U.S. patent application number 12/331092 was filed with the patent office on 2009-06-11 for primary pvc plasticizers derived from vegetable oils, process for obtaining primary pvc plasticizers derived from vegetable oils and plasticized pvc composition.
This patent application is currently assigned to NEXOLEUM BIODERIVADOS LTDA.. Invention is credited to Jose Augusto De Carvalho, Jacyr Vianna De Quadros Junior.
Application Number | 20090149586 12/331092 |
Document ID | / |
Family ID | 40344406 |
Filed Date | 2009-06-11 |
United States Patent
Application |
20090149586 |
Kind Code |
A1 |
De Quadros Junior; Jacyr Vianna ;
et al. |
June 11, 2009 |
PRIMARY PVC PLASTICIZERS DERIVED FROM VEGETABLE OILS, PROCESS FOR
OBTAINING PRIMARY PVC PLASTICIZERS DERIVED FROM VEGETABLE OILS AND
PLASTICIZED PVC COMPOSITION
Abstract
The present descriptive report refers to a patent of invention
of primary PVC plasticizers composed of epoxidized ethyl and/or
isoamyl esters of vegetable oil fatty acids and to the compounds of
PVC plasticized with epoxidized bioesters, belonging to the
technical field of polymer additives, developed from renewable
sources such as vegetable oils and sugar cane, to reduce the cost
and improve the properties of PVC compounds. The epoxidized
bioesters are suitable to be added to at least one PVC resin and
are obtained from a transesterification reaction of at least one
type of vegetable oil with ethanol or isoamylic alcohol and
subsequent epoxidation, presenting oxirane index equal to or less
than 8. These primary plasticizers provide improvements to the
properties of the compounded PVC not foreseen in the state of the
art, such as better physical properties at low temperatures,
greater flexibility of the final compound, higher mixing efficiency
of the resin, improved resistance to aliphatic solvents extraction
and improved resistance to UV degradation.
Inventors: |
De Quadros Junior; Jacyr
Vianna; (Sao Paulo, BR) ; De Carvalho; Jose
Augusto; (Sao Paulo, BR) |
Correspondence
Address: |
NIXON PEABODY, LLP
401 9TH STREET, NW, SUITE 900
WASHINGTON
DC
20004-2128
US
|
Assignee: |
NEXOLEUM BIODERIVADOS LTDA.
Cotia
BR
|
Family ID: |
40344406 |
Appl. No.: |
12/331092 |
Filed: |
December 9, 2008 |
Current U.S.
Class: |
524/114 ;
549/518; 549/549 |
Current CPC
Class: |
C08K 5/1515 20130101;
C07D 303/42 20130101; C08K 5/04 20130101; C08G 59/32 20130101; C08G
59/027 20130101; C08G 59/1455 20130101; C08K 5/0016 20130101; C11C
3/006 20130101; C08K 5/1515 20130101; C08L 27/06 20130101; C08K
5/04 20130101; C08L 27/06 20130101; C08K 5/0016 20130101; C08L
27/06 20130101 |
Class at
Publication: |
524/114 ;
549/549; 549/518 |
International
Class: |
C08K 5/1515 20060101
C08K005/1515; C07D 303/42 20060101 C07D303/42; C07D 301/03 20060101
C07D301/03 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 10, 2007 |
BR |
PI 0705621-4 |
Claims
1. PRIMARY PVC PLASTICIZERS DERIVED FROM VEGETABLE OILS, comprising
presenting the general formula: ##STR00003## wherein R is selected
randomly from the group of epoxidized oleic, linolenic and linoleic
acid.
2. PRIMARY PVC PLASTICIZERS DERIVED FROM VEGETABLE OILS, according
to claim 1, wherein the fact that said plasticizer is epoxidized
ethyl ester.
3. PRIMARY PVC PLASTICIZERS DERIVED FROM VEGETABLE OILS, according
to claim 2, wherein said plasticizer is epoxidized ethyl
soyate.
4. PRIMARY PVC PLASTICIZERS DERIVED FROM VEGETABLE OILS, according
to claim 1, wherein said plasticizer presents oxirane index equal
to or less than 8.
