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WO2016088800A1 - Microsphères thermo expansibles adhésives et procédé de production de celles-ci - Google Patents

Microsphères thermo expansibles adhésives et procédé de production de celles-ci Download PDF

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Publication number
WO2016088800A1
WO2016088800A1 PCT/JP2015/083875 JP2015083875W WO2016088800A1 WO 2016088800 A1 WO2016088800 A1 WO 2016088800A1 JP 2015083875 W JP2015083875 W JP 2015083875W WO 2016088800 A1 WO2016088800 A1 WO 2016088800A1
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Prior art keywords
thermally foamable
mass
foaming
polymer
microspheres
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English (en)
Japanese (ja)
Inventor
哲男 江尻
智久 長谷川
佐藤　和紀
佐藤　大輔
松崎　光浩
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Kureha Corp
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Kureha Corp
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
    • B01J13/02—Making microcapsules or microballoons
    • B01J13/06—Making microcapsules or microballoons by phase separation
    • B01J13/14—Polymerisation; cross-linking
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/16—Making expandable particles
    • C08J9/20—Making expandable particles by suspension polymerisation in the presence of the blowing agent
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K3/00—Materials not provided for elsewhere

Definitions

  • the present invention relates to a thermally foamable microsphere and a method for producing the thermally foamable microsphere, and more particularly to a thermally foamable microsphere having adhesiveness and a method for producing the same.
  • Thermally foamable microspheres (sometimes referred to as “thermally expandable microcapsules”) are used in various applications such as paints and plastic molding fillers for weight reduction, including applications in foamed inks. Applications are being developed in the field. Thermally foamable microspheres are usually obtained by encapsulating a volatile liquid foaming agent (sometimes referred to as "physical foaming agent” or "volatile swelling agent”) with a polymer and microencapsulating it. . As the foaming agent, a chemical foaming agent that decomposes when heated to generate gas may be used as desired.
  • a volatile liquid foaming agent sometimes referred to as "physical foaming agent” or "volatile swelling agent”
  • the foaming agent a chemical foaming agent that decomposes when heated to generate gas may be used as desired.
  • Thermally foamable microspheres can generally be produced by a method of suspension polymerization of a polymerizable mixture containing at least a foaming agent and a polymerizable monomer in an aqueous dispersion medium containing a dispersion stabilizer. . As the polymerization reaction proceeds, an outer shell is formed by the produced polymer, and a thermally foamable microsphere having a structure in which a foaming agent is enclosed in the outer shell is obtained.
  • Patent Document 1 discloses a thermoplastic resin-like heavy resin having a unicellular cell particle size of 1 to 50 ⁇ m in which a volatile liquid foaming agent that is gaseous at a temperature below the softening point of a polymer is enclosed. Combined particles (ie, thermally foamable microspheres) are disclosed.
  • water and a dispersing agent are added to a reaction tank, and then a liquid blowing agent such as aliphatic hydrocarbon is added to a monomer, and an oil-soluble catalyst is added to the monomer mixture.
  • a dispersing agent such as aliphatic hydrocarbon
  • an oil-soluble catalyst is added to the monomer mixture.
  • the monomer phase is added to the aqueous phase with stirring to effect suspension polymerization.
  • the suspending agent include carboxymethyl cellulose, colloidal silica, colloidal clay and the like, which are used in specific examples.
  • thermoplastic resin having a good gas barrier property is generally used as the polymer forming the outer shell of the thermally foamable microsphere.
  • the polymer forming the outer shell softens when heated.
  • the foaming agent one that is gaseous at a temperature below the softening point of the polymer is selected.
  • the foaming agent vaporizes and expands, acting on the outer shell, and the elastic modulus of the polymer forming the outer shell is rapidly reduced.
  • This temperature is referred to as a foaming start temperature (sometimes referred to as “foaming temperature”).
  • thermally foamable microsphere when heated to a temperature higher than the foaming start temperature, it expands itself and becomes a closed cell (“foamed particle”, “foamed particle”, “hollow particle”, “closed foam”). Body “or” hollow plastic balloon “, etc.).
  • aqueous dispersion medium containing a dispersion stabilizer (sometimes referred to as “dispersing agent” or “suspension agent”)
  • a polymerizable mixture containing at least a foaming agent and a polymerizable monomer mix with stirring, granulate fine droplets of the polymerizable mixture, and then raise the temperature to suspension polymerization I do. Since most of the polymerizable mixtures are usually insoluble in water, an oil phase is formed in an aqueous dispersion medium containing a dispersion stabilizer. It needs to be granulated as droplets.
  • Suspension polymerization forms thermally foamable microspheres having approximately the same particle size as the fine droplets.
  • various additives such as a dispersion stabilizer, a stabilizer (sometimes referred to as “auxiliary stabilizer”), a polymerization initiator (sometimes called “catalyst”), and a polymerization assistant. It is possible to adjust the particle shape and particle size distribution by properly selecting and combining the types and contents, and by properly selecting and combining the stirring and mixing conditions, polymerization conditions (temperature, etc.), etc. .
  • Thermally foamable microspheres utilize a characteristic of forming closed cells by heating to a temperature higher than the foaming start temperature, and are used in a wide range of fields as designability-imparting agents, functionality-imparting agents, and lightening agents. Applications are being developed in Japan. As higher performance is required in each application field, the required level for thermally foamable microspheres is also increasing. For example, improvement in processing characteristics can be mentioned as required performance for thermally foamable microspheres.
  • a composition in which a thermoplastic foam is blended with a thermoplastic resin is kneaded, calendered, extruded, thermoformed, stamped or injection molded, and in the process, the thermally foamable microsphere is molded.
  • thermoly foamable microspheres are not only blended in inks, paints and plastics in an unfoamed state, but may be used in a foamed state depending on the application. That is, the closed foam (hollow plastic balloon) in which the heat-foamable microspheres are expanded is extremely lightweight. For example, by using it as a filler of a molded product such as a paint filler or a sheet, The weight of the molded product may be reduced.
  • Thermal foamable microspheres are formed by agglomeration of hollow fine particles (synonymous with “thermal foamable microspheres”) in the foaming process to form aggregated particles, which are used as paints, sealants, and plastics.
  • thermally foamable microspheres are lightweight, in order to prevent dust from being generated during handling, they are liquid in a hollow plastic fine powder (synonymous with “thermally foamable microspheres”).
  • a method for preventing scattering by injecting a substance is known (Patent Document 5).
  • Patent Document 6 discloses a thermally foamable microsphere that has improved adhesion to other materials and has suppressed fusion between foam particles. That is, in Patent Document 6, in a thermally foamable microsphere having a structure in which a foaming agent is enclosed in an outer shell formed from a polymer, the outer shell formed from the polymer is a silane coupling agent or the like. Thermally foamable microspheres containing various organosilicon compounds are described, and the adhesion of the outer shell of thermally foamable microspheres is improved with a silane coupling agent or the like, thereby uniformly and strongly adhering inorganic fine particles. It is described that the adhesion amount can be strictly controlled.
  • thermally foamable microspheres have expanded, for example, molded products containing thermally foamable microspheres, in particular molded products containing thermally foamable microspheres with a reinforcing material, and foaming these molded products.
  • thermally foamable microspheres There is a new demand associated with use in molded articles containing expanded particles. Specifically, it is excellent in the adhesiveness between the foamed particles, and also in the adhesiveness with other materials such as the base resin and reinforcing material of the molded product.
  • thermally foamable microsphere that does not drop or scatter of fairing or foamed particles, and as a result, can have excellent mechanical properties such as strength of a molded product. .
  • thermally foamable microspheres that are excellent in adhesion between the foamed particles to be formed and the foamed particles and other materials, the foamed particles are less dropped, and the resulting molded article has good mechanical properties; In addition, it has been desired to provide a manufacturing method thereof.
  • the problem of the present invention is that the foamed particles to be formed and the adhesiveness between the foamed particles and other materials are excellent, the foamed particles are less likely to drop off, and the resulting molded article has good mechanical properties of thermal foaming. It is to provide a microsphere; and a manufacturing method thereof.
