CN102256695B

CN102256695B - Process for producing hollow microspheres and process for producing porous molded ceramic

Info

Publication number: CN102256695B
Application number: CN200980150780.5A
Authority: CN
Inventors: 江尻哲男; 佐竹义克
Original assignee: Kureha Corp
Current assignee: Kureha Corp
Priority date: 2008-12-18
Filing date: 2009-11-05
Publication date: 2014-08-06
Anticipated expiration: 2029-11-05
Also published as: WO2010070987A1; KR20110106359A; KR101278410B1; CN102256695A; JP5588880B2; JPWO2010070987A1

Abstract

The invention provides a process for producing hollow microspheres which comprises: a step (1) in which heat-expandable microspheres having a microcapsular structure comprising a shell formed from a thermoplastic resin and, encapsulated therein, a blowing agent capable of gasifying or generating a gas and a solid material having an average particle diameter or average major-axis length smaller than the average particle diameter of the heat-expandable microspheres are dispersed in a liquid dispersion medium to prepare a slurry; and a step (2) in which the heat-expandable microspheres are heated in the slurry to soften and thermally expand the shells thereof, thereby forming hollow microspheres having the solid material adherent to the surface of the softened shells.

Description

The manufacture method of the manufacture method of hollow microsphere and porous ceramic formed body

Technical field

The present invention relates to the manufacture method that the solid materials such as particulate, microfibre are attached to the hollow microsphere of case surface securely.In addition the invention still further relates to, the manufacture method of the porous ceramic formed body using this hollow microsphere as Porous forming agent.

Background technology

Heat-expandable microsphere has has enclosed the gasifiable microcapsule structure that maybe can produce the blowing agent of gas and obtain in the shell being formed by thermoplastic resin.Heat-expandable microsphere is also referred to as heat-expandable macrosphere or thermal expansivity microcapsules.If heat-expandable microsphere is heated to the temperature more than softening point of the thermoplastic resin that forms shell, the thermal expansion due to the gasification of blowing agent itself or the thermal decomposition gas of blowing agent.By the thermal expansion of heat-expandable microsphere, formed the hollow microsphere as ducted body particle.

The thermal expansion being caused by the heating of heat-expandable microsphere is commonly referred to as foamable or foaming.Heat-expandable microsphere also can be used as separately independently foaming body particle and forms hollow microsphere after foaming.On the other hand, the foamable polystyrene particle that has flooded liquid blowing agent is in mould, to make its foamable by being filled in, thereby forms the expanded moldings that foaming body particle merges integrated regulation shape, rather than heat-expandable microsphere.

Hollow microsphere is also referred to as baton round or plastic hollow pearl.Heat-expandable microsphere can form low-gravity hollow microsphere by thermal expansion.Therefore, for lightweight, give the objects such as design, heat-expandable microsphere is added in the various base materials such as China ink, coating, plastics.

If the purposes field of heat-expandable microsphere expands, and require the high performance in each purposes field, to the level that requires of heat-expandable microsphere, also can improve.As to heat-expandable microsphere require one of characteristic, in the time of can being set forth in foamable and after foaming, the cohesion being caused by the fusion between foaming body particle is few, even hardly cohesion.

Heat-expandable microsphere not only can be fitted in the base materials such as China ink, coating, plastics under the state of not foaming, and usually under the state after foaming, coordinates.Foaming body particle (hollow microsphere) utmost point light weight that heat-expandable microsphere foaming forms, for example, if it is included in coating, can realize the lightweight of coated object.Yet, if foaming body particle condenses each other, be sometimes difficult to mix with the base material such as coating, even when mixing, can destroy foaming body particle.

As the method that prevents from condensing between foaming body particle, considered to come by solia particles such as inorganic particles, organic fine particles the method for the case surface of the heat-expandable microsphere that coating do not foam.Yet, make solia particle be attached to equably the case surface of heat-expandable microsphere, and then strictly to control its adhesion amount be extremely difficult.If can not make solia particle be attached to equably the case surface of heat-expandable microsphere, be difficult to uniform foaming.If the adhesion amount of solia particle is very few, the fusion in the time of can not preventing foamable fully.If the adhesion amount of solia particle is too much, be difficult to foaming, in the worst case, sometimes can not foam.

The foaming body particle (hollow microsphere) of heat-expandable microsphere, due to utmost point light weight, is therefore difficult to be applicable to new purposes sometimes.For example, disclosed in TOHKEMY 2007-39333 communique (patent documentation 1), porous ceramic formed body is manufactured by the following method: the formed body that the mixture that contains ceramic raw material and Porous forming agent is shaped to regulation shape, then, this formed body is burnt till.If use the foaming body particle (hollow microsphere) of heat-expandable microsphere as Porous forming agent, can obtain accordingly with the size of foaming body particle the porous ceramic formed body with required porous structure.

Yet due to the low-gravity hollow microsphere as foaming body particle and excessive as the difference in specific gravity between the hyperbaric ceramic raw material of inorganic material, it is extremely difficult therefore disperseing equably.Therefore,, if use hollow microsphere as Porous forming agent, be difficult to obtain the porous ceramic formed body with uniform porous structure.Porous ceramic formed body can be at diesel particulate filter device (the Diesel Particulate Filter of the particle-like substance for example comprising as the exhaust for reducing diesel engine; DPF) in purposes, use, if but porous structure is inhomogeneous, can not bring into play the sufficient performance as filter.

The in the situation that of manufacturing heat-expandable microsphere by suspension polymerization in aqueous dispersion medium, if used, contain the inorganic particles such as colloidal silica as the aqueous dispersion medium of dispersion stabilizer, the case surface of the heat-expandable microsphere that generated will be adhered to inorganic particles.Yet because the adhesive force between inorganic particles and heat-expandable microsphere is little, the strong firm attachment of inorganic particles of the amount that is therefore difficult to make to be enough to prevent that foaming body particle from merging is each other in the case surface of heat-expandable microsphere.

If in the recovery process after polymerization finishes, the reactant mixture of the heat-expandable microsphere containing generating is to some extent filtered, washed, the inorganic particles using as dispersion stabilizer comes off in a large number.The a small amount of inorganic particles of case surface that is attached to the heat-expandable microsphere of recovery also easily departs from simply in treatment process thereafter.

If increase the amount of the dispersion stabilizers such as colloidal silica, can increase the adhesion amount of inorganic particles to the case surface of heat-expandable microsphere, and can make this proportion increase to a certain degree.Yet in the method, the disengaging problem of the inorganic particles in washing procedure, treatment process thereafter cannot solve.And if adopt such method that inorganic particles is increased the adhesion amount of the case surface of heat-expandable microsphere, the average grain diameter that can produce the heat-expandable microsphere of gained diminishes, particle diameter distributes becomes large such problem.

In order to give various functions to hollow microsphere, the method that the solia particle that makes to have various functions is attached to its case surface is effective.Yet the solia particle that makes to have various functions is attached to the case surface of hollow microsphere securely, and it is extremely difficult problem that its adhesion amount is controlled in required scope.

In the past, as making solia particle be attached to the method for the case surface of heat-expandable microsphere, some methods had been proposed.In TOHKEMY 2002-363537 communique (patent documentation 2), proposed, in water system decentralized medium, the polymerism mixture that contains polymerizable monomer and blowing agent is carried out to suspension polymerisation under the existence of organo-silicon compound with polymerisable reactive group, thereby manufacture the method for heat-expandable microsphere.According to the method for patent documentation 2, by the effect of organo-silicon compound, can make the various solia particles such as colloidal silica be attached to the case surface of heat-expandable microsphere.In the method, need to use expensive organo-silicon compound, and the case surface that will make a large amount of hyperbaric solia particles be attached to securely the foaming body particle after foaming is difficult.

