JP2005154691A - Expanded polystyrene-based resin molded article having cured surface layer and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an expanded polystyrene-based resin molded article having a surface of an improved mechanical strength and penetration resistance, and a method for producing the same. <P>SOLUTION: The expanded polystyrene-based resin molded article has a cured surface layer that is made by curing of a polymerizable resin composition composed of a component (A) and/or component (B), wherein, (A) is a polymerizable acrylate and/or methacrylate and (B) is a polymerizable oligomer, and the polymerizable resin composition may also contain a polymerization initiator (C). The surface property of the expanded polystyrene-based resin molded article is improved by curing the polymerizable resin composition coated on the surface of the expanded polystyrene-based resin molded article. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a foamed styrene resin molded article having improved surface characteristics and a method for producing the same.

  Conventionally, foamed styrenic resin molded products have excellent heat insulation and buffering characteristics, but due to their low density (light weight), the molded product surface is brittle and mechanical strength is low. Yes, it is easily scratched or destroyed by external friction or impact. Moreover, since dirt such as oil and dirt once used soaks into the foam surface, it cannot be removed by washing with water and is discarded or used only once. Furthermore, when the molded product is immersed in water, it is easy to contain water. Therefore, these defects are accepted and used in limited applications, and it is desired to solve these defects and expand the applications.

  As a conventional technique for eliminating these drawbacks, a molded body and a resin sheet are bonded together with a third substance such as an adhesive interposed therebetween. However, the number of processes increases and becomes a factor of high cost. In addition, since an adhesive or the like is used, the working environment is deteriorated and there are problems in occupational safety and health.

  In addition, techniques for integrally forming a foamable styrene resin and a resin sheet using the same mold have also been proposed (for example, Patent Document 1, Patent Document 2, and Patent Document 3). In this technique, if the sheet surfaces to be combined are flat, the molding is relatively easy and the adhesion to the sheet can be secured. However, this process is also complicated, causing a high cost. Further, a complicated molded product having deep drawing or the like has a problem in dimensional accuracy and adhesion, and is likely to generate wrinkles.

  Further, the resin sheet used is a thermoplastic resin such as polystyrene, polypropylene, ABS, etc., and the obtained characteristics depend on these resins and have limitations in solvent resistance, heat resistance, scratch resistance, and the like.

Japanese Patent Application Laid-Open No. 7-40358 JP-A-9-280594 Japanese Patent Laid-Open No. 2003-39471

  An object of the present invention is to provide a foamed styrene resin molded article having improved surface mechanical strength and penetration, and a method for producing the same.

  As a result of intensive studies in view of the above problems, the inventors have applied a polymerizable resin composition to the surface of a foamed styrene-based molded article and cured it to form a cured film, thereby forming a foamed styrene-based resin molding. The surface hardness, mechanical strength, flexibility, smoothness, aesthetics, water resistance, oil resistance, weather resistance, resistance, which were the conventional problems, while maintaining the excellent heat insulation and buffering properties of the product. The present inventors have found that the contamination property is improved and completed the present invention.

According to the present invention, the following foamed styrenic resin molded articles and the like are provided.
1. A foamed styrene-based resin molded article having a cured layer obtained by curing a polymerizable resin composition containing the following components (A) and / or (B) on the surface.
(A) Polymerizable acrylic ester and / or methacrylic ester (B) Polymerizable oligomer 2. The foamed styrene according to 1, wherein the polymerizable oligomer (B) is at least one selected from polyester acrylate, polyester methacrylate, epoxy acrylate, epoxy methacrylate, polyurethane acrylate, polyurethane methacrylate, and unsaturated polyester. Resin molded products.
3. 3. The foamed styrene resin molded article according to 1 or 2, wherein the polymerizable resin composition further contains (C) a polymerization initiator.
4). The polymerization initiator (C) is
(D) The foamed styrene resin molded article according to 3, which is a polymerization initiator and / or (E) a photopolymerization initiator composed of an organic peroxide and an accelerator.
5). A method for producing a foamed styrene-based resin molded article, wherein a cured layer is formed by applying the polymerizable resin composition according to any one of claims 1 to 4 to a surface and curing the composition.
6). A foamed styrenic resin characterized in that a cured layer is formed by applying a polymerizable resin composition containing the following components (A) and / or (B) and (D) to the surface and curing the composition. Manufacturing method of molded products.
(A) Polymerizable acrylic ester and / or methacrylic ester (B) Polymerizable oligomer (D) Polymerization initiator comprising an organic peroxide and an accelerator 7. A cured layer is formed by applying a polymerizable resin composition containing the following components (A) and / or (B) and (E) to the surface and curing the composition by irradiation with ultraviolet rays. A method for producing a foamed styrene resin molded product.
(A) Polymerizable acrylic ester and / or methacrylic ester (B) Polymerizable oligomer (E) Photopolymerization initiator8. A foamed styrenic resin characterized in that a cured layer is formed by applying a polymerizable resin composition containing the following components (A) and / or (B) to the surface and irradiating and curing with an electron beam. Manufacturing method of molded products.
8. (A) Polymerizable acrylic ester and / or methacrylic ester (B) Polymerizable oligomer A polymerizable resin composition for improving the surface of a foamed styrene-based resin molded article, comprising the following components (A) and / or (B):
(A) A drain pan comprising the foamed styrenic resin molded article according to any one of the polymerizable acrylic acid ester and / or methacrylic acid ester (B) polymerizable oligomer 10.1-4.
11. A bag comprising the foamed styrene resin molded product according to any one of 11.1 to 4.
12. A vehicle-mounted deck board including the foamed styrene resin molded product according to any one of 12.1 to 4.

