CA1099050A - Flame retardant rigid thermoplastic foams - Google Patents
Flame retardant rigid thermoplastic foamsInfo
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- CA1099050A CA1099050A CA273,065A CA273065A CA1099050A CA 1099050 A CA1099050 A CA 1099050A CA 273065 A CA273065 A CA 273065A CA 1099050 A CA1099050 A CA 1099050A
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- Prior art keywords
- polycarbonate
- thermoplastic
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- flame retardant
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/0061—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof characterized by the use of several polymeric components
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2369/00—Characterised by the use of polycarbonates; Derivatives of polycarbonates
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2469/00—Characterised by the use of polycarbonates; Derivatives of polycarbonates
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- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
FLAME RETARDANT RIGID THERMOPLASTIC FOAMS
Abstract of the Disclosure Shaped flame retardant rigid thermoplastic foams are provided having high impact strength and superior smoke density and superior radiant panel test values. Blends of dichloroethylene bisphenol polycarbonate and a high perform-ance thermoplastic polymer, such as isopropylidene bis-phenol polycarbonate are injection foam molded under melt conditions to a variety of shaped structures.
Abstract of the Disclosure Shaped flame retardant rigid thermoplastic foams are provided having high impact strength and superior smoke density and superior radiant panel test values. Blends of dichloroethylene bisphenol polycarbonate and a high perform-ance thermoplastic polymer, such as isopropylidene bis-phenol polycarbonate are injection foam molded under melt conditions to a variety of shaped structures.
Description
~9g~SO
FL~ME RETARDA~T RIGID THERMOPLASTIC FOAMS
The present invention relates to high perform-ance flame retardant rigid thermoplastic foams having outstanding flame resistance as evidenced by low radiant panel test values. More particularly, the present inven-tion relates to shaped foamed blends of dichloroethylene bisphenol polycarbonate and high performance thermoplastic organic polymer.
Prior to the present invention, rigid thermo-plastic foam having high impact strength, such as poly-carbonate foam has become recognized by the plastics industry as an attractive material with many valuable uses.
High performance rigid thermoplastic foam, for example, is being used as a substitute for many light weight metals, such as aluminum, in the automotive industry for making automobile roof tops and in the electronics industry as housing for electronic components. Rigid thermoplastic foams have become increasingly attractive to the electronic data processing industry as a substitute for metal because of the ease of fabrication of thermoplastic foam parts by conventional injection molding techniques as compared to the fabrication of metal parts which have to be stamped out and machined. Although rigid thermoplastic foam has many attractive features as compared to light weight metal, ~9~50 such as aluminum, because of ease of fabrication, stringent flame retardant requirements have limited the use of high performance rigid thermoplastic foam as housing for certain electronic components, such as computers. A test which has been applied by industry to screen rigid thermoplastic foam based on flammability evaluation, is the radiant panel test ASTM-E-162-67.
In accordance with the test, an increase in the "Is value" which hereinafter will indicate the radiant panel test value, indicates a reduction in flame retarda-tion. Experience has shown that the flame retardant qualities of thermoplastics often are substantially reduced when the thermoplastic is converted to a rigid cellular foam. As a result, efforts to improve the flame retardant properties of rigid cellular foams have been generally based on the approach of improving the flame retardant properties of the original thermoplastic source material and then converting it to the cellular state. For example, when a bisphenol-A polycarbonate foam panel was evalu-ated in the above described ASTM test, its "Is value" was found to be at least twice as great as compared to a bis-phenol-A polycarbonate panel of the same thickness. The same result was observed when conventional flame retardant ~9g~50 materials were added to the polycarbonate which, in the unfoamed state, produced a satisfactory radiant panel test value. However, when the same polycarbonate formulation was converted to a rigid foam, its "Is value" was greater than 15 which failed the requirements of the electronic data processing industry as defined by UL Bulletin 484.
As a result, the market potential for flame retardant rigid thermoplastic foam has been severely restricted because the foaming process inherently appeared to convert the thermoplastic to an unacceptable flame retardant material even though its strength to weight ratio and ease of fabrication were highly attractive.
The present invention is based on the discovery that certain dichloroethylene bisphenol polycarbonates and blends of such materials with particular high performance thermoplastic polymers can be converted to shaped flame retardant rigid thermoplastic foams exhibiting spectacular flame retardant properties. Surprisingly, the Is values of these rigid thermoplastic foams are either the same as or not significantly greater than the Is values of the original high performance precursor thermoplastic material used in making such foams.
B
1~9~SO RD-8142 There is provided by the present invention, shaped flame retardant rigid thermoplastic foams having a density of from 0.5 g/cc to 1.2 g/ec, and a Gardner impact strength of at least 10 ft-lbs, which is the product obtained by the injection foam molding of a melt of a material com-prising by weight, (A) at least about 5% of a thermoplastic poly-earbonate having an intrinsic viscosity of at least 0.35 dl/g and eonsisting essentially of chemically combined units of the formula -R-C-Rl- O -C - O -(1) "
X/ \
and eorrespondingly (B) up to about 95% of a thermoplastie polymer seleeted from the elass eonsisting of polyearbonate, poly-arylene oxide, polyalkyleneterephthalate, polyvinylaromatie and polyolefin, where R and Rl are divalent aromatie radieals having from 6-13 earbon atoms, X is a halogen atom, and X is seleeted from X and hydrogen.
