NL8006110A - POLYCARBONATE CONTAINING MATERIAL STABLE AGAINST HYDROLYSIS. - Google Patents

Description

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S 2348-1083 P&C

Polycarbonate-containing material that is stable against hydrolysis.

The invention relates to an improved transparent and colorless polycarbonate material which is resistant to embrittlement and cloudiness upon exposure to elevated temperatures and moisture. This improved polycarbonate material contains a mixture of an aromatic polycarbonate and an aliphatic. bis (expoxyether) as a stabilizing agent against hydrolysis.

Polycarbonate resins have found extensive application in industry for the preparation of many plastic parts. Increased use is due in part to the toughness and transparency of aromatic polycarbonates. Polycarbonate resins have been extensively used as glazing materials to replace glass. Transparent polycarbonates have also been used to manufacture bottles with superior fracture resistance compared to glass bottles. The polycarbonates as such are widely accepted for the manufacture of bottles. In the manufacture of bottles, transparent polycarbonates are currently used to form baby food bottles because of the clear safety aspect of superior crush resistance. Unfortunately, these transparent baby food bottles have the drawbacks of becoming cloudy and slightly brittle after sterilization in water or moisture at elevated temperatures. When this takes place, the purpose for which the transparent polycarbonates became attractive, i.e. to form baby food bottles, is frustrated. These difficulties, especially cloudiness, are exacerbated by adding color stabilizers such as organophosphites to the polycarbonate resin. The addition of organophosphites as stabilizers to polycarbonate resins is known and is described in many patents, including U.S. Patent 4,138,379. In general, color stabilizers are required to provide transparent, colorless molded parts.

Without these color stabilizers, the molded parts have poly-30 carbonate. generally the tendency to show a yellow tint.

However, the addition of color stabilizers to polycarbonate resins generally adversely affects the stability of the polycarbonate resin against hydrolysis. Although the addition of color stabilizers to polycarbonate resin results in a polycarbonate which is generally colorless, this addition also results in a polycarbonate resin whose hydrolysis stability is inferior to that of polycarbonate resin without color stabilizer.

Several patents are directed to the use of epoxy compounds in combination with polycarbonates. For example, U.S. Pat. No. 3,489,716 describes the use of a cycloaliphatic 8006110-2-epoxy compound containing 1,2-cycloaliphatic rings with polycarbonates. U.S. Pat. No. 3,634,312 describes the use of a wide variety of expoxy compounds which can be used with a copolycarbonate, especially poly (bisphenol A carbonate co-phosphite). The cycloaliphatic epoxy compounds are generally unsuitable in accordance with the invention since they both exhibit some turbidity after autoclaving with steam. Furthermore, the phosphite-containing polycarbonates are generally unsuitable since they also lead to cloudiness of clear bottles after autoclaving with steam.

US Pat. No. 3,839,247 discloses that the opacity of clear polycarbonate bottles upon exposure to water or moisture at elevated temperatures can be eliminated by incorporating an aranatic or aliphatic epoxy compound into the polycarbonate. Although the inclusion of aromatic epoxy compounds in polycarbonate IS solves the problem of cloudy and brittle, the bottles formed from this material generally have a pinkish tint. The use of the aliphatic epoxy compounds disclosed in U.S. Pat. No. 3,839,247 solves the pinkish tint problem, but generally results in a material which, after exposure to a high moisture content and a high temperature, tends to be more brittle. are then the polycarbonate containing the aromatic epoxy compounds. Therefore, there is a need for polycarbonate bottles that do not become cloudy or brittle when exposed to high moisture and high temperature conditions and that are transparent and colorless.

It has now been found that the above drawbacks, ie, becoming cloudy and brittle, and discoloration of clear polycarbonate used for manufacturing containers, such as bottles, can be eliminated by blending in the polycarbonate, which may be optionally with a color stabilizer to include a small amount of an aliphatic bis (epoxy-30 ether) compound. The material obtained is found to be transparent and colorless when molded into bottles and to exhibit excellent cloudiness and brittleness when exposed to elevated temperatures and moisture such as sterilization.

The arcmatic polycarbonates to be used according to the invention are homopolymers and copolymers and mixtures thereof, which are prepared by reacting a divalent phenol with a carbonate precursor.

