JP3355880B2 - Copolyester sheet and three-dimensional molded article comprising the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is excellent in deformation resistance to boiling water, heat and body deformation under heat, impact resistance, chemical resistance, heat stability, gas barrier property, ultraviolet shielding property, heat sealing property, recyclability and the like. The present invention relates to a transparent sheet made of a copolymerized polyester, which can provide a three-dimensional molded body with high productivity and is excellent in three-dimensional processability.

[0002]

2. Description of the Related Art Polyethylene terephthalate (hereinafter, referred to as "polyethylene terephthalate")
It is called "PET". ) Is excellent in mechanical strength, chemical stability, transparency, hygiene and the like, and is lightweight and inexpensive, so that it is widely used as a packaging material for various sheets and containers. Particularly in recent years, from the viewpoints of waste disposal problems and environmental protection, the use of polyvinyl chloride, polystyrene, and the like has been remarkably used in extrusion sheets, drawn containers, and the like.

[0003] In the case of a drawn container, for example, such a PET is generally manufactured by extruding a sheet with an extruder and then drawing. However, since a transparent drawn container formed by drawing a conventional PET sheet is used in an undrawn state or a low drawn state and without being subjected to crystallization treatment, it does not necessarily have sufficient wet heat resistance. It is difficult to say, especially when transported, such as during transportation, is kept under high temperature and high humidity, so that the sides and corners shrink, and flat parts such as sides and bottoms deform such as warpage and swelling. There is a problem that it is easy to occur.

On the other hand, as a processing method for improving the heat resistance of a drawn molded article, a method in which a sheet is once uniaxially stretched, heated to a predetermined temperature, contracted, and then subjected to thermal processing (Japanese Patent Laid-Open No. Sho 50-21051). Japanese Patent Application Laid-Open No. 57-53316), a method in which a sheet is biaxially stretched, heated in an inert gas and deep drawn, and then quenched to a secondary transition temperature or lower (Japanese Patent Laid-Open No. 57-53316). A method of axially stretching, heat-treating in a mold at a temperature of 70 ° C. lower than the crystallization temperature to a temperature lower than the crystallization temperature, and then cooling with a cooling mold (Japanese Patent Publication No. 27850 / US Pat. No. 4,388,356); Is biaxially stretched to 1
After reducing the shrinkage at 50 ° C. to 3% or less, 180 to 2
There has been proposed a method of pressure forming at 40 ° C. (Japanese Patent Application Laid-Open No. 58-67411). However, since a sheet stretching operation is required, the processing cost is higher than that of the conventional processing method, and the production is further increased. There is a problem that the performance is reduced. Further, the sheet is heated to a temperature equal to or higher than the low-temperature crystallization temperature so that the hanging length of the sheet is set to 5 to 50% of the diameter of the opening of the mold, and then molded using a mold at 70 ° C. or less (Japanese Patent Publication No. 6-49334). Has also been proposed. Although this method has higher productivity than the method requiring the above-described stretching operation, since the sheet is heated to a temperature lower than the low-temperature crystallization temperature, the PET forming the sheet is easily crystallized, and the continuous thermoforming for a long time is performed. In this case, there is a problem that the rate of occurrence of a molded article lacking in transparency becomes higher than in the conventional method.

Further, the above-mentioned processing method for improving the heat resistance of the drawn compact may not be applicable depending on the target shape, size and thickness of the drawn compact. , That is, the heat resistance of polyester itself is required to be improved. On the other hand, heat-resistant resins such as polycarbonate resins and polyarylate resins are known as resins having excellent resistance to wet heat deformation,
A method of blending or laminating these with PET or using them has been tried. However, coloring occurs at the time of molding, the haze value of the obtained molded body is increased, and the productivity is reduced as compared with the conventional method. There is a problem. Furthermore, since these heat-resistant resins are significantly different in structure from PET,
There is a problem in recycling as PET.

However, in the three-dimensional processing of a thick sheet (board) having a thickness exceeding 2 mm, it is difficult to quickly and uniformly heat the surface and the inside of the sheet, and the surface temperature of the sheet is inevitably required. It will be higher than above. Therefore, in the conventional PET board, the crystallization speed is too high, so that crystallization proceeds in a high-temperature portion of the sheet surface, and there is a problem that transparency becomes low (haze value becomes high). Therefore, conventionally, as a raw material for these boards, an acrylic resin or a polycarbonate resin, which is an amorphous and highly transparent resin, has been used. However, the acrylic resin has a problem of low impact resistance. Further, polycarbonate has high resistance to wet heat deformation and impact resistance, but has low chemical resistance and poor moldability. For example, there is a problem that a sheet needs to be dried during three-dimensional processing.

On the other hand, as a polyester board, an amorphous copolymerized PET in which a large amount of cyclohexane dimethanol is copolymerized with PET, for example, a transparent board made of Eastman Chemical's Kodar PETG6763 is known. However, there is a problem that substantially no improvement in the resistance to wet heat deformation is observed with respect to the PET board and the chemical resistance is reduced. Furthermore, copolymerized PE in which cyclohexanedimethanol is copolymerized in a large amount
Since T is amorphous, it is necessary to perform drying at the time of sheet forming at a lower temperature for a longer time than in the case of ordinary PET, and furthermore, since it is more easily thermally decomposed than PET, a color deterioration trouble occurs. There is a problem that it is easy.

