CA1300777C - Zinc borate as a smoke suppressant - Google Patents
Zinc borate as a smoke suppressantInfo
- Publication number
- CA1300777C CA1300777C CA000542374A CA542374A CA1300777C CA 1300777 C CA1300777 C CA 1300777C CA 000542374 A CA000542374 A CA 000542374A CA 542374 A CA542374 A CA 542374A CA 1300777 C CA1300777 C CA 1300777C
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- polysiloxane
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
- H01B7/29—Protection against damage caused by extremes of temperature or by flame
- H01B7/295—Protection against damage caused by extremes of temperature or by flame using material resistant to flame
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/38—Boron-containing compounds
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- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
ZINC BORATE AS A SMOKE SUPPRESSANT
ABSTRACT OF THE DISCLOSURE
A high hydrocarbon content combustible composition containing silicone is described which incorporates zinc borate to reduce smoke emission. The composition comprises:
(a) sufficient hydrocarbon content that elemental carbon constitutes at least about 40% by weight of the total composition;
(b) sufficient silicone polymer that elemental silicon constitutes at least about 1/2 % by weight of the total composition; and (c) sufficient zinc borate to reduce smoke generation.
ABSTRACT OF THE DISCLOSURE
A high hydrocarbon content combustible composition containing silicone is described which incorporates zinc borate to reduce smoke emission. The composition comprises:
(a) sufficient hydrocarbon content that elemental carbon constitutes at least about 40% by weight of the total composition;
(b) sufficient silicone polymer that elemental silicon constitutes at least about 1/2 % by weight of the total composition; and (c) sufficient zinc borate to reduce smoke generation.
Description
`- 13~'777 ~i O S I 10 8 3 ZINC Bb~ATE AS A SMOKE SUPPRESSANT
Background of the Invention This invention relates to zinc borate as a smoke suppressant. More particularly, this invention relates to zinc borate as a smoke suppressant in high hydrocarbon content combustible silicone containing compositions.
The use of metal borates including zinc bDrate as smoke suppressants for PVC and other polyolefin materials has been reported in a number of publications and patents. Zinc borate is known to work well as a smoke suppressant when used either alone or jn combination with antimony oxide for polymer compositions containing halogen, but is generally ineffective for non-halogen containing materials.
U.S. Patent No. 4,182,799 discloses flame retardant additives for polystyrene foam. These additives comprise 40-56% by weight halogenated hydrocarbon, 14-22% by weight ~inc borate, and 16-23% by weight Al(OH)3.
Cowan, J.; Manley, T.R.; Br. Polym. J. 1976, 8(2), 44-7 disclose flame retardants and smoke suppressants for flexible PVC film. Ba and Ca borates with or without Sb203 had little or no flame retardency, but Zn borate had a synergistic effect with Sb203. Zn borate and Sb203 were also found to be the most effective smoke suppressants.
. . - : ,. .
, "' . . ' ' ' : . ' .- ' ' ,' ,`
, , : . , , 60SI-lm ~ -Shen, Kelvin K., Sprague, Robert W.; J. Vinyl Technology 1982, 4(3), 120-3 disclose flame retardants and smoke suppressants for PVC. Zinc borate alone was found to be an effective flame retardant. Zinc borate in synergism with Al(OH)3 was found to be an effective smoke suppressant.
Shen, Kelvin K.; Sprague, Robert W.; J. Fire Retardant Chemistry 1982, 9(3), 1~1-71 discloses flame retardants for epoxy resins. Zinc borate alone was found to be an ineffective ftame retardant or smoke suppressant for epoxy resins in the absence of a halogen source.
It is the object of the present invention to utilize zinc ; borate as a flame retardant and smoke suppressant for certain s~lane containing compositions.
~ It is another object of the present invention to utili~e zinc borate as a flame retardant and smoke suppressant for silicone containing compositions having high hydrocarbon content, particularly where the hydrocarbon content is in the form of aromatic rings.
Detailed Description of the Invention ~riefly, according to the present invention, there are provided high hydrocarbon content combustible silicone containing compositions exhibiting reduced smoke generation which co~prise:
(a) sufficient hydrocarbon content that elemental carbon constitutes at least about 40% by weight the total composition;
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~ ~3Q~1~7~7 PATENTS
60SI-1083/JWH:mz (b) sufficient silicone polymer or copolymer that elemental silicon constitutes at least about l/2% by weight the total composition; and (c) sufficient zinc borate to reduce smoke generation~
Combustible silicone containing compositions, which are the subject of the present invention, have relatively high hydrocarbon contents such that these silicone containing compositions will in the absence of flame retardants either freely support combustion or will flame under applied heat.
The hydrocarbon content of these silicone containing compositions may exist in various forms. It may be an alkylene group, alkyl group, aryl group, etc., on a silicone polymer or copolymer. ~t may be a carbonate moiety, imide moiety, urethane moiety, etc., in a silicone copoly~er or block copolymer. It may be a polyolefin, polycarbonate, polyester, poly(phenylene-ether), etc., which has been blended with a silicone polymer or copolymer. Regardless of how the hydrocarbon is contained within the silicone containing composition, it should be considered as such and as contributing to combustibility. Generally, for a silicone containing composition to have a relatively high hydrocarbon content as mentioned above, it must contain, on an elemental level, at least about 40% by weight carbon, and more preferably at least about 50% by weight carbon. Silicone containing compositions having 60% carbon by weight will particularly benefit from the present invention.
