JPH032375B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel diacyl type polymeric peroxide having a branched hydrocarbon group in the molecule, which is used as a free radical polymerization initiator for vinyl type monomers. BACKGROUND ART Diacyl-type polymeric peroxides obtained by polycondensation reaction of dibasic acid chlorides and sodium peroxide are conventionally known. That is, diacyl-type polymeric peroxide from phthalate chloride and sodium peroxide is described in Ber. vol. 27, item 1510 (1894);
The American Chemical Society [J.
Amer.Chem.Soc] Vol. 68, p. 534 (1646), by the reaction of oxalate chloride with sodium peroxide, the corresponding diacyl-type polymeric peroxide was also produced in Chemical Abstracts [Chem.Abst] 60.
Vol. 5293d (1964) and Vol. 10892e (1964), the following general formula is obtained by the reaction of an aliphatic dibasic acid chloride with sodium peroxide. (where n is 2 to 10 and X is 16 to 35) A diacyl type polymeric peroxide has been reported. Further, JP-A-53-149918 discloses a diacyl type polymeric peroxide having an ester bond obtained by reacting an acid chloride having an ester bond in the molecule with sodium peroxide. These diacyl type polymeric peroxides are also known to be useful as free radical polymerization initiators (hereinafter referred to as polymerization initiators) for vinyl type monomers. For example, according to Chemical Abstracts (Chem.Abst) Vol. 67, 54445a (1967), when the above-mentioned polymeric peroxide is used as a polymerization initiator, a polymer with twice the molecular weight can be obtained compared to when benzoyl peroxide is used. Also, Chemical Abstracts (Chem.Abst) Volume 84,
136120f (1976) that when the above polymeric peroxide was used as a polymerization initiator for vinyl acetate, a polymer with a larger molecular weight and a lower degree of branching was obtained compared to when benzoyl peroxide was used. It is also reported in Koka Shi, Vol. 69, p. 718 (1966) that a styrene-methyl methacrylate graft polymer was obtained when poly(phthaloyl peroxide) was used. Although the known diacyl polymer peroxides are useful polymerization initiators, they have the following drawbacks. (1) It is sensitive to shock and friction and is an explosive compound (see Chemical Abstracts, Vol. 59, 7651 (1963)). (2) Due to its low solubility in organic solvents, vinyl It cannot be used industrially as a polymerization initiator because it does not dissolve or is only slightly soluble in type monomers (Koka Zasshi, Vol. 69, p. 718 (1966) and Chemical Abstracts [Chem.Abst]).
See vol. 64, 15989g (1968). This is related to the initiator effect; if the solubility is low, the initiator effect will be low if it is used as a polymerization initiator. The diacyl type polymer peroxide having an ester bond in the molecule is excellent in improving the above two points. However, it has the following drawbacks. That is, the production of an acid chloride having an ester bond in the molecule as a raw material consists of a two-step process and must be carried out under a stream of dry air or dry nitrogen, so the process is long.
Moreover, it is industrially disadvantageous in that it requires special equipment. The present inventors have solved these various drawbacks, and have developed a polymerization initiator that is useful as a polymerization initiator, is safe to manufacture and handle, rapidly dissolves in vinyl monomers, and is suitable for industrial use as an efficient initiator. As a result of research in search of diacyl-type polymeric peroxides that are valuable in terms of their value, they discovered a new diacyl-type polymeric peroxide in which a branched hydrocarbon group was introduced into the molecule, leading to the completion of the present invention. That is, the present invention provides the following general formula The average molecular weight consisting of the structural unit (1) represented by
It is a diacyl type polymeric peroxide with a molecular weight of 2,000 to 17,000. The diacyl polymer peroxide of the present invention can be produced by the following method. That is, 7,12-dimethyloctadecane-1,20 dicarboxylic acid chloride is added little by little to an aqueous solution of a peroxidant such as sodium peroxide and potassium peroxide, and the reaction is allowed to occur under stirring. After the reaction is completed, the reaction waste liquid is separated. It can be easily obtained by The reaction conditions are the same as for ordinary diacyl peroxides, the reaction temperature is -10 to 40°C, preferably 0 to 15°C, and the reaction time is 0.25 to 5 hours.
Preferably it is 0.5 to 2 hours. Further, the molar ratio of the raw material dibasic acid chloride to the peroxidant is 1:0.7 to 3, and the concentration of the aqueous solution of the peroxidant is 1 to 15% by weight, preferably 2 to 10% by weight.
It is. The diacyl-type polymeric peroxide of the present invention produced as described above is a transparent viscous liquid and is composed of the above-mentioned structural unit (1), in which the arrangement of the structural unit (1) is head-to-head or head-to-head. - A so-called random condensation polymer with tail bonds and an average molecular weight of 2000~
It is 17000. The diacyl-type polymeric peroxide of the present invention has -C of diacyl as determined by infrared absorption spectrum.
=O bond and C-O bond and -O- of peroxide
O-bonds were confirmed, and nuclear magnetic resonance spectroscopy revealed -CH ₃ , -CH ₂ -,

