DE2018527B2 - PROCESS FOR THE PRODUCTION OF FOAMS BASED ON VINYL CHLORIDE POLYMER - Google Patents

Description

R ²

R ¹ -NH-C-N

corresponds, in which X denotes an oxygen or sulfur atom or the imino group, R ¹ denotes a hydrogen atom, an alkyl group with fewer than 6 carbon atoms, an acyl group with fewer than 5 carbon atoms or a carbamyl group optionally substituted with alkyl groups with fewer than 4 carbon atoms, R ² denotes a Hydrogen atom or an alkyl group with fewer than 6 carbon atoms and R ³ a hydrogen atom, an alkyl group with fewer than 6 carbon atoms, an acyl group with fewer than 5 carbon atoms, a carbamyl group optionally substituted with alkyl groups with fewer than 4 carbon atoms or a saturated aliphatic group

is an ester group with fewer than 6 carbon atoms. optionally having J to 12 carbon atoms substituted unsaturated aliphatic or optionally substituted aromatic monocarboxylic acid, Dicarboxylic acid or its anhydrides used and a molar ratio of unsaturated acid to nitrogen derivative the carbon dioxide adhered to 0.2 to 2 and the propellant mixture in an amount of 2 to 100 % By weight, based on the vinyl chloride polymer, is used is according to patent application P 20 18 532.4-43, characterized in that the organic acid used is at least one having 3 to 18 carbon atoms saturated optionally cyano, chlorine, bromine, alkyl, aryl, aryloxy or chloroaryloxy substituted aliphatic Carboxylic acid and / or a corresponding anhydride is used

Vinyl chloride polymers in the context of the description are the homo- and copolymers as well as post-chlorinated ones Polymers of vipyl chloride, their mixtures with each other or with other compatible polymers, such as Polypropylene, polyethylene, polystyrene, polyurethane, vinyl acetate-ethylene copolymers and acrylonitrile-butadiene-styrene copolymers.

If a mixture of vinyl chloride polymer and other compatible polymers is used, the proportion of vinyl chloride polymer should be 50 to 99% by weight of the total mixture. The vinyl chloride polymer should consist of at least 50% by weight of vinyl chloride units; as comonomers come vinyl esters, such as
Vinyl acetate, alkyl acrylates and alkyl methacrylates,
Fumaric acid ester, maleic acid ester,
Chlorofumaric acid ester, chloromaleic acid ester,
Alkyl vinyl ether, vinylidene chloride, vinyl pyridine,
Ethylene, propylene, acrylonitrile and vinyl alcohol
in question. The copolymer can also be a vinyl chloride mono- or copolymer which is grafted with butadiene and acrylonitrile with butadiene and an alkyl methacrylate and / or alkyl acrylate, with butadiene, an alkyl acrylate, styrene and a crosslinking agent such as divinylbenzene.

The polymers are known in any known manner by bulk polymerization, suspension polymerization, Polymerization in fine suspension or microsuspension or by emulsion polymerization manufactured.

For the production of post-chlorinated or perchlorinated vinyl chloride polymers, the one in the is particularly suitable French patent 14 39 877 and additional PS 89 193 described method.

As examples of the nitrogen derivatives of carbonic acid, which correspond to the formula given are mainly urea, biuret, thiourea, Acetylurea, diacetylurea, triuret, guanidine, lower alkyl allophanates, lower alkyl carbamyl allophanates, N-methyl-N'-acetylurea and N-methyl-Ν ', Ν'-dimethylurea called.

The optionally substituted saturated aliphatic acids used according to the invention and the saturated cycloaliphatic !! Acids - the other component of the propellant according to the invention - are the monocarboxylic acids and dicarboxylic acids with 3 to 18 carbon atoms, preferably with 3 to 8 Carbon atoms and the corresponding acid anhydrides.

Examples of the monocarboxylic acids corresponding to this definition are

Propionic acid, butyric acid, valeric acid,
Caproic acid, caprylic acid, lauric acid,

Myristic acid, palmitic acid, stearic acid.
2-cyanobutyric acid, 2-chlorocaproic acid,
2-ethylcaproic acid, phenylacetic acid,
Phenylmethyl acetic acid, phenoxyacetic acid,
Dichlorophenoxyacetic acid.

Cyclopropanecarboxylic acid, Cy clobu tancarboxylic acid and cyclopentanecarboxylic acid

called. The dicarboxylic acids include, for example
to malonic acid, succinic acid,

Glutiric acid, adipic acid, sebacic acid,
Decanedicarboxylic acid (CH ₂ ) io · (COOH) ₂ and
Cyclopentanedicarboxylic acid.

