centrifugation of the very finely divided reaction products and their washing out represents a technically complex and time-consuming step that has a significant influence on the manufacturing costs.

The object of the present invention was to provide co-stabilizers for halogen-containing plastics and a process for their production, which

- are compatible with calcium and / or zinc compounds,

are dispersible in halogen-containing plastics without adversely affecting their theological properties,

- are able to intercept the decomposition products of halogen-containing plastics well,

- Are inexpensive to manufacture.

The present invention relates to agents for stabilizing halogen-containing plastics against thermal or photochemical degradation, comprising cationic layer compounds of the general formula (I)

[M (H) _x Al (0H) _y ] (An) _z . mH ₂ 0 (I)

where M (U) stands for at least one divalent metal ion and A ⁿ "for an acid anion of the charge n- (n = 1, 2 or 3), and the conditions 1 <x <5, y> z, (y + nz ) = 2x + 3 and 0 <<10 apply,

characterized in that they are obtainable by mixing an aqueous mixture of at least one source of divalent metal ions (^), a source of the anions A ⁿ "and crystalline aluminum hydroxide with 1 to 20 mol%, based on aluminum hydroxide, of alkali metal hydroxide added, heated for a time between 10 and 240 minutes to a temperature between 100 and 240 ° C and dries to a powder without first separating the solid from the water phase.

The cationic layer compounds of the general formula I are known compounds, the structure and preparation of which are described, for example, by WT Reichle in Chemtec (January 1986), pages 58-63. For the purposes of the invention, preference is given to cationic layer compounds of the general formula I in which MUH represents at least one divalent metal ion selected from the group consisting of magnesium, calcium and zinc. MU ¹ ) preferably only stands for a divalent metal ion from the group mentioned and in particular for magnesium. Cationic layer compounds of the general formula I are very particularly preferred, in which A ⁿ "stands for an acid anion with the charge n selected from the anion group carbonate, hydrogen carbonate, perchlorate, acetate, nitrate, tartrate, oxalate and iodide, preferably for carbonate In the explanation of formula I above of at least one divalent metal ion, this means that different divalent metal ions can also be present side by side in the cationic layer compound. The indices x, y and z and m can be integers or fractional numbers within the Cationic layer compounds of the general formula I, in which Vli H) stands for magnesium and A ^n_ for carbonate, are particularly advantageous .. Examples of suitable cationic layer compounds are synthetic hydrotalcites, which are also referred to as basic aluminum-magnesium carbonates and generally according to that in the German A usleschrift DE-B-15 92 126 and the methods described in German Offenlegungsschriften DE-A-20 61 114 or DE-A 29 05 256 can be produced. The hydrotalcites of the formula [Mg5Al2 (0H) ιs] C03 ^• mH2θ or the are very particularly preferred Formula [Mg Äl2 (0H) i2-l (C03) • m H2O, in which m has the meaning already given.

Suitable sources of divalent metal ions are their carbonates, hydroxocarbonates, hydroxides, oxides or their water-soluble salts such as, for example, the nitrates, chlorides, sulfates or perchlorates. It is particularly preferred to choose sources of divalent metal ions that already contain the anion A ⁿ ~. In this case it is not necessary to add an additional source of these anions. For example, it is particularly preferred to use at least some of the divalent metal ions as carbonates or as hydroxocarbonates. If the source of divalent metal ions is exclusively their oxides or hydroxides, it is necessary to use an additional source of the anions A ⁿ ", for example in the form of alkali metal salts. Here are alkali metal salts of carbonic acid and / or oxo acids of halogens such as, for example perchloric acid, which can be added in amounts of 1 to 100 mol% with respect to the aluminum content of the reaction mixture, for example sodium carbonate can be added to the reaction mixture.

Crystalline aluminum hydroxide is used as the aluminum source, which is known, for example, under the name gibbsite, hydrargillite or bayerite. The gibbsite obtained in the Bayer process is preferably used. It is not necessary to use aluminum in dissolved form, for example as an aluminate solution according to US Pat. No. 4,656,156 or in "active" form, for example as a gel according to DE-C-33 06 822. In order to react the crystalline aluminum hydroxide to be used according to the invention with the source of divalent metal ions to form the cationic layer compound, temperatures in the A range between about 100 and about 240 ° C and reaction times between about 10 and about 240 minutes are required. Furthermore, it is necessary to add a catalytically effective amount of alkali metal hydroxide to the aqueous mixture before heating to the reaction temperature. The required amount of alkali metal hydroxide is about 1 to about 20 mol% based on aluminum hydroxide, preferably about 2 to about 10 mol%. For economic reasons, sodium hydroxide is preferably used as the alkali metal hydroxide, but potassium hydroxide would also be used, for example. If the amount of alkali metal hydroxide added is reduced below the lower limit according to the invention, the aluminum hydroxide is only reacted incompletely with the source of divalent metal ions to form the cationic layer compound. Amounts of alkali metal hydroxide beyond the upper limit according to the invention are not harmful to the course of the reaction, but have a disadvantageous effect on the stabilizing properties of the powder obtainable after the reaction mixture has dried.

