NL8001685A - STABILIZED POLYCARBONATE MATERIAL WITH STABLE COLOR AGAINST THERMAL OXIDATION, AND METHOD FOR PREPARING THIS MATERIAL. - Google Patents

Description

*> 1

S 2348-1022 Le / nb P & C

Polycarbonate material of stable color, stabilized against thermal oxidation, as well as a process for preparing this material.

The invention relates to a polycarbonate-containing material and to a method for preparing it. More particularly, the invention relates to a heat oxidation stabilized polycarbonate material of stable color, which material contains an effective amount of a stabilizing agent selected from cyclic phosphonites and mixtures of cyclic phosphonites and cyclic ethers, as well as a process for preparing such a material.

Many polycarbonate materials are known which are suitable for forming objects, such as films, sheets, fibers and other shaped objects. These materials are generally thermoplastic and find particular use in the production of molded articles by known and conventional molding methods, such as injection molding, compression molding, foam molding, blow molding and extrusion. Due to the complicated shape of many parts or objects to be molded, as well as for the formation of thin walled articles, the application in this field of technology requires high molding temperatures for the polycarbonates used to completely fill the mold cavity and a satisfactorily formed provide an object, despite their complicated structure (shape).

However, because of the need to use high temperatures in the manufacture of complex structures, for which these materials are often desired, the polycarbonate materials so processed tend to undergo oxidative degradation and color development. In view of these inherent drawbacks of polycarbonates, much research has been conducted to overcome these drawbacks.

For example, U.S. Patent 3,809,676 describes a thermally stable polycarbonate material of stable color, which consists of a mixture of a halogen-containing, flame-retardant aromatic polycarbonate and a small amount, generally about 0.05-2.0 wt%, of A barium, cadmium or cerium salt of an aliphatic acid with up to 16 carbon atoms or barium or cadmium carbonate mixed with a phosphonite or a phosphienite, the latter phosphorus-containing materials having the formula (1) and (2), respectively.

Other polycarbonate stabilized against thermal oxidation is described in U.S. Pat. No. 3,859,248; according to this US patent, a phosphorus dihalide is directly incorporated into the polycarbonate and the polycarbonate, which contains the phosphorus compound, further mixes with an epoxy compound which may be an epoxidized cycloaliphatic material. Furthermore, polycarbonate materials stabilized against thermal oxidation are described in U.S. Pat. No. 3,766,139, according to which U.S. Pat. No. 5, directly includes a phosphorus dihalide in the polycarbonate.

Additional additives suitable for stabilizing polycarbonates from heat and discoloration include triorganophosphites, such as described in U.S. Patent 3,305,520, and a phosphite and an epoxy compound for stabilizing aromatic polycarbonates, as described in U.S. Patent 3,729,440 ; U.S. Patent 3,839,247 describes a water-clear polycarbonate material containing an aromatic or an aliphatic epoxy compound as a stabilizing agent. Aromatic polycarbonates stabilized against thermal oxidation and hydrolysis are described in U.S. Pat. No. 4,066,611; According to this US patent, the polycarbonate is mixed with a cyclic diphosphite or a combination of a cyclic diphosphite and an epoxide or a silane.

From the above, it appears that polycarbonate materials are available that exhibit improved properties in terms of thermal oxidation stability and color stability, and that different types of phosphorus compounds are used, optionally in combination with other materials, to impart these properties. However, while the above known polycarbonate materials are suitable and commercially acceptable, they still exhibit certain drawbacks: often, these materials are somehow ineffective in their resistance to thermal oxidation or color development. In other words, the known materials may be satisfactory in some respect to some of these properties, such as eg thermal breakdown, but fall short in other properties, such as color stability. Therefore, there is a need for a wider choice of polycarbonate materials suitable for technical applications such as, for example, object molding. In addition, this need also extends to polycarbonate materials that exhibit even further improved thermal stability and color stability properties.

As can be seen from the above patents, a variety of phosphorus-containing compounds, epoxy compounds and halogen compounds have been used to obtain polycarbonate materials that are stabilized against thermal oxidation and have a stable color. However, there is a need for a wider variety of 8001685

* I

Materials which exhibit even further improved properties in these respects, while likewise there is a need for further and other phosphorus-containing compounds to achieve the desired results. The invention addresses these needs by using cyclic phosphonites, eg several of the. cyclic phosphonites described in U.S. Pat. Nos. 3,264,324 and 3,270,092.

