JP6182004B2 - Master Badge - Google Patents

Description

  The present invention relates to a master batch and its use.

Conventionally, when manufacturing various foams such as films, sheets, injection-molded products, etc., molding is performed by mixing foam components such as thermally expandable microspheres and various chemical foaming agents into resin pellets. The foaming component used in is easy to scatter, and even when mixed with resin pellets, while being supplied to various molding machines, the resin pellets and foaming component are easily separated, so the dispersibility of the foaming component in the mixture is poor, In the foamed molded product, there arises a problem that foaming unevenness, non-uniform strength and the like are likely to occur.
Therefore, a method for preparing a master batch in which resin pellets and foamed components are kneaded in advance at a temperature not lower than the softening temperature of the resin pellets and not higher than the foaming temperature of the foamed components, and containing thermally expandable microspheres is performed. It has been broken.

For example, Patent Literature 1 proposes a masterbatch containing thermally expandable microspheres using low density polyethylene as a base component. In this example, a master batch is molded by adding a small amount of 5 parts by weight to 100 parts by weight of low density polyethylene to obtain a foamed molded article.
However, in Patent Document 1, the dispersibility of the foaming component in the foamed molded product is improved, but the hardness of the masterbatch is high, so that the masterbatch bites into the cylinder at the raw material supply port when supplied to the extruder. Dust may become unstable. Also, due to the influence, the master batch is not stably supplied into the cylinder, resulting in uneven foaming in the resulting foamed molded product, or the amount of foam sheet discharged from the molding machine becoming unstable. There was a problem.

International Publication No. 2010/038615 Pamphlet

  An object of the present invention is to provide a master batch capable of producing a foam molded article excellent in dispersibility of thermally expandable microspheres and having a stable expansion ratio, and a foam molded article formed using the master batch. Is to provide.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be achieved when the hardness of the organic base component constituting the master batch is within a specific range, and have reached the present invention.
That is, the masterbatch according to the present invention has a thermally expandable microsphere composed of an outer shell made of a thermoplastic resin and a foaming agent contained in the outer shell and vaporized by heating, and has an A hardness of 15 to 54. including a thermoplastic elastomer.

It is preferable that the master batch of the present invention satisfies at least one of the constituent requirements (A) to ( C ) shown below.
(A) The weight ratio of the said thermally expansible microsphere is 20 to 70 weight% of the total amount of the said thermally expansible microsphere and a thermoplastic elastomer .
(B) The thermoplastic resin is obtained by polymerizing a polymerizable component containing a nitrile monomer. The polymerizable component may further include a carboxyl group-containing monomer. When the polymerizable component further contains a carboxyl group-containing monomer, the thermally expandable microspheres may be surface-treated with an organic compound containing a metal belonging to Groups 3-12 of the periodic table.
(C) The expansion start temperature of the thermally expandable microsphere is 100 ° C. or higher .
The foamed molded product of the present invention is formed by molding a composition containing the master batch and the matrix component.

The master batch of the present invention is excellent in dispersibility of thermally expandable microspheres, and when this master batch is used, it is possible to produce a stable foam molded product with no variation in the expansion ratio.
Since the foamed molded article of the present invention is molded using a master batch excellent in dispersibility of thermally expandable microspheres, there is no variation in foaming ratio and is stable.

  The masterbatch of the present invention is a composition comprising thermally expandable microspheres and an organic base component. Hereinafter, each component will be described in detail.

[Thermal expandable microspheres]
The heat-expandable microsphere is a heat-expandable microsphere composed of an outer shell made of a thermoplastic resin and a foaming agent encapsulated in the shell and vaporized by heating.
The average particle size of the thermally expandable microsphere is not particularly limited, but is preferably 1 to 100 μm, more preferably 2 to 80 μm, still more preferably 3 to 60 μm, and particularly preferably 5 to 50 μm. When the average particle size is smaller than 1 μm, the expansion performance may be lowered. When the average particle diameter is larger than 100 μm, the bubble diameter in the foamed molded product becomes large and the strength may be lowered.

  The coefficient of variation CV of the particle size distribution of the heat-expandable microspheres is not particularly limited, but is preferably 35% or less, more preferably 30% or less, and particularly preferably 25% or less. The variation coefficient CV is calculated by the following calculation formulas (1) and (2).

(Wherein, s is the standard deviation of the particle size, <x> is an average particle size, x _i is the i-th particle diameter, n is the number of particles.)
The expansion start temperature (Ts) of the thermally expandable microsphere is not particularly limited as long as it is higher than the softening temperature of the organic base material component, but is preferably 100 ° C. or higher, more preferably 120 ° C. or higher, more preferably 140 ° C. or higher, particularly Preferably it is 170 degreeC or more, Most preferably, it is 190 degreeC or more. On the other hand, the upper limit of the expansion start temperature is preferably 300 ° C. When the expansion start temperature is less than 100 ° C., the heat resistance is low and sufficient expansion performance may not be obtained. When the expansion start temperature exceeds 300 ° C., the heat resistance is too high and sufficient expansion performance may not be obtained.

In the masterbatch of the present invention, when this is produced, if it is not performed at a temperature lower than the expansion start temperature, the thermally expandable microspheres will expand. Therefore, it is desirable that the thermally expandable microspheres used have a high expansion start temperature. Normally, when the master batch is manufactured at a temperature lower by 30 ° C. or more than the expansion start temperature so that the thermally expandable microspheres do not expand. Good. On the other hand, when forming a foamed molded product, which will be described in detail below, using a masterbatch, it is often performed at a temperature around the maximum expansion temperature of the thermally expandable microspheres. The difference from the molding temperature is very large. For this reason, the matrix component used in the foamed molded product is often different in kind from the organic base material component used in the production of the masterbatch. Usually, the softening temperature of the organic base material component used at the time of manufacturing the master batch is lower than that of the matrix component used for manufacturing the foamed molded product. When it is necessary to use a large amount of master batch at the time of molding in order to obtain sufficient weight reduction, the heat resistance and strength of the foamed molded product may be reduced. The matrix component used in the foamed molded product may be the same type as the organic base material component used in the production of the masterbatch.
The maximum expansion temperature (Tmax) of the thermally expandable microsphere is not particularly limited, but is preferably 140 ° C. or higher, more preferably 150 ° C. or higher, further preferably 180 ° C. or higher, particularly preferably 200 ° C. or higher, and most preferably 230. It is above ℃. On the other hand, the upper limit of the maximum expansion temperature is preferably 350 ° C. When the maximum expansion temperature is less than 140 ° C., the heat resistance is low and sufficient expansion performance may not be obtained. When the expansion start temperature is higher than 350 ° C., the heat resistance is too high and sufficient expansion performance may not be obtained.

The foaming agent constituting the thermally expandable microsphere is not particularly limited as long as it is a substance that is vaporized by heating. Examples of the blowing agent include propane, (iso) butane, (iso) pentane, (iso) hexane, (iso) heptane, (iso) octane, (iso) nonane, (iso) decane, (iso) undecane, ( Hydrocarbons having 3 to 13 carbon atoms such as iso) dodecane and (iso) tridecane; hydrocarbons having 13 to 20 carbon atoms such as (iso) hexadecane and (iso) eicosane; pseudocumene, petroleum ether, initial boiling point 150 Hydrocarbons such as petroleum fractions such as normal paraffin and isoparaffin having a distillation range of ˜260 ° C. and / or a distillation range of 70 to 360 ° C .; their halides; fluorine-containing compounds such as hydrofluoroethers; tetraalkylsilanes; The compound etc. which decompose | disassemble and produce | generate a gas can be mentioned. These foaming agents may be used alone or in combination of two or more. The foaming agent may be linear, branched or alicyclic, and is preferably aliphatic.
A foaming agent is a substance that is vaporized by heating, but if a substance having a boiling point below the softening point of a thermoplastic resin is included as a foaming agent, a vapor pressure sufficient for expansion at the expansion temperature of the thermally expandable microspheres is obtained. It is preferable because it can be generated and a high expansion ratio can be imparted. In this case, a substance having a boiling point not higher than the softening point of the thermoplastic resin and a substance having a boiling point higher than the softening point of the thermoplastic resin may be included as a foaming agent.

In addition, when encapsulating a substance having a boiling point above the softening point of the thermoplastic resin as the foaming agent, the ratio of the substance having a boiling point above the softening point of the thermoplastic resin to the foaming agent is not particularly limited, but preferably Is 95% by weight or less, more preferably 80% by weight or less, further preferably 70% by weight or less, particularly preferably 65% by weight, particularly more preferably 50% by weight or less, and most preferably less than 30% by weight. When the ratio of the substance having a boiling point exceeding the softening point of the thermoplastic resin exceeds 95% by weight, the maximum expansion temperature is increased, but the expansion ratio is decreased, and the heat insulating property may be decreased, but it exceeds 95% by weight. It may be.
Next, the thermoplastic resin is composed of a copolymer obtained by forming a shell of thermally expandable microspheres and polymerizing a polymerizable component.

The thermoplastic resin must contain a polymerizable component including a monomer component containing a nitrile monomer as an essential component (that is, a polymerizable component including a nitrile monomer) or a carboxyl group-containing monomer. It is preferable that it is comprised from the copolymer obtained by superposing | polymerizing the polymerizable component containing the monomer component contained as (namely, polymerizable component containing a carboxyl group-containing monomer).
The polymerizable component is a component that becomes a copolymer that is a thermoplastic resin that forms an outer shell by polymerization. The polymerizable component is a component which essentially includes a monomer component and may contain a crosslinking agent. The polymerizable component preferably contains a nitrile monomer as a monomer component or a carboxyl group-containing monomer as an essential component.

The monomer component generally includes a component called a (radical) polymerizable monomer having one polymerizable double bond. The monomer component preferably has a nitrile monomer or a carboxyl group-containing monomer as an essential component.
The nitrile monomer is not particularly limited as long as it has one or more nitrile groups per molecule, and examples thereof include acrylonitrile, methacrylonitrile, and fumaronitrile. The inclusion of a nitrile monomer is preferable because the gas barrier property of the thermoplastic resin constituting the outer shell is improved.