  • the present inventors have found that the problem can be solved by using a thermally foamable microsphere having a specific adhesive strength, and the present invention has been completed.
  • the residual ratio of the expanded particles obtained by free foaming at a high temperature measured by a blower test on the glass plate is 3% by mass or more based on the total mass of the expanded particles before the blower test.
  • the thermally foamable microsphere is provided.
  • the “residual rate measured by the blower test on the glass plate” of the expanded particles refers to the air blower for eyelash extension (air discharge per nozzle blow 2 mm, blow once) on the expanded particles on the glass plate.
  • the amount of the foamed particles remaining on the glass plate is measured in advance after applying air 5 times from a distance of 10 cm in the direction of 40 degrees above the center of the foamed particles on the glass plate. It is calculated as a residual rate (unit: mass%) with respect to the total mass of the expanded particles before the measured blower test.
  • the following embodiments (2) to (9) of the thermally foamable microspheres are provided as specific embodiments of the invention relating to the thermally foamable microspheres.
  • the polymerizable monomer forming the polymer is 25 to 100% by mass of at least one monomer selected from the group consisting of acrylonitrile and methacrylonitrile, vinylidene chloride, acrylic acid ester, methacrylic acid ester, Any one of (1) to (3), which is a monomer mixture containing 0 to 75% by mass of at least one monomer selected from the group consisting of styrene, acrylic acid, methacrylic acid and vinyl acetate Thermally foamable microspheres as described in 1.
  • the polymerizable monomer forming the polymer is composed of 30 to 95% by mass of vinylidene chloride and acrylonitrile, methacrylonitrile, acrylic ester, methacrylic ester, styrene, acrylic acid, methacrylic acid and vinyl acetate.
  • the thermally foamable microsphere according to any one of (1) to (3), which is a monomer mixture containing 5 to 70% by mass of at least one monomer selected from the group.
  • Any one of (1) to (5), wherein the foamed particles obtained by free foaming are foamed particles obtained by heat-treating at a temperature of 150 ° C. for 5 minutes and then freely foamed at a temperature of 180 ° C. for 3 minutes.
  • the thermally foamable microsphere according to any one of the above.
  • the thermally foamable microsphere according to (7), wherein the other substrate is at least one of a fiber, a particle, a sheet, or a bulk (9) The thermally foamable micro of (7) or (8), wherein (9) the other substrate is formed of at least one selected from the group consisting of glass, metal, plastic, paper, and cloth.
  • a sphere is provided.
  • a molded article containing the thermally foamable microsphere according to any one of (10) (1) to (9), and (11) fibrous A molded article containing the thermally foamable microsphere according to (10), containing a reinforcing material that is at least one of a particulate form, a sheet form, and a bulk form, and (12) (10) or (11) A molded article containing foamed particles obtained by foaming a molded article containing the thermally foamable microsphere described in 1. is provided.
  • a heavy product formed by suspension polymerization of a polymerizable mixture containing at least a foaming agent and a polymerizable monomer in an aqueous dispersion medium containing a dispersion stabilizer is provided.
  • a method for producing a heat-foamable microsphere, which produces a heat-foamable microsphere in which a foaming agent is encapsulated in the outer shell of the coalescence is provided.
  • Specific embodiments thereof include the following (14) to (17):
  • a method for producing a thermally foamable microsphere is provided.
  • a thermally foamable microsphere in which a foaming agent is enclosed in the outer shell of a polymer, and the thermally foamable microsphere is freely foamed at a temperature higher than the foaming start temperature on a glass plate.
  • the thermal foaming property wherein the residual ratio of the foamed particles measured by a blower test on the glass plate is 3% by mass or more based on the total mass of the foamed particles before the blower test
  • the microsphere is a thermally foamable microsphere in which a foaming agent is enclosed in the outer shell of a polymer, and foamed particles obtained by thermal foaming are obtained.
  • the foamed microspheres are characterized by adhering the foamed particles to each other and to other base materials, so that the foamed particles to be formed and the adhesiveness between the foamed particles and other materials are excellent. particle Dropping less, the effect is achieved that the mechanical properties of the resulting molded article is provided good thermally foamable microsphere.
  • the molded product containing the thermally foamable microspheres, or the molded product containing expanded particles obtained by thermally expanding the thermally foamable microspheres there is an effect that a molded product having less mechanical dropout of foamed particles and good mechanical properties is provided.
  • the outer shell of a polymer produced by suspension polymerization of a polymerizable mixture containing at least a blowing agent and a polymerizable monomer in an aqueous dispersion medium containing a dispersion stabilizer can be easily produced by the method for producing a heat-foamable microsphere in which a foaming agent is enclosed. An effect is provided that a method for producing foamable microspheres is provided.
  • the thermally foamable microsphere of the present invention is a thermally foamable microsphere in which a foaming agent is enclosed in a polymer outer shell, and the thermally foamable microsphere is a glass plate.
  • the residual rate of the expanded particles formed by free-foaming at a temperature higher than the foaming start temperature on the glass plate is 3% by mass or more based on the total mass of the expanded particles before the blower test.
  • the temperature higher than the foaming start temperature may be any temperature as long as it is higher than the foaming start temperature. However, a temperature higher than the foaming start temperature in the range of 1 ° C to 80 ° C is preferable, and 10 ° C to 60 ° C. Higher temperatures are more preferred.
  • the foaming agent encapsulated in the outer shell of the polymer is usually a substance that becomes gaseous at a temperature below the softening point of the polymer forming the outer shell.
  • the foaming agent hydrocarbon having a boiling point corresponding to the target foaming start temperature can be used.
  • isobutane, n-butane, n-pentane, isopentane, n-hexane, petroleum ether, isooctane, isododecane, and a mixture of two or more thereof are preferable.
  • a compound which is thermally decomposed by heating and becomes gaseous may be used.
  • the foaming agent is generally used in the range of 10 to 40 parts by weight, preferably 12 to 37 parts by weight, more preferably 15 to 35 parts by weight with respect to 100 parts by weight of the polymerizable monomer described below.
  • polymerizable monomer that forms a polymer As the polymerizable monomer that forms a polymer that forms the outer shell of the thermally foamable microsphere of the present invention, it is possible to encapsulate a foaming agent, and Usually, as described later, a thermally foamable microsphere in which a foaming agent is encapsulated in an outer shell of a product polymer obtained by suspension polymerization in an aqueous dispersion medium containing a dispersion stabilizer is formed. As long as it is possible, there is no particular limitation. Preferably, from the viewpoint that the outer shell of the polymer has gas barrier properties, solvent resistance and heat resistance, and can produce a polymer having good foamability, and if desired, high temperature foamability.
  • the polymerizable monomer is at least one monomer selected from the group consisting of acrylonitrile and methacrylonitrile (the monomers may be collectively referred to as “(meth) acrylonitrile”), and / or. It is preferable to contain vinylidene chloride.
  • the polymerizable monomer other than (meth) acrylonitrile and / or vinylidene chloride is not particularly limited.
  • acrylic monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, and dicyclopentenyl acrylate are used.
  • Acid esters; Methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobornyl methacrylate; acrylic acid, methacrylic acid, vinyl chloride, styrene, vinyl acetate, ⁇ -methylstyrene, chloroprene, neoprene, butadiene, etc. Can be mentioned.
  • polymerizable monomers can be used alone or in combination of two or more.
  • a preferred polymerizable monomer is a monomer mixture containing (meth) acrylonitrile and / or vinylidene chloride.
  • the polymerizable monomer is at least one monomer selected from the group consisting of (meth) acrylonitrile (acrylonitrile and methacrylonitrile), and acrylonitrile and methacrylo A mixture of nitriles) 25 to 100% by mass and at least one monomer selected from the group consisting of vinylidene chloride, acrylic acid ester, methacrylic acid ester, styrene, acrylic acid, methacrylic acid and vinyl acetate
  • a monomer mixture containing 0 to 75% by mass (the total amount is 100% by mass) is sometimes referred to as “a monomer other than (meth) acrylonitrile”.