The present invention provides a stable color thermal stabilized material; this material contains a mixture of polycarbonate and an effective amount of a stabilizing agent selected from cyclic phosphonites of the formula (3) of the formula sheet (a), wherein R represents an alkyl group, haloalkyl growth group, aryl group, halaryl group, alkaryl group or halogenated alkaryl group; cyclic phosphonites of the formula (4) of the formula sheet (b), wherein R has the definition given above and R 'is an ethylidene group, a propylidene group, a 2,2-15 dimethylpropylidene group or a group of the formula (5) of the formula sheet represent and mixtures of these cyclic phosphonites and cyclic ethers. Although at least an effective amount of a stabilizing agent should be present in a material of the invention, such an effective amount is generally less than about 1.0 wt. % 20 and more generally about 0.02 - 2.0 wt. %, based on the total composition. The advantageous properties, in particular regarding color stability, imparted to a polycarbonate material by a stabilizing material as mentioned above are surprising and unexpected: the above stabilizing materials are more effective at stabilizing the color at equal phosphorus levels than the above-mentioned known phosphorus-containing stabilizers.

Examples of cyclic phosphonites of the formula (3) of the formula sheet (a) which can be used according to the invention are: 3,9-dialkyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro- [ 5.5] undecans wherein the alkyl group may be methyl, ethyl, propyl, butyl, pentyl, such as 3,9-dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro [5,5] undecans, 3,9-di-propyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro- [5,5] undecans ed? 3,9-dihaloalkyl-2,4,3,10-tetraoxa-3,9-diphosphaspiro [5,5] undecans in which the haloalkyl group may be halomethyl, haloethyl, halopropyl, halobutyl, halopentyl, etc., such as 3,9-dichloroethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro- [5,5] undecans, 3,9-dibromopropyl-2,4,8,10-tetraoxa-3,9-diphosphasprio- [ 5.5] undecans, etc .; 3,9-aryl-2,4,8,10-tetraoxa-3,9-diphosphaspiro- [5.5] undecans and 3,9-haloary1-2,4,8,10-tetraoxa-3,9-diphosphaspiro- [ 5.5] undecans, such as 3,9-dipheny1-2,4,8,10-tetraoxa-3,9-diphosphaspiro-8 Π n 1 R Η n - 4 - [5.5] undecane and 3,9-di-4 ' -chlorophenyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro- [5.5] undecane ed; 3,9-alkaryl-2,4,8,10-tetraoxa-3,9-diphosphaspiro [5,5] undecanes and halogenated compounds thereof such as, for example, 3,9-di-21methylphenyl-2,4 , 8,10-tetraoxa-3,9-diphosphaspira- [5,5] undecane, 3,9-di-4'-raethylphenyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro- [5 , 5] undecane, 3,9-di-3'-methylphenyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro [5,5] undecane and halogenated forms of these compounds, etc. A particularly suitable compound of this type is 3,9-diphenyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro- [5.5] undecane.

Examples of cyclic phosphonites of the formula (4) of the formula sheet (b) which can be used according to the invention are: 2-methyl-1,3,2-dioxaphospholane; 2-phenyl-1,3,2-dioxaphosphorinan; 2-butyl-5,5-diethyl-1,3,2-dioxaphosphorinan; 2- (p-tolyl) -4,4,5-trimethyl-1,3,2-dioxaphospholane; 2-hexyl-5-phenyl-1,3,2-dioxaphosphorinan; 2-cyclopentyl-4,5-dimethyl-1,3,3-dioxophospholane; 2-phenyl-4,5-dimethyl-1,3,3,2-dioxaphospholane; 2-cyclohexyl-1,3,2-dioxaphosphorinan; 2- (p-tolyl) -5-ethyl-5-methyl-1,3,2-dioxaphospholane; 2- (o-xylyl) 4,5,6-trimethyl-1,3,2-dioxaphospholane; 2-phenyl-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane; 2-phenyl-4,6-diphenyl-1,3,2-dioxaphosphorinan; 2-phenyl-5,5-dimethyl-1,3,3,2-dioxaphosphorinane, and 2-phenyl-4,5-benzo-1,3,2-dioxaphospholane.

