JPS6247714B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyester laminated film having excellent physical properties and adhesive properties as a film, and in particular to printing inks; vacuum-deposited films such as aluminum or sputtering-deposited films; laminate materials made of polyethylene, polypropylene, etc.; Adhesion or lamination with polyvinylidene chloride coated films, ethylene vinyl alcohol copolymer films, polyvinyl alcohol films, etc., adhesion with photosensitive emulsions for photography and magnetic materials for magnetic tapes, and even aluminum foils. The present invention relates to a polyester laminated film that has excellent adhesion and lamination properties with other materials such as paper and paper. As is well known, polyester film (hereinafter referred to as PEST)
Film) exhibits stable properties over a wide temperature range of -60 to 150℃, and is strong and has excellent dimensional stability, oil resistance, chemical resistance, moisture resistance, transparency, and electrical insulation properties. It is also a sanitary and safe material. For this reason, magnetic tape, gold and silver thread, labels, photographic film, adhesive tape, packaging materials,
It is used in a wide range of applications, including various miscellaneous goods and electrical insulation materials. However, PEST film generally has poor adhesion to other materials and coatings, so it cannot be laminated or
When coating, printing, etc. are performed, a subbing layer (anchor coat) is provided on the processed surface of the PEST film in order to improve the adhesion with the materials.
Alternatively, it was necessary to physically or chemically modify the processed surface. Adhesives used as the undercoat layer include isocyanate-based, polyethyleneimine-based, and organic titanium-based adhesives, and physical and chemical modification methods include corona discharge treatment and copolymerization with monomers to strengthen bonding strength. Methods such as the legal method and the polymer blend method are known, but either method increases the number of processing steps and inevitably increases costs. Moreover, the physical properties of polyester are better as it is pure, and copolymerization, polymer blending, or addition of additives can improve the physical properties of the film, especially heat resistance, dimensional stability, etc.
Mechanical properties etc. deteriorate. Moreover, PEST films are often collected and reused, but depending on the type of coating film, the polymer often undergoes thermal deterioration or gels when melted and recycled. On the other hand, the present inventors have confirmed that the above-mentioned physical and chemical properties of PEST are closely correlated with the increase in density when heated at 150°C, as will be detailed later. It has been confirmed that the increase in density is 35×10 ^-3 g/cm ³ or more, although it exhibits particularly excellent physical and chemical properties as described above. However, such a large increase in density means that it is highly crystalline.
As mentioned above, since the problem of poor adhesion clearly appears, it is necessary to improve the adhesion by some method. The present inventors have focused on these circumstances and have conducted various studies in an attempt to improve the adhesiveness without impairing the original properties of highly crystalline PEST as described above. The present invention was completed as a result of such research, and its structure is as follows: (A) The density increases when heat treated at 150°C for 30 minutes.
At least one side of the base layer (A) made of highly crystalline PEST with a density of 35×10 ^-3 g/cm ³ or more, (B) the following (B-1) low crystalline copolymer PEST: 5
Copolymerization PEST of ~60% by weight and the same (B-2):
30% by weight or less (excluding 0), and the same (B-
3) Highly crystalline PEST: Surface layer consisting of a compound containing 10% by weight or more (B) (B-1) Density increase when heat treated at 150℃ for 30 minutes is 30×10 ^-3 g/cm ³ or less is a low crystalline copolymer
PEST, (B-2) Block copolymer PEST, (B-3) Highly crystalline with a density increase of 35×10 ^-3 g/cm ³ or more when heat treated at 150°C for 30 minutes
The main feature is that the surface layer (B) accounts for 1 to 70% by weight of the entire laminated film. In the present invention, the density increase during heat treatment is 35×
The highly crystalline PEST base layer (A) exhibiting 10 ^-3 g/cm ³ or more ensures the physical and chemical properties of the entire laminated film as well as the required properties such as heat resistance and dimensional stability, and also provides low crystallinity. Polymer copolymerization PEST (B-1), block copolymerization PEST (B-2) and high crystallinity
Adhesion is intended to be ensured by the surface layer (B) consisting of a specific ratio blend of PEST, and the greatest feature of the present invention lies in the structure of the surface layer (B). That is, in the present invention, the material constituting the surface layer (B) is
As mentioned above, low crystalline copolymer PEST (B-1) and block copolymer PEST have little density increase during heat treatment.
and highly crystalline PEST with large density increase during heat treatment.
