JPH0557892B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method for laminating polyester films that can be used for electrical circuit boards, wire insulation coatings, decorative materials, and 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
A method is adopted in which the material is activated by corona discharge treatment, ultraviolet irradiation treatment, plasma treatment, or flame treatment, and then coated with a synthetic resin coating or the like. In order to bond polyester films together, methods such as applying an emulsion-type or solution-type adhesive and then bonding the films together have been used.

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 adhesion force is
It wasn't necessarily satisfying. Laminating films using the latter method has the disadvantages of limited machinery, the need for special adhesives, the need to remove the medium in which the adhesive was emulsified or dissolved, and environmental concerns. There were also some inconveniences.

Furthermore, as another method for improving the adhesiveness of polyester film, a so-called etching method has been proposed in which the surface of polyester film is swollen or partially dissolved with various agents.
In this method, the surface of polyester film is exposed to acid.
It is based on the principle that the film is immersed in alkali, amine aqueous solution, trichloroacetic acid, and phenols to relax the crystal orientation near the film surface and at the same time reduce cohesiveness and improve the adhesion of binder resin. However, some of these chemicals are harmful, making them dangerous to handle, and causing environmental pollution by releasing gas from the chemicals into the atmosphere. There were disadvantageous issues such as the need for caution.

"Problems to be Solved by the Invention" The inventors of the present invention have conducted intensive studies on a method for firmly adhering polyester films to each other without causing the above-mentioned drawbacks, and have found that polyesters such as isocyanate groups can be used as a medium for adhering polyester films together. The present invention was completed based on the discovery that polyester films can be adhered to each other very easily and simply by employing a vinyl chloride plastisol composition containing an adhesion promoter that causes a crosslinking reaction with the film. I came to the point.

That is, an object of the present invention is to provide a method for laminating polyester films in which polyester films are strongly adhered to each other.

"Means for Solving the Problems" The gist of the present invention is as follows: (a) A polyester film that can be folded into two,
Vinyl chloride plastisol composition containing an adhesion promoter (hereinafter simply referred to as plastisol composition)
(b) a second step of heating and melting the applied plastisol composition and then cooling and solidifying it; (c) applying the plastisol composition of the polyester film in a symmetrical pattern with respect to the fold line of the film; A method for laminating a polyester film is characterized in that the method includes a third step of folding the folded surfaces in half and heating and pressurizing the folded surfaces in half.

To explain the present invention in detail, the polyester film that can be folded into two used in the method of the present invention has a wall thickness of 30 to 300μ, preferably 50 to 150μ.
It is desirable that the material be wide or long enough to be folded in half along the center line.

On the other hand, plastisol compositions applied to polyester films contain vinyl chloride polymers, plasticizers,
The stabilizer must contain an adhesion promoter that has adhesive properties to the polyester film. Vinyl chloride polymers are produced by emulsion polymerization of vinyl chloride or a mixture of vinyl chloride and a comonomer copolymerizable with it in the presence of an emulsifier and a water-soluble polymerization initiator, and have a particle size of 5μ.
Hereinafter, in the presence of a paste resin, preferably about 0.05 to 3 μm, or a dispersant and an oil-soluble polymerization initiator, the whole or a part of vinyl chloride or a mixture of vinyl chloride and a comonomer copolymerizable therewith is micronized mechanically. This is a paste resin or a resin for mixing paste resins manufactured by a fine suspension polymerization method in which the resin is dispersed and then polymerized. Furthermore, a vinyl chloride resin having a large particle size produced by ordinary suspension polymerization may be used in combination as long as it does not adversely affect the viscosity, fluidity, processability, etc. of the plastisol composition. Examples of comonomers that can be copolymerized with vinyl chloride include vinyl esters such as vinyl acetate, vinyl propionate, and vinyl laurate; acrylic esters such as methyl acrylate, ethyl acrylate, and butyl acrylate; and methyl methacrylate and ethyl methacrylate. Methacrylic acid esters, maleic esters such as dibutyl maleate and diethyl maleate, fumaric acid esters such as subbutyl fumarate and diethyl fumarate, vinyl ethers such as vinyl methyl ether, vinyl butyl ether and vinyl octyl ether, acrylonitrile , vinyl cyanides such as methacrylonitrile, α-olefins such as ethylene, propylene, and styrene, vinylidene halides other than vinyl chloride such as vinylidene chloride, and vinyl bromide, or vinyl halides. The content of at least one species is 30% by weight or less, preferably 20% by weight or less.

