CA2347260C - Polyamide composition stabilized with copper salt and an aromatic halogen compound - Google Patents
Polyamide composition stabilized with copper salt and an aromatic halogen compound Download PDFInfo
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- CA2347260C CA2347260C CA002347260A CA2347260A CA2347260C CA 2347260 C CA2347260 C CA 2347260C CA 002347260 A CA002347260 A CA 002347260A CA 2347260 A CA2347260 A CA 2347260A CA 2347260 C CA2347260 C CA 2347260C
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/04—Oxygen-containing compounds
- C08K5/09—Carboxylic acids; Metal salts thereof; Anhydrides thereof
- C08K5/098—Metal salts of carboxylic acids
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/02—Halogenated hydrocarbons
- C08K5/03—Halogenated hydrocarbons aromatic, e.g. C6H5-CH2-Cl
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/49—Phosphorus-containing compounds
- C08K5/51—Phosphorus bound to oxygen
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L77/00—Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Compositions of derivatives of such polymers
- C08L77/06—Polyamides derived from polyamines and polycarboxylic acids
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Abstract
Stabilized polyamide composition, characterized in that as stabilizer at least one copper salt and at least one organic halogen containing compound are contained, wherein the organic halogen containing compound is selected amount the group consisting of:
(d) aromatic compounds;
(e) aliphatic phosphates; and (f) paraffins;
or mixtures thereof, with the proviso that, if the aromatic compound is a brominated styrene oligomer the polyamide is not polyamide 4.6.
(d) aromatic compounds;
(e) aliphatic phosphates; and (f) paraffins;
or mixtures thereof, with the proviso that, if the aromatic compound is a brominated styrene oligomer the polyamide is not polyamide 4.6.
Description
POLYAMIDE COMPOSITION STABILIZED WITH COPPER SALT
AND AN AROMATIC HALOGEN COMPOUND
The present invention relates to stabilized polyamide compositions.
Polymers are degraded easily when heated by oxidation, which leads to embrittlement of the material and to mechanical failure of the products produced therefrom.
Therefore particular chemical compounds are added which can delay the time of embrittlement with different activity. These so-called antioxidants are mostly built on the basis of phenyl derivatives, amine derivatives or phosphorous derivatives. Specific variants of antioxidants are employed with polyamides. One in particular active class of compounds, which does not have any activity with other polymers, are the so-called copper stabilizers.
These types of stabilizing systems are long known and are used widely for the preparation of polyamides, for examples for polyamide filaments which are used for the production of tyre cord and for polyamide extrusion molding parts for technical employment, in particular in the area of technical engineering (automobiles) and the electronic industry (switches, printed circuit boards).
These copper stabilizers usually consist of two components. As a first component, a compound such as copper halide or other copper salts are employed. In order to be effective as antioxidants, as second component a halogen compound must be added in a large surplus. Used in this respect are in particular potassium iodide and also potassium bromide. The employed molar ratio of copper to halogen is typically 1:5-15.
The recommended amount is generally 30 to 200 ppm copper and accordingly 150 to 3,000 ppm halogen.
These copper stabilizers do show somewhat satisfying results with polyamides.
However, these commonly employed copper stabilizers do show some severe drawbacks.
z Polyamides take up (conditioning) approximately 3% water. If the temperature changes water soluble components are extracted from the polyamide to the surface, which leads to the formation of scale. If copper halides, potassium halides or other soluble halides are employed these will be extracted to the surface and will form a hygroscopic scale which will react mostly acidic. Therefore the tracking resistance will decrease- Wlth electric components this may lead to failure. If eontact with metals is given the contact places will endure increased corrosion. Requirements of the electronic industry and the automobile industry regarding the question of tracking resistance are therefore difficult to fulfil.
At the same time these stabilizers are diffilcult to disperse in the polyamide. When preparing stabilized polyamides it is important to make sure that the employed stabilizers are finely powdered and can be admixed with the polyamide very homogeneously.
On problem associated therewith is usually the tendency of the usually employed components to agglomerate. The raw materials must therefore be ground very finely and must be protected against reagglomeration. The addition Itself is usually very difficult to control, therefore usually a master batch will be produced which will be added. Even then such a heterogeneous mixture of solid particles in a melt Is never optimal, compared with the hypothetical case that the stab~Iizer itself would be meltable and could be dispersed homogeneously under working conditions, as is the case with phenoic, amine and other antioxidants. The crystalline partiGes of the stabilezer salts effect the physical properties of the polyamides negative, even if they ors finely dispersed. This does not only result from possible inhamogeneity but also from the fact that fine particles aci as crystallisation nuGei which result in a higher crystallinity in polymers. This can lead to negative side effects. The impact strength can for example decrease by 20 to 30%, compared with the initial value of the non-stabilized polyamide.
Usual stabilizing compounds furthermore lead in polyamides after conditioning often to a bluish or greenish discoloration. Polyamldes reinforced with fiber glass may furthermore show a brown coloration due to the formation of copper oxide, resulting from high sheer stress given during processing. In particular negative are variations of the discoloration during the production cycles, which will make the use of the produced materials for non-colored or colored products difiticult. Therefore such polyamldes are usually employed after black coloration.
Usual stabilizing compounds are often added during the polymerization as aqueous solution in order to optimise the dispersion. One drawback is however that this addition may lead to formation of state of metallic copper or of copper oxide on the metal surface of the employed vessels and melt extruders. This may lead to variation in coloration and therefore to the discontinuation of the production. During spinning of filaments scale formation at the nozzle is often encountered which will lead to the discontinuation of the process.
In view of these drawbacks several improvements were proposed.
EP-A-39o2T! discloses a stabilized polyamide 4.6 composition- This particular high melting point polyamfde can be stabilized by addition of an unsoluble copper salt and a halogen substituted organic compound. These compositions are suitable for electric or electronic uses.
GB-A-1131933 and GB-A-1143826 disclose stabilized linear polyamides, stabilized with a mixture of a copper compound, soluble in the polyamide, and a specific halogen containing organic aliphatic compound with at most 7 carbon atoms. These organic compounds have however a high volatility. This may lead to undesired embrittlement of the material due to how out of the organic compound.
Starting from the above described problems associated with the prior alt it is therefore the object of the present invention to provide a stabilized polyamide composition which does not show the above named drawbacks, while simultaneously improving the long term temperature stability.
This object is solved in accordance with the present invention by the provision of a stabilized polyamide composition, characterized in that as stabilizer at least one copper salt and at least one organic halogen containing compound Is contained, selected among the group consisting of (a) aromatic compounds ; (b) aliphatic phosphates; (c) paraffins; or mixtures thereof, with the proviso that if the aromatic compound is a bromine containing styrene oligomer the polyamide is not polyamide 4.6.
Surprinsingly it was found that such stabilized polyamide compositions do show improved properties and an increased long term temperature stability.
Furthermore the present invention provides a process for the preparation of a stabilized polyamide composition, comprising the mixing of at least one polyamide, at least one copper Bait and at least one organic halogen containing compound selected among the group consisting of (a) aromatic compounds ; (b) aliphatic phosphates; (c) paraffins; or mixtures thereof, with the proviso that if the aromatic compound is a bromine containing styrene oligomer the polyamide is not polyamide 4.6.
Furthermore the present invention provides the use of at least one copper salt and at least one organic halogen containing compound, defined as given above, for the stabilization of polyamida compositions.
Prefered are each time compounds (a) andlor (b).
The at least one pvlyamide in accordance with the present Invention may be any polyamide. Polyamides are polymers showing recurrent carbon amide groups -CO-NH-in the polymer backbone. Polyamides are made from (a) amino cart~oxylic acids and their functional derivatives, for example lactames; or from (b) diamines and dlcarboxylic acids or their functional derivatives.
By varying the monomer units polyamldes are obtainable in a broad variety. In accordance with the present invention all polyamfdes may be stabilized, for example copolyamides or homopolyamides. Usable are furthermore block copolymers of polyamides and polyethers and other polymer modified polyamides. The most common types are polyamide 6 from e-caprolactam and polyamide BB from hexamethylene diamine and adipidic acid. Other important polyamides are potyamide 610, pofyamide 11, polyamide 12, PACM-12 , MPB-I, PPD-T and the aramides_ It is furthermore possible to use blends of polyamides with other polymers.
How ever, the stabilizing compounds may excert negative effects with respect to the blend components.
Therefore these most be chosen carefully.
In accordance with the present invention any copper salts may by used.
Preferred are salts of mono- or divalent copper with inorganic or organic acids. Examples of suitable copper salts are copper (I) salts, such as CuJ, CuCI, ar GuGN, copper (II) salts, such as CuCl2, CuBr2, Cu-acetate, Cu-sulfate, Cu-stearate, Cu-propionate, Cu-butyrate. Cu-lactate, Cu-benzoate or Cu-nitrate, as well as ammonium complexes of the above given salts.
Furthermore compounds such as Cu-acetylacetonate or Cu-EDTA may be employed.
It is furthermore possible to use mixtures of different copper salts. Optional Cu powder may be used. This reacts with poiyamlde melts under formation of copper compounds.
Preferred are Cu (I) halides and Cu-salts of organic acids, in particular preferred are CuJ
and Cu-acetate.
The amount of copper , used in the stabilized polyamlde compositions is not limited, as long as the mechanical properties of the polyamide are not affected detrimental. Usually the amount is between 10 and 1000 ppm copper, based on the total composition.
Preferably 20 to 700, in particular 50 to 150 ppm copper are employed.
As organic halogen containing compound of the invention any aromatic andlor any aliphatic phosphate andlor any paraftln may be employed. Preferred are aromatic bromine containing compounds, bromine containing aliphatic phosphates and chlorine or bromine containing paraffines. The molecular weight of the employed compounds of the invention is not limited. It should be selected so that the compount is not too volatile, the compound can be mixed easily and homogeneously with the polyamide and shows only minor migration tendency In the final composition. Preferred are further bromine containing aromatjc oltgomeric epoxy resins, in particular compounds on the basis of tetrabromobisphenol-a.
Examples of usable paraffins era halogenated, in particular fluorinated, chlorinated or brominated paraffins. Usable are furthermore soft as well as hard paraffins.
Preferred are compounds such as chloroparaffins (for example with an average formula of CzaH=aCl,s ), teflon waxes (for example with an average formula of CzoH~FZO) and Viton copolymers (copolymers of hexafluoroprapylene and vinylidene fluoride).
Examples of suitable compounds are-Tris-{neobromopentyl)phasphate (phosphate 1), dibromodfoxaphosphorinane derivatives and chlorine containing polyphosphonates and dekabr~omophenyl, dekabromophenylether, polydibromostyrene, tetrabromoblsphenol-A, chlorinated and brominated styrene oligomers, tetrabromobisphenol-A-derivatives, such as (EP-ollgomer 1) and BEB6000 (EP-oligomer 2), which structures are given below, and chlorinated dimethanidibenzo(a,e)cacloocten-derivatives. Preferred are tris-(dibromoneopentyi)phosphate and dekabromophenyl and polydibromostyrene. It is furthermore possible to use mixtures of organic halogen containing compounds.
