KR102037532B1 - Thermoplastic resin extruded plate - Google Patents

Abstract

assignment
It is to provide a thermoplastic resin extruded plate capable of suppressing warpage deformation under a high temperature and high humidity environment.
Resolution
The thermoplastic resin in the molten state extruded from the die is sandwiched between the first cooling roll and the second cooling roll, hooked onto the second cooling roll, and then to at least one rear end cooling roll formed subsequent to the second cooling roll. A thermoplastic resin extruded plate obtained by rolling and cooling, the other surface opposite to the one surface in contact with the outer peripheral surface of the second cooling roll is curved, the center of curvature is located on the other surface side, and the bending direction is in the extrusion direction and the extrusion direction. It coincides with at least one of the directions orthogonal to each other, and the radius of curvature of the thermoplastic resin extruded plate is 10 to 200 m.

Description

Thermoplastic Extruded Plate {THERMOPLASTIC RESIN EXTRUDED PLATE}

The present invention relates to a thermoplastic resin extruded plate which is not easily warped.

The thermoplastic resin extruded plate (hereinafter may be referred to as "extruded plate") is excellent in continuous productivity, plate thickness accuracy, etc., and therefore is made of various resins in various fields such as home appliances, automobiles, building materials, and electronic devices. Is used.

On the other hand, the extruded plate has a problem that it is easy to bend and deform when used in a harsh environment such as high temperature or high humidity. This problem is remarkable in electronic device related applications, such as a light guide plate, a diffusion plate, a touch panel board | substrate, and a liquid crystal display protection plate used in the environment of high temperature, high humidity. Therefore, the attempt to suppress the bending deformation of the resin plate which generate | occur | produces in a use environment is made.

Patent Literature 1 discloses a resin laminated plate obtained by laminating a resin layer containing a methyl methacrylate unit and a styrene monomer unit at a predetermined ratio, and a resin layer containing a methyl methacrylate unit and a ultraviolet absorber at a predetermined ratio. It is described. According to patent document 1, it is described that this resin laminated board does not produce the deformation | transformation by absorption well, and is excellent also in weather resistance.

However, in patent document 1, until the suppression of the bending deformation in the high temperature, high humidity environment of the said resin laminated board is not examined.

Patent Literature 2 describes at least one surface of a transparent thermoplastic resin sheet coated with a cured resin layer via an adhesive layer, and a transparent thermoplastic resin composite sheet having birefringence values in the thickness direction and in plane in a predetermined range. According to patent document 2, it is described that the said composite sheet does not generate | occur | produce flexural deformation well in a use environment.

However, when the birefringence value decreases, the internal strain decreases and tends to be difficult to bend. However, even when the birefringence value is small, bending deformation is often generated depending on the use environment. Therefore, in the said composite sheet described in patent document 2, suppression of curvature distortion was inadequate.

Japanese Unexamined Patent Publication No. 2004-9524 Japanese Laid-Open Patent Publication 2005-193514

The subject of this invention is providing the thermoplastic resin extruded board which can suppress the bending deformation in high temperature, high humidity environment.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to solve the said subject, the present inventors discovered the solution which consists of the following structures, and came to complete this invention.

(1) The thermoplastic resin in the molten state extruded from the die is sandwiched between the first cooling roll and the second cooling roll, and walked on the second cooling roll, and then at least one rear end formed subsequent to the second cooling roll. A thermoplastic resin extruded plate obtained by rolling on a cooling roll to be cooled, wherein the other surface opposite to the one surface in contact with the outer circumferential surface of the second cooling roll is curved, the center of curvature is located on the other surface side, and the bending direction is the extrusion direction and the It coincides with at least one of the directions orthogonal to an extrusion direction, and the curvature radius of a thermoplastic resin extruded plate is 10-200 m, The thermoplastic resin extruded plate characterized by the above-mentioned.

(2) Said thermoplastic resin is at least 1 sort (s) chosen from the group which consists of methyl methacrylate type resin, aromatic polycarbonate resin, styrene resin, and resin containing an alicyclic structure containing ethylenic unsaturated monomeric unit (1) The thermoplastic resin extruded plate of description.

(3) The thermoplastic resin is formed by laminating at least two kinds of thermoplastic resins, and each of the thermoplastic resins to be laminated is a methyl methacrylate resin, an aromatic polycarbonate resin, a styrene resin, and an alicyclic structure-containing ethylenic unsaturated resin. The thermoplastic resin extruded board as described in said (1) or (2) which is at least 1 sort (s) chosen from the group which consists of resin containing a monomeric unit.

(4) The thermoplastic resin extruded plate according to any of the above (1) to (3), wherein the thermoplastic resin extruded plate has a thickness of 0.3 to 5 mm.

(5) The thermoplastic resin extruded plate as described in any one of said (1)-(4) used for a light guide plate.

(6) The thermoplastic resin extruded plate in any one of said (1)-(4) used for a touch panel board | substrate.

(7) The thermoplastic resin extruded plate in any one of said (1)-(4) used for a liquid crystal display protection plate.

