JP2015191163A - Front protective panel for image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a front protective panel for an image display device which is excellent in moist heat resistance and contributes to thinning, lightening and elaborate designing.SOLUTION: A front protective panel for an image display device comprises a resin composition containing a polycarbonate resin which has a structural unit (a) derived from a dihydroxy compound having a structure represented by the general formula (1) in the figure and a structural unit (b) derived from another dihydroxy compound. The structural unit (a) accounts for 40 mol% or more of all structural units of the dihydroxy compound included in the polycarbonate resin.

Description

  The present invention relates to a sheet made of a polycarbonate resin composition, and more particularly to a front protective panel for an image display device using the sheet.

Conventionally, a glass plate has been provided as a protective panel on the front side of an image display device such as a liquid crystal television so that the image display panel is not damaged by an external impact or the like.
Although the front protective panel is exposed to display light for a long time or receives heat transfer from the image display panel that generates heat, a glass plate having little deterioration with time under these circumstances has been used as a suitable material.

However, recent image display devices are increasingly required to be thinner and lighter, and to have a high design such as partially including a curved surface shape. In response to these new requirements, there is little deterioration in the usage environment. There is a need for transparent materials.
In response to such demands, transparent resin materials such as acrylic resins, cyclic olefin resins, and polycarbonate resins have been studied as glass substitute transparent materials.
However, acrylic resin and cyclic olefin resin are prone to brittleness when the sheet is thinned, and the loss of damage in the laminating and assembling process is likely to increase. Incorporation into a display device as a protective panel is not only difficult for mass production in a stable and high yield, but also the impact resistance of the incorporated product is often reduced compared to conventional materials. In addition, these resins can generally be made into sheets by melt film formation, but gelation reactions are likely to occur during thermoforming, and they are often visually recognized as foreign substances in the sheet, which makes it extremely difficult to manage defects. It is extremely difficult to use for such severe use.

An aromatic polycarbonate resin is excellent in flexibility and impact resistance, and a sheet obtained by a melt film-forming method is also preferable with less damage in the process.
However, since the aromatic compound is contained in the monomer structural unit, light absorption occurs, and the total light transmittance is remarkably lowered as compared with glass and the transparent resin. Therefore, it is not suitable as a front protective panel for an image display device. In addition, since the intrinsic birefringence of the material is large, even in an ordinary extruded sheet, the refractive index anisotropy tends to increase due to optical distortion due to residual stress. For example, when an image of an image display device on which this is mounted is viewed through polarized sunglasses, an iris pattern may appear on the entire surface and image recognition may be extremely difficult. For this reason, a special process for removing the optical distortion of the molded sheet may be required, and even if such a process is added, the required level of low optical distortion cannot be reduced in many cases.

  On the other hand, polycarbonate resins obtained from isosorbide (hereinafter sometimes abbreviated as ISB) are described as being excellent in transparency, hue, heat resistance, moldability, and mechanical strength. In addition, lens applications such as camera lenses, viewfinder lenses, CCD and CMOS lenses, retardation films used in liquid crystal and plasma displays, diffusion sheets, polarizing films, and other films, sheets, optical disks, optical materials, optical Use in a wide range of fields such as parts is also under consideration.

More specifically, Patent Document 1 describes that the optical properties are improved by devising a method for producing a polycarbonate resin obtained from ISB, and is suitable for application to the above-described field. Patent Document 2 discloses that the polycarbonate resin obtained from ISB contains a phosphorus compound, a hindered phenol compound, and an acidic compound, while maintaining high heat resistance and transparency, while maintaining a high refractive index. It is described that a polycarbonate resin obtained from a small highly transparent ISB can be obtained, and it is described that it is suitable for application in the above-mentioned field.

WO 2011/065505 pamphlet JP 2009-144020 A

However, as a front protective panel for an image display device, no resin has yet been found that satisfies all the characteristics of sheet formability, in-plane retardation, impact resistance, light transmittance, pencil hardness, and heat and humidity resistance. Further, if the shape of the front protective panel for an image display device changes in the surrounding environment such as humidity and temperature, the display performance of the image display device is affected.
Therefore, the object of the present invention is to eliminate the above-mentioned conventional problems, and is excellent in sheet formability, in-plane retardation, impact resistance, light transmittance, pencil hardness, moisture and heat resistance, thinning, weight reduction, high design An object of the present invention is to provide a front protective panel for an image display device that contributes to demands for the use of a display device.

As a result of intensive studies to solve the above problems, the present inventor has found that the present invention disclosed below can solve the above problems, and has completed the present invention.
That is, this invention is comprised by the following invention.
[1] having a structural unit (a) derived from a dihydroxy compound having a structure represented by the following general formula (1), and a structural unit (b) derived from another dihydroxy compound,
A front protective panel for an image display device comprising a resin composition containing a polycarbonate resin in which the proportion of the structural unit (a) in the total structural units of the dihydroxy compound constituting the polycarbonate resin is 40 mol% or more.

[2] The structural unit (b) in the polycarbonate resin is any structural unit selected from the group consisting of structural units derived from dihydroxy compounds represented by the following formulas (2) to (5). The front protective panel for an image display device according to [1], which is characterized in that
HO—R ¹ —OH (2)
(In formula (2), R ¹ represents a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms.)
HO—CH ₂ —R ² —CH ₂ —OH (3)
(In formula (3), R ² represents a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms.)
H- (O-R < ³ >) _p- OH (4)
(In Formula (4), R ³ represents a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, and p is an integer of 2 to 100.)
^HO-R 4 -OH (5)
(In formula (5), R ⁴ represents a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms, or a group having a substituted or unsubstituted acetal ring.) [3] Dihydroxy compound constituting the polycarbonate resin The resin composition according to [1] or [2], wherein the proportion of the structural unit (a) in all the structural units is 90 mol% or less.
[4] The resin composition according to any one of [1] to [3], wherein the reduced viscosity of the polycarbonate resin is 0.45 dl / g or more.
[5] The front protection for an image display device according to any one of [1] to [4], obtained by extrusion molding the resin composition to a thickness of 50 μm to 300 μm by a melt film forming method. panel.

  According to the present invention, it is excellent in heat and moisture resistance, and does not stand out even when it is thinned, making it possible to achieve significant weight reduction as a member compared to a glass plate, and imparting design properties such as a partially curved shape It is possible to provide a front protective panel for an image display device that can cope with the above.

Embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments, and can be implemented in various forms within the scope of the gist thereof.
The present invention has a structural unit (a) derived from a dihydroxy compound having a structure represented by the following general formula (1), and a structural unit (b) derived from another dihydroxy compound,
A front protective panel for an image display device comprising a resin composition containing a polycarbonate resin in which the proportion of the structural unit (a) in the total structural units of the dihydroxy compound constituting the polycarbonate resin is 40 mol% or more.

About.
(1) Polycarbonate resin and resin composition based thereon Polycarbonate resin constituting the present invention and resin composition based thereon are described in detail.

[Polycarbonate resin]
The polycarbonate resin of the present invention includes a structural unit (a) derived from a dihydroxy compound having a structure represented by the following general formula (1) (hereinafter sometimes referred to as “dihydroxy compound (1)”), and others. And a polycarbonate resin having a structural unit (b) derived from the dihydroxy compound (hereinafter sometimes referred to as “polycarbonate resin (A)” or “polycarbonate resin (A)”). And

<Dihydroxy compound (1)>
In the polycarbonate resin (A) of the present invention, the structural unit (a) derived from the dihydroxy compound having the structure represented by the general formula (1) (hereinafter may be referred to as “structural unit (1)”). Is included.
The ratio of the structural unit (1) (that is, the structural unit (a)) in the total structural units derived from the dihydroxy compound contained in the polycarbonate resin (A) of the present invention is not particularly limited, but the lower limit is usually It is 40 mol% or more, preferably 45 mol% or more, more preferably 50 mol% or more, and particularly preferably 55 mol% or more. The upper limit is usually 90 mol% or less, preferably 85 mol% or less, more preferably 80 mol% or less, and particularly preferably 75 mol% or less. When the ratio is greater than this ratio, the brittleness of the resin is particularly noticeable, and in-process breakage frequently occurs in the sheet formation by the melt film forming method and the assembly process using the sheet.

The polycarbonate resin (A) of the present invention containing the structural unit (1) derived from the dihydroxy compound (1) is, for example, 1 of the dihydroxy compound (1) according to the method for producing the polycarbonate resin (A) of the present invention described later. Manufactured using seeds or two or more.
Examples of the dihydroxy compound (1) include isosorbide, isomannide, and isoide which have a stereoisomeric relationship.

Among the above-mentioned dihydroxy compounds (1), they are abundant as resources and can be easily obtained, and isosorbide obtained by dehydrating condensation of sorbitol produced from various starches is easy to obtain and produce, Most preferable in terms of optical properties and moldability.
The dihydroxy compound (1) having a cyclic ether structure such as isosorbide is easily oxidized gradually by oxygen. For this reason, when storing or handling during manufacturing, it is important to prevent moisture from entering in order to prevent decomposition by oxygen, and to use an oxygen scavenger or handle under a nitrogen atmosphere. . When isosorbide is oxidized, decomposition products such as formic acid are generated. For example, when the polycarbonate resin (A) of the present invention is produced using isosorbide containing these decomposition products, the resulting polycarbonate resin (A) is colored. May occur, or the physical properties may be significantly deteriorated. Moreover, it may affect the polymerization reaction, and a high molecular weight polymer may not be obtained.

  Therefore, it is preferable to use a stabilizer for the dihydroxy compound (1). As the stabilizer, it is preferable to use stabilizers such as a reducing agent, an antacid, an antioxidant, an oxygen scavenger, a light stabilizer, a pH stabilizer, a heat stabilizer, and the like, and particularly under acidic conditions, the dihydroxy compound (1) It is preferable that a basic stabilizer is contained because of being easily altered. Among these, examples of the reducing agent include sodium borohydride and lithium borohydride, and examples of the antacid include alkalis such as sodium hydroxide. However, the addition of such an alkali metal salt is not preferable because the added alkali metal may serve as a polymerization catalyst during the production of the polycarbonate resin (A).

Basic stabilizers include hydroxides, carbonates, phosphates, phosphites, hypophosphorous acids of Group 1 or Group 2 metals in the Long Periodic Periodic Table (Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005). Salts, borates, fatty acid salts, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide, Triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium hydroxide, tributylbenzylammonium hydroxide, tributylphenylammonium Basic ammonium compounds such as ammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium hydroxide, butyltriphenylammonium hydroxide, 4-aminopyridine, 2-aminopyridine, N, N -Dimethyl-4-aminopyridine, 4-diethylaminopyridine, 2-hydroxypyridine, 2-methoxypyridine, 4-methoxypyridine, 2-dimethylaminoimidazole, 2-methoxyimidazole, imidazole, 2-mercaptoimidazole, 2-methylimidazole And amine compounds such as aminoquinoline. Of these, sodium or potassium phosphates and phosphites are preferable, and disodium hydrogen phosphate and disodium hydrogen phosphite are particularly preferable because of their effects and ease of distillation removal described later.

  Although there is no restriction | limiting in particular in content in the dihydroxy compound (1) of these basic stabilizers, if too little, there exists a possibility that the effect which prevents the modification of dihydroxy compound (1) may not be acquired, and if too much, a dihydroxy compound Since the modification of (1) may be caused, it is usually 0.0001% by weight to 1% by weight, preferably 0.001% by weight to 0.1% by weight, based on the dihydroxy compound (1).

