JP2006233091A - Polyester-based resin composition, polyester-based thermally shrinkable film, thermally shrinkable label, and container having the label attached thereto - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition suitably used for polyester-based thermally shrinkable films which exhibit good shrinkage characteristics, give good shrinkage finishes, when shrunk, and hardly deteriorate stretchability with the passage of time, to provide a film, to provide a label, and to provide a container. <P>SOLUTION: This polyester-based resin composition comprises the following polyester-based resin (A), the following polyester-based resin (B) and the following polyester-based resin (C) in prescribed amounts, respectively. (A) The polyester-based resin comprising a dicarboxylic acid residue component containing a prescribed amount of an alicyclic dicarboxylic acid residue, and a diol resin component consisting mainly of ethylene glycol residue. (B) The polyester-based resin comprising a dicarboxylic acid residue component consisting mainly of an aromatic dicarboxylic acid residue and a diol residue component consisting mainly of a prescribed aliphatic diol residue. (C) The polyester-based resin comprising a dicarboxylic acid residue component consisting mainly of an aromatic dicarboxylic acid residue and a diol residue component consisting mainly of a prescribed amount of an alicyclic diol residue. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polyester-based resin composition, a polyester-based heat-shrinkable film composed of the composition, a heat-shrinkable label, and a container provided with the label. More specifically, the present invention, when a heat-shrinkable film is formed, does not cause defects such as shrinkage spots, wrinkles, distortion, etc. after heat-shrink processing, and is a polypropylene bottle that is difficult to label at high temperatures or PET with poor heat resistance For containers such as bottles, the shrink finish is good, and after heat shrink processing, it can be easily cut and peeled along the perforations formed in the film, and the elongation at break in the direction perpendicular to the main shrink direction In the manufacturing process of heat-shrinkable film, the strength in the flow direction can be increased, so there is almost no breakage trouble in the manufacturing process of heat-shrinkable film, and it is suitable for heat-shrinkable films and labels that can be processed at high speed. Polyester-based resin composition, polyester-based heat-shrinkable film composed of the composition, heat-shrinkable label, and container equipped with the label On.

  Conventionally, stretched films made of polyvinyl chloride or polystyrene have been mainly used as heat-shrinkable labels used for glass bottles and polyethylene terephthalate bottles (PET bottles) and heat-shrinkable films for food packaging. On the other hand, in recent years, a heat-shrinkable film using a polyester resin excellent in safety and hygiene and chemical resistance has been demanded, and the use of a stretched film made of a polyester resin is increasing.

  However, the shrinkage rate of polyester-based heat-shrinkable films that are currently used increases rapidly as the temperature rises. Therefore, when coated on PET bottles, wrinkles, etc. occur in the film, resulting in shrinkage finish defects. There was a problem such as.

  For PET bottle labeling and the like, for which demand is expected to increase in recent years, a polyester-based heat-shrinkable film capable of obtaining a highly shrink-finished appearance at a relatively short time and at a relatively low temperature is desired.

  Further, in recent years, with the recycling of PET bottles, perforation is applied to heat-shrinkable labels, and good cut perforation is one of the important physical properties of heat-shrinkable labels. . However, currently used polyester heat-shrinkable films have problems such as poor perforation.

  In addition, the film easily breaks in the direction perpendicular to the main shrinkage direction during film formation (the flow direction in the heat shrinkable film manufacturing / processing process), and the film breaks in the printing process, the tubing process, the labeling process, etc. was there. Furthermore, when the container etc. which carried out the film | membrane shrinking | contraction of the film received the impact etc. from the outside, there existed problems, such as a film fracture | rupture.

  The breaking phenomenon tends to become more prominent as the elapsed time and the storage time after film production become longer, particularly as the storage environment temperature becomes higher. In recent years, from the viewpoint of economy, there is an increasing demand for thinning and high-speed processing of heat-shrinkable films, and the improvement in rupture resistance to make the above-mentioned breakage difficult is important in polyester-based heat-shrinkable films. It has become a challenge.

  For the above various problems, by blending 5% by mass to 10% by mass of an aromatic polycarbonate resin with a polyethylene terephthalate polymer having a glass transition temperature (Tg) of 40 ° C. or higher and 80 ° C. or lower, The glass transition temperature (Tg) is 20 with respect to 100 parts by mass of a method of slowing thermal shrinkage and widening the range of the shrinkage temperature (see, for example, Patent Document 1) or polyester resin having a glass transition temperature (Tg) of 40 ° C. or higher. There has been proposed a method of mixing 1 part by mass or more and 50 parts by mass or less of resins different in at least 0 ° C. (see, for example, Patent Document 2). Further, the polyester resin is about 50% by weight or more and about 99% by weight or less, and is essentially a linear random aliphatic-aromatic copolyester or branched and / or chain extended copolyester of about 1% by weight to about 50% by weight. A method using the following has been proposed (for example, see Patent Document 3).

  Further, in order to prevent appearance failure without a preheating step, a method of molding a composition comprising a polybutylene terephthalate copolymer and a polyethylene terephthalate copolymer obtained by copolymerizing a specific modified species (see, for example, Patent Document 4), In order to obtain good shrinkage in the high temperature shrinking process, a method of blending and molding a polybutylene terephthalate modified product and a polyethylene terephthalate modified product (see, for example, Patent Document 5) has also been proposed.

  In addition, the number of specimens having a breaking elongation of 5% or less when stored in an environment of 30 ° C. and 85% relative humidity for 2 weeks and performing a tensile test under specific conditions is 10% or less of the total number of specimens. There has been proposed a polyester heat-shrinkable film excellent in fracture resistance in a direction orthogonal to the main shrinkage direction of the film (see, for example, Patent Document 6).

Japanese Patent Laid-Open No. 5-25294 JP-A-4-50238 Special table 2004-536192 gazette JP 2001-151908 A JP 2002-212405 A JP 2003-41028 A

  However, the heat-shrinkable films described in Patent Documents 1 to 3 have a problem that the shrinkage finish is still insufficient and the cutness of the perforated label is inferior. Moreover, the heat-shrinkable film described in Patent Document 4 or Patent Document 5 has a problem that the shrink finish is still insufficient and the brittleness after stretching is inferior. Furthermore, the film described in Patent Document 6 is merely that the rate at which a test piece having a very small breaking elongation is generated after a storage test is suppressed, and the breaking elongation of a test piece having a breaking elongation of 5% or more is suppressed. No mention is made of the size of, and it cannot necessarily be said that the tear resistance is excellent. Therefore, the film described in Patent Document 6 is not sufficiently capable of solving the problem of deterioration over time in brittleness such as film breakage in various situations.

  The present invention has been made in order to solve the above-described problems of the prior art, and the object of the present invention is that when formed into a heat-shrinkable film, the film has a good shrinkage finish, and the brittleness deterioration with time. Polyester resin composition that can be easily cut and peeled along the perforations formed in the film, and a polyester heat-shrinkable film composed of the composition, heat-shrinkable It is to provide a label and a container equipped with the label.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a polyester-based resin (A) containing a predetermined amount of an alicyclic dicarboxylic acid component and a polyester system containing a predetermined amount of an alicyclic diol. By using the resin (C) in combination with the polyester-based resin (B) containing an aliphatic diol, it was found that the obtained heat-shrinkable film can solve the above problems, and the present invention has been completed.

  That is, the object of the present invention is achieved by the following polyester resin composition, polyester heat-shrinkable film, heat-shrinkable label, and a container equipped with the label.

The polyester resin (A), the polyester resin (B), and the polyester resin (C) below are 20 parts by mass or more and 600 parts by mass of the polyester resin (B) to 100 parts by mass of the polyester resin (A). A polyester resin composition comprising 80 parts by mass or more and 1700 parts by mass or less of a polyester resin (C) in an amount of not more than part by mass.
(A) a dicarboxylic acid residue component containing an alicyclic dicarboxylic acid residue and a diol residue component mainly composed of an ethylene glycol residue, wherein the alicyclic dicarboxylic acid residue A polyester resin containing 5 mol% or more and 50 mol% or less of the base component.
(B) A polyester resin comprising a dicarboxylic acid residue component having an aromatic dicarboxylic acid residue as a main component and a diol residue component having an aliphatic diol residue having 2 to 12 carbon atoms as a main component.
(C) a dicarboxylic acid residue component mainly comprising an aromatic dicarboxylic acid residue and a diol residue component containing an alicyclic diol residue, wherein the alicyclic diol residue is all diol residues. A polyester resin containing 10 mol% or more and 40 mol% or less in the component.

(2) The polyester-type resin composition as described in (1) whose glass transition temperature of the said polyester-type resin (A) is 60 degreeC or more and 80 degrees C or less.
(3) The polyester resin composition according to (1) or (2), wherein the alicyclic dicarboxylic acid residue is a 1,4-cyclohexanedicarboxylic acid residue.

