DD257434A1 - PROCESS FOR PREPARING POLYMERS OF VINYL CHLORIDE - Google Patents

Abstract

The invention relates to a process for the preparation of polymers of vinyl chloride or predominantly vinyl chloride-containing monomer mixtures having different performance properties while largely avoiding Wandansaetzen and specks by the suspension process. The method is designed so that are used as suspension stabilizers polysiloxane-polyoxyalkylene block copolymers in concentrations between 0.001 to 0.3 wt .-% based on the aqueous phase and by the Polymerisationsatsatz polymer latices alone or in combination with a particle size of 0.01 to 2 mm in a concentration of 0.001 to 0.5 wt .-%, calculated on the solid, based on the aqueous phase, in a ratio of dispersing agent and additives of 10 to 90 or 90 added to 10.

Description

Field of application of the invention

The invention relates to a process for the preparation of polymers of vinyl chloride by radical polymerization of vinyl chloride and predominantly vinyl chloride-containing monomer mixtures by the suspension process.

Characteristic of the known technical solutions

The suspension polymerization of vinyl chloride or the preparation of copolymers based on vinyl chlorides is carried out on an industrial scale in the presence of dispersants for the preparation and stabilization of the vinyl chloride / polyvinyl chloride suspension in the aqueous phase. It determines u.a. the property of the dispersant system, the distribution of the monomer in the aqueous phase, the morphology of the PVC grain, in particular its porosity, the particle size distribution, or the thermal stability of the polymer. For the processing of the polyvinyl chloride, particularly the bulk density and the plasticizer capacity are of crucial importance. However, both properties are related so that, generally, one size deterioration occurs in the improvement of one size.

As dispersants u.a. Cellulose ethers, as described in DE-OS 2412014, in question. Furthermore, cellulose ethers in a mixture with partially hydrolyzed polyvinyl acetate (DD-PS 145539) or with polyvinyl acetate (DE-AS 1142238) are optionally used in conjunction with nonionic emulsifiers (DE-OS 2945073). To achieve high porosities, additional aliphatic or aromatic hydrocarbons or alcohols are used (US Pat. No. 2875186), (3488328).

It is also known, by adding long-chain fatty acids or their esters or by adding ionic or nonionic surfactants, often combined with other additives, such as reducing agent to the polymerization to increase the plasticizer receptivity (DE-OS 2365134, 2151 703, DE-PS 1545179, DE-OS 2244905.2134604).

Also described is the combination of suspension stabilizers for influencing the plasticizer receptivity (US Pat. No. 3,879,365, DE-AS 1 720328, DE-OS 2209892).

A polyvinyl chloride having a high bulk density, low porosity and a relatively broad particle size distribution is obtained when using styrene / maleic anhydride copolymers as a dispersant (DD-PS 13583.14358).

Furthermore, a polyvinyl chloride having a relatively high bulk density and a good porosity by addition of diallyl or triallyl compounds to the commonly used dispersants or mixtures thereof (DD-PS 151 455).

The known processes have the disadvantage that the dispersants used are macromolecular compounds, which are usually accessible only over several stages of preparation. As a result, the products represented in this way are subject to strong fluctuations in their characteristic image, which in turn has a negative effect on the product properties.

Furthermore, these methods have the disadvantage that they always affect only one size and the others are neglected, d. H. With a high bulk density, one obtains low porosities or vice versa.

Due to the large number of additives, it is often necessary to reduce the deterioration of other product properties, such as i.a. Take the thermal stability into account.

Object of the invention

The aim of the invention is the preparation of homo- and copolymers of vinyl chloride with predetermined particle morphology using novel dispersant systems while largely avoiding wall deposits and specks.

Explanation of the essence of the invention

the technical problem which is solved by the invention

The invention has for its object to provide a process for suspension polymerization of vinyl chloride or predominantly vinyl chloride-containing monomer mixtures using novel Dispergatorsysteme to develop, which allows in the presence of known radical-forming initiators or initiator polymers with different performance properties while largely avoiding Wandansätzen and Make specks.

