DE4327297B4 - Use of piperidine compounds - Google Patents

Abstract

worin
R₁ Methyl,
R₂ Methoxyphenyl,
R₃ Sauerstoff, -NH- oder -N(C_1-4-Alkyl)- und
alle R₈ unabhängig voneinander Wasserstoff oder Methyl bedeuten,
zur Herstellung mit HALS-Verbindungen chemisch gebundener Kunststoffe.Use of piperidine compounds of the formula I

wherein
R _{1 is} methyl,
R _{2 is} methoxyphenyl,
R _{3 is} oxygen, -NH- or -N (C _1-4 -alkyl) - and
all R ₈ independently of one another denote hydrogen or methyl,
for manufacturing with HALS compounds of chemically bonded plastics.

Description

From the DE 42 00 192 A1 For example, mixtures of 2,2,6,6-tetramethylpiperidine derivatives and zinc dialkyl (di) thiophosphates are known which impart antioxidant properties to lubricants and exert an influence on viscosity.

The DE 26 54 058 A1 discloses hydroxybenzylmalonic acid derivatives of 1-acylpiperidin-4-ols and 1-acyl-4-aminopiperidines and their use to stabilize plastics against thermal oxidative and light induced aging.

The JP 02009680 A discloses 4-substituted 2,2,6,6-tetraalkylpiperidine derivatives as part of a color development system.

worin R₁ Methyl,
R₂ Methoxyphenyl,
R₃ Sauerstoff, -NH- oder -N(C_1-4-Alkyl)- und
alle R₈ unabhängig voneinander Wasserstoff oder Methyl
bedeuten,
sehr leicht chemisch an Kunststoffe binden kann und damit lichtstabilisierte Kunststoffe erhält, deren Stabilisator praktisch untrennbar mit diesem Kunststoff verbunden ist.It has been found that piperidine compounds of the formula I

wherein R _{1 is} methyl,
R _{2 is} methoxyphenyl,
R _{3 is} oxygen, -NH- or -N (C _1-4 -alkyl) - and
all R _{8 are} independently hydrogen or methyl
mean,
very easily chemically bind to plastics and thus obtains light-stabilized plastics whose stabilizer is virtually inseparable from this plastic.

object The invention is therefore the use of piperidine compounds the above formula I for the preparation with HALS compounds (which are the piperidine compounds or residues acting as stabilizer) chemically bonded plastics.

Under The term plastics here are mainly those from unsaturated Monomers produced polymers, but also others, with radicals Reactive plastics, in particular polyolefins, but also corresponding Paint materials, e.g. To understand polyurethane or acrylic paints.

Especially the compounds of the formula I are suitable for stabilizing Polyolefins, i. especially for Polypropylene and all variants of polyethylene (high pressure, medium and low-pressure polyethylene), Polyisobutylene, poly-4-methylpentene and their copolymers.

When additional Stabilizers can for the Polymer masses u.a. Antioxidants, e.g. sterically hindered phenols, secondary aromatic amines or thioethers (described, for example, in Plastics Additives, "Guards and Miller, 1985, p. 8-12), UV absorbers (especially 2- (2'-hydroxyphenyl) benzotriazole compounds, 2-hydroxybenzophenone compounds, 1,3-bis- (2'-hydroxybenzoyl) -benzolsalicylate, cinnamic acid derivatives and oxalic anilides), Antistatics, flame retardants, emollients, nucleating agents, Metal deactivators, biocides, fillers and pigments used become.

Under Low molecular weight alkyl are preferably radicals 1-4, in particular To understand 1 or 2 carbon atoms, come as "acyl" preferably the residues of formic, acetic or propionic acid into consideration.

All R _{8 are} preferably hydrogen.

genannt werden.The invention also relates to the novel compounds of the formula I.

to be named.