The surface layer (B) has sufficient chemical resistance as a material constituting the surface layer of a laminated film and has excellent adhesive properties. . Therefore, by laminating this surface layer (B) on one or both sides of the base layer (A), which has excellent mechanical properties, it has the characteristics inherent to PEST film as described above, and also has excellent adhesive properties. An ideal laminated film can be obtained. Examples of dicarboxylic acids or condensation-polymerizable derivatives that can be used in the structure of the low-crystalline copolymerized PEST include terephthalic acid, isophthalic acid, 1,5-(or 2,6-
- or 2,7)-naphthalene dicarboxylic acid, 4,
4'-diphenylenedicarboxylic acid, bis(p-carboxyphenyl)methane, ethylene-bis-p-
Benzoic acid, 4,4'-diphenyloxycarboxylic acid, ethylene bis(p-oxybenzoic acid), 1,
Examples include 3-trimethylene-bis(p-oxybenzoic acid), 1,4-tetramethylene-bis(p-oxybenzoic acid), and 4,4'-sulfonyldibenzoic acid, and examples of the glycol include ethylene, Glycols such as 1,3-trimethylene, 1,4-tetramethylene, 1,6-hexamethylene, 1,8-octamethylene, 1,10 decamethylene,
Cyclohexane-1,4-diol, 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 2,2-dimethylthyl-1,3-propanediol, or Examples thereof include aralkylene glycols such as p-di-(hydroxymethyl)-benzene and p-di-(β-hydroxyethoxy)-benzene. In addition to the above, typical acids used to modify PEST include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and 1,4-cyclohexanecarboxylic acid. In addition to the above, examples include pentamethylene glycol, heptamethylene glycol, eicosamethylene glycol, nonane methylene glycol, dodecane methylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,3-propanediol,
Examples include 1,3-butanediol and 2,2,4-trimethylpentanediol, but the acid component and glycol component constituting the low-crystalline copolymer PEST are not limited to these. However, the most preferable PEST for achieving the purpose of the present invention uses terephthalic acid and ethylene glycol as main raw materials, and also contains acid components such as isophthalic acid, succinic acid, adipic acid, sebacic acid, and azelaic acid, as well as glycol components. Tetramethylene glycol, polytetramethylene glycol, diethylene glycol, 2,2-dimethyl-
Examples include copolymerized PEST containing 1,3-propanediol, propylene glycol, etc. as a third component. The amount of copolymerization of the third component should be 5 mol % or more, and if it is less than 5 mol %, the effect of further improving adhesiveness will not appear. Regarding the surface layer (B), as the blending ratio of the above-mentioned low-crystalline copolymer PEST increases, the adhesion improves, and the copolymer
Products containing 20% by weight or more of PEST exhibit heat-sealing properties by themselves. Next, block copolymerized PEST (B-2) refers to a block copolymer consisting of a highly crystalline segment component and a low crystalline segment component, and the highly crystalline segment component is the highly crystalline PEST (B-3) described below. ), and the low-crystalline segment components have good affinities with the low-crystalline copolymer PEST (B-1), so the block copolymer PEST ( By coexisting B-2), it becomes possible to obtain a surface layer (B) having both physical properties and adhesive properties. Typical examples of such block copolymer PEST include polyether/polyester elastomers, in which 7 to 95% by weight of the total segment components are polyether glycol or copolyether glycol, and these polyether glycols Alternatively, copolyether glycols in which the alkylene moiety is composed of an alkyl group having 2 to 12 carbon atoms or an aryl group having 4 to 10 carbon atoms (in other words, approximately 93 to 5% by weight consists of polyester segments) are optimal. This type of block copolymer, which belongs to the polymer class, usually has a melting point of 100°C or higher. Acid components used in the production of such polyether ester elastomers include terephthalic acid, isophthalic acid, phthalic acid, adipic acid, sebacic acid, succinic acid, azelaic acid, oxalic acid, dibenzoic acid, P, P' -methylene dibenzoic acid, 2,6-naphthalene dicarboxylic acid, etc., and glycol components include ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol,
Examples include 1,6-hexamethylene glycol, 1,4-cyclohexanedimethanol, diethylene glycol, 2,2-dimethyl-1,3-propanediol, butylene glycol, and pentamethylene glycol. Segment components constituting polyether ester include polyethers such as polyethylene oxide glycol, polypropylene oxide glycol, tetramethylene oxide glycol, copolymer glycol of ethylene oxide and propylene oxide, and copolymer glycol of ethylene oxide and tetrahydrofuran. , polyneopentyl azelate,
Aliphatic polyesters such as polyneopentyl adipate, polyneopentyl sebacate, poly-ε
- Reaction products of lactones such as caprolactone and polypivalolactone with polytetramethylene oxide glycol and polyethylene oxide glycol, etc. Incidentally, the adhesive properties of polymeric materials are generally considered to be affected by the type of surface functional groups of the polymer, surface irregularities, and crystallinity. However, when the present inventors conducted various studies on the factors that affect the adhesion of various copolymerized PESTs to printing inks, photosensitive emulsions, binders for magnetic tapes, various laminating materials, etc., they found that copolymerized PESTs with low crystallinity polymerization
It was confirmed that PEST exhibited superior adhesive properties, and that there was a high correlation between the increase in density when heated at 150°C and adhesive properties. In order to ensure adhesion that meets the purpose of the present invention, the increase in density of copolymerized PEST must be 30×10 ^-3 g/cm ³
Hereinafter, it has become clear that one should select one having a more preferably 20×10 ⁻³ g/cm ³ or less.