The addition amount of the halogen containing organic compound is usually below 10 wt°!°_ Typically such amounts are added so that 50 to 30,000 ppm halogen are present, preferably 100 to 10,000 ppm, snare preferably 500 to 7 500 ppm, based on the total composition.
accordingly usually a ratio of copper to halogen In the stabilized polyamide compositions of from 1:1 to 1:3000 is obtained. Preferred is the area from 1.2 to 1:100, In particular the range from 1:5 to 1:15 (based on the molar ratio).
Higher addition amounts usually do not lead to an increase of the stabilization effect, poiyamides containing more than 5~° organic halogen containing compounds do have a significant lower stability. They show increased cleavage of polymer chains, which leads to premature embrittlement of the products and to strong discoloration.
Preferably the content of organic halogen containing compound is less than 3 wt%, in particular less than 1 wt%.
The above defined copper salts and organic halogen containing compounds w~l ~
be named stabilizer components in the following.
Polyamlde compositions in accordance with the present invention show improved long teen temperature stability, improved tracking resistance and lower discoloration. These advantages of the compositions of the present invention are deemed to be due to the synergistic effect of the organic halogen containing compounds, which must be added in minor amounts only.
The tracking resistance, which is determined as CTI-value is improved greatly with the use of the organic compounds. Accordingly the area of practice for the polyamide composi~ons in accordance with the invention is broadened to produces which are used in the electro or electronic industry.
Polyamides for electrical products should possess CTI-values of 600, at least however of 550. This value is reached with pure polyamide. The CTI-value is determined in accordance with DIN-IEC 112.
The polyamide compositions in accordance with the present invention further show, compared with usual copper/halogensalt-stabilizers, improved electrical strength.
The used organic compounds show, compared with halogen salts an improved dispersion ability in the polymer melt. Therefore a complicated homogenisation can be omitted. If at the same dme a copper salt such as copper stearate is employed, the stabilizer itself is meltable and therefore easy to disperse in the polyamide_ The stabilizing components are compatible with ail sorts of pofyamines.
Therefore blooming at the processing apparatuses (nozzles, extruders, molds) and the produced parts and filaments does not occur.
Furthermore the polyamide compositions in accordance with the present Invention do show only very limited tendency towards discoloration. In particular wit fiberglass reinforced polyamides with conventional copper stabilizers discolorations were sv strong that these compositions wefe only usable after black coloration. It is therefore surprising that this discoloration occurs with the polyamide compositions according to the present invention only to a minor extent, if at all. It is possible to obtain compositions colored with pigments without color deviations- Even TiOz colored compositions maintain the clear white color. This opens a new application field for colored polyamides in areas where improved long term thermal stability is required, so long only obtainabiy with common stabilizers having the drawback of strong discoloration.
The polysmide compositions in accordance with the present invention therefore have the advantage of fmprovef long term temperature stability while being at the same time colorable with pigments, without the danger that the usual own discolorations alter the pigment coloration.
For coloration of the polyamide composmons in accordance with the present invention all common pi~ments are suitable, such as titandloxld~, lead white, zinc white, lipone, antimony white, carbon black, iron black, mangan black, cobalt black, antimony black, lead chromate, mennige, zinc yellow, zinc green, cadmium red, cobalt blue, Berlin blue, ultramarine, mangan violet, cadmium yellow, schweinfurt green, molybdenum orange, molybdenum red, chromium orange and chromium red, iron oxide red, chromoxide green, strontium yellow, chromoxidr~ green, molybdenum blue, chalk, acker, umbra, green soil, terra dl sienna and graphite_ The poiyamide compositions in accordance with the present invention are furthermore excellent concerning theft stability regarding hydrolysis. They show improved long term stability under acidic and basic conditions, vis-a-vis salt solutions, glycol water mixtures and hot fats and oils and organic solvents. Accordingly, the usually recognised decrease of mechanical strength (impact strength, tensile strength) and the tendency towards embrittlement of the poiyamides is drastically reduced and the long term durability enhanced. Compared with usually employed stabilizers, such as phenolic or amine compounds or common copperfialogen salt-stabilizers, improved effects are obtained.
The polyamide compositions in accordance with the present inventJon can furthermore be combined without limitations with further additives, such as lubricants, plasticiters, crystallization accelerators and pigments without detrimentally effecting the desired stabilization effect. In some cases even the used additives are stabilized against thermal decomposition or discoloration in polyamides. Therefore, polyamides mixed with plasticizers, such as BBS, or with waxes, such as montanates, no longer show a high tendency to ageing, when employed in polyamide compositions In accordance with the present invanticn.
Poiyamldes containing glass bowls, fiber glass, mineral additives or other reinforcing agents furthermore show, compared with common stabilizers, a significantly improved long-term thermal ageing stability.
The polyamide compositions in accordance with the present invention may contain furthermore usual fillers and reinforcing agents. Examples of suitable fillers and relnforsing agents are glas materials In the form of fibers, ravings, beads or powders, oxidic materials, such as sflics, alumina or aluminum silicates as well as graphite or plastic fibers or whiskers.
The above described advantages of the polyamlde compositions of the pres~nt invention make it possible to use them for the preparation of fibers and for parts in the electric or electronic industry, mainly plug-in parts, plates (supports for electric r~~ntacts) and casing parts.
Furthermore, the stabilized polyamide compositions in accordance with the present invention were evaluated in order to deteimlne whether any further improvement of the discoloration tendency could be achieved. Surprisingly, it was found that a further reduction of the discoloration could be achieved by the addition of organic phosphites or inorganic phosphonates or inorganic hypophosphltes. These substances ara known as color stabilizers in polyamides. It was, however, also known that these color stabilizers could lead ofken to the formation of copper oxides with copper salts.
Therefore, a grey discoloration or brown/ black discolorations occurred. Therefore, it was surprising that the combination in accordance with the present inv~ntlon does not lead to any discoloration and that, furthermore, the blue discoloration, occurring sometimes after conditioning could be reduced by the addition of organic phosphites ar inorganic phosphonates or inorganic hypophophites. The slight discoloration occurring during this mixing can be cross dyed for the preparation of color stable polyamides, It was furthermore found that this addition furthermore retards the ageing of the polyamides during thermal storage. This effect is particularly significant with organic phosphates.
The employable organic phosphates are esters of the phosphoric acid.
Employable are aliphatic as well as aromatic or mixed esEers. Typical examples are, for example, dimethyl and diethyl phosphlte, trimethyl and methyl phosphate as well as the additives known in the plastic processing Industry. Typical examples are Tris(2,a-dl~t-butylphenyl)phosphite (Phosphate 20), Bis(2,4-di-t-butylpheny!)pentaerythritoldi-phosphate (Phosphate 21 ), Tetrakis(2,4-di-t-butylphenyl)4,4'-biphenylendiphosphonite (Phosphate 23), Dlstearylpentaerythritoldiphosphite, Diisoactylphosphite, Distearylphosphite, Triisodecylphosphlte, Triisooctylphosphite, Trilaurylphosphite, Tristearylphosphite, Tris(dipropylenglycol)phosphlte, Diphenylphosph~te, Trisnonylphenyfphosphite, Triphenylpho5phite, Trls(p-nonylphenyl)phosphite. These compounds are available under the tradenames Irgafos, Alkanox and Weston from the companies Ciba, Weston and The Great Lakes. Preferred are, in peritcular, Phosphate 20, Phosphate 21, Phosphate 22 and Phosphate 23.
Usable inorganic phosphonates are salts of the phosphonic acid. Employable as salt builders are alkali metals, earth alkali metals and ail other usual metals.
Preferred are, in particular, lithium, potassium, sodium, magnesium, calcium, strontium, barfum and aluminum, in particular preferred are sodium, potassium, magnesium and calcium. A
preferred phosphortate is disodium hydrogen phosphonate.
The usable inorganic hydrophosphltes are salts of the hypophosphortc add.
Concerning the salt building, it Is referred to the above metals listed in connection with the inorganic phosphanates. The sodium salt of the hypophosphoric acid is a preferred example of the employable hypophosphites_ The addition amount of the above given additives is between 0.005 and 1.0% (50 to 10,000 ppm), preferably from 0.05 to 0.2% (500 to 2000 ppm) and in particular preferably from 0.075 to 0.15% (750 to 1500 ppm). These amounts relate everytime to the total composition.
The organic phosphltes to be used are preferably mekable, processing stable and stable against extraction. This ensures that no phosphoric acid will be cleaved which may have disadvantageous effects for the total composition. The above given organic phosphltes, in particular the Phosphates 20, 21, 22 and 23, satisfy the requirements excellently.
Therefore, these compounds are particularly preferred.
It has, furthermore, been recognised during the preparation of the stabilized polyamide compositions in accordance with the present invention that the addition of the organic phosphate, the inorganic phosphonates and the inorganic hypophosphites should preferably occur only after the preparation of the basic composition stabilized with the stabilizing components.
If a stabilized polyamide composition in accordance with claim 1 is produced first and if the organic phosphate, the inorganic phosphonate or the inorganic hypaphosphite is added only thereafter during an additional step, no discoloration occurs. The above described procedure is in particular efPeciive with inorganic phosphonates.
The organic phosphite, the inorganic phosphonate or the inorganic hypophvsphite can be added as such or In the form of a masterbatch. Concerning the masterbatch technology it is referred to the previous disclosure in this respect, the same principles are valid here.
The production of the polyamide compositions is carried out usually by mixing at least one polyamide with at least one copper compound and at least one halogen containing compound, selected as defined in claim 1.
It is possible to mix the components using.common apparatuses, namely polyamide and stabilizing compounds are mixed with one another and are fused. It is preferred, however, to first fuse the polyamide and to mix in subsequently the stabilizing components. It is even more preferred to add the stabilizing compound in the form of a master batch to the molten polyamide. This simplifies in particular the metering of the stabilizing components.
Suitable mixing apparatuses are known to the person skilled in the art and comprise mixing rollers, discontinuous kneaders, continuous extruders and kneaders and static mixers. Preferred is the use of continuous extruders, single screw extruders as well as double screw extruders, which allow a good mixing. Usually the polyamide will be fused in the extruder, the stabilizing component can be metered in later through suitable openings. This process as well as the apparatuses for these purposes are known to the person skilled in the art.
It is furthermore possible to add the stabilizing components during the production of the polyamides, for example by adding them to the monomer mixture. This leads to a very good dispersion without any further mixing step which reduces the production costs and the production time.