  When the dihydroxy compound (1) to which these stabilizers are added is used as a raw material for the polycarbonate resin (A), depending on the type of the stabilizer, the resulting polycarbonate resin (A) may be colored or the physical properties may be significantly deteriorated. There is a case. For example, when the dihydroxy compound (1) containing the above basic stabilizer is used as a raw material for producing the polycarbonate resin (A), the basic stabilizer itself becomes a polymerization catalyst, and it becomes difficult to control the polymerization rate and quality. In addition, the initial hue is deteriorated, and the resultant molded article of the polycarbonate resin (A) is deteriorated in light resistance.

For this reason, before using dihydroxy compound (1) as a manufacturing raw material of polycarbonate resin (A), it is preferable to remove stabilizers, such as a basic stabilizer, by ion exchange resin or distillation.
Moreover, as mentioned above, when the dihydroxy compound (1) containing the oxidative decomposition product of the dihydroxy compound (1) is used as a raw material for producing the polycarbonate resin (A), the resulting polycarbonate resin (A) may be colored. In addition, there is a possibility that not only the physical properties may be remarkably deteriorated, but also the polymerization reaction is affected and a high molecular weight polymer may not be obtained.

  For this reason, in order to obtain the dihydroxy compound (1) which does not contain an oxidative decomposition product, and in order to remove the above-mentioned basic stabilizer, it is preferable to perform distillation purification of the dihydroxy compound (1). The distillation in this case may be simple distillation or continuous distillation, and is not particularly limited. As distillation conditions, it is preferable to carry out distillation under reduced pressure in an inert gas atmosphere such as argon or nitrogen. In order to suppress thermal denaturation, it is 250 ° C. or lower, preferably 200 ° C. or lower, particularly 180 °. It is preferable to carry out under the conditions of ℃ or less.

By such distillation purification, the oxidative decomposition product in the dihydroxy compound (1), for example, formic acid content is 20 ppm by weight or less, preferably 10 ppm by weight or less, particularly preferably 5 ppm by weight or less. The polycarbonate resin (A) excellent in hue and thermal stability can be produced without impairing the polymerization reactivity during the production of the resin (A).
The formic acid content of the dihydroxy compound (1) is measured using ion chromatography according to the following procedure. In the following procedure, isosorbide is taken as an example as a representative dihydroxy compound (1).

About 0.5 g of isosorbide is precisely weighed and collected in a 50 ml volumetric flask and made up to volume with pure water. A sodium formate aqueous solution is used as a standard sample, and the peak having the same retention time as that of the standard sample is defined as formic acid, and quantified by an absolute calibration curve method from the peak area.
The ion chromatograph uses DX-500 type manufactured by Dionex, and an electric conductivity detector is used as a detector. As a measurement column, AG-15 is used for a guard column manufactured by Dionex, and AS-15 is used for a separation column. A measurement sample is injected into a 100 μl sample loop, and 10 mM NaOH is used as an eluent, and the measurement is performed at a flow rate of 1.2 ml / min and a thermostat temperature of 35 ° C. A membrane suppressor is used as the suppressor, and a 12.5 mM-H ₂ SO ₄ aqueous solution is used as the regenerating solution.

<Dihydroxy compounds other than dihydroxy compound (1)>
In addition to the structural unit (1), the polycarbonate resin (A) of the present invention contains a structural unit (b) derived from a dihydroxy compound other than the dihydroxy compound (1).
The polycarbonate resin (A) of the present invention containing the structural unit (b) derived from a dihydroxy compound other than the dihydroxy compound (1) can be produced, for example, according to the production method of the polycarbonate resin (A) of the present invention described later. It is produced using one or more dihydroxy compounds other than 1).

The structural unit (b) contained in the polycarbonate resin (A) of the present invention is any structural unit selected from the group consisting of structural units derived from dihydroxy compounds represented by the following formulas (2) to (5). Preferably there is.
In the following, the dihydroxy compounds represented by the formulas (2), (3), (4) and (5) are respectively represented by “dihydroxy compound (2)”, “dihydroxy compound (3)” and “dihydroxy compound (4)”. ”And“ dihydroxy compound (5) ”, the structural units derived from the dihydroxy compounds (2), (3), (4), and (5) are referred to as“ structural unit (2) ”and“ structural unit (3) ”, respectively. ”,“ Structural unit (4) ”, and“ structural unit (5) ”.

HO—R ¹ —OH (2)
(In formula (2), R ¹ represents a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms.)
HO—CH ₂ —R ² —CH ₂ —OH (3)
(In formula (3), R ² represents a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms.)
H- (O-R < ³ >) _p- OH (4)
(In Formula (4), R ³ represents a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, and p is an integer of 2 to 100.)
^HO-R 4 -OH (5)
(In formula (5), R ⁴ represents a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms, or a group having a substituted or unsubstituted acetal ring.)
Among the dihydroxy compounds (2) to (5), the polycarbonate resin (A) of the present invention preferably contains a structural unit derived from an aliphatic dihydroxy compound, and in particular, derived from an alicyclic dihydroxy compound. It is preferable that the structural unit to be included is included. In this case, flexibility can be imparted to the obtained polycarbonate resin (A).

(Aliphatic dihydroxy compound)
Examples of the aliphatic dihydroxy compound include aliphatic dihydroxy compounds in which R ⁴ is a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms among the dihydroxy compounds represented by the formula (5). Examples of the aliphatic dihydroxy compound include 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, and 2-ethyl. -1,6-hexanediol, 2,2,4-trimethyl-1,6-hexanediol, 1,10-decanediol, hydrogenated dilinoleyl glycol, hydrogenated dioleyl glycol and the like.
In addition, the said exemplary compound is an example of the aliphatic dihydroxy compound which can be used for this invention, Comprising: It is not limited to these at all. These aliphatic dihydroxy compounds may be used individually by 1 type, and 2 or more types may be mixed and used for them.

(Alicyclic dihydroxy compound)
Although it does not specifically limit as an alicyclic dihydroxy compound, Usually, the compound containing a 5-membered ring structure or a 6-membered ring structure is mentioned. When the alicyclic dihydroxy compound has a 5-membered ring structure or a 6-membered ring structure, the heat resistance of the obtained polycarbonate resin (A) may be increased. The six-membered ring structure may be fixed in a chair shape or a boat shape by a covalent bond. Carbon number contained in an alicyclic dihydroxy compound is 70 or less normally, Preferably it is 50 or less, More preferably, it is 30 or less. When the number of carbon atoms is excessively large, the heat resistance becomes high, but synthesis tends to be difficult, purification becomes difficult, and cost tends to be high. The smaller the carbon number, the easier it is to purify and the easier it is to obtain.

Specific examples of the alicyclic dihydroxy compound containing a 5-membered ring structure or a 6-membered ring structure include the dihydroxy compounds (2) and (3).
As cyclohexanedimethanol which is an alicyclic dihydroxy compound represented by the above formula (3), in the above formula (3), R ² is the following formula (3a) (wherein R ⁵ is a hydrogen atom or substituted Or an unsubstituted alkyl group having 1 to 12 carbon atoms.). Specific examples thereof include 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, and the like.

As tricyclodecane dimethal and pentacyclopentadecane dimethanol, which are alicyclic dihydroxy compounds represented by the formula (3), in the formula (3), R ² is represented by the following formula (3b) (wherein n Represents 0 or 1).

As decalin dimethanol or tricyclotetradecane dimethanol which is an alicyclic dihydroxy compound represented by the formula (3), in the formula (3), R ² is represented by the following formula (3c) (where m is It represents 0 or 1). Specific examples thereof include 2,6-decalin dimethanol, 1,5-decalin dimethanol, 2,3-decalin dimethanol, and the like.

Moreover, as norbornanedimethanol which is an alicyclic dihydroxy compound represented by the formula (3), in the formula (3), R ² includes various isomers represented by the following formula (3d). . Specific examples thereof include 2,3-norbornane dimethanol, 2,5-norbornane dimethanol and the like.

The adamantane dimethanol, which is an alicyclic dihydroxy compound represented by the formula (3), includes various isomers in which R ² is represented by the following general formula (3e) in the formula (3). Specific examples of such a material include 1,3-adamantane dimethanol.

In addition, cyclohexanediol, which is an alicyclic dihydroxy compound represented by the formula (2), in the formula (2), R ¹ is represented by the following formula (2a) (wherein R ⁵ is a hydrogen atom, substituted or non-substituted). A substituted alkyl group having 1 to 12 carbon atoms). Specific examples thereof include 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 2-methyl-1,4-cyclohexanediol, and the like.

As tricyclodecanediol and pentacyclopentadecanediol, which are alicyclic dihydroxy compounds represented by the formula (2), in the formula (2), R ¹ is represented by the following general formula (2b) (where n is It represents 0 or 1).

As decalin diol or tricyclotetradecane diol which is an alicyclic dihydroxy compound represented by the formula (2), in the formula (2), R ¹ is represented by the following general formula (2c).
) (Wherein m represents 0 or 1). Specifically, 2,6-decalindiol, 1,5-decalindiol, 2,3-decalindiol and the like are used as such.

The norbornanediol which is an alicyclic dihydroxy compound represented by the formula (2) includes various isomers in which R ¹ is represented by the following general formula (2d) in the formula (2). Specifically, 2,3-norbornanediol, 2,5-norbornanediol, and the like are used as such.

The adamantanediol which is an alicyclic dihydroxy compound represented by the above formula (2) includes various isomers in which R ¹ is represented by the following formula (2e) in the above formula (2). Specifically, 1,3-adamantanediol etc. are used as such.

Among the specific examples of the alicyclic dihydroxy compounds described above, cyclohexane dimethanols, tricyclodecane dimethanols, adamantane diols, and pentacyclopentadecane dimethanols are preferable, and are easily available and easy to handle. From the viewpoint, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, and tricyclodecane dimethanol are particularly preferable.
In addition, the said exemplary compound is an example of the alicyclic dihydroxy compound which can be used for this invention, Comprising: It is not limited to these at all. These alicyclic dihydroxy compounds may be used individually by 1 type, and 2 or more types may be mixed and used for them.

(Polyoxyalkylene dihydroxy compound)
The polyoxyalkylene dihydroxy compound which is a dihydroxy compound represented by the formula (4) is preferable from the viewpoint of flexibility, flexibility, polymerization reactivity, and hue of the obtained polycarbonate resin. The polyoxyalkylene dihydroxy compound, which is a dihydroxy compound represented by the formula (4), is a compound having a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, preferably 2 to 5 carbon atoms, in R ^3. is there. p is an integer of 2 to 100, preferably 2 to 50, more preferably 6 to 30, and still more preferably 12 to 15.

  Specific examples of the polyoxyalkylene dihydroxy compound that is the dihydroxy compound represented by the formula (4) include diethylene glycol, triethylene glycol, polyethylene glycol (molecular weight 150 to 4000), and the like. It is not limited to. The dihydroxy compound represented by the formula (4) is preferably polyethylene glycol having a molecular weight of 300 to 2000, and more preferably polyethylene glycol having a molecular weight of 600 to 1500.

