Stock material or miscellaneous articles – Composite – Of addition polymer from unsaturated monomers
Reexamination Certificate
1999-05-04
2001-11-13
Thibodeau, Paul (Department: 1773)
Stock material or miscellaneous articles
Composite
Of addition polymer from unsaturated monomers
C428S213000
Reexamination Certificate
active
06316118
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to fire-retardant vinyl chloride resin moldings, more particularly, it relates to fire-retardant vinyl chloride resin moldings which satisfy the FM standard (evaluation criteria of fire-retardant property provided by Factory Mutual Research Corporation).
BACKGROUND OF THE INVENTION
Since vinyl chloride resin has excellent moldability, high mechanical strength and good chemical resistance and is inexpensive, it is broadly used in various fields, including semiconductor production apparatuses, as industrial materials, particularly as corrosion resistant industrial materials.
However, though vinyl chloride resin has fire-retardant property due to its high chlorine content, it has poor heat resistance so that it causes thermal decomposition when exposed to a temperature of 200° C. or more, thereby inducing smoke by organic matter and also generating corrosive gases such as chlorine gas and hydrogen chloride gas. Accordingly, when a fire starts in an apparatus which uses moldings of such a vinyl chloride resin, smoke and gas are generated due to decomposition of said resin.
With the aim of preventing such accidents, a phosphorus based fire retardant, a halogen based retardant or a water-containing compound such as of magnesium hydroxide has been added to vinyl chloride resin to improve its fire-retardant property. However, even in the case of moldings of vinyl chloride resin whose fire-retardant property is improved in this manner, when they are used for example in semiconductor production apparatuses, smoke and corrosive gas generated by a fire reduce the purity of air in the production facility and thereby cause a possible danger of polluting and spoiling production apparatuses, instruments and semiconductor parts.
In view of such situations, fire-retardant property and the ability to inhibit generation of smoke and corrosive gas at the time of fire have recently been demanded even for the vinyl chloride resin said to have fire-retardant property in general, and since such a demand is particularly strong in the field of insurance organizations, the evaluation criteria provided by Factory Mutual Research Corporation that constitutes Factory Mutual System, an industrial mutual insurance organization having a base of operations in North America, are effectively used.
According to this evaluation criteria, a fire propagation index FPI of 6 or less which shows fire-retardant property, a smoke damage index SDI of 0.4 or less which shows smoking ability and a corrosion damage index CDI of 1.1 or less which shows corrosive gas generation are required at the same time, based on a fire-retardant property test of clean room materials (FMRC Clean Room Materials Flammability Test, to be referred to as “FM standard” hereinafter) cited as Class Number 4910.
Regarding these requirements, a fire propagation index FPI of 6 or less of vinyl chloride resin moldings can be achieved relatively easily by the addition of a fire retardant additive, but it is not easy to obtain a vinyl chloride resin molding which also satisfies the smoke damage index SDI and corrosion damage index CDI at the same time, and only extremely few moldings such as the fire-retardant vinyl chloride resin moldings disclosed by the present inventors in Japanese Patent Application No. 9-365319 can satisfy the FPI, SDI and CDI standards at the same time. Such moldings, however, have disadvantages of being not so good in strength, chemical resistance and corrosion resistance.
SUMMARY OF THE INVENTION
The present invention has been made taking the aforementioned problems into consideration, with the aim of providing a fire-retardant vinyl chloride resin molding of more desirable blending composition, which satisfies all criteria of FPI, SDI and CDI and has practical strength, chemical resistance and corrosion resistance.
As a result of intensive studies, the inventors of the present invention have found an entirely unexpected fact that titanium oxide which is conventionally formulated in a small amount as an ingredient such as a pigment can achieve the just described object by effectively acting as a fire retardant when it is contained in a vinyl chloride resin at a specified ratio. This invention has been accomplished on the basis of this finding.
According to a first embodiment of the present invention, there is provided a fire-retardant vinyl chloride resin molding which comprises from 5 to 50 parts by weight of titanium oxide and 100 parts by weight of a vinyl chloride resin.
According to a second embodiment of the present invention, there is provided a fire-retardant vinyl chloride resin molding which comprises from 5 to 50 parts by weight of titanium oxide, 100 parts by weight of a vinyl chloride resin and at least one compounding agent selected from the group consisting of a chlorine capturing compound, an inorganic auxiliary and a fire retarding auxiliary in such an amount that the total content of titanium oxide and the compounding agent is 60 parts by weight or less based on 100 parts by weight of the vinyl chloride resin.
According to a third embodiment of the present invention, there is provided a fire-retardant vinyl chloride resin molding which comprises a base layer and a surface layer provided on at least one side of the base layer, wherein:
said base layer comprises from 5 to 50 parts by weight of titanium oxide and 100 parts by weight of a vinyl chloride resin;
said surface layer comprises from 0 to 30 parts by weight of titanium oxide and 100 parts by weight of the vinyl chloride resin;
and the titanium oxide content of the surface layer is smaller than the titanium oxide content of the base layer.
According to a fourth embodiment of the present invention, there is provided a fire-retardant vinyl chloride resin molding which comprises a base layer and a surface layer provided on at least one side of the base layer, wherein:
said base layer comprises from 5 to 50 parts by weight of titanium oxide, 100 parts by weight of a vinyl chloride resin, and at least one compounding agent selected from the group consisting of a chlorine capturing compound, an inorganic auxiliary and a fire retarding auxiliary in such an amount that the total content of titanium oxide and the compounding agent in the base layer is 60 parts by weight or less based on 100 parts by weight of the vinyl chloride resin;
said surface layer comprises from 0 to 30 parts by weight of titanium oxide and 100 parts by weight of the vinyl chloride resin; and
the titanium oxide content of the surface layer is smaller than the titanium oxide content of the base layer.
According to a fifth embodiment of the present invention, there is provided a fire-retardant vinyl chloride resin molding which comprises a base layer and a surface layer provided on at least one side of the base layer, wherein:
said base layer comprises from 5 to 50 parts by weight of titanium oxide and 100 parts by weight of a vinyl chloride resin;
said surface layer comprises from 0 to 30 parts by weight of titanium oxide, 100 parts by weight of the vinyl chloride resin, and at least one compounding agent selected from the group consisting of a chlorine capturing compound, an inorganic auxiliary and a fire retarding auxiliary in such an amount that the total content of titanium oxide and the compounding agent in the surface layer is 40 parts by weight or less based on 100 parts by weight of the vinyl chloride resin;
the titanium oxide content of the surface layer is smaller than the titanium oxide content of the base layer.
According to a sixth embodiment of the present invention, there is provided a fire-retardant vinyl chloride resin molding which comprises a base layer and a surface layer provided on at least one side of the base layer, wherein:
said base layer comprises from 5 to 50 parts by weight of titanium oxide, 100 parts by weight of a vinyl chloride resin, and at least one compounding agent selected from the group consisting of a chlorine capturing compound, an inorganic auxiliary and a fire retarding auxiliary in such an amount that th
Oritani Kazuhiro
Watanabe Kenji
Suhgrue, Mion, Zinn, Macpeak & Seas, PLLC
Takiron Co., Ltd.
Tarazano D. Lawrence
Thibodeau Paul
LandOfFree
Fire-retardant vinyl chloride resin molding does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fire-retardant vinyl chloride resin molding, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fire-retardant vinyl chloride resin molding will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2611799