  • the polymerizable monomer contains 100% by mass of (meth) acrylonitrile, it may not strictly correspond to the monomer mixture, but in the present invention, the monomer including this case is included. It is called a
  • the monomer mixture containing (meth) acrylonitrile is formed as the content ratio of (meth) acrylonitrile is higher, the foaming start temperature of the thermally foamable microspheres formed is higher, and the content ratio is lower. There is a tendency that the foaming start temperature of the thermally foamable microspheres is lowered.
  • the foaming start temperature and the maximum foaming ratio of the formed thermally foamable microsphere (volume of foamed particles / thermally foamable Calculated as the volume of the fair).
  • the desired thermally foamable microspheres can be obtained.
  • Acrylonitrile and methacrylonitrile can also be used together.
  • acrylonitrile: methacrylonitrile (mass ratio) 90:10 to 10:90, preferably 80:20 to 20:80, and optionally 70:30
  • the composition can be a ratio of ⁇ 30: 70.
  • a preferred combination of (meth) acrylonitrile and a monomer other than (meth) acrylonitrile is (meth) acrylonitrile 25 to 99.5% by mass, more preferably 30 to 99% by mass, and other than (meth) acrylonitrile.
  • the monomer is 0.5 to 75% by mass, more preferably 1 to 70% by mass (the total amount is 100% by mass), and the monomer other than (meth) acrylonitrile is particularly preferably methyl methacrylate. It is.
  • the content ratio of (meth) acrylonitrile is too low, the foaming start temperature of the heat-foamable microsphere to be formed may be too low, or the gas barrier property may be insufficient.
  • the polymerizable monomer is 30 to 95% by mass of vinylidene chloride, acrylonitrile, methacrylonitrile, acrylic ester, methacrylic ester, styrene, acrylic acid, methacrylic acid and At least one monomer selected from the group consisting of vinyl acetate (hereinafter sometimes referred to as “a monomer other than vinylidene chloride”) in an amount of 5 to 70% by mass (the total amount is 100% by mass). It is preferable that it is a monomer mixture to contain.
  • the monomer mixture containing vinylidene chloride has a higher gas barrier property of the thermally foamable microsphere formed as the content ratio of vinylidene chloride is higher, and the gas barrier property tends to be lower as the content ratio is lower. .
  • Preferred combinations of vinylidene chloride and monomers other than vinylidene chloride are 35 to 90% by weight, more preferably 40 to 80% by weight, and 10 to 65% by weight of monomers other than vinylidene chloride, more preferably A monomer mixture containing 20 to 60% by mass (the total amount is 100% by mass), preferably (meth) acrylonitrile and methyl methacrylate as monomers other than vinylidene chloride and containing vinylidene chloride
  • the preferred combination is 45 to 75% by mass of vinylidene chloride, 20 to 50% by mass of (meth) acrylonitrile, and 3 to 10% by mass of methyl methacrylate (the total amount is 100% by mass). If the content ratio of vinylidene chloride is too low, the gas barrier property of the heat-foamable microspheres to be formed may be insufficient, and the desired maximum foaming ratio may not be obtained.
  • Crosslinkable monomer The polymer that forms the outer shell of the heat-foamable microsphere of the present invention is used to improve the foaming characteristics, heat resistance, and the like as a monomer together with the polymerizable monomer described above. It can be formed by using a crosslinkable monomer in combination. As the crosslinkable monomer, a compound having two or more carbon-carbon double bonds is usually used.
  • crosslinkable monomer for example, divinylbenzene, ethylene glycol di (meth) acrylate [ethylene glycol di (meth) acrylate], diethylene glycol di (meth) acrylate [diethylene glycol di (meth) acrylate] ]
  • Examples include pentaerythritol tri (meth) acrylate and pentaerythritol tetra (meth) acrylate.
  • the proportion of the crosslinkable monomer used is usually 0.01 to 5% by mass, preferably 0.02 to 3% by mass, more preferably 0.03 to 2% by mass, based on the total amount of the polymerizable monomers. .
  • thermally foamable microspheres of the present invention are formed by the foamed particles and other particles formed when the adhesion amount of the inorganic compound attached to the outer shell of the polymer is 1.8% by mass or less. This is preferable because the adhesiveness to the material is more excellent.
  • thermally foamable microspheres for example, silica and other inorganic compounds containing silicon have been widely used as dispersion stabilizers and the like, as will be described later.
  • Inorganic compounds adhering to the polymer shell of the heat-foamable microsphere of the present invention often correspond to those derived from those conventionally used inorganic compounds.
  • thermally foamable microsphere of the present invention is used in the production of a thermally foamable microsphere, and the amount of the inorganic compound used as a dispersion stabilizer or the like, that is, the resulting thermally foamable microsphere.
  • the adhesion amount of the inorganic compound remaining in the polymer outer shell has an influence on the adhesiveness of the foamed particles obtained by foaming the thermally foamable microspheres, and the inorganic adhered to the outer shell of the polymer.
  • the adhesion amount of the compound 1.8% by mass or less, desired adhesiveness of the expanded particles is realized.
  • it is an inorganic compound that is used in producing a thermally foamable microsphere, and, for example, it is water-soluble, so that it is separated from the thermally foamable microsphere obtained by washing with water, etc.
  • the inorganic compound not attached to the polymer outer shell of the conductive microsphere is not included in the amount of the inorganic compound attached to the outer shell of the polymer.
  • the amount of the inorganic compound adhering to the outer shell of the polymer is measured by a dry ashing method (unit: mass%).
  • the specific measurement procedure is as follows. That is, as a sample, about 0.5 g of thermally foamable microspheres are placed in a magnetic crucible (diameter 40 mm, height 35 mm) and covered. Heat for 1 hour with a heater of about 250 ° C. to lightly carbonize. Next, the magnetic crucible is put in a muffle furnace having a temperature of 700 ° C. and incinerated for 1 hour.
  • the amount of ash is calculated from the difference in mass before and after ashing, and the amount of inorganic compound attached (unit: mass%) is used as the ratio to the mass of the thermally foamable microspheres before ashing.
  • the adhesion amount of the inorganic compound adhering to the outer shell of the polymer is preferably 1.8% by mass or less, depending on the application, 1.75% by mass or less, and further 1.7. It can also be made into the mass% or less.
  • the adhesion amount of the inorganic compound is not particularly limited and is most preferably 0% by mass, but is usually 0.05% by mass or more, and in many cases, 0.1% by mass or more.
  • the heat-foamable microsphere is formed from the thermal foamable microsphere of the present invention.
  • the fair is preferably one containing at least one element of silicon and magnesium, and more preferably one containing at least one compound of silica or magnesium hydroxide, for example. .
  • the thermally foamable microspheres of the present invention are foamed particles obtained by freely foaming the thermally foamable microspheres on a glass plate at a temperature higher than the foaming start temperature.
  • the foaming agent is included in the outer shell of the polymer.
  • foamed particles obtained by thermal foaming can be bonded to each other and other base materials, the average particle diameter and foaming start temperature are limited. It is not something.
  • examples of the other base material include those in at least one of a fibrous shape, a particulate shape, a sheet shape, and a bulk shape, and further, glass, metal (aluminum, etc.), plastic (polyester, etc.), paper, and Examples include those formed from at least one selected from the group consisting of fabrics.
  • the average particle diameter of the thermally foamable microsphere is not limited, but the average particle diameter (D50) is usually 1 to 500 ⁇ m, and in many cases 10 to 400 ⁇ m. is there.
  • the average particle size (D50) of the thermally foamable microsphere is measured using a laser diffraction particle size distribution measuring device (such as SALD series manufactured by Shimadzu Corporation). ) Is a 50% particle diameter (sometimes referred to as “median diameter”) obtained on the basis of a particle size distribution curve (volume basis and logarithmic scale) (unit: ⁇ m).
  • the cushioning property and lightness may be insufficient, and if the average particle size is too large, the foamed particles will be too large, resulting in repeated compression. Fatigue resistance and strength may be insufficient.
  • the foaming start temperature (foaming temperature) of the thermally foamable microsphere of the present invention is not limited. From the viewpoint of being able to form foamed particles that are lightweight and have improved strength, cushioning properties, and the like because stability is obtained, the foaming start temperature is usually 100 to 220 ° C., and in many cases 130 to 215. ° C.
