JP2006289710A - Slidable polyester laminate having antistatic performance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make excellent antistatic performance and sliding performance coexist without spoiling the processing characteristics including transparency, printability, and adhesive properties of an A-PET sheet. <P>SOLUTION: A polyester laminate comprises a layer (A) in which 0.01-1 wt.% of inorganic particles having an average particle size of secondary particles of 2-20 μm, 0.1-2.0 wt.% of an ester product obtained from a polyhydric alcohol having at least three hydroxyl groups and a ≥12C aliphatic monocarboxylic acid, 0.2-3 wt.% of a polyoxydialkylene glycol having a number average mol.wt. of 500-5,000 at least one terminal of which is blocked, and 0.2-3 wt.% of a lithium metal-containing compound are incorporated in a polyester with an intrinsic viscosity of 0.5-1.1 and a layer (B) of the polyester of an intrinsic viscosity of 0.5-1.1. The layer (A) is laminated on at least one side of the sheet, and the thickness of the layer (A) is 1-50% of the thickness of the entire sheet. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polyester laminate having both excellent antistatic performance and slipperiness without impairing the processing properties such as transparency, printability and adhesiveness inherent to A-PET sheets.

  Amorphous polyester sheets called A-PET sheets are attracting attention for their excellent recyclability, low pollution, and food safety, and their usage is rapidly increasing. This polyester sheet is used as a blister bag for food and medicine containers and miscellaneous goods by thermoforming, and it is used as a clear case for cosmetics, electrical equipment, etc. taking advantage of its excellent transparency.

  Conventionally, such saturated polyester sheets are blocked by the inherent tackiness of the polyester resin, and it has been difficult to take them out one by one during transportation. In addition, the cutting property when the sheets are bundled is remarkably poor, and the sheet cannot be used as a single-sheet product such as used in vinyl chloride.

  Therefore, a combination of inorganic particles having a specific particle size, an ester product of a polyhydric alcohol having 3 or more hydroxyl groups and an aliphatic monocarboxylic acid having 12 or more carbon atoms (for example, see Patent Documents 1 to 4). )), It is possible to impart excellent slipperiness and cutting properties without impairing the processing characteristics such as transparency and printability and adhesiveness inherent to the A-PET sheet. It came to be used.

  The clear case of A-PET has high transparency and gloss, and has a high-class feeling. However, when it is displayed in a showcase for a long time, it will improve because the dust will be attached by static electricity and the product will appear dirty. Has been asked. It is difficult to impart antistatic performance by kneading because the film-forming temperature of the A-PET sheet is as high as 250 ° C. or higher, so that it is difficult to add a general surfactant. Therefore, it is usually considered as a conventional means to apply a cationic surfactant to the sheet, but if there is a small amount of antistatic agent applied to the sheet surface, the ink adhesion suitability and adhesive strength decrease due to the adhesive, Decrease in slipperiness occurs. On the other hand, if there is little coating, stable antistatic performance cannot be imparted. In this way, when the antistatic agent is applied, even if there is a slight variation, the suitability of processing greatly fluctuates, which makes the sheet quality unstable and becomes a problem.

  As a method for imparting antistatic performance to the A-PET sheet without reducing the processing suitability, a method of kneading an anionic surfactant (for example, see Patent Documents 5 to 7) can be considered. When an ester product with a carboxylic acid and an anionic surfactant are used together and kneaded into a polyester resin, it is impossible to achieve both antistatic performance and sliding performance. More specifically, when the amount of the ester product with the aliphatic monocarboxylic acid is increased, the slipping property is improved, but the antistatic performance is not exhibited at all, while the amount of the anionic surfactant is increased. Then, the antistatic performance is gradually improved, but the slipperiness is remarkably lowered.

  By using a combination of an antistatic agent and polyoxyalkylene glycol (for example, refer to Patent Documents 8 to 10), the improvement of dispersibility and bleedout were promoted, and the compatibility between slipperiness and antistatic performance was studied. The polyoxyalkylene glycol component used in these methods has a relatively large molecular weight, and it has been found that the transparency of the sheet is impaired even if the amount added is small. Also, the antistatic performance is insufficient, and it has been found that the antistatic performance is not at a practical level in a low temperature and low humidity environment.

  In addition, in order to improve transparency, the combined use of a polyoxyalkylene glycol having a relatively low molecular weight and an anionic surfactant (for example, see Patent Document 11) was also studied. Since it is decomposed, it cannot be actually used, and it has been found that its performance is insufficient.