  According to the present invention, a foamed styrenic resin molded article having excellent properties such as hardness, bending strength, solvent resistance, low water absorption, resistance to water leakage, and the like due to a cured film existing on the surface, and production thereof Can provide a method. Furthermore, the foamed styrenic resin molded product of the present invention and its manufacturing method can be manufactured at a low cost with a small number of processes, and there is no problem of occupational safety and health because it does not use conventional adhesives. do not do.

  Hereinafter, the foamed styrene resin molded article and the method for producing the same of the present invention will be described in detail.

First, the foamed styrene resin molded product of the present invention will be described.
The foamed styrene-based resin molded article of the present invention has a cured layer on the surface obtained by polymerizing a polymerizable resin composition containing the following components (A) and / or (B).
(A) Polymerizable acrylic ester and / or methacrylic ester (B) Polymerizable oligomer

  The foamed styrene resin molded product before forming the cured layer used in the present invention is not particularly limited, and a normal molded product can be used. Specifically, a conventional product obtained by pre-foaming known foamable styrene resin particles to a desired multiple and then heat-foam molding, or a styrene resin molded by extrusion foaming, Also good.

  As a method of heat foam molding, there is typically a method in which pre-foamed beads are steam molded in a mold. As a method of extrusion foaming, there is a method of putting a foamable styrene resin into an extruder and heat extrusion molding, or a method of separately putting a styrene resin and a foaming agent into an extruder and then coalescing and melting and extrusion molding, The present invention may be any molded product produced by these methods.

  In addition, the foamed styrene resin molded product includes those modified with acrylonitrile, methyl methacrylate, butadiene, butyl acrylate, ethylene, propylene and the like.

  The styrenic resin is a copolymer of polystyrene or styrene and a monomer copolymerizable therewith. Monomers that can be copolymerized with styrene include α-methylstyrene, styrene derivatives such as vinyltoluene or substituted products thereof, alkyl methacrylates such as methyl methacrylate, acrylonitrile, and olefins such as ethylene and propylene. The amount used is preferably 50% by mass or less based on the total amount of monomers, but this is not limited depending on the purpose. Mixtures of these are also included.

  As the blowing agent, aliphatic hydrocarbons such as propane, butane, pentane and hexane can be used. As a method for impregnating the styrene resin with these foaming agents, known techniques such as suspension polymerization or extrusion foaming can be employed.

  As acrylic acid ester or methacrylic acid ester (A) used in the polymerizable resin composition, methoxypolyethylene glycol acrylate, EO-added alkylphenol acrylate, isobornyl acrylate, dicyclopentenyl acrylate, dicyclopetenyl as monofunctional acrylate There are oxyethyl acrylate, dicyclopentanyl acrylate, isobornyl acrylate, etc., and polyfunctional acrylates such as polyethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, hexanediol diacrylate, nonanediol diacrylate, neo Pentyl glycol diacrylate, trimethylolpropane triacrylate, EO-added trimethylolpro Down triacrylate and tris (2-acryloyloxyethyl) iso shea cyanurate. Monofunctional methacrylates include EO-added alkylphenol methacrylate, isobornyl methacrylate, dicyclopentenyloxyethyl methacrylate, dicyclopentanyl methacrylate, pentamethylpiperidyl methacrylate, tetramethylpiperidyl methacrylate, methoxypolyethylene glycol methacrylate, etc. Polyethylene glycol dimethacrylate, dipropylene glycol dimethacrylate, tripropylene glycol dimethacrylate, hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polyethylene glycol dimethacrylate, ethylene oxide modified bisphenol A dimethacrylate, trimethylolpropane trimethacrylate There are EO-added trimethylolpropane trimethacrylate and the like. These compounds can be used alone or in combination.

  Furthermore, in addition to the acrylic ester and / or methacrylic ester (A), an appropriate polymerizable oligomer (B) can be used in the polymerizable resin composition depending on the purpose. The oligomer (B) can be used alone or in combination with the acrylic ester and / or methacrylic ester (A). Examples of the polymerizable oligomer that can be used in the present invention include polyester acrylate, polyester methacrylate, epoxy acrylate, epoxy methacrylate, polyurethane acrylate, polyurethane methacrylate, and unsaturated polyester. These compounds can be used alone or in combination. The molecular weight of the oligomer is desirably about 5000 or less.

  As for the above-mentioned acrylic ester, methacrylic ester or oligomer, it is necessary to select an optimum variety depending on the use of the final product, compatibility with the expanded styrene resin, and the curing rate.

  For example, when flexibility is required, EO-modified bisphenol A dimethacrylate is the main component. When hardness, solvent resistance, heat resistance, moisture absorption resistance, etc. are required, polyfunctional acrylate or methacrylate is used. A three-dimensional structure may be formed as a main component.

