Classifications

• • 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
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L65/00—Compositions of macromolecular compounds obtained by reactions forming a carbon-to-carbon link in the main chain; Compositions of derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L71/00—Compositions of polyethers obtained by reactions forming an ether link in the main chain; Compositions of derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L79/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen with or without oxygen or carbon only, not provided for in groups C08L61/00 - C08L77/00
  • C08L79/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
  • C08L79/08—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors

Definitions

• This invention relates generally to thermoplastic materials useful, for example, to make aircraft interior parts and, more particularly to polyetherimide thermoplastic compositions which comprise anhydrous zinc borate and a fluorocarbon polymer.
• thermoplastic compositions that have improved flammability performance, and yet display at the same time such other desirable features as toughness, chemical, solvent and cleaner resistance, and ease of fabrication into finished components.
• Flame retarding additives such as triphenyl phosphate or aluminum trihydrate which generally possess low flammability have been mixed with engineering thermoplastics to reduce flammability of the thermoplastics .
• a blend of such a low flammability additive with high performance engineering thermoplastics often does not yield a useable flame-resistant composition.
• the low flammability additive may not be compatible, i.e. miscible with the engineering thermoplastic, at high enough concentrations to achieve significant flame retardance, or the additive may not be stable at the processing temperatures of the engineering thermoplastic.
• low flammability additives which are compatible with a particular engineering thermoplastic often cannot effectively lower the flammability or heat release of the thermoplastic. If the effect on flammability is merely a reduction due to dilution, amounts of the low-flammability additive necessary to achieve a desired reduction in flammability can adversely affect the physical properties or processability of the engineering thermoplastic.
• poly(aryl ether sulfone) examples of the polyarylene polyethers used in Barth's mixture.
• Barth does not disclose flame retardant thermoplastic compositions of zinc borate and a fluorocarbon polymer.
• Mixtures containing a fluorocarbon polymer, e.g., polytetrafluoroethylene, perfluorinated poly(ethylene-propylene) copolymer, or poly(vinylidene fluoride), with a number of engineering polymers including poly(aryl ether sulfones), are disclosed in European Patent Application No. 106,764.
• Blends of poly(aryl ether ketones) with non-crystalline copolymers of tetrafluoroethylene are disclosed in Petersen, U.S. Patent No. 4,777,214.
• Composite materials consisting of a mixture of poly(aryl ether sulfone), a fluorocarbon polymer, and carbon fibers or of a mixture of poly(aryl ether ketone) , a fluorocarbon polymer, and potassium titanate fibers are disclosed as useful for moldings in Japanese Patents 88/065,227B and 89/029,379B) .
• Zinc borate or boron compounds have been used in various thermoplastic compositions.
• Cella, et al., U.S. 4,833,190 discloses use of hydrated zinc borate as a smoke suppressant and flame retardant in silicone containing compositions.
• Anderson, U.S. 4,049,619 discloses a thermoplastic composition of a polysulfone, a flame retarding bis-phenoxy compound and an enhancing agent, which is disclosed as any of numerous metal oxides and other compounds .
• Zinc borate is disclosed as one possible enhancing agent. Buchert, et al. , U.S.
• 4,981,895 discloses use of a boron containing compound as the sole flame retardant in various high temperature thermoplastics, including polyamides, polyetherimides, liquid crystal polymers, polyether sulfones, and polyether ketones.
• Lohmeijer, et al., EP 0,364,729 discloses use of a boron containing compound and a fluorocarbon compound as flame retardants in numerous thermoplastics. None of these references disclose flame retardant polyetherimide compositions comprising anhydrous zinc borate and a non- fibrillating fluorocarbon polymer.
• thermoplastic compositions having improved heat release characteristics It is a specific object of the invention to provide thermoplastic compositions having improved flammability performance as measured by the U.S. mandated tests for aircraft interiors. It is another specific object to provide such compositions which are readily processable in both injection molding and sheet extrusion. It is another specific object to provide such compositions having chemical and solvent resistance. Other objects will appear below.
