JPH0564645B2 - - Google Patents

Description

[Detailed description of the invention]

"Industrial Application Field" The present invention relates to a method for producing a laminated sheet having a polyester film as a base material, which can be used as a substrate for an electric circuit, an insulator for electric wires, a decorative material, or the like. "Prior Art" Polyester film has poor adhesive properties, and when a synthetic resin layer is provided on its surface, the surface of the polyester film is treated with corona discharge treatment, ultraviolet irradiation treatment, plasma treatment, or flame treatment to strengthen the bond between the two. After treatment and activation, a method of coating with a synthetic resin coating or the like has been adopted. Also,
In order to bond polyester films to each other or to bond polyester films to vinyl chloride resin films, methods such as applying an emulsion type or solution type adhesive and then bonding the films together have been adopted. However, the degree of activation of the surface activated using the former method decreases over time, so a coating film must be formed immediately after the activation treatment, and the The adhesive strength obtained was not necessarily satisfactory. Laminating films using the latter method has the disadvantages of limited machinery and the need for special adhesives, as well as the need to remove the medium in which the adhesive has been emulsified or dissolved, and is environmentally friendly. There were also some disadvantages. Furthermore, as another method for increasing the adhesion of polyester films, a so-called etching method has been proposed in which the surface of the polyester film is swollen or partially dissolved with various agents. It is based on the principle that the film is immersed in chemicals such as aqueous solution, trichloroacetic acid, and phenols to relax the crystal orientation near the film surface and at the same time reduce cohesiveness and increase the ability to accept and adhere to the binder resin. Although adhesive properties can be obtained, some of these chemicals are harmful and may be dangerous to handle.
This method has disadvantages in that the chemical gas is released into the atmosphere, causing environmental pollution, and it is necessary to take extreme precautions to prevent this problem. "Problem to be Solved by the Invention" The inventors of the present invention have been intensively studying methods for manufacturing various laminated sheets of polyester film that do not have the above-mentioned drawbacks, and have previously filed an application (Japanese Patent Application No. 181196-1981). By applying a plastisol composition containing a diisocyanate polymer block used in the method of laminating fiber knitted fabrics or nonwoven fabrics and other laminated materials as an adhesive to polyester films with smooth surfaces, the polyester films can be easily bonded together. The present inventors have discovered that it can be bonded to a material, and have completed the present invention. That is, an object of the present invention is to provide a lamination method for strongly adhering polyester films to each other or to a polyester film and a vinyl chloride resin film. "Means for Solving the Problems" Therefore, the gist of the present invention is to provide a method for laminating a polyester film and another polyester film or a vinyl chloride resin film, in which: (a) diisocyanate is added onto the polyester film; (b) heating and melting the plastisol composition at a temperature below the block body dissociation temperature; (c) applying the plastisol composition containing the polymer block; (d) heating the plastisol composition to a temperature equal to or higher than the dissociation temperature of the block body immediately before or after stacking another polyester film or vinyl chloride resin film on the surface; The present invention relates to a method for producing a laminated sheet, which comprises a step of heating and pressurizing a vinyl chloride resin film. To explain the present invention in detail, the vinyl chloride polymer, which is the main component of the plastisol composition used in the present invention, contains vinyl chloride or a mixture of vinyl chloride and a comonomer copolymerizable therewith with an emulsifier and a water-soluble polymer. Paste resin with a particle size of 5 μ or less, preferably about 0.05 to 3 μ, produced by emulsion polymerization in the presence of a polymerization initiator, or vinyl chloride or vinyl chloride and co-produced in the presence of a dispersant and an oil-soluble polymerization initiator. A paste resin or a resin for mixing paste resins produced by a fine suspension polymerization method in which all or a portion of a mixture with a polymerizable comonomer is mechanically finely dispersed and then polymerized. In addition, the viscosity of paste sol is
