JP6211830B2 - Polycarbonate resin - Google Patents

Description

  The present invention relates to a polycarbonate resin excellent in heat resistance, weather resistance, surface hardness, low water absorption, and impact resistance.

  In recent years, transparent resins having excellent performance have been required in various fields including optical parts and automobile parts. Conventionally, polycarbonate resins (hereinafter referred to as PCs), methacrylic resins, etc. are known as transparent resins, and in a wide range of fields such as electrical and electronic parts, optical parts, automobile parts, mechanical parts in the form of molded products and films. It is used. PC has a high elongation at break and excellent impact resistance, but has a problem that the surface is very soft (pencil hardness 4B to 2B) and easily damaged. Therefore, a method has been proposed in which an acrylic ester is applied to the polycarbonate substrate surface and a protective film is formed by ultraviolet curing (Patent Document 1). However, there is a problem that cracks due to shrinkage during curing and the process becomes complicated. Moreover, since an aromatic ring is included in the main chain, a step for imparting weather resistance is also required.

On the other hand, methacrylic acid resins such as polymethyl methacrylate have high transparency and hard surface hardness (pencil hardness H to 3H), and are often used as optical materials such as lenses and optical fibers. However, since the glass transition temperature is as low as about 100 ° C. and the heat resistance is inferior, the use in the field having heat resistance is limited. Furthermore, there is a problem that the impact resistance is low.
Recently, it has been proposed that isosorbide, a plant-derived monomer, is used to obtain a polycarbonate having excellent weather resistance and surface hardness by transesterification with diphenyl carbonate (Patent Document 2). However, due to the high water absorption derived from the isosorbide skeleton, the dimensional change is large in an environment of high temperature and high humidity, and there are cases where the use is limited to the use of precision parts.

  Conventionally, a copolymer composition of 2,2,4,4-tetramethylcyclobutanediol (hereinafter referred to as TMCB) and an aliphatic diol or bisphenol has been reported (Patent Documents 3 and 4). Polycarbonate containing TMCB is excellent in heat resistance, surface hardness, and low water absorption, but has difficulty in weather resistance when it contains bisphenol. Although copolymerization with aliphatic diols is excellent in weather resistance, there is a problem in impact resistance. So far, resins and molded products that have been combined with heat resistance, weather resistance, surface hardness, low water absorption, and impact resistance have been provided. It wasn't.

Japanese Patent Publication No.4-2614 International Publication No. 2004/111106 Pamphlet JP-A-2-222416 Japanese Patent Publication No. 38-26798

  An object of the present invention is to provide a polycarbonate resin excellent in heat resistance, weather resistance, surface hardness, low water absorption, and impact resistance.

As a result of intensive research, the inventors of the present invention constituted a unit (A) (the following formula (A)) and a unit (B) (the following formula (B)) at a specific ratio, thereby providing heat resistance and weather resistance. The inventors have found that a polycarbonate resin and a molded article excellent in properties, surface hardness, low water absorption, and impact resistance can be obtained, and have completed the present invention.
That is, according to the present invention, the objects of the invention are achieved by the following.

で表される単位（Ａ）と下記式（Ｂ）

（式中、Ｘは、炭素数３〜２０のアルキレン基を有し、Ｒは水素原子または炭素数１〜２０のアルキル基またはシクロアルキル基を表し、ｍは１〜１０の整数を示す。）
で表される単位（Ｂ）を含み、単位（Ａ）と単位（Ｂ）とのモル比（Ａ／Ｂ）が８０／２０〜９９／１であり、２０℃の塩化メチレン溶液で測定された比粘度が０．２０〜１．５０であるポリカーボネート樹脂。 1. The main repeating unit is the following formula (A)

Unit (A) and the following formula (B)

(In formula, X has a C3-C20 alkylene group, R represents a hydrogen atom, a C1-C20 alkyl group, or a cycloalkyl group, and m shows the integer of 1-10.)
Wherein the unit (B) represented in the molar ratio of the unit (A) and the unit (B) (A / B) is 80 / 20-99 / 1 der is, measured in methylene chloride solution of 20 ° C. and specific viscosity 0.20 to 1.50 der Ru polycarbonate resin.