  As described above, it is extremely difficult to achieve both slipperiness and antistatic performance without impairing the processing properties such as excellent transparency and printing suitability inherent in the A-PET sheet, and improvement is strongly desired. It was.

JP-A-7-224176 JP-A-8-142293 JP-A-8-156210 JP-A-8-157619 Japanese Examined Patent Publication No. 47-40873 JP-A-54-3848 JP-A-55-5938 JP 52-47071 A JP 58-12910 A JP-A-2-232257 JP 52-47072 A

  As a result of intensive investigations to solve such conventional problems, the present inventors have produced esters of polyester having inorganic particles having a specific secondary particle system, a specific polyhydric alcohol and an aliphatic monocarboxylic acid. The present invention has found that excellent slipperiness and antistatic performance can be achieved by blending a specific amount of an end-capped polyoxyalkylene glycol having a specific number average molecular weight and a lithium metal-containing compound. .

  That is, the present invention comprises (A) polyester having an intrinsic viscosity of 0.5 to 1.1, 0.01 to 1% by weight of inorganic particles having an average secondary particle diameter of 2 to 20 μm, and 3 or more hydroxyl groups. 0.1 to 2.0% by weight of an ester product of a polyhydric alcohol and an aliphatic monocarboxylic acid having 12 or more carbon atoms, and a poly having at least one end blocked with a number average molecular weight of 500 to 5000 It is composed of a layer containing 0.2 to 3% by weight of oxyalkylene glycol and 0.2 to 3% by weight of a lithium metal-containing compound, and (B) a layer made of polyester having an intrinsic viscosity of 0.5 to 1.1. The (A) layer is laminated on at least one side, and the (A) layer is a polyester laminate in the range of 1 to 50% of the entire sheet thickness.

  As described above, according to the present invention, a polyester laminate having both excellent antistatic performance and slipperiness without impairing the processing characteristics such as transparency, printability and adhesiveness inherent to A-PET. Can provide the body.

  Hereinafter, the present invention will be described in detail.

The polyester used in the layers (A) and (B) of the present invention can be obtained by polycondensing a dicarboxylic acid component containing terephthalic acid as a main component and ethylene glycol. From the economical point of view, homo-PET is preferable, but when heat sealability, solvent adhesion, and the like are required, there is no problem in introducing a copolymer component.

  For example, a part of the terephthalic acid component is substituted with one or more other dicarboxylic acid components such as isophthalic acid, adipic acid, diphenylcarboxylic acid, diphenyl ether dicarboxylic acid, diphenylsulfone dicarboxylic acid, sebacic acid, naphthalenedicarboxylic acid, etc. Copolyesters in which a part of the glycol component is substituted with one or more other glycol components such as diethylene glycol, hexamethylene glycol, trimethylene glycol, propylene glycol, cyclohexanedimethanol, neopentyl glycol, styrene glycol and the like are included.

  The total proportion of the copolymerized components of the polyester is preferably 50 mol% or less with respect to the total acid components. In addition, a trifunctional or higher functional compound or a monofunctional compound may be included within a range that is considered to be substantially linear. Furthermore, a heat stabilizer, a fluidity improver, an ultraviolet absorber, an antistatic agent, an antifogging agent, and the like can be added to the polyester as long as transparency is not lowered. Moreover, when matting is required, coloring agents, such as titanium dioxide, a calcium carbonate, iron oxide, and carbon black, can also be contained.

  The intrinsic viscosity of the polyester used in the present invention needs to be 0.5 to 1.1, particularly preferably 0, as measured in a phenol / tetrachloroethane mixed solvent having a weight ratio of 60/40 at 20 ° C. .6 or more. If it is less than 0.5, the mechanical strength of the final product is not sufficient, and particularly the impact strength at low temperatures and the ductility at the time of bending the clear case are not sufficient. On the other hand, when the intrinsic viscosity exceeds 1.1, not only is the economic efficiency inferior, but the melt moldability at the time of sheet formation becomes difficult.

  Although sheet thickness is not specifically limited, Usually, it is 50-1500 micrometers, Preferably it is 150-800 micrometers.

