Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2001-01-17
2003-12-23
Reddick, Judy M. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C523S206000, C524S401000, C524S413000, C524S424000, C524S425000, C524S437000, C524S444000, C524S450000
Reexamination Certificate
active
06667358
ABSTRACT:
TECHNICAL FIELD
The present invention relates to an olefin-type flame-retardant resin composition. More specifically, the invention relates to a flame-retardant resin composition which exhibits excellent mechanical strength, abrasion resistance and processibility despite it is blended with an inorganic compound, and exhibits an excellent shell-forming property when it is burned.
BACKGROUND ART
Olefin-type polymers have been widely used as electric insulating materials owing to their excellent electric properties, mechanical properties and processibility. In particular, materials exhibiting well-balanced strength, low-temperature properties, abrasion resistance and hardness are required for the electric wires and cables, and an ethylene/unsaturated ester random copolymer having such properties has been widely used.
However, the ethylene-type copolymer easily burns and must, hence, be treated to be flame-retardant when it is to be used as an electric insulating material. It has been known to blend the ethylene-type copolymer with an inorganic compound to make it flame-retardant. To obtain a sufficient degree of flame-retardant effect, the inorganic compound must be blended in large amounts which, however, results in spoiling the processibility and mechanical properties inherent in the ethylene-type copolymer.
To avoid such a problem, it has been attempted to treat the surface of the inorganic compound with which the ethylene-type copolymer is blended and to add a modified resin grafted with an unsaturated carboxylic acid such as maleic acid. When the surface of the inorganic compound is treated, the mechanical strength is improved but the abrasion resistance is not improved. When the acid-modified resin is blended, the mechanical strength and abrasion resistance are improved causing, the processibility to be greatly deteriorated.
A method has also been known to blend antimony oxide and a halide. In case fire breaks out, however, the composition is likely to generate toxic gas, which is not desirable.
Japanese Examined Patent Publication (Kokoku) No. 103273/1995 teaches a self-fire-extinguishing copolymer composition containing 0.02 to 25 parts by weight of a copolymer (without containing epoxy group) of an ethylene and at least one kind of monomer selected from an unsaturated carboxylic acid, a derivative thereof and a vinyl ester, and 0.001 to 3 parts by weight of a copolymer of an ethylene containing 0.5 to 50% by weight of an ethylenically unsaturated epoxylated compound and an ethylenically unsaturated epoxy compound per 100 parts by weight of the total amount of 70 to 20% by weight of an olefin polymer resin and/or an elastomer, and 30 to 80% by weight of a hydroxide of aluminum and/or magnesium or a blend thereof with not more than 30% by weight of magnesium carbonate. The above composition, however, has the object of suppressing the tendency of becoming white and improving the anti-freezing property without impairing abrasion resistance, but never suggests the flame-retardant resin composition having excellent mechanical strength, abrasion resistance, processibility and shell-forming property when burned, which is contemplated by the present invention.
SUMMARY OF INVENTION
It is therefore an object of the present invention to provide an olefin-type flame-retardant resin composition having excellent mechanical strength, abrasion resistance and processibility despite it is blended with an inorganic compound, and further exhibiting excellent flame-retardant property and shell-forming property when it is burned.
The shell-forming property when it is burned referred to in the present invention, stands for a property that forms a shell or a formed shell itself is hard as observing the burned state by eyes. Those compositions that melt and drip without forming shell cannot be regarded to have excellent shell-forming property.
According to the present invention, there is provided a flame-retardant resin composition which contains 25 to 250 parts by weight of (D) a flame-retardant inorganic compound per 100 parts by weight of a base resin composition containing 95 to 5% by weight of (A) a copolymer of an ethylene and a vinyl acetate and optionally other polar group-containing monomer, (B) 5 to 95% by weight of a copolymer of an olefin and an unsaturated carboxylic acid ester and optionally other polar group-containing monomer, and 0 to 49% by weight of (C) a thermoplastic resin other than the above copolymers.
