JP2011241324A - Method of manufacturing aqueous emulsion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen a particle size of a resin in an aqueous emulsion in order to form a thin coating surface with good appearance using an aqueous emulsion material of a small amount since that a coarse particle in an aqueous emulsion is removed, and thereby a uniform coating surface can be formed by a thinner thickness comparing with an aqueous emulsion containing a coarse particle, and an amount of an emulsion which coating requires can be reduced.SOLUTION: The coarse particle in the aqueous emulsion can be removed by the manufacturing method of the aqueous emulsion which includes: a process which emulsifies a resin in water; a process which filters an emulsified product obtained at the previous process; and a process which collects a filtrate obtained at the previous process.

Description

  The present invention relates to a method for producing an aqueous emulsion used for adhesives and paints.

  Aqueous emulsions are generally used for paints and adhesives. For example, Patent Document 1 describes an aqueous emulsion suitable for an adhesive, a coating material, a coating primer, a coating material or a printing binder.

JP 2008-63557 A

  When applying an aqueous emulsion as a paint or an adhesive, it has been found that if the coarse particles present in the aqueous emulsion are removed, irregularities generated on the coated surface can be suppressed. Moreover, by removing coarse particles, it becomes possible to form a uniform coating surface with a thinner thickness compared to an aqueous emulsion containing coarse particles, and the amount of emulsion required for coating can be reduced. I found it possible. Accordingly, there is a demand for a method for selectively removing coarse particles present in an aqueous emulsion to obtain an aqueous emulsion excellent in coatability.

Under such circumstances, the present inventors have further studied, and as a result, have reached the invention described below. That is, the present invention
Emulsifying the resin in water;
The emulsion obtained in the previous step is filtered using a depth filter, and the filtrate is recovered.

  According to the method of the present invention, coarse particles in the aqueous emulsion can be removed.

  Examples of the resin used in the present invention include thermoplastic resins, thermosetting resins, and rubbers.

  Examples of the thermoplastic resin include polyvinyl acetate, polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polyethylene resin, chlorinated polyethylene resin, ethylene-vinyl acetate copolymer resin, ethylene-acrylic acid copolymer resin, ethylene -Acrylic ester copolymer resin, ethylene-methacrylic acid copolymer resin, ethylene-methacrylic acid ester copolymer resin, ethylene-glycidyl methacrylate copolymer resin, ethylene-acrylic acid ester-glycidyl methacrylate copolymer Resin, ethylene-vinyl compound copolymer, polypropylene resin, propylene-vinyl compound copolymer, chlorinated polypropylene resin, polybutene resin, poly (4-methyl-1-pentene) resin, polystyrene resin, polyester system Fat, polyamide resin, polyphenylene ether resin, polyacetal resin, polycarbonate resin, ethylene-cycloolefin copolymer resin, ionomer, chlorinated polypropylene, polystyrene, polyvinyl chloride, plastisol, vinyl chloride-vinyl acetate copolymer , Polyvinyl ether, polyvinyl pyrrolidone, polyamide, nylon, saturated amorphous polyester, cellulose derivatives and the like.

  Examples of the thermosetting resin include urea resin, melamine resin, phenol resin, resorcinol resin, epoxy resin, polyurethane, and vinyl urethane.

  Examples of rubber include natural rubber, synthetic polyisoprene, polychloroprene, nitrile rubber, styrene-butadiene rubber, styrene-butadiene-vinylpyridine terpolymer, polyisobutylene-butyl rubber, polysulfide rubber, silicone RTV, chlorinated rubber, Examples thereof include bromide rubber, kraft rubber, block copolymer, and liquid rubber.

  The method of the present invention is a thermoplastic resin, in particular, ethylene-vinyl compound copolymer, propylene-vinyl compound copolymer, polyvinyl acetate, polyvinyl alcohol, chlorinated polyethylene, chlorinated polypropylene, polyethylene resin, polypropylene resin. , Ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer resin, ethylene-acrylic acid ester copolymer resin, ethylene-methacrylic acid copolymer Suitable for coalescing resin, ethylene-methacrylic acid ester copolymer resin, ethylene-glycidyl methacrylate copolymer resin.

In particular, the method of the invention
Structural units derived from ethylene and / or linear α-olefins;
Formula (I)

_{CH 2 = CH-R (I} )

(In the formula, R represents a secondary alkyl group, a tertiary alkyl group, or an alicyclic hydrocarbon group.)
And an olefin copolymer (hereinafter referred to as “polymer (A-1)”) containing a structural unit derived from a vinyl compound represented by the formula (hereinafter sometimes referred to as “vinyl compound (I)”). Or a polymer obtained by graft polymerization of an α, β-unsaturated carboxylic acid anhydride to the polymer (A-1) (hereinafter sometimes referred to as “polymer (A-2)”). Is suitable. Hereinafter, the polymer (A-1) and the polymer (A-2) may be collectively referred to as “polymer (A)”.

  The substituent R of the vinyl compound (I) is a secondary alkyl group, a tertiary alkyl group, or an alicyclic hydrocarbon group. Specific examples of the vinyl compound (I) include vinylcyclohexane.

  The polymer (A-1) may further contain a structural unit derived from a linear α-olefin having 4 to 20 carbon atoms.