2. 2. The polycarbonate resin according to item 1, wherein the molar ratio (A / B) of the unit (A) to the unit (B) is 85/15 to 98/2.
3. The polycarbonate resin according to item 1, wherein R in the formula (B) is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and X has 3 to 12 carbon atoms.
4. The polycarbonate resin according to item 1, wherein the specific viscosity measured with a 20 ° C. methylene chloride solution is 0.25 to 1.20 .
5. 2. The polycarbonate resin as described in 1 above, wherein the saturated water absorption is 1.0% or less.
6). 2. The polycarbonate resin according to item 1, wherein the pencil hardness is F to 4H.
7). 2. The polycarbonate resin according to item 1, wherein the glass transition temperature is 70 ° C. to 130 ° C.
8). 8. A molded article made of the polycarbonate resin according to any one of 1 to 7 above.
9. A film made of the polycarbonate resin according to any one of the preceding items 1 to 7.

  The polycarbonate resin of the present invention contains a carbonate structural unit derived from a diol having a cyclobutane skeleton and a specific aliphatic diol, so that it has excellent heat resistance, high surface hardness, and can greatly reduce water absorption. It became possible to have characteristics. Therefore, the industrial effect that it produces is exceptional.

Hereinafter, the present invention will be described in detail.
<Polycarbonate resin>
In the polycarbonate resin of the present invention, the main repeating unit is composed of a unit (A) and a unit (B).

(Unit (A))
The unit (A) in the present invention is derived from 2,2,4,4-tetramethyl-1,3-cyclobutanediol as shown in the formula (A). A polymer derived from 2,2,4,4-tetramethyl-1,3-cyclobutanediol is a material having high heat resistance and high pencil hardness.

で表される（Ａ−１）および（Ａ−２）から誘導されるカーボネート構成単位が例示される。これらは、それぞれｔｒａｎｓ−２，２，４，４−テトラメチル−１，３−シクロブタンジオール、ｃｉｓ−２，２，４，４−テトラメチル−１，３−シクロブタンジオールと呼ばれ、通常、異性体混合物として得られる。本発明における２，２，４，４−テトラメチル−１，３−シクロブタンジオールのｃｉｓ−ｔｒａｎｓ混合比率は、効果を損なわない範囲で選択し使用することができる。 The above formula (A) is a stereoisomer related formula

Carbonate structural units derived from (A-1) and (A-2) represented by These are called trans-2,2,4,4-tetramethyl-1,3-cyclobutanediol and cis-2,2,4,4-tetramethyl-1,3-cyclobutanediol, respectively. Obtained as a body mixture. The cis-trans mixing ratio of 2,2,4,4-tetramethyl-1,3-cyclobutanediol in the present invention can be selected and used as long as the effect is not impaired.

(Unit (B))
The unit (B) in the present invention is a unit derived from a linear aliphatic diol or an aliphatic diol having a side chain alkyl group or a side chain cycloalkyl group, as shown in the formula (B).
The unit (B) preferably has a total carbon number in the range of 4 to 15, more preferably in the range of 5 to 12. Within such a range, the HDT (deflection temperature under load) of the polycarbonate resin is kept high.

(X in unit (B))
In the formula (B), X represents an alkylene group having 3 to 20 carbon atoms.
X is preferably an alkylene group having 3 to 18 carbon atoms, more preferably an alkylene group having 3 to 15 carbon atoms, still more preferably an alkylene group having 3 to 12 carbon atoms, and particularly preferably an alkylene group having 4 to 12 carbon atoms. is there. Examples of the alkylene group include a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, an undecylene group, and a dodecylene group.

(R in unit (B))
In the formula (B), R represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or a cycloalkyl group. R is preferably a hydrogen atom or an alkyl group.
As an alkyl group, Preferably it is a C1-C12 alkyl group, More preferably, it is a C1-C8 alkyl group. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
As a cycloalkyl group, Preferably it is a C3-C12 cycloalkyl group, More preferably, it is a C3-C8 cycloalkyl group. Specific examples include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group.

