JP2012176687A - Interior material for aircraft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interior material for an aircraft which has a high bulk foaming rate, and is excellent in strength, fire resistance, and heat resistance.SOLUTION: In the interior material for the aircraft, a foam molding body includes: 100 pts.mass of polyolefin based resin; 100-400 pts.mass of polystyrene based resin as resin components and 2-4 pts.mass of flame retardant with respect to 100 pts.mass of the resin component, and has 10-70 times the bulk foaming rate in the entire foam molding body, and the ratio of the bulk foaming rate Sf on the surface of the foam molding body and the bulk foaming rate If inside of the foam molding body satisfies a formula (1): 1.1≤If/Sf≤1.8.

Description

  The present invention relates to an aircraft interior material. More specifically, the present invention relates to an aircraft interior material having a high bulk foaming ratio and excellent in strength, flame retardancy and heat resistance.

  2. Description of the Related Art Conventionally, foam molded articles containing polystyrene resin, polypropylene resin, and the like as thermoplastic resin components are widely used as cushioning materials for packaging, structural members for automobiles, and the like because they are excellent in impact resistance, moldability, and the like.

  Further, when the foamed molded product is used as an automobile interior material, the foamed molded product is required to have not only the above-mentioned impact resistance and moldability but also high flame resistance in preparation for an accidental fire or the like. For this reason, for example, JP 2008-75076 A (Patent Document 1) describes a foamed molded article containing a specific flame retardant and a flame retardant aid as a foamed molded article having high flame retardancy.

JP 2008-75076 A

  At present, from the viewpoint of weight reduction and cost reduction, in addition to the above physical properties, higher foaming and lower specific gravity are desired for foamed molded products. However, when the foamed molded product is further increased in magnification, the hardness of the surface of the foamed molded product decreases in inverse proportion to the bulk foaming ratio, and desired physical properties such as strength may not be obtained depending on the application.

  In particular, when a foamed molded product is used as an aircraft interior material, the foamed molded product has a greater load due to the human body, cargo, etc., or a longer period of time under high temperature and humidity conditions than packaging cushioning materials, etc. May be placed underneath. In this case, the foamed molded article having a higher magnification loses flexibility, thereby causing deformation and change in magnification, and obtaining desired physical properties such as impact resistance, strength, and heat resistance required for the foamed molded article. May not be possible.

  On the other hand, the conventional foamed molded article and the one described in the cited reference 1 may exhibit a certain level of foamability, flame retardancy, etc. in such a case, but foam that can be used as an aircraft interior material. The molded article, that is, a foamed molded article having a high bulk foaming ratio and excellent in strength, flame retardancy and heat resistance, was not satisfactory. Specifically, it was not always satisfactory from the viewpoint of a foamed molded product that satisfies the vertical combustion test in Appendix F of Part III, Appendix III, Air Quality Examination Guidelines, Ministry of Land, Infrastructure, Transport and Tourism.

  Therefore, in view of these problems, even when used as an aircraft interior material, the bulk foaming ratio is high enough to be used, and the strength, flame retardancy and heat resistance are excellent. There is a need to provide foam molded articles.

Thus, according to the present invention, the resin component is a foamed molded article containing 100 parts by mass of a polyolefin resin and 100 to 400 parts by mass of a polystyrene resin,
The foamed molded product includes 2 to 4 parts by mass of a flame retardant with respect to 100 parts by mass of the resin component, and has a bulk foaming ratio of 10 to 70 times in the entire foamed molded product,
The ratio of the bulk foaming ratio Sf of the surface layer of the foamed molded product to the bulk foaming ratio If inside thereof is represented by the following formula (1):
1.1 ≦ If / Sf ≦ 1.8 (1)
An aircraft interior material characterized by satisfying the above is provided.

  According to the present invention, it is possible to obtain an aircraft interior material having a high bulk foaming ratio and excellent strength, flame retardancy, and heat resistance.

Moreover, according to this invention, a foaming molding is following formula (2):
−0.95X + 90 ≦ Y ≦ 100 (2)
(In the formula, X is the bulk expansion ratio of the entire foamed molded product, and Y is the surface hardness (CS hardness)).
In the case of satisfying, since the surface hardness and the bulk foaming ratio can be adjusted at a high level, the bulk foaming ratio is high, the flame retardancy and heat resistance are excellent, and a higher strength aircraft interior material can be obtained. .

  In addition, according to the present invention, it is also possible to obtain an aircraft interior material that satisfies the vertical combustion test of Appendix F of Part III of the Air Station Air Quality Examination Guidelines, Ministry of Land, Infrastructure, Transport and Tourism.

  Further, according to the present invention, when the foamed molded product has a heating dimensional change rate of 1.0% or less in absolute value after heating at 80 ° C. for 168 hours in accordance with JIS K6767: 1999K, Method B, Since a lower heating dimensional change rate after heating can be obtained, an aircraft interior material having a high bulk foaming ratio, excellent strength and flame retardancy, and excellent heat resistance can be obtained.

  In addition, according to the present invention, when the flame retardant is mainly composed of tris (2,3-dibromopropyl) isocyanurate, the flame retardant having a high flame retardant effect is included, and thus the bulk foaming ratio is high and the strength is increased. In addition, it is possible to obtain an aircraft interior material having excellent heat resistance and flame retardancy.

A feature of the present invention is a foamed molded article containing 100 parts by mass of a polyolefin resin and 100 to 400 parts by mass of a polystyrene resin as a resin component,
The foamed molded product includes 2 to 4 parts by mass of a flame retardant with respect to 100 parts by mass of the resin component, and has a bulk foaming ratio of 10 to 70 times in the entire foamed molded product,
The ratio of the bulk foaming ratio Sf of the surface layer of the foamed molded product to the bulk foaming ratio If inside thereof is represented by the following formula (1):
1.1 ≦ If / Sf ≦ 1.8 (1)
It is an aircraft interior material that meets the requirements.

  In the present invention, the aircraft interior material means a cushioning material or the like used for the purpose of reducing the weight, imparting impact resistance, or the like inside an aircraft seat. Specifically, interior materials used in aircraft such as seat headrest pads, cushion pads, and table cores are meant.

  The foam molded article of the present invention is a foam molded article containing 100 parts by mass of a polyolefin resin and 100 to 400 parts by mass of a polystyrene resin as a resin component. For this reason, high heat resistance and impact resistance (strength) derived from the olefin resin can be easily introduced into the foam molded article. Further, rigidity derived from polystyrene resin and high foamability can be easily introduced. Therefore, the foamed molded product of the present invention is a foamed molded product having both characteristics suitably.

  Moreover, the foaming molding of this invention is also a foaming molding containing 2-4 mass parts of flame retardants with respect to 100 mass parts of said resin components. For this reason, the foaming molding of this invention can have high flame retardance, maintaining desired physical properties, such as a high bulk foaming magnification, intensity | strength, and heat resistance.

  On the other hand, the foamed molded product of the present invention has a bulk foaming ratio of 10 to 70 times in the whole foamed molded product. For this reason, a foaming molding can have sufficient heat resistance, heat insulation, etc. which can be used as an aircraft interior material.

