JP2008239794A - Self-extinguishing carbon-containing modified polystyrene resin particle, expandable self-extinguishing carbon-containing modified polystyrene resin particle, self-extinguishing carbon-containing modified polystyrene resin foamed particle, self-extinguishing carbon-containing modified polystyrene resin foamed molded product, and manufacturing methods therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a self-extinguishing carbon-containing modified PP foamed molded product having the self-extinguishing property while preferably maintaining rigidity, foaming molding property, chemical resistance, and heat resistance by improving shortcomings of both PS foamed molded product and PP foamed molded product. <P>SOLUTION: The self-extinguishing carbon-containing modified polystyrene resin particle contains 100 mass parts and more and less than 400 mass parts of PS to 100 mass parts of a carbon-containing PP. It has a PS ratio calculated by the absorbance ratio (D<SB>698</SB>/D<SB>1376</SB>) at 698 cm<SP>-1</SP>and 1,376 cm<SP>-1</SP>obtained from infrared absorption spectra of the particle central part measured by the ATR infrared spectroscopic analysis of 1.2 or more times the PS ratio of the total particles. The self-extinguishing carbon-containing modified polystyrene resin particles contain 1.5 mass parts and more and less than 6 mass parts of a flame retardant and 0.1 mass part and more and less than 3 mass parts of a flame retardant aid to 100 mass parts of the carbon-containing modified polystyrene resin particle. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

 The present invention relates to a self-extinguishing carbon-containing modified polystyrene resin particle obtained by polymerizing styrene using a polypropylene resin containing carbon as a core and impregnating a flame retardant and a flame retardant aid, Expandable self-extinguishing carbon-containing modified polystyrene resin particles impregnated with a foaming agent, self-extinguishing carbon-containing modified polystyrene resin foam particles obtained by pre-expanding the particles, and foaming the foamed particles in the mold The present invention relates to a self-extinguishing carbon-containing modified polystyrene resin foam molding obtained by molding, and a method for producing the same.

 Conventionally, in order to impart self-extinguishing properties to a styrene resin, it is known to use a composite flame retardant in which a flame retardant and a flame retardant aid are combined. Examples of the flame retardant include tetrabromocyclooctane, hexabromocyclododecane, tetrabromobizphenol A diallyl ether, hexabromocyclododecane, and tri (2,3-dibromopropyl) isocyanate. Examples of the flame retardant aid include 2,3-dimethyl-2,3-diphenylbutane, 3,4-dimethyl-3,4-diphenylhexane, dicumyl peroxide, cumene hydroperoxide, and the like. Many things which gave the self-extinguishing property to styrene resin using the said flame retardant and flame retardant adjuvant are disclosed.

In addition, the polystyrene resin foam molded article obtained by filling polystyrene resin pre-expanded particles in a mold and heating and foaming is excellent in rigidity, heat insulation, light weight, water resistance and foam moldability. Are known. Therefore, this foaming molding is widely used as a buffer material or a heat insulating material for building materials. However, this foam molded article has a problem that it is inferior in chemical resistance and impact resistance.
On the other hand, it is known that a foam molded article made of a polyolefin resin is excellent in chemical resistance and impact resistance. Therefore, this foaming molding is used for automobile-related parts. However, since the polyolefin resin is inferior in foaming gas retention, it is necessary to precisely control the foam molding conditions, resulting in a high manufacturing cost. In addition, there is a problem that the rigidity is inferior to that of the polystyrene-based resin foam molding.
In order to solve the problems of the polystyrene resin and polyolefin resin, foam molding in which a polystyrene resin having good rigidity and foam moldability and a polyolefin resin having good chemical resistance and impact resistance are combined. A body has been proposed (see, for example, Patent Documents 1 to 4).

Patent Document 5 discloses a flame-retardant thermoplastic resin composition in which a halogen-based flame retardant, a phosphorus-based flame retardant, an inorganic flame retardant, or the like is blended with a styrene resin as a flame retardant.
In Patent Document 6, tris (2,3-dibromopropyl) isocyanurate as a flame retardant and 2,3-dimethyl-2,3-diphenylbutane as a flame retardant, or 3,4- Self-extinguishing foamable styrene resin particles containing a composite flame retardant composed of dimethyl-3,4-diphenylhexane are disclosed.
JP-A-9-194623 Japanese Patent Publication No. 61-9432 JP 2006-70202 A JP-A-2005-97555 Japanese Patent Laid-Open No. 9-255879 JP 2004-211042 A

 However, even if the flame retardant and flame retardant aid disclosed in Patent Documents 5 and 6 are simply impregnated into the foam molded article disclosed in Patent Documents 1 to 4, rigidity, foam moldability, chemical resistance In addition, it was impossible to realize a foamed molded article having self-extinguishing properties while maintaining good heat resistance and blackness.

 The present invention has been made in view of the above circumstances, and has improved the drawbacks of both polystyrene-based resin foam molded products and polypropylene-based resin foam molded products, and maintains good rigidity, foam moldability, chemical resistance and heat resistance. On the other hand, an object of the present invention is to provide a self-extinguishing carbon-containing modified polystyrene resin foam molded article having self-extinguishing properties.

In order to achieve the object, the present invention contains 100 parts by mass or more and less than 400 parts by mass of a polystyrene resin with respect to 100 parts by mass of a carbon-containing polypropylene resin, and was measured by ATR infrared spectroscopy. polystyrene type resin ratio of particles center calculated from the absorbance ratio at 698cm ^-1 and 1376cm ^-1 obtained from an infrared absorption spectrum of the particles center _{(D 698 /} D ₁₃₇₆₎ is, relative to a polystyrene-based resin ratio of total particles 1.2 parts or more of carbon-containing modified polystyrene resin particles 100 parts by weight, containing 1.5 parts by weight or more and less than 6 parts by weight of flame retardant and 0.1 parts by weight of flame retardant aid Self-extinguishing carbon-containing modified polystyrene resin particles characterized by containing at least 3 parts by mass and less than 3 parts by mass are provided.

Further, the present invention is the absorbance ratio at 698cm ^-1 and 1376cm ^-1 obtained from an infrared absorption spectrum of the measured particle surface by ATR method infrared spectroscopy _{(D 698 /} D ₁₃₇₆₎ is 0.1 to 2.5 Self-extinguishing carbon-containing modified polystyrene resin particles in the range of

 In the self-extinguishing carbon-containing modified polystyrene resin particles of the present invention, the flame retardant is tri (2,3-dibromopropyl) isocyanate, and the flame retardant aid is 2,3-dimethyl-2,3. -It is preferable to contain 1 type, or 2 or more types selected from the group of diphenylbutane, 3,4-dimethyl-3,4-diphenylhexane, dicumyl peroxide, cumene hydroperoxide.

 The self-extinguishing carbon-containing modified polystyrene resin particles of the present invention preferably contain 1 to 8% by mass of carbon particles.

 The present invention also provides expandable self-extinguishing carbon-containing modified polystyrene resin particles obtained by impregnating the self-extinguishing carbon-containing modified polystyrene resin particles with a foaming agent.

 The present invention also provides self-extinguishing carbon-containing modified polystyrene resin expanded particles obtained by pre-expanding the expandable self-extinguishing carbon-containing modified polystyrene resin particles.

 In addition, the present invention provides a self-extinguishing carbon-containing modified polystyrene resin foam molded article obtained by filling the above-mentioned self-extinguishing carbon-containing modified polystyrene resin foamed particles in a mold and foam-molding.

 Further, in the carbon-containing modified polystyrene-based resin foam molded article of the present invention, the shrinkage in the dimensional change measurement under the condition of a combustion rate of 0 mm / min in accordance with FMVSS 302 and 80 ° C. in accordance with JIS K 6767. The rate is preferably 1.0% or less, and the expansion ratio is preferably 20 to 40 times.

The present invention also includes a step of dispersing 100 parts by mass of carbon-containing polypropylene resin particles, 100 parts by mass or more and less than 400 parts by mass of a styrene monomer, and a polymerization initiator in an aqueous suspension containing a dispersant. When,
Heating the obtained dispersion to a temperature at which the styrenic monomer is not substantially polymerized to impregnate the carbon-containing polypropylene resin particles with the styrenic monomer;
A step of performing the first polymerization of the styrene monomer at a temperature of (T-10) ° C. to (T + 20) ° C. when the melting point of the carbon-containing polypropylene resin particles is T ° C .;
Subsequent to the first polymerization step, a styrene monomer and a polymerization initiator are added, and the temperature is set to (T-25) ° C. to (T + 10) ° C. A step of impregnating the particles with the styrenic monomer and performing a second polymerization;
A self-extinguishing carbon-containing modification characterized by comprising a step of impregnating the resin particles during the second polymerization or the resin particles after the completion of the second polymerization with a flame retardant and a flame retardant aid A method for producing polystyrene-based resin particles is provided.

 In the method for producing self-extinguishing carbon-containing modified polystyrene resin particles of the present invention, the carbon-containing polypropylene resin particles preferably have a melting point of 120 ° C to 145 ° C.

 In the method for producing self-extinguishing carbon-containing modified polystyrene resin particles of the present invention, the carbon-containing polypropylene resin particles are preferably a propylene-ethylene copolymer.

 Further, the present invention is characterized in that the self-extinguishing carbon-containing modified polystyrene resin particles obtained by the production method are impregnated with a foaming agent to obtain foaming self-extinguishing carbon-containing modified polystyrene resin particles. A method for producing foamed self-extinguishing carbon-containing modified polystyrene resin particles is provided.

 The present invention also relates to a self-extinguishing carbon-containing modified polystyrene characterized by heating and pre-foaming foamable self-extinguishing carbon-containing modified polystyrene resin particles obtained by the production method. A method for producing a resin-based resin expanded particle is provided.

 In addition, the present invention fills the mold-mold cavity with the self-extinguishing carbon-containing modified polystyrene resin expanded particles obtained by the method for producing the self-extinguishing carbon-containing modified polystyrene resin expanded particles, Provided is a method for producing a self-extinguishing carbon-containing modified polystyrene-based resin foam molded article characterized by performing an internal foam molding and then releasing the molded article from the mold.

The self-extinguishing carbon-containing modified polystyrene resin particles of the present invention contain 100 parts by mass or more and less than 400 parts by mass of polystyrene resin with respect to 100 parts by mass of the carbon-containing polypropylene resin, and ATR infrared spectroscopy polystyrene type resin ratio of particles center calculated from the absorbance ratio at 698cm ^-1 and 1376cm ^-1 obtained from an infrared absorption spectrum of the measured particle center _{(D 698 /} D ₁₃₇₆₎ by analysis of the entire particles polystyrene The flame retardant is contained in an amount of 1.5 parts by mass or more and less than 6 parts by mass with respect to 100 parts by mass of the carbon-containing modified polystyrene resin particles that are 1.2 times or more of the system resin ratio, and a flame retardant aid. Is contained in an amount of 0.1 part by weight or more and less than 3 parts by weight. Self-extinguishing carbon-containing modified foam obtained by pre-expanding foamed self-extinguishing carbon-containing modified polystyrene resin particles obtained by impregnating the agent and filling the pre-expanded particles in a mold. The high-quality polystyrene-based resin foam molded article takes advantage of each of the polystyrene-based resin foam and the polypropylene-based resin foam molded article while maintaining good rigidity, foam moldability, chemical resistance, heat resistance and blackness. It becomes a foamed molded article having self-extinguishing properties. Therefore, according to the present invention, it is possible to provide self-extinguishing carbon-containing modified polystyrene resin particles suitable for producing a foamed molded article having such excellent physical properties.
The expandable self-extinguishing carbon-containing modified polystyrene resin particles of the present invention are formed by impregnating the above-mentioned self-extinguishing carbon-containing modified polystyrene resin particles with a foaming agent, so that rigidity, foam moldability, chemical resistance It is possible to provide foamable self-extinguishing carbon-containing modified polystyrene resin particles suitable for the production of a foamed article having self-extinguishing properties while maintaining good properties, heat resistance and blackness.
The self-extinguishing carbon-containing modified polystyrene resin foam particles of the present invention are pre-foamed foamed self-extinguishing carbon-containing modified polystyrene resin particles, so that rigidity, foam moldability, chemical resistance Thus, it is possible to provide a self-extinguishing carbon-containing modified polystyrene resin expanded particle suitable for the production of a foamed article having self-extinguishing properties while maintaining good heat resistance and blackness.
Since the self-extinguishing carbon-containing modified polystyrene resin foam molded article of the present invention is obtained by filling the above-described self-extinguishing carbon-containing modified polystyrene resin foamed foam into a mold and performing foam molding, rigidity, foam moldability, A self-extinguishing carbon-containing modified polystyrene resin foam molded article having self-extinguishing properties while maintaining good chemical resistance, heat resistance and blackness can be provided.

