JP7189768B2 - Resin composition and its use - Google Patents

Description

The present invention relates to a resin composition and its use.

Hollow particles such as plastic balloons are used as lightweight fillers for clays, paints, adhesives and the like. The purpose of blending these weight-reducing fillers is to reduce costs by saving environmental measures and resin components (Patent Document 1).
Such a plastic balloon is obtained by expanding thermally expandable microspheres having a structure in which a thermoplastic resin is used as an outer shell and a foaming agent is enclosed therein. The heat-expandable microspheres are generally called heat-expandable microcapsules. Vinylidene chloride-based copolymers, acrylonitrile-based copolymers, acrylic acid ester-based copolymers, and the like are usually used as thermoplastic resins. Hydrocarbons such as isobutane and isopentane are mainly used as foaming agents (see Patent Document 2).

However, these weight-reducing fillers do not sufficiently improve resistance to external pressure loads during mixing and filling in the resin composition production process.
Further, Patent Document 3 describes hollow fine particles obtained by heating and expanding thermally expandable microcapsules having an outer shell formed of a polymer obtained from a specific monomer and a cross-linking agent and having an expansion ratio of 20 to 100 times. It is described to be incorporated into lightweight cement products. However, even with these hollow fine particles, the resistance of the hollow particles to external pressure is not sufficiently improved.

WO 97/05201 U.S. Pat. No. 3,615,972 Japanese Patent Application Laid-Open No. 2004-131361

An object of the present invention is to provide a resin composition that enables production of a resin molded product excellent in production stability and weight reduction efficiency, and its use.

As a result of intensive studies by the present inventors, it was found that a resin composition containing hollow particles (A) having a specific volume ratio of air content has improved resistance to external pressure load, and the mixing and filling steps The present inventors have found that the crushing of the molded article can be suppressed, and as a result, it is possible to produce a resin molded article excellent in production stability and weight reduction efficiency, and arrived at the present invention.

That is, the resin composition of the present invention contains hollow particles (A) and an organic base resin (B), and the hollow particles (A) are composed of an outer shell made of a thermoplastic resin, and the hollow particles (A) encapsulated therein and heated. and a blowing agent that is vaporized by heating. When the volume is 100%, it is 30% or more.

It is preferable that the resin composition of the present invention further satisfies at least one selected from the following 1) to 2).
1) The volume-based cumulative 50% particle diameter (D50) of the hollow particles (A) is 1 to 300 μm.
2) It is a coating composition, an adhesive composition or a polymer clay.

The molded article of the present invention is obtained by molding the above resin composition.
The method for producing the resin composition of the present invention comprises a step (1) of obtaining thermally expandable microspheres composed of an outer shell made of a thermoplastic resin and a foaming agent encapsulated therein and vaporized by heating; a step (2) of thermally expanding the heat-expandable microspheres to obtain hollow particles (a); and a step (4) of mixing the obtained hollow particles (A) with the organic base resin (B), wherein the volume ratio of the air content in the hollow particles (A) ( P) is 30% or more when the volume of the entire hollow particles (A) is taken as 100%.

By using the resin composition of the present invention or the resin composition obtained by the production method of the present invention, it is possible to produce a resin molded article excellent in production stability and weight reduction efficiency.

It is an example of a schematic diagram of a hollow particle (A). FIG. 2 is a schematic diagram of an expansion process section of a manufacturing apparatus for manufacturing hollow particles by a dry thermal expansion method.

The resin composition of the present invention contains hollow particles (A) and an organic base resin (B). A detailed description will be given below.

[Hollow particles (A)]
Hollow particles (A) are an essential component of the resin composition of the present invention. The hollow particles (A) are expanded bodies of thermally expandable microspheres composed of an outer shell made of a thermoplastic resin and a foaming agent contained therein and vaporized by heating, and the hollow particles (A) The volume ratio (P) of the amount of air contained in the hollow particles (A) is 30% or more when the volume of the entire hollow particles (A) is taken as 100%. The hollow particles (A) will be described by taking the production method thereof as an example.

The method for producing the hollow particles (A) includes a step (1) of producing thermally expandable microspheres composed of an outer shell made of a thermoplastic resin and a foaming agent contained therein and vaporized by heating. a step (2) of heating and expanding the heat-expandable microspheres obtained in step (1) to obtain hollow particles (a); A production method including the step (3) of obtaining hollow particles (A) by aging in the range of . Incidentally, the step (1) may be called a polymerization step, the step (2) may be called an expansion step, and the step (3) may be called an aging step.

(Polymerization process)
The polymerization step refers to the step (1) of producing thermally expandable microspheres composed of an outer shell made of a thermoplastic resin and a foaming agent contained therein and vaporized by heating. The polymerization step includes a step of dispersing an oily mixture containing a polymerizable component and a foaming agent in an aqueous dispersion medium and polymerizing the polymerizable component.
The blowing agent is not particularly limited as long as it is a substance that vaporizes by heating. Examples include propane, (iso)butane, (iso)pentane, (iso)hexane, (iso)heptane, (iso)octane, ( Hydrocarbons having 3 to 13 carbon atoms such as iso)nonane, (iso)decane, (iso)undecane, (iso)dodecane, and (iso)tridecane; 20 or less hydrocarbons, etc. can be mentioned. These foaming agents may be used singly or in combination of two or more.
The foaming agent is preferably a hydrocarbon having a boiling point of less than 60°C. If a hydrocarbon with a boiling point exceeding 60° C. is used, the hollow particles (A) may be crushed during mixing of the resin composition, and a sufficient weight reduction rate may not be obtained.

The polymerizable component is a component which, when polymerized, becomes a thermoplastic resin that forms the outer shell of the thermally expandable microspheres. The polymerizable component is a component that essentially comprises a monomer component and may contain a cross-linking agent.
The monomer component generally includes a component called a (radical) polymerizable monomer having one polymerizable double bond.

A thermoplastic resin obtained by polymerizing a polymerizable component in which the monomer component is a nitrile-based monomer, the polymerizable component contains a nitrile-based monomer, and the hollow particles contain a nitrile-based monomer Such a structure is preferable because the retention of the blowing agent contained in the hollow particles (A) and (a) is excellent.
Examples of nitrile-based monomers include acrylonitrile (AN), methacrylonitrile (MAN), fumaronitrile, and the like.

The weight ratio of the nitrile-based monomer in the polymerizable component is not particularly limited, but is preferably 20% by weight or more, more preferably 40% by weight or more, and particularly preferably 60% by weight or more. The upper limit of the weight ratio of the nitrile monomer is preferably 100% by weight. If the weight ratio of the nitrile-based monomer is less than 20% by weight, the retention of the foaming agent contained in the hollow particles (A) and (a) is poor, and the foaming agent may be gradually released.
When acrylonitrile (AN) and methacrylonitrile (MAN) are essential nitrile-based monomers, thermally expandable microcapsules and hollow particles (A) and (a), which are raw materials for hollow particles (A) and (a), It is preferable because it is excellent in retention of the included foaming agent.

The polymerizable component may contain a monomer other than the nitrile-based monomer as a monomer component.
Monomers other than nitrile-based monomers are not particularly limited, but include, for example, vinyl halide-based monomers such as vinyl chloride; vinylidene halide-based monomers such as vinylidene chloride; vinyl acetate, propionic acid; vinyl ester-based monomers such as vinyl and vinyl butyrate; carboxyl group-containing monomers such as (meth)acrylic acid, ethacrylic acid, crotonic acid and cinnamic acid; carboxylic anhydrides such as maleic acid, itaconic acid and fumaric acid System monomer; 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) acrylic acid ester monomers; acrylamide, substituted acrylamide, methacrylamide, (meth)acrylamide-based monomers such as substituted methacrylamide; maleimide-based monomers such as N-phenylmaleimide and N-cyclohexylmaleimide; styrene-based monomers such as styrene and α-methylstyrene; ethylene, propylene, and 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-vinylcarbazole, N-vinyl Examples include N-vinyl monomers such as pyrrolidone; vinylnaphthalene salts and the like. (Meth)acryl means acryl or methacryl.

Polymerizable components include (meth)acrylic acid ester monomers, carboxyl group-containing monomers, styrene monomers, vinyl ester monomers, acrylamide monomers, maleimide monomers and vinylidene chloride It is preferable to further include at least one selected from.
When the polymerizable component contains a nitrile-based monomer and a (meth)acrylic acid ester-based monomer, it is preferable from the viewpoint of retention of the blowing agent in the thermally expandable microspheres and heat resistance.

The polymerizable component may contain a polymerizable monomer (crosslinking agent) having two or more polymerizable double bonds, in addition to the above monomer components. Polymerization using a cross-linking agent suppresses a decrease in the retention rate of the encapsulated foaming agent during thermal expansion over time, and enables effective thermal expansion.

The cross-linking agent is not particularly limited, but examples include aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; ) acrylate, triethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, PEG# 200 di(meth)acrylate, PEG#400 di(meth)acrylate, PEG#600 di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, trimethylolpropane tri (Meth)acrylates, EO-modified trimethylolpropane tri(meth)acrylate, glycerin di(meth)acrylate, dimethylol-tricyclodecane di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate Acrylate, dipentaerythritol hexa(meth)acrylate and the like can be mentioned. These cross-linking agents may be used singly or in combination of two or more.

The amount of the cross-linking agent is not particularly limited, but is preferably 0.01 to 5 parts by weight, more preferably 0.1 to 1 part by weight, particularly preferably 0.1 to 1 part by weight, based on 100 parts by weight of the monomer component. 3 to 0.9 parts by weight, most preferably 0.5 to 0.8 parts by weight.
Polymerization of the polymerizable component is preferably carried out using a polymerization initiator, and an oil-soluble polymerization initiator is preferred.

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-exchanged water for dispersing the oily mixture, and may further contain an alcohol such as methanol, ethanol or propanol, or a hydrophilic organic solvent such as acetone. . Hydrophilicity in the present invention means being arbitrarily miscible with water. The amount of the aqueous dispersion medium to be used is not particularly limited, but it is preferable to use 100 to 1000 parts by weight of the aqueous dispersion medium with respect to 100 parts by weight of the polymerizable component.