(M in unit (B))
In the formula (B), m represents an integer of 1 to 10, preferably an integer of 2 to 8, more preferably an integer of 2 to 5.

(Aliphatic diol from which the unit (B) is derived)
The unit (B) is derived from a linear aliphatic diol or an aliphatic diol having a side chain alkyl group or a side chain cycloalkyl group. Examples of the aliphatic diol include 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1.9-nonanediol, , 10-decanediol, 1,12-dodecanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-n-butyl-2-ethyl-1 , 3-propanediol, 2,2-diethyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, 1,2-hexane glycol, 1,2-octyl glycol, 2-ethyl- 1,3-hexanediol, 2,3-diisobutyl-1,3-propanediol, 2,2-diisoamyl-1,3-propanediol 2-methyl-2-propyl-1,3-propanediol are preferred. These aliphatic diols can be used alone or in combination of two or more.

(composition)
As for the polycarbonate resin of this invention, the main repeating unit contains a unit (A) and a unit (B), and those molar ratio (A / B) is 80 / 20-99 / 1. A molar ratio (A / B) of 80/20 to 99/1 is preferable because the pencil hardness is high and the heat resistance is also high. The molar ratio (A / B) between the unit (A) and the unit (B) is more preferably 85/15 to 98/2, still more preferably 90/10 to 97/3, and particularly preferably 92. / 8 to 96/4. Within this composition range, the pencil hardness is more preferably 2H or more. The molar ratio (A / B) is measured and calculated by proton NMR of JNM-AL400 manufactured by JEOL.

The main repeating unit in the present invention is such that the total of the unit (A) and the unit (B) is 60 mol% or more, preferably 70 mol% or more, more preferably 80 mol%, based on all repeating units. It is preferable for it to be in the above-mentioned range because of excellent balance of heat resistance, weather resistance, low water absorption, surface hardness and impact characteristics.
Examples of the compound that derives another repeating unit include alicyclic diol compounds, aromatic dihydroxy compounds, and oxyalkylene glycols such as diethylene glycol, triethylene glycol, tetraethylene glycol, and polyethylene glycol.

  Examples of the alicyclic diol compound include cyclohexanedimethanol, tricyclodecanedimethanol, adamantanediol, pentacyclopentadecanedimethanol, 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4, Examples include 8,10-tetraoxaspiro [5.5] undecane and isosorbide.

  Examples of the aromatic dihydroxy compound include α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene (bisphenol M), 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 1,1. -Bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide, bisphenol A, 2,2-bis (4-hydroxy-3-methylphenyl) propane (bisphenol C), 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane (bisphenol) AF) and 1,1-bis (4-hydroxyphenyl) decane.

(Production method of polycarbonate resin)
The polycarbonate resin of the present invention is produced by a reaction means known per se for producing an ordinary polycarbonate resin, for example, a method of reacting a diol component with a carbonate precursor such as a carbonic acid diester. Next, basic means for these manufacturing methods will be briefly described.

  The transesterification reaction using a carbonic acid diester as a carbonate precursor is performed by a method in which an aromatic dihydroxy component in a predetermined ratio is stirred with a carbonic acid diester while heating with an inert gas atmosphere to distill the generated alcohol or phenols. . The reaction temperature varies depending on the boiling point of the alcohol or phenol produced, but is usually in the range of 120 to 350 ° C. The reaction is completed while distilling off the alcohol or phenol produced under reduced pressure from the beginning. Moreover, you may add a terminal stopper, antioxidant, etc. as needed.

  Examples of the carbonic acid diester used in the transesterification include esters such as an aryl group having 6 to 12 carbon atoms and an aralkyl group which may be substituted. Specific examples include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate and m-cresyl carbonate. Of these, diphenyl carbonate is particularly preferred. The amount of diphenyl carbonate used is preferably 0.97 to 1.10 mol, more preferably 1.00 to 1.06 mol, per 1 mol of the total of dihydroxy compounds.