  Further, there is a difference in compatibility with the foamed styrene resin depending on the molecular structure of acrylate or methacrylate, and some low molecular weight acrylate or methacrylate having no polar group such as a hydroxyl group can dissolve the foamed styrene resin. On the other hand, when the molecule becomes large, the compatibility with the foamed styrene resin decreases. Therefore, an optimum blend should be selected in consideration of imparting appropriate adhesiveness with the foamed styrenic resin.

  Furthermore, there is a difference in the curing rate, that is, the reaction rate. Generally, the acrylate is higher than the methacrylate, and the polyfunctional acrylate or methacrylate is higher than the monofunctional one. A combination of these characteristics should be considered.

  Furthermore, the polymerizable resin composition can contain a polymerization initiator (C). In general, a radical generator can be used as the polymerization initiator (C). Although radical generators, such as an organic peroxide, can be used, what can generate radicals at room temperature includes a polymerization initiator (D) composed of an organic peroxide and an accelerator, a photopolymerization initiator (E), and the like.

  When the polymerization initiator (D) is included, the polymerizable resin composition can be cured at room temperature by generating radicals by mixing the organic peroxide and the accelerator. When the photopolymerization initiator (E) is contained, the polymerizable resin composition can be cured by generating radicals by irradiation with ultraviolet rays.

  Even if these polymerization initiators (C) are not included, the polymerizable resin composition of the present invention is directly irradiated with an electron beam to generate radicals in the molecule to cure the polymerizable resin composition. Can do. However, even if it is a case where it hardens | cures by irradiating an electron beam, a polymerization initiator (D) and / or a photoinitiator (E) may be included.

  The above curing methods can also be combined. For example, ultraviolet curing or electron beam curing can be combined with room temperature (room temperature) curing.

  Organic peroxides that are components of the polymerization initiator (D) include cumene hydroperoxide, methyl ethyl ketone peroxide, acetoacetate peroxide, benzoyl peroxide, lauryl peroxide, t-butylperoxy-2-ethylhexyl carbonate , T-butyl perbenzoate, azo compounds such as azobisisobutyronitrile, and the like can be used alone or in combination of two or more.

  As an accelerator which is a component of the polymerization initiator (D), an organic acid salt of cobalt, for example, a cobalt soap such as naphthenic acid or octylic acid is used. Cobalt soap is solid at room temperature and may be directly dissolved in methacrylate and / or acrylate, but cobalt soap may be used by dissolving in a solvent, and in this case, mineral terpene, toluene, xylene or the like can be selected as the solvent . The concentration is usually from 1 to 99% by mass, but preferably from 30 to 70% by mass.

  For example, an organic peroxide such as cumene hydroperoxide and benzoyl peroxide and a 50% by mass solution of a mineral terpene of cobalt naphthenate are mixed in a mass ratio of 1 to 0.1 to 1 to 20 to produce radicals. Can be generated.

  The organic peroxide alone is chemically stable at 70 ° C. or lower, so that it is difficult to generate radicals. However, when it is mixed with cobalt soap, a chemical reaction occurs rapidly even at room temperature. Here, the mass ratio of the organic peroxide and cobalt soap solution is usually within the above range, but the preferred mass ratio is 1 to 2. However, it is not limited to this blending ratio.

  The mixing ratio of the polymerization initiator (D) in the polymerizable resin composition is 0.05 to 10 parts by mass of the organic peroxide and 100% by mass of the accelerator with respect to 100 parts by mass of the component (A) and / or the component (B). 0.1-20 mass parts is preferable.

  As the photopolymerization initiator (E), α-hydroxyl ketones such as 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1propanone, 2-hydroxy-1- {4- (2 -Hydroxyethoxy) phenyl} -2-methyl-1-propanone, or a mixture thereof, methylbenzoyl formate as phenylglyoxylate, α-dimethoxy-α-phenylacetophenone as benzyldimethyl ketals, α-amino ketones 2-Benzyl-2- (dimethylamino) -1- {4- (4-morpholinyl) phenyl} -1-butanone, 2-methyl-1- {4- (methylthio) phenyl} -2- (4-morpholinyl) -1-propanone or a mixture thereof, monoacylphosphine (MA O) diphenyl as a compound (2,4,6- trimethylbenzoyl) - phosphine oxide, phosphine oxide, and phenylbis (2,4,6-trimethylbenzoyl) or the like are mentioned as bisacylphosphine (BAPO) such. These photopolymerization initiators are used alone or in admixture of two or more.

  The blending ratio of the photopolymerization initiator (E) in the polymerizable resin composition is preferably 0.1 parts by mass to 20 parts by mass with respect to 100 parts by mass of the component (A) and / or the component (B). More preferably, it is 2-10 mass parts. If it is less than 2 parts by mass, the amount of radical generation is small and it takes time to cure, and it is not industrial. If it exceeds 10 parts by mass, it is not economical and the coating surface is easily yellowed by the residue of the initiator. There is a risk of missing.

Next, the manufacturing method of the foaming styrene resin molded product of this invention is demonstrated.
The polymerizable resin composition used in the present invention can be usually produced by mixing each component. However, when the polymerization initiator (D) is prepared by mixing the organic peroxide and the accelerator, radicals are generated when the organic peroxide comes into contact with the accelerator, so that it is preferably applied immediately after the preparation. For example, it is applied within 90 minutes at room temperature. Moreover, when it contains a photoinitiator (E), it is preferable to prepare by avoiding direct sunlight.