• the general object of the invention can be attained by thermoplastic compositions comprising at least one polyetherimide, anhydrous zinc borate and a non-fibrillating fluorocarbon polymer.
• the compositions of the invention display a combination of excellent mechanical properties, chemical resistance, and low flammability.
• compositions are useful in a number of applications, in particular for the construction of various panels and parts for aircraft interiors. None of the above references disclose or suggest a combination of zinc borate and a non-fibrillating fluorocarbon polymer in polyetherimide compositions.
• the invention is directed to thermoplastic compositions having improved heat release characteristics comprising at least one polyetherimide, anhydrous zinc borate and a non- fibrillating fluorocarbon polymer.
• the compositions of the invention show an improved effect on the heat release therefrom as measured by OSU Tests. (As used herein, the flammability performance and heat release characteristics of a composition are as measured by OSU Tests.)
• the amount of zinc borate and fluorocarbon polymer incorporated in the compositions of the invention is an amount sufficient to reduce the heat release from the compositions, compared to the same materials without the additives. This amount is preferably about 3.0 to about 12.0 parts by combined weight of zinc borate and the fluorocarbon polymer per 100 parts by weight polyetherimide.
• compositions of the invention display improved heat release characteristics and have excellent mechanical processability.
• the zinc borate and the fluorocarbon polymer do not decompose at necessary processing temperatures for the composition.
• the compositions are also readily melt fabricated to produce molded articles having aesthetically pleasing surfaces.
• the preferred compositions of the invention comprise a polyetherimide and a poly(aryl ether ketone) , and exhibit excellent solvent resistance .
• compositions comprise at least one polyetherimide mixed with anhydrous zinc borate and a low molecular weight, non-fibrillating fluorocarbon polymer as heat release retardants.
• the compositions can include, in addition to the polyetherimide, other thermoplastics, such as a poly(aryl ether ketone) or a poly (phenylene ether sulfone) .
• Applicants have found that the use of the zinc borate and the fluorocarbon polymer in the compositions of the invention results in materials having improved heat release performance.
• the preferred compositions of the invention comprise:
• compositions of the invention without Ti0 2 have excellent properties
• the preferred compositions include Ti ⁇ 2 because of better heat release performance and color matching possibilities.
• polyetherimides employed in the blends of this invention are well-known injection moldable engineering thermoplastics. Polyetherimides are characterized by high impact strengths, high temperature resistance and good processability.
• polyetherimides used for preparing the blends of this invention contain repeating groups of the formula
• T is -0- or a group of the formula
• Z is a member of the class consisting of (A)
• X is a member the group consisting of divalent radicals of the formulas
• R is a divalent organic radical selected from the group consisting of (a) aromatic hydrocarbon radicals having from 6 to about 20 carbon atoms and halogenated derivatives thereof, (b) alkylene radicals having from 2 to about 20 carbon atoms, cycloalkylene radicals having from 3 to about 20 carbon atoms and (c) divalent radicals of the general formula
• x is an integer from 1 to about 5.
• the polyetherimide may be a copolymer which, in addition to the etherimide units described above, further contains polyimide repeating units of the formula
• R is as previously defined and M is selected from the group consisting of
• polyetherimide copolymers and their preparation are described by Williams et al. in U.S. Patent No. 3,983,093.
• the polyetherimides can be prepared by any of the methods known to those skilled in the art, including those methods described in European Patent Application No. EPO 307 670 Al, published March 22, 1989.
• a preferred polyetherimide is of the general formula above wherein R is meta-phenylene and T is
• compositions of the invention may be used in the compositions of the invention.
• the polyetherimide can be mixed with a poly(aryl ether ketone) or a poly(aryl ether sulfone) .
• the amounts of additives used in the compositions are measured on a 100 parts combined weight of the polyetherimide and other thermoplastics.
• crystalline poly(aryl ether ketones) which are suitable for the compositions of the invention contain a repeating unit of one or more of the following formulae:
• Ar is independently a divalent aromatic radical selected from phenylene, biphenylene or naphthylene;
• n is an integer of 0 to 3;
