JP2002019065A - Resin molding and light reflector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin molding having excellent heat resistance, productivity, fracture resistance and light reflecting performance and a light reflector contributing to a reduction of a power consumption when used for an electric decoration signboard or the like. SOLUTION: The resin molding comprises a multilayer structure including a mixed resin layer containing an aromatic polycarbonate resin (A) of 35 to 75 wt.%, a thermoplastic resin or/and a thermoplastic elastomer (B) of 5 to 45 wt.% except the aromatic polycarbonate resin, and a flame retardant (C) of 0 to 35 wt.% and a white pigment (D) of 0 to 15 wt.% (wherein (A)+(B)+(C)+(D)=100 wt.%). A rear layer containing a synthetic resin or a synthetic resin composition having an Izod impact value of at least 5 kJ/m2 and is integrally adhered to the rear surface of the mixed resin layer, in such a manner that a total reflectivity of a parameter for representing a reflection of a light on the surface of the mixed resin layer is 80% or more and a diffusion reflectivity is 75% or more. The light reflector is provided as a product of the resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molded article and a light reflector, and more particularly, to a resin molded article and a light reflector which are excellent in flame retardancy and workability, and which are not separated from the crack even if they are bent. And a resin molded body having excellent light reflectivity and a light reflector composed of the resin molded body,
The present invention relates to a light reflector suitable as a light reflecting member used for an electric signboard, a medical or general photo observation device (light box for photo observation), and a lighting device such as a reflection sheath or a reflection surface.

[0002]

2. Description of the Related Art FIG. 1 shows an example of the structure of a general internally illuminated display device. FIG. 1 shows four fluorescent lamps 3 as light sources installed inside a box body 1 having a side wall 4 and a bottom wall 5 made of white painted steel plate having a function as a light reflecting plate, and the opening is made of milky white acrylic. 1 is a schematic view of an internally illuminated display device (medical X-ray photograph observation apparatus) having a structure covered with a display plate 2 made of resin.
FIG. 1 shows a state in which the display plate 2 has been removed and slid obliquely downward to the right in order to explain the internal structure of the box 1. In this type of internally illuminated display device, a fluorescent lamp 3 as a light source is used.
And the light reaching the side wall 4 and the bottom wall 5 from the fluorescent lamp directly, and the light reaching the side wall 4 and the bottom wall 5 (mainly the bottom wall 5) and finally reaching the display panel 2, causing the entire display panel 2 to be illuminated. It is brightly lit. Therefore, in order to make the display on the display panel and the photograph on the display panel easy to see, the illuminance on the display panel is as large as possible in the internally illuminated display device having such a structure.
It is desirable that the illuminance on the display panel is as uniform as possible. However, when the reflectance of the light reflector is low, the output of the light source must be increased in order to obtain sufficient illuminance on the display panel, so that the illuminance on the display panel is extremely low depending on the location. It becomes even,
There has been a problem that the shape of the light source is prominently prominent through the display panel, thereby reducing the commercial value. This problem can be improved to some extent by increasing the distance between the light source and the display board. However, to solve this problem, it is unavoidable to increase the size of the display device and increase the output of the light source. As described above, since high reflectivity is required for the light reflection plate, various materials as described below have been conventionally used. For example,
2. Description of the Related Art There is known a light reflection plate in which an aluminum vapor-deposited film is laminated on a surface of a base material such as metal to form a mirror surface on the surface. However, since the diffuse reflection is unlikely to occur in the light reflecting plate having the mirror surface, the illuminance on the display plate becomes too uneven, and the shape of the light source prominently emerges through the display plate. In addition, a metal material (white steel plate or the like) painted white is often used as a reflection plate. However, since the light reflecting plate made of a white painted steel plate and the light reflecting plate having a mirror surface formed on the surface are both made of metal, they are heavy and have poor workability such as cutting. On the other hand, WO97 / 01117 proposes a light reflection plate made of a thermoplastic polyester foam containing fine cells. Such a thermoplastic polyester foam is lightweight and has excellent total reflectance and diffuse reflectance, so that it exhibits excellent light reflection performance in an electric signboard or the like. But,
In order to obtain a light reflector having excellent total reflectance and diffuse reflectance, it is necessary to form ultra-fine bubbles in a thermoplastic polyester foam. The carbon dioxide gas is impregnated in the sheet by holding it in carbon dioxide gas for a long time, and before the carbon dioxide gas escapes from the sheet, it is heated and foamed before it can be produced without a very complicated manufacturing process. There is a problem.

The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, surprisingly, aromatic polycarbonate boats which are extremely poor in light reflectivity (in particular, excellent in light transmittance). Using a resin and mixing it with other synthetic resin components such as an olefin resin or an acrylic resin (and, in some cases, a white pigment), the mixed resin obtains the total reflectance and diffuse reflectance for light. Excellent, processability, productivity,
It was also found that the tear resistance during cutting was excellent. However, since the mixed resin contains other synthetic resin components such as an olefin resin and an acrylic resin, when the mixed resin is bent as compared with the aromatic polycarbonate resin alone to cause a crack or a crack. It has been found that it is easier to separate from the cracks and crevices. Further, since the mixed resin contains other synthetic resin components such as an olefin-based resin and an acrylic-based resin, the flame retardancy is lower than that of the aromatic polycarbonate resin alone. For this reason, it has been found that when a large amount of a flame retardant is added, the mixed resin is more likely to be separated from the bent portion when the mixed resin is bent, thereby being easily separated.