  Next, the inorganic particles used in the present invention are talc, silica, calcium carbonate, alumina, wollastonite, kaolin, zinc oxide, barium sulfate, calcium phosphate, aluminum hydroxide, terephthalates such as Ca, Ba, Zn, Mn, An example is a crosslinked polymer, and inorganic particles close to the refractive index of amorphous polyester are advantageous in terms of transparency.

  These may be used alone or in combination, and added as a slurry at the time of polymerization in order to disperse uniformly in the sheet, or within the range that does not reduce the transparency of the sheet, inorganic such as olefin wax, fatty acid, fatty acid metal salt, etc. You may perform the surface treatment of particle | grains. In order to prevent the occurrence of scratches due to sheet friction, it is effective to use inorganic particles having a Mohs hardness of 5 or less, for example, crosslinked particles such as polystyrene and polymethyl methacrylate.

  The inorganic particles need 0.01 to 1% by weight of fine particles having an average secondary particle diameter of 2 to 20 μm, and preferably 0.05 to 0.5% by weight of fine particles of 3 to 10 μm. Although it is sufficiently possible to impart slipperiness only by blending fine particles having an average particle size of 2 to 10 μm, a synergistic effect is exhibited by using particles having a slightly larger particle size of 10 to 20 μm in combination with a small amount of inorganic particles. It is also possible to impart slipperiness.

When the average particle size of the inorganic particles is less than 2 μm or the blending amount is less than 0.01% by weight, the unevenness per sheet unit area is insufficient or the unevenness is low, and the slipperiness is insufficient and the sheets are overlapped. Blocking occurs. In the case of using an antistatic agent together, it is effective to increase the number of irregularities slightly larger and larger per unit area than a general slip sheet. When the average particle size of the inorganic particles exceeds 20 μm or the blending amount exceeds 1% by weight, the decrease in the transparency of the sheet and the generation of scratches during sheet conveyance are extremely undesirable.

  The ester product used in the present invention must be composed of a polyhydric alcohol having 3 or more hydroxyl groups and an aliphatic monocarboxylic acid having 12 or more carbon atoms. An ester product composed of an alcohol having less than three hydroxyl groups of a polyhydric alcohol has good compatibility with the polyester, and therefore the amount of bleed out to the sheet surface is small and sufficient slipperiness cannot be provided. Examples of the polyhydric alcohol having 3 or more hydroxyl groups include glycerin, pentaerythritol, sorbitol, xylitol, mannitol and the like.

  In addition, when the aliphatic monocarboxylic acid used to obtain the ester product has less than 12 carbon atoms, the ester product has insufficient heat resistance, and when blended with polyester or the like, Not only does the hydrolysis occur by heating and the slippery effect is very low, but the mechanical properties of the sheet itself are also very low.

  Such aliphatic monocarboxylic acids having 12 or more carbon atoms include tridecylic acid, myristic acid, pentadesilylic acid, palmitic acid, margaric acid, stearic acid, nonadesilylic acid, arachidic acid, heneysancoic acid, behenic acid, tricosanoic acid, lignoceric acid Pentacosanoic acid, serotic acid, heptacosanoic acid, montanic acid, nonacosanoic acid, melicic acid and the like.

  The amount of the ester product necessary for giving good slipperiness to the sheet is 0.1 to 2% by weight, preferably 0.2 to 1% by weight, and more preferably 0.3 to 0. 6% by weight. If the blending amount is less than 0.1% by weight, sufficient slipperiness cannot be provided. Further, when the blending amount exceeds 2% by weight, the amount of bleed out to the sheet surface is too large, so that the antistatic performance is low even if the antistatic agent component is increased.

  Among the ester products produced from the polyhydric alcohol and the aliphatic monocarboxylic acid, a compound containing two or more ester bonds is preferred from the viewpoint of heat resistance.

  The polyoxyalkylene glycol having a number average molecular weight of 500 to 5000 used in the present invention and blocked at one end is ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1, Dihydric alcohols such as 2-butylene glycol, trimethylene glycol, neopentyl glycol, diethylene glycol, 2-methyl-1,3-propylene glycol, octamethylene glycol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediol A polyoxyalkylene glycol mainly composed of a condensed product is sealed at least one end. From the viewpoint of the antistatic effect, a product obtained by condensing polyethylene glycol is preferable. Moreover, it is also possible to use a polyoxyalkylene glycol end-capped product comprising a plurality of types of dihydric alcohols.