5. PROCESS FOR OBTAINING PRIMARY PVC PLASTICIZERS DERIVED FROM
VEGETABLE OILS, as defined in claim 1, wherein comprising the steps
of: complete transesterification of at least one vegetable oil with
ethanol; subsequent epoxidation of the ester obtained at the step
of transesterification.
6. PROCESS, according to claim 5, wherein said vegetable oil is
selected from soybean oil, corn oil, linseed oil, sunflower oil, or
a mixture thereof.
7. PROCESS, according to claim 6, wherein said vegetable oil is
soybean oil.
8. PRIMARY PVC PLASTICIZERS DERIVED FROM VEGETABLE OILS, comprising
the general formula: ##STR00004## wherein R is randomly selected
from the group of epoxidized oleic, linoleic and linolenic
acids.
9. PRIMARY PVC PLASTICIZERS DERIVED FROM VEGETABLE OILS, according
to claim 8, wherein said plasticizer is epoxidized isoamylic
ester.
10. PRIMARY PVC PLASTICIZERS DERIVED FROM VEGETABLE OILS, according
to claim 8, wherein said plasticizer is epoxidized isoamyl
soyate.
11. PRIMARY PVC PLASTICIZERS DERIVED FROM VEGETABLE OILS, according
to claims 8 to 10, wherein said plasticizer presents oxirane index
equal to or less than 8.
12. PROCESS FOR OBTAINING PRIMARY PVC PLASTICIZERS DERIVED FROM
VEGETABLE OILS, as defined in claim 8, comprising the steps of:
complete transesterification of at least one vegetable oil with
isoamylic alcohol; subsequent epoxidation of the ester obtained at
the step of transesterification.
13. PROCESS, according to claim 12, wherein said vegetable oil is
selected from soybean oil, corn oil, linseed oil, sunflower oil, or
a mixture thereof.
14. PROCESS, according to claim 13, wherein said vegetable oil is
soybean oil.
15. PLASTICIZED PVC COMPOSITION, comprising: i) 100 parts
(weight/weight) of at least one PVC resin; ii) 1 to 200 parts
weight/weight) of at least one ester as defined in claim 1.
16. PLASTICIZED PVC COMPOSITION, comprising: i) 100 parts
(weight/weight) of at least one PVC resin; ii) 1 to 200 parts
weight/weight) of at least one ester as defined in claim 9.
Description
[0001] The present descriptive report refers to a patent of
invention of PVC plasticizers composed of ethyl and/or isoamyl
esters of vegetable oil fatty acids, obtained by
transesterification and epoxidation and PVC compounds plasticized
with bioesters, belonging to the technical field of polymer
additives that were developed to improve the properties of PVC
polymers, in addition to providing a lower cost for renewable
compounds, such as those obtained with the use of vegetable
oils.
[0002] Polyvinyl chloride (PVC) is a polymer well known for its
wide range of industrial applications. Its natural rigidity, due to
its molecular structure, requires the use of some additives to
increase the range of useful applications. These compositions are
commonly known as PVC compounds.
[0003] Among known compounds, plasticized PVC compounds present
high flexibility and are used in films, wire and cable insulation,
packaging, hoses, toys, etc. Plasticized PVC compounds are obtained
by the addition, in different levels, of additives known as
plasticizers, to provide the desired flexibility.
[0004] Plasticizers are, in general, high boiling point liquids
with average molecular weight (between 300 and 600), linear or
cyclic carbon chains (14 to 40 carbons) that, when added to the PVC
resin allow for movement between the PVC molecules promoting
flexibility to the final compound.
[0005] Currently, the major primary plasticizers used in the
industry are the phthalates, obtained from petroleum. In addition
to being dependent on the fluctuations of petroleum prices,
phthalates are suspect of having adverse effects on human
health.
[0006] As a result, a search was initiated to find alternatives
that are technically and economically viable to replace petroleum
based plasticizers. Epoxidized soybean oil was proposed as a
primary plasticizer. However, its low compatibility with PVC
limited its use to small quantities, keeping it from completely
replacing phthalates as a primary plasticizer.