(4) The polyester resin composition according to any one of (1) to (3), wherein the aliphatic diol residue is a 1,4-butanediol residue.
(5) The polyester resin composition according to any one of (1) to (4), wherein the polyester resin (B) further contains a polyether residue component.

(6) The polyester resin composition according to any one of (1) to (5), wherein the alicyclic diol residue is a 1,4-cyclohexanedimethanol residue.
(7) Heat in the main shrinkage direction when the polyester-based resin composition according to any one of (1) to (6) is formed, and is stretched at least in a uniaxial direction and immersed in warm water at 80 ° C. for 10 seconds. A polyester heat-shrinkable film having a shrinkage rate of 40% or more.
(8) The difference between the heat shrinkage rate in the main shrinkage direction when immersed in warm water at 80 ° C. for 10 seconds and the heat shrinkage rate in the main shrinkage direction when immersed in warm water at 70 ° C. for 10 seconds is 25% or less. The polyester heat-shrinkable film according to (7).

(9) A polyester heat-shrinkable multilayer film having at least one layer of the polyester heat-shrinkable film according to (7) or (8).
(10) A heat-shrinkable label using the polyester-based heat-shrinkable film according to (7) or (8) or the polyester-based heat-shrinkable multilayer film according to (9).
(11) A container equipped with the heat-shrinkable label according to (10).

  Since the polyester resin composition of the present invention contains at least three kinds of predetermined polyester resins, when formed into a heat-shrinkable film, good physical properties can be imparted to the film. Therefore, according to the present invention, the shrink finish is good, the brittle deterioration with time is small, and the film can be easily cut and peeled along the perforations formed in the film. In addition, according to the present invention, it is possible to provide a polyester heat-shrinkable label that has good shrinkage characteristics, little brittle deterioration with time, and excellent perforation, and a container with the label. .

  Hereinafter, the polyester resin composition of the present invention (hereinafter also referred to as “the composition of the present invention”), a polyester heat shrinkable film comprising the composition (hereinafter also referred to as “the film of the present invention”), and a heat shrinkable label. (Hereinafter also referred to as “label of the present invention”) and a container equipped with the label (hereinafter also referred to as “container of the present invention”) will be described.

[Polyester resin composition]
The composition of the present invention comprises the following polyester resin (A), polyester resin (B), and polyester resin (C) with respect to 100 parts by mass of the polyester resin (A). 20 parts by mass or more and 600 parts by mass or less, and the polyester resin (C) is contained by 80 parts by mass or more and 1700 parts by mass or less.
(A) a dicarboxylic acid residue component containing an alicyclic dicarboxylic acid residue and a diol residue component mainly composed of an ethylene glycol residue, wherein the alicyclic dicarboxylic acid residue A polyester resin containing 5 mol% or more and 50 mol% or less of the base component.
(B) A polyester resin comprising a dicarboxylic acid residue component having an aromatic dicarboxylic acid residue as a main component and a diol residue component having an aliphatic diol residue having 2 to 12 carbon atoms as a main component.
(C) a dicarboxylic acid residue component mainly comprising an aromatic dicarboxylic acid residue and a diol residue component containing an alicyclic diol residue, wherein the alicyclic diol residue is all diol residues. A polyester resin containing 10 mol% or more and 40 mol% or less in the component.

  In the present specification, the “main component” refers to a component having a content ratio of 50 mol% or more. Specifically, the “based on ethylene glycol residue” in the polyester-based resin (A) means that the content ratio of ethylene glycol residue is 50 when all diol residue components are 100 mol%. It means that it is at least mol%. Furthermore, “the main component is an aromatic dicarboxylic acid residue” in the polyester-based resin (B) means that the content ratio of the aromatic dicarboxylic acid residue when the total dicarboxylic acid residue component is 100 mol%. Is 50 mol% or more. In addition, “the main component of the aliphatic diol residue having 2 to 12 carbon atoms” in the polyester-based resin (B) means that 2 to 12 carbon atoms when the total diol residue component is 100 mol%. The content ratio of the aliphatic diol residue is 50 mol% or more. Furthermore, in the polyester-based resin (C), “having an aromatic dicarboxylic acid residue as a main component” means containing an aromatic dicarboxylic acid residue when the total dicarboxylic acid residue component is 100 mol%. It means that the ratio is 50 mol% or more.

<Polyester resin (A)>
The polyester resin (A) is composed of a dicarboxylic acid residue component containing an alicyclic dicarboxylic acid residue and a diol residue component mainly composed of an ethylene glycol residue.

  The alicyclic dicarboxylic acid residue contained in the dicarboxylic acid residue component of the polyester resin (A) is not particularly limited. For example, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4 -Residues derived from cyclohexanedicarboxylic acid or their ester derivatives. Cyclohexanedicarboxylic acid has a cis configuration and a trans configuration, but may have any configuration from cis isomer 100% to trans isomer 100%, and all combinations of cis isomer and trans isomer are possible. included. Among these, from the viewpoint of heat shrinkability and heat resistance, 1,4-cyclohexanedicarboxylic acid or an ester derivative thereof having a trans isomer of 20% to 100% is preferable.

  Moreover, it is preferable that dicarboxylic acid residue components other than the alicyclic dicarboxylic acid residue contained in the dicarboxylic acid residue component of the polyester resin (A) are aromatic dicarboxylic acid residues. Examples of the aromatic dicarboxylic acid residue include terephthalic acid, isophthalic acid, orthophthalic acid, phenylenedioxydiacetic acid, 4,4′-diphenyldicarboxylic acid, 4,4′-diphenoxyethanedicarboxylic acid, and 4,4. Examples include residues derived from '-diphenyl ether dicarboxylic acid, 4,4'-diphenylsulfone dicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, or ester derivatives thereof. Among these, a terephthalic acid residue or an ester derivative residue thereof is particularly preferable.

  The alicyclic dicarboxylic acid residue is an alicyclic ring that can induce an alicyclic dicarboxylic acid residue in the dicarboxylic acid compound when the dicarboxylic acid compound and the diol compound are reacted to obtain the polyester resin (A). By mixing the formula dicarboxylic acid compound, it can be contained as a single copolymer component.

  The content of the alicyclic dicarboxylic acid residue is 5 mol% or more in the total dicarboxylic acid residue component (100 mol%), and the upper limit is 50 mol%, preferably 40 mol%, more preferably 25 mol. %. If the upper limit of the content rate of an alicyclic dicarboxylic acid residue is 50 mol%, the haze and heat resistance of the polyester-type heat-shrinkable film obtained can be made compatible. If the lower limit of the content of the alicyclic dicarboxylic acid residue is 5 mol%, good shrinkage characteristics of the resulting heat-shrinkable film can be obtained.

  Furthermore, the polyester-based resin (A) may be obtained by copolymerizing a dicarboxylic acid residue other than the dicarboxylic acid residue component as long as the effects of the present invention are not impaired. Examples of such dicarboxylic acid residues include aliphatic dicarboxylic acids such as malonic acid, succinic acid, adipic acid, azelaic acid, and sebacic acid, or ester derivatives thereof, trimellitic acid, trimesic acid, pyromellitic acid, and the like. Examples thereof include a residue derived from a trifunctional or higher polyfunctional carboxylic acid or an ester derivative thereof.

  The diol residue contained in the diol residue component of the polyester resin (A) is preferably an ethylene glycol residue as a main component from the viewpoint of shrinkage finish. The content of ethylene glycol residues is 50 mol% or more, preferably 60 mol% or more, and more preferably 70 mol% or more in all diol residue components (100 mol%). If the content of the ethylene glycol residue is 50 mol% or more, a good shrinkage finish can be maintained.

  Furthermore, the diol residue component of the polyester resin (A) is, for example, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,5-pentane. Diol, 1,6-hexanediol, 1,10-decanediol, 2,2-dimethyl-1,3-propanediol, diethylene glycol, 1,1-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, 1,3 -Various diol residue components derived from cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,2-cyclohexanediol, 1,4-cyclohexanediol and the like may be copolymerized. It is preferable to copolymerize a butanediol residue or a 1,4-butanediol residue.

  The polyester resin (A) may be, for example, 4,4′-dihydroxybiphenyl, 2,2-bis (4′-hydroxyphenyl) propane, 2,2-, as long as the effects of the present invention are not impaired. Aromatic diols such as bis (4′-β-hydroxyethoxyphenyl) propane, bis (4-hydroxyphenyl) sulfone, bis (4-β-hydroxyethoxyphenyl) sulfone, glycolic acid, p-hydroxybenzoic acid, p- Monofunctional residue components derived from hydroxycarboxylic acids such as β-hydroxyethoxybenzoic acid, alkoxycarboxylic acids, stearic acid, stearyl alcohol, benzyl alcohol, benzoic acid, t-butylbenzoic acid, benzoylbenzoic acid, and the like, tricarbaryl Acid, hexanetricarboxylic acid, trimellitic acid, trimesic acid, pyro Derived from lithic acid, benzophenone tetracarboxylic acid, naphthalene tetracarboxylic acid, 1,2,6-hexanetriol, gallic acid, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, sorbitol, dipentaerythritol, polyglycerol, etc. It is also possible to copolymerize trifunctional or higher polyfunctional residue components.

