JPH01188331A - Manufacture of precoated composite vibration damping steel sheet - Google Patents

Abstract

PURPOSE:To obtain a composite vibration damping steel sheet whose vibration damping properties and shearing strength are favorable without generating deterioration in durability of a coated surface, by a method wherein precoated steel sheets are bonded with pressure by heating at the curing temperature or higher of a resin solution and a specific temperature or lower by feeding a synthetic resin solution obtained by adding isocyanate to a solution containing a specific quantity or more of polybutadiene diol between the precoated steel sheets. CONSTITUTION:A synthetic resin solution 3 obtained by adding isocyanate to a solution containing at least 30wt.% polybutadiene diol, which is a main ingredient, as a crosslinking agent is applied to the surfaces of precoated steel sheets 1 where resin coatings have been formed on both sides by an applicator device 2. The precoated steel sheet 1 to which the resin solution 3 have been applied is heated by a heating furnace 4 at a temperature of the curing temperature of the resin solution or higher and 150 deg.C or lower. Press bonding of the precoated steel sheets 1 to each other is performed by a laminating roll 5 so that surfaces of them coated with the resin solution abut against each other and high-temperature vibration damping steel sheet is cooled by spraying water over the high-temperature vibration damping steel sheet with a cooling device 6. Water is squeezed by a squeeze rolls 7, recorrection of a form is performed and a composite vibration damping steel sheet is wound up in a state of a coil by a tension reel 8.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a composite vibration-damping steel plate with excellent durability and bendability that can effectively prevent vibrations generated from machinery, etc., and is coated with resin on both sides in advance. The present invention relates to a method for manufacturing a pre-coated composite damping steel plate that can be manufactured using a pre-coated steel plate on which a coating film has been formed.

[Conventional technology]

In recent years, with the tightening of noise regulations for automobiles, etc., various methods are being considered as countermeasures. Composite vibration-damping steel plates laminated with polymeric materials rich in carbon dioxide have been used to great effect.

The use of such composite damping steel plates in housing components for the purpose of noise and vibration prevention is also being considered.

Examples of highly viscoelastic polymeric substances used between the two steel plates of such a composite damping steel plate include coated acrylic rubber resins, polyvinyl chloride resins, and polyethylene resins. Thermoplastic films such as polypropylene resin modified with acrylic resin and polypropylene resin/synthetic rubber are used, and these various viscoelastic polymeric substances are sandwiched between two steel plates to form composites. In order to continuously manufacture die vibration damping steel plates,
A method is to apply a polymeric substance onto one steel strip and laminate the other copper strip on top of it, or a method in which a polymeric substance is applied to two copper strips at the same time and the coated surfaces are overlapped and laminated. 2 methods and polymeric materials pre-formed in sheet form.
There is a method of laminating the material by continuously supplying it between two steel strips.

[Problem to be solved by the invention]

However, the above-mentioned polymeric substances require high temperatures to form a film, and thermoplastic films have a high melting point, so high temperatures are required to bond them. In order to improve the adhesion between the two steel plates and the polymer material and obtain uniform adhesive strength over the entire surface, it is necessary to reheat the steel plates in a heating furnace to raise the surface temperature of the laminating roll. It is necessary to laminate the steel plate and the polymer material by increasing the height.

As a result, when a pre-coated steel plate with a resin coating film pre-formed on one side is used as two steel plates, the pre-coated steel plate will be exposed to high temperatures, so the corrosion resistance of the painted surface of the pre-coated steel plate after lamination with a polymeric material will be affected. There were issues that needed to be resolved, such as not only a decrease in adhesion but also a blocking phenomenon that occurred during winding of the payoff reel during continuous production, making it impossible to manufacture composite vibration damping steel sheets with good properties. .

[Means to solve the problem]

In order to solve these problems, the inventors of the present invention conducted extensive research and found that the polymer material with high viscoelasticity that constitutes the intermediate layer of the composite damping steel sheet has a low curing temperature, but has poor adhesion to the pre-coated steel sheet. If you use a resin with an excellent specific composition, supply this resin liquid between the pre-coated steel plates, heat it to a temperature above the curing temperature of the resin liquid and below 150°C, immediately press it with a laminating roll, and then cool it. The resin with this specific composition is usually a solution containing 30% by weight or more of polybutadiene diol as the main component, and hydroxides such as polyethylene glycol, polypropylene glycol, aromatic diols, and esters such as dioctyl phthalate as other remaining components. The present invention was completed by determining that a synthetic resin solution in which an isocyanate such as methane diphenyl isocyanate is added as a crosslinking agent to a composition formed with the above components is optimal.

