DE2018527A1 - Process for the production of foams based on vinyl chloride polymers - Google Patents

Description

Description of the patent application

Produits Chimiques PECHINEY-SAINT-GOBAIN, 67, Boulevard du Chateau (92 Neuilly-sur-Seine, France

concerning

Process for the production of foams based on vinyl chloride polymers (il)

Addendum to the simultaneously filed patent application "Process for the production of foams based on Vinyl chloride polymers (I), our reference: 1A-37 602.

The invention relates to a method for producing soft or hard foams based on Polyvinyl chloride with the help of a new type of blowing agent, as well as on the products obtained by this process.

It is generally known to add organic substances such as biuret to polyvinyl chloride for the production of foams and then to heat the mixture. The organic substances decompose and the decomposition products take effect the foaming of the polyvinyl chloride. It is also known to use oxalic acid and urea as propellants and to heat them in a mixture with polyvinyl chloride.

In all of these reactions, however, only a weak evolution of gas occurs, so that no foams with little Have the volume weight produced.

Sodium carbonate in the presence of an acid such as tartaric acid has also been proposed as a propellant. It is also known to add sodium borohydride to polyvinyl chloride

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expand, which releases hydrogen under the action of an acid, but which is combustible and, above all, diffusing Gas is.

What these propellants also have in common is that they can only be used with difficulty or cautiously and react with one another even at room temperature, so that the expansion difficult to control.

Furthermore, urea oxalate, which decomposes in the heat, has been proposed as a propellant for polyvinyl chloride, but this connection must be made beforehand. In fact, when the above mixture of oxalic acid and urea is added to polyvinyl chloride, others become Results obtained than when previously prepared urea oxalate was added.

The aim of the invention is to avoid the disadvantages of the known processes for foaming polyvinyl chloride and the manufacture of cellular products from vinyl chloride polymers to allow a low weight on iron by using a propellant system that is can be easily applied, the decomposition products of which are non-flammable and which can be used in all known processing methods can be used for polyvinyl chloride.

According to the invention, at least one vinyl chloride polymer is mixed with a blowing agent mixture which consists of at least one Nitrogen derivative of carbonic acid and at least one carboxylic acid composed of 3 to 18 carbon atoms is; these acids are either cyano, chlorine, bromine, alkyl, aryl, aryloxy or chloroaryloxy substituted saturated ones aliphatic carboxylic acids or the saturated cycloaliphatic acids; the mixture is gelled, shaped and foamed.

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The homopolymers, copolymers, post-chlorinated polymers of Vinyl chloride, their mixtures with one another or with other compatible polymers, such as polypropylene, polyethylene, Polystyrene, polyurethane, vinyl acetate-ethylene copolymer and acrylonitrile-butadiene-styrene copolymers.

Will be a blend of vinyl chloride polymers compatible with others If polymers are used, the proportion of vinyl chloride polymers should be 50 to 99% by weight of the total mixture.

If a vinyl chloride copolymer is used, it should be at least 50% by weight of vinyl chloride and at least consist of another monomer; vinyl esters such as vinyl acetate, alkyl acrylates and alkyl methacrylates are used as comonomers, 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 are possible.

The copolymer can also be a vinyl chloride homo- or copolymer be that mainly with butadiene and acrylonitrile, butadiene and an alkyl methacrylate and / or alkyl acrylate, with butadiene, an alkyl acrylate, styrene and a crosslinking agent such as diviny! benzene is grafted.

The vinyl chloride polymers and copolymers are produced in any known way. * By bulk polymerization, Suspension polymerisation, polymerisation in fine suspension or microsuspension or by emulsion polymerisation.

The perchlorinated vinyl chloride polymers are also used produced by any known method; suitable is

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in particular the method described in French patent specification no. / 1 439 877 "and its addition no. 89 193.

The nitrogen derivative of carbonic acid, which is a component of the propellant mixture according to the invention corresponds to the general formula:

E ²
E ¹ - HH - C - M ι

X ^

wherein X is an oxygen or sulfur atom or the imino group, R is a hydrogen atom, an alkyl group with less than 6 carbon atoms, an acyl group with fewer than 5 carbon atoms or an optionally substituted one

ρ
Carbamyl group means, R for a hydrogen atom or

an alkyl group of less than 6 carbon atoms and R ^ for a hydrogen atom, an alkyl group with fewer than 6 carbon atoms, an acyl group with fewer than 5 carbon atoms, an optionally substituted carbamyl group or a saturated aliphatic ^ ester group with less stands as 6 carbon atoms.

If the carbamyl groups are substituted, the substituents are Alkyl groups with less than 4 carbon atoms.