  The polyester-based resin (A) preferably has a glass transition temperature of 60 ° C. or higher as measured with a differential scanning calorimeter (DSC) from the viewpoint of imparting heat resistance to the heat-shrinkable film obtained. On the other hand, the upper limit is not particularly limited, but is preferably 80 ° C. or less from the viewpoint of ease of molding. The glass transition temperature (Tg) of the polyester-based resin (A) is obtained by melting the polyester-based resin (A) at 280 ° C. for 5 minutes, then immersing it in liquid nitrogen and quenching it, and using it as a sample, It can be measured using DSC at a temperature rising rate of 20 ° C./min.

<Polyester resin (B)>
The polyester resin (B) comprises a dicarboxylic acid residue component mainly composed of an aromatic dicarboxylic acid residue and a diol residue component mainly composed of an aliphatic diol residue having 2 to 12 carbon atoms. . Examples of the aromatic dicarboxylic acid residue include terephthalic acid, isophthalic acid, orthophthalic acid, phenylenedioxydiacetic acid, 4,4′-diphenyldicarboxylic acid, 4,4′-diphenoxyethanedicarboxylic acid, and 4,4. Examples include residues derived from '-diphenyl ether dicarboxylic acid, 4,4'-diphenylsulfone dicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and ester derivatives thereof. An acid residue, a terephthalic acid residue or an ester derivative residue thereof is preferable, and a terephthalic acid residue or an ester derivative residue thereof is particularly preferable.
In the case where it is desired to improve the sealability of the heat-shrinkable film with a solvent, the content of the alicyclic dicarboxylic acid residue in the polyester resin (A) is increased and the polyester resin (B). It is preferable to copolymerize an amorphous component such as an isophthalic acid residue as the aromatic dicarboxylic acid residue.

  The content of the aromatic dicarboxylic acid residue is 50 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more, and most preferably 90 mol% in all dicarboxylic acid residue components. More than mol%. Moreover, there is no restriction | limiting in particular in the upper limit of the said content rate, What is necessary is just 100 mol% or less. If the content rate of an aromatic dicarboxylic acid residue is 50 mol% or more, favorable heat resistance can be provided to the heat-shrinkable film obtained.

  The dicarboxylic acid residue component constituting the polyester resin (B) can be copolymerized with a dicarboxylic acid residue other than the aromatic dicarboxylic acid residue component as long as the effects of the present invention are not impaired. Examples of such dicarboxylic acid residues include aliphatic dicarboxylic acid residues derived from malonic acid, succinic acid, adipic acid, azelaic acid, sebacic acid and the like, or ester derivative residues thereof, trimellitic acid, trimesic acid, pyrone A trifunctional or higher polyfunctional carboxylic acid residue derived from merit acid or the like or an ester derivative residue thereof can be exemplified.

  Moreover, the diol residue component which comprises a polyester-type resin (B) has a C2-C12 aliphatic diol residue as a main component. Examples of the diol residue include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6 -Residues derived from hexanediol, 1,10-decanediol, 2,2-dimethyl-1,3-propanediol, diethylene glycol, etc., among which ethylene glycol residue, 1,2-butanediol residue Alternatively, 1,4-butanediol residue is preferable, and ethylene glycol residue or 1,4-butanediol residue is particularly preferable.

  The content of the aliphatic diol residue having 2 to 12 carbon atoms contained in the diol residue component is 50 mol% or more, and 70 mol% or more with respect to the total diol residue component (100 mol%). Preferably, 80 mol% or more is more preferable, and 90 mol% or more is most preferable. When the aliphatic diol residue is a 1,4-butanediol residue, the content of 1,4-butanediol residue is preferably 80 mol% or more of all diol residue components, and 90 mol% More preferably, it is the above. In addition, when the aliphatic diol residue is an ethylene glycol residue, the content of the ethylene glycol residue may be 70 mol% or more in the total diol residue component from the viewpoint of obtaining a good shrinkage finish. Preferably, it is 80 mol% or more.

  The polyester resin (B) may further contain a polyether residue component. The type of the polyether residue component is not particularly limited, but a polyalkylene glycol residue is preferable from the viewpoint of shrink finish in the heat shrinkable film. Examples of polyalkylene glycol residues include polyethylene glycol, polypropylene glycol, polytrimethylene glycol, polytetramethylene glycol, polyhexamethylene glycol, polyalkylene glycol residues derived from ethylene oxide and propylene oxide blocks or random copolymers. A group can be exemplified. Among these, polyethylene glycol residues and polytetramethylene glycol residues are preferable, and from the viewpoint of increasing the degree of polymerization in the polyester resin (B) and improving the shrink finish of the resulting polyester heat shrinkable film, A tetramethylene glycol residue is particularly preferred. The polyether residue component may be copolymerized alone or in combination of two or more.

  When the polyether residue component contains a polyalkylene glycol residue, the number average molecular weight of the polyalkylene glycol from which the polyalkylene glycol residue can be derived is 500 or more, preferably 600 or more, and 6,000 or less, preferably Is desirably 4,000 or less, more preferably 3,000 or less. If the number average molecular weight of the polyalkylene glycol is 500 or more, the tensile elasticity modulus of the resulting polyester heat-shrinkable film does not become too high. On the other hand, if the upper limit is 6,000, the resulting polyester heat The transparency of the shrinkable film becomes good.

  In addition, the polyalkylene glycol may be used in combination of plural kinds having different number average molecular weights. When a plurality of types are used in combination, the number average molecular weight in a uniformly mixed state is preferably within the above range. The number average molecular weight of the polyalkylene glycol can be measured by a general method such as gel permeation chromatography.

  When the polyester-based resin (B) contains the polyalkylene glycol residue component, the content of the polyalkylene glycol residue is 0.5 mol% or more, preferably 1 mol% or more in all diol residue components. And less than 5 mol%, preferably less than 3 mol%. If the content of the polyalkylene glycol residue is 0.5 mol% or more, when a heat-shrinkable film is formed, a good shrinkage finish can be imparted to the film, and if the upper limit is less than 5 mol%, While suppressing the extreme fall of the glass transition temperature of a polyester-type resin (B), the favorable heat resistance of a film can be maintained, the elongation aging deterioration of a film can also be suppressed.

  When the polyether component is obtained by reacting a dicarboxylic acid compound and a diol compound to obtain a polyester resin, a polyester copolymer is obtained as a single copolymer component by partially mixing polyalkylene glycol in the diol compound. It can be contained in the resin (B).

  In the polyester resin (B), diol residue components other than the aliphatic diol residue having 2 to 12 carbon atoms may be copolymerized as long as the effects of the present invention are not impaired. Examples of the diol residue component include 1,1-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,2-cyclohexanediol, Various diol residue components derived from 1,4-cyclohexanediol and the like can be exemplified. In addition, cyclohexanedimethanol includes all combinations of cis isomer and trans isomer as in the case of cyclohexanedicarboxylic acid.

  The polyester resin (B) preferably has a glass transition temperature of less than 60 ° C. measured by a differential scanning calorimeter (DSC) from the viewpoint of improving the shrink finish of the heat-shrinkable film obtained. More preferably, it is not higher than ° C. The glass transition temperature (Tg) of the polyester resin (B) can be measured using the same method as that for the polyester resin (A).

<Polyester resin (C)>
The polyester-based resin (C) is composed of a dicarboxylic acid residue component containing an aromatic dicarboxylic acid residue as a main component and a diol residue component containing an alicyclic diol residue. And an alicyclic diol residue is contained 10 mol% or more and 40 mol% or less in all diol residue components.

  The dicarboxylic acid residue component of the polyester resin (C) has an aromatic dicarboxylic acid residue as a main component. The aromatic dicarboxylic acid residue is preferably a residue derived from terephthalic acid or an ester derivative thereof from the viewpoint of obtaining a good shrinkage finish when formed into a heat-shrinkable film.

  When the aromatic dicarboxylic acid residue component is a terephthalic acid residue, the content of the terephthalic acid residue is preferably 60 mol% or more, and preferably 70 mol% or more in the total dicarboxylic acid residue component. More preferably, it is particularly preferably 80 mol% or more. Moreover, there is no restriction | limiting in particular in the upper limit of the said content rate, What is necessary is just 100 mol% or less. If the content rate of a terephthalic acid residue is 60 mol% or more, the deterioration with time of elongation of the heat-shrinkable film obtained from the composition can be suppressed.

  When the aromatic dicarboxylic acid residue component contains a terephthalic acid residue and other dicarboxylic acid residues, there are no particular restrictions on the other dicarboxylic acid residue components, for example, isophthalic acid, orthophthalic acid, phenylenedioxydioxide. Acetic acid, 4,4′-diphenyldicarboxylic acid, 4,4′-diphenoxyethanedicarboxylic acid, 4,4′-diphenylether dicarboxylic acid, 4,4′-diphenylsulfone dicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2 Residues derived from one or more of 1,6-naphthalenedicarboxylic acid or ester derivatives thereof can be copolymerized in such a range that the total of all dicarboxylic acid residue components is 100 mol%.

