JP2003277714A - Adhesive composition for dry laminate and laminated film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive composition for a dry laminate of a PET film and a metal foil, which is suitable for production of a shielding material by laminating previously a PET film to a metal foil to produce a laminated film and processing the film into a mesh structure by etching to give transparency thereto, the composition further being excellent in adhesiveness and susceptibility to etching. <P>SOLUTION: The adhesive composition comprises, in terms of the solid contents, 100 pts.wt. of a thermoplastic polyester resin having a glass transition temperature of 0-40°C, a number average molecular weight of 2,000-10,000 and an average number of hydroxy group of 2.01-2.5 per molecule and 1-30 pts.wt. of hexamethylene diisocyanate incorporated therein. The laminated film is produced by dry lamination of a PET film and a metal foil using the adhesive composition. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry film having a high transmittance and an excellent etching contamination resistance, which is used for manufacturing an electromagnetic wave shield material (EMI) used in an apparatus that generates an electromagnetic wave such as a plasma display. The present invention relates to an adhesive for lamination.

[0002]

2. Description of the Related Art Since electromagnetic waves are generated at a high level from electronic devices such as plasma displays, it is necessary to provide a shield layer for shielding the electromagnetic waves by some method. In particular, a CRT, a plasma display or the like needs to be provided on the front surface of the screen, and since the translucency is an important characteristic, the metal foil cannot be used as it is. As a conventional shielding method, a transparent substrate having a vapor-deposited film of metal or metal oxide formed on the surface of glass, a mesh made of fibers mixed with a conductive filament, or the like is used. These methods are advantageous in terms of cost and are preferably used, but in order to sell PDPs to the global consumer market, it is required to comply with electromagnetic wave standard class B, and it is not possible to comply with this regulation. There's a problem. As a shield that replaces these, a method of shielding electromagnetic waves by dry laminating a conductive metal foil such as a copper foil or an aluminum foil on a highly transparent film such as PET is generally used. When transparency is required as described above, copper foil is used for the metal foil, and the copper foil is coated with resin, or
There is a shielding material in which a highly transparent film such as PET is preliminarily laminated with a copper foil to form a laminated film, and then a metal foil is processed on a mesh by etching so as to have transparency. Although these are higher in cost than the other methods described above, they are excellent in electromagnetic wave shielding property and can be applied to the strict electromagnetic wave regulation class B.

[0003]

The copper foil and PET used in the etching method are generally dry-laminated using a polyester-based or urethane-based adhesive. Problems often occurred such that the layer was contaminated during etching, and the hue was changed on the entire surface or a part of the screen. In this method, the copper foil is processed into a mesh shape by etching,
It is a fatal defect that the adhesive in the opening is contaminated in order to make it transparent, and an early solution has been desired. The present invention has been made in view of the above circumstances,
An object of the present invention is to provide an adhesive for dry laminating that maintains high transparency without discoloration of the adhesive layer even when etching is performed.

[0004]

As a result of intensive studies to achieve the above object, it was found that the above object can be achieved by specifying the properties of the polyester used for the adhesive, and the present invention was completed. Came to do.

That is, the present invention means a glass transition temperature of 0 to 40 ° C. and a number average molecular weight of 2,000 in terms of solid content.
~ 10,000, the average number of hydroxyl groups per molecule is 2.01
An adhesive composition for dry laminating, comprising 1 to 30 parts by weight of an aliphatic isocyanate with 100 parts by weight of a thermoplastic polyester resin of 2.50, and a PET film using the adhesive. The present invention relates to a laminated film obtained by dry laminating a metal foil.

As the thermoplastic polyester applicable in the present invention, a dibasic acid, a glycol having 2 to 15 carbon atoms, and an oxyacid can be used in an appropriate combination so as to obtain a polyester having desired physical properties. The thing obtained by polycondensation by a conventional method is mentioned.
Specific examples of the dibasic acid include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid,
Aromatic dibasic acids such as diphenyldicarboxylic acid, such as adipic acid, azelaic acid, sebacic acid, succinic acid, pimelic acid, speric acid, dimer acid and other aliphatic dibasic acids such as hexahydroterephthalic acid, hexahydro Examples thereof include alicyclic dibasic acids such as isophthalic acid and hexahydrophthalic acid. Examples of glycols include ethylene glycol, 1,4-butanediol, hexamethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, 1,4-bisoxyethoxybenzene, bisphenol A, diethylene glycol and polyethylene glycol. Examples of the oxyacid include p-oxybenzoic acid, 1,2-hydroxystearic acid, p-β-oxyethoxybenzoic acid and the like. In addition to these dibasic, glycol and oxyacids, an appropriate amount of trivalent or higher valent ester forming group is added,
The number of hydroxyl groups of the thermoplastic polyester resin can be designed within a predetermined range. Examples of the compound include trimethylolpropane, pentaerythritol, glycerin,
Examples thereof include trimellitic acid and pyromellitic acid.