They may be used together as long as they do not adversely affect fluidity, processability, etc. Examples of comonomers that can be copolymerized with vinyl chloride include vinyl acetate,
Vinyl esters such as vinyl propionate and vinyl laurate; acrylic esters such as methyl acrylate, ethyl acrylate, and butyl acrylate; methacrylic esters such as methyl methacrylate and ethyl methacrylate; and maleic acids such as dibutyl maleate and diethyl maleate. Acid esters, fumaric acid esters such as dibutyl fumarate and diethyl fumarate, vinyl ethers such as vinyl methyl ether, vinyl butyl ether, and vinyl octyl ether, vinyl cyanides such as acrylonitrile and methacrylonitrile, ethylene, propylene, and styrene. Examples include α-olefins such as vinylidene chloride, vinylidene chloride, vinyl halides other than vinyl chloride such as vinyl bromide, and vinyl halides, and one or more of these types is 30% by weight or less, preferably 20% by weight or less. used in Vinyl chloride polymers are often polymerized using emulsifiers containing alkali metal salts, but due to the adhesive properties of plastisol compositions, the alkali metal content in vinyl chloride polymers is
It is desirable to select and use an emulsifier so that the concentration is 600 ppm or less. Emulsifiers that produce vinyl chloride polymers with low alkali metal content include:
Examples include ammonium salts and alkali metal salts of fatty acids whose alkyl group has 8 to 18 carbon atoms. Of course, the emulsifier is not limited to those mentioned above. Plasticizers, which are one component of plastisol compositions, are
There are no particular restrictions on what can be used as a vinyl chloride polymer, but for example, phthalic acid di-
n-Butyl (DBP), di-n-octyl phthalate, di-2-ethylhexyl phthalate (DOP), diisooctyl phthalate, octyldecyl phthalate, diisodecyl phthalate, benzyl butyl phthalate, di-2-ethylhexyl isophthalate Phthalic acid plasticizers such as di-2-ethylhexyl adipate (DOA), di-n-decyl adipate, diisodecyl adipate, di-2-ethylhexyl azelaate, dibutyl sebacate, di-2-ethylhexyl sebacate fatty acid ester plasticizers such as tributyl phosphate, tri-2-ethylhexyl phosphate, 2-ethylhexyldiphenyl phosphate, tricresyl phosphate, epoxidized soybean oil, epoxidized tall oil Examples include epoxy plasticizers such as fatty acid-2-ethylhexyl, and these may be used alone or in combination of two or more. The smaller the amount of plasticizer used, the better the adhesion, but it should be selected appropriately depending on the desired solid content concentration and fluidity of the paste sol, the performance of the laminated sheet to be obtained, the use of the laminated sheet, etc. and per 100 parts by weight of vinyl chloride polymer.
It ranges from 30 to 400 parts by weight, preferably from 50 to 200 parts by weight. In particular, when considering the adhesion and fluidity of plastisol, it is appropriate that the amount is in the range of 40 to 100 parts by weight. In addition, a part of the plasticizer can be replaced with a diluent such as mineral spirits, texanol isobutyrate, dodecylbenzene, or an organic solvent that swells the vinyl chloride polymer such as toluene or xylene. It may also be made into an organosol.
The amount of diluent and organic solvent to be added is appropriately determined depending on the intended use, but by using the diluent and organic solvent, the amount of plasticizer to be used can be reduced. The plastisol composition contains a block of diisocyanate polymer, preferably a long chain alkyl phenol block of diisocyanate polymer or oxybenzoic acid, to impart adhesive properties to the plastisol composition and for use as an adhesive. Contains an ester block as one of its components. The average molecular weight of the diisocyanate polymer block is 1000 to 10000.
