JP5208003B2 - Polymer fine particle dispersion composition and method for producing the same - Google Patents

Description

  The present invention relates to a polymer fine particle dispersion composition, and more specifically, to a polymer fine particle dispersion composition having a volume average particle diameter of 50 nm or less and polymer fine particles containing a crosslinked polymer layer are dispersed independently in a medium. .

  Thermosetting resins typified by epoxy resins, unsaturated polyester resins, polyimides, phenol resins, and the like are widely used in various fields because of their excellent heat resistance, mechanical strength, dimensional accuracy, and the like. In addition, thermoplastic resins represented by acrylic resins, styrene resins, saturated polyester resins, polycarbonate resins and the like are excellent in moldability and the like, and thus are widely used in various fields. In order to improve the impact resistance of these resins, it is generally practiced to blend rubber-like polymer particles having a volume average particle diameter of 50 nm to 200 nm.

  On the other hand, a cured product of epoxy resin, which is a representative thermosetting resin, is excellent in many respects such as mechanical strength, electrical insulation properties, heat resistance, etc., but the cured product has low fracture toughness and is extremely May exhibit brittle properties, and such properties are often problematic in a wide range of applications. Similarly, resins having improved toughness as well as impact resistance have recently been desired.

  For this reason, for example, a rubber component is conventionally added to an epoxy resin. Among them, a method of blending rubbery polymer particles prepared in advance into particles using a polymerization method in an aqueous medium typified by emulsion polymerization, dispersion polymerization, and suspension polymerization is, for example, non-epoxy resin. Compared with a method in which a dispersed phase of a rubber component is generated in a continuous phase of an epoxy resin cured product by causing phase separation in the curing process after dissolving and mixing the crosslinked rubber component, in principle, dispersion by compounding curing conditions Various advantages can be considered, such as being less likely to cause state fluctuations, and pre-crosslinking the rubber component so that the rubber component is not mixed into the epoxy resin cured product continuous phase and heat resistance and rigidity are less deteriorated. .

  For this reason, in Patent Document 1, the epoxy resin is mixed with a rubber-like polymer latex in the presence of an organic solvent to obtain a mixture, and then the moisture is removed and cured to break the epoxy resin. A method for improving energy is described. In this case, the particle size of the rubber-like polymer is 20 μm or less, preferably 30 nm to 2000 nm, more preferably 90 nm to 150 nm. Is in the range of 100 nm to 1200 nm.

  However, with this method, when mixing the rubber-like polymer latex and the epoxy resin, a large amount of water (more than the amount of water that the organic solvent can dissolve) present in the system (in the mixture) with the organic solvent is separated. Alternatively, the organic solvent layer and the aqueous layer need to be separated from the organic solvent layer and the aqueous layer for a long time, such as one day and night, or the organic solvent layer and the aqueous layer form a stable emulsified suspension state. However, the separation becomes substantially difficult. In addition, when distilling off water, a large amount of energy is required, and water-soluble impurities such as emulsifiers and auxiliary materials usually used in the production of rubber-like polymer latex remain in the composition. The quality is inferior. For this reason, water removal is complicated by either separation or distillation, which is not industrially preferable. Moreover, it does not describe about the rigidity of the epoxy resin obtained by this method.

  Patent Document 2 discloses that a rubber-like polymer having a particle size of 300 nm or less is mixed with an organic solvent and a polymerizable organic compound such as an epoxy resin, and a volatile component is distilled off to remove rubber. A method of obtaining a resin composition in which the polymer particles are well dispersed and having a small amount of impurities is described. At this time, the organic solvent in which the rubber-like polymer is well dispersed is used as the rubber-like polymer particles. A mixture obtained by mixing an aqueous latex with an organic solvent having partial solubility in water is brought into contact with water to form aggregates of rubber-like polymer particles, and a mixture of aggregates and an aqueous phase. It is obtained by separating an aqueous phase to obtain an aggregate of rubber-like polymer particles with less impurities, and then adding an organic solvent to the aggregate. At this time, the preferable particle size of the rubber-like polymer is 50 nm to 300 nm, and the particle size actually used is 100 nm as the particle size of the rubber particles. However, this Patent Document 2 does not report the result that the toughness has actually been improved, and does not describe the rigidity.

  Patent Document 3 discloses an epoxy resin composition for a semiconductor encapsulant comprising an epoxy resin and a rubbery polymer, wherein at least 70% of the rubbery polymer is in a resin phase containing the epoxy resin. Are dispersed in the form of primary particles and the composition (the epoxy resin composition for a semiconductor encapsulating material in which the alkali metal ion content is 30 ppm or less is described. The preferred volume average particle size is 30 nm to 2000 nm, and the actual particle size used is 100 nm as the particle size of the rubber particles, but this Patent Document 3 shows the result of actually improving toughness. Is not listed.

US Pat. No. 4,778,851 International Publication WO2005 / 028546 Pamphlet International Publication WO2006 / 019041 Pamphlet

  The present invention has been made in view of the above problems, and the object of the present invention is excellent in toughness, impact resistance, and elastic modulus (rigidity), and becomes a new resin modification means that balances these. It is to provide a resulting fine polymer particle dispersion composition and to provide a method for producing such a fine polymer particle dispersion composition.

  As a result of intensive studies, the present inventor has made such a polymer fine particle dispersion composition having a specific configuration, contrary to the expectation from the widely recognized theory. The inventors have found the surprising result that the fracture toughness can be improved without decreasing the elastic modulus (rigidity / hardness) of the obtained cured product or polymer, and the present invention has been completed. Moreover, the manufacturing method of the polymer fine particle dispersion composition which has such a specific structure of this invention was also discovered simultaneously.

That is, the polymer fine particle dispersion composition of the present invention is a polymer fine particle dispersion composition comprising 100 parts by weight of a medium mainly composed of components other than water and 0.1 part by weight to 150 parts by weight of polymer fine particles,
The polymer fine particle has a volume average particle diameter of 50 nm or less and includes a crosslinked polymer layer,
The polymer fine particle dispersion composition is characterized in that the polymer fine particles are independently dispersed in the medium.

  A preferred embodiment is that the crosslinked polymer layer is a crosslinked rubbery polymer having a Tg of 0 ° C. or less.

  In a preferred embodiment, the crosslinked rubber-like polymer is at least one selected from the group consisting of a diene rubber polymer, an acrylic rubber polymer, and an organosiloxane rubber polymer.

  In a preferred embodiment, the polymer fine particles are polymer fine particles including at least two layers of the cross-linked polymer layer existing on the inner side and the coating polymer layer existing on the outermost side.

  In a preferred embodiment, the coating polymer layer is formed of a coating polymer layer polymer obtained by polymerizing a coating polymer layer component containing a monomer having a polymerizable or curing reactive functional group, and , A functional group having the polymerizable or curing reactivity is an epoxy group, an oxetane group, a hydroxyl group, a carbon-carbon double bond, an amino group, an imide group, a carboxylic acid group, a carboxylic acid anhydride group, a cyclic ester, One or more selected from the group consisting of a cyclic amide, a benzoxazine group, and a cyanate ester group.

In a preferred embodiment, the polymer fine particles further include an intermediate polymer layer that is in contact with the cross-linked polymer layer and is present outside thereof, and
The intermediate polymer layer is made of an intermediate polymer layer polymer obtained by polymerizing an intermediate polymer layer component composed of 30 to 100% by weight of a polyfunctional monomer and 0 to 70% by weight of another vinyl monomer. .

  In one preferred embodiment, the medium is at least one selected from the group consisting of a cured curable or polymerizable monomer, a cured curable or polymerizable oligomer, and a thermoplastic polymer. And a medium that is solid at room temperature.

