JPH0160418B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention comprises a layer made of thermoplastic polyester;
The present invention relates to a laminate having excellent interlayer adhesion and containing adjacent layers made of a polymer containing hydroxyl groups and/or carboxyl groups in the molecule. More specifically, one or more elements selected from the group consisting of Al, Cr, Sn, Ge, and Si are added to the dicarboxylic acid component 100%.
A layer made of thermoplastic polyester containing 0.1 to 5 moles per mole, and a layer containing hydroxyl groups and/or
Alternatively, the present invention relates to a laminate including a layer made of a polymer containing a carboxyl group adjacent to each other. Polyester, represented by polyethylene terephthalate (hereinafter abbreviated as PET), is used not only as fibers and films but also as food containers and food packaging films due to its excellent mechanical properties, transparency, heat resistance, electrical properties, etc. Demand is also increasing. By the way, when polyester is used as a food container or food packaging film, it itself has a certain degree of gas barrier property and is preferable for food preservation, but depending on the food to be filled or enclosed. Furthermore, improvements in gas barrier properties are required. Therefore, in order to improve gas barrier properties, we created containers and films with multilayer structures in which polyester is laminated with ethylene-vinyl alcohol copolymer (hereinafter abbreviated as EVAL), which has the best gas barrier properties among synthetic resins. Attempts are being made. However, polyester
Adhesion with EVAL was extremely poor, and delamination easily occurred, making it unsuitable for practical use.
Therefore, polyester and EVAL are usually bonded together using an adhesive such as carboxylic acid-modified polyolefin, but even if such an adhesive is used,
Adhesive strength is not sufficient. Therefore, the current situation is that there is a strong demand for improved adhesion with EVAL or adhesives when manufacturing such multilayer molded products. The present inventors investigated various modifications of polyester for the purpose of improving the adhesion between EVAL or its adhesive and polyester, and found that Al, Cr, Sn,
It has been discovered that a polyester containing 0.1 to 5 moles of one or more elements selected from the group consisting of Ge and Si, per 100 moles of the dicarboxylic acid component, can achieve the above object, and the present invention has been achieved. did. The polyester forming one layer of the laminate of the present invention must contain one or more elements selected from the group consisting of Al, Cr, Sn, Ge, and Si. Among these, Al and Cr are preferred because they provide a high adhesive strength, and Al is particularly preferred. The content of these elements is suitably in the range of 0.1 to 5 moles per 100 moles of the dicarboxylic acid component constituting the polyester. If the content is less than 0.1 mol, the effect will not be sufficiently expressed, and if the content is more than 5 mol, undesirable phenomena such as gelation and coloring of the polymer will occur. It is preferable for these elements to exist chemically bonded to the polyester molecules rather than as a mere mixture with the polyester because higher adhesive strength can be obtained. As a method for bonding the above-mentioned elements to the polyester molecule, a method of adding a compound of the above-mentioned element (particularly preferably a metal ester, a chelate compound, an organic acid salt, etc.) during polymerization of the polyester and carrying out the polymerization can be mentioned. Specifically, examples of such compounds include aluminum acetylacetonate, aluminum ethoxide, aluminum propoxide, and reaction products of these compounds and monocarboxylic acids, and examples of Cr compounds include Chromium acetylacetonate or monocarboxylate of chromium, tetraethyl stanate, tetrapropylstanate, tetrabutyl stanate or the reaction product of these with monocarboxylic acid as the Sn compound, germanium dioxide as the Ge compound. Examples of the Si compound include methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, and diphenyldimethoxysilane. These compounds should be added to the polyester polymerization reaction system after the esterification reaction between the dicarboxylic acid and the diol has progressed and the carboxyl group content in the reaction system has decreased to a trace amount, or after the transesterification between the dicarboxylic acid ester and the diol. After the reaction is almost complete, the temperature
It is preferable to add it to the reaction system under conditions of 230°C or lower. Especially when using transesterification,
