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    • 专利摘要:
    A METHOD FOR OBTAINING FORMABLE (CO) POLYMERS by continuous weight polymerization of methyl methacrylate or a mixture of methyl methacrylate with alkyl / meth / acrylate, taken in a ratio providing a copolymer containing at least 80% by weight of methyl methacrylate units, when heated in the presence of mercaptan and initiator free radical polymerization with subsequent removal of volatile substances and separation of the polymer, characterized in that, in order to increase the thermal stability of the polymers and their yield, as a free radical Initiator using an initiator with a half-life of B, h, at a polymerization temperature at a ratio of 10. . 10 3 / AB. 10 2.9 g A- (B + 10.3) -10 where A is the initiator concentration in mol / 100 g, the monomer mixture comprising the mercaptan, and O) is carried out at a constant temperature in the region of 130,160 & ° C, constant stirring and the content of the polymer in the reaction mixture F, wt.%, determined by the formula.
    公开号:SU1083912A3
    申请号:SU731960633
    申请日:1973-08-14
    公开日:1984-03-30
    发明作者:Симада Казуси；Маеда Тору；Нисизава Тамоту；Наризада Такехико；Анзаи Хисао；Сазаки Еситака
    申请人:Мицубиси Рэйон Компани Лимитед (Фирма)；
    IPC主号:
    专利说明:

    The invention relates to the production of moldable polymers.
    A method is known for producing formula Mbix (co) polymers by continuous bulk polymerization of methyl methacrylate or a mixture of methyl methacrylate with alkyl / meth / acrylate, taken in a ratio that provides a copolymer containing at least 80% by weight of methyl methacrylate units when heated to 120-170 ° C the presence of mercaptan and the initiator of free radical polymerization with the subsequent removal of volatile substances and the release of polymer 1.
    A disadvantage of the known method is the production of polymers with a low yield and thermal stability.
    The purpose of the invention is to increase the thermal stability of polymers and their yield.
    This goal is achieved by the fact that according to the method of obtaining formable (co) polymers by continuous bulk polymerization of methyl methacrylate or a mixture of methyl methacrylate with alkyl / meth / acrylate, taken in a ratio that provides a copolymer containing at least 80 wt.% Of methyl methacrylate units, heating in the presence of mercaptan and free radical initiator of polymerization with the subsequent removal of volatile substances and the release of the polymer, an initiator is used as a free radical initiator with a half-life. - a B in h at the temperature of polymerization when the ratio is:
    10 x A 10 3 AB 10
    2.9, A- (B + 10.3 IO-) where L is the initiator concentration in mol / 100 g of the monomer mixture comprising the mercaptan and the process is carried out at a constant temperature in the range of 130-160 ° C, constant stirring and the content of the polymer in the reaction mixture F, wt.% determined by the formula (0,01211-1,81), where T is the polymerization temperature, with
    Forming 1 s materials based on methacrylate polymer, obtained by the proposed method, are characterized by a degree of fluidity (the amount of output: in 1 gram of grams per 10 minutes, at a cylinder temperature under a load of 10 kg thereafter OGH.): 11l% by the letters FR) 0.5-75, especially 3-75 g / 10 min as measured in accordance with standard A S TM D 1238-65 T.
    Polymer-1x methacrylate moldings are widely used due to their excellent transparency, weather resistance, mechanical strength, heat resistance, resistance to chemicals and due to their other favorable properties molding materials suitable for pressing the product 1 of a complex profile, should have good pressing ability. In cases where the polymeric materials are reheated to transfer them to a molten state in order to perform molding or pressing, the molten polymer must have 5; However, molded materials that are highly fluid often result in pressed products with low heat resistance and with unsatisfactory mechanical characteristics.
    Extreme pressing conditions, such as high temperature, pressing less fluid materials or materials with good flowability for the manufacture of large-sized products, affect the quality of the finished products. Conducting an injection under undesirable severe conditions often results in products with a defect such as silver, or products with pores or discolored.
    The alkyl acrylates that can be used for copolymerization with methyl methacrylate are selected from the group consisting of alkyl acrylates containing from 1 to 18 carbon atoms in the alkyl unit and include, for example, methyl, ethyl, n-propyl, butyl, 2 -ethylhexyl-, dodecyl stearylacrylates. Alkylmethacry-. The lats used for copolymerization with methyl methacrylate are selected from the group consisting of alkyl methacrylates containing from 2 to 18 carbon atoms in the alkyl unit and include, for example, alkyl methacrylates, the alkyl units of which are different from the methyl group and are given above when considering suitable acrylates . Among these compounds, a homopolymer, i.e., polymethyl methacrylate and copolymers of methyl methacrylate with alkyl acrylate, selected from the group of methyl, ethyl ibutylacrylate, is used, because the polymerization activity of methyl methacrylate is different from polymethyl. The activity of other alkyl methacrylates and alkyl acrylates (if it is required to obtain a copolymer of a predetermined composition), the composition of the monomer loading must be constant, so that the product of the required composition can be obtained taking into account the relative indicators of the comonomer activity used. for example, in the case when methyl methacrylate is copolymerized with methyl acrylate or ethyl acrylate, the composition of the monomer loading should correspond to at least about 70% by weight of methyl methacrylate and JQ q0 30% by weight of methyl acrylate or ethyl acrylate. The proposed method includes two stages: polymerization and removal of volatile substances. At the stage of polymerization, the monomer charge consisting of the mI metacrype JJat is subjected to continuous block polymerization in one, two or more reactors, and it is recommended to use only one reactor, while at the stage of the removal of volatile compounds the volatile components consisting of unreacted monomers, and suitable additives can be added. A press material having the required characteristics was obtained. At the stage of polymerization, the loading of monomeric methyl methacrylate (which may contain one or more monomers) containing 0.01-1.0 molar percent of mercaptan and the above-mentioned amount of free radical catalyst is continuously introduced into the polymerization zone. Examples of suitable merchants that can be added to the monomer loading in the implementation of the proposed method include mercaptans containing from 3 to 18 carbon atoms; for example, primary aliphatic mercaptans, such as H-butyl, isobutyl-, n-octyl. N-dodecylmercaltans and the like; secondary 55
    aliphatic mercaptans, such as sec-butyl-, sec-dodecylmercaptans, etc .; tertiary aliphatic measures.
    Caltans, such as t-butylmercaptan and the like; aromatic mercaptans, such as phenylmercaptan, thiocresol, 4-tert-butyl-ortho-thiocresol, etc .;
    ethylene thioglycol; thioglycolic acid and its alkyl esters. These compounds may be used alone or in combination. Among these mercaptans, tert-butyl, n-butyl, n-octyl and n-dodecylmercaptans give the best results.
    Mercaptans are consumed in an amount of from 0.01 to 1.0 mol. % based on monomer loading.  With a dose of less than 0.01 mol. The polymerization rate increases abnormally and is subject to control, which makes it difficult to obtain products with a constant character, tert-butyl peroxate, 2,5-dimethyl-2, 5-di- (tert-butylperoxy) -hex. n, peroxide di-tert-amyl,, 5-diteristikami and excellent compressibility.  With a significant overdose of mercaptan, a polymer with a reduced degree of polymerization is formed, and the final products of a complex profile made from this press material have mechanical properties.  The recommended amount of mercaptan depends on the individual mercaptan used.  Thus, for example, in the case of n-dodecyl mercaptan, it is recommended to use an amount in the range between 0.1 and 0.2 mol percent, and in the case of tert butyl mercaptan, 0.2-0.45 mol percent.  The free radical initiation agent, which is used in accordance with the invention, is an initiation that satisfies the parameters of the above ratios, for example, a given half-life.  In carrying out the invention, free-radial initiation agents can be used, whose half-life at the reaction temperature is at least 0.001 h, and preferably at least PO2 H.  Examples of such free-for-all kalns agents initiating an are, for example, organic peroxides, such as di-tert-butyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, di-tert-butyl di-perphthalate, di-tert-bumethyl-2, 5-di-perphthalate (tert-butylperoxy) -hexine, and azo compounds, such as azobisisobutanol acetate, 1,1-azobiscyclohexanecarbonitrile, 2-phenyl-azo 2,4-dimethyl-4-methoxy-valeronitrile, 2-cyano-2-propylazoformaldehyde and t . P.  Free radical initiation agents - can be used both individually and in combinations, although they use separate initiating agents, since controlling the polymerization process is complicated when using two or more initiating agents.  From among the initiating agents mentioned above, ditert-butyl peroxide is preferred.  The amount of free radical initiating agent present in the monomer loading must be adjusted so that the symbol A, representing the concentration of free radical initiating agent in the monomer loading, expressed by the number of moles, of the initiating agent present in 100 g of the monomeric load, and the symbol B, which represents the half-life of the free-radical initiation agent at the polymerization temperature, satisfies the following ratios: 1 / -Z -.  -1оЗ, 5 3 / А В -10 In the case when the value of L - B exceeds 10, the compressibility of the product tends to deteriorate.  This value should not exceed 10, and preferably should not exceed 6.  In the event that the AB-10 value exceeds 3, undesirable adhesion of the polymer to the equipment used occurs, an acceptable agent is initiated and its concentration in the monomer loading is established so that this value does not exceed 2.5. It is recommended that A and B in addition, the following ratio was satisfied: 2.9: L-HC + 10.3 / -10 - (3) In this case, if the value of A (B + 10.3) 10 exceeds 2.9 ,.  there is a tendency to form by-products, in particular oligomers.  However, the presence of oligomers in the press material is undesirable.  This value is maintained at a level not higher than 2.9, and preferably at a level not lower than 2.0.  In addition, enjoy the limited.  a class of initiating agents possessing a relatively long half-life.  The individual concentration of the initiation agent in the monomer loading depends on the individual initiation agent and on the individual polymerization temperature.  However, the concentration of the initiating agent used in accordance with the invention is extremely low compared with the levels at which the same initiating agent is used in the earlier methods.  FIG.  Figure 1 shows the recommended concentration range of the initiation agent used in the proposed method; in fig.  2 and 3 is a schematic representation of the apparatus for carrying out the proposed method, variants.  FIG.  1 curves a, b and c correspond to equations 10 2, (B + 10.3).   WY, respectively, and each of these equations reflects the critical concentration described by each of these equations, of the initiating agent present in the monomeric load (expressed by the number of mol.  the initiation agent in 100 g of monomer loading) as a function of the half-life (h) of the initiation agent at the polymerization temperature.  Thus, any point of the shaded area. (FIG.  1) is a possible combination of the concentration of the initiation agent in the monomer loading and the half-life of the initiation agent that can be used in the practice of the invention.  The concentration of the free-radical initiation agent present in the monomer loading is preferably controlled in such a way that the following conditions are met: 10 (1) 2 AUV + 10.3 / Yu (2) 2 ,. 105 (3) The term half-life of a free-radical initiating agent at polymerization temperature means the half-life 110 of the initiating agent in a dilute solution from benzene, the temperature of which is maintained at the same temperature level as the polymerization temperature.  For example, the half life, for example, for di-tert-butyl peroxide and di-Humil peroxide is 1.0 and 0.23 hours, respectively, at 150 ° C.  In the polymerization zone, the reaction mixture to be polymerized, to which monomer per charge is continuously added at a selected constant rate, is thoroughly mixed and maintained at a temperature above 130 ° C, but below 160 ° C.  If the temperature of the reaction mixture (hereinafter referred to as the polymerization temperature) is significantly lower than it is difficult (to ensure uniform mixing and heat transfer due to the high viscosity of the polymerization reaction). It is difficult to control the polymerisation process and increase the conversion.  As the polymerization temperature increases, the reaction mixture becomes more fluid, but oligomers tend to form, the heat resistance and the compressibility of the product decrease, so the polymerization temperature is chosen. so that it is in the range between 130 ° C and 160 ° C, and preferably between 140 and 160 ° C, due to the fact that heat is generated in the reaction mixture resulting from the exothermic reaction and exposure, energetic stirring, the temperature of the reaction mixture should be maintained at –japaHee at a predetermined level by removing heat.  Temperature control by heat removal can be carried out by any of the known methods, including heat removal by heat transfer, from the cooled surfaces of the vessel in which the polymerization is carried out, using a shirt, chimneys, cooling pipes, etc. d.  or by feeding a cooled monomer charge, or by using other heat removal systems, such as using reflux cooling.  In the polymerization zone, the content of polymer φ in the reaction mixture (degree of conversion) is maintained, depending on the polymerization temperature, at that level. so that the following relationship holds: 70 (0.0121 T - 1.81) (4) in which the symbol t represents the polymerization temperature, C and is kept at a constant level.  In the case of continuous block polymerization of the type of complete mixing in order to obtain methacrylate polymers, while maintaining the degree of conversion at a high level, is performed by equation (4).  The requirement for a relatively high degree of conversion as well as the requirement for relatively limited initiating activity is fulfilled by using a small but certain amount of mercaptan and a set polymerization temperature in order to successfully use the rapid increase in the reaction rate associated with the so-called gel effect, without difficulties due to the uncontrolled flow of the polymerization process.  The proposed method can be easily controlled, whereby it is possible to obtain a stable product with stable characteristics over a long period of use, and during the course of the polymerization process there is no peak in the reaction heat generation curve.  A sufficiently high polymer yield based on the volume of the reactor can be achieved with minimal formation of by-products and without significant adhesion or deposition of the polymer on the details of the reactor.  Further, the process can be performed by npv using simple and inexpensive equipment.  In the case when the degree of conversion exceeds the critical value, 70 exp (0.0121 T-1.81), the required uniform mixing and heat transfer becomes difficult.  In cases where the conversion rate is 50% or less, it becomes difficult to fully utilize the rapid increase in reaction rate due. gel effect, which leads to the production of products containing unreacted monomers, which are present in relatively large quantities, which requires an increase in the cost of removing volatile products.  It is recommended to keep the value below the upper critical limit so that the difference is about a few percent.  The upper critical limits are, for example, 55.3% at 130 ° C; 62.4% at 70.3% at 150 ° C and 79.6% at 160 ° C.  A reactor that can be used in the practice of the invention can be a closed type reactor that is jacketed and suitable for stirring highly viscous materials with a stirrer. In one of the cases, one of the known types of reactors used in polymerization has a relatively elongated shape and designed to operate under conditions such that monomer loading can be introduced into the reactor from one end, and the polymerized mass can be removed from the other end, and in which the reaction liquid the bone is mixed in directions perpendicular to the axis of the reactor, but not in a direction parallel to the axis of the reactor, cannot be used in the practical implementation of the scientific research institute of the invention.  The polymerization process is carried out in a single reactor and the extracted material is fed from it to the reaction mass directly to the zone of the removal of volatile substances in order to remove these substances.  However, it is desirable that the reaction mixture extracted from the polymerization zone, in which the polymerization is carried out in accordance with the invention, may be further subjected to conditions causing the polymerization process to proceed before the volatile removal stage begins.  In the devolatilization step, the liquid reaction mixture can generally be heated to a temperature between 200 and 290 C under reduced pressure, thereby removing most of the volatile matter consisting essentially of unreacted monomers. .  The content of residual monomer in the final product is usually 1% by weight or less, preferably 0.3% by weight or less.  The isolated unreacted monomers 210 can be regenerated and monitored.  An apparatus that can be used to remove volatile substances is usually of the type named: vent extruder, devolator or worm-type extruder to remove volatile substances.  The polymer product from which volatiles are removed can be extruded (continuously extruded) in the molten state through a suitable die to produce desired pressings, the shape of which depends on the end use, for example tablets, flakes, crushed materials, pipes, tubes, rods, rods, sheets, etc. d.  To improve or to modify certain characteristics of press materials, the following additives can be introduced into them individually or in combination: plasticizers or lubricants, such as dioctyl phthalate, d-octyl sebacate, stearyl alcohol, stearic acid, lauryl alcohol; ultraviolet absorption agents such as tinavin P and methyl salicylate; coloring press materials, dyes and pigments and titanium dioxide; as well as polymers such as polystyrene and synthetic rubbers.  Additives are introduced at the polymerization stage, or at the volatile removal stage, or after the volatile removal stage.  In most cases, it is recommended to add additives after the polymerization step.  Press materials obtained by the proposed method are distinguished by excellent compressibility.  The latitude of the temperature range in which the resin can be pressed is a good criterion for assessing the compressibility of the resin.  The lower limit (T) of the temperature range depends mainly on the flowability of the resin and can be reduced by varying the average degree of polymerization, the amounts of comonomers used and the plasticizers used.  However, there is a practical limit to which the lower level of the pressing temperature can be lowered, since this simultaneously leads to a decrease in heat resistance, deterioration of mechanical characteristics, weather resistance and durability of the final extruded products to solvents.  On the other hand, the upper limit of the temperature range of the extrusion depends on the resistance of the resin to decomposition under the action of heat and on the content of volatile substances in the resin.  In order to increase the resistance to decomposition under the action of heat, the use of such methods as the addition of mercaptans to the monomer loading and copolymerization with is suggested. alkyl acrylates.  However, this does not necessarily give satisfactory results.  This problem remained unresolved and the del was to obtain polymers with extreme resistance to decomposition under the action of heat, containing a minimum amount of volatile substances, which would have made it possible to reach a sufficiently high upper limit of the temperature range of extrusion, since the lower limit of this interval can easily be reduced, As noted above, by using regulatory factors such as the degree of polymerization, the number of comonomers or plasticizers introduced hot  at the same time, a practically achievable limit appears.  The proposed method produces press materials that have a high resistance to decomposition under the action of heating, so that they have a high upper limit of the specified temperature range.  Press materials obtained in accordance with the invention, which have a wider range of compressibility, give a smaller number of pressed products with defects during pressing, which results in higher yields and productivity.  In addition, it is possible to successfully produce simultaneous pressing of products of relatively large and small dimensions if we use the press materials covered by the invention.  Monomeric loading (FIG.  2) is fed from tank 1 through valve 2 and pipe 3 to heat exchanger 6.  pipeline 5, and pumping is carried out by pump 4.  The monomer charge, subjected to conditioning in the heat exchanger 6, is then fed to the reactor 8 through the inlet -7.  The reactor is equipped with a stirrer 9 like a spiral tape, as well as a jacket 10 through which cooling fluid flows from the inlet 11 to the outlet 12 so that the reaction temperature inside the reactor is maintained at a predetermined level.  The reaction mixture is discharged from the reactor through conduit 13 and is fed via pump 14 via conduit 15 to the devolator 16, equipped with a screw 17, an outlet 18, a mouthpiece 20, heating devices 19 and an additive system 21.  The polymer freed from volatile substances is continuously squeezed out with a screw through a mouthpiece in the form of threads.  Volatile substances, mainly consisting of unreacted monomers, are made of a polymer, under reduced pressure, through an outlet, and regenerated.  Monomeric loading (FIG.  3) is supplied from the reserve 1, through the valve 2 and the pipeline 3 to the heat exchanger 6 through the pipeline 5 under the action of the inflation pump 4.  The heat exchanger b is of a closed type and is equipped with a cooling jacket and a turbine equipped with coils.  The monomer charge, subjected to conditioning in the heat exchanger 6, is fed through 7 to the first reactor 8 for carrying out polymerization in its upper part.  The first reactor 8 is equipped with a stirrer 9 like a spiral tape and a jacket 10 through which the cooling medium flows from the inlet 11 to the outlet 12.  The reaction mixture present in the reactor 8 is discharged through line 13 and flows to the second reactor 19 for polymerization, under the action of the pump 14, through line 16, through the heat exchanger 17 and line 18.  Heat exchanger 19 is of the type shown in the book Chemical Engineers Handbook, c.  1213, published by the publishing house MS.  Graw-Hill Book Co, and 1950, and in this heat exchanger the temperature of the reaction mixture is set at a predetermined level of 1-108.  The second reactor 19 for carrying out the polymerization process is equipped with a stirrer 20, similar to H, which is located in the first reactor 8 for carrying out the polymerization, and a cooling jacket 21 equipped with coils (not shown).  The reaction mixture discharged from the second polymerization reactor 19 passes through conduit 22, pump 23 and conduit 25 to an extrusion machine 27, in which the volatiles are removed, and is continuously extruded from extruder 27 through mouthpiece 28.  The extruder or machine is equipped with a screw 29, an outlet 30, devices for heating or cooling 31, and a system 37 for filling additives.  In the above operation example, valves 15, 24 and 25 are open 1, while valves 33, 35, 36 and 37 are closed.  With the valves 15 and 24 closed and the valves 33 and 35 closed, the reaction mixture from the first reactor 8 for carrying out the polymerization can be directly fed to the extruder 27 to remove volatile substances.  In another embodiment, when closing valves 33 and 35 and opening valves 15, 24, 36, 40 and 37, the reaction mixture from the second reactor 19 for carrying out the polymerization can be passed through the third reactor 44, for carrying out the polymerization it is also equipped with a mixer of 41 type. double helix and cooling jacket 42, In the experiments performed, the equipment was used (FIG.  2), which has the following characteristics: internal volume of the reactor — for carrying out the polymerization of a 300 l extruder (continuous extrusion machine) used as a finishing agent is of the type with double screws (diameter /: - 90 mm, length 1 200 mm ) with a lead-out area of 600 mm.  In the absence of specific indications, 0.1% by weight, based on the weight of the polymer, of stearyl alcohol is added to the product.  The deformation temperature of the product pressed from the product polymer was determined by the A S TM D648 / 56 method (test 1961), at a voltage of 264 psi. An inch (18216 n / mSH, at a heating rate of 35bF (minute: 14.6.7 C (minute).  The compressibility of the product polymer is determined as follows: this product polymer is processed by injection molding, carried out under the following conditions: The injection molding machine is supplied by the company.  Meiki Seisakusho, H-35A, piston type.  The volume of the mold 2 of the mold, 130 mm -130 mm-2 mm.  Pressure during casting 1200 kg / cm / 1200 10.  The time required to fill the molds 4 seconds per piston stroke.  Cycle pouring under pressure for 65 seconds.  A series of experiments with varying the temperature of the crucible was carried out.  In the experiments, the maximum temperature of the crucible T- is determined, at which the percentage of manufacture of defective pressed products with visible defects, bearing the name of silveriness, did not exceed 20%.  Example 1  Under conditions excluding contact with air, a monomer charge is prepared, essentially containing weight. h: methyl methacrylate, parts of methyl acrylate 13, 0. 23 n-octyl mercaptan and 0.0017 parts, t. e.  0.113 10 moles of initiation agent per 100 g of monomer loading (peroxide di-tert.  butyl) with a half-life of 1 h at 150 ° C, which is subjected to conditioning in a heat exchanger to a temperature of 30 ° C and is continuously fed into the reactor with. speed of 15 liters / h.  The excess internal pressure in the reactor created by nitrogen was 8 kg / cm (8-10 H / tf).  The polymerization temperature was set at 150 ° C.  After 7.8 hours, the feed rate of the load was increased to 25 liters / h and the process began to proceed in stationary conditions.  The reaction mixture in the reactor was thoroughly mixed using a ribbon spiral mixer rotating at 90 rpm.  During the steady state, the residence time of the mixture in the reactor was 4.7 hours and the reaction mixture, immediately after it left the reactor, contained 64% by weight of the polymer, as determined by gas-liquid chromatography.  The temperatures of the outlet section, the extruding section and the die of the extruder used with the outlet opening were, respectively
    respectively 250 ° C, 23UC and 225 ° C. Ab-; The salt pressure at the outlet section was maintained at about 9 mm Hg. The polymer was extruded in the form of bundles of threads through a mouthpiece, which had 4 round holes with a diameter of 3.785 (1/8 inch), was cooled with water and cut into 6.35 mm (1/4 inch) longplate. After 168 hours of continuous stationary work, 2.5 tons of compression tablets were obtained. The press material obtained in this way has an FR value of 36-40, and the percentage of residual methyl methacrylate and methyl acrylate, as measured by gas chromatography, was in both cases less than 0.1%. The press material was a general purpose methacrylate polymer with good properties, as indicated by an extremely high temperature T, was 295-300 ° C, the deformation temperature was 85 ° C, satisfactory mechanical characteristics and high transparency. After continuous work, no significant adhesion to the details of the equipment used was observed.
    PRI mme R 2. The experiment was carried out according to the general method given in Example 1; The monomer loading consists essentially of 98 parts of methyl methacrylate, 2 parts of methyl acrylate, 0.29 parts of tert, butylmercaptan, and 0.0017 parts, i.e. 0.116 mole of initiation agent per 100 g of monomer loading, di-tert peroxide. butyl (whose half life at 1.55 ° C was 0.55 h); The process is carried out as indicated in Example 1, with the exception that a polymerization temperature of 155 ° C is used, the residence time in the apparatus will be 4.1 hours, and the degree of conversion is 65%.
    The temperatures of the outlet section, extruding section and extruder die to remove volatile substances are 260 ° C., respectively. After 240 hours of uninterrupted stationary work, 3.6 tons of tablets are obtained for pressing.
    The press material thus obtained has a value of 7-8, the content of residual monomer co2 16
    Avit is less than 0.1%, the Tj value is in the range between 297 and, and the deformation temperature will be 103 C. After continuous operation, there is no significant adhesion of the polymer to the parts of the equipment used.
    Due to the fact that the methacrylate polymer usually begins to decompose rapidly at temperatures of about 310-340 ° C, it should be noted that the trial according to the values of T. polymeric press materials obtained by the proposed method have an unusually high resistance to decomposition under heating action;
    For comparison purposes, the values of T are determined for various formulated materials based on polymer methacrylate that are marketed and are related to both heat resistant and general purpose types. The results are placed in the table. one.
    Table 1
    Examples 3-13. The tests were carried out using the general method described in example 1, but the changes are made in the table below. 2. In table. 3 collected product specifications. In all experiments, no substantial adhesion of the polymer to the apparatus was observed.
    The products obtained in examples 1-7 have an average molecular weight of about 1100, and those obtained in examples 8-13 have an average molecular weight of about 1000. 398 Methyl2 A 0.35 0.0020 krilate 4100 is 0.93 0, 0022 588 methyl 12 C 1.0 0.0020 krylat 699 ethyl1 C 1.0 0.0017 krylat 793.5 methyl 1
    25 25
    25 25 0.074 n-dodecyl 0.27 0.076 tert-butyl 0.25 0.133 tert-butyl 0.35 0.116 tert-butyl, 0.30
    Notes: And dicumyl peroxide; B: 2,5-dimethyl-2,5-di (three-butyl peroxide) -hexin-3; C - peroxide di-tert, butyl; - number of moles of initiation agent per 100 g of monomer charge. Example 14. The process is carried out using the apparatus shown schematically in Fig. 3, B to the first and second reactors 8 and 21 for carrying out the polymerization, respectively, load 90 L and 14 ST l of the mixture, common of 98 parts of metal methacrylate, 2 parts of methyl acrylate and 0.28 parts of tert, butylmercaptan, respectively. The feedings initially introduced into these reactors are heated with stirring to 150 ° C. The excess internal pressure in each of the reactors and in the third reactor 56 was set at 8 kg / cm (8-10 n / m) using nitrogen. A monomer mixture containing 0.002 parts t, e, 0.1361 O mole per 100 g of monomeric mixture, ditertbutyl peroxide in addition to the same proportions as in the original mixture, methyl methacrylate, methyl acrylate and tert, butylmercaptan is conditioned to Achievements in the heat exchanger 6 and continuously fed to the first reactor for carrying out the polymerization 8 at a rate of 10 l / h, with retracement c. the same velocity of liquids from the first reactor 8 for carrying out the polymerization to the second reactor 21 for carrying out the polymerization and from the second reactor for carrying out the polymerization
    Continued table. 3 to the third reactor 56 for carrying out the polymerization, respectively. The temperature of the jacket of the third reactor 56 for carrying out the polymerization is maintained at 150 ° C. The reaction mixtures in the first and second reactors are used for sampling under pressure conditions, the pressure in the sample tanks is reduced and the samples are analyzed to determine the salinity of the polymer using the usual gas-liquid method. chromatography. After the polymer content in the reaction mixture from the first reactor reaches 50%, the flow rate of the reaction mixture in each of the pipelines is increased to 23 l / h. At the same time, the valve 54 is opened, the valve 55 is closed and the reaction mixture begins to flow pipeline 39 to extruder 40, in which the removal of volatile substances began. The temperatures of the outlet section, extruding and mixing sections and the mouthpiece are 275 ° С, 260 ° С and 255 ° С, respectively. The absolute pressure on the outlet section is maintained at about 15 mmHg. The viscous resin is expelled in the form of filaments through the mouthpiece, having the 1st four round holes with a diameter of 3.785 mm (1/8 inch). A continuous extrusion rate of 231 will be 15.5 kg of polymer per hour. The extruded filaments are cooled with water and cut in the form of tablets with a length of 6.35 mm (1/4 inch). The steady state of the reaction mixtures in the first and second reactors for carrying out the polymerization is maintained in such a way that the degree of conversion is respectively 53% at 150 ° C and 70% at 155 ° C, and the excess pressure is 8 kg / cm (8 10 n / m) The residence time of the reaction mixture in the first and second reactors is, respectively, 3.8 and 1.7 hours. After 480 hours of continuous operation, about 6 tons of resin are obtained. During this entire period of time, the process is stable. The polymer thus obtained has a value of 5.5-6.5, and the percentage of residual methyl methacrylate, measured by gas-liquid chromatography, turned out to be 0.2-1.0%. The polymer has excellent compressibility, has an extremely high temperature T, equal to 295-300 ° C, which is determined by the method of injection molding carried out and described above. The average degree of polymerization is about 1000, the strain temperature is 100-103 ° C, the polymer has satisfactory mechanical characteristics and high transparency and is completely colorless. All this shows that the product polymer has the desired combination of properties as a general purpose methacrylate press material. In one case, for some period of continuous operation, the valves 60 and 63 are open, whereby the initial charge accumulated in the reactor 56 is pumped 54 through line 59 to line 39 at a rate of 0.5 l / h. It does not indicate any significant effect on the characteristics of the polymer. The heat exchanger 45 is not used for cooling, but operates at an internal temperature maintained at 150 ° C. EXAMPLE 15 The experiment was carried out according to the general method described in Example 1, with a monomer loading, consisting of lice, of 100 parts of methyl methacrylate; 0.30 parts of tert.butylmercap224 tan and 0.0017 parts, i.e. 0.116 IO MOH per 100 g of monomer mixture, di-tert-butyl peroxide, subjected to continuous polymerization, with the exception that the reaction mixtures in the left and second polymerization reactors are maintained in such conditions that the conversion rate is respectively 52 and 68%. The residence time of the reaction mixture in these two reactors will be 5.5 and 2.0 hours, respectively. The polymer freed from volatiles is extruded at a rate of 15.0 kg / h. The polymer thus obtained has a FR value of 5.5-6.0; T - 295-299С, temperature of deformation from 101 to 104 ° С, average degree of polymerization about 1000 and percentage of residual methacrylate, equal to 0.2-0.1%. Examples 16-18. In each of these examples, the processes of polymerization and the subsequent removal of volatile substances are carried out in an apparatus used in Example 14, with the exception that the first reactor 8 for carrying out the polymerization was used as Only one operating reactor for carrying out the polymerization, and that the reaction mixture from reactor 8 was pumped 52 directly to an extruder 40, which serves to remove volatile substances. The polymerization temperature is 150 ° C, and the feed rate of the monomer mixture is 23 l / h. As in Example 16, the monomer charge, as used during the steady state stage, consists of 100 parts of methyl methacrylate; 0,0017 parts, i.e. 0.116-10 mol per 100 g of the monomer mixture, di-tert-butyl peroxide and 0.29 parts of tert-butyl mercaptan. The reaction mixture present in the reactor 8 is thoroughly mixed and the conditions are maintained at such a level that the polymer content is 52%. In Example 17, the monomer charge. During the steady state is a mixture of 100 parts of methyl methacrylate; 0,0014 parts, i.e. 0.095 mol per 100 g of monomeric mixture of di-tert-butyl peroxide and 0.30 part of tert-butyl mercaptan. 25108391 The conversion is maintained at 55%. In Example 18, the monomer charge consists of 90 parts of methyl methacrylate; 10 parts of methyl acrylate; 0,0014 5 parts, i.e. 0,094-U mol per 100 g of the monomer mixture, peroxide di-tert. butyl and 0.36 part of tert-butyl mercaptan at the steady state stage. The content of polymer in the reaction mixture is 65%. In each experiment, during continuous operation during the week, satisfactory products are obtained with an average degree of polymerization equal to 15 to about 1000. Some characteristics of the products are placed in the table. four.
    Note. x1 P: average degree of polymer polymerization;
    x2 HDT: warp temperature;
    x3 EA: etshtakrilat;
    x4 VA: butyl acrylate;
    x5 MA: methyl acrylate;
    x6 TVM: tert.butylmercaptan;
    x7 DM: n-dodecyl mercaptan;
    x8 VM: n-butyl mercaptan;
    x9 OM n-octyl mercaptan.
    Comparative gain of 100 parts of methylmethacryl e p 1. Experience is carried out using the general principle; 0.31 parts of t-butyl mercaptan
    by the method described in example 1, and 0.1 parts of peroxide di-tert. butyl
    use monomer loading, co-life with a half-life of 2.4 hours at 140 ° C, from the table below. Table 4 Examples 19 to 24. In each of these examples, the experiment described in example 14 is repeated; indicated changes. Special conditions and the results obtained are collected in l. 5. t a b l and c a 5 271 i. 6.85-16 moles of initiation agent per 100 g of monomer loading, the process is carried out in such a way that the polymerization temperature is 140% and the degree of conversion is 30%. Meanwhile, the extruder portion of the extruding portion and the extruder die, which serves to remove volatiles, are 275 ° C, respectively. 245С and 235С. The press material obtained by the reader has a value of 6–8, a deformation temperature of 96–99 ° C and a T value of 270 ° C. After 6 hours of continuous work, some adhesion of the polymer to the parts of the equipment used was observed. Comparative Example 2. When used as a container for polymerization, an extruder with a double screw, having two screws with a diameter of 8.5 inches (215.9 mm) and a length of 9 inches (224.46 mm) monomer loading consisting of 100 parts of methyl methacrylate, 0.225 parts of di-tert-butyl peroxide with a half-life of 0.49 at 157 ° C, i.e. 1 5.4 10 moles of initiation agent per 100 g of monomer loading and 0.35 part laursht2 mercaptan. The monomer charge is fed to the extruder hopper at a speed of 82 g / minute and the reaction mixture is discharged from the extruder and continuously fed to the apparatus to remove volatile substances. The temperature in the extruder will be 157 ° C., The residence time in the extruder is 25 minutes, and the degree of conversion over this period is 93%. The temperature of the volatile removal apparatus is 260 ° C. The polymer that is discharged from this apparatus is cooled and tableted. The percentage of residual methyl methacrylate in tablets reaches as high as 1.4% by weight. Part of this high percentage of residual methyl methacrylate is caused by the thermal decomposition of the polymer in the apparatus. The value of 1 obtained tablets is in the range between 245 and 255 C when measured by the method of injection molding, which indicates the poor compressibility of this molded material. Thus, the invention makes it possible to obtain a methyl methacrylate copolymer in high yield and thermal stability.
    S 7
    /;
    Th
    0- / 1BV JV Z
    fig.Z. 25
    权利要求:
    Claims (2)
    [1]
    METHOD FOR PRODUCING FORMABLE (CO) POLYMERS by continuous polymerization in bulk of methyl methacrylate or a mixture of methyl methacrylate with alkyl / meth / acrylate, taken in a ratio providing a copolymer containing at least 80 wt.% Methyl methacrylate units by heating
    Figure 1, in the presence of mercaptan and an initiator of free radical polymerization followed by the removal of volatile substances and the isolation of the polymer, characterized in that, in order to increase the thermal stability of the polymers and their yield, an initiator with a half-life of V, h, is used as a free radical initiator the polymerization temperature when the ratio
    10> z A 1.2 V ' 1.1 . 10 3 3 '/ AB 10 5
    [2]
    2.9} A * 1 (B + 10.3) -10 ' 6 where A is the initiator concentration in mol / 100 g, the monomer mixture including mercaptan, and the process is carried out at a constant temperature in the region of 130-160 ° C, constant stirring and polymer content in the reaction mixture Ф, wt.%, Determined by the formula 50 <Ф <70, exp; (0.0121 T - 1.81) where T is the polymerization temperature ° C
    SU <„, 1083912 t
    1 1083912
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    同族专利:
    公开号 | 公开日
    JPS4937993A|1974-04-09|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    JPS5490284A|1977-12-27|1979-07-17|Mitsubishi Chem Ind Ltd|Production of methyl methacrylate polymer|
    JPH0225481B2|1981-11-24|1990-06-04|Mitsubishi Rayon Co|
    DE3818658C2|1988-06-01|1990-10-11|Peters Maschinenfabrik Gmbh, 2000 Hamburg, De|
    JP3628518B2|1998-07-14|2005-03-16|三菱レイヨン株式会社|Methacrylic polymer and process for producing the same|
    JP5958577B2|2015-02-27|2016-08-02|三菱レイヨン株式会社|Method for producing methacrylic resin|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    JP8113872A|JPS4937993A|1972-08-15|1972-08-15|
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