U.S. patent application number 09/754966 was filed with the patent office on 2002-01-24 for process for producing vinyl polymers.
Invention is credited to Asada, Takesi, Nakai, Toru.
Application Number | 20020010294 09/754966 |
Document ID | / |
Family ID | 13041331 |
Filed Date | 2002-01-24 |
United States Patent
Application |
20020010294 |
Kind Code |
A1 |
Nakai, Toru ; et
al. |
January 24, 2002 |
Process for producing vinyl polymers
Abstract
The present invention provides a process for producing a vinyl
polymer characterized in that, in a radical polymerization of a
vinyl monomer, a substituted hydroxylamine represented by a general
formula: 1 (in which R.sub.1 and R.sub.2 represent hydrogen, a
(substituted) aliphatic hydrocarbon group having one or more carbon
atom(s) or an aromatic hydrocarbon group) and/or a general formula:
2 (in which; and R.sub.3 and R.sub.4 represented a (substituted)
aliphatic hydrocarbon group having one or more carbon atom(s)) is
added. A radically polymerized vinyl polymer having a high
molecular weight and a restrained molecular weight distribution can
be obtained by the process of the present invention, even under a
polymerization condition at a high temperature. The present
invention provides, therefore, a process enabling to produce vinyl
polymers which promise to have practical properties such as
appearance, mechanical properties and heat resistance useful as
materials for various moldings and coatings. Thus, the industrial
and practical value of the present invention is extremely high.
Inventors: |
Nakai, Toru; (Hyogo, JP)
; Asada, Takesi; (Hyogo, JP) |
Correspondence
Address: |
TOWNSEND AND TOWNSEND AND CREW
TWO EMBARCADERO CENTER
EIGHTH FLOOR
SAN FRANCISCO
CA
94111-3834
US
|
Family ID: |
13041331 |
Appl. No.: |
09/754966 |
Filed: |
January 4, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09754966 |
Jan 4, 2001 |
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09026745 |
Feb 20, 1998 |
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6242546 |
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Current U.S.
Class: |
526/204 ;
526/211 |
Current CPC
Class: |
C08F 4/32 20130101; C08F
2/38 20130101 |
Class at
Publication: |
526/204 ;
526/211 |
International
Class: |
C08F 004/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 24, 1997 |
JP |
9-56933 |
Claims
1. A process for producing a vinyl polymer characterized in that,
in a radical polymerization of a vinyl monomer, a substituted
hydroxylamine represented by a general formula: 5(in which R.sub.1
and R.sub.2 represent hydrogen, a (substituted) aliphatic
hydrocarbon group having one or more carbon atom(s) or an aromatic
hydrocarbon group) and/or a general formula: 6(in which R.sub.3 and
R.sub.4 represent a (substituted) aliphatic hydrocarbon group
having one or more carbon atom(s)) is added.
2. A process for producing a vinyl polymer set forth in claim 1
characterized in that the radical polymerization is carried out a
radical polymerization initiator.
3. A process for producing a vinyl polymer set forth in claim 2
characterized in that the radical polymer initiator is used at a
mole ratio between said radical polymerization initiator and the
vinyl monomer of 0.001/100-101100 (radical polymerization
initiator/vinyl monomer).
4. A process for producing a vinyl polymer set forth in claim 2 or
3 characterized in that the substituted hydroxylamine set forth in
claim 1 and the radical polymerization initiator are used at a mole
ratio between said substituted hydroxylamine and said radical
polymerization initiator of 0.01/1-100/1 (substituted
hydroxylamine/radical polymerization initiator).
5. A process for producing a vinyl polymer set forth in any one of
claims 1-4 characterized that the vinyl monomer is an aromatic
compound.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method of radical
polymerization of a vinyl monomer in the presence of a specific
substance, and particularly, to a process for efficiently producing
a vinyl polymer which has a high molecular weight desirable for
practical properties such as mechanical properties, heat resistance
and the like, and which has controlled molecular weight
distribution.
[0003] 2. Description of the Prior Art
[0004] In conventional radical polymerization, the molecular weight
of the produced polymer strongly depends on the polymerization
temperature, that is, the molecular weight of the polymer obtained
is restricted by the polymerization temperature. Although the
polymerization temperature is typically lowered in order to achieve
a high molecular weight, decrease in polymerization temperature
will elongate the polymerization time and increase the amount of
remaining monomer. It becomes, therefore, difficult to effect an
efficient production. Similarly, although the polymerization
temperature is typically elevated in order to achieve a low
molecular weight, increase in polymerization temperature so
accelerate the polymerization rate that it becomes difficult to
control the reaction. For these reasons, there is a wide need for a
polymerization method of freely onto the molecular weight in a
radical polymerization.
