JPH10217412A - Matte polycarbonate resin laminate plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polycarbonate resin plate having a matte surface without defect in appearance due to heat transfer by improving weatherability. SOLUTION: The matte polycarbonate resin laminate plate having 80% or less of 60 degree mirror glossiness of a surface is obtained by a method having the steps of covering one or both surfaces of a base material layer polycarbonate resin with a coating layer polycarbonate resin mixed with 1 to 20wt.% of ultraviolet absorber and having a thickness of 1 to 200μm, and heat transferring a convexo-concave shape of a mold having a matte shape on the surface of the laminated resin plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a weather-resistant polycarbonate resin laminate having a matte surface, which is useful as a building material or the like.

[0002]

2. Description of the Related Art In the past, frosted glass was first mentioned as a frosted plate, and was widely used for store display showcases, partitions, bathroom door windows, window glasses, building materials and the like. However, in recent years, resinization has progressed for the purpose of weight reduction and crack prevention, and matte plates have been made from acrylic resin, polystyrene resin, and the like. Among these, the matte plate made of an acrylic resin has been widely used as a substitute for frosted glass regardless of indoors and outdoors, because of its excellent weather resistance and being capable of being arbitrarily colored.

[0003] There are two main methods for producing a matte plate made of acrylic resin. An acrylic resin in a heated and molten state is brought into close contact with a mold having a matte surface, cooled and solidified, and the uneven shape is transferred to the plate surface. And an internal matting method in which fine powders and fine particles such as mica, talc, and silicone beads are mixed with an acrylic resin, and the fine powders and fine particles are raised and raised on the plate surface.

[0004] The former thermal transfer method can relatively easily form a matte surface, but has the problem that the transferred irregularities return to the original shape when heat is applied during secondary processing. The latter internal matting method can maintain the uneven shape even in the secondary processing, but is relatively expensive. In recent years, in the context of residential buildings, there has been a strong demand for installing blinds on terraces and verandas from the viewpoint of privacy protection, and it is often the case that mats made of acrylic resin, which are excellent in weather resistance, lightweight and relatively inexpensive, can be attached. More and more.

[0005] However, recently, in the event of a fire accident, there has been a report that combustible materials placed on a veranda or the like contribute to speeding up the spread of fire, and attention has been paid to the burning performance of the blindboard itself. Specifically, the movement is to change the blindboard to a nonflammable or self-extinguishing material. Unfortunately, the acrylic resin plate itself is slowly flammable, and once ignited, it keeps burning, making it difficult to respond to this new movement. Therefore, a polycarbonate resin plate is the most noticeable material as a self-extinguishing material replacing the acrylic resin plate.

[0006] The polycarbonate resin matting plate itself is not particularly new, and polycarbonate resin is conventionally used instead of acrylic resin in parts where impact resistance, heat resistance, flame resistance and the like are required. . However, the polycarbonate resin plate has poor weather resistance as compared with the acrylic resin, and when exposed to ultraviolet light outdoors or the like, many problems such as discoloration and reduction in strength occur in a relatively short time. Therefore, conventionally, it could be used only indoors and only in a place where the influence of ultraviolet rays is small.

As a method for improving the weather resistance of the polycarbonate resin plate, many methods have recently been reported in which the surface of the polycarbonate resin plate is coated with an acrylic resin. In particular, by adding an ultraviolet absorber to the acrylic resin to be coated, the weather resistance is improved so as to make the user forget that the base material is a polycarbonate resin. (For example, Tokiko Sho 47
No. 19119, Japanese Patent Publication No. 55-27848,
JP-A-55-59929, JP-A-59-1013
No. 60 publication and the like. By these techniques, the weather resistance of the polycarbonate resin plate can be sufficiently improved to a practical level, and greatly contributes to the expansion of the use of the polycarbonate resin plate in outdoor use.