In the melt polymerization method, a polymerization catalyst can be used to increase the polymerization rate. Examples of the polymerization catalyst include alkali metal compounds, alkaline earth metal compounds, nitrogen-containing compounds, and metal compounds.
As such compounds, organic acid salts, inorganic salts, oxides, hydroxides, hydrides, alkoxides, quaternary ammonium hydroxides, and the like of alkali metals and alkaline earth metals are preferably used. It can be used alone or in combination.

  Examples of the alkali metal compound include sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, sodium bicarbonate, sodium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, sodium acetate, potassium acetate, cesium acetate, lithium acetate, Sodium stearate, potassium stearate, cesium stearate, lithium stearate, sodium borohydride, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, phosphorus Examples include dilithium oxyhydrogen, disodium phenylphosphate, disodium salt of bisphenol A, 2 potassium salt, 2 cesium salt, 2 lithium salt, sodium salt of phenol, potassium salt, cesium salt, lithium salt and the like.

  Alkaline earth metal compounds include magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, magnesium diacetate, calcium diacetate, strontium diacetate, diacetate Barium and the like are exemplified.

  Examples of nitrogen-containing compounds include quaternary ammonium hydroxides having alkyl, aryl groups, etc., such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and trimethylbenzylammonium hydroxide. Can be mentioned. Further, tertiary amines such as triethylamine, dimethylbenzylamine, and triphenylamine, and imidazoles such as 2-methylimidazole, 2-phenylimidazole, and benzimidazole can be used. Moreover, bases or basic salts such as ammonia, tetramethylammonium borohydride, tetrabutylammonium borohydride, tetrabutylammonium tetraphenylborate, tetraphenylammonium tetraphenylborate and the like are exemplified.

Examples of metal compounds include zinc aluminum compounds, germanium compounds, organotin compounds, antimony compounds, manganese compounds, titanium compounds, zirconium compounds, and the like. These compounds may be used alone or in combination of two or more.
The amount of these polymerization catalysts used is preferably 1 × 10 ⁻⁹ to 1 × 10 ⁻² equivalent, preferably 1 × 10 ⁻⁸ to 1 × 10 ⁻⁵ equivalent, more preferably 1 × with ^respect to 1 mol of the diol component. It is selected in the range of 10 ⁻⁷ to 1 × 10 ⁻³ equivalents.

  In addition, a catalyst deactivator can be added at a later stage of the reaction. As the catalyst deactivator to be used, a known catalyst deactivator is effectively used. Among them, sulfonic acid ammonium salt and phosphonium salt are preferable. Furthermore, salts of dodecylbenzenesulfonic acid such as tetrabutylphosphonium salt of dodecylbenzenesulfonic acid and salts of paratoluenesulfonic acid such as tetrabutylammonium salt of paratoluenesulfonic acid are preferable.

  Further, as esters of sulfonic acid, methyl benzenesulfonate, ethyl benzenesulfonate, butyl benzenesulfonate, octyl benzenesulfonate, phenyl benzenesulfonate, methyl paratoluenesulfonate, ethyl paratoluenesulfonate, butyl paratoluenesulfonate, Octyl paratoluenesulfonate, phenyl paratoluenesulfonate and the like are preferably used. Among these, dodecylbenzenesulfonic acid tetrabutylphosphonium salt is most preferably used.

  The amount of the catalyst deactivator used is preferably 0.5 to 50 mol per mol of the catalyst when at least one polymerization catalyst selected from alkali metal compounds and / or alkaline earth metal compounds is used. It can be used in a proportion, more preferably in a proportion of 0.5 to 10 mol, still more preferably in a proportion of 0.8 to 5 mol.

