DD209841A5 - PVC-CONTAINING COMPOSITION AND METHOD FOR THE PRODUCTION OF POROUS FLUID BASES FROM THIS COMPOSITION - Google Patents

Abstract

1. Dry powdery mixture for preparing foamed flat-shaped PVC-articles in two process steps containing a) emulsion-, suspension-, and/or block polymerisation-PVC, b) one or more foaming agents in an amount of 1 to 10% by weight, based on the PVC, c) utmost 150% additives and/or adjuvants, based on the PVC, d) 1 to 50% of a thermoplastic methacrylic acid ester-copolymer, based on the PVC, characterized by the fact that the component (d) is a methacrylic acid methyl/ethyl/n-butylesterterpolymer the glass transition temperature of which is at most 20 degrees C higher than that of the PVC.

Description

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PVC-containing composition and process for the production of porous sheets of this composition

Field of application of the invention:

The invention relates to a novel PVC-containing composition and to an improved process for the production of porous PVC sheets using this composition.

Characteristic of the known technical solutions?

For the production of PVC sheet structures with foam structure, in practice, the coating method is the most common. The essence of this method is that on a later part of the fabric forming or subsequently removable from a carrier made by emulsion polymerization PVC, foaming agents and other technological aids and additives (eg plasticizers, heat and light stabilizers, fillers, etc.) existing plastisol or plastic gel, then heat-treat the PVC for gelation.

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and the polymer film is formed and the product is oil-foamed in the same or a subsequent step by heat treatment. During foaming, the material is heated to a temperature at which form from the previously added foaming gaseous substances. With the coating technique, uniformly foamed PVC sheets can be produced easily and in high productivity as well as good quality. If several coating heads are used, multilayer PVC sheet structures can be produced with ease in a single operation with the coating technique. The disadvantage, however, that can be processed with the coating technique only produced by emulsion polymerization PVC; From the obtained by suspension or bulk polymerization PVC can - due to the emerging during the polymerization morphology of the polymer - the required for the coating technology liquid, viscous plastisol or plastigel are not produced.

PYC produced by slurry or bulk polymerization can only be fabricated into sheet form by technologies requiring polymer dust as a raw material. Such technologies include, for example, extrusion, calendering, and roll-mill smelting. Purely in the production of PVC sheets of compact cross section, these technologies have been well proven, but their application to produce foamed PVC sheets from slurry or bulk polymerized PVC is encountering difficulties.

The production of fabrics with foam structure by calendering is described in German Offenlegungsschriften Nos. 2,145,026 and 2,616. According to these publications, a web is formed from the dry powder mixture at a temperature which is lower than the foaming temperature, on the calender rolls, and this is foamed to form foam.

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neither passed through the last, heated to Aufschäumungstemperatur roller pair of the calender or treated on another, eich to the calender, heated to foaming temperature roller pair. These methods have the following disadvantages:

the number of foaming agents and processing aids that can be used in this process (for example, plasticizers, fillers, stabilizers, etc.) is very limited; the auxiliaries commonly used in PVC processing make the PVC so sticky at the relatively high temperature required for foaming that the web sticks to the calender rolls. This results in interruptions in the continuous production, the rolls must be cleaned, the quality of the product decreases, and every restart of the calender is associated with considerable loss of time.

Foaming in the material starts even at the lower temperature of the calender rolls, and as a result, the foaming process does not proceed uniformly. The finished track is wavy and of poor quality.

The products made by calendering, extruding or on a fuser mill have the common disagreeable property of being far less dimensionally stable than the products made by the coating technology. This is due to the fact that these technologies exert much greater tensile forces and therefore relax the product in which strong, unbalanced strains have remained. Although cumbersome and time-consuming shrinking processes can reduce this effect, the result is not always satisfactory.

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With the calender or the melting roll mill, no multi-layered products can be produced because the elongation of the individual layers is different. This leads to unsolvable problems with tension formation and foaming in terms of stress compensation. Multilayered products can only be produced by subsequently adhering the separately produced webs. This of course increases the amount of time, labor and equipment.