These may be used alone or in combination of two or more depending on the required performance of the polycarbonate resin (A) to be obtained.
In addition, the said exemplary compound is an example of the polyoxyalkylene dihydroxy compound which can be used for this invention, Comprising: It is not limited to these at all. These polyoxyalkylene dihydroxy compounds may be used individually by 1 type, and 2 or more types may be mixed and used for them.

(Dihydroxy compound having an alkylene group or a group having an acetal ring)
The dihydroxy compound represented by the formula (5) is a group having a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms, or a substituted or unsubstituted acetal ring in R ^4. It has a dihydroxy compound. When the alkylene group of R ⁴ has a substituent, examples of the substituent include an alkyl group having 1 to 5 carbon atoms. In addition, when the group having an acetal ring of R ⁴ has a substituent, examples of the substituent include an alkyl group having 1 to 3 carbon atoms.

Among the dihydroxy compounds (5), examples of the dihydroxy compound in which R ⁴ is a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms include propanediols such as 1,3-propanediol and 1,2-propanediol. , Butanediols such as 1,4-butanediol and 1,3-butanediol, heptanediols such as 1,5-heptanediol, hexanediols such as 1,6-hexanediol, etc. It is not limited to these. Of these, hexanediols are preferred.

On the other hand, the dihydroxy compound in which R ⁴ is a group having a substituted or unsubstituted acetal ring is not particularly limited, and among these, spiro as represented by the following formulas (8) and (9): A dihydroxy compound having a structure is preferable, and a dihydroxy compound having a plurality of ring structures as represented by the following formula (8) is particularly preferable.

Among these dihydroxy compounds, from the viewpoint of easy availability, ease of handling, high reactivity during polymerization, and the hue of the polycarbonate resin to be obtained, the dihydroxy compound (5) is 1, 3 -Propanediol and 1,6-hexanediol are preferred. Further, from the viewpoint of heat resistance, dihydroxy compounds having a group having an acetal ring are preferable, and those having a plurality of ring structures represented by the above formula (8) are particularly preferable.

These may be used alone or in combination of two or more depending on the required performance of the polycarbonate resin (A) to be obtained.
When the polycarbonate resin (A) of the present invention has a structural unit derived from an alicyclic dihydroxy compound, the structural unit (1) in the polycarbonate resin (A) of the present invention and the aforementioned dihydroxy which is the structural unit (b). Although the molar ratio with the structural unit derived from the compounds (2) to (5) can be selected at an arbitrary ratio, impact strength (for example, notched Charpy impact strength) is improved by adjusting the molar ratio. In addition, it is possible to obtain a desired glass transition temperature in the polycarbonate resin (A).

(Other dihydroxy compounds)
In addition to the structural unit (1) and the structural units (2) to (5), the polycarbonate resin (A) of the present invention may further include structural units derived from other dihydroxy compounds. Other dihydroxy compounds include aromatic dihydroxy compounds.

Examples of the aromatic dihydroxy compound include a substituted or unsubstituted bisphenol compound. Specifically, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 1,1- Bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) butane, 1, 1-bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) pentane, 3,3-bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) -3 -Methylbutane, 1,1-bis (4-hydroxyphenyl) hexane, 2,2-bis (4-hydroxyphenyl) hexa 3,3-bis (4-hydroxyphenyl) hexane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis Bisphenol compounds having no substituent on the aromatic ring such as (4-hydroxyphenyl) cyclohexane; bis (3-phenyl-4-hydroxyphenyl) methane, 1,1-bis (3-phenyl-4-hydroxyphenyl) Bisphenol having an aryl group as a substituent on an aromatic ring such as ethane, 1,1-bis (3-phenyl-4-hydroxyphenyl) propane, 2,2-bis (3-phenyl-4-hydroxyphenyl) propane Compound: bis (4-hydroxy-3-methylphenyl) methane, 1,1-bis (4-hydroxy-3-methylphenyl) Nyl) ethane, 1,1-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3-) Methylphenyl) cyclohexane, bis (4-hydroxy-3-ethylphenyl) methane, 1,1-bis (4-hydroxy-3-ethylphenyl) ethane, 1,1-bis (4-hydroxy-3-ethylphenyl) Propane, 2,2-bis (4-hydroxy-3-ethylphenyl) propane, 1,1-bis (4-hydroxy-3-ethylphenyl) cyclohexane, 2,2-bis (4-hydroxy-3-isopropylphenyl) ) Propane, 2,2-bis (4-hydroxy-3- (sec-butyl) phenyl) propane, bis (4-hydroxy-3,5-dimethyl) Tilphenyl) methane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) ethane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 1,1-bis (4- Hydroxy-3,5-dimethylphenyl) cyclohexane, bis (4-hydroxy-3,6-dimethylphenyl) methane, 1,1-bis (4-hydroxy-3,6-dimethylphenyl) ethane, 2,2-bis (4-hydroxy-3,6-dimethylphenyl) propane, bis (4-hydroxy-2,3,5-trimethylphenyl) methane, 1,1-bis (4-hydroxy-2,3,5-trimethylphenyl) Ethane, 2,2-bis (4
-Hydroxy-2,3,5-trimethylphenyl) propane, bis (4-hydroxy-2,3,5-trimethylphenyl) phenylmethane, 1,1-bis (4-hydroxy-2,3,5-trimethylphenyl) ) Bisphenol compounds having an alkyl group as a substituent on an aromatic ring such as phenylethane and 1,1-bis (4-hydroxy-2,3,5-trimethylphenyl) cyclohexane; bis (4-hydroxyphenyl) phenylmethane 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,1-bis (4-hydroxyphenyl) -1-phenylpropane, bis (4-hydroxyphenyl) diphenylmethane, bis (4-hydroxyphenyl) ) A divalent group connecting an aromatic ring such as dibenzylmethane has an aryl group as a substituent. Bisphenol compounds; 4,4′-dihydroxydiphenyl ether, bisphenol compounds in which aromatic rings such as 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxydiphenyl ether are linked by an ether bond; A bisphenol compound in which aromatic rings such as dihydroxydiphenylsulfone and 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxydiphenylsulfone are linked by a sulfone bond; 4,4′-dihydroxydiphenylsulfide, 3 , 3 ′, 5,5′-tetramethyl-4,4′-dihydroxydiphenyl sulfide, and the like include bisphenol compounds in which aromatic rings are connected by a sulfide bond, preferably 2,2-bis (4-hydroxy Phenyl) propane (hereinafter sometimes abbreviated as “bisphenol A”). It is.

In the polycarbonate resin (A) of the present invention, the content of the structural unit derived from the aromatic dihydroxy compound is 0 with respect to the structural unit derived from all the dihydroxy compounds contained in the polycarbonate resin (A) of the present invention. It is preferably at least mol% and less than 1 mol%, more preferably at least 0 mol% and less than 0.8 mol%, and even more preferably at least 0 mol% and less than 0.5 mol%. By including the structural unit derived from the aromatic dihydroxy compound in the polycarbonate resin (A), improvement in heat resistance, surface impact resistance, molding processability, etc. can be expected, but the inclusion of the structural unit derived from the aromatic dihydroxy compound When there is too much quantity, there exists a possibility that coloring may become remarkable.
The above-mentioned other hydroxy compounds may be used alone or in combination of two or more.

<Carbonated diester>
The polycarbonate resin (A) of the present invention can be produced by a generally used polymerization method, and the polymerization method can be any of an interfacial polymerization method using phosgene and a melt polymerization method in which a transesterification reaction with a carbonic acid diester is performed. However, a melt polymerization method in which a dihydroxy compound is reacted with a carbon dioxide diester having lower environmental toxicity in the presence of a polymerization catalyst is preferable.

In this case, the polycarbonate resin (A) of the present invention can be obtained by a melt polymerization method in which a dihydroxy compound containing the above-described dihydroxy compound (1) and a carbonic acid diester are transesterified.
As a carbonic acid diester used, what is normally represented by following formula (6) is mentioned. These carbonic acid diesters may be used alone or in combination of two or more.

In the above formula (6), A ¹ and A ² are each independently a substituted or unsubstituted aliphatic group having 1 to 18 carbon atoms, or a substituted or unsubstituted aromatic group.
Examples of the carbonic acid diester represented by the above formula (6) include substituted diphenyl carbonates such as diphenyl carbonate and ditolyl carbonate, dimethyl carbonate, diethyl carbonate, and di-t-butyl carbonate, preferably diphenyl carbonate. Carbonates and substituted diphenyl carbonates, particularly preferably diphenyl carbonate. The carbonic acid diester may contain impurities such as chloride ions, and these impurities may hinder the polymerization reaction or may deteriorate the hue of the resulting polycarbonate resin (A). Accordingly, it is preferable to use a product purified by distillation or the like.

The carbonic acid diester is preferably used in a molar ratio of 0.90 to 1.20, more preferably in a molar ratio of 0.95 to 1.10, based on all dihydroxy compounds used in the melt polymerization. It is even more preferable to use at a molar ratio of .96 to 1.10, and particularly preferable to use at a molar ratio of 0.98 to 1.04.
When this molar ratio is less than 0.90, the terminal hydroxyl group of the produced polycarbonate resin (A) is increased, the thermal stability of the polymer is deteriorated, and coloring occurs when the resin composition of the present invention is molded. Or the rate of transesterification may be reduced, or the desired high molecular weight product may not be obtained.

  If this molar ratio is greater than 1.20, the rate of the transesterification reaction decreases under the same conditions, making it difficult to produce a polycarbonate resin (A) having a desired molecular weight. The amount of residual carbonic acid diester in (A) increases, and this residual carbonic acid diester may be unfavorable at the time of molding or the odor of the molded product, increasing the heat history during the polymerization reaction, resulting in The hue and weather resistance of the obtained polycarbonate resin (A) may be deteriorated.

  Furthermore, when the molar ratio of the carbonic acid diester to the total dihydroxy compound increases, the amount of residual carbonic acid diester in the resulting polycarbonate resin (A) increases, and these absorb the ultraviolet rays to increase the light resistance of the polycarbonate resin (A). It may worsen and is not preferable. The concentration of the carbonic acid diester remaining in the polycarbonate resin (A) of the present invention is preferably 200 ppm by weight or less, more preferably 100 ppm by weight or less, particularly preferably 60 ppm by weight or less, and particularly preferably 30 ppm by weight or less. However, actually, the polycarbonate resin (A) may contain an unreacted carbonic acid diester, and the lower limit value of the unreacted carbonic acid diester concentration in the polycarbonate resin (A) is usually 1 ppm by weight.

<Transesterification reaction catalyst>
The polycarbonate resin (A) of the present invention can be produced by transesterifying the dihydroxy compound containing the dihydroxy compound (1) and the carbonic acid diester represented by the formula (6) as described above. More specifically, it can be obtained by transesterification to remove by-product monohydroxy compounds and the like out of the system. In this case, melt polymerization is usually carried out by transesterification in the presence of a transesterification catalyst.

  Examples of the transesterification catalyst (hereinafter sometimes referred to as “catalyst”) that can be used in the production of the polycarbonate resin (A) of the present invention include 1 in the long-period periodic table (Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005). A basic compound such as a metal compound, a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound of a group or group 2 (hereinafter simply referred to as “group 1” or “group 2”) Can be mentioned. Among these, Preferably a group 1 metal compound and / or a group 2 metal compound are used.