The increase in density varies significantly depending on the type and mole number of copolymer components in copolymerized PEST, so by adjusting these appropriately, copolymerization with a small increase in density can be achieved.
It is sufficient to obtain PEST, but in the case of PET (polyethylene terephthalate), which is obtained from terephthalic acid and ethylene glycol, which is the most typical PEST, the acid component is one of the effective copolymer components to reduce the density increase (Δρ). isophthalic acid is preferable, and as the glycol component, 2,2-dimethyl-1,3-propanediol, diethylene glycol, 1,4-cyclohexanedimethanol, propylene glycol, etc. are preferable, and 10 to 30 mol% of these are copolymerized. Copolymerization by
It is possible to reliably reduce the Δρ of PEST to 30×10 ⁻³ g/cm ³ or less. Among them, 2,2-
When 30 mol% of dimethyl-1,3-propanediol, diethylene glycol, 1,4-cyclohexane methanol, etc. is copolymerized, Δρ is 5×
10 ^-3 g/cm ³ or less, and the adhesiveness of copolymerized PEST is extremely excellent. By the way, a small amount of the above-mentioned block copolymer PEST is added to the low-crystalline copolymer PEST with a small density increase.
Those containing this compound exhibit extremely excellent adhesion, but
On the other hand, it is not suitable for use as a laminated material as it is because it has poor chemical resistance and solvent resistance, as well as poor scratch resistance and surface strength. However, these formulations contain an appropriate amount of highly crystalline
It has been found that adhesion can be improved by mixing PEST without substantially impairing chemical resistance or the like. That is, the surface layer (B) for improving adhesion, which is the most characteristic feature of the present invention, is a low-crystalline copolymer PEST (B-1) showing the above-mentioned density increase: 5 to 60.
weight % (more preferably 10 to 50 weight %), the block copolymer (B-2): 30 weight % or less (however, excluding 0) (more preferably 1 to 10 weight %), and the below-mentioned high Crystalline PEST: A film formed from a mixture containing 10% by weight or more (more preferably 40% by weight or more). If the amount of low-crystalline copolymer PEST (B-1) is less than 5% by weight, sufficient adhesion cannot be imparted to the surface layer (B). Moreover, the copolymerized PEST (B-1) has good transparency due to its low crystallinity, and has the effect of increasing the transparency of the laminated film and increasing its suitability as a packaging film, etc., but it is less than 5% by weight. However, these effects will be insufficient and it will not be possible to obtain satisfactory transparency. On the other hand, if it exceeds 60% by weight, the surface properties of the surface layer (B), ie, chemical resistance, solvent resistance, lubricity, scrubbing resistance, etc., deteriorate, making it unsuitable for practical use.
In particular, in the surface layer (B) where the amount of copolymerized PEST (B-1) is too large, methyl ethyl ketone, tetrahydrofuran, benzene, ethyl acetate, chloroform,
If the product is dipped or coated in a solvent such as trichlene, problems such as swelling and dissolution of the copolymerized PEST (B-1) will occur. Moreover, if erroneous characters or designs are written on such a film, a problem arises in that the ink or paint cannot be removed with an organic solvent. For this reason, in the present invention, the content of the low crystalline copolymer PEST (B-1) in the film (B) is set at 5 to 60% by weight. In addition, even when block copolymerized PEST (B-2) is not blended, the surface layer (B) exhibits considerable adhesion, but by blending an appropriate amount of PEST (B-2), the surface layer (B) has a The surface layer (B)
Its physical and chemical properties are also improved. As mentioned earlier, this is block copolymerization PEST (B-2)
Low crystallinity copolymerization PEST (B-1) due to the coexistence of
The affinity of highly crystalline PEST (B-3) with
This is thought to be due to improved homogeneity of the surface layer (B). However, the amount of the block copolymer PEST (B-2)
If it exceeds 30% by weight, the transparency of the surface layer (B) will decrease, as well as its chemical resistance and scratch resistance. Furthermore, the surface hardness will decrease and the surface layer will stretch when adhesive tape is applied and removed. Ripple-like wrinkles may appear. In addition, as mentioned above, highly crystalline PEST (B-3) has the original excellent characteristics of PEST.
