JP6715571B2 - Film made of polycarbonate resin composition - Google Patents

Description

The present invention relates to a film made of a polycarbonate resin composition.

Conventionally, optical films such as polarizing plates provided in liquid crystal displays include resins such as triacetyl cellulose (hereinafter sometimes referred to as TAC), polyester, cycloolefin polymer (hereinafter sometimes referred to as COP), and the like. Films based on have been used exclusively.
Due to recent technological development trends such as thinner, larger, and more flexible displays, such optical films are required to have characteristics such as dimensional stability at higher temperatures, thin film processability, and low optical distortion. However, there are cases in which the physical properties of the conventional film cannot be satisfied.

Under such circumstances, a method has been proposed in which isosorbide, which is a dihydroxy compound obtained from a biomass resource, is used as a main monomer component, and transesterification with a carbonic acid diester is performed to distill off a by-produced monohydroxy compound under reduced pressure to obtain a polycarbonate resin. (Patent documents 1 and 2).
Dihydroxy compounds such as isosorbide have lower thermal stability than dihydroxy compounds of bisphenols, which have been used exclusively for conventionally known aromatic polycarbonate resins, and have a polycondensation reaction at high temperatures and retention thermal decomposition during molding. There was a problem that the resin was colored by the end. In order to solve this problem, improvement of the reaction mechanism and catalyst, and improvement by adding various stabilizers to the resin have been studied (Patent Documents 3 to 6).

International Publication No. 2004/111106 Pamphlet International Publication No. 2007/63823 Pamphlet JP, 2009-161745, A International Publication No. 2011/65505 Pamphlet JP, 2009-91405, A JP, 2009-144020, A

The inventors of the present invention have prepared a film made of a polycarbonate resin using the above isosorbide, etc., and have investigated the use as various optical films, but the resin film has a very large surface friction resistance, for example, a roll shape. When it is attempted to obtain a wound layer body, it is difficult to smoothly wind the film due to lack of lubricity between the film surfaces, or it is taken up and conveyed in the film pass line, and secondary processing such as lamination and coating is performed. It was found that sometimes problems such as transport scratches on the surface frequently occur.

As a simple method of providing surface lubricity when handling the film, a method of pressure-bonding and laminating a polyolefin-based masking film having an adhesive surface layer on at least one side is known. There is a possibility that the winding amount of the layered body may be shortened, various adhesive defects may remain on the film when the masking film is peeled off in the next step, and peeling scratches may be formed on the film. ..

Therefore, the present inventors conducted a study to improve the surface slipperiness by reducing the contact area between the film surfaces by providing unevenness at least near the surface layer of the film. However, it was found that the thermal decomposition of the resin may be accelerated or the haze of the film may be significantly increased depending on the added particle component.
In particular, a film using a conventionally used polyester or aromatic polyester has a high processing temperature of about 270° C. or higher. Therefore, usable particle components have been limited to inorganic particles such as glass particles, acrylic particles having extremely high crosslink density, and melamine/formaldehyde condensate particles.

In the case of inorganic particles, there are problems that the film forming equipment is damaged and that it cannot be incinerated when discarded. Further, in the case of organic particles, it is difficult to adjust the refractive index because there are limited options, and it is difficult to form a film having excellent transparency.
The present invention has been made in view of such a background, a film made of a polycarbonate resin using isosorbide or the like, containing specific particles, by imparting surface smoothness without impairing transparency, roll-like The purpose of the present invention is to obtain a wound layer body smoothly and reduce transport scratches when handling a film.

As a result of intensive studies to solve the above problems, the present inventors have found that the following films sufficiently satisfy the required quality, and have completed the present invention.
That is, the gist of the present invention lies below.
[1] A film made of a resin composition containing a polycarbonate resin,
The polycarbonate resin comprises a structural unit (a) derived from a dihydroxy compound represented by the following general formula (1), an aliphatic hydrocarbon dihydroxy compound, an alicyclic hydrocarbon dihydroxy compound, and an ether-containing dihydroxy compound. A copolymer containing a structural unit (b) derived from one or more selected dihydroxy compounds,
A film in which the resin composition contains a crosslinked poly(meth)acrylic acid ester.

[2] The film according to [1], wherein the particle concentration in the film is 500 ppm or more.
[3] The film according to [1] or [2], wherein the crosslinked poly(meth)acrylic acid ester has an average particle size of 1 μm or more and 5 μm or less.
[4] The film according to any one of [1] to [3], wherein the crosslinked poly(meth)acrylic acid ester has a refractive index of 1.49 or more and 1.53 or less.
[5] The film according to any one of [1] to [4], wherein the particles are crosslinked polymethylmethacrylate particles.
[6] The film according to any one of [1] to [5], wherein the polycarbonate resin is a polycarbonate resin using a Group 2 metal compound as a transesterification reaction catalyst.

The film of the present invention is composed of a resin composition containing a copolycarbonate resin containing the structural units (a) and (b), has a low haze as a film, is excellent in surface smoothness, and has a film appearance. It is a good film. Therefore, it contributes to amelioration of problems such as smoothly obtaining a roll-shaped wound layer body without attaching a masking film or the like and reducing transport scratches when handling the film.

Further, by containing specific particles, it can be used in various optical film applications in the process without impairing the transparency and optical properties of the film.

Embodiments of the present invention will be described in detail below, but the constituent elements described below are examples of the aspects of the present invention, and the present invention is not limited to the following contents unless the gist thereof is exceeded.

[Polycarbonate resin]
As described above, the film using the conventionally used polyester or aromatic polyester has a high processing temperature of about 270° C. or higher. Therefore, usable anti-blocking agents have been limited to inorganic particles such as glass particles, acrylic particles having extremely high crosslink density, and melamine-formaldehyde condensate particles.

A polycarbonate resin having the following features of the present invention, which can be melt-processed at a low temperature of, for example, about 250° C. or lower. Therefore, crosslinked poly(meth)acrylic acid ester particles whose refractive index can be freely adjusted can be selected and used.
Hereinafter, the polycarbonate resin used in the present invention will be described in detail.

(Structural unit)
The polycarbonate resin is selected from the group consisting of a structural unit (a) derived from a dihydroxy compound represented by the following general formula (1), an aliphatic hydrocarbon dihydroxy compound, an alicyclic hydrocarbon dihydroxy compound and an ether-containing dihydroxy compound. It is a copolymer essentially containing the structural unit (b) derived from one or more selected dihydroxy compounds. Examples of the dihydroxy compound represented by the above formula (1) include isosorbide, isomannide and isoidide, which are stereoisomeric. These may be used alone or in combination of two or more.

Among the dihydroxy compounds represented by the general formula (1), isosorbide obtained by dehydration condensation of sorbitol produced from various starches, which is abundant as a plant-derived resource and is easily available, is available. It is most preferable in terms of easiness of production, light resistance, optical characteristics, moldability, heat resistance and carbon neutral.
In addition, the polycarbonate resin of the present invention requires a structural unit (b) derived from one or more dihydroxy compounds selected from the group consisting of an aliphatic hydrocarbon dihydroxy compound, an alicyclic hydrocarbon dihydroxy compound and an ether-containing dihydroxy compound. Included in. These dihydroxy compounds do not have an aromatic group and are blended in order to suitably design the flexibility, optical isotropy, heat resistance, rigidity and the like of the polycarbonate resin. Depending on the desired performance, it is preferable to use an aliphatic hydrocarbon dihydroxy compound or an alicyclic hydrocarbon dihydroxy compound, and it is most preferable to use an alicyclic hydrocarbon dihydroxy compound from the viewpoint of performance balance. Specific examples of these dihydroxy compounds are as follows.

