JP2010018690A - Manufacturing method of acrylic copolymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an acrylic copolymer that wipes out concern about safety and prevention of disaster which is the most important problem by solving problems for the manufacture such as agitation, heat removal and the like from an industrial standpoint. <P>SOLUTION: The manufacturing method of the acrylic copolymer comprises neutralizing, with a basic compound, an acrylic copolymer having an acid value of 10-130 mg-KOH obtained by radical copolymerization of acrylic monomers comprising an acrylic monomer derived from dicyclopentadiene using an α-styrene dimer of the structural formula shown in the figure. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing an acrylic copolymer, which is easy to control the temperature during production and can produce an acrylic resin in a relatively short time.

  Acrylic resins are abundant in the types of acrylic monomers that are used as raw materials, and the physical and chemical properties such as adhesion, adhesion, hardness, transparency, light resistance, weather resistance, and chemical resistance are optionally controlled. It can be used for a wide range of applications such as optical coatings for displays, lenses, optical films, adhesives and adhesives used in these, paints, sealing materials, paper strength enhancers, dental materials, aircraft and automotive parts And used.

  Acrylic resins generally generate a large amount of heat during polymerization and become more viscous as the polymerization progresses, so industrially compared heat removal such as solution polymerization, emulsion polymerization, and suspension polymerization using water or an organic solvent as a medium. It is often manufactured by an easy method. Further, when used for special purposes such as casting, it may be used as a partially polymerized syrup.

  There has been proposed a method for producing an acrylic partial polymer in which heat removal in a reaction system can be easily controlled even in the case of radical polymerization by heat in the absence of a solvent for an acrylic monomer (see Patent Document 1). Although it is said that radical polymerization is performed in the absence of a solvent, the technique proposed in Patent Document 1 is compatible with an acrylic monomer and has little polymerization inhibition, such as hydrogen of an alcohol-modified dicyclopentadiene resin. , A rosin containing 40% by weight or more of a rosin component having a tetrahydroabietic acid type skeleton, a derivative of the rosin, and an acrylic monomer in the presence of a tackifying resin. This technique is not suitable for the purpose of obtaining acrylic resin. Therefore, the use of the manufactured acrylic resin is limited to the pressure-sensitive adhesive.

  Moreover, in patent document 1, although the kind of acrylic monomer is not specifically limited, it is inevitable that it is practically restricted by compatibility with the tackifier resin, and the produced acrylic resin is also included. It is easily guessed that the presence of the tackifying resin similarly applies a brake at the stage where the physical properties and chemical properties are further improved.

2,4-diphenyl-4-methyl-1-pentene (= α-methylstyrene dimer), radically polymerized ethylenically unsaturated compound (= acrylic monomer) having a methacryloyl group in the presence of a radical polymerization initiator A method for producing a block copolymer has been proposed (see Patent Document 2). In the technique proposed in Patent Document 2, the amount of 2,4-diphenyl-4-methyl-1-pentene (weight ratio) and the amount of polymerization initiator (weight ratio) with respect to the acrylic monomer are limited. The relationship between the amount of 2,4-diphenyl-4-methyl-1-pentene (number of moles) and the amount of polymerization initiator (number of moles) is not defined. Although it may be possible to produce block copolymers as proposed, it is more important for the production of acrylic resins, and there is nothing about the fundamental safety issues such as stirring and heat removal from polymerization heat. No consideration has been given. In Patent Document 2, it is proposed to produce an acrylic resin by solution polymerization that is easy to stir and remove heat. Even if a block copolymer is produced, removing the organic solvent from the acrylic resin produced in the form of a solution of the organic solvent and taking out only the acrylic resin requires a great deal of energy and labor as easily guessed. . At the same time, the yield is greatly reduced. From the viewpoint of LCA (Life Cycle Assessment) and PRTR Law (Pollutant Release and Transfer Register; a law regarding the grasp of emissions of specific chemicals to the environment and promotion of improvement in management), it is not a practical means.
JP 2003-128714 A JP 2000-169531 A

  Provided is a method for producing an acrylic copolymer that solves manufacturing problems such as stirring and heat removal from an industrial standpoint and dispels safety and disaster prevention concerns, which are the most important issues.

  The present invention provides an α-methylstyrene dimer having the following structural formula

0.02-1.00 mol of polymerization initiator is used per 1.0 mol, and is represented by the following structural formula

(Here, R1 represents a hydrogen atom or a methyl group, and R2 represents a hydrogen atom, a hydroxyalkyl group having 2 to 4 carbon atoms, or an alkyl group having 1 to 8 carbon atoms.)
This is a method for producing an acrylic copolymer, in which an acrylic copolymer having an acid value of 10 to 130 mgKOH obtained by radical copolymerization of an acrylic monomer containing an acrylic monomer is neutralized with a basic compound.

