Combined three-component material and method of making the same

The invention also relates to a process for the production of a composite material consisting of polyvinylidene fluoride and a non-polyvinylidene fluoride-bonded thermoplastic polymer, characterized in that polyvinylidene fluoride, polyalkyl methacrylate and a non-polyvinylidene fluoride-bonded thermoplastic polymer are coextruded, wherein the polyalkyl methacrylate serves as an intermediate binder and the streams of all three components are connected to each other at the end of the extruder at the end of the extrusion tube maintained at a temperature in the range of 180 to 280 ° C.

The present invention relates to a composite material consisting of polyvinylidene fluoride, i.e. a polymer referred to hereinafter as PVF₂ and a thermoplastic polymer not bonding (incompatible with PVF₂as well as a method for producing this material by coextrusion.

The technique of coextrusion of thermoplastics is known and is described in particular in the "POLYMER PLASTICS TECHNOLOGY AND ENGINEERING, Vol. 3, pp. 49 to 68: “Co-Extruded Films - Method and Properties” by JE Guillotte.

In general, three methods for co-extruding thermoplastics from a plurality of conventional extruders are known, the number being the same as the number of extruded polymers. The first method consists in separately extruding the individual polymers and joining them together as they emerge from the extrusion die.

In the second method, thermoplastics from at least two extruders are fed to a single extruder, the extruder having as many channels as the extruders and hence the extruded polymers.

The streams of the individual polymers join at the edges of the extrusion die, i.e., almost immediately before leaving the extrusion die. In a third method, polymers from a select number of extruders are fed to a flow distributor in which they join to form a single stream which is fed to the extruder die. In these methods, the speeds at which the streams exit the extruders generally provide a means of controlling the relative thicknesses of the extruded streams.

Although many polymers can be extruded together, PVF cannot be coupled using this technique₂ with other polymers. This is due to the fact that PVF₂ it does not associate (is incompatible) with other polymers, and also the well-known fact that fluorinated resins are very difficult to adhere to most thermoplastic polymers.

With this difficulty in combining PVF₂ other thermoplastics can also be encountered when working with a laminating technique which involves two preformed films, one of PVF₂, and the other of any selected thermoplastic, adheres to each other to adhere to each other under the action of pressure and heat. Attempts have also been made, but unsuccessfully, to laminate a preformed PVF film₂ with a film of polyvinyl chloride, polystyrene, polyomethyl methacrylate and acrylonitrile-butadiene-styrene copolymer immediately as it leaves the extruder, i.e. in a practically molten state. Even under these conditions, the two polymers are easily separated from each other after cooling.

In the prior art, if PVF is to be combined₂ with another thermoplastic that is not bondable to PVF₂, adhesives must be used. The disadvantage of this method is that it involves three stages:

preparing a PVF film₂, preparation of foil from thermoplastic, gluing and pressing foils together.

These processes are impractical, slow, generally requiring the use of solvent-based adhesives that are difficult to remove and do not allow the obtained composite material to be used immediately after manufacture due to the time required to dry the adhesive. In addition, the obtained composite material is not uniform, since the interfaces are still exposed to phenomena which may cause disintegration of the individual components. Therefore, it can be said that gluing does not achieve a uniform composite material, but in this process the thermoplastic materials merely stack together to form a final heterogeneous product.

These drawbacks are overcome by the invention. The invention provides the possibility of obtaining a new, uniform, truly combined material of a homogeneous composition in which the individual elements are firmly connected to each other. This new composite ternary material consisting of one outer layer of polyvinylidene fluoride (PVF)_andAnother layer of thermoplastic polymer not bonding to polyvinylidene fluoride is characterized in that the intermediate tie layer is a C 1 -C 3 alkyl alkyl methacrylate, alone or in combination with another thermoplastic polymer present in an amount of at most 30% by weight.

