CA1059270A - Flame-retardant polyester fiber compositions - Google Patents

Abstract

ABSTRACT

Flame-retardant polyester fibers containing about 5 to 30% by weight of a two-component flame-retardant additive consisting essentially of (a) certain aryl spirophosphates and (b) certain polychlorinated or polybrominated diaryl compounds, the fibers being particularly suitable for preparation of flame-retardant fiber blends, especially blends with cellulose fibers.

Description

lLo~3Z~70 Thls invention relates to flame-retardant polyester fiber compositions. More particularly, this invention relates to flame-retardant polyester fibers whlch are particularly suited for use in making flame retardant blends, especially blends with cellulose fibers such as rayon.
Polyester compositions containing organic phosphorus and organic halogen compounds are known and are dis-closed, for example, in U.S. Patents 3,356,631 issued December 5, 1971, to Jackson et al; 3,645,962 issued February 29, 1972, to Schwarz; 3,681,281 issued August 1, 1972, to Juelke et al; 3,68&,001 issued August 29, 1972, to Exner et al; 3,708,328 issued January 2, 1973, to Kelkheim et al, West German Patent No. 2,001,125 (1970) to Caldwell et al (Eastman Kodak Company), and U.S. Patent 3,658,634 issued April 25, 1972, to Yanagi et al. The aforesaid patents deal with various methods and additives for imparting flame retardance to poly-esters. These exemplary prior art compositions have a 20 number of disadvantages in that they are either uneconom- , ical for commercial use, or the additive is not compat-ible with molten polyester or is reactive with it, or the desired degree of flame retardancy is not obtained at suitable levels of concentration. It has always been desirable to provide efficient, but compatible flame-retardant additives which can be successfully incorporated into the molten polyester prior to the formation of fibers. Moreover, a particular problem in the art has been successfully providing flame-30 retardant polyester fibers which, when blended with ; , - . :
' ~ -sa~b~

other fibers, retain their flame retardant characteristics and impart to the finished fiber blend a high degree of flame retardancy.
According to the present invention, there are provlded flame-retardant polyester fiber compositions comprising from about 95 to 72.2 parts by weight of a fiber-forming linear polyester and about 5 to 27.8 parts by weight of a two-component flame-retardant additive consisting essentially of, by weight:
(a) from about 20 to 80% of an aryl spirophosphate of the formula:

~,~ / CH2 \ ~CH2~ ~ .~' /~ /\ /\
R10 ' CH2 CH2 OR2 wherein Rl and R2 represent aryl radicals selected from the group consisting of phenyl and naphthyl radicals and phenyl and naphthyl radicals containing 1 to 4 chlorine or bromine atoms and substituted derivatives of said radicals, the substituents being selected from the group consisting of lower alkyl, lower alkoxy, phenyl, phenoxy, and phenyl or phenoxy containing 1 to 5 chlorine or bromine atoms, and (b) from about 80 to 20% of a polychlorinated or polybrominated diaryl compound containing at least 40% by weight chlorine or bromine and having the general formula:

3 )b~ - ~ Z ~ _ (OR3)b Xa' a wherein X represents chlorine or bromine and a and a' are integers the sum of which is from 3 to 10; b and '~

~05'3'~'70 b' l~preSent ~ero or J; Tl, repre;ents a member :;elected from the group consi,t;;ng of` Cl-C4 alkyl radicals, Cl-C4 acyl radicals uch as acetyl, pherlyl and benzoyl radical- and chlorinated and brominated phenyl and benzoyl radicals; Z represents a direct;
bond or a member selected from the group consisting of oxygen, carbonyldioxy, sulfonyl, Cl-C4 alkylene, phenylene and chlorinated or brominated phenylene, dioxy radicals of the formula -OR40- where R4 is Cl-C4 alkylene, phenylene or chlorinated or brominated phenylene and ether linkages of the formula -CHzO-, -CH20CH2- and -CsH4CH20CH2C6H4~.
The aforesaid two-component flame-retardant additive is thermally stable and provides a degree of flame retardance enabling a polyester treated therewith to pass the more stringent tests. More-over, the additive is inert in molten polyester and can be added to polyester prior to the melt spinning process, and it does not adversely affect the physical properties of the finished polyester fiber. Flame-retardant polyester fiber prepared in accordance with the present invention can be blended with other fibers, preferably other flame-retardant fibers, and the resulting blend will exhibit improved flame retardant characteristics.
The polyesters which are rendered flame retardant in accordance with the present invention, include the fiber-forming linear saturated polyesters derived from saturated aliphatic and aromatic dicarboxylic acids : ' ~ ' ' 1()5~3Z7(3 and saturated diol;.
These fiber-formirllr ;atllrate(l polye;ters are prepared from dicarboxylic acids such as terephthalic acid, isop~lthalic acld, adipic acid, biben%oic acid, 4,4'-dicarboxyphenylmethane, 2,6-naphthalenedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3- or 1,4-cyclohexanedicarboxylic acid and the like. Diols generally employed to prepare the fiber-forming poly-esters are the saturated aliphatic, saturated cyclo-aliphatic or aromatic diols, preferably the lower alkane diols such as ethylene glycol, propylene glycol, and butylene glycol. Other exemplary diols include ethylene diglycol, dimethylolcyclohexane, 1,6-hexane-diol, p-xylylenediol and the like. Particularly preferred are fiber-forming polyesters such as poly (ethyleneterephthalate), poly (ethylene 2,6-naphthalene-dicarboxylate) or poly (1,4-cyclohexylenedimethylene terephthalate) and blends of such polyesters. These fiber--forming polyesters generally have an average 20 molecular weight of at least about 10,000.
As is known in the art, polyester fibers are conventionally prepared by the melt spinning technique wherein molten polyester is extruded under pressure through a spinneret plate having a plurality of small circular openings about 0.009 inch in diameter. The spinning is carried out at a temperature of from about 260 to 300C. for poly (ethylene terephthalate) fibers. ~-The polymeric polyester has been previously prepared either by the batch method or by the continuous poly-merization technique.