The presentative examples of. only bivalent phenols which can be used according to the invention are bisphenol-A [2,2-bis (4-hydroxyphenyl) -40 propane], bis (4-hydroxyphenyl) methane, 2,2-bis (4-hydroxy-3 methylphenyl) - 8 0 0 6 1 1 0

Jr * - 3 - propane, 4,4-bis (4-hydroxyphenyl) heptane, 2,2- (3,5,31,5, -tetrachloro-4,4'-dihydroxyphenyl) propane, 2,2 (3, 5,31,5'-tetrabromo-4,41-dl-hydroxyphenyl) -propane and (3,3'-dichloro-4,4'-dihydroxydiphenyl) -methane. Other bisphenol bivalent phenols are also available and are described in U.S. Patents 2,999,835, 3,028,365, and 3,334,154.

It is of course possible to use two or more different bivalent phenols or a copolymer of a bivalent phenol with a glycol or with a polyester with terminal hydroxy or acid groups, or with a dibasic acid, in the case of a carbonate copolymer: instead of a homopolymer is desired. It is also possible to use mixtures of the above materials to provide the aromatic carbonate polymer.

The carbonate precursor can be a carbonyl halide, a carbonate ester or a haloformate. Examples of carbonyl halides to be used are carbonyl bromide, carbonyl chloride and mixtures thereof.

Representative examples of carbonate esters to be used are diphenyl carbonate, di (halophenyl) carbonates such as those (chlorophenyl) carbonate di (bromophenyl) carbonate, di (trichlorophenyl) carbonate, di (tribromo-20 phenyl) carbonate, etc., di (alkylphenyl carbonates such as di (tolyl) carbonate, etc., di (naphthyl) carbonate, di (chloromaphthyl) carbonate, phenyl tolyl carbonate, chlorophenyl chloronaphthyl carbonate, etc., or mixtures thereof. Examples of suitable haloformates are bis-haloformates of divalent phenols (bischloroformates of hydroquinone, etc.) or glycols (bishalogen formates of ethylene glycol, neopentyl glycol, polyethylene glycol, etc.)

Although other carbonate precursors can also be used, carbonyl chloride, also known as phosgene, is preferred.

The polymeric derivatives of a divalent phenol, a dicarboxylic acid and carbonic acid can also be used. These materials are described in U.S. Patent 3,169,121.

The aromatic carbonate polymers used in accordance with the invention can be prepared using a molecular weight regulator, an acid acceptor and a catalyst. Examples of molecular weight regulators to be used are monovalent phenols such as phenol, chroman-I, para-tert-butylphenol, para-bromo-phenol, primary and secondary amines, etc. Preferably phenol is used as molecular weight regulator.

Both an organic and inorganic acid acceptor can be used. Examples of suitable organic acid acceptors are tertiary amines 40 such as pyridine, triethylamine, dimethylaniline, tributylamine, etc. Examples of suitable inorganic acid acceptors are alkali or alkaline earth metal hydroxides, carbonates, bicarbonates or phosphates. .

Any suitable catalyst which contributes to the polymerization of bisphenol-A with phosgene can be used as the catalyst. Examples of suitable catalysts are tertiary amines such as, for example, triethylamine, tripropylamine, Ν, Ν-dimethylaniline, quaternary ammonium compounds such as, for example, tetraethylammonivim bromide, cetyltriethylamonium bromide, tetra-n-hepthylammonium, tetra-n-propyl ammonium, tetra-n-propyl ammonium. n-butylammonium iodide 10 and benzyl trimethyl ammonium chloride ,. and quaternary phosphonium compounds such as, for example, n-butyltriphenylphosphonium bromide and methyltriphenylphosphonium bromide.

Branched polycarbonates can also be used, for the preparation of which a polyfunctional aromatic compound is reacted with the divalent phenol and the carbonate precursor to yield a thermoplastic polycarbonate with random distribution of the branches.

These polyfunctional aromatic compounds contain at least three functional groups, namely carboxyl groups, carboxylic anhydride groups, haloformyl groups or mixtures thereof. Examples of these polyfunctional aromatic compounds are trimellitic anhydride, trimellitic acid, trimellityl trichloride, 4-chloroformyl phthalic anhydride, pyromellitic acid, pyromellitic dianhydride, mellitic acid, mellitic anhydride, triminic acid, benzophenon tetracarboxylic acid, benzophenone tetracarboxylic acid, benzophenone tetracarboxylic acid, benzophenone tetracarboxylic acid, benzophenone tetracarboxylic acid, and the haloformyl derivatives thereof.

A mixture of linear polycarbonate and a branched polycarbonate can also be used.

Examples of color stabilizers that can be mixed with the polycarbonate resins are organophosphites according to the general 9 10 11

formula (l) .of the formula sheet, in which each of the symbols R, R and R.

represents a hydrogen atom, alkyl group, aryl group, cycloalkyl group, aralkyl group 11, or alkaryl group, at least one of the symbols R-R 35 having a meaning other than hydrogen. Preferably, these groups contain 1 to about 20 carbon atoms. The phosphite is present in a color-stabilizing amount. Generally, this amount ranges from about 0.005 to about 1.0 wt%, and more particularly from about 0.01 to about 0.02 wt%, based on the polycarbonate-containing composition.

These phosphites and their use as color stabilizers are described 8006110

Jf-5 - wrote in U.S. Patent 4,138,379.

The aliphatic bis (epoxy ether) compounds are best

represented by the general formula (2) of the formula sheet, wherein R

a divalent saturated aliphatic hydrocarbon group with preferably 1 2 5 1 to about 20 carbon atoms; each of the symbols R and R represents a divalent aliphatic hydrocarbon group with preferably 1 to about 6 carbon atoms; each of the symbols n and m is a number with a value of 3 4 5 6 7 8 0 - 1; and each of the symbols R, R, R, R, R and R represents a hydrogen atom or an alkyl group, preferably having 1 to about 20 carbon atoms.

Examples of alkylene groups preferably represented by the symbol R are -CH2 -, - CH2-CH2-CH2, -C1 -C (CH3) 2-CH2 ~, -CH2- (CH2) g-CH2 -, - CH ^ C (CH ^) H-CH2 ”, and the like. Examples of alkylene groups preferably represented by R1 and R2 are -CH2 ~, -CH2-CH2-, CE ^ -CE ^ -CR ^ -, -CH2 ~ C (CH3) H-CH2-, -CH2-CH2-CH2 -CH2-, and the like.

Preferred compounds of formula (2) are those wherein both n and m are 1. Even more preferred compounds of formula (1) are 1 where both n and m is 1, R and R represent a -CEL group, 3 8 and R are -R hydrogen.

The amount of bis-epoxy ether 20 ± s present in the polycarbonate material is an amount effective to improve the stability of the material against hydrolysis. Generally, this amount is about 0.01-0.50 wt%, and preferably about 0.02-0.15 wt%, based on the composition.

Preferred Embodiments The invention is further illustrated in the following nonlimiting examples.

EXAMPLE I

An aromatic solid polycarbonate prepared from 2,2-bis (4-hydroxyphenyl) propane and phosgene in the presence of an acid acceptor and a molecular weight regulator, which polycarbonate has an intrinsic viscosity of about 0.57 dl / g was fed into an extruder at a temperature of about 274 ° C and granulated. The granules were then dried at about 121 ° C for about 16 hours. Then test plates with a thickness of about 0.32 cm were injection molded at a temperature of about 316 ° C.

EXAMPLE II

A polymer prepared according to the method described in Example I was mixed with 0.075 wt% tris (nonylphenyl) phosphite as a color stabilizer before granulation; the mixture was then granulated and plateleted as described in 8 η n r 1 1 n - 6 - example I.

EXAMPLE III

A polymer prepared according to the method described in Example I was mixed with 0.075 wt% tris (nonylphenyl) phosphite and 0.051 wt% butanediol (bisglycidyl ether) before granulation; the mixture was then granulated and plateleted as described in Example I.

EXAMPLE IV

A polymer prepared in the manner described in Example 1, IQ, was mixed with 0.075 wt% tris (nonylphenyl) phosphite and 0.102 wt% butanediol (bisglycidyl ether) before granulation; then the mixture was pelleted and plateleted as described in Example I.

EXAMPLE V

A polymer prepared in the manner described in Example I was mixed with 0.029 wt% butanediol (bisglycidyl ether) before granulation; then the mixture was pelleted and platelets as described in Example 1. The platelets were examined for light transmission; the results were as follows: 89.3% transmission before autoclaving; 87.2% transmission after autoclaving for 24 hours; 85.6% transmission after 48 hours autoclaving; and 83.1% transmission after 72 hours of autoclaving.

Each of the test disks prepared above was subjected to ASTM Test Method D1003 to determine the light transmission in the samples before and after autoclaving at about 127 ° C; the results are given in Table A below. The higher the percentage transmitted, the better the clarity of the sample. The test platelets obtained above were also subjected to the ASTM 30 Yellowness Index Expression D1925-63T ("Yellow Index Test") to determine the color; the results are given in Table B. The greater the yellowness index, the more unwanted color displayed by the samples.

