JPH0664125A - Manufacture of laminated board - Google Patents

Abstract

(57) [Summary] [Problem] To provide a method for producing a laminate plate which has excellent adhesion and corrosion resistance and can be pressure-bonded at low temperature without peeling or swelling phenomenon with time. [Constitution] (1) A surface treatment process in which a material is subjected to cleaning, activation or chemical conversion treatment. (2) Undercoating process in which an epoxy-based, epoxy / acrylic-based, or polyester-based resin is mixed with a cross-linking agent and a rust preventive pigment on the material to form a dry coating film of 1 to 20 μm and baking treatment. . (3) Apply an adhesive containing acrylic, rubber, epoxy, urethane, polyester, olefin, or amide resin as the main component to the undercoat surface and apply it in the temperature range of 100 to 170 ° C. Adhesive application step of forming an adhesive layer having a dry film thickness of 1 to 20 μm by heating. (4) Put a resin film on the adhesive coated surface.
Laminating process in which pressure bonding is performed in the temperature range of 00 to 170 ° C. Are sequentially applied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a laminated sheet by laminating resin films on various materials, and particularly to a laminated sheet capable of excellent adhesion and lamination without design return by low temperature pressure bonding. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Conventionally, laminating technology has been put to practical use in various fields by coating various resin films and coatings on the surface of a base material such as a steel plate with an adhesive to improve durability and cosmetic properties. However, the adhesives used in this process are always required to be improved. The reason for this is that the original function of the adhesive is to make the laminate film adhere to the material surface, but there are other matters such as prevention of rust in a corrosive environment, prevention of floating of the laminate film and blister. It is extremely important. As a solution to this problem, many attempts to add an anticorrosive pigment to an adhesive have been proposed (JP-A-55-61456, JP-A-56-58859, JP-A-58-171949, JP-A-58-171949, (Japanese Laid-Open Patent Publication No. 59-14941, Japanese Laid-Open Patent Publication No. 59-14943, etc.).

However, the addition of a rust preventive pigment to the adhesive causes a decrease in the adhesive strength, so that it is difficult to balance the corrosion resistance and the adhesiveness.
Therefore, inadequate adhesion is often caused, and the film surface peels, floats, or blister due to blisters during long-term use. Furthermore, in the prior art, the temperature of 190 ° C. or higher is required as the hot pressing condition of the laminated film, which requires a large amount of process equipment, consumes too much energy, and laminates a film having a surface pattern such as embossing. If this is attempted, there is a problem in that the embossed pattern is erased by causing the design to return during the hot pressing step, or the residual stress of the adhesive layer becomes large, so that peeling at the adhesive interface with time easily progresses.

[0004]

DISCLOSURE OF THE INVENTION As a result of intensive studies to solve the above-mentioned problems of the prior art, the inventors of the present invention have undercoated a specific resin component containing a rust preventive pigment on the material surface in advance. After that, when the resin film was heated and pressure-bonded through an adhesive containing no rust-preventive pigment, it was confirmed that a laminate plate having sufficient durability could be obtained by low-temperature pressure-bonding at 170 ° C. or lower.

The present invention has been developed on the basis of the above-mentioned findings, and an object thereof is to provide excellent adhesion and corrosion resistance without causing phenomena such as design return due to low temperature pressure bonding, It is an object of the present invention to provide a method for producing a high-quality laminated plate which does not cause peeling or blistering over time.

[0006]

The method for manufacturing a laminate according to the present invention for achieving the above object is characterized in that the following steps are sequentially applied. (1) At least 1 of cleaning, activation or chemical conversion to the material
Surface treatment process that performs two treatments. (2) An epoxy-based, epoxy / acrylic-based or polyester-based resin and a cross-linking agent as main components, and any undercoat paint containing a rust preventive pigment was applied to the material to form a dry coating film of 1 to 20 μm. Subbing coating process for baking afterwards. (3) Acrylic, rubber, epoxy, urethane, polyester, olefin or amide resin 1
100 to 100% by applying an adhesive containing a cross-linking agent as a main component by one kind or two or more kinds, if necessary, to the undercoat coating film surface.
Dry film thickness of 1 to 20 μm by heating to a plate temperature range of 170 ° C
Adhesive application step of forming the adhesive layer of. (4) A laminating step in which a resin film is pressure-bonded to the adhesive-coated surface in a temperature range of 100 to 170 ° C.

