JPH11181021A - Production of carboxyl group-containing macromonomer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject high-purity macromonomer useful as a raw material for coating materials, coating, etc., in a relatively simple step by reacting a specific hydroxyl group-containing macromonomer with a dicarboxylic acid anhydride. SOLUTION: (A) A monomer having hydroxyl group at an arbitrary site and having a radically polymerizable group at one terminal is reacted with (B) a dicarboxylic anhydride in the presence of a catalyst promoting esterification reaction, preferably in an organic solvent at 50-150 deg.C to provide the objective carboxyl group-containing macromonomer. The component A can be obtained by reaction of a polymer having carboxyl group at one terminal with glycidyl (meth)acrylate. Further, a amount (molar number) of the component B used to the component A is not larger than an amount of hydroxyl group in the macromonomer. Preferable introduction amount of the carboxyl group is an average 1-20 per molecule of the macromonomer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a radical polymerizable macromonomer having a carboxyl group in a polymer skeleton. The macromonomer is
A macromonomer that can be used as a raw material for paints, coatings, adhesives or electronic materials, and that is obtained by neutralizing it with a base, is useful as a reactive emulsifier.

[0002]

2. Description of the Related Art Macromonomers are attracting attention as raw materials for producing graft copolymers, and many types of macromonomers are known today. recently,
Macromonomers having a functional group such as a carboxyl group, a hydroxyl group or an amide group in the polymer skeleton have also been developed. In particular, carboxyl group-containing macromonomers have a wide range of uses, and their demand has grown greatly. Some proposals have also been made regarding the production method as described below. That is, in JP-A-1-178512 and JP-A-1-268709, after once synthesizing a macromonomer having an ester structure having a t-butoxy group as an alcohol residue, by decomposing the ester, A method for producing a macromonomer having a carboxyl group has been proposed. On the other hand, JP-A-9-
176256 proposes a method of using a cobalt complex as a chain transfer agent in radical polymerization when producing a polymer skeleton. However, the former method has a problem of treating by-products such as isobutylene generated together with a carboxyl group when the ester is decomposed, and the latter has a problem that industrialization is difficult.

[0003]

Means for Solving the Problems The present inventors have conducted intensive studies to obtain a production method comprising a relatively simple process and a high purity carboxyl group-containing macromonomer. The present invention has been completed. That is, the present invention provides a method for producing a carboxyl group-containing macromonomer, which comprises reacting a macromonomer having a hydroxyl group at an arbitrary site and having a radical polymerizable group at one end with a dicarboxylic anhydride. is there. Hereinafter, the present invention will be described in more detail.

[0004]

DETAILED DESCRIPTION OF THE INVENTION Macromonomers having a radical polymerizable group at one end of a polymer having a hydroxyl group, ie, hydroxyl group-containing macromonomers, which are starting materials for the carboxyl group-containing macromonomer in the present invention, are known in the art. It can be manufactured by the method described above. As an example of the method for producing the hydroxyl group-containing macromonomer, a polymer having a carboxyl group at one end and glycidyl (meth)
There is a method utilizing the reaction of acrylate. To summarize, first, in an organic solvent in the presence of a mercaptan having a carboxyl group such as mercaptoacetic acid, mercaptopropionic acid, mercaptobutyric acid or thiosalicylic acid, a radical polymerizable monomer having a hydroxyl group (hereinafter referred to as a hydroxyl group) A monomer having a hydroxyl group in a chain of repeating units and a carboxyl group at one end (hereinafter referred to as a base polymer) by radical polymerization of another monomer as necessary. To manufacture. Subsequently, a hydroxyl group-containing macromonomer is obtained by reacting a terminal carboxyl group in the obtained base polymer with, for example, glycidyl methacrylate.

The hydroxyl group-containing monomers used in the production of the base polymer include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate and Hydroxyethyl (meth) acrylate with ε
A compound to which caprolactone is added (eg, Placcel, trade name, manufactured by Daicel Chemical Industries, Ltd.), and the like.

Examples of the copolymerizable monomers that can be used together with the above-mentioned hydroxyl group-containing monomer include methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate.
Acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate, trifluoroethyl (meth) acrylate, perfluoroalkylethyl (meth) acrylate, dimethylaminoethyl ( Meth) acrylate, styrene, α-
Examples include methylstyrene and acrylonitrile. In the present invention, the base polymer is preferably a copolymer of a hydroxyl group-containing monomer and the above-mentioned copolymerizable monomer, in view of a wide application range of the obtained macromonomer, more preferably, It is a copolymer having an average of 3 to 30 hydroxyl groups per molecule.