In order to give the surface layer (B) appropriate physical and chemical properties and chemical and solvent resistance, it must be blended in an amount of 10% by weight or more. In this way, in the present invention, low crystalline copolymer PEST (B-1) and block copolymer PEST (B-1) are used as the material for the surface layer (B).
PEST (B-2) and highly crystalline PEST (B-3)
By using a mixture of these in an appropriate ratio, it is possible to obtain a surface layer (B) that has appropriate physical and chemical properties and excellent adhesiveness. Next, the highly crystalline PEST that constitutes the base layer (A) is obtained by condensation polymerization of dicarboxylic acid and glycol.
The dicarboxylic acids or condensation-polymerizable derivatives used in the production of PEST include terephthalic acid, isophthalic acid, 1,5-(or 2,
6- or 2,7-) naphthalene dicarboxylic acid,
4,4'-diphenylenedicarboxylic acid, bis(p-
carboxyphenyl)methane, ethylene-bis-
p-benzoic acid, 1,4-tetramethylene-bis-
p-benzoic acid, 4,4'-diphenyloxycarboxylic acid, ethylene-bis(p-oxybenzoic acid),
Examples include 1,3-trimethylene-bis(p-oxybenzoic acid), 1,4-tetramethylene-bis(p-oxybenzoic acid), and 4,4'-sulfonyldibenzoic acid. Glycol components include glycols such as ethylene, 1,3-trimethylene, 1,4-tetramethylene, 1,6-hexamethylene, 1,8-octamethylene, 1,10-decamethylene, and cyclohexane-1,4- Diol, 1,
4-cyclohexanedimethanol, 2,2,4,
Examples include 4-tetramethyl-1,3-cyclobutanediol, 2,2-dimethyl-1,3-propanediol, and further p-di(hydroxymethyl)benzene, p-di(β-hydroxyethoxy)benzene, etc. alkylene glycols can also be used. Among these, the most preferred PEST constituting the base layer (A) in the present invention are polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), but of course they are not limited to these, and will be described in detail below. It is also possible to copolymerize the third component or perform polymer blending within a range that does not impede the properties required for the base layer (A). Generally useful high molecular weight PEST resins have an intrinsic viscosity of 0.2 when measured at 25-30°C in o-chlorophenol, a 60/40 volume ratio phenol-tetrachloroethane mixture, or similar solvent systems.
dl/g or more, more preferably about 0.4 dl/g or more, and particularly preferred PET has an intrinsic viscosity of about 0.5
However, as a result of various experiments, in order to achieve the purpose of the present invention, the PEST constituting the base layer (A) has a density increase when heat treated at 150°C for 30 minutes. It has become clear that a highly crystalline PEST with a crystallinity of at least 35×10 ⁻³ g/cm ³ and more preferably at least 37×10 ⁻³ g/cm ³ should be selected. The increase in density of PET homopolymer with an intrinsic viscosity of 0.60 dl/g is 43×10 ^-3 g/cm ³ , and that of PET homopolymer with an intrinsic viscosity of 0.90 dl/g.
The density increase of PET homopolymer is 39×10 ⁻³ g/
cm ³ and all of them serve the purpose as materials for the base layer (A). PEST with large density increase like this
has high crystallinity, and oriented crystallization is significantly promoted by film formation, stretching, and heat setting. Therefore, by using it as a base film, it has high strength, mechanical properties, and dimensions. A laminated stretched film with excellent stability etc. can be obtained. However, if the density increase is less than 35×10 ^-3 g/cm ³ ,
The effects of improving various properties during film formation, stretching, and heat setting become insufficient, and the mechanical properties such as strength and dimensional stability of the finally obtained laminated film become insufficient. The constituent materials of the base layer (A) and surface layer (B) used in the present invention are as described above, but these may include stabilizers, antioxidants, coloring inhibitors, lubricants, fillers, and plasticizers as necessary. , thickeners, thinners, antifoaming agents, antistatic agents, pigments, and other various additives can be added. Also, the highly crystalline PEST used in the surface layer (B) is the base layer (A).