That is, the present invention involves supplying a synthetic resin solution in which isocyanate is added as a crosslinking agent to a solution containing 30% by weight or more of polybutadiene diol between pre-coated steel sheets with resin coatings formed on both sides, and curing the resin solution. After heating to a temperature of 150°C or higher.

The present invention relates to a method for manufacturing a precoated composite vibration damping steel sheet, which is characterized in that it is immediately crimped using a laminating roll and then cooled.

EMBODIMENT OF THE INVENTION Hereinafter, the manufacturing method of the precoated composite damping steel plate based on this invention is demonstrated in detail with reference to drawings.

FIG. 1 is an explanatory diagram showing an outline of the method for manufacturing a pre-coated composite vibration-damping steel plate according to the present invention, and FIG. 2 is a cross-sectional view schematically showing the structure of a pre-coated composite vibration-damping steel plate manufactured by the method of the present invention. It is.

In the drawing, reference numeral 1 denotes a pre-painted steel plate constituting both sides of a pre-painted composite damping steel plate, and this pre-painted steel plate 1 is one side of a steel plate A such as a cold-rolled steel plate, a hot-dip galvanized steel plate, a hot-dip aluminized steel plate, or a stainless steel plate. That is, on the surface opposite to the surface to be bonded, a pretreatment layer B is formed by a pretreatment such as phosphate treatment 9, reactive chromic acid treatment, or coating type chromic acid treatment, and then a layer of epoxy resin or the like is applied. After or without applying the base coat layer C, a thermosetting resin paint such as epoxy resin, acrylic resin, polyester resin, silicone polyester resin, etc., or thermoplastic paint such as polyvinyl chloride resin, fluororesin, etc. A resin-based paint is applied and baked in advance to form a surface coating layer, and the opposite side, the side to be bonded, is treated with phosphate.

A material in which a pretreatment layer E is formed by a pretreatment such as a reactive chromic acid treatment or a coating type chromic acid treatment is used. 2 is a synthetic resin solution 3 prepared by adding isocyanate as a cross-linking agent to a solution containing 30% by weight or more of polybutadiene diol on the opposing surfaces of the pre-coated steel sheet 1 to form a polybutadiene-based resin between the opposing surfaces of the pre-painted steel sheet 1. a coating device for forming a synthetic resin film F; 4
5 is a heating furnace that heats the pre-coated steel sheets 1 coated with a synthetic resin liquid 3 on opposing surfaces to a temperature above the curing temperature of the synthetic resin liquid 3 and below 150°C; 7 is a cooling device that sprays water to cool the still-hot composite damping steel plate formed by crimping with the laminate roll 5; A drawing roll squeezes moisture out of the composite damping steel plate that has passed through the cooling device 6 and corrects its shape, and 8 is a tension reel that winds up the composite damping steel plate that has passed through the drawing roll 7.

[For production]

In order to produce a pre-coated composite vibration damping steel plate by the method of the present invention, as shown in FIG. On the opposite side of the surface,
Phosphate treatment 2) After pretreatment such as chromic acid treatment or coating type chromic acid treatment, epoxy resin type, acrylic resin type, etc. can be applied after or without applying a base coat such as epoxy resin type. Polyester resin type.

A thermosetting resin paint such as a silicone polyester resin paint or a thermoplastic resin paint such as a polyvinyl chloride resin paint or a fluororesin paint is applied and baked in advance, and the opposite side, that is, the side to be bonded, is coated with a phosphor. Acid treatment 9 A pre-coated steel sheet 1 that has been pre-treated such as a chromic acid treatment or a coating-type chromic acid treatment is prepared, and polybutadiene diol, which is the main component, is applied to opposing surfaces of the pre-coated steel sheet 1. Adding an isocyanate such as methane or diphenyl isocyanate to a solution containing 30% or more of The synthetic resin liquid 3 added as a crosslinking agent was applied by the coating device 2, and then the pre-coated steel plate 1 coated with the synthetic resin liquid 3 was heated in the heating furnace 4 to a temperature above the curing temperature of the synthetic resin liquid 3 and below 150°C. Thereafter, water is sprayed by a cooling device 6 to cool the composite damping steel plates, which are still at high temperature, by pressing the pre-coated steel plates 1 together with a laminating roll 5 so that the surfaces coated with the synthetic resin liquid 3 are in contact with each other.