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 amount is 1000 ppm or less. Emulsifiers that produce vinyl chloride polymers with low alkali metal content include:
Examples include ammonium salts or 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),
Phthalic acid plasticizers such as diisooctyl phthalate, octyldecyl phthalate, diisodecyl phthalate, butylbenzyl phthalate (BBP), di-2-ethylhexyl isophthalate, di-2-adipate
Fatty acid ester plasticizers such as ethylhexyl (DOA), di-n-decyl adipate, diisodecyl adipate, di-2-ethylhexyl azelate, dibutyl sebacate, di-2-ethylhexyl sebacate, tributyl phosphate, phosphoric acid Tory
Examples include phosphate ester plasticizers such as 2-ethylhexyl, 2-ethylhexyl diphenyl phosphate, and tricresyl phosphate; epoxy plasticizers such as epoxidized soybean oil and epoxidized tall oil fatty acid-2-ethylhexyl; One or two of these
Use a mixture of more than one species. The amount of plasticizer used is
The lower the number, the better the adhesion.However, the value should be selected appropriately depending on the desired solid content concentration and fluidity of the plastisol composition, the performance of the laminated sheet to be obtained, the use of the laminated sheet, etc. Combine 100
30 to 400 parts by weight, preferably 50 to 400 parts by weight
In the range of 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 the amount of plasticizer used can be reduced by using the diluent and organic solvent.

The plastisol composition contains an adhesion promoter so that a strong adhesive force can be obtained between the polyester film and the vinyl chloride resin obtained by gelling the plastisol composition. The adhesion promoter is preferably one that has reactivity to chemically bond with the polyester film in the composition, such as polyisocyanate compounds, polyisocyanate polymers, blocks of these compounds or polymers, polyamino Amide compounds, epoxy compounds, acrylic compounds, diallyl compounds, etc. are used, and among these, polyisocyanate compounds having isocyanate groups, polyisocyanate polymers, and blocks of these isocyanate groups are particularly preferred.

Examples of polyisocyanate compounds include fatty acid diisocyanates such as hexamethylene diisocyanate and lysine diisocyanate, alicyclic diisocyanates such as hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, and hydrogenated tolylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and naphthyl diisocyanate. Examples include aromatic diisocyanates such as diisocyanate and xylene diisocyanate.
Among these, aromatic diisocyanates, particularly tolylene diisocyanate and diphenylmethane diisocyanate are preferred. Polyisocyanate polymers can also be prepared by adding the above-mentioned polyisocyanate compounds, for example, in an inactivated solution such as ethyl acetate, methyl acetate, butyl acetate, methyl ethyl ketone, dioxane, chlorobenzene, or phthalate ester, phosphate ester, adipate ester. Alternatively, it can be obtained by polymerization by a known method in a plasticizer such as trimellitic acid ester using a known catalyst such as a tertiary amine, an alkali metal or alcoholate of Mannich's basic fatty acid.

As the polyisocyanate polymer used in the present invention, it is preferable to use one containing an isocyanurate ring obtained by polymerizing a polyisocyanate compound. Those containing isocyanurate rings are produced according to the method described above. Of course,
As the polyisocyanate polymer, it is also possible to use polyurethane, polyurea, etc., which are obtained by the reaction of polyisocyanate and an active hydrogen compound, and have so-called isocyanate group terminals.

Sequestering agents, or blocking agents, used to prevent the low temperature reactivity of isocyanate groups are
Examples include long-chain alkylphenols, oxybenzoic acid esters, and lactams.
Of course, it is not limited to these. The appropriate amount of the blocking agent to be used is approximately equivalent to the amount of free isocyanate groups. Blocking of isocyanate groups can be easily carried out in the above-mentioned medium, and polyisocyanate blocks and polyisocyanate polymer blocks can be obtained. For example, it is preferable to use a diisocyanate polymer block having an average molecular weight in the range of 1,000 to 10,000. If the average molecular weight of the block body is less than 1000, 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 10000, the viscosity of the sol composition will increase significantly, so it is preferable. do not have.