Applicants believe the present invention to be most beneficial in the instance where the hydrocarbon content is ', l ,. . . . ...... , . . .. . . . .. . . ., .. ., . . . .. .. . . . ,, . . . . .. , .. . ... .. . ~ . ..
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substantially in the form of aromatic rings. Thus, at least 40~ and preferably 50X by weight of the elemental carbon is contained in aromatic rings, it is believed that maximum benefit can be derived herefrom.
The hydrocarbon content of these silicone containing compositions may or may not have present therein organic halogens. Organic halogens are commonly used as flame retardants and include decabromodiphenyl ether, tribromopolystyrene and the like~
In order for the composition to be considered silicone containing, it must contain sufficient silicone resin that the relatively low level of hydrocarbon smoke generation is significantly increased. Such increase should not require the ; presence of very large amounts of silicone. It is considered herein that silicone polymer or copolymer in sufficient amounts that silicon constitutes greater than about l/2% by weight of the total composition will significankly increase smoke generation. Silicon present at greater than 2% by weight should increase smoke generation and silicon present at greater than lO~ by weight is known to produce about an 8 fold increase in smoke generation by some standards.
Silicone polymer or copolymer contain recurring units of the formula a (4-a)/2 2~ wherein a can vary from greater than zero to less than three, and R can be alkyl, aryl, alkenyl, halogenated alkyl, halogenated aryl, and the like. Preferably~ a is 2 and R is methyl, phenyl, or vinyl. Of course, the silicone polymer or copolymer may be substituted with hydride, hydroxy, alkoxy~ etc.
., : :~
~3Q~777 PATEN~S
60SI-1083/JWH:mz Silicone containing compositions which ~re the subject of the present invention include specifically 1) high hydrocarbon content silicone polymers and copolymers; 2) blends of silicone polymers; 3) cocondensates of silicone polymers and copolymers with organic polymer; and 4) blends of the above. Of course, other silicone containing compositions may be imagined including silicone plasticizers used in organic plastics, etc.
High hydrocarbon content silicone polymers and copolymers as mentioned above generally have substituted or unsubstituted higher aliphatic or aromatic organic groups on the silicone polymer. These groups may be alkoxy groups, vinyl groups, epoxy groups, acrylic groups, allyl groups, phenyl groups, etc. The silicone polymer itself may be linear, branched, or cross-linked. Generally, these polymers and copolymers have not been technically important due to poor heat stability.
However, such polymers and copolymers which contain a relatively high number of phenyl groups are known and utilized. As to these specific polymers, reference is made to Unit~d States Patent Numbers 3,328,346; 2,868,766,..~
and 2,611,77A. Also, there a~e sllicone copolymers -in which an arylene group is contained in the polymer chain.
As to these silarylene siloxane copolymers, reference is made to U.S. Patent No. 4,340,711 .
Blends of silicone polymers and copolymers with organic polymers include both blends where the silicone polymer or copolymer forms the major constituent and blends where the organic polymer forms the major constitutent. It is not possible to make any general statements about the organic polymers that are at least to some extent compatible with .,, . . ., ., . , . .. , . , . . , . .. , . ~ ., .. . , . ., . . ., .. . j . . ....... . . . . . .... . . . ...
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60SI-1083/JWH:mz silicone polymers and copolymers. Polymers most likely to be compatible are polymethacrylates, urea-forrnaldehyde resins, melamine-formaldehyde resins, chlorinated di- and terphenyls, polyesters, and alkyd resins. However, the compatibility of these organic polymers with silicone polymers cannot always be determined beforehand. Silicone polymers which have been modified with organic constituents often make compatibility more certain.
Co-condensates of silicone polymers and copolymers with organic polymers are generally intended to combine the good properties of the polysilnxanes with those of the organic polymers. The cocondensates may be silicone polymers having structural carbon units in the backbone, such as polyalkyleneoxysiloxanes; block copolymers having blocks of lS siloxane and organic polymers; or grafted or crosslinked networks of silicone polymers and organic polymers. Copolymers of silicones and aldehydes may be made by the reaction of formaldehyde hydrate with dimethyldichlorosilane. Copolymers of silicone and polyalcohols or polyphencls may be made by reacting, for example, a halide, hydride, or alkoxy substituted silicone or silane with, for example, a glycerol~ 4,4'-di-hydroxybenzophenone, 4,4'-dihydroxydiphenylpropane, or 4,4'-dihydroxydiphenyl methane. Copolymers oF silicone with polyether can be produced having Si-0-C bridges where hydroxyl containing polyether is caused to react with silanes and siloxanes containing Si-0-C2H5, Si-H, or Si-N groupings.
Analagous copolymers of silicone with polyether can be produced having Si-C bridges where polyethers containing alkenyl groups are addition reacted with silanes or siloxanes containing Si-H
groups. Copolymers of silicone with polyester can be produced :` ~' , , . ' .`:
~.
3VC3~
where the linkage is through an Si-O-C bridge by reacting hydroxyl containing polyesters with halide, hydride, hydroxy or alkoxy substituted silicone or silane. Copolymers of silicone with polyester can be produced where the linkage is through an Si-C bridge by reacting a carboxy organosilane or carboxyorganosiloxane with hydroxyl containing polyester. Copolymers of silicone with polyolefin may be produced by polymeriæing, for example, ethylene or propylene in the presence of a vinyl or allyl containing siloxane or silane. Siloxane-carbonate copolymers are described in U.S. Patent No. 3,189,662 and 3,821,325. Other silicone containing polymers include siloxane-urethane copolymers, siloxane-epoxy-hydroxy copolymers, siloxane-phenol-formaldehyde, etc.
