JPS5854974B2 - Method for manufacturing polyethylene terephthalate and metal laminates - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a laminate in which various metals are tightly and firmly bonded to polyethylene terephthalate.

In recent years, with the development of the electronic equipment industry, various thermoplastic resins have been used as substrates for flexible printed wiring boards for wiring between parts, but the drawback is that they are difficult to adhere to metals.

Polyethylene terephthalate sheets or films have strong mechanical strength, dimensional stability, chemical resistance, and excellent electrical properties, but until now, their adhesiveness has been a problem, and the adhesive surface has been treated with a chromic acid mixture. Even after performing operations such as corona discharge treatment and flame treatment, sufficient adhesion was still not obtained.

Furthermore, the epoxy adhesives that are currently widely used as adhesives do not have sufficient adhesive strength, but also lack flexibility.

Further, even when existing polyester adhesives or polyvinyl butyral adhesives obtained from mixed acids such as terephthalic acid isophthalic acid and dihydric alcohols are used, it is difficult to obtain tight and strong adhesive strength.

Therefore, an object of the present invention is to provide a laminate in which a polyethylene terephthalate sheet or film that has not undergone any complicated surface treatment and a metal foil or sheet that has not undergone any other treatment are firmly adhered.

As a result of various studies, the inventors of the present invention coated a polyethylene terephthalate sheet or film with an ether-type modified polyester having strong adhesive strength, bonded a metal foil or sheet to this, and heat-sealed it to form a laminated mold. We have found that the above objective can be achieved by doing so.

The laminates of polyethylene terephthalate and various metals obtained by this method are extremely effective when used in flat cables, lightweight and flexible printed circuit laminates, and the like.

The specific ether-type modified polyester used in the present invention is disclosed in Japanese Patent Publication Nos. 43-20213 and 50-1
The synthesis method is described in detail in the specification of No. 05793, in which polyethylene terephthalate is heat-treated with one or more glycols other than ethylene glycol to exchange the ethylene glycol in polyethylene terephthalate with the glycol used. A series of synthesized copolyester compounds are available under the trade name "STAFIX" from Fuji Photo Film Co., Ltd.
It is commercially available as J.

To describe the method for producing this ether-type modified polyester in more detail, 10 to 80 parts of glycol such as diethylene glycol, triethylene glycol, and polyethylene glycol are added to 100 parts by weight of polyethylene terephthalate.
In addition to the parts by weight or a mixture thereof, neopentyl glycol, bispheno-A-ethylene oxide adduct,
Chains such as bisphenol A-propylene oxide adduct and the like.

Add 5 to 40 parts by weight of branched glyco → and gradually heat in a dry nitrogen stream until the glyco-MD boiling point or about 200 to
The transesterification reaction is carried out at 606C for 2 to 20 hours.

In this case, if a catalyst for the transesterification reaction such as a gold metal, an alkaline earth metal or a derivative thereof is added to the reaction mixture, the reaction proceeds advantageously, but it is not necessary to add it. When the transesterification reaction is carried out in this way, the ethylene glycol in the polyethylene terephthalate is exchanged with the glycols used, but the reaction system is then vacuumed at that temperature to remove the excess glycols and the ethylene glycol produced. It is necessary to completely remove glycols.

After the process of removing glycols is completed, an ether-type modified polyester having the desired adhesion or rubber-like elasticity is obtained, but its molecular weight is approximately 2.0
00 to 30.000 is appropriate.

To apply this ether-type modified polyester to a polyethylene terephthalate sheet or film soil, follow the steps below.
Two methods are used.

In the first method, an ether-type modified polyester is extruded into a film from an extruder at about 150 to 180°C and fused onto a polyethylene terephthalate film or sheet preheated to about 150°C.

Another method is to use ether-type modified polyester.
This is a method in which a laminate film is obtained by casting a 30% solution onto a polyethylene terephthalate film or sheet and drying it.

At this time, there is no limit to the thickness of the polyethylene terephthalate film or sheet, but the appropriate thickness of the ether-type modified polyester is about 30 to 400 microns.

When metal is sandwiched between polyethylene terephthalate films or sheets, the thickness of the adhesive layer must be appropriately selected from the above thickness range depending on the thickness, width, etc. of the metal foil or sheet. It is.

