Title of Invention

PROCESS FOR MANUFACTURE OF PENTAERYTHRITOL DIPHOSPHITES

Abstract A method is disclosed for the production of pentaerythritol diphosphites of high spiro isomer content. The pentaerythritol diphosphites are produced via sequential transesterification of pentaerythritol with a monophosphite followed by a substituted phenol or other alcohol, wherein the transesterification reactions are carried out under controlled conditions of temperature and pressure. The unique reaction conditions result in intermediate and final pentaerythritol diphosphites of high spiro isomer content and high total yield of the diphosphites.
Full Text PROCESS FOR MANUFACTURE OF PENTAERYTHRITOL DIPHOSPHITES
Technical Field
The present invention is directed to a process for the manufacture of spiro
pentaerythritol diphosphites. More specifically, the present invention is directed to a
process for the manufacture of pentaerythrhol diphosphites via transesterification under
vacuum to produce a diphosphite with high spiro isomer content.
Background of the Invention
Various organic phosphites are known to be effective as polymer additives and are
effective as stabilizers against thermooxidative degradation of polymers during processing.
In particular, pentaerythritol diphosphites are used in applications where their improved
hydrolytic stability and enhanced compatibility with some polymers such as polyolefins
makes these compounds especially desirable as polymer stabilizers.
Pentaerythritpl diphosghjtes comprise at least two isomeric forms, the spiro and
caged isomers. The commercial desirability of the spiro isomer over the caged isomer is
well known. It is, therefore, desirable to produce pentaerythritol diphosphites having high
spiro isomer content.
Generally, pentaerythritol diphosphites can be prepared by at least two different
methods. In one method, two sequential transesterification reactions are performed, first, °
the reaction of pentaerythritol with triphenyl phosphite to make diphenyl pentaerythritol
diphosphite, and second, the reaction of the intermediate diphenyl pentaerythritol
diphosphite with the appropriate alkylphenol or alcohol to produce the desired
pentaerythritol diphosphite. In another method, dichloropentaerythritol diphosphite is
reacted with the appropriate alkylphenol or alcohol to produce the desired pentaerythritol
diphosphite. The latter method is said to produce a bis(alkylphenyl) pentaerythritol
diphosphite with a negligible portion of caged isomer but involves more complex and
expensive processing technology. The former transesterification method is cheaper to
implement but generally produces mixtures of isomers having a spiro isomer content of
from 50 percent upon to 75 percent depending on the method of preparation and the
reactants. Thus bis(alkylphenyl) pentaerythritol diphosphite prepared via transesterification
typically are mixtures of spiro and caged isomers that must be further purified by selective
crystallization in order to produce a predominantly spiro product. Such an approach,
however, inherently leads to a relatively low yield.

One approach to improving the spiro isomer content of bis (2,4-di-t-butylphenyl)
pentaerythritol dlphosphite produced via transesterification is to react diphenyl
pentaerythritol diphosphite (DPPEDP) with 2,4-di-t-butylphenol in a Cio-C16 n-alkane or
cycloalkane solvent. This method gives a product with a spiro isomer content of up to 90
percent, but the diphosphite yield is relatively low at about 77 percent.
An economically more favorable and thus desirable transesterification process would
be one which produces a bis(alkylphenyl) pentaerythritol diphosphite with a spiro isomer
content of at least 90 percent, and with a high diphosphite yield of at least 95 percent.
Summary of the Invention
It is therefore an object of the present invention to provide a method for the
production of pentaerythritol diphosphites via transesterification chemistry having a high
spiro isomer content and high yield.
In general, the present invention provides a process for producing bis(alkylphenyl)
pentaerythritol diphosphites with high spiro isomer content greater than 90 percent via
transesterification chemistry with yields greater than 95 percent. The process of this
invention comprises conventional transesterification reactions where the increase in the
spiro isomer content and yield results from: (1) unique reaction conditions used to produce
an intermediate product and the final product that minimize competing reaction products;
and (2) the use of distillation to concentrate the diphosphite content of the intermediate and
final products.
Accordingly, it is an object of the present invention to disclose a sequence of
transesterification reactions which maximize the spiro content of a pentaerythritol
diphosphite.
It is another object of the present invention to effect the above sequence of
transesterification reactions in a preferred embodiment using pentaerythritol and triphenyl
phosphite to form an intermediate pentaerythritol diphosphite followed by a second
transesterification reaction with a substituted phenol or lower alcohol to produce a high
spiro content pentaerythritol diphosphite.
These and other objects of the present invention will become more readily apparent
from a reading of the following detailed description and with further reference to the
appended claims.

Detailed Description of the Invention
The process of the present invention involves sequential transesterification reactions
to provide an intermediate and final reaction product. The first reaction is the
transesterification of pentaerythritol (formula I)

with a monophosphite in the presence of an alkaline catalyst. The monophosphite can be
selected from the group of triaryl phosphites, e.g., tripheny! phosphite (formula II)

ortrialkyl phosphites, e.g., trimethyl phosphite, or triethylphosphite. More generically, a
trialkyl or triaryl phosphite may be shown as P-(OR1)3 wherein R1 is selected from the
group consisting straight-chain or branched alkyl groups, cycloaliphatic groups which may
have substituents, straight-chain or branched alkenyl groups, unsubstituted oralkyl-
substituted aryl groups and arylalkyl groups.
Specific non-limiting examples of straight-chain or branched alkyl groups are C1.20
,alkyls, e.g., methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl,
dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl and stearyi
groups.
Specific non-limiting examples of the cycloaliphatic or cyclic alkyl groups which may
have substituents are cycloalkyl groups having 5 to 7 carbon atoms such as cyclopentyl,
cyclohexyl and cycloheptyl groups, and the alkylcycloalkyl groups having 6 to 11 carbon
atoms wherein the position of the alkyl group may vary, such as methylcyclopentyi,
dimethylcyclopentyl, methylethylcyclopentyl, dimethylcyclopentyl, methylcyclohexyl,
dimethylcyclohexyl, methylethylcyclohexyl, diethylcyclohexyl, methylcycloheptyl,
dimethylcycloheptyl, methylcycloheptyl, and diethylcycloheptyl groups.
Specific non-limiting examples of the straight-chain or branched alkenyl groups are
those having 2 to 30 carbon atoms wherein the position of the double bond may vary, such
as butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl,

tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, and octadecenyl
groups.
Specific examples of the unsubstituted or alkyl-substituted aryl groups are the aryl
groups having 6 to 18 carbon atoms such as phenyl, diphenyl and naphthyl groups, and
alkylaryl groups having 7 to 40 carbon atoms wherein the alkyl group may be straight-chain
or branched and may be bonded to any position on the aryl group, such as tolyl, xylyl,
ethylphenyl, propylphenyl, butylphenyl, pentylphenyl, hexylphenyl, heptylphenyl,
octylphenyl, nonylphenyl, decylphenyl, undecylphenyl, dodecylphenyl, diethylphenyl,
dibutylphenyl and dioctylphenyl groups. The alkylaryl groups may additionally have
substituents including functional groups such as alkoxy, hydroxy, cyano, nitro, halides,
carboxylic acids, etc.
Specific examples of the arylalkyl groups are those having 7 to 40 carbon atoms
wherein the alkyl group may be straight-chain or branched, such as benzyl, phenylethyl,
phenylpropyl, phenylbutyl, phenylpentyl and phenylhexyl groups.
This first transesterification results in the production of an intermediate
pentaerythritol diphosphite reaction product having spiro isomer shown in the following
base formula (III):
wherein R1 is as previously defined and caged isomer shown in the following formula (IV):
In a preferred embodiment, pentaerythritol is transesterified with triphenyl phosphite
to produce the intermediate diphenyl pentaerythritol diphosphite shown in the following
formula (V):
The second reaction is the transesterification of the intermediate pentaerythritoi
diphosphite with an alcohol, R2—OH wherein the alcohol is selected from the group
consisting of Ca-22 alkanols, Cs-22 alkenols, phenols and derivatives thereof, C7-40 alkylaryl

