EP0771310A1

EP0771310A1 - Lattice layer compounds and their use

Info

Publication number: EP0771310A1
Application number: EP95925862A
Authority: EP
Inventors: Michael Schiller; Paul Ebner; Klaus Dolleschal; Karoline Pacher; Christina Summerer
Original assignee: Metallgesellschaft AG
Current assignee: GEA Group AG
Priority date: 1994-07-16
Filing date: 1995-07-12
Publication date: 1997-05-07
Also published as: BR9508285A; CA2195244A1; AU2983195A; WO1996002465A1; DE4425266C1; JPH10504050A

Abstract

Lattice layer compounds have the general formula (I): LiaMeIIb+cMeIIIb-c(OH)dAn-e*mH2O, in which MeII stands for Mg, Ca, Zn and/or Sn?2+; MeIII¿ stands for Al and/or Fe3+; An- stands for an anion of n valence or for a mixture of anions, and the indices lie in the following ranges: 0 < a ≤ 1, 2 ≤ b ≤ 6, -0,5 ≤ c ≤ 0,5 and m = 0 to 5, d and e are different from 0 and are selected so that a neutral molecule is obtained. Also disclosed is the use of these lattice layer compounds as stabilisers or stabilising components for halogenated polymers.

Description

Layered grid connections and their use

ßeschrejbμng:

The invention relates to layered lattice compounds of the general formula

Li.Me ^,, _{b + c} Me ^,, V. (OH) _d A ⁿ . * ΠιH ₂ O (I) in

Me "Mg, Ca, Zn and / or Sn ²⁺ Me ¹ " Al and / or Fe ³⁺

A ^{n is} an anion of valence n or a mixture of anions, the indices in the range from 0 <a _≤_ l, 2 _≤. b _≤_ 6, -0.5 <_ c <_ 0.5 and m = 0 to 5, d, e are not equal to 0 and are chosen so that a neutral molecule is obtained.

The invention further relates to the use of the layered lattice compounds according to the invention as stabilizers or stabilizer components for halogen-containing polymers.

A halogen-containing thermoplastic resin, e.g. Polyvinyl chloride (PVC) changes into a polyene structure when melt deformation is carried out, hydrochloric acid being eliminated and the polymer discolored. In order to improve the thermal stability of the polymer, it is common to incorporate metal carboxylates as stabilizers into the resin. However, since the incorporation of the stabilizers in a longer melt-molding process alone can lead to so-called metal burning, which causes the polymer to become black, it is common practice to

ERSÄΓZBLÄIT (RULE 26) a costabilizer, such as polyols (such as pentaerythritol), organic phosphonic acid esters (such as phenylphosphite), epoxy compounds (such as epoxidized soybean oil)

As basic lead salts, like other heavy metal stabilizers, are classified as toxic, attempts are being made to find stabilization alternatives. A large number of combinations of inorganic and organic substances are known as stabilizers for halogen-containing polymers. In documents DE 30 19 632 and EP 0 189 899, hydrotaicites are proposed as stabilizers. These substances are mixtures of Ca / Zn metal carboxylates with regard to their effect on the heat stability and the transparency of the resins stabilized with them. However, this can be achieved by using hydrotalcites Problem of discoloration of the polymer cannot be solved during processing. According to document EP 0 063 180, it is proposed to use combinations of hydrotalcites and 1,3-diketo compounds to solve this problem

In document EP 0 139 931 basic compounds, which are combinations of mono- and divalent cations or of divalent and trivalent cations with various anions, are disclosed as stabilizers. These substances, in particular those shown in the examples, are aluminum-rich hydrotaicites or compounds with high hydrotalcite content In mixtures with Zn metal carboxylates, their addition to halogen-containing resins leads to an improvement in heat stability. However, the use of such substances also does not solve the problem of discoloration of the polymer during processing. As suggested above, combinations with 1,3-diketo compounds must be used to solve this problem