A major feature of the ether-type modified polyester used in the present invention is that it exhibits almost the same adhesive peel strength of about 13 to 25 ky/25 mm to both polyethylene terephthalate and metal adherends.

Therefore, the laminate obtained by thermal fusion has a uniform bonded area and is a much tighter, stronger, and more stable product than a laminate using conventional adhesives.

A reactive polyisocyanate, a blocked polyisocyanate, a crosslinking agent, a chain extender, etc. are further mixed into this ether-type modified polyester, or the surface coated with the ether-type modified polyester is coated and composited. It is possible to impart rigidity to the adhesive layer of the strongly bonded laminate, thereby increasing the adhesive shear strength and heat resistance.

Ether type modified polyester has about 35 to 20
Since it has 0 equivalents of 7106 g of hydroxyl groups, when a reactive polyisocyanate is applied to it, a crosslinking reaction occurs, the tensile modulus of the product increases, and the temperature at which it begins to flow upon heating increases.

Reactive polyisocyanates include incyanates having at least two isocyanate groups and blocked products thereof, such as aliphatic diisocyanates, aliphatic diisocyanates having cyclic groups, aromatic isocyanates,
These include naphthalene isocyanate, biphenyl isocyanate, diphenylmethane diisocyanate, triphenylmethane diisocyanate, triisocyanate, tetraisocyanate, and blocked products thereof.

Examples of these include ethaned diisocyanate, butane diisocyanate, hexane diisocyanate, 2,2-
Dimethylpentane diisocyanate, 2,2.4-trimethylpentane diisocyanate, decane diisocyanate, ω, ω'-diisocyanate 1--1,3-dimethylpenzole, ω, ω'-diisocyanate)-1,2-
Dimethylcyclohexane diisocyanate, ω, ω′-
Diisocyanate 1--1,4-diethylpenzole, ω
, ω'-diisocyanate 1--1.5-dimethylnaphthalene, ω, ω'-diisocyanate n-propylbiphenyl, 1,3-phenylene diisocyanate, 1-
Methylbenzo-2,4-diisocyanate, 1.3
-dimethylbenzo-2,6-diisocyanate, naphthalene-1,4 diisocyanate, ■, 1'-dinaphthyl-22'-diisocyanate, biphenyl-2,4
'-diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, diphenylmethane-4
, 4'-diisocyanate, 2,2'-dimethyldiphenyl, methane-4,4'-diisocyanate, 3,3'-
Dimethoxydiphenylmethane-4,4'-diisocyanate, 4,4'-jethoxydiphenylmethane-4,4
'-diisocyanate, tolylene diisocyanate, 1
Diisocyanates such as 5-naphthylene diisocyanate, 1-methylbenzo-2,4,6-triisocyanate, 1,3,5-trimethylbenzo-2,4
, 6-1-diisocyanate, diphenylmethane-2,
4,4'-triisocyanate, triphenylmethane-
Triisocyanates such as 4,4',4"-triisocyanate, dimers of these isocyanates, or
adducts of these isocyanates, or these isocyanates and 2
There are also adducts with polyvalent or trivalent polyalcohols.

These adducts include adducts of tolylene diisocyanate and trimethylolpropane, adducts with 3 moles of tolylene diisocyanate, adducts with 3 moles of hexamethylene diisocyanate, adducts with 2 moles of hexamethylene diisocyanate, etc. Adducts arbitrarily selected from isocyanates can also be used.

Among these, adducts of isocyanates and phenols are typical, such as Coronate AP 5table and Millionate MS- from Nippon Polyurethane Co., Ltd.
50, Desmodule AP 5tab from Bayer
It is commercially available under the trade name LE.

Coronate AP 5table is a polyisocyanate made by reacting 3 moles of toluylene diisocyanate with 1 mole of trimethylolpropane and blocking the incyanate with phenol.
50 is a boisocyanate obtained by blocking diphenylmethane diisocyanate with cresylic acid.

Furthermore, polyaziridines, which are reaction products of the above-mentioned isocyanate and ethyleneimine, may also be used in combination with the blocked polyisocyanate.

Specifically, polyaziridines include etc.

These polyaziridines are added in an amount of about 0.1 to 20% by weight based on the blocked polyisocyanate.