In the method for producing self-extinguishing carbon-containing modified polystyrene resin particles of the present invention, 100 parts by mass of carbon-containing polypropylene resin particles and 100 parts by mass or more of styrene monomer in an aqueous suspension containing a dispersant are used. Less than part by mass and a polymerization initiator are dispersed, and the resulting dispersion is heated to a temperature at which the styrenic monomer is not substantially polymerized to convert the styrenic monomer into the carbon-containing polypropylene resin particles. Then, when the melting point of the carbon-containing polypropylene resin particles is T ° C., the first polymerization of the styrene monomer is performed at a temperature of (T−10) ° C. to (T + 20) ° C. Following the first polymerization, a styrene monomer and a polymerization initiator are added, and the second time of the styrene monomer at a temperature of (T-25) ° C. to (T + 10) ° C. Polymerize Particle center portion measured by ATR infrared spectroscopic analysis by impregnating resin particles during second polymerization or resin particles after completion of second polymerization with flame retardant and flame retardant aid The polystyrene resin ratio at the center of the particle calculated from the absorbance ratio (D ₆₉₈ / D ₁₃₇₆ ) at ₆₉₈ cm ⁻¹ and 1376 cm ⁻¹ obtained from the infrared absorption spectrum of ^1. is 1. The flame retardant is contained in an amount of 1.5 parts by mass or more and less than 6 parts by mass with respect to 100 parts by mass of the carbon-containing modified polystyrene resin particles that are 2 times or more, and the flame retardant aid is contained in an amount of 0.1 to 3 parts by mass. Self-extinguishing carbon-containing modified polystyrene resin particles containing less than part by mass can be produced. The obtained self-extinguishing carbon-containing modified polystyrene resin particles are pre-foamed after the foaming self-extinguishing carbon-containing modified polystyrene resin particles obtained by impregnating the foaming agent, and then the pre-foamed particles are molded. When it is filled and foam molded, the advantages of polystyrene resin foam and polypropylene resin foam molded product are utilized to maintain good rigidity, foam moldability, chemical resistance, heat resistance and blackness. However, a self-extinguishing foam molded article was obtained, and according to this production method, self-extinguishing carbon-containing modified polystyrene resin particles suitable for the production of a foam molded article having such excellent physical properties were obtained. Can be provided.
The method for producing the expandable self-extinguishing carbon-containing modified polystyrene resin particles of the present invention is obtained by impregnating the above-mentioned self-extinguishing carbon-containing modified polystyrene resin particles with a foaming agent to modify the expandable self-extinguishing carbon-containing modification. Because it produces polystyrene resin particles, it has a foaming self-extinguishing property that is suitable for manufacturing self-extinguishing foams while maintaining good rigidity, foaming moldability, chemical resistance, heat resistance and blackness. Carbon-containing modified polystyrene resin particles can be provided.
The method for producing a self-extinguishing carbon-containing modified polystyrene resin foamed particle of the present invention is obtained by pre-foaming the above-mentioned foaming self-extinguishing carbon-containing modified polystyrene resin particle to produce a self-extinguishing carbon-containing modified polystyrene resin. Self-extinguishing carbon-containing modification suitable for producing self-extinguishing foams while maintaining good rigidity, foaming moldability, chemical resistance, heat resistance and blackness while producing foamed particles Polystyrene resin expanded particles can be provided.
The method for producing a self-extinguishing carbon-containing modified polystyrene resin foam molded article according to the present invention includes the above-described self-extinguishing carbon-containing modified polystyrene resin foam molded article filled in a mold and subjected to foam molding to contain self-extinguishing carbon. Because it is a modified polystyrene resin foam molded article, it is a self-extinguishing carbon-containing modified polystyrene system that has self-extinguishing properties while maintaining good rigidity, foam moldability, chemical resistance, heat resistance and blackness. A resin foam molding can be provided.

 The inventors of the present invention, as a result of intensive research to achieve the above object, added a styrene monomer to carbon-containing polypropylene resin particles having a specific melting point and containing a specific carbon. By polymerizing in a specific temperature range and then impregnating with a flame retardant and a flame retardant aid, by controlling to a dispersed state where styrene increases in the center of the particle and polypropylene resin increases in the vicinity of the particle surface. It has been found that self-extinguishing carbon-containing modified polystyrene resin particles can be obtained.

 Furthermore, the self-extinguishing carbon-containing modified polystyrene resin particles produced in this way are pre-foamed after the foaming self-extinguishing carbon-containing modified polystyrene resin particles obtained by impregnating the foaming agent. When the mold is filled and foam-molded in the mold, the advantages of each of the polypropylene resin and polystyrene resin are utilized to improve the self-extinguishing carbon content with excellent foam moldability, chemical resistance and heat resistance. The inventors have found that a polystyrene resin foam molded article can be produced, and have completed the present invention.

The self-extinguishing carbon-containing modified polystyrene resin particles of the present invention contain 100 parts by mass or more and less than 400 parts by mass of polystyrene resin with respect to 100 parts by mass of the carbon-containing polypropylene resin, and ATR infrared spectroscopy polystyrene type resin ratio of particles center calculated from the absorbance ratio at 698cm ^-1 and 1376cm ^-1 obtained from an infrared absorption spectrum of the measured particle center _{(D 698 /} D ₁₃₇₆₎ by analysis of the entire particles polystyrene The flame retardant is contained in an amount of 1.5 parts by mass or more and less than 6 parts by mass with respect to 100 parts by mass of the carbon-containing modified polystyrene resin particles that are 1.2 times or more of the system resin ratio, and a flame retardant aid. Is contained in an amount of 0.1 parts by mass or more and less than 3 parts by mass.

 In the self-extinguishing carbon-containing modified polystyrene resin particles of the present invention, the “particle central portion” means from the center of the particle to ¼ of the diameter (particle size) of the particle in a cross section passing through the center of the particle. For example, the particle central portion of a spherical particle having a particle diameter of 1 mm is a portion having a radius of 125 μm from the center of the particle.

 Polypropylene resin, which is one of the resin materials of the self-extinguishing carbon-containing modified polystyrene resin particles of the present invention, is not particularly limited, and a resin obtained by a known polymerization method can be used. A propylene-ethylene copolymer is used. This propylene-ethylene copolymer is mainly composed of a copolymer of ethylene and propylene, but may contain ethylene or another monomer that can be copolymerized with propylene in the molecule. Good. Examples of such a monomer include one or more selected from α-olefins, cyclic olefins, and diene monomers.

 In a preferred embodiment of the present invention, a polypropylene resin having a melting point in the range of 120 ° C. to 145 ° C. is used. When the melting point of the polypropylene resin is lower than 120 ° C., the heat resistance is poor, and the heat resistance of the self-extinguishing carbon-containing modified polystyrene resin foam molded article produced using the self-extinguishing carbon-containing modified polystyrene resin particles. Will be lower. On the other hand, when the melting point is higher than 145 ° C., the polymerization temperature becomes high and good polymerization cannot be performed.

In a preferred embodiment of the present invention, examples of the carbon in the carbon-containing polypropylene resin include furnace black, ketjen black, channel black, thermal black, acetylene black, graphite, and carbon fiber.
The carbon (raw material carbon) before being contained in the polypropylene resin is preferably in the form of particles, and the particle size of the raw material carbon is usually preferably 5 nm to 100 nm, and more preferably 15 nm to 35 nm. . In addition, the particle diameter of raw material carbon means an average particle diameter, and an average particle diameter is an arithmetic average by an electron microscope. The average particle size that characterizes the carbon black used in the present invention is the particle size measured and calculated with an electron micrograph of small spherical components (which have a fine crystal outline and cannot be separated) that constitute the carbon black aggregate. It is the average diameter.

Moreover, it is preferable that 1-8 mass% of carbon is contained in the carbon-containing modified polystyrene resin particle in the self-extinguishing carbon-containing modified polystyrene resin particle of the present invention.
If the blending amount of carbon in the self-extinguishing carbon-containing modified polystyrene resin particles is less than 1% by mass, the resulting foamed molded product cannot exhibit a sufficient black color, which is not preferable. On the other hand, if the amount of carbon exceeds 8% by mass, it is preferable because not only the bulk expansion ratio of the foamed molded product obtained from the self-extinguishing carbon-containing modified polystyrene resin particles is lowered, but also the mechanical strength is lowered. Absent.

The polypropylene resin may contain additives such as an antioxidant, an ultraviolet absorber, a pigment, and a colorant as necessary.
In the self-extinguishing carbon-containing modified polystyrene resin particles of the present invention, the colorant may be an inorganic pigment or an organic pigment.
Examples of inorganic pigments include chromates such as chrome yellow, zinc yellow and barium yellow, ferrocyanides such as bitumen, sulfides such as cadmium yellow and cadmium red, oxides such as iron black and red husk, and ultramarine blue. And silicates such as titanium oxide.
Examples of organic pigments include azo pigments such as monoazo pigments, disazo pigments, azo lakes, condensed azo pigments, chelate azo pigments, phthalocyanine-based, anthraquinone-based, perylene-based, perinone-based, thioindigo-based, quinacridone-based, and dioxazine-based pigments. And polycyclic pigments such as isoindolinone and quinophthalone.

 Examples of the polystyrene resin that is another resin material of the self-extinguishing carbon-containing modified polystyrene resin particles of the present invention include styrene such as styrene, α-methylstyrene, p-methylstyrene, and t-butylstyrene. Examples thereof include resins obtained by polymerizing a system monomer. Furthermore, the polystyrene resin may be a copolymer of a styrene monomer and another monomer copolymerizable with the styrene monomer. Examples of other monomers include polyfunctional monomers such as divinylbenzene, and (meth) acrylic acid alkyl esters that do not contain a benzene ring in the structure such as butyl (meth) acrylate. . You may use these other monomers in the range which does not exceed 5 mass% substantially with respect to a polystyrene-type resin. In the present specification, styrene and a monomer copolymerizable with styrene are also referred to as a styrene monomer.

The polystyrene resin is used in an amount in the range of 100 to 400 parts by mass with respect to 100 parts by mass of the carbon-containing polypropylene resin. The compounding quantity of a preferable polystyrene-type resin is 120-300 mass parts, and 150-250 mass parts is more preferable.
When the ratio of this polystyrene resin is more than 400 parts by mass, the chemical resistance and heat resistance of the foamed molded product obtained by secondary foaming of the pre-expanded particles are not preferable. On the other hand, when the blending amount is less than 100 parts by mass, the rigidity of the foamed molded product obtained by secondary foaming of the pre-foamed particles is unfavorable.

Self-extinguishing carbon-containing modified polystyrene resin particles of the present invention, the absorbance ratio at 698cm ^-1 and 1376cm ^-1 obtained from an infrared absorption spectrum of the particles heart measured by ATR method infrared spectroscopy _{(D 698} / D ₁₃₇₆ ), the ratio of the polystyrene resin at the center of the particle is 1.2 times or more, preferably 1.35 times or more, and particularly preferably 1. 4 times or more.

 When the calculated polystyrene resin ratio in the center of the particle is 1.2 times or less than the polystyrene resin ratio of the whole particle, the gradient of the gradient of the polystyrene resin ratio decreases from the surface layer to the inside. As a result, the expansion ratio and heat resistance of the foamed molded product obtained by foaming the pre-expanded particles are lowered.

Moreover, self-extinguishing carbon-containing modified polystyrene resin particles of the present invention, the absorbance ratio at 698cm ^-1 and 1376cm ^-1 obtained from an infrared absorption spectrum of the measured particle surface by ATR method infrared spectroscopy _{(D 698} / D ₁₃₇₆ ) is preferably in the range of 0.1 to 2.5, more preferably in the range of 0.8 to 2.0, and particularly preferably in the range of 1.0 to 1.5.
The surface of the particle is a “surface layer” including a region from the surface to a depth of several μm.

 When the absorbance ratio is higher than 2.5, the ratio of the polyolefin resin on the surface of the pre-foamed particles is lowered. As a result, the chemical resistance and impact resistance of the foamed molded article obtained by foaming the pre-expanded particles are unfavorable. On the other hand, if the absorbance ratio is lower than 0.1, the dissipation of the foaming agent from the surface of the pre-foamed particles becomes significant, resulting in poor fusion between the particles during molding in the mold, and the impact resistance is reversed. This is not preferable because it tends to be lowered or the finished appearance of the foamed molded product is deteriorated due to shrinkage or the like. In addition, when pre-expanded particles are produced, the time required for the impregnation and polymerization of the styrene monomer into the polyolefin resin particles becomes longer, which is not preferable.

 Here, the ATR (Attenuated Total Reflectance) method infrared spectroscopic analysis in the present invention is an analysis method for measuring an infrared absorption spectrum by a single reflection type ATR method using total reflection absorption (Attenuated Total Reflectance). This analysis method is a method in which an ATR prism having a high refractive index is closely attached to a sample, infrared light is irradiated to the sample through the ATR prism, and the reflected light from the ATR prism is spectrally analyzed.

 ATR infrared spectroscopic analysis is not limited to organic materials such as polymer materials because the spectrum can be measured simply by bringing the sample into close contact with the ATR prism and surface analysis up to a depth of several μm is possible. It is widely used for surface analysis of various substances.

The absorbance D _{698 at 698} cm ⁻¹ obtained from the infrared absorption spectrum refers to the height of a peak appearing in the vicinity of 698 cm ⁻¹ derived from the out-of-plane bending angular vibration of the benzene ring mainly contained in the polystyrene resin.

In addition, the absorbance D _{1376 at 1376} cm ⁻¹ obtained from the infrared absorption spectrum is a peak appearing in the vicinity of 1376 cm ⁻¹ derived from the symmetrical bending vibration of CH ₃ of —C—CH ₃ hydrocarbon contained in the polypropylene resin. Say height.

As a method for obtaining the composition ratio of polystyrene resin and polypropylene resin from the absorbance ratio, a plurality of types of standard samples prepared by uniformly mixing polystyrene resin and polypropylene resin at a predetermined composition ratio are prepared as described below. Then, each standard sample is subjected to particle surface analysis by ATR infrared spectroscopy to obtain an infrared absorption spectrum. The absorbance ratio is calculated from each of the obtained infrared absorption spectra. A calibration curve is drawn by taking the composition ratio (polystyrene resin ratio (mass%) in the standard sample) on the vertical axis and the absorbance ratio (D ₆₉₈ / D ₁₃₇₆ ) on the horizontal axis. Based on this calibration curve, from the absorbance ratio of the self-extinguishing carbon-containing modified polystyrene resin expanded particles of the present invention, the polystyrene resin and the polypropylene resin of the self-extinguishing carbon-containing modified polystyrene resin particles of the present invention The composition ratio can be determined.

For example, when the polypropylene resin is manufactured by Sun Allomer, trade name “PC540R”, and the polystyrene resin is polystyrene (trade name “SS142” manufactured by Sekisui Chemical Co., Ltd.), the composition ratio is obtained by using the calibration curve shown in FIG. Can know. For example, when the absorbance ratio (D ₆₉₈ / D ₁₃₇₆ ) is 10.0, the polypropylene resin is 20.2 mass%, the polystyrene resin is 79.8 mass%, and the absorbance ratio is 15.0, the polypropylene resin. It can be calculated that the resin is 8.1% by mass and the polystyrene resin is 90.9% by mass.
The calibration curve is created by the following method.

The standard sample is obtained by the following method.
First, a total of 2 g of the polystyrene resin and the polypropylene resin are precisely weighed so that the composition ratio (polystyrene resin / polypropylene resin) becomes the following ratio.
This is heated and kneaded in a small injection molding machine under the following conditions and molded into a cylindrical shape having a diameter of 25 mm and a height of 2 mm to obtain a standard sample.
In addition, as a small-sized injection molding machine, what is sold with the brand name "CS-183" from CSI can be used, for example.