Examples of the plate material to be laminated in the present invention include cold rolled steel plates, steel plates plated with zinc, lead or their alloys, stainless steel plates, aluminum plates, aluminum or aluminum alloy plated plates, brass plates, copper plates. Examples thereof include metals, plastic materials having a heat resistant temperature of 170 ° C. or higher, and plate-shaped, sheet-shaped, coil-shaped, etc. are used.

[0008] These materials are first subjected to a surface treatment step in which treatments such as cleaning, activation and chemical conversion are performed individually or in combination. Means such as alkali degreasing and electrolytic cleaning are applied as the cleaning treatment, and means such as etching and metal deposition are applied to the activation treatment. Further, the chemical conversion treatment is usually a zinc phosphate treatment in which a zinc phosphate coating is deposited in the range of 0.2 to 3 g / m ² , or a metal chromium amount of ² to 50 mg / m ^2.
Chromate treatment for adhering in the range of ² is applied, but not limited to these treatments, any method may be used as long as it is a chemical conversion treatment for improving the adhesion of the undercoat paint.

The next undercoating step is an important process step of the present invention, and except for this step, the intended effect is not achieved. The undercoat paint applied is an epoxy resin,
An epoxy / acrylic resin or polyester resin and a cross-linking agent are main components, and a rust preventive pigment is added to these resin compositions.

Any type of epoxy resin can be used, but when a bisphenol type epoxy resin is used, for example, an epoxy equivalent of 4 is preferable as a property.
50-4000, more preferably 450-2500, number average molecular weight 2000-15000, preferably 8000.
Those up to 12000 are effective for the purpose of the present invention. If the epoxy equivalent is less than 450, the corrosion resistance decreases, and if it exceeds 4000, the viscosity becomes too high and the workability deteriorates. When the number average molecular weight is less than 2000, the corrosion resistance is reduced, and when it exceeds 15,000, the formed coating film becomes hard and the adhesion during processing deteriorates. The epoxy / acrylic resin may be a thermosetting type or a thermoplastic type, as long as it is an acrylic resin compatible with the epoxy resin. At this time, the acrylic resin has a number average molecular weight of 2,000 to 15,000, and more preferably 8,000 to 5,000.
A resin having an epoxy resin / acrylic resin ratio of 100/5 to 35 (NV weight ratio) is preferably used. If the number average molecular weight of the acrylic resin is less than 2000, the corrosion resistance deteriorates, and if it exceeds 15,000, the viscosity becomes too high and the workability deteriorates. Any type of polyester resin can be used as long as it is a linear polymer polyester resin.
Those having a number average molecular weight of 2,000 to 30,000, and more preferably 5,000 to 25,000 are preferably used. If the number average molecular weight is less than 2000, the corrosion resistance is insufficient, and 3
When it exceeds 0000, the viscosity becomes high, which causes the workability to be impaired.

As the cross-linking agent, for example, a melamine resin such as butylated melamine or methylated melamine, and a block or non-block type polyisocyanate compound are used alone or in a mixture at an arbitrary ratio. The mixing ratio of the crosslinking agent to the resin is 100: 1 to 30, preferably 10
Set in the range of 0: 5 to 15. If the compounding ratio of the cross-linking agent is below this lower limit, the corrosion resistance will be deteriorated, and conversely if it exceeds the upper limit, the coating film hardness will be high and the adhesion at the time of processing will be deteriorated.

The rust preventive pigments added to the resin composition include chromic acid compounds such as strontium chromate, zinc chromate, calcium chromate and barium chromate, zinc phosphate, silica phosphate, condensed aluminum phosphate and the like. Phosphorus compounds, such as phosphorus-vanadine compounds described in JP-A-1-131281, which are synthesized from phosphate ions and vanadate ions, are used, and each is used alone or in combination. These rust preventive pigments are preferably set in a range of 5 to 100, preferably 10 to 40 as a solid content weight ratio with respect to 100 of the resin composition (resin + crosslinking agent). If the compounding ratio of the rust preventive pigment is less than the lower limit of the above range, the corrosion resistance is deteriorated, and if it exceeds the upper limit, sufficient adhesion cannot be obtained.