It is possible to use a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, and an amine compound in combination with the Group 1 metal compound and / or the Group 2 metal compound. It is particularly preferred to use only Group 1 metal compounds and / or Group 2 metal compounds.
In addition, the group 1 metal compound and / or the group 2 metal compound are usually used in the form of a hydroxide or a salt such as a carbonate, a carboxylate, or a phenol salt. From the viewpoint of easiness, a hydroxide, carbonate, and acetate are preferable, and acetate is preferable from the viewpoint of hue and polymerization activity.

  Examples of the Group 1 metal compound include sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, sodium hydrogen carbonate, potassium hydrogen carbonate, lithium hydrogen carbonate, cesium hydrogen carbonate, sodium carbonate, potassium carbonate, lithium carbonate, Cesium carbonate, sodium acetate, potassium acetate, lithium acetate, cesium acetate, sodium stearate, potassium stearate, lithium stearate, cesium stearate, sodium borohydride, potassium borohydride, lithium borohydride, cesium borohydride , Sodium borohydride, potassium borohydride, lithium phenide boron, cesium phenide boron, sodium benzoate, potassium benzoate, lithium benzoate, cesium benzoate, 2 sodium hydrogen phosphate 2 potassium potassium phosphate, 2 lithium hydrogen phosphate, 2 cesium hydrogen phosphate, 2 sodium phenyl phosphate, 2 potassium phenyl phosphate, 2 lithium phenyl phosphate, 2 cesium phenyl phosphate, sodium, potassium, lithium, Examples include cesium alcoholate, phenolate, disodium salt of bisphenol A, 2 potassium salt, 2 lithium salt, 2 cesium salt, etc. Among them, cesium compound and lithium compound are preferable.

  Examples of the Group 2 metal compound include calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, strontium hydrogen carbonate, calcium carbonate, barium carbonate, magnesium carbonate, Strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, strontium stearate and the like, among which magnesium compounds, calcium compounds and barium compounds are preferred, magnesium compounds and / or Or a calcium compound is still more preferable.

  Examples of the basic boron compound include tetramethyl boron, tetraethyl boron, tetrapropyl boron, tetrabutyl boron, trimethylethyl boron, trimethylbenzyl boron, trimethylphenyl boron, triethylmethyl boron, triethylbenzyl boron, triethylphenyl boron, tributylbenzyl. Examples include sodium, potassium, lithium, calcium, barium, magnesium, or strontium salts such as boron, tributylphenylboron, tetraphenylboron, benzyltriphenylboron, methyltriphenylboron, butyltriphenylboron, etc. It is done.

Examples of the basic phosphorus compound include triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tributylphosphine, and quaternary phosphonium salts.
Examples of the basic ammonium compound include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide, Triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium hydroxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium hydroxide Sid, butyl triphenyl ammonium hydroxide, and the like.

  Examples of the amine compound include 4-aminopyridine, 2-aminopyridine, N, N-dimethyl-4-aminopyridine, 4-diethylaminopyridine, 2-hydroxypyridine, 2-methoxypyridine, 4-methoxypyridine, 2 -Dimethylaminoimidazole, 2-methoxyimidazole, imidazole, 2-mercaptoimidazole, 2-methylimidazole, aminoquinoline and the like.

Among the above, at least one metal compound selected from the group consisting of a Group 2 metal compound and a lithium compound is used as a catalyst. Various properties such as transparency, hue, and light resistance of the resulting polycarbonate resin (A) are used. It is preferable in order to make the physical properties excellent.
In order to make the polycarbonate resin (A) particularly excellent in transparency, hue, and light resistance, the catalyst is at least one metal compound selected from the group consisting of magnesium compounds and calcium compounds. preferable.

In the case of a Group 1 metal compound and / or a Group 2 metal compound, the amount of the catalyst used is preferably 0.1 to 300 μmol, more preferably as a metal equivalent with respect to 1 mol of all dihydroxy compounds subjected to the reaction. It is in the range of 0.1 to 100 μmol, more preferably 0.5 to 50 μmol, and even more preferably 1 to 25 μmol.
Among the above, when using a compound containing at least one metal selected from the group consisting of lithium and a group 2 metal, particularly when using a magnesium compound and / or a calcium compound, the total amount subjected to the reaction as a metal equivalent amount is used. The amount is preferably 0.1 μmol or more, more preferably 0.5 μmol or more, and particularly preferably 0.7 μmol or more per mole of the dihydroxy compound. The upper limit is preferably 20 μmol, more preferably 10 μmol, particularly preferably 3 μmol, and most preferably 2.0 μmol.

  If the amount of the catalyst used is too small, the polymerization activity necessary for producing the polycarbonate resin (A) having a desired molecular weight cannot be obtained, and sufficient breaking energy may not be obtained. On the other hand, if the amount of the catalyst used is too large, not only will the hue of the resulting polycarbonate resin (A) be deteriorated, but also by-products may be generated, resulting in a decrease in fluidity and the generation of gel, resulting in brittle fracture. This may cause the production of polycarbonate resin (A) having a target quality.

<Production method of polycarbonate resin (A)>
The polycarbonate resin (A) of the present invention is obtained by melt polymerization of a dihydroxy compound containing the dihydroxy compound (1) and a carbonic acid diester by an ester exchange reaction. The raw material dihydroxy compound and the carbonic acid diester are transesterified. It is preferable to mix uniformly before.

  The mixing temperature is usually 80 ° C. or higher, preferably 90 ° C. or higher, and the upper limit is usually 250 ° C. or lower, preferably 200 ° C. or lower, more preferably 150 ° C. or lower. Among these, 100 ° C. or higher and 120 ° C. or lower is preferable. If the mixing temperature is too low, the dissolution rate may be slow or the solubility may be insufficient, often causing problems such as solidification, and if the mixing temperature is too high, the dihydroxy compound may be thermally deteriorated. There is a possibility that the hue of the polycarbonate resin (A) obtained will deteriorate and the light resistance will be adversely affected.

In addition, the operation of mixing the dihydroxy compound and the carbonic acid diester is performed using an oxygen concentration of 10% by volume.
Hereinafter, the polycarbonate resin (A) obtained by further performing in an atmosphere of 0.0001% by volume to 10% by volume, especially 0.0001% by volume to 5% by volume, particularly 0.0001% by volume to 1% by volume. ) From the viewpoint of preventing hue deterioration.
The polycarbonate resin (A) of the present invention is preferably produced by melt polymerization in multiple stages using a plurality of reactors using a catalyst. The reason for carrying out melt polymerization in multiple reactors is that at the beginning of the melt polymerization reaction, it is important to suppress the volatilization of the monomer while maintaining the required polymerization rate because there are many monomers contained in the reaction solution. In the latter stage of the melt polymerization reaction, it is important to sufficiently distill off the by-produced monohydroxy compound in order to shift the equilibrium to the polymerization side. Thus, in order to set different polymerization reaction conditions, it is preferable from the viewpoint of production efficiency to use a plurality of reactors arranged in series. As described above, the number of the reactors may be at least two, but from the viewpoint of production efficiency, the number of reactors is three or more, preferably 3 to 5, and particularly preferably four.

The type of reaction may be any of batch type, continuous type, or a combination of batch type and continuous type.
Furthermore, it is effective to use a reflux condenser for the polymerization reactor in order to suppress the amount of the monomer to be distilled off, and the effect is particularly great in a reactor at the initial stage of polymerization where there are many unreacted monomer components. The temperature of the refrigerant introduced into the reflux condenser can be appropriately selected according to the monomer used, but the temperature of the refrigerant introduced into the reflux condenser is usually 45 to 180 ° C. at the inlet of the reflux condenser. Yes, preferably 80 to 150 ° C, particularly preferably 100 to 130 ° C. If the temperature of the refrigerant introduced into the reflux condenser is too high, the reflux amount is reduced and the effect is reduced. If it is too low, the distillation efficiency of the monohydroxy compound to be originally distilled tends to be reduced. As the refrigerant, hot water, steam, heat medium oil or the like is used, and steam or heat medium oil is preferable.

In order to maintain the polymerization rate appropriately and suppress the distillation of the monomer, while maintaining the hue, thermal stability, light resistance, etc. of the finally obtained polycarbonate resin (A), the above-mentioned catalyst is used. It is important to select the type and amount.
In the production of the polycarbonate resin (A) of the present invention, if there are two or more reactors, the reactor is further provided with a plurality of reaction stages having different conditions, and the temperature and pressure are continuously changed. You may go.

In the production of the polycarbonate resin (A) of the present invention, the catalyst can be added to the raw material preparation tank, the raw material storage tank, or can be directly added to the reactor. The catalyst supply line is installed in the middle of the raw material line before being supplied to the reactor, and preferably supplied as an aqueous solution.
As the polymerization conditions, it is preferable to obtain a prepolymer at a relatively low temperature and low vacuum in the initial stage of polymerization and to increase the molecular weight to a predetermined value at a relatively high temperature and high vacuum in the late stage of polymerization. Appropriate selection of the jacket temperature and internal temperature at the stage and the pressure in the reaction system is important from the viewpoint of the hue and light resistance of the resulting polycarbonate resin (A). For example, if either the temperature or the pressure is changed too quickly before the polymerization reaction reaches a predetermined value, the unreacted monomer will be distilled, causing the molar ratio of the dihydroxy compound and the carbonic acid diester to change, resulting in a decrease in the polymerization rate. Or a polymer having a predetermined molecular weight or terminal group may not be obtained, and as a result, the object of the present invention may not be achieved.

If the temperature of the transesterification reaction is too low, the productivity is lowered and the thermal history of the product is increased. If the temperature is too high, not only the evaporation of the monomer is caused, but also the decomposition and coloring of the polycarbonate resin (A) can be promoted. There is sex.
In the production of the polycarbonate resin (A) of the present invention, the method of transesterifying the dihydroxy compound containing the dihydroxy compound (1) and the carbonic acid diester in the presence of a catalyst is usually carried out in a multistage process of two or more stages. . Specifically, the first stage transesterification reaction temperature (hereinafter sometimes referred to as “internal temperature”) is preferably 140 ° C. or higher, more preferably 150 ° C. or higher, more preferably 180 ° C. or higher, and even more. Preferably it is 200 degreeC or more. Further, the transesterification temperature in the first stage is preferably 270 ° C. or lower, more preferably 240 ° C. or lower, further preferably 230 ° C. or lower, and even more preferably 220 ° C. or lower. The residence time in the first stage transesterification reaction is usually 0.1 to 10 hours, preferably 0.5 to 3 hours, and the first stage transesterification reaction involves removing the generated monohydroxy compound from the reaction system. It is carried out while distilling off. In the second and subsequent stages, the transesterification reaction temperature is increased, and the transesterification reaction is usually performed at a temperature of 210 to 270 ° C., preferably 220 to 250 ° C., while simultaneously removing the monohydroxy compound generated outside the reaction system. The pressure of the reaction system is gradually lowered from the pressure in the first stage, so that the pressure of the reaction system finally becomes 200 Pa or less, usually 0.1 to 10 hours, preferably 0.5 to 6 hours, Particularly preferably, the polycondensation reaction is performed for 1 to 3 hours.