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<ΰ β dP β -Η Φ β • Η · Ρ 03 03 β • Ρ φ 6 Ή 03 φ

β TJ

(Ö S 03 HI Is C0 ρ id m - - - - +3 Λ 3 ω σι σι σι • Ρ Φ 3 00 00 00 00 Λ Λ η ϋ ο -Ρ Ρ ο Ρ! '0 -Ρ' 0 3 dP> tö Ό Η Φ φ Η ^ Λ Η Η> Ρ Η W Η Η Ο 8006110 *

- 8 TABLE B

- GI

Example (molded at approx. 316 ° C) I 7.0 5 II 4.9 III 4.7 IV 4.8

As shown in Table A, the samples containing the bis-epoxy ether of the invention as a hydrolysis stabilizer, even in the presence of an organophosphite as a color stabilizer (Examples III-IV), exhibit superior light transmission, indicating a lower degree of turbid and thus superior hydrolysis stability over the samples which do not contain a hydrolysis stabilizer (Examples I and II).

Table B shows that the presence of the present hydrolysis stabilizers does not adversely affect the color stability of the polycarbonate materials.

Further test samples were prepared according to the method of example I, with the difference, however, that the injection molding took place at about 360 ° C. These samples were subjected to the yellowness index test described above; the results are shown in Table C below.

TABLE C

1 GI

Sample (additives) _ (formed at BfèQjGl (A) Control, no additives 16.8 25 (B) 0.075 wt% tris (nonylphenyl) phosphite 10.6 (C) 0.075 wt% tris (nonylphenyl) phosphite and 0.087 wt % epoxidized soybean oil 12.6 (D) 0.075 wt% tris (nonylphenyl) phosphite and 0.18 wt% bisphenol A-diglycidyl ether 34.7 (E) 0.075 wt% tris (nonylphenyl) phosphite and 0.102 wt% butanediol bis (glycidyl ether) 10.0 (F) 0.075 wt% tris (nonylphenyl) phosphite and 0.051 wt% butanediol bis (glycidyl ether) 11.2

As shown in Table C, the test samples formed from polycarbonate mixtures containing organophosphite as a color stabilizer and the present hydrolysis stabilizers (Ξ and F) have a lower yellowness index (a yellowness index comparable to that of test sample B formed from a polycarbonate-containing mixture containing only the color stabilizer and no hydrolysis stabilizer) than test specimens formed from polycarbonate-containing mixtures containing the same color stabilizer but known hydrolysis stabilizers (C and B).

80 0 6 1 1 0 - 9 -

The invention is not limited to the above-described embodiments, since numerous modifications are of course possible within the scope of the invention.

8006110

Claims (10)

Polycarbonate material with improved hydrolysis stability, characterized by a mixture of a polycarbonate polymer and a stabilizing amount of a bis-epoxy ether according to the general formula (2) 5 of the formula sheet, wherein R represents an alkylene group, each of the symbols R * and R ^ an alkylene group. proposes; each of the symbols R 1, R 1, R 1, R 1, R 1, 8 and R represents a hydrogen atom or an alkyl group; and each of the symbols n and m is a number with a value of O or 1. 2. The material according to claim 1, characterized in that R represents an alkyl-boron group having 1 to about 20 carbon atoms. Material according to claim 1 or 2, characterized in that each of the 1 2 symbols R and R represents an alkylene group with 1 to about 6 carbon atoms. 4. Material according to claims 1-3, characterized in that n and m 15 have the value 1. Material according to claims 1-4, characterized in that the symbols 3 8 R -R are hydrogen. 6. Material according to claims 3-5, characterized in that each of the 1 2 symbols R and R represents a methylene group. Material according to claims 2-6, characterized in that R represents a butylene group. Material according to claims 1-7, characterized by an organophosphite as a color stabilizing agent. 9. Material according to claims 1-8, characterized by about 0.01-0.5% by weight of 25 bis-epoxy ether. The material according to claim 9, characterized by about 0.02-0.15% by weight of bis-epoxy ether. 80 0 6 1 1 0 S 2348-1083 Eng. _ ACCESSORY SHEET j Appendix 4. OR10 (1) R90_p ^ XJR11 0 0 3 / \, / \ (2> R “9? ~ IRl) n“ 0 “R - 0 - (R2) m - C-C - R5. R 'P.5 S3 I4 8006110