JPH05295015A - Production of macromonomer - Google Patents

Abstract

PURPOSE:To provide a method of producing a macromonomer whose coloration problem is solved requiring no need of specific treatment. CONSTITUTION:In the presence of a mercaptan of the general formula: HOOC-(CH2)n-SH (n is an integer of 3 to 12), radical polymerization of radically polymerizable monomers is effected to prepare a prepolymer having carboxyl groups on its chain terminals. The prepolymer and a radically polymerizable monomer bearing a glycidyl group is allowed to react in the presence of a catalyst to give the objective macromonomer.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a macromonomer. INDUSTRIAL APPLICABILITY The present invention can be used, for example, as a method for producing a macromonomer useful for a coating material, a coating agent, a resin molding material, and the like, in which functionalization of a polymer material, particularly coloring is a problem.

[0002]

2. Description of the Related Art A high molecular weight monomer having a radical polymerizable group at one end of the molecule is generally called a macromonomer and is excellent in the following points. That is, the graft copolymer obtained by copolymerizing a macromonomer with another radically polymerizable monomer has a feature that the graft efficiency is extremely high because it contains almost no ungrafted polymer. ..

However, during the production of this macromonomer, it is usually accompanied by reddish brown coloration during the reaction. If the colored macromonomer is used as it is to form various materials, its commercial value is reduced. Therefore, conventionally, a step of decolorizing the reaction solution, such as an adsorption treatment with activated carbon, a treatment with an oxidizing agent or a reducing agent, and a precipitation purification method with a poor solvent such as methanol or n-hexane, has been required. However, even with these means, decolorization is still insufficient, and much labor is required. Therefore, it is difficult to say that this is an efficient method for industrial production.

A general method for producing a macromonomer known in the prior art is disclosed in JP-B-43-11224 and JP-A-60-133007, in which mercaptoacetic acid or mercaptoacetic acid used as a chain transfer agent is used. It is a method of reacting a prepolymer obtained by polymerizing a radical polymerizable monomer in the presence of propionic acid, and glycidyl methacrylate in an organic solvent in the presence of a dimethyllaurylamine catalyst. The macromonomer solution obtained in (1) had a reddish brown to yellowish tinge, and coloring occurred at the stage of the reaction between the prepolymer and glycidyl methacrylate.

[0005]

DISCLOSURE OF THE INVENTION The present inventors have solved the coloring of macromonomer, which is still insufficient by the conventional method,
In addition, various studies were conducted with the object of providing a method for producing a macromonomer that does not require special treatment for preventing coloration.

[0006]

As a result of intensive studies to solve the above problems, the present inventors have found that in addition to the amount of the catalyst, the reaction temperature, the reaction solvent, etc., the amount of the catalyst, the reaction temperature, the reaction solvent, etc. It was found that the terminal structure of the polymer exerts a great influence, and further that the prepolymer obtained by using mercaptan having a larger number of carbon atoms than mercaptopropionic acid as a chain transfer agent, markedly suppresses coloring, Has been completed.

That is, the present invention relates to the general formula HOOC- (CH
₂ ) n-SH (n is an integer of 3 to 12) (hereinafter, referred to as a mercaptan compound) in the presence of a radical-polymerizable monomer, which is obtained by radically polymerizing a carboxyl group at one end of the molecule. A method for producing a macromonomer, which comprises reacting a polymer having a group (hereinafter referred to as a prepolymer) with a radically polymerizable monomer having a glycidyl group in the presence of a catalyst. Hereinafter, the present invention will be described in more detail.

The mercaptan compound in the present invention reacts with a growing radical as a chain transfer agent in a radical polymerization reaction to generate a radical HOOC- (CH ₂ ) n-S., Which initiates polymerization of a monomer. Because it becomes an agent,
Polymerization in the presence of a mercaptan compound gives a polymer having a carboxyl group at one end of the molecule.

Specific examples of mercaptan compounds include γ
-Mercaptobutyric acid and 11-mercaptoundecanoic acid can be mentioned, and γ-mercaptobutyric acid is preferable.

The preferred amount of mercaptan compound used is
1 to 1 per 100 parts by weight of the monomer used for radical polymerization
0 parts by weight. The molecular weight of the resulting prepolymer is controlled by the amount of the mercaptan compound used. When the amount of the mercaptan compound is about 1 part by weight, the number average molecular weight of the prepolymer is about 10,000. The number average molecular weight of the polymer is about 1,500.
Becomes

Monomers used in radical polymerization to obtain a prepolymer include styrene, vinyltoluene, vinylbenzyl chloride, acrylonitrile, vinyl acetate, and (meth) acrylic acid having an alkyl group with 1 to 18 carbon atoms. Examples thereof include alkyl, 2-hydroxyethyl methacrylate, perfluoroalkyl (meth) acrylate, acrylamide and the like, and these are used alone or as a mixture of two or more kinds. In the present specification, the term meta (acrylic) refers to both acrylic and methacrylic.

