JP2010100744A - Method for producing acrylic emulsion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an acrylic emulsion having good wettability, compatibility, and adhesiveness to various materials, such as a polyolefin represented by polypropylene or a polyamide represented by nylon. <P>SOLUTION: In the method for producing the acrylic emulsion, an acrylic prepolymer is obtained by bulk polymerization of an acrylic monomer using 0.020-0.400 mole of a polymerization initiator based on 1.0 mole of a dithioester compound, and then the acrylic emulsion is obtained by emulsion polymerization of the acrylic monomer in the presence of the obtained acrylic prepolymer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  Provided is a method for producing an acrylic emulsion having good wettability, compatibility and adhesion to various materials.

  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.

  A method for producing an ABC or ABA block copolymer using radical polymerization of an acrylic monomer has been proposed (see Patent Document 1).

  The technology disclosed in Patent Document 1 is a copolymerization of a methacrylic acid alkyl ester and a methacrylic monomer having a carboxyl group, a hydroxyl group, an epoxy group, a tertiary amino group, etc., for example, a polypropylene resin , Nylon resin, Noryl resin, Polycarbonate resin, ABS resin, PPS resin and other plastics that occupy a major position in the organic polymer market, or Thermosetting epoxy resin, unsaturated polyester resin, phenol resin, polyurethane resin, etc. It seems that functional improvements such as compatibility with adhesive resins, wettability, and adhesiveness are not considered.

  In the technique proposed in Patent Document 1, the amounts of 2,4-diphenyl-4-methyl-1-pentene and polymerization initiator used relative to the acrylic monomer are shown, but 2,4-diphenyl-4-methyl is used. The amount of the polymerization initiator used with respect to -1-pentene (α-methylstyrene dimer) is not specified. Therefore, the heat removal at the time of manufacturing an acrylic macromonomer and an acrylic copolymer by radical polymerization becomes a big subject, and the manufacturing method of an acrylic macromonomer and an acrylic copolymer is limited. That is, it is limited to the case where an acrylic macromonomer and an acrylic copolymer are produced by a production method such as solution polymerization using an organic solvent that is easy to remove heat or emulsion polymerization using water as a medium.

  When an acrylic macromonomer and an acrylic copolymer are produced by solution polymerization in accordance with the technique proposed in Patent Document 1, a low concentration containing a large amount of an organic solvent at a low molecular weight due to concerns about stirring and heat removal during production. Only the acrylic macromonomer and the acrylic copolymer can be produced, and not only limited in use but also industrially less advantageous. Containing a large amount of organic solvent is not preferable from the viewpoint of environmental load.

  Dithioester derivatives and chain transfer agents as reversible addition-open chain transfer agents and methods for producing radically polymerizable polymers using the same have been proposed (see Patent Document 2). According to Patent Document 2, by using a dithioester derivative having a pentafluorophenyl group or a pentafluorobenzyl group in the molecule, for example, 1-phenylethyl-pentafluorophenyl dithioacetate, the dithioester derivative itself The unpleasant odor and the odor of the polymer are suppressed, the molecular weight adjustment is easy, and a low polydispersity polymer is produced.

  The technology proposed in Patent Document 2 does not give any consideration to stirring during production and heat removal from polymerization heat from an industrial standpoint, and avoids difficulty in stirring and heat removal at the manufacturing site. Therefore, it is obvious that the production in an organic solvent is an essential condition. Desolvation of a polymer produced in an organic solvent and removal of the polymer require a great deal of energy and labor, and are not recommended as a practical method. In addition, from the viewpoint of reducing the environmental load, a technique for manufacturing using a large amount of an organic solvent is not desirable.

  A method for producing a polymer having living characteristics using a chain transfer agent (CTA) having a serial transfer constant larger than 0.1, a vinyl monomer, and a polymerization initiator has been proposed (see Patent Document 3). According to Patent Document 3, a vinyl polymer having a CTA free radical residue and a polymerization initiator residue at the end of a low polydispersity polymer is generated under various conditions. However, in Patent Document 3, there is no discussion of stirring and heat removal from an industrial standpoint, and it seems difficult to mass-produce safely and stably.

  Dithioester compounds are widely known as reversible addition-cleavage chain transfer agents. The reversible addition-fragmentation chain transfer agent is generally referred to as a RAFT agent (Reversible Addition-Fragmentation Chain Transfer; RAFT), and is a raw material for conducting living radical polymerization by RAFT polymerization which is one of the main techniques of precision polymerization technology. In RAFT polymerization, radical polymerization reaction is controlled, radical polymerization reaction proceeds by living radical polymerization, and molecular weight distribution (Mw / Mn) obtained by dividing weight average molecular weight (Mw) by number average molecular weight (Mn) (both polydispersity) Can produce small polymers.

  The characteristic of RAFT polymerization is that a polymer having a small molecular weight distribution can be produced from the initial stage of polymerization, and it is difficult to be affected by the types of vinyl monomers such as acrylic monomers used and functional groups such as carboxyl groups and epoxy groups. Taking advantage of this feature, research and examination are actively conducted in the field of advanced science and technology such as stimulus-responsive polymers and drug delivery polymers. As the RAFT agent, 2,2-diphenyl-4-methyl-1-pentene (α-methylstyrene dimer), a dithioester compound, and the like are well known, but polymerization control such as molecular weight is easy, molecular weight Since the distribution is small, many thioester compounds have been studied.

  Regarding the production method of RAFT agent and RAFT polymerization behavior, (1) “Radical Polymerization Handbook” published by NTS, p152-p153 (1999), (2) JP-A-2003-128712, (3) W098 / 01478, (4) W099 / 31144, (5) W000 / 75207, (6) JP 2003-012719, (7) JP 2002-265523, (8) JP 2003-041224, (9) Special Table 2000 It is described in detail in books such as -515181 and patent literature. As seen in these publications and patent documents, research and investigation on the production method of RAFT agent, RAFT polymerization behavior, or polymer production by solution polymerization using RAFT polymerization has been carried out extensively. There is no mention of bulk polymerization, which is an efficient production method.

At present, there are no studies or proposals on polymerization temperature control and production methods from the industrial viewpoint of safe and stable production. Currently, in general, from the viewpoint of heat removal from a large polymerization heat, a study on solution polymerization, in which the polymerization temperature control is easy, is being conducted.
JP 2000-169531 A JP 2007-238646 A Special Table 2000-515181

  Excellent wettability and compatibility with various materials such as polyolefin, typically polypropylene, which is a non-polar plastic that is difficult to adhere, and polyamide, typically nylon, which has polarity and is widely used as engineering plastic. It is an object to provide an acrylic emulsion having solubility and adhesion.

  In the present invention, an acrylic monomer is bulk-polymerized using 0.020 to 0.400 mol of a polymerization initiator with respect to 1.0 mol of a dithioester compound, and in the presence of the resulting acrylic prepolymer, This is a method for producing an acrylic emulsion in which a monomer is emulsion-polymerized.

  The present invention is suitable for various materials such as polyolefins typified by polypropylene, which is a nonpolar plastic regarded as hardly adhesive, and polyamides typified by nylon having polarity and widely used as engineering plastics. Provided is a method for producing an acrylic emulsion having properties, compatibility and adhesion.

  The acrylic emulsion produced in the present invention is useful as a compatibilizing polymer of different polymer materials such as polycarbonate resin and ABS resin. In addition, the acrylic emulsion produced in the present invention has higher strength by improving dispersion stability, compatibility, and adhesion between functional reinforcing materials such as glass fiber, carbon fiber, aramid fiber, and titanium whisker and matrix resin. Composite materials can be manufactured.

  In the present invention, an acrylic monomer is bulk-polymerized using 0.020 to 0.400 mol of a polymerization initiator with respect to 1.0 mol of a dithioester compound, and in the presence of the resulting acrylic prepolymer, This is a method for producing an acrylic emulsion in which a monomer is emulsion-polymerized.

  In the method for producing an acrylic emulsion of the present invention, 2-propyl-dithioacetate, 2-t-butyl-dithioacetate, 2-phenyl-dithioacetate, 2-phenyl-dithiobenzoate, 1-phenylethyl- Examples include phenyl dithioacetate, 2-phenylpropyl-phenyl dithioacetate, benzyl dithiobenzoate, 1-phenylethyl-pentafluorophenyl dithioacetate, 2-phenylpropyl-pentafluorophenyl dithioacetate, pentafluorobenzyl dithiobenzoate, etc. The In the method for producing an acrylic emulsion of the present invention, the dithioester compound may be used alone or in a mixture of two or more.

  In the method for producing an acrylic emulsion of the present invention, the dithioester compound is represented by the following structural formula.

(Where Z is a phenyl group, a benzyl group, a chemical structure represented by the following structural formula

(Pentafluorobenzyl group)

(Pentafluorophenyl group)
Represents one of the following:
R ₁ represents a hydrogen atom, a nitrile group, or an alkyl group having 1 to 4 carbon atoms, R ₂ represents a hydrogen atom, a nitrile group, or an alkyl group having 1 to 4 carbon atoms, R ₃ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a hydroxyethyl group, a hydroxypropyl group, a carboxylethyl group, a carboxypropyl group, an aminoethyl group, an aminopropyl group, a phenyl group, or a substituted group. A phenyl group having a group (however, the substituent is a nitrile group, an alkyl group having 1 to 4 carbon atoms, a hydroxyl group, a hydroxyethyl group, a hydroxypropyl group, a carboxyl group, a carboxyethyl group, a carboxypropyl group, a sulfonyl group) Group and salt, amino group, aminoethyl group, aminopropyl group.)
Represents. )
A dithioester compound is desirable.

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

(Where Z is a phenyl group, a benzyl group, a chemical structure represented by the following structural formula

(Pentafluorobenzyl group)

(Pentafluorophenyl group)
Represents one of the following:
R ₁ represents a hydrogen atom, a nitrile group, or an alkyl group having 1 to 4 carbon atoms, R ₂ represents a hydrogen atom, a nitrile group, or an alkyl group having 1 to 4 carbon atoms, R ₃ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a hydroxyethyl group, a hydroxypropyl group, a carboxylethyl group, a carboxypropyl group, an aminoethyl group, an aminopropyl group, a phenyl group, or a substituted group. A phenyl group having a group (however, the substituent is a nitrile group, an alkyl group having 1 to 4 carbon atoms, a hydroxyl group, a hydroxyethyl group, a hydroxypropyl group, a carboxyl group, a carboxyethyl group, a carboxypropyl group, a sulfonyl group) Group) and a salt, an amino group, an aminoethyl group, and an aminopropyl group. )
Represents. )
When R ₁ is a hydrogen atom, R ₂ is a methyl group, R ₃ is a phenyl group, and Z is a benzyl group, the dithioester compound is 1-phenylethyl-phenyldithioacetate, R ₁ is a methyl group, and R ₂ is a methyl group When R ₃ is a phenyl group and Z is a benzyl group, 2-phenylpropyl-phenyldithioacetate, R ₁ is a hydrogen atom, R ₂ is a methyl group, R ₃ is a phenyl group, and Z is a pentafluorobenzyl group 1-phenylethyl-pentafluorophenyl dithioacetate, when R ₁ is a methyl group, R ₂ is a methyl group, R ₃ is a phenyl group, and Z is a pentafluorobenzyl group, 2-phenylpropyl-pentafluorophenyl dithioacetate, R ₂ is a hydrogen atom, _{R 2} is a hydrogen atom, when _{R 3} is a phenyl group, Z is a pentafluorophenyl group, dithiobenzoic Pentafluorobenzyl, _{R 1} is a hydrogen atom, _{R 2} is a methyl group, _{R 3} is p- aminopropyl phenyl group, when Z is a benzyl group, 1-p- aminopropyl phenylethyl - phenyl dithioacetate, _{R 1} is cyano Group, R ₂ is a methyl group, R ₃ is a hydroxypropyl group, and Z is a phenyl group, 2-cyano-5-hydroxypentyl-phenyldithioacetate, R ₁ is a cyano group, R ₂ is a methyl group, and R ₃ is When carboxyethyl group and Z is phenyl group, 2-cyano-4-carboxybutyl-phenyl dithioacetate and the like are exemplified. In the method for producing an acrylic emulsion of the present invention, these dithioester compounds may be used alone or in a mixture of two or more.

  In the acrylic emulsion production method of the present invention, among these dithioester compounds, 1-phenylethyl-pentafluorophenyl dithioacetate has a high polymerization rate and high production efficiency, and the produced acrylic prepolymer has low odor. Dithioester compounds having a pentafluorophenyl group or a pentafluorobenzyl group in a molecule such as 2-phenylpropyl-pentafluorophenyl dithioacetate and pentafluorobenzyl dithiobenzoate are recommended.

  In the method for producing an acrylic emulsion of the present invention, when these dithioester compounds are used, there is little odor peculiar to the dithioester compounds, and there is a tendency that coloring of the polymer is alleviated. In addition, these dithioester compounds preferably show a tendency that a polymer having a small molecular weight distribution can be efficiently produced as a RAFT agent.

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

  In the method for producing an acrylic emulsion 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 recommended. Thus, safety during the production of the acrylic prepolymer is ensured, the radical polymerizability as the prepolymer is improved, and an acrylic prepolymer having a controlled narrow molecular weight distribution tends to be produced.

  In the method for producing an acrylic emulsion of the present invention, the polymerization initiator is 0.020 to 0.400 mol, preferably 0.040 to 0.350 mol, more preferably 0, to 1.0 mol of the dithioester compound. It is desirable to use 0.020 to 0.300 mol. In the method for producing an acrylic acrylic emulsion of the present invention, when the amount of the polymerization initiator used in the production of the acrylic prepolymer is less than 0.020 mol, the polymerization rate is slow and the polymerization rate of the acrylic prepolymer is practically sufficient. It cannot be raised to a certain level. When the amount of the polymerization initiator used exceeds 0.400 mol, heat generated when the acrylic prepolymer is produced by bulk polymerization is intense, and stirring and heat removal become incomplete, which is not preferable for safety and disaster prevention.

  Here, in the method for producing an acrylic emulsion of the present invention, the polymerization rate at a practical level of the acrylic prepolymer is preferably 80% or more, more preferably 85% or more, and further preferably 88% or more. desirable. In the method for producing an acrylic emulsion of the present invention, if the polymerization rate of the acrylic prepolymer is 80% or more, the acrylic prepolymer is used, and when the molecular weight is further increased by radical polymerization, or a block copolymer is produced, There is a tendency that a block copolymer capable of increasing the molecular weight more efficiently and exhibiting more functions can be produced, which is desirable.

  In the method for producing an acrylic emulsion of the present invention, in order to more safely control the polymerization temperature, the polymerization initiator used for producing the acrylic prepolymer is based on 100 parts by weight of the acrylic monomer used for the acrylic prepolymer. Preferably, it is 0.02 to 2 parts by weight, more preferably 0.2 to 2 parts by weight, and still more preferably 0.2 to 1.5 parts by weight. In the method for producing an acrylic emulsion of the present invention, when the amount of the polymerization initiator used for producing the acrylic prepolymer is 0.02 to 2 parts by weight, an abnormal polymerization reaction or rapid heat generation tends to hardly occur. .

  In the method for producing an acrylic emulsion of the present invention, the acrylic prepolymer is produced by bulk polymerization. In the method for producing an acrylic emulsion according to the present invention, bulk polymerization refers to 0.020 to 0.400 mol of a polymerization initiator and acrylic monomer in an acrylic prepolymer production vessel and 1.0 mol of a dithioester compound. In this method, a polymer is charged and radical polymerization is performed by heating to a predetermined polymerization temperature. In the method for producing an acrylic emulsion of the present invention, a diluent medium such as an organic solvent and water is preferably not included during the production of the acrylic prepolymer.

  In the case of general bulk polymerization, due to the large polymerization heat that occurs suddenly and the viscosity that rapidly increases as the polymerization rate increases, the stirring power becomes insufficient, and the polymerization temperature becomes uncontrollable, resulting in runaway reaction. There are many cases. There are dangers that can lead to serious disasters such as explosions and explosions, and no matter how much you modify the equipment, there are industrial limits.

  Further, due to insufficient stirring and heat removal, local heating is likely to occur, and quality deterioration such as polymer burning and higher degree of polymerization is likely to occur.

  In the method for producing an acrylic emulsion of the present invention, the acrylic prepolymer is produced by using 0.020 to 0.400 mol of a polymerization initiator with respect to 1.0 mol of a dithioester compound, and bulk polymerization is carried out. In addition, concerns such as stirring at the time of acrylic prepolymer production, runaway reaction due to insufficient heat removal, and deterioration of quality due to local heating are eliminated, and the acrylic prepolymer can be produced safely and stably. In addition, the polymerization rate of the acrylic prepolymer can be increased to a practically necessary and sufficient level within an industrially appropriate production time.

  In the method for producing an acrylic emulsion of the present invention, when producing an acrylic prepolymer, the gas phase oxygen concentration of the production vessel substituted with inert gas is preferably 0.0 vol% ≦ gas phase oxygen concentration ≦ 8. 0 vol%, more preferably 0.02 vol% ≦ gas phase oxygen concentration ≦ 8.0 vol%, and even more preferably 0.02 vol% ≦ gas phase oxygen concentration ≦ 6.0 vol%. Is desirable. In the method for producing an acrylic emulsion of the present invention, if the gas phase oxygen concentration during the production of the acrylic prepolymer is 0.0 vol% ≦ gas phase oxygen concentration ≦ 8.0 vol%, the acrylic monomer is contained in the gas phase portion. An acrylic prepolymer can be produced safely and efficiently without causing a polymerization reaction.

  In the method for producing an acrylic emulsion of the present invention, the oxygen concentration in the acrylic prepolymer 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 emulsion 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.

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

  In the method for producing an acrylic emulsion of the present invention, the polymerization temperature of the acrylic prepolymer is preferably 50 to 100 ° C, more preferably 65 to 95 ° C, and further preferably 70 to 90 ° C. In the method for producing an acrylic emulsion of the present invention, when the polymerization temperature during the production of the acrylic prepolymer is 50 to 100 ° C., there is a tendency that stirring and heat removal can be carried out quantitatively, and concerns on disaster prevention are wiped out. There is a tendency to be able to produce acrylic prepolymers safely and securely. In addition, even when relatively low boiling point acrylic monomers such as methyl methacrylate and ethyl acrylate are copolymerized, it is safer to produce a large amount of monomer vapor during production. There is a tendency to become possible.

  In the method for producing an acrylic emulsion of the present invention, the production of the acrylic prepolymer is performed at a predetermined polymerization temperature, preferably 60 to 300 minutes, more preferably 90 to 300 minutes, and even more preferably 90 to 180 minutes, It is recommended to perform bulk polymerization. In the method for producing an acrylic emulsion of the present invention, the radical polymerization reaction proceeds quantitatively and faster when stirring time is increased when the temperature rise time to the predetermined polymerization temperature is preferably 60 to 300 minutes during the production of the acrylic prepolymer. There is a tendency that heat can be made easier and manufacturing operations can be carried out more safely. In addition, by increasing the polymerization rate, the production time can be shortened, the molecular weight distribution of the acrylic prepolymer becomes smaller, and the functional expression as an acrylic prepolymer is expected more.

  In the method for producing an acrylic emulsion of the present invention, the acrylic monomer used in the acrylic prepolymer is preferably methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, tertiary butyl acrylate, Cyclohexyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, isobornyl acrylate, trifluoroethyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tertiary butyl methacrylate, methacrylic acid (Meth) acrylic acid (fluoro) al, such as cyclohexyl, 2-ethylhexyl methacrylate, lauryl methacrylate, benzyl methacrylate, isobornyl methacrylate, trifluoroethyl methacrylate Ester monomers, carboxyl group-containing acrylic monomers such as acrylic acid and methacrylic acid, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate Hydroxyl group-containing acrylic monomers such as 4-hydroxybutyl methacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monoacrylate, polypropylene glycol monomethacrylate, polytetramethylene glycol monoacrylate, polytetramethylene glycol monomethacrylate, N, N-dimethylaminoethyl acrylate, N, N-diethylaminoethyl acrylate, N, N-di Tertiary amino group-containing acrylic monomers such as tilaminoethyl methacrylate and N, N-diethylaminoethyl methacrylate, 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine, 4-methacryloyloxy-1,2, Hindered amino group-containing acrylic monomers such as 2,6,6-pentamethylpiperidine, acrylamide, N, N-dimethylacrylamide, N-isopropylacrylamide, hydroxymethylacrylamide, hydroxyethylacrylamide, N, N-dimethylaminopropyl Acrylamide, 2-acrylamido-2-methyl-propanesulfonic acid, diacetone acrylamide, N-methoxymethyl acrylamide, N-ethoxymethyl acrylamide, N-butoxymethyl acrylamide, 4- Amide group-containing acrylic monomers such as methacrylamidoethylethylene urea, urea group-containing acrylic monomers such as N- (2-methacryloyloxyethyl) ethylene urea, glycidyl acrylate, methyl glycidyl acrylate, glycidyl methacrylate, methacryl Epoxy group-containing acrylic monomers such as methyl glycidyl acid, o, p, m-vinylbenzyl glycidyl ether, dicyclopentenyloxyethyl acrylate, dicyclopentenyloxy acrylate, dicyclopentenyloxyethyl methacrylate, dicyclopentenyloxy methacrylate, Dicyclopentadiene derivative acrylic monomers such as dicyclopentanyl methacrylate and dicyclopentanyl acrylate, 3-methacryloyloxypropyltrimethoxysilane Emissions, such as 3-methacryloyloxy alkoxysilane group-containing acrylic monomers such as trimethoxy silane, and the like. In the method for producing an acrylic emulsion of the present invention, these acrylic monomers may be used alone or in a mixture of two or more.

  In the acrylic emulsion production method of the present invention, among these acrylic monomers, a methacrylate monomer that can shorten the production time and can easily adjust the molecular weight is recommended.

  In the method for producing an acrylic emulsion of the present invention, the acrylic monomer used in the acrylic prepolymer is represented by the following structural formula.

(Here, R ₄ represents a hydrogen atom or a methyl group.)
It is recommended to include dicyclopentenyloxyethyl acrylate and / or dicyclopentenyloxyethyl methacrylate.

  In the acrylic emulsion production method of the present invention, among the acrylic monomers, a methacrylate monomer is desirable, and dicyclopentenyloxyethyl methacrylate is desirable because it shortens production time, copolymerization, and molecular weight distribution. . In the method for producing an acrylic emulsion of the present invention, dicyclopentenyloxyethyl methacrylate is commercially available, such as “QM-657” (product of Rohm and Haas) and “FANCRYL FA-512M” (product of Hitachi Chemical Co., Ltd.). You can choose any of the listed items.

  In the method for producing an acrylic emulsion of the present invention, when dicyclopentenyloxyethyl acrylate and / or dicyclopentenyloxyethyl methacrylate is used for the acrylic prepolymer, it is typified by polypropylene, which is a nonpolar plastic that is hardly adhered. There is a tendency to have good wettability, compatibility, and adhesiveness to various materials such as polyolefin, which has polarity, and polyamide which is widely used as an engineering plastic and is represented by nylon.

  In the method for producing an acrylic emulsion of the present invention, dicyclopentenyloxyethyl acrylate and / or dicyclopentenyloxyethyl methacrylate is preferably 20%, with the total amount of acrylic monomers used in the acrylic prepolymer being 100% by weight. It is desirable to use -100% by weight, more preferably 25-98% by weight, still more preferably 25-95% by weight. In the method for producing an acrylic emulsion of the present invention, when the amount of dicyclopentenyloxyethyl acrylate and / or dicyclopentenyloxyethyl methacrylate used in the acrylic prepolymer is 20 to 100% by weight, it is considered to be difficult to adhere. Tendency to have good wettability, compatibility, and adhesion to various materials such as polyolefin, typified by polypropylene, which is a non-polar plastic, and polyamide, typified by nylon, which has polarity and is widely used as engineering plastic. Is seen.

  In the method for producing an acrylic emulsion of the present invention, among the acrylic monomers, the alkyl methacrylate ester monomer is represented by the following structural formula.

The use of isobornyl methacrylate is recommended.

  In the method for producing an acrylic emulsion of the present invention, there is a tendency that the wettability and the compatibility are further improved by using isobornyl methacrylate having a bulky molecular structure. In particular, there is a tendency to improve the wettability, compatibility and adhesion with polyolefins typified by polypropylene and polyethylene.

  In the method for producing an acrylic emulsion of the present invention, isobornyl methacrylate is preferably 2 to 60% by weight, more preferably 3 to 50%, with the total amount of acrylic monomers used in the acrylic prepolymer being 100% by weight. It is desirable to use it by weight%, more preferably 3 to 30% by weight. In the method for producing an acrylic emulsion of the present invention, when the amount of isobornyl methacrylate used is 2 to 60% by weight, there is a tendency that the wettability, compatibility and adhesion are further improved.

  In the method for producing an acrylic emulsion of the present invention, as the acrylic monomer having a functional group used in the acrylic prepolymer, methacrylic acid (carboxyl group), 2-hydroxyethyl methacrylate (hydroxyl group), glycidyl methacrylate (epoxy) Group), 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine (amino group), N- (2-methacrylolyloxyethyl) ethylene urea (urea group) and the like are desirable. When these acrylic monomers are used, there is a tendency that compatibility, wettability and adhesion are improved. In addition, the acrylic prepolymer tends to exhibit crosslinkability, resulting in an acrylic emulsion with improved chemical properties and mechanical strength.

  In the method for producing an acrylic emulsion of the present invention, methacrylic acid is preferably 0.5 to 20% by weight, more preferably 1.0%, with the total amount of acrylic monomers used in the acrylic prepolymer as 100% by weight. It is desirable to use -15% by weight, more preferably 1.2-15% by weight. In the method for producing an acrylic emulsion of the present invention, when the amount of methacrylic acid used is 0.5 to 20% by weight, the cohesive force of the acrylic prepolymer is improved and the adhesiveness tends to be improved.

  In the method for producing an acrylic emulsion of the present invention, 2-hydroxyethyl methacrylate is preferably 3 to 30% by weight, more preferably 3%, based on 100% by weight of the total amount of acrylic monomers used in the acrylic prepolymer. It is desirable to use -25% by weight, more preferably 5-20% by weight. In the manufacturing method of the acrylic emulsion of this invention, when the usage-amount of 2-hydroxyethyl methacrylate is 3-30 weight%, the tendency for compatibility and wettability to improve, and adhesiveness improves.

  In the method for producing an acrylic emulsion of the present invention, glycidyl methacrylate is preferably 3 to 30% by weight, more preferably 3 to 25% by weight, with the total amount of acrylic monomers used in the acrylic prepolymer being 100% by weight. %, More preferably 5 to 20% by weight. In the method for producing an acrylic emulsion of the present invention, when the amount of methacrylic acid used is 3 to 30% by weight, compatibility and wettability are improved, and crosslinkability is developed in the acrylic prepolymer, thereby improving adhesiveness. There is a trend.

  In the method for producing an acrylic emulsion of the present invention, 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine is preferably 100% by weight as the total amount of acrylic monomers used in the acrylic prepolymer. It is desirable to use 0.5 to 20% by weight, more preferably 1.0 to 15% by weight, and still more preferably 1.2 to 15% by weight. In the method for producing an acrylic emulsion of the present invention, when the amount of 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine used is 0.5 to 20% by weight, compatibility and wettability are improved, and acrylic There is a tendency to improve the adhesion of the emulsion. Moreover, the tendency which becomes excellent in weather resistance is seen.

  In the method for producing an acrylic emulsion of the present invention, N- (2-methacryloyloxyethyl) ethylene urea is preferably 0.5 to 20 with the total amount of acrylic monomers used in the acrylic prepolymer as 100% by weight. It is desirable to use by weight%, more preferably 1.0 to 15% by weight, and still more preferably 1.2 to 15% by weight. In the method for producing an acrylic emulsion of the present invention, when the amount of N- (2-methacryloyloxyethyl) ethylene urea used is 0.5 to 20% by weight, the cohesive force of the acrylic prepolymer is improved and the adhesiveness is improved. The tendency to do is seen. In addition, the compatibility and wettability of acrylic emulsions have been dramatically improved, and coupled with the development of crosslinkability, polyolefins such as polypropylene and polyethylene, polar polymers such as nylon, metals such as aluminum alloys and iron can be selected. There is a tendency to develop excellent compatibility, wettability and adhesiveness.

  The acrylic emulsion of the present invention is produced by emulsion polymerization of an acrylic monomer in the presence of an acrylic prepolymer. In the method for producing an acrylic emulsion of the present invention, the acrylic emulsion may be produced by any emulsion polymerization method such as a monomer dropping method, an emulsion dropping method, or a seed emulsion polymerization method.

  In emulsion polymerization, an anionic emulsifier such as dodecylbenzenesulfonic acid or a nonionic emulsifier such as polyoxyethylene alkylphenyl ether is usually used to stably emulsify and disperse the acrylic monomer in water, or a positive An ionic emulsifier is used, and a water-soluble persulfate such as ammonium persulfate or potassium persulfate is used as a polymerization initiator, and the polymerization is carried out at a polymerization temperature of 30 to 100 ° C.

  In the method for producing an acrylic emulsion of the present invention, emulsion polymerization is carried out using a water-soluble organic azo polymerization initiator as a polymerization initiator and an anionic reactive emulsifier having an allyl group in the molecule as an emulsifier. Is desirable.

  In the method for producing an acrylic emulsion of the present invention, a water-soluble organic azo polymerization initiator is desirable as a polymerization initiator used for emulsion polymerization. In the method for producing an acrylic emulsion of the present invention, when a water-soluble organic azo polymerization initiator is used for emulsion polymerization, the pH of the acrylic emulsion produced during emulsion polymerization and preferably produced is preferably 4.0 to 10.0. Thus, during the emulsion polymerization and storage of the acrylic emulsion, a functional group useful as a functional polymer such as an epoxy group or an alkoxysilane group, and a highly active functional group is not lost by the reaction. It can be used for a long time as a highly active and highly functional polymer.

  In the method for producing an acrylic emulsion of the present invention, the pH / 25 ° C. of the acrylic emulsion produced during emulsion polymerization is preferably 4.0 to 10.0, more preferably 4.5 to 9.8, still more preferably. It is desirable that it is 4.5-9.5. In the method for producing an acrylic emulsion of the present invention, during emulsion polymerization and when the pH / 25 ° C. of the produced acrylic emulsion is preferably 4.0 to 10.0, during emulsion polymerization and during storage of the produced acrylic emulsion. There is a tendency that a functional group that is active and effective in imparting a function does not disappear, and is stably maintained for a long time until it is applied as a compatibilizing polymer, an adhesive, or the like.

  In the method for producing an acrylic emulsion of the present invention, the water-soluble organic azo polymerization initiator is represented by the following structural formula.

A water-soluble organic azo polymerization initiator having an imidazoline group in the molecule such as 2,2-azobis [2- (2-imidazolin-2-yl) propane], which is represented by the following structural formula

A water-soluble organic azo polymerization initiator having amidyl in the molecule, such as 2,2-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], represented by the following structural formula

In the molecule such as 2,2-azobis [2-methyl-N- (2-carboxyethyl) -2-methylpropionamidine] hydrate, amide group -C (O) NH-, amidine group -C (N) NH And water-soluble organic azo polymerization initiators having-. In the method for producing an acrylic emulsion of the present invention, these water-soluble organic azo polymerization initiators may be used alone or in a mixture of two or more.

  In the method for producing an acrylic emulsion of the present invention, in order to adjust the pH / 25 ° C. of the acrylic emulsion to preferably 4.0 to 10.0, it is preferably represented by the following structural formula.

2,2-azobis [2- (2-imidazolin-2-yl) propane] is preferred.

  In the method for producing an acrylic emulsion of the present invention, the water-soluble organic azo polymerization initiator is preferably 0.05 to 5.0 parts by weight, more preferably 100 to parts by weight, and more preferably 0.05 to 5.0 parts by weight. It is desirable to use 0.1 to 3.0 parts by weight, more preferably 0.2 to 2.5 parts by weight. In the method for producing an acrylic emulsion of the present invention, when the amount of the water-soluble organic azo polymerization initiator used is 0.05 to 5.0 parts by weight, the polymerization rate is appropriately adjusted to suppress heat generation during production, There is a tendency that the generation of aggregates is small and the amount of unreacted monomers decreases.

  In the method for producing an acrylic emulsion of the present invention, the anionic reactive emulsifier having an allyl group in the molecule can be arbitrarily selected from those on the market. Anionic reactive emulsifiers having an allyl group in the marketed molecules are “Latemul PD-104” (polyoxyalkylene alkenyl ether ammonium sulfate) (Kao product), “Aqualon KH-1025” (Daiichi Kogyo Seiyaku) Product), "Adekariasorb SR-1025" (25% aqueous solution of ammonium salt of (α-sulfo-ω-((1-alkoxymethyl-2-propenyloxy) ethoxy-polyoxy-1,2-ethanediyl)) (Asahi In the method for producing an acrylic emulsion of the present invention, these anionic reactive emulsifiers having an allyl group in the molecule may be used alone or in a mixture of two or more. May be used.

  In the method for producing an acrylic emulsion of the present invention, when an anionic reactive emulsifier having an allyl group in the molecule is used as an emulsifier for emulsion polymerization, an acrylic emulsion having good emulsion stability and few residual monomers can be produced. Further, in the method for producing an acrylic emulsion of the present invention, the chemical properties and mechanical properties of the produced acrylic emulsion are improved and improved.

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

(Here, R ₅ represents an alkyl group having 8 to 24 carbon atoms.)
An anionic reactive emulsifier having an allyl group in the molecule is desirable.

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

(Here, R ₅ represents an alkyl group having 8 to 24 carbon atoms.)
Examples of the anionic reactive emulsifier having an allyl group in the molecule include “Adeka Resorb SR-1025” (product of Asahi Denka Kogyo).

In the method for producing an acrylic emulsion of the present invention, (α-sulfo-ω-((1-undecanoxymethyl-2-propenyloxy) ethoxy-polyoxy-1,2 wherein R ₅ is —C ₁₁ H ₂₃ is more preferred. -Ethanediyl) ammonium salt is preferred.

  In the method for producing an acrylic emulsion of the present invention, when an anionic reactive emulsifier having an allyl group in these molecules is used, an acrylic emulsion having very good emulsification stability and a small amount of residual monomer is produced. . In addition, it is easy to control the particle size of the acrylic emulsion, and an acrylic emulsion with improved functionality can be produced.

  In the method for producing an acrylic emulsion of the present invention, the anionic reactive emulsifier having an allyl group in the molecule is preferably set to 1 to 100% by weight as the total amount of the acrylic prepolymer and the acrylic monomer to be emulsion-polymerized. It is desirable to use 20% by weight, more preferably 1.5 to 20% by weight, and still more preferably 1.8 to 16% by weight. In the method for producing an acrylic emulsion of the present invention, when the amount of the anionic reactive emulsifier having an allyl group in the molecule is 1 to 20% by weight, the emulsion stability is good and the emulsion polymerization proceeds smoothly, There is a tendency that an acrylic emulsion with less aggregates can be produced.

  In the method for producing an acrylic emulsion according to the present invention, preferably, an acrylic prepolymer is dissolved in an acrylic monomer to be emulsion-polymerized, and then an anionic reactive emulsifier having an allyl group in the molecule is added thereto to perform ion exchange. After preparing a pre-emulsion emulsified by adding water, this is added to a polymerization system containing ion-exchanged water and a water-soluble organic azo polymerization initiator, and emulsion polymerization is preferably performed by an emulsion method in which emulsion polymerization is performed. There is a tendency that an acrylic emulsion having a small particle size and a uniform particle size is produced.

  In the method for producing an acrylic emulsion of the present invention, preferably in the presence of an acrylic prepolymer,

The pH / 25 ° C. when an acrylic monomer containing methacrylic acid is emulsion-polymerized is preferably 4.0 to 7.0.

  The pH / 25 ° C. when an acrylic monomer containing methacrylic acid is emulsion-polymerized is more preferably 4.2 to 6.5, and still more preferably 4.3 to 6.3. In the acrylic emulsion of the present invention, when methacrylic acid is used and the pH / 25 ° C. when the acrylic monomer containing methacrylic acid is emulsion-polymerized is 4.0 to 7.0, the carboxyl group is on the surface of the acrylic emulsion particles. Tend to be oriented in a large amount, and there is a tendency to improve compatibility, wettability and adhesion.

  In the acrylic emulsion of the present invention, methacrylic acid is preferably 1.0 to 10% by weight, more preferably 1.5 to 8.0% by weight, with the total amount of acrylic monomers to be emulsion polymerized being 100% by weight. %, More preferably 3.0 to 8.0% by weight. In the acrylic emulsion of the present invention, when the amount of methacrylic acid used is 1.0 to 10% by weight, the cohesive force of the acrylic polymer increases, and the tendency to improve and improve the adhesiveness is observed.

In the acrylic emulsion of the present invention, preferably in the presence of an acrylic prepolymer,
Of the following structural formula

The pH / 25 ° C. when an acrylic monomer containing glycidyl methacrylate is subjected to emulsion polymerization is preferably 6.0 to 8.0.

  The pH / 25 ° C. when an acrylic monomer containing glycidyl methacrylate is subjected to emulsion polymerization is more preferably 6.3 to 8.0, and still more preferably 6.5 to 7.8. In the method for producing an acrylic emulsion of the present invention, if the acrylic monomer containing glycidyl methacrylate is emulsion-polymerized and the pH / 25 ° C. is 6.0 to 8.0, the epoxy group disappears during storage of the acrylic emulsion. Thus, there is a tendency for the function to continue without losing reactivity and action as an epoxy group. In addition, there is a tendency for epoxy groups to be oriented more on the surface of acrylic emulsion particles, and compatibility with organic polymers such as aluminum alloys, iron, titanium alloys, and other organic polymer materials such as polypropylene, nylon, ABS, and epoxy resin, and wettability. There is a tendency to improve the adhesion.

  In the acrylic emulsion of the present invention, glycidyl methacrylate is preferably 3.0 to 50% by weight, more preferably 5 to 35% by weight, more preferably 100 to 50% by weight of the total amount of acrylic monomers to be emulsion polymerized. Preferably, 5 to 30% by weight is used. In the acrylic emulsion of the present invention, when the amount of glycidyl methacrylate used is 3 to 50% by weight, the compatibility, wettability and adhesion of various materials such as polyolefin, nylon, aluminum alloy and iron of the acrylic emulsion are improved and improved. There is a trend. Moreover, the tendency for the crosslinkability of an acrylic emulsion to improve is seen, and the tendency for a tough compatibilizing polymer, an adhesive agent, etc. to be manufactured is seen.

  In the method for producing an acrylic emulsion of the present invention, preferably in the presence of an acrylic prepolymer,

It is desirable that pH / 25 ° C. when an acrylic monomer containing vinylbenzyl glycidyl ether is subjected to emulsion polymerization is preferably 6.0 to 8.0. In the method for producing an acrylic emulsion of the present invention, the vinyl benzyl glycidyl ether is any one of ortho (o-) vinyl benzyl glycidyl ether, meta (m-) vinyl benzyl glycidyl ether, and para (p-) vinyl benzyl glycidyl ether. Benzyl glycidyl ether may be used alone or in a mixture of two or more.

  The pH / 25 ° C. when an acrylic monomer containing vinylbenzyl glycidyl ether is subjected to emulsion polymerization is more preferably 6.3 to 8.0, and further preferably 6.5 to 7.8. In the method for producing an acrylic emulsion of the present invention, if the acrylic monomer containing vinylbenzyl glycidyl ether is emulsion-polymerized and the pH / 25 ° C. is 6.0 to 8.0, the epoxy group is contained during storage of the acrylic emulsion. There is a tendency for the function to continue without disappearing and losing reactivity and action as an epoxy group. At the same time, the reactivity of the epoxy group is better than that of glycidyl methacrylate, which is a glycidyl ester monomer, and a tendency to improve crosslinkability and adhesiveness is observed. In addition, there is a tendency for epoxy groups to be oriented more on the surface of acrylic emulsion particles, and compatibility with organic polymers such as aluminum alloys, iron, titanium alloys, and other organic polymer materials such as polypropylene, nylon, ABS, and epoxy resin, and wettability. There is a tendency to improve the adhesion.

  In the acrylic emulsion of the present invention, the vinylbenzyl glycidyl ether is preferably 3.0 to 50% by weight, more preferably 5 to 35% by weight, even more preferably 100% by weight of the total amount of acrylic monomers to be emulsion polymerized. Is preferably used in an amount of 5 to 30% by weight. In the acrylic emulsion of the present invention, when the amount of vinylbenzyl glycidyl ether used is 3 to 50% by weight, the compatibility, wettability and adhesion of various materials such as polyolefin, nylon, aluminum alloy, and iron are improved and improved. The tendency to do is seen. Moreover, the tendency for the crosslinkability of an acrylic emulsion to improve is seen, and the tendency for a tough compatibilizing polymer, an adhesive agent, etc. to be manufactured is seen.

In the method for producing an acrylic emulsion of the present invention, the following structural formula is obtained in the presence of an acrylic prepolymer.

PH / 25 ° C. when an acrylic monomer containing 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine is emulsion-polymerized is preferably an acrylic emulsion of 8.0 to 10.0. Is desirable.

  In the method for producing an acrylic emulsion of the present invention, 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine is produced by “FANCYL FA-712HM” (product of Hitachi Chemical), “Adeka Stub LA-87” (Asahi). It can be arbitrarily selected from those on the market, such as products from Denka Kogyo).

  The pH / 25 ° C. when an acrylic monomer containing 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine is emulsion-polymerized is more preferably 8.5 to 10.0, still more preferably It is desirable that it is 8.5-9.8.

  In the acrylic emulsion of the present invention, when the acrylic monomer containing 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine is emulsion-polymerized and pH / 25 ° C. is 8.0 to 10.0. , Amino groups exist stably during storage of acrylic emulsion, and amino groups tend to be oriented on the surface of acrylic emulsion particles. Metal such as aluminum alloy, iron, titanium alloy, polypropylene, nylon, ABS, epoxy resin There is a tendency to improve compatibility, wettability, and adhesion to organic polymer materials such as.

  In the acrylic emulsion of the present invention, 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine is 100% by weight, preferably 1 to 50% by weight, based on the total amount of acrylic monomers to be emulsion-polymerized. It is preferable to use 3 to 35% by weight, more preferably 5 to 30% by weight. In the acrylic emulsion of the present invention, when 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine is used in an amount of 1 to 50% by weight, various functional materials such as carbon fiber, glass fiber and titanium whisker of the acrylic emulsion There is a tendency to improve and improve the compatibility, wettability, and adhesiveness. In addition, there is a tendency that the crosslinkability and weather resistance of the acrylic emulsion are improved, and there is a tendency that a composite such as a fiber reinforced plastic having improved and improved mechanical strength is produced.

In the acrylic emulsion of the present invention, in the presence of an acrylic prepolymer,
Of the following structural formula

The pH / 25 ° C. when an acrylic monomer containing N- (2-methacryloyloxyethyl) ethylene urea is emulsion-polymerized is preferably 7.0 to 10.0.

  In the method for producing an acrylic emulsion of the present invention, N- (2-methacryloyloxyethyl) ethylene urea has been marketed, such as “PLEX 6852-0” and “PLEX 6844-0” (above, products of Evonik Degussa Japan). You can choose from what you have.

In the method for producing an acrylic emulsion of the present invention, the pH / 25 ° C. when an acrylic monomer containing N- (2-methacryloyloxyethyl) ethylene urea is emulsion-polymerized is more preferably 7.2 to 10.0. More preferably, it is 7.3 to 9.8. In the acrylic emulsion of the present invention, N- (2-methacryloyloxyethyl) ethylene urea is used, and if the acrylic emulsion has a pH / 25 ° C. of 7.0 to 10.0, the urea group is stable during storage of the acrylic emulsion. In addition, there is a tendency that urea groups tend to be oriented on the surface of acrylic emulsion particles, and compatibility with metals such as aluminum alloy, iron, and titanium alloy, and organic polymer materials such as polypropylene, nylon, ABS, and epoxy resin. In the method for producing an acrylic emulsion of the present invention, N- (2-methacryloyloxyethyl) ethylene urea is 100% by weight of the total amount of acrylic monomers to be emulsion polymerized. Preferably, 1 to 50% by weight, more preferably 3 to 35% by weight, and even more preferably It is desirable to use 5 to 30% by weight. In the method for producing an acrylic emulsion of the present invention, when the amount of N- (2-methacryloyloxyethyl) ethylene urea used is 1 to 50% by weight, the phase of the acrylic emulsion for various functional materials such as carbon fiber, glass fiber, and titanium whisker is used. There is a tendency for solubility, wettability, and adhesion to improve and improve. In addition, there is a tendency that the crosslinkability and weather resistance of the acrylic emulsion are improved, and there is a tendency that a composite such as a fiber reinforced plastic having improved and improved mechanical strength is produced.

  In the acrylic emulsion of the present invention, an acrylic monomer that undergoes emulsion polymerization is represented by the following structural formula.

(Here, R ₄ represents a hydrogen atom or a methyl group.)
It is desirable to include dicyclopentenyloxyethyl acrylate and / or dicyclopentenyloxyethyl methacrylate.

  In the method for producing an acrylic emulsion of the present invention, preferably, dicyclopentenyloxyethyl acrylate and / or dicyclopentenyloxyethyl methacrylate is used for both the acrylic prepolymer and the acrylic monomer to be emulsion-polymerized. Appropriate incompatibility and compatibility are formed between the acrylic prepolymer and the emulsion-polymerized acrylic polymer, and the cohesive strength of the polymer obtained by emulsion polymerization of the acrylic monomer in the presence of the acrylic prepolymer improves and is tough. Tend to be produced. In addition, the rheology of the polymer tends to be preferably controlled, and when used as a compatibilizing polymer, the strength of the matrix resin tends to be further improved.

  In the acrylic emulsion of the present invention, dicyclopentenyloxyethyl acrylate and / or dicyclopentenyloxyethyl methacrylate is preferably 20 to 100% by weight, with the total amount of acrylic monomers used for emulsion polymerization being 100% by weight. %, More preferably 25 to 98% by weight, still more preferably 25 to 95% by weight. In the acrylic emulsion of the present invention, when the amount of dicyclopentenyloxyethyl acrylate and / or dicyclopentenyloxyethyl methacrylate used is 20 to 100% by weight, it is typified by polypropylene which is a nonpolar plastic which is considered to be hardly adhesive. There is a tendency to have good wettability, compatibility and adhesion to various materials such as polyolefin, polyamide having polarity and represented by nylon widely used as engineering plastic.

  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) Heating residue (%)
Measured according to JIS K 5407: 1997. The measurement condition of the heating residue was set at 140 ° C. for 60 minutes.

3) Polymerization rate of acrylic prepolymer Heated residue was measured according to JIS K 5407: 1997, and this was defined as the polymerization rate. The measurement condition of the heating residue was set at 140 ° C. for 60 minutes.

4) Number average molecular weight (Mn), weight average molecular weight (Mw)
Gel permeation chromatography (GPC) “HLC-8220GPC” (test equipment of Tosoh Corporation) was used, and measurement was performed using tetrahydrofuran as a carrier and polystyrene as a molecular weight standard. The molecular weight distribution was calculated by Mw / Mn.

5) pH / 25 ° C
Measurement was performed at 25 ° C. using a pH meter.

6) Particle size The particle size was measured using a dense particle size analyzer “FPAR-1000” manufactured by Otsuka Electronics.

7) Adhesiveness A cross cut test was performed according to JIS K 5400: 1997. Dilute the acrylic emulsion with ion-exchanged water to a concentration of 20%, add 1.0% of “DYNOL406” (air products paint additive; antifoaming, wet agent), and then add it to a polypropylene test piece. The coating was applied so that the coating thickness was 10 μm. After drying at 140 ° C. for 30 minutes, the adhesion test was performed.

8) Solvent resistance After diluting the acrylic emulsion with ion-exchanged water to a concentration of 20%, and adding 1.0% of “DYNOL406” (air products paint additive; antifoaming, slipping agent), It apply | coated so that the coating-film thickness might be set to 10 micrometers on the test piece made from a polypropylene. After drying at 140 ° C. for 30 minutes, the film was rubbed with absorbent cotton containing acetone to evaluate the solubility of the coating film. The evaluation criteria were as follows.
○: The coating film does not dissolve in acetone and has solvent resistance.
(Triangle | delta): Although a coating film does not melt | dissolve easily, if it rubs 20 times or more, a coating film will melt | dissolve and the background of a polypropylene will appear.
X: The coating film is easily dissolved in acetone.
Above Δ, the solvent resistance is good and practical.

Example 1
Nitrogen gas was blown into a 2 L four-necked flask equipped with a stirrer, nitrogen gas inlet, reflux condenser, and temperature sensor, and it was confirmed that the oxygen concentration in the flask was 3.0 vol% or less. Thereafter, nitrogen gas blowing was continued during the production of the acrylic prepolymer P-1. The gas phase temperature in the flask was 25 ° C.

  The flask was charged with 1000 g of dicyclopentenyloxyethyl methacrylate, 22.2 g of 1-phenylethyl-pentafluorophenyl dithioacetate, and 5.0 g of 2,2′-azobis (2,4-dimethylvaleronitrile). At this time, the liquid temperature of the acrylic monomer mixture was 22 ° C., and the oxygen concentration in the gas phase was 2.0 vol% or less. The temperature increase was started and the temperature was increased from 30 ° C. to the polymerization temperature of 85 ° C. in 120 minutes. After the temperature increase, polymerization was performed for 6 hours, and acrylic prepolymer P-1 was produced by bulk radical polymerization.

  During the production of the acrylic prepolymer P-1, no sudden heat generation or viscosity increase was observed, and the production was safe.

  The acrylic prepolymer P-1 had a polymerization rate of 99.2%, a number average molecular weight of 4500, a weight average molecular weight of 5100, and a molecular weight distribution of 1.13.

  Table 1 shows the details of the polymerization formulation and the characteristic values of the acrylic prepolymer P-1. In the table, (1) is an acrylic monomer, (2) 1-phenylethyl-pentafluorophenyl dithioacetate of a dithioester compound, (3) is a polymerization initiator, and (4) is a polymerization condition of an acrylic prepolymer. , (5) showed the characteristic values of the acrylic prepolymer.

  Nitrogen gas was blown into a 1 L four-necked flask equipped with a stirrer, a nitrogen gas blowing port, a reflux condenser, and a temperature sensor, and the atmosphere in the flask was replaced with nitrogen gas. Thereafter, blowing of nitrogen gas was continued during the production of acrylic emulsion AE-1.

  Nitrogen gas was bubbled into the flask and 105.9 g of ion-exchanged water (initial charge) (initial charge) (Table 6 (3)) previously deoxygenated was charged, and the temperature was raised. At 60 ° C., 1.0 g of a polymerization initiator 2,2-azobis [2- (2-imidazolin-2-yl) propane] (Table 6 (5)) was added, and the mixture was stirred at 60 ° C. for 60 minutes to initiate polymerization. The agent was dissolved in ion exchange water. The temperature increase was started and the temperature was increased to 63 ° C.

  25 g of acrylic prepolymer P-1 (Table 6 (1)), acrylic monomer mixture (dicyclopentenyloxyethyl methacrylate (Table 6 (2)) 65 g, isobornyl methacrylate 5 g, methacrylic acid 5 g) 75 g, ion exchange Water (for emulsification) (Table 6 (3)) 46.3 g, “Adekariasorb SR-1025” (an anionic reactive emulsifier having an allyl group in the molecule manufactured by Asahi Denka Kogyo) (Table 6 (4)) 21 .1 g of the mixture was emulsified at 5000 rpm for 10 minutes using an emulsifier to prepare a pre-emulsion.

  30% by weight of the pre-emulsion was added to the flask and heated to 75 ° C. After emulsion polymerization at 75 ° C. for 60 minutes, the remaining amount of 70% by weight of the pre-emulsion was fed into the flask in 2 hours. After completion of the feed, emulsion polymerization was further performed for 60 minutes, the mixture was cooled to 40 ° C. or lower, and 114.3 g of ion-exchanged water (for dilution) (Table 6 (3)) was added to produce an acrylic emulsion AE-1.

  The acrylic emulsion AE-1 had a heating residue of 24.2%, a pH / 25 ° C. of 4.6, and a particle size of 140 nm.

  As shown in Table 6, the acrylic emulsion AE-1 had good compatibility with polypropylene, wettability, and adhesion. At the same time, the solvent resistance was at a practical level.

  In Table 6, (6) indicates the characteristic value of the acrylic emulsion, and (7) indicates adhesion to polypropylene and solvent resistance.

Examples 2-56
Table 1 (Acrylic prepolymers P-5 to P-8), Table 2 (Acrylic prepolymers P-5 to P-8), Table 3 (Acrylic prepolymers P-9 to P12) ), And Table 4 (acrylic prepolymers P-13 to P-16), acrylic prepolymers P-2 to P-16 were produced in the same manner as in Example 1.

  In Tables 1 to 4, (1) is an acrylic monomer, (2) 1-phenylethyl-pentafluorophenyl dithioacetate or benzyl-pentafluorophenyl dithioacetate of a dithioester compound, (3) is a polymerization initiator, (4) shows the polymerization conditions of the acrylic prepolymer, and (5) shows the characteristic values of the acrylic prepolymer.

  As shown in Tables 1 to 4, the acrylic prepolymer could be produced safely without problems and troubles such as stirring and heat removal.

  Table 5 (acrylic emulsions AE-2 to AE-8), Table 6 (acrylic emulsions AE-9 to AE-16), Table 7 (acrylic emulsions AE-17 to AE-24), Table 8 (acrylic emulsion AE-25 to AE-32), Table 9 (acrylic emulsion AE-33 to AE-36), Table 10 (acrylic emulsion AE-37 to AE-44), Table 11 (acrylic emulsion AE-45) To AE-52) and Table 12 (acrylic emulsions AE-53 to AE-56), acrylic emulsions AE-2 to AE-56 were produced in the same manner as in Example 1. The method for producing the acrylic emulsion of Example 2 is described in the column of AE-2.

  In Tables 5 to 12, (1) is an acrylic prepolymer, (2) is an acrylic monomer, (3) is ion-exchanged water, and (4) Adecare Sorb SR-1025 has an allyl group in the molecule. “Adekariasorb SR-1025” (manufactured by Asahi Denka Kogyo Co., Ltd.), which is a reactive emulsifier, (5) is a water-soluble organic azo polymerization initiator having an imidazoline bond in the molecule (2,2-azobis [2- (2-imidazoline) -2-yl) propane]), (6) shows the characteristic values of the acrylic emulsion, and (7) shows adhesion to polypropylene and solvent resistance.

  As shown in Tables 5 to 12, acrylic emulsions could be produced without any problems. Further, since dicyclopentenyloxyethyl methacrylate was used, the compatibility with polypropylene and the wettability were good, and the adhesion was excellent.

  An acrylic emulsion obtained by emulsion polymerization of a carboxyl group-containing acrylic monomer (methacrylic acid) had a low pH / 25 ° C. and became an acidic side. The acrylic emulsion obtained by emulsion polymerization of an epoxy group-containing acrylic monomer (glycidyl methacrylate, vinylbenzyl glycidyl ether) became neutral to weakly alkaline at pH / 25 ° C. An acrylic emulsion obtained by emulsion polymerization of an amino group-containing acrylic monomer (4-methacryloyloxy-2,2,6,6-tetramethylpiperidine) had an alkali side of pH / 25 ° C. An acrylic emulsion obtained by emulsion polymerization of a urea group-containing acrylic monomer (N- (2-methacryloyloxyethyl) ethylene urea) became weakly alkaline to alkaline at pH / 25 ° C. All acrylic emulsions showed the designed pH / 25 ° C.

  The produced acrylic emulsion showed good solvent resistance. In particular, an acrylic emulsion obtained by emulsion polymerization of an amino group-containing acrylic monomer (4-methacryloyloxy-2,2,6,6-tetramethylpiperidine), a urea group-containing acrylic monomer (N- (2-methacryloyloxyethyl) Acrylic emulsion obtained by emulsion polymerization of) ethylene urea) had good solvent resistance. Furthermore, as shown in Tables 7 to 12, when a functional group was used in the acrylic prepolymer, it had excellent solvent resistance.

Comparative Example 1
Nitrogen gas was blown into a 2 L four-necked flask equipped with a stirrer, nitrogen gas inlet, reflux condenser, and temperature sensor, and it was confirmed that the oxygen concentration in the flask was 3.0 vol% or less. Thereafter, nitrogen gas blowing was continued during the production of the acrylic prepolymer P-17. The gas phase temperature in the flask was 25 ° C.

  The flask was charged with 1000 g of n-butyl methacrylate, 95.0 g of α-methylstyrene dimer, and 10.0 g of 2,2′-azobis (2,4-dimethylvaleronitrile). At this time, the liquid temperature of the acrylic monomer mixture was 22 ° C., and the oxygen concentration in the gas phase was 2.0 vol% or less. The temperature increase was started and the temperature was increased from 30 ° C. to the polymerization temperature of 85 ° C. in 120 minutes. After raising the temperature, polymerization was carried out for 6 hours, and acrylic prepolymer P-17 was produced by bulk radical polymerization.

  During the production of the acrylic prepolymer P-17, no sudden heat generation or viscosity increase was observed, and the production was safe.

  The acrylic prepolymer P-17 had a polymerization rate of 99.0%, a number average molecular weight of 8,200, a weight average molecular weight of 16,300, and a molecular weight distribution of 1.99.

  Table 13 shows the details of the polymerization formulation and the characteristic values of the acrylic prepolymer P-17. In Table 13, (1) is an acrylic monomer, (2) is an α-methylstyrene dimer, (3) is a polymerization initiator, (4) is a polymerization condition of the acrylic prepolymer, and (5) is an acrylic prepolymer. The characteristic values of the polymer are shown.

  Nitrogen gas was blown into a 1 L four-necked flask equipped with a stirrer, a nitrogen gas blowing port, a reflux condenser, and a temperature sensor, and the atmosphere in the flask was replaced with nitrogen gas. Thereafter, blowing of nitrogen gas was continued during the production of acrylic emulsion AE-57.

  Nitrogen gas was bubbled into the flask and 105.9 g of ion-exchanged water (initial charge) (initial charge) (Table 14 (3)) previously deoxygenated was charged, and the temperature was raised. At 60 ° C., 1.0 g of a polymerization initiator 2,2-azobis [2- (2-imidazolin-2-yl) propane] (Table 14 (5)) was added and stirred at 60 ° C. for 60 minutes to initiate polymerization. The agent was dissolved in ion exchange water. The temperature increase was started and the temperature was increased to 63 ° C.

  125 g of acrylic prepolymer P-6 (Table 14 (1)), acrylic monomer mixture (65 g of n-butyl methacrylate, 5 g of isobornyl methacrylate, 5 g of methacrylic acid) (Table 14 (2)) 75 g, ion-exchanged water (For emulsification) (Table 14 (3)) 46.3 g, “Adekariasorb SR-1025” (an anionic reactive emulsifier having an allyl group in the molecule manufactured by Asahi Denka Kogyo) (Table 14 (4)) 1 g of the mixture was emulsified at 5000 rpm for 10 minutes using an emulsifier to prepare a pre-emulsion.

  30% by weight of the pre-emulsion was added to the flask and heated to 75 ° C. After emulsion polymerization at 75 ° C. for 60 minutes, the remaining amount of 70% by weight of the pre-emulsion was fed into the flask in 2 hours. After completion of the feed, emulsion polymerization was further performed for 60 minutes, the mixture was cooled to 40 ° C. or lower, and 114.3 g of ion-exchanged water (for dilution) (Table 14 (3)) was added to produce an acrylic emulsion AE-57.

  The acrylic emulsion AE-57 had a heating residue of 23.3%, pH / 25 ° C. of 4.5, and a particle size of 520 nm.

  In Table 14, (6) indicates the characteristic value of the acrylic emulsion, and (7) indicates adhesion to polypropylene and solvent resistance.

Comparative Examples 2-4
Acrylic prepolymers P-17 to P-21 were produced in the same manner as in Comparative Example 1 except that the composition and production conditions of the acrylic prepolymer were changed as shown in Table 13 (acrylic prepolymers P-17 to P-21). Acrylic emulsions AE-56 to AE-60 were produced in the same manner as in Comparative Example 1 except that the composition and production method of the acrylic emulsion were changed as shown in Table 14 (acrylic emulsions AE-58 to AE-60).

  In Table 13, (1) is an acrylic monomer, (2) α-methylstyrene dimer or dithioester compound 1-phenylethyl-phenyldithioacetate, (3) is a polymerization initiator, and (4) is an acrylic prepolymer. (5) shows the characteristic value of the acrylic prepolymer.

  In Table 14, (1) is an acrylic prepolymer, (2) is an acrylic monomer, (3) is ion-exchanged water, and (4) Adecare Sorb SR-1025 is an anionic reactive emulsifier having an allyl group in the molecule. "Adekariasorb SR-1025" (manufactured by Asahi Denka Kogyo Co., Ltd.), (5) is a water-soluble organic azo polymerization initiator having an imidazoline bond in the molecule (2,2-azobis [2- (2-imidazoline-2- I) Propane]), (6) shows the characteristic values of the acrylic emulsion, and (7) shows adhesion to polypropylene and solvent resistance.

  When the amount ratio of α-methylstyrene dimer or dithioester compound 1-phenylethyl-phenyldithioacetate and polymerization initiator is not appropriate as seen in the production of acrylic prepolymers P-19 and P-21 in Table 13 Due to the rapid heat of polymerization, bulk polymerization of the acrylic prepolymer could not be carried out. Further, as seen in the acrylic prepolymer P-20, the polymerization did not proceed at all.

  Acrylic emulsions AE-56 to AE-60 are acrylic prepolymers P-17 and P-18, and the dithioester compound 1-phenylethyl-phenyldithioacetate is not used. This was probably due to the macrophase separation of the particles, but the particle size increased abnormally, and a tendency to separate and precipitate was observed. In the acrylic emulsions AE-56 to AE-60, clear layer separation of the emulsion occurred within one week.

  As shown in Table 14, since acrylic emulsions AE-56 to AE-60 do not use dicyclopentenyloxyethyl methacrylate for both the acrylic prepolymer and the emulsion, they are not compatible with polypropylene, do not have stickiness, and are completely adherent. Did not show. In addition, the macrophase separation was insufficient in crosslinkability and did not have solvent resistance.

Claims (9)

The acrylic monomer is bulk polymerized using 0.020-0.400 mol of the polymerization initiator with respect to 1.0 mol of the dithioester compound, and the acrylic monomer is added in the presence of the obtained acrylic prepolymer. A method for producing an acrylic emulsion for emulsion polymerization. The dithioester compound is represented by the following structural formula

(Where Z is a phenyl group, a benzyl group, a chemical structure represented by the following structural formula

(Pentafluorobenzyl group)

(Pentafluorophenyl group)
Represents one of the following:
R ₁ represents a hydrogen atom, a nitrile group, or an alkyl group having 1 to 4 carbon atoms, R ₂ represents a hydrogen atom, a nitrile group, or an alkyl group having 1 to 4 carbon atoms, R ₃ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a hydroxyethyl group, a hydroxypropyl group, a carboxylethyl group, a carboxypropyl group, an aminoethyl group, an aminopropyl group, a phenyl group, or a substituted group. Phenyl group having a group (however, the substituent is a nitrile group, an alkyl group having 1 to 4 carbon atoms, a hydroxyl group, a hydroxyethyl group, a hydroxypropyl group, a carboxyl group, a carboxyethyl group, a carboxypropyl group, a sulfonyl group) And a salt, an amino group, an aminoethyl group, or an aminopropyl group.)
Represents. )
The method for producing an acrylic emulsion according to claim 1, which is a dithioester compound. The method for producing an acrylic emulsion according to claim 1, wherein a water-soluble organic azo polymerization initiator is used as the polymerization initiator, and an anionic reactive emulsifier having an allyl group in the molecule is used as the emulsifier. . In the presence of acrylic prepolymer,

The method for producing an acrylic emulsion according to any one of claims 1 to 3, wherein pH / 25 ° C when an acrylic monomer containing methacrylic acid is emulsion-polymerized is 4.0 to 7.0. In the presence of acrylic prepolymer,

The method for producing an acrylic emulsion according to any one of claims 1 to 3, wherein pH / 25 ° C when an acrylic monomer containing glycidyl methacrylate is emulsion-polymerized is 6.0 to 8.0. In the presence of acrylic prepolymer,

The method for producing an acrylic emulsion according to any one of claims 1 to 3, wherein pH / 25 ° C when an acrylic monomer containing vinylbenzyl glycidyl ether is emulsion-polymerized is 6.0 to 8.0. In the presence of acrylic prepolymer,

The pH / 25 ° C when an acrylic monomer containing 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine is emulsion-polymerized is 8.0 to 10.0. A process for producing an acrylic emulsion according to claim 1. In the presence of acrylic prepolymer,

The acrylic resin according to any one of claims 1 to 3, wherein pH / 25 ° C when emulsion polymerization of an acrylic monomer containing N- (2-methacryloyloxyethyl) ethylene urea is 7.0 to 10.0. Method for producing emulsion. The acrylic monomer is represented by the following structural formula

(Here, R ₄ represents a hydrogen atom or a methyl group.)
The method for producing an acrylic emulsion according to any one of claims 1 to 7, comprising dicyclopentenyloxyethyl acrylate and / or dicyclopentenyloxyethyl methacrylate.