On the other hand, a large number of copolymerized polyesters having properties similar to PET, for example, copolymerized polyesters using terephthalic acid and naphthalenedicarboxylic acid as dicarboxylic acid components and ethylene glycol and diethylene glycol as diol components are known. . However, three-dimensional processing of a specific copolyester, which is capable of providing a three-dimensional molded body having improved three-dimensional processing property as compared with a conventional PET sheet and improved resistance to wet heat deformation and transparency. A transparent sheet suitable for use was not specifically known.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the boiling water deformation resistance, wet heat deformation resistance, and transparency as compared with a conventional three-dimensional molded article using a PET sheet.
In addition, it is possible to provide a transparent three-dimensional molded body having excellent impact resistance, chemical resistance, thermal stability, gas barrier properties, ultraviolet shielding properties, heat sealing properties, recyclability, etc., and furthermore, has high transparency and a large thickness Provided is a copolymer polyester sheet which can provide a three-dimensional molded body and has improved three-dimensional workability compared to a conventional PET sheet, and a three-dimensional molded body obtained by three-dimensionally processing the same. Is to do.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, have found a specific copolymer polyester sheet, and have reached the present invention. That is, the gist of the present invention is that (1) naphthalenedicarboxylic acid as a dicarboxylic acid component and ethylene glycol as a diol component as main components, and (2) terephthalic acid as a copolymer component in an amount of 5 to 25 mol based on all dicarboxylic acid components. %,
(3) 0.1 to 5 mol% of diethylene glycol based on all diol components, and (4) 0 to 10 mol% of cyclohexanedimethanol based on all diol components.
(5) The total amount of the above copolymer components is 5 to 30 mol%,
(6) intrinsic viscosity 0.5 to 1.5 dl / g, (7) glass transition temperature (Tg) of 105 to 125 ° C, (8) elevated temperature crystallization temperature (Tc) of 165 to 205 ° C, (9) ) Thickness is 0.1 to 15 mm, (10) Haze value is 0 to 6%, (1)
1) A copolyester sheet having a haze value per 1 mm of a thickness of 0 to 6%, and a three-dimensional molded article comprising the same.

Hereinafter, the present invention will be described in detail. The copolymer polyester constituting the sheet of the present invention is a copolymer polyester containing naphthalenedicarboxylic acid and ethylene glycol as main components, and as a copolymer component, terephthalic acid is 5 to 25 mol% as a ratio to all dicarboxylic acids, Preferably 6-20 mol%, more preferably 7-1.
7 mol%, particularly preferably in the range of 8 to 15 mol%, and 0.1 to 5 mol%, preferably 0.1 to 5 mol%, of diethylene glycol as a ratio to the total diol component.
It is contained in the range of 5 to 4 mol%, more preferably 1 to 3.5 mol%, and cyclohexane dimethanol is 0 to 10 mol%, preferably 1 to 8 mol%, more preferably, as a ratio to the total diol component. It is contained in the range of 3 to 7 mol%.

When the copolymerized polyester constituting the sheet has a terephthalic acid copolymerization amount of less than 5 mol%, 3
When a three-dimensional molded article having a large thickness is produced by three-dimensional processing, a sufficient whitening suppressing effect is not recognized, and the compatibility with PET is significantly reduced to deteriorate the material recyclability, which is not preferable. If the terephthalic acid copolymerization amount exceeds 25 mol%, the three-dimensional molded body is not preferred because the deterioration in boiling water deformation resistance and chemical resistance becomes remarkable. On the other hand, if the copolymerization amount of diethylene glycol is more than 5 mol%, the three-dimensional molded body is not preferable because the resistance to deformation due to boiling water is remarkably reduced and the thermal decomposition when the sheet is melt-molded becomes remarkable. On the other hand, if the cyclohexanedimethanol copolymerization amount exceeds 10 mol%, the chemical resistance is remarkably reduced and the thermal stability is lowered, which is not preferable. The copolymerized polyester constituting the sheet of the present invention does not necessarily require that the cyclohexane dimethanol component be copolymerized, but if it is copolymerized within the above range, the impact resistance of the three-dimensional molded article is further improved. The effect is obtained.

Further, the sum of the amounts of the above-mentioned copolymerized components, that is, the ratio of terephthalic acid to all dicarboxylic acids and the ratio of diethylene glycol to all diol components,
The sum of the ratio of cyclohexanedimethanol to all diol components is 5 to 30 mol%, preferably 8 to 25 mol%.
Mol%, more preferably in the range of 10 to 20 mol%. When the total amount of the copolymer components is less than 5 mol%, substantially no improvement in wet heat deformation resistance and impact resistance is observed, or even if it is observed, an effect of improving one of the performances. Only allowed. Further, when the total amount of the copolymer components exceeds 30 mol%, the solvent resistance is remarkably reduced, and the impact resistance and thermal stability may be remarkably reduced. Absent.

With respect to naphthalenedicarboxylic acid, which is a main component of the copolymerized polyester constituting the sheet of the present invention, 2,6-, 2,7-, 1,4-, 1,5-, 1,2
Examples thereof include naphthalenedicarboxylic acids such as 8- and 2,3-, but any naphthalenedicarboxylic acid may be used, and further these naphthalenedicarboxylic acids may be used alone, Two or more kinds may be used in combination. Of these naphthalenedicarboxylic acids, preferably 2,6- and 2,7-
Naphthalenedicarboxylic acid, more preferably 2,
6-naphthalenedicarboxylic acid.

As for cyclohexanedimethanol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol,
Any cyclohexane dimethanol such as cyclohexane dimethanol and 1,4-cyclohexane dimethanol may be used, and furthermore, these cyclohexane dimethanols may be used alone or 2
It may be used in combination of more than one kind. Of these cyclohexane dimethanols, preferred is 1,4-cyclohexane dimethanol. Further, the ratio of the cis-form / trans-form may be any ratio, but is preferably 60/40 to 0/100, more preferably 50/40.
It is in the range of 50-20 / 80.

Furthermore, a small amount of components other than terephthalic acid, naphthalenedicarboxylic acid, ethylene glycol and diethylene glycol, and cyclohexanedimethanol are contained in the copolymerized polyester constituting the sheet of the present invention without departing from the constitutional requirements of the present invention. It may be polymerized. Among these copolymer components, as for the difunctional component, phthalic acid, isophthalic acid, 4,4′-diphenylsulfone dicarboxylic acid,
Aromatic dicarboxylic acids such as 4'-biphenyldicarboxylic acid; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid; aliphatic dicarboxylic acids having an aromatic ring such as 1,3-phenylenedioxydiacetic acid; Examples thereof include aliphatic dicarboxylic acids such as acid, adipic acid, sebacic acid, and diglycolic acid. Further, as the oxycarboxylic acid component, p-hydroxybenzoic acid, 4-
(2-hydroxyethoxy) benzoic acid, glycolic acid and the like can be mentioned. Further, as the diol component, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 2-butyl-2-ethyl-1,3- Aliphatic diols such as propane diol,
Alicyclic glycols such as 1,4-cyclohexanedimethanol, p-xylylene glycol, 2,2-bis (4- (2-hydroxyethoxy) phenyl) propane, 4,4′-bis (2-hydroxyethoxy) And (2) alkylene diols having an aromatic ring such as diphenyl sulfone. These bifunctional copolymer components are:
As long as the ratio of the constitutional repeating units containing these components to the total constitutional repeating units is usually 10 mol% or less, preferably 5 mol% or less, all the carboxylic acid components and all the hydroxy components of the copolymerized polyester are substantially equal. A quantity such as a quantity is used.