In TOHKEMY 2003-112039 communique (patent documentation 3), No. 2005/049698 brochure of International Publication (patent documentation 4) and TOHKEMY 2006-213930 communique (patent documentation 5), disclose, heat-expandable microsphere and solia particle have been mixed to be manufactured on the method that case surface is attached with the heat-expandable microsphere of solia particle.Yet, in simple mixed method, can not make solia particle be attached to securely the case surface of heat-expandable microsphere, in treatment process thereafter, solia particle comes off simply.

About making solia particle be attached to the method for case surface of the foaming body particle (hollow microsphere) of heat-expandable microsphere, some methods have also been proposed.In Japanese kokai publication hei 3-273037 communique (patent documentation 6), following method being disclosed: in the moist press cake of heat-expandable microsphere, mixes granular or fibrous solid, be dried until moisture content becomes and be less than 1 % by weight, then carry out foamable.Yet disclosed method is difficult to suppress heat-expandable microsphere cohesion and the premature expansion in drying process in patent documentation 6.

In TOHKEMY 2001-98079 communique (patent documentation 7), proposed, made colloidal calcium carbonate be attached to the method for the foaming body particle surface of heat-expandable microsphere together with surface conditioning agent or dispersant.According to disclosed method in patent documentation 7, although can suppress foaming body particle, disperse in air, be difficult to make solia particle to be attached to securely the case surface of foaming body particle.

In TOHKEMY 2006-35092 communique (patent documentation 8), proposed, the aqueous dispersion of heat-expandable microsphere is mixed with inorganic particles, then carry out Separation of Solid and Liquid and after forming filter cake or Separation of Solid and Liquid, be dried and form powder, then, make heat-expandable microsphere add the method for thermal expansion.According to disclosed method in patent documentation 8, although can prevent that foaming body particle from dispersing, be difficult to suppress heat-expandable microsphere cohesion and premature expansion.

In TOHKEMY 2006-137926 communique (patent documentation 9), proposed, the moisture filter cake using the acrylic acid series polymeric compounds obtaining with dispersion stabilizer particles such as colloidal silicas as the heat-expandable microsphere of shell not carrying out dry in the situation that, add the method that hollow microsphere is manufactured in thermal expansion.Therefore disclosed method in patent documentation 9, owing to not needing drying process, can suppress that hollow microsphere merges each other, premature expansion, and if in moisture filter cake hybrid solid particulate, can obtain the mixture of hollow microsphere and solia particle.Yet, in order to make moisture filter cake foamable, need to use powder mixer to heat under mechanical shearing, therefore easily cause that heat-expandable microsphere, hollow microsphere merge, breakage.In addition, in the method for patent documentation 9, during due to polymerization, dispersion stabilizer particle is attached to the case surface of heat-expandable microsphere, be therefore difficult to make other solia particle to adhere to securely, and the dispersion stabilizer particle adhering to easily comes off.

Patent documentation 1: TOHKEMY 2007-39333 communique

Patent documentation 2: TOHKEMY 2002-363537 communique

Patent documentation 3: TOHKEMY 2003-112039 communique

Patent documentation 4: No. 2005/049698 brochure of International Publication

Patent documentation 5: TOHKEMY 2006-213930 communique

Patent documentation 6: Japanese kokai publication hei 3-273037 communique

Patent documentation 7: TOHKEMY 2001-98079 communique

Patent documentation 8: TOHKEMY 2006-35092 communique

Patent documentation 9: TOHKEMY 2006-137926 communique

Summary of the invention

Problem of the present invention is to provide does not need complicated operation, do not need to use expensive compound and heat-expandable microsphere does not occur and merge each other and premature expansion, and the solid material such as particulate, microfibre of manufacturing organic or inorganic is attached to the method for the hollow microsphere of case surface securely.

Another problem of the present invention is to provide hollow microsphere as the purposes of Porous forming agent etc.More specifically, another problem of the present invention is to provide and uses the hollow microsphere obtain by said method as the manufacture method of the porous ceramic formed body of Porous forming agent.

The present inventors conduct in-depth research in order to realize above-mentioned problem, found that, if adopted, heat-expandable microsphere and solid material are dispersed in liquid dispersion medium, form slurry, in this slurry, be blown into the methods such as heating water steam and make heat-expandable microsphere foamable (thermal expansion), the case surface that solid material has softened when foamable is adhered to securely.

By selecting adhesion amount, the kind of solid material, can obtain the hollow microsphere with various functions.For example, make hyperbaric solid material be attached to case surface and hollow microsphere, because particle integral body be high specific gravity, so can be suitable as the Porous forming agent use of the manufacture raw material of porous ceramic formed body.

Can think that the slurry that is dispersed with heat-expandable microsphere and solid material is not suitable for foaming by the heating under hot conditions, but can distinguish: method that is blown into heating water steam by employing etc. makes heat-expandable microsphere foamable, the case surface of now, having softened can be adhered to fine solid material securely.The present invention completes based on these understanding.

According to the present invention, a kind of manufacture method that has the hollow microsphere of solid material in shell surface attachment is provided, described manufacture method is characterised in that, comprises following operation 1 and operation 2:

(1) operation 1, the solid material that makes following heat-expandable microsphere and average grain diameter or average major diameter be less than the average grain diameter of this heat-expandable microsphere is dispersed in liquid dispersion medium, thereby modulation slurry, described heat-expandable microsphere have in the shell being formed by thermoplastic resin, has enclosed the gasifiable blowing agent that maybe can produce gas and microcapsule structure, and can carry out thermal expansion by heating and form hollow microsphere; And

(2) operation 2, in this slurry, heat this heat-expandable microsphere, make its shell softening, and the gasification by this blowing agent or the gas that produced by this blowing agent and thermal expansion, thus, be formed on the hollow microsphere that the case surface of having softened is attached with this solid material.

In addition, according to the present invention, provide a kind of manufacture method of porous ceramic formed body, it is characterized in that, comprise following operation a～c:

Operation a, mixes to come modulating mixture by ceramic raw material with Porous forming agent;

Operation b, is shaped to this mixture the formed body of regulation shape; And

Operation c, carries out this formed body maintenance or burns till,

In described manufacture method, as this Porous forming agent, use obtains by above-mentioned manufacture method, case surface is attached with the hollow microsphere of solid material.

Manufacturing method according to the invention, can provide does not need complicated operation, does not need to use expensive compound, and, do not cause that heat-expandable microsphere merges each other, premature expansion, manufacture the method that the solid materials such as particulate, microfibre are attached to the hollow microsphere of case surface securely.

The method according to this invention, due to the heat-expandable microsphere foaming that makes freely to disperse in slurry, the heat-expandable microsphere while therefore foaming is difficult to merge each other, and the hollow microsphere obtaining after foaming is also difficult to merge each other.The method according to this invention, softening case surface owing to making solid material be attached to foamable, therefore can not suppress heat-expandable microsphere foaming, and, the case surface that can make solid material be attached to securely to soften.By change, be dispersed in amount, the kind of the solid material in slurry, can at random control amount, the kind of the solid material that is attached to case surface.

If as solid material, use hyperbaric inorganic particles, and by stirring slurry, each composition is disperseed equably on one side, make heat-expandable microsphere foamable on one side, in case surface, adhere to securely hyperbaric inorganic particles, thus, can obtain the high hollow microsphere of the whole proportion of particle.The hollow microsphere that proportion has improved can mechanically evenly mix by the hyperbaric particle such with ceramic raw material.Therefore,, if the hollow microsphere that use case surface is attached with high specific gravity solid material is as Porous forming agent, can manufacture the porous ceramic formed body with even porous structure.