In the documents DE 39 41 902 and DE 41 06 411 or DE 40 02 988 and DE 41 06 404 and DE 41 03 881 basic calcium aluminum hydroxy phosphites or basic Calcium aluminum hydroxy carboxylates and hydrocalumites are proposed as stabilizers for halogen-containing polymers, in particular PVC. These substances are stabilizer mixtures with hydrotalcites inferior in their effect on the heat stability and the transparency of the resins stabilized therewith. Furthermore, by using such substances with water of hydration Problems arise when processing the halogen-containing resin due to the elimination of the water of crystallization (cf. M Meyn "Double hydroxides and hydroxide double salts - synthesis. Properties and anion exchange behavior", dissertation. Kiel 1991). Document EP-A-0 256 872 suggests that this disadvantage may arise Remove additions of former magnesium oxide

The documents DE 41 03 916 and DE 41 06 403 disclose basic hydroxy compounds from divalent and trivalent metal ions, which are defined as "not of the hdrdrotalcite type", inter alia as PVC stabilizers. These substances are also stabilizer mixtures with hydrotalcites with regard to their heat-stabilizing properties Inferior to the effect and transparency of the staoiiized products Furthermore, when using such substances with hydrated water, problems can also arise in the processing of the halogen-containing resin by the elimination of the crystal water

The invention is based on the object of providing new layered grid compounds which are particularly suitable as stabilizers for halogen-containing polymers without having the disadvantages of the known stabilizers mentioned above and which are in particular classified as non-toxic

This object is achieved according to the invention by providing layered grid compounds of the general formula

Li ₁ Me ^I. , _.C Me ' ^: _b , (OH) _J A ⁿ ₅ * mRO

woπn

Me ¹¹ Mg, Approx. Zn and / or Sn ^: ~ Me AI and / or Fe ³⁺

A "^{" is} an anion of valence n or a mixture of anions, the

Indices in the range of

0 <a <1,

2 <b <6,

-0.5 <c <0.5 and m = 0 to 5

cherish, d. e are not equal to 0 and are chosen so that a neutral molecule is obtained.

It is known that soluble lithium compounds, which are used as stabilizers in halogen-containing polymer compositions, increase the water absorption capacity of these resins. In the case of cable insulation, the insulating effect deteriorates and in pressurized water pipes, the load capacity due to the internal water pressure is reduced. Lithium carbonate has no stabilizing effect, whereas lithium hydroxide has a good stabilizing effect. however, the initial color and the gradient are adversely affected. Lithium oxide shows similar stabilizer properties on halogen-containing polymer compositions such as lithium hydroxide, but here too the hydrophilicity is disadvantageous. Stabilizer mixtures. which contain lithium oxide are not stable in storage. Lithium salts with fatty acids, in particular stearic acid, are known as PVC stabilizers. Document DE-A-1 1 15 460 describes a combination of lithium stearate and glycine mono- (acetylricinoleate) for use as a PVC stabilizer. However, these stabilizers have no commercial importance. On the one hand, because a melting reaction of lithium stearate is difficult (melting point of lithium stearate: 200 to 15 ° C), on the other hand, because soluble salts, such as hydroxide or chloride, are required for the production via a precipitation reaction, both of which are comparatively necessary are expensive. In contrast to known stabilizers, such as hydrated lime, magnesium and lithium hydroxide, they take Compounds according to the invention no carbon dioxide from the air. In contrast to lithium hydroxide, the layered grid compounds according to the invention are sparingly soluble. In contrast to hydrotalcites, they have a significantly reduced hydrophilicity, which is reflected in less moisture absorption from the air.

Surprisingly, it has been shown that the substances according to the invention contain halogen. thermoplastic resins and the parts made therefrom give a higher heat stability compared to halogen-containing thermoplastic resins and the parts made therefrom which do not contain the substances according to the invention. The substances according to the invention prevent discoloration in the production of e.g. hard PVC extrudates. Both the color gradient and the weathering stability of the test bodies stabilized with the substances according to the invention are better than those of such test bodies. which do not contain the substances according to the invention. In contrast to structurally comparable three-base lead sulfate, the transparency of transparent halogen-containing resins is not impaired by the use of the compounds according to the invention.

