DE2018532B2 - PROCESS FOR THE PRODUCTION OF FOAMS BASED ON VINYL CHLORIDE POLYMER - Google Patents

Description

R '- NH - C - N

Il \

X R ''

contains, wherein X is an oxygen or sulfur atom or the imino group, R 'is a hydrogen atom, an alkyl group with fewer than 6 carbon atoms, an acyl group with 2s fewer than 5 carbon atoms or a carbamyl group optionally substituted with alkyl groups with less than 4 carbon atoms, R ^{2 is} a Hydrogen atom or an alkyl group with fewer than 6 ^ o 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 less than 4 carbon atoms or a saturated aliphatic ester group with is less than 6 carbon atoms and that

b) at least one optionally substituted unsaturated one having 3 to 12 carbon atoms aliphatic or optionally substituted aromatic monocarboxylic acid, dicarboxylic acid or contains their anhydrides, being a molar ratio of unsaturated acid adheres to nitrogen derivative of carbonic acid from 0.2 to 2 and the propellant mixture in an amount of 2 to 100 percent by weight, based on the vinyl chloride polymer, is used.

Obtain foams with a low density. Attempts have also shown that the Combination of urea and oxalic acid to form a very irregular and partially collapsed one Cell structure of the foam leads.

Sodium carbonate in the presence of an acid such as tartaric acid has also already been used as a propellant. It is also known that polyvinyl chloride can be foamed with sodium borohydride which, under the influence of an acid, releases hydrogen into a combustible? and especially diffusing gas. _These blowing agents can, however, only be used with care and react with one another even at room temperature, so that foaming can only be controlled with difficulty

It continued to feel in the warmth decomposing urea oxalate tested as propellant for polyvinyl chloride; but this substance must first getting produced. In fact, s.ch let them through Addition of the above-mentioned mixture of oxalic acid and urea to polyvinyl chloride gave results don't shed with the results that come through Addition of previously prepared urea oxalate

can be obtained.

The invention is based on the object, di Avoid disadvantages of the known processes and the production of cellular products with little To enable density on the basis of vinyl chloride polymers by using a le.chi applicable chemical system used w.rd whose decomposition products are non-flammable and which is based on all known processing methods for can use these polymers.

The subject of the invention is a process for the production of foams based on vinyl cluonu polymers using a nitrogen derivative the carbonic acid and an organic acid-containing propellant mixture, wherein one aas Vinyl chloride polymer with the blowing agent and optionally plasticizers, stabilizers and others the usual additives mixed, the mixture gels. deformed and foams, characterized by last a propellant mixture is used which

a) at least one nitrogen derivative of carbonic acid of the formula

R ¹ --NH - C

R-

R- ¹

The invention relates to a method of making both soft and hard cellular products based on vinyl chloride polythene, as well as the products themselves manufactured using this process.

It is well known to produce foams from polyvinyl chloride by using polyvinyl chloride mixed with certain organic substances such as biuret, and the mixture then subjected to a heat treatment subject. The organic substances decompose and cause the Pei \ .inylchlorids to expand. It is also known to add oxalic acid and urea / u to polyvinyl chloride and then to heat. In all of these reactions, however, only a weak evolution of gas occurs. who do not allow it '..

contains, wherein X is an oxygen or sulfur atom or the imino group, R ^{1 is} a hydrogen atom, an alkyl group with fewer than 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 ^; represents a hydrogen atom or an alkyl group with fewer than 6 carbon atoms and R ″ represents a hydrogen atom. an alkyl group with less than 6 carbon atoms; ¹ an acyl group with \ v <; iiMrer than 5 KohlensüifföU- -icü. an optionally π: Alk \ groups with pancake than 4 carbon atoms substituted <arbp.rnylgruppe or a saturated a'iipbatisehe Estergruppe r 'less jls <■ carbon atoms in and