  According to the method for producing an acrylic copolymer of the present invention, it is possible to solve the problems in safety and disaster prevention such as avoiding the process leading to rapid polymerization reaction and runaway reaction, control of the process, stirring and heat removal.

  In the method for producing an acrylic copolymer of the present invention, an acrylic copolymer having water dispersibility or water solubility and useful as a polymer emulsifier for emulsion polymerization of an acrylic monomer can be produced. The acrylic emulsion emulsion-polymerized according to this method is excellent in water resistance, chemical resistance and mechanical strength. Moreover, it is excellent in adhesiveness and dispersibility of highly functional materials such as carbon fiber, glass fiber, and titanium whisker.

  The present invention provides an α-methylstyrene dimer having the following structural formula

0.02-1.00 mol of polymerization initiator is used per 1.0 mol, and is represented by the following structural formula

(Here, R1 represents a hydrogen atom or a methyl group, and R2 represents a hydrogen atom, a hydroxyalkyl group having 2 to 4 carbon atoms, or an alkyl group having 1 to 8 carbon atoms.)
This is a method for producing an acrylic copolymer, in which an acrylic copolymer having an acid value of 10 to 130 mgKOH obtained by radical copolymerization of an acrylic monomer containing an acrylic monomer is neutralized with a basic compound.

  In the method for producing an acrylic copolymer of the present invention, α-methylstyrene dimer having the following structural formula

That is, 2,4-diphenyl-4-methyl-1-pentene is used.

  As α-methylstyrene dimer, ie, 2,4-diphenyl-4-methyl-1-pentene, for example, it is manufactured by Goi Kasei Co., Ltd., Honshu Chemical Industry Co., Ltd., Asahi Kasei Finechem Co., Ltd. Can be arbitrarily selected and used.

  In the method for producing an acrylic copolymer of the present invention, a polymerization initiator is used. Examples of the polymerization initiator include organic peroxides such as benzoyl peroxide, t-butylperoxy-2-ethylhexanoate, and t-butylperoxybenzoate, and 2,2′-azobis (4-methoxy-2,4 -Dimethylvaleronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 2,2-azobis [2- (2-imidazolin-2-yl And organic azo polymerization initiators such as propane] and persulfates such as potassium persulfate and ammonium persulfate. In the method for producing an acrylic copolymer of the present invention, these polymerization initiators may be used alone or in a mixture of two or more.

  In the acrylic copolymer of the present invention, among these polymerization initiators, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2, 4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 2,2-azobis [2- (2-imidazolin-2-yl) propane] and the like are preferably recommended. The safety at the time of manufacturing the acrylic copolymer and the stability of the acrylic copolymer are compatible.

  In the method for producing an acrylic copolymer of the present invention, 0.02 to 1.00 mol of a polymerization initiator is used with respect to 1.0 mol of α-methylstyrene dimer.

  The polymerization initiator is preferably used in an amount of 0.02 to 0.80 mol, more preferably 0.02 to 0.66 mol, per mol of α-methylstyrene dimer. In the method for producing an acrylic copolymer of the present invention, when the amount of the polymerization initiator used is less than 0.02 mol, the polymerization rate does not increase, which is not a practical method from an industrial viewpoint. When the amount of the polymerization initiator used exceeds 1.00 mol, the heat generated during the production of the acrylic copolymer is large and a runaway reaction is likely to occur, which is a safety problem.

  Furthermore, in the method for producing an acrylic copolymer of the present invention, in order to more safely control the polymerization temperature, the polymerization initiator is preferably 0.05 to 5% by weight with respect to 100 parts by weight of the acrylic monomer. Parts, more preferably 0.08 to 3 parts by weight, still more preferably 0.10 to 2.5 parts by weight. In the method for producing an acrylic copolymer of the present invention, when the amount of the polymerization initiator used is 0.05 to 5 parts by weight, an abnormal polymerization reaction or rapid heat generation tends not to occur.

  In the method for producing an acrylic copolymer of the present invention, it is represented by the following structural formula.

(Here, R1 represents a hydrogen atom or a methyl group, and R2 represents a hydrogen atom, a hydroxyalkyl group having 2 to 4 carbon atoms, or an alkyl group having 1 to 8 carbon atoms.)
Acrylic monomers including acrylic monomers are used.