It may be the same as or different from the highly crystalline PEST that constitutes the PEST. In the present invention, the base layer (A) made of the above-mentioned highly crystalline PEST
The surface layer (B) is laminated on at least one side of the film by the method described below, stretched and heat-set to produce a PEST laminated film. Burr 1-70% by weight,
More preferably, the content should be 5 to 40% by weight. However, if the proportion of the surface layer (B) is less than 1% by weight, the thickness of the surface layer (B) as an adhesion improving layer is insufficient, and sufficient adhesion cannot be obtained.
On the other hand, if it exceeds 70% by weight, the base layer (A) as a reinforcing layer becomes too thin, resulting in poor heat resistance and mechanical properties of the laminated film. Even if the film is bent, the film may be deformed or broken. Next, a specific method for manufacturing a PEST laminated film will be described, but the present invention is not limited to the following method. The most preferable molding method for PEST laminated film is coextrusion, in which the base layer (A) and surface layer (B) are extruded from two or three extruders, respectively, and then laminated using a combining adapter or the like. PEST laminated film can be easily obtained by
In this case, the materials constituting the surface layer (B) may be melt-mixed in advance, or they may be extruded while being kneaded using a static mixer or the like. The shape of the die may be either flat or circular, and both extrudates may be laminated either inside or outside the die. As other lamination forming methods, an extrusion lamination method or a dry or wet lamination method may be employed, and in these cases, it is preferable to interpose a suitable adhesive on the lamination surface. In this case, the base layer (A) and the surface layer (B) may be formed by, for example, the T-die method or the inflation method. The form of the laminated film is the base layer.
A two-layer film with one layer each of (A) and surface layer (B),
The most common is a three-layer film with a surface layer (B) laminated on both sides of a base layer (A), but these other layers (A) and (B)
It is also possible to make a 10-layer film or a 20-layer film by laminating a plurality of each of them, and such multilayer films have even better pinhole resistance, impact resistance, etc. Incidentally, such a multilayer film can be manufactured according to the method described in, for example, "SPE Journal, June 1973, Vol. 29". The composition ratio of the base layer (A) and surface layer (B) can be adjusted by adjusting the discharge amount from each extruder when using a coextrusion method, or by adjusting the amount of output from each extruder when using a lamination method.
It can be easily adjusted by changing the thickness of (B) and (B). Although the PEST laminated film of the present invention may be in an unstretched state, the mechanical properties of the product film can be further improved by appropriately stretching the film before or after lamination. The stretching may be carried out according to a known method, but the most preferred stretching temperature is about 70 to 100°C. In addition, the preferred stretching ratio is 1.2 to 6 times, more preferably 1.2 to 6 times in the case of uniaxial stretching.
1.5 to 6 times, 1.2 to 6 times in the longitudinal direction in case of biaxial stretching
1.2 to 6 times in the horizontal direction. Furthermore, it is also possible to perform heat treatment, corona discharge treatment, etc. before and after lamination and stretching. The laminated film of the present invention thus obtained has excellent adhesiveness and transparency, as well as good dimensional stability, heat resistance, and surface properties, and is therefore extremely useful for packaging various foods. In particular, this laminated film does not lose its bonding strength with laminate materials (paper, polyethylene, polypropylene, aluminum foil, etc.) even after boiling or retort processing, so it is suitable for packaging materials such as cooked food packaging and boil-in bags. It is also useful as a packaging material for water products because of its good water resistance. Furthermore, it has extremely good adhesion with vinylidene chloride film, which has excellent gas barrier properties, making it useful as a packaging material for processed meat and seafood products such as hams and sausages, as well as foods that are susceptible to deterioration such as bonito flakes and miso. It's also expensive. In addition to its use as a food packaging material, its excellent mechanical properties can be used for general packaging, adhesive tape, planar heating elements, plate making, photographic film, tracing materials, etc. Can be used as a material for labels, various display boards, stamping foils, gold/silver thread, etc., or has excellent electrical properties (insulating properties).