Ineluded by R and Rl of formula 1, are for example, phenylene, xylylene, diehlorophenylene, tolylene, naphthal-ene, ete. Radieals ineluded by X are, for example, ehlorine, bromine, ete.; R and Rl and X and Xl ean be the same or different radicals respeetively.
1~99~50 The polycarbonates consisting essentially of chemically combined units of formula (1) "or haloethylene polycarbonate", can be made by standard procedures involv-ing for example, the phosgenation of a haloethylene bis-phenol of the formula
FL~ME RETARDA~T RIGID THERMOPLASTIC FOAMS
The present invention relates to high perform-ance flame retardant rigid thermoplastic foams having outstanding flame resistance as evidenced by low radiant panel test values. More particularly, the present inven-tion relates to shaped foamed blends of dichloroethylene bisphenol polycarbonate and high performance thermoplastic organic polymer.
Prior to the present invention, rigid thermo-plastic foam having high impact strength, such as poly-carbonate foam has become recognized by the plastics industry as an attractive material with many valuable uses.
High performance rigid thermoplastic foam, for example, is being used as a substitute for many light weight metals, such as aluminum, in the automotive industry for making automobile roof tops and in the electronics industry as housing for electronic components. Rigid thermoplastic foams have become increasingly attractive to the electronic data processing industry as a substitute for metal because of the ease of fabrication of thermoplastic foam parts by conventional injection molding techniques as compared to the fabrication of metal parts which have to be stamped out and machined. Although rigid thermoplastic foam has many attractive features as compared to light weight metal, ~9~50 such as aluminum, because of ease of fabrication, stringent flame retardant requirements have limited the use of high performance rigid thermoplastic foam as housing for certain electronic components, such as computers. A test which has been applied by industry to screen rigid thermoplastic foam based on flammability evaluation, is the radiant panel test ASTM-E-162-67.
In accordance with the test, an increase in the "Is value" which hereinafter will indicate the radiant panel test value, indicates a reduction in flame retarda-tion. Experience has shown that the flame retardant qualities of thermoplastics often are substantially reduced when the thermoplastic is converted to a rigid cellular foam. As a result, efforts to improve the flame retardant properties of rigid cellular foams have been generally based on the approach of improving the flame retardant properties of the original thermoplastic source material and then converting it to the cellular state. For example, when a bisphenol-A polycarbonate foam panel was evalu-ated in the above described ASTM test, its "Is value" was found to be at least twice as great as compared to a bis-phenol-A polycarbonate panel of the same thickness. The same result was observed when conventional flame retardant ~9g~50 materials were added to the polycarbonate which, in the unfoamed state, produced a satisfactory radiant panel test value. However, when the same polycarbonate formulation was converted to a rigid foam, its "Is value" was greater than 15 which failed the requirements of the electronic data processing industry as defined by UL Bulletin 484.
As a result, the market potential for flame retardant rigid thermoplastic foam has been severely restricted because the foaming process inherently appeared to convert the thermoplastic to an unacceptable flame retardant material even though its strength to weight ratio and ease of fabrication were highly attractive.
The present invention is based on the discovery that certain dichloroethylene bisphenol polycarbonates and blends of such materials with particular high performance thermoplastic polymers can be converted to shaped flame retardant rigid thermoplastic foams exhibiting spectacular flame retardant properties. Surprisingly, the Is values of these rigid thermoplastic foams are either the same as or not significantly greater than the Is values of the original high performance precursor thermoplastic material used in making such foams.
B
1~9~SO RD-8142 There is provided by the present invention, shaped flame retardant rigid thermoplastic foams having a density of from 0.5 g/cc to 1.2 g/ec, and a Gardner impact strength of at least 10 ft-lbs, which is the product obtained by the injection foam molding of a melt of a material com-prising by weight, (A) at least about 5% of a thermoplastic poly-earbonate having an intrinsic viscosity of at least 0.35 dl/g and eonsisting essentially of chemically combined units of the formula -R-C-Rl- O -C - O -(1) "
X/ \
and eorrespondingly (B) up to about 95% of a thermoplastie polymer seleeted from the elass eonsisting of polyearbonate, poly-arylene oxide, polyalkyleneterephthalate, polyvinylaromatie and polyolefin, where R and Rl are divalent aromatie radieals having from 6-13 earbon atoms, X is a halogen atom, and X is seleeted from X and hydrogen.
Ineluded by R and Rl of formula 1, are for example, phenylene, xylylene, diehlorophenylene, tolylene, naphthal-ene, ete. Radieals ineluded by X are, for example, ehlorine, bromine, ete.; R and Rl and X and Xl ean be the same or different radicals respeetively.
1~99~50 The polycarbonates consisting essentially of chemically combined units of formula (1) "or haloethylene polycarbonate", can be made by standard procedures involv-ing for example, the phosgenation of a haloethylene bis-phenol of the formula
(2) HO-R -C-R-OH
/c\
where R, Rl, X and ~1 are as previously defined. The bisphenols of formula (2) can be made by procedures described in S. Porejko and Z. Wielgosz, Polimery, 13, 55 (1968).
Preferably, the haloethylene polycarbonate has an intrinsic viscosity in the range of between 0.4 to 0.65 dl/g.
In addition to 1,1-bis(p-4-hydroxyphenyl)-2,2-dichloroethylene, the haloethylene bisphenols of formula (2) also include H()~ ~OH
~C~
Cl Cl Cl ~ ~ 1 Cl Cl R~-8142 1~9~5C~
OH OH
, etc.