The layer lattice compounds are obtained in that lithium hydroxides, oxides and / or compounds which can be converted into hydroxide are mixed in the water medium. Metal (II) hydroxides, oxides and / or their compounds which can be converted into hydroxides of the metals mentioned and aluminum and / or iron (III) hydroxides and or their compounds which can be converted into hydroxides as well as acids and / or their salts or Mixtures of these are reacted with one another at a pH of 8 to 10 and at temperatures of 20 to 250 ° C. and the solid reaction product obtained is separated off.

The reaction product obtained directly from the above-described reaction can be separated from the aqueous reaction medium by known processes, preferably by filtration. The separated reaction product is also worked up in a manner known per se, for example by washing the filter cake with water and drying the washed residue at temperatures of, for example, 60 to 150 ° C., preferably at 90 to 120 ° C.

In the case of aluminum, both finely divided, active metal (III) hydroxide in combination with sodium hydroxide and NaAlO can be used for the reaction. Lithium or the metal (II) can be used in the form of finely divided lithium oxide or hydroxide or mixtures thereof or of finely divided metal (II) oxide or hydroxide or mixtures of the metals mentioned. The corresponding acid amones can be used in different concentrations, e.g. directly as an acid or as a salt.

The reaction temperatures are preferably between about 20 to 250 ° C. further in particular between about 60 and 180 ° C. No catalysts or accelerators are required. In the substances according to the invention, the water of crystallization can be removed in whole or in part by thermal treatment.

When used as stabilizers, the dried layered grid compounds according to the invention do not split off any water or another gas at the processing temperatures of 160 to 200 ° C. customary for rigid PVC. so that no disturbing blistering occurs in the molded parts.

The anion in the general formula IA ^{n '} can be sulfate. Sulfite, sulfide, thiosulfate, peroxide. Peroxosulfate, hydrogen phosphate. Hydrogen phosphite, carbonate. Halides, nitrate, nitrite, hydrogen sulfate. Hydrogen carbonate, hydrogen sulfite. Hydrogen sulfide. Dihydrogen phosphate, dihydrogen phosphite, monocarboxylic acid anions such as acetate and bezoat. Amide, azide, hydroxide. Hydroxylamide. Hydrazide. Acetylacetonate. Phenolate. Pseudohalides. Halogenites, halogenates, perhalogenates, I, ^' , permanganate, dianions of dicarboxylic acids such as phthalate. Oxalate. Maleate or fumarate, bisphenolates. Phosphate, pyrophosphate, phosphite, pyrophosphite, trianions of tricarboxylic acids such as citrate, trisphenolates and much more as well as mixtures of the anions mentioned. Among them, hydroxide, carbonate, phosphite and maleate are preferred.

To improve the dispersibility of the substances according to the invention in halogen-containing thermoplastic resins they can be mixed with a higher fatty acid, e.g. Stearic acid, an anionic surfactant, a silane coupler, a titanate coupler, a glycerin fatty acid ester.

The substances of the formula I according to the invention can advantageously be used as stabilizers for halogen-containing thermoplastic resins. Examples of such resins are PVC, polyvinylidene chloride, chlorinated or chlorosulfonic polyethylene. chlorinated polypropylene or chlorinated ethylene-vinyl acetate copolymer The layered lattice compounds according to the invention are particularly suitable as stabilizers for resins of the PVC type, i.e. Vinyl chloride homopolymers and copolymers of vinyl chloride with other monomers.

It is also advantageously possible to use additionally known co-stabilizers. e.g. Metal carboxylates (group a).

1.3-Diketo compounds, organic esters of phosphorous acid, polyols and amino acid derivatives (group b) lead to a significant improvement in the initial color. In addition, the addition of at least one substance (group c) selected from the group of the antioxidants and the epoxy compounds can lead to a significant improvement in the color gradient. The addition of at least one substance (group b) plus at least one substance (group c) is very advantageous.