Another thermoplastic polymer optionally used in combination with a C 1 -C 3 polyalkyl methacrylate is a polymer selected from fluorinated thermoplastics, chlorinated vinyl polymers, styrene polymers, polycarbonates, polyurethanes, polyether ethers, copolymers styrene with acrylonitrile and grafted acrylic elastomer, copolymers of acrylonitrile with butadiene and styrene, polyacrylic esters, copolymers of acrylic esters with vinyl derivatives and copolymers of methyl methacrylate with vinyl chloride, vinyl acetate, methyl acrylate, styrene, isobutylene, acrylic acid, acrylonitrile or methacrylonitrile.

The interface between polyvinylidene fluoride and polyalkyl methacrylate and between the incompatible thermoplastic polymer and polyalkyl methacrylate consists of an alloy that can be obtained, for example, by mixing the components in the molten state, which means that the combined material can be considered as uniform and homogeneous as opposed to the so-called combined material having a heterogeneous composition which can be obtained by in which roz^hframe, ^ktIn this case, the eras have no transition zone, they are clear, evident and vulnerable. An article of the invention may also be defined as a composite material consisting of three components, made by combining a polyalkyimethacrylate with polyvinylidene fluoride and a polymer.^torylmetha^torylate with thermoplastic ^pO^lymerely do not associate with polyvinylidene fluoride, which material has at least one outer layer of polyvinylidene fluoride. and one layer of thermoplastic polymer not bonding to polyvinylidene fluoride. The outer layer or layers of polyvinyl chloride^yland^denf^anduor^idu are u ^toom^binovan^éhThe material according to the invention is usually free of polyalkyl methacrylate acting as a binder. This is understandable if sl has polyvinytideiifteorte on^povrc^hu po^drže^t all its own properties.

For the most part, the composite material according to the invention usually has only one outer layer of polyvinylidene fluoride, the second outer layer of which is a thermoplastic polymer not bonding to polyvinylidene fluoride. However, the thermoplastic polymer does not associate with the polyvinylidene fluoride may constitute an attachment layer for the other material. It is therefore possible for the combination material according to the invention that its two outer layers consist of polyvinylidene fluoride in this connection sequence of the following three elements:

polyvinylidene fluoride - polyalkyl methacrylate - thermoplastic polymer not based on polyvinylidene fluoride - polyalkylmethacr^ylat - pol^yvin^yl^iden^fluor^id. Accordingly, according to the invention, a "layer of polymer not bonding to the polyurethane fluoride" may mean both an outer and an inner layer.

An article of this type, which may take any form customary in thermoplastics, such as tubes, sleeves, profiles, foils and sheets, and the sheets and sheets may be further re-formed by known techniques such as press forming ^tE^plem silenced mate^lá·^lat^, it is very advantageous because it has at least one outer layer which is weatherproof and which generally has all the properties of the polyvinylidene fluoride and another layer characterized by mechanical properties and orally all the properties of the inherent thermoplastic polymers not associated with the polyvinylidene fluoride, however, it is in the form of a uniform and homogeneous material.

The material according to the invention is very advantageously obtained by coextrusion, which is very surprising in view of the notorious difficulty of forcing polyvinylidene fluoride to adhere to the thermoplastic polymer. It has been found that when pdyalkyl methacrylate is extruded together with pcl^yvinylidene fluoride and a non-adhering thermoplastic material such that the polyalkyl methacrylate is disposed. between the two polymers, a combined operation is obtained in a single operation which can be used immediately and in which all the individual layers are firmly bonded to one another.

^pre^dmět v^yn^álCutting is therefore a method of manufacturing a composite material consisting of pcl^yvinylidene fluoride and a thermoplastic polymer not associated with polyvinylidene fluoride, the method comprising:^, that together in^ytla^Cpol^yvin^ypolyphenylmethacrylate and the thermoplastic polymer do not associate with polyvinyldene fluoride, wherein the polyalkylmethacrylate serves as an intermediate binder and streams. All three components, when exiting the extruders, are joined together at the latest at the end of the extruder, maintained at a temperature in the range of 180 to 280 ° C.

Although all pclyvinylideneflucrid^y provide satisfactory results, best PVF results₂ having an apparent viscosity range at 200 ° C such that - at least two velocity gradients listed in the table below - have an apparent viscosity falling within the range between the two extreme apparent viscosity values.

^ adíent r^yC^htost^and sec¹ values ​​of apparent viscosity in Pa.s minimum maximum

3,543

11,811,8

35,41,1

1180,65

3540,39

11810,23

<td>X</td><td> 10³</td><td> 20,0</td><td>X</td><td> 10³</td>

<td>X</td><td> 103</td><td> 9,3</td><td>X</td><td> 10³</td>

<td>X</td><td> 103</td><td> 4,7</td><td>X</td><td> 10³</td>

<td>X</td><td> 10³</td><td> 2^,1</td><td>X</td><td> 103</td>

<td>X</td><td> 103</td><td> 1,0</td><td>X</td><td> 103</td>

<td>X</td><td> 10³</td><td> 0,45</td><td>X</td><td> 103</td>

The apparent viscosities are measured in a known manner by a capillary rheometer with phlelene ^to Rablnowhchov ^toore^towhose ^pfor non-Newtonian liquids.

Although considered generally, the thickness of the PVF layer is not₂ importantly, it is advantageous for economic reasons to produce a combined material^ěhlayer ^pW₂ it is in the range of 10 μηι to several tenths of mm.

In addition, polyvinylidene fluoride means not only a homopolymer but also copolymers containing at least 70% by weight of why. PVF₂or mixtures of PVF2 with other polymers.

The polyalkyl methacrylate is preferably polymethyl methacrylate (PMMA) whose viscosity in the molten state falls within the viscosity range of commercially available polymethyl methyl acrylates, and the viscosity may optionally be adjusted using known means to suit the desired viscosity, for example by mixing with a small amount of filler or other. % of the polymer, but such that the mixture contains at least 75 wt.% of polyalkyl methacrylate.

Furthermore, it has been found that the quality of polyalkyl methacrylate a ^pO^eventand^dě t^{éž p}olyvin^yThe lidene fluoride should be selected in accordance with the viscosity of the non-PVF non-thermoplastic material₂, in the molten state. Excellent results are obtained with viscosities of polymethyl methacrylate, measured at 200 degrees Celsius, in the range below for the appropriate velocity gradient. However, the viscosity need not be limited to these values ​​since it can be adjusted depending on the extrusion temperature.

<td>^Gradient rychtostf p^_1</td><td>^hO^dseemingly minimal note</td><td>viscosity in Pa.s maximum</td>

<td> 3,54</td><td>10.0 x 103</td><td> 50^,0 ^x 10³</td>

<td> 11,81</td><td>5.0 x 103</td><td>28.0 x 103</td>

<td> 35,4</td><td> 2^,5 ^χ 10³</td><td>15.0 x 103</td>

<td> 118</td><td>1.3 x 10</td><td>8.0 x 103</td>

<td> 354</td><td>0.7 x 103</td><td> 5^,0 ^x 10³</td>

<td> 1181</td><td> 0^,35 ^x 10³</td><td>3.0 x 103</td>

It is also possible to add to the polyalkyl methacrylate a^les^pOⁿ one ^dal^š termo^ppolymers, but provided that the blend of polyalkyl methacrylate with a thermoplastic polymer contains at least ³⁰ % wt^yalk^ylmethakr^yláhere. The polymer added to the polyalkyl methacrylate may be selected from the group consisting of:^ypolymers, styrene polymers, polycarbonate, polyurethanes, poles (esters-ethers, ^kickedstyrene with acrylonitrile and grafted acrylic elastomer, acrylonitrile-butadiene-styrene copolymer, polyacrylic esters such as polymethyl acrylate, polyethylacrylate or polybutyl acrylate, or ^toopo^lymer^y these acres^yesters with, for example, vinyl derivatives or alkyl methacrylate copolymers with, for example, vinyl chloride, vinyl acetate, methyl acrylate, styrene, isobutylene, acrylic acid, acrylonitrile and methyl acrylonitrile.

The thickness of the polyalkyl methacrylate is adjusted, as necessary in individual cases, in the range of several μπι to 200 μη. Generally speaking, it is not advisable to work with greater thicknesses due to the role that polyalkyl methacrylate would play in the mechanical properties of the entire composite material.

The thermoplastic polymer not associated with PVF2 may be, among others, a chlorinated vinyl polymer such as polyvinyl chloride or polyvinylidene chloride, a styrene polymer such as polystyrene or stiffened polystyrene, polycarbonate, polyurethane, a styrene graft copolymer with acrylonitrile and acrylonitrile copolymer or acrylic elastomer copolymer styrene. This layer of thermoplastic polymer can have any poured thickness, typically from a few tens to several mm. The thermoplastic polymer may contain fillers, plasticizers, stabilizers, colorants or other conventional additives.

Equipment used for the production of combined^Ematerial ^pO^dlev^yn^álezu^, it consists of extruders, a die, and preferably a flow distributor, which device is all of the usual type commonly used in the art of coextrusion of thermoplastics. The thickness of each of the layers is controlled according to the feed rate of each of the extruders.

^Pro ^atheadboards of^pSat^bu podie v^yn^álezu has ^bThe temperature of the discharge nozzle is between 180 and 280 ° C, which depends on the materials to be extruded together. Operating temperatures^h machines are like me^to They are generally used to separately extrude individual polymers.

It is recommended to ensure a satisfactory final cohesion of the three polymers. ^provádět s^polečn^E in^ytland^Cov^andm of this · three ^pol^yflow and^by se ηater^iály, odmázeje c^and from excavating machines with the highest values^poz^dat the edges of the extrusion die. In some cases^pand^dec^h nern (saline)^držnos^t still ^completon^, and ^pTherefore, a is preferred^{by p}rou^{dy P}VF², thermoplastic and polyalkyl methacrylate, leaving the extruder, proceeded together, touching each other before reaching the extrusion die edges. In this^eventand the city has been involved with them21990

<img file="CS219907B2_D0001.tif" />

how many channels the current distributor should be positioned between the outlets of the extruder and the single-channel discharge nozzle.

In a variation, using co-extrusion technology with at least three extrusion machines, a combined material having the following three components can be obtained:

PVF₂ - polyalkyl methacrylate - thermoplastic polymer not associated with PVF₂ - - polyalkyl methacrylate - PVF₂.

The following examples illustrate the invention.

The viscosity is measured with an INSTRON Model 3211 capillary rheometer having a capillary length of about 50.8 mm with a nozzle diameter of about 1.27 mm.

Example 1

Three SMTP - KATFMAN extruders are used, the first of which comprises a degassing device having a diameter equal to 120 millimeters and a worm having a length equal to 33 times its diameter. It is used to extrude acrylonitrile-butadiene-styrene copolymer (ABS), while the second extruder has a diameter of 50 mm (SUPER - 2 x 50) and is used to extrude polymethyl methacrylate [PMMAJ. A third extruder with a diameter of 40 mm is used to extrude PVF₂.

From these three extruders, the individual streams arrive at a cylindrical distributor which is rigidly connected to a conventional flat die, providing a sheet having a thickness of approximately 4 mm, followed by a calender and a conventional extruder for extruding the sheets.

UGIKRAL SF 10 436 is used as acrylonitrile-butadiene-styrene copolymer, ALTULITE-2710 is used as polymethyl methacrylate and FORAFLON 1000 HD as polyvinylidene fluoride.

The viscosity of the acrylonitrM-butadiene-styrene copolymer, measured at 220 ° C, was 7.5 x 10³ Pa.s at a speed gradient of 5.6 s¹ and 1.0 x 10³ at 2 s' gradient¹. The viscosity of polymethyl methacrylate, measured at 200 ° C, is 11.0 x 10³ Pa.s at a speed gradient of 5.6 s'¹ and 1.4 x 10³ Pa.s at a gradient of 2 s^_1.

Finally, the viscosity of the polyvinylidene fluoride measured at 200 ° C is 14.1 x 10³Pa.s, and 0.88 x 10³ Pa.s at 3.5 s ~^{: l}, respectively. 354 s¹.

Temperatures at which the extruders are heated range from 190 to 210 ° C for acrylonitrile-butadiene-styrene copolymer, from 180 to &lt;200 ° C for polymethyl methacrylate and from 180 to 220 ° C for polyvinylidene fluoride.

The temperature of the flow distributor and extrusion die is 210 ° C. The leaf comes between the brewing calender_? heated to 80 ° C.

The total amount of material produced is approximately 300 kg / h. The quantities supplied by the three extruders are controlled to give a resultant composite material comprising a 4 mm thick acrylonitrile butadiene styrene copolymer , a 30 mm thick polymethyl methacrylate and a 100 mm thick polyvinylidene fluoride.₍um. These three. The layers are perfectly aligned with each other as soon as they exit the die. Upon cooling, the combined material of a homogeneous composition is obtained, one surface consisting of polyvinylidene fluoride, while the other consisting of acrylonitrile butadiene styrene copolymer.

Example 2

Using a flow distributor to obtain a five-layer material at the exit of the extruder die, the procedure described in Example 1 is repeated to obtain - using the same polymers and the same extruders heated to the same temperatures - a combined sheet consisting of a 75 μπι layer of polyvinylidene difluoride, a 50 μΐη layer of polymethyl acrylate, a 3 millimeter thick acrylonitrile-butadiene-styrene copolymer layer, a layer of polymethyl methacrylate with a thickness of 50 μΐη and finally a layer of polyvinylidene fluoride with a thickness of 75 μΐη, respectively. The combined material produced consists of five layers which are perfectly matched to each other. Upon cooling, a combined homogeneous composite material having both outer surfaces of polyvinylidene fluoride is obtained while its center consists of acrylonitrile-butadiene-styrene copolymer.

Example 3

For extrusion of polyvinyl chloride (EKAVYL SL 66) a twin screw extruder KESTERMANN К 107 is used, for extrusion of polymethyl methacrylate (RESARITE KOX 125) an extruder STMP with a diameter of 30 mm is used and extrusion of polyvinylidene fluoride (FORAFLON 4000 HDU) 40 mm.

Of these three extruders, the individual streams go to a flow distributor which is rigidly connected to the tube extrusion head. The equipment is complemented by a conventional vacuum forming machine and a drawing line.

The three polymers are coextruded at their normal extrusion temperatures, i.e. 160-200 ° C for polyvinyl chloride, 180-200 ° C for polymethyl methacrylate, and 180-200 ° C for polyvinylidene fluoride. The temperature of the extruder head and flow distributor is maintained in the range of 195 to 200 ° C.

The product is a tube having an outer diameter of 50 mm, formed of a layer of polyvinyl chloride of approximately 3 mm thickness, of a layer of 219907 lymethylinethacrylate with a thickness of approximately 50 µm and an inner layer^ypol^yIn m^ylidenfluoride of Mushroom ^atbli^ofNo ^{75 μ}ΐη in that order. The three polymers are in the form of a combined material with a homogeneous uniform composition.

Example. 4

All three extruders of Example 3, terminated with a flow distributor and a tube extrusion head, were used. The apparatus also includes a conventional bottle making apparatus by extrusion and blow molding, by which the three polymers can be coextruded and blown together.

Polyvinyl chloride [EKAVYL SK 55B] is introduced into the first extruder, ^do a second polymethyl methacrylate (RESARITE KOX 125) and a third polyvinylidene fluoride (FORAFLON 1000 HD). The temperatures in each extruder, respectively, are: 160 to 180 ° C, 180 to 190 ° C, and 190 to 200 ° C; the flow distributor and outlet nozzle are maintained at 190 ° C.

^Zí'with^ká so together in^ytlaen^{á b}aňto (^pre^dwhich is blown in a conventional manner to obtain a bottle. The three extruders are connected to the delivery^dčč ^prou^dsuch that the bottle produced has an inner layer of polyvinylfluoride having a thickness ^pŘ^iblnormally 100, am, an intermediate layer of polymethyl methacrylate with a thickness of approximately 80 μΐη and^š layer of ^pol^yvin^ylc^hlsteed^idat a thickness of about 0.8 mm.

