JPH01288367A - Preparation of vinyl chloride coated steel plate having high hardness and excellent dent resistance - Google Patents

Abstract

PURPOSE:To improve dent resistance and bleeding resistance by coating a steel plate with a plastisol prepared by compounding a vinyl chloride polymer powder having two-peak type particle size distribution and an acrylic polymer powder having a specific particle size. CONSTITUTION:A plastisol is prepared by compounding 100pts.wt. of a vinyl chloride polymer powder having two-peak type particle size distribution wherein 95wt.% or more is 0.5-40mum in a particle size and 20-60wt.% is 0.5-below 5mum and 35-75wt.% is 5-40mum and there are two peaks at 1-3mum and 8-15mum, 5-60pts. wt. of an acrylic polymer powder wherein 95wt.% or more is 0.1-40mum in a particle size and an average polymerization degree is 500-30,000 and 5-60pts.wt. of a thermosetting monomer or oligomer. This plastisol is applied to the surface of a steel plate to form a film which is, in turn, gelled under heating to obtain a vinyl chloride coated steel plate having high hardness and excellent dent resistance.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides high hardness, indentation resistance, and bleed resistance (plasticizer).
The present invention relates to a method for manufacturing a vinyl chloride-coated steel sheet that has excellent workability and a matte surface effect.

[Conventional technology]

Vinyl chloride-coated mW has excellent properties such as workability, corrosion resistance, weather resistance, and design, so it has been widely used for interior building materials, exterior building materials, electrical equipment, vehicles, and miscellaneous goods.

There are two main methods for manufacturing PVC-coated steel sheets: the plastisol method and the lamination method. However, the plastisol method is widely used because it can quickly deliver to users and efficiently produce a wide variety of products in small quantities. has been done. In the plastisol method, plastisol containing polyvinyl chloride resin, plasticizers, stabilizers, pigments, and various additives is applied to a steel plate via an adhesive layer, and the coating is heated to gel. Manufactured with predetermined embossing.

However, the vinyl chloride-coated steel sheet manufactured by the 1-lastisol method has a soft film inside the shell, and its properties such as hardness, indentation resistance, and bleed resistance are inferior, and the surface matting effect is not sufficient. In other words, the plastisol-processed vinyl chloride-coated steel sheet is highly evaluated for its design because it is possible to apply desired embossing to the surface of the film immediately after forming a gel film by heating during manufacturing. However, when large pressure is applied to the surface of the film while it is loaded in a coiled state or a cut plate state and shipped to a user, the embossed pattern tends to be crushed, causing problems in indentation resistance, and the plasticizer in the film tends to migrate to the surface, causing problems in bleed resistance.

As a way to improve the shortcomings of these plastisol methods, studies have been conducted on plastisols with a viscosity that allows coating with low plasticizers, from the viewpoint of selecting the vinyl chloride resin powder or plasticizer used, and using diluents. . However, there are limits to the improvement of characteristics. If plastisol with a low plasticizer is simply used, the viscosity will increase and the paintability will decrease, and although the hardness of the film will increase, it will become brittle and the processability will decrease. If a large amount of diluent is used, the hardness of the film will increase, but the workability will decrease, and blistering will occur on the film surface due to volatilization of the diluent, which is undesirable.Also, it is possible to increase the hardness of the film without reducing the workability. As a method, a plastisol that forms a soft film is applied as the first layer, and then a plastisol that forms a hard film is applied as the second layer. A method has been proposed in which the layer and the second layer are gelled at once, but this method is expensive and also has a limit in film hardness. Therefore, there is a method in which a polymerizable plasticizer that is liquid at room temperature is mixed into plastisol and cured by heating during gelation, or a method in which it is then cured by irradiation with ultraviolet rays (Japanese Patent Publication No. 44-31818, Japanese Patent Publication No. 50-1988) 22580
, Japanese Patent Publication No. 57-9593) have been proposed, but these methods do not provide sufficient hardness, indentation resistance, or bleed resistance of the films obtained, and there are problems with properties such as workability. In addition, in order to make the vinyl chloride film matte, a method of incorporating silica powder into plastisol has traditionally been used, but adding silica powder greatly increases the viscosity of plastisol, making painting work difficult. The obtained film tended to become brittle and its mechanical strength decreased, which was a problem. In addition, a method for producing high-hardness vinyl chloride-coated steel using plastisol whose main components are a specific vinyl chloride polymer powder and acrylic polymer powder (Japanese Patent Application No. 1983-
17147) has been proposed, but this method does not have sufficient properties such as indentation resistance and bleed resistance.

[Problem to be solved by the invention]

As described above, the coating of vinyl chloride-coated steel sheets produced by the plastisol method is generally soft and has drawbacks in various properties.

In order to solve these problems, we have overcome the constraints of plastisol viscosity caused by the manufacturing method to develop vinyl chloride, which has high hardness, excellent indentation resistance, and bleed resistance, as well as excellent processability and a matte surface effect. It is necessary to establish a technology to manufacture coated steel sheets.

