Polycarbonate resin composition film and decorative film

Abstract

To provide a polycarbonate resin composition film and a decorative film which have small thickness unevenness, are excellent in a surface property and in printing characteristics.SOLUTION: A film contains (A) a polycarbonate resin component (component a) and (B) a thermoplastic elastomer component (component b). The film is formed from a polycarbonate resin composition containing 70 to 98 wt.% of the component a and 30 to 2 wt.% of the component b in 100 wt.% of a total of the component a and the component b. The film has thickness of 0.1 mm to 0.5 mm. Therein: an absolute value of a thickness tolerance ΔTDn between neighboring measurement points of the film measured by a method described in the present disclosure, satisfies 15 μm or less; and an absolute value of a tolerance ΔTDa between thickness arithmetic average values of the respective measurement points of the film measured by the method described in the present disclosure satisfies 10 μm or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a polycarbonate resin composition film and a decorative film that have excellent surface characteristics with little thickness unevenness and excellent printability.

Background Art

[0002] Polycarbonate resin is widely used in various fields by taking advantage of its features such as low cost, light weight, transparency, moldability, optical properties, heat resistance, processability, and excellent mechanical strength, and is also used as a polycarbonate resin film. The film is widely used in printing, thermoforming, vacuum forming, insert molding, metal vapor deposition, sputtering, etc. In recent years, with the progress of processing technologies such as printing and thermoforming, the processing conditions have become severe due to high production speed and high temperature and high speed due to shortening of processing time.

[0003] Conventionally, when manufacturing a polycarbonate resin by melting and extruding it into a film using a plurality of cooling rolls, while supplying the molten polycarbonate resin between the first roll and the central second roll of the cooling roll, sandwiching and pressurizing it with the two rolls and then passing it through the gap of the third roll at the other end and then taking it out, the film manufactured by the double-sided touch method is surface-treated and used, such as applying a hard coat treatment such as coating a coating layer on at least one side to impart abrasion resistance, or performing screen printing or thermal transfer printing in nameplate applications such as automotive instrument covers and front panels of electrical products. Furthermore, the product described above is also used as a film for insert molding, but the thickness unevenness on the film surface has become a problem in terms of appearance.

[0004] Film thickness unevenness includes thickness unevenness occurring in the extrusion direction and thickness unevenness occurring in the direction perpendicular to the extrusion direction, i.e., the width direction. In particular, in the case of a polycarbonate resin film, when the film is surface-treated, the appearance of the processed product has a linear streak pattern, i.e., a gear mark, that periodically appears perpendicular to the extrusion direction of the film, or when peeling from the cooling roll during the film manufacturing process, adhesion unevenness (TD streak) occurs, resulting in problems such as the appearance of the film being deteriorated due to horizontal stripes or TD linear unevenness occurring in the film width direction (TD direction), or the product appearance becoming poor due to the film thickness unevenness.

[0005] Also, when the molten resin extruded from the T-die is crimped by the cooling roll, the variation in thickness occurring at close positions in the film width direction is large, resulting in problems such as printing omission due to thickness unevenness occurring in the film extrusion direction, and the value of the product being significantly reduced.

[0006] Furthermore, the film manufactured by the double-sided touch method described above often causes various problems depending on the application due to the defects occurring in the film. When performing surface treatment to impart high functionality, it is important to ensure that the film has no defects in terms of quality. In applications in this field, if the film has defects of a size visible to the naked eye, its use is difficult and it is restricted to special applications.

[0007] In the case of a polycarbonate resin film, various surface treatments are often applied to at least one side to impart high functionality. When the film is surface-treated, the appearance of the processed product is deteriorated due to thickness unevenness occurring in the vicinity in the film extrusion direction, and furthermore, even though the film has no visible defects, the processed film has fine defects, such as cracking of the hard coat film, uneven film thickness, or color omission in thermal transfer printing using thin-film ink for printing, which is not preferable and causes problems such as a significant reduction in appearance and the value of the product.

[0008] Patent Document 1 discloses a film using one or more resin components selected from the group consisting of a polycarbonate resin component, a polyester block copolymer, and an alicyclic polyester. However, it does not disclose obtaining a film with excellent printability.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0010] An object of the present invention is to provide a polycarbonate resin composition film and a decorative film having small thickness unevenness, excellent surface properties, and excellent printing characteristics.

Means for Solving the Problems

[0011] As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be achieved by controlling the variation in film thickness formed from a polycarbonate resin composition containing a polycarbonate resin component and a thermoplastic elastomer component within a specific range, and have reached the present invention.

[0012] That is, according to the present invention, the problems of the present invention are achieved by the following items 1 to 5. 1. A film having a thickness of 0.1 mm to 0.5 mm formed from a polycarbonate resin composition containing (A) a polycarbonate resin component (component a) and (B) a thermoplastic elastomer component (component b), wherein the a component is 70 to 98% by weight and the b component is 30 to 2% by weight in a total of 100% by weight of the a component and the b component, and the absolute value of the thickness tolerance ΔTDn of adjacent measurement points of the film measured by the method described in the text is 15 μm or less, and the absolute value of the tolerance ΔTDa from the arithmetic mean value of the thickness of each measurement point of the film measured by the method described in the text is 10 μm or less. 2. The number of film appearance (dents) defects with a size exceeding 250 μm is 1 per 10 m 2 per 10 m 2 The film according to item 1 above, where the number is as follows. 3. The thermoplastic elastomer is a thermoplastic elastomer composed of a hard segment mainly consisting of polybutylene terephthalate units and a soft segment consisting of polyester units having an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid as dicarboxylic acid components and a diol having 5 to 15 carbon atoms as a diol component, as described in item 1 or item 2 above. 4. The film according to any one of items 1 to 3 above, which is formed by melt-extruding the polycarbonate resin composition according to any one of items 1 to 3 above from a T-die equipped with dam plates at both ends and cooling it by a double-sided touch method. 5. A decorative film in which at least one surface of the film according to any one of items 1 to 4 above is printed.