  • the foaming start temperature of the thermally foamable microsphere can be measured using a thermomechanical analyzer.
  • the temperature was increased at a rate of temperature increase of 5 ° C./min, and the temperature at which the displacement of the height of the sample in the container started was determined as the foaming start temperature (hereinafter referred to as the foam start temperature). , “Ts” (unit: ° C.). If the foaming start temperature of the heat-foamable microsphere is too low, for example, foaming may occur early during kneading before molding of a molded product containing the heat-foamable microsphere. If the foaming start temperature of the thermally foamable microsphere is too high, foamed particles having a desired diameter may not be formed.
  • the heat-foamable microspheres obtained can be heat treated at a temperature below the foaming start temperature as necessary to improve the uniformity of foaming (thermal expansion) and the properties of the foamed particles, It can adjust so that the foaming start temperature of the heat-foamable microsphere after heat processing may be reduced.
  • the heat treatment is usually at a temperature 3 to 90 ° C. lower than the foaming start temperature of the heat-foamable microsphere before the heat treatment, often 5 to 70 ° C., usually 10 seconds to 15 minutes, often 30 seconds to 10 It is possible to select appropriately according to the condition of minutes.
  • the lowering of the foaming start temperature of the heat-foamable microsphere by the heat treatment is in the range of 5 to 70 ° C., often 10 to 60 ° C. lower than the foam start temperature of the heat-foamable microsphere before the heat treatment.
  • the thermally foamable microspheres of the present invention are excellent in the adhesiveness of foamed particles obtained by foaming the thermally foamable microspheres (adhesiveness between the obtained foamed particles and other substrates).
  • the residual ratio measured by the blower test on the glass plate of the expanded particles obtained by free-foaming the thermally foamable microspheres on the glass plate at a temperature higher than the foaming start temperature is And 3% by mass or more based on the total mass of the expanded particles before the blower test (hereinafter, the residual rate may be simply referred to as “the blower residual rate of the expanded particles”).
  • the thermally foamable microsphere of the present invention has a blower residual ratio of foamed particles of 3% by mass or more, so that a molded product containing the thermally foamable microsphere of the present invention (fibrous, particulate, sheet-like) Alternatively, it may be a molded product containing a bulky reinforcing material.) Or a foamed microsphere from a molded product containing foamed particles obtained by foaming the molded product containing the thermally foamable microsphere. In addition, there is no dropout or scattering of the foamed particles, and as a result, the mechanical properties such as the strength of the molded product can be improved, which is desirable.
  • blower residual rate of the foamed particles is 2.5% by mass. It was not exceeded, most was 2% by mass or less, and most was 1.5% by mass or less. Therefore, if the blower residual ratio of the foamed particles is 3% by mass or more, it can be said that the adhesiveness of the foamed particles is excellent. Further, from the viewpoint that the adhesiveness of the expanded particles is more excellent, the blower residual ratio of the expanded particles is preferably 15% by mass or more. Furthermore, from the viewpoint that the adhesiveness of the expanded particles is further improved, the blower residual ratio of the expanded particles is more preferably 50% by mass or more.
  • the thermally foamable microsphere of the present invention is a thermally foamable microsphere in which a foaming agent is enclosed in the outer shell of a polymer, and the foamed particles obtained by thermal foaming are the foamed particles or the like. It is characterized by adhering to the base material.
  • the blower residual ratio of the foamed particles is preferably 10% by mass or more, more preferably 15% by mass or more, and further preferably 20% by mass or more. It can also be set to 70% by mass or more.
  • the upper limit of the blower remaining rate of the expanded particles is 100% by mass, but in many cases, it may be 99.9% by mass or less.
  • the blower remaining rate of the foamed particles uses an air blower for eyelash extension (nozzle diameter 2 mm, air discharge 30 ml per blow) on the foamed particles that are freely foamed at a temperature higher than the foaming start temperature on the glass plate.
  • the residual ratio (unit: mass%) with respect to the total mass of the previous expanded particles is calculated. Specifically, it can measure about the expanded particle obtained by the following method. That is, as a sample, 0.01 g of thermally foamable microspheres was placed on the upper surface of a glass plate (preparation: length 75 mm, width 25 mm, thickness 1 mm, washed and dried with acetone) (range where the sample is placed: length 40 mm, width 18 mm.), Free foaming for 3 minutes at a temperature higher than the foaming start temperature.
  • the blower residual rate of the expanded particles can be measured for the expanded particles that are freely expanded by the following method. That is, as a sample, 0.01 g of thermally foamable microspheres heat-treated at a temperature of 150 ° C. for 5 minutes in advance is placed on the upper surface of the glass plate (preparation) (the range in which the sample is placed: 40 mm long and 18 mm wide). And free foaming at 180 ° C. for 3 minutes.
  • the direction of 40 degrees above the center of the expanded particles on the glass plate After air is applied 5 times from a distance of 10 cm, the mass of the expanded particles remaining on the glass plate is measured (specifically, the total mass of the expanded particles remaining on the glass plate and the glass plate is measured).
  • the residual ratio (unit: mass%) is calculated as a ratio to the total mass (specifically 0.01 g) of the expanded particles before the blower test measured in advance.
  • thermally foamable microspheres obtained by the present invention can be used in various fields either expanded (expanded) or unexpanded. Is done.
  • Thermally foamable microspheres are used, for example, as paint fillers for automobiles, foaming inks for foamed ink (wallpaper, relief patterns such as T-shirts), anti-shrinkage agents, etc. Is done.
  • Thermally foamable microspheres use the volume increase caused by foaming to reduce the weight and porosity of plastics, paints, various materials, etc., and add various functions (for example, slip properties, heat insulation properties, cushion properties, Used for purposes such as sound insulation.
  • the thermally foamable microspheres according to the present invention can be suitably used for reducing the weight of plastic molded products (for example, interior materials) required for strength and surface smoothness.
  • a molded article containing the thermally foamable microsphere of the present invention can be provided.
  • a conventionally known plastic molding method can be employed. Specifically, a general-purpose plastic molding method such as kneading, calendaring, extrusion, thermoforming, stamping, or injection molding can be used. A resin molding method may be mentioned.
  • the foamed microsphere of the present invention contains a reinforcing material in the molded product, it has excellent adhesion to the reinforcing material, so that it is fibrous, particulate, sheet-like or bulk-like.
  • thermoly foamable microspheres containing at least one reinforcing material and molded articles containing the aforementioned thermally foamable microspheres (fibrous, particulate, sheet or bulk)
  • a molded article containing at least one reinforcing material is preferable (but not limited to this).
  • the molded article contains foamed particles obtained by foaming a thermally foamable microsphere.
  • a molded article is provided.
  • reinforcing material that is at least one of fibrous, particulate, sheet or bulk As the reinforcing material that is at least one of fibrous, particulate, sheet-like or bulk-like contained together with the heat-expandable microsphere of the present invention, conventionally, a molded article containing the heat-expandable microsphere or the above-mentioned Fibrous, particle-like, sheet-like (strip-like, slit-like, film-like, plate-like, etc.) used in molded products containing foamed particles obtained by foaming a molded product containing thermally foamable microspheres Or a bulk material (including a shape such as a lump shape or an irregular cross-sectional shape) can be used.
  • a material, a size, a specific shape (length, diameter, thickness, etc.), and a content for forming a reinforcing material that is at least one of a fiber shape, a particle shape, a sheet shape, and a bulk shape, and a content thereof are conventionally known.
  • glass fiber, carbon fiber, glass balloon, titanium oxide whisker or the like can be used, and a fabric-like reinforcing material such as woven fabric, nonwoven fabric or knitted fabric can also be used.
  • the content of the reinforcing material is usually 1 to 50% by mass, and in many cases 2 to 30% by mass in the molded product.
  • the method for producing the thermally foamable microsphere of the present invention is a polymerization method comprising at least a foaming agent and a polymerizable monomer in an aqueous dispersion medium containing a dispersion stabilizer.
  • This is a method for producing a thermally foamable microsphere in which a foaming agent is encapsulated in the outer shell of a polymer produced by suspension polymerization of the mixture.