As the aliphatic hydrocarbon dihydroxy compound, for example, the following dihydroxy compounds can be adopted. Ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,5-heptanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decane Linear aliphatic dihydroxy compounds such as diols and 1,12-dodecanediols; aliphatic dihydroxy compounds having branched chains such as 1,3-butanediol, 1,2-butanediol, neopentyl glycol and hexylene glycol.

As the alicyclic hydrocarbon dihydroxy compound, for example, the following dihydroxy compounds can be adopted. 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, tricyclodecanedimethanol, pentacyclopentadecanedimethanol, 2,6-decalindimethanol, 1,5-decalindim Examples are dihydroxy compounds derived from terpene compounds such as methanol, 2,3-decalindimethanol, 2,3-norbornanedimethanol, 2,5-norbornanedimethanol, 1,3-adamantanedimethanol and limonene. A dihydroxy compound which is a primary alcohol of alicyclic hydrocarbon; 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,3-adamantanediol, hydrogenated bisphenol A, 2,2,4,4- A dihydroxy compound which is a secondary alcohol or tertiary alcohol of an alicyclic hydrocarbon, such as tetramethyl-1,3-cyclobutanediol.

Examples of the ether-containing dihydroxy compound include oxyalkylene glycols and dihydroxy compounds containing an acetal ring.
As the oxyalkylene glycols, for example, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, polypropylene glycol and the like can be adopted.

As the dihydroxy compound containing an acetal ring, for example, spiroglycol represented by the following structural formula (2), dioxane glycol represented by the following structural formula (3), or the like can be adopted.

Further, the polycarbonate resin may further include a structural unit other than the structural units (a) and (b). As the dihydroxy compound into which the structural unit can be introduced, for example, a dihydroxy compound containing an aromatic group can be adopted. However, when the polycarbonate resin contains a structural unit derived from an aromatic group-containing dihydroxy compound, the polycarbonate resin may be easily discolored to yellow by irradiation with sunlight or UV light. In the following, dihydroxy compounds other than the dihydroxy compound represented by the general formula (1) may be collectively referred to as other dihydroxy compounds.

As the dihydroxy compound containing an aromatic group, for example, the following dihydroxy compounds can be adopted, but dihydroxy compounds other than these can also be adopted. 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2 ,2-bis(4-hydroxy-3,5-diethylphenyl)propane, 2,2-bis(4-hydroxy-(3-phenyl)phenyl)propane, 2,2-bis(4-hydroxy-(3,3 5-diphenyl)phenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2 ,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)pentane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, bis(4-hydroxyphenyl)diphenylmethane , 1,1-bis(4-hydroxyphenyl)-2-ethylhexane, 1,1-bis(4-hydroxyphenyl)decane, bis(4-hydroxy-3-nitrophenyl)methane, 3,3-bis( 4-hydroxyphenyl)pentane, 1,3-bis(2-(4-hydroxyphenyl)-2-propyl)benzene, 1,3-bis(2-(4-hydroxyphenyl)-2-propyl)benzene, 2 ,2-bis(4-hydroxyphenyl)hexafluoropropane, 1,1-bis(4-hydroxyphenyl)cyclohexane, bis(4-hydroxyphenyl)sulfone, 2,4′-dihydroxydiphenylsulfone, bis(4-hydroxy) Phenyl) sulfide, bis(4-hydroxy-3-methylphenyl) sulfide, bis(4-hydroxyphenyl) disulfide, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dichlorodiphenyl ether, etc. Aromatic bisphenol compound; 2,2-bis(4-(2-hydroxyethoxy)phenyl)propane, 2,2-bis(4-(2-hydroxypropoxy)phenyl)propane, 1,3-bis(2-hydroxy) Dihydroxy compounds having an ether group bonded to an aromatic group such as ethoxy)benzene, 4,4′-bis(2-hydroxyethoxy)biphenyl and bis(4-(2-hydroxyethoxy)phenyl)sulfone; 9,9- Bis(4-(2-hydroxyethoxy)phenyl)fluorene, 9,9-bis(4-hydroxyphenyl)fluorene Ren, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxypropoxy)phenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy) )-3-Methylphenyl)fluorene, 9,9-bis(4-(2-hydroxypropoxy)-3-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isopropylphenyl ) Fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isobutylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-tert-butylphenyl)fluorene, 9 ,9-bis(4-(2-hydroxyethoxy)-3-cyclohexylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-phenylphenyl)fluorene, 9,9-bis(4 -(2-hydroxyethoxy)-3,5-dimethylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-tert-butyl-6-methylphenyl)fluorene, 9,9-bis A dihydroxy compound having a fluorene ring such as (4-(3-hydroxy-2,2-dimethylpropoxy)phenyl)fluorene.

The other dihydroxy compounds may be appropriately selected according to the characteristics of the target film, and may be used alone or in combination of two or more.
From the viewpoint of the balance of heat resistance, mechanical properties, optical properties, etc., the polymerization composition ratio of the structural unit (a) is preferably 40 mol% or more and 90 mol% or less, and particularly preferably 45 mol% or more and 85 mol% or less. Depending on the required characteristics, it is often most preferable that the content is 60 mol% or more and 75 mol% or less. If the polymerization composition ratio of the structural unit (a) is too low, it may be difficult to obtain sufficient heat resistance, and cut defects may occur when the strand-shaped resin is cut into pellets in the latter stage of the polymerization step. Manufacturing defects such as the above are likely to occur. On the other hand, when the compositional ratio of the structural unit (a) is too large, it may be difficult to proceed the polymerization reaction to a desired degree of polymerization, and a so-called hard and brittle resin may be obtained. As a result, the problem of use such as dimensional change easily occurs.

The dihydroxy compound used as a raw material for the polycarbonate resin of the present invention may contain a stabilizer such as a reducing agent, an antioxidant, an oxygen absorber, a light stabilizer, an antacid, a pH stabilizer or a heat stabilizer. .. In particular, the dihydroxy compound represented by the general formula (1) is easily deteriorated under acidic conditions, and therefore it is preferable to include a basic stabilizer.

(Basic stabilizer)
The dihydroxy compound represented by the general formula (1), which is essential for the polycarbonate resin, has a property of easily degrading in an acidic state. By using a basic stabilizer in the process of synthesizing the polycarbonate resin, it is possible to suppress alteration of the dihydroxy compound represented by the general formula (1), and further improve the quality of the obtained polycarbonate resin. You can

As the basic stabilizer, for example, the following compounds can be adopted. Hydroxides, carbonates, phosphates, phosphites, hypophosphites, borates and fatty acid salts of Group 1 or Group 2 metals in the Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005; Tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide, triethylmethylammonium hydroxide, triethylbenzylammonium Bases such as hydroxide, triethylphenylammonium hydroxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium hydroxide and butyltriphenylammonium hydroxide Ammonium compound; diethylamine, dibutylamine, triethylamine, morpholine, N-methylmorpholine, pyrrolidine, piperidine, 3-amino-1-propanol, ethylenediamine, N-methyldiethanolamine, diethylethanolamine, diethanolamine, triethanolamine, 4-amino Pyridine, 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 aminoquinoline amine compounds, and di-(tert-butyl)amine and 2,2,6,6-tetramethylpiperidine hindered amine compounds.