In addition to the above cyclic phosphonite esters, compounds such as 2-propyl-4- (4-methoxybutyl) -5-methyl-1,3,2-dioxaphospholane, 2-phenyl-5-ethoxy-1,3,2-dioxaphosphorinane may also be used. , 2-cyclohexyl-5-phenoxy-1,2,3-dioxaphosphorinan, and 2- (p-tolyl) -5-methoxy-1,2,3-dioxaphosphorinan. Particularly suitable compounds of this type are: 2-phenyl-5,5-dimethyl-1,3,3,2-dioxaphosphorinane, and 2-phenyl-4,5-benzo-1,3,2-dioxaphospholane.

According to the invention, mixtures of two or more of the above-mentioned cyclic phosphonites can be used, wherein the total amount of cyclic phosphonite in the material is preferably not more than about 1 wt. %. Although the phosphonites may be present in the material in an amount of more than 1% without any adverse effect, the thermal oxidation stabilization and color stability 8001685 ¢ - Jr - 5 - are generally not improved by the presence of more than 1% of stabilizing material.

In addition to a cyclic phosphonite or a mixture of cyclic phosphonites, it is also possible to use a combination of a cyclic phosphonite and a cyclic ether, eg the epoxides mentioned in the above-mentioned U.S. Pat. No. 3,859,248. In these mixtures, the total amount of phosphonite does not exceed the above amounts and the cyclic ether is present in an amount up to about twice the amount of phosphonite used.

Any of the known polycarbonates can be used in the present materials, namely homopolymeric and copolymeric polycarbonates.

These materials can be prepared by any of the previously known methods. The polycarbonates are generally prepared from divalent phenols and a carbonate precursor, the reaction generally being conducted in the presence of an acid acceptor as well as a molecular weight regulator.

Examples of divalent phenols which can be used to prepare a polycarbonate which can be suitably combined with a stabilizing agent of the invention into a material of the invention are bisphenols, such as bis (4-hydroxyphenyl) methane, 2,2-bis ( 4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 4,4-bis (4-hydroxyphenyl) heptane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2.2-bis (4-hydroxy-3,5-dibromophenyl) propane, etc .; divalent phenol ethers such as bis (4-hydroxyphenyl) ether, bis (3,5-dichloro-4-hydroxyphenyl) ether, etc .; Dihydroxydiphenols such as p, p1-dihydroxyphenyl, 3,3, -dichloro-4,4'-dihydroxy-diphenyl, etc .; dihydroxyarylsulfones such as bis (4-hydroxyphenyl) sulfone, bis- (3,5-dimethyl-4-hydroxyphenyl) sulfone, etc., dihydroxybenzenes, resorcinol, hydroquinone, dihydroxybenzenes substituted by halogen and alkyl such as 1,4-dihydroxy-2-chlorobenzenes, 1 , 4-dihydroxy-2,5-dichlorobenzenes, 1,4-30 dihydroxy-3-methylbenzenes, etc .; and dihydroxydiphenyl sulfoxides such as bis- (4-hydroxyphenyl) sulfoxide, bis- (3,5-dibromo-4-hydroxyphenyl) sulfoxide, etc.

A variety of other divalent phenols are further available to provide carbonate polymers, such as the compounds disclosed in U.S. Patents 2,999,835, 3,028,365, and 3,153,008.

It is also possible to use two or more different bivalent phenols or a copolymer of bivalent phenol with glycol or with a polyester with terminal hydroxy or acid groups or with a dibasic acid to prepare a polycarbonate which is in a material - 6 can be used according to the invention. In this case, a carbonate copolymer is obtained instead of a homopolymer. Homopolymeric polycarbonates that are particularly suitable in the materials of the invention are bisphenol A polycarbonates, 3,3 ', 5,5'-tetramethyl bisphenol A polycarbonates 5 and 1,1- (4-hydroxyphenyl) -2 , 2-dichloroethylene polycarbonates. A particularly suitable copolymer polycarbonate is the reaction product of 3,3'-bis (4-hydroxyphenyl) pentane and bisphenol-A. A particularly suitable polycarbonate is the reaction product of 3,3'-bis (4-hydroxyphenyl) pentane, bisphenol-A and dimethyl terephthalate.

The carbonate precursor can be a carbonyl halide or a bishalogen formate. Examples of carbonyl halides to be used are carbonyl chloride, carbonyl bromide and mixtures thereof. Suitable bis-halo formates are the bishalogen formates of divalent phenols (bischloroformate of hydroquinone, etc.) or glycols (bishalogen formates of ethylene glycol, neopentyl glycol, polyethylene glycol, etc.). Carbonyl chloride (also called phosgene) is preferred as the carbonate product, although other carbonate precursors can also be used.