  When the transesterification reaction temperature is excessively high, the hue is deteriorated when formed into a molded product, which may easily cause brittle fracture. When the transesterification reaction temperature is too low, the target molecular weight does not increase, the molecular weight distribution becomes wide, and the impact strength may be inferior. Further, if the residence time of the transesterification reaction is excessively long, brittle fracture may easily occur. If the residence time is too short, the target molecular weight may not increase and the impact strength may be inferior.

The by-produced monohydroxy compound is preferably reused as a raw material for carbonic acid diesters and various bisphenol compounds after purification as necessary from the viewpoint of effective utilization of resources.
In particular, in order to obtain a good polycarbonate resin (A) having a high impact strength by suppressing the coloring, thermal deterioration or burn of the polycarbonate resin (A), the maximum temperature of the reactor in all reaction stages is less than 255 ° C. Preferably it is 250 degrees C or less, It is especially preferable that it is 225-245 degreeC. In addition, in order to suppress the lowering of the polymerization rate in the latter half of the polymerization reaction and to minimize the thermal deterioration of the polycarbonate resin (A) due to the thermal history, a horizontal reaction excellent in plug flow property and interface renewability at the final stage of the reaction. It is preferable to use a vessel.

  In addition, in order to obtain a polycarbonate resin (A) having a high impact strength and obtaining a polycarbonate resin (A) having a high molecular weight, the polymerization temperature may be increased as much as possible to increase the polymerization time. Foreign matter and burns in the resin (A) are generated and tend to be brittlely broken. Therefore, in order to satisfy both the high impact strength and the difficulty of brittle fracture, the polymerization temperature is kept low, the use of a highly active catalyst for shortening the polymerization time, and the appropriate reaction system pressure setting. Etc. are preferably adjusted. Furthermore, it is preferable to remove foreign matters or burns generated in the reaction system by a filter or the like in the middle of the reaction or at the final stage of the reaction in order to prevent brittle fracture.

In addition, when manufacturing polycarbonate resin (A) using substituted diphenyl carbonates, such as diphenyl carbonate and ditolyl carbonate, as carbonic acid diester represented by said Formula (6), phenol and substituted phenol are by-produced and polycarbonate. Residue in the resin (A) is unavoidable, but phenol and substituted phenol also have an aromatic ring, which absorbs ultraviolet rays and may cause deterioration of light resistance. It may be a cause. The polycarbonate resin (A) contains an aromatic monohydroxy compound having an aromatic ring such as by-product phenol of 1000 ppm by weight or more after a normal batch reaction, but from the viewpoint of light resistance and odor reduction. The content of the aromatic monohydroxy compound in the polycarbonate resin (A) is preferably 700 ppm by weight or less, more preferably 500 ppm by weight, using a horizontal reactor excellent in devolatilization performance or an extruder with a vacuum vent. In the following, it is particularly preferable that the content be 300 ppm by weight or less. However, it is difficult to remove the aromatic monohydroxy compound completely industrially, and the lower limit of the content of the aromatic monohydroxy compound in the polycarbonate resin (A) is usually 1 ppm by weight. In addition, these aromatic monohydroxy compounds may naturally have a substituent depending on the raw material used, and may have, for example, an alkyl group having 5 or less carbon atoms.

  In addition, Group 1 metals, especially lithium, sodium, potassium, cesium, especially sodium, potassium, cesium, may be mixed not only from the catalyst used but also from raw materials and reactors. Since it may adversely affect the hue if contained in a large amount in (A), the total content of these compounds in the polycarbonate resin (A) of the present invention is preferably as small as possible, and the polycarbonate resin (A) The amount of the metal is usually 1 ppm by weight or less, preferably 0.8 ppm by weight or less, more preferably 0.7 ppm by weight or less.

The amount of metal in the polycarbonate resin (A) can be measured by various conventionally known methods. After recovering the metal in the polycarbonate resin (A) by a method such as wet ashing, atomic emission, It can be measured by using a method such as absorption, Inductively Coupled Plasma (ICP).
The polycarbonate resin (A) of the present invention is usually cooled and solidified after melt polymerization as described above, and pelletized with a rotary cutter or the like.

  The method of pelletization is not limited. For example, the polycarbonate resin (A) is extracted from the final polymerization reactor in a molten state, cooled and solidified in the form of a strand, and pelletized, and melted from the final polymerization reactor. The resin is supplied to a single-screw or twin-screw extruder in a state, melt-extruded, and then cooled and solidified to be pelletized, or extracted from the final polymerization reactor in a molten state, and cooled and solidified in the form of a strand once. Examples of the method include a method of supplying the resin again to the single-screw or twin-screw extruder after being pelletized, melt-extruding, and then cooling and solidifying to pelletize.

At that time, in the extruder, the residual monomer under reduced pressure devolatilization, and generally known heat stabilizers, neutralizers, UV absorbers, mold release agents, colorants, antistatic agents, lubricants, lubricants, A plasticizer, a compatibilizer, a flame retardant, etc. can be added and kneaded.
The melt kneading temperature in the extruder depends on the glass transition temperature and molecular weight of the polycarbonate resin (A), but is usually 150 to 300 ° C, preferably 200 to 270 ° C, and more preferably 230 to 260 ° C. When the melt kneading temperature is lower than 150 ° C., the melt viscosity of the polycarbonate resin (A) is high, the load on the extruder is increased, and the productivity is lowered. When the temperature is higher than 300 ° C., the thermal degradation of the polycarbonate becomes severe, which causes a decrease in mechanical strength due to a decrease in molecular weight, coloring, generation of gas, generation of foreign matters, and further generation of burns. It is preferable to install a filter for removing the foreign matters and burns in the extruder or at the outlet of the extruder.

  The size of the filter for removing foreign matter (aperture) is usually 400 μm or less, preferably 200 μm or less, particularly preferably 100 μm or less, with the goal of filtering accuracy of removing 99% or more of foreign matter. If the opening of the filter is excessively large, leakage may occur in the removal of foreign matters and burns, and when the polycarbonate resin (A) is molded, brittle fracture may occur. Moreover, the opening of the said filter can be adjusted according to the use of the thermoplastic resin composition of this invention. For example, when applied to film applications, the aperture of the filter is preferably 40 μm or less and more preferably 10 μm or less because of the requirement to eliminate defects.

Further, a plurality of the filters may be used in series, or a filtration device in which a plurality of leaf disk polymer filters are stacked may be used.
Moreover, when cooling and pelletizing the melt-extruded polycarbonate resin (A), it is preferable to use cooling methods, such as air cooling and water cooling. The air to be used for air cooling should be air from which foreign substances in the air have been removed in advance using a HEPA filter (a filter specified in JIS Z8112), etc., to prevent the reattachment of foreign substances in the air. desirable. More preferably, it is preferably carried out in a clean room having a higher degree of cleanliness than class 7, as defined in JIS B 9920 (2002), and more preferably higher than class 6. When using water cooling, it is desirable to use water from which metal in water has been removed with an ion exchange resin or the like, and foreign matter in water has been removed with a filter. There are various openings of the filter to be used, but a filter of 10 to 0.45 μm is preferable.

When the polycarbonate resin (A) of the present invention is produced by a melt polymerization method, one or more of a phosphoric acid compound and a phosphorous acid compound can be added during polymerization for the purpose of preventing coloring.
As the phosphoric acid compound, one or more of trialkyl phosphates such as trimethyl phosphate and triethyl phosphate are preferably used. These are preferably added in an amount of 0.0001 mol% or more and 0.005 mol% or less, more preferably 0.0003 mol% or more and 0.003 mol% or less, based on the total hydroxy compounds subjected to the reaction. preferable. When the addition amount of the phosphorus compound is less than the lower limit, the effect of preventing coloring is small, and when the addition amount is more than the upper limit, the transparency is lowered, or conversely, the coloring is promoted or the heat resistance is lowered.

  Moreover, as a phosphorous acid compound, the heat stabilizer shown below can be selected arbitrarily and used. In particular, trimethyl phosphite, triethyl phosphite, trisnonylphenyl phosphite, trimethyl phosphate, tris (2,4-di-tert-butylphenyl) phosphite, bis (2,4-di-tert-butylphenyl) One or more of pentaerythritol diphosphites can be suitably used. These phosphorous acid compounds are preferably added in an amount of 0.0001 mol% or more and 0.005 mol% or less, more preferably 0.0003 mol% or more and 0.003 mol%, based on the total hydroxy compounds subjected to the reaction. It is preferable to add below. If the addition amount of the phosphorous acid compound is less than the lower limit, the effect of preventing coloring is small, and if it is more than the upper limit, the transparency may be reduced, or conversely, the coloring may be promoted or the heat resistance may be reduced. Sometimes.

  The phosphoric acid compound and the phosphorous acid compound can be added in combination, but the addition amount in that case is the total amount of the phosphoric acid compound and the phosphorous acid compound, with respect to all the hydroxy compounds subjected to the reaction, The content is preferably 0.0001 mol% or more and 0.005 mol% or less, more preferably 0.0003 mol% or more and 0.003 mol% or less. If this addition amount is less than the lower limit, the effect of preventing coloring is small, and if it is more than the upper limit, it may cause a decrease in transparency, or conversely promote coloring or reduce heat resistance. .

In addition, the polycarbonate resin (A) produced in this manner may be blended with one or more thermal stabilizers in order to prevent a decrease in molecular weight and a deterioration in hue at the time of molding or the like. .
Examples of the heat stabilizer include phosphorous acid, phosphoric acid, phosphonous acid, phosphonic acid, and esters thereof. Specifically, triphenyl phosphite, tris (nonylphenyl) phosphite, tris ( 2,4-di-tert-butylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, monobutyl Diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,2-methylenebis (4,6-di) -Tert Butylphenyl) octyl phosphite, bis (nonylphenyl) pentaerythritol diphosphite, bis (2,4-di-tert-butylenyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tributyl phosphate, triethyl phosphate, Trimethyl phosphate, triphenyl phosphate, diphenyl monoorthoxenyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate, 4,4′-biphenylenediphosphinic acid tetrakis (2,4-di-tert-butylphenyl), dimethylbenzenephosphonate, Examples include diethyl benzenephosphonate and dipropyl benzenephosphonate. Among them, trisnonylphenyl phosphite, trimethyl phosphate, tris (2,4-di-tert-butylphenyl) phosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2 , 6-Di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite and dimethyl benzenephosphonate are preferably used.

Such a heat stabilizer can be further added in addition to the addition amount added at the time of melt polymerization. That is, after blending an appropriate amount of a phosphorous acid compound or phosphoric acid compound to obtain a polycarbonate resin (A), and further blending a phosphorous acid compound by the blending method described later, the transparency during polymerization is improved. More heat stabilizers can be blended while avoiding reduction, coloring, and heat resistance reduction, and hue deterioration can be prevented.
The content of these heat stabilizers is preferably 0.0001 to 1 part by weight, more preferably 0.0005 to 0.5 part by weight, with respect to 100 parts by weight of the polycarbonate resin (A), and 0.001 to 0. More preferred is 2 parts by weight.

<Physical properties of polycarbonate resin (A)>
The preferred physical properties of the polycarbonate resin (A) of the present invention are shown below.

(Glass-transition temperature)
The polycarbonate resin (A) of the present invention has a glass transition temperature (Tg) of less than 145 ° C. When the glass transition temperature of the polycarbonate resin (A) is too high beyond this range, the polycarbonate resin (A) is likely to be colored, and it may be difficult to improve the impact strength. In this case, it is necessary to set the mold temperature high when transferring the shape of the mold surface to the molded product during molding. For this reason, the temperature controller that can be selected may be limited, or the transferability of the mold surface may be deteriorated.