The content of the basic stabilizer in the dihydroxy compound is not particularly limited, but since the dihydroxy compound represented by the general formula (1) is unstable in an acidic state, it contains a basic stabilizer. It is preferable to set the content of the basic stabilizer so that the pH of the solution is about 7.
If the amount of the basic stabilizer is too small, the effect of preventing alteration of the dihydroxy compound represented by the general formula (1) may not be obtained. On the other hand, if the amount of the basic stabilizer is too large, the basic stabilizer may cause the modification of the dihydroxy compound. In order to avoid such problems, the content of the basic stabilizer with respect to the dihydroxy compound represented by the general formula (1) is preferably 0.0001 to 1% by mass, and 0.001 to 0.1% by mass. It is more preferable that the content be% by mass.

Further, the dihydroxy compound represented by the general formula (1) is easily oxidized gradually by oxygen. Therefore, during storage or handling during production, in order to prevent decomposition by oxygen, moisture should not be mixed. Further, it is preferable to use an oxygen scavenger or to place it in a nitrogen atmosphere.

(Carbonic acid diester)
As the carbonic acid diester used as the raw material of the polycarbonate resin, a compound represented by the following general formula (4) can be usually adopted. These carbonic acid diesters may be used alone or in combination of two or more.

In the general formula (4), A1 and A2 are each a substituted or unsubstituted aliphatic hydrocarbon group having 1 to 18 carbon atoms or a substituted or unsubstituted aromatic hydrocarbon group, and A1 and A2 are the same. Or may be different.
Of these, a substituted or unsubstituted aromatic hydrocarbon group is preferably used as A1 and A2, and an unsubstituted aromatic hydrocarbon group is more preferably used.

As the carbonic acid diester represented by the general formula (4), for example, substituted diphenyl carbonate such as diphenyl carbonate and ditolyl carbonate, dimethyl carbonate, diethyl carbonate and di-tert-butyl carbonate can be adopted. Among these carbonic acid diesters, diphenyl carbonate or substituted diphenyl carbonate is preferably used, and diphenyl carbonate is particularly preferably used.

Incidentally, the carbonic acid diester may contain impurities such as chloride ions, and the impurities may hinder the polycondensation reaction or may deteriorate the color tone of the obtained polycarbonate resin. It is preferable to use the one purified by the above method.

(Transesterification reaction catalyst)
The polycarbonate resin of the present invention is synthesized by subjecting the above-mentioned dihydroxy compound and carbonic acid diester to polycondensation by transesterification. More specifically, it can be obtained by distilling out the monohydroxy compound and the like, which is a by-product in the transesterification reaction, along with the polycondensation, to promote the reaction.

The transesterification reaction proceeds in the presence of a transesterification catalyst (hereinafter, the transesterification catalyst is referred to as a “polymerization catalyst”). The type of polymerization catalyst can greatly affect the reaction rate of the transesterification reaction and the quality of the obtained polycarbonate resin.
The polymerization catalyst is not limited as long as it can satisfy the transparency, color tone, heat resistance, weather resistance, and mechanical strength of the obtained polycarbonate resin. Examples of the polymerization catalyst include a metal compound of Group 1 or Group 2 (hereinafter simply referred to as “Group 1” or “Group 2”) of a long-periodic periodic table, a basic boron compound, and a basic phosphorus compound. A basic compound such as a compound, a basic ammonium compound and an amine compound can be used, and among them, a Group 1 metal compound and/or a Group 2 metal compound are preferable, and when used as a film of the present invention, film haze, film A Group 2 metal compound is particularly preferable because it provides a good appearance.

As the group 1 metal compound, for example, the following compounds can be adopted. 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 phenyl borohydride, phenyl borohydride Potassium, lithium phenyl boride, cesium phenyl boride, sodium benzoate, potassium benzoate, lithium benzoate, cesium benzoate, disodium hydrogen phosphate, 2 potassium hydrogen phosphate, 2 lithium hydrogen phosphate, 2 hydrogen phosphate Cesium, disodium phenylphosphate, dipotassium phenylphosphate, dilithium phenylphosphate, dicesium phenylphosphate, sodium, potassium, lithium, cesium alcoholate, phenolate, bisphenol A disodium salt, 2 potassium salt 2 lithium salt, 2 cesium salt and the like.

As the Group 1 metal compound, a lithium compound is preferable from the viewpoint of polymerization activity and the color tone of the obtained polycarbonate resin.
As the Group 2 metal compound, for example, the following compounds can be adopted. 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, etc.

As the Group 2 metal compound, from the viewpoint of polymerization activity and the color tone of the obtained polycarbonate resin, when the film of the present invention is formed, the film haze and the film appearance are improved, so that a magnesium compound, a calcium compound or a barium compound is obtained. Are preferred, magnesium compounds and/or calcium compounds are more preferred, and calcium compounds are most preferred.

It is also possible to supplementarily use a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound or an amine compound together with the group 1 metal compound and/or the group 2 metal compound. However, it is particularly preferred to use only Group 1 metal compounds and/or Group 2 metal compounds.
As the basic phosphorus compound, for example, the following compounds can be adopted. Triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tributylphosphine, quaternary phosphonium salts and the like.

As the basic ammonium compound, for example, the following compounds can be adopted. 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 and butyltriphenylammonium hydroxide.

For example, the following compounds can be adopted as the amine compound. 4-aminopyridine, 2-aminopyridine, N,N-dimethyl-4-aminopyridine, 4-diethylaminopyridine, 2-hydroxypyridine, 2-methoxypyridine, 4-methoxypyridine, 2-dimethylaminoimidazole, 2-methoxy Imidazole, imidazole, 2-mercaptoimidazole, 2-methylimidazole, aminoquinoline, guanidine and the like.

The amount of the polymerization catalyst used is, for example, preferably 0.1 to 300 μmol, more preferably 0.5 to 100 μmol, and particularly preferably 1 to 50 μmol, per 1 mol of all dihydroxy compounds used in the reaction. preferable.
When a compound containing at least one metal selected from the group consisting of Group 2 metals and lithium in the long periodic table is used as the polymerization catalyst, the amount of the polymerization catalyst used is the amount of metal atom of the compound containing the metal. Is preferably 0.1 μmol or more, more preferably 0.3 μmol or more, and particularly preferably 0.5 μmol or more per 1 mol of all dihydroxy compounds used in the reaction. The upper limit is preferably 10 μmol or less, more preferably 5 μmol or less, and particularly preferably 3 μmol or less.

When at least one metal selected from the group consisting of a Group 2 metal in the long periodic table and lithium is used as the polymerization catalyst, the polycarbonate of the present invention contains the metal used as the polymerization catalyst. Becomes The total amount of the compounds of the metal in the polycarbonate resin is usually preferably 1 mass ppm or more, more preferably 2 mass ppm or more, preferably 10 mass ppm or less, and further 5 It is preferably not more than ppm by mass.