Since the above compound may deactivate the transesterification catalyst, it is preferable to add it after the transesterification reaction is completed. It is preferable to add it by dissolving it in a diol. When the above compound is used alone, the polymer may gel during polymerization, but in such a case, gelation can be prevented by using an appropriate amount of a monocarboxylic acid or its ester. The monocarboxylic acid or its ester is suitably added at the time of charging the polyester raw material or before the esterification reaction or transesterification reaction. Furthermore, when employing transesterification, it may be carried out immediately after the transesterification. For the esterification reaction between a dicarboxylic acid and a diol or the transesterification reaction between a dicarboxylic acid ester and a diol, and the subsequent polymerization reaction, conditions normally employed for polymerization of polyester can be employed. The polyester obtained in this way has
One or more elements selected from the group consisting of Al, Cr, Sn, Ge, and Si are bonded in the molecular chain or at the ends. The bond between the polyester and these elements is an alkoxide bond with the diol component or a carboxylate bond with the dicarboxylic acid component. That is, if the above element is represented by M, M and polyester are M-O-D-O... (In the formula, D represents a divalent group obtained by removing the hydroxyl group from a diol) or (In the formula, R ₁ represents a divalent group obtained by removing a carboxyl group from a dicarboxylic acid.) These points will be described in more detail below using Al as an example. The Al compound preferably used is a compound having the following structure. (Here, R ₂ represents a monovalent group obtained by removing the carboxyl group from an aromatic, aliphatic, or alicyclic monocarboxylic acid. R ₃ represents a monovalent group obtained by removing the carboxyl group from an aromatic, aliphatic, or alicyclic monocarboxylic acid. In addition, R ₄ represents a methyl group or a phenyl group, and R ₅ represents a methyl group, a phenyl group, or a monovalent group obtained by removing the proton of the hydroxyl group of an aliphatic alcohol. i,
j and k indicate the average value of each group bonded to Al, i+j+k=3 and 0≦
i≦2, 0≦j≦3, and 0≦k≦3. ) This aluminum compound is added to the polyester polymerization reaction system and at the same time, R ₃ -O- group and

[Formula] Most of the group parts react and bond with the dicarboxylic acid or diol component, and the alcohol R ₃ OH or β diketone or keto acid R ₅ COCH ₂ COR ₄ corresponding to these groups is eliminated to form a distillate. Move inside. Also, R ₂ COO−
When the group has a large number of carbon atoms in R ₂ (approximately 5 or more),
A part of it remains bonded to Al in the polyester, and the rest undergoes an exchange reaction with dicarboxylic acid, is eliminated, and is bonded to the end of the polyester molecule.
When R ₄ has carbon atoms of 4 or less, most of it becomes a monocarboxylic acid or its alkyl ester and migrates into the distillate. In this way, Al
is bonded within the polyester molecular chain or at the end of the molecular chain. Since most of the added amount of Al bonds with the polyester, the amount of the aluminum compound added is 0.1 per 100 moles of dicarboxylic acid.
A range of 5 moles is suitable. In addition, the monocarboxylic acid used to prevent gelation of the polymer is such that the total amount of the R ₂ COO− group in the aluminum compound and the monocarboxylic acid or its ester is based on the number of moles of Al. to 0.25~10
It is preferable to add it in molar amounts. The fact that Al-bonded polyester can be obtained by such a method can be confirmed from the facts described below. (1) R ₃ -O- group in aluminum compound and

The amount of the [Formula] group and the amount of R ₃ OH and R ₅ COCH ₂ COR ₄ detected in the distillate almost match. (2) As a result of trace analysis using a 400MHz ultra-high resolution NMR spectrum, when a monocarboxylic acid with 6 or more carbon atoms is used, R ₂ COO−
groups are present in the polyester, the amount of which corresponds to the total amount of R ₂ COO- groups and monocarboxylic acid or its ester in the added aluminum compound. (3) Fluorescence X-ray analysis shows that Al atoms are present in the polyester in an amount approximately equal to the amount added. (4) As a result of ET-IR spectrum analysis of polyester, 1600cm, which is not seen in ordinary polyester.
^-1 and 590cm ^-1 new absorptions are observed. The absorption of the former is, for example, Analytical Chemistry, No. 24.
Vol., p. 635 (1952), the absorption of carboxylic acid aluminum salts, and the latter absorption is e.g.