Injection molding conditions: heating temperature 200 ° C. to 250 ° C., kneading time 10 minutes Composition ratio (polystyrene resin / polypropylene resin; mass ratio):
0/10, 1/9, 2/8, 3/7, 4/6, 5/5, 6/4, 7/3, 8/2, 9/1, 10/0
The calibration curve of FIG. 1 is obtained by measuring the absorbance ratio of the standard sample of the above ratio and graphing the relationship between the polystyrene resin ratio (mass%) and the absorbance ratio (D ₆₉₈ / D ₁₃₇₆ ).
In FIG. 1, when the polystyrene resin ratio is 40% by mass or less, the calibration curve is approximated by the following equation (1).
Y = −2.5119X ² + 22.966X (1)
In FIG. 1, when the polystyrene resin ratio is 40% by mass or more, the calibration curve is approximated by the following formula (2).
Y = 27.591Ln (X) +16.225 (2)

In the self-extinguishing carbon-containing modified polystyrene resin particles of the present invention, examples of the flame retardant include tri (2,3-dibromopropyl) isocyanate.
The flame retardant is in the range of 1.5 to 6 parts by mass with respect to 100 parts by mass of the carbon-containing modified polystyrene resin particles. The compounding quantity of a preferable flame retardant is 2-5 mass parts, and 3-4 mass parts is more preferable.
When the blending amount of the flame retardant is less than 1.5 parts by mass, the self-extinguishing property of the foamed molded article obtained by secondary foaming of the pre-foamed particles is not preferable. On the other hand, when the blending amount of the flame retardant is more than 6 parts by mass, the change in the heating dimension of the foamed molded product obtained by secondary foaming of the pre-foamed particles is not preferable.

In the self-extinguishing carbon-containing modified polystyrene resin particles of the present invention, as a flame retardant aid, 2,3-dimethyl-2,3-diphenylbutane, 3,4-dimethyl-3,4-diphenylhexane, One type or two or more types selected from the group of organic peroxides of milperoxide and cumene hydroperoxide are exemplified.
The flame retardant assistant is in the range of 0.1 to 3 parts by mass with respect to 100 parts by mass of the carbon-containing modified polystyrene resin particles. The compounding quantity of a preferable flame retardant is 0.5-2.5 mass parts, and 1-2 mass parts is more preferable.
When the blending amount of the flame retardant aid is less than 0.1 parts by mass, the self-extinguishing property of the foamed molded article obtained by secondary foaming of the pre-foamed particles is not preferable. On the other hand, when the blending amount of the flame retardant is more than 3 parts by mass, the change in the heating dimension of the foamed molded product obtained by secondary foaming of the pre-foamed particles is not preferable.

 Further, in the self-extinguishing carbon-containing modified polystyrene resin particles of the present invention, it is preferable that many flame retardants and flame retardant aids are present on the particle surface, but they may be unevenly distributed in the center of the particles. .

The self-extinguishing carbon-containing modified polystyrene resin particles according to the present invention include the following steps (A) to (E), and the self-extinguishing carbon-containing modified polystyrene resin particles according to the present invention are produced. By the method, it can manufacture efficiently and with a sufficient yield.
(A) a step of dispersing 100 parts by mass of carbon-containing polypropylene resin particles, 100 parts by mass or more and less than 400 parts by mass of a styrene monomer, and a polymerization initiator in an aqueous suspension containing a dispersant;
(B) heating the obtained dispersion to a temperature at which the styrenic monomer is not substantially polymerized to impregnate the carbon-containing polypropylene resin particles with the styrenic monomer;
(C) When the melting point of the carbon-containing polypropylene resin particles is T ° C., the step of performing the first polymerization of the styrene monomer at a temperature of (T−10) ° C. to (T + 20) ° C.,
(D) When the styrene monomer and the polymerization initiator are added following the first polymerization step, and the melting point of the carbon-containing polypropylene resin particles is T ° C, (T-25) A step of impregnating the carbon-containing polypropylene resin particles with the styrenic monomer and performing a second polymerization by setting the temperature to from C to (T + 10) ° C.,
(E) A step of impregnating the resin particles during the second polymerization or the resin particles after the completion of the second polymerization with a flame retardant and a flame retardant aid.
In addition, each process of (A)-(E) is a well-known polymerization method such as a suspension polymerization method or a seed polymerization method of a polystyrene resin for producing beaded polystyrene resin particles using a styrene monomer as a raw material. Although it can implement using the autoclave polymerization apparatus etc. which are used when implementing a method, the manufacturing apparatus to be used is not limited to this.

In the step (A), for example, the carbon-containing polypropylene-based resin particles are obtained by melting the carbon-containing polypropylene-based resin with an extruder and granulating the pellets by strand cutting, underwater cutting, hot cutting, or the like. It can be obtained by directly pulverizing and pelletizing resin particles. In addition, examples of the shape include a true spherical shape, an elliptical spherical shape (egg shape), a cylindrical shape, and a prismatic shape. The preferable resin particle size of the carbon-containing polypropylene resin particles is in the range of 0.5 mm to 1.5 mm, more preferably in the range of 0.6 mm to 1.0 mm.
In the step (A), as the carbon-containing polypropylene resin, those having a melting point of 120 ° C. to 145 ° C. are suitable.

 Examples of the dispersant used in the step (A) include organic dispersants such as partially saponified polyvinyl alcohol, polyacrylate, polyvinyl pyrrolidone, carboxymethyl cellulose, and methyl cellulose, magnesium pyrophosphate, calcium pyrophosphate, calcium phosphate, and carbonic acid. Examples thereof include inorganic dispersants such as calcium, magnesium phosphate, magnesium carbonate, and magnesium oxide. Of these, inorganic dispersants are preferred. When using an inorganic dispersant, it is preferable to use a surfactant in combination. Examples of such a surfactant include sodium dodecylbenzene sulfonate and α-olefin sulfonic acid sodium.

 Moreover, as a polymerization initiator, a conventionally well-known polymerization initiator widely used for polymerization of styrene monomers can be used. For example, benzoyl peroxide, lauroyl peroxide, t-amyl peroxy octoate, t-butyl peroxybenzoate, t-amyl peroxybenzoate, t-butyl peroxybivalate, t-butyl peroxyisopropyl carbonate, t- Butyl peroxyacetate, t-butylperoxy-3,3,5-trimethylcyclohexanoate, di-t-butylperoxyhexahydroterephthalate, 2,2-di-t-butylperoxybutane, dicumyl peroxide And azo compounds such as azobisisobutyronitrile and azobisdimethylvaleronitrile. In addition, a polymerization initiator may be used independently or may be used together.

 In addition, when adding a crosslinking agent, for example, a method of directly adding the crosslinking agent to the carbon-containing polypropylene resin, or after dissolving the crosslinking agent in a solvent, a plasticizer or a styrene monomer. The method of adding, the method of adding after dispersing a crosslinking agent in water, etc. are mentioned. Among these, a method of adding a crosslinking agent after dissolving it in a styrene monomer is preferable.

 The styrenic monomer can be continuously or intermittently added to the aqueous medium in order to impregnate the carbon-containing polypropylene resin particles. The styrenic monomer is preferably added gradually to the aqueous medium. Examples of the aqueous medium include water and a mixed medium of water and a water-soluble medium (for example, alcohol).

In the step (B), the dispersion obtained in the step (A) is heated to a temperature at which the styrene monomer is not substantially polymerized, and the carbon-containing polypropylene resin particles are impregnated with the styrene monomer. The temperature at that time is in the range of 45 ° C to 70 ° C, preferably in the range of 50 ° C to 65 ° C.
When the impregnation temperature is less than the above range, the impregnation of the styrene monomer is insufficient and a polymerized polystyrene powder is generated, which is not preferable. On the other hand, if the impregnation temperature exceeds the above range, it is not preferable because the styrene monomer is polymerized before the carbon-containing polypropylene resin particles are sufficiently impregnated.

In the steps (C) and (D), the polymerization temperature is an important factor. When the melting point of the carbon-containing polypropylene resin is T ° C., in the step (C) (first polymerization), (T The temperature range is −10) ° C. to (T + 20) ° C., and in the step (D) (second polymerization), the temperature range is (T−25) ° C. to (T + 10) ° C.
By carrying out the polymerization in the temperature range, the resin particle central part has a large amount of polystyrene resin (that is, a large amount of carbon-containing polypropylene resin in the surface layer), and as a result, the polypropylene resin and polystyrene. The carbon-containing modified polystyrene resin particles having self-extinguishing properties while maintaining good rigidity, foam moldability, chemical resistance, heat resistance and blackness while taking advantage of each advantage of the resin. it can.
When the polymerization temperature is lower than the above temperature range, the abundance of the polystyrene-based resin is small at the center of the obtained resin particles, and resin particles and foamed molded articles exhibiting good physical properties cannot be obtained. In addition, when the polymerization temperature is higher than the above temperature range, the polymerization starts before the styrene monomer is sufficiently impregnated with the carbon-containing polypropylene resin particles, so that the resin particles and the foam molded article exhibiting good physical properties. Cannot be obtained. In addition, an expensive polymerization facility with excellent heat resistance is required.

 In addition, the step of polymerizing the styrene monomer impregnated in the carbon-containing polypropylene resin particles is divided into two steps, (C) step (first polymerization) and (D) step (second polymerization). The reason for the division is that if a carbon-containing polypropylene resin is impregnated with many styrene monomers at once, the styrene monomer is not sufficiently impregnated in the carbon-containing polypropylene resin, and the carbon-containing polypropylene resin This is because it remains on the surface. Therefore, as in the method for producing the modified polystyrene resin particles according to the present invention, the styrene monomer is surely obtained in the step (C) by dividing into the two steps of the step (C) and the step (D). The styrene monomer is impregnated toward the center of the carbon-containing polypropylene resin in the step (D) as well.

 In the step (E), the temperature at which the resin particles during the second polymerization or the resin particles after the completion of the second polymerization are impregnated with a flame retardant and a flame retardant assistant is different from that of the flame retardant. The temperature at the time of charging the flame retardant is in the range of 30 ° C. to 90 ° C., preferably in the range of 50 ° C. to 70 ° C., and the temperature after adding the flame retardant and the flame retardant aid A temperature range of t ° C. to (t + 30) ° C. is preferable when the higher melting point of the auxiliary agent is defined as t ° C. If the temperature is lower than t ° C, the modified polystyrene resin particles may not be sufficiently impregnated with the flame retardant or the flame retardant aid. If the temperature is higher than (t + 30) ° C, an expensive polymerization facility excellent in heat resistance is required.

After performing the polymerization in the step (E), the reaction vessel is cooled, and the formed self-extinguishing carbon-containing modified polystyrene resin particles are separated from the aqueous medium, so that 100 parts by mass of the carbon-containing polypropylene resin is obtained. in contrast, a polystyrene resin containing less than 400 parts by mass or more to 100 parts by mass, and the absorbance ratio at 698cm ^-1 and 1376cm ^-1 obtained from an infrared absorption spectrum of the particles heart measured by ATR method infrared spectroscopy In 100 parts by mass of the carbon-containing modified polystyrene resin particles in which the polystyrene resin ratio in the center part of the particle calculated from (D ₆₉₈ / D ₁₃₇₆ ) is 1.2 times or more with respect to the polystyrene resin ratio of the entire particle. On the other hand, the flame retardant is contained in an amount of 1.5 parts by mass or more and less than 6 parts by mass, and the flame retardant aid is contained in an amount of 0.1 to 3 parts by mass. Self-extinguishing carbon-containing modified polystyrene resin particles is obtained which contains less than.

The method for producing a self-extinguishing carbon-containing modified polystyrene resin particle according to the present invention comprises dispersing a carbon-containing polypropylene resin particle, a styrene monomer, and a polymerization initiator in an aqueous suspension containing a dispersant. After impregnating the carbon-containing polypropylene resin particles with the styrene monomer, the first stage at a temperature of (T-25) ° C. to (T + 10) ° C. when the melting point of the polypropylene resin particles is T ° C. Next, the second stage polymerization is performed at a temperature of (T−25) ° C. to (T + 10) ° C., and the resin particles during the second polymerization, or the resin particles after the completion of the second polymerization, By impregnating the flame retardant and the flame retardant aid, 698 cm ⁻¹ obtained from the infrared absorption spectrum at the center of the particle measured by ATR infrared spectroscopy in the carbon-containing polypropylene resin particles and The polystyrene-containing resin ratio at the center of the particle calculated from the absorbance ratio at ₁₃₇₆ cm ⁻¹ (D ₆₉₈ / D ₁₃₇₆ ) is 1.2 times or more the polystyrene-based resin ratio of the entire particle. Self-extinguishing carbon-containing modified polystyrene resin particles obtained by impregnating a resin resin particle with a flame retardant and a flame retardant aid can be produced. The obtained self-extinguishing carbon-containing modified polystyrene resin particles are obtained by pre-expanding the foamable resin particles obtained by impregnating the foaming agent, and then filling the foamed particles into a mold and performing in-mold foam molding. Suitable for the production of molded products with self-extinguishing properties while maintaining good rigidity, foam moldability, chemical resistance, heat resistance and blackness, taking advantage of each advantage of polypropylene resin and polystyrene resin Self-extinguishing carbon-containing modified polystyrene resin particles can be provided.

 The present invention relates to a foamable self-extinguishing carbon-containing modified polystyrene resin particle obtained by impregnating the above-mentioned self-extinguishing carbon-containing modified polystyrene resin particle with a foaming agent, preferably a readily volatile foaming agent, and its A manufacturing method is provided.

 As the readily volatile foaming agent impregnated into the self-extinguishing carbon-containing modified polystyrene resin particles, those having a boiling point equal to or lower than the softening temperature of the polymer and easily volatile, such as propane, n-butane and i-butane , N-pentane, i-pentane, cyclopentane, carbon dioxide gas, and nitrogen, and these blowing agents can be used alone or in combination of two or more. The amount of the readily volatile foaming agent used is preferably in the range of 5 to 25 parts by mass with respect to 100 parts by mass of the self-extinguishing carbon-containing modified polystyrene resin particles.

 Furthermore, you may use a foaming adjuvant with a foaming agent. Examples of such foaming aids include solvents such as toluene, xylene, ethylbenzene, cyclohexane, D-limonene, and plasticizers (high boiling solvents) such as diisobutyl adipate, diacetylated monolaurate, and palm oil. . In addition, as addition amount of a foaming adjuvant, 0.1-2.5 mass parts is preferable with respect to 100 mass parts of self-extinguishing carbon containing modified polystyrene resin particles.

