JPH0117426B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a matte coating film using an energy beam-curable matte composition. Specifically, the present invention relates to a method of applying an energy ray-curable matte composition such as ultraviolet rays or electron beams to an object to be coated, and forming a matte composition by irradiation with energy rays after a heating process. .

BACKGROUND ART Energy ray-curable compositions such as ultraviolet rays or electron beams have attracted attention from the viewpoint of energy saving, resource saving, space saving, and pollution control, and research and development in the fields of inks, paints, and varnishes have been actively carried out. Along with this, demands for performance have also increased, and in the paint field, there is a demand for a method for forming energy ray-curable matte coatings that has coating properties and film performance equivalent to or better than conventional solvent-based coatings. However, a satisfactory method has not yet been established.

Conventional solvent-based matte paints or varnish matting methods generally use matting agents such as fine silicic acid powder or calcium carbonate, alumina white, clay,
A method has been adopted in which fine inorganic powders such as aluminum stearate or fine organic powders such as polycarbonate, polyethylene, polypropylene, polyacrylonitrile, etc. are mixed into paints. If this technique is directly applied to energy beam curable compositions, a satisfactory matting effect cannot be achieved. Energy beam curable coating compositions aim to save energy, save resources, and be non-polluting, and are generally being developed as solvent-free or high-solids types. Since the composition itself is solvent-free or high-solids, the effect of the added matting agent is not sufficiently exerted, making it difficult to obtain a satisfactory matte coating. Furthermore, when a large amount of matting agent is added, the viscosity of the paint becomes extremely high, making coating difficult and at the same time causing a decrease in the physical properties of the paint film. A matting composition obtained by blending a matting agent such as white carbon or Aerosil into an energy beam curable composition has an extremely high viscosity, which not only makes it difficult to apply, but also makes it impossible to obtain a satisfactory matte surface. Furthermore, if a large amount of organic solvent is used in the energy beam curable matte composition as in conventional solvent-based paints, the original purpose of the energy beam curable composition will be lost.

The present invention was completed as a result of intensive research to establish a method for forming an energy beam-curable matte coating that combines a good finished coating and a matte state that could not be achieved with conventional energy beam-curable compositions. It is something.

An object of the present invention is to provide a solvent-free or high-solids energy ray-curable matte composition that can be cured and dried in an extremely short time by energy ray irradiation, thereby saving resources, energy, and improving the working environment. . Furthermore, the object of the present invention is to provide a matte coating surface with excellent wear resistance, chemical resistance, weather resistance, adhesion, etc. by applying an energy beam curable matte composition to the coated object. Our goal is to provide coating products.

Another object of the present invention is to provide a method for forming a matte coating film having excellent wear resistance, chemical resistance, weather resistance, adhesion, etc. by applying an energy beam curable matte composition to an object to be coated. It is about providing.

That is, the method for forming a matte coating film of the present invention includes the first
As the process, an energy ray curable matte composition consisting of 45 to 99.5% energy ray curable resin containing an energy ray sensitive sensitizer (the same below weight basis), 0.5 to 35% matting agent, and 0 to 20% solvent. As the second step, the matting agent in the energy ray-curable matting composition applied to the coating material floats or arranges on the upper layer or surface of the coating film, causing a matting effect. 30 to 150% of the composition applied so as to obtain a detoxifying effect.
A process of heating at a temperature of ℃ for 0.5 seconds to 60 seconds,
The third step is the step of irradiating the matte composition on the coated material with energy rays and curing it. The first to third steps are carried out continuously using, for example, a belt conveyor. It is done.

Each of the three steps of the present invention is an important step, and if even one of them is missing or the order is changed, it will be impossible to achieve the object of the present invention.

Since the method for forming a matte coating film using the energy ray-curable matte composition of the present invention can be cured by extremely short energy ray irradiation, it can be used not only on plastics, which are unsuitable for long-term high-temperature treatment, but also on metals, paper, etc. glass,
It can be applied to various materials such as wood, and can be applied as a low-viscosity solvent-free or high-solids type, so it can eliminate the negative effects of solvents and greatly improve the working environment, creating a matte surface with good productivity. We can provide coating products with First, in the first step, the coating step, the energy ray curable matte composition used in the present invention is made by blending an energy ray curable resin containing an energy ray sensitive sensitizer, a matting agent, a solvent, etc. This is a general term for the resulting matte paints, varnishes, and inks. Energy ray-curable resins include conventionally known resin compositions that are polymerized or crosslinked to form a coating film by irradiation with energy rays, such as epoxy ring resins. Epoxy resin compositions that are polymerized by cationic ring-opening polymerization, and cationically polymerizable compositions such as cyclic ethers, lactones, and vinyl compounds (e.g., those described in Japanese Patent Publication No. 17040/1983, and other catalysts) Several types of photosensitive onium salts are known, but all of them generate Lewis acids when irradiated with energy rays such as ultraviolet rays. Examples include resin compositions, urethane resin compositions, acrylic urethane resin compositions, modified compositions thereof, and polyethylene thiol resin compositions.

