JPH0625208B2 - Polymerization initiator - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polymerization initiator containing a specific carboxylic acid group-containing unsaturated peroxy ester as an active ingredient, and particularly useful for the polymerization of unsaturated vinyl monomers. It relates to a polymerization initiator.

(Prior Art) In recent years, functional polymers having highly reactive functional groups in the main chain or side chain of the polymer have been attracting attention because of their interesting physical properties and various high reactivity. It was It is known to use a carboxylic acid group-containing peroxy ester as a polymerization initiator for the synthesis of a functional polymer. Peroxyester containing a carboxylic acid group as a functional group, when used as a polymerization initiator of an unsaturated vinyl monomer, can impart a carboxylic acid group to the polymer terminal, which is useful for synthesizing functional polymers, particularly macromonomers. It is a useful and therefore interesting organic peroxide in the future.

As such an organic peroxide, conventionally, succinic anhydride or maleic anhydride and a tertiary hydroperoxide such as t-butyl hydroperoxide or t-amyl hydroperoxide are present in the presence of an organic base such as pyridine. A peroxy ester having a carboxylic acid group which is synthesized by reacting is known. For example, JP-A-50-126613 discloses maleic anhydride or succinic anhydride and t-butyl hydroperoxide (t-BuOO).
H) or t-amyl hydroperoxide (t-AmOO
It has been reported that by reacting H) with pyridine in the presence of pyridine, a peroxy ester containing a carboxylic acid group can be obtained as shown in the following formula.

(Problems to be Solved by the Invention) However, this kind of carboxylic acid group-containing peroxy ester is hardly soluble in an organic solvent, explosive, and is solid, and thus it is inconvenient to handle. For example, mono-t-butylperoxymaleate shows almost no solubility in ordinary organic solvents such as toluene, benzene, and xylene, and therefore cannot be used in bulk polymerization, solution polymerization or suspension polymerization. There was a problem. Furthermore, these peroxyesters are solid, have high friction sensitivity, and are explosive peroxides, and are therefore difficult to handle.

In order to solve such a problem, it was necessary to develop a carboxylic acid group-containing peroxy ester which is easily soluble in an organic solvent and has high safety.

(Means for Solving Problems) The present invention provides a carboxylic acid group-containing peroxy ester having a high general formula: (In the formula, R represents an alkenyl group having 6 to 18 carbon atoms and R'represents a methyl, ethyl or propyl group.) Is used as an active ingredient of the polymerization initiator. In the above formula, R is an alkenyl group having 6 to 18 carbon atoms. When the number of carbon atoms is less than 6, the solubility in organic solvents is low and therefore the risk of explosiveness and the like increases, which is not preferable, and when the number of carbon atoms exceeds 18, the viscosity becomes high, which is disadvantageous in terms of production. R'in the formula represents a methyl, ethyl or propyl group. A carbon number of 4 or more is disadvantageous in terms of raw material. That is, it is because t-hydroperoxide as a raw material having such a carbon number is not readily available at present. The polymerization initiator containing this compound can perform bulk polymerization, solution polymerization, suspension polymerization or emulsion polymerization of unsaturated vinyl monomers, and a polymer having a carboxylic acid group can be easily obtained.

The unsaturated peroxyester containing a carboxylic acid group used in the present invention is obtained as a simple substance or a mixture, and is, for example, t
-Butylperoxy-β-carboxy-nonadecenoate (in the formula (I), However, R ¹ + R ² = C ₁₃ H ₂₈ , and R ¹ + R ² is a mixture of alkyl groups having 13 carbon atoms. The same applies hereinafter], t-butylperoxy-β-carboxy-pentadecenoate [ , Provided that R ¹ + R ² = C ₉ H ₂₀ ] t-butylperoxy-β-carboxy-undecenoate [R = -CHR'CH _2- , provided that R '=-CH ₂ -C = C
H-C _{(CH 3)} 3 and t-butylperoxy-2-carboxy-4-methyl-
4-Cyclohexene-1-carboxylate and its isomer t-butylperoxy-2-carboxy-
5-methyl-4-cyclohexene-1-carboxylate t-Butylperoxy-β-carboxy-heptenoate t-amyl peroxy-β-carboxy-nonadecenoate However, R < ¹ > + R < ² > = C < ₁₃ > H < ₂₈ >], t-amyl peroxy- (beta) -carboxy- pentadecenoate. Provided that R ¹ + R ² = C ₉ H ₂₀ ], t-amylperoxy-β-carboxy-undecenoate [R = -CHR′CH ₂ —, provided that and t-amyl peroxy-2-carboxy-4-methyl-
4-Cyclohexene-1-carboxylate and its isomer t-amylperoxy-2-carboxy-
5-methyl-4-cyclohexene-1-carboxylate t-amyl peroxy-β-carboxy-heptanoate t-hexyperoxy-β-carboxy-nonadecenoate Provided that R ¹ + R ² = C ₁₃ H ₂₈ ], t-hexylperoxy-β-carboxy-pentadecenoate. Provided that R ¹ + R ² = C ₉ H ₂₀ ], t-hexylperoxy-β-carboxy-undecenoate [R = -CHR′CH ₂ —, provided that and t-Hexylperoxy-2-carboxy-4-methyl-4-cyclohexene-1-carboxylate and its isomer t-hexylperoxy-2-carboxy-5-methyl-4-cyclohexene-1-carboxylate t-hexylperoxy-β-carboxy-heptenoate Etc.

