JP2013188548A - Resin board for pinball game machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent Pachinko board surface capable of driving brass nails into a sheet surface without causing whitening or cracking, having superior nail holding force and cutting workability, and capable of preventing a sheet from becoming cloudy (due to high-temperature haze) due to a temperature rise in the board surface.SOLUTION: A resin board for a pinball game machine comprises a methacrylic resin sheet, comprising a transparent methacrylic resin containing a multi-layer structure particles of acrylic rubber, wherein the resin includes 15-50 wt.% of acetone-insoluble parts.

Description

  The present invention relates to a resin base for a ball game machine, and more specifically, without causing whitening or cracking around the hit nail after drilling the base surface with an NC processing machine (multi-axis drilling machine), and Further, the present invention relates to a resin base for a ball game machine comprising a transparent methacrylic resin sheet capable of suppressing white turbidity associated with a temperature rise of the base by incorporating a liquid crystal display device on the back of the base.

Currently, veneer plywood is the mainstream material for pachinko game boards (hereinafter sometimes referred to simply as game boards), but veneer plywood may have a cavity when the plates are bonded together with an adhesive. Due to this cavity, the holding force of the nail after driving the pachinko nail becomes uneven and weak, and the looseness of the nail may become a problem. In addition, because the veneer plywood material relies on imports, there are concerns about supply due to natural disasters in the supplying countries, environmental destruction caused by timber cutting, and various problems associated with imports. On the other hand, there is a demand for making the game board more interesting and attractive.
Therefore, in order to solve these problems and requirements, the material of the game board is replaced with a veneer plywood, a transparent methacrylic resin sheet, and further, a liquid crystal display device, an LED lighting device (light emitting diode), etc. are incorporated in this game board, It has been proposed to make it more interesting and attractive (for example, see Patent Documents 1 and 2).
However, when a pachinko nail is driven into the methacrylic resin sheet game board with an NC processing machine, there is a serious problem that cracks associated with microcracks occur around the nail.
In order to solve this, a method of improving impact resistance by blending methacrylic resin with multilayer structure particles made of acrylic rubber can be considered. However, when a liquid crystal display is attached to the methacrylic resin sheet of this game board (full liquid crystal display or partial liquid crystal display) is turned on, the temperature inside the game board rises, and it varies depending on the structure of the game board and the installation of the liquid crystal display device. The methacrylic resin sheet surface temperature on the liquid crystal side rises to about 40 ° C.
And as the biggest problem when blending methacrylic resin with multilayer structure particles made of acrylic rubber, the resin sheet becomes cloudy due to the difference in refractive index between methacrylic resin and acrylic rubber as the temperature rises. Haze problems occur. As for this problem, the haze value (cloudiness value) increases as the resin sheet thickness increases and the resin sheet thickness increases, and the liquid crystal screen becomes unclear and the illuminance decreases.
Therefore, without causing whitening or cracking around the hit nail, reducing the cloudiness of the resin sheet surface, and having nail retention and durability more than veneer plywood, other pachinko and other It contributes industrially as a resin base for general ball and ball machines including slot machines (hereinafter referred to as a resin base for ball and ball machines).

JP 2000-061047 A Japanese Patent Laid-Open No. 07-000614

The present invention improves the impact resistance by blending methacrylic resin with multilayer structure particles made of acrylic rubber, so that the methacrylic resin sheet base of the game board can be produced without causing whitening or cracking around the hit nail. An object of the present invention is to provide a resin base for a ball game machine that suppresses white turbidity of the resin sheet due to temperature rise, has excellent nail holding power and cutting workability, and has a stable material supply.

As a result of earnestly researching various members to replace the veneer plywood (Lawan material) as the material of the pachinko game board, the present inventors have used a transparent methacrylic resin sheet having a specific composition and having impact resistance, The present inventors have found that all the above problems can be solved and have completed the present invention.
That is, the present invention
[1] A methacrylic resin sheet comprising a transparent methacrylic resin containing multilayer structure particles made of acrylic rubber having an average particle diameter of 0.05 to 0.30 μm, and an acetone insoluble part of the resin being 15 to 50 % by weight A resin base for a ball game machine, wherein the thickness of the methacrylic resin sheet is 8 to 19 mm, wherein the base plate surface is perforated for nailing. ,
[2] The resin base for a ball game machine according to [1], wherein the resin has an average particle size of 0.10 to 0.30 μm ,
[3] The resin base for a ball game machine according to [1] or [2], wherein an acetone insoluble part of the resin is 19 to 29% by weight ,
[4] The resin base for a ball game machine according to any one of [1] to [3], wherein an acetone insoluble part of the resin is 24 to 29% by weight ,
[5] The resin base for a ball game machine according to any one of [1] to [4], wherein the methacrylic resin sheet has a tensile elastic modulus of 1500 to 2500 MPa. It is.