Examples of anhydrides are, in particular, succinic anhydride and propionic anhydride

The molar ratio of saturated aliphatic acid or cycloaliphatic acid maintained according to the invention Acid to nitrogen derivative of carbonic acid is preferably 0.4 to 1.5.

There are at least one of said saturated acids with at least one nitrogen derivative of the Carbonic acid combined to form a propellant mixture, the decomposition temperature of which is at least equal to Gel temperature of the vinyl chloride polymer or above lies'. Preferably the propellant mixture is added to the vinyl chloride polymer in an amount of 2 to 40% by weight, based on the polymer.

Depending on whether a rigid or more or less flexible or soft cellular product is sought is the vinyl chloride polymer with varying amounts of one or more plasticizers added, as they are usually used in the processing of vinyl chloride polymers. this are especially

Butyl foenzyl phthalate, dioctyl phthalate,
Dibutyl phthalate, dicapryl phthalate,
Dinonyiphthalate; Dioctyl adipate, didecyl adipate;
Dibutyl sebacate, dioctyl sebacate; Tricresyl phosphate, trioctyl phosphate, trixylyl phosphate,
Octyl diphenyl phosphate; chlorinated paraffins;
epoxidized oils and esters; polymers
Plasticizers, such as polyesters of adipic acid or sebacic acid, and those at room temperature
solid plasticizers, such as the polymethyl acrylates
and polymethyl methacrylate, polyethyl acrylate
and Polyäthylmethacrylate, Polybutylacryiite and Polybutylmethacrylate and the fatty alcohols
The plasticizers are added to the vinyl chloride polymers in amounts of from 0 to 150% by weight, depending on the desired degree of softness of the cellular product or foam.

Crosslinkable plasticizers can be used, such as diallyl phthalate, ethylene glycol mono- or -dimethacrylate, propylene glycol mono- or dimethacrylate- "55 lat, unsaturated polyester, with which after crosslinking foams with noticeably improved Dimensional stability in the heat can be obtained.

The crosslinkable plasticizers are used in amounts of 0 to 25% by weight, based on the vinyl chloride polymer, used.

In addition to the plasticizers, the vinyl chloride polymers can be mixed with conventional stabilizers and Lubricants are added.

The neutral or basic lead salts are mentioned as stabilizers: carbonate, sulfate, phosphite, Silicate and stearate; the salts of calcium, cadmium, barium, zinc, lithium and strontium, especially those Stearates, octoates and laurates; the tin compounds:

Dilaurate end Dimaleinate of dibutyltin and Dioctyl tin and mercapto compounds such as thioctyl tin and thiobutyltin; Zinc oxide and / or urea and / or biuret (French patent 14 75 865). The stabilizers are used in amounts from 0.2 to 8 % By weight added, based on the vinyl chloride polymer.

The nature and amount of lubricants added depends on the processing method chosen away. Stearic acid, neutral or basic lead stearates, ethyl palmitate, Pa-affine waxes are mentioned, Ester waxes, which in amounts of 0.1 to 3 wt .-% be added, based on the vinyl chloride polymer.

In some cases it is advantageous to include other customary auxiliaries in the vinyl chloride polymers to incorporate; these are, for example, fillers, nucleating agents, structure regulators, crosslinking agents and Dyes (pigments).

Fillers such as chalk, kaolin, silica, soot are sometimes advantageous, but their amount should not be more than 50% by weight, preferably less than 20% by weight of the vinyl chloride polymer.

Nucleating agents are not absolutely necessary but are added, for example an azo compound such as azodicarbonamide, isopropyl azoformate, Barium azodicarboxylate or carbon black; their amount should be 0.05 to 14% by weight of the vinyl chloride polymer.

The main structural regulators are condensation products from ethylene oxide and fatty acids and analogous products in question, which are used in amounts of 0.05 to 1% by weight, based on the vinyl chloride polymer will.

All crosslinkable substances with vinyl chloride polymers come into consideration as crosslinking agents are compatible, for example an ethylene-vinyl acetate copolymer, a polyvinyl chloride grafted with butadiene and acrylonitrile and the above-mentioned crosslinkable Plasticizers. These crosslinking agents are used in amounts from 0 to 25 percent by weight of the vinyl chloride polymer used. The crosslinking takes place chemically in any known manner; she can can also be effected by irradiation.

The different components are mixed together, gelled, using the usual processing methods, such as compression molding, injection molding, extrusion, calendering, coating, deformed and foamed; the various process steps can be carried out separately from one another or are combined with each other, for example gelling and foaming, gelling and deforming or combined shaping and foaming

The blowing agent mixture to be used according to the invention can be used according to the vinyl chloride polymer Gelling can be added.