If the amount of the polymerization catalyst used is too small, the polymerization rate will be slowed down. Therefore, in order to obtain a polycarbonate resin having a desired molecular weight, the polymerization temperature must be increased correspondingly. Therefore, the color tone of the obtained polycarbonate resin is likely to be deteriorated, and the unreacted raw material is volatilized during the polymerization to destroy the molar ratio of the dihydroxy compound and the carbonic acid diester, and thus the desired molecular weight may not be reached. There is a nature. On the other hand, if the amount of the polymerization catalyst used is too large, undesired side reactions may occur together, resulting in deterioration of the color tone of the obtained polycarbonate resin or coloring of the resin during molding.

Incidentally, among the Group 1 metals, sodium, potassium or cesium may adversely affect the color tone if they are contained in large amounts in the polycarbonate resin. Similarly, iron may adversely affect the color tone if it is contained in a large amount in the polycarbonate resin. Then, these metals may be mixed not only from the catalyst used but also from the raw material or the reaction device. Regardless of the source, the total amount of these metal compounds in the polycarbonate resin is preferably 1 mass ppm or less, more preferably 0.5 mass ppm, as the total content of sodium, potassium, cesium and iron. The following is preferable.

(Synthesis of polycarbonate resin)
The polycarbonate resin of the present invention can be obtained by polycondensing a dihydroxy compound represented by the general formula (1) and a carbonic acid diester by a transesterification reaction in the presence of a polymerization catalyst.
The dihydroxy compound and the carbonic acid diester, which are raw materials, are preferably uniformly mixed before the transesterification reaction. The mixing temperature is usually 80°C or higher, preferably 90°C or higher, and usually 250°C or lower, preferably 200°C or lower, more preferably 150°C or lower, and particularly preferably 100°C or higher and 120°C or lower. If the mixing temperature is too low, the dissolution rate may be slow or the solubility may be insufficient, which often leads to problems such as unmelting. On the other hand, if the mixing temperature is too high, the dihydroxy compound may be thermally deteriorated, resulting in deterioration of the color tone of the resulting polycarbonate resin and adversely affecting the weather resistance.

The operation of mixing the raw material dihydroxy compound and the carbonic acid diester should be performed in an atmosphere having an oxygen concentration of 10 vol% or less, more preferably 0.0001 to 10 vol%, especially 0.0001 to 5 vol%, and particularly 0.0001 to 1 vol%. However, it is preferable from the viewpoint of suppressing deterioration of color tone and deterioration of reactivity.
In order to obtain the polycarbonate resin of the present invention, it is preferable to use the carbonic acid diester in a molar ratio of 0.90 to 1.20 with respect to all dihydroxy compounds used in the reaction, and a molar ratio of 0.95 to 1.10. Is more preferably used. When this molar ratio is small, the amount of hydroxy group terminals of the produced polycarbonate resin is increased, the thermal stability of the polymer is deteriorated, coloring is caused at the time of molding, the rate of transesterification reaction is decreased, and the desired amount is obtained. High molecular weight product may not be obtained.

Further, if this molar ratio becomes large, the rate of the transesterification reaction may decrease, or it may be difficult to produce a polycarbonate resin having a desired molecular weight. A decrease in the transesterification reaction rate increases the heat history during the reaction, which may deteriorate the color tone and light resistance of the obtained polycarbonate resin. Furthermore, when the molar ratio of the carbonic acid diester to the total dihydroxy compound is increased, the amount of the residual carbonic acid diester in the obtained polycarbonate resin is increased, which may lead to problems such as stains and odor during molding, which is not preferable.

In the present invention, the method of polycondensing a dihydroxy compound and a carbonic acid diester is carried out in multiple stages using a plurality of reactors in the presence of the above-mentioned catalyst. The reaction type may be a batch type, a continuous type, or a combination of a batch type and a continuous type, but in the present invention, a polycarbonate resin can be obtained with less heat history, and the continuous type is also excellent in productivity. Is preferably used.

From the viewpoint of controlling the polymerization rate and the quality of the obtained polycarbonate resin, it is important to appropriately select the jacket temperature and the internal temperature and the pressure in the reaction system according to the reaction stage. Specifically, it is preferable to obtain the prepolymer at a relatively low temperature and low vacuum in the initial stage of the polycondensation reaction, and to increase the molecular weight to a predetermined value at a relatively high temperature and high vacuum in the latter stage of the reaction. For example, if the degree of progress of the polycondensation reaction is changed too early in either one of the temperature and the pressure before reaching a predetermined value, unreacted monomers are distilled out, and the molar ratio of the dihydroxy compound and the carbonic acid diester is increased. There is a risk of deviation from the desired ratio. As a result, the polymerization rate may be decreased, or a polymer having a predetermined molecular weight or a terminal group may not be obtained, and as a result, the object of the present invention may not be achieved.

The polymerization rate in the polycondensation reaction is controlled by the balance between the hydroxy group terminal and the carbonate group terminal. Therefore, if the balance of the terminal groups fluctuates due to the distillation of the unreacted monomer, it becomes difficult to control the polymerization rate constant, and the fluctuation of the molecular weight of the obtained resin may increase. Since the molecular weight of the resin correlates with the melt viscosity, when the obtained resin is melt processed, the melt viscosity may fluctuate and it may be difficult to keep the quality of the molded product constant. Such a problem tends to occur particularly when the polycondensation reaction is carried out continuously.

In order to suppress the amount of unreacted monomer distilled out, it is effective to use a reflux condenser in the polymerization reactor, and particularly a high effect is exhibited in the early stage of the reaction in which the amount of unreacted monomer is large. 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. It is preferably 80 to 150°C, and particularly preferably 100 to 130°C. If the temperature of the refrigerant is too high, the amount of reflux is reduced, and its effect is reduced. Conversely, if it is too low, the efficiency of distilling off the monohydroxy compound to be originally distilled is reduced, and the reaction rate is lowered and the resulting resin is colored. May be invited. As the refrigerant, hot water, steam, heat medium oil or the like is used, and steam or heat medium oil is preferable.

It is important to select the type and amount of the above-mentioned polymerization catalyst so that the polymerization rate is appropriately maintained and the distillation of the monomer is suppressed and the color tone of the final polycarbonate resin is not impaired.
The polycarbonate resin of the present invention is usually produced using a polymerization catalyst through two or more steps. The polycondensation reaction may be carried out in two or more steps by using one polycondensation reactor and sequentially changing the conditions, but from the viewpoint of production efficiency, a plurality of reactors are used and the respective conditions are changed. It is preferable to carry out in multiple stages.

From the viewpoint of efficiently carrying out the polycondensation reaction, it is important to suppress the volatilization of the monomer while maintaining the required polymerization rate in the early stage of the reaction when the reaction solution contains a large amount of the monomer. In the latter stage of the reaction, it is important to shift the equilibrium to the polycondensation reaction side by sufficiently distilling off the by-produced monohydroxy compound. Therefore, the reaction conditions suitable for the initial stage of the reaction and the reaction conditions suitable for the latter stage of the reaction are usually different. Therefore, by using a plurality of reactors arranged in series, the respective conditions can be easily changed, and the production efficiency can be improved.

As described above, the number of polymerization reactors used for producing the polycarbonate resin of the present invention may be at least two, but from the viewpoint of production efficiency, three or more, preferably 3 to 5, especially It is preferably four. In the present invention, if there are two or more polymerization reactors, the polymerization reactor may have a plurality of reaction stages under different conditions, or the temperature and pressure may be continuously changed.