A small amount of a trifunctional or higher polyfunctional component may be copolymerized within a range not departing from the constitutional requirements of the present invention. As the trifunctional or higher polyfunctional component, known compounds generally used for PET may be used. For example, polyvalent carboxyl components such as trimellitic acid, trimesic acid, and pyromellitic acid, and trimethylolethane And polyhydric hydroxy components such as trimethylolpropane, glycerin and pentaerythritol, and glycidyl ether components of aromatic dihydroxy compounds such as bisphenol A diglycidyl ether and bisphenol S diglycidyl ether. These trifunctional or higher polyfunctional components need not be particularly used, but when used, they are used in a range where gelation does not substantially proceed, that is, in all monomer unit components constituting the copolymerized polyester. On the other hand, usually 1.0 mol% or less,
Preferably, it is in the range of 0.6 mol% or less. When the polyfunctional component is copolymerized in a small amount, the degree of drawdown (sagging) of the sheet when the sheet is three-dimensionally processed tends to be smaller.

A small amount of a monofunctional component may be copolymerized without departing from the constitutional requirements of the present invention. Examples of the monofunctional component include benzoic acid, t-butylbenzoic acid, benzoylbenzoic acid, stearic acid, benzyl alcohol, stearyl alcohol and the like. When using these monofunctional components, usually 0.005 to 0.005 to all components constituting the copolymerized polyester.
It is desirably 1.0 mol%, preferably in the range of 0.01 to 0.75 mol%. Since the monofunctional component is copolymerized, the thermal stability during sheet molding is improved, and the acetaldehyde content of the transparent sheet of the present invention can be further reduced.

As described above, the copolymer composition of the copolymerized polyester constituting the sheet of the present invention is substantially the same as the copolymerized composition of the copolymerized polyester as the raw material used for forming the sheet. The sheet of the present invention includes an antioxidant such as a hindered phenol-based compound, a phosphorus-based compound, a thioether-based compound, a coloring agent such as titanium dioxide, a nucleating agent such as talc, and a carbonic acid, without departing from the constituent requirements of the present invention. Lubricants such as calcium and silica, as well as additives such as mold release agents, flame retardants, heat stabilizers, hydrolysis stabilizers, antistatic agents, hard coat agents, ultraviolet absorbers, light stabilizers, and fluorescent brighteners It may be appropriately contained. These additives may be added as they are at the time of production of the sheet, or in the form of a master batch, or may be added at the time of production of the raw material copolyester. Further, these additives may be used for the surface treatment of the sheet by a method such as coating or lamination.

The intrinsic viscosity of the copolymerized polyester constituting the sheet of the present invention is 30 in a mixed solvent of phenol / 1,1,2,2-tetrachloroethane (weight ratio = 1/1).
0.5 to 1.5 dl / g, preferably 0.55 to 1.3 dl / g, more preferably 0.6 to 1.5 dl / g when measured at ° C.
To 1.1 dl / g, particularly preferably 0.65 to 1.0 d
1 / g. If the intrinsic viscosity is less than 0.5 dl / g, it cannot have practically sufficient strength,
In particular, drawing and blowing are not preferred because the thickness unevenness of the obtained molded article becomes large. Also, 1.5 dl /
When the weight exceeds g, the moldability during the three-dimensional processing is poor, and when the sheet is melt-molded and manufactured, the melt viscosity is too high and the shear heat generation in the molding machine becomes large, resulting in thermal decomposition. Is remarkable, which is not preferable.

The sheet of the present invention has a glass transition temperature (hereinafter, referred to as “Tg”) of 105 to 125 measured by a differential scanning calorimeter (hereinafter, referred to as “DSC”).
° C, preferably 108-122 ° C, particularly preferably 11 ° C.
The temperature is in the range of 0 to 120 ° C, and the crystallization temperature at elevated temperature (hereinafter referred to as “Tc”) is 165 to 205 ° C, preferably 170 to 200 ° C, and more preferably 175 to 195.
It is in the range of ° C.

If the Tg is lower than 105 ° C., the boiling water deformation resistance of the three-dimensional molded product is not substantially recognized, which is not preferable. On the other hand, if the Tg exceeds 125 ° C., it is not preferable because the moldability when three-dimensionally processing the sheet is deteriorated. On the other hand, when Tc is less than 165 ° C.,
The whitening suppression effect during the three-dimensional processing is not substantially recognized, and not only is it difficult to increase the cycle of the three-dimensional processing step, but also it is difficult to produce a thick transparent three-dimensional molded body. It is. Further, when Tc exceeds 205 ° C. and when no temperature-rise crystallization peak is observed, the decrease in the chemical resistance of the transparent three-dimensional molded article is remarkable because the amount of ethylene naphthalenedicarboxylate chain is too small. Is not preferred.

Further, the sheet of the present invention usually has a melting temperature (hereinafter, referred to as “Tm”) of 21 as measured by DSC.
It is desirably in the range of 0 to 260 ° C, preferably 215 to 257 ° C, and more preferably 220 to 255 ° C. When Tm is in this range, since there is a sufficient amount of ethylene naphthalene dicarboxylate chain, a decrease in chemical resistance of a three-dimensional molded product obtained by three-dimensional processing is not substantially recognized. More preferred. Furthermore, when the Tm of the transparent sheet is in this range, the copolymerized polyester itself, which is a raw material of the sheet of the present invention, also has the crystallinity required for the crystallization treatment and / or the solid-state polymerization treatment. A transparent sheet having a low content of acetaldehyde by subjecting the copolyester having a reduced content of acetaldehyde which causes an off-odor or an unpleasant odor particularly in food packaging applications to the transparent sheet of the present invention,
As a result, a three-dimensional molded body can be manufactured.