The radical polymerization of the above monomers is carried out in an organic solvent in the presence of a mercaptan having a carboxyl group such as mercaptoacetic acid, mercaptopropionic acid, mercaptobutyric acid or thiosalicylic acid. Mercaptan acts as a chain transfer agent in radical polymerization and binds to one end of the polymer. The preferred amount of the mercaptan used is an amount equimolar to the obtained base polymer, and can be easily calculated from the amount of the monomer used and the required number average molecular weight of the base polymer. The preferred number average molecular weight of the base polymer is from 1,000 to 30,000. When trying to obtain a base polymer having a number average molecular weight of 1,000 to 30,000, the amount of mercaptan used is about 0.1 to 5 g per 100 g of monomer.

[0008] The polymerization temperature is preferably 50 to 140 ° C, and as the polymerization solvent, ethyl acetate, butyl acetate, methyl isobutyl ketone, toluene or xylene can be preferably used. Examples of the polymerization initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, butylperoxypivalate, butylperoxyoctanoate, and the like.
0.1 to 3 parts by weight per 100 parts by weight of the monomer.

The intended hydroxyl group-containing macromonomer is a base polymer having a hydroxyl group in the molecular chain obtained by the above polymerization and having a carboxyl group at one terminal, and a base polymer having a reactivity with a carboxyl group such as an epoxy group. And a compound having both a functional group and a radical polymerizable group, for example, glycidyl methacrylate. The reaction of such macromonomerization is as follows:
The process proceeds smoothly by maintaining the temperature at 70 to 120 ° C. in the presence of a catalyst such as a quaternary ammonium salt or a quaternary phosphonium salt in an organic solvent. As the organic solvent used as the reaction medium, the compounds exemplified as the polymerization solvent for obtaining the base polymer can be used. In addition, there are many known documents regarding the above-mentioned macromonomerization reaction, and the details are referred to.

Next, a carboxyl group-containing macromonomer is obtained by reacting the hydroxyl group-containing macromonomer obtained by the above method with a dicarboxylic anhydride. This reaction is carried out in an organic solvent at a reaction temperature of 50 to 150 ° C. in the presence of a catalyst for promoting the esterification reaction.
It is preferable to carry out in. The reaction time may be usually about several hours, and as the organic solvent, the same compound as the polymerization solvent for obtaining the base polymer or the organic solvent for the macromonomerization reaction can be used. As dicarboxylic anhydrides, succinic anhydride, phthalic anhydride, citraconic anhydride,
Examples include methyl succinic anhydride and acetyl malic anhydride, and succinic anhydride is preferred.

The amount (molar number) of the dicarboxylic anhydride used relative to the hydroxyl group-containing macromonomer may be at most the amount of the hydroxyl group in the macromonomer. If the amount of the dicarboxylic anhydride used is equivalent to the hydroxyl group in the hydroxyl group-containing macromonomer, a macromonomer having only a carboxyl group as a functional group is obtained, while the hydroxyl group in the hydroxyl group-containing macromonomer is If less, a macromonomer having hydroxyl and carboxyl groups as functional groups is obtained. The preferred amount of the carboxyl group to be introduced is an average of 1 to 20 per macromonomer molecule.

As the catalyst, sulfuric acid, paratoluenesulfonic acid, sulfonic acid type ion exchange resin, tertiary amine such as triethylamine or tributylamine, quaternary ammonium salt such as tetraalkylammonium bromide or triethylbenzylammonium chloride, and tetraalkyl Phosphonium bromide and the like. Preferred catalysts are tertiary amines or quaternary ammonium salts in that the resulting reaction product solution is less likely to be colored.

By the above operation, the desired carboxyl group-containing macromonomer is obtained. The carboxyl group-containing macromonomer of the present invention includes alkyl (meth) acrylate, perfluoroalkyl (meth) acrylate, acrylonitrile, vinyl acetate, vinyl propionate, styrene, α-methylstyrene, (meth) acrylamide,
Hydroxyalkyl (meth) acrylate or (meth) acrylate
It is used for copolymerization with acrylic acid or the like, and the resulting graft copolymer is used for paints, adhesives or dispersants. Further, the carboxyl group-containing macromonomer or the graft copolymer obtained therefrom can be optionally hydrophilicized by neutralizing the carboxyl group contained therein with a base such as ammonia or an amine. Since the macromonomer or the graft copolymer obtained by neutralizing the carboxyl group is dissolved or emulsified and dispersed in an aqueous medium, an aqueous medium can be used instead of an organic solvent. Hereinafter, the present description will be described more specifically with reference to examples and comparative examples. In each example, “parts” means “parts by weight”.

[0014]

[Production Example 1] (Production of hydroxyl group-containing macromonomer) 70 parts of butyl methacrylate and 30 parts of hydroxyethyl methacrylate were added dropwise to 105 parts of butyl acetate at a polymerization temperature of 90 ° C under a nitrogen stream while adding azobisisomethacrylate. Radical chain transfer polymerization was carried out using butyronitrile (hereinafter abbreviated as AIBN) and 2.0 parts of 3-mercaptopropionic acid. The butyl methacrylate, hydroxyethyl methacrylate and butyl acetate used were those that had been dehydrated with molecular sieve before use.
1 part of tetrabutylammonium bromide (catalyst), 0.1 part of hydroquinone monomethyl ether (polymerization inhibitor) and 2.7 parts of glycidyl methacrylate were added to the obtained one-terminal carboxyl group type polymer solution, and the mixture was added at 90 ° C. for 6 hours.
By reacting for a time, a radical polymerizable double bond was introduced at the terminal. The obtained hydroxyl group-containing macromonomer had a number average molecular weight (in terms of polystyrene by GPC measurement) of 5,400 and a hydroxyl value of 137.
mg KOH / g (per solid). This corresponds to an average of 13.2 hydroxyl groups per molecule.