When processing by compression molding, emulsion polymerization or Polymerization of vinyl chloride polymer produced in microsuspension is used. After mixing a paste is obtained which is then shaped and pressed under temperature and time conditions which lead to gelling. After cooling and demolding, the molding obtained is either heated with hot air or with steam or in a hot water or oil bath or by IR radiation, high-frequency or ultra high frequency expanded.

For processing by extrusion, injection molding and calendering, a vinyl chloride polymer is used which is polymerized in bulk, in Suspension, microsuspension or emulsion. The viscosity number of this polymer can be high if a soft foam is desired; she ^ must be small if a Rigid foam is to be produced.

During extrusion, the mixture is fed into an extruder and the extruded profile then expanded as indicated

In injection molding, the mixture is fed into a screw press or a piston press gelled product is injected into a mold and the molding after cooling and demolding as above indicated foamed The foaming can also take place directly in the mold.

During calendering, the components are mixed with one another, gelled and deformed, and then become Sheets or sheets drawn and also foamed as indicated

If the processing is carried out by coating or brushing with a Plas'isol, then a Emulsion polymerisation or polymerisation in microsuspension produced vinyl chloride polymer is used All components are mixed together to form a paste. The gelation and expansion takes place when passing through the coating machine. It can also be coated with powdered mixtures but in this case a suspension or bulk polymerization is used Vinyl chloride polymer used.

The foams obtained according to the invention can have closed and / or open cells, depending according to the recipe used, processing method and conditions for foaming. The diameter of the Cells and their wall thickness depend on the same parameters.

With the help of the propellant mixture according to the invention, numerous very different foam products can be produced, for example:
thin (<5 mm) white foams with a high density (> 0.2 g / cm ³ ),

thick (5 to 100 mm) flexible foams with a low density (<0.2 g / cm ³ ),

thick (5 to 100 mm) rigid foams in the entire possible range for volume weights (0.025 to 0.85 g / cm ³ ).

The foams produced according to the invention and based on vinyl chloride polymers are diverse Application: for heat and sound insulation, as connecting parts, artificial leather, underlays for floor coverings, for upholstery, in construction, in furniture manufacture and as packaging materials.

The invention is explained in more detail by means of the following examples.

example 1

A plastisol mixer was at room temperature with 200 g of polyvinyl chloride, prepared by emulsion polymerization, Viscosity range 180, determined according to the French standard T 51-013, 32.4 g urea, 38.8 g Adipic acid and 2 g zinc oxide charged and mixed for 15 minutes; thereupon was 70 g of butyl benzyl phthalate added and mixed for a further 10 min. A viscous paste was obtained with the consistency of Kittes.

This paste was in a cylindrical shape with inner diameter 7 cm and height 1 cm is introduced and then at 18O ⁰ C under a Dmrlf vnn mn n "

pressed for 50 min. It was then brought to room temperature cooled and kept under the same pressure for 20 min.

The molding was removed from the mold and allowed to rest for 20 minutes before it was foamed in an oven at 120 ⁰ C for 15 min.

A somewhat soft, cellular product with a density of 0.09 g / cm ^{3 was obtained} .

Example 2 to 4

The procedure was as in Example 1, but the 38.8 g of adipic acid were replaced by various dicarboxylic acids replaced in the corresponding amount.

The conditions and the test results are summarized in Table 1 below.

Table 1

at Dicarboxylic acids lot Foams Be games Art space create weight Ness 27.6 g / cm ³ soft 2 Malonic acid 31 0.14 soft 3 Succinic acid 68 0.17 some 4th Decanedioic acid 0.40 soft

Example 5

The procedure was as in Example 1, except that 39 g of propionic acid were used instead of 38.8 g of adipic acid. A somewhat flexible foam with a density of 0.24 g / cm ^{3 was obtained} .

Example 6

Example 1 was repeated with 26.2 g of succinic anhydride instead of 38.8 g of adipic acid. A flexible foam with a density was obtained. 0.1 g / cm ³ .

Example 7 and 8

The procedure was as in Example 1, with the Modification that instead of urea, other nitrogen derivatives of carbonic acid were used.

The individual conditions and the results are summarized in Table 2 below

Table 2

The mixture was kneaded for IW min at 15 ° C. in a roller mixer until it gelled. It was kneaded further and a mixture of 160 g urea and 200 g adipic acid was added. It was still kneaded for a further 10 min.