  Examples of the alicyclic diol residue constituting the alicyclic diol residue component of the polyester resin (C) include 1,1-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, and 1,3-cyclohexanedim Residues derived from methanol, 1,4-cyclohexanedimethanol, 1,2-cyclohexanediol, 1,4-cyclohexanediol, etc. can be mentioned, among which 1,4-cyclohexanedimethanol residue is the main component. It is preferably included. As described above, cyclohexanedimethanol may be in any range between 100% cis isomer and 100% trans isomer, and includes all combinations therebetween. Among these, from the viewpoint of improving the heat shrinkability of the formed heat-shrinkable film, it is preferably a residue derived from 1,4-cyclohexanedimethanol containing 20% or more and 100% or less of a trans isomer. .

  The polyester resin (C) contains the alicyclic diol residue in a ratio of 10 mol% to 40 mol% in all diol residue components. By including alicyclic diol residues in a proportion of 10 mol% or more and 40 mol% or less in all diol residue components, the resulting heat-shrinkable film is imparted with good transparency and shrinkage finish. be able to. The content of the alicyclic diol residue is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more in the total diol residue component, from the viewpoint of further enhancing the above characteristics, and It is desirable to make it 40 mol% or less, preferably 35 mol% or less, and more preferably 33 mol% or less.

  Examples of the diol residue component other than the alicyclic diol residue component of the polyester resin (C) include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, Various residues derived from 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 2,2-dimethyl-1,3-propanediol, diethylene glycol and the like Examples of the group include ethylene glycol residues. The content of these diol residues is in a range where the total with the aliphatic diol residue component is 100 mol%.

  If the polyester resin (C) is within a range not impairing the effects of the present invention, 4,4′-dihydroxybiphenyl, 2,2-bis (4′-hydroxyphenyl) propane, and 2,2-bis (4 Aromatic diols such as' -β-hydroxyethoxyphenyl) propane, bis (4-hydroxyphenyl) sulfone, bis (4-β-hydroxyethoxyphenyl) sulfone, glycolic acid, p-hydroxybenzoic acid, p-β-hydroxy Monofunctional residue components derived from hydroxycarboxylic acids such as ethoxybenzoic acid, alkoxycarboxylic acids, stearic acid, stearyl alcohol, benzyl alcohol, benzoic acid, t-butylbenzoic acid, benzoylbenzoic acid, tricarballylic acid, hexane Tricarboxylic acid, trimellitic acid, trimesic acid, pyromellitic acid, Derived from nzophenonetetracarboxylic acid, naphthalenetetracarboxylic acid, 1,2,6-hexanetriol, gallic acid, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, sorbitol, dipentaerythritol, polyglycerol, etc. A trifunctional or higher polyfunctional residue component may be copolymerized.

  The polyester resin (C) preferably has a glass transition temperature of 60 ° C. or higher as measured by a differential scanning calorimeter (DSC) from the viewpoint of preventing deterioration of the heat-shrinkable film obtained with the lapse of time. The upper limit is not particularly limited, but is preferably 80 ° C. or less from the viewpoint of ease of molding. In addition, the glass transition temperature (Tg) of polyester-type resin (C) can be measured using the method similar to polyester-type resin (A) and (B).

  The polyester resins (A) to (C) are dissolved in a mixed solvent of phenol / 1,1,2,2-tetrachloroethane (mass ratio 1: 1), and the intrinsic viscosity measured at 30 ° C. is usually 0. 0.4 dl / g or more, preferably 0.6 dl / g or more, more preferably 0.7 dl / g or more, 1.5 dl / g or less, preferably 1.2 dl / g or less, more preferably 1.1 dl / g. It is the range below g. If the intrinsic viscosity is 0.4 dl / g or more, sufficient mechanical properties can be obtained, and if it is 1.5 dl / g or less, molding is easy when molding a molded product.

  The polyester resins (A) to (C) constituting the composition of the present invention are produced by a conventional production method of a polyester resin, that is, a batch polymerization method or a continuous method by a direct polymerization method or a transesterification method. Can do. Here, the aforementioned arbitrary copolymer component can be added at any stage of the polycondensation reaction process. It is also possible to produce a polyester resin by producing an oligomer having a low polymerization degree from a dicarboxylic acid compound and a diol compound, and polycondensing this with a polyether compound and / or any of the aforementioned copolymerization components. it can.

  The polyester-based resin obtained by the polycondensation reaction is usually extracted in a strand form from an extraction port provided at the bottom of the polycondensation reaction tank, and is cooled with water or after water cooling, and then cut into a pellet. The Furthermore, by subjecting the pellets after polycondensation to heat treatment and solid phase polycondensation, the degree of polymerization can be further increased, and reaction by-products such as acetaldehyde and low-molecular oligomers can be reduced.

  In the production method, the esterification reaction is performed using an esterification reaction catalyst such as antimony trioxide, an organic acid salt such as antimony, titanium, magnesium, calcium, or an organic metal compound, if necessary. The transesterification reaction can be carried out using a transesterification reaction catalyst such as an organic acid salt or an organic metal compound such as lithium, sodium, potassium, magnesium, calcium, manganese, titanium, or zinc, if necessary. It can be carried out.

  The polycondensation reaction is performed in the presence of phosphorus compounds such as orthophosphoric acid, phosphorous acid, hypophosphorous acid, polyphosphoric acid, and esters and organic acid salts thereof, and, for example, antimony trioxide, germanium dioxide, It can be carried out using a metal oxide such as germanium tetroxide, or a polycondensation catalyst such as an organic acid salt or an organic metal compound such as antimony, germanium, zinc, titanium or cobalt. Of these polycondensation catalysts, at least one selected from tetrabutoxy titanate, antimony trioxide, and germanium dioxide is preferably used. Further, an antifoaming agent such as silicone oil can be added to promote defoaming in the polycondensation process. In addition, the catalyst amount is usually 5 mass ppm or more and 2000 mass ppm as a metal amount (atomic conversion amount) with respect to the theoretical yield of the obtained polyester-based resin for the esterification reaction catalyst, the transesterification reaction catalyst, and the polycondensation catalyst. Hereinafter, it is preferably used in the range of 10 mass ppm or more and 500 mass ppm or less.

  The composition of the present invention may further contain inorganic and / or organic fine particles from the viewpoint of imparting blocking resistance and slipperiness when formed into a heat-shrinkable film. The content of the fine particles is 0.005% by mass or more, preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and 1% by mass or less, based on the mass of the entire composition. Preferably it is 0.6 mass% or less, More preferably, it is desirable that it is the range of 0.5 mass% or less.

  Examples of the inorganic fine particles include silica, alumina, titania, kaolin, clay, calcium carbonate, calcium phosphate, lithium fluoride, carbon black, and catalysts such as alkali metals, alkaline earth metals, and phosphorus compounds at the time of polyester polymerization. The resulting precipitates can be mentioned. Examples of the organic fine particles include various crosslinked polymers.

The average particle size of the organic or inorganic fine particles is 0.001 μm or more, preferably 0.005 μm or more, more preferably 0.01 μm or more, from the viewpoint of obtaining the above-described effects of blocking resistance and easy slipping. It is desirable that the thickness be in the range of 6 μm or less, preferably 4 μm or less, more preferably 3 μm or less.
The “average particle size” as used herein means a 50% volume average particle size (d50) measured by a method such as a laser diffraction method, an electromagnetic wave scattering method such as a dynamic light scattering method, or a light transmission method such as a centrifugal sedimentation method. ), But if there is a difference depending on the measurement method, use the value determined by the laser diffraction method.

  The mixing method of the organic or inorganic fine particles is not particularly limited, and can be added during the polymerization process of the polyester resin, or can be mixed during the production process of the polyester resin composition or the molding process of the polyester heat shrinkable film. You can also

  The composition of this invention may contain other resin in the range which does not impair the effect of this invention. Examples of the other resin include polyethylene resins, polypropylene, modified maleic anhydrides thereof, polyolefin resins such as ionomers, thermoplastic resins such as polyamide resins and polystyrene resins, and thermoplastic elastomers.

  Furthermore, the composition of the present invention is an antioxidant such as phenolic, phosphorus, thioether, benzotriazole, benzophenone, benzoate, hindered amine, cyanoacrylate, etc., as long as the effects of the present invention are not impaired. Light stabilizers, inorganic or organic crystal nucleating agents, molecular weight modifiers, hydrolysis resistance, antistatic agents, lubricants, mold release agents, plasticizers, flame retardants, flame retardant aids, foaming agents, coloring It may contain additives such as additives and dispersion aids, and reinforcing materials such as glass fiber, carbon fiber, mica and potassium titanate fiber.