phenols and derivatives thereof and C7-40 arylalkyl phenols and derivatives thereof, wherein
said derivatives are chemical moieties selected from the group consisting of halogens, Cw
alkyls, CM alkoxy compounds, amino groups, C^ carboxylic acid groups, cyano groups,
nitro groups, etc., in the presence of an alkaline catalyst to produce a pentaerythritol
diphosphite of the following formula (VI):

where R2 is preferably selected from the group consisting of 2,4-di-t-butylphenyl, 2,4-
dicumylphenyl, and lower Cs - C20 alkanes, e.g., stearyl, isodecyl and decyl derived
preferably from alcohols are selected preferably from the group consisting of 2,4-di-t-
butylphenol, 2,4-dicumylphenol of formula (VII),

and more generically as described previously.
In a preferred embodiment, in the second transesterification reaction, the diphenyl
pentaerythritol diphosphite intermediate from the first transesterification reaction of this
invention is transesterified with 2,4-dicumylphenol in the presence of an alkaline catalyst to
produce bis(2,4-dicumylphenyl) pentaerythritol diphosphite with high yield and a high spiro
isomer content as shown in the following formula (VIII):

In preparing a reaction mixture for the first esterification reaction, monophosphite
and pentaerythritol are used in a ratio of approximately 1 to 3 moles of monophosphite per
mole of pentaerythritol. In the preferred embodiment of the first transesterification reaction,
a stoichiometric amount of 2 moles monophosphite per mole of pentaerythritol is used. A
solvent may be used in the reaction mixture to reduce the viscosity, aid reactivity and/or to
enable subsequent purification via fractional crystallization of the reaction mixture.
Therefore, a solvent is not required and is thus optional. When employed, solvents that
can be used include aromatic, aliphatic, and cyclic hydrocarbons in the C6 to C24 range.
Suitable solvents are normal or cyclic paraffins. More particularly, the solvent will be a
saturated hydrocarbon or mixture of saturated hydrocarbons selected from the group
consisting of C6- C24 n-alkanes and cyclo-alkanes. Representative examples of suitable
hydrocarbons are n-decane, n-dodecane, n-tridecane, n-hexadecane and the like, and the
cyclic and polycyclic analogs such as cyclododecane, bicyclo[4,4,0]decane
(decahydronaphthalene) and the like. Often, the solvent will be a solvent mixture and
include lower alkanes, e.g., hexane, heptane and cyclohexane. Unsaturated solvents are
also useful in the invention, e.g., benzene and toluene. Solvents, if used in the reaction
mixture are used in an amount ranging from about 10 weight percent up to about 200
weight percent based on the weight of intermediate pentaerythritol diphosphite produced.
An alkaline catalyst is also used in the first esterification reaction. The alkaline
catalyst is preferably an alkaline inorganic compound and most preferably is an alkali or
alkaline earth metal oxide, hydroxide, carbonate or alcoholate, all of which are catalysts
well-known in the art as being useful for these purposes. The alkaline catalyst is used in
the reaction mixture in an amount ranging from about 0.1 weight percent to about 5 weight
percent, based on the weight of intermediate pentaerythritol diphosphite produced.
The first transesterification reaction is carried out under controlled conditions of
temperature and pressure. In a preferred embodiment of the first transesterification, the
reaction is carried out at atmospheric pressure. The reaction can also be carried out under
vacuum (full vacuum to about 200 mm Hg) with liberated phenol removed via distillation.
The temperature of the first reaction is in a range of between about 60°C and a final
temperature of below 125°C, preferably between 70°C to about 105°C. At these
temperatures the formation of undesirable side reaction products is minimized and
correspondingly the yield of pentaerythritol diphosphite is maximized.

While not wishing to be bound to any particular theory, it is believed that the
stoichiometry and low temperature of the first transesterification reaction at atmospheric
pressure selectively promotes the formation of the spiro and caged isomers of the
intermediate diphenyl pentaerythritol diphosphite at the expense of other undesirable side
reaction products. The transesterification byproduct is separated from any residual
reactants, and side reaction products by distillation or by fractional crystallization of the
diphosphite in solvent. This unique processing results in the combined weight of the spiro
and caged isomers of the intermediate pentaerythritol diphosphite representing a yield of
greater than 95%, based on the monophosphite reactant.
In a preferred embodiment of the first transesterification reaction, phenol is produced
by the transesterification of pentaerythritol and triphenyl phosphite in the presence of
alkaline catalyst to form diphenyl pentaerythritol diphosphite as the intermediate
pentaerythritol diphosphite. The liberated phenol, any unreacted monophosphite and any
side reaction products are removed by distillation. The distillation is performed with a
temperature in the range of about 100°C to about 300°C, and a pressure of about full
vacuum to about 200 mm Hg. The phenol byproduct and monophosphite reactants are of
high quality and can be used as raw material for other reactions. The side reaction
components can be recycled into subsequent first transesterification reactions as they
rearrange to spiro and caged pentaerythritol diphosphites.
Other methods of purification of the first reaction mixture include fractional
crystallization in solvent and fractional melt crystallization. If the reaction is run in solvent,
the same solvent used for dilution of the reaction mixture can be used for the fractional
crystallization of the pentaerythritol diphosphites.
Following the first transesterification reaction, the purified intermediate
pentaerythritol diphosphite produced is used in a second transesterification reaction to form
a second pentaerythritol diphosphite. In preparing the second transesterification reaction
mixture, a substituted phenol or alcohol and the intermediate pentaerythritol diphosphite
are used in amounts ranging from approximately stoichiometric to an excess of about 300
weight percent of the stoichiometric amount of the substituted phenol or alcohol. The
substituted phenol (or alcohol in excess, if used) is used to reduce the viscosity of the
second reaction mixture and to bias the reaction to completion. In the preferred
embodiment, the substituted phenol is 2,4-dicumyl phenol or 2,4-di-t-butyl phenol. Thus,
when a substituted phenol is used, the second pentaerythritol diphosphite formed during

the second transesterification reaction can be a bis(substituted phenol) pentaerythritol
diphosphite.
A solvent may be used in the reaction mixture to reduce viscosity, aid reactivity,
and/or to enable subsequent reaction mass purification via fractional crystallization. But a
solvent is not required and is thus optional. Solvents that can be used include aromatic,
aliphatic, and cyclic hydrocarbons in the 6-24 carbon range. Normal or cyclic paraffins are
suitable solvents. More particularly, the solvent will be a saturated hydrocarbon or mixture
of saturated hydrocarbons selected from a group consisting of 6 to 24 carbon n-alkanes
and cyclo-alkanes. Representative examples of suitable hydrocarbons are n-decane, n-
dodecane, n-tridecane, n-hexadecane and the like; and the cyclic and polycyclic analogs
such as cyclododecane, bicyclo[4,4,0]decane (decahydronaphthalene) and the like. Often,
the solvent will be a solvent mixture and inolude lower alkanes, e.g., hexane, heptane, and
cyclohexane. Unsaturated solvents are also useful in the invention, e.g., benzene, toluene
and the like. Solvents if used in the reaction mixture, are used in an amount ranging from
about 10 weight percent to about 200 weight percent based on the weight of pentaerythritol
diphosphite produced.
An alkaline catalyst is also used in the second esterification reaction. The alkaline
catalyst is preferably an alkaline inorganic compound and most preferably is an alkali or
alkaline earth metal oxide, hydroxide, carbonate, alcoholate, all of which are catalysts well-
known in the art as being useful for these purposes. The alkaline catalyst is used in the
second reaction mixture in an amount ranging from about 0.1 weight percent to about 5
weight percent, based on the weight of the second pentaerythritol diphosphite produced.
The second transesterification reaction is carried out under controlled conditions of
temperature and pressure. The temperature of the second reaction mixture is maintained
in a range of about 120°C to below 175°C, preferably 120°C to 170°C and preferably is
maintained at about 150°C. The reaction is performed under vacuum to give a pressure in
the range of about full vacuum to about 200 mm Hg absolute. In the preferred
embodiment, phenol Is produced by the transesterification of diphenyl pentaerythritol
diphosphite intermediate and 2,4-dicumyl phenol to form bis(2,4-dicumylphenyl)
pentaerythritol diphosphite as the second pentaerythritol diphosphite. The byproduct
phenol that is liberated during the second transesterification reaction is removed by
distillation. The phenol byproduct is of high quality and can be used as raw material for
other reactions.

While not wishing to be bound by a particular theory, it is believed that the
stoichiometry, removal of byproduct phenol during the second transesterification reaction,
along with the high purity of the pentaerythritol diphosphite, selectively promotes the
formation of the spiro isomer of the second pentaerythritol diphosphite at the expense of
the caged isomer. The unique reaction conditions during the second transesterification
reaction, along with those of the first transesterification reaction result in a spiro isomer
content greater than 90% of the combined total weight of the spiro and caged isomers of
the second pentaerythritol diphosphite produced in the second transesterification reaction.
The total combined weight of the spiro and caged isomers of the second pentaerythritol
diphosphite represents a yield of greater than 95%, based on the intermediate
pentaerythritol diphosphite reactant.
Following the second transesterification reaction, the second pentaerythritol
diphosphite produced is separated form the second reaction mixture via distillation. In the
preferred embodiment, the second reaction mixture is distilled to remove any unreacted
materials, excess substituted phenol (or alcohol if used), solvent (if used), and/or any
residual phenol to leave a purified second pentaerythritol diphosphite that is preferably 99%
by weight of spiro and caged isomers of the second pentaerythritol diphosphite, based on
the total weight of the second pentaerythritol diphosphite and residual impurities. The
distillation is performed with a temperature in the range of about 100°C to about 300°C, and
a pressure of about full vacuum to about 200 mm Hg absolute. In a preferred embodiment,
the second pentaerythritol diphosphite is bis(2,4-dicumylphenyl) pentaerythritol diphosphite.
Other methods of purification of the second reaction mass include fractional
crystallization and fractional melt crystallization. If solvent crystallization is used to purify
the second transesterification reaction mass, the same solvent used for dilution of the
reaction mass can be used for the crystallization fractionation process. Solvents that can
be used include aromatic, aliphatic, and cyclic hydrocarbons in the 6 to 24 carbon range.
Normal or cyclic paraffins are suitable solvents. More particularly, the solvent will be a
saturated hydrocarbon or mixture of saturated hydrocarbons selected from a group
consisting of 6 to 24 carbon n-alkanes and cycloalkanes. Representative examples of
suitable hydrocarbons are n-decane, n-dodecane, n-tridecane, n-hexadecane and the like;
and the cyclic and polycyclic analogs such as cyclododecane, bicyclo[4,4,0]decane
(decahydronaphthalene) and the like. Often, the solvent will be solvent mixture and
include lower alkanes, e.g., hexane and cyclohexane. Unsaturated solvents are also useful

in the invention, e.g., benzene, toluene and the like. Solvents if used in the reaction
mixture, are used in an amount ranging from about 10 weight percent up to about 200
weight percent based on the weight of pentaerythritol diphosphite produced.
Examples
The best mode for carrying out the invention will now be described for the purposes
of illustrating the best mode known to the applicant at the time. The examples are
illustrative only and not meant to limit the invention, as measured by the scope and spirit of
the claims.
Example 1: Preparation of Bis-2,4-Dicumyl Pentaerythritol Diphosphite
The transesterification reaction of monopentaerythritol and triphenylphosphite (TPP)
is carried out with stoichiometric amounts of TPP and pentaerythritol with a solvent in the
presence of an alkaline catalyst at temperatures beginning at 70°C and ending at less than
125°C, preferably 105-120cC at atmospheric pressure. Phenol produced during the
reaction is removed through vacuum distillation at from 100-300°C and pressures ranging
between 0.01 and 100 mm Hg absolute with greater than 95% of theory recovered and less
than 5% remaining in the reaction mass. Unreacted materials remain in this intermediate
product at a level typically below 1 %, preferably below 0.1 %. The phenol byproduct is of
high rtiality and can be used as a raw material in other reactions. Surprisingly, under these
cond.:i jns, the spiro isomer of DPPEDP is produced in preference to the caged isomer and
DPPEDP yields are greater than 95% based on TPP. Solvent is not essential to the
reaction chemistry serving only to reduce viscosity and thus is optional. Solvents that can
be used include various aromatic hydrocarbons and hydrocarbon solvents in the 6 to 20
carbon range. Alkaline catalyst loading is 0.01-5% by weight of DPPEDP produced.
Solvent, if used, can be added to the reaction system in the amount of 10-200% by weight
of DPPEDP produced. The reaction scheme and operating parameters produce a reaction
crude with DPPEDP with a spiro content of greater than 90%, solvent if used, along with
trace amounts of TPP, phenol, and caged isomer of DPPEDP.
The purified high spiro DPPEDP is stable and can be stored molten or solidified or
sold as an intermediate product. The stripped TPP, trace phenol and/or solvent is recycled
into subsequent DPPEDP production. The next step is to transesterify the high spiro
DPPEDP with 2,4-dicumyl phenol to produce high spiro bis-2,4-dicumyl pentaerythritol
diphosphite.

