JP6204789B2 - Resin base for ball game machines - Google Patents

Description

  The present invention relates to a resin base for a ball game machine including a resin sheet for a base of a ball game machine.

  Currently, a transparent resin sheet is used in place of veneer plywood as a material for a base of a ball game machine such as a pachinko machine or a slot machine (hereinafter sometimes simply referred to as “game board”). As a device for making the ball game machine more interesting and attractive, it has been proposed to incorporate a liquid crystal display device, an LED lighting device (light emitting diode), etc. into a game board using the transparent resin sheet as a material. .

  A game board using a methacrylic resin sheet was initially mainly configured to visually recognize the entire liquid crystal, that is, the liquid crystal through the resin sheet. On the other hand, a configuration in which a partial liquid crystal, that is, a portion corresponding to the liquid crystal display portion at the center of the panel surface is cut out by an NC processing machine such as an NC router and the liquid crystal display portion is visually recognized without using a resin sheet, is currently mainstream. . The area of the cut end material (cutting material) generated at the time of manufacturing the game board as described above occupies about 1/2 to 2/3 of the resin sheet area before processing, but is currently effectively used. It has become a big problem.

  On the other hand, in the molding process of a thermoplastic resin, a manufacturing method is known in which mills and defective products are pulverized and reused effectively as a raw material. Particularly in the manufacture of extruded sheets, it is common practice to pulverize ear plates generated by trimming processing at both ends in the sheet width direction, defective plates generated during production condition adjustment, etc., and reuse them as part of the raw material. (For example, refer to Patent Document 1).

International Publication No. 2006/046638

  However, when using the pulverized recycled material, problems such as mixing of foreign matters and coloring due to repeated heat history also occur. In the case of a game board using a methacrylic resin or the like as the transparent resin sheet described in Patent Document 1, when a pachinko nail is driven into the game board, cracks caused by whitening or micro cracks occur around the nail There is. Furthermore, when processing a game board, holes such as pilot holes when nailing are made on the game board by an NC processing machine such as a multi-axis drilling machine or an NC router, or the game board is made into an arbitrary shape by router (trimming) Various processing such as cutting or cutting is performed, but in this processing step, the end surface of the resin sheet is melted by frictional heat and wound around the blade to reduce workability. is there.

  The present invention has been made in view of the above problems, and not only realizes effective use of resources, but also a ball game machine excellent in balance of optical characteristics, mechanical characteristics, cutting workability, and rendering effects as a game board. It is to provide a resin base for use.

  As a result of diligent research, the present inventors have found that non-standard products generated during sheet production (sheets that occur during sheet thickness adjustment, sheet thicknesses that deviate from the standard, sheets that occur during material switching, etc.), and bullets Finely grind the hollow material (sheet center) generated during the manufacture of gaming machine resin bases to a shape (size) that can be extruded, and return a certain amount of crushed product that does not cause quality problems when the sheet is extruded. (Rework), It has been found that the above-mentioned problem can be solved by using a resin base of a ball game machine. Furthermore, the hollowed out material that has been extruded once, or the milling material generated at the time of sheet production is finely pulverized to a size that can be extruded, and the pulverized product is returned (reworked) at the time of sheet extrusion, while maintaining the quality. The dispersion state of the rubber particles was greatly improved, and the rubber agglomerates at the time of obtaining the sheet were greatly lowered, the appearance was improved, and the impact resistance was improved. As described above, the present inventors have completed the present invention.

That is, the present invention is as follows.
[1]
As virgin material, methacrylic resin containing a multi-layer structure grains that Do acrylic rubber (A) 95 wt% to 40 wt% or more and,
As rework product contains an acrylic that Do rubber multi-layer structure grains, and the (A) methacrylic resin (B) different from the 5 wt% to 60 wt% or less and,
A methacrylic resin sheet containing
A resin base for a ball game machine, wherein the methacrylic resin sheet contains an acetone insoluble part of 15% by mass or more and 50% by mass or less.
[2]
The resin base for a ball game machine according to [1], wherein the methacrylic resin sheet has a yellowness (YI) of 4 or less at a sheet thickness of 10 mm.
[3]
As virgin material, a methacrylic resin containing a multi-layer structure grains that Do acrylic rubber (A),
As rework products, containing a multi-layer structure grains that Do from acrylic rubber, and with the methacrylic resin different from (A) (B),
A method for producing a resin base for a ball game machine comprising a methacrylic resin sheet containing
The step of preparing the methacrylic resin sheet by adding 5 parts by mass or more and 150 parts by mass or less of the component (B) with respect to 100 parts by mass of the component (A),
A method for producing a resin base for a ball game machine, wherein the methacrylic resin sheet contains an acetone insoluble part of 15% by mass or more and 50% by mass or less .

  The resin base for a ball game machine of the present invention not only realizes effective use of resources, but also has an excellent balance of optical characteristics, mechanical characteristics, cutting workability, and presentation effects as a game board.

  Hereinafter, a mode for carrying out the present invention (hereinafter also referred to as “the present embodiment”) will be described in detail. In addition, this invention is not limited to this embodiment, It can implement in various deformation | transformation within the range of the summary.

  The resin base for the ball game machine of the present embodiment includes 95% by mass or less and 40% by mass or more of methacrylic resin (A) containing the first multilayer structure particles made of acrylic rubber, and the second made of acrylic rubber. And a methacrylic resin sheet containing 5% by mass to 60% by mass of a methacrylic resin (B) different from (A). Furthermore, in the resin base for a ball game machine of the present embodiment, the methacrylic resin sheet contains an acetone insoluble portion of 15% by mass or more and 50% by mass or less. Since it is configured as described above, the resin base for the ball game machine of this embodiment not only realizes effective use of resources, but also optical characteristics, mechanical characteristics, cutting workability, and effects as a game board The balance can be excellent. As will be described in detail later, the component A corresponds to a virgin material, and the component B corresponds to a rework product.

(1) Methacrylic resin sheet In this specification, “resin base for a ball game machine” means one that has been subjected to various processes to finish the “methacrylic resin sheet” in this embodiment as a product. Here, the processing is not particularly limited, and examples thereof include outer peripheral cutting, inner peripheral cutting, and nail hole processing. Moreover, the methacrylic resin sheet in this embodiment has a methacrylic resin containing multilayer structure particles made of acrylic rubber. Examples of the methacrylic resin include methacrylic acid ester monomer (a1): 70 to 100% by mass and other monomer (a2) copolymerizable with (a1): 0 to 30% by mass ( Co) polymerized ones are preferred. More preferably, the component (a1) has a mass ratio of 80 to 99.9% by mass and the component (a2) has a mass ratio of 0.1 to 20% by mass, and more preferably, the component (a1) has a mass ratio of 90 to 99.5% by mass. %, Component (a2) is a mass ratio of 0.5 to 10% by mass, particularly preferably (a1) component is 92 to 99% by mass, and (a2) component is 1 to 8% by mass. .

  In addition, it is preferable that the methacrylic resin sheet in this embodiment is evaluated as transparent from the viewpoint of optical characteristics. Here, “transparent” means that the total light transmittance described later is 85% or more in a sheet thickness of 10 mm.

  The weight average molecular weight of the methacrylic resin in the present embodiment is not particularly limited, but is preferably 80,000 or more and 220,000 or less, and 90,000 or more and 200,000 or less from the viewpoints of extrudability, heat resistance, workability, and the like. Is more preferable. The weight average molecular weight can be measured by gel permeation chromatography (GPC). For example, the molecular weight of the peak of the chromatogram can be obtained using a calibration curve obtained from measurement of commercially available standard PMMA (polymethyl methacrylate) using tetrahydrofuran as the mobile phase. In addition, the said calibration curve can be produced using several standard PMMA from which a peak molecular weight differs, for example.

  The monomer (a1) that can be used in the methacrylic resin in the present embodiment is not particularly limited as long as the desired effect of the present embodiment can be achieved. Preferred examples include the following general formula (i): And the methacrylic acid ester monomers shown.

(In the formula (i), _{R 1} represents a methyl group. Also, _{R 2} is as. The _{R 2} to carbon atoms represents from 2 to 12 groups, preferably hydrocarbon group having 1 to 12 carbon atoms And may have a hydroxyl group on the carbon.)

  Preferable specific examples of the methacrylic acid ester monomer (a1) include, but are not limited to, methyl methacrylate, butyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, cyclohexyl methacrylate, methacrylic acid Examples thereof include phenyl acid, methacrylic acid (2-ethylhexyl), methacrylic acid (t-butylcyclohexyl), benzyl methacrylate, and methacrylic acid (2,2,2-trifluoroethyl). The methacrylic acid ester monomer (a1) may be used alone or in combination of two or more.

  In the present embodiment, the other monomer (a2) copolymerizable with the methacrylic ester monomer (a1) is an acrylate monomer represented by the following general formula (ii) Can be suitably used.

(R ₃ is a hydrogen atom, and R ₄ is a hydrocarbon group having 1 to 18 carbon atoms.)

  Preferred specific examples of the acrylate monomer include, but are not limited to, methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, 2-ethylhexyl acrylate, and the like. Can do.