 Further, surface treatment agents such as a binding inhibitor, a fusion accelerator, an antistatic agent, and a spreading agent may be added to the foamable self-extinguishing carbon-containing modified polystyrene resin particles.

 The anti-bonding agent serves to prevent the pre-expanded particles from being bonded to each other when the expandable self-extinguishing carbon-containing modified polystyrene resin particles are pre-expanded. Here, coalescence means that a plurality of pre-expanded particles are united and integrated. Specific examples include talc, calcium carbonate, zinc stearate, aluminum hydroxide, ethylene bis stearamide, tricalcium phosphate, dimethylpolysiloxane, and the like.

The fusion accelerator plays a role of promoting fusion between the pre-foamed particles when the pre-foamed particles are subjected to secondary foam molding. Specific examples include stearic acid, stearic acid triglyceride, hydroxystearic acid triglyceride, sorbitan stearate, and the like.
Examples of the antistatic agent include polyoxyethylene alkylphenol ether and stearic acid monoglyceride. Examples of the spreading agent include polybutene, polyethylene glycol, and silicone oil. In addition, as for the total addition amount of the said surface treating agent, 0.01-2.0 mass parts is preferable with respect to 100 mass parts of modified polystyrene resin particles.

 The method of impregnating the self-extinguishing carbon-containing modified polystyrene resin particles with the foaming agent can be appropriately changed according to the type of the foaming agent. For example, a method of press-fitting a foaming agent into an aqueous medium in which self-extinguishing carbon-containing modified polystyrene resin particles are dispersed, and impregnating the foaming agent into the resin, self-extinguishing carbon-containing modified polystyrene resin Examples thereof include a method in which the particles are supplied to a rotary mixer, a foaming agent is press-fitted into the rotary mixer, and the resin particles are impregnated with the foaming agent. The temperature at which the self-extinguishing carbon-containing modified polystyrene resin particles are impregnated with the foaming agent is usually preferably 50 ° C to 140 ° C.

 The expandable self-extinguishing carbon-containing modified polystyrene resin particles of the present invention are obtained by impregnating the above-mentioned self-extinguishing carbon-containing modified polystyrene resin particles with a foaming agent, so that rigidity, foam moldability, chemical resistance It is possible to provide foamable self-extinguishing carbon-containing modified polystyrene resin particles suitable for the production of a foamed article having self-extinguishing properties while maintaining good properties, heat resistance and blackness.

The present invention is directed to self-extinguishing carbon-containing modified polystyrene resin foam particles (hereinafter referred to as pre-foamed particles) obtained by heating and pre-foaming the above-mentioned expandable self-extinguishing carbon-containing modified polystyrene resin particles. And its manufacturing method.
The pre-foaming heating conditions and the apparatus used for the pre-foaming can be the same as those for the production of conventional polystyrene resin pre-foamed particles. For example, the expandable carbon-containing modified polystyrene resin particles are heated in an atmosphere having a water vapor pressure of about 0.5 to 4.0 kg / cm ² G (about 0.05 to 0.4 MPa) in a pre-foaming apparatus. Can be obtained by: The heating time is generally about 20 to 120 seconds.

The pre-expanded particles usually have a bulk density of 0.0166 to 0.2 g / cm ³ . A preferred bulk density is 0.02 to 0.1 g / cm ³ . A more preferable bulk density is 0.025 to 0.05 g / cm ³ . If the bulk density is less than 0.0166 g / cm ³ , the strength of the foamed molded product obtained by foaming the pre-foamed particles is unfavorable. On the other hand, if the bulk density is greater than 0.2 g / cm ³ , the mass of the foamed molded article obtained by foaming the pre-foamed particles is not preferable.
Moreover, when this bulk density is expressed by a bulk foaming factor, it is bulk foaming factor (times) = 1 / bulk density (g / cm ³ ), so that this pre-expanded particle has a bulk foaming factor of 5 to 60 (times). The preferred bulk foaming factor is 10 to 50 (times), and the more preferred bulk foaming factor is 20 to 40 (times).

 The form of the pre-expanded particles is not particularly limited as long as it does not affect the subsequent in-mold foam molding. For example, a true spherical shape, an elliptical spherical shape (egg shape), a cylindrical shape, a prismatic shape and the like can be mentioned. Of these, a true spherical shape and an elliptical spherical shape, which can be easily filled into the cavity of the mold, are preferable.

 The pre-expanded particles may contain an additive. Additives include foaming nucleating agents such as talc, calcium silicate, ethylenebisstearic acid amide, methacrylic acid ester copolymers, fillers such as synthetic or naturally produced silicon dioxide, diisobutyl adipate, liquid paraffin, glycerin Examples thereof include plasticizers such as diacetomonolaurate and coconut oil, colorants such as carbon black and graphite, ultraviolet absorbers and antioxidants.

 Since the pre-expanded particles of the present invention are obtained by pre-expanding the above-mentioned expandable self-extinguishing carbon-containing modified polystyrene resin particles, the rigidity, foam moldability, chemical resistance, heat resistance and blackness are improved. Pre-expanded particles suitable for producing a foamed molded article having self-extinguishing properties while being held can be provided.

The present invention provides a self-extinguishing carbon-containing modified polystyrene resin foam molded article (hereinafter referred to as a foam molded article) obtained by in-mold foam molding of the above-mentioned pre-expanded particles and a method for producing the same.
In order to make the above-mentioned pre-expanded particles into a foam-molded product, the above-mentioned pre-expanded particles are usually held for about 24 hours and aged, and then the pre-expanded particles are filled into the mold cavity and heated to heat the mold A foam-molded article having a desired shape can be obtained by foam-molding and fusing and pre-expanding particles together. This in-mold foam molding can be performed, for example, by introducing water vapor having a vapor pressure of about 0.5 to 4.5 kg / cm ² G (about 0.05 to 0.45 MPa) into the mold.

In addition, the foamed molded article of the present invention has a burning rate of 0 mm / min in accordance with FMVSS 302, and a shrinkage ratio of 1.0% or less in a dimensional change measurement under conditions of 80 ° C. in accordance with JIS K 6767. It is preferable that When the shrinkage rate exceeds 1.0%, the dimensional stability is not preferable.
In addition, since shrinkage | contraction rate is so preferable that it is small, it is not necessary to provide the lower limit in particular. For example, it is desirable that the lower limit value of the shrinkage rate is zero.

The foamed molded product of the present invention usually has a density of 0.0166 to 0.2 g / cm ³ . Preferably, the density is in the range of 0.02~0.1g / cm ^3, more preferably, the density is in the range of 0.025~0.05g / cm ^3.
If the density of the foamed molded product is less than 0.0166 g / cm ³ , the strength of the foamed molded product obtained by foaming the pre-expanded particles is not preferable. On the other hand, if the density of the foamed molded product is larger than 0.2 g / cm ³ , the mass of the foamed molded product obtained by foaming the pre-expanded particles is not preferable. In addition, when this density is expressed in terms of expansion ratio, since expansion ratio (times) = 1 / density (g / cm ³ ), this foamed molded article has a expansion ratio of 5 to 60 (times), which is preferable. The expansion ratio is 10 to 50 (times), and a more preferable expansion ratio is 20 to 40 (times).

Furthermore, the foamed molded product of the present invention has a foaming factor in the range of 5 to 60 times, and preferably a foaming factor in the range of 10 to 50 times. More preferably, the expansion ratio is in the range of 20 to 40 times.
When the expansion ratio of the foamed molded product is less than 5 times, the mass of the foamed molded product obtained by foaming the pre-expanded particles is not preferable. On the other hand, when the expansion ratio of the foamed molded product is larger than 60 times, the strength of the foamed molded product obtained by foaming the pre-expanded particles is not preferable.

 Since the foam-molded article of the present invention is obtained by in-mold foam-molding the above-mentioned carbon-containing modified polystyrene resin foam particles, it has excellent rigidity, foam-moldability, chemical resistance, heat resistance, blackness and self-extinguishing properties. A foamed molded article can be provided.

 The foamed molded product obtained as described above can be used for various purposes such as vehicle bumper core materials, vehicle cushioning materials such as door interior cushioning materials, electronic parts, various industrial materials, and food containers. it can.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, the measuring method of melting | fusing point, bulk density, a heating dimensional change rate, chemical resistance, and an absorbance ratio in the following Examples is described below.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, the measuring method of melting | fusing point, a bulk density, a heating dimensional change rate, chemical resistance, a burning rate, and an absorbance ratio in the following Examples is described below.

<Melting point>
Measured by the method described in JIS K7122: 1987 "Method for measuring the transition heat of plastic". That is, using a differential scanning calorimeter DSC220 type (manufactured by Seiko Denshi Kogyo Co., Ltd.), 7 mg of a sample was filled in a measurement container, and a nitrogen gas flow rate of 30 ml / min was used at a temperature between room temperature and 220 ° C. to 10 ° C./min. The temperature was raised, lowered, and raised repeatedly at the speed of raising and lowering the temperature, and the melting peak temperature of the DSC curve at the second temperature raising was defined as the melting point. When there were two or more melting peaks, the lower peak temperature was taken as the melting point.

<Bulk density>
The bulk density of the pre-expanded particles was measured as follows.
First, pre-expanded particles were filled up to 500 cm ^{3 and} a graduation of 500 cm ^{3 in} a measuring cylinder. When the graduated cylinder was visually observed from the horizontal direction and any pre-expanded particles reached the scale of 500 cm ³ , the filling of the pre-expanded particles into the graduated cylinder was terminated at that point.
Next, the mass of the pre-expanded particles filled in the measuring cylinder was weighed with two significant figures after the decimal point, and the mass was defined as W (g).
And the bulk density of the pre-expanded particles was calculated by the following formula.
Bulk density (g / cm ³ ) = W / 500

<Bulk foam multiple>
The bulk expansion ratio of the pre-expanded particles was calculated by the following formula.
Bulk foam multiple (times) = 1 / density (g / cm ³ )

<Density>
The density of the foamed molded product was measured as follows.
It was measured by the method described in JIS K7122: 1999 “Foamed Plastics and Rubbers—Measurement of Apparent Density”.
A test piece of 50 cm ³ or more (100 cm ³ or more in the case of semi-rigid and soft materials) was cut so as not to change the original cell structure of the material, its mass was measured, and calculated by the following formula.
Density (g / cm ³ ) = Test piece mass (g) / Test piece volume (cm ³ )
Test specimen condition adjustment and measurement specimens were cut from a sample that had passed 72 hours or more after molding, and were subjected to atmospheric conditions of 23 ° C ± 2 ° C x 50% ± 5% or 27 ° C ± 2 ° C x 65% ± 5%. It has been left for more than an hour.

<Foaming multiple>
The expansion ratio of the foamed molded product was calculated by the following formula.
Foaming multiple (times) = 1 / density (g / cm ³ )

<Heating dimensional change rate>
The heating dimensional change rate was measured by the B method described in JIS K 6767: 1999K “foamed plastic-polyethylene test method”.
The test piece is 150 x 150 x original thickness (mm), and three straight lines are written in the center part in parallel with each other in the vertical and horizontal directions at intervals of 50 mm, inside a hot air circulating dryer at 80 ° C. The sample was taken out after 168 hours and left in a standard state for 1 hour, and the vertical and horizontal line dimensions were measured by the following formulas.
S = (L ₁ −L ₀ ) / L ₀ × 100
In the formula, S represents a heating dimensional change rate (%), L ₁ represents an average dimension (mm) after heating, and L ₀ represents an initial average dimension (mm).
The heating dimensional change rate S was evaluated according to the following criteria.
A: 0 ≦ S <1; the rate of dimensional change was low, and the dimensional stability was good.
X: S ≧ 1; dimensional change was remarkably large, and practical use was impossible.

<Chemical resistance>
A flat rectangular plate-shaped test piece having a length of 100 mm, a width of 100 mm, and a thickness of 20 mm was cut out from the foamed molded article and allowed to stand at 23 ° C. and a humidity of 50% for 24 hours. The test piece was cut out from the foam molded body so that the entire upper surface of the test piece was formed from the surface of the foam molded body.
Next, 1 g of gasoline as a chemical was uniformly applied and left for 60 minutes at 23 ° C. and 50% humidity.
Then, the chemical | medical agent was wiped off from the upper surface of the test piece, the upper surface of the test piece was observed visually, and it judged based on the following reference | standard.
○: Good No change △: Slightly bad Surface softening ×: Bad Surface depression (shrinkage)

<Burning rate>
The burning rate was measured by a method in accordance with US automobile safety standard FMVSS 302.
The test piece had a bulk foaming factor of 30 times, 350 mm × 100 mm × 12 mm (thickness), and had skins on at least two sides of 350 mm × 100 mm.
The burning rate was evaluated according to the following criteria.
○: In a foamed molded article having a bulk foaming ratio of 30 times, when extinguishing before reaching the measurement start point. In this case, the combustion speed is set to 0 mm / min.
X: When the combustion rate is larger than 0 mm / min in a foamed molded article having a bulk expansion ratio of 30 times.

<Absorbance ratio of the particle center or surface layer and polystyrene resin ratio>
The absorbance ratio (D ₆₉₈ / D ₁₃₇₆ ) was measured as follows.
That is, an infrared absorption spectrum was obtained by performing ATR infrared spectroscopic analysis on the particle central part or surface of each of 10 randomly selected pre-expanded particles.
Here, in the measurement of the particle center, each pre-expanded particle is divided into two equal parts (for example, pre-expanded particles having a particle size of 5 mm are cut into 2.5 ± 0.5 mm), and the center of the cut surface ( The measurement was performed with the ATR prism in close contact with the inner side of the circle (at least 1/4 of the center of the circle).
In the measurement of the surface, the ATR prism is closely attached to the surface of each pre-expanded particle.
The absorbance ratio (D ₆₉₈ / D ₁₃₇₆ ) was calculated from each infrared absorption spectrum, and the minimum absorbance ratio and the maximum absorbance ratio were excluded. The arithmetic average of the remaining 8 absorbance ratios was defined as the absorbance ratio (D ₆₉₈ / D ₁₃₇₆ ). The absorbance ratio (D ₆₉₈ / D ₁₃₇₆ ) was measured using, for example, a measurement apparatus sold under the trade name “Fourier Transform Infrared Spectrophotometer MAGMA 560” from Nicolet (current company name: Thermofisher). .
The polystyrene resin ratio (% by mass) was calculated from the absorbance ratio (D ₆₉₈ / D ₁₃₇₆ ) based on the calibration curve described above.