Accompanying drawing explanation

Fig. 1 is the key diagram that shows the thermal expansion of heat-expandable microsphere.

Fig. 2 shows that case surface of the present invention is attached with the key diagram of manufacture method of the hollow microsphere of solid material.

Description of reference numerals

1 heat-expandable microsphere

2 shells

3 blowing agents

101 hollow microspheres

102 shells

103 hollows

21 containers

22 liquid dispersion mediums

23 solid materials

The specific embodiment

As the heat-expandable microsphere using in the present invention, so long as have, in the shell being formed by thermoplastic resin, enclosed the gasifiable microcapsule structure that maybe can produce the blowing agent of gas and obtain, and can carry out the heat-expandable microsphere that thermal expansion forms hollow microsphere by heating, can obtain by any manufacture method.

As shown in Fig. 1 (a), heat-expandable microsphere 1 has the structure that the shell 2 by being made by thermoplastic resin has been enclosed blowing agent 3.If heat-expandable microsphere 1 is heated to the temperature more than softening point of the thermoplastic resin that forms its shell 2, as shown in Fig. 1 (b), due to the gasification of blowing agent 3 or the gas that produced by blowing agent and thermal expansion is the hollow microsphere 101 of hollow 103 thereby obtained in the shell 102 after expanding.

Generally speaking, heat-expandable microsphere can, by aqueous dispersion medium, carry out the polymerizable monomer mixture that at least contains blowing agent and polymerizable monomer the method for suspension polymerisation and manufacture.By suspension polymerisation, the polymer being generated by the polymerization of polymerizable monomer (thermoplastic resin) forms shell, generates and has the heat-expandable microsphere of having enclosed the structure of blowing agent in this shell.

As polymerizable monomer, conventionally use free-radical polymerised polymerizable monomer.As the concrete example of polymerizable monomer, can enumerate the nitriles such as acrylonitrile, methacrylonitrile, α-chloro-acrylonitrile, α-ethoxy propylene nitrile, anti-maleic nitrile is monomer; The carboxylic monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid; The acrylic ester monomers such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, isobornyl acrylate, cyclohexyl acrylate, benzyl acrylate, β-carboxy acrylic ester; The methacrylate ester monomers such as methyl methacrylate, EMA, n-BMA, isobutyl methacrylate, Tert-butyl Methacrylate, isobornyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, β-carboxyl methacrylate; Vinylidene chloride; Vinyl acetate; The styrenic monomers such as styrene, AMS, chlorostyrene; The acrylamide such as acrylamide, Methacrylamide monomer; The maleimides such as N-phenylmaleimide, N-(2-chlorphenyl) maleimide, N-N-cyclohexylmaleimide, N-lauryl maleimide are monomer.

For heat-expandable microsphere, the polymer that forms shell is thermoplastic resin, and, preferably there is gas barrier property.From these viewpoints, preferred vinylidene chloride (being total to) polymer and (methyl) acrylonitrile (being total to) polymer, but be not limited to this.Should " (being total to) polymer " mean homopolymers and/or copolymer.Should " (methyl) acrylonitrile " mean acrylonitrile and/or methacrylonitrile.

As vinylidene chloride (being total to) polymer, can enumerate as polymerizable monomer and use independent vinylidene chloride or vinylidene chloride and can obtain (being total to) polymer with the mixture of the ethene base system monomer of its copolymerization.As can with the monomer of vinylidene chloride copolymerization, for example can enumerate acrylonitrile, methacrylonitrile, methacrylate, acrylate, styrene, vinyl acetate etc.

As 1,1-dichloroethylene (being total to) polymer, at least one monomer 0～70 quality % that preferably uses vinylidene chloride 30～100 quality % as polymerizable monomer and be selected from acrylonitrile, methacrylonitrile, acrylate, methacrylate, styrene and vinyl acetate obtains (being total to) polymer.If the copolymerization ratio of vinylidene chloride is less than 30 quality %, gas barrier property is too low, therefore not preferred.

As 1,1-dichloroethylene (being total to) polymer, more preferably use vinylidene chloride 40～80 quality %, be selected from least one monomer 0～60 quality % in acrylonitrile and methacrylonitrile and be selected from acrylate and methacrylate in the copolymer of at least one monomer 0～60 quality %.By forming the copolymer of such composition, easily design blowing temperature, and, easily realize high foamability.

The in the situation that of expectation solvent resistance, high temperature foaminess, preferably by (methyl) acrylonitrile (being total to) polymer, form shell.As (methyl) acrylonitrile (being total to) polymer, as polymerizable monomer, can enumerate and use independent (methyl) acrylonitrile or (methyl) acrylonitrile and can obtain (being total to) polymer with the ethene base system monomer of its copolymerization.As can with the ethene base system monomer of (methyl) acrylonitrile compolymer, can enumerate vinylidene chloride, acrylate, methacrylate, styrene, vinyl acetate etc.

As (methyl) acrylonitrile (being total to) polymer, preferably as polymerizable monomer, use at least one monomer 0～70 quality % that is selected from least one monomer 30～100 quality % in acrylonitrile and methacrylonitrile and is selected from vinylidene chloride, acrylate, methacrylate, styrene and vinyl acetate to obtain (being total to) polymer.If the copolymerization ratio of (methyl) acrylonitrile is less than 30 quality %, solvent resistance, heat resistance are insufficient.

(methyl) acrylonitrile (being total to) polymer, can be divided into: (being total to) polymer that usage ratio is large, blowing temperature is high of (methyl) acrylonitrile; (being total to) polymer that usage ratio is little, blowing temperature is low of (methyl) acrylonitrile.As large (being total to) polymer of the usage ratio of (methyl) acrylonitrile, can enumerate as polymerizable monomer uses at least one monomer 0～20 quality % that is selected from least one monomer 80～100 quality % in acrylonitrile and methacrylonitrile and is selected from vinylidene chloride, acrylate, methacrylate, styrene and vinyl acetate to obtain (being total to) polymer.

As little (being total to) polymer of the usage ratio of (methyl) acrylonitrile, can enumerate as polymerizable monomer uses at least one the monomer 30 quality % be selected from acrylonitrile and methacrylonitrile above and be less than 80 quality % and be selected from least one monomer in vinylidene chloride, acrylate, methacrylate, styrene and vinyl acetate and be greater than 20 quality % and following and (being total to) polymer that obtains of 70 quality %.

As (methyl) acrylonitrile (being total to) polymer, preferably use be selected from least one monomer 51～100 quality %, vinylidene chloride 0～40 quality % in acrylonitrile and methacrylonitrile and be selected from acrylate and methacrylate at least one monomer 0～48 quality % obtain (being total to) polymer.

Polymer as shell, do not comprise 1 being contemplated to be, in the situation of (being total to) polymer of 1-dichloroethylene, preferably as polymerizable monomer use be selected from least one monomer 30～100 quality % in acrylonitrile and methacrylonitrile and be selected from acrylate and methacrylate at least one monomer 0～70 quality % obtain (methyl) acrylonitrile (being total to) polymer.

As not comprising 1, other of 1-dichloroethylene (being total to) polymer, preferably as polymerizable monomer, use acrylonitrile 1～99 quality %, methacrylonitrile 1～99 quality % and be selected from acrylate and methacrylate at least one monomer 0～70 quality % and the copolymer that obtains.