It has a wide range of suitability as a material for covering electric wires, printed circuit boards, capacitors, magnetic tapes, magnetic cards, floppy disks, etc. Moreover, the layers (A) and (B) constituting the laminated film of the present invention are both polyester structures, and will not cause thermal deterioration or gelation even when used recovered materials are chipped and remelted. Therefore, it has the advantage that it can be recovered and reused, and if these characteristics are considered together, it can be provided economically at a sufficiently low cost. Next, the configuration and effects of the present invention will be explained in more detail with reference to Examples, and the methods of measuring and processing various physical properties employed in the experiments will be clarified to help with this. [Density increase: Δρ] Based on JIS K 7112, measure the density of the sample before and after heat treatment at 30°C using a (water-calcium nitrate) liquid density gradient tube, and use the difference as Δρ. . However, the heat treatment conditions are as follows. [Heat treatment] A substantially amorphous and unoriented sample was sandwiched between aluminum foil (0.05 mm thick) manufactured by Nippon Seiho Co., Ltd., and a hydraulic pressure gauge was measured using a hydraulic press (heat press) manufactured by Shindo Metal Industry Co., Ltd. Heat treated at 150°C for 30 minutes under a pressure of 10Kg/cm ² . [Haze value] Measured according to JIS K 6714 using a haze meter S type manufactured by Toyo Seiki Seisakusho. [Strength and elongation] Based on JIS K 2318, measured in an atmosphere of 20°C and 65% RH using a universal tensile testing machine "Tensilon UTM3" manufactured by Toyo Baldwin, and calculated as the average value in the longitudinal and transverse directions. demand. [Intrinsic viscosity and reduced specific viscosity of the polymer] Dissolve the polymer (80 mg) in a mixed solvent (20 c.c.) of phenol/tetrachloroethane = 3/2, and measure the viscosity at 30°C using an Ubbelohde capillary viscometer. Measure. The unit is dl/g. [Heat shrinkage rate] Based on JIS C 2318, heat treatment was performed at a temperature of 150°C for 1 hour, and the dimensional changes before and after the treatment were measured, and the average value in the vertical and horizontal directions was determined. [Chemical resistance of film] Mark B on the surface of the film (B) in black with Magic Ink No. 500 in a size of about 2 cm square. Then, after the ink has sufficiently dried, the characters written on the film surface are wiped off with gauze soaked in chloroform, and the surface condition is then observed. If the surface is smooth and glossy, mark it with an ○, and if the surface is rough and has lost its luster, mark it with an x. [Boiling treatment] The film is placed in a bag made of 50 mesh stainless steel wire mesh, immersed in boiling water, and boiled for 30 minutes. For films with a sealant laminated on the surface, paper is inserted between the films to prevent them from fusing together. [Retort processing] Dyeing processing machine “HUHT212/350” manufactured by Hisaka Seisakusho
The film was placed in a wire mesh bag similar to the one used in the boiling treatment above and placed in flowing hot water using a small-sized Obermeyer mold, and heat treated at 120°C for 30 minutes. For films with a sealant laminated on the surface, paper is inserted between the films to prevent them from fusing together. [Heat seal] High-speed automatic bag making machine "HS 400 model" manufactured by Seibu Kikai Co., Ltd.
The bags were heat-sealed at 170°C at a rate of 30 bags/min. Seal width is 11cm. [Heat-sealing strength] The heat-sealed film was cut into strips with a width of 15 mm, and the "Tensilon" was used to measure the strength and elongation.
Measure the seal strength by T-shaped peeling with UTM3 type. Peeling speed 200mm/min, measurement atmosphere 20℃, 65
%RH [Lamination strength] Polyethylene or polypropylene is extruded or dry laminated on the surface of a PEST laminated film, and this is cut into strips 15 mm wide and 20 cm long. If you make a cut in a part of the tip of this strip and stretch it, the sealing material will stretch and the PEST film and laminate layer will separate, so apply this peeled end to the same "Tensilon" as above and peel it off with a T-shaped peeling mold. Measure the laminate strength. Peeling speed 200
mm/min, atmosphere 20℃, 65%RH Experimental example 1 Terephthalic acid was used as the acid component, ethylene glycol was used as the glycol component, and 5 mol%, 10 mol%, and 20 mol% of the ethylene glycol were used.
and 30 mol % of 2,2-dimethyl-1,3-propanediol (NPG) were added to produce four types of low-crystalline copolymer PEST. The resulting copolymerization
The reduced specific viscosity of PEST is 0.82, 0.83, 0.85 and
It was 0.93. On the other hand, terephthalic acid is used as the acid component, and butanediol (BD) and polytetramethylene glycol (PTMG: molecular weight 1000) are used as the glycol components.
A polyether ester elastomer was produced using [BD/PTMG=85.7/14.3 (molar ratio)].
The reduced specific viscosity of this elastomer was 1.85. Predetermined amounts of the obtained low-crystalline copolymer PEST, elastomer, and high-crystalline PET pellets with an intrinsic viscosity of 0.60 were placed in a bag and mixed to form a material for the surface layer (B). On the other hand, the above-mentioned highly crystalline PET with an intrinsic viscosity of 0.60 was used as the material for the base layer (A). Two extruders were used for film formation, and the extrusion temperature was 280 to 290°C.
PET and the mixed pellets were supplied to the other extruder, and the pellets were coextruded into a film while being laminated in a T die, and then rapidly cooled to obtain a laminated film. At this time, adjust the extrusion amount of both materials to create a base layer (A) and a surface layer (B).
