JP3408279B2 - Method for producing high nitrile copolymer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a high nitrile copolymer.
It relates to a manufacturing method. More specifically, water
Use a specific azo-based polymerization initiator
Of unsaturated dicarboxylic acid remaining in the resulting copolymer
Very few tolyl monomers, transparency, gas barrier properties and
Of high nitrile copolymers with excellent chemical and chemical resistance
It is about. [0002] High nitrile copolymers have high transparency and chemical resistance.
Excellent in mechanical properties and mechanical properties.
When a high proportion of lyl monomer is contained,
Extremely excellent in gas barrier properties and chemical resistance
Food containers, spray containers, etc.
Is expanding to the application field of
Various studies on industrially advantageous production methods with uniform composition
It has been. For example, in Japanese Patent Publication No. 51-36315
Supplies aromatic vinyl monomer according to the heat of reaction
The method is described in U.S. Pat. No. 4,088,811.
Polymerization initiators such as zobisisobutyronitrile (AIBN)
While continuously supplying additional aromatic vinyl monomer using
For conducting a copolymerization reaction, Japanese Patent Publication No. 46-27808
According to the report, a method of setting the polymerization temperature stepwise,
No. 33917 discloses a combination of a plurality of polymerization initiators.
A method of increasing the temperature stepwise, as disclosed in JP-A-62-1710
Means continuous supply of aromatic vinyl monomer compound and control of polymerization temperature
Control of the amount of initiator decomposition by
I can do it. [0003] However, the characteristics of high nitrile copolymers
In the application field, especially in the food field,
The toxicity of unsaturated nitrile monomers is a major problem,
To reduce the amount of unsaturated nitrile monomer
A polymer was needed. Conventionally, high nitrile co-weight
Method for removing unsaturated nitrile monomer remaining in coalescence
Is removed by steam distillation after polymerization
Methods are generally known, but for example, residual unsaturated
In order to reduce the tolyl monomer to 10 ppm or less, 100
Steam for 7 to 10 hours at a temperature of
Operation, such as anchoring, is extremely inferior in productivity
Rika consumed a lot of energy. Also,
Due to prolonged exposure to high temperatures, the resulting copolymer
There were also problems such as poor coloring. [0004] The present invention is based on the above situation.
In view of the above, the residual unsaturated nitrile monomer is extremely small,
High nitrite with excellent transparency, gas barrier properties, and chemical resistance
Investigating methods for industrially advantageous production of ril copolymers
As a result of repeated studies, the present invention was completed.
is there. [0005] The present invention provides an unsaturated nitrile compound.
40 to 90% by weight of an aromatic vinyl monomer
60% by weight and a vinyl monomer copolymerizable therewith
0 to 20% by weight is represented by the following formula 1, and
Azo-based polymerization with 0 hour half-life temperature of 100 ° C or less
The first step of polymerization by an aqueous suspension method using
The monomer is removed by steam distillation at a temperature of 100 ° C or higher.
High nitrile
A method for producing a polymer. [0006] (X in Chemical Formula 2) ₁ , X _Two Is the --CN group or one
Is an alkyl group, R ₁ , R _Two , R _Three , R _Four Are those with 1 or more carbon atoms
R ₁ , R _Two , R _Three And R _Four Has a total carbon number of 6 or more
(R ₁ And R _Two , R _Three And R _Four Are linked by a covalent bond.
Azonitrile compound of the formula ₁ , X _Two But
-COOR (R is a methyl group), R ₁ , R _Two , R _Three , R _Four But charcoal
Azocarboester compounds which are alkyl groups having a prime number of 1 or more
Things. ). DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the present invention will be described in detail.
Will be described. (Copolymer component) High nitrile copolymer in the method of the present invention
Represents 40 to 90% by weight of an unsaturated nitrile monomer,
10 to 60% by weight of phenyl monomer and copolymerizable with them
From 0 to 20% by weight of a vinyl monomer
You. Preferably, the content of unsaturated nitrile monomer is 50
~ 80% by weight is preferred. 4 unsaturated nitrile monomers
If it is less than 0% by weight, gas blocking of high nitrile copolymer
Resistance, chemical resistance, etc.