The thermoplastic resin extruded plate of the present invention is not easily warped under a high temperature and high humidity environment, and therefore, the thermoplastic resin extruded plate can be suitably used for a light guide plate, a touch panel substrate, a liquid crystal display protective plate, or the like placed under a high temperature and high humidity environment.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic explanatory drawing which shows the manufacturing method of the thermoplastic resin extruded board which concerns on one Embodiment of this invention.
FIG. 2 is a partially enlarged schematic explanatory diagram of FIG. 1.
FIG.3 (a), (b) is schematic explanatory drawing which shows the thermoplastic resin extruded board which concerns on one Embodiment of this invention.

The thermoplastic resin extruded plate of this invention consists of a thermoplastic resin. The thermoplastic resin is not particularly limited as long as it is a resin that can be melt-processed, and for example, polyvinyl chloride resin, acrylonitrile-butadiene-styrene resin, low density polyethylene resin, high density polyethylene resin, linear low density polyethylene resin, polystyrene resin, Polypropylene resin, acrylonitrile-styrene resin, cellulose acetate resin, ethylene-vinylacetate resin, acryl-acrylonitrile-styrene resin, acrylic-chlorinated polyethylene resin, ethylene-vinyl alcohol resin, fluorine resin, methyl methacrylate resin , Methyl methacrylate-styrene resin, polyacetal resin, polyamide resin, polyethylene terephthalate resin, aromatic polycarbonate resin, polysulfone resin, polyether sulfone resin, methylpentene resin, polyallylate resin, polybutylene terephthalate Resin, alicyclic structure containing ethylenic In addition to general-purpose or engineering plastics such as resins containing saturated monomeric units, polyphenylene sulfide resins, polyphenylene oxide resins, and polyether ether ketone resins, polyvinyl chloride-based elastomers, chlorinated polyethylene, ethylene-ethyl acrylate resins, and thermoplastic poly Rubber-like polymers such as urethane elastomers, thermoplastic polyester elastomers, ionomer resins, styrene-butadiene block polymers, ethylene-propylene rubbers, polybutadiene resins, acrylic rubbers, and the like, and may be used. You may mix and use the above.

Among these, at least 1 type chosen from methyl methacrylate type resin, aromatic polycarbonate resin, styrene resin, and resin containing an alicyclic structure containing ethylenically unsaturated monomeric unit is preferable at the point which an optical characteristic is favorable. In addition, the thermoplastic resin may be formed by laminating at least two kinds of thermoplastic resins. That is, the extruded plate of the present invention may be melt-kneaded and coextruded from two or more kinds of thermoplastic resins respectively using two or more extruders to form a laminated structure having two or more layers of thermoplastic resin layers. In this case, the thermoplastic resin which comprises each laminated thermoplastic resin layer is at least chosen from resin containing methyl methacrylate type resin, aromatic polycarbonate resin, styrene resin, and alicyclic structure containing ethylenically unsaturated monomeric unit. It is preferable that it is 1 type.

Methyl methacrylate resin is a polymer containing 50 weight% or more of methyl methacrylate units as a monomeric unit. Content of the methyl methacrylate unit becomes like this. Preferably it is 70 weight% or more, and 100 weight% may be sufficient. The polymer whose methyl methacrylate unit is 100 weight% is a methyl methacrylate homopolymer obtained by superposing | polymerizing methyl methacrylate independently.

The methyl methacrylate resin may be a copolymer of methyl methacrylate and another monomer copolymerizable with the methyl methacrylate. As another monomer copolymerizable with methyl methacrylate, methacrylic acid esters other than methyl methacrylate etc. are mentioned, for example. As such methacrylic acid ester, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, methacrylic acid 2, for example -Hydroxyethyl, etc. are mentioned. Moreover, acrylic acid esters, such as methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, and 2-hydroxyethyl acrylate, unsaturated acids, such as methacrylic acid and acrylic acid, chloro Substituted styrenes such as halogenated styrenes such as styrene and bromostyrene, alkyl styrenes such as vinyltoluene and α-methylstyrene, acrylonitrile, methacrylonitrile, maleic anhydride, phenylmaleimide and cyclohexylmalee Mead etc. are mentioned. These monomers may be used independently, respectively and may be used in combination of 2 or more type.

In addition, the methyl methacrylate resin may be a resin composition by adding a rubber polymer. Thereby, since it hardly cracks at the time of shaping | molding, a yield can be improved. As a rubber-like polymer, the graft copolymer etc. which graft-polymerized the ethylenically unsaturated monomer in the ratio of 95-20 weight part to the acryl-type multilayer structure polymer, and 5 to 80 weight part rubber-like polymer are mentioned, for example.

As an acryl-type multilayered structure polymer, what has a layer of rubber elasticity or the layer of elastomer in 20 to 60 weight part, for example, and has a hard layer in the outermost part, A hard layer is further added as an innermost layer. You may have it.