  In another preferred embodiment, the medium is at least one selected from the group consisting of a curable or polymerizable monomer, a curable or polymerizable oligomer, and an organic solvent, and is a liquid that is liquid at room temperature. It is to do.

  A preferred embodiment is that the curable or polymerizable monomer or the curable or polymerizable oligomer is an organic compound containing a functional group having a polymerizable or curing reactivity.

  In a preferred embodiment, the polymerizable or curing reactive functional group is an epoxy group, an oxetane group, a hydroxyl group, a carbon-carbon double bond, an amino group, an imide group, a carboxylic acid group, or a carboxylic anhydride group. And at least one selected from the group consisting of cyclic esters, cyclic amides, benzoxazine groups, and cyanate ester groups.

Further, the present invention is a method for producing the polymer fine particle dispersion composition of the present invention, in order,
An aqueous medium dispersion in which the polymer fine particles are dispersed in an aqueous medium is mixed with an organic solvent having a solubility in water at 20 ° C. of 5% by mass to 40% by mass, and further mixed with excess water. A first step of obtaining a polymer fine particle loose aggregate of polymer fine particles;
A second step of separating and collecting the agglomerated polymer fine particles from the liquid phase and then mixing with the organic solvent again to obtain a polymer fine particle dispersion;
A third step of further distilling the organic solvent after further mixing the organic solvent solution with the medium;
The present invention relates to a method for producing a polymer fine particle dispersion composition.

  In a preferred embodiment, the aqueous medium dispersion is prepared by using at least one monomer selected from the group consisting of emulsion polymerization, suspension polymerization, miniemulsion polymerization, microemulsion polymerization, and dispersion polymerization in the aqueous medium. A water-based latex formed by polymerizing the polymer particles using a method.

  In the fine polymer particle dispersion composition of the present invention, fine polymer particles having a specific configuration are dispersed in a medium in a specific state. By processing, even in a cured product or polymer that is solid at room temperature, the polymer fine particles can maintain an independently dispersed state in the medium, thereby reducing the rigidity and elastic modulus of the cured product and polymer, The toughness of the polymer fine particle-dispersed resin composition can be greatly improved as compared with the prior art, and thus a cured product or polymer having an excellent balance between rigidity and toughness can be obtained.

  Applying such a polymer fine particle dispersion composition of the present invention to a curable resin such as an epoxy resin serving as a base for a matrix resin or a structural adhesive of a next-generation structural material typified by a carbon fiber composite material In particular, it is an excellent reforming technique that can greatly improve its toughness without impairing its rigidity.

Transmission electron micrograph of the cured plate of Example 2

(Polymer fine particle dispersion composition)
The polymer fine particle dispersion composition of the present invention is a polymer fine particle dispersion composition comprising 100 parts by weight of a medium and 0.1 part by weight to 150 parts by weight of the polymer fine particles, wherein the polymer fine particles have a volume average particle diameter of 50 nm. And a polymer fine particle dispersion composition comprising a cross-linked polymer layer, wherein the polymer fine particles are independently dispersed in the medium. When the medium is a cured product or a polymer, A polymer fine particle-dispersed resin composition capable of imparting toughness to the medium and thus improving toughness can be obtained. That is, according to the present invention, when the medium of the polymer fine particle dispersed resin composition of the present invention is a cured product or a polymer, the polymer fine particle dispersed composition according to the present invention is independently dispersed in the room temperature solid medium. It was discovered that the toughness of the solid medium was improved and was based on the discovery.

  As described above, in the state where the improved toughness is exhibited, the medium according to the present invention is preferably a solid curable or polymerizable monomer, curable or polymerizable oligomer at room temperature. It is 1 or more types chosen from the group which consists of what hardened | cured and thermoplastic polymer. In addition, the polymer fine particle dispersion composition according to a preferred embodiment of the present invention, in which polymer fine particles are independently dispersed in a solid medium, is preferably selected from a curable or polymerizable monomer that is liquid at room temperature and an organic solvent. It is obtained through the polymer fine particle dispersion composition of another preferred embodiment of the present invention using one or more kinds as a medium.

  Such a polymer fine particle dispersion composition of the present invention is used as a polymerizable or curable resin such as an epoxy resin as a base for a matrix resin or a structural adhesive of a next-generation structural material represented by a carbon fiber composite material. It is particularly preferable to apply, and unlike the conventional reforming technique, it is an excellent reforming technique that can greatly improve its toughness without impairing its characteristics such as rigidity and heat resistance.

  As described above, the polymer fine particle dispersion composition of the present invention needs to contain 0.1 to 150 parts by weight of the polymer fine particles with respect to 100 parts by weight of the medium. From the standpoint of the independent dispersibility and the cost, it is preferably 1 to 100 parts by weight, more preferably 2 to 50 parts by weight.

  As described above, the polymer fine particle dispersion composition of the present invention requires that the polymer fine particles are independently dispersed in the medium. In this specification, the polymer fine particles are “independently dispersed” This means that polymer fine particles having a weight average particle diameter of 50 nm or less do not aggregate with each other in the medium and are dispersed independently. Specifically, the following formula (Formula 1) is used. It means that the calculated particle dispersion ratio (%) is 50% or more. Such a particle dispersion rate is preferably 75% or more, more preferably 90% or more, from the viewpoint of improving the toughness.

Here, the sum B ₀ of the number of individual polymer particles in the measurement sample and the number of lumps in contact with two or more polymer particles, and the number B of lumps in contact with two or more polymer particles. ₁ is calculated and calculated according to the above formula (Formula 1). Here, a sample whose B ₀ is at least 10 or more and an observation region are selected.

  As described above, since the polymer fine particles according to the present invention are dispersed independently in the medium, the effect of improving the toughness is exhibited. It is necessary to include. Further, from the viewpoint of imparting toughness, the polymer fine particles according to the present invention require a volume average particle diameter of 50 nm or less, preferably 1 nm or more and 30 nm or less, preferably 5 nm or more and 20 nm or less. It is more preferable. Further, as the particle size distribution, the ratio of polymer fine particles having a particle size of 25 nm or less is preferably 70% or more, more preferably 90% or more. The volume average particle diameter of such polymer fine particles can be determined using Microtrac UPA150 (manufactured by Nikkiso Co., Ltd.).

  In such a polymer fine particle dispersion composition of the present invention, an aqueous medium dispersion in which polymer fine particles are dispersed in an aqueous medium in turn is an organic solvent having a solubility in water at 20 ° C. of 5% by mass to 40% by mass. After mixing with an excess of water, the first step of slowly aggregating the polymer fine particles to obtain a polymer fine particle agglomerate, and separating and recovering the polymer fine particle agglomerates from the liquid phase, A second step of obtaining a polymer fine particle dispersion in which polymer fine particles are dispersed in the organic solvent for dispersion by mixing with an organic solvent for dispersion; and further mixing the polymer fine particle dispersion with the medium, and then the organic solvent for dispersion. And a third step of obtaining the polymer fine particle dispersion composition of the present invention by distilling off the solvent. By such a method, a polymer fine particle dispersion composition in which polymer fine particles are independently dispersed (hereinafter also referred to as primary dispersion) can be easily obtained, and such a production method of the present invention is excellent in handling properties. . That is, such a method for producing a polymer fine particle dispersion composition of the present invention is excellent in that extremely small cross-linked polymer particles having a particle diameter of 50 nm or less, particularly 20 nm or less, are obtained on any solid or liquid organic medium. This is a simple method for producing a polymer fine particle dispersion composition which is dispersed.

  In the method for producing a polymer fine particle dispersion composition of the present invention described above, the aqueous medium dispersion preferably comprises a monomer in the aqueous medium, emulsion polymerization, suspension polymerization, miniemulsion polymerization, microemulsion polymerization, And an aqueous latex formed by polymerizing the polymer particles using one or more methods selected from the group consisting of dispersion polymerization.

