Claims
- 1. A compound of the formula ##STR4## Wherein R.sub.2 is methyl or tert-butyl,
- R.sub.5 is hydrogen or methyl,
- R.sub.6 is hydrogen, alkyl of 1 to 3 carbon atoms or phenyl, and
- R.sub.8 is hydrogen or methyl.
- 2. A compound according to claim 1 wherein R.sub.8 is hydrogen.
- 3. 3-(3,5-di-tert-butyl-4-hydroxybenzylthio)butyraldehyde according to claim 1.
- 4. 3-(3,5-di-tert-butyl-4-hydroxybenzylthio)-3-phenylpropionaldehyde according to claim 1.
- 5. 3-(3,5-di-tert-butyl-4-hydroxybenzylthio)propionaldehyde according to claim 1.
- 6. 3-(3-methyl-5-tert-butyl-4-hydroxylbenzylthio)butyraldehyde according to claim 1.
- 7. 4-(3,5-di-tert-butyl-4-hydroxybenzylthio)-5-methyl-hexane-2-one according to claim 1.
- 8. 4-methyl-4-(3,5-di-tert-butyl-4-hydroxybenzylthio)pentane-2-one according to claim 1.
- 9. 4-(3-methyl-5-tert-butyl-4-hydroxybenzylthio)-5-methyl-hexane-2-one according to claim 1.
- 10. A composition of matter comprising a lubricating oil subject to oxidative, thermal and actinic degradation stabilized with an effective stabilizing amount of a compound of claim 1.
Parent Case Info
This is a continuation of application Ser. No. 743,224, filed on June 10, 1985, now abandoned, which in turn is a continuation of application Ser. No. 544,297, filed on Oct. 21, 1983, now abandoned.
Organic polymeric materials such as plastics and resins, and lubricating and mineral oils are subject to thermal, oxidative and photo-degradation. A great variety of stabilizers are known in the art for stabilizing a diversity of substrates. Their effectiveness varies depending upon the causes of degradation and the substrate stabilized. In general, it is difficult to predict which stabilizer will be most effective and most economical for any one area of application. For example stabilizer effectiveness in reducing volatility may depend upon preventing bond scission in the substrate molecule. Limiting embrittlement and retaining elasticity in a polymer or rubber may require prevention of excessive crosslinking and/or chain scission. Prevention of discoloration may require inhibiting reactions which yield new chromophores or color bodies in the substrate or stabilizer. Problems of process stability and incompatibility must also be considered.
It has now been determined that the 4-hydroxybenzylthio aldehydes and ketones of this invention possess an unusual combination of desirable properties which makes them particularly effective and useful as stabilizers. The compounds are particularly effective in protecting polyolefins, high impact polystyrene, rubbers such as polybutadiene and styrene-butadiene rubber, and other elastomers wherein retention of elasticity and inhibition of cross-linking, crazing, discoloration, odor formation and exudation are basic requirements.
It is the primary object of this invention to provide a class of hydroxybenzylthio aldehydes and ketones which exhibit a broad range of improved stabilization performance characteristics.
Various other objects and advantages of this invention will become evident from the following description thereof.
The compounds of this invention correspond to the formula ##STR2## wherein R.sub.1 -R.sub.8 independently are hydrogen, alkyl of 1 to 12 carbon atoms, cycloalkyl of 5 to 6 carbon atoms, phenyl, phenyl substituted by alkyl of 1 to 12 carbon atoms, aralkyl of 7 to 9 carbon atoms or said aralkyl substituted by alkyl of 1 to 12 carbon atoms.
Preferred compounds within the above structure are those wherein both R.sub.1 and R.sub.2 are in the ortho position to the hydroxy group.
As C.sub.1 -C.sub.12 alkyl, the R groups are staight-chain or branched alkyl, preferably with 1 to 8 carbon atoms, such as methyl, n-butyl, sec-butyl, tert-butyl, tert-pentyl, hexyl, 2-ethylhexyl, n-octyl and 1,1,3,3-tetramethylbutyl. Methyl and tert-butyl are particularly preferred.