  The resin base for a ball game machine of the present invention has a structure in which a multilayer structure particle made of acrylic rubber is blended with a methacrylic resin without causing whitening or cracking around the hit nail and when a liquid crystal display device is attached. The high temperature haze can be reduced by increasing the temperature of the steel and the nail holding power and cutting workability are excellent.

The present invention will be described in detail below.
(1) Methacrylic resin The resin base for a ball game machine of the present invention is made of a transparent methacrylic resin containing multilayer structure particles made of acrylic rubber.
As the transparent methacrylic resin, a resin obtained by (co) polymerizing 70 to 100% by weight of methyl methacrylate and 30 to 0% by weight of a monomer copolymerized therewith is preferable.
The weight average molecular weight is preferably 80,000 to 220,000, and more preferably 90,000 to 200,000.

Monomers that can be copolymerized include methacrylic acid esters such as butyl methacrylate, ethyl methacrylate, propyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, 2-ethylhexyl methacrylate, methyl acrylate, ethyl acrylate, acrylic Examples thereof include acrylic acid esters such as butyl acid, cyclohexyl acrylate, phenyl acrylate, and 2-ethylhexyl acrylate, methacrylic acid, acrylic acid, styrene, and maleic anhydride.
The polymerization method is not limited at all, and a conventionally known method can be employed.

(2) Multilayer structured particles made of acrylic rubber Multilayer structured particles made of acrylic rubber used in the present invention (hereinafter sometimes simply referred to as acrylic rubber particles) are a central hard layer, a soft layer, and an outermost layer. Known acrylic rubber particles can be used as rubber particles having a three-layer structure composed of hard layers and a multilayer structure such as a four-layer structure having an intermediate hard layer between the soft layer and the outermost hard layer.
Specifically, the following acrylic rubber particles can be exemplified.

Example 1 (Japanese Patent Publication No. 60-17406):
“(A) A dispersion of a polymer mainly composed of methyl methacrylate having a glass transition point of 25 ° C. or higher by emulsion polymerization of methyl methacrylate alone or a mixture of methyl methacrylate and a monomer copolymerizable therewith. Forming a first layer,
(B) When this product is polymerized alone, it forms a copolymer having a glass transition point of 25 ° C. or lower, and is mainly composed of an alkyl acrylate, and further, a monomer and polyfunctionality copolymerizable therewith. A second layer step of emulsion polymerization by adding at least one of a crosslinking agent and a mixture containing 0.1 to 5% by weight of a polyfunctional grafting agent based on the total weight of the mixture, and (C) this product alone. A polymer having a glass transition point of 25 ° C. or higher when polymerized is formed, and a chain transfer agent is gradually increased to methyl methacrylate or a monomer mixture mainly composed of this, and emulsion polymerization is performed in multiple stages. A method for producing a multilayer structure acrylic resin molding material comprising a three-layer forming step, wherein the molecular weight of the third layer gradually decreases from the inside toward the outside. Multilayer structure particles made of acrylic rubber obtained by

Example 2 (JP-A-8-245854):
“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 in the outermost layer alone Acrylic multilayer structure polymer powder comprising a coagulated powder obtained by coagulating an emulsion latex of an acrylic multilayer structure polymer having a hard polymer layer containing a polymer having a Tg of 50 ° C. or higher when polymerized in The proportion of fine powder having a particle size of 212 μm or less after drying is 40% by weight, and the pore volume measured by mercury intrusion method of the solidified powder after drying is 0.7 cc or less per unit area Acrylic multilayer structure polymer powder. "

Example 3 (Japanese Patent Publication No. 7-68318):
“(A) 90 to 99% by weight of methyl methacrylate, 1 to 10% by weight of alkyl acrylate having 1 to 8 carbon atoms in the alkyl group, and allyl, methallyl of α, β-unsaturated carboxylic acid copolymerizable therewith, Or innermost hard layer polymer 25 to 45% by weight obtained by polymerizing a monomer mixture consisting of 0.01 to 0.3% by weight of at least one graft-bonding monomer selected from crotyl ester,
(B) In the presence of the innermost hard layer polymer, 70 to 90% by weight of n-butyl acrylate, 10 to 30% by weight of styrene, and allyl, methallyl of α, β-unsaturated carboxylic acid copolymerizable therewith, Or 35 to 45% by weight of a soft layer polymer obtained by polymerizing a monomer mixture consisting of 1.5 to 3.0% by weight of a graft-bondable monomer consisting of at least one selected from crotyl esters,

(C) In the presence of the polymer composed of the innermost hard layer and the soft layer, a monomer mixture obtained by polymerizing 90 to 99% by weight of methyl methacrylate and 1 to 8 carbon atoms of the alkyl group is obtained. The outer hard layer polymer is composed of 20 to 30% by weight,
(D) The weight ratio of soft layer polymer / (innermost hard layer polymer + soft layer polymer) is 0.45 to 0.57,
(E) A multilayer structure acrylic polymer having an average particle size of 0.2 to 0.3 μm, and when the multilayer structure acrylic polymer is further fractionated with acetone,
(F) The graft ratio is 20 to 40% by weight,
(G) A multilayer structure acrylic polymer, wherein the acetone insoluble portion has a tensile elastic modulus of 1000 to 4000 kg / cm ² . "

Other examples of acrylic rubber particles having a three-layer to four-layer structure include Japanese Patent Publication No. 55-27576, Japanese Patent Publication No. 58-1694, Japanese Patent Publication No. 59-36645, Japanese Patent Publication No. 59-36646, and Japanese Patent Publication No. 62. -41241, JP-A-59-202213, JP-A-63-27516, JP-A-51-129449, JP-A-52-56150, application S50-124647, etc. Acrylic rubber particles can also be used.
Examples of the acrylic rubber particles used in the present invention include “IR377 (trade name)” and “Rubber IR441 (trade name)” manufactured by Mitsubishi Rayon Co., Ltd.

(3) Acetone insoluble part (wt%)
A part of the transparent methacrylic resin sheet is precisely weighed (W1) and placed in a centrifuge tube, and then acetone is added and dissolved to remove the acetone soluble part. The solvent is removed in a vacuum dryer and cooled, and the weighed residue is defined as an acetone insoluble part (W2).
The blended amount of rubber and the acetone insoluble part do not match, and even if the rubber particle structure (outermost hard layer: dissolved in acetone) is the same, the physical properties obtained are different. Defined as insoluble part.
The acetone insoluble part (% by weight) (X) is calculated by the following formula.
Acetone insoluble part (X) = (W2 / W1) × 100
The acetone insoluble part in the methacrylic resin of the present invention has optical properties (total light transmittance, high-temperature haze), tensile elastic modulus, pencil hardness, after nailing (whether whitening has occurred, whether cracks have occurred), and retention during nail removal From the viewpoint of force and machinability, it is 15 to 50% by weight, preferably 20 to 45% by weight.

(4) Average particle diameter of acrylic rubber particles (μm)
A part of the transparent methacrylic resin sheet is cut out, and the average diameter of the section of the stained rubber particles is determined as the average particle diameter of the rubber particles by the RuO ₄ (ruthenic acid) dyeing ultrathin section method.
The average particle diameter of the acrylic rubber particles used in the present invention is preferably 0.05 to 0.30 μm, more preferably 0.05 to 0.25 μm, and still more preferably 0.18 to 0.25 μm.
If the particle size is less than 0.05 μm, the substrate is easily cracked, and if it is more than 0.30 μm, rubber elasticity is added when a certain amount or more (amount that the acetone insoluble part is 65% by weight or more) is added. Not expressed as a body, impact value and tensile modulus decrease. Further, from the viewpoint of high-temperature haze accompanying the temperature rise of the sheet, the average particle size of the acrylic rubber particles is most preferably 0.18 to 0.25 μm.

(5) Manufacturing method of methacrylic resin sheet As a manufacturing method of the transparent methacrylic resin sheet of the present invention, both the extrusion sheet method and the cast sheet method can be adopted. The extrusion sheet method is preferred.
The transparent methacrylic resin sheet of the present invention has impact resistance, and pachinko nails (especially well) in the case of a sheet having a thickness of 5 to 15 mm when drilling holes on the sheet surface with an NC processing machine (multi-axis drilling machine). In particular, brass pachinko nails) can be driven, and pachinko nails can be driven up to a thickness of 19 mm.
From this, it can be said that the transparent methacrylic resin sheet of the present invention has a nailing processability higher than that of a veneer plywood.
The pachinko nails are made of brass, iron, stainless steel, etc., but brass is most preferred, and brass nails have no screw or have a screw, but can be used properly depending on the purpose. Is preferably provided with a screw, and its holding force is more than that when used for veneer plywood.

The tensile elastic modulus of the methacrylic resin sheet of the present invention is preferably 1200 to 2500 MPa, more preferably 1500 to 2400 MPa. When the tensile elastic modulus is 2500 MPa or less, whitening and cracking are not observed after nailing on the sheet surface, and when it is 1200 MPa or more, the rigidity and hardness (hardness) of the sheet are improved and the surface is hardly damaged.
The high-temperature haze value (cloudiness value) at a sheet surface temperature of 40 ° C. when the methacrylic resin sheet of the present invention is 10 mm thick is preferably 5% or less. If it is 5% or less, the cloudiness of the sheet is not visually recognized, the total light transmittance is improved, and at the same time, the liquid crystal display becomes bright and easy to see.
5-19 mm is preferable and, as for the methacryl resin sheet thickness of this invention, More preferably, it is 8-12 mm. If the sheet thickness is 5 mm or more, the holding power at the time of nail removal on the sheet surface is improved, and if it is 19 mm or less, the total light transmittance and the high-temperature haze value are lowered, and the liquid crystal display is likely to be bright and visible.

The following characteristic tests were carried out for the following Examples 1 to 7, Reference Examples 8 and 9, and Comparative Examples 1 to 5.
As characteristic test items, acetone insoluble part for grasping the rubber component of the transparent methacrylic resin sheet, average particle diameter of acrylic rubber particles, in addition to this, optical characteristics [total light transmittance, high temperature haze (cloudiness) ] Comparative evaluation was carried out with respect to tensile modulus, nailing (whether whitening occurred, cracks occurred), nailing (holding force), and machinability.

(1) Acetone insoluble part After drying the transparent methacrylic resin sheet all day and night (about 80 ° C., about 12 hours or more), a part of the sheet is cut out and weighed about 1.0 g (W1), and then into a centrifuge tube (metal tube). After adding the sample, 20 ml of acetone is added and the mixture is allowed to stand at room temperature for about 1 day, and then shaken for 2 hours on a shaker. Next, vacuum type high-speed cooling centrifuge manufactured by Hitachi Koki Co., Ltd. Model: Use CR26H, set the conditions at 5 ° C. and 24000 rpm, and centrifuge for 1 hour.

After shaking, the supernatant is removed by decantation, and 20 ml of acetone is newly added and shaken at room temperature for 1 hour. After shaking, centrifuge for 1 hour at 5 ° C. and 24000 rpm. Again, the same method and conditions were repeated a total of 3 times. Decant the supernatant and air dry overnight.
The vacuum dryer was set to 100 ° C., taken out after vacuum drying all day and night (about 12 hours or longer), cooled to room temperature in a desiccator, and the weight of the residue was weighed (W2).
The acetone insoluble part (% by weight) is calculated by the following formula (X).
Acetone insoluble part (X) = (W2 / W1) × 100

(2) Average particle diameter of acrylic rubber particles A part of a transparent methacrylic resin sheet was cut out with a circular saw, and then a sample for observation by a RuO ₄ (ruthenic acid) dyed ultrathin section method was prepared. Transmission electron microscope manufactured by Hitachi, Ltd. Model: H-600 type was used, and the stained rubber particle cross section was observed and photographed. The diameter of 20 representative particles printed at high magnification was measured on a scale to determine the average particle size.