[0007] Another proposition was the use of epoxidized linseed oil,
that in spite of having a similar molecular weight to soybean oil
presents a higher oxirane index (8 to 12) and thus greater
compatibility with PVC. However, its use is severely restricted due
to its higher price.
[0008] As such, several initiatives have proposed the use of
epoxidized bioesters, obtained from the transesterification or
interesterification of vegetable oils combined with epoxidation, as
primary plasticizers for PVC. Patent GB934689 describes the
preparation of esters with high oxirane index (8,5 to 12,33) from
vegetable oils with high linolenic acid contents (such as linseed
oil) and high iodine index (175 to 200), that are transesterified
with lower alcohols and subsequently epoxidized. Patents U.S. Pat.
No. 4,421,886 and U.S. Pat. No. 5,886,072 propose the use of esters
of soybean oil transesterified with pentaeritritol, whereas the
latter patent proposes the use of these esters in a mixture with
other plasticizers. Patent U.S. Pat. No. 4,605,694 describes the
use of trimelitic acid and pentaeritritol esters, while the patent
U.S. Pat. No. 5,430,108 proposes the use of esters of
pentaeritritol with alcanoic acid. Finally, the Brazilian patent
application BR 0111905-2 describes the use of soybean oil
transesterified with methanol, ethylene glycol, propylene glycol,
pentaeritritol, saccharose, and interesterified linseed oil.
[0009] Some of these esters (obtained from pentaeritritol,
trimelitic acid, ethylene glycol, propylene glycol and
interesterified linseed oil) as plasticizers present the drawback
of having larger molecular weight and much higher cost when
compared to phthalates. Others obtained from methanol, still have a
price dependency on petroleum. Additionally, the proposed esters
are composed by mixtures of esters with oxirane indexes greater
than 8. Finally, with exception of the methanol esters, the other
types of esters have been used as primary plasticizers for PVC only
in laboratory tests, indicating the difficulty in obtaining an
additive that is both technically and economically viable.
[0010] Therefore, the objective of the present invention is to
obtain technically and economically viable alternatives of primary
plasticizers for PVC compounds derived exclusively from renewable
sources (vegetable oils, sugar cane ethanol and sugar cane
isoamylic alcohol) that are completely compatible with the PVC
resin.
[0011] With the purpose of overcoming the aforementioned problems
and complying with the objectives previously described, the
invention developed compositions of plasticizers obtained from the
complete transesterification and epoxidation of vegetable oils,
henceforth called epoxidized bioesters. Complete
transesterification and epoxidation occur when the reactions
achieve a minimum of 99% conversion. This invention differs from
the state of the art by providing epoxidized bioester plasticizers,
presenting low linolenic acid content, and oxirane indexes below 8.
The epoxidized bioesters are obtained by the transesterification
reaction of vegetable oils with mono-alcohols derived from sugar
cane, such as ethanol and isoamylic alcohol, and subsequent
epoxidation.
[0012] Vegetable oils are composed by triglycerides that contain
glycerin molecules attached to three saturated, mono-unsaturated,
di-unsaturated and tri-unsaturated acids such as palmitic, oleic,
linoleic, and linolenic acids, among others. These fatty acids vary
also in regards to the size of the carbon chain, presenting 14 to
18 carbon atoms for the oils referred in this invention.
[0013] The transesterification reaction of vegetable oils is
employed to separate these fatty acids from the glycerin molecule
and bond them to other alcohol molecules, providing superior
properties when compared to those of the triglyceride. The
transesterification reaction results in the formation of different
esters (depending on the type of alcohol used), with a common
alcohol termination. This wide range of ester varieties increases
the possibilities of compatibility with PVC, in addition to
allowing different properties in the plasticized PVC.