It is preferable to use one within the range of . If the average degree of polymerization of the block is less than 1,000, the anchoring effect as an adhesive cannot be sufficiently exhibited and the adhesive strength is insufficient.On the other hand, if it is greater than 10,000, the viscosity of the sol composition will significantly increase, which is preferable. do not have. Therefore, the diisocyanate (monomer) constituting the diisocyanate polymer is, for example, fatty acid diisocyanate such as hexamethylene diisocyanate or lysine diisocyanate, or alicyclic diisocyanate such as hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, or hydrogenated tolylene diisocyanate. , tolylene diisocyanate, diphenylmethane diisocyanate, naphthylene diisocyanate, xylene diisocyanate, and other aromatic diisocyanates.
Among these, aromatic diisocyanates, particularly tolylene diisocyanate and diphenylmethane diisocyanate are preferred. The diisocyanate polymer can then be prepared in an inactivating solution such as ethyl acetate, methyl acetate, butyl acetate, methyl ethyl ketone, dioxane, chlorobenzene or in a plasticizer such as phthalate, phosphate, adipate or trimellistate. , obtained by polymerization using known catalysts such as tertiary amines, alkali metals and alcoholates of Mannitz base fatty acids, etc., and then blocking agents such as long-chain alkyl phenols and oxybenzoic acid esters. A blocking reaction is carried out to produce a long chain alkyl phenol block or oxybenzoic acid ester block of the diisocyanate polymer.
When a polymerization reaction or a blocking reaction is carried out in a highly volatile solvent, it is desirable to finally perform a solvent substitution treatment with a suitable high-boiling point solvent, such as a plasticizer. As the diisocyanate polymer used in the present invention, it is particularly preferable to use one containing an isocyanurate ring obtained by polymerizing diisocyanate monomers. Those containing isocyanurate rings are produced according to the method described above. Of course, the diisocyanate polymer may also be a so-called isocyanate group-terminated polyurethane, polyurea, etc., which are obtained by the reaction of an isocyanate and an active hydrogen compound. The alkylphenol used as a blocking agent is a phenol having an alkyl group having 4 or more carbon atoms as a substituent, and examples thereof include butylphenol, hexylphenol, octylphenol, nonylphenol, etc. As the benbenzoitsquaside ester, o-oxybenzoitsquaside ester, m
-oxybenzoitic acid ester and p-oxybenzoitic acid ester, among which p-substituted ones are particularly preferred. One of the groups constituting the oxybenzoitic acid ester is, for example, a long-chain alkyl group such as an n-heptyl group, n-octyl group, 2-ethylhexyl group, nonyl group, or dodecyl group in the case of m- and p-substituted products;
An alkoxyalkyl group having a long-chain polyoxyethylene group or polyoxypropylene group bonded thereto, or an alkoxyalkyl group having an oxyethylene group or oxypropylene group bonded to a long-chain alkyl group is preferred. In addition, in the case of an o-substituted group, a methyl group, an ethyl group, an isopropyl group, an isoamyl group,
n-butyl group, isobutyl group, sec-butyl group,
Alkyl groups such as n-heptyl group, n-octyl group, 2-ethylhexyl group, nonyl group, dodecyl group, alkoxyalkyl group bonded to (poly)oxyethylene or (poly)oxypropylene group, phenyl group, benzyl group, etc. The following aryl groups are mentioned. Furthermore, the blocking agent is not limited to those mentioned above, and other blocking agents such as lactams may also be used. The appropriate amount of the blocking agent to be used is approximately equivalent to the free isocyanate groups of the diisocyanate polymer. The amount of the blocked diisocyanate polymer added is 1 to 100 parts by weight of the vinyl chloride polymer.