The acrylic resin-coated polycarbonate resin plate, which is a self-extinguishing material, has excellent impact resistance, and has sufficiently improved weather resistance, is also in the spotlight for the above-mentioned blinds such as terraces and verandas. It has been subjected to surface matting by the above-described thermal transfer method, and is being studied by various companies. However, recently, problems have been pointed out when the surface of the acrylic resin-coated polycarbonate resin plate is matted by a thermal transfer method.

The thermal transfer method is a method in which a resin in a heated and molten state is brought into close contact with a mold having a matte surface, cooled and solidified, and the uneven shape is transferred to the plate surface. In the case of an acrylic resin-coated polycarbonate resin plate, In addition, since the heat resistance temperature of the acrylic resin of the coating layer is lower than that of the polycarbonate resin of the base material layer by 40 ° C. or more, there is a problem that the uneven shape of the mold cannot be transferred well. Specifically, for example,
The coating layer acrylic resin melts due to the heat of the base layer polycarbonate resin, and the irregularities are crushed, and the coating layer acrylic resin adheres to the mold and cannot be peeled off, leaving traces on the plate surface If processed in accordance with the heat resistance temperature of the coating layer acrylic resin, on the other hand, large distortion occurs in the base layer polycarbonate resin, and it warps, causing various appearance defects such as portions where unevenness is not transferred. It is.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polycarbonate resin plate having a matte surface which has improved weather resistance and does not have a poor appearance due to thermal transfer.

[0011]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have made intensive studies and as a result, by forming the coating layer containing the ultraviolet absorbent with the same polycarbonate resin as the base material layer, the thermal transfer of The present inventors have found that poor appearance at the time can be improved, and have completed the present invention.

That is, the present invention provides a polycarbonate resin laminate in which a coating layer polycarbonate resin containing 1 to 20% by weight of an ultraviolet absorber is laminated on one or both sides of a substrate layer polycarbonate resin, A matte polycarbonate resin laminate having a surface with a 60-degree specular gloss of 80% or less. The present invention also provides the above-mentioned matte polycarbonate resin laminate, wherein the thickness of the above-mentioned coating layer polycarbonate resin layer is 1 to 200 µm.

Hereinafter, the present invention will be described in detail. In the present invention, as the polycarbonate resin used for the coating layer and the base material layer, a polymer derived from a divalent phenolic compound represented by bisphenol A is used. The method for producing the polycarbonate resin is not particularly limited, and the polycarbonate resin can be produced by a method such as a phosgene method, a transesterification method, and a solid phase polymerization method. Although the molecular weight is not particularly limited, it is preferably from 20,000 to 70,000, more preferably from 30,000 to 60,000 in terms of weight average molecular weight, from the viewpoint of forming a plate having a desired thickness by extrusion or the like. Further, various heat stabilizers, antioxidants and the like can be added to the polycarbonate resin in order to improve the thermal decomposition property and the thermal coloring property during molding. In addition, coloring may be performed by blending an organic or inorganic dye or bluing agent, or various additives such as an antistatic agent may be blended.

In the present invention, examples of the ultraviolet absorber incorporated in the coating layer polycarbonate resin include an ultraviolet absorber composed of a benzotriazole compound, a benzophenone compound, a hydroxyphenyltriazine compound, a salicylic acid phenylester compound, or the like. .
Examples of the benzotriazole-based compound include 2- (5-methyl-2-hydroxyphenyl) -2H-benzotriazole and 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzo. Triazole, 2- (2′-hydroxy-5′-t-octylphenyl) benzotriazole, 2,2-methylenebis [4
-(1,1,3,3-tetramethylenebutyl) -6-
(2H-benzotriazol-2-yl) phenol], and the like, and examples of the benzophenone-based compound include 2-hydroxy-4-octoxybenzophenone,
2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-4′-chlorobenzophenone, 2,2
-Dihydroxy-4-methoxybenzophenone, 2,2
-Dihydroxy-4,4'-dimethoxybenzophenone and the like.

[0015] Examples of the ultraviolet absorber comprising a hydroxyphenyltriazine compound include, for example, 2,4-
Diphenyl-6- (2-hydroxy-4-methoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-ethoxyphenyl)-
1,3,5-triazine, 2,4-diphenyl-6
(2-hydroxy-4-propoxyphenyl) -1,
3,5-triazine, 2,4-diphenyl-6- (2-
(Hydroxy-4-butoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-hexyloxyphenyl) -1,3,5-triazine, 2,4-diphenyl- 6- (2-hydroxy-4
-Octyloxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-
Dodecyloxyphenyl) -1,3,5-triazine,
2,4-diphenyl-6- (2-hydroxy-4-benzyloxyphenyl) -1,3,5-triazine, 2,
4-diphenyl-6- (2-hydroxy-4- (2-butoxyethoxy) phenyl) -1,3,5-triazine, 2,4-di-p-toluyl-6- (2-hydroxy-4-methoxy Phenyl) -1,3,5-triazine,
2,4-di-p-toluyl-6- (2-hydroxy-4
-Ethoxyphenyl) -1,3,5-triazine, 2,
4-di-p-toluyl-6- (2-hydroxy-4-propoxyphenyl) -1,3,5-triazine, 2,4
-Di-p-toluyl-6- (2-hydroxy-4-butoxyphenyl) -1,3,5-triazine, 2,4-di-p-toluyl-6- (2-hydroxy-4-hexyloxyphenyl ) -1,3,5-Triazine, 2,4-
Di-p-toluyl-6- (2-hydroxy-4-octyloxyphenyl) -1,3,5-triazine, 2,4
-Di-p-toluyl-6- (2-hydroxy-4-dodecyloxyphenyl) -1,3,5-triazine, 2,
4-di-p-toluyl-6- (2-hydroxy-4-benzyloxyphenyl) -1,3,5-triazine,
2,4-di-p-toluyl-6- (2-hydroxy-4
-(2-hexyloxyethoxy) phenyl) -1,
Examples of 3,5-triazine and the like, and examples of salicylic acid phenyl ester-based ultraviolet absorbers include para-t-butylphenylsalicylate and para-octylphenylsalicylate.

Of these, ultraviolet absorbers composed of benzotriazole-based compounds and hydroxyphenyltriazine-based compounds, which are more difficult to volatilize, are more preferable. Further, the amount of the ultraviolet absorber incorporated in the coating layer polycarbonate resin is preferably 1 to 20% by weight, more preferably 2 to 1% by weight.
5% by weight. When the amount is less than 1% by weight, the weather resistance effect is small, and when it exceeds 20% by weight, the weather resistance is certainly excellent, but the initial coloring is large and the appearance is problematic.

There is no particular limitation on the method for blending the above-mentioned ultraviolet absorber with the coating layer polycarbonate resin. For example, a method of dry-blending the coating layer polycarbonate resin and the ultraviolet absorbent with a drum blender, a Henschel mixer, or the like, a method of mixing and then pelletizing through an extruder, or a method of extruding the coating layer polycarbonate resin using an extruder while extruding ultraviolet light. Any method of injecting the absorbent into the extruder with a metering pump and mixing inside the extruder may be used.

As a method for preparing a polycarbonate resin laminate by coating a polycarbonate resin plate on the base material layer with a coating resin containing an ultraviolet absorbent, for example, a polycarbonate resin plate on the base material layer is prepared by extrusion. In the step of co-extrusion, a polycarbonate resin serving as a coating layer containing a UV absorber is simultaneously melt-extruded and laminated, or a polycarbonate resin film containing a UV absorber serving as a coating layer previously formed into a film. The film lamination method of bonding the base layer polycarbonate resin plate surface with heat or an adhesive, etc., dipping or roll coating, spin coating, and the coating layer polycarbonate resin mixed with an ultraviolet absorber on the base layer polycarbonate resin plate surface. Coating method applied by flow coating etc. Etc., and the like.

The thickness of the coating layer of the polycarbonate resin laminate thus manufactured is preferably from 1 to 200 μm, more preferably from 5 to 150 μm. When the thickness of the coating layer is less than 1 μm, the effect of improving the weather resistance is not always sufficient, and when it exceeds 200 μm, the initial coloring becomes slightly large, which may cause a problem in appearance. In the present invention, as a method for making the surface of the polycarbonate resin laminated board a matte surface, the above-described thermal transfer method and the internal matting method are mentioned, but the effect of using the same polycarbonate resin as the coating layer and the base material layer is exhibited. Is a thermal transfer method.

The matte surface processing method by the thermal transfer method will be described in more detail. The polycarbonate resin laminate in a heat-softened state or a molten state is brought into close contact with a mold having a matte shape heated to 100 to 150 ° C. Then, the irregular shape of the mold surface is transferred to the surface of the polycarbonate resin laminate. After that, it is cooled and solidified to obtain a matte polycarbonate resin laminate.

The matte state of the surface of the matte polycarbonate resin laminate thus produced is preferably 80% or less, more preferably 60% or less in terms of 60 ° specular gloss. When the 60-degree specular gloss exceeds 80%,
The matte state of the surface is glaring, which is not preferable in terms of aesthetics. The smaller the value of the 60-degree specular gloss is, the more preferable it is. However, in order to make the value smaller, the shape of the mold becomes more complicated and it cannot be said that it is technically easy. Therefore, in the current state of the art, the lower limit is considered to be practically about 5%.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described more specifically with reference to the following Examples and Comparative Examples, but the present invention is not limited thereto. The evaluation and test methods used in each Example and Comparative Example are shown below. (1) 60-degree specular glossiness: Based on JIS K7105, a 60-degree specular glossiness of a 5 cm square test piece cut out from the prepared matte polycarbonate resin laminate was measured. (2) Initial coloration: 5 cut out from the matte polycarbonate resin laminate prepared according to JIS K7105.
The degree of yellowness of a cm square test piece was measured.

In general, when the yellowness exceeds 4, the coloration of the test specimen is clearly visible. In this evaluation, when the yellowness of the test piece was less than 4, the initial coloring was evaluated as ◎, that is, the initial coloring was small, and when the yellowness was 4 or more, the initial coloring was evaluated as x, that is, the initial coloring was large. ) Weather resistance: Using a 10 cm square test piece cut out from the prepared matte polycarbonate resin laminate, using Sunshine Super Long Life Carbon with a Sunshine Weather Meter manufactured by Suga Test Instruments, at a constant temperature of 63 ° C and without rainfall for 2 hours The test piece was exposed for 5000 hours under the conditions of repeating a cycle of 18 minutes of rainfall.

As the evaluation, the change in yellowness before and after exposure was evaluated as J.
It was measured based on IS K 7105. Yellowness = (Yellowness before exposure)-(Yellowness before exposure) If the value of yellowness is large, the result of the weathering test compared to the initial value indicates that the yellowish color became deeper (colored) Means that when the yellowing degree exceeds 4, it is clearly visible by visual observation that coloring has occurred.

In this evaluation, when the degree of yellowing is less than 4, weather resistance is evaluated as 、, that is, no coloring occurs even when used for a long time, and when the degree of yellowing is 4 or more, weather resistance X, that is, when used for a long time Was evaluated as causing coloring.

[0026]

Example 1 To a polycarbonate resin (trade name: Panlite, manufactured by Teijin Chemicals Ltd.), 2,4-diphenyl-6-
(2-hydroxy-4-hexyloxyphenyl)-
3% by weight of a hydroxyphenyltriazine-based UV absorber composed of 1,3,5-triazine is mixed, melt-kneaded in a vented 30 mm twin-screw extruder at an extrusion temperature of 280 ° C., and extruded into pellets to form a polycarbonate coating layer. A resin pellet was obtained.

The thus-obtained polycarbonate resin pellets of the coating layer were manufactured by Toshiba Machine Co., Ltd.
/ D = 32 using an extruder, and at the same time, a polycarbonate resin for a base material layer (trade name; Panlite, manufactured by Teijin Chemicals Ltd.)
Polycarbonate coated with a polycarbonate resin coated with a hydroxyphenyltriazine-based UV absorber on both sides of a base layer polycarbonate resin by co-extrusion using an extruder manufactured by Toshiba Machine Co., Ltd. with a diameter of 100 mm and L / D = 32. A resin laminate was obtained. The co-extrusion die used a feed block system, the die set temperature was 270 ° C., and the extruder cylinder temperature was all 290 ° C. The thickness of the coating layer was adjusted by adjusting the discharge amount of both extruders and the flow rate adjustment bolt of the die so that the thickness of the coating layer was 30 μm on each side.

The laminated molten resin discharged from the die is usually formed into a plate shape by passing through a temperature-controlled glazing roll. In this embodiment, the matte shape is controlled at 140 ° C. The laminated molten resin was passed through three rolls whose surfaces were processed to continuously transfer the matte unevenness shape to the front and back of the laminate by the rolls, and obtained a matte polycarbonate resin laminate while extruding. .

The matte surface of the matte polycarbonate resin laminate thus obtained is very good without crushing irregularities, scratches, and peeling off from the roll, and the glossiness of the matte surface is measured. As a result, the specular glossiness at 60 degrees was 40%. When the matte polycarbonate resin laminate obtained according to the test method described above was evaluated, the initial coloring (yellowness = 0.5) and the weather resistance (yellowness = 2) were good.

[0030]

[Comparative Example 1] Acrylic resin (trade name, manufactured by Asahi Kasei Corporation; Delpet) was treated with 2,4-diphenyl-6- (2-hydroxy-4-hexyloxyphenyl) -1,3,5-triazine. A phenyltriazine-based ultraviolet absorber (3% by weight) was mixed, melt-kneaded at an extrusion temperature of 260 ° C. in a vented 30 mm twin-screw extruder, and extruded into pellets to obtain coating layer acrylic resin pellets.

The coating layer acrylic resin pellets thus obtained were manufactured by Toshiba Machine Co., Ltd., diameter 50 mm, L / D = 32.
And a polycarbonate resin for a base material layer (manufactured by Teijin Chemicals Ltd., trade name: Panlite) was co-extruded with a Toshiba Machine Co., Ltd. extruder having a diameter of 100 mm and L / D = 32. An acrylic resin-coated polycarbonate resin laminate in which a coating layer acrylic resin in which a hydroxyphenyltriazine-based ultraviolet absorber was blended on both sides of the layer polycarbonate resin was obtained. The co-extrusion die used was a feed block system, and the die set temperature was 270 ° C., and the extruder cylinder temperature was 290 ° C. on the base layer polycarbonate resin side and 270 ° C. on the coating layer acrylic resin side.

The thickness of the coating layer was adjusted by adjusting the discharge rate of both extruders and the flow rate adjusting bolt of the die so that the thickness of each coating layer was 30 μm on each side. The laminated molten resin discharged from the die is usually formed into a plate by being passed through a temperature-controlled glazing roll.
The laminated molten resin is passed through three rolls whose surfaces are processed into a matte shape that has been temperature-controlled to continuously transfer the matte unevenness shape to the front and back surfaces of the laminate by the rolls, and then extrude and matte. A polycarbonate resin laminate was obtained.

The matte surface of the matte polycarbonate resin laminate thus obtained has slightly smaller irregularities.
Marks of peeling off from the roll are severely appearing on the surface of the laminate, which is problematic in appearance. The gloss of the matte surface was measured, and it was 90% as a 60-degree specular gloss. However, the result of evaluating the matte polycarbonate resin laminate obtained according to the above-described test method is very good because the coating layer is an acrylic resin, and the initial coloring ◎ (yellowness =
0.5) and weather resistance ◎ (yellowing degree = 2).

[0034]

Comparative Example 2 Without a coating layer, only a polycarbonate resin for a substrate layer (manufactured by Teijin Chemicals Ltd., trade name: Panlite) was extruded independently using an extruder manufactured by Toshiba Machine Co., Ltd., having a diameter of 100 mm and L / D = 32. . 140 ℃ of molten resin discharged from die
The molten resin is passed through three rolls whose surfaces have been processed into a matte shape that has been temperature-controlled to continuously transfer the matte unevenness shape to the front and back of the single-layer plate by the roll, and then extrude and matte. A polycarbonate resin single layer plate was obtained.

The matte surface of the thus-obtained matte polycarbonate resin single-layer plate is very good without crushing irregularities, scratches, and peeling off from the roll. As a result of the measurement, the 60-degree specular gloss was 40%. However, when the matte polycarbonate resin single-layer plate obtained according to the test method described above was evaluated, it was found that the weather resistance was poor and it was difficult to use it outdoors. Initial coloring ◎ (yellowness = 0.5), weather resistance × (yellowing degree = 15).

[0036]

[Comparative Example 3] Same as Example 1 except that the surface of the matte roll (die) was subjected to cutting, and the matte roll (die) having a 60 ° mirror gloss of about 1% was used. To obtain a matte polycarbonate resin laminate. Unfortunately, however, it was not possible to completely transfer the irregularities of the roll to details, and unevenness due to the degree of glossiness occurred on the matte surface. At this time, the 60-degree specular glossiness was about 3% on average.

However, the results of evaluating the matte polycarbonate resin laminate obtained according to the above-mentioned test method were very good, and the initial coloring (yellowness = 0.5) and the weather resistance were excellent.
(Yellowing degree = 2)

[0038]

Comparative Example 4 Contrary to Comparative Example 3, 60
Roll (die) with a mirror gloss of about 100%
Was performed in the same manner as in Example 1 except that a matte polycarbonate resin laminate was obtained. The matte surface of the matte polycarbonate resin laminate obtained in this manner was very good without crushing of irregularities, abrasion, and peeling off from the roll, but the matte state of the surface was glaring. It is aesthetically a matter of feeling. The gloss of the matte surface was measured and found to be 100% with a 60-degree specular gloss.

However, when the matte polycarbonate resin laminate obtained according to the test method described above was evaluated,
Initial coloring ◎ (yellowness = 0.5), weather resistance ◎ (yellowing degree =
2) was good.

[0040]

Examples 2 to 5 and Comparative Examples 5 to 8 Coating layer The same procedure as in Example 1 was carried out except that the thickness of the polycarbonate resin layer or the amount of the ultraviolet absorber mixed in the coating layer was changed as shown in Table 1. Then, a matte polycarbonate resin laminate was obtained. Table 1 shows the evaluation results of the matte polycarbonate resin laminates obtained as described above.

[0041]

[Table 1]

[0042]

According to the present invention, it is possible to provide a polycarbonate resin plate having a matte surface having improved weather resistance and having no appearance defect due to thermal transfer,
Expanding applications such as building materials are expected as self-extinguishing, impact-resistant and heat-resistant materials regardless of whether indoors or outdoors.

Claims (2)

[Claims] 1. A polycarbonate resin laminate in which a coating layer polycarbonate resin containing an ultraviolet absorber in an amount of 1 to 20% by weight is laminated on one or both surfaces of a base material layer polycarbonate resin. A matte polycarbonate resin laminate having a degree of specular gloss of 80% or less. 2. The coating layer having a polycarbonate resin layer thickness of 1
The matte polycarbonate resin laminate according to claim 1, which has a thickness of from 200 to 200 µm.