The above measurement of Tg, Tc and Tm was carried out using a feather stainless razor blade as little as possible with as little shearing as possible.
0 mg) in an aluminum pan,
C, a measurement operation is performed in a nitrogen atmosphere from room temperature to 300 ° C. at a rate of 20 ° C./min. Tg
Is determined from the specific heat change behavior due to the glass transition of the calorific curve, and specifically, is the temperature at the intersection of the tangent at the midpoint of the specific heat change due to the glass transition and the tangent at a point before the specific heat change. Tc is the temperature at which the amount of heat generated per unit time at the exothermic peak due to crystallization is maximum, and Tm
Is the temperature at which the endothermic amount per unit time at the endothermic peak due to crystal melting becomes maximum.

Next, the sheet of the present invention has an average thickness of 0.1 to 15 mm. The optimum thickness of the sheet used in the three-dimensional processing is the design of the three-dimensional molded body, that is, the size, thickness, shape, weight, mechanical properties of the three-dimensional molded body to be manufactured, and the degree of deformation in the three-dimensional processing. (For example, the drawing ratio in the drawing process). In general,
For example, as a raw sheet for a drawn molded article or a blow molded article used for a packaging material or the like, the thickness is usually 0.1 to
A transparent sheet in the range of 2 mm, preferably 0.15 to 1.5 mm, more preferably 0.2 to 1.2 mm is used. On the other hand, as a raw sheet for a three-dimensional molded body used for materials such as windows, sunroofs, interiors and exteriors, the thickness is usually 1 to 15 mm, preferably 1.5 to 15 mm.
A transparent sheet having a size of 12 mm, more preferably 2 to 10 mm is used. The sheet of the present invention has the same shape as the conventional PET transparent sheet except for the thickness.
When manufacturing a three-dimensional molded body, it has a feature that a thicker three-dimensional molded body can be manufactured with high transparency. Further, the sheet of the present invention has a feature that even if the sheet is thinner than the conventional PET transparent sheet, a three-dimensional molded body having higher wet heat deformation resistance than the case using the conventional PET transparent sheet can be manufactured. Therefore, when designing a three-dimensional molded body, it is not necessary to increase the thickness for the purpose of improving the resistance to wet heat deformation beyond the necessity of mechanical strength, so that weight reduction, resource saving, and cost reduction In addition, it is possible to reduce waste.

The sheet of the present invention is excellent in transparency and has a haze value measured in the thickness direction of the sheet (hereinafter referred to as “actually measured haze value”).
I may say. ) As 0 to 6%, preferably 0 to 6%
4%, more preferably 0 to 3%, particularly preferably 0 to
2%. Further, the transparency of the sheet of the present invention is 0 to 6% as a haze value obtained by converting an actually measured haze value into a haze value per 1 mm of the sheet thickness (hereinafter, may be referred to as “1 mm haze value”). Preferably 0-4%,
It is more preferably 0 to 3%, particularly preferably 0 to 2%. When the measured haze value and / or the 1 mm haze value exceeds 6%, the whitening improvement in the three-dimensional processing is not substantially recognized.

The above-mentioned sheet of the present invention can be produced by subjecting a PET sheet to sheet molding of a copolymerized polyester produced by melt polymerization or by subsequent solid phase polymerization according to a conventionally known method. it can. The composition of the raw material copolyester,
That is, the copolymerization component is substantially the same as the sheet of the present invention. In addition, the intrinsic viscosity generally tends to slightly decrease due to hydrolysis and thermal decomposition during sheet production, so that the intrinsic viscosity of the target sheet of the present invention is usually 0.01 to 0. A copolyester having an intrinsic viscosity of 0.055 dl / g is used as a raw material.

The thermal properties of the starting copolyester may be any as long as the sheet of the present invention can be obtained. In particular, the starting copolyester sample is melted and quenched by DSC and then re-cooled. When measured at elevated temperature, the glass transition temperature (hereinafter, referred to as “Tg ′”) is 105 to 130 ° C., preferably 110 to 125 ° C.
° C and the crystallization peak is absent, or even when there is a crystallization peak, the crystallization temperature (hereinafter referred to as “Tc ′”) is 170 to 225 ° C, preferably 180 to 220 ° C. Those in the range of ° C are particularly preferably used. It is more preferable that the copolymerized polyester has the above-mentioned thermal characteristics because the productivity of the transparent sheet of the present invention is high.

In the present invention, Tg 'and Tc' were measured using a feather stainless razor blade as little as possible with as little cutting as possible (a weight of 5.0 m).
g) was placed in an aluminum pan, and the sample prepared was heated from room temperature to 300 ° C. at a rate of 20 ° C./min in a nitrogen atmosphere by DSC, and then melted and held at 300 ° C. for 10 minutes. Thereafter, the sample is quickly taken out and immersed in liquid nitrogen at the same time, kept for 1 minute, and kept at room temperature for 30 minutes to 1 hour.
The sample is left for a time, returned to room temperature, and returned to the apparatus, and the temperature is again increased from room temperature to 300 ° C. at a rate of 20 ° C./min. Tg 'is determined from the specific heat change behavior due to the glass transition of the calorific value curve during the reheating process, and specifically, the intersection of the tangent at the midpoint of the specific heat change due to the glass transition and the tangent at a point before the specific heat change. Temperature. Also, T
c ′ is the temperature at which the calorific value per unit time is the largest in the exothermic peak due to crystallization in the reheating process.

Usually, the starting copolyester has a polymer skeleton such as a metal element such as manganese, cobalt, zinc, antimony, germanium or titanium derived from the catalyst used in the production thereof or a phosphorus element derived from a stabilizer. At least one element is included. The type and amount of these contained elements are not particularly limited as long as they do not exceed the constituent requirements of the present invention, but from the viewpoint of color tone, antimony and germanium are preferably used as the elements derived from the polycondensation catalyst, and more preferably. Is a copolyester using germanium.