As mentioned above, the reaction can be carried out in the presence of an acid acceptor, which can be an organic or inorganic compound. Examples of suitable organic acid acceptors are tertiary amines, e.g. pyridine, thriethylamine, dimethylaniline, tri-butylamine, etc. The inorganic acid acceptors include alkali metal or alkaline earth metal hydroxides, carbonates, bicarbonates and phosphates.

Examples of molecular weight regulators which can also be used to prepare the polycarbonate resins are phenol, cyclohexanol, methanol, para-tert-butylphenol, para-bromophenol, etc. Preferably phenol is used or para-tert-butylphenol as molecular weight regulator.

The polycarbonate used in the materials of the invention can be linear or branched. The branched polycarbonates contain a small amount of a branching component which generally contains at least 3 ester-forming groups. It is noted that the branching component can provide branching in the alkylene portion or in the arylene portion of the polycarbonate or be a hybrid. Examples of branching agents are tri- and tetracarboxylic acids such as trimesinic acid, pyromellitic acid and the lower alkyl esters and anydrides thereof, etc. Furthermore, the branching components can also be polyols, e.g. tetrols, such as pentaerythritol; triplets, such as trimethylolpropane; and dihydroxycarboxylic acids and 8001685-7 derivatives thereof, such as dimethyl hydroxy terephthalate and the like. A particularly suitable branching material is trimellitic anhydride.

Although the relative amount of branching agent may vary, this amount is always kept at a low value, i.e. at most about 5.0 mole% per 100 moles of carbonate units in a branched polycarbonate. Preferably, the branching component is present in a branched polycarbonate in an amount of about 0.5-3.0 mol%, based on the carbonate units in the polycarbonate.

In addition to the stabilizing agent of the invention, various other additives can be included in the subject materials, eg colorants, agents for imparting desired molding properties, reinforcing fibers, such as glass fibers and the like, and other fillers. In general, these fillers can be included in the polycarbonate (after its preparation) in an amount up to about 40.0% by weight, based on the total weight of the polycarbonate.

According to the present process for preparing a stable color thermal stabilized material, a polycarbonate and an effective amount of a stabilizing material selected from cyclic phosphonites of formula (3) of formula sheet (a), wherein R is a alkyl group, haloalkyl group, aryl group, halaryaryl group, alkaryl group or halogenated alkaryl group, cyclic phosphonites of the formula (4) of the formula sheet (b), wherein R has the definition given above and R 'represents an ethylidene group, a 2,2-dimethylpropylidene group or represents a group of formula (5) of the formula sheet, and mixtures of these cyclic phosphonites and cyclic ethers, followed by stirring and melt mixing until a homogeneous mixture is obtained.

According to the invention, more than one polycarbonate and more than one stabilizing material of formula (3) and / or (4) can be used, as well as other additives as mentioned above. As mentioned above, cyclic ethers can also be used in combination with the stabilizing phosphonite. It is easy to mix all components in the aforementioned amounts and stir the mixture and mix in the melt until a homogeneous mixture is obtained. Mixing can be carried out in any suitable manner, eg by stirring or by tumbling or the like, at the temperature of the environment; melt mixing can be carried out at temperatures ranging from melting temperature to about the decomposition temperature of the mixture, i.e., in a range of about 230 ° -370 ° C and preferably 300 ° -330 ° C.

- 8 -

The materials of the invention have many advantages. These materials not only exhibit a surprisingly and unexpectedly improved stability to thermal oxidation and a surprisingly improved color stability, but can also be prepared with readily commercially available starting materials by known methods and with existing polycarbonate equipment. Furthermore, the stabilizing material used herein with readily available starting materials can be prepared by relatively simple and known preparation methods. In addition, the material of the invention can be prepared by simply mixing and melt-mixing polycarbonate and stabilizing material without the need to carry out complex chemical reactions. Furthermore, the materials of the invention can be adapted to a particular purpose by suitably preparing the polycarbonate to be used to obtain lacquers, films, films, laminates and other molded articles according to any of the known molding and extrusion methods. Numerous other advantages of the invention will be apparent to those skilled in the art.