[0004]

SUMMARY OF THE INVENTION A first object of the present invention is to provide a resin having excellent productivity and light reflection performance, and having a property of hardly separating from a crack or a crack at a bent portion (hereinafter referred to as "break resistance"). It is to provide a molded article. In addition, the second object of the present invention is excellent in productivity and rupture resistance,
An object of the present invention is to provide a light reflector that can contribute to reducing power consumption when used for an illuminated signboard or the like. further,
A third object of the present invention is to provide a resin molded product or a light reflector excellent in productivity, rupture resistance, flame retardancy and light reflection performance.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, the inventors have found that, with respect to light containing an aromatic polycarbonate resin and other components,
A resin molded product obtained by laminating a back surface layer made of a synthetic resin or a synthetic resin composition having an Izod impact value of at least 5 kJ / m ² on the back surface of a mixed resin layer having excellent total reflectance and diffuse reflectance is productivity. The present inventors have found that they have excellent rupture resistance, and have completed the present invention. That is, according to the present invention, 30 to 75% by weight of an aromatic polycarbonate resin (A), 5 to 45% by weight of a thermoplastic resin and / or a thermoplastic elastomer (B) other than the aromatic polycarbonate resin, and a flame retardant (C) 0 to 60% by weight and a white colorant (D) 0 to 20% by weight ((A) +
(B) + (C) + (D) = 100% by weight) A back surface layer made of a synthetic resin or a synthetic resin composition having an Izod impact value of at least 5 kJ / m ² is integrally bonded to the back surface of the mixed resin layer. A resin molded product having a multilayer structure comprising: a resin having a total reflectance of 80% or more and a diffuse reflectance of 75% or more, which are parameters representing light reflection on the surface of the mixed resin layer. A body (resin molded body (1)) is provided. Further, according to the present invention, there is provided (resin molded body (2)) in which, in the resin molded body (1), a mixed resin layer is further bonded and integrated with the other surface of the back surface layer. Further, according to the present invention, in the resin molded article (1) or (2), the component (B) contains at least one selected from an olefin resin and an acrylic resin. A molded article (resin molded article (3)) is provided. Furthermore, according to the present invention,
In the resin molded article (3), a resin molded article (resin molded article (4)) in which the olefin resin is a polyethylene resin is provided. Furthermore, according to the present invention, in any one of the resin molded products (1) to (4), the back surface layer is selected from the group consisting of an aromatic polycarbonate resin, a thermoplastic polyester resin, and an olefin resin. 1
The resin molded article (resin molded article (5)) according to any one of claims 1 to 4, which is a synthetic resin layer or a synthetic resin composition layer containing two or more resins as main components. Furthermore, according to the present invention, the resin molded article is made of any one of the resin molded articles (1) to (5), and the total reflectance, which is a parameter representing light reflection on the surface of the mixed resin layer, is A light reflector characterized by having 93% or more and diffuse reflectance of 90% or more is provided.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The aromatic polycarbonate resin used for the aromatic polycarbonate resin (A) which is a component of the mixed resin layer having excellent light reflectivity located on the surface of the resin molded product of the present invention includes (i) A carbonyl halide component such as phosgene or a carbonate component such as diphenyl carbonate; and (ii) a diol component comprising at least 50 mol% of an aromatic diol component or an aromatic diol component such as a bisphenol compound and at least 50 mol% of another diol component. From polycarbonate resins. In particular, an aromatic polycarbonate resin having diphenylalkane in a molecular chain, and ASTM D-6
1820 kPa (18.6 kgf / cm
² ) An aromatic polycarbonate resin having a heat distortion temperature of 120 ° C. or higher, preferably 125 ° C. or higher, more preferably 130 to 170 ° C., measured under the condition of load,
In addition to excellent flame retardancy, heat resistance, cutting workability and impact resistance,
It is suitable because it has excellent weather resistance and acid resistance. Such aromatic polycarbonate resins having diphenylalkane in the molecular chain include 2,2-bis (4-oxyphenyl) propane (also known as bisphenol A), 2,2
-Bis (4-oxyphenyl) butane, 1,1-bis (4-oxyphenyl) cyclohexane, 1,1-bis (4-oxyphenyl) isobutane, 1,1-bis (4-oxyphenyl) ethane, etc. Aromatic polycarbonate resins formed from the bisphenol-based compounds are exemplified.

The aromatic polycarbonate resin (A) (hereinafter sometimes abbreviated as “resin (A)”) is usually excellent in transparency and transmits most of the light. And inferior diffuse reflectance. Therefore, the resin (A) alone cannot provide a resin molded article excellent in total reflectance and diffuse reflectance for visible light. Therefore,
In order to provide the total reflectance and the diffuse reflectance with respect to visible light, a thermoplastic resin other than the resin (A) and / or a thermoplastic elastomer (B) (hereinafter referred to as component (B))
May be omitted). Component (B)
Is used as the thermoplastic resin and / or the thermoplastic elastomer other than the resin (A). In the present invention, the aromatic polycarbonate resin (A) is used to increase the total reflectance and the diffuse reflectance with respect to visible light. A) a thermoplastic resin or / and a thermoplastic elastomer having a refractive index of 0.03 or more or a refractive index of 0.03 or more (the refractive index is a measured value based on the method described in JIS K 7105). Is preferably used as the component (B). Incidentally, the refractive index of a typical bisphenol A polycarbonate resin is about 1.59.

As the above-mentioned component (B), a substance selected from acrylic resins and olefin resins is preferably used alone or in the form of a mixture of two or more kinds. Is preferable because the effect of increasing the total reflectance and the diffuse reflectance of the resin (A) with respect to visible light is excellent. In addition, the fact that a small amount of addition is enough
This means that the total reflectance and the diffuse reflectance can be increased without lowering the excellent heat resistance, impact resistance, or flame retardancy of the resin (A) as much as possible, and is a preferable embodiment in the present invention.