The amount of adhesion promoter added is based on the vinyl chloride polymer.
It is preferably in the range of 1 to 25 parts by weight per 100 parts by weight that the effective NCO in the plastisol composition is
It is desirable to be present in the range 0.01 to 1% by weight, preferably 0.03 to 0.6% by weight, especially 0.05 to 0.5% by weight. For example, 33% by weight of oxybenzoic acid esterified diisocyanate polymer after polymerization and blocking in dibutyl phthalate.
- When dibutyl phthalate diluted solution is used, a plastisol composition is prepared by using 1 to 50 parts by weight per 100 parts by weight of vinyl chloride polymer, and if the amount of plasticizer is insufficient, the deficiency is supplemented. Furthermore, since the content of effective NCO in the diluted solution of 33% by weight dibutyl phthalate also differs, the diluted solution is appropriately adjusted and added so as to obtain the desired NCO content of the plastisol composition. If the effective NCO is less than 0.03% by weight, the adhesion effect will be small, and 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 is observed, which tends to cause a decrease in adhesive strength. Commercially available polyaminoamide compounds,
For example, product names Oiltech 505, Oiltech 506
(manufactured by Schering), as an epoxy compound,
Similarly, under the trade name Epicote 828 (manufactured by Ciel Chemical Co., Ltd.), trimethylolpropane trimethacrylate is used as the acrylic compound along with a slight amount of peroxide, and diallyl phthalate is used as the diallyl compound. These adhesion promoters are used in appropriate amounts in consideration of their adhesive properties with the polyester film.

Plastisol compositions are typically mixed with stabilizers used in vinyl chloride resins. Many of these stabilizers generally act as dissociation promoters of isocyanate block bodies.

Stabilizers include lead white, basic lead silicate, tribasic lead sulfate, tribasic lead phosphite, silica gel co-precipitated lead silicate, inorganic metal compounds such as zinc white, lauric acid, stearic acid, and ricinol. Examples include organic compounds such as metal salts of cadmium, barium, calcium, zinc, lead, tin or magnesium, such as naphthenic acid, salicylic acid, 2-ethylhexoic acid fatty acids or resin acids, as well as zinc octylate, dibutyltin laurate. , dioctyltin malate, dibutyltin mercaptide, and the like. In addition, calcium-zinc type, barium-zinc type, magnesium-zinc type, cadmium-zinc type, which are usually commercially available as stabilizers for vinyl chloride resin.
Organic acid liquid composite stabilizers such as barium-zinc type stabilizers can also be used. Although the amount added is not particularly limited, it is usually 0.5 to 10 parts by weight, preferably 1 to 5 parts by weight, per 100 parts by weight of the vinyl chloride polymer.
The purpose can be achieved by parts by weight. Also, alkali metal compounds and lead, tin, cadmium,
When a metal compound such as zinc is used in combination, the adhesive strength increases synergistically.

To produce a plastisol composition, a vinyl chloride polymer, a plasticizer, an adhesion promoter, and, if necessary, a stabilizer, a colorant, other additives, etc. are uniformly mixed. For example, using a vinyl chloride polymer that has been completely sealed and stored immediately after production, a vacuum defoaming process is performed during plastisol production before adding an adhesion agent, and after the adhesion agent is added, It is preferable that the gas phase is degassed under vacuum or replaced with an inert gas such as nitrogen, and the stirring and mixing is performed.

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, if the sol is mixed in an atmosphere with a relative humidity of 80% or higher, at least 0.2% by weight or more of trace water will be absorbed into the sol, causing a decrease in adhesive properties.

In the method of the present invention, a plastisol composition is applied in a symmetrical pattern to the fold lines or lines to become the fold lines of a polyester film. For coating, various coating methods such as reverse roll, knife coater, spray, curtain flow, dip coating, rotary screen, flat screen, flexography, and gravure printing are employed. Although the coating thickness varies depending on the use of the laminated polyester film, it is generally desirable to be in the range of 1 to 1000 μm.
Practically, it is in the range of 10 to 200μ.