<Absorbance ratio of whole particles and polystyrene resin ratio>
The absorbance ratio (D ₆₉₈ / D ₁₃₇₆ ) was measured as follows.
That is, the pre-expanded particles were heated and reduced at a heating temperature of 200 ° C. to 250 ° C., cooled and pulverized, and 2 g of the pulverized product was precisely weighed.
This pulverized product was heated and kneaded under the following conditions with a small injection molding machine, and formed into a cylindrical shape having a diameter of 25 mm and a height of 2 mm to obtain a measurement sample.
As the small injection molding machine, for example, a machine sold by CSI under the trade name “CS-183” was used.
Injection molding conditions: heating temperature 200 ° C. to 250 ° C., kneading time 10 minutes The surface of the measurement sample was subjected to ATR infrared spectroscopy to obtain an infrared absorption spectrum.
The absorbance ratio (D ₆₉₈ / D ₁₃₇₆ ) was calculated from each infrared absorption spectrum. The absorbance ratio (D ₆₉₈ / D ₁₃₇₆ ) was measured using, for example, a measurement apparatus sold under the trade name “Fourier Transform Infrared Spectrophotometer MAGMA 560” from Nicolet (current company name: Thermofisher). .
The polystyrene resin ratio (% by mass) was calculated from the absorbance ratio (D ₆₉₈ / D ₁₃₇₆ ) based on the calibration curve described above.

[Example 1]
1880 g of a polypropylene resin (manufactured by Prime Polymer, trade name “F-744NP”, melting point: 140 ° C.) and 120 g of furnace black (trade name “# 650B”, manufactured by Mitsubishi Chemical Corporation) are mixed, and this mixture is extruded. , Melt-kneaded and granulated into pellets by strand cutting to obtain spherical (egg-like) carbon-containing polypropylene resin particles containing 6% by mass of furnace black in polypropylene resin.
The carbon-containing polypropylene resin particles at this time were adjusted to 80 mmg per 100 particles and an average particle diameter of about 1 mm.
Next, 600 g of the carbon-containing polypropylene-based resin particles are put into a 5 L autoclave with a stirrer, and 2 kg of pure water, 20 g of magnesium pyrophosphate, and 0.5 g of sodium dodecylbenzenesulfonate are added as an aqueous medium, and the resulting mixture is stirred into the aqueous medium. Suspended and held for 10 minutes, then heated to 60 ° C. to obtain an aqueous suspension.
Next, 300 g of a styrene monomer in which 0.6 g of dicumyl peroxide was dissolved in this suspension was dropped in 30 minutes. After dropping, the mixture was held for 30 minutes, and the styrene monomer was absorbed by the carbon-containing polypropylene resin particles.
Next, the temperature of the reaction system is raised to 135 ° C., which is 5 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and maintained for 2 hours to polymerize the styrene monomer in the carbon-containing polypropylene resin particles (first Polymerization).
Next, the reaction liquid of the first polymerization is set to 120 ° C., which is 20 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and 1.5 g of sodium dodecylbenzenesulfonate is added to this suspension, and then the polymerization is started. As an agent, 1100 g of a styrene monomer in which 4.2 g of dicumyl peroxide was dissolved was dropped over 5 hours and 30 minutes, and polymerization (second polymerization) was performed while absorbing the carbon-containing polypropylene resin particles.
After completion of the dropping, the mixture was held at 120 ° C. for 1 hour, then heated to 140 ° C. and held for 3 hours to complete the polymerization, thereby obtaining carbon-containing modified polystyrene resin particles.
Thereafter, the temperature of the reaction system was set to 60 ° C., and 40 g of tri (2,3-dibromopropyl) isocyanate (manufactured by Nippon Kasei Co., Ltd.) and 2,3-dimethyl-2,3-diphenylbutane were added to this suspension. 20 g (manufactured by Kayaku Akzo) was added. After the addition, the temperature of the reaction system was raised to 140 ° C., and stirring was continued for 4 hours to obtain self-extinguishing carbon-containing modified polystyrene resin particles.
Next, it was cooled to room temperature, and the resin particles were taken out from the 5 L autoclave. After taking out, 2 kg of self-extinguishing carbon-containing modified polystyrene resin particles and 2 L of water were again put into a 5 L autoclave with a stirrer, and 300 g of butane as a blowing agent was injected into a 5 L autoclave with a stirrer. After the injection, the temperature was raised to 70 ° C. and stirring was continued for 4 hours.
Then, it cooled to normal temperature, took out from the 5L autoclave, and after dehydrating and drying, the expandable self-extinguishing carbon containing modified polystyrene resin particle was obtained.
Next, the obtained expandable self-extinguishing carbon-containing modified polystyrene resin particles were pre-expanded to a bulk expansion ratio of 30 times to obtain self-extinguishing carbon-containing modified polystyrene resin expanded particles.
And the absorbance was measured using the obtained self-extinguishing carbon-containing modified polystyrene resin expanded particles, and the polystyrene resin ratio was calculated.
The obtained self-extinguishing carbon-containing modified polystyrene resin foamed particles are allowed to stand at room temperature for 1 day, and then filled in the cavity of a mold having a size of 400 mm × 300 mm × 50 mm. Then, 0.20 MPa of water vapor was introduced for 50 seconds and heated, and then cooled until the maximum surface pressure of the foamed molded product decreased to 0.001 MPa to obtain a foamed molded product. Under these molding conditions, a foamed molded article having good appearance and fusion was obtained.
Then, using the obtained self-extinguishing carbon-containing modified polystyrene resin foam molded article, the expansion ratio, the heating dimensional change rate, the chemical resistance, and the burning rate were measured.

[Example 2]
1940 g of polypropylene resin (manufactured by Prime Polymer, trade name “F-744NP”, melting point: 140 ° C.) and 60 g of furnace black (trade name “# 650B”, manufactured by Mitsubishi Chemical Corporation) are mixed, and this mixture is extruded. , Melt-kneaded and granulated into pellets by strand cutting to obtain spherical (egg-like) carbon-containing polypropylene resin particles containing 3% by mass of furnace black in polypropylene resin.
The carbon-containing polypropylene resin particles at this time were adjusted to 80 mmg per 100 particles and an average particle diameter of about 1 mm.
Next, 800 g of the carbon-containing polypropylene resin particles are put into a 5 L autoclave equipped with a stirrer, and 2 kg of pure water, 20 g of magnesium pyrophosphate, and 0.5 g of sodium dodecylbenzenesulfonate are added as an aqueous medium, and the resulting mixture is stirred into the aqueous medium. Suspended and held for 10 minutes, then heated to 60 ° C. to obtain an aqueous suspension.
Next, 400 g of a styrene monomer in which 0.8 g of dicumyl peroxide was dissolved in this suspension was dropped in 30 minutes. After dropping, the mixture was held for 30 minutes, and the styrene monomer was absorbed by the carbon-containing polypropylene resin particles.
Next, the temperature of the reaction system is raised to 135 ° C., which is 5 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and maintained for 2 hours to polymerize the styrene monomer in the carbon-containing polypropylene resin particles (first Polymerization).
Next, the reaction liquid of the first polymerization is set to 120 ° C., which is 20 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and 1.5 g of sodium dodecylbenzenesulfonate is added to this suspension, and then the polymerization is started. As an agent, 800 g of styrene monomer in which 3.6 g of dicumyl peroxide (manufactured by NOF Corporation) is dissolved is dropped over 4 hours, and polymerization (second polymerization) is performed while absorbing the carbon-containing polypropylene resin particles. Except that, self-extinguishing carbon-containing modified polystyrene resin expanded particles were obtained in the same manner as in Example 1.
And the absorbance was measured using the obtained self-extinguishing carbon-containing modified polystyrene resin expanded particles, and the polystyrene resin ratio was calculated.
Further, using the obtained self-extinguishing carbon-containing modified polystyrene resin foamed particles, a self-extinguishing carbon-containing modified polystyrene resin foamed molded article was obtained in the same manner as in Example 1.
Then, using the obtained self-extinguishing carbon-containing modified polystyrene resin foam molded article, the expansion ratio, the heating dimensional change rate, the chemical resistance, and the burning rate were measured.

[Example 3]
1880 g of a polypropylene resin (manufactured by Prime Polymer, trade name “F-744NP”, melting point: 140 ° C.) and 120 g of furnace black (trade name “# 650B”, manufactured by Mitsubishi Chemical Corporation) are mixed, and this mixture is extruded. , Melt-kneaded and granulated into pellets by strand cutting to obtain spherical (egg-like) carbon-containing polypropylene resin particles containing 6% by mass of furnace black in polypropylene resin.
The carbon-containing polypropylene resin particles at this time were adjusted to 80 mmg per 100 particles and an average particle diameter of about 1 mm.
Next, 1000 g of the carbon-containing polypropylene resin particles are put into a 5 L autoclave equipped with a stirrer, and 2 kg of pure water, 20 g of magnesium pyrophosphate, and 0.5 g of sodium dodecylbenzenesulfonate are added as an aqueous medium, and the resulting mixture is stirred into the aqueous medium. Suspended and held for 10 minutes, and then heated to 60 ° C. to obtain an aqueous suspension.
Next, 500 g of a styrene monomer in which 1.0 g of dicumyl peroxide was dissolved in this suspension was dropped in 30 minutes. After dropping, the mixture was held for 30 minutes, and the styrene monomer was absorbed by the carbon-containing polypropylene resin particles.
Next, the temperature of the reaction system is raised to 135 ° C., which is 5 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and maintained for 2 hours to polymerize the styrene monomer in the carbon-containing polypropylene resin particles (first Polymerization).
Next, the reaction liquid of the first polymerization is set to 120 ° C., which is 20 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and 1.5 g of sodium dodecylbenzenesulfonate is added to this suspension, and then the polymerization is started. 500 g of a styrene monomer in which 3 g of dicumyl peroxide was dissolved as an agent was dropped over 2 hours and 30 minutes, and polymerization (second polymerization) was carried out while absorbing the carbon-containing polypropylene resin particles.
After completion of the dropping, the mixture was held at 120 ° C. for 1 hour, then heated to 140 ° C. and held for 3 hours to complete the polymerization, thereby obtaining carbon-containing modified polystyrene resin particles.
Thereafter, the temperature of the reaction system was set to 60 ° C., and 100 g of tri (2,3-dibromopropyl) isocyanate (manufactured by Nippon Kasei Co., Ltd.) and 2,3-dimethyl-2,3-diphenylbutane were added to this suspension. 40g (made by Kayaku Akzo Co., Ltd.) was charged. After the charging, the temperature of the reaction system was raised to 140 ° C, and the stirring was continued for 4 hours to obtain self-extinguishing carbon-containing modified polystyrene resin particles. In the same manner as in Example 1, self-extinguishing carbon-containing modified polystyrene resin expanded particles were obtained.
And the absorbance was measured using the obtained self-extinguishing carbon-containing modified polystyrene resin expanded particles, and the polystyrene resin ratio was calculated.
Further, using the obtained self-extinguishing carbon-containing modified polystyrene resin foamed particles, a self-extinguishing carbon-containing modified polystyrene resin foamed molded article was obtained in the same manner as in Example 1.
Then, using the obtained self-extinguishing carbon-containing modified polystyrene resin foam molded article, the expansion ratio, the heating dimensional change rate, the chemical resistance, and the burning rate were measured.

[Example 4]
1880 g of a polypropylene resin (manufactured by Prime Polymer, trade name “F-744NP”, melting point: 140 ° C.) and 120 g of furnace black (trade name “# 650B”, manufactured by Mitsubishi Chemical Corporation) are mixed, and this mixture is extruded. , Melt-kneaded and granulated into pellets by strand cutting to obtain spherical (egg-like) carbon-containing polypropylene resin particles containing 6% by mass of furnace black in polypropylene resin.
The carbon-containing polypropylene resin particles at this time were adjusted to 80 mmg per 100 particles and an average particle diameter of about 1 mm.
Next, 800 g of the carbon-containing polypropylene resin particles are put into a 5 L autoclave equipped with a stirrer, and 2 kg of pure water, 20 g of magnesium pyrophosphate, and 0.5 g of sodium dodecylbenzenesulfonate are added as an aqueous medium, and the resulting mixture is stirred into the aqueous medium. Suspended and held for 10 minutes, then heated to 60 ° C. to obtain an aqueous suspension.
Next, 400 g of a styrene monomer in which 0.8 g of dicumyl peroxide was dissolved in this suspension was dropped in 30 minutes. After dropping, the mixture was held for 30 minutes, and the styrene monomer was absorbed by the carbon-containing polypropylene resin particles.
Next, the temperature of the reaction system is raised to 135 ° C., which is 5 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and maintained for 2 hours to polymerize the styrene monomer in the carbon-containing polypropylene resin particles (first Polymerization).
Next, the reaction liquid of the first polymerization is set to 120 ° C., which is 20 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and 1.5 g of sodium dodecylbenzenesulfonate is added to this suspension, and then the polymerization is started. As an agent, 800 g of a styrene monomer in which 3.6 g of dicumyl peroxide was dissolved was dropped over 4 hours, and polymerization (second polymerization) was performed while absorbing the carbon-containing polypropylene resin particles.
After completion of the dropping, the mixture was held at 120 ° C. for 1 hour, then heated to 140 ° C. and held for 3 hours to complete the polymerization, thereby obtaining carbon-containing modified polystyrene resin particles.
Thereafter, the temperature of the reaction system was set to 60 ° C., and 100 g of tri (2,3-dibromopropyl) isocyanate (manufactured by Nippon Kasei Co., Ltd.) and 2,3-dimethyl-2,3-diphenylbutane were added to this suspension. 40g (made by Kayaku Akzo Co., Ltd.) was charged. After the charging, the temperature of the reaction system was raised to 140 ° C, and the stirring was continued for 4 hours to obtain self-extinguishing carbon-containing modified polystyrene resin particles. In the same manner as in Example 1, self-extinguishing carbon-containing modified polystyrene resin expanded particles were obtained.
And the absorbance was measured using the obtained self-extinguishing carbon-containing modified polystyrene resin expanded particles, and the polystyrene resin ratio was calculated.
Further, using the obtained self-extinguishing carbon-containing modified polystyrene resin foamed particles, a self-extinguishing carbon-containing modified polystyrene resin foamed molded article was obtained in the same manner as in Example 1.
Then, using the obtained self-extinguishing carbon-containing modified polystyrene resin foam molded article, the expansion ratio, the heating dimensional change rate, the chemical resistance, and the burning rate were measured.