  In such a polymer fine particle dispersion composition of the present invention, an antioxidant, an ultraviolet absorber, an inorganic filler, a dye, a pigment, a diluent, a coupling agent, a resin other than the resin mentioned as a preferable medium described later, and the like. The medium can be blended as necessary as long as the original mechanical strength and toughness of the medium are not impaired.

(Medium)
As described above, the medium according to the present invention is a cured product, a polymer, or a medium that can be replaced while maintaining the independent dispersion state of the polymer fine particles in the cured product or the polymer. From the viewpoint of ensuring an independent dispersion state, an organic compound is preferable. It is a medium mainly composed of components other than water from the viewpoint that it can be easily applied to the purpose of modifying a cured product or a polymer while suppressing irreversible aggregation of the polymer fine particles and maintaining an independent dispersion state, preferably A medium mainly composed of an organic compound.

  Examples of the organic compound that can be used as the medium according to the present invention include a curable or polymerizable monomer, a curable or polymerizable oligomer, a resin obtained by curing these, a thermoplastic polymer, and various organic solvents. 1 or more types chosen from these, and these mixtures are illustrated preferably.

  When the medium is at least one selected from the group consisting of a curable or polymerizable monomer, a curable or polymerizable oligomer, and an organic solvent, and is liquid at room temperature, the polymer fine particle dispersion of the present invention Since the cured product with significantly improved rigidity and toughness can be obtained in various shapes by curing or polymerizing the composition as it is or after appropriately diluting with any polymerizable or curable resin, in particular, various shapes can be obtained. preferable.

  The curable or polymerizable monomer or oligomer is preferably an organic compound containing a functional group having a polymerizable or curing reactivity, and the functional group having a polymerizable or curing reactivity is an epoxy. Selected from the group consisting of groups, oxetane groups, hydroxyl groups, carbon-carbon double bonds, amino groups, imide groups, carboxylic acid groups, carboxylic anhydride groups, cyclic esters, cyclic amides, benzoxazine groups, and cyanate ester groups One or more selected from the above and mixtures thereof are preferred. Among these, an epoxy group, an oxetane group, a phenolic hydroxyl group, a cyclic ester, a cyanate ester group, a benzoxazine group, and a compound having a carbon-carbon double bond are polymerizable, from the viewpoint of utility value as a curable resin. More preferably, a so-called epoxy resin having an epoxy group is particularly preferable. Epoxy resins include bisphenol compounds, hydrogenated bisphenol compounds, phenols or o-cresol novolaks, glycidyl ether substitutions of known basic skeleton compounds such as aromatic amines, polycyclic aliphatic or aromatic compounds, and cyclohexene oxide skeletons. A typical example is a diglycidyl ether of bisphenol A and its condensate, a so-called bisphenol A type epoxy resin.

  Preferred examples of the thermoplastic polymer include acrylic resins, styrene resins, saturated polyester resins, and polycarbonate resins.

  Examples of the organic solvent include ketones such as methyl ethyl ketone, esters such as methyl formate, methyl acetate and ethyl acetate, ethers such as diethyl ether, ethylene glycol diethyl ether and tetrahydropyran, acetals such as methylal, isobutyl alcohol, sec -Alcohols, such as butyl alcohol, are illustrated preferably.

  The polymer fine particle dispersion composition of the present invention comprises a molding material, an adhesive, a fiber or filler reinforced composite material, a sealing material, a casting material, an insulating material, a coating material, a filler, a photomolding material, an optical component, an ink, and a toner. Is preferably used.

  In the case where the medium is a curable or polymerizable monomer, the polymer fine particle dispersion composition of the present invention is, for example, a curing agent, a catalyst, an action of heat, light (such as ultraviolet rays) or radiation (such as an electron beam), and these The polymer fine particle dispersion composition of the present invention is cured by a known curing method such as a combination. When molding in this case, for example, transfer molding method, injection molding method, casting molding method, coating baking method, rotational molding method, photo-molding method, and hand lay-up molding combined with carbon fiber, glass fiber, etc. Methods, prepreg molding methods, pultrusion molding methods, filament winding molding methods, press molding methods, resin transfer molding (RTM, VaRTM) molding methods, SMC molding methods, and the like, but are not limited thereto.

(Polymer fine particles)
The polymer fine particles according to the present invention need to include a crosslinked polymer layer. However, as described above, the polymer fine particles themselves are composed of only the crosslinked polymer layer because they are independently dispersed without being compatible with the medium. In other words, the crosslinked polymer layer is a main component of the polymer fine particle according to the present invention, including the case where 100% by weight of the polymer fine particle is a crosslinked polymer layer, and from the viewpoint of the toughness improving effect of the present invention. The ratio is preferably 40% by weight or more, more preferably 45% to 90% by weight. From the viewpoint of improving toughness, it is preferable to include one particulate crosslinked polymer layer inside one polymer fine particle, in which case the preferred number average particle diameter of the crosslinked polymer layer is 50 nm or less, More preferably, they are 1 nm or more and 30 nm or less, More preferably, they are 2 nm or more and 20 nm or less.

  Moreover, it is preferable that the polymer fine particles according to the present invention further have a coating polymer layer on the outermost side from the viewpoint of improving dispersibility in the medium. Such a structure composed of the inner cross-linked polymer layer and the outermost coated polymer layer is referred to as a core / shell structure. Therefore, hereinafter, the cross-linked polymer layer is also referred to as a core layer, and the coated polymer layer is also referred to as a shell layer. There is. Such a coated polymer layer is preferably 50% by weight or less, more preferably 10% by weight to 45% from the viewpoint of improving dispersibility while sufficiently exhibiting the toughness improvement effect with 100% by weight of polymer fine particles. % By weight. Further, from the viewpoint of improving toughness, the coated polymer layer is preferably present on the outermost side of the polymer fine particles with an average thickness of 10 nm or less, and from the viewpoint of improving dispersibility, the average thickness is more preferably 2 nm to 8 nm. preferable.

  Further, the polymer fine particles according to the present invention prevent elution into the medium over a long period of time, increase the toughness-imparting effect of the present invention, and make the coated polymer layer uniformly exist on the outer surface of the polymer fine particles. From one or more viewpoints, it is preferable to further have an intermediate polymer layer in contact with the cross-linked polymer layer on the outer side and on the inner side of the covering polymer layer. Such an intermediate polymer layer is preferably 20% by weight or less, more preferably 5% by weight to 10% by weight, based on 100% by weight of the polymer fine particles, from the above viewpoint.

(Crosslinked polymer layer)
The crosslinked polymer layer according to the present invention is an effect found by the inventors of the present invention, which is an effect of improving the toughness of a cured product or polymer containing polymer finely dispersed particles whose volume average particle diameter is 50 nm or less. If it is played, it will not specifically limit, For example, a crosslinked rubber-like polymer, a crosslinked hard polymer, etc. are illustrated preferably.

  When the crosslinked rubber-like polymer is used as the crosslinked polymer layer, it is particularly preferable since an impact resistance improving effect can be imparted to the cured product or polymer in addition to the toughness improving effect of the present invention. Such a crosslinked rubber-like polymer is preferably a crosslinked rubber-like polymer having a Tg of 0 ° C. or less from the viewpoint of impact resistance improving effect, and is a diene rubber polymer, an acrylic rubber polymer, an organosiloxane type. Examples include rubber polymers, polyolefin rubbers obtained by polymerizing olefin compounds, aliphatic polyesters such as polycaprolactone, polyethers such as polyethylene glycol and polypropylene glycol, and in particular, from the viewpoint of easily obtaining a crosslinked polymer dispersion in an aqueous system. A diene rubber polymer, an acrylic rubber polymer, and an organosiloxane rubber polymer are more preferable, and an acrylic rubber polymer is particularly preferable from the viewpoint of easy polymerization in an aqueous system.