The thermoplastic polyester resin used in the present invention has a glass transition temperature of 0 ° C to 40 ° C. If the glass transition temperature is lower than 0 ° C, the contamination with the etching solution is large, and if it is higher than 40 ° C, the flexibility is lowered and the productivity is lowered. The thermoplastic polyester resin used in the present invention has a number average molecular weight of 2,000 to 10,000. If the molecular weight is less than 2,000, the crosslink density becomes too high, and problems such as curling of the laminate due to curing shrinkage occur. If the molecular weight is more than 10,000, the solid content of the solution cannot be sufficiently increased, and therefore problems such as the inclusion of air bubbles during coating and drying are likely to occur. The thermoplastic polyester resin used in the present invention,
The average number of hydroxyl groups in one molecule is 2.01 to 2.50. When the average number of hydroxyl groups in one molecule is less than or equal to 2, the contamination by the etching solution is large, and when it is more than 2.50, the crosslinking density becomes too high, and the laminate shrinks due to curing shrinkage. Occur.

The aliphatic isocyanate used in the present invention includes, for example, hexamethylene diisocyanate and modified products thereof, but there is no particular limitation as long as it does not cause discoloration after curing. The aliphatic isocyanate is used by mixing 1 to 30 parts by weight with respect to 100 parts by weight of the thermoplastic polyester resin. If the amount is less than 1 part by weight, a sufficient crosslinking density cannot be obtained, and the adhesive layer is softened by heat during etching, causing a problem that the etching mesh has a poor appearance. When the amount is more than 40 parts by weight, the excess and unreacted aliphatic isocyanate hinders the formation of the adhesive film and similarly causes a problem that the etching mesh has a poor appearance.

In addition to the above, a filler, a surfactant, an antioxidant, an ultraviolet absorber and the like may be added to the present invention, if necessary, within a range that does not deteriorate the characteristics.

As a method of applying the adhesive composition,
Although not particularly limited, it is preferably applied to the PET film side from the viewpoint of workability. In addition, it is preferable to apply with a gravure coater or the like in terms of application uniformity. The dry coating amount of the adhesive composition is preferably 1 to 50 g /
m ² , more preferably 3 to 10 g / m ² . 1 g /
If m ² or less, adhesiveness cannot be obtained, and conversely, if it is 50 g / m ² or more, not only the cost increases but also the permeability decreases, which is not preferable.

After applying the adhesive composition, it is dried and laminated with a conductive metal foil such as a copper foil. Lamination is possible even at room temperature, but from the viewpoint of suppressing variations in product quality due to seasonal temperature differences, it is desirable to perform thermal lamination with rolls heated to 40 to 60 ° C. The laminated laminate is provided in the form of a coil.

[0012]

EXAMPLES Next, examples and comparative examples of the present invention will be described. (Example 1) Hybon YD120-1 (Hitachi Chemical Polymer Co., Ltd. thermoplastic polyester resin, glass transition temperature 20 ° C., average number of hydroxyl groups per molecular weight 2.10, 2.10)
Number average molecular weight about 7,000 Ethyl acetate solution Active ingredient 50%) 200 parts by weight (100 parts by weight as active ingredient)
On the other hand, 4 parts by weight (3 parts by weight as an active ingredient) of Coronate HL (75% by weight of an aliphatic isocyanate ethyl acetate solution manufactured by Nippon Polyurethane Co., Ltd.) was sufficiently mixed, and an adhesive composition for dry lamination was prepared. And

(Example 2) Example 1 was repeated except that 4 parts by weight of Coronate HL was changed to 10 parts by weight.
I went the same way.