Examples of compounds which correspond to the formula given are, in particular, urea, biuret, thiourea, acetylurea, diacetylurea, triuret, guanidine, lower alkylallophanates, lower alkylcarbamylallophanates, N-methyl-N'-acetylurea and N-methyl -N ¹ , N ¹ -dimethylurea called.

The optionally substituted saturated aliphatic acids 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 carbons

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material atoms, preferably with 3 to 8 carbon atoms and the corresponding acid anhydrides.

As examples of the monocarboxylic acids corresponding to this definition 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, phenylmethylacetic acid, Phenoxyacetic acid, dichlorophenoxyacetic acid, cyclopropanearboxylic acid, cyclobutanecarboxylic acid and Cyclopentanecarboxylic acid called. The dicarboxylic acids include, for example, malonic acid, succinic acid, glutaric acid, Adipic acid, sebacic acid, decanedicarboxylic acid (^ 2 ^ 10 * (COOH) and cyclopentanedicarboxylic acid.

Examples of anhydrides are mainly succinic anhydride and propionic anhydride.

The molar ratio of saturated aliphatic acid or cycloaliphatic acid to nitrogen adhered to according to the invention off derivative of carbonic acid depends on the nature of the individual components of the propellant mixture.es and is generally 0.2 to 2, preferably 0.4 to 1.5

At least one of the saturated acids mentioned is added with at least one nitrogen derivative of carbonic acid combined with a blowing agent mixture whose decomposition temperature is at least equal to the gel temperature of the yinyl chloride polymer or above.

The propellant mixture is the vinyl chloride polymer in in an amount of from 2 to 100% by weight, preferably from 2 to% by weight, based on the polymer.

Depending on whether a rigid or more or less flexible one

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or a soft cellular product is sought, -will the vinyl chloride polymer mixed with different amounts of one or more plasticizers, as they are usually used in processing ' of vinyl chloride polymers are used. These are mainly butyl benzyl phthalate, dioctyl phthalate, dibutyl phthalate, Dicapryl phthalate, dinonyl phthalate; Dioctyl adipate, 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 polyesters of adipic acid or sebacic acid and plasticizers that are solid at room temperature, such as the polymethyl acrylates and polymethyl methacrylates, polyethyl acrylates and polyethyl methacrylates, polybutyl acrylates and polybutyl methacrylates 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, unsaturated polyester, with which foams after crosslinking noticeably improved dimensional stability in the heat can be obtained.

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

In addition to the plasticizers, the yinyl chloride polymers the usual stabilizers and lubricants are added.

The neutral or Isasic lead salts are used as stabilizers called: carbonates sulfate, phosphite, silicate and stearate; the salts of calcium, cadmium, bariua, zinc, and lithium

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Strontium, especially the stearates, oetoates and laurates; the tin compounds: dilaurates and dimaleinates of dibutyltin and dioctyltin and mercapto compounds such as thiooctyltin and thiobutyltin; Zinc oxide and / or urea and / or biuret (French patent 1,475,865). The stabilizers are used in amounts of 0.2 to 8 wt - added $>, based on the Yinylchlorid polymer..

The nature and amount of lubricants added depends on the chosen processing method. Stearic acid, neutral or basic lead stearates are mentioned, Ethyl palmitate, paraffin waxes, ester waxes in amounts of 0.1 to 3 wt .- ^ are added, based on the vinyl chloride polymer.

In some cases it is advantageous to use vinyl chloride polymers incorporate other common aids; these are, for example, fillers, nucleating agents, structure regulators, crosslinking agents and dyes (pigments).

Fillers such as chalk, kaolin, silica, carbon black are sometimes beneficial, but their amount should not exceed 50 5% by weight, preferably less than 20% by weight of the yinyl chloride polymer en amount.

Nucleating agents are not absolutely necessary, but can be added, for example an azo compound such as Azodicarbonamide, isopropyl azoformate, barium azodicarboxylate or carbon black; their amount should be 0.05 to 1.5% by weight of the yinyl chloride polymer be.

The main structural regulators are condensation products from ethylene oxide and fatty acids and analogous products in question, in amounts of 0.05 to 1 wt .- ^, based on the vinyl chloride polymer.

All crosslinkable substances can be used as crosslinking agents,

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compatible with vinyl chloride polymers, for example an ethylene-vinyl acetate copolymer, one with butadiene and Acrylonitrile-grafted polyvinyl chloride and the crosslinkable plasticizers mentioned above. These are crosslinking agents in amounts from 0 to 25 percent by weight of the vinyl chloride polymer used. The crosslinking takes place chemically in any known manner; it can also be achieved by irradiation to be effected «

The different components are mixed together, gelled, using the usual processing methods, such as compression molding, injection molding, extrusion molding, calendering, coating ^ deformed and buckled; the different Process steps are carried out separately from one another or combined with one another, for example gelling and foaming, gelling and deforming or deforming and foaming combined.