  In the method for producing an acrylic copolymer of the present invention, it is represented by the following structural formula.

(Here, R1 represents a hydrogen atom or a methyl group, and R2 represents a hydrogen atom, a hydroxyalkyl group having 2 to 4 carbon atoms, or an alkyl group having 1 to 8 carbon atoms.)
As acrylic monomers, acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate , Methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, tertiary butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, methacryl Examples thereof include isobutyl acid, tertiary butyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate and the like. In the method for producing an acrylic copolymer of the present invention, these acrylic monomers may be used alone or in a mixture of two or more.

  Furthermore, in the method for producing an acrylic copolymer of the present invention, preferably, N, N-dimethylaminoethyl acrylate, N, N-diethylaminoethyl acrylate, N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate Amino group-containing acrylic monomers such as 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine, tertiary-amino such as 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidine Group-containing acrylic monomers, acrylamide, N, N-dimethylacrylamide, isopropylacrylamide, hydroxymethylacrylamide, hydroxyethylacrylamide, N, N-dimethylaminopropylacrylamide, diacetone acrylamide, etc. Epoxy group-containing acrylic monomers such as acryl monomer, urea group-containing acrylic monomers such as 3-methacryloyloxyethylethylene urea, glycidyl acrylate, glycidyl methacrylate, methyl glycidyl methacrylate, p-vinylbenzyl glycidyl ether Acrylic monomers such as acrylic monomers derived from dicyclopentadiene such as dicyclopentanyloxyethyl acrylate, dicyclopentenyloxyethyl acrylate, dicyclopentanyloxyethyl methacrylate, dicyclopentenyloxyethyl methacrylate Illustrated. In the method for producing an acrylic copolymer of the present invention, these acrylic monomers may be used alone or in a mixture of two or more.

  In the method for producing an acrylic copolymer according to the present invention, among these acrylic monomers, the following structural formula is preferable.

(Here, R3 represents a hydrogen atom or a methyl group, and x represents 0, 1, or 2.)
Acrylic monomers derived from dicyclopentadiene are recommended.

  In the method for producing an acrylic copolymer of the present invention, the acrylic monomer derived from dicyclopentadiene includes dicyclopentenyloxy acrylate, dicyclopentenyloxyethyl acrylate, dicyclopentenyloxy methacrylate, dicyclopentenyloxyethyl. Examples include methacrylate. In the method for producing an acrylic copolymer of the present invention, these acrylic monomers derived from dicyclopentadiene may be used alone or in a mixture of two or more.

  In the method for producing an acrylic copolymer of the present invention, a crosslinking point or a graft point is preferably formed in the acrylic copolymer by copolymerizing an acrylic monomer derived from dicyclopentadiene.

  It is possible to produce an acrylic polymer imparted with mechanical properties and completely different chemical properties by radical polymerization of another acrylic monomer in the presence of the acrylic copolymer. Here, in the method for producing an acrylic copolymer according to the present invention, another chemical property is a new acrylic polymer produced by radical polymerization of another acrylic monomer in the presence of the acrylic copolymer. By the action, it refers to imparting adhesiveness to many materials.

  In the method for producing an acrylic copolymer of the present invention, the acid value of the acrylic copolymer is 10 to 130 mgKOH, preferably 20 to 70 mgKOH, and more preferably 30 to 55 mgKOH. In the acrylic copolymer of the present invention, when the acid value of the acrylic copolymer is less than 10 mgKOH, the water dispersibility and water solubility of the acrylic copolymer are deteriorated and the function as an emulsifying polymer is lost. When the acid value of the acrylic copolymer exceeds 130 mgKOH, the water resistance and alkali resistance deteriorate.

  In the method for producing an acrylic copolymer of the present invention, the number average molecular weight of the acrylic copolymer is preferably 500 to 100,000, more preferably 1000 to 80,000, and still more preferably 2000 to 60,000. Is recommended. In the method for producing an acrylic copolymer of the present invention, when the acrylic copolymer has a number average molecular weight of 500 to 100,000, when the acrylic copolymer is used as an emulsifying polymer, there are few aggregates and mechanical stability. There is a tendency to produce excellent acrylic emulsions. Here, in the method for producing an acrylic copolymer of the present invention, the molecular weight of the acrylic copolymer is determined by gel permeation chromatography (hereinafter also referred to as GPC) “HLC-8220GPC” (test equipment of Tosoh Corporation). It was measured using tetrahydrofuran as the carrier and polymethyl methacrylate as the molecular weight standard.