  As the monomer (a2) suitably used in the present embodiment, in addition to those described above, unsaturated group-containing divalent carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, cinnamic acid, and the like Alkyl esters thereof (excluding acrylic acid and methacrylic acid); styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,4- Styrenic monomers such as dimethyl styrene, 3,5-dimethyl styrene, p-ethyl styrene, m-ethyl styrene, о-ethyl styrene, p-tert-butyl styrene, isopropenyl benzene (α-methyl styrene); 1 -Vinylnaphthalene, 2-vinylnaphthalene, 1,1-diphenylethylene, isopropenyltoluene, Aromatic vinyl compounds such as sopropenylethylbenzene, isopropenylpropylbenzene, isopropenylbutylbenzene, isopropenylpentylbenzene, isopropenylhexylbenzene, isopropenyloctylbenzene; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; maleic anhydride Unsaturated carboxylic acid anhydrides such as itaconic anhydride; maleimide, maleimide, N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N- (o-chlorophenyl) maleimide, N- N-substituted maleimides such as (m-chlorophenyl) maleimide, N- (p-chlorophenyl) maleimide and N-benzylmaleimide; amides such as acrylamide and methacrylamide; Nylon glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, etc. Esterified; Esterified hydroxyl group of two alcohols such as neopentyl glycol di (meth) acrylate and di (meth) acrylate with acrylic acid or methacrylic acid; Polyhydric alcohol such as trimethylolpropane and pentaerythritol Derivatives esterified with acrylic acid or methacrylic acid; polyfunctional monomers such as divinylbenzene can be mentioned.

  In the methacrylic resin sheet of this embodiment, for the purpose of improving particularly required characteristics such as heat resistance, optical characteristics, and workability, the above-described vinyl monomers may be added and copolymerized as appropriate.

  In addition, when using a polyfunctional monomer, when the handleability of the resin sheet obtained is considered, it is preferable that the usage-amount of a polyfunctional monomer shall be 0-0.5 mass%.

  In the present embodiment, specific examples of the other monomer (a2) that is particularly preferably used include methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, and 2-ethylhexyl acrylate. And acrylic acid esters such as methacrylic acid, acrylic acid, styrene, maleic anhydride, N-phenylmaleimide, N-cyclohexylmaleimide and the like. As the other monomer (a2), one of the above-described monomers may be used alone, or two or more thereof may be used. More preferred specific examples include acrylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, and 2-ethylhexyl acrylate.

  The method for producing the methacrylic resin in the present embodiment is not limited at all, and a known polymerization method can be used. The methacrylic resin sheet may be a multi-layer resin sheet composed of two or more layers.

(2) Multilayer structure particles comprising acrylic rubber particles The acrylic rubber particles in the present embodiment have at least a three-layer structure formed in the order of the center hard layer, soft layer, and outermost hard layer from the center of the particle. The particles can be said to have a multilayer structure. That is, a three-layer structure in which the soft layer covers the central hard layer and the outermost hard layer covers the soft layer can be exemplified. Moreover, in this embodiment, it is good also as a 4 layer structure which further has an intermediate | middle hard layer between a soft layer and an outermost hard layer as needed, and it is good also as a multilayer structure of 5 layers or more. Among them, a three-layer structure is preferable from the viewpoint of whitening and crack prevention. By blending the above acrylic rubber particles with a methacrylic resin sheet, when a pachinko nail is struck on a game board using the methacrylic resin sheet, it is possible to prevent whitening and cracking due to microcracks around the nail. it can.

  The material for the acrylic rubber particles is not particularly limited, and known acrylic rubber particles can be used. For example, JP-B-60-17406, JP-A-8-245854, JP-B55-27576, JP-B58-1694, JP-B59-36645, JP-B59-36646, Acrylic rubber particles described in JP-A-62-41241, JP-A-59-202213, JP-A-63-27516, JP-A-51-129449, JP-A-52-56150, etc. Can be used.

  Specific examples of the acrylic rubber particles include, but are not limited to, acrylic rubber particles such as the following (A), (I), and (U).

(A) Acrylic rubber particles obtained by the following steps (a) to (c):
(A) Emulsion polymerization of methyl methacrylate alone or a mixture of methyl methacrylate and a monomer copolymerizable therewith, and dispersion of a polymer mainly composed of methyl methacrylate and having a glass transition point of 25 ° C. or higher A first layer forming step of forming a liquid;
(B) Based on the total weight of the mixture, the product of the first layer forming step is mainly based on alkyl acrylate, and at least one of a monomer and a polyfunctional crosslinking agent copolymerizable therewith. A second layer formed by adding a mixture containing 5% by mass of a polyfunctional grafting agent and forming a copolymer having a glass transition point of 25 ° C. or lower when polymerized alone to effect emulsion polymerization A step, and (c) a product having the glass transition point of 25 ° C. or higher when polymerized alone on the product of the second layer forming step, methyl methacrylate or a single amount mainly composed thereof A third layer forming step in which a chain transfer agent is gradually increased in the body mixture and emulsion polymerization is performed in multiple stages.

  (A) At least one soft polymer layer containing a polymer having a polymer melting start temperature of 235 ° C. or higher and a glass transition temperature Tg of 25 ° C. or lower when polymerized alone in the inner layer, and an outermost layer And a hard polymer layer containing a polymer having a Tg of 50 ° C. or higher when polymerized alone, and an acrylic rubber particle comprising a coagulated powder obtained by coagulating an emulsion latex of an acrylic multilayer structure polymer. The ratio of fine powder having a particle size of 212 μm or less after drying to a mass of 212 μm or less and a pore volume of 5 μm or less measured by mercury intrusion of the solidified powder after drying is 0.7 cc per unit area Acrylic rubber particles that are:

(C) Acrylic rubber particles satisfying the following (d) to (j):
(D) 90 to 99% by mass of methyl methacrylate, 1 to 10% by mass of alkyl acrylate having 1 to 8 carbon atoms in the alkyl group, and allyl, methallyl of α, β-unsaturated carboxylic acid copolymerizable with these. Innermost hard layer polymer 25 to 45% by mass obtained by polymerizing a monomer mixture consisting of 0.01 to 0.3% by mass of at least one graft-bonding monomer selected from crotyl ester,
(E) In the presence of the innermost hard layer polymer, 70 to 90% by mass of n-butyl acrylate, 10 to 30% by mass of styrene, and allyl, methallyl of α, β-unsaturated carboxylic acid copolymerizable therewith, 35 to 45% by mass of a soft layer polymer obtained by polymerizing a monomer mixture consisting of 1.5 to 3.0% by mass of a graft-bondable monomer consisting of at least one selected from crotyl ester,
(F) In the presence of the polymer composed of the innermost hard layer and the soft layer, obtained by polymerizing a monomer mixture having 90 to 99% by mass of methyl methacrylate and having 1 to 8 carbon atoms in the alkyl group. It consists of 20 to 30% by mass of the outermost hard layer polymer,
(G) The mass ratio of soft layer polymer / (innermost hard layer polymer + soft layer polymer) is 0.45 to 0.57,
(H) A multilayer acrylic polymer having an average particle size of 0.2 to 0.3 μm, and when the multilayer acrylic polymer is further fractionated with acetone,
(I) The graft ratio is 20 to 40% by mass,
(J) The tensile elastic modulus of the acetone insoluble part is 1000 to 4000 kg / cm ² .

  As an acrylic rubber particle in this embodiment, what is marketed can be used. For example, “Rubber IR377 (trade name)”, “Rubber IR441 (trade name)” manufactured by Mitsubishi Rayon Co., Ltd. and the like can be mentioned.

(3) Acetone insoluble part (mass%)
In this embodiment, content of the acetone insoluble part of the acrylic rubber particles contained in the methacrylic resin sheet is 15% by mass or more and 50% by mass or less. By satisfying the above range, the resin base for the ball game machine of the present embodiment can ensure sufficient surface hardness, effectively prevent flaws from being attached, and ensure sufficient elastic modulus. Can do. The content of the acetone insoluble part is more preferably 19% by mass or more and 50% by mass or less, and still more preferably 19% by mass or more and 35% by mass or less, from the same viewpoint as described above. In addition, when the content of the acetone insoluble part is 19% by mass or more, the transparency (total light transmittance, yellowness), tensile elastic modulus, Charpy impact strength of the resin base for the ball game machine of the present embodiment. In particular, the suppression effect such as pencil hardness, whitening or cracking by nailing, cutting workability (preventing generation of burrs, chipping, etc.) and the like tend to be particularly excellent. On the other hand, when the content of the acetone insoluble part exceeds 50% by mass, it is not possible to secure a sufficient surface hardness of the resin base for a ball game machine, and not only the scratches are easily attached, but also a sufficient elastic modulus is obtained. In addition, the necessary holding power of the nail cannot be secured. In addition, when the content of the acetone insoluble part is less than 15% by mass, there are problems such as cracks generated when nailing, and cutting machinability adhering to the blade during cutting, resulting in reduced machinability. . Content of the said acetone insoluble part can be measured in the way as described in the Example mentioned later.