  As described above, in order to cure the polymerizable resin composition, there are room temperature curing, ultraviolet curing, electron beam curing, and the like. In particular, room temperature curing, ultraviolet curing, and electron beam curing can be properly used depending on the characteristics.

  That is, when the thickness of the cured layer of the polymerizable resin composition formed on the surface of the foamed styrenic resin molded article is relatively thick, such as 500 μm or more, the polymerization method using the polymerization initiator (D) is also possible. Is suitable for coloring with dark pigments or dyes.

  The polymerization method by ultraviolet rays using the photopolymerization initiator (E) is performed when the thickness of the cured layer is 500 μm or less, when the polymerizable resin composition is transparent, or when the polymerizable resin composition is colorless or light-colored. It is suitable for coloring with other pigments or dyes.

  The polymerization method using an electron beam is suitable when the thickness of the cured layer is as thin as 500 μm or less, as in the case of ultraviolet rays, and when the polymerizable resin composition is colored with a dark pigment or dye. Furthermore, since this method does not require a polymerization initiator, there is an advantage that there is no coloring due to a decomposition product of the initiator.

  Among the above polymerization methods, the greatest feature using ultraviolet rays and electron beams is that the curing time is short.

The polymerizable resin composition suitable for the room temperature curing method is a polymerizable resin composition containing the following components (A) and / or (B) and (D).
(A) Polymerizable acrylic ester and / or methacrylic ester (B) Polymerizable oligomer (D) Polymerization initiator comprising organic peroxide and accelerator

  The polymerizable resin composition is cured in a short time by being placed in a drying room at 30 ° C. to 70 ° C. after being applied to the foamed styrene resin molded product. When the drying temperature exceeds 70 ° C., coupled with the reaction heat of radical polymerization, the foamed styrenic resin molded product becomes hot and the surface of the molded product swells, and the commercial value may be inferior. Curing proceeds even at temperatures below 30 ° C., but it takes a long time and is not industrial. When radical polymerization proceeds and curing is completed, the surface is hard and a smooth molded product is obtained. When cobalt soap is used, the molded product exhibits the unique color of cobalt soap. In addition to this natural color, various pigments or dyes may be added. Product value is improved by obtaining colorful molded products.

The polymerizable resin composition suitable for the curing method using ultraviolet rays is a polymerizable resin composition containing the following components (A) and / or (B) and (E).
(A) Polymerizable acrylic ester and / or methacrylic ester (B) Polymerizable oligomer (E) Photopolymerization initiator

  The curing method using ultraviolet rays is performed by applying a polymerizable resin composition to the surface of a foamed styrene resin molded product, and then laying one or more mercury or metal halide lamps of 30 W / cm to 200 W / cm on the molded product. Although it differs depending on the size of the molded product, it is preferable to pass it through an ultraviolet irradiation apparatus capable of generating the ultraviolet ray at a speed of 1 m to 30 m per minute, whereby radical polymerization can be completed quickly. Although a lamp that generates ultraviolet rays may be directed directly to the molded product, heat rays are also generated and irradiated from the high-voltage lamp in addition to ultraviolet rays, so that the molded product tends to swell and the appearance deteriorates. When covered with a cold filter or quartz glass on which various metals are vapor-deposited, the heat rays are absorbed by them and the expansion of the molded product is eliminated, which is effective. There is no limitation on the ultraviolet irradiation device, whether it is an electroded type or an electrodeless type.

  The foamed styrene resin molded product in the present invention may be colored other than white which is a normal natural color. The acrylate or methacrylate resin layer cured with ultraviolet rays is transparent, and can impart strength and aesthetics to a white or colored foamed styrene resin molded product.

  Even in the curing method using ultraviolet rays of the present invention, a colored molded article having a beautiful colored appearance can be obtained by adding a light-colored dye or pigment to the polymerizable resin composition and curing it. Usually, the dye or pigment is added in an amount of 0.1 to 5 parts by mass with respect to 100 parts by mass of the polymerizable resin composition. In this case, a metal halide lamp is preferable to a mercury lamp rather than a mercury lamp. A dark-colored dye or pigment is not suitable because it absorbs ultraviolet rays and the ultraviolet rays do not reach the applied resin deep layer, and thus polymerization does not proceed. In order to solve this, it is preferable to irradiate ultraviolet rays by combining an organic peroxide and cobalt soap with a photopolymerization initiator. In this case, the surface layer of the polymerizable resin composition is instantly cured by ultraviolet rays, and the resin composition inner layer is polymerized and cured by radicals generated from the organic peroxide.

The polymerizable resin composition suitable for the curing method using an electron beam is a polymerizable resin composition containing the following components (A) and / or (B).
(A) Polymerizable acrylic ester and / or methacrylic ester (B) Polymerizable oligomer

  The curing method using an electron beam is such that after applying the polymerizable resin composition of the present invention to the surface of a foamed styrene resin molded article, the molded article is subjected to an acceleration voltage of 100 to 300 kV, a beam current of 0.2 to 20 mA, a conveyance speed of 1 to It is preferable to perform radical polymerization and cure in a range of a total electron dose of 20 to 400 kGy under conditions of 20 m / min and an oxygen concentration of less than 100 ppm. In curing by electron beam irradiation, even when a dark dye or pigment is mixed with the polymerizable resin composition, polymerization is not inhibited, and a cured layer of an acrylate or methacrylate having a desired color can be provided.