The thickness ratio of the laminated films was changed, but the thickness of the laminated films in the unstretched state was about 250 μm. This laminated film was stretched 3.5 times in the longitudinal direction (at a temperature of 85°C) using rolls with different circumferential speeds, then 3.7 times in the transverse direction (at a temperature of 105°C) using a tenter, and then stretched at 220°C in the transverse direction. The sample was heat-set while being relaxed by 5%, and the surface was further subjected to a corona discharge treatment. The thickness of the obtained laminated film was about 19 μm. Polyol and isocyanate-based adhesives ("Takerak A-971" manufactured by Takeda Pharmaceutical Co., Ltd. and "Takenate A3" manufactured by Takeda Pharmaceutical Co., Ltd.) were applied to the surface layer (B) side of the obtained laminated film.
(1 part dissolved in ethyl acetate to give a concentration of 30%) was coated on the surface with a gravure roll having a depth of 80 μm using 100 meshes. Then after pre-drying, 50
An unstretched polypropylene film (CP) having a thickness of 60 μm was laminated using a nipple roll at 40° C., and then aged at 40° C. for 2 days. The CP surfaces of each of the obtained CP laminate films were stacked and sealed with a heat sealer, and after subjecting this to boiling and retort processing, the laminated film and
The interlayer laminate strength with CP was measured. In addition, the strength of the heat-sealed portion of the untreated product was measured. The results are summarized in Table 1.

[Table] In Table 1, Comparative Example (1-1) is because the density increase of the low crystalline copolymer PEST blended in the surface layer (B) is too large and the polyether ester elastomer is not blended. , extremely poor adhesion. Furthermore, Comparative Example (1-2) does not contain a polyether ester elastomer, so the adhesive properties are also poor. On the other hand, in comparative example (1-3), the surface layer
Since the amount of low-crystalline copolymerized PEST of (B) is insufficient and the amount of polyether ester elastomer is too large, the adhesiveness is somewhat good, but the transparency is poor and the strength is weak. Comparative Examples (1-4) and (1-5) also had poor adhesion because the amount of low-crystalline polymerized PEST in the surface layer (B) was insufficient. Comparative Example (1-6) contains too much low-crystalline copolymer PEST in the surface layer (B), and has very good adhesion but very poor chemical resistance. It was easily damaged. In Comparative Example (1-7), the composition ratio of the surface layer (B) in the entire laminated film was too small, resulting in poor adhesion. Comparative example (1-8) is highly crystalline
This is a film made solely of PEST, and as a matter of course it has extremely poor adhesion. On the other hand, Examples (1-1) to (1-5) all satisfy the specified requirements of the present invention, and have extremely good adhesive properties and physical properties. Note that the laminated films of Examples had heat-sealing properties themselves, but Comparative Examples (1-1), (1-2), (1-3),
None of (1-4), (1-5), (1-7), and (1-8) had heat sealability. Experimental Example 2 Low crystalline copolymerization PEST using terephthalic acid as the acid component and methylene glycol and 3 mol%, 10 mol%, and 30 mol% of 1,4-cyclohexanedimethanol (CHDM) as the glycol component.
was manufactured. The reduced specific viscosities of each PEST obtained were 0.83, 0.85, and 1.05, respectively. On the other hand, a polyether ester elastomer was manufactured using terephthalic acid as the acid component and methylene glycol (EG) and polytetramethylene glycol (PTMG) as the glycol components. The molecular weight of PTMG used was 1000, and EG and
The molar ratio of PTMG was 87.7/12.3. The reduced specific viscosity of the obtained elastomer was 1.39. The obtained low-crystalline copolymer PEST, elastomer, and high-crystalline PET with an intrinsic viscosity of 0.60 were weighed into a bag in predetermined amounts and mixed to form the surface layer (B) material. Using the same highly crystalline PET as in Experimental Example 1, coextrusion, stretching, heat setting, corona discharge treatment, CP lamination, and aging were sequentially performed in the same manner as in Experimental Example 1 to obtain a CP laminate film. Each of the obtained films was boiled and retorted in the same manner as in Experimental Example 1, and the adhesive strength was measured, and the heat sealability was also examined. The results are shown in Table 2.