(3) Optical characteristics (1) Total light transmittance: In accordance with the method defined in JIS K 7105 “Testing methods for optical characteristics of plastics”, a resin sheet is cut into a sample size of 50 × 50 mm, and then Nippon Denshoku Industries Co., Ltd. ) Turbidimeter model: measured using 1001 DP.
(2) High-temperature haze value (cloudiness value): According to the method defined in JIS K 7105 “Testing methods for optical properties of plastics”, a resin sheet is cut into a sample size of 50 × 100 mm, and then one end of the sheet surface ( Paste the tip of the thermocouple using heat-resistant tape to about 40 mm from the light source side of the device body), put the sheet in a container and leave it in a dryer set at about 80 ° C for about 2 hours or more , Close the lid of the container, take it out quickly and install a turbidimeter (23 ° C x 50 ° C)
% RH), the temperature drop is suppressed, the turbidity meter model: 1001DP manufactured by Nippon Denshoku Industries Co., Ltd. is set, and the sheet surface temperature is 40 ° C. while the sheet surface temperature is naturally cooled. The haze value was measured and determined. The average value of the test results of two times for each was determined.

(4) Tensile modulus The transparent methacrylic resin and acrylic rubber particles were mixed in a tumbler (mixer) (30 revolutions / minute) so as to be uniform for about 15 minutes.
Next, this resin mixture was supplied to a 30φ twin screw extruder (manufactured by Nakatani Machinery Co., Ltd.) and pelletized (pelletizer) was used. A test piece was prepared by attaching a single mold. After adjusting the state of the test piece (at a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 5% for 48 hours or longer), the test piece was used in ISO test method 527-2 / 1A / 1 to measure the tensile modulus.
The transparent polycarbonate resin sheet was extracted from the technical data of trade name “Lexan” manufactured by Asahi Glass Co., Ltd. and described.

(5) Pencil hardness: In accordance with the method defined in JIS K 5400 “General test method for paints”, after cutting the sheet into a sample size of 100 × 150 mm, leaving it 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., scratch angle: 45 degrees Load (weight): Measured under the conditions of 1 kg.
(6) After nailing (whether whitening occurs, cracks occur)
Prepare a sheet size of 50 x 150 mm, drill 10 or more holes through a drilling machine using a straight shank drill φ1.73 mm, brass nails φ1.83 mm, total length 33.3 mm, and head length 31.2 mm After setting a nail in the center of the hole with a brass pachinko nail (no screw) with a taper of 3 mm and φ 1.83 mm, using an Instron Japan model 5582 (floor model) testing machine, speed of 50 mm per minute The nail was struck and penetrated through the parallel part of the nail with respect to the sheet thickness (13 mm when the sheet thickness was 10 mm), and then the presence or absence of whitening around the nail and the presence or absence of cracks were evaluated. For veneer plywood, 16.5 mm was directly nailed to the surface using a plywood thickness of 19 mm.

(7) When nailing (holding force)
Using the sample after nailing obtained in (6), model 5582 (floor model) manufactured by Instron, the nail head was fixed to the chuck, and the nail was pulled out at a speed of 50 mm per minute. The maximum load (kg) was obtained.
(8) Machinability ○ Use the NC processing machine and drill blade to set the conditions for woodworking (veneer plywood), then perform the cutting process and there is no problem. △ is attached when the is attached, and × is attached when it is clearly attached.
Next, while showing the manufacture examples 1-3 of an acrylic rubber particle, this invention is demonstrated based on an Example and a comparative example.

<Production Example 1>
Ion-exchanged water 6860 ml and sodium dihexyl sulfosuccinate 13.7 g were put into a reactor with a reflux condenser with an internal volume of 10 L, and the temperature was raised to 75 ° C. under a nitrogen atmosphere while stirring at a rotational speed of 250 rpm. There was virtually no state.
Of the mixture (I-1) consisting of MMA 907 g, BA 33 g, HMBT 0.28 g and ALMA 0.93 g, 222 g was added all at once, and after 5 minutes, 0.22 g of ammonium persulfate was added. Forty minutes later, the remaining 719 g of (I-1) was continuously added over 20 minutes and held for another 60 minutes after the addition was completed. Next, 1.01 g of ammonium persulfate was added and then 1067 g of BA, St219 g, HMBT0 A mixture (I-2) consisting of .39 g and 27.3 g of ALMA was continuously added over 140 minutes, and was further maintained for 180 minutes after the addition was completed.