High spiro DPPEDP form the previous reaction is added to alkaline catalyzed 2,4-
dicumyl phenol at about 150°C. The alkaline catalyst level is 0.1-5% by weight of bis-2,4-
dicumyl. pentaerythritol diphosphite produced. The reactants can be added in amounts
ranging from stoichiometric (2 moles 2,4-dicumyl phenol to 1 mole diphenyl pentaerythritol
diphosphite) to large stoichiometric excesses (300% or more to reduce viscosity) of 2,4-
dicumyl phenol. A vacuum of 0.01 to 100 mm Hg absolute is maintained to distill the phenol
produced in the transesterification reaction to trace levels. The reaction produces bis-2,4-
dicumyl pentaerythritol diphosphite that has a spiro isomer content of greater than 90% with
phosphite yields (based on DPPEDP) of greater than 95%. The phenol byproduct is of
high quality and can be used as a raw material in other processes.
The reaction mass is then stripped via thin film distillation at 150-300°C and 0.01 to
50 mm Hg absolute to remove the excess 2,4-dicumyl phenol to levels below 0.5%. The
resulting products is greater than 90% spiro bis-2,4-dicumylphenyl pentaerythritol
diphosphite that can be pastilled, pelletized, or flaked, etc., to the desired product form The
distilled 2,4-dicumyl phenol and trace phenol is recycled to subsequent reactions. By
employing the reaction parameters described above, the final diphosphite reaction product
may be used without the need to resort to recrystallization purification.
The high spiro isomer content pentaerythritol diphosphites made by the methods of
the current invention may be used to stabilize any of the polymers known in the art, such as
polyoiefins, polyesters, polyurethanes, polyalkylene terephthalates, polysulfones,
polyimides, polyphenylene ethers, styrenic polymers, polycarbonates, acrylic polymers,
polyamides, polyacetals, halide containing polymers and polyolefin homopolymers and
copolymers. Additionally included would be mixtures of different polymers, such as
polyphenylene ether/styrenic resin blends, polyvinylchloride/ABS or other impact modified
polymers, such as methacrylonitrile containing ABS, and polyester/ABS or polyester plus
some other impact modifier may also be used. Such polymers are available commercially
or may be made by means well known in the art. However, the diphosphites of the
invention are particularly useful in thermoplastic polymers, such as polyoiefins,
polycarbonates, polyesters, polyphenylene ethers thermoplastic polymers, such as
polyoiefins, polycarbonates, polyesters, polyphenylene ethers and styrenic polymers, due
to the extreme temperatures at which the thermoplastic polymers are often processed
and/or used.

Polymers of monoolefins and diolefins, for example would include polypropylene,
polyisobutylene, polybutene-1, polymethylpentene-1, polyisoprene or polybutadiene, as
well as polymers of cycloolefins, for instance of cyclopentene or norbornene, polyethylene
(which optionally can be crosslinked), for example high density polyethylene (HDPE), low
density polyethylene (LDPE) and linear low density polyethylene (LLDPE) may be used.
Mixtures of these polymers, for example mixtures of polypropylene with polyisobutylene,
polypropylene with polyethylene (for example PP/HDPE), may also be used. Also useful
are copolymers of monoolefins and diolefins with each other or with other vinyl monomers,
such as, for example, ethylene/propylene, LLDPE and its mixtures with LDPE,
propylene/butene-1, ethylene/hexene, ethylene/ethylpentene, ethylene/heptene,
ethylene/octene, propylene/butadiene, isobutylene/isoprene, ethylene/alkyl acrylates,
ethylene/alkyl methacrylates, ethylene/vinyl acetate (EVA) or ethylene/acrylic acid
copolymers (EAA) and their salts (ionomers) and terpolymers of ethylene with propylene
and a diene, such as hexadiene, dicyclopentadiene or ethylidene-norbornene; as well as
mixtures of such copolymers and their mixtures with polymers mentioned above, for
example polypropylene/ethylene-propylene copolymers, LDPE/EVA, LDPE/EAA,
LLDPE/EVA and LLDPE/EAA.
Thermoplastic polymers may also include styrenic polymers, such as polystyrene,
poly-(p-methylstyrene), poly-(ar-methylstyrene), copolymers of styrene, p-methylstyrene or
alpha-methylstyrene with dienes or acrylic derivatives, such as, for example,
styrene/butadiene, styrene/acrylonitrile, styrene/alkyl methacrylate, styrene/maleic
anhydride, styrene/butadiene/ethyl acrylate, styrene/acrylonitrile/methacrylate; mixtures of
high impact strength from styrene copolymers and another polymer, such as, for example,
from a polyacrylate, a diene polymer or an ethylene/propylene/diene terpolymer; and block
copolymers of styrene, such as, for example, styrene/butadiene/styrene,
styrene/isoprene/styrene, styrene/ethylene/butylene/styrene or
styrene/ethylene/propylene/styrene. Styrenic polymers may additionally or alternatively
include graft copolymers of styrene or alpha-methylstyrene such as, for example, styrene
on polybutadiene, styrene on polybutadiene-styrene or polybutadiene-acrylonitrile; styrene
and acrylonitrile (or methacrylonitrile) on polybutadiene; styrene and maleic anhydride or
maleimide on polybutadiene; styrene, acrylonitrile and maleic anhydride or maleimide on
polybutadiene; styrene, acrylonitrile and methyl methacrylate on polybutadiene, styrene
and alkyl acrylates or methacrylates on polybutadiene, styrene and acrylonitrile on

ethylene/propylene/diene terpolymers, styrene and acrylonitrile on polyacrylates or
polymethacrylates, styrene and acrylonitrile on acrylate/butadiene copolymers, as well as
mixtures of the styrenic copolymers indicated above.
Nitrile polymers are also useful. These include homopolymers and copolymers of
acrylonitrile and its analogs such as methacrylonitrile, such as polyacrylonitrile,
acrylonitrile/butadiene polymers, acrylonitrile/alkyl acrylate polymers, acrylonitrile/alkyl
methacrylate/butadiene polymers, acrylonitrile/butadiene/styrene (ABS), and ABS which
includes methacrylonitrile.
Polymers based on acrylic acids, such as acrylic acid, methacrylic acid, methyl
methacrylate acid and ethacrylic acid and esters thereof may also be used. Such polymers
include polymethylmethacrylate, and ABS-type graft copolymers wherein all or part of the
acrylonitrile-type monomer has been replaced by an acrylic acid ester or an acrylic acid
•amide. Polymers including other acrylic-type monomers, such as acrolein, methacrolein,
acrylamide and methacrylamide may also be used.
Halogen-containing polymers may also be useful. These include resins such as
polychloroprene, epichlorohydrin homopolymers and copolymers, polyvinyl chloride,
polyvinyl bromide, polyvinyl fluoride, polyvinylidene chloride, chlorinated polyethylene,
chlorinated polypropylene, fluorinated polyvinylidene, brominated polyethylene, chlorinated
rubber, vinyl chloride-vinylacetate copolymer, vinyl chloride-ethylene copolymer, vinyl
chloride propylene copolymer, vinyl chloride-styrene copolymer, vinyl chloride-isobutylene
copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-styrene-maleic
anhydride tercopolymer, vinyl chloride-styrene-acrylonitrile copolymer, vinyl chloride-
isoprene copolymer, vinyl chloride-chlorinated propylene copolymer, vinyl chloride-
vinylidene chloride-vinyl acetate tercopolymer, vinyl chloride-acrylic acid ester copolymers,
vinyl chloride-maleic acid ester copolymers, vinyl chloride-methacrylic acid ester
copolymers, vinyl chloride-acrylonitrile copolymer and internally plasticized polyvinyl
chloride.
Other useful thermoplastic polymers include homopolymers and copolymers of cyclic
ethers, such as polyalkylene glycols, polyethylene oxide, polypropylene oxide or
copolymers thereof with bis-glycidyl ethers; polyacetals, such as polyoxymethylene and
those polyoxymethylene which contain ethylene oxide as a comonomer, polyacetals
modified with thermoplastic polyurethanes, acrylates or methacrylonitrile containing ABS;
polyphenylene oxides and sulfides, and mixtures of polyphenyiene oxides with polystyrene

or polyamides; polycarbonates and polyester-carbonates; polysulfones, polyethersulfones
and polyetherketones; and polyesters which are derived from dicarboxylic acid and diols
and/or from hydroxycarboxylic acids or the corresponding lactones, such as polyethylene
terephthalate, polybutylene terephthalate, poly-1,4-dimethyliol-cyclohexane terephthalate,
poly-[2,2,4-(4-hydroxyphenyl)-propane] terephthalate and polyhydroxybenzoates as well as
block copolyetheresters derived from polyethers having hydroxyl end groups.
Polyamides and copolyamides which are derived from diamines and dicarboxylic
acids and/or from aminocarboxylic acids or the corresponding lactams, such as polyamide-
4, polyamide-6, polyamide-6/6, polyamide-6/10, polyamide-6/9, polyamide-6/12, polyamide-
4/6, polyamide-11, polyamide-12, aromatic polyamides obtained by condensation of m-
xylene, diamine and adipic acid; polyamides prepared from hexamethylene diamine and „«#"""
isophthalic and/or terephthalic acid and optionally an elastomer as modifier, for example,
poly-2,4,4-trimethylhexamethylene terephthalamide or poly-m-phenylene isophthalamide
may be useful. Further copolymers of the aforementioned polyamides with polyolefins,
olefin copolymers, ionomers or chemically bonded or grafted elastomers; or with
polyethers, such as for instance, with polyethylene glycol, polypropylene glycol or
polytetramethylene glycols, and polyamides or copolyamides modified with EPDM or ABS
may be used.
The resulting stabilized polymer compositions comprising the phosphites made by
the process of this invention may fcptionally also contain various conventional additives,
such as the following:
(1) Antioxidants
(1.1) Alkylated monophenols, for example: 2,6-dk-butyl-4-methylphenol,
2-f-butyl-4,6-dimethylphenol, 2,6-di-f-butyl-4-ethylphenol, 2,6-di-f-butyl-4-n-butylphenol,
2,6-di-f-butyl-4-butylphenol,2,6-di-cyclopentyl-4-methylphenol,
2-(n-methylcyclohexyl)-4,6-dimethylphenol, 2,6-di-octadecyl-4-methylphenol,
2,4,6-tri-cyclohexylphenol, and 2,6-dk-butyl-4-methoxymethylphenol.
(1.2) Alkylated hydroquinones, for example, 2,6-di-f-buty7l-4-methoxyphenol,
2,5-dk-butyl-hydroquinone, 2,5-di-f-amyl-hydroquinone, and
2,6-diphenyl-4-octadecyloxyphenoI.
(1.3) Hydroxylated thiodiphenyl ethers, for example,
2I2I-thio-bis-(6-f-butyl-4-methylphenol),2,2'-thio-bis-(4-octylphenol),

4,4 (1.4) Alkylidene-blsphenols, for example,
2,2'-methylene-bis-(6-f-buty]-4-methylphenol), 2,2'-methylene-bis-(6-f-butyl-4-ehtylphenol),
2,2I-methylene-bis-[4-methyl-6-(alpha-methylcyclohexyl)phenol],
2,2'-methylene-bis-(4-methyl-6-cyclohexylphenol)I
2,2t-methylene-bis-(6-nonyl-4-methylphenol),
2,2'-methylene-bis-[6-(a-methylbenzyl)-4-nony'phenol],
2,2'-methylene-bis-[6-(a,ff-dimethyIbenzyl)-4-nonyIphenol],
2,2'-methyIene-bis-(4,6-dk-butylphenol), 2,2'-methylene-bis-(4,6-di-f-butylphenol),
4I4'-methylene-bis-(6-f-butyl-2-methy!phenol),
1,1 -bis-(5-f-butyl-4-hydroxy-2-methylphenyl)butane,
2,6-di-(3-/-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenolI
1,1,3-tris-(5-f-butyl-4-hydroxy-2-methylphenyl)butane,
1,1 -bis-(5-f-butyl-4-hydroxy-2-methylphenyl)-3-dodecylmercaptobutane, ethylenglycol-bis-
p.S-bis-CS'-f-butyWhydroxy-phenyO-butyrate],
di-(3-f-butyl-4-hydroxy-5-methylphenyl)-dicyclopentadiene, and
di-[2-(3'-f-butyl-2'-hydroxy-5'methyl-benzyl)-6-f-butyl-4-methylphenyl]terephthalate.
(1.5) Benzyl compounds, for example,
1,3,5-tris-(3,5-di-t-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene,
bis(3,5-di-t-butyl-4-hydroxybenzyl)sulfide,
isooctyl-3,5-di-t-butyl-4-hydroxybenzyl-mercapto-acetate,
bis-(4-t-butyl-3-hydroxy-2,6-dimethylbenzy1)dithiolterephthalate,
1,3,5-tris-(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate,
1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzy1 )isocyanurate,
dioctadecyl-3,5-di-t-butyl-4-hydroxybenzyl-phosphonate, calcium salt of monoethyl
3,5-di-t-butyl-4-hydroxybenzylphosphonate,and
1,3,5-tris-1 .S.S-dicyclohexyW-hydroxybenzyOisocyanurate.
(1.6) Acylaminophenols, for example, 4-hydroxy-lauric acid anilide, 4-hydroxy-
stearic acid anilide, 2,4-bis-octylmercapto-6-(3,5-f-buty1-4-hydroxy-anilino)-s-triazine, and
octyl-N-(3,5-di-f-butyl-4-hydroxyphenyl)-carbanate
(1.7) Esters of Zt-(3,5-di-t-butyl-4-hydroxyphenyl)-propionic acid with monohydric or
polyhydric alcohols, for example, methanol, diethyleneglycol, octadecanol,

triethyleneglycol, 1,6-hexanediol, pentaerythritol, neopentylglycol.tris-hydroxyethyl
isocyanurate, thiodiethyleneglycol, and dihydroxyethyl oxalic acid diamide.
(1.8) Esters of U-(5-t-butyl-4-hydroxy-3-methylphenyl)-propionic acid with
monohydric orpolyhydric alcohols, for example, methanol, diethyleneglycol, octadecanol,
triethyleneglycol, 1 ,6-hexanediol, pentaerythritol, neopentyglycol, tris-hydroxyethyl
isocyanurate, thiodiethyleneglycol, and di-hydroxyethyl oxalic acid diamide.
(1.9) Esters ofJ3-(5-t-butyl-4-hydroxy-3-methylphenyl)propionic acid with mono- or
polyhydric alcohols, e.g. with methanol, diethylene glycol, octadecanol, triethylene glycol,
1,6-hexanediol, pentaerythritol, neopentyl glycol, tris(hydroxyethyl)isocyanurate,
thiodiethylene glycol, and N,N'-bis(hydroxyethyl)oxalic acid diamide.
(1.10) Amides of/?-(3,5-di-t-butyl-4-hydroxyphenyl)-propionic acid, for example,
N,N' N,N'-di-(3,5-di-t-butyl-4-hydroxyphenylpropionyl)-trimethylendiamine, and
N,NI-di-(3,5-di~t~butyl-4-hydroxyphenylpropionyl)..hydrazine
(2) UV absorbers and light stabilizers.
(2.1) 2-(2'-Hydroxyphenyl)-benzotriazoles, for example, the 5'-methyl-, 3\5'-di-t-
butyl-,5'-t-butyl-, 5'-(1,1,3,3-tetramethylbutyl)-, S-chloro-S'.S-di-t-butyl-, S-chloro-S'-t-butyl-S1-
methyl-, 3'-sec-butyl-5'-t-butyl-, 4'-octoxy, 3',5'-di-t-amyl-, and 3',5'-bis-( a,cKiimethylbenzyl)-
derivatives.
(2.2) 2-Hydroxy-benzophenones, for example, the 4-hydroxy-, 4-methoxy-, 4-
octoxy-, 4-decyloxy-, 4-dodecyloxy-, 4-benzyloxy-, 4,2',4'-trihydroxy- and 2l-hydroxy-4,4l-
dimethoxyderivatives.
(2.3) Esters of substituted and unsubstituted benzoic acids, for example, phenyl
salicylate, 4-f-butyi-phenylsalicilate, octylphenyl salicylate, dibenzoylresorcinol,
bis-(4-f-butylbenzoyl)-resorcinol, benzoylresorcinol,
2,4-di-f-butyl-phenyl-3,5-di-f-butyl-4-hydroxybenzoate and
hexadecyl-3,5-di-f-butyl-4-hydroxybenzoate.
(2.4) Acrylates, for example, o-cyano-^-diphenylacrylic acid ethyl ester or isooctyl
ester, a-carbomethoxy-cinnamic acid methyl ester, a-cyano-iff-methyl-p-methoxy-cinnamic
acid methyl ester or butyl ester, a-carbomethoxy-p-methoxy-cinnamic acid methyl ester,
andN-0ff-carbomethoxyTff-cyano-vinyl)-2-methyl-indoline.
(2.5) Nickel compounds, for example, nickel complexes of

2,2'-thio-bis-[4-(1 f 1,3,3-tetramethyIbutyl)-phenoI], such as the 1:1 or 1:2 complex, optionally
with additional ligands such as n-butylamine, triethanolamine or N-cyclohexyl-di-
ethanolamine, nickel dibutyldithiocarbamate, nickel salts of 4-hydroxy-3,5-di-t-
butylbenzylphosphonic acid monoalkyl esters, such as of the methyl, ethyl or butyl ester,
nickel complexes of ketoximes such as of 2-hydroxy-4-methyl-pentyi undecyl ketoxime, and
nickel complexes of 1-phenyl-4-lauroyl-5-hydroxy-pyrazol, optionally with additional ligands.
(2.6) Stericaliy hindered amines, for example bis-(2,2,6,6-tetramethylpiperidyl)-
sebacate, bis-(1 ^^.e.B-pentamethylpiperidyO-sebacate, n-butyl-3,5-di-t-butyl-4-
hydroxybenzyl malonicacid, bis^i^^.e.e-pentamethylpiperidyljester, condensation
product of i-hydroxyethyl^.e.e-tetramethyM-hydroxy-piperidine and succinic acid,
condensation product of N1N'-(2,2,6,6-tetramethylpiperidyl)-hexamethyIendiamine and 4-t-
octylamino^.e-dichloro-I.S.S-s-triazine.tris^^.e.e-tetramethylpiperidylJ-nitrilotriacetate,
tetrakis^^.B.e-tetramethyW-piperidyl^i^.S^-butane-tetracarbonicacid,
^^-(i^-ethanediyO-bis^.S.S.S-tetramethylpiperazinone). Such amines include
hydroxylamines derived from hindered amines, such as
di-(1 -hydroxy-2,2,6,6-tetramethylpiperidin-4-yl) sebacate;
1-hydroxy-2,2,6,6-tetramethyl-4-benzoxypiperidine;
1-hydroxy-2,2,6,6-tetramethyl-4(3,5-dk-butyl-4-hydroxyhydrocinnamoyloxy)piperidine;and
N-(1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl)-e-caprolactam.
(2.7) Oxalic acid diamides, for example, 4,4'-di-octyloxy-oxanhlide,
2,2l-di-octyloxy-5,5-di-t-butyl-oxanilideI2,2'-di-dodecyloxy-5I5f-di-t-butyl-oxanilide,
2-ethoxy-2'-ethyl-oxanilide, N,Nl-bis(3-dimethylaminopropyl)-oxalamide,
2-ethoxy-5-t-butyl-2'-ethyloxanilide and its mixture with
2-ethoxy-2'-ethyl-5,4'-di-t-butyloxanilide and mixtures of o-methoxy and p-methoxy as well
as of o-ethoxy and p-ethoxy disubstituted oxanilides.
(3) Metal deactivators, for example, N.N'-diphenyloxalic acid diamide,
N-salicylal-N'-salicyloylhydrazine.N.N'-bis-salicyloylhydrazine,
N,N'-bis-(3,5-di-f-butyl-4-hydroxyphenylpropionyl)-hydrazine, salicyloylamino-1,2,4-triazole,
bis-benzyliden-oxalic acid dihydrazide.
(4) Phosphites and phosphonites other than those of the Invention, for example
triphenyl phosphite, diphenylalkyl phosphites, phenyldialkyl phosphites, tris(nonyl-phenyl)

phosphite, trilauryl phosphite, trioctadecyl phosphite, distearyl pentaerythritol diphosphite,
tris(2,4-di-f-butylphenyl)phosphite, diisodecyl pentaerythritol diphosphite, bis(2,4-di-f-
butylphenyl)pentaerythritol diphosphite, tristearyl sorbitol triphosphite, and tetrakis(2,4-di-f-
butylphenyl) 4,4'-biphenylene diphosphonite.
(5) Peroxide scavengers, for example esters of l-thiodipropionic acid, for example the
lauryl, stearyl, myristyl ortridecyl esters, mercaptobenzimidazole or the zinc salt of 2-
mercaptobenzimidazole, zinc-dibutyl-ditbiocarbamate, dioctadecyldisulfide, pentaerythritol-
tetrakis(/9-dodecylmercapto)-propionate.
(6) Polyamide stabilizers, for example copper salts in combination with iodides and/or
phosphorus compounds and salts of divalent manganese.
(7) Basic co-stabilizers, for example, melamine, polyvinylpyrrolidone, dicyandiamide,
triallyl cyanurate, urea derivatives, hydrazine derivatives, amines, polyamides,
polyurethanes, alkali metal salts and alkaline earth metal salts of higher fatty acids for
example calcium stearate, barium stearate, magnesium stearate, sodium ricinoleate,
potassium palmitate, antimony pyrocatecholate and zinc pyrocatecholate.
(8) Nucleating agents, for example, 4-f-butyl-benzoic acid, adipic acid, diphenylacetic
acid.
(9) Fillers and reinforcing agents, for example, calcium carbonate, silicates, glass
fibers, asbestos, talc, kaolin, mica, barium sulfate, metal oxides and hydroxides, carbon
black, graphite.
(10) Amlnoxvpropanoate derivatives such as methyl-3-[N,N-
dibenzylaminoxyjpropanoate;
ethyl-3-[N,N-dibenzylaminoxy]propanoate;
1,6-hexamethylene-bis[3-(N,N-dibenzylaminoxy)propanoate];
methyl-[2-(methyl)-3(N,N-dibenzylaminoxy)propanoate];
octadecyl-3-[N,N-dibenzyl-aminoxy]propanoicacid;tetrakis[(N,N-dibenzylaminoxy)ethyl
carbonyloxymethyl]methane;octadecyl-3-[N,N-diethylaminoxy]propanoate;
3-[N,N-dibenzylaminoxy]propanoicacid potassium salt; and 1,6-hexamethylene
bis[3-(N-allyl-N-dodecylaminoxy)propanoate].
(11) Other additives, for example, plasticizers, lubricants, emulsifiers, pigments, optical
brighteners, flame-proofing agents, anti-static agents, blowing agents and thiosynergists

such as dilaurylthiodipropionate or distearylthiodipropionate.
Hindered phenolic antioxidants may also be present in the polymer composition.
Use of bis(alkylpheny)l pentaerythritol diphosphites of the present invention may result in
enhanced polymer protection by reducing the formation of color resulting from the presence
of the phenols. Such phenolic antioxidants include in addition to those specifically
mentioned previously,
/?-octadecyl-3,5-di-f-butyl-4-hydroxyhydrocinnamate, neopentaneterayl
tetrakis-(3,5-dM-butyl-4-hydroxyl-hydrocinnamate),
di-n-octadecyl-3,5-di-f-butyl-4-hydroxybenzyl-phosphonate,
1,3,5-tris(3,5-di-f-butyl-4-hydroxybenzyl-)isocyanurate,
thiodiethylene-bis(3,5-dk-butyl-4-hydroxyhydrocinnamate),
I.S.S-trimethyl^Ae-tris^.S-di-f-butyM-hydroxybenzyObenzene,
3,6-di-oxaoctamethylenebis(3-methyl-5-f-butyl-4-hydroxyhydrocinnamate),
2,6-di-f-butyl-p-cresol,
2,2'-ethylidene-bis(4,6-dk-butylphenol),
1,3,5-tris-(2,6-di-methyl-4-f-butyl-3-hydroxybenzyl)isocyanurate,
1,1,3-tris-(2-methyl-4-hydroxy-5-f-butylphenyl)butane,
I.S.S-trisP^S.S-di-f-butyM-hydroxyhydrocinnainoloxyJ-ethyll-isocyanurate,
3,5-di-(3,5-di-f-butyl-4-hydroxybenzyl)-mesitol,
hexamethylene-bis(3,5-di-f-butyl-4-hydroxyhydrocimiamate),
1-(3,5-dW-butyl-4-hydroxyanilino)-3,5-di(octylthio)-s-triazine,
N,N'-hexamethylene-bis(3,5-di-f-butyl-4-hydroxyhydro-cinnamamide),
calcium bis(ethyl-3,5-di-f-butyl-4-hydroxybenzylphosphonate),
ethylene bis[3,3-di(3-f-butyl-4-hydroxyphenyl)butyrate],
octylS.S-di-f-butyW-hydroxybenzylmercaptoacetate,
bis(3,5-dk-butyl-4-hydroxyhydrocinnamoyl(hydrazide, and
N,Nl-bis-[2-(3,5-f-butyl-4-hydroxyhydroxocinnamoyloxy)-ethyl]-oxamide,
neopentanetetrayltetrakis(3,5-di-f-butyl-4-hydroxyhydrocinnamate),
/7-octadecyl-3,5-dk-butyl-4-hydroxyhydrocinnamate,
I.S.S-trimethyl^^.e-trisfS.S-di-NbutyM-hydroxy-benzylJbenzene,
1,3,5-tris-(3,5-di-f-butyl-4-hydroxybenzyl)isocyanurate, 2,6-di-f-butyl-p-cresol or
2,2'-ethylidene-bis(4,6-dk-butylphenol).

(12) Lactones, for example, 5,7-di-t-butyl-3-phenyl-3H-benzofuran-2-one; 5,7-di-cumyl-
3-phenyl-3H-benzofuran-2-one; nonyl-e-phenyl-3H-benzofuran-2-one;dinonyl-3-phenyl-3H-
benzofuran-2-one;5-t-butyl-3-phenyl-3H-benzofuran-2-one;5-cumyl-3-phenyl-3H-
benzofuran-2-one; and octyl-3-phenyl-3H-benzofuran-2-one, and other 3-arylbenzofuran-2-
ones.
Other additives, such as oxazaphospholidines, may additionally or alternatively
be present. Likewise, the instant compounds prevent color formation when hindered amine
light stabilizers are present, such hindered amines including
bis(1,2I2,6,6-pentamethyl-4-piperidyl)2-n-butyl-2-(3,5-di-f-butyl-4-hydroxy-benzyl)
malonate; bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate; dimethylsuccinate polymer with
4-hydroxy-2,2,6,6-tetramethyl-1-piperidinethanol; and polymers of 2,4-dichloro-6-
octylamino-s-triazine with N'-(2,2,6,6-tetramethyl-4-piperidyl)hexamethylene diamine.
The invention has been described with reference to preferred and alternate
embodiments. Obviously, modifications and alterations will occur to others upon the
reading and understanding of the specification. It is intended to include all such
modifications and alterations insofar as they come within the scope of the appended claims
or the equivalents thereof.

We Claim:
1. An improved method for synthesizing pentaerythritol diphosphites comprising
the steps of:
(a) transesterifying pentaerythritol of formula (I)

with a monophosphite of formula P-(OR1)3 to form a first reaction mixture
which comprises an intermediate pentaerythritol diphosphite having a
spiro isomer as shown in the following formula (III),

a caged isomer shown in the following formula (IV),

unreacted monophosphite and side reaction products wherein R1 is
selected from the group consisting of straight-chain or branched C1-20 alkyl
groups, C5-7 cycloaliphatic groups and C6-n substituted derivatives thereof,
straight-chain or branched C2-30 alkenyl groups, C6-is aryl groups, C7-40
alkylaryl groups and C7.40 arylalkyl groups and blends thereof;

where R2 is selected from the group consisting of Cs-22 alkyls, Cs-22
alkenyls, phenyl, C7.40 alkylaryls and C7.40 arylalkyls.
(b) removing reaction products other than said intermediate pentaerythritol
diphosphite from said first reaction mixture; and
(c) transesterifying said intermediate pentaerythritol diphosphite with an
alcohol selected from the group consisting of C8-22 alkanols, C8-22 alkenols,
phenols, C7-40 alkylaryl alcohols and C7-40 arylalkyl alcohols to form a
second reaction mixture which comprises a final pentaerythritol
diphosphite of formula (VI)