If a master batch of the stabilizing components is used for the production of the polyamide compositions in accordance with the present invention, the master batch can be produced in discontinuous mixers which allow a very good homogenous mixing, for example a Buss-kneader. However, usually continuous mixers are used such as double screw extruders or ZSK-extruders. The matrix material ampioyed is usually the same polyamide which will b~ mixed later with the master batch It is, however, also possible to usa another polyamide or another polymer. The concentrakion of stabilizing components depends from the compatability of the matrix material and from the desired final concentration in the final blend and from good metering ability. Masterbatches with concentrations up to 50% can be obtained, for example from a mixture of CuJ
and polydibromostyrene (1:10).
In the following some preferred combinations of copper salts and organic halogen containing compounds are given.
Copper compound Organic halogen compound CuJ Tris-(tribromoneopentyl)phosphate CuJ 1,2,3-indioxaphosphorinane-5,5-bis(bromomethyl)-2-methoxy-2-oxide CuJ Polydibromostyrene CuJ Dekabromophenylether CuCl2 Tris-(tribromoneopentyl)phosphate Cu-acetate Tris-(tribromoneopentyl)phosphate Cu-acetate Tris-(tribromoneopentyl)phosphate Cu-acetate EP oligomer 2 CuJ EP oligomer 1 CuJ Dechlorane plus CuJ Chloroparaffin av. C20H24C118 CuJ Teflon wax av. C20H22F20 Cu (II) stearate Phosphate 1 The Ep oligomers in particular possess high temperature stability. Furthermore their combinations with copper compounds are cheap.
Polydibromostyrene and EP oligomer 1 are suitable for the preparation of highly concentrated masterbatches. Masterbatches up to 50% of these compounds can be prepared.
EP oligomer 2 can only be introduced up to 10%. Due to a reaction of the EP-end groups with amino groups in the polyamide a strong increase of the viscosity is encountered. This chemical reaction however has the advantage that the dispersion and bonding in the final product is increased.
12a In another aspect, the present invention provides use of at least one copper salt and at least one organic halogen containing compound for the stabilization of polyamides, wherein the organic halogen containing compound is selected among the group consisting of: (a) aromatic compounds; (b) aliphatic phosphates; and (c) paraffins; or mixtures thereof, with the proviso that, if the aromatic compound is a brominated styrene oligomer the polyamide is not polyamide 4.6, and with the proviso that the organic halogen containing compound is not an iodide containing compound.
In another aspect, the present invention provides a polyamide composition, characterized in that as stabilizer at least one copper salt and at least one organic halogen containing compound are contained, wherein the organic halogen containing compound is selected among the group consisting of: (a) aromatic compounds; (b) aliphatic phosphates; and (c) paraffins; or mixtures thereof, with the proviso that, if the aromatic compound is a brominated styrene oligomer the polyamide is not polyamide 4.6, and with the proviso that the organic halogen containing compound is not an iodide containing compound, wherein said copper salt is in an amount of 10 to 1,000 ppm, wherein said organic halogen is in an amount of 50 to 30,000 ppm, and wherein said paraffins comprise 7 or more carbon atoms.
In another aspect, the present invention provides a method for the preparation of a stabilized polyamide composition, characterized in that at least one polyamide, at least one copper salt and at least one organic halogen-containing compound, selected among the group consisting of: (a) aromatic compounds; (b) aliphatic phosphates; and (c) paraffins; or mixtures thereof are mixed with one another, with the proviso that, if the aromatic compound is a brominated styrene oligomer the polyamide is not polyamide 4.6, and with the proviso that the organic halogen containing compound is not an iodide containing compound, wherein said copper salt is in an amount of 10 to 1,000 ppm, wherein said organic halogen is in an amount of 50 to 30,000 ppm, and wherein said paraffins comprise 7 or more carbon atoms.
In another aspect, the present invention provides use of at least one copper salt and at least one organic halogen containing compound for the stabilization of polyamides, 12b herein the organic halogen containing compound is selected among the group consisting of: (a) aromatic compounds; (b)aliphatic phosphates; and (c) paraffins;
or mixtures thereof, with the proviso that, if the aromatic compound is a brominated styrene oligomer the polyamide is not polyamide 4.6, and with the proviso that the organic halogen containing compound is not an iodide containing compound, wherein said copper salt is in an amount of 10 to 1,000 ppm, wherein said organic halogen is in an amount of 50 to 30,000 ppm, and wheren said paraffins comprise 7 or more carbon atoms.
The following examples illustrate the invention.
The samples tested in the following examples have been prepared and tested as follows.
Preparation of samples Stabilizer mixtures and Ca-stearate as lubricant are mixed with polyamide granules and melted in an extruder. The mixture is homogenized in the extruder and extruded continiousfy Subsequently granules are formed. Cu concentration was always 100 ppm, halogen concentration 1000 ppm (0.1~) and Ca-stearate concentration 0.3%.
After drying the granules were formed into test: samples using an Infection molding apparatus for measuring impact strength (DIN 53453) and bending strength (DIN 53452).
Heat agoing DIN 53497 and DIN 53446 The previously prepared test samples were put in an heat oven at 130, 150 and 185°C
and were stored at these temperatures until measurements have fallen under 50%
of the initial values. The period until this value was taken as hatftime and is the value for the heat ageing stability of the polyamide. This value demonstrates the effect of the employed stabilizers. Since many polyartiides age very rapidly without stabilization (24h at ~ 50°C) a use of these materials without stabilization is often not possible.
Tracking resistance (CTI-values) Test samples werde produced of a size of 3x5 cm (3mm thickness; infection molding) and tested in accordance with DIN-IEC 112.
Color determination Discoloration of test samples was evaluated optically. In addition the color intensity was evaluated with the determination of the brightness (DIN 6174; DIN 5033, Part 1-7).
Example 1 Stabilization of PA 6 , heat ageing at 150°C. Compatision with other copper stabilizers, addition amount 100 ppm copper. 1000 ppm halogen. Measurement of Impact strength until value decreases to 50% of Initial value (half value measurement);
measurement of tracking resintance (CTl-value); color after molding and after conditioning, color determination (CIE Lab values; DIN 8174}.
Table 2 Type CompositionHalftime CTI-value DiscolorationDiscoloration (h) after after formation conditioning 1 ComparisonPA 6 24 600 colorless Colorless (natur) 2 ComparisonCuJ/KJ 1100 450 colorless Light green 3 ComparisonCu- 750 400 colorless Light blue acetate/KBr 4 ComparisonCu- 800 450 Yellow-ishBlue green stearate/KJ
Invention CuJ/PDBS 850 525 yellowish yellowish 6 Invention CuJ/DBDP 850 550 Yellowish Blue green E
7 Invention CuJ/ 1200 550 colorless Blue green Phosphat 8 Invention CuJI 900 550 yellowish Blue green Phosphate 9 I InventionCuJ/TBBA 900 550 colorless Blue green EP
oligomer Invention I Cu-acetate/800 525 colorless Light blue TBBA EP
oligomer 11 Invention Cu(II) 1100 500 beige ochre acetate!
phosphate 12 Invention CuClz/ 1000 550 beige ochre phosphate 13 Invention CuCI/ 900 550 beige Light blue phosphate 14 Invention CuBr / 900 600 colorless Light blue phosphate 15 Invention CuC03 800 600 colorless Light blue phosphate 16 Invention CuJ/ 950 550 brown Brown chloroparaffin 17 Invention CuBr/ I 900 600 beige Light brown dechlorane plus 18 Invention Cu- 850 600 beige Light brown stearate/
dechlorane plus Table 2 (coot.) after molding after conditioning Type DiscolorationBrightnesDiscolorationBrightnesGreen-red Blue-yellow L-value L-value a-value b-value 1 Colorless 68.2 Colorless 69.3 -3.2 -1.8 2 ~ Colorless 68.3 Light green66.2 -11.7 4.2 3 Colorless 69.1 Light blue 68.2 -7.8 -1.5 4 I Yellow-ish 67.5 Blue green 65.0 -7.7 2.9 5 Yellow-ish 68.8 Blue green 66.7 -9.6 -2.4 6 Yellow-ish 69.2 Blue green 68.7 -5.9 -3.2 7 Colorless 69.8 Blue green 69.2 -8.9 -1.8 8 Yellow-ish 67.3 Blue green 66.7 -5.6 6.9 i 9 Colorless68.8 Blue green68.3 -8.5 0.6 ~
Colorless69.2 Light ~ 68.4 -8.8 4.0 blue 11 Beige 61.78 Ocker 59.81 ~.5 4.6 12 Beige 63.47 Ocker 61.41 -4.4 2.6 ~
13 Colorless69.55 Light 67.08 -7.7 -2.1 blue .
14 i ColoHess 68.47 Light 57.71 -6.9 -2.4 blue Colorless68.09 Light 67.32 -7.2 -2.0 , blue 16 Brown 22.99 Brown 22.61 2.6 6.9 17 Beige 46.42 Light 43,80 0.8 4.2 brown 18 Beige 49.81 Light 47.36 -3.7 2.8 brown .. .,~a.a. ' p4~ ~ ~°~. ~] . Q °~.~~ EP-Oligomer 1 a~ ,, °~~ ..
EP-Oligomer 2 These results show that the polyamide compositions, stabilized in accordance with the invention do show slgnlflcantly improved tracking resistance and at the same time prolonged thermal stability. Discolorations are not detrimental for a later coloration of the samples of the invention.
Further experiments were carried out as above using 1000 ppm phcsphite or phosphate_ Samples and results are given in table 2a Table 2a Type Composition Halftimevalue DiscolorationDiscoloration (h) after after molding conditioning 19 InventionCuJI 1150 600 colorless Light blue phosphate phosphits (23) 20 Invention(CuJ/ 1100 600 Colorless Light blue Phosphate 1 ) in polyamide/
phosphite (20) 21 Invention(CuJ/ 1200 600 Colorless Light blue PDBS) in polyamide/
phosphite (21 ) 22 InventionCuJ/ 1100 550 Colorless Light blue PDBS) in polyamide/
disodium hydrogen phosphate 23 InventionCu(II) 900 600 colorless Light blue stearate/
phosphate / phosphite (21 ) After molding after conditioning Type DiscoloratiBrightnessDiscoloratiBrightnessGree-redBlue-on L-value on L-value a-value yellow j b-value 19 colorless70.07 Light 6B.21 -7.7 -2.B
blue 20 Colorless73.68 Light 71 _78 -3.3 blue -8.2 21 Colorless69.96 Light 67.95 -2.7 blue ! -7.4 I
22 Colorless68,89 Light 66.21 -1.0 blue '-5.9 23 ' 68.32 66.09 -1.8 colorless ~ Llght - I -6,3 blue ~
Example 2 Stabilization of PA 66 (natur), heat ageing test at 165'C, Composltlons and measurements as In example 1 Additional experiments with 1000 ppm phosphite or phosphonate were done also.