If the monomer component exceeds 90% by weight, the high nitrile copolymer
Moldability and thermal stability during molding
It is not practical. In the present invention, the unsaturated nitrile monomer is
Acrylonitrile, methacrylonitrile, α-
Loloacrylonitrile and the like. These are kind
Alternatively, a mixture of two or more kinds may be used. Aromatic vinyl simple
Styrene, and the side chain or (and)
Substituted styrene (substituent is lower alkyl group, lower alkoxy
Group, trifluoromethyl group, halogen atom,
Other), for example, α-methylstyrene, p-methylstyrene
, O-methylstyrene, m-methylstyrene, nuclear halo
Genated styrene, α- or β-vinylnaphthalene,
There are others. These may be used alone or in combination of two or more.
Is also good. Other vinyl monomers copolymerizable therewith
Acrylates and methacrylate esters
And maleimides. High Nito of the present invention
When producing a ril resin, if necessary, an antioxidant,
UV absorbers, colorants, pigments or calcium carbonate,
Inorganic fillers such as talc, and magnesium stearate
A lubricant such as a rubber can be added. (Polymerization initiator) Used in the method of the present invention
As the polymerization initiator to be used, azo as shown in Chemical formula 1 is used.
-Based compounds are effective, and these compounds
Extremely high solubility and affinity for water (soluble
Resolving power) is extremely small. In addition, these compounds have a
The 0 hour half-life temperature must be below 100 ° C
is there. Particularly preferred is a temperature in the range of 50 to 100 ° C.
You. Those having a 10-hour half-life temperature of decomposition of less than 50 ° C.
It is necessary to set the polymerization temperature low.
It leads to a decrease in productivity such as a decrease in heat removal effect,
Industrially produced from azo compounds that decompose at such low temperatures
There are few things built and sold, expensive and economical
And also require frozen storage.
It is not preferable because the size is also large. On the other hand, the 10-hour half-life temperature of decomposition is 100
For those exceeding ℃, increase the polymerization temperature to increase productivity
On the other hand, the obtained copolymer is colored and processed
Thermal stability at the time also worsens, which is not preferable. These phenomena
Remains in the final copolymer, including during polymerization.
Of polymerization initiator may affect product stability
You. Specific examples of the polymerization initiator used include the following: 2,2'-azobis (2-methylbutyroni
Tolyl) [The 10-hour half-life temperature of decomposition is 67 ° C.] Dimethyl 2,2'-azobis (2-methyl
Propionate) [10 hour half-life temperature of decomposition is 66
° C] 1,1'-azobis (cyclohexane-1
-Carbonitrile) [10 hour half-life temperature of decomposition is 88
° C] 1-t-butylazo-1-cyanocyclohexene
Xanth [10-hour half-life temperature of decomposition is 96 ° C]
I can do it. The amount and method of addition of the polymerization initiator depends on the polymerization.
Method of adding aromatic vinyl monomer in the process, initiation of polymerization
Select according to polymerization conditions such as temperature and monomer composition ratio.
Can be. The amount of polymerization initiator added is generally
0.05 to 0.5 part by weight based on 100 parts by weight of monomer
It is good to choose in the range of, preferably, 0.1 to 0.5 weight
The range is in parts by weight. To add the polymerization initiator to the reaction system
Are dissolved in a small amount of monomer and added to other organic solvents.
Addition may be done at any time.
May be added multiple times, or by continuous addition, etc.
Can be. (Suspension and Suspension Aid) In the method of the present invention,
When polymerizing by an aqueous suspension method, a suspending agent and a suspending aid are used.
use. The suspension agent used is polyvinyl alcohol
, Polyvinylpyrrolidone, polyacrylate, poly
Methacrylates, acrylic acid and acrylates
Copolymer or its salt, polyacrylamide, hydro
Water-soluble polymers such as xycellulose and gelatin
It is. These may be one kind or a mixture of two or more kinds.
