JPH0356241B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an asymmetric peroxydicarbonate-containing composition and its use in compositions for polymerizing or copolymerizing ethylenically unsaturated monomers. In recent years, diisopropyl peroxydicarbonate (hereinafter abbreviated as IPP) has been mainly used as an initiator for suspension polymerization of vinyl chloride monomers, but the unique disadvantages of IPP have become apparent.
Improvement was desired. In other words, although IPP has a high reaction rate in a low temperature range, it has poor thermal stability, and since the pure product is a solid and has poor compatibility with solvents, there is always a danger in handling it. Was. In addition, there was initial coloring of the polymer, making it unsatisfactory as a vinyl chloride monomer polymerization initiator. In contrast, dialkoxy-substituted alkyl peroxydicarbonates have been offered as initiators to improve the drawbacks of IPP. For example, di3-
Methoxybutyl peroxydicarbonate (hereinafter
The main ones include MC), diethoxyethyl peroxydicarbonate (hereinafter abbreviated as EEP), and dimethoxyisopropyl peroxydicarbonate. Furthermore, there is di-2-(2-ethoxyethoxy)ethyl peroxydicarbonate. With the advent of these improved initiators, IPP
Although the disadvantages of handling risks and the initial coloration of vinyl chloride monomers have been improved, dialkoxy-substituted alkyl peroxydicarbonates have significantly higher hydrolyzability and water solubility than IPP. Therefore, the initiator activity during polymerization is poor in sustainability.
Furthermore, it had the disadvantage of low solubility in aliphatic hydrocarbons at low temperatures. These known dialkoxy-substituted alkyl peroxydicarbonates have excellent start-up in the early stage of polymerization, do not have abnormal polymerization heat peaks in the late stage of polymerization,
It is an initiator that allows easy control of polymerization, and the initial coloring of the resulting polymer is also very good. However, in order to take advantage of these features of dialkoxy-substituted alkyl peroxydicarbonates, these two drawbacks must be addressed. In other words, due to its high hydrolyzability, it has a lower ability to retain activity, especially in the summer when the water temperature is high, and it lacks compatibility with aliphatic hydrocarbon solvents due to its unique chemical structure with polar groups. Improvements have been desired due to safety and health problems that require the use of aromatic solvents as inert diluents. As a result of extensive studies, the present inventors found that an asymmetric peroxydicarbonate-containing composition produced from an alkoxyalkyl chloroformate and an alkyl chloroformate overcomes these drawbacks of dialkoxyalkyl peroxydicarbonates. We have discovered that improvements can be made and have arrived at the present invention. That is, the present invention has the general formula [] {In the formula, R ₁ is CuH ₂ n having a linear or branched chain
+1 (n=1-4), _R2 is linear or branched _CuH2n (n=1-10) or ( _CH2-
CHR4O )n- _CH2 - _CHR4 (n=1-2, _R4 =H
or CH ₃ ), R ₃ is a linear or branched saturated or unsaturated hydrocarbon having 36 or fewer carbon atoms, a halogen-containing saturated or unsaturated hydrocarbon, a (substituted) aromatic compound, a (substituted) cyclic alkyl compound, or It is a heterosegmental cyclic compound. } Asymmetric peroxydicarbonate represented by the general formula [] (In the formula, R ₁ and R ₂ are as defined above.) A dialkoxyalkyl peroxydicarbonate represented by the general formula [] (In the formula, R ₃ has the same meaning as defined above.) A composition for polymerizing an ethylenically unsaturated monomer, comprising a dialkyl peroxydicarbonate represented by the following formula. It is. The present invention provides two types of chloroformates including an asymmetric peroxydicarbonate represented by the following general formula [], namely:

It is characterized by being a mixture containing three types of peroxydicarbonates simultaneously, which is synthesized by reaction with [Formula] and usually exhibits a homogeneous liquid state. R ₁ ; CnH ₂ n+1 (n=1
~4) _R2 ; _CnH2n having a straight chain or a branch (n=1~
10) or ( _CH2 - _CHR4O )n- _CH2-
CHR4 (n=1-2, _R4 =H or _CH3 ) Examples of the alkoxyalkyl group (R1 _- O- _R2 ) include 2-methoxymethyl, 2-ethoxyethyl, 2-isopropoxyethyl, methoxy Isopropyl, ethoxyisopropyl, n-propoxyisopropyl, isopropoxyisopropyl, n-butoxyisopropyl, isobutoxyisopropyl, sec-butoxyisopropyl,
tert-butoxyisopropyl, 3-methoxybutyl, 3-methyl, 3-methoxybutyl, 2-
(2-methoxyethoxy)ethyl, 2-(2-ethoxyethoxy)ethyl, 2-(2-n-butoxyethoxy)ethyl, and the like. R ₃ ; Represented by a linear or branched saturated or unsaturated hydrocarbon having 36 or fewer carbon atoms, a halogen-containing saturated or unsaturated hydrocarbon, a (substituted) aromatic compound, a (substituted) cyclic alkyl compound, or a heterocyclic compound. It will be done. Examples of _R3 include n-propyl, isopropyl,
n-butyl, sec-butyl, 1-methyl-n-butyl, 1-methyl-n-hexyl, 2-ethyl-
Examples include n-hexyl, decyl, myristyl, cetyl, stearyl, aryl, crotyl, propargyl, benzyl, cyclohexyl, 4-tertbutylcyclohexyl, diisobornyl, 2-phenoxyethyl, and the like. Specific examples of the asymmetric peroxydicarbonate represented by the general formula [] used in the present invention are 3-methoxybutyl n-propyl peroxydicarbonate, 3-methoxybutyl isopropyl peroxydicarbonate, and 3-methoxybutyl n-propyl peroxydicarbonate. n
-Butyl peroxydicarbonate, 3-methoxybutyl Sec-butyl peroxydicarbonate, 3-methoxybutyl 2-ethylhexyl peroxydicarbonate, 3-methoxybutyl
Myristyl peroxydicarbonate, 3-methoxybutyl aryl peroxydicarbonate, 3-methoxybutyl benzyl peroxydicarbonate, 3-methoxybutyl 2-chloroethyl peroxydicarbonate, 3-methoxybutyl 4-tert Butyl cyclohexyl peroxydicarbonate, 2-ethoxyethyl n-propyl peroxydicarbonate, 2-ethoxyethyl isopropyl peroxydicarbonate, 2-ethoxyethyl n-butyl peroxydicarbonate, 2-ethoxyethyl sec -Butyl peroxydicarbonate, 2-ethoxyethyl 2-ethylhexyl peroxydicarbonate, 2-ethoxyethyl 4-tertbutylcyclohexyl peroxydicarbonate, 2-(2
-ethoxyethoxy)ethyl 2-ethylhexyl peroxydicarbonate, 2-methoxyisopropyl isopropyl peroxydicarbonate, n-butoxyisopropyl sec-butyl peroxydicarbonate and n-butoxyisopropyl 2-ethylhexyl peroxydicarbonate etc. Further, a specific example of the dialkoxyalkyl peroxydicarbonate represented by the general formula [] is di-3
-methoxybutylperoxydicarbonate, di2-ethoxyethyldicarbonate, di2-(2
-ethoxyethoxy)ethylperoxydicarbonate, di2-methoxyisopropylperoxydicarbonate, di-n-butoxyisopropylperoxydicarbonate, and the like. Furthermore, specific examples of the dialkyl peroxydicarbonate represented by the general formula [] are di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, Di2-ethylhexyl peroxydicarbonate, dimyristyl peroxydicarbonate, diaryl peroxydicarbonate, dibenzyl peroxydicarbonate, di2
-Chloroethyl peroxydicarbonate, di4
-tertbutylcyclohexyl peroxydicarbonate, di-n-propylperoxydicarbonate, diisopropylperoxydicarbonate,
di-n-butyl peroxydicarbonate, di-sec
-butyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-4-
tert-butylcyclohexyl dicarbonate, di2
-Ethylhexyl peroxydicarbonate, diisopropyl peroxydicarbonate, disec
-butyl peroxydicarbonate and di-2-ethylhexyl peroxydicarbonate. The compositions of the present invention contain about 20 to about 70 mole percent of asymmetric peroxydicarbonate (A) and about 15 mole percent of each asymmetric peroxydicarbonate (A).
about 45 mole percent of two symmetrical peroxydicarbonates, namely alkoxyalkyl peroxydicarbonates. and dialkyl peroxydicarbonate

Compositions containing the formula are preferred. The composition of the present invention comprises two chloroformates of different reactivity, namely:

[Formula] and

It can be produced by treating [Formula] with a mixed aqueous solution of an alkaline substance such as caustic soda and hydrogen peroxide at a temperature range of about 0 to 20°C in an aqueous solution. For this purpose, it is essential to introduce an interfacial substance into the reaction system. The surfactants include various cationic, anionic, nonionic, and zwitterionic surfactants, as well as phase transfer catalysts. The required amount of these additions is approximately
It ranges from 0.01% to about 15.0% by weight. The optimum time for addition is before the chloroformate is added dropwise. That is, to synthesize the composition of the present invention, water, an inert diluent if necessary, and sodium carbonate are placed in a suitable reaction vessel, and hydrogen peroxide solution is added at 10°C or lower under external cooling. good. After an interfacial agent is then added to emulsify the system, a mixture of two chloroformates and an aqueous sodium hydroxide solution are simultaneously added dropwise to the reaction mixture. The reaction mixture is then separated into two layers, the aqueous phase is removed, a cold aqueous sodium chloride solution is added and the mixture is separated again, then dry magnesium sulfate is added and the salts are removed by filtration. The reaction mixture thus obtained contains the desired main components. More preferred compositions of the invention include about 50 mole percent of the asymmetric peroxydicarbonate (A) and about
25 mole percent of two symmetrical peroxydicarbonates, namely dialkoxyalkyl peroxydicarbonates; and dialkyl peroxydicarbonate

It has [Formula]. To prepare this composition it is necessary to add equal molar amounts of the two chloroformates to the reaction mixture, thus 2 moles of the alkoxyalkyl chloroformate.

[Formula] and 2 moles of alkyl chloroformate

Approximately 2 moles of the unsymmetrical peroxydicarbonate (A) and 1 mole each of two symmetrical peroxydicarbonates, namely dialkoxyalkyl peroxydicarbonates, are prepared by reacting a mixture of [formula] with and dialkyl peroxydicarbonate

[Formula] can be obtained. It goes without saying that it may be considered desirable to obtain mixtures of symmetric and asymmetric peroxydicarbonates containing a greater proportion of symmetric peroxydicarbonates; such mixtures simply,
A molar excess of chloroformate is easily obtained by reacting different molar amounts of two chloroformates such that a larger proportion of symmetric peroxydicarbonate is formed. The desired higher symmetric peroxydicarbonate concentration can also be obtained by incorporating additional symmetric peroxydicarbonate into the reaction mixture obtained by simply reacting equal molar amounts of two chloroformates. It is also clear that Although the composition of the present invention can be produced as a pure product, it is also possible to produce it using aromatic/aliphatic hydrocarbons and plasticizers as inert solvents.It is noteworthy that this composition can be produced in a low temperature range. The substance has excellent compatibility with aliphatic hydrocarbon solvents. Originally, dialkoxyalkyl peroxydicarbonates alone have poor compatibility with aliphatic hydrocarbon solvents and tend to cause phase separation, but the composition of the present invention can be used not only at -20°C but also in dry ice methanol. Some products that exhibit a homogeneous liquid state even at -78°C, which can be obtained using this system, have been developed. Regarding the hydrolyzability, as can be seen from the examples, the hydrolyzability of the asymmetric peroxydicarbonate is close to that of the dialkyl peroxydicarbonate, and is significantly improved. It was discovered that the hydrolysis resistance was further improved than not only dialkoxyalkyl peroxydicarbonate but also a simple mixture of dialkoxyalkyl peroxydicarbonate and dialkyl peroxydicarbonate. . It is also clear that the hydrolyzability of the compositions of the present invention is also significantly improved. It has also been found that the composition of the present invention has a significantly lower decomposition temperature than expected from conventional symmetric peroxydicarbonates. The polymerization or copolymerization method of ethylenically unsaturated monomers varies depending on the type of monomer, polymerization conditions, polymerization equipment, etc., but the polymerization reaction using the composition of the present invention uses the improved initiator. Other than that, the reaction is carried out according to a conventional polymerization reaction. In the method of the present invention, the amount of this composition used is approximately the same as that of known peroxides; for example, in the case of vinyl chloride polymerization, the amount of this composition used is from 0.01 to 0.35% by weight based on the monomer. range. A polymerization temperature within the range of 35°C to 60°C is appropriate and effective. In the method of the present invention, this composition can be used alone or in combination with other peroxides of different activity, such as lauroyl peroxide.
It can also be used in combination with high-temperature active peroxides such as tert-butyl peroxypivalate, and even lower-temperature active acetylcyclohexane sulfonyl peroxides and 2,4,4-trimethylpentyl peroxyphenoxy acetate. It is also possible to bring out the effect. In the method according to the present invention, the main polymerizable ethylenically unsaturated monomers are vinyl chloride, vinylidene chloride, vinyl acetate, acrylic esters, methacrylic esters, alkylene glycol bis(aryl carbonate), acrylonitrile. , styrene, α-methylstyrene, ethylene, etc., but are not limited to these examples, and can also be used as a polymerization initiator for single or copolymerization reactions. Even when used alone, this composition as a polymerization initiator according to the present invention has improved hydrolysis resistance.
It has excellent persistence of polymerization activity, suppresses a decrease in activity in the latter half of polymerization, and has become possible to suppress deactivation before the start of polymerization as much as possible. Further, like the alkoxyalkyl peroxydicarbonates, the polyvinyl chloride produced by the composition of the present invention maintains thermal stability and has good initial coloring properties. Examples will be described in detail below to facilitate understanding of the present invention, but the present invention is by no means limited to this scope. Example 1 1-1 Production of asymmetric peroxydicarbonate-containing composition (diluted product with a concentration of 70%) Into a tall beaker equipped with a thermometer, a stirring blade, a dropping funnel, and a jammer plate, 49.
g of IP-1620 solvent as aliphatic hydrocarbon diluent, 242 ml of water, 55.8 g of sodium carbonate,
25.1 g of hydrogen peroxide (60%) was added, followed by polyoxyethylene alkyl phenol ether (Emulgen 906;
1.5 g of HLB=10.8) was added, and stirring was continued for 5 minutes to emulsify the system, which was maintained at 5°C. Next, over a period of 30 minutes, 79.5 g of 2-ethylhexyl chloroformate was added.
A mixture of 68.0 g of 3-methoxybutyl chloroformate and 68.0 g of 3-methoxybutyl chloroformate was mixed well in advance, and at the same time, 131.0 g of an aqueous sodium hydroxide solution (25%) was added dropwise, and the temperature was maintained at 2 to 9°C for 30 minutes. The reaction was allowed to proceed with stirring. Next, the reaction product was allowed to stand in a separatory funnel, and the resulting aqueous phase was separated and removed. Meanwhile, the peroxide phase was again transferred to a tall beaker, washed twice with 20% saline, and dehydrated over dry magnesium sulfate.
After evaporation, 168 g of asymmetric peroxydicarbonate-containing composition was obtained. A purity of 69.1% was obtained by iodometry analysis for active oxygen (corrected yield 91%).
The specific gravity of the obtained product at 10°C was 0.947, and the refractive index at 10°C was 1.4346. High performance liquid chromatography analysis revealed that there were four main peaks, which were sequentially divided into di-3-methoquibutylperoxydicarbonate (MC), asymmetric 3-
Methoxybutyl 2-ethylhexyl peroxydicarbonate (MC・EHP), di2-ethylhexyl peroxydicarbonate (EHP), IP-
1620 solvents and were identified respectively. At the same time, based on the quantitative analysis results, the component ratios were as follows. MC/MC・EHP/EHP=22/54/24 (%) Furthermore, although MC does not show compatibility with aliphatic hydrocarbon solvents, the obtained composition is an aliphatic hydrocarbon solvent. It was revealed that it was freely soluble in IP-1620 solvent. 1-2 Half-life temperature measurement The half-life temperature of the asymmetric peroxydicarbonate-containing composition obtained in Example 1-1 was measured in a 0.2 mol/benzene solution. The result
The values of MC and EHP are shown below.

[Table] Examples 2 to 5 According to Example 1, asymmetric peroxydicarbonate-containing compositions were produced by combining various chloroformates. Example 6 An asymmetric peroxydicarbonate-containing composition was synthesized under the same conditions as in Example 1 except for Emulgen 906. A product with a low yield and particularly a very high chlorine content was obtained, demonstrating the usefulness of a substance with surfactant action. The manufacturing conditions and results of Examples 1 to 6 are summarized in Table 1.

【table】

[Table] Examples 7 to 11 Further, Table 2 shows the results of producing asymmetric peroxydicarbonate-containing compositions using various combinations of chloroformates under the same conditions as in Example 1.

【table】

[Table] Example 12 Hydrolysis rate measurement of asymmetric peroxydicarbonate-containing composition (30°C) MC alone, EHP alone, 50/50 of MC and EHP
The degree of hydrolysis of the mixture and the MC/EHP asymmetric peroxydicarbonate-containing composition was measured and compared. Operation procedure 1 In each 500 ml conical beaker, charge 1.5 g of pure MC, EHP, MC/EHP mixture, asymmetric carbonate-containing material (manufactured in Example 1) and 298.5 g of deionized water, and cool with ice water. The mixture was strongly stirred with a stirrer for 30 seconds at a temperature of 2 to 5°C. 2 While stirring, take a sample with a 30 ml whole pipette and transfer to a 100 ml separating funnel. Next, 5 ml of n-hexane was added, the container was tightly stoppered, and the peroxide content was extracted by shaking vigorously. 3. Each conical beaker was heated and kept at an internal temperature of 30°C for 2 hours with stirring. 4 After 1 hour and 2 hours, the reaction product was sampled and extracted with n-hexane. 5 Analyze the residual peroxide content of the extract using high performance liquid chromatography and compare it with the peak area of the blank (operation 2).
The hydrolysis rate was determined from the degree of decrease. Similarly, the extract was analyzed by iodometry, and hydrolysis was determined from the degree of decrease in the amount of active oxygen. Example 13 According to the operating procedure of Example 12, di-3-methoxybutyl peroxydicarbonate (MC)/di-
n-butyl peroxydicarbonate (NBP)
The hydrolysis rate of the system was measured at 30°C. Example 14 Following the operating procedure of Example 12, diethoxyethyl peroxydicarbonate (EEP)/di2-
The hydrolysis rate of ethylhexyl peroxydicarbonate (EHP) system was measured at 30°C. The results of Examples 12, 13, and 14 are summarized in Table 3.

【table】

[Table] As is clear from Table 3, the asymmetric peroxydicarbonate-containing composition of the present invention is dialkoxyalkyl peroxydicarbonate.
Compared to MC or EEP, the hydrolysis rate was reduced to less than 1/2 in both cases, confirming that the hydrolysis resistance was significantly improved. It is clear from the results shown in Table 3 that this improvement in hydrolyzability is due to the extremely low hydrolyzability of the asymmetric peroxydicarbonate component. Example 15 Polymerization of vinyl chloride A vinyl chloride monomer was polymerized using the asymmetric peroxydicarbonate-containing composition (MC/EHP) of the present invention using a glass-lined rotary stirring autoclave with a capacity of 1. Examples 16, 17, 18 According to Example 15, polymerization of vinyl chloride using other asymmetric peroxydicarbonate-containing compositions was carried out. Comparative Examples 1, 2, 3 According to Example 15, vinyl chloride was polymerized using MC, EHP, and IPP, respectively. Examples 15, 16, 17, 18 and Comparative Examples 1, 2, 3
The polymerization conditions and results are summarized in Table 3.

【table】

[Table] As shown in Table 4, the vinyl chloride polymer obtained by the asymmetric peroxydicarbonate-containing composition of the present invention is compared to the polymer obtained using dialkoxyalkyl peroxydicarbonate as an initiator. The physical properties are the same or better,
It is also clear that the initiator of the present invention is more active at lower temperatures and has a higher initial polymerization rate than dialkoxyalkyl peroxydicarbonates, confirming that the polymerization properties are significantly improved.

Claims (1)

[Claims] 1. General formula [] {In the formula, R ₁ is linear or branched CnH ₂ n
+1 (n=1-4), _R2 is linear or branched _CnH2n (n=1-10) or ( _CH2-
CHR ₄ 0) n-CH ₂ -CHR ₄ (n=1-2, R ₄ =H
or CH ₃ ), R ₃ is a linear or branched saturated or unsaturated hydrocarbon having 36 or fewer carbon atoms, a halogen-containing saturated or unsaturated hydrocarbon, a (substituted) aromatic compound, a (substituted) cyclic alkyl compound, or It is a heterosegmental cyclic compound. } Asymmetric peroxydicarbonate represented by the general formula [] (In the formula, R ₁ and R ₂ are as defined above.) A dialkoxyalkyl peroxydicarbonate represented by the general formula [] (In the formula, R ₃ has the same meaning as defined above.) A composition for polymerizing an ethylenically unsaturated monomer, comprising a dialkyl peroxydicarbonate represented by the following formula.