At reaction temperatures below about 100 ° C and at Um¬ setting times of less than about 10 minutes is carried out, the formation of the cationic layer compound incomplete, Reaktions¬ above temperatures of 240 ^β C and reaction times of more than about 240 minutes bring no further advantage and thus economically disadvantageous.

The cationic layer compound formed under these conditions is obtained in powder form by drying without prior separation of the solid from the water phase. Since the complicated process step of filtering or centrifuging is not necessary as a result, this process is particularly economical. The alkali metal ions used remain here in the end product, without the stabilizing effect against the thermal degradation of halogen-containing plastics being adversely affected thereby. The form in which the alkali metal ions are present in the end product depends on the amount used, the reaction conditions and the type of drying. The alkali metal ions can be present in the powdery end product as a hydroxide, as a salt with the anion A ⁿ ", for example as a carbonate, or as an alkali metal aluminate or as an alkali metal aluminum hydroxosalz. This is insignificant for the use according to the invention. It is also not important to rule out that the alkali metal ions are incorporated into the cationic layer compound.

Cationic layer compounds which are produced by this process have a specific surface area according to BET (measured with nitrogen) of above approximately 10 m ² / g, preferably between 50 and 200 m ² / g. For the purposes of the invention, the term specific surface area according to BET corresponds to the definition in Römpp's Chemie Lexikon, Volume 1, 8th edition, 1979, page 423. The smaller BET surface areas are, for example, in the range between approximately 10 and approximately 50 m ² / g, to be preferred if no further organic additives have been added to the reaction mixture. However, if one or more of the organic additives described below are added in the preparation of the cationic layer compounds, it is preferred that the BET surface area of the powders obtained is above about 50 m ² / g. This is related to the dispersing properties of the powders obtained in the PVC matrix: If these powders do not contain an organic additive with a dispersing action, it is preferable if the powder consists of well-formed and little adhering individual crystals. In this case, the specific surface area is clearly below 50 m ² / g. Because of her in principle, better absorption capacity for the hydrogen chloride split off during the decomposition of PVC, however, powders with a specific surface area above 50 m ^{2 are} preferred. Such fine-particle powders, however, consist of microcrystals which have a strong tendency to form aggregates and which do not disperse sufficiently homogeneously in the PVC matrix. The tendency to aggregate can be reduced and thus the dispersibility in PVC can be improved if one or more of the additives described below are added to the reaction mixture at the latest before drying to a powder, but preferably before heating to the reaction temperature. Due to the improved dispersion in the PVC matrix, an increased active surface is available for binding hydrogen chloride. If one works without the addition of organic additives of the type described below, temperatures in the upper third of the temperature range according to the invention, for example between approximately 185 and approximately 240 ° C., are preferred in the production of the cationic layer compounds in order to produce products with a specific surface to get below about 50 m ² / g. If the reaction is carried out in the presence of such organic additives or if the reaction mixture is added before the reaction mixture is dried, the temperature during the production should be below about 185 ° C. in order to produce products with a specific surface area above about 50 to get m / g.

Accordingly, in a special embodiment, the invention comprises agents for stabilizing halogen-containing plastics, which additionally contain a total of about 0.5 to about 15% by weight, based on the cationic layer compound, of one or more additives selected from the following groups:

A) polyols with 3 to 30 carbon atoms and at least 2 hydroxyl groups, B) esters of partially or completely epoxidized unsaturated carboxylic acids with 6 to 22 carbon atoms,

C) full and partial esters of polyols with 3 to 30 C atoms and 2 to 12 hydroxyl groups with carboxylic acids with 6 to 22 C atoms,

D) alkyl and aryl phosphites,

E) anions of saturated or unsaturated fatty acids with 6 to 22 carbon atoms,

F) in water with pH values above 8 soluble polymers with a molecular weight of 500 to 50,000.

Additives of group A) are polyols with at least two hydroxyl groups and a total of 3 to 30 carbon atoms. Examples of such polyols are diols with 3 to 30 carbon atoms, such as butanediols, hexanediols, dodecanediols, and polyols such as trimethylolpropane, pentaerythritol, glycerol and their technical oligomer mixtures with average degrees of condensation from 2 to 10. Polyols are very particularly preferred with 3 to 30 carbon atoms which carry all 3 carbon atoms at least one hydroxyl group or an ether oxygen, preferably glycerol and / or the technical oligoglycerol mixtures with average degrees of condensation from 2 to 10. In particular, this is also the "THEIC" known tris (2-hydroxyethyl) isocyanurate (EP-B-377 428) suitable.