Advantages of the Invention

[0013] The polycarbonate resin composition film and the decorative film of the present invention have excellent surface characteristics by controlling the thickness in the film width direction when manufacturing the film. More preferably, by controlling the size and number of defects in the resin to be formed within a certain range, there are fewer appearance defects during thin film printing, and any defects in the appearance are less noticeable, making it extremely useful for thin film printing, and its industrial effect is remarkable.

Brief Description of the Drawings

[0014]

Figure 1

Modes for Carrying Out the Invention

[0015] Hereinafter, the present invention will be described in detail.

[0016] The present invention relates to a film with a thickness of 0.1 mm to 0.5 mm formed from a polycarbonate resin composition containing (A) a polycarbonate resin component (component a) and (B) a thermoplastic elastomer component (component b), wherein in a total of 100% by weight of component a and component b, component a is 70 to 98% by weight and component b is 3 to 2% by weight, and the absolute value of the thickness tolerance ΔTDn between adjacent measurement points of the film measured by the method described in the text satisfies 15 μm or less, and the absolute value of the tolerance ΔTDa from the arithmetic mean value of the thickness of each measurement point of the film measured by the method described in the text satisfies 10 μm or less.

[0017] (Polycarbonate resin component (component a)) The (A) polycarbonate resin (component a), which is one of the constituent components of the polycarbonate resin composition film of the present invention, will be described. The polycarbonate resin used in the present invention is obtained by reacting a dihydric phenol with a carbonate precursor. Examples of the reaction method include the interfacial polymerization method, the melt transesterification method, the solid-phase transesterification method of a carbonate prepolymer, and the ring-opening polymerization method of a cyclic carbonate compound.

[0018] Typical examples of the dihydric phenol include hydroquinone, resorcinol, 4,4′-biphenol, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A), 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 2,2-bis(4-hydroxyphenyl)pentane, 4,4′-(p-phenylenediisopropylidene)diphenol, 4,4′-(m-phenylenediisopropylidene)diphenol, 1,1-bis(4-hydroxyphenyl)-4-isopropylcyclohexane, bis(4-hydroxyphenyl)oxide, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)ketone, bis(4-hydroxyphenyl)ester, 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, bis(3,5-dibromo-4-hydroxyphenyl)sulfone, bis(4-hydroxy-3-methylphenyl)sulfide, 9,9-bis(4-hydroxyphenyl)fluorene, and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene. Preferred dihydric phenol is bis(4-hydroxyphenyl)alkane, and among them, bisphenol A is particularly preferred because of its excellent strength, moderate heat resistance, easy availability, and low cost.

[0019] As the carbonate precursor, carbonyl halide, carbonic acid diester, haloformate, etc. are used, and specifically, phosgene, diphenyl carbonate, dihaloformate of dihydric phenol, etc. are mentioned.

[0020] When producing a polycarbonate resin from the above-mentioned dihydric phenol and carbonate precursor by the interfacial polymerization method, a catalyst, a terminal stopper, an antioxidant for preventing oxidation of the dihydric phenol, etc. may be used as necessary. The polycarbonate resin may be a branched polycarbonate resin copolymerized with a polyfunctional aromatic compound having three or more functional groups, a polyester carbonate resin copolymerized with an aromatic or aliphatic difunctional carboxylic acid, or a mixture of two or more of the obtained polycarbonate resins.

[0021] As the polyfunctional aromatic compound having three or more functional groups, 1,1,1-tris(4-hydroxyphenyl)ethane, 1,1,1-tris(3,5-dimethyl-4-hydroxyphenyl)ethane, etc. can be used.

[0022] When containing a polyfunctional compound that produces a branched polycarbonate, such a ratio is 0.001 to 1 mol%, preferably 0.005 to 0.5 mol%, particularly preferably 0.01 to 0.3 mol% in the total amount of the aromatic polycarbonate. Also, particularly in the case of the melt transesterification method, a branched structure may occur as a side reaction, and for such an amount of the branched structure, it is also preferably 0.001 to 1 mol%, preferably 0.005 to 0.5 mol%, particularly preferably 0.01 to 0.3 mol% in the total amount of the aromatic polycarbonate. Note that such a ratio can be calculated by 1H-NMR measurement.

[0023] The aliphatic difunctional carboxylic acid is preferably an α,ω-dicarboxylic acid. Examples of the aliphatic difunctional carboxylic acid preferably include linear saturated aliphatic dicarboxylic acids such as sebacic acid (decanedioic acid), dodecanedioic acid, tetradecanedioic acid, octadecanedioic acid, and icosanedioic acid.

[0024] Furthermore, it is also possible to use a polycarbonate-polyorganosiloxane copolymer copolymerized with polyorganosiloxane units.

[0025] The reaction by the interfacial polymerization method is usually a reaction between a dihydric phenol and phosgene, and the reaction is carried out in the presence of an acid binder and an organic solvent. As the acid binder, for example, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, pyridine, etc. are used.

[0026] As the organic solvent, for example, halogenated hydrocarbons such as methylene chloride and chlorobenzene are used.

[0027] Also, for promoting the reaction, catalysts such as tertiary amines and quaternary ammonium salts can be used, and as the molecular weight regulator, it is preferable to use monofunctional phenols such as phenol, p-tert-butylphenol, p-cumylphenol, etc. Further, as the monofunctional phenols, decylphenol, dodecylphenol, tetradecylphenol, hexadecylphenol, octadecylphenol, eicosylphenol, docosylphenol, triacontylphenol, etc. can be mentioned. These monofunctional phenols having relatively long-chain alkyl groups are effective when improvement in fluidity and hydrolysis resistance is required.