The mass was drawn out into films, which were allowed to cool on a flat surface. Then the Foils foamed in the oven at 200 ° C for 15 minutes.

A rigid foam was obtained, its density. 0.1 g / cm ³ bet mg.

Example 10 of mixture he rgestellt of:

500 g polyvinyl chloride, produced by bulk polymerization, viscosity number 60 (French Standard T 51-013),

500 g copolymer of vinyl chloride and vinyl acetate, containing 15% vinyl acetate units, produced by suspension polymerization, viscosity number 60,
162 g urea,
194 g adipic acid,
50 g dioctyl phthalate,
30 g dibasic lead stearate and
10 g dibasic lead phosphite

The mixture was on a for 10 minutes

Roller mixer kneaded at HO ⁰ C until gelling.

Foils were then pulled out, which you can put on a

let cool down on a flat surface. The slides were then

foamed in the oven at 180 ° C. for 15 minutes

The product obtained was a rigid foam with a density of 0.25 g / cm ³ .
35

At- nitrogen derivative of carbon dioxide

Kind of amount

Foam

Space-

weight

g / cm ³

Biuret Acetylurea

32.4 54.4

0.04 0.12

Example 9 A mixture was prepared from:

Example 11 The following were mixed with one another:

1000 g of copolymer of vinyl chloride and vinyl acetate containing 15% vinyl acetate units, produced by suspension polymerization, viscometers tätszahl 60 (franzöüische standard T 51 -01 3), 160 g of urea,
200 g adipic acid,

50 g ethylene glycol methacrylate,

1 g cumene hydroperoxide,
30 g tribasic lead alfate and 3 g dibasic lead arate
50

The mixture was kneaded ⁿ procurement min ^{at 1} °°° ^{C to Geliere mm} by a roll mill 10. Then, a sheet was drawn fenheit which is obtained on a flat surface

let cool down. The film was foamed and crosslinked in an oven at 200 ° C. for 15 minutes

soft The finished product was a rigid foam with

soft density in the range 'iron O ₁ I g / cm ³ .

The dimensional stability: in the heat was measured with a test specimen 40 mm × 40 mm × 20 mm under a load of 251 g / cm ² , the temperature at which the thickness of the test specimen had decreased by 5% was determined. This temperature was 85 ° C. For comparison, a test was carried out with the same

1000 g copolymer of vinyl chloride and vinyl acetate,

containing 15% vinyl acetate units, produced

produced by suspension polymerization, with 65 receptor, but without ethylene glycol methacrylate

Viscosity numbers of FrenchNonnTSl-Oia), carried out without Qimolhydroperoxiä The obtained

30 g tribasic lead suffate, rigid foam wfc weight 0.1 g / cm ^{3 had} a

3g dibasic lead stearate Waimiorai resistance to only 75 ⁰ CaUf.

£ 09530/493

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Example 12

The following were mixed together in a plastisol mixer at room temperature:

600 g of polyvinyl chloride, obtained by emulsion polymerization, with a viscosity number of 180 (French s standard T 51-013),
12 g urea,
15 g adipic acid and
9 g mixture of cadmium octoate and zinc octoate.

After 10 minutes of mixing, ¹⁴⁰⁰ g of butyl benzyl phthalate was added and mixed for another 30 RNIN.

The paste obtained was crushed, degassed and then spread on a fabric. The coated fabric was passed through a tunnel oven at 200 ^° C. for 3 minutes; the finished product was a flexible foam, density 0.55 g / cm ³ , coated fabric.

Comparative experiments

Comparative tests were carried out against the prior art according to DT-PS 8 51 848 and the effect of the known propellant mixtures of oxalic acid and urea or a urea oxalate with the effect of the blowing agent combination according to the invention in the production of PVC foams compared.

Comparative experiment 1

The general procedure of Examples 1 to 6 of the application was repeated with the modification that instead of the various acids or acid anhydrides used according to the invention, the equimolar Amount, that is 23.6 g of oxalic acid were used. It became a semi-rigid foam with very irregular and partially collapsed cell structure.

In the table below, the results are the results given in the examples of the application juxtaposed

Examples acid Foam structure g / cm ³ nature very irregular, partly Comparison 1 Oxalic acid 0.6 semi-rigid collapsed regularly, not together 1 Adipic acid 0.0C somewhat soft please the same 2 Malonic acid 0.14 soft the same 3 Succinic acid 0.17 soft the same 4th Decanedicarboxylic acid 0.40 somewhat soft the same 5 Propionic acid 0.24 soft the same 6th Succinic anhydride 0.1 soft more irregular and collapsed and coarser, Comparative experiment 2 40 cell structure.