  In the composition of the present invention, the polyester-based resin (A), the polyester-based resin (B), and the polyester-based resin (C) are mixed simultaneously or sequentially with a predetermined amount based on the polyester-based resin (A). Is obtained. The mixing amount of the polyester resin (B) is 20 parts by mass or more, preferably 25 parts by mass or more, more preferably 30 parts by mass with respect to 100 parts by mass of the polyester resin (A). And it is 600 mass parts or less, Preferably it is 400 mass parts or less, More preferably, it is 200 mass parts or less. The mixing amount of the polyester resin (C) is 80 parts by mass or more, preferably 90 parts by mass or more, more preferably 100 parts by mass or more, and 1700 parts by mass with respect to 100 parts by mass of the polyester resin (A). Part or less, preferably 1400 parts by weight or less, more preferably 1000 parts by weight or less. By adjusting the mixing amount of the polyester resins (A) to (C) within the above range, a good shrink finish can be obtained when the heat-shrinkable film is formed. In addition, the conditions used by the manufacturing method of the conventional polyester resin composition can be applied to conditions, such as temperature and pressure at the time of mixing of the said polyester resin (A) thru | or (C).

[Polyester heat shrinkable film]
The film of this invention is a film formed from the resin composition containing the said polyester-type resin (A), the said polyester-type resin (B), and the said polyester-type resin (C), and 70 degreeC warm water When the film is immersed for 10 seconds, the heat shrinkage in the main film shrinkage direction is 20% or more, preferably 23% or more, more preferably 25% or more, and less than 40%, preferably 38% or less, more preferably 35% or less. The film of the present invention has a heat shrinkage rate in the main film shrinkage direction of 40% or more, preferably 43% or more, more preferably 45% or more when immersed in warm water of 80 ° C. for 10 seconds, and the upper limit is 65%, preferably 60%, more preferably 58%. The heat shrinkage rate of the film of the present invention can be adjusted by increasing or decreasing the content of the alicyclic dicarboxylic acid residue contained in the polyester resin (A) constituting the composition of the present invention. For example, when it is desired to increase the heat shrinkage rate in the main film shrinkage direction, it can be adjusted by increasing the content of the alicyclic dicarboxylic acid residue contained in the polyester resin (A).

  In the present specification, the “main shrinkage direction” means a direction having a large thermal shrinkage rate in the longitudinal direction (longitudinal direction) and the transverse direction (width direction). The direction corresponding to the direction is meant, and the “orthogonal direction” means a direction perpendicular to the main contraction direction.

  The film of the present invention has a difference between the heat shrinkage rate in the main shrinkage direction when immersed in warm water at 80 ° C. for 10 seconds and the heat shrinkage rate in the main shrinkage direction when immersed in warm water at 70 ° C. for 10 seconds. It is desirable that it is 25% or less, preferably 23% or less, more preferably 21% or less.

  The film of the present invention exhibits a relatively low shrinkage rate of 20% or more and less than 40% in warm water at 70 ° C., and in the warm water at 80 ° C. An appropriate shrinkage rate can be maintained at a shrinkage rate of 40% to 65%. Furthermore, the film of the present invention has a difference in shrinkage between hot water of 70 ° C. and 80 ° C. of 25% or less. If the shrinkage rate in the main film shrinkage direction is 20% or more and less than 40% in warm water at 70 ° C, and the difference between the film shrinkage rates at 70 ° C and 80 ° C is 25% or less, it is from 70 ° C to 80 ° C. A gentle contraction curve can be obtained in the temperature raising step, and generation of wrinkles and the like can be suppressed during contraction. Further, at 80 ° C., the shrinkage rate in the main shrinkage direction of the film is 40% or more, so that it is possible to shrink and coat a normal container, and further, the upper limit is 65%, so that a gentle shrinkage curve is obtained and the shrinkage Occasional wrinkles can be suppressed.

  The film of the present invention has an average shrinkage in the orthogonal direction of 5% or less, preferably 4% or less, more preferably 3% or less when immersed in warm water of 70 ° C. to 90 ° C. for 10 seconds. Since the film of the present invention has an average shrinkage in the direction perpendicular to the film within the above temperature range of 5% or less, it is possible to suppress the occurrence of sink marks in the direction perpendicular to the label when it is formed into a heat-shrinkable label. In the temperature range from to 90 ° C., the occurrence of shrinkage spots and wrinkles on the label can be suppressed, and the shrinkage characteristics and commercial value can be improved.

  The natural shrinkage ratio in the main shrinkage direction and the orthogonal direction of the film of the present invention is, for example, 2.0% or less, preferably 1.0% or less, more preferably 0.5% under the condition after storage at 30 ° C. for 30 days. % Or less. Since the natural shrinkage rate under the above conditions is 2.0% or less, even when the film of the present invention is stored for a long period of time, it can be stably attached to a container or the like, and practical problems are unlikely to occur.

The film of the present invention has a tensile modulus in the main shrink direction (TD) of 2,500 MPa or more, preferably 3,000 MPa or more, more preferably 3,500 Mpa or more, and the upper limit is 7,000 MPa, preferably 6,000 MPa. More preferably, it is 5,500 MPa. The tensile modulus of elasticity of the film of the present invention in the direction perpendicular to the main shrinkage direction (MD) is 1,000 MPa or more, preferably 1,300 MPa or more, more preferably 1,800 MPa or more, and the upper limit is 3,000 MPa, preferably It is 2,700 MPa, more preferably 2,200 MPa. For the tensile modulus, specimens having a width of 5 mm and a length of 70 mm were taken in the orthogonal direction (MD) and the main contraction direction (TD), respectively, and the specimens were placed in a temperature-controlled room at 23 ° C. and 50 RH% with a chuck spacing of 50 mm. After setting in the tensile tester, the stress-strain curve is obtained at a tensile test speed of 5 mm / min, and the tensile modulus can be obtained from the following formula (1) in the straight line portion immediately after the start of the test.
Tensile modulus = Stress difference due to the original average cross-sectional area between two points on a straight line / Strain difference between the same two points ... (1)

  The film of the present invention has a right-angled tear strength measured in accordance with JIS K7128-3 of 100 N / mm or more in the orthogonal direction (MD), preferably 150 N / mm or more, and 400 N / mm or less, preferably 350 N / mm. mm or less, and 200 N / mm or more, preferably 300 N / mm or more, and more preferably 350 N / mm or more in the main shrinkage direction (TD).

  The rupture resistance of the film of the present invention is evaluated by tensile elongation, and in a tensile test under a 0 ° C. environment, the elongation is 100% or more, preferably 200% or more in the orthogonal direction (MD) of the film, particularly for label applications. More preferably, it is 300% or more.

  The elongation change with time of the film of the present invention is 50% or more under the condition of 20 mm between chucks in a perpendicular direction (MD) and a pulling speed of 200 mm / min. It can be represented by the number that extends (ie, beyond the yield point). For example, after storage at 30 ° C. for 30 days, a test piece cut out at 15 mm in the main shrink direction (TD) of the film, 50 mm to 150 mm, preferably 50 mm to 100 mm, more preferably 100 mm in the orthogonal direction (MD), When the tensile test is performed under the conditions of a distance between chucks of 20 mm, 23 ° C., 50% RH, and a tensile speed of 200 mm / min, the number of stretches by 50% or more is 80% or more of all the test pieces in the case of the film of the present invention. It is preferably 90% or more, and most preferably 100%.

  The perforation of the film of the present invention is evaluated based on whether a heat-shrinkable film in which a perforation of a predetermined size is engraved is torn along the perforation and the cut is torn along the perforation. can do. The perforation of the perforation is the content of the alicyclic dicarboxylic acid residue in the polyester resin (A) and the content of the alicyclic diol residue in the polyester resin (C) containing the alicyclic diol residue. And by adjusting the blending amount of both resins. For example, the content (preferably 10 mol% or more) of the alicyclic dicarboxylic acid residue in the polyester tree (A) and the content (preferably 20) of the alicyclic diol residue in the polyester resin (C). Perforation of the perforation can be improved. Further, for example, by adjusting the blending amount of the polyester-based resin (C) to be 2.3 times or more of the blending amount of the polyester-based resin (A), the perforation can be improved.

  Here, the “perforation” means, for example, in the case of a heat-shrinkable film (or heat-shrinkable label), used from a container engraved in the orthogonal direction and / or main shrinkage direction and covered with the heat-shrinkable film. This refers to a group of perforated continuous small holes provided to facilitate the separation when the film is separated later.

  The size and shape of the perforation are not particularly limited. For example, the perforation has a length of 0.05 to 2 mm, a width of 0.5 to 2 mm, a rectangular shape or a rectangular shape, or a diameter or a long axis length of about 0.05 to 2 mm. A circular or elliptical perforation may be mentioned, and a rectangular perforation of about 0.5 to 1 mm is preferable. The perforations can be formed by pressing a disk provided with a large number of needle-like protrusions. For example, by appropriately adjusting the shape and interval of the needle-like protrusions, perforations of various shapes are formed on the film at regular intervals. Can be formed.

