DE2445435A1 - SOFTENED POLYBLEND RUBBER AND METHOD OF MANUFACTURING THEIR PRODUCTION - Google Patents

Description

DR.-ING. FROM KRCISLCR DR.-lttG. LCHÜNWALD DR.-ING. TH. MEYER 'DR. FUES DIPL-CHEM. ALEK VON KREISLER DIPL.-CHEM. CAROLA KELLER DR.-ING. KLÖPSCH DIPL.-ING. SELTING

COLOGNE 1, DEICHMANNHAUS

Cologne, September 23, 1 97-AvK / Ax

The B.3P. Goodrich Company,

500 South Main Street, Akron, Ohio 44518 (U.S.A.).

Plasticized polyblend rubbers and processes too

their manufacture

It is known that vinyl resins are plasticized or made from transferred from the hard, horn-like and stiff state to a soft, plastic, workable state by adding certain plasticizers, e.g., dioctyl phthalate, at elevated temperatures. It is also known that vinyl resins are converted into elastic, resilient, rubber-like compositions Can be made by using conventional mixers normally used in the manufacture of rubber or Plastic mixes of the type used, e.g. roller mixers .Qdpr Banbury mixers, with a synthetic rubber copolymer of 1,3-butadiene and acrylonitrile be mixed. Mixtures of this type are referred to as "polyblend rubbers" and normally contain a plasticizer for the incorporated vinyl resin. In addition, these mixtures must be used during the Mixture preparation plasticized or heated to a predetermined temperature to produce the vinyl resin to soften enough. This is time consuming and costly.

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2U5.435

Another method of manufacturing the polyblend rubbers one mixes a latex of a rubber-like copolymer, e.g. a copolymer of 1,3-butadiene and acrylonitrile, with a vinyl resin latex and a plasticizer emulsion, as numerous applications for mixtures of Mtrilkautschuklatices and vinyl resin latices "for example for the use for lamination of fabrics, especially as a reinforcement layer when coating the underside of fabrics for floor coverings, e.g. Teppiohe. The addition of the plasticizer while mixing the latices however, poses problems. The plasticizer softens the nitrile rubber latex during the drying stage and does not soften the vinyl resin latex to a satisfactory extent during the drying step. This has to The result is that the polyblend rubber is sticky and difficult to handle. To this undesirable phenomenon To avoid this, a significant portion of the plasticizer must be brought into more intimate contact with the vinyl resin. It can thus be seen that a method which enables the plasticizer to be added to the vinyl resin portion of the polyblend rubber would be highly desirable and beneficial. :

Surprisingly, it has been found that sleeping softly Polyblend rubbers made from Mtril rubber and vinyl resins without strong mixing and shear effects at high temperatures by using a vinyl resin a ', which by polymerizing the vinyl monomer or monomers in the presence a plasticizer for the vinyl resin, which is compatible with the nitrile rubber used in the polyblend rubber has been produced, (^ can be produced ^ L This polymerization process is described below

referred to as "plastimerization". j

In the context of the invention, “vinyl resins” are polymers and copolymers of vinyl and vinylidene halo-

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genides, for example vinyl chloride and vinylidene chloride. The vinyl halides and vinylidene halides can be copolymerized with one another, or each of them can be copolymerized with one or more vinylidene monomers having at least one terminal group of the I formula CH _? = Contain CC, are copolymerized. Examples of such vinylidene monomers are: diece, ß-olefinically unsaturated carboxylic acids, e.g. acrylic acid, methacrylic acid, ethacrylic acid, α-chloroacrylic acid and α-cyanoacrylic acid, esters of acrylic acid, e.g. methyl acrylate, ethyl acrylate, butyl acrylate, octyl acrylate and cyanoethyl acrylate, esters of methacrylic acid, eg methyl methacrylate and butyl methacrylate, nitriles, eg acrylonitrile and methacrylonitrile, acrylamide ^ eg methylacrylamide, U-methylolacrylamide and N-butoxymethacrylamide, vinyl ethers, eg ethyl vinyl ether and chloroethyl vinyl ether, vinyl ketones, styrene and styrene derivatives such as