[0005] As an attempt to control the molecular weight in a radical
polymerization, Tatemoto et al. have reported that radical
polymerization of a fluorine-containing monomer such as
tetrafluoroethylene proceeds in a manner like living polymerization
in the presence of an iodine compound such as (CF.sub.3).sub.2CF-I
(Sozo Tatemoto, Koubunshi-Ronbun-Shu 49, 765 (1992)). Likewise,
Otsu et al. have found that, when certain sulfur compounds were
used, radical polymerization of styrene or the like occurred under
light irradiation and that the extent of conversion and the
molecular weight of the produced polymer with the time (J. Polym
sci; part A; polym. chem., 32, 2911 (1994)). According to these
methods, it is possible to control the molecular weight in a
considerably wide range. However, these methods lack universality
because they require a special polymerization initiator or a use of
limited kinds of monomer.
[0006] In anionic polymerization, a precise control of the
molecular weight is possible by a polymerization on method called
living polymerization. Recently, it has also become popular to
research a polymerization system which enables living
polymerization in radical polymerization For example, it has been
shown in Japanese Patent Publication No. 94-199916 A that, by using
a radical polymerization initiator such as benzoyl peroxide
together wait a stable free radical agent such as
2,2,6,6-tetramethyl-piperidinyloxy (TEMPO), a living-like
polymerization of styrene can be achieved. According to this
method, by selecting a polymerization condition, the molecular
weight of the polymer obtained will depend not only on the
polymerization temperature but also on the amounts of the initiator
and the stable free radical agent used, so that one can control the
molecular weight by those amounts to a certain extent.
[0007] Thus, when the above method is used, one can obtain a resin
having a controlled molecular weight. However, this method has a
drawback that the reaction rate in this method is so slow that it
takes considerably more time compared with the usual radical
polymerization to reach a high extent of conversion. In addition,
coloration of the obtained polymer may sometimes occur depending on
few reaction condition. Furthermore, TEMPO requires special
attention in its handling and storage because it exists in radical
state, and it is also very expensive. This method has thus some
shortcomings that for example, it requires more production costs
compared with conventional methods.
[0008] In view of such a situation, the present inventors have
concentrated their efforts on controlling the radical reaction of
vinyl monomer with the aim of increasing productivity and improving
practical physical properties of radically polymerized vinyl
polymers. In result, we have found by chance a method for obtaining
a vinyl polymer having a high molecular weight and a restrained
molecular weight distribution while retaining a high polymerization
rate by including a specific substituted alkylhydroxylamine in the
polymerization system, and thus completed the present
invention.
SUMMARY OF THE INVENTION
[0009] The present invention provides a process for producing a
vinyl polymer characterized in that, in a radical polymerization of
a vinyl monomer, a substituted hydroxylamine represented by a
general formula: 3(in which R.sub.1 and R.sub.2 represent hydrogen,
a (substituted) aliphatic hydrocarbon group having one or more
carbon atom(s) or an aromatic hydrocarbon group) and/or a general
formula. 4
[0010] (in which and R.sub.3 and R.sub.4 represent a (substituted)
aliphatic hydrocarbon group having one or more carbon atom(s)) is
added.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] The present invention is described below in more detail
[0012] In each of R.sub.1 and R.sub.2 of the general formula (I) of
the present invention, the aliphatic hydrocarbon group may include,
for example, methyl, ethyl, isopropyl, t-butyl, butyl and the like
group, and the aromatic hydrocarbon group may include, for example,
phenyl, bensyl and the like group.
[0013] Similarly, --R.sub.3--R.sub.4 in the general formula (2) may
include a divalent (substituted) aliphatic hydrocarbon group
corresponding to those groups in the general formula (1) such as
--CH.sub.3CH.sub.2--, --CH.sub.2CH.sub.2CH.sub.2CH.sub.2--,
--CH(CH.sub.2)CH.sub.2--CH(CH.sub.2)CH.sub.2----C(CH.sub.2).sub.2CH.sub.2-
--C(CH.sub.2).sub.3CH.sub.2--,
--CH.sub.2CH.sub.2CH.sub.2CH.sub.2--CH.sub.-
2CH.sub.2CH.sub.2CH.sub.2--, or the like.
[0014] Furthermore, the hydrocarbon groups i the above general
formulas (1) and (2) may optionally be substituted, and the
substitutent may include, for example, an aliphatic hydrocarbon
such as a methyl or ethyl group, an aromatic hydrocarbon such as a
phenyl group, halogen a halogenated hydrocarbon, a carbonyl group,
a hydroxy group, an amino group, and the like.