<Other resins>
In the present embodiment, a resin other than a methacrylic resin can be blended for the purpose of imparting characteristics such as rigidity, chemical resistance, and optical characteristics. Other resins are not particularly limited as long as the effects of the present embodiment can be exhibited. For example, polystyrene resins, syndiotactic polystyrene resins, ABS resins (acrylonitrile-butadiene-styrene resins). AS resin (acrylonitrile-styrene resin), BAAS resin (butyl acrylate-acrylonitrile-styrene resin), MBS resin (methyl methacrylate-butadiene-styrene resin), AAS resin (acrylonitrile-acrylic ester- Styrenic resin), biodegradable resins such as polylactic acid, alloys of polycarbonate-ABS resins, polycarbonate resins and the like. In particular, AS resins and BAAS resins are preferable from the viewpoint of further improving fluidity, and ABS resins, MBS resins, and polycarbonate resins are preferable from the viewpoint of further improving impact resistance.

  When the other resin is blended, the blending ratio is 0 to 60% by mass, more preferably 0 to 40% by mass, when the total of the methacrylic resin and the other resin of the present embodiment is 100% by mass. More preferably, it is 3 to 40% by mass, particularly preferably 3 to 30% by mass.

<Additives>
A predetermined additive may be added to the methacrylic resin sheet in the present embodiment from the viewpoint of imparting various characteristics such as rigidity and dimensional stability more favorably.

  Examples of the additives include, but are not limited to, various stabilizers such as antioxidants, ultraviolet absorbers, heat stabilizers, and light stabilizers; plasticizers (paraffinic process oil, naphthenic process) Oils, aromatic process oils, paraffins, organic polysiloxanes, mineral oils), flame retardants (eg, phosphorus compounds such as organic phosphorus compounds, red phosphorus, inorganic phosphates, halogens, silicas, silicones, etc.) Flame retardant aids (eg, antimony oxides, metal oxides, metal hydroxides, etc.), curing agents (diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, diethylaminopropylamine, 3,9-bis (3-Aminopropyl) -2,4,8,10-tetraoxaspiro [5,5] undecane, mensen Amines such as amine, isophoronediamine, N-aminoethylpiperazine, m-xylenediamine, m-phenylenediamine, diaminophenylmethane, diaminodiphenylsulfone, dicyandiamide, adipic acid dihydrazide, phenol novolac resin, cresol novolac resin, etc. Phenolic resins, liquid polymercaptan, polymercaptan such as polysulfide, maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl nadic anhydride, Pyromellitic anhydride, methylcyclohexene tetracarboxylic anhydride, dodecyl succinic anhydride, trimellitic anhydride, chlorendic anhydride, benzophenone tetracar Acid anhydrides, acid anhydrides such as ethylene glycol bis (anhydrotrimate)), curing accelerators (2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, imidazoles such as 2-phenyl-4-methylimidazole, organic phosphines such as triphenylphosphine and tributylphosphine, benzyldimethylamine, 2-dimethylaminomethyl) phenol, 2 , 4,6-Tris (diaminomethyl) phenol, tertiary amines such as tetramethylhexanediamine, triphenylphosphine tetraphenylborate, tetraphenylphosphonium tetraphenylborate, triethylaminetetraphenylbore Boron salts such as salts, 1,4-benzoquinone, 1,4-naphthoquinone, 2,3-dimethyl-1,4-benzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-1,4-benzoquinone, etc. Quinoid compounds, etc.), antistatic agents (eg polyamide elastomers, quaternary ammonium salts, pyridine derivatives, aliphatic sulfonates, aromatic sulfonates, aromatic sulfonate copolymers, sulfate esters, Partial alcohol esters, alkyldiethanolamines, alkyldiethanolamides, polyalkylene glycol derivatives, betaines, imidazoline derivatives, etc.), conductivity imparting agents, stress relieving agents, mold release agents (alcohols, esters of alcohols and fatty acids, alcohols Esters with dicarboxylic acid, silicone oil, etc.), crystallization promotion , Hydrolysis inhibitors, lubricants (eg, higher fatty acids such as stearic acid, behenic acid, zinc stearate, calcium stearate, magnesium stearate, and metal salts thereof, higher fatty acid amides such as ethylene bisstearamide) , Impact imparting agents, slidability improvers (hydrocarbons such as low molecular weight polyethylene, higher alcohols, polyhydric alcohols, polyglycols, polyglycerols, higher fatty acids, higher fatty acid metal salts, fatty acid amides, fatty acids and fatty alcohols Esters, fatty acid and polyhydric alcohol full esters or partial esters, fatty acids and polyglycol full esters or partial esters, silicones, fluororesins, etc.), compatibilizers, nucleating agents, reinforcing agents, flow control agents , Dye (nitroso dye, nitro dye, azo dye, stilbene azo dye, Toymine dye, triphenylmethane dye, xanthene dye, acridine dye, quinoline dye, methine / polymethine dye, thiazole dye, indamine / indophenol dye, azine dye, oxazine dye, thiazine dye, sulfur dye, aminoketone / oxyketone dye, anthraquinone dye , Indigoid dyes, phthalocyanine dyes, etc.), sensitizers, colorants (titanium oxide, carbon black, titanium yellow, iron oxide pigments, ultramarine, cobalt blue, chromium oxide, spinel green, lead chromate pigments, cadmium Inorganic pigments such as pigments, azo lake pigments, benzimidazolone pigments, diazolide pigments, azo pigments such as condensed azo pigments, phthalocyanine pigments such as phthalicyanine blue and phthalocyanine green, isoindolinone pigments, quino Organic pigments such as phthalone pigments, quinacridone pigments, perylene pigments, anthraquinone pigments, perinone pigments, condensed polycyclic pigments such as dioxazine violet, scaly aluminum metallic pigments, used to improve weld appearance Spherical aluminum pigments, mica powder for pearl metallic pigments, other metallic pigments such as glass coated with inorganic polyhedral particles such as metal plating or sputtering), thickeners, anti-settling agents, anti-sagging agents , Fillers (glass fibers, fibrous reinforcing agents such as carbon fibers, glass beads, calcium carbonate, talc, clay, etc.), antifoaming agents (silicone defoaming agents, surfactants, polyethers, higher alcohols, etc.) Organic defoaming agents, etc.), coupling agents, light diffusing fine particles, rust preventives, antibacterial / antifungal agents, antifouling agents, high conductivity Child, and the like.

  Examples of the light diffusing fine particles include, but are not limited to, inorganic fine particles such as alumina, titanium oxide, calcium carbonate, barium sulfate, silicon dioxide, and glass beads, styrene-based crosslinked beads, MS ((meth) acrylic acid- Organic fine particles such as styrene) -based crosslinked beads and siloxane-based crosslinked beads. In addition, hollow cross-linked fine particles made of highly transparent resin materials such as acrylic resin, polycarbonate resin, MS resin, and cyclic olefin resin, and hollow fine particles made of glass are also included. In the inorganic fine particles, alumina and titanium oxide are more preferable. The light diffusing fine particles may be used alone or in combination, and is not limited at all.

  Here, the refractive index of the light diffusing fine particles is preferably 1.7 to 3.0, more preferably 1.7 to 2.5, and still more preferably 1.7 to 2.0. When the refractive index is 1.7 or more, sufficient scattering properties tend to be secured. Further, when the refractive index is 3.0 or less, the scattering in the vicinity of the lamp tends to be appropriately controlled, and as a result, the luminance unevenness and the unevenness of the emitted light color tone tend to be effectively prevented. is there.

  The refractive index is a value at a temperature of 20 ° C. based on the D line (589 nm). As a method for measuring the refractive index of the fine particles, for example, the fine particles are immersed in a liquid whose refractive index can be changed little by little, and the fine particle interface is observed while changing the refractive index of the liquid. The method of measuring the refractive index of the liquid at the time is mentioned. An Abbe refractometer or the like can be used to measure the refractive index of the liquid.

  The average particle diameter of the light diffusing fine particles is preferably 0.1 to 20 μm, more preferably 0.2 to 15 μm, still more preferably 0.3 to 10 μm, and still more preferably 0.4 to 5 μm. An average particle size of 20 μm or less is preferable because light loss due to back reflection or the like can be effectively suppressed and incident light can be efficiently diffused to the light emitting surface side. Further, it is preferable that the average particle diameter is 0.1 μm or more because emitted light can be effectively diffused and desired surface emission luminance and diffusibility can be obtained. The average particle diameter can be measured, for example, by a known laser diffraction method.

  Further, the content of the light diffusing fine particles in the methacrylic resin composition is 0.0001 to 0.03 mass with respect to 100 parts by mass of the methacrylic resin from the viewpoint of the expression of the light diffusing effect and the uniformity of surface emission. Parts, preferably 0.0001 to 0.01 parts by weight.

  Examples of the heat stabilizer include, but are not limited to, phosphorus antioxidants such as hindered phenol antioxidants and phosphorus processing stabilizers. Inhibitors are preferred.