The aqueous dispersion medium may further contain an electrolyte. Examples of electrolytes include sodium chloride, magnesium chloride, calcium chloride, sodium sulfate, magnesium sulfate, ammonium sulfate, sodium carbonate, and the like. These electrolytes may be used singly or in combination of two or more. The content of the electrolyte is not particularly limited, but is preferably 0.1 to 50 parts by weight per 100 parts by weight of the aqueous dispersion medium.

The 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 heteroatom are bonded to the same carbon atom. , potassium dichromate, alkali metal nitrites, metal (III) halides, boric acid, water-soluble ascorbic acids, water-soluble polyphenols, water-soluble B vitamins and water-soluble phosphonic acids (salts) It may contain at least one water-soluble compound. The term "water-soluble" as used in the present invention means a state in which 1 g or more is dissolved in 100 g of water.

The amount of the water-soluble compound contained in the aqueous dispersion medium is not particularly limited. 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 effects of the water-soluble compound may not be sufficiently obtained. On the other hand, if the amount of the water-soluble compound is too large, the rate of polymerization may decrease, or the residual amount of the polymerizable component, which is the starting material, may increase.

The aqueous dispersion medium may contain a dispersion stabilizer and a dispersion stabilizing aid in addition to the electrolyte and water-soluble compound.
The dispersion stabilizer is not particularly limited, but examples include colloidal silica, colloidal calcium carbonate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, ferric hydroxide, calcium sulfate, barium sulfate, calcium oxalate, and metasilicic acid. Phosphates such as calcium, calcium carbonate, barium carbonate, magnesium carbonate, calcium phosphate, magnesium phosphate, aluminum phosphate and zinc phosphate; pyrophosphates such as calcium pyrophosphate, aluminum pyrophosphate and zinc pyrophosphate; Dispersion stabilizers for water-soluble inorganic compounds can be mentioned. These dispersion stabilizers may be used alone or in combination of two or more.
The content of the dispersion stabilizer is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the polymerizable component.

The dispersion stabilizing aid is not particularly limited. Active agents may be mentioned. These dispersion stabilizing aids may be used singly 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 during polymerization is appropriately determined according to the types of water-soluble compound, dispersion stabilizer, and dispersion stabilizing aid.

Methods for emulsifying and dispersing the oily mixture include, for example, a method of stirring with a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) and a static dispersing device such as a static mixer (manufactured by Noritake Engineering Co., Ltd.). general dispersing methods such as a method using , a membrane emulsification method, and an ultrasonic dispersion method.
Suspension polymerization is then initiated by heating a dispersion in which the oily mixture is dispersed as spherical oil droplets in an aqueous dispersion medium. It is preferable to stir the dispersion during the polymerization reaction, and the stirring may be carried out gently enough to prevent floating of the monomers and sedimentation of the heat-expandable microspheres after polymerization.
The polymerization temperature is freely set according to the type of polymerization initiator, but is preferably 30 to 100°C, more preferably 40 to 90°C, particularly preferably 45 to 80°C, most preferably 50 to 75°C. controlled. The time for which the reaction temperature is maintained is preferably about 0.1 to 20 hours. The initial pressure of polymerization is not particularly limited, but is in the range of 0 to 5.0 MPa, more preferably 0.1 to 3.0 MPa in terms of gauge pressure.

(Expansion process)
The expansion step refers to step (2) in which the heat-expandable microspheres obtained in step (1) are thermally expanded to obtain hollow particles (a). The expansion step is not particularly limited as long as it is a step of heating and expanding the heat-expandable microspheres, but either a dry heat expansion method or a wet heat expansion method may be used.
Examples of the dry thermal expansion method include the method described in JP-A-2006-213930, particularly the internal injection method. Another dry thermal expansion method is the method described in Japanese Patent Application Laid-Open No. 2006-96963. As the wet thermal expansion method, there is a method described in JP-A-62-201231.
The temperature for heating and expanding the heat-expandable microspheres is preferably 60 to 350°C.

The outer shell of the hollow particles (a) is made of a thermoplastic resin. Hollow particles are composed of an outer shell and a hollow portion surrounded by it. A hollow particle has a hollow portion corresponding to a large cavity inside. The hollow portion is in contact with the inner surface of the shell. The hollow part is basically filled with gas and may be in a liquefied state. Generally, it is preferable that the hollow part is one large hollow part, but there may be a plurality of hollow parts in the hollow particle.

The hollow particles (a) refer to expanded bodies of the above heat-expandable microspheres that have not been aged or that have been insufficiently aged. Aging will be explained in detail in the aging process. The hollow particles (a) can be obtained by heating and expanding the above thermally expandable microspheres and then cooling to room temperature. Immediately after the cooling, an air concentration gradient occurs inside and outside the hollow portion of the hollow particle, and the air content inside the hollow portion of the hollow particle is low, resulting in a negative pressure state. Therefore, it has a distorted shape and is vulnerable to external pressure. When such hollow particles (a) are used as a lightweight filler for a resin composition, the hollow particles (a) are easily deformed, crushed, or ruptured, resulting in leakage of the foaming agent. The weight reduction efficiency of the article and its molded body is lowered.
The volume ratio (P) of the amount of air contained in the hollow particles (a) is less than 30% when the volume of the entire hollow particles is taken as 100%. A method for measuring the volume fraction (P) will be described in the aging step.

(Aging process)
The aging step refers to the step (3) of aging the hollow particles (a) obtained in step (2) at a temperature in the range of -10 to 60°C to obtain hollow particles (A). The aging period is described below. Aging generally refers to the storage of a substance under suitable conditions for a period of time in order to obtain the desired properties of the substance. As described above, in the hollow particles (a) obtained in step (2), the air concentration inside the hollow portion is lower than that outside, and the hollow portion of the hollow particle is in a negative pressure state. Therefore, it has a distorted shape and is vulnerable to external pressure. Aging in the present invention means that air from the atmosphere is gradually introduced into the hollow portion, thereby eliminating the air concentration gradient between the inside and outside of the hollow portion, adjusting the balance between the internal and external pressure of the particles, and improving the resistance to external pressure. It means to let Specifically, it refers to storing the hollow particles (a) obtained in step (2) at a temperature in the range of −10 to 60° C. (hereinafter referred to as the aging temperature) for a certain period of time.

Whether or not the hollow part of the hollow particles is in a negative pressure state (whether or not the hollow particles have been aged) can be confirmed, for example, by the following method.
As one method, the degree of aging can be confirmed by calculating the amount of air taken into the inside of the hollow particles. For example, it is possible to store the hollow particles in a closed container while containing air, and calculate the amount of air taken into the inside of the hollow particles from the change in the volume of the closed container. When the volume of the entire container decreases, it means that the air in the container is trapped inside the hollow particles. Depending on the aging conditions, the sealed container may expand.
Another method is to measure the amount of air or oxygen contained in the hollow particles.

The aging temperature of the hollow particles (a) is in the range of -10 to 80°C, preferably -10 to 60°C, more preferably -5 to 50°C, still more preferably 0 to 40°C, particularly preferably 5°C. ~35°C, most preferably 10-30°C. If the aging temperature is less than -10°C, the restoration of the hollow particles is insufficient, and the hollow particles may be deformed, crushed, or ruptured due to external factors, resulting in leakage of the blowing agent. On the other hand, if the aging temperature is higher than 80° C., the blowing agent is slowly released, resulting in deformation or crushing due to external factors.

In the aging period of the hollow particles (a), the volume ratio (P) of the amount of air contained in the hollow particles (a) is 30% or more when the volume of the entire hollow particles (a) is 100% (that is, , is not particularly limited as long as it is a period during which the hollow particles (A) are obtained. The aging period can be determined according to the aging temperature (T) (°C). When aging at the aging temperature (T) (°C), the aging period (Q) (hours) preferably satisfies the following formula (I).
Q≧62×e ^−0.03T (I)
If the aging period does not satisfy the above formula (I), the internal pressure and external pressure of the hollow particles are not balanced, and external factors cause deformation, crushing, or bursting, resulting in leakage of the blowing agent. The upper limit of the aging period is not particularly limited as long as the effect of aging is exhibited, but the period is about 8 weeks. After aging, the hollow particles (A) can be further stored for a period in which the quality can be maintained.

The hollow particles (a) obtained by the dry thermal expansion method are powder, and are aged in the powder state. In the case of hollow particles (A1) to which a fine particle filler is adhered, which will be described later, they are also aged in a powder state. On the other hand, the hollow particles (a) obtained by the wet thermal expansion method are a hollow particle composition containing water, and are aged in the state of the hollow particle composition containing water. The weight ratio of water in the hollow particle composition is not particularly limited, and is preferably 99% by weight or less, more preferably 84% by weight or less, particularly preferably 49% by weight or less, and most preferably 30% by weight or less. . If the aging is performed in a sealed state with too few voids other than the hollow particles, the aging may not proceed well even at a predetermined temperature for a predetermined time.

The outer shell of the hollow particles (A) is made of a thermoplastic resin. Hollow particles (A) are preferably composed of an outer shell and a hollow portion surrounded by it. The hollow particles (A) are (substantially) spherical and have a hollow portion corresponding to a large cavity inside. A soft tennis ball can be mentioned as an example of a familiar product that has the shape of hollow particles.
The hollow is (approximately) spherical and is in contact with the inner surface of the shell. The hollow part is basically filled with gas and may be in a liquefied state. Generally, it is preferable that the hollow part is one large hollow part, but there may be a plurality of hollow parts in the hollow particle.

The hollow particles (A) used in the resin composition of the present invention are the expanded bodies of the above-described heat-expandable microspheres, and the volume ratio (P) of the air content in the hollow particles (A) is A) When the total volume is taken as 100%, it means 30% or more. By using such hollow particles (A), the effect of the present application can be exhibited. If the volume ratio (P) is less than 30%, the hollow particles may be deformed, crushed, or ruptured due to external factors, resulting in leakage of the foaming agent. The volume fraction (P) is preferably 35 to 99%, more preferably 40 to 98%, still more preferably 45 to 95%, and particularly preferably 50 to 90%.
A method for measuring the volume ratio (P) of the air content in the hollow particles will be described in the examples below. The amount of air contained in the hollow particles can be quantified from the amount of gas collected and the oxygen concentration in the gas. In addition to the galvanic cell method, there are other methods for measuring oxygen concentration, such as the zirconia method and the magnetic method. If combustible gas is included, measurement error increases, which is not preferable.