Of particular interest herein are copolymers of siloxane with polyimide or polyetherimide. These polymers have siloxane-imide blocks having units of the formula:
O O
2() --_1 11~ ~ r\;/ X I ) X~
O O
where R is a hydrocarbylene radical, Rl is a substituted or unsubstituted monovalent hydrocarbon radical, Ar1 can be a tetravalent benzene or naphthalene nucleus or a tetravalent group of the formula 2 5 a ~E~
PA~ENTS
60SI-10~/J~H:mz where m is 0 or 1 and E is --D--.--S--,--S--.--S--.--C--(Q`1~2 ~ H~
where y is an integer from 1 to 8.
In a more preferred embodiment Ar of formula I includes diether linkages so as to increase the solubility of the final product in diglyme. Thus, in the more preferred embodiment, Arl formula I ~s a tetravalent residue of the formula ~}0--G--0~
where G is phenylene or a group of the formula ~(E)~
where E and m are as previously defined.
Especially preferred is an Arl group jn formula I having the formula ~ .
~~'~~_ ' , ' . ' ' . ~; ~ ' ' ' 3~ 7 PA~E NTS
60SI -~7J~H:mz g A more complete listing ~f suitable Arl radicals can be found in U.S. Pat. No. 4~395,527.
R in formula I can be any substituted or unsubstituted hydrocarbylene radical, for example, a linear or branched alkylene radical haviny up to about 20 carbon atoms such as methylene, ethylene, propylene, isopropylene, isobutylene; an alkylene radical having up to about 20 carbon atoms which is interrupted in the chain by one or more phenylene radicals; or a radical of the formula -Q-Z-R3-, where Q is any substituted or unsubstituted aromatic hydrocarbylene radical such as phenylene or naphthalene, or a heterocyclic aromatic radical where the hereto atom is selected from N, 0 and S; Z is -0-, -S-, O O OH HO ~10 IOl H ~1 --5--,--5--,--S N--.--N~ NC--,--CN--,--C--O--, O O O
or :: o --o--c--;
~ and R3 is a hydrocarbylene radical within the scope of R.
. Preferably R is a lower alkylene radical and most preferably is propylene. These and other suitable R groups are known in the art and are described more fully in U.S. Pat. Nos. 3,3253450 and 4,395,527.
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PATENTS
60SI-l083/JWH:mz Rl radicals in formula I can be any independently selected monovalent substituted or unsubstituted radicals typically bonded to silicon atoms of a polysiloxane. Among the more preferred R radicals are lower alkyl radicals such as methyl, ethylg propyl or butyl radicals, phenyl radicals, vinyl radicals, 3,3,3-trifluoropropyl radicals and the like.
Depending upon the desired properties of the final product, the artisan can select suitable Rl radicals, as well as all the other radicals, in proper ratios without undue experimentation.
In addition to blocks of formula l above, there may also be present blocks haviny the formula R
\~ \c/ I I .
o o where Arl jS as defined in formula I and R2 is a divalent organic radical. Preferred R2 include ethylene, trimethyl-ene, isopropylidene, [-(CH3)C(CH3)-], isobutylene, tetra-methylene, pentamethylene, phenylene, substituted phenylene, toluene, xylene, biphenylene (~) diphenylene methane (-C6H4-CH2-C6H4-), diphenylene oxide (~~) -.
`` ~3~ 7`
PATENTS
60SI^10~3/JWH:mz diphenylene sulfone, etcr, with valences of the arylene radicals being ortho, meta, or para to each other or to connecting bonds between adjacent arylene radicals.
The preparation of polyimides and, more particularly, silicone-imide copolymers, is well known in the art, for example, as taught in United States Patent Numbers 3,325,450 and 4,395,527. Generally polyimides are prepared by reacting a dianhydride with a diamine, the diamine in this case being an organic diamine and a siloxane diamine. Relative reactivities of the monomers must be considered in a reaction scheme to obtain a truly random block where such is desired.
Zinc borate suitable for use herein has a typical formulation ZnO 45%, B203 34%, and may have 20~ water of hydration. It is produced by the interaction of oxides at 500 - 1000C or by the interaction of zinc oxide slurries with solutions of boric acid or borax. The particular ~inc borate used herein has the formula 2 7.nO 3B203 3.5 H20, a refractive index of 1.58 and a mean particle size in the range of 2-10 microns. This zinc borate is sold under the registered trademark FlREBRAKE ZB and is manufactured in accordance with the teachings of United States Patcnt Numher.
3,549,316.`
Persons skilled in the art can easily determine what amount of zinc borate is necessary to reduce smoke generation It has been found herein that where 5X by weight oF the silicone containing composition is zinc borate, smoke generation is greatly reduced. Where the compositi?n is 10~ by weight, smoke ,, , , ,, ,, ,, ., ~. , . .. ., .. . . ! . ' ~ . ' . . .