  Examples of the hindered phenol antioxidant include, but are not limited to, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], thiodiethylene Bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-tert-butyl-a, a ′, a ″-(mesitylene-2,4,6-triyl) tri-p-cresol, 4,6-bis (Octylthiomethyl) -o-cresol, 4,6-bis (dodecylthiomethyl) -o-cresol, ethylenebis (oxyethylene) bis [3- 5-tert-butyl-4-hydroxy-m-tolyl) propionate], hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-tris ( 3,5-di-tert-butyl-4-hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 1,3,5-tris [(4- tert-butyl-3-hydroxy-2,6-xylin) methyl] -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 2,6-di-tert-butyl- 4- (4,6-bis (octylthio) -1,3,5-triazin-2-ylamine) phenol and the like can be mentioned. In particular, pentaerythritol terakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] is preferable.

  Moreover, you may use a commercially available phenolic antioxidant as said hindered phenolic antioxidant. Examples of such commercially available phenolic antioxidants include, but are not limited to, Irganox 1010 (Irganox 1010: pentaerythritol tetrakis [3- (3,5-di-t-butyl-4). -Hydroxyphenyl) propionate], manufactured by Ciba Specialty Chemicals), Irganox 1076: octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, Ciba Specialty Chemicals), Irganox 1330 (Irganox 1330: 3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-t-butyl-a, a ′, a ″-(mesitylene-2,4) , 6-Triyl) tri-p-cresol, Ciba Specialty Chemica Irganox 3114: 1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H , 3H, 5H) -trione, manufactured by Ciba Specialty Chemicals), Irganox 3125 (Irganox 3125, manufactured by Ciba Specialty Chemicals), Sumilizer BHT (Sumilizer BHT, manufactured by Sumitomo Chemical), Cyanox 1790 (Cyanox 1790, Cytec), Sumilizer GA-80 (Sumilizer GA-80, manufactured by Sumitomo Chemical), Sumilizer GS (Sumilizer GS, manufactured by Sumitomo Chemical), Vitamin E (manufactured by Eisai), etc. Among them, Irganox 1010, among others. Irganoc Scan 1076, it is preferable to use Sumilizer GS, and the like. Also they used a single kind alone, or in combination of two or more.

  Examples of the phosphorus antioxidant include, but are not limited to, tris (2,4-di-t-butylphenyl) phosphite and bis (2,4-bis (1,1). -Dimethylethyl) -6-methylphenyl) ethyl ester phosphorous acid, tetrakis (2,4-di-t-butylphenyl) (1,1-biphenyl) -4,4'-diylbisphosphonite, bis ( 2,4-di-t-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,4-dicumylphenyl) Pentaerythritol diphosphite, tetrakis (2,4-t-butylphenyl) (1,1-biphenyl) -4,4′-diylbisphosphonite, di-t-butyl Le -m- cresyl - phosphonite, and the like.

  Furthermore, a commercially available phosphorus antioxidant may be used as the phosphorus antioxidant. Examples of such commercially available phosphorus antioxidants include, but are not limited to, for example, Irgafos 168: Tris (2,4-di-t-butylphenyl) phosphite, Ciba Special Manufactured by T Chemicals, Irgafos 12 (Irgafos 12: Tris [2-[[2,4,8,10-tetra-t-butyldibenzo [d, f] [1,3,2] dioxaphosphine) 6-yl] oxy] ethyl] amine, manufactured by Ciba Specialty Chemicals), Irgafos 38: bis (2,4-bis (1,1-dimethylethyl) -6-methylphenyl) ethyl ester phosphorus Acid, manufactured by Ciba Specialty Chemicals), ADK STAB 329K (ADK STAB 329K, Asahi Den ADK STAB PEP36 (ADK STAB PEP36, manufactured by Asahi Denka), ADK STAB PEP-8 (ADK STAB PEP-8, manufactured by Asahi Denka), Sandstab P-EPQ (manufactured by Clariant), Weston 618 (manufactured by Weston 618, GE) , Weston 619G (Weston 619G, manufactured by GE), Ultranox 626 (Ultranox 626, manufactured by GE), Sumilyzer GP (Sumilizer GP, manufactured by Sumitomo Chemical), and the like. These may be used alone or in combination of two or more.

  The amount of the heat stabilizer described above is not particularly limited as long as the desired effect of the present embodiment is exhibited. From the viewpoint of effectively preventing problems such as bleeding out during processing, the methacrylic resin 100 It is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, still more preferably 1 part by mass or less, still more preferably 0.8 parts by mass or less, and still more preferably 0.01 parts by mass with respect to parts by mass. Part to 0.8 parts by mass.

  Examples of the ultraviolet absorber include, but are not limited to, for example, benzotriazole compounds, benzotriazine compounds, benzoate compounds, benzophenone compounds, oxybenzophenone compounds, phenol compounds, oxazole compounds, Examples include malonic acid ester compounds, cyanoacrylate compounds, lactone compounds, salicylic acid ester compounds, and benzoxazinone compounds. In particular, benzotriazole compounds and benzotriazine compounds are preferable. These may be used alone or in combination of two or more.

The ultraviolet absorber preferably has a vapor pressure (P) at 20 ° C. of 1.0 × 10 ⁻⁴ Pa or less from the viewpoint of sufficiently ensuring good moldability of the methacrylic resin composition. It is more preferably 0.0 × 10 ⁻⁶ Pa or less, and further preferably 1.0 × 10 ⁻⁸ Pa or less.

  Here, the favorable moldability of the methacrylic resin composition means, for example, that the low-molecular compound adheres less to the roll when it is molded as a film. By reducing the adhesion of low molecular weight compounds to the roll, there is a tendency to effectively prevent the low molecular weight compounds from being deposited on the roll surface, so it is possible to effectively prevent deterioration of appearance and optical properties. There is a tendency.

  The melting point (Tm) of the ultraviolet absorber is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, further preferably 130 ° C. or higher, and even more preferably 160 ° C. or higher. preferable.

  The ultraviolet absorber preferably has a weight reduction rate of 50% or less, more preferably 30% or less, and more preferably 15% or less when the temperature is increased from 23 ° C. to 260 ° C. at a rate of 20 ° C./min. More preferably, it is more preferably 10% or less, still more preferably 5% or less. The weight reduction rate can be measured by an existing thermogravimetric measuring device (TGA).

  The blending amount of the ultraviolet absorber is not particularly limited as long as the desired effect of the present embodiment is exhibited, but from the viewpoint of effectively preventing problems such as bleeding out during processing, 100 mass of methacrylic resin The amount is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, still more preferably 1 part by mass or less, still more preferably 0.8 parts by mass or less, and still more preferably 0.01 parts by mass. The amount is 0.8 parts by mass or less.

[Processing of methacrylic resin and methacrylic resin composition]
A method for processing a methacrylic resin, or a method for processing a methacrylic resin composition by mixing the methacrylic resin with various additives and other resins is not particularly limited. Examples of the method include kneading using a kneader such as a roll, a kneader, a roller mixer, and a Banbury mixer. Among these, kneading with an extruder is preferable in terms of productivity. The kneading temperature may be in accordance with the preferred processing temperature of the polymer constituting the methacrylic resin and other resins to be mixed, and is generally in the range of 140 to 300 ° C, preferably in the range of 180 to 280 ° C.

(4) Method for Producing Methacrylic Resin Sheet or Resin Base for Ball Game Machine The method for producing a methacrylic resin sheet used in the present embodiment is to add (B) to (A) at a predetermined ratio. As long as it is, it is not particularly limited. That is, various known methods can be applied. Examples thereof include a melt extrusion molding method and an injection molding method. When the acrylic rubber particles are contained in the methacrylic resin sheet, an extrusion method is preferable from the viewpoint of achieving uniform dispersion of the multilayer structure particles. As described above, the method for manufacturing a resin base for a ball game machine according to the present embodiment includes a methacrylic resin (A) containing first multilayer structure particles made of acrylic rubber and a second made of acrylic rubber. It is the manufacturing method of the resin base for ball game machines provided with the methacrylic resin sheet containing the methacrylic resin (B) different from the said (A) containing the multilayer structure particle of this. Furthermore, in the method for manufacturing a resin base for a ball game machine according to the present embodiment, the (B) is added in an amount of 5 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the (A). A step of preparing a resin sheet, wherein the methacrylic resin sheet contains 15% by mass or more and 50% by mass or less of an acetone insoluble part. According to the above manufacturing method, not only can the resources be effectively utilized by using the rework product, but also the quality of the resin base for a ball game machine obtained can be improved. In other words, the resin base for the ball game machine obtained by the above-described method for manufacturing the resin base for the ball game machine not only realizes effective use of resources, but also provides optical characteristics, mechanical characteristics, cutting workability, and a game board. It can be excellent in the balance of the production effect. In addition, as addition amount of (B) with respect to 100 mass parts of said (A), it is preferable that they are 5.3 mass parts or more and 100 mass parts or less, More preferably, they are 11.1 mass parts or more and 66.7 mass parts or less. It is.