Features of the invention

The object is achieved in that in the presence of suspension stabilizers from the series of polysiloxane-polyoxyalkylene block copolymers of the general formula,

IUSiO / SiE¹O / / SiEiO Λ SiE *-> j^{m d} "J (D

G.

iO / SiRO / _m / SiH ₂ O / _{q / 2}

SIR ₂ / _{n / 2}

R 1 SiO / SiRO / _{m / 3} / SiR ₂ O / _{n / 2} / SiRO 0 G

in which mean:

R '- identical or different lower, optionally substituted alkyl radicals; preferably methyl groups m - integers or fractions between 1 and 12, preferably between 2 and 5 η - integers or fractions between 30 and 250, preferably between 40 and 120 G - polyoxyalkylene glycol acetate, oils, alkoxylate cyanalkoxylate or urea of the general formula

- / CH ₂ Z ₃ -ZOCH ₂ CH ₂ Zp-ZOCH ₂ CH (CH ₃ ) / _g -R 'R' - OCOCH ₃ , -OH, -OCH ₃ , -OC ₄ H ₉ , -OCH ₂ -CH ₂ CN, -OCONHR "R" alkyl or aryl radical

p, q whole or fractional numbers between 4 and 50

in concentrations between 0.001 to 0.3% by mass, based on the aqueous phase, of the polymerisation batch polymer latices alone or mixtures thereof having a particle size of 0.01 to 2 / xm in a concentration of 0.001 to 0.5% by mass after the solid, based on the aqueous phase, in a ratio of dispersing agent and additives of 10 to 90 or 90 to 10 are added.

As polymers come u.a. Homo- or copolymers of vinyl chloride, vinyl acetate, styrene, butadiene, isoprene, acrylonitrile, acrylic acid, acrylic acid esters, maleic acid esters or other free-radically polymerizable compounds in question. As further cocomponents, compounds containing one or more carboxyl groups or ester groups which are partially or completely saponified, such as saturated or unsaturated aliphatic or aromatic carboxylic or dicarboxylic acids, such as full or half esters of Diels-Alder adducts of maleic acid, such as esterification products of Diels-Alder adducts of maleic acid and, for example, butadiene, isoprene or dimethyl butadiene with, for example Nonylphenolpolyäthylenoxidalkoholen, F.ettalkohol polyäthylenoxidalkoholen or Polyäthylenoxidalkoholen. Other additives include known dispersants such as cellulose ethers, polyvinyl alcohols or dispersion aids such as polyethers, fatty acid esters, di- or triallyl compounds u.a. be added to the polymerization approach.

embodiments

Example 1 to 13

An oxygen-free rinse autoclave was charged with 400 parts of water, 200 parts of vinyl chloride, 0.15 part of lauroyl peroxide, 0.1 part of dicetyl peroxydicarbonate and the amount of polysiloxane-polyoxyalkylene block copolymers (PPB), polymer latexes and additives as shown in Table 1.

Example 14

An oxygen-free rinse autoclave was charged with 400 parts of water, 200 parts of vinyl chloride, 0.085 part of lauroyl peroxide, 0.28 part of dicethyl peroxydicarbonate and the amount of polysiloxane-polyoxyalkylene block copolymers (PPB) and polymer latex containing according to Table 1.