The additives of group B) are esters of partially or completely epoxidized unsaturated carboxylic acids with 6 to 22 carbon atoms. Suitable esters are esters of mono-, di- and / or trihydric alcohols which are completely epoxidized unsaturated carboxylic acids with 6 to 22 carbon atoms are esterified, such as methyl, 2-ethylhexyl, ethylene glycol, butanediol, neopentylglycol, glycerol and / or trimethylolpropane esters of epoxidized lauric acid, palmitoleic acid, oleic acid, ricinoleic acid, linoleic acid and / or linolenic acid. Esters of trihydric alcohols and fully epoxidized unsaturated carboxylic acids with 12 to 22 carbon atoms are preferred, and in particular esters of glycerol with fully epoxidized unsaturated carboxylic acids with 12 to 22 carbon atoms. The carboxylic acid component can be derived, for example, from palmitoleic acid, oleic acid, elaidic acid, petroselinic acid, ricinoleic acid, linolenic acid, gadoleic acid or erucic acid. The unsaturated carboxylic acids are epoxidized by known methods. As is customary in fat chemistry, the epoxidized carboxylic acid glycerides can also be technical mixtures such as those obtained by epoxidation of natural unsaturated fats and oils. Epoxidized beet oil, epoxidized unsaturated soybean oil and / or epoxidized sunflower oil of new breed is preferably used.

The additives in group C) are full or partial esters which are obtained by the relevant methods of preparative organic chemistry, for example by acid-catalyzed reaction of polyols with carboxylic acids. Suitable polyol components are those which have already been discussed in group A). Aliphatic, saturated and / or unsaturated carboxylic acids having 6 to 22 carbon atoms, such as caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, ricinoleic acid, linoleic acid, linolenic acid or behenic acid, behenic acid, are preferred as the acid component. As is customary in fat chemistry, the carboxylic acid component can also be a technical mixture, as is the case with the pressure splitting of natural ones Greasing and oiling occurs. Partial esters of glycerol and in particular of its technical oligoglycerol mixtures with average degrees of condensation of 2 to 10 and saturated and / or unsaturated aliphatic carboxylic acids with 6 to 22 carbon atoms are preferred.

Additives in group D) can be alkyl and aryl phosphites, preferably those of the general formula II

OR ³

I.

R ¹ - 0 - P - OR ² (II)

in which R 1, R ² and R ³ independently of one another represent an alkyl radical having 1 to 18 carbon atoms or a phenyl radical. Typical examples of additives of group D) are tributyl phosphite, triphenyl phosphite, dimethylphenyl phosphite and / or dimethyl stearyl phosphite. Diphenyldecylphosphite is preferred.

Additives of group E) are anions of saturated or mono- or polyunsaturated fatty acids with 6 to 22 carbon atoms, which can be linear or branched. Linear fatty acids are preferred because of their easier availability. Pure fatty acids such as, for example, lauric acid, myristic acid, palmitic acid, stearic acid, lauroleic acid, myristoleic acid, palmitoleic acid, oleic acid, linoleic acid or linolenic acid are suitable. However, it is also economically attractive to use fatty acid mixtures such as are obtainable from the splitting of natural oils and fats. It is irrelevant whether the fatty acids are used as such or as - preferably water-soluble - salts, for example as sodium or potassium salts. Since the reaction mixture is strongly alkaline, it will Reaction product which in any case contain fatty acids in the form of their anions.