(Example 3) Hibon YD12 of Example 1
0-1 200 parts by weight of Hibon YD120-21 (Hitachi Kasei Polymer Ltd. thermoplastic polyester resin, glass transition temperature 18 ° C., average number of hydroxyl groups per molecular weight of 2.15, number average molecular weight of about 4,500 acetic acid) Ethyl solution Active ingredient 40%) 250 parts by weight (1 as active ingredient
The same procedure as in Example 1 was carried out except that the amount was set to 00 parts by weight.

Comparative Example 1 The thermoplastic polyester resin solution Hibon YD120-1 of Example 1 was replaced with Hibon YA7.
80-1 (Hitachi Chemical Polymer Co., Ltd. thermoplastic polyester resin, glass transition temperature -10 ° C., average number of hydroxyl groups per molecular weight of 2.0, number average molecular weight of about 8,500)
Ethyl acetate solution The procedure of Example 1 was repeated, except that the active ingredient was 63%) (159 parts by weight, 100 parts by weight as the active ingredient).

(Comparative Example 2) Coronate H of (Example 1)
Example 1 was repeated except that 4 parts by weight (3 parts by weight as an active ingredient) of L (produced by Nippon Polyurethane Co., Ltd., an aliphatic isocyanate 75% ethyl acetate solution active ingredient) was omitted from the formulation.

The above materials were added and sufficiently stirred to prepare an adhesive composition for dry lamination. The dry laminating adhesive composition prepared as described above was continuously coated on a PET film so that the dry coating amount was 5 g / m ² . The PET film is a highly transparent PE for optics.
T (manufactured by Toyobo, thickness 50 mm, highly transparent type for optics)
Was used. After coating, the coated foil was left at 100 ° C. for 2 minutes in a dried state for 10 seconds, and then heated to 60 ° C. in advance, using a laminator at a speed of 1 m / min. After laminated with blackening treated foil), 23 ℃ ・ 65
The laminate film (A) was prepared by curing in a% RH atmosphere for 5 days. In addition, in order to use it for the etching contamination test,
PET (B) with an adhesive was prepared by the same method except that a copper foil was not laminated on the above laminated film.

(Adhesion test) The laminated film prepared by the above method was cut into a 1 cm wide strip and subjected to 1 at 23 ° C.
T-peel off at a speed of 50 mm / min in the 80 degree direction,
The peel adhesion strength was measured.

(Etching Contamination Test) An etching solution (Asahi Denka Kogyo KK, ferric chloride, 40 ° Be) was adjusted to 50 ° C., and the above PET (B) with an adhesive was 25 m.
What was cut into m squares was put in and left for 3 minutes in a stirred state. Then, it was washed with running tap water for 3 minutes, wiped off the water on the surface, and allowed to stand at 23 ° C. for 24 hours, and then the transmittance (Toyo Seiki Co., Ltd. direct reading haze meter) and color difference Lab system color difference measurement (Minolta color difference) Total)
PET with adhesive without etching immersion
Compared with (B).

[0020]

[Table 1]

[0021]

From the results shown in Table 1, Examples 1, 2, and 3 are excellent in etching stain resistance and adhesiveness, and the product of the present invention is highly versatile, and is used for dry lamination of PET and metal foil. It can be seen that an agent composition can be provided.

The adhesive composition for dry laminating of the present invention is obtained by laminating PET and a metal foil and laminating a PET film and an aluminum foil as well as a shield layer for shielding electromagnetic waves used in plasma displays and the like. It can also be widely used as a shield material that is commonly used in mobile phones and personal computers.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F100 AB01 AB01B AB33 AB33B                       AH02C AH02G AH03C AH03G                       AK42 AK42A AK42C AK42G                       AR00C AT00A CB00 CB01                       EC18C EH46 EJ86 GB41                       JA05C JA07C JL11 YY00C                 4J040 ED001 ED031 EF292 GA05                       LA01 LA02 MA10 MB09 NA08

Claims (2)

[Claims] 1. A glass transition temperature of 0 ° C. or less in terms of solid content.
1 to 30 parts by weight of an aliphatic isocyanate based on 100 parts by weight of a thermoplastic polyester resin having a number average molecular weight of 2,000 to 10,000 and an average number of hydroxyl groups of one molecule of 2.01 to 2.50 at 40 ° C. An adhesive composition for dry lamination, characterized by being blended. 2. A laminated film obtained by dry laminating a PET film and a metal foil using the adhesive according to claim 1.