The blocked polyisocyanate used in the present invention is also called regenerated incyanate, in which an appropriate functional compound is added to the isocyanate group, and the high reactivity of the incyanate group is temporarily blocked at low temperatures. At a certain temperature (above the temperature determined by the functional compound added), that is, heating causes the above-mentioned adduct to dissociate, thereby reducing the thermoplasticity of the binder and imparting thermosetting properties. It is.

Since this dissociation reaction promotes the regeneration of later active isocyanate groups, the above-mentioned crosslinking reaction proceeds completely by heating for a very short time.

Furthermore, in the binder composition of the present invention, dissociation of the blocked polyisocyanate does not occur unless heating is performed, and therefore the blocked polyisocyanate remains inert. has perfect storage stability.

The above blocking agents include phenol, cresol,
Phenols such as xylenol, oximes such as acetone oxime, methyl ethyl ketone oxime, cycloxanone oxime, isopropyl alcohol, 5eC-butyl alcohol, caffryl alcohol, tert-butyl alcohol, tert-octyl alcohol, methyl lactate, ethyl lactate, etc. alcohols, cellosolves such as methyl cellosolve, ethyl cellosolve, isopropyl cellosolve, n-butyl cellosolve, and phenyl cellosolve (
ethylene glycol ether), mercaptans such as ethyl mercaptan, isopropyl mercaptan, tert-butyl mercaptan, heptyl mercaptan, phenyl mercaptan, secondary amines such as methylaniline, ethylaniline, butylaniline, acetamide, benzamide, benzoic acid amide Amides such as maleic acid imide, imide such as phthalic acid imide, lactams such as caprolactam and pyrrolidone, active hydrogen compounds such as acetylacetone, malonic acid ester, acetoacetic ester, sodium sulfite, sodium pyrosulfite, metabisulfite, etc. Sulfite alkali metal salts such as potassium sulfite, hydrocyanic acid, etc. are used.

Next, the crosslinking agent is a substance that chemically bonds the molecules of the linear polymer compound to each other to form a network structure.

Polycarbodiimide is commonly used as a typical crosslinking agent.

This series is from Bayer It is on the market under the trade name ``5TABAXOL''.

Stud binders have been developed in recent years to complete polycondensation reactions in a short period of time to obtain high molecular weight polymers.

In this method, the molecular weight of the polymer is dramatically increased by adding a bifunctional compound such as diphenyl terephthalate to the reaction system after the polycondensation reaction has progressed to a certain extent.

Typical compounds used in this method include:
Those using diesters of dicarboxylic acids (Special Publication Act 1977)
-23479 and Japanese Patent Publication No. 43-23480)
There is a method using (Japanese Patent Publication No. 45-39108 specification).

Examples of metal foils or sheets used for bonding these materials include aluminum, stainless steel, chrome-plated steel plates, nickel-plated steel plates, lead, brass, tinplate, and galvanized iron.

EXAMPLES A more detailed explanation of the present invention will be given below with reference to examples, but the present invention is not limited to these examples.

Note that all percentages in the examples are by weight.

Example 1 A polyethylene terephthalate film with a thickness of 80 μm was coated with Suffix LB (ether-type modified polyester manufactured by Fuji Photo Film Co., Ltd.). 55] was extruded into a film, and the mating surfaces of this and polyethylene terephthalate film were irradiated with an infrared lamp and heated to 160°C to bond them together to create a laminate film of both.

The thickness of Suffix LB in this case was 70μ.

A 50 .mu. thick metal foil shown in Table 1 below was placed on this laminate film, heated and pressed at 150 DEG C. and 3 kg/- for 2 minutes, and a 180 degree peel test was conducted on the laminate.

The results are shown in Table 1 below. Table 1 180 degree peel strength for polyethylene terephthalate film Adherent (metal foil) Aluminum 18.1 kg/2 S
RNM Copper 18.3kg/2
5mm Brass 15.1kg/25mm Example 2 On a polyethylene terephthalate film with a thickness of 100μ, a solution of Suffix LB dissolved in a 50:50 mixed solvent of methyl ethyl ketone and toluene to make a 30% solution was applied, and after drying, the Suffix LB was coated. Fix LB thickness is 30
A laminated film of μ was obtained.

