Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2000-03-01
2003-06-10
Medley, Margaret (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C524S212000, C524S405000, C524S436000, C524S437000
Reexamination Certificate
active
06576691
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a flame resistance polymer composition. More particularly, the present invention relates to a flame resistant polymer composition having excellent flame resistance; free from production of toxic gas such as halogen gas and the like when burnt; free from environmental pollutant substances such as phosphorus, lead, and the like; exhibiting superior well-balanced characteristics such as molding processability, tensile strength, pliability (anti-whitening on folding), flexing resistance, flexibility, and the like; and useful for variety of applications such as electric wire coating materials for interconnect wiring in equipment or harnesses for vehicles, industrial materials for insulating tapes, and the like.
2. Description of the Background Art
Owing to excellent physical and chemical properties, polyolefin-based polymers (resins) are fabricated into films, sheets, pipes, containers, electric wires, cables and the like by means of various methods such as extrusion molding, injection molding, and the like, and are used as household utensils and industrial materials. Because these polyolefin resins are easily flammable, various methods for making the resins flame resistant have been disclosed. In a most common method known in the art, a halogen-containing organic flame retardant is used together with polyolefin resins. Although the use of a small amount of such a flame retardant exhibits an excellent flame resistant effect, the flame retardant has a problem of generating corrosive and toxic gas when burnt.
More recently, a flame resistant propylene resin composition comprising no halogen-containing organic flame retardant has been disclosed (Japanese Patent Application Laid-open No. 263851/1990). However, because this composition contains a phosphorus flame retardant which exhibits hygroscopic properties, the composition requires a measure for preventing bleed-out. Although a certain effect of bleed-out prevention can be attained by the addition of an olefinic rubber and a silane coupling agent, the resulting composition is not necessarily satisfactory from the viewpoint of characteristics such as pliability, flexibility, and the like, as well as from the viewpoint of environmental harmonization.
Another example is a flame resistant polypropylene composition comprising propylene homopolymer, ethylene-propylene copolymer rubber, bis(2,3-dibromopropyl)ether of tetrabromobisphenol S, and antimony trioxide (Japanese Patent Application Laid-open No. 183337/1981). However, because bis(2,3-dibromopropyl)ether of tetrabromobisphenol S which is used in this composition as a flame retardant is a suspected environmental hormone, the composition is not necessarily satisfactory from the viewpoint of environmental harmonization. In addition, although the composition exhibits improved impact strength due to the use of an ethylene-propylene copolymer rubber, the flexibility which is required for wiring and fabrication when the composition is used as an electric wire coating material is not necessarily satisfactory.
Furthermore, a method of using a hydrated inorganic metal compound such as aluminum hydroxide or magnesium hydroxide as a non-pollutant and environmentally harmonious flame retardant has been disclosed (for instance, Japanese Patent Application Laid-open No. 279736/1998). However, a large amount of such a hydrated inorganic metal compound must be added to a flame resistance composition to ensure adequately high flame resistance. This not only results in decrease in the mechanical properties, particularly tensile strength, but also impairs molding processability.
The present invention has been achieved in view of this situation and has an objective of providing a flame resistant polymer composition having excellent flame resistance; free from production of toxic gas such as halogen gas and the like when burnt; free from environmental pollutant substances such as phosphorus, lead, and the like; exhibiting superior well-balanced characteristics such as molding processability, tensile strength, pliability (anti-whitening on folding), flexing resistance, flexibility, and the like; and useful for variety of applications such as electric wire coating materials for interconnect wiring in equipment or harnesses for vehicles, industrial materials for insulating tapes, and the like.
SUMMARY OF THE INVENTION
As a result of extensive studies, the present inventors have found that a flame resistant polymer composition generating no toxic gas when burnt, being free from environmentally pollutant substances, and satisfying all of the above characteristics can be obtained by a resin composition comprising (A) 100 parts by weight of a mixture which comprises a polyolefin-based polymer and a specific hydrogenated conjugated diene polymer and/or a random copolymer of ethylene and &agr;-olefin having 3-10 carbon atoms, and (B) 5 parts by weight or more of an inorganic flame retardant. This finding has led to the completion of the present invention. Specifically, the following flame resistance polymer compositions are provided according to the present invention.
(1) A flame resistant polymer composition comprising: (A) 100 parts by weight of a mixture which comprises 1-99 wt % of (a-1) an olefin polymer and 1-99 wt % of (a-2) a hydrogenated conjugated diene polymer in which 80% or more of double bonds of the conjugated diene are saturated or (a-3) a random copolymer of ethylene and &agr;-olefin having 3-10 carbon atoms, or both (a-2) and (a-3); and (B) 5 parts by weight or more of an inorganic flame retardant.
(2) The flame resistant polymer composition described in (1) above, wherein the olefin polymer (a-1) is a mixture of a non-modified polyolefin and a modified polyolefin containing a functional group.
(3) The flame resistant polymer composition described in (2) above, wherein the content of the modified polyolefin in the mixture is 5-150 parts by weight for 100 parts by weight of the non-modified polyolefin.
(4) The flame resistant polymer composition described in (2) above, wherein the functional group in the modified polyolefin is at least one group selected from the group consisting of an acid anhydride group, carboxyl group, hydroxyl group, amino group, isocyanate group, and epoxy group.
(5) The flame resistant polymer composition described in (1) above, wherein the content of side chain vinyl bond of the conjugated diene portion before hydrogenation in the hydrogenated conjugated diene polymer (a-2) in component (A) is 55 wt % or more.
(6) The flame resistant polymer composition described in (1) above, wherein the random copolymer of ethylene and &agr;-olefin having 3-10 carbon atoms (a-3) in component (A) is a random copolymer of ethylene and 1-butene or a random copolymer of ethylene and 1-octene, or both.
(7) The flame resistant polymer composition described in (1) above, wherein the inorganic flame retardant (B) comprises magnesium hydroxide or aluminum hydroxide, or both.
(8) The flame resistant polymer composition described in (2) above, wherein the surface of the inorganic flame retardant (B) is treated with a silane coupling agent.
(9) The flame resistant polymer composition described in (7) above, wherein the surface of the inorganic flame retardant (B) is treated with a silane coupling agent.
Other objects, features and advantages of the invention will hereinafter become more readily apparent from the following description.
DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS
The flame resistance polymer composition of the present invention will now be described in more detail by way of embodiments.
The flame resistant polymer composition of the present invention comprises (A) 100 parts by weight of a mixture which comprises 1-99 wt % of (a-1) a polyolefin-based polymer and 1-99 wt % of (a-2) a hydrogenated conjugated diene polymer in which 80% or more of double bonds of the conjugated diene are saturated or (a-3) a random copolymer of ethylene and &agr;-olefin having 3-10 carbon atoms, or
Kodama Kazuhisa
Nakashima Hiroki
JSR Corporation
Medley Margaret
LandOfFree
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