b) contains at least one optionally substituted unsaturated aliphatic or optionally substituted aromatic monocarboxylic acid, dicarboxylic acid or their anhydrides having 3 to 12 carbon atoms, a ratio of 0.2 to 2 between unsaturated acid and nitrogen derivative of carbonic acid and the propellant mixture is used in an amount of 2 to 100 percent by weight, based on the vinyl chloride polymer.
Vinyl chloride polymers in the sense of the description are all homopolymers, copolymers and / or each chlorinated polymers of vinyl chloride, as well as their mixture with one another or with other compatible polymers such as polypropylene, polyethylene, polypropylene, polyurethane, vinyl acetate-ethylene copolymer and acrylonitrile-butadiene-styrene copolymer.

If a mixture of vinyl chloride polymers and other compatible polymers is used, the proportion of vinyl chloride polymer should make up 50 to 99 percent by weight of the mixture. The vinyl chloride copolymer should contain at least 50 percent by weight of vinyl chloride units; as comonomers there are vinyl esters, such as vinyl acetate, alkyl acrylates and alkyl methacrylates, fumaric acid esters, maleic acid esters, chlorofumaric acid esters. Chloromaleic acid ester, alkyl vinyl ether, vinylidene chloride, vinyl pyridine, ethylene, propylene, acrylonitrile and vinyl alcohol in question.

The copolymer can also be a grafted homopolymer or copolymer of vinyl chloride with butadiene and acrylonitrile, butadiene and alkyl methacrylate and / or alkyl acrylate. with butadiene, an alk>
acrylate, styrene and a crosslinking agent such as divinylbenzene is grafted.

For the production of polymers and copolymers all known processes can be used for vinyl chloride: bulk polymerization, suspension polymerization, Polymerization in fine suspension or microsuspension or emulsion polymerization. For the production of the post or perchiorated vinyl chloride polymers, that in the is particularly suitable FR-PS 14 39 877 and additional PS 89 193 described method.

To the nitrogen derivatives of carbonic acid, those of the above form! include urea, biuret, thiourestoil, among others. Acetylurea. i) jcetylurea. Triurel, guanidine, lower alkylullophanates, lower alkylcarbamylallophanates, N-methyl-N'-acetylurea and N-methyl-N ', N'-dimeth ;. !urea.
The optionally substituted unsaturated aliphatic acids and optionally substituted aryl acids used in the propellant according to the invention are the monocarboxylic acids, dicarboxylic acids and the existing anhydrides of these acids, containing 3 to 12, preferably 1 to 6, carbon atoms.

Monocarbons which can be used according to the invention
are acrylic acid, cici- ^ acid. Penic acid, meth
Acid, angelicic acid, tericrylic acid. Cinnamon seeds _> oxy-acrylic acid, 2-phenoxy. '■ ■ buten-i-acid. i'r-.i [j,
acid, tetrolic acid, herricarboxylic acid c. l'hemlargylic acid c. 3-butynaine:;, iion / i ^ siiure, "l" oiu \ Ir ->::; ·
Parachlorobenzene '. '. ·

In accordance with the invention. ' vi. "wemlbiü ·. · Dicarh. *; ■: ■■ '.- ■> · ,, ·
Maleic acid. Fumaric acid. Glstta'.ionsäun ·, (i; ra ·. ··, ·
re, itaconic acid. J -I ^! · '\ Οη- ib-disaurc. Bn 'h. r
Phthalic acid and naphtholic acid.
Anhydrides which can be used according to the invention «-inti

auu n acryi-Phe ^r . iri! \

acid. Maleic anhydride, glutaconic anhydride, citraconic anhydride and phthalic anhydride.

The molar ratio of unsaturated aliphatic carboxylic acid and / or to be maintained according to the invention Aryl carboxylic acid to nitrogen derivative of carbonic acid is preferably 0.4 to 1.5.

According to the invention, at least one of the unsaturated acids mentioned is combined with at least one nitrogen derivative the carbonic acid combined to form a propellant mixture, the decomposition temperature of which is equal to or is higher than the gel temperature of the vinyl chloride polymer. Preferably, the propellant mixture is the Vinyl chloride polymers added in a proportion of 2 to 40 percent by weight.

Depending on whether a rigid foam or a more or less soft, cellular product is made different amounts of plasticizers are added to the vinyl chloride polymer, as they are usually used when processing vinyl chloride polymers Find use. Butyl benzyl phthalate, dioctyl phthalate and dibu are particularly suitable tylphthalate, dicaprylphthalai, dinonylphthalate; Dioctyiadipate, Didecyl adipate; Dibutyl sebacate, dioctyl sebacate: tricresyl phosphate, trioctyl phosphate, trixylyl phosphate, Octyl diphenyl phosphate; chlorinated paraffins; epoxidized oils and esters; polymeric plasticizers such as polyester adipic acid or sebacic acid and finally plasticizers that are solid at room temperature, such as Polymethyl acrylate and polymethyl methacrylate, polyethyl acrylate and polyethyl methacrylate, polybutyl acrylate and polybutyl methacrylate and fatty alcohols.

The plasticizers are used in amounts from 0 to 150 percent by weight, based on the vinyl chloride polymer. added, depending on the desired degree of softness of the / urgent product.

It is also possible to use crosslinkable plasticizers such as diallyl phthalate, ethylene glycol mono- or dimethyl acrylate. Propylene glycol mono- or dimethacrylates and unsaturated polyesters which, after crosslinking, give tough products whose heat resistance, d. H. Dimensional stability under heat, is noticeably improved.

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

Customary stabilizers and lubricants can also be added to the vinyl chloride polymer will.

The following stabilizers are mentioned: The neutral or basic lead salts, namely carbonates and sulfates. Phosphites. Silicates and stearates; the calcium, cadmium, barium, zinc, lithium and strontium salts, in particular the steara, octoate and laurate; the tin compounds, namely the dilaurates and dimaleates before, dibutyltin, dioctyltin, thiooctyltin and ThiobuiYi.-inn: zinc oxide and / or urea and / or biuret (French patent 14 75 865). These stabilizers are used in amounts of 0. ¹ to 8 GcwichispC'.i / .ent. based on the vinyl chloride polymer used.

The nature and amount of used

i. iiüiitel depend on the chosen processing : i-: i- ■ "; ■■, lh The following examples are given: stearin- ■ ; ure. iiie neutral or basic lead carafe. \ ethyl palmitate, paraffin waxes. Ester waxes; the Gleiimiuei are used in amounts of 0.1 to 3 percent by weight based on the vinyl chloride polymer.

In some cases it may be useful to go to the

Incorporate vinyl chloride polymer additives as they are usually when processing polyvinyl chloride only get application. These are, for example, fillers, nucleating agents, syrup regulators, Crosslinking agents and dyes.

Fillers such as clay, kaolin, silica and Carbon is sometimes desirable; their amount should not exceed 50 percent by weight, preferably make up less than 20 percent by weight of the vinyl chloride polymer, ίο

Nucleating agents are not absolutely necessary, but can be added; come into question for example azo compounds such as azodicarbonamide, isopropyl azoformate, barium azodicarboxylate or carbon black, in amounts from 0.05 to 1.5 percent by weight based on the vinyl chloride polymer.

The structure regulators are mainly products of the type condensation products of ethylene oxide Fatty acid chains and are available in amounts from 0.05 to! Percentage by weight, based on the vinyl chloride polymer, used.

All crosslinking agents compatible with polyvinyl chloride and vinyl chloride polymers can be used as crosslinking agents in question, for example an ethylene-vinyl acetate copolymer, a graft polymer Butadiene and acrylonitrile on polyvinyl chloride and the crosslinkable plasticizers listed above. These Crosslinking agents are used in amounts of 0 to 25 percent by weight, based on the vinyl chloride poly- ^ mer, used. The crosslinking takes place chemically by any known method. she can can also be effected by irradiation.