[0028] The reaction temperature is usually 0 to 40°C, the reaction time is several minutes to 5 hours, and it is preferable to keep the pH during the reaction at 10 or more.

[0029] The reaction by the melting method is usually a transesterification reaction between a dihydric phenol and a carbonic acid diester. The dihydric phenol and the carbonic acid diester are mixed in the presence of an inert gas and reacted under reduced pressure usually at 120 to 350°C. The degree of reduced pressure is changed stepwise, and finally, it is made 133 Pa or less to remove the generated phenols out of the system. The reaction time is usually about 1 to 4 hours.

[0030] Examples of the carbonic acid diester include diphenyl carbonate, dinaphthyl carbonate, bis(diphenyl) carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, etc., and among them, diphenyl carbonate is preferable.

[0031] A polymerization catalyst can be used to accelerate the polymerization rate. Examples of the polymerization catalyst include hydroxides of alkali metals and alkaline earth metals such as sodium hydroxide and potassium hydroxide, hydroxides of boron and aluminum, alkali metal salts, alkaline earth metal salts, quaternary ammonium salts, alkoxides of alkali metals and alkaline earth metals, organic acid salts of alkali metals and alkaline earth metals, zinc compounds, boron compounds, silicon compounds, germanium compounds, organotin compounds, lead compounds, antimony compounds, manganese compounds, titanium compounds, zirconium compounds, and other catalysts commonly used in esterification reactions and transesterification reactions. The catalyst can be used alone or in combination of two or more. The usage amount of these polymerization catalysts is preferably 1×10 -8 ~1×10 -3 equivalent, more preferably 1×10 -7 ~5×10 -4 equivalent and is selected within this range.

[0032] In addition, in the polymerization reaction, in order to reduce phenolic end groups, compounds such as 2-chlorophenyl phenyl carbonate, 2-methoxycarbonyl phenyl phenyl carbonate, and 2-ethoxycarbonyl phenyl phenyl carbonate can be added in the latter stage or after the completion of the polycondensation reaction.

[0033] Furthermore, in the melt transesterification method, it is preferable to use a deactivator to neutralize the activity of the catalyst. The amount of such deactivator is preferably used at a ratio of 0.5 to 50 moles per 1 mole of the remaining catalyst. Also, it is used at a ratio of 0.01 to 500 ppm, more preferably 0.01 to 300 ppm, and particularly preferably 0.01 to 100 ppm with respect to the aromatic polycarbonate after polymerization. Preferred examples of the deactivator include phosphonium salts such as tetrabutylphosphonium dodecylbenzenesulfonate and ammonium salts such as tetraethylammonium dodecylbenzyl sulfate.

[0034] Details of reaction forms other than the above are also well known in books and patent gazettes.

[0035] The viscosity average molecular weight (M) of the polycarbonate resin is preferably from 13,000 to 40,000, more preferably from 15,000 to 35,000, still more preferably from 20,000 to 32,000, and particularly preferably from 22,000 to 28,000. When a polycarbonate resin having such a viscosity average molecular weight is used, the base film of the present invention is excellent in film formability and has good strength. The above polycarbonate resin may be obtained by mixing those having a viscosity average molecular weight outside the above range.

[0036] The viscosity average molecular weight (M) of the polycarbonate resin is determined from the specific viscosity (η sp ) of a solution prepared by dissolving 0.7 g of the polycarbonate resin in 100 ml of methylene chloride at 20 °C and inserting it into the following formula. η sp / c = [η] + 0.45 × [η] 2 c (where [η] is the intrinsic viscosity) [η] = 1.23 × 10 -4 M 0.83 c = 0.7

[0037] (Thermoplastic elastomer component (component (b))) As the thermoplastic elastomer used in the present invention, a polyester-based thermoplastic elastomer is preferable. The polyester-based thermoplastic elastomer is preferably composed of a hard segment made of polybutylene terephthalate units and a soft segment made of polyester units having an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid as dicarboxylic acid components and a diol having 5 to 15 carbon atoms as a diol component. Specifically, polyester elastomer (Nubilan manufactured by Teijin Chemicals Ltd.) can be mentioned.

[0038] (Hard segment) The hard segment is preferably a polyester segment in which the melting point of the polymer composed of the segment is preferably 150 °C or higher.

[0039] The hard segment is preferably composed mainly of polybutylene terephthalate units (preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more out of 100 mol% of all components). Polybutylene terephthalate has excellent compatibility with polycarbonate resins, is preferable in terms of transparency and thermoformability, and also has good properties in terms of strength and the like. Polybutylene terephthalate may contain other components as copolymerization components as long as the effects of the present invention are not impaired. The proportion of such copolymerization components is preferably 30 mol% or less, more preferably 20 mol% or less, still more preferably 10 mol% or less out of 100 mol% of each of the dicarboxylic acid component and the diol component.

[0040] (Soft segment) The soft segment refers to a segment in which the melting point of the polymer formed from the segment is preferably 100°C or lower, or which is liquid and amorphous at 100°C.

[0041] The soft segment is preferably a polyester composed of aromatic dicarboxylic acid and aliphatic dicarboxylic acid as the dicarboxylic acid component and a diol having 5 to 15 carbon atoms as the diol component (hereinafter sometimes referred to as "SS-1"). SS-1 is suitable because extremely good transparency can be obtained.