[0015] In the present invention, the substance presented by the
general formula (1) (substituted hydroxylamine) may include
dimethylhydroxylamine, dimethylhydroxylamine,
isopropylhydroxylamine, dimethylhydroxylamine, and the like.
[0016] In the present invention, the substance represented by the
general formula (2) may include N-hydroxylamine
N-hydroxylsuccinimide, N-hydroxylphthalimide and the like.
[0017] In the present invention, although the radical
polymerization may be initiated by any of the known methods, for
example, using an initiator, heat, light or radioactive rays, it is
preferable to use an initiator. Although there is no special
restriction on the ratio of the substance represented by the above
general formulas(1) and (2) (substituted hydroxylamine) used to the
radical polymerization initiator, it is preferable to use a mole
ratio between the substance represented by the above general
formulas(1) and (2) and the radical polymerization initiator at
0.01/1-100/1 (substance represented by the above general
formulas(l) and (2)[substituted hydroxylamine]/radical
polymerization initiator), more preferably at 0.1/1-10/1, and
particularly preferably at 0.1/1-1.0/1. At a mole ratio of the
substance represented by the above general formula (1) and (2) to
the radical polymerization initiator below 0.01/1, it will be
difficult to control the molecular weight and molecular weight
distribution, while at a mole ratio above 100/1, he polymerization
rate will decrease.
[0018] There is no special restriction on the vinyl monomer used in
the present invention, and it may be exemplified by aromatic vinyl
compounds, .alpha., .beta.-unsaturated carboxylic acids, .alpha.,
.beta.-unsaturated carboxylic acid esters, .alpha.,
.beta.-unsaturated carboxylic amides, .alpha., .beta.-unsaturated
nitrites, vinyl carboxylates, vinyl halides, vinylidene halides,
conjugated dienes and the like compounds capable of radically
polymer.
[0019] As an aromatic vinyl compound, although styrene is typically
used, other aromatic vinyl compounds, for example, an
alkyl-substituted styrene such as o-methylstyrene, p-methylstyrene,
m-methylstyrene, 2,4-dimethylstyrene, p-ethylstyrene,
p-t-butylstyrene, .alpha.-methylstyrene or
.alpha.-methyl-methylstyrene, and an halogenated styrene such as
o-chlorostyrene or p-chlorostyrene may also be used. A preferable
aromatic vinyl compound includes, for example, styrene,
.alpha.-methylstyrene and p-methylstyrene; and styrene is
especially preferable.
[0020] The .alpha.-unsaturated carboxylic acid may include acrylic
acid, methacrylic acid and the like. The .alpha.,
.beta.-unsaturated carboxylic acid ester may include, for example,
alkyl acrylates such as methyl acrylate, ethyl acrylate and n-butyl
acrylate, alkyl methacrylates such as methyl methecrylate, ethyl
methacrylate and butyl methacrylate, and derivatives thereof. The
.alpha.,.beta.-unsaturated carboxylic amide may include, for
example, acrylamide, methacrylamide, and derivatives thereof. The
.alpha., .beta.-unsaturated nitrile may include acrylonitrile,
methacrylonitrile, .alpha.-chloroacrylonitrile and the like. The
vinyl carboxylates may include vinyl acetate, vinyl propionate and
the like. The vinyl halide may include vinyl fluoride, vinyl
chloride, vinyl bromide, vinyl iodide and the like. The vinylidene
halide may include vinylidene fluoride, vinylidene chloride,
vinylidene bromide, vinylidene iodide and the like. The conjugated
diene compound may include butadiene, isoprene, chloroprene,
piperidene, chlorobutadiene and the like.
[0021] There is no special restriction on the radical
polymerization initiator used in the present invention so far as it
is capable of initiating radical polymerization, and the following
compounds may be used, for example: organic peroxides, for example,
peroxyketals such as
2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane,
1,1-bis(t-butylperoxy)-3,- 3,5-trimethylcyclohexane,
1,1-bis(t-butylperoxy)cyclohexane and
n-butyl-4,4bis(t-butylperoxy)valerate, hydroperoxides such as
cumene hydroperoxide and diisopropylbenzene peroxide peroxide,
dialkyl hydroperoxides such as t-butylcumyl peroxide and di-t-butyl
peroxide, diacyl peroxides such as lauroyl peroxide and benzoyl
peroxide, peroxydicarbonates such as bis(t-butylcyclohexyl)
peroxydicarbonate, and peroxyesters such as t-butyl peroxybenzoate,
t-butyl peroxyacetate and 2,5-dimethyl-2,5-dibenzoylperoxy)hexane;
azo compounds such as azoisobutyronitrile,
2,2-iazobis(2methylbutyronitrile), and
1,1-azobis(cyclohexaril-carbonitrile); and peroxide such as benzoyl
peroxide.