  • the dispersion stabilizer and various additives described below (auxiliary stabilizer, polymerization initiator, etc.) Etc. are not particularly limited, and conventionally known ones can be used. That is, the production method of the present invention can be applied to the production of all types of thermally foamable microspheres.
  • Aqueous Dispersion Medium In the method for producing a thermally foamable microsphere of the present invention, suspension polymerization is usually carried out in an aqueous dispersion medium containing a dispersion stabilizer (suspension agent).
  • a dispersion stabilizer sustained release water
  • water can be used, and specifically, deionized water or distilled water can be used.
  • the amount of the aqueous dispersion medium used with respect to the total amount of the polymerizable monomers is not particularly limited, but is usually 0.2 to 30 times, often 0.3 to 10 times (mass ratio).
  • the dispersion stabilizer examples include silica, calcium phosphate, magnesium hydroxide, aluminum hydroxide, ferric hydroxide, barium sulfate, calcium sulfate, sodium sulfate, calcium oxalate, calcium carbonate, Examples thereof include barium carbonate and magnesium carbonate.
  • the dispersion stabilizer is usually used at a ratio of 0.1 to 20 parts by mass with respect to 100 parts by mass of the total amount of polymerizable monomers.
  • the heat-foamable microsphere using an inorganic compound as a dispersion stabilizer is used.
  • the inorganic compound more preferably contains at least one of silicon and magnesium, and more preferably contains at least one of silica and magnesium hydroxide.
  • auxiliary stabilizers such as condensation products of diethanolamine and aliphatic dicarboxylic acids, condensation products of urea and formaldehyde, polyvinylpyrrolidone, polyethylene oxide, polyethyleneimine, tetramethylammonium hydroxide, gelatin, Methyl cellulose, polyvinyl alcohol, dioctyl sulfosuccinate, sorbitan ester, various emulsifiers and the like can be used.
  • One preferred combination of a dispersion stabilizer and an auxiliary stabilizer is a combination of colloidal silica and a condensation product.
  • a condensation product of diethanolamine and an aliphatic dicarboxylic acid is preferable, and a condensation product of diethanolamine and adipic acid or a condensation product of diethanolamine and itaconic acid is particularly preferable.
  • the condensate is defined by its acid value (unit: mg KOH / g).
  • the acid value is 60 or more and less than 95.
  • Particularly preferred is a condensate having an acid value of 65 or more and 90 or less.
  • an inorganic alkali metal salt such as sodium chloride or sodium sulfate
  • Sodium chloride is suitably used as the inorganic alkali metal salt.
  • the amount of colloidal silica used varies depending on the particle size, but is usually used in a proportion of 1 to 20 parts by weight, preferably 2 to 10 parts by weight, based on 100 parts by weight of the total amount of polymerizable monomers.
  • the condensation product is usually used at a ratio of 0.05 to 2 parts by mass with respect to 100 parts by mass of the total amount of polymerizable monomers.
  • the inorganic salt is used in a proportion of 0 to 150 parts by mass, and in many cases 0.5 to 100 parts by mass with respect to 100 parts by mass of the total amount of polymerizable monomers.
  • a combination of colloidal silica and a water-soluble nitrogen-containing compound examples include polyvinyl pyrrolidone, polyethyleneimine, polyoxyethylene alkylamine, polydialkylaminoalkyl (meth) acrylate represented by polydimethylaminoethyl methacrylate and polydimethylaminoethyl acrylate, and polydimethylaminopropyl.
  • examples thereof include polydialkylaminoalkyl (meth) acrylamides represented by acrylamide and polydimethylaminopropylmethacrylamide, polyacrylamide, polycationic acrylamide, polyamine sulfone, and polyallylamine.
  • a combination of colloidal silica and polyvinylpyrrolidone is preferably used.
  • Another preferred combination is a combination of magnesium hydroxide and / or calcium phosphate and an emulsifier.
  • a poorly water-soluble metal hydroxide obtained by reaction in a water phase of a water-soluble polyvalent metal compound (for example, magnesium chloride) and an alkali metal hydroxide salt (for example, sodium hydroxide) for example, a colloid of magnesium hydroxide
  • a reaction product in an aqueous phase of sodium phosphate and calcium chloride can be used.
  • An emulsifier is not generally used, but an anionic surfactant such as a dialkyl sulfosuccinate or a polyoxyethylene alkyl (allyl) ether phosphate may be used if desired.
  • an anionic surfactant such as a dialkyl sulfosuccinate or a polyoxyethylene alkyl (allyl) ether phosphate may be used if desired.
  • aqueous dispersion medium containing the dispersion stabilizer as the polymerization aid at least selected from the group consisting of alkali metal nitrite, stannous chloride, stannic chloride, water-soluble ascorbic acids, and boric acid.
  • a kind of compound can be present.
  • polymerization particles do not agglomerate at the time of polymerization, the polymer does not adhere to the polymerization can wall, and is stable while efficiently removing heat generated by polymerization.
  • a thermally foamable microsphere can be produced.
  • alkali metal nitrites sodium nitrite or potassium nitrite is preferable in terms of availability and price.
  • These compounds are usually used in a proportion of 0.001 to 1 part by mass, preferably 0.01 to 0.1 part by mass, with respect to 100 parts by mass of the total amount of polymerizable monomers.
  • Polymerization initiator The polymerizable monomer described above can be subjected to suspension polymerization by contacting with a polymerization initiator in a predetermined temperature environment.
  • the polymerization initiator is not particularly limited, and those generally used in this field can be used, but an oil-soluble polymerization initiator soluble in the polymerizable monomer to be used is preferable.
  • Examples of the polymerization initiator include dialkyl peroxide, diacyl peroxide, peroxy ester, peroxy dicarbonate, and azo compound.
  • dialkyl peroxides such as methyl ethyl peroxide, di-t-butyl peroxide, dicumyl peroxide; isobutyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, 3, 5, Diacyl peroxide such as 5-trimethylhexanoyl peroxide; t-butyl peroxypivalate, t-hexyl peroxypivalate, t-butyl peroxyneodecanoate, t-hexyl peroxyneodecanoate, 1 -Cyclohexyl-1-methylethylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, cumylperoxyneodecanoate, ( ⁇ , ⁇ -bis-neodecanoyl Peroxy) peroxy such as diisopropylbenzene Esters; bis (4-
  • Suspension polymerization is carried out in an aqueous dispersion medium containing a dispersion stabilizer (suspension agent).
  • a dispersion stabilizer suspension agent
  • the order in which each component such as a dispersion stabilizer is added to the aqueous dispersion medium is arbitrary as long as a thermally foamable microsphere having excellent physical properties such as foaming ratio can be produced.
  • An aqueous dispersion medium containing a dispersion stabilizer is prepared by adding a dispersion stabilizer and, if necessary, an auxiliary stabilizer and a polymerization aid. In carrying out the suspension polymerization, it is preferable to select optimum pH conditions depending on the type of dispersion stabilizer and auxiliary stabilizer used.
  • silica such as colloidal silica
  • an acid is added to an aqueous dispersion medium containing the dispersion stabilizer to adjust the pH of the system to about 3 Adjust to ⁇ 4.
  • magnesium hydroxide or calcium phosphate is used as the dispersion stabilizer, the polymerization is performed in an alkaline environment.
  • a foaming agent, a polymerizable monomer, and a crosslinkable monomer as necessary are mixed, and at least the foaming agent is polymerized.
  • a polymerizable mixture containing a polymerizable monomer is prepared.
  • a foaming agent, a polymerizable monomer, a crosslinkable monomer, and the like may be added to the aqueous dispersion medium containing the previous dispersion stabilizer.
  • a polymerizable mixture containing at least a foaming agent and a polymerizable monomer is added to the aqueous dispersion medium containing the previous dispersion stabilizer and mixed with stirring.
  • the polymerization initiator can be used by adding to the polymerizable monomer in advance, but if it is necessary to avoid early polymerization, a polymerizable mixture containing at least a foaming agent and a polymerizable monomer May be added to the aqueous dispersion medium containing the previous dispersion stabilizer, and when stirring and mixing, a polymerization initiator may be added and integrated in the aqueous dispersion medium.
  • the polymerizable mixture By stirring and mixing the polymerizable mixture and the aqueous dispersion medium containing the dispersion stabilizer, the polymerizable mixture forms droplets that are an oil phase in the aqueous dispersion medium containing the dispersion stabilizer. By doing so, it can be granulated as fine droplets protected and stabilized by a dispersion stabilizer of a desired size.
  • the average particle diameter of the droplets is preferably substantially the same as the average particle diameter (D50) of the target heat-foamable microsphere, and is therefore usually in the range of 1 to 500 ⁇ m, preferably 10 to 400 ⁇ m.
  • conditions such as the type of stirrer and the number of rotations are set according to the desired particle size of the thermally foamable microsphere. At this time, the conditions are selected in consideration of the size and shape of the polymerization can and the presence or absence of baffles.
  • a homogenizer having a high shearing force is preferable, and a continuous high-speed rotation high-shear type agitation disperser or a batch type (batch type) high-speed rotation high-shear type agitation disperser (batch type high-speed emulsification and dispersion machine) should be used. Can do.
  • the stirring rotation speed when the aqueous dispersion medium and the polymerizable mixture containing the dispersion stabilizer are stirred and dispersed in the stirrer is determined in consideration of the type of the stirrer, the processing time in the stirrer, the crushing rotation speed, and the like. be able to.
  • the aqueous dispersion medium and the polymerizable mixture containing the dispersion stabilizer are different from each other.
  • a flow it may be continuously fed into a continuous high-speed rotation high shear type stirring and dispersing machine at a constant ratio, or an aqueous dispersion medium containing a dispersion stabilizer and a polymerizable mixture are injected into a dispersion tank, After both are stirred and primarily dispersed in a dispersion tank, the obtained primary dispersion may be supplied into a continuous high-speed rotation high shear type stirring and dispersing machine.
  • the polymerization (suspension polymerization) reaction is usually carried out with stirring at a temperature of 40 to 80 ° C. for 5 to 50 hours in a polymerization can that has been degassed or replaced with an inert gas such as nitrogen gas. Since the polymer particles produced by the polymerization form an oil phase (solid phase), they are separated and removed from the aqueous phase containing the aqueous dispersion medium by, for example, known separation methods such as filtration, centrifugation, and sedimentation. The Separation of the polymer particles to be generated from the aqueous phase may be repeated while washing with water as necessary.
  • the polymer particles separated and removed from the aqueous phase containing the aqueous dispersion medium may contain all of the inorganic compound during suspension polymerization or after polymerization, if necessary.
  • the adhesion amount of the inorganic compound of the thermally foamable microsphere can be adjusted.
  • the adhesion amount of the inorganic compound adhering to the outer shell of the polymer be 1.8% by mass or less, all or a part of the inorganic compound is removed from the outer shell of the polymer after suspension polymerization. It is preferable.
  • the method for adjusting the adhesion amount of the inorganic compound that removes all or part of the inorganic compound from the outer shell of the polymer is not particularly limited as long as the intended purpose can be achieved. From the viewpoint of ensuring the adjustment, etc., it is preferable to remove all or part of the inorganic compound from the outer shell of the polymer by pH adjustment or mechanical treatment.
  • Examples of the method for removing all or a part of the inorganic compound from the outer shell of the polymer by adjusting the pH include alkali treatment or acid treatment, and the kind of inorganic compound and the amount of inorganic compound adhered before pH adjustment.
  • the optimum conditions can be selected in consideration. Specifically, the type, concentration, treatment temperature and / or treatment time of the alkali treatment solution or acid treatment solution are optimized. For example, when the inorganic compound contains silica, which is an inorganic compound containing silicon, it is preferable to perform an alkali treatment.
  • polymer particles to which silica that is an inorganic compound is attached It is immersed in an alkali treatment solution at a predetermined temperature, for example, an alkaline aqueous solution having a pH of 12 or a sodium hydroxide aqueous solution having a concentration of 5% by mass for a predetermined time while gently stirring (for example, about 300 rpm).
  • an alkali treatment solution for example, an alkaline aqueous solution having a pH of 12 or a sodium hydroxide aqueous solution having a concentration of 5% by mass for a predetermined time while gently stirring (for example, about 300 rpm).
  • an alkali treatment solution for example, an alkaline aqueous solution having a pH of 12 or a sodium hydroxide aqueous solution having a concentration of 5% by mass for a predetermined time while gently stirring (for example, about 300 rpm).
  • the inorganic compound contains magnesium hydroxide, which is an inorganic compound containing magnesium, it is preferable to
  • polymer particles to which magnesium hydroxide which is an inorganic compound adheres Is immersed in an acid treatment solution at a predetermined temperature, for example, a hydrochloric acid aqueous solution having a pH of 3.0, for a predetermined time while gently stirring.
  • a predetermined temperature for example, a hydrochloric acid aqueous solution having a pH of 3.0
  • the temperature of the immersion treatment is usually 5 to 80 ° C., preferably 15 to 50 ° C., more preferably normal temperature
  • the immersion time (treatment time) is usually 5 to 240 minutes, preferably 10 to 220 minutes, more preferably 20 to 200 minutes.
  • the polymer particles with the inorganic compound attached are poured into water at a predetermined temperature using a stirrer such as a homogenizer.
  • a stirrer such as a homogenizer.
  • a method of vigorously stirring for a predetermined time may be mentioned.
  • the temperature and time for performing the mechanical treatment are the same as those described above for pH adjustment, and the stirring treatment conditions are not particularly limited, but are usually 1.3 to 4.7 m / sec.
  • the stirring blade diameter when the stirring blade diameter is 30 mm, this corresponds to a stirring speed of 800 to 3000 rpm.
  • the peripheral speed is 1.6 to 3.9 m / second (for example, when the stirring blade diameter is 30 mm, the stirring speed is It corresponds to 1000 to 2500 rpm).
  • thermoly foamable microsphere of the present invention is then subjected to a treatment following the adjustment when the amount of the inorganic compound adhering to the outer shell of the polymer is adjusted as necessary. It is obtained by separating and removing from an aqueous phase containing a liquid or an aqueous dispersion medium, and usually drying at a relatively low temperature such that the blowing agent is not gasified by thermal expansion.
  • the obtained thermally foamable microspheres are heat-treated at a temperature not higher than the foaming start temperature as necessary, so that the foamed particles including the uniformity of foaming (thermal expansion) and the blower residual rate of the foamed particles can be used.
  • the foaming start temperature of the thermally foamable microsphere after the heat treatment can be adjusted.
  • the heat treatment is usually at a temperature 3 to 90 ° C. lower than the foaming start temperature of the heat-foamable microsphere before the heat treatment, often 5 to 70 ° C., usually 10 seconds to 15 minutes, often 30 seconds to 10 It is possible to select appropriately according to the condition of minutes.
  • the form for implementing this invention can also take the following structures.
  • a thermally foamable microsphere in which a foaming agent is enclosed in the outer shell of a polymer, and the thermally foamable microsphere is freely foamed on a glass plate at a temperature higher than the foaming start temperature.
  • a thermally foamable microsphere wherein a residual ratio of the expanded particles measured by a blower test on the glass plate is 3% by mass or more based on a total mass of the expanded particles before the blower test.
  • the thermally foamable microsphere according to [1] wherein the adhesion amount of the inorganic compound adhering to the outer shell of the polymer is 1.8% by mass or less.
  • the polymer further contains, as a monomer unit, at least one selected from the group consisting of vinylidene chloride, acrylic acid ester, methacrylic acid ester, styrene, acrylic acid, methacrylic acid, and vinyl acetate.
  • Suspension polymerization of a polymerizable mixture containing at least a foaming agent and a polymerizable monomer in an aqueous dispersion medium containing a dispersion stabilizer containing an inorganic compound, and a foaming agent in the outer shell of the resulting polymer Is a method for producing a thermally foamable microsphere in which is encapsulated, A method for producing thermally foamable microspheres, comprising a step of removing all or part of an inorganic compound from the outer shell of a polymer during or after suspension polymerization.