  Further, in particular, one or both ends of an alkyl, acyl, allyl group having 1 to 20 carbon atoms, or those having a glycidyl group or a methacrylate group in a part of the alkyl, acyl, or allyl group, or a glycidyl group or a methacrylate group Is preferred. When a polyoxyalkylene glycol having a number average molecular weight of 500 to 5000 having a relatively low number average molecular weight that is not end-capped is blended with the polyester, the polyester is hydrolyzed to greatly reduce the degree of polymerization. In the present invention, it is preferable to use polyoxyalkylene glycol having both ends blocked.

The number average molecular weight of the polyoxyalkylene glycol having at least one end blocked needs to be 500 to 5,000. More preferred number average molecular weight is 800-3500,
A particularly preferred number average molecular weight is 800-2500. When the number average molecular weight is less than 500, the heat resistance is low, and it is not preferable because it volatilizes during film formation. On the other hand, when the number average molecular weight exceeds 5000, not only the dispersion diameter in the polyester becomes large and the transparency is lowered, but also the heat resistance of the molded product itself may be lowered.

  The content of (A) polyoxyalkylene glycol (polyether) having at least one end blocked with a number average molecular weight of 500 to 5000 is 0.2 to 3% by weight based on the polyester resin of the present invention. It is necessary to be. A more preferable content is 0.3 to 2.5% by weight, and a particularly preferable content is 0.5 to 2.0% by weight. When the content is less than 0.2% by weight, the antistatic performance cannot be obtained, which is not preferable. On the other hand, if the content exceeds 3% by weight, it is difficult to impart slipperiness even if the component imparting slippery is increased, which is not preferable.

The (B) lithium metal-containing compound in the present invention is not particularly limited, but CF ₃ SO ₃ Li, LiPF ₆ , LiClO ₄ , LiBF ₄ , CF ₃ CO ₂ Li, LiSCN, Li (CF ₃ SO ₂ ) ₂ N , Li (CF ₃ SO ₂ ) ₃ C, etc., and lithium such as CF ₃ SO ₃ Li, Li (CF ₃ SO ₂ ) ₂ N, Li (CF ₃ SO ₂ ) ₃ C, particularly from the viewpoint of antistatic performance Salts are preferred.

In addition, there is an organic sulfonic acid metal salt represented by the following formula: R (X) _n SO ₃ Li (where R: an alkyl group having 5 to 30 carbon atoms, X: an aromatic group, n: 0 to 1, Li : Represents lithium element), and there is an aromatic sulfonic acid lithium salt represented by R—X—SO ₃ Li and an aliphatic sulfonic acid lithium salt represented by R—SO ₃ Li. The number is preferably 5 to 30. When the carbon number is in the range of 5 to 30, the lithium sulfonate is excellent in dispersibility in the polyester, and good transparency and antistatic effect are exhibited.

Examples of the sulfonic acid metal salt forming R (X) _n SO ₃ Li include octylbenzenesulfonic acid, dodecylbenzenesulfonic acid, octadecylbenzenesulfonic acid, undecylsulfonic acid, dodecylsulfonic acid, octadecylsulfonic acid and the like. However, it is not limited to these. Also, two or more of these may be used in combination.

  Moreover, content of the lithium metal containing compound mentioned above is 0.2 to 3 weight% with respect to polyester, Preferably it is 0.3 to 2 weight%, Most preferably, it is 0.5 to 1.5 weight%. When the content is less than 0.2% by weight, the antistatic performance cannot be obtained, which is not preferable. On the other hand, if the content exceeds 3% by weight, it is difficult to impart slipperiness even if the component imparting slippery is increased, which is not preferable.

The sheet can be obtained by, for example, melt-extruding with a normal polyester resin extruder such as a single-screw extruder or a twin-screw vent extruder and cooling the molten resin with a cooling drum. The sheet is preferably cooled as quickly as possible to prevent a decrease in transparency due to crystallization. The crystallinity measured by the density method is 10% by weight or less (density 1.348 g / cm ³ or less), and the sheet haze is 5% or less. Is desirable.

As a film forming method, there are a method of sandwiching and cooling between metal rolls (touch roll method), an electrostatic application method, an air knife method and the like, but the touch roll method is preferred from the viewpoint of sheet glossiness and thickness uniformity. The addition method of the inorganic particle mix | blended with polyester and the ester product produced | generated from a polyhydric alcohol and aliphatic monocarboxylic acid can apply a well-known method, and there is no special restriction | limiting. For example, each component is blended in advance in a tumbler or blender, and the above mixture is supplied to the extruder, or the component added to the polyester is preliminarily pelletized as a master batch and supplied to the extruder. There is a method of adding at the time of polymerization.

  Also, when a multilayer sheet of two or more layers is formed, it can be produced by a known technique such as melt lamination, coextrusion, and dry lamination, but the coextrusion method is preferred from the viewpoint of sheet quality. (A) Although the ratio which a layer should occupy to the whole thickness of a sheet | seat is 1 to 50%, 3 to 20% is preferable from the point of economical efficiency and quality stability. When the proportion of the skin layer is less than 1%, it is difficult to uniformly form a skin layer containing inorganic particles and a high-concentration ester product of polyhydric alcohol and monocarboxylic acid. It becomes unstable. On the other hand, even if the layer (A) is larger than 50%, the slipperiness is not further improved, and the transparency of the sheet tends to decrease, which is not preferable.

  The product of the present invention maintains the excellent recyclability inherent to the A-PET sheet, and pulverizes the ears of the sheet generated during film formation, or the skeleton generated during punching, and again the raw material of the sheet Can be used. These recycled materials can be returned to both the skin layer and the core layer of the product of the present invention.

  The slipperiness and antiblocking properties of the sheet are related to the performance of the sheet surface part, and the multilayer contains a skin layer containing inorganic particles and ester products of polyol and monocarboxylic acid at a higher concentration than the core layer. A structure is desirable. The core layer can maintain the transparency and mechanical properties of the sheet because the amount of the inorganic particles, the ester product of polyhydric alcohol and monocarboxylic acid, and the antistatic imparting component is less than the skin layer.

  The product of the present invention can be used as a container or blister by thermoforming as in the case of conventional A-PET sheets. As the thermoforming method to be used, a vacuum forming method, a pressure forming method, a hot plate forming method, a plug assist forming method, a reverse draw forming method, an air slip forming method and the like, or a forming method combining them can be considered as usual methods. Can be used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to this. Each characteristic value was measured according to the following method.

(1) Average particle diameter The diameter (particle diameter) having an integrated volume fraction of 50% in an equivalent spherical distribution measured with a MULTISIZER apparatus manufactured by Coulter Electronics Limited was defined as the average particle diameter.

(2) Sheet haze The haze (cloudiness) of the sheet | seat was measured by the method according to JIS-K-7105 using Nippon Denshoku Co., Ltd. haze meter NDH-20D.
Sheet haze of 5% or less ○
5% to 10%
A thing larger than 10% ×
It was evaluated.

(3) Sliding property Using a friction measuring machine TR type manufactured by Toyo Seiki, the static friction coefficient (μs) and dynamic friction coefficient (μd) of the sheet were measured by a method according to ASTM-1894.
A static friction coefficient of less than 0.60 and a dynamic friction coefficient of less than 0.35
If either the static friction coefficient or the dynamic friction coefficient exceeds the above criteria △
Both static friction coefficient and dynamic friction coefficient exceed the above standards ×
It was evaluated.

(4) Antistatic property Electric resistance measuring instrument (Hiresta-UP MCP- manufactured by Mitsubishi Chemical Corporation)
HT450) was measured for 6 hours at 23 ° C. ± 2 ° C., 50% RH ± 5% RH and 15 ° C. ± 1 ° C., 30% RH ± 3% RH, and then measured. The measurement conditions were an applied voltage of 1000 V, a sampling time of 30 sec, 50 points on each side of a 10 cm × 10 cm sample sheet, and the average value was adopted. As a result, a surface resistance value of less than 10 ¹³ Ω / □ under both measurement conditions
10 ¹³ Ω / □ or more ×
It was evaluated.

(5) Impact strength of sheet Using a surface impact tester (Hydroshot), manufactured by Shimadzu Corporation, the crack initiation energy at 25 ° C under the conditions of a punching speed of 5 m / sec, a punching punch diameter of 13 mm, and a die diameter of 76 mm. It was measured.
Those with crack generation energy of 6KJ / m or more ○
Less than 6KJ / m ×
It was evaluated.

(6) Comprehensive evaluation: A case where all of the evaluation items (2) to (5) are satisfied and the film forming state is good is evaluated as ◯, and other cases are evaluated as ×.

Examples 1-13, Comparative Examples 1-18
Using various base PET resins listed in Table 1, inorganic particles shown in Table 2 at 270 ° C., ester products shown in Table 3, metal compounds shown in Table 4, and Table 5 using a biaxial kneader. Each 10% by weight master of a polyether compound (polyoxyalkylene glycol) was prepared. The resin used at the time of film formation and the base resin used for master chip preparation were made the same, and a laminate was prepared taking care not to change the resin composition due to the master formulation.

  When performing melt extrusion from a T die using an extruder with a biaxial vent under the conditions of 275 ° C. and a vacuum degree of 667 Pa in the vent part, and forming a film by the touch roll method, these inorganic particles and ester product, and Various antistatic agent masters were blended with the base PET resin in the proportions described in the examples, and sheets having the compositions shown in the examples were produced and evaluated.

  As shown in Tables 6 and 7, ester products of inorganic particles having a specific secondary particle system in polyester, a specific polyhydric alcohol and an aliphatic monocarboxylic acid, and end-capped polyethers having a specific number average molecular weight It can be seen that excellent slipperiness and antistatic performance can be achieved by blending a specific amount of the lithium metal-containing compound.

  However, as in Comparative Examples 9 and 12, when the amount of the ester product of the specific polyhydric alcohol and the aliphatic monocarboxylic acid or the lithium metal-containing compound is too large in the polyester, the slipperiness is good. It can be seen that antistatic performance cannot be imparted even when a specific amount of the end-capped polyether having a specific secondary particle size and a specific number-average molecular weight are added. On the other hand, when the amount of the end-capped polyether having a specific number average molecular weight and / or the lithium metal-containing compound is too large, the antistatic performance is good, but the inorganic particles having the secondary particle system and the specific many It can be seen that even if a predetermined amount of the ester product of a monohydric alcohol and an aliphatic monocarboxylic acid is blended, the slipperiness is poor.

  In addition, the combined use of the end-capped polyether with a specific number average molecular weight and a lithium metal compound can provide excellent antistatic performance even in a low-temperature and low-humidity atmosphere. In the case where is used, the antistatic performance is insufficient, and it can be seen that there is almost no effect particularly in a low temperature and low humidity atmosphere.

The influence of the polyoxyalkylene glycol having a number average molecular weight of 500 to 5,000 with at least one end blocked can be concluded as follows. The polyester sheets of Examples 1 to 12 satisfy the requirements described in claim 1 of the present invention, have excellent antistatic performance regardless of temperature and humidity, and have excellent transparency and good mechanical strength. Had. In contrast, when polyethylene glycol that is not end-capped as in Comparative Examples 13 and 14 is used, the intrinsic viscosity of the sheet is remarkably reduced and the physical properties of the sheet are also low, so that it is broken during winding and cannot be produced. It was. Moreover, when the number average molecular weight of polyether exceeded 5000 like the comparative example 16, haze exceeded 10% and it became opaque and the transparent polyester sheet was not obtained. Further, when the blending amount of the polyether having a number average molecular weight of 500 to 5000 is less than 0.1% by weight as in Comparative Example 17, the surface resistance value at low temperature and low humidity (15 ° C. × 30% RH). Was 10 ¹³ Ω / □ or more, and the antistatic performance was poor.

  The product of the present invention has both excellent antistatic performance and sliding performance without impairing the processing properties such as transparency, printability, and adhesiveness of the A-PET sheet. The sheet has excellent antistatic performance regardless of temperature and humidity, and excellent cutting properties, punching, bending, and assembly processing, making it an ideal material for clear cases. Moreover, it is also useful to use as a container or a blister without deteriorating the excellent antistatic performance and sliding performance even when processing such as thermoforming.

Claims (1)

  (A) Polyester having an intrinsic viscosity of 0.5 to 1.1, 0.01 to 1% by weight of inorganic particles having an average secondary particle diameter of 2 to 20 μm, and a polyvalent having three or more hydroxyl groups 0.1 to 2.0% by weight of an ester product of an alcohol and an aliphatic monocarboxylic acid having 12 or more carbon atoms and a polyoxyalkylene glycol having a number average molecular weight of 500 to 5000 and at least one end blocked 0.2 to 3% by weight, a layer containing 0.2 to 3% by weight of a lithium metal-containing compound, (B) a layer made of polyester having an intrinsic viscosity of 0.5 to 1.1, A) A polyester laminate in which the layer is laminated on at least one side, and the (A) layer is in the range of 1 to 50% of the total sheet thickness.