In order to heat and melt the plastisol composition applied to the polyester film, for example, use an infrared heater, a far-infrared heater, a high-frequency heater, a hot air circulation furnace, etc. to reach a temperature in the range of 90 to 250 °C,
For example, in the case of isocyanate block body, 150
The block is heated and melted at a temperature of 0.degree. Due to operational reasons, this is once cooled and solidified.

The polyester film with the vinyl chloride resin adhered to it obtained as described above is then folded in half along the fold line so that the vinyl chloride resin surface is on the inside, and heated to above the melting temperature of the vinyl chloride resin. A laminated polyester film is produced by applying pressure and melting and bonding the vinyl chloride resins together.

"Effects of the Invention" According to the method of the present invention, the interface between the polyester film and the vinyl chloride resin is strongly bonded by the cross-linked structure, and the vinyl chloride resin folded in half is compatible with each other, resulting in a strong laminated polyester sheet. is manufactured.

By coloring the plastisol composition and applying it in a geometric pattern at positions symmetrical to the polygonal lines, a decorative body having a colored and decorative pattern is obtained.

In addition, after placing a bare electric wire and a band-shaped conductor on the vinyl chloride resin surface of a polyester film coated with a plastisol composition and heated and melted into a gel,
By folding them together and heating and pressurizing them, it is possible to manufacture flat cables and undercarpet wires.

"Examples" Next, the method of the present invention will be explained in detail using Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

Example vinyl chloride paste resin (average degree of polymerization 1450)
65 parts by weight vinyl chloride blending resin (average degree of polymerization
1000) 35 〃 Butylbenzyl phthalate 40 〃 Epoxy stabilizer (product name FEP-13, manufactured by Adeka Argus) 3 〃 Stabilizer and dissociation accelerator (Ba-Zn type product name AC-303,
(Manufactured by Adeka Argus) 3 TDI trimer paraoxybenzoic acid-2-ethylhexyl ester block (average molecular weight 1300, dibutyl phthalate 33%)
Weight% solution) 15 〃 Anhydrous silica (trade name Aerosil #200, manufactured by Nippon Aerosil Co., Ltd.) 1 〃 Each of the above formulations was left in a constant temperature and humidity room at 23°C and 50% RH for several days, then weighed and kept at constant temperature. The mixture was put into a Hobart mixer in a room, mixed and stirred uniformly, and then subjected to vacuum defoaming to prepare a plastisol composition.

The plastisol composition was passed through an 80-mesh wire mesh screen (porosity about 80%), and
A single pattern approximately 100μ thick is repeatedly printed on a foldable polyethylene terephthalate film.
The mixture was heated and melted for 5 minutes in a hot air circulation oven maintained at 150°C, and after being taken out, it was cooled and solidified.

Next, a copper plate with a thickness of about 150μ is sandwiched in the unprinted area, the polyethylene terephthalate film is folded in two, and the above-mentioned solidified vinyl chloride resin printed patterns are pasted together so that they overlap, and both sides are exposed to far infrared rays at 200°C. heated above the glass transition temperature of the vinyl chloride resin layer, and applied a linear pressure of 100 kg/
After being crimped with a cm pressure roll, it was cooled and solidified to form a molded product.

The T-peel strength of the polyethylene terephthalate film and vinyl chloride resin interface of the molded product is 1 kg/
1 inch, and had sufficiently satisfactory performance as a flat cable.

The T-peel strength was measured as follows.

After leaving the manufactured flat cable in a constant temperature room at 23℃ and 50% relative humidity for one day, it was cut into 1-inch widths from the part without the steel plate, one end of the test piece was peeled off, and the test piece was cut in the length direction. At a pulling speed of 50mm/min
A 180°T-type peel test was conducted and the average peel strength of 5 test pieces was shown.

Claims (1)

[Claims] 1 (a) A vinyl chloride plastisol composition containing an adhesion promoter (hereinafter simply referred to as plastisol composition) is applied to a polyester film that can be folded in two in a symmetrical pattern with respect to the fold line of the film. (b) a second step of heating and melting the applied plastisol composition and then cooling and solidifying; (c) folding the polyester film in half with the plastisol composition-applied side facing inside; A method for laminating polyester films, which comprises a third step of applying heat and pressure.