Related Vibrations”, Edward Armold (London), absorption of metal alkoxides. From the above results, the above-mentioned aluminum compounds undergo chemical changes during the polymerization reaction process, resulting in alkoxide bonds with diol components, dicarboxylic acid It is considered that the aluminum compound is converted into an aluminum compound having a carboxylate bond with the component and a carboxylate bond with the monocarboxylic acid component, and is incorporated into the polyester molecular chain or at the end.Constituting the polyester used in the present invention Examples of dicarboxylic acids include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, naphthalene dicarboxylic acid, diphenyl ether dicarboxylic acid, and diphenyl-4,4'-dicarboxylic acid, oxalic acid, malonic acid, succinic acid, and glutaric acid. , aliphatic dicarboxylic acids such as adipic acid, pimelic acid, corkic acid, azelaic acid, and sebacic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid.Also, as diols, ethylene glycol, 1,3 - aliphatic diols and cyclohexanediol such as propanediol, 1,4-butanediol, 1,5-bentanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol,
Examples include alicyclic diols such as cyclohexanedimethanol. In addition, in small amounts, dicarboxylic acids such as 5-sodium sulfoisophthalic acid, chlorterephthalic acid, bromiterephthalic acid, bromiisophthalic acid, chlornaphthalene dicarboxylic acid, bromonaphthalene dicarboxylic acid, polyethylene glycol, polytetramethylene glycol, neopentyl Glycols, diols such as 1,4-bis(β-hydroxyethoxy)benzene, 2,2′bis(P-β-hydroxyethoxyphenyl)propane, bis(P-β-hydroxyethoxyphenyl)sulfone, and trimerites Acid, trimesic acid, pyromellitic acid, glycerin, trimethylolpropane, pentaerythritol, hexanetriol-1,2,6, trimethylolethane, trimethylolhexane, trimethylolbenzene-1,3,5, tripropyrrolbenzene-1, Trivalent or higher carboxylic acids or alcohols such as 3,5, tributyolbenzene-1,3,5, and dimethylolpropionic acid can also be used. Although the intrinsic viscosity of the polyester is not particularly limited, it is preferably 0.5 dl/g or more. The intrinsic viscosity referred to herein is a value measured at 30°C in a mixed solvent of phenol/tetrachloroethane (1:1 weight ratio). The above-mentioned polyester has improved adhesion with a polymer containing a hydroxyl group and/or carboxyl group in the molecule compared to ordinary polyester, and can produce a laminate with excellent delamination resistance. . Polymers containing hydroxyl groups in their molecules include:
In addition to EVAL, examples include vinyl alcohol polymers and cellulose. Examples of polymers containing carboxyl groups include maleic anhydride-modified polyethylene, maleic anhydride-modified ethylene-vinyl acetate copolymer, styrene-maleic anhydride copolymer, ethylene-methacrylic acid copolymer, and ethylene-acrylic acid. Examples include olefinic polymers having pendant carboxyl groups or anhydrides thereof, such as acid copolymers. Furthermore, polyesters are also included in such polymers because they have a hydroxyl group or a carboxyl group at the end. In addition,
As can be seen from the above examples, the carboxyl group may be present as its anhydride or salt. The laminate of the present invention can be formed into a film or a film depending on the purpose.
It can take any shape such as sheet, plate, hollow, fiber, etc. More specific uses include food packaging films, sheets, trays, beverage bottles, infrared shielding films, sheets, and fibers. The laminate of the present invention is not only a two-layer structure in which the polyester layer A and the hydroxyl group- and/or carboxyl group-containing polymer layer B are laminated one layer at a time, but also
A/B/A, B/A/B 3-layer structure or 4
It also includes structures with more than one layer. Further, in addition to A and B, layers made of polyethylene, polypropylene, polyvinylidene chloride, nylon, metal, etc. may be further laminated. Furthermore, the laminate of the present invention may contain various additives such as pigments, dyes, antioxidants, ultraviolet stabilizers, and fillers in each layer. As a lamination method, a known method such as a coextrusion method, an extrusion lamination method, a dry lamination method, or a heat adhesion method can be used. The thickness of each layer is not particularly limited and depends on the purpose.
It can be made to have an arbitrary thickness of about 1 μm to 1 mm.