Additives of group F) are polymers soluble in water with pH values above 8, preferably with pH values from 9 to 12, which have an average (number average) molecular weight of 500 to 50,000. In this context, the term “soluble” means that the polymeric additives are more than 0.01% by weight in an aqueous solution at pH 10, adjusted with alkali metal hydroxides at 20 ° C., preferably at least 0.1% by weight. -% and especially under the specified conditions are completely clear. In principle, all polymers can be used as polymeric additives which the person skilled in the art uses as pigment dispersants (see Kirk-Othmer "Encyclopedia of Chemical Technology", Vol. 7, third edition, 1979, pages 840-841 or Ull ann's "Encyclopedia of Industrial Chemistry", Vol A8, 5th Edition, 1987, pages 586-601), provided they meet the requirements of solubility and molecular weight. Preferred polymeric additives are acrylic acid and methacrylic acid homo- and copolymers, lignin sulfonates and trimer fatty acids. Particularly suitable are polymeric additives selected from the group consisting of polymers of acrylic acid and methacrylic acid and their copolymers with unsaturated monomers containing sulfonic acid groups, unsaturated monomers containing phosphonic acid groups, unsaturated aliphatic carboxylic acids with 3 to 5 carbon atoms, amides of unsaturated aliphatic carboxylic acids with 3 to 5 carbon atoms. Atoms, unsaturated monomers containing in groups and / or their salts, vinyl acetate, vinyl chloride, acrylonitrile, vinylidene chloride, 1,3-butadiene, styrene, alkylstyrenes with 1 to 4 carbon atoms in the alkyl radical. Examples of this are polyacrylic acid, polymethacrylic acid - in the following, acrylic acid and methacrylic acid and their derivatives are simplified as (meth) acrylic acid or derivatives abbreviated - and / or their salts such as polysodium (meth) acrylate, copolymers of (meth) acrylic acid with maleic acid, maleic anhydride, styrene sulfonic acid, oc-methylstyrene, 2-vinylpyridine, 1-vinylimidazole, dimethylaminopropyl (meth) acrylamide, 2- (meth) acrylamido-2-methylpropanesulfonic acid, (meth) acrylamide, N-hydroxydimethyl (metha) acrylamide and / or their salts. Very particularly preferred among the polymeric additives are those which have a predominantly anionic character, that is to say which mostly carry acid groups free or in the form of their salts. Polymers of (meth) acrylic acid and their copolymers with styrene, alkylstyrenes having 1 to 4 carbon atoms in the alkyl radical, styrene sulfonic acid, maleic acid and / or their salts, in particular their sodium salts and maleic anhydride, are particularly preferred. The polymeric additives expediently have a molecular weight of 1000 to 10000. The polymeric additives can be prepared by known processes such as bulk or solvent polymerization (see Ullmann's Encyclopedia of Industrial Chemistry, Volume 19, 4th Edition, pages 2-11, 1980). Processes for the production of lignosulfonic acid or its salts are also described in Ullmann's Encyclopedia of Technical Chemistry, Volume 16, 4th Edition, pages 254-257, 1978. Trimer fatty acids are commercially available products which are obtained as a residue in dimer fatty acid distillation, such as Pripol ^R 1040 from Unichema or Emery ^R 1000 from Emery.

The use of such additives in connection with cationic layered compounds is known from the documents WO 92/06135, WO 92/20732 and WO 92/20619.

The present invention further provides a process for the preparation of cationic layer compounds of the general formula (I) [M (") _χ Al (0H) _y ] (An) _z . MH ₂ 0 (I)

in the MOO stand for at least one divalent metal ion and A ^n_ for an acid anion of the charge n- (n = 1, 2 or 3), and the conditions 1 <x <5, y> z, (y + nz) = 2x + 3 and 0 <m <10 apply,

characterized in that an aqueous mixture of at least one source of divalent metal ions M ( ¹¹ ), a source of the anions A ⁿ "and crystalline aluminum hydroxide with 1 to 20 mol%, based on aluminum hydroxide, alkali metal hydroxide is mixed for one time is between 10 and 240 minutes to a temperature Tempe¬ heated between 100 and 240 C and ^β without Abtren¬ the solid dried from the water phase to a powder dried.

Details of the process conditions and the compounds used can be found in the preceding description.

The manufacturing process can be carried out in batches. However, it is particularly attractive to carry out the production continuously, for example in a tubular reactor. The flow rates are to be chosen so that the reaction times according to the invention are observed. The aqueous product slurry can be dried directly after leaving the pressure reactor or after intermediate storage, preferably by spray drying. Directly or indirectly heated air, a heated inert gas such as nitrogen or superheated steam can be used as the drying gas.

The drying is expediently carried out at temperatures which do not exceed the boiling point of additives A) to F) by more than 10 ° C., in particular not at all. In In some cases, additional dewatering by means of post-drying, which is advantageously carried out at temperatures between 110 ° C. to 280 ° C., for example in a drying cabinet, leads to improved cationic layer compounds according to the invention.

If desired, the cationic layer compounds obtained after the preparation can then be selected with at least one liquid or low-melting, dispersing additive selected from groups A) to F) by intensive mixing at room temperature (15 to 25 ° C.) or a temperature below that Decomposition temperatures of the cationic layer compounds and / or the additives, preferably below 300 ° C., are modified. The term low-melting additives is understood to mean additives which can be converted into the liquid state at the above-mentioned decomposition temperatures at normal pressure. Instead of intensive mixing, if desired, the cationic layer compounds obtained after production can then be ground with one or more additives selected from groups A) to F) in the presence of polar organic solvents or water, preferably with grinding media mills and in particular with a ball mill, dried and optionally dried. The term polar organic solvents is understood to mean hydrocarbon compounds which are liquid at room temperature (15 to 25 ° C.) and carry at least one more electronegative substituent than carbon. These include chlorinated hydrocarbons, alcohols, ketones, esters, ethers and / or glycol ethers. Suitable polar organic solvents are methanol, ethanol, n-butanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanol, isophorone, ethyl acetate, lactic acid ethyl ester, 2-methoxyethyl acetate, tetrahydrofuran, Ethyl glycol monomethyl ether, diethylene glycol monoethyl ether. For this subsequent modification, ie after drying of the cationic layer compounds produced according to the invention to form a powder, the modification with the organic additives takes place additive amounts of between approximately 5 and approximately 100% by weight, based on the cationic layer compound.