Aim of the invention;

The aim of the invention is to find a way by which the disadvantages of the processes starting from dry powder mixtures can be eliminated and with high productivity and in a simple manner a single or multilayer PVC sheet structure with foam structure can be produced, its properties exactly the same good or better than the products made by the coating process.

the essence of the invention:

It has now been found that this object can be achieved by mixing, in a certain ratio, a thermoplastic polymer which is compatible with the other components of the system, at the processing temperature, to the dry powder mixture to be processed by extrusion, calendering or on the hot-rolling mill gives an elastic mixture and a glazing temperature (T) which is at most 20 ⁰ C higher, but preferably lower than that of the processed PVC. The addition of this polymer gives a mixture which can be formed into a compact sheet even at lower temperatures, thereby avoiding the partial foaming already occurring during the forming of the web. Furthermore,

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de found »that it is expedient» not to froth the web, which is still compact in cross-section, directly on the calender or the roller mill »but to guide it through a heated device, since in this case the sticking of the PVC to the processing device can be avoided with certainty. This has the advantage that it is also possible to use other excipients and processing materials than those which certainly do not cause any liability. Finally, it has been found that multi-layered products can be produced on the web-forming apparatus (for example, the roll mill) in a single operation, by forming the layer directly contacting the apparatus on or later forming part of the final product removable carrier forms.

Accordingly, the subject of the invention is firstly a pulverulent composition which can be used as a starting material for the production of PVC sheets with foam structure. The composition according to the invention comprises:

by emulsion, suspension and / or bulk polymerization produced PVC,

based on the weight of the PVC 1-50 %, preferably 10-30 %, compatible with the components of the system, at the processing temperature of an elastic mixture resulting thermoplastic polymer whose Glaskungstem-

o is lower than the PVC used,

temperature (T) at most 20 C higher, but preferably

based on the weight of the PVC 1-10 % per se known foaming agent and optionally

based on the weight of the PVC at most 150% per se known and for the production of PVC Plächgebilden with foam structure of conventional additives and / or auxiliaries,

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Although the process according to the invention has been developed primarily to also ensure the processing of suspension or block polymerization PVC into fabrics, there is no obstacle to using as the starting material the emulsion polymerization PVC which can also be processed in coating technology. The K value of the PVC to be processed is between 50 and 80. The PVC types produced by different polymerization processes can also be used as a mixture.

To the thermoplastic polymers contained in the composition according to the invention the requirement is made that they must be compatible with the other components of the system that they form an elastic mixture at the processing temperature with the other components. These requirements are met in particular those thermoplastic polymers whose T-value is at most 20 ⁰ C higher, but preferably lower than that of the PVC to be processed.

Suitable thermoplastic polymers are, for example, the following:

Olefin polymers and copolymers, e.g. Polyethylene, polypropylene, ethylene-propylene copolymer, etc.,

Styrenic polymers and copolymers, for example, poly-otmethylstyrene, acrylonitrile (butadiene) styrene, methyl methacrylate (butadiene) styrene and methyl methacrylate-acrylonitrile / butadiene / styrene copolymers,

Acrylic ester and methacrylate ester polymers and copolymers, e.g. Polybutyl acrylate, polymethyl methacrylate, etc.,

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Vinyl chloride copolymers, terpolymers and graft polymers, for example the copolymers, terpolymers and graft polymers formed with olefins and diolefins,

the homopolymers and copolymers of the vinyl esters of carboxylic acids having 2-20, preferably 2-4, carbon atoms, for example polyvinyl acetate, polyvinyl propionate, polyvinyl butyral, polyvinyl stearate, etc.,

Polyνinylather,

polyvinyl halides other than PVC,

modified olefin polymers and copolymers, for example chlorinated polyethylene, chlorinated ethylene-propylene copolymers, etc.,

Homo- and copolymers of mono- and diesters of unsaturated dicarboxylic acids.