[0022] The radical polymerization initiator is preferably used at a
mole ratio to vinyl monomer of 0.001/100-10/100 (radical
polymerization initiator/vinyl monomer), and more preferably at a
mole ratio of 0.01/100-1/100. This is because, at a ratio of
radical imitator to vinyl monomer below 0.001/100, it will be
difficult to control the molecular weight, and at a mole ratio
above 10/100, the polymerization will proceed so quickly that it
becomes difficult to control the reaction.
[0023] There is no special restriction on the process of carrying
out the polymerization of the present invention, and any of the
usual polymerization modes such as bulk polymerization, suspension
polymerization, bulk-suspension polymerization and solution
polymerization may be used In the case of solution polymerization,
no more than 20 parts by weight of solvent may be included in the
process with 100 parts by weight of vinyl monomer, if necessary.
Solvent more than 20 parts by weight is disadvantageous because it
will decrease the polymerization rate and productivity.
[0024] There is no special restriction on the solvent included in
tee process so far as the monomer and the produced polymer as
soluble in the solvent. An example of solvent may be toluene,
ethylbenzene, methyl ethyl ketone, benzene or the like, and toluene
or ethylbenzene is especially preferred because the boiling points
are close to the polymerization temperature. The above solvents may
be used alone or in combination.
[0025] Furthermore, according to the process of the present
invention, the molecular weight can be controlled by the amounts of
the initiator and the monomer as well as the extent of conversion,
so that the polymerization can be conducted in a very simple mode.
Furthermore, according to the process of the present invention the
molecular weight can be controlled by the amounts of the initiator
and substance represented by the above general form (1) or (2). It
is, therefore, very easy to industrialize the present invention.
The process according to the present invention may be carried out
in a continuous mode or in batch.
[0026] The polymerization temperature at which the present
invention operates is typically 60.degree. C.-160.degree. C., and
preferably 90.degree. C.-150.degree. C. At a temperature below
60.degree. C., the reaction rate will be too low for an industrial
production process, while at a temperature above 160.degree. C.
side reactions during the polymerization will occur to a extent not
negligible, rendering the reaction control difficult.
[0027] When a stricter control is required in carrying out the
present invention, a compound which has a function controlling heat
polymerization may be used, if necessary. Among the compounds
having such a function are, for example, phenylphosphonic acid, D,
L-camphor-10-sulfonic acid, p-toluenesulfonic acid,
2-fluoro-1-methylpyridininium and the like.
[0028] When a thermoplastic resin is produced by the process of the
present invention, admixes, stabilizers or the like agents usually
used may be added. For example, in the case of styrene-based
thermoplastic resins, a lubricant such as mineral oil, silicone
oil, zinc stearate, calcium stearate, or ethylenebisstearylamide,
an oxidation inhibitor such as a phenolic or phosphorus
antioxidant, a UV absorbent, and a colorant may be added during or
after the polymerization.
[0029] The present invention will be further illustrated by the
following Examples to which the present invention is not
restricted.
EXAMPLES
[0030] As described below, the polymers of Examples 1-7 and
References 1-2 were subjected to the follow measurements (1) and
(2), and the results are summarized in Table 1.
[0031] (1) Measurement of conversion
[0032] The extent of conversion was calculated by
gas-chromatographically quantifying the amount of remaining monomer
in the reaction solution sampled at a given interval during the
reaction.
[0033] (2) Measurement of the molecular weight
[0034] For the polymer in the reaction solution sampled at a given
interval during the reaction, the molecular weight was measured
according to a GPC method using a GPC (LC-10A) manufactured by
SHIMADZU CORPORATION and GPC columns (three KF-806L columns in
tandem) manufactured by Showa Denko K.K.
[0035] Unless otherwise indicated, the polymerization reaction was
earned out under nitrogen stern in a polymerization apparatus in
which a reactor having 20 L inner volume equipped with an agitator
was connected to a biaxial extender equipped with a vent line. The
stat time of the reaction was defined as the point when the
temperature reached 95.degree. C.
EXAMPLE 1
[0036] A stock solution consisting of 150 mol of styrene, 0.3 mol
of benzoyl peroxide and 0.15 mol of dimethylhydroxylamine was
introduced into the reaction, and heated with stirring at
95.degree. C. for 3.5 hours. After raising the temperature to
130.degree. C., stirring was continued for additional 4.5 hours to
synthesize the polymer. After removing remaining monomer
polystyrene was recovered from the biaxial eider to obtain the
polymer of Example 1.