Another object of the present invention is the use of cationic layered compounds of the type described as co-stabilizers for halogen-containing plastics stabilized with calcium and / or zinc salts of carboxylic acids having 6 to 22 carbon atoms. The cationic layered compounds according to the invention are preferably used as co-stabilizers in halogen-containing plastics and in particular in PVC. For this purpose, the cationic layer compounds - without taking into account the proportion of the organic additives which may be present - in amounts of 0.01 to 5, preferably 0.1 to 3 parts by weight, based on 100 parts by weight of synthetic resins, are added. As a rule, they are mechanically mixed with the plastics in granular form before the deformation is carried out, for example in the calender and extrusion process. The commercially available zinc and / or calcium salts of carboxylic acids having 6 to 22 carbon atoms are usually mixed in as the usual stabilizers at the same time as the cationic layer compounds. Of course, other conventional additives, such as the heat stabilizers described in European application EP-A-189 899, can also be used. The amounts of the stabilizers and co-stabilizers among one another can vary as required, with the proviso that the total stabilizer addition is within the amount of 0.5 to 5 parts by weight, based on 100 parts by weight of synthetic resins. The minimum amount of cationic layer connection is accordingly at least 0.01% by weight. The use of the cationic layer compounds according to the invention improves the effect of zinc and / or calcium soaps in stabilizing the halogen-containing plastics. In addition, the cationic layered compounds according to the invention can be incorporated in the halogen-containing plastics as co-stabilizers, without adversely affecting the rheology of the plastics.

Examples

A) Preparation of the cationic visual connections

example 1

70 g of aluminum hydroxide from the Bayer process (58.3% Al2O3) are added to a suspension consisting of 81 g of magnesium oxide and 188 g of magnesium hydroxide carbonate of the approximate composition 4MgC03 * Mg (0H) 2 * 4H2Ü in 1.6 l of water and mixed with 6 , 4 g of 50% sodium hydroxide solution (10 mol% based on aluminum hydroxide). After a short time, the reaction mixture thickens. The reaction mixture is filled into an autoclave and heated to 140 ° C. An internal pressure of 5 bar builds up. After a reaction time of two hours, the pressure is released and the mixture is cooled. The resulting product is dried to constant mass in a drying cabinet. A prepared X-ray diffraction diagram as well as analytical tests confirm the identity of the resulting hydrotalcite of the approximate composition [Mg6Al2 (0H) ₁ 6] C03 * 4H20. The BET surface area was 90 m ² / g.

Example 2

To a suspension consisting of 39 g magnesium hydroxide and 61 g magnesium hydroxide carbonate in 500 ml water, 35 g aluminum hydroxide (58.3% Al2O3) are added and with 1.6 g 50% sodium hydroxide solution (5 mol% based on aluminum hydroxide ) offset. After a short time, the reaction mixture thickens. The reaction mixture is filled into an autoclave and heated to 200 ° C. An internal pressure of 20 bar builds up. To a reaction time of half an hour is relaxed and cooled. The resulting product is isolated by spray drying. A prepared X-ray diffraction diagram and analytical investigations confirm the identity of the resulting hydrotalcite with the approximate composition [Mg ₆ Al2 (OH) ₁₆ ] CO 3 * 4 H2O. BET surface area: 28 m ² / g.

Example 3

To a suspension consisting of 8 g magnesium oxide and 57 g magnesium hydroxide carbonate in 350 ml water, 21 g aluminum hydroxide (58.3% Al2O3) are added and with 1.0 g 50% sodium hydroxide solution (5 mol% based on aluminum hydroxide ) offset. After a short time, the reaction mixture thickens. The reaction mixture is filled into an autoclave and heated to 180 ° C. An internal pressure of 12 bar builds up. After a reaction time of half an hour, the pressure is released and the mixture is cooled. The resulting product is isolated by spray drying. A prepared X-ray diffraction diagram confirms the identity of the resulting hydrotalcite of the approximate composition [Mg Al2 (OH) ₁₀ ] (CO 3) 2 * 4H20. BET surface area: 75 m / g.

Example 4

50 g of sodium perchlorate are added to a suspension consisting of 24 g of magnesium oxide and 35 g of aluminum hydroxide in 550 ml of water, and 1.6 g of 50% sodium hydroxide solution are added. Shortly after homogenization, the reaction mixture thickened. The reaction mixture is filled into an autoclave and heated to 180 ° C. An internal pressure of 12 builds up cash on. After a reaction time of one hour, the pressure is released and the mixture is cooled. The resulting product is spray dried. A prepared X-ray diffraction chart confirms the identity of the resulting hydrotalcite in the approximate composition [Mg4Al ₂ (0H) ₁₂ ] (C104) 2 * 4H20. BET surface area: 35 m ² / g.