(Specific viscosity: η _SP )
The specific viscosity (η _SP ) of the polycarbonate resin of the present invention is preferably 0.20 to 1.50. When the specific viscosity is 0.20 to 1.50, the strength and moldability are good. The specific viscosity (η _SP ) is more preferably 0.25 to 1.20, and still more preferably 0.30 to 0.60.
If the specific viscosity of the polycarbonate resin of the present invention is smaller than 0.2, the strength of the injection-molded molded piece tends to be lowered, and if it is larger than 1.50, the molding processability at the time of injection molding tends to be lowered.
The specific viscosity referred to in the present invention is determined from an solution obtained by dissolving 0.7 g of polycarbonate resin in 100 ml of methylene chloride at 20 ° C. using an Ostwald viscometer.
Specific viscosity (η _SP ) = (t−t ₀ ) / t ₀
[T ₀ is methylene chloride falling seconds, t is sample solution falling seconds]

  In addition, as a specific measurement of specific viscosity, it can carry out in the following way, for example. First, the polycarbonate resin is dissolved in 20 to 30 times the weight of methylene chloride, and the soluble component is collected by celite filtration, and then the solution is removed and dried sufficiently to obtain a solid component soluble in methylene chloride. Using a Ostwald viscometer, the specific viscosity at 20 ° C. is determined from a solution of 0.7 g of the solid dissolved in 100 ml of methylene chloride.

(Glass transition temperature: Tg)
The glass transition temperature (Tg) of the polycarbonate resin of the present invention is preferably 70 to 130 ° C, more preferably 80 to 120 ° C, and further preferably 90 to 110 ° C. When the Tg is 70 ° C. to 130 ° C., the heat resistant stability and moldability are favorable when used as an optical molded article.
When the glass transition temperature (Tg) of the polycarbonate resin of the present invention is lower than 70 ° C., the heat resistance of the molded piece becomes insufficient, and when it is higher than 130 ° C., the moldability during injection molding tends to deteriorate. .
The glass transition temperature (Tg) is measured at 29 ° C./min using a 2910 type DSC manufactured by TA Instruments Japan.

(Saturated water absorption)
The saturated water absorption of the polycarbonate resin of the present invention is preferably 1.0% or less, more preferably 0.8% or less. A water absorption of 1.0% or less is preferred because it can reduce dimensional changes and warpage due to water absorption in the molded product. If the water absorption is higher than 1.0%, the dimensional change and warpage due to water absorption in the molded product and various physical property deteriorations tend to be remarkable.

(Pencil hardness)
The polycarbonate resin of the present invention preferably has a pencil hardness of F to 4H. In terms of excellent scratch resistance, it is preferably H or more, and more preferably 2H or more. The pencil hardness can be increased by increasing the composition of the unit (A) based on all repeating units. In the present invention, the pencil hardness is a hardness that does not leave a scratch mark even when the resin of the present invention is rubbed with a pencil having a specific pencil hardness, and measured according to JIS K-5600. It is preferable to use as an index the pencil hardness used in the surface hardness test of the coating film that can be formed. Pencil hardness becomes soft in the order of 9H, 8H, 7H, 6H, 5H, 4H, 3H, 2H, H, F, HB, B, 2B, 3B, 4B, 5B, 6B, the hardest is 9H, The soft one is 6B.

(impurities)
The amount of the monohydroxy compound contained in the polycarbonate resin is preferably 700 ppm or less, more preferably 500 ppm or less, and particularly preferably 200 ppm or less in the reaction solution at the outlet of the final polymerization reactor. The concentration of the carbonic acid diester in the polycarbonate resin of the present invention is preferably 200 ppm or less, more preferably 100 ppm or less, particularly preferably 60 ppm or less, and particularly preferably 30 ppm or less. These impurities can be reduced by controlling the degree of vacuum of the polymerization reaction.

(Additive)
In addition, the polycarbonate resin of the present invention can be used as a heat stabilizer, a plasticizer, a light stabilizer, a polymerized metal inactivator, a flame retardant, a lubricant, an antistatic agent, a surfactant, an antibacterial agent, an ultraviolet Additives such as an absorbent, a release agent, and an impact modifier can be blended.
The polycarbonate resin of the present invention may be used in combination with other resins as long as the effects of the present invention are not impaired.