  The method of applying the polymerizable resin composition to the surface of the foamed styrene resin molded product is any method such as coating using a brush or equipment, spraying with a spray gun, or immersing the molded product in the polymerizable resin composition. Is also possible. The surface of the molded article coated with the resin composition swells partially. In the swollen state, radical polymerization proceeds by irradiation with heat, ultraviolet light, or electron beam, and the adhesiveness between the cured layer and the foamed styrene resin molded article is improved due to partly grafting with the polystyrene resin.

  In addition, the viscosity of the polymerizable resin composition is preferably 200 mPa · s (25 ° C.) or more. When it is less than 200 mPa · s (25 ° C.), a molded product having unevenness or an inclined portion flows until it is cured, and a molded surface with a non-uniform thickness tends to be formed. Examples of a method for increasing the viscosity to solve these problems include dissolving 1 part by mass to 10 parts by mass of polystyrene or liquid paraffin in the polymerizable resin composition.

In order to obtain a molding surface having a more uniform thickness, it is also effective to add a thixotropic agent such as finely divided silicon dioxide.
When liquid paraffin is used as an additive, in addition to increasing the viscosity, a foamed styrene resin molded product having a hardened surface with no gloss can be obtained.

  In addition, depending on the purpose, the polymerizable resin composition may be a lower alcohol such as methanol or ethanol, a ketone such as acetone or methyl ethyl ketone, an ester such as ethyl acetate, an aliphatic hydrocarbon such as hexane or heptane, toluene, It can also be diluted with various solvents such as aromatic hydrocarbons such as styrene.

Example 1
(1) Manufacture of foamed styrene resin molded product (before cured layer formation) Expandable polystyrene beads (manufactured by Hitachi Chemical Co., Ltd., trade name: High Beads SSB-TX-7) (EPS) are pre-foaming machines (HBP manufactured by Hitachi Chemical Technoplant) -500), the foamed foams pre-foamed to a bulk foaming factor of 61, 51, 31 times (density 16.4, 19.6, 32.3 kg / m ³⁾ were aged at room temperature for 16 hours.
The pre-expanded particles were subjected to a steam pressure of 0 with a molding machine (VS-300 manufactured by Daisen Kogyo Co., Ltd.) equipped with a 6-plate mold having dimensions of 300 mm (length) x 50 mm (width) x 20 mm (thickness). Molding was performed at 0.08 Mpa to obtain six molded products of 60, 50, and 30 times (density 16.7, 20, and 33.3 kg / m ³ ), respectively.

(2) Preparation of polymerizable resin composition Cobalt naphthenate (trade name: Cobalt naphthenate CN-6 manufactured by Tokyo Fine Chemical Co., Ltd.) and cumene hydroperoxide (manufactured by NOF Corporation, trade name: Park Mill) 2 g of H-80) is mixed with 40 g of dicyclopentenyloxyethyl methacrylate (trade name: FANCYL FA-512M, manufactured by Hitachi Chemical Co., Ltd.) and 60 g of EO-modified bisphenol A dimethacrylate (product name: FANCYL FA-321M, manufactured by Hitachi Chemical Co., Ltd.). Stir well. Since radicals are generated when cobalt naphthenate and organic peroxide come into contact with each other, this mixed solution was applied to a foamed styrene resin molded article within 90 minutes at room temperature.

(3) Formation of hardened layer The above resin composition was coated with a brush and a baker applicator (BAP-, manufactured by Imoto Seisakusho Co., Ltd.) on one side of 300 mm (long) x 50 mm (width) of the foamed styrene resin molded product prepared in (1) above. 04) was applied so that the resin layer had a thickness of 50 microns. Similarly, samples A, B, and C were applied to the back surface and both side surfaces in the longitudinal direction so as to have a thickness of 50 microns, and left for 3 hours in a drying chamber at 40 ° C. for surface curing.
From the difference in molding quality before and after application, the amount of resin applied was 2.1 g.

Example 2
(1) Production of foamed styrene resin molded product (before formation of cured layer) Six foamed styrene resin molded plates having a density of 20 kg / m ³ were obtained in the same manner as in Example 1 (1).

(2) Preparation of polymerizable resin composition To 100 g of EO-modified bisphenol A dimethacrylate, 5 g of 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by Ciba Specialty Chemicals: trade name Irgacure 184) as a photopolymerization initiator was added and stirred. Dissolved.

(3) Formation of cured layer As in Example 1 (3), the resin composition was applied using a brush and a baker applicator so that the thickness of the resin layer became 50 microns on one side of 300 x 50 mm. The test specimen was prepared and polymerized by passing it through an ultraviolet irradiation device (manufactured by Nippon Batteries) equipped with two high-pressure mercury lamps covered with a cold filter at curing conditions of 80 W (220 mJ / cm ² ) and 10 m / min. Next, the back surface was similarly cured in the same amount and under the same conditions. This molded product sample was designated as D. The coating amount was 1.6 g.