Good. Hydroxyapatite, calcium carbonate
, Bentonite, talc, tricalcium phosphate, etc.
Machine protective colloid materials can also be used. In the method of the present invention, these suspensions
The amount used depends on the type of monomer and polymerization conditions
Is usually 0.00
05 to 2.0 parts by weight, preferably 0.005 to 0.5 parts by weight
Parts by weight, more preferably 0.01 to 0.1 parts by weight.
You can choose. Used in the method of the invention
As suspension aids, NaBr, NaI, KBr, KI,
NaCl, KCl, NaSO _Four One kind selected from
Can be used in combination of two or more. Amount of suspension aid used
Is 0.02 with respect to 100 parts by weight of the total amount of the raw material monomers.
To 1.0 parts by weight, preferably 0.05 to 0.6 parts by weight
is there. When the amount of the suspending aid is less than 0.02 parts by weight,
The suspension becomes unstable and unfavorable.
If the amount exceeds the part, the molded product obtained from the copolymer
Size (cloudiness) increases, and when immersed in boiling water,
It is not preferable because it is rubbed. (Polymerization conditions)
In the first step of producing the copolymer,
Charge of water as a dispersion medium for a total of 100 parts by weight
The total amount is preferably selected from a range of about 30 to 500 parts by weight.
New About polymerization temperature, polymerization initiator, charged monomer
Depends on the ratio of
Preferably, About polymerization time,
Depends on the ratio, type and amount of polymerization initiator, and polymerization temperature
Therefore, it can be appropriately selected. Polymerization of high nitrile copolymer in the present invention
The method is the same as for ordinary aqueous suspension polymerization except for the choice of polymerization initiator.
There is nothing different from the conditions. Just unsaturated nitrile monomer
Where the monomer reactivity of styrene and aromatic vinyl monomer is different
Therefore, to obtain a high-nitrile resin with a uniform composition,
Care must be taken. It is the composition of the resulting copolymer
Is the monomer composition ratio and monomer reactivity ratio in the reaction system.
From the reaction system with a certain monomer composition ratio
When proceeding, the monomer composition ratio is the azeotropic composition
Unless otherwise indicated, the composition ratio of unreacted monomers and
The composition of the copolymer changes with the progress of the copolymerization reaction
Because. Acrylo, an example of a high nitrile copolymer
Nitrile styrene copolymer produced by aqueous suspension polymerization
Acrylonitrile monomer and styrene
The composition ratio of the acrylonitrile monomer was
% (Azeotrope composition) or more, for example, 96% by weight.
Contains acrylonitrile monomer at the beginning of the copolymerization reaction
A copolymer having a ratio of 65% by weight is obtained. But the monomer anti
Unreacted with the progress of the copolymerization reaction based on the
Of unreacted styrene against the amount of acrylonitrile monomer in water
The proportion of monomer monomers gradually decreases, and
The copolymer formed at the end of the reaction is the acrylonitrile monomer
Very high content, obtained by a series of copolymerization reactions
The composition distribution of the copolymer becomes extremely broad. In addition,
Due to poor compatibility between copolymer components with a wide composition distribution,
The transparency of the finally obtained copolymer becomes poor,
In addition, the coloring and thermal stability of the copolymer due to the non-uniformity of the components
Defects such as deterioration of qualitative properties and physical properties also appear. From the above background, the method of the present invention
Produces a copolymer of the desired composition with a uniform composition and excellent quality.
Monomer composition ratio matching monomer reactivity ratio
The initial charge is performed to start the polymerization, and thereafter, the polymerization reaction
As the reaction progresses, monomers with a high reaction consumption rate are added to the reaction system.
The polymerization is continued until the polymerization reaction is completed.
It is important to keep the monomer composition ratio of the reaction system almost constant.