These carboxylic acid group-containing unsaturated peroxyesters can be produced by reacting a specific alkenyl succinic anhydride and t-hydroperoxide in the presence of a basic substance such as pyridine as a catalyst. The raw material alkenyl succinic anhydride may be a mixture of isomers. For example, as dodecenyl succinic anhydride, trade name "DSA" manufactured by Sanyo Kasei Co., Ltd. ) Product name “HDSA” and the like can be used.

The product produced by the above method is liquid, IR and
It can be identified by NMR, and has a half-life temperature of 85 to 110 as selected for 10 hours by thermal decomposition in an aromatic solvent.
Indicates the range of ° C.

When the unsaturated peroxyester containing a carboxylic acid group thus obtained is used as a polymerization catalyst for unsaturated vinyl monomers, it can be used alone, and further, an aromatic solvent such as toluene, benzene and xylene. Alternatively, it can be used in the same manner by diluting it with an aliphatic solvent such as pentane, octane and cyerzole.

A polymerization initiator containing a carboxylic acid group-containing peroxy ester as an active ingredient, and the polymerizable unsaturated vinyl monomer is, for example, styrene, methyl acrylate, methyl methacrylate, ethylene, vinyl chloride, vinyl acetate, etc. .

(Effect of the Invention) The polymerization initiator of the present invention has the following effects.

(1) The polymerization initiator of the present invention is useful for the polymerization of unsaturated vinyl monomers. In the obtained polymer, a carboxylic acid group which is a functional group is substituted at the polymer terminal. Therefore, the carboxylic acid can be reacted with another highly reactive substrate to obtain a more functional polymer.

(2) The carboxylic acid group-containing unsaturated peroxy ester represented by the general formula (I), which is an active ingredient, is a liquid and has a low friction sensitivity, and is safer than conventional mono-t-butylperoxymaleate and the like. It is a peroxide that is high and easy to handle.

(3) Further, this peroxy ester has high solubility in common organic solvents such as toluene, benzene, and hexane. Therefore, it can be easily used as a polymerization initiator for bulk polymerization, solution polymerization, suspension polymerization and the like.

(4) Further, this peroxyester can be applied similarly to other organic peroxides, and is also effective as an unsaturated polyester resin curing agent.

(Example) Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

Example 1 Preparation of t-butylperoxy-β-carboxyundecenoate Pentane containing 36.50 g of t-butyl hydroperoxide 66.
In a solution of 28 g, 72.54 g of octenyl succinic anhydride,
Add at room temperature, then add 380 g of pentane and stir. 80 g of a solution of pentane containing 10.70 g of pyridine
Was added dropwise at 8 to 10 ° C over 3 minutes, and then aged at 20 ° C for 1 hour. After aging, add 1 to the resulting solution.
After washing with 0% HCl, it was washed with an aqueous solution containing sodium sulfite, acetic acid and sodium acetate. Then, it was washed with water, dried using magnesium sulfate, and pentane was removed under reduced pressure to obtain 96.82 g of a colorless liquid. As a result of identifying this liquid by IR (confirming carbonyl absorption at 1710 cm ^-1 and 1775 cm ^-1 ) and NMR (see Table 1), it was confirmed that it was the target t-butylperoxy-β-carboxy-undecenoate. did.

The purity was 91.63% (yield 85.60%).

When the 10-hour selection half-life temperature of this peroxyester was determined by a usual method in toluene, it was 9
It was 8 ° C.

Next, the solubility (compatibility) of this peroxyester in toluene, benzene, xylene, and sielzole at room temperature was examined. The results are shown in Table 2,
Both have excellent solubility in aromatic solvents.

Further, when a ballistic mortar test was conducted on this peroxyester by a method according to JIS-K4810, it was 1.00% (vs. trinitrotoluene) as shown in Table 1.

Solution Polymerization of Styrene Next, using this peroxyester, solution polymerization of styrene was carried out by the following method.