  In the method for producing an acrylic copolymer of the present invention, the radical copolymerized acrylic copolymer having an acid value of 10 to 130 mgKOH is neutralized with a basic compound.

  In the method for producing an acrylic copolymer of the present invention, the basic compound used for neutralizing the acrylic copolymer is defined as an Arrhenius base, a Bronsted base, or a Lewis base. In the method for producing an acrylic copolymer of the present invention, the basic compound is preferably exemplified by ammonia and nitrogen compounds such as triethylamine and N, N-dimethylethanolamine, sodium hydroxide and potassium hydroxide. . In the method for producing an acrylic copolymer of the present invention, these basic compounds may be used alone or in a mixture of two or more.

  In the method for producing an acrylic copolymer of the present invention, the neutralization rate of the acrylic copolymer is preferably 20 to 100%, more preferably 45 to 95%, and still more preferably 60 to 90%. It is desirable to use basic compounds. In the method for producing an acrylic copolymer of the present invention, when a basic compound is used so that the neutralization rate of the acrylic copolymer is 20 to 100%, the water dispersibility of the acrylic copolymer or the water solubility is obtained. When the acrylic copolymer of the present invention is used as a polymer emulsifier and an acrylic monomer is subjected to emulsion polymerization, an acrylic emulsion with little aggregates is produced.

  In the method for producing an acrylic copolymer of the present invention, an acrylic monomer containing a specific acrylic monomer is radically copolymerized.

  In the method for producing an acrylic copolymer of the present invention, it is preferable that the acrylic copolymer be used as a purification step such as separation, removal and drying of the acrylic copolymer from a solvent, a polymer for emulsion polymerization, and the like. Due to its properties, it is recommended to produce it by bulk polymerization.

  In the method for producing an acrylic copolymer of the present invention, bulk radical copolymerization is one of methods used for radical copolymerization of a monomer having a vinyl group such as an acrylic monomer or a styrene monomer. Without using a solvent, polymerization is carried out by heating only a monomer having a vinyl group such as an acrylic monomer or a styrene monomer, or by adding a polymerization initiator such as azobisisobutyronitrile or benzoyl peroxide. Is the method.

  The feature of bulk radical copolymerization is that the polymerization rate is high and a relatively pure polymer is produced in bulk. In conventional bulk radical copolymerization, regardless of the production scale, it is difficult to control the polymerization temperature, such as difficult to remove the polymerization heat (difficult to remove heat) and local heating (local runaway reaction occurs). is there.

  In the method for producing an acrylic copolymer of the present invention, the acrylic copolymer is produced by using 0.02 to 1.00 mol of a polymerization initiator with respect to 1 mol of α-methylstyrene dimer. Even in the case of copolymerization, stirring and heat removal during production are easy, and the polymerization temperature can be sufficiently controlled from an industrial standpoint.

  In the method for producing an acrylic copolymer according to the present invention, when the acrylic copolymer is produced by bulk radical polymerization, the oxygen concentration in the gas phase part of the production vessel substituted with the inert gas is preferably 0.02 vol. % ≦ gas phase oxygen concentration ≦ 8.0 vol%, more preferably 0.05 vol% ≦ gas phase oxygen concentration ≦ 8.0 vol%, even more preferably 0.2 vol% ≦ gas phase oxygen concentration ≦ 6 It is desirable to carry out in an atmosphere of 0.0 vol%. In the method for producing an acrylic copolymer of the present invention, if the gas phase oxygen concentration is 0.02 vol% ≦ gas phase oxygen concentration ≦ 8.0 vol%, the acrylic monomer causes a polymerization reaction in the gas phase portion. The acrylic copolymer can be produced safely and efficiently.

  In the method for producing an acrylic copolymer of the present invention, the oxygen concentration in the polymerization system was measured using “Digital Oxygen Concentrator XO-326ALB” (oxygen concentration measuring instrument of New Cosmos Electric Co., Ltd.). Moreover, in the manufacturing method of the acrylic copolymer of this invention, the inert gas used by this invention can be arbitrarily selected from what is marketed, such as nitrogen gas and helium gas.