As foaming agents, the solid, inorganic or organic compounds conventionally used for the production of PVC foam products are embossed, which are not decomposed at the temperature of the formation of the sheet, but develop gas at the foaming temperature. Since the surface formation (for example on the calender or a roll mill) at temperatures of 80-160 ⁰ C and the foaming is generally carried out at 160-200 ⁰ C, foaming agents must be used, the gas evolution only above 80-160 ⁰ C uses. Suitable foaming agents are, for example: sodium hydrogen carbonate, N, N ^f -Dinitrosopentamethylen tetramine, diphenylsulfone-3,3'-disulfonylhydrazide, Diphenyloxyd-4,4'-sulfonylhydroxyd and azodicarbonamide.

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The foaming agents may be used together with the promoters (the decomposition regulators) commonly used to make PVC foam products. Examples of promoters are embossed barium, cadmium, zinc and lead salts and oxides; their amount, based on the weight of PVC, is generally 0.1-3.0 %. When the foaming agents are used together with promoters, it must be ensured that the gas development einset'zt only above 80 to 160 ⁰ C.

If appropriate, the additives and / or auxiliaries customary in the production of PVC foam products may also be added to the composition. Their amount is based on the weight of PVC at most 150 %.

As optionally usable additives and / or auxiliaries, for example, the following are in embossing:

a) heat stabilizers, for example the neutral or basic barium, calcium, cadmium, zinc and lead salts of stearic acid, ricinoleic acid, oleic acid or lauric acid, organic lead compounds (mono- and dialkyl compounds, alkylaryl compounds, alkylmercaptoble compounds, tetraalkyl or tetraaryl compounds). The heat stabilizers are generally used in an amount of 0.3-3.0 % based on the weight of the PVC.

b) light stabilizers, for example 2-hydroxy-4-n-octyloxybenzophenone, 2-oxy-4-methoxy-benzophenone and 2- (2-hydroxy-5-octylphenyl) -benzotriazole. Their amount, based on the weight of PVC, is generally 0.1-2.0 % »

c) lubricants, for example fatty alcohols, aliphatic carboxylic acids and oxycarboxylic acids with more than 10 carbon atoms, the esters and amides of these carboxylic acids,

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Waxes, etc. The amount of lubricants, based on the amount of PVC, is generally 0.1-3.0 %.

d) Fillers, for example natural minerals (sulfides, sulfates, carbonates, oxides, mineral fibers), organic fiber materials, other organic fillers. These are based on the weight of the PVC, generally used in an amount of 5-50 % .

e) plasticizers, for example the esters of mono-, di- and tricarboxylic acids having 2-12 carbon atoms (for example dibutyl phthalate, dibutyl adipate, benzyl butyl phthalate, dioctyl sebacate), triaryl phosphates (for example tricresyl phosphate), sulfonic acid esters (for example the phenyl and benzyl esters of alkyl sulfonic acids having 12-18 carbon atoms), epoxidized oils, plasticizing polymers (for example, polysebacates, polyadipates, polyphthalates), etc. The plasticizers are generally used in an amount of 20-80 % by weight of the PVC.

f) pigments, for example cadmium red, cadmium yellow, iron oxide red, bituminous yellow, titanium dioxide, carbon black, phthalocyanine blue, phthalocyanine green, anthraquinone blue, anthraquinone red, etc. Based on the weight of the PVC, in general 0-8 % pigment is used.

The invention furthermore relates to a process for the production of single-layer or multi-layer PVC fabrics with a foam structure. According to the process of the invention, a sheet of compact cross-section is formed from the dry powder mixture of the above-defined composition at 80-160C on the extruder, calender, or melt roll mill, if desired, forming a part of the finished product later from this later separable support or on another polymeric web, desired

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if itself is formed one or more additional polymer layers on the compact fabric, and the one obtained in this way or multi-layered fabric is - optionally after a known pattern-forming surface treating - through a heated at 16O-210 ⁰ C warming apparatus and foamed there.