In the present invention, the polymerization catalyst may be added to the raw material preparation tank or the raw material storage tank, or may be added directly to the polymerization reactor, but from the viewpoint of stability of supply, control of polycondensation reaction, polymerization reaction A catalyst supply line is installed in the middle of the raw material line before being supplied to the vessel, and the solution is preferably supplied as an aqueous solution.
If the temperature of the polycondensation reaction is too low, it may lead to a decrease in productivity and an increase in heat history to the product, and if it is too high, it may not only cause the volatilization of the monomer, but may also promote the decomposition and coloring of the polycarbonate resin. .. Specifically, the following conditions can be adopted as the reaction conditions in the first-step reaction. That is, the maximum internal temperature of the polymerization reactor is usually set in the range of 150 to 250°C, preferably 160 to 240°C, more preferably 170 to 230°C. Further, the pressure of the polymerization reactor (hereinafter, pressure means absolute pressure) is usually set in the range of 1 to 110 kPa, preferably 5 to 70 kPa, and more preferably 7 to 30 kPa. The reaction time is usually set in the range of 0.1 to 10 hours, preferably 0.5 to 3 hours. The first-step reaction is carried out while distilling the generated monohydroxy compound out of the reaction system.

After the second stage, the pressure of the reaction system is gradually reduced from the pressure of the first stage, and the monohydroxy compound that is continuously generated is removed to the outside of the reaction system while the pressure (absolute pressure) of the reaction system is finally set. Set to 1 kPa or less. The maximum internal temperature of the polymerization reactor is usually set in the range of 200 to 260°C, preferably 210 to 250°C. The reaction time is usually 0.1 to 10 hours, preferably 0.3 to 6 hours, particularly preferably 0.5 to 3 hours.

If the polymerization temperature is high and the polymerization time is too long, the color tone of the obtained polycarbonate resin tends to deteriorate. In particular, in order to suppress coloring and thermal deterioration of the polycarbonate resin and obtain a polycarbonate resin having a good color tone, it is preferable to set the maximum internal temperature of the polymerization reactor to 210 to 240° C. in all the reaction steps. Also, in order to suppress the decrease in the polymerization rate in the latter half of the reaction and minimize the deterioration due to thermal history, use a horizontal reactor with excellent plug flow and interface renewal properties at the final stage of the polycondensation reaction. Is preferred.

In continuous polymerization, in order to control the molecular weight of the finally obtained polycarbonate resin to a constant level, it is necessary to adjust the polymerization rate as needed. In that case, adjusting the pressure of the final stage polymerization reactor is a method with good operability.
Further, as described above, since the polymerization rate changes depending on the ratio of the hydroxy group end and the carbonate group end, the end group on one side is intentionally reduced to suppress the polymerization rate, and the pressure of the polymerization reactor at the final stage is reduced accordingly. By maintaining a high vacuum, it is possible to reduce the residual low molecular components in the resin including the monohydroxy compound. However, in this case, if one of the ends becomes too small, the reactivity of the resulting polycarbonate resin may be extremely decreased, and the molecular weight of the obtained polycarbonate resin may not reach the desired molecular weight, even if the end group balance is slightly changed. .. In order to avoid such a problem, it is preferable that the polycarbonate resin obtained in the polymerization reactor at the final stage contains 10 mol/ton or more of both hydroxy group terminals and carbonate group terminals. On the other hand, if both end groups are too much, the polymerization rate will be too fast and the molecular weight will be too high. Therefore, it is preferable that one end group is 60 mol/ton or less.

In this way, by adjusting the amount of the terminal groups and the pressure of the polymerization reactor at the final stage within the preferable range, the residual amount of the monohydroxy compound in the resin can be reduced at the outlet of the polymerization reactor. The residual amount of the monohydroxy compound in the resin at the outlet of the polymerization reactor is preferably 2000 mass ppm or less, more preferably 1500 mass ppm or less, and further preferably 1000 mass ppm or less. As described above, by reducing the content of the monohydroxy compound at the outlet of the polymerization reactor, the devolatilization of the monohydroxy compound or the like can be easily performed in the subsequent step.

It is preferable that the residual amount of the monohydroxy compound is small, but if it is attempted to reduce the amount to less than 100 mass ppm, the operating conditions such that the amount of one end group is extremely reduced and the pressure of the polymerization reactor is kept in a high vacuum is required. Need to take. In this case, as described above, it is difficult to maintain the molecular weight of the obtained polycarbonate resin at a constant level, and therefore, it is often at least 100 mass ppm or more, and usually 150 mass ppm or more.

From the viewpoint of effective utilization of resources, it is preferable that the by-produced monohydroxy compound be purified as necessary and then reused as a raw material for other compounds. For example, when the monohydroxy compound is phenol, it can be used as a raw material for diphenyl carbonate, bisphenol A, or the like.

[Resin composition containing polycarbonate resin]
The resin composition of the present invention can be produced by adding various additives to the polycarbonate resin. Examples of the additives include catalyst deactivators, dyes and pigments, UV absorbers, light stabilizers, flame retardants, flame retardant aids, inorganic fillers, impact modifiers, hydrolysis inhibitors, foaming agents, nucleating agents, etc. Additives commonly used in polycarbonate resins can be used.

(Specific phosphorus compound)
The resin composition preferably contains a phosphorus compound containing a partial structure represented by the following structural formula (5) or (6) (hereinafter, referred to as “specific phosphorus compound”). The specific phosphorus compound, after completion of the polycondensation reaction, that is, for example, by adding during the kneading step or pelletizing step of the resin composition to deactivate the polymerization catalyst described later, polycondensation after that. It is possible to prevent the reaction from proceeding unnecessarily. As a result, it is possible to suppress the progress of polycondensation when the polycarbonate resin is heated in the molding step and the like, and thus suppress the elimination of the monohydroxy compound. Further, by deactivating the polymerization catalyst, coloring of the resin composition at high temperature can be suppressed.

Specific phosphorus compounds containing the partial structure represented by the structural formula (5) or (6) include phosphoric acid, phosphorous acid, phosphonic acid, hypophosphorous acid, polyphosphoric acid, phosphonic acid ester, and acidic phosphoric acid. Esters and the like can be adopted. Among the specific phosphorus compounds, phosphorous acid, phosphonic acid, and phosphonate ester are more excellent in the effect of deactivating the catalyst and suppressing the coloration, and phosphorous acid is particularly preferable.

As the phosphonic acid, for example, the following compounds can be adopted. Phosphonic acid (phosphorous acid), methylphosphonic acid, ethylphosphonic acid, vinylphosphonic acid, decylphosphonic acid, phenylphosphonic acid, benzylphosphonic acid, aminomethylphosphonic acid, methylenediphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid Acid, 4-methoxyphenylphosphonic acid, nitrilotris (methylenephosphonic acid), propylphosphonic acid anhydride and the like.

As the phosphonate ester, for example, the following compounds can be adopted. Dimethyl phosphonate, diethyl phosphonate, bis(2-ethylhexyl) phosphonate, dilauryl phosphonate, dioleyl phosphonate, diphenyl phosphonate, dibenzyl phosphonate, dimethyl methylphosphonate, diphenyl methylphosphonate, diethyl ethylphosphonate, diethyl benzylphosphonate Dimethyl phenylphosphonate, diethyl phenylphosphonate, dipropyl phenylphosphonate, diethyl (methoxymethyl)phosphonate, diethyl vinylphosphonate, diethyl hydroxymethylphosphonate, dimethyl (2-hydroxyethyl)phosphonate, p-methylbenzylphosphonate Diethyl, diethylphosphonoacetic acid, ethyl diethylphosphonoacetate, tert-butyl diethylphosphonoacetate, diethyl (4-chlorobenzyl)phosphonate, diethyl cyanophosphonate, diethyl cyanomethylphosphonate, 3,5-di-tert-butyl Diethyl-4-hydroxybenzylphosphonate, diethylphosphonoacetaldehyde diethyl acetal, diethyl (methylthiomethyl)phosphonate and the like.