Example 3
(1) Manufacture of foamed styrene-based resin molded product (before cured layer formation) Except for using acrylonitrile-modified expandable polystyrene beads (trade name: High Beads GR) (GR) manufactured by Hitachi Chemical Co., Ltd. instead of expandable polystyrene beads In the same manner as in Example 1 (1), six foamed styrene resin molded plates having a density of 20 kg / m ³ were obtained.

(2) Preparation of polymerizable resin composition 4 g of a mineral terpene solution of cobalt naphthenate and 2 g of cumene hydroperoxide in the same amount as in Example 1 (1), 50 g of dicyclopentenyloxyethyl methacrylate, EO-modified bisphenol A di The mixture was mixed with 40 g of methacrylate and 10 g of tris (2-acryloyloxyethyl) isocyanurate (trade name: FANCYL FA-731A, manufactured by Hitachi Chemical Co., Ltd.) and stirred well.
Further, 1 g of a black dye (trade name: Black SPAB8G-227, manufactured by Sumitomo Color Co., Ltd.) was added to this mixed solution and stirred well. This solution was applied within 90 minutes after preparation.

(3) Formation of cured layer In the same manner as in Example 1 (3), the polymerizable resin composition was applied to the acrylonitrile-modified foamed polystyrene molded plate prepared in (1) above using a brush and a baker applicator. A test body in which only one side of 300 mm × 50 mm was applied so as to have a thickness of 100 microns was prepared, and left in a drying room at 40 ° C. for 3 hours to be polymerized and cured. This molded product sample was designated E. This molded product was black and glossy. The coating amount was 1.6 g.

Example 4
(1) Manufacture of a foamed styrene-based resin molded product (before the cured layer was formed) Six acrylonitrile-modified foamed polystyrene molded plates having a density of 20 kg / m ³ were produced in the same manner as in Example 3 (1).

(2) Preparation of polymerizable resin composition 50 g of dicyclopentenyloxyethyl methacrylate in the same manner as the polymerizable resin composition of Example 3 (2) except that the cobalt naphthenate mineral terpene solution and cumene hydroperoxide were removed. And 40 g of EO-modified bisphenol A dimethacrylate and 10 g of tris (2-acryloyloxyethyl) isocyanurate were prepared.

(3) Formation of Cured Layer The polymerizable resin composition is placed in a spray gun (trade name: CREAMY 7S-12, manufactured by Kinki Seisakusho Co., Ltd.) on the acrylonitrile-modified expanded polystyrene molded plate prepared in (1) above. It set to 3 kg / cm < ² > and sprayed uniformly so that the thickness of a resin layer might be set to 50 microns using a baker applicator only on one side of 300 mm x 50 mm. The applied polymerizable resin composition is cured with an electron beam irradiator (Iwasaki Electric Co., Ltd.) at a pressurization voltage of 175 kV, a beam current of 2.9 mA, an oxygen concentration of less than 100 ppm, a transport speed of 2 m / min, and a total dose of 240 kGy. It was. This molded product sample was designated as F. The coating amount was 0.8 g.

Example 5
(1) Production of foamed styrene resin molded product (before formation of cured layer) Six foamed styrene molded plates having a density of 20 kg / m ³ were obtained in the same manner as in Example 1 (1).

(2) Preparation of polymerizable resin composition 100 g of a mixed solution was prepared in the same manner as in Example 4 (2). 1 g of the black dye used in Example 3 (2) was added to this mixed solution and mixed well.

(3) Formation of hardened layer It applied so that the thickness of the resin layer might be set to 50 microns using a brush and a baker applicator only on one side of 300 mm x 50 mm of the foamed styrene molded plate produced in the above (1). The applied polymerizable resin composition was cured under the same conditions as the electron beam irradiation in Example 4 (3). This molded product sample was designated as G. This molded product was a black glossy molded product similar to Sample E. The coating amount was 0.8 g.

Example 6
(1) Manufacture of a foamed styrene-based resin molded product (before forming a cured layer) Six foamed polystyrene molded plates of 20 kg / m ³ were obtained in the same manner as in Example 1 (1).

(2) Preparation of polymerizable resin composition To a mixed liquid of 40 g of dicyclopentenyloxyethyl methacrylate, 40 g of EO-modified bisphenol A dimethacrylate, and 20 g of tris (2-acryloyloxyethyl) isocyanurate, 1-hydroxy-cyclohexyl-phenyl- 3 g of ketone and 2 g of silicon dioxide (trade name: AEROSIL 200, manufactured by Nippon Aerosil Co., Ltd.) were added and mixed well to impart thixotropic properties.

(3) Formation of hardened layer The foamed polystyrene molded plate produced in (1) above is immersed in a 300 mm × 50 mm single side and four side surfaces in a mixed solution of the resin composition, and is pulled up and inclined at an angle of 45 degrees. The composition was cured by irradiation with ultraviolet rays under the same conditions as in Example 2 (3). Subsequently, the back surface was similarly immersed and cured under the same conditions. This molded product sample was designated as H. When the thickness of the molded product was measured with a caliper, it was almost uniform. The coating amount was 2.7 g.