The acrylic resin has an acrylic group represented by the following general formula (1): CH ₂ ＣC (R)-(1) (wherein R represents a lower alkyl group having 1 to 4 carbon atoms). And a polymer compound formed by polymerizing or copolymerizing the unsaturated compound. In this case, the acrylic unsaturated compound includes acrylic acid and its ester, acrylamide, acrylonitrile, methacrylic acid and its ester, and the like, and the acrylic resin includes a polymer or copolymer of the acrylic unsaturated compound. Coalescing is included. As typical acrylic resins, polymethyl methacrylate resin and polymethyl acrylate resin are exemplified. Particularly, by using a polymethacrylic acid ester resin such as a polymethyl methacrylate resin as the component (B), the tear strength of the resin molded article and the light reflector containing the other components in the aromatic polycarbonate resin is effectively reduced. Can be deterred. Since this has a high tear strength, it also has an excellent effect of preventing a decrease in rupture resistance. Further, when an acrylic resin is used as the component (B), there is an effect that the amount of an expensive white colorant described later can be reduced or the amount used can be reduced to zero.

The olefin resin comprises a polymer and a copolymer containing olefins such as ethylene, propylene and butene as main components. As the olefin resin,
Polyethylene, ethylene-butene-1 random copolymer, ethylene-octene-1 random copolymer, ethylene-pentene-1 random copolymer, polypropylene, propylene-ethylene random copolymer, propylene-ethylene block copolymer, Examples thereof include a propylene-butene-1 random copolymer, a propylene-ethylene-butene-1 random copolymer, and polybutene. The olefin resin is preferably used in combination with a white colorant. In this case, in particular, a polyethylene resin (polyethylene or an ethylene copolymer having an ethylene component ratio of 50% by weight or more) is used as the component (B). By doing so, it is possible to reduce the use amount of an expensive white colorant described later or to reduce the use amount to zero.

As the flame retardant (C) which can be one component of the mixed resin layer having excellent light reflectivity located on the surface of the resin molded article of the present invention, carbonates of decabromodiphenyl ether, tetrabromobisphenol A and tetrabromobisphenol A Oligomers, alkali metal or alkaline earth metal salts of perfluoroalkanesulfonic acid,
Examples thereof include triphenyl phosphate, tri (2,4,6-tribromophenyl) phosphate, alkali metal salts or alkaline earth metal salts of diphenylsulfonic acid, and organopolysiloxane having an organosilyl group.
In any case, a white color is preferable, and a color that is not colored during melt processing for forming the mixed resin layer is preferable.

A flame-retardant synergist which can enhance the flame-retardant effect when used in combination with a flame-retardant is further mixed into the mixed resin layer having excellent light reflectivity located on the surface of the resin molded article of the present invention. Is preferred. By doing so, the addition amount of the flame retardant and the flame retardant synergist can be reduced. Such flame retardant synergists include antimony trioxide, organosiloxane, zirconium oxide, magnesium hydroxide, aluminum hydroxide,
Examples thereof include calcium carbonate and organopolysiloxane having an organosilyl group. In any case, a white color is preferable, and a color that is not colored during melt processing for forming the mixed resin layer is preferable.

The flame retardancy of the mixed resin layer having excellent light reflectivity located on the surface of the resin molded article of the present invention is reduced by the presence of the component (B). Therefore, when high flame retardancy is required for the mixed resin layer, and thus the resin molded body and the light reflector, the flame retardant (C) or the flame retardant (C) and the flame retardant synergist are contained in the mixed resin layer. It is preferable to keep it.

In the mixed resin layer having excellent light reflectivity located on the surface of the resin molding of the present invention, a white colorant (D) can be mixed and present. White colorant (D)
Works to increase the total reflectance and the diffuse reflectance on the surface of the mixed resin layer, but it is usually expensive, so use of a large amount is not preferable. Examples of the white colorant (D) include pigments made of inorganic compounds having a white color such as titanium dioxide, calcium carbonate, and silica. In particular, titanium dioxide is added to a mixed resin layer with a high total reflectance and diffuse reflection by adding a small amount. It is preferable because the rate can be given. The use of the white colorant (D) can be omitted depending on the selection of the component (B), but it is usually preferable to add a small amount to the mixed resin layer. The white colorant (D) and an acrylic resin and / or an olefin resin (component (B))
Is a preferred embodiment in the present invention, because the addition effect of each is simultaneously exhibited.

The mixed resin layer located on the surface of the resin molded article of the present invention comprises 30 to 75% by weight of the resin (A), 5 to 45% by weight of the component (B), and 0 to 60% by weight of a flame retardant ( C) and 0 to 20% by weight of a white colorant (D),
And a component obtained by melt-kneading at a temperature equal to or higher than the melting temperature of the component (B). At this time, as the compounding ratio of the resin (A) decreases, the excellent properties of the resin (A) such as excellent heat resistance, impact resistance, and flame retardancy are greatly reduced.
The higher the ratio, the more difficult it is to obtain a high total reflectance and a high diffuse reflectance. Therefore, the mixing ratio of the resin (A) is (A) +
When (B) + (C) + (D) = 100% by weight,
30 to 75% by weight.

As the proportion of the component (B) decreases, it becomes difficult to obtain a high total reflectance and a high diffuse reflectance, and the proportion of the expensive white colorant must be increased.
Conversely, as the blending ratio of the component (B) increases, the excellent properties of the resin (A) such as excellent heat resistance, impact resistance, and flame retardancy are greatly reduced. A)
When + (B) + (C) + (D) = 100% by weight, the content is 5 to 45% by weight. However, it is desirable that the compounding amount of the component (B) is 50% by weight or less, preferably 45% by weight or less when the resin (A) + the component (B) = 100% by weight. Then, the mixed resin layer can inherit many of the features of the resin (A).