ct-methylstyrene, vinyltoluene and chlorostyrene, vinylnaphthalene. Allyl and vinyl chloroacetate, vinyl acetate, vinyl pyridine and methyl vinyl ketone, diolefins, e.g. butadiene, Isoprene and chloroprene, mixtures of the aforementioned monomers and others that can be polymerized with them Vinylidene monomers, e.g. esters of maleic acid and eumaric acid, and other vinylidene monomers of the types known to those skilled in the art. Purely for use in polyblend rubbers According to the invention, resin latices are particularly suitable, which are formed by the polymerization of vinyl chloride or vinylidene chloride alone or as a mixture with one or more vinylidene monomers copolymerizable therewith in amounts up to about 80 wt .- $, based on the i Mixture of the monomer mixture, be prepared in the presence of a suitable plasticizer for it. Particularly preferred vinyl resin for the purposes of the invention is polyvinyl chloride, so that the invention is in conjunction thus described, but the invention is not intended to be limited thereto.

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The nitrile rubbers used for the purposes of the invention are copolymers of a 1,3-butadiene hydrocarbon, which means 1,5-butadiene and its hydrocarbon homologues, for example isoprene, with an acrylonitrile, for example acrylonitrile or methacrylonitrile. Preferred Mtrilkautschuke copolymers of butadiene-1 ₃ 3 and acrylonitrile. The copolymers or nitrile rubbers can be produced by "any known method of producing copolymers, but it has been found that the best results are achieved with copolymers produced by emulsion polymerization, especially" when a nitrile rubber latex is to be used in the polyblend rubber . ' This is discussed in more detail below. The copolymer can contain other materials in small amounts, which either have been polymerized together with the 1,3-butadiene hydrocarbon and the acrylonitrile or have been added after the polymerization. It is advantageous to make the copolymer as plastic as it is consistent with the tensile strength by kneading or in any other way, for example by adding a plasticizer, before it is used in the context of the invention. The preferred copolymers contain about 50 to 80 wt .- ^ of a 1,3-butadiene and 20 to 50 wt .- ^ of an acrylonitrile, since copolymers of this composition with the polyvinyl chloride and the above-mentioned other polymers and copolymers are particularly ver / are , but copolymers with a higher butadiene content can also be used. i

In the polyblend loudspeakers according to the invention vinyl polymers or resins used can by customary polymerisation reactions, but they are preferably produced by emulsion polymer

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sation in an aqueous medium in the presence of a plasticizer for the vinyl polymer to be produced manufactured. As examples from the large number of plasticizers used in the production of vinyl polymers can be used: organic phosphoric acid esters, e.g. tricresyl phosphate, Triphenyl phosphate and isodecyl diphenyl phosphate, and Phthalic acid esters, e.g. dioctyl phthalate, dimethyl phthalate, Dibutyl phthalate, dilauryl phthalate, dimethyl tetrachlorophthalate and butyl phthalyl butyl glycolate. Virtually all of the known plasticizers for polymeric vinyl halides can be used in the polymerization reaction. It has been shown that 100 parts of plasticizer per 100 parts of monomer are the maximum that can be added as a polymerization component. If larger amounts are used, the rate of polymerization and conversion are adversely affected. I.

The aqueous medium which is used to prepare the vinyl polymers by emulsion polymerization can be emulsifier-free or contain an emulsifier. When using emulsifiers to produce the vinyl polymer latices, the general types of anionic and nonionic emulsifiers are used. Excellent results were obtained when using anionic emulsifiers. Usable anionic emulsifiers are, for example, the alkali or ammonium salts of the sulfates of Cg-C ₁ g alcohols, for example sodium lauryl sulfate, ethanolamine lauryl sulfate and ethylamine lauryl sulfate, alkali and ammonium salts of sulfonated oils from petroleum and paraffin oils, sodium salts of aromatic acids -1-sulfonic acid and octadiene-1-sulfonic acid, aralkyl sulfonates, e.g. sodium isopropylbenzenesulfonate, sodium dodecylbenzenesulfonate and sodium isobutylnaphthalene sulfonate, alkali

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and ammonium salts of sulfonated dicarboxylic acid esters ^ e.g. sodium dioctyl sulfosuccinate and disodium n-octa-

ma.
decylsulfosuccinait, and alkali or ammonium salts of the free acid of complex organic mono- and diphosphate esters. Nonionic emulsifiers, for example octyl- or nonylphenylpolyethoxyethanol, can also be used. Vinyl polymer latices with excellent stability are obtained when the alkali and ammonium salts of aromatic sulfonic acids, alkyl sulfonates and long chain sulfonates are used.

