JPH0659714B2 - Substrate having a surface protection film adhered thereto and method of manufacturing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a substrate having a surface protective film adhered thereto and a method for producing the same. More specifically, the present invention relates to a substrate having a surface protective film adhered thereto suitable for the field of electronic materials and a method for manufacturing the same.

In particular, the present invention relates to a substrate having a form suitable for producing, storing, and distributing a substrate requiring a clean surface, and a method for producing the substrate.

The field of use of the present invention is in the field of electronic materials, and in particular, substrates for photoelectric conversion devices such as solar cells, photosensors, and optical switches, substrates for thermal heads, and the like can be mentioned.

[Conventional technology]

Among these, for example, in the case of a substrate for a solar cell, particularly a substrate coated with a polyimide resin as an insulating layer on a metal plate, a dedicated carrier case may be used for transportation because it is necessary to keep the surface clean and intact, There is a case where a special interleaving paper is sandwiched, but the transport efficiency is low and the work is troublesome, so that neither method is preferable.

There is also a type of substrate with a protective film attached with an adhesive on the surface, but when the protective film is peeled off, part of the adhesive adheres strongly to the substrate surface, impairing cleanliness. Not preferable.

[Object of the Invention]

In view of these circumstances, the inventors of the present invention have arrived at the present invention as a result of earnestly examining a substrate that can be transported and stored while keeping the surface of the substrate clean and intact, and a manufacturing method thereof.

That is, the gist of the present invention is a substrate composed of a metal plate, an oriimide resin layer adhered to the surface thereof, and a peelable film attached to the surface of the resin layer, and a method for producing the same.

In addition to the above advantages, the substrate of the present invention brings a great advantage in terms of easiness of handling in transportation, storage, press punching and the like to the next step in manufacturing a substrate.

[Structure of Invention]

 The present invention will be described in detail below.

The substrate of the present invention comprises a metal plate, a polyimide resin layer deposited on the surface of the metal plate, and a peelable film deposited on the surface of the resin layer.

In the present invention, a metal plate such as a stainless plate, an aluminum plate, an aluminum alloy plate, a copper plate, a copper alloy plate, an iron plate, a molybdenum plate, a chrome plate, or a zinc plate is preferably used as the metal plate.

Especially when using an aluminum plate as the metal plate,
Chromate treatment, phosphate treatment, titanium tannate treatment, etc., as a surface treatment for adhesion of aluminum plate, by forming a chemical conversion film, sulfuric acid, phosphoric acid, chromic acid, sulfamic acid, boric acid, oxalic acid, sulfosalicylic acid, malon By acid succinic acid, citric acid, malic acid, etc. electrolytic bath roughening treatment by electrolytic bath formation, hydrochloric acid, nitric acid etc. electrolytic roughening treatment, brush polishing, mechanical roughening treatment such as honing A method etc. can be adopted.

The thickness of these metal plates is generally selected in the range of 0.05 to 5 mm, preferably 0.1 to 1 mm. Generally, the surface roughness is preferably as smooth as possible. For example, in the case of a stainless steel plate, Rmax is 1 μm or less, preferably 0.5 μm.
The following are preferably used. If the hardness of the metal plate is too hard, the workability is poor, and if it is too soft, edge deformation (burrs) is likely to occur during press punching or the like, which is not preferable. For example, a stainless plate having a Vickers hardness of 100 to 300, particularly preferably 150 to 250, is used.

In the present invention, the polyimide resin is a solvent-soluble type, and includes polyimide, polyamideimide, polyetherimide, and a mixture thereof. Specifically, benzophenone tetracarboxylic dianhydride (BTDA) and two kinds of aromatic diisocyanates, that is, 4,4'-diisocyanodiphenylmethane and 2,4-diisocyanotoluene are copolymerized. Synthesized, for example (Ar is Or Represents However, Is And / or Represents ) Having the structure of.