[Example 5]
1940 g of polypropylene resin (manufactured by Prime Polymer, trade name “F-744NP”, melting point: 140 ° C.) and 60 g of furnace black (trade name “# 650B”, manufactured by Mitsubishi Chemical Corporation) are mixed, and this mixture is extruded. , Melt-kneaded and granulated into pellets by strand cutting to obtain spherical (egg-like) carbon-containing polypropylene resin particles containing 3% by mass of furnace black in polypropylene resin.
The carbon-containing polypropylene resin particles at this time were adjusted to 80 mmg per 100 particles and an average particle diameter of about 1 mm.
Next, 800 g of the carbon-containing polypropylene resin particles are put into a 5 L autoclave equipped with a stirrer, and 2 kg of pure water, 20 g of magnesium pyrophosphate, and 0.5 g of sodium dodecylbenzenesulfonate are added as an aqueous medium, and the resulting mixture is stirred into the aqueous medium. Suspended and held for 10 minutes, then heated to 60 ° C. to obtain an aqueous suspension.
Next, 400 g of a styrene monomer in which 0.8 g of dicumyl peroxide was dissolved in this suspension was dropped in 30 minutes. After dropping, the mixture was held for 30 minutes, and the styrene monomer was absorbed by the carbon-containing polypropylene resin particles.
Next, the temperature of the reaction system is raised to 135 ° C., which is 5 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and maintained for 2 hours to polymerize the styrene monomer in the carbon-containing polypropylene resin particles (first Polymerization).
Next, the reaction liquid of the first polymerization is set to 120 ° C., which is 20 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and 1.5 g of sodium dodecylbenzenesulfonate is added to this suspension, and then the polymerization is started. As an agent, 800 g of a styrene monomer in which 3.6 g of dicumyl peroxide was dissolved was dropped over 4 hours, and polymerization (second polymerization) was performed while absorbing the carbon-containing polypropylene resin particles.
After completion of the dropping, the mixture was held at 120 ° C. for 1 hour, then heated to 140 ° C. and held for 3 hours to complete the polymerization, thereby obtaining carbon-containing modified polystyrene resin particles.
Thereafter, the temperature of the reaction system was set to 60 ° C., and 40 g of tri (2,3-dibromopropyl) isocyanate (manufactured by Nippon Kasei Co., Ltd.) and 20 g of dicumyl peroxide (manufactured by NOF Corporation) were added to the suspension. And after the addition, the temperature of the reaction system was raised to 140 ° C., and the stirring was continued for 4 hours to obtain self-extinguishing carbon-containing modified polystyrene resin particles. Carbon-containing modified polystyrene resin foamed particles were obtained.
And the absorbance was measured using the obtained self-extinguishing carbon-containing modified polystyrene resin expanded particles, and the polystyrene resin ratio was calculated.
Further, using the obtained self-extinguishing carbon-containing modified polystyrene resin foamed particles, a self-extinguishing carbon-containing modified polystyrene resin foamed molded article was obtained in the same manner as in Example 1.
Then, using the obtained self-extinguishing carbon-containing modified polystyrene resin foam molded article, the expansion ratio, the heating dimensional change rate, the chemical resistance, and the burning rate were measured.

[Example 6]
1940 g of polypropylene resin (trade name “PC540R”, manufactured by Sun Allomer Co., Ltd., melting point: 132 ° C.) and 60 g of furnace black (trade name “# 650B”, manufactured by Mitsubishi Chemical Corporation) are mixed, and this mixture is supplied to an extruder. The mixture was melt-kneaded and granulated into pellets by strand cutting to obtain spherical (egg-like) carbon-containing polypropylene resin particles containing 3% by mass of furnace black in polypropylene resin.
The carbon-containing polypropylene resin particles at this time were adjusted to 80 mmg per 100 particles and an average particle diameter of about 1 mm.
Next, 800 g of the carbon-containing polypropylene resin particles are put into a 5 L autoclave equipped with a stirrer, and 2 kg of pure water, 20 g of magnesium pyrophosphate, and 0.5 g of sodium dodecylbenzenesulfonate are added as an aqueous medium, and the resulting mixture is stirred into the aqueous medium. Suspended and held for 10 minutes, then heated to 60 ° C. to obtain an aqueous suspension.
Next, 400 g of a styrene monomer in which 0.8 g of dicumyl peroxide was dissolved in this suspension was dropped in 30 minutes. After dropping, the mixture was held for 30 minutes, and the styrene monomer was absorbed by the carbon-containing polypropylene resin particles.
Next, the temperature of the reaction system is raised to 140 ° C., which is 8 ° C. higher than the melting point of the carbon-containing polypropylene resin particles, and held for 2 hours to polymerize the styrene monomer in the carbon-containing polypropylene resin particles (first Polymerization).
Next, the reaction liquid of the first polymerization is set to 125 ° C., which is 7 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and 1.5 g of sodium dodecylbenzenesulfonate is added to this suspension, and then the polymerization is started. Example 1 except that 800 g of a styrene monomer in which 3.6 g of dicumyl peroxide was dissolved as an agent was dropped over 4 hours and the polymerization (second polymerization) was performed while absorbing the carbon-containing polypropylene resin particles. In the same manner as above, self-extinguishing carbon-containing modified polystyrene resin expanded particles were obtained.
And the absorbance was measured using the obtained self-extinguishing carbon-containing modified polystyrene resin expanded particles, and the polystyrene resin ratio was calculated.
Further, using the obtained self-extinguishing carbon-containing modified polystyrene resin foamed particles, a self-extinguishing carbon-containing modified polystyrene resin foamed molded article was obtained in the same manner as in Example 1.
Then, using the obtained self-extinguishing carbon-containing modified polystyrene resin foam molded article, the expansion ratio, the heating dimensional change rate, the chemical resistance, and the burning rate were measured.

[Comparative Example 1]
1880 g of a polypropylene resin (manufactured by Prime Polymer, trade name “F-744NP”, melting point: 140 ° C.) and 120 g of furnace black (trade name “# 650B”, manufactured by Mitsubishi Chemical Corporation) are mixed, and this mixture is extruded. , Melt-kneaded and granulated into pellets by strand cutting to obtain spherical (egg-like) carbon-containing polypropylene resin particles containing 6% by mass of furnace black in polypropylene resin.
The carbon-containing polypropylene resin particles at this time were adjusted to 80 mmg per 100 particles and an average particle diameter of about 1 mm.
Next, 600 g of the carbon-containing polypropylene-based resin particles are put into a 5 L autoclave with a stirrer, and 2 kg of pure water, 20 g of magnesium pyrophosphate, and 0.5 g of sodium dodecylbenzenesulfonate are added as an aqueous medium, and the resulting mixture is stirred into the aqueous medium. Suspended and held for 10 minutes, then heated to 60 ° C. to obtain an aqueous suspension.
Next, 300 g of a styrene monomer in which 0.6 g of dicumyl peroxide was dissolved in this suspension was dropped in 30 minutes. After dropping, the mixture was held for 30 minutes, and the styrene monomer was absorbed by the carbon-containing polypropylene resin particles.
Next, the temperature of the reaction system is raised to 120 ° C., which is 20 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and held for 2 hours, and the styrene monomer is polymerized in the carbon-containing polypropylene resin particles (first Polymerization).
Next, the reaction liquid of the first polymerization is set to 110 ° C., which is 30 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and 1.5 g of sodium dodecylbenzenesulfonate is added to this suspension, and then the polymerization is started. This was carried out except that 1100 g of a styrene monomer in which 4.2 g of dicumyl peroxide was dissolved as an agent was dropped over 5 hours and 30 minutes and the polymerization was carried out while absorbing the carbon-containing polypropylene resin particles (second polymerization). In the same manner as in Example 1, carbon-containing modified polystyrene resin expanded particles were obtained.
And the absorbance was measured using the obtained carbon-containing modified polystyrene resin foamed particles, and the polystyrene resin ratio was calculated.
Further, using the obtained carbon-containing modified polystyrene resin foamed particles, a carbon-containing modified polystyrene resin foamed molded article was obtained in the same manner as in Example 1.
The obtained carbon-containing modified polystyrene resin foamed molded article was used to measure the expansion ratio, rate of change in heating dimensions, chemical resistance, and burning rate.

[Comparative Example 2]
1940 g of polypropylene resin (manufactured by Prime Polymer, trade name “F-744NP”, melting point: 140 ° C.) and 60 g of furnace black (trade name “# 650B”, manufactured by Mitsubishi Chemical Corporation) are mixed, and this mixture is extruded. , Melt-kneaded and granulated into pellets by strand cutting to obtain spherical (egg-like) carbon-containing polypropylene resin particles containing 3% by mass of furnace black in polypropylene resin.
The carbon-containing polypropylene resin particles at this time were adjusted to 80 mmg per 100 particles and an average particle diameter of about 1 mm.
Next, 800 g of the carbon-containing polypropylene resin particles are put into a 5 L autoclave equipped with a stirrer, and 2 kg of pure water, 20 g of magnesium pyrophosphate, and 0.5 g of sodium dodecylbenzenesulfonate are added as an aqueous medium, and the resulting mixture is stirred into the aqueous medium. Suspended and held for 10 minutes, then heated to 60 ° C. to obtain an aqueous suspension.
Next, 400 g of a styrene monomer in which 0.8 g of dicumyl peroxide was dissolved in this suspension was dropped in 30 minutes. After dropping, the mixture was held for 30 minutes, and the styrene monomer was absorbed by the carbon-containing polypropylene resin particles.
Next, the temperature of the reaction system is raised to 120 ° C., which is 20 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and held for 2 hours, and the styrene monomer is polymerized in the carbon-containing polypropylene resin particles (first Polymerization).
Next, the first polymerization reaction solution is set to 110 ° C., which is 30 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and 1.5 g of sodium dodecylbenzenesulfonate is added to this suspension, and then the polymerization is started. Example 1 except that 800 g of a styrene monomer in which 3.6 g of dicumyl peroxide was dissolved as an agent was dropped over 4 hours and polymerization (second polymerization) was performed while absorbing the carbon-containing polypropylene resin particles. In the same manner as above, carbon-containing modified polystyrene resin expanded particles were obtained.
And the absorbance was measured using the obtained carbon-containing modified polystyrene resin foamed particles, and the polystyrene resin ratio was calculated.
Further, using the obtained carbon-containing modified polystyrene resin foamed particles, a carbon-containing modified polystyrene resin foamed molded article was obtained in the same manner as in Example 1.
The obtained carbon-containing modified polystyrene resin foamed molded article was used to measure the expansion ratio, rate of change in heating dimensions, chemical resistance, and burning rate.

[Comparative Example 3]
1940 g of polypropylene resin (manufactured by Prime Polymer, trade name “F-744NP”, melting point: 140 ° C.) and 60 g of furnace black (trade name “# 650B”, manufactured by Mitsubishi Chemical Corporation) are mixed, and this mixture is extruded. , Melt-kneaded and granulated into pellets by strand cutting to obtain spherical (egg-like) carbon-containing polypropylene resin particles containing 3% by mass of furnace black in polypropylene resin.
The carbon-containing polypropylene resin particles at this time were adjusted to 80 mmg per 100 particles and an average particle diameter of about 1 mm.
Next, 1000 g of the carbon-containing polypropylene resin particles are put into a 5 L autoclave equipped with a stirrer, and 2 kg of pure water, 20 g of magnesium pyrophosphate, and 0.5 g of sodium dodecylbenzenesulfonate are added as an aqueous medium, and the resulting mixture is stirred into the aqueous medium. Suspended and held for 10 minutes, and then heated to 60 ° C. to obtain an aqueous suspension.
Next, 500 g of a styrene monomer in which 1.0 g of dicumyl peroxide was dissolved in this suspension was dropped in 30 minutes. After dropping, the mixture was held for 30 minutes, and the styrene monomer was absorbed by the carbon-containing polypropylene resin particles.
Next, the temperature of the reaction system is raised to 120 ° C., which is 20 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and held for 2 hours, and the styrene monomer is polymerized in the carbon-containing polypropylene resin particles (first Polymerization).
Next, the first polymerization reaction solution is set to 110 ° C., which is 30 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and 1.5 g of sodium dodecylbenzenesulfonate is added to this suspension, and then the polymerization is started. 500 g of a styrene monomer in which 3 g of dicumyl peroxide was dissolved as an agent was dropped over 2 hours and 30 minutes, and polymerization (second polymerization) was carried out while absorbing the carbon-containing polypropylene resin particles.
After completion of the dropping, the mixture was held at 120 ° C. for 1 hour, then heated to 140 ° C. and held for 3 hours to complete the polymerization, thereby obtaining carbon-containing modified polystyrene resin particles.
Thereafter, the temperature of the reaction system was set to 60 ° C., and 100 g of tri (2,3-dibromopropyl) isocyanate (manufactured by Nippon Kasei Co., Ltd.) and 2,3-dimethyl-2,3-diphenylbutane were added to this suspension. 20 g (manufactured by Kayaku Akzo) was added, and after the addition, the temperature of the reaction system was raised to 140 ° C. and stirring was continued for 4 hours to obtain carbon-containing modified polystyrene resin particles, as in Example 1. Thus, carbon-containing modified polystyrene resin expanded particles were obtained.
And the absorbance was measured using the obtained carbon-containing modified polystyrene resin foamed particles, and the polystyrene resin ratio was calculated.
Further, using the obtained carbon-containing modified polystyrene resin foamed particles, a carbon-containing modified polystyrene resin foamed molded article was obtained in the same manner as in Example 1.
The obtained carbon-containing modified polystyrene resin foamed molded article was used to measure the expansion ratio, rate of change in heating dimensions, chemical resistance, and burning rate.