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60SI-lO837J~H:mz generation is likewise reduced but without a great reduction over the 5% by weight level. Thus, it is recommended herein that the zinc borate should be added to the silicone containing composition in amounts ranging from about lX to about 15X by weight and most advantageously in amounts ranging from about 2%
to about lO% by weight.
The ~inc borate is dispersed in the silicone containing composition as appropriate. For thermoplastic materials, the zinc borate is added in a melt blending process. For a thermoset, zinc borate must be added prior to crosslinking.
In order to better enable the artisan to practice the present invention, the following examples are provided by way of illustration and not by way of limitation. All parts are by weight unless otherwise noted.
EXAMPLES
Example l -Bis (gan~la-aminopropyl) tetramethyldisiloxane was produced according to U.S. Pat. No. 4,584,393 and equilibrated for varying times with octamethylcyclotetrasiloxane to produce bis (gamma-aminopropyl) polydimethylsiloxane (GAPD) having varying siloxane chain lengths. Equilibration was carried out at about 150C in the presence of KOH.
Examples 2 - 12 ___ GAPD of Example l having a silicone chain length as shown in Table l, was reacted with bisphenol-A-dianhydride (BPADA) '' .' ' ~ -: ` ., `` 13~7'7'7 PA~ENTs ~OS~ 83/~WH:mz and metaphenylenediamine (MPD) to produce a poly (siloxane-ether-imide~. The amount of GAPD present in the copolymer varied as shown in Table 1, i.e. the GAPD constituted varying amounts on a mole basis of the total diamine content of the copolymer. The copolymer was molded into 3" x 3" x 1/8"
; test plaques for the NBS Smoke Test and into 5" x 1~2" x 1/8"
i test bars for the UL-94 flame test.
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Background of the Invention This invention relates to zinc borate as a smoke suppressant. More particularly, this invention relates to zinc borate as a smoke suppressant in high hydrocarbon content combustible silicone containing compositions.
The use of metal borates including zinc bDrate as smoke suppressants for PVC and other polyolefin materials has been reported in a number of publications and patents. Zinc borate is known to work well as a smoke suppressant when used either alone or jn combination with antimony oxide for polymer compositions containing halogen, but is generally ineffective for non-halogen containing materials.
U.S. Patent No. 4,182,799 discloses flame retardant additives for polystyrene foam. These additives comprise 40-56% by weight halogenated hydrocarbon, 14-22% by weight ~inc borate, and 16-23% by weight Al(OH)3.
Cowan, J.; Manley, T.R.; Br. Polym. J. 1976, 8(2), 44-7 disclose flame retardants and smoke suppressants for flexible PVC film. Ba and Ca borates with or without Sb203 had little or no flame retardency, but Zn borate had a synergistic effect with Sb203. Zn borate and Sb203 were also found to be the most effective smoke suppressants.
. . - : ,. .
, "' . . ' ' ' : . ' .- ' ' ,' ,`
, , : . , , 60SI-lm ~ -Shen, Kelvin K., Sprague, Robert W.; J. Vinyl Technology 1982, 4(3), 120-3 disclose flame retardants and smoke suppressants for PVC. Zinc borate alone was found to be an effective flame retardant. Zinc borate in synergism with Al(OH)3 was found to be an effective smoke suppressant.
Shen, Kelvin K.; Sprague, Robert W.; J. Fire Retardant Chemistry 1982, 9(3), 1~1-71 discloses flame retardants for epoxy resins. Zinc borate alone was found to be an ineffective ftame retardant or smoke suppressant for epoxy resins in the absence of a halogen source.
It is the object of the present invention to utilize zinc ; borate as a flame retardant and smoke suppressant for certain s~lane containing compositions.
~ It is another object of the present invention to utili~e zinc borate as a flame retardant and smoke suppressant for silicone containing compositions having high hydrocarbon content, particularly where the hydrocarbon content is in the form of aromatic rings.
Detailed Description of the Invention ~riefly, according to the present invention, there are provided high hydrocarbon content combustible silicone containing compositions exhibiting reduced smoke generation which co~prise:
(a) sufficient hydrocarbon content that elemental carbon constitutes at least about 40% by weight the total composition;
`.
.
.: . - . .
~ ~3Q~1~7~7 PATENTS
60SI-1083/JWH:mz (b) sufficient silicone polymer or copolymer that elemental silicon constitutes at least about l/2% by weight the total composition; and (c) sufficient zinc borate to reduce smoke generation~
Combustible silicone containing compositions, which are the subject of the present invention, have relatively high hydrocarbon contents such that these silicone containing compositions will in the absence of flame retardants either freely support combustion or will flame under applied heat.
The hydrocarbon content of these silicone containing compositions may exist in various forms. It may be an alkylene group, alkyl group, aryl group, etc., on a silicone polymer or copolymer. ~t may be a carbonate moiety, imide moiety, urethane moiety, etc., in a silicone copoly~er or block copolymer. It may be a polyolefin, polycarbonate, polyester, poly(phenylene-ether), etc., which has been blended with a silicone polymer or copolymer. Regardless of how the hydrocarbon is contained within the silicone containing composition, it should be considered as such and as contributing to combustibility. Generally, for a silicone containing composition to have a relatively high hydrocarbon content as mentioned above, it must contain, on an elemental level, at least about 40% by weight carbon, and more preferably at least about 50% by weight carbon. Silicone containing compositions having 60% carbon by weight will particularly benefit from the present invention.
