DE2244957A1 - PROCESS FOR THE PRODUCTION OF COPOLYMERISATES FROM VINYLIDEN CHLORIDE AND VINYL CHLORIDE - Google Patents

Description

KUHElIA KAGAKU KOGYO KABUSHIKI KAISHA
Tokyo - Japan

"Process for the production of copolymers
Vinylidene chloride and vinyl chloride "

Priority, September 1971, Japan, note no. 71-612 / 1971

The present invention relates to an improved process for the preparation of copolymers from vinylidene chloride and
Vinyl chloride, which has excellent physical properties, for example improved heat stability and improved processability, the polymerization time also being shorter than in the previously known processes.

Copolymers of vinylidene chloride and vinyl chloride are

^ because of their excellent low gas permeability in

ίο large dimensions. used to pack food, both

- * · for example in the form of bottles or wrapping foils. Since every-

^ 2 but such packaged food items sometimes at low

at temperatures are stored nuts, i:; t egg; erf localized. that the polymer in question must also have sufficient resistance to cold so that it can be used as a packaging film can be used. Just these improved low-temperature properties it is necessary that the polymer has a higher degree of polymerization, but only in such a degree Auomass that the processability of the same is not impaired will.

In the case of vinylidene chloride-vinyl chloride copolymers, the degree of polymerization is determined from the solution viscosity ( Ί \ _ / _) »

up / c

which in turn depends on the rate of polymerization is. Therefore, in order to produce Polymerisate.mit the promoted solution viscosities, compliance with the above Ensure the favorable properties mentioned, care must be taken that the polymerization rate according to the particular composition of the monomeric mixture at the time of the copolymerization Value does not exceed. Nevertheless, certain monomer compositions are very suitable for the polymerization long times are required, which in individual cases can be up to 100 or even 160 hours.

In order to shorten this polymerization time, the polymerization is therefore already in the form of an emulsion of the monomer mixture carried out, which then results in high molecular weight end products receives .. li & üem case, however, difficulties arise due to the fact that in An ^ c ^ Lu ^ s α ^ before polymerization, compli-

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ornamental follow-up treatments must be carried out until one finally receives the end product. In addition, the particles of the polymer powder thus obtained are irregular and not uniform, and the polymer exhibits a low measured density, which is disadvantageous when the Polymer is extruded or machined. In addition, it is difficult in this case to remove the impurities remaining in the polymer, for example Polymerization auxiliaries, such as emulsifiers or salting out agents, which impair the thermal stability of the polymer, the process yield is reduced and also the risk of discoloration of the products made therefrom Finished products consists, for example of foils, bottles and textile thread.

The object of the invention was therefore to provide copolymers of vinylidene chloride and to produce vinyl chloride which do not have the above-mentioned disadvantages. Besides, it was Object of the invention, the polymerization time is essential to belittle. . .

The inventive method for the preparation of copolymers ^ of vinylidene chloride and vinyl chloride with a vinylidene chloride content of at least 55 percent in the presence of a free radical polymerization promoting catalyst a temperature which is higher than the radical formation temperature of the Kai-.,. rjators is characterized by that the radical polymerization at a temperature im

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Range of 30 to 65 ⁰ C in the presence of O _t O1 to 1.0 Ge, weight percent 1,2-polybutadiene, based on the total amount of present in the monomer mixture of vinylidene chloride and vinyl chloride, is carried out. ·.

Surprisingly, the presence of small amounts results 1,2-polybutadiene during the polymerization meant that did Solution viscosity of the copolymer produced merklioh

is increased. · ■

The copolymers which can be prepared according to the invention from vinylidene chloride and vinyl chloride preferably contain more than 60 percent vinylidene chloride units in the molecule. Appropriate Such copolymers are prepared by adding monomer mixtures used as starting material, which consist of 55 to 95 parts by weight of vinylidene chloride and 45 to 5 parts by weight of vinyl chloride.

The polymerization itself can take the form of bulk polymerization in a non-aqueous medium or as a suspension polymerization in the presence of a suspension aid in an aqueous one Medium or as an emulsion polymerization in the presence of an emulsifier. The technique of suspension polymerization however, in the process according to the invention preferred.