A range of 25 parts by weight is preferred, and it is desirable that the effective NCO in the plastisol composition be present in a range of 0.03 to 1%, preferably 0.03 to 0.6%, especially 0.05 to 0.5%. For example, when using a 33% by weight dibutyl phthalate diluted solution of oxybenzoic acid ester blocked diisocyanate polymer after polymerization and blocking in dibutyl phthalate, vinyl chloride polymer
A plastisol composition is prepared by using 2 to 50 parts by weight per 100 parts by weight, and if the amount of plasticizer is insufficient, the deficiency is supplemented. Furthermore, the content of effective NCO in the diluted solution of 33% by weight dibutyl phthalate also differs, so the desired plastisol composition
Adjust the diluent appropriately and add to achieve the NCO content. If the effective NCO is less than 0.03% by weight, the adhesion effect will be small; conversely, if it is more than 1% by weight, undesirable phenomena such as increased sol viscosity and coloring will likely occur, and the adhesion will be impaired due to moisture absorption and rapid adhesive reaction. The phenomenon of bubble generation at the interface was observed,
This tends to cause a decrease in adhesive strength. The plastisol composition used in the present invention preferably contains an adhesion promoter, such as an accelerator for disassociating the blocks of the oxybenzoic acid ester blocked diisocyanate polymer. Examples of the dissociation promoter include inorganic or organic compounds of alkali metals, and inorganic or organic compounds of metals such as lead, tin, cadmium, and zinc, and it is desirable to use at least one of these. Examples of the alkali metal compound include fatty acids, especially fatty acids whose alkyl group has 8 to 18 carbon atoms, alkyl sulfuric acids, alkyl sulfonic acids, or potassium salts of polyoxyethylene adducts thereof;
Examples include sodium salts, and further potassium-zinc type and sodium-zinc type composite stabilizers. Metal compounds other than alkali metals include inorganic metal compounds such as lead white, basic lead silicate, tribasic lead sulfate, tribasic lead phosphite, silica gel co-precipitated lead silicate, zinc white, and lauric acid. , stearic acid, ricinoleic acid, naphthenic acid, salicylic acid,
Examples include organic compounds such as metal salts of cadmium, barium, calcium, zinc, lead, tin or magnesium such as 2-ethylhexoic acid fatty acid or resin, as well as zinc octylate, dibutyltin laurate, dioctyltin malate, dibutyltin merca. Examples include petide. Furthermore, organic acid liquid composite stabilizers such as calcium-zinc, barium-zinc, magnesium-zinc, and cadmium-barium-zinc stabilizers, which are usually commercially available as stabilizers for vinyl chloride resins, can be used. In the case of an alkali metal compound, the dissociation promoter is preferably contained in the plastisol composition in an amount of 600 ppm or less based on the vinyl chloride polymer. If the emulsifier used in the production of vinyl chloride polymer already contains alkali metal, the content of alkali metal should be added up as the alkali metal amount.
It is preferable to add an appropriate amount of an alkali metal compound dissociation promoter. Alkali metal content
If it exceeds 600 ppm, the viscosity stability during sol preparation or the obtained sol, as well as the adhesive reaction, will be inhibited and processability will be significantly deteriorated, and the adhesive strength will tend to decrease. When a metal compound other than an alkali metal is used as a dissociation promoter, it may act as a stabilizer, and the amount added is not particularly limited.
Usually 0.5 to 100 parts by weight of vinyl chloride polymer
10 parts by weight, preferably 1 to 5 parts by weight can achieve that purpose. Furthermore, when an alkali metal compound and a metal compound such as lead, tin, cadmium, or zinc are used together, the adhesive strength is synergistically improved. To produce a plastisol composition, a vinyl chloride polymer, a plasticizer, an adhesion promoter, and if necessary a dissociation accelerator and other additives are uniformly mixed. In the present invention, a vinyl chloride polymer that is completely sealed and stored immediately after production is used, and a vacuum defoaming process is performed during plastisol production before adding an adhesion agent. After the addition, it is preferable to perform stirring and mixing after the gas phase is degassed under vacuum or replaced with an inert gas such as nitrogen. Plastisol compositions are usually preferably gelatinized at 100 to 250°C; for example, in the case of a mixture of nonylphenol blocks of TDI trimer, the dissociation temperature of the blocks is in the range of 165 to 175°C; The dissociation temperature of the oxybenzoic acid ester block may be at least 150°C, and as compared to the former, the dissociation temperature is lower and the range of use is wider. When producing a composition, the introduction of moisture into the composition should be avoided as much as possible, and specifically, relative humidity should be avoided.