Example 7
(1) Manufacture of foamed styrene-based resin molded product (before cured layer formation) Expandable polystyrene beads (trade name: High Beads EX-15, manufactured by Hitachi Chemical Co., Ltd.) (EX), Φ60mm foam extrusion machine with round die attached A 15-times foamed extruded sheet (density 66.7 kg / m ³ ) having a thickness of 5 mm and a width of 100 mm was prepared by a pressure bonding method at an extrusion temperature of 140 ° C. and a die temperature of 125 ° C. (made by Ikekai Steel), a width of 50 mm and a length of 300 mm. Disconnected.

(2) Preparation of polymerizable resin composition To 100 g of dicyclopentenyloxyethyl methacrylate, a mixture of cobalt naphthenate mineral turpentine and cumene hydroxyperoxide having the same composition as in Example 1 (2) was added to obtain a resin composition. Was made.

(3) Formation of cured layer Using a brush and a baker applicator under the same conditions as in Example 1 (3), a molded product coated on both sides so that the thickness of the resin layer is 50 microns is placed in a drying chamber at 40 ° C. It was allowed to stand for 3 hours for polymerization and curing. This molded product sample was designated as I. The coating amount was 1.5 g.

Example 8
(1) Production of foamed styrene-based resin molded product (before cured layer formation) Foamed particles pre-foamed to a bulk foaming factor of 61 times (density 16.4 kg / m ³ ) produced in Example 1 (1) for 16 hours Aged at room temperature. The pre-expanded particles were subjected to steam pressure with a molding machine (DAIYA KOGYO DAIYA-CVS1300L2) equipped with a mold having a size of 400 mm (length) x 330 mm (width) x 180 mm (depth) and a thickness of 25 mm. Molding was performed at 0.065 mPa to obtain six molded products (density 16.7 kg / m ³ ). The mass was 145 g per piece.

(2) Preparation of polymerizable resin composition In a mixed solution of 60 g of dicyclopentenyloxyethyl methacrylate, 30 g of EO-modified bisphenol A dimethacrylate, dicyclopentenyloxyethyl acrylate (trade name: FANCYL FA-512A, manufactured by Hitachi Chemical Co., Ltd.) Then, 10 g of 1-hydroxy-cyclohexyl-phenyl-ketone and 3 g of polystyrene (trade name: GP, manufactured by Hitachi Chemical Co., Ltd.) were added and dissolved by stirring. The viscosity of this solution was 430 mPa · s (25 ° C.).

(3) Formation of cured layer On the four inner surfaces of the expanded polystyrene resin container prepared in (1) above, the polymerizable resin composition is placed in a spray gun and set at an air pressure of 0.3 kg / cm ² , and a baker applicator is used. The resin layer was sprayed to a thickness of 50 microns. The applied molded product was cured at 120 W using a handy type ultraviolet irradiation device (manufactured by Nippon Batteries) equipped with a mercury lamp having an effective length of 125 mm. The curing time was 45 seconds. The thickness of the cured layer was almost uniform visually. This molded product was designated J. The mass was 166 g.

Example 9
(1) Production of foamed styrene-based resin molded product (before cured layer formation) Example 1 (1) except that methyl methacrylate-modified expanded polystyrene beads (trade name: High Beads AF, manufactured by Hitachi Chemical Co., Ltd.) (AF) were used. In the same manner as above, six molded sheets of foamed styrene resin having a density of 20 kg / m ³ were obtained.

(2) Preparation of polymerizable resin composition Naphthenic acid having the same composition as Example 1 (2) was added to a mixed solution of 60 g of dicyclopentenyloxyethyl methacrylate, 30 g of EO-modified bisphenol A dimethacrylate, and 10 g of dicyclopentenyloxyethyl acrylate. A mixture of cobalt mineral terpene solution and cumene hydroxyperoxide, 0.5 g of liquid paraffin having a viscosity of 400 mPa · s (25 ° C.) and 1 g of the black dye used in Example 3 (2) were added and dissolved by stirring to obtain a resin composition. A product was prepared.

(3) Formation of hardened layer Under the same conditions as in Example 1 (3), using a brush and a baker applicator, a molded product coated on both sides and both long sides so that the thickness of the resin layer is 50 microns. It was left to stand in a drying room at 40 ° C. for 3 hours, polymerized and cured. This molded product sample was designated as K. This molded product was black and had a heavy color with no gloss. The coating amount was 2.1 g.

Example 10
(1) Production of foamed styrene resin molded product (before cured layer formation) Six foamed polystyrene molded plates having a density of 20 kg / m ³ were obtained in the same manner as in Example 1 (1).

(2) Preparation of polymerizable resin composition Naphthenic acid having the same composition as Example 1 (2) was added to a mixed solution of 60 g of dicyclopentenyloxyethyl methacrylate, 30 g of EO-modified bisphenol A dimethacrylate, and 10 g of dicyclopentenyloxyethyl acrylate. A mixture of cobalt mineral terpene solution and cumene hydroxyperoxide, 5 g of 1-hydroxy-cyclohexyl-phenyl-ketone and 1 g of the black dye used in Example 3 (2) were added and dissolved by stirring.

(3) Formation of cured layer Four surfaces were surrounded with glass so that the 50 mm width of the molded product was the bottom, and 7.5 g of the polymerizable resin composition was poured into the glass. Under the same conditions as in Example 2 (3), the uppermost surface of this test body was cured by ultraviolet irradiation, and was further allowed to cure in a drying room at 40 ° C. for 3 hours to remove the glass. This molded product sample was designated L. This molded product was a black and glossy molded product. The thickness of the resin layer of this molded product was measured with a caliper and found to be 0.5 mm (500 microns).

Comparative Example 1
Molded polystyrene molded articles (density 16.7, 20, 33.3 kg / m ³ ) (60, 50, 30 times) obtained in Example 1 (1) without application of the polymerizable resin composition, respectively. Product samples M, N, and O were used.

Comparative Example 2
The molded product sample P was an acrylonitrile-modified expanded polystyrene molded plate obtained in Example 3 (1) without applying the polymerizable resin composition.

Comparative Example 3
The extrusion molded sheet obtained in Example 7 (1) without applying the polymerizable resin composition was used as a molded product sample Q.

Comparative Example 4
A molded polystyrene sample R was a foamed polystyrene container obtained in Example 8 (1) without applying a polymerizable resin composition.

Comparative Example 5
The molded product sample S was a methyl methacrylate-modified foamed polystyrene molded plate obtained in Example 9 (1) without application of the polymerizable resin composition.

Table 1 shows the evaluation results of the expanded polystyrene resin molded products obtained in Examples 1 to 10 and Comparative Examples 1 to 5. In addition, the method of characteristic evaluation in Table 1 is as follows.
(1) Surface hardness The surface hardness of the molded product was indicated by an indication value on the molded product side when a sensor of a polystyrene foam tester PFT-2 manufactured by Yoshida Seiki was pressed against the surface of the molded product. The lower the numerical value, the harder the hardness is, the minimum value is 20, and the maximum value is 80.

(2) Bending strength The bending strength according to JIS-A-9511 is shown. The bending strength of the molded product applied on one side was set so that the resin layer was on the lower side.
(3) Gasoline resistance, toluene resistance It carried out according to ASTM-D-543-56.
The evaluation was ○: no change, Δ: partial swelling, x: dissolution.

(4) Water absorption rate It was shown by the water absorption rate according to Class A of JIS-A-9511.
(5) Water leakage 20 l of water and 10 ml of red ink were placed in a molded product container and left for 24 hours. Leakage and bleeding were observed visually. The number of test samples was 5, and the results were expressed as fractions with the number as a numerator when leakage or bleeding occurred.

  The foamed styrenic resin molded article of the present invention is excellent in mechanical strength, solvent resistance, water absorption, etc., and various uses such as structural members, heat insulating materials, packing materials, cushioning materials, crafts, etc. Can be suitably used for automobile floor spacers, residential building materials, bathroom members, drain pans, containers, bags, in-vehicle deck boards, and the like.

Claims (12)

A foamed styrene-based resin molded article having a cured layer obtained by curing a polymerizable resin composition containing the following components (A) and / or (B) on the surface.
(A) Polymerizable acrylic ester and / or methacrylic ester (B) Polymerizable oligomer   The polymerizable oligomer (B) is at least one selected from polyester acrylate, polyester methacrylate, epoxy acrylate, epoxy methacrylate, polyurethane acrylate, polyurethane methacrylate, and unsaturated polyester. Expanded styrene resin molded product.   The foamed styrene resin molded article according to claim 1 or 2, wherein the polymerizable resin composition further contains (C) a polymerization initiator. The polymerization initiator (C) is
The foamed styrenic resin molded article according to claim 3, which is (D) a polymerization initiator comprising an organic peroxide and an accelerator and / or (E) a photopolymerization initiator.   A method for producing a foamed styrene-based resin molded article, wherein a cured layer is formed by applying the polymerizable resin composition according to any one of claims 1 to 4 to a surface and curing the composition. A foamed styrenic resin characterized in that a cured layer is formed by applying a polymerizable resin composition containing the following components (A) and / or (B) and (D) to the surface and curing the composition. Manufacturing method of molded products.
(A) Polymerizable acrylic ester and / or methacrylic ester (B) Polymerizable oligomer (D) Polymerization initiator comprising organic peroxide and accelerator A cured layer is formed by applying a polymerizable resin composition containing the following components (A) and / or (B) and (E) to the surface and curing the composition by irradiation with ultraviolet rays. A method for producing a foamed styrene resin molded product.
(A) Polymerizable acrylic ester and / or methacrylic ester (B) Polymerizable oligomer (E) Photopolymerization initiator A foamed styrenic resin characterized in that a cured layer is formed by applying a polymerizable resin composition containing the following components (A) and / or (B) to the surface and irradiating and curing with an electron beam. Manufacturing method of molded products.
(A) Polymerizable acrylic ester and / or methacrylic ester (B) Polymerizable oligomer A polymerizable resin composition for improving the surface of a foamed styrene-based resin molded article, comprising the following components (A) and / or (B):
(A) Polymerizable acrylic ester and / or methacrylic ester (B) Polymerizable oligomer   A drain pan comprising the foamed styrene resin molded product according to any one of claims 1 to 4.   A bag comprising the expanded styrenic resin molded product according to any one of claims 1 to 4.   The vehicle-mounted deck board comprised including the foaming styrene-type resin molded product as described in any one of Claims 1-4.