DD276600A3 - Elastomer-modified thermoplastic molding compound - Google Patents

Abstract

The invention is based on an elastomer-modified thermoplastic molding composition which consists of a mixture of thermoplastic and elastomeric Sekundaerrohstoffe. It is preferred for use in the injection molding of products with high demands on the Kaelteschlagaenzigkeit. The essence of the formulation consists in a predominant proportion of a heterogeneous polyolefin mixture, a proportion of crosslinked rubber mixture and a small proportion of dispersing aid. In this case, the so-called floating fraction (LDPE, HDPE, PP) from the density separation of comminuted household waste is used as the polyolefin mixture. In particular, paraffin oil is proposed as dispersing aid, while the elastomeric component is formed from synthetic rubber regenerate of ready-made form and has a proportion of less than 13% of the total mass.

Description

field of use

The invention relates to a molding material Zusammrotzensungung to Spritzglasson of products that have to meet special requirements for the mechanical Konnwertniveau. This is preferably true for the impact resistance, as it is e.g. is demanded in plastic moldings of the container range in the construction industry. The processing plants which have to prepare the molding compositions themselves using secondary raw materials by themselves are the main users of the invention.

Known solutions

As basic components for improving the toughness of polyolefin standard molding compounds, the basic material suppliers offer so-called thermoplastic elastomers. For solving the problem of compatibility between the thermoplastic and the elastic phase, it seems that such a great effort has to be made in their production that Aufkommon and Preis do not justify the use for the mixing of molding compounds for relatively short-lived mass products with specific rigidity requirements. Moreover, in the production of the thermoplastic elastomers or of polyolefin elastomer shells, due to the specific production conditions in the dispersion phase, severe thermal and mechanical stresses occur, which have a negative effect on the form-casting quality. This has its origins in the very different rheclogischon behavior of thermoplastic and elastic components. With the aim of providing a wear-resistant and readily processable polyethylene material, therefore, according to a proposed proposal, the polyethylene 10 to 50% of the total volume of comminuted rubber as an additive zuiusotzen (DD 137938). Both components should also be able to be used from secondary sources. The field of application is boiled down to products which have been subjected to a positive temperature range. Insofar as the thermoplastic portion of defined polyethylene of the internal Regonerotkreislaufes at the processor or sorting gen foreign Polyethylonabfällen, this solution appears to other users jsfällo transferable with comparable product requirements. For dia in Scliwimm-Sink-Verfahron selected Sekundnrpolyolefine from household waste (floating fraction) but so are both in terms of VerarboitbarkeU as well as in terms of Formteiloigenschafton in terms of high dynamic mechanical stresses in the low temperature range to achieve any positive results. This also applies to another bokonnto solution, according to which oorine rainorate mixture contains 50% to 80% gum glial material. The textiles Fasorantoilo from the Roifon and the Füllstoffontoilo from Dom plastic scrap are explicitly in Rozoptur einbozogon (DE 2729784). A ziiEÖuiichor Naciiiuii üiusus Vuiäciiiäüus büäiüni ίη the increased Aufboroitungsaufwand for dio formation dos compounds.

invention target

Dio expenses for dio Boroitstoilung uinor olostomermodifiziorton, cold forging Thormoplastformmasso for Spritzgioßfortigung mechanically heavily stressed moldings are compared to the prior art to reduce. This includes dio oinfocho prefixing of the olastomoron component), the cost of procuring the raw material, and the technological expense of preparing the mixture.

Walls of the invention

The problem resides in finding a formulation which makes it possible to use the cooling fraction, which is economically obtained from the selection of household pimples, for high-impact gasoline / castings. It should be 3oll by means of oinns Doppelschncckenextiuders sufficient HomogonUat the molding material to be achieved. According to the invention, the molding composition consists of 60 to 87% of a heterogeneous polyolefin mixture, to 5 to 31% of a rubber regenerate mixture and to max. 8% from a DiS energy additive in mass proportions. In this case, the polyolefin mixture is obtained from the floating fraction böi density separation of shredded household waste and has 60 ... 85% low density polyethylene, max 40% high density polyethylene and minimal 5% polypropylene. The rubber granulate is composed of cross-linked gum waste with predominantly synthetic rubber fractions mined to a particle size of <10 mm and compounded in an ochnologischon precursor to a highly concentrated elasiomerbatch on the polymeric matrix secondary raw material. The dispersing aid is paraffin oil, which has been added optionally or in admixture with a functional oligomer.

AusführungsbetapieU-

About a volume metering by Extrus'on in a single DoppelschneckenexUuderdurchlauf the Elsstomerkomponcn'n in the form of ready-made Elastomerbaich, as well as the DispergierhilfsmiUel have been mixed by means of liquid metering in a Thermoplas'.aufbereitungsar.lage floating fraction. The resulting granular material from preschordiod formulation variants has been processed by injection molding into test plates. In this case, a good homogeneity and reproducible Varührungsseigenschaiiün could be detected. Bo; In the dynamic mechanical test, a significant improvement in the entropic field behavior of materials in the low temperature range up to above the glass transition temperature was found. The molding compounds prove to be suitable for the production of products of the construction assortment with high mechanical requirements, in particular for falling strength at low temperatures 3 ¹ S. This is because of the thermodynamic intolerance of the reason; :> niponenten around a principally heterogeneous polymer mixture. The incompatibility of the components results, inter alia, from the existing ratio of the surface tensions and the difference in viscosity of the base component. The use of the described dispersing aid as an additive to e'astomermodifizisisfin thermoplastic compound effect; an approximation of the physico-rheological characteristics of the basic polymorphic Kononon accounts, resulting in a much improved Oispergierung the Elast and the plastic phase. Furthermore, an influence of the molecular interactions between the heterogeneous Grundpo-ymeren of the compound and, as a result, a higher solubility of the two Grundpolymcrer

 The following proportions are for%.

example 1

For the compounding of a heiorogenon polyolefin formulation, 64.8% of the float fraction was processed, consisting of about 75% LDPE, 20% HDPE and 5% PP by continuous volume reduction with 27.8% elastomer effluents in the form of highly retorted elastomorbatch predominantly butyl rubber. Regenerative, consisting of, mixed in. To the molten Plastiziorzylinder in a twin screw extruder the polymer matrix phase using melt were Müssigkeitsdosiervorrichtung ^r cino practice corresponding vent opening of the cylinder 7.4% of paraffin oil are added at the time of Vordisperqierung in a first Dekomprossionsphase DIM. The processing conditions at ccmpounding were defined as follows:

· -Schneckendrehzahl. 120min '

- melt pressure: 110Pa

- Melting temperature: 205X

- Extrudorzylindertemperatur: 160X - Mold temperature: 200 ¹ C

The material thus gowonneno was granulated and processed over a conventional Spritzgielimaschine to Plattenprüfkörporn. In the dynamic test ancestors in the torsional vibration test and in the tensile test, the following mechanical characteristics were determined.

Tensile strenght: 10,4MPa Elongation at break: 32% Shoe module boi 20'C: 191MPa LoiO C: 268MPa boi 10 C: 325MPa boi 20 C: 405MPa log.Dokromoniboi 20'C: 0.172 Kältorichtwort: 41 C Tomporotur boi 10'N / mm ': 50'C Tomporoturboi2 χ lO'N / mm ² : 4 16 C

Example 2

Boi oinor aggregation of the Sokundärplastgomischos wio in Boispiol 1 wurdon 67.3% diosor component with 28.9 ° ready made Butylrubber-Rogonoratgomisch vorsotzl and in Doppolschnockonoxtiudor with 3.8% paraffin oil homogonisiort.

processing conditions 12ümin ~ ' - screw speed: 125Pa - Melt pressure: 210X - Schmalzentempeiatur: 160X - Extrudeic cylinder temperature: 200X - Tool temperature: Ksnri values of the specimens 7,3MPa - Tensile strenght: 16% - Elongation at break: 223MPa - Sr.hubmodulbei? OX: 306MPa at OX: 361 MPa at-10X: 439MPa at-20X: 0,610 - log. Decrement at -20T .: -10X - cold light value: -DOX Temparaturbei 10 ³ N'mm ² : t26 ^c C - Temperature at 2 χ 10'N / mnV:

Example 3

In analogous technological Com ipoundiorschritten as in the aforementioned Examples 1 and 2, the following mixture was prepared:

80.0% secondary plastic mixture 18.0% Sty renbutadienkauischuk-Reconeratgomisch 2.0% Paraffinöi

The plastic component consisted of 6% LDPE, 28% HDPE and 6% PP.

processing conditions 110min - screw speed: 120Pa - Schmeuendfuck: 210X - Melting temperature: 160X - extruder barrel temperature: 185 X - work temperature: Characteristics of the test specimens 10,6MPa - Tensile strenght: 12.0% - Elongation at break: 244MPa - shear modulus at 20X: 331MPa at OX: 491MPa at-10X: 646MPa at-20X: 0,310 - log. Decrement at - '' 0X: -16x - cold light value: -39 X Temperature at 10 ³ N / mm ² : + 30X Temperature at 2 × 10 ² N / mm ² :

Example 4

The molding composition differed from Example 3 by reducing the dispersing aid to 1.0% in favor of the olastomeric component.

processing conditions 110min - Schnockond speed: 110Pa - Schmolzdruck: 205X - melt temperature: 160X - Extrudor Cylinder Comporature: 185X - Work table authoring: Characteristics of the test specimens 11,7MPa - Traceability: 156% - breakage dole: 208MPa - shear modulus at 20 C: 339MPa boiOX: 459MPa at-10X: 629MPa at -20 "C: 0.306 - Log.Dokromontboi 20X: -13 C - Caitorial word: 38 C - Tomporuturboi 1O ³ N / mm ² : »20 C - temperature boi 2 χ 1O ² N / mm ² :

Claims (4)

1. Elastorhermodifizierte thermoplastic molding composition consisting of a mixture of thermoplastic and elastomeric secondary raw materials, characterized by a composition of the mass fractions of 60 ... 87% heterogeneous polyolefin mixture
5 ... 32% Kautschukregeneratgernisch
Max. 8% dispersing agent. 2. Elastomer-modified thermoplastic molding composition according to claim 1, characterized in that as a heterogeneous polyolefin mixture, the floating fraction from the density separation of shredded household waste with mass fractions of 60 ... 65% LDPE
Max. 40% HDPE
minute 5% PP
is used. 3. Elastomer-modified thermoplastic molding composition according to any one of claims 1 or 2, characterized in that cross-linked as rubber reclaim mixture, pre-shredded rubber waste with a predominant proportion of Synthesekautscl uk ur> d a particle size <10mm are used, which is an elastomeric on the polymer matrix matrix are made up of secondary raw material. 4. Elastomer-modified thermoplastic molding composition according to any one of claims 1 to 3, characterized in that was used as a dispersing agent paraffin oil and / or a functionalized oligomer.