DE2003432C2 - Thermoplastic molding compound that is color-stable at elevated temperatures - Google Patents

Description

characterized in that the epoxy compound (B) is an epoxidized cycloaliphatic compound which has 1 or 2 cycloaliphatic rings of 6 carbon atoms each, with at least one oxygen bridge being bonded to adjacent carbon atoms in a cycloaliphatic ring and that it is in an amount of 0 .01 to 0.50% by weight, based on the total weight of the mass, is present: n

2. Molding composition according to claim i, characterized in that the epoxidized present therein cycloaliphatic compound is 3,4-epoxycyclohexylmethyl-S ^ -epoxycyciohexanecarboxylate.

The invention relates to a thermoplastic molding composition which is color-stable at elevated temperatures

(A) a polycarbonate based on a dihydric phenol and

(B) an evenly distributed epoxy compound.

It is known that many engineering thermoplastics have to be heat and color stable, although that Polymer itself does not have these properties. To a thermoplastic polymer heat and color resistance A variety of materials can be used to lend. Are particularly suitable for this Phosphites, which are known to stabilize numerous thermoplastic polymers. In the case of the aromatic Polycarbonate resins are phosphites, as described in US-PS 33 05 520, for the stabilization of Polycarbonates are very suitable. In addition to the phosphites, other materials are suitable together with phosphites, such as B. Tetraaryl tin compounds, according to Canadian Patent 7 27 700. Furthermore, has It has been shown that mixtures of different phosphites are also excellent stabilizers suitable for polycarbonate resins.

From US-PS 31 86 961 finally, in addition to a variety of other materials, the use of epoxy esters and glycidyl ethers known as plasticizers for polycarbonates. You will be in a crowd from 33 parts by weight to 67 parts by weight of polycarbonate added and show in addition to the plasticizing Effect also has a light stabilizing effect.

Surprisingly, it has now been found that certain compounds by themselves are very low Lot uses an excellent heat and color stabilizer for aromatic polycarbonate resins represent.

The object of the invention is therefore to create a thermonlastic table which is color-stable at elevated temperatures Molding compound

(A) a polycarbonate based on a dihydric phenol and

(B) an evenly distributed epoxy compound.

This object is achieved according to the invention in that the epoxy compound (B) is an epoxidized cycloaliphatic A compound having 1 or 2 cycloaliphatic rings each consisting of 6 carbon atoms, where at least one oxygen bridge to adjacent carbon atoms in a cycloaliphatic ring is bound and that they are in an amount of 0.01 to 0.50 wt .-%, based on the total weight of the Mass, is present.

It has proven to be particularly advantageous if the epoxidized cycloaliphatic present in the molding compound Compound S ^ -Epoxycyclohc-xylmethyl-S ^ - is epoxycyclohexane carboxylate.

In the following, the principle and the practical implementation of the present is based on the examples Invention in more detail Unless otherwise is expressly noted, the parts or percentages mentioned relate to the weight.

example 1

A polycarbonate which in dioxane at 30 ⁰ C has a limiting viscosity number (intrinsic viscosity) of 0.50 is obtained by essentially equimolecular amounts of 2.2'-bis (hydroxyphenyl) propane in the presence of an acid acceptor, such as. B. sodium hydroxide, and a catalyst, such as. B. triethylamine with a molecular weight regulator, such as. B. phenol is made to react with phosgene. The polycarbonate produced in this way is mixed at room temperature in a laboratory mixer with 0.15% by weight S ^ -epoxycyclohexylmethyl-S ^ -epoxycyclohexane carboxylate (hereinafter referred to as stabilizer) and 0.0008% by weight purple oil paint, an organic dye. The mixture is then dried at 121 ° C. for 16 hours. The mixture is then extruded at 273 ° C. and chopped into tablets. These are then dried at about 121 ° C. for about 16 hours. Then clear and transparent sample discs mm with a diameter of 51 mm and a thickness of 3.1, which are hereinafter referred to as Sample 2, separately injection molded at temperatures of about 315 ° C and about 360 ⁰ C. Sample disks with dye alone, which are referred to below as sample 1, were also produced from the poly-olycarbonate. After shaping, the samples are exposed to high temperatures (heat aging) in accordance with ASTM Yellow Color Index Versiich D 1925-63T, and the following results are obtained.

Table 1

sample Formed 360 c Heat aged
called I40T 4.6 1 week 315 C 2.5 315 (36 (i c 1. Control
(without stabilizer) 3.7 8.2 12.8 2. With stabilizer 2.6 5.8 7.3

According to the yellowness index test, the higher number means the stronger color. It can be seen that a polycarbonate containing the stabilizer according to the invention has a significantly better color fastness as unstabilized polycarbonates.

Example 2

Example I is repeated with the modification that the test disks instead of the purple oil paint 0.0077% by weight of ultramarine blue as a pigment, and that the mixture is not at 121 ° C, but at 76 ° C is dried. The following results are obtained.

Table 2

Formed

315 C 360 C

Warming everything
at 140 C

I week

315 C 360 C

1st control 2.6 2.6 10.5 13.9
(without stabilizer)

2. With stabilizer 1.4 1.7 4.7 7.9

The present invention relates to a heat and color stable aromatic polycarbonate which is a has a certain stabilizer evenly distributed. The stabilizer used herein is one epoxidized cycloaliphatic compound which has 1 to 2 cycloaliphatic rings of 6 carbon atoms, each of which has at least one oxygen bridge to adjacent carbon atoms in at least bound to a cycloaliphatic ring. The amount of cycloaliphatic used herein Compound can be from 0.01 to 0.50 weight percent based on the weight of the total composition. Alone by using the epoxidized cycloaliphatic compound, excellent heat and color fastness become excellent Obtained polycarbonate resins.