  The perforation evaluation method is, for example, forming the film of the present invention cut into a predetermined size into a cylindrical shape, covering the bottle, tearing it with a fingertip along the perforation after heat shrink processing, It can be evaluated by a method of visually confirming whether or not cutting has occurred in the middle of the eyes.

  The transparency of the film of the present invention is, for example, when a film having a thickness of 50 μm is measured in accordance with JIS K7105, the haze value is 10% or less, preferably 7% or less, and preferably 5% or less. Is more preferable. Since the film of the present invention has a haze value of 10% or less, good transparency can be obtained at the time of film formation, and a display effect can be achieved.

  The thickness of the film of the present invention is not particularly limited, but when used for heat-shrinkable labels, the thickness of the film is 10 μm or more, preferably 20 μm or more, and 100 μm or less, preferably 80 μm or less. Is desirable. If the thickness of the film is 10 μm or more, there is an advantage that secondary processing is easy, and if the thickness of the film is 100 μm or less, good workability of the film can be maintained.

Next, although the manufacturing method of the film of this invention is demonstrated concretely, the manufacturing method of the film of this invention is not limited to this.
The film of this invention can be manufactured using a conventionally well-known manufacturing method, The manufacturing method is not specifically limited. For example, the polyester resins (A) to (C) as raw materials are melt-extruded in advance in a temperature range of 200 ° C. to 300 ° C. and cut into pellets, and the pellet-like polyester resin composition is then heated to 200 ° C. A heat-shrinkable film can be produced by melt extrusion in a temperature range of 300 ° C. or lower. Moreover, a film can also be directly produced by melt-extruding the polyester resins (A) to (C) in a temperature range of 200 ° C. or more and 300 ° C. or less. It does not specifically limit as an extrusion method, A T-die method, a tubular method, etc. can be used.

  When producing a uniaxially stretched film using the T-die method, after extrusion, the surface temperature is rapidly cooled on a casting drum having a temperature range of 15 ° C. to 80 ° C. to form an unstretched film having a thickness of 30 μm to 300 μm. To do. Next, using a heated longitudinal stretching roll, unstretched under conditions of a roll temperature of 60 ° C. or more and 120 ° C. or less, a draw ratio of 1.0 to 1.3 times, preferably 1.0 to 1.1 times. Stretch the film. Next, using a tenter, the film is stretched under conditions of a stretching temperature of 60 ° C. or higher and 120 ° C. or lower and a draw ratio of 1.7 times or higher and 7.0 times or lower, and then heat-treated at a temperature of 55 ° C. or higher and 100 ° C. or lower. .

  When a biaxially stretched film is produced using the T-die method, after extrusion, the surface temperature is rapidly cooled on a casting drum having a temperature range of 15 ° C. to 80 ° C., and an unstretched film having a thickness of 40 μm to 900 μm Form. Next, using a heated longitudinal stretching roll, unstretched under the conditions of a roll temperature of 60 ° C. or more and 120 ° C. or less, a stretching ratio of 1.7 times or more and 7.0 times or less, and preferably 2.5 times or more and 6.0 times or less. Stretch the film. Next, after stretching under the conditions of a stretching temperature of 60 ° C. or more and 120 ° C. or less, a stretching ratio of 1.7 times or more and 7.0 times or less, preferably 2.5 times or more and 6.0 times or less, using a tenter, It heats and winds up at the temperature of 55 to 100 degreeC.

[Polyester heat shrinkable multilayer film]
The film of the present invention can be formed into a multilayer film by laminating other layers made of heterogeneous materials or homogeneous materials. The multilayer film of the present invention may include at least one layer of the film of the present invention (single layer). For example, in addition to the film of the present invention, two or three layers or three or five layers composed of one or two different kinds of materials. It can be composed of a plurality of layers depending on the application, such as 4 types and 7 layers. Especially, 2 types 3 layers or 3 types 5 layers which used the film of this invention as an intermediate | middle layer are suitable. For example, the front and back layers are preferably layers made of a resin excellent in printing and sealing properties, and the film of the present invention is preferably used for the intermediate layer in order to impart shrinkage characteristics.

  The multilayer film of the present invention is preferably a resin with low crystallinity as the resin used for the front and back layers. For example, when a polyester resin is used, the diol residue contained in the diol residue component is 1,4-butanediol. And a resin whose content is 25 mol% or less in all diol residue components, and whose content of 1,4-cyclohexadimethanol residues is 25 mol% or more in all diol residue components It is desirable to use it.

  The thickness ratio of the multilayer film of the present invention is, for example, in the case of two types and three layers, the thickness ratio in the range of front and back layers: intermediate layer: front and back layers = 1: 2: 1 to 1: 10: 1. it can. In the case of 3 types and 5 layers, [front / back layer: adhesive layer]: intermediate layer: [adhesive layer: front / back layer] = [1]: 2: [1] to [1]: 10: [1] thickness The thickness ratio of [front and back layers: adhesive layer] can be in the range of 1: 1 to 5: 1.

  In the multilayer film of the present invention, the thickness of the entire film can be appropriately selected depending on the application, and is usually in the range of 10 μm to 600 μm. For example, in the case of packaging applications such as foods, beverages, and pharmaceuticals, the total film thickness is in the range of 15 μm to 400 μm, preferably 15 μm to 200 μm. When used as a label for polyester bottles, glass bottles, and other plastic containers, the thickness is 20 μm or more and 100 μm or less, preferably 80 μm or less, more preferably 60 μm or less. Is preferred.

[Heat-shrink label and container equipped with the label]
The film of the present invention has excellent shrinkage finish properties, transparency, mechanical strength such as film stiffness (rigidity at room temperature), fracture resistance, and the like, and the natural shrinkage rate and fragility deterioration with time are small. Applications are not particularly limited, but for PET bottles (300 ml to 2 liter round and square bottles), shrink labels, various foods and articles, shrink and bundling packaging, various container caps It can be suitably used as a heat-shrink label for sealing applications, shrinkable tubes of various foods and articles, and a container equipped with this shrinkable label can be obtained. And the heat-shrinkable label of this invention and the container equipped with this label can be produced using a conventionally well-known method.

  The film of the present invention is not only a heat-shrinkable label material of a plastic molded product that is deformed when heated to a high temperature, but also a material that is extremely different from the heat-shrinkable film of the present invention in terms of coefficient of thermal expansion, water absorption, etc. At least one selected from polyolefin resins such as porcelain, glass, paper, polyethylene, polypropylene, and polybutene, polymethacrylate resins, polycarbonate resins, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, and polyamide resins Can be suitably used as a heat-shrinkable label material of a container using as a constituent material.

  Although the container which can utilize the film of this invention is not specifically limited, A plastic container can be used suitably. As a material constituting the plastic container, in addition to the above resins, polystyrene, rubber-modified impact-resistant polystyrene (HIPS), styrene-butyl acrylate copolymer, styrene-acrylonitrile copolymer, styrene-maleic anhydride copolymer , Acrylonitrile-butadiene-styrene copolymer (ABS), methacrylate-butadiene-styrene copolymer (MBS), polyvinyl chloride resin, phenol resin, urea resin, melamine resin, epoxy resin, unsaturated polyester resin, A silicone resin etc. can be mentioned. These plastic packages may be a mixture of two or more resins or a laminate.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not restrict | limited at all by these Examples.

A. Measurement Method Composition Analysis of Polyester Resin Used in Each Example and Comparative Example, 1,4-Cyclohexanedicarboxylic Acid (hereinafter referred to as “CHDA”) cis / Trans Content, Intrinsic Viscosity, and Glass Transition Temperature The measurement of was performed by the following method.

(Composition analysis of polyester resin)
A solution (sample concentration: 100 mg / 1 ml solvent) in which various polyester resins were dissolved in deuterated chloroform (solvent) was used as a sample, and this solution sample was analyzed by monitoring ¹ H with a nuclear magnetic resonance apparatus (NMR). . Regarding the dicarboxylic acid residue, the mol% of the compound to be analyzed with respect to all the dicarboxylic acid residue components was determined, and for the diol residue, the mol% with respect to the total diol residue component of the compound to be analyzed was determined. .