Next, after adding 0.30 g of ammonium persulfate, a mixture (I-3) consisting of MMA 730 g, BA 26.5 g, HMBT 0.22 g, and n-OM 0.76 g was continuously added over 40 minutes. The temperature was raised to ° C. and held for 30 minutes.
The remaining latex was poured into a 3% by weight aqueous solution of sodium sulfate, salted and coagulated, and then dried after repeated dehydration and washing to obtain a multilayer acrylic polymer (I).
The above abbreviations indicate the following compounds.
MMA; methyl methacrylate, BA; n-butyl acrylate, St; styrene, MA; methyl acrylate, ALMA; allyl methacrylate, PEGDA; polyethylene glycol diacrylate (molecular weight 200 or 600), n-OM; n-octyl mercaptan, HMBT; 2- (2'-Hydroxy-5'-methylphenyl) benzotriazole

<Production Example 2>
In a 10 L beaker equipped with a stirrer and a condenser, 5.7 L of distilled water, 20 g of sodium dioctylsulfosuccinate as an emulsifier, and Rongalite l. Add 2g and dissolve uniformly. As the first layer, 220 g of methyl methacrylate (hereinafter abbreviated as MMA), 30 g of n-butyl acrylate (hereinafter abbreviated as BA), 0.8 g of allyl methacrylate (hereinafter abbreviated as ALMA), diisopropylbenzene hydroperoxide (hereinafter abbreviated as PBP) 0 .2 g of homogeneous solution was added and polymerized at 80 ° C. The reaction was complete in about 15 minutes.
The obtained polymer had a Tg of 108 ° C. Next, as a second layer, a uniform temperature of 1270 g of BA, 320 g of styrene (hereinafter abbreviated as st), 20 g of diethylene glycol diacrylate (hereinafter abbreviated as DEGA), 13.0 g of ALMA, and 1.6 g of PBP was dropped over 1 hour. The reaction was completed 40 minutes after the completion of the dropwise addition. The Tg of the polymer obtained by polymerizing this product alone was -38 ° C.

Next, a uniform solution of BA 2.0 g, PBP 0.3 g and n-octyl mercaptan (hereinafter abbreviated as OM) 0.1 g was added to MMA 340 g as the third layer, and this was obtained by polymerizing alone. The molecular weight of the polymer was 1,220,000 and Tg was 109 ° C. The reaction at this stage was complete in about 15 minutes.
Next, a solution having the same composition as the first layer of the third layer was added except that the amount of OM was changed to 1.0 g as the second layer of the third layer. The polymer obtained by polymerizing this product alone had a molecular weight of 117,000 and a Tg of 108 ° C. This step was complete in about 15 minutes. Next, the temperature was raised to 95 ° C. and held for 1 hour. The obtained emulsifier was put into a 0.5% aluminum chloride aqueous solution to aggregate the polymer, washed 5 times with warm water, dried and dried to form white flocs. A molding material was obtained.

<Production Example 3>
Of the mixture (I-1) consisting of MMA907g, BA33g, HMBT0.28g and ALMA0.93g with the same mixture constituting (I-1), (I-2) and (I-3) of Production Example 1 The procedure was exactly the same as in Production Example 1, except that 222 g was added all at once and 0.22 g of ammonium persulfate was added 1.5 minutes later to accelerate the polymerization initiation reaction and increase the particle size.

[Example 1]
About 80% by weight of methacrylic resin (trade name “Del powder: 70H beads” manufactured by Asahi Kasei Chemicals Co., Ltd.) and 20% by weight of acrylic rubber particles of Production Example 1 in a tumbler (mixer) (30 rpm). Rotate for 15 minutes and mix uniformly.
Next, this resin mixture was supplied to a 30φ twin-screw extruder (manufactured by Nakatani Machinery Co., Ltd.) and pelletized (granulator).
Subsequently, the obtained pellets were supplied to a sheet extruder (Pura Giken 50 mmφ, L / D = 32) and extruded into a sheet having a thickness of 10 mm and a width of 250 mm.
From the obtained sheet, the above-mentioned sample for characteristic test items (excluding tensile elastic modulus) was cut out using a circular saw and measured according to each evaluation item.
The tensile elastic modulus was measured using the above (4) tensile elastic modulus.

[Example 2]
A sample for evaluation was obtained by the same method as in Example 1 except that 30% by weight of acrylic rubber particles was blended with 70% by weight of methacrylic resin, and measurement was performed according to each evaluation item.
[Example 3]
A sample for evaluation was obtained by the same method as in Example 1 except that 50% by weight of acrylic rubber particles were blended with 50% by weight of methacrylic resin, and measurement was performed according to each evaluation item.
[Example 4]
A sample for evaluation was obtained by the same method as in Example 2 except that the acrylic rubber particles of Production Example 2 were used, and measurement was performed according to each evaluation item.
[Example 5]
A sample for evaluation was obtained by the same method as in Example 2 except that the acrylic rubber particles of Production Example 3 were used, and measurement was performed according to each evaluation item.