Examples of the metal carboxylates (group a> are the salts of higher fatty acids, naphthenic acid of metals of the second group of the periodic table of the elements. Examples of suitable metals of the second group are magnesium, Calcium, strontium barium, zinc Such salts of higher fatty acids such as stearic, palmitic, myristic, lauπn, ricinoleic acid are particularly advantageous. Zinc salts are particularly effective for the color gradient. For this reason, at least part of a zinc salt of a higher fatty acid is preferably used. Although the above metal carboxylates can be used individually, the stabilizing effect can be increased when two or more metal carboxylates are used

Examples of the 1,3-diketone compounds are dibenzoyimethane, stearoylbenzoylmethane, palmitoylbenzoylmethane, myπstoylbenzoyimethane. Lauroylbenzoylmethane, benzoylacetone. Acetylacetone, tribenzoylmethane, diacetvlacetobenzene. p-methoxystearoylacetophenone. Acetoacetic acid ester and acetylacetone

Examples of the esters of phosphorous acid are triaryl phosphites such as triphenyl phosphite, tris (p-nonylphenyl) phosphite (TNPP); Alkylaryl phosphites such as monoalkyl diphenyl phosphites. e.g. diphenyl isooctyl phosphite, diphenyl isodecyl phosphite and dialkyl monophenyl phosphites such as phenyl diisooctyl phosphite. Phenyldiisodecyl phosphite and trialkyiphosphites, such as triisooctyl phosphite. Tristearyl phosphite.

Examples of the polyol are trismethylolpropane, di (trismethylolpropane), erythritol, pentaerythritol. Dipentaerythritol, sorbitol. Mannitol.

Examples of the amino acid derivatives are glycine, alanine, lysine, tryptophan, acetylmethionine, pyrrolidonecarboxylic acid, ß-aminocrotonic acid, α-aminoacrylic acid. α-aminoadipic acid and the corresponding esters. The alcohol components of these esters include monohydric alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, i-propyl alcohol. Butyl alcohol. α-ethylhexanol. Octyl alcohol. i-octyl alcohol, lauryl alcohol. Stearyl alcohol and polyol such as ethylene glycol. Propylene glycol, 1,3-butanediol, 1, 4-butanediol, Glycerol, diglycerol, trismethylolpropane, pentaerythritol, dipentaerythritol, erythrithol, sorbitol, mannitol.

Examples of the antioxidants are 2,5-di-tert-butyl-hydroquinone, 2,6-di-tert-butyl-4-methyl-phenol, 4,4'-thiobis (3-methyl-6-tert-butyl -phenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), stearyl-3- (3 ^, -5'-di-tert-butyl-4'-hydroxyphenyl) propionate.

The epoxy compounds include various animal or vegetable oils. like epoxy soybean oil. Epoxy rapeseed. epoxidieπe fatty acid esters, such as epoxidized epoxymethyl oleate. Epoxybutyl oleate, epoxidized alicyclic substances, glycidyl ethers such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether; Glycide ester. such as glycidyl acrylate. Glycidyl methacrylate. their polymers. Copolymers; and epoxidized polymers such as epoxidized polybutadiene, epoxidized acrylic acid-butadiene-styrene terpolymer (ABS).

Preferred dosage amounts (in parts by weight per 100 parts by weight of resin) for the substances of the formula I according to the invention are 0.1 to 5. preferably 0.5 to 3.

Preferred dosage amounts for the co-stabilizers are.

Group a) metal carboxylates: 0 1 to 5. preferably 0.5 to 3; Group b) 1,3-diketo compounds, organic phosphites, polyols,

Amino acid derivatives: 0 to 5, preferably 0.1 to 3; Group c) antioxidants, epoxy compounds: 0 to 5. preferably 0.05 to 4

In particular, combinations of substances of the formula I according to the invention and metal carboxylates are preferred as stabilizer mixtures for halogen-containing resins.

The halogen-containing thermoplastic resin composition stabilized according to the invention can further contain the additives known to the person skilled in the art, such as fillers, lubricants, plasticizers, dyes, pigments, antistatic agents, surface-active agents, foaming agents, impact modifiers, UV stabilizers.

The addition of a plasticizer is particularly common. For example, phthalic acid esters such as dioctyl phthalate (DOP), aliphatic dibasic acid, trimellitic acid, phosphate, fatty acid esters, epoxy plasticizers, polyester plasticizers, chlorinated paraffin and similar plasticizers can be added in suitable proportions, based on the halogen-containing thermoplastic resin.

The molding processes with which the halogen-containing thermoplastic resin composition stabilized according to the invention can be processed are calendering, extrusion, injection molding, blow molding or other processes.

