POLYCARBONATE MOLDING MASSES WITH GOOD DEMOLITION AND
MOLDED BODIES MANUFACTURED FROM THEMSELVES AND
SEMI-LABORED PRODUCTS WITH GOOD PROPERTIES
GLIDE. Field of the invention. The object of the present invention are polycarbonate molding compositions. adjusted in a perfectly demolding manner, with esters of fatty acids based on 1,2-d? h? drox? propane and carboxylic acids with 1 to 40 carbon atoms as demolding agents, if necessary in addition other usual additives for carbonate Description of the prior art. Patents and publications are known that disclose the elect release of additives in thermoplastics in general and, especially, in polycarbonate The substances used in a more frequent way as agents for demolding are the esters of the long chain and acid alcohols For example, the use of alcohol esters with fatty acids or polyols such as, for example, pentaeptpta with fatty acids, as disclosed in DE 33 12 158, EP 100 918, EP 103 107, EP, will be cited here.
561 629. EP 352 458, EP 436 117, or when Guerbet alcohols have been used in US 5 001 180, DE 33 12 157, US 5 744 626 and when mountain oils are used as acidic components, in the US 4 097 435 It is a disadvantage that the fatty acid esters show a clear release effect only from amounts greater than 0.5% by weight. These concentrations lead, however, often to a turbidity and / or a Formation of deposits on the molds REF. 134353 Other demolding agents, such as, for example, long-chain ketones, have a tendency, by self-condensation, to form chromophores and are difficult to access (EP 100 918). Likewise, siloxanes (US 4 536 590, US 4 390 651, US 3 751 519) are used, which have a sufficient stability at temperature but which, however, have a very poor compatibility with polycarbonate and lead, at concentrations necessary for its activity, to undesirable turbulence, which greatly limits the possibilities of application of a material, such as polycarbonate, which is basically used for transparent finishes. The α-olefin polymers described, for example, in EP-A-561 630 and in EP-A-230 015, optionally with remaining double bonds (DE-A-32 44 499) are not stable to color . In the case of the long-chain alkanes (US 4 415 696), a problem of compatibility with polycarbonate is raised in hydrogenated systems, which leads to mold parts that are too turbid and, therefore, not transparent . In addition, the waxy or liquid-waxy consistency of these products constitutes an impediment. The demolition, without tools, of molded parts of polycarbonate, with maintenance of the surface of great quality, depending on the configuration of the molded part, which is frequently very diverse, due to the fact that short times are required, constitutes a permanent challenge. for the cycle and high transformation temperatures. Many problems can often be overcome only with a temperature for the particular demolding. There is therefore a permanent need for new potentially release agents. During the demolding process, two forces act, friction by adhesion and friction by sliding. Thus, the agent for demolding must be configured in such a way that both forces are minimized without harmful formation of deposits on the molds. Detailed description of the invention. The task was therefore to find mold release agents that minimized both demolding forces to the same extent to enable a molding compound to be capable of demolding all finished partial geometries without the formation of deposits on the molds. In addition, there was the task of finding agents for demoulding that had no tendency to transesterification with polycarbonate and that do not conduct, at active concentrations, at turbidity or at colorings. Another task is to avoid the problem due to the adhesion of the molded parts, finished, of polycarbonate, such as that which occurs, for example, when cups are separated after storage. Another task is to avoid the problem due to the adherence of the molded parts, finished, of polycarbonate on metals, such as that which occurs, for example, when sliding on inclined metal planes. Another task is to control the knotting force, which is important, for example, in the case of toys. In this case, a good tuning of the components must be taken into consideration, since too small a knotting force is also undesirable for some applications. The task was solved by the use of esters of fatty acids based on 1,2-dihydroxypropane and carboxylic acids with 1 to 40 carbon atoms as demolding agents, which have a sufficient solubility and stability in the polycarbonate. The object of the present invention are polycarbonate molding compositions 4 with a content of 0.005 to 5.0% by weight, preferably 0.05 to 3.0% by weight, most preferably 0 , 15 to 2.0% by weight of esters of fatty acids based on 1,2-dihydroxypropane and acids with 1 to 40 carbon atoms as well as esters of 1,2-dihydroxypropane with mixtures of various carboxylic acids with 1 to 40 carbon atoms, the alcohol also being partially esterified, as well as mixtures consisting of partially esterified and fully esterified products and, if appropriate, using other usual additives in polycarbonate, such as, for example, thermostabilizers, anti-UV stabilizers, other release agents, flame retardants, anti-drip agents, fillers, glass fibers and mixing components such as ABS, ASA, SAN, EPDM or polyesters based on terephthalic acid and diols, ca characterized in that the molding compositions provide a tool for measuring the demolding forces (tool for measuring the coefficient of friction) for frictional friction friction friction, sliding coefficients of, preferably, <0.80, particularly preferably < 0.60 and, very particularly preferably, < 0.40, having a value between 0.85 and 1.50 the reference value of an agent-free polycarbonate for demolding with the same viscosity, measured in the tool for the coefficient of friction. The molding compositions according to the invention can be contaminated with impurities containing the individual constituents of the molding composition, which derives from their synthesis, processing, processing and storage, as well as contaminations that occur during the manufacture or transformation of the compositions. of molding according to the invention. However, the objective is to work with products as clean as possible. It is preferred that, when the molding compositions contain free OH groups, they contain less than 10 ppm of ions, more preferably less than 5 ppm. In a very particularly preferred manner this is valid for the ions of the elements Na, K, Mg, Ca, Sn, Ti, Fe, Ni, Cr. It is preferred, when the esters of the fatty acids, to be used according to the invention , are partially esterified and contain free OH groups, containing less than 10 ppm of ions, more preferably less than 5 ppm. This is especially true for the ions of the elements Na, K, Mg, Ca, Sn, Ti, Fe, Ni, Cr. The adhesion of the finished polycarbonate moldings is preferably reduced by means of a content of 1.5% by weight up to 2.5% by weight of mold release agent. The esters of the fatty acids according to the invention are commercially available. In the sense of the present invention, the aromatic polycarbonates, thermoplastics, are both homopolycarbonates and also copolycarbonates; the polycarbonates can be linear or can be branched in a known manner.
A part, up to 80% by mole, preferably from 20% by mole to 50% by mole of the carbonate groups in the polycarbonates, suitable according to the invention, can be replaced by aromatic groups of esters of dicarboxylic acids. Such polycarbonates, which contain both acidic residues of the carbonic acid and also acidic residues of the aromatic dicarboxylic acids incorporated in the molecule chain, are exactly named aromatic polyester carbonates. In the present application, "
they will group, in order to simplify, under the expression of aromatic polycarbonates, thermoplastics. The preparation of the polycarbonates, to be used according to the invention, is carried out in a known manner from diphenols, carbamic acid derivatives, optionally chain terminators and, optionally, branching agents, by replacing a part of the carbonic acid derivatives by aromatic dicarboxylic acids or by dicarboxylic acid derivatives for the preparation of the polyester carbonates and, in particular, according to the amount of the carbonate structural units to be replaced in the aromatic polycarbonates by structural units of esters of aromatic dicarboxylic acids. The details regarding the obtaining of polycarbonates have been described in hundreds of patent descriptions for approximately 40 years. By way of example, references will be made to the publications • Schnell, "Chemistry and Physics of Polycarbonates", Polymer Reviews, Volume 9, Interscience Publishers, New York, London, Sydney 1964; • D.C. Prevorsek, B.T. Debona and Y. Kesten, Corporate Research Center, Allied Chemical Corporation, Morristown, New Jersey 07960: "Synthesis of Poly (ester Carbonate) Copolymers", in Journal of Polymer Science, Polymer Chemistry Edition, Vol. 19, 75-90 (1980 ) "; • D. Freitag, U.Grigo, PR Müller, N. Nouvertne ', BAYER AG," Polycarbonates "in Encyclopedia of Polymer Science and Engineering, Volume 1 1, Second Edition, 1988, pages 648-718 and finally • Dr. U. Grigo, K. Kircher and P. R- H. Müller "Polycarbonate" in Becker / Braun, Kunststoff-Handbuch, Volume 3/1, Polycarbonate, Polyacetale, Polyester, Celluloseester, Carl Hanser Verlag München, Vienna 1992,
pages 117-299. Thermoplastic polycarbonates, including thermoplastic aromatic polyester carbonates, have average molecular weights M * (determined with the aid of the measurement of the relative viscosity at 25 ° C in CH2CI: and at a concentration of 0.5 g per 100 ml of CH2Cl2) from 12,000 to 120,000, preferably from 15,000 to 80,000 and, especially, from 22,000 to 60,000. The diphenols suitable for the preparation of the polycarbonates to be used according to the invention are, for example, hydroquinone, resorcinol, dihydroxydiphenyl, bis- (hydroxyphenyl) -alkanes, bis (hydroxyphenyl) -cycloalkanes, bis- (hydroxy) - phenyl) -sulfides, bis- (hydroxyphenyl) -ethers, bis- (hydroxyphenyl) -ketones, bis- (hydroxy-phenyl) -sulfones, bis- (hydroxyphenyl) -sulphoxides, a, a'-bis- (hydroxyphenyl) -diiso-propylbenzenes, as well as their alkylated compounds in the nucleus and halogenated in the nucleus. Preferred diphenols are 4,4'-dihydroxydiphenyl, 2,2-bis- (4-hydroxy-phenyl) -l-phenylpropane, 1,1-bis- (4-hydroxyphenyl) -phenyl-ethane, 2,2-bis- (4-hydroxy-phenyl) propane, 2,4-bis- (4-hydroxyphenyl) -2-methylbutane, 1,1-bis- (4-hydroxyphenyl) - m / p diisopropylbenzene , 2,2-bis- (3-methyl-4-hydroxyphenyl) -propane, bis- (3,5-dimethyl-4-hydroxyphenyl) -methane, 2,2-bis- (3,5-dimethyl) -4-hydroxyphenyl) -propane, bis- (3,5-dimethyl-4-hydroxyphenyl) -sulfone, 2,4-bis- (3,5-dimethyl-4-hydroxyphenyl) -2-methylbutane, , l-bis- (3,5-dimethyl-4-hydroxyphenyl) -m / p-diisopropyl-benzene, 2,2- and l, l-bis- (4-hydroxyphenyl) -3,3,5- trimethylcyclohexane. Particularly preferred diphenols are 4,4'-dihydroxydiphenyl, 1,1-bis- (4-hydroxyphenyl) -phenyl-ethane, 2,2-bis- (4-hydroxyphenyl) -propane, 2,2- bis- (3,5-dimethyl-4-hydroxyphenyl) -propane, 1,1-bis- (4-hydroxyphenyl) -cyclohexane and 1,1-bis-
(4-hydroxyphenyl) -3,3,5-trimethylcyclohexane These and other suitable diphenols are described, for example, in US Pat. Nos. 3 028 635, US-PS-2 999 835, US-PS-3 148 172 , US-PS-2 991 273. US-PS-3 271 367, US-PS-4 982 014 and US-PS-2 999 846, in the description of the German patent applications, published, not examined DE- A 1 570 703, DE-A-2 063 050, DE-A-2 036 052, DE-A-2 211 956 and DE-A-3 832 396 in the specification of the French patent FR-A 1 561 518 , in the monograph "H. Schnell, Chemistry and Physics of Polycarbonates, Interscience Publishers, New York 1964", as well as in the descriptive reports of Japanese patent applications published, not examined, 62039/1986, 62040/1986 and 105550 / 1986 In the case of homopolycarbonates, only one diphenol is used, in the case of copolycarbonates, several diphenols are used, obviously the bisphenols used being contaminated, as well as all the chemical products and auxiliary products, added to the synthesis, with impurities from their own synthesis, even when it is desirable to work with raw materials as clean as possible. Suitable chain breakers are both monophenols and also monocarboxylic acids. Suitable monophenols are phenol, alkylphenoles, such as cresols, p-tert-butylphenol, pn-octylphenol, p-iso-octylphenol, pn-nonylphenol and p-iso-nonylphenol, halogenphenols such as p-chlorophenol, 2, 4-dichlorophenol, p-bromophenol and 2,4,6-tribromophenol, or mixtures thereof. Suitable monocarboxylic acids are benzoic acid, alkyl benzoic acids and halogenobenzoic acids. Preferred chain terminators are the phenols of the formula (I) P6 -Ph-OH (I) in which R6 denotes H or a branched or unbranched alkyl radical having 1 to 18 carbon atoms. The amount used of the chain switches is from 0.5 mol% to 10 mol%, based on the moles of the diphenols used in each case. The addition of the chain switches can be carried out before, during or after phosgenation. Suitable binders are trifunctional compounds or with a functionality greater than 3, known in the chemistry of polycarbonates, especially those with three or more than three phenolic OH groups. Suitable branching agents are, for example, phloroglucin, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptene, 2,4,6-dimethyl-2, 4,6-tri- (4 -hydroxyphenyl) -heptane, 1, 3,5-tri- (4-hydroxyphenyl) -benzene, 1,1-tri- (4-hydroxyphenyl) -ethane, tri- (4-hydroxy-phenyl) -phenyl-methane, 2,2-bis- [4,4-bis- (4-hydroxyphenyl) -cyclohexyl] -propane, 2,4-bis- (4-hydroxyphenyl-isopropyl) -phenol, 2,6-bis- (2-hydroxy) -5'-methyl-benzyl) -4-methylphenol, 2- (4-hydroxyphenyl) -2- (2,4-dihydroxyphenyl) -propane, esters of hexa- (4- (4-hydroxy-phenyl-isopropyl) phenyl) -ortoterephthalic, tetra- (4-hydroxyphenyl) -methane, tetra- (4- (4-hydro-xyphenyl-isopropyl) -phenoxy) -methane and 1,4-bis (4 ', 4"-dihydroxy-triphenyl) ) -methyl) -benzene as well as 2,4-dihydroxybenzoic acid, trimesyl acid, cyanuryl chloride and 3,3-bis- (3-methyl-4-hydroxyphenyl) -2-oxo-2,3- The amount of the branching agents, used if necessary, amounts from 0.05 mol% to 2.5 mol%, referred in turn to the moles of the dif noles employees in each case. The branching agents can be arranged with the diphenols and with the chain switches in the aqueous, alkaline phase, or they can be added before the -10-phosgenation is dissolved in an organic solvent. The measures for obtaining the polycarbonates are known to the person skilled in the art. The aromatic dicarboxylic acids suitable for the preparation of the polyester carbonates are, for example, phthalic acid, terephthalic acid, isophthalic acid, tert-butyl isooctonic acid, 3,3'-diphenyldicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4 acid. -benzophenone-dicarboxylic acid, 3,4'-benzophen-nadicarboxylic acid, 4,4'-diphenylethericarboxylic acid, 4,4'-diphenylsulfone-dicarboxylic acid, 2,2-bis- (4-carboxyphenyl) -propane, trimethyl-3-phenylindan-4,5'-dicarboxylic acid . Particularly preferred aromatic dicarboxylic acids are terephthalic acid and / or isophthalic acid. The dicarboxylic acid derivatives are dicarbonyl dihalides and dialkyl dicarboxylates, especially dicarbonyl dichlorides and dimethyl dicarboxylates. The replacement of the carbonate groups by the aromatic groups of dicarboxylic acid esters is carried out essentially in a stoichiometric and also in a quantitative manner such that the molar proportion of the reaction participants is also reflected in the finished polyester carbonate. The incorporation of the aromatic groups of the esters of the dicarboxylic acids can be carried out both statistically and in the form of blocks. Preferred forms for the preparation of the polyester carbonates, to be used according to the invention, including the polyester carbonates, are the known process at the boundary surface and the known process of melt transesterification. In the first case the phosgene preferably serves as a carbonic acid derivative, in the latter case, preferably, the diphenyl carbonate. The catalysts, the solvents, the preparation, the reaction conditions, etc. for the preparation of the polycarbonates have been sufficiently described and are known in both cases. The preparation of the molding compositions according to the invention by the addition of the alkanes according to the invention, during the synthesis, in the melting, or in the case of the process of the boundary surface between the phases, in a processing or concentration stage , as well as in solution, is carried out by combining the polycarbonates, dissolved in a solvent for polycarbonates, simultaneously or successively with the alkanes according to the invention, if necessary, with other additives and then removed by evaporation the solvent for polycarbonates. The object of the present invention is, therefore, also a process for obtaining the polycarbonate molding compositions according to the invention, characterized in that the polycarbonates are mixed with the esters according to the invention either simultaneously or successively, either in or in solution, and then the mixture is kneaded in a melt either at temperatures between 260 ° C and 450 ° C, preferably between 260 ° C to 420 ° C and, very particularly preferably, from 260 ° C. up to 360 ° C, or it is extruded in melting at temperatures between 250 ° C and 320 ° C, or the polycarbonate solutions are concentrated by evaporation and the obtained mixture is granulated. The polycarbonate molding compositions according to the invention can also contain the usual additives, such as glass fibers, fillers, pigments, UV stabilizers, thermostabilizers, antioxidants, flameproofing agents, resilience modifiers and, in case given, other agents for demolding, in the usual amounts for the thermoplastic polycarbonates. Suitable glass fibers are all varieties and types of glass fiber obtainable in commerce, ie glass varieties cut from long glass fibers (chopped strands) and short glass (milled fibers), as long as they have been treated so that they are compatible with polycarbonate by suitable sizes. The glass fibers, used for the manufacture of the molding compounds, are manufactured from glass E. E glass according to DIN 1259 is an aluminum-borosilicate glass with an alkaline oxide content below of 1% by weight. Usually glass fibers with a diameter from 8 to 20 μm, and with a length from 3 to 6 mm (chopped strands) will be used. You can also use short glass (milled fibers), as well as suitable glass spheres.