[Example 6]
Samples for evaluation were obtained in the same manner as in Example 2 except that product name (trade name) IR377 (multi-layer structured particle of flaky acrylic rubber) manufactured by Mitsubishi Rayon Co., Ltd. was used as the acrylic rubber particles. Measured according to
[Example 7]
Samples for evaluation were obtained in the same manner as in Example 2 except that product name (trade name) IR441 (multilayer structure particle of flaky acrylic rubber) manufactured by Mitsubishi Rayon Co., Ltd. was used as the acrylic rubber particles. Measured according to
[ Reference Example 8]
A sample for evaluation was obtained by the same method as in Example 1 except that the compounded formulation of Example 2 was extruded into a sheet having a thickness of 5 mm and a width of 250 mm by a sheet extruder, and measurement was performed according to each evaluation item. However, since the sheet thickness was 6 mm, the nail driving amount was 9 mm.

[ Reference Example 9]
A sample for evaluation was obtained by the same method as in Example 1 except that the compounded formulation of Example 2 was extruded into a sheet having a thickness of 3 mm and a width of 250 mm by a sheet extruder, and measurement was performed according to each evaluation item. However, since the sheet thickness was 3 mm, the nail driving amount was 6 mm.
[Comparative Example 1]
A sample for evaluation was obtained by the same method as in Example 1 except that acrylic rubber particles were not blended, and measurement was performed according to each evaluation item.

[Comparative Example 2]
A sample for evaluation was obtained by the same method as in Example 1 except that 10% by weight of acrylic rubber particles was blended with 90% by weight of methacrylic resin, and measurement was performed according to each evaluation item.
[Comparative Example 3]
A sample for evaluation was obtained by the same method as in Example 1 except that 70% by weight of acrylic rubber particles was blended with 30% by weight of methacrylic resin, and measurement was performed according to each evaluation item.

[Comparative Example 4]
Instead of a methacrylic resin sheet, a commercially available transparent polycarbonate resin sheet (trade name: Lexan, plate thickness 10 mm manufactured by Asahi Glass Co., Ltd.) was obtained and measured according to each evaluation item.
[Comparative Example 5]
It measured according to each evaluation item using only the board thickness 19mm veneer plywood (Lawan material) of the present use. However, in the case of veneer plywood, 16.5 mm was directly nailed to the plywood surface without drilling with a drilling machine.
Table 1 shows the results of Examples 1 to 7, Reference Examples 8 and 9 and Comparative Examples 1 to 5.

  The resin base for a ball game machine according to the present invention is applicable to the general field of elastic game machines including a pachinko game machine in which holes are drilled on a game board surface with an NC machine and hit with brass nails. Then, by installing a liquid crystal device on the transparent methacrylic resin sheet of the present invention, the gaming machine board surface can be partially or entirely liquid crystallized. Moreover, it is possible to emit light on the surface of the sheet by attaching an LED illumination or a cold cathode tube with the end face of the sheet by a light guide plate method, which is extremely effective in the industry. Furthermore, the present invention can be applied to fields such as building materials utilizing a resin material that requires nailing on the sheet surface.

Claims (5)

It consists of a transparent methacrylic resin containing multilayer structure particles made of acrylic rubber having an average particle diameter of 0.05 to 0.30 μm, and consists of a methacrylic resin sheet whose acetone insoluble part is 15 to 50 % by weight, A resin base for a ball game machine in which the thickness of the methacrylic resin sheet is 8 to 19 mm, wherein the base plate is perforated for nailing . 2. The resin base for a ball game machine according to claim 1, wherein an average particle diameter of the resin is 0.10 to 0.30 [mu] m. The resin base for a ball game machine according to claim 1 or 2, wherein an acetone insoluble part of the resin is 19 to 29% by weight. The resin base for a ball game machine according to any one of claims 1 to 3, wherein an acetone insoluble part of the resin is 24 to 29% by weight. The resin base for a ball game machine according to any one of claims 1 to 4, wherein the methacrylic resin sheet has a tensile elastic modulus of 1500 to 2500 MPa.