The layer of rubber elasticity or the layer of elastomer is a layer of acrylic polymer having a glass transition point (Tg) of less than 25 ° C. For example, lower alkyl acrylate and methacrylate, lower alkoxy acrylate, cyanoethyl acrylate, acrylic It consists of the polymer which bridge | crosslinked 1 or more types of monoethylenically unsaturated monomers, such as an amide, hydroxy lower alkylacrylate, hydroxy lower methacrylate, acrylic acid, and methacrylic acid, with allyl methacrylate, a polyfunctional monomer, etc.

The hard layer is a layer of an acrylic polymer having a Tg of 25 ° C. or more, wherein alkyl methacrylate having a C 1-4 alkyl group is used alone or as a main component, and other alkyl methacrylates, alkyl acrylates, styrenes, substituted styrenes, and acrylics. It may consist of polymers of copolymerizable monofunctional monomers, such as ronitrile and methacrylonitrile, and may be a crosslinked polymer further polymerized by adding a polyfunctional monomer. As the above-mentioned rubbery polymer, those described in JP-A-55-27576, JP-A-6-80739, JP-A-49-23292 and the like can be used.

In the graft copolymer obtained by graft polymerization of an ethylenically unsaturated monomer at a ratio of 95 to 20 parts by weight with a rubber polymer of 5 to 80 parts by weight, as the rubber polymer, for example, polybutadiene rubber, acrylonitrile / butadiene air Diene rubber such as copolymer rubber, styrene / butadiene copolymer rubber, acrylic rubber such as polybutyl acrylate, polypropyl acrylate, poly-2-ethylhexyl acrylate, and ethylene / propylene / non-conjugated diene rubber Can be mentioned. Moreover, as said ethylenic monomer, styrene, acrylonitrile, alkyl (meth) acrylate, etc. are mentioned, for example, An acryl-type unsaturated monomer is preferable, These may be used 1 type or in mixture of 2 or more types. . As the graft copolymer described above, for example, those described in JP-A-55-147514, JP-A-47-9740 and the like can be used.

It is preferable that it is 0-100 weight part with respect to 100 weight part of methyl methacrylate type resin, and, as for the addition amount of a rubbery polymer, it is more preferable that it is 3-50 weight part. When the addition amount of the rubbery polymer is too large, the rigidity of the extruded plate is lowered, which is not preferable.

As aromatic polycarbonate resin, what is obtained by making bivalent phenol and a carbonate precursor react by the interfacial polycondensation method, the melt transesterification method, the thing which superposed | polymerized the carbonate prepolymer by the solid-phase transesterification method, or the ring-opening polymerization method of the cyclic carbonate compound The thing obtained by superposing | polymerizing by these is mentioned.

Examples of the dihydric phenol include hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane, bis {(4-hydroxy-3,5-dimethyl ) Phenyl} methane, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 2,2-bis (4-hydroxyphenyl) propane (Common name bisphenol A), 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2-bis {(4-hydroxy-3,5-dimethyl) phenyl} propane, 2, 2-bis {(4-hydroxy-3,5-dibromo) phenyl} propane, 2,2-bis {(3-isopropyl-4-hydroxy) phenyl} propane, 2,2-bis {( 4-hydroxy-3-phenyl) phenyl} propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) -3-methylbutane, 2,2-bis (4-hydroxyphenyl) -3,3-dimethylbutane, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 2,2-bis (4-hydroxyphenyl) pentane, 2,2 -Bis (4-hydroxyphenyl) -4-methylpentane, 1,1-bis (4-hydroxy Yl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -4-isopropylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 9, 9-bis (4-hydroxyphenyl) fluorene, 9,9-bis {(4-hydroxy-3-methyl) phenyl} fluorene, α, α'-bis (4-hydroxyphenyl) -o- Diisopropylbenzene, α, α'-bis (4-hydroxyphenyl) -m-diisopropylbenzene, α, α'-bis (4-hydroxyphenyl) -p-diisopropylbenzene, 1,3 -Bis (4-hydroxyphenyl) -5,7-dimethyladamantane, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfoxide, 4,4'-di Hydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ester, and the like, and these may be used alone. Or you may mix and use 2 or more types.

Among them, bisphenol A, 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl ) -3-methylbutane, 2,2-bis (4-hydroxyphenyl) -3,3-dimethylbutane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 1,1-bis Obtained from at least one bisphenol selected from the group consisting of (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and α, α'-bis (4-hydroxyphenyl) -m-diisopropylbenzene Homopolymers or copolymers are preferred, and in particular, homopolymers of bisphenol A, and 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and bisphenol A, 2,2-bis { Preferred is a copolymer with (4-hydroxy-3-methyl) phenyl} propane and at least one divalent phenol selected from α, α'-bis (4-hydroxyphenyl) -m-diisopropylbenzene. Do.

As a carbonate precursor, carbonyl halide, carbonate ester, haloformate, etc. are used, for example, phosgene, diphenyl carbonate, dihaloformate of dihydric phenol, etc. are mentioned.

A styrene resin is a polymer which has a styrene monofunctional monomeric unit as a main component, and is a polymer containing 50 weight% or more of styrene-based monofunctional monomeric units specifically ,. The styrene resin may be a homopolymer of a styrene monofunctional monomer, or may be a copolymer of a styrene monofunctional monomer and a monofunctional monomer copolymerizable with this.