[0042] In the soft segment SS-1, the content of aromatic dicarboxylic acid is preferably 60 to 99 mol% and the content of aliphatic dicarboxylic acid is preferably 1 to 40 mol% out of 100 mol% in total of the dicarboxylic acid components, from the viewpoint of obtaining better transparency. More preferably, the content of aromatic dicarboxylic acid is 70 to 95 mol% and the content of aliphatic dicarboxylic acid is 5 to 30 mol%. Still more preferably, the content of aromatic dicarboxylic acid is 85 to 93 mol% and the content of aliphatic dicarboxylic acid is 7 to 15 mol%. Particularly preferably, the content of aromatic dicarboxylic acid is 89 to 92 mol% and the content of aliphatic dicarboxylic acid is 8 to 11 mol%.

[0043] As the aromatic dicarboxylic acid of SS-1, terephthalic acid and isophthalic acid are suitable, and isophthalic acid is particularly suitable from the viewpoint of reducing crystallinity. As the aliphatic dicarboxylic acid of SS-1, linear aliphatic dicarboxylic acids having 6 to 12 carbon atoms such as succinic acid, adipic acid, and sebacic acid are suitable, and sebacic acid is particularly suitable.

[0044] As the diol component having 5 to 15 carbon atoms of SS-1, linear aliphatic diols having 6 to 12 carbon atoms such as hexamethylene glycol, decamethylene glycol, 3-methylpentanediol, and 2-methyloctamethylene diol are preferable. Particularly, hexamethylene glycol is preferable.

[0045] SS-1 has high compatibility with the polycarbonate resin. Therefore, a laminate with high transparency can be obtained, and it is particularly preferable from the viewpoint that the surface properties and transparency after thermoforming are also good. More specifically, as SS-1, a polyester composed of an isophthalic acid and sebacic acid component and hexamethylene glycol is preferable.

[0046] In addition, in the polyester-based thermoplastic elastomer, the ratio of the hard segment to the soft segment is preferably 20 to 70% by weight of the hard segment and 80 to 30% by weight of the soft segment in 100% by weight of the elastomer, and more preferably 20 to 40% by weight of the hard segment and 80 to 60% by weight of the soft segment. The intrinsic viscosity (value measured at 35 ° C in o-chlorophenol) of the polyester-based thermoplastic elastomer is preferably 0.6 or more, more preferably in the range of 0.8 to 1.5, and even more preferably in the range of 0.8 to 1.2. When the intrinsic viscosity is within the above range, the strength of the laminate is sufficient, which is preferable.

[0047] The polyester-based thermoplastic elastomer can be obtained by reacting the above-described hard segment and soft segment by melt-kneading to form a multi-block copolymer.

[0048] The intrinsic viscosity of the polymer serving as the hard segment is preferably in the range of 0.2 to 2.0, more preferably in the range of 0.5 to 1.5. The intrinsic viscosity of the polymer serving as the soft segment is preferably in the range of 0.2 to 2.0, more preferably in the range of 0.5 to 1.5.

[0049] The reaction is preferably carried out in the range of 200 to 300 °C, more preferably in the range of 220 to 260 °C.

[0050] The number average molecular weights of the above-mentioned hard segment and soft segment that have been multi-blocked are each preferably in the range of 500 to 7,000, and more preferably in the range of 800 to 5,000.

[0051] (Weight ratio of component a and component b) In the present invention, the weight ratio of the (A) polycarbonate resin component (component a) to the (B) thermoplastic elastomer component (component b) is such that in a total of 100% by weight of components a and b, component a is 70 to 98% by weight and component b is 30 to 2% by weight. It is preferably that component a is 80 to 96% by weight and component b is 20 to 4% by weight, and more preferably that component a is 85 to 95% by weight and component b is 15 to 5% by weight. When within the above range, a polycarbonate resin composition film and a decorative film with small thickness unevenness, excellent surface properties, and excellent printing properties can be obtained.

[0052] (Other components) In the polycarbonate resin composition film of the present invention, various additives can be blended. Examples of the additives include heat stabilizers such as phosphorus-based heat stabilizers usually used in polycarbonate resins, antioxidants such as phenolic antioxidants and sulfur-based antioxidants, ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers and triazine-based ultraviolet absorbers, light stabilizers such as hindered amine-based light stabilizers, mold release agents such as saturated fatty acid esters, antistatic agents, and colorants such as pigments and dyes.

[0053] (Polycarbonate resin composition film) In the present invention, a film formed from a polycarbonate resin composition containing (A) a polycarbonate resin component (component a) and (B) a thermoplastic elastomer component (component b), wherein the component a is 70 to 98% by weight and the component b is 30 to 2% by weight in a total of 100% by weight of the component a and the component b, is a film having a thickness of 0.1 mm to 0.5 mm, and the absolute value of the thickness tolerance ΔTDn of adjacent measurement points of the film measured by the method described in the text satisfies 15 or less, and the absolute value of the tolerance ΔTDa from the arithmetic mean value of the thickness of each measurement point of the film measured by the method described in the text satisfies 10 or less.

[0054] (Film thickness) The film thickness in the present invention is in the range of 0.1 mm to 0.5 mm, preferably in the range of 0.11 mm to 0.45 mm, and more preferably in the range of 0.12 mm to 0.4 mm. The film having the above thickness can be suitably used as a decorative film.

[0055] (Absolute value of the thickness tolerance ΔTDn of adjacent measurement points of the film) In the present invention, the absolute value of the thickness tolerance ΔTDn of adjacent measurement points of the film is measured by using an outside micrometer defined in JIS B-7502, measuring the thickness every 35 mm in the width direction of the film, and using the film extrusion width excluding the ear portion. When the film thickness at the i-th position is TD(i) and the film thickness at the (i + 1)-th position is TD(i + 1), the absolute value of the thickness tolerance ΔTDn (μm) of adjacent measurement points of the film can be obtained by the following formula. |ΔTDn| = TD(i) - TD(i + 1)

[0056] The absolute value of the thickness tolerance ΔTDn of adjacent measurement points of the film is 15 μm or less, preferably 14 μm or less. The lower limit of the absolute value of ΔTDn is not particularly limited, but is preferably 1 μm or more. Within the above range, since the variation in the thickness of the entire film width is small, surface smoothness can be obtained, the thickness unevenness in the width direction is hardly noticeable, and the appearance of the decorative film printed on the film is excellent, which is preferable.

