Polypropylene composition with low surface energy
AssigneeBorealis Technology Oy
InventorsWerner Posch, Manfred Stadlbauer, Stefan Schiesser
Life of this patent
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Abstract
Polypropylene composition comprising a) an isotactic polypropylene (iPP) produced in the presence of a single-site catalyst and said isotactic polypropylene (iPP) has a mean isotactic block length between two structural chain defects, as a statistical average, greater than 70, and b) an atactic polypropylene (aPP) with an absorbance ratio of the absorption band at 998 cm−1 to the absorption band at 973 cm−1 [A998/A973] below 0.80 wherein the weight ratio of said atactic polypropylene to the sum of said atactic polypropylene and said isotactic polypropylene (aPP/(aPP+iPP)) is at least 0.50 wt.-%.
Claims10
Article selected from the group consisting of a refrigerator, a dishwasher and a washing machine wherein the article comprises a polypropylene composition having a reduced surface energy, comprising:
- a mixture of:
- (a) an isotactic polypropylene (iPP) produced in the presence of a single site metallocane catalyst having a molecular weight distribution (MWD) of below 4.00 and a mean isotactic block length between two structural chain defects, as a statistical average, greater than 70, and
- b) an atactic polypropylene (aPP) with an absorbance ratio of the absorption band at 998 cm−1 to the absorption band at 973 cm−1 (A998/A973) below 0.10,
- wherein the weight ratio of said atactic polypropylene to the sum of said atactic polypropylene and said isotactic polypropylene (aPP/(aPP+iPP)) is 0.50 to 9.00 wt.-%, and
- wherein the polypropylene composition has surface energy of between 23.88 and 27 mN/m.
Process for the reduction of surface energy of a polypropylene composition used in the manufacture of a refrigerator, a dishwasher, or a washing machine, comprising:
- (a) providing an atactic polypropylene (aPP) with an absorbance ratio of the absorption band at 998 cm−1 to the absorption band at 973 cm−1 (A998/ A973) below 0.10,
- (b) providing an isotactic polypropylene (iPP) produced in the presence of a single site metallocene catalyst having a molecular weight distribution (MWD) of below 4.00 and a mean isotacic block length between two structural chain defects, as a statistical average, greater than 70;
- and,
- (c) reducing the surface energy of said isotactic polypropylene by mixing the atactic polypropylene (aPP) with the isotactic polypropylene (iPP) in an amount to provide a weight ratio of said atactic polypropylene to the sum of said atactic polypropylene and said isotactic polypropylene (aPP/(App+iPP)) of 0.50 to 9.00 wt.-%;
- and
- wherein the obtained polypropylene composition has a surface energy of between 23.88 and 27 mN/m.
Dependencies are inferred from the claim text.