DD216941A1 - PROCESS FOR THE PREPARATION OF VINYL CHLORIDE POLYMERS - Google Patents

Abstract

The invention relates to a process for the preparation of vinyl chloride polymers suitable for the preparation of chemically verschheeumbaren plastisols of low to medium viscosity, by microsuspension of vinyl chloride at K values of 67-80 and increased thermal stability with known initiators and emulsifiers and / or dispersants. The objective is achieved in that the polymer particles having average sizes of 0.1 to 1.5 mm, alcohols, carboxylic acids or their esters with 1 to 3-hydric alcohols having C numbers of 8 to 20 in amounts of 0.2 to 2, 0% or a. d. Polymer phase which are dissolved in the monomer before the polymerization, or distributed in the batch mixture, or in the case of the carboxylic acids as ammonium salt before, during or after the polymerization are added.

Description

Title of the invention

Process for the preparation of vinyl chloride polymers

Scope of the invention

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The invention relates to a process for the preparation of vinyl chloride polymers which are suitable for the preparation of chemically foamable plastisols by microsuspension polymerization of vinyl chloride (VC).

d 'it confessed ^ St andes ^

It is known j plastisols _$ da h "VC" soft = olyraer- - to foam Biachergemische ₈ physically by gassing while mixing or below, use of chemical blowing agents "Ss fine-pore foams are closed cell obtained (plastic .. '- 68 (197B) 1-2, 800) ·. - -

For Schaumfähigmachung of plastisols, it is known to the starting latex surfactants ₉ mixtures of a calcium salt of alkylbenzenesulfonic acid with Xthylenoxidaddukten of alkyl / aryl acids or «» alcohols in an amount of 0.5 to 3 % _f add (DE-OS 2,246,508 ).

For the same purpose it is also known to add zinc or strontium salts of carboxylic acids, oligoester acrylates or silicon ethers to the paste (Plastmassy 12 (1973) 3). (DB-OS 2 538 389 »US Pat. No. 3,795,634).

The laughing part of the processes mentioned is that _s' require special ι manufacturing method as additives only special products, are usable * Furthermore, it is Mach part, that these special products have a limited compatibility and lead to migration phenomena em final product. - » ^/

; It is furthermore known that foamable products can be prepared by the continuous emulsion process with emulsifier combinations of alkylsulfates, alkyl ether sulfates and alkyl sulfonates (OS 2 428 706). In this Hersteliungsprinzip is essential Kachteil that arise increased Plastisolviskositäten and lower thermal stabilities.

Wach the prior art, no solution is known that allows for the establishment of low to medium viscosity plastisol viscosities and high thermal stability by way of chemical foaming the production of fine-pored and closed-cell Schaurastrukturen.

Object of the invention

The object of the invention is the production of vinyl chloride polymers in the formation of low to medium viscosity plastisols with increased thermal stability of the chemical foaming ·>'

Explanation of the essence of the invention

- The technical problem which is solved by the invention. ''

The invention is based on the object _t to a process for the production of vinyl chloride polymers to develop with using known Polyraerisationshilfsstoffe and technologies targeted setting of plastisol viscosity, thermal stability and chemical "· shear foamability allows is"

Features of the invention

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The object is achieved according erfindungägemäß by the polymer with average sizes of 0.1 - 1.5 / um, alcohols,! Carboxylic acids or their esters

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with 1 bis.'3-valent alcohols with C numbers from 8 to 20 in quantities of Q ₉ 2 to 2 % resp. contained in the polymer phase, the dissolved in the monomer before the polymerization, or in the batch mixture distributed ₉ or in the case of the carboxylic acid as the ammonium salt before, during or after the polymerization are added.