[0057] (Absolute value of the tolerance ΔTDa from the arithmetic mean value of the thickness of each measurement point on the film) In the present invention, the absolute value of the tolerance ΔTDa between the arithmetic mean value of the thickness at each measurement point on the film can be determined by measuring the thickness every 35 mm in the width direction of the film using an outside micrometer specified in JIS B-7502, and using the film thickness at the i-th measurement point across the extruded film width excluding the edge portions as TD(i) and the arithmetic mean thickness TDa, the absolute value of the tolerance ΔTDa (μm) between each measurement point on the film and the arithmetic mean thickness can be calculated using the following formula: |ΔTDa|=TD(i)-TDa

[0058] The absolute value of the tolerance ΔTDa from the arithmetic mean value of the thickness at each measurement point of the film is 10 μm or less. The lower limit of the absolute value of ΔTDa is not particularly limited, but it is preferably 1 μm or more. Within the above range, the variation in thickness across the entire width of the film is small, so that surface smoothness is obtained, thickness unevenness in the width direction becomes almost inconspicuous, and the appearance of the decorative film printed on the film is excellent, which is preferable.

[0059] (Film appearance (dent) defect) In the present invention, the number of appearance defects (dents) of the film exceeding 250 μm in size is 10 m 2 1 piece per 10m 2 Preferably less than 0 pieces / 10m 2 If the number of appearance defects (dents) exceeding 250 μm in size falls within the above range, when the film is used for surface treatment such as printing, the film defects after surface treatment are small and barely noticeable, and the appearance of the obtained surface-treated product, i.e., the perspective image, is not distorted, which is preferable because the value as a product is greatly improved.

[0060] Defect detection of the film can be performed by a sheet surface inspection device installed in the production line during film production. This sheet surface inspection device is composed of a light receiver that continuously detects defects and their sizes and determines the size of the defects in the flow direction, a light projector that irradiates the inspection surface with uniform brightness, and a controller that receives the film information and speed information sent from the light receiving part and performs defect determination. The size of the defects determined by the light receiver can be arbitrarily set.

[0061] On the other hand, the presence of defects with a size of 250 μm or less does not cause much visual problem. However, the number of appearance defects (dents) with a size exceeding 200 μm to 250 μm or less is 10 per 10 m 2 should preferably be 10 per 10 m 2 or less, more preferably 7 per 10 m 2 and the number of appearance defects (dents) with a size of 100 μm to 200 μm or less is preferably 20 per 10 m 2 per 10 m 2 or less, more preferably 15 per 10 m 2 is even more preferable.

[0062] (Method for manufacturing the film) Conventionally, as a method for manufacturing a polycarbonate resin composition film, it is common to cool the molten polycarbonate resin composition extruded from a T-die with a plurality of mirror surface cooling rolls by a double-sided touch method (clamping and pressurizing) or a single-sided touch method to form a film.

[0063] To manufacture the polycarbonate resin composition film of the present invention, it is preferable to add means such as a method of applying static electricity immediately after extruding the molten resin from the T-die, a method of providing weir plates at both ends of the T-die and protruding the weir plates 5 to 20 mm from the T-die lip surface, and a method of melt extrusion molding using a T-die with an R of the lip edge of 0.005 to 0.05 mm and a surface roughness Ra of 0.005 μm or less. Furthermore, a method combining a plurality of these means is preferable.

[0064] A preferred form used in the present invention will be described in more detail. One method will be described with reference to the drawings. FIG. 1 is a schematic view showing an example of an apparatus for manufacturing a film suitable for carrying out the method of the present invention. In the figure, 1 is a T-die, 2 is a first cooling roll, 3 is a second cooling roll, 4 is a third cooling roll, and 5 is a pair of take-up rolls (take-off rolls). The surfaces of the first to third cooling rolls are all mirror-finished, and a heat medium circulates inside so that the temperature can be controlled.

[0065] First, the molten polycarbonate resin composition is extruded into a sheet form from the T-die 1. No special conditions are required for this melt extrusion, and the normal melt extrusion conditions for a polycarbonate resin composition sheet are arbitrarily adopted. Next, the extruded sheet-like material is supplied as it is between the first cooling roll 2 and the second cooling roll 3 while being rolled by these two rolls or brought into close contact with the central second cooling roll 3, and then transferred to the third roll 4 at the other end, and then taken up by a pair of take-up rolls 5.

[0066] The R of the lip edge of the T-die is preferably 0.005 to 0.05 mm, more preferably 0.01 to 0.03 mm. The surface roughness Ra of the lip edge of the T-die is preferably 0.005 μm or less, more preferably 0.0001 to 0.005 μm, still more preferably 0.0002 to 0.003 μm, and particularly preferably 0.0003 to 0.002 μm. Also, the R of the lip edge of the T-die generally used in the past is 0.1 to 0.3 mm, and with such a T-die, there has been a problem that the molten polycarbonate resin adheres to the lip opening during long-term continuous molding, and die lines are observed on the film surface. However, by adopting a lip edge with an R of 0.05 mm or less for the lip edge, it is difficult for the resin to adhere, the film thickness unevenness becomes smaller, and the number of appearance (dents) defects also decreases. Also, it is desirable that the lip edge is symmetrical. If it is symmetrical, the molten resin film discharged from the lip opening contacts the roll without undulating when it falls, and it is preferable because it is difficult to cause a problem that undulations occur on the film surface. Further, if the surface roughness Ra of the lip edge of such a T-die is 0.005 μm or less, it is preferable because the film thickness unevenness of the obtained film becomes smaller and the number of appearance (dents) defects also decreases.

