Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Reexamination Certificate
1998-10-23
2001-03-27
Gorr, Rachel (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
C525S242000, C525S245000, C525S247000
Reexamination Certificate
active
06207753
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an aromatic vinyl resin material and an aromatic vinyl resin molded product, and more particularly to an aromatic vinyl resin material that is endowed with excellent heat resistance, solvent resistance, toughness, tensile elongation, and transparency, and to an aromatic vinyl resin molded product thereof.
2. Related Art
Previously, the present inventors successfully developed a styrene polymer having a high syndiotacticity (Japanese Patent Application Laid-Open (kokai) Nos. 62-104818, 63-241009). The styrene polymer having a syndiotactic structure (hereinafter simply referred to as “syndiotactic polystyrene” or “SPS”) is endowed with excellent heat resistance and solvent resistance, but does not exhibit sufficient toughness or elongation. In addition, it has poor compatibility with other resins; therefore its use has inevitably been limited. When SPS is used for producing a film that requires transparency, SPS is cooled rapidly from the molten state to acquire transparency. However, the thus-obtained film has a drawback in that it is brittle.
In order to overcome this drawback, the present inventors succeeded in endowing the aforementioned styrene polymer having a syndiotactic structure with toughness by copolymerizing styrene with an olefin (Japanese Patent Application Laid-Open (kokai) Nos. 3-7705, 4-130114, 4-300904).
However, the thus-obtained random or block copolymer of styrene and an olefin suffers insufficient controllability of the copolymerization composition as well as a low copolymerization-modification ratio (i.e., percentage of modifier olefins in the resultant copolymer), leading to insufficient improvement in toughness, elongation, and compatibility with other resins.
There have been proposed a large number of compositions in which a rubber-like elastic substance or thermoplastic resin is added to SPS (Japanese Patent Application Laid-Open (kokai) Nos. 01-146944 and 01-279944). However, due to lack of an effective compatibility-enhancing agent, dispersion of thermoplastic resin or the like is insufficient, resulting in deterioration in transparency.
There have also been proposed graft copolymers in which a styrene monomer is graft-copolymerized with a polymer bearing double bonds in side chains, as well as block copolymers in which a styrene monomer is block-copolymerized with a macromonomer bearing polymerization-active terminal vinyl groups (Japanese Patent Application Laid-Open (kokai) Nos. 05-247147 and 05-295056). However, the copolymers disclosed in the above publications are inhomogeneous in copolymer composition and exhibit insufficient graft ratio, resulting in insufficient improvement in targeted properties such as toughness, elongation, and impact resistance.
In view of the foregoing, an object of the present invention is to provide an aromatic vinyl resin material for producing a molded product which is endowed with heat resistance, solvent resistance, toughness, tensile elongation, and transparency, as well as to provide a molded product of the resin material.
SUMMARY OF THE INVENTION
The present inventors carried out extensive studies, and as a result, found that toughness of a certain resin material is related to frequency dependency of storage modulus of the material and that the heat of fusion &Dgr;H over a certain temperature range and the amount of graft components present in the polymer are related to good toughness, elongation, and transparency, thus achieving the present invention.
Specifically, the present invention provides:
(1) an aromatic vinyl resin material which satisfies the relationship represented by the following expression:
SG
value=log[
G
′(1.0)/
G
′(0.1)]≦0.6
wherein G′(1.0) is a storage modulus as measured at a temperature of 300° C., a strain &ggr; of 20%, and a frequency of 1.0 Hz, and G′(0.1) is a storage modulus as measured at a temperature of 300° C., a strain &ggr; of 20%, and a frequency of 0.1 Hz;
(2) an aromatic vinyl resin material having the following properties:
1) the heat of fusion &Dgr;H as measured over the range 200-295° C. with a differential scanning calorimeter is 8 to 50 (J/g),
2) in
1
H-NMR performed on the residue obtained from Soxhlet extraction using cyclohexane,
B/A<0.49
wherein A is an integrated value of a peak appearing at 1.0-1.7 (ppm) and B is an integrated value of a peak appearing at 1.8-2.1 (ppm), and
3) a tensile elongation of not less than 5%;
(3) an aromatic vinyl resin material having the following properties:
1) the heat of fusion &Dgr;H as measured over the range 200-295° C. with a differential scanning calorimeter is 8 to 50 (J/g),
2) in
1
H-NMR performed on the fraction eluted at 50° C. or higher through temperature rising election fraction by use of o-dichlorobenzene (hereinafter referred to simply as fractionation by o-dichlorobenzene), B/A<0.49 wherein A is an integrated value of a peak appearing at 1.0-1.7 (ppm) and B is an integrated value of a peak appearing at 1.8-2.1 (ppm), and
3) a tensile elongation of not less than 5%;
(4) an aromatic vinyl resin material as described above in any of (1) to (3), wherein the aromatic vinyl resin material is a graft copolymerization product of an aromatic vinyl monomer (a) and an ethylene copolymer macromer (b);
(5) an aromatic vinyl resin material as described above in (4), in which the ethylene copolymer macromer (b) is a copolymerization product of ethylene, a diene monomer, and an optional aromatic vinyl monomer and optional &agr;-olefin;
(6) an aromatic vinyl resin material as described above in any of (1) to (3), which has a composition composed of (A) an aromatic vinyl polymer, (B) an ethylene copolymer having a diene-monomer-derived vinyl group in the molecular chain, and (C) a graft copolymerization product of an aromatic vinyl monomer (a) and an ethylene copolymer macromer (b);
(7) an aromatic vinyl resin material as described above in any of (4) to (6), in which a moiety derived from an aromatic vinyl monomer predominantly has a syndiotactic structure;
(8) an aromatic vinyl resin material having a composition composed of an aromatic vinyl resin material as described above in any of.(l) to (7) and a styrene polymer predominantly having a syndiotactic structure and/or a rubber-like elastic substance; and
(9) a molded product obtained through molding of an aromatic vinyl resin material as described above in any of (1) to (8).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention will next be described.
1. Aromatic Vinyl Resin Material
(1) An aromatic vinyl resin material according to the present invention is such that the storage modulus (G′(1.0)) as measured at a temperature of 300° C., a strain &ggr; of 20%, and at a frequency of 1.0 Hz and the storage modulus (G′(0.1)) as measured at a temperature of 300° C., a strain &ggr; of 20%, and at a frequency of 0.1 Hz satisfy the relationship represented by the following expression.
SG
value=log[
G
′(1.0)/
G
′(0.1)]≦0.6
wherein the storage modulus G′(dyne/=m) is measured at a temperature of 300° C., a strain &ggr; of 20%, and a frequency ranging from 10-2 Hz to 102 Hz through use of a cone plate type rheometer (manufactured by Rheometric Scientific). G′(1.0) denotes a G′ value as measured at a frequency of 1.0 Hz. A test piece for measurement is manufactured in the following manner. Briefly, a sample to be measured is pelletized at 300° C. through use of a small-size kneader. The resultant pellets are pressed into a sheet (1.0 mm thick) at 300° C., obtaining a test piece.
(2) An aromatic vinyl resin material according to the present invention has the following properties:
1) The heat of fusion &Dgr;H as measured over the range 200-295° C. with a differential scanning calorimeter is 8 to 50 (J/g), preferably 10 to 40 (J/g), more preferably 15 to 30 (J/g).
The heat of fusion &Dgr;H as measured over the range 200-295° C. with a differential scanning calorime
Sera Masanori
Takebe Tomoaki
Teshima Hideo
Gorr Rachel
Idemitsu Petrochemical Co. Ltd.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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