Furthermore, since it has excellent resistance to delamination, it can be subjected to treatments such as stretching and preheating forming after lamination. The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples. In addition, the melting point of the crystalline polyester in the reference example was determined by DSC (differential scanning calorimeter). That is, the peak temperature of the crystal melting peak when 5 mg of the rapidly cooled film was heated from room temperature at a rate of 20° C./min was defined as the melting point. In addition, the glass transition temperature of the amorphous polyester was also determined by DSC. The temperature increase rate is 20℃/
It's a minute. Reference example 1 [Preparation of aluminum compound] Nitrogen gas introduction pipe, stirrer, and cooling pipe were installed.
100 ml of hexylene glycol is placed in a 300 ml round bottom flask while passing nitrogen gas, and 0.10 mol of aluminum isopropoxide powder is added at room temperature and stirred. Next, add 0.05 mol of caprylic acid and 0.15 mol of P-oxybenzoic acid, and put it in an oil bath while stirring.
Raise the temperature to 100℃. Continue the reaction at this temperature for 15 minutes. Thereafter, 0.10 mol of acetylacetone was added, and the reaction was continued at 100°C for 15 minutes to prepare an aluminum compound. As a result of measuring the infrared absorption spectrum of this reaction solution, although a slight absorption of unreacted carboxylic acid was observed at 1700 cm ^-1 , the absorption of carboxylic acid aluminum salt at 1600 cm ^-1 and the absorption of acetylacetone complex salt at 1540 cm ^-1 appears strongly, indicating that the alcoholate bond has changed to a carboxylate and acetylacetone complex salt bond. [Polymerization] Attach a nitrogen gas introduction tube, stirrer, and cooling tube to a 300ml three-necked flask, and add dimethyl terephthalate.
100g, ethylene glycol 68g, zinc acetate 40mg
is added, heated to 200°C under a nitrogen gas stream, and reacted for 3 hours to perform transesterification. Subsequently, 25μ of tributyl phosphate and 40mg of antimony trioxide were added at 200°C, and the above aluminum compound solution was added in an amount of 0.52 mol per 100 mol of dimethyl terephthalate in terms of aluminum atoms, to the contents of the flask. After dissolving the aluminum compound solution, the temperature of the oil bath was raised to 260°C, and the pressure was gradually reduced to 280°C, and polymerization was proceeded for 90 minutes under a reduced pressure of 0.1 mmHg to obtain a pale green polymer. The intrinsic viscosity ([η]) of the obtained polyester is
It was 0.71 dl/g. The melting point was 252°C. The NMR spectrum of the obtained polyester is shown in FIG. Absorption of the methylene proton of caprylic acid at 0.90 ppm and the phenyl proton of P-oxybenzoic acid are observed at 6.65 ppm. The amount of caprylic acid present in the polymer determined from this spectrum was slightly smaller than the value calculated from the amount charged, but the amount of P-oxybenzoic acid present almost matched the amount charged. FIG. 2 shows the FT-IR spectrum of the obtained polyester. Weak absorption is observed at 1600 cm ^-1 and 590 cm ^-1 , but this absorption is not observed at all in the spectrum of polyethylene terephthalate shown in Figure 3. As explained in the text, the absorption at 1600 cm ^-1 is based on carboxylic acid aluminum salt, and the absorption at 590 cm ^-1 is based on aluminum alcoholate. Reference example 2 Attach a nitrogen gas introduction tube, stirrer, and cooling tube to a 300ml three-necked flask, and add dimethyl terephthalate.