The weight ratio of the nitrile monomer is not particularly limited, but is preferably 5 to 100% by weight, more preferably 30 to 95% by weight, and particularly preferably 40 to 90% by weight with respect to the monomer component. It is. When the weight ratio of the nitrile monomer is less than 5% by weight, the gas barrier property is low and sufficient expansion performance may not be obtained. When the nitrile monomer is essentially acrylonitrile and methacrylonitrile, it is preferable because gas barrier properties are high and expansion performance is improved.
The weight ratio (AN / MAN) of acrylonitrile (AN) and methacrylonitrile (MAN) is not particularly limited, but is preferably 3/97 to 90/10, more preferably 4/96 to 70/30, particularly Preferably it is 4 / 96-60 / 40. When AN / MAN is less than 3/97, gas barrier properties are low, and sufficient expansion performance may not be obtained. On the other hand, when AN / MAN exceeds 90/10, heat resistance is low, and sufficient expansion performance may not be obtained.

The carboxyl group-containing monomer is not particularly limited as long as it has one or more free carboxyl groups per molecule. For example, unsaturated monomers such as acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, cinnamic acid, etc. Monocarboxylic acids; unsaturated dicarboxylic acids such as maleic acid, itaconic acid, fumaric acid, citraconic acid, chloromaleic acid; anhydrides of unsaturated dicarboxylic acids; monomethyl maleate, monoethyl maleate, monobutyl maleate, monomethyl fumarate, And unsaturated dicarboxylic acid monoesters such as monoethyl fumarate, monomethyl itaconate, monoethyl itaconate and monobutyl itaconate. These carboxyl group-containing monomers may be used alone or in combination of two or more. In the carboxyl group-containing monomer, some or all of the carboxyl groups may be neutralized during polymerization or after polymerization. Among the carboxyl group-containing monomers, acrylic acid, methacrylic acid, maleic acid, maleic anhydride and itaconic acid are preferable, acrylic acid and methacrylic acid are more preferable, and methacrylic acid is particularly preferable because of high gas barrier properties. Hereinafter, acrylic acid or methacrylic acid may be collectively referred to as (meth) acrylic acid, and (meth) acryl means acrylic or methacrylic.
The weight ratio of the carboxyl group-containing monomer is not particularly limited, but is preferably 10 to 95 with respect to the monomer component from the viewpoint of enhancing the heat resistance and solvent resistance of the thermally expandable microspheres. % By weight, more preferably 20 to 90% by weight, still more preferably 30 to 85% by weight, particularly preferably 40 to 80% by weight or less, and most preferably 50 to 75% by weight. When the carboxyl group-containing monomer is less than 10% by weight, heat resistance and solvent resistance are insufficient, and the expansion start temperature and maximum expansion temperature may be lowered. Further, when the carboxyl group-containing monomer exceeds 95% by weight, the expansion performance of the thermally expandable microsphere may be lowered.

When the polymerizable component contains a nitrile monomer as an essential component together with a carboxyl group-containing monomer as a monomer component, the weight ratio of the mixture of the carboxyl group-containing monomer and the nitrile monomer is simply Preferably, it is 50% by weight or more, more preferably 60% by weight or more, further preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight, based on the monomer component. That's it.
At this time, the mixing ratio of the carboxyl group-containing monomer in the mixture of the carboxyl group-containing monomer and the nitrile monomer is preferably 10 to 95% by weight, more preferably 30 to 90% by weight, and still more preferably. It is 40 to 85% by weight, particularly preferably 50 to 80% by weight. When the carboxyl group-containing monomer is less than 10% by weight, the heat resistance and solvent resistance are not sufficiently improved, and the expansion start temperature and the maximum expansion temperature may be lowered. On the other hand, when the carboxyl group-containing monomer exceeds 90% by weight, the expansion performance of the thermally expandable microspheres may be lowered.

In addition to the nitrile monomer or carboxyl group-containing monomer as the monomer component, the polymerizable component may be used in combination of one or more other monomer components. Moreover, a polymeric component does not contain the nitrile-type monomer and carboxyl group-containing monomer as a monomer component, and may consist only of 1 type, or 2 or more types of other monomer components.
Other monomer components are not particularly limited. For example, vinyl halide monomers such as vinyl chloride; vinylidene halide monomers such as vinylidene chloride; vinyl acetate, vinyl propionate, and butyrate. Vinyl ester monomers such as methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate , Phenyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate and other (meth) acrylate monomers; acrylamide, substituted acrylamide , Methacrylami (Meth) acrylamide monomers such as substituted methacrylamide; maleimide monomers such as N-phenylmaleimide and N-cyclohexylmaleimide; styrene monomers such as styrene and α-methylstyrene; ethylene, propylene, Ethylene unsaturated monoolefin monomers such as isobutylene; vinyl ether monomers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; vinyl ketone monomers such as vinyl methyl ketone; N-vinyl carbazole, N- Examples thereof include N-vinyl monomers such as vinyl pyrrolidone; vinyl naphthalene salts and the like.

Other monomer components include at least selected from (meth) acrylic acid ester monomers, styrene monomers, vinyl ester monomers, acrylamide monomers, and vinylidene halide monomers It is preferable to include one kind.
When the polymerizable component contains a vinylidene chloride monomer as a monomer component, gas barrier properties are improved. Moreover, when the polymerizable component contains a (meth) acrylic acid ester monomer and / or a styrene monomer as a monomer component, it becomes easy to control thermal expansion characteristics. When the polymerizable component contains a (meth) acrylamide monomer as a monomer component, the heat resistance is improved.

The weight ratio of at least one selected from vinylidene chloride, (meth) acrylic acid ester monomer, (meth) acrylamide monomer and styrene monomer is preferably 50 with respect to the monomer component. It is less than wt%, more preferably less than 30 wt%, particularly preferably less than 10 wt%. If it is contained in an amount of 50% by weight or more, the heat resistance may be lowered.
When the polymerizable component contains a carboxyl group-containing monomer as a monomer component, the polymerizable component contains a monomer that reacts with the carboxyl group of the carboxyl group-containing monomer as a monomer component. Also good. In the case of further containing a monomer that reacts with a carboxyl group, the heat resistance is further improved, and the expansion performance at a high temperature is improved. Examples of the monomer that reacts with the carboxyl group include N-methylol (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, vinyl glycidyl ether, and propenyl. Glycidyl ether, glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, etc. Can be mentioned. The weight ratio of the monomer that reacts with the carboxyl group is preferably 0.1 to 10% by weight, more preferably 3 to 5% by weight, based on the monomer component.

The polymerizable component may contain a polymerizable monomer (crosslinking agent) having two or more polymerizable double bonds in addition to the monomer component. By polymerizing using a crosslinking agent, a decrease in the retention rate (encapsulation retention rate) of the encapsulated foaming agent at the time of thermal expansion is suppressed, and thermal expansion can be effectively performed.
Although it does not specifically limit as a crosslinking agent, For example, aromatic divinyl compounds, such as divinylbenzene; Allyl methacrylate, triacryl formal, triallyl isocyanate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1 , 4-butanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, PEG # 200 di (meth) acrylate, PEG # 600 di (meth) acrylate, trimethylolpropane trimethacrylate, pentaerythrul Examples include di (meth) acrylate compounds such as tall tri (meth) acrylate, dipentaerythritol hexaacrylate, and 2-butyl-2-ethyl-1,3-propanediol diacrylate. These crosslinking agents may be used alone or in combination of two or more.

The amount of the crosslinking agent is not particularly limited, but is preferably 0 to 5 parts by weight, more preferably 0.1 to 1 part by weight, and particularly preferably 0.2 parts by weight with respect to 100 parts by weight of the monomer component. More than 1 part by weight and less than 1 part by weight.
The heat-expandable microspheres are preferably surface-treated with a metal-containing organic compound, and the thermoplastic resin constituting the outer shell of the heat-expandable microspheres polymerizes a polymerizable component containing a carboxyl group-containing monomer. More preferably, it is composed of the resulting copolymer. By this surface treatment, a crosslinked structure of metal is formed in the vicinity of the outer surface of the outer shell made of the thermoplastic resin. This metal cross-linked structure is based on chemical bonds such as covalent bonds (including coordination bonds) between the anionic carboxylate group derived from the carboxyl group-containing monomer and contained in the thermoplastic resin, and the metal. It is considered that the structure is formed by This structure is preferably a cross-linked structure (metal cross-linked structure) in which a plurality of carboxylate groups are linked through a metal. When the metal is A and the electronic valence is p, the crosslinked structure is represented, for example, as (—COO) _p A. Here, when p is 2, it is represented as (—COO) ₂ A, that is, —COO—A—OCO—. The cross-linked structure of the metal is not easily destroyed by washing the thermally expandable microspheres with water, and the heat resistance is improved.

Examples of the metal that forms the crosslinked structure include group 3 metals such as scandium, ytterbium, and cerium; group 4 metals such as titanium, zirconium, and hafnium; group 5 metals such as vanadium, niobium, and tantalum; chromium, molybdenum, Group 6 metals such as tungsten; Group 7 metals such as manganese and rhenium; Group 8 metals such as iron, ruthenium and osmium; Group 9 metals such as cobalt and rhodium; Group 10 metals such as nickel and palladium; Copper, silver and gold 11 group metals, such as; Group 12 metals, such as zinc and cadmium, etc. can be mentioned. These metals may be used alone or in combination of two or more. The above metal classification is “Chemical and Education” published by the Chemical Society of Japan, Volume 54, No. 4 (2006), and the “Periodic Table of Elements (2005)” (2006 The Chemical Society of Japan atomic weight) Subcommittee).
Among these metals, transition metals (metals belonging to Groups 3 to 11) are preferable, metals belonging to Groups 4 to 10 are more preferable, and metals belonging to Groups 4 to 5 are particularly preferable.

Examples of transition metals include scandium, ytterbium, cerium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, rhenium, iron, ruthenium, osmium, cobalt, rhodium, nickel, palladium, copper , Silver, gold and the like. Among these, scandium, ytterbium, titanium, zirconium, vanadium, niobium, chromium, molybdenum, manganese, iron, ruthenium, cobalt, rhodium, nickel, palladium, copper, silver, and the like are preferable, and periodic table 4 such as titanium, zirconium, and vanadium. Transition metals belonging to ˜5 periods are more preferable from the viewpoint of improving heat resistance. When it is not a transition metal, the improvement of heat resistance may be insufficient.
The valence number of the metal is not particularly limited, but is preferably 2 to 5 valence, more preferably 3 to 5 valence, and particularly preferably 4 to 5 valence in terms of crosslinking efficiency per metal atom. When the valence number is monovalent, the solvent resistance and water resistance of the thermally expandable microsphere may be lowered. Moreover, the crosslinking efficiency may fall that it is 6 or more.