Copper foils with a thickness of 50 μ and a width of 251 nm were arranged at 25 mm intervals between this laminate film and Suffix LB, and heated and pressed at 170°C and 5 kg/crIt for 5 minutes to produce a sandwich-structured flat cable type laminate. Obtained.

The results of measuring the 180 degree peel strength of this laminate are shown in Table 2 below.

Table 2 Adhesion to polyethylene terephthalate film 180 degree peel strength body polyethylene terephthalate/polyethylene terephthalate 17.9kg/25mm
Rate polyethylene terephthalate/copper 18.7 kg
/ 25mm As is clear from the results in the table above, the 180 degree peel strength of polyethylene terephthalate film and polyethylene terephthalate or copper is approximately the same, and the bonded area is uniform and stronger than laminates using conventional adhesives. It has been demonstrated that a stable product can be obtained.

Example 3 Stafix GA (ether-type modified polyester manufactured by Fuji Photo Film ■, triethylene glycol content of 40% of the total glycol content of the polyester) was applied on a polyethylene terephthalate film with a thickness of 100 μm by the same method as in Example 1. A laminate film of extruded polyethylene terephthalate and Stafix GA (thickness 50 μm) was obtained.

Desmodur R (methylene chloride solution with a solid content of triphenylmethane triisocyanate of 25 ml) manufactured by Sumitomo Bayer Urethane Co., Ltd. was applied as a polyisocyanate onto this laminate film, and dried at 50°C.
Glue copper foil with a thickness of 50μ within 2 hours and heat at 150℃ for 10 minutes.
kg/cr? A laminate was obtained by heating and pressurizing with L for 5 minutes.
Example 4 100 parts by weight of Stafix GA and Desmodur A were added to a polyethylene terephthalate film with a thickness of 100 μm.
P 5tableC Sumitomo Bay Industrial Co., Ltd. 20% chloroform solution of a mixture with 35 parts by weight of blocked triisocyanate was applied and dried at 60°C.
A laminated film with an adhesive layer of μ thickness was obtained.

50μ thick on top of the adhesive layer of this laminate film
A laminate was obtained by adhering copper foil and heating and pressing at 200° C. and 10 kL I/− for 20 minutes.

The results of measuring the adhesive strength between polyethylene terephthalate and copper in this laminate are shown in Table 3 below.

When adhering copper foil onto a polyethylene terephthalate film, one was adhered by the method of Example 1 and Example 4 of the present invention, and the other was adhered using a commercially available polyester-based or acrylic epoxy-based adhesive. By comparison, as is clear from the results in Table 3 above, in the case of room temperature adhesion, those bonded by the method of Example 1 of the present invention, and in the case of high temperature adhesion, Example 4 using a triisocyanate blocked product. It was found that the product bonded by the above method had far superior peel strength and shear strength compared to commercially available products.

Claims (1)

[Claims] 1. A laminate of polyethylene terephthalate and metal, characterized in that a polyethylene terephthalate sheet or film is coated with an ether-type modified polyester, and a metal foil or sheet is bonded and heat-fused on the coated surface. Manufacturing method. 2 Claims in which the ether-type modified polyester is a copolyester obtained by heat-treating polyethylene terephthalate with one or more glycols other than ethylene glycol and exchanging the ethylene glycol in polyethylene terephthalate with the glycols. 1st
A method for producing a laminate of polyethylene terephthalate and metal as described in Section 1. 3. Coating a polyethylene terephthalate sheet or film with (1) an ether-modified polyester mixed with a reactive polyisocyanate, a blocked product of a reactive polyisocyanate, a crosslinking agent or a chain extender, or (
2) Applying ether-modified polyester, further coating with reactive polyisocyanate, glocked product of reactive polyisocyanate, cross-linking agent or chain extender to form a composite, and bonding metal foil or sheet to this coated surface or composite surface. A method for producing a laminate of polyethylene terephthalate and metal, which is characterized by heat-sealing. 4. A laminate of polyethylene terephthalate and metal according to claim 3, wherein the polyisocyanate or a blocked product of these polyisocyanates is an isocyanate having at least two isocyanate groups or a temporarily masked blocked product thereof. Method of manufacturing things.