2. The method as claimed in claim 1 which further comprises the step of
separating said intermediate pentaerythritol diphosphite from said first
reaction mixture to produce a purified intermediate pentaerythritol
diphosphite.
3. The method as claimed in claim 2 wherein said monophosphite is selected
from the group consisting of trimethyl phosphite, triethyl phosphite and
triphenyl phosphite.
4. The method as claimed in claim 3 wherein said monophosphite is triphenyl
phosphite.
5. The method as claimed in claim 4 wherein said intermediate pentaerythritol
diphosphite is diphenyl pentaerythritol diphosphite.
6. The method as claimed in claim 1 wherein a ratio of said monophosphite to
said pentaerythritol is about 2 moles of monophosphite per mole of
pentaerythritol.
7. The method as claimed in claim 1 which further comprises an alkaline catalyst
in said first transesterifying step.
8. The method as claimed in claim 7, wherein said amount of said alkaline
catalyst ranges from about 0.01 weight percent to about 5 weight percent,
based on the intermediate pentaerythritol diphosphite.
9. The method as claimed in claim 1 wherein said alcohol is 2,4-dicumyl phenol.
10. The method as claimed in claim 1, wherein said first transesterification
reaction pressure is in a range from about 0.01 mm Hg to about 100 mm Hg.
11. The method as claimed in claim 10 wherein said first transesterification
reaction temperature is in a range from about 70°C to about 105°C.
12. The method as claimed in claim 11 wherein said first reaction mixture further
comprises a solvent.
13. The method as claimed in claim 12, wherein said solvent is selected from the
group consisting of C6-C2o aromatic hydrocarbons and C6-C20 aliphatic
hydrocarbons and blends thereof.
14. The method as claimed in claim 13, wherein said solvent is added in an
amount ranging from about 10 weight percent to about 200 weight percent of
said intermediate pentaerythritol diphosphite.
15. The method as claimed in claim 11 wherein said intermediate pentaerythritol
diphosphite comprises a spiro isomer content of greater than 90 percent.
16. The method as claimed in claim 15 wherein said intermediate pentaerythritol
diphosphite has a yield of greater than 95 percent, based on the
pentaerythritol.

17. The method as claimed in claim 2 wherein said separating step comprises
distillation of said reaction mixture sufficient to purify said intermediate
pentaerythritol diphosphite to a purity of at least 99 percent.
18. The method as claimed in claim 17 wherein the purity of said intermediate
pentaerythritol diphosphite is at least 99.9 percent.
19. The method as claimed in claim 2 further comprising the step of separating
said second pentaerythritol diphosphite from said second reaction mixture.
20. The method as claimed in claim 19 wherein said step of separating said
second pentaerythritol diphosphite from said second reaction mixture
comprises a step of distillation.
21. The method as claimed in claim 19 wherein said alcohol is selected from the
group consisting of 2,4-di-t-butylphenol and 2,4-dicumylphenol.
22. The method as claimed in claim 21 wherein said alcohol is 2,4-dicumylphenol.
23. The method as claimed in claim 19 wherein said final pentaerythritol
diphosphite is selected from the group consisting of bis(2,4-dicumylphenyl)
pentaerythritol diphosphite and bis (2,4-di-t-butylphenyl) pentaerythritol
diphosphite.
24. The method as claimed in claim 19 wherein a temperature of said second
transesterification reaction is in a range of about 130°C to about 170°C.
25. The method as claimed in claim 24 wherein a pressure said second
transesterification reaction is in a range of about 0.01 mm Hg to about 100
mm Hg.
26. The method as claimed in claim 19, wherein the amount of said alcohol
ranges from about 2 moles to about 8 moles per mole of said intermediate
pentaerythritol diphosphite.
27. The method as claimed in claim 19, which further comprises an alkaline
catalyst said second transesterification reaction.
28. The method as claimed in claim 27, wherein the amount of said alkaline
catalyst is in a range of about 0.01 weight percent to about 5 weight percent,
based on the final pentaerythritol diphosphite.
29. The method as claimed in claim 19, wherein said final pentaerythritol
diphosphite comprises a spiro isomer content of greater than 90 mole
percent.
30. The method as claimed in claim 1 wherein
said monophosphite is triphenyl phosphate of formula (II)


said intermediate reaction mixture comprises diphenyl pentaerythritol diphosphite
of formula (V)
said alcohol is 2,4-dicumylphenol of formula (VII);

said final pentaerythritol diphosphite is bis(2,4-dicumylphenyl) pentaerythritol
diphosphite of formula (VIII)


A method is disclosed for the production of pentaerythritol diphosphites of high spiro isomer content. The pentaerythritol
diphosphites are produced via sequential transesterification of pentaerythritol with a monophosphite followed by a substituted
phenol or other alcohol, wherein the transesterification reactions are carried out under controlled conditions of temperature and pressure.
The unique reaction conditions result in intermediate and final pentaerythritol diphosphites of high spiro isomer content and
high total yield of the diphosphites.

Documents:

01489-kolnp-2006-abstract.pdf

01489-kolnp-2006-asignment.pdf

01489-kolnp-2006-assignment-1.1.pdf

01489-kolnp-2006-claims.pdf

01489-kolnp-2006-correspondence other.pdf

01489-kolnp-2006-correspondence others-1.1.pdf

01489-kolnp-2006-description (complete).pdf

01489-kolnp-2006-form-1.pdf

01489-kolnp-2006-form-3-1.1.pdf

01489-kolnp-2006-form-3.pdf

01489-kolnp-2006-form-5.pdf

01489-kolnp-2006-international publication.pdf

01489-kolnp-2006-international search report.pdf

01489-kolnp-2006-pct form.pdf

01489-kolnp-2006-priority document.pdf

1489-kolnp-2006-assignment.pdf

1489-kolnp-2006-correspondence.pdf

1489-kolnp-2006-examination report.pdf

1489-kolnp-2006-form 18.pdf

1489-kolnp-2006-form 3.pdf

1489-kolnp-2006-form 5.pdf

1489-kolnp-2006-gpa.pdf

1489-kolnp-2006-granted-abstract.pdf

1489-kolnp-2006-granted-claims.pdf

1489-kolnp-2006-granted-description (complete).pdf

1489-kolnp-2006-granted-form 1.pdf

1489-kolnp-2006-granted-specification.pdf

1489-kolnp-2006-others.pdf

1489-kolnp-2006-reply to examination report.pdf


Patent Number 247736
Indian Patent Application Number 1489/KOLNP/2006
PG Journal Number 19/2011
Publication Date 13-May-2011
Grant Date 10-May-2011
Date of Filing 01-Jun-2006
Name of Patentee DOVER CHEMICAL CORPORATION
Applicant Address 3676, DAVIS ROAD, NW DOVER, OH
Inventors:
# Inventor's Name Inventor's Address
1 LARKE, CARROLL 996, MICHALE LANE, ZOAR, OH 44697
PCT International Classification Number C07F9/6574
PCT International Application Number PCT/US2004/039200
PCT International Filing date 2004-11-23
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10/707,402 2003-12-11 U.S.A.