After that, the cooling device! 6, the water is squeezed out from the composite vibration damping steel plate by a squeeze roll 7, the shape is corrected, and the composite vibration damping steel plate is wound into a coil shape by a tension reel 8. As shown in FIG. Surface coating layer, base coat layer C2 pretreatment layer B, steel plate A, pretreatment layer E, polybutadiene-based synthetic resin film F, pretreatment layer E
, steel plate A.

The production of the precoated composite damping steel sheet on which the pretreatment layer B and the base coat layer C2 are formed is completed.

〔Example〕

Examples and comparative examples will be described in detail below.

Examples 1-6. Comparative Examples 1 to 16 On one side of a hot-dip galvanized steel sheet with a thickness of 0.27 mm, an epoxy resin coating film of 5p was formed as a base coat layer, and a thermosetting resin coating film of 15% polyester resin coating was formed on top of it as a surface layer. Pre-painted steel plate and plate thickness 0.27mm
A pre-coated steel plate is prepared by forming an epoxy resin coating 5- as a base coat layer on one side of a hot-dip galvanized steel plate, and further forming a vinyl chloride resin coating 200 g thick thermoplastic resin coating as a surface layer thereon, After applying a coating type pre-treatment to the opposite side, the opposing surfaces of the pre-coated steel plates with a thermosetting resin coating formed thereon, and the mutually opposing surfaces of the pre-coated steel plates with a thermoplastic resin coating formed thereon. On the opposite side, 37% by weight polybutadiene diol.

27% by weight of polypropylene glycol, 9% by weight of dioctyl phthalate, 23% by weight of aromatic glycol ether
A synthetic resin solution prepared by adding 30 parts by weight of methanediphenyl isocyanate as a crosslinking agent to 100 parts by weight of a solution containing 4% by weight of aromatic glycol was coated to a thickness of 0.5% by weight.
05+on+ resin coating formed (Example 1~
3,4-6), polypropylene 10/a and synthetic rubber 60
．． and polypropylene 10- (Comparative Examples 1-3゜9-11), and 50% thick polyester elastomer (Comparative Examples 4-5).
, 12-13), polypropylene 6- and rosin rubber 50
Comparative Examples 6 to 8 and 14 to 16 were manufactured by laminating rosin rubbers having a three-layer structure of No. 4 and 61 m of polypropylene.

Here, the manufacturing method of the products of each example is the manufacturing method described above, and the manufacturing method of the product of the comparative example is to pull out the above-mentioned pre-painted steel sheets from two payoff reels, preheat them in a heating furnace, and heat-press them. At the same time, the two pre-painted steel sheets are overlapped in the roll section, and the resin serving as the core material is inserted into each sheet, heated and pressed using a laminating roll to a temperature above the melting point of the resin, and then cooled with a cooling device.
This was done by performing correction with a squeeze roll and winding it up on a tension reel. The manufacturing conditions at that time were as follows.

Manufacturing conditions of Examples 1 to 6 Plate surface temperature on exit side of heating furnace 90 to 100°C Surface temperature of pressure roll 100 to 140°C Pressure force of pressure roll
1.5kg/a #Heating furnace passing time 90 seconds Manufacturing conditions of Comparative Examples 1 to 3 and 9 to 11 Plate surface temperature on exit side of heating furnace 150 to 190°C Surface temperature of pressure roll 160 to 200°C Pressure force of pressure roll
4.5 kg/cd Heating furnace passage time 90 seconds Manufacturing conditions of Comparative Examples 4 to 5, 12 to 13 Plate surface temperature on outlet side of heating furnace 180 to 200°C Surface temperature of pressure roll 200 to 210°C Pressure force of pressure roll
4.5kg/an? Heating furnace passage time 90
Manufacturing conditions for Comparative Examples 6 to 8 and 14 to 16 Plate surface temperature on exit side of heating furnace 170 to 200°C Surface temperature of pressure roll 190 to 210°C Pressure force of pressure roll
4.5 kg/a #Heating furnace passage time: 90 seconds The shear strength between the vibration damping two pre-coated steel plates and the durability of the painted surface before and after lamination of the various composite vibration damping steel plates thus obtained were evaluated using the following criteria. did.