[0014] The epoxidation process, of public domain, introduces an
atom of oxygen in the double bonds of the fatty acid carbon chain,
forming an oxirane ring that makes the ester more polar and thus
more compatible with the PVC resin. The greater the number of
double bonds in the original ester, the greater the number of
oxirane rings formed, and therefore increased compatibility with
PVC. In addition, the substitution of the double bonds by the
oxirane ring in the fatty acid chains increases the chemical and
thermal stability of the resulting molecule.
[0015] The compatibility of the epoxidized bioesters with the PVC
resin depends on the unsaturation of the original esters and the
level of epoxidation of the double bonds. The bioesters of this
invention present compatibility with PVC even when the resulting
oxirane index is below 8, which is not foreseen in the current
state of the art.
[0016] In a preferred embodiment the bioesters are obtained by the
transesterification of a mixture of vegetable oils or one vegetable
oil, such as soybean oil, with ethanol. After obtained, the
bioesters are epoxidized. The vegetable oils are chosen among the
oils with an iodine index between 120 and 170, such as soybean oil,
corn oil, linseed oil, sunflower oil, or a mixture thereof.
[0017] In the transesterification reaction, the refined soybean oil
reacts with anhydrous ethanol in the presence of sodium ethoxide
based catalysts, in the molar proportion oil:alcohol of 1:10 to
1:30 and temperatures between 80.degree. C. and 120.degree. C. The
glycerin formed in the reaction is separated and the soybean oil
ethyl ester is obtained (ethyl soyate) with a high degree of
purity. The new ester is then submitted to the epoxidation
reaction, where the double bonds of the esters are broken in the
presence of free oxygen under specific temperature and mixing
condition to form the oxirane rings.
[0018] Another embodiment is the production of bioesters from the
transesterification of a mixture of vegetable oils or one vegetable
oil, with iodine index between 120 and 170 such as soybean oil,
with isoamylic alcohol. The isoamylic alcohol is obtained from the
residue of sugar cane based ethanol production (also known as fusel
oil). After formed, the bioesters are epoxidized. The vegetable
oils are chosen among the oils with an iodine index between 120 and
170, such as soybean oil, corn oil, linseed oil, sunflower oil, or
a mixture thereof.
[0019] The transesterification process is similar to that used in
the production of ethyl soyate, replacing the catalyst system by
alkyl sodium oxides, and molar proportions oil:alcohol of 1:15 to
1:50 and temperatures in the range between 80.degree. C. and
130.degree. C. The resulting ester is submitted to the same
epoxidation process used in the production of the epoxidized ethyl
soyate.
[0020] The processes of preparation of the epoxidized ethyl and
isoamyl bioesters are detailed below.
[0021] 1--EPOXIDIZED ETHYL SOYATE
[0022] TRANSESTERIFICATION REACTION: First, 35 g of sodium
hydroxide 99% (NaOH) are added to 200 ml of anhydrous ethanol,
forming sodium ethoxide in a stoichiometric quantity considering
the sodium hydroxide amount, with excess ethanol. In a reactor with
mechanical stirring, 1 liter of soybean oil is pre-heated to
60.degree. C. The 200 ml of sodium/ethanol mixture plus an
additional 300 ml of ethanol are added to the reactor. The stirring
and temperature are maintained constant for 90 minutes. The
reaction forms glycerin, soybean oil acids ethyl ester and excess
ethanol and sodium ethoxide. After the reaction, the stirring and
heating are turned off and the whole mixture is transferred to a
separation funnel. After 10 hours decanting, the glycerin
accumulated in the bottom is removed, leaving only the ester in the
funnel. The ester is washed with water, adding 1 liter of water to
the mixture, intense agitation without heating and subsequent
decanting for 3 to 6 hours (depending on the speed of separation)
until the two phases present a clear interface. The washing
procedure is repeated with until the bottom phase is clear after
decanting. The ester is then dried at 40.degree. C. for 2 to 4
hours until the material is clear and presents no cloudiness.