Br Br - In addition to the above described haloalkylene polycarbonate, and blends thereof with thermoplastic organic material, the flame retardant foams of the present invention also can be made from copolymers by phosgenating mixtures of bisphenols of formula (2) with bisphenols of the formula,
/c\
where R, Rl, X and ~1 are as previously defined. The bisphenols of formula (2) can be made by procedures described in S. Porejko and Z. Wielgosz, Polimery, 13, 55 (1968).
Preferably, the haloethylene polycarbonate has an intrinsic viscosity in the range of between 0.4 to 0.65 dl/g.
In addition to 1,1-bis(p-4-hydroxyphenyl)-2,2-dichloroethylene, the haloethylene bisphenols of formula (2) also include H()~ ~OH
~C~
Cl Cl Cl ~ ~ 1 Cl Cl R~-8142 1~9~5C~
OH OH
, etc.
Br Br - In addition to the above described haloalkylene polycarbonate, and blends thereof with thermoplastic organic material, the flame retardant foams of the present invention also can be made from copolymers by phosgenating mixtures of bisphenols of formula (2) with bisphenols of the formula,
(3) HO-Z-OH
where Z is selected from R and R -Q-R , R is selected from R radicals and Q is selected from, ,R3 divalent cycloaliphatic radicals, oxyaryleneoxy radicals, :
sulfonyl, sulfinyl, oxy, thio, fluorenyl, phenolphthalein and R3 is selected from C(l 8) alkyl, R and halogenated derivatives. Typical of the bisphenols of formula 3 are, for example, 2,2-bis(4-hydroxyphenyl)propane (Bisphenol-A);
2,4-dihydroxydiphenylmethane; bis(2-hydroxyphenyl)methane;
bis(4-hydroxyphenyl)methane; 1,1-bis(4-hydroxyphenyl)ethane;
1~99~50 1,2-bis(4-hydroxyphenyl)ethane; 1,1-bis(4-hydroxy-2-chloro-phenyl)ethane; l,l-bis(2,5-dimethyl-4-hydroxyphenyl)ethane, 1,3-bis(3-methyl-4-hydroxyphenyl)propane; 2,2-bis(3-iso-propyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl) hexylfluoropropane, etc. In addition, 4,4'-sec-butylidene-diphenol, 4,4'-methylene(2,6-ditert-butylphenol), 2,2'-methylene(4-methyl-6-tert-butylphenol), bis(4-hydroxy-phenyl)phenylmethane, bis(4-hydroxyphenyl)cyclohexyl methane, 1,2-bis(4-hydroxyphenyl)-1,2-diphenyl ethane, etc. In add-ition to the above bisphenols there are also included within the scope of the dihydroxy compounds of Formula 3 dihydroxybenzenes such as hydroquinone resorcinol, etc.,
where Z is selected from R and R -Q-R , R is selected from R radicals and Q is selected from, ,R3 divalent cycloaliphatic radicals, oxyaryleneoxy radicals, :
sulfonyl, sulfinyl, oxy, thio, fluorenyl, phenolphthalein and R3 is selected from C(l 8) alkyl, R and halogenated derivatives. Typical of the bisphenols of formula 3 are, for example, 2,2-bis(4-hydroxyphenyl)propane (Bisphenol-A);
2,4-dihydroxydiphenylmethane; bis(2-hydroxyphenyl)methane;
bis(4-hydroxyphenyl)methane; 1,1-bis(4-hydroxyphenyl)ethane;
1~99~50 1,2-bis(4-hydroxyphenyl)ethane; 1,1-bis(4-hydroxy-2-chloro-phenyl)ethane; l,l-bis(2,5-dimethyl-4-hydroxyphenyl)ethane, 1,3-bis(3-methyl-4-hydroxyphenyl)propane; 2,2-bis(3-iso-propyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl) hexylfluoropropane, etc. In addition, 4,4'-sec-butylidene-diphenol, 4,4'-methylene(2,6-ditert-butylphenol), 2,2'-methylene(4-methyl-6-tert-butylphenol), bis(4-hydroxy-phenyl)phenylmethane, bis(4-hydroxyphenyl)cyclohexyl methane, 1,2-bis(4-hydroxyphenyl)-1,2-diphenyl ethane, etc. In add-ition to the above bisphenols there are also included within the scope of the dihydroxy compounds of Formula 3 dihydroxybenzenes such as hydroquinone resorcinol, etc.,
4,4'-dihydroxydiphenyl, 2,2'-dihydroxydiphenyl, 2,4'-di-hydroxydiphenyl, etc.
The "haloalkylene polycarbonate copolymers" can consist essentially of from about 5 mol percent to about 99 mol percent of formula (1) units and from about 1 mol percent to 95 mol percent of units of the formula, (4) 0 -OZOCO-where Z is as previously defined. Phosgenation of the mixture of bisphenols of formulas 2 and 3 can be effected by standard procedures in the presence of an acid acceptor such as calcium oxide, sodium hydroxide, etc.