The materials of the invention can be used by forming a wide variety of structures for numerous applications. The subject materials can be shaped according to any of the known molding and extrusion methods, such as blow molding, foam molding, rotary molding, compression molding, extrusion and injection molding.

Preferred Embodiments The following non-limiting examples further illustrate the invention.

Example I

A polymer was prepared by converting equimolar amounts of bisphenol-A and phosgene at 25 ° C into dichloromethane containing triethyl-30 amine, phenol and sodium hydroxide. The polymer was isolated from the dichloromethane by precipitation. The carbonate homopolymer thus prepared was then extruded in the form of a rod at a temperature of about 300 ° through a Sterling extruder and comminuted into granules. Thousands of grams of the granules were then injection molded in a Van Dorn injection molding machine (103.5 cm) into samples of 5.1 cm x 7.6 cm x 0.32 cm (thickness) at molding temperatures of 316 ° C and 345 ° C.

Oxidative deterioration and deterioration in color occurred; the deterioration in color was evident from the presence of 8001685-9 yellow shaped plates in the shaped articles. In addition, the yellowness index (GI), determined with a Gardner Colorimeter, was about 4-10.

Example II

A polycarbonate was prepared by reacting at 25 ° C 5 equimolar amounts of bisphenol-A and phosgene in dichloromethane as reaction medium containing thriethylamine, phenol and sodium hydroxide. The polymer was isolated from the dichloromethane by precipitation. The polycarbonate thus prepared was mixed with stirring and then melt-mixed with 10 grams (about 1.0 wt%, based on the polymer) 3,9-diphenol-2,4,8,10-10 tetraoxa-3, 9-diphosphaspiro [5.5] undecane and then extruded in the form of a bar through a Sterling extruder at a temperature of about 300 ° C and comminuted into granules. Quantities of one thousand gram grains were then injection molded into a Van. Dorn Injection Molding Machine 3 (103.5 cm) molded into 5.1 cm x 7.6 cm x 0.32 cm (thickness) samples at 15 molding temperatures of 316 ° C and 345 ° C.

The samples formed showed no yellowing, indicating that the undecane imparted oxidation stability and color stability to the polycarbonate. Furthermore, the yellowness index of the samples was 1.5, which confirmed the color stability.

Example III

In this example, it is shown that the cyclic phosphonites used as stabilizing materials according to the invention not only provide stabilized color polycarbonate materials, but are also more effective stabilizers in lesser amounts by weight at the same phosphorus levels as the known stabilizers, eg, listed in the table below. R-51 ", a 1: 2 (w / w) mixture of isooctyldiphenylphosphite and a stabilizing epoxide, the" R-501 "listed in the table below which is 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexanecarboxylate. The cyclic phosphonite 30 used in this example is 2-phenyl-4,5-benzo-1,3,2-dioxaphospholane. All samples used below contain about 33ppm of phosphorus when using the stabilizers in the weights listed in the table.

The preparation of the samples was performed according to the method of Example II, except that the stabilizers listed in the table were used in the amounts by weight also reported; the samples were formed at temperatures of 316 ° C and 345 ° C as in the previous examples. The values for the yellowness index at 316 ° C and 345 ° C and the change in the yellowness index at 345 ° C are also listed in the table; an increase in this index means a - 10 -

TABLE

Stabilizer Quantity _GI A GI_

316 ° C 345 ° C 345 ° C - 316 ° C

R-51 0.1 -0.3 +1.3 + 1.6 (1) 0.025 -0.3 +1.1 + 1.4 5 R-502 0.07 no color-reducing effect (D + R-502 0.025 + 0.07 -0.3 +1.1 + 1.4 (1) -2-phenyl-4,5-benzo-1,2,2-dioxaphospholane

It is clear from the above data that the stabilizing materials of the invention are active in lesser amounts than certain known stabilizing agents, although the phosphorus concentration is the same; the increase in the yellowness index is less for the stabilizing material of the invention than for the known stabilizing agents.

