JP6482441B2 - Luminous resin composition, luminous resin molded article, and method of producing luminous master pellet - Google Patents

Description

  The present invention relates to a phosphorescent resin molded article in which the color dullness of molded articles and the decrease in afterglow luminance are suppressed, a luminous resin composition used for the same, and a method of producing a luminous master pellet.

A phosphorescent pigment is a phosphor having an afterglow property of emitting light by ultraviolet light or visible light and emitting light even after removing the excitation light, and this light emission is also commonly referred to as phosphorescence.
Phosphorescent pigments are widely used in building materials, road signs, anti-slip, cushions, fishing tackles, stationery and the like for disaster prevention and safety indication by taking advantage of the above characteristics. Conventionally, the form of a phosphorescent ink has been the mainstream in the past, but the use of a resin molded body in which a phosphorescent pigment is contained in a thermoplastic resin has been widely spread and application development is progressing recently.
As the thermoplastic resin, polyolefin resins such as polyethylene and polypropylene resins, styrene resins such as polystyrene and ABS; polycarbonate resins; acrylic resins such as polymethyl methacrylate; polyvinyl resins; Various resins such as polyester resins such as polyethylene terephthalate are used.
On the other hand, the luminous pigment is different in bulk density and shape, and in the production of a master pellet by a conventional pellet mill and the method of producing a molded product by extrusion molding, there is a problem that the phosphorescent pigment is broken. When the phosphorescent pigment is disintegrated, the luminance is reduced. Therefore, in order to ensure sufficient light emission luminance and light emission persistence from the viewpoint of securing safety, an extra amount of phosphorescent light is added to compensate for the decrease in luminance. There must be. Phosphorescent pigments are generally expensive materials, and excessive blending is extremely industrially disadvantageous (Patent Document 1, Patent Document 2).
The molded object which mix | blended the said luminous pigment in the thermoplastic elastomer is well-known. However, it is not a method in which a luminous master pellet is first produced using a thermoplastic elastomer and then formed into a formed body, but suddenly formed into a formed body by extrusion (simultaneous) forming (Patent Document 3).

Patent No. 3947619 gazette Unexamined-Japanese-Patent No. 2004-182841 JP 2004-315687 A

  The present invention relates to a phosphorescent resin composition and a phosphorescent master pellet using the composition, which suppresses degradation of a phosphorescent pigment during molding to prevent color dullness and light emission (afterglow) luminance due to degradation. The purpose is to provide a manufacturing method of

  As a result of intensive studies on resin compositions and methods suitable for producing master pellets, the present inventors selected a thermoplastic elastomer as a thermoplastic resin, and moreover, a molding in which as little shear stress as possible was applied to a molding melt during molding It has been found that the degradation of the phosphorescent pigment is suppressed by adopting the method, and the present invention has been completed.

According to the present invention, a composition containing 5 to 40 parts by weight of the luminous pigment per 100 parts by weight of the thermoplastic elastomer is kneaded and formed by a compression molding method or a roll molding method to produce a luminous master pellet, There is provided a method for producing a phosphorescent resin molded article, which comprises mixing and molding the luminous master pellet and the thermoplastic resin .
Thermoplastic elastomer, it is preferable that a transparent thermoplastic elastomer.

The luminous resin composition provided by the present invention can prevent the collapse of the luminous pigment contained in the production of the master pellet. As a result, the luminous resin molded article manufactured using the said master pellet as a raw material has little fall of luminous brightness, and it is not necessary to mix | blend excess luminous pigment.
Furthermore, as a method of producing a master pellet from the above-mentioned luminous resin composition, a kneading molding method by compression molding or roll molding is most preferable from the viewpoint of suppressing the collapse of the luminous pigment to the maximum extent.

  The luminous resin composition of the present invention is a composition used for producing a master pellet, which is a composition comprising a thermoplastic elastomer and a luminous pigment, and is 5 to 40 per 100 parts by weight of the thermoplastic elastomer. It contains parts by weight of a phosphorescent pigment. Each component will be described below.