The sheet is formed in a conventional manner by extrusion, calendering or on the Schmelzwalzenstuhl. Due to the special composition of the dry powder mixture, primarily because of the polymer contained in it, the formation of the sheet can be carried out at temperatures which are 20-100 C below the usual calender temperatures. As a result, premature start of foaming can be avoided with certainty. Microscopic material investigations have shown that in the section of the formation of the sheet, the thermoplastic polymer is at least partially melted and its melt surrounding the still solid or just to start melting PVC particles. The complete melting of the PVC particles generally takes place together with the gas formation. In this phase of production, the molten PVC particles and the melt of the polymer form a homogeneous mixture, in which the optional additives (pigments) are homogeneously distributed. The fact that the PVC particles melt completely only when foaming is of great importance for the formation of a fine-pored, closed-cell foam.

When a multi-layered product is to be produced, the first (i.e., the layer directly contacting the device) is formed on a later part of the product forming or subsequently removable carrier. As part of the product,

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For example, the knitwear and knitwear customary in artificial leather production, as well as woven textiles, felt, glass fiber fabric, etc., come into question. As the releasable support, steel sheet or surface-treated paper, etc. may be used. The multilayer sheets produced according to the invention contain at least one layer of foam structure. The following examples serve to arrange the different layers:

Foam layer / foam layer (different), compact layer / foam layer

compact layer / foam layer / compact layer (sandwich).

If the multilayered products are to be produced on the calender or on the fused-roll mill, then the powder mixture of the following layer, melted between the fusing rolls, is applied in the form of a film to the first layer applied to the carrier. This operation can be repeated as often as desired. From the last roller a product is withdrawn whose structure is still compact in all layers.

If the multilayer products are to be produced with the extruder, the following layer is directly extruded onto the first layer on the carrier. This process can be repeated as often as desired. The individual layers are pressed together between roller pairs. From the last roller a multi-layered, still completely compact product is removed.

If desired, the monolayer or multilayer sheet removed from the roll apparatus or the extruder may be subjected to patterning surface treatment. This surface treatment may be, for example, by applying to the surface of the foam to be foamed

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Layer in a certain pattern the speed of foaming affecting substances applies. In the foaming section, the sites that have been treated foam at a different rate than the untreated areas, ie, the expansion of the material is different, and in this way structuring of the surface is achieved. This type of pattern formation and the substances suitable for it are described in numerous publications (GB-PS 1,117,983, US Pat. Nos. 3,293,108, 3,293,094 and 3,545,057). As substances with which d ± ß the foaming rate can be affected, for example, trimellitic acid, oxalic acid, fumaric acid, and Cadmiumactoat lead phthalate may be mentioned.

In the process according to the already cited DE-OSs 2,145,026 and 2,616,083 (foaming directly on the calendering device), there was no possibility for patterning by pretreatment. By contrast, with the method according to the invention, since the foaming takes place separately after the formation of a web in a heating device, products with a patterned surface can be produced in a simple manner.

In the last step of the method the removed from the sheet forming apparatus, optionally patterned single- or multilayer compact yet have all the layers of sheet material is passed through a heated to 160-210 ⁰ C device. The effect of heat forms gas in the layers containing foaming agents, and the desired foam structure is formed.

Palis no pattern-forming pretreatment was made, the foamed Plächengebilde can be surface-treated in the usual manner with artificial leather.

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The dimensional accuracy and surface quality of the product obtained correspond to the products produced by the coating technology. With regard to the dimensional stability, the foam structure and the surface quality, the products produced according to the invention far outperform the fabrics produced using the conventional calendering technique.