In general, all epoxidized cycloaliphatic compounds within the aforementioned Limits can be used in practicing the present invention. Instead of the example used S ^ -epoxycyclohexyl-methyl-S ^ -epoxycyclohexane-carboxylaies the following compounds lead to practically the same results:

J ^ -Epoxy-o-methylcyclohexylmethyl-B ^ -epoxy-6-methylcyclohexane-carboxylate,

2.3-epoxycyclohexyl-methyl-3.4-epoxycyclohexane-carboxylate,

4 .- (3,4-epoxy-5-methylcyclohexyl) -butyl-3,4-epoxycyclohexane carboxylate,

3.4-epoxycyclohexyl-ethylene oxide,

Di ^ -epoxy-O-methylcyclohexylmethyl adipate.

Cyclohexylmethyl S ^ -epoxycyclohexane carboxylate and

S ^ -Epoxy-ö-methylcyclohexylmethyl-

6-methylcyclohexyl carboxylate.

In the practice of the present invention, the epoxidized cycloaliphatic compound can range from b to to have 30 carbon atoms. Preferably at In carrying out the present invention, the epoxidized cycloaliphatic compound 3.4-epoxycyclohexylmethyl-3.4-epc) xycyclohexane-carboxylate.

As stated above, the stabilizer described above is more aromatic for stabilization Polycarbonate resins useful. In principle, all aromatic polycarbonates can be used will. In general, the aromatic polycarbonates are polymers of dihydric phenols. The herein Usable dihydric phenols are bisphenols, such as. B.

1.1 bis (4-hydroxyphenyl) methane,

2.2-bis (4-hydroxyphenyl) -prcpan,

2.2-bis (4-hydroxy-3-methylphenyl) propane

or4,4-bis (hydroxyphenyl) heptane;

dihydric phenol ethers, such as. B.

Bis (4-hydroxyphenyl) ether or

Bis (3.5-dichloro-4-hydroxyphenyl) ether;

Dihydroxydiphenyls, e.g. B.

p.p'-dihydroxydiphenyl or

33'-dichloro-4.4'-dihydroxydiphenyl:

Dihydroxyarylsulfones, e.g. B.

Bis (4-hydroxyphenyl) sulfone,

Bis (3.5-dimethyl-4-hydroxyphenyl) sulfone

or bis (3-methyl-5-ethyl-4-hydroxyphenyl) -

sulfone; Dihydroxybenzenes, resorcinol,

Hydroquinone, halogen and alkyl substituted

Dihydroxybenzenes, e.g. B.

1 4-dihydroxy-2-chlorobenzoI,

1,4-dihydroxy-23-dichlorobenzene or

1 ^ -dihydroxyO-methylbenzene, and

Dihydroxy-dip1: e.nyl-sulfoxide,

such as B. bis (4-hydroxypheny!) - sulfoxide or

Bis (3.5-dibromo-4-hydroxyphenyl) sulfoxide.
Numerous other dihydric phenols according to US Pat. Nos. 29 99 835, 30 28 365 and 31 53 008 are available for the production of polymeric carbonates. Of course, two or more different dihydric phenols or a copolymer of a dihydric phenol with glycol, a hydroxy- or acid-blocked polyester or a dibasic acid can be used in the event that a copolymeric carbonate or an interpolymer is used instead of a homopolycarbonate! the aromatic polycarbonate molding compositions according to the invention is sought.

In general, the polycarbonates used herein are obtained in that a divalent Phenol with a carbonate precursor in the presence of a molecular weight regulator and an acid acceptor is brought to implementation. The carbonate precursors useful herein are either a carbonyl halide, a carbonate ester or a haloformate. The carbonyl halides which can be used herein are carbonyl bromide, Carbonyl chloride, carbonyl fluoride, etc., or mixtures thereof. Typical examples for herein usable carbonate esters are diphenyl carbonate. Di (halophenyl) carbonates. such as B. Di (chlorophenyl) carbonate, Di (bromophenyl) carbonate, di (trichlorophenyl) carbonate or di (tribromophenyl) carbonate; Di (alkylphenyl) carbonates, such as. B. Di (tolyl) carbonate; Di (naphthyl) carbonate, di (chloronaphthyl) carbonate, Phenyl tolyl carbonate, chlorophenyl chloronaphthyl carbonate or their mixtures. The halogen formates which can be used herein include the bis-halogen formates the dihydric phenols (bischloroformates of the cyclroquinone, etc.) or glycols (bis-halogen formates of ethylene glycol, neopentyl glycol, polyethylene glycol, etc.). Phosgene is preferably used, although other carbonate precursors are well known to those skilled in the art.

As has already been stated above, the conversion in terms of an acidic acid can be excluded.

5 6

which is either an organic or such. B. phenol, cyclohexanol, methanol, para-tertiary

inorganic compound can be. Suitable butylphenol or para-bromophenol may be. Preferably

organic acid acceptor is a tertiary amine and is used as a molecular weight regulator phenol,

includes substances such as B. pyridine, triethylamine, from the above description can be seen.

Dimethylaniline or tributylamine. The inorganic - that the tasks mentioned by the present

Acid acceptor, either a hydroxide, an invention can be dissolved in an efficient manner

Carbonate, a bicarbonate or a phosphate of the alkali and that in the execution of the described

or alkaline earth metals. Process and the production of the listed mass

Certain changes can be made in the manufacture of aromatic polycarbonates,

usable molecular weight regulators can be such m

Claims (1)

Patent claims: 1. Thermoplastic molding compound made of ϊ that is color-stable at elevated temperatures (A) a polycarbonate based on a dihydric phenol and (B) an evenly distributed epoxy compound, in