at 1 PPB Polymer Latex / additional acid Konzen bulk Zentri C 31 F Saddle game Ma .-% bez. salary tration mass put / xm 39 len 2 on-water Wt .-% Wt .-% g / i soft- 46 G 3 bez. on macher- 76 4 water aufn.% 136 1 CJL 2 3 4 5 6 7 8th 132 9 10 6 0,025 Styrene-butadiene 108 7 Methacrylic acid CP 50 0.08 495 19.0 2.1 0.1 0,013 ditto. 50 0.08 473 20.3 2.2 0.1 0,003 ditto, 50 0.08 477 21.2 2.2 0.1 8th 0.05 ditto. 50 0.04 486 18.3 82 2.1 0.5 0.05 ditto. 50 0.02 545 16.7 2.3 0.1 9 0,025 ditto. 35 0.04 518 14.7 112 1.73 1.2 0,025 ditto. 50 0.04 517 17.2 1.9 0.9 Diels-Alder adduct maleic acid 10 0.05 Styrene-acrylic acid ester 73 Acrylic acid CP 10 0.08 410 24.7 1.9 0.1 0.05 Styrene-butadiene 11 Methacrylic acid CP 50 0.04 492 18.9 89 1.8 0.6 Styrene-acrylic acid ester-acrylic acid CP 10 0.04 12 0.05 Styrene-butadiene 126 Methacrylic acid CP 50 0.04 599 15.3 2.1 0.3 PVC e-latex 0.04 13 0.05 Styrene-butadiene 123 Methacrylic acid CP 50 0.04 557 14.9 1.8 1.1 polyvinyl acetate 0.04 14 0,025 Styrene-butadiene 107 Methacrylic acid CP 50 0.02 591 14.6 2.2 2.1 diallyl 0.01 0,025 Styrene butadiene ^ Methacrylic acid CP 50 0.02 553 12.1 2.0 1.2 Polyacthylenoxidacrylat 0.01 0.05 Styrene-butadiene Methacrylic acid CP 50 0.05 505 25.4 1.7 0.1

Claims (4)

1. A process for the preparation of polymers of vinyl chloride by radical polymerization of vinyl chloride and vinyl chloride predominantly monomer mixtures in the presence of known radical-forming initiators or initiator systems by the suspension process, characterized in that in the presence of suspension stabilizers from the series of polysiloxane-polyoxyalkylene block copolymers of the general formulas RJSiO / SiRO / / SiRJO / _n SiRJ. _(|) G
or GR ^ SiO / SiR Ό / _m / SiRp / ' _{n / 2} -SiR ₂ G n / 2 (II) G
or RJSiO / SiJiO / _{m / 3} / BiB-O / _{n / 2} / SiRO _{/ ffi / 3} SiRJ o k i
0 in which mean: R '- identical or different lower, optionally substituted alkyl radicals; preferably methyl groups m - integers or fractions between 1 and 12, preferably between 2 and 5 η - integers or fractions between 30 and 250, preferably between 40 and 120.G - polyoxyalkylene glycol acetate, oil, alkoxylate, cyano alkoxylate or urea residue of the general formula R '-OCOCH ₃ , -OK-OCH ₃ , -OC ₄ H ₉ , -OCH ₂ -CH ₂ CN, -OCONHR " R "alkyl or aryl radical" p, q whole or fractional numbers between 4 and 50 in concentrations of between 0.001 to 0.3 mass% ₍ t> based on the aqueous phase, the polymerization batch polymer latices alone or in combination with a particle size of 0.01 to 2 μηη in a concentration of 0.001 to 0.5 mass%, calculated according to the solids, based on the aqueous phase, in a ratio of dispersant and additives of 10 to 90 or 90 to 10 are added. 2. The method according to item 1, characterized in that as u.a. Homo- or copolymers of vinyl chloride, styrene, butadiene, isoprene, acrylonitrile, acrylic acid esters, maleic acid esters or other radically polymerizable compounds in question. 3. The method according to item 2, characterized in that as further cocomponents compounds containing one or more carboxyl groups which are partially or completely saponified, such as saturated or unsaturated aliphatic or aromatic carboxylic or dicarboxylic acids and total or half of the Diels-Alder adducts maleic acid, such as esterification products of the Diels-Alder adducts of maleic acid and, for example, butadiene, isoprene or dimethylbutadiene with, for example, nonylphenolpolyethylene-alkyl alcohols, fatty alcoholpolyethylene-alkyl alcohols or polyethylene oxide alcohols. , 4. The method according to item 2, characterized in that known as further additives dispersants such as cellulose ethers, polyvinyl alcohols or dispersion aids such as polyethers, fatty acid esters, dioder triallyl compounds u. a. can be added.