[Thermoplastic elastomer]
It is important for the luminous resin composition of the present invention to use a thermoplastic elastomer as a resin component. By using such a thermoplastic elastomer, it is possible to suppress the disintegration of the phosphorescent pigment in the composition much more than other thermoplastic resins in producing a master pellet. It is considered that the thermoplasticity of the thermoplastic elastomer at high temperature and the properties of rubber elasticity at normal temperature contribute to the suppression of the collapse.
The thermoplastic elastomer is not particularly limited as long as the above properties at high temperature and normal temperature are exhibited as the thermoplastic elastomer, but in order for the phosphorescent resin molded body obtained by the present invention to sufficiently exhibit the light emission luminance due to phosphorescence, the thermoplastic thermoplasticity is transparent. It is preferably an elastomer. In the present invention, transparency means that the total light transmittance is 85% or more, specifically 85 to 93%.
The thermoplastic elastomer includes, for example, an olefin-based thermoplastic elastomer having rubber elasticity in which an olefin-based rubber such as ethylene propylene rubber or ethylene propylene diene rubber is finely dispersed in a matrix using PP or PE as a matrix. Since many olefin thermoplastic elastomers are commercially available, they can be purchased and used in consideration of MFR and the like. For example, various MFRs and resins having various physical properties are sold by Mitsubishi Chemical Co., Ltd. under the trade name "Thermal" or "Zerus".
In addition, styrene-based thermoplastic elastomers having a block copolymer of styrene and butadiene or a block copolymer of styrene and ethylene and butylene as a basic structure may be mentioned, and Kuraray under the trade name "TAFTEC" from Asahi Kasei Chemicals Corporation. It is marketed by Aron Chemical Co., Ltd. as the "AR-SC series" as "Septon" or "Hybuller".
Further, acrylic thermoplastic elastomers having a basic structure of a block copolymer of methyl methacrylate and butyl acrylate may be mentioned, and are commercially available from Kuraray Co., Ltd. under the trade name "Klarity". Other polyurethane thermoplastic elastomers and polyvinyl chloride thermoplastic elastomers can also be used. "Tough Tech", "AR-SC series" and "Klarity" are thermoplastic elastomers having excellent transparency and are suitable elastomers.

[Phosphorescent pigment]
The phosphorescent pigment is not particularly limited, and is represented by a sulfide-based pigment such as zinc sulfide / copper phosphor (ZnS: Cu), CaSrS: Bi, or the general formula MAl ₂ O ₄ (M is calcium, barium, strontium, etc.) An aluminate pigment containing an activator such as europium (Eu) or neodymium (Nd) as needed, specifically, CaAl ₂ O ₄ : Eu, Nd (emission peak wavelength: 440 nm), SrAl ₂ 0 ₄ : Eu, Dy (emission peak wavelength: 520 nm), SrAl ₂ 0 ₄ : Eu (emission peak wavelength: 520 nm), and others, Sr ₄ Al ₁₄ 0 ₂₅ : Eu, Dy (emission peak wavelength: 490 nm) and the like. These phosphorescent pigments are commercially available from moto lumi materials and the like.

[Luminescent resin composition]
The luminous resin composition of the present invention includes, in addition to the above-mentioned essential components, an inorganic or organic filler, a flame retardant, a stabilizer, an ultraviolet light absorber, a plasticizer, a lubricant and the like to the extent that the characteristics of the present invention are not impaired. Various additives, and further, colorants such as dyes and pigments can be optionally blended.
The method of mixing the above-mentioned essential and optional components to form a resin composition is not particularly limited and can be carried out by a known method. Usually, mixing is performed using a mixer such as a Henschel mixer.
The said resin composition dry-blends each component, makes it exist in a mixed state, and is used as a raw material for master pellets.