8001685

Claims (24)

A stable color thermal stabilized material, characterized by a mixture of polycarbonate and an effective amount of stabilizing material selected from cyclic phosphonites of the formula (3) of the formula sheet, wherein R is an alkyl group, haloalkyl group, aryl group, haloaryl group , alkaryl group or halogenated alkaryl group? cyclic phosphonites of the formula (4) of the formula sheet, wherein R has the definition given above and R 'represents an ethylidene group, propylidene group, 2,2-dimethylpropylidene group or a group of formula (5) of the formula sheet; and mixtures of one or more of these cyclic phosphonites and one or more cyclic ethers. Material according to claim 1, characterized in that the stabilizing agent is 3,9-diphenyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro- [5.5] undecane. Material according to claim 1, characterized in that the stabilizing agent is 2-phenyl-4,5-benzo-1,3,2-dioxaphospholane. Material according to claim 1, characterized in that the stabilizing agent is 2-phenyl-5,5-dimethyl-1,3,2-dioxaphosphorinaa. The material according to claim 1, characterized in that the stabilizing agent is a mixture of 2-phenyl-4,5-benzo-1,3,2-dioxaphospholane, 3,9-a diphenyl-2,4,8,10 -tetraoxa-3,9-diphosphaspiro- [5,5] undecane, oxiran and substituted 20-oxetan. 6. Material according to claims 1-5, characterized in that the polycarbonate is a homopolymer polycarbonate. The material according to claim 6, characterized in that the polycarbonate is a bisphenol A polycarbonate. Material according to claim 6, characterized in that the polycarbonate is a 3,3 ', 5,5'-tetramethylbisphenol-A polycarbonate. Material according to claim 6, characterized in that the polycarbonate is a dichloroethylidene polycarbonate. 10. Material according to claim 6, characterized in that the poly-30 carbonate is a copolymer polycarbonate. A material according to claims 1-10, characterized in that the stabilizing agent is present in an amount of about 0.02-2.0% by weight, based on the total composition. A material according to claim 11, characterized in that the stabilizing agent is present in an amount of less than about 1.0% by weight, based on the total composition. 13. A process for preparing a stabilized stabilized material of thermal oxidation, characterized in that an o η η λ t or - 12 - polycarbonate and an effective amount of stabilizer selected from cyclic phosphonites according to formula (3) of the formula sheet wherein R represents an alkyl group, haloalkyl group, aryl group, haloary group, alkaryl group or halogenated alkaryl group, cyclic phosphonites of the formula (4) of the formula sheet, wherein R has the definition given above and R 'represents an ethylidene group, propylidene group, 2,2-dimethylpropylidene group or a group of the formula (5) of the formula sheet, and mixing mixtures of one or more of these cyclic phosphonites and one or more cyclic ethers; and stirring the mixture and mixing in the melt until homogeneous. material is obtained. 14. Process according to claim 13, characterized in that the stabilizing agent used is 3,9-diphenyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro- [5,5] undecane. 15. Process according to claim 13, characterized in that 2-phenyl-4,5-benzo-1,3,3-dioxaphospholane is used as stabilizer. IS. Process according to Claim 13, characterized in that the stabilizing agent used is 2-phenyl-5,5-dimethyl-1,3,2-dioxaphosphorinane. 17. Process according to claim 13, characterized in that the stabilizing agent comprises a mixture of 2-phenyl-4,5-benzo-1,3,2-dioxophospholane, 3,9-20 diphenyl-2,4,8,10- tetraoxa-3,9-diphosphaspiro- [5,5] undecane and an epoxide was used. 18. Process according to claims 13-17, characterized in that a homopolymer polycarbonate is used as the polycarbonate. 19. Process according to claim 18, characterized in that a bisphenol-A polycarbonate is used as the polycarbonate. 20. Process according to claim 18, characterized in that a 3,35,5'-tetramethylbisphenol-A-polycarbonate is used as the polycarbonate. 21. Process according to claim 18, characterized in that a dichloroethylidene polycarbonate is used as the polycarbonate. Process according to claims 13-17, characterized in that a copolymer polycarbonate is used as the polycarbonate. 23. Process according to claims 13-22, characterized in that the stabilizing agent is used in an amount of 0.02-2.0% by weight, based on the total composition. A method according to claim 23, characterized in that the stabilizing agent is used in an amount of less than about 1.0% by weight, based on the total composition. 8001685 S 2348-1022 Ned. - Appendix 4 General Electric Company OR p 'D / 2 y 2 R - P' S (1) tv (2) R - PN ° «1 \ * J 3 / ° 'CH - 0 131 a - P7 2 \ c / 2 '\ V / \ R 0. CH / W-O ^ 2 2 W R - ΐ R '(5) Toj \ _ / No 8001685