Applicants believe the present invention to be most beneficial in the instance where the hydrocarbon content is ', l ,. . . . ...... , . . .. . . . .. . . ., .. ., . . . .. .. . . . ,, . . . . .. , .. . ... .. . ~ . ..
,~ - . .. . . ~ .
;~ :IL3~)~777' PATENTS
60SI-1083/JWH:mz .~
substantially in the form of aromatic rings. Thus, at least 40~ and preferably 50X by weight of the elemental carbon is contained in aromatic rings, it is believed that maximum benefit can be derived herefrom.
The hydrocarbon content of these silicone containing compositions may or may not have present therein organic halogens. Organic halogens are commonly used as flame retardants and include decabromodiphenyl ether, tribromopolystyrene and the like~
In order for the composition to be considered silicone containing, it must contain sufficient silicone resin that the relatively low level of hydrocarbon smoke generation is significantly increased. Such increase should not require the ; presence of very large amounts of silicone. It is considered herein that silicone polymer or copolymer in sufficient amounts that silicon constitutes greater than about l/2% by weight of the total composition will significankly increase smoke generation. Silicon present at greater than 2% by weight should increase smoke generation and silicon present at greater than lO~ by weight is known to produce about an 8 fold increase in smoke generation by some standards.
Silicone polymer or copolymer contain recurring units of the formula a (4-a)/2 2~ wherein a can vary from greater than zero to less than three, and R can be alkyl, aryl, alkenyl, halogenated alkyl, halogenated aryl, and the like. Preferably~ a is 2 and R is methyl, phenyl, or vinyl. Of course, the silicone polymer or copolymer may be substituted with hydride, hydroxy, alkoxy~ etc.
., : :~
~3Q~777 PATEN~S
60SI-1083/JWH:mz Silicone containing compositions which ~re the subject of the present invention include specifically 1) high hydrocarbon content silicone polymers and copolymers; 2) blends of silicone polymers; 3) cocondensates of silicone polymers and copolymers with organic polymer; and 4) blends of the above. Of course, other silicone containing compositions may be imagined including silicone plasticizers used in organic plastics, etc.
High hydrocarbon content silicone polymers and copolymers as mentioned above generally have substituted or unsubstituted higher aliphatic or aromatic organic groups on the silicone polymer. These groups may be alkoxy groups, vinyl groups, epoxy groups, acrylic groups, allyl groups, phenyl groups, etc. The silicone polymer itself may be linear, branched, or cross-linked. Generally, these polymers and copolymers have not been technically important due to poor heat stability.
However, such polymers and copolymers which contain a relatively high number of phenyl groups are known and utilized. As to these specific polymers, reference is made to Unit~d States Patent Numbers 3,328,346; 2,868,766,..~
and 2,611,77A. Also, there a~e sllicone copolymers -in which an arylene group is contained in the polymer chain.
As to these silarylene siloxane copolymers, reference is made to U.S. Patent No. 4,340,711 .
Blends of silicone polymers and copolymers with organic polymers include both blends where the silicone polymer or copolymer forms the major constituent and blends where the organic polymer forms the major constitutent. It is not possible to make any general statements about the organic polymers that are at least to some extent compatible with .,, . . ., ., . , . .. , . , . . , . .. , . ~ ., .. . , . ., . . ., .. . j . . ....... . . . . . .... . . . ...
.
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~3i[~07~
PATENTS
60SI-1083/JWH:mz silicone polymers and copolymers. Polymers most likely to be compatible are polymethacrylates, urea-forrnaldehyde resins, melamine-formaldehyde resins, chlorinated di- and terphenyls, polyesters, and alkyd resins. However, the compatibility of these organic polymers with silicone polymers cannot always be determined beforehand. Silicone polymers which have been modified with organic constituents often make compatibility more certain.
Co-condensates of silicone polymers and copolymers with organic polymers are generally intended to combine the good properties of the polysilnxanes with those of the organic polymers. The cocondensates may be silicone polymers having structural carbon units in the backbone, such as polyalkyleneoxysiloxanes; block copolymers having blocks of lS siloxane and organic polymers; or grafted or crosslinked networks of silicone polymers and organic polymers. Copolymers of silicones and aldehydes may be made by the reaction of formaldehyde hydrate with dimethyldichlorosilane. Copolymers of silicone and polyalcohols or polyphencls may be made by reacting, for example, a halide, hydride, or alkoxy substituted silicone or silane with, for example, a glycerol~ 4,4'-di-hydroxybenzophenone, 4,4'-dihydroxydiphenylpropane, or 4,4'-dihydroxydiphenyl methane. Copolymers oF silicone with polyether can be produced having Si-0-C bridges where hydroxyl containing polyether is caused to react with silanes and siloxanes containing Si-0-C2H5, Si-H, or Si-N groupings.
Analagous copolymers of silicone with polyether can be produced having Si-C bridges where polyethers containing alkenyl groups are addition reacted with silanes or siloxanes containing Si-H
groups. Copolymers of silicone with polyester can be produced :` ~' , , . ' .`:
~.
3VC3~
where the linkage is through an Si-O-C bridge by reacting hydroxyl containing polyesters with halide, hydride, hydroxy or alkoxy substituted silicone or silane. Copolymers of silicone with polyester can be produced where the linkage is through an Si-C bridge by reacting a carboxy organosilane or carboxyorganosiloxane with hydroxyl containing polyester. Copolymers of silicone with polyolefin may be produced by polymeriæing, for example, ethylene or propylene in the presence of a vinyl or allyl containing siloxane or silane. Siloxane-carbonate copolymers are described in U.S. Patent No. 3,189,662 and 3,821,325. Other silicone containing polymers include siloxane-urethane copolymers, siloxane-epoxy-hydroxy copolymers, siloxane-phenol-formaldehyde, etc.