When the R groups are aralkyl they represent benzyl, .alpha.-methylbenzyl or .alpha.,.alpha.-dimethylbenzyl. Substituted phenyl can be for example tolyl, mesityl or xylyl.
The preferred embodiments have R.sub.1 as tert.butyl, R.sub.2 as methyl or tert.butyl, R.sub.3 as hydrogen or methyl, R.sub.4 as hydrogen, methyl or isopropyl and R.sub.5 -R.sub.8 independently as hydrogen or methyl.
The stabilizer compounds are prepared by reacting a mercaptan of formula 1 with the unsaturated carbonyl compound of formula 2 in the presence of a catalyst ##STR3## wherein R.sub.1 -R.sub.8 are as previously defined.
The catalyst can be trialkyl amines such as triethyl amine, pyridine, sodium or potassium hydroxide, sodium or potassium carbonate, and the like. The synthesis can, if desired, be conducted in the presence of various solvent types such as alcohols, hydrocarbons, ethers, chlorinated hydrocarbons, aromatics, and the like. The reaction temperature generally ranges from -10.degree. C. to 150.degree. C. with a preferred range of about 20.degree. to 125.degree. C. The starting materials are items of commerce or can be prepared by known methods.
Compounds of this invention are particularly effective in stabilizing organic materials such as plastics, polymers and resins in addition to mineral and synthetic fluids such as lubricating oils, circulating oils, etc.
Substrates in which the compounds of this invention are particularly useful are polyolefins such as polyethylene and polypropylene; polystyrene, including especially impact polystyrene; ABS resin; elastomers such as e.g. butadiene rubber, EPM, EPDM, SBR and nitrile rubber.
In general polymers which can be stabilized include
1. Polymers of monoolefins and diolefins, for example polyethylene (which optionally can be crosslinked), polypropylene, polyisobutylene, polybutene-1, polymethylpentene-1, polyisoprene or polybutadiene, as well as polymers of cycloolefins, for instance of cyclopentene or norbornene.
2. Mixtures of the polymers mentioned under 1), for example mixtures of polypropylene with polyisobutylene.
3. Copolymers of monoolefins and diolefins with each other or with other vinyl monomers, such as, for example, ethylene/propylene, propylene/butene-1, propylene/isobutylene, ethylene/butene-1, propylene/butadiene, isobutylene/isoprene, ethylene/alkyl acrylates, ethylene/alkyl methacrylates, ethylene/vinyl acetate or ethylene/acrylic acid copolymers and their salts (ionomers) and terpolymers of ethylene with propylene and a diene, such as hexadiene, dicyclopentadiene or ethylidene-norbornene.
4. Polystyrene, poly-(p-methylstyrene).
5. Copolymers of styrene or methylstyrene with dienes or acrylic derivatives, such as, for example, styrene/butadiene, styrene/acrylonitrile, styrene/ethyl methacrylate, styrene/butadiene/ethyl acrylate, styrene/acrylonitrile/methyl acrylate; mixtures of high impact strength from styrene copolymers and another polymer, such as, for example, from a polyacrylate, a diene polymer or an ethylene/propylene/diene terpolymer; and block polymers of styrene, such as, for example, styrene/butadiene/styrene, styrene/isoprene/styrene, styrene/ethylene/butylene/styrene or styrene/ethylene/propylene/styrene.
6. Graft copolymers of styrene, such as, for example, styrene on polybutadiene, styrene and acrylonitrile on polybutadiene, styrene and alkyl acrylates or methacrylates on polybutadiene, styrene and acrylonitrile on ethylene/propylene/diene terpolymers, styrene and acrylonitrile on polyacrylates or polymethacrylates, styrene and acrylonitrile on acrylate/butadiene copolymers, as well as mixtures thereof with the copolymers listed under 5), for instance the copolymer mixtures known as ABS-, MBS-, ASA- or AES-polymers.
7. Halogen-containing polymers, such as polychloroprene, chlorinated rubbers, chlorinated or sulfochlorinated polyethylene, epichlorohydrine homo- and copolymers, polymers from halogen-containing vinyl compounds, as for example, polyvinylchloride, polyvinylidene chloride, polyvinyl fluoride, polyvinylidene fluoride, as well as copolymers thereof, as for example, vinyl chloride/vinylidene chloride, vinyl chloride/vinyl acetate or vinylidene chloride/vinyl acetate copolymers.