Moreover, the energy ray sensitizer contained in the energy ray curable resin refers to a substance that induces polymerization of the energy ray curable resin upon irradiation with energy rays.

The energy beam-curable matte composition of the present invention can contain various additives as long as the effects of the present invention are not impaired. The matting agents that can be used in the energy beam curable matting composition of the present invention include conventionally known fine silicic acid powder or calcium carbonate;
Inorganic fine powders such as alumina white, clay, silica, aluminum stearate, magnesium silicate, magnesium carbonate, white carbon, etc. or polycarbonate, polyethylene,
Examples include organic fine powders such as polypropylene, polyacetal, polyacrylonitrile, etc. Among them, the average particle size is 1 to 20μ, the oil absorption rate is 200% or less, and the matte composition has a relatively low viscosity increase. Disinfectants are particularly preferred.

Depending on the amount of the matting agent added, it is possible to create energy beam-curable matting compositions that are 3-minute matte, semi-matte, and completely matte, and generally 0.5 to 35% is added to the matte coating composition.
%, preferably about 5 to 20%, can achieve the desired matte surface. Furthermore, when various organic solvents as viscosity modifiers are blended into the matte composition and used as a high solids energy ray-curable matte composition, it is possible to add up to 20% of the solvent. The organic solvent is appropriately selected depending on the energy ray curable resin used, but usually toluene, xylene, benzene, ethyl acetate, butyl acetate, cyclohexanone, methyl ethyl ketone,
Examples include methyl isobutyl ketone, acetone, dimethylformamide, methanol, ethanol, ethylene chloride, and trichloroethylene, which are used alone or in mixtures.

The energy ray-curable matte composition can be applied to the object by a conventional method such as a roll coater, a gravure coater, a gravure offset, a spray, a squeeze, a brush coat, or the like. The thickness of the coating film may be the same as that of conventional solvent-based matte coatings, and it is preferable to have a film thickness of 1 to 15 μm, for example.

Next is the second step, the warming and heating step.
In the present invention, in this step, most of the matting agent particles in the matting composition applied to the object to be coated come out to the upper layer or surface of the coating film before the coating film hardens, creating a uniform uneven state on the coating film surface. It is formed so that a matte effect can be obtained. As a heating method, for example, infrared rays can be used to achieve a thermal effect in a short time, but if the object to be coated does not like long-term high-temperature heating, heating methods such as hot air can be used. preferable. Moreover, even more effective heating can be expected by using infrared rays and hot air in combination. Heating conditions for the applied composition vary depending on the heating method and the type of the object to be coated, but heating is required at a temperature of 30°C to 150°C for about 0.5 seconds to 60 seconds, and the composition is solvent-free. 50 for things
It is preferable to heat and hold the composition for 1 to 30 seconds at a temperature of 100°C to 100°C, and for 0.5 to 20 seconds at a temperature of 40 to 80°C for high solids compositions. In addition, in the first coating step,
The second step can also be accelerated by heating the energy ray curable matte composition or the object to be coated in advance during coating.

Next is the third step, an energy ray irradiation step, in which the matte composition applied to the coating material is dried and cured in this step to obtain the desired matte coating film. In the present invention, ultraviolet rays, electron beams, and other radiation can be used as the energy rays necessary to cure the energy ray curable composition.

As one example of a preferred embodiment of the present invention, an energy beam curable matting composition is applied to an object to be coated such as paper, metal, plastic, etc., and the applied object is placed on a belt conveyor and continuously heated. A matte coating film is formed through a heating process followed by an ultraviolet irradiation process. The line speed is determined by the heating conditions in the second and third steps, the output and type of energy rays, etc., but energy ray curable compositions can be cured with short irradiation, so high-speed, large-scale processing is not possible. Optimal.

The effect of the present invention is that it provides a novel method for forming energy ray-curable matte coatings that causes less solvent pollution and can process various coated objects at high speed. A further object of the present invention is to provide a method for forming matte coatings on materials unsuitable for long-term high-temperature treatment, such as paper and plastics. Furthermore, the matte coating film obtained by the method of the present invention can be subjected to various post-processing, such as surface finishing by embossing, printing, etc.