Regarding the above metal, the combination of metal species and valence number thereof is zinc (II), cadmium (II), aluminum (III), vanadium (III), ytterbium (III), titanium from the viewpoint of improving heat resistance. (IV), zirconium (IV), lead (IV), cerium (IV), vanadium (V), niobium (V), tantalum (V) and the like are preferable.
When the metal contained in the thermally expandable microspheres contains a metal belonging to Group 3-12 of the periodic table, the weight ratio is preferably 0.05 to 15% by weight of the thermally expandable microspheres, more preferably 0. 10 to 7% by weight, more preferably 0.13 to 5% by weight, further preferably 0.14 to 3% by weight, more preferably 0.15 to 1.5% by weight, and particularly preferably 0.16 to 0%. 0.8% by weight, most preferably 0.20 to 0.54% by weight. If the weight ratio of the metal belonging to Group 3-12 of the periodic table is less than 0.05% by weight, the heat resistance may not be improved sufficiently. On the other hand, when the weight ratio of the metal exceeds 15% by weight, the outer shell becomes stiff and the maximum expansion ratio may be lowered. When the metal contained in the thermally expansible microsphere includes a metal belonging to the periodic table group 3 to 11, when including a metal belonging to the periodic table group 4 to 10, or when including a metal belonging to the periodic table group 4 to 5 However, it is preferable that the weight ratio is the above-described weight ratio.
The surface treatment of the metal-containing organic compound will be described in detail in the method for producing thermally expandable microspheres described below, but is not limited to the following method.

<Method for producing thermally expandable microsphere>
The method for producing thermally expandable microspheres is a step of polymerizing a polymerizable component in an aqueous dispersion medium in which an oily mixture containing a polymerizable component and a foaming agent described above is dispersed (hereinafter referred to as a polymerization step). A manufacturing method including:

In the polymerization step, it is preferable to polymerize the polymerizable component in the presence of the polymerization initiator using an oily mixture containing a polymerization initiator.
Although there is no limitation in particular as a polymerization initiator, A peroxide, an azo compound, etc. can be mentioned.

Examples of the peroxide include diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-2-octyl peroxydicarbonate, and dibenzyl peroxydicarbonate. Peroxydicarbonates such as t-butyl peroxypivalate, t-hexyl peroxypivalate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-butylperoxy 3,5,5-trimethyl Examples thereof include peroxyesters such as hexanoate; diacyl peroxides such as lauroyl peroxide and benzoyl peroxide.
Examples of the azo compound include 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4- Dimethylvaleronitrile), 2,2'-azobis (2-methylpropionate), 2,2'-azobis (2-methylbutyronitrile), and the like. These polymerization initiators may be used alone or in combination of two or more. As the polymerization initiator, an oil-soluble polymerization initiator soluble in the monomer component is preferable. Among the polymerization initiators, peroxydicarbonate is preferable. When the polymerization initiator includes other initiators together with peroxydicarbonate, the proportion of peroxydicarbonate in the polymerization initiator is preferably 60% by weight or more.

Although there is no limitation in particular about the quantity of a polymerization initiator, it is preferable in it being 0.3-8.0 weight part with respect to 100 weight part of said monomer components.
In the polymerization step, the oily mixture may further contain a chain transfer agent and the like.

The aqueous dispersion medium is a medium mainly composed of water such as ion exchange water in which the oily mixture is dispersed. Although there is no limitation in particular about the usage-amount of an aqueous dispersion medium, it is preferable to use 100-1000 weight part aqueous dispersion medium with respect to 100 weight part of polymeric components.
The aqueous dispersion medium may further contain an electrolyte. Examples of the electrolyte include sodium chloride, magnesium chloride, calcium chloride, sodium sulfate, magnesium sulfate, ammonium sulfate, and sodium carbonate. These electrolytes may be used alone or in combination of two or more. Although there is no limitation in particular about content of an electrolyte, it is preferable to contain 0.1-50 weight part with respect to 100 weight part of aqueous dispersion media.

An aqueous dispersion medium is a water-soluble 1,1-substituted compound having a structure in which a hydrophilic functional group selected from a hydroxyl group, a carboxylic acid (salt) group, and a phosphonic acid (salt) group and a hetero atom are bonded to the same carbon atom , Potassium dichromate, alkali metal nitrite, metal (III) halide, boric acid, water-soluble ascorbic acids, water-soluble polyphenols, water-soluble vitamin Bs and water-soluble phosphonic acids (salts) It may contain at least one water-soluble compound. In addition, the water solubility in this invention means the state which melt | dissolves 1g or more per 100g of water.
The amount of the water-soluble compound contained in the aqueous dispersion medium is not particularly limited, but is preferably 0.0001 to 1.0 part by weight, more preferably 0.0003 to 100 parts by weight of the polymerizable component. 0.1 parts by weight, particularly preferably 0.001 to 0.05 parts by weight. If the amount of the water-soluble compound is too small, the effect of the water-soluble compound may not be sufficiently obtained. Moreover, when there is too much quantity of a water-soluble compound, a polymerization rate may fall or the residual amount of the polymeric component which is a raw material may increase.

The aqueous dispersion medium may contain a dispersion stabilizer and a dispersion stabilization auxiliary agent in addition to the electrolyte and the water-soluble compound.
The dispersion stabilizer is not particularly limited, and examples thereof include tricalcium phosphate, magnesium pyrophosphate, calcium pyrophosphate obtained by a metathesis generation method, colloidal silica, alumina sol, magnesium hydroxide and the like. These dispersion stabilizers may be used alone or in combination of two or more.

The blending amount of the dispersion stabilizer is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the polymerizable component.
The dispersion stabilizing aid is not particularly limited, and examples thereof include a polymer type dispersion stabilizing aid, a cationic surfactant, an anionic surfactant, an amphoteric surfactant, and a nonionic surfactant. Mention may be made of activators. These dispersion stabilizing aids may be used alone or in combination of two or more.

The aqueous dispersion medium is prepared, for example, by blending water (ion-exchanged water) with a water-soluble compound and, if necessary, a dispersion stabilizer and / or a dispersion stabilizing aid. The pH of the aqueous dispersion medium at the time of polymerization is appropriately determined depending on the type of the water-soluble compound, the dispersion stabilizer, and the dispersion stabilization aid.
In the polymerization step, polymerization may be performed in the presence of sodium hydroxide, sodium hydroxide and zinc chloride.

In the polymerization step, the oily mixture is emulsified and dispersed in an aqueous dispersion medium so that spherical oil droplets having a predetermined particle diameter are prepared.
Examples of the method for emulsifying and dispersing the oily mixture include, for example, a method of stirring with a homomixer (for example, manufactured by Primix Co., Ltd.) and the like, and a method of using a static dispersion device such as a static mixer (for example, manufactured by Noritake Engineering Co., Ltd.). And general dispersion methods such as a membrane emulsification method and an ultrasonic dispersion method.

Next, suspension polymerization is started by heating the dispersion in which the oily mixture is dispersed as spherical oil droplets in the aqueous dispersion medium. During the polymerization reaction, it is preferable to stir the dispersion, and the stirring may be performed so gently as to prevent, for example, floating of the monomer and sedimentation of the thermally expandable microspheres after polymerization.
Although superposition | polymerization temperature is freely set by the kind of polymerization initiator, Preferably it is 30-100 degreeC, More preferably, it controls in the range of 40-90 degreeC. The time for maintaining the reaction temperature is preferably about 0.1 to 20 hours. Although there is no limitation in particular about the superposition | polymerization initial pressure, it is the range of 0-5.0 MPa by gauge pressure, More preferably, it is the range of 0.1-3.0 MPa.

Next, the thermally expandable microsphere, which is surface-treated with a metal-containing organic compound or has a cross-linked structure formed of a metal in the vicinity of the outer surface of the outer shell made of a thermoplastic resin, for example, Using the thermally expandable microspheres obtained in the polymerization step as raw microspheres, the following surface treatment process is performed. Here, the heat-expandable microspheres obtained in the polymerization step are heat composed of a copolymer obtained by polymerizing a polymerizable component containing a carboxyl group-containing monomer with a thermoplastic resin as an outer shell. It may be an expandable microsphere.
The surface treatment step is a step of subjecting the raw material microspheres to a surface treatment with a metal-containing organic compound. The surface treatment is a treatment of bringing the raw material microspheres into contact with the metal-containing organic compound. The surface treatment here does not originally intend to physically attach the metal-containing organic compound to the outer surface of the outer shell of the raw material microspheres. The purpose of the surface treatment is, for example, a crosslinked structure (metal crosslinked structure) by linking anionic carboxylate groups contained in the thermoplastic resin that forms the outer shell of the raw material microspheres via a metal. Is chemically formed. The heat resistance is improved by forming the metal bridge structure in the vicinity of the outer surface of the outer shell. The crosslinking efficiency means the formation efficiency of metal crosslinking.
The metal-containing organic compound is not particularly limited, but is preferably water-soluble from the viewpoint of surface treatment efficiency. The metal contained in the metal-containing organic compound is as described above.

The metal-containing organic compound is preferably a compound having at least one bond represented by the following general formula (1) and / or a metal amino acid compound.
M-O-C (1)
(However, M is a metal atom belonging to Groups 3 to 12 of the periodic table, and carbon atom C is bonded to oxygen atom O, and in addition to oxygen atom O, only hydrogen atom and / or carbon atom is bonded.)
First, the compound having at least one bond represented by the general formula (1) will be described in detail.

-Compound having at least one bond represented by the general formula (1)-
The bond between the metal atom and the oxygen atom represented by the general formula (1) (the bond between MO) may be either an ionic bond or a covalent bond (including a coordination bond). preferable.
When the compound having at least one bond represented by the general formula (1) is a compound having a metal-alkoxide bond and / or a metal-aryloxide bond, it has high solvent resistance and is stable in a wide range of high temperatures. Expansion performance can be imparted to thermally expandable microspheres. Hereinafter, for the sake of simplicity, “metal-alkoxide bond and / or metal-aryl oxide bond” will be referred to as “MO bond”, and “compound having metal-alkoxide bond and / or metal-aryl oxide bond” will be referred to as “ It may be described as “MO compound”.

The MO compound is a compound having at least one metal-alkoxide bond or metal-aryloxide bond. MO compounds include metal-O—C═O bond (metal-acylate bond), metal-OCON bond (metal-carbamate bond), metal = O bond (metal oxy bond), and the following general formula (2) (formula R ¹ and R ² are organic groups which may be the same or different from each other.) Further, it has a bond to a metal which is not an MO bond, such as a metal-acetylacetonate bond shown in the above. You may do it. M represents a metal.