  Further, in the method for producing an acrylic copolymer of the present invention, when the gas phase oxygen concentration is controlled by blowing an inert gas or a mixed gas of inert gas / air, the inert gas or the inert gas is used. It is recommended that the / air mixture gas be at a temperature sufficiently low that radical polymerization of the acrylic monomer is not initiated. In the method for producing an acrylic copolymer of the present invention, from this viewpoint, the temperature of the inert gas or the mixed gas of inert gas / air is preferably as low as possible, but is preferably 40 ° C. or less, more preferably 30 ° C. or less. It is recommended that the temperature be 25 ° C. or lower. In the method for producing an acrylic copolymer of the present invention, if the temperature of the inert gas or the inert gas / air mixed gas is preferably 40 ° C. or less, the acrylic copolymer present in the gas phase part of the acrylic copolymer production vessel is used. The vapor of the monomer is cooled, and the acrylic monomer tends to be less likely to cause radical polymerization in the gas phase part of the acrylic copolymer production vessel, the vessel wall, the condenser, etc., and the acrylic copolymer can be produced more safely. There is a trend.

  In the manufacturing method of the acrylic copolymer of this invention, when manufacturing an acrylic copolymer by block radical copolymerization, it illustrates as follows.

  In a polymerization vessel equipped with a stirrer, a thermometer, an inert gas introduction tube, a condenser, and a monomer dropping device, an acrylic monomer such as n-butyl methacrylate, α-methylstyrene dimer, α-methylstyrene dimer 1. A polymerization initiator corresponding to 0.02 to 1.00 mol, for example 0.1 mol, is charged per 0 mol, and the temperature is raised to a predetermined polymerization temperature. When a predetermined polymerization temperature is reached, an acrylic copolymer can be produced by carrying out the polymerization reaction until the target polymerization rate is reached.

  In the method for producing an acrylic copolymer of the present invention, the polymerization temperature can be easily controlled. In the production method by the illustrated bulk radical copolymerization, other solution radical copolymerization, emulsion radical copolymerization or suspension radical copolymerization can be used. Even if it exists, the abnormal polymerization reaction which cannot be controlled, and rapid heat_generation | fever are not seen, but an acrylic copolymer can be manufactured safely within the normal control range.

  In the method for producing an acrylic copolymer of the present invention, the number average molecular weight of the acrylic copolymer is preferably 500 to 200,000, more preferably 1000 to 160,000, and still more preferably 2000 to 120,000. Is desirable. In the method for producing an acrylic copolymer according to the present invention, when the number average molecular weight of the acrylic copolymer is in the range of 500 to 200,000, stirring and heat removal tend to be easy when producing the acrylic copolymer. Manufacturing operations can be performed safely.

  In the method for producing an acrylic copolymer of the present invention, it is recommended that the polymerization rate of the acrylic copolymer is preferably 90% or more, more preferably 95% or more, and further preferably 98% or more. . In the method for producing an acrylic copolymer of the present invention, if the polymerization rate of the acrylic copolymer is 90% or more, the risk of bringing in an unreacted acrylic monomer inappropriate to the subsequent process can be minimized. ,desirable.

  The details of the present invention will be described in the following examples. In the following examples, the evaluation method, measurement method, and the like were as follows.

1) Oxygen concentration (vol%)
The measurement was performed using a digital oximeter XO-326ALB (a measuring device manufactured by Shin Cosmos Electric Co., Ltd.).

2) Number average molecular weight (Mn), weight average molecular weight (Mw)
Gel permeation chromatography (GPC) "HLC-8220GPC" (Tosoh Co., Ltd. test equipment) was used, and the measurement was performed using tetrahydrofuran as a carrier and polymethyl methacrylate as a molecular weight standard.

3) Polymerization rate (%)
The heating residue (%) was measured according to JIS K 5407: 1997, and this was defined as the polymerization rate (%). However, the measurement temperature was 140 ° C. and the measurement time was 60 minutes.

4) Acid value (mgKOH)
Measured according to JIS K 5407: 1997.

Example 1
In a 2 L four-necked flask having a nitrogen gas inlet tube, a reflux condenser, a stirring device, and an acrylic monomer charging port, 200 g of n-butyl methacrylate, 750 g of 2-ethylhexyl methacrylate, 50 g of methacrylic acid, α-methylstyrene dimer 144.0 g (0.610 mol), 2,2-azobisisobutyronitrile 10.0 g (0.061 mol) (when the number of moles of α-methylstyrene dimer is 1.0 mol, 2,2- The number of moles of azobisisobutyronitrile is 0.10 mol.) (1.0% when the total amount of acrylic monomers is 100 parts by weight) is added and the temperature is raised to 95 ° C. for 30 minutes. Warm up. Thereafter, polymerization was carried out until the polymerization rate reached 98% or more (about 6 hours), and the mixture was cooled to room temperature. 4-Dimethylaminoethanol 41.9g was added so that the neutralization rate might be 80%, and acrylic copolymer AC-1 was manufactured.