Add 100 g of ethylene glycol, 68 g of ethylene glycol, 8.77 g of methyl benzoate, and 40 mg of zinc acetate, heat to 200° C. under a nitrogen gas stream, and react for 3 hours to perform a transesterification reaction. Subsequently, tributyl phosphate
Add 25μ and 40mg of antimony trioxide, add aluminum acetylacetonate to 0.50mol per 100mol of dimethyl terephthalate and dissolve, then raise the temperature of the oil bath to 260℃ and gradually reduce the pressure to 280℃. °C and under a reduced pressure of 0.1 mmHg
Polymerization was continued for 90 minutes to obtain a pale yellow polymer. [η] of the obtained polyester was 0.70 dl/g. Moreover, its melting point was 253°C. The FT-IR spectrum of the obtained polyester is shown in FIG. Absorption of aluminum carboxylate is observed at 1600 cm ^-1 and absorption of aluminum alcoholate is observed at 590 cm ^-1 . In addition, as a result of NMR spectrum analysis of the distillate distilled after the transesterification reaction of this polyester until the end of the polymerization, absorption derived from acetylacetone was observed, and as a result of quantitative analysis, it was found that the added aluminum acetylacetonate An amount approximately corresponding to that of acetylacetone was detected. The above indicates that aluminum acetylacetonate releases acetylacetone during the polymerization process and changes to aluminum carboxylate and alcoholate. Reference Example 3 [Preparation of aluminum compound] While passing nitrogen gas through the apparatus described in Reference Example 1,
Take 100 ml of hexylene glycol, add 0.10 mol of aluminum isopropoxide powder, and stir. Next, 0.05 mol of caprylic acid and 0.15 mol of P-oxybenzoic acid are added, and the mixture is placed in an oil bath with stirring and heated to 100°C. Keep at this temperature and react for 15 minutes. Next, 0.10 mol of ethyl acetoacetate was added, and the reaction was continued at 100°C for 15 minutes to prepare an aluminum compound. [Polymerization] In the same manner as in Reference Example 1, transesterification of dimethyl terephthalate and ethylene glycol was carried out, and 25μ of tributyl phosphate and antimony trioxide were added.
Add 40mg of the above aluminum compound solution to dimethyl terephthalate in terms of aluminum atoms.
Add aluminum in an amount of 0.52 mol to 100 mol, raise the temperature to 260°C, raise the temperature to 280°C while gradually reducing the pressure, and further reduce the pressure to 0.1 mmHg and polymerize for 90 minutes. I proceeded. The obtained polyester was pale yellow and contained no insoluble matter. [η] of the polyester was 0.76 dl/g. In addition, the melting point of this polyester is 251℃
It was hot. Reference example 4 Attach a nitrogen gas introduction tube, stirrer, and cooling tube to a 300ml three-necked flask, and add dimethyl terephthalate 70.
g, 30 g of dimethyl isophthalate, 68 g of ethylene glycol, and 40 mg of zinc acetate were added, and the transesterification reaction was carried out at 200° C. for 3 hours under a nitrogen gas stream.
Tributyl phosphate 25μ, antimony trioxide 40mg
was added, and the aluminum compound solution prepared in Example 1 was added so that the amount of aluminum added was 0.52 mol in terms of aluminum atoms per 100 mol of the total of dimethyl terephthalate and dimethyl isophthalate. Polymerization was carried out in the same manner. The obtained polymer was a pale yellow-green transparent glassy polymer. Glass transition temperature measurement by DSC revealed that Tg was approximately 65°C. Moreover, [η] of this polyester was 0.72 dl/g. Reference example 5 A 300ml round bottom flask with a nitrogen gas introduction tube, a stirrer,
Attach the cooling pipe, 97g of dimethyl terephthalate,
Methyl benzoate 8.50g, ethylene glycol 57.4
g, 1,4-cyclohexanedimethanol 25.2
g, add 40 mg of zinc acetate, and add 200 mg of zinc acetate under a nitrogen gas stream.
The mixture was heated to ℃ and the transesterification reaction proceeded for 3 hours.
Tributyl phosphate 25μ, antimony trioxide 40
mg, 1.0g aluminum acetylacetonate
In addition, the temperature was raised to 260°C, the pressure was reduced to 280°C, the pressure was further reduced to approximately 0.1 mmHg, and polymerization was proceeded for 90 minutes. The obtained polymer was a pale green glassy polymer, and [η] was 0.68 dl/g. DSC
The measured glass transition temperature was 78°C. Reference Example 6 To a polymerization apparatus similar to Reference Example 1, add 100 g of dimethyl terephthalate, 100 g of 1,4-butanediol, and an n-hexane solution of tetrabutyl titanate so that the amount of tetrabutyl titanate is 40 mg.
Transesterification reactions were carried out at 180°C for 1 hour, at 200°C for 1 hour, and at 220°C for 1 hour. Next, the aluminum compound solution used in Example 1 was added so that the amount of aluminum added was 0.2 mol per 100 mol of dimethyl terephthalate, the temperature was raised to 260°C, the pressure was gradually reduced to 270°C, and the pressure was further reduced. The polymerization was carried out for 90 minutes at a pressure of about 0.1 mmHg. The obtained polyester was a pale yellow crystalline polyester with a melting point of 221°C. Also, [η] is
It was 0.73 dl/g. Reference Example 7 64.0 g of bis-β-hydroxyethyl terephthalate, 25.0 g of succinic anhydride, 15.5 g of ethylene glycol, and 14.9 g of diethylene glycol were placed in the reaction apparatus described in Reference Example 1, and the mixture was heated to 200 g under a nitrogen gas stream.