All R _{8 are} preferably hydrogen.

worin R₁ Wasserstoff, niedermolekulares Alkyl, niedermolekulares Alkoxy oder Acyl,
R₃ Sauerstoff, -NH- oder -N(C_1-4-Alkyl)-,
R₄ einen 3,5-di-(tert.butyl)-4-hydroxyphenylrest, einen ein- oder zweikernigen, heterocyclischen, gegebenenfalls Substituenten tragenden Rest aromatischen Charakters oder einen Rest der Formel a

R₅ einen gegebenenfalls Substituenten tragenden Phenylrest,
R₆ Hydroxyl oder niedermolekulares Alkoxy und
alle R₈ Wasserstoff oder Methyl
bedeuten.The invention also relates to the still new compounds of the formula I, they correspond to the formulas Ia and Ib

wherein R _{1 is} hydrogen, lower alkyl, lower alkoxy or acyl,
R _{3 is} oxygen, -NH- or -N (C _1-4 -alkyl) -,
R _{4 is} a 3,5-di- (tert-butyl) -4-hydroxyphenyl, a mono- or binuclear, heterocyclic, optionally substituent-bearing radical of aromatic character or a radical of the formula a

R _{5 is} an optionally substituent-bearing phenyl radical,
R _{6 is} hydroxyl or lower alkoxy and
all R _{8 is} hydrogen or methyl
mean.

The Compounds of the formula I can the plastics to be stabilized already in the production (implementation the monomers, preparation of the paints) are admixed. In the case the polyolefins can the compounds of formula I also with the powdery plastic mixed, fused and formed into thin moldings (e.g. Fibers, threads, Movies, tapes or thin Plates are processed, in which the chemical bond through Exposure made with high-energy visible or near UV light becomes. The exposure is generally dependent on the thickness of the Plastic, between about 100 and 400 hours, e.g. in the light of one Xenon lamp or performed in sunlight.

It can also voluminous moldings from according to the invention made with the compounds of formula I offset plastics and stabilized by exposure. In this case, the inside the moldings HALS compounds migrate slowly against the surfaces and there chemically by the exposure in use tied to the plastic. Thus, optionally destroyed HALS stabilizers on the surface repeatedly replaced and stabilized for much longer time extended.

in the In general, from 0.05 to 2.5%, in particular 0.1 to 0.5% of a or more compounds of the formula I, by weight of the plastic to be stabilized. This is, in comparison to the usual Application of HALS stabilizers a small amount.

To the exposure can the stabilizers (compounds of formula I) on physical Way, especially eluting, with whatever solvent, not be removed more from the plastics.

A preferred use of the stabilizers of the formula I is in polyolefins, by which all known plastics of this type are to be understood. It deserves mention to be that containing catalyst (residues / degradation products) Polyolefins can be stabilized equally according to the invention. An example for such Polyolefins is with a catalyst of III. Generation (Ziegler complex catalysts on magnesium halide support) made polypropylene, from the catalyst and residues not were removed. Generally speaking Polyolefins made with catalysts of all generations were reacted (see DE-OS 42 22 648) according to the invention.

in the In general, base-stabilized polyolefin is stabilized according to the invention. The base stabilization is generally carried out as known about 0.1% of a phenolic antioxidant and about 0.1% calcium stearate, based on the weight of the polyolefin.

The formation of the chemical bond between the compounds of formula I and the plastic molecules takes place with breaking of the double bond in the compound of formula I and attachment to ent speaking reactive carbon atoms in the polymer.

gemäss allgemein bekannten Verfahren hergestellt. Die Verbindungen der Formeln II und III sind bekannt.The compounds of the formula I are obtained by condensation of one mole of a compound of the formula II R ₂ -CH = C = (COOH) ₂ (II) or a functional acid derivative, eg a low molecular weight ester
or an acid halide, with 2 moles of a compound of formula III

prepared according to generally known methods. The compounds of the formulas II and III are known.

In In the following examples, the parts parts by weight and the Percentages by weight. The volume parts correspond to the volume equal parts by weight of water. The temperatures are in degrees Celsius specified.

EXAMPLE 1

schmilzt bei 121-123°.84 parts of para-methoxy-benzalmalonate are distributed with 154 parts of 1,2,2,6,6-pentamethyl-4-hydroxypiperidine in 80 parts of xylene, heated to 80 °, treated with 0.5 parts by volume of tetraisopropyl orthotitanate and, distilling off of the resulting methanol, stirred for 22 hours at about 140 °. The reaction solution is then cooled to 80 °, washed three times with 150 parts of water, the organic phase separated, the solvent is distilled off and the residue recrystallized from ethanol. The product of the formula

melts at 121-123 °.

EXAMPLE 2 (Reference)

Analogous to the information in Example 1 Benzalmalonsäurediäthylester and 1,2,2,6,6-pentamethyl-4-hydroxypiperidine esterified. The product obtained melts at 95-96 °.