As a styrene-type monofunctional monomer, a substituted styrene etc. are mentioned besides styrene, for example. As substituted styrene, halogenated styrenes, such as chloro styrene and bromostyrene, alkyl styrenes, such as vinyltoluene and (alpha) -methylstyrene, etc. are mentioned, for example. That is, a styrenic monofunctional monomer is a compound which has a styrene skeleton and has one double bond which can be radically polymerized in a molecule | numerator.

A monofunctional monomer copolymerizable with a styrene monofunctional monomer is a compound having one double bond capable of radical polymerization in a molecule and copolymerizable with a styrene monofunctional monomer in this double bond, for example, methyl methacrylate or methacrylic. Methacrylic acid esters, such as ethyl acid, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-etherhexyl methacrylate, and 2-hydroxyethyl methacrylate, methyl acrylate And acrylic acid esters such as ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate, acrylonitrile, and the like. Methacrylic acid ester is used preferably, Each is used individually or in combination of 2 or more types.

The styrene resin may be a resin composition by adding a rubber polymer. As a rubber polymer, the thing similar to the rubber polymer which can be added to the methyl methacrylate type resin mentioned above can be used. It is preferable that it is 0-100 weight part with respect to 100 weight part of styrene resin, and, as for the addition amount of a rubber polymer, it is more preferable that it is 3-50 weight part. When the addition amount of the rubbery polymer is too large, the rigidity of the extruded plate is lowered, which is not preferable.

As resin containing an alicyclic structure containing ethylenically unsaturated monomeric unit, a norbornene-type polymer, a vinyl alicyclic hydrocarbon type polymer, etc. are mentioned, for example. The said resin is characterized by containing an alicyclic structure in the repeating unit of a polymer. Although the alicyclic structure may have either a main chain and / or a side chain, it is preferable to contain an alicyclic structure in a main chain from a light transmittance viewpoint.

As a specific example of resin containing an alicyclic structure containing ethylenically unsaturated monomeric unit, a norbornene type polymer, a monocyclic cyclic olefin type polymer, a cyclic conjugated diene type polymer, a vinyl alicyclic hydrocarbon type polymer, and these hydrogenated substances Etc. can be mentioned. Among them, from the viewpoint of light transmittance, norbornene-based polymer hydrides, vinyl alicyclic hydrocarbon-based polymers or hydrides thereof are preferable, and norbornene-based polymer hydrides are more preferable.

Moreover, you may add a light diffusing agent, a gloss remover, a ultraviolet absorber, surfactant, an impact resistant agent, a polymeric antistatic agent, antioxidant, a flame retardant, a lubricating agent, a dye, a pigment, etc. to a thermoplastic resin according to the objective, for example.

The thermoplastic resin extruded plate of the present invention made of the thermoplastic resin described above can be produced by an extrusion molding method. EMBODIMENT OF THE INVENTION Hereinafter, one Embodiment of the manufacturing method of the thermoplastic resin extruded board which concerns on this invention is described in detail with reference to FIGS.

As shown in FIG. 1, first, the above-mentioned thermoplastic resin is melt-kneaded with the extruder 1 and / or the extruder 2, and the thermoplastic resin (henceforth a "molten thermoplastic resin") 4 in a molten state is called (4). Extruded into a plate shape from the die (3). In the case where the extruded plate has a laminated structure, it can be produced by a coextrusion molding method. That is, the thermoplastic resin is melt-kneaded by the extruder 1 and supplied to the die 3, the other thermoplastic resin is melt-kneaded by the extruder 2 and supplied to the die 3, and each is coextruded from the die 3, What is necessary is just to laminate | stack and integrate.

As the extruder 1, 2, a single screw extruder, a twin screw extruder, etc. are mentioned, for example. In addition, the number of extruders is not limited to two, You may use three or more pieces. As the die 3, a T die is usually used, and in addition to the single-layer die for extruding the thermoplastic resin in a single layer, two or more kinds of thermoplastic resins independently fed from the extruders 1 and 2, such as a feed block die and a multi-manifold die, etc. The multilayer die etc. which laminate | stack and co-extrude may be employ | adopted.

The molten thermoplastic resin 4 extruded from the die 3 is molded and cooled by the cooling unit 5. The cooling unit 5 is comprised from three cooling rolls arrange | positioned substantially in the horizontal direction. The three cooling rolls consist of the 1st cooling roll 6, the 2nd cooling roll 7, and the rear stage cooling roll 8 which were arrange | positioned one by one along the direction which takes out the molten thermoplastic resin 4 shown by arrow A. FIG. At least one roll of these cooling rolls 6-8 is connected to rotation drive means, such as a motor, and is comprised so that each roll may rotate at predetermined | prescribed main speed.

It does not specifically limit as cooling rolls 6-8, The conventional cooling roll conventionally used by extrusion molding can be employ | adopted. As a specific example, a drill roll, a spiral roll, a metal elastic roll, a rubber roll, etc. are mentioned. The surface state of the cooling rolls 6 to 8 may be, for example, a mirror surface, or may have a shape, irregularities, and the like.