Of particular interest herein are copolymers of siloxane with polyimide or polyetherimide. These polymers have siloxane-imide blocks having units of the formula:
O O
2() --_1 11~ ~ r\;/ X I ) X~
O O
where R is a hydrocarbylene radical, Rl is a substituted or unsubstituted monovalent hydrocarbon radical, Ar1 can be a tetravalent benzene or naphthalene nucleus or a tetravalent group of the formula 2 5 a ~E~
PA~ENTS
60SI-10~/J~H:mz where m is 0 or 1 and E is --D--.--S--,--S--.--S--.--C--(Q`1~2 ~ H~
where y is an integer from 1 to 8.
In a more preferred embodiment Ar of formula I includes diether linkages so as to increase the solubility of the final product in diglyme. Thus, in the more preferred embodiment, Arl formula I ~s a tetravalent residue of the formula ~}0--G--0~
where G is phenylene or a group of the formula ~(E)~
where E and m are as previously defined.
Especially preferred is an Arl group jn formula I having the formula ~ .
~~'~~_ ' , ' . ' ' . ~; ~ ' ' ' 3~ 7 PA~E NTS
60SI -~7J~H:mz g A more complete listing ~f suitable Arl radicals can be found in U.S. Pat. No. 4~395,527.
R in formula I can be any substituted or unsubstituted hydrocarbylene radical, for example, a linear or branched alkylene radical haviny up to about 20 carbon atoms such as methylene, ethylene, propylene, isopropylene, isobutylene; an alkylene radical having up to about 20 carbon atoms which is interrupted in the chain by one or more phenylene radicals; or a radical of the formula -Q-Z-R3-, where Q is any substituted or unsubstituted aromatic hydrocarbylene radical such as phenylene or naphthalene, or a heterocyclic aromatic radical where the hereto atom is selected from N, 0 and S; Z is -0-, -S-, O O OH HO ~10 IOl H ~1 --5--,--5--,--S N--.--N~ NC--,--CN--,--C--O--, O O O
or :: o --o--c--;
~ and R3 is a hydrocarbylene radical within the scope of R.
. Preferably R is a lower alkylene radical and most preferably is propylene. These and other suitable R groups are known in the art and are described more fully in U.S. Pat. Nos. 3,3253450 and 4,395,527.
;
. . . . ...................... . . . .
. - ,. ~
. ~.. . . . .
~ . . ~ , . , A
13~ 7'o~
PATENTS
60SI-l083/JWH:mz Rl radicals in formula I can be any independently selected monovalent substituted or unsubstituted radicals typically bonded to silicon atoms of a polysiloxane. Among the more preferred R radicals are lower alkyl radicals such as methyl, ethylg propyl or butyl radicals, phenyl radicals, vinyl radicals, 3,3,3-trifluoropropyl radicals and the like.
Depending upon the desired properties of the final product, the artisan can select suitable Rl radicals, as well as all the other radicals, in proper ratios without undue experimentation.
In addition to blocks of formula l above, there may also be present blocks haviny the formula R
\~ \c/ I I .
o o where Arl jS as defined in formula I and R2 is a divalent organic radical. Preferred R2 include ethylene, trimethyl-ene, isopropylidene, [-(CH3)C(CH3)-], isobutylene, tetra-methylene, pentamethylene, phenylene, substituted phenylene, toluene, xylene, biphenylene (~) diphenylene methane (-C6H4-CH2-C6H4-), diphenylene oxide (~~) -.
`` ~3~ 7`
PATENTS
60SI^10~3/JWH:mz diphenylene sulfone, etcr, with valences of the arylene radicals being ortho, meta, or para to each other or to connecting bonds between adjacent arylene radicals.
The preparation of polyimides and, more particularly, silicone-imide copolymers, is well known in the art, for example, as taught in United States Patent Numbers 3,325,450 and 4,395,527. Generally polyimides are prepared by reacting a dianhydride with a diamine, the diamine in this case being an organic diamine and a siloxane diamine. Relative reactivities of the monomers must be considered in a reaction scheme to obtain a truly random block where such is desired.
Zinc borate suitable for use herein has a typical formulation ZnO 45%, B203 34%, and may have 20~ water of hydration. It is produced by the interaction of oxides at 500 - 1000C or by the interaction of zinc oxide slurries with solutions of boric acid or borax. The particular ~inc borate used herein has the formula 2 7.nO 3B203 3.5 H20, a refractive index of 1.58 and a mean particle size in the range of 2-10 microns. This zinc borate is sold under the registered trademark FlREBRAKE ZB and is manufactured in accordance with the teachings of United States Patcnt Numher.
3,549,316.`
Persons skilled in the art can easily determine what amount of zinc borate is necessary to reduce smoke generation It has been found herein that where 5X by weight oF the silicone containing composition is zinc borate, smoke generation is greatly reduced. Where the compositi?n is 10~ by weight, smoke ,, , , ,, ,, ,, ., ~. , . .. ., .. . . ! . ' ~ . ' . . .