As the acidic phosphoric acid ester, for example, the following compounds can be adopted. Dimethyl phosphate, diethyl phosphate, divinyl phosphate, dipropyl phosphate, dibutyl phosphate, bis(butoxyethyl) phosphate, bis(2-ethylhexyl) phosphate, diisotridecyl phosphate, dioleyl phosphate, distearyl phosphate, Phosphoric acid diesters such as diphenyl phosphate and dibenzyl phosphate, or mixtures of diesters and monoesters, diethyl chlorophosphate, stearyl zinc phosphate, etc.

The specific phosphorus compounds may be used alone or in combination of two or more.
The content of the specific phosphorus compound in the resin composition is preferably 0.1 mass ppm or more and 5 mass ppm or less as a phosphorus atom. If the content of the specific phosphorus compound is too small, the effect of deactivating the catalyst and suppressing coloration may be insufficient. On the other hand, if the content of the specific phosphorus compound is too large, the resin composition may be colored instead. Further, in this case, the resin composition is likely to be colored particularly in the durability test at high temperature and high humidity.

Further, by adjusting the content of the specific phosphorus compound according to the amount of the polymerization catalyst, it is possible to more reliably obtain the effects of catalyst deactivation and color suppression. The content of the specific phosphorus compound is preferably 0.5 times mol or more and 5 times mol or less, and 0.7 times mol or more and 4 times mol, as the amount of phosphorus atoms, relative to 1 mol of metal atoms of the polymerization catalyst. The amount is more preferably the following or less, and particularly preferably 0.8 times or more and 3 times or less the mol.

(Hindered phenol compound)
The resin composition of the present invention can be expected to have an effect of further suppressing coloration by adding a hindered phenol compound in combination with the specific phosphorus compound.
As the hindered phenol compound, for example, the following compounds can be adopted. 2,6-di-tert-butylphenol, 2,4-di-tert-butylphenol, 2-tert-butyl-4-methoxyphenol, 2-tert-butyl-4,6-dimethylphenol, 2,6-di- tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,5-di-tert-butylhydroquinone, n-octadecyl-3-(3',5'-di- tert-butyl-4′-hydroxyphenyl)propionate, 2-tert-butyl-6-(3′-tert-butyl-5′-methyl-2′-hydroxybenzyl)-4-methylphenyl acrylate, 2,2′ -Methylene-bis-(4-methyl-6-tert-butylphenol), 2,2'-methylene-bis-(6-cyclohexyl-4-methylphenol), 2,2'-ethylidene-bis-(2,4) -Di-tert-butylphenol), tetrakis-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]-methane, n-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, 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] and the like.
These may be used alone or in combination of two or more.

The content of the hindered phenolic compound is preferably 0.01 to 0.5 parts by mass, more preferably 0.05 to 0.3 parts by mass when the polycarbonate resin is 100 parts by mass. , 0.08 to 0.2 parts by mass is more preferable. The hindered phenol compound is preferably added to the polycarbonate resin in the kneading step, pelletizing step, or the like, similarly to the specific phosphorus compound.

(Antioxidant)
The resin composition of the present invention may contain a conventionally known antioxidant for the purpose of preventing oxidation.
As the antioxidant, for example, the following compounds can be adopted. Triphenylphosphite, tris(nonylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, tridecylphosphite, trioctylphosphite, trioctadecylphosphite, didecylmonophenylphosphite , Dioctylmonophenylphosphite, diisopropylmonophenylphosphite, monobutyldiphenylphosphite, monodecyldiphenylphosphite, monooctyldiphenylphosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octylphosphite Fight, tris(2,4-di-tert-butylphenyl) phosphite, 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), pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(3-laurylthiopropionate), glycerol-3-stearylthio Propionate, N,N-hexamethylene bis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 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}-2,4,8,10-tetraoxaspiro(5,5)undecane and the like.

These may be used alone or in combination of two or more. Further, the addition amount of the antioxidant is preferably 0.001 part by mass to 0.2 part by mass, more preferably 0.005 part by mass to 0.1 part by mass, when the polycarbonate resin is 100 parts by mass. More preferably 0.01 part by mass to 0.08 part by mass.
From the viewpoint of the effect of suppressing the coloring of the resin composition, it is preferable to use a phosphite-based antioxidant as the antioxidant. However, a compound containing a phosphorus atom, that is, the compound such as the specific phosphorus compound or the phosphite antioxidant is a resin in a durability test under high temperature and high humidity when the content is excessively high. It can be a coloring factor of the composition. Therefore, the total amount of phosphorus atom-containing compounds, including the specific phosphorus compound, is controlled so that the total amount of phosphorus atoms is preferably 40 mass ppm or less, more preferably 30 mass ppm or less with respect to the resin composition. Preferably.

The resin composition of the present invention may be mixed with a resin other than the above-mentioned polycarbonate resin, for example, aromatic polycarbonate resin, aromatic polyester, aliphatic polyester, polyamide, polystyrene, polyolefin, acrylic, amorphous polyolefin, ABS, A synthetic resin such as AS, a biodegradable resin such as polylactic acid or polybutylene succinate, a rubber or an elastomer can be used.
By mixing resins, impact resistance and molding processability can be easily improved, but transparency and heat resistance are often impaired, so care must be taken when selecting materials and compounding ratios. is there.

(Method for producing resin composition)
The resin composition of the present invention can be obtained by appropriately mixing the polycarbonate resin with the additives and the like as described above.
More specifically, for example, a polycarbonate resin obtained by a polycondensation reaction in a polymerization reaction tank is introduced into an extruder and kneaded while continuously supplying additives and the like to a by-product through a decompression facility. A method of devolatilizing and removing gas and low-molecular-weight volatile matter, extruding the melt-kneaded product in a strand form from the end of the extruder, cooling and solidifying and cutting it into pellets can be mentioned. The extruder is preferably a twin-screw extruder equipped with a pressure reducing device at the vent port in order to obtain sufficient devolatilization ability and uniform dispersion of the additive.

In order to improve the devolatilization efficiency in the extruder, by dropping a volatile liquid such as water into the system, it is possible to promote devolatilization together with volatile components in the molten resin. The number and position of the vent ports can be appropriately selected from the viewpoints of the length of the extruder and the devolatilization efficiency, and it is preferable to provide about 2 to 4 places.
It is preferable that the specific phosphorus compound be added as upstream of the extruder as possible so as to be promptly subjected to the catalyst deactivation reaction. After this, the catalyst is deactivated in the extruder, and by-developing and removing the by-product gas in the system at that time, the concentration of the volatile components in the resin composition extruded can be sufficiently reduced. it can.