In order to obtain the heat-expandable microsphere that processability, foaminess, gas barrier property, solvent resistance etc. are excellent especially, (methyl) acrylonitrile (being total to) polymer of shell preferably use acrylonitrile 20～80 quality %, methacrylonitrile 20～80 quality % and be selected from acrylate and methacrylate in the copolymer that obtains as polymerizable monomer of at least one monomer 0～20 quality %.

In order to improve foam characteristics, processing characteristics, solvent resistance, heat resistance, can merge use cross-linkable monomer together with polymerizable monomer.As cross-linkable monomer, conventionally can use the compound with 2 above carbon-to-carbon double bonds.As cross-linkable monomer, for example can enumerate, divinylbenzene, divinyl naphthalene, ethylene glycol bisthioglycolate (methyl) acrylate, diethylene glycol (DEG) two (methyl) acrylate, 1, 4-butanediol two (methyl) acrylate, 1, 6-hexylene glycol two (methyl) acrylate, 1, 9-nonanediol two (methyl) acrylate, 1, 10-decanediol two (methyl) acrylate, two (methyl) acrylic acid glyceride, dihydroxymethyl tristane two (methyl) acrylate, PEG#200 bis-(methyl) acrylate, PEG#400 bis-(methyl) acrylate, the two sense cross-linkable monomers such as PEG#600 bis-(methyl) acrylate, trimethylolpropane tris (methyl) acrylate, pentaerythrite three (methyl) acrylate, isocyanic acid triallyl, 1,3, the trifunctional cross-linkable monomers such as 5-triacryl six hydrogen-1,3,5-triazines (triacrylformal), the multifunctional cross-linkable monomer more than trifunctional such as pentaerythrite four (methyl) acrylate, double trimethylolpropane four (methyl) acrylate, dipentaerythritol six (methyl) acrylate, etc..The usage ratio of cross-linkable monomer be take the total amount of polymerizable monomer and is preferably 0.05～5 quality % as benchmark, more preferably 0.1～3 quality %.

As blowing agent, with can be by heating to gasify or producing the material of gas.As blowing agent, preferred gasifiable compound at the temperature below the softening point of polymer (thermoplastic resin) that forms shell.As such blowing agent, low boiling point organic solvent is preferred, for example can enumerate ethane, ethene, propane, propylene, normal butane, iso-butane, butylene, isobutene, pentane, isopentane, neopentane, 2,2,4-trimethylpentane, n-hexane, isohexane, normal heptane, 2,2,4,6, the hydrocarbon such as 6-five methylheptane (that is, Permethyl 99A), benzinum; CCl ₃f, CCl ₂f ₂, CClF ₃, CClF ₂-CClF ₂deng Chlorofluorocarbons; The tetraalkyl silane such as tetramethylsilane, trimethyl ethylsilane, trimethyl isopropyl silane, trimethyl n-pro-pyl silane; Etc..These blowing agents can use separately respectively or two or more is used in combination.

Wherein, preferred iso-butane, normal butane, pentane, isopentane, n-hexane, isohexane, heptane, 2,2,4-trimethylpentane, Permethyl 99A, benzinum and their mixture of more than two kinds.The blowing agent that can produce gas by heating is that Celogen Az etc. carries out by heating the compound that thermal decomposition produces gas.

The content of the blowing agent of enclosing in heat-expandable microsphere is preferably 5～50 quality %, more preferably 7～40 quality %.The usage ratio of polymerizable monomer and blowing agent preferably regulates according to the mode that is aforementioned proportion at polymerization rear casing polymer and blowing agent.

As polymerization initiator, it in polymerizable monomer, is preferably the oil-soluble polymerization initiator of solubility.As polymerization initiator, for example can enumerate dialkyl, peroxidating diacyl, peroxyester, peroxy dicarbonate and azo-compound.Polymerization initiator is generally comprised within monomer mixture, but in the situation that needs suppress premature polymerization, can in granulating working procedure or after granulating working procedure, by it, part or all add in aqueous dispersion medium, move it in the drop of polymerism mixture.Polymerization initiator be take aqueous dispersion medium and conventionally with the ratio of 0.0001～3 quality %, is used as benchmark.

Suspension polymerisation is carried out conventionally in containing the aqueous dispersion medium of dispersion stabilizer.As dispersion stabilizer, for example can enumerate the inorganic particles such as silica, magnesium hydroxide.In addition, as auxiliary stabilizer, for example can use the condensation product of diethanol amine and aliphatic dicarboxylic acid, polyvinylpyrrolidone, polyethylene glycol oxide, various emulsifying agents etc.Dispersion stabilizer is used with the ratio of 0.1～20 mass parts conventionally with respect to polymerizable monomer 100 mass parts.

The aqueous dispersion medium that contains dispersion stabilizer is conventionally by being engaged in dispersion stabilizer, auxiliary stabilizer in deionized water and modulating.During polymerization, the pH value of water is suitably determined according to the kind of used dispersion stabilizer, auxiliary stabilizer.For example, in the situation that using the silica such as colloidal silica as dispersion stabilizer, under sour environment, carry out polymerization.In order to make aqueous dispersion medium, be acid, add as required acid, the pH value of system is adjusted into below 7, be preferably below pH6, be particularly preferably left and right, pH3～4.At magnesium hydroxide, calcium phosphate etc., in the situation that be dissolved in the dispersion stabilizer in aqueous dispersion medium under sour environment, under alkaline environment, carry out polymerization.

As one of preferred compositions of dispersion stabilizer, there is the combination of colloidal silica and condensation product.As condensation product, be preferably the condensation product of diethanol amine and aliphatic dicarboxylic acid, particularly preferably the condensation product of the condensation product of diethanol amine and adipic acid, diethanol amine and itaconic acid.The acid number of condensation product is preferably more than 60 and is less than 95, and more preferably 65～90.In addition,, if add the inorganic salts such as sodium chloride, sodium sulphate, easily obtain and there is the more heat-expandable microsphere of uniform particle shape.As inorganic salts, conventionally preferably use salt.

The use amount of colloidal silica changes according to its particle diameter, conventionally with respect to polymerizable monomer 100 mass parts, is 0.5～20 mass parts, is preferably in the scope of 1～15 mass parts.Condensation product is used with the ratio of 0.05～2 mass parts conventionally with respect to polymerizable monomer 100 mass parts.The ratio that it is 0～100 mass parts that inorganic salts be take with respect to polymerizable monomer 100 mass parts is used.

As reagent and additive in polymerization, can make to exist and be selected from least one compound in nitrite alkali slaine, stannous chloride, stannic chloride, water dissolvable Vitamin C acids and boric acid in aqueous dispersion medium.If carry out suspension polymerisation under the existence of these compounds, can when polymerization, not occur that polymer particles condenses each other, polymer removes the heat release being produced by polymerization can not be attached on polymeric kettle wall in the situation that effectively, heat-expandable macrosphere is manufactured on Simultaneous Stabilization ground.

In nitrite alkali slaine, natrium nitrosum and potassium nitrite in the easiness obtaining, be preferred in price.As Vitamin C acids, can enumerate the slaine of ascorbic acid, ascorbic acid, the ester of ascorbic acid etc., wherein preferably use the Vitamin C acids of water dissolvable.Water dissolvable Vitamin C acids means that to the dissolubility of the water of 23 ℃ be 1g/100cm ³above material, preferably ascorbic acid and its alkali metal salt.Wherein, preferred L-AA (vitamin C), sodium ascorbate and potassium ascorbate.Reagent and additive in polymerization being generally 0.001～2 mass parts with respect to polymerizable monomer 100 mass parts, the ratio that is preferably 0.01～1 mass parts used.