[0023] EPOXIDATION REACTION: In a reactor with mechanical stirring,
temperature control and reflux condenser, 500 g of the ethyl ester
is added and the temperature is elevated to 80.degree. C. Formic
acid is added and the mixture is kept at constant agitation. Slowly
(for 45 minutes or more) 184 g of hydrogen peroxide 50% is added,
controlling the temperature at 90.degree. C. After the addition of
the hydrogen peroxide, the system is maintained at 80.degree. for 4
hours. At the end of the reaction, the water phase is separated
from the oil phase in a separation funnel. The oil phase contains
the epoxidized ester and the formic acid. The wash of the oil phase
is processed according to the procedure described for the wash of
the ethyl ester after the transesterification; although the water
needs to be preheated to 50.degree. C. and the wash procedure shall
be repeated until all the formic acid has been eliminated. The
finished product present an oxirane index above 4.5, acidity below
5 mg KOH/g, characteristic odor and slight yellow color.
[0024] The final product obtained is the epoxidized ethyl ester of
a mixture of soybean oil acids (epoxidized ethyl soyate), which is
a viscous transparent liquid slightly yellow and with a faint odor
similar in characteristic to the original soybean oil used. The
epoxidized ethyl ester presents an oxirane index between 4 and 8,
linear molecular chain with an average (20 carbon atoms) and lower
average molecular weight (about 340) when compared to the
epoxidized soybean oil (900).
[0025] The composition of the epoxidized ethyl soyate presents the
following formula:
##STR00001##
[0026] With R preferably selected randomly from the epoxidized
oleic, linoleic and linolenic acids.
[0027] 2--EPOXIDIZED ISOAMYL SOYATE
[0028] TRANSESTERIFICATION REACTION: Initially, 35 g of sodium
hydroxide 99% are added to 200 ml of isoamylic alcohol, forming
sodium isoamyloxide in a stoichiometric quantity related to the
sodium hydroxide, with excess isoamylic alcohol. In a reactor with
mechanical agitation, 1 liter of soybean oil is preheated to
80.degree. C. and the previously prepared alcohol and sodium
hydroxide are added to the reactor, with an additional 1600 ml of
isoamylic alcohol. The stirring and temperature are maintained
constant for 120 minutes. The reaction produces glycerin, isoamyl
ester of soybean oil fatty acids, excess of non-reacted isoamylic
alcohol, and sodium isoamyloxide. After the reaction, the stirring
and heating are turned off and the entire mixture is transferred to
separation funnel. After 10 hours decanting the glycerin is removed
from the funnel, leaving only the ester. The isoamyl ester is then
washed with water, adding 1 liter of water at 70.degree. C. to the
mixture, intense stirring and subsequent decanting for 3 to 6 hours
(depending on the speed of separation) until a clear interface
appears. The aqueous phase is removed from the funnel and the wash
is repeated until the material in the aqueous phase is clear. The
ester is dried by heating at 70.degree. C., for 2 to 4 hours until
the material becomes totally clear, without cloudiness.
[0029] EPOXIDATION REACTION: In a reactor with mechanical stirring,
temperature control and reflux condenser, 500 g of the isoamyl
ester is added and the temperature is elevated to 80.degree. C. 60
g of formic acid (91%) is added and the mixture is kept at a
constant agitation. Slowly (along 45 minutes or more) 178 g of
hydrogen peroxide (50%) is added, controlling the temperature at
90.degree. C. After the addition of the hydrogen peroxide, the
system is maintained at 80.degree. for 4 hours. At the end of the
reaction, the water phase is separated from the oil phase in a
separation funnel. The oil phase contains the epoxidized ester and
the formic acid. The wash of the oil phase is processed according
to the procedure described for the wash of the ethyl ester after
the transesterification, although the water needs to be preheated
to 50.degree. C. and the wash procedure shall be repeated until all
the formic acid has been eliminated. The finished product presents
an oxirane index above 4.5, acidity below 5 mg KOH/g,
characteristic odor, and slight yellow color.
[0030] The final product obtained is the epoxidized isoamyl ester
(epoxidized isoamyl soyate) of a mixture of soybean oil acids,
which is a viscous transparent liquid slightly yellow and with a
faint odor similar in characteristic to the original soybean oil
used. The epoxidized isoamyl soyate presents an oxirane index
between 4 and 8, linear molecular chain with average (23 carbon
atoms) and lower average molecular weight (380) when compared to
the epoxidized soybean oil.