The various ingredients are mixed, gelled, deformed and foamed in the course of the common processing methods such as compression molding, injection molding, extrusion molding, calendering and coating, the individual operations being carried out separately from one another or combined with one another will; for example gelling and foaming, gelling and compression molding or compression molding and foaming combined.

The blowing agent mixture according to the invention can be added to the vinyl chloride polymer after gelling. ₄ s

In compression molding, a vinyl chloride polymer prepared by emulsion polymerization or microsuspension polymerization is preferably used. After mixing, a paste is obtained which is then shaped and pressed under temperature and time conditions which thus allow gelation. The molded part obtained is foamed after cooling and removal from the mold, either with hot air or water vapor in a hot water bath or a hot oil bath or by IR irradiation or by _ss high frequency or ultra high frequency. _{For processing by extrusion, injection molding and calendering, a <10} vinyl chloride polymer produced by bulk polymerisation, suspension polymerisation, polymerisation in microsuspension or emulsion polymerisation is used. The polymer can have a high viscosity number if a soft, cellular product is desired; If a rigid foam is desired, the viscosity number should be low.

When extruding the mixture into a <, _s plodder is abandoned and the pultrusion is then foamed as indicated.

In injection molding, the mixture is used in a screw press or a piston press, the gelled product is poured into a. Injection molded and molded the molding obtained after cooling and demolding is skipped in the manner indicated. That Foaming can also take place directly in the mold

CI llMgl.ll.

During calendering, the ingredients are mixed with one another, gelled and deformed, from which they are made Films or sheets produced and these also foamed in the specified manner.

When processing by coating with a plastisol, a by emulsion polymerization or Polymerization of vinyl chloride polymer produced in microsuspension used. All ingredients are mixed together to form a paste. The gelling and foaming occurs as it passes through the coating machine. For the coating can also powdery mixtures are used; in this case, a suspension polymerization or bulk polymerization produced vinyl chloride polymer used.

The cellular products or foams obtained according to the invention have closed and / or open cells, depending on the formulation, the selected processing method and the conditions at the Foaming. The cell diameters and their woad thickness depend on the same parameters.

According to the invention, very different cellular products can be produced, for example:

thin (<5 mm) flexible 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 with all possible densities (0.025 to 0.85 g / cm ³ ).
The cellular products according to the invention based on vinyl chloride polymers are used in various fields: as heat and / or sound insulation, connecting parts, artificial leather, substrates for floor coverings, upholstery, in the construction industry, in the furniture industry and as packaging materials.

The invention will now be explained in more detail with reference to the following examples.

example 1

In a plastisol mixer were at room temperature brought in:

200 g polyvinyl chloride, produced by emulsion polymerization, Viscosity number 180, measured according to the French standard T 51 013,

32.4 g urea,

30.4 g maleic acid and

2 g zinc oxide.

Mixing was carried out for 15 minutes, then 70 g of butyl benzyl phthalate were added and a further 10 minutes. mixed. A putty-like viscous paste was obtained.

This paste was in a cylindrical shape with inner diameter 7 cm and height 1 cm placed and then 50 min. At 18O ⁰ C and pressed at a pressure of 100 bar. It was then cooled to room temperature and kept under the same pressure for 20 minutes.

It was removed from the mold and the molded body 20 min. Allowed to rest before being min in an oven at 12O ⁰ C for 15. Long expanded.

A soft foam was obtained, the density of which was 0.47 g / cm ³ .

Example 2

The procedure was as in Example 1, but with 30.4 g of fumaric acid instead of maleic acid. The flexible or soft foam obtained had a density of 0.2 g / cm ³ .