  The method for introducing such a crosslinked structure is not particularly limited, and a generally used technique can be employed. For example, when a monomer is polymerized to polymerize the above-described diene rubber polymer, acrylic rubber polymer, etc., a diene monomer as a main component thereof, a polyfunctional monomer or mercapto described later on the acrylic monomer, and the like. Examples thereof include a method in which a crosslinkable monomer such as a group-containing compound is added and then polymerized. In addition, as a method for introducing a crosslinked structure into the organosiloxane rubber polymer, a method in which a polyfunctional alkoxysilane compound is partially used at the time of polymerization, or a reactive group such as a vinyl reactive group or a mercapto group is added to a polysiloxane. Introduce into vinyl polymer and then add vinyl polymerizable monomer or organic peroxide to cause radical reaction, or add cross-linkable monomer such as polyfunctional vinyl compound or mercapto group-containing compound to polysiloxane polymer And then polymerizing.

  Specifically, the crosslinked rubber-like polymer preferably has a gel content of 70% by mass or more, more preferably 90% by mass or more, and particularly preferably 95% by mass or more. In addition, the gel content referred to in the present specification means that 0.5 g of crumb obtained by coagulation and drying is immersed in 100 g of toluene and left to stand at 23 ° C. for 24 hours, and then insoluble and soluble components are separated. The ratio of insoluble matter to the total amount of insoluble matter and soluble matter is meant.

(Coating polymer layer)
The coated polymer layer according to the present invention comprises a coated polymer layer polymer obtained by polymerizing the coated polymer layer components, and has an effect of improving the dispersibility of the polymer fine particles according to the present invention in the medium. There is no particular limitation, for example, vinyl polymers obtained by radical polymerization of vinyl monomers having vinyl groups, polyolefins obtained by polymerizing olefin compounds, silicone polymers obtained by condensation polymerization of siloxane compounds, and aliphatic polyesters such as polycaprolactone. Preferred examples include polyethers such as polyethylene glycol and polypropylene glycol. Among these, when the vinyl polymer is used as the covering polymer layer, it is preferable because it can be graft-polymerized to the crosslinked polymer layer or an intermediate polymer layer described later.

  In this case, from the viewpoint of chemically bonding to the liquid or solid matrix resin in order to maintain a good dispersion state without aggregation of the polymer fine particles according to the present invention in the cured product or polymer, the vinyl In addition to the vinyl group that forms the main chain of the polymer, an epoxy group, an oxetane group, a hydroxyl group, a carbon-carbon double bond, an amino group, an imide group, a carboxylic acid group, a carboxylic anhydride group, a cyclic ester, a cyclic amide, A reactive group-containing vinyl monomer containing at least one selected from the group consisting of a benzoxazine group and a cyanate ester group is 0.1 wt% to 50 wt% when the coating polymer layer component is 100 wt%. % Content is more preferable.

  For example, from the viewpoint of maintaining a good dispersion state without aggregation of polymer fine particles when the medium is an epoxy resin, the coated polymer layer polymer is made of styrene (St), acrylonitrile (AN) as the main chain-forming vinyl monomer. ) And methyl methacrylate (MMA) as main components, and the reactive group-containing vinyl monomer is preferably a copolymer having glycidyl methacrylate (GMA) as a main component.

  Moreover, when the coating polymer layer polymer is a copolymer obtained by polymerizing a coating polymer layer component containing a polyfunctional monomer described later, the effect obtained by inserting the intermediate layer polymer layer described later is exhibited in the coating polymer layer. Since it may be possible, it is more preferable.

(Intermediate polymer layer)
The intermediate polymer layer according to the present invention comprises 30 to 100% by weight of a monomer having two or more radical double bonds in the same molecule (hereinafter sometimes referred to as “polyfunctional monomer”), and other vinyl monomers. An intermediate polymer layer polymer obtained by polymerizing an intermediate polymer layer component consisting of 0 to 70% by weight, the effect of reducing the viscosity of the polymer fine particle dispersion composition of the present invention, and the coating polymer layer uniformly on the outer wall surface of the polymer fine particles As long as it has any one of the effect of improving the dispersibility of the polymer fine particles in the medium, it is not particularly limited. By having an intermediate polymer layer formed mainly of such a polyfunctional monomer, the intermediate polymer layer component is grafted to the coating polymer layer through one of the double bonds of the polyfunctional monomer. By polymerization, the intermediate polymer layer and the coating polymer layer are chemically bonded to each other and graft polymerized to the cross-linked polymer layer through the remaining double bonds, so that the intermediate polymer layer and the cross-linked polymer layer substantially Chemically bond. In other words, since many double bonds are arranged in the core, the grafting efficiency of the shell is increased and the crosslink density of the core of the polymer fine particles is increased, so that the above three effects are easily obtained.

(Method for producing polymer fine particles)
The polymer fine particles according to the present invention have a volume average particle diameter of 50 nm or less and include a crosslinked polymer layer. Such polymer fine particles can be formed by a well-known method, but since they can be produced in a general aqueous medium, the monomer is emulsion polymerization, suspension polymerization, miniemulsion polymerization, microemulsion in the aqueous medium. Polymerization is preferably performed using one or more methods selected from the group consisting of emulsion polymerization and dispersion polymerization. The polymer fine particles according to the present invention, which is an aqueous latex formed in this manner, are dispersed in an aqueous medium. It is preferable to produce the polymer fine particle dispersion composition of the present invention using the aqueous medium dispersion as a starting material. Among the polymerization methods, emulsion polymerization, particularly multistage emulsion polymerization is preferable from the viewpoint of controlling the structure of the polymer fine particles.

  As the emulsifier (dispersant) that can be used in the emulsion polymerization, alkyl or aryl sulfonic acid represented by dioctyl sulfosuccinic acid or dodecylbenzene sulfonic acid, alkyl or aryl ether sulfonic acid, alkyl represented by dodecyl sulfate, or Aryl sulfuric acid, alkyl or aryl ether sulfuric acid, alkyl or aryl substituted phosphoric acid, alkyl or aryl ether substituted phosphoric acid, N-alkyl typified by dodecyl sarcosine acid, alkyl typified by oleic acid, stearic acid, etc. Or various acids such as aryl carboxylic acids, alkyl or aryl ether carboxylic acids, anionic emulsifiers (dispersing agents) such as alkali metal salts or ammonium salts of these acids; alkyl or aryl Nonionic emulsifiers such as substituted polyethylene glycol (dispersing agent); polyvinyl alcohol, alkyl substituted cellulose, polyvinyl pyrrolidone, dispersants such as polyacrylic acid derivatives. These emulsifiers (dispersants) may be used alone or in combination of two or more.

  The amount of emulsifier (dispersant) used is preferably reduced as long as the dispersion stability of the aqueous latex of polymer fine particles is not hindered. Moreover, an emulsifier (dispersant) is so preferable that the water solubility is high. When the water solubility is high, the emulsifier (dispersant) can be easily removed by washing with water, and adverse effects on the finally obtained polycondensate can be easily prevented.

(Diene rubber polymer)
The diene rubber polymer is a polymer that is polymerized with a diene monomer as a main component, and can be a copolymer that is polymerized by appropriately mixing other vinyl monomers.

  Examples of the diene monomer (conjugated diene monomer) include 1,3-butadiene, isoprene, 2-chloro-1,3-butadiene, 2-methyl-1,3-butadiene, and the like. These diene monomers may be used alone or in combination of two or more. Particularly preferred is 1,3-butadiene.