1~99~50 The haloalkylene polycarbonate of the present invention also can be blended with one or more high per-formance thermoplastic polymers, such as polycarbonates, for example, polymers derived from phosgenating formula 3 bisphenols, such as bisphenol fluorenone, etc.; polyphenyl-ene oxides, polyalkyleneteraphthalates, for example, poly-ethyleneteraphthalate, polybutyleneteraphthalate, etc.;
polyolefins, for example, polyethylene, polypropylene, ethylene-propylene copolymers, etc.; and high impact polystyrene, etc. Some of these blends are described in Infra-red Spectroscopic Investigation of Polycarbonates, Z. Wielgosz, Z. Boranowska and K. Janicka, Plaste and Kautschuk, 19 (12), 902-904 (1972). The blends of the dihaloethylene polycarbonates with the aforementioned thermoplastic polymers can be readily achieved by standard melt extrusion techniques preferably a blend of from 30%
to 99% of the dihaloethylene polycarbonate is made with from 70% to 1% of polycarbonate. The polycarbonates which can be employed, for example, are 140 grade LexanR poly-carbonate of the General Electric Company. In addition blends of the dihaloethylene polycarbonate can be made with General Electric Noryl resin, or General Electric ppoR resin, where there can be utilized from 20% to 95%
of the dihaloethylene polycarbonate. In addition, 20%
to 95% of the dihaloalkylene polycarbonate can be blended 10~9~50 with from 80% to 5% of polyalkylene terephthalate resins, for example, polybutylene terephthalate or polyethylene terephthalate, etc. In addition to the aforementioned thermoplastic polymers, the dihaloalkylene polycarbonates, or blends thereof, can be further blended with from 2%
to 60% by weight of glass fiber, and preferably from 4%
to 25% by weight of glass fiber based on the total weight of thermoplastic polymer and glass fibers in the blend.
In addition to glass fiber, other fillers can be used, such as clay, glass spheres, silica, barium carbonate, silicon carbide whiskers, etc.
In the practice of the invention, the dihaloalkyl-ene polycarbonate which hereinafter will signify polycarbon-ate consisting essentially of units of formula (1), or a mixture of units of formulas (1) and (3), or blends of such dihalo alkylene polycarbonate with other thermoplastic polymers as previously identified, or the blends of such thermoplastic material with a glass fiber and/or other fillers can be blended with a blowing agent by standard procedure in the form of a dry powder, in an extruded pelletized form, in the form of an extruded thermoplastic sheet, etc., based on the melt characteristics of the thermoplastic polymer or blend and the decomposition temperature of the blowing agent. In instances where the _ g _ 1(339~50 decomposition temperature of the blowing agent is below or about the temperature at which the blends with the dihalo-alkylene polycarbonate can be melt extruded, it is preferred to make the resulting thermoplastic blend in the form of a dry powder. Blowing agents exhibiting maximum decomposi-tion rates at temperatures at least 25 greater than the melt extrusion temperature of the dihaloalkylene polycarbon-ate can provide for extrudable foamable blends or concen-trates which can be readily pelletized. Preferably, the blowing agents used in making the foams of the present invention are the dihydrooxidiazinones, as taught in my United States Patent Number 4,097,425, dated June 27, 1978 and assigned to the same assignee as the present invention. In instances where the foamable blend can be pelletized to concentrates having from about 1% to 25% by weight or more of the blowing agent based on the total weight of blend, it can be further melt extruded with additional dihaloalkylene polycarbonate to make the thermoplastic foam of the present invention.
In addition to the above described dihydrooxi-diazinones, other blowing agents which can be used in com-bination with the dihaloalkylene polycarbonate are, for example, 5-phenyltetrazole and diisopropylhydrazodicar-boxylate. In addition to convention blowing agents, foaming l~g9~0 of the dihaloalkylene polycarbonate can be achieved by direct use of inert gases, such as nitrogen by a procedure described by Angel patent 3,436,446. Injection molding of the dihaloalkylene polycarbonates of the present inven-tion can be performed by standard techniques. The afore-mentioned blowing agents or other conventional means of blowing to produce shaped foam structures at temperatures in the range of between 470F to 650E. Included by the shaped foam structures having flame retardant properties which can be melt extruded are, for example, computer housing parts, electrical appliances, business machine housings, automobile roof tops, food handling equipment, furniture parts, etc.
In order that those skilled in the art will be better able to practice the invention, the following examples are given by way of illustration and not by way of limitation. A11 parts are by weight.
Example 1.
A mixture of 26.25 parts of 1,1-dichloro-2,2-bis(4-hydroxyphenyl)ethylene, .026 part of sodium gluconate, 0.237 part of phenol, 0.142 part of triethylamine, 123 parts of methylene chloride and about 75 parts of water is stirred for about 10 109~C~50 minutes at a temperature of about 28C. There is then added to the mixture, an aqueous sodium hydroxide solution in an amount to adjust the pH of the aqueous phase of the mixture to approximately 10.
While the mixture is being thoroughly agitated, phosgene is introduced at a rate of about 12.24 parts per hour while a 20~ aqueous sodium hydroxide solution is added in an amount sufficient to maintain the pH of the aqueous phase of the mixture at 10. Phosgenation of the mixture is continued for about 3/4 of an hour under these conditions and then the rate of phosgenation is reduced to about 6.8 parts per hour while maintaining the pH of the ! aqueous phase to a range of about 11 to 11.5. The phosgen-ation of the mixture is then continued for about 50 minutes.
The above reaction mixture is then diluted with about 100 parts of methylene chloride, and washed alterna-tively with dilute hydrochloric acid, dilute sodium hydroxide and water. The mixture is then centrifuged and filtered and thereafter steam precipitated. There is obtained 26 pounds of product after the precipitate is recovered and dried at 80C. Based on method of pre-paration, the product is l,l-dichloro-2,2-bis(4-hydroxy-phenyl)ethylene polycarbonate having an intrinsic viscosity 1~9~50 of 0.51 dl/gm in chloroform at 25C.