[Table] Table 2 shows comparative examples (2-1) and (2-
In 2), the density of the low-crystalline copolymerized PEST in the surface layer (B) increased too much, so both had poor adhesion. In Comparative Example (2-3), the amount of low-crystalline copolymer PEST in the surface layer (B) was too large, so although the adhesion was extremely good, the chemical resistance of the film was poor. It was easily scratched by rubbing with a chloroform-impregnated cloth. In Comparative Example (2-4), the composition ratio of the surface layer (B) in the entire laminated film was too large, and although the adhesion was good, the physical properties of the film were poor. Similar to Comparative Example (2-3), Comparative Example (2-5) contained a large amount of low-crystalline copolymer PEST, and had good adhesion but poor chemical resistance of the film. Comparative Examples (2-6) to (2-8) are examples in which the surface layer (B) does not contain low-crystalline copolymer PEST or polyether ester elastomer, and all have extremely poor adhesion. . Comparative example (2-8) is an example in which a combination of two types of highly crystalline PEST and polyether ester elastomer exceeding the specified amount was used as the surface layer (B), and the haze value was extremely high and transparency was lacking. I can see that it is something. Experimental Example 3 A low-crystalline copolymer PEST was produced by using terephthalic acid and isophthalic acid (IPA) together as the acid component and using ethylene glycol as the glycol component. The reduced specific viscosity of 5 mol % or 30 mol % copolymerized IPA was 0.82 or 0.85, respectively. On the other hand, a polyether ester elastomer was manufactured using terephthalic acid as the acid component and ethylene glycol (EG) and polyethylene glycol (PEG) as the glycol components. The molecular weight of PEG used was 8300, and EG and PEG
The molar ratio was 99.74/0.26. The reduced specific viscosity of the obtained elastomer was 0.74. This elastomer and the low crystallinity copolymer PEST
and a blend of highly crystalline PET with an intrinsic viscosity of 0.60.
(B) was used as the material, and highly crystalline PET with an intrinsic viscosity of 0.60 was used as the material for the base layer (A), and coextrusion was carried out in the same manner as in Experimental Example 1 to form an unstretched laminate with a thickness of approximately 250 μm. I got the film. This laminated film was subjected to simultaneous biaxial stretching at a stretching ratio of 4.0 x 4.0 times in the longitudinal and transverse directions at 90°C using a film stretcher manufactured by TM Long Co., Ltd., and then fixed in a metal frame at 220°C. It was heat-set at ℃ for 15 seconds, and the surface was further subjected to corona discharge treatment. Next, the same adhesive used in Experimental Example 1 was applied uniformly to the treated surface using a wire bar, and after pre-drying, the adhesive was applied to a thickness of 60 μm.
The unstretched PCs of 100 to 100°C were stacked, passed through a rubber press roll heated to 50°C to laminate, and then aged at 40°C for 2 days. Thereafter, the CP surfaces of each film were stacked and sealed with a heat sealer, and the physical properties and adhesion of the films were measured in the same manner as in Experimental Example 1. The results are shown in Table 3. Experimental example 4 Terephthalic acid was used as the acid component, and EG and propylene glycol (PG) were used as the glycol components.
or EG and 1,4-butanediol (1,4-
BD), using the same polyether ester elastomer and high crystalline PEST as in Experimental Example 3, and fabricating a CP laminate film in the same manner as in Experimental Example 3. was manufactured. The adhesiveness and physical properties of each film obtained are summarized in Table 3.

[Table] As is clear from Table 3, comparative example (3-
1), (4-1), and (4-2) all had poor adhesion because the density increase of the low-crystalline copolymer PEST in the surface layer (B) was too large. In addition, in Comparative Example (3-2), the surface layer (B)
Because the amount of low-crystalline copolymer PEST in the film is too large, the adhesive properties are good, but the physical properties of the film, especially the chemical resistance, are extremely poor. Examples (3-1), (3-2), and (4-) that meet the requirements of the present invention
Both of 1) have extremely good adhesive properties and film physical properties.

Claims (1)

[Scope of Claims] 1 (A) At least one side of a base layer made of highly crystalline polyester having a density increase of 35×10 ^-3 g/cm ³ or more when heat treated at 150°C for 30 minutes, (B) The following: (B-1) low crystalline copolyester: 5 to 60% by weight, (B-2) copolyester: 30% by weight or less (however, 0 is not included), and (B-3) high Surface layer consisting of a compound containing 10% by weight or more of crystalline polyester (B-1) A low-crystalline copolymer polyester whose density increase is 30×10 ^-3 g/cm ³ or less when heat-treated at 150°C for 30 minutes. , (B-2) block copolymerized polyester, and (B-3) highly crystalline polyester whose density increase is 35×10 ^-3 g/cm ³ or more when heat treated at 150°C for 30 minutes. A polyester laminated film, wherein the composition ratio of the surface layer (B) to the entire laminated film is 1 to 70% by weight.