JPS6348881B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a novel industrially useful reactive polymer. Specifically, the present invention relates to a method of producing a reactive polymer by reacting a copolymer having an aziridine group with an unsaturated monobasic acid.

"Reactive polymer" as used herein
The term refers to a polymer having a reactive group that "can undergo or participate in a so-called radical reaction" under the action of heat, ultraviolet light, electron beams, free radical generating agents, etc.

Heretofore, several proposals have been made as methods for producing such reactive polymers. One of these uses the so-called esterification reaction, for example, the reaction of a polymer containing free carboxylic acid groups with an unsaturated hydroxyl compound or an unsaturated glycidyl compound, or the reaction of a polymer containing free carboxylic acid groups with an unsaturated hydroxyl or glycidyl compound, or A method is known that utilizes the reaction between carbon dioxide and an unsaturated carboxylic acid compound. However, in the esterification reaction, the reactants are generally kept under harsh temperature conditions for a relatively long period of time, so side reactions such as polymerization of unsaturated groups are likely to occur during the reaction. As a means to reduce such risks, measures such as adding a large amount of polymerization inhibitor to the reaction system, introducing oxygen, and relaxing reaction conditions by using an esterification reaction catalyst are known, but the resulting reaction Polymers often contain excessive amounts of polymerization inhibitors, catalyst residues, etc., which can cause coloration and reaction delays depending on the intended use, resulting in poor quality evaluations.

Another known method utilizes a urethanization reaction, such as a method in which a polymer having a hydroxyl group and an unsaturated hydroxyl compound are bonded via a diisocyanate compound.
However, in this case as well, in addition to the use of a catalyst, typically an organotin compound, to promote the reaction, the hydroxyl groups of the polymer and the hydroxyl groups of the unsaturated compound, and the isocyanate groups of one of the diisocyanate compounds and the isocyanate group of the other It is difficult to selectively react each of the groups, and in order to increase the selectivity of the reaction, a plurality of reaction steps must be performed sequentially, which has the disadvantage of complicating production. As yet another method, the general formula (However, in the formula, R ₁ is hydrogen or a methyl group,
R ₂ to _{R 5} are selected from the group consisting of hydrogen and an alkyl group having 1 to 4 carbon atoms, and may be the same or different. ) A method has been proposed in which a copolymer obtained by copolymerizing an unsaturated aziridine compound represented by the following formula is reacted with an α,β-ethylenically unsaturated monobasic acid to obtain a reactive polymer. Although this method solves the above-mentioned drawbacks, an amino bond derived from an aziridine group is introduced into the side chain of the copolymer. This amino bond is easily affected by heat, chemicals, etc., and in order to form a salt with the unsaturated acid in the reaction system, it requires more α,β-ethylenically unsaturated monobasic acid than the aziridinyl group. , it is uneconomical.

As a result of intensive research to solve the drawbacks of such conventionally known methods, the present inventors found that the aziridine group in a specific copolymer having an aziridine group and the α,β-ethylenically unsaturated monobasic acid The present invention was completed by discovering that a reactive polymer having an amide bond with excellent heat resistance and chemical resistance can be obtained by reacting with a carboxyl group in a specific ratio.

It is therefore an object of the present invention to provide a reactive polymer having a reactive group "capable of causing or participating in a radical reaction" and a method for producing the same.

That is, the present invention provides an unsaturated aziridine compound (A) represented by the following general formula (1) and α, which is copolymerizable therewith.
A copolymer (C) obtained by polymerizing β-ethylenically unsaturated monomer (B) and having aziridine groups in the range of 0.01 to 3 milliequivalents/g, and α,β-ethylene α,β-ethylenically unsaturated monobasic acid (D) in a ratio of 0.2 to 2.0 mol per 1.0 mol of aziridine group possessed by the polymer (C). The present invention relates to a method for producing a reactive polymer characterized by reacting it.

(Note) General formula (1) (However, in the formula, R ₁ is hydrogen or a methyl group,
R ₂ to _{R 6} are selected from the group consisting of hydrogen and an alkyl group having 1 to 4 carbon atoms, and may be the same or different. ) The unsaturated aziridine compound (A) represented by the general formula (1) used in carrying out the present invention includes N
-Acryloylaziridine, N-acryloyl-
2-methylaziridine, N-acryloyl-2,
2-dimethylaziridine, N-acryloyl-2
- Ethylaziridine, N-methacryloylaziridine, N-methacryloyl-2-methylaziridine, N-methacryloyl-2,2-dimethylaziridine, N-methacryloyl-2-ethylaziridine, etc., and one or more of these can be used effectively. Among these, preferred are N-acryloylaziridine and N-methacryloylaziridine.