If a phosphorus compound is locally added to the resin in a high concentration, it may rather cause resin deterioration.Therefore, a method of preparing a dilute solution with a soluble solvent such as water and dropping this into the system is recommended. preferable. The various additives and phosphorus compounds may be kneaded in advance in a carrier such as pellets or powder, or may be spread on the surface and then supplied into the extruder system. As a matter of course, as the carrier, it is preferable to use the target polycarbonate resin or other components constituting the resin composition.

As an operating condition of the extruder, in order to ensure the devolatilization efficiency, the pressure of the decompression equipment provided at the vent port is preferably 1.0 kPa or less, and particularly 0.3 kPa or less. The set temperature of the cylinder is preferably 210° C. or higher, particularly 220° C. or higher from the viewpoint of devolatilization efficiency and operation load. From the viewpoint of suppressing thermal decomposition, the temperature is preferably 270°C or lower, and particularly 265°C or lower.
In order to suppress heat generation from shearing, when selecting screw elements, it is possible to disperse and reduce the number of stagnant parts such as a kneading disk, to starve feed the kneaded material, and to set a low screw rotation speed. Do as appropriate.

[Crosslinked poly(meth)acrylic acid ester]
In the present invention, a crosslinked poly(meth)acrylic acid ester is used in order to impart unevenness to the surface of the film made of the resin composition so as to develop surface lubricity.
As the crosslinked poly(meth)acrylic acid ester of the present invention, an ester of the crosslinked poly(meth)acrylic acid of the present invention and an aliphatic alcohol containing no aromatic ring structure is preferable from the viewpoint of light resistance. Examples of the aliphatic alcohol that does not contain an aromatic ring structure include a chain or cyclic aliphatic alcohol, and a chain aliphatic alcohol is preferable. Further, the number of carbon atoms of the aliphatic alcohol that does not contain an aromatic ring structure is usually 1 to 10, preferably 1 to 8 and particularly preferably 1 to 6.

Specific examples of the crosslinked poly(meth)acrylate of the present invention include crosslinked poly(meth)acrylate, crosslinked poly(meth)acrylate, crosslinked poly(meth)acrylate, crosslinked poly(meth)acrylic. Butyl acid and the like can be mentioned. Among these, crosslinked poly(meth)acrylic acid methyl, crosslinked poly(meth)acrylic acid ethyl, and crosslinked poly(meth)acrylic acid propyl are preferable and crosslinked poly( Methyl (meth)acrylate and crosslinked poly(meth)acrylate are more preferable, and crosslinked poly(meth)acrylate is particularly preferable.

It is preferable that the crosslinked poly(meth)acrylic acid ester of the present invention has high heat resistance in view of a heating step of forming a composite with a resin or forming a film. As one means, heat resistance can be improved by increasing the crosslink density. As the lower limit of the heat resistance, even if it is melt-kneaded with the polycarbonate resin of the present invention, or the composite resin composition is melt-extruded, it is necessary to maintain its particle shape, so that 10% thermal decomposition in air is carried out. Using the temperature as an index, it is preferably 240° C. or higher, more preferably 260° C. or higher, particularly preferably 270° C. On the other hand, even if the crosslink density is increased to increase the heat resistance excessively, there is a practical upper limit.

The lower limit of the average particle diameter of the crosslinked poly(meth)acrylic acid ester used in the present invention is usually 1 μm or more. If the particle shape is excessively smaller than this, the resin composition may remarkably increase in viscosity, making it difficult to form a film, resulting in insufficient lubrication on the film surface, which is originally intended. On the other hand, the upper limit is preferably 5 μm or less, particularly preferably 3 μm or less. If the grain shape is excessively larger than this, the film is likely to tear when it is a very thin film, and the uneven shape may be relatively large for the thickness of the film, resulting in an undesirable appearance.

The lower limit of the refractive index of the crosslinked poly(meth)acrylic acid ester used in the present invention is preferably 1.49 or more, and particularly preferably 1.50 or more. The upper limit value is preferably 1.53 or less, particularly preferably 1.52 or less. Since the refractive index of the polycarbonate resin of the present invention is usually around 1.51, the refractive index of particles dispersed therein or attached to the surface thereof is preferably close to this value.

The method of dispersing the particles at least in the vicinity of the surface of the film of the present invention includes a method of mixing and dispersing in a base material when the film is formed as a single layer (method 1), and a method of forming a film having a multilayer structure. A method of mixing and dispersing it in the substrate for forming the surface layer (method 2), and a method of mixing and dispersing it in the substrate for forming the surface layer by coating or foil transfer after forming the film ( Method 3) etc. are mentioned.

In the method 1, in the resin composition manufacturing process described above, the additives may be supplied to an extruder and kneaded in the same manner as other additives, or particles alone or a particle dispersion masterbatch may be added in the film forming process. Good. The concentration of particles in the resin composition as the base material is usually 500 mass ppm or more and 20,000 mass ppm or less, preferably 1000 mass ppm or more and 10,000 mass ppm or less, and particularly 1500 in view of maintaining transparency and the effect of imparting lubricity. It is from mass ppm to 5000 mass ppm.

In Method 2, as in Method 1, it may be added to the surface layer base material in the resin composition manufacturing step or the film molding step, and as compared with Method 1, the amount of particles in the entire film can be reduced, and thus it is transparent. It is more preferable from the viewpoints of maintaining the properties and thin film processability.
In Method 3, it can be realized by dispersing it in a coating agent such as a hard coat, antireflection, antifogging imparting, and fingerprint adhesion prevention, which is generally processed on the film surface, and then coating this. Care should be taken because it may impair the performance for other purposes.
The film of the present invention thus obtained has excellent transparency and surface smoothness.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the following examples without departing from the scope of the invention.

(material)
<Dihydroxy compound>
・ISB: Isosorbide (Rocket Fleure)
-TCDDM: tricyclodecane dimethanol (Oxea)
<Carbonate diester>
・DPC: diphenyl carbonate (manufactured by Mitsubishi Chemical Corporation)
<Heat stabilizer>
-Irganox1010: pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (manufactured by BSF)-AS2112: tris(2,4-di-tert-butylphenyl) Phosphite (made by Adeka)
<Release agent>
E-275: ethylene glycol distearate (manufactured by NOF CORPORATION)
<Particles>
・Eposter MA1002: Crosslinked polymethylmethacrylate (manufactured by Nippon Shokubai Co., Ltd.)
Heat resistance 270 to 290° C., particle shape 2 to 3 μm, refractive index 1.51.
・Silton JC30: Synthetic zeolite (manufactured by Mizusawa Chemical Co.)
・Sylysia 740: Silica (manufactured by Fuji Silysia Chemical Ltd.)
・Satinton 5HB: Calcined Kaolin (manufactured by Takehara Chemical Co., Ltd.)

(Production of resin composition)
Polymerization of the polycarbonate resin was carried out using a continuous polymerization facility in which three vertical stirring reactors, one horizontal stirring reactor, and a twin-screw extruder equipped with a vacuum vent were connected in this order. ISB, TCDDM, and DPC were each melted in a raw material preparation tank, and were continuously supplied to the first vertical stirring reactor at a molar ratio of ISB/TCDDM/DPC=0.700/0.300/1.010. .. At the same time, an aqueous solution of calcium acetate monohydrate as a polymerization catalyst was supplied to the first vertical stirring reactor such that the amount of the catalyst was 1.5 μmol based on 1 mol of all hydroxy compounds.