Molding and cooling by the cooling unit 5 insert the molten thermoplastic resin 4 between the 1st cooling roll 6 and the 2nd cooling roll 7, as shown in FIG. 2, and a 2nd cooling roll. After walking to (7), it is implemented by walking to the rear | end stage cooling roll 8, and is taken out by the take-out roll which is not shown in figure, and the thermoplastic resin extruded board 10 is obtained after that.

As for the extrusion plate 10, the other surface 10b opposite to the one surface 10a which contacted the outer peripheral surface 7a of the 2nd cooling roll 7 wound first is curved as shown in FIG. Specifically, the extruded plate 10 is curved so that the other surface 10b satisfies the following (i) to (i).

(Iii) The center of curvature is located on the other surface 10b side. That is, the extruded plate 10 is curved so as to be concave with the other surface 10b side up.

(Ii) The curved direction is a direction perpendicular to the extrusion direction shown in FIG. 3 (a) (hereinafter may be referred to as “MD”) and the extrusion direction shown in FIG. 3 (b) (hereinafter, referred to as “TD”). May be at least one direction.

(Iii) The radius of curvature is 10 to 200 m, preferably 15 to 180 m, more preferably 20 to 150 m.

That is, specific warping is provided to the extruded plate 10 so that the other surface 10b is curved to satisfy the above (i) to (v). Thereby, the bending deformation of the extruded plate in high temperature, high humidity environment can be suppressed. For this reason, the following reasons are inferred.

In the process of shape | molding and cooling the molten thermoplastic resin 4 by the cooling unit 5, internal stress generally accumulates easily. When the molten thermoplastic resin 4 is molded and cooled so that the specific warpage described above is imparted to the extruded plate 10, the internal stress is hardly accumulated, and the extruded plate 10 thus obtained has a high temperature and high humidity environment. It is inferred that the bending deformation is not good. In particular, in the above (iv), if the radius of curvature is less than 10 m, the warpage provided in advance is too large, adversely affecting the assembling process, and when it exceeds 200 m, the effect of suppressing warpage deformation is reduced. In addition, said "high temperature, high humidity environment" means the environment whose temperature is 30 degreeC or more and humidity is 70% or more, For example, to the environment whose temperature is 60 degreeC or more and humidity is 95% or more, or about 80 degreeC hot water, The environment etc. to immerse for about 1 hour are mentioned.

As a method of imparting warping as described above, a heater is mounted below the second cooling roll 7 or above the rear stage cooling roll 8 to heat the molten thermoplastic resin 4, or the cooling rolls 6 to 6. And a method of adjusting the surface temperature of 8) to achieve a desired warpage. Generally, when the surface temperature of the 2nd cooling roll 7 is lowered, there exists a tendency for the curvature along the outer peripheral surface of the 2nd cooling roll 7 to become strong. Moreover, when the surface temperature of the rear stage cooling roll 8 is lowered, there exists a tendency for the curvature along the outer peripheral surface of the rear stage cooling roll 8 to become strong.

On the other hand, when shaping | molding the molten thermoplastic resin 4 between the cooling rolls 6-8, respectively, it is necessary to sandwich between the rolls in the process before cooling-solidification of the molten thermoplastic resin 4, or cooling solidification. .

Tr

(Th + 20 ℃), 바람직하게는 (Th - 15 ℃)

Tr

(Th + 10 ℃), 보다 바람직하게는 (Th - 10 ℃)

Tr

(Th + 5 ℃) 의 범위로 하는 것이 바람직하다. 표면 온도 (Tr) 이 (Th - 20 ℃) 보다 낮은 온도가 되면, 롤로부터 수지가 박리되기 쉬워지고, 터치 미스가 발생하기 쉬워지기 때문에 바람직하지 않다. 또, 표면 온도 (Tr) 이 (Th + 20 ℃) 보다 높은 온도가 되면, 롤로부터 수지가 균일하게 잘 박리되게 않게 되고, 터치 마크라고 불리는 롤 박리시의 충격에 의한 폭방향의 선이 발생하기 쉬워지기 때문에 바람직하지 않다.Specifically, the surface temperature (Tr) of the cooling rolls 6 to 8 is (Th-20 ° C) with respect to the heat deformation temperature (Th) of the thermoplastic resin.

Tr

(Th + 20 ° C), preferably (Th-15 ° C)

Tr

(Th + 10 ° C), more preferably (Th-10 ° C)

Tr

It is preferable to set it as the range of (Th + 5 degreeC). When surface temperature Tr becomes temperature lower than (Th-20 degreeC), since resin will peel easily from a roll and a touch miss will arise easily, it is unpreferable. Moreover, when surface temperature Tr becomes temperature higher than (Th + 20 degreeC), resin will not peel easily from a roll uniformly, and the line of the width direction by the impact at the time of roll peeling called a touch mark will generate | occur | produce. It is not preferable because it becomes easy.