Example 5

21 g of sodium carbonate are added to a suspension consisting of 48 g of magnesium oxide and 35 g of aluminum hydroxide in 550 ml of water, and 1.6 g of 50% sodium hydroxide solution are added. Shortly after homogenization, the reaction mixture thickened. The reaction mixture is filled into an autoclave and heated to 180 ° C. An internal pressure of 12 bar builds up. After a reaction time of one hour, the pressure is released and the mixture is cooled. The resulting product is spray dried. A prepared X-ray diffraction diagram and analytical examinations confirm the identity of the hydrotalcite formed in the approximate composition [Mg5Al2 (0H) i] C03 * 4H20. BET surface area: 55 m / g.

Example 6

The suspension according to Example 1 is mixed with 12 g glycerol in a storage container and metered into a prepared tubular reactor heated to 140 ° C. by means of a pump with a pre-pressure> 6 bar. The flow rate was chosen so that the average residence time was 40 minutes. The product was spray dried directly. A prepared X-ray diffraction diagram and analytical tests confirm the identity of the resulting hydrotalcite with the approximate composition [Mg6Al2 (0H) χ6] C03 * 4H20. BET surface area: 85 m ² / g.

Example 7

70 g of aluminum hydroxide from the Bayer process (58.3% Al2O3) are added to a suspension consisting of 81 g of magnesium oxide and 188 g of magnesium hydroxide carbonate of the approximate composition 4MgCθ3 * Mg (OH) 2 * 4H2θ in 1.6 l of water, and 12 , 8 g of 50% sodium hydroxide solution (20 mol% based on aluminum hydroxide). After a short time, the reaction mixture thickens. The reaction mixture is filled into an autoclave and heated to 140 ° C. An internal pressure of 5 bar builds up. After a reaction time of two hours, the pressure is released and the mixture is cooled. The resulting product is spray dried. A prepared X-ray diffraction diagram and analytical tests confirm the identity of the resulting hydrotalcite of the approximate composition [MgöAl2 (0H) i5] C03 * 4H20. BET surface area: 85 m ² / g.

Example 8

20 g of epoxidized soybean oil (saponification number 125, epoxy oxygen content 5.8% by weight) are added to the suspension in accordance with Example 1 in a storage container and applied to a prepared and 140 ° C. by means of a pump with a pre-pressure> 6 bar ¬ heated tube reactor metered. The flow rate was chosen so that the average residence time was 40 minutes. The product was spray dried directly. A prepared X-ray diffraction diagram as well as analytical tests confirm the Identity of the resulting hydrotalcite of the approximate composition [Mg6Al2 (0H) iö] C03 * 4H20. BET surface area: 78 m ² / g.

Example 9

The suspension corresponding to Example 1 is mixed with 15 g of pentaglycerol with an average degree of condensation of 5, an average molecular weight of 380 and a hydroxyl number of about 1012 in a storage container and heated to a prepared and 140 ° C. by means of a pump with a pre-pressure> 6 bar Tube reactor metered. The flow rate was chosen so that the average residence time was 40 minutes. The product was spray dried directly. A prepared X-ray diffraction diagram and analytical investigations confirm the identity of the resulting hydrotalcite with the approximate composition [Mg ₆ Al2 (0H) ₁₆ ] CO ₃ * 4H20. BET surface area: 90 m / g.

Example 10

The suspension according to Example 1 is added and kosfettsäuremonoester via a pump with an inlet pressure> 6 bar metered into a vorberei¬ ended and 140 ° C heated tubular reactor container in a Vorlagebe¬ with 25 g of diglycerol Ci2 / i8 ^-K °. The flow rate was chosen so that the average residence time was 40 minutes. The product was spray dried directly. A prepared X-ray diffraction diagram as well as analytical examinations confirm the identity of the resulting hydrotalcite with the approximate composition [MgöAl2 (OH) i6] Cθ3 * 4H2θ. BET surface area: 80 m ² / g. Example 11

The suspension corresponding to Example 1 is mixed with 5 g of sodium stearate in a storage container and metered into a prepared tube reactor heated to 140 ° C. by means of a pump with a pre-pressure> 6 bar. The flow rate was chosen so that the average residence time was 40 minutes. The product was spray dried directly. A prepared X-ray diffraction diagram as well as analytical investigations confirm the identity of the resulting hydrotalcite of the approximate composition [Mg ₆ Al2 (0H) ₁₆ ] C03 * 4H20. BET surface area: 75 m ² / g.