In the flame-retardant resin composition of the present invention, it is desired that:
1. The copolymer (A) contains 20 to 98% by weight of an ethylene, 2 to 80% by weight of a vinyl acetate, and 0 to 40% by weight of the other polar group-containing monomer;
2. The other polar group-containing monomer in the copolymer (A) is an unsaturated carboxylic acid or a derivative thereof, carbon monoxide or a vinyl alcohol;
3. The copolymer (A) has a melt flow rate (MFR), at 190° C. under a load of 2160 g, of from 0.1 to 100 g/10 minutes;
4. The copolymer (B) contains 20 to 98% by weight of an ethylene, 2 to 80% by weight of an unsaturated carboxylic acid ester, and 0 to 60% by weight of other polar group-containing monomer;
5. The other polar group-containing monomer in the copolymer (B) is an unsaturated carboxylic acid, an anhydride thereof, a glycidyl ester thereof, a (meth)acrylonitrile, or carbon monoxide;
6. The copolymer (B) contains from 0.1 to 10% by weight of a butadiene, from 5 to 50% by weight of an unsaturated carboxylic acid ester, and from 40 to 95% by weight of a (meth)acrylonitrile;
7. The copolymer (B) has a melt flow rate (MFR), at 190° C. under a load of 2160 g, of from 0.1 to 100 g/10 minutes;
8. The thermoplastic resin (C) is an ethylene-type polymer other than the copolymer (A) and the copolymer (B);
9. The ethylene-type polymer is an ethylene-type polymer modified with an unsaturated carboxylic acid, a straight chain ethylene/&agr;-olefin copolymer, an ethylene/vinyl alcohol copolymer, or an aromatic group-containing ethylene-type copolymer; and
10. The flame-retardant inorganic compound (D) is a magnesium hydroxide, an aluminum hydroxide, a hydrotalcite-type complex hydroxide, basic magnesium carbonate or at least the one of the products thereof obtained by treating the surfaces with a fatty acid amide, a fatty acid salt, a fatty acid ester, a titanium coupling agent or a silane coupling agent.
The present invention further provides a flame-retardant resin composition comprising, as an essential component, an ethylene copolymer selected from:
(1) A parts by weight of an ethylene/vinyl acetate copolymer containing a mole % of a vinyl acetate,
(2) B parts by weight of an ethylene/alkyl ester of unsaturated carboxylic acid copolymer containing b mole % of an alkyl ester of unsaturated carboxylic acid and c mole % of other polar monomer (where c may be 0), and
(3) C parts by weight of an ethylene/vinyl acetate/alkyl ester of unsaturated carboxylic acid copolymer containing d mole % of a vinyl acetate, e mole % of an alkyl ester of unsaturated carboxylic acid and f mole % of other polar monomer (where f may be 0);
and optionally comprising:
(4) D parts by weight of an ethylene/polar monomer copolymer containing g mole % of other polar monomer and h mole % of a vinyl acetate (where h may be 0), and/or
(5) E parts by weight of an aromatic group-containing copolymer containing i mole % of an aromatic group-containing monomer,
the following ratio:
(
bB+eC
)/(
bB+eC+aA+dC+hD
)
being from 0.01 to 0.99, and said flame-retardant resin composition containing from 25 to 250 parts by weight of a flame-retardant inorganic compound per 100 parts by weight of the total amount of the copolymers (1) to (5).
In the flame-retardant resin composition of this embodiment, it is desired that:
1. The following ratio,
(
cB+fC+gD+iE
)/100
is in a range of not larger than 49; and
2. b is larger than a, A is present in a range of from 60 to 95 parts by weight, and B is present in a range of from 40 to 5 parts by weight (the total of the two is 100
DuPont-Mitsui Polychemicals Co.
Reddick Judy M.
Sherman & Shalloway
LandOfFree
Flame retardant resin composition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Flame retardant resin composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Flame retardant resin composition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3122617