/
:~)5~'~70 Thu~i, in view o~ t,he conditions employed in the melt .;pinnlng process, there are a sigrlificant number of problems to be overcome in successfully incorporating an ef'fective flame-retardant additive during melt spinning. The additive must be thermally stable, and it must be both unreactive with and soluble in the molten polyester. In addition, the flame retardant must have a low volatility at spinning ternperatures and should not in any way interfere with the operation of the spinneret. The additive should also have no substantial adverse effect upon the physical properties of the spun fiber.
The two-component flame-retardant additive of the present invention meets all these important criteria and is particularly suitable for use in connection with the melt spinning process for production of polyester fibers and the preparation of blends of ;~
other fibers with such flame-retardant polyester fibers.
The two-component flame-retardant additive of ,`
the present invention consists essentially of, by ~ ;
weight, frorn about 20 to 80% of an aryl spirophosphate and from 80 to 20% by weight of a polychlorinated or poly- ~-brominated diaryl compound containing at least 40%
by weight chlorine or bromine.
The aryl spirophosphates of the present invention may be represented by the formula:

O~ ~O CH2~ ,CH2 O~ ~

RlO O CH2~ CH2 O OR2 wherein Rl and R2 may be phenyl and naphthyl radicals, and phenyl and naphthyl radicals each containing from l to 4 chlorine or bromine atoms. These phenyl, naphthyl or mono-, or di- or trihalogenated phenyl or naphthyl radicals, the halogen being chlorine or bromine, may also contain substituents selected from the group consisting of lower alkyl or alkoxy of 1 to 3 carbon atoms each, phenyl, phenoxy and chlorinated or brominated phenyl or phenoxy and there may be l to 5 chlorine or bromine atoms present in the pheny or phenoxy substituents. It has been found that the Rl or R2 aryl radicals cannot be completely brominated or chlorinated since a loss of stability may occur, but on the other hand, a phenyl or phenoxy substituent attached to an Rl or R2 aryl;can be completely chlorinated or brominated with no adverse effects.
The spirophosphates are generally and preferably symmetrical, but if desired, asymmetrical compounds may be prepared in accordance with known techniques.
Particularly preferred are those aryl spiro-phosphates of the above formula wherein Rl and R2 represent phenyl, naphthyl, mono-, di-or tribromo-phenyl, and mono-, di- or tribromonaphthyl. Preferred embodiments of this group are those spirophosphates wherein Rl and R2 represent phenyl; 4-bromophenyl;
4-chlorophenyl; 2,4-dichlorophenyl; naphthyl; 4-bromo-phenyl; 2,3,4,~-tetrachlorophenyl; 1-bromo-2-naphthyl;
1,6-dibromo-2-naphthyl and 1,3,6-tribromo-2-naphthyl.
Suitable processes for preparing spirophosphates are disclosed, for example, in U.S. Patent No. 3,090,799, l()S~Z70 is;ued May 21, 19~)3 to ~Jahl et al. Thus, (a) pentaerythritol is reacted with a suitable aryl ester of phosphorus oxychloride, or (b) a pentaerythritol ester of phosphorochloridic acid, a spiro compound, is reacted with an aryl compound of the formula ROH
or the sodium salt thereof, the R representing the desired aryl radicals. Other suitable methods of preparation are readily apparent to those skilled in the art.
The second component of the two component flame-retardant additive is a polychlorinated or polybrominated diaryl compound, preferably the latter. These compounds should contain at least 40%, preferably at least 60%
by weight of chlorine or bromine.
Examples of suitable polychlorinated and/or poly-brominated compounds may be shown by the following formulas, I, II and III:

(I) Xa Xa where X represents chlorine or bromine, a and a' are integers, the sum of which is from 3 to l0, preferably 5 to l0. Preferred compounds of this group include octabromobiphenyl, hexabromobiphenyl, decabromobiphenyl and the like;

(II) ~ 7 Xa a' where X, a and a' are as previously described; Z may be oxygen, carbonyldioxy, sulfonyl, Cl-C4 alkylene, phenylene, chlorinated or brominated phenylene, dioxy radicals 7~3 of the formula -OR40- where R4 is Cl-C4 alkylene, phenylene or chlorinated or brominated phenylene and ether linkages of the

2 ' 2C~l2 and -C6H4cH2cH2c6H4-' Particularly preferred compounds of this class include those wherein Z is oxygen as exemplified by the polybrominated diphenyl ethers such as decabromodiphenyl ether and hexabromodiphenyl ether or where Z is an ether linkage as described above:

(III) R30 _ ~ Z~ ~ xa,OR3 wherein X, a, a' and Z are as described previously in formula II and R3 represents Cl-C4 alkyl, Cl-C4 acyl radicals, phenyl and benzoyl radicals and chlorinated and brominated phenyl and benzoyl radicals. A preferred compound of this class is tetra-bromobisphenol A diacetate.
Generally speaking, the total amount of two-component flame-retardant additive which is added to the polyester is from about 5 to 27.8% based on the combined weight of the polyester and additive, that is, 5 to 27.8 parts by weight of additive and 95 to 72.2 parts by weight of polyester. As a representative example, about 27.8 parts by weight of additive -may be added to about 72.2 parts by weight of polyester to provide a fiber composition. These amounts provide the phosphorus, chlorine and bromine levels discussed below. The addition of amounts in excess of about 27.8~ may interfere with the physical properties of the finished fiber as well as with the proper operation of the processing equipment, particularly the spinnerets used in extruding the fiber from the molten mixture of polyester and additive.

The relative amounts of phosphorus and chlorine 105~'~7~
( ~ r' ~ ~ r'(irfl i r'le ~ t, ;~ f ~ (leplr~l(r~l orl the de~rree or flame retard.lnc~y d(.~re(l. In order to pro-duce blends of ~ol~ye:;~er and cellulosic fiber which meet all existing standar(ls for flame retardancy there should be present at)out 1 to 2% by weight of phosphorus in the fiber. At this phosphorus level, chlorine, if present, should be u,ed in an arnount such that the chlorine to phosphorus weight ratio is from 2:1 to 20:1. For the same level of` phosphorus, that is, about 1 to 2~, the amount of bromine will be such that the weight ratio of bromine to phosphorus is between 2.5:1 and 10:1. Of course, chlorine and bromine may both be present and in such a case the chlorine to phosphorus weight ratio will be at the lower end of the aforesaid range, that is, about 2:1 to 10:1 and the bromine to phosphorus weight ratio will be between about 2.5:1 to 10:1. In any event, the polyester fiber should not contain more than about 12% by weight of bromine as a maximum.
The flame-retardant additive of the present in-vention is thermally stable and can be incorporated into the polyester just prior to the melt spinning process. This is a significant advantage in that no additional fiber processing steps are necessary in order to effectively incorporate the flame retardant. Compo-sitions of the present invention are prepared by simply mixing the two-component additive with the polyester prior to melt spinning. The additive may be dry blended with ground polyester resin, it may be mixed into the molten polyester resin or, preferably, a molten stream of flame-retardant additive may be injected in a molten .

105~'~70 stream o~ polyester ~us1 prior l;o the introduction of the polyester into the spinneret.
Compositions of the present invention are particularly suitable for use in the preparation of blends of polyester with other fibers such as cotton, rayon, nylon, acetate, acrylics and the like.
Particularly suitable are blends with cellulosic fibers such as rayon and acetate. Effectively rendering such blends flame retardant is a particular problem in the art, since under current standards the flame retardant qualities rnust be retained after repeated dry cleaning or laundering.
A particular preferred embodiment resides in blends of 10 to 90 parts by weight, preferably 40 to 60 parts by weight, of a flame-retardant polyester fiber prepared in accordance with the present invention with 90 to 10 parts by weight, preferably 60 to 40 parts by weight of flame retardant regenerated cellulose filaments or fibers, as described in U.S. Patent -20 3,455,713 issued July 15, 1969, to Godfrey. In brief, they are regenerated cellulose filaments having dispersed therein from 1 to 25% by weight of a substantially water-insoluble cyclical and/or linear liquid phosphonitrilic polymer having the general formula ~ 0~ ~

tN = P~
~0~
where R and R' are the same or different alkyl or alkenyl radicals having from 1 to 6 carbon atoms and n is an integer of at least 3 and not more than about 20.

~J5~70 These fibers are prepared by incorporating a flame retardant amount of the phosphonitrilic polymer into filament forming viscose, and spinning and regenerating the filament.
The invention is further illustrated by the following examples, which are not to be considered as limitative of its scope. All parts and percentages are by weight based on the total weight of the compo-sition and temperatures are in degrees centigrade unless otherwise stated.

____ .
The Limiting Oxygen Index (LOI) of plaques con-taining poly (ethylene terephthalate) admixed with varying amounts of the two-component flame-retardant additive was determined and demonstrates the degree of flame retardancy.
The plaques were prepared by grinding in a mortar mixtures of poly (ethylene terephthalate) and the flame- ~ -retarda~t additive. On top of a 6" x 6" stainless steel plate (1/32" thick) was placed a 6" x 6" *Tef~on~ coatéd aluminum plate and then a 6" x 6" brass flame 1/32"
thick with a 5-3/4" x 5-3/4" opening. Nine grams of the powdered mixture was spread evenly on the Teflon coated aluminum plate. A woven glass fabric (4-3/8" x 5-3/8") weighing 3.9-4.1 grams was placed over the mixture inside the frame. An additional nine grams of the mixture was spread evenly over the cloth and covered with an identical *Teflon coated aluminum plate and a stainless steel plate. The mold assembly was placed in a hydraulic press previously heated to 275C

*Trade Mark :', - ' " ' "

1(~59'~7~
and the plat,e; were closed gently at a slight pressure for 3 minutes to allow melting, The pressure was in-creased to 5 tons for 1 minute and then released. It was removed from the press, cooled between two large iron plates, and carefully taken apart to remove the glass fiber supported plaques. The plastic composite was cut into 3-1/2" x 1-3/4" sample strips.
The LOI test was made by supporting the sample strip in a U-shaped frame which was mounted in a cylindrical open chamber. Controlled mixtures of oxygen and nitrogen gases were admitted into the base of the chamber and allowed to displace the normal atmosphere. When an equilibrium atmosphere in the chamber was obtained, the sample was ignited with a gas flame by contacting the flame with the top edge of the sample. If the sample failed to ignite, the oxygen ratio of the atmosphere was increased to a level where the flame will just propagate. Conversely, if the sample strip ignited and the flame propagated, the oxygen ratio of the atmosphere was reduced to a level where flame propagation was virtually zero. The LOI was the minimum percentage concentration of the oxygen atmosphere in which the test sample ignited and permitted flame propagation. The LOI test was intro-duced in 1966 (Fennimore et al, Modern Plastics, 43, 141 (1966) and is the basis for ASTM D-2863-70. The apparatus used was the Oxygen Index Flammability Tester (Model JD14) manufactured by MKM Machine Tool Co., Inc.
Various aryl spirophosphates of the formula 3o l9~

o~p,O --- CH2 ,CH2~ O , RO O - CE~2 CH2--- o OR
were combined with octabromobiphenyl and poly (ethylene terephthalate) to prepare plaques containing the indicated amounts in percent by weight of phosphorus and bromine as shown in Table I (b) below. The LOI
of these plaques was determined. Comparative LOI
data are also shown in Table I (a) for plaques prepared containing only spirophosphate.
Table 1 (a) S~iro~ho_~hate Alone 5a~1e ~o. R %P LOI
__ ___ ___ __ _ 1 C6H5 2 29.0 2 C6H5- 3 29.5

3 C6H5- 2 29.0

4 2 C10 7 2 28.2 Table I (b) - Spirophosphate and Octobromobiphenyl _______ _ _ Sample No. R %P ~Br LOI
___ _ __ 5C6H5- 2 5 32.5 6 C6H5 2 10 34.0 72 ClG 7 1.5 7.5 33.4 -~
It has been found that an LOI greater than 30, preferably about 32 to 36, is desirable for polyesters which are to be blended with cellulosic fibers.

The two-component flame-retardant additive used in 9amples Nos. 5,6 and 7 in this example amounted to 19.5, 25.6 and 21.6 parts by weight respectively of the fiber composition used as starting material in said 9amples ~os. 5,6 and 7.

EXAMPLE II
Example 1 is repeated except that decabromodi-phenyl ether and decachlorobiphenyl were used in place of octabromobiphenyl. The results are tabulated in - .-Tables II (a), II (b), III (a) and III (b).

Table II (a) - S~iro~ho~h~te Alone _ _ _ _ _ _ __ _ __ __ _ _ _ _ _ ___ _ _ _ __ Sample No. R %P LOI
______ _____ ____ ____ _______ 1 C6H5 1 26.3 2 C6~5- 2 29.0 3 4-ClC6H4- 2 29.5 4 4-ClC6H4- 3 30.0 2,4 C12C6H3 2 28.7 6 2, C 2C6 3 7 4-srC6H4- 2 30.0 Table II (b) - Spirophosphate and Decabromodi~henY1 Ether _______________ __ _________~
Sample No. R ~ P % Br LOI
__ _~ ___________ ___ ___ __ 8- C6~5 1.5 7.5 32.0 9 4-ClC6H4- 1.0 10 33.0 4-ClC6H4- 1.5 7.5 33.0 11 2,4-C12C6H3- 1.0 10 34.0 1~ 2-j4-C12C6H3- 1.5 5 31.4 13 4-BrC6H4- 2.0 5 33.0 Table III (a) -_~iro~hosi~hate Alone ________ _ _ __ __ _____ _ __ S mple No. R % P LOI

2 2,3,4,6-C142 29 Table III (b) - Spirophosphate and DecachlorobiPhenYl __ _______ _____ __ __ ____ .
Sam~le No. R ~ P % Cl LOI
___ _~____ ___ __ ~_ ___ 3 C6H5- 2 9.2 31 :
4 ~,3,4,6-C14 2 13.0 30 The two-component flame-retardant additive :
used in Samples Nos. 8,9,10,11,12,13 and 3 in this :~
example amounted to 19.1, 19.9, 20.7, 20.9, 19.4, 24.4 and 26.3 parts by weight respectively of the fiber composition used as starting material in said Samples Nos. 8,9,10,11,12,13 and 3.

.. .

~s~
EXAMPLE III : -:
102.3 grams of poly (ethylene terephthalate) (intrinsic viscosity O.Ç2), 20 grams of the spiro--14a-`~05~ 7V
phosphate of Sample 1, Example I and 18.1 grams of octabromobiphenyl were added to a laboratory spinning apparatus and spun at 280C using a ten hole spinneret.
69 grams of good fiber was collected which contained 1.98% phosphorus and 8.4% bromine. The intrinsic viscosity of the fiber was 0.525 and the tenacity was 2.2 grams/denier. The fiber was drawn (draw ration3.3) and after drawing had a denier of 78. It was three plied with one ply of a flame-retardant regenerated cellulose yarn prepared in accordance with U.S. Patent 3,455,713 containing about 15% by weight of a liquid polymer of di-n-propyl phosphonitrilate dispersed therein and knitted into a sleeve. The sleeve was a 59%/41%
polyester/rayon blend weigh~ng 7.0 ounces per square yard.
Two samples were burned according to United States Department of Commerce (DOC) Standard FF 3-71. In this method, conditioned specimens (dried three hours at 105C), 3-1/2" x 10", are hung vertically one at a time in holders in a prescribed cabinet and subjected to a methane gas flame along the edge for 3 seconds under controlled conditions. The char length and residual flame time are measured. The fabric is flame retardant if the average char length of 5 samples does not exceed 7 inches, no individual sample has a char length of 10 inches and no sample has a residual flame time greater than 10 seconds.
The two samples tested gave the following results:
Sam~le After Fl me (sec) Char _ n~th (ln) 10 4.50 210 3.13 The two-component flame-retardant additive used in this example amounted to 27.14 parts by weight of the fiber composition used as starting material.
j, ?

"3~'7~) EXAMPLE_~V
Example III ~as repeated except that 109 grams of poly (ethylene terephthalate) and 22 grams of octa-bromobiphenyl were used. The fiber contained 2.1%
phosphorus and 9.7~ bromine. The fiber was a 3 ply fiber with 1 ply of the same flame-retardant rayon as in Example III and was knitted into a sleeve. The resulting sleeve was a 53%/47% polyester rayon blend weighing 6.8 ounces per square yard.
Five samp'es were burned again according to Sam~leAfter Flame (sec)Char Len~h (in) 1 0 3.31 2 0 3.31 3 0 3.25 4 0 3.19 The two-component flame-retardant additive used in this example amounted to 27.8 parts by weight of the 0 fiber composition used as starting material.
E~AMoeLE V
A mixture of 8 pounds poly (ethylene terephthalate), 1.33 pounds of the spirophosphate of Sample 1, Example I, and 0.66 pounds decabromodiphenyl ether was prepared and spun in pilot equipment at 285. The resulting fiber contained 2% P and 5% Br by weight. It had a tenacity of 3.1 g/den; elongation was 23%. The fiber was texturized, chopped, carded with the same rayon used in Example III and spun into a 50/50 polyester rayon yarn. A 4 ounce/square yard fabric was knitted from the yarn and burned according to DOC FF 3-71. The average char length of five samples was 6.41 inches, none burned ten inches.
The two-component flame-retardant additive used in this example amounted to 27.8 parts by weight o~ the fiber composition used as starting material.

~s~ v EXAMPLE VI

Another poly (ethylene terephthalate) fiber was pre-pared as in Example V above and contained 2~ P and 10% Br.
The fiber was blended with the same rayon as in Example V into a 50/50 yarn from which 3, 5 and 7 ounce/square yard fabrics were made. Five samples of each fabric were burned before and after fifty launderings by the DOC FF 3-71 test. All samples passed; none burned ten inches.
AVERAGE CHAR LENGTH (IN) 3 oz 5 oz. 7 oz.

Unlaundered 5.8 4.8 3.5 50 Launderings6.3 6.4 1.6 The two-component flame-retardant additive used in this example amounted to 25.4 parts by weight of the fiber composition used as starting material.
SUPPLEMENTARY DISCLOSURE

It has now been found that the range of fiber-forming linear polyester may be extended to a lower figure of about ~ ~
70 parts by weight of polyester while the range of the two- .
component flame-retardant may be extended to a higher figure of about 30 parts by weight of flame-retardant.
Thus, the invention as claimed herein is also a flame-retardant polyester fiber composition comprising from about 95 to 70 parts by weight of a fiber-forming linear polyester and about 5 to 30 parts by weight of a two-component flame-retardant additive consisting essentially of, by weight (a) from about 20 to 80~ of an aryl spirophosphate of the formula ~ / ~ f \ /
R10 CH2/ CH2 _ 0/

~ 17 -,., . . .

wherein Rl and R2 represent aryl radicals selected from -the group consisting of phenyl and naphthyl radicals and phenyl and naphthyl radicals containing 1 to 4 chlorine or bromine atoms and further substituted derivatives of said radicals, the substituents being selected from the group consisting of lower alkyl, lower alkoxy, phenyl, phenoxy, and phenyl or phonoxy containing 1 to 5 chlorine or bromine atoms~ and (b) from about 80 to 20% of a polychlorinated or polybrominated diaryl compound containing at least 40% by weight chlorine or bromine and having the general formula (R30)b'~Z4~(0R3)b Xa' wherein X represents chlorine or bromine and a and a' are integers the sum of which is from 3 to 10; b and b' represent zero or 1;
and R3 represents a member selected from the group consisting of C1-C4 alkyl radicals, Cl-C4 acyl radicals, phenyl and benzoyl radicals; chlorinated and brominated phenyl and benzoyl radicals;
Z represents a direct bond or a member selected from the group consisting of oxygen, carbonyldioxy, sulfonyl, Cl-C4 alkylene, phenylene and chlorinated or brominated phenylene, dioxy radicals of the formula -OR40- wherein R4 is Cl-C4 alkylene, phenylene or chlorinated or brominated phenylene and ether linkages of the formula CH20 , CH2 CH2 n 6 4 2 2 6 4 In this extended range, the substituents Rl and R2 may again represent a member selected from the group consisting of phenyl, naphthyl and mono-, di-, tri- and tetra-chloro and -bromo substituted phenyl and naphthyl radicals. The polyester may be a member of the group consisting of poly (ethylene tere-phthalate), poly (1,4-cyclohexylenedimethylene terephthalate) and ~ ~ .

7~
poly (ethylene 2,6-naphthalenedicarboxylate).
The invention as claimed herein is furthermore a flame-retardant yarn or fabric characterized by a combination of the flame-retardant polyester fiber compositior defined immediately above and a member of the group consisting of cotton, rayon, nylon, acetate and acrylic fibers.
The yarn or fabric may contain rayon in the form of a regenerated cellulose fiber having dispersed therein a flame retardant amount of a water-insoluble, liquid phosphonitrilate polymer of the formula ~
OR \

O n where R and R' are the same or difference alkyl or alkenyl radicals having 1 to 6 carbon atoms and n is an integer of at least 3.
The flame-retardant polyester fiber composition may be such that there is present from about 72.2 to 70 parts by weight of fiber-forming linear polyester and about 27.8 to 30 parts by weight of the two-component flame-retardant additive.
The flame-retardant yarn or fabric may likewise be such that from about 72.2 to 70 parts by weight of polyester and about 27.8 to 30 parts by weight of flame-retardant additive are present in the polyester fiber composition.
The invention as claimed herein is additionally a flame-retardant polyester composition comprising from about 95 to 70 parts by weight of a fiber-forming linear saturated polyester selected from the group consisting of poly (ethylene terephthalate) and poly (ethylene 2,6-naphthalenedicarboxylate), and about 5 to 30 parts by weight of a two-component flame-retardant additive consisting essentially of, by weight, ~ - 19 -

5~77~

(a) from about 20 to 80% of an aryl spirophosphate of the formula Q~ O CH2 ~ ~CH2 \p~
/\ / \ /\
RlO O- -CH2 CH OR2 wherein Rl and R2 represent a member selected from the group consisting of phenyl, naphthyl; mono-, di-, tri-, and tetra-halo substituted phenyl and mono-, di and trichloro substituted naphthyl radicals, and (b) from 80 to 20% of a polychlorinated or polybrominated diaryl compound containing at least 40% by weight chlorine or bromine and having the general formula Xa Xa' wherein X represents chlorine and bromine and a and a' are whole integers the sum of which is from 3 to 10; and Z represents a direct bond or a member selected from the group of oxygen and ether linkages of the formula, -CH2O-, -CH2OCH2- and It is preferred that the substituent X represents bromine, the symbol Z represents a direct bond and the sum of a and a' is from 8 to 10. The polyester composition defined in the preceding paragraph may be used in a flame-retardant yarn or fabric comprising a combination of the flame-retardant polyester composi-tion and rayon, wherein the rayon is a regenerated cellulose fiber having dispersed therein a flame-retardant amount of a water-insoluble, liquid phosphonitrilate polymer of the formula ~ = P/~
\ OR) ~ ~ n where R and R' are the same or different alkyl or alkentlradicals having 1 to 6 carbon atoms and n is an integer of at least 3.

-' 20 '~
, - ..,-:,,": ...
:- -. :,,, , ,., ,, -

Claims (36)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A flame-retardant polyester fiber composition com-prising from about 95 to 72.2 parts by weight of a fiber-forming linear polyester and about 5 to 27.8 parts by weight of a two-component flame-retardant additive consisting essentially of, by weight:
(a) from about 20 to 80% of an aryl spirophosphate of the formula wherein R1 and R2 represent aryl radicals selected from the group consisting of phenyl and naphthyl radicals and phenyl and naphthyl radicals containing 1 to 4 chlorine or bromine atoms and further substituted derivatives of said radicals, the substituents being selected from the group consisting of lower alkyl, lower alkoxy, phenyl, phenoxy, and phenyl or phenoxy containing 1 to 5 chlorine or bromine atoms, and (b) from about 80 to 20% of a polychlorinated or poly-brominated diaryl compound containing at least 40% by weight chlorine or bromine and having the general formula wherein X represents chlorine or bromine and a and a' are integers the sum of which is from 3 to 10; b and b' represent zero or 1;
and R3 represents a member selected from the group consisting of C1-C4 alkyl radicals, C1-C4 acyl radicals, phenyl and benzoyl radicals; chlorinated and brominated phenyl and benzoyl radicals;

Z represents a direct bond or a member selected from the group consisting of oxygen, carbonyldioxy, sulfonyl, C1-C4 alkylene, phenylene and chlorinated or brominated phenylene, dioxy radicals of the formula -OR4O- wherein R4 is C1-C4 alkylene, phenylene or chlorinated or brominated phenylene and ether linkages of the formula -CH2O-, -CH2OCH2- and -C6H4CH2OCH2C6H4-.

2. The composition of claim 1 characterized in that R1 and R2 represent a member selected from the group consisting of phenyl, naphthyl and mono-, di-, tri- and tetra-chloro and -bromo substituted phenyl and naphthyl radicals.

3. The composition of claim 1 characterized in that X
represents bromine.

4. The composition of claim 3 characterized in that Z
represents a direct bond and b and b' are zero.

5. The composition of claim 4 characterized in that the sum of a and a' is from 8 to 10.

6. The composition of claim 3 characterized in that Z
represents a member of the group of oxygen and ether linkages of the formula -CH2O-, -CH2OCH2- and -C6H4CH2OCH2C6H4-.

7. The composition of claim 1 characterized in that the polyester is a member of the group consisting of poly (ethylene terephthalate), poly (1,4-cyclohexylenedimethylene terephthalate) and poly (ethylene 2,6-naphthalenedicarboxylate).

8. A flame-retardant yarn or fabric characterized by a combination of the flame retardant polyester fiber of claim 1 and a member of the group consisting of cotton, rayon, nylon, acetate and acrylic fibers.

9. The composition of claim 8 wherein said rayon is a regenerated cellulose fiber having dispersed therein a flame retardant amount of a water-insoluble, liquid phosphonitrilate polymer of the formula wherein R and R' are the same or different alkyl or alkenyl radicals having 1 to 6 carbon atoms and n is an integer of at least 3.

10. The composition of claim 1, 2 or 7 characterized in that from about 95 to 75 parts by weight of fiber-forming linear polyester and about 5 to 25 parts by weight of the two-component flame-retardant additive are present.

11. The flame-retardant yarn or fabric of claim 8 or 9 characterized in that from about 95 to 75 parts by weight of polyester and about 5 to 25 parts by weight of additive are present in the polyester fiber.

12. A flame-retardant polyester composition comprising from about 95 to 72.2 parts by weight of a fiber-forming linear saturated polyester selected from the group consisting of poly (ethylene terephthalate) and poly (ethylene 2,6-naphthalenedi-carboxylate), and about 5 to 27.8 parts by weight of a two-component flame-retardant additive consisting essentially of, by weight:
(a) from about 20 to 80% of an aryl spirophosphate of the formula wherein R1 and R2 represent a member selected from the group consisting of phenyl, naphthyl; mono-, di-, tri-, and tetra-halo substituted phenyl and mono-, di and trichloro substituted naphthyl radicals, and (b) from 80 to 20% of a polychlorinated or polybrominated diaryl compound containing at least 40% by weight chlorine or bromine and having the general formula wherein X represents chlorine or bromine and a and a' are whole integers the sum of which is from 3 to 10; and Z represents a direct bond or a member selected from the group of oxygen and ether linkages of the formula, -CH2O-, -CH2OCH2- and -C6H4CH2OCH2C6H4-.

13. The composition of claim 12 wherein X represents bromine.

14. The composition of claim 13 wherein Z represents a direct bond and the sum of a and a' is from 8 to 10.

15. A flame-retardant yarn or fabric comprising a combination of the flame-retardant polyester fiber of claim 12 and rayon, wherein said rayon is a regenerated cellulose fiber having dispersed therein a flame-retardant amount of a water-insoluble, liquid phosphonitrilate polymer of the formula wherein R and R' are the same or different alkyl or alkenyl radicals having 1 to 6 carbon atoms and n is an integer of at least 3.

16. A fiber formed from the composition of claim 12.

17. A molded article formed from the composition of claim 12.

18. The composition of claim 13 which contains one to two percent by weight phosphorus and the bromine to phosphorus weight ratio will be between about 2.5:1 and 10:1.

19. The composition of claim 12 wherein both R1 and R2 are 2 - naphthyl and the polybrominated diaryl moiety is octa-bromobiphenyl.

20. The composition of claim 12 wherein both R1 and R2 and 4 - bromophenyl and the polybrominated diaryl moiety is decabromodiphenyl ether.

21. The composition of claim 12 wherein both R1 and R2 are phenyl and the polybrominated diaryl moiety is one of octa-bromobiphenyl, decabromodiphenyl ether and decachlorobiphenyl.

22. The composition of claim 12, 13 or 14 wherein from about 95 to 75 parts by weight of polyester and about 5 to 25 parts by weight of additive are present.