EXAMPLE 2
[0037] A stock solution consisting of 150 mol of styrene, 0.3 mol
of benzyl peroxide and 0.09 mol of diethylhydroxylamine was
introduced into the reactor, and polymerized at 95.degree. C. for 3
hours. Then, the polymer of Example 2 was obtained by following the
same procedures as those in Example 1.
EXAMPLE 3
[0038] A stock solution consisting of 150 mol of styrene, 0.3 mol
of benzoyl peroxide and 0.21 mol of diethylhydroxylamine was
introduced into the reactor, and the polymer of Example 3 was then
obtained by following the same procedures as those in Example
1.
EXAMPLE 4
[0039] A stock solution consisting of 150 mol of styrene, 0.3 mol
of benzoyl peroxide, 0.15 mol of diethylhydroxylamine and 0.3 mol
of camphorsulfonic acid was introduced into the reactor, and the
polymer of Example 4. Was obtained by following the same procedures
as those in Example 1.
EXAMPLE 5
[0040] A stock solution consisting of 150 mol of styrene, 0.3 mol
of benzoyl peroxide and 0.15 mol of diethylhydroxylamine was
introduced into the rector, and polymerized at 130.degree. C. for 6
hours. Then, the polymer of Example 5 was obtained by following the
same procedures as those in Example 1.
EXAMPLE 6
[0041] A stock solution consisting of 150 mol of styrene, 0.15 mol
of benzoyl peroxide and 0.075 mol of diethylhydroxylamine was
introduced into the reactor, and the polymer of Example 6 was the
obtained by following the same procedures as those in Example
1.
EXAMPLE 7
[0042] A stock solution consisting of 150 mol of styrene, 0.15 mol
of benzoyl peroxide and 0.075 mol of diethylhydroxylamine was
introduced into the reactor, and the polymer of Example 6 was then
obtained by following the same procedures as those in Example
1.
Reference 1
[0043] The polymer of Reference 1 was obtained by following the
same procedures as those in Example 1 with the exceptions that a
stock solution consisting of 150 mol of styrene and 0.3 mol of
benzoyl peroxide was introduced into the reactor and that the
reaction was stopped a 2 hours at 130.degree. C.
Reference 2
[0044] The polymer of Reference 2 was obtained by following same
procedures as those in Example 1 with the exceptions that a stock
solution consisting of 150 mol of styrene, 0.3 mol of benzoyl
peroxide and 0.36 mol of 2,2,6,6tetraethyl-1-piperidinyloxy was
introduced into the reactor and that the polymerization time was 80
hours.
EFFECTS OF THE INVENTION
[0045] As described above, a radically polymerized vinyl polymer
having a high molecular weight and a controlled molecular weight
distribution can be obtained by the process of the present
invention, even under a polymerization condition at a high
temperature. The present invention provides, therefore, a process
enabling to produce vinyl polymers which promise to have practical
properties such as appearance, mechanical properties and heat
resistance useful as materials for various moldings and coatings.
Thus, the industrial and technical value of the present invention
is extremely high.
1TABLE 1 Reaction Con- Time version Example (h) (%) Mn .times.
10.sup.-4 Mw .times. 10.sup.-4 Mw/Mn Example 1 2 21.0 4.06 6.62
1.53 4 40.4 5.34 7.58 1.36 8 74.6 7.80 10.45 1.30 Example 2 1 31.2
3.36 5.21 1.52 2 54.6 4.23 6.55 1.55 3 70.2 5.33 8.04 1.51 Example
3 2 11.7 4.87 7.89 1.62 4 18.2 5.86 9.02 1.54 6 42.5 7.08 10.55
1.49 8 80.3 8.81 12.51 1.42 Example 4 2 31.6 4.13 7.31 1.77 4 68.1
5.69 9.39 1.65 8 87.9 6.74 9.77 1.45 Example 5 1 12.4 2.40 4.82
2.01 3 45.3 5.22 8.87 1.70 6 88.6 7.68 12.60 1.64 Example 6 2 18.5
6.21 10.43 1.68 4 42.7 12.77 19.66 1.54 8 79.9 17.20 29.58 1.42
Example 7 2 10.1 5.61 10.22 1.82 4 20.4 8.94 15.65 1.75 8 55.7
15.26 26.09 1.71 Reference 1 0.5 54.3 4.75 15.44 3.25 1 70.2 4.44
13.01 2.93 2 89.4 5.26 13.26 2.52 Reference 2 20 22.1 0.22 10.50
1.33 40 43.6 0.51 9.77 1.28 80 70.5 0.80 11.30 1.27
* * * * *