(Acrylic rubber polymer)
The acrylic rubber polymer is a polymer that is polymerized with an acrylic monomer as a main component, and may be a copolymer obtained by mixing other (meth) acrylic monomers and the other vinyl monomers as appropriate. it can.

  As the acrylic monomer, at least one selected from ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, and 2-phenoxyethyl acrylate is excellent in impact resistance improvement effect because of its large rubber elasticity. Of these, butyl acrylate (BA) and 2-ethylhexyl acrylate (2-EHA) are particularly preferable.

Examples of the (meth) acrylic monomer include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, and stearyl. Alkyl (meth) acrylates such as (meth) acrylate and behenyl (meth) acrylate;
Hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate;
Glycidyl (meth) acrylates such as glycidyl (meth) acrylate and glycidyl alkyl (meth) acrylate;
Alkoxyalkyl (meth) acrylates;
Allylalkyl (meth) acrylates such as allyl (meth) acrylate and allylalkyl (meth) acrylate;
Examples include polyfunctional (meth) acrylates such as monoethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and tetraethylene glycol di (meth) acrylate. These (meth) acrylates may be used alone or in combination of two or more.

  In the present specification, (meth) acrylate means acrylate and / or methacrylate.

  The rubber elastic body that can constitute the elastic core layer may be a copolymer of the first monomer and the vinyl monomer (second monomer). Examples of vinyl monomers include vinyl arenes such as styrene, α-methylstyrene, monochlorostyrene, dichlorostyrene; vinyl carboxylic acids such as acrylic acid and methacrylic acid; vinyl cyanides such as acrylonitrile and methacrylonitrile; vinyl chloride Vinyl acetate; vinyl acetate; alkenes such as ethylene, propylene, butylene, and isobutylene; polyfunctional monomers such as diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, and divinylbenzene Is mentioned. These vinyl monomers may be used alone or in combination of two or more. Particularly preferred is styrene.

(Organosiloxane rubber polymer)
Preferred examples of the organosiloxane rubber polymer include polysiloxane polymers composed of alkyl or aryl disubstituted silyloxy units such as dimethylsilyloxy, diethylsilyloxy, methylphenylsilyloxy, diphenylsilyloxy and the like. Specifically, a cyclic siloxane represented by 1,3,5,7-octamethylcyclotetrasiloxane (D4), and preferably a linear or branched chain having a weight average molecular weight of 500 to 20,000 or less. A monomer for forming an organosiloxane rubber polymer composed mainly of an organosiloxane oligomer, using a catalyst such as acid, alkali, salt, or fluorine compound, solution polymerization method, suspension polymerization method, emulsion polymerization method Preferably, the polyorganosiloxane particles polymerized by the above method are exemplified. Kill.

  In addition, 100% by weight of the monomer for forming the organosiloxane rubber polymer includes tri- or higher functional alkoxysilanes such as methyltriethoxysilane and tetrapropyloxysilane, and methyl ortho from the viewpoint of forming a crosslinked structure. One or more selected from the group consisting of tri- or higher functional silane condensates such as silicate is preferably contained in an amount of 0 to 20% by weight.

  Further, in 100% by weight of the monomer for forming the organosiloxane rubber polymer, an allyl substituent is introduced into the organosiloxane rubber polymer so that the coating with the coating polymer layer according to the present invention can be easily performed. From the viewpoint of, it contains a bifunctional hydrolyzable group such as mercaptopropyldimethoxymethylsilane, acryloyloxypropyldimethoxymethylsilane, methacryloyloxypropyldimethoxymethylsilane, vinyldimethoxymethylsilane, vinylphenyldimethoxymethylsilane, and vinyl group. It is preferable that the graft crossing agent which is a silane compound is contained in an amount of 0 to 50% by weight.

(Multifunctional monomer)
As the polyfunctional monomer, butadiene is not included, and allyl alkyl (meth) acrylates such as allyl (meth) acrylate and allylalkyl (meth) acrylate; ethylene glycol di (meth) acrylate, 1,3-butanediol di Multifunctional (meth) acrylates such as (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate; diallyl phthalate, triallyl cyanurate, tri Examples include allyl isocyanurate (TAIC), glycidyl diallyl isocyanurate, and divinylbenzene. Particularly preferred are allyl methacrylate, triallyl isocyanurate, and divinylbenzene (DVB).

  Preferred for crosslinking of the crosslinked polymer layer are allyl methacrylate (AlMA), TAIC and diallyl phthalate from the viewpoint of availability, ease of polymerization, and high graft efficiency of the intermediate polymer layer or coating polymer layer.

  As the main component of the intermediate polymer layer component, AlMA, TAIC, 1,3-butanediol di (meth) acrylate, and DVB are particularly preferable from the viewpoint of viscosity reduction and availability of the fine particle polymer dispersion and ease of polymerization. .

(Other vinyl monomers)
Examples of the other vinyl monomers include vinyl monomers that are not any of the above-described diene monomers, (meth) acrylic monomers, and multifunctional monomers, and include, for example, styrene, α-methylstyrene, 1- or 2-vinyl. Vinyl aromatic compounds such as naphthalene, monochlorostyrene, dichlorostyrene, bromostyrene; alkenes such as ethylene, propylene, butylene, isobutylene; vinyl cyanide compounds represented by (meth) acrylonitrile; (meth) acrylamide, alkyl vinyl ether These other vinyl monomers may be used alone or in combination of two or more.

(Preparation method of polymer fine particle dispersion composition of the present invention)
As described above, the method for producing the polymer fine particle dispersion composition of the present invention comprises, in order, the first step of obtaining a polymer fine particle aggregate, the second step of obtaining a polymer fine particle dispersion, and the polymer fine particle dispersion composition of the present invention. It is preferable to prepare including the 3rd process of obtaining.

(First step: Preparation of polymer fine particle agglomerates)
The first step includes an operation of mixing an organic solvent having a solubility in water at 20 ° C. of preferably 5% by mass or less and 40% by mass or less (particularly 30% by mass or less) with the aqueous medium dispersion. By using such an organic solvent, after the above mixing operation, when water is further added, phase separation occurs (to be described later), thereby obtaining a polymer aggregate slow aggregate that is loose enough to be redispersed. Can do.

  When the solubility of the organic solvent is less than 5% by mass, mixing with the aqueous medium dispersion containing polymer fine particles may be somewhat difficult. When the solubility exceeds 40% by mass, it may be difficult to separate and recover the polymer fine particles (described later) from the liquid phase (mainly the aqueous phase) in the second step.

  Examples of the organic solvent having a solubility in water at 20 ° C. of 5% by mass or more and 40% by mass or less include ketones such as methyl ethyl ketone, esters such as methyl formate, methyl acetate, and ethyl acetate, diethyl ether, ethylene glycol diethyl ether, Examples include ethers such as tetrahydropyran, acetals such as methylal, and alcohols such as isobutyl alcohol and sec-butyl alcohol. These organic solvents may be used alone or in combination of two or more.

  The organic solvent used in the first step may be a mixed organic solvent as long as the solubility in water at 20 ° C. is 5% by mass or more and 40% by mass or less as a whole. For example, ketones such as methyl propyl ketone, diethyl ketone, methyl isobutyl ketone and ethyl butyl ketone, esters such as diethyl carbonate, butyl formate, propyl acetate and butyl acetate, ethers such as diisopropyl ether and dibutyl ether, pentane and hexane , Aliphatic hydrocarbons such as heptane and octane, aromatic hydrocarbons such as benzene, toluene and xylene, halogenated hydrocarbons such as methylene chloride and chloroform, and acetone, cyclohexanone, etc. Ketones, γ-valerolactone, esters such as ethylene glycol monomethyl ether, ethers such as dioxane and ethylene glycol monomethyl ether, alcohols such as ethanol, isopropyl alcohol, and t-butyl alcohol Class, mixed organic solvent and the like in combination as appropriate of two or more and highly water-soluble organic solvent such as tetrahydrofuran.