(1) Vibration damping property A non-contact type vibrator is used at the free end of a suspended specimen with a length of 200 mm and a width of 15 mm, and a cantilever resonance method is used to apply forced vibration using electromagnetic attraction force, resulting in a loss factor η. was measured. The evaluation method is 0 ''Loss coefficient η''' is 0.1 or moreΔ ''Loss coefficient η'' is 0.05 or more and less than 0.1X''
Loss coefficient η'' is less than 0.05 (2) Shear strength Measured by conducting a tensile test on a resin layer with a lap width of 10 mm between pre-coated steel plates with a width of 25 mm using a 2-ton capacity Amsler type tensile tester.Method for evaluation. Q Shear strength is 100 kgf/af or more Δ Shear strength is 70 kgf/aJ or more and less than 100 kgf/Ci Rust and blisters on the surface of the paint film were observed in the testing machine. The evaluation method was: 011 Rust, no blisters Δ 11 Rust, small blisters . The evaluation method is O "No rust or blisters" Δ "Small rust or blisters" The test was conducted.

Table 1 Test conditions The change in gloss was measured by measuring the specular reflectance at 60 degrees.
The gloss retention rate was determined by comparing with the specular reflectance. In addition, the color change was determined by measuring the color difference from the unirradiated test piece and determining ΔE.

The evaluation method is 0 Color difference (ΔE) 1.0-2.5 Gloss retention rate 80% or more Δ Color difference (ΔE) 2.5-4.3
Gloss retention rate 60% or more x Color difference (ΔE) 4.3 or more Gloss retention rate less than 60% Among the various composite vibration damping steel plates mentioned above, vibration damping properties when the pre-coated steel plate is composed of a thermoplastic resin coating film 1 Table 2 shows the test results for the shear strength between both pre-painted steel plates and the durability of the painted surface before and after lamination.

Table 3 shows the test results for the shear strength between the nine pre-coated steel plates and the durability of the painted surface before and after lamination.

In the test results shown in Tables 2 and 3, in the composite damping steel plate, shear deformation occurs in the viscoelastic material sandwiched between the steel plates on both sides, which converts vibration and noise energy into heat energy. It is said that the vibration damping effect and soundproofing effect are exhibited by the loss coefficient η, and the loss coefficient η is generally 0.
A steel plate with a loss coefficient η of 1 or more can be said to be a composite damping steel plate.

In addition, the shear strength between the drawing boards, which is one indicator of workability, varies depending on the shape of the drawing, but is generally 100 kgf.
It is said that /alf or higher is required. Considering the test results shown in Tables 2 and 3 from this perspective, when the pre-coated steel sheets shown in Table 2 are composed of a thermoplastic resin coating, the composite vibration damping steel sheets are as follows: When the lamination temperature is between 100 and 140°C (Examples 1 to 3), both vibration damping properties and shear strength are good, and BBT and S in the durability test are good.
Even in ST, there was no rust or blistering on the coating surface, and no difference in color difference (ΔE) or gloss retention was observed compared to the coating surface before lamination.

On the other hand, when the viscoelastic resin layer was a three-layer film, when the lamination temperature was the lowest at 160° C. (Comparative Example 1), the vibration damping properties were good but the shear strength showed a low value.

The reason for this is that the melting point of polypropylene resin is 155
The difference between the lamination temperature and the lamination temperature was only 5 °C, and it is thought that the adhesion did not improve because the lamination was performed in a semi-molten state. This means that when the viscoelastic resin layers are the same three-layer film and the lamination temperature is 25°C and 45°C higher than the melting point of the polypropylene resin (Comparative Examples 2 and 3), not only vibration damping properties but also shear strength are good. I can't stand it. In addition, the viscoelastic resin layer that is the core material is made of polyester elastomer (Comparative Examples 4 and 5)
In the case of rosin rubber (Comparative Examples 6 to 8), the vibration damping properties are good at each lamination temperature, but the shear strength shows a slightly low value at a lamination temperature of 200 ° C when the viscoelastic resin layer is a polyester elastomer. - In addition, when the viscoelastic resin layer was made of rosin rubber, the results were good at all lamination temperatures.