  The acrylic copolymer AC-1 had a number average molecular weight of 15000, a weight average molecular weight of 21,800, a molecular weight distribution of 1.45, a polymerization rate of 98%, and an acid value of 33.0 mgKOH.

  During the production of the acrylic copolymer AC-1, abnormal polymerization reaction, rapid exotherm, etc. were not observed. The production of the acrylic copolymer was safe without any problems.

Example 2
In a 2 L four-necked flask having a nitrogen gas inlet tube, a reflux condenser, a stirring device, and an acrylic monomer charging port, 200 g of n-butyl methacrylate, 700 g of 2-ethylhexyl methacrylate, 50 g of dicyclopentenyloxyethyl methacrylate, methacryl 50 g of acid, 144.0 g (0.610 mol) of α-methylstyrene dimer, 10.0 g (0.061 mol) of 2,2-azobisisobutyronitrile (1.0 mol of α-methylstyrene dimer The molar number of 2,2-azobisisobutyronitrile is 0.10 mol when it is mol) (1.0% when the total amount of acrylic monomers is 100 parts by weight). The temperature was raised to 95 ° C. in 30 minutes. Thereafter, polymerization was carried out until the polymerization rate reached 98% or more (about 6 hours), and the mixture was cooled to room temperature. 4-Dimethylaminoethanol 41.9g was added so that the neutralization rate might be 80%, and acrylic copolymer AC-2 was manufactured.

  The acrylic copolymer AC-2 had a number average molecular weight of 16000, a weight average molecular weight of 23,000, a molecular weight distribution of 1.44, a polymerization rate of 98%, and an acid value of 32.5 mgKOH.

  During the production of the acrylic copolymer AC-2, abnormal polymerization reaction, rapid exotherm, etc. were not observed. The production of the acrylic copolymer was safe without any problems.

Example 3
In a 2 L four-necked flask having a nitrogen gas inlet tube, a reflux condenser, a stirring device, and an acrylic monomer charging port, 200 g of n-butyl methacrylate, 535 g of 2-ethylhexyl methacrylate, 100 g of dicyclopentenyloxyethyl methacrylate, acrylic 45 g of acid, 120 g of 2-hydroxyethyl methacrylate, 144.0 g (0.610 mol) of α-methylstyrene dimer, 10.0 g (0.061 mol) of 2,2-azobisisobutyronitrile (α-methylstyrene) When the number of moles of dimer is 1.0 mole, the number of moles of 2,2-azobisisobutyronitrile is 0.10 mole.) (1. When the total amount of acrylic monomers is 100 parts by weight) The temperature was raised to 95 ° C. in 30 minutes. Thereafter, polymerization was carried out until the polymerization rate reached 98% or more (about 6 hours), and the mixture was cooled to room temperature. 4-Dimethylaminoethanol 44.4g was added so that the neutralization rate might be 80%, and acrylic copolymer AC-3 was manufactured.

  The acrylic copolymer AC-3 had a number average molecular weight of 16000, a weight average molecular weight of 23,000, a molecular weight distribution of 1.44, a polymerization rate of 98%, and an acid value of 35.0 mgKOH.

  During the production of the acrylic copolymer AC-3, abnormal polymerization reaction, rapid exotherm, etc. were not observed. The production of the acrylic copolymer was safe without any problems.

Example 4
In a 2 L four-necked flask having a nitrogen gas inlet tube, reflux condenser, stirring device, and acrylic monomer charging port, 535 g of n-butyl acrylate, 200 g of benzyl methacrylate, 100 g of dicyclopentenyloxyethyl methacrylate, 45 g of acrylic acid 2-hydroxyethyl methacrylate 120 g, α-methylstyrene dimer 192.0 g (0.814 mol), 2,2-azobisisobutyronitrile 20.0 g (0.122 mol) (of α-methylstyrene dimer) When the number of moles is 1.0 mole, the number of moles of 2,2-azobisisobutyronitrile is 0.150 moles.) (2.0% when the total amount of acrylic monomers is 100 parts by weight) The temperature was raised to 95 ° C. in 30 minutes. Thereafter, the polymerization was performed until the polymerization rate reached 98% or more (about 12 hours), and the mixture was cooled to room temperature. 4-Dimethylaminoethanol 44.4g was added so that the neutralization rate might be 80%, and acrylic copolymer AC-4 was manufactured.

  The acrylic copolymer AC-4 had a number average molecular weight of 7200, a weight average molecular weight of 15800, a molecular weight distribution of 2.19, a polymerization rate of 98%, and an acid value of 35.0 mgKOH.

  During the production of the acrylic copolymer AC-4, abnormal polymerization reaction, rapid exotherm, etc. were not observed. The production of the acrylic copolymer was safe without any problems.

Example 5
While blowing nitrogen gas adjusted to 20 ° C. into a 2 L four-necked flask having a nitrogen gas inlet tube, a reflux condenser, a stirring device, and an acrylic monomer charging port, 200 g of n-butyl methacrylate and 2-methyl methacrylate 535 g of ethylhexyl, 100 g of dicyclopentenyloxyethyl methacrylate, 45 g of acrylic acid, 120 g of 2-hydroxyethyl methacrylate, 144.0 g (0.610 mol) of α-methylstyrene dimer, 2,2-azobisisobutyronitrile. 0 g (0.061 mol) (when the number of moles of α-methylstyrene dimer is 1.0 mole, the number of moles of 2,2-azobisisobutyronitrile is 0.10 mole) (acrylic monomer) When the total amount of the body is 100 parts by weight, it is 1.0%.) And the oxygen concentration in the gas phase part of the flask is 0. 0.5 vol% or less was confirmed. Nitrogen gas blowing was stopped, the oxygen concentration was adjusted to 5 vol%, nitrogen gas / air adjusted to 20 ° C. was blown, and it was confirmed that the oxygen concentration in the gas phase was 3 vol% or more. Thereafter, during the production of the acrylic copolymer, the oxygen concentration was adjusted to 5 vol%, and nitrogen gas / air whose temperature was adjusted to 20 ° C. was continuously blown.

  The temperature increase was started and the temperature was raised to 95 ° C. in 30 minutes. Thereafter, polymerization was carried out until the polymerization rate reached 98% or more (about 6 hours), and the mixture was cooled to room temperature. 4-Dimethylaminoethanol 44.4g was added so that the neutralization rate might be 80%, and acrylic copolymer AC-5 was manufactured.

  The acrylic copolymer AC-5 had a number average molecular weight of 14500, a weight average molecular weight of 25400, a molecular weight distribution of 1.75, a polymerization rate of 98%, and an acid value of 35.0 mgKOH.

  During the production of the acrylic copolymer AC-5, abnormal polymerization reaction, rapid exotherm, etc. were not observed. The production of the acrylic copolymer was safe without any problems. Further, during the production, polymerization in the gas phase part and the flask wall was not observed, and the production method was much safer.

Comparative Example 1
In a 2 L four-necked flask having a nitrogen gas inlet tube, a reflux condenser, a stirring device, and an acrylic monomer charging port, 200 g of n-butyl methacrylate, 750 g of 2-ethylhexyl methacrylate, 50 g of methacrylic acid, 2,2-azo Preparation of acrylic copolymer by charging 10.0 g of bisisobutyronitrile (1.0% when the total amount of acrylic monomer is 100 parts by weight) and heating to 95 ° C. in 30 minutes Tried.

  Polymerization started abruptly during the temperature increase (about 50 ° C.), and an acrylic copolymer could not be produced due to uncontrollable heat generation.

Comparative Example 2
A 2 L four-necked flask having a nitrogen gas inlet tube, a reflux condenser, a stirrer, and an acrylic monomer charging port was charged with 60 g of n-butyl methacrylate, 225 g of 2-ethylhexyl methacrylate, and 15 g of methacrylic acid at 95 ° C. The temperature rose. 140 g of n-butyl methacrylate, 525 g of 2-ethylhexyl methacrylate, 35 g of methacrylic acid, 10.0 g of 2,2-azobisisobutyronitrile (1.0% when the total amount of acrylic monomers is 100 parts by weight) The mixed solution of A.) was dropped in 3 hours, and an acrylic copolymer was produced.

  A few minutes after the start of dropping (about 5 minutes), the polymerization started abruptly, and the acrylic copolymer could not be produced due to uncontrollable heat generation.

Comparative Example 3
In a 2 L four-necked flask having a nitrogen gas inlet tube, a reflux condenser, a stirring device, and an acrylic monomer charging port, 200 g of n-butyl methacrylate, 750 g of 2-ethylhexyl methacrylate, 50 g of methacrylic acid, α-methylstyrene dimer 24.0 g (0.102 mol), 2,2-azobisisobutyronitrile 20.0 g (0.122 mol) (when the number of moles of α-methylstyrene dimer is 1.0 mol, 2,2- The number of moles of azobisisobutyronitrile is 1.20 moles.) (2.0% when the total amount of acrylic monomers is 100 parts by weight) Warm up.