[0067] Generally, a T-die is manufactured by processing a metal angle bar with a cutting machine. The lip edge R portion and the portion having a predetermined surface roughness Ra of the T-die used in the present invention are subjected to a very precise polishing treatment as a surface finish, and further subjected to a plating treatment such as chromium plating for corrosion prevention. The surface roughness of the lip edge of the T-die in the present invention is the surface roughness of the edge portion from the lip opening to about 1 cm. Incidentally, the surface roughness of the lip edge portion can be substituted with the value obtained by measuring the surface roughness of the flat portion on the upper part of the inner surface of the lip opening from the lip edge portion having the same surface finish treatment as the lip edge portion.

[0068] (Decorative film) The polycarbonate resin composition film of the present invention has good suitability for surface treatments such as printing and hard coat treatments. Therefore, it can be suitably used as a film to be inserted into a mold when performing insert molding. For a decorative film having a surface treatment such as printing or hard coat treatment, when it is a decorative film with one side processed, the processed surface (or the desired surface in the case of double-sided processing) is placed on the mold surface side, and the film is set. Then, a thermoplastic resin can be injected and molded. The surface treatment layer such as printing or hard coat treatment may be a single layer or a multilayer. The thickness of these single or multilayer layers is generally 0.1 to 20 μm.

[0069] Examples of the material of the printing layer include colored inks that contain a resin such as a urethane-based resin (curing type), vinyl-based resin, polyamide-based resin, polyester-based resin, acrylic-based resin, polyurethane-based resin, polyvinyl acetate-based resin, polyester urethane-based resin, cellulose ester-based resin, alkyd resin, and other thermoplastic elastomers as a binder, and a pigment or dye of an appropriate color as a colorant.

[0070] Furthermore, when the heat resistance of the molding resin is high and its molding processing temperature is high, a resin binder with high heat resistance is required. On the other hand, since the film of the present invention has a polycarbonate resin as its main component, the polycarbonate resin is one of the suitable materials as the material of the printing layer in terms of adhesion. From this point, when the heat resistance of the molding resin is high, a colored ink using a polycarbonate with good heat resistance as a binder is a preferred embodiment.

[0071] As a printing method for forming the printing layer, known printing methods such as gravure printing, offset printing, flexographic printing, dry offset printing, pad printing, screen printing, and thermal transfer printing can be used according to the product shape and printing purpose. Particularly for multi-color printing and gradation expression, thermal transfer printing is suitable.

[0072] The polycarbonate resin composition film, decorative film of the present invention, and thermoplastic resin molded article having these films on the surface layer are widely used in nameplate applications, electrical components, building materials components, automotive components, etc., and specifically are suitably used for the front panel of a display, etc.

Examples

[0073] The present invention will be further described below with reference to examples. The evaluations in the examples were carried out according to the methods shown below.

[0074] (1) Thickness tolerance (absolute value) between adjacent measurement points of the film Using an outside micrometer specified in JIS B-7502, the thickness was measured every 35 mm in the width direction of the film. Excluding the ear portion, with the film extrusion width, when the film thickness at the i-th point is TD(i) and the film thickness at the (i + 1)-th point is TD(i + 1), the absolute value of the thickness tolerance ΔTDn (μm) between adjacent measurement points of the film was obtained by the following formula. |ΔTDn| = TD(i) ― TD(i + 1)

[0075] (2) Tolerance (absolute value) between each measurement point of the film and the arithmetic mean thickness Using an outside micrometer specified in JIS B-7502, the thickness was measured every 35 mm in the width direction of the film. Excluding the ear portion, with the film extrusion width, when the film thickness at the i-th point is TD(i), from the arithmetic mean thickness TDa, the absolute value of the tolerance ΔTDa (μm) between each measurement point of the film and the arithmetic mean thickness was obtained by the following formula. |ΔTDa| = TD(i) - TDa

[0076] (3) Detection and measurement of appearance (dents) defects 10 m of the film obtained in the example 2 The defects per meter were detected with a defect detector, and the size and number of the defects contained in the film were counted.

[0077] (4) Appearance after printing After heat transfer printing the film obtained in the example, its appearance was evaluated, and it was indicated as ○ when there were no defects and × when appearance defects (pinholes) were confirmed.

[0078] [Example 1] A polycarbonate resin (Panlite L-1250WP manufactured by Teijin Chemicals Ltd.) and a polyester elastomer (Nubelan TRB-EL2 manufactured by Teijin Chemicals Ltd.) were mixed at the compounding ratios shown in Table 1, and then a polycarbonate resin composition film was produced using an extruder equipped with the apparatus shown in Fig. 1.

[0079] Dam plates were installed at both ends of a T-die with an R of the lip edge of 0.02 mm and a surface roughness of 0.001 μm. The lip width of the T-die was 950 mm and the lip opening was 1 mm. The cooling rolls were composed of three rolls as shown in Fig. 1, and a structure was used in which the refrigerant was circulated and controlled so that the surface temperature of the rolls was uniform. The temperature of the first cooling roll was 85°C, the temperature of the second cooling roll was 120°C, the temperature of the third cooling roll was 90°C, and the peripheral speed R1 of the first cooling roll was 3 m / min. The molten resin discharged in film form from the T-die was successively externally tangent to the first cooling roll, the second cooling roll, and the third cooling roll. After peeling from the third cooling roll, the film was taken up via a take-off roll, and both ends were cut off by 150 mm each to obtain a film with a width of 600 mm and a thickness of 0.25 mm, and a wound laminate was obtained. The evaluation results of the obtained film are shown in Table 1.