The above-mentioned copolymerized polyester is produced by melt polymerization or subsequent solid-phase polymerization according to a conventionally known method for PET. As a melt polymerization method, for example, a method of directly performing an esterification reaction using a dicarboxylic acid and a diol, and then further raising the temperature and gradually reducing the pressure to carry out a polycondensation reaction, a so-called T
Examples of the method include a PA method and a method in which a transesterification reaction is performed using a diol and an ester derivative of a dicarboxylic acid, for example, dimethyl ester of a dicarboxylic acid, and then the obtained reaction product is further subjected to a polycondensation reaction, a so-called DMT method. The copolymerized polyester produced by these melt polymerization methods is usually subjected to a solid-state polymerization treatment in a state of transparent amorphous pellets or a state of crystallization treatment.

In the case where the copolymerized polyester is particularly subjected to solid-phase polymerization, the oligomer content and acetaldehyde content in the sheet of the present invention are low because the oligomer content and the acetaldehyde content are low. The content can be reduced, so that contamination of the sheet by the oligomer of the processing apparatus when the sheet is processed into three-dimensional shape can be reduced, and the acetaldehyde content of the three-dimensional molded body can be reduced. In particular, when a three-dimensional molded product using the sheet of the present invention is used as a packaging material that comes into direct contact with food,
The acetaldehyde content in the sheet is usually 0-50p
pm, preferably 0 to 30 ppm, more preferably 0
It is desirable that the content be in the range of ２０20 ppm so that the contents in the packaging material do not change in taste or smell.

Next, the method for producing the sheet of the present invention will be described in detail. The sheet of the present invention can be manufactured by a melt molding method conventionally used for forming a sheet of PET or polycarbonate. Extrusion molding, press molding, and the like are used as these melt molding methods. For example, when the transparent sheet of the present invention is manufactured by extrusion cast molding, usually, a raw material copolyester is supplied to a hopper of a single-screw or twin-screw extruder to which a T-die is connected via a gear pump, and is extruded. It can be manufactured by melting in a cylinder of a machine, extruding it from a T-die into a sheet, and cooling it by a casting roll.

In this case, the molding temperature, specifically, the temperature of each part of the cylinder of the extruder, the gear pump, and the T-die is usually 23.
The temperature is in the range of 0 to 300 ° C, preferably 240 to 290 ° C, and can be set lower than in the case of PET, so that the thermal degradation of the copolymerized polyester can be suppressed to a low level. The surface temperature of the casting roll may be generally controlled at 15 to 70 ° C, preferably 20 to 60 ° C.

The extruder used for extrusion casting may or may not have a vent port in the cylinder. Since the starting copolyester generally contains hundreds to thousands of ppm of water, when an extruder without a vent port is used, to prevent hydrolysis of the copolyester in the cylinder, The copolymerized polyester is dried and fed to a hopper after the water content is usually 100 ppm or less, preferably 50 ppm or less. If an extruder with a vent port is used, the pressure in the cylinder can be reduced and the copolyester can be dried in the cylinder, so that the raw copolyester can be supplied without drying, Volatile impurities such as acetaldehyde contained in the polyester can be reduced in the cylinder. The vent port is usually 0 to 7000 Pa, preferably 0 to 300 Pa.
It is used by connecting to a pressure reduction system of 0 Pa, more preferably 0 to 700 Pa. When a twin-screw extruder is used, the screw may be any of a meshing type, a non-meshing type, and an incomplete meshing type.

With respect to the T-die, the direction in which the melt is discharged from the lip may be horizontal or vertical. Further, an auxiliary device such as a filter or a sampling valve may be connected between the T-die and the extruder. As for the casting roll, it is desirable to have a contact device such as an electrostatic contact device or a touch roll. In the case of producing a transparent sheet having a thickness of more than 2 mm, a multi-stage cooling roll or the like is usually used.

The sheet of the present invention is finally obtained by cutting both ends of the sheet with a trimming cutter after passing through a casting roll, and then winding it into a roll or cutting it into a panel. In particular, in the case of a sheet having a thickness of 2 mm or more, it is difficult to wind the sheet into a roll, and it is difficult to provide a three-dimensional processing because the sheet has a strong curl even when wound. It is desirable to cut it into a panel shape and commercialize it as a cut plate. Furthermore, in the case of a cut plate, it is desirable to cover the surface with a protective sheet to form a product in order to prevent the surface from being rubbed and damaged.

Although the sheet of the present invention has a specific range of Tc as described above, this Tc is controlled not only by the intrinsic viscosity and Tc 'of the starting copolymerized polyester, but also by the shearing history during sheet molding. And the degree of generation of the crystal nucleus precursor. Tc tends to be lower in a sheet manufactured in a situation where the shear history is considered to be large or a degree of generation of the crystal nucleus precursor is considered to be high. The control during molding includes design of screw shape and rotation speed, die shape, filter and gear pump shapes, temperature setting and time setting, extrusion speed, take-up speed, casting roll temperature, depressurization degree of vent port, etc. This is done by adjustment. For example, in the same apparatus, the shearing history increases as the extrusion speed or the take-up speed increases, and the degree of generation of the crystal nucleus precursor increases as the casting roll temperature increases.

The sheet of the present invention obtained in this manner has wet-heat deformation resistance, transparency, impact resistance, chemical resistance, heat stability, gas barrier properties, ultraviolet shielding properties, heat sealing properties,
A three-dimensional molded body excellent in recyclability and the like can be provided with high productivity. More specifically, the three-dimensional processing of the sheet of the present invention makes it less likely to deform even when exposed to a high-temperature and high-humidity environment for a long period of time, compared to the case of using a conventional polyester transparent sheet. , A transparent three-dimensional molded body with improved properties can be produced. Further, since the sheet of the present invention suppresses whitening during three-dimensional processing as compared with a conventional polyester transparent sheet, a transparent three-dimensional molded body can be molded in a high cycle and has a large thickness. Even a three-dimensional molded body having excellent transparency can be easily manufactured.

The definition of three-dimensional molding or three-dimensional processing in the present invention is that a sheet which is originally a two-dimensional shape is thermally processed at a temperature lower than its melting temperature and has a three-dimensional shape which is stable at room temperature. Processing, specifically drawing,
Examples include bending, twisting, and blowing.