[Manufacturing method of master pellet]
The present invention is characterized in the method of producing a master pellet from the luminous resin composition. That is, in order to suppress the degradation of the phosphorescent pigment in the composition as much as possible, it is important to adopt a kneading and molding method of compression molding or roll molding. When a master pellet is produced by a conventional extrusion mold pellet mill, the shearing stress is large and the phosphorescent pigment is broken, and the light emission luminance of the obtained molded article is lowered. The same disintegration occurs also in the case of producing a molded body by an extruder.
Compression molding is a method of heating and melting under pressure in a mold, followed by cooling and forming into a sheet, and roll forming is rolling gradually between the heat rolls of the calender section to form a sheet or a film. In any of the methods, the shear stress applied to the melt is small, and the collapse of the phosphorescent pigment is suppressed. Existing devices as well as conventionally known conditions are widely adopted.
The sheet-like compact obtained by compression molding or roll molding is cut by a pelletizer or the like to be pelletized to form a luminous master pellet.

[Luminous resin molding]
The obtained luminous master pellet can be formed into a molded body of a predetermined shape mixed and molded with a thermoplastic resin described below. The compounding ratio of the luminous master pellet to the thermoplastic resin is arbitrarily determined from the content ratio of the luminous pigment in the master pellet and the content ratio of the luminous pigment desired in the final molded body. Usually, 2 to 20 parts by mass of the phosphorescent pigment is blended per 100 parts by mass of the molded body. In addition, a compact | molding | casting may be produced only by luminous master pellet.
The thermoplastic resin can be optionally selected from acrylic resin, polyamide resin, polyethylene resin, polypropylene resin, polyvinyl chloride resin, polystyrene resin, polycarbonate resin, ABS resin, etc. according to the use of the final product and the necessary physical properties.
Once a master pellet free of disintegration of the phosphorescent pigment is obtained, when the mixture is molded with a thermoplastic resin thereafter, disintegration of the phosphorescent pigment hardly occurs. Therefore, the molding method of the luminous resin molded product is not particularly limited, and conventionally known molding methods such as injection molding, blow molding, compression molding, cast molding, and extrusion molding can be adopted.

  The invention is further illustrated by the following examples. The following examples are for illustrative purposes and the invention is not limited in any way. Furthermore, not all combinations of features described in the embodiments are necessarily essential to the solution of the present invention.

The various components and abbreviations used in the following examples and comparative examples are as follows.
(A) Thermoplastic Elastomer:
A-1: "Amzel AZ180" made by Plastech Co., Ltd. Acrylic elastomer A-2: "AR-SC-75" made by Aron Kasei Co., Ltd. Styrene elastomer (B) luminous pigment B-1: "GLL made by Nemoto Lumimaterials Co., Ltd. -300FF ".. SrAl ₂ 0 ₄ : Eu, Dy
B-2: "BGL-300FF" made by Nemoto Lumimaterials, · · Sr ₄ Al ₁₄ 0 ₂₅ : Eu, Dy
(C) Thermoplastic resin C-1: Vinyl chloride resin "841 J" manufactured by Showa Kasei Kogyo Co., Ltd.
Density: 1.10 g / cm ³ Melt flow rate: 1.0 g / 10 min
C-2: ABS resin "ST600" made by Nippon A & L Co.
Density: 1.10 g / cm ³ ,
Melt volume flow rate: 3.0cm ³ / 10min
(D) Other resins D-1: Hard acrylic resin "Acripet VH" manufactured by Mitsubishi Rayon
Density: 1.19 g / cm ³ Melt flow rate: 2.0 g / 10 min

Example 1
[Manufacturing method of luminous wood master pellet]
According to the formulation shown in Table 1, a luminous resin composition comprising 100 parts by mass of a thermoplastic elastomer “acrylic elastomer (A-1)” and 25 parts by mass of a luminous pigment “GLL-300FF” is introduced into a roll molding machine , A sheet having a width of 1000 mm and a thickness of 2 mm was produced (roll).
The obtained sheet was used to produce a master pellet of about 3 mm × about 3 mm × 2 mm using a cutter.
[Production of Luminous Resin Molding]
125 parts by mass of the master pellet obtained by the above method was mixed with 125 parts by mass of vinyl chloride resin (C-1) in an extrusion molding machine to prepare a 200 mm × 20 mm × 4 mm luminous resin molded body.

