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
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
  • C08J9/06—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a chemical blowing agent
  • C08J9/10—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a chemical blowing agent developing nitrogen, the blowing agent being a compound containing a nitrogen-to-nitrogen bond
  • C08J9/102—Azo-compounds
  • C08J9/103—Azodicarbonamide
• • 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
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/0061—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof characterized by the use of several polymeric components
• • 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
  • C08J2323/10—Homopolymers or copolymers of propene
  • C08J2323/12—Polypropene
• • 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
  • C08J2423/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers

Definitions

• the invention relates to a plastic foam material based on polyolefins, the 50 to 90 wt .-% polypropylene-based plastics with a melt flow index MFI (230 ° C / 2.16 kg) of 0.5 to 12 g / 10 min and 10 contain up to 50% by weight of polyethylene-based plastics with a melt flow index MFI (190 ° C / 2.16 kg) of less than 50 g / 10 min and the plastic foam material has a density of 0.03 to 0.2 g / cm 3 , and its use in motor vehicles, airplanes and the like, in particular for the production of interior trim or trim parts.
• Plastic foam materials of the type described above result from EP 0 704 476 B1.
• This describes a plastic foam material consisting of a composition based on polyolefin, which consists of: between 40 and 95% by weight of plastics based on polypropylene a melt flow index (MFI) of 0.05 to 12 g / 10 min, between 5 and 60% by weight of polyethylene-based plastics with a melt index (MFI) of 2 to 50 g / 10 min.
• MFI melt flow index
• the plastic foam material contains between 20 and 65% by weight crosslinked portion and has a density of 0.02 to 0.2 g / cm 3 .
• the crosslinked portion should consist of 55 to 95% by weight of crosslinked polypropylene and 5 to 45% by weight of crosslinked polyethylene.
• such a plastic material is produced as follows: About 40 to 95% by weight of a polypropylene-based plastic and about 5 to 60% by weight of a polyethylene-based plastic with a crosslinking agent and a foaming agent are used to produce the plastic composition mixed. A film is produced from this, for example by extrusion. This is exposed to an ionizing radiation source in order to obtain a cross-linked film. The dosage of the ionizing radiation source should be 1.0 to 6.0 Mrad. The ionizing treatment is continued until the cross-linked portion in the art fabric composition is 20 to 65 wt .-%. This is followed by heating the crosslinked plastic film in order to obtain a plastic foam material in a density of 0.02 to 0.2 g / cm 3 . This can be done in a conventional foaming furnace at a temperature of around 250 ° C, which means that the middle of the foam is included! is thermally decomposed to create the plastic foam material.
• the known technical teaching is based in particular on the fact that a plastic foam material with superior deformation properties is to be produced which can be applied well to the surface of substrates, has superior heat resistance, improved elongation at high temperatures and superior secondary treatment properties.
• the specified framework conditions must be strictly observed for this. This applies in particular to the MFI value of the polyethylene-based plastic. For example, disadvantageous effects with regard to the deformation process should occur if the MFI value of the polyethylene-based plastic falls below 2 g / 10 min. It should then not be possible to produce the desirable products from the plastic foam material.
• the extrusion of the plastic foam material should be largely impossible if the MFI value of the polyethylene-based plastic is below the specified critical value of 2 g / 10 min.
• An MFI value of about 2 g / 10 min should in particular impair the comprehensive appearance of the plastic foam material.
• the compatibility between the polyethylene and the polypropylene or a material based thereon is to be impaired. From EP 0 704 476 B1 there are consequently strict indications that the MFI value of the polyolefin or copolymer of polyolefin used for the production of the known plastic foam material should not be reduced to less than 2 g / 10 min, since then the desired product is not arises.
• the invention accordingly relates to a plastic foam material based on polyolefins, the 50 to 90 wt .-% polypropylene-based plastics with a melt flow index MFI (230 ° C / 2.16 kg) of 0.5 to 12 g / 10 min and 10 to 50% by weight of polyethylene-based plastics with a melt flow index MFI (190 ° C / 2.16 kg) of less than 50 g / 10 min and the plastic foam material has a density of 0.03 to 0 , 2 g / cm 3 , characterized in that the plastic foam material contains 20 to 70 wt .-% crosslinked polyolefin and the polyethylene-based plastic has a melt flow index MFI (190 ° C / 2.16 kg) of less than 2 g / 10 min and more than 0.05 g / 10 min.
• MFI melt flow index
• the invention can be embodied in a variety of advantageous ways: the advantages mentioned below are achieved in particular if the crosslinked polyolefin content is based on 55 to 95% by weight based on polypropylene and 5 to 45% by weight based on polyethylene.
• a particularly preferred framework is between about 60 and "80 wt .-% of polypropylene and 40 to 20 wt .-% polyethylene. To that end the overall framework is substantially 20 to 70% by weight of cross-linked polyolefin portion.
• the plastic foam material about 30 to 60 wt .-% crosslinked polyolefin content.
• the crosslinked proportion of the polyolefin of the plastic foam material according to the invention there are various methods for determining the crosslinked proportion of the polyolefin of the plastic foam material according to the invention.
• One possibility is to determine the corresponding gel content, the crosslinked polymer portion being trimmed with the aid of xylene extraction. This takes place at a temperature of 145 ° C. After drying, the crosslinked insoluble fraction can be related to the amount of foam weighed in.
• the percentage distribution of the cross-linked share of polyethylene-based plastic and polypropylene len-based plastic can be carried out as follows: The rest of the matter mentioned is recorded by gas chromatography after the extraction, using a hydrogenation and a thermal decomposition technique. The residue mentioned and obtained by xylene extraction is thermally decomposed at 700 ° C.
• Hydrogen gas is then introduced to hydrogenate the thermally decomposed gas.
• the hydrogenated gas is a G-6800 gas chromatograph (hydrogenation type gas chromatograph manufactured by Yanagimoto Seisaushoaka).
• the above-mentioned percentage distribution of the crosslinked starting materials can be determined using C 13 nuclear magnetic resonance spectroscopy.
• the amount of tertiary carbon atoms found in polypropylene can thus be determined quantitatively in the insoluble and dried gel portion of the plastic foam material.
• calibration curves created from the starting resins used for statistical copolymer of propylene with ethylene and linear polyethylene copolymer with ⁇ -olefins are also used.
• the polypropylene-based plastic is in the form of polypropylene and / or a copolymer of propylene with another unsaturated comonomer, in particular ethylene.
• ethylene unsaturated comonomer
• the preferred unsaturated comonomers include butene, hexene and octene.
• additives can be incorporated into the plastic foam material according to the invention. These include hydrocarbon resins with a melting range of 110 to 160 ° C, preferably 125 to 150 ° C. Calcium salts of stearic acid, palmitic acid and oleic acid as well as mixtures of the salts with the acids and acid esters as well as antioxidants.
• additives can already be the different starting materials in the form of the polypropylene-based plastic and / or the polyethylene-based plastic are incorporated, but are usually added during the manufacture of the polymer compounds.
• portions of the polyethylene-based plastic and portions of the polypropylene-based plastic can be present separately in the plastic foam material according to the invention. It has been shown that the part based on polypropylene forms the continuous phase, while the part based on polyethylene is the phase dispersed therein.
• melt flow index MFI (230 ° C / 2.16 kg) of the polypropylene-based plastic is between about 0.4 and 0.9 g / 10 min and / or the melt index MFI (190 ° C / 2, 16 kg) of the polyethylene-based plastic is between about 0.5 to 1.9 g / 10 min. It is particularly advantageous if the melt flow index MFI (190 ° C./2.16 ' kg) of the polyethylene-based plastic is between about 0.7 and 1.5 g / 10 min, in particular between about 0.8 and is 1.2 g / 10 min.
• the production of the plastic foam material is essentially as described above in connection with the explanation of the disclosure of EP 0 704 476 B1.
• An essential additional idea is discussed below.
• a film or another molded part is first produced from the starting materials, for example by extrusion. This is followed by networking with an ionizing radiation source, in particular in the form of an electron beam source.
• the type of crosslinking agent that is incorporated into the starting materials is decisive for the product quality. In any case, it is preferred to use one.
• crosslinking agents in the form of divinylbenzene, ethylvinylbenzene, trimethylolpropane triacrylate, trimethylolpropane trimeihacrylate, 1,6-hexanediol diacrylate, 1,2,4-triallyl-trimel-litate and / or triallyl isocyanurate are particularly advantageous.
• a thermally decomposable foaming agent is included in the production of the desired plastic foam material.
• This is preferably an azodicarbonamide, an azodicarbonamide in the form of 1,1-azobisformamide, benzenesulfonyl hydrazide and / or toluenesulfonyl hydrazide being particularly suitable.
• additional additives can be, for example, fillers or pigments, in particular in the form of potassium aluminum silicate, talc, chalk, kaolin, metal oxides, in particular titanium dioxide, and / or carbon black.
• lubricants which should be incorporated into the starting material of the plastic foam material according to the invention. This can be an internal or external lubricant.
• Both types of lubricant can also be used together.
• Hydrocarbon waxes with a melting range of 110 to 160 ° C., preferably between 125 and 150 ° C., and stearic acid esters, palmitic acid esters and the Ca salts of these organic acids have proven to be particularly advantageous internal lubricants.
• a particularly suitable external lubricant is a solid combination lubricant containing metal soap with high molecular weight fractions (complex esters) (melting point: 105 to 115 ° C).
• the invention is not subject to any significant restriction with regard to the amount of lubricants used. It is preferred that the inner lubricant and the outer lubricant are contained in the finished plastic foam material in an amount of 1 to 5% by weight, in particular in an amount of about 0.3 to 2.0% by weight ,
• high-melting hydrocarbon resins with a melting range of 115 to 150 ° C can also be used.
• the melting and mixing zones in the extruder are designed in such a way that sufficient and safe melting of the added granules is achieved and the mixing and melting energy is limited in such a way that reliable temperature control of the compound mixture below 185 ° C is ensured.
• the specific energy input via the drive motor of the twin screw should not exceed 0.145 kWh / kg.
• the plastic foam material according to the invention can advantageously be processed in a conventional manner to give decorative laminates with grained decorative film. These laminates are generally processed into the decorative surfaces of components using the deep-drawing process. However, they can also be suppressed in suitable tools for component production or back-injected with thermoplastic materials.
• the plastic foam material according to the invention is particularly suitable for producing foam laminates which are used in aircraft and motor vehicles as surface materials for interior linings, in particular control panels or dashboards, columns, motor vehicle side linings, Door panels, trays are used. They are processed either using the deep-drawing, back-pressing or back-injection process. It has been shown here that the plastic foam material according to the invention compared to comparable products that are manufactured according to the prior art and in which a polyethylene-based plastic with an MFI value (190 ° C./2.16 kg) of more than 2 g / min is used, has better elongation values at low temperatures and at room temperature, as the following comparative experiments show.
• MFI value 190 ° C./2.16 kg
• the particular advantage of the invention lies in the fact that it provides the processor with an additional flexibility, also the advantageous polyethylene-based plastics of an MFI value (190 ° C./2.16 kg) of excluded from the prior art use less than 2 g / min.
• a 2-shaft extruder (temperature control 160 to 185 ° C / speed 140 rpm) is used.
• the plastic composition was extruded in the form of a 1 mm thick film. This is cross-linked by the action of electron beams from a ß-emitter (1.8 MIV system).
• the beam current used is four times in the various examples: example 1 2.00 [mA / m / min] four times, example 2 1.75 [mA / m / min] four times, example 3 1.5 [mA / m / min ] four times, example 4 1.75 [mA / m / min] four times, example 5 2.5 [mA / m / min] four times. All current specifications apply to a scan length of 1 m. This is followed by foaming of the cross-linked compact film material in a hot air oven at 270 ° C.
• Table I The formulations according to the invention of Examples 1 to 5 (numbers in parts by weight) are shown in Table I below.
• Plastic foam materials can be produced which are of practical value with regard to the essential characteristics.
• the comparison films were produced by extrusion in accordance with Examples 1 to 5 and crosslinking on a 1.8 MeV system, with 2.0 [mA / m / min] fourfold for Comparative Example 1 and 2.1 [mA / m for Comparative Example 2 / min] applies four times.
• the foaming was also carried out in accordance with Examples 1 to 5.
• Table IV the foam properties are those of . Comparative Examples 1 and 2 obtained plastic foam materials:

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
• Compositions Of Macromolecular Compounds (AREA)

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• 2004
  • 2004-05-21 DE DE102004025157A patent/DE102004025157A1/de not_active Withdrawn
• 2005
  • 2005-05-12 WO PCT/EP2005/052166 patent/WO2005113655A1/de not_active Ceased
  • 2005-05-12 PL PL05742855T patent/PL1761591T3/pl unknown
  • 2005-05-12 PT PT57428559T patent/PT1761591T/pt unknown
  • 2005-05-12 ES ES05742855.9T patent/ES2595514T3/es not_active Expired - Lifetime
  • 2005-05-12 JP JP2007517239A patent/JP5068165B2/ja not_active Expired - Lifetime
  • 2005-05-12 EP EP05742855.9A patent/EP1761591B1/de not_active Expired - Lifetime

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