Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/24—Crosslinking, e.g. vulcanising, of macromolecules
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/04—Oxygen-containing compounds
  • C08K5/14—Peroxides
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2323/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
  • C08J2323/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
  • C08J2323/04—Homopolymers or copolymers of ethene
  • C08J2323/08—Copolymers of ethene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2331/00—Characterised by the use of copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an acyloxy radical of a saturated carboxylic acid, or carbonic acid, or of a haloformic acid
  • C08J2331/02—Characterised by the use of omopolymers or copolymers of esters of monocarboxylic acids
  • C08J2331/04—Homopolymers or copolymers of vinyl acetate

Definitions

• the invention relates to a process for the production of plastic articles from ethylene vinyl acetate or for the production of an intermediate product for further processing into such articles.
• PVC polyvinyl chloride
• thermoplastic PVC is its relatively low cost and its ease of processing.
• a disadvantage of PVC, however, is that it releases hydrogen chloride under the influence of heat, for example in the event of fire, which is an aggressive one
• PVC decomposes from around 180 degrees and releases hydrogen chloride. In addition, it • leads to intense smoke when exposed to heat, which causes an undesirable obstruction of sight in the event of fire.
• the object of the invention is to develop a process for obtaining an intermediate product for the production of articles from ethylene vinyl acetate and a process for producing the articles themselves, which are simpler and cheaper than the known processes.
• a method for producing a plastic object from the aforementioned method is characterized according to the invention by the features of the characterizing part of claim 8.
• the ethylene vinyl acetate is crosslinked before it is converted into the shape of the desired object and only then processed further into the shape of the desired object.
• the crosslinked material is expediently granulated into objects or comminuted in some other way before it is processed further.
• the granulate delivers an intermediate product for further processing. a finished plastic object. It can be converted into the shape of the desired object during subsequent processing with relatively little heating, which can be done, for example, in molds, injection molding systems or extrusion systems.
• the degree of crosslinking of the ethylene vinyl acetate contained in the starting product is about 70 to 95, preferably about 80 to 90, percent.
• the degree of crosslinking brought about in the preliminary process for obtaining the intermediate product is selected with regard to the material requirements for the finished article, such as, for example, tensile strength, tear strength, abrasion, elongation or electrical conductivity.
• the degree of crosslinking is controlled so that, on the one hand, there is sufficient crosslinking required for the desired properties of the end product, but on the other hand the intermediate product still has sufficient thermoplastic properties to enable easy further processing.
• the crosslinked material still has a sufficient viscosity (Mooney viscosity) for the subsequent deformation to the finished article.
• the starting material for the process according to the invention contains as a main component ethylene vinyl acetate in elastomeric form with an acetate content of about 40 and 60 percent by weight, preferably 46 to 54 percent by weight.
• the ethylene vinyl acetate is crosslinked with peroxides, finally accelerator, added and in a relatively small amount a number of other usual additions, such as anti-aging agents, hydrolysis protection agents, lubricants, activating agents, non-stick agents, coloring agents and / or flue gas suppressants.
• fillers in particular flame-retardant fillers, can be added in the usual way.
• ethylene vinyl acetate is the only plastic component to be crosslinked. " All other components are tools.
• the ethylene vinyl acetate is first mixed with the added components, for example by kneading or rolling, it being important to ensure that the temperature remains below the crosslinking temperature in this mixing or kneading process.
• the mixed material is then placed in an autoclave (vulcanization oven) for crosslinking and in a saturated steam atmosphere under a pressure of 3.5 to 7, advantageously 3.5 to 6, preferably 3.9 to
• the crosslinked material is then expediently granulated.
• Mixing and crosslinking can also take place in succession in one and the same vessel, for example a pressure-tightly closable internal kneader.
• a further crosslinking takes place during the later processing of the preferably granular crosslinked preliminary product not instead.
• the temperature can therefore be chosen to be relatively low. During extrusion, it is about 90 degrees in the so-called plasticizing zone and about 100 to 120 degrees Celsius in the ejection zone of the extrusion device.
• Example 2 differs from Example 1 in that the following starting materials are used:
• RC-1 (formerly called UNION CARBIDE OSC Y-9774) substance known from UNION CARBIDE as filler activator 170 parts of aluminum oxyhydrate (Apyral B 120)
• the tensile strength of the end product in this exemplary embodiment is approximately twice as great as in exemplary embodiment 1.
• Example 3 differs from Example 1 in that the following starting materials are used:
• the tensile strength values that can be achieved are even higher than in embodiment 2.
• Substances as in Examples 1, 2 and 3 are initially mixed in an open kneader, again taking care that the heating of the material produced by the kneading does not exceed 130 degrees.
• the material is then rolled into strips with a height of approximately 15 mm and, after cooling to room temperature, placed in an autoclave.
• the material is used in the same way. treated in Example 1, but a movement of the material is not carried out.
• the material is then removed from the vessel and, after cooling to room temperature, granulated.

Landscapes

• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Processes Of Treating Macromolecular Substances (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=6342501

Family Applications (1)

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Cited By (3)

Families Citing this family (1)

Citations (4)

• 1987
  • 1987-12-12 DE DE19873742232 patent/DE3742232A1/de active Granted
• 1988
  • 1988-12-10 WO PCT/DE1988/000756 patent/WO1989005328A1/de unknown

Patent Citations (4)

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