As the proportion of the flame retardant (C) in the mixed resin layer decreases, the mixed resin layer becomes more flammable. Conversely, as the proportion of the flame retardant (C) increases, the mixed resin layer becomes brittle. Flame retardant (C)
Is (A) + (B) + (C) + (D) = 10
When it is 0% by weight, it may be 0% by weight. However, when it is necessary to make the mixed resin layer, that is, the resin molded body and the light reflector difficult to burn, the content is 5 to 60% by weight.
0% by weight is more preferred. When the flame retardant synergist is used in combination with the flame retardant, the flame retardant synergist is treated as a component of the flame retardant (C).

The white colorant (D) imparts a high total reflectance and a high diffuse reflectance to the surface of the mixed resin layer even if the white colorant (D) is not mixed in the mixed resin layer depending on the type and the amount of the component (B). It is possible. Therefore, the blending of the white colorant (D) can be omitted. However, the combined use of the white colorant (D) and the component (B) simultaneously exerts the respective compounding effects,
As a result, the compounding amount of both components is reduced, and the mixed resin layer is preferable because many of the features of the resin (A) can be inherited. However, if a large amount of the white colorant (D) is mixed in the mixed resin layer, the white colorant (D) is not uniformly mixed. As a result, the light reflection performance on the mixed resin layer surface becomes uneven or the production cost is increased. . Therefore,
The mixing ratio of the white colorant (D) is (A) + (B) +
When (C) + (D) = 100% by weight, 0 to 20
%, Preferably 2 to 13% by weight.

In the mixed resin layer, (A) + (B) +
When (C) + (D) = 100 parts by weight, (A),
Components other than (B), (C) and (D) can be contained up to 15 parts by weight, preferably up to 10 parts by weight, more preferably up to 5 parts by weight. It is preferable that the blending of the other components be kept to the minimum necessary. Examples of the other components include resin additives such as an ultraviolet absorber, an antioxidant, an antistatic agent, a fluorescent brightener, and a lubricant.

The resin molded article of the present invention is obtained by integrally bonding a back layer made of a synthetic resin or a synthetic resin composition having an Izod impact value of at least 5 kJ / m ² to the back surface of the mixed resin layer. . This back layer compensates for the brittleness of the mixed resin layer, and as a result, causes the resin molded article of the present invention to crack and be difficult to separate when bent. When the back surface layer is made of a synthetic resin or a synthetic resin composition having an Izod impact value of less than 5 kJ / m ² , the resin molded body is easily broken and separated when bent. In order to make the resin molded body cracked when bent and difficult to separate, the backside layer has an Izod impact value of at least 7 k.
J / m ² of a synthetic resin or a synthetic resin composition having an Izod impact value of at least 9 kJ.
/ M ² of a synthetic resin or a synthetic resin composition having an Izod impact value of at least 10
More preferably, it is made of a synthetic resin or a synthetic resin composition having a kJ / m ² .

Izod impact value of at least 5 kJ / m
^The synthetic resin or the synthetic resin composition which is No. 2 contains one or two or more resins selected from aromatic polycarbonate resins, thermoplastic polyester resins and olefin-based resins as main components (“main component”). Means that the content is 50% by weight or more in the synthetic resin composition). The synthetic resin or the synthetic resin composition is exemplified as a preferable embodiment. Particularly, among these, those containing an aromatic polycarbonate resin as a main component are most preferable because they can be directly thermally bonded to the mixed resin layer. Examples of the aromatic polycarbonate resin used herein include (i) a carbonyl halide component such as phosgene or a carbonate component such as diphenyl carbonate, and (ii) an aromatic diol component such as a bisphenol compound or an aromatic diol component 50 mol%. A polycarbonate resin formed from the above and a diol component comprising 50 mol% or more of another diol component is exemplified. In particular, an aromatic polycarbonate resin having diphenylalkane in a molecular chain, and ASTM D
1820 kPa (18.6 kgf /
cm ² ) The heat distortion temperature measured under the load condition is 120 ° C.
Above, preferably 125 ° C. or higher, more preferably 130 to 170 ° C., aromatic polycarbonate resin is excellent in flame retardancy, heat resistance, cutting workability and rupture resistance, and is excellent in weather resistance and acid resistance. It is preferable because of its superiority.
Examples of such aromatic polycarbonate resins having diphenylalkane in the molecular chain include 2,2-bis (4-oxyphenyl) propane (also known as bisphenol A),
2,2-bis (4-oxyphenyl) butane, 1,1-
Bis (4-oxyphenyl) cyclohexane, 1,1-
Bis (4-oxyphenyl) isobutane or 1,1
Aromatic polycarbonate resins formed from bisphenol compounds such as -bis (4-oxyphenyl) ethane are exemplified.

The backside layer compensates for the brittleness of the mixed resin layer, and as a result, causes the resin molded article of the present invention to crack and be difficult to separate when bent. In contrast, an increase in the thickness more than necessary leads to an increase in the cost of the resin molded body.
The thickness is preferably 00 μm, more preferably 10 to 1000 μm, and even more preferably 50 to 500 μm.

The Izod impact value of the synthetic resin or the synthetic resin composition forming the back layer is determined by sufficiently drying the synthetic resin or the synthetic resin composition used for the back layer (water content is 0.005% by weight). Then, the mixture was heated and compressed for 3 minutes at a temperature of 250 ° C. and a pressure of 9.8 MPa.
By moving the film between cooling presses at a temperature of 0 ° C. and sufficiently cooling it, a resin plate made of a synthetic resin or a synthetic resin composition having a thickness of 4 mm is prepared, and JIS K711 is prepared from the resin plate.
This is a value measured according to JIS K 7110-1984 using a No. 1 A test piece specified in 0-1984 and using the test piece. The details of the test conditions are as follows. Hammer weight: 784 g. Distance from center line of rotation axis of hammer to center of gravity ・ ・ ・ 6.8
5 cm. Distance from the center axis of the hammer rotation axis to the edge of the impact blade
・ 30.7cm. Capacity: 0.98J. Hammer lifting angle: 150 °. Hammer impact speed: 3.35 m / sec. Impact direction: Edge-wise impact. Number of test pieces: 5 pieces. As the Izod impact value in the present invention, an arithmetic mean value based on the measured values of these five test pieces is adopted. If the test piece is not broken under the above measurement conditions,
In the present invention, the Izod impact value is at least 31k.
It is considered to be J / m ² .