As is apparent from the above, the MO bond and the metal-O—C═O bond (metal-acylate bond) are different concepts, and the metal-O—C═O bond (metal-acylate bond) has an MO. There is no binding.
The MO compound is classified into, for example, the following four compounds (1) to (4).

Compound (1):
Compound (1) is a metal alkoxide and a metal aryloxide, for example, a compound represented by the following chemical formula (A).
M (OR) _n (A)
(However, M represents a metal; n is a valence number of the metal M; R is a hydrocarbon group having 1 to 20 carbon atoms, and each n hydrocarbon group is the same or different. It may be linear, branched or cyclic.)

In compound (1), M (metal) and n (valence number) are as described above.
R may be aliphatic or aromatic, and may be saturated or unsaturated. R may be, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 2-ethylhexyl, allyl, n-decyl, tridecyl, stearyl. Group, an aliphatic hydrocarbon group such as a cyclopentyl group; an aromatic hydrocarbon group such as a phenyl group, a toluyl group, a xylyl group, and a naphthyl group.

  Examples of the compound (1) include zinc (II) alkoxides such as diethoxy zinc and diisopropoxy zinc; aluminum (III) alkoxides such as aluminum triisopropoxide and aluminum triethoxide; vanadium triethoxide and vanadium triiso Vanadium (III) alkoxides such as propoxide; Titanium (IV) such as tetramethoxy titanium, tetraethoxy titanium, tetraisopropoxy titanium, tetra normal propoxy titanium, tetra normal butoxide titanium, tetrakis (2-ethylhexyloxy) titanium, tetraphenoxy titanium ) Alkoxide; tetramethoxyzirconium, tetraethoxyzirconium, tetraisopropoxyzirconium, tetranormalpropoxyzirconium, tetranor Zirconium (IV) alkoxides such as rubutoxyzirconium, tetrakis (2-ethylhexyloxy) zirconium, tetraphenolatezirconium; tetramethoxycerium, tetraethoxycerium, tetraisopropoxycerium, tetranormalpropoxycerium, tetranormalbutoxycerium, tetrakis ( Cerium (IV) alkoxides such as 2-ethylhexyloxy) cerium and tetraphenolate cerium; trimethoxyoxyvanadium, triethoxyoxyvanadium, tri (n-propoxy) oxyvanadium, isopropoxyoxyvanadium, tri (n-butoxide) oxy Alkoxyoxyvanadium (V) such as vanadium, isobutoxyoxyvanadium; others, tantalum, manganese, co Belt, the metal of the metal alkoxide such as copper and the like.

Compound (2):
The compound (2) is an oligomer or polymer of the compound (1) and is generally obtained by condensing the compound (1). Compound (2) is, for example, a compound represented by the following chemical formula (B). The chemical formula (B) shows a partially hydrolyzed structure.
RO [-M (OR) ₂ O-] _x-1 R (B)
(However, M and R are the same as chemical formula (A); x is an integer of 2 or more.)

The molecular weight of the compound (2) is not particularly limited, but the number average molecular weight is preferably 200 to 5000, particularly preferably 300 to 3000. If the number average molecular weight is less than 200, the crosslinking efficiency may be low. On the other hand, if the number average molecular weight exceeds 5000, it may be difficult to control the degree of crosslinking.
Examples of the compound (2) include titanium alkoxy polymers and titanium alkoxy dimers that satisfy x = 2 to 15 in the chemical formula (B).

Specific examples of the compound (2) include, for example, titanium methoxy polymers such as hexamethyl dititanate and octamethyl trititanate; titanium ethoxy polymers such as hexaethyl dititanate and octaethyl trititanate; hexaisopropyl dititanate and octaisopropyl tritate. Titanium propoxy polymer such as titanate, hexanormal propyl dititanate, octa normal propyl trititanate, etc .; Titanium butoxy polymer such as hexabutyl dititanate, octabutyl trititanate, etc .; Titanium phenoxy polymer such as hexaphenyl dititanate, octaphenyl trititanate; hydroxy titanium stearate (formula: _i-C 3 _{H 7} O _{[Ti (OH) (OCOC 17 H} 35) O ] _{n -i-C} 3 _{H 7)} or the like Al of Kishichitan - acylate polymer; titanium methoxy dimer, titanium ethoxy dimer, titanium butoxy dimer, and titanium alkoxy dimers such as titanium phenoxy dimer.

Compound (3):
Compound (3) is a metal chelate compound having an MO bond. In the compound (3), a ligand compound having at least one MO bond and having at least one electron donating group selected from a hydroxyl group, a keto group, a carboxyl group and an amino group is coordinated to M Metal chelate compound. The ligand compound may have at least one electron donating group, but preferably has 2 to 4 electron donating groups. Compound (3) may have a plurality of MO bonds, M, and a ligand compound.
The ligand compound is not particularly limited, and examples thereof include alkanolamines, carboxylic acids, hydroxycarboxylic acids (salts), β-diketones, β-ketoesters, diols and amino acids.

Examples of alkanolamines include ethanolamine, diethanolamine, and triethanolamine.
Examples of carboxylic acids include acetic acid and the like.

Examples of hydroxycarboxylic acids (salts) include glycolic acid, lactic acid, malic acid, citric acid, tartaric acid, salicylic acid, and salts thereof.
Examples of β-diketone include acetylacetone and the like.

Examples of the β-ketoester include ethyl acetoacetate and the like.
Examples of diols include ethylene glycol, diethylene glycol, 3-methyl-1,3-butanediol, triethylene glycol, dipropylene glycol, 1,3-propanediol, 1,3-butanediol, and 1,5-pentanediol. Hexylene glycol, octylene glycol and the like.

  Examples of the compound (3) in which the ligand compound is an alkanolamine include, for example, titanium tetrakis (diethanolaminate), isopropoxytitanium tris (diethanolamate), diisopropoxytitanium bis (diethanolaminate), triisopropoxytitanium mono ( Diethanolaminate), dibutoxytitanium bis (diethanolamate), titanium tetrakis (triethanolamate), dimethoxytitanium bis (triethanolamate), diethoxytitanium bis (triethanolamate), isopropoxytitanium tris (triethanolamate) , Diisopropoxytitanium bis (triethanolamate), triisopropoxytitanium mono (triethanolamate), di-n-butoxytitanium Alkanolamine-alkoxytitanium chelate compounds such as tris (triethanolaminate); zirconium tetrakis (diethanolaminate), isopropoxyzirconium tris (diethanolamate), diisopropoxyzirconium bis (diethanolaminate), triisopropoxyzirconium mono (diethanolamin ), Dibutoxyzirconium bis (diethanolaminate), zirconium tetrakis (triethanolamate), dimethoxyzirconium bis (triethanolamate), diethoxyzirconium bis (triethanolamate), isopropoxyzirconium tris (triethanolaminate) Nate), diisopropoxyzirconium bis (triethanolamate), tri Alkanolamine-alkoxyzirconium chelate compounds such as sopropoxyzirconium mono (triethanolaminate) and di-n-butoxyzirconium bis (triethanolaminate); cerium tetrakis (diethanolaminate), isopropoxycerium tris (diethanolaminate), Diisopropoxycerium bis (diethanolamate), triisopropoxycerium mono (diethanolamate), dibutoxycerium bis (diethanolamate), cerium tetrakis (triethanolamate), dimethoxycerium bis (triethanolamate), diethoxy Cerium bis (triethanolaminate), isopropoxycerium tris (triethanolamate), diisopro Examples thereof include alkanolamine-alkoxycerium chelate compounds such as poxycerium bis (triethanolamate), triisopropoxycerium mono (triethanolamate), and di-n-butoxycerium bis (triethanolamate).

  Examples of the compound (3) in which the ligand compound is a hydroxycarboxylic acid (salt) include, for example, titanium lactate, dihydroxy titanium bis (lactate), dihydroxy titanium bis (lactate) monoammonium salt, dihydroxy titanium bis (lactate) diammonium salt, Hydroxycarboxylic acid (salt) -alkoxytitanium chelate compound such as dihydroxytitanium bis (glycolate), titanium lactate ammonium salt; zirconium lactate, monohydroxyzirconium tris (lactate), dihydroxyzirconium bis (lactate), dihydroxyzirconium bis (lactate) mono Ammonium salt, dihydroxyzirconium bis (lactate) diammonium salt, dihydroxyzirconium bis (glycolate), di Hydroxycarboxylic acid (salt) -alkoxyzirconium chelate compounds such as ammonium lactate ammonium salt; cerium lactate, monohydroxycerium tris (lactate), dihydroxycerium bis (lactate), dihydroxycerium bis (lactate) monoammonium salt, dihydroxycerium bis Examples thereof include hydroxycarboxylic acid (salt) -alkoxycerium chelate compounds such as (lactate) diammonium salt, dihydroxycerium bis (glycolate), and cerium lactate ammonium salt.

Examples of the compound (3) in which the ligand compound is a β-diketone include alkoxy zinc-β-diketone chelate compounds such as zinc acetylacetonate; β-diketone-alkoxyaluminum chelate compounds such as aluminum acetylacetonate; vanadium Β-diketone-alkoxyvanadium chelate compounds such as acetylacetonate; titanium tetrakis (acetylacetonate), dimethoxytitanium bis (acetylacetonate), diethoxytitanium bis (acetylacetonate), diisopropoxytitanium bis (acetylacetate), dinormal Propoxytitanium bis (acetylacetonate), dibutoxytitanium bis (acetylacetonate), titanium tetrakis (2,4-hexanedionate), titanium tetrakis (3,5-he Β-diketone chelate-alkoxytitanium compounds such as Tandionato; dihydroxyzirconium bis (acetylacetonate), zirconium tetrakis (acetylacetonate), tributoxyzirconium mono (acetylacetonate), dibutoxyzirconium bis (acetylacetonate), Β-diketone-alkoxyzirconium chelate compounds such as monobutoxyzirconium tris (acetylacetonate); dihydroxycerium bis (acetylacetonate), cerium tetrakis (acetylacetonate), tributoxycerium mono (acetylacetonate), dibutoxycerium Β-diketone-alkoxycerium chelates such as bis (acetylacetonate) and monobutoxycerium tris (acetylacetonate) Compounds and the like.
Examples of the compound (3) in which the ligand compound is a β-ketoester include β-ketoester-alkoxytitanium chelate compounds such as diisopropoxytitanium bis (ethylacetoacetate); dibutoxyzirconium bis (ethylacetoacetate) and the like Examples include β-ketoester-alkoxyzirconium chelate compounds.