  • a method for measuring the characteristics of the thermally foamable microspheres is as follows.
  • blower residual rate of expanded particles The blower residual ratio of the expanded particles was measured by the following method. That is, as a sample, 0.01 g of thermally foamable microspheres preliminarily heat-treated at a temperature of 150 ° C. for 5 minutes was placed on the upper surface of a glass plate (preparation: length 75 mm, width 25 mm, thickness 1 mm, washed and dried with acetone). Placed (range of placing sample: 40 mm in length and 18 mm in width), and allowed to foam freely at 180 ° C. for 3 minutes.
  • the adhesion amount of the inorganic compound adhering to the outer shell of the polymer of the thermally foamable microsphere was measured by the dry ashing method (unit: mass%).
  • the measurement procedure is as follows. That is, as a sample, about 0.5 g of thermally foamable microspheres are put in a magnetic crucible (diameter 40 mm, height 35 mm), covered, heated for 1 hour with a heater at a temperature of about 250 ° C., and lightly carbonized. It was. Next, the magnetic crucible was placed in a muffle furnace having a temperature of 700 ° C. and incinerated for 1 hour. The amount of ash (unit: mass%) was calculated from the difference in mass before and after ashing, and the amount of inorganic compound adhered (unit: mass%) was taken as the ratio to the mass of the thermally foamable microspheres before ashing.
  • the average particle diameter (D50) of the thermally foamable microspheres (hereinafter sometimes referred to as “D50”) was measured by the method described above using SALD-3100 manufactured by Shimadzu Corporation. Calculated.
  • the foaming start temperature of the thermally foamable microsphere was measured using a thermomechanical analyzer TMA / SDTA840 model manufactured by METTLER TOLEDO. That is, using 0.25 mg of thermally foamable microspheres as a sample, the temperature was increased at a rate of temperature increase of 5 ° C./min, and the temperature at which the displacement of the sample height in the container started was determined as the foaming start temperature (Ts (Unit: ° C).
  • Example 1 (Preparation of aqueous dispersion medium containing dispersion stabilizer) 42 g of colloidal silica as a dispersion stabilizer (210 g of silica dispersion with a solid content of 20% by mass), 4.9 g of diethanolamine-adipic acid condensation product (acid value 75 mgKOH / g) as an auxiliary stabilizer (with a solid content of 50% by mass) Dispersion 9.8 g) and 0.84 g of polymerization assistant sodium nitrite were charged into 4984 g of salt water (NaCl concentration 25% by mass) to prepare an aqueous dispersion medium containing a dispersion stabilizer. The pH was adjusted by adding 49 g of hydrochloric acid so that the pH of the aqueous dispersion medium containing this dispersion stabilizer was 3.5.
  • ethylene glycol dimethacrylate which is a crosslinkable monomer
  • V-60 2,2′-azobisisobutyronitrile
  • aqueous dispersion medium containing the dispersion stabilizer and the polymerizable mixture are stirred and mixed using a batch-type high-speed emulsifier / disperser (PRIMIX AUTO MIXER 40) to form fine droplets of the polymerizable mixture. Grained.
  • the obtained aqueous dispersion medium containing fine droplets of the polymerizable mixture was charged into a polymerization can equipped with a stirrer (volume: 10 L), suspended at a temperature of 60 ° C. for 13.5 hours, and then at a temperature of 70 ° C. for 10.5 hours.
  • the suspension was polymerized.
  • the produced polymer particles were filtered using a Nutsche (Buchner funnel) and washed with water.
  • the treated polymer particles are separated from the sodium hydroxide aqueous solution while being filtered using a Nutsche, washed with 120 g of pure water, and then washed at a temperature of 40 ° C. using a speed dryer manufactured by Matsui Seisakusho Co., Ltd. After drying for a while, the dried product was sieved with a 100-mesh sieve to obtain a thermally foamable microsphere having an average particle diameter (D50) of 46 ⁇ m and a foaming start temperature of 207 ° C.
  • D50 average particle diameter
  • the heat-foamable microspheres were heat-treated in advance in a gear oven manufactured by Toyo Seiki Seisakusho Co., Ltd. at a temperature of 150 ° C. for 5 minutes.
  • the average particle size (D50) was 46 ⁇ m and the foaming start temperature was 155 ° C.
  • the foamed particles were obtained by placing 0.01 g of thermally foamable microspheres on a glass plate (preparation) as a base material and heating them in a gear oven at a temperature of 180 ° C. for 3 minutes for free foaming. .
  • thermally foamable microspheres and foamed particles About the obtained thermally foamable microspheres and foamed particles, the blower remaining rate of the foamed particles, the amount of silica (inorganic compound) attached to the thermally foamable microspheres (hereinafter collectively referred to as “thermally foamable microspheres, etc.
  • Table 1 shows together with the time for adjusting the adhesion amount of the inorganic compound (hereinafter sometimes referred to as “treatment time”).
  • Example 2 In the adjustment of the adhesion amount of the inorganic compound, except that the immersion treatment was performed for 120 minutes, the heat-foamable microsphere by heat treatment in the same manner as in Example 1 and the heat-foamable microsphere were similarly treated. Expanded particles were obtained by free foaming (hereinafter referred to as “thermally expandable microspheres and expanded particles by heat treatment and free foaming similar to Example 1”). Table 1 shows the characteristics of the thermally foamable microspheres together with the treatment time.
  • Example 3 In adjusting the adhesion amount of the inorganic compound, a sodium hydroxide aqueous solution having a concentration of 5% by mass was used in place of the sodium hydroxide aqueous solution adjusted to pH 12 (the immersion treatment in the sodium hydroxide aqueous solution was performed at room temperature for 60 minutes. Except that, thermally expandable microspheres and expanded particles by heat treatment and free foaming similar to Example 1 were obtained. Table 1 shows the characteristics of the thermally foamable microspheres together with the treatment time.
  • Example 4 In the adjustment of the adhesion amount of the inorganic compound, heat-expandable microspheres and expanded particles obtained by the same heat treatment and free foaming as in Example 3 were obtained except that the immersion treatment was performed for 120 minutes. Table 1 shows the characteristics of the thermally foamable microspheres together with the treatment time.
  • Example 5 In the adjustment of the adhesion amount of the inorganic compound, heat-expandable microspheres and expanded particles by heat treatment and free foaming similar to those of Example 3 were obtained except that the immersion treatment was performed for 180 minutes. Table 1 shows the characteristics of the thermally foamable microspheres together with the treatment time.
  • Example 6 The heat-foamable microsphere obtained in Example 5 was replaced with a glass plate (preparation) as a base material, and filter paper (ADVANTEC (registered trademark) quantitative filter paper 5A manufactured by Toyo Roshi Kaisha, Ltd.) was used as the base material. Except that, thermally foamable microspheres and foamed particles (foamed particles on the substrate) by heat treatment and free foaming similar to Example 5 were obtained. Table 1 shows the results of measuring the blower residual rate of the expanded particles on the expanded paper substrate.
  • filter paper ADVANTEC (registered trademark) quantitative filter paper 5A manufactured by Toyo Roshi Kaisha, Ltd.
  • Example 7 The heat-foamable microsphere obtained in Example 5 was replaced with a glass plate (preparation) as a base material, and an aluminum pan (diameter 65 mm) was used as the base material. Thermally foamable microspheres and foamed particles (foamed particles on the substrate) were obtained by heat treatment and free foaming. Table 1 shows the results of measuring the blower residual rate of the expanded particles on the expanded particles on the aluminum substrate.
  • Example 8 The heat-foamable microspheres obtained in Example 5 were replaced with a glass plate (preparation) as a base material, and a polyethylene terephthalate film [Lumirror (registered trademark) P60 manufactured by Toray Industries, Inc., thickness 12 ⁇ m as a base material]. Hereinafter, it may be described as “PET film”. ] Were used, and thermally foamable microspheres and foamed particles (foamed particles on the substrate) were obtained by the same heat treatment and free foaming as in Example 5. Table 1 shows the results of measuring the blower residual rate of the foamed particles for the foamed particles on the PET film substrate.