The above described dichloroethylene polycarbon-ate is blended with 5-phenyl-3,6-dihydro-1,3,4-oxidiazin-2-one and glass fiber to produce a blend having .5% by weight of blowing agent and 5~ by weight of glass fiber. The mixture is then melt extruded into pellets at 500F.
In accordance with ASTM-E-162-67, 6" x 18" x 1/4"
test panels are prepared by foam molding the above blend from the above described pellets at 575F. This material has a Gardner Impact Value of about 25-37.5 ft-lb, an intrinsic --viscosity of 0.34 dl/gm, and a density of about 1.07. Equi-valent test panels are also prepared from a blend of the above described dichloroethylene polycarbonate and 5~ by weight of glass fiber free of blowing agent. The test panels are then used in evaluating the flame retardant properties of the glass filled dichloroethylene polycarbonate and the rigid foam derived therefrom in accordance with ASTM-E-162-67.
It is found that the unfoamed test panel has an Is value of 0 which is equivalentto asbestos. The foamed panel is found to have an Is value of 0.8 indicating the foaming of the original dichloroethylene polycarbonate glass fiber blend does not significantly reduce the flame retardant properties of the original blend.
1~99~
Example 2 A blend is prepared of about equal parts by weight of the dichloroethylene polycarbonate of Example 1 and a Bisphenol-A polycarbonate having an intrinsic viscosity of about 0.55 dl/g in chloroform at 25C, along with 5% by weight of the total of glass fiber and 0.5% by weight of the blow-ing agent of Example 1. The blend is melt extruded into pellets at 500F. Pellets are also prepared from the same blend free of blowing agent.
A 6" x 18" test panel is prepared following the procedure of Example 1 by foam molding the blend at 600F.
The foamed blend has an Is value of 3.9 which is substan-tially equivalent to the 3.7 value for the unfoamed blend.
The foamed blend also has an intrinsic viscosity of about 0.45 dl/g in chIoroform at 25C, a Gardner Impact Value greater than 50 ft-lb and a density of about 1.
Example 3.
A blend is prepared of 20 parts of the dichloro-ethylene polycarbbnate of Example 1 and 80 parts of the Bisphenol-A polycarbonate of Example 2 along with 5% by weight of the total of glass fiber.
A melt of the above blend is processed at 575F
in the extruder of a Springfield Case structural foam mold-ing machine using nltrogen gas at 1500 psig. The melt is injected in about 0.08 sec. in a 6" x 18" x 1/4" cavity ~(~9~50 maintained at about 200F. A 75 sec. cycle cool down time is required. There is obtained a 6" x 18" x 1/4" foam test panel having an Is value of 6 which is substantially the same as the Is value of the unfoamed blend. The density of the foam is 1.05; it has an intrinsic viscosity of 0.51 and a Gardner Impact of greater than 75.
Example 4 A blend of 75 parts of the dichloroethylene polycarbonate of Example 1 and 25 parts of an ABS resin is pelletized at 500F with .5~ by weight of the blend of the blowing agent of Example 1, and 5% by weight of glass fiber.
r~est panels are prepared by foam molding the blend at 575F. A comparison of Is values between foamed and unfoamed 6" x 18" x 1/4" test panels in accordance with ASTM-E-162-67 shows a 12.0 for the unfoamed panel and a 12.5 for the foamed panel.
Example 5.
A mixture of 1,1-dichloro-2,2-bis(4-hydroxy-phenyl)ethylene and 2,2-bis(4-hydroxyphenol)propane (Bisphenol-A) is phosgenated in accordance with the pro-cedures of Example 1. There is used 13.12 parts of the dichloroethylene bisphenol and 10.65 parts of Bisphenol-A.
There is obtained a copolymer consisting essentially of chemically co~bined dichloroethylene bisphenol units and Bisphenol-A units.
1CS99~50 The above-described copolymer is pelletized with 5-phenyl-3,6-dihydro-1,3,4-oxidiazin-2-one and glass fiber as in Example 1.
It is found that the Is value of the unfoamed panel is 3.8 while the foamed panel has an I of 4Ø
Although the above examples are limited to only a few of the very many shaped foamed articles which can be made in accordance with the practice of the present inven-tion, it should be understood that the materials used in making such foams can vary widely with respect to the nature of the haloethylene polycarbonate, the thermoplastic polymer used in combination thereof, or the copolymer having chemically combined units of formula 1 and units of the formula, o -O-Z-O-C-where Z is as previously defined. In addition, the means for converting such thermoplastic material under melt foaming conditions also can vary widely based on the nature of the foaming agent employed, such as an oxadiazin-one, inert gas, etc.
The "haloalkylene polycarbonate copolymers" can consist essentially of from about 5 mol percent to about 99 mol percent of formula (1) units and from about 1 mol percent to 95 mol percent of units of the formula, (4) 0 -OZOCO-where Z is as previously defined. Phosgenation of the mixture of bisphenols of formulas 2 and 3 can be effected by standard procedures in the presence of an acid acceptor such as calcium oxide, sodium hydroxide, etc.