The glass transition temperature of the polycarbonate resin (A) of the present invention is more preferably less than 140 ° C, and still more preferably less than 135 ° C.
The glass transition temperature of the polycarbonate resin (A) of the present invention is usually 90 ° C. or higher, preferably 95 ° C. or higher.
As a method of setting the glass transition temperature of the polycarbonate resin (A) of the present invention to less than 145 ° C., the proportion of the structural unit (a) in the polycarbonate resin (A) is reduced or used for the production of the polycarbonate resin (A). Examples of the dihydroxy compound include a method of selecting an alicyclic dihydroxy compound having low heat resistance or reducing the proportion of structural units derived from an aromatic dihydroxy compound such as a bisphenol compound in the polycarbonate resin (A). It is done.
In addition, the glass transition temperature of polycarbonate resin (A) of this invention is measured by the method as described in the below-mentioned Example.

(Reduced viscosity)
The degree of polymerization of the polycarbonate resin (A) of the present invention is such that a mixed solvent of phenol and 1,1,2,2, -tetrachloroethane in a weight ratio of 1: 1 is used as a solvent, and the concentration of the polycarbonate resin (A) is 1.00 g. / Reduced viscosity adjusted precisely at a temperature of 30.0 ° C. ± 0.1 ° C. (hereinafter sometimes simply referred to as “reduced viscosity”) is preferably 0.45 dl /
g or more, more preferably 0.50 dl / g or more, particularly preferably 0.52 dl / g or more, but 0.70 dl / g or less, further 0.65 dl / g or less may be suitably used. is there. If the reduced viscosity of the polycarbonate resin (A) is excessively low, the mechanical strength may be weakened. If the reduced viscosity of the polycarbonate resin (A) is excessively high, the extrusion load during molding increases and excessive heat generation occurs. As a result, there may be problems such as causing thermal decomposition, exceeding the upper limit of the durability load of equipment such as an extruder and a gear pump, and the thickness accuracy of the obtained sheet-like molded product being insufficient.

[Additive for resin composition]
As described above, the polycarbonate resin (A) of the present invention can be made into the resin composition of the present invention by adding other additives within a range not impairing the spirit of the present invention.
Examples of such additives include antioxidants, acidic compounds or derivatives thereof, ultraviolet absorbers, light stabilizers, inorganic fillers, and the like. Furthermore, a nucleating agent, a flame retardant, an impact modifier, a foaming agent, and a dye / pigment that are usually used in the resin composition may be blended within a range that does not impair the spirit of the present invention.

The antioxidant is preferably at least one selected from the group consisting of phenolic antioxidants, phosphite antioxidants and sulfur antioxidants, and phenolic antioxidants and / or phosphites. More preferred are system antioxidants.
Examples of the phenolic antioxidant include pentaerythritol tetrakis (3-mercaptopropionate), pentaerythritol tetrakis (3-laurylthiopropionate), glycerol-3-stearylthiopropionate, triethylene glycol-bis [ 3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] , Pentaerythritol-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1 , 3,5-trimethyl-2 4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, N, N-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 3,5-di-tert-butyl-4-hydroxy-benzylphosphonate-diethyl ester, tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 4,4′-biphenylenediphosphinic acid tetrakis ( 2,4-di-tert-butylphenyl), 3,9-bis {1,1-dimethyl-2- [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl} And compounds such as -2,4,8,10-tetraoxaspiro (5,5) undecane.

  Among these compounds, an aromatic monohydroxy compound substituted with one or more alkyl groups having 5 or more carbon atoms is preferable. Specifically, octadecyl-3- (3,5-di-tert-butyl-4- Hydroxyphenyl) propionate, pentaerythritol-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-tert -Butyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, and the like, preferably pentaerythritol- Tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] A further preferred.

Examples of the phosphite antioxidant include triphenyl phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, Trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, bis (2,6-di-) tert-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,2-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite, bis (nonylphenyl) pentaeri Li diphosphite, bis (2,4-di -tert- butylphenyl) pentaerythritol diphosphite, and distearyl pentaerythritol phosphite.

  Among these, trisnonylphenyl phosphite, trimethyl phosphate, tris (2,4-di-tert-butylphenyl) phosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis ( 2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite is preferred, and tris (2,4-di-tert-butylphenyl) phosphite is more preferred.

  Examples of the sulfur-based antioxidant include dilauryl-3,3′-thiodipropionate, ditridecyl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, diester Stearyl-3,3′-thiodipropionate, laurylstearyl-3,3′-thiodipropionate, pentaerythritol tetrakis (3-laurylthiopropionate), bis [2-methyl-4- (3 -Laurylthiopropionyloxy) -5-tert-butylphenyl] sulfide, octadecyl disulfide, mercaptobenzimidazole, 2-mercapto-6-methylbenzimidazole, 1,1′-thiobis (2-naphthol) and the like. Among the above, pentaerythritol tetrakis (3-lauryl thiopropionate) is preferable.

  When the resin composition of the present invention contains an antioxidant, the content of the antioxidant in the resin composition of the present invention is preferably 0.001 part by weight with respect to 100 parts by weight of the polycarbonate resin (A). Or more, more preferably 0.01 parts by weight or more, particularly preferably 0.05 parts by weight or more, on the other hand, preferably 1 part by weight or less, more preferably 0.7 parts by weight or less, particularly preferably 0.5 parts by weight. It is as follows. If the content of the antioxidant is excessively small, the coloring suppression effect during molding may be insufficient. In addition, if the content of the antioxidant is excessively large, the surface appearance of the obtained three-dimensional object may be impaired due to an increase in bleed deposits on the cooling roll when forming into a sheet by extrusion molding. is there.

  Examples of acidic compounds or derivatives thereof include hydrochloric acid, nitric acid, boric acid, sulfuric acid, sulfurous acid, phosphoric acid, phosphorous acid, hypophosphorous acid, polyphosphoric acid, adipic acid, ascorbic acid, aspartic acid, azelaic acid, and adenosine phosphorus. Acid, benzoic acid, formic acid, valeric acid, citric acid, glycolic acid, glutamic acid, glutaric acid, cinnamic acid, succinic acid, acetic acid, tartaric acid, oxalic acid, p-toluenesulfinic acid, p-toluenesulfonic acid, naphthalenesulfonic acid Bronsted acids such as nicotinic acid, picric acid, picolinic acid, phthalic acid, terephthalic acid, propionic acid, benzenesulfinic acid, benzenesulfonic acid, malonic acid, maleic acid, and esters thereof.

Among these acidic compounds or derivatives thereof, sulfonic acids or esters thereof are preferable, and p-toluenesulfonic acid, methyl p-toluenesulfonate, and butyl p-toluenesulfonate are particularly preferable.
These acidic compounds or derivatives thereof can be added in the resin composition production process as compounds that neutralize the basic transesterification catalyst used in the polycondensation reaction of the polycarbonate resin (A) of the present invention.

  When the acidic compound or derivative thereof is blended in the resin composition of the present invention, the blending amount of the acidic compound or derivative thereof in the resin composition is 0.00001 part by weight or more with respect to 100 parts by weight of the polycarbonate resin (A). .1 part by weight or less, preferably 0.0001 part by weight or more and 0.1 part by weight or less. If the amount of the acidic compound or derivative thereof is excessively small, coloring may not be sufficiently suppressed during extrusion molding. Moreover, when there are too many compounding quantities of an acidic compound or its derivative (s), a resin composition may become easy to hydrolyze.

When an ultraviolet absorber or a light stabilizer is used in the resin composition of the present invention, an additive capable of absorbing light having a wavelength to be absorbed is appropriately selected, and the content thereof is 100 parts by weight of the polycarbonate resin (A). In general, it is preferably 0.01 to 5 parts by weight.
Examples of inorganic fillers include glass cut fibers, glass milled fibers, glass flakes, silicon carbide, silicon nitride, calcium silicates, gypsum, gypsum whisker and other reinforcing materials, glass powder, silica, crosslinked acrylic powder, zeolite, and firing. Anti-blocking agents such as kaolin, metal powder, metal oxide powder and metal-coated glass powder made of aluminum, titanium, iron, copper, brass, etc., carbonaceous filler such as carbon fiber, activated carbon, carbon black, graphite, pigment, dye And the like. Conventionally known aromatic polycarbonate resins containing bisphenol A as a main monomer often have a problem that decomposition of the resin under heating and melting is accelerated when a part of a metal filler or a basic filler is mixed. The polycarbonate resin (A) of the invention is extremely unlikely to cause such problems, and has an advantage that a richer design can be imparted.

  When the inorganic filler is blended in the resin composition of the present invention, the blending amount varies greatly depending on the type and required performance, but usually 0.01 parts by weight or more and 100 parts by weight with respect to 100 parts by weight of the polycarbonate resin (A). Part or less, preferably 0.01 part by weight or more and 50 parts by weight or less. When the blending amount of the inorganic filler is excessively small, the reinforcing effect is small, and when it is excessively large, the appearance tends to deteriorate.

  In addition, the resin composition of the present invention is, for example, polycarbonate within a range not significantly impairing the gist of the present invention such as low optical strain and transparency, and in a range not significantly impairing the gist of the present invention such as processability and transparency. Aromatic polycarbonate other than resin (A), aromatic polyester, aliphatic polyester, polyamide, polystyrene, polyolefin, acrylic resin, amorphous polyolefin, cyclic olefin resin, synthetic resin such as ABS, AS, polylactic acid, polybutylene succinate It can also be used as a polymer alloy by kneading with one or more of biodegradable resins such as rubber and rubber.

  Moreover, the resin composition of the present invention preferably contains at least one metal compound selected from the group consisting of a lithium compound and a metal of Group 2 of the long-period periodic table, and the content of the metal compound is The amount of metal is preferably 0.1 ppm by weight or more, more preferably 0.5 ppm by weight or more, and particularly preferably 0.7 ppm by weight or more. Further, the upper limit is preferably 20 ppm by weight, more preferably 10 ppm by weight, particularly preferably 3 ppm by weight, most preferably 1.5 ppm by weight, and most preferably 1.0 ppm by weight.

[Method for Producing Resin Composition]
The resin composition of the present invention comprises the polycarbonate resin (A) of the present invention and other ingredients such as other additives used as necessary at the same time or in any order in a tumbler, V-type blender, Nauter mixer, Banbury. It can manufacture by mixing with mixers, such as a mixer, a kneading roll, and an extruder.

[Physical properties of resin composition]
The resin composition of the present invention has a bending stress of 1.80 M measured according to JIS K7191.
The deflection temperature under load at Pa is preferably 70 ° C. or more from the viewpoint of heat resistance requirements for this application. Moreover, it is preferable that it is 130 degrees C or less from the point which the temperature conditions of a shaping | molding process do not need to become high too much. As a minimum of this deflection temperature under load, 75 ° C or more is more preferred, and 80 ° C or more is still more preferred. Moreover, as an upper limit, 125 degrees C or less is more preferable.