The order of adding each composition in aqueous dispersion medium is arbitrarily, conventionally adds water and dispersion stabilizer, adds stabilization aid, reagent and additive in polymerization etc. as required, thus the aqueous dispersion medium that modulation contains dispersion stabilizer.On the other hand, can respectively polymerizable monomer and blowing agent be joined in aqueous dispersion medium, integrated formation polymerizable monomer mixture (oily mixture) in aqueous dispersion medium, but conventionally will after polymerizable monomer and blowing agent mixing, add in aqueous dispersion medium more in advance.Polymerization initiator can add in polymerizable monomer and use in advance, but in the situation that needs are avoided premature polymerization, for example, the mixture of polymerizable monomer and blowing agent can be added in aqueous dispersion medium, while stirring, add polymerization initiator, integrated in aqueous dispersion medium.Can make to carry out in the other container of being blended in of polymerism mixture and aqueous dispersion medium, with mixer, the dispersion machine with high shear force, be uniformly mixed, then join in polymeric kettle.

By polymerizable monomer mixture and aqueous dispersion medium are uniformly mixed, thereby in aqueous dispersion medium, form the drop of polymerizable monomer mixture.The average grain diameter of drop is preferably roughly consistent with the average grain diameter of target heat-expandable microsphere.Suspension polymerisation is normally by degassed in reactive tank or with inert gas replacement, then is warmed up to the temperature of 30～100 ℃ and carries out.

After suspension polymerisation, water is removed by for example filtration, centrifugation, sedimentation.Heat-expandable microsphere is dried after filtering, washing.Heat-expandable microsphere is not dried under the lower temperature of gasification degree at blowing agent.

The average grain diameter of heat-expandable microsphere of the present invention is generally 0.5～150 μ m, is preferably 1～130 μ m, and more preferably 3～100 μ m, are particularly preferably in the scope of 5～50 μ m.The content of the blowing agent of heat-expandable microsphere of the present invention is generally 5～50 quality %, is preferably 7～40 quality %.The blowing temperature of heat-expandable microsphere changes according to the difference of the kind of the thermoplastic resin (polymer) of formation shell, thickness etc.

Manufacture method of the present invention be comprise following operation 1 and operation 2 in shell surface attachment, have the manufacture method of the hollow microsphere of solid material.

With reference to Fig. 2, the summary of manufacture method of the present invention is described.As shown in Fig. 2 (a), in container 21, be added in liquid dispersion medium 22, disperseed heat-expandable microsphere 1 and solid material 23 and slurry.For heat-expandable microsphere 1 and solid material 23 are disperseed equably, preferably stir.By be blown into the heating means such as heating water steam in this slurry, make heat-expandable microsphere foamable,, as shown in Fig. 2 (b), generate foaming body (hollow microsphere) 101, and have a plurality of solid materials 23 in its surface attachment.

The solid material using in operation 1 is under normal temperature (25 ± 15 ℃), for solid, average grain diameter or average major diameter, to be less than the micro-solid material of the average grain diameter of heat-expandable microsphere.The shape of solid material is granular, spherical, cubic, spindle shape, bar-shaped, tabular, needle-like, fibrous etc., has no particular limits.The material of solid material can be both that inorganic matter can be also organic matter.

As solid inorganic material, for example can enumerate the natural goodses such as silica, lime stone, quartz, apatite, magnetic iron ore, zeolite, clay (montmorillonite, hectorite, saponite, vermiculite, talcum, mica, mica (mica) etc.); The carbonic acid metal salts such as calcium carbonate; The metal sulfates such as barium sulfate, aluminum sulfate, cobaltous sulfate, copper sulphate, nickelous sulfate; The metal oxides such as titanium oxide, zinc oxide, aluminium oxide, tin oxide, vanadium oxide, indium oxide, chromium oxide, tungsten oxide, iron oxide; The metal hydroxides such as aluminium hydroxide, magnesium hydroxide; The metal sulfide such as copper sulfide, vulcanized lead; The metal borate such as aluminium borate, Firebrake ZB; The metal nitrides such as aluminium nitride, chromium nitride, cobalt nitride; The glass such as glass flake, bead; The potteries such as ceramic bead; The particulate of metal or alloy; The carbide such as carbon black, CNT, graphite, active carbon, fullerene; The powder bodies such as crystal pearl, mica, ネ Off エリ Application シ Na イト, hydrotalcite, synthetic silicic acid, silica flour, Cab-O-sil, diatomite, ground pumice, other inorganic pigment.

As the solid inorganic material of colloidal, for example can enumerate colloidal silica, colloidal calcium carbonate, magnesium hydroxide colloid, calcium phosphate colloid etc.As needle-like or fibrous solid inorganic material, can enumerate glass fibre, carbon fiber, alumina fibre, potassium titanate crystal whisker, aluminium borate whisker, wollastonite (ウオラス Na イト) etc.

As organic solid material, for example can enumerate the particulate of the organic resins such as polystyrene bead, polymethyl methacrylate pearl, polytetrafluoroethylene (PTFE) pearl, cotton fiber, Fypro etc.The particulate of organic resin comprise imported cross-linked structure organic resin particulate, imported the organic resin particulate of functional group or polar group etc.

These solid materials can be distinguished use separately, or two or more is used in combination.Solid material can be to have implemented the surface-treated materials such as hydrophobization processing.By selection, be attached to the kind of solid material of the case surface of hollow microsphere, can control proportion or give the functions such as thermal insulation, sliding, sound-proofing, electric conductivity, magnetic, piezoelectricity, bactericidal properties, ultraviolet-absorbing.

Average grain diameter or average major diameter inorganic and/or organic solid material are preferably fully less than the average grain diameter of heat-expandable microsphere, are generally below 10 μ m, are preferably below 3 μ m, more preferably, below 1 μ m, are particularly preferably below 0.1 μ m.The lower limit of this average grain diameter or average major diameter is 0.001 μ m left and right from the viewpoint of effect and operability.The average grain diameter of solid material is by having used the observation counting method of electron microscope or light microscope to measure average diameter or the average major diameter of the primary particle obtaining.

As solid material, using average grain diameter is below 3 μ m, is preferably below 1 μ m, and more preferably below 0.1 μ m, and proportion (true specific gravity) is 1.5～6.0g/cm ³, be preferably 2.0～6.0g/cm ³, 2.5～5.8g/cm more preferably ³scope at least one inorganic matter, thereby can improve the proportion of hollow microsphere.As such inorganic matter, for example can enumerate calcium carbonate (for example, proportion=about 2.70g/cm ³powdered whiting, proportion=about 2.60g/cm ³lightweight and colloidal calcium carbonate), crystallinity silica (proportion=2.6g/cm ³), aluminium oxide (proportion=3.98g/cm ³), kaolin (clay) (proportion=2.5～2.6g/cm ³), titanium oxide (for example, proportion=3.9g/cm ³detitanium-ore-type or proportion=4.2g/cm ³rutile-type), barium sulfate (proportion=4.50g/cm ³), zinc oxide (proportion=5.70g/cm ³common zinc oxide or proportion=5.78g/cm ³four-needle-like zinc oxide) etc.

The content of solid material (adhesion amount) can suitably be determined according to the kind of required function and solid material, the total amount of the hollow microsphere that is attached with solid material of take is benchmark, be generally 1～99.9 quality %, be preferably 10～99.5 quality %, more preferably 15～99.3 quality %, are particularly preferably in the scope of 20～99.0 quality %.For example, yet the adhesion amount of the dispersion stabilizer (, the inorganic particles such as silica, magnesium hydroxide) using in order to control the particle diameter of heat-expandable microsphere is not included.

Solid material is of poor quality calculating the between generally can each hollow microsphere based on obtaining under the existence of solid material and not to the adhesion amount of the case surface of hollow microsphere.In the situation that solid material is inorganic matter, can measure again the method for the amount of the ash content after burning by making to be attached to by solid material the hollow microsphere burning that case surface obtains, calculate the adhesion amount of solid material.

If the content of solid material is very few, be difficult to preventing bringing into play fully various functions when heat-expandable microsphere from condensing each other.If the content of solid material is too much, heat-expandable microsphere is difficult to foaming.

In above-mentioned operation 1, the solid material that makes heat-expandable microsphere and average grain diameter or average major diameter be less than the average grain diameter of this heat-expandable microsphere is dispersed in liquid dispersion medium, thus modulation slurry.

As liquid dispersion medium, be preferably formed the medium that thermoplastic resin does not dissolve or solubility is little of the shell of heat-expandable microsphere.The thermoplastic resin that liquid dispersion medium does not preferably make to form the shell of heat-expandable microsphere decomposes or the low medium of degree of decomposition.

As the concrete example of liquid dispersion medium, can enumerate water; Isopropyl alcohol, ethylene glycol, glycerine, phthalic acid ester, silicone oil, paraffin wet goods organic solvent; The mixed solvents such as water/ethylene glycol mixture, water/glycerine mixed liquor; Etc..Wherein, preferred water and the aqueous dispersion mediums such as mixed solvent that contain water, particularly preferably water.In liquid dispersion medium, can add surfactant, dispersion stabilizer etc. as required.

The concentration of the heat-expandable microsphere in liquid dispersion medium is generally 0.1～10 quality %, is preferably 0.1～8 quality %, and more preferably 0.2～7 quality %, is particularly preferably in the scope of 0.3～5 quality %.If its excessive concentration, easily there is each other the addition that heat merges, maybe must reduce solid material in foaming body when the foamable of heat-expandable microsphere.If its concentration is too low, production efficiency reduces.

At heat-expandable microsphere, be in the situation that the polymerizable monomer mixture that contains polymerizable monomer and blowing agent is carried out to suspension polymerisation and forms in aqueous dispersion medium, by before suspension polymerisation, in suspension polymerisation process or after suspension polymerisation, in aqueous dispersion medium, add solid material, thus can modulate that heat-expandable microsphere and solid material are dispersed in aqueous dispersion medium and slurry.In this case, can be before the front and back of suspension polymerisation, suspension polymerisation and suspension polymerisation process medium, add several times solid material.In the situation that solid material is the such dispersion stabilizer of colloidal silica, conventionally in suspension polymerisation process, add after suspension polymerisation.In order to adjust the concentration of the heat-expandable microsphere in slurry, can add the liquid dispersion mediums such as water or by a part for aqueous dispersion medium by filtering or tilting to remove.

At heat-expandable microsphere, be by the situation that the polymerizable monomer mixture that contains polymerizable monomer and blowing agent is carried out to suspension polymerisation in aqueous dispersion medium and form, heat-expandable microsphere from reclaiming aqueous dispersion medium can be dispersed in the decentralized medium of liquid together with solid material, thus modulation slurry.

In above-mentioned operation 2, in slurry, heat heat-expandable microsphere, make its shell softening, and the gasification by blowing agent or the gas that produces from blowing agent and thermal expansion, thus, be formed on the hollow microsphere that the case surface of having softened is attached with solid material.

Owing to conventionally there is difference in specific gravity between heat-expandable microsphere and solid material, therefore preferably in possessing the container of agitating device (tank, polymeric kettle etc.), add slurry, stir, heat-expandable microsphere and solid material are evenly dispersed in slurry.The foamable of heat-expandable microsphere also preferably carries out while stirring slurry.

As foamable method, there are the method for heating slurry, the method that is blown into heating water steam in slurry, dielectric heating method etc.The liquid evaporating under lower temperature using aqueous dispersion medium etc. in the situation that, as liquid dispersion medium, can heat pressurization.Wherein, being blown into the method for heating water steam in slurry, owing to making heat-expandable microsphere foamable in the short time at the utmost point, is therefore particularly preferred.The temperature of heating water steam depends on the blowing temperature of heat-expandable microsphere, is generally 100～200 ℃, is preferably 110～190 ℃, more preferably in the scope of 120～180 ℃.Pressure when heating water steam is blown into is generally 0.1～1.56MPa, is preferably 0.14～1.26MPa, more preferably in the scope of 0.2～1.0MPa.

After foamable in slurry, filter slurry, the method for washing foaming body particle, reclaims the hollow microsphere that solid material is attached to case surface securely.Hollow microsphere of the present invention, the shell being formed by thermoplastic resin during due to foamable is softening, and the case surface of the state that this has softened is adhered to solid material, therefore by common washing step, can not make the solid material adhering to come off.

The average grain diameter of hollow microsphere of the present invention is preferably 2～200 μ m, and more preferably 5～100 μ m, are particularly preferably in the scope of 10～60 μ m.If the average grain diameter of hollow microsphere is too small,, in the situation that using this hollow microsphere as Porous forming agent, the formation of porous structure is easily insufficient.On the other hand, if the average grain diameter of this hollow microsphere is excessive, when the raw material with forming the Porous formed bodys such as porous ceramic formed body carries out when mixing and/or in the mixture moulding by mixing acquisition, this hollow microsphere easily breaks, consequently, the formation of porous structure may be insufficient.

Hollow microsphere of the present invention, because its case surface is attached with solid material, therefore can prevent from merging each other, and, in the time of can being suppressed at its operation, disperse in air.By adjustment, be attached to kind and the amount of the solid material of case surface, can give hollow microsphere with various functions.

Hollow microsphere of the present invention, by making hyperbaric solid material be attached to its case surface, can improve the proportion (apparent specific gravity) of particle integral body, and thus, the inorganic material high with proportion etc. easily evenly mixed.Hyperbaric hollow microsphere is suitable as the Porous forming agent of using in the manufacturing process of porous ceramic formed body for example.Used the porous ceramic formed body of Porous forming agent to manufacture by disclosed manufacture method in for example TOHKEMY 2007-39333 communique (patent documentation 1).

Particularly, in the manufacture method of porous ceramic formed body that comprises following operation a～c, as this Porous forming agent, the case surface that use obtains by above-mentioned manufacture method is attached with the hollow microsphere of solid material, described operation is: operation a, mixes to come modulating mixture by ceramic raw material with Porous forming agent; Operation b, is shaped to this mixture the formed body of regulation shape; And operation c, this formed body is burnt till.

As ceramic raw material, can enumerate mixture, carborundum, metallic silicon of the potteries such as talcum, kaolin, aluminium oxide, aluminium hydroxide, silica etc.Case surface is attached with the usage ratio of the hollow microsphere of solid material and can suitably determines according to required porous structure.Firing temperature is 1400～2000 ℃ of left and right.

Generally speaking, being called as ceramic material group is extremely widely, and its characteristic is also various.The kind of pottery comprises pottery chinaware, glass, cement, gypsum, enamel, fine ceramics (new system pottery) etc.

Hollow microsphere of the present invention, for example, the Porous forming agent that also can be used as lightweight aerated concrete (ALC) is used.The ALC that contains this Porous forming agent, inside comprises separated foam, unusual light weight, but can the higher such excellent specific property of Developed fiber strength.ALC is light weight but also intensity is higher, fire resistance, thermal insulation, application property are also excellent not only, therefore as the construction material on the wall of building, floor etc., is widely used.