Example 12

The suspension according to Example 1 is in a storage container with 20 g of a copolymer of 46 wt .-% styrene, 23 wt .-% α-methylstyrene and 31 wt .-% acrylic acid with a molecular weight (weight average) of 6000 added and metered in via a pump with a pre-pressure> 6 bar into a prepared tube reactor heated to 140 ° C. The flow rate was chosen so that the average residence time was 40 minutes. The product was spray dried directly. A prepared X-ray diffraction diagram and analytical investigations confirm the identity of the resulting hydrotalcite of the approximate composition [MgeAl2 (OH) i6] CO 3 * 4 H2O. BET surface area: 85 m ² / g.

Example 13

The suspension according to Example 1 is in a storage container with 15 g of a copoly er made from 95% by weight methyl acrylate and 5 % By weight of dimethylaminopropyl methacrylamide with a molecular weight (weight average) of 5,000 and metered in via a pump with a pre-pressure> 6 bar into a prepared tube reactor heated to 140 ° C. The flow rate was chosen so that the average residence time was 40 minutes. The product was spray dried directly. A prepared X-ray diffraction diagram as well as analytical investigations confirm the identity of the resulting hydrotalcite with the approximate composition [MgöAl (OH) ₁ 6] Cθ3 * 4H2θ. BET surface area: 85 m / g.

Comparative Example 1

35 g of aluminum hydroxide (58.3% Al 2 O 3) are added to a suspension consisting of 27 g of magnesium oxide and 61 g of magnesium hydroxide carbonate in 500 ml of water. In this case, sodium hydroxide solution was not added. There is no thick step. The reaction mixture is filled into an autoclave and heated to 180 ° C. An internal pressure of 12 bar builds up. After a reaction time of two hours, the pressure is released and the mixture is cooled. The reaction mixture is spray dried. An X-ray diffraction diagram shows the minimal formation of hydrotalcite in addition to unreacted starting products such as hydrargillite, magnesium hydroxide carbonate and magnesium hydroxide.

Comparative Example 2 (Alkali Source: Na Stearate)

35 g of aluminum hydroxide (58.3% Al 2 O 3) are added to a suspension consisting of 27 g of magnesium oxide and 61 g of magnesium hydroxide carbonate in 500 ml of water. As an alkali source and as a surface modifier, 12.3 g of sodium stearate (10th mol% based on AI) added. There is no thick step. The reaction mixture is filled into an autoclave and heated to 180 ° C. An internal pressure of 12 bar builds up. After a reaction time of two hours, the pressure is released and the mixture is cooled. The reaction mixture is spray dried. A prepared X-ray diffraction diagram shows the minimal formation of hydrotalcite in addition to unreacted starting products such as hydrargillite, magnesium hydroxide carbonate and magnesium hydroxide.

Example 14

4.2 g of sodium carbonate are added to a suspension consisting of 11.9 g of Zn (NÜ3) 2 ^• 6 H2O, 3.2 g of MgO and 3.1 g of aluminum hydroxide in 550 ml of water and 0.3 g of 50% -sodium hydroxide solution added. A short time after homogenization, the reaction mixture thickened. The reaction mixture is filled into an autoclave and heated to 180 ° C. An internal pressure of 12 bar builds up. After a reaction time of one hour, the pressure is released and the mixture is cooled. The resulting product is spray-dried. A prepared X-ray diffraction diagram and analytical tests confirm the identity of the resulting hydrotalcite in the approximate composition [g ₄ Zn2Al2 (0H) ₁₆ ] C03 * 4H20. BET surface area: 55 m ² / g.

In the examples, a laboratory spray dryer from Büchi was used for the spray drying. Drying was carried out in cocurrent with electrically heated air. The air inlet temperatures were in the range from 160 to 200 ° C, the air outlet temperatures in the range from 75 to 100 ° C. B) Application engineering examples

The "static stability" of rolled skins, which were mixed with stabilizer mixtures (parts by weight are parts by weight), was examined:

0.5 part by weight of zinc stearate 0.5 part by weight of calcium stearate

0.2 part by weight of stearoylbenzoylmethane (Rhodiastab ^R 50) 1.0 part by weight of the substances according to the invention based on 100 parts by weight of suspension polyvinyl chloride with a K value of 65.

For this purpose, polyvinyl chloride molding compositions containing stabilizer were processed on a laboratory roller mill measuring 450 × 220 mm (from Berstorff) at a roller temperature of 170 ° C. and a roller speed of 12.5 rpm in synchronism to test skins. The approx. 0.5 m thick skins were cut into square specimens with an edge length of 10 mm, which were then exposed to a temperature of 180 ° C in a drying cabinet with six rotating trays (Heraeus FT 420 R). The samples were removed at intervals of 15 minutes and their change in color was assessed.

The results are summarized in the table.

Table: Results of the stability test

Test substance first discolouration End of stability after minutes: (blackening) after minutes:

without cationishe 15 45

Shift connection

Example 1 15 90

Example 2 30 120

Example ¹ 3 30 105

Example ^' 4 15 90

Step Example ^'5 30 105

Step Example ^'6 30 90

Step Example ^'7 15 60

Step Example ^'1 8 30 105

Example 1 9 30 120

Example 1 10 30 135

Example 1 11 30 105

Example 1 11 *) 30 120

Example 1 12 30 120

Example 1 12 *) 30 135

Example 1 13 30 120

Example 1 14 30 120

^r ) After spray drying in a forced-air drying cabinet at 200 ° C to dry to constant weight.

Claims

claims

1. Means for stabilizing halogen-containing plastics against thermal or photochemical degradation, containing cationic layer compounds of the general formula (I)

[M () _χ Al (0H) _y ] (A ⁿ -) _z . mH 0 (I)

in the MOO stand for at least one divalent metal ion and A ⁿ ~ for an acid anion of the charge n- (n = 1, 2 or 3), and the conditions l <x <5, y> z, (y + nz) = 2x + 3 and 0 <m <10 apply,

characterized in that it is obtainable by adding 1 to 20 mol%, based on aluminum hydroxide, of alkali metal hydroxide, to an aqueous mixture of at least one source of divalent metal ions MUH, a source of the anions A ⁿ ~ and crystalline aluminum hydroxide Heated between 10 and 240 minutes to a temperature between 100 and 240 ° C and dried to a powder without first separating the solid from the water phase.

2. Composition according to claim 1, characterized in that a total of 2 to 10 mol% alkali metal hydroxide, based on aluminum hydroxide, is added to the aqueous mixture.

3. Composition according to one or both of claims 1 and 2, characterized in that sodium hydroxide is used as the alkali metal hydroxide.

4. Composition according to one or more of claims 1 to 3, characterized in that it is in the form of a powder with a specific BET surface area, measured with nitrogen, is from 50 to 200 m / g.

5. Composition according to one or more of claims 1 to 4, characterized in that they additionally contain a total of 0.5 to 15% by weight, based on the cationic layer compound, of one or more additives selected from the following groups:

A) polyols with 3 to 30 carbon atoms and at least 2 hydroxyl groups,

B) esters of partially or completely epoxidized unsaturated carboxylic acids having 6 to 22 carbon atoms,

D) alkyl and aryl phosphites,

E) anions of saturated or unsaturated fatty acids with 6 to 22 carbon atoms,

6. Composition according to one or more of claims 1 to 5, characterized in that in the general formula (I) M ^ ¹¹ ) represents magnesium, calcium or zinc.

7. Process for the preparation of cationic layer compounds of the general formula (I) [M (II) _x Al (0H) _y ] (An) _z . mH ₂ 0 (I)

in the MUO stand for at least one divalent metal ion and A ⁿ "for an acid anion of the charge n- (n = 1, 2 or 3), and the conditions 1 <x <5, y> z, (y + nz) = 2x + 3 and 0 <m <10 apply,

characterized in that an aqueous mixture of at least one source of divalent metal ions M (H), a source of the anions A ⁿ ~ and crystalline aluminum hydroxide with 1 to 20 mol%, based on aluminum hydroxide, alkali metal hydroxide, for a time between 10 to 240 minutes to a temperature between 100 and 240 ° C and dried to a powder without prior separation of the solid from the water phase.

8. The method according to claim 7, characterized in that a total of 2 to 10 mol of alkali metal hydroxide, based on aluminum hydroxide, is added to the aqueous mixture.

9. The method according to one or both of claims 7 and 8, characterized in that sodium hydroxide is used as the alkali metal hydroxide.

10. The method according to one or more of claims 7 to 9, characterized in that in the general formula (I) MU ¹ ) represents magnesium, calcium or zinc.

11. The method according to one or more of claims 7 to 10, characterized in that the aqueous mixture before or after heating to 100 to 240 ° C, but before drying, a total of 0.5 to 15 wt .-%, based on the calculated amount in itself forming cationic layer compound, one or more additives selected from the following groups:

A) polyols with 3 to 30 carbon atoms and at least 2 hydroxyl groups,

D) alkyl and aryl phosphites,

E) saturated or unsaturated fatty acids with 6 to 22 carbon atoms or their salts,

12. The method according to one or more of claims 7 to 11, characterized in that one or more alkali metal salts of carbonic acid and / or oxo acids of halogens in amounts between 1 and. The aqueous mixture before heating to 100 to 240 ° C. 100 mol% based on the aluminum content added.

13. The method according to one or more of claims 7 to 12, characterized in that it is carried out continuously.

14. The method according to one or more of claims 7 to 13, characterized in that the drying is carried out as spray drying.

15. Use of the agent according to one or more of claims 1 to 6 or of the product produced by the process according to one or more of claims 7 to 14 as a stabilizing additive to halogen-containing plastics against thermal or photochemical degradation.