The hollow particles (A) preferably have a volume ratio (Z) of the amount of air taken in relative to the hollow particles within a certain range from the viewpoint of exhibiting the effects of the present application more effectively. The volume ratio (Z) is defined as the volume (Y1) of the sealed container containing the hollow particles of volume (V) and air, and the volume of the container after standing under certain conditions (Y2). When used, it means the one shown by the following formula. A specific method for measuring the volume ratio (Z) of the amount of air taken in relative to the hollow particles is shown in the examples below.
Volume ratio of the amount of air taken in to the hollow particles (Z) = (Y1-Y2)/V
The volume ratio (Z) is preferably -0.05 ≤ (Z) ≤ 0.2, more preferably -0.05 ≤ (Z) ≤ 0.05, further preferably -0.02 ≤ (Z) ≦0.02.

The foaming agent retention rate of the hollow particles (A) is preferably 85% or more, more preferably 90% or more, particularly preferably 95% or more, and most preferably 97%. If the foaming agent retention rate is less than 85%, the mechanical strength of the hollow particles (A) is weak and the hollow particles (A) are likely to be crushed during the production of the resin composition, resulting in a lower effect as a lightweight filler. There is A method for measuring the foaming agent retention rate of the hollow particles (A) is shown in the following examples.
The hollow particles (A) may be used in the resin composition as a hollow particle composition containing water. The weight ratio of water in the hollow particle composition is not particularly limited, and is preferably 99% by weight or less, more preferably 84% by weight or less, particularly preferably 49% by weight or less, and most preferably 30% by weight or less. . If the weight ratio of water in the hollow particle composition is too high, it may not be uniformly dispersed when mixed with other components constituting the resin composition.

The volume-based cumulative 50% particle diameter (D50) of the hollow particles (A) is not particularly limited, but is preferably 1 to 300 μm, more preferably 2 to 200 μm, still more preferably 3 to 150 μm, and particularly preferably. is 5-130 μm, most preferably 7-120 μm. If the D50 is out of this range, the efficiency of weight reduction may deteriorate when used in a resin composition.

The true specific gravity of the hollow particles (A) is not particularly limited, but is preferably 0.01 to 0.5, more preferably 0.012 to 0.49, still more preferably 0.04 to 0.49, especially It is preferably 0.1 to 0.48, most preferably 0.31 to 0.47. If the true specific gravity is less than 0.01, the thickness of the outer shell of the hollow particles (A) is thin, resulting in a decrease in strength, and the hollow particles (A) are destroyed when the resin composition is mixed, resulting in a decrease in weight reduction efficiency. I have something to do. On the other hand, if the true specific gravity exceeds 0.5, the weight reduction effect corresponding to the blending amount is low, which is uneconomical.

Hollow particles (A) may further comprise a particulate filler adhered to the outer surface of their shell, as shown in FIG. Hereinafter, the hollow particles (A) to which the particulate filler is adhered are sometimes referred to as "hollow particles (A1)" for simplicity. The term "attachment" as used herein may simply refer to a state 6 in which the fine particle fillers (6 and 7) are adsorbed to the outer surface of the outer shell 5 of the hollow particle (A1) 4, and the outer shell near the outer surface It means that the constituent thermoplastic resin may be softened or melted by heating, and the fine particle filler may be embedded in the outer surface of the outer shell of the hollow particles (A1) to be in a fixed state 7. The particle shape of the particulate filler may be amorphous or spherical.
The true specific gravity of the hollow particles (A1) is not particularly limited, but is preferably 0.01 to 0.5, more preferably 0.03 to 0.4, still more preferably 0.05 to 0.35. , particularly preferably 0.07 to 0.3, most preferably 0.1 to 0.25. When the true specific gravity of the hollow particles (A1) is less than 0.01, the durability may be lowered. On the other hand, when the true specific gravity of the hollow particles (A1) is greater than 0.5, the effect of lowering the specific gravity is low, so when the hollow particles (A1) are used to prepare the resin composition, the addition amount becomes large. , can be uneconomical.

The ratio of the average particle size of the fine particle filler to the average particle size of the hollow particles (A1) (average particle size of the fine particle filler/average particle size of the hollow particles (A1)) is determined from the viewpoint of adhesion of the fine particle filler. It is preferably 1 or less, more preferably 0.8 or less, more preferably 0.6 or less, particularly preferably 0.4 or less, and most preferably 0.2.
Various materials can be used as the fine particle filler, and it may be either an inorganic material or an organic material. Examples of the shape of the fine particles include spherical, needle-like, plate-like and irregular shapes.

The average particle size of the fine particle filler is appropriately selected depending on the hollow particle body used, and is not particularly limited, but is preferably 0.001 to 30 μm, more preferably 0.005 to 25 μm, and particularly preferably 0.01 to 20 μm. is. Within this range, as will be described later, the mixing properties are good when producing the hollow particles (A1).
The average particle size of the fine particle filler referred to here is the particle size of the fine particle filler measured by a laser diffraction method. If the particle diameter of the fine particle filler is on the order of microns, it refers to the primary particles. Average particle size was calculated as a unit.

Examples of inorganic substances constituting fine particle fillers include limestone (heavy calcium carbonate), quartz, silica, walrusnite, gypsum, asbestos, apatite, magnetite, zeolite, clay (montmorillonite, saponite, hectorite, beidellite, Minerals such as stevensite, nontronite, vermiculite, halloysite, talc, mica, mica, etc.); manganese, cobalt, calcium, gold, silver, chromium, titanium, iron, platinum, copper, lead, nickel, etc.) and their alloys; zinc, aluminum oxide, chromium oxide, manganese oxide, molybdenum oxide, tungsten oxide, vanadium oxide, tin oxide, iron oxide (including magnetic iron oxide), indium oxide, etc.), metal hydroxides (aluminum hydroxide, gold hydroxide , magnesium hydroxide, etc.), metal sulfides (copper sulfide, sodium sulfide, lead sulfide, nickel sulfide, platinum sulfide, etc.), metal halides (calcium fluoride, tin fluoride, potassium fluoride, etc.), metal carbides (carbonized calcium, titanium carbide, iron carbide, sodium carbide, etc.), metal nitrides (aluminum nitride, chromium nitride, germanium nitride, cobalt nitride, etc.), metal carbonates (calcium carbonate (light calcium carbonate), calcium hydrogen carbonate, sodium hydrogen carbonate (sodium bicarbonate), iron carbonate, etc.), metal sulfates (aluminum sulfate, cobalt sulfate, sodium hydrogen sulfate, copper sulfate, nickel sulfate, barium sulfate, etc.), other metal salts (titanates (barium titanate, magnesium titanate, etc.) , potassium titanate, etc.), borates (aluminum borate, zinc borate, etc.), phosphates (calcium phosphate, sodium phosphate, magnesium phosphate, etc.), aluminates (yttrium aluminate, etc.), nitrates (sodium nitrate, nitric acid metal compounds such as iron, lead nitrate, etc.).

Inorganic substances constituting fine particle fillers include synthetic calcium carbonate, ferrite, zeolite, silver ion-supported zeolite, zirconia, alum, lead zirconate titanate, alumina fiber, cement, xonotlite, silicon oxide (silica, silicate, glass, glass fiber), silicon nitride, silicon carbide, silicon sulfide, carbon black, carbon nanotubes, graphite, activated carbon, bamboo charcoal, charcoal, fullerene, and the like.

Examples of organic substances constituting fine particle fillers include (meth)acrylic acid, itaconic acid, citraconic acid, maleic acid, fumaric acid, vinylbenzoic acid; their esters, amides, and nitriles; styrene, methylstyrene, Vinyl aromatics such as ethylstyrene and chlorostyrene, and divinyl compounds having two or more vinyl groups such as divinylbenzene and trimethylolpropane are used as monomers. Examples include organic resins obtained by polymerization by free polymerization, dispersion polymerization, suspension polymerization, mini-emulsion polymerization, and the like.
Organic substances constituting fine particle fillers include sodium carboxymethylcellulose, hydroxyethylcellulose, methylcellulose, ethylcellulose, nitrocellulose, hydroxypropylcellulose, sodium alginate, polyvinyl alcohol, polyvinylpyrrolidone, sodium polyacrylate, carboxyvinyl polymer, polyvinylmethyl ether, and polyamide. Resins, nylon resins, silicone resins, urethane resins, polyethylene resins, polypropylene resins, fluorine-based resins, and the like may also be used.

If the particulate filler is composed of organic matter, it should not soften. If softened, fusion may occur during production of hollow particles (A1) to which fine particles are further adhered, and problems such as deterioration of yield may occur. Although the softening temperature of the organic substance depends on the temperature at which the hollow particles (A1) are produced, it is preferably 80 to 300°C, more preferably 90 to 290°C, still more preferably 100 to 280°C. The softening temperature of the organic substance is also preferably at least 10°C higher than the process temperature.
The inorganic and organic substances that make up the fine particle filler may be treated with surface treatment agents such as silane coupling agents, paraffin wax, fatty acids, resin acids, urethane compounds, and fatty acid esters, or may be untreated.

The method for producing the hollow particles (A1) includes, for example, the step (1) of producing the heat-expandable microspheres, and the step of mixing the obtained heat-expandable microspheres and the particulate filler (simply referred to as the mixing step). ) and heating the mixture obtained in the mixing step to a temperature above the softening point of the thermoplastic resin to expand the thermally expandable microspheres (corresponding to step (2) above), and filling the fine particles A manufacturing method comprising the step of attaching an agent to the outer surface of the outer shell (adhering step), and the step (3) of aging the hollow particles (a) to which the fine particle filler is attached to obtain the hollow particles (A1). can be mentioned.