When using an emulsifier, its amount can be up to about 6 wt .- ^ or more based on the weight of the or the monomers to be polymerized. The emulsifier can be used all at once at the beginning of the polymerization or added in portions or by adding during the entire polymerization. j

The polymerizations of the vinyl monomers are carried out at temperatures of about 20 to 70 ^° C. in the presence of a compound which is able to initiate the polymerization. In general, radical-forming initiators are used. Examples of such initiators are the various peroxygen compounds, for example persulfates, benzoyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, tert-butyl diperphthalate, pelargonyl peroxide and 1-hydroxycyclohexyl hydroperoxide, and azo compounds, for example azodiisobutyronitrile and dimethylazodiizodi. Particularly advantageous initiators are the water-soluble peroxygen compounds, for example hydrogen peroxide, and the sodium, potassium and ammonium persulfates, which are used as such or in an activated redox system. Typical redox systems include the alkali persulfates in combination with a reducing substance, for example sodium sulfite or sodium bisulfite, a reducing sugar, dimethylaminopropionitrile, a

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Diazomercapto compound and a water-soluble ferricyanide compound. Heavy metal ions can also can be used to accelerate the persulfate catalyzed polymerization. Particularly well suited are alkali and ammonium persulfates. The amount of "initiator" used is generally in Range between 0.1 and 3.0 wt .- ^, preferably between about 0.15 and 1.0 wt .- ^, based on the ' Weight of the monomer (s). The initiator can be added all at once at the beginning of the polymerization. However, it is often beneficial to use during the entire polymerization is added in portions or metered in. . · J

The pH of the polymerization system is not critically important, but a pH of 7 or less is preferably maintained during the polymerization. This is achieved by using ^: buffering agents, for example trisodium phosphate or tetrasodium pyrophosphate, in the reaction mixture. The vinyl polymer latex produced in this way can then be adjusted to any desired pH value. ^!

When using plasticized vinyl resins ^ in Polyblend rubbers, the nitrile rubber and a Containing plasticizer, as is the case according to the invention, can contain a much larger amount of plasticizer the polyblend rubber can be incorporated. Plasticizer concentrations from 5 to 100 parts per 100 parts of total polymer can be achieved. These include both the plasticizer in the plasticized polymer and the plasticizer in the mixture added emulsion. In cases where no additional plasticizer is required to achieve the desired A stabilizer emulsion is used to achieve the final concentration of the plasticizer in the polyblend rubber

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the only material added to the latex mixture will. The plasticizer-stabilizer emulsion is prepared by any conventional method of emulsion preparation,

known to those skilled in the art. j

The plasticized vinyl resin latex, the nitrile rubber latex and the plasticizer emulsion are physically mixed, e.g., by stirring, after their preparation. The mixture formed here usually contains about 10 to 90 parts by weight of the nitrile rubber ' latex and about 90 to 10 parts by weight of the latex of the plastimerized Vinyl resin. Mixing can expediently take place at room temperature in any suitable vessel equipped with a suitable stirrer. The mixture is then coagulated and isolated and dried to obtain the polyblend rubber. Coagulation is carried out by the aqueous mixture is poured into an aqueous solution of a coagulant suitable for the mixture will. The most suitable coagulant is an aqueous calcium chloride solution, usually a Concentration of about 3 to 10 wt .- ^ has. Others too water-soluble coagulants, e.g. the water-soluble metal sulfates and metal chlorides, e.g. sodium chloride, Barium chloride, aluminum sulfate and magnesium sulfate can be used. The coagulated polyblend rubber is removed from the aqueous medium by filtration, washing with softened water and drying separated in conventional equipment, e.g. drying oven and fourdrinier sieves.

So far, the production of highly plasticized polyblend rubbers formed by mixing the latices has been the focus made of vinyl resin and Mtrilkautschuk the obstacle that the mixtures were too sticky to be in usual equipment to be dried. As mentioned earlier, the stickiness was due to the fact that

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most of the plasticizer was present in the nitrile rubber phase of the blend. In the iolyblend rubbers according to the invention, in which plasticized vinyl resins are used, the tack is none Problem more. This is due to the fact that the ratio of plasticizer to nitrile rubber is sufficient is lowered to avoid stickiness. Furthermore, the PolylDlend rubbers according to the invention as a result Dried by extrusion to avoid stickiness will.