Made by General Electric Company, known as "Ultem" Having the structure of.

Having a structure such as.

Synthesized from biphenyl tetracarboxylic dianhydride and aromatic diamine via polyamic acid Having the structure of.

Made by Ciba Geigy, known as trade name "XU-218" Having the structure of.

Approximately 80 mol% of repeating units are of formula And has a structure represented by A copolyamideimide having a structure represented by:

Made by Amoco, known as "Torlon" And the like.

Further, a mixture of polyimide with a solvent-soluble polymer such as polysulfone or polyether sulfone as a second component is also included.

In the present invention, 10 to 30 mol% of repeating units are represented by the formula And the remaining 90 to 70 mol% is of the formula A copolyimide having a structure represented by: And has a structure represented by A copolyamideimide having a structure represented by is preferably used.

The former is particularly excellent in heat resistance. The latter has excellent heat resistance and flexibility, and can be suitably used when bending is required.

The logarithmic viscosity (ηinh) of the copolyimide and copolyamideimide of the present invention is selected from the range of 0.1 to 10 dl / g (0.5% in N-methylpyrrolidone, measured at 30 ° C.).

The thickness of the polyimide resin layer is preferably 1 to 100 μm, preferably 2 to 80 μm, and more preferably 5 to 50 μm. If the film thickness is smaller than this range, defects such as pinholes are likely to occur, and the risk of dielectric breakdown is increased when used as an electronic component, which is not preferable. Further, if the film thickness is larger than this range, the solvent used in the step of applying the resin is likely to remain, which is also not preferable.

The peelable film in the present invention is a film adhered to the surface of the plate-like object in order to physically and mechanically protect the surface of the plate-like object. Normal peel strength, i.e. 0.5-20 g / cm, preferably 1-1, without leaving any chemical traces
A film that can be easily peeled off at about 0 g / cm (a numerical value at a peeling speed of 0.5 m / min). Specifically, it is a peelable protective film described in JP-A-60-245549, that is, a protective film composed of at least two resin layers, and (I) the resin forming the innermost layer in contact with the surface to be protected is a) Low density polyethylene with a density of 0.91 to 0.935 g / cc, 4
0 to 95% by weight, b) an amorphous or low crystalline ethylene / α-olefin copolymer having a density of 0.86 to 0.91 g / cc, 5 to 60% by weight, a mixture, and a), b At least one of the components) is an unsaturated carboxylic acid or an unsaturated carboxylic acid anhydride, and is composed of a modified polyolefin composition partially or wholly modified, and (II) the outermost layer has an elastic modulus of 6000 kg / cm ² or more. A peelable surface protective film or the like characterized by being a thermoplastic resin layer having a heat distortion temperature of 140 ° C. or higher under a load of 4.6 kg / cm ² is preferably used.

The film which is adhered to the surface via an adhesive is distinguished from the peelable film of the present invention as long as it is confirmed analytically that the adhesive remains on the surface.

Next, a method for manufacturing the substrate of the present invention will be described.

First, a solvent solution of polyimide resin is applied to the surface of a metal plate. There are various coating methods such as spin coating, doctor blade coating, bar coating, roll coating, and flow coating. For example, if it is roll coating, it depends on the type of roll, the viscosity of the resin solution, the concentration, etc. Since the coating can be applied to a film thickness of about 3 to 300 μm, the above operating conditions may be appropriately adjusted so that the dry film thickness becomes a predetermined film thickness.

When coating is completed, heat treatment is performed. Depending on the type of solvent used for the resin solution to be applied, there is one that absorbs moisture and solidifies and precipitates the resin when left in the atmosphere after application, so in this case, depending on the humidity of the atmosphere, it takes a few seconds to It is necessary to heat immediately within a few minutes so that the residual solvent concentration becomes a sufficiently low value. As a method of heat treatment, 200 to 40
It heats at about 0 degreeC for about 5 to 30 minutes. Specifically, depending on the type of solvent and the use of the substrate of the present invention, for example, if the solvent is dimethylformamide and the use is a substrate for amorphous silicone solar cells, it may have a bad influence on the CVD operation under vacuum. The residual solvent concentration is 150 pp so that it does not come out
It must be less than m.

Depending on the type of solvent used, when the temperature is suddenly raised, the temperature may be rapidly vaporized and the surface property may be deteriorated. Therefore, it is preferable to raise the temperature gradually. In this case, the temperature may be raised continuously or stepwise at intervals of several tens of degrees, and the temperature rise pattern can be appropriately selected according to the degree of surface property and the residual solvent concentration.

After the heat treatment of the polyimide resin is completed, a peelable film is attached to the surface of the resin layer. The film can be adhered by softening the film under heating and pressure to adhere the film. For example 80-160 ℃
Good adhesion can be achieved by passing the rolls heated to a certain degree at a speed of about 0.5 to 5 m / min while sandwiching them with a pressure of about 0.5 to 5 kg / cm ² G. The peel strength at this time is 0.5 to 20 g / cm (a numerical value at a peeling speed of 0.5 m / min), and the polyimide resin layer surely adheres to the surface of the polyimide resin layer at the same time as peeling.
The substrate can be easily and easily peeled off without causing deformation of the substrate as if it were a normal human hand.

In this way, the substrate of the present invention is manufactured. Further, a good substrate can be manufactured also by punching this substrate into a predetermined shape and size. At this time, the presence of the film on the surface brings a great advantage in facilitating the punching process and the work associated therewith.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples.
The present invention is not limited to this.

Preparation Reference Example 1 Using the procedure described in Example 4 of US Pat. No. 3,708,458, 3,3′4,4′-benzophenonetetracarboxylic anhydride and 80 mol% tolylene diisocyanate (2,
A copolymerized polyimide was polymerized from a mixture containing about 80 mol% of 4-isomer and about 20 mol% of 2,6-isomer) and 20 mol% of 4,4'-diphenylmethane diisocyanate.

The polymerization solvent used was N, N'-dimethylformamide, and the resin concentration was 21% by weight.

Relative viscosity (ηinh) of this copolyimide at 30 ℃
(0.5% in dimethylformamide) was 0.6 dl / g.

PRODUCTION REFERENCE 2 In 10 pre-dried reactors 614.82 g (3.20 mol) trimellitic anhydride and 132.90 g (0.80)
Mol) of isophthalic acid. The reactor was equipped with a thermometer, condenser, stirrer and nitrogen inlet.

1000.96 g (4.0 mol) of 4, in a dry bottle of 5,
4'-Methylenebisphenyl isocyanate (hereinafter MD
I) and then 434 ml of N-methylpyrrolidone (hereinafter abbreviated as NMP) and MDI
Was dissolved. Add this MDI solution to the reactor, then M
3650 ml NMP to rinse bottles with DI
Was added.

The solution was heated from 53 ° C. to 170 ° C. over 3 hours and 40 minutes under a stirring speed of 65 rpm and a nitrogen atmosphere, and further heated to 169 ° C. to 171 ° C. for 1 hour and 55 minutes.
In this way about 80 mol% of the repeating units With about 20 mol% of the repeating units A 25% by weight solution of NMP of random copolyamideimide having the structure of was obtained.

The logarithmic viscosity (η
inh) (0.5% in N-methylpyrrolidone) is 0.60
It was 3 dl / g.

This solution was added to methanol to precipitate a polymer, which was then dried at 150 ° C. for 3 hours to obtain a copolyamideimide powder.

Production Reference Example 3 Ethylene-butene 1 copolymer (ethylene content 87 mol%, butene-1 content 13 mol%, crystallinity 20%) 1
00 parts by weight, 0.025 parts by weight of α, α'-bis-t-butylperoxy-p-diisopropylbenzene dissolved in a small amount of acetone, and 0.8 parts by weight of maleic anhydride are blended in a Henschel mixer. .

