DE1915903C3 - Process for the production of water-soluble polymers - Google Patents

Description

3 4

For a satisfactory course of the process, solution of the monomers is added, the thickness of the applied polymer. Temperature conditions are kept so that the sizing reaction mass plays a role. Remains in solution with layered catalyst. In this case, however, a thickness of 1 to 30 mm must be achieved. Good results are to be observed so that the temperature is not so high. In most cases a layer thickness of 5 is sufficient to initiate the polymerization. An azo 12 to 13 mm is particularly advantageous. Likewise catalyst was of the type mentioned falls at a Tempe But even with layer thicknesses of 1.5 mm, 3.0 now worked satisfactorily under temperature 37.8 ⁰ C from the solution and, therefore, as well as 6.0 mm, while the temperature should be at least for The layers can also be thinner at this height, but the upper one is to be kept if the catalyst with the water limit is a factor to be taken into account. io ring monomer solution is mixed.

The concentration of the Moao to be polymerized According to one embodiment of the invention

Meren in the Lösiing depends on the heat of reaction according to the process is dis with the catalyst

away. Since mixed monomer solutions are generally produced in metal dishes at higher concentrations

of the monomer in the polymerization mixture is more that with an inert layer, for example

If heat is generated, this monomer concentration must be coated with 15 polytetrafluoroethylene. The bowls

tration can be controlled so that the heat of reaction are placed in a drying system in which the

at least part of the solvent evaporates. Temperature increased in any appropriate manner

but neither the polymer formed can nor decompose. Such a system is equipped with a suction

Causes side reactions. During the polymerisation ventilator and a closable suction damper

of acrylamide, it is advisable to provide a monomer * °. At the beginning the suction fan is switched off

Concentration of 20 to 30 percent by weight, ordered and the suction damper closed so that the

moved to the reaction mixture to maintain. Air saturated over the pods and the evaporation

In some cases this concentration can be largely prevented except for the solvent,

3% decrease, but on the other hand it can also be up to while the monomer / catalyst solution is on the

Saturation increases at polymerization temperatures. »5 reaction temperature is heated. The temperature

In general, however, it is between 10 and 50 ° Ό the drying system is then increased until the solution

lie. The layer thickness can also be achieved depending on the reaction temperature. As soon as the response

the monomer concentration used is varied, the monomer solution thickens, and

the. the temperature of the reaction mixture rises above

According to a preferred embodiment of the earth 30 the boiling point. After the reaction has ended

If the process is closed, the suction damper is opened and the suction valve

System carried out in which the air is turned on above the regulator. The drying temperature is then

action film or reaction layer is heated. temperature increased again, preferably to

For example, a low humidity can be 105 ° Γ. Contains when completely dry

can be used, in which the mixture at the beginning with 35 the product still 10 to 15 Vo moisture. the

Warm air is heated. After inserting the polymer layers are dry enough when they are clean

merization, the temperature of the reaction and slightly of the polytetrafluoroethylene coated

mixture over that of the warm air, so that this dead surface of the shells can be solved,

acts as a coolant. When working in an enclosed area, the dry layers are

Senen fixed chamber or a housing 40 temperature-soft, but harden when they open

it is appropriate for the film or layer to be cooled to room temperature. The received

Prepare reaction mixture in bowls. Other polymer can be finer or coarser as required

on the other hand, however, the reaction mass can also be ground on one.

Conveyor belt dryer are spread out, in which the same process steps can be followed

the conveyor belt will be continuously through a drying 45 to different types of polymers

chamber is guided. In any case, the react will be established. But they are particularly suitable for

tion product at the point or on the base formation of polymers and copolymers,

dried where the reaction components originate - one of the monomer components being acrylamide

Hh were subjected to the polymerization. is. Other examples of such polymers are mixed

The process according to the invention is particularly suitable for the production of 50% acrylic acid and 70% acrylic, in particular for the production of water-soluble polyamides and copolymers from 50% acrylic acid merisates from ethylenically unsaturated monomers, and 50% acrylamide,
which are soluble in polar solvents. As part of _R. 11th
game is the production of polyacrylamide, example
In the case of acrylamide in an aqueous solution poly- 55 By mixing acrylamide with deionized material, which contains an azo-bis-iso-butyronitrile-Ka- water, a 30% acrylamide solution was produced which was dissolved with the help of methanol and which contained sodium hydroxide to a pH. The concentration of the acrylamide lies between 5.0 and was set. Separately, 5 layers of 10 and 50 percent by weight, based on the percent by weight of azo-bis-iso-butyronitrile in a methanol mixture, and the concentration of the catalyst 60 were dissolved. The acrylamide solution was heated to 46 ° C at 0.03 to 2 percent by weight, based on the warmed and held at this temperature. Then acrylamide, preferably 0.5 percent by weight, the catalyst solution and the acrylamide gene were based on the dry monomer. To dissolve the solution in a storage tank in such a catalyst, 0.5 to 40 percent by weight, pre-mixed ratio that 0.5 percent by weight of azo, preferably 5 vol of methanol, based on the monomer, 65 bis-isobutyronitrile, based on the acrylamide used. (Dry basis), present in the acrylamide solution

The catalyst is conveniently used as one. A series of rectangular with polytetra-

Separate solution prepared and then to an aqueous fluoroethylene coated aluminum dishes were

5 6

placed in a drying system with a suction time of 1.75 hours, the drying temperature 75 ° C

fan and a suction damper was provided. and the drying time 22 hours.

The drying system was heated to 48 ° €, with Beisniel5

the fan switched off and the damper closed "

was. 5 The process steps were the same as in

The monomer-catalyst solution was then used in Example 4, with the exception that the monomer

the bowls are filled so that the solution in each bowl is a solution of 10 parts of acrylamide, 10 parts of acrylic

Stand 1.27 cm high. Then it was insisted on 77.65 ° C and 80 parts of deionized water,

heated, the pH was 8.6 within about 45 minutes.

The temperature of the solution rose to 48 to 57 ° C and io Be'sDielo

the polymerization was initiated by this P

The process steps were the same as in

essential bandet was. During the reaction of Example 5, with the exception that a mixture of

The reaction mixture boiled and burst, and (NHI ₂ S ₂ O ₈ and Na ₂ S ₂ O ₅ in amounts of 0.025%

due to the heat of reaction was quite a bit 15 or 0.10%, based on the total weight of the

Develops water vapor. The temperature of the solution monomer components, used as a catalyst

rose to a peak of 113 to 119 ° C. About was. The pH of the monomer solution was 8.5,

V * hour after the end of the reaction, this became the temperature for initiating the polymerization

Drying temperature increased to 104 ° C. At 60 ° C, the reaction time 0.75 hours and the drying

Drying took 15 to 17 hours. After an opening time of 16 hours.

After drying, the dishes from _R. -17

removed from the drying system and eaten at room temperature

rature left. The layers obtained from The process steps were the same as in FIG

Polymer were dry enough to be clean of Example 6, with the exception of the catalyst

and slightly of the coated surface of the 45 consisted of only 0.25% (NH ₄ ) j, S ₂ O ₈ .

Let the shells loosen. The moisture content was _. ■ ■ ο

10 to 15%. The detached polymer layers Example β

were still soft at the drying temperature. The process steps were the same as in

but cured during cooling at room temperature Example 6, with the exception that the relative

temperature. 30 quantities of the catalyst components 0.10% or

η ··, - 0.40%, based on the total monomer

"and also 0.1% (based on the total mono-

The process steps were the same as in mer) tetrasodium salt of ethylenediamine tetraacetic

Example 1, with the exception that a 50% strength solvent was added as a chelating agent. The tempe-

The solution from acrylamide in deionized water temperature to initiate the polymerization was 60 ° C,

was turned. The catalyst was in an amount the reaction time 1 hour, the drying temperature

of 0.25%, based on the acrylamide, and the door 75 ^C C and the drying time 15 hours.

Methanol in an amount of 5%, based on the addition of the catalysts mentioned can still

Acrylamide, added. The temperature used to initiate various other catalyst systems

the polymerization was at 60 ° C. A 1% solution 40 should be used. Likewise, the pH values can be varied and

of the dried product in deionized water, the film or layer thicknesses largely changed

at room temperature (25 ° C) had a viscosity. The pressure on the layer from the reac-

of 20.7 cps. mixture during the reaction or afterwards

"· _N : _e i 3 ß ^en d during drying can affect the atmosphere

^S P "45 equal to or below or above spherical pressure

The process steps were the same as in his. Furthermore, the solution of 20% acrylamide and 80% deionized monomer solution can also be flushed with nitrogen while adhering to the described example 1, with the exception that one acrylamide process step is carried out. But how water was used. The temperature was noted to turn already, there is an advantage of the invention derive the polymerization was 60 to ⁰ C and 6I method according to 50 is that without Stickstoffbelüfdic polymerization for 30 minutes. The viscosity can be polymerized at normal air pressure using a 1% solution of the product in deionisicr- can.

tem water at 25 ° C was 47 cPs. The polymers obtained are particularly suitable

for coagulating and sedimenting suspension

B e i s ρ i e 1 4 55 sions. The preferred products are in water

soluble and already small amounts, such as 1 to 15 parts

The process steps were the same as in per million, the same when added to aqueous

Example 1, with the exception that 14 parts acrylic suspensions of suspended solids, such as cloudy,

amide and 6 parts of acrylic acid in 80 parts of deionized silica-containing water, coal washing water,

tem water were dissolved and the pH of the Lö- 60 originating from steelworks or suspended

solution was set to 8.4. The catalyst solution containing iron oxide, very effective and

consisted of 1% azo-bis-iso-butyronitrile in 20% Me- promote the precipitation and settling of the suspending-

ethanol, based on the total weight of the mono-ten solid particles, which by decanting,

merc components. The temperature at which the filtration is initiated or by similar procedures from the

Polymerization was 60 to 66 ° C, the reaction water can be removed.

Claims (6)

Air or atmospheric oxygen are undesirable as they can interfere with the polymerization. In order to eliminate these disadvantages, the reac- 1. Process for the preparation of water-soluble ionic mixture aerated with nitrogen
Polymers made from polymers which are water-soluble in a polar solvent are used as dissolved vinyl monomers, the polymerisation of which uses coagulants for sediments.This includes heat generation, but high molecular weight products are required for this, characterized as vinyl monomers and with the conventional polymerisation processes acrylamide or acrylamide With acrylic acid in ren, it is difficult to prepare such polymers from monomers in a concentration of 10 to 50 percent by weight in polar solvents, because when dissolved, a polymerization catalyst forms slightly viscous masses in the solution. The conditions lyser added and the temperature at least during the polymerization largely affect at least 37.8 ° C, but below the polymerization the properties of the polymers formed, such as tion temperature is maintained, the solution in, for example, a too high polymerization temperature form of an I. up to 30 mm thick layer in a 15 door, which leads to low molecular weight compounds, closed atmosphere for starting the US Pat Polymerization in which a heated, moving surface is used, which releases a closed atmosphere, the temperature of which continues in the range between 100 and the heat of reaction and the gas is 150 ° C. To accelerate the reaction, until the end of the polymerization is used as cooling - Calcium acrylate added, so that the process by means of v is used. can be performed. By the known process 2. The method according to claim 2, characterized in that only low molecular weight poly that to obtain a solid merizate, the little value of a coagulating polymer the temperature of the polymeriza- 25 have. tion solution after completion of the polymerization object of the invention is to provide a method for is adjusted so that the solvent from the production of water-soluble polymers from in one the reaction mixture is removed. polar solvents to dissolved vinyl monomers 3. The method according to claim 1, characterized in that the polymerization also in the opposite that the process can be carried out in the presence of air or atmospheric oxygen and in the event of an outbreak Chamber carried out in the presence of atmospheric low temperatures, spherical air is carried out. can in order to obtain sufficient high molecular weight polymers 4. The method according to claim 1 and 3, characterized _in that are characterized in particular as coagulation that the air are suitable for starting medium. heating the polymerization according to and 35, this object is achieved by a method of einanschließend this heated air to the regulatory kind _initially mentioned, which thereby gekennrung the temperature of the reaction mixture is characterized in that acrylamide or acrylamide is used. Acrylic acid in a concentration of 10 to 50 5. The method according to claim 1 and 4, characterized by weight percent, the solution a polymerization characterized in that acrylamide was added in an amount of 40 percent catalyst and the temperature at min from 20 to? 0 percent by weight and as a catalyst at least 37.8 ° C, but below Polymerisationstor azo-bis-iso-butyronitrile is held in an amount of temperature, the solution in the form of a 0.03 to 2 weight percent, based on the 1 j _{b s} 30 _mm thick layer in a closed acrylamide, are used. Atmosphere to start the polymerization 6. A method according to claim 5, characterized j overall 45 _e is exposed _nem heated gas and anschliekennzeichnet that the catalyst in methanol _enc ß j dj _e polymerization in the closed Atmogelöst is present in an amount of 0.5 to 40 overall Sphere is set by the released heat of reaction, weight percent, based on the acrylamide, and the gas is used until the end of the poly. merization is used as a coolant. so To obtain a solid polymer is the Temperature of the polymerization solution after The polymerization is adjusted so that the solvent is removed from the reaction mixture. The polymerization can take place in the presence of atmo- The invention relates to a method for carrying out spherical air. To initiate Production of water-soluble polymers from in the polymerization can be heated and attached to this air polar solvent dissolved vinyl mono-closing to regulate the temperature of the reactor, whose polymerization can be used with a heat generation mixture. As a catalyst ment runs. azo-bis-iso-butyronitrile, for example, is suitable. He One of the main problems in the production process can be added directly or in a solvent, such as the melting of polymers, is the difficulty that ethanol, dissolved,
During the polymerization forming viscous mass- By adhering to these procedural steps it is to move and handle them. This makes it possible to use high molecular weight, water-soluble polymers in particular when the polymers dry, they form seeds which are considered solids without difficulty noticeable, so that in most cases these can only be isolated. After the end of the polythen are economical, if they are in liquid admixture, the closed system is opened and stand to be kept. In addition, the temperature is set so that the solvent Most polymerization process the presence of escapes.