Hereinafter, typical examples of the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples. In the example, "part" means part by weight, and the degree of gloss of the coating film was measured using a gloss meter (TG-P manufactured by Tokyo Denshoku Co., Ltd.).
The 60° specular reflectance was measured.

Example 1 A vinyl chloride decorative sheet with a wood grain pattern printed on an energy ray curable matting composition obtained by blending 7 parts of a silica matting agent with 93 parts of an epoxy resin composition containing an energy ray sensitive sensitizer. Immediately heat the surface with hot air to maintain the surface temperature at 60°C for 3 seconds, then heat it using a high-pressure mercury lamp (80W/cm, 4KW) with a lamp height of 10cm and a line speed of 15m. A matte coating film was formed by irradiating with ultraviolet light at /min. The matte coating film obtained in this way has excellent adhesion and abrasion resistance.
The reflectance measured by a gloss meter at an incident angle of 60°C was 10%.

Example 2 In the same manner as in Example 1, an energy ray-curable matting composition obtained by blending 80 parts of a photosensitive epoxy resin composition, 10 parts of a matting agent, and 10 parts of ethyl acetate was applied to a PVC leather sheet. Apply it to a film thickness of 5μ,
Immediately heat the surface with hot air to maintain it at 50℃ for 3 seconds, then heat it with a high-pressure mercury lamp (80W/cm,
4KW) lamp height 10cm, line speed
By performing ultraviolet irradiation at 20 m/min, a matte coating film with excellent wear resistance and adhesion was obtained.

Example 3 In the same manner as in Example 1, an energy ray-curable matting composition obtained by blending 89 parts of a photosensitive epoxy resin composition, 10 parts of a matting agent, and 1 part of an anti-settling agent was applied to a polyethylene sheet for cosmetic containers. A polyethylene sheet having a matte coating film with excellent scratch resistance, surface hardness resistance, adhesion, etc. was obtained by applying it to the surface and irradiating it with ultraviolet rays after a heating process. Reflectance measurement using a gloss meter showed 15%.

Example 4 80 parts of photosensitive acrylic resin composition, 10 parts of matting agent
An energy beam matting composition obtained by blending 10 parts of methyl ethyl ketone as a solvent was uniformly applied to a printing board paper to a film thickness of 5 μm. Next, the composition was heated with a far-infrared heater so that the temperature of the composition on the coated surface could be maintained at 60℃ for 2 seconds, and then heated with a high-pressure mercury lamp (80W/cm, 4KW) to a lamp height of 7cm.
When UV irradiation was performed at a line speed of 15 m/min, a matte coating film with excellent wear resistance and surface hardness was obtained.

Example 5 An energy ray-curable matting composition obtained by blending 90 parts of a photosensitive epoxy resin composition and 10 parts of a matting agent was applied to aluminum foil to a film thickness of 5μ, and then
By heating with warm air at 80° C. for 3 seconds and immediately irradiating with ultraviolet rays, an aluminum foil having a matte surface with a reflectance of 30% measured by a gloss meter was obtained.

Example 6 The same energy ray curable matte composition as in Example 5 was applied to a printed aluminum test piece to a film thickness of 7μ, and the coated surface was heated with a far-infrared heater.
It was heated at 500W and the surface temperature was maintained at 80°C for 4 seconds. Next, UV irradiation was performed using a high-pressure mercury lamp (80W/cm, 4KW) at a lamp height of 10cm and a line speed of 15m/min to improve adhesion, abrasion resistance, and
A matte coating film with excellent properties was obtained.

Example 7 Energy beam curable gloss obtained by blending 50 parts of acrylated epoxy resin, 50 parts of pentaerythritol acrylate, 10 parts of silica matting agent, 2 parts of additives and 2 parts of sensitizer benzoin ether When the same method as in Example 1 was carried out using the antiseptic composition, a matte coating film with a reflectance of 15% was obtained.

Comparative Example 1 In Example 1, when the energy ray-curable matte composition was applied to a vinyl chloride decorative sheet and cured by direct UV irradiation without heat treatment, the reflectance of the matte coating was 60. It was %.

Claims (1)

[Claims] 1. As a first step, energy ray curing consisting of 45 to 99.5% of an energy ray curable resin containing an energy ray sensitive sensitizer, 0.5 to 35% by weight of a matting agent, and 0 to 20% by weight of a solvent. As a second step, the matting agent in the energy ray-curable matting composition applied to the coating material floats to the upper layer or surface of the coating film. and a step of heating the composition at a temperature of 30° C. to 150° C. for 0.5 seconds to 60 seconds to obtain a matting effect. A method for forming a matte coating film of an energy ray-curable matte composition, which requires the following three steps: curing by irradiating energy rays.