℃ and reacted for 1 hour, then heated to 215℃ and reacted for 1 hour.
Allow time to react. Add 25μ of tributyl phosphate and 36mg of antimony trioxide, add the aluminum compound solution used in Reference Example 1 so that aluminum atoms are 0.50mol per 100mol of dicarboxylic acid component, and heat to 260℃ while reducing pressure. 275℃,
Polymerization was carried out for 90 minutes under reduced pressure of about 0.1 mmHg. The obtained polyester was a hard rubber-like transparent light yellow polymer at room temperature, and had [η]=0.64 dl/g. Reference Example 8 In a polymerization apparatus similar to Reference Example 1, 6 g of bis-β-hydroxyethyl terephthalate and 36.5 g of adipic acid were added.
g, 15.5 g of ethylene glycol, and 14.9 g of diethylene glycol were added, and the esterification reaction was allowed to proceed at 200° C. for 5 hours under a nitrogen gas stream. Add 25μ of tributyl phosphate and 36mg of antimony trioxide, add the aluminum compound solution used in Reference Example 1 so that the number of moles of aluminum atoms is 0.5 moles per 100 moles of the dicarboxylic acid component, and raise the temperature to 260 ° C. The temperature was reduced to 280°C, and polymerization was carried out for 1 hour under a vacuum of about 0.1 mmHg. The obtained polyester was orange in color and hard rubber-like. [η]=
It was 0.59 dl/g. Reference Example 9 In the polymerization apparatus used in Reference Example 1, 48.5 g of dimethyl terephthalate, 57.6 g of dimethyl sebacate, 8.77 g of methyl benzoate, 49.1 g of ethylene glycol,
Add 32.6 g of diethylene glycol and 40 mg of zinc acetate, heat to 200°C under a nitrogen gas stream, and perform transesterification for 3 hours. Then tributyl phosphate
Add 25μ, 40mg of antimony trioxide, and 1.0g of aluminum acetylacetate, and raise the temperature to 260℃.
The pressure was gradually reduced to 275°C, and polymerization was allowed to proceed for 120 minutes under a reduced pressure of about 0.1 mmHg. The obtained polyester was translucent, soft rubber-like, and had a light green color. [η]=0.56dl/g
It was hot. Example 1 Polyester obtained in Reference Examples 1 to 5 and a normal polyester containing no aluminum compound as a comparative example
PET ([η] = 0.70) was heated using a heat press to a thickness of approx.
It was molded into a 200μ quenched film. In addition, sufficiently dried ethylene-vinyl alcohol copolymer (EVAL E manufactured by Kuraray, hereinafter abbreviated as EVAL)
A 100μ film was made from the chip. The two films were stacked and crimped at 180°C with a pressure of 10 kg/cm ² , then kept at 280°C for 2 minutes under almost no load to melt and bond both polymers, and then lightly sandwiched in a cooling press to quickly cool and cover. A sheet was produced. A rectangular specimen with a width of 15 mm was cut from this sheet, and after being left at room temperature overnight, a peel test was conducted at room temperature using an Instron universal testing machine at a tensile speed of 20 mm/min. The results are shown in Table 1. The Al-containing polyesters obtained in Reference Examples 1 to 5 have peel strength at the melt-bonded interface with EVAL that is 10 to 40 times higher than that of ordinary PET.

[Table] Example 2 Multilayer films were produced using the Al-containing polyesters obtained in Reference Examples 7, 8, and 9 and, for comparison, polyesters polymerized with the same monomer composition without adding an aluminum compound. That is, on a biaxially stretched PET film (thickness 100μ), the above-mentioned polyester was molded at 180°C to a thickness of about 100μ, a 100μ film of EVAL was placed on top of this, and the polyester was molded at 180°C for 2 hours.
A three-layer film was prepared by melt-pressing (pressure: 5 kg/cm ² ) for minutes and rapidly cooling. A specimen with a width of 15 mm was cut from this film, and a T-peel test was conducted at room temperature at a tensile speed of 200 mm/min. The results are shown in Table 2.