The thermostability and the initial color and the color gradient of the halogen-containing thermoplastic resin is increased by adding the substances according to the invention according to formula I, in particular together with metal carboxylates (group a) and preferably also together with the costabilizers (group b) or / and (group c) the specified amounts significantly improved.

The resin compositions stabilized according to the invention have no plate-out phenomenon during calendering and allow extrusion in long-term operation. In addition, the resulting products are free from discoloration.

The present invention is therefore a remarkable new contribution to the processing of PVC and other halogen-containing thermoplastic resins. The invention is illustrated in more detail by the following examples, without, however, being restricted thereto.

EXAMPLES

1. Production of the substances according to the invention

Example 1 ⁽ Link 1)

2 mol (80 0 g) magnesium oxide in 600 mL water for 30 min. touched. 2 mol (164 0 g) of anhydrous sodium aluminate are dissolved in 700 ml of water. 0 13 mol (5.5 g) of lithium hydroxide monohydrate is dissolved in 150 ml of water and the lithium hydroxide solution and the MgO suspension are added to the sodium aluminate solution in rapid order. A temperature rise to 35 ° C is observed. After stirring for one hour, CO is introduced at room temperature to pH 9.0. After carbonation, the excess CO is boiled to pH 10.0. The batch is made up to a volume of three liters and treated at 80 to 95 ° C. for three hours. The reaction product is filtered off and washed three times with two liters of water. The filter cake is dried in vacuo at 130 ° C for four hours.

Received product: Li _o , ₆ Mg ₄₀ Al _{? 8} (OH) _l77 CO,

Analysis: Li 0 30%. Mg 16 50%. AI 17.50%, CO, 7 50% Example 2 (Link 2)

1.5 mol (60.0 g) magnesium oxide are dissolved in 600 mL water for 30 min. stopped. 1.5 mol (123.0 g) of anhydrous sodium aluminate are dissolved in 700 ml of water. 0.275 mol (1 1.5 g) of lithium hydroxide monohydrate is dissolved in 150 ml of water and the lithium hydroxide solution and the MgO suspension are added to the sodium aluminate solution in rapid order. A temperature rise to 35 ° C is observed. After stirring for one hour, CO. initiated to pH 9.0. After carbonation, the excess CO is boiled to pH 10.0. The batch is made up to a volume of three liters and treated for three hours at 80 to 95 ° C. The reaction product is filtered off and washed three times with two liters of water. The filter cake is dried in vacuo at 130 ° C for four hours.

Product received: Li _{O 5?} Mg, _.0 Al, ₉₅ (OH) ₁₃₆ CO,

Analysis: Li 0.89%, Mg 17.30%, AI 18.40%. CO, 10.20%

Example 3 (Link 3)

1.5 mol (60.0 g) magnesium oxide are dissolved in 600 mL water for 30 min. touched. 1.2 mol (123.0 g) of anhydrous sodium aluminate are dissolved in 700 ml of water. 0 4 mol (16 8 g) of lithium hydroxide monohydrate is dissolved in 150 ml of water, and the lithium hydroxide solution and the MgO suspension are added to the sodium aluminate solution in rapid order. A temperature rise to 35 ° C is observed. After stirring for one hour, CO is introduced at room temperature to pH 9.0. After carbonation, the excess CO is boiled to pH 10.0. The batch is made up to a volume of three liters and treated at 80 to 95 ° C. for three hours. The reaction product is filtered off and washed three times with two liters of water. The filter cake is dried in vacuo at 130 ° C for four hours. Product obtained: Li _{o go} Mg _{3 IO} Al ,, ₀ (OH) ₁₃₄ CO ₃

Analysis: Li 1.10%, Mg 15.90%, AI 16.20%, CO, 9 50%

Example 4 (Link 4)

2.5 mol (100.0 g) magnesium oxide are dissolved in 600 mL water for 30 min. touched. 2.5 mol (205 g) of anhydrous sodium aluminate are dissolved in 700 ml of water. 0 085 moi (3.6 g) of lithium hydroxide monohydrate is dissolved in 150 ml of water and the lithium hydroxide solution and the MgO suspension are added to the sodium aluminate solution in rapid order. A temperature rise to 35 ° C is observed. After stirring for one hour, CO is introduced at room temperature to pH 9.0. After carbonation, the excess CO. boiled to pH 10.0. The batch is filled up to a volume of three liters and pressure treated for six hours at 10 bar and about 180 ° C. The reaction product is filtered off and washed three times with two liters of water. The filter cake is dried in vacuo at 130 ° C for four hours.