The invention is further illustrated by the following examples. In these examples all relate Parts and percentages by weight unless otherwise specified.

example 1

This example illustrates the preparation of a nitrile rubber latex from 1,3-butadiene and acrylonitrile. The copolymer was produced in the form of a latex by emulsion polymerization at 5 ° C. using the following approach manufactured:

1,3-butadiene

Acrylonitrile

Emulsifier *

Dispersing agent ** Sodium formaldehyde, uIfoxylate Cumene hydroperoxide

Complex iron Softened water

74.7 parts Il Il 35.6 It 4.6 Il 0.1 Il 0.1 Il 0.12 0.008 » 195.0

* Abietic acid sodium salt

** Polymerized sodium salt of an alkylnaphthalenesulfonic acid

The polymerization reaction was carried out until 85% of the monomers had converted into the copolymer.

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The reaction was terminated using hydroxylammonium sulfate (0.42 parts) as a terminating agent. The latex formed in this way had a total solids content of 30 <fo. j

Example 2 !

This example illustrates the preparation of the latex of the plasticized vinyl chloride resin. That plastimerized polyvinyl chloride in the form of a latex by emulsion polymerization at 45 C with the made the following approach: j

Softened water 200 parts ^:

Vinyl chloride '100 ":

Dioctyl phthalate. 90 ^H :

Sodium Lauryl Sulphate 0.9 "

Isopropyl percarbonate 0.1 "j

The polymerization reaction was carried out until 75% of the monomers had been converted into polyvinyl chloride. The resulting latex had a total solids content of $ 37.5. This latex was used for subsequent Identification referred to as "Latex II".

A second latex of plasticized polyvinyl chloride was made using the above approach and under produced the same polymerization conditions with the difference that 63 parts instead of 90 parts Dioctyl phthalate was used per 100 parts of vinyl chloride. The latex produced had a total solids content of $ 42 and was named "Latex H-A" for further identification. j

Example 3 i

A mixture of latices was used to prepare a comparative sample of a polyblend rubber as follows produced5 With stirring, 2312 g of the according to Example 1 latex produced with 1864 g of a polyvinyl

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Chloride latex mixed without plasticizers after a conventional emulsion polymerization processes had been prepared so that the latex was 38 total solids contained. The polyblend rubber was then added to a plasticizer emulsion, which was homogenized of the following components had been manufactured: ■

Softened water . 1000 g

Dioctyl phthalate 960 g

Epoxidized soybean oil 24 g

Cadmium-barium soap as stabilizer 12 g

Organic phosphite (chelating agent) 4 g

Dodecylbenzenesulfonate sodium salt 96 g

The latex mixture was then to coagulate the rubber Polyblend a solution of 334 g of calcium chloride in 7.26 kg of water at 50 ⁰ C en.thärtetem added. After complete coagulation, the brine was poured off and the polyblend washed twice for 10 minutes per 1 11.36 softened water at 27-30 ⁰ C. The polyblend rubber was then formed into a plate on a conventional Fourdrinier wire and with a platen press. The crumbs of the polyblend rubber stuck very strongly to the screen, to the fabric and to the pressure rollers and had to be scraped off. The crumbs of the polyblend rubber were placed on drying trays under; dried under reduced pressure. .

i Example 4

Two latex mixtures were made as follows:

A) 2512 g of the latex produced according to Example 1 were mixed with 2240 g of the latex H-A at pH 10 with stirring.

B) 2312 g of the latex prepared according to Example 1 were also added at pH 10 with stirring with 2240 g

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Latex II mixed.

The polyblend rubbers (A) and (B) were then added to separate calibration emulsions both were made by homogenizing the following ingredients:

Softened water . 496 g

Dioctyl phthalate 456 g

Epoxidized soybean oil ■ 24 g cadmium barium soap 12 g

Dodecylbenzenesulfonate sodium salt 4.8 g

Each of the latex mixtures prepared in this manner was then added to coagulate the polyblend separated rubbers solutions per 364.16 g of calcium chloride in 7.26 kg softened water contained and had a temperature of 50 ⁰ C. After complete coagulation, the polyblend rubbers were separated off in the manner described in Example 3, washed and dried. In contrast to the comparison sample prepared according to Example 3, both polyblend rubbers could be processed well on the plate press and did not pose any problems with regard to stickiness.

Example 5 ^]

The polyblend rubbers produced according to the above examples, namely the comparative sample, the Latex II and latex H-A were processed into rubber mixtures with the usual mixture components, molded into panels and tested to illustrate the superior results obtained through use of a plasticized vinyl resin latex in a polyblend rubber be achieved. All polyblend blends were made on the roller mixer according to the following recipe processed into rubber compounds: I.

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Polyblend rubber, zinc oxide, stearic acid, carbon black

Tetramethylthiuram disulfide (Vulcanizing agent)

100 parts 5.0 «1.0 40.0

3.5

Il It

After mixing, each mixture was made into sheets on conventional machines. ^{The plates from each mixture were vulcanized at 170 °} C. for 5 minutes, 10 minutes and 20 minutes. After vulcanization, the samples were tested and the following results were obtained:

Vulkani- comparative mixture mixture sation mixture II HA time, III
Minutes

Tensile strenght,
kg / cm ^ 5 106.4 118 143 10 111 121 151 20th 105.9 129 166 Elongation at break, $ 5 236 490 453 10 226 395 423 20th 200 375 403 Hardness, duro-
meter A 5 67 59 63 10 67 58 62 20th 67 58 62

The above results show that the polyblend rubbers according to the invention have much higher tensile strengths and elongations have polyblend rubbers known as dip and, more importantly, are softer than known polyblend rubbers of the same composition.

The polyblend rubbers according to the invention are preferably made by mixing latices of the nitrile rubber

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schuks and plasticized vinyl resin, however, it is also possible to coat the desired plasticized vinyl resin with the nitrile rubber a roller mixer to mix. This is especially true in cases where there is no additional plasticizer "with is added to the production of the polyblend rubber.

The. Polyblend rubbers have a wide variety of uses for example in the packaging sector, for the sheathing of cables, etc. They are special advantageous when flexibility is required, as is the case with foils and coatings, for example when laminating of fabrics, fleece and similar substrates is the case. Furthermore, if non-flammable or flame-retardant If end products are desired, a suitable plasticizer can simply be chosen with this Properties are obtained. Even more important is the fact that the polyblend rubbers according to the invention can very easily be converted into a finely divided powder by conventional methods that cannot can only be easily handled and shipped, but also has economic advantages in processing for the end user or processor. Numerous others Applications and advantages will be apparent to those skilled in the art.

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Claims (1)

-15 claims 1.Softened polyblend rubbers based on nitrile rubber and plasticized vinyl resins, characterized in that they contain vinyl resins which by Polymerization of the vinyl monomer or monomers in the presence of a plasticizer compatible with the nitrile rubber for which vinyl resin have been manufactured. j 2. Polyblend rubbers according to claim 1, characterized in that they are polyvinyl chloride as vinyl resin contain. 5. polyblend rubbers according to claim 1 and 2, characterized characterized in that it is a copolymer as nitrile rubber of 1,3-butadiene and acrylonitrile. 4. Polyblend rubbers according to claim 1 to 3. » through this characterized in that they contain dioctyl phthalate as a plasticizer. 5. Polyblend rubbers according to Claims 1 to 4, characterized characterized in that, in addition to the plasticizer contained in the vinyl resin, it contains a further plasticizer component, which is preferably dioctyl phthalate. . Process for the production of polyblend rubbers according to Claims 1 to 5, characterized in that one a) a vinyl and / or vinylidene halide, if necessary. with 'one or more vinylidene monomers which have at least one terminal group of the formula CH ₂ = C ζ ^! contained, polymerized in an aqueous medium which contains a polymerization initiator and a plasticizer for the polymer formed, i b) then the polymer-containing aqueous medium of (a) Mixes with a nitrile rubber latex that contains a Copolymer of a butadiene-1,3-hydrocarbon 609814/1023 and an acrylonitrile, and! I, I c) the mixture obtained in (b) with a water-soluble coagulant to coagulate the plasticized one Polyblend rubber mixes. 7. Method according to claim 6, characterized in that _; a nitrile rubber latex is used which contains a copolymer of butadiene-1, j5 and acrylonitrile. 8. The method according to claim 6 and 7 > characterized in that calcium chloride is used as the coagulant. 9. The method according to claim 6 to 8, characterized in that that an aqueous emulsion of the plasticizer used in step (a) '■ mixed with the requested in step (b) conservation · mixture. ' 6098U / 1023