The mixed resin layer forming one surface of the resin molded article of the present invention has a total reflectance of 80% or more, which is a parameter representing the reflectance of light measured on the surface of the mixed resin layer, and a diffuse reflectance. Is 75% or more. 80% total reflectance
The above and the requirement that the diffuse reflectance is 75% or more are used on display surfaces of internally illuminated display devices such as illuminated signboards, medical X-ray photographing observation devices, and the like, or when the reflection of lighting devices is used for pods and reflections. In some cases, it is indispensable to reduce the difference between high illuminance and illuminance depending on the location under illumination. Even when the total reflectance is less than 80% or the diffuse reflectance is less than 75%, it is difficult to reduce the difference between the high illuminance and the illuminance depending on the location. Among the resin molded products, those having a total reflectance of 93% or more and a diffuse reflectance of 90% or more are particularly excellent in light reflectivity and diffuse reflectivity. If it is used as a light reflector for reflecting light toward the display unit by placing it in the
If the number of electroluminescent elements such as fluorescent lamps and light bulbs is not reduced, the output of those luminous elements can be reduced. Conversely, if the output of the electroluminescent elements is not reduced, the number of luminescent elements can be reduced. It is preferable because it can minimize the amount of electricity used and contribute to the suppression of global warming. If the thickness of the mixed resin layer is small, it may be difficult to obtain a high total reflectance and a high diffuse reflectance, while if the thickness is too large, the cost increases excessively. It is preferably from 1 to 20 mm, more preferably from 0.2 to 7 mm, 0.3
３3 mm is more preferable, and 0.4-1 mm is most preferable.

The total reflectance, which is a parameter representing the light reflectance measured on the surface of the mixed resin layer, is 80% or more (preferably 93% or more) and the diffuse reflectance is 75% or more (preferably 90% or more). The requirement is achieved by melt-kneading the resin (A) and the component (B) in the mixed resin layer, or by melt-kneading the resin (A), the component (B), and the white colorant (D). Therefore, the mixed resin layer is formed by adding the resin (A), the component (B), the flame retardant (C), the white colorant (D), and the other components as required, and using an extruder or the like. And then melt-knead it into a desired shape such as a film shape, sheet shape, plate shape, or reflection shape of a lighting fixture or a reflection rough shape using means such as extrusion molding or injection molding. Obtainable. When the back surface layer and the mixed resin layer have thermal adhesiveness, it is preferable to employ a co-extrusion method or the like because the mixed resin layer and the surface layer can be directly bonded without an additional adhesive layer. Among the resin molded products having a multi-layered structure of the mixed resin layer and the back surface layer, the sheet-shaped resin molded products should be processed by thermoforming into resin molded products of different shapes such as the reflection shape of the lighting fixture and the reflection rough shape. Can be.

In the above-described resin molded article of the present invention, the mixed resin layer is provided on one surface and the back surface layer is bonded and integrated on the opposite surface. The resin layer may be bonded and integrated in this order. In particular, when high light reflection performance is required on both surfaces of the resin molded body, an embodiment in which a mixed resin layer is formed on both surfaces is used.

[0027]

Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 51.1 parts by weight of an aromatic polycarbonate resin (trade name: Iupilon H3000 (refractive index: 1.59)) manufactured by Mitsubishi Engineering-Plastics Co., Ltd. as resin (A) and Idemitsu Petroleum as component (B) High-density polyethylene resin manufactured by Chemical Co., Ltd. [Product name: IDEMITSU HD
520 MB (refractive index: 1.54)] 15.8 parts by weight, tetrabromobisphenol A-based flame retardant (trade name: FG-8500) 1 manufactured by Teijin Chemicals Limited as a flame retardant (C)
2.3 parts by weight, 6.2 parts by weight of antimony trioxide as a flame retardant synergist, and titanium dioxide masterbatch manufactured by Polycor Kogyo Co., Ltd. as a component (B) + white colorant (D) [Product name: RE-120] -80K (titanium dioxide masterbatch consisting of 80% by weight of titanium oxide and 20% by weight of polyethylene wax)] 7.2 parts by weight, component (B)
+ Antistatic agent manufactured by Kao Corporation as other components [trade name: HE-510 (antistatic masterbatch composed of 90% by weight of high-density polyethylene and 10% by weight of antistatic agent)] (high-density polyethylene in this) Is the component (B)
8.2 parts by weight, and a fluorescent whitening agent (trade name: Ubitex OB) manufactured by Ciba Geigy Corporation as another component.
08 parts by weight was fed into a first extruder (a twin-screw extruder) to form a mixed resin layer, and a first melt-kneaded product was produced in the first extruder. At the same time, an aromatic polycarbonate resin having a refractive index of 1.59 [trade name: Iupilon H3000 (Izod impact value is at least 31 kJ / m ² )] manufactured by Mitsubishi Engineering-Plastics Co., Ltd. (A single screw extruder), and a second melt-kneaded product was produced in the second extruder. Subsequently, the first melt-kneaded material / the second melt-kneaded material / the first melt-kneaded material are merged in this order between the T-die and the extruder, and after the merged material is extruded from the T-die, Sheeting, cutting with a cutting machine, thickness 0.6m
m of a sheet-shaped resin molded product was obtained. The thickness of each layer in the obtained resin molded body having a three-layer structure is the mixed resin layer 250
μm / backside layer 100 μm / mixed resin layer 250 μm.