1~99~50 The haloalkylene polycarbonate of the present invention also can be blended with one or more high per-formance thermoplastic polymers, such as polycarbonates, for example, polymers derived from phosgenating formula 3 bisphenols, such as bisphenol fluorenone, etc.; polyphenyl-ene oxides, polyalkyleneteraphthalates, for example, poly-ethyleneteraphthalate, polybutyleneteraphthalate, etc.;
polyolefins, for example, polyethylene, polypropylene, ethylene-propylene copolymers, etc.; and high impact polystyrene, etc. Some of these blends are described in Infra-red Spectroscopic Investigation of Polycarbonates, Z. Wielgosz, Z. Boranowska and K. Janicka, Plaste and Kautschuk, 19 (12), 902-904 (1972). The blends of the dihaloethylene polycarbonates with the aforementioned thermoplastic polymers can be readily achieved by standard melt extrusion techniques preferably a blend of from 30%
to 99% of the dihaloethylene polycarbonate is made with from 70% to 1% of polycarbonate. The polycarbonates which can be employed, for example, are 140 grade LexanR poly-carbonate of the General Electric Company. In addition blends of the dihaloethylene polycarbonate can be made with General Electric Noryl resin, or General Electric ppoR resin, where there can be utilized from 20% to 95%
of the dihaloethylene polycarbonate. In addition, 20%
to 95% of the dihaloalkylene polycarbonate can be blended 10~9~50 with from 80% to 5% of polyalkylene terephthalate resins, for example, polybutylene terephthalate or polyethylene terephthalate, etc. In addition to the aforementioned thermoplastic polymers, the dihaloalkylene polycarbonates, or blends thereof, can be further blended with from 2%
to 60% by weight of glass fiber, and preferably from 4%
to 25% by weight of glass fiber based on the total weight of thermoplastic polymer and glass fibers in the blend.
In addition to glass fiber, other fillers can be used, such as clay, glass spheres, silica, barium carbonate, silicon carbide whiskers, etc.
In the practice of the invention, the dihaloalkyl-ene polycarbonate which hereinafter will signify polycarbon-ate consisting essentially of units of formula (1), or a mixture of units of formulas (1) and (3), or blends of such dihalo alkylene polycarbonate with other thermoplastic polymers as previously identified, or the blends of such thermoplastic material with a glass fiber and/or other fillers can be blended with a blowing agent by standard procedure in the form of a dry powder, in an extruded pelletized form, in the form of an extruded thermoplastic sheet, etc., based on the melt characteristics of the thermoplastic polymer or blend and the decomposition temperature of the blowing agent. In instances where the _ g _ 1(339~50 decomposition temperature of the blowing agent is below or about the temperature at which the blends with the dihalo-alkylene polycarbonate can be melt extruded, it is preferred to make the resulting thermoplastic blend in the form of a dry powder. Blowing agents exhibiting maximum decomposi-tion rates at temperatures at least 25 greater than the melt extrusion temperature of the dihaloalkylene polycarbon-ate can provide for extrudable foamable blends or concen-trates which can be readily pelletized. Preferably, the blowing agents used in making the foams of the present invention are the dihydrooxidiazinones, as taught in my United States Patent Number 4,097,425, dated June 27, 1978 and assigned to the same assignee as the present invention. In instances where the foamable blend can be pelletized to concentrates having from about 1% to 25% by weight or more of the blowing agent based on the total weight of blend, it can be further melt extruded with additional dihaloalkylene polycarbonate to make the thermoplastic foam of the present invention.
In addition to the above described dihydrooxi-diazinones, other blowing agents which can be used in com-bination with the dihaloalkylene polycarbonate are, for example, 5-phenyltetrazole and diisopropylhydrazodicar-boxylate. In addition to convention blowing agents, foaming l~g9~0 of the dihaloalkylene polycarbonate can be achieved by direct use of inert gases, such as nitrogen by a procedure described by Angel patent 3,436,446. Injection molding of the dihaloalkylene polycarbonates of the present inven-tion can be performed by standard techniques. The afore-mentioned blowing agents or other conventional means of blowing to produce shaped foam structures at temperatures in the range of between 470F to 650E. Included by the shaped foam structures having flame retardant properties which can be melt extruded are, for example, computer housing parts, electrical appliances, business machine housings, automobile roof tops, food handling equipment, furniture parts, etc.
In order that those skilled in the art will be better able to practice the invention, the following examples are given by way of illustration and not by way of limitation. A11 parts are by weight.
Example 1.
A mixture of 26.25 parts of 1,1-dichloro-2,2-bis(4-hydroxyphenyl)ethylene, .026 part of sodium gluconate, 0.237 part of phenol, 0.142 part of triethylamine, 123 parts of methylene chloride and about 75 parts of water is stirred for about 10 109~C~50 minutes at a temperature of about 28C. There is then added to the mixture, an aqueous sodium hydroxide solution in an amount to adjust the pH of the aqueous phase of the mixture to approximately 10.
While the mixture is being thoroughly agitated, phosgene is introduced at a rate of about 12.24 parts per hour while a 20~ aqueous sodium hydroxide solution is added in an amount sufficient to maintain the pH of the aqueous phase of the mixture at 10. Phosgenation of the mixture is continued for about 3/4 of an hour under these conditions and then the rate of phosgenation is reduced to about 6.8 parts per hour while maintaining the pH of the ! aqueous phase to a range of about 11 to 11.5. The phosgen-ation of the mixture is then continued for about 50 minutes.
The above reaction mixture is then diluted with about 100 parts of methylene chloride, and washed alterna-tively with dilute hydrochloric acid, dilute sodium hydroxide and water. The mixture is then centrifuged and filtered and thereafter steam precipitated. There is obtained 26 pounds of product after the precipitate is recovered and dried at 80C. Based on method of pre-paration, the product is l,l-dichloro-2,2-bis(4-hydroxy-phenyl)ethylene polycarbonate having an intrinsic viscosity 1~9~50 of 0.51 dl/gm in chloroform at 25C.
The above described dichloroethylene polycarbon-ate is blended with 5-phenyl-3,6-dihydro-1,3,4-oxidiazin-2-one and glass fiber to produce a blend having .5% by weight of blowing agent and 5~ by weight of glass fiber. The mixture is then melt extruded into pellets at 500F.
In accordance with ASTM-E-162-67, 6" x 18" x 1/4"
test panels are prepared by foam molding the above blend from the above described pellets at 575F. This material has a Gardner Impact Value of about 25-37.5 ft-lb, an intrinsic --viscosity of 0.34 dl/gm, and a density of about 1.07. Equi-valent test panels are also prepared from a blend of the above described dichloroethylene polycarbonate and 5~ by weight of glass fiber free of blowing agent. The test panels are then used in evaluating the flame retardant properties of the glass filled dichloroethylene polycarbonate and the rigid foam derived therefrom in accordance with ASTM-E-162-67.
It is found that the unfoamed test panel has an Is value of 0 which is equivalentto asbestos. The foamed panel is found to have an Is value of 0.8 indicating the foaming of the original dichloroethylene polycarbonate glass fiber blend does not significantly reduce the flame retardant properties of the original blend.
1~99~
Example 2 A blend is prepared of about equal parts by weight of the dichloroethylene polycarbonate of Example 1 and a Bisphenol-A polycarbonate having an intrinsic viscosity of about 0.55 dl/g in chloroform at 25C, along with 5% by weight of the total of glass fiber and 0.5% by weight of the blow-ing agent of Example 1. The blend is melt extruded into pellets at 500F. Pellets are also prepared from the same blend free of blowing agent.
A 6" x 18" test panel is prepared following the procedure of Example 1 by foam molding the blend at 600F.
The foamed blend has an Is value of 3.9 which is substan-tially equivalent to the 3.7 value for the unfoamed blend.
The foamed blend also has an intrinsic viscosity of about 0.45 dl/g in chIoroform at 25C, a Gardner Impact Value greater than 50 ft-lb and a density of about 1.
Example 3.
A blend is prepared of 20 parts of the dichloro-ethylene polycarbbnate of Example 1 and 80 parts of the Bisphenol-A polycarbonate of Example 2 along with 5% by weight of the total of glass fiber.
A melt of the above blend is processed at 575F
in the extruder of a Springfield Case structural foam mold-ing machine using nltrogen gas at 1500 psig. The melt is injected in about 0.08 sec. in a 6" x 18" x 1/4" cavity ~(~9~50 maintained at about 200F. A 75 sec. cycle cool down time is required. There is obtained a 6" x 18" x 1/4" foam test panel having an Is value of 6 which is substantially the same as the Is value of the unfoamed blend. The density of the foam is 1.05; it has an intrinsic viscosity of 0.51 and a Gardner Impact of greater than 75.
Example 4 A blend of 75 parts of the dichloroethylene polycarbonate of Example 1 and 25 parts of an ABS resin is pelletized at 500F with .5~ by weight of the blend of the blowing agent of Example 1, and 5% by weight of glass fiber.
r~est panels are prepared by foam molding the blend at 575F. A comparison of Is values between foamed and unfoamed 6" x 18" x 1/4" test panels in accordance with ASTM-E-162-67 shows a 12.0 for the unfoamed panel and a 12.5 for the foamed panel.
Example 5.
A mixture of 1,1-dichloro-2,2-bis(4-hydroxy-phenyl)ethylene and 2,2-bis(4-hydroxyphenol)propane (Bisphenol-A) is phosgenated in accordance with the pro-cedures of Example 1. There is used 13.12 parts of the dichloroethylene bisphenol and 10.65 parts of Bisphenol-A.
There is obtained a copolymer consisting essentially of chemically co~bined dichloroethylene bisphenol units and Bisphenol-A units.
1CS99~50 The above-described copolymer is pelletized with 5-phenyl-3,6-dihydro-1,3,4-oxidiazin-2-one and glass fiber as in Example 1.
It is found that the Is value of the unfoamed panel is 3.8 while the foamed panel has an I of 4Ø
Although the above examples are limited to only a few of the very many shaped foamed articles which can be made in accordance with the practice of the present inven-tion, it should be understood that the materials used in making such foams can vary widely with respect to the nature of the haloethylene polycarbonate, the thermoplastic polymer used in combination thereof, or the copolymer having chemically combined units of formula 1 and units of the formula, o -O-Z-O-C-where Z is as previously defined. In addition, the means for converting such thermoplastic material under melt foaming conditions also can vary widely based on the nature of the foaming agent employed, such as an oxadiazin-one, inert gas, etc.
Claims (8)
1. Shaped flame retardant rigid thermoplastic foams having a density of from 0.5 g/cc to 1.2 g/cc and a Gardner Impact Strength of at least 10 ft-lbs, which is the product obtained by injection foam molding the melt of a blend comprising by weight (A) from 5-100% of a thermoplastic haloethylene polycarbonate having an intrinsic viscosity of at least 0.35 dl/g and consisting essentially of chemically combined units of the formula and correspondingly (s) from 95-0% of a thermoplastic polycarbonate, where R and R1 are divalent aromatic radicals having from 6-13 carbon atoms, X is a halogen atom, and X1 is selected from X
and hydrogen.
and hydrogen.
