JP3457514B2 - Laminated plate and method of manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate and a method for producing the same, and more particularly to a polycarbonate resin laminate coated with an acrylic resin having excellent transparency and weather resistance and a method for producing the same. The laminated plate of the present invention is
It can be used in a wide variety of fields such as various glazing applications, signboards, soundproof walls for automobile roads, front plates of vending machines, carports and the like where weather resistance is required.

[0002]

2. Description of the Related Art Polycarbonate resins are widely used in carports, signboards, etc. because of their excellent transparency and impact resistance, and their applications are expected to expand in the future. However, since the polycarbonate resin has insufficient weather resistance as compared with the acrylic resin,
In the case of outdoor applications that are exposed to direct sunlight or the like, discoloration such as reduction in impact strength or yellowing may be a problem. The following methods have been proposed as methods for improving these problems. A method of coating a polycarbonate substrate with an acrylic resin layer containing an ultraviolet absorber (Japanese Patent Publication No. 47-1911).
No. 9, JP-A-55-59929). A method of coating an acrylic resin layer with a flexibility and impact resistance similar to that of polycarbonate by using an impact-modified acrylic resin, for example, a soft acrylic resin, and coating the same on a polycarbonate substrate. −
175245, Japanese Patent Laid-Open No. 4-270652).

However, when the above method is adopted, the weather resistance is improved, but the impact strength of the laminated plate in which a polycarbonate resin substrate is coated with a normal acrylic resin is lowered. This phenomenon is that the hard acrylic resin layer breaks first when shocked,
It is speculated that the polycarbonate layer and the acrylic resin layer are in close contact with each other, so that the polycarbonate resin layer is also broken at the time of impact.

Even when the method (1) is adopted, when the laminated plate is manufactured by coextrusion molding, an interlayer instability phenomenon occurs at the interface between the resin for the substrate layer and the resin for the coating layer. There was a problem that it was difficult to obtain a good surface condition. This phenomenon is more clearly recognized when trying to obtain a laminated board having a thin acrylic resin layer. Therefore, when the coating layer is thin, the surface condition is poor, and therefore a good impact resistance is obtained. It will not be possible. And this phenomenon is particularly likely to occur when performing bank molding with a molding roll and mirror-finishing the surface after laminating and integrating by a coextrusion molding method, and when the fluctuation of the bank becomes large, There are problems that surface defects due to bank shapes such as bank marks are likely to occur, and it is difficult to obtain a laminated plate having a good surface condition.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a laminated board excellent in weather resistance, transparency and surface property and a method for producing the same, without impairing the impact resistance originally possessed by the polycarbonate resin. To provide.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made earnest studies in order to obtain a laminate having excellent impact strength by coextrusion molding without causing an instability phenomenon between layers and fluctuation in a bank. Overlaid. As a result, when the melt viscosities of the polycarbonate resin used as the substrate layer and the acrylic resin used as the coating layer have a specific relationship, a laminated plate having a good surface condition can be obtained without causing an interface instability phenomenon or fluctuation in a bank. The inventors have found that they can be obtained and completed the present invention.

That is, according to the present invention, the above object is such that, on at least one surface of the polycarbonate resin layer, 28 to 94.8% by weight of a methacrylic resin, 5 to 70% by weight of a crosslinked acrylate elastomer and an ultraviolet absorber. 0.2 ~
Acrylic resin layer consisting of 2% by weight 10-150 μm
Of the polycarbonate resin (A) and the acrylic resin (B) at 250 ° C. for 100 s ⁻¹
The laminate having a viscosity ratio (A / B) at a shear rate of 1.9 or more, and a polycarbonate resin, a methacrylic resin of 28 to 94.8% by weight, a crosslinked acrylic acid ester-based elastic body of 5 to 70% by weight, and UV absorber 0.2 ~
Acrylic resin having a thickness of 10 to 150 μm is obtained by co-extrusion molding with a resin composition of 2% by weight to laminate and integrate an acrylic resin layer on at least one surface of a polycarbonate resin layer, and perform bank molding with a molding roll. When the layer is provided on the polycarbonate resin layer, 250 ° C., 100
Polycarbonate resin (A) at shear rate of s ^-1
And the acrylic resin (B) has a viscosity ratio (A / B) within a range of 1.9 or more.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The polycarbonate resin constituting the substrate layer in the present invention is not particularly limited and, for example, a carbonic acid ester polymer mainly containing bisphenol A is used. The molecular weight of the polycarbonate resin used is not particularly limited, but since the plate-like body is usually produced by extrusion molding, the viscosity average molecular weight thereof is 15,000 to 3
It is preferably about 0000, and the melt viscosity at 250 ° C. and 100 s ⁻¹ is 1300 to 100 from the viewpoint of moldability.
60,000 poise, preferably 30,000 to 50,000
Poise is preferable. For polycarbonate resin,
Various commonly used additives may be added, and examples of the additive include an ultraviolet absorber, an antioxidant, a flame retardant, a colorant and the like. The thickness of the polycarbonate resin layer is not particularly limited, but usually 0.5 to 15 mm, preferably 1 to 10 mm is adopted from the viewpoint of use as a glazing material.

The methacrylic resin, which is one resin component constituting the coating layer in the present invention, is not particularly limited as long as it can be melt-kneaded by a screw extruder and extruded into a plate shape from a die. Mention may be made of a methacrylate homopolymer or a copolymer containing a methyl methacrylate unit in an amount of 50% by weight or more, preferably 80% by weight. Examples of other monomers copolymerizable with methyl methacrylate include methyl acrylate, ethyl acrylate, and butyl acrylate. These can be used alone or in combination of two or more. Methacrylic resin is
From the viewpoint of moldability, the melt viscosity at 250 ° C. and 100 s ⁻¹ is 5000 to 31000 poise, preferably 50.
It is preferably in the range of 2000 to 20000 poise. Various commonly used additives may be added to the methacrylic resin, and examples of the additives include an antioxidant, a flame retardant, and a colorant. The method for producing the methacrylic resin is not particularly limited, and known methods such as bulk polymerization, suspension polymerization and solution polymerization can be used.

The crosslinked acrylic acid ester-based elastic body, which is another resin component constituting the coating layer in the present invention, is a rubber component blended in order to improve the impact strength of the laminate. The crosslinked acrylic acid ester-based elastic body is not particularly limited as long as it does not impair the impact resistance, which is the object of the present invention, and those having various layer structures can be used. Examples thereof include those having a two-layer structure, a three-layer structure, and a four-layer structure in which a polymer and a soft cross-linking polymer mainly composed of an acrylic ester having a rubber-like property are layered. The crosslinked acrylic acid ester-based elastic body usually has a spherical structure composed of two or more layers, and the average particle diameter thereof is preferably about 0.1 to 0.3 μm.

The crosslinked acrylic acid ester-based elastic material is an impact-resistant methacrylic resin containing a crosslinked acrylic acid ester-based elastic material having various layer structures as a rubber component from the viewpoint of melt-mixability with the methacrylic resin. Preference is given to using. For example, 70 to 90% by weight of at least one kind of alkyl acrylate having 1 to 8 carbon atoms in the alkyl group
And styrene alone or a mixture of styrene and its derivatives 9.9 to 29.9% by weight and copolymerizable therewith 1
Crosslinked acrylic acid ester-based elastic latex obtained by using 0.1 to 10% by weight of a polyfunctional monomer having two or more double bonds in the molecule, such as allyl acrylate and allyl methacrylate, or methyl Outside the hard crosslinked resin particles containing 80% by weight or more of methacrylate units, 70 to 90% by weight of at least one alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and styrene alone or a mixture of styrene and its derivative 9.9. .About.29.9% by weight and 0.1 to 10% by weight of a polyfunctional monomer having two or more double bonds in one molecule which is copolymerizable therewith, such as allyl acrylate and allyl methacrylate. In the presence of the crosslinked acrylic acid ester-based elastic latex having the obtained polymer layer, 80 to 100% by weight of methyl methacrylate is added. , At least one 0-20% by weight of alkyl acrylate carbon atoms in the alkyl group 1 to 8, and this and other copolymerizable vinyl monomer 0-1
It can be obtained by emulsion polymerization of a monomer mixture consisting of 0% by weight. In the above-mentioned manufacturing method, the impact-resistant methacrylic resin containing the crosslinked acrylic ester-based elastic body can be manufactured in one step by increasing the quantitative ratio of the methacrylic resin component in the outermost layer.

As a method for producing the above-mentioned multi-layered structure, an emulsion polymerization method or the like in which a monomer mixture constituting each layer is sequentially polymerized from the inner layer is usually used. There are no particular restrictions on the selection, whether or not a chain transfer agent is added to the outermost layer, and the like. Further, the proportion of the crosslinked acrylic acid ester-based elastic material in the impact resistant methacrylic resin is preferably about 20 to 70% by weight.

From the viewpoint of flexibility, impact strength, etc., the acrylic resin layer constituting the coating layer of the laminated plate contains 10 to 70% by weight of the crosslinked acrylic ester elastomer.
It is preferably 20 to 50% by weight.
When the content is less than 10% by weight, it may be difficult to impart flexibility and impact strength that do not impair the impact strength of the polycarbonate resin substrate, which is not preferable.
On the other hand, if it exceeds 70% by weight, the flowability of the acrylic resin is deteriorated and the melt extrusion may become difficult, which is not preferable.

The ultraviolet absorber used in the present invention is added for the purpose of improving the weather resistance of the laminated plate, and the kind thereof is not particularly limited.
One or more selected from known ultraviolet absorbers such as hindered amine type and benzophenone type are used. The content of the ultraviolet absorber is 0.2 to 2% by weight, preferably 0.5 to 1.5% by weight. Addition amount is 0.2
If it is less than wt%, the weather resistance that can withstand outdoor use cannot be obtained, and it is not preferable. On the other hand, even if the amount added exceeds 2 wt%, it is difficult to say that an effect commensurate with the addition cost can be obtained. An excessive amount of addition is not preferable because slippage may occur in the extruder, or volatile matter may stain the molding roll.

In the present invention, the method for mixing the methacrylic resin, the impact-resistant methacrylic resin and the ultraviolet absorber is not particularly limited, and for example, a predetermined amount of them is mixed with a tumbler or the like and then directly mixed in an extruder. Examples thereof include a method of supplying to the filling hopper, a method of mixing the mixture by the above-mentioned method and then forming a pellet having a uniform composition through an extruder, and supplying the pellet to the filling hopper of the extruder. It is also possible to mix the methacrylic resin obtained by emulsion polymerization and the impact-resistant methacrylic resin in an emulsion state, take out the resin component from this by spray drying, freeze drying, etc., and then add and mix an ultraviolet absorber to this. .

The laminate of the present invention has a methacrylic resin 28 to 9 on at least one surface of the polycarbonate resin layer.
4.8% by weight, preferably 28.5-94.5% by weight,
An acrylic resin layer comprising 5 to 70% by weight of a crosslinked acrylic acid ester elastic body and 0.2 to 2% by weight of an ultraviolet absorber is provided in a thickness of 10 to 150 μm, preferably 50 to 120 μm. 250 ° C of the polycarbonate resin (A) and the acrylic resin (B),
The viscosity ratio (A / B) at a shear rate of 100 s ^-1 needs to be 1.9 or more. When the thickness of the acrylic resin layer is less than 10 μm, it is not preferable in terms of weather resistance, while when it exceeds 150 μm, it is not preferable in terms of impact resistance.

The method for producing the laminated plate of the present invention is not particularly limited, but for example, a polycarbonate resin and a methacrylic resin 28 to 94.8% by weight, preferably 28.5 to 94.5% by weight, a crosslinked acrylic resin. A resin composition comprising 5 to 70% by weight of an acid ester elastic body and 0.2 to 2% by weight of an ultraviolet absorber is co-extrusion-molded to integrally laminate an acrylic resin layer on at least one surface of a polycarbonate resin layer. When forming an acrylic resin layer having a thickness of 10 to 150 μm on the polycarbonate resin layer by performing bank forming with a forming roll, the
Viscosity ratio (A / B) of polycarbonate resin (A) and acrylic resin (B) at a shear rate of 100 s ^-1 at 100 ° C
It is preferable to use a resin satisfying the condition of 1.9 or more.

A specific example of the manufacturing process of the laminated plate is shown below.
As an extruder used for manufacturing a laminated plate, generally, one main extruder for extruding a polycarbonate resin forming a substrate layer and one or more sub-extruders for extruding an acrylic resin forming a coating layer are used. The sub-extruder used is usually smaller than the main extruder.
The temperature condition of the main extruder is usually 230 to 280.
C., preferably 240 to 260.degree. C., and the temperature condition of the sub-extruder is usually 220 to 250.degree. C., preferably 230 to 240.degree. As a method of laminating two or more kinds of molten resins, known methods such as a feed block method and a multi-manifold method can be used.
In this case, the molten resin laminated in the feed block is
After being guided to a sheet forming die such as a T-die and formed into a sheet, the sheet is introduced into a forming roll (polishing roll) whose surface is mirror-finished to form a bank. The sheet-like material is mirror-finished and cooled while passing through a forming roll to form a laminated plate. In the case of a multi-manifold die, the molten resin laminated in the die is similarly shaped into a sheet inside the die, and then surface finishing and cooling are performed with a forming roll to form a laminated plate. Is formed. The die temperature is usually 220 to 270.
C, preferably 230 to 260 ° C., and the temperature of the forming roll is usually 100 to 160 ° C., preferably 11
It is 0 to 140 ° C.

When different resins such as a polycarbonate resin and an acrylic resin are laminated by a feed block system or a multi-die system as in the method of the present invention, the molten resin is joined at the interface between the two resins. , An inter-layer instability phenomenon such as a wavy fold is generated. As for the cause of this interlayer instability phenomenon, various theories such as shear stress at the interface, normal stress at the interface, such as instability phenomenon of multi-layer flow, have been proposed, and the melt viscosity of different kinds of resins constituting the substrate layer and the coating layer may be considered. There is a theory that the interlayer instability phenomenon can be eliminated by combining them, but it is hard to say that the cause is still completely understood. Further, the inventors of the present invention, when a polycarbonate resin and an acrylic resin are laminated and integrated and trying to perform bank molding with a molding roll, fluctuation in the bank becomes large, and surface defects caused by banks such as bank marks and sink marks are generated. We have repeatedly experienced that it is not easy to obtain a laminated plate that is likely to occur and has an excellent appearance.

In order to solve the problems such as the interlayer instability phenomenon at the merging portion and the fluctuation in the bank, the present inventors have paid attention to the polycarbonate resin used for the substrate layer and the acrylic resin used for the coating layer for various studies. As a result, it was found that there is a relationship between the melt viscosity of the polycarbonate resin and the acrylic resin used, the interlayer instability phenomenon, and the fluctuation in the bank. That is, when the ratio of the melt viscosity between the polycarbonate resin and the acrylic resin is increased (that is, when the value of “the viscosity of the polycarbonate resin / the viscosity of the acrylic resin” is increased), the interlayer instability phenomenon or the bank It was found that bank defects due to fluctuations tended to be suppressed.

The inventors of the present invention have conducted further studies to find that when the melt viscosities of the polycarbonate resin and the acrylic resin satisfy a certain relationship, the bank instability caused by the interlayer instability phenomenon and the fluctuation in the bank are caused. It has been found that a defect does not occur at all and a laminate having an excellent appearance can be obtained. That is, when the viscosity ratio (A / B) of the polycarbonate resin (A) and the acrylic resin (B) at a shear rate of 250 ° C. and 100 s ⁻¹ is 1.9 or more, preferably 2 to 5, interlayer instability is caused. It was found that a bank defect due to a phenomenon or fluctuation in a bank does not occur and a laminated plate having an excellent appearance can be obtained. 250 ° C of polycarbonate resin (A) and acrylic resin (B), 1
The viscosity ratio (A / B) at a shear rate of 00 s ⁻¹ is 1.
If it is less than 9, the fluctuation of the bank at the time of forming the bank becomes large and surface defects due to the bank such as bank marks and sink marks are likely to occur, which is not preferable. When the viscosity ratio A / B is smaller than 1.6, in addition to bank defects caused by bank fluctuations, an interlayer instability phenomenon becomes conspicuous at the junction of the polycarbonate resin and the acrylic resin, which is not preferable. In particular, when the viscosity ratio A / B approaches 1, the interlayer instability phenomenon becomes remarkable at the confluence of the polycarbonate resin and the acrylic resin, and defects such as bank marks due to bank fluctuation are more clearly recognized. This is not desirable.

[0023]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. The measurement and evaluation in the examples were performed by the following methods.

(Measurement of Melt Viscosity) Using a Toyo Seiki Capillograph (type 28-125) (temperature range: 60 to
400 ° C, barrel diameter: 9.55 mmφ), 250 ° C, 1
It was measured under the condition of a shear rate of 00 s ^-1 .

(Evaluation of Appearance of Laminated Plate and Evaluation of Bank Fluctuation) Interlayer instability phenomenon and bank fluctuation were evaluated by visually observing the appearance of the obtained laminated plate. The fluctuation of the bank on the forming roll was increased by intentionally adjusting the balance between the amount of extrusion and the amount of polishing, and judged from the ease of occurrence of bank marks and sink marks.

The resin raw materials which are the polycarbonate resin, methacrylic resin, impact-resistant methacrylic resin, ultraviolet absorber, and mixture thereof used in the examples are shown below. (Polycarbonate resin) (a) Caliber PCX-3354 (Sumitomo Dow, viscosity average molecular weight 22000) (b) Lexan 121R (GE plastic, viscosity average molecular weight 22000) (c) Lexan SP1210 (GE plastic, viscosity average molecular weight 19000) ) (D) Taflon I-2600K (made by Idemitsu Petrochemical, viscosity average molecular weight 26000)

(Methacrylic resin) (e) Methyl methacrylate unit of 94% by weight, methyl acrylate unit of 6% by weight, weight average molecular weight of 160
000 (f) Methyl methacrylate unit 91.5% by weight, methyl acrylate unit 8.5% by weight, weight average molecular weight 115000 (g) Methyl methacrylate unit 92% by weight, methyl acrylate unit 8% by weight, weight average molecular weight 109
000

(Impact-resistant methacrylic resin) 74% by weight of a crosslinked acrylic acid ester-based polymer obtained by freezing, melting and drying a three-layer structure polymer latex obtained by the following three-step polymerization The contained powder was used. (First stage) Ion-exchanged water 3 in a reaction vessel equipped with a reflux condenser
00 parts by weight, 1 part by weight of sodium stearate and 0.08 part by weight of sodium N-lauroyl sarcosinate were added and heated to 70 ° C. under a nitrogen atmosphere with stirring, and then 50 parts by weight of methyl methacrylate (MMA). , 2 parts by weight of methyl acrylate (MA), allyl methacrylate (ALM
A) A monomer mixture consisting of 0.15 parts by weight was added.
Then, 0.6 part by weight of a 10% potassium persulfate (KPS) aqueous solution was added, and the temperature was raised to 80 ° C. and kept for 60 minutes.

(Second step) In the presence of the latex obtained in the first step, 0.3 part by weight of a 10% KPS aqueous solution was added, and then 28 parts by weight of butyl acrylate, 5.8 parts by weight of styrene, and 0. 6 parts of a monomer mixture consisting of 8 parts by weight
It was added continuously over 0 minutes and kept for 30 minutes after the addition was completed. (Third step) Next, in the presence of the latex obtained in the second step, 0.4 part by weight of a 10% KPS aqueous solution was added,
A monomer mixture consisting of 39 parts by weight of MMA, 1 part by weight of MA, and 0.07 parts by weight of n-octyl mercaptan was continuously added over 40 minutes, and the mixture was kept for 60 minutes after the addition was completed.
A layer structure polymer latex was obtained (as a result of observation under a scanning microscope, the final particle size was 0.212 μm).

(I) DR-101 (made by Rohm & Haas,
The content of the crosslinked acrylic acid ester-based elastic body is 40% by weight).

(Ultraviolet Absorber) (j) ADEKA SUDAB LA-31 (Asahi Denka Kogyo, benzotriazole ultraviolet absorber)

(Resin Raw Material 1) Resin (e) as methacrylic resin, resin (h) as impact-resistant methacrylic resin, and ultraviolet absorber (j), (e) :( h) :( j) =
100 parts by weight: 25 parts by weight: 0.7 parts by weight, mixed by a tumbler, barrel diameter 50 mm, L / D = 30
The extruder was used to set the temperature of the cylinder at 240 ° C. and pelletize.

(Resin Raw Material 2) Resin (f) as a hard acrylic resin and resin (i) as an impact-resistant methacrylic resin.
And the ultraviolet absorber (j), (f): (i): (j)
= 100 parts by weight: 25 parts by weight: 0.7 parts by weight were mixed in a tumbler, and the cylinder temperature was set to 240 ° C using an extruder with a barrel diameter of 50 mm and a screw L / D = 30. , Pelletized.

(Resin material 3) Resin (g) as a hard acrylic resin, resin (i) as an impact-resistant methacrylic resin
And an ultraviolet absorber (j), (g) :( i) :( j)
= 100 parts by weight: 25 parts by weight: 0.7 parts by weight were mixed in a tumbler, and the cylinder temperature was set to 240 ° C using an extruder with a barrel diameter of 50 mm and a screw L / D = 30. , Pelletized.

(Resin Raw Material 4) The resin (i) and the ultraviolet absorber (j) as impact-resistant methacrylic resin,
(I): (j) = 100 parts by weight: 0.7 parts by weight were mixed together, barrel diameter 50 mm, screw L / D =
Cylinder temperature was set to 240 ° C. and pelletized using 30 extruders.

(Melt viscosity of resin used) Polycarbonate resins (a), (b), (c) used in Examples and Comparative Examples
(D) and acrylic resin (resin raw material 1), (resin raw material 2), (resin raw material 3) for forming the coating layer of the laminated plate,
The melt viscosity of (resin raw material 4) at 250 ° C. and a shear rate of 100 s ⁻¹ was measured. The results obtained are shown in Table 1.

[0037]

[Table 1]

(Manufacturing Process of Laminated Plate) A barrel diameter of 65 is used as an extruder for extruding a polycarbonate resin to be a substrate layer.
mm, screw L / D = 28 was used, and the preset temperature of the cylinder temperature was 260 ° C. As the two extruders for extruding the acrylic resin forming the coating layer, both have a barrel diameter of 50 mm and a screw L / D.
= 30 was used, and the cylinder temperature was set to 250 ° C. A multi-manifold die (width: 1000 mm) is used when two types of resin are melt-extruded and laminated at the same time, and a polycarbonate resin layer is laminated on both sides to form a two-kind three-layer structure. did. The resin laminated and integrated in a die at a temperature of 240 ° C has a temperature of 1
The surface of 10 ℃ is guided to a polishing roll with a mirror finish, and after forming a bank in the roll gap that first flows in, cooling and surface finishing are performed in the process of passing through the mirror roll, and a take-up machine is used for masking. And cut into desired size. The total thickness of the laminate is
Usually, it is determined by the polishing roll gap through which the extruded sheet-shaped molten resin first passes, but in the present invention, the polishing roll gap was adjusted so that the total thickness of the laminate was 2 mm. Further, the thickness ratio of each layer of the laminate is measured by an optical microscope for each layer thickness ratio of the laminate after cooling and solidification, and the extrusion amounts of the two extruders are appropriately adjusted so as to obtain a desired layer ratio. In Examples and Comparative Examples, the coating layer has a thickness of 1
A laminated plate of 00 μm was obtained.

Example 1 A resin (a) was used as the polycarbonate resin for the substrate layer, and (resin raw material 1) was used as the acrylic resin for the coating layer according to the above manufacturing process to produce a laminated plate. Table 2 shows the evaluation results of the obtained laminated plate.
It was shown to.

Example 2 A resin (b) was used as the polycarbonate resin for the substrate layer, and the (resin raw material 2) was used as the acrylic resin for the coating layer according to the above manufacturing process to produce a laminated plate. Table 2 shows the evaluation results of the obtained laminated plate.
It was shown to.

Example 3 Resin (c) was used as the polycarbonate resin for the substrate layer, and (resin raw material 3) was used as the acrylic resin for the coating layer according to the above manufacturing process to produce a laminate. Table 2 shows the evaluation results of the obtained laminated plate.
It was shown to.

Example 4 Resin (d) was used as the polycarbonate resin for the substrate layer, and (resin raw material 4) was used as the acrylic resin for the coating layer according to the above manufacturing process to produce a laminated plate. Table 2 shows the evaluation results of the obtained laminated plate.
Pointing out toungue

(Comparative Example 1) A resin (b) as a polycarbonate resin for a substrate layer and a (resin raw material 1) as an acrylic resin for a coating layer were extruded according to the above manufacturing process to prepare a laminated plate. Table 2 shows the evaluation results of the obtained laminated plate.
It was shown to.

(Comparative Example 2) Resin (c) as the polycarbonate resin for the substrate layer and (resin raw material 2) as the acrylic resin for the coating layer were extruded according to the above manufacturing process to produce a laminated plate. The evaluation results of the obtained laminated plate are shown in Table 2.

(Comparative Example 3) A resin (c) was used as the polycarbonate resin for the substrate layer, and (resin raw material 1) was used as the acrylic resin for the coating layer according to the above manufacturing process to produce a laminated plate. Table 2 shows the evaluation results of the obtained laminated plate.
It was shown to.

[0046]

[Table 2]

[0047]

As described above, since the laminated plate of the present invention is a laminated plate in which a polycarbonate resin substrate layer using a resin having a specific viscosity ratio relationship is coated with an acrylic resin, the polycarbonate resin is Without impairing the inherent impact resistance, excellent weather resistance, transparency, and without causing the interlayer instability phenomenon peculiar to coextrusion molding,
Since it is possible to obtain a laminated board having an excellent appearance and also excellent stability when performing bank forming, it is possible to provide a method capable of manufacturing a laminated board with extremely high productivity.
INDUSTRIAL APPLICABILITY The laminated plate of the present invention can be suitably used in various fields such as various glazing applications, signboards, soundproof walls of automobile roads, front plates of vending machines, carports and the like where weather resistance is required.

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Minoru Ishiyama 2-28 Kurashiki-cho, Nakajo-cho, Kitakanbara-gun, Niigata Prefecture Kuraray Co., Ltd. (56) Reference JP-A-7-223298 (JP, A) JP-A-62 -149411 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B32B 1/00-35/00 B29C 47/00-47/96

Claims (2)

(57) [Claims] 1. A polycarbonate resin layer comprising, on at least one surface thereof, 28 to 94.8% by weight of a methacrylic resin, 5 to 70% by weight of a crosslinked acrylate elastomer and 0.2 to 2% by weight of an ultraviolet absorber. A laminated board having an acrylic resin layer with a thickness of 10 to 150 μm, which comprises 25 parts of a polycarbonate resin (A) and an acrylic resin (B).
Viscosity ratio (A / at a shear rate of 100 s ^-1 at 0 ° C)
B) is 1.9 or more, the laminated board characterized by the above-mentioned. 2. A polycarbonate resin and a resin composition comprising 28 to 94.8% by weight of a methacrylic resin, 5 to 70% by weight of a crosslinked acrylate elastomer and 0.2 to 2% by weight of an ultraviolet absorber. When extrusion-molding, an acrylic resin layer is laminated and integrated on at least one surface of the polycarbonate resin layer, bank molding is performed with a molding roll, and an acrylic resin layer having a thickness of 50 to 150 μm is provided on the polycarbonate resin layer. A laminate having a viscosity ratio (A / B) of the polycarbonate resin (A) and the acrylic resin (B) at a shear rate of 100 s ⁻¹ at 100 ° C. of 1.9 or more. Production method.