That is, 9.85 g of t-butylperoxy-β-carboxy-undecenoate and 10.42 g of styrene were dissolved in benzene and the whole was adjusted to 50 ml. After the adjustment, polymerization was carried out at 80 ° C. for 4 hours under a nitrogen stream. After completion of the polymerization, the polymer was placed in methanol to precipitate the polymer, and then purification with benzene and methanol was repeated 3 times. Number average molecular weight of the obtained polymer by GPC, M
_N = 7720, Atsuta a weight average molecular weight _{M W} = 12300. Also
It was confirmed by IR that carboxylic acid groups were contained in the polymer since carbonyl absorption was observed at 1710 cm ^-1 and 1775 cm ^-1 .

Bulk Polymerization of Styrene Bulk polymerization of styrene was carried out by the following method using t-butylperoxy-β-carboxyundecenoate obtained by the above preparation method.

That is, the peroxy ester was added to 300 ml of styrene.
Add 2.95g, 70 in nitrogen atmosphere in pressure ampoule tube.
Polymerization was performed at 6 ° C. for 6 hours, at 75 ° C. for 4 hours, and at 80 ° C. for 4 hours.

After the polymerization, the obtained polymer is put in methanol to precipitate the polymer, and the polymer is purified with benzene and methanol to 3 times.
Repeated times. The average molecular weight of the obtained polymer by GPC is shown in the following table.

Curing of Unsaturated Polyester Resin Using t-butylperoxy-β-carboxy-undecenoate obtained by the above preparation method, the unsaturated polyester resin was cured by the following method.

That is, 1.0 g by weight of t-butylperoxy-β-carboxy-undecenoate as a curing agent was added to 25 g of EPORAC G-110AL, which is an unsaturated polyester resin manufactured by Nippon Shokubai Kagaku Co., as a curing agent, and
The polyester resin was cured in a constant temperature bath at 0.0 ° C.

As a result, the unsaturated polyester resin reached the maximum exothermic temperature of 220 ° C. after 11 minutes, and it was confirmed that the resin was cured. The method for curing the resin was according to JIS-K6901. The surface hardness of the obtained cured product was measured by a Barcol hardness tester (GYZJ934
It was 45-46 when it measured by 1 type.

Examples 2 to 5 Preparation of peroxyesters Octenyl succinic anhydride was converted into hexadecenyl succinic anhydride (manufactured by Nissan Chemical Industries, trade name "HDSA"), dodecenyl succinic anhydride (manufactured by Sanyo Kasei Co., trade name "DSA") or 4
-Methyl-1,2,3,6-tetrahydrophthalic anhydride was replaced with t-butyl hydroperoxide in place of t-hexyl hydroperoxide, and a procedure similar to that of Example 1 was followed. .

The obtained product was identified by IR and NMR (see Table 1) in the same manner as in Example 1 and confirmed to be the target peroxyesters.

Then, in the same manner as in Example 1, the 10-hour selection half-life temperature of each was determined, the solubility in a solvent was examined, and a ballistic mortar test was conducted. The results are shown in Table 1.

Solution Polymerization of Styrene Next, solution polymerization of styrene was carried out by the method shown in Example 1 using each of the peroxyesters. The number average molecular weight of each of the obtained polymers was determined by the same method as in Example 1. The results are shown in Table 1. It was also confirmed by IR analysis of each polymer that the polymer contains a carboxylic acid group.

Comparative Example 1 Preparation of Peroxy Ester Toluene Solution Containing t-Butyl Hydroperoxide 24.7
Maleic anhydride (9.8 g) was added to 1 g, and then pyridine was added.
1 g was added dropwise at 10 ° C. After completion of dropping, 1 at 25 ℃
Time was matured. After aging, the obtained crystals were filtered, washed with 10% methanol water, and dried to obtain 16.2 g of the target mono-t-butylperoxymaleate with a white yield of 16.2 g and 83.5%. Obtained as a crystalline substance.

For this peroxyester, the 10-hour selection half-life temperature was determined in ethyl acetate by the usual method,
The temperature was 96 ° C.

Then, the solubility of this peroxyester in a solvent was examined by the same method as in Example 1, but it was almost insoluble in the aromatic system and chelsol.

Next, this peroxyester was subjected to the same ballistic mortar test as in Example 1. The result was 19.6% (vs. trinitrotoluene).

Solution Polymerization of Styrene Next, a solution polymerization of styrene was attempted by the method shown in Example 1 using this peroxy ester, but the operation was stopped because it did not dissolve in benzene at all.

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display area C08F 14/06 20/18

Claims (1)

[Claims] 1. A general formula: (In the formula, R represents an alkenyl group having 6 to 18 carbon atoms, and R'represents a methyl, ethyl or propyl group.) A polymerization initiator containing a carboxylic acid group-containing unsaturated peroxy ester represented by the following formula.