23. The flame-retardant yarn or fabric of claim 15 wherein from about 95 to 75 parts by weight of polyester and about 5 to 25 parts by weight of additive are present in the polyester fiber.

CLAIMS SUPPORTED BY THE SUPPLEMENTARY DISCLOSURE

24. A flame-retardant polyester fiber composition comprising from about 95 to 70 parts by weight of a fiber-forming linear polyester and about 5 to 30 parts by weight of a two-component flame-retardant additive consisting essentially of, by weight:
(a) from about 20 to 80% of an aryl spirophosphate of the formula wherein R1 and R2 represent aryl radicals selected from the group consisting of phenyl and naphthyl radicals and phenyl and naphthyl radicals containing 1 to 4 chlorine or bromine atoms and further substituted derivatives of said radicals, the substituents being selected from the group consisting of lower alkyl, lower alkoxy, phenyl, phenoxy, and phenyl or phenoxy containing 1 to 5 chlorine or bromine atoms, and (b) from about 80 to 20% of a polychlorinated or poly-brominated diaryl compound containing at least 40% by weight chlorine or bromine and having the general formula wherein X represents chlorine or bromine and a and a' are integers the sum of which is from 3 to 10; b and b' represent zero or 1; and R3 represents a member selected from the group consisting of C1-C4 alkyl radicals, C1-C4 acyl radicals, phenyl and benzoyl radicals; chlorinated and brominated phenyl and benzoyl radicals; Z represents a direct bond or a member selected from the group consisting of oxygen, carbonyldioxy, sulfonyl, C1-C4 alkylene, phenylene and chlorinated or brominated phenyl-lene, dioxy radicals of the formula -OR4O- wherein R4 is C1-C4 alkylene, phenylene or chlorinated or brominated phenylene and ether linkages of the formula -CH2O-, -CH2OCH2- and -C6H4CH2OCH2C6H4-.

25. The composition of claim 24 characterized in that R1 and R2 represent a member selected from the group consisting of phenyl, naphthyl and mono-, di-, tri- and tetra-chloro and -bromo substituted phenyl and naphthyl radicals.

26. The composition of claim 24 characterized in that the polyester is a member of the group consisting of poly (ethylene terephthalate), poly (1,4-cyclohexylenedimethylene terephthalate) and poly (ethylene 2,6-naphthalenedicarboxylate).

27. A flame-retardant yarn or fabric characterized by a combination of the flame retardant polyester fiber of claim 24 and a member of the group consisting of cotton, rayon, nylon, acetate and acrylic fibers.

28. The composition of claim 27 wherein said rayon is a regenerated cellulose fiber having dispersed therein a flame retardant amount of a water-insoluble, liquid phosphonitrilate polymer of the formula wherein R and R' are the same or different alkyl or alkenyl radicals having 1 to 6 carbon atoms and n is an integer of at least 3.

29. The composition of claim 24, 25 or 26 characterized in that from about 72.2 to 70 parts by weight of fiber-forming linear polyester and about 27.8 to 30 parts by weight of the two-component flame-retardant additive are present.

30. The flame-retardant yarn or fabric of claim 27 or 28 characterized in that from about 72.2 to 70 parts by weight of polyester and about 27.8 to 30 parts by weight of additive are present in the polyester fiber.

31. A flame-retardant polyester composition comprising from about 95 to 70 parts by weight of a fiber-forming linear saturated polyester selected from the group consisting of poly (ethylene terephthalate) and poly (ethylene 2,6-naphthalenedi-carboxylate), and about 5 to 30 parts by weight of a two-component flame-retardant additive consisting essentially of, by weight:
(a) from about 20 to 80% of an aryl spirophosphate of the formula wherein R1 and R2 represent a member selected from the group consisting of phenyl, naphthyl; mono-, di-, tri-, and tetra-halo substituted phenyl and mono-, di and trichloro substituted naphthyl radicals, and (b) from 80 to 20% of a polychlorinated or polybrominate diaryl compound containing at least 40% by weight chlorine or bromine and having the general formula wherein X represents chlorine or bromine and a and a' are whole integers the sum of which is from 3 to 10; and Z represents a direct bond or a member selected from the group of oxygen and ether linkages of the formula, -CH2O-, -CH2OCH2- and -C6H4CH2OCH2C6H4-.

32. The composition of claim 31 wherein X represents bromine.

33. The composition of claim 32 wherein Z represents a direct bond and the sum of a and a' is from 8 to 10.

34. A flame-retardant yarn or fabric comprising a combination of the flame retardant polyester fiber of claim 31 and rayon, wherein said rayon is a regenerated cellulose fiber having dispersed therein a flame-retardant amount of a water-insoluble, liquid phosphonitrilate polymer of the formula wherein R and R' are the same or different alkyl or alkenyl radicals having 1 to 6 carbon atoms and n is an integer of at least 3.

35. The composition of claim 31, 32 or 33 wherein from about 72.2 to 70 parts by weight of polyester and about 27.8 to 30 parts by weight of additive are present.

36. The flame-retardant yarn or fabric of claim 34 wherein from about 72.2 to 70 parts by weight of polyester and about 27.8 to 30 parts by weight of additive are present in the polyester fiber.