8. Polymers which are derived from .alpha.,.beta.-unsaturated acids and derivatives thereof, such as polyacrylates and polymethacrylates, polyacrylamide and polyacrylonitrile.
9. Copolymers from the monomers mentioned under, (8) with each other or with other unsaturated monomers, such as, for instance, acrylonitrile/butadiene, acrylonitrile/alkyl acrylate, acrylonitrile/alkoxyalkyl acrylate or acrylonitrile/vinyl halogenide copolymers or acrylonitrile/alkyl methacrylate/butadiene terpolymers.
10. Polymers which are derived from unsaturated alcohols and amines, or acyl derivatives thereof or acetals thereof, such as polyvinyl alcohol, polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, polyvinyl maleate, polyvinylbutyral, polyallyl phthalate or polyallyl-melamine.
11. Homopolymers and copolymers of cyclic ethers, such as polyalkylene glycols, polyethylene oxide, polypropylene oxide or copolymers thereof with bis-glycidyl ethers.
12. Polyacetals, such as polyoxymethylene and those polyoxymethylenes which contain ethylene oxide as comonomer.
13. Polyphenylene oxides and sulfides, and mixtures of polyphenylene oxides with polystyrene.
14. Polyurethanes which are derived from polyethers, polyesters or polybutadienes with terminal hydroxyl groups on the one side and aliphatic or aromatic polyisocyanates on the other side, as well as precursors thereof (polyisocyanates, polyols or prepolymers).
15. Polyamides and copolyamides which are derived from diamines and dicarboxylic acids and/or from aminocarboxylic acids or the corresponding lactams, such as polyamide 4, polyamide 6, polyamide 6/6, polyamide 6/10, polyamide 11, polyamide 12, poly-2,4,4-trimethylhexamethylene terephthalamide or poly-m-phenylene isophthalamide, as well as copolymers thereof with polyethers, such as for instance with polyethylene glycol, polypropylene glycol or polytetramethylene glycols.
16. Polyureas, polyimides and polyamide-imides.
17. Polyesters which are derived from dicarboxylic acids and diols and/or from hydroxycarboxylic acids or the corresponding lactones, such as polyethylene terephthalate, polybutylene terephthalate, poly-1,4-dimethylol-cyclohexane terephthalate, poly-[2,2-(4-hydroxyphenyl)-propane]terephthalate and polyhydroxybenzoates as well as block-copolyether-esters derived from polyethers having hydroxyl end groups.
18. Polycarbonates.
19. Polysulfones, polyethersulfones and polyetherketones.
20. Crosslinked polymers which are derived from aldehydes on the one hand and phenols, ureas and melamines on the other hand, such as phenol/formaldehyde resins, urea/formaldehyde resins and melamine/formaldehyde resins.
21. Drying and non-drying alkyd resins.
22. Unsaturated polyester resins which are derived from copolyesters of saturated and unsaturated dicarboxylic acids with polyhydric alcohols and vinyl compounds as crosslinking agents, and also halogen-containing modifications thereof of low flammability.
23. Thermosetting acrylic resins, derived from substituted acrylic esters, such as epoxy-acrylates, urethane-acrylates or polyester acrylates.
24. Alkyd resins, polyester resins or acrylate resins in admixture with melamine resins, urea resins, polyisocyanates or epoxide resins as crosslinking agents.
25. Crosslinked epoxide resins which are derived from polyepoxides, for example from bis-glycidyl ethers or from cycloaliphatic diepoxides.
26. Natural polymers, such as cellulose, rubber, gelatin and derivatives thereof which are chemically modified in a polymer homologous manner, such as cellulose acetates, cellulose propionates and cellulose butyrates, or the cellulose ethers, such as methylcellulose.
27. Mixtures of polymers as mentioned above, for example PP/EPDM, Polyamide 6/EPDM or ABS, PVC/EVA, PVC/ABS, PVC/MBS, PC/ABS, PBTP/ABS.