Example 2 [Example in which the amounts of the flame retardant and the flame retardant synergist were reduced in Example 1] As the resin (A), an aromatic polycarbonate resin manufactured by Mitsubishi Engineering-Plastics Corporation [trade name: Iupilon H3000 ( Refractive index: 1.59)] 54.4 parts by weight, high-density polyethylene resin manufactured by Idemitsu Petrochemical Co., Ltd. [trade name: IDEMITSU HD as component (B)]
520 MB (refractive index: 1.54)] 16.9 parts by weight, tetrabromobisphenol A-based flame retardant (trade name: FG-8500) manufactured by Teijin Chemicals Limited as flame retardant (C)
8 parts by weight and antimony trioxide 4.4 as a flame retardant synergist
Parts by weight, component (B) + titanium dioxide masterbatch [product name: RE-120-80K (composed of 80% by weight of titanium oxide and 20% by weight of polyethylene wax) as a white colorant (D)] 7.6 parts by weight, component (B) + an antistatic agent manufactured by Kao Corporation [trade name: HE]
-510 (Antistatic agent masterbatch composed of 90% by weight of high-density polyethylene and 10% by weight of antistatic agent)] (8.8 parts by weight of high-density polyethylene being component (B)) and Ciba-Geigy as other components 0.09 parts by weight of a fluorescent whitening agent manufactured by Co., Ltd. (trade name: Ubitex OB) is charged into a first extruder (a twin screw extruder) to form a mixed resin layer, and the first extrusion is performed. A first melt-kneaded product was produced in the machine. At the same time, in order to form the back surface layer, an aromatic polycarbonate resin having a refractive index of 1.59 [trade name: Iupilon H3000 (Izod impact value of at least 3) manufactured by Mitsubishi Engineering-Plastics Corporation]
1 kJ / m ² )] into a second extruder (single screw extruder) to produce a second melt-kneaded material in the second extruder. Subsequently, the first melt-kneaded product /
The second melt-kneaded material / the first melt-kneaded material are merged in this order,
The extruded product was extruded from a T-die, sheeted, and cut by a cutter to obtain a sheet-shaped resin molded product having a thickness of 0.6 mm. The thickness of each layer in the obtained resin molded article having a three-layer structure was 250 μm of the mixed resin layer / 100 μm of the back surface layer / 250 μm of the mixed resin layer.

Example 3 [Example in which the addition of a flame retardant and a flame retardant synergist in Example 1 was changed to 0] As the resin (A), an aromatic polycarbonate resin manufactured by Mitsubishi Engineering-Plastics Corporation [trade name: Iupilon H3000] (Refractive index: 1.59)] 62.7 parts by weight, high-density polyethylene resin manufactured by Idemitsu Petrochemical Co., Ltd. as component (B) [trade name: IDEMITSU HD]
520 MB (refractive index 1.54)] 15.8 parts by weight, titanium dioxide masterbatch (product name: RE-) manufactured by Polycor Kogyo Co., Ltd. as component (B) + white colorant (D)
120-80K (titanium dioxide masterbatch consisting of 80% by weight of titanium oxide and 20% by weight of polyethylene wax)] 8.8 parts by weight, component (B) + antistatic agent manufactured by Kao Corporation as other component [trade name : HE-510 (Antistatic agent masterbatch composed of 90% by weight of high-density polyethylene and 10% by weight of antistatic agent)] (wherein high-density polyethylene is component (B)) 10.1 parts by weight, and other components And 0.1 parts by weight of a fluorescent whitening agent (trade name: Ubitex OB) manufactured by Ciba-Geigy Co., Ltd. into a first extruder (a twin-screw extruder) to form a mixed resin layer. The first melt-kneaded product was produced in the extruder. At the same time, in order to form the back surface layer, an aromatic polycarbonate resin having a refractive index of 1.59 [trade name: Iupilon H30, manufactured by Mitsubishi Engineering-Plastics Corporation]
00 (Izod impact value is at least 31 kJ /
m ² )] into a second extruder (single screw extruder)
A second melt-kneaded product was produced in the extruder of No. 1. Then, T
The first melt-kneaded material / the second melt-kneaded material / the first melt-kneaded material are merged in this order between the die and the extruder, and after the merged material is extruded from the T-die, sheeting is performed.
The sheet was cut by a cutting machine to obtain a sheet-shaped resin molded body having a thickness of 0.6 mm. The thickness of each layer in the obtained resin molded product having a three-layer structure is 250 μm of the mixed resin layer / 100 of the back surface layer.
μm / 250 μm of the mixed resin layer.

Example 4 [mixed resin layer in Example 1 /
Example in which the three-layer structure of the back layer / mixed resin layer is changed to the two-layer structure of the mixed resin layer / back layer] Example 1 is repeated to produce the first melt-kneaded product in the first extruder and the second A second melt-kneaded product was produced in the extruder of No. 1. Subsequently, the first die is extruded between the T-die and the extruder.
And the second melt-kneaded material is joined in this order, and the combined material is extruded from a T-die, sheeted, cut by a cutting machine, and formed into a sheet-like resin sheet having a thickness of 0.6 mm. I got a body. The thickness of each layer in the obtained resin molded body having a two-layer structure is 500 μm of the mixed resin layer / the back layer 1
It was 00 μm.

Comparative Example 1 [single layer without flame retardant] In Example 1, the same operation as in Example 1 was repeated without adding the flame retardant and the flame retardant auxiliary and without laminating the back layer. Thus, a sheet-shaped resin molded product consisting only of the mixed resin layer having a thickness of 0.6 mm was obtained.