Examples of the compound (3) in which the ligand compound is a β-diketone and β-ketoester include alkoxytitanium-β-diketone and β-ketoester such as monobutoxytitanium mono (acetylacetonate) bis (ethylacetoacetate) Chelate compounds; β-diketones such as monobutoxyzirconium mono (acetylacetonate) bis (ethylacetoacetate) and β-ketoester-alkoxyzirconium chelate compounds; monobutoxycerium mono (acetylacetonate) bis (ethylacetoacetate) Examples include β-diketone and β-ketoester-alkoxycerium chelate compound.
Examples of the compound (3) in which the ligand compound is a diol include alkoxy titanium-diol chelate compounds such as dioctyloxy titanium bis (octylene glycolate).
The compound (3) may be a metal chelate compound in which the ligand compound is coordinated to a metal atom such as tantalum, manganese, cobalt, copper, or the like, or a derivative thereof.

Compound (4):
The compound (4) is a compound having at least one MO bond and metal-acylate bond.
Compound (4) is, for example, a compound represented by the following chemical formula (C).
M (OCOR ¹ ) _nm (OR) _m (C)
(However, M, n, and R are the same as chemical formula (A); R ¹ is the same as R, but may be the same or different; Is a positive integer that satisfies.)

Compound (4) may be obtained by condensation of the compound represented by chemical formula (C).
Examples of the compound (4) include alkoxytitanium-acylate compounds such as tributoxyzirconium monostearate; alkoxyzirconium-acylate compounds such as tributoxyzirconium monostearate; alkoxycerium-acylate compounds such as tributoxycerium monostearate Etc.

-Metal amino acid compounds-
The metal-containing organic compound may be a metal amino acid compound. The metal amino acid compound is an amino acid chelate metal compound obtained by a reaction between a metal salt belonging to Groups 3 to 12 of the periodic table and amino acids shown below.
Amino acids include not only amino acids having an amino group (—NH ₂ ) and a carboxyl group (—COOH) in the same molecule, but also iminos such as proline and hydroxyproline having an imino group (—NH) instead of an amino group. Also includes acids. The amino acid is usually an α-amino acid, but may be a β, γ, δ or ω-amino acid.

Amino acids include amino acid derivatives such as those in which one or two hydrogen atoms of the amino group of the amino acid are substituted, and complexes chelated with nitrogen of the amino acid amino group and oxygen of the carboxyl group.
The pH of amino acids is preferably 1-7.

Examples of amino acids include dihydroxymethyl glycine, dihydroxyethyl glycine, dihydroxypropyl glycine, dihydroxybutyl glycine, glycine, alanine, valine, leucine, isoleucine, serine, histidine, threonine, glycylglycine, 1-aminocyclopropane carboxylic acid 1-aminocyclohexanecarboxylic acid, 2-aminocyclohexanehydrocarboxylic acid, and the like. Among these, dihydroxyethyl glycine, glycine, serine, threonine, and glycylglycine are preferable from the viewpoint of crosslinking efficiency.
As a metal salt belonging to Groups 3-12 of the periodic table that reacts with the amino acids, basic zirconyl chloride is preferred. As a commercial item of a metal amino acid compound, for example, ORGATICS ZB-126 (manufactured by Matsumoto Pharmaceutical Co., Ltd.) and the like can be mentioned.

Among the above metal-containing organic compounds, dioctyloxy titanium bis (octylene glycolate), titanium butoxy dimer, titanium tetrakis (acetylacetonate), diisopropoxy titanium bis (ethyl acetoacetate), diisopropoxy titanium bis (triethanolaminate) ), Dihydroxytitanium bis (lactate), dihydroxytitanium bis (lactate) monoammonium salt, zirconium tetrakis (acetylacetonate), dihydroxytitanium bis (lactate) diammonium salt, triisopropoxyoxyvanadium, reaction product of zirconium chloride and aminocarboxylic acid (Orugatics ZB-126) and the like are preferable in terms of heat resistance improvement efficiency and handling properties.
In the surface treatment step, the molar ratio of the metal-containing organic compound (the number of moles of the metal-containing organic compound / the number of moles of the carboxyl group-containing monomer as the raw material of the raw material microspheres) is not particularly limited, but is preferably 0. 0.001 to 1.0, more preferably 0.005 to 0.5, still more preferably 0.007 to 0.3, particularly preferably 0.009 to 0.15, and most preferably 0.009 to 0.06. It is. When the molar ratio of the metal-containing organic compound is less than 0.001, there is little effect of improving heat resistance, and the expansion performance may be deteriorated when exposed to a high temperature environment for a long time. On the other hand, when the molar ratio of the metal-containing organic compound exceeds 1.0, the outer shell of the thermally expandable microsphere becomes too strong, the expansion performance may be decreased, and the heat insulation may be decreased.

The surface treatment step is not particularly limited as long as it is a treatment step for bringing the raw material microspheres into contact with the metal-containing organic compound. However, it is preferable to mix the raw material microspheres and the metal-containing organic compound with the aforementioned aqueous dispersion medium. . Accordingly, the metal-containing organic compound is preferably water-soluble.
When the surface treatment step is performed in an aqueous dispersion medium, the weight ratio of the raw material microspheres to the dispersion mixture containing the raw material microspheres, the metal-containing organic compound and the aqueous dispersion medium is preferably 1 to 50% by weight, more preferably 3%. -40% by weight, more preferably 5-35% by weight. When the weight ratio of the raw material microspheres is less than 1% by weight, the processing efficiency may be lowered. On the other hand, when the weight ratio of the raw material microspheres exceeds 50% by weight, the processing may be nonuniform.

The weight ratio of the metal-containing organic compound in the dispersion mixture is not particularly limited as long as it can be uniformly treated, but is preferably 0.1 to 20% by weight, and more preferably 0.5 to 15% by weight. When the weight ratio of the metal-containing organic compound is less than 0.1% by weight, the treatment efficiency may be lowered. On the other hand, if the weight ratio of the metal-containing organic compound is more than 20% by weight, the treatment may be nonuniform.
Moreover, the aqueous dispersion medium used for the surface treatment is usually an aqueous dispersion medium used for the preparation of the raw material microspheres or an aqueous dispersion medium containing newly prepared water, but if necessary, methanol, ethanol and Alcohols such as propanol; aliphatic hydrocarbons such as hexane, isooctane and decane; hydroxycarboxylic acids such as glycolic acid, lactic acid, malic acid, citric acid and salicylic acid and salts thereof (for example, lithium salt, sodium salt, potassium salt, ammonium) Salts, amine salts, etc.); ethers such as tetrahydrofuran, dialkyl ethers and diethyl ether; surfactants; may contain other components such as antistatic agents.

In the surface treatment step, the heat-expandable microspheres may be produced using the polymerization liquid containing the raw material microspheres obtained in the polymerization step as it is. In addition, a series of isolation operations such as filtration and washing are performed on the polymerization solution obtained in the polymerization step, and if necessary, the raw material microspheres are once separated from the polymerization solution, followed by a surface treatment step. Thermally expandable microspheres may be manufactured.
When the aqueous dispersion medium contains other components, for example, the surface treatment step can be performed by the following methods A) to D).

A) Method of mixing component 1 containing other components and raw material microspheres and component 2 containing metal-containing organic compound B) Component 1 containing metal-containing organic compound and raw material microspheres and component containing other components 2) Method 2 of mixing other components and component 1 containing a metal-containing organic compound and component 2 containing raw material microspheres D) Component 1 containing raw material microspheres and other components Method of simultaneously mixing component 2 and component 3 containing a metal-containing organic compound (at least one of the above components 1 to 3 contains water. Two or three components may contain water) .)
The surface treatment step may be performed by a method other than that described above, for example, the following methods 1) and 2).

1) Surface treatment on moistened raw material microspheres (wet cake-like raw material microspheres) The raw material microspheres, the metal-containing organic compound, and the aqueous dispersion medium are contained (uniformly), and the weight ratio of the raw material microspheres is A mixture that is preferably 50% by weight or more, more preferably 60% by weight or more, and particularly preferably 70% by weight or more is prepared, and the aqueous dispersion medium is removed by operations such as airflow drying or heat drying under reduced pressure to thermally expand To obtain sex microspheres.
2) Surface treatment on (almost) dried raw material microspheres A metal-containing organic compound is added to dried raw material microspheres in which the weight ratio of the raw material microspheres is preferably 90% by weight or more, preferably 95% by weight or more. After uniformly mixing, the volatile matter may be removed by heating to such an extent that it does not expand to obtain thermally expandable microspheres. At this time, the raw material microspheres may be left stationary, stirred, or fluidized in the air using a fluidized bed or the like. The addition of the metal-containing organic compound is preferably performed by uniformly spraying the metal-containing organic compound or the liquid containing the metal-containing organic compound with a spray or the like.

Although there is no limitation in particular about the processing temperature in a surface treatment process, Preferably it is the range of 40-150 degreeC. The time for maintaining this treatment temperature is preferably about 0.1 to 20 hours.
Although there is no limitation in particular about the pressure in a surface treatment process, Preferably it is the range of 0-5.0 MPa by a gauge pressure.

In the surface treatment step, the heat-expandable microspheres obtained by the surface treatment are usually separated from the aqueous dispersion medium by operations such as suction filtration, centrifugation, and centrifugal filtration. Furthermore, the thermally expandable microspheres can be obtained in a dry state by an operation such as air-drying and drying under reduced pressure by heating the liquid-containing cake of thermally expandable microspheres obtained after the separation. In addition, when surface-treating by the method of said 1) and 2), operation may be abbreviate | omitted suitably.
The amount of metal (for example, metal belonging to Group 3-12 of the periodic table) contained in the thermally expandable microsphere increases before and after the surface treatment process. The weight ratio of the amount of metal increased by the surface treatment step to the amount of metal contained in the thermally expandable microspheres after the surface treatment step is usually 10% by weight or more, preferably 60% by weight or more, more preferably 70% by weight. % Or more, more preferably 80% by weight, particularly preferably 90% by weight or more, and most preferably 95% by weight or more. If it is less than 10% by weight, the entire outer shell becomes rigid and may not exhibit good expansion performance.

[Organic substrate component]
The organic base material component is a component of the base material that is the counterpart to be kneaded with the thermally expandable microspheres in the master batch of the present invention. The organic base component improves the dispersibility of thermally expanded microspheres inside the foamed molded product when using a masterbatch to produce a foamed molded product, and has the effect of stabilizing the foaming ratio without variation. It is an ingredient to do.
The organic base material component is an organic material that can be mixed with the heat-expandable microspheres described above, and has an A hardness of 90 or less at (23 ± 2) ° C. In the present invention, the A hardness is a hardness measured by a type A durometer hardness test under a condition of (23 ± 2) ° C. in accordance with JIS K6253. Moreover, when A hardness exceeds 90, a type D durometer hardness test is performed and D hardness may be measured instead of A hardness.

About A hardness of an organic base material component, Preferably it is 0-90, More preferably, it is 5-87, More preferably, it is 10-85, Especially preferably, it is 20-82, Most preferably, it is 25-80. When the A hardness of the organic base material component exceeds 90, the foaming ratio of the foamed molded product produced using the master batch is unstable and the specific gravity may vary, resulting in poor appearance.
The bending elastic modulus of the organic base material component is not particularly limited, and is preferably 150 MPa or less, more preferably 100 MPa or less, and particularly preferably 80 MPa or less. A preferable lower limit of the flexural modulus of the organic base material component is 0 MPa. When the flexural modulus of the organic base material component exceeds 150 MPa, the foaming ratio of the foamed molded product produced using the master batch is unstable and the specific gravity may vary, resulting in poor appearance. In the present invention, the flexural modulus is an elastic modulus measured according to JIS K7171.

The melting point of the organic base component is not particularly limited as long as it is equal to or lower than the expansion start temperature of the thermally expandable microsphere, but is preferably 65 ° C to 200 ° C, more preferably 80 ° C to 180 ° C, and particularly preferably 100 ° C. ~ 170 ° C. When the melting point of the organic base material component is less than 65 ° C., when the master batch is charged into the molding machine, the master batch is melted in the vicinity of the raw material supply port of the molding machine, so that the supply of the master batch becomes unstable. Sometimes. On the other hand, when the melting point of the organic base material component exceeds 200 ° C., the kneading temperature becomes 200 ° C. or higher when producing a foam molded article using a master batch, and an excessive thermal history can be given to the thermally expandable microspheres. Thus, the expansion ratio of the master batch may be reduced.
There are no particular limitations on the type of organic base component, but for example, polyvinyl chloride; polyvinylidene chloride; polyvinyl alcohol; ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, ethylene-methyl (meth) Ethylene copolymers such as acrylate copolymer, ethylene-ethyl (meth) acrylate copolymer, ethylene-butyl (meth) acrylate copolymer; low density polyethylene, high density polyethylene, polypropylene, polybutene, polyisobutylene, polystyrene Polyolefin resins such as polyterpenes; styrene copolymers such as styrene-acrylonitrile copolymers and styrene-butadiene-acrylonitrile copolymers; polyacetals; polymethyl methacrylates; cellulose acetates; polycarbonates; Polyester resins such as polyethylene terephthalate and polybutylene terephthalate; Polyamide resins such as nylon 6 and nylon 66; Thermoplastic polyurethane; Tetrafluoroethylene; Ionomer resins such as ethylene ionomer, urethane ionomer, styrene ionomer, fluorine ionomer, etc. These thermoplastic resins can be mentioned.

The type of organic base component may be other than a thermoplastic resin, for example, a thermoplastic elastomer such as urethane elastomer, styrene elastomer, olefin elastomer, amide elastomer, ester elastomer; natural rubber, butyl rubber, silicon rubber Rubbers such as ethylene-propylene-diene rubber (EPDM); animal waxes such as beeswax, shellac wax, spermaceti, wool wax, ibota wax; carnauba wax, beeswax, candelilla wax, rice wax, wax Plant waxes such as wax wax, sugarcane wax, etc .; mineral waxes such as montan wax, ozokerite, ceresin; petroleum waxes such as paraffin wax and microcrystalline wax; Fischer-Tropsch wax; Triethylene waxes, synthetic waxes such as polypropylene wax.
Among the types of organic base material components, the thermoplastic elastomer is preferable because the dispersibility of the thermally expanded microspheres in the foamed molded product is improved when a foamed molded product is produced using a masterbatch. Among the thermoplastic elastomers, at least one selected from styrene elastomers, olefin elastomers, amide elastomers, ester elastomers and the like is preferable.

Examples of the olefin elastomer include a mixture of a polymer composed of a hard segment and a polymer composed of a soft segment, and a copolymer of a polymer composed of a hard segment and a polymer composed of a soft segment. .
In the olefin-based elastomer, examples of the hard segment include a segment made of polypropylene. In addition, as the soft segment, for example, polyethylene, ethylene and a small amount of a diene component copolymerized (for example, ethylene-propylene-copolymer (EPM), ethylene-propylene-diene copolymer (EPDM), EPDM) And the like, which are partially crosslinked by adding an organic peroxide to the above.

The polymer mixture or copolymer as the olefin elastomer may be graft-modified with an unsaturated hydroxy monomer and its derivative, an unsaturated carboxylic acid monomer and its derivative, and the like.
Commercially available olefin elastomers include, for example, “Sant Plain” manufactured by ExxonMobil Co., Ltd., “Vistamax”, “Exelink” manufactured by JSR Co., Ltd., “Maxilon” manufactured by Showa Kasei Kogyo Co., Ltd., and Sumitomo Chemical Co., Ltd. “Esporex TPE Series”, “Engage” manufactured by Dow Chemical Japan Co., Ltd., “Prime TPO” manufactured by Prime Polymer Co., Ltd., “Miralastomer” manufactured by Mitsui Chemicals, Inc. “Zeras”, “Thermolan” manufactured by Mitsubishi Chemical Corporation, RIKEN TECHNOS “Multi-use rheo-stromer”, “Oreflex”, “Trinity FR”, etc. manufactured by Co., Ltd. can be mentioned.

When the styrenic elastomer is a block copolymer, the foamed molded article has a high expansion ratio when the foamed molded article is produced using a masterbatch, which is preferable.
When the styrene elastomer is a block copolymer, examples of the hard segment include a segment made of polystyrene. Examples of the soft segment include segments made of polybutadiene, hydrogenated polybutadiene, polyisoprene, and hydrogenated polyisoprene. Examples of such styrene-based elastomers include styrene-butadiene-styrene (SBS) copolymers, styrene-isoprene-styrene (SIS) copolymers, styrene-ethylene-butylene-styrene (SEBS) copolymers, and styrene. Examples thereof include block copolymers such as an ethylene-propylene-styrene (SEPS) copolymer and a styrene-butadiene-butylene-styrene (SBBS) copolymer.

Examples of commercially available styrenic elastomers include “Toughbrene”, “Asablene”, “Toughtech” manufactured by Asahi Kasei Corporation, “Elastomer AR” manufactured by Aron Kasei Co., Ltd., “Septon” manufactured by Kuraray Co., Ltd., “Hibler”, JSR. “JSR TR”, “JSR SIS” manufactured by Showa Kasei Kogyo Co., Ltd. “Maxilon” manufactured by Showa Kasei Kogyo Co., Ltd. “Tribrene”, “Super Tribrene” manufactured by Shinko Kasei Co., Ltd. “Esporex SB Series” manufactured by Sumitomo Chemical Co., Ltd. “Rheostomer”, “Actimer”, “High-performance Alloy Actimer”, “Activimer G”, etc. manufactured by Riken Technos Co., Ltd. can be mentioned.
It is preferable that the ester-based elastomer is a block copolymer because the foamability of microspheres thermally expanded inside the foamed molded product is improved when a foamed molded product is produced using a masterbatch. In addition, when the ester-based elastomer is a polyether ester elastomer, flexibility is imparted, so that when the foam molded body is produced using a master batch, the dispersibility of the microspheres thermally expanded inside the foam molded body Is preferable for improving.

When the ester elastomer is a block copolymer, it is preferably a block copolymer composed of a hard segment made of polybutylene terephthalate and a soft segment made of poly (polyoxyethylene) terephthalate.
Here, the hard segment is a crystalline phase and contributes to high mechanical strength, heat distortion resistance, and good workability. On the other hand, the soft segment is an amorphous phase and contributes to flexibility, high impact absorption, and low temperature characteristics.
Here, the content of the soft segment which is poly (polyoxyethylene) terephthalate in the ester elastomer is not particularly limited, but is preferably 5 to 95% by weight, more preferably 10 to 90% by weight, and particularly preferably. Is 15 to 85% by weight. When the content of the soft segment is 5% by weight or less, the resulting ester elastomer may be hardened.
Examples of commercially available ester elastomers include “Primalloy” manufactured by Mitsubishi Chemical Corporation, “Perprene” manufactured by Toyobo Co., Ltd., “Hytrel” manufactured by Toray DuPont Co., Ltd., and the like.

[Masterbatch and manufacturing method thereof]
The masterbatch of the present invention includes the heat-expandable microspheres described above and an organic base component.
The weight ratio of the thermally expandable microspheres contained in the master batch is not particularly limited, but is preferably 20 to 70% by weight, more preferably, based on the total amount of the thermally expandable microspheres and the organic base material component. 30 to 65% by weight, particularly preferably 40 to 65% by weight. When the weight ratio of the heat-expandable microspheres is 20% by weight or less, the foamability of the master batch may be lowered. On the other hand, when the weight ratio of the thermally expandable microspheres exceeds 70% by weight, it may be difficult to produce a masterbatch.

The shape of the cross section when the master batch is cut along a plane perpendicular to its length direction is appropriately determined depending on the use of the master batch, and examples thereof include a circle, an ellipse, a polygon, a star, and a hollow circle. be able to.
The length of the master batch is also appropriately determined depending on its use and the like, but is preferably 1 to 100 mm, more preferably 1.5 to 80 mm, and particularly preferably 2 to 70 mm. When the length of the master batch is out of the range of 1 to 100 mm, the expansion ratio of the foam molded body produced using the master batch is unstable and the specific gravity varies due to poor dispersion of the thermally expandable microspheres. May occur and poor appearance may occur.

The major axis length of the cross section in a plane perpendicular to the length direction of the master batch is also appropriately determined depending on the application, but is preferably 0.03 to 5 mm, more preferably 0.05 to 4 mm, and particularly preferably 0. .1 to 3 mm. If the major axis length of the cross section is outside the range of 0.03 to 5 mm, the foaming ratio of the foamed molded product produced using the master batch is unstable due to poor dispersion of the thermally expandable microspheres, and the specific gravity Variation may occur and appearance defects may occur.
Although there is no limitation in particular about the density of a masterbatch, Preferably it is 0.60-1.5 g / cm < ³ >, More preferably, it is 0.65-1.3 g / cm < ³ >, Most preferably, it is 0.7-1.2 g. / Cm ³ . When the density of the master batch is outside the range of 0.60 to 1.5 g / cm ³ , a part of the thermally expandable microspheres in the master batch is already expanded or a part of the thermally expandable microspheres Is destroyed, the expansion ratio of the master batch may be reduced.