The propellant mixture to be used according to the invention can can be added to the vinyl chloride polymer after gelling.

When processing by compression molding, emulsion polymerization or polymerization in microsuspension is preferred manufactured vinyl chloride polymer is used. After mixing, a paste is obtained, which then deforms and pressed under conditions of temperature and time which result in gelling. The molding obtained is after Cooling and demolding either with hot air or with steam or in a hot water or oil bath or by IE radiation, high frequency or ultra high frequency expands.

For processing by extrusion, injection molding and Calendering uses a vinyl chloride polymer that is polymerized in bulk, in suspension, in micro-

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suspension or in emulsion. The viscosity number of this polymer can be high if a soft foam is sought; it must be small if a rigid foam is to be produced.

During extrusion, the mixture is fed into an extruder and the extruded profile is then as specified expands.

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

During calendering, the components are mixed with one another, gelled and deformed, and films or sheets are then placed on top drawn and also foamed as indicated.

Is the processing carried out by coating or brushing with a plastisol, it becomes a vinyl chloride polymer made by emulsion or microsuspension polymerization used. All ingredients are mixed together to form a paste. The gelling and expanding takes place when passing through the coating machine. It can also be coated with powdered mixtures, however in this case, a vinyl chloride polymer prepared by suspension or bulk polymerization is used.

The foams obtained according to the invention can be closed and / or have open cells, depending on the formulation used, processing method and conditions in Frothing. The diameter of the cells and their wall thickness depend on the same parameters,

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It can-be with the aid of the propellant mixture according to the invention manufacture numerous very different foam products, for example:

thin (<5 now) flexible foams with a high density

(> 0.2 g / cm ³ ),

thick (5 to 100 mm) flexible foams with a low volume weight (<0.2 g / cnr),

thick (5 to 100 mm) rigid foams in all possible

Volume weights range (0.025 to 0.85 g / cm ³ ).

The foams produced according to the invention on the The basis of vinyl chloride polymers are used in a variety of ways: 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 further illustrated by the following examples explained.

B is ρ ie 1 1

A plastisol mixer was charged at room temperature with 200 g of polyvinyl chloride, produced by emulsion polymerization, viscosity number 180, determined according to the French standard T 51-013, 52, ^ g urea, 38 _a 8 g adipic acid and 2 g zinc oxide and charged for 15 min. long mixed; thereupon were? Q g of butyl benzyl phthalate; added and mixed for a further 10 min. A viscous paste was obtained with the consistency of a putty »

This paste was in EIAA cylindrical shape with Innendurclime he ss ca 7 and height 1 ca © Ingetoacht mxh and then pressed at 180 ° C under Onea Drucfe of 100 bar ifäkrend 50 "Thereupon

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was cooled to room temperature and kept under the same pressure for 20 minutes.

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

A somewhat soft, cellular product with a tree weight was obtained 0.09 ^

Examples 2 to 4

The procedure was as in Example 1, but the 38.8 g Adipic acid replaced by various dicarboxylic acids in appropriate quantities. ·

The conditions and test results are as follows Table 1 summarized. ■ -

3 TABLE 1

Examples dicarboxylic acids · foams

Type Amount Hardly procured

weight g / cm *

2 Malonic acid 27.6 O, - · 14th soft 3 Succinic acid 31 O, 17th Il 4th Decanedioic acid 68 0, 40 somewhat soft at game 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. Was received a somewhat flexible foam with a weight of 0.24 g / cm

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B e i s ρ, .i e 1 6

Example 1 was replaced with 26.2 g of succinic anhydride of 58.8 g of adipic acid repeated. A flexible foam with a density of 0.1 g / cm was obtained

Examples 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.

TABEL 2 lot
e Foam Procure
Ness Examples Nitrogen derivative of
carbonic acid 52.4
54.4 Space
weight
g / CBK soft
11 Art 0.04
0.12 7th
8th
B ice ρ Biuret ".
Acetylurea
ie 1 9

A mixture was made from:

1000 g copolymer of vinyl chloride and vinyl acetate, containing 15% vinyl acetate units, produced by suspension polymerization, with viscosity number 60 (French standard T 51-015),

50 g tribasic lead sulfate, 3 g dibasic lead stearate ..

The mixture was mixed in a roller mixer at 115 ° 0 for 10 min

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kneaded to gel. Kneading was continued, and a mixture of 160 g of urea and 200 g of adipic acid was added. This was followed by kneading for a further 10 minutes.

The mass was drawn out into films which were allowed to cool on a flat surface. Thereafter, the films were foamed in an oven at 200 ⁰ C for 15 min.

A rigid foam was obtained, the density of which was 0.1 g / cnr.

Example 10

A mixture was produced from: 500 g of polyvinyl chloride, produced by bulk polymerisation, viscosity number 60 (French standard T 51-013) »500 g of copolymer of vinyl chloride and vinyl acetate, containing 15 % vinyl acetate units, produced by suspension polymerisation, 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 kneaded for 10 minutes on a roller mixer at 110 ⁰ C to the Gelieren-. Films were then drawn out and allowed to cool on a flat surface. The films 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 ⁵ .

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Example 11

The following were mixed together:

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,
200 g adipic acid,
50 g ethylene glycol methacrylate,
1 g cumene hydroperoxide,
30 g tribasic lead sulfate and
3 g dibasic lead stearate.

The mixture was kneaded by a roll mill for 10 minutes at 100 ⁰ C until the gelation. A film was then drawn and allowed to cool on a flat surface. The sheet was foamed in an oven at 200 ⁰ C for 15 minutes and crosslinked.

The finished product was a rigid foam with a density in the range of 0.1 g / cm.

The dimensional stability in the heat was measured with a test piece

40 mm 40 mm χ 20 mm measured under a load of 250 g / cm, the temperature was determined ^ at which the thickness of the test specimen had decreased by 5%. This temperature was ⁰

For comparison , a YersucJh. with the same Bezeptur, but without JLthylenglykolmethacrylat tJnd oka © cumene hydroperoxide performed The rigid foam obtained by tree weight O ₃ I g / em ⁵ had a warm-Eornibes-fcäadigksit of only 75 ⁰ C au £ "

a Plastisoinisciier ι-τα ^ & ®Ά "bsi Ssjaat © Hperatiir ni

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/ 600 g polyvinyl chloride, obtained by emulsion polymerization, with viscosity number 180 (French standard T 51-013), 12 g urea, '

15 6 adipic acid and
9 6 Mixture of cadmium octoate and zinc octoate.

After mixing for 10 minutes, 400 grams of butyl benzyl phthalate was added and mixing continued for 30 minutes.

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

PATENT CLAIMS

72XXIV

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Claims (6)

Patent to claims 1. Modification of the process for the production of foams based on vinyl chloride polymers using a nitrogen derivative of carbonic acid and a organic acid-containing propellant mixture.es, wherein in a known manner the vinyl chloride polymer with the Propellants and, if necessary, plasticizers, stabilizers and other customary additives mixed together, the mixture gels, deformed and foams and the nitrogen derivative of carbonic acid the formula 1 ^/ R ¹ - NH - G - K ¹¹ \ 3 X ^R corresponds to wherein X is an oxygen or sulfur atom or the Imino group means R is a hydrogen atom, an alkyl group with less than 6 carbon atoms, an acyl group with less than 5 carbon atoms or optionally with alkyl groups less than 4 carbon atoms substituted carbamyl group p
means R represents a hydrogen atom or an alkyl group less than 6 carbon atoms and R is a hydrogen atom, an alkyl group having fewer than 6 carbon atoms, an acyl group having fewer than 5 carbon atoms, one optionally carbamyl group substituted with alkyl groups having less than 4 carbon atoms ,, or, a saturated aliphatic Ester group with less than 6 carbon atoms is after In tnVL + nyiinni J, _1Tin 9 eBB-n ' Ψ eo UUUUL_1UUUUI 17-e , thereby - 17 - 109810 / M23 characterized in that one is used as an organic acid at least one saturated carboxylic acid containing 3 to 18 carbon atoms, namely an optionally cyano, chlorine, Bromine, alkyl, aryl, aryloxy or chloroaryloxy substituted aliphatic carboxylic acid and / or a corresponding anhydride used. 2. The method according to claim 1, characterized in that the nitrogen derivative of carbonic acid, urea, biuret, thiourea, acetylurea, biacetylurea, iriuret, G-uandidine, lower alkylallophanates, lower alkylcarbamylallophanates, N-methyl-N ^f -acethylurea or H Methyl-N ·, II'-dimethy! Urea is used. 3. The method according to claim 1 or 2, characterized in that the saturated acid is a dicarboxylic acid, especially adipic acid, malonic acid, succinic acid and / or decanedicarboxylic acid used. 4. The method according to claim 1 or 2, characterized in that g e k e η η, that one is a saturated carboxylic acid Monoearboxylic acid, especially propionic acid, is used. 5 «Method according to claim 1 or 2, characterized in that g e k e η η that one is an anhydride according to the acids Claim 3 or 4, in particular succinic anhydride, is used. 6. V method of claim 1 to 5, characterized ^e g ^fe © ⁿⁿ ~ ζ η et calibration that use a Sticksbffderivat, the CaEbamylgruppe substituted with alkyl groups containing less than 4 carbon atoms. T09810 / 2123