In addition, it is although it does not specifically limit as heat distortion temperature Th of the said thermoplastic resin, Usually, it is about 60-200 degreeC. The heat distortion temperature (Th) of a thermoplastic resin is the temperature measured based on ASTMD-648. Moreover, about the surface temperature (Tr) when the extrusion plate is co-extruded from 2 or more types of different thermoplastic resins, and it is set as a laminated structure, the thermoplastic resin with the highest heat distortion temperature Th is the reference | standard among 2 or more types of different thermoplastic resins. It is done.

As thickness of the extruded board 10, it is preferable that it is 0.3-5 mm, It is more preferable that it is 0.5-3 mm, It is further more preferable that it is 0.6-2 mm. If the thickness of the extruded plate 10 is too thick or too thin, there is a tendency that the control of warping becomes difficult. In addition, the obtained extruded plate 10 may be provided with a cured film or its antireflection treatment on its surface as necessary.

The thermoplastic resin extruded plate of the present invention thus obtained has a small warpage deformation under a high temperature, high humidity environment, and therefore can be used for various applications, and among them, it is preferably used as a light guide plate, a touch panel substrate, or a liquid crystal display protective plate. As the use of such a touch panel or liquid crystal display, for example, a monitor of a television or a computer, a display window of a portable information terminal such as a mobile phone or a personal handy-phone system (PHS), a personal digital assistant (PDA), a digital camera or a handy type The finder part of a video camera, the display window of a portable game machine, etc. are mentioned.

In order to produce a light guide plate from the thermoplastic resin extruded board of the present invention, the extruded plate may be cut to a required size. In addition, in order to produce a touch panel board | substrate and a display protection plate, you may process printing, punching, etc. to an extruded plate as needed first, and then cut an extruded plate to a required size. Then, when the extruded plate is set on the display, it can be suitably used as a touch panel substrate or a display protective plate. In that case, it is preferable to set so that the extruded plate may contact the outer peripheral surface of a 2nd cooling roll with the front side (viewer side) among the both surfaces.

As mentioned above, although preferred embodiment which concerns on this invention was described, this invention is not limited to the above embodiment, A various improvement and a change are possible in the range described in a claim. For example, in one embodiment mentioned above, although the number of cooling rolls is three, it is good also as four or more. That is, the number of the rear stage cooling rolls is not limited to one, but may be two or more. When making a plurality of rear stage cooling rolls, about 2-4 are suitable for the number normally. Moreover, it is not necessary to unify all the types of cooling rolls in the same thing.

Example

Hereinafter, although an Example is given and this invention is demonstrated in more detail, this invention is not limited to a following example.

The structure of the extrusion apparatus used by the following example and the comparative example is as follows.

Extruder (1): The extruder (made by Hitachi Shipbuilding Co., Ltd.) with a screw diameter of 100 mm, a single shaft, and the vent was used.

Extruder (2): An extruder (manufactured by Hitachi Shipbuilding Co., Ltd.) with a screw diameter of 35 mm, a single shaft, and a vent was used.

Feed block: The feed block for 2 type 2 layers distribution, and the feed block for 2 type 3 layers distribution (made by Hitachi Shipbuilding Co., Ltd.) were used.

Die 3: T-die (made by Hitachi Shipbuilding Co., Ltd.) of lip width 1500mm and lip spacing 1mm was used.

Cooling unit 5: The cooling rolls 6-8 of horizontal type, surface length 1600mm, and diameter 300mmphi were used. Cooling rolls 6-8 are as follows.

1st cooling roll 6: The metal elastic roll mentioned later was used.

2nd cooling roll 7: The stainless steel spiral roll which made the surface state the mirror surface was used.

Rear stage cooling roll 8: The metal elastic roll mentioned later was used.

As the metal elastic rolls used for the cooling rolls 6 and 8, the metal thin film was arrange | positioned so that the outer peripheral surface of the shaft roll might be covered, and the metal elastic roll which enclosed the fluid between the shaft roll and the metal thin film was used. A shaft roll, a metal thin film, and a fluid are as follows.

Shaft roll: The thing made of stainless steel was used.

Metal thin film: The mirror metal sleeve made of stainless steel of thickness 2mm was used.

Fluid: Oil was used. Moreover, temperature control of this oil made the metal elastic roll temperature controllable. More specifically, the oil was heated, cooled and temperature controlled by ON-OFF control of the temperature controller, and circulated between the shaft roll and the metal thin film.

The thermoplastic resin used by the following example and the comparative example is as follows.

Resin 1: The polymer ("Caliber 301-10" by Sumitomo Dow Co., Ltd. only) of aromatic polycarbonate was used. Heat distortion temperature Th is 140 degreeC.

Resin 2: A copolymer of methyl methacrylate / methyl acrylate = 98/2 (weight ratio) was used. Heat distortion temperature Th is 100 degreeC.

Resin 3: An acrylic resin composition containing 30% by weight of an acrylic multilayer structure polymer (rubber polymer) obtained in the following Reference Example was used in a 70% by weight copolymer of methyl methacrylate / methyl acrylate = 96/4 (weight ratio). . Heat distortion temperature Th is 100 degreeC.