[Front protective panel]
<Physical properties / characteristics>
The front protective panel of the present invention includes various image display devices such as a large television, a monitor of a computer terminal, a monitor of an in-vehicle car navigation system, a control touch panel for in-vehicle or low-power devices, a tablet-type portable display, a portable smartphone, etc. Can be suitably used as a front protective panel.
The front protective panel made of the resin composition of the present invention contributes to weight reduction, thickness reduction, and high designability compared to a conventionally known glass plate panel.

Furthermore, the front protective panel of the present invention may be provided with various functional coatings such as a hard coat, antireflection, fingerprint adhesion prevention and fogging prevention on the front side as necessary, or a picture frame which is visually recognized as a display frame on the back side. Printing. The resin composition of this invention is excellent also in adhesiveness with such a functional layer. Alternatively, a separate film having such a functional layer may be bonded.
The front protective panel of the present invention can be shaped by thermoforming. For example, the front protective panel is disposed on the front surface of an image display device having a convex shape on the front surface side, or has a shape that wraps around the end of the image display device. It is also possible to arrange panels.

<Manufacturing method>
The front protective panel of the present invention uses a sheet obtained by molding the resin composition used in the present invention according to a conventional method, and the production method of the molded sheet is preferably a T-die molding method or an inflation molding method. The melt extrusion molding method is particularly preferable, and the T-die molding method is particularly preferable.
The front protection panel of the present invention is on the front surface of the image display device, and the displayed image should not be visually recognized as being damaged by defects or distortion. For this reason, when forming into a sheet by the melt extrusion molding method, there are very few defects of foreign matters derived from the resin such as gels, bubbles, and burns, and the thickness is uniform in the flow direction and the width direction, and optical such as local phase difference. It is required that there is no distortion.

  The resin temperature at the time of melt extrusion molding is usually 150 to 265 ° C, preferably 200 ° C to 260 ° C, particularly preferably 210 ° C to 250 ° C. When the temperature is lower than the above temperature, the melt viscosity is too high and the extrusion load tends to be high. On the other hand, when the temperature is higher than the above temperature, at least the polycarbonate resin of the present invention in the resin composition starts to thermally decompose, and there is a tendency that deterioration phenomena such as coloring and viscosity decrease occur.

  Resin extrusion is rectified by controlling the resin temperature so that the melt viscosity is suitable for molding, and by mutually feedback controlling the feed rate of the raw material feeder, the screw rotation speed of the extruder, the liquid feed rate of the gear pump, etc. Thus, the thickness accuracy in the width direction of the sheet can be increased. The preferred thickness accuracy in the width direction varies depending on the required physical properties for each application, but is usually within ± 10%, preferably within ± 5%, particularly preferably within ± 3%.

  The thickness measurement in the width direction is evaluated at each measurement point when there is a traverse type continuous thickness measuring machine in the line for continuous film formation. When off-line measurement is performed with a cut film, the evaluation is based on the point measured with a dial gauge thickness meter or the like at intervals of 50 mm in the width direction. Here, since both ends of the extruded sheet are thickened due to neck-in or the like, the evaluation is performed in the range in the width direction excluding a portion that is slit and discarded.

If there is an optical distortion such as a phase difference in the width direction in the sheet, the display image may appear distorted, or when an image is observed through polarized sunglasses or the like, an iris pattern may be visually recognized and image quality may be impaired.
In order to eliminate this, it is necessary not only to increase the thickness accuracy in the width direction but also to rectify the resin over the entire width so that stress applied to the resin does not occur locally. Maintaining and managing the molten resin flow path surface so that there are no scratches, deposits, or other irregularities, attaching a release agent to the lip surface of the T-die, increasing the resin temperature as much as possible without causing resin degradation, In addition, by controlling the extrusion speed so that the resin pressure does not increase, or by providing a stirring structure such as a static mixer or a thermogenizer before the T die, local stress generation can be suppressed. The preferred optical distortion accuracy in the width direction is usually within ± 10%, preferably within ± 5%, particularly preferably within ± 3% in in-plane retardation.

In-plane retardation measurement in the width direction is evaluated at each measurement point when there is a traverse type continuous phase difference measuring machine capable of measuring a low phase difference in a continuous film forming line. When performing off-line measurement with a cut film, evaluation is made based on the points measured with a phase difference measuring machine at intervals of 50 mm in the width direction. At this time, similarly to the thickness evaluation, the evaluation is performed in the range in the width direction excluding the portion to be discarded after being slit.
The cooling roll temperature is usually 20 to 150 ° C, preferably 40 to 140 ° C, and particularly preferably 60 to 130 ° C. When the cooling roll temperature is lower than the above temperature, gear marks are generated on the sheet surface, or local optical distortion unevenness is remarkable. On the other hand, when the temperature is higher than the above temperature, the extruded sheet is difficult to peel from the cooling roll, and there is a tendency that a peeling mark is generated or the roll is contaminated.

  Although the thickness of the sheet depends on the design of the image display device, it is usually 50 to 300 μm, preferably 80 to 250 μm, from the viewpoint of an appropriate front surface protection function, light transmittance in the thickness direction, shape maintenance under a humid heat environment, and the like. Especially preferably, it is 100-200 micrometers. If the thickness is smaller than the above thickness, the image display panel cannot be sufficiently protected from the impact from the front side, and may be deformed when placed in a humid heat environment. On the other hand, when it is thicker than the above-mentioned thickness, it is difficult to obtain the effect of reducing the weight as a member, and problems such as a decrease in light transmittance in the thickness direction may occur.

  The front protective panel of the present invention preferably has a hard coat treatment on at least one side. By increasing the surface hardness, it becomes difficult to get hit points and scratches, and the performance as a protective panel is improved. A conventionally well-known hard-coating agent used for a process can be used, and is not specifically limited. For example, an acrylic type, urethane type, polyester type, rubber type, silicone type, vinyl type or the like can be exemplified, and a plurality of them may be mixed and used. The curing method of the coating agent may be an energy ray curable coating agent or a thermosetting coating agent. Moreover, in order to further improve hardness and lubricity, particles of an organic compound or an inorganic compound may be blended.

A conventionally well-known processing method can be used and is not particularly limited. Examples of the coating method for applying the coating agent include a line coating method and a wet coating method. The wet coating method is preferable in consideration of productivity, and among them, a roll coating method, a spin coating method, a dip coating method, and the like are preferable.
In order to further improve the adhesion between the resin sheet serving as the substrate and the hard coat layer, the surface of the resin sheet can be subjected to corona discharge treatment, plasma discharge treatment, or the like as necessary. Alternatively, a primer suitable for the coating agent to be used may be applied as a base treatment. When the image display apparatus is used for applications where the touch panel or the like is frequently touched, it is particularly preferable to perform a hard coat process.

The application of the hard coat layer may be a method in which a separate film that has been subjected to a hard coat treatment is bonded to the sheet used in the present invention. From the viewpoint of transparency, surface hardness, mechanical strength, versatility, and the like, a film based on a polyester film or a triacetylcellulose film is preferably used.
The front protective panel of the present invention is preferably further coated with various functional coatings such as antireflection, fingerprint adhesion prevention and fogging prevention. These may also be applied by a conventionally known method, and may be a method in which a separately treated film is bonded to a sheet used in the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, as a front protection panel for image display apparatuses, additional values, such as flexibility maintenance when thinned, weight reduction compared with a glass plate, design provision, such as a curved surface shape, can be provided. Furthermore, the problems such as the appearance of foreign matter defects, the appearance of brittleness, and the lack of light transmittance, which are manifested when other transparent resins are applied, are greatly improved.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by a following example, unless the meaning is exceeded.
(1) Measurement of the structural unit ratio derived from each dihydroxy compound in the polycarbonate resin composition The structural unit ratio derived from each dihydroxy compound in the polycarbonate resin composition was obtained by weighing 30 mg of the polycarbonate resin composition, It was dissolved in 0.7 mL, and the solution, which was placed in a NMR tube having an inner diameter of 5 mm, was analyzed by ¹ H NMR spectrum at room temperature using a Nippon Denshi JNM-AL400 (resonance frequency 400 MHz). The structural unit ratio derived from each dihydroxy compound was determined from the signal intensity ratio based on the structural unit derived from each dihydroxy compound.

(2) Sheeting by melt film forming method Using a melt extrusion film forming machine in which a co-directional twin-screw extruder equipped with a vacuum suction pipe, a gear pump, a polymer filter, and a T-die are sequentially connected, a sheet having a width of about 1400 mm is taken up. A sheet with a width of 1000 to 1200 mm was collected by slitting the neck-in portions at both ends. A thermogenizer was provided in the flow path between the polymer filter and the T die.
The extrusion temperature was adjusted in 220-255 ° C. However, the measurement temperature of the thermometer installed on the inner wall of the conduit was not allowed to exceed 265 ° C.

After raising to a predetermined discharge amount, feedback control was performed while synchronizing the discharge amount of the raw material feeder and the rotation speed of the extruder so that the resin pressure on the gear pump inlet side was within a certain range.
The cooling roll temperature was adjusted in the range of 70 to 130 ° C., and a sheet was collected between the gear mark generation condition and the release mark generation condition.
When the sheet was continuously collected and wound up in a roll shape, a masking film made of an olefin-based coextruded film was nip-laminated on one side and wound up. Thus, a sheet having a thickness of 50 to 500 μm was obtained.
In addition, about the sheet moldability of Table 1, what was shape | molded was set to (circle), and what was not made was set to x.

(3) Measurement of sheet thickness in the width direction and in-plane retardation After being extruded, the measurement points are marked at intervals of 50 mm in the width direction of the sheet slit in the neck-in part, and the thickness is measured with a digital gauge in the vicinity. The in-plane phase difference was measured with a phase difference measuring device “KOBRA-WR” manufactured by Oji Scientific Instruments. Further, when the difference between the maximum value and the minimum value was less than 10% as the unevenness of the in-plane phase difference measurement point, it was evaluated as Δ when it was 10% or more and less than 30%, and × when it was 30% or more.

(4) Impact resistance The sheet obtained in the above (2) sheeting step was placed on a metal plate having a longitudinal width of 200 mm, a lateral width of 200 mm, and a thickness of 10 mm provided with a through hole of 60 mmΦ in the center. At this time, the center of the plate was set on the center of the through hole. Next, a metal plate having a longitudinal width of 200 mm, a lateral width of 200 mm, and a thickness of 10 mm, which was similarly provided with a through hole of 60 mmΦ at the center, was overlaid thereon. Each of the two metal plates is provided with bolt holes for positioning and fixing at the four corners. The resin plate was fixed by passing a bolt through this bolt hole and tightening with the nut on the opposite side. Next, an iron ball having a weight of 150 g was dropped from a predetermined height at the center of the resin plate to evaluate the impact resistance. The falling ball test from a predetermined height was performed five times for one resin while the resin plate was replaced with an unused one each time. In addition, the test was performed so that the iron ball bounced after hitting the resin plate would not hit again.

In the above test, the impact resistance of the resin that did not break even after a 50cm height drop ball test was evaluated as ○, and the 50cm height drop ball test failed, but the 30cm height drop ball test failed once. The impact resistance of the resin that did not occur was Δ, and the impact resistance of the resin that failed in the falling ball test with a height of 30 cm was ×.
On the other hand, the impact resistance was not evaluated for the resin in which the resin plate could not be obtained due to the short shot in the above (3) evaluation of moldability (thickness 0.7 mm).

