Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2000-03-29
2003-08-12
Woodward, Ana (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C106S483000, C106S484000, C106S487000, C523S212000, C523S213000, C523S216000, C524S447000, C524S449000
Reexamination Certificate
active
06605655
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a polyamide resin composition having a low specific gravity and having high-level stiffness and ductility, and to a method for producing it.
BACKGROUND ART
Recently, in the art, finely dispersing a phyllosilicate in polyamide on the order of nanometers has been tried for enhancing the mechanical strength of the resin composition. The clay-polyamide composite could have much increased stiffness, but is problematic in that its impact strength and tensile elongation are poor as the clay layer-to-polyamide adhesiveness is low in the interface of the two. To improve the tenacity of the clay-polyamide composite, adding an elastomer to the composite is tried in Japanese Patent Laid-Open Nos. 29457/1990 and 12883/1996. Adding an elastomer thereto could improve the tensile elongation and the impact resistance of the clay-polyamide composite, but is still problematic in that it lowers the stiffness of the resulting composite as compared with that of the original composite not containing an elastomer. In Japanese Patent Laid-Open No. 331092/1995, tried is organizing a phyllosilicate, which has a functional group capable of reacting with a matrix resin, with an organic onium salt, followed by adding the thus organically modified phyllosilicate to a thermoplastic resin to thereby improve the stiffness and the ductility of the resin. At present, however, no one could obtain a resin material having both high-level stiffness and high-level ductility.
Given that situation, the present invention is to solve the problems with polyamide resin compositions noted above, that is, to improve both the contradictory properties, stiffness and ductility, of polyamide resin compositions.
DISCLOSURE OF THE INVENTION
The invention provides a polyamide resin composition comprising a melt blend of (A) a polyamide resin, (B) a phyllosilicate, and (C) an olefin compound having a carboxylic acid anhydride group in the molecule or a polymer of the olefin compound, in which the phyllosilicate (B) has a reactive functional group bonded thereto and is such that the exchangeable metal ions existing in the interlayers are ion-exchanged with organic onium ions, and also provides a method for producing the composition.
BEST MODES OF CARRYING OUT THE INVENTION
“Weight” as referred to herein indicates “mass”.
The polyamide resin (A) for use in the invention is meant to indicate polyamide to be prepared from starting materials of essentially an amino acid, a lactam or a diamine, and a dicarboxylic acid. Specific examples of the starting materials include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, para-aminomethylbenzoic acid, etc.; lactams such as &egr;-caprolactam, &ohgr;-laurolactam, etc.; aliphatic, alicyclic or aromatic diamines such as tetramethylenediamine, hexamethylenediamine, 2-methylpentamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4-/2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, metaxylylenediamine, paraxylylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminopropyl)piperazine, aminoethylpiperazine, etc.; aliphatic, alicyclic or aromatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid, dodecane-diacid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium-sulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, etc. In the invention, nylon homopolymers or copolymers to be derived from those starting materials are used either singly or as their mixtures.
Specific examples of polyamide resins especially useful in the invention are polycapramide (nylon 6), polyundecanamide (nylon 11), polylauramide (nylon 12), polyhexamethylenadipamide (nylon 66), polytetramethylenadipamide (nylon 46), polyhexamethylenesebacamide (nylon 610), polyhexamethylenedodecamide (nylon 612), polyhexamethyleneterephthalamide/polycapramide copolymer (nylon 6T/6), polyhexamethyleneterephthalamide/polydodecanamide copolymer (nylon 6T/12), polyhexamethylenadipamide/polyhexamethyleneterephthalamide copolymer (nylon 66/6T), polyhexamethylenadipamide/polyhexamethylenisophthalamide copolymer (nylon 66/6I), polyhexamethylenadipamide/polyhexamethylenisophthalamide/-polycapramide copolymer (nylon 66/6I/6), polyhexamethylenadipamide/polyhexamethyleneterephthalamide /polyhexamethylenisophthalamide copolymer (nylon 66/6T/6I), polyhexamethyleneterephthalamide/-polyhexamethylenisophtha lamide copolymer (nylon 6T/6I), polyhexamethyleneterephthalamide/poly(2-methylpentamethyle ne)terephthalamide copolymer (nylon 6T/M5T), polyhexamethyleneterephthalamide/-polyhexamethylenesebacam ide/polycapramide copolymer (nylon 6T/610/6), polyhexamethyleneterephthalamide/polydodecanamide/-polyhexamethylenadipamide copolymer (nylon 6T/12/66), polyhexamethyleneterephthalamide/polydodecanamide/-polyhexamethylenisophthalamide copolymer (nylon 6T/12/6I), polyxylylenadipamide (nylon XD6), as well as their mixtures and copolymers, etc.
Especially preferred are nylon 6, nylon 66, nylon 610, nylon 6/66 copolymer, nylon 6/12 copolymer, nylon 66/6I/6 copolymer, as well as copolymers having hexamethyleneterephthalamide units, such as nylon 6T/66 copolymer, nylon 6T/6I copolymer, nylon 6T/6 copolymer, nylon 6T/12 copolymer, nylon 6T/12/66 copolymer, nylon 6T/12/6I copolymer, etc. Practically, it is often preferable to use these polyamide resins in the form of their mixtures, depending on the desired characteristics such as moldability, heat resistance, tenacity, surface smoothness and other properties of the resins.
The degree of polymerization of the polyamide resin for use in the invention is not specifically defined. Preferably, however, the relative viscosity of the resin, as measured in a solution of concentrated sulfuric acid to have a resin concentration of 1%, at 25° C., may fall between 1.5 and 5.0, more preferably between 2.0 and 4.0.
The component (B), phyllosilicate for use in the invention is typically a layered phyllosilicate comprising layers of magnesium silicate or aluminium silicate. In this, each layer is a 2:1 tabular crystal layer with, for example, one tetrahedral silicate sheet being sandwiched by a pair of octahedral sheets containing an element selected from aluminium, magnesium, lithium and the like, in which the interlayers in each tabular crystal layer contain exchangeable cations. In general, this is so constructed that a plurality of tabular layers each having a width of from 0.05 to 0.5 &mgr;m and a thickness of from 6 to 15 angstroms are layered in order. Its cation exchange capacity generally falls between 0.2 and 3 meq/g, but preferably between 0.8 and 1.5 meq/g.
Specific examples of phyllosilicates usable herein are the family of smectites (e.g., montmorillonite, beidellite, saponite, hectorite, sauconite); the family of vermiculites (e.g., vermiculite); the family of micas (e.g., muscovite, paragonite, phlogopite, biotite, lepidolite); the family of clintonites (e.g., margarite, clintonite, anandite); the family of chlorites (e.g., donbassite, sudoite, cookeite, clinochlore, chamosite, nimite). These phyllosilicates may be natural ones, synthetic ones and even modified ones. Specific examples of synthetic phyllosilicates are swellable fluoromicas such as Li/fluorotaeniolite, Na/fluorotaeniolite, Na/tetrasilicofluoromica, Li/tetrasilicofluoromica, etc. Of those preferred are montmorillonite and Na-type tetrasilicofluoromica; and more preferred is montmorillonite.
The phyllosilicates for use in the invention have a reactive functional group bonded thereto, and in these, the exchangeable metal ions existing in the interlayers are ion-exchanged with organic onium ions. The phyllosilicates having a reactive function group bonded thereto are such that a compound having a reactive functional group is chemi
Kato Koya
Nishimura Toru
Yamanaka Toru
Piper Rudnick LLP
Toray Industries Inc.
Woodward Ana
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