The three layers of the bottle produced are perfectly aligned with each other as they exit the extrusion head. After cooling, the bottle has the appearance of a combined material with a homogeneous uniform composition.

Example 5

It works with three extruders (SMTP - KAUFMAN), of which the first o · diameter ¹²⁰ mm ^lengthce rovn^EA 33 times the diameter provided with a degassing apparatus is used to extrude acrylonitrile-styrene-styrene copolymer, a second 50 mm diameter (Super 2 xx 50) for a mixture of 40 parts by weight of polymethyl methacrylate with 30 parts by weight of polyvinylidene fluoride and 30 parts by weight of acrylonitrile-buaa.^dand a third 40 mm diameter for extrusion of polyvinylidene fluoride.

These three extruders deliver currents to a single cylindrical flow distributor^dů na^pojen^ého na b^ěžstraight expressing nozzle for the production of a plate with a thickness of approximately 4 mm, followed by a calender and^dtahovac^and hnto, spectacle at v^yUačov ^ desek.

AND^toThe rylonitrile-buaadiene-styrene copolymer is UGIKRAL SF 10 436, the polymethylmacrylate is ALTULITE 2710 and the polyvinylidene fluoride is FORAFLON 1000 HD.

The viscosity of acrylomarll-buaacΓen-sayee ^toO^pO^lymeters, measured^and pn ae^ploa²²⁰ ° C is ⁷.⁵ x 1 ° ^pas ^exand ^Gra^dSpeed ​​5^,6 with^_1and 1.0 x ^{103 p}as, inc. ^Gra^dientu 2 s "¹. ^INis^toozita of polymeamethylmeahacrylate, measured at temperature ²⁰⁰ ° C is 1^1,0 x 10³ at ^Gradientu ⁵.⁶ with"¹ and ^1,4 x ^{103 p}as p^{ři g}ra^dientu ² with^-1.

^TOonečn^and vfetoztta ^pol^yvin^yliday^fluori^du, measured^and při te^plotě ²⁰⁰ ° C is ^14,1 x 10³and ^0,88 x ^{103 p}as pn ^Gra^dien^tec^h r^yC^hlosai ^3,5 respectively. ³⁵⁴ with^-1.

The temperatures at which the extruders are heated range from 190 to 210 ° C^tor^yloniirll-buaa^dien-si^yfrom 180 to 200 ° C for a mixture containing polymethylmethacrylate and from 180 to 220 ° C for polyvinylidene fluoride.

The temperature of the flow distributor and extrusion die is 210 ° C. The calender rolls are maintained at 80 ° C.

Celtově vypracovan^E · Mno^ofsiv^and min approximately 300 kg / h. Amounts to be fed from one to the other^h the soybean extrusion is regulated^and to get a horse^CA combined composite material comprising a thickness of acrylonitrile-butadiene-heptene copolymer ⁴ mm^, a blend containing 30 μ tη of polymethylene chloride and 100 µl of polyvinylidene fluoride. The three layers are perfectly aligned with each other as they exit the extrusion die. After cooling, a combined material of homogeneous structure is obtained, one surface of which is made of polyvinylidene fluoride, the other of which is an acrylonitrile-1-butadiene-styrene copolymer.

Example 6

The process was carried out under the conditions described in Example 5, but instead of a mixture containing polymethyl methyl methacrylate, a mixture consisting of 30 parts by weight of polymethyl methacrylate (RESARITE KOS 125) was used. ^hmot: nos^h days ^pol^yand^tor^ylové^ho · (thyrate (ACRYLOID KM 323B) and 30 parts by weight acre^ylonitrl-buaadien-st^yof a renal copolymer (UGIKRAL SF 10 436).

A composite material of a homogeneous composition is obtained, the layers of which are perfectly matched to each other as they exit the extrusion die, and whose one surface is made of polyvinylidene fluoride and the other consists of an acrylomarllbuaadienstyrene copolymer.