As the polymerization initiator, azo type initiators such as 2,2'-azobisisobutyronitrile (hereinafter abbreviated as AIBN) and azobisdimethylvaleronitrile are preferable, and the amount thereof is the above-mentioned radical. Polymerizable monomer 1
It is preferably 0.10 to 5.0 parts by weight, more preferably 0.5 to 2.0 parts by weight, per 00 parts by weight. 0.
If it is less than 1 part by weight, the polymerization conversion rate of the used monomer becomes poor, while if it exceeds 5 parts by weight, the prepolymer obtained contains a large amount of a polymer containing no carboxyl group.
When an organic peroxide is used as the polymerization initiator, the added mercaptan compound does not act effectively as a chain transfer agent, and the purity of the obtained macromonomer is poor.

The organic solvent that can be used is generally one that dissolves the prepolymer obtained by radical polymerization and that is inert during the reaction, such as benzene, toluene, xylene, ethyl acetate, Butyl acetate, methoxymethyl acetate, ethoxyethyl acetate, dioxane, methyl ethyl ketone, methyl isobutyl ketone,
Cyclohexane, isopropyl alcohol, propylene glycol monomethyl ether, N, N-dimethylformamide and the like are preferably used alone or as a mixture of two or more kinds.

The polymerization temperature may be about 70 to 100 ° C., and the reaction time for the polymerization is usually 7 to 12 hours.

The amount of carboxyl groups in the prepolymer obtained by the above radical polymerization can be known by measuring the acid value of the prepolymer. The acid value can be determined by reprecipitation purification of the prepolymer with methanol or the like, and then alcohol. It is measured by the method of titrating with a neutral KOH solution.

Next, the production of macromonomer will be described. Macromonomer is a radical polymerizable monomer having a glycidyl group shown below and a prepolymer in an organic solvent,
By heating to 70-150 ° C in the presence of a catalyst,
Glycidyl groups react with the carboxyl groups in the prepolymer to form. The organic solvent used may be of the same type as the prepolymer polymerization solvent, and the macromonomerization reaction is usually carried out in the prepolymer solution obtained by the above-mentioned polymerization operation.

As the radically polymerizable monomer having a glycidyl group (hereinafter referred to as a glycidyl group-containing monomer), glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether and N- [4- (2,3-epoxypropoxy)- 3,5-dimethylbenzyl] acrylamide and the like.

The amount of the glycidyl group-containing monomer used is preferably 0.90 of the carboxyl group amount in the prepolymer.
~ 1.5 times equivalent. When the amount is less than 0.90 times equivalent, the amount of glycidyl groups is too small with respect to the amount of carboxyl groups at the end of the prepolymer, and a large amount of unreacted prepolymer remains. On the other hand, when the amount exceeds 1.5 times the equivalent, in addition to the reaction with the terminal carboxyl group of the prepolymer, for example, as a result of the reaction between the glycidyl group and the carboxyl group, the hydroxyl group in the macromonomer and further the glycidyl group-containing monomer are generated. React, and it is difficult to obtain a high-purity macromonomer.

As the catalyst, a tertiary amine, a quaternary ammonium salt, a quaternary phosphonium salt or the like can be used, and a quaternary ammonium salt or a quaternary phosphonium salt having catalytic activity even under mild conditions is more preferable. Specifically as a catalyst,
Tertiary amines such as triethylamine, tripropylamine, tetramethylethylenediamine, N, N-dimethylaniline, dimethyllaurylamine, triethylbenzylammonium chloride, trimethylcetylammonium bromide, trimethylbenzylammonium chloride, tetrabutylammonium chloride, tetrabutylammonium Examples thereof include quaternary ammonium salts such as bromide, quaternary phosphonium salts such as triphenylbutylphosphonium bromide and tetrabutylphosphonium bromide. Particularly preferred are tetrabutylammonium bromide and tetrabutylphosphonium bromide.

The preferred amount of catalyst used is Prepolymer 1
0.10 to 3.0 parts by weight per 00 parts by weight,
The range of 0.50 to 2.0 parts by weight is more preferable. 0.1
If it is less than 0 parts by weight, it is necessary to continue the reaction at a high temperature for a long time in order to complete the macromonomerization reaction, and as a result, the reaction liquid is colored. On the other hand, if the amount exceeds 3.0 parts by weight, the reaction liquid is likely to be colored.

Further, in order to prevent the generated macromonomer or glycidyl group-containing radically polymerizable monomer from polymerizing during the macromonomerization reaction, a radical polymerization inhibitor such as hydroquinone or hydroquinone monomethyl ether is used in an amount of 10 to 10%. It is advisable to add 500 ppm, and further aerate air or oxygen gas into the reaction solution.