In the context of the invention, anyone can use the radical polymerizatiou ! Ordering catalysts are used, both

Peroxide compounds, persulfates and Afüo catalysis

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ί ■ - _ 5 -

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fools. Particularly suitable catalysts are as follows; lauroyl peroxide, benzoyl peroxide, diisopropyl peroxydicarbonate, Di- (4-tert-butylcyclohexyl) peroxydicarbonate, acetylcyclohexylsulfonyl peroxide, Tertiary butyl peroxypivalate, azo-bis-isobutyronitrile, Azo-bis-valeronitrile, hydrogen peroxide, Tertiary butyl hydroperoxide and / or ammonium persulfate.

The 1,2-polybutadiene used in the process according to the invention preferably has a molecular weight in the range from 600 to about 10,000, the 1,2-polybutadiene bond making up at least 70 percent of the butadiene units ¹ in the polymer chain. The end group of the 1,2-polybutadiene can consist of hydrogen atoms, hydroxyl groups or carboxyl groups. In addition, it is also possible to use partially epoxidized polybutadienes, ie compounds in which the double bond of the branched vinyl group is at least partially epoxidized.

It is known per se that in the polymerization of butadiene the butadiene structure in the polymer chain consists of a mixture of 1,4-cis-butadiene, 1,4-trans-butadiene and 1,2-butadiene. The ratio of these components in the ge. The polymer formed depends largely on the type of polymerization. That. According to the invention to be used polybutadiene contains the 1,2-butadiene structure as the main component and such a structure can be obtained by using, for example, alkali metal catalysts in the polymerization, for example sodium or lithium, or by

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using such alkali metal catalysts carrying out a living polymerization or by for

the polymerization uses Ziegler-type catalysts. It is straightforward by choosing the appropriate type of catalyst possible to obtain a polybutadiene in which 70 to 99 percent of the butadiene bonds in the polymer chain die Have 1,2-butadiene structure.

The amount to be used in the process according to the invention 1,2-polybutadiene depends somewhat on the type of product being made Copolymer from. Generally, an amount of from 0.01 to 1.0 percent by weight is sufficient, but with a range of 0.05 to 0.5 weight percent is preferred. Too large an amount of the polybutadiene increases the degree of crosslinking in the copolymer obtained and thus leads to a strongly crosslinked structure which becomes insoluble in solvents. Accordingly, such copolymers have such an extremely high melt viscosity that they are very difficult to process are.

When carrying out the copolymerization in the presence of polybutadiene according to the invention, the solution viscosity becomes the copolymers obtained increased to a remarkable extent. This means that the critical rate of polymerization in order to achieve the required solution viscosity also increases significantly, so that the required The polymerization time can be reduced by 1/2 to 1/3 of the time that is required for conventional polymer

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sation procedure is required. The method according to the invention is therefore suitable "in particular for large-scale engineering" Implementation as the production capacity increases and the manufacturing cost increases be reduced.. ·

In addition, the polymers prepared according to the invention show superior physical properties in comparison to the known copolymers, especially with regard to a increased thermal stability and better processability as well as with regard to a reduction in the embrittlement temperature and improved deformability, which is based on an increase in the rate of crystallization. These improved Quality properties contribute significantly to the fact that the copolymers prepared according to the invention are advantageous differ from the previously known copolymers.

The new vinylidene chloride-vinyl chloride copolymers leave can be processed in a simple manner by means of customary methods, for example they can be processed from them by melt-spinning processes Manufacture threads using blow molding processes, which can be processed into bottles and using the tube process films are made from it.

Comparative example T

A 10 liter stainless steel autoclave having pad-shaped stirring blades becomes one of 4 liters water purified by ion exchange, which contains 4.0 g of methyl cellulose, is charged and then flushed with nitrogen, until the air is completely replaced by nitrogen.

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Then you dine. a monomer mixture of 1.4 kg Vinylidene chloride containing 2.4 g of di-propyl peroxy carbonate and 0.6 g of 2,6-di-tert-butyl-4-methylphenol, and 0.6 kg Vinyl chloride, whereupon this batch is polymerized at a temperature of 36.degree. After a period of polymerization after 160 hours, the unreacted monomer is removed from the autoclave, and then it is formed. Polymer washed with water and dried.