The temperature, pressure, and residence time of each reactor are about 1st vertical type: 190° C., 25 kPa, 90 minutes, 2nd vertical type: 195° C., 10 kPa, 45 minutes, 3rd vertical type: 210° C., 3 kPa, 45 minutes, fourth horizontal type: 225° C., 0.5 kPa, 90 minutes.
The operation was performed while adjusting the internal pressure of the fourth horizontal stirring reactor such that the reduced viscosity of the obtained polycarbonate resin was approximately 0.38 to 0.39 dL/g.

The polymerization reaction product was withdrawn from the fourth horizontal stirring reactor at a flow rate of about 60 kg/hour and supplied in a molten state to a twin-screw extruder with a vacuum vent (TEX30α, L/D=42, manufactured by Japan Steel Works, Ltd.). ..
This extruder was equipped with decompression vent ports at three locations, and water was continuously poured at a ratio of about 2000 mass ppm to the molten resin before the second vent, so-called water injection devolatilization was performed. Next, in front of the third vent, Irganox 1010, AS2112, E-275 and the like such as a heat stabilizer were continuously supplied at a ratio of 0.1 parts by weight, 0.05 parts by weight and 0.3 parts by weight, and melt-kneaded.
The molten resin that passed through the extruder was filtered through a candle-type filter having an opening of 10 μm to remove foreign matters, discharged in a strand form from a die, water-cooled and solidified, and pelletized by a rotary cutter. Thus, a resin composition A containing a polycarbonate resin was obtained.

(Addition of particles to resin composition)
The resin composition A and various particles were melt-kneaded using a twin-screw extruder equipped with a vacuum vent. The particles were continuously supplied to the extruder set at 240° C. at a ratio of 5% by weight with respect to the resin composition A, and melt-kneaded while removing volatile components and the like under reduced pressure from the reduced pressure vent port, and the extruder tip. The particles were discharged in a strand form to obtain particle master batch pellets (MB1 to 4).

(Measurement)
(Reduced viscosity)
The molecular weight of the polycarbonate resin of the present invention can be evaluated by its reduced viscosity, and the higher the molecular weight, the larger the molecular weight.
A solution was prepared in which the resin concentration was precisely 0.6 g/dL using methylene chloride as a solvent, and the solution was measured with an Ubbelohde viscosity tube manufactured by Mori Yurika Kogyo Co., Ltd. in an environment of a temperature of 20±0.1° C. The relative viscosity ηrel was obtained from the following equation (i) from the solvent passage time t0 and the solution passage time t, and the specific viscosity ηsp was obtained from the relative viscosity ηrel from the following equation (ii).

ηrel=t/t0 (i)
ηsp=(η−η0)/η0=ηrel−1...(ii)
The reduced viscosity ηsp/c was obtained by dividing the obtained specific viscosity ηsp by the concentration c (g/dL).
If the reduced viscosity is too low, the mechanical strength of the film may be insufficient, and it is usually 0.30 dL/g or more, preferably 0.33 dL/g or more. On the other hand, if it is too high, the fluidity at the time of melting is lowered, and the moldability and productivity may be significantly impaired. Therefore, it is usually 1.2 dL/g or less, preferably 1.0 dL/g or less.

(Production of film)
Using a short-axis extruder equipped with a T die and a cooling roll, a film of the resin composition A alone, a film of the resin composition with particles added (dry-blended with the resin composition A alone, the concentration shown in Table 2) And those diluted with) were prepared by the melt extrusion molding method. The resin was supplied to the extruder and the T-die set at 240° C., and the film was continuously cast into a film by cooling casting on a cooling roll set at about 120° C. The roll temperature was finely adjusted to reduce gear marks and peeling marks. The take-up speed was adjusted so that the film thickness was about 60 μm using a contact type thickness gauge.

(Film surface friction)
The friction resistance between the films was measured according to ASTM D-1894 using a surface property measuring device "Shinto Kagaku Co., Ltd.: Tribogear HEIDON-14DR".
(Film haze)
The haze of the film was measured according to JIS K 7105 using a haze meter "NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd.".

(Film appearance)
If it has transparency in visual appearance and is fragile and supple during handling, ○, if transparency is remarkably left, particles are non-locally dispersed and surface irregularities are rough, or if they are brittle and easily cracked It was evaluated as x.

(Measurement of friction between film surfaces (1): Comparison of physical properties by particle type)
The friction resistance between the film surfaces was measured under the conditions of load: 100 g (surface pressure 1.1 kPa), sliding speed: 100 mm/min, and sliding area: 30×30 mm.
(Friction resistance between film surfaces (2): Comparison of physical properties by particle concentration)
The frictional resistance between the film surfaces was measured under the conditions of load: 200 g (surface pressure: 2.2 kPa), sliding speed: 100 mm/min, and sliding area: 30×30 mm.
(1) Comparison of physical properties by particle type A comparison of physical properties by particle type will be illustrated below.

From the above, regarding the reduced viscosity retention rate of MB1 to MB4 as compared with the reduced viscosity of the resin composition only, the crosslinked polymethylmethacrylate particles, synthetic zeolite, and silica have a reduced viscosity retention rate of 80% or more, and the decrease in viscosity is small. It was suitable. Calcined kaolin was not preferable because it caused a decrease in the molecular weight of the resin.

From the above, the crosslinked polymethylmethacrylate particles have a film haze of 5 or less, a dynamic friction coefficient with the film 1 of 0.250 or less, a good film appearance, and all evaluation items show suitable performance. It was The synthetic zeolite and silica did not have sufficient friction reduction. The film containing calcined kaolin had a poor resin appearance due to significant resin deterioration, and was not used for evaluation of friction resistance.

(2): Comparison of physical properties by particle concentration A comparison of physical properties by particle concentration will be illustrated below.

From the above, in the system in which the particles of crosslinked polymethylmethacrylate were added, sufficient lubricity could be imparted.

Claims (4)

A film made of a resin composition containing a polycarbonate resin,
The polycarbonate resin comprises a structural unit (a) derived from a dihydroxy compound represented by the following general formula (1), an aliphatic hydrocarbon dihydroxy compound, an alicyclic hydrocarbon dihydroxy compound, and an ether-containing dihydroxy compound. A copolymer containing a structural unit (b) derived from one or more selected dihydroxy compounds, wherein the compositional ratio of the structural unit (a) is 40 mol% or more and 90 mol% or less,
The resin composition contains crosslinked poly(meth)acrylic acid ester particles having a refractive index of 1.50 or more and 1.53 or less,
The concentration of the crosslinked poly(meth)acrylic acid ester particles in the resin composition is 500 mass ppm or more and 20000 mass ppm or less,
By the method based on ASTM D-1894, including the polycarbonate resin under the conditions of load: 100 g (surface pressure 1.1 kPa), sliding speed: 100 mm/min, sliding area: 30×30 mm, and the cross-linking. A film having a dynamic friction coefficient of 0.250 or less, which is obtained by measuring a friction resistance with a film containing no poly(meth)acrylic acid ester particles .

The film according to claim 1, wherein the crosslinked poly(meth)acrylic acid ester particles have an average particle diameter of 1 μm or more and 5 μm or less. The film according to claim 1 or 2, wherein the particles are crosslinked polymethylmethacrylate particles. The film according to any one of claims 1 to 3, wherein the polycarbonate resin is a polycarbonate resin using a Group 2 metal compound as a transesterification reaction catalyst.