(Method for measuring CHDA cis / trans content)
In a 50 ml volumetric flask, 0.2 g of CHDA was dissolved in 1.2 ml of 4M (4N) sodium hydroxide. Subsequently, 40 ml of purified water was added to the obtained solution, and after adjusting to pH 5 with 200 μl of phosphoric acid, pure water was added to make 50 ml. This was measured under the following conditions using liquid chromatography, and the trans isomer and cis isomer content were determined from the peak areas derived from the trans isomer and cis isomer.
Measuring device: LC-10AD manufactured by Shimadzu Corporation
Column: J'share ODS-H80 4.6 mm x 250 mm
Measurement temperature: 50 ° C
Moving layer: Acrylonitrile / pure water / H ₃ PO ₄ = 200/800/4 (volume ratio)
Flow rate: 0.6ml / min
Detector: UV (210 nm)
Injection volume: 20 μl

(Measurement of intrinsic viscosity)
A polyester resin chip sample of 0.5 g was mixed with phenol / tetrachloroethane (mass ratio 1/1) as a solvent and dissolved at 110 ° C. for 30 minutes so that the concentration (c) was 1.0 g / dl. A solution was prepared. Using the Ubbelohde viscometer at 30 ° C., the relative viscosity (ηrel) with respect to the solvent alone (c = 0) was measured, and the relative viscosity (ηrel) -1 was defined as the specific viscosity (ηsp). The ratio (ηsp / c) to c) was determined. Similarly, the concentration (c) is 0.5 g / dl, 0.2 g / dl, and 0.1 g / dl, and the respective ratios (ηsp / c) are obtained. From these values, the concentration (c) is set to 0. The ratio (ηsp / c) when extrapolated was determined as intrinsic viscosity [η] (dl / g).

(Measurement of glass transition temperature)
About 10 mg of various polyester resins were melted at 280 ° C. for 5 minutes, then immersed in liquid nitrogen, quenched, and made amorphous, using a differential scanning calorimeter “DSC822e” manufactured by METTLER TOLEDO, The glass transition temperature was measured at a heating rate of 20 ° C./min.

B. Evaluation Method The polyester heat-shrinkable film produced in each example and comparative example was evaluated by the following method.

(1) Heat Shrinkage The polyester heat-shrinkable film obtained in each Example and Comparative Example was cut to a size of 70 mm in the main shrinkage direction and 10 mm in the orthogonal direction to prepare a sample. Marks with 50mm intervals in the direction of main contraction of the sample are measured, and each mark interval (A) is measured after being immersed in a hot water bath at 70 ° C and 80 ° C for 10 seconds and then immersed in cold water at 23 ° C for 30 seconds. The thermal contraction rate was calculated by the following formula (2).
Thermal contraction rate (%) = 100 × (50−A) / 50 (2)

(2) Shrinkage finish The polyester-based heat-shrinkable film obtained in each of the examples and comparative examples was sealed in a cylindrical shape so that the main shrinkage direction was the transverse direction, and then this cylindrical film was filled with 500 ml of water. The film was placed on the bottle and allowed to pass through a steam shrink tunnel adjusted in a temperature range from 70 ° C. to 80 ° C. for 5 seconds, and then the shrinkage state of the film was observed and judged according to the following criteria.
○: Appearance with a clear appearance without shrinkage unevenness and wrinkles Δ: Appearance with slight shrinkage unevenness and wrinkles ×: Appearance with significant shrinkage unevenness and wrinkles

(3) Perforation perforation Cut out from the polyester heat-shrinkable film obtained in each Example and Comparative Example to a size of 60 mm in the main shrinkage direction and 300 mm in a direction perpendicular to the main shrinkage, and cylindrical with a folding diameter of 105 mm The heat-shrinkable label was produced by processing. Next, one rectangular perforation was formed in the orthogonal direction on the heat-shrinkable label using a sewing blade having a blade size of 0.7 mm × 0.7 mm and a blade-to-blade spacing of 0.7 mm. Next, using a steam tunnel (“SKT-3000” manufactured by Keiyu System Co., Ltd.), a 350 ml PET bottle filled with water was coated with the heat-shrinkable label from the bottom to the neck. Thereafter, the bottle was refrigerated to 5 ° C., and the bottle immediately after taking out from the refrigerator was torn the perforation of the label with a fingertip, and at that time, it was visually observed whether or not cutting occurred in the middle of the perforation. . The number of measurements was set to 5 and the determination was made according to the following criteria.
◯: When there are 3 or more cuts without any problem along the perforation or while feeling resistance to the bottom of the bottle △: Cut to some extent along the perforation, but peel the apple before reaching the bottom When there are 3 or more items in the state ×: When there are 3 or more apples that are barely cut along the perforation and peeled

(4) Elongation over time Polyester heat-shrinkable film left in a gear oven at 30 ° C. for 30 days is carefully cut out with a feather blade to a size of 15 mm in the main shrinkage direction and 50 mm in the orthogonal direction, and TM-20 manufactured by Intesco 10 were measured in the orthogonal direction at an interval of 20 mm between the chucks and a tensile speed of 200 mm / min, and the number extending 50% or more was measured. Of all the samples, the number that extends by 50% or more is 9 or more and 10 or less, ◎, 7 or more and 8 or less, ◯, 5 or more and 6 or less, △, 4 or less Some were represented as x.

C. Production of raw material polyester resin (1) Polyester resin 1 (PET1)
Polyester resin 1 was produced by the method of Production Example 1 described below. As a result of analyzing the composition of the polyester resin 1 by the above method, 10 mol% in the dicarboxylic acid residue component is CHDA, 90 mol% is terephthalic acid (hereinafter abbreviated as “TPA”), and the diol residue. Of the components, 98 mol% was ethylene glycol (hereinafter abbreviated as “EG”), and 2 mol% was diethylene glycol (hereinafter abbreviated as “DEG”). Moreover, it was 0.84 dl / g as a result of measuring the intrinsic viscosity of the polyester-type resin 1 by the said method.

<Production Example 1>
Using a batch polymerization apparatus equipped with a slurry preparation tank, an esterification reaction tank, a polycondensation tank, and a pelletizing apparatus, TPA prepared in advance in a slurry tank in an esterification reaction tank containing 50 kg of an esterification reaction product: 38 0.8 kg (233.6 mol), CHDA having a trans isomer content of 95% measured by the method described above: 4.5 kg (26.2 mol), EG: 19.3 kg {311 mol (dicarboxylic acid: EG molar ratio) = 1: 1.2)} was continuously added at a rate of 15.7 kg / hr, and the esterification reaction was carried out while continuously distilling water produced at 250 ° C. and normal pressure. . The esterification reaction was terminated by continuing the esterification reaction for another 15 minutes after completion of the slurry feed. After completion of the esterification reaction, 50 kg of the esterification reaction product was left in the esterification reaction tank and transferred to the polycondensation tank.

Subsequently, ethyl acid phosphate (hereinafter abbreviated as “EAP”) was added as a stabilizer, and cobalt acetate tetrahydrate (hereinafter abbreviated as “Co acetate”) and tetrabutoxytitanium (hereinafter abbreviated as “Co acetate”) as polymerization catalysts. (Hereinafter abbreviated as “TBT”) was added (both added as an EG solution). The addition amounts of EAP, Co acetate, and TBT were 12 mass ppm, 100 mass ppm, and 21.3 mass ppm, respectively, with respect to the theoretical yield of the polyester.
Next, while the pressure in the polycondensation tank was reduced from normal pressure to 1 mmHg over about 100 minutes, the internal temperature was increased from about 250 ° C. to about 280 ° C., and the melt polycondensation reaction was performed while distilling EG. After 4 hours from the start of decompression, the pressure was restored and the polycondensation reaction was completed. After returning the pressure in the polycondensation tank, the polyester resin was taken out in a strand form from the lower part of the tank, cooled with water, and pelletized with a cutter to obtain polyester resin pellets.

(2) Polyester resin 2 (PET2)
Polyester resin 2 was produced by the method of Production Example 2 described below. As a result of analyzing the composition of the polyester resin 2 by the above method, 20 mol% in the dicarboxylic acid residue component is a CHDA residue, 80 mol% is a TPA residue, and 98 mol% in the diol residue component is EG. Residues, 2 mol% were DEG residues. Moreover, it was 0.83 dl / g as a result of measuring the intrinsic viscosity of the polyester-type resin 2 by the said method.

<Production Example 2>
During the esterification reaction, TPA: 34.4 kg (207 mol), CHDA having a trans isomer content of 95%: 8.9 kg (51.7 mol), EG: 20.9 kg {336.7 mol (dicarboxylic acid: EG The polyester resin 2 was prepared in the same manner as in Production Example 1 except that the esterification reaction was carried out by continuously adding a slurry having a molar ratio = 1: 1.3)} at a rate of 16.1 kg / hr. Produced.

(3) Polyester resin 3 (PET3)
Polyester resin 3 was produced by the method of Production Example 3 described below. As a result of analyzing the composition of the polyester resin 3 by the above method, 25 mol% in the dicarboxylic acid residue component is CHDA residue, 75 mol% is TPA, and 98 mol% in the diol residue component is EG residue. 2 mol% was DEG residues. Moreover, it was 0.82 dl / g as a result of measuring the intrinsic viscosity of the polyester-type resin 3 by the said method.

<Production Example 3>
During the esterification reaction, TPA: 32.2 kg (193.8 mol), CHDA having a trans isomer content of 95%: 11.1 kg (64.5 mol), EG: 20.8 kg {335.1 mol (dicarboxylic acid: Polyester resin in the same manner as in Production Example 1 except that the esterification reaction was carried out by continuously adding a slurry having a molar ratio of EG = 1: 1.3)} at a rate of 16.0 kg / hr. 3 was produced.