[Comparative Example 4]
1880 g of polypropylene resin (trade name “PC540R”, manufactured by Sun Allomer Co., Ltd., melting point: 132 ° C.) and 120 g of furnace black (trade name “# 650B”, manufactured by Mitsubishi Chemical Corporation) are mixed, and this mixture is supplied to an extruder. Then, the mixture was melt-kneaded and granulated into pellets by strand cutting to obtain spherical (egg-like) carbon-containing polypropylene-based resin particles containing 6% by mass of furnace black in a polypropylene-based resin.
The carbon-containing polypropylene resin particles at this time were adjusted to 80 mmg per 100 particles and an average particle diameter of about 1 mm.
Next, 800 g of the carbon-containing polypropylene resin particles are put into a 5 L autoclave equipped with a stirrer, and 2 kg of pure water, 20 g of magnesium pyrophosphate, and 0.5 g of sodium dodecylbenzenesulfonate are added as an aqueous medium, and the resulting mixture is stirred into the aqueous medium. Suspended and held for 10 minutes, then heated to 60 ° C. to obtain an aqueous suspension.
Next, 400 g of a styrene monomer in which 0.8 g of dicumyl peroxide was dissolved in this suspension was dropped in 30 minutes. After dropping, the mixture was held for 30 minutes, and the styrene monomer was absorbed by the carbon-containing polypropylene resin particles.
Next, the temperature of the reaction system is raised to 140 ° C., which is 8 ° C. higher than the melting point of the carbon-containing polypropylene resin particles, and held for 2 hours to polymerize the styrene monomer in the carbon-containing polypropylene resin particles (first Polymerization).
Next, the reaction liquid of the first polymerization was set to 145 ° C. which is 13 ° C. higher than the melting point of the carbon-containing polypropylene resin particles, and 1.5 g of sodium dodecylbenzenesulfonate was added to this suspension, and then polymerization was started. As an agent, 800 g of a styrene monomer in which 3.6 g of dicumyl peroxide was dissolved was dropped over 4 hours, and polymerization (second polymerization) was performed while absorbing the carbon-containing polypropylene resin particles.
After completion of the dropping, the mixture was held at 120 ° C. for 1 hour, then heated to 140 ° C. and held for 3 hours to complete the polymerization, thereby obtaining carbon-containing modified polystyrene resin particles.
Thereafter, the temperature of the reaction system was set to 60 ° C., and 100 g of tri (2,3-dibromopropyl) isocyanate (manufactured by Nippon Kasei Co., Ltd.) and 2,3-dimethyl-2,3-diphenylbutane were added to this suspension. 40 g (manufactured by Kayaku Akzo Co., Ltd.) was added, and after the addition, the temperature of the reaction system was raised to 140 ° C. and stirring was continued for 4 hours to obtain carbon-containing modified polystyrene resin particles, as in Example 1. Thus, carbon-containing modified polystyrene resin expanded particles were obtained.
And the absorbance was measured using the obtained carbon-containing modified polystyrene resin foamed particles, and the polystyrene resin ratio was calculated.
Further, using the obtained carbon-containing modified polystyrene resin foamed particles, a carbon-containing modified polystyrene resin foamed molded article was obtained in the same manner as in Example 1.
The obtained carbon-containing modified polystyrene resin foamed molded article was used to measure the expansion ratio, rate of change in heating dimensions, chemical resistance, and burning rate.

[Comparative Example 5]
1880 g of a polypropylene resin (manufactured by Prime Polymer, trade name “F-744NP”, melting point: 140 ° C.) and 120 g of furnace black (trade name “# 650B”, manufactured by Mitsubishi Chemical Corporation) are mixed, and this mixture is extruded. , Melt-kneaded and granulated into pellets by strand cutting to obtain spherical (egg-like) carbon-containing polypropylene resin particles containing 6% by mass of furnace black in polypropylene resin.
The carbon-containing polypropylene resin particles at this time were adjusted to 80 mmg per 100 particles and an average particle diameter of about 1 mm.
Next, 600 g of the carbon-containing polypropylene-based resin particles are put into a 5 L autoclave with a stirrer, and 2 kg of pure water, 20 g of magnesium pyrophosphate, and 0.5 g of sodium dodecylbenzenesulfonate are added as an aqueous medium, and the resulting mixture is stirred into the aqueous medium. Suspended and held for 10 minutes, then heated to 60 ° C. to obtain an aqueous suspension.
Next, 300 g of a styrene monomer in which 0.6 g of dicumyl peroxide was dissolved in this suspension was dropped in 30 minutes. After dropping, the mixture was held for 30 minutes, and the styrene monomer was absorbed by the carbon-containing polypropylene resin particles.
Next, the temperature of the reaction system is raised to 120 ° C., which is 20 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and held for 2 hours, and the styrene monomer is polymerized in the carbon-containing polypropylene resin particles (first Polymerization).
Next, the first polymerization reaction solution is set to 110 ° C., which is 30 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and 1.5 g of sodium dodecylbenzenesulfonate is added to this suspension, and then the polymerization is started. As an agent, 1100 g of a styrene monomer in which 4.2 g of dicumyl peroxide was dissolved was dropped over 5 hours and 30 minutes, and polymerization (second polymerization) was performed while absorbing the carbon-containing polypropylene resin particles.
After completion of the dropping, the mixture was held at 120 ° C. for 1 hour, then heated to 140 ° C. and held for 3 hours to complete the polymerization, thereby obtaining carbon-containing modified polystyrene resin particles.
Thereafter, the temperature of the reaction system was set to 60 ° C., and 80 g of tri (2,3-dibromopropyl) isocyanate (manufactured by Nippon Kasei Co., Ltd.) and 2,3-dimethyl-2,3-diphenylbutane were added to this suspension. 30g (made by Kayaku Akzo Co., Ltd.) was charged, and after the charging, the temperature of the reaction system was raised to 140 ° C, and stirring was continued for 4 hours to obtain self-extinguishing carbon-containing modified polystyrene resin particles. In the same manner as in Example 1, self-extinguishing carbon-containing modified polystyrene resin expanded particles were obtained.
And the absorbance was measured using the obtained self-extinguishing carbon-containing modified polystyrene resin expanded particles, and the polystyrene resin ratio was calculated.
Further, using the obtained self-extinguishing carbon-containing modified polystyrene resin foamed particles, a self-extinguishing carbon-containing modified polystyrene resin foamed molded article was obtained in the same manner as in Example 1.
Then, using the obtained self-extinguishing carbon-containing modified polystyrene resin foam molded article, the expansion ratio, the heating dimensional change rate, the chemical resistance, and the burning rate were measured.

[Comparative Example 6]
1880 g of a polypropylene resin (manufactured by Prime Polymer, trade name “F-744NP”, melting point: 140 ° C.) and 120 g of furnace black (trade name “# 650B”, manufactured by Mitsubishi Chemical Corporation) are mixed, and this mixture is extruded. , Melt-kneaded and granulated into pellets by strand cutting to obtain spherical (egg-like) carbon-containing polypropylene resin particles containing 6% by mass of furnace black in polypropylene resin.
The carbon-containing polypropylene resin particles at this time were adjusted to 80 mmg per 100 particles and an average particle diameter of about 1 mm.
Next, 600 g of the carbon-containing polypropylene-based resin particles are put into a 5 L autoclave with a stirrer, and 2 kg of pure water, 20 g of magnesium pyrophosphate, and 0.5 g of sodium dodecylbenzenesulfonate are added as an aqueous medium, and the resulting mixture is stirred into the aqueous medium. Suspended and held for 10 minutes, then heated to 60 ° C. to obtain an aqueous suspension.
Next, 300 g of a styrene monomer in which 0.6 g of dicumyl peroxide was dissolved in this suspension was dropped in 30 minutes. After dropping, the mixture was held for 30 minutes, and the styrene monomer was absorbed by the carbon-containing polypropylene resin particles.
Next, the temperature of the reaction system is raised to 135 ° C., which is 5 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and maintained for 2 hours to polymerize the styrene monomer in the carbon-containing polypropylene resin particles (first Polymerization).
Next, the reaction liquid of the first polymerization is set to 120 ° C., which is 20 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and 1.5 g of sodium dodecylbenzenesulfonate is added to this suspension, and then the polymerization is started. As an agent, 1100 g of a styrene monomer in which 4.2 g of dicumyl peroxide was dissolved was dropped over 5 hours and 30 minutes, and polymerization (second polymerization) was performed while absorbing the carbon-containing polypropylene resin particles.
After completion of the dropping, the mixture was held at 120 ° C. for 1 hour, then heated to 140 ° C. and held for 3 hours to complete the polymerization, thereby obtaining carbon-containing modified polystyrene resin particles.
Thereafter, the temperature of the reaction system was set to 60 ° C., and 40 g of tri (2,3-dibromopropyl) isocyanate (manufactured by Nippon Kasei Co., Ltd.) was added to this suspension. The mixture was stirred for 4 hours to obtain carbon-containing modified polystyrene resin particles in the same manner as in Example 1, except that carbon-containing modified polystyrene resin particles were obtained.
And the absorbance was measured using the obtained carbon-containing modified polystyrene resin foamed particles, and the polystyrene resin ratio was calculated.
Further, using the obtained carbon-containing modified polystyrene resin foamed particles, a carbon-containing modified polystyrene resin foamed molded article was obtained in the same manner as in Example 1.
The obtained carbon-containing modified polystyrene resin foamed molded article was used to measure the expansion ratio, rate of change in heating dimensions, chemical resistance, and burning rate.

[Comparative Example 7]
1940 g of polypropylene resin (manufactured by Prime Polymer, trade name “F-744NP”, melting point: 140 ° C.) and 60 g of furnace black (trade name “# 650B”, manufactured by Mitsubishi Chemical Corporation) are mixed, and this mixture is extruded. , Melt-kneaded and granulated into pellets by strand cutting to obtain spherical (egg-like) carbon-containing polypropylene resin particles containing 3% by mass of furnace black in polypropylene resin.
The carbon-containing polypropylene resin particles at this time were adjusted to 80 mmg per 100 particles and an average particle diameter of about 1 mm.
Next, 800 g of the carbon-containing polypropylene resin particles are put into a 5 L autoclave equipped with a stirrer, and 2 kg of pure water, 20 g of magnesium pyrophosphate, and 0.5 g of sodium dodecylbenzenesulfonate are added as an aqueous medium, and the resulting mixture is stirred into the aqueous medium. Suspended and held for 10 minutes, then heated to 60 ° C. to obtain an aqueous suspension.
Next, 400 g of a styrene monomer in which 0.8 g of dicumyl peroxide was dissolved in this suspension was dropped in 30 minutes. After dropping, the mixture was held for 30 minutes, and the styrene monomer was absorbed by the carbon-containing polypropylene resin particles.
Next, the temperature of the reaction system is raised to 135 ° C., which is 5 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and maintained for 2 hours to polymerize the styrene monomer in the carbon-containing polypropylene resin particles (first Polymerization).
Next, the reaction liquid of the first polymerization is set to 120 ° C., which is 20 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and 1.5 g of sodium dodecylbenzenesulfonate is added to this suspension, and then the polymerization is started. As an agent, 800 g of a styrene monomer in which 3.6 g of dicumyl peroxide was dissolved was dropped over 4 hours, and polymerization (second polymerization) was performed while absorbing the carbon-containing polypropylene resin particles.
After completion of the dropping, the mixture was held at 120 ° C. for 1 hour, then heated to 140 ° C. and held for 3 hours to complete the polymerization, thereby obtaining carbon-containing modified polystyrene resin particles.
Thereafter, the temperature of the reaction system was set to 60 ° C., and 40 g of tri (2,3-dibromopropyl) isocyanate (manufactured by Nippon Kasei Co., Ltd.) and 2,3-dimethyl-2,3-diphenylbutane were added to this suspension. (Kyaku Akzo Co., Ltd.) 80 g was charged, and after the charging, the temperature of the reaction system was raised to 140 ° C., and the stirring was continued for 4 hours to obtain self-extinguishing carbon-containing modified polystyrene resin particles. In the same manner as in Example 1, self-extinguishing carbon-containing modified polystyrene resin expanded particles were obtained.
And the absorbance was measured using the obtained self-extinguishing carbon-containing modified polystyrene resin expanded particles, and the polystyrene resin ratio was calculated.
Further, using the obtained self-extinguishing carbon-containing modified polystyrene resin foamed particles, a self-extinguishing carbon-containing modified polystyrene resin foamed molded article was obtained in the same manner as in Example 1.
Then, using the obtained self-extinguishing carbon-containing modified polystyrene resin foam molded article, the expansion ratio, the heating dimensional change rate, the chemical resistance, and the burning rate were measured.

[Comparative Example 8]
1880 g of polypropylene resin (manufactured by Prime Polymer, trade name “F-744NP”, melting point: 140 ° C.) and 120 g of furnace black (trade name “# 680B”, manufactured by Mitsubishi Chemical Co., Ltd.) are mixed, and this mixture is extruded. , Melt-kneaded and granulated into pellets by strand cutting to obtain spherical (egg-like) carbon-containing polypropylene resin particles containing 6% by mass of furnace black in polypropylene resin.
The carbon-containing polypropylene resin particles at this time were adjusted to 80 mmg per 100 particles and an average particle diameter of about 1 mm.
Next, 300 g of the carbon-containing polypropylene resin particles are put into a 5 L autoclave equipped with a stirrer, and 2 kg of pure water, 20 g of magnesium pyrophosphate, and 0.5 g of sodium dodecylbenzenesulfonate are added as an aqueous medium, and the resulting mixture is stirred into the aqueous medium. Suspended and held for 10 minutes, and then heated to 60 ° C. to obtain an aqueous suspension.
Next, 100 g of a styrene monomer in which 0.8 g of dicumyl peroxide was dissolved in this suspension was dropped in 30 minutes. After dropping, the mixture was held for 30 minutes, and the styrene monomer was absorbed by the carbon-containing polypropylene resin particles.
Next, the temperature of the reaction system is raised to 135 ° C., which is 5 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and maintained for 2 hours to polymerize the styrene monomer in the carbon-containing polypropylene resin particles (first Polymerization).
Next, the reaction liquid of the first polymerization is set to 120 ° C., which is 20 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and 1.5 g of sodium dodecylbenzenesulfonate is added to this suspension, and then the polymerization is started. Example 1 except that 1600 g of a styrene monomer in which 5.4 g of dicumyl peroxide was dissolved as an agent was added dropwise over 8 hours and polymerization (second polymerization) was performed while absorbing the carbon-containing polypropylene resin particles. In the same manner as above, carbon-containing modified polystyrene resin expanded particles were obtained.
Further, using the obtained carbon-containing modified polystyrene resin foamed particles, a carbon-containing modified polystyrene resin foamed molded article was obtained in the same manner as in Example 1.
Then, using the obtained carbon-containing modified polystyrene resin foamed molded article, the expansion ratio, the heating dimensional change rate, and the chemical resistance were measured.