• b, c, d, and e are 0 or 1, and preferably d is 0 when b is 1;
• poly(aryl ether ketones) examples include those h or more of the formulae:
• poly(aryl ether ketones) are prepared by any suitable method such as those well known in the art.
• One such method comprises heating a substantially equimolar mixture of at least one bisphenol and at least one dihalobenzenoid compound or at least one halophenol compound as described in Canadian Patent No. 847,963.
• Preferred bisphenols used in such a process include: hydroquinone,
• halo- and dihalobenzenoid compounds used in such a process include:
• the poly(aryl ether ketones) may also be produced by the process as described in U.S. Patent No. 4,176,222.
• This process comprises heating in the temperature range of 100°C to 400°C (1) a substantially equimolar mixture of (a) at least one bisphenol and (b) at least one dihalobenzenoid compound, and/or (2) at least one halophenol, in which in the dihalobenzenoid compound or halophenol the halogen atoms are activated by -CO- groups ortho or para thereto, with a mixture of sodium carbonate or bicarbonate and a second alkali metal carbonate or bicarbonate, ⁇ the alkali metal of said second alkali metal carbonate or bicarbonate having a higher atomic number than that of sodium, the amount of said second alkali metal carbonate or bicarbonate being such that there are 0.001 to 0.5 gram atoms of said alkali metal of higher atomic number per gram atom of sodium,the total amount of alkali metal carbon
• the poly(aryl ether ketones) may also be prepared according to the process as described in, for example, U.S. Defensive Publication T103,703 and U.S. Patent No. 4,396,755.
• reactants such as (a) an aromatic monocarboxylic acid, or (b) a mixture of at least one aromatic dicarboxylic acid and of an aromatic compound, or (c) combinations of (a) and (b) are reacted in the presence of a fluoroalkane sulphonic acid, particularly trifluoromethane sulphonic acid.
• -Ar * - is a divalent aromatic radical
• Y is halogen
• COY is an aromatically bound acyl halide group, wherein the diacyl halide is polymerizable with at least one aromatic compound described in (a) (ii) below, and
• -Ar'- is a divalent aromatic radical and H is an aromatically bound hydrogen atom, which compound is polymerizable with at least one diacyl halide described in (a) (i) above, or (b) at least one aromatic monoacyl halide of formula
• H-Ar"-COY where -Ar"- is a divalent aromatic radical and H is an aromatically bound hydrogen atom, Y is halogen, and COY is an aromatically bound acyl halide group, which monoacyl halide is self-polymerizable, or (c) a combination of (a) and (b) , is reacted in the presence of a fluoroalkane sulphonic acid.
• poly(aryl ether ketone) as used herein is meant to include homopolymers , copolymers, terpolymers, block copolymers and graft copolymers.
• any one or more of the repeating units (I) to (V) may be combined to form copolymers, etc.
• the preferred poly(aryl ether ketone) for use in the preferred compositions of the invention has repeating units of the formula:
• Such a poly(aryl ether ketone) is available commercially from Imperial Chemical Industries, Ltd. under the trademark VICTREX® PEEK.
• the poly(aryl ether ketones) have preferably reduced viscosities in the range of from about 0.8 to about 1.8 dl/g at measured in concentrated sulfuric acid at 25°C and at atmosperhic pressure, to provide compositions having excellent processability.
• a poly(aryl ether ketone) having a melt flow above 40 g./lO minutes at 400°C such as VICTREX®PEEK, grade 150P .
• a poly(aryl ether ketone) having a melt flow of about 1.0 to about 8.0 g./lO minutes at 400°C, such as VICTREX® PEEK, grade 450P is preferred.
• the amount of the poly(aryl ether ketone) present in compositions of the invention can be any amount, but preferably is about 20.0 parts to about 60.0 parts by weight per 100 parts combined weight of the poly(aryl ether ketone) and polyetherimide.
• Blend compositions of polyetherimides with less than 20.0 parts of the (poly(aryl ether ketone) display less improved solvent resistance, which is still acceptable for some applications, and those with more than 60.0 parts of the ketone display lesser impact properties. More preferably, the poly(aryl ether ketone) amount is about 20.0 parts to about 50.0 parts, since compositions with these amounts have an excellent
• the zinc borate used is anhydrous, having water amounts less than 0.2 wt.% of the zinc borate; hydrated zinc borate or zinc borates with greater water content can result in unprocessable compositions. Any suitable anhydrous zinc borate may be used.
• Anhydrous zinc borate of the formula 2ZnO-3B 2 0 3 having no measurable water content and a particle size of 11.8 microns is available as XPI-187 from U.S. Borax and is produced by thermal dehydration of zinc borate at 500°C.
• the amount of zinc borate is an effective amount to achieve low heat release, and generally is about 2.0 to about 8.0 parts by weight per 100 parts total weight of the first thermoplastic material.
• Amounts of zinc borate above about 8.0 parts do not provide further flammability improvement, while amounts below 2.0 parts may provide inadequate heat release retardation.
• about 3.0 to about 7.0 parts zinc borate are used.
• any suitable particle size of the zinc borate can be used, zinc borate having particle size of less than about 3.0 microns ⁇ 1.0 micron, and no particle larger than about 6.0 microns is preferred because compositions made with smaller particles have better heat release and impact performance.
• the non-fibrillating fluorocarbon polymers employed in the compositions of this invention are thermoplastic fluorinated polyolefins which have an essentially crystalline structure and have a melting point in excess of about 120°C. They are preferably a polymer of one or more perfluorinated unsaturated ethylenic monomers and, optionally, one or more other unsaturated ethylenic compounds.
• Suitable monomers include, for example, perfluorinated monoolefins, such as hexafluoropropylene or tetrafluoroethylene, and perfluoroalkyl vinyl ethers in which the alkyl group contains up to six carbon atoms, e.g., perfluoro (methyl vinyl ether) .
• the monoolefin is preferably a straight or branched chain compound having a terminal double bond and containing less than six carbon atoms, and more preferably two or three carbon atoms.
• the fluorocarbon polymers also include those in which a portion of the fluorine atoms have been replaced by other halogen atoms, such as chlorine or bromine.
• Preferred fluorocarbon polymers include polytetrafluoroethylene, polychloro- trifluoroethylene, polybromotrifluoroethylene, and copolymers thereof.
• Other suitable fluorinated polyolefins include polyperfluorobutadiene, polyhexafluoropropylene, fluorinated ethylene propylene copolymer, and perfluoro- alkoxy resin.
• a particularly preferred fluorinated polyethylene is polytetrafluoroethylene (referred to hereafter as "PTFE") because it works well in the compositions of the invention and is commercially available.
• polytetrafluoroethylenes are fully fluorinated poly- ethylenes of the basic chemical formula (-CF 2 -CF 2 -) s which contain about 78 percent by weight fluorine.
• Relatively low molecular weight fluorocarbon polymers are used because of their performance; compositions containing higher molecular weight fluorocarbon polymers (also referred to as fibrillating polymers) may result in lesser properties, particularly impact resistance.
• the molecular weights of preferred fluorocarbon polymers are less than about 100,000.
• the optimal molecular weight may vary from one fluorocarbon polymer to another, and can be determined empirically, such as by measurement of melting point.
• a suitable non-fibrillating fluorocarbon polymer is a polytetrafluoroethylene, POLYMIST® F5A available from Ausimont, Morristown, New Jersey.
• the fluorocarbon polymers are employed preferably in the form of finely divided solids having a particle size of less than about 5.0 microns because such solids are more easily dispersed and result in better impact properties.
• the fluorocarbon polymers should be highly dispersed in the thermoplastic matrix to produce low flammability products . Dispersibility is related to the molecular weight and/or particle size of the fluorocarbon polymer. The uniformity of the dispersion of the fluorocarbon polymer may be determined by observing the physical appearance of the molded product or test specimen and by measuring the degree of elongation at break of the product. Low elongation values may indicate poor dispersion.
• the fluorocarbon polymer is preferably employed in amounts of about 1.0 part by weight to about 5.0 parts by weight based on 100 parts by weight first thermoplastic material. Although they can be used, concentrations of the fluorocarbon polymer above 5.0 parts by weight are undesirable since these amounts can adversely affect the moldability and can create a perlescent effect, making color matching a problem.
• Ti0 2 provides increased ability for color matching for particular end uses, but Ti0 2 should not be used for black colored applications .
• the titanium dioxide used in the instant compositions is commercially available, and any suitable Ti0 2 can be used.
• the particle size of the Ti0 is preferably below 5.0 microns because higher particle sizes can deleteriously affect the physical properties of the compositions.
• Any of the available crystalline forms of the titanium dioxide may be used, with the rutile form preferred due to its superior pigment properties.
• the total amount of Ti0 2 used is preferably below about
• compositions employ about 3.0 to about 7.0 parts by weight zinc borate, about 1.0 to about 4.0 parts by weight fluorocarbon polymer and about 3.0 to about 7.0 parts by weight Ti0 2 , per 100 parts by weight of the first thermoplastic material.
• any suitable procedure can be used to compound the compositions of the invention, and the solid components can be mixed with each other in any desired order.
• Applicants prefer to blend desirable amounts of the all solids present and then heat the resulting mixture to above the melting point of the highest melting polymer in the mixture.
• the molten mixture is then mixed for any suitable period to achieve thorough dispersion of the additive(s) and mixing of the polymers present, and then extruded and cooled into any desirable shape.
• Such a process can be conveniently carried out with commercial extruders such as those available from Berstorff Tire Corporation.
• the compositions of the invention which comprise Ti0 2 , it is not necessary to add the oxide initially.
• the composition containing zinc borate can be compounded first, and desirable amounts of Ti0 can be mixed in later.
• compositions of this invention may be included in the compositions of this invention.
• additives include plasticizers; pigments; anti-oxidants; reinforcing agents, such as glass fibers; thermal stabilizers; ultraviolet light stabilizers; impact modifiers; mold release agents and the like.
• the compositions of the present invention display excellent fabricability characteristics . They may be fabricated into any desired shape, i.e. moldings, films, fibers, and the like. They are particularly suited for the construction of various panels and parts for aircraft interiors .
• PEI - ULTEM® 1000 or ULTEM® 1010 which are polyetherimide of the same general formula, but differing in melt viscosity, available commercially from General Electric Company.
• VICTREX® PEEK grade 150P, having a melt viscosit at 400 °C of 0.11 - 0.19 KNS/m 2 .
• F5A a polytetrafluoroethylene of low molecular weight (non-fibrillating) , available from Ausimont, under the trademark POLYMIST F5A®.
• ZnB anhydrous zinc borate, XPI-187 from U.S. Borax.
• All materials were prepared by first dry blending the components using a mechanical blender (turned end over end) . They were then compounded using a Berstorff ZE25, twenty- five mm co-rotating twin-screw extruder.
• the zone temperatures in the extruder were: Feed zone, 290-300°C; Zones 2 and 3, 340-365°C; Zones 4 and 5, 340-355°C; Zone 6, 330-355°C; and Zone 7 (Die), 335-355°C.
• the melt temperature ranged from 350°C to 395°C. Screw speeds were 170 to 250 rpm and head pressure ranged from 180-700 psi; varying with the materials compounded.
• Example 1 OSU Test specimens were made for Example 1 by compression molding of the compounded mixture in a South Bend press. Mold pressure was 500 psi for 5 minutes, then raised to 30,000 psi for the next 3 minutes, at 700°F. The mold was cooled for 10 minutes before releasing pressure. The 80 mil thick, 6x6 inch test specimens were cut from the molded material. Test specimens for Examples 2 and 3 were made by extrusion of the resins and additives in a 1" Sterling extruder. A small amount, 3 grams per 12 lbs. resin, of calcium stearate was added as a processing aid. Melt temperature was 660°F. The extruded, 60 mil thick sheet was cut into the test specimens.
• Example 1 used ULTEM® 1000 and Example 2 and 3 used ULTEM® 1010.
• Example 2 used 50 parts by weight PEI and 50 parts by weight PK per 100 parts combined weight PEI and PK, while Example 3 used 40 parts by weight PEI and 60 parts by weight PK per 100 parts combined weight PEI and PK.
• Table 1 lists test details, including sample composition and results .
• Example 1 used ULTEM® 1000 and Example 2 and 3 used ULTEM® 1010.
• Example 2 used 50 parts by weight PEI and 50 parts by weight PK per 100 parts combined weight PEI and PK, while Example 3 used 40 parts by weight PEI and 60 parts by weight PK per 100 parts combined weight PEI and PK.
• Table 1 lists test details, including sample composition and results .
• Example 1 used ULTEM® 1000 and Example 2 and 3 used ULTEM® 1010.
• Example 2 used 50 parts by weight PEI and 50 parts by weight PK per 100 parts combined weight PEI and PK
• Example 3 used 40 parts by weight PEI and 60 parts by weight PK
• ZnB and F5A are parts by weight per 100 parts by weight PEI or PEI/PK mixture.

Applications Claiming Priority (2)

Publications (2)

Family

ID=24165815

Family Applications (1)

Country Status (4)

Families Citing this family (4)

Citations (1)

Family Cites Families (4)

• 1991
  • 1991-06-07 CA CA 2064886 patent/CA2064886A1/en not_active Abandoned
  • 1991-06-07 WO PCT/US1991/004017 patent/WO1992000348A1/en not_active Application Discontinuation
  • 1991-06-07 EP EP19910913734 patent/EP0489152A4/en not_active Withdrawn
  • 1991-06-07 JP JP91513038A patent/JPH05505417A/ja active Pending

Patent Citations (1)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events