  The polymer (A-1) may further be copolymerized with a monomer capable of addition polymerization. Here, the addition-polymerizable monomer is a monomer other than ethylene, propylene, a linear α-olefin having 4 to 20 carbon atoms, and the vinyl compound (I), and ethylene, propylene, having 4 to 20 carbon atoms. It is a monomer that can undergo addition polymerization with a linear α-olefin and vinyl compound (I), and the carbon number of the monomer is usually about 3 to 20.

  As a method for producing the polymer (A-1), for example, a method produced in the presence of a catalyst comprising a transition metal compound having a group having an indenyl type anion skeleton or a crosslinked cyclopentadiene type anion skeleton. Etc. Among these, the production method according to the methods described in JP-A No. 2003-82028, JP-A No. 2003-160621 and JP-A No. 2000-128932 is preferable.

  The molecular weight distribution (Mw / Mn = [weight average molecular weight] / [number average molecular weight]) of the polymer (A-1) is usually about 1.5 to 10, preferably about 1.5 to 7, especially Preferably it is about 1.5-5. From the viewpoint of mechanical strength, the weight average molecular weight (Mw) of the polymer (A-1) is usually about 5,000 to 1,000,000, preferably about 10,000 to 500,000. Especially preferably, it is about 15,000 to 400,000. The molecular weight distribution of the polymer (A-1) can be determined using gel permeation chromatograph (GPC) in accordance with the method specifically described in Examples below.

  The melt flow rate (MFR) of the polymer (A-1) measured under conditions of 190 ° C. and 2.16 kgf using a melt indexer (L217-E14011, manufactured by Techno Seven Co.) in accordance with JIS K 7210. The value of is usually 130 to 300 g / 10 minutes, preferably 130 to 220 g / 10 minutes, from the viewpoint of dispersibility.

  The polymer (A-2) is a polymer obtained by graft polymerization of an α, β-unsaturated carboxylic acid anhydride to the polymer (A-1) thus obtained. As the α, β-unsaturated carboxylic acid anhydride, maleic anhydride is preferable.

Examples of the method for producing the polymer (A-2) include a method in which the polymer (A-1) is melted, and then α, β-unsaturated carboxylic acid anhydride is added and graft polymerization is performed. Examples thereof include a method in which a polymer is dissolved in a solvent such as toluene and xylene, and then α, β-unsaturated carboxylic acid anhydride is added to cause graft polymerization.
After the polymer (A-1) is melted, the α, β-unsaturated carboxylic acid anhydride is added and graft polymerization is performed by melt-kneading using an extruder, so that the resins or the resin and the solid can be solidified. Alternatively, it is preferable because various known methods for mixing liquid additives can be employed. More preferable examples include a method in which all or some of the components are combined and mixed separately with a Henschel mixer, a ribbon blender, a blender or the like to form a uniform mixture, and then the mixture is melt-kneaded. it can.
As the melt-kneading means, conventionally known kneading means such as a Banbury mixer, a plast mill, a Brabender plastograph, a uniaxial or biaxial extruder can be widely employed. Particularly preferable is an olefin copolymer, unsaturated carboxylic acid, radical initiator, which is sufficiently premixed in advance using a single-screw or twin-screw extruder from the viewpoint that continuous production is possible and productivity is improved. A method is recommended in which kneading is carried out by feeding from the feed port of the extruder.
The temperature of the portion where the melt kneading of the extruder is carried out (for example, the cylinder temperature in the case of an extruder) is usually 50 to 300 ° C, preferably 80 to 270 ° C. The temperature of the portion of the extruder where the melt kneading is performed is preferably set so that the melt kneading is divided into two stages, the first half and the second half, and the temperature in the second half is higher than the first half. The melt kneading time is usually 0.1 to 30 minutes, particularly preferably 0.1 to 5 minutes.

In order to graft polymerize the α, β-unsaturated carboxylic acid anhydride to the polymer (A-1), the polymerization is usually carried out in the presence of a radical initiator.
The addition amount of the radical initiator is 0.01 to 10 parts by weight, preferably 0.01 to 1 part by weight with respect to 100 parts by weight of the polymer (A-1).
The radical initiator is usually an organic peroxide, preferably an organic peroxide having a decomposition temperature of 50 to 210 ° C. with a half-life of 1 minute. In addition, these organic peroxides preferably have an action of extracting protons from the polymer (A-1) after being decomposed to generate radicals.

  Examples of the organic peroxide having a decomposition temperature of 50 to 210 ° C. with a half-life of 1 minute include 1,3-bis (t-butylperoxyisopropyl) benzene. The addition amount of the organic peroxide is 0.01 to 20 parts by weight, preferably 0.05 to 10 parts by weight with respect to 100 parts by weight of the polymer (A-1).

  The structural unit derived from the α, β-unsaturated carboxylic acid anhydride contained in the polymer (A-2) thus obtained was a ring-opened one even if the acid anhydride group remained closed. The ring-closed one and the ring-opened one may be contained.

  Examples of the molecular weight distribution (Mw / Mn) of the polymer (A-2) in the aqueous emulsion of the present invention include 1.5 to 10 and the like. Preferably 1.5-7 grade | etc., More preferably, 1.5-5 grade | etc., Is mentioned. The molecular weight distribution of the polymer (A-2) can be measured in the same manner as the molecular weight distribution of the polymer (A-1).

  The melt flow rate (MFR) of the polymer (A-2) measured under the conditions of 190 ° C. and 2.16 kgf using a melt indexer (L217-E14011, manufactured by Techno Seven Co.) in accordance with JIS K 7210. From the viewpoint of dispersibility, the value of is preferably from 130 to 300 g / 10 min, and particularly preferably from 130 to 200 g / 10 min.

Examples of the emulsifier suitable for emulsifying the resin used in the method of the present invention include amphoteric emulsifiers, cationic emulsifiers, anionic emulsifiers, and nonionic emulsifiers. These emulsifiers may be used alone or in combination of at least two kinds. The emulsifier can also be used in an aqueous solution state.
Examples of the amphoteric emulsifier include laurylamidopropyl acetate betaine and laurylaminoacetate betaine.
Examples of the cationic emulsifier include alkyl trimethyl ammonium salts and dialkyl dimethyl ammonium salts. Examples of the alkyltrimethylammonium salt include coconut alkyltrimethylammonium chloride, cetyltrimethylammonium chloride, stearyltrimethylammonium chloride, hebenyltrimethylammonium chloride and the like. Examples of the dialkyldimethylammonium salt include didecyldimethylammonium chloride, dicocoyldimethylammonium chloride, and dioleyldimethylammonium chloride.
Examples of the anionic emulsifier include monoalkyl sulfonates, alkyl polyoxyethylene sulfonates, monoalkyl benzene sulfonates, and monoalkyl phosphates. Examples of monoalkyl sulfonates include sodium octyl sulfonate, sodium lauryl sulfonate, sodium pentadecyl sulfonate, sodium myristyl sulfonate, sodium stearyl sulfonate, and the like. Examples of alkyl polyoxyethylene sulfonates include sodium octyl polyoxyethylene sulfonate, sodium lauryl polyoxyethylene sulfonate, sodium pentadecyl polyoxyethylene sulfonate, sodium myristyl polyoxyethylene sulfonate, stearyl polyoxyethylene sulfone. Examples include sodium acid. Examples of monoalkylbenzene sulfonates include sodium octyl benzene sulfonate, sodium lauryl benzene sulfonate, sodium pentadecyl benzene sulfonate, sodium myristyl benzene sulfonate, sodium stearyl benzene sulfonate, and the like. Examples of monoalkyl phosphates include sodium monooctyl phosphate, sodium monolauryl phosphate, sodium monopentadecyl phosphate, sodium monomyristyl phosphate, sodium monostearyl phosphate, and the like.
Examples of the anionic emulsifier include water-soluble acrylic resins containing a structural unit derived from an α, β-unsaturated carboxylic acid and a structural unit derived from an α, β-unsaturated carboxylic acid ester. As the anionic emulsifier, such a water-soluble acrylic resin is preferable. Hereinafter, it may be simply referred to as “water-soluble acrylic resin”. Here, as the α, β-unsaturated carboxylic acid, for example, acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, nadic acid, methyl nadic acid, highmic acid, Examples include angelic acid, tetrahydrophthalic acid, sorbic acid, and mesaconic acid. As the α, β-unsaturated carboxylic acid, plural kinds of α, β-unsaturated carboxylic acids may be used. As the α, β-unsaturated carboxylic acid, acrylic acid and methacrylic acid are particularly preferable.
Examples of the nonionic emulsifier include polyoxyethylene alkyl ether, polyoxyethylene phenyl ether, polyoxyethylene sorbitan alkylate, polyoxyethylene oxypropylene block copolymer, and polyglycerin ester.

As the water-soluble acrylic resin, in particular,
a structural unit derived from an α, β-unsaturated carboxylic acid (1);
An α, β-unsaturated carboxylic acid ester (2) (hereinafter referred to as “α, β”) containing a C 1-10 alkyl group having a hydroxyl group bonded to a methylene group or methine group and an α, β-unsaturated carboxylic acid. -An acrylic resin (B) containing a structural unit derived from an unsaturated carboxylic acid ester (2) "may be suitable.

  Examples of “α, β-unsaturated carboxylic acid (1)” include acrylic acid and methacrylic acid.

  Examples of the “α, β-unsaturated carboxylic acid ester (2)” include 2-hydroxyethyl methacrylate.

  The acrylic resin (B) is necessary in addition to “structural unit derived from α, β-unsaturated carboxylic acid (1)” and “structural unit derived from α, β-unsaturated carboxylic acid ester (2)”. According to the above, “a structural unit derived from an α, β-unsaturated carboxylic acid ester containing an alkyl group having 1 to 20 carbon atoms and an α, β-unsaturated carboxylic acid”, “1 to 1 carbon atoms having an amino group” A structural unit derived from an α, β-unsaturated carboxylic acid ester comprising 10 alkyl groups and an α, β-unsaturated carboxylic acid ”,“ an alkyl group having 1 to 10 carbon atoms having a carboxy group (—COOH) ”, and A structural unit derived from an α, β-unsaturated carboxylic acid ester including an α, β-unsaturated carboxylic acid ”may be contained.

  Examples of the “α, β-unsaturated carboxylic acid ester containing an alkyl group having 1 to 20 carbon atoms and an α, β-unsaturated carboxylic acid” include ethyl acrylate and lauryl methacrylate.

  Examples of the “α, β-unsaturated carboxylic acid ester containing an amino group having 1 to 10 carbon atoms and an α, β-unsaturated carboxylic acid” include N, N-dimethylaminoethyl methacrylate and the like. Is mentioned.

  Examples of the “α, β-unsaturated carboxylic acid ester containing a C 1-10 alkyl group having a carboxy group and an α, β-unsaturated carboxylic acid” include, for example, 2-acryloyloxyethyl succinic acid and the like. Can be mentioned.

  The structural unit derived from these α, β-unsaturated carboxylic acid esters contained in the acrylic resin (B) as necessary is a structural unit derived from a plurality of different α, β-unsaturated carboxylic acid esters. May be used.

  As a manufacturing method of the acrylic resin (B) in this invention, it can manufacture by carrying out addition polymerization of the said monomer mixture, for example. Specifically, for example, alcohol such as isopropyl alcohol or water is used as a solvent, and a part or all of the monomer is mixed in the solvent, and usually 70 ° C to 100 ° C, preferably 75 ° C to 95 ° C, particularly preferably. Is a method in which a polymerization initiator such as a radical initiator and the remaining monomers are mixed at 75 ° C. to 85 ° C., and usually stirred for about 1 to 24 hours. In order to control the reaction, the polymerization initiator and the remaining monomers may be dissolved in an organic solvent and then added.

  Here, examples of the polymerization initiator include 2,2'-azobisisobutyronitrile. The amount of the polymerization initiator used is 0.01 to 5 parts by weight, preferably 0.2 to 3 parts by weight, based on 100 parts by weight of the monomer mixture.

The aqueous emulsion of the present invention preferably has an NH ₃ neutralization degree of, for example, 50 to 300, more preferably 100 to 200. Here, the degree of neutralization of NH ₃ is the ratio of the number of moles of ammonia contained in the aqueous emulsion to the total number of moles of structural units derived from the monomer having an anionic group contained in the acrylic resin (B), that is, [ (Number of moles of ammonia) / (total number of moles of anionic monomer) × 100 (%)]
Means.

[Emulsification process]
The step of emulsifying the resin in water according to the present invention includes, for example, a method of melt-kneading the resin, the emulsifier and water; for example, a heating step of heating the resin, and a mixing step of mixing the emulsifier with the resin heated in the heating step. A method comprising heating and kneading a resin and an emulsifier, and a step of dispersing the kneaded product obtained in the above step in water; for example, dissolution in which the resin is dissolved in an organic solvent such as toluene. It is carried out by a method including a step, a mixing step of mixing the lysate obtained in the dissolving step with an emulsifier, and a removing step of removing the organic solvent from the mixture obtained in the mixing step.
In addition to the mechanical emulsification method as described above, the emulsification step may be performed by a chemical emulsification method such as self-emulsification.
In particular, a method of melt-kneading a resin, an emulsifier and water, a heating step of heating the resin, and a mixing step of mixing the emulsifier with the heated resin obtained in the heating step are suitable.

  Examples of the apparatus used in the step of melting and kneading the resin, the emulsifier, and water as required include, for example, a twin screw extruder, Labo Plast Mill (Toyo Seiki Seisakusho Co., Ltd.), Labo Plast Mill Micro (Toyo Seiki Seisakusho Co., Ltd.) Multi-screw extruder, homogenizer, etc. Equipment with barrel (cylinder) such as TK Filmics (Primics Co., Ltd.), for example, stirring tank, chemical stirrer, vortex mixer, flow jet mixer, colloid mill, ultrasonic generation Equipment without a barrel (cylinder), such as a machine, a high-pressure homogenizer, dispersion (Fujikin Co., Ltd.), a static mixer, and a micromixer.

As a shear rate of the apparatus which has a barrel, it is about 200-100000 second- ¹ normally, Preferably it is about 1000-2500 second- ¹ . Here, the shear rate is a numerical value obtained by dividing the peripheral speed [mm / sec] of the outermost peripheral part of the screw element by the clearance [mm] between the screw and the barrel.

As a method of melt-kneading the resin, emulsifier and water, for example, the resin is continuously supplied from the hopper or supply port of the twin-screw extruder, heated and melt-kneaded, and further the compression zone and metering zone of this extruder. Alternatively, the emulsifier is pressurized and supplied from at least one supply port provided in the degassing zone, and the resin is kneaded with a screw, and then water is supplied from at least one supply port provided in the compression zone of the extruder. The method of extruding and producing an emulsion continuously from a die by feeding is used.
As a method having a heating step of heating a resin and a mixing step of mixing an emulsifier with the heated resin obtained in the heating step, for example, after heating a cylinder of a kneader, the resin is put into the cylinder. , Performing a heating process of melting while rotating, then adding an emulsifier, performing a rotating mixing process, and subsequently pouring and dispersing the resulting mixture in warm water to obtain an emulsion, etc. Is mentioned.

As a method having a heating step of heating the resin and a mixing step of mixing the emulsifier with the heated resin obtained in the heating step, a method using a multi-screw extruder is suitable.
More specifically, first, a heating process in which a resin is supplied from a hopper of a multi-screw extruder having two or more screws in a casing, followed by heating and melt-kneading, then, a compression zone and / or metering of the extruder. Examples thereof include a method of producing an emulsion through a mixing step of dispersing in water while kneading with an emulsifier supplied from at least one liquid supply port provided in the zone.

  In the emulsion obtained by the method of the present invention, a dispersoid containing a resin and an emulsifier is dispersed in water as a dispersion medium.