The mixing step is a step of mixing the thermally expandable microspheres and the particulate filler.
The weight ratio of the particulate filler and the thermally expandable microspheres (fine particulate filler/thermally expandable microspheres) in the mixing step is not particularly limited, but is preferably 90/10 to 60/40, more preferably 85. /15 to 65/35, particularly preferably 80/20 to 70/30. When the fine particle filler/thermally expandable microspheres (weight ratio) is more than 90/10, the true specific gravity of the hollow particles (A1) increases, and the effect of lowering the specific gravity may decrease. On the other hand, when the fine particle filler/thermally expandable microspheres (weight ratio) is less than 60/40, the true specific gravity of the hollow particles (A1) becomes low, and handling such as dusting may be deteriorated.

The device used for the mixing step is not particularly limited, and a device having a very simple mechanism such as a container and stirring blades can be used. Alternatively, a powder mixer capable of general shaking or stirring may be used. Examples of powder mixers include powder mixers capable of oscillating or stirring, such as ribbon type mixers and vertical screw type mixers. In recent years, by combining a stirring device, we have developed an efficient multifunctional powder mixer, Super Mixer (manufactured by Kawata Co., Ltd.), High Speed Mixer (manufactured by Fukae Co., Ltd.), New Gram Machine (Seishin Enterprise Co., Ltd.). ), SV mixer (manufactured by Kobelco Eco-Solutions Co., Ltd.), or the like may be used.
In the attaching step, the mixture containing the thermally expandable microspheres and the fine particle filler obtained in the mixing step is heated to a temperature above the softening point of the thermoplastic resin constituting the outer shell of the thermally expandable microspheres. It is a process. In the adhering step, the thermally expandable microspheres are expanded and the fine particle filler is adhered to the outer surface of the outer shell.

Heating may be performed using a general contact heat transfer type or direct heating type mixing drying apparatus. The function of the mixing-type drying device is not particularly limited, but it is preferable to have a temperature controllable ability to disperse and mix raw materials, and optionally a decompression device or a cooling device for speeding up drying. The device used for heating is not particularly limited.
Regarding the temperature conditions for heating, although it depends on the type of the thermally expandable microspheres, the optimum expansion temperature is preferable, preferably 60 to 250°C, more preferably 70 to 230°C, further preferably 80 to 220°C. Especially preferably 100 to 200°C, most preferably 120 to 180°C.

[Organic base resin (B)]
The resin composition of the present invention essentially contains an organic base resin (B). The organic base resin (B) is not particularly limited, and includes resins used for coating compositions, adhesive compositions, and resin clays. Examples thereof include acrylic resin, polyvinyl chloride resin (PVC), urethane resin, epoxy resin, polyvinyl alcohol, vinyl acetate resin, ethylene/vinyl acetate copolymer resin, and rubber. Among them, an acrylic resin is preferable from an environmental point of view.

Examples of acrylic resins include polymers of alkyl acrylate (methyl, ethyl, butyl, 2-ethylhexyl, etc. as alkyl) or alkyl methacrylate (methyl, ethyl, butyl, lauryl, stearyl, etc. as alkyl), or Examples include acrylic resins including copolymers with other acrylic monomers.

Polyvinyl chloride resins (PVC) include, for example, homopolymers of polyvinyl chloride, copolymers of vinyl chloride, vinyl acetate, and the like.

Examples of urethane-based resins include blocked urethane prepolymers and blocked polyisocyanate compounds.

The blocked urethane prepolymer can be produced, for example, according to the following procedure.
(1) First, a polyol and an excess polyisocyanate compound are reacted to obtain an NCO-terminated urethane prepolymer.
Examples of the polyol include polyoxyalkylene polyol (PPG), modified polyether polyol, polyether polyol containing polytetramethylene ether glycol; condensation polyester polyol, lactone polyester polyol, polyester polyol containing polycarbonate diol; polybutadiene polyol polyol; polyolefin polyol; polyether polyol, by polymerizing or graft-polymerizing acrylonitrile alone or a mixed monomer of acrylonitrile and at least one selected from the group of styrene, acrylamide, acrylic acid ester, methacrylic acid ester and vinyl acetate. and polymer polyols.

Examples of the polyisocyanate compounds include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, dodecamethylene diisocyanate, and 1,3-cyclo Pentane diisocyanate, 1,6-hexane diisocyanate (HDI), 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 4,4′-methylenebis(cyclohexyl isocyanate), methyl 2,4-cyclohexane diisocyanate, methyl 2,6 -cyclohexane diisocyanate, 1,4-bis(isocyanatomethyl)cyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenyldiisocyanate, 1,5-naphthalene diisocyanate , 4,4′-diphenylmethane diisocyanate (MDI), crude MDI, 2,4- or 2,6-tolylene diisocyanate (TDI), 4,4′-toluidine diisocyanate, dianidine diisocyanate, 4,4′-diphenyl ether diisocyanate , 1,3- or 1,4-xylylene diisocyanate, ω,ω'-diisocyanate-1,4-diethylbenzene, isophorone diisocyanate (IPDI) and the like. These may be used individually by 1 type, and may use 2 or more types together.
(2) Next, the NCO-terminated urethane prepolymer is reacted with a suitable blocking agent (usually 0.9 to 1.5 equivalents of blocking agent per mole of NCO of the former) to form free NCO.
is obtained by blocking the desired blocked urethane prepolymer (particularly, a polymer polyol in which at least a part of the above polyol contains the above polymer polyol is preferable).
Examples of the blocking agent include alcohols such as methanol, ethanol, propanol, butanol and isobutanol; phenols such as phenol, cresol, xylenol, p-nitrophenol and alkylphenol; methyl malonate, ethyl malonate and dimethyl malonate. , diethyl malonate, ethyl acetoacetate, methyl acetoacetate, active methylene compounds such as acetylacetone; acid amides such as acetamide, acrylamide, acetanilide; acid imides such as succinimide and maleimide; 2-ethylimidazole, 2- imidazoles such as ethyl-4-methylimidazole; lactams such as 2-pyrrolidone and ε-caprolactam; oximes of ketones or aldehydes such as acetoxime, methyl ethyl ketoxime, cyclohexanone oxime and acetaldoxime; etc. These may be used individually by 1 type, and may use 2 or more types together.

Specific examples of the blocked urethane prepolymers include those obtained by reacting polypropylene glycol with TDI and/or HDI as an excess polyisocyanate compound and then reacting with methyl ethyl ketoxime as a blocking agent.

The blocked polyisocyanate compound can be obtained by blocking the free NCO of the polyisocyanate compound exemplified in the production of the NCO-terminated urethane prepolymer described above with the blocking agent described above. Specific examples of the blocked isocyanate compound include those obtained by reacting TDI and/or HDI as a polyisocyanate compound with methyl ethyl ketoxime as a blocking agent.

Epoxy resins are not particularly limited, but include, for example, glycidyl ether type, glycidyl ester type, glycidyl amine type, alicyclic type, and the like.
The rubber type is not particularly limited, but examples thereof include chloroprene rubber type, styrene butadiene type, nitrile rubber type, natural rubber, and silicone rubber.

These organic base resins (B) are usually primary particles and/or secondary particles in which the primary particles are aggregated, and preferably have a particle size of 0.1 to 100 μm. Further, these organic base resins (B) may be used singly or in combination of two or more.

[Resin composition and method for producing resin composition]
The resin composition of the present invention essentially contains hollow particles (A) and an organic base resin (B).

The true specific gravity of the resin composition is preferably 0.3 to 1.4, more preferably 0.4 to 1.3, still more preferably 0.5 to 1.2, particularly 0.6 to 1.1. Preferably, 0.7 to 0.95 is most preferred. If it is less than 0.3, the weight ratio of the hollow particles increases, and the adhesive performance or molded article performance may deteriorate. If it exceeds 1.4, the effect of weight reduction may be insufficient.

The weight ratio of the hollow particles (A) to the resin composition is preferably 0.1 to 30% by weight, more preferably 0.5 to 25% by weight, and still more preferably 1.0 to 15% by weight relative to the entire composition. % by weight, particularly preferably 1.4 to 10% by weight. If the amount is less than 0.1% by weight, the effect of weight reduction may be insufficient. If it exceeds 30% by weight, the weight ratio of the hollow particles is high, and the adhesion performance or molding performance may deteriorate.

The weight ratio of the organic base resin (B) in the resin composition of the present invention is preferably 5 to 65% by weight, more preferably 10 to 55% by weight, and still more preferably 15 to 45% by weight relative to the entire composition. % by weight. Below 5% by weight, excellent adhesive performance may not be obtained, and above 65% by weight, mechanical, thermal and other properties of the molding may not be obtained.

When the resin composition of the present invention contains a plasticizer (C), for example, it weakens the intermolecular force and lowers the glass transition temperature of the organic base resin (B), thereby imparting flexibility, elasticity, adhesiveness, etc. It is preferable because it can improve both the workability of spray coating and the physical performance.
Examples of the plasticizer (C) include di(2-ethylhexyl) phthalate, butylbenzyl phthalate (highly polar plasticizer), dinonyl phthalate, diisononyl phthalate (DINP), diisodecyl phthalate, diundecyl phthalate, diheptyl phthalate, butyl phthalate esters such as phthalyl butyl glycolate and isononyl benzyl phthalate; aliphatic dibasic acid esters such as dioctyl adipate, didecyl adipate and dioctyl sebacate; polyoxyethylene glycol dibenzoate and polyoxypropylene glycol dibenzoate Polyglycol benzoates; trimellitic acid esters; pyromellitic acid esters; phosphoric acid esters such as tributyl phosphate and tricresyl phosphate; alkyl-substituted diphenyls, alkyl-substituted terphenyls, partially hydrogenated alkyl terphenyls, aromatic process oils and hydrocarbons such as pine oil. These may be used individually by 1 type, and may use 2 or more types together. Among them, phthalates are preferable from the viewpoint of cost and versatility.

When the resin composition of the present invention contains a plasticizer (C), the weight ratio of the plasticizer (C) in the resin composition of the present invention is preferably 15 to 60% by weight with respect to the entire composition. ~45% by weight is more preferred. If it is less than 15% by weight, the coating film becomes too hard, and the effect of the present application may not be obtained. If it exceeds 60% by weight, the fluidity of the coating film becomes too high, and the coating film formation may not be sufficient.

Although the resin composition of the present invention is not particularly limited, it is preferably a coating composition, an adhesive composition or a resin clay from the viewpoint that the effects of the present invention are easily exhibited. The paint is not particularly limited, and includes automobile paints such as underbody coating agents and anti-vibration paints; architectural paints such as heat insulating paints, exterior wall paints and waterproof paints; and the like. Adhesives include automotive adhesives such as body sealers, hemming adhesives, structural adhesives, spot sealers, mastic adhesives, and sheet metal reinforcing agents; exterior wall sealants, tile adhesives, dirt floor adhesives, etc. construction adhesive; and the like.
Examples of resin clay include, but are not particularly limited to, lightweight clay used in the field of handicrafts, the field of art, and the field of education such as school teaching materials.

The resin composition according to the present invention contains fillers (calcium carbonate, silicic acid, silicates, carbon black, talc, kaolin, silica, water, etc.) depending on the application such as coating compositions, adhesive compositions, and resin clays. aluminum oxide, antimony trioxide, ferrites, barium titanate, mica, alumina, iron oxide, etc.), hygroscopic agents (calcium oxide, molecular sieves, etc.), thixotropic agents (organic bentonite, fumed silica, aluminum stearate, metal soaps, castor oil derivatives, etc.), stabilizers [2,6-di-t-butyl-4-methylphenol, 2.2-methylene-bis(4-methyl-6-t-butylphenol), dibutyldithiocarbamine acid nickel, lead-based stabilizer, barium/zinc-based stabilizer, calcium/zinc-based stabilizer, organic tin compound, etc.], curing accelerator (dibutyltin dilaurate, lead octylate, bismuth octylate, etc.), latent curing agent A solvent (high-boiling hydrocarbon solvent), an epoxy resin, or the like that does not dissolve the may be appropriately selected and added.

A case where the resin composition of the present invention is an adhesive composition will be described. The adhesive composition is a composition containing the hollow particles (A) and an organic base resin (B) as an adhesive component.
The adhesive component is not particularly limited as long as it is a component capable of adhering between objects, and includes a one-liquid type polyurethane adhesive component, a two-liquid type polyurethane adhesive component, a one-liquid type modified silicone adhesive component, Examples include a two-part type modified silicone adhesive component, a one-part type polysulfide adhesive component, a two-part type polysulfide adhesive component, an acrylic adhesive component, and the like. The adhesive component is preferably at least one selected from a one-component polyurethane adhesive component, a two-component polyurethane adhesive component, a one-component modified silicone adhesive component, and a two-component modified silicone adhesive component.

The one-liquid type polyurethane adhesive component contains an isocyanate group-containing urethane prepolymer as a curing component. In the isocyanate group-containing urethane prepolymer, the isocyanate group reacts with moisture in the air, crosslinks and cures, thereby exhibiting adhesiveness.
Penguin Seal 999 (manufactured by Sunstar Giken Co., Ltd.) is commercially available as a one-liquid type polyurethane adhesive component.

Next, the two-liquid type polyurethane adhesive component consists of two combinations of a urethane prepolymer (hereinafter sometimes referred to as A1) and a curing agent such as polyol (hereinafter sometimes referred to as A2). The two-liquid type polyurethane adhesive component expresses adhesiveness by mixing A1 and A2 to crosslink and cure.
As the two-liquid type polyurethane adhesive component, for example, Penguin Seal PU9000 type NB (manufactured by Sunstar Giken), Hamatite UH-30 (manufactured by Yokohama Rubber Co., Ltd.), Bond PU Seal (manufactured by Konishi Co., Ltd.), etc. are commercially available. .

The one-liquid type modified silicone adhesive component expresses adhesiveness when the crosslinkable silyl group-containing resin reacts with moisture in the air to crosslink and cure. Examples of one-liquid type modified silicone adhesive components include Sealant 45 (manufactured by Shin-Etsu Chemical Co., Ltd.), SH780 Sealant (manufactured by Dow Corning Toray), Penguin Seal 2505 (manufactured by Sunstar Giken), and Hamatite SS-310 ( Yokohama Rubber Co., Ltd.) and the like are commercially available.
Next, the two-liquid type modified silicone adhesive component consists of a siloxane polymer (hereinafter sometimes referred to as B1) and a curing agent such as an organic tin compound (hereinafter sometimes referred to as B2). Adhesiveness is expressed by mixing and reacting. Two-liquid type modified silicone adhesive components include, for example, two-component sealant 74 (manufactured by Shin-Etsu Chemical Co., Ltd.), SE792 sealant (manufactured by Dow Corning Toray), Penguin Seal SR2520 (manufactured by Sunstar Giken Co., Ltd.), and Hamatite Silicone 70. (manufactured by Yokohama Rubber Co., Ltd.), Bond MS Seal (manufactured by Konishi Co., Ltd.), etc. are commercially available.

The one-liquid type polysulfide adhesive component contains a liquid polysulfide resin as a curing component, and a latent curing agent, such as BaO ₂ or CaO ₂ , as a peroxide of an alkali or alkaline earth metal. It reacts with moisture in the air to generate adhesion. As the one-liquid type polysulfide adhesive component, for example, Topcol SP (manufactured by Toray Fine Chemicals Co., Ltd.), Hamatite PS-ONE (manufactured by Yokohama Rubber Co., Ltd.) and the like are commercially available.
The two-liquid type polysulfide adhesive component consists of a base made of a sulfide polymer (hereinafter sometimes referred to as C1) and a curing agent containing a metal peroxide such as PdO ₂ (hereinafter sometimes referred to as C2). Adhesiveness is generated by mixing. Two-liquid type polysulfide adhesive components are commercially available, for example, Penguin Seal PS169N (manufactured by Sunstar Giken) and Hamatite SC-M500 (manufactured by Yokohama Rubber).

The acrylic adhesive component consists of an acrylic acid ester polymer emulsion, and adhesiveness is generated by evaporation of water. The acrylic adhesive component is commercially available under trade names such as Penguin Seal 1250 (manufactured by Sunstar Giken Co., Ltd.).
The weight ratio of the hollow particles (A) and the adhesive component (hollow particles (A)/adhesive component) blended in the resin composition is not particularly limited, but is preferably 0.0005 to 0.30, more preferably 0.0005 to 0.30. is 0.001 to 0.20, particularly preferably 0.01 to 0.1. When the hollow particle (A)/adhesive component (weight ratio) is less than 0.0005, the amount of the hollow particle (A) added is too small, and the effect of improving the elongation of the cured product of the resin composition is diminished. It may get lost. On the other hand, when the hollow particle (A)/adhesive component (weight ratio) is more than 0.30, the amount of the adhesive component is too small, and the function as an adhesive composition may be remarkably deteriorated. Here, the adhesive component means the total amount of A1 and A2 in the case of a two-part type polyurethane adhesive component, and the total amount of B1 and B2 in the case of a two-part type modified silicone adhesive component, In the case of a two-liquid type polysulfide adhesive component, it means the total amount of C1 and C2.
A cured product obtained from the adhesive composition has a high elongation, and the cured product is less likely to break when deformed by an external force or the like.

When the resin composition of the present invention is resin clay, it contains polyvinyl alcohol as the hollow particles (A) and the organic base resin (B).
The degree of saponification of the polyvinyl alcohol used in the present invention is preferably 70-99 mol %, more preferably 80-90 mol %, even more preferably 85-90 mol %. When the degree of saponification is within this range, workability during modeling is good.
The polyvinyl alcohol used in the present invention preferably has a viscosity of 2 to 60 mPa·s, more preferably 4 to 50 mPa·s, and even more preferably 10 to 45 mPa·s in a 4% aqueous solution at 20°C. When the viscosity of the polyvinyl alcohol is within this range, workability during modeling is improved.

The amount of polyvinyl alcohol blended in the resin clay is preferably in the range of 2 to 15% by weight, more preferably in the range of 5 to 12% by weight, based on the total weight of the resin clay. If the amount of polyvinyl alcohol is less than 2% by weight, the adhesiveness (plasticity, extensibility) during modeling deteriorates. physical properties may deteriorate.
Polyvinyl alcohol is desirable in that when it is blended in a gel state with a gelling agent, a clay with "firmness" can be obtained. Examples of the gelling agent include Glauber's salt (sodium sulfate), potassium alum (alum), boric acid, and borax. The amount of the gelling agent is preferably 2 to 15 parts by weight, more preferably 8 to 15 parts by weight, per 100 parts by weight of polyvinyl alcohol.

The resin clay of the present invention may contain vinyl acetate resin. Vinyl acetate resins include, for example, polyvinyl acetate, poly-modified vinyl acetate, ethylene-vinyl acetate copolymer resin, vinyl acetate-vinyl versatate copolymer resin, vinyl acetate-acrylic acid copolymer, vinyl acetate-acrylic acid ester copolymer. Examples thereof include coalescence, vinyl acetate/methacrylic acid copolymer, vinyl acetate/methacrylic acid ester copolymer, vinyl acetate/acrylamide copolymer, vinyl acetate/diene copolymer, and the like. This vinyl acetate resin is used in the form of powder or emulsion, and is usually used in the form of emulsion. When used in the form of an emulsion, it is desirable to use one containing 50% or more of the vinyl acetate resin component.
The vinyl acetate resin used in the present invention preferably has a 59% aqueous solution viscosity of 1,000 to 150,000 mPa·s at 30°C. The vinyl acetate-based resin imparts plasticity to the resin clay and retains the shape of the molded object after molding and drying.

A vinyl acetate resin to which a plasticizer is added is preferred. Examples of the plasticizer include dibutyl phthalate. The blending amount of the plasticizer is desirably 4 to 10% by weight based on the weight of the vinyl acetate resin emulsion. The amount of the vinyl acetate resin containing the plasticizer is preferably 1.5 to 7% by weight (expressed by dry weight), particularly 2 to 5% by weight, based on the total resin clay. The mixing ratio of polyvinyl alcohol and vinyl acetate resin containing a plasticizer is preferably 10:7 to 10:3 by weight. If the blending ratio of the vinyl acetate resin containing the plasticizer exceeds 7, the clay may become sticky and the moldability may be impaired.

The resin clay of the present invention may contain polyethylene oxide. Polyethylene oxide is a polymer obtained by ring-opening polymerization of ethylene oxide, and is a water-soluble high polymer having ether groups in the middle and hydroxyl groups at the ends. The polyethylene oxide used in the present invention preferably has a viscosity average molecular weight of about 300,000 to 1,200,000, more preferably 600,000 to 800,000. A 2.0% by weight aqueous solution at 25° C. preferably has a viscosity of 100 to 2000 mPa·s, particularly 200 to 700 mPa·s (measured with a rotational viscometer). Further, it is desirable that the melting point is 65 to 67°C. Polyethylene oxide having the physical properties described above has excellent compatibility with hollow particles, polyvinyl alcohol, and vinyl acetate resin. Polyethylene oxide improves the plasticity and extensibility of the clay during modeling, and improves the adhesiveness of the clay to reduce adhesion to the hands, making the modeling work more comfortable. The blending amount is preferably 0.5 to 1.5% by weight (expressed by dry weight) with respect to the entire resin clay. When the content of polyethylene oxide is less than 0.5% by weight, the resulting clay exhibits favorable extensibility and surface smoothness during molding. There is a risk.

In addition to those mentioned above, carboxymethylcellulose salts, methylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, natural polymer guar gum, and guar gum derivatives can be added to the resin clay of the present invention. These improve the extensibility of the clay, improve the surface smoothness, and improve the feel of the clay.
In addition to the above, fiber powder can be added to the resin clay of the present invention. The fiber powder enhances shape retention after shaping and drying, and also has an effect of preventing shrinkage. Examples of the above-mentioned fiber powder include pulp powder, vinylon fiber, cotton powder, crushed sheet pulp, and the like. The length of the fiber powder is preferably 0.5 to 5.5 mm, preferably 1 to 3 mm, preferably natural fibers or synthetic fibers. The blending amount is preferably 0.5 to 4% by weight based on the total weight of the clay.
Moisturizers can be added to the clay of the present invention in addition to those described above. Humectants include liquid paraffin, sorbitol, polyethylene glycol, propylene glycol and the like. The blending amount of the moisturizing agent is preferably 0.5 to 1.5% by weight based on the entire resin clay. The blending amount of water is preferably 50 to 80% by weight, more preferably 60 to 75% by weight, based on the total resin clay.

The method for producing the resin composition of the present invention comprises the above steps (1), (2) and (3), and the hollow particles (A) obtained in step (3) and the organic base resin (B) and a step (4) of mixing. In step (4), the hollow particles (A) and the organic base resin (B) are blended, and when other components such as a plasticizer (C) are further included, these components are blended, and a conventionally known A step of collectively mixing using a means (for example, a planetary mixer) can be mentioned.

[Molded product]
The molded article of the present invention is obtained by molding the above resin composition. More specifically, when the resin composition of the present invention is an adhesive composition or a coating composition, the molded article of the present invention is obtained by applying the resin composition to an object, drying it, and curing it. .
More specifically, the above resin composition can be applied to various undercoated surfaces applied to various metal (especially steel) surfaces, and is particularly advantageously applicable to cationic electrodeposition coated surfaces. The amount of the resin composition to be applied to the coated surface is preferably 200 to 2,000 g/m2, and the coating thickness is preferably 0.2 to 20 mm from the viewpoint of physical properties of the coating film. Examples of coating methods include brush coating, roller coating, and airless spray coating.
In addition, heat treatment is performed after coating, and the temperature in that case is preferably 110 to 200° C., more preferably 120 to 180° C., from the viewpoint of curability of the resin composition. The heat treatment time is preferably 8 to 60 minutes from the viewpoint of curability of the resin composition.

In the above molded article, the true specific gravity when the resin composition is treated at 120 ° C. for 10 minutes is D1, and the true specific gravity when the resin composition is treated at 140 ° C. for 20 minutes is D2.
preferably satisfies 0.85<(D2/D1)<1.1,
It is more preferable to satisfy 0.87<(D2/D1)<1.07,
It is more preferable to satisfy 0.89<(D2/D1)<1.04,
It is particularly preferable to satisfy 0.91<(D2/D1)≦1.0.
If it is less than 0.85, the surface smoothness may deteriorate and the adhesion performance may deteriorate. If it is 1.1 or higher, the number of closed cells composed of hollow particles decreases, and fine holes and voids caused by leakage of the encapsulating agent may cause deterioration in adhesion performance or extremely lightweight moldings. may not be obtained.

The molded article of the present invention obtained by molding the resin composition of the present invention is strongly adhered to the painted metal surface and is lightweight. Therefore, the molded product of the present invention can be used as an adhesive, sealant, paint, etc. for various industrial applications, especially in the automobile industry, where it is an excellent underbody coating material, sealing material, and adhesive for hemming of automobile bodies subjected to cationic electrodeposition coating. When used as an adhesive, a structural adhesive, a spot sealer, a mastic adhesive, a sheet metal reinforcing material, and a body sealer, it can contribute to automobiles having excellent strength, light weight, and excellent fuel efficiency.

EXAMPLES The present invention will be described in detail with the following examples and comparative examples, but the present invention is not limited thereto. Hereinafter, "%" means "% by weight" and "parts" means "parts by weight" unless otherwise specified.
In the following, production examples and comparative production examples of thermally expandable microspheres, which are raw materials for hollow particles, are shown first, and then examples and comparative examples of resin compositions containing hollow particles are shown. The physical properties of the heat-expandable microspheres and hollow particles were measured according to the following procedures, and their performance was further evaluated.
Examples 4, 5, 6 and 7 are reference examples.

[Measurement of 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, the degree of vacuum was 5.0 mbar, and the dry measurement method was used.
The volume-based cumulative particle diameter means the diameter of particles with respect to a predetermined ratio of the cumulative distribution obtained by accumulating all particles in order of volume.
In principle, the laser diffraction particle size distribution analyzer measures the volume-based cumulative particle size distribution, and the measurement value of the volume-based cumulative 50% particle size (D50) can be confirmed with the software of the measuring device.
The number-based cumulative particle diameter means the diameter of particles in a predetermined number ratio of a cumulative distribution obtained by arranging all particles in particle order and accumulating them from the smaller side. The number-based cumulative particle size can be converted from the volume-based cumulative particle size using the software of the measuring device.

[Measurement of moisture content of thermally expandable microspheres]
A Karl Fischer moisture meter (MKA-510N type, manufactured by Kyoto Electronics Industry Co., Ltd.) was used as a measuring device.

[Measurement of Encapsulation Rate of Foaming Agent Encapsulated in Thermally Expandable Microspheres]
1.0 g of heat-expandable microspheres were placed in a stainless steel evaporating dish with a diameter of 80 mm and a depth of 15 mm, and the weight (W ₁ ) was measured. After adding 30 ml of acetonitrile and dispersing it uniformly, it was allowed to stand at room temperature for 30 minutes, then heated at 120° C. for 2 hours, and the weight (W ₂ ) after drying was measured. The encapsulation rate of the foaming agent is calculated by the following formula.
Encapsulation rate (% by weight) = (W ₁ - W ₂ ) (g) / 1.0 (g) x 100 - (moisture content) (% by weight)
(In the formula, the water content is measured by the method described above.)

[Measurement of Encapsulation Ratio of Foaming Agent Encapsulated in Hollow Particles]
0.20 g of hollow particles were placed in a stainless steel evaporating dish having a diameter of 80 mm and a depth of 15 mm, and the weight (W ₁ ) was measured. After adding 30 ml of acetonitrile and dispersing it uniformly, it was allowed to stand at room temperature for 30 minutes, then heated at 120° C. for 2 hours, and the weight (W ₂ ) after drying was measured. The encapsulation rate of the foaming agent is calculated by the following formula.
Encapsulation rate (G) = (W ₁ - W ₂ ) (g) / 0.20 (g) x 100 - (moisture content) (% by weight)
(In the formula, the water content is measured by the method described above.)

[Measurement of True Specific Gravity of Thermally Expandable Microspheres and Hollow Particles]
The true specific gravities of the heat-expandable microspheres and hollow particles were measured by the following method.
The true specific gravity was measured by a liquid immersion method (Archimedes method) using isopropyl alcohol in an atmosphere with an environmental temperature of 25° C. and a relative humidity of 50%.
Specifically, a volumetric flask with a capacity of 100 cc was emptied, and after drying, the volumetric flask weight (WB ₁ ) was measured. After accurately filling the weighed volumetric flask with isopropyl alcohol up to the meniscus, the weight (WB ₂ ) of the volumetric flask filled with 100 cc of isopropyl alcohol was weighed.

Also, a 100 cc volumetric flask was emptied, and after drying, the weight of the volumetric flask (WS ₁ ) was measured. A weighed volumetric flask was filled with approximately 50 cc of particles and the weight (WS ₂ ) of the volumetric flask filled with particles was weighed. Then, the volumetric flask filled with the particles was filled with isopropyl alcohol to the meniscus without air bubbles, and then the weight (WS ₃ ) was weighed. Then, the obtained WB ₁ , WB ₂ , WS ₁ , WS ₂ and WS ₃ were introduced into the following formula to calculate the true specific gravity (d) of the particles.
d(d _b )={(WS ₂ −WS ₁ )×(WB ₂ −WB ₁ )/100}/{(WB ₂ −WB ₁ )−(WS ₃ −WS ₂ )}
In the above, the true specific gravity was calculated using hollow particles as the particles.

[Volume ratio (Z) of air intake to hollow particles]
300 ml of hollow particles are placed in the following aluminum container. In order to measure the volume of the specified amount of hollow particles, the weight obtained by the following formula may be measured.
Weight of hollow particles (W) (g) = volume of hollow particles (V) (ml) x true specific gravity of hollow particles (d) (g/cc)
Aluminum container: Use an aluminum container (maximum capacity: 1.4 L, film thickness: 114 μm: Lamizip AL-18) having no gas permeability under an ambient temperature of 25° C. and a relative humidity of 50%. In the aluminum container, the aluminum film itself does not expand or contract due to changes in the internal volume, but the shape of the bag is deformed.
Next, the aluminum container is made to have a volume of about 900 ml, and the opening is sealed by thermal welding. Using the immersion method (Archimedes method), the volume (Y1) (ml) of the sealed aluminum container is measured. The sealed aluminum container is allowed to stand for 7 days under an ambient temperature of 25° C. and a relative humidity of 50%. After the period has elapsed, the volume (Y2) (ml) of the sealed aluminum container is measured using a liquid immersion method (Archimedes method). The volume ratio (Z) of the amount of air taken in relative to the hollow particles was calculated using the following formula.
Volume ratio (Z) of air intake to hollow particles = (Y1-Y2)/300
<Aging evaluation criteria>
(Z)<−0.2:×
-0.2 ≤ (Z) < -0.05: △
-0.05 ≤ (Z) ≤ 0.05: ◎
0.05 < (Z) ≤ 0.2: ○
0.2 < (Z) ≤ 1: △
1<(Z): ×

[Volume ratio (P) of the amount of air contained in the hollow particles]
The hollow particles W (g) are placed in a 1 L container, filled with DMF (dimethylformamide), and then sealed. The container is heated at 90° C. for 12 hours, and the generated gas is collected by a modified water replacement method using DMF. Measure the amount of gas collected by the water replacement method, and measure the oxygen concentration in the gas with an oxygen gas sensor (model: PS-2126A, measurement method: galvanic cell type). The amount of air contained in the hollow particles can be quantified from the amount of gas collected and the oxygen concentration in the gas. The amount of air in the collected gas was calculated by the following formula.
Air volume (V) in the collected gas = V1 x C/20.9
Collected gas volume (V1) (ml)
Oxygen concentration in gas (C) (% by volume)
The volume ratio (P) of the amount of air contained in the hollow particles was calculated using the following formula. The volume ratio (P) is a ratio when the volume of the entire hollow particles (A) is 100%.
Volume ratio (P) (%) of the amount of air contained in the hollow particles = V x d x 100/W
Weight of hollow particles: W (g)
True specific gravity of hollow particles: d (g/cc)
<Aging evaluation criteria>
(P) < 10: ×
10% ≤ (P) < 30%: △
30% ≤ (P) < 50%: ○
50% ≤ (P): ◎
[Measurement of true specific gravity of resin composition]
The true specific gravity (dpo) of the resin composition was measured using an Elcometer 1800 stainless steel specific gravity cup (100 ml).
The mass We (g) of the empty specific gravity cup was measured, and the mass Ws (g) of the specific gravity cup filled with the resin composition was measured and calculated.
dpo = (Ws-We)/100 (g/cc)

[Measurement of true specific gravity of molding]
The true specific gravity of the molding was measured in solid specific gravity measurement mode using a Shimadzu precision electronic analytical balance AX200 (manufactured by Shimadzu Corporation).

[Production Example 1]
To 600 g of ion-exchanged water, 100 g of sodium chloride, 40 g of colloidal silica having a silica active ingredient content of 20% by weight, 2 g of polyvinylpyrrolidone, and carboxymethylated polyethyleneimine (CMPEI; substituted alkyl group: —CH ₂ COONa, substitution rate : 80%, weight average molecular weight: 50,000) was added, and the pH of the resulting mixture was adjusted to 2.8 to 3.2 to prepare an aqueous dispersion medium. CMPEI is the same as described in paragraph 0140 of International Publication No. 2008/142849 pamphlet.
Separately, 150 g of acrylonitrile, 100 g of methacrylonitrile, 15 g of isobornyl methacrylate, 0.5 g of diethylene glycol dimethacrylate, 30 g of isobutane, 50 g of isopentane as blowing agents, and 70% pure di-2-ethylhexylperoxydiethylene An oily mixture was prepared by mixing 3 g of carbonate. An aqueous dispersion medium and an oily mixture were mixed, and the resulting mixture was dispersed with a homomixer (TK homomixer, manufactured by Primix) at a rotation speed of 12000 rpm for 2 minutes to prepare a suspension. This suspension was transferred to a pressurized reactor with a capacity of 1.5 liters, and after nitrogen substitution, the initial reaction pressure was set to 0.5 MPa, and polymerization was carried out at a polymerization temperature of 55° C. for 20 hours while stirring at 80 rpm. After polymerization, the polymerized product was filtered and dried to obtain heat-expandable microspheres.

[Production Examples 2 to 5]
In Production Examples 2 to 5, heat-expandable microspheres were obtained by polymerization in the same manner as in Example 1, except that the reaction conditions were changed as shown in Table 1. Furthermore, the physical properties were evaluated and shown in Table 1.

In Table 1 above, the following abbreviations are used.
CMPEI: polyethyleneimines (substituted alkyl group: —CH ₂ COONa, substitution rate of substituted alkyl group: 80%, weight average molecular weight: 50,000). In addition, it is also described as carboxymethylated polyethyleneimine.Na salt.
PVP: polyvinylpyrrolidone AN: acrylonitrile MAN: methacrylonitrile IBX: isobornyl methacrylate VCl ₂ : vinylidene chloride MMA: methyl methacrylate TMP: trimethylolpropane trimethacrylate EDMA: diethylene glycol dimethacrylate OPP: di-2-ethylhexyl peroxydicarbonate (Purity 70%)
Colloidal silica (average particle size 11 nm, specific surface area 260 m ² /g, colloidal silica effective concentration 20% by weight dispersion)

The hollow particles (a) before aging were produced by the wet heat expansion method described in JP-A-62-201231, and hollow particles (A) and A resin composition was prepared and evaluated.

[Example 1]
An aqueous dispersion (slurry) containing 5% by weight of the heat-expandable microspheres obtained in Production Example 1 was prepared. According to the wet thermal expansion method described in JP-A-62-201231, this slurry is fed from a slurry introduction pipe into a foaming pipe (diameter 16 mm, volume 120 ml, made of SUS304TP) at a flow rate of 5 L / min, and further steam ( Temperature: 147°C, pressure: 0.3 MPa) was supplied from a steam introduction pipe, mixed with the slurry, and expanded by wet heating. The slurry temperature (foaming temperature) after mixing was adjusted to 115°C.
The obtained slurry containing the hollow particles was allowed to flow out from the projection of the foaming tube, mixed with cooling water (water temperature: 15°C), and cooled to 50 to 60°C. The cooled slurry liquid was dehydrated with a centrifugal dehydrator to obtain a hollow particle composition containing 10% by weight of the moistened hollow particles (a) (that is, containing 90% by weight of water).
The obtained hollow particles (a) were aged at 40° C. for 24 hours to obtain a hollow particle composition containing 10% by weight of the hollow particles (A). The volume ratio (Z) of the amount of air taken into the hollow particles and the volume ratio (P) of the amount of air contained in the hollow particles were measured. Table 2 shows the evaluation results.

840 parts by weight of the hollow particle composition containing the above hollow particles (A), 200 parts by weight of polyvinyl alcohol, 840 parts by weight of vinyl acetate, 20 parts by weight of boric acid and 1000 parts by weight of water were mixed using a universal mixer. Mix for 5 minutes to obtain a lightweight polymer clay. If the aging is sufficient, the hollow particles will not be crushed, and a lightweight resin clay that is sufficiently lightened and non-sticky can be obtained. Table 2 shows the physical property evaluation results of the obtained hollow particles (A) and lightweight resin clay.
The specific gravity increase rate of the resin clay specific gravity actually obtained with respect to the theoretical specific gravity was calculated by the following formula.
Specific gravity increase rate (%) = (resin clay specific gravity / theoretical specific gravity - 1) × 100

Regarding the stickiness evaluation of the resin clay, when a model is created using the obtained clay, it is determined whether the clay does not stick to the hands and the clays adhere well to each other to exhibit good molding properties. evaluated.
◯: The clay does not adhere to hands and adheres well to each other.
Δ: Adheres to hands, but also adheres to clay.
x: Adheres to the hands and the clays hardly stick to each other.

[Examples 2 and 3 and Comparative Examples 1 to 4]
Examples 2 and 3 and Comparative Examples 1 to 4 were prepared in the same manner as in Example 1, except that the thermally expandable microspheres, composition, conditions, etc., were changed as shown in Table 2. A lightweight polymer clay was obtained. Table 2 shows physical properties.

As can be seen from Table 2, in Examples 1 to 3, since sufficient aging treatment was performed before being used as a weight-reducing filler for the resin composition, the inside and outside of the hollow particles (A) There is no air concentration gradient, and almost no amount of air is taken into the interior of the hollow particles (A). As a result, it was confirmed that the hollow particles have sufficient resistance to external pressure load during mixing and filling in the production process of the resin composition, and the effect of the present application is obtained.
On the other hand, when the aging period was insufficient (Comparative Examples 1 to 4), when used as a weight-reducing filler for a resin composition, the hollow particles were destroyed by external pressure during mixing and filling in the production process. However, the specific gravity of the resin composition deviates greatly from the theoretical specific gravity when the resin composition is designed, and the effect of weight reduction becomes insufficient, and the effect of the present application cannot be obtained.

The hollow particles (a) before aging are produced by the dry heat expansion method described in JP-A-2006-213930, and the hollow particles (A) and the resin are prepared as in Examples 4 to 6 and Comparative Examples 5 to 7 below. Compositions were prepared and evaluated.

[Example 4]
(Production of hollow particles (a) by dry thermal expansion method)
The internal injection method described in Japanese Patent Application Laid-Open No. 2006-213930 was employed as the dry thermal expansion method. Specifically, hollow particles (a) were produced using the heat-expandable microspheres obtained in Production Example 4 according to the following procedure using a production apparatus equipped with a foaming process section shown in FIG. .

(Description of the foaming process section)
As shown in FIG. 2, the foaming process section includes a gas introduction pipe (not numbered) equipped with a dispersion nozzle (11) at the outlet and arranged in the center, and a A collision plate (12), a desuperheating cylinder (10) spaced around the gas introduction pipe, and a hot air nozzle (8) spaced around the desuperheating cylinder (10). Prepare. In this foaming process section, a gas fluid (13) containing heat-expandable microspheres is flowed in the direction of the arrow in the gas introduction pipe, and the space formed between the gas introduction pipe and the overheating prevention tube (10) is filled with has a gas flow (14) flowing in the direction of the arrow for improving the dispersibility of the thermally expandable microspheres and preventing overheating of the gas introduction pipe and the impingement plate, and furthermore, an overheating prevention cylinder (10) and a hot air nozzle. A hot air flow for thermal expansion flows in the direction of the arrow in the space formed between (8). Here, the hot air flow (15), the gaseous fluid (13) and the gaseous flow (14) generally flow in the same direction. A coolant flow (9) flows in the direction of the arrow inside the overheating prevention tube (10) for cooling.

(Operation of manufacturing equipment)
In the injection step, the gaseous fluid (13) containing the thermally expandable microspheres is caused to flow through a gas introducing pipe provided with a dispersion nozzle (11) at the outlet and installed inside the hot air flow (15), and the gaseous fluid (13) is jetted from the dispersion nozzle (11).
In the dispersing step, the gaseous fluid (13) is made to collide with a collision plate (12) installed downstream of the dispersing nozzle (11) so that the thermally expandable microspheres are evenly dispersed in the hot air stream (15). operated by Here, the gaseous fluid (13) coming out of the dispersion nozzle (11) is guided together with the gaseous stream (14) towards the impingement plate (12) and collides therewith.
In the expansion step, the dispersed heat-expandable microspheres are heated in a hot air flow (15) to a temperature equal to or higher than the expansion start temperature and expanded. After that, the obtained hollow particles are collected by, for example, passing through a cooling section.

(Expansion conditions and results)
Using the production apparatus shown in FIG. 2, the expansion conditions were set to 0.8 kg/min of raw material supply, 0.35 m3/min of raw material dispersion gas, 8.0 m3/min of hot air flow rate, and 290° C. of hot air temperature. of hollow particles (a) were obtained.
The resulting hollow particles (a) were aged at 30° C. for 36 hours to obtain hollow particles (A). The volume ratio (Z) of the amount of air taken into the hollow particles and the volume ratio (P) of the amount of air contained in the hollow particles were measured. Table 3 shows the evaluation results.
(Manufacture of resin composition)
Obtained hollow particles (A) (14 parts by weight) 1.4% by weight, PVC resin (376 parts by weight) 37.6% by weight as organic base resin, diisononyl phthalate (220 parts by weight) as plasticizer (C) 22% by weight, 37.0% by weight of calcium carbonate (370 parts by weight) as a filler, and 2% by weight of a barium/zinc stabilizer (AC-290: manufactured by Adeka Co., Ltd.) (20 parts by weight) as a stabilizer were thoroughly kneaded. , to obtain a resin composition (specific gravity 0.75).
The specific gravity of the obtained resin composition after being pressurized in a pressurizing cylinder at a pressure of 5 MPa for 30 minutes was 0.76. At this time, the rate of increase in specific gravity of the resin composition due to pressure treatment was calculated by the following formula.
Specific gravity increase rate (%) = (specific gravity of resin composition after pressure / specific gravity of resin composition before pressure - 1) x 100

(Manufacture of moldings)
The resin composition obtained above was applied to an electrodeposition coated plate (thickness: 2 mm), and heat-treated at 140°C for 20 minutes to obtain a molded product. Table 3 shows physical properties.

[Example 5 and Comparative Examples 5 and 6]
Example 5 and Comparative Examples 5 and 6 were prepared in the same manner as in Example 4, except that the thermally expandable microspheres, the expansion temperature, the aging conditions, etc. were changed as shown in Table 3. , a resin composition, and a molding were obtained. Table 3 shows physical properties.

As can be seen from Table 3, in Examples 4 and 5, since sufficient aging treatment was performed before being used as a weight-reducing filler for the resin composition, the inside and outside of the hollow particles (A) There is no air concentration gradient, and almost no amount of air is taken into the interior of the hollow particles (A). As a result, it was confirmed that the hollow particles have sufficient resistance to the load due to the external pressure expected when the resin composition is used, and the effect of the present application is obtained.
On the other hand, in cases where the aging period was insufficient (Comparative Examples 5 and 6), when used as a weight-reducing filler for the resin composition, the hollow particles were destroyed by the load due to the external pressure assumed when the resin composition was used. As a result, the effect of reducing the weight of the resin composition is insufficient, and the effect of the present application has not been obtained.

[Example 6]
20 parts by weight of the heat-expandable microspheres obtained in Production Example 3 (softening point of the thermoplastic resin constituting the outer shell: 109 ° C.), calcium carbonate (Whiten SB red manufactured by Bihoku Funka Kogyo Co., Ltd.; laser 80 parts by weight of the average particle size of about 1.8 μm by diffraction method) was added and mixed in a separable flask. Next, while stirring, the temperature was raised to 130° C. over 5 minutes to obtain pre-aging hollow particles (a) to which the fine particle filler adhered.
The obtained hollow particles (a) were aged at 10° C. for 60 hours to obtain hollow particles (A). The volume ratio (Z) of the amount of air taken into the hollow particles and the volume ratio (P) of the amount of air contained in the hollow particles were measured. Table 4 shows the evaluation results.

[Adhesive composition]
80 parts by weight of a curing agent component for a two-liquid type polyurethane adhesive component (Bond UP Seal Gray, manufactured by Konishi Co., Ltd.), 3.8 parts by weight of hollow particles (A) as a modifier for an adhesive composition, 2 parts by weight of hydrocarbon (IP-2835 manufactured by Idemitsu Kosan Co., Ltd.) was added, and the mixture was stirred and mixed using a planetary mixer (PLM-50 manufactured by Inoue Seisakusho Co., Ltd.) at 50 ° C. for 30 minutes, and then degassed under reduced pressure. A polyurethane adhesive curing agent composition was obtained. The specific gravity of the obtained polyurethane adhesive curing agent composition (curing agent composition) was measured, and the specific gravity increase rate of the actually obtained curing agent composition relative to the theoretical specific gravity was calculated by the following formula. Table 4 shows the results.
Specific gravity increase rate (%) = (curing agent composition specific gravity/theoretical specific gravity -1) x 100

Subsequently, 85.8 parts by weight of the curing agent composition and 20 parts by weight of the base component of the polyurethane adhesive component (Bond UP Seal Gray, manufactured by Konishi Co., Ltd.) were added and premixed. , AR-360), the mixture was stirred at 500 rpm for rotation and 2000 rpm for revolution for 150 seconds for degassing to obtain an adhesive composition. The obtained adhesive composition was cured under conditions of 23° C. and 50% RH for 3 days, and further cured under conditions of 50° C. and 50% RH for 3 days, and then the specific gravity of the cured molding was measured. Table 4 shows the results.

[Example 7 and Comparative Examples 7 and 8]
Example 7 and Comparative Examples 7 and 8 were prepared in the same manner as in Example 6, except that the thermally expandable microspheres, the expansion temperature, the aging conditions, etc. were changed as shown in Table 3. , a resin composition, and a molding were obtained. Table 4 shows physical properties.

As can be seen from Table 4, in Examples 6 and 7, since sufficient aging treatment was performed before being used as a weight-reducing filler for the resin composition, the inside and outside of the hollow particles (A) There is no air concentration gradient, and almost no amount of air is taken into the interior of the hollow particles (A). As a result, it was confirmed that the hollow particles have sufficient resistance to external pressure load during mixing and filling in the production process of the resin composition, and the effect of the present application is obtained.
On the other hand, in cases where the aging period was insufficient (Comparative Examples 7 and 8), when used as a weight-reducing filler for a resin composition, the hollow particles were destroyed by external pressure during mixing and filling in the production process. However, the specific gravity of the resin composition deviates greatly from the theoretical specific gravity when the resin composition is designed, and the effect of weight reduction becomes insufficient, and the effect of the present application cannot be obtained.

The resin composition of the present invention can be suitably used for paints, adhesives and resin clays.

4 Hollow particles (A1)
5 Outer shell 6 Particulate filler (adsorbed)
7 Fine particle filler (embedded, fixed state)
8 Hot Air Nozzle 9 Refrigerant Flow 10 Desuperheating Cylinder 11 Distributing Nozzle 12 Collision Plate 13 Gas Fluid Containing Thermally Expandable Microspheres 14 Gas Flow 15 Hot Air Flow

Claims (4)

A resin composition containing hollow particles (A) and an organic base resin (B),
The resin composition is a coating composition or resin clay,
The hollow particles (A) are expanded bodies of thermally expandable microspheres composed of an outer shell made of a thermoplastic resin and a foaming agent enclosed therein and vaporized by heating,
The foaming agent is enclosed in the hollow particles (A),
the blowing agent comprises isobutane;
The volume ratio (P) of the amount of air contained in the hollow particles (A) is 30% or more when the volume of the entire hollow particles (A) is 100%.
Resin composition. 2. The resin composition according to claim 1, wherein the encapsulation rate of said foaming agent enclosed in said hollow particles (A) is 9.8 to 18.1% by weight. A molded article obtained by molding the resin composition according to claim 1 or 2. Step (1) of obtaining thermally expandable microspheres composed of an outer shell made of a thermoplastic resin and a foaming agent encapsulated therein and vaporized by heating;
a step (2) of thermally expanding the heat-expandable microspheres to obtain hollow particles (a);
A step (3) of aging the hollow particles (a) at a temperature in the range of -10 to 80°C to obtain hollow particles (A);
and a step (4) of mixing the obtained hollow particles (A) and the organic base resin (B),
The foaming agent is enclosed in the hollow particles (A),
the blowing agent comprises isobutane;
The volume ratio (P) of the amount of air contained in the hollow particles (A) is 30% or more when the volume of the entire hollow particles (A) is 100%,
A method for producing a resin composition that is a coating composition or resin clay.

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