Table 3 Type ComposttioHatftirneCT1-valueDiscoloratioDiscoloratio (h) n n after n after formationconditlonin ComparlsioPA 66 12 600 Colorlesscolorless n (natur) ComparisioCuJ/KJ 140 450 ColorlessLight ~ green n CompansioCu- 90 400 ColorlessLight ~ acetate/KBr blue ComparisioCu- 90 450 YellowishBlue green n stearate/KJ
t Invention S25 YellowishBlue CuJ1 green PDBS
~ 130 ' inventionGuJI 130 550 Yellowish Blue green DBDPE
~
InventionCuJI ~ 480 550 Colorless Blue green Phosphatl InventionCuCI 150 475 bei a brown ~ g z phosphate ' ( InventionCuGl/ 190 475 Colorises Light blue Phosphat 1 s InventionCu-acatatel350 ! 475 ~ beige I brown Phosphat 1 ~
InventionCu-acetate/120 525 colorless Light ~ blue ~
l InventionCuJI 150 550 colorless Blue green EP- l Oiigomer InventionCuJI 330 550 beige ocker I
dechlorane l ~
plus InventionCuJI 370 550 brown brown chloro paraffinI
~ ~~
InventionGuJI 450 BOO Colorless Light blue phosphate l 1l ~ l phosphite (20) l Invention(CuJ/ ~ 450 600 Colorless Light blue I
~ ~
PDBS) in polyamide/
phosphate~ ;
I (20) ~ t ' Also these samples in accorbance with the present invention do show improved tracking resistance and thermal stability so that the application of these samples in the electronic area is possible-Example 3 Stabilization of PA 66, reinforced with 30°!° fiberglass (GF30), experiments as in example 2. Halftime values relate to bending strength. Addition amount of phosphate or phosphate 1000ppm.
Table 4 Type CompositionHalftime CTI- DiscolorationDiscoloration (h) value after moldingafter conditioning Comp. PA 66 GF30 120 550 Colorless Colorless Comp. CuJ/KJ 1200 450 Yellowish Blue green Comp. Cu-acetate/900 400 brown Brown KBr InventionCuJ/PDBS 900 525 yellowish Yellow green InventionCuJ/ 1800 525 Colorless Yellowish phosphate InventionCuJI EP 1300 525 Colorless Light green oligomer InventionCuJ/ 1300 550 Colorless Light green Phosphate phosphate (2) invention(CuJIPDBS) 1400 550 Colorless Light green in polyamide/
phosphate (21) Samples in accordance with the invention do show, as in previous examples CTI-values allowing the use in electric parts.
Example 4 Stabilization of PA 66 (natur) and PA 66 GF30 with copper stabilizers, addition of 100 ppm copper, 1000 ppm halogen, 1000 ppm phosphate or phosphonate. Measurement of initial impact strengths: Izod with PA 66 (natur) and Charpy (not notched) with PA 66 GF30.
Table 5 Type Composition Halftime at Impact strength 165C (h) (kJ/m2) Comp. PA 66 GF30 120 45 (Charily) Comp. CuJ/KJ 1200 35 (Charily) Invention CuJ/ Phosphate 1800 41 (Charily) Comp. PA 66 (natur) 12 5.5 (Izod notched) Comp. CuJ/KJ 140 4.0 (izod notched) Invention CuJ/ Phosphate 480 5.5 (lzod notched) Invention CuJ/ Phosphate 1400 35 (Charily) j 1/ j phosphite (20) in PA
Invention (CuJ/ PDBS) in 1200 45 (Charily) Polyamide 66/
phosphite (21 ) Example 5 Extraction stability of PA 6 and PA 66 GF30 with water and ethanol. Evaluation in accordance with DIN 53738. Stabilization with 100 ppm copper and 1000 ppm halogen, 1000 ppm phosphite or phosphonate. Determination of extract composition after 16h reflux.
Table 6 Type Composition Amount of Composition of extract (%) extract Invention/Vl/aterPA 66 natur CuJ/ 0.3 No copper or halogen Phosphate 1 or P
InventionNVaterCuJ/ Phosphate 0.3 No copper or halogen phosphite (21 or P
) PA66 natur InventionNVaterCuJ/ Phosphate 0.2 No copper or halogen PA66 GF30 or P
Invention/WaterCuJ/ Phosphate 0.2 No copper or halogen Phosphite (21 or P
) PA 66 Invention/EthanolCuJ/ Phosphate I 0.6 No copper or halogen PA6 natur or P
Invention/EthanolCuJ/ Phosphate 0.6 No copper or halogen phosphite (20) or P
natur Invention/EthanolCuJ/ PDBS /PA6 0.5 No copper or halogen GF30 or P
Invention/EthanolCuJ/ Phosphate 0.5 No copper or halogen phosphite (20)/ or P
Example 6 Hydrolysis stability of PA 66 GF30, decrease of mechanical properties (hardness and bending strength) after storage In 100% glycol, 48h at 135°C. 150 ppm copper, 1500 ppm halogen, 1000 ppm phosphite or phosphonate.
Table 7 Type compositionCTI- Ball- Bending Ball- Bending value pressurestrength pressure strength hardness hardness (aS) (aS) Comp. CuJ/KJ/ 450 141 276 91 130 KBr InventionCuJ/ ~ 525 140 280 94 134 Phosphate i Invention(CuJ/ 525 139 278 92 ~ 132 PDBS) in polymide/
Phosphite (21 ) InventionCuJ/ 525 140 278 95 135 Phosphate Phosphite (20) i (aS): after storage, ball-pressure hardness measured in accordance with ISO
2039/1, bending strength measured in accordance with DIN 53456 Samples in accordance with the present invention and comparative examples show, that the polyamide compositions of the present invention show improved long term temperature stability and improved maximum temperature durability and improved tracking resistance. Also the tendency towards discoloration is reduced, compared with conventional polyamide compositions. Initial impact strength is affected by use of stabilizers in form of salts (CuJ/KJ). Substitution of KJ with soluble costabilizers (phosphate 1 ) reduces the decrease significantly or even avoids it. This demonstrates the superiority of the samples of the invention.
AND AN AROMATIC HALOGEN COMPOUND
The present invention relates to stabilized polyamide compositions.
Polymers are degraded easily when heated by oxidation, which leads to embrittlement of the material and to mechanical failure of the products produced therefrom.
Therefore particular chemical compounds are added which can delay the time of embrittlement with different activity. These so-called antioxidants are mostly built on the basis of phenyl derivatives, amine derivatives or phosphorous derivatives. Specific variants of antioxidants are employed with polyamides. One in particular active class of compounds, which does not have any activity with other polymers, are the so-called copper stabilizers.
These types of stabilizing systems are long known and are used widely for the preparation of polyamides, for examples for polyamide filaments which are used for the production of tyre cord and for polyamide extrusion molding parts for technical employment, in particular in the area of technical engineering (automobiles) and the electronic industry (switches, printed circuit boards).
These copper stabilizers usually consist of two components. As a first component, a compound such as copper halide or other copper salts are employed. In order to be effective as antioxidants, as second component a halogen compound must be added in a large surplus. Used in this respect are in particular potassium iodide and also potassium bromide. The employed molar ratio of copper to halogen is typically 1:5-15.
The recommended amount is generally 30 to 200 ppm copper and accordingly 150 to 3,000 ppm halogen.
These copper stabilizers do show somewhat satisfying results with polyamides.
However, these commonly employed copper stabilizers do show some severe drawbacks.
z Polyamides take up (conditioning) approximately 3% water. If the temperature changes water soluble components are extracted from the polyamide to the surface, which leads to the formation of scale. If copper halides, potassium halides or other soluble halides are employed these will be extracted to the surface and will form a hygroscopic scale which will react mostly acidic. Therefore the tracking resistance will decrease- Wlth electric components this may lead to failure. If eontact with metals is given the contact places will endure increased corrosion. Requirements of the electronic industry and the automobile industry regarding the question of tracking resistance are therefore difficult to fulfil.
At the same time these stabilizers are diffilcult to disperse in the polyamide. When preparing stabilized polyamides it is important to make sure that the employed stabilizers are finely powdered and can be admixed with the polyamide very homogeneously.
On problem associated therewith is usually the tendency of the usually employed components to agglomerate. The raw materials must therefore be ground very finely and must be protected against reagglomeration. The addition Itself is usually very difficult to control, therefore usually a master batch will be produced which will be added. Even then such a heterogeneous mixture of solid particles in a melt Is never optimal, compared with the hypothetical case that the stab~Iizer itself would be meltable and could be dispersed homogeneously under working conditions, as is the case with phenoic, amine and other antioxidants. The crystalline partiGes of the stabilezer salts effect the physical properties of the polyamides negative, even if they ors finely dispersed. This does not only result from possible inhamogeneity but also from the fact that fine particles aci as crystallisation nuGei which result in a higher crystallinity in polymers. This can lead to negative side effects. The impact strength can for example decrease by 20 to 30%, compared with the initial value of the non-stabilized polyamide.
Usual stabilizing compounds furthermore lead in polyamides after conditioning often to a bluish or greenish discoloration. Polyamldes reinforced with fiber glass may furthermore show a brown coloration due to the formation of copper oxide, resulting from high sheer stress given during processing. In particular negative are variations of the discoloration during the production cycles, which will make the use of the produced materials for non-colored or colored products difiticult. Therefore such polyamldes are usually employed after black coloration.
Usual stabilizing compounds are often added during the polymerization as aqueous solution in order to optimise the dispersion. One drawback is however that this addition may lead to formation of state of metallic copper or of copper oxide on the metal surface of the employed vessels and melt extruders. This may lead to variation in coloration and therefore to the discontinuation of the production. During spinning of filaments scale formation at the nozzle is often encountered which will lead to the discontinuation of the process.
In view of these drawbacks several improvements were proposed.
EP-A-39o2T! discloses a stabilized polyamide 4.6 composition- This particular high melting point polyamfde can be stabilized by addition of an unsoluble copper salt and a halogen substituted organic compound. These compositions are suitable for electric or electronic uses.
GB-A-1131933 and GB-A-1143826 disclose stabilized linear polyamides, stabilized with a mixture of a copper compound, soluble in the polyamide, and a specific halogen containing organic aliphatic compound with at most 7 carbon atoms. These organic compounds have however a high volatility. This may lead to undesired embrittlement of the material due to how out of the organic compound.
Starting from the above described problems associated with the prior alt it is therefore the object of the present invention to provide a stabilized polyamide composition which does not show the above named drawbacks, while simultaneously improving the long term temperature stability.
This object is solved in accordance with the present invention by the provision of a stabilized polyamide composition, characterized in that as stabilizer at least one copper salt and at least one organic halogen containing compound Is contained, selected among the group consisting of (a) aromatic compounds ; (b) aliphatic phosphates; (c) paraffins; or mixtures thereof, with the proviso that if the aromatic compound is a bromine containing styrene oligomer the polyamide is not polyamide 4.6.
Surprinsingly it was found that such stabilized polyamide compositions do show improved properties and an increased long term temperature stability.