Comparative Example 2 [Modification of Backside Layer] In Example 1, the same operation as in Example 1 was repeated without adding a flame retardant and a flame retardant auxiliary, and without laminating the backside layer. A sheet consisting of only the mixed resin layer having a thickness of 0.5 mm was obtained. Subsequently, styrene-
Maleic anhydride copolymer (Izod impact value 3.1 kJ
/ M ² ), and a sheet having a thickness of 0.1 mm was laminated with a urethane-based adhesive to produce a resin molded body composed of a laminated sheet.

Comparative Example 3 [Single Layer with Flame Retardant] In Example 1, the same operation as in Example 1 was repeated without laminating the back surface layer to obtain a 0.5 mm thick sheet composed of only the mixed resin layer. After extruding from a T-die for extrusion molding, sheeting was attempted, but the sheet was torn in several directions in the extrusion direction and could not be formed into a sheet.

(1) Measurement of Physical Properties The total reflectance, diffuse reflectance and whiteness of the resin molded products obtained in Examples 1 to 4 and Comparative Examples 1 and 2 on the mixed resin layer side surface were measured. Further, the resin molded body is placed on the bottom of a medical X-ray photograph observation apparatus described later and used as a light reflector on the bottom, and the average illuminance and the illuminance on the display plate surface in a state where the internal fluorescent lamp is turned on. The difference (R value) between the maximum value and the minimum value was measured by the method described later. Further, a bending test described later was performed on the resin molded body. Further, a combustion test was performed on the resin molded body. Table 1 shows the measurement results.

(2) Measuring method (i) The total reflectance and the diffuse reflectance of the resin molded product are:
550n with Shimadzu Corporation's self-recording spectrophotometer, brand name "Shimadzu self-spectrophotometer UV-2200" attached to the company's integrating sphere accessory device, brand name "ISR-2200"
It was measured at a wavelength of m. The total reflectance was measured at an incident angle of 8 degrees, and the diffuse reflectance was measured at an incident angle of 0 degrees. These measured values are expressed as relative values when the total reflectance and the diffuse reflectance of a white plate in which barium sulfate fine powder is solidified are each set to 100%. Further, as the white plate, a barium sulfate fine powder reagent (Wako first grade, product number 022-0042) manufactured by Wako Pure Chemical Industries, Ltd. was used according to the method described in the instruction manual of “ISR-2200”.
5, lot number PAR 2142) is changed to "ISR-2
The powder sample holder attached to a predetermined portion of the powder sample holder attached to the sample 200 was compacted. (Ii) Whiteness was measured using a compact colorimeter of Color Techno System Co., Ltd., trade name "X-Rite 948". The numerical values of the whiteness in Table 1 were measured at five arbitrary points on the surface of the mixed resin layer of the resin molded product.
It is expressed by the arithmetic mean of the points. (Iii) The average illuminance and R value on the display panel surface were measured as follows. First, a medical X-ray photographing observation device manufactured by Kihara Medical Industry Co., Ltd.
211 (Desktop / Wall hanging type 15W 4 lamps 2 sheets 50H
z) ”is prepared. FIG. 1 shows an outline of the photograph observation apparatus. This is a box 1 having a side wall 4 and a bottom wall 5 made of white painted steel plate and having a size of 625 mm × 495 m × 110 mm.
A display panel 2 made of milky white acrylic resin having a size of 565 mm × 425 mm is attached to the
Indicates a state where the display plate 2 is removed and slid for the internal explanation. At the time of measurement, the display plate 2 is attached to a predetermined portion of the box 1). Next, the resin molded body was fixed on the entire bottom surface of the inside of the box with double-sided tape, laid flat, and four fluorescent lamps 3 were turned on.
Product name “Pocket illuminometer ANA-F9 LUX MET”
The illuminance at 35 points on the display board is measured using "ER". The measurement points are a total of 35 points: 20 points right above the fluorescent lamp and 15 points on the intermediate point of each adjacent fluorescent lamp. The point directly above the fluorescent lamp is a point at the center of each fluorescent lamp in the longitudinal direction (1 point × 4), an intermediate point between the center and both ends of the fluorescent lamp (2 points × 4), and It is a point located at the center between the intermediate point and both ends of the fluorescent lamp (2 points × 4). The intermediate point between the adjacent fluorescent lamps is the respective intermediate point when the measurement points on the fluorescent lamp are connected between the adjacent fluorescent lamps by a straight line orthogonal to the longitudinal direction of the fluorescent lamp. The R value is the difference between the maximum value and the minimum value among the 35 measurement points. (Iv) The bending test for the resin molded product was performed by a sample having a length of 10 cm along the extrusion direction and a width of 3 cm along the width direction from the sheet-shaped resin molded product, and a width of 3 cm along the extrusion direction and a width direction. A sample of 10 cm in length (with the same thickness) is cut out along the line, and when each cut sample is bent at 90 degrees for 1 second from the center in the length direction, whether or not each sample is broken and separated. Was observed. Table 1 shows the results. If no sample was separated, "No separation" is displayed,
When any of the samples was separated, "Separation" is indicated in Table 1. In addition, when the cut sample does not separate even if a crack or a crack occurs in the mixed resin layer, it is evaluated as “not separated”. (V) In the combustion test for the resin molded product, a sheet having a length of 150 mm and a width of 6.5 mm (with the same thickness) was cut out from the sheet-shaped resin molded product, and the test piece was supported in accordance with JIS K 7201 (the supporting method of the test piece was A-1). No.) "Test method for combustion of polymer materials by oxygen index method" was carried out. Table 1 shows the oxygen index of each example measured from this test. (Vi) The Izod impact value of an aromatic polycarbonate resin (all examples) or a styrene-maleic anhydride copolymer (Comparative Example 2) constituting the back surface layer was measured using an Izod impact tester (manufactured by Toyo Seiki Seisaku-sho, Ltd.) No. 121903304) under the above conditions.