[0031] The plasticizers of epoxidized isoamyl soyate present the
followinq formula:
##STR00002##
[0032] R is preferably selected randomly from the epoxidized oleic,
linoleic, and linolenic acid groups.
[0033] In another embodiment, plasticized PVC is obtained by mixing
i) 100 parts (weight/weight) of at least one type of PVC resin; ii)
1 to 200 parts (weight/weight) of plasticizer, which consists of
epoxidized bioesters with an oxirane index below 8; the mixture is
then homogenized and later extruded.
[0034] In a preferred embodiment the plasticizer is made from
vegetable oils completely transesterified with ethanol and later
epoxidized, such as the esters of the type epoxidized ethyl soyate.
In another preferred embodiment the plasticizer is made from
vegetable oils completely transesterified with isoamylic alcohol
and later epoxidized, such as the esters of the type epoxidized
isoamyl soyate. In another preferred embodiment the plasticizer is
made from a mixture of epoxidized ethanol and isoamylic alcohol
bioesters, such as epoxidized ethyl soyate and epoxidized isoamyl
soyate.
[0035] The plasticized PVC is therefore free of phthalate
plasticizers. It is important to point out that the plasticizers
composed of epoxidized bioesters of ethanol and/or isoamylic
alcohol provide some property improvements to the plasticized PVC,
improvements not foreseen in the state of the art, such as greater
flexibility, greater resistance to UV light degradation, better
physical properties at low temperatures, better mixture efficiency
(salvation) of the PVC resin and better resistance to aliphatic
solvents extraction.
[0036] PVC compounds plasticized with the objects of this invention
present superiority in all these properties when compared to
plasticized PVC prepared with plasticizers revealed by the state of
the art while keeping the same proportion of plasticizer/PVC
resin.
[0037] When compared to the epoxidized ethyl soyate, the epoxidized
isoamyl soyate has a heavier and longer carbon chain, allowing for
its use in applications requiring greater permanence over time.
[0038] Therefore, the plasticizers of this invention work out the
inconveniencies described in the state of the art, presenting the
following additional advantages:
[0039] 1. Can be produced from natural, renewable and economically
viable sources (sugar cane and soybean oil), in addition to being
adequate to human contact;
[0040] 2. Are totally compatible with the PVC resin, when compared
to the epoxidized soybean oil;
[0041] 3. Present less odor and coloration when compared to the
epoxidized soybean oil;
[0042] 4. Present competitive costs when compared to all primary
plasticizers and significantly lower costs when compared to the
current alternatives to replace phthalates (trimelitates, citrates,
polimerics);
[0043] 5. Provide better plasticization efficiency in the PVC
compound when compared to the current primary plasticizers
alternatives or the majority of the developments of the state of
the art, producing lighter and more flexible compounds with less
plasticizers;
[0044] 6. Offer better mixture efficiency (salvation) with the PVC
resin, when compared to the current alternatives or plasticizers
revealed by the state of the art, allowing more efficient
production processes for the PVC industry;
[0045] 7. Aid in the thermal stabilization of PVC, allowing more
processing tolerance or cost reduction of the stabilizers package,
when compared to the current alternatives of primary
plasticizers;
[0046] 8. Offer better UV resistance to the PVC compound allowing
the use of PVC compounds for longer periods or cost reduction of
the UV protection additive packages, when compared to the current
primary plasticizers alternatives;
[0047] 9. Provide better physical properties at low temperatures,
when compared to the current primary plasticizers alternatives
based on phthalates;
[0048] 10. Provide better resistance to aliphatic solvent
extraction, when compared to current alternatives of primary
plasticizers, mainly phthalates;
[0049] In summary, the objects of this invention present
complementary benefits and additional advantages that are not
foreseen by the state of the art.
[0050] The scope of this patent of invention shall not be limited
to the described applications, but to the terms defined in the
claims and its equivalents.
* * * * *