Examples 3 to 5

The procedure was as in Example 1, except that the maleic acid was replaced by various monocarboxylic acids corresponding amount replaced.

The monocarboxylic acids, their amounts and the test results are shown in Table 1 below summarized.

Table 1

at acid Ge Foam game weight Art (G) Create space weight (g / cm ³ )

3 Acrylic acid 37.8 0.25 soft 4th Crotonic acid 46 0.30 soft 5 Benzoic acid 65.6 0.25 very soft

Examples 6 and 7

It was according to Example 1, but with anhydrides in the corresponding amount instead of maleic acid worked. The reaction conditions and the results are summarized in Table 2 below.

Table 2 Anhydrides
Art Ge
weight
(G) Foam
Create space
weight
(g / cm ³ ) soft
soft at
game Maleic acid
anhydride
Phthalic acid
anhydride 25.6
38.8 0.27
0.43 6th
7th

B e ts ρ ie I 8

The following were mixed in a high-speed mixer at room temperature for 10 minutes:

2000 g copolymer of vinyl chloride and vinyl acetate, containing 15% vinyl acetate units, produced by suspension polymerization, with viscosity number 60 according to the French standard T 51-013,
320 g fumaric acid,
300 g biuret and
60 g lead stearate (dibasic).

The mixture was charged into an extruder whose jacket was heated at three different locations: at the filling opening to 100 ⁰ C, in the middle part on 12O ⁰ C and at the mouthpiece to 140 ⁰ C. In the mouthpiece a head portion and a die were set up, which were heated to 140 or 120 ^{° C.} The output of the extruder was 3.5 kg / h. The resulting web was foamed in an oven at 200 ° C. for 15 minutes. A rigid foam with a density of 0.06 g / cm ^{3 was} obtained in this way.

Example 9

The procedure was as in Example 8, but with 550 g of acetylurea instead of 300 g of biuret.

A rigid foam with a density of 0.07 g / cm ^{3 was} obtained.

Example 10 The following were mixed together:

1000 g of copolymer of vinyl chloride and vinyl acetate containing 15% vinyl acetate units were obtained by suspension polymerisation, with viscosity number 60 (French standard T 51-013),

30 g lead sulfate (tribasic) and 3 g lead stearate (dibasic).

The mixture was stirred for 10 minutes at 115 ° C in one Roller mixer kneaded until gelling. This was followed by further kneading and a mixture of 150 g Urea and 160 g of fumaric acid were added. It was kneaded for a further 10 minutes.

The mass was processed on foils, which were allowed to cool on a flat surface and then allowed to ^{foam in an oven at 200 °} C. for 15 minutes.

A rigid foam with a density of 0.06 g / cm ^{3 was} obtained.

Example 11

The procedure was as in Example 10, but only g urea and 80 g fumaric acid were used. A rigid foam with a density of 0.05 g / cm ^{3 was obtained} .

Example 12

The following were kneaded for 10 minutes:

600 g copolymer of vinyl chloride and vinyl acetate, containing 3% vinyl acetate, obtained by emulsion polymerization, with viscosity number 130 (French standard T 51-013), 30 g urea,
30 g of fumaric acid and
9 g mixture of cadmium octoate and zinc octoate

were on it
450 grams of butyl benzyl phthalate

added and kneaded for a further 30 min.

The mixture was then crushed and degassed darau The plastisol was coated onto a paper sheet, and gelled in Tunnelofer min at 200 ⁰ C to expand.

A paper with a soft foam layer was obtained, the density of ^{which was 0.35 g / cm 3.}

Example 13 The following were mixed:

500 g of polyvinyl chloride, obtained by polymerization, viscosity number 60 (French Standard T51-013),

500 g copolymer of vinyl chloride and vinyl acetate containing 15% vinyl acetate units. here produced by suspension polymerisation, viscosity number 60 (French standard T 51-013),

162 g urea,
152 g fumaric acid,

50 g dioctyl phthalate,

30 g lead stearate (dibasic) and

10 g lead phosphite (dibasic).