[0022]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples. In addition, the part in each example means a weight part and% means weight%. Hazen color number is JIS K
-6901-K and the number average molecular weight (M
n) and the weight average molecular weight (Mw) are the polystyrene conversion values measured by gel permeation chromatography (GPC).

Example 1 A flask equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer and a nitrogen gas inlet was mixed with 70 parts of toluene, 100 parts of MMA (methyl methacrylate) and 2.3 parts of γ-mercaptobutyric acid. While charging the liquid and ventilating nitrogen gas,
The liquid temperature is maintained at 90 ° C. The AIB No. An initiator solution prepared by dissolving 75 parts in 30 parts of toluene was placed in a dropping funnel and added dropwise in 5 hours. Thereafter, the temperature was kept at 90 ° C. for another 3 hours and then cooled to complete the polymerization. The amount of MMA in the obtained colorless and transparent prepolymer solution was analyzed by gas chromatography, and the polymerization conversion rate of MMA determined from the value was 99%.
Met. The acid value of this prepolymer solution is 0.0
74 meq. / G (liquid), the acid value of the prepolymer itself is 0.150 meq. / G. The number average molecular weight Mn and the weight average molecular weight Mw are 5450, respectively.
And 13500.

Next, 200 parts of the above prepolymer solution (100 parts of prepolymer solid content) was added to 0.02 parts of hydroquinone monomethyl ether (hereinafter abbreviated as MQ) and tetrabutylammonium bromide (hereinafter abbreviated as TBAB).
0.9 parts, and glycidyl methacrylate (hereinafter GMA
2.3 parts (1.1 times equivalent of acid value) was added, and the mixture was reacted at 90 ° C. for 6 hours while passing air. The conversion rate of carboxyl groups determined from the decrease in acid value was 99.2%, and a macromonomer solution having a concentration of 52% was obtained. The Mn and Mw of this macromonomer are 5500 and 1380, respectively.
0, and the degree of coloring of this macromonomer solution was 40 in Hazen color number.

60 parts of this macromonomer reaction liquid,
60 parts of MMA, 10 parts of acrylic acid, 2 parts of AIBN and 120 parts of toluene were charged and radical polymerization was carried out at 80 ° C. As a result, a graft polymer of Mn18000 and Mw45000 was obtained, and no peak of unreacted macromonomer was found in the GPC chart. .. From this fact, it was confirmed that this macromonomer has a good graft polymerization property.

An acid value of 0.08 was prepared in the same manner as in Example 1 except that 3.5 parts of 11-mercaptoundecanoic acid was used.
9 meq. / G (liquid) of a colorless transparent prepolymer solution (acid value of prepolymer; 0.178 meq./g) was obtained. The Mn and Mw of this prepolymer are 540 each.
It was 0,13300. This prepolymer solution 200
The same amount of MQ, TBAB, and GMA as in Example 1 was added to 1 part (100 parts of prepolymer solid content) and macromonomerization was performed in the same manner to obtain a macromonomer solution having a Hazen index of 50. Mn and Mw of this macromonomer were 5200 and 14000, respectively.

Examples 3 to 6 and Comparative Examples 1 to 3 Prepolymers were synthesized in the same manner as in Example 1 using the compounds shown in Table 1, and the obtained prepolymers were acidified with prepolymers. A macromonomer was obtained by reacting with 1.1 times equivalent of GMA at a temperature of 90 ° C. The Hazen color number of the obtained macromonomer solution is as shown in Table 1. The abbreviations in the table are as follows. MIBK: methyl isobutyl ketone, St: styrene,
BA: butyl acrylate, MBA: γ-mercaptobutyric acid, MUA: 11-mercaptoundecanoic acid, TGA:
Mercaptoacetic acid, MPA: 3-mercaptopropionic acid, TBAB: tetrabutylammonium bromide,
TBAC: Tetrabutylammonium chloride, TB
PB: tetrabutylphosphonium bromide, GMA:
Glycidyl methacrylate

As shown in Table 1, the macromonomers obtained by the present invention are TGA (mercaptoacetic acid) and MPA.
As compared with the macromonomer of Comparative Example using (3-mercaptopropionic acid), the degree of coloration is significantly reduced, which shows that it is excellent.

[Table 1]

[0029]

EFFECTS OF THE INVENTION According to the present invention, it is possible to easily produce a macromonomer with extremely little coloration without the need for a complicated treatment step of decolorizing with a decolorizing agent, and to use the macromonomer produced by the present invention in another radical polymerization. The graft copolymer obtained by copolymerizing with a polymerizable monomer also has extremely little coloring, and can be used in a wide range of applications.

Claims (1)

[Claims] 1. A molecule obtained by radically polymerizing a radically polymerizable monomer in the presence of a compound represented by the general formula HOOC- (CH ₂ ) n —SH (n is an integer of 3 to 12). A method for producing a macromonomer, which comprises reacting a polymer having a carboxyl group at one end thereof with a radically polymerizable monomer having a glycidyl group in the presence of a catalyst.