In a pressure reactor, 100 parts of water with 1 ₉ 5 parts of alkyl sulfonate and 0.05 ropes KgS ₂ O ₈ at a pH adjusted with ammonia 9 ₉ 5 submitted * After three rinses with nitrogen, 100 parts of VC are added »At 60 ü / min and 51 ⁰ C internal temperature, the polymerization is taken to the conversion of 85 % , the rest of VC relaxes, worked up the dispersion via a sputtering dryer at 70 ⁰ C Eu'ßtempe'ratur; The product has a K "value of 68 _9, an average particle size of 0.22 / μm and a thermal stability (determined in the stabilizer with BAZ 51 according to TGL 28475/02) of 21 minutes.» One with the plasticizer DOP in the ratio of PVC s DOP β 60 % 40 stirred paste is highly viscous with a value at D m 48j6 s " ¹ of> 16 000

A paste prepared with 2.5 parts of Asodicarbonaraid, 1 ₉ 6 parts of Kicker at a PVC / Welchmacher 'ratio of 100 s 60 gives as 1 mm »stroke at 200 ⁰ C and foamed for 6 minutes a foam with a Vergiew Foam note 3 (scale of 1 - very good, to 5 insufficient).

Example 2 ( Comparative example )

In a pressure reactor, 100 parts of water are presented with O ₉ 8 parts of alkyl sulfonate. After flushing three times with nitrogen, 100 parts of VC are run in via an initiator lock containing 0.1 part of dilauroyl peroxide and 0.02 part of dicetyl peroxydicarbonate. Bach 30 minutes of intensive stirring, the mixture is driven through a homogenizer at a pressure of 3 * 5 JCPa in a reactor, polymerized at 10 U / min and 51 ⁰ C to the conversion of 83 % . The residual VC is relaxed »atomized the dispersion at 55 ⁰ C foot temperature,

Analogously to Example 1, the following quality parameters result:

K-value 70.5 average

Particle size 0.8 / um

therraiscl e stability 41 minutes

Viscosity 2580 mPas

Schaurano e (open pore) 4

Example 3

The procedure ^ is carried out according to Example 2. In the initiator lock 1 part of lauric acid is added simultaneously. The result is a product with the following Kenngrö'ßens

K-value 70 average

Particle size 0.7 / um

thermal stability 43 minutes

Viscosity 2320 raPas

Foam note 2

The procedure is carried out according to Example 2 * Og8 parts of Aramoniumsalses the lauric acid are added to the auspolymeriaierten latex and mixed for 30 minutes after the workup results in a product with the following Kennwertens

K-fert 70 ₉ 5 average

Particle size 0.8 / um

thermal stability 45 minutes

Viscosity,. 2060 mPas

Schauranote, 2>

Carrying out the procedure according to Example 4 "Homogenisation is carried out at a pressure of 4" 5 "MPa:

leads. The product characteristics are

, K-value ', · 71.'' ^N average

Particle size O ₉ 5 / um

thermal stability 43 minutes

Viscosity 4O5O

Foam note 1

Example 6

The procedure is carried out according to Example 2. Into the initiator lock lauryl alcohol is added with the initiator 1 part. The product characteristics arej

K-value average

Particle size 0 _t 7 / um

thermal stability 45 minutes

Viscosity 2620 mPas

foam Sheet

Example 7

The procedure is carried out according to Example 2. In addition, 1 part of a triglyceride of stearic acid are added to the batch mixture. The product characteristics are i

K-value average

Particle size 0.65 / μm

thermal stability 41 minutes

Viscosity 2940 mPas

foam Sheet

Claims (1)

Process for the preparation of vinyl chloride polymers suitable for the preparation of 'chemically foamable low to medium viscosity plastisols' by microsuspension polymerization of vinyl chloride at K values of 6? - 80 and, it increases thermal stability with known initiators and emulsifiers and / or dispersants characterized in that: the polymer particles having average sizes of 0.1 to 1.5 / um, alcohols, carboxylic acids or their esters with 1 to 3-valent Alcohols with G "numbers from 8 to 20 in amounts of 0.2 to 2.0%, based on the polymer phase, dissolved in the monomer before polymerization or distributed in the batch mixture, or in the case of the carboxylic acids as the ammonium salt before be added during or after the polymerization