(5) Light transmittance The sheet obtained in the above (2) sheeting step is measured in accordance with JIS K 7105, and the light transmittance is measured with a D65 light source by a haze meter (Nippon Denshoku Industries Co., Ltd .: NDH2000). It was measured. 90% or more of the light transmittance is acceptable.

(6) Pencil Hardness Pencil hardness was measured at a load of 750 g, a measurement speed of 30 mm / min, and a measurement distance of 7 mm in accordance with JIS-K5600 using a test piece having a thickness of 3 mm. The pencil hardness is preferably F or higher, and more preferably H or higher. When the pencil hardness is HB or less, the obtained molded product is likely to be damaged and the appearance may be easily damaged. The pencil hardness is expressed in the order of 4H, 3H, 2H, H, F, HB, B, 2B, 3B, and 4B from the hardest. The surface hardness was evaluated by measuring the pencil hardness of the molded products according to the examples and comparative examples. A surface hardness of HB or higher is acceptable.

(7) Moisture and heat resistance The obtained sheet was taken out for 96 hours after being left in a constant temperature and humidity apparatus adjusted to a temperature of 60 ° C. and a relative humidity of 75%, and the presence or absence of a shape change was confirmed. In addition, the resin sheet was installed in the sample shelf which consists of a net-like metal in a constant temperature and humidity apparatus.
The moisture and heat resistance of the resin that does not change its shape. ○ The moisture and heat resistance of the resin in which the edge of the resin sheet is lifted by 1 mm or more and less than 5 mm when the resin sheet after the wet heat test is installed horizontally on a flat surface. Δ, when the resin sheet after the wet heat test was placed horizontally on a flat surface, the end of the resin sheet was lifted by 5 mm or more, or the resin sheet was deformed and the original shape was not retained. .

The abbreviations of the compounds used in the description of the following examples are as follows.
(Dihydroxy compound)
・ ISB: Isosorbide (Rocket Fleure, trade name: POLYSORB)
CHDM: 1,4-cyclohexanedimethanol (manufactured by Shin Nippon Rika Co., Ltd., trade name: SKY CHDM)
-TCDDM: TCDDM: Tricyclodecane dimethanol (manufactured by OXEA)
(Carbonated diester)
・ DPC: Diphenyl carbonate (Mitsubishi Chemical Corporation)
(Heat stabilizer)
AS2112: Compound name, tris (2,4-di-t-butylphenyl) phosphite (
Made by ADEKA)
(Antioxidant)
IRGANOX 1010: Compound name, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (manufactured by BASF Japan)
(Aromatic polycarbonate resin)
NOVAREX 7022R: aromatic polycarbonate resin having a structure derived only from bisphenol-A (manufactured by Mitsubishi Engineering Plastics)
(acrylic resin)
・ ACRYPET VH (Mitsubishi Rayon Co., Ltd.)
(Cyclic olefin resin)
・ TOPAS 5013L-10 (Polyplastics)

[Example 1]
In a polymerization reactor equipped with a stirring blade and a reflux condenser controlled at 100 ° C., ISB and CHDM, DPC and calcium acetate monohydrate having a chloride ion concentration of 10 ppb or less by purification by distillation, in a molar ratio. ISB / CHDM / DPC / calcium acetate monohydrate = 0.50 / 0.50 / 1.00 / 1.3 × 10 ⁻⁶ , and sufficiently purged with nitrogen (oxygen concentration 0.0005 vol% -0.001 vol%). Subsequently, heating was performed with a heating medium, and stirring was started when the internal temperature reached 100 ° C., and the contents were melted and made uniform while controlling the internal temperature to be 100 ° C. After that, temperature increase was started, the internal temperature was adjusted to 210 ° C. in 40 minutes, and when the internal temperature reached 210 ° C., control was performed so as to maintain this temperature, and at the same time, pressure reduction was started and the temperature reached 210 ° C. After 90 minutes, the pressure was changed to 13.3 kPa (absolute pressure, the same applies hereinafter), and the pressure was maintained for another 60 minutes. The phenol vapor produced as a by-product with the polymerization reaction is led to a reflux condenser using a steam controlled at 100 ° C. as the inlet temperature to the reflux condenser, and a monomer component contained in the phenol vapor in a slight amount is introduced into the polymerization reactor. Then, the phenol vapor that did not condense was recovered by guiding it to a condenser using 45 ° C. warm water as a refrigerant.

  The content thus oligomerized is once restored to atmospheric pressure, and then transferred to another polymerization reaction apparatus equipped with a stirring blade and a reflux condenser controlled in the same manner as described above. The internal temperature was set to 220 ° C. and the pressure was set to 200 Pa in 60 minutes. Thereafter, the internal temperature was set at 228 ° C. and the pressure at 133 Pa or less over 20 minutes, and when the predetermined stirring power was reached, the pressure was restored, and a molten polycarbonate resin was obtained from the outlet of the polymerization reactor. The reduced viscosity of this polycarbonate resin was 0.625 dL / g.

  Further, the molten polycarbonate resin was continuously supplied to a twin screw extruder equipped with 3 vents and water injection equipment, and “IRGANOX 1010” was 0.1 parts by weight and “AS2112” was 0.05 parts by weight. While continuously adding, low-molecular weight substances such as phenol were devolatilized under reduced pressure at each vent section provided in the twin-screw extruder, and pelletized by a pelletizer to obtain pellets of a polycarbonate resin composition.

The pellets of the polycarbonate resin composition were continuously fed to a twin screw extruder with a vent and extruded from a T die into a sheet via a gear pump and a polymer filter. While adjusting the lip interval of the T die and the rotation speed of the cooling roll so as to obtain a predetermined thickness, the sheet was formed to have a thickness of about 150 μm.
Table 1 shows various evaluation results of the obtained resin composition as a front protective panel for an image display device.

[Example 2]
In Example 1, except that the charge composition was changed to ISB / CHDM / DPC / calcium acetate monohydrate = 0.70 / 0.30 / 1.00 / 1.3 × 10 ⁻⁶ In the same manner as in Example 1, a sheet molded body of a carbonate copolymer resin composition was obtained.
[Example 3]
In Example 1, except that the charge composition was changed to ISB / CHDM / DPC / calcium acetate monohydrate = 0.85 / 0.15 / 1.00 / 1.3 × 10 ⁻⁶ In the same manner as in Example 1, a sheet molded body of a carbonate copolymer resin composition was obtained.

[Example 4]
In Example 1, except that the charged composition was changed to ISB / TCDDM / DPC / calcium acetate monohydrate = 0.70 / 0.30 / 1.00 / 1.3 × 10 ⁻⁶ In the same manner as in Example 1, a sheet molded body of a carbonate copolymer resin composition was obtained.

[Example 5]
In Example 1, except that the charged composition was changed so that ISB / TCDDM / DPC / calcium acetate monohydrate = 0.80 / 0.20 / 1.00 / 1.3 × 10 ⁻⁶ In the same manner as in Example 1, a sheet molded body of a carbonate copolymer resin composition was obtained.
[Example 6]
In Example 1, a sheet molded body of a carbonate copolymer resin composition was obtained in the same manner as in Example 1 except that the stirring power when returning pressure was changed. The reduced viscosity of this polycarbonate resin was 0.567 dL / g.

[Example 7]
In Example 1, a sheet molded body of a carbonate copolymer resin composition was obtained in the same manner as in Example 1 except that the stirring power when returning pressure was changed. The reduced viscosity of this polycarbonate resin was 0.515 dL / g.

[Comparative Example 1]
In Example 1, except that the charged composition was changed to ISB / CHDM / DPC / calcium acetate monohydrate = 0.30 / 0.70 / 1.00 / 1.3 × 10 ⁻⁶ In the same manner as in Example 1, a sheet molded body of a carbonate copolymer resin composition was obtained.

[Comparative Example 2]
In Example 1, a sheet molded body was obtained in the same manner as in Example 1 except that the sheet molding material was changed to a commercially available aromatic polycarbonate resin, NOVAREX 7022R.

[Comparative Example 3]
In Example 1, a sheet molded body was obtained in the same manner as in Example 1 except that the sheet molding material was changed to a commercially available acrylic resin, ACRYPET VH.

[Comparative Example 4]
In Example 1, a sheet molding was obtained in the same manner as in Example 1 except that the sheet molding material was changed to a commercially available cyclic olefin resin, TOPAS 5013L-10.

As the front protective panel for an image display device, a panel that does not have an item of x or reject is suitable for all the items of each characteristic evaluation described above.
Inventive examples shown in Examples 1 to 7 are not only sheet formability, but also necessary for a front protective panel for an image display device, in terms of in-plane retardation, impact resistance, light transmittance, pencil hardness, constitution heat resistance, etc. Both have excellent performance.

Among them, Examples 1, 6 and 7 are particularly excellent from the viewpoint of sheet formability, Examples 2 and 4 are performance balance, Examples 3 to 5 are pencil hardness, and Examples 4 and 5 are low in-plane retardation. Yes.
On the other hand, in Comparative Example 1, the composition ratio of the structure derived from the structural unit (a) was too low, and the pencil hardness and wet heat resistance were insufficient.
Comparative Example 2 is a sheet using a commercially available aromatic polycarbonate resin, but the in-plane retardation value and its unevenness were large, and the pencil hardness was low. Although the comparative example 3 is a sheet | seat using a commercially available acrylic resin, impact resistance and heat-and-moisture resistance were inadequate. Although the comparative example 4 is a sheet | seat using a commercially available cyclic olefin resin, many gel-like transparent foreign materials were visually recognized on the sheet | seat front surface, and the satisfactory sheet molded object was not obtained.

  The front protective panel for an image display device comprising the resin composition containing the polycarbonate resin of the present invention has little damage loss in the processing step because the brittleness does not stand out even if it is thinned. In comparison, it can be reduced in weight as a member, and can also be provided with a design property such as a curved surface shape that cannot be achieved with a glass plate, so that a further function can be imparted to the front protective panel for an image display device.

Claims (5)

A structural unit (a) derived from a dihydroxy compound having a structure represented by the following general formula (1), and a structural unit (b) derived from another dihydroxy compound,
A front protective panel for an image display device comprising a resin composition containing a polycarbonate resin in which the proportion of the structural unit (a) in the total structural units of the dihydroxy compound constituting the polycarbonate resin is 40 mol% or more.

The structural unit (b) in the polycarbonate resin is any structural unit selected from the group consisting of structural units derived from dihydroxy compounds represented by the following formulas (2) to (5). The front protective panel for an image display device according to claim 1.
HO—R ¹ —OH (2)
(In formula (2), R ¹ represents a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms.)
HO—CH ₂ —R ² —CH ₂ —OH (3)
(In formula (3), R ² represents a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms.)
H- (O-R < ³ >) _p- OH (4)
(In Formula (4), R ³ represents a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, and p is an integer of 2 to 100.)
^HO-R 4 -OH (5)
(In formula (5), R ⁴ represents a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms, or a group having a substituted or unsubstituted acetal ring.) The resin composition according to claim 1 or 2, wherein the proportion of the structural unit (a) in the total structural units of the dihydroxy compound constituting the polycarbonate resin is 90 mol% or less.   The resin composition according to any one of claims 1 to 3, wherein the reduced viscosity of the polycarbonate resin is 0.45 dl / g or more. 5. The front protective panel for an image display device according to claim 1, obtained by extrusion molding the resin composition to a thickness of 50 μm to 300 μm by a melt film forming method.