. ` . ' '`', ,'' '~",' ~ . , ''` ' ~ .
~3~ 7~7 PATENTS
60SI-lO837J~H:mz generation is likewise reduced but without a great reduction over the 5% by weight level. Thus, it is recommended herein that the zinc borate should be added to the silicone containing composition in amounts ranging from about lX to about 15X by weight and most advantageously in amounts ranging from about 2%
to about lO% by weight.
The ~inc borate is dispersed in the silicone containing composition as appropriate. For thermoplastic materials, the zinc borate is added in a melt blending process. For a thermoset, zinc borate must be added prior to crosslinking.
In order to better enable the artisan to practice the present invention, the following examples are provided by way of illustration and not by way of limitation. All parts are by weight unless otherwise noted.
EXAMPLES
Example l -Bis (gan~la-aminopropyl) tetramethyldisiloxane was produced according to U.S. Pat. No. 4,584,393 and equilibrated for varying times with octamethylcyclotetrasiloxane to produce bis (gamma-aminopropyl) polydimethylsiloxane (GAPD) having varying siloxane chain lengths. Equilibration was carried out at about 150C in the presence of KOH.
Examples 2 - 12 ___ GAPD of Example l having a silicone chain length as shown in Table l, was reacted with bisphenol-A-dianhydride (BPADA) '' .' ' ~ -: ` ., `` 13~7'7'7 PA~ENTs ~OS~ 83/~WH:mz and metaphenylenediamine (MPD) to produce a poly (siloxane-ether-imide~. The amount of GAPD present in the copolymer varied as shown in Table 1, i.e. the GAPD constituted varying amounts on a mole basis of the total diamine content of the copolymer. The copolymer was molded into 3" x 3" x 1/8"
; test plaques for the NBS Smoke Test and into 5" x 1~2" x 1/8"
i test bars for the UL-94 flame test.
..
.'~
-- ~30(~77 PATE NT S
60SI -1083/JWH:mz . v.~ _ c _ c c _ O _ _ _ _ _ ' ' ' 1 - I I ' ' I I ' I
~ ~ E to ~ ~ v l ¦~ c l I o .o ~ ~ ~ ~ q I I ~D l l I r~ C~
~- n ~ n 0~ ~ ~ n ~ ~ ~ n c . L l C~l ~a I o o o ~ ~D ~ n v~ v a o ~ l ¦ to ~ to c~ c~ ¦ r~ r~
-- _ l ¦ N _~ ~ O O O r I ~ E
a o l ¦ o o o o o o v~ E
C U ~ ~ O ~ r~ r~ I~ ~ ~ ~ _ _ n r ' ~u~ o 0 ~ O o o ~r N ~ ~ O ~ E
3 v~ w ~ l n ~n vj c~ ¦ c~ u u7 m _ c~
~ `` ` .
~
.
'. ~
.
,~ ' , ' ' . ' ' ' ' ' ' :
` ~ ~
: :l : : ~
Claims (19)
1. A composition of matter exhibiting reduced smoke generation comprising:
(a) sufficient hydrocarbon content that elemental carbon constitutes at least about 40% by weight the total composition;
(b) sufficient silicone polymer or silicone copolymer that elemental silicon constitutes at least about 1/2% by weight the total composition; and (c) sufficient zinc borate to reduce smoke generation.
(a) sufficient hydrocarbon content that elemental carbon constitutes at least about 40% by weight the total composition;
(b) sufficient silicone polymer or silicone copolymer that elemental silicon constitutes at least about 1/2% by weight the total composition; and (c) sufficient zinc borate to reduce smoke generation.
2. The composition of claim 1 wherein said elemental carbon constitutes at least about 50% by weight eight of the total composition.
3. The composition of claim 1 wherein said elemental carbon constitutes at least about 60% by weight of the total composition.
4. The composition of claim 1 wherein said elemental silicon constitutes at least about 2% by weight of the total composition.
5. The composition of claim 1 wherein said elemental silicon constitutes at least about 10% by weight of the total composition.
6. The composition of claim 1 wherein at least about 40% by weight of the elemental carbon is contained in aromatic rings.
7. The composition of claim 1 wherein at least about 50% by weight of the elemental carbon is contained in aromatic rings.
8. The composition of claim 1 which contains no organic halogen.
9. The composition of claim 1 wherein the silicone polymer comprises recurring units of the formula RaSiO(4-a)/2 wherein a can vary from greater than 0 to less than 3, and R is selected from the group consisting of alkyl, aryl, alkenyl, halogenated alkyl, and halogenated aryl.
10. The composition of claim 9 wherein a is 2 and R is selected fro the group consisting of methyl, phenyl, and vinyl.
11. The composition of claim 1 in which the high hydrocarbon content silicone polymer is selected from the group consisting of high phenyl content silicone homopolymers or copolymers and silarylene siloxane copolymers.
12. The composition of claim 1 which comprises cocondensates of silicone homopolymers and copolymers with organic polymers.
13. The composition of claim 12, wherein said cocondensates are selected from the group consisting of copolymers of polysiloxane and aldehydes, copolymers of polysiloxane and polyalcohols or polyphenols, copolymers of polysiloxane and polyether, copolymers of polysiloxane and polyester, copolymers of polysiloxane and polyolefin and polysiloxane carbonate copolymers.
14. The composition of claim 12 wherein said cocondensate is a copolymer of polysiloxane with polyimide or polyetherimide.
15. The composition of claim 14 wherein said copolymer of polysiloxane with polyimide or polyether-imide comprises siloxane-imide blocks of the formula:
where R is a hydrocarbylene radical, R1 is a substituted or unsubstituted monovalent hydrocarbon radical, Ar1can be a tetravalent benzene or naphthalene nucleus or a tetravalent group of the formula where m is 0 or 1, n is at least 1 and E is -O- , -S- , -?- , -?-, -?-(CH3)2-, OR -CyH2y-, where y is an integer from 1 to 8.
where R is a hydrocarbylene radical, R1 is a substituted or unsubstituted monovalent hydrocarbon radical, Ar1can be a tetravalent benzene or naphthalene nucleus or a tetravalent group of the formula where m is 0 or 1, n is at least 1 and E is -O- , -S- , -?- , -?-, -?-(CH3)2-, OR -CyH2y-, where y is an integer from 1 to 8.
16. The composition of claim 15 wherein said Ar1 is a tetravalent residue of the formula where G is phenylene or a group of the formula where E and m are previously defined.
17. The composition of claim 15 wherein said Ar1 is
18. The composition of claim 15 wherein n varies on average from about 1 to about 1 to about 50.
19. The composition of claim 15 wherein R
is methylene, ethylene, or propylene.
is methylene, ethylene, or propylene.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US89145986A | 1986-07-28 | 1986-07-28 | |
| US891,459 | 1986-07-28 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1300777C true CA1300777C (en) | 1992-05-12 |
Family
ID=25398228
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000542374A Expired - Fee Related CA1300777C (en) | 1986-07-28 | 1987-07-17 | Zinc borate as a smoke suppressant |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS6341565A (en) |
| CA (1) | CA1300777C (en) |
| DE (1) | DE3720769A1 (en) |
| FR (1) | FR2601958B1 (en) |
| GB (1) | GB2193216B (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4981894A (en) * | 1989-07-27 | 1991-01-01 | General Electric Company | Halogen-free melt processable silicon-imide wire coating compositions having low smoke values |
| EP0476106B1 (en) * | 1990-04-04 | 1997-07-09 | Amoco Corporation | Poly(biphenyl ether sulfone) compositions |
| US5074640A (en) * | 1990-12-14 | 1991-12-24 | At&T Bell Laboratories | Cables which include non-halogenated plastic materials |
| EP0526162A1 (en) * | 1991-08-02 | 1993-02-03 | General Electric Company | Flame retardants for siloxane polyetherimide copolymers |
| IT1255027B (en) * | 1992-05-08 | 1995-10-13 | Luca Castellani | CABLE FOR HIGH OPERATING TEMPERATURES |
| GB9223636D0 (en) * | 1992-11-11 | 1992-12-23 | Vispak Ltd | Sealants |
| EP0757073B1 (en) * | 1995-07-31 | 2004-10-27 | General Electric Company | Flame retardant polymer compositions |
| IT1283362B1 (en) * | 1996-07-30 | 1998-04-17 | Pirelli Cavi S P A Ora Pirelli | SELF-EXTINGUISHING CABLE WITH LOW EMISSION OF TOXIC AND CORROSIVE FUMES AND GASES |
| DE19820095A1 (en) * | 1998-05-06 | 1999-11-11 | Eilentropp Kg | Extrudable, halogen-free mixture |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1476241A (en) * | 1973-05-29 | 1977-06-10 | Square D Co | Arc-extinguishing materials |
| US3912650A (en) * | 1973-05-29 | 1975-10-14 | Square D Co | Hydrated zinc borate, dimethyl silicone resin arc extinguishing material |
| JPS523516A (en) * | 1975-06-28 | 1977-01-12 | Nikkei Giken:Kk | Free cutting, high ensile al alloy |
| US4189619A (en) * | 1978-01-27 | 1980-02-19 | Watson J | Fire protective mastic and fire stop |
| JPS5533567A (en) * | 1978-09-01 | 1980-03-08 | Hitachi Zosen Corp | Compound heat recovery method |
| JPS55152723A (en) * | 1979-05-18 | 1980-11-28 | Hitachi Cable Ltd | Preparation of fire-proof silicone foam |
| US4522985A (en) * | 1984-04-27 | 1985-06-11 | General Electric Company | Heat curable silicone-polyimide block copolymers |
| US4586997A (en) * | 1984-10-19 | 1986-05-06 | General Electric Company | Soluble silicone-imide copolymers |
-
1987
- 1987-06-03 GB GB8713015A patent/GB2193216B/en not_active Expired - Fee Related
- 1987-06-24 DE DE19873720769 patent/DE3720769A1/en not_active Ceased
- 1987-07-10 FR FR8709804A patent/FR2601958B1/en not_active Expired - Fee Related
- 1987-07-17 CA CA000542374A patent/CA1300777C/en not_active Expired - Fee Related
- 1987-07-24 JP JP18382187A patent/JPS6341565A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6341565A (en) | 1988-02-22 |
| FR2601958A1 (en) | 1988-01-29 |
| GB2193216B (en) | 1991-03-20 |
| GB2193216A (en) | 1988-02-03 |
| GB8713015D0 (en) | 1987-07-08 |
| FR2601958B1 (en) | 1990-09-21 |
| DE3720769A1 (en) | 1988-02-11 |
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