[Formula] and

It is identified by clarifying the structure of [Formula], and its constituent units are determined. Further, the average molecular weight is determined by the VPO method (using a model 117 molecular weight measuring device manufactured by Corona Denki Co., Ltd.). Furthermore, the amount of active oxygen is determined by iodometric titration. The diacyl polymer peroxide of the present invention obtained as described above has many advantages as follows. (1) It is insensitive to impact and friction, has low explosiveness, and is safe to manufacture and handle. (2) Compared to conventional diacyl-type polymeric peroxides, organic solvents such as aromatic hydrocarbons such as benzene and toluene, esters such as ethyl acetate and butyl acetate, cyclic ethers such as dioxane and tetrahydrofuran, and methyl ethyl ketone, etc. The solubility in ketones, chloroform, carbon tetrachloride, etc. is greatly improved. This means that when added to a vinyl monomer as a polymerization initiator, it is rapidly dissolved in the monomer, resulting in a significant improvement in workability during industrial use. (3) High efficiency at the start of polymerization. That is, compared to the conventional diacyl type polymeric peroxide, the value of the present invention is about twice as large. (4) Since the diacyl-type polymeric peroxide of the present invention has many peroxide groups in one molecule, it exhibits a unique polymerization reaction that cannot be obtained with ordinary monofunctional peroxides in the polymerization of vinyl-type monomers. can be done. For example, compared to when styrene is polymerized using benzoyl peroxide or lauroyl peroxide, when the diacyl type polymeric peroxide of the present invention is used,
A polystyrene is obtained whose molecular weight is approximately doubled. Vinyl type monomers that can be polymerized with the diacyl type polymeric peroxide of the present invention include, in addition to styrene, for example, vinyl acetate, acrylic acid ester, methyl methacrylic acid ester, acrylonitrile, vinylidene chloride, vinyl chloride, ethylene, etc. be. (5) A so-called block copolymer can also be obtained by polymerizing two types of vinyl monomers using the diacyl polymer peroxide of the present invention. For example, in the first step, styrene is polymerized with this peroxide to introduce one or more peroxide groups into the polystyrene, and in the second step, the peroxide group-containing polystyrene is polymerized with a different vinyl type monomer such as methyl methacrylate. A block copolymer can be obtained by polymerizing the polymers. In particular, when the diacyl type polymer peroxide of the present invention is used for this purpose, blocking efficiency is improved. The reason for this is that, as mentioned above, it has extremely good solubility in vinyl monomers. In the first stage of polymerization, when conventional diacyl polymer peroxide, which has low solubility in vinyl monomers, is used, polymerization starts only on the surface of the partially dissolved or undissolved parts. The proportion of peroxide groups entering the chain is relatively small, and the proportion of unreacted diacyl type polymeric peroxide remaining is large. Therefore, when this mixture is used in the second stage polymerization,
Naturally, a homopolymer of vinyl monomers is produced as a by-product, resulting in a decrease in blocking efficiency. To avoid this, there is a method to purify the peroxide group-containing polymer by separating the unreacted diacyl-type polymer peroxide at the end of the first-stage polymerization, but it is difficult to prepare the separation equipment, and the process is long, making it difficult to manufacture. This is disadvantageous. Further, the remaining unreacted diacyl type polymer peroxide is not effectively utilized, resulting in a corresponding loss. Needless to say, the types of vinyl monomers that can be subjected to block copolymerization using the diacyl polymer peroxide of the present invention are not limited to the above-mentioned examples. Any combination is possible. As described above, the diacyl-type polymeric peroxide of the present invention is safe to manufacture and handle, and when added to a vinyl-type monomer as a polymerization initiator, it dissolves quickly and has excellent efficiency as a polymerization initiator. It has these advantages and its industrial value is extremely high. Next, the present invention will be explained using Examples, Comparative Examples, and Reference Examples. Example 1 After stirring, in a four-necked flask equipped with a thermometer,
% sodium hydroxide aqueous solution 137g (0.24mol) and
Mix with 8.2g (10.12mol) of 50% hydrogen peroxide,
A sodium peroxide aqueous solution was prepared. Next 7,12
-Dimethyloctadecane-1,20 dicarboxylic acid chloride (purity 99%) 41g (0.1 mol) and benzene 40
The solution containing g was added little by little under stirring at a temperature of 0 to 5°C. After stirring at this temperature for 30 minutes, the mixture was neutralized to pH 7 with dilute hydrochloric acid. Next, the oil layer was taken out, washed twice with water, and then dried over anhydrous magnesium sulfate. The solid matter was removed by filtration, and then toluene was distilled off under reduced pressure to obtain 31 g of a clear viscous liquid. The amount of active oxygen in this viscous liquid was determined by the usual iodometry method and was found to be 4.14%. The characteristic absorption wavelengths in the infrared absorption spectrum of this viscous liquid are 1780 cm ^-1 and 1800 cm ^-1 (of diacyl groups).

[Formula] bond), 880cm ^-1 (-O-O- bond) and 1050cm ^-1 (C-O bond), and the δ value and intensity of the nuclear magnetic resonance spectrum are 0.84ppm (6H) 1.28ppm (24H) 1.68ppm (6H) and 2.38ppm (4H), it was confirmed that it was a diacyl type polymeric peroxide represented by the following structural unit. Next, the average molecular weight of this peroxide is
The value was 9870 when measured by the VPO method. Next, the safety level of this peroxide is determined by "safety engineering".
It was determined by the test method described in Vol. 4, No. 2, p. 181 (1965), and the results are shown in Table 1 below. Next, the amount of this peroxide dissolved in various solvents (100 g) at 25°C was measured, and the results are shown in Table 2 below. Example 2 The amount of 50% hydrogen peroxide was 5.5 g (0.08 mol),
7,12-dimethyloctatecane 1,20-dicarboxylic acid with an acid value of 310 manufactured by Okamura Oil Co., Ltd. (trade name: OSK-DA)
Reaction, separation, and purification were carried out in the same manner as in Example 1, except that 41 g of dichloride from IPS22) was used.
27 g of clear viscous liquid was obtained. The active oxygen content of this viscous liquid was determined in the same manner as in Example 1, and was found to be 3.42%. In addition, this product has the same characteristic absorption wavelength of the infrared absorption spectrum and the δ value and intensity of the nuclear magnetic resonance spectrum as those of Example 1, so it is the same as the diacyl type polymer peroxide obtained in Example 1. It was confirmed that it consists of constituent units. The average molecular weight of this peroxide was then measured in the same manner as in Example 1 and found to be 2,320. Example 3 7% sodium hydroxide aqueous solution 137g (0.24mol)
134.7g (0.24mol) of 10% potassium hydroxide aqueous solution
The reaction, separation, and purification were carried out in the same manner as in Example 1 except that 32 g of a transparent viscous liquid was obtained. The active oxygen content of this viscous liquid was determined in the same manner as in Example 1 and was found to be 4.16%. In addition, this product has the same characteristic absorption wavelength of the infrared absorption spectrum and the δ value and intensity of the nuclear magnetic resonance spectrum as those of Example 1, so it is the same as the diacyl type polymer peroxide obtained in Example 1. It was confirmed that it consists of constituent units. The average molecular weight of this peroxide was then measured in the same manner as in Example 1 and found to be 14,700. Comparative Example 1 Adipic acid chloride and sodium peroxide were reacted to produce a known solid diacyl polymer peroxide. This peroxide is determined by the following formula from the characteristic absorption wavelength of the infrared absorption spectrum and the δ value and intensity of the nuclear magnetic resonance spectrum. It was confirmed that it is a peroxide consisting of the following structural units. Furthermore, the average molecular weight was 940 as determined by the VPO method. Next, the safety and solubility of this peroxide were determined in the same manner as in Example 1, and the results are shown in Tables 1 and 2 below. Comparative Example 2 A known solid diacyl polymer peroxide was produced by reacting dodecanedioic acid chloride with sodium peroxide. This peroxide is determined by the following formula from the characteristic absorption wavelength of the infrared absorption spectrum and the δ value and intensity of the nuclear magnetic resonance spectrum. It was confirmed that it is a peroxide consisting of the following structural units. Further, its average molecular weight was 1620 as determined by the VPO method. The safety and solubility of this peroxide were determined by the same method as in Example 1, and the results are shown in Tables 1 and 2.

【table】

[Styrene polymerization (bulk polymerization) and measurement of average molecular weight]

Styrene 1 and diacyl polymer peroxide prepared in Example 1 as a polymerization initiator 0.09
5 ml of the sample prepared by dissolving the moles was sealed in a glass ampoule with an inner diameter of 12 mm, and polymerization was carried out at 70°C for 7 hours. Thereafter, the reaction solution was taken out, dissolved in 50 ml of benzene, and unreacted styrene monomer was quantified by gas chromatography using an internal standard method to determine the polymerization conversion rate. Then, pour it into 500ml of methyl alcohol,
A white precipitate of polystyrene was deposited. After drying this white precipitate, the average molecular weight of the polystyrene was determined by GPC (High Performance Liquid Chromatograph Model HLC-802UR manufactured by Toyo Soda Kogyo). For comparison, ordinary lauroyl peroxide was used instead of diacyl-type polymeric peroxide.
Similar operations were performed to determine the polymerization conversion rate and the average molecular weight of polystyrene. These results are shown in the third
Shown in the table.

[Styrene polymerization (bulk polymerization) and measurement of polymerization initiator efficiency]

5 ml of a sample prepared by dissolving 0.02 mol of diacyl-type polymer peroxide produced in Example 1, Comparative Examples 1 and 2 as a polymerization initiator in each styrene was sealed in a glass ampoule with an inner diameter of 12 mm, and heated at 60°C. Polymerization was carried out, and the initiator ratio was determined for each polymerization initiator. The initiator efficiency was measured based on the method described in "Vinyl Polymerization Experimental Method" (published by Kyoritsu Shuppan Co., Ltd.), page 256. The results obtained are shown in Table 4.

[Table] As is clear from Table 4, the initiator efficiency of the diacyl polymer peroxide of the present invention is approximately twice as high as that of the known diacyl polymer peroxide, indicating that it is excellent as a polymerization initiator. ing. Although the present invention has been described with reference to specific examples, without departing from the broader spirit and scope of the invention,
Of course, various changes and modifications are possible.

Claims (1)

[Claims] First-order general formula A diacyl-type polymeric peroxide consisting of the structural unit represented by the formula and having an average molecular weight of 2,000 to 17,000.