(Surface impact)
The polycarbonate resin used in the present invention is excellent in impact property because the fracture mode of surface impact is ductile fracture. The surface impact property was measured using a 2 mm thick square plate at a test temperature of 23 ° C., a test speed of 7 m / sec, a striker diameter of 1/2 inch, and a receiving diameter of 1 inch using a high-speed impact tester. The probability of brittle fracture is preferably 50% or less. More preferably, it is 30% or less, more preferably 20% or less, particularly preferably 15% or less, and most preferably 10% or less.
The maximum impact energy is preferably 20 J or more. More preferably, it is 25J or more, More preferably, it is 30J or more, Most preferably, it is 35J or more. The upper limit is not particularly limited, but 100 J or less is sufficient. When the probability of the surface impact fracture mode being brittle fracture exceeds 50%, or when the maximum impact energy is less than 20 J, it is difficult to use in applications where impact properties are required.

<Molded body>
A molded body formed using the polycarbonate resin of the present invention is molded by an arbitrary method such as an injection molding method, a compression molding method, an extrusion molding method, or a solution casting method. Since the polycarbonate resin of the present invention is excellent in moldability and heat resistance, it can be used as various molded products. In particular, optical lenses, optical discs, liquid crystal panels, optical cards, sheets, films, optical fibers, connectors, vapor-deposited plastic reflectors, structural materials for optical components such as displays, electrical and electronic parts such as exteriors and front panels of personal computers and mobile phones. It can be advantageously used as a molded article suitable for automotive applications such as automotive headlamps and windows, or functional material applications.

<Film>
Specifically, the film formed using the polycarbonate resin of the present invention is a surface protective film, a decorative film, a front plate, a retardation film, a plastic substrate film, a polarizing plate protective film, an antireflection film, and a brightness increase. Uses such as a film, a protective film for an optical disk, and a diffusion film can be mentioned.
Examples of the method for producing the film include known methods such as a solution casting method, a melt extrusion method, a hot press method, and a calendar method. Of these, the solution casting method and the melt extrusion method are preferable, and the melt extrusion method is particularly preferable from the viewpoint of productivity.

  In the melt extrusion method, a method in which a resin is extruded using a T die and sent to a cooling roll is preferably used. The temperature at this time is determined from the molecular weight, Tg, melt flow characteristics and the like of the polycarbonate resin, but is in the range of 180 to 350 ° C, more preferably in the range of 200 to 320 ° C. When the temperature is lower than 180 ° C., the viscosity becomes high, and the orientation and stress strain of the polymer tend to remain. On the other hand, when the temperature is higher than 350 ° C., problems such as thermal deterioration, coloring, and die line (stripe) from the T-die are likely to occur.

  Further, since the polycarbonate resin of the present invention has good solubility in an organic solvent, a solution casting method can also be applied. In the case of the solution casting method, methylene chloride, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, dioxolane, dioxane and the like are preferably used as the solvent. The amount of residual solvent in the film obtained by the solution casting method is preferably 2% by weight or less, more preferably 1% by weight or less. When the residual solvent amount exceeds 2% by weight, the glass transition temperature of the film is remarkably lowered, which is not preferable from the viewpoint of heat resistance.

  The thickness of the unstretched film using the polycarbonate of the present invention is preferably in the range of 30 to 400 μm, more preferably in the range of 40 to 300 μm. When the unstretched film-like product is further stretched to obtain a retardation film, it may be appropriately determined within the above range in consideration of a desired retardation value and thickness of the optical film.

  Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited thereto. In the examples, “parts” means “parts by weight”. The resins used and the evaluation methods used in the examples are as follows.

1. Polymer composition ratio (NMR)
Each repeating unit was measured by proton NMR of JNM-AL400 manufactured by JEOL Ltd., and the polymer composition ratio (molar ratio) was calculated.

2. Specific Viscosity Measurement The viscosity was determined using an Ostwald viscometer from a solution of 0.7 g of polycarbonate resin in 100 ml of methylene chloride at 20 ° C.
Specific viscosity (η _SP ) = (t−t ₀ ) / t ₀
[T ₀ is methylene chloride falling seconds, t is sample solution falling seconds]

3. Measurement of glass transition temperature (Tg) Using a thermal analysis system DSC-2910 manufactured by TA Instruments Co., Ltd. using 8 mg of polycarbonate resin, in a nitrogen atmosphere (nitrogen flow rate: 40 ml) according to JIS K7121 / Min), temperature increase rate: measured at 20 ° C./min.

4). Water absorption rate The water absorption rate was measured by measuring the increase in weight after immersion in water at 25 ° C. for 48 hours using a cast film having a thickness of 200 μm obtained by evaporating the methylene chloride after dissolving the polycarbonate resin pellets in methylene chloride. The water absorption was determined by the following formula.
Water absorption rate (%) = {(film weight after water absorption−film weight before water absorption) / film weight before water absorption} × 100

5. Pencil hardness After drying polycarbonate resin pellets at 100 ° C. for 24 hours, using a 75 ton molding machine (JSW J-75EIII) manufactured by JSW Co., Ltd., a 2 mm thick square plate was molded, and the molded specimen was used. Then, it was measured by the pencil hardness test method of JIS K5600.

6). Weathering discoloration In accordance with JIS B7753, a sunshine weatherometer S80 manufactured by Suga Test Instruments Co., Ltd. was used to set a discharge voltage of 50 V and a discharge current of 60 A with a sunshine carbon arc (4 pairs of ultralong life carbon), irradiation and surface spraying. Irradiation treatment was performed for 500 hours on a flat surface (width 60 mm x length 60 mm x thickness 3 mm) of an injection-molded piece under the conditions of (rainfall) at a black panel temperature of 63 ° C and a relative humidity of 50%. It was. The surface spray (rainfall) time was 12 minutes / 1 hour. A type glass filter was used. For the test pieces before and after the test, a color difference ΔE was measured using a spectroscopic color difference meter SE-2000 manufactured by Nippon Denshoku Industries Co., Ltd. The smaller ΔE, the smaller the discoloration.

7). Surface impact Thickness 2mm thick square plate using a high-speed impact tester Shimadzu HYDROSHOTHITS-P10 (Shimadzu Corporation) at a test temperature of 23 ° C, a test speed of 7 m / sec, a striker diameter of 1/2 inch and a receiving diameter of 1 inch The test was conducted 10 times, and the probability of the brittle fracture at that time was evaluated.

[Example 1]
<Manufacture of polycarbonate resin>
2,464,4-tetramethyl-1,3-cyclobutanediol (hereinafter abbreviated as TMCB) 464 parts, 1,6-hexanediol (hereinafter abbreviated as HD) 33 parts, diphenyl carbonate (hereinafter abbreviated as DPC) 750 Parts and 2.3 × 10 ⁻¹ parts of lithium acetate as a catalyst were heated to 180 ° C. in a nitrogen atmosphere and melted. Thereafter, the degree of vacuum was adjusted to 13.4 kPa over 30 minutes. Thereafter, the temperature was raised to 250 ° C. at a rate of 60 ° C./hr, held at that temperature for 10 minutes, and then the degree of vacuum was set to 133 Pa or less over 1 hour. The reaction was carried out with stirring for a total of 6 hours. After completion of the reaction, the mixture was discharged from the bottom of the reaction tank under nitrogen pressure and cut with a pelletizer while cooling in a water tank to obtain a pellet. Various evaluations were performed on the pellets, and the evaluation results are shown in Table 1.

[Example 2]
<Manufacture of polycarbonate resin>
The same evaluation as in Example 1 was performed except that 479 parts of TMCB, 28 parts of 1,9-nonanediol (hereinafter abbreviated as ND), and 750 parts of DPC were used as raw materials. The results are shown in Table 1.

[Example 3]
<Manufacture of polycarbonate resin>
The same evaluation as in Example 1 was performed except that 485 parts of TMCB, 28 parts of 1,12-dodecanediol (hereinafter abbreviated as DDD), and 750 parts of DPC were used as raw materials. The results are shown in Table 1.

[Example 4]
<Manufacture of polycarbonate resin>
The same evaluation as in Example 1 was performed except that 479 parts of TMCB, 27 parts of 2,4-diethylpentanediol (hereinafter referred to as DEP), and 750 parts of DPC were used as raw materials. The results are shown in Table 1.