Furthermore the present invention provides a process for the preparation of a stabilized polyamide composition, comprising the mixing of at least one polyamide, at least one copper Bait and at least one organic halogen containing compound selected among the group consisting of (a) aromatic compounds ; (b) aliphatic phosphates; (c) paraffins; or mixtures thereof, with the proviso that if the aromatic compound is a bromine containing styrene oligomer the polyamide is not polyamide 4.6.
Furthermore the present invention provides the use of at least one copper salt and at least one organic halogen containing compound, defined as given above, for the stabilization of polyamida compositions.
Prefered are each time compounds (a) andlor (b).
The at least one pvlyamide in accordance with the present Invention may be any polyamide. Polyamides are polymers showing recurrent carbon amide groups -CO-NH-in the polymer backbone. Polyamides are made from (a) amino cart~oxylic acids and their functional derivatives, for example lactames; or from (b) diamines and dlcarboxylic acids or their functional derivatives.
By varying the monomer units polyamldes are obtainable in a broad variety. In accordance with the present invention all polyamfdes may be stabilized, for example copolyamides or homopolyamides. Usable are furthermore block copolymers of polyamides and polyethers and other polymer modified polyamides. The most common types are polyamide 6 from e-caprolactam and polyamide BB from hexamethylene diamine and adipidic acid. Other important polyamides are potyamide 610, pofyamide 11, polyamide 12, PACM-12 , MPB-I, PPD-T and the aramides_ It is furthermore possible to use blends of polyamides with other polymers.
How ever, the stabilizing compounds may excert negative effects with respect to the blend components.
Therefore these most be chosen carefully.
In accordance with the present invention any copper salts may by used.
Preferred are salts of mono- or divalent copper with inorganic or organic acids. Examples of suitable copper salts are copper (I) salts, such as CuJ, CuCI, ar GuGN, copper (II) salts, such as CuCl2, CuBr2, Cu-acetate, Cu-sulfate, Cu-stearate, Cu-propionate, Cu-butyrate. Cu-lactate, Cu-benzoate or Cu-nitrate, as well as ammonium complexes of the above given salts.
Furthermore compounds such as Cu-acetylacetonate or Cu-EDTA may be employed.
It is furthermore possible to use mixtures of different copper salts. Optional Cu powder may be used. This reacts with poiyamlde melts under formation of copper compounds.
Preferred are Cu (I) halides and Cu-salts of organic acids, in particular preferred are CuJ
and Cu-acetate.
The amount of copper , used in the stabilized polyamlde compositions is not limited, as long as the mechanical properties of the polyamide are not affected detrimental. Usually the amount is between 10 and 1000 ppm copper, based on the total composition.
Preferably 20 to 700, in particular 50 to 150 ppm copper are employed.
As organic halogen containing compound of the invention any aromatic andlor any aliphatic phosphate andlor any paraftln may be employed. Preferred are aromatic bromine containing compounds, bromine containing aliphatic phosphates and chlorine or bromine containing paraffines. The molecular weight of the employed compounds of the invention is not limited. It should be selected so that the compount is not too volatile, the compound can be mixed easily and homogeneously with the polyamide and shows only minor migration tendency In the final composition. Preferred are further bromine containing aromatjc oltgomeric epoxy resins, in particular compounds on the basis of tetrabromobisphenol-a.
Examples of usable paraffins era halogenated, in particular fluorinated, chlorinated or brominated paraffins. Usable are furthermore soft as well as hard paraffins.
Preferred are compounds such as chloroparaffins (for example with an average formula of CzaH=aCl,s ), teflon waxes (for example with an average formula of CzoH~FZO) and Viton copolymers (copolymers of hexafluoroprapylene and vinylidene fluoride).
Examples of suitable compounds are-Tris-{neobromopentyl)phasphate (phosphate 1), dibromodfoxaphosphorinane derivatives and chlorine containing polyphosphonates and dekabr~omophenyl, dekabromophenylether, polydibromostyrene, tetrabromoblsphenol-A, chlorinated and brominated styrene oligomers, tetrabromobisphenol-A-derivatives, such as (EP-ollgomer 1) and BEB6000 (EP-oligomer 2), which structures are given below, and chlorinated dimethanidibenzo(a,e)cacloocten-derivatives. Preferred are tris-(dibromoneopentyi)phosphate and dekabromophenyl and polydibromostyrene. It is furthermore possible to use mixtures of organic halogen containing compounds.
The addition amount of the halogen containing organic compound is usually below 10 wt°!°_ Typically such amounts are added so that 50 to 30,000 ppm halogen are present, preferably 100 to 10,000 ppm, snare preferably 500 to 7 500 ppm, based on the total composition.
accordingly usually a ratio of copper to halogen In the stabilized polyamide compositions of from 1:1 to 1:3000 is obtained. Preferred is the area from 1.2 to 1:100, In particular the range from 1:5 to 1:15 (based on the molar ratio).
Higher addition amounts usually do not lead to an increase of the stabilization effect, poiyamides containing more than 5~° organic halogen containing compounds do have a significant lower stability. They show increased cleavage of polymer chains, which leads to premature embrittlement of the products and to strong discoloration.
Preferably the content of organic halogen containing compound is less than 3 wt%, in particular less than 1 wt%.
The above defined copper salts and organic halogen containing compounds w~l ~
be named stabilizer components in the following.
Polyamlde compositions in accordance with the present invention show improved long teen temperature stability, improved tracking resistance and lower discoloration. These advantages of the compositions of the present invention are deemed to be due to the synergistic effect of the organic halogen containing compounds, which must be added in minor amounts only.
The tracking resistance, which is determined as CTI-value is improved greatly with the use of the organic compounds. Accordingly the area of practice for the polyamide composi~ons in accordance with the invention is broadened to produces which are used in the electro or electronic industry.
Polyamides for electrical products should possess CTI-values of 600, at least however of 550. This value is reached with pure polyamide. The CTI-value is determined in accordance with DIN-IEC 112.
The polyamide compositions in accordance with the present invention further show, compared with usual copper/halogensalt-stabilizers, improved electrical strength.
The used organic compounds show, compared with halogen salts an improved dispersion ability in the polymer melt. Therefore a complicated homogenisation can be omitted. If at the same dme a copper salt such as copper stearate is employed, the stabilizer itself is meltable and therefore easy to disperse in the polyamide_ The stabilizing components are compatible with ail sorts of pofyamines.
Therefore blooming at the processing apparatuses (nozzles, extruders, molds) and the produced parts and filaments does not occur.
Furthermore the polyamide compositions in accordance with the present Invention do show only very limited tendency towards discoloration. In particular wit fiberglass reinforced polyamides with conventional copper stabilizers discolorations were sv strong that these compositions wefe only usable after black coloration. It is therefore surprising that this discoloration occurs with the polyamide compositions according to the present invention only to a minor extent, if at all. It is possible to obtain compositions colored with pigments without color deviations- Even TiOz colored compositions maintain the clear white color. This opens a new application field for colored polyamides in areas where improved long term thermal stability is required, so long only obtainabiy with common stabilizers having the drawback of strong discoloration.
The polysmide compositions in accordance with the present invention therefore have the advantage of fmprovef long term temperature stability while being at the same time colorable with pigments, without the danger that the usual own discolorations alter the pigment coloration.
For coloration of the polyamide composmons in accordance with the present invention all common pi~ments are suitable, such as titandloxld~, lead white, zinc white, lipone, antimony white, carbon black, iron black, mangan black, cobalt black, antimony black, lead chromate, mennige, zinc yellow, zinc green, cadmium red, cobalt blue, Berlin blue, ultramarine, mangan violet, cadmium yellow, schweinfurt green, molybdenum orange, molybdenum red, chromium orange and chromium red, iron oxide red, chromoxide green, strontium yellow, chromoxidr~ green, molybdenum blue, chalk, acker, umbra, green soil, terra dl sienna and graphite_ The poiyamide compositions in accordance with the present invention are furthermore excellent concerning theft stability regarding hydrolysis. They show improved long term stability under acidic and basic conditions, vis-a-vis salt solutions, glycol water mixtures and hot fats and oils and organic solvents. Accordingly, the usually recognised decrease of mechanical strength (impact strength, tensile strength) and the tendency towards embrittlement of the poiyamides is drastically reduced and the long term durability enhanced. Compared with usually employed stabilizers, such as phenolic or amine compounds or common copperfialogen salt-stabilizers, improved effects are obtained.
The polyamide compositions in accordance with the present inventJon can furthermore be combined without limitations with further additives, such as lubricants, plasticiters, crystallization accelerators and pigments without detrimentally effecting the desired stabilization effect. In some cases even the used additives are stabilized against thermal decomposition or discoloration in polyamides. Therefore, polyamides mixed with plasticizers, such as BBS, or with waxes, such as montanates, no longer show a high tendency to ageing, when employed in polyamide compositions In accordance with the present invanticn.
Poiyamldes containing glass bowls, fiber glass, mineral additives or other reinforcing agents furthermore show, compared with common stabilizers, a significantly improved long-term thermal ageing stability.
The polyamide compositions in accordance with the present invention may contain furthermore usual fillers and reinforcing agents. Examples of suitable fillers and relnforsing agents are glas materials In the form of fibers, ravings, beads or powders, oxidic materials, such as sflics, alumina or aluminum silicates as well as graphite or plastic fibers or whiskers.
The above described advantages of the polyamlde compositions of the pres~nt invention make it possible to use them for the preparation of fibers and for parts in the electric or electronic industry, mainly plug-in parts, plates (supports for electric r~~ntacts) and casing parts.
Furthermore, the stabilized polyamide compositions in accordance with the present invention were evaluated in order to deteimlne whether any further improvement of the discoloration tendency could be achieved. Surprisingly, it was found that a further reduction of the discoloration could be achieved by the addition of organic phosphites or inorganic phosphonates or inorganic hypophosphltes. These substances ara known as color stabilizers in polyamides. It was, however, also known that these color stabilizers could lead ofken to the formation of copper oxides with copper salts.
Therefore, a grey discoloration or brown/ black discolorations occurred. Therefore, it was surprising that the combination in accordance with the present inv~ntlon does not lead to any discoloration and that, furthermore, the blue discoloration, occurring sometimes after conditioning could be reduced by the addition of organic phosphites ar inorganic phosphonates or inorganic hypophophites. The slight discoloration occurring during this mixing can be cross dyed for the preparation of color stable polyamides, It was furthermore found that this addition furthermore retards the ageing of the polyamides during thermal storage. This effect is particularly significant with organic phosphates.
The employable organic phosphates are esters of the phosphoric acid.