In the drawing of the sheet of the present invention, any method conventionally known as a drawing method of a polyester sheet may be used. Examples of the drawing method include vacuum forming, pressure forming, snapback forming, levers draw forming, air slip forming, plug assist forming, and a processing method combining these, and the like. Is also good. The processing temperature is usually 110 to 170 ° C, preferably 1 to 1, as the sheet temperature.
15 to 160 ° C., and the drawing ratio is usually 0.01 to 10
Times, preferably 0.05 to 5 times. Regarding the sheet temperature, the temperature may be different between the surface of the sheet and the inside of the sheet, but it is preferable that the processing is performed so that all the portions to be processed are within the above temperature range. Further, it is generally desirable that the sheet temperature be such that temperature unevenness in the thickness direction is reduced as much as possible. In particular, the transparent sheet of the present invention has larger temperature unevenness than conventional PEN sheets and PET sheets. Even if it is processed under the conditions, it has a feature that it can provide a drawn molded body with suppressed whitening and excellent transparency, so that the temperature of the preheating heater at the time of drawing is set high and the sheet heating time Can be shortened, and the productivity of the drawn molded article can be increased.

In bending or twisting, the sheet temperature is usually 110 to 170 ° C., preferably 115 to 160 ° C.
After the temperature is set to ° C., generally, a stress is applied to one or both surfaces to form a shape along the mold. Regarding the sheet temperature, the temperature may be different between the surface of the sheet and the inside of the sheet, but it is preferable that the processing is performed so that all the portions to be processed are within the above temperature range. Further, it is generally desirable that the sheet temperature be such that temperature unevenness in the thickness direction is reduced as much as possible. In particular, the sheet of the present invention has a condition in which the temperature unevenness is larger than that of a conventional PEN sheet or PET sheet. Even if it is processed in the sheet, it is possible to provide a bent molded product and a twisted molded product having excellent transparency with suppressed whitening. The time for raising the temperature can be shortened, and the productivity of these compacts can be increased. The stress applied at the time of processing is generally given directly from a mold, but may be given by means such as air pressure or vacuum, or a method combining these. Also,
The bending angle, the twist angle, and the radius of curvature at the time of processing are not particularly limited, and may be set according to the desired final shape.

In the blow processing, the sheet temperature is usually set at 110 to 170 ° C., preferably 115 to 160 ° C., and then blown into a predetermined mold to have a shape along the mold.
In this case, for example, the blowability can be improved by mechanically extending the sheet in a direction perpendicular to the sheet surface by a rod at the start of blowing. In addition, the mold is PET
By using a split movable mold as exemplified by a stretch blow mold for a bottle, it is possible to obtain a molded body whose opening is smaller than the cross section of the main body. Regarding the sheet temperature, the temperature may be different between the surface and the inside of the sheet,
It is desirable that the processing is performed so that all the parts to be processed are within the above temperature range. Further, it is generally desirable that the sheet temperature be such that temperature unevenness in the thickness direction is minimized as much as possible.
Even when processed under conditions where temperature unevenness is greater than that of EN sheets and PET sheets, preheating during processing is possible because of the characteristic that a blow molded article with suppressed whitening and excellent transparency can be provided. The temperature of the sheet heater can be shortened by setting the temperature of the heating heater high, and the productivity of the blow molded article can be increased. By blowing the sheet, it is possible to manufacture a large-size blow-molded body, which has conventionally had a very high production cost in the blow-molding of the injection-molded body, at a lower cost and with higher productivity.

The drawn molded article obtained by subjecting the sheet of the present invention to three-dimensional processing has high resistance to heat and heat deformation such as packaging materials, windows, sunroofs, interiors and exteriors exposed to high-temperature and high-humidity environments. It is suitable as a required transparent material. First, packaging materials, which are one of the uses of the sheet of the present invention, include, for example, food packaging trays and cups for side dishes, fruits, dumplings, tea bags and the like, and their lids, packaging of electronic components and the like. Industrial trays used, blister packages for toothbrushes, headphones, etc., and packaging cases for gifts, character goods, etc. can be mentioned. By using the transparent sheet of the present invention for these packaging materials, there is an advantage that the transparent sheet is less likely to be deformed even when it is held in a high-temperature, high-humidity environment during transportation or storage. Usually, these packaging materials are sheets of the present invention having a thickness of 0.1 to 2 mm,
It is made of a molded product obtained by three-dimensional processing such as drawing or blowing, and the thickness is generally 0.05 to 1.5 m.
m.

Next, as a transparent material such as a thick window, a sunroof, an interior, an exterior, etc. in which the sheet of the present invention is used, for example, a window or a door such as a bathroom, a shower room, a solarium, a light bulb or a broach type. Covers for lighting fixtures such as fluorescent lights, car windows and sunroofs,
Use transparent materials for daylighting, see-through, lighting, display, etc., such as windows for see-through of electric appliances such as automatic dishwashers and microwave ovens, road display devices, indoor parking lots and car washing places, and guide boards for gas stations. Can be mentioned. Other uses include cooking utensils such as bowls, kitchen trays, jelly cups, and other storage and transportation products such as cases and containers, bags, and the like. By using the sheet of the present invention for these thick transparent materials, there is an advantage that the sheet is hardly deformed even when repeatedly used for a long period of time in an environment of high temperature and high humidity. Normally, these transparent materials are formed from a transparent sheet of the present invention having a thickness of 1 to 15 mm and subjected to three-dimensional processing such as drawing, bending, twisting, and blow processing. And the thickness is generally 0.8 to 10 mm. Furthermore, the sheet of the present invention can be used as it is as a transparent material for daylighting, see-through, illumination, display, etc. without performing three-dimensional processing.

The copolymerized polyester used in the sheet of the present invention is compatible with PET at any ratio even if it is mixed in a molten state, so that the material can be easily recycled as PET, and the copolymer itself can be obtained by a methanolysis method or a glycolysis method. It is possible to apply the chemical recycling performed in PET represented by, for example, the same conditions. Therefore, the sheet of the present invention and the three-dimensional molded body using the same have high recyclability and also have an effect of suppressing the influence on the environment.

[0047]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples unless it exceeds the gist.