28. Naturally occuring and synthetic organic materials which are pure monomeric compounds or mixtures of such compounds, for example mineral oils, animal and vegetable fats, oil and waxes, or oils, fats and waxes based on synthetic esters (e.g. phthalates, adipates, phosphates or trimellithates) and also mixtures of synthetic esters with mineral oils in any weight ratios, which materials may be used as plasticizer for polymers or as textile spinning oils, as well as aqueous emulsions of such materials.
29. Aqueous emulsions of natural or synthetic rubber, e.g. natural latex or latices of carboxylated styrene/butadiene copolymers.
In general, the stabilizers of this invention are employed in from about 0.01 to about 5% by weight of the stabilized composition, although this will vary with the particular substrate and application. An advantageous range is from about 0.5 to about 2%, and especially 0.1 to about 1%.
The stabilizers of the instant invention may readily be incorporated into the organic polymers by conventional techniques, at any convenient stage prior to the manufacture of shaped articles therefrom. For example, the stabilizer may be mixed with the polymer in dry powder form, or a suspension or emulsion of the stabilizer may be mixed with a solution, suspension, or emulsion of the polymer. The stabilized polymer compositions of the invention may optionally also contain various conventional additives, such as the following.
2.1. 2-(2'-Hydroxyphenyl)-benztriazoles, for example, the 5'-methyl-, 3',5'-di-tert.butyl-, 5'-tert.butyl-, 5'-(1,1,3,3-tetramethylbutyl)-, 5-chloro-3',5'-di-tert.butyl-, 5-chloro-3'-tert.butyl-5'-methyl-, 3'-sec.butyl-5'-tert.butyl-, 4'-octoxy, 3',5'-di-tert.amyl-, 3',5'-bis-(.beta.,.beta.-dimethylbenzyl)-derivative.
2.2. 2-Hydroxy-benzophenones, for example, the 4-hydroxy-, 4-methoxy-, 4-octoxy, 4-decyloxy-, 4-dodecyloxy-, 4-benzyloxy, 4,2',4'-trihydroxy- and 2'-hydroxy-4,4'-dimethoxy derivative.
2.3. Esters of optionally substituted benzoic acids for example, phenyl salicylate, 4-tert.butyl-phenylsalicylate, octylphenyl salicylate, dibenzoylresorcinol, bis-(4-tert.butylbenzoyl)-resorcinol, benzoylresorcinol, 3,5-di-tert.butyl-4-hydroxybenzoic acid 2,4-di-tert.butyl-phenyl ester and 3,5-di-tert.-butyl-4-hydroxybenzoic acid hexadecyl ester.
2.4. Acrylates, for example, .alpha.-cyano-.beta.,.beta.-diphenylacrylic acid ethyl ester or isooctyl ester, .alpha.-carbomethoxy-cinnamic acid methyl ester, .alpha.-cyano-.beta.-methyl-p-methoxy-cinnamic acid methyl ester or butyl ester, .alpha.-carbomethoxy-p-methoxycinnamic acid methyl ester, N-(.beta.-carbomethoxy-.beta.-cyanovinyl)-2-methyl-indoline.
2.5 Nickel compounds, for example, nickel complexes of 2,2'-thio-bis-[4-(1,1,3,3-tetramethylbutyl)-phenol], such as the 1:1 or 1:2 complex, optionally with additional ligands such as n-butylamine, triethanolamine or N-cyclohexyl-di-ethanolamine, nickel dibutyldithiocarbamate, nickel salts of 4-hydroxy-3,5-di-tert.butylbenzylphosphonic acid monoalkyl esters, such as of the methyl, ethyl or butyl ester, nickel complexes of ketoximes such as of 2-hydroxy-4-methyl-phenyl undecyl ketoxime, nickel complexes of 1-phenyl-4-lauroyl-5-hydroxy-pyrazol, optionally with additional ligands.
