JP2556315B2 - Method for producing scratch-resistant matte material - Google Patents

Description

The present invention relates to a scratch-resistant matting material. The scratch-resistant matting material of the present invention is suitable for various applications such as a CRT antiglare filter, a membrane switch, various displays, nameplates, surface materials for electronic devices such as calculators, when a plastic is used as a base material.

[Conventional technology]

Conventionally, in order to carry out matting, a method of forming fine irregularities on the substrate itself by embossing, a method of coating and baking a silicone baking type paint containing a matting agent, an ionizing radiation curing containing a matting agent There is a method of applying a mold paint and irradiating with ionizing radiation.

[Problems to be solved by the invention]

However, in the above method, the scratch resistance of the surface obtained is insufficient, and in the method of 1, the scratch resistance is worse than that in the method because it contains a matting agent, and the baking time is long and the baking temperature is high. Therefore, it is not suitable for plastic films with a low softening point, and although the method requires a short curing time, the poor scratch resistance of the surface due to the inclusion of the matting agent is essentially eliminated. In addition, due to the energy distribution of ionizing radiation during curing, the blending of solvent in the paint, etc., the matting agent moves to the part where curing has been delayed and the gloss varies, and even after curing, the matting agent moves There is instability such as changes over time.

In this invention, it has sufficient scratch resistance and eliminates the drawbacks of containing a matting agent, and the energy distribution of ionizing radiation, variation in gloss due to solvent blending in the paint, and the edge after curing with time It is an attempt to eliminate the change.

[Means for solving problems]

In this invention, without using a matting agent, a material that can be dried in a tentative state after being applied as an ionizing radiation-curable resin is used, and fine unevenness is obtained by an embossing method in the same manner as in a thermoplastic resin sheet. By providing and irradiating with ionizing radiation after providing, it is possible to eliminate the above-mentioned drawbacks of the conventional technique.

That is, the present invention is, "on the surface of the substrate, an uncured layer made of an ionizing radiation curable resin that is solid at room temperature in the uncured state, is non-adhesive, and is thermoplastic, Then, the layer is heated and pressed with an embossing plate to form fine irregularities that produce a matt effect, and then the layer is cured by irradiation with ionizing radiation. The method of manufacturing a matte material is the gist.

[Action]

In this invention, while using the ionizing radiation curable resin, since no matting agent is used, the performance of the cured film of the ionizing radiation curable resin is sufficiently exerted, and a surface having high scratch resistance is obtained, Since no matting agent is used, all the defects caused by the matting agent are eliminated, and the gloss distribution due to the energy distribution of ionizing radiation and the solvent blending in the paint, and the change over time in the gloss after curing do not occur. .

〔Example〕

 Examples of the present invention will be described below.

Substrate The substrate of the scratch-resistant matte material of the present invention varies depending on the use of the scratch-resistant matte material, and examples thereof include a polyethylene film which is a plastic film, a polypyrropylene film, a polyvinyl chloride film, Vinylidene chloride film, polyvinyl alcohol film, polyethylene terephthalate film, polycarbonate film,
Nylon film, polystyrene film, ethylene-
Vinyl acetate copolymer film, ethylene-vinyl alcohol copolymer film, ionomer, etc. can be used,
Of these, polyethylene terephthalate film, polycarbonate film and polyvinyl chloride film are preferable.

In addition, as the base material, depending on the application, thin paper, bleached kraft paper, titanium paper, linter paper, paperboard, paper such as gypsum board paper, wood base such as wood, plywood, particle board, gypsum board, gypsum slag, etc. Gypsum base material such as board,
Also used are transition cement boards such as pulp cement boards, asbestos cement boards and wood chip cement boards, metal foils or sheets such as GRC and concrete, iron, aluminum and copper.

The above materials may be appropriately combined and used, or, even if the combination is not performed in advance, a method in which another base material is attached to the back surface after processing is performed using the first base material Good.

Ionizing radiation-curable resin layer This layer is solid at room temperature in the uncured state, and has thermoplasticity and solvent solubility, but it is apparent by coating and drying, or when touched by hand. Is formed of an ultraviolet curable resin or an electron beam curable