It is desirable to prepare in an atmosphere of 80% or less. Generally, when mixed in an atmosphere with a relative humidity of 80% or more, the sol will absorb at least a trace amount of water of 0.2% by weight or more. The polyester film used for the laminated sheet of the method of the present invention has a wall thickness of 10 to 300μ, preferably
It is desirable to use a material in the range of 30 to 200μ, especially 50 to 150μ. On the other hand, after applying the plastisol composition to this polyester film, another polyester film to be superimposed on the surface of the plastisol composition may be of the same type and thickness as the above-mentioned polyester film, and may be made of vinyl chloride. The resin film used is a semi-rigid or soft film of vinyl chloride resin whose main component is vinyl chloride obtained from a vinyl chloride homopolymer or a copolymer of vinyl chloride and a monomer that can be copolymerized. Ru. The vinyl chloride resin may be produced by any polymerization method such as suspension polymerization, emulsion polymerization, or bulk polymerization. In addition, polyester film or vinyl chloride resin film can be processed by extrusion molding, inflation molding, calendar processing,
Manufactured by casting. In order to manufacture a laminated sheet by the method of the present invention, for example, it is manufactured through the following steps. (a) A plastisol composition containing a diisocyanate polymer block is applied onto a polyester film by, for example, reverse roll, knife coater, spray, curtain flow, dip coating, rotary screen, flat screen, flexo, gravure printing, etc. The plastisol composition is applied to a coating thickness of 1 to 1000 μm, preferably 10 to 200 μm using various coating methods, and (b) the applied plastisol composition is heated and melted at a temperature below the block body dissociation temperature, and if necessary, once cooled and solidified. (c) Next, another polyester film or vinyl chloride resin film is placed on the surface coated with the plastisol composition. At this time, the plastisol composition may be heated to a temperature equal to or higher than the dissociation temperature of the blocks before the films are stacked together, or heated to a temperature equal to or higher than the dissociation temperature of the blocks after the films are stacked. good.
Furthermore, the method of overlapping the films may be such that the formed films are simply overlapped, or the polyester resin or the vinyl chloride resin may be extruded into a film form from an extruder or the like. (d) The laminated polyester film and other polyester film or vinyl chloride resin film are manufactured through the process of applying pressure under heat as described above. "Effects of the Invention" According to the method of the present invention, the NCO of the diisocyanate polymer added to the plastisol composition for coating on polyester film is blocked, so the plastisol composition can be prepared in a relatively hot and humid atmosphere. It can also be applied to polyester film. After coating on a polyester film, stacking another polyester film or vinyl chloride resin film on top of each other, the films are cross-linked by NCO and firmly bonded by heating and pressurizing the film to a temperature higher than the temperature at which the block body dissociates. . Furthermore, even if the plastisol composition is applied to a polyester film, heated and melted at a temperature below the dissociation temperature of the block, cooled and solidified, and stored as a composite sheet, the adhesion of the composite sheet may be impaired. Moreover, since the blocking agent does not dissociate under low-temperature heating below 130°C,
Various or complicated lamination processing methods can be employed using this composite sheet. Furthermore, it is possible to check the quality of the laminated sheet of the present invention at the manufacturing process stage, and damage caused by defects in the final product can be minimized. It can also be used as a method for manufacturing flat cables, etc. by sandwiching bare wires or strip-shaped conductors between films before laminating other polyester films or vinyl chloride resin films in the process of manufacturing a laminated sheet. "Examples" Next, the method of the present invention will be explained in detail with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded. In addition, the viscosity of the plastisol composition and the peel strength of the composite sheet or laminated sheet in Examples were measured as follows. (1) Sol viscosity measurement Using Tokyo Keiki B8H type viscometer, sol temperature
Sol viscosity was measured at 5 r.pm at 23°C. The sol used for the daily sol viscosity measurement was stirred gently for 1 minute using a stirring rod 2 hours before the measurement. (2) Peel strength (a) T-type peel strength The obtained composite sheet or laminated sheet is
After leaving it in a constant temperature and humidity room at 23℃ and 50% relative humidity for 1 day, cut it into 1-inch pieces, peeled off one end of the specimen, and stretched it in the length direction at 180℃ at a speed of 50mm/min.