The above undercoat paint is applied and dried on the surface of the material by using an appropriate means such as a roll coater, curtain coater, flow coater, die coater, spray (air or airless), and then baked. At this time, it is important to apply the coating so that the thickness of the coating after drying is 1 to 20 μm. If the thickness is less than 1 μm, corrosion resistance cannot be imparted, and if it exceeds 20 μm, the adhesion decreases. To do. The baking treatment of the coating film is preferably performed in a temperature range in which the plate temperature is 150 to 250 ° C, and more preferably in a temperature range of 180 to 220 ° C. When the temperature is lower than 150 ° C, the corrosion resistance decreases, and when the temperature is higher than 250 ° C, the adhesion tends to decrease.

The material that has undergone the undercoat coating step is then transferred to the adhesive coating step. In this step, one or more of acrylic, rubber-based, epoxy-based, urethane-based, polyester-based, olefin-based, or amine-based resin is used as a main component, and if necessary, melamine resin or polyisocyanate compound, etc. It is carried out by using an adhesive liquid prepared by blending the crosslinking agent of (1) and dissolving it in a solvent and applying this to the surface of the undercoat coating film. Use a solvent that dissolves the resin and has a boiling point not higher than the baking temperature of the adhesive, and apply it by an appropriate means such as a roll coater, curtain coater, flow coater, die coater, spray (air or airless). To do. 100 to 1 after coating
It is heated in the plate temperature range of 70 ° C. to form a semi-cured adhesive layer having a dry film thickness of 1 to 20 μm. If the dry film thickness is out of the above range, sufficient adhesion cannot be imparted.

The material after the adhesive application step is subsequently subjected to a final laminating step. Examples of the resin film to be laminated include cellulose diacetate, cellulose triacetate, polyvinyl chloride, alcohol, polyvinyl alcohol, polyethylene, polyethylene terephthalate, polypropylene, nylon, acetate and triacetate. The thickness of the resin film is 1
The range of 0 to 500 μm is preferable, and 50 is more preferable.
The thickness is up to 250 μm, and not limited to a flat sheet shape, a three-dimensional pattern such as embossing or a flat pattern such as a group (wavy, hairline) formed on the surface in advance can be used. Lamination is carried out by a method in which a resin film is pressure-bonded to the adhesive-coated surface, and the temperature condition at this time is set to a low temperature range of 100 to 170 ° C. A preferred temperature range is 110 to 165 ° C. This temperature range utilizes the plate temperature residual heat at the time of drying the adhesive in the previous step, but it does not matter if the resin film is heated, or both may be used together. The crimping operation is usually 1 to 1 using a pressure roll.
Set to the pressure condition of 0 kg / cm ² . By using a pressure roll with a three-dimensional pattern or a two-dimensional pattern formed on the surface,
A predetermined pattern can be formed on the flat film surface at the same time as the pressure bonding process.

[0016]

In the method for producing a laminated plate according to the present invention, the material is sequentially subjected to the surface treatment step, the undercoat coating step, the adhesive application step and the laminating step, of which an important configuration different from the prior art is particularly important. Is that an undercoating coating step is interposed between the surface treatment step and the adhesive coating step, and the heating and pressure bonding conditions in the laminating step are performed in a low temperature range of 100 to 170 ° C. That is, in the undercoat coating step, the undercoat coating film made of a specific resin composition firmly adheres to the surface-treated material surface, and the functional groups of the resin film are also bonded to the resin of the adhesive layer to form an integrated and stable coating. Performs the function of forming a fixed layer. Moreover, since this undercoat maintains excellent adhesion even if it contains a rust preventive pigment, it is not necessary to add an rust preventive pigment which impairs the adhesion performance to the adhesive unlike the prior art. Therefore, the adhesive layer exerts its original adhesive force and firmly adheres to the resin film.