[Table] Example 3 Various aluminum compounds were prepared in the same manner as the method for preparing aluminum compounds described in Reference Example 1, using 0.05 mol of various monocarboxylic acids shown in Table 3 instead of caprylic acid. This aluminum compound solution was added to 100 moles of dimethyl terephthalate in an amount of 0.52 moles in terms of aluminum atoms using the polymerization method described in Reference Example 1, and the resulting polyester was treated with the polymerization method described in Example 1. A bonded sheet with EVAL was prepared and its peel strength was measured. The results are shown in Table 3. Table 3 Interlayer peel strength of polyester/EVAL bonded sheet

[Table] Example 4 A 300ml three-necked flask was equipped with a nitrogen gas inlet tube, a stirrer, and a cooling tube, and 100g of dimethyl terephthalate, 68g of ethylene glycol, and 40mg of zinc acetate were added, and the mixture was heated to 200°C under a stream of nitrogen gas. ,
A transesterification reaction was carried out by reacting for 3 hours. Subsequently, at 200℃, add 25μ of tributyl phosphate and 40mg of antimony trioxide, and then add and dissolve the specified amount of the compounds shown in Table 4, and then lower the oil bath temperature.
Raise the temperature to 260℃ and gradually reduce the pressure to 280℃
Polyester was obtained by proceeding with polymerization for 90 minutes under reduced pressure of 0.1 mmHg. Table 4 shows the intrinsic viscosity of the obtained polyester. Furthermore, a multilayer sheet of polyester and EVAL was prepared from the obtained polyester according to the method described in Example 1, and a peel test was conducted. The results are shown in Table 4. All of the polyesters of the examples have improved interlayer adhesion with EVAL compared to the PET of the comparative example.

[Table] Example 5 Polyesters obtained in Reference Examples 1 to 5 and ordinary polyesters containing no aluminum compound as comparative examples.
PET ([η] = 0.70 dl/g) was formed into a quenched film with a thickness of about 200 μm using a hot press. Further, from sufficiently dried carboxylic acid modified polyethylene and carboxylic acid modified ethylene-vinyl acetate copolymer chips, a quenched film of about 200μ was produced using a hot press. A polyester film and a carboxylic acid-modified polyethylene film or a carboxylic acid-modified ethylene-vinyl acetate copolymer film were stacked together and pressed together at 180°C with a pressure of 10 kg/cm ² , and then kept at 280°C for 2 minutes under almost no load to separate both polymers. After melting and bonding, it is quickly cooled by lightly sandwiching it in a cooling press.
A multilayer sheet was produced. A rectangular specimen with a width of 15 mm was cut out from this sheet and left at room temperature overnight.
A peel test was conducted at room temperature using an Instron universal testing machine at a tensile speed of 20 mm/min. Table 5 shows the results.
Shown below.

[Table] All measured values marked with an asterisk (*) were associated with fracture of the carboxylic acid modified polymer layer, and were determined from the load at the time of fracture.

[Brief explanation of drawings]

Figure 1 shows the polyester obtained in Reference Example 1.
This is an NMR spectrum. Also, Figure 2 shows reference example 1.
FIG. 3 shows the FT-IR spectrum of the polyester obtained in Example 2, FIG. 3 shows the polyethylene terephthalate, and FIG. 4 shows the FT-IR spectrum of the polyester obtained in Reference Example 2.

Claims (1)

[Claims] 1. A layer made of thermoplastic polyester containing 0.1 to 5 moles of one or more elements selected from the group consisting of Al, Cr, Sn, Ge, and Si per 100 moles of the dicarboxylic acid component. and a layer made of a polymer containing a hydroxyl group and/or a carboxyl group in the molecule, adjacent to each other. 2. Claim 1 in which one or more elements selected from the group consisting of Al, Cr, Sn, Ge, and Si are contained in a state bonded to the polyester molecular chain.
Laminate as described in section. 3. The laminate according to claim 1, wherein the polymer containing hydroxyl groups in the molecule is an ethylene-vinyl alcohol copolymer. 4. The laminate according to claim 1, wherein the polymer containing carboxyl groups in the molecule is an olefinic polymer having pendant carboxyl groups or anhydride groups thereof.