The expansion ratio of the master batch is not particularly limited, but is preferably 5 to 120 times, more preferably 10 to 100 times, and particularly preferably 15 to 75 times. When the expansion ratio of the master batch is less than 5 times, the expansion ratio of the foam molded article produced using the master batch may be low. When the expansion ratio exceeds 120 times, the foaming is performed up to the vicinity of the surface layer of the foamed molded product, which may cause poor appearance.
As a manufacturing method of a masterbatch, what is necessary is just the method of mixing a thermally expansible microsphere and an organic base material component, and the method of disperse | distributing these uniformly is preferable. As a manufacturing method of a masterbatch, the manufacturing method including the preliminary kneading | mixing process shown to the following (1) and the pelletizing process shown to the following (2) can be mentioned, for example.

(1) Preliminary kneading in which an organic base material component is melt-kneaded in advance with a kneader such as a roll, kneader, pressure kneader, Banbury mixer, etc., and thermally expandable microspheres are added therein to prepare a pre-kneaded product. Process.
(2) Next, the obtained pre-kneaded product is put into an extruder such as a single-screw extruder, a twin-screw extruder, or a multi-screw extruder, and the molten mixture is extruded at a desired thickness, and pelletized with a hot cut pelletizer. Pelletizing process.
Moreover, when a long masterbatch is required, it can manufacture by making a strand-like thing of desired thickness into a desired long length with an extrusion cutter from an extruder. At this time, the thickness of the strand can be adjusted by the diameter of the strand die of the extruder and the strand winding speed.

The masterbatch of the present invention may further contain a molding additive such as a stabilizer, a lubricant, a filler, and a dispersibility improver in addition to the organic base component and the thermally expandable microsphere.
Examples of the stabilizer include pentaerythrityl-tetrakis- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis- [3- (3-t-butyl). -5-methyl-4-hydroxyphenyl) propionate] and the like; phosphorus stabilizers such as tris (monononylphenyl) phosphite and tris (2,4-di-t-butylphenyl) phosphite; And sulfur stabilizers such as dilauroyl dipropionate. These stabilizers may be used individually by 1 type, and may use 2 or more types together.

The blending amount of the stabilizer is preferably 0.01 to 1.0 part by weight and more preferably 0.05 to 0.5 part by weight with respect to 100 parts by weight of the organic base component. When the blending amount of the stabilizer is less than 0.01 parts by weight, the blending effect of the stabilizer may not be obtained. On the other hand, when the compounding quantity of a stabilizer exceeds 1.0 weight part, the function of a stabilizer may be impaired.
Examples of the lubricant include sodium, calcium and magnesium salts of saturated or unsaturated fatty acids such as lauric acid, palmitic acid, oleic acid and stearic acid. These lubricants may be used individually by 1 type, and may use 2 or more types together.

The blending amount of the lubricant is preferably 0.1 to 2.0 parts by weight with respect to 100 parts by weight of the organic base component. If the blending amount of the lubricant is less than 0.1 parts by weight, the blending effect of the lubricant may not be exhibited. On the other hand, if the blending amount of the lubricant exceeds 2.0 parts by weight, the function of the lubricant may be impaired.
As the filler, those having various shapes such as a fibrous shape, a particulate shape, a powder shape, a plate shape, and a needle shape can be used. Examples of fillers include glass fibers (including those coated with metals), carbon fibers (including those coated with metals), potassium titanate, asbestos, silicon carbide, silicon nitride, ceramic fibers, metal fibers, and aramids. Fiber, barium sulfate, calcium sulfate, calcium silicate, calcium carbonate, magnesium carbonate, antimony trioxide, zinc oxide, titanium oxide, magnesium oxide, iron oxide, molybdenum disulfide, magnesium hydroxide, aluminum hydroxide, mica, talc, kaolin Pyrophyllite, bentonite, sericite, zeolite, wollastonite, alumina, clay, ferrite, graphite, gypsum, glass beads, glass balloon, quartz and the like. These fillers may be used individually by 1 type, and may use 2 or more types together. Among these fillers, talc, calcium carbonate, magnesium hydroxide and the like are preferable.

The blending amount of the filler is preferably 0.1 to 50 parts by weight, and more preferably 1 to 50 parts by weight with respect to 100 parts by weight of the organic base component. When the blending amount of the filler is less than 0.1 parts by weight, the blending effect of the filler may not be exhibited. On the other hand, when the compounding quantity of a filler exceeds 50 weight part, the function of a filler may be impaired.
Examples of the dispersibility improver include aliphatic hydrocarbons, paraffinic process oils such as paraffin oil, aromatic process oils such as aroma oil, liquid paraffin, petrotam, gilsonite, and petroleum asphalt.
The blending amount of the dispersibility improver is not particularly limited, but is preferably 25% by weight or less, more preferably 20% by weight or less, particularly preferably based on the total amount of the heat-expandable microspheres and the organic base component. Is 15% by weight or less. When the blending amount of the dispersibility improver exceeds 25% by weight, the function of the dispersibility improver may be impaired.

[Foamed molded product and method for producing the same]
The foam molded article is obtained by molding a composition containing a masterbatch and a matrix component (hereinafter, this composition may be referred to as “molding composition”).
Although there is no limitation in particular as a matrix component, For example, polyvinyl chloride; polyvinylidene chloride; polyvinyl alcohol; ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, ethylene-methyl (meth) acrylate copolymer Ethylene copolymers such as ethylene-ethyl (meth) acrylate copolymer, ethylene-butyl (meth) acrylate copolymer; ionomers; low density polyethylene, high density polyethylene, polypropylene, polybutene, polyisobutylene, polystyrene, polyterpene Polyolefin resin such as styrene-acrylonitrile copolymer, styrene-copolymer such as styrene-butadiene-acrylonitrile copolymer, polyacetal, polymethyl methacrylate, cellulose acetate, polycarbonate Polyester resin such as polyethylene terephthalate and polybutylene terephthalate; polyamide resin such as nylon 6 and nylon 66; thermoplastic polyurethane; tetrafluoroethylene; ionomer such as ethylene ionomer, urethane ionomer, styrene ionomer, and fluorine ionomer Resin; Polyacetal; Thermoplastic resin such as polyphenylene sulfide; Thermoplastic elastomer such as urethane elastomer, styrene elastomer, olefin elastomer, amide elastomer, ester elastomer; polylactic acid (PLA), cellulose acetate, PBS, PHA, Examples thereof include bioplastics such as starch resin, and mixtures thereof.

Among the matrix components, like the organic base material component, the thermoplastic elastomer is preferable because the dispersibility of the microspheres thermally expanded in the foam molded body is improved when producing the foam molded body. The description of the thermoplastic elastomer is the same when the thermoplastic elastomer is used as a matrix component.
The weight ratio of the thermally expandable microspheres contained in the molding composition is not particularly limited, but is preferably 0.01 to 60% by weight, more preferably 0.1 to 50% with respect to the molding composition. % By weight, particularly preferably 0.5 to 20% by weight, most preferably 1 to 10% by weight. If the weight ratio of the heat-expandable microspheres is less than 0.01% by weight, the lightening effect may be reduced. On the other hand, when the weight ratio of the heat-expandable microspheres is more than 60% by weight, the weight reduction described later may become saturated, which is not preferable.

The weight ratio of the matrix component contained in the molding composition is not particularly limited, but is preferably 40 to 99.99% by weight, more preferably 50 to 99.9% by weight, based on the molding composition. Particularly preferred is 80 to 99.5% by weight, and most preferred is 90 to 99% by weight. When the weight ratio of the matrix component is less than 40% by weight, the below-described weight reduction may become saturated, which is not preferable. On the other hand, if the weight ratio of the matrix component is more than 99.99% by weight, the lightening effect may be reduced.
The molding composition may further contain the above-described additives such as a stabilizer, a lubricant, a filler, a dispersibility improver, and the like, together with a matrix component and a masterbatch containing thermally expandable microspheres.

The blending amount of the stabilizer is preferably 0.01 to 1.0 part by weight and more preferably 0.05 to 0.5 part by weight with respect to 100 parts by weight of the matrix component. When the blending amount of the stabilizer is less than 0.01 parts by weight, the blending effect of the stabilizer may not be obtained. On the other hand, when the compounding quantity of a stabilizer exceeds 1.0 weight part, the function as an obtained foaming molding may be impaired.
The blending amount of the lubricant is preferably 0.1 to 2.0 parts by weight with respect to 100 parts by weight of the matrix component. If the blending amount of the lubricant is less than 0.1 parts by weight, the blending effect of the lubricant may not be exhibited. On the other hand, when the blending amount of the lubricant is less than 2.0 parts by weight, the function as the obtained foamed molded product may be impaired.

The blending amount of the filler is preferably 0.1 to 50 parts by weight, and more preferably 1 to 50 parts by weight with respect to 100 parts by weight of the matrix component. When the blending amount of the filler is less than 0.1 parts by weight, the blending effect of the filler may not be exhibited. On the other hand, when the compounding quantity of a filler exceeds 50 weight part, the function as an obtained foaming molding may be impaired.
As a molding method of the molding composition, various molding methods such as injection molding, extrusion molding, blow molding, calendar molding, press molding, vacuum molding and the like are used. At the time of molding, the thermally expandable microspheres are thermally expanded to obtain hollow particles, so that the foamed molded product contains hollow particles.

The foaming ratio (foaming ratio of the foamed molded product) when the foamed molded product is obtained by molding of the molding composition is not particularly limited, but is preferably 1.1 times or more, more preferably 1.2 to 5 Times, particularly preferably 1.4 to 4 times, and most preferably 1.5 to 3 times. If the foaming ratio of the foamed molded product is less than 1.1 times, the weight reduction effect may not be obtained. On the other hand, when the foaming ratio of the foamed molded product is larger than 5 times, the weight reduction effect can be sufficiently obtained, but the strength may be greatly impaired.
The hollow particles contained in the foamed molded product are obtained by thermally expanding the thermally expandable microspheres described above. Although there is no limitation in particular about the average particle diameter of a hollow particle, Preferably it is 1-1000 micrometers, More preferably, it is 5-800 micrometers, Most preferably, it is 10-500 micrometers. Further, the coefficient of variation CV of the particle size distribution of the hollow particles is not particularly limited, but is preferably 30% or less, more preferably 27% or less, and particularly preferably 25% or less.