(4) Polyester resin 4 (PET4)
“NOVADURAN 5008” manufactured by Mitsubishi Engineering Plastics was used as the polyester resin 4. As a result of analyzing the composition of the polyester resin 4 by the above method, the dicarboxylic acid residue component was 100 mol% of the TPA residue, and the diol residue component was 1,4-butanediol (hereinafter abbreviated as “BD”). It was 100 mol% of the group. Moreover, it was 0.85 dl / g as a result of measuring the intrinsic viscosity of the polyester-type resin 4 with the said method.

(5) Polyester resin 5 (PET5)
“NOVADURAN 5505” manufactured by Mitsubishi Engineering Plastics was used as the polyester resin 5. As a result of analyzing the composition of the polyester-based resin 5 by the above method, the dicarboxylic acid residue component was 100 mol% of TPA residue, and the diol residue component was 97 mol% of all diol residue components as BD residues. 3 mol% was a polytetramethylene glycol (hereinafter abbreviated as “PTMG”) residue. Moreover, it was 0.90 dl / g as a result of measuring the intrinsic viscosity of the polyester-type resin 5 by the said method.

(6) Polyester resin 6 (PET6)
“EASTAR PETG Copolyester 6763” manufactured by Eastman Chemical Co. was used as the polyester resin 6. As a result of analyzing the composition of the polyester resin 6 by the above method, the dicarboxylic acid residue component was 100 mol% of the TPA residue, the diol residue component was 66 mol% of EG residue, and 2 mol% of DEG. 32 mol% was 1,4-cyclohexanedimethanol (hereinafter abbreviated as “CHDM”) residue. Moreover, it was 0.78 dl / g as a result of measuring the intrinsic viscosity of the polyester-type resin 6 by the said method.

(7) Polyester resin 7 (PET7)
“EMBRACE Copolyester” manufactured by Eastman Chemical Co. was used as the polyester resin 7. As a result of analyzing the composition of the polyester resin 7 by the above method, the dicarboxylic acid residue component was 100 mol% of the TPA residue, the diol residue component was 72 mol% of the EG residue, and 20 mol% of the CHDM residue. Residues, 8 mol% were DEG residues. Moreover, it was 0.83 dl / g as a result of measuring the intrinsic viscosity of the polyester-type resin 7 by the said method.

Example 1
100 parts by weight of polyester-based resin 1 (PET1), 100 parts by weight of polyester-based resin 5 (PET5), 300 parts by weight of polyester-based resin 6 (PET6) were blended and dried at 60 ° C. for 24 hours, and then TEM 58 mm2 manufactured by Toshiba Machine Co., Ltd. A sheet having a width of 250 mm and a thickness of 0.20 mm was obtained by extrusion onto a cooling roll with a time discharge amount of 30 kg from a T-die die having a width of 300 mm by a shaft extruder. Subsequently, the sheet was passed through a film tenter manufactured by Kyoto Machine Co., Ltd. for 20 seconds at 90 ° C., and then stretched four times in the vertical direction with respect to the casting extrusion direction at a stretching temperature of 73 ° C. and a stretching speed of 500% / min. After that, heat treatment was performed at 78 ° C. for 20 seconds to obtain a 50 μm thick polyester heat-shrinkable film. The polyester heat-shrinkable film was evaluated by the above method. The results are shown in Table 1.

(Examples 2 to 4, Comparative Examples 1 to 4)
The raw material polyester resin (A), polyester resin (B) and polyester resin (C) are blended in the blending amounts shown in Table 1, stretched at the stretching temperatures shown in Table 1, and heat treated at the heat treatment temperatures shown in Table 1. Except for the above, a polyester heat-shrinkable film was obtained in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

(Example 5)
For production of the intermediate layer, 100 parts by mass of polyester resin 3 (PET3), 75 parts by mass of polyester resin 5 (PET5), and 325 parts by mass of polyester resin 6 (PET6) are mixed polyester chips. Was used. Moreover, the pellet which consists of 125 mass parts of polyester-type resin 6 (PET6) was used for manufacture of the front and back layers. The width of the mixed polyester chip of the intermediate layer is 30 mm by a TEM 58 mm twin screw extruder manufactured by Toshiba Machine, and the width of the mixed polyester chip of both outer layers is 7.5 mm by a 40 mm extruder manufactured by Sumitomo Heavy Industries, Ltd. with a time discharge of 7.5 kg. The two types of three-layer T die die were coextruded on a cooling roll at 270 ° C. while pulling a vacuum vent. The width was 150 mm, the thickness of both outer layers was 0.025 mm, and the thickness of the intermediate layer was 0.20 mm. A three-layer unstretched sheet was obtained. Next, the sheet was stretched in the same manner as in Example 1 to obtain a laminated heat-shrinkable film having a thickness of 50 μm (both outer layers had a thickness of 5 μm and an intermediate layer had a thickness of 40 μm).
The obtained laminated heat-shrinkable film was evaluated by the above method. The results are shown in Table 1.

As shown in Table 1, the heat-shrinkable film composed of the composition of the present invention has a good shrinkage finish and perforation in both cases of a single layer (Examples 1 to 4) and a multilayer (Example 5). It can be seen that there is little degradation over time.
On the other hand, in the case of a film not containing a resin corresponding to the polyester resin (B) in the present invention (Comparative Example 1) or in the case of a film not containing a resin corresponding to the polyester resin (A) ( In Comparative Example 2), compared with the film of the present invention, the shrinkable finish and the perforation were inferior, and the elongation was likely to deteriorate with time. Further, in the case of a film in which the blending ratio of the polyester resins (A) to (C) is outside the range of the present invention (Comparative Examples 3 and 4), the perforation and elongation with time are deteriorated from the film of the present invention. Inferior, especially the shrinkage finish was quite inferior.
From this, the film composed of the composition of the present invention has a good shrink finish and perforation as compared with conventional heat-shrinkable films, and is a film that does not easily deteriorate with time. I understand.

  When the composition of the present invention is formed into a film, the shrinkage finish of the film is good, the film can be easily cut and peeled along the perforations formed in the film, and the elongation is not easily deteriorated over time. It can be utilized as a film having various uses such as various heat-shrinkable films, heat-shrinkable labels, and food packaging.

Claims (11)

The polyester resin (A), the polyester resin (B), and the polyester resin (C) below are 20 parts by mass or more and 600 parts by mass of the polyester resin (B) to 100 parts by mass of the polyester resin (A). A polyester resin composition comprising 80 parts by mass or more and 1700 parts by mass or less of a polyester resin (C) in an amount of not more than part by mass.
(A) a dicarboxylic acid residue component containing an alicyclic dicarboxylic acid residue and a diol residue component mainly composed of an ethylene glycol residue, wherein the alicyclic dicarboxylic acid residue A polyester resin containing 5 mol% or more and 50 mol% or less of the base component.
(B) A polyester resin comprising a dicarboxylic acid residue component having an aromatic dicarboxylic acid residue as a main component and a diol residue component having an aliphatic diol residue having 2 to 12 carbon atoms as a main component.
(C) a dicarboxylic acid residue component mainly comprising an aromatic dicarboxylic acid residue and a diol residue component containing an alicyclic diol residue, wherein the alicyclic diol residue is all diol residues. A polyester resin containing 10 mol% or more and 40 mol% or less in the component.   The polyester resin composition according to claim 1, wherein the polyester resin (A) has a glass transition temperature of 60 ° C. or more and 80 ° C. or less.   The polyester resin composition according to claim 1 or 2, wherein the alicyclic dicarboxylic acid residue is a 1,4-cyclohexanedicarboxylic acid residue.   The polyester resin composition according to any one of claims 1 to 3, wherein the aliphatic diol residue is a 1,4-butanediol residue.   The polyester resin composition according to any one of claims 1 to 4, wherein the polyester resin (B) further contains a polyether residue component.   The polyester resin composition according to any one of claims 1 to 5, wherein the alicyclic diol residue is a 1,4-cyclohexanedimethanol residue.   The heat-shrinkage rate in the main shrinkage direction when the polyester-based resin composition according to any one of claims 1 to 6 is stretched in at least a uniaxial direction and immersed in warm water at 80 ° C for 10 seconds is 40% or more. A polyester-based heat-shrinkable film.   The difference between the heat shrinkage rate in the main shrinkage direction when immersed in warm water at 80 ° C for 10 seconds and the heat shrinkage rate in the main shrinkage direction when immersed in warm water at 70 ° C for 10 seconds is 25% or less. 8. A polyester heat-shrinkable film according to 7.   A polyester heat-shrinkable multilayer film having at least one layer of the polyester heat-shrinkable film according to claim 7 or 8.   A heat-shrinkable label using the polyester-based heat-shrinkable film according to claim 7 or 8, or the polyester-based heat-shrinkable multilayer film according to claim 9.   A container equipped with the heat-shrinkable label according to claim 10.