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Improvements of nucleating and/or clarifying agents for polymers, in particular by optimisation of their particle size distribution and synergistic mixtures thereof

IP.com Disclosure Number: IPCOM000031692D
Publication Date: 2004-Oct-05
Document File: 7 page(s) / 27K

Publishing Venue

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Improvements of nucleating and/or clarifying agents for polymers, in particular by optimisation of their particle size distribution and synergistic mixtures thereof

The compounds of the formula (I), (II) or (III) disclosed in WO-A-04/072,168 or the compounds of the formula (I), (IA) or (IB) disclosed in US-A-2004/0,063,830 or the compounds of the formula (I) disclosed in WO-A-03/102,069 or the compounds of the formula (1), (2) or (3) disclosed in US-A-5,973,076 are particularly useful as nucleating agents and/or clarifying agents in form of ultrafine powders. Ultrafine powder means, for example, a powder which is characterized by a d97 of 30 microns or less and a mean particle size of 15 microns or less as described in US‑A‑5,310,950. Preferred embodiments relate to a d97 of 20 microns or less and a mean particle size of 10 microns or less, or a d97 of 10 microns or less and a mean particle size of 6 microns or less. The specific bulk densities of such ultrafine powders are typically less than 0.8 kg/L, more preferably less than 0.5 kg/L, but most preferably less than 0.3 kg/L.

An ultrafine powder of the nucleating and/or clarifying agents described in the specific working examples of WO-A-04/072,168 or US-A-2004/0,063,830 or WO‑A‑03/102,069 or US-A-5,973,076 is of particular interest.

The aforementioned nucleating agents and/or clarifying agents can  be blended with one or more additional components as listed below, in order to obtain synergistic mixtures eventually showing enhanced efficiency for their use in polymers, particularly as nucleating and/or clarifying systems of polyolefins, more particularly of homo and copolymers of polypropylene, polybutylene and polyethylene, but most particularly of homo and copolymers of polypropylene.

Such blends can be prepared from the individual ultrafine powdery nucleating agents and/or clarifying agents described above with one or more of the synergists in its conventional form or equally milled into an ultrafine powdery form. But most preferably, the blending process of the nucleating agents and/or clarifying agents with one or more of the synergists is first completed with all components in their conventional form according to common techniques. And only subsequently, the resulting blend is finally transformed into an ultrafine powder according to the preferences described in US‑A‑5,310,950.

The following combinations of compounds are of particular interest as synergistic nucleating and/or clarifying systems:

1) Each of the compounds of the formula (I), (IA) or (IB) specifically disclosed in US‑A‑2004/0,063,830, in particular each of the compounds disclosed in the working examples,

in combination with

1,3:2,4-bis(benzylidene)sorbitol, commercially available as Irgaclear D (RTM), Millad 3905 (RTM) and Gell All D (RTM).

2) Each of the compounds of the formula (I), (IA) or (IB) specifically disclosed in US‑A‑2004/0,063,830, in particular each of the compounds disclosed in the work...