The weight ratio of the hollow particles contained in the foamed molded product is not particularly limited, but is preferably 0.01 to 60% by weight, more preferably 0.1 to 50% by weight, particularly preferably based on the foamed molded product. Is 0.5 to 20% by weight, most preferably 1 to 10% by weight. When the weight ratio of the hollow particles is less than 0.01% by weight, the weight reduction effect may be reduced. On the other hand, when the weight ratio of the hollow particles is more than 60% by weight, the below-described weight reduction may become saturated, which is not preferable.
The weight ratio of the matrix component contained in the foamed molded product is not particularly limited, but is preferably 40 to 99.99% by weight, more preferably 50 to 99.9% by weight, particularly preferably based on the foamed molded product. Is 80 to 99.5% by weight, most preferably 90 to 99% by weight. When the weight ratio of the matrix component is less than 40% by weight, the below-described weight reduction may become saturated, which is not preferable. On the other hand, if the weight ratio of the matrix component is more than 99.99% by weight, the lightening effect may be reduced.

The master batch of the present invention is easily deformed by the strong shearing force of the cylinder at the raw material supply port of the molding machine.
And when manufacturing a foaming molding (for example, a film, a sheet | seat, an injection molding etc.), it deform | transforms easily with the strong shearing force of the cylinder in a raw material supply port by using this masterbatch. As a result, the obtained foamed molded article has no uneven specific gravity, and the foaming ratio is uniform and stable throughout. And an external appearance also becomes favorable for a foaming molding.

Examples of the present invention will be specifically described below. The present invention is not limited to these examples. Examples 1-4, 6, 8, and 9 are used as reference examples. In the following Examples and Comparative Examples, “%” means “% by weight” and “parts” means “parts by weight” unless otherwise specified.
Prior to the examples, production examples of various thermally expandable microspheres are shown. Hereinafter, the raw material microspheres and the thermally expandable microspheres may be referred to as “microspheres” for simplicity.

[Measurement of average particle size and particle size distribution]
A laser diffraction particle size distribution analyzer (HEROS & RODOS manufactured by SYMPATEC) was used. The dispersion pressure of the dry dispersion unit was 5.0 bar and the degree of vacuum was 5.0 mbar, measured by a dry measurement method, and the D50 value was taken as the average particle size.

[Measurement of expansion start temperature (Ts) and maximum expansion temperature (Tmax)]
As a measuring device, DMA (DMA Q800 type, manufactured by TA instruments) was used. Place 0.5 mg of microspheres in an aluminum cup with a diameter of 6.0 mm (inner diameter 5.65 mm) and a depth of 4.8 mm, and place an aluminum lid (diameter 5.6 mm, thickness 0.1 mm) on top of the microsphere layer. Samples were prepared. The sample height was measured in a state where a force of 0.01 N was applied to the sample with a pressurizer from above. In a state where a force of 0.01 N was applied by the pressurizer, heating was performed from 20 ° C. to 350 ° C. at a rate of temperature increase of 10 ° C./min, and the displacement of the pressurizer in the vertical direction was measured. The displacement start temperature in the positive direction was defined as the expansion start temperature (Ts), and the temperature when the maximum displacement was indicated was defined as the maximum expansion temperature (Tmax).

[Production Example 1]
(Polymerization process)
To 600 g of ion-exchanged water, 150 g of sodium chloride, 50 g of colloidal silica which is 20% by weight of silica active ingredient, 1.0 g of polyvinylpyrrolidone and 0.5 g of ethylenediaminetetraacetic acid / 4Na salt were added, and then the pH of the resulting mixture was adjusted. 3 to prepare an aqueous dispersion medium.
Apart from this, 5 g of acrylonitrile, 115 g of methacrylonitrile, 180 g of methacrylic acid, 1.0 g of 1,9-nonanediol diacrylate, 50 g of isooctane, 30 g of isohexadecane, and di- (2-ethylhexyl) per with 70% active ingredient An oily mixture was prepared by mixing 8 g of the oxydicarbonate-containing liquid.

An aqueous dispersion medium and an oily mixture were mixed, and the obtained mixed liquid was dispersed with a homomixer (TK machine manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare a suspension. The suspension was transferred to a pressure reactor having a capacity of 1.5 liters, and purged with nitrogen. Then, the initial reaction pressure was 0.5 MPa, and polymerization was performed at a polymerization temperature of 60 ° C. for 20 hours while stirring at 80 rpm.
(Surface treatment process)
20 g of a diisopropoxy titanium bis (triethanolaminate) -containing liquid containing 80% of the active ingredient as a metal-containing organic compound was added to the polymerization liquid obtained after the polymerization while stirring at room temperature. The obtained dispersion mixture was transferred to a pressure reactor (capacity: 1.5 liters), purged with nitrogen, brought to a treatment initial pressure of 0.5 MPa, and treated at 80 ° C. for 5 hours while stirring at 80 rpm. The obtained treated product was filtered and dried to obtain thermally expandable microspheres. The physical properties are shown in Table 1.

[Production Examples 2 to 7]
The various components and amounts used in the polymerization step of Production Example 1 were changed to those shown in Table 1, and the heat-expandable microspheres were the same as Production Example 1 except that the surface treatment step of Production Example 1 was not performed. Respectively. Table 1 shows the physical properties of the obtained microspheres.
The thermally expandable microspheres obtained in Production Examples 1 to 7 are referred to as microspheres (1) to (7), respectively.

In Table 1, the abbreviations shown in Table 2 are used.

[Example 1]
(Master Badge)
Ester elastomer as an organic base material component (Hytorel manufactured by Toray DuPont, soft segment content 80% by weight, A hardness 77, flexural modulus 23.5 MPa, melting point 160 ° C., using a 10 L capacity kneader. 3.0 kg of specific gravity 1.07 g / cm ³ ) When the temperature reaches 165 ° C., 2.0 kg of the heat-expandable microspheres obtained in Production Example 1 are blended and mixed uniformly to prepare A mixture was obtained. The obtained preliminary mixture was supplied to a twin screw extruder having a cylinder diameter of 40 mm and extruded at a kneading temperature of 165 ° C. to obtain a master batch having a heat-expandable microsphere weight ratio of 40% and a specific gravity of 1.02 g / cm ^3. It was.
The ester elastomer used above was a block copolymer and was a polyether ester elastomer. The ester elastomer was composed of a hard segment made of polybutylene terephthalate and a soft segment made of poly (polyoxyethylene) terephthalate.

(Foamed molded product)
Next, set the temperature of the extrusion molding machine and the T die to 290 ° C using a lab plast mill (a twin-screw extruder ME-25 manufactured by Toyo Seiki Co., Ltd.) and a T die (lip width 150 mm, thickness 2 mm). The screw speed was set to 40 rpm. As the matrix component of the foam molded article, the ester elastomer used as the organic base material component was prepared. 5% of the master batch obtained above was added to the polyester-based elastomer, and the dry blended mixture was introduced from a raw hopper of a Laboplast mill. cm ³ ) was obtained.
The resulting foamed molded product was evaluated for the stability of the expansion ratio as shown below. As a result, the specific gravity was uniform, the expansion ratio was uniform and stable throughout, and the appearance was good. These results are shown in Table 3.

[Stability evaluation of foaming ratio of foamed molded product]
The specific gravity of the foamed molded product (width 150 mm × length 900 mm) was cut at intervals of 300 mm, the specific gravity of three test pieces was measured, and the stability of the expansion ratio was evaluated based on the following evaluation criteria. . The expansion ratio of the foamed molded product was calculated by calculating (specific gravity of the matrix component contained in the foamed molded product) / (specific gravity of the foamed molded product).
○: The specific gravity difference of each test piece was within 0.05 g / cm ³ .
X: The specific gravity difference of each test piece was more than 0.05 g / cm ³ .

[Examples 2 to 9, Comparative Examples 1 to 3]
The organic base material component used in Example 1, the amount of thermally expandable microspheres, the processing conditions, the matrix component, the master batch addition amount, the molding temperature, etc. were changed to those shown in Tables 3 and 4, respectively. In the same manner as in Example 1, a master batch and a foamed molded article were obtained. The respective physical properties are shown in Tables 3 and 4.
The ester elastomer used in Examples 2, 8 and 9 was a block copolymer and was a polyether ester elastomer. Further, these ester elastomers were composed of a hard segment made of polybutylene terephthalate and a soft segment made of poly (polyoxyethylene) terephthalate.

The styrenic elastomer used in Example 3 was a type of styrene-butadiene-butylene-styrene (SBBS) copolymer of a thermoplastic elastomer.
The styrenic elastomer used in Example 4 was a styrene-butadiene-styrene (SBS) copolymer of a thermoplastic elastomer.

The olefin elastomer used in Example 5 is a kind of thermoplastic elastomer, and was composed of a hard segment made of polypropylene and a soft segment made of an ethylene-propylene-diene copolymer (EPDM).
The olefin elastomer used in Example 6 is a kind of thermoplastic elastomer, and is composed of a hard segment made of polypropylene and a soft segment partially crosslinked with an ethylene-propylene-diene copolymer (EPDM). It was.

The styrene elastomer used in Example 7 was a styrene-ethylene-propylene-styrene (SEPS) copolymer of a thermoplastic elastomer.
In Comparative Examples 1 to 3, the A base hardness of the organic base component exceeded 90.

Claims (7)

When configured thermally expandable microspheres and a foaming agent to evaporate by heating the thermoplastic and the outer shell made of a resin is contained in it and, thermoplastic elastomer and the including A hardness of 15 to 54,
Master Badge. The masterbatch according to claim 1, wherein the weight ratio of the thermally expandable microspheres is 20 to 70% by weight of the total amount of the thermally expandable microspheres and the thermoplastic elastomer .   The masterbatch according to claim 1 or 2, wherein the thermoplastic resin is obtained by polymerizing a polymerizable component containing a nitrile monomer.   The masterbatch according to claim 3, wherein the polymerizable component further contains a carboxyl group-containing monomer.   The masterbatch according to any one of claims 1 to 4, wherein the thermally expandable microsphere is surface-treated with an organic compound containing a metal belonging to Groups 3 to 12 of the periodic table.   The masterbatch in any one of Claims 1-5 whose expansion start temperature of the said thermally expansible microsphere is 100 degreeC or more. A foam molded article formed by molding a composition comprising the masterbatch according to any one of claims 1 to 6 and a matrix component.