In the present invention, unsaturated aziridine compound (A)
The copolymer (C) obtained by polymerizing this and the copolymerizable α,β-ethylenically unsaturated monomer (B) is
It must have aziridine groups in the range of 0.01 to 3 meq/g. When the aziridine group content is less than 0.01 milliequivalent/g, a reactive polymer that is considered to be substantially reactive cannot be obtained. Also, when having more than 3 meq/g of aziridine groups, such copolymers are sometimes degraded during storage or during reaction with α,β-ethylenically unsaturated monobasic acids (D). , there is a risk of gelation, which is undesirable.

α copolymerizable with unsaturated aziridine compound (A),
As the β-ethylenically unsaturated monomer (B), methyl ester, ethyl ester, propyl ester of unsaturated monobasic acids such as acrylic acid and methacrylic acid,
Butyl ester, 2-ethylhexyl ester,
Esters such as hydroxyethyl ester, hydroxypropyl ester, and benzyl ester: acrylamide, methacrylamide, and their N
-Substituted products; acrylonitrile, vinyl chloride, vinylidene chloride, vinyl acetate, styrene, ethylene,
Examples include unsaturated monomers such as butadiene, and one or more of these monomers can be effectively used.

A copolymer (C) consisting of an unsaturated aziridine compound (A) and an α,β-ethylenically unsaturated monomer (B) that can be copolymerized with the unsaturated aziridine compound (A) can be produced using a conventionally known method. can. For example, in the presence of peroxides such as benzoyl peroxide and lauroyl peroxide, azo free radical correcting agents such as azobisisobutyronitrile, or under irradiation with active energy rays such as heat and light, solution polymerization or bulk formation is performed. Obtained by polymerization. At this time, a molecular weight regulator such as lauryl mercaptan may also be used if necessary.

The α,β-ethylenically unsaturated monobasic acid (D) used in carrying out the present invention is reacted at a ratio of 0.2 to 2.0 moles per 1.0 mole of aziridine group possessed by the copolymer (C). . α,β-ethylenically unsaturated monobasic acid (D) has aziridine group of copolymer (C) 1.0
If the amount is less than 0.2 mol, the resulting polymer will have a low concentration of reactive unsaturated groups and will hardly be a substantially effective reactive polymer. Also, α,
If the amount of β-ethylenically unsaturated monobasic acid (D) is more than 2.0 mol per 1.0 mol of aziridine groups in the copolymer (C), gelation may occur during production or storage of the reactive polymer. It is dangerous, and when the resulting polymer is made into a cured product, it has poor flexibility and becomes hard and brittle. As α,β-ethylenically unsaturated monobasic acid (D), acrylic acid;
Methacrylic acid; Crotonic acid; Monoalkyl ester of itaconic acid, half-esterified product of maleic anhydride; Dibasic acids such as phthalic anhydride and succinic anhydride and 2-hydroxyethyl acrylate (or methacrylate), 2-hydroxypropyl acrylate ( or methacrylate).

In the method of the present invention, copolymer (C) and α,β-
The reaction with ethylenically unsaturated monobasic acid (D) is carried out at room temperature,
That is, it progresses even at temperatures as low as 20°C. However, if economic efficiency such as shortening of production time is considered, it is preferable to carry out the reaction at a temperature of 50° C. or higher. The upper limit temperature of the reaction cannot be determined depending on the type and amount of the copolymer (C) polymerization inhibitor used, the oxygen concentration of the reaction atmosphere, etc., but it depends on the stability of the α,β-ethylenically unsaturated monobasic acid (D). The temperature is 150°C, taking into consideration the stability and coloring of the resulting reactive polymer. A more preferred temperature range is 50°C to 130°C.

Incidentally, the reaction between the copolymer (C) and the α,β-ethylenically unsaturated monobasic acid (D) may be carried out successively after producing the copolymer (C), or the reaction between the Coalescence (C) may be performed again after storage.

Furthermore, in order to carry out the present invention more safely and obtain a reactive polymer, oxygen may be introduced into the reaction system, and hydroquinone may be added before or after the reaction to ensure long-term stability of the reactive polymer. It is also a preferred embodiment to add known polymerization inhibitors such as , methoquinone, and phenothiazine.