  As a suitable temperature range at the time of sheet extrusion, it is 240 degreeC or more and 275 degrees C or less, More preferably, it is 245 degreeC or more and 270 degrees C or less, More preferably, it is 250 degreeC or more and 260 degrees C or less. When the resin temperature falls below 240 ° C., the resin viscosity increases and the resin pool formed when the molten resin that has exited the T-die is sandwiched between a pair of cooling rolls, so-called bank shape becomes unstable and productivity is increased. Or a deteriorated resin existing in a fine retaining portion inside the flange portion or the T die is scraped out, and a defect such as a foreign matter defect is likely to occur. On the other hand, when the resin temperature exceeds 275 ° C., decomposition of the resin occurs, and silver streak occurs on the sheet surface. Further, the resin is foamed by the cracked gas to cause a vent-up, and the productivity is lowered.

  The methacrylic resin sheet in this embodiment is also excellent in impact resistance. Therefore, for example, when a nail hole is machined on the surface of the methacrylic resin sheet in this embodiment using an NC processing machine such as a multi-axis drilling machine, a pachinko nail (especially a brass pachinko nail) can be driven stably. it can. From the viewpoint of realizing more stable nailing, the thickness of the methacrylic resin sheet in this embodiment is preferably 5 mm or more and 15 mm or less, but is not limited to such a range, and good pachinko nailing is achieved. Is possible. As described above, the methacrylic resin sheet in this embodiment has a nailing workability higher than that of a veneer plywood and a holding power of the nail.

  The material of the pachinko nails includes brass, iron, stainless steel, etc., but brass is preferred. There are two types of brass nails, one with no screw and one with a screw. The nail holding force after nailing the sheet surface, the clearance between the nail hole diameter and the nail diameter, and the periphery of the nail The two types of brass nails can be properly used in consideration of the presence or absence of microcracks occurring in the case.

  The sheet thickness of the methacrylic resin sheet in this embodiment is preferably in the range of 5 mm to 19 mm, and more preferably 8 mm to 12 mm. When the sheet thickness is 5 mm or more, the holding force at the time of nail removal tends to be improved on the sheet surface. When the sheet thickness is 19 mm or less, the total light transmittance better as a ball game machine resin base and The yellowness can be maintained, and the production effect tends to be improved, for example, the liquid crystal display looks clearer. Here, from the viewpoint of ensuring a sufficiently good appearance, the yellowness (YI) at a sheet thickness of 10 mm of the methacrylic resin sheet in the present embodiment is preferably 4 or less and -3 or more. From the same viewpoint, the YI is more preferably 3.8 or less and −2 or more, and further preferably 3.5 or less and −1 or more.

  The tensile modulus of elasticity of the methacrylic resin sheet in the present embodiment is preferably 1200 MPa to 2500 MPa, more preferably 1500 MPa to 2400 MPa. When the tensile modulus is 2500 MPa or less, whitening and cracks that can occur after nailing to the sheet surface tend to be more effectively prevented. When the tensile modulus is 1200 MPa or more, the rigidity and hardness (hardness) of the sheet is high. There is a tendency to further improve and more effectively prevent the adhesion of scratches to the sheet surface.

(5) Crushed rework product When subjected to extrusion molding or the like, the amount of the rework product to be blended with the virgin material of the methacrylic resin sheet in this embodiment depends on the optical properties (total light transmittance and yellowness) of the sheet, appearance ( This affects the number of rubber aggregates, etc., and the tensile modulus.

  Resin molding materials used for various molding processes such as extrusion molding and injection molding are usually manufactured by various polymerization methods such as suspension polymerization and solution polymerization, and are mainly molded in the form of beads or pellets. Provided for processing. The beads produced by suspension polymerization or the like may be further melt-kneaded by an extruder and processed into pellets, and then used for various processing steps such as extrusion molding and injection molding.

  “Virgin material” in the present specification is a molding material prepared for the purpose of being used for the above-mentioned various molding processes, and has never been used for molding processes such as extrusion molding and injection molding. It means a methacrylic resin material containing particles.

  Furthermore, the “rework product” is a resin material that has been subjected to a molding process once or more as a resin sheet, a resin film, or an injection molded product of any shape, and is used for the virgin material. It means a pulverized product obtained by pulverizing a sheet of methacrylic resin (B) different from the sheet of methacrylic resin (A). In addition, in order to achieve the purpose of improving the production stability at the time of extrusion molding and blending various additives, etc., this pulverized product is melt-kneaded by an extruder as necessary, and a resin material processed into a pellet form is also used. Included in “rework product” in the specification. It is sufficient that the methacrylic resin (A) and the methacrylic resin (B) can be distinguished as described above, and the resin materials used as the raw materials may be the same or different. That is, the first multilayer structure particle contained in the methacrylic resin (A) and the second multilayer structure particle contained in the methacrylic resin (B) may be the same or different.

  In addition to the above pulverized acrylic resin containing rubber particles, acrylic resin sheets or injection molded pulverized products not containing rubber particles, as well as AS and other types of resins different from virgin materials A pulverized product of a molded product formed of a material can also be used. In that case, it is preferable to adjust the addition amount of each pulverized product so as not to impair physical properties such as optical properties, surface hardness, appearance, and heat resistance necessary for the methacrylic resin sheet in the present embodiment.

  The molded product to be pulverized to obtain the “rework product” in the present embodiment is not particularly limited. For example, in the sheet extrusion molding process, the end material generated by the trimming process at both ends in the sheet width direction and the production conditions In addition to non-standard products (for example, sheets whose plate thickness deviates from the standard, etc.) generated during the adjustment of the board, end materials generated when cutting the inner and outer periphery of the game board can be used. Furthermore, an injection molded product formed of rubber particle-containing acrylic resin can be used as well. The degree of pulverization is not particularly limited as long as it can be stably melt-kneaded in an extruder. For example, it can be a flaky amorphous material having a maximum length of about 1 to 15 mm. . In addition, it does not specifically limit as said grinding | pulverization method in this embodiment, A various well-known grinding | pulverization method is employable.

  In this embodiment, the total light transmittance and tensile elastic modulus of the methacrylic resin sheet tend to decrease as the blending amount of the pulverized rework product increases. Furthermore, since the yellowness (yellowness) tends to increase as the blending amount increases, the appearance tends to be inferior. From the viewpoint of a balance between ensuring good yellowness (YI) and realizing effective use of resources, the amount of the reworked product is 5% by mass or more and 60% by mass or less. From the same viewpoint, the amount of the reworked product is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less. When the amount of the reworked product exceeds 60% by mass, the cut surface of the sheet is yellowish and the appearance is inferior. As a result, the merchandise value as a game board is significantly reduced. For example, when it exceeds 70 mass%, it will deteriorate so that the yellowness degree (YI) in sheet thickness 10mm exceeds 7.

  As described above, according to the ball game machine base of the present embodiment, for example, a thickness adjustment (switching) plate generated at the time of sheet manufacture, a trimmed edge of the sheet, a defective sheet, or a ball game machine base manufacture Collecting the hollow material (center of the sheet) and milled material that are sometimes generated, finely pulverized into an extrudable shape (size), and returning it to the extruder during sheet production (rework) to improve quality It can be said that it is a technology that contributes not only to the effective use of resources but also to the quality improvement of the base of the ball game machine.

  EXAMPLES Next, although an Example and a comparative example demonstrate this invention in detail, this invention is not limited at all by these examples.

  About the following Examples 1-15 and Comparative Examples 1-8, the following characteristic test was implemented. That is, for the sheets obtained in each Example and each Comparative Example (excluding Comparative Example 8), acetone insoluble portions and plasticization stability (presence of vent-up) were measured and evaluated. Furthermore, the optical characteristics of the sheets of each Example and each Comparative Example [total light transmittance, yellowness (YI)], appearance (occurrence / absence) (silver, foreign matter, number of aggregates of poor dispersion of acrylic rubber), Tensile modulus, Charpy impact strength (no notch), pencil hardness (sheet surface hardness), after nailing (presence of whitening, occurrence of cracks), machinability in NC cutting A comparative evaluation of pass / fail was performed.

(1) Compounding of pulverized rework product Faulty sheets that occurred when a resin sheet was produced in the same manner as described in Example 2 (described later) (end material generated during plate thickness adjustment, switched product generated during switching, sheet extrusion direction) In the middle of the sheet in order to produce a partial liquid crystal generated when a ball game machine base is produced in the same manner as described in Example 2 to be described later) Sheets (end materials) having the same blending amount with respect to the acetone-insoluble portion such as the cutting material were collected at the same location. Next, after confirming that there was no forgetting to peel off the surface protective film, it was cut into a certain amount (700 mm or less) using a panel saw (cutting machine). In cutting, other resin, dust, foreign matter, surface protective film and the like were pulverized with great care so as not to enter the pulverizer. After that, the above-mentioned sheets are put into a large pulverizer one by one for each leaf and finely pulverized, and the temperature is controlled so that the temperature of the pulverized product in the apparatus rises and the finely pulverized products do not fuse. )Did. A finely pulverized product of a certain size (long side: about 15 mm or less) that has passed through the mesh in the pulverizer is sucked into the hopper, stored, and used as a raw material for rework. The finely pulverized product is then put into the hopper without being washed with water. It was decided to.