  The organic solvent used in the first step is preferably one having a specific gravity lighter than water from the viewpoint of facilitating removal of the liquid phase (mainly the aqueous phase) in the second step described later.

  The amount of the organic solvent mixed with the aqueous latex is preferably 50 parts by mass or more (particularly 60 parts by mass or more) and 250 parts by mass or less (particularly 150 parts by mass or less) with respect to 100 parts by mass of the aqueous latex. When the amount of the organic solvent mixed is less than 50 parts by mass, it may be difficult to form an aggregate of polymer fine particles contained in the aqueous latex. In addition, when the amount of the organic solvent mixed exceeds 300 parts by mass, the amount of water required to obtain the polymer fine particles slowly aggregates thereafter may increase, and the production efficiency may decrease.

  A well-known thing can be used for mixing operation of the said aqueous latex and an organic solvent. For example, a general apparatus such as a stirring tank with a stirring blade may be used, or a static mixer (static mixer), a line mixer (a system in which a stirring apparatus is incorporated in a part of piping), or the like may be used.

  The first step includes an operation of adding and mixing excess water after the operation of mixing the aqueous latex and the organic solvent. As a result, phase separation occurs, and polymer fine particles can be obtained in a gentle state. In addition, most of the electrolyte such as the water-soluble emulsifier or dispersant, the water-soluble polymerization initiator, or the reducing agent used in the preparation of the aqueous latex can be eluted into the aqueous phase.

  The mixing amount of water is 40 parts by mass or more (particularly 60 parts by mass or more) and 300 parts by mass or less (particularly 250 parts by mass or less) with respect to 100 parts by mass of the organic solvent used when mixing with the aqueous latex. preferable. When the amount of water mixed is less than 40 parts by mass, it may be difficult to obtain polymer fine particles as a slow aggregate. Further, when the amount of water exceeds 300 parts by mass, the concentration of the organic solvent in the agglomerated polymer fine particles becomes low, so the time required for redispersing the agglomerated polymer fine particles in the second step described later is long. In some cases, the dispersibility of the polymer fine particles may decrease.

(Second step: Preparation of polymer fine particle dispersion)
The second step includes an operation of separating and collecting the agglomerated polymer fine particles from the liquid phase to obtain a polymer fine particle dope. By such an operation, water-soluble impurities such as an emulsifier can be separated and removed from the polymer fine particles.

  As a method for separating and collecting the agglomerated polymer fine particles from the liquid phase, for example, the agglomerated polymer fine particles generally have a floating property with respect to the liquid phase. Examples of the method include discharging a liquid phase (mainly an aqueous phase) from the bottom, and filtering using a filter paper, a filter cloth, or a metal screen having a relatively wide opening.

  The amount of the organic solvent contained in the aggregate of the polymer fine particles is preferably 30% by mass or more (particularly 35% by mass or more), and 75% by mass or less (particularly 70% by mass or less) with respect to the total mass of the polymer fine particles. It is preferable that If the content of the organic solvent is less than 30% by mass, it takes a long time to re-disperse the polymer fine particle dope in the organic solvent (described later), and irreversible aggregates tend to remain. May occur. Further, when the content of the organic solvent exceeds 75% by mass, a large amount of water dissolves and remains in the organic solvent, which may cause the polymer fine particles to aggregate in the third step. .

  In this specification, the amount of the organic solvent contained in the polymer fine particle aggregate is determined by drying the polymer fine particle aggregate at 120 ° C. for 15 minutes, and then reducing the amount of organic solvent contained in the aggregate. It was determined by setting the amount of solvent.

  The second step includes an operation of mixing the aggregate of polymer fine particles with an organic solvent. Since the polymer fine particles are aggregated in a gradual state, the polymer fine particles can be easily redispersed in the state of primary particles in the organic solvent by mixing with the organic solvent.

  Examples of the organic solvent used in the second step include the organic solvents exemplified as those that can be used in the first step. By using such an organic solvent, water contained in the polymer fine particles can be removed by azeotroping with water when the organic solvent is distilled off in the third step described later. In addition, the organic solvent used in the second step may be different from the organic solvent used in the first step, but in the second step, from the viewpoint of making the redispersibility of the aggregate more reliable, the first step It is preferable that it is the same kind as the organic solvent used in 1.

  The mixing amount of the organic solvent used in the second step is 40 parts by mass or more (more preferably 200 parts by mass or more), 1400 parts by mass or less (more preferably 1000 parts by mass or less) with respect to 100 parts by mass of the polymer fine particle aggregate. ). When the amount of the organic solvent mixed is less than 40 parts by mass, the polymer fine particles are difficult to uniformly disperse in the organic solvent, and the agglomerated polymer fine particles may remain as a lump, or the viscosity may increase and handling may be difficult. . On the other hand, when the amount of the organic solvent mixed exceeds 1400 parts by mass, a large amount of energy and a large-scale apparatus are required for evaporating and distilling the organic solvent in the third step described later, which is uneconomical.

  In the present invention, the agglomerated polymer fine particles are separated and recovered from the liquid phase between the first step and the second step, and again an organic solvent having a solubility in water at 20 ° C. of 5% by mass to 40% by mass After mixing, it is preferable to perform one or more operations of further mixing with excess water to obtain polymer fine particles of the polymer fine particles. In addition, this makes it possible to lower the remaining amount of water-soluble impurities such as emulsifiers contained in the polymer fine particle dope.

(Third step: Preparation of polymer fine particle dispersion composition)
The third step includes an operation of replacing the medium with the organic solvent in the organic solvent solution of the polymer fine particles obtained in the second step. By such an operation, a polymer fine particle dispersion composition in which polymer fine particles are dispersed in a primary particle state can be obtained. In addition, water remaining in the aggregates of the polymer fine particles can be distilled off azeotropically.

  What is necessary is just to adjust suitably the mixing amount of the said medium used at a 3rd process according to the polymer fine particle density | concentration in the polymer fine particle dispersion composition desired finally.

  Moreover, a well-known method is applicable as a method of distilling off the organic solvent. For example, a method of preparing a mixture of an organic solvent solution and the medium in a tank and distilling under reduced pressure by heating, a method of countercurrently contacting the mixture with a dry gas in the tank, or a continuous type using a thin film evaporator Examples thereof include a method and a method using an extruder equipped with a devolatilization mechanism or a continuous stirring tank. Conditions such as temperature and time required for distilling off the organic solvent can be appropriately selected within a range that does not impair the quality of the resulting polymer fine particle dispersion composition. Further, the amount of the volatile component remaining in the polymer fine particle dispersion composition can be appropriately selected within the range where there is no problem depending on the purpose of use of the polymer fine particle dispersion composition.

  Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the present invention is not limited to these, and can be implemented with appropriate modifications within a range that can meet the gist of the preceding and following descriptions. These are all included in the technical scope of the present invention.

(Evaluation method)
First, the evaluation method of the polymer fine particle dispersion composition of each Example and Comparative Example will be described below.

[1] Observation of dispersion state of polymer fine particles by transmission electron microscope A part of the obtained polymer fine particle dispersion composition is cut out, and after the polymer fine particles are dyed with ruthenium oxide or osmium oxide, a thin piece is cut out and a transmission electron microscope is cut out. (JEOL Co., Ltd., JEM-1200EX) was used for observation at a magnification of 10,000 times and 40,000 times, and the particle dispersion rate (%) was calculated by the following method.