Employable are aliphatic as well as aromatic or mixed esEers. Typical examples are, for example, dimethyl and diethyl phosphlte, trimethyl and methyl phosphate as well as the additives known in the plastic processing Industry. Typical examples are Tris(2,a-dl~t-butylphenyl)phosphite (Phosphate 20), Bis(2,4-di-t-butylpheny!)pentaerythritoldi-phosphate (Phosphate 21 ), Tetrakis(2,4-di-t-butylphenyl)4,4'-biphenylendiphosphonite (Phosphate 23), Dlstearylpentaerythritoldiphosphite, Diisoactylphosphite, Distearylphosphite, Triisodecylphosphlte, Triisooctylphosphite, Trilaurylphosphite, Tristearylphosphite, Tris(dipropylenglycol)phosphlte, Diphenylphosph~te, Trisnonylphenyfphosphite, Triphenylpho5phite, Trls(p-nonylphenyl)phosphite. These compounds are available under the tradenames Irgafos, Alkanox and Weston from the companies Ciba, Weston and The Great Lakes. Preferred are, in peritcular, Phosphate 20, Phosphate 21, Phosphate 22 and Phosphate 23.
Usable inorganic phosphonates are salts of the phosphonic acid. Employable as salt builders are alkali metals, earth alkali metals and ail other usual metals.
Preferred are, in particular, lithium, potassium, sodium, magnesium, calcium, strontium, barfum and aluminum, in particular preferred are sodium, potassium, magnesium and calcium. A
preferred phosphortate is disodium hydrogen phosphonate.
The usable inorganic hydrophosphltes are salts of the hypophosphortc add.
Concerning the salt building, it Is referred to the above metals listed in connection with the inorganic phosphanates. The sodium salt of the hypophosphoric acid is a preferred example of the employable hypophosphites_ The addition amount of the above given additives is between 0.005 and 1.0% (50 to 10,000 ppm), preferably from 0.05 to 0.2% (500 to 2000 ppm) and in particular preferably from 0.075 to 0.15% (750 to 1500 ppm). These amounts relate everytime to the total composition.
The organic phosphltes to be used are preferably mekable, processing stable and stable against extraction. This ensures that no phosphoric acid will be cleaved which may have disadvantageous effects for the total composition. The above given organic phosphltes, in particular the Phosphates 20, 21, 22 and 23, satisfy the requirements excellently.
Therefore, these compounds are particularly preferred.
It has, furthermore, been recognised during the preparation of the stabilized polyamide compositions in accordance with the present invention that the addition of the organic phosphate, the inorganic phosphonates and the inorganic hypophosphites should preferably occur only after the preparation of the basic composition stabilized with the stabilizing components.
If a stabilized polyamide composition in accordance with claim 1 is produced first and if the organic phosphate, the inorganic phosphonate or the inorganic hypaphosphite is added only thereafter during an additional step, no discoloration occurs. The above described procedure is in particular efPeciive with inorganic phosphonates.
The organic phosphite, the inorganic phosphonate or the inorganic hypophvsphite can be added as such or In the form of a masterbatch. Concerning the masterbatch technology it is referred to the previous disclosure in this respect, the same principles are valid here.
The production of the polyamide compositions is carried out usually by mixing at least one polyamide with at least one copper compound and at least one halogen containing compound, selected as defined in claim 1.
It is possible to mix the components using.common apparatuses, namely polyamide and stabilizing compounds are mixed with one another and are fused. It is preferred, however, to first fuse the polyamide and to mix in subsequently the stabilizing components. It is even more preferred to add the stabilizing compound in the form of a master batch to the molten polyamide. This simplifies in particular the metering of the stabilizing components.
Suitable mixing apparatuses are known to the person skilled in the art and comprise mixing rollers, discontinuous kneaders, continuous extruders and kneaders and static mixers. Preferred is the use of continuous extruders, single screw extruders as well as double screw extruders, which allow a good mixing. Usually the polyamide will be fused in the extruder, the stabilizing component can be metered in later through suitable openings. This process as well as the apparatuses for these purposes are known to the person skilled in the art.
It is furthermore possible to add the stabilizing components during the production of the polyamides, for example by adding them to the monomer mixture. This leads to a very good dispersion without any further mixing step which reduces the production costs and the production time.
If a master batch of the stabilizing components is used for the production of the polyamide compositions in accordance with the present invention, the master batch can be produced in discontinuous mixers which allow a very good homogenous mixing, for example a Buss-kneader. However, usually continuous mixers are used such as double screw extruders or ZSK-extruders. The matrix material ampioyed is usually the same polyamide which will b~ mixed later with the master batch It is, however, also possible to usa another polyamide or another polymer. The concentrakion of stabilizing components depends from the compatability of the matrix material and from the desired final concentration in the final blend and from good metering ability. Masterbatches with concentrations up to 50% can be obtained, for example from a mixture of CuJ
and polydibromostyrene (1:10).
In the following some preferred combinations of copper salts and organic halogen containing compounds are given.
Copper compound Organic halogen compound CuJ Tris-(tribromoneopentyl)phosphate CuJ 1,2,3-indioxaphosphorinane-5,5-bis(bromomethyl)-2-methoxy-2-oxide CuJ Polydibromostyrene CuJ Dekabromophenylether CuCl2 Tris-(tribromoneopentyl)phosphate Cu-acetate Tris-(tribromoneopentyl)phosphate Cu-acetate Tris-(tribromoneopentyl)phosphate Cu-acetate EP oligomer 2 CuJ EP oligomer 1 CuJ Dechlorane plus CuJ Chloroparaffin av. C20H24C118 CuJ Teflon wax av. C20H22F20 Cu (II) stearate Phosphate 1 The Ep oligomers in particular possess high temperature stability. Furthermore their combinations with copper compounds are cheap.
Polydibromostyrene and EP oligomer 1 are suitable for the preparation of highly concentrated masterbatches. Masterbatches up to 50% of these compounds can be prepared.
EP oligomer 2 can only be introduced up to 10%. Due to a reaction of the EP-end groups with amino groups in the polyamide a strong increase of the viscosity is encountered. This chemical reaction however has the advantage that the dispersion and bonding in the final product is increased.
12a In another aspect, the present invention provides use of at least one copper salt and at least one organic halogen containing compound for the stabilization of polyamides, wherein the organic halogen containing compound is selected among the group consisting of: (a) aromatic compounds; (b) aliphatic phosphates; and (c) paraffins; or mixtures thereof, with the proviso that, if the aromatic compound is a brominated styrene oligomer the polyamide is not polyamide 4.6, and with the proviso that the organic halogen containing compound is not an iodide containing compound.
In another aspect, the present invention provides a polyamide composition, characterized in that as stabilizer at least one copper salt and at least one organic halogen containing compound are contained, wherein the organic halogen containing compound is selected among the group consisting of: (a) aromatic compounds; (b) aliphatic phosphates; and (c) paraffins; or mixtures thereof, with the proviso that, if the aromatic compound is a brominated styrene oligomer the polyamide is not polyamide 4.6, and with the proviso that the organic halogen containing compound is not an iodide containing compound, wherein said copper salt is in an amount of 10 to 1,000 ppm, wherein said organic halogen is in an amount of 50 to 30,000 ppm, and wherein said paraffins comprise 7 or more carbon atoms.
In another aspect, the present invention provides a method for the preparation of a stabilized polyamide composition, characterized in that at least one polyamide, at least one copper salt and at least one organic halogen-containing compound, selected among the group consisting of: (a) aromatic compounds; (b) aliphatic phosphates; and (c) paraffins; or mixtures thereof are mixed with one another, with the proviso that, if the aromatic compound is a brominated styrene oligomer the polyamide is not polyamide 4.6, and with the proviso that the organic halogen containing compound is not an iodide containing compound, wherein said copper salt is in an amount of 10 to 1,000 ppm, wherein said organic halogen is in an amount of 50 to 30,000 ppm, and wherein said paraffins comprise 7 or more carbon atoms.
In another aspect, the present invention provides use of at least one copper salt and at least one organic halogen containing compound for the stabilization of polyamides, 12b herein the organic halogen containing compound is selected among the group consisting of: (a) aromatic compounds; (b)aliphatic phosphates; and (c) paraffins;
or mixtures thereof, with the proviso that, if the aromatic compound is a brominated styrene oligomer the polyamide is not polyamide 4.6, and with the proviso that the organic halogen containing compound is not an iodide containing compound, wherein said copper salt is in an amount of 10 to 1,000 ppm, wherein said organic halogen is in an amount of 50 to 30,000 ppm, and wheren said paraffins comprise 7 or more carbon atoms.
The following examples illustrate the invention.
The samples tested in the following examples have been prepared and tested as follows.
Preparation of samples Stabilizer mixtures and Ca-stearate as lubricant are mixed with polyamide granules and melted in an extruder. The mixture is homogenized in the extruder and extruded continiousfy Subsequently granules are formed. Cu concentration was always 100 ppm, halogen concentration 1000 ppm (0.1~) and Ca-stearate concentration 0.3%.
After drying the granules were formed into test: samples using an Infection molding apparatus for measuring impact strength (DIN 53453) and bending strength (DIN 53452).
Heat agoing DIN 53497 and DIN 53446 The previously prepared test samples were put in an heat oven at 130, 150 and 185°C
and were stored at these temperatures until measurements have fallen under 50%
of the initial values. The period until this value was taken as hatftime and is the value for the heat ageing stability of the polyamide. This value demonstrates the effect of the employed stabilizers. Since many polyartiides age very rapidly without stabilization (24h at ~ 50°C) a use of these materials without stabilization is often not possible.
Tracking resistance (CTI-values) Test samples werde produced of a size of 3x5 cm (3mm thickness; infection molding) and tested in accordance with DIN-IEC 112.
Color determination Discoloration of test samples was evaluated optically. In addition the color intensity was evaluated with the determination of the brightness (DIN 6174; DIN 5033, Part 1-7).
Example 1 Stabilization of PA 6 , heat ageing at 150°C. Compatision with other copper stabilizers, addition amount 100 ppm copper. 1000 ppm halogen. Measurement of Impact strength until value decreases to 50% of Initial value (half value measurement);
measurement of tracking resintance (CTl-value); color after molding and after conditioning, color determination (CIE Lab values; DIN 8174}.
Table 2 Type CompositionHalftime CTI-value DiscolorationDiscoloration (h) after after formation conditioning 1 ComparisonPA 6 24 600 colorless Colorless (natur) 2 ComparisonCuJ/KJ 1100 450 colorless Light green 3 ComparisonCu- 750 400 colorless Light blue acetate/KBr 4 ComparisonCu- 800 450 Yellow-ishBlue green stearate/KJ
Invention CuJ/PDBS 850 525 yellowish yellowish 6 Invention CuJ/DBDP 850 550 Yellowish Blue green E
7 Invention CuJ/ 1200 550 colorless Blue green Phosphat 8 Invention CuJI 900 550 yellowish Blue green Phosphate 9 I InventionCuJ/TBBA 900 550 colorless Blue green EP
oligomer Invention I Cu-acetate/800 525 colorless Light blue TBBA EP
oligomer 11 Invention Cu(II) 1100 500 beige ochre acetate!
phosphate 12 Invention CuClz/ 1000 550 beige ochre phosphate 13 Invention CuCI/ 900 550 beige Light blue phosphate 14 Invention CuBr / 900 600 colorless Light blue phosphate 15 Invention CuC03 800 600 colorless Light blue phosphate 16 Invention CuJ/ 950 550 brown Brown chloroparaffin 17 Invention CuBr/ I 900 600 beige Light brown dechlorane plus 18 Invention Cu- 850 600 beige Light brown stearate/
dechlorane plus Table 2 (coot.) after molding after conditioning Type DiscolorationBrightnesDiscolorationBrightnesGreen-red Blue-yellow L-value L-value a-value b-value 1 Colorless 68.2 Colorless 69.3 -3.2 -1.8 2 ~ Colorless 68.3 Light green66.2 -11.7 4.2 3 Colorless 69.1 Light blue 68.2 -7.8 -1.5 4 I Yellow-ish 67.5 Blue green 65.0 -7.7 2.9 5 Yellow-ish 68.8 Blue green 66.7 -9.6 -2.4 6 Yellow-ish 69.2 Blue green 68.7 -5.9 -3.2 7 Colorless 69.8 Blue green 69.2 -8.9 -1.8 8 Yellow-ish 67.3 Blue green 66.7 -5.6 6.9 i 9 Colorless68.8 Blue green68.3 -8.5 0.6 ~
Colorless69.2 Light ~ 68.4 -8.8 4.0 blue 11 Beige 61.78 Ocker 59.81 ~.5 4.6 12 Beige 63.47 Ocker 61.41 -4.4 2.6 ~
13 Colorless69.55 Light 67.08 -7.7 -2.1 blue .
14 i ColoHess 68.47 Light 57.71 -6.9 -2.4 blue Colorless68.09 Light 67.32 -7.2 -2.0 , blue 16 Brown 22.99 Brown 22.61 2.6 6.9 17 Beige 46.42 Light 43,80 0.8 4.2 brown 18 Beige 49.81 Light 47.36 -3.7 2.8 brown .. .,~a.a. ' p4~ ~ ~°~. ~] . Q °~.~~ EP-Oligomer 1 a~ ,, °~~ ..
EP-Oligomer 2 These results show that the polyamide compositions, stabilized in accordance with the invention do show slgnlflcantly improved tracking resistance and at the same time prolonged thermal stability. Discolorations are not detrimental for a later coloration of the samples of the invention.
Further experiments were carried out as above using 1000 ppm phcsphite or phosphate_ Samples and results are given in table 2a Table 2a Type Composition Halftimevalue DiscolorationDiscoloration (h) after after molding conditioning 19 InventionCuJI 1150 600 colorless Light blue phosphate phosphits (23) 20 Invention(CuJ/ 1100 600 Colorless Light blue Phosphate 1 ) in polyamide/
phosphite (20) 21 Invention(CuJ/ 1200 600 Colorless Light blue PDBS) in polyamide/
phosphite (21 ) 22 InventionCuJ/ 1100 550 Colorless Light blue PDBS) in polyamide/
disodium hydrogen phosphate 23 InventionCu(II) 900 600 colorless Light blue stearate/
phosphate / phosphite (21 ) After molding after conditioning Type DiscoloratiBrightnessDiscoloratiBrightnessGree-redBlue-on L-value on L-value a-value yellow j b-value 19 colorless70.07 Light 6B.21 -7.7 -2.B
blue 20 Colorless73.68 Light 71 _78 -3.3 blue -8.2 21 Colorless69.96 Light 67.95 -2.7 blue ! -7.4 I
22 Colorless68,89 Light 66.21 -1.0 blue '-5.9 23 ' 68.32 66.09 -1.8 colorless ~ Llght - I -6,3 blue ~
Example 2 Stabilization of PA 66 (natur), heat ageing test at 165'C, Composltlons and measurements as In example 1 Additional experiments with 1000 ppm phosphite or phosphonate were done also.
Table 3 Type ComposttioHatftirneCT1-valueDiscoloratioDiscoloratio (h) n n after n after formationconditlonin ComparlsioPA 66 12 600 Colorlesscolorless n (natur) ComparisioCuJ/KJ 140 450 ColorlessLight ~ green n CompansioCu- 90 400 ColorlessLight ~ acetate/KBr blue ComparisioCu- 90 450 YellowishBlue green n stearate/KJ
t Invention S25 YellowishBlue CuJ1 green PDBS
~ 130 ' inventionGuJI 130 550 Yellowish Blue green DBDPE
~
InventionCuJI ~ 480 550 Colorless Blue green Phosphatl InventionCuCI 150 475 bei a brown ~ g z phosphate ' ( InventionCuGl/ 190 475 Colorises Light blue Phosphat 1 s InventionCu-acatatel350 ! 475 ~ beige I brown Phosphat 1 ~
InventionCu-acetate/120 525 colorless Light ~ blue ~
l InventionCuJI 150 550 colorless Blue green EP- l Oiigomer InventionCuJI 330 550 beige ocker I
dechlorane l ~
plus InventionCuJI 370 550 brown brown chloro paraffinI
~ ~~
InventionGuJI 450 BOO Colorless Light blue phosphate l 1l ~ l phosphite (20) l Invention(CuJ/ ~ 450 600 Colorless Light blue I
~ ~
PDBS) in polyamide/
phosphate~ ;
I (20) ~ t ' Also these samples in accorbance with the present invention do show improved tracking resistance and thermal stability so that the application of these samples in the electronic area is possible-Example 3 Stabilization of PA 66, reinforced with 30°!° fiberglass (GF30), experiments as in example 2. Halftime values relate to bending strength. Addition amount of phosphate or phosphate 1000ppm.
Table 4 Type CompositionHalftime CTI- DiscolorationDiscoloration (h) value after moldingafter conditioning Comp. PA 66 GF30 120 550 Colorless Colorless Comp. CuJ/KJ 1200 450 Yellowish Blue green Comp. Cu-acetate/900 400 brown Brown KBr InventionCuJ/PDBS 900 525 yellowish Yellow green InventionCuJ/ 1800 525 Colorless Yellowish phosphate InventionCuJI EP 1300 525 Colorless Light green oligomer InventionCuJ/ 1300 550 Colorless Light green Phosphate phosphate (2) invention(CuJIPDBS) 1400 550 Colorless Light green in polyamide/
phosphate (21) Samples in accordance with the invention do show, as in previous examples CTI-values allowing the use in electric parts.
Example 4 Stabilization of PA 66 (natur) and PA 66 GF30 with copper stabilizers, addition of 100 ppm copper, 1000 ppm halogen, 1000 ppm phosphate or phosphonate. Measurement of initial impact strengths: Izod with PA 66 (natur) and Charpy (not notched) with PA 66 GF30.
Table 5 Type Composition Halftime at Impact strength 165C (h) (kJ/m2) Comp. PA 66 GF30 120 45 (Charily) Comp. CuJ/KJ 1200 35 (Charily) Invention CuJ/ Phosphate 1800 41 (Charily) Comp. PA 66 (natur) 12 5.5 (Izod notched) Comp. CuJ/KJ 140 4.0 (izod notched) Invention CuJ/ Phosphate 480 5.5 (lzod notched) Invention CuJ/ Phosphate 1400 35 (Charily) j 1/ j phosphite (20) in PA
Invention (CuJ/ PDBS) in 1200 45 (Charily) Polyamide 66/
phosphite (21 ) Example 5 Extraction stability of PA 6 and PA 66 GF30 with water and ethanol. Evaluation in accordance with DIN 53738. Stabilization with 100 ppm copper and 1000 ppm halogen, 1000 ppm phosphite or phosphonate. Determination of extract composition after 16h reflux.
Table 6 Type Composition Amount of Composition of extract (%) extract Invention/Vl/aterPA 66 natur CuJ/ 0.3 No copper or halogen Phosphate 1 or P
InventionNVaterCuJ/ Phosphate 0.3 No copper or halogen phosphite (21 or P
) PA66 natur InventionNVaterCuJ/ Phosphate 0.2 No copper or halogen PA66 GF30 or P
Invention/WaterCuJ/ Phosphate 0.2 No copper or halogen Phosphite (21 or P
) PA 66 Invention/EthanolCuJ/ Phosphate I 0.6 No copper or halogen PA6 natur or P
Invention/EthanolCuJ/ Phosphate 0.6 No copper or halogen phosphite (20) or P
natur Invention/EthanolCuJ/ PDBS /PA6 0.5 No copper or halogen GF30 or P
Invention/EthanolCuJ/ Phosphate 0.5 No copper or halogen phosphite (20)/ or P
Example 6 Hydrolysis stability of PA 66 GF30, decrease of mechanical properties (hardness and bending strength) after storage In 100% glycol, 48h at 135°C. 150 ppm copper, 1500 ppm halogen, 1000 ppm phosphite or phosphonate.
Table 7 Type compositionCTI- Ball- Bending Ball- Bending value pressurestrength pressure strength hardness hardness (aS) (aS) Comp. CuJ/KJ/ 450 141 276 91 130 KBr InventionCuJ/ ~ 525 140 280 94 134 Phosphate i Invention(CuJ/ 525 139 278 92 ~ 132 PDBS) in polymide/
Phosphite (21 ) InventionCuJ/ 525 140 278 95 135 Phosphate Phosphite (20) i (aS): after storage, ball-pressure hardness measured in accordance with ISO
2039/1, bending strength measured in accordance with DIN 53456 Samples in accordance with the present invention and comparative examples show, that the polyamide compositions of the present invention show improved long term temperature stability and improved maximum temperature durability and improved tracking resistance. Also the tendency towards discoloration is reduced, compared with conventional polyamide compositions. Initial impact strength is affected by use of stabilizers in form of salts (CuJ/KJ). Substitution of KJ with soluble costabilizers (phosphate 1 ) reduces the decrease significantly or even avoids it. This demonstrates the superiority of the samples of the invention.
Claims (18)
1. A stabilized polyamide composition, characterized in that as stabilizer at least one copper salt and at least one organic halogen containing compound are contained, wherein the organic halogen containing compound is selected among the group consisting of:
(a) aromatic compounds;
(b) aliphatic phosphates; and (c) paraffins;
or mixtures thereof, with the proviso that, if the aromatic compound is a brominated styrene oligomer the polyamide is not polyamide 4.6, and with the proviso that the organic halogen containing compound is not an iodide containing compound, wherein said copper salt is in an amount of 10 to 1,000 ppm, wherein said organic halogen is in an amount of 50 to 30,000 ppm, and wherein said paraffins comprise 8 or more carbon atoms.
(a) aromatic compounds;
(b) aliphatic phosphates; and (c) paraffins;
or mixtures thereof, with the proviso that, if the aromatic compound is a brominated styrene oligomer the polyamide is not polyamide 4.6, and with the proviso that the organic halogen containing compound is not an iodide containing compound, wherein said copper salt is in an amount of 10 to 1,000 ppm, wherein said organic halogen is in an amount of 50 to 30,000 ppm, and wherein said paraffins comprise 8 or more carbon atoms.
2. The stabilized polyamide composition in accordance with claim 1, characterized in that the copper salt is selected among copper salts of organic and inorganic acids.
3. The stabilized polyamide composition in accordance with claim 1 or 2, characterized in that the copper salt is copper (I) halide.
4. The stabilized polyamide composition in accordance with any one of claims 1 to 3, characterized in that the aliphatic phosphate is selected among tris-(tribomoneopentyl)phosphate, dibrome-dioxyphosphorinan derivatives and chlorine containing polyphosphonates.
5. The stabilized polyamide composition in accordance with any one of claims 1 to 3, characterized in that the aromatic compound is selected among dekabromphenyl, dekabromphenylether, chlorinated dimethanenodibenzo(a,e)-cyclooctenes, tetrabromo-bisphenol A, chlorinated or brominated styrene oligomers, tetrabromo-bisphenol A
derivatives and polydibromostyrene.
derivatives and polydibromostyrene.
6. The stabilized polyamide composition in accordance with any one of claims 1 to 3, characterized in that the paraffin is chloroparaffin or bromoparaffin.
7. A method for the preparation of a stabilized polyamide composition, characterized in that at least one polyamide, at least one copper salt and at least one organic halogen-containing compound, selected among the group consisting of:
(a) aromatic compounds;
(b) aliphatic phosphates; and (c) paraffins;
or mixtures thereof are mixed with one another, with the proviso that, if the aromatic compound is a brominated styrene oligomer the polyamide is not polyamide 4.6, and with the proviso that the organic halogen containing compound is not an iodide containing compound, wherein said copper salt is in an amount of 10 to 1,000 ppm, wherein said organic halogen is in an amount of 50 to 30,000 ppm, and wherein said paraffins comprise 8 or more carbon atoms.
(a) aromatic compounds;
(b) aliphatic phosphates; and (c) paraffins;
or mixtures thereof are mixed with one another, with the proviso that, if the aromatic compound is a brominated styrene oligomer the polyamide is not polyamide 4.6, and with the proviso that the organic halogen containing compound is not an iodide containing compound, wherein said copper salt is in an amount of 10 to 1,000 ppm, wherein said organic halogen is in an amount of 50 to 30,000 ppm, and wherein said paraffins comprise 8 or more carbon atoms.
8. The method in accordance with claim 7, characterized in that at least one copper salt and at least one organic halogen containing compound are added in the form of a masterbatch.
9. Use of at least one copper salt and at least one organic halogen containing compound for the stabilization of polyamides, wherein the organic halogen containing compound is selected among the group consisting of:
(a) aromatic compounds;
(b) aliphatic phosphates; and (c) paraffins;
or mixtures thereof, with the proviso that, if the aromatic compound is a brominated styrene oligomer the polyamide is not polyamide 4.6, and with the proviso that the organic halogen containing compound is not an iodide containing compound, wherein said copper salt is in an amount of 10 to 1,000 ppm, wherein said organic halogen is in an amount of 50 to 30,000 ppm, and wheren said paraffins comprise 8 or more carbon atoms.
(a) aromatic compounds;
(b) aliphatic phosphates; and (c) paraffins;
or mixtures thereof, with the proviso that, if the aromatic compound is a brominated styrene oligomer the polyamide is not polyamide 4.6, and with the proviso that the organic halogen containing compound is not an iodide containing compound, wherein said copper salt is in an amount of 10 to 1,000 ppm, wherein said organic halogen is in an amount of 50 to 30,000 ppm, and wheren said paraffins comprise 8 or more carbon atoms.
10. The stabilized polyamide composition in accordance with any one of claims 1 to 6, characterized in that further at least one organic phosphite, inorganic phosphonate or inorganic hypophosphite is contained.
11. The method for the preparation of a stabilized polyamide composition in accordance with claim 7 or 8, characterized in that in a further processing step at least one organic phosphite, inorganic phosphonate or inorganic hypophosphite is added to the mixture obtained in accordance with claim 7 or 8.
12. The composition according to claim 1, wherein the molar ratio of copper to halogen is 1:5 to 1:15.
13. The composition according to claim 1, wherein said copper salt is in an amount of 30 to 200 ppm, and wherein said organic halogen is in an amount of 150 to 3,000 ppm.
14. The method according to claim 7, wherein the molar ratio of copper to halogen is 1:5 to 1:15.
15. The method according to claim 7, wherein said copper salt is in an amount of 30 to 200 ppm, and wherein said organic halogen is in an amount of 150 to 3,000 ppm.
16. The stabilized polyamide composition according to claim 1, wherein the polyamide is selected from the group consisting of polyamide 6 from .epsilon.-caprolactum, polyamide 66 from hexamethylene diamine and adipidic acid, polyamide 610, polyamide 11, polyamide 12, PACM-12, MPB-I, PPD-T, and aramides.
17. The method according to claim 7, wherein the polyamide is selected from the group consisting of polyamide 6 from .epsilon.-caprolactum, polyamide 66 from hexamethylene diamine and adipidic acid, polyamide 610, polyamide 11, polyamide 12, PACM-12, MPB-I, PPD-T, and aramides.
18. The use according to claim 9, wherein the polyamide is selected from the group consisting of polyamide 6 from .epsilon.-caprolactum, polyamide 66 from hexamethylene diamine and adipidic acid, polyamide 610, polyamide 11, polyamide 12, PACM-12, MPB-I, PPD-T, and aramides.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19847626A DE19847626B4 (en) | 1998-10-15 | 1998-10-15 | Polyamide composition stabilized with copper salt and aliphatic halogenated phosphate |
| DE19847626.4 | 1998-10-15 | ||
| PCT/EP1999/007848 WO2000022036A1 (en) | 1998-10-15 | 1999-10-15 | Polyamide composition stabilized with copper salt and an aromatic halogen compound |
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| CA2347260A1 CA2347260A1 (en) | 2000-04-20 |
| CA2347260C true CA2347260C (en) | 2007-05-01 |
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| CA002347260A Expired - Fee Related CA2347260C (en) | 1998-10-15 | 1999-10-15 | Polyamide composition stabilized with copper salt and an aromatic halogen compound |
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| EP (1) | EP1121389A1 (en) |
| JP (1) | JP3647026B2 (en) |
| KR (1) | KR100447504B1 (en) |
| CN (1) | CN1159370C (en) |
| AU (1) | AU6203499A (en) |
| CA (1) | CA2347260C (en) |
| CZ (1) | CZ20011355A3 (en) |
| DE (1) | DE19847626B4 (en) |
| HU (1) | HUP0104775A3 (en) |
| PL (1) | PL200411B1 (en) |
| RU (1) | RU2207355C2 (en) |
| WO (1) | WO2000022036A1 (en) |
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| CN101421339B (en) * | 2006-04-11 | 2012-04-11 | 旭化成化学株式会社 | Method for producing polyamide masterbatch |
| DE102010051310A1 (en) | 2010-11-16 | 2012-05-16 | Thüringisches Institut für Textil- und Kunststoff-Forschung e.V. | Process for the preparation of polyamide compositions having improved thermo-oxidative, antibacterial, light or energy-active properties |
| CN102134392B (en) * | 2011-04-25 | 2012-07-04 | 上海梵和聚合材料有限公司 | Inflaming retarding PA66 composite material with high glowing filament temperature and process thereof |
| CN103010562B (en) * | 2013-01-10 | 2015-04-15 | 厦门新旺新材料科技有限公司 | Color-changed protection bag used under high-temperature environment |
| CN110177832A (en) * | 2016-10-17 | 2019-08-27 | L.布吕格曼两合公司 | The preparation method of the polyamide material of long-time service with improvement |
| EP3498788B1 (en) | 2017-12-18 | 2023-05-03 | Agfa-Gevaert Nv | Solder mask inkjet inks for manufacturing printed circuit boards |
| CN113661214A (en) | 2019-04-01 | 2021-11-16 | 奥升德功能材料运营有限公司 | Non-halogenated flame retardant polyamide composition |
| WO2021048156A1 (en) | 2019-09-11 | 2021-03-18 | Clariant International Ltd | Polymer composition comprising heat stabilizer and use thereof |
| WO2021048157A1 (en) | 2019-09-11 | 2021-03-18 | Clariant International Ltd | Polymer composition comprising heat stabilizer and use thereof |
| US20210277203A1 (en) | 2020-03-04 | 2021-09-09 | Ascend Performance Materials Operations Llc | Antimicrobial/antiviral plastics and molded products |
| US20230088990A1 (en) | 2021-09-16 | 2023-03-23 | Ascend Performance Materials Operations Llc | Antimicrobial/antiviral conveyor belt |
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| CH461090A (en) * | 1964-07-15 | 1968-08-15 | Schweizerische Viscose | Process for stabilizing poly (a-aminocarboxylic acids) |
| GB1143826A (en) * | 1968-10-28 | |||
| CA1338392C (en) * | 1987-04-20 | 1996-06-11 | Mitsui Chemicals, Incorporated | Fire-retardant polyamide composition having good heat resistance |
| CA2013049A1 (en) * | 1989-03-28 | 1990-09-28 | Pieter Gijsman | Polyamide 4.6 composition |
| TW210368B (en) * | 1992-02-03 | 1993-08-01 | Schweizerische Viscose | |
| DE19519820A1 (en) * | 1995-05-31 | 1996-12-05 | Bayer Ag | Thermostable, weather-resistant polyamide molding compounds |
-
1998
- 1998-10-15 DE DE19847626A patent/DE19847626B4/en not_active Expired - Fee Related
-
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- 1999-10-15 PL PL347330A patent/PL200411B1/en not_active IP Right Cessation
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| CN1326482A (en) | 2001-12-12 |
| AU6203499A (en) | 2000-05-01 |
| JP2003518142A (en) | 2003-06-03 |
| CZ20011355A3 (en) | 2001-11-14 |
| PL347330A1 (en) | 2002-03-25 |
| CA2347260A1 (en) | 2000-04-20 |
| HUP0104775A2 (en) | 2002-04-29 |
| KR20010090792A (en) | 2001-10-19 |
| DE19847626B4 (en) | 2004-08-19 |
| WO2000022036A1 (en) | 2000-04-20 |
| RU2207355C2 (en) | 2003-06-27 |
| HUP0104775A3 (en) | 2004-05-28 |
| DE19847626A1 (en) | 2000-04-20 |
| JP3647026B2 (en) | 2005-05-11 |
| CN1159370C (en) | 2004-07-28 |
| KR100447504B1 (en) | 2004-09-07 |
| PL200411B1 (en) | 2009-01-30 |
| EP1121389A1 (en) | 2001-08-08 |
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