Chemistry: natural resins or derivatives; peptides or proteins; – Natural resins or derivatives – Rosin or derivative used as starting material in process – or...
Patent
1998-04-08
1999-12-07
Nutter, Nathan M.
Chemistry: natural resins or derivatives; peptides or proteins;
Natural resins or derivatives
Rosin or derivative used as starting material in process, or...
530224, 530225, 524270, 524274, 524764, 264464, C08L 9304, C08L 2300, C08K 509
Patent
active
059985763
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to novel and useful rosin-based molecular crystals, a polyolefin resin nucleating agent containing such rosin-based molecular crystals, a polyolefin resin composition containing said nucleating agent either alone or in combination with a calcium salt, and a molding thereof.
The term "molecular crystal" as used herein means a form of a complex of different molecular species A and B, and is a generic term denoting a crystal of a molecular compound formed when the respective molecules of compounds A and B, which can exist independently in a stable form, are bound together in a certain molar ratio (A/B) by physical intermolecular forces.
BACKGROUND ART
The nucleating agent for polyolefin resins is an additive for increasing the rate of crystallization of polyolefin resins and for improving their optical properties such as clarity and gloss, and their mechanical characteristics such as rigidity and elastic modulus.
For use as such a nucleating agent, several compositions each predominantly composed of rosin and/or a metal salt of rosin-based material have recently been proposed (Japanese Unexamined Patent Publications (Kokai) No. H7-330967, No. H7-331081, No. H8-277343, No. H8-277366).
However, the polyolefin resin nucleating agents described in the above patent literature, namely rosin and/or its metal salts, remain to be improved in terms of the heat resistance, oxidation resistance, moisture barrier properties, and blocking resistance. Furthermore, because of their high volatility and sublimability, those nucleating agents have the disadvantage of poor stability and causing poor workability in the processing of the polyolefin resin. Moreover, when rosins or their metal salts proposed are used alone, the effect of clarifying polyolefin resins is not necessarily fully satisfactory. In the case of a mixture of a rosin and a rosin metal salt, its dispersibility in resin is not good enough so that spots apparently attributable to the undispersed nucleating agent are formed in the resin molded products. Therefore, for the purpose of producing the intrinsic nucleating effects, the following contrivances have been proposed (Japanese Unexamined Patent Publications (Kokai) No. H7-330967, No. H7-331081, No. H8-277343, No. H8-277366).
(1) Melt-kneading with polyolefin resin is performed at least twice.
(2) Two or more rosin acid metal salts of different metal species are used in combination.
(3) At least one compatibilizer selected from the class consisting of rosin glycerol esters, antistatic agents, higher fatty acid metal salts, polyolefin wax, or hydrogenated petroleum resin is added to the nucleating agent.
However, any of those nucleating agents still has a great room for further improvement.
DISCLOSURE OF THE INVENTION
The object of the present invention is to overcome the above-mentioned disadvantages and to provide a novel and useful rosin type polyolefin resin nucleating agent having excellent effects of improving clarity, gloss, rigidity and moldability, a polyolefin resin composition containing said nucleating agent, and a molded article as molded from said composition.
The inventors made an extensive investigation of characteristics of various rosin compounds for accomplishing the above object, and discovered that the process of phase separation by crystallization of a solution or a melt containing a specific rosin-based type resin acid and an alkali metal salt thereof comprises not only the hitherto-known processes 1) and 2) mentioned below but also the following processes 3) and 4).
1) Formation of crystals of the rosin-based resin acid.
2) Formation of crystals of an alkali metal salt of the rosin-based resin acid.
3) Formation of molecular crystals each composed of the rosin-based resin acid and the alkali metal salt thereof in a molar ratio of 3/1.
4) Formation of molecular crystals each composed of the rosin-based resin acid and the alkali metal salt thereof in a molar ratio of 1/1.
In addition, the inventors succeeded in establishing a technology f
REFERENCES:
patent: 5606016 (1997-02-01), Maeda et al.
Ishikawa Masahide
Kobayashi Toshi-aki
Sadamitsu Kiyoshi
New Japan Chemical Co. Ltd.
Nutter Nathan M.
LandOfFree
Rosin-based molecular crystals, nucleating agent for polyolefin does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rosin-based molecular crystals, nucleating agent for polyolefin , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rosin-based molecular crystals, nucleating agent for polyolefin will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-825235