A mold peel test was conducted and the average peel strength (unit: Kg/inch) of 5 test pieces was shown. (b) Cross-cut test method After cross-cutting the plastisol composition layer (vinyl chloride resin film layer) of the composite sheet obtained in accordance with JIS C2107, cellophane tape was pasted underneath to prevent air bubbles from forming. death,
A 90° cellophane tape peel test was conducted in accordance with ASTA D2197. The peeling speed of cellophane tape is
The speed was set at 500mm/min. The number of peeled pieces out of 100 squares at 1 mm intervals is shown. Examples 1 and 2, Comparative Example 1 <Preparation method of plastisol composition> Vinyl chloride paste resin (average degree of polymerization 1450)
100 parts by weight DOP 60 Epoxy stabilizer (product name FEP-13, manufactured by Adeka Argus)
3 parts by weight Ba-Zn stabilizer and dissociation accelerator (product name AC303, manufactured by Adeka Argus) 3 Adhesive agent Appropriate amount Each of the above ingredients was placed in a constant temperature and humidity room at 23℃ and 50% HR atmosphere. After being left for several days, it was weighed and mixed in a constant temperature room according to the following procedure. An amount equivalent to 45 parts by weight of DOP, a paste resin, an epoxy stabilizer, and a stabilizer/dissociation promoter were put into a Hobart mixer, and after uniformly mixing and kneading, vacuum defoaming was performed once. Next, as an adhesion agent, 33% by weight of p-oxybenzoic acid-2-ethylhexyl ester block (average molecular weight 1300) of TDI trimer, DBP solution (Example 1) and TDI trimer. Nonylphenol block substance (average molecular weight 1182)
A 32% by weight DBP solution (Example 2) was added and mixed, the remainder of DOP was added and mixed uniformly, and vacuum defoaming was performed again to prepare a plastisol composition. <Manufacture of composite sheet> A 90μ thick polyethylene terephthalate film (hereinafter referred to as DET) was coated with the above-mentioned plastisol composition to a thickness of about 100μ, and after being placed in a hot air circulation oven at 150°C for 5 minutes, it was cooled and solidified. . The peel strength of this composite sheet was measured and shown in Table 1. A sol composition was prepared in the same manner as in Example 1 except that no adhesion imparting agent was added, and after producing a composite sheet, the peel strength was measured and is also listed in Table 1 as Comparative Example 1. <Manufacture of laminated sheet> (1) Laminated sheet A The two composite sheets described above were heated with the vinyl chloride resin layers (hereinafter referred to as PVC) facing each other at 160°C, 170°C and
After preheating at each temperature of 180° C. for 1 minute, using a press machine with a press plate interval of 0.25 mm, the pieces were pressed for 1 minute at the same temperature as the preheating temperature and a load of 250 kg/cm ² , and after cooling, they were taken out. The T-peel strength of the two polyester films on the front and back sides was measured, and the adhesion of the laminated sheet was visually evaluated, and the results are shown in Table 1. (2) Laminated sheet B The vinyl chloride resin layer of the above-mentioned composite sheet is
After preheating for 1 minute at each temperature of 170 and 180℃, immediately overlap a 90μ thick polyethylene terephthalate film and heat at the same temperature as the preheating temperature.