Furthermore, the ratio between the bulk foaming ratio Sf of the surface layer of the foamed molded product and the bulk foaming ratio If inside thereof is expressed by the following formula (1):
1.1 ≦ If / Sf ≦ 1.8 (1)
In order to satisfy the above, the foamed molded article of the present invention has a structure in which the internal bulk foaming ratio is higher than the bulk foaming ratio of the surface layer.

  For this reason, it is possible to introduce many high-hardness low-foaming sites that are excellent in impact resistance and the like into the surface of the foam-molded product, and on the other hand, many high-foamed sites that can be expected to have a high bulk foaming ratio inside the foam-molded product. Can be introduced. Therefore, the foamed molded product of the present invention has high strength and can maintain a high bulk foaming ratio.

  In the present invention, the surface layer and the inside of the foam-molded product are 1/3 of the thickness from any part having a thickness of at least 20 mm or more and a horizontal surface of 30 mm × 30 mm or more including the skin. When a cube whose length is one side is divided into three equal parts in the thickness direction, the upper and lower divided pieces, including the skin of the foam molded body, of the three equally divided cubes are called the surface layer and include the skin The divided piece sandwiched between the surface layers is referred to as the inside.

Accordingly, the foamed molded article of the present invention has a high bulk foaming ratio and is excellent in strength, flame retardancy and heat resistance, and therefore can be suitably used as an aircraft interior material.
Hereinafter, the foam molded article of the present invention will be described in detail.

<Method for producing foam molded article>
The foamed molded article of the present invention is
(1) producing composite resin particles containing a resin component and a flame retardant;
(2) producing expandable composite resin particles by impregnating the composite resin particles with a foaming agent;
(3) producing pre-expanded particles by pre-expanding the expandable composite resin particles;
(4) It can be obtained by foaming the pre-expanded particles.

<Composite resin particles>
In the present invention, the composite resin particle means a resin particle containing at least a resin component and a flame retardant. As long as the desired physical properties can be obtained, the composite resin particles may optionally contain a flame retardant aid, and the foamed molded article derived from the composite resin particles may optionally contain a flame retardant aid. Good. In addition, since the composite resin particle of the present invention contains a polyolefin resin and a polystyrene resin at a predetermined ratio as resin components, in the present invention, the foam molded article has high heat resistance and impact resistance derived from the olefin resin. (Strength) can be easily introduced, and rigidity derived from the polystyrene-based resin and high foamability can also be easily introduced. Note that the mass ratio of the monomer component, resin component, flame retardant, etc. used as the raw material is substantially the same as the mass ratio of the pre-foamed particles, foamed molded product, and the like.

  In the present invention, the polystyrene resin means a styrene homopolymer or a copolymer of styrene as a main component and another monomer copolymerizable with styrene. Here, styrene as a main component means that styrene accounts for 70% by mass or more of all monomers. Examples of other monomers include α-methylstyrene, p-methylstyrene, acrylonitrile, methacrylonitrile, acrylic acid, methacrylic acid, alkyl acrylate ester, alkyl methacrylate ester, divinylbenzene, and polyethylene glycol dimethacrylate. The In the present invention, alkyl means alkyl having 1 to 20 carbon atoms. In the present invention, a styrene homopolymer capable of stably pre-foaming expandable resin particles is preferable.

  In the present invention, the polyolefin resin is an olefin homopolymer or a copolymer of an olefin polymerizable monomer as a main component and another monomer copolymerizable with the olefin polymerizable monomer. Means. Here, the olefin-based polymerizable monomer as a main component means that the olefin-based polymerizable monomer occupies 70% by mass or more of all monomers.

Specifically, as the polyolefin resin, for example, branched low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer Polyethylene resins such as cross-linked products of these polymers;
Examples thereof include polypropylene resins such as propylene homopolymer, ethylene-propylene copolymer, propylene-1-butene copolymer, and ethylene-propylene-1-butene copolymer.

  In the present invention, since a higher level of heat resistance can be expected, a polypropylene resin is preferred as the polyolefin resin.

Moreover, as long as the desired physical properties are not affected, the polyolefin resin may be used alone or in combination of two or more. In addition, in the said illustration, it is preferable that low density is 0.91-0.94 g / cm < ³ >, and it is more preferable that it is 0.91-0.93 g / cm < ³ >. Preferably high density and is 0.95~0.97g / cm ^3, more preferably 0.95~0.96g / cm ^3. The medium density is an intermediate density between the low density and the high density.

  Unless the polyolefin-based resin and polystyrene-based resin of the present invention affect the desired physical properties, vinyl group, carbonyl group, aromatic group, ester group, ether group, aldehyde group, amino group, nitrile group, nitro group, respectively. Or a functional group such as a cross-linking agent having two or more vinyl groups, and these resins may be used alone or in combination of two or more.

  Similarly, the composite resin particles of the present invention may contain other resin components as long as they do not affect the desired physical properties. Examples of other resin components include known thermoplastic resins, thermosetting resins, and the like. Specifically, poly (meth) acrylic resins, polyphenylene ether resins, polycarbonate resins, and polyester resins including polylactic acid. Etc. In addition, (meth) acryl means acryl or methacryl.

  The polystyrene resin is contained in the composite resin particles in an amount of 100 to 400 parts by mass, preferably 125 to 240 parts by mass with respect to 100 parts by mass of the polyolefin resin. If the content of the polystyrene resin is more than 400 parts by mass, the polyolefin resin may be insufficient and the heat resistance may be inferior. On the other hand, when the amount is less than 100 parts by mass, the polystyrene resin may be insufficient and desired foamability may not be obtained.

  In addition, since the physical properties of both can be suitably introduced into the foamed molded article, the composite resin particles are a resin component that combines both in 100 parts by mass of the composite resin particles, preferably 70-100 parts by mass, more preferably. Contains 80-98.5 parts by mass. On the other hand, as a combination of a polyolefin resin and a polystyrene resin, a combination of a propylene homopolymer and a styrene homopolymer is preferable.

In the present invention, a known flame retardant can be used,
Tris (2,3-dibromopropyl) isocyanurate, tetrabromocyclooctane, hexabromocyclododecane, decabromodiphenyl ether, tribromophenyl allyl ether, tetrabromobisphenol A diallyl ether, tetrabromobisphenol A dipropyl ether, tetrabromobisphenol Brominated flame retardants such as A diglycidyl ether, tetrabromobisphenol A di (hydroxyethyl) ether, tetrabromobisphenol A bis (2,3-dibromopropyl ether);
Chlorinated flame retardants such as chlorinated paraffin, triphenyl chloride, diphenyl chloride, perchlorpentacyclodecane;
Examples include chlorine bromine-containing flame retardants such as 1,2-dibromo-3-chloropropane and 2-chloro-1,2,3,4-tetrabromobutane.

  A flame retardant may use only 1 type and may use it in combination of multiple types. In the present invention, it is preferable to use tris (2,3-dibromopropyl) isocyanurate as a main component because desired flame retardancy can be easily obtained. In the present invention, the main component means preferably 80% by mass or more, more preferably 90% by mass or more, based on the total amount of the flame retardant. The same applies to the flame retardant aid.