<Measurement Method and Calculation Method> The measurement method and calculation method used in this example are described below. The method for measuring the intrinsic viscosity is as described above. (1) Copolymerization component 10 mg of a polyester sample was deuterated with 2,2,2-trifluoroacetic acid / deuterated chloroform (volume ratio = 1/1).
The solution dissolved in 1 cc of the mixed solvent of 3) was subjected to proton NMR measurement at 23 ° C. using an AM500 type NMR device manufactured by Bruker to identify copolymer components and quantify the content.

(2) Measured Haze Value and 1 mm Haze Value The measured haze value was measured by cutting a 6 cm square test piece from a sheet and using a HGM-2DP type direct-reading haze computer manufactured by Suga Test Instruments Co., Ltd. The 1 mm haze value was calculated from the actually measured haze value and the thickness of the measurement site using the following equation.

[0050]

K = 100−100 × {(100−H) / 100} ^{1 / S In} this formula, K is a 1 mm haze value (unit:%), H is a measured haze value (unit:%), and S is It is the thickness (unit: mm) of the site where the measured haze of the sample was measured. (3) DSC measurement The measurement was carried out using a TA2000 type thermal analyzer manufactured by TA Instruments by the measurement method described above.

<Test Method> The test method used in this example is shown below. (1) Boiling Water Deformation Resistance Test The degree of deformation when the three-dimensional molded body was left in deionized water at 100 ° C. for 10 minutes was observed. As a result, "○" indicates that substantially no deformation was observed, and "X" indicates that deformation was observed.

(2) Impact Resistance Test Ten three-dimensional molded bodies were left as they were or filled with water at 4 ° C. for 24 hours.
Keeping the bottom of the container horizontal at a height of 1.5m or 3m in an environment with a temperature of 23 ° C and a relative humidity of 50% while keeping the temperature at 23 ° C, the surface is continuous on smooth and flat concrete. It was allowed to fall freely five times, and the number of cracks during that time was taken as an index of impact resistance. The smaller the number of cracks, the higher the impact resistance.

<Raw Material Polyester> The raw material polyester used in the sheet forming in this example is shown in Table 1.

[0054]

[Table 1]

Example 1 A raw material polyester C shown in Table 1 was used as a sheeting device as a gear pump, a filter,
TEX65 manufactured by Japan Steel Works, Ltd.
Set temperature 285 ° C, vent port pressure 1mmH using a 65mmφ same direction twin screw extruder (with vent port)
extruded under the following conditions and wound up through a casting roll (with a touch roll) with a surface temperature of 40 ° C.
A transparent sheet having a thickness of 600 μm was formed. Table 2 shows the physical property values of the transparent sheet.

Next, the transparent sheet was vertically oriented using a plug-assist type vacuum pressure molding machine manufactured by Asano Laboratories under the conditions of a sheet heating time of 5 seconds, a sheet surface temperature of 145 ° C., and a mold temperature of 40 ° C. It is a rectangle of 11 cm and a width of 14 cm, the upper end opening is a rectangle of 12.5 cm in length and 15.5 cm in width, and a truncated quadrangular pyramid shape having a height of 3 cm (aperture ratio = 0.24). Width 5 adjacent to the outside of the part
The sheet was drawn into a tray having a flat flange part of mm. The drawn product was excellent in transparency, well formed with each side and corner, had sufficient tactile strength, and was good in appearance. Table 2 shows the results of a boiling water deformation resistance test and an impact resistance test performed on the drawn molded body. The impact resistance test was carried out by bonding a transparent sheet before drawing to the flange portion of the drawn product, filling the inside with demineralized water, filling it, and then leaving it at 4 ° C. for 24 hours. It was carried out by free fall with the bottom face down from the height.

Examples 2 to 7 Using the copolymerized polyester shown in Table 2, a transparent sheet and a drawn molded article were formed in the same manner as in Example 1. However, in Example 4, the molding temperature at the time of molding the transparent sheet was 278 ° C. Table 1 shows the physical properties of these transparent sheets and the test results of the drawn compacts.
It is shown in FIG. The impact resistance test was performed under the same conditions as in Example 1. In addition, each of the obtained drawn compacts had firmly formed sides and corners, had sufficient tactile strength, and had good appearance.

Comparative Examples 1 to 7 Using the copolymerized polyester shown in Table 2, a transparent sheet and a drawn molded article were formed in the same manner as in Example 1. However, as for the molding temperature at the time of forming the transparent sheet, Comparative Example 1 and Comparative Example 2 were 295 ° C., Comparative Example 3 was 285 ° C., Comparative Example 4 was 270 ° C.
Comparative Examples 5 to 7 were set to 280 ° C. Table 2 shows the physical property values of these transparent sheets and the test results of the drawn molded articles. The impact resistance test was performed under the same conditions as in Example 1. In addition, whitening was observed in the drawn molded articles obtained in Comparative Examples 1 to 4, which were not preferable in appearance.

[0059]

[Table 2]

[Embodiment 8] In the sheet forming of the embodiment 1, the T die is used for forming a board having a large opening of a slit for forming a board.
After replacing the die, the cooling roll was changed to a double-sided cooling three-stage roll, and a transparent sheet having a thickness of 3 mm was formed in the same manner as in Example 1. At this time, the transparent sheet was obtained as a panel-shaped cut plate without winding. Table 3 shows the physical property values of the transparent sheet.

Then, using the transparent sheet, a sheet heating time of 30 seconds, a sheet surface temperature of 140 ° C., and a mold temperature of 30 ° C.
Drawing was performed in the same manner as in Example 1 under the condition of ° C. to obtain a drawn molded body. The drawn product was excellent in transparency, well formed with each side and corner, had sufficient tactile strength, and was good in appearance. Table 3 shows the results obtained by performing a boiling water deformation resistance test and an impact resistance test on the drawn compact. In addition, the impact resistance test was performed by leaving the obtained drawn compact as it was at 4 ° C. for 24 hours and then freely dropping it from a height of 3 m.

Examples 9 to 13 Using the copolymerized polyesters shown in Table 3, the same procedures as in Example 8 were carried out.
A transparent sheet and a drawn molded article having the thicknesses shown in Table 1 were formed.
Table 3 shows the physical property values of these transparent sheets and the test results of the drawn molded articles. The impact resistance test was performed under the same conditions as in Example 8. In addition, each of the obtained drawn compacts had firmly formed sides and corners, had sufficient tactile strength, and had good appearance.