Ausführungsbeiepiele;

The invention will be explained in more detail with reference to the following examples, but is not limited to these examples.

example 1

A dry powder mixture suitable for processing on the extruder is made from the following components:

Suspens ion PVC: 100 wt . Parts Vinyl chloride-vinyl acetate copolymer: 20 It glycerol: 0.4 Il dioctyl: 40 Il polyethylene wax: 0.4 It Bariumcadmiumlaurat: 2 •1 azodicarbonamide: 2 11 Eisenoxydrot: 4 It

The components are homogenized, filled into the hopper of the extruder and extruded at 155 ⁰ C. The resulting extruded sheet is passed at a speed of 10 m / min through a heated to 190 ⁰ C heater. A PVC surface with foam structure is obtained, the parameters of which are as follows:

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Grammage: 400 g / m ² Thickness: 1.2 mm Tensile strength: 150 N / 50 mm elongation at break: 120 * · Example 2

The following components are used to prepare a dry powder mixture suitable for processing on the calender:

I II

Suspension PVC: 100 100 parts by weight

chlorinated polyethylene: 10 20 "

Dioctyl phthalate: 50 50 "

Barium cadmium laurate: 2 2 "

Glycerol monostearate: 0.6 0.6 "

epoxidized soybean oil: 2 2 "

Paraffin: 0.2 0.1 "

Iron oxide yellow: 4 2

Azodicarboamide: - 3 "

The dry powder mixture II is placed in the nip of the heated to 160 ⁰ C calender and formed by passing through the four rolls (the temperature of 150, 155 »16O and 160 ⁰ C) into a compact sheet. Then, a compact sheet is also produced from the powder mixture I under identical conditions. The first fabric is combined with a textile support when it is removed from the last roll. The second sheet is combined with the first film on the textile carrier. The resulting composite is passed through a heated to 190 ⁰ C device. The finished composite consists of a carrier, a compact and a foamed layer and has the following technical parameters:

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Thickness: 1.5 mm tensile strength 600 N / 50 mm elongation at break: 6 %. Example 3

From the following components, a dry powder mixture suitable for processing on the extruder is prepared;

Suspension PVC: 90 parts by weight

Emulsion PVC: 10 "Polyacrylate: 5"

Dioctyl phthalate: 60 "glycerol monostearate: 0.3"

Paraffin: 0.5 "

Dibutylblei-di-

(isooctyl maleate) 1.0 "

Azodicarboamide: 5 "

Iron oxide red: 4 "

The components are homogenized and extruded at 160 ^° C. The resulting extruded surface is combined with a textile carrier. The composite is passed through a device heated to 210 ^° C. at a speed of 12 m / min. The supported PVC foam product has the following parameters:

Square meter weight: 500 g / m

Thickness: 2.0 mm

Tensile strength: 500 N / 50 mm

Elongation: 6 %.

- 16 Example.4

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100 Ge . Parts 20 ti 40 ti 20 It 1.5 • I 1.5 ti 0.5 •1 0.5 It 3.0 It 4.0 "t

The following components are used to prepare a dry powder mixture suitable for processing on the calender:

Suspension PVC:

Methacrylate-butadiene-styrene terpolymer:

Dioctyl phthalate: benzyl butyl phthalate: epoxidized soybean oil: barium cadmium laurate: barium stearate: stearic acid: azodicarbonamide: titanium dioxide:

The mixture is processed according to Example 2 on the calender. The fabric removed from the last roll is combined with a paper backing. The surface of the film is subjected to patterning treatment. The material prepared in this way is passed through a heated to 190 ⁰ C device. A patterned PVC sheet provided with a paper support is obtained having the following properties:

Square meter weight: 500 g / m

Thickness: 1.5 mm

Tensile strength: 300 N / 50 mm

Elongation at break: 4 % ·

Example 5

A dry powder mixture suitable for processing on the calender is made from the following components:

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Sus pensions PVC: 100 Parts by weight Butadiene-acrylonitrile copolymer: 30 Il dioctyl: 30 • I benzyl: 10 Il C.G-C.G fatty alcohol mixture: 0 3 " polyethylene wax: 0 2 " calcium carbonate: 15 Il Diethyl-lead-bis (2-ethylhexyl thioglycolate): 1 It Azodicarbonamide s 2 "I titanium dioxide: 4 Il

