JPH0112773B2 - - Google Patents

Description

[Detailed description of the invention]

Polycarbonates are well known and have been used in many field applications due to their outstanding properties. However, the resistance to organic solvents and stress cracking, for example, is inadequate for certain applications. Compared to polycarbonate, which is normally terminated with only phenol, pt-butylphenol or 2,6-dimethylphenol,
The polycarbonate according to the invention shows no change in mechanical or thermal properties. Furthermore, they are suitable for crosslinking, especially in the presence of photoinitiators and under irradiation with UV light, and are therefore resistant to organic solvents, resistant to stress cracking, and difficult to The addition of flame retardants makes it possible to produce polycarbonates with particularly good flame retardant properties. The present invention relates to the general formula () prepared using diphenol and a monofunctional chain terminator. In the formula, Z is a residue obtained by removing the hydroxyl group from diphenol, n is an integer from about 20 to 400, and E is in which m means 0 or 1 and R means H or _C1 - _C3 -alkyl.
Molecular weight w (weight average) between 20000 and 80000
The present invention relates to a method for modifying an aromatic polycarbonate having the following. More specifically, the present invention provides a polycarbonate or a polycarbonate mixture of the above formula (),
about 0.5 to 5% by weight, preferably about 1 to 3% by weight of a photoinitiator, based on the weight of the polycarbonate;
and, optionally, about 0.5 to 5% by weight, preferably between about 1 and 3% by weight, relative to the weight of the polycarbonate, of a compound having labile CH bonds (hereinafter referred to as a photoreductant); After adding between about 0.05 and 5% by weight, preferably between about 0.1 and 2% by weight of flame retardant, based on the weight of the polycarbonate, the polycarbonate is modified by irradiation with ultraviolet light. quality)
Regarding how to. The polycarbonate of the above general formula () has the general formula () HO-Z-OH () where Z can optionally be substituted with alkyl or halogen, and preferably has about 6 to 30 C atoms. Diphenols and/or their chlorocarbonate esters containing divalent aromatic radicals are added in a homogeneous or heterogeneous phase system according to methods known for the production of polycarbonates. About 0.05 and 5 mol %, preferably about 0.1 to 4 mol %, based on the number of moles of structural unit Z used
General formula () between mol% is prepared by reacting with a compound of formula (2) in which m and R have the meanings indicated for formula (). Polycarbonates that can be easily crosslinked by ultraviolet light are economical because the monomers used for chain termination are cheap, readily available on the market, and can be easily incorporated into polymers by methods known for making polycarbonates. It can be produced under certain conditions. Examples of compounds of formula () suitable according to the invention are acryloyl chloride, methacryloyl chloride, isopropenylphenyl chlorocarbonate and p-hydroxystyrene chlorocarbonate. In addition to the chain terminators according to formula () to be used according to the invention, all customary monofunctional phenols suitable for the synthesis of polycarbonates can also be used together according to the invention. Suitable examples of diphenols of formula () preferably containing 6 to 30 C atoms are hydroquinone, resorcinol, dihydroxydiphenyl,
Bis-(hydroxyphenyl)-alkane, bis-
(hydroxyphenyl)-cycloalkane, bis-
(hydroxyphenyl) sulfide, bis-(hydroxyphenyl) ether, bis-(hydroxyphenyl) sulfoxide, bis-(hydroxyphenyl) sulfone, α, α′-bis-(hydroxyphenyl)-diisopropylbenzene and These are nuclear alkylated as well as nuclear halogenated compounds. These and other suitable diphenols are described, for example, in U.S. Pat.
No. 3148172, No. 3271368, No. 2991273,
3271367, 3280078, 3014891, and 2999846, West German Patent Application Publication No. 1570703, 2063050, 2063052,
2211956 and 2211957, French patent no.
No. 1561518 and the book “H.Schnell, Chemistry
and Physics of Polycarbonates, Interscience
Publishers, New York, 1964. An example of a preferred diphenol is 2,2-bis-
(4-hydroxyphenyl)-propane, 2,2-
Bis-(3,5-dimethyl-4-hydroxyphenyl)-propane, 2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane, 2,
2-bis(3,5-dibromo-4-hydroxyphenyl)-propane and 1,1-bis-(4-hydroxyphenyl)-cyclohexane. Any mixture of diphenols of formula ()
It can be used as long as it does not conflict with other inventions. The polycarbonate is present in a small amount, preferably about 0.05 and 2.0 mol%, based on the diphenol used.
Branching can be achieved by incorporating between amounts of trifunctional or more than trifunctional compounds, in particular compounds with 3 or more than 3 phenolic hydroxyl groups. Polycarbonates of this type are known, for example, from West German Patent Application Nos. 1570533 and 1595762.
No. 2116974, No. 2113347 and No. 2500092
No. 1, United Kingdom Patent No. 1079821 and U.S. Patent No.
Described in No. 3544514. The production of the polycarbonate according to the invention can be carried out essentially by two known methods (H. Schnell,
Chemistry and Physics of Polycarbonahes,
Polymer Rev., Volume 27 et seq.
Interscience Publishers), which is briefly described below. 1. Production of aromatic polycarbonates in a heterogeneous phase system (phase boundary method) In this method, a diphenol of formula () is dissolved in an alkaline aqueous phase. The chain regulator according to formula (), which is necessary for the production of the polycarbonate according to the invention, is added to this alkaline phase either dissolved in an organic solvent or as such. After adding a suitable solvent to the polycarbonate, a two-phase mixture is formed into which about 0.
and phosgene between 60°C and 60°C. Addition of a catalyst results in a high molecular weight polycarbonate. The mixture is worked up by washing the organic phase and then distilling off the solvent, for example in a non-evaporative extruder at temperatures between about 280 and 330°C. Suitable organic solvents for polycarbonates and compounds of formula () are, for example, methylene chloride,
such as chlorobenzene and mixtures thereof,
It is known for the synthesis of polycarbonates. Suitable catalysts are those known for the synthesis of polycarbonates, such as triethylamine and tributylamine. 2 Preparation of polycarbonates in a homogeneous phase system (pyridine process) A diphenol according to the general formula () and a chain regulator according to the general formula () are dissolved in an organic base such as, for example, pyridine. After adding a suitable solvent to the polycarbonate, approximately 0 and 60
Pass phosgene at temperatures between . The pyridine hydrochloride formed during the reaction is separated off and the organic layer is washed with dilute HCl and then with water until neutral. Work-up is also carried out as described under (1), for example by distilling off the solvent in a non-evaporating screw. Besides pyridine, examples of suitable organic bases are triethylamine and tributylamine. Methylene chloride and chlorobenzene and mixtures thereof can be used as solvents for polycarbonate. If, in addition to or in place of the diphenols of formula (), chlorocarbonates of these are used, the amount of chain terminator required for processes (1) and (2) is as follows: ) is suitably calculated from the structural unit Z arising from the sum of bisphenols and their chlorocarbonate esters. In principle, all photoinitiators compatible with polycarbonates are suitable for the modification of polycarbonates according to the invention. Thus, for example, photoinitiators based on aliphatic and aromatic ketones in the broadest sense, including also glyoxalates and quinones, are suitable. Examples of ketones and glyoxalates in a more narrow sense are acetophenone, benzyl, benzoin, benzoin methyl ether,
Benzoin isopropyl ether, benzophenone, p-chloro-benzophenone, p-benzoylbenzophenone, dibenzalacetone, benzoylacetone, benzylacetone, deoxybenzoin, 2,4-dimethyl-benzophenone,
2,5-dimethylbenzophenone, 3,4-dimethylbenzophenone, 4-benzoyldiphenyl, 9-fluorenone, 4,4-bis-(dimethylamino)-benzophenone, 4-dimethylamino-benzophenone, dibenzyl Ketone, 4-methylbenzophenone, propiophenone, benzanthrone, ethyl phenyl glyoxalate,
These include t-butylphenylglyoxalate, trimethylsilyl phenylglyoxalate, and the like. Aromatic ketones or glyoxalates are preferred. Particular preference is given to benzophenone, benzoin, p-benzoylbenzophenone, t-butylphenylglyoxalate and trimethylsilyl phenylglyoxalate. Quinones, such as anthraquinone, 1-chloroanthraquinone, 2-chloro-anthraquinone, 2
-Ethylanthraquinone, 1-methylanthraquinone, 2-methylanthraquinone, 2-phenylanthraquinone, etc. can also be used as photoinitiators. Preferred quinones are 2-methylanthraquinone, 2-chloroanthraquinone, and 2-ethylanthraquinone. Other suitable photoinitiators are known to the skilled person and can be found in the following publications: J.
Kosar, “Light−Sensitive Systems,” John
Wiley & Sons, New York, 1965, No. 4
Chapter (“Unsaturated Compounds”), Chapter 5 (“Photopolymerization Processes”) and Chapter 8 (Photopolymerization of Vinyl
Monomers), “Chem.Revs.” Vol. 68, 125-
151 pages (1968), JFRabek “Photosensitized
Processes in Polymer Chemistry：A
Photochem. Photobiol. Vol. 7, pp. 5-57 (1968), G. Delzenne, “Sensitizers of
"Photopolymerization", Ind.Chim.Belge Volume 24,
pp. 739-764 (1965), and CMMc
Closkey and J. Bond. “Photosensitizers For
Polyester-Vinyl Polymerization”. Ind.Eng.
Chem. Vol. 47, pp. 2125-2129 (1955). The ultraviolet light irradiation necessary for the modification of polycarbonate according to the invention can be achieved with ultraviolet light using commercially available ultraviolet lamps, such as Philips HTQ4 or 7, Hanovia lamps, etc. The irradiation time is
Approximately 20 to 180 seconds, depending on the content of photoinitiator used and the nature of the sample. Examples of flame retardants suitable for the modification of polycarbonate according to the invention are compounds known and suitable for rendering polycarbonate flame resistant, and
West German Patent Application Nos. 2049358 and 2253072, U.S. Patent No. 3775367 and
3836490 and other documents with synergistic action. Examples of suitable compounds are alkali metal salts, in particular
For example, potassium isooctanoate, sodium isooctanoate, lithium isooctanoate, potassium perfluorooctanoate, sodium perfluorooctanoate, lithium perfluorooctanoate, 5-ethyl-dioxan-1,3-yl-5
- Potassium salts of carboxylic acids, rubidium isooctanoate, rubidium perfluorooctanoate and alkali metal salts of perfluoroalkanesulfonic acids such as potassium perfluoromethanesulfonate, potassium perfluorooctanesulfonate and potassium perfluorobutanesulfonate, It is a soluble alkali metal salt. Furthermore, lauric acid, stearic acid, oleic acid, phthalic acid monobenzyl ester, adipic acid monobutyl ester, p-octylbenzoic acid,
p-t-butylbenzoic acid, 3-(3,5-di-t
It is also possible to use the alkali metal salts of -butyl-4-hydroxyphenyl)-propionic acid and diglycolic acid monodecyl ester. Modification of polycarbonate according to the invention can be achieved in two stages. The first step is (a) by melting and isolating as a film, or (b) by mixing between about 280 and 330°C and optionally forming the polycarbonate into a sheet or other injection molded body. , the step of incorporating a photoinitiator and optionally a flame retardant and/or a photoreductor, the second step is ultraviolet light irradiation until crosslinking is achieved. When proceeding with step (b), it is preferred to add a substance, such as benzophenone, to the polycarbonate before mixing to activate the photoinitiator. The use of photoreducing agents together with photoinitiators is well known in the literature. (J.Am.Chem.Soc. vol. 83, p. 2795 (1961), J.Am.Chem.Soc. vol. 89, p. 3471 (1967) and Angew.Chem. p. 1032 (1972)
reference). As photoreducing agents, ie compounds with unstable CH bonds, mesitylene, dibenzyl ether, benzoic acid benzyl ester, polyglycol ethers or aliphatic polyesters can be used. The present invention also provides another method of photoinitiator activation, in which the polycarbonate containing the photoinitiator is exposed to the vapor of a compound having labile C-H bonds prior to irradiation, and then immediately exposed to ultraviolet light. Crosslinking can also be effected by irradiation. Compounds that can be used in this case are tetrahydrofuran, dioxane, chloroform, toluene,
It is xylene _{or CH2Cl2} . The amount of photoreductant to be incorporated depends on the amount of photoinitiator incorporated, but generally equimolar amounts of photoreductant are added based on the photoinitiator. Furthermore, depending on the amount of photoinitiator incorporated,
The amount of photoreducing agent used in the vapor state depends primarily on the surface to be crosslinked and the structure of the polycarbonate molding and the desired degree of crosslinking reaction. Another method for providing the polycarbonate of the invention with a photoinitiator and optionally with a photoreducer, optionally after incorporating a flame retardant, is to prepare the respective polycarbonate molded body by Well-known methods, e.g. U.S. Pat.
Using a method similar to that of No. 3,892,889, using a solution of a photoinitiator and optionally a photoreducing agent in a solvent inert towards the polycarbonate, by immersion or spraying. The amount of photoinitiator and optionally photoreducer to be used depends, again, primarily on the surface to be crosslinked and on the structure of the polycarbonate molding and on the desired degree of crosslinking reaction. The amount of photoinitiator and optionally photoreducer to be used on the polycarbonate surface according to this latter process variable is 10 ^-3 g/in each case for an average of 100 μ surface layer to be crosslinked.
It is about the size of cm ² . The treated polycarbonate moldings are then dried in a well-known manner and modified by ultraviolet light irradiation. Other high-energy radiation sources, such as electron beams, especially cathode radiation, can also be used for irradiating the polycarbonates of the invention, optionally after addition of sensitizers. The modified polycarbonate molding compositions obtainable according to the invention are resistant to organic solvents and, when compared with conventional polycarbonates, are distinguished by improved resistance to stress cracking. If flame retardants are added, even small amounts will result in a product rated as VO according to UL Subject 94. The modified polycarbonates obtainable according to the invention can be used as films and moldings in all cases where high resistance to stress cracking and at the same time high resistance to organic solvents is required. The following examples are intended to illustrate the gist of the invention in greater detail. The relative viscosities given were determined in methylene chloride at 25° C. and a concentration of 5 g/ml. In addition, the UL Subject 94 test below is
Dimensions: 127 x 12.7 x 1.6 mm, 10 pieces per sample
(1/16") and 127 x 12.7 x 3.2 mm (1/8") injection molded test bars.
The flame retardance of the sample is classified into V0, V1, or V2, and the classification criteria are as follows. V0: The average combustion and/or smoldering after removing the ignition flame does not exceed 5 seconds and does not produce drippings that ignite the cotton wool. V1: Average combustion and/or smoldering after removing the ignition flame does not exceed 25 seconds and does not produce drips that ignite the cotton wool. V2: Average combustion and/or smoldering after removing the ignition flame does not exceed 25 seconds, but produces drips that ignite the cotton wool. However, each sample requires that all test bars meet a particular V rating, or the sample is given the worst test bar rating. For example, one test bar is graded V2 and the other nine
If the book test bar is rated V0, the sample is rated V2. Reference example 1 Methacryloyl chloride 3.27 as a chain terminator
Polycarbonate produced using mol%. 2,2-bis-(4-hydroxyphenyl)-propane (bisphenol A) 3.192 Kg (14 mol),
One solution is made from 2.53 kg of aqueous sodium hydroxide solution with a concentration of 45% and 15 kg of distilled water. After adding 34 kg of methylene chloride, 52.2 g of methacryloyl chloride (approximately 0.5
mol) is added with stirring at room temperature. 20
Pass 2.64 kg of phosgene at a temperature of 25°C to 25°C. concentration
By adding an additional 26.3 kg of 6.5% sodium hydroxide solution, the PH value was adjusted to 13-14 during phosgenation.
to hold. Then add 15ml of triethylamine,
Stir the mixture for an additional 30 minutes. The upper aqueous phase is then separated off and the organic phase is pickled and washed free of electrolyte. Next, add methylene chloride to 300℃.
The organic phase is then distilled off via a ZSK machine, and the polycarbonate is made into granules. The relative melt viscosity is about 1.30 and the molecular weight is about 28,500. Reference example 2 Isopropenyl phenyl chlorocarbonate
Polycarbonate manufactured using 3.4 mol%. Production and finishing are carried out according to the method described in Reference Example 1 using 3.4 mol % of isopropenylphenyl chlorocarbonate. The relative solution viscosity is about 1.31 and the molecular weight is about 29,700. Reference Example 3 (Comparative Reference Example) Polycarbonate produced using 3.27 mol% of pt-butylphenol. The production and finishing were carried out according to the method described in Reference Example 1.
Performed using mole %. The relative solution viscosity is about 1.30 and the molecular weight is about 28,500. The polycarbonates from Reference Examples 1 to 3 were dissolved in methylene chloride and 1 or 2% by weight of benzophenone was added before the thickness of about 100 μm.
Processed into a film and dried overnight at approximately 120°C. Reference Example 4 The polycarbonate of Reference Example 1 was dissolved in methylene chloride, and 1% by weight of benzophenone based on the weight of the polycarbonate and 1.5% by weight of dibenzyl ether based on the weight of the polycarbonate were also added, and then the thickness Process into a film of approximately 100 μm and dry at approximately 120°C overnight. Example 1 The films from Reference Examples 1 to 4 were then exposed to a Philips HTQ ultraviolet lamp (high pressure mercury vapor lamp).
irradiate both sides for 45 and 180 seconds at a distance of 15 cm. The film is treated with methylene chloride, the crosslinked portion is separated as insoluble fibers or film pieces, and after drying, it is determined by gravimetric method. As a result of the different crosslinking of the polycarbonates from Reference Examples 1 to 4, the films undergo different stress cracking. For measurements, a strip 1 cm wide and 100 μ thick is bent into a ring with a radius of 3 cm, and the ring is immersed in carbon tetrachloride. The time required for the film ring to break as a result of stress cracking is recorded. The results are summarized in Table 1.

[Table] Reference Example 5 3916 g of the polycarbonate from Reference Example 1 was mixed with 80 g (2% by weight) of benzophenone and 4 g (0.1% by weight) of potassium perfluorobutanesulfonate.
and are mixed together in a twin-screw machine at 300°C, and the mixture is made into granules. Reference Example 6 3876 g of the polycarbonate from Reference Example 2 are mixed with 120 g of benzophenone and 4 g of potassium perfluorobutanesulfonate at 300° C. in a twin-screw machine and the mixture is made into granules. Reference Example 7 (Comparative Reference Example) 3876 g of the polycarbonate from Reference Example 3 was mixed with 120 g of benzophenone and 4 g of potassium perfluorobutanesulfonate at 300°C in a twin-screw machine, and the mixture was made into granules. shall be. Example 2 The polycarbonate granules from Reference Examples 5, 6 and 7 were injection molded to make standard test bars and tested using a Phillips HTQ 4 high pressure mercury vapor lamp.
Irradiate both sides of this rod for about 45 seconds at a distance of about 15 cm. Table 2 summarizes the classification of fire hazards found.

【table】

Claims (1)

Claims: 1 A compound of the general formula () having a molecular weight w (weight average) between about 10,000 and 200,000 and prepared using diphenol and a monofunctional chain terminator. In the formula, Z means a residue obtained by removing the hydroxyl group from diphenol, n means an integer from about 20 to 400, and E is in which m stands for 0 or 1, and R stands for H or _C1 - _C3 -alkyl. between 0.05 and 5% by weight of photoinitiator and optionally between 0.05 and 5% by weight of mesitylene, dibenzyl ether, benzoic acid benzyl ester, based on the weight of the polycarbonate;
polyglycol ether, aliphatic polyester,
A method for modifying polycarbonate, which comprises adding a compound having an unstable CH bond selected from tetrahydrofuran, dioxane, chloroform, toluene, xylene and CH ₂ Cl ₂ and then irradiating it with ultraviolet light. 2 The polycarbonate is treated with (a) between 0.05 and 5% by weight of a photoinitiator, based on the weight of the polycarbonate, and (b) optionally with between 0.05 and 5% by weight of labile C-H bonds, based on the weight of the polycarbonate. in a solvent mixture containing a compound of the invention and then irradiated with ultraviolet light, characterized in that the solvent is inert towards the polycarbonate. the method of. 3. Process according to claim 1, comprising spraying the polycarbonate with a solvent mixture containing a photoinitiator and optionally a compound with labile CH bonds. 4 having a molecular weight w (weight average) between about 10,000 and 200,000, prepared using diphenol and a monofunctional chain terminator, of the general formula () In the formula, Z means a residue obtained by removing the hydroxyl group from diphenol, n means an integer of about 20 to 400,
E is , in which m means 0 or 1, and R means H or C ₁ -C ₃ -alkyl. between 0.05 and 5% by weight of a photoinitiator, between 0.05 and 5% by weight of a flame retardant, based on the weight of the polycarbonate, and optionally between 0.05 and 5% by weight of a flame retardant, based on the weight of the polycarbonate. mesitylene, dibenzyl ether, benzoic acid benzyl ester, polyglycol ether, aliphatic polyester, tetrahydrofuran,
A method for modifying polycarbonate, which comprises adding a compound having an unstable CH bond selected from dioxane, chloroform, toluene, xylene and CH ₂ Cl ₂ and then irradiating it with ultraviolet light.