[Comparative Example 9]
1880 g of polypropylene resin (manufactured by Prime Polymer, trade name “F-744NP”, melting point: 140 ° C.) and 120 g of furnace black (trade name “# 680B”, manufactured by Mitsubishi Chemical Co., Ltd.) are mixed, and this mixture is extruded. , Melt-kneaded and granulated into pellets by strand cutting to obtain spherical (egg-like) carbon-containing polypropylene resin particles containing 6% by mass of furnace black in polypropylene resin.
The carbon-containing polypropylene resin particles at this time were adjusted to 80 mmg per 100 particles and an average particle diameter of about 1 mm.
Next, 1200 g of the carbon-containing polypropylene resin particles are put into a 5 L autoclave equipped with a stirrer, and 2 kg of pure water, 20 g of magnesium pyrophosphate, and 0.5 g of sodium dodecylbenzenesulfonate are added as an aqueous medium, and the mixture is stirred into the aqueous medium. Suspended and held for 10 minutes, and then heated to 60 ° C. to obtain an aqueous suspension.
Next, 300 g of a styrene monomer in which 0.8 g of dicumyl peroxide was dissolved in this suspension was dropped in 30 minutes. After dropping, the mixture was held for 30 minutes, and the styrene monomer was absorbed by the carbon-containing polypropylene resin particles.
Next, the temperature of the reaction system is raised to 135 ° C., which is 5 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and maintained for 2 hours to polymerize the styrene monomer in the carbon-containing polypropylene resin particles (first Polymerization).
Next, the reaction liquid of the first polymerization is set to 120 ° C., which is 20 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and 1.5 g of sodium dodecylbenzenesulfonate is added to this suspension, and then the polymerization is started. Example 1 except that 400 g of a styrene monomer in which 2.4 g of dicumyl peroxide was dissolved as an agent was added dropwise over 2 hours and polymerization (second polymerization) was performed while absorbing the carbon-containing polypropylene resin particles. In the same manner as described above, attempts were made to obtain carbon-containing modified polystyrene resin expanded particles (bulk expansion ratio 30 times), but the foamability was low, and only those having a bulk expansion ratio of 10 times were obtained.
In addition, the foaming molding of the expansion ratio 30 times was not obtained.

[Comparative Example 10]
1880 g of a polypropylene resin (manufactured by Prime Polymer, trade name “F-744NP”, melting point: 140 ° C.) and 120 g of furnace black (trade name “# 650B”, manufactured by Mitsubishi Chemical Corporation) are mixed, and this mixture is extruded. , Melt-kneaded and granulated into pellets by strand cutting to obtain spherical (egg-like) carbon-containing polypropylene resin particles containing 6% by mass of furnace black in polypropylene resin.
The carbon-containing polypropylene resin particles at this time were adjusted to 80 mmg per 100 particles and an average particle diameter of about 1 mm.
Next, 800 g of the carbon-containing polypropylene resin particles are put into a 5 L autoclave equipped with a stirrer, and 2 kg of pure water, 20 g of magnesium pyrophosphate, and 0.5 g of sodium dodecylbenzenesulfonate are added as an aqueous medium, and the resulting mixture is stirred into the aqueous medium. Suspended and held for 10 minutes, then heated to 60 ° C. to obtain an aqueous suspension.
Next, 400 g of a styrene monomer in which 0.8 g of dicumyl peroxide was dissolved in this suspension was dropped in 30 minutes. After dropping, the mixture was held for 30 minutes, and the styrene monomer was absorbed by the carbon-containing polypropylene resin particles.
Next, the temperature of the reaction system is raised to 135 ° C., which is 5 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and maintained for 2 hours to polymerize the styrene monomer in the carbon-containing polypropylene resin particles (first Polymerization).
Next, the reaction liquid of the first polymerization is set to 120 ° C., which is 20 ° C. lower than the melting point of the carbon-containing polypropylene resin particles, and 1.5 g of sodium dodecylbenzenesulfonate is added to this suspension, and then the polymerization is started. As an agent, 800 g of a styrene monomer in which 3.6 g of dicumyl peroxide was dissolved was dropped over 4 hours, and polymerization (second polymerization) was performed while absorbing the carbon-containing polypropylene resin particles.
After completion of the dropping, the mixture was held at 120 ° C. for 1 hour, then heated to 140 ° C. and held for 3 hours to complete the polymerization, thereby obtaining carbon-containing modified polystyrene resin particles.
Next, it was cooled to room temperature, and the resin particles were taken out from the 5 L autoclave. 2 kg of carbon-containing modified polystyrene resin particles and 2 L of water after taking out were again put into a 5 L autoclave with a stirrer, and 300 g of butane as a blowing agent was injected into a 5 L autoclave with a stirrer. After the injection, the temperature was raised to 70 ° C. and stirring was continued for 4 hours.
Then, it cooled to normal temperature, took out from the 5L autoclave, dehydrated and dried, and then obtained expandable carbon-containing modified polystyrene resin particles.
Next, the obtained expandable carbon-containing modified polystyrene resin particles were pre-expanded to a bulk expansion ratio of 30 times to obtain carbon-containing modified polystyrene resin expanded particles.
And the absorbance was measured using the obtained carbon-containing modified polystyrene resin foamed particles, and the polystyrene resin ratio was calculated.
Further, using the obtained carbon-containing modified polystyrene resin foamed particles, a carbon-containing modified polystyrene resin foamed molded article was obtained in the same manner as in Example 1.
The obtained carbon-containing modified polystyrene resin foamed molded article was used to measure the expansion ratio, rate of change in heating dimensions, chemical resistance, and burning rate.

Table 1 shows the production conditions of Examples 1 to 6, and the measurement results and evaluation results of the tests described above for the obtained self-extinguishing carbon-containing modified polystyrene resin foam moldings.
Table 2 shows the production conditions of Comparative Examples 1 to 5, and the measurement results and evaluation results of the tests described above for the obtained carbon-containing modified polystyrene resin foam molded articles.
Table 3 shows the production conditions of Comparative Examples 6 to 10, and the measurement results and evaluation results of the above tests for the obtained carbon-containing modified polystyrene resin foam molded articles.
In Tables 1 to 3, “PP” represents a polypropylene resin, and “PS” represents a polystyrene resin.
In Tables 1 to 3, PP resin A represents Prime Polymer F-744NP, and PP resin B represents Sun Allomer PC540R.
Well, in Tables 1 to 3, flame retardant aid A represents 2,3-dimethyl-2,3-diphenylbutane, manufactured by Kayaku Akzo, and flame retardant aid B, manufactured by Nippon Oil & Fats Co., Ltd. Oxide is shown.

From the results shown in Tables 1 to 3, the foam molded articles produced in Examples 1 to 6 according to the present invention are 698 cm ⁻¹ and 1376 cm obtained from the infrared absorption spectrum of the particle center measured by ATR infrared spectroscopy. ^Produced in Comparative Examples 1 to 4 in which the ratio of polystyrene resin at the center of the particle calculated from the absorbance ratio at ^-1 (D ₆₉₈ / D ₁₃₇₆ ) is less than 1.2 times the polystyrene resin ratio of the entire particle Compared with the foamed molded product, the burning rate was excellent. Further, foamed molded body manufactured in Examples 1 to 6, the absorbance ratio at 698cm ^-1 and 1376cm ^-1 obtained from an infrared absorption spectrum of the particles heart measured by ATR method infrared spectroscopy _{(D 698} / D ₁₃₇₆ ), the ratio of the polystyrene resin calculated at the center of the particle is less than 1.2 times the polystyrene resin ratio of the entire particle, compared with the foamed molded articles produced in Comparative Examples 3-5. The rate was excellent.
In addition, the foam molded articles produced in Examples 1 to 6 were compared with Comparative Example 6 that did not contain a flame retardant aid, and the foam molded article produced in Comparative Example 10 that did not contain a flame retardant and a flame retardant aid. The burning rate was excellent.
Moreover, the foaming molding manufactured in Examples 1-6 is the foaming molding manufactured in the comparative example 7 which contains 4 mass parts of flame retardant adjuvants with respect to 100 mass parts of carbon containing modified polystyrene resin particles. In comparison, the heating dimensional change rate was excellent.
Moreover, compared with the foaming molding manufactured in Examples 1-6, the foaming molding manufactured in the comparative example 8 which contains about 566 mass parts of polystyrene-type resins with respect to 100 mass parts of carbon-containing polypropylene-type resin, Excellent chemical resistance and heat dimensional stability.
In addition, the foamed molded product produced in Examples 1 to 6 was compared with the foamed molded product produced in Comparative Example 9 containing about 66 parts by mass of a polystyrene-based resin with respect to 100 parts by mass of the carbon-containing polypropylene-based resin. The foam moldability was excellent.
Therefore, according to the present invention, it is possible to improve the disadvantages of both the polystyrene resin foam molded product and the polypropylene resin foam molded product, and to provide foam having excellent rigidity, foam moldability, chemical resistance, heat resistance and self-extinguishing properties. It has been demonstrated that molded bodies can be provided.

Using a molded body made of polystyrene resin and polypropylene resin as a standard sample, the absorbance ratio of this standard sample is measured, and the relationship between the polystyrene resin ratio (mass%) and the absorbance ratio (D ₆₉₈ / D ₁₃₇₆ ) is graphed. This is a calibration curve.

Claims (14)

698 cm obtained from an infrared absorption spectrum of a particle center portion containing 100 parts by mass or more and less than 400 parts by mass of a polystyrene resin and 100 parts by mass of the carbon-containing polypropylene resin and measured by ATR infrared spectroscopy. ^-1 and 1376 cm ⁻¹ The ratio of polystyrene resin calculated from the absorbance ratio (D ₆₉₈ / D ₁₃₇₆ ) is 1.2 times or more of the polystyrene resin ratio of the entire particle. A flame retardant is contained in an amount of 1.5 parts by mass or more and less than 6 parts by mass, and a flame retardant aid is contained in an amount of 0.1 to 3 parts by mass with respect to 100 parts by mass of the polystyrene resin particles. Self-extinguishing carbon-containing modified polystyrene resin particles. The absorbance ratio at 698cm ^-1 and 1376cm ^-1 obtained from an infrared absorption spectrum of the measured particle surface by ATR method infrared spectroscopy _{(D 698 /} D ₁₃₇₆₎ is in the range 0.1 to 2.5 The self-extinguishing carbon-containing modified polystyrene resin particles according to claim 1,  The flame retardant is tri (2,3-dibromopropyl) isocyanate, and the flame retardant aid is 2,3-dimethyl-2,3-diphenylbutane, 3,4-dimethyl-3,4-diphenylhexane, 3. The self-extinguishing carbon-containing modified polystyrene resin particle according to claim 1, comprising one or more selected from the group of milperoxide and cumene hydroperoxide.  The self-extinguishing carbon-containing modified polystyrene resin particles according to any one of claims 1 to 3, comprising 1 to 8% by mass of carbon particles.  A self-extinguishing carbon-containing modified polystyrene resin particle according to any one of claims 1 to 4, wherein the foaming self-extinguishing carbon-containing modified polystyrene resin particle is impregnated with a foaming agent. .  A self-extinguishing carbon-containing modified polystyrene resin expanded particle obtained by pre-expanding the expandable self-extinguishing carbon-containing modified polystyrene resin particle according to claim 5.  A self-extinguishing carbon-containing modified polystyrene-based resin foamed product, wherein the self-extinguishing carbon-containing modified polystyrene-based resin foamed particle according to claim 6 is filled in a mold and foam-molded.  The burning rate in accordance with FMVSS 302 is 0 mm / min, the shrinkage ratio in the dimensional change measurement under the condition of 80 ° C. in accordance with JIS K 6767 is 1.0% or less, and the expansion ratio is 20 to 40 times. The self-extinguishing carbon-containing modified polystyrene resin foam molded article according to claim 7. A step of dispersing 100 parts by mass of carbon-containing polypropylene resin particles, 100 parts by mass or more and less than 400 parts by mass of a styrene monomer, and a polymerization initiator in an aqueous suspension containing a dispersant;
Heating the obtained dispersion to a temperature at which the styrenic monomer is not substantially polymerized to impregnate the carbon-containing polypropylene resin particles with the styrenic monomer;
A step of performing the first polymerization of the styrene monomer at a temperature of (T-10) ° C. to (T + 20) ° C. when the melting point of the carbon-containing polypropylene resin particles is T ° C .;
Subsequent to the first polymerization step, a styrene monomer and a polymerization initiator are added, and the temperature is set to (T-25) ° C. to (T + 10) ° C. A step of impregnating the particles with the styrenic monomer and performing a second polymerization;
A self-extinguishing carbon-containing modification characterized by comprising a step of impregnating the resin particles during the second polymerization or the resin particles after the completion of the second polymerization with a flame retardant and a flame retardant aid. A method for producing polystyrene resin particles.  The method for producing self-extinguishing carbon-containing modified polystyrene resin particles according to claim 9, wherein the melting point of the carbon-containing polypropylene resin particles is 120 ° C. to 145 ° C.  The method for producing self-extinguishing carbon-containing modified polystyrene resin particles according to claim 9 or 10, wherein the carbon-containing polypropylene resin particles are propylene-ethylene copolymers. A method for producing modified polystyrene resin particles.  The self-extinguishing carbon-containing modified polystyrene resin particles obtained by the method for producing self-extinguishing carbon-containing modified polystyrene resin particles according to any one of claims 9 to 11 are impregnated with a foaming agent and foamed. A self-extinguishing carbon-containing modified polystyrene-based resin particle is obtained, which is characterized in that a foamable self-extinguishing carbon-containing modified polystyrene-based resin particle is obtained.  The foamable self-extinguishing carbon-containing modified polystyrene resin particles obtained by the method for producing foamable self-extinguishing carbon-containing modified polystyrene resin particles according to claim 12 are heated and pre-foamed to obtain foamed particles. A process for producing self-extinguishing carbon-containing modified polystyrene resin expanded particles, characterized in that A self-extinguishing carbon-containing modified polystyrene resin expanded particle obtained by the method for producing a self-extinguishing carbon-containing modified polystyrene resin expanded particle according to claim 13 is filled in a cavity of a mold, and then in the mold A method for producing a self-extinguishing carbon-containing modified polystyrene-based resin foam molded article, characterized by foam molding and then releasing the molded article from the mold.

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