From the dry powder mixture at 150 ⁰ C, a sheet with a compact structure is produced. The removed from the last roller fabric is combined with a textile carrier. Subsequently, in a manner known per se from dry soft PVC powder at 190 ⁰ C, a compact film is produced. This is taken from the last roll and combined with the previously prepared composite. The new composite is passed through a heated to 210 ⁰ C heater. The product obtained has a compact and a foamed layer and has the following parameters:

Square meter weight: 700 g / m

Thickness: 1.5 mm

Tensile strength: 600 N / 50 mm

Elongation: 6 %,

Example 6

The following components are used to prepare a dry powder mixture suitable for processing on the calender:

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100 wt . Parts 50 ti 35 I! 15 1" 0.5 • t 0.4 H 0.5 tt 1.0 ti 10.0 tt 2.0 t " 8.0 tt 1.5 tt

Suspension PVC:

Vinyl chloride-ethylene-vinyl acetate copolymer!

dioctylphthalate; benzyl:

partial fatty acid ester of glycerin:

Paraffin; Stearic acid: Mg-Zn-laurate: calcium carbonate: spoxidized soybean oil: Aζod i carbonamid: carbon black:

Aua the mixture is prepared, a provided with a textile support compact Plächengebilde by the method described in Example 5 way and with another compact film united (s. Example 5) · The resulting composite is passed through a heated at 190 ⁰ C heater. A PVC sheet consisting of a compact and a foamed layer and a textile support is obtained, the parameters of which correspond to those given in Example 5.

Example 7

The following components are used to prepare a powdery mixture suitable for working up on the extruder:

Suspension PVC:

Ethylene-vinyl acetate copolymer:

Dioctyl phthalate: glycerol monooleate: paraffin: Ba-Cd stearate:

100 weight . Parts 30 tt 40 tt 0 , 5 tt 0 , 4 It 1 , 0 tt

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Azodicarbonamide: 1.5 parts by weight

Silicon dioxide: 1.0 "

Soot: 5.0 "

The mixture is extruded at 120 ^° C. The resulting extruded sheet is combined with a textile carrier. The thus provided with a carrier compact film is heat treated in a heated to 190 ⁰ C heater. The foamed, supported PVC sheet has the following quality parameters:

Square meter weight: 500 g / m

Thickness: 1.5 mm

Tensile strength: 500 li / 50 mm

Elongation: 6 %.

Claims (4)

- 20 claim for invention; 242849 5 1. PVC-containing composition for the production of porous fabrics, characterized in that they by emulsion, suspension and / or bulk polymerization produced PVC, based on the weight of the PVC in an amount of 1-50%, preferably 10-30%, compatible with the components of the system, forming at the processing temperature an elastic mixture thermoplastic polymers whose vitrifying temperature (T) is at most 20 ⁰ C higher, but preferably lower than that of the PVC used, based on the weight of the PVC 1-10 % per se known foaming agent and optionally At least 150 % per se of the composition of the PVC, which is known per se and contains additives and / or auxiliaries customary for the production of PVC structures having a foam structure. 2. Composition according to item 1, characterized in that it contains as a thermoplastic polymer vinyl polymer or vinyl copolymer or optionally halogenated polyolefins. 3. Composition according to item 1, characterized in that it contains foaming agents which develop per se or together with promoters at temperatures of 16O C or more gases. 4. A process for the preparation of single or multilayer PVC Plächengebilden with at least one porous layer, characterized in that the dry 242849 5 Powder composition according to items 1 to 3 at 80-160 ⁰ C, optionally on a later part of the finished product forming or subsequently removable from the carrier by extruding, calendering or on the Schmelzwalzenstuhl to form a compact sheet, if desired on the compact sheet with the surface-forming Device further polymer layers and the resulting single or multilayer sheet, optionally after a pattern-forming surface treatment, in a heated to 160-210 C heater heats up.