2.6. Sterically hindered amines, for example bis-(2,2,6,6-tetramethylpiperidyl)-sebacate bis-(1,2,2,6,6-pentamethylpiperidyl)-sebacate n-butyl-3,5-di-tert.butyl-4-hydroxybenzyl malonic acid bis-(1,2,2,6,6-pentamethylpiperidyl)ester, condensation product of 1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, condensation product of N,N'-(2,2,6,6-tetramethylpiperidyl)-hexamethylendiamine and 4-tert.octylamino-2,6-dichloro-1,3,5-s-triazine, tris-(2,2,6,6-tetramethylpiperidyl)-nitrilotriacetate, tetrakis-(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarbonic acid, 1,1'(1,2-ethanediyl)-bis-(3,3,5,5-tetramethylpiperazinone).
2.7. Oxalic acid diamides, for example, 4,4'-di-octyloxyoxanilide, 2,2'-di-octyloxy-5,5'-di-tert.butyl-oxanilide, 2,2'-di-dodecyloxy-5,5'-di-tert.butyl-oxanilide, 2-ethoxy2'-ethyl-oxanilide, N,N'-bis (3-dimethylaminopropyl)oxalamide, 2-ethoxy-5-tert.butyl-2'-ethyloxanilide and its mixture with 2-ethoxy-2'-ethyl-5,4'-di-tert.butyloxanilide and mixtures of ortho- and para-methoxy-as well as of oand p-ethoxy-disubstituted oxanilides.
3. Metal deactivators, for example, N,N'-diphenyloxalic acid diamide, N-salicylal-N'-salicyloylhydrazine, N,N'-bis-salicyloylhydrazine, N,N'-bis-(3,5-di-tert.butyl-4-hydroxyphenylpropionyl)-hydrazine, 3-salicyloylamino1,2,4-triazole, bis-benzyliden-oxalic acid dihydrazide.
4. Phosphites and phosphonites, for example, triphenyl phosphite, diphenylalkyl phosphites, phenyldialkyl phosphites, tri-(nonylphenyl)phosphite, trilauryl phosphite, trioctadecyl phosphite, di-stearyl-pentaerythritol diphosphite, tris-(2,4-di-tert.butylphenyl) phosphite, di-isodecylpentaerythritol diphosphite, di-(2,4-di-tert.butylphenyl)pentaerythritol diphosphite, tristearyl-sorbite triphosphite, tetrakis-(2,4-di-tert.butylphenyl)-4,4'-diphenylylendiphosphonite.
5. Compounds which destroy peroxide, for example, esters of .beta.-thiodipropionic acid, for example the lauryl, stearyl, myristyl or tridecyl esters, mercapto-benzimidazole or the zinc salt of 2-mercaptobenzimidazole, zinc-dibutyl-dithiocarbamate, dioctadecyldisulfide, pentaerythritol-tetrakis-(.beta.-dodecylmercapto)-propionate.
6. Polyamide stabilizers, for example copper salts in combination with iodides and/or phosphorus compounds and salts of divalent manganese.
7. Basic co-stabilizers, for example, melamine, polyvinylpyrrolidone, dicyandiamide, triallyl cyanurate, urea derivatives, hydrazine derivatives, amines, polyamides, polyurethanes, alkali metal salts and alkaline earth metal salts of higher fatty acids for example Ca stearate, Zn stearate, Mg stearate, Na ricinoleate and K palmitate, antimony pyrocatecholate or zinc pyrocatecholate.
8. Nucleating agents, for eample, 4-tert.butyl-benzoic acid, adipic acid, diphenylacetic acid.
9. Fillers and reinforcing agents, for example, calcium carbonate, silicates, glass fibres, asbestos, talc, kaolin, mica, barium sulfate, metal oxides and hydroxydes, carbon black, graphite.
10. Other additives, for example, plasticizers, lubricants, emulsifiers, pigments, optical brighteners, flameproofing agents, anti-static agents, blowing agents and thiosynergists such as dilaurylthiodipropionate or distearylthiodipropionate.
US Referenced Citations (13)
Non-Patent Literature Citations (3)
| Entry |
| CA 77 89193a (1972)--Takano et al. |
| CA 64 17565f (1966)--Frisell et al. |
| CA 77 102977f (1972)--Yamamoto et al. |
Continuations (2)
|
Number |
Date |
Country |
| Parent |
743224 |
Jun 1985 |
|
| Parent |
544297 |
Oct 1983 |
|
Patent Grant
4618440