Flame-retardant agents, such as those which are used, for example, in polycarbonates and which can also be used in the molding compositions according to the invention, are alkali metal salts of organic and inorganic acids, especially sulfonic acids, such as, for example, sodium or potassium perfluorobutane sulphonate, potassium hexafluoroaluminate, sodium hexafluoroaluminate, potassium diphenylsulfone sulphonate, sodium 2-formylbenzenesulfonate, (sodium N-benzenesulfonylbenzenesulfonamide, often in combination with other protective agents against the flame, such as halogenated organic compounds, such as, for example, tetrabromo oligocarbonate, cryolite and
Í- -13-Teflon. Mixtures of the additives mentioned are also suitable. These usual additives can be added to the polycarbonates, which are finished in a flame retardant manner, together with the components according to the invention or thereafter. The polycarbonate molding compositions according to the invention can be converted into customary processing machines, according to known methods, under the usual transformation parameters for polycarbonates, to form moldings. Transforming by injection is preferred. Thus, the object of the invention are also the parts manufactured from the molding compositions according to the invention, such as molded parts and semi-finished products. Molded parts find application, for example, in the electrical, electronic, lighting, computer, construction, automotive and / or aircraft sectors as well as in the packaging, food and beverage industry. The toy shop. The molding compositions are suitable for injection-molded articles and extruded articles, such as, for example, sheets, cups, plates, plates with hollow chambers, lamps, housings for electrical appliances, computers or equipment for motor vehicles such as glazing, parts for the dashboard, deflectors, coatings and the like or toys. The release properties of the polycarbonate molding compositions according to the invention and the comparative examples of the state of the art have been measured in a tool for measuring the demolding forces (tool for measuring the friction coefficients) . The coefficients of friction for the friction by adherence and for the sliding friction have been determined, which represent a magnitude for the forces of demolding for the adherence and the sliding of the mold from the tool of casting by injection. A molded piece in the form of a plate with a mass temperature of 300 ° C and a tool temperature of 90 ° C is injected. The molded part is rotated through an angle of 90 °, after cooling for 20 seconds in the closed tool. A system for the detection of the procedure data measures the starting moment of the plate and the compression force of the tool punch on the plate. The coefficients are determined from the measurement parameters. Examples The quantitative indications in the examples, expressed in% by weight, refer to the weight of the whole mixture. Examples 1 to 4, and comparative examples 1 to 4. An aromatic polycarbonate consisting of 2,2-bis- (4-hydroxyphenyl) -propane (melt index 10, measured according to DIN 53 735) was melted with phenol as a switch of the chains, at 300 ° C in a double-shaft extruder (ZSK 32/2) with gasification under vacuum. The amounts of the ester according to the invention, indicated in the examples, were then metered directly into the polycarbonate melt. The polycarbonate bar was cooled in the water bath and then granulated. The granulate was dried in the cabinet for vacuum drying at 120 ° C for 8 hours and injected into an injection molding machine with a mass temperature of 300 ° C and a tool temperature of 90 ° C. to give specimens with the dimensions 60 mm x 40 mm x 4 mm thick. Characteristic optical data such as these were measured on the sample plates.
as transmission and turbidity. The coefficients of friction were measured with the help of a specially manufactured measuring tool. In all the tests, the same plate-shaped molded part was always injected at a mold temperature of 90 ° C in an Arburg Allrounder 320-210-850-D type injection molding machine at a temperature in the mass of 300 ° C. The molded part is rotated through an angle of 90 °, after cooling for 20 seconds in the closed tool. A system for the detection of the procedure data measures the starting moment of the plate and the compression force of the tool punch on the plate. The coefficients are determined from the parameters of the measurement. The coefficients for friction by adhesion and for friction by sliding is taken as a magnitude for the release effect. Thus, low values are advantageous compared to high values. Examples 1 and 2, as well as comparative examples 1 to 3 have been indicated in Table 1. For comparison, a polycarbonate free of mold release agent and a polycarbonate containing pentaerythritol tetrastearate = PETS were used. The molding compositions according to the invention are characterized by significantly lower coefficients of friction and are already active at lower amounts than the standard release agent, PETS, usually used. The molding compositions according to the invention were subjected to a slip test of molded parts on castings. For the test, cups were made by injection casting. Two cups were inserted, without force, and after 1 hour they were detached. The cups, made from the molding compositions according to the invention,
(examples 1 and 2), could be detached without adhesion. In the case of the cups constituted by the molding compositions of comparative examples 1, 2 and 3, adhesion effects were observed. Table 1.
- = Great grip, poor slip, + slight grip, moderate slip, + + = almost no grip, good slip, + + + = no grip, very good slip. The molding compositions according to the invention have a lower turbidity and a better transmission (examples 3 and 4) than the comparative example 4 (see table 2), even at higher contents in demolding agents.
Table 2
It is noted that, with regard to this date, the best method known to the applicant, to carry out the aforementioned invention, is that which is clear from the present description of the invention.