Pressure bonding was carried out for 1 minute under a load of 250 kg/cm ² , and the product was taken out after cooling. The T-peel strength of the two polyester films on the front and back sides was measured, and the adhesion was determined visually, and the results are shown in Table 1.

【table】

[Table] As is clear from Table 1, the plastisol composition used in the present invention has good adhesion to the polyester film, and furthermore, the plastisol composition used in the present invention has a temperature at which the block body can be sufficiently dissociated after laminating the polyester film or vinyl chloride resin film. It can be seen that even better adhesion is exhibited by increasing the adhesive strength to . Example 3 and Example 4 The plastisol compositions prepared in Example 1 and Example 2 were the same as in Example 1 and Example 2, respectively, except that the stabilizer and dissociation promoter was replaced with tribasic lead sulfate. Composite sheets and laminated sheets were produced in the same manner, and their peel strength and adhesion were measured and are listed in Table 2.

[Table] From the above results, it can be seen that by using a lead-based stabilizer and dissociation promoter, the dissociation temperature of the block body shifts to a lower temperature side, and the adhesion with the polyester film also improves. From the results in Tables 1 and 2, it is clear that if the temperature of the plastisol composition is below 150°C after coating it on the polyester film, most of the isocyanate polymer will remain blocked in the vinyl chloride resin film. Even if the composite sheet is stored for a long period of time, it can be easily and firmly bonded to other polyester films by increasing the bonding temperature during production of the laminated sheet. Examples 5 and 6, Comparative Example 2 The plastisol compositions prepared in Examples 1, 2, and Comparative Example 1 were applied to a thickness of about 100 μm on a polyethylene terephthalate film at 130° C., which is the temperature at which the blocks hardly dissociate. The composite sheet was placed in a hot air circulating oven for 1 minute and then cooled and solidified to produce a composite sheet. Using this sheet, press temperature was 130°C, 150°C or 170°C and laminated sheet A was prepared in the same manner as in Example 1.
And a laminated sheet B was obtained. The T-type and checkerboard peel strengths of these composite sheets and the T-type peel strengths of Laminated Sheet A and Laminated Sheet B were measured and shown in Table 3.

[Table] From the results in Table 3, the plastisol composition applied to a polyester film adheres to the polyester film when heated below the dissociation temperature of the isocyanate block contained therein, but the peel strength is extremely weak, and once it is After laminating films, etc., the sheets are heated and pressed at a temperature higher than the dissociation temperature of the blocks to ensure strong adhesion and can be used as a laminated sheet. In addition, the T-type peel strength for practical use is:
It is necessary that the weight is 0.2Kg/inch or more.

Claims (1)

[Scope of Claims] 1. A method for laminating a polyester film and another polyester film or a vinyl chloride resin film, which comprises the steps of: (a) applying a plastisol composition containing a diisocyanate polymer block onto the polyester film; (b) heating and melting the plastisol composition at a temperature below the block body dissociation temperature, and (c) immediately before overlaying another polyester film or vinyl chloride resin film on the surface coated with the plastisol composition. Alternatively, after stacking, the plastisol composition is heated to a temperature higher than the dissociation temperature of the block body, and (d) the polyester film and another polyester film or vinyl chloride resin film are heated and pressurized. Characteristic method for manufacturing laminated sheets. 2. The method for producing a laminated sheet according to claim 1, wherein the diisocyanate polymer block is a long chain alkyl phenol block or an oxybenzoic acid ester block of an aromatic diisocyanate polymer. 3. The method for producing a laminated sheet according to claim 1 or 2, wherein the diisocyanate polymer contains an isocyanurate ring. 4. The method for producing a laminated sheet according to claim 2, wherein the aromatic diisocyanate is tolylene diisocyanate or diphenylmethane diisocyanate. 5. The method for producing a laminated sheet according to claim 1, wherein the diisocyanate polymer block has an average molecular weight in the range of 1,000 to 10,000.