In the manufacture of ALC, generally use the calcareous raw materials such as the silicic acid raw materials such as silica and cement, lime as main material, use gypsum and operation repetition raw material etc. as auxiliary material.In the micropowder of these raw materials, add water and Porous forming agent to make slurry, then this slurry is added to and in mould, make its semi-solid preparation.Next, by adopting autoclave to carry out high-temperature high-pressure steam maintenance semi-solid preparation thing, thereby can obtain ALC.

Manufacture in this wise ALC as the operation of porous ceramic formed body, comprise following operation a～c: operation a, ceramic raw material is mixed to come modulating mixture with Porous forming agent; Operation b, is shaped to this mixture the formed body of regulation shape; And operation c, this formed body is carried out to maintenance.With cement, gypsum etc., as ceramic raw material, manufacturing in the technique of porous ceramic formed body, sometimes carrying out maintenance and replace burning till.In the present invention, as the Porous forming agent of ALC etc., use hollow microsphere of the present invention.

Embodiment

More specifically the present invention will be described below to enumerate embodiment and comparative example, but the present invention is not limited only to these embodiment.In the present invention, the assay method of physical property and characteristic is as follows.

(1) expansion ratio

Heat-expandable microsphere 0.7g is put into gill formula baking oven, under the blowing temperature of regulation, heat and within 2 minutes, make its foaming (thermal expansion).The hollow microsphere of gained is put into graduated cylinder, measure its volume.Volume by the volume of hollow microsphere divided by the heat-expandable microsphere not foaming, calculates expansion ratio.Now, blowing temperature is heated up with every 5 ℃ since 70 ℃, make it in foaming at each temperature.To under this condition, obtain expansion ratio at the temperature of maximum expansion ratio as maximum expansion ratio.

(2) average grain diameter

Use Nikkiso Company Limited's system " マイ Network ロトラ Star Network MT3300EX " (registration mark), measured the average grain diameter (median diameter) of heat-expandable macrosphere and foaming body particle.

(3) proportion

The proportion of heat-expandable microsphere and hollow microsphere means the proportion of particle integral body, according to the use of stipulating in JIS Z8807 the determination method of specific gravity bottle measure.

(4) content of solid material

The quality of the ash content after heat-expandable microsphere and the content of solid material that is attached to the case surface of hollow microsphere burn by mensuration is calculated.Its concrete steps are as follows.

The quantitative > of < blowing agent

1 amount and the ratio of having carried out round the clock the remaining blowing agent that dry hollow microsphere (drying sample) comprises of preserving in drier after air-dry adopts following steps to measure.

A) by the about 0.2g of drying sample being joined in aluminum cup (diameter 6cm, height 3cm).Now, weigh the quality put into the cup before sample, having put into sample after, weigh comprise cup quality, calculate the poor of them, thus the exact mass of mensuration drying sample.

B) then, to the upper cover of aluminum on bowl cover, in order to make blowing agent gasification at 200 ℃ heat treated 10 minutes, weigh afterwards through the sample of heat treated (below the sample after heat treated being called to " sample of having removed blowing agent ").

C) here, obtain of poor quality before and after heat treated, the amount of the blowing agent that this volatilizes with particle from drying sample is consistent.Use this numerical computations to go out remaining blowing agent with respect to the ratio (f: quality %) of drying sample integral body.Quantitative experiment respectively carries out 2 times.

The quantitative > of < ash content

D) will adopt the sample 1.5～1.7g that removed blowing agent made with above-mentioned " blowing agent quantitatively " same steps to weigh on medical packing paper, using this weighing value as Wdf (g).

E) accurately weigh the empty quality of magnetic crucible, using this weighing value as Wa (g).

F) the each a small amount of gradation of the sample of having removed blowing agent after weighing is put into magnetic crucible, adopt electric heater to repeat the such operation of pre-carbonization, after all sample carbonization finishes, adopt the electric furnace of 930 ℃ to make its ashing more than 3 hours.

G), after cooling, weigh and comprise calcination in the quality of interior magnetic crucible, using this weighing value as Wb (g).

H) ash amount Ws (g) obtains according to following formula.

Ws(g)＝Wb(g)-Wa(g)

I) by the following calculating formula of these numerical value substitutions, calculate ash amount with respect to the value of drying sample whole (quality %).Quantitative experiment respectively carries out 2 times, calculates mean value.

[several 1]

[modulation example 1]

(1) modulation of aqueous dispersion medium

In deionized water 770g, add the colloidal silica 22g of solid constituent 40 quality % to make its dispersion.Then, in dispersion liquid, add diethanol amine-adipic acid condensation product 0.8g and natrium nitrosum 0.13g to make its dissolving.Then, in dispersion liquid, add hydrochloric acid, thereby modulate the aqueous dispersion medium of pH3.5.

(2) modulation of polymerizable monomer mixture

By vinylidene chloride 123g, acrylonitrile 86g, methyl methacrylate 11g, diethylene glycol (DEG) two (methacrylate) 0.33g, 2,2 '-azo is two-and methyl pentane nitrile 1.1g and normal butane 35g mix, thereby modulate polymerizable monomer mixture.The quality % of each polymerizable monomer in polymerizable monomer mixture is, vinylidene chloride/acrylonitrile/methyl methacrylate=56/39/5.

(3) formation of drop

Adopt homogenizer that the polymerizable monomer mixture of modulation in the aqueous dispersion medium of modulation in above-mentioned (1) and above-mentioned (2) is uniformly mixed, thereby in aqueous dispersion medium, formed the fine droplet of polymerizable monomer mixture.

(4) suspension polymerisation

The aqueous dispersion medium that has disperseed the drop of polymerizable monomer mixture is joined in the polymeric kettle with mixer of 1.5 liters of capacity.By this polymeric kettle is put into tepidarium, at 50 ℃, keep 22 hours, make polymerizable monomer mixture carry out polymerisation.By this polymerisation, formed the heat-expandable microsphere with the microcapsule structure of having enclosed the normal butane of blowing agent and obtain in the shell being formed by vinylidene chloride-acrylonitrile methyl meth acrylat copolymer.After polymerisation, the reactant mixture in polymeric kettle is filtered to washing.Then, will wash and filter and repeat 2 times, then be dried, reclaim heat-expandable microsphere.

(5) heat-expandable microsphere

The average grain diameter of the heat-expandable microsphere obtaining is like this 14 μ m, and the maximum expansion ratio at 130 ℃ of blowing temperatures is 50 times, and proportion is 0.02g/cm ³.This heat-expandable microsphere is usingd the content of 3.3 quality % and is contained the colloidal silica using as dispersion stabilizer.

[comparative example 1]

In the heat-expandable microsphere obtaining in modulation example 1, add deionized water, thereby modulate the water paste 500g of the concentration 1 quality % of this heat-expandable microsphere.This water paste is joined in the polymeric kettle with mixer of 1.5 liters of capacity.While stirring water paste, with pressure 0.48MPa, be blown into wherein the steam of 150 ℃ of temperature, heat-expandable microsphere heating is made to its foaming.The foaming body particle (hollow microsphere) that foaming by heat-expandable microsphere forms all floats to top, the particle that wherein has heat to merge.

[comparative example 2]

In the heat-expandable microsphere obtaining in modulation example 1, add deionized water, thereby modulate the water paste 500g of the concentration 1 quality % of this heat-expandable microsphere.This water paste is joined in the polymeric kettle with mixer of 1.5 liters of capacity.While stirring water paste the lower stirring of room temperature (23 ℃) 1 hour, the colloidal silica that result owing to dissociating makes water paste gonorrhoea.