The above-mentioned function of improving the adhesiveness works effectively in order to enable the pressure bonding in the laminating step in the operation in the low temperature range of 100 to 170 ° C. The pressure bonding in the low temperature range reduces workability and equipment load, and effectively prevents the design return phenomenon of the laminated film having the surface pattern.

On the basis of such an action, a high degree of adhesion and corrosion resistance which never return to the design are imparted throughout the entire process, and the laminate does not cause peeling or blistering even after long-term use. It becomes possible to manufacture boards.

[0019]

EXAMPLES Examples of the present invention will be described in detail below in comparison with comparative examples.

Examples 1 to 16 and Comparative Examples 1 to 11 The materials (compounding amounts are all solid parts by weight) and steps shown in Tables 1 to 4 (Examples) and Tables 5 to 7 (Comparative Examples) were applied. Thus, a laminated plate in which each material was coated with a resin film was manufactured. However, celloace, propylene glycol monomethyl ether acetate, and propylene glycol monomethyl ether were used as the solvent of the undercoat paint, and xylol was used as the solvent of the polyisocyanate crosslinking agent. A bar coater was used in the undercoat coating process, and baking was performed in a gas furnace. The adhesive coating process was performed using a bar coater (Examples 13 and 14).
In Comparative Examples 8 and 9, a die coater was used. Also,
The laminating process was performed under the pressure bonding condition of about 2 to 5 kg / cm ² using a pressure roll.

Each of the obtained laminated plates was tested for adhesion, design reversion, corrosion resistance, durability and peeling with time by the following measuring methods, and the respective evaluation results are shown in Tables 1 to 7. (1) Adhesion By the cross-cut Erichsen method, cut in the shape of # with a knife on the surface of the laminated film at 5 mm intervals,
After extruding 8mm using an Erichsen tester,
The following criteria were used to evaluate the position at which the coating film was cut after being forcibly peeled from the cut portion. 5 ... No peeling 4 ... 1/4 peeling 3 ... 1/2 peeling 2 ... 3/4 peeling 1 ... All peeling

(2) Design return Visually observe the embossed state of the sheet before and after lamination,
The following criteria evaluated. 5 ... No difference in embossed state before and after lamination 3 ... Embossed pattern is thinned by about 50% after laminating 1 ... Embossing remaining after laminating is erased to about 10%

(3) Corrosion resistance According to JIS-K5400-9.1 (salt spray). However, the test piece was subjected to cross-cutting and bending 2T at the upper end portion (bending by sandwiching two identical plates of the test piece to be bent) and then subjected to the test. Cross cut and bend 2T
The parts were observed together and evaluated according to the following criteria. 5… White rust and red rust did not occur 4… 5% or less of white rust and red rust occurred 3… 10% or less of white rust and red rust 2… 40% or less of white rust and red rust 1… 50% or more The entire surface is covered with white rust and red rust

(3) Durability According to JIS K5400-9.8.1 (Sunshine Weatherometer), parallel cuts at 2 mm intervals were made on the surface of the film after 5000 hours at a length of 2 cm, and the coating film was cut with a knife. The following criteria were used to evaluate the peeling caused by awakening. 5 ... No peeling 4 ... Peeling when pulled strongly 3 ... Peeling to the extent that the coating film is raised with a knife

(4) Peeling with time A # -shaped cut is made at intervals of 5 mm by a cutter, and the cut portion is extruded by 8 mm by an Erichsen tester. This was immersed in boiling water for 12 hours, and further immersed in water at 20 ° C. for 12 hours. This cycle was repeated 3 times, and then it was forcibly peeled from the cut portion with a knife, and the position where the coating film was cut was evaluated according to the following criteria. 5… No peeling 4… Peeling within 1 mm 3… Peeling within 3 mm 2… Peeling within 5 mm 1… Peeling over 5 mm

[0026]

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

[Table 7]

The chemicals, resins, types of rust preventive pigments, trade names, etc. shown in Tables 1 to 7 are as follows. Name of surface treatment agent Zinc phosphate of Examples 1 and 11 and Comparative Examples 1 and 6: Surfdyne 46N-31 manufactured by Nippon Paint Co., Ltd. Zinc phosphate of Examples 2-7, 12-15 and Comparative Examples 2, 7-10: Surfdyne ZS9100 manufactured by Nippon Paint Co., Ltd. Coating type chromate of Example 8 and Comparative Example 3: Surfcoat NRC400 manufactured by Nippon Paint Co., Ltd. Chromate phosphate of Example 9 and Comparative Example 4: Surfcoat NRC500 manufactured by Nippon Paint Co., Ltd. Chromate phosphate in Example 10 and Comparative Example 5: Alsurf 407/47 manufactured by Nippon Paint Co., Ltd. Chromate system of Example 16: Alsurf 1200, manufactured by Nippon Paint Co., Ltd.

Resin of Undercoat Paint Epoxy resin of Examples 1 and 10: Phenocote YD7011 (Epoxy equivalent 460 to 490) manufactured by Tohto Kasei Co., Ltd., used as a 40% butyl carbitol solution. Epoxy resins of Examples 2 to 7: Phenocote 7014 (epoxy equivalent 940 to 960) manufactured by Tohto Kasei Co., Ltd., 40% butyl carbitol solution was used. Epoxy resins of Examples 8 and 13: Toto Kasei Co., Ltd.
Made by Fenocoat 7017 (Epoxy equivalent 1750-21
00), using a 40% butyl carbitol solution. Acrylic resins of Examples 8 and 10 to 14: Mitsubishi Rayon Co., Ltd.
Made by DIANER LR-269 (Mw 30000-1500)
00, NV 30%). Polyester resin of Example 9: Byron 63-CS (Mn 20000-250000, NV33, manufactured by Toyobo Co., Ltd.)
%). Polyester resin of Example 11: Byron GK59CS (Mn 5000-8000, NV50, manufactured by Toyobo Co., Ltd.)
%). Phenoxy resin of Example 12: Phenotote YP-50 PK-35 (Mn 12000, NV 35%, O manufactured by Toyobo Co., Ltd.)
H equivalent 286). Epoxy resin of Example 14: Phenotote YU-100 (epoxy modified polyol OH-V15, manufactured by Tohto Kasei Co., Ltd.)
0-200, NV 99.5%). OH-V150-200, NV99.5%).

Crosslinking Agent for Undercoat Resin Blocked Isocyanates of Examples 1-10, 12, 15-16:
Nippon Polyurethane Co., Ltd., Coronate 2515 (NV8
0%). Melamines of Examples 8, 10, 13-14: Mitsui Toatsu Chemicals, Inc.
Uban 20SE-60 (Butylated melamine NV60)
%). Melamine of Examples 11 to 12: Nikalac MW-24X (methylated melamine NV 80%) manufactured by Sanwa Chemical Co., Ltd. Isocyanates of Examples 13-14: Nippon Polyurethane Co., Ltd., Coronate L (NV 75%).

Anticorrosion Pigment PV system used in Example 6: Magnesium orthophosphate [Mg ₃ (PO ₄ ) ₂ ] and CaO.V ₂ O ₅ calcined product were mixed with P ₂ O ₅ /
V ₂ O ₅ was mixed in a molar ratio of 1/1 and 3 in a mortar
After mixing for 0 minutes, put in a crucible and transfer to an electric furnace.
Baking is performed at a temperature of 0 ° C. for 2 hours. Then, a phosphorus-vanadine-based rust preventive pigment obtained by rapidly cooling the melt in the crucible at a cooling rate of 500 ° C / min, pulverizing and classifying. PV system used in Example 7: P ₂ O ₃ and 4MnO.V ₂ O
_{5 The} fired product was blended so that the molar ratio of P ₂ O ₅ / V ₂ O ₅ was 1/1, mixed in a mortar for 30 minutes, placed in a crucible and transferred to an electric furnace, and fired at a temperature of 1200 ° C. for 2 hours. To process. Then, a phosphorus-vanadium-based rust preventive pigment obtained by cooling the melt in the crucible at a cooling rate of 300 ° C./min, pulverizing and classifying.