The mixed granules were extruded into pellets at 230 ° C. using an extruder having an inner diameter of 40 mmφ and L / D = 28.

After crushing a part of this pellet, unreacted maleic anhydride was extracted with acetone by a Soxhlet extractor for 12 hours. When this product was quantified for maleic anhydride by infrared spectrum, 0.7% by weight of maleic anhydride was graft-reacted.

The modified ethylene copolymer pellets thus obtained and low density polyethylene pellets were blended and
A laminated film was produced by co-extrusion with 2030A (registered trademark of Mitsubishi Kasei, nylon 6/66 copolymer, copolymerization ratio 85/15, ηrel = 3.5). The thickness of this film was 70 μm, and the nylon portion was 40 μm and the modified ethylene copolymer portion was 30 μm.

Example 1 Stainless steel BA plate as a metal plate, Sus430, size 3
A 00 mm square and a plate thickness of 0.15 mm were used. The Vickers hardness was 200, and the surface roughness was Rmax = 1500Å, Ra = 180Å. As the polyimide resin, the solution described in Production Reference Example 1 was adjusted to a solid content concentration of 15% by weight using dimethylformamide as a solvent, and the solution was passed through a filter having a pore size of 1 μm.

The polyimide resin solution was applied to one surface of the metal plate with a roll coater at room temperature and immediately heated in an oven at 80 ° C for 5 hours.
Then, the temperature was gradually raised and the temperature was increased to 350 ° C. for 5 minutes. The obtained coating film had a film thickness of about 10 μm, and the surface roughness was Rmax = 250Å, Ra = 50Å.

After that, the film described in Production Reference Example 3 was laminated under the conditions where the modified ethylene copolymer part was in contact with the polyimide resin, the roll temperature was 120 ° C., the roll pressing pressure was 2 kg / cm ² G, and the conveying speed was 1 m / min. did.

Further, after that, a punching die was attached to a 45-ton crank press and punching was performed to obtain a substrate with a surface protective film having a size of 100 mm square. The peel strength of the film on this substrate was 2.5 g / cm (a numerical value at a peel strength of 0.5 m / min, the same applies hereinafter).

Example 2 A substrate with a surface protection film was obtained in the same manner as in Example 1 except that the polyimide resin described in Production Reference Example 2 was used and the heat treatment temperature was 300 ° C.

The surface roughness of the coating film on this substrate is Rmax = 280Å, Ra
= 55Å, and the peel strength of the film was 3.1 g / cm.

Example 3 As a metal plate, purity 99.7%, size 300 mm × 300
An aluminum plate having a thickness of 0.8 mm and a thickness of 0.8 mm was degreased, anodized in a 30% phosphoric acid aqueous solution at 30 ° C. for 40 minutes at a direct current of 40 V, washed with water, and dried. The size of the pores of the anodized film of the metal plate was 500 to 800Å as a result of electron microscope observation, and the average size was about 650Å.
The density was about 100 particles / μm ² . As the polyimide resin, the solution described in Production Reference Example 1 was adjusted to a solid concentration of 25% by weight using dimethylformamide as a solvent, and the solution was passed through a filter having a pore size of 1 μm.

The polyimide resin solution was applied to one surface of the metal plate with a doctor knife at room temperature, immediately treated in an oven at 80 ° C for 15 minutes, and then continuously heated to 320 ° C for 5 minutes.
Processed for a minute. The film thickness of the obtained coating film was about 50 μm.

After that, the film was laminated in the same manner as in Example 1 and subjected to press punching to obtain a substrate with a surface protective film. The peel strength of the film on this substrate is 2.0 g /
It was in cm.