[Means to solve the problem]

In order to solve these problems, the present invention aims to continuously and efficiently produce vinyl chloride-coated steel sheets with high hardness, excellent indentation resistance, bleed resistance, workability, and surface matte effect using a plastisol method. Therefore, the present invention aims to provide a method for applying a known adhesive to the surface of a steel plate, baking it by heating, and then applying a vinyl chloride polymer powder having a two-beak particle size distribution and an acrylic adhesive to the surface of the steel plate. The main ingredients are polymer powder and heat-curable or ultraviolet-curable 7-mers or oligomers, and include plasticizers, stabilizers, pigments,
A method in which a plastisol containing a diluent and various additives is applied and then heated to form a gelled film, and immediately after that, the film surface is embossed,
The basic feature is to produce a vinyl chloride-coated steel sheet with high hardness and excellent indentation resistance by irradiating ultraviolet rays after embossing to form a two-layered coating.

The present invention will be explained in detail below.

In the method of the present invention, the steel sheets include cold-rolled steel sheets, galvanized steel sheets, chrome-plated steel sheets, tin-plated steel sheets, nickel-plated steel sheets, lead-plated steel sheets, various alloy-plated or composite-plated steel sheets, multilayer-plated steel sheets, and these plated steel sheets. It is possible to use a steel plate that has been subjected to a chemical conversion treatment such as chromate treatment or phosphate treatment, and can be arbitrarily selected depending on the purpose and use.

In the method of the present invention, a known adhesive containing acrylic resin, polyester resin, epoxy resin, or acrylic rubber as a main component can be used to bond the steel plate and the vinyl chloride coating, and the coating can be applied to the surface of the steel plate. After coating to a thickness of 3 to 10 μm, baking is performed by heating at 160 to 250° C. for 1 minute, followed by application of plastisol.

The vinyl chloride polymer powder used in the method of the present invention includes homopolymer powder of polyvinyl chloride resin produced by an emulsion polymerization method or a microsuspension method with an average degree of polymerization of 500 to 2,500. Vinyl chloride polymer powder obtained by copolymerizing a polymerizable monomer such as ethylene, propylene, vinyl acetate propionate, vinyl stearate, alkyl vinyl ether, vinylidene chloride, diethyl fumarate, methacrylic ester, or Crosslinked polyvinyl chloride resin powder and the like can be used. The particle size of the vinyl chloride polymer powder is 0.5 to 40 μm for 95% by weight or more, 0.5 to less than 5 μm for 20 to 60% by weight, and 5 to 40 μm for 35 to 75% by weight. It is preferable to have a two-peak type particle size distribution of 1 to 3 μm.
It is preferable to have a peak at 8 to 15 μm.

Generally, when producing vinyl chloride-coated steel sheets by the plastisol method, one peak (
However, in the present invention, a vinyl chloride polymer powder having a particle size distribution of 2 peaks as shown in FIG. 1 is preferably used.
If the above powder exceeds 5% by weight, the finish of the plastisol coating surface will deteriorate, which is undesirable.6 Particle size: 0.5~
Less than 20% by weight of 5 μm powder, particle size 5-40 μm
If the powder exceeds 75% by weight, the gelling performance of the plastisol will deteriorate, and a large amount of unmelted vinyl chloride polymer powder will remain in the film, resulting in a decrease in properties, which is undesirable. If the powder with a particle size of 5 to 5 μm exceeds 60% by weight and the powder with a particle size of 5 to 40 μm exceeds 35% by weight, the viscosity of the plastisol increases and a large amount of plasticizer, diluent, etc. is required to make the viscosity coatable. This is not preferable because it requires a high hardness vinyl chloride coated steel sheet.

In addition, the acrylic polymer powder used in the method of the present invention is a fine particle powder manufactured by an emulsion polymerization method or a microsuspension method, and includes homopolymer powder of polymethyl methacrylate, epoxy groups, carboxyl groups, and hydroxyl groups. , a copolymer powder of a methacrylic acid monomer with a functional group such as a methylol group, an alkylamino group, or an amide group, or a polyfunctional vinyl compound such as divinylbenzene, ethylene glycol dimethacrylate, or trimethylolpropane triacrylate. Polymethyl methacrylate copolymer powder etc. which have a crosslinked structure by copolymerization can be used. The degree of polymerization of the acrylic polymer powder is preferably 500 to 30,000. If the average degree of polymerization is less than 500, the processability of the obtained vinyl chloride film at low temperatures will decrease, and the matting effect will not be observed, which is not preferable. Average degree of polymerization is 30
If the particle size exceeds 0.000, the vinyl chloride film will become brittle due to insufficient melting during the heating process, which is not desirable.The particle size of the acrylic polymer powder is preferably 0.1 to 40 μm. If the zero particle diameter is less than 0.1 μm, which is undesirable because it remains after melting, the plastisol viscosity increases, which is undesirable.

Furthermore, the heat-curable or ultraviolet-curable monomer or oligomer used in the method of the present invention is a substance that is liquid at room temperature and has one or more acryloyl group, methacryloyl group, or vinyl group per molecule as a functional group, and is a gelatinous substance. A hardened film is formed by heating during curing or by irradiation with ultraviolet rays. Examples of heat-curable or ultraviolet-curable polymers include monofunctional acrylates such as 2-ethylhexyl acrylate and tetrahydrofurallyl acrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, and pentaerythol. Various polyfunctional acrylates such as tetraacrylate can be used. As the heat-curable or ultraviolet-curable oligomer, various acrylates such as polyol acrylate, polyester acrylate, epoxy acrylate, and urethane acrylate can be used. Moreover, these monomers and oligomers can be used in combination depending on the purpose. Further, as the ultraviolet curing catalyst for these monomers and oligomers, for example, benzoin compounds such as benzoin and benzoin ethyl ether, carbonyl compounds such as benzyl and benzophenone, etc. can be used, and the blending amount is 100% by weight of the monomer or oligomer. 0. 1 to 5 parts by weight is desirable. In addition, various organic peroxides can be used as heat curing catalysts for these seven polymers and oligomers, and the blending amount thereof is preferably 0.1 to 5 parts by weight per 100 parts by weight of monomers or oligomers.
Moreover, these ultraviolet curing catalysts and heat curing catalysts can be mixed and used depending on the purpose.

In the present invention, the ratio of vinyl chloride polymer powder, acrylic polymer powder, and monomer or oligomer in plastisol is 5 to 60 parts by weight of acrylic polymer powder to 100 parts by weight of vinyl chloride polymer powder. It is preferable to blend 5 to 60 parts by weight of an ultraviolet curable monomer or oligomer.If the amount of the acrylic polymer powder and monomer or oligomer is less than 5 parts by weight, the effect of blending the acrylic polymer powder will not be obtained. Even if the amount of monomer or oligomer exceeds 60 parts by weight and 60 parts by weight, respectively, the effect does not improve, but rather the effect of the vinyl chloride polymer powder decreases,
This is not preferable because it reduces embossing properties.

Furthermore, in the method of the present invention, plasticizers, stabilizers, pigments, and various additives can be blended into the plastisol. As the plasticizer, commonly used primary plasticizers and secondary plasticizers such as various phthalate esters, various phosphates, and polybasic acid esters can be used.

Furthermore, pigments, stabilizers, and various additives that are generally used in plastisols can be used.

In the present invention, plastisol having the above-mentioned characteristics is applied to a steel plate with a coating thickness of 30 to 500 μm using an adhesive.
Immediately after gelling the coating film by heating at 210° C. for 1 minute, a predetermined embossing process is applied to the surface of the coating film to produce a vinyl chloride steel plate. Further, in the present invention, after embossing, the surface layer of the coating film is further hardened by irradiating ultraviolet rays to produce a vinyl chloride steel sheet. Coating with plastisol can be done using a knife coater, a roll coater, or a bar coater. Further, as a method for irradiating ultraviolet rays, a mercury lamp, a xenon lamp, a carbon arc lamp, etc. that generate ultraviolet rays in a wavelength range of 200 to 400 μm can be used. In addition, irradiation with ultraviolet rays must be carried out after gelling the coating film and applying the specified embossing process; irradiating ultraviolet rays before gelling the coating film or embossing it may damage the surface layer of the coating film. This is not preferable because it becomes hard and embossability deteriorates.

[Effect]

In the method of the present invention, the main components are a vinyl chloride polymer powder with a two-beak particle size distribution, an acrylic polymer powder with a particle size of 0.1 to 40 μm, and a heat-curable or ultraviolet-curable monomer or oligomer. High hardness and pressure resistance can be achieved by applying plastisol to a steel plate using an adhesive and heating it to form a gel film, and then immediately embossing the film surface, or by further irradiating ultraviolet rays after embossing. It is possible to obtain a vinyl chloride-coated steel sheet that has excellent scratch resistance and bleed resistance, as well as excellent workability and surface matte effect.

The reason for this improvement in properties is that the aforementioned vinyl chloride polymer powder and acrylic polymer powder with a two-beak particle size distribution, as well as ultraviolet curable or heat curable monomers or oligomers, are combined with plasticizers in plastisol. It forms a plastisol with a viscosity that can be coated with a low plasticizer by forming a so-called close-packed state with moderate affinity, and when the plastisol is coated on a steel plate and heated, the vinyl chloride polymer powder and the acrylic polymer are mixed together. This is thought to be because the powder melts and the monomer or oligomer undergoes a polymerization reaction, forming a strong film in which the vinyl chloride polymer powder and the acrylic polymer powder are appropriately compatible. Furthermore, it is conceivable that by irradiating ultraviolet rays after embossing, the ultraviolet curable monomer or oligomer in the upper layer of the film undergoes a polymerization reaction, thereby strengthening the embossed layer on the surface of the film. In other words, when ultraviolet rays are irradiated after embossing, some of the ultraviolet rays are reflected or absorbed by the pigments in the film, so the amount of radiation that reaches the film decreases as it goes deeper into the film. The oligomer is limited to a range of several micrometers to several tens of micrometers from the surface of the film, and as a result, it forms a film with a two-layer structure in which the surface layer is stronger than the inside of the film, improving indentation resistance and bleed resistance. It is thought that these characteristics are further improved.

〔Example〕

The present invention will be explained below using examples.

Example 1 Polymerization degree 165 with a two-peak type particle size distribution in which 30% by weight has a particle size of 0.5 to 5 μm and a peak at 2 μm, and 70% by weight has a particle size of 5 to 40 μm and a peak at 10 μm
95% by weight of polymethyl methacrylate resin powder 15 with a particle size of 0.5 to 5 μm and an average degree of polymerization of 20,000 based on 100 parts by weight of polyvinyl chloride resin powder (manufactured by Tosoh)
100 parts by weight of the mixture mixed with the heavy plate, acrylic oligomer (manufactured by Toagosei Kagaku ■, Aronixt 8060)
1 part by weight of 15 parts by weight, 0.30 parts by weight of organic peroxide (manufactured by NOF ■, Barhexa 3M), 30 parts by weight of dioctyl phthalate, secondary plasticizer (C8-16 made by Chisso ■>10 parts by weight,
After kneading 2 parts by weight of PB stabilizer and 1.5 parts by weight of carbon black using an Ishikawa type stirrer for 10 minutes,
Plastisol was produced by degassing for a minute. The viscosity of the obtained plastisol was measured with a viscometer (manufactured by Tokyo Keiki ■, BM type viscometer rotor No. 4.6 rpm), and the result was 26.
It had zero voids and low viscosity.

Next, a commercially available adhesive mainly composed of acrylic resin was applied to a composite electrogalvanized steel sheet with a thickness of 0.5 mm and a plating amount of 10 g/m'' containing zinc as the main component and cobalt and molybdenum to a thickness of 3 μm. Paint it to 230℃
After heating and baking for 1 minute, the plastisol described above was applied to a coating thickness of 150 μm using a roll coater method.
Immediately after gelling by heating at 210°C for 1 minute, engraving roll (sand Hitachi roll, surface roughness: Ra; 7,
A vinyl chloride-coated steel plate was prepared by embossing the surface layer of the coating film using a polyester resin (45.0 μm).

The coating film appearance of the obtained vinyl chloride coated steel sheet was good;
The hardness of the coating film is measured using a durometer (■ Shimadzu Corporation, Type A
), the result was 94, indicating dura mater. In addition, DuPont impact processing test (1/2 inch φx 1KgX50
As a result of evaluating the workability by cm), no cracking of the coating film was observed even at -5°C, indicating good workability. Also,
The glossiness of the coating surface (60 degree specular reflectance, measured using a variable angle gloss meter UGV-5 manufactured by Suga Test Instruments n) was measured to be 6, indicating a good matting effect. In addition, the embossed state of the coating surface can be measured using a surface roughness meter (Tokyo Seimitsu Model, Surfcom 60).
As a result of evaluation in A), Ra; 3.3) tm, Rsax;
It was 29.6 ttm and had a good embossed state.

In addition, the obtained vinyl chloride coated steel plate was
After cutting the pieces to a size of m, stack several pieces and leave them for 10 days with a weight (3) cg/cd) applied on top of them.
40° C.), the test plate was taken out and the indentation resistance was evaluated by observing the embossed state on the surface of the coating film. As a result, no abnormalities in the embossing were observed, indicating good indentation resistance. In addition, the obtained vinyl chloride coated steel plate was 15×L 5c
After cutting to a size of m, a biaxially stretched polyester film (thickness 20 μm) was sandwiched between the vinyl chloride-coated steel sheets, several sheets were stacked, and a load (10 kg/a11) was applied from above. After leaving it for 10 days (at 50°C), the polyester film in contact with the coating surface of the test plate was observed. As a result, no liquid substance was observed on the surface of the polyester film, indicating excellent bleed resistance. showed his sexuality.

Example 2 100 parts by weight of a mixture of 100 parts by weight of the polymethyl methacrylate resin powder shown in Example 1 to 100 parts by weight of the polyvinyl chloride resin powder shown in Example 1, and 100 parts by weight of the acrylic powder shown in Example 1. 15 parts by weight of system oligomer, ultraviolet curing catalyst (Darcure NO, 1116) 0,4
5 parts by weight, 30 parts by weight of dioctyl phthalate, Example 1
Plastisol was prepared by kneading 10 parts by weight of the secondary plasticizer, 2 parts by weight of PB stabilizer, and 1.5 parts by weight of carbon black in the same manner as in Example 1. The obtained plastisol had a low viscosity of 250 voids.

Next, in the same manner as in Example 1, the above-mentioned brass tisol was applied to a coating thickness of 150 μm, heated at 210°C for 1 minute to gel, and then immediately coated with an engraved roll in the same manner as in Example 1. The surface layer of the paint film was embossed and then irradiated with ultraviolet light (H20 manufactured by Toshiba Denzai,
OOL/6) was performed for 0.5 seconds to produce a vinyl chloride coated steel plate.

The coating film appearance of the obtained vinyl chloride coated steel sheet was good;
The hardness of the coating film was 95 and was a hard film. Further, as a result of evaluating the workability by DuPont impact processing test (1/2 inch φXIKgX50cm), no cracking of the coating film was observed even at -5°C, indicating good workability. Further, as a result of measuring the glossiness of the coating film surface, it was 6, indicating a good matting effect. In addition, as a result of evaluating the embossed state of the surface using the same method as in Example 1, Ra: 3.5 μm, Rmax: 30.5
A good embossed state was observed in μm. Furthermore, the indentation resistance of the obtained vinyl chloride-coated steel sheet was evaluated in the same manner as in Example 1, and as a result, no abnormalities in embossing were observed, indicating good indentation resistance. Furthermore, the bleed resistance of the obtained vinyl chloride coated steel sheet was evaluated in the same manner as in Example 1, and as a result, no liquid substances such as plasticizers were observed on the surface of the polyester film, indicating excellent bleed resistance.

On the other hand, in the method of the present invention described above, when UV irradiation is performed immediately after applying plastisol or gelling the paint film (before embossing), the embossed state of the paint film surface is evaluated using a surface roughness meter. As a result, Ra: 2.0 μm, 1.9 μm, Rmax: 20.5
μm, 19.0 μm, and the embossing property was poor.

Example 3 100 parts by weight of a mixture in which 25 parts by weight of the polymethyl methacrylate powder shown in Example 1 was blended with 100 parts by weight of the polyvinyl chloride resin powder shown in Example 1, an acrylic monomer manufactured by Shin Nakamura Kaji ■, TMPT) 10 parts by weight, 0.35 parts by weight of the ultraviolet curing catalyst shown in Example 2, 0.05 parts by weight of the organic peroxide shown in Example 1, 30 parts by weight of dioctyl phthalate, the secondary compound shown in Example r9q1 A plastisol was prepared by kneading 10 parts by weight of a plasticizer, 1 part by weight of a PB stabilizer, and 1.5 parts by weight of carbon black in the same manner as in Example 1. The obtained plastisol had a low viscosity of 260 voids.

Next, the plastisol described above was applied to a film thickness of 150 μm using the same method as in Example 1, heated at 210°C for 1 minute to gel, and then immediately embossed using the same method as in Example 2 and irradiated with ultraviolet rays. A vinyl chloride-coated steel plate was prepared by performing the following steps.

The coating film appearance of the obtained vinyl chloride coated steel sheet was good;
As a result of measuring the hardness of the coating film, it was 97, indicating that it was a hard film. Also, DuPont impact treated paper @<1/2 inch φ x IK,
As a result of evaluating the workability by 50 g x 50 cm), no cracks in the coating film were observed even at 5°C, indicating good workability. Further, the gloss level of the coating film surface was 5, indicating a good matting effect. In addition, the embossed state of the coating film surface was shown in Example 1.
As a result of evaluation using the same method as above, Ra; 3.3 μm, Rm
ax: 29.5 μm, indicating a good embossed state. Furthermore, as a result of evaluating the indentation resistance in the same manner as in Example 1, no abnormalities in embossing were observed, indicating good indentation resistance. Furthermore, as a result of evaluating the bleed resistance using the same method as in Example 1, no liquid substances such as plasticizers were observed on the surface of the polyester film in contact with the coating surface, indicating excellent bleed resistance.

Example 4 Based on 100 parts by weight of the polyvinyl chloride resin powder shown in Example 1, 30 parts by weight of polymethyl methacrylate powder, 95% by weight having a particle size of 3 to 20 μm, an average particle size of 8 μm, and an average degree of polymerization of 7000, was added. 100 parts by weight of the blended mixture, 15 parts by weight of acrylic oligomer (manufactured by Toagosei Kagaku ■, Aronix M-400), 0.45 parts by weight of the ultraviolet curing catalyst shown in Example 2, 1 part by weight of 30 dioctyl phthalate, carried out. 10 parts by weight of secondary plasticizer shown in PA1, pb
Plastisol was prepared by kneading 2 parts by weight of the system stabilizer and 1.5 parts by weight of carbon black in the same manner as in Example 1. The obtained plastisol had a low viscosity of 250 voids.Next, the plastisol described above was coated to a film thickness of 150 μm in the same manner as in Example 1.
Immediately after gelling by heating at 210°C for 1 minute, embossing and UV irradiation were performed in the same manner as in Example 2 to produce a vinyl chloride-coated steel plate.

The coating film appearance of the obtained vinyl chloride coated steel sheet was good;
As a result of measuring the hardness of the coating film, it was 95, indicating that it was a hard film. In addition, DuPont impact processing test (1/2 inch φxiKgx5
As a result of evaluating the workability using 0cm), no cracks in the coating film were observed even at -5°C, indicating good workability. Also,
The gloss level of the coating film surface was 7, indicating a good matting effect. In addition, the embossed state of the coating film surface was evaluated using the same method as in Example], and the results were as follows: Ra: 3.6 μm, Rg+ax: 31.
It was 5 μm and had a good embossed state. Furthermore, as a result of evaluating the indentation resistance using the same method as in Example 1, no abnormalities in embossing were observed, indicating good indentation resistance. Furthermore, as a result of evaluating the bleed resistance using the same method as in Example 1, no liquid substances such as plasticizers were observed on the surface of the polyester film in contact with the coating surface, indicating excellent bleed resistance.

Example 5 To 100 parts by weight of the polyvinyl chloride resin powder shown in Example 1, 100 parts by weight of a mixture containing 30 parts by weight of cross-linked polymethyl methacrylate powder having a particle size of 3 to 30 μm and an average particle size of 10 μm was mixed at 95% by weight. 1 part by weight of acrylic oligomer (manufactured by Toagosei Kagaku, Aronix M-400)
5 parts by weight of the ultraviolet curing catalyst shown in Example 2, 0.45 parts by weight of the ultraviolet curing catalyst shown in Example 2, 30 parts by weight of dioctyl phthalate, 10 parts by weight of the secondary plasticizer shown in Example 1, 2 parts by weight of PB stabilizer, and 1 part by weight of carbon black. Plastisol was prepared by kneading .5 parts by weight in the same manner as in Example 1. The obtained plastisol had a low viscosity of 200 voids.

Next, the plastisol described above was applied to a film thickness of 150 μm using the same method as in Example 1, heated at 210°C for 1 minute to gel, and then immediately embossed using the same method as in Example 2 and irradiated with ultraviolet rays. A vinyl chloride-coated steel plate was prepared by performing the following steps.

The coating film appearance of the obtained vinyl chloride coated steel sheet was good;
As a result of measuring the hardness of the coating film, it was 92, indicating that it was a hard film. In addition, DuPont impact processing test (1/2 inch φXIKgX5
As a result of evaluating the workability using 0cm), no cracks in the coating film were observed even at -5°C, indicating good workability. Also,
The gloss level of the coating film surface was 4, indicating a good matting effect. In addition, as a result of evaluating the embossed state of the coating film surface using the same method as in Example 1, Ra: 3.871 m, R11ax: 35
．． It was 6 μm and had a good embossed state. Also,
As a result of evaluating the indentation resistance using the same method as in Example 1,
No embossment abnormalities were observed and good indentation resistance was demonstrated. Furthermore, as a result of evaluating the bleed resistance using the same method as in Example 1, no liquid substances such as plasticizers were observed on the surface of the polyester film in contact with the coating surface, indicating excellent bleed resistance.

Implementation @ 6 Contains vinyl acetate with a two-peak type particle size distribution where 45% by weight has a particle size of 0.5-5 μm with a peak at 1.5 μm and 55% by weight has a particle size of 5-40 μm with a peak at 15 μm 100 parts by weight of a mixture in which 30 parts by weight of the polymethyl methacrylate powder shown in Example 1 was blended with 100 parts by weight of polyvinyl chloride-vinyl acetate copolymer powder having an average polymerization degree of 1300 and an amount of 5% by weight; Example 1: 15 parts by weight of the acrylic oligomer shown in Example 1, 0.45 parts by weight of the ultraviolet curing catalyst shown in Example 2, 45 parts by weight of dioctyl phthalate, 2 parts by weight of the organotin stabilizer and 5 parts by weight of titanium white. Plastisol was prepared by kneading in the same manner as in 1. The resulting plastisol viscosity was 300
It was voidy and had low viscosity.

Next, the plastisol described above was applied to a film thickness of 150 μm using the same method as in Example 1, heated at 210°C for 1 minute to gel, and then immediately embossed using the same method as in Example 2 and irradiated with ultraviolet rays. A vinyl chloride-coated steel plate was prepared by performing the following steps.

The coating film appearance of the obtained vinyl chloride coated steel sheet was good;
The hardness of the coating film was measured and found to be 87. Further, the gloss level of the coating film surface was 10, indicating a good matting effect. In addition, as a result of evaluating the embossed state of the coating film surface using the same method as in implementation rIA1, Ra; 3.6), tm, Rma
x: 32.5 μm, indicating a good embossed state. Furthermore, as a result of evaluating the indentation resistance using the same method as in Example 1, no abnormalities in embossing were observed, indicating good indentation resistance.

Furthermore, as a result of evaluating the bleed resistance by the same method as in Example 1, no liquid substances such as plasticizers were observed on the polyester film surface in contact with the coating surface, indicating excellent bleed resistance.

Comparative Example 1 100 parts by weight of the polyvinyl chloride resin powder shown in Example 1, 30 parts by weight of dioctyl phthalate, 15 parts by weight of the secondary plasticizer shown in Example 1, 2 parts by weight of PB stabilizer, and 1.0 parts by weight of carbon black. Plastisol was prepared by kneading 5 parts by weight in the same manner as in Example 1. The resulting plastisol had a viscosity of 300 voids.

Next, the plastisol described above was coated to a film thickness of 150 μm in the same manner as in Example 1, heated at 210°C for 1 minute to gel, and then embossed in the same manner as in Example 1 to form a vinyl chloride film. A coated steel plate was produced.

The coating film appearance of the obtained vinyl chloride coated steel sheet was good;
The hardness of the coating film was measured and found to be 90. In addition, DuPont impact processing test (1/2 inch φX IKgX50c
As a result of evaluating the workability using m), cracks in the coating film were observed at -5°C. Moreover, the glossiness was 10. In addition, as a result of evaluating the embossed state of the coating film surface using the same method as in Example 1, Ra was 3.5 μm and Rmax was 30.3 μm.
It was m. As a result of evaluating the indentation resistance in the same manner as in Example 1, the embossing was crushed and the indentation resistance was poor. Furthermore, as a result of evaluating the bleed resistance by the same method as in Example 1, liquid substances such as plasticizers were significantly observed on the polyester film surface in contact with the coating surface, and the bleed resistance was poor.

Comparative Example 2 100 parts by weight of the polyvinyl chloride resin powder shown in Example 1, 20 parts by weight of the acrylic oligomer shown in Example 1, 0.60 parts by weight of the ultraviolet curing catalyst shown in Example 2, 35 parts by weight of dioctyl phthalate Parts by weight, 2 parts by weight of PB stabilizer and 1.5 parts by weight of carbon black were kneaded in the same manner as in Example 1 to prepare plastisol. The resulting plastisol had a viscosity of 280 voids.

Next, the plastisol described above was applied to a film thickness of 150 μm using the same method as in Example 1, heated at 210°C for 1 minute to gel, and then immediately embossed using the same method as in Example 2 and irradiated with ultraviolet rays. A vinyl chloride-coated steel plate was prepared by performing the following steps.

The coating film appearance of the obtained vinyl chloride coated steel sheet was good;
The hardness of the coating film was measured and found to be 92. The gloss level of the coating film surface was 12. DuPont impact processing test (l/2
As a result of evaluating the workability using inch φ x 1 kg x 50 cm), cracks in the coating film were observed at 5°C, and the workability was poor. In addition, as a result of measuring and evaluating the embossed state of the coating film surface using the same method as in Example 1, Ra;
m.

Rmax: 30, 0 μm. Furthermore, as a result of evaluating the indentation resistance in the same manner as in Example 1, the embossment was crushed and the indentation resistance was poor.

Furthermore, as a result of evaluating the bleed resistance by the same method as in Example 1, a slight amount of liquid substance such as a plasticizer was observed on the polyester film surface in contact with the coating surface, and the bleed resistance was poor.

On the other hand, in the above-mentioned comparative example, when ultraviolet rays were irradiated immediately after coating the plastisol or gelling the coating (before embossing), the embossed state of the surface was evaluated using a surface roughness meter. Respectively, Ra;
1.8μm, 1.7μm, Rmax; 18.6um, 1
The embossing property was 8.0 μm, and the embossing property was poor.

Comparison PA3 Polyvinyl chloride resin powder 1o shown in Example 1.

Parts by weight, 20 parts by weight of the acrylic thread spool shown in Example 3, 0.6 parts by weight of the organic peroxide shown in Example 1, 3 parts by weight of dioctyl phthalate, 2 parts by weight of PB stabilizer, and carbon. Plastisol was prepared by kneading 1.5 parts by weight of black in the same manner as in Example 1. The resulting plastisol had a viscosity of 260 voids.

Next, the plastisol described above was applied to a film thickness of 150 μm in the same manner as in Example 541, heated at 210°C for 1 minute to gel, and then immediately embossed in the same manner as in Example 1 to form a vinyl chloride film. A coated steel plate was produced.

The coating film appearance of the obtained vinyl chloride coated steel sheet was good;
The hardness of the coating film was measured and found to be 91. The gloss level of the coating film surface was 11. DuPont impact processing test (1l2
As a result of evaluating the workability using inch φXIKgX50cm), cracks in the coating film were observed at 0°C, and the workability was poor. In addition, as a result of measuring and evaluating the embossed state of the coating film surface using the same method as in Example 1, Ra1l,
7 μm.

Rmax: 17.5 μm, and the embossed state was poor. Furthermore, as a result of evaluating the indentation resistance in the same manner as in Example 1, the embossment was crushed and the indentation resistance was poor. Furthermore, as a result of evaluating the bleed resistance by the same method as in Example 1, a slight amount of liquid substance such as a plasticizer was observed on the polyester film surface in contact with the coating surface, and the bleed resistance was poor.

Comparison PP44 Polyvinyl chloride resin powder lo shown in Example 1.

Mixture 1o was prepared by blending 25 parts by weight of the polymethyl methacrylate powder shown in Example 1 with respect to parts by weight.

parts by weight, 30 parts by weight of dioctyl phthalate, 10 parts by weight of the secondary plasticizer shown in Example 1, PB stabilizer double #:
Example 1: g and 1.5 weight ji: parts of carbon black
Plastisol was prepared by kneading in the same manner as above. The resulting plastisol had a viscosity of 290 voids.