  The flame retardant of the present invention is compounded at a ratio of 2 to 4 parts by mass, preferably 2.2 to 3.8 parts by mass, more preferably 2.5 to 3.5 parts by mass with respect to 100 parts by mass of the resin component. Included in resin particles. When content of a flame retardant is less than 2 mass parts, the flame retardance of a foaming molding may fall. On the other hand, when the content of the flame retardant is more than 4 parts by mass, an amount more than necessary for imparting flame retardancy is included, and the production cost of the foamed molded product may increase. Furthermore, the change in the heating dimension of the foamed molded product may become large.

  In the present invention, known flame retardant aids may be used, such as 2,3-dimethyl-2,3-diphenylbutane, 3,4-dimethyl-3,4-diphenylhexane, dicumyl peroxide, cumene. And hydroperoxide. Only one type of flame retardant aid may be used, or a plurality of types may be used in combination. In the present invention, since desired flame retardancy can be easily obtained, it is preferable to use 2,3-dimethyl-2,3-diphenylbutane as a main component.

  The flame retardant aid of the present invention is preferably 0 to 2 parts by mass, more preferably 0 to 1.8 parts by mass, and still more preferably 0 to 1.5 parts by mass with respect to 100 parts by mass of the resin component. It is contained in the composite resin particles. When the content of the flame retardant aid is more than 2 parts by mass, an amount more than necessary for imparting flame retardancy is included, and the production cost of the foamed molded product may increase. Furthermore, the change in the heating dimension of the foamed molded product may become large.

  Moreover, as long as a desired foaming molding can be obtained, the composite resin particle may contain the other additive etc. Specific additives include coating agents, chain transfer agents, light stabilizers, ultraviolet absorbers, pigments, dyes, antifoaming agents, thickeners, heat stabilizers, leveling agents, lubricants, antistatic agents, etc. Can be mentioned.

<Method for producing composite resin particles>
The production method of the composite resin particles is not particularly limited, and any known method can be used. For example, suspension polymerization method, seed polymerization method and the like can be mentioned. The seed polymerization method is a method of obtaining composite resin particles by impregnating seed particles with a monomer component such as a styrene monomer in an aqueous medium and polymerizing them. In the present invention, it is preferable to use a seed polymerization method because it may be possible to easily produce foamed molded products having different bulk foaming ratios between the surface layer and the inside.
Hereinafter, the method for producing the composite resin particles of the present invention will be described with an example, but the present invention is not limited to these.

The composite resin particles of the present invention are, for example,
Step A of dispersing polyolefin resin particles, a styrene monomer, and a polymerization initiator in an aqueous suspension containing a dispersant;
Heating the obtained dispersion to a temperature at which the styrene monomer is not substantially polymerized to impregnate the polyolefin resin particles with the styrene monomer; and
When the melting point of the polyolefin-based resin particles is T ° C., a step C for obtaining the first particles by performing the first polymerization of the styrene monomer at a temperature of (T−10) ° C. to (T + 20) ° C. ,
Subsequent to the first polymerization step, the styrenic monomer and the polymerization initiator are added, and the temperature is set to (T-25) ° C. to (T + 10) ° C. A step D of impregnating a styrene monomer and performing a second polymerization to obtain resin particles;
It can be produced by impregnating the first particles in the second polymerization or the resin particles with a flame retardant and the like to obtain composite resin particles.
In this case, the mass ratio of the polyolefin resin and the styrene monomer is substantially the same as the resin component ratio in the foamed molded product, the pre-foamed particles, and the composite resin particles.

  Each of the processes A to E is performed, for example, when a well-known polymerization method such as a suspension polymerization method or a seed polymerization method of a polystyrene resin for producing bead-shaped polystyrene resin particles using a styrene monomer as a raw material. However, the production apparatus used is not limited to this.

(Process A)
Polyolefin resin particles are obtained by, for example, melting a polyolefin resin with an extruder and granulating the pellet by strand cutting, underwater cutting, hot cutting, etc., or directly pulverizing and pelletizing resin particles with a pulverizer can get. 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 average particle diameter of the polyolefin resin particles is preferably in the range of 0.5 to 1.5 mm, and more preferably in the range of 0.6 to 1.0 mm.

Examples of the dispersant include organic dispersants such as partially saponified polyvinyl alcohol, polyacrylate, polyvinyl pyrrolidone, carboxymethyl cellulose, and methyl cellulose;
Examples include inorganic dispersants such as magnesium pyrophosphate, calcium pyrophosphate, calcium phosphate, calcium carbonate, magnesium phosphate, magnesium carbonate, and magnesium oxide. Among these, an inorganic dispersant is preferable because a more stable dispersion state may be maintained. When using an inorganic dispersant, it is preferable to use a surfactant in combination. Examples of such surfactants include dodecyl benzene sulfonic acid soda and α-olefin sulfonic acid soda.

  It is preferable that the usage-amount of a dispersing agent is 0.1-5 mass parts with respect to 100 mass parts of aqueous suspension. Examples of the aqueous medium constituting the aqueous suspension include water, a mixture of water and a water-soluble solvent (for example, lower alcohols such as methanol and ethanol), and the like. The amount of the aqueous medium used is not particularly limited as long as a suspension can be formed.

As the polymerization initiator, a conventionally 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 Organic peroxides such as;
Examples include azo compounds such as azobisisobutyronitrile and azobisdimethylvaleronitrile. In addition, a polymerization initiator may be used independently or may be used together. It is preferable that the usage-amount of a polymerization initiator is 0.1-5 mass parts with respect to 100 mass parts of styrene-type monomers.

  Moreover, you may use a crosslinking agent. As a crosslinking agent, 2,2-di-t-butylperoxybutane, 2,2-bis (t-butylperoxy) butane, dicumyl peroxide, 2,5-dimethyl-2,5-di-t -Organic peroxides such as butylperoxyhexane. Examples of the method of adding the crosslinking agent include a method of directly adding the crosslinking agent to the polyolefin resin, a method of adding the crosslinking agent after dissolving it in a solvent, a plasticizer or a styrene monomer, and a method of adding the crosslinking agent to water. The method of adding after dispersing is mentioned. Among these, a method of adding a crosslinking agent after dissolving it in a styrene monomer is preferable.

  In order to impregnate the polyolefin resin particles, the styrene monomer can be added to the aqueous medium continuously or intermittently. It is preferable to gradually add the styrenic monomer to the aqueous medium.

(Process B)
In step B, the dispersion obtained in step A is heated to a temperature at which the styrene monomer is not substantially polymerized, and the styrene monomer is impregnated with the polyolefin resin particles. This heating temperature is preferably in the range of 45 to 70 ° C. When the heating temperature is less than 45 ° C., the impregnation of the styrene monomer is insufficient and a polystyrene polymer powder may be generated. On the other hand, when the heating temperature exceeds 70 ° C., polymerization may occur before the styrene monomer is sufficiently impregnated into the polyolefin resin particles. A more preferable heating temperature is in the range of 50 to 65 ° C.

(Processes C and D)
In step C and step D, the polymerization temperature is an important factor. Specifically, when the melting point of the polyolefin-based resin is T ° C, the polymerization temperature is in the range of (T-10) ° C to (T + 20) ° C in the step C (first polymerization), and the step D ( In the second polymerization, it is in the range of (T-25) ° C. to (T + 10) ° C.

  By performing polymerization in the above temperature range, composite resin particles having a large amount of polystyrene resin in the center and a large amount of polyolefin resin in the surface layer may be obtained in some cases. In this case, as a result of the uneven distribution of the polystyrene resin and the polyolefin resin, a foam molded article that retains the rigidity, foam moldability and chemical resistance by utilizing the advantages of the polyolefin resin and the polystyrene resin. Can be provided.

  When the polymerization temperature is lower than the above temperature range, the abundance of the polystyrene-based resin at the center is small, and a foamed molded article having good physical properties may not 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 polyolefin resin particles, so that a foam molded article having good physical properties cannot be obtained. There is. Moreover, if it becomes high, the superposition | polymerization equipment excellent in heat resistance will be needed.

  The reason for dividing the polymerization of the styrenic monomer into two stages, Step C and Step D, is that if a large amount of styrene monomer is impregnated into the polyolefin resin at once, the styrene monomer This is because the polyolefin resin is not sufficiently impregnated and remains on the surface of the polyolefin resin. If the polymerization process is divided into two stages, the styrene monomer is reliably impregnated in the center of the polyolefin resin in the process C, and the styrene monomer is impregnated in the process D toward the center of the polyolefin resin. Is done.

(Process E)
In step E, the first particles or the composite resin particles in the second polymerization are impregnated with a flame retardant. The temperature for the impregnation is preferably in the range of t ° C. to (t + 30) ° C., where t ° C. is the higher melting point of the flame retardant or any flame retardant auxiliary. When the temperature is lower than t ° C, the composite resin particles may not be sufficiently impregnated with the flame retardant or the flame retardant aid. On the other hand, if it is higher than (t + 30) ° C., an expensive polymerization facility having excellent heat resistance may be required. After step E, the reaction vessel is cooled, and the composite resin particles can be isolated from the aqueous medium to isolate the composite resin particles.

<Expandable composite resin particles>
The foamable composite resin particle means a resin particle having foaming performance in which a composite resin particle is impregnated with a foaming agent at a predetermined ratio.

  Various known foaming agents can be used as the foaming agent. Examples thereof include propane, n-butane (normal butane), isobutane, n-pentane (normal pentane), isopentane, industrial pentane, petroleum ether, cyclohexane, cyclopentane, flon, and halon alone or in a mixture. Of these, propane, n-butane, isobutane, n-pentane, isopentane, and cyclopentane, which can introduce greater foaming performance into the foamable composite resin particles, are preferred. A foaming agent may be used independently and may use 2 or more types.

  As a content rate of a foaming agent, it is preferable that it is 6-20 mass parts with respect to 100 mass parts of expandable composite resin particles. If the content of the foaming agent is less than 6 parts by mass, the foamability of the foamable composite resin particles may be lowered. When the foamability is lowered, it becomes difficult to obtain low-bulk density pre-expanded particles having a high bulk foaming ratio, and the foam-molded product obtained by in-mold molding of the pre-expanded particles has a lower fusion rate and is resistant to cracking. May decrease. On the other hand, when the amount exceeds 20 parts by mass, the bubble size in the pre-expanded particles tends to be excessive, and the moldability may be deteriorated and the strength characteristics such as compression and bending of the obtained foamed molded article may be deteriorated. A more preferable content of the blowing agent is in the range of 7.5 to 18 parts by mass.

  Moreover, you may use the foaming auxiliary agent which can pre-expand foamable composite resin particles more uniformly. Examples of the foaming aid include solvents such as toluene, xylene, cyclohexane, and d-limonene, and plasticizers (high-boiling solvents) such as diisobutyl adipate, glycerin, diacetylated monolaurate, and palm oil.

<Method for producing expandable composite resin particles>
The production method of the expandable composite resin particles is not particularly limited, and any known method can be used.
For example, a rotary mixer such as a V-type, C-type, or DC-type, in which composite resin particles are put into a sealed pressure-resistant container and flowed, and then a foaming agent is introduced to impregnate the composite resin particles with the foaming agent. Method;
Examples include a method of suspending the composite resin particles in an aqueous medium in a sealed pressure vessel equipped with a stirrer, then introducing a foaming agent, and impregnating the composite resin particles with the foaming agent.
The impregnation with the foaming agent is preferably performed at 50 to 140 ° C. for 0.5 to 6 hours. Further, the impregnation may be performed under atmospheric pressure or under pressure as long as a desired foamed molded article or the like can be obtained.

<Pre-expanded particles>
Pre-expanded particles mean resin particles obtained by heating and foaming expandable composite resin particles to a predetermined bulk expansion ratio. The pre-expanded particles of the present invention can be produced using a known pre-expand method. As an example of the pre-foaming method, the pre-foamed particles can be obtained by heating the foamable composite resin particles using a heating medium such as water vapor and pre-foaming at a predetermined bulk foaming ratio.

  The pre-expanded particles of the present invention preferably have a bulk expansion ratio of 10 to 70 times, more preferably 20 to 60 times. When the bulk foaming ratio is larger than 70 times, the strength and heat resistance of the obtained foamed molded product may be lowered. On the other hand, if it is less than 10 times, the weight of the obtained foamed molded product may increase.

  Further, the average particle diameter of the pre-expanded particles is preferably 8.4 mm or less, and more preferably 6.0 mm or less. When the average particle diameter is larger than 8.4 mm, the filling property of the pre-expanded particles in the foam molding machine may be lowered, and the strength of the obtained foam molded product may be lowered.

<Aircraft interior materials (foam moldings)>
The foamed molded product of the present invention can be produced using a known foam molding method. For example, pre-expanded particles are filled in a mold and heated again. Next, the pre-foamed particles are foamed in-mold, the particles are thermally fused together, and cooled to obtain a foamed molded product. As the heating medium, water vapor having a gauge pressure of 0.05 to 0.45 MPa is preferably used, and the time for introducing water vapor is preferably 10 to 180 seconds.

  Further, since a foamed molded product satisfying the following formula (1) can be more easily produced, the foamed molded product of the present invention preferably has a gauge pressure P of 0.20 MPa <P <0.33 MPa, more preferably Foam molding is performed with water vapor in the range of 0.23 MPa <P <0.30 MPa. The gauge pressure P means a value indicated by a gauge pressure gauge provided in the foam molding machine. Moreover, the temperature, time, etc. at the time of a foaming process are also set suitably according to a use raw material and manufacturing equipment.

In the present invention, the ratio between the bulk foaming ratio Sf (times) of the surface layer of the foamed molded product and the bulk foaming ratio If (times) therein is expressed by the following formula (1):
1.1 ≦ If / Sf ≦ 1.8 (1)
In order to satisfy the above, the foamed molded article of the present invention has a structure in which the internal bulk foaming ratio is higher than the bulk foaming ratio of the surface layer. For this reason, it is possible to introduce many high-hardness low-foaming sites that are excellent in impact resistance and the like into the surface of the foam-molded product, and on the other hand, many high-foamed sites that can be expected to have a high bulk foaming ratio inside the foam-molded product. As a result, the foamed molded article of the present invention has a suitable hardness and a high bulk foaming ratio.

In addition, since a foamed molded article having even higher strength can be obtained, the following formula (3):
1.15 ≦ If / Sf ≦ 1.7 (3)
It is preferable to satisfy.

  On the other hand, since the desired bulk foaming ratio can be ensured, the apparent bulk foaming ratio X (bulk foaming ratio in the whole) of the foamed molded product is in the range of 10 to 70 times, and preferably in the range of 15 to 60 times. A range of 20 to 50 times is more preferable.

  In addition, since the desired strength can be ensured, the surface hardness (CS hardness) Y of the foam molded body of the foam molded body is preferably in the range of 23.5 to 100, and more preferably in the range of 42.5 to 100. .

Furthermore, since the surface hardness and the bulk foaming ratio can be adjusted at a higher level, the surface hardness (CS hardness) Y of the foamed molded product and the bulk foaming magnification X (times) of the entire foamed molded product are expressed by the following formula: (2):
−0.95X + 90 ≦ Y ≦ 100 (2)
Satisfying the following formula (4):
−0.90X + 90 ≦ Y ≦ 95 (4)
It is more preferable to satisfy the above.

  Conventionally, when a foam molded body having a uniform surface and internal foam expansion ratio does not have the required surface hardness, the bulk foam expansion ratio of the entire foam molded body must be lowered in order to obtain good surface hardness. There wasn't. However, when the foamed molded product of the present invention satisfies the formula (2) or (4), the surface hardness can be improved while maintaining a high bulk foaming ratio as the whole foamed molded product. In this case, according to the present invention, it is possible to provide a foamed molded article having excellent surface hardness and a high multiple compared to a foamed molded article having a substantially uniform bulk foaming ratio between the surface layer and the inside.

  Furthermore, the foamed molded product of the present invention may contain 0 to 1.5 parts by mass of a residual foaming agent in 100 parts by mass of the foamed molded product. In this case, since the flammability caused by the residual foaming agent can be suppressed, a foamed molded article having a high bulk foaming ratio, excellent strength and heat resistance, and more excellent flame retardancy can be obtained.

  On the other hand, since the foamed molded article of the present invention contains a flame retardant at a suitable ratio, it has excellent flame retardancy and heat resistance. For this reason, the foamed molded article preferably has an absolute value of 1.0% or less, more preferably 0.5% after heating at 80 ° C. for 168 hours, in accordance with JIS K6767: 1999K, method B. Has a dimensional change rate.

  In addition, the foamed molded product can satisfy the vertical combustion test of Appendix F, Part III of the Air Station Air Quality Examination Guidelines, Ministry of Land, Infrastructure, Transport and Tourism.

  Accordingly, the foamed molded article obtained by the present invention has a high bulk foaming ratio and is excellent in strength, flame retardancy and heat resistance, and therefore can be suitably used as an aircraft interior material.

EXAMPLES Hereinafter, although an Example is given and this invention is further demonstrated, this invention is not limited by these Examples. Various measurement methods and production conditions described in the examples will be described below.
<Pre-foaming conditions>
0.5 to 1.5 kg of foamable composite resin particles impregnated with a foaming agent was charged into a PSX40 prefoaming machine (manufactured by Kasahara Kogyo Co., Ltd.) preheated with water vapor, and the gauge pressure was 0.005 to 0.09 MPa while stirring. Steam is introduced at a setting, and pre-expanded particles are obtained by foaming to a predetermined bulk density (bulk foaming ratio) in 20 to 180 seconds.

<Bulk density and bulk foaming ratio of pre-foamed particles>
The weight (a) of about 5 g of pre-expanded particles is weighed to the second decimal place. Next, weighed pre-expanded particles in a 500 cm ³ graduated cylinder with a minimum memory unit of 5 cm ³ , and this is a round resin plate slightly smaller than the caliber of the graduated cylinder, with a width of about 1.5 cm at the center, The volume (b) of the pre-expanded particles is read by applying a pressing tool in which a rod-shaped resin plate having a length of about 30 cm is fixed upright, and the bulk density (g) of the pre-expanded particles is calculated according to the formula (a) / (b). / Cm ³ ). The bulk foaming ratio (times) is the reciprocal of the bulk density, that is, the formula (b) / (a).

<Bulk density and bulk foaming ratio of the entire foamed molded product>
The bulk density of the foam-molded product was determined by measuring the apparent volume (cm ³ ) (c) and weight (g) (d) of the foam-molded product obtained after foam molding, and using the formula (d) / (c) The bulk density (g / cm ³ ) of the foamed molded product is determined. If the shrinkage after molding is not taken into account, the apparent volume of the foam molded body is equal to the volume in the mold cavity at the time when the foam molded body is obtained, and can be calculated from the dimensions of the mold drawing. The bulk foaming ratio (times) is the reciprocal of the bulk density, that is, the formula (c) / (d).

<Surface layer of foam molded article, bulk foaming ratio inside>
A cube having a thickness of at least 20 mm or more and having a horizontal surface of 30 mm × 30 mm or more including the outer skin is divided into three equal parts in the thickness direction with a length of 1/3 of the thickness as one side. And cut. Of the cube divided into three equal parts, the upper or lower test piece including the skin of the foam-molded product as viewed from the thickness direction is taken as test piece A, and the central test piece is taken as test piece B. For example, when the thickness of the part arbitrarily selected from the foam molded body is 30 mm, the test piece A is a cube of 10 mm on one side including the skin of the foam molded body, and the test piece B is one side not including the skin of the foam molded body. It becomes a 10 mm cube.

  The bulk foaming ratio of this test piece A was measured, and the average value for a total of 10 points measured in the same manner was used as the bulk foaming ratio (Sf) of the surface layer of the foam molded article. Moreover, the bulk foaming magnification of the test piece B is measured, and the average value of 10 points measured in the same manner is defined as the bulk foaming magnification (If) inside the foamed molded product. However, when the thickness of the foam molded body is less than 20 mm, or when the horizontal surface including the surface is less than 30 mm × 30 mm, these numerical values can be reduced to a level that does not hinder measurement. Moreover, when it is difficult to measure a total of 10 points due to the shape of the foam molded article, the number of measurements can be reduced to a measurable number. The ratio of internal / surface layer (If / Sf) is calculated from the surface layer of the foamed molded article and the internal bulk foaming ratio.

<Surface hardness of foam molding>
The surface hardness of the foamed molded product is measured using an Asker rubber hardness meter CS type (push needle shape: height 2.54 mm, φ10 mm cylindrical shape) manufactured by Kobunshi Keiki Co., Ltd. as a measuring device. A foam hardness is at least 20 mm or more, and a CS hardness meter is installed at a part arbitrarily selected from a horizontal surface of 30 mm × 30 mm or more including the skin, and a weight of 5 kg is used so that a load is applied vertically. The surface hardness of the foamed molded product was measured by pressing a CS hardness meter against the surface of the test body for 5 seconds. Similarly, measurement for a total of 20 points is performed, and the average value is defined as the surface hardness of the foamed molded product. However, when the thickness of the foam molded body is less than 20 mm, or when the horizontal surface including the surface is less than 30 mm × 30 mm, these numerical values can be reduced to a level that does not hinder measurement. Moreover, when it is difficult to measure a total of 20 points due to the shape of the foam molded article, the number of measurements can be reduced to a measurable number.

In the present invention,
(1) When formula (2) is satisfied: Pass (○)
(2) When the expression (2) is not satisfied .. Fail (×)
Is determined.

<Heat dimensional change rate of foamed molded product>
Measured by the method B described in JIS K 6767: 1999K “Foamed Plastics-Polyethylene Test Method”. The test piece is 150 mm × 150 mm × 30 mm (thickness), and three straight lines are written in the center and parallel to each other in the vertical and horizontal directions at intervals of 50 mm, and a hot air circulating dryer at 80 ° C. After 168 hours, the product is taken out, left in a standard state for 1 hour, and the vertical and horizontal line dimensions are measured by the following formula.
S = (L1-L0) / L0 × 100
In the formula, S represents a heating dimensional change rate (%), L1 represents an average dimension (mm) after heating, and L0 represents an initial average dimension (mm).

In the present invention,
(1) When the absolute value of S is 1.0% or less: Pass (○)
(2) When the absolute value of S is higher than 1.0% .. Fail (×)
Is determined.

<Aircraft Bureau, Ministry of Land, Infrastructure, Transport and Tourism, Air Quality Examination Guidelines Part III, Appendix F, Vertical Combustion Test>
Based on the vertical combustion test in Appendix F of Part III of the Air Quality Examination Guidelines, Ministry of Land, Infrastructure, Transport and Tourism, flame retardant evaluation of foamed molded products is performed as follows.

<Flame retardant evaluation of foamed molded products>
At least three samples are subjected to the test and the results are averaged. A test piece of 85 mm × 350 mm × 13 mm is attached to a metal frame that fixes the two long sides and the upper side defined in Appendix F of the Ministry of Land, Infrastructure, Transport and Tourism Air Bureau Airworthiness Examination Guidelines Part III, and is supported vertically. Using a Bunsen or Tyryl burner with a nominal 0.95 cm inner diameter, adjusted to give a flame of 3.8 cm in height, center the lower side of the sample 1.9 cm above the top of the burner, Ignite the sample. At this time, the temperature at which the center of the flame is measured is 843 ° C. or higher with a thermocouple pyrometer. After applying the flame for 12 seconds, the fire source is removed and a pass / fail decision is made as follows.

In the present invention,
(1) The average combustion length is less than 20 cm, the average combustion time after removing the fire source is less than 15 seconds, and the average combustion time of the drops from the sample is less than 5 seconds after dropping. Case: ……………… Pass (○)
(2) If the above conditions are not met ... Fail (×)
Is determined.

Example 1
By supplying 2000 g of polypropylene resin (manufactured by Prime Polymer Co., Ltd., trade name “F-744NP”, melting point: 140 ° C.) to an extruder, melt-kneading and granulating pellets by strand cutting, spherical (egg) Polypropylene resin particles were obtained.
The polypropylene resin particles at this time were adjusted to 60 mg per 100 particles and an average particle diameter of about 1 mm.

Next, 800 g of the polypropylene 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 mixture is stirred and suspended in the aqueous medium. The mixture was made turbid and held for 10 minutes, and then heated to 70 ° C. to obtain an aqueous suspension.
Next, 340 g of a styrene monomer in which 0.7 g of dicumyl peroxide was dissolved in this suspension was dropped in 30 minutes. After dropping, the mixture was held for 30 minutes to allow the polypropylene resin particles to absorb the styrene monomer.
Next, the temperature of the reaction system was raised to 140 ° C., which is the same as the melting point of the polypropylene resin particles, and held for 2 hours, and the styrene monomer was polymerized (first polymerization) in the polypropylene resin particles.
Next, the reaction liquid of the first polymerization is set to 120 ° C. that is 20 ° C. lower than the melting point of the polypropylene resin particles, and 1.5 g of sodium dodecylbenzenesulfonate is added to this suspension, and then the polymerization initiator is used. 860 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 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, whereby modified polystyrene resin particles were obtained.
Thereafter, the temperature of the reaction system was set to 60 ° C., and 60 g of tris (2,3-dibromopropyl) isocyanurate (manufactured by Nippon Kasei Co., Ltd.) as a flame retardant and 2,3 as a flame retardant aid were added to this suspension. -30 g of dimethyl-2,3-diphenylbutane (manufactured by Kayaku Akzo Co., Ltd.) was added. After the addition, the temperature of the reaction system was raised to 130 ° C. and stirring was continued for 2 hours to obtain composite resin particles.

Next, it was cooled to room temperature, and the composite resin particles were taken out from the 5 L autoclave. 2 kg of the composite resin particles after removal and 2 L of water were again put into a 5 L autoclave with a stirrer, and 300 g of butane (isobutane: normal butane = 3: 7, mass ratio) as a blowing agent was injected into the 5 L autoclave with a stirrer. After the injection, the temperature was raised to 70 ° C. and stirring was continued for 4 hours.
Thereafter, the mixture was cooled to room temperature, taken out from the 5 L autoclave, dehydrated and dried, and expandable composite resin particles were obtained.
Next, the obtained expandable composite resin particles were pre-expanded at a bulk expansion ratio of 30 times to obtain pre-expanded particles.

Further, the pre-expanded particles obtained were left at room temperature for 1 day, and then filled into the cavity of a mold having a cavity of 400 mm × 300 mm × 30 mm, and 0.25 MPa of water vapor was applied to the mold for 60 seconds. It was introduced and heated, and then cooled until the maximum surface pressure of the foamed molded product was reduced 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 foamed molded article, the apparent bulk foaming ratio, the vertical combustion test, the CS hardness, the heating dimensional change rate, etc. in the whole foamed molded article, surface layer and inside were measured.

Example 2
A suspension containing modified polystyrene resin particles was obtained in the same manner as in Example 1.
Thereafter, the temperature of the reaction system was set to 60 ° C., and 80 g of tris (2,3-dibromopropyl) isocyanurate (manufactured by Nippon Kasei Co., Ltd.) as a flame retardant and 2,3 as a flame retardant aid in this suspension. -40 g of dimethyl-2,3-diphenylbutane (manufactured by Kayaku Akzo Co., Ltd.) was added. After the addition, the temperature of the reaction system was raised to 130 ° C. and stirring was continued for 2 hours to obtain composite resin particles. Next, expandable composite resin particles were obtained in the same manner as in Example 1.
The obtained expandable composite resin particles were pre-expanded at a bulk expansion ratio of 60 times to obtain pre-expanded particles.

Further, the pre-expanded particles obtained were left at room temperature for 1 day, and then filled into the cavity of a mold having a cavity of 400 mm × 300 mm × 30 mm, and 0.25 MPa of water vapor was applied to the mold for 60 seconds. It was introduced and heated, and then cooled until the maximum surface pressure of the foamed molded product was reduced 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.

  And using the obtained foaming molding, the apparent bulk foaming magnification in the whole foaming molding, the surface layer, and the inside, a vertical combustion test, CS hardness, and a heating dimensional change rate were measured.

Example 3
A suspension containing modified polystyrene resin particles was obtained in the same manner as in Example 1.
Thereafter, the temperature of the reaction system was set to 60 ° C., and 40 g of tris (2,3-dibromopropyl) isocyanurate (manufactured by Nippon Kasei Co., Ltd.) was added as a flame retardant to the suspension. The temperature was raised to 130 ° C. and stirring was continued for 2 hours to obtain composite resin particles. Next, expandable composite resin particles were obtained in the same manner as in Example 1.
The obtained expandable composite resin particles were pre-expanded at a bulk expansion ratio of 10 to obtain pre-expanded particles.

Further, the pre-expanded particles obtained were left at room temperature for 1 day, and then filled into the cavity of a mold having a cavity of 400 mm × 300 mm × 30 mm, and 0.25 MPa of water vapor was applied to the mold for 60 seconds. It was introduced and heated, and then cooled until the maximum surface pressure of the foamed molded product was reduced 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 foamed molded article, the apparent bulk foaming ratio, the vertical combustion test, the CS hardness, the heating dimensional change rate, etc. in the whole foamed molded article, surface layer and inside were measured.

Example 4
1000 g of polypropylene resin particles obtained in the same manner as in Example 1 was placed in 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 were added as an aqueous medium. The contents were stirred and suspended in an aqueous medium, held for 10 minutes, and then heated to 70 ° C. to obtain an aqueous suspension.
Next, 400 g of styrene monomer in which 0.8 g of dicumyl peroxide was dissolved was dropped into this suspension over 30 minutes. After dropping, the mixture was held for 30 minutes to allow the polypropylene resin particles to absorb the styrene monomer.
Next, the temperature of the reaction system is raised to 140 ° C., which is the same as the melting point of the polypropylene resin particles, and is maintained for 2 hours, and the styrene monomer is polymerized in the polypropylene resin particles (first polymerization) to obtain the first. Obtained particles.

Next, the reaction liquid for the first polymerization was set to 120 ° C., which is 20 ° C. lower than the melting point of the polypropylene resin particles. Thereafter, 1.5 g of sodium dodecylbenzenesulfonate is added to the suspension, and then 600 g of a styrene monomer in which 3 g of dicumyl peroxide is dissolved is added dropwise over 3 hours to be absorbed by the polypropylene resin particles. The polymerization (second polymerization) was carried out.
After completion of 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 modified polystyrene resin particles.
Thereafter, the temperature of the reaction system was set to 60 ° C., and 40 g of tris (2,3-dibromopropyl) isocyanurate (manufactured by Nippon Kasei Co., Ltd.) as a flame retardant and 2,3 as a flame retardant aid in this suspension. -20 g of dimethyl-2,3-diphenylbutane (manufactured by Kayaku Akzo) was added. After the addition, the temperature of the reaction system was raised to 130 ° C. and stirring was continued for 2 hours to obtain composite resin particles.

Next, it was cooled to room temperature, and the composite resin particles were taken out from the 5 L autoclave. 2 kg of the composite resin particles after removal and 2 L of water were again put into a 5 L autoclave with a stirrer, and 300 g of butane (isobutane: normal butane = 3: 7, mass ratio) as a blowing agent was injected into the 5 L autoclave with a stirrer. After the injection, the temperature was raised to 70 ° C. and stirring was continued for 4 hours.
Thereafter, the mixture was cooled to room temperature, taken out from the 5 L autoclave, dehydrated and dried, and expandable composite resin particles were obtained.
Next, the obtained expandable composite resin particles were pre-expanded at a bulk expansion ratio of 30 times to obtain pre-expanded particles.

Further, the pre-expanded particles obtained were left at room temperature for 1 day, and then filled into the cavity of a mold having a cavity of 400 mm × 300 mm × 30 mm, and 0.25 MPa of water vapor was applied to the mold for 60 seconds. It was introduced and heated, and then cooled until the maximum surface pressure of the foamed molded product was reduced 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 foamed molded article, the apparent bulk foaming ratio, the vertical combustion test, the CS hardness, the heating dimensional change rate, etc. in the whole foamed molded article, surface layer and inside were measured.

Example 5
400 g of the polypropylene resin particles obtained in the same manner as in Example 1 was placed in 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 were added as an aqueous medium and stirred to obtain an aqueous medium. The suspension was suspended for 10 minutes and then heated to 70 ° C. to obtain an aqueous suspension.
Next, 200 g of a styrene monomer in which 0.4 g of dicumyl peroxide was dissolved in this suspension was dropped over 30 minutes. After dropping, the mixture was held for 30 minutes to allow the polypropylene resin particles to absorb the styrene monomer.
Next, the temperature of the reaction system is raised to 140 ° C., which is the same as the melting point of the polypropylene resin particles, and is maintained for 2 hours, and the styrene monomer is polymerized in the polypropylene resin particles (first polymerization) to obtain the first. Obtained particles.

Next, the reaction liquid for the first polymerization was set to 120 ° C., which is 20 ° C. lower than the melting point of the polypropylene resin particles. Thereafter, 1.5 g of sodium dodecylbenzenesulfonate was added to the suspension, and 1400 g of a styrene monomer in which 4.8 g of dicumyl peroxide was dissolved was dropped over 6.5 hours. Polymerization (second polymerization) was performed while absorbing the particles.
After completion of 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 modified polystyrene resin particles.
Thereafter, the temperature of the reaction system was set to 60 ° C., and 80 g of tris (2,3-dibromopropyl) isocyanurate (manufactured by Nippon Kasei Co., Ltd.) as a flame retardant and 2,3 as a flame retardant aid in this suspension. -40 g of dimethyl-2,3-diphenylbutane (manufactured by Kayaku Akzo Co., Ltd.) was added. After the addition, the temperature of the reaction system was raised to 130 ° C. and stirring was continued for 2 hours to obtain composite resin particles.

Next, it was cooled to room temperature, and the composite resin particles were taken out from the 5 L autoclave. 2 kg of the composite resin particles after removal and 2 L of water were again put into a 5 L autoclave with a stirrer, and 300 g of butane (isobutane: normal butane = 3: 7, mass ratio) as a blowing agent was injected into the 5 L autoclave with a stirrer. After the injection, the temperature was raised to 70 ° C. and stirring was continued for 4 hours.
Thereafter, the mixture was cooled to room temperature, taken out from the 5 L autoclave, dehydrated and dried, and expandable composite resin particles were obtained.
Next, the obtained expandable composite resin particles were pre-expanded at a bulk expansion ratio of 60 times to obtain pre-expanded particles.

Further, the pre-expanded particles obtained were left at room temperature for 1 day, and then filled into the cavity of a mold having a cavity of 400 mm × 300 mm × 30 mm, and 0.25 MPa of water vapor was applied to the mold for 60 seconds. It was introduced and heated, and then cooled until the maximum surface pressure of the foamed molded product was reduced 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 foamed molded article, the apparent bulk foaming ratio, the vertical combustion test, the CS hardness, the heating dimensional change rate, etc. in the whole foamed molded article, surface layer and inside were measured.

Comparative Example 1
A suspension containing modified polystyrene resin particles was obtained in the same manner as in Example 1.
Thereafter, the temperature of the reaction system was set to 60 ° C., and 36 g of tris (2,3-dibromopropyl) isocyanurate (manufactured by Nippon Kasei Co., Ltd.) as a flame retardant and 2,3 as a flame retardant aid in this suspension. -30 g of dimethyl-2,3-diphenylbutane (manufactured by Kayaku Akzo Co., Ltd.) was added. After the addition, the temperature of the reaction system was raised to 130 ° C. and stirring was continued for 2 hours to obtain composite resin particles. Next, expandable composite resin particles were obtained in the same manner as in Example 1.
The resulting expandable composite resin particles were pre-expanded at a bulk expansion ratio of 30 times to obtain pre-expanded particles.

  Further, the pre-expanded particles obtained were left at room temperature for 1 day, and then filled into the cavity of a mold having a cavity of 400 mm × 300 mm × 30 mm, and 0.25 MPa of water vapor was applied to the mold for 60 seconds. It was introduced and heated, and then cooled until the maximum surface pressure of the foamed molded product was reduced to 0.001 MPa to obtain a foamed molded product.

  Then, using the obtained foamed molded article, the apparent bulk foaming ratio, the vertical combustion test, the CS hardness, the heating dimensional change rate, etc. in the whole foamed molded article, surface layer and inside were measured.

Comparative Example 2
In the same manner as in Example 2, expandable composite resin particles were obtained.
The obtained expandable composite resin particles were pre-expanded at a bulk expansion ratio of 45 times to obtain pre-expanded particles.

  Further, the pre-expanded particles obtained were left at room temperature for 1 day, and then filled in the cavity of a mold having a size of 400 mm × 300 mm × 30 mm. It was introduced and heated, and then cooled until the maximum surface pressure of the foamed molded product was reduced to 0.001 MPa to obtain a foamed molded product.

  Then, using the obtained foamed molded article, the apparent bulk foaming ratio, the vertical combustion test, the CS hardness, the heating dimensional change rate, etc. in the whole foamed molded article, surface layer and inside were measured.

Comparative Example 3
A suspension containing modified polystyrene resin particles was obtained in the same manner as in Example 5.
Thereafter, the temperature of the reaction system was set to 60 ° C., and 60 g of tris (2,3-dibromopropyl) isocyanurate (manufactured by Nippon Kasei Co., Ltd.) as a flame retardant and 2,3 as a flame retardant aid were added to this suspension. -30 g of dimethyl-2,3-diphenylbutane (made by Kayaku Akzo Co., Ltd.)
After the addition, the temperature of the reaction system was raised to 130 ° C. and stirring was continued for 2 hours to obtain composite resin particles.

Next, expandable composite resin particles were obtained in the same manner as in Example 1.
The obtained expandable composite resin particles were pre-expanded at a bulk expansion ratio of 70 times to obtain pre-expanded particles.

  Further, the pre-expanded particles obtained were left at room temperature for 1 day, and then filled into the cavity of a mold having a cavity of 400 mm × 300 mm × 30 mm, and 0.25 MPa of water vapor was applied to the mold for 60 seconds. It was introduced and heated, and then cooled until the maximum surface pressure of the foamed molded product was reduced to 0.001 MPa to obtain a foamed molded product.

  Then, using the obtained foamed molded article, the apparent bulk foaming ratio, the vertical combustion test, the CS hardness, the heating dimensional change rate, etc. in the whole foamed molded article, surface layer and inside were measured.

  In Table 1, the raw material seed | species and evaluation result of an Example and a comparative example are explained in full detail.

As shown in Table 1, the foam molded articles of Examples 1 to 5 contain 100 parts by mass of a polyolefin resin and 100 to 400 parts by mass of a polystyrene resin as a resin component, and with respect to 100 parts by mass of the resin component. And derived from composite resin particles containing 2 to 4 parts by mass of a flame retardant. Moreover, the foaming molding of Examples 1-5 has a bulk foaming magnification of 10 to 70 times in the whole foaming molding. Furthermore, in the foamed molded products of Examples 1 to 5, the ratio between the bulk foaming magnification Sf of the surface layer of the foamed molded product and the bulk foaming magnification If inside thereof is the following formula (1):
1.1 ≦ If / Sf ≦ 1.8 (1)
In order to satisfy the above, good results were obtained in the vertical combustion test, the heating dimensional change rate, and the CS hardness evaluation test results of Appendix F of the Air Station Air Quality Examination Guidelines Part III of the Ministry of Land, Infrastructure, Transport and Tourism.

  In Comparative Example 2 in which the ratio between the bulk foaming ratio Sf of the surface layer of the foam molded article and the bulk foaming ratio If inside thereof is smaller than that of the present invention, the bulk foaming ratio of the foam molded article is 10 times that of Example 2. Despite being low, only the same CS hardness could be exhibited. Furthermore, the heating dimensional change rate also increased and could not be satisfied within 1.0%. In addition, a foamed molded product having a ratio of the bulk foaming magnification Sf of the surface layer of the foamed molded product to the bulk foaming magnification If inside thereof larger than that of the present invention could not be obtained at this stage.

  When the bulk foaming ratio of the foamed molded product was larger than the range of the present invention, as shown in Comparative Example 3, the vertical combustion test of Appendix III of the Air Quality Examination Guidelines Part III, Ministry of Land, Infrastructure, Transport and Tourism could not be satisfied. . Furthermore, the heating dimensional change rate also increased and could not be satisfied within 1.0%. When the foam expansion ratio of the foamed molded product is smaller than the range of the present invention, the foamed molded product is heavy and inferior in light weight.

  When the amount of the flame retardant with respect to 100 parts by mass of the composite resin particles is larger than the range of the present invention, the cost of the foamed molded article increases. For example, in the case of an aircraft interior material, it is difficult to accept the cost. When the amount of flame retardant and flame retardant aid is less than the scope of the present invention with respect to 100 parts by mass of the composite resin particles, as shown in Comparative Example 1, the vertical combustion of the Ministry of Land, Infrastructure, Transport and Tourism, Air Station Air Resistance Examination Guidelines Part III Appendix F The test could not be satisfied.

  Accordingly, the foamed molded article obtained by the present invention has a high bulk foaming ratio and is excellent in strength, flame retardancy and heat resistance, and therefore can be suitably used as an aircraft interior material.

Claims (5)

As a resin component, it is a foamed molded article containing 100 parts by mass of a polyolefin resin and 100 to 400 parts by mass of a polystyrene resin,
The foamed molded product includes 2 to 4 parts by mass of a flame retardant with respect to 100 parts by mass of the resin component, and has a bulk foaming ratio of 10 to 70 times in the entire foamed molded product,
The ratio of the bulk foaming ratio Sf of the surface layer of the foamed molded product to the bulk foaming ratio If inside thereof is represented by the following formula (1):
1.1 ≦ If / Sf ≦ 1.8 (1)
Aircraft interior material characterized by satisfying The foamed molded product has the following formula (2):
−0.95X + 90 ≦ Y ≦ 100 (2)
(In the formula, X is the bulk expansion ratio of the entire foamed molded article, and Y is the surface hardness (CS hardness)).
The aircraft interior material according to claim 1, wherein:   The aircraft interior material according to claim 1 or 2, wherein the foamed molded product satisfies the vertical combustion test of Appendix F of Part III of the Air Bureau of the Ministry of Land, Infrastructure, Transport and Tourism Airworthiness Examination Guidelines.   The foamed molded product according to any one of claims 1 to 3, which has a heating dimensional change rate of 1.0% or less in absolute value after heating at 80 ° C for 168 hours in accordance with JIS K6767: 1999K method B. The aircraft interior material according to one.   The aircraft interior material according to any one of claims 1 to 4, wherein the flame retardant is mainly composed of tris (2,3-dibromopropyl) isocyanurate.