Example 4 A solution obtained by mixing equal amounts of the polyimide resin described in Production Reference Example 1 and that described in Production Reference Example 2 in terms of solid content weight, the solid content concentration was adjusted to 22% by weight, and the pore diameter was 1 μm. A substrate with a surface protective film was obtained in the same manner as in Example 3 except that the solution passed through the filter was used and the thickness of the dried coating film was 25 μm. The peel strength of the film on this substrate was 2.1 g / cm.

〔The invention's effect〕

The substrate of the present invention is useful in the field of electronic materials, and is particularly suitable as a substrate for photoelectric conversion devices such as solar cells, photosensors, and optical switches, and a substrate for thermal heads.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shizue Sakai 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Sanryoh Chemical Industry Co., Ltd. (72) Inventor Toru Imanara 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Address Sanryo Kasei Co., Ltd., Research Laboratory (56) Reference JP-A-58-8636 (JP, A) JP-A-58-186571 (JP, A)

Claims (9)

[Claims] 1. A substrate comprising a metal plate, a polyimide resin layer deposited on the surface thereof, and the following film deposited on the surface of the resin layer adhered thereto. (I) The resin forming the innermost layer in contact with the protected surface is a) low density polyethylene having a density of 0.91 to 0.935 g / cc, 4
0 to 95% by weight, b) a mixture of an amorphous or low crystalline ethylene / α-olefin copolymer having a density of 0.86 to 0.91 g / cc, 5 to 60% by weight, and a), b)
At least one of the components is an unsaturated carboxylic acid or an unsaturated carboxylic acid anhydride and is composed of a modified polyolefin composition partially or wholly modified, and (II) the outermost layer has an elastic modulus of 6000 kg / cm ² or more, A peelable surface protective film which is a thermoplastic resin layer having a heat distortion temperature of 140 ° C or more under a load of 4.6 kg / cm ^2. 2. The substrate according to claim 1, wherein the metal plate is stainless steel or aluminum. 3. The polyimide resin comprises 10 to 10 repeating units.
30 mol% is the formula And the remaining 90 to 70 mol% is of the formula The substrate according to claim 1 or 2, which is a copolyimide having a structure represented by: 4. A polyimide resin containing 70 to 60 repeating units.
90 mol% is the formula And has a structure represented by The substrate according to claim 1 or 2, which is a copolyamideimide having a structure represented by: 5. A method of applying a solvent solution of a solvent-soluble polyimide resin to the surface of a metal plate, heating the resin to cure the resin, and then pressing a heating roll to attach the following film. A method for manufacturing a substrate having a characteristic surface protection film attached thereto. (I) The resin forming the innermost layer in contact with the protected surface is a) low density polyethylene having a density of 0.91 to 0.935 g / cc, 4
0 to 95% by weight, b) a mixture of an amorphous or low crystalline ethylene / α-olefin copolymer having a density of 0.86 to 0.91 g / cc, 5 to 60% by weight, and a), b)
At least one of the components is an unsaturated carboxylic acid or an unsaturated carboxylic acid anhydride, and is composed of a modified polyolefin composition partially or wholly modified, and (II) the outermost layer has an elastic modulus of 6000 kg / cm ² or more, A peelable surface protective film which is a thermoplastic resin layer having a heat distortion temperature of 140 ° C or more under a load of 4.6 kg / cm ^2. 6. The method for manufacturing a substrate according to claim 5, wherein press punching is performed after the peelable film is attached. 7. The method for producing a substrate according to claim 5, wherein the metal plate is stainless steel or aluminum. 8. The polyimide resin is composed of 10 to 10 repeating units.
30 mol% is the formula And the remaining 90 to 70 mol% is of the formula The method for producing a substrate according to any one of claims 5 to 7, which is a copolyimide having a structure represented by: 9. A polyimide resin comprising 70 to 60 repeating units.
90 mol% is the formula And has a structure represented by The method for producing a substrate according to any one of claims 5 to 7, which is a copolyamideimide having a structure represented by: