JPS5948121A - Continuous manufacture of extruded sheet - Google Patents

Abstract

PURPOSE:To continuously produce the methacrylate polymer extruded sheet with excellent resistance to heat decomposition and uniform quality by a method wherein mixture of radical polymerization initiator and monomers containing mercaptan is continuously bulk-polymerized and, after volatile matters therein being removed by separation, molded by extrusion and rolling. CONSTITUTION:The monomer mixture containing methyl methacrylate, alkyl acrylate or alkyl methacrylate (excluding methyl methacrylate), 0.01-10wt% mercaptan, and the radical polymerization initiator, the amount of which satisfies the formulae described here, is continuously fed to a reactor. Polymerization is performed while the reaction mixture being uniformly mixed by stirring at a temperature in the range of 130-200 deg.C and at the same time the viscosity of the reaction mixture being maintained at a fixed value in the range of 10-500 poises. After that, the reaction mixture is continuously taken out of the reactor and yet the polymer and the unreacted monomer are separated from each other at a volatile eliminating extruder. Finally, the separated polymer is extruded from the extruder die in order to be formed in a sheet. Di-tert-butyl peroxide or the like is employed as the radical polymerization initiator.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous method for producing extruded plates, and more particularly to a method for continuously producing extruded plates from a sliding body in a methyl methacrylate system.

Conventionally, thermoplastic resin extrusion plates are produced by suspension polymerizing a vinyl monopropylene to produce a polymer, and then melting and extruding the obtained polymer from an extruder equipped with a die. A method is adopted in which the material is formed into a plate-like body using rolls or the like.

Such a method has the advantage that various thermoplastic polymers can be extruded into desired plate-shaped products as long as the extrusion molding method is available.

However, since the thermoplastic polymer to be subjected to extrusion molding in the above production method is mainly produced by a suspension polymerization method using a water-fired medium, dispersants used in the polymerization may be present in the obtained polymer. Auxiliary agents remain, resulting in poor quality; post-treatment requires washing with a large amount of water and subsequent drying; and the polymerization process is batchwise, resulting in variations in quality and inefficient operation. , it becomes complicated, and at the same time, the required quality such as equipment cost and operating cost is high. Furthermore, with strict regulations on pollution, it is not desirable to release a large amount of water used for polymerization or washing water that contains auxiliary agents such as dispersants and unreacted monomers.

If a processing device is provided, the required quality will increase, and the manufacturing method will inevitably become industrially disadvantageous. Furthermore, the methyl methacrylate polymer produced by the above method generally has sufficient partial decomposition resistance. (During molding, one claw is combined with heat in the extruder during molding.) Solution 1. -C volatile fraction is produced and it is extruded first
In many cases, the molded plate produced bubbles and a satisfactory molded product could not be obtained.

In view of this situation, the inventors of the present invention conducted a thorough examination of the manufacturing method of extruded plates in order to eliminate the above-mentioned drawbacks, and as a result, they found that the above-mentioned drawbacks could be eliminated by adopting a special process.  Heading The present invention   Completed.

The first object of the present invention is to produce thermoplastic 4WI fat extruded plates with consistent quality! p′! The goal is to provide a manufacturing method.

The second purpose of the present invention is to manufacture extruded plates from the shell body at once.
The object of the present invention is to provide a method for producing extruded rods that is advantageous in the filtration industry.

The third object of the present invention is to have excellent heat resistance and stiffness.

It is an object of the present invention to provide a method for continuously passing through an extruded plate 111 without bubbles due to foaming even during extrusion under high temperature.

That is, the gist of the present invention is to provide an extruded plate made of polymethyl methacrylate or a methacrylic copolymer containing methyl methacrylate units of 800 N or more, alkyl acrylate or alkyl methacrylate (excluding methyl methacrylate) units of 200 N or less, and In the method for producing o-oi to 1.0% by weight of Rimerkabutan and the following formula (% formula %) [wherein A is the number of moles of the polymerization initiator in 100% of the Eiha body, and B is the radical polymerization initiator. The monomer mixture of the polymerized F tree containing an amount of radical polymerization initiator that satisfies the half-life (time) at the polymerization temperature is continuously supplied to one reaction zone, and the monomer mixture in the reaction zone is The reaction mixture was heated to 130~
Seven polymerizations were carried out at a temperature of 200° C. with stirring and mixing substantially uniformly, and while maintaining the viscosity of the reaction mixture at a constant value of lO to 500 voids at the reaction temperature of the reaction mixture. (1) The reaction mixture was continuously taken out from the reaction zone, and after separating the polymer and unreacted monomers in a devolatilizing extruder, the polymer was extruded through the die of the extruder for 03 t.

Provided is a method for continuously manufacturing a pressed d1 plate, which is characterized in that it is molded into a plate-like body.

The extruded plate obtained by the method of the present invention (mainly a polymer of methyl methacrylate) contains 80% by weight or more of methyl methacrylate, and 20% by weight or less of alkyl methacrylate (excluding methyl methacrylate). ) units (hereinafter referred to as METAC 1)/
l, called polymer1. f). 411 with methyl methacrylate: alkyl acrylate that can be used for polymerization (
↑、Also having an alkyl group having 1 to 18 carbon atoms θ) θ) Neutral and n-propylene, for example, methyl, ethyl, n-propylene
Included are alkyl radicals having alkyl groups such as alkyl, n-butyl, 2-ethylhexyl, dodecyl, suy-allyl, and the like. Also, Meg Lemetak I Le
Alkyl methacrylate (selected from those having an alkyl group having 2 to 18 carbon atoms), which is a copolymerization component of
Examples include alkyl methacrylates having the same argyl groups as those mentioned above except for the methyl group. Particularly preferred are homopolymers such as qF, polymethyl methacrylate, and copolymers of methyl methacrylate and argyl acrylate selected from methyl and ethyl.

The present invention can be roughly divided into three steps: polymerization, volatile matter separation, and plate forming step. The polymerization process is a continuous bulk polymerization process of the polymer or monomer mixture. The volatile matter separation step is to continuously separate and remove volatile matter, mainly composed of unreacted A-1, from the reaction mixture containing the polymer produced in the polymerization step, and if necessary, add additives to achieve the desired quality. This is the process of obtaining extrusion plate interest. The plate forming process is a process in which a polymer extruded from a deaerated extrusion die is rolled and formed with a roller to produce a plate of a desired thickness.

In the polymerization step, a monomer mixture containing a radical polymerization initiator and a mercaptanke is continuously supplied to the reaction zone for polymerization.

The mercaptans used in the present invention include primary, secondary, and tertiary mercagutans having an alkyl group or a substituted alkyl group, such as n-butyl, inglovir,
n-ocdyl, n-dodecyl + 5el-butyl,
Flec-dodecyl.

tert-butyl mercaptan; aromatic mercaptan;
Examples are phenylmercaptan, thiocresol, 4-t
ert-butyl-0-arocresol; thioglycolic acid and its alkylnisder; β-mercaptopropionate; ebulentioglycol, etc. having 2 to 2 carbon atoms;
18 mercaptans are mentioned. These can be used alone or with 2Ti! The above fire groups can be used together. Among these mercaptans, tert-butyl, n-butyl, n-octyl and n-dodecyl mercaptan are preferred.

What is the amount of mercaptan used? 0.0 for monomer mixture
1~], 0 weight t%. If the amount used is less than 0.01 mm, the reaction rate becomes abnormally high and it may become impossible to control the polymerization reaction, making it difficult to obtain a polymer 7 with constant quality and excellent heat decomposition resistance. . 1.0 again
When the weight exceeds t%, the degree of polymerization decreases. The mechanical properties of the product deteriorate. The preferred route of use depends on the type of mercaptan, but is in the range of 0.05 to 0.5 times.

Examples of the radical polymerization initiator used in the method of the present invention include di-tert-butyl peroxide,
dicumyl peroxide, methyl ethyl ketone peroxide, g-tart butyl perphthalate, g-t
ert.putilhachenzoate + tert.putilver acetate, 2.

5-dimethyl-2,5-di(tert-butylperoxy)hexane. Di-tert amyl peroxide, and 2,5-dimethyl-2,2-di(tert
・Organic peroxides such as 7-/-rubaroxy)hexyne, and azobisimbutanol diacetate, ],
Examples include azo compounds such as 1-azobiscyclohexanecarbonitrile, 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, and 2-cyano-2-propylazoform 1mide. These radical polymerization initiators can be used alone or in combination with 7. More than one species can be mixed and used.

The noise of the radical polymerization initiator in the monomer mixture is determined by adding A to the monomer feed 1 (+ (1), the number of moles of the radical polymerization initiator in
If id half-life (time) is 7, then A and B are satisfied (21 and (3)).

40≧A・B×11)・・・・・・・(1)3≧
A - B X l O' (2)
and 2, 0≧A・( B +10.3) X 1
(1 ゛"-+31.

The method of the present invention is. If the concentration of the radical polymerization initiator used satisfies the above three formulas and the polymerization is carried out under polymerization conditions, an extruded plate having excellent thermal decomposition resistance can be obtained as well as the object of the present invention.

Here, "the half-life of the radical polymerization initiator at the polymerization temperature" means the cliff life of the radical polymerization initiator when it is placed in a dilute solution of benzene at the same temperature as the polymerization temperature.

This can be easily measured according to the method described in Modern Plastics, February 1952, page 144.

The entire reaction mixture in the reaction zone 'Y130'C or above 200℃
Stir and mix substantially uniformly at a temperature below. If the temperature of the reaction mixture is less than 130° C., the viscosity of the system will be high, and mixing or heat transfer will be insufficient, making it difficult to stably control the reaction. Increasing the polymerization reaction temperature to 200°C or higher reduces the viscosity and is advantageous in terms of reaction control, but it also reduces the heat decomposition resistance of the resulting polymer, worsening moldability and causing side reactions. The amount of product produced increases. Therefore, the polymerization temperature of the present invention is 130°C or higher and lower than 200°C, preferably 160°C or higher and 185°G or lower.

In the reaction zone, the viscosity of one reaction mixture is controlled within the viscosity range of 10 to 500 voids at the reaction temperature. If the viscosity in the reaction zone is less than 10 voids, the resulting polymer will have poor thermal decomposition resistance, and the acceleration of the reaction due to the gel effect will not be fully utilized. On the other hand, if the viscosity exceeds 500 voids, the resulting polymer has excellent thermal decomposition resistance, but cannot be mixed or heat-transferred sufficiently, making stable control impossible.

Also used in the practice of the present invention: 1. A preferred example of a reactor is a reactor equipped with an inlet and an outlet, such as a
No. 6-1564], Utility Model Publication No. 8625, etc., which has a function of sufficiently mixing the entire inside of the tank.

In the volatile matter separation process, in which unreacted monomers are the main component, the reaction mixture having a predetermined polymerization rate that is continuously left behind is heated to 20°C (1 to 290°C) under reduced pressure, and most of the volatiles are removed. 1. Continuously separate and remove the residual medium-containing W4' in the final molded plate to 1 or less, preferably 0.3 or less. Used for volatile matter separation. As the filter 4q, a general single-screw extruder or a multi-screw vent type extruder can be preferably used.The volatilized and separated polymer is extruded from a die in a molten state.

The plate forming process requires rolling the molten polymer extruded through the die of a devolatilizing extruder at a temperature of 220 to 260°C using multiple rollers (for example, 0.5 to 12 rollers). 1-4) Step of forming into a round board. Conventional equipment and methods can be applied to the plate process.

The following additives can be added depending on the type and type of push board and the requirements of the customer. For example, No.
- Tousphalyl alcohol nJ plasticizers and lubricants; - Ultraviolet absorbers such as A Nuvin P (Chino) Geigy) and methyl salicylate; colorants, pigments; and high molecular weight polymers such as synthetic rubber. These can be added during the polymerization step or the volatile matter separation step. It is preferable to add it after the polymerization process.

The extruded plate obtained in the present invention has a [η] of 0.04 to 1.0, and is excellent in quality, particularly in transparency and moldability.

A representative apparatus that may be used in the practice of the present invention will now be described with reference to the following.

The monomer mixture containing a radical polymerization initiator and a polymerization regulator 7 passes through a storage tank 1 and a line 2, and is transferred to a line 4 by a pump 3.
Get it and send it to heat v door 5. Here, the temperature-controlled mixture of shells is fed into a reaction tank 7 through a pipe 6.The reaction tank 7 is equipped with, for example, a spiral ribbon stirrer 86 and nine jackets. A medium flows through the reaction mixture in the reaction tank 7 through the discharge line 10, the pump 11, the line 12'?, and the volatile matter separation m1.3.
where the military components were removed.

The molten liquid is discharged from the die I4. The volatile separator 13 is equipped with a screw, a vent, means for addition or cooling, and an additive injection system. Volatile matter, mainly composed of monomers, separated from the vent is line 19v.
It is supplied to the 1T mer heat exchanger 20, and after removing the non-III materials, the volatile component vapor is recovered in full by the total condenser 21.
The monomer stored in the holder 22 and recovered is sent to the pump 23
And line 24 fire line 1 raw material system C is recycled.

The molten polymer extruded from the oven 14 with a volatile content of 11 il and 1 machine 1:3 is transferred to rollers 16 and 16'.

16' cools the molding, takes a bow 1 with roller 17.17' and extrudes plate 18? : Make m. Continuously making videos.

The extruded plate 18 (not shown) is cut into a predetermined length using a cutter.

The manufacturing method of the present invention can be used to produce not only general flat plates, but also laminates with films and the like, and corrugated extruded plates by attaching the equipment.