[0080] Also, the obtained film was cut out to a width of 250 mm, and a transfer film with an image formed was produced by transferring the ink of a thermal transfer ribbon using the thermal head of a thermal transfer printer. The appearance of the transfer film was evaluated, and the results are shown in Table 1.

[0081] [Example 2] In Example 1, a film with a thickness of 0.25 mm was obtained in the same manner as in Example 1 except that the peripheral speed R1 of the first cooling roll was 2.4 m / min. The evaluation results of the obtained film are shown in Table 1.

[0082] Further, the obtained film was cut into pieces with a width of 250 mm, and a transfer film with an image formed thereon was produced by transferring the ink of a thermal transfer ribbon using the thermal head of a thermal transfer printer. The appearance of the transfer film was evaluated, and the results are shown in Table 1.

[0083] [Example 3] A polycarbonate resin (Panlite L-1250WP manufactured by Teijin Chemicals Ltd.) and a polyester elastomer (Nuvelan TRB-EL2 manufactured by Teijin Chemicals Ltd.) were mixed at the compounding ratios shown in Table 1, and a polycarbonate resin composition film was produced using an extruder equipped with the apparatus shown in FIG. 1.

[0084] Dam plates were installed at both ends of a T-die with an R of the lip edge of 0.02 mm and a surface roughness of 0.001 μm. The lip width of the T-die was 950 mm, and the lip opening was 1 mm. The cooling rolls were configured with three rolls as shown in FIG. 1, and a structure in which the refrigerant was circulated and controlled so that the surface temperature of the rolls was uniform was used. The temperature of the first cooling roll was 80°C, the temperature of the second cooling roll was 115°C, the temperature of the third cooling roll was 90°C, and the peripheral speed R1 of the first cooling roll was 1.9 m / min. The molten resin discharged in a film shape from the T-die was sequentially externally tangent to the first cooling roll, the second cooling roll, and the third cooling roll. After peeling from the third cooling roll, the film was taken up via a take-off roll, and both ends were cut off by 150 mm each to obtain a film with a width of 600 mm and a thickness of 0.4 mm, and a wound body was obtained. The evaluation results of the obtained film are shown in Table 1.

[0085] Further, the obtained film was cut into pieces with a width of 250 mm, and a transfer film with an image formed thereon was produced by transferring the ink of a thermal transfer ribbon using the thermal head of a thermal transfer printer. The appearance of the transfer film was evaluated, and the results are shown in Table 1.

[0086] [Example 4] The polycarbonate resin (Panlite L-1250WP manufactured by Teijin Chemicals Ltd.) and the polyester elastomer (Nubelan TRB-EL2 manufactured by Teijin Chemicals Ltd.) were mixed at the compounding ratios shown in Table 1, and then a polycarbonate resin composition film was produced using an extruder equipped with the apparatus shown in Fig. 1.

[0087] Weirs were installed at both ends of a T-die with an R of the lip edge of 0.02 mm and a surface roughness of 0.001 μm. The lip width of the T-die was 950 mm and the lip opening was 1 mm. The cooling rolls were configured in three as shown in Fig. 1, and a structure was used in which the refrigerant was circulated and controlled so that the surface temperature of the rolls was uniform. The temperature of the first cooling roll was 80 °C, the temperature of the second cooling roll was 115 °C, the temperature of the third cooling roll was 90 °C, and the peripheral speed R1 of the first cooling roll was 5.0 m / min. The molten resin discharged in film form from the T-die was successively externally tangent to the first cooling roll, the second cooling roll, and the third cooling roll. After peeling off from the third cooling roll, the film was taken up via a take-off roll, and both ends were cut off by 150 mm each to obtain a film with a width of 600 mm and a thickness of 0.125 mm, and a wound body was obtained. The evaluation results of the obtained film are shown in Table 1.

[0088] Also, the obtained film was cut out to a width of 250 mm, and a transfer film with an image formed thereon was produced by transferring the ink of a thermal transfer ribbon using the thermal head of a thermal transfer printer. The appearance of the transfer film was evaluated, and the results are shown in Table 1.

[0089] [Comparative Example 1] The polycarbonate resin (Panlite L-1250WP manufactured by Teijin Chemicals Ltd.) and the polyester elastomer (Nubelan TRB-EL2 manufactured by Teijin Chemicals Ltd.) were mixed at the compounding ratios shown in Table 1, and then a polycarbonate resin composition film was produced using an extruder equipped with the apparatus shown in Fig. 1.

[0090] We installed weir plates at both ends of a T-die with an R of the lip edge of 0.1 mm and a surface roughness of 0.01 μm, and set the lip width of the T-die to 950 mm and the lip opening to 1 mm. The cooling rolls were composed of three rolls as shown in Fig. 1, and we used a structure in which the refrigerant was circulated and controlled so that the surface temperature of the rolls was uniform. We set the temperature of the first cooling roll to 85 °C, the temperature of the second cooling roll to 120 °C, the temperature of the third cooling roll to 90 °C, and the peripheral speed R1 of the first cooling roll to 3 m / min. The molten resin discharged in a film shape from the T-die successively circumscribed the first cooling roll, the second cooling roll, and the third cooling roll. After peeling off from the third cooling roll, the film was taken up via a take-off roll, and both ends were cut off by 150 mm each to obtain a film with a width of 600 mm and a thickness of 0.25 mm, and a wound laminate was obtained. The evaluation results of the obtained film are shown in Table 1.

[0091] Also, the obtained film was cut into pieces with a width of 250 mm, and a transfer film with an image formed thereon was produced by transferring the ink of a thermal transfer ribbon using the thermal head of a thermal transfer printer. The appearance of the transfer film was evaluated, and the results are shown in Table 1.

[0092] [Comparative Example 2] In Comparative Example 1, a film with a thickness of 0.25 mm was obtained in the same manner as in Comparative Example 1 except that the peripheral speed R1 of the first cooling roll was set to 2.4 m / min, and a wound laminate was obtained. The evaluation results of the obtained film are shown in Table 1.

[0093] Also, the obtained film was cut into pieces with a width of 250 mm, and a transfer film with an image formed thereon was produced by transferring the ink of a thermal transfer ribbon using the thermal head of a thermal transfer printer. The appearance of the transfer film was evaluated, and the results are shown in Table 1.

[0094] [Comparative Example 3] After mixing polycarbonate resin (Panlite L-1250WP manufactured by Teijin Chemicals Ltd.) and polyester elastomer (Nuvelan TRB-EL2 manufactured by Teijin Chemicals Ltd.) at the compounding ratios shown in Table 1, a polycarbonate resin composition film was produced using an extruder equipped with the apparatus shown in Fig. 1.

[0095] We installed weir plates at both ends of a T-die with an R of the lip edge being 0.1 mm and a surface roughness of 0.01 μm. The lip width of the T-die was 950 mm and the lip opening was 1 mm. The cooling rolls were composed of three rolls as shown in Figure 1, and we used a structure in which the refrigerant was circulated and controlled so that the surface temperature of the rolls was uniform. The temperature of the first cooling roll was set at 80 °C, the temperature of the second cooling roll was 115 °C, the temperature of the third cooling roll was 90 °C, and the peripheral speed R1 of the first cooling roll was 1.9 m / min. The molten resin discharged in a film shape from the T-die was successively externally tangent to the first cooling roll, the second cooling roll, and the third cooling roll. After peeling off from the third cooling roll, the film was taken up via a take-off roll, and both ends were cut off by 150 mm each to obtain a film with a width of 600 mm and a thickness of 0.4 mm, and a wound laminate was obtained. The evaluation results of the obtained film are shown in Table 1.

[0096] Also, the obtained film was cut into pieces with a width of 250 mm, and a transfer film with an image formed thereon was produced by transferring the ink of a thermal transfer ribbon using the thermal head of a thermal transfer printer. The appearance of the transfer film was evaluated, and the results are shown in Table 1.

[0097] [Comparative Example 4] A polycarbonate resin film was produced from a polycarbonate resin (Panlite L-1250WP manufactured by Teijin Chemicals Ltd.) using an extruder equipped with the apparatus shown in Figure 1.

[0098] We installed weir plates at both ends of a T-die with an R of the lip edge of 0.1 mm and a surface roughness of 0.01 μm. The lip width of the T-die was 950 mm and the lip opening was 1 mm. The cooling rolls were composed of three rolls as shown in Fig. 1, and a structure was used in which the refrigerant was circulated and controlled so that the surface temperature of the rolls was uniform. The temperature of the first cooling roll was 110°C, the temperature of the second cooling roll was 115°C, the temperature of the third cooling roll was 140°C, and the peripheral speed R1 of the first cooling roll was 3.1 m / min. The molten resin discharged in a film shape from the T-die was successively externally tangent to the first cooling roll, the second cooling roll, and the third cooling roll. After peeling off from the third cooling roll, the film was taken up via a take-off roll, and both ends were cut off by 150 mm each to obtain a film with a width of 600 mm and a thickness of 0.25 mm, and a wound laminate was obtained. The evaluation results of the obtained film are shown in Table 1.

[0099] In addition, the obtained film was cut into pieces with a width of 250 mm, and a transfer film with an image formed thereon was produced by transferring the ink of a thermal transfer ribbon using the thermal head of a thermal transfer printer. The appearance of the transfer film was evaluated, and the results are shown in Table 1.

[0100]

Table 1

Industrial Applicability

[0101] The film of the present invention has few appearance defects during thin film printing processing, and the existing defects in the appearance are also less noticeable, and it is extremely useful as a film for thin film printing.

Explanation of Signs

[0102] 1 T-die 2 First cooling roll 3 Second cooling roll 4 Third cooling roll 5 Pair of take-up rolls (take-off rolls)

Claims

1. A film with a thickness of 0.1 mm to 0.5 mm formed from a polycarbonate resin composition containing (A) a polycarbonate resin component (component a) and (B) a thermoplastic elastomer component (component b), wherein in a total of 100% by weight of component a and component b, component a is 70 to 98% by weight and component b is 30 to 2% by weight, and the absolute value of the thickness tolerance ΔTDn between adjacent measurement points of the film measured by the method described in the text satisfies 15 μm or less, and the absolute value of the tolerance ΔTDa from the arithmetic mean value of the thickness of each measurement point of the film measured by the method described in the text satisfies 10 μm or less.

2. The number of film appearance (dent) defects with a size exceeding 250 μm is 1 per 10 m ２ per 10 m ２ The film according to claim 1, wherein the number is as follows

3. The film according to Claim 1, wherein the thermoplastic elastomer is composed of a hard segment mainly composed of polybutylene terephthalate units and a soft segment composed of polyester units having an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid as dicarboxylic acid components and a diol having 5 to 15 carbon atoms as a diol component.

4. The film according to Claim 1, formed by a method of melt-extruding the polycarbonate resin composition according to Claim 1 from a T-die provided with dam plates at both ends and cooling by a double-sided touch method.

5. A decorative film in which at least one surface of the film according to any one of Claims 1 to 4 is printed.

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