Adhesive Resins Examples 1, 8-9, 15-16, Comparative Examples 1, 3-4, 10-11
Urethane resin: Power Paint, manufactured by Nippon Paint Co., Ltd.
U-40 (polyisocyanate crosslinker). Acrylic resins of Examples 2 to 7 and Comparative Example 2: Power Tight A-10 (polyisocyanate / manufactured by Nippon Paint Co., Ltd.)
Melamine-based crosslinking agent). Epoxy / amine of Example 10 and Comparative Example 5: Power Tight E-30 A / B manufactured by Nippon Paint Co., Ltd. Polyester resin of Example 11 and Comparative Example 6: Power Tight P-50 (polyisocyanate crosslinking agent) manufactured by Nippon Paint Co., Ltd. Polyolefin resin of Example 12 and Comparative Example 7: Power Tight O-60 manufactured by Nippon Paint Co., Ltd. Polyamide resin of Example 13 and Comparative Example 8: Power Tight N-70 manufactured by Nippon Paint Co., Ltd. Acrylic resin of Example 14 and Comparative Example 9: Power Tight A-10 manufactured by Nippon Paint Co., Ltd.

Film Resin for Laminating Polyvinylidene chloride resin of Example 1 and Comparative Example 1: Saran UB (embossed product) manufactured by Asahi Kasei Corporation. Polyvinylidene chloride of Examples 2 to 7 and Comparative Example 2: Kenoflex (embossed product) manufactured by Kureha Chemical Industry Co., Ltd. Example 8, Comparative Example 3 Polyethylene resin: Hypron film H (embossed product) manufactured by Mitsui Toatsu Chemicals, Inc. Polyethylene resin of Example 9 and Comparative Example 4: Toyobo Co., Ltd., Rix film (embossed product). Polypropylene resins of Example 10 and Comparative Example 5: Toray Industries, Inc.
Made by Trefan (embossed product). Polyvinyl chloride resin of Examples 11, 14, 16 and Comparative Examples 6, 9, 11: Riken film (embossed product) manufactured by Riken Vinyl Industry Co., Ltd. Nylon of Example 12 and Comparative Example 7: Emblem (embossed product) manufactured by Unitika Ltd. Polyester resins of Example 13 and Comparative Example 8: Toray Industries, Inc.
Made, Lumirror (embossed product). Acrylic resin of Example 15 and Comparative Example 10: Acryprene manufactured by Mitsubishi Rayon Co., Ltd.

As can be seen from the results shown in Tables 1 to 7, the laminates produced according to the examples of the present invention are excellent in adhesion, corrosion resistance and durability, and at the same time do not cause design return or peeling with time. However, it was not possible to produce a laminate having satisfactory performance in the comparative example in which the undercoat coating process of the present invention was not performed.

[0034]

As described above, according to the present invention, by applying the respective steps of surface treatment, undercoat coating, adhesive coating and laminating, design return or the like can be performed depending on the pressure bonding condition in the lower temperature range than in the prior art. Excellent adhesion and corrosion resistance can be imparted without causing a phenomenon, and it becomes possible to manufacture a high-quality laminated plate that does not cause peeling or blistering over time. Therefore, it is useful as an industrial manufacturing technique for a laminated plate that is extremely durable even when used in a corrosive environment.

Claims (1)

[Claims] 1. A method for manufacturing a laminate, which comprises sequentially applying the following steps. (1) At least 1 of cleaning, activation or chemical conversion to the material
Surface treatment process that performs two treatments. (2) An epoxy-based, epoxy / acrylic-based or polyester-based resin and a cross-linking agent as main components, and any undercoat paint containing a rust preventive pigment was applied to the material to form a dry coating film of 1 to 20 μm. Subbing coating process for baking afterwards. (3) Acrylic, rubber, epoxy, urethane, polyester, olefin or amide resin 1
100 to 100% by applying an adhesive containing a cross-linking agent as a main component by one kind or two or more kinds, if necessary, to the undercoat coating film surface.
Dry film thickness of 1 to 20 μm by heating to a plate temperature range of 170 ° C
Adhesive application step of forming the adhesive layer of. (4) A laminating step in which a resin film is pressure-bonded to the adhesive-coated surface in a temperature range of 100 to 170 ° C.