^: This gives fine white polymer particles with a degree of polymerization of 75 percent and a solution viscosity "h, of 0.057 *

Comparative example 2

The polymerization batch of Comparative Example 1 is polymerized, however, the polymerization temperature, starting from an initial temperature of 35 C,

(20 hours) is gradually increased. The temperature thereby keeping for 8 hours at 38 ⁰ C, for 8 hours at 42 ⁰ C, θ hours at 47 ⁰ G and 13 hours at 53 ⁰ C.

After a polymerization time of 57 hours, calculated from the beginning of the polymerization, the polymer obtained in this way shows a degree of polymerization of 77 percent, but the solution viscosity is only 0.045. A polymer with such a low solution viscosity does not show sufficient strength to be used as a packaging material for food to use.

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example 1

It becomes the same monomer mixture as in the comparative example 1 and 2 used, but also 4.0 g of a 1,2-polybutadiene with hydrogen as an end group, a middle one Molecular weight of 1000 and a content of 1,2-polybutadiene structure of 91 percent are present in solution in the approach. The polymerization is carried out according to the procedure of the comparative example 2 carried out with constant raising of the polymerization temperature.

After a polymerization time of 58 hours, a product becomes with a degree of polymerization of 76 percent and. a solution viscosity TO / of 0.056 obtained, with the appearance the polymer particles do not differ from the copolymer which has been produced without the addition of 1,2-polybutadiene,

The addition according to the invention of small amounts of 1,2-polybutadiene thus has the effect that the polymerization time is shortened by half to a third of the time that is usually is required for the polymerization, but the solution viscosity is no lower than it is also desired in the case of conventional copolymers.

Example 2

The monomer mixture of Comparative Examples 1 and 2 is used again, but this time 1O ₈ O g of a 1 ^ -Polybutadiene are dissolved in the batch, which is a

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partially lepoxidized product with Y / asserutoff as the end group, which contains 8.2 percent oxygen in the form of oxirane rings and has an average molecular weight of 1,093. The polymerization itself is carried out as in Example 1 with an increase the polymerization temperature carried out.

An end product with a degree of polymerization of 74 percent and a solution viscosity is obtained within 57 hours of 0.070.

Example 3

The monomer mixture from Comparative Examples 1 and 2, which, however, additionally contains 4.0 g of a 1,2-polybutadiene with a hydroxyl group as an end group and an average molecular weight of 1000, is carried out according to the procedure of Example Ί polymerized while constantly increasing the polymerization temperature.

After a polymerization time of 57 hours, an end product is obtained with a degree of polymerization of 75 percent and a solution viscosity of 0.057ο

Example 4

Glass ampoules with a capacity of 1000 ml each are charged with a monomer mixture which consists of 40 g vinylidene chloride with a content of 0.075 g biifiopropyl peroxydicarbonate and 10 g vinyl chloride. In addition, this monomer batch varying amounts of a 1 , 2 -PoIy-

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■. ■ »11 - ■ -. 22U957

butadiene added, which has a carboxyl group as an end group * and has an average molecular weight of 5000 »

The glass vials are rinsed after filling with nitrogen until all oxygen displaced therefrom, and then a bulk polymerization is carried out for 65 hours at 40 ⁰ G.

The amounts of 1,2-polybutadiene used and the degree of polymerization, the solution viscosity and the melt viscosity of the copolymers in question are shown in Table I below;

_ labile I. Solution "
Viscosity, Melting
V ₁ -
viscosity
(η) 0.049 1.83 x 10 ⁴ Added amount of
1,2-Pplybut ad i en
(Si) Polymerisa
degree of movement,
'(*) 0.057 3.36 10 ⁴ ■ 0 93.0 0.071 7.91 x 10 ⁴ 0.1 92.5 0.071 10.3 x 10 ⁴ " 0.2 92.5 0.040 16.5 χ 10 ⁴ 0.3 87.5 0.027 35.5 x 10 ⁴ 0.4 89.5 0.5 8.9.3

*) Measured by means of a pourable

.keitspTÜfers at 170 ⁰ C.

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The numerical values in the table above show that the procedure according to the invention is excellent Results relating to the solution viscosity can be obtained. If more than 0.5 g of 1,2-polybutadiene is used, however, the proportion of the polymer which is insoluble in a solvent increases and, in addition, the melt viscosity also increases too strong too.