Product obtained: Li _{0! 7} Mg _{5 I0} Al ₄ , ₀ (OH) ,, ₈ CO _j

Analysis: Li 0.17%, Mg 18.20%. AI 19.00%. CO, 6.50%

A person skilled in the art can find a general procedure in Examples 1 to 4. The essence of the general working procedure is that

1 shows the stochiometric ratios of the components for obtaining the substances according to the invention and

2. when adding the anion (s) a pH value of 10 is not decisively exceeded. Examples 5 to 1 1

The following further compounds according to the invention were produced:

Tab. 1:

With iel formula conn

2. Comparative compounds not according to the invention

Examples 12 to 13

Example connection

12 Hydrotaicit Mg ₄ Al, (OH) ,, CO, * 3H, O 12 (not hydrothermally treated) Hvdrocalumit Ca ₄ Al, (OH) ,, HPO, * 2H, O 13 3 Use of the substances according to the invention as stabilizers

In the following example, the heat stability according to the MATHIS thermal furnace test (MTT) and the initial color are evaluated by the yellowness index (YI 0min.) Of PVC moldings to which substances according to the invention and substances not according to the invention have been added for comparison purposes.

For this purpose, PVC resin masses were homogenized and plasticized on a laboratory rolling mill at 180 ° C for five minutes. A test strip of 10 mm width was cut out of the approximately 1 mm thick rolled sheet and tempered in the MATHIS thermo-oven at 180 ° C. At intervals of 10 min. the test strip was moved 23 mm out of the oven until it turned black.

Tab. 2: Test recipe

¹¹ Lubricant - ester wax Example 14

Tab. 3. Results of the application studies

Connection MTT / min. YI Omin.

without

4

5

6

7

8th

9

10

1 1

12th

13

Claims

PATENT CLAIMS

1 layered lattice compounds of the general formula

Li _i Me "^ Me ^UI _l>< (OH) _(J A ⁿ - _e * mH, O (I)

wherein

Me ' ^: Mg, Ca. Zn and / or Sn ^{: "}

A ^{n "is} an anion of valence n or a mixture of anions, the indices in the range of

0 <a <1,

- b <6,

-0.5 <c <0.5 and m = 0 to 5

lying, d. e are not equal to 0 and are chosen so that a neutral molecule is obtained.

2. Layered lattice compounds according to claim 1, characterized in that the anion (A ⁿ ) from the group containing sulfate, sulfite, sulfide. Thiosulfate, peroxide, peroxosulfate. Hydrogen phosphate, hydrogen phosphite, carbonate, halides, nitrate, nitrite, hydrogen sulfate, hydrogen carbonate. Hydrogen sulfite, hydrogensulfide. Dihydrogen phosphate, dihydrogen phosphite, monocarboxylic acid anions such as acetate and benzoate, A id, azide, hydroxide, hydroxylamide, Hvdrazid. Acetylacetonate. Phenolate. Pseudohalides. Halogenites. Halogenates, perhalogenates. I, ^' , permanganate, dianions of dicarboxylic acids such as phthalate, oxalate, maleate or fumarate, bisphenolates, phosphate. Pyrophosphate, phosphite, pyrophosphite. Trianions of tricarboxylic acids such as citrate, trisphenolates and a mixture of anions is selected.

3. Use of the layered grid compounds according to claim 1 or 2 as a stabilizer or stabilizer component for halogen-containing polymers.

4. Stabilizer according to claim 3, characterized in that it further contains at least one compound selected from the group of metal carboxylates.

5. Stabilizer according to claim 3 or 4, characterized in that it further comprises at least one compound selected from the group containing 1.3-diketo compounds. contains organic esters of phosphorous acid, epoxy compounds, polyols and amino acid derivatives.