[2] Measurement of average particle size and degree of dispersion The volume average particle size (Mv) and number average particle size (Mn) of the polymer fine particles dispersed in the aqueous latex and polymer fine particle dispersion composition are determined by Microtrac UPA150 (Nikkiso Measured using a product manufactured by Co., Ltd. The aqueous latex was diluted with deionized water, and the liquid resin composition was diluted with methyl ethyl ketone as the measurement sample. For measurement, enter the refractive index of water or methyl ethyl ketone and the refractive index of each polymer particle, and adjust the sample concentration so that the measurement time is 600 seconds and the Signal Level is in the range of 0.6 to 0.8. I went. The degree of dispersion was determined by calculating Mv / Mn from the values of Mv and Mn.

[3] Calculation of particle dispersion rate In the obtained 40,000 times transmission electron micrograph, four 5 cm square areas were selected at random, and the particle dispersion rate (%) was calculated by the method described above. The average value was used.

[4] Measurement of flexural modulus Cured plate samples were cut into test pieces having a length of 100 mm, a width (b) of 10 mm, and a thickness (h) of 5 mm, followed by curing at 23 ° C., and then autograph AG-2000E ( Using Shimadzu Corporation, a three-point bending test was performed under the conditions of a distance between supporting points (L) of 80 mm and a test speed of 2 mm / min. The initial slope (F / e) of the obtained load (F) -deflection (e) curve was determined, and the flexural modulus (E) was calculated from the following mathematical formula 2. Here, (F / e) is in kN / mm units, and L, b, and h are in mm units.

[5] Fracture toughness measurement The cured plate sample was cut into a test piece having a length of 2.5 inches, a width (b) of 0.5 inches, and a thickness (h) of 5 mm, and then a V-notch was formed by a notching machine. Thereafter, a crack was made from the tip of the V notch to the center of the test piece using a razor blade. After curing the test piece at 23 ° C., a three-point bending test was performed using Autograph AG-2000E (manufactured by Shimadzu Corporation) at a distance between supporting points (L) of 50 mm and a test speed of 1 mm / min. Using the maximum strength F (kN) obtained from the bending test, the fracture toughness value K1c (MPa · m ^1/2 ) was calculated according to the following formulas 3 and 4. Here, a is the sum of the depth of the V notch and the length from the V notch tip to the crack tip, and L, h, a, and b are in cm.

(Production Example 1 of Aqueous Latex Containing Polymer Fine Particles 1: Acrylic Rubber Polymer 1)
In a glass reactor having a thermometer, a stirrer, a reflux condenser, a nitrogen inlet, a monomer and an emulsifier addition device, 154 parts by mass of deionized water, 0.006 parts by mass of disodium ethylenediaminetetraacetate (EDTA),
In a nitrogen stream, charged with 0.0015 parts by mass of ferrous sulfate heptahydrate, 0.2 parts by mass of sodium formaldehyde sulfoxylate (SFS), and 3.0 parts by mass of sodium dodecylbenzenesulfonate (SDBS) The temperature was raised to 60 ° C. with stirring.

  Next, a mixture of 70 parts by mass of butyl acrylate (BA), 1.4 parts by mass of allyl methacrylate (ALMA) and 0.02 parts by mass of cumene hydroperoxide (CHP) was continuously added over 170 minutes. It was dripped. After completion of the addition of the mixture, stirring was continued for 0.3 hours to complete the polymerization, and an aqueous latex (R-1) containing an elastic core layer of polymer fine particles was obtained.

  Subsequently, after adding 66 parts by mass of deionized water, 10 parts by mass of styrene (St), 5 parts by mass of acrylonitrile (AN), 8.3 parts by mass of methyl methacrylate (MMA), 6.7 parts of glycidyl methacrylate (GMA). A mixture of parts by weight, 0.85 parts by weight of ALMA, and 0.08 parts by weight of CHP was continuously added over 200 minutes. After completion of the addition, 0.04 part by mass of CHP was added, and stirring was further continued for 1 hour to complete the polymerization, thereby obtaining an aqueous latex (L-1) containing polymer fine particles. The polymerization conversion rate of the monomer component was 99% or more. The volume average particle diameter of the polymer fine particles contained in the obtained aqueous latex was 13 nm.

(Production Examples 2 to 5 of Aqueous Latex Containing Polymer Fine Particles: Acrylic Rubber Polymers 2 to 5)
In Production Example 1, an aqueous solution containing fine polymer particles in the same manner as in Production Example 1 except that 1.5, 0.42, 0.125, and 0.035 parts by mass were used instead of 3.0 parts by mass of SDBS, respectively. Latex (L-2, L-3, L-4, L-5) was obtained. The polymerization conversion rate of the monomer components was 99% or more. The volume average particle diameters of the polymer fine particles contained in the obtained aqueous latex were 43, 104, 136 and 199 nm, respectively.

(Production Example 6 of aqueous latex containing polymer fine particles: diene rubber polymer)
In a pressure-resistant polymerization machine, 200 parts by mass of deionized water, 0.03 parts by mass of tripotassium phosphate, 0.002 parts by mass of EDTA, 0.001 part by mass of ferrous sulfate and heptahydrate, and 1.55 parts by mass of SDBS Was added, nitrogen was sufficiently substituted while stirring to remove oxygen, and 100 parts by mass of butadiene (Bd) was added to the system, and the temperature was raised to 45 ° C. Polymerization was started by adding 0.03 parts by mass of paramentane hydroperoxide (PHP) and subsequently 0.10 parts by mass of SFS. 0.025 parts by mass of PHP was added at 3, 5, and 7 hours from the start of polymerization. In addition, 0.0006 parts by mass of EDTA and 0.003 parts by mass of ferrous sulfate / pentahydrate were added at 4, 6 and 8 hours after the start of polymerization. At 15 hours after polymerization, the residual monomer was removed by devolatilization under reduced pressure to complete the polymerization, and an aqueous latex containing an elastic core layer mainly composed of polybutadiene rubber was obtained. The volume average particle diameter of the elastic core layer of the polymer fine particles contained in the obtained aqueous latex was 90 nm.

  A glass reactor having a thermometer, a stirrer, a reflux condenser, a nitrogen inlet, and a monomer addition device, and 215 parts by mass of an aqueous latex containing an elastic core layer mainly composed of the polybutadiene rubber (70 parts by mass of polybutadiene rubber particles) Part) and 98 parts by mass of deionized water were added and stirred at 60 ° C. while performing nitrogen substitution. After adding 0.004 parts by mass of EDTA, 0.001 part by mass of ferrous sulfate heptahydrate and 0.2 parts by mass of SFS, St 10 parts by mass, AN 5 parts by mass, MMA 8.3 parts by mass, GMA 6.7 parts by mass And a mixture of 0.08 parts by weight of CHP were continuously added over 200 minutes. After completion of the addition, 0.04 part by mass of CHP was added, and stirring was further continued for 1 hour to complete the polymerization, thereby obtaining an aqueous latex (L-3) containing polymer fine particles. The polymerization conversion rate of the monomer component was 99% or more. The volume average particle diameter of the polymer fine particles contained in the obtained aqueous latex was 100 nm.

  The monomer compositions of Production Examples 1 to 6 are summarized in Table 1 below.

Example 1
126 parts by mass of methyl ethyl ketone (MEK) was introduced into a 1 L mixing tank at 30 ° C., and 126 parts by mass of an aqueous latex of polymer fine particles obtained in Production Example 1 was added while stirring. After mixing uniformly, 200 parts (total 452) parts of water was added at a supply rate of 80 parts by weight / minute. When the stirring was stopped immediately after the supply was completed, a slurry liquid containing floating aggregates was obtained. Next, 350 mass parts of liquid phases were discharged | emitted from the discharge outlet of the tank lower part, leaving the aggregate. 150 parts by mass of MEK was added to the obtained aggregate (polymer fine particle dope) and mixed (residual 252) to obtain an organic solvent solution in which the polymer fine particles were dispersed. 100 parts by mass of liquid bisphenol A type epoxy resin (“JER828EL” manufactured by JER) was added to 71.6 parts by mass of this organic solvent solution (including 11.1 parts by mass of polymer fine particles), and after mixing, MEK was distilled off under reduced pressure. Then, a bisphenol A type epoxy resin in which polymer fine particles were dispersed was obtained as a polymer fine particle dispersed composition 1.

  65 g of this polymer fine particle dispersion composition 1 (epoxy equivalent; 208 g / eq), 34.2 g of JER828EL (epoxy equivalent; 187 g / eq), diaminodiphenyl sulfone (“Aradur9664-1” manufactured by Huntsman, active amine equivalent) as a curing agent; 62 g / eq) 30.8 g was mixed well (including 5% by weight of polymer fine particles) while maintaining at 130 ° C., and further defoamed to obtain a liquid resin composition. This liquid resin composition was poured between two glass plates sandwiching a spacer having a thickness of 5 mm, and cured in a hot air oven at 150 ° C. for 1 hour and then at 180 ° C. for 2 hours to obtain a cured plate 1 having a thickness of 5 mm. . Table 2 shows the physical property values of the cured plate 1.

(Comparative Example 1)
Except that the polymer fine particle dispersion composition was not mixed, only liquid bisphenol A type epoxy resin JER828EL; 97.6 g and diaminodiphenylsulfone Aradur96664-1; 32.4 g as a curing agent were mixed. Thus, a cured plate was obtained. Table 2 shows the physical property values of this cured plate.

(Example 2 and Comparative Examples 2 to 5)
In Example 1, in place of the aqueous latex of polymer fine particles obtained in Production Example 1, the same procedure as in Example 1 was used except that the aqueous latex of each polymer fine particle obtained in Production Examples 2 to 6 was used. Epoxy resin compositions 2 to 6 in which polymer fine particles were dispersed and cured plates 2 to 6 were obtained as cured plates of Example 2 and Comparative Examples 2 to 5, respectively. Table 2 shows physical property values of the cured plates 2 to 6. In addition, for the cured plate obtained in Example 2, the above-described method, specifically, an ultrathin sample was cut out with a microtome, stained with ruthenium oxide, observed with a transmission electron microscope to observe the dispersion state of the polymer fine particles, and particle dispersion The rate was calculated. The micrograph is shown in FIG. The particle dispersion rate was 55%.

  As an example, as shown in FIG. 1 for the results of Example 2, in the polymer fine particle dispersion compositions obtained in Examples 1 and 2, the polymer fine particles were dispersed independently without agglomeration. In these cured products, even when polymer fine particles are added, the fracture toughness is greatly improved in spite of almost no decrease in elastic modulus as compared with the cured product of Comparative Example 1 in which no polymer fine particles are added. . On the contrary, in the cured products of Comparative Examples 2 to 5 having a large volume average particle diameter of 100 nm or more, the modulus of elasticity is reduced by adding polymer fine particles, and the improvement in fracture toughness is small compared to that.

  It is known that the particle diameter of the crosslinked polymer particles is made as small as possible, for example, 25 nm or less, and there are reports of nano-dispersion due to self-alignment of non-crosslinked polymers. So far, it has not been carried out to disperse the finely crosslinked polymer fine particles in a medium other than water, in particular, an epoxy resin, a vinyl monomer or other polymerizable organic substance or polymer solid. In addition, the effect of the present invention that can significantly improve the fracture toughness without substantially reducing the elastic modulus as compared with a cured product to which polymer fine particles are not added is an effect that has been found for the first time by the present inventors.

Claims (11)

A polymer fine particle dispersion composition comprising 100 parts by weight of a medium mainly composed of components other than water and 0.1 part by weight to 150 parts by weight of polymer fine particles,
The polymer fine particles have a volume average particle diameter of 50 nm or less and a crosslinked polymer layer;
The polymer microparticles are independent dispersed in the medium,
The polymer fine particle dispersion composition, wherein the polymer fine particle includes at least two layers of the cross-linked polymer layer present on the inner side and the coating polymer layer present on the outermost side .   The polymer fine particle dispersion composition according to claim 1, wherein the crosslinked polymer layer is a crosslinked rubber-like polymer having a Tg of 0 ° C. or less.   The polymer fine particle dispersion composition according to claim 2, wherein the crosslinked rubber-like polymer is at least one selected from the group consisting of a diene rubber polymer, an acrylic rubber polymer, and an organosiloxane rubber polymer. . The coating polymer layer comprises a coating polymer layer polymer obtained by polymerizing a coating polymer layer component,
The coating polymer layer component contains a monomer containing a functional group having a polymerizable or curing reactivity,
The functional group having polymerizable or curing reactivity is epoxy group, oxetane group, hydroxyl group, carbon-carbon double bond, amino group, imide group, carboxylic acid group, carboxylic anhydride group, cyclic ester, cyclic The polymer fine particle dispersion composition according to any one of claims 1 to 3 , which is at least one selected from the group consisting of an amide, a benzoxazine group, and a cyanate ester group. The polymer fine particles further include an intermediate polymer layer that is in contact with the cross-linked polymer layer and exists on the outside thereof,
Intermediate polymer layer comprises a polyfunctional monomer 30 to 100 wt%, and the intermediate polymer layer polymer obtained by polymerizing the intermediate polymeric layer component comprising other vinyl monomer 0-70% by weight, claims 1 to 4 The polymer fine particle dispersion composition according to any one of the above. The medium is at least one selected from the group consisting of a cured curable or polymerizable monomer, a cured curable or polymerizable oligomer, and a thermoplastic polymer, and is solid at room temperature. there, the polymer fine particle dispersion composition according to any one of claims 1-5. The medium is curable or polymerizable monomers, curable or polymerizable oligomer, and is at least one member selected from the group consisting of organic solvents, and are liquid at room temperature, either of claims 1-5 1 polymer fine particle dispersion composition according to item. The curable or polymerizable monomer or curable or polymerizable oligomer, polymeric, or an organic compound containing a functional group having a curing reactive polymer fine particle dispersion according to claim 6 or 7, Composition. The polymerizable or curing functional group is an epoxy group, oxetane group, hydroxyl group, carbon-carbon double bond, amino group, imide group, carboxylic acid group, carboxylic anhydride group, cyclic ester, cyclic The polymer fine particle dispersion composition according to claim 8 , which is at least one selected from the group consisting of an amide, a benzoxazine group, and a cyanate ester group. A method for producing a polymer fine particle dispersion composition according to any one of claims 1 to 9 , comprising:
An aqueous medium dispersion in which the polymer fine particles are dispersed in an aqueous medium is mixed with an organic solvent having a solubility in water at 20 ° C. of 5% by mass to 40% by mass, and further mixed with excess water. A first step of slowly agglomerating polymer fine particles to obtain a polymer fine particle agglomerate;
A second step of separating and collecting the agglomerated polymer fine particles from the liquid phase and then mixing with the organic solvent again to obtain a polymer fine particle dispersion;
A third step of further distilling the organic solvent after further mixing the organic solvent solution with the medium;
A process for producing a polymer fine particle dispersion composition. The aqueous medium dispersion is prepared by using at least one method selected from the group consisting of emulsion polymerization, suspension polymerization, miniemulsion polymerization, microemulsion polymerization, and dispersion polymerization in the aqueous medium. an aqueous latex which is formed by polymerizing the polymer fine particles, method for producing a polymer fine particle dispersion composition according to claim 10.