2. An article in accordance with claim 1, where the polycarbonate of (A) consists essentially of dichloroethylene bisphenol units.
3. An article in accordance with claim 1, where the polycarbonate of (B) consists essentially of chemically combined isopropylidine bisphenol units.
4. An article in accordance with claim 1, having up to 60% by weight of glass fiber.
5. An article in accordance with claim 1, comprising up to 100% by weight of haloethylene polycarbonate.
6. Shaped flame retardant rigid thermoplastic foams having a density of from 0.5 g/cc to 1.2 g/cc and a Gardner Impact Strength of at least 10 ft-lbs, which is the product obtained by injection foam molding the melt of a thermoplastic copolymer comprising at least 5 mole percent of a thermoplastic haloethylene polycarbonate having an intrinsic viscosity of at least 0.35 dl/g and consisting essentially of units of the formula chemically combined with up to 95 mole percent of bisphenol units of the formula where R and R1 are divalent aromatic radicals having from 6-13 carbon atoms, X is a halogen atom, X1 is selected from the class consisting of X and hydrogen, and Z is selected from the class consisting of R2 and R2-Q-R2, R2 is selected from R radicals and Q is selected from the class consisting of , divalent cycloaliphatic radicals, oxyaryleneoxy radicals, sulfonyl, sulfinyl, oxy, thio, fluoroenyl, phenolphthalein, and R3 is selected from the class consisting of C(1-8) alkyl, R, and halogenated derivatives.
7. An article in accordance with claim 6, where the copolymer consists essentially of chemically combined dihalo-ethylene bisphenol units and isopropylidene bisphenol units.
8. An article in accordance with claim 6, having up to 60% by weight of glass fiber.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US66902776A | 1976-03-22 | 1976-03-22 | |
| US669,027 | 1976-03-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1099050A true CA1099050A (en) | 1981-04-07 |
Family
ID=24684723
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA273,065A Expired CA1099050A (en) | 1976-03-22 | 1977-03-03 | Flame retardant rigid thermoplastic foams |
Country Status (14)
| Country | Link |
|---|---|
| JP (1) | JPS52128963A (en) |
| AU (1) | AU509145B2 (en) |
| BE (1) | BE852748A (en) |
| BR (1) | BR7701716A (en) |
| CA (1) | CA1099050A (en) |
| DD (1) | DD129919A5 (en) |
| DE (1) | DE2709473A1 (en) |
| FR (1) | FR2345480A1 (en) |
| GB (1) | GB1563965A (en) |
| IN (1) | IN144565B (en) |
| IT (1) | IT1075582B (en) |
| MX (1) | MX145502A (en) |
| NL (1) | NL7703065A (en) |
| PL (1) | PL103081B1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4544677A (en) * | 1984-04-10 | 1985-10-01 | General Electric Company | Foamable polycarbonate compositions, articles and methods |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2400086A1 (en) * | 1973-01-02 | 1974-07-04 | Gen Electric | FOAMABLE POLYCARBONATE RESIN |
| GB1562616A (en) * | 1975-08-28 | 1980-03-12 | Gen Electric | Thermoplastic blends |
-
1977
- 1977-02-24 AU AU22636/77A patent/AU509145B2/en not_active Expired
- 1977-02-25 GB GB8174/77A patent/GB1563965A/en not_active Expired
- 1977-02-28 IN IN286/CAL/1977A patent/IN144565B/en unknown
- 1977-03-03 CA CA273,065A patent/CA1099050A/en not_active Expired
- 1977-03-04 DE DE19772709473 patent/DE2709473A1/en not_active Withdrawn
- 1977-03-17 BR BR7701716A patent/BR7701716A/en unknown
- 1977-03-21 DD DD7700197953A patent/DD129919A5/en unknown
- 1977-03-21 NL NL7703065A patent/NL7703065A/en not_active Application Discontinuation
- 1977-03-21 IT IT21440/77A patent/IT1075582B/en active
- 1977-03-21 FR FR7708374A patent/FR2345480A1/en active Granted
- 1977-03-22 MX MX168463A patent/MX145502A/en unknown
- 1977-03-22 PL PL1977196824A patent/PL103081B1/en unknown
- 1977-03-22 JP JP3052677A patent/JPS52128963A/en active Pending
- 1977-03-22 BE BE176008A patent/BE852748A/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| GB1563965A (en) | 1980-04-02 |
| IT1075582B (en) | 1985-04-22 |
| FR2345480B1 (en) | 1983-10-28 |
| JPS52128963A (en) | 1977-10-28 |
| AU509145B2 (en) | 1980-04-24 |
| AU2263677A (en) | 1978-08-31 |
| DE2709473A1 (en) | 1977-10-06 |
| DD129919A5 (en) | 1978-02-15 |
| BE852748A (en) | 1977-07-18 |
| NL7703065A (en) | 1977-09-26 |
| FR2345480A1 (en) | 1977-10-21 |
| BR7701716A (en) | 1977-11-08 |
| PL103081B1 (en) | 1979-05-31 |
| MX145502A (en) | 1982-02-26 |
| IN144565B (en) | 1978-05-13 |
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