  The emulsion obtained by the method of the present invention is preferably one in which the dispersoid comprising the polymer (A) and the acrylic resin (B) is dispersed in water as a dispersion medium. The volume-based median diameter of the dispersoid is usually 0.01 to 3 μm, preferably 0.5 to 2.5 μm, more preferably 0.5 to 1.5 μm. When the volume-based median diameter is 0.01 μm or more, it is preferable from the viewpoint of easy production, and when it is 3 μm or less, adhesiveness tends to be improved. Here, the volume-based median diameter is a particle diameter corresponding to 50% of the cumulative particle diameter distribution on a volume basis.

  The content of the emulsifier in the emulsion obtained by the method of the present invention is, for example, 0.01 to 50 parts by weight, preferably 0.1 to 40 parts by weight with respect to 100 parts by weight of the resin. The content of the resin in the emulsion obtained by the method of the present invention is, for example, 0.1 to 70 parts by weight, preferably 10 to 60 parts by weight, more preferably 20 to 60 parts by weight with respect to 100 parts by weight of the emulsion. Part. The content of water in the emulsion obtained by the method of the present invention is, for example, 30 to 99 parts by weight, preferably 40 to 90 parts by weight, more preferably 40 to 80 parts by weight with respect to 100 parts by weight of the emulsion. is there.

  The emulsion of the present invention may contain two or more kinds of resins, such as fillers such as clay, kaolin, talc and calcium carbonate, preservatives, rust preventives, antifoaming agents, foaming agents, and polyacrylic. Thickeners such as acids, polyethers, methylcellulose, carboxymethylcellulose, polyvinyl alcohol, starch, viscosity modifiers, flame retardants, pigments such as titanium oxide, dibasic acid dimethyl succinate, high boiling point solvents such as dimethyl adipate, A plasticizer or the like may be contained.

[Filtering process]
The obtained emulsion is filtered using a depth filter, and the resulting filtrate is recovered. The depth filter is a filter that traps particulate matter in the fluid mainly inside the filter medium, unlike a surface filter (a filter that traps particulate matter in the fluid mainly on the filter surface). The depth filter has a feature of high particle retention performance and less clogging. When a depth filter is used, coarse particles in the emulsion can be selectively removed. Examples of the depth filter include one in which a fiber is wound around a core, one in which a nonwoven fabric is wound around a core, one in which fibers are heat-welded, and one in which fibers are extruded.
Filtration accuracy is important for the selection of depth filters. Filtration accuracy is generally expressed by the size of particles that can be removed by passing through a filter. For example, when the fluid is water and fine dust is filtered with a 10-inch cartridge at a predetermined flow rate, 99.5% or more of particles are captured. The method of expressing by the particle diameter which can be mentioned.
The filtration accuracy of the depth filter suitable for the method of the present invention is, for example, 1 to 50 μm, preferably 2 to 30 μm, more preferably 5 to 30 μm.
Specific examples of the depth filter suitable for the method of the present invention include, for example, a poly clean ^TM series (manufactured by Cuno Co., Ltd., hereinafter referred to as PC) manufactured by extruding polypropylene fiber and a laminated nonwoven fabric made of polypropylene. Polypro Clean ^TM series (manufactured by Cuno Co., Ltd., hereinafter referred to as PPC) and the like. The PPC series has a feature that it is less likely to blow through particles than the PC series. It is preferable to perform filtration by combining two or more depth filters.

  It is preferable to perform preliminary filtration using another filter medium before filtration with a depth filter. The opening size of the filter medium suitable for prefiltration is, for example, 50 to 300 μm, preferably 50 to 200 μm, and more preferably 50 to 100 μm. Specific examples of the filter medium used for the preliminary filtration include a 200 mesh filter cloth.

  The filtration step is performed at a temperature of 5 to 80 ° C., preferably 10 to 75 ° C., and a filtration pressure of 0.001 to 0.3 MPa, preferably 0.01 to 0.2 MPa.

  The cured product obtained by drying water from the aqueous emulsion obtained by the method of the present invention tends to give a smooth surface. Therefore, when the aqueous emulsion obtained by the method of the present invention is applied to a substrate as a coating as described later, the workability tends to be excellent, and the appearance of the resulting cured product tends to be excellent.

  The aqueous emulsion obtained by the method of the present invention is coated (coated) on a substrate, and then dried to form a coating film (coating film) of the aqueous emulsion on the substrate. The coating film can be used, for example, for paints, primers, base materials, adhesives and the like.

  The “base material” in the present invention means an article having an arbitrary shape intended to be coated with the aqueous emulsion of the present invention, such as an adherend and an adherent layer. Examples of the substrate in the present invention include wood-based materials such as wood, plywood, MDF, particle board, and fiber board; paper-based materials such as wallpaper and wrapping paper: cellulosic materials such as cotton, linen, and rayon; polyethylene ( Polyolefins whose main component is a structural unit derived from ethylene (hereinafter the same), polypropylene (polyolefins whose main component is a structural unit derived from propylene, the same applies hereinafter), polyolefins such as polystyrene, polycarbonate, acrylonitrile / butadiene / styrene copolymer Combined (ABS resin), (meth) acrylic resin, plastic materials such as polyester, polyether, polyvinyl chloride, polyurethane, urethane foam; ceramic materials such as glass and ceramics; metal materials such as iron, stainless steel, copper, and aluminum Can be mentioned.

  Such a substrate may be a composite material composed of a plurality of materials. Further, an inorganic filler such as talc, silica, activated carbon, or the like, and a kneaded molded product of carbon fiber or the like and a plastic material may be used.

  As the substrate, among them, polypropylene, polystyrene, polycarbonate, acrylonitrile / butadiene / styrene copolymer (ABS resin), polyethylene terephthalate, polyvinyl chloride, (meth) acrylic resin, glass, aluminum, polyurethane and the like are preferable. Polypropylene, polyvinyl chloride, glass, aluminum and polyurethane are preferred.

When one of the substrates is a water-absorbing substrate such as a wood-based material, a paper-based material, or a cellulosic material, the aqueous emulsion of the present invention can be applied as it is and bonded to another substrate. . That is, after coating an aqueous emulsion on a water-absorbing substrate, if another substrate (which may be water-absorbing or non-water-absorbing) is laminated on the layer derived from the aqueous emulsion, the water content in the aqueous emulsion is The coating film which is absorbed by the water-absorbing substrate and is derived from the aqueous emulsion becomes an adhesive layer, and a laminate having the water-absorbing substrate / the coating film / substrate derived from the aqueous emulsion of the present invention can be obtained.
When the base material is non-water-absorbing, such as polyolefin, after coating the aqueous emulsion on one side of one base material and heating to form a coating film derived from the aqueous emulsion of the present invention, the other base What is necessary is just to bond a material and to heat and to make it adhere | attach further.
Examples of the heating temperature when forming a coating film derived from an aqueous emulsion and the heating temperature after bonding the other substrate and the coating film derived from an aqueous emulsion include 60 to 200 ° C. Can do.

  Accordingly, the present invention also provides a base material comprising at least one material selected from the group consisting of woody materials, cellulosic materials, plastic materials, ceramic materials and metal materials, and a coating derived from the aqueous emulsion of the present invention. A laminate including a film is provided.

  Furthermore, the present invention applies the aqueous emulsion of the present invention to a substrate containing at least one material selected from the group consisting of woody materials, cellulosic materials, plastic materials, ceramic materials and metal materials, The first step of obtaining a coated product comprising the substrate and the layer containing the aqueous emulsion, and the coated product obtained in the first step are dried to derive from the substrate and the aqueous emulsion of the invention. The manufacturing method of a laminated body including the 2nd process of obtaining the laminated body containing a coating film is provided.

  The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. Parts and% in the examples mean weight basis unless otherwise specified.

<Molecular weight and molecular weight distribution>
The molecular weight of the polymer (A-2) was determined under the following conditions after calibrating with a polystyrene (molecular weight 688 to 400,000) standard substance using a gel permeation chromatograph (GPC). The molecular weight distribution was evaluated by the ratio (Mw / Mn) between the weight average molecular weight (hereinafter referred to as Mw) and the number average molecular weight (hereinafter referred to as Mn).
Model Waters 150-C
Column shodex packed column A-80M
Measurement temperature 140 ℃
Measurement solvent Orthodichlorobenzene measurement concentration 1mg / ml

<Content of vinylcyclohexane unit>
Content of the vinylcyclohexane unit in a polymer (A-2) was calculated | required with the following < ¹³ > C-NMR apparatus.
¹³ C-NMR apparatus: DRX600 manufactured by BRUKER
Measuring solvent: orthodichlorobenzene and orthodichlorobenzene-d4
4: 1 (volume ratio) liquid mixture Measurement temperature: 135 ° C

<Graft amount>
The graft amount of maleic anhydride was measured by the following procedure. Dissolve 1.0 g of sample in 20 ml of xylene, drop the sample solution into 300 ml of methanol while stirring to recover the sample by reprecipitation, then vacuum dry the collected sample (80 ° C., 8 hours), and then A film having a thickness of 100 μm was prepared by hot pressing, the infrared absorption spectrum of the obtained film was measured, and the graft amount of maleic acid was quantified from the absorption near 1780 cm ⁻¹ .

<Solid content>
The measurement of solid content was performed by the measuring method according to JIS K-6828.

<Neutralization degree of NH ₃ >
The degree of neutralization of NH ₃ of the acrylic resin (B) is based on the total number of moles of acrylic acid (AA) in the acrylic resin (B) ([AA]) and the number of moles of methacrylic acid (MAA). , The proportion of moles of ammonia used ([NH ₃ ]), ie
([NH ₃ ] / ([AA] + [MAA])) × 100 (%)
Represents.

<Average particle size>
It is a volume-based median diameter obtained using a laser diffraction particle size distribution analyzer LA-910 (manufactured by Horiba, Ltd.) with a particle refractive index of 1.50-0.20i.

<Coarse particle size measurement>
In accordance with the standard JIS K5600-2-5, the emulsion or aqueous emulsion is poured into a deep groove position of a Gardner grindometer (range 0 to 100 μm), and the scraper is pressed in the shallow direction from the deep groove position 1 The scale was pulled at an even speed over ˜2 seconds, and the graduation where 5 or more grains began to appear within 3 seconds after the drawing was finished was read. This measurement was repeated three times, and the average value was defined as the coarse particle diameter. When the coarse particle diameter is large, there is a tendency that large foreign matters exist.

[Example 1]
<Manufacture of resin>
The polymer (A-2) was used as a resin. 386 parts of vinylcyclohexane (hereinafter sometimes referred to as VCH) and 3640 parts of toluene were charged into a SUS reactor substituted with argon. After raising the temperature to 50 ° C., ethylene was charged while being pressurized at 0.6 MPa. 10 parts of a toluene solution of triisobutylaluminum (TIBA) [TIBA concentration 20% manufactured by Tosoh Akzo Co., Ltd.] was charged, followed by diethylsilyl (tetramethylcyclopentadienyl) (3-tert-butyl-5-methyl- 2-phenoxy) titanium dichloride 0.001 part dissolved in dehydrated toluene 87 parts and dimethylanilinium tetrakis (pentafluorophenyl) borate 0.03 part dissolved in dehydrated toluene 122 parts were added. Stir for hours.
The obtained reaction solution was poured into about 10,000 parts of acetone, and the precipitated white solid was collected by filtration. The solid was washed with acetone and then dried under reduced pressure. As a result, 300 parts of a polymer (hereinafter referred to as “polymer (A-1a)”) which was an ethylene / VCH copolymer was obtained. The viscosity (η) of the polymer (A-1a) is 0.48 dl / g, Mn is 15,600, molecular weight distribution (Mw / Mn) is 2.0, melting point (Tm) is 57 ° C., glass transition point (Tg ) Was −28 ° C., and the content of structural units derived from VCH in the polymer (A-1a) was 13 mol%.
To 100 parts of the obtained polymer (A-1a), 0.4 part of maleic anhydride and 0.04 part of 1,3-bis (t-butylperoxyisopropyl) benzene were added and thoroughly premixed. A polymer (hereinafter referred to as “polymer (A-2a)”) obtained by graft polymerization of maleic anhydride to an ethylene / VCH copolymer is obtained by supplying from a supply port of a shaft extruder and melt-kneading. It was. The temperature of the melt kneading part of the extruder was divided into two stages, the first half and the latter half, and the melt kneading was performed at a temperature setting of 180 ° C. in the first half and 260 ° C. in the second half. The maleic acid graft amount of the polymer (A-2a) was 0.2%. The MFR of the polymer (A-2a) was 180 g / 10 minutes (190 ° C., load: 2.16 kgf).

<Manufacture of emulsifier>
Acrylic resin (B) was used as an emulsifier. The monomers listed in Table 1 were used as monomers for the acrylic resin (B).

"AA" 7.5 parts (10.9 mole ratio), "MAA" 22.5 parts (27.4 mole ratio), "HEA" 29.5 parts (26.6 mole ratio), "EA" 29. 5 parts (30.8 molar ratio) and 11.0 parts (4.4 molar ratio) of “SLMA” were mixed at 10 to 30 ° C. to obtain 100 parts of a monomer mixture. Here, the molar ratio represents the number of moles when the total number of moles of the monomers is 100.
A mixture of 100 parts of ion-exchanged water, 150 parts of isopropyl alcohol (hereinafter sometimes referred to as IPA) and 100 parts of the monomer mixture was charged into the reactor and stirred at 80 ° C. under nitrogen substitution. While gradually adding about 0.9 part of 2,2′-azobisisobutyronitrile as a polymerization initiator to the obtained reaction solution, the mixture was stirred at the same temperature and under nitrogen substitution for 3 hours. Subsequently, the temperature of the resulting reaction solution was raised to a boiling point to distill off the IPA. After distilling off, the internal temperature was lowered to 50 ° C., and then 28 parts (46 molar ratio) of 28% aqueous ammonia solution was mixed. Then, water was added and it adjusted so that components (solid content) other than water and ammonia might be 50%, and the viscous acrylic resin (B) was obtained (yield 90%, hereinafter, (B-1 )). Table 2 summarizes the types and amounts of monomers used, the amount of solids, and the amount of aqueous ammonia.

<Emulsification process>
After setting the cylinder temperature of a co-rotating meshing twin screw extruder (manufactured by Nippon Steel Works Co., Ltd .: TEX30φ, L / D = 30) to 110 ° C., the polymer (A -2a) 110 parts were continuously supplied at a screw rotation speed of 350 rpm, and the polymer (A-2a) was heated.
From the supply port provided in the vent part of the extruder, 10 parts (solid content) (B-1) as an emulsifier is continuously supplied while being pressurized with a gear pump, and (B-1) and the polymer (A- 2a) was mixed while being continuously extruded, and then 100 parts of ion-exchanged water was supplied from a supply port provided in the compression zone of the extruder to obtain a milky white emulsion. The average particle size of the particles in the obtained emulsion was 0.6 μm, and the coarse particle size was 30 μm.

<Filtering process>
The emulsion obtained in the emulsification step is filtered through a 200 mesh filter cloth (hereinafter referred to as # 200) at a filtration pressure of 0.05 Mpa or less, then filtered through a depth filter PC10 (filtration accuracy 30 μm), and then depth. Filtration was performed using a filter PC5 (filtration accuracy: 20 μm), and the obtained filtrate was recovered. The recovered filtrate had a coarse particle size of 20 μm.

[Example 2]
In the filtration step, according to Example 1 except that filtration was performed with # 200 at a filtration pressure of 0.04 to 0.06 Mpa, followed by filtration with a depth filter PC10, followed by filtration with a depth filter PPC5 (filtration accuracy 5 μm). An aqueous emulsion filtrate was obtained. The recovered filtrate had a coarse particle size of 5 μm or less.

[Example 3]
A filtrate of an aqueous emulsion was obtained according to Example 3 except that the filtration step was performed at a filtration pressure of 0.09 to 0.11 Mpa. The recovered filtrate had a coarse particle size of 5 μm.

[Example 4]
A filtrate of an aqueous emulsion was obtained according to Example 3 except that the filtration step was performed at a filtration pressure of 0.04 to 0.18 Mpa. The recovered filtrate had a coarse particle size of 20 μm.

[Example 5]
In the filtration step, an aqueous emulsion filtrate was obtained in the same manner as in Example 3 except that filtration was performed with # 200, followed by filtration with a depth filter PC10, followed by filtration with a depth filter PPC10 (filtration accuracy: 10 μm). The recovered filtrate had a coarse particle size of 5 μm or less.

[Example 6]
An aqueous emulsion filtrate was obtained in the same manner as in Example 6 except that the filtration step was performed at a filtration pressure of 0.1 to 0.15 Mpa. The recovered filtrate had a coarse particle size of 20 μm.

[Reference example]
The aqueous emulsion was filtered according to Example 3 except that a filtration step was performed at a filtration pressure of 0.01 to 0.2 MPa using a nylon mesh membrane filter (pore diameter: 10 μm) as a filter medium. The recovered filtrate had a coarse particle size of 5 μm, but it was immediately clogged and could not be filtered.

  Table 3 shows the filter media used in the examples. Table 4 shows the filtration conditions and the coarse particle diameter. When the method of the present invention is used, a small coarse particle size can be achieved without clogging.

  The aqueous emulsion produced by the method of the present invention can give a thin film having an excellent appearance.

Claims (24)

Emulsifying the resin in water;
And a step of filtering the emulsion obtained in the previous step using a depth filter and recovering the filtrate.   The method according to claim 1, wherein the filtration accuracy of the depth filter is 5 to 20 μm.   The method according to claim 1 or 2, wherein the depth filter is made of polypropylene.   The method according to any one of claims 1 to 3, wherein the filtration is performed at a filtration pressure of 0.01 to 0.2 MPa.   The method according to any one of claims 1 to 4, wherein the filtration is performed at a temperature of 10 to 75 ° C.   The method according to any one of claims 1 to 5, wherein the filtration is performed by combining two or more depth filters.   The method according to any one of claims 1 to 6, wherein preliminary filtration is performed before filtration through a depth filter.   The method according to claim 7, wherein preliminary filtration is performed using a filter medium having an opening size of 50 to 100 μm.   The method according to claim 1, wherein the resin is a thermoplastic resin.   The method according to claim 9, wherein the thermoplastic resin comprises a thermoplastic polymer containing ethylene and / or propylene. The thermoplastic resin is a structural unit derived from ethylene and / or propylene, and the formula (I)
_{CH 2 = CH-R (I} )
(In the formula, R represents a secondary alkyl group, a tertiary alkyl group, or an alicyclic carbocyclic group.)
An olefin copolymer containing a structural unit derived from the vinyl compound (I) represented by the formula (1), or a polymer obtained by graft polymerization of an α, β-unsaturated carboxylic acid anhydride to the olefin copolymer. 11. A method according to claim 9 or 10 comprising.   The production method according to claim 11, wherein the structural unit derived from the vinyl compound (I) comprises a structural unit derived from vinylcyclohexane.   The method of any one of Claims 9-12 whose MFR (190 degreeC, 2.16kgf) of a thermoplastic resin is 130 g / 10min or more and 300 g / 10min or less. a structural unit derived from an α, β-unsaturated carboxylic acid (1);
A structural unit derived from an α, β-unsaturated carboxylic acid ester (2) containing a C 1-10 alkyl group having a hydroxyl group bonded to a methylene group or a methine group and an α, β-unsaturated carboxylic acid; The method of any one of Claims 9-13 using the acrylic resin (B) which contains as an emulsifier.   The structural unit derived from the α, β-unsaturated carboxylic acid (1) is a structural unit derived from at least one α, β-unsaturated carboxylic acid selected from the group consisting of acrylic acid and methacrylic acid. The method according to claim 14.   The method according to claim 14 or 15, wherein the α, β-unsaturated carboxylic acid ester (2) is an ester of an α, ω-alkylenediol and an α, β-unsaturated carboxylic acid.   The method according to any one of claims 1 to 16, wherein the volume-based median diameter of the dispersoid in the emulsion before the filtration step is 0.5 to 1.5 µm.   The method according to any one of claims 1 to 17, wherein the coarse particle size of the dispersoid in the emulsion before the filtration step is 30 to 200 µm.   The method of any one of Claims 1-18 that the coarse particle diameter of the dispersoid in the aqueous | water-based emulsion after a filtration process is 1-30 micrometers.   The aqueous emulsion manufactured by the method of any one of Claims 1-19.   A method for forming a coating film on a substrate, wherein the aqueous emulsion according to claim 20 is coated on a substrate and heated.   A coating film obtained by applying the aqueous emulsion according to claim 20 and drying the emulsion.   23. A base material comprising at least one material selected from the group consisting of a woody material, a cellulosic material, a plastic material, a ceramic material, and a metal material, and the coating film according to claim 22. A laminate characterized by the following. Applying the aqueous emulsion according to claim 20 to a substrate comprising at least one material selected from the group consisting of a woody material, a cellulosic material, a plastic material, a ceramic material, and a metal material, A first step of obtaining a coated product comprising a substrate and a layer comprising the aqueous emulsion;
A second step of drying the coated product obtained in the first step to obtain a laminate comprising the base material and a coating film derived from the aqueous emulsion. Production method.