  After completion of the temperature increase, the rapid progress of the polymerization reaction made it impossible to control the heat generation and remove the heat, and the acrylic copolymer could not be produced.

Comparative Example 4
The acrylic monomer composition is 235 g of n-butyl methacrylate, 750 g of 2-ethylhexyl methacrylate and 15 g of methacrylic acid, and 12.5 g of 2-dimethylaminoethanol used for neutralization so that the neutralization rate is 80%. Acrylic copolymer AC-6 was produced in the same manner as Example 1 except for the above.

  The acrylic copolymer AC-6 had a number average molecular weight of 13200, a weight average molecular weight of 24400, a molecular weight distribution of 1.85, a polymerization rate of 98%, and an acid value of 9.8 mgKOH.

  While ion-exchanged water was gradually added while stirring the acrylic copolymer AC-6, the acrylic copolymer AC-6 became a gel without emulsification.

Comparative Example 5
The acrylic monomer composition is 235 g of n-butyl methacrylate, 600 g of 2-ethylhexyl methacrylate and 200 g of methacrylic acid, and 165.6 g of 2-dimethylaminoethanol used for neutralization so that the neutralization rate is 80%. Acrylic copolymer AC-7 was produced in the same manner as Example 1 except for the above.

  The acrylic copolymer AC-7 had a number average molecular weight of 10,200, a weight average molecular weight of 19,600, a molecular weight distribution of 1.92, a polymerization rate of 98%, and an acid value of 130.5 mgKOH.

  While stirring the acrylic copolymer AC-7, ion exchange water was added little by little to prepare an aqueous solution of the acrylic copolymer AC-7 with a heating residue of 25%. Using this aqueous solution, a film having a dry film thickness of 25 μm was formed on a glass plate and dried at 30 ° C. for 72 hours. After drying, when water drops were dropped in the form of a film, the film was easily re-dissolved and the water resistance was poor.

Test Results of Acrylic Copolymer Emulsion polymerization was performed using the acrylic copolymer AC-3 as a polymer for emulsion polymerization (emulsifier).

  80 g of the acrylic copolymer AC-3 was dissolved in 120 g of methyl methacrylate and 2.4 g of α-methylstyrene dimer, 300 g of ion exchange water was added thereto, and a monomer emulsion was prepared using a homogenizer.

  While blowing nitrogen gas into a 2 L four-necked flask having a nitrogen gas inlet tube, a reflux condenser, a stirrer, and an acrylic monomer charging port, 366 g of ion-exchanged water and 100 g of monomer emulsion (20% of the monomer emulsion) Was heated to 60 ° C. 0.24 g of ammonium persulfate (0.2% of methyl methacrylate) was added, and the temperature was raised to 75 ° C.

  A monomer emulsion 400 g (80% of the monomer emulsion) was added dropwise over 3 hours, and after completion of the addition, polymerization was further performed for 1 hour, followed by cooling to 40 ° C. to produce an acrylic emulsion.

  The produced acrylic emulsion had a heating residue of 28.6%, a weight average molecular weight of 89000 and a stable emulsion.

  It was confirmed that the acrylic emulsion can be produced safely without sudden heat generation during the production of the acrylic emulsion. Further, no agglomerates adhered to the stirring blade, temperature sensor, and flask wall, and the filterability was good.

  Using the produced emulsion, a film having a dry film thickness of 25 μm was formed on a glass plate and dried at 30 ° C. for 72 hours. After drying, water droplets were dropped in the form of a film, but the film did not change even after 1 hour and the water resistance was good.

Claims (3)

Α-methylstyrene dimer of the following structural formula

0.02-1.00 mol of polymerization initiator is used per 1.0 mol, and is represented by the following structural formula

(Here, R1 represents a hydrogen atom or a methyl group, and R2 represents a hydrogen atom, a hydroxyalkyl group having 2 to 4 carbon atoms, or an alkyl group having 1 to 8 carbon atoms.)
A method for producing an acrylic copolymer, comprising neutralizing an acrylic copolymer having an acid value of 10 to 130 mgKOH obtained by radical copolymerization of an acrylic monomer containing an acrylic monomer with a basic compound. The acrylic monomer is represented by the following structural formula

(Here, R3 represents a hydrogen atom or a methyl group, and x represents 0, 1, or 2.)
The manufacturing method of the acrylic copolymer of Claim 1 containing an acrylic monomer. The method for producing an acrylic copolymer according to claim 1, wherein the acrylic copolymer is produced by bulk radical copolymerization.