[Example 5]
<Manufacture of polycarbonate resin>
The same evaluation as in Example 1 was performed except that 404 parts of TMCB, 83 parts of HD, and 750 parts of DPC were used as raw materials. The results are shown in Table 1.

[Example 6]
<Manufacture of polycarbonate resin>
TMCB 353 parts, 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane (hereinafter abbreviated as SPG) 106 parts, HD 41 parts, Except using 750 parts of DPC as a raw material, the same operation as Example 1 was performed and the same evaluation was performed. The results are shown in Table 1.

[Comparative Example 1]
<Manufacture of polycarbonate resin>
Except that 505 parts of TMCB and 214 parts of DPC were used as raw materials, the same operation as in Example 1 was performed, and the same evaluation was performed. The results are shown in Table 1.

[Comparative Example 2]
<Manufacture of polycarbonate resin>
Except that TMCB 379 parts, HD 103 parts, and DPC 750 parts were used as raw materials, the same operation as in Example 1 was performed, and the same evaluation was performed. The results are shown in Table 1.

[Comparative Example 3]
<Manufacture of polycarbonate resin>
The same evaluation as in Example 2 was performed except that a polycarbonate resin having a specific viscosity of 0.198 was used. The results are shown in Table 1.

[Comparative Example 4]
<Manufacture of polycarbonate resin>
The same operation as in Example 1 was carried out except that 379 parts of TMCB, 254 parts of 1,1-bis (4-hydroxyphenyl) -1-phenylethane (hereinafter abbreviated as BP-AP) and 750 parts of DPC were used as raw materials. The same evaluation was performed. The results are shown in Table 1.

[Comparative Example 5]
<Manufacture of polycarbonate resin>
Except that ISS 511 parts and DPC 750 parts were used as raw materials, the same operation as in Example 1 was performed, and the same evaluation was performed. The results are shown in Table 1.

[Comparative Example 6]
<Manufacture of polycarbonate resin>
Except for using ISS 435 parts, HD 60 parts, and DPC 750 parts as raw materials, the same operations as in Example 1 were performed and the same evaluations were performed. The results are shown in Table 1.

[Comparative Example 7]
Various evaluation results are shown in Table 1 using bisphenol A type polycarbonate resin (Panlite L1225 manufactured by Teijin Chemicals Ltd.).

[Comparative Example 8]
Various evaluation results are shown in Table 1 using polyacrylic resin (Acrypet MF manufactured by Mitsubishi Rayon).

  The polycarbonate resin of the present invention is useful as a structural material or an optical film for optical components.

Claims (9)

The main repeating unit is the following formula (A)

Unit (A) and the following formula (B)

(In formula, X has a C3-C20 alkylene group, R represents a hydrogen atom, a C1-C20 alkyl group, or a cycloalkyl group, and m shows the integer of 1-10.)
Wherein the unit (B) represented in the molar ratio of the unit (A) and the unit (B) (A / B) is 80 / 20-99 / 1 der is, measured in methylene chloride solution of 20 ° C. and specific viscosity 0.20 to 1.50 der Ru polycarbonate resin.   The polycarbonate resin according to claim 1, wherein the molar ratio (A / B) of the unit (A) to the unit (B) is 85/15 to 98/2.   2. The polycarbonate resin according to claim 1, wherein in the unit (B), R in the formula (B) is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and X has 3 to 12 carbon atoms. The polycarbonate resin according to claim 1, which has a specific viscosity measured in a methylene chloride solution at 20 ° C of 0.25 to 1.20 .   The polycarbonate resin according to claim 1, which has a saturated water absorption of 1.0% or less.   The polycarbonate resin according to claim 1, which has a pencil hardness of F to 4H.   The polycarbonate resin according to claim 1, which has a glass transition temperature of 70C to 130C.   A molded article made of the polycarbonate resin according to any one of claims 1 to 7.   The film which uses the polycarbonate resin as described in any one of Claims 1-7 as a raw material.