You. At the end of the polymerization in the first step of the method of the present invention,
Unreacted monomer containing unsaturated nitrile monomer as main component
Steam distillation with steam at temperatures above 100 ° C
A second step of removal from the reaction system. At this time
When the polymerization initiator specified in the
Easily shortened to a state with very little unsaturated nitrile monomer
Reach in time. This is because of the high oil-soluble polymerization initiator
Characteristically, it remains uniformly in the copolymer,
Reacts with monomers that remain in the
it is conceivable that. A similar effect is achieved with peroxide-based
Initiators are also expected, but in this case the resulting copolymer
Are not preferred because they are colored. In addition, conventional high nitrile
AIBN, which has been used for the production of polymers, is also used as a raw material monomer.
It is not preferred because it lacks affinity for and solubility. High nitrile copolymer according to the method of the present invention
Is an unsaturated nitrile monomer component with a uniform composition and a high proportion
Containing, in addition to the usual mechanical properties, transparent
Extremely excellent heat resistance, gas barrier properties, chemical resistance and thermal stability
And the content of residual unsaturated nitrile monomer is
Injection molding, extrusion molding, compression molding, difference
Suitable for manufacturing various molded products and packaging containers by pressure molding
Yes, especially in the food sector. The contents and effects of the present invention will be described below with reference to examples.
As will be described in more detail, the present invention does not go beyond its gist.
The invention is not limited to the following examples. The implementation
Various evaluations of the high nitrile copolymer in Examples and Comparative Examples are as follows.
This was performed according to the method described below. (A) The residual amount remaining in the high nitrile copolymer
Determination of Saturated Nitrile Monomer High nitrile copolymer was converted to dimethylformamide (DMF)
In a predetermined amount, using n-butyl alcohol as an internal standard.
Gas chromatographic method to determine the unsaturated nitrile monomer
Was quantified. Apparatus: Yanagimoto G2800F type gas chromatography;
Lamb: glass 4φ × 3m; filler: PEG-20M 2
5% (Chromosorb W80 / 100); column
Temperature: 120 ° C; Inlet temperature: 200 ° C; Detector temperature:
200 ° C .; Carrier gas: measurement of nitrogen (b) melt flow rate The high nitrile copolymer was placed in a vent using a single screw extruder.
The mixture was kneaded while devolatilizing to form pellets. This page
For the let, JIS K7210 (B method, load 10 kg
f, temperature 220 ° C)
did. (C) Preparation of Test Specimen and Physical Properties Test
Cylinder is manufactured by Resin Kogyo Co., Ltd. FS-120)
-Form a test piece for measuring physical properties at a temperature of 230 ° C.
Was. The following test was performed on this test piece. -Tensile strength: Measured according to JIS K7113.・ Izod impact strength: JISK7110 (with notch)
G). Heat distortion temperature: Measured according to JIS K7207.・ Yellowness (YI value): SM Color Co., manufactured by Suga Test Instruments Co., Ltd.
Measurement using a computer in accordance with JIS K7103.
Was.・ Haze (cloudiness): Directly read hazecon manufactured by Suga Test Instruments Co., Ltd.
Using a computer to measure in accordance with JIS K7105
Was. Example 1 (First step) Stirrer, thermometer, auxiliary additive, heater
300 liter stainless steel with jacket, etc.
Initial preparation of each component with the following formula
The mixture was stirred, and the contents of the reaction system were uniformly suspended.
The total amount of raw material monomers charged in the autoclave is 90
Kg. The charged amount of each component is 100 weights of the total amount of the monomer.
In terms of parts by weight based on parts by weight, acrylonitrile
Monomer: 75.2 parts by weight; styrene monomer: 2.9 parts by weight
Parts; terpinolene: 0.35 parts by weight;
Lacresol: 0.1 parts by weight; water: 100 parts by weight;
Lylic acid-octyl acrylate copolymer: 0.118 weight
Parts; sodium bromide: 0.2 parts by weight. Next, the inside of the autoclave is replaced with nitrogen gas.
After that, the internal temperature was raised to 70 ° C., and while stirring the reaction system,
2,2'-azobi polymerization initiator dissolved in a small amount of styrene
0.12 parts by weight of (2-methylbutyronitrile)
Nitrogen gas is injected from the agent addition device to start the copolymerization reaction.