EXAMPLES 3 to 5

25.9 Parts of 4-methoxy-benzalmalonic acid dichloride, prepared from 4-methoxy-benzalmalonic acid and thionyl chloride, is dissolved in anhydrous xylene, with 98 parts of 2,2,6,6-tetramethyl-4-aminopiperidine (Ex. 3, reference), 11.0 parts of 1,2,2,6,6-pentamethyl-4-aminopiperidine (Ex. 4), or 12.5 parts of 1-formyl-2,2,6,6-tetramethyl-4-aminopiperidine (Ex. 5, reference) condenses.

EXAMPLES 6 to 10

Analogously to the information in Example 1, 18.8 parts of diethyl 3,5-di-tert-butyl-4-hydroxybenzmalmalonate, (Ex. 6, Reference), 14.4 parts of 3,4-dimethoxy- Benzalmalonic acid diethyl ester (Ex. 7, Ref 8, reference), 16.2 parts of diethyl 4-phenylbenzalmalonate (Ex. 9, reference), or 12.7 parts of 1- (thienyl-2 ') - 2-benzoylbenzalmalonate (eg Ex. bis (ethoxycarbonyl) ethylene (Ex. 10, Reference) reacted with 18.8 parts of 1,2,2,6,6-pentamethyl-4-hydroxypiperidine.

EXAMPLES 11 and 12

Analogous to the information in Example 1, 84 parts of para-Methoxybenzalmalonsäuredimethylester with 160 parts of 1-methoxy-2,2,6,6-tetramethyl-4-hydroxypiperidine (Example 11, reference) or 180 parts of 1-n-octyloxy-2,2,6,6-tetramethyl-4-hydroxypiperidine (Example 12, reference) transesterified and isolated.

EXAMPLE 13

commercial Powdered polypropylene, base stabilized with 0.1 calcium stearate and 0.1% of a phenolic stabilizer, (Irganox 1010 from Ciba-Geigy) was mixed with 0.1% of the stabilizer according to Example 1, melted and processed into a film, thickness 0.1 mm. Ever a part of this Foil was exposed to the light of a xenon lamp for 50 hours and 200 hours exposed. These two samples and one unexposed film sample were eluted with dichloromethane and in the eluate the content of stabilizer certainly. In the unexposed sample, the entire stabilizer portion could eluted only 50% of the 50 hours exposed sample and the 200 hour exposed sample was not a stabilizer more elutable.

The Results with the according Stabilizers prepared in Examples 2 to 12 are convenient identical.

To protect the fixation thus obtained These HALS stabilizers make the plastic at least as good as non-chemically bound HALS stabilizers.

Claims (9)

Use of piperidine compounds of the formula I

wherein R _{1 is} methyl, R _{2 is} methoxyphenyl, R _{3 is} oxygen, -NH- or -N (C _1-4 alkyl) - and all R _{8 are} independently hydrogen or methyl, for the preparation with HALS compounds of chemically bonded plastics. Use of piperidine compounds of the formula I according to claim 1 in which R _{1 is} methyl, R _{2 is} 4-methoxyphenyl, R _{3 is} oxygen and all R _{8 is} hydrogen, for the preparation with HALS compounds of chemically bound plastics. Use of piperidine compounds of the formula I according to the claims 1 or 2 characterized in that 0.05 to 2.5 weight percent a radical of a compound of formula I chemically to the plastic be bound. Use of piperidine compounds of the formula I according to one of claims 1 to 3 gekenn characterized in that the chemical bonds to the plastic takes place by exposure. The compounds of the formula I

wherein R _{1 is} methyl, R _{2 is} methoxyphenyl, R _{3 is} oxygen, -NH- or -N (C _1-4 alkyl) -, and all R _{8 are} independently hydrogen or methyl. The compounds of formula I according to claim 5 wherein R _{1 is} methyl, R _{2 is} 4-methoxyphenyl, R _{3 is} oxygen and all R _{8 is} hydrogen. Process for the preparation of compounds of the formula I characterized by condensation of one mole of a compound of the formula II R ₂ -CH = C = (COOH) ₂ (II) their esters or acid halides, with 2 moles of a compound of formula III

wherein R ₁ , R ₂ , R ₃ and R _{8 are} defined as in claim 5. A process for the preparation of compounds of the formula I according to claim 7, characterized in that R ₁ , R ₂ , R ₃ and R _{8 are} defined as in claim 6. Plastics containing 0.05 to 2.5 percent by weight of one A radical of a compound of the formula I, according to one of claims 5 or 6 contained in chemically bound form.