Title of Invention	A POLYOLEFIN MOLDING COMPOSITION
Abstract	The present invention relates to a polyolefin molding composition with a reduced tendency to peel, comprising an olefin polymer and 0.001 to 5 phr of an oxidized wax. PRICE: THIRTY RUPEES

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Polyolefin molding composition with a reduced tendency to peel The invention relates to a polyolefin molding composition which "peels" relatively little or not at all during extrusion. After preparation in the form of granules or grit, olefin polymers are processed to a finished component (product) by the extrusion or injection molding process. This finished component can be a film, a tube or a large or small hollow body. The problem of "peeling" occurs specifically during the processing of higher molecular weight polyolefins to give large hollow bodies (drums, tanks and the like). "Peeling" is understood as meaning the phenomenon of filsunents of the same material forming on the inside or outside of the plastic tube and later large hollow body on delivery of the polymer melt. These fileunents inter¬fere with the use of the vessel as intended, since, for exeunple, they can become detached from an inner surface of the drum and contaminate the product contained there¬in. To eliminate peeling, it is customary to change the molecular weight distribution of the polymer or to adapt the processing machines to suit a given product, for example by changing the nozzle geometry. A change in the molecular weight distribution is in general undesirable, since it leads to a change in the product properties. Modification of the processing machines is likewise usually not possible, since products from different manufacturers are used and the machines cannot be optimized for a certain product. The object of the present Invention was to prevent the occurrence of the "peeling effect" during processing of polyolefins without a change having to be made to the molecular weight distribution of the polymer or to the processing machines. This object was achieved by addition of an oxidized wax during granulation of the polyolefln powder. The Invention thus relates to a polyolefln molding composition with a reduced tendency to peel, comprising an olefin polymer and 0.001 to 5 phr of an oxidized wax. The invention furthermore relates to a process for reducing peeling during extrusion of polyolefln molding compositions. The polyolefln molding composition according to the invention comprises an olefin polymer, for example one of the following: 1. Polymers of mono- and dioleflns, for example polyethylene of high, medium or low density (which can optionally be crosslinked), polypropylene, polylso- butylene, polybut-1-ene, polymethylpent-1-ene, polyisoprene or polybutadlene, and polymers of cyclo- oleflns, such as, for example, of cyclopentene or nor- bomene. 2. Mixtures of the polymers mentioned under 1), for exeunple mixtures of polypropylene with polyethylene or with polylsobutylene. 3. Copolymers of mono- and dioleflns with one another or with other vinyl monomers, such as, for example, ethylene/propylene copolymers, propylene/but-1-ene copolymers, propylene/lsobutylene copolymers, ethylene/but-1-ene copolymers, propylene/butadlene copolymers, Isobutylene/lsoprene copolymers. ethylene/alkyl acrylate copolymers, ethylene/alkyl methacrylate copolymers, ethylene/vlnyl acetate copolymers or ethylene/acryllc acid copolymers and salts thereof (ionomers), as well as terpolymers of ethylene with propylene and a diene, such as hexadiene, dicyclopentadiene or ethylidenenorbomene. Polyethylene, polypropylene, polybut-1-ene, polyhex-1-ene, poly-4-methylenepent-l-ene, polyoct-1-ene or copolymers thereof are preferred. In addition to the olefin polymer, the molding composi¬tion comprises waxes. These waxes are oxidized fully synthetic or semi-synthetic waxes or polyolefin waxes. Preferred waxes are oxidized semi-synthetic waxes based on crude montan wax and polyolefin waxes. The preferred oxidized semi-synthetic wax based on crude montan wax has the following characteristic data: drop point 79 to SCC acid number 115 to 155 mg of KOH/g hydrolysis number 140 to 175 mg of KOH/g density 0.97 to 1.03 g/cw? The preferred oxidized wax based on polyolefin wax has the following characteristic data: drop point 95 to 13CC acid number 15 to 70 mg of KOH/g hydrolysis number 25 to 115 mg of KOH/g density 0.90 to 1.03 g/cm^ The preferred oxidized semi-synthetic wax based on crude montan wax is formed by oxidative bleaching of crude montan wax. Waxes of this type have been commercially obtainable for many years. The preferred oxidized wax based on polyolefin wax is formed by bulk polymerization in the Ziegler low pressure process. The resulting polyolefin wax is converted into oxidized products by treatment of the melt with air. These waxes have also been commercially obtainable for many years. The oxidized wax is added to the polymer in a concentra¬tion of 0.001 to 5 phr (parts per 100 parts of resin), preferably 0.01 to 0.5 phr. In addition, the molding composition according to the invention can also con^rise further additives, such as, for example, antioxideuits, for exeimple alkylated monophenols, alkylated hydro-quinones, hydroxylated diphenyl thioethers, alkylidene-bisphenols, benzyl compounds, acylaminophenols, esters of p-(5-t-butyl-4-hydroxy-3-methylphenyl)propionic acid, amides of /S-(3,5-di-t-butyl-4-hydroxyphenyl)propionic acid, UV absorbers and light stabilizers, for example 2-(2'-hydroxyphenyl)benzotriazoles, 2-hydroxybenzophenones, oxalic disunides, esters of unsiobstituted or sxabstituted benzoic acids, acrylates, nickel compounds, sterically hindered amines (HALS), metal deactivators, phosphates and phosphites, peroxide-destroying compounds, basic costabilizers, nucleating agents, fillers and reinforcing materials, plasticizers, optical brighteners, flameproofing agents, antistatics, blowing agents, lubricants and pigments. The oxidized waxes to be used according to the invention and, if appropriate, the other additives are incorporated by the methods customary for compounding polyolefins. They are preferadsly added during the granulation. The polyolefin molding composition according to the invention results in finished components which no longer show a peeling effect. Accordingly the present invention provides A polyolefin molding composition with a reduced tendency to peel, comprising 100 parts by weight of an olefin polymer and 0.001 to 5 parts by weight of an oxidized wax selected from oxidized fiiUy synthetic wax, an oxidized semi¬synthetic wax and an oxidized polyolefm wax. The following examples are intended to illustrate the invention. The "peeling effect" is characterized in the following manner. Drums having a capacity of 200 1 are produced from a polyolefin molding composition according to the invention at different throughputs on an extrusion_ blow molding machine. The drums are then assessed visu¬ally with a classification Into a "peel rating" of between 1 and 5. The rating 1 means that no filaments at all are to be observed on the drum surface. The drum surface Is smooth and Intact. Classification into ratings 2-5 is made according to the frequency of the occurrence of polymer filaments on the drum surface and the thick¬ness thereof. Example 1 A polyethylene having an MFR 190/21.6 of 2.0 g/10 minutes and a density of 0.950 g/cm^ was mixed in a mixing con¬tainer with 0.12 phr of pentaerythrltol tetrakis[3-(3-,5-di-t-butyl-4-hydroxyphenyl)propionate] and 0.2 phr of an oxidized polyethylene wax (density 0.97 - 0.99 g/cxc?, AN 15 - 17 mg of KOH/g, HN 20 - 35 mg of KOH/g) and the mixture was granulated at 290°C by means of an extruder. 400 kg of these granules were processed to give 200 1 drums on an extrusion blow molding line. The drums thus obtained had a smooth inner and outer surface. The "peel rating" was 1. Example 2 A polyethylene having an MFR 190/21.6 of 2.0 g/10 minutes and a density of 0.950 g/cm was mixed in a mixing con¬tainer with 0.12 phr of pentaezythritol tetrakis[3-(3-,5-di-t-butyl-4-hydroxyphenyl)propionate] and 0.2 phr of an oxidized polyethylene wax (density 0.97 - 0.99 g/cm^, AN 15 - 17 mg of KOH/g, HN 20 - 35 mg of KOH/g) and the mixture was granulated together with 0.8 phr of a blue batch (masterbatch with blue pigment) at 290°C by means of an extruder. 400 kg of these blue granules were processed to give 200 1 drums on an extrusion blow molding line. The blue drums thus obtained had a smooth inner and outer surface. The "peel rating" was 1. Comparison example A The same polyethylene as In Examples 1 and 2 was stabilized in a mixing container with 0.12 phr of pentaerythritol tetrakis[3-(3-,5-di-t-butyl-4-hydroxyphenyl)propionate] and the mixture was granulated at 290°C by means of an extruder. 400 kg of these granules were extruded to give 200 1 drtims on an extrusion blow molding line. The drums thus obtained had a "peeling effect" of rating 3, 4 or 5 on the inner or outer surface. Comparison example B The same polyethylene as in Examples 1 and 2 was mixed in a mixing container with 0.12 phr of pentaezythritol-tetrakis [3- (3-, 5-di-t-butyl-4-hydroxyphenyl) propionate] and together with 0.8 phr of a blue batch (masterbatch with blue pigment) , and the mixture was granulated at 290°C by means of an extruder. 400 kg of these blue granules were extruded to give 200 1 drums on an extrusion blow molding unit. The blue drums thus obtained had a "peeling effect" of rating 3, 4 or 5 on the inner or outer surface. WE CLAIM: 1. A polyolefin molding composition with a reduced tendency to peel, comprising 100 parts by weight of an olefin polymer and 0.001 to 5 parts by weight of an oxidized wax selected from oxidized fully synthetic wax, an oxidized semi-synthetic wax and an oxidized polyolefin wax such as herein described. 2. The polyolefin molding composition as claimed in claim 1, in which the oxidized wax is an oxidized polyolefin wax such as herein described. 3. The polyolefm molding composition as claimed in claim 1, in which the olefin polymer is selected trom polyethylene, polypropylene, polybut-1-ene, polyhex-1-ene, poly-4-methylenepent-1-ene, polyoct-1-ene or a copolymer thereof 4. A process for preparing the polyolefin molding composition having reduced peel tendency as claimed in any one of the preceding claims during extrusion of a polyolefin molding composition, said process comprising the steps of adding 0.001 to 5 phr of an oxidized wax to an olefm polymer. 5. The process as claimed in claim 4, wherein the oxidized wax is an oxidized polyolefin wax such as herein described. 6. A poly olefin molding composition with a reduced tendency to peel substantially as herein described and exemplified 7. A process for preparing a polyolefm molding composition as herein described and exemplified.

Documents:

1396-mas-1995 abstract.pdf

1396-mas-1995 claims.pdf

1396-mas-1995 correspondence-others.pdf

1396-mas-1995 correspondence-po.pdf

1396-mas-1995 description(complete).pdf

1396-mas-1995 form-1.pdf

1396-mas-1995 form-26.pdf

1396-mas-1995 form-4.pdf

1396-mas-1995 form-9.pdf

1396-mas-1995 petition.pdf