B e is ρ i e 1 5

The as well as the BR in accordance with the invention Examples 1 3 copolymers obtained according to Comparative Examples 1 and 2 are under pressure into sheets of 2 mm thickness compressed (preheating for 2 minutes at 180 ⁰ C and pressing for 1 minute at a pressure of 100 kg / cm ).

one
These foils are tested for thermal stability in a gear test oven at 150 ° C. and the results obtained confirm that the copolymers produced with the addition of 1,2-polybutadiene show excellent thermal stability and do not discolour yellowish, as is the case with conventional polymer products the case is.

In addition, the light resistance is tested on each film, by exposing them to sunlight. In this test, too, the result shows that the addition of 1,2-polybutadiene copolymers produced a superior light

! l:

resistance compared to the polymers show which have been prepared without the addition of 1,2-polybutadiene, and

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that they are also to a much lesser extent by this Photosensitivity test caused change in show physical properties.

Examples

According to Comparative Example 1 and the inventive · Copolymers obtained in Examples 1 and 3 are 8 parts by weight Add mbutyl sebacate and mix carefully. Tests are then carried out on these polymer mixtures with regard to the Melt viscosity and the rate of crystallization carried out, the results of which are given in Table II below are put together.

Table II

Addition- Poly- Polymer- Solution- Melt- Crystallites Amount of meri- risa- viscosi- viscosity sationsan 1,2-sation- act at 170 ⁰ C speed degree of polishing. . age

buta time at 3O ⁰ C

dien ('h /) ( Y]) Ch)

Comparative.

at- ,

game 10 160 75 0.057 5.75 x 10 ^; 42

At- ' r,

game 1 0.2 58 76 0.056 4 ₉ 2 χ 10- ³ '21

At- ^

game 3 0.2 57 75 0.057 4.4 χ 1 (T 22

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-, 14 -

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This table shows that the products manufactured according to the invention Even with the same solution viscosity, copolymers show a lower melt viscosity than the polymer of Comparative Example 1. These facts show the good processability of the copolymers according to the invention. The rate of crystallization is practically twice as high as that of the copolymer from Comparative Example 1, which indicates the higher or better deformability.

Ausserdera were extruded di * ³ subject polymer blends in the molten state and then in the tube method 7, a film v processed at the Verfärbbarkeit, the light transmittance and the embrittlement temperature were measured. The results obtained are summarized below in Table III, from which it can be seen that the film produced from a copolymer according to the invention has superior properties. In addition, it can be stated that the properties at low temperatures of the copolymers according to the invention are also significantly better than those of the products produced in the customary manner.

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Added
Amount of
1,2-poly
butadiene Table III Discolorable
speed 2244957 0
. 0.2
0.2 light yellow
colorless
colorless II clit through
nonchalance
■ (50 · - Promised-
. fertilizer temperature
rature
( ⁰ O); Comparison
example 1
example 1
Example 3 52
71
70 -13 "
-16.
-16 '

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Claims (2)

Claims Process eur production of copolymer leathers from vinyl lden- * chlorld and vinyl chloride with a vlitylidenechlorld content of at least 55 per cent in the presence of a catalyst which promotes radical polymerization at a temperature which is higher than the radical formation tea nature of the catalyst. * Gekenneei characterized seframe that the radical polymerization at a temperature in the range of 30 to 65 ⁰ C in the presence of 0.01 to 1.0 weight percent 1,2-PoIybutadien, beisogen on the total amount of monomer present Id vinylidene chloride and vinyl chloride , performs 2. The method according to claim 1, characterized gekenneelohnet that one 1,2-polybutadlene with a molecular weight of about 600 to 10,000 applies, in which the 1,2-polybutadiene bonds have at least 70 percent of the butadiene unit in the polymer chain • · ■ turn off" . 3. Method according to claim 1 and 2, characterized in that dasB that 1,2-polybutadiene hydrogen atoms, hydroxyl groups and / or has carboxyl groups as all end groups. 4 · The method according to claim 1, characterized in that one a partially epoxidized 1,2-polybutadiene β insert. 309812/1151