Examples are shown below. Examples (not limited to ``i'' failures) Below are the following: 1. Low sound IS and %&Subbeam weight part and weight t%.

The examples were carried out using the apparatus system shown in FIG. 1 at .degree. Equipment used σ) Imo-sama 11'! ′, next σ)) market.

Reaction tank internal volume; 300-e Volatile separator; twin-screw IJ knee vent pusher IH machine screw; 90 mm diameter x 2 total length; Evaluation of [η] in Examples was carried out using the following method.

That is, the sample was dissolved in chloroform to form a solution containing 5% by weight of U, and this solution was maintained at 25"C. The number of seconds, t, of the flow upstream between the marked lines of the Ostwald viscometer, and the number of seconds, t, of the chloroform flow down.

The intrinsic viscosity [η] was calculated using the following formula.

However, C is the sample concentration (!/A) Example 1 Consisting of 1.0 parts of methyl methacrylate, 1.15 parts of n-octyl mercaptan, 0.0 parts of tert-butyl τ-oxide (117 parts) The polymerization stock solution was prepared under heavy nitrogen and was continuously supplied to the reaction tank at 15:137 hours.The inside of the reaction tank was pressurized with nitrogen, and the internal pressure was set to 8.
IrL'G was used, and the M combined temperature was 170°C.

Steady operation was reached for about 8 hours, and the stock solution supply was changed to 254 parts, the rotational speed of the stirring blade was increased to 9 Orpm, and sufficient mixing was carried out to make the residence time about 5 hours. The viscosity in the reaction chamber in this steady state was 100 boids. The viscosity in the reaction tank was measured using a viscometer attached to a pipe provided at the bottom of one reaction tank and continuously feeding the reaction mixture to the devolatilization device (the same applies hereinafter).

On the other hand, the temperature of one vent presser is 230℃, and the extrusion part is 240℃.
, the die temperature is 250℃, and the vacuum level of the bed is 9.
bs. The polymer was extruded into a sheet through a hanger coat die and passed through a roller having a roller surface temperature of 95°C.

A methacrylic resin plate having a thickness of about 0.065 [η] and having a thickness of 2 mm was continuously produced. The obtained extruded plate is.

It had excellent transparency and no thickness unevenness.

Example 2 90 parts of methyl methacrylate, 10 methyl acrylate
part, n-dodecyl mercaptan (1,2 (1 part, di-t)
An extruded plate was produced in the same manner as in Example 1 using a polymerization stock solution containing 0.002 parts of ``art-butyl peroxide.'' However, the polymerization temperature was 160°C.

The temperature of the vent extruder is 230°C, the extrusion part is 230"C, and the degree of vacuum in the vent part is 9 to H1.
It was set to abs. The viscosity immediately after leaving the reaction tank was 80 voids and [η] & 0.075 for one polymer.

Driving test 12 (One test was carried out continuously for one hour, but each step was very stable, and the obtained methacryte resin plate was colorless and had excellent transparency.

Example 3 Raw materials for polymerization consisting of 100 parts of methyl methacrylate, 0.002 parts of di-tert-butyl peroxide, and 25 parts of tert-butyl mercaptan were continuously charged into a polymerization tank, and the following φ items were used. The method of Example 1 was repeated to produce an extruded plate with [η) of 0.066.

The extruded plate obtained was colorless and had good transparency.

Temperature inside the polymerization reaction tank: 160℃ Reaction mixture viscosity: 150 boise Extruder temperature 240℃ Dice temperature 250℃ Pent part vacuum degree 8 H1abs

[Brief explanation of the drawing]

Claims (1)

[Claims] (1) Consisting of polymethyl methacrylate or 80% by weight or more of methyl methacrylate units and 20% by weight
% or less of alkyl acrylate or alkyl methacrylate (excluding methyl methacrylate) units.
01% to 1.0% by weight of mercaptan and the following formula % formula % A=ipi body feed f feed 100! The above monomer mixture containing a radical polymerization initiator satisfying the mole number of the middle polymerization initiator is supplied to the reaction zone, and the reaction mixture 'k1 in the reaction zone is
The polymerization is carried out by stirring and mixing substantially uniformly at a certain temperature of 30 ° C or higher and 200 ° C or lower, and the viscosity of the reaction mixture is maintained at a constant value of 10 to 50 (l voids). Next, the reaction mixture is continuously taken out from the reaction zone, and after being separated by fire from the polymer and unreacted A-M bodies in a devolatilizing extruder.The polymer is extruded from the lathe of the extruder and formed into a plate-shaped body. ) Continuous manufacturing method for extruded plates with special fire characteristics.