A test piece (about 3 mm × about 3 mm × 2 mm) was cut out from a part of the obtained molded body, and each physical property was measured by the following method. The results are shown in Table 1.
(1) Afterglow test
The used devices and conditions for measuring afterglow luminance in accordance with JIS Z 9107 are shown below.
<Used equipment>
Light source: Common light source D65 F65D-A (Suga Test Machine)
Light meter: T-10P (JIS C1609-1: 2006 AA grade compliant, Konica Minolta)
Brightness meter: BM-5A (TOPCON)
<Measurement condition>
Excitation conditions: Normal light source D65 fluorescent lamp 200 lx, 20 minutes Measurement: Afterglow luminance up to 300 minutes after excitation stop Background color: black environmental temperature humidity: 23 ± 2 ° C., 50 ± 10%
<Afterglow brightness evaluation>
○: The remaining luminance after 60 minutes is 10 mcd / m ² or more
X: The remaining luminance after 60 minutes is less than 10 mcd / m ²
(2) Visual appearance evaluation O: The luminous pigment was uniformly dispersed, and good luminescence was observed.
X: Luminescent pigment is crushed and discolored, and light emission also becomes dark.

Comparative Examples 1 and 2
In Comparative Examples 1 and 2, a sheet-like luminous resin molded article was produced by direct extrusion molding without producing a master pellet, and then a test piece was cut out from the molded article for measurement. The results are shown in Table 1.

Examples 2 to 9, Comparative Example 3
In Examples 2 to 9 and Comparative Example 3, according to the formulation shown in Table 1, luminous resin molded articles were produced according to Example 1 and the physical properties thereof were also measured in the same manner. The results are shown in Table 1.

Example 1, 2 and 5-9 produced the master pellet, respectively using the acrylic elastomer and Example 3, 4 using the styrene-type elastomer. Furthermore, in Examples 1 to 5, 8 and 9, a molded article having a vinyl chloride resin as a base material and a molded article having an ABS resin as a base material in Example 7 using these master pellets are examples of Example 6 A compact was produced with the master pellet alone.
The afterglow luminance after 60 minutes in Example 1 was 21.7 mcd / m ² (911.8 mcd / m ² after 1 minute). The afterglow luminance after 60 minutes in Example 2 was 17.8 mcd / m ² (385.5 mcd / m ² after 1 minute). Also in Examples 3 to 9, the afterglow luminance after 60 minutes was 10 mcd / m ² or more, and sufficient luminous performance was maintained for a long time. In any of the examples, the phosphorescent pigment was uniformly dispersed and good color development was observed.
In Comparative Examples 1 and 2, instead of the thermoplastic elastomer, a hard acrylic resin was used to form an extrusion molding method. In the molded product, the phosphorescent pigment was crushed and discolored, and the afterglow luminance was greatly reduced. In Comparative Example 3, a master pellet was produced using a hard acrylic resin in place of the thermoplastic elastomer, and then the master pellet was blended with a vinyl chloride resin as a base material to produce a molded body. Although the afterglow luminance and visual evaluation were slightly better than that of Comparative Examples 1 and 2 in the molded product, sufficient effects could not be obtained, and the afterglow luminance did not exceed 10 mcd / m ² .

Claims (2)

A composition containing 5 to 40 parts by weight of the luminous pigment per 100 parts by weight of the thermoplastic elastomer is kneaded and formed by a compression molding method or a roll molding method to produce a luminous master pellet, and then the luminous master pellet and the thermal master pellet A method for producing a luminous resin molded product, comprising mixing with a plastic resin and molding . The thermoplastic elastomer is a transparent thermoplastic elastomer, The manufacturing method of the luminous resin composition of Claim 1 characterized by the above-mentioned.