Next, the plastisol described above was coated to a film thickness of 150 μm in the same manner as in Example 1, heated at 2210°C for 1 minute to gel, and then immediately embossed in the same manner as in Example 1 to form a vinyl chloride film. A coated steel plate was produced.

The coating film appearance of the obtained vinyl chloride coated steel sheet was good;
The hardness of the coating film was measured and found to be 92. The gloss level of the coating film surface was 6. As a result of evaluating the workability by a DuPont floor impact test (1/2 inch φ x 1 Kg x 50 cm), no cracking of the coating film was observed at -5°C. In addition, as a result of measuring and evaluating the embossed state of the coating film surface using the same method as in Example 1, the results showed that Ra: 2.6 μm, Rma
x: 26.5 μm, and the embossed state was somewhat poor.

In addition, as a result of evaluating the indentation resistance in the same manner as in Example 1, a part of the embossing was crushed, and the indentation resistance was found to be somewhat poor. Furthermore, as a result of evaluating the bleed resistance by the same method as in Example 1, a slight amount of liquid substance such as a plasticizer was observed on the polyester film surface in contact with the coating surface, and the bleed resistance was poor.

Comparative Example 5 100 parts by weight of the polyvinyl chloride-vinyl acetate copolymer powder shown in Example 6, 45 parts by weight of dioctyl phthalate,
Plastisol was prepared by kneading 2 parts by weight of an organotin stabilizer and 5 parts by weight of titanium white in the same manner as in Example 1. The resulting plastisol had a viscosity of 330 voids.

Next, the plastisol described above was applied to a film thickness of 150 μm in the same manner as in Example 1, heated at 210°C for 1 minute to gel, and then immediately embossed in the same manner as in Example 1 to chlorinate the plastisol. A vinyl-coated steel plate was produced.

The coating film appearance of the obtained vinyl chloride coated steel sheet was good;
As a result of measuring the hardness of the coating film, it was 76, indicating that it was soft, and the glossiness of the coating film surface was 13.

Dupont impact processing test (1/2 inch φXIKgX50
As a result of evaluating the workability by cm), no cracking of the coating film was observed at -5°C. Furthermore, the embossed state of the coating film surface was measured and evaluated using the same method as in Example 1, and as a result, Ra: 3.7 μnl.

Rmax: 32, 7 μm. Furthermore, as a result of evaluating the indentation resistance in the same manner as in Example 1, most of the embossed surface was crushed, and the indentation resistance was extremely poor. Furthermore, as a result of evaluating the bleed resistance by the same method as in Example 1, a large amount of liquid substances such as plasticizers were observed on the polyester film surface in contact with the coating surface, and the bleed resistance was poor.

〔Effect of the invention〕

As shown in Examples 1 to 6, by the method of the present invention,
By solving the viscosity limitations of plastisol, we were able to produce a vinyl chloride-coated steel sheet with high hardness, excellent indentation resistance, bleed resistance, workability, and surface matte effect.

[Brief explanation of the drawing]

The drawings are particle size distribution diagrams of vinyl chloride polymer powder measured by the Coulter counter method. Figure 1 shows the two-pixel type vinyl chloride polymer powder obtained by the method of the present invention, and Figure 2 shows the conventional one. This is an example of a single peak type vinyl chloride polymer powder. Figure 1 Figure 2 Particle diameter (μm)

Claims (1)

[Claims] 1.95% by weight or more have a particle size of 0.5 to 40 μm,
and 20 to 60% by weight is less than 0.5 to 5 μm and 1 to 3 μm
has a peak at m, and 35-75% by weight is 5-40μ
With respect to 100 parts by weight of vinyl chloride polymer powder having a two-peak type particle size distribution with a peak at 8 to 15 μm, 95% by weight or more has a particle size of 0.1 to 40 μm and an average degree of polymerization of 500 It is characterized by coating a plastisol containing 5 to 60 parts by weight of acrylic polymer powder of ~30,000 and 5 to 60 parts by weight of a heat-curable monomer or oligomer, and gelling the coating film by heating. A method for producing a vinyl chloride coated steel sheet with high hardness and excellent indentation resistance. 2, 95% by weight or more has a particle size of 0.5 to 40 μm,
and 20 to 60% by weight is less than 0.5 to 5 μm and 1 to 3 μm
has a peak at m, and 35-75% by weight is 5-40μ
With respect to 100 parts by weight of vinyl chloride polymer powder having a two-peak type particle size distribution with a peak at 8 to 15 μm, 95% by weight or more has a particle size of 0.1 to 40 μm and an average degree of polymerization of 500 μm. A plastisol containing 5 to 60 parts by weight of acrylic polymer powder of ~30,000 and 5 to 60 parts by weight of an ultraviolet curable monomer or oligomer is applied, and after the coating film is gelled by heating, it is immediately embossed. A method for manufacturing a vinyl chloride-coated steel sheet with high hardness and excellent indentation resistance, characterized by successively irradiating with ultraviolet rays.