The mixture was gelled by kneading in a roller mixer for 10 minutes at 110 ° C.

The mass was processed on foils, which were then cooled on a flat surface and placed in the oven 180 ° C was allowed to foam for 15 min.

A rigid foam with a density of 0.2 g / cm ^{3 was} obtained.

Example 14

The following were mixed:

1000 g copolymer of vinyl chloride and vinyl acetate, containing 15% vinyl acetate units, produced by suspension polymerization, viscosity number 60 (French standard T 51-013), 160 g urea,
150 g fumaric acid,
30 g lead sulfate (tribasic),
3 g lead stearate (dibasic),
50 g ethylene glycol dimethacrylate and 1 g cumene hydroperoxide.

The mixture was kneaded for 10 min in a y ₀ roller mixer at HO ^{0 C to gel.} The mass was then processed onto foils, which were allowed to cool on a flat surface and then to foam ^{in the oven at 200 ° C. for 15 minutes.}

A rigid foam with a density of 0.1 g / cm ^{3 was} obtained.

The heat resistance, ie dimensional stability under heat, was determined with a test specimen 40 × 40 × 20 mm under a load of 250 g / cm ² , the temperature at which the thickness of the test specimen had decreased by 5% was measured. This temperature was 85 ° C.

For comparison, the same experiment was carried out, but without ethylene glycol methacrylate and without cumene hydroperoxide. The rigid foam obtained had a ^{density of 0.1 g / cm 3} and its heat resistance was only 75 ° C.

2 «; Comparative experiments There were comparative experiments

Process of DT-PS 8 51 848 carried out and the known propellant mixture of urea and oxalic acid or a urea oxalate with the registration criteria Propellant mixtures compared.

Comparative experiment 1

The procedure was as in Example 1 of the application, but the 30.4 g of maleic acid by the equimolarc Amount of oxalic acid, d. H. 23.6 g, replaced. A semirigid foam with a very irregular shape was obtained Pore structure that partially collapsed. In the table below these results are those of the Results taken from the description of Examples 1 to 7 of the application are compared.

example

V ⁷ Ci glciCi
1

acid

Oxalic acid

Maleic acid

Fumaric acid

Acrylic acid

Crotonic acid

Benzoic acid

density

0.47

0.25

0.25

0.3

0.25

Foam texture structure

Maleic anhydride 0.27 phthalic anhydride 0.43

semi-rigid

soft

soft

soft

soft

very soft

soft

soft

Comparative experiment 2

The procedure was as in Example 10 of the application, but with 160 g of urea and 118 g Oxalic acid. The mixture was difficult to knead in this way and was very difficult to process into a film. The crowd got stuck in places and large amounts of crusts formed on the cylinders of the kneading machine.

The mass expanded to a stiff foam with ss Density 0.4 and a coarse, very irregular and completely collapsed cell structure.

Example 1OA

Comparative experiment 2 was carried out with 152 g of fumaric acid repeated. The mass could be kneaded perfectly and f.Jln

very irregular, sometimes together regularly, not collapsed fine, not collapsed the same.

the same

the same

the same

the same

mix and did not stick to a cylinder, nor Crusts formed.

After expansion, a rigid foam was obtained, the density of which was only 0.09 and the one besides; Very fine and regular cell structure owned.

Example! 11 A

The procedure was as in Example 10 A, but mi 80 g urea and 75.1 g fumaric acid. With the kneader, there were no problems at all, and ei a foam with a fine and regular pore structure and a density of 0.05 was obtained.

Claims (1)

Claim: Process for the production of foams the basis 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 propellant and, if necessary, plasticizers, stabilizers and other customary additives ι ο mixed, the mixture gels, deforms and foams, characterized in that a propellant mixture is used which a) at least one nitrogen derivative of carbonic acid of the formula ι $ K ²