  • Example 9 The heat-foamable microspheres obtained in Example 5 were replaced with a glass plate (preparation) as a base material and exposed as a base material (peace: 100% cotton, manufactured by Tokyo Textile Wholesale Trade Co., Ltd.) Except that m 2 ) was used, heat-expandable microspheres and expanded particles (expanded particles on the substrate) obtained by the same heat treatment and free expansion as in Example 5 were obtained.
  • Table 1 shows the results of measuring the blower residual rate of the foamed particles on the foamed particles on the cloth substrate.
  • Example 10 After 0.01 g of glass fiber (length 20 mm, ⁇ 20 ⁇ m) is coated with 0.5 g of the heat-foamable microspheres obtained in Example 5, heat treatment is performed in the gear oven in advance at a temperature of 150 ° C. for 5 minutes. Then, by heating in a gear oven at a temperature of 180 ° C. for 3 minutes for free foaming, a molded article (indefinite shape) containing glass fiber as a base material and foamed particles was obtained. Table 1 shows the results of measuring the blower residual rate of the expanded particles of the molded product containing the expanded particles.
  • Example 11 In the adjustment of the adhesion amount of inorganic compounds, instead of the treatment of immersing in an aqueous sodium hydroxide solution adjusted to pH 12, a homogenizer (batch type high-speed emulsification / dispersing machine) is used to remove the thermally foamable microspheres in 400 g of water.
  • Table 1 shows the characteristics of the thermally foamable microspheres together with the treatment time.
  • Example 12 In the adjustment of the adhesion amount of the inorganic compound, heat-expandable microspheres and expanded particles by heat treatment and free foaming similar to those of Example 11 were obtained except that the stirring process using a homogenizer was performed for 120 minutes. Table 1 shows the characteristics of the thermally foamable microspheres together with the treatment time.
  • thermoly foamable microsphere in which a foaming agent is enclosed in the outer shell of a polymer, the thermally foamable microsphere being freely foamed on a glass plate at a temperature higher than the foaming start temperature.
  • the heat-expandable microspheres of Examples 1 to 5, 11 and 12 in which the blower residual ratio of the expanded particles is 3% by mass or more with respect to the total mass of the expanded particles before the blower test are adhesive to the glass plate.
  • the foamed particles obtained by thermal foaming were excellent in adhesiveness between the foamed particles and the foamed particles, and were thermally foamable microspheres adhered to the foamed particles and other base materials.
  • thermally foamable microspheres of Example 5 are obtained by expanding the foamed particles obtained by thermal foaming from Examples 6 to 10 using filter paper, aluminum dish, PET film, bleached cloth or glass fiber as a substrate. It was confirmed that the foamed microspheres can be bonded to each other and to various other substrates.
  • the expanded particles obtained by thermal expansion have the expanded foams. It turned out that it is not a thing excellent in the adhesiveness with respect to particle
  • Examples 2, 4, 5, and 12 are achieved by adjusting the method of removing silica (inorganic compound) by adjusting pH or by mechanical treatment to control the glass plate adhesion strength of the expanded particles.
  • thermally foamable microsphere having an excellent adhesion with a blower residual ratio of foamed particles of 15% by mass or more
  • heat containing a fibrous, particulate, sheet or bulk reinforcing material is obtained.
  • a molded article containing expandable microspheres, or a molded article containing expanded particles obtained by foaming a molded article containing the thermally foamable microspheres It is possible to obtain a molded product having a strong bond between the bulk-like reinforcing material and the foamed particles, with less dropout of the foamed particles, and good mechanical properties.
  • the present invention relates to a thermally foamable microsphere in which a foaming agent is enclosed in an outer shell of a polymer, and the thermally foamable microsphere is freely foamed on a glass plate at a temperature higher than a foaming start temperature.
  • the thermal foamable micros described above wherein the residual ratio of the expanded particles measured by the blower test on the glass plate is 3% by mass or more based on the total mass of the expanded particles before the blower test Because of the fairness, the foamed particles obtained by thermal foaming and the adhesiveness between the foamed particles and other materials are excellent, the foamed particles are less likely to fall off, and the resulting molded product has good mechanical properties. Since foamable microspheres can be provided, the industrial applicability is high.
  • the present invention is a method in which a polymerizable mixture containing at least a foaming agent and a polymerizable monomer is subjected to suspension polymerization in an aqueous dispersion medium containing a dispersion stabilizer.
  • Thermal foamability that can be easily produced by the above-described method for producing thermally foamable microspheres for producing thermally foamable microspheres in which a foaming agent is enclosed. Since the manufacturing method of a microsphere can be provided, industrial applicability is high.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Dispersion Chemistry (AREA)
  • Polymerisation Methods In General (AREA)
  • Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)

Abstract

L'invention concerne des microsphères thermo expansibles, lesquelles présentent une excellente adhésivité entre les particules d'expansion formées ou entre ces particules d'expansion et une autre substance, pour lesquelles la perte de particules d'expansion est faible, et lesquelles permettent d'obtenir un produit moulé avec de bonnes caractéristiques mécaniques. Plus spécifiquement, un agent d'expansion est encapsulé dans l'enveloppe externe polymère de ces microsphères thermo expansibles, et le taux résiduel de particules d'expansion ayant provoqué l'expansion des microsphères, mesuré par un test à l'air soufflé sur une plaque de verre, est égal ou supérieur à 3% en masse.
PCT/JP2015/083875 2014-12-02 2015-12-02 Microsphères thermo expansibles adhésives et procédé de production de celles-ci Ceased WO2016088800A1 (fr)

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JP2014-243770 2014-12-02

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20240031336A (ko) 2021-07-05 2024-03-07 마쓰모토유시세이야쿠 가부시키가이샤 중공 입자 및 그 용도

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62280238A (ja) * 1986-05-30 1987-12-05 Sekisui Plastics Co Ltd 発泡性樹脂粒子の製造方法
JPS63125538A (ja) * 1986-11-14 1988-05-28 Japan Styrene Paper Co Ltd 改質された高密度ポリエチレン系樹脂発泡粒子
JPH04154847A (ja) * 1990-10-19 1992-05-27 Sekisui Plastics Co Ltd 難燃性発泡性樹脂粒子の製造法
JP2006117842A (ja) * 2004-10-22 2006-05-11 Asahi Kasei Life & Living Corp ポリオレフィン系樹脂発泡粒子及びその型内成形体
WO2006083041A1 (fr) * 2005-02-07 2006-08-10 Kureha Corporation Microsphère moussable thermiquement, procédé de fabrication idoine et composition
JP2012167286A (ja) * 2012-05-17 2012-09-06 Kureha Corp 熱発泡性マイクロスフェアー及びその製造方法
WO2015098586A1 (fr) * 2013-12-26 2015-07-02 松本油脂製薬株式会社 Procédé permettant de produire des microsphères thermiquement expansibles et utilisation de ce dernier

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62280238A (ja) * 1986-05-30 1987-12-05 Sekisui Plastics Co Ltd 発泡性樹脂粒子の製造方法
JPS63125538A (ja) * 1986-11-14 1988-05-28 Japan Styrene Paper Co Ltd 改質された高密度ポリエチレン系樹脂発泡粒子
JPH04154847A (ja) * 1990-10-19 1992-05-27 Sekisui Plastics Co Ltd 難燃性発泡性樹脂粒子の製造法
JP2006117842A (ja) * 2004-10-22 2006-05-11 Asahi Kasei Life & Living Corp ポリオレフィン系樹脂発泡粒子及びその型内成形体
WO2006083041A1 (fr) * 2005-02-07 2006-08-10 Kureha Corporation Microsphère moussable thermiquement, procédé de fabrication idoine et composition
JP2012167286A (ja) * 2012-05-17 2012-09-06 Kureha Corp 熱発泡性マイクロスフェアー及びその製造方法
WO2015098586A1 (fr) * 2013-12-26 2015-07-02 松本油脂製薬株式会社 Procédé permettant de produire des microsphères thermiquement expansibles et utilisation de ce dernier

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20240031336A (ko) 2021-07-05 2024-03-07 마쓰모토유시세이야쿠 가부시키가이샤 중공 입자 및 그 용도

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