[Comparative Examples 8 to 14] Using the copolymerized polyester shown in Table 3, the same procedure as in Example 8 was carried out.
A transparent sheet and a drawn molded article having the thicknesses shown in Table 1 were formed.
However, as for the molding temperature at the time of molding the transparent sheet, Comparative Example 8 and Comparative Example 9 were 295 ° C., and Comparative Example 10 was 285 ° C.
° C, Comparative Example 11 is 270 ° C, Comparative Examples 12 to 14 are 280 ° C.
° C. Table 3 shows the physical property values of these transparent sheets and the test results of the drawn molded articles. In the drawing of the sheet having a thickness of 6 mm obtained in Comparative Example 8, crystallization was excessively progressed during heating of the sheet, so that the drawing could not be performed well. In addition, whitening was observed in all of the drawn molded articles obtained in Comparative Examples 8 to 11, which were not preferable in appearance.

[0064]

[Table 3]

Example 14 The transparent sheet having a thickness of 3.0 mm produced in Example 10 was cut into a rectangle having a length of 7 cm and a width of 20 cm, and was preheated for 20 seconds to reduce the sheet surface temperature to 130 ° C. After that, a bending process is performed along the sheet surface centering on a position 10 cm from the end, and a bending angle of 9 cm.
An L-shaped bent body having a temperature of 0 ° C and a radius of curvature of 2 cm was obtained. The bent product was excellent in transparency, had sufficient tactile strength, and was good in appearance. In addition, a boiling water deformation resistance test was performed on the bent product, but no deformation was observed.

Example 15 An L-shaped bent body was obtained in the same manner as in Example 14, except that the transparent sheet having a thickness of 6.0 mm produced in Example 12 was used. The bent product was excellent in transparency, had sufficient tactile strength, and was good in appearance. In addition, a boiling water deformation resistance test was performed on the bent product, but no deformation was observed.

Comparative Example 15 An L-shaped bent body was obtained in the same manner as in Example 14, except that the transparent sheet having a thickness of 3.0 mm produced in Comparative Example 13 was used. The bent product was excellent in transparency, had sufficient tactile strength, and was good in appearance, but the bent product was remarkably deformed in a boiling water deformation resistance test.

Comparative Example 16 An L-shaped bent body was obtained in the same manner as in Example 14, except that the transparent sheet having a thickness of 3.0 mm produced in Comparative Example 14 was used. The bent product was excellent in transparency, had sufficient tactile strength, and was good in appearance, but the bent product was remarkably deformed in a boiling water deformation resistance test.

[0069]

According to the present invention, the copolyester sheet of the present invention is difficult to realize with the conventional polyester sheet due to its three-dimensional processing such as drawing, bending, twisting, and blowing. A three-dimensional molded body having high boiling water deformation resistance, high transparency, and a large thickness,
It can be provided with good productivity. For example, by subjecting the transparent sheet of the present invention to three-dimensional processing, it is possible to produce a transparent three-dimensional molded body having boiling water deformation resistance that does not substantially deform even when used under boiling water. Since the whitening during the three-dimensional processing is suppressed in the three-dimensional molded body obtained from the sheet of the present invention, a transparent three-dimensional molded body can be molded in a high cycle. It has improved wet heat deformation resistance and transparency, and has excellent impact resistance, chemical resistance, heat stability, gas barrier properties, ultraviolet shielding properties, heat sealing properties, etc.
Packaging materials, windows, sunroofs, interiors, exteriors, cooking utensils, storage utensils exposed to high temperature and high humidity environments,
It is preferably used as a transparent material that requires high resistance to moisture and heat deformation, such as transport articles. In addition, the sheet of the present invention,
It can also be used as it is as a transparent material for daylighting, see-through, illumination, display, etc. without performing three-dimensional processing. Since the copolymerized polyester used for the transparent sheet of the present invention has high recyclability, the sheet of the present invention and the three-dimensional molded article using the same also have an effect of minimizing the effect on the environment.

(56) References JP-A-5-255492 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 63/00-63/91 C08J 5/18

Claims (6)

(57) [Claims] (1) Naphthalenedicarboxylic acid as a dicarboxylic acid component, ethylene glycol as a diol component, and (2) terephthalic acid as a copolymer component in an amount of 5 to 25 mol% based on all dicarboxylic acid components. 3)
Diethylene glycol was added in an amount of 0.1
-5 mol%, (4) cyclohexanedimethanol is contained in an amount of 0-10 mol% based on all diol components, (5) the total amount of the above-mentioned copolymer components is 5-30 mol%, and (6) the intrinsic viscosity is 0. 0.5 to 1.5 dl / g, (7) glass transition temperature (T
g) is in the range of 105 to 125 ° C .;
c) is 165 to 205 ° C, (9) the thickness is 0.1 to 15 m
m, (10) haze value is 0-6%, (11) thickness 1 mm
A sheet made of a copolymerized polyester, which has a haze value of 0 to 6%. 2. (1) Naphthalenedicarboxylic acid as a dicarboxylic acid component, ethylene glycol as a diol component, and (2) terephthalic acid as a copolymer component in an amount of 5 to 25 mol% based on all dicarboxylic acid components.
(3) 0.1 to 5 mol% of diethylene glycol based on all diol components, and (4) 0 to 10 mol% of cyclohexanedimethanol based on all diol components.
(5) The total amount of the above copolymer components is 5 to 30 mol%,
(6) Intrinsic viscosity is 0.5 to 1.5 dl / g, (7) Glass transition temperature (Tg ') after melt quenching treatment is 105 to 13
0 ° C., (8) elevated crystallization temperature (T
The sheet according to claim 1, wherein the copolyester having c ') at 170 to 225 ° C or having no crystallization peak is obtained by melt extrusion molding. 3. The sheet according to claim 1, wherein the melting temperature of the sheet is from 210 to 260 ° C. 4. A three-dimensional formed body obtained by drawing the sheet according to claim 1. 5. A three-dimensional formed body obtained by bending and / or twisting the sheet according to claim 1. 6. A three-dimensional formed body obtained by blowing the sheet according to claim 1. Description: