DE1301084B - Process for the production of copolymers - Google Patents

Description

1 2

The copolymerization of acrylonitrile with iso- According to the process of the invention, one has sobutylene by emulsion polymerization in aqueous well the reaction vessel as well as all liquid medium in the presence of free radical-forming reactants so largely of oxygen catalysts and emulsifiers under far free that less than 1 part by weight of oxygen per oxygen exclusion is already known. 5 10 ⁶ parts by weight of the processes known from the liquid reaction, but these require long run-time and reaction times, ie conversion times, which are present in the gases present. Reaction system is present. It has been found over from 60 (U.S. Patent 2,549,913) or 120 to surprisingly that by performing the Um-144 hours (U.S. Patent 2,537,146). When placed in a system with such an extremely different previously known process (USA.-Paio low oxygen content, a considerable increase in tentschrift 2 749 330, Example 2), 63 hours are required for the reaction rate to be achieved. So necessary to achieve a 65% conversion, as long as acrylonitrile and isobutylene are used in less than 3 hours, although an aliphatic mercaptan can only be converted to 60% as an accelerator. 137 hours are required for liberation of oxygen, the polymer (US patent 15 mensationsgef äß and the reactants with a 2,531,196, example 1). Inert gas, such as argon, helium, neon or nitrogen, such long reaction times are necessary for the technical to be purged. As a commercial implementation of this process, nitrogen is a major disadvantage. Product most easily available but contains

usually some oxygen, which the polymerization

There has now been a method of making ao that can adversely affect time. However, you can

Copolymers by copolymerization of the nitrogen according to various known methods

s n \ τ l · 1 ο-, τ% · i_ «_ _m ..,., methods of freeing oxygen, for example by

a) (I) isobutylene, 3,3-dimethylbutene _: (l), 2-methyl- _{man ilm through a} ^^^ p _yrO gallol solution

pentene (l), hexene (l) or diisobutylene with conducts.

(II) Acrylonitrile, methacrylonitrile, lower alkyl 25 The to drive out the oxygen from the re-

The time required for acrylates, methacrylates, maleates or partners depends on their

fumarates, vinyl acetate, vinyl chloride, vinyl lumen. For example, 2 to 51 distilled

idene chloride, styrene and its derivatives or lated water are rinsed through for 1 to 5 hours,

Methyl vinyl ketone to increase the level of dissolved free oxygen

_. ,, .... _ """ _Nn,. 30 below about 0.2 parts per million parts.

™ ^e in G ^{em ewichtsverhaltms} of I: Π = 10:90 to _{Andeieisats can sic} £ _the flushing of freshly

yu: IU, or distilled water (within 1 to 12 hours

b) of isobutylene, acrylonitrile and one of the after distillation) superfluous, as its content under (II) mentioned monomers, with the exception of dissolved oxygen usually less than 0.5 parts men acrylonitrile, in a weight ratio of 35 per million parts.

from 10 to 65:50 to 70: 5 to 35 The remaining liquid reactants can on

cleaned in the same way as the water.

in aqueous emulsion in the presence of free radi- The solid reactants can be dry or Kale-supplying catalysts, emulsifiers and one dissolved in deoxygenated water are added

be sufficient to adjust a pH value of 2 to 5.

appropriate amount of acid at temperatures of 25 to The free radical-generating catalysts are

75 ° C under the autogenous pressure of the reaction system that of the mixture of the copolymerizable

found in a low-oxygen atmosphere, added to the monomers and the aqueous phase. At-

one can achieve high reaction rates. Suitable catalysts are potassium persul-

45 fat / sodium bisulfite, hydrogen peroxide / iron (III) -

dry reactants so far from oxygen salts or organic peroxides and hydroperoxides,

Freit has that less than 1 part by weight of oxygen. In the system K ₂ S ₂ O ₈ ZNaHSO ₃ , the two

per 10 ⁶ parts by weight of the liquid reaction catalyst components in general in general

medium and the existing gases existing weight ratio 1: 1 and the emulsion in

Reaction system is present. 50 quantities of 3 to 8 parts by weight per 100 parts by weight

Although it is due to the above state parts total monomer added. At the catalyst

already known in the art, when the H ₂ O ₂ / Fa (III) sator system is heated, the two compo-

Reactant to begin only after the reponent is generally in the weight ratio

action system has been purged with an inert gas, 400: 1 and the emulsion in amounts of

to lower the oxygen content, but 55 has 2 to 4 parts by weight per 100 parts by weight of total

so far this rinsing has not been added with sufficient monomer.

Carried out meticulously and has it as well as emulsifiers can all be used for this purpose

refrain from using the reactants themselves from known emulsifiers. Special

Free oxygen. . Sodium lauryl sulfate, for example, is particularly suitable,

In the production of the bipolymers, the 60 sodium alkylbenzenesulfonates, disodium-4-dodec-

weight ratio of the monomers I: II preferably cyl-oxydibenzenesulfonate, the alkylbenzene-polyethylene

between 30:70 and 80:20 and especially between glycol ether and isooctylphenyl polyethylene glycol

40:60 and 60:40. When using isobutylene, ether.

Acrylonitrile and another of those mentioned under II- The polymerization is preferably carried out at Tempe-

th ethylenically unsaturated monomers is carried out within 65 temperatures between 40 and 60 ° C,

half of the above range, preferably with For coagulation, the emulsion obtained can be

with a weight ratio of (5 to 13): (4 neither can be stirred into isopropyl alcohol, the

to 12): 1 worked. preferably a small amount, about 5 to 10%,

3 4

a weakly acidic substance such as acetic acid. A 1-1 stainless steel pressure vessel was used for this purpose holds, or with stirring to a diluted (e.g. steel with a lid with a sampling-2%) Solution of salts of polyvalent cations, opening, a thermocouple, a supply line for example an aluminum chloride solution, for the reaction components and an argon gas each will. The copolymer falls in Form 5 inlet and outlet lines initially at room temperature white, fine-grained powder, which is alternately evacuated and with Centrifugation or filtration are separated argon and then filled simultaneously with the largest can. Part of the ventilating 24 hours under one

Acrylonitrile-isobutylene copolymers with high argon flow boiled distilled water, the

Acrylonitrile content is in acetonitrile and nitro- ίο deoxygenated emulsifier and the acidic

alkanes, for example nitromethane or nitro-free acid charged. Then the

Ethane, soluble and insoluble in hydrocarbons with the remaining water and then the catalyst

and have unexpectedly high softening points in the mixed pure distilled monomers.

Range from 95 to 110 ° C. This has been most brought on, and the vessel has been sealed. The A-

surprising, since the softening point of polyiso- 15 led all components into the vessel

butylene is significantly below room temperature. under argon pressure.

Coatings and films made by pouring or spraying on solutions of the ^{copolymers or terpolymers produced according to the invention from about 4.2 kg / cm 2} at a temperature of 50 ° C. in aceto under its own pressure, around the isobutylene to keep fluid. Nitrile or nitroalkanes on substrates such as glass; the aqueous phase became white and wood or metal surfaces were obtained after 1 hour, and after 1 hour a 60% strength and elasticity was achieved for chemicals such as acids and conversion. After 5 hours, the copolyalkali was impermeable, weatherproof and the merizate yield was 71%, and the emulsion was stable and shrank even when it came into contact with the appearance of a typical fine-particle latex. Not noticeable by boiling water. The inventive 25 pouring into a mixture of 300 parts of copolymers and terpolymers prepared in accordance with the invention and 20 parts of glacial acetic acid, the emuls are also broken and coagulated for the production of moldings. Suitable after about 3 hours. Fibers and foils. For certain purposes, on standing, the copolymer precipitated as a granular base, for example for impregnation or coating. The glacial acetic acid was applied to a filter made of textiles and paper, the polymer latex 30 can be washed, the copolymers can be used in isopropyl alcohol. The polymers can be taken alone and the alcohol extracted with ether, alone or in combination with other resins. After stripping off the ether, a copolymer of plasticizers, fillers or other modifying agents was obtained in the form of a granular powder, the 76% of which are used. Acrylonitrile and 24% isobutylene and contained one

In the following examples, all 35 relate to a reduced specific viscosity of 0.70. Quantities based on weight.

The copolymers obtained according to the examples, Example 2

were examined as follows: _ .. " _Ώ . . ,,,.

The carbon and hydrogen content was ^{measured according to Beis} P ^{iel 1} ™ ^{τά & the} reaction vessel with

Quantitatively determined according to Liebig. The nitrogen - 40 parts by weight

elemental analysis was 100 after the usual Kjeldahl water

Procedure carried out. The oxygen content became acrylonitrile 50

directly according to the Unterzaucher method (cf.be isobutylene 50

Richter, 1940, Vol. 73 B, p. 391). From the sodium lauryl sulfate .............. 3

Elemental composition, the polymerizate was ₄₅ hydrogen peroxide

composition determined. (30 percent by weight) 6

In all examples, the ferric chloride hexahydrate reaction vessel was 0.005

cleaned or rinsed long enough so that the acetic acid 2.5

System less than 1 part by weight of dissolved oxygen

contained per million parts. 50 charged and the rest of the polymerization after

The reduced specific viscosity was carried out in Example 1. After half an hour

0.1 percent by weight solution in dimethylformamide, the aqueous phase was white and opaque,

determined at 50 ° C. The absolute viscosity was and after 3 hours the copolymer output was

by measuring differently concentrated copolytes 60%. At this point the emulsion had

merisate solutions in dimethylformamide at 50 ° C _{55 give} the appearance of a typical finely divided latex. That

and extrapolating to zero concentration. Copolymers were coagulated, purified, and according to

averages. Example 1 isolated as a granular powder containing 65%

Example 1 contained acrylonitrile and 35% isobutylene and a

An approach consisting of: had a reduced specific viscosity of 0.37.

Parts by weight 60 _ ... "

Water 100 example

Acrylonitrile 50 The vessel was made with the approach according to Example 2

Isobutylene 50 charged and the polymerization according to Example 1

Sodium lauryl sulfate 3 carried out, but now with nitrogen

Potassium persulfate 2 65 and the reaction carried out under nitrogen

Sodium bisulfite 2 was. The polymerization continued within 1 hour

Acetic acid 2.5 and after 4 hours a yield of

brought to polymerization. 67% of a copolymer with a content of 62%

Acrylonitrile and 38% isobutylene and an absolute viscosity of 1.7.

Example 4

An approach according to Example 2 was implemented according to the method according to Example 1, but with 90 parts by weight of acrylonitrile and 10 parts by weight of isobutylene were now used. After 3 hours it was the yield 67%. The copolymer had a content of 91% acrylonitrile and 9% isobutylene and a reduced specific viscosity of 1.09.

Example 5

According to the method according to Example 1, an approach according to Example 2 was implemented, but with now 75 parts by weight of acrylonitrile and 25 parts by weight of isobutylene were used. After 2 hours the yield was 95%. The copolymer contained 74% acrylonitrile and 26% isobutylene and had one reduced specific viscosity of 0.5.

Example 6

According to the method according to Example 1, an approach according to Example 2 was implemented, but with now 25 parts by weight of acrylonitrile and 75 parts by weight of isobutylene were used. After 6 hours the yield was 28%. The copolymer contained 38% acrylonitrile and 62% isobutylene and had one reduced specific viscosity of 0.65.

Example 7

According to the method according to Example 1, a ίο approach according to Example 2 was implemented, but now 10 parts by weight of acrylonitrile and 90 parts by weight of isobutylene were used. After 21 hours the copolymer yield was 16%. The product contained 38% acrylonitrile and 62% isobutylene and had a reduced specific viscosity of 0.57.

Examples 8-14

According to Example 1, copolymers were prepared from a series of monomer mixtures. the Composition of the monomer mixtures, the reaction conditions and the properties of the obtained Polymers are compiled in the following table I:

Table I.

Monomers used Isobutylene Ethyl acrylate Together Around
Wall
lung Stay
Time Together re
dued
specific example Isobutylene Vinylidene chloride settlement
of
Monomeric
mixed settlement
of
Polymers
M ₁ -Mo viscosity Isobutylene Vinyl acetate Mi = M ₂ IVJ.I. 1VX2 Wed IM ₂ 3,3-dimethylbutene- (l) Ethyl acrylate (Weight % hours (Weight 3,3-dimethylbutene- (l) Acrylonitrile percent) 80 16 percent) 1.2 8th 2-methylpentene- (l) Ethyl acrylate 50:50 63 21 20.5: 79.5 1.4 9 2-methylpentene- (l) Acrylonitrile 22:78 45 18th 27:73 1.3 10 50:50 61 22nd 22:78 0.36 11 40:60 50 22.5 10:90 0.41 12th 60:40 67 22nd 26:74 0.56 13th 40:60 68 18th 20:80 0.24 14th 60:40 35:65

According to this procedure, copolymers of isobutylene and diethyl fumarate, diethyl maleate, p-chlorostyrene, methyl vinyl ketone, methacrylonitrile or vinyl chloride and in all cases obtained good yields of copolymers within 10 to 25 hours.

Examples 15-20

According to Example 1, various batches of 100 parts by weight of water, 100 parts by weight of monomer mixture, 3 parts by weight of sodium lauryl sulfate and 2.5 parts by weight of acetic acid were emulsion-polymerized in the presence of 1 part by weight of potassium persulfate and 0.5 part by weight of sodium bisulfite. The aqueous phase became ^{white and opaque within 1} hour and gave typical finely divided latices after 10 to 17 hours. The composition of the monomer mixture, the residence time and the conversion as well as the properties of the terpolymers obtained are shown in Table II.

Tabel!!

example Monomer mixture
made of isobutylene (Mi)
and acrylonitrile (M2) and as M3 composition
of the monomer
mixed
M2: Wed: Ms
(Weight percent) Around
Wall
lung
° / o Stay
Time
hours composition
of the polymer
Wed: M ₂ : M ₃
(Weight percent) re
dued
specific
viscosity 15th
16
17th
18th
19th
20th Methyl acrylate
Methyl acrylate
Methyl acrylate
Butyl acrylate
Vinyl acetate
Diethyl fumarate 50: 46: 4
50:40:10
50:30:20
50: 46: 4
50:40:10
50:40:10 49
67
30th
63
69
51 13th
12th
10
17th
17th
12th 68.7: 25.1: 6.2
58.5: 21.4: 20.2
50.2: 19.0: 30.8
69.5: 19.0: 11.5
63.3: 20.3: 16.4
52.0: 25.1: 22.9 1.31
1.99
1.38
4.88
1.50
1.59

The terpolymers obtained in the manner described above show opposite the acrylonitrile-isobutylene copolymers improved processability and stability under the processing conditions. Compared to the copolymers deliver the terpolymer moldings with increased impact resistance and films and coatings with improved Tear resistance and reduced oxygen permeability.

The above examples demonstrate the phenomenon known in the art that an increase the ratio of isobutylene to acrylonitrile increases the polymerization time required. While in the known processes the polymerization time over a "normal time" of 100 to 150 hours further increases, occurs in the process according to the invention only an extension of about 3 to 5 hours to about 20 hours.

The acetic acid used in the examples has the task of increasing the pH of the emulsion system to ao 2 to 5, since polymerizations catalyzed with persulfate and peroxide are known to be acidic pH values run rapidly. As a weak acid, acetic acid has and will have a certain buffering effect therefore preferably used for the present purpose, but strong acids such as nitric acid, Hydrochloric acid or sulfuric acid can be used.

Claims (2)

Patent claims: 1. Process for the preparation of copolymers by copolymerization of
a) (I) isobutylene, 3,3-dimethylbutene- (l), 2-methylpentene- (l), hexene- (l) or diisobutylene with (II) acrylonitrile, methacrylonitrile, lower alkyl acrylates, methacrylates, maleates or fumarates, vinyl acetate, vinyl chloride, vinylidene chloride, styrene and its derivatives or methyl vinyl ketone, in a weight ratio of I: II = 10:90 until 90:10, or b) excepted from isobutylene, acrylonitrile and one of the monomers mentioned under (II) Acrylonitrile, in a weight ratio of 10 to 65:50 to 70: 5 to 35 in an aqueous emulsion in the presence of free radical-yielding catalysts, emulsifiers and an amount of acid sufficient to adjust a pH of 2 to 5 at temperatures of 25 to 75 ° C under the autogenous pressure of the reaction system in an oxygen-poor atmosphere, characterized in that the reaction vessel and has freed all liquid reactants from oxygen to such an extent that less than 1 part by weight of oxygen is present per 10 ⁶ parts by weight of the reaction system consisting of the liquid reaction medium and the gases present. 2. The method according to claim 1, characterized in that less than 0.5 parts by weight of oxygen per 10 ^{parts by} weight of the reaction system consisting of the liquid reaction medium and the gases present are present. 909 533/372