This water paste is filtered to reclaim heat-expandable microsphere, results verification the content of colloidal silica from 3.3 initial quality %, be reduced to 2.4 quality %.This heat-expandable microsphere is heated to 130 ℃ and makes its foaming, result has been observed between foaming body particle and has strongly been merged.Maximum expansion ratio at 130 ℃ of the blowing temperatures of this heat-expandable microsphere is 50 times.

[embodiment 1]

In the heat-expandable microsphere obtaining, add deionized water in modulation example 1, thereby modulate the water paste 500g of the concentration 1 quality % of this heat-expandable microsphere.In this water paste, add colloidal calcium carbonate (average grain diameter 50nm) 40g, then join in the polymeric kettle with mixer of 1.5 liters of capacity.While stirring this water paste, with pressure 0.48Mpa, be blown into wherein the steam that is heated to 150 ℃ of temperature, make heat-expandable microsphere foamable.In water paste after foaming is processed, foaming body particle (hollow microsphere) disperses, and can not form agglomerate.

Foaming body particle in water paste is filtered to washing.Then, will wash and filter and repeat 2 times, then be dried, reclaim foaming body particle (hollow microsphere).The average grain diameter of this foaming body particle is 50 μ m, and proportion is 0.095g/cm ³.The total content of the inorganic matter that this foaming body particle comprises is 80 quality %.The hollow microsphere obtaining has like this suppressed the dustability dispersing in air significantly, and, excellent with the Combination of the high inorganic matter of proportion.

[embodiment 2]

Beyond use colloidal silica (solid constituent 40 quality %, average grain diameter 12nm) 100g replacement colloidal calcium carbonate 40g, make similarly to Example 1 foaming body particle (hollow microsphere).The average grain diameter of this foaming body particle is 53 μ m, and proportion is 0.10g/cm ³.The total content of the inorganic matter that this foaming body particle comprises is 85 quality %.The hollow microsphere obtaining has like this suppressed the dustability dispersing in air significantly, and, excellent with the Combination of the high inorganic matter of proportion.

Industry utilizability

The hollow microsphere that case surface of the present invention is attached with solid material can make the lightweights such as plastics, coating, various materials, porous materialization, gives various functions and in technical field, using widely.High specific gravity the hollow microsphere Porous forming agent that also can be used as porous ceramic formed body use.

Claims

1. in the case surface being formed by thermoplastic resin, be attached with a manufacture method for the hollow microsphere of solid material, described manufacture method is characterised in that, comprises following operation 1 and operation 2:

(1) operation 1, make following heat-expandable microsphere, the solid material that is less than the average grain diameter of this heat-expandable microsphere with average grain diameter or average major diameter is dispersed in liquid dispersion medium, thereby modulation slurry, described heat-expandable microsphere has in the shell being formed by thermoplastic resin to be enclosed and has the gasifiable microcapsule structure that maybe can produce the blowing agent of gas, and can carry out thermal expansion by heating, form hollow microsphere, in described operation 1, the concentration of the heat-expandable microsphere in this liquid dispersion medium is 0.1～10 quality %, and, this liquid dispersion medium is water or the mixed solvent that contains water, and

(2) operation 2, in this slurry, heat this heat-expandable microsphere, make its shell softening, and the gasification by this blowing agent or the gas being produced by this blowing agent and thermal expansion, thus, be formed on the hollow microsphere that the case surface of having softened is attached with this solid material, and heating means are method, the method that is blown into heating water steam in slurry or the dielectric heating method of heating slurry.

2. manufacture method according to claim 1, this solid material be selected from there is granular, spherical, cubic, spindle shape, bar-shaped, tabular, needle-like or the inorganic matter of fibrous shape and at least one solid material in organic matter.

3. manufacture method according to claim 1, this solid material is that average grain diameter is that the following and proportion of 3 μ m is 1.5～6.0g/cm ³scope at least one inorganic matter.

4. manufacture method according to claim 1, this solid material is at least one inorganic matter being selected from calcium carbonate, crystallinity silica, aluminium oxide, kaolin, titanium oxide, barium sulfate and zinc oxide.

5. manufacture method according to claim 1, this heat-expandable microsphere has the average grain diameter in the scope of 0.5～150 μ m.

6. in the case surface being formed by thermoplastic resin, be attached with a manufacture method for the hollow microsphere of solid material, described manufacture method is characterised in that, comprises following operation 1a and operation 2a:

(1a) operation 1a, in containing the aqueous dispersion medium of dispersion stabilizer, the polymerizable monomer mixture that at least contains polymerizable monomer and blowing agent is carried out to suspension polymerisation, manufacture heat-expandable microsphere, described heat-expandable microsphere has in the shell being formed by thermoplastic resin to be enclosed and has the gasifiable microcapsule structure that maybe can produce the blowing agent of gas, and can carry out thermal expansion by heating, form hollow microsphere, and, by before suspension polymerisation, in suspension polymerisation process or after suspension polymerisation, in this aqueous dispersion medium, add the solid material that average grain diameter or average major diameter are less than the average grain diameter of this heat-expandable microsphere, thereby be modulated at the slurry that is dispersed with heat-expandable microsphere and solid material in this aqueous dispersion medium, the concentration of the heat-expandable microsphere in this aqueous dispersion medium is 0.1～10 quality %, and

(2a) operation 2a, in this slurry, heat this heat-expandable microsphere, make its shell softening, and the gasification by this blowing agent or the gas being produced by this blowing agent and thermal expansion, thus, be formed on the hollow microsphere that the case surface of having softened is attached with this solid material, and heating means are method, the method that is blown into heating water steam in slurry or the dielectric heating method of heating slurry.

7. manufacture method according to claim 6, this solid material be selected from there is granular, spherical, cubic, spindle shape, bar-shaped, tabular, needle-like or the inorganic matter of fibrous shape and at least one solid material in organic matter.

8. manufacture method according to claim 6, this solid material is that average grain diameter is that the following and proportion of 3 μ m is 1.5～6.0g/cm ³scope at least one inorganic matter.

9. manufacture method according to claim 6, this solid material is at least one inorganic matter being selected from calcium carbonate, crystallinity silica, aluminium oxide, kaolin, titanium oxide, barium sulfate and zinc oxide.

10. manufacture method according to claim 6, this heat-expandable microsphere has the average grain diameter in the scope of 0.5～150 μ m.

11. manufacture methods according to claim 1 in described operation 2, are blown into heating water steam and heat this heat-expandable microsphere in this slurry, make its thermal expansion.

12. manufacture methods according to claim 6 in described operation 2a, are blown into heating water steam and heat this heat-expandable microsphere in this slurry, make its thermal expansion.

13. manufacture methods according to claim 1, in described operation 2, form case surface and are attached with and take the hollow microsphere that the total amount of this hollow microsphere is the solid material of benchmark in the scope of 1～99.9 quality %.

14. manufacture methods according to claim 6, in described operation 2a, form case surface and are attached with and take the hollow microsphere that the total amount of this hollow microsphere is the solid material of benchmark in the scope of 1～99.9 quality %.

15. according to the manufacture method described in claim 1 or 6, and this hollow microsphere has the average grain diameter in the scope of 2～200 μ m.

The manufacture method of 16. 1 kinds of porous ceramic formed bodys, is characterized in that, comprises following operation a～c:

Operation b, is shaped to this mixture the formed body of regulation shape;

Operation c, carries out maintenance or burns till this formed body,

In described manufacture method, as this Porous forming agent, use obtains by the manufacture method described in claim 1 or 6, case surface is attached with the hollow microsphere of solid material.