Example 9 of the application was repeated with 118 g of oxalic acid instead of 200 g of adipic acid. the The mass was difficult to knead and stuck to the apparatus in places; also sat down larger amounts of crusts on the cylinders of the kneading machine.

A foam with a density of 0.4 g / cm ^{3 was obtained.} In contrast to this, the foam mixture from Example! 9 of the application knead without any difficulty and process into films; the mass did not stick in places, nor did crusts form on the cylinders of the kneading machine. When foaming, a rigid foam with a density of 0.1 g / cm ³ and a fine, regular and non-collapsed structure was obtained.

3

Claims (1)

Claim: Further development of the process for the production of foams on the basis of $ Vinyl chloride polymers using a nitrogen derivative of KoI, boric acid and an organic one Acid-containing propellant mixture, wherein the vinyl chloride polymer with the propellant and optionally plasticizers, stabilizers ι ο and other common additives are mixed, the mixture is gelled, shaped and foamed, the nitrogen derivative of carbonic acid of the formula R ² R ¹ -NH-CN R ³ corresponds to where X denotes an oxygen or sulfur atom or the imino group, R ¹ denotes a hydrogen atom, an alkyl group with, if less, 6 carbon atoms, an acyl group with fewer than 5 carbon atoms or a carbamyl group optionally substituted with alkyl groups with fewer than 4 carbon atoms, k ^{2 is} a hydrogen atom or an alkyl group with less than 6 carbon atoms and R ^{3 is} a hydrogen atom, sine alkyl group with less than 6 carbon atoms, an acyl group with less than 5 carbon atoms, a carbamyl group optionally substituted with alkyl groups with less than 4 carbon atoms or a saturated one aliphalic pus group with less than 6 carbon atoms and an optionally substituted unsaturated aliphatic or optionally substituted aromatic monocarboxylic acid, dicarboxylic acid or their anhydrides having 3 to 12 carbon atoms and a molar ratio of unsaturated acid is used adhered to nitrogen derivative of carbonic acid from 0.2 to 2 and the propellant mixture in an amount of 2 to 100 wt .-%, based on the vinyl chloride polymer, is used according to main patent application P 20 18 532.4-43, characterized in that the organic acid used is at least one saturated, optionally cyano-, chloro-, bromo-, alkyl-, aryl-, aryloxy- or chloraryloxy-substituted aliphatic carboxylic acid and / or a corresponding anhydride which has at least 3 to 18 carbon atoms 55 The present application relates to an addition to main patent application 20 18 532.4-43 »Method for Manufacture of foams based on vinyl chloride polymers «, according to which soft or rigid Foams based on polyvinyl chloride can be obtained with the help of a novel blowing agent. It is well known to use polyvinyl chloride for the production of foams with organic substances, w: e biuret, add and then heat the mixture. The organic ones decompose in the process Substances and the decomposition products cause the polyvinyl chloride to foam. It is still known as a propellant oxalic acid and urea
and heat them mixed with polyvinyl chloride. In all of these reactions, however, only a weak evolution of gas occurs, so that none Have pollutants produced with a low volume weight. In addition, comparative tests have shown that the combination of urea and oxalic acid merges into a very irregular and partially the cell structure of the foam Sodium carbonate in the presence of an acid such as tartaric acid has also been used as a propellant It is also known to expand polyvinyl chloride with the aid of sodium borohydride, which under the action an acid releases hydrogen which, however, is a flammable and, above all, diffusing gas. What these propellants also have in common is that they can only be used with difficulty or with caution and react with one another even at room temperature, so that the expansion can only be controlled with difficulty can. Furthermore, urea oxalate, which decomposes when heated, is used as a blowing agent for polyvinyl chloride Proposal has been made, but this connection must be made beforehand. In fact, be at Addition of the above-mentioned mixture of oxalic acid and urea to polyvinyl chloride other results obtained than with the addition of previously prepared urea oxalate. The invention aims to overcome the disadvantages of the known processes for foaming polyvinyl chloride to avoid and the production of foams with low density from vinyl chloride polymers to enable, by using a propellant system that is easily can be used whose decomposition products are not flammable and that applies to all known ones Can apply processing methods for polyvinyl chloride. The subject of the invention is a further development of the method for producing foams the base of vinyl chloride polymers using a nitrogen derivative of carbonic acid and an organic acid-containing blowing agent mixture, wherein the vinyl chloride polymer with the Propellants and, if appropriate, plasticizers, stabilizers and other customary additives are mixed together Mixture is gelled, shaped and foamed, the nitrogen derivative of carbonic acid of the formula