(2) Content of acetone insoluble part After drying the resin sheet from which the surface protective film had been peeled off overnight (about 80 ° C., about 12 hours or more), a part of the resin sheet was cut out and weighed about 1.0 g. (W1). Then, after putting a sample in a centrifuge tube (metal tube), 20 mL of acetone was added, and the mixture was allowed to stand at room temperature for about 1 day, and then shaken with a shaker for 2 hours. Next, using a vacuum type high-speed cooling centrifuge (model “CR26H”) manufactured by Hitachi Koki Co., Ltd., conditions were set at 5 ° C. and 24000 rpm, followed by centrifugation for 1 hour.

  After shaking, the supernatant was removed by decantation, 20 mL of acetone was newly added, and the mixture was shaken at room temperature for 1 hour. After the shaking, the mixture was centrifuged at 5 ° C. and 24000 rpm for 1 hour. Again, the same method and conditions were repeated a total of 3 times. The supernatant was decanted off and allowed to air dry overnight.

The vacuum dryer was set at 100 ° C., taken out after vacuum drying for a whole day and night (about 12 hours or more), cooled to room temperature in a desiccator, and the mass of the residue was weighed (W2). The content (mass%) of the acetone insoluble part was calculated by the following formula (X).
Acetone insoluble part (X) = (W2 / W1) × 100

(3) Plasticization stability (with or without vent-up)
Melted from a vent part installed in the middle of an extruder with a bend (104φ twin screw extruder, L / D (extruder cylinder length / extruder cylinder diameter) = 34) and degassed in vacuum The case where there is no resin vent-up (blow-out) and extrusion is good is marked with “○”, the case where a slight vent-up is observed is marked with “△”, and the case where the vent is clearly lifted and the extrusion is unstable is marked with “X”. A relative comparison of the extrusion stability was made visually.

(4) Optical properties [total light transmittance, yellowness (YI)]
(A) Total light transmittance The total light transmittance was measured according to the prescription | regulation method of JISK7105 "the optical characteristic test method of a plastic". That is, the resin sheet from which the surface protective film was peeled was cut into three pieces of a 50 × 50 mm sample size, measured using a turbidimeter model “1001DP” manufactured by Nippon Denshoku Industries Co., Ltd., and the average value was obtained. It was. This average value was adopted as the total light transmittance of each example.

(B) Yellowness (YI)
Yellowness (YI) was measured according to a method defined in JIS K 8722 “Color Measurement Method—Reflection and Transmission Object Color”. That is, the resin sheet from which the surface protective film was peeled off was cut out into three pieces with a sample size of 50 × 50 mm, and a color difference meter model “TC-8600A” manufactured by Tokyo Denshoku was used, and the measurement conditions were set as the C light source, The measurement was carried out after setting the visual field at 10 degrees, and the average value was obtained. This average value was adopted as the yellowness (YI) of each example.

(5) Sheet surface condition (number of aggregates, silver, foreign matter)
(A) Number of agglomerates A sheet extruded to a width of 1000 mm (length L: cut to 300 mm) using an extruder is cut into about three equal parts, and then cut to a size of 332 × 300 mm, followed by surface protection on both sides of the sheet. The film was peeled off and the appearance was observed in detail. “○” indicates that no aggregate is generated due to poor dispersion of the acrylic rubber particles, and “△” indicates that several aggregates (2 to 5) of the aggregate (poor dispersion) are observed. A relative comparison was made by visual observation where a large number of rubber agglomerates were observed and a defective appearance was indicated as “x”.

(B) Silver (silver streak)
(A) Relative comparison of the presence or absence of silver generation was performed on the samples used in the relative comparison of the number of aggregates. Silver is also known as silver, and is a white streak-like pattern similar to silver that occurs along the flow of the sheet on the exterior of the sheet surface. When the surface appearance of the sheet is good without any abnormal appearance, “○” is indicated, “△” is indicated when silver is slightly observed, and “X” is indicated when it is clearly recognized. It was.

(C) Foreign matter (a) The samples used in the relative evaluation of the number of aggregates were subjected to a relative comparison of the occurrence of foreign matter with minute irregularities that can be visually observed on the sheet surface appearance. When no foreign matter is recognized, “◎”, when several (1-5) pieces are recognized, “◯” is designated, and when (6-10) foreign matters are found, “△”, 11 pieces or more. Relative comparison was made by visual observation with “×” being recognized.

(6) Tensile modulus The tensile modulus was measured according to the method defined in JIS K 7162-1994 “Plastics—Testing Method for Tensile Properties Part 2: Molding, Extrusion and Casting Test Conditions”. That is, the resin sheet from which the surface protective film was peeled off was cut into test piece type 1B (length: L = 150 mm or more, thickness: t = 10 mm, width of parallel part: 80 ± 2 mm), and then the thickness and parallel part were prepared. Were measured accurately, and after the measurement, the sample was pulled with a tensile tester at a test speed of 1 mm / min, the tensile modulus was measured, and the average value was obtained by measuring five times in the same manner. This average value was adopted as the tensile elastic modulus of each example.

(7) Charpy impact strength (no notch)
The Charpy impact strength (no notch) was measured according to the method defined in JIS K 7111 “Method for Charpy Impact Test of Hard Plastic”. That is, after preparing a No. 1 test piece (length: L = 80 ± 2 mm, thickness: t = 10 mm, not cut out), the surface protective film was peeled off, and the dimensions were measured and recorded. Next, the sample was fixed to a Charpy impact tester for hard plastic, and a hammer (capacity: 15 J) was lifted and dropped. Repeated five times in the same manner, the absorbed energy was calculated and the Charpy impact strength value was determined.

(8) Pencil hardness In accordance with the JIS K 5600-5-4 “General paint test method, Part 5: Mechanical properties of coating film, Section 4: Scratch hardness (pencil method)”, a surface protective film is applied. The peeled resin sheet was cut into a size of 100 mm × 150 mm and used as a sample. Subsequently, after being left in a dryer at about 80 ° C. for 12 hours or more, it was naturally cooled in a desiccator. Using a pencil scratch hardness tester manufactured by Toyo Seiki Seisakusho Co., Ltd., the scratch angle was 45 degrees and the load (weight) was 750 g.

(9) Appearance evaluation after nailing (whether whitening occurs, cracks occur)
A resin sheet (size 50 mm × 150 mm) of each example was prepared, and 10 or more holes were penetrated with a drilling machine using a straight shank drill (φ1.73 mm). Then, a brass pachinko nail (with a screw) having a brass nail φ1.84 mm overall length of 27.7 mm, a length of 26.5 mm after pulling the head portion, and a taper portion of 3 mm was set in the center of the hole. Subsequently, the head of the nail was struck several times with an iron hammer to intrude about 10 mm. The presence or absence of whitening and cracking around the hit nail was visually evaluated.

(10) Cutting workability After setting the NC processing machine to general woodworking (veneer plywood) cutting conditions (rotation speed: 3000 rpm), both surfaces of the resin sheet are surface protective films [manufactured by Sanei Kaken Co., Ltd .: product name : JT28, pressure-sensitive adhesive: acrylic pressure-sensitive adhesive, total thickness of base material and pressure-sensitive adhesive layer of film: 88 μm], with each leaf in a circular shape with a diameter of 60 mm and a positive length of 60 mm on one side NC cutting was performed on the center portion of the sheet in a triangular shape and three square shapes each having a side of 60 mm. The case where there was no problem and good processing was indicated as “○”, and the case where slight peeling of burrs or film was observed was indicated as “△”, and the peeling of burrs or film was clearly recognized. Relative comparison with the case “x” was made visually.

  Next, while showing the manufacture example of an acrylic rubber particle, each Example and each comparative example are demonstrated.

<Production example>
Ion-exchanged water 6860 mL and sodium dihexyl sulfosuccinate 13.7 g were charged into a reactor with a reflux condenser with an internal volume of 10 L, and the temperature was raised to 75 ° C. in a nitrogen atmosphere while stirring at a rotational speed of 250 rpm. There was virtually no state.

  907 g of methyl methacrylate (hereinafter also referred to as “MMA”), 33 g of n-butyl acrylate (hereinafter also referred to as “BA”), 2- (2′-hydroxy-5′-methylphenyl) benzotriazole ( Hereinafter, 0.28 g of “HMBT”) and 0.93 g of allyl methacrylate (hereinafter also referred to as “ALMA”) were mixed to obtain a mixture (I-1).

  222 g of the mixture (I-1) was added all at once to the reactor equipped with a reflux condenser, and 0.22 g of ammonium persulfate was added 5 minutes after the addition. After 40 minutes, the remaining 719 g of the mixture (I-1) was continuously added over 20 minutes and held for 60 minutes after the addition was completed. Subsequently, after adding 1.01 g of ammonium persulfate, a mixture (I-2) comprising 1067 g of BA, 219 g of styrene (hereinafter also referred to as “St”), 0.39 g of HMBT, and 27.3 g of ALMA was continuously added over 140 minutes. And added for 180 minutes after the addition.

  Next, after adding 0.30 g of ammonium persulfate, MMA 730 g, BA 26.5 g, HMBT 0.22 g, n-octyl mercaptan (hereinafter also referred to as “n-OM”) 0.76 g of a mixture (I-3) ) Was continuously added over 40 minutes. After completion of the addition, the temperature was raised to 95 ° C. and held for 30 minutes to obtain a latex. The obtained latex was put into a 3% by mass sodium sulfate warm aqueous solution, and salted and coagulated. Then, after repeating dehydration and washing, drying was performed to obtain a multilayer structure acrylic polymer (I).

A part of the resulting multilayer structure acrylic polymer (I) was extracted and kneaded with a methacrylic resin (manufactured by Asahi Kasei Chemicals Corporation, trade name “Del powder: 70H beads”) to obtain a rubber particle sample. A part of the obtained sample was cut out and photographed with a RuO ₄ (ruthenic acid) -stained ultrathin section method using an electron microscope (× 100,000 times) of a section of the stained rubber particles. The diameter of about 20 photographed rubber particles was obtained on a scale, and the average was taken as the average particle diameter. The average particle diameter of the finally obtained rubber particles was 0.23 μm.

  For comparison, a multilayer structure particle of flaky acrylic rubber (manufactured by Mitsubishi Rayon Co., Ltd., trade name “IR441”) is used as an acrylic rubber particle, and a part of the sheet obtained with a sheet extruder is subjected to an electron microscope. The photograph was taken at the same magnification. The diameter of about 20 rubber particles photographed was obtained on a scale, and the average particle diameter of the rubber particles was about 0.23 μm. That is, the rubber particles obtained by IR441 had an average particle diameter almost the same as that of the rubber particles obtained by the multilayer acrylic polymer (I) described above.

[Example 1]
50% by mass of methacrylic resin (manufactured by Asahi Kasei Chemicals Co., Ltd., trade name “Del powder: 70H beads”) and 50% by mass of acrylic rubber particles (rubber concentration: 100% by mass) of the above production example were tumbler (mixer, 30 Rotation / minute × 30 minutes) After uniform dispersion, a φ48 mm twin screw extruder was used to prepare pellets (MP) with 50% by mass of rubber blended by pelletizing (granulating machine).

  Subsequently, 35% by mass of the above-mentioned methacrylic resin (manufactured by Asahi Kasei Chemicals Co., Ltd., trade name “Del powder: 70H beads”), 35% by mass of master pellets containing 50% by mass of rubber, and a sheet in Example 2 described later Finely pulverized (long side: approx. 15 mm or less) product and NC of defective sheets generated during production (end material generated during sheet thickness adjustment, change product generated during switching, end material after trimming at both ends in sheet extrusion direction) 30% by mass of rework product (rubber compounding amount 25% by mass) consisting of finely pulverized hollow material (center of sheet) generated when manufacturing a ball game machine base with a processing machine is put in each stock tank. After that, a predetermined amount was measured with an automatic weighing device. The mixture was put into a mixer tank from three stock tanks and mixed for several minutes so as to achieve uniform mixing. A resin mixture was obtained and transferred to a blend tank, and then a predetermined amount was charged into an extruder. The obtained resin mixture was supplied to a sheet extruder having a φ104 mm twin screw extruder, L / D (extruder cylinder length / extruder cylinder diameter) = 34, and adjusted to a thickness of 10 mm and a width of 1000 mm. The temperature was set to about 260 ° C., the die inlet temperature was set to about 250 ° C., and the sheet was extruded so that the resin temperature was 250 ° C.

The polishing roll temperature for polishing the surface of the sheet coming out of the die was about 80 ° C. On both surfaces of the obtained extruded sheet, a surface protective film (manufactured by Sanei Kaken Co., Ltd., trade name “JT28”, thickness (total thickness of base material layer and adhesive layer): 89 μm, base material layer: polyethylene, adhesive layer: An acrylic pressure-sensitive adhesive (acrylic ester copolymer)) was attached in the in-line process (pressure at the time of application: 2 kg / cm ² , tension: about 6 kg). Thereafter, the sheet was cut to a certain size within the process. The obtained composite sheet was cut out with a circular saw to obtain a sample for evaluation, and each of the above evaluation items was evaluated.

[Example 2]
Except having raised the resin temperature in the extruder of a sheet extruder from 250 degreeC to 260 degreeC, it extruded by the same raw material composition content as Example 1, the sample for evaluation was obtained, and each evaluation item was evaluated. In addition, defective sheets that occurred when the sheet of Example 2 was manufactured (end materials generated during sheet thickness adjustment, switching products generated during switching, end materials after trimming at both ends in the sheet extrusion direction, etc.), ball game Collecting sheets (end materials) with the same blending amount for acetone insoluble parts such as hollow materials generated by hollowing out the central part of the sheet to produce a partial liquid crystal during production of the machine base in the same place And pulverized. The rework product thus obtained was subjected to the preparation of Example 1 described above.

[Example 3]
A methacrylic resin (made by Asahi Kasei Chemicals Co., Ltd., trade name “Del powder: 70H beads”) 75% by mass, blended so as to be 25% by mass of the acrylic rubber particles of the above production example, and then tumbler (mixer) Uniformly dispersed and pelletized with a φ48 mm twin screw extruder (granulator) to give an equal-magnification product with a rubber compounding amount of 25% by mass. 70% by mass of the same-size product and 30% by mass of the finely pulverized rework product (rubber compounding amount 25% by mass) were mixed by the method described in Example 1 so as to achieve uniform dispersion to obtain a resin mixture. It was. The obtained resin mixture was set to the extrusion conditions of Example 2, samples for evaluation were obtained, and each evaluation item was evaluated.

[Example 4]
42% by mass of a methacrylic resin (Asahi Kasei Chemicals Co., Ltd., trade name “Del powder: 70H beads”), 28% by mass of a master pellet (MP) containing 50% by mass of rubber used in Example 1, (Rubber compounding amount 20% by mass) 30% by mass was blended and mixed by the method of Example 1 so as to be uniformly dispersed to obtain a resin mixture. The obtained resin mixture was set to the extrusion conditions of Example 2, samples for evaluation were obtained, and each evaluation item was evaluated.

[Example 5]
28% by mass of a methacrylic resin (manufactured by Asahi Kasei Chemicals Co., Ltd., trade name “Del powder: 70H beads”), 42% by mass of master pellets (MP) containing 50% by mass of rubber used in Example 1, 30 mass% of rubber compounding amount) was blended and mixed so as to be uniformly dispersed by the method of Example 1 to obtain a resin mixture. The obtained resin mixture was extruded at a resin temperature of 250 ° C. under the extrusion conditions in Example 1 to obtain a sample for evaluation, and each evaluation item was evaluated.

[Example 6]
Except that the resin temperature in the extruder of the sheet extruder was raised from 250 ° C. to 260 ° C., extrusion was carried out with the same raw material composition as in Example 5, samples for evaluation were obtained, and each evaluation item was evaluated.

[Example 7]
18% by mass of methacrylic resin (manufactured by Asahi Kasei Chemicals Co., Ltd., trade name “Del powder: 70H beads”), 52% by mass of master pellet (MP) with 50% by mass of acrylic rubber used in Example 1, rework The product (rubber compounding amount: 37% by mass) was mixed with 30% by mass and mixed by the method of Example 1 so as to be uniformly dispersed to obtain a resin mixture. The obtained resin mixture was extruded at a resin temperature of 260 ° C. under the extrusion conditions of Example 2 to obtain a sample for evaluation, and each evaluation item was evaluated.
[Example 8]
47.5% by mass of methacrylic resin (product name “Del powder: 70H beads” manufactured by Asahi Kasei Chemicals Co., Ltd.), 47.5% by mass of master pellet (MP) with 50% by mass of rubber used in Example 1 Then, 5% by mass of a rework product (rubber compounding amount: 25% by mass) was blended and mixed by the method of Example 1 so as to be uniformly dispersed to obtain a resin mixture. The obtained resin mixture was set to the extrusion conditions (resin temperature: 250 ° C.) of Example 1, samples for evaluation were obtained, and each evaluation item was evaluated.

[Example 9]
Except having raised the resin temperature in the extruder of a sheet extruder from 250 degreeC to 260 degreeC, it extruded by the same raw material composition content as Example 8, the sample for evaluation was obtained, and each evaluation item was evaluated.

[Example 10]
45% by mass of methacrylic resin (Asahi Kasei Chemicals Co., Ltd., trade name “Del powder: 70H beads”), 45% by mass of master pellet (MP) with 50% by mass of rubber used in Example 1, rework product ( Rubber blending amount 25 mass%) 10 mass% was blended and mixed by the method of Example 1 so as to be uniformly dispersed to obtain a resin mixture. The obtained resin mixture was set to the extrusion conditions (resin temperature: 260 ° C.) of Example 2, an evaluation sample was obtained, and each evaluation item was evaluated.

[Example 11]
40% by mass of a methacrylic resin (Asahi Kasei Chemicals Co., Ltd., trade name “Del powder: 70H beads”), 40% by mass of a master pellet (MP) containing 50% by mass of rubber used in Example 1, (Rubber blending amount 25% by mass) 20% by mass was blended and mixed by the method of Example 1 so as to be uniformly dispersed to obtain a resin mixture. The obtained resin mixture was set to the extrusion conditions (resin temperature: 260 ° C.) of Example 2, an evaluation sample was obtained, and each evaluation item was evaluated.

[Example 12]
30% by mass of methacrylic resin (Asahi Kasei Chemicals Co., Ltd., trade name “Del powder: 70H beads”), 30% by mass of master pellets (MP) with 50% by mass of rubber used in Example 1, rework product ( 40% by mass of rubber (25% by mass of rubber) was compounded and mixed by the method of Example 1 so as to achieve uniform dispersion to obtain a resin mixture. The obtained resin mixture was set to the extrusion conditions (resin temperature: 260 ° C.) of Example 2, an evaluation sample was obtained, and each evaluation item was evaluated.

[Example 13]
25% by mass of methacrylic resin (trade name “Del powder: 70H beads” manufactured by Asahi Kasei Chemicals Co., Ltd.), 25% by mass of master pellets (MP) with 50% by mass of rubber used in Example 1, rework product ( 50 mass%) (rubber compounding amount 25 mass%) was compounded and mixed by the method of Example 1 so as to be uniformly dispersed to obtain a resin mixture. The obtained resin mixture was set to the extrusion conditions (resin temperature: 250 ° C.) of Example 1, samples for evaluation were obtained, and each evaluation item was evaluated.

[Example 14]
Except that the resin temperature in the extruder (near the die entrance) of the sheet extruder was increased from 250 ° C. to 260 ° C., extrusion was performed with the same raw material composition as in Example 13, and a sample for evaluation was obtained. evaluated.

[Example 15]
Methacrylic resin (Asahi Kasei Chemicals Co., Ltd., trade name “Del powder: 70H beads”) 50%, acrylic rubber particles, flake acrylic rubber multilayer structure particles (Made by Mitsubishi Rayon Co., Ltd., trade name “IR441”) After uniformly dispersing 50% with a tumbler (mixer), a pellet pellet (MP) containing 50% by mass of rubber was prepared by pelletizing using a 30 mmφ twin-screw extruder (manufactured by Nakatani Machinery Co., Ltd.). did. Subsequently, 35% by mass of a commercially available methacrylic resin (manufactured by Asahi Kasei Chemicals Co., Ltd., trade name “Del Powder: 70H beads”), 35% by mass of master pellets containing 50% by mass of rubber, manufactured by Mitsubishi Rayon Co., Ltd. A rework product of 30% by mass of a sheet with the name “IR441” was blended and mixed by the method of Example 1 so as to be uniformly dispersed to obtain a resin mixture. The obtained resin mixture was set to the extrusion conditions (resin temperature: 260 ° C.) of Example 2, an evaluation sample was obtained, and each evaluation item was evaluated.

[Comparative Example 1]
75% by mass of methacrylic resin (manufactured by Asahi Kasei Chemicals Co., Ltd., trade name “Del powder: 70H beads”) and 25% by mass of acrylic rubber particle powder (rubber concentration: 100% by mass) of the above production example are tumbler (mixed) Machine) to obtain a resin mixture without pelletizing (granulating). The obtained resin mixture was set to the extrusion conditions (resin temperature: 260 ° C.) of Example 2, an evaluation sample was obtained, and each evaluation item was evaluated.

[Comparative Example 2]
70% by mass of methacrylic resin (made by Asahi Kasei Chemicals Corporation, trade name “Del powder: 70H beads”), methacrylic resin not blended with rubber (made by Asahi Kasei Chemicals Co., Ltd., trade name “Delaglass A999: transparent, plate thickness: 10 mm) Was mixed with 30% by mass of a rework product finely pulverized with a large pulverizer and mixed so as to be uniformly dispersed by the method of Example 1. The obtained resin mixture was obtained in Example. No. 2 extrusion conditions (resin temperature: 260 ° C.) were obtained, evaluation samples were obtained, and each evaluation item was evaluated.

[Comparative Example 3]
56% by mass of methacrylic resin (manufactured by Asahi Kasei Chemicals Co., Ltd., trade name “Del powder: 70H beads”), 14% by mass of master pellets (MP) with 50% by mass of rubber used in Example 1, rework product ( 30% by mass of rubber (10% by mass of rubber) was compounded and mixed by the method of Example 1 so as to be uniformly dispersed to obtain a resin mixture. The obtained resin mixture was set to the extrusion conditions of Example 1 (resin temperature: 250 ° C.), an evaluation sample was obtained, and each evaluation item was evaluated.

[Comparative Example 4]
Except having raised the resin temperature in the extruder of a sheet extruder from 250 degreeC to 260 degreeC, it extruded by the same raw material composition content as the comparative example 3, the sample for evaluation was obtained, and each evaluation item was evaluated.

[Comparative Example 5]
50% by mass of methacrylic resin (made by Asahi Kasei Chemicals Co., Ltd., trade name “Del powder: 70H beads”), 50% by mass of master pellets (MP) of 50% by mass of rubber used in Example 1, That is, a resin mixture was obtained by mixing so as to be uniformly dispersed without blending a rework product. The obtained resin mixture was set to the extrusion conditions of Example 2 (resin temperature: 260 ° C.), an evaluation sample was obtained, and each evaluation item was evaluated.

[Comparative Example 6]
15% by mass of a methacrylic resin (Asahi Kasei Chemicals Co., Ltd., trade name “Del powder: 70H beads”), 15% by mass of a master pellet (MP) containing 50% by mass of rubber used in Example 1, 70% by mass of rubber (25% by mass of rubber) was mixed and mixed by the method of Example 1 so as to be uniformly dispersed to obtain a resin mixture. The obtained resin mixture was set to the extrusion conditions of Example 2 (resin temperature: 260 ° C.), an evaluation sample was obtained, and each evaluation item was evaluated.

[Comparative Example 7]
The raw material of virgin was not used at all, and 100% by mass of the reworked product (rubber blending amount 25% by mass), that is, only the finely pulverized reworked product was put into the hopper to obtain a resin mixture. The obtained resin mixture was set to the extrusion conditions of Example 2 (resin temperature: 260 ° C.), an evaluation sample was obtained, and each evaluation item was evaluated.

[Comparative Example 8]
A commercially available transparent polycarbonate resin sheet (manufactured by Asahi Glass Co., Ltd., trade name “Lexane” (plate thickness 10 mm, grade 9034 transparent) was used as the transparent resin sheet, and each evaluation item was evaluated. The sample did not break, and the numerical value was 149 KJ / m ² (indicated as “NB” in Table 1 below).

  The result of each Example and each comparative example is shown to Tables 1-2.

  As can be seen from Table 2, none of the bullet ball game machine resin bases of the comparative examples achieved the desired result of this embodiment in at least one performance evaluation. On the other hand, as shown in Table 1, the ball game machine resin base of each example showed the desired result of this embodiment in all evaluations. That is, by using a bullet ball game machine resin base equipped with the desired methacrylic resin sheet of this embodiment, whitening and cracks do not occur when nailing, the nail holding power is excellent, It was confirmed that the surface film was not peeled off or floated during machine cutting, and that the machinability was excellent and the effect as a game board was excellent.

  The ball game machine base sheet of the present invention can be effectively used by returning (reworking) the defective sheet and the hollow material generated at the time of producing the resin base of the ball ball machine to the sheet production. It can be used as a base sheet for a ball and ball game machine, and can be used in general in the elastic game machine field including a pachinko game machine or a slot machine that hits a brass nail.

Claims (3)

As virgin material, methacrylic resin containing a multi-layer structure grains that Do acrylic rubber (A) 95 wt% to 40 wt% or more and,
As rework product contains an acrylic that Do rubber multi-layer structure grains, and the (A) methacrylic resin (B) different from the 5 wt% to 60 wt% or less and,
A methacrylic resin sheet containing
A resin base for a ball game machine, wherein the methacrylic resin sheet contains an acetone insoluble part of 15% by mass or more and 50% by mass or less.   The resin base for a ball game machine according to claim 1, wherein the methacrylic resin sheet has a yellowness (YI) of 4 or less at a sheet thickness of 10 mm. As virgin material, a methacrylic resin containing a multi-layer structure grains that Do acrylic rubber (A),
As rework products, containing a multi-layer structure grains that Do from acrylic rubber, and with the methacrylic resin different from (A) (B),
A method for producing a resin base for a ball game machine comprising a methacrylic resin sheet containing
The step of preparing the methacrylic resin sheet by adding 5 parts by mass or more and 150 parts by mass or less of the component (B) with respect to 100 parts by mass of the component (A),
A method for producing a resin base for a ball game machine, wherein the methacrylic resin sheet contains an acetone insoluble part of 15% by mass or more and 50% by mass or less.