[0015]

Example 1 (Production of carboxyl group-containing macromonomer A) Hydroxyl group-containing macromonomer solution obtained in Production Example 1 (solid content: 50% by weight) was placed in a flask equipped with a stirrer, a condenser and a thermometer. 200 parts, 20 parts of succinic anhydride and 80 parts of butyl acetate dehydrated by molecular sieve were added, and heated at 90 ° C. for 6 hours. As the catalyst, tetrabutylammonium bromide added during production of the hydroxyl group-containing macromonomer was used as it was. At the beginning of the reaction, fine succinic anhydride powder was found to be floating in the reaction solution, but as the reaction proceeded, insolubles disappeared in the solution. The acid value (per solution) at 4, 5 and 6 hours after starting the heating is 0.65 meq / g,
0.68 meq / g and 0.68 meq / g, indicating the end of the reaction. The number average molecular weight of the obtained macromonomer A was 6,400, and the number of carboxyl groups per macromonomer molecule was 10.4 on average. This macromonomer contains an average of 2.8 hydroxyl groups per macromonomer molecule.

[0016]

Example 2 (Production of carboxyl group-containing macromonomer B) Carboxyl group-containing macromonomer B was produced in the same manner as in Example 1, except that the amount of succinic anhydride used was changed to 10 parts. The number average molecular weight of the obtained macromonomer B was 6000, and the number of carboxyl groups per macromonomer molecule was 5.4 on average. This macromonomer contains an average of 7.8 hydroxyl groups per macromonomer molecule.

[0017]

[Application Example 1] (Production of graft copolymer A) A butyl acetate solution of the carboxyl group-containing macromonomer obtained in Example 2 was placed in a flask equipped with a stirrer, a condenser, a dropping funnel, a thermometer and a nitrogen inlet tube. (Solid concentration: 40
50% by weight) and 70 parts of butyl acetate were charged, and the gas phase was replaced with nitrogen gas.
Raised to 0 ° C. Next, 40 parts of butyl methacrylate,
Styrene 20 parts, hydroxyethyl methacrylate 20
Of azobis (2-methylbutyronitrile) was dropped into the flask from the dropping funnel over 4 hours. After the completion of the dropping, heating was continued for 2 hours to obtain a graft copolymer solution (solid content: 50% by weight). The number average molecular weight of the obtained graft copolymer was 12,000, and the acid value was 0.19 meq / g (per solid).

[0018]

Application Example 2 (Production of water-dispersible macromonomer) 100 parts of a butyl acetate solution (solid content: 40% by weight) of the carboxyl group-containing macromonomer obtained in Example 1 was added to 2 parts.
3.5 parts of 0% ammonia water and 20 parts of distilled water were added, and the mixture was stirred at room temperature for 30 minutes to obtain a uniform solution. Thereafter, 70 parts of distilled water was further added, and butyl acetate was distilled off under reduced pressure to obtain a macromonomer aqueous liquid having a solid content of 35% by weight. The aqueous liquid was slightly milky white, but did not precipitate even after standing for one week. (Production of water-dispersible graft copolymer) In a flask equipped with a stirrer, a condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube, 100 parts of the above macromonomer aqueous liquid, 35 parts of distilled water, and 0.5 part of ammonium persulfate. Then, 0.7 parts of ammonium carbonate were charged, and the gas phase was replaced with nitrogen gas. Then, the temperature of the content liquid was raised to 80 ° C. Next, a mixed solution of 60 parts of butyl methacrylate and 5 parts of styrene was dropped into the flask from the dropping funnel over 2 hours. After the completion of the dropping, heating was continued for 1 hour, whereby an aqueous dispersion of the graft copolymer (solid content: 50%) was obtained.
% By weight, polymer particle size: 0.1 μm).

[0019]

According to the present invention, a carboxyl group-containing radically polymerizable macromonomer can be produced by an industrially advantageous method as compared with the conventional method, and the macromonomer is a graft copolymer having a carboxyl group in a branch. Useful as a raw material for coalescence. Further, such a graft copolymer is a coating,
It can be preferably used as a coating, an adhesive, a pressure-sensitive adhesive and an electronic material.

Claims (1)

[Claims] 1. A macromonomer having a hydroxyl group at an arbitrary site and having a radical polymerizable group at one end,
A method for producing a carboxyl group-containing macromonomer, comprising reacting a dicarboxylic anhydride.