[0037]

[Table 1]

[0038]

The resin molded product of the present invention comprises 30 to 75% by weight of an aromatic polycarbonate resin (A), 5 to 45% by weight of a thermoplastic resin or / and a thermoplastic elastomer (B) other than the aromatic polycarbonate resin, Flame retardant (C) 0-6
0% by weight, and 0 to 20% by weight of a white colorant (D) ((A) + (B) + (C) + (D) = 10).
0% by weight) A resin molded product having a multilayer structure in which a back surface layer made of a synthetic resin or a synthetic resin composition having an Izod impact value of at least 5 kJ / m ² is integrally bonded to the back surface of the mixed resin layer, Since the total reflectivity, which is a parameter representing light reflection on the surface of the mixed resin layer, is 80% or more and the diffuse reflectivity is 75% or more, productivity and light reflection performance are excellent. Such a resin molded body is, for example, a light reflecting portion for arranging in an illuminated signboard or an illuminated display device to reflect light toward the display portion, or a reflection used as a lighting device, such as a light reflecting member. It can be suitably used as such. Further, this resin molded article is excellent in rupture resistance due to the presence of the back surface layer. Further, when the resin molded article of the present invention is in the form of a sheet, it can be easily formed into a desired shape by thermoforming, and is excellent in thermoforming workability.
The resin molded body of the present invention, in addition to the use as a light reflector,
It can also be suitably used for applications such as signboards, white boards, and road sign boards that are not illuminated. In particular, when the component (B) used in the present invention contains at least one selected from an acrylic resin and an olefin resin, the subcomponent (B) easily transmits light (poor in reflectivity). A) An aromatic polycarbonate resin (A) is a substance effective for imparting a high total reflectance and a diffuse reflectance to the aromatic polycarbonate resin (A), and a state in which a large amount of the aromatic polycarbonate resin (A) is left, that is, properties of the aromatic polycarbonate resin. Since the light reflection performance can be maintained at a high level without lowering (heat resistance, impact resistance, flame retardancy) as much as possible, the characteristics (heat resistance, impact resistance, flame retardancy) of the aromatic polycarbonate resin are reduced as much as possible. It is a molded article that can maintain the light reflection performance at a high level without causing the molding. In the present invention, a resin molded article having a mixed resin layer using a polyethylene resin as the component (B) as the olefin resin has an effect of minimizing the addition amount of an expensive white colorant such as titanium dioxide. The light reflector of the present invention is composed of the resin molded body, and has a total reflectance of 93% or more and a diffuse reflectance of 90% or more on the surface of the mixed resin layer, which are parameters representing light reflection. Since it is particularly excellent in light reflectivity and diffuse reflectivity, it is used, for example, as a light reflecting portion for arranging in an illuminated signboard or an illuminated display device to reflect light toward a display portion, or as a lighting device. In the case where the reflection is used for pods or the like, the output of the luminous bodies such as fluorescent lamps and electric bulbs can be reduced when the number of the luminous bodies is not reduced, or when the output of the luminous body is not reduced. Can reduce the number of light emitters. As a result, it is possible to minimize the amount of electricity used, which can contribute to the suppression of global warming. In addition, when this light reflector is used as a reflector for an electric signboard or the like, the effect of reducing the thickness of the signboard is achieved.
Therefore, it is possible to produce a space-saving signboard.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a medical X-ray photograph observation apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Box body 2 Display board 3 Fluorescent lamp 4 Wall part 5 Light reflection plate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 33/06 C08L 33/06 69/00 69/00 101/00 101/00 G02B 1/04 G02B 1 / 04 5/02 5/02 B (72) Inventor Takeshi Ken Aoki 2028-20 Tsuchizawa, Imaichi-shi, Tochigi Pref. ) 2H042 BA01 BA02 BA12 BA15 BA18 4F100 AK01A AK01B AK01D AK03C AK25C AK45A AL09A AL09B AL09D AT00C BA02 BA03 BA07 BA10A BA10C CA08B CA08D GB90 JB16A JB16B JB16D JK02 JN06 4J002 BB03X BB05X BB15X BB17X BG06X BG12X BP02X CG00W CP03Y DE137 DE237 DJ017 ED046 EJ056 EV256 FD097 FD136

Claims (6)

[Claims] 1. An aromatic polycarbonate resin (A) 30
To 75% by weight, thermoplastic resin and / or thermoplastic elastomer (B) other than aromatic polycarbonate resin
5% by weight, flame retardant (C) 0 to 60% by weight, and white colorant (D) 0 to 20% by weight ((A) +
(B) + (C) + (D) = 100% by weight) A back surface layer made of a synthetic resin or a synthetic resin composition having an Izod impact value of at least 5 kJ / m ² is integrally bonded to the back surface of the mixed resin layer. A resin molded product having a multilayer structure comprising: a total reflectance of 80% or more and a diffuse reflectance of 75% or more, which are parameters representing light reflection on the surface of the mixed resin layer; body. 2. The resin molded article according to claim 1, wherein a mixed resin layer is further bonded and integrated to the other surface of the back surface layer. 3. The resin molded article according to claim 1, wherein said component (B) contains at least one resin selected from olefin resins and acrylic resins. 4. The resin molded article according to claim 3, wherein the olefin resin is a polyethylene resin. 5. The back layer is a synthetic resin layer or a synthetic resin composition layer containing one or more resins selected from aromatic polycarbonate resin, thermoplastic polyester resin and olefin resin as a main component. The resin molded product according to any one of claims 1 to 4. 6. The resin molded product according to claim 1, wherein a total reflectance as a parameter representing light reflection on the surface of the mixed resin layer is 93% or more and a diffuse reflectance is 90%. A light reflector characterized by the above.