Started. Immediately after the start of the polymerization, the styrene monomer 2
1.9 parts by weight, terpinolene 0.15 parts by weight, and polymerization
Initiator 2,2'-azobis (2-methylbutyronitrile
G) A mixed solution consisting of 0.23 parts by weight is added at a constant speed to 4.5.
Over time, it was continuously added to the reaction system. Do you start the reaction
From the beginning of the reaction to 2 hours.
The temperature was kept at 78 ° C, and the internal
Was heated to 90 ° C. (Second step) Conversion of styrene monomer to reaction system
Immediately after the end of continuous addition, unreacted monomers are steam distilled.
The internal temperature is raised to 140 ° C while removing from the reaction system by
The reaction was completed 7 hours after the start of steam distillation. Steaming
Four hours after starting the gas distillation method, a small amount of
A sample was taken. Then, the internal temperature of the autoclave is reduced.
After cooling, the copolymer and water were separated, washed with water, and dried.
kg of a beaded copolymer was obtained. (Evaluation test) Acrylo of the obtained copolymer
The nitrile content was 71.2% by weight. Steam steaming
Of acrylonitrile in the sample copolymer at 4 hours
Acrylonitrile remaining in the copolymer obtained quantitatively
Of the copolymer, pelletize the obtained copolymer, and inject
Test pieces were prepared by the shape method, and various physical property tests were performed.
Table 1 shows the results. Example 2 (First Step) In the first step described in Example 1, polymerization was carried out.
The initiator is dimethyl 2,2'-azobisisobutyrate
And 0.14 parts by weight of the polymerization initiator was added thereto.
Except for the continuous addition of 0.25 parts by weight,
The reaction was performed in the same manner. (Second Step) The second step described in Example 1
In the same manner, 76.5 kg of a beaded copolymer
Got. (Evaluation test) Acrylonitrile content of the obtained copolymer
The rate was 69.5% by weight. The fourth hour of steam distillation
Determination of acrylonitrile in sample copolymer
Of acrylonitrile remaining in the copolymer
The copolymer obtained is pelletized and tested by injection molding.
Test pieces were prepared and various physical property tests were performed. The results are shown in Table 1.
You. Example 3 (First step) Stirrer, thermometer, auxiliary additive, heating
5 liter stainless steel male with jacket, etc.
Initially charge each component to the autoclave with the following formulation.
After stirring, the contents of the reaction system were uniformly suspended. Oh
The total amount of the raw material monomers charged in the autoclave is 1.5
Kg. The charged amount of each component is 100 weights of the total amount of the monomer.
In terms of parts by weight based on parts by weight, acrylonitrile
Monomer: 73 parts by weight; styrene monomer: 2.4 parts by weight;
-Pinolene: 0.8 parts by weight;
Water: 90 parts by weight; acrylic acid
Octyl acrylate copolymer: 0.04 parts by weight;
Thorium: 0.2 parts by weight. Next, the inside of the autoclave is replaced with nitrogen gas.
Then, raise the internal temperature to 105 ° C and stir the reaction system.
One-t-butyl polymerization initiator dissolved in a small amount of styrene
0.16 parts by weight of luazo-1-cyanocyclohexane is
Press-in with nitrogen gas from the auxiliary agent addition device to initiate the copolymerization reaction.
Started. From the start of the polymerization, styrene unit
Start the continuous addition of the monomer, take 4.5 hours at a constant rate
24.6 parts by weight. During this time, the reaction temperature is 3 o'clock
After a while, the internal temperature was raised to 115 ° C.,
The internal temperature was raised to 140 ° C. over time. (Second step) Conversion of styrene monomer to reaction system
After the continuous addition, unreacted monomer is immediately
Is removed from the reaction system by steam distillation in 7 hours.