Furthermore, when reacting the copolymer (C) with the α,β-ethylenically unsaturated monobasic acid (D), the copolymer (C) has poor fluidity, making it difficult to react under stirring. In order to facilitate the addition of α,β-ethylenically unsaturated monobasic acid (D) to the reaction system,
It is also a preferred embodiment to use a diluent as appropriate. The diluent is one that can dissolve or decompose both the copolymer (C) and the α,β-ethylenically unsaturated monobasic acid (D), and is capable of dissolving or decomposing both the copolymer (C) and the α,β-ethylenically unsaturated monobasic acid (D). It is appropriately selected from compounds that do not substantially react with the saturated monobasic acid (D). Examples of such compounds include aromatic compounds such as benzene, toluene, xylene, and chlorobenzene, chloroform, carbon tetrachloride, dioxane, methyl ethyl ketone, acetone, ethyl acetate, cellosolves, carbitols, and alcohols. When the obtained reactive polymer is used in combination with a polymerizable monomer, styrene, which is a polymerizable monomer,
Acrylonitrile, vinyl acetate, acrylic esters, methacrylic esters, etc. can be used as reactive diluents.

In this way, the reactive polymer obtained by carrying out the method of the present invention has an amide bond that has high resistance to heat, chemicals, etc., and a highly reactive unsaturated group. In addition, it is used as a chain lengthening agent, blocking agent, grafting agent, crosslinking agent, etc. useful in various fields such as adhesives, coatings, fillers, and molding materials, and exhibits excellent performance.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

Note that "parts" used in the examples mean parts by weight.

Example 1 100 parts of butyl acrylate was placed in a reactor equipped with a stirrer, a thermometer, a condenser, a dropping funnel, and a nitrogen introduction tube.
5 parts of N-methacryloylaziridine, 0.3 parts of azobisisobutyronitrile and butyl mercaptan
A mixture consisting of 2.0 parts was charged, stirred under a nitrogen atmosphere and reacted at 70 to 75°C for 6 hours, then nitrogen introduction was stopped and 3.3 parts of methacrylic acid was continuously added dropwise over 1 hour while maintaining the temperature at 70°C. After that, stirring was continued for an additional 3 hours and cooled to obtain a reaction product. As a result of measuring the concentration of free carboxylic acid groups by titration, this reaction product was a liquid butyl acrylate copolymer in which 80.2% of the aziridine groups in the raw material were converted to unsaturated groups.

Example 2 15 parts of acrylonitrile was added to a reactor equipped with a stirrer, a thermometer, a condenser, a dropping funnel, and a nitrogen introduction tube.
A mixture of 81.9 parts of butyl acrylate, 3.1 parts of N-methacryloyl aziridine, 233.3 parts of ethyl acetate and 0.2 parts of azobisisobutyronitrile was charged,
Stir under nitrogen atmosphere and react at 65°C for 6 hours.
Furthermore, 0.1 part of azobisisobutyronitrile was added and kept at 65°C for 2 hours to complete the copolymerization reaction.
A 30% by weight ethyl acetate solution of a rubbery copolymer containing 0.28 meq/g of aziridine groups was obtained.

Next, 100 parts of this solution was charged into a reactor equipped with a stirrer, a thermometer, and a condenser, and 0.72 parts of methacrylic acid was continuously added dropwise at 80°C with stirring over 1 hour, and the reaction was further maintained at the same temperature for 3 hours. After cooling and drying the contents under reduced pressure, a reaction product was obtained. As a result of quantitative analysis of unsaturated groups in this reaction product, 98% of the aziridine groups in the rubbery copolymer were converted to unsaturated groups.

Claims (1)

[Claims] 1. A compound obtained by polymerizing an unsaturated aziridine compound (A) represented by the following general formula (1) and an α,β-ethylenically unsaturated monomer (B) copolymerizable therewith. A copolymer (C) having aziridine groups in the range of 0.01 to 3 milliequivalents/g and an α,β-ethylenically unsaturated monobasic acid (D) are added to the polymer (C). 1. A method for producing a reactive polymer, which comprises reacting α,β-ethylenically unsaturated monobasic acid (D) at a ratio of 0.2 to 2.0 mol per 1.0 mol of aziridine groups. (Note) General formula (1) (However, in the formula, R ₁ is hydrogen or a methyl group,
R ₂ to _{R 5} are selected from the group consisting of hydrogen and an alkyl group having 1 to 4 carbon atoms, and may be the same or different. )