However, it is necessary to increase the lamination temperature of the three types of viscoelastic resin layers in the comparative example due to their melting points.

As a result, the surface of the precoated steel sheet is exposed to high temperatures in the heating furnace and on the surface of the pressure roll (heating roll). Rust and blistering of the paint film were observed in the cut and edge areas, and the color difference (ΔE
) and gloss retention were both found to be significantly inferior compared to the coating surface before lamination.

In addition, the test results of the shear strength between the nine pre-coated steel plates and the durability of the painted surface before and after lamination show the vibration damping properties when the pre-coated steel plates shown in Table 3 are made of a thermosetting resin coating. Similar to the test results, the viscoelastic resin layer that is the core material is a synthetic resin liquid obtained by adding isocyanate as a crosslinking agent to a solution containing 30% by weight or more of polybutadiene diol, and the lamination temperature is the curing temperature of this resin liquid ( 100°C) or higher and 150°C or lower for 90 seconds (Example 4)
-6) have good vibration damping properties and shear strength, and there is no rust or blistering on the coating surface in the BBT and SST durability tests, and the color difference (ΔE) and gloss retention are also the same as before lamination. No difference was observed between the two surfaces.

On the other hand, when the viscoelastic resin layer that is the core material is a three-layer film (
Comparative Examples 9 to 11), in the case of polyester elastomer (
Comparative Example 12.13) and rosin rubber (Comparative Example 14)
~16) However, it is necessary to raise the lamination temperature due to the melting point of the elastic resin layer, and as a result, the surface of the pre-coated steel sheet is exposed to high temperatures in the heating furnace and on the surface of the pressure roll (heating roll), resulting in poor durability. BBT test and SS in sex test
In the T test, rust and blistering of the paint film were observed in the parts bent to a radius of curvature twice the board thickness, cross-cut parts, and edge parts, and the color difference (ΔE) and gloss retention were both lower than that of the paint film surface before lamination. was found to be significantly inferior to that of

〔Effect of the invention〕

As detailed above, the method for producing a pre-coated composite vibration damping steel sheet according to the present invention uses 30% by weight of polybutadiene diol as a resin liquid supplied between pre-coated steel sheets with resin coatings formed on both sides. A synthetic resin liquid containing isocyanate as a crosslinking agent is used in the above-mentioned solution, and the heating temperature for adhering the resin liquid to the pre-coated steel plate is set to a temperature higher than the curing temperature of the resin liquid and lower than 150°C. By doing so, the durability of the painted surface of the pre-coated steel plate after laminating the viscoelastic resin layer serving as the core material on the pre-coated steel plates on both sides does not decrease, and the composite vibration damping material has good vibration distribution properties and shear strength. Since it becomes possible to manufacture steel plates, it becomes possible to supply raw materials not only for exterior building materials but also for products that are bent into various shapes and used for anti-vibration purposes, and its industrial value is extremely large. be.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an outline of the method for manufacturing a pre-coated composite vibration-damping steel plate according to the present invention, and FIG. 2 is a cross-sectional view schematically showing the structure of a pre-coated composite vibration-damping steel plate manufactured by the method of the present invention. It is. In the drawing, 1...Pre-coated steel plate 2...Coating device 3...Synthetic resin liquid 4...Heating furnace 5...Laminating roll 6...Cooling device 7... - Squeezing roll 8... Tension reel A... Steel plate B... Pre-treatment layer C... Base coat layer D... Surface coating layer E... Pre-treatment layer

Claims (1)

[Claims] 1. A synthetic resin solution prepared by adding isocyanate as a crosslinking agent to a solution containing 30% by weight or more of polybutadiene diol is supplied between pre-coated steel plates with resin coatings formed on both sides, and the temperature is set at a temperature above the curing temperature of the resin solution and below 150°C. A method for manufacturing a pre-coated composite damping steel sheet, which comprises heating the steel sheet to a certain temperature, immediately crimping it using a laminating roll, and then cooling it.