[Reference Example]

(Preparation of acrylic multilayer structure polymer)

Based on the method of the Example of Unexamined-Japanese-Patent No. 55-27576, the acryl-type multilayered polymer which consists of a three-layered structure was manufactured. Specifically, first, 1700 g of ion-exchanged water, 0.7 g of sodium carbonate, and 0.3 g of sodium persulfate were injected into a 5 L glass reaction vessel. Subsequently, after stirring under nitrogen stream, 4.46 g of Plex OT-P (manufactured by Cao), 150 g of ion-exchanged water, 150 g of methyl methacrylate, and 0.3 g of allyl methacrylate were further injected. Then, it heated up at 75 degreeC and continued stirring for 150 minutes.

Then a mixture of 689 g of butyl acrylate, 162 g of styrene, 17 g of allyl methacrylate, 0.85 g of sodium persulfate, 7.4 g of PLEX OT-P and 50 g of ion exchanged water was added over 90 minutes from the other inlet. Then, polymerization was continued for 90 minutes.

After the completion of the polymerization, a mixture of 326 g of methyl acrylate, 14 g of ethyl acrylate and 30 g of ion-exchanged water in which 0.34 g of sodium persulfate was dissolved was added over 30 minutes from different inlets.

After the addition was completed, the mixture was held for 60 minutes to complete the polymerization to obtain a latex. The obtained latex was poured into a 0.5% aqueous aluminum chloride solution to coagulate the polymer. This was washed 5 times with warm water, and dried to obtain an acrylic multilayer structure polymer.

[Examples 1, 3, 4 and Comparative Examples 1, 3]

<Production of Thermoplastic Extruded Plate>

First, the extruder 1, 2, the die 3, and the cooling rolls 6-8 were arrange | positioned as shown in FIG. 1, and the feed block was arrange | positioned at the predetermined position. Next, as a resin layer (A), resin of the kind shown in Table 1 was melt-kneaded with the extruder 1, and it supplied to the feed block. On the other hand, as a resin layer (B), resin of the kind shown in Table 1 was melt-kneaded with the extruder 2, and it supplied to the feed block. It co-extruded from the die 3 so that the resin layer B supplied to the feed block from the extruder 2 may be laminated | stacked on both surfaces of the resin layer A supplied to the feed block from the extruder 1.

The molten thermoplastic resin 4 co-extruded from the die 3 is passed through the cooling rolls 6 to 8 at the surface temperature shown in Table 1 to be molded and cooled, and the thermoplastic having a three-layer configuration having a thickness shown in Table 1 A resin extruded plate was obtained. In addition, the temperature of the cooling rolls 6-8 in Table 1 is the value which actually measured the surface temperature of the cooling rolls 6-8.

Moreover, "thickness" in the extruders 1 and 2 of Table 1 has shown each thickness of resin layer (A, B). More specifically, the value described in the "thickness" column in the extruder 2 has shown "one surface layer thickness / the other surface layer thickness". "Total thickness" in Table 1 has shown the total thickness of the obtained extruded board.

Moreover, about Example 1 and the comparative example 1, the heater was installed under the 2nd cooling roll 7, and the temperature of the heater was made into the temperature shown in Table 1.

Example 2 and Comparative Example 2

Coextruded from the die 3 on one side of the resin layer A supplied to the feed block from the extruder 1 so that the resin layer B supplied to the feed block from the extruder 2 is laminated, and the resin layer B ) Was coextruded in the same manner as in Examples 1, 3, and 4, except that the surface of the sheet was in contact with the second cooling roll 7.

And the molten thermoplastic resin 4 coextruded from the die 3 is made to pass through the cooling rolls 6-8 of the surface temperature shown in Table 1, shaping | molding and cooling, and the 2-layered constitution of the thickness shown in Table 1 The thermoplastic resin extruded plate was obtained. Moreover, the same heater as Example 1 was installed below the 2nd cooling roll 7, and the temperature of the heater was made into the temperature shown in Table 1.

Example 5 and Comparative Example 4

Extrusion was carried out in the same manner as in Examples 1, 3 and 4, except that the resin of the kind shown in Table 1 was melt kneaded with the extruder 1 and fed in the order of the feed block and the die 3. And the molten thermoplastic resin 4 extruded from the die 3 is made to pass through between the cooling rolls 6-8 of the surface temperature shown in Table 1, shaping | molding and cooling, and the thermoplastic of the single layer structure of the thickness shown in Table 1 A resin extruded plate was obtained. In addition, about Example 5, the heater similar to Example 1 was provided below the 2nd cooling roll 7, and the temperature of the heater was made into the temperature shown in Table 1.

<Evaluation>

About each obtained extruded board (Examples 1-5 and Comparative Examples 1-4), the curvature amount, the curvature direction, the curvature radius, the warm water immersion curvature amount, and the moving amount were evaluated. While each evaluation method is shown below, the result is shown in Table 1. FIG.

(Bending amount, bending direction, curvature radius)

First, three pieces of test pieces were cut out from the obtained extruded plate along the direction TD orthogonal to the extrusion direction MD. The shape of each test piece was 400 mm in MD, and 275 mm in TD.

Subsequently, each test piece was put on the surface plate, and the floating amount of four angles of each test piece was measured using the gap gauge. And the average value of all the floating amounts in each test piece was computed, and this was made into the curvature amount. At this time, if the surface on which the angle to be measured rises is the other surface opposite to the one surface in contact with the outer circumferential surface of the second cooling roll 7, it is "+", and if it is the one surface in contact with the outer circumferential surface of the second cooling roll 7, "-". It evaluated as.

Moreover, the radius of curvature was computed from the obtained curvature amount and the test piece length of the direction in which the test piece is bent. Moreover, if a curved direction is MD, a test piece length is 400 mm, and if a curved direction is TD, a test piece length is 275 mm.

(Hot water immersion warpage amount and movement amount)

First, three test pieces used for the measurement of the amount of warpage were immersed in warm water at 80 ° C. for 1 hour, and then cooled by immersion in cold water for 1 minute. Subsequently, each test piece was placed on the surface plate, and the four-floating angle of each test piece was measured using the gap gauge.

And the average value of all the floating amount in each test piece was computed, and this was made into the warm water immersion curvature amount. At this time, similar to the amount of warpage, if the surface on which the angle to be measured rises is the other surface opposite to the one surface that is in contact with the outer circumferential surface of the second cooling roll 7, one side that is in contact with the outer circumferential surface of the second cooling roll 7 is +. It evaluated as "-" on the back.

In addition, the amount of movement was calculated from the formula: (hot water immersion warpage amount)-(warpage amount). In addition, in the comparative examples 1, 2, and 4, the surface where the square of the test piece floats changed as follows before and after immersion in warm water.

Before dipping hot water: One side in contact with the outer circumferential surface of the second cooling roll 7

After immersion in hot water: the other side of the other side

For this reason, about the comparative examples 1, 2, and 4, the moving amount was computed from Formula: (hot water immersion deflection amount) + (warpage amount).

As can be seen from Table 1, Examples 1-5 showed the result that the value of the warm water immersion curvature amount was small, and the value of the movement amount was also small. From this result, it turns out that Examples 1-5 are hard to bend deform | transform under high temperature, high humidity environment. On the other hand, the comparative example 3 and the one side in which the one side which contacted the outer peripheral surface of the 2nd cooling roll 7 were curved, and the center of curvature is located in the one side side, and the curvature radius exceed 200 m, In Comparative Example 4 in which the curvature center was curved and the curvature center was located on one side, and the radius of curvature exceeded 200 m, the value of the warm water immersion deflection amount was large and the value of the shift amount was also large.

1, 2 extruders
3 die
4 molten thermoplastic
5 cooling units
6 first cooling roll
7 second cooling roll
7a outer surface
8 rear end cooling roll
10 thermoplastic extrusion plate
1Oa one side
1Ob ride

Claims (7)

The thermoplastic resin in the molten state extruded from the die is sandwiched between the first cooling roll and the second cooling roll, hooked onto the second cooling roll, and then to at least one rear end cooling roll formed subsequent to the second cooling roll. As a thermoplastic resin extruded plate obtained by rolling and cooling,
The other surface opposite to the one surface which contact | connected the outer peripheral surface of the said 2nd cooling roll is curved, The center of curvature is located in the said other surface side,
The curved direction coincides with at least one of the extrusion direction and the direction orthogonal to the extrusion direction,
The curvature radius of a thermoplastic resin extruded plate is 10-200 m, and the said thermoplastic resin extruded plate is for a touch panel board | substrate, The thermoplastic resin extruded board characterized by the above-mentioned. The thermoplastic resin in the molten state extruded from the die is sandwiched between the first cooling roll and the second cooling roll, hooked onto the second cooling roll, and then to at least one rear end cooling roll formed subsequent to the second cooling roll. As a thermoplastic resin extruded plate obtained by rolling and cooling,
The other surface opposite to the one surface which contact | connected the outer peripheral surface of the said 2nd cooling roll is curved, The center of curvature is located in the said other surface side,
The curved direction coincides with at least one of the extrusion direction and the direction orthogonal to the extrusion direction,
The curvature radius of a thermoplastic resin extruded plate is 10-200 m, and the said thermoplastic resin extruded plate is for liquid crystal display protection plates, The thermoplastic resin extruded plate. The method according to claim 1 or 2,
The thermoplastic resin extruded board whose said thermoplastic resin is at least 1 sort (s) chosen from the group which consists of methyl methacrylate type resin, aromatic polycarbonate resin, styrene resin, and resin containing an alicyclic structure containing ethylenically unsaturated monomeric unit. The method according to claim 1 or 2,
The thermoplastic resin is made by laminating at least two kinds of thermoplastic resins,
The thermoplastic resin extruded plate which is at least 1 sort (s) chosen from the group which each laminated thermoplastic resin consists of methyl methacrylate type resin, aromatic polycarbonate resin, styrene resin, and resin containing an alicyclic structure containing ethylenically unsaturated monomeric unit. The method according to claim 1 or 2,
The thermoplastic resin extruded plate whose thickness of a thermoplastic resin extruded plate is 0.3-5 mm. delete delete

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