The reaction was completed. Four hours after starting the steam distillation method
A small sample was extracted with. Then autoclay
Cool the inside temperature, separate the copolymer and water, wash with water and dry
Thus, 1.3 kg of a beaded copolymer was obtained. (Evaluation Test) Acrylo of the Copolymer Obtained
The nitrile content was 66% by weight. Steam distillation 4
Determination of acrylonitrile in sample copolymer at time
Amount of acrylonitrile remaining in the obtained copolymer
Amount, and pelletize the obtained copolymer, injection molding method
Specimens were prepared in accordance with the above, and various physical property tests were performed. result
Are shown in Table 1. Example 4 (First Step) In the first step described in Example 1,
Minutes, the total amount of monomers was 100 parts by weight.
In terms of parts by weight, acrylonitrile monomer: 60
Parts; styrene monomer: 4.8 parts by weight; terpinolene:
0.8 parts by weight; t-butyl paracresol: 0.0
4 parts by weight; water: 70 parts by weight; acrylic acid-acrylic acid
Cutyl copolymer: 0.03 parts by weight; sodium bromide:
Instead of 0.3 parts by weight, continuous addition of styrene monomer
Except that the amount used was changed to 35.2 parts by weight.
The reaction was performed in the same manner as described above. (Second Step) The second step described in Example 1
In a similar manner, 77.4 kg of a beaded copolymer
Got. (Evaluation test) Acrylonitrile content of the obtained copolymer
The rate was 54% by weight. Sun for 4 hours of steam distillation
Determination of acrylonitrile in pull copolymer, obtained copolymer
Determination of acrylonitrile remaining in polymer
The copolymer is pelletized, and the test piece is
Were prepared and various physical property tests were performed. Table 1 shows the results. Comparative Example 1 (First Step) In the first step described in Example 1, polymerization was carried out.
The initiator is 2,2'-azobisisobutyronitrile (AI
BN), and 0.1 parts by weight of this was initially added, and the polymerization was started.
Except that instead of continuously adding 0.2 parts by weight of the initiator,
The reaction was carried out in the same manner as in the same example. (Second Step) The second step described in Example 1
In a similar manner, 73.8 kg of beaded copolymer
Got. (Evaluation test) Acrylonitrile content of the obtained copolymer
The rate was 70.5% by weight. The fourth hour of steam distillation
Determination of acrylonitrile in sample copolymer
Of acrylonitrile remaining in the copolymer
The copolymer obtained is pelletized and tested by injection molding.
Test pieces were prepared and various physical property tests were performed. The results are shown in Table 1.
You. Comparative Example 2 (First Step) In the first step described in Example 1, polymerization was carried out.
The initiator is m-oil oil peroxide, which is
0.1 parts by weight of initial addition, 0.2 parts by weight of the same polymerization initiator
Instead of continuous addition, add
The temperature was raised to 85 ° C, and the internal temperature was maintained for 2 hours from the start of the reaction.
The temperature was maintained at 85 ° C, and the internal temperature was raised to 1
The same method as in the same example except that the temperature was raised to 05 ° C
The reaction was carried out. (Second Step) The second step described in Example 1
In a similar manner, a 75 kg beaded copolymer was obtained.
Was. (Evaluation test) Acrylonitrile content of the obtained copolymer
The rate was 69.5% by weight. The fourth hour of steam distillation
Determination of acrylonitrile in sample copolymer
Of acrylonitrile remaining in the copolymer
The copolymer obtained is pelletized and tested by injection molding.
Test pieces were prepared and various physical property tests were performed. The results are shown in Table 1.
You. Comparative Example 3 (First Step) In the first step described in Example 3, polymerization was carried out.
The initiator was di-tert-butyl peroxide, which was
Instead of adding 0.15 parts by weight, the reaction temperature
Takes 3 hours from 105 ℃ to 130 ℃
The internal temperature was raised to 145 ° C over 1.5 hours.
Except that the temperature was raised to
Was done. (Second Step) The second step described in Example 3
In the same way, 1.35 kg of a beaded copolymer
Got. (Evaluation test) Acrylonitrile content of the obtained copolymer
The rate was 68% by weight. Sun for 4 hours of steam distillation
Determination of acrylonitrile in pull copolymer, obtained copolymer
Determination of acrylonitrile remaining in polymer
The copolymer is pelletized, and the test piece is
Were prepared and various physical property tests were performed. Table 1 shows the results. Comparative Example 4 (First Step) In the first step described in Example 3, polymerization was carried out.
The initiator is 2-phenylazo-4-methoxy-2,4-di
Methylvaleronitrile was added and 0.2 parts by weight of this was added.
Alternatively, the reaction temperature is raised from 105 ° C.
It took 3 hours to raise the internal temperature to 130 ° C, and then
In addition to raising the internal temperature to 145 ° C in 1.5 hours
Performed the reaction in the same manner as in the same example. (Second Step) The second step described in Example 3
In a similar manner, 1.26 kg of a beaded copolymer
Got. (Evaluation test) Acrylonitrile content of the obtained copolymer
The rate was 67.1% by weight. The fourth hour of steam distillation
Determination of acrylonitrile in sample copolymer
Of acrylonitrile remaining in the copolymer
The copolymer obtained is pelletized and tested by injection molding.
Test pieces were prepared and various physical property tests were performed. The results are shown in Table 1.
You. [Table 1] The abbreviations in Table 1 are as follows. AN: acrylonitrile 3: 2,2'-azobis (2-methylbutyronitrile
4) Dimethyl 2,2′-azobisisobutyrate 6: 1-tert-butylazo-1-cyanocyclohexane AIBN: 2,2′-azobisisobutyronitrile m-toluoyl PO: m-toluoyl par Oxide DTBPO: di-tert-butyl peroxide V-19: 2-phenylazo-4-methoxy-2,4-
Dimethylvaleronitrile From Table 1, the following becomes clear. (1) According to the method of the present invention, high nitrile
Of acrylonitrile remaining in the copolymer
Reduced and good physical properties were obtained.
You. (See Examples 1-4). (2) On the other hand, the polymerization opening defined by the method of the present invention is
High nitrile copolymers produced from things other than the initiator,
Remains in high nitrile copolymer 4 hours after steam distillation
The amount of acrylonitrile is significantly higher, and
The degree of yellowness (YI value) after 7 hours of distillation was compared with that of Example
(See Comparative Examples 1 to 4)
See). According to the production method of the present invention, a high nitrile copolymer
Significantly reduces residual unsaturated nitrile monomer in the body
Can be without coloring problems, gas barrier and chemical resistant
Industrially advantageous production of copolymers with excellent properties, etc.
Has a particularly remarkable effect,
The utility value of is extremely large.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-1710 (JP, A) JP-A-54-6091 (JP, A) JP-A-4-120153 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C08F 6/00-6/28 C08F 4/04 C08F 212/00 C08F 220/42

Claims (1)

(57) [Claim 1] 40 to 90% by weight of an unsaturated nitrile monomer, 10 to 60% by weight of an aromatic vinyl monomer, and a vinyl monomer copolymerizable therewith 0 to 20% by weight is represented by the following formula 1, and the 10-hour half-life temperature of decomposition is 10:
It comprises a first step of polymerizing by an aqueous suspension method using an azo polymerization initiator having a temperature of 0 ° C. or lower, and a second step of removing unreacted monomers by steam distillation at a temperature of 100 ° C. or higher. A method for producing a high nitrile copolymer _. Embedded image (Wherein X ₁ and X ₂ are —CN groups or one of them is an alkyl group, R ₁ , R ₂ , R ₃ and R ₄ are alkyl groups having 1 or more carbon atoms and R ₁ , R ₂ , R ₃ and R ₄ Has a total carbon number of 6 or more (R ₁ and R ₂ ,
Wherein R ₃ and R ₄ contain an alicyclic alkyl group linked by a covalent bond) or X ₁ and X _{2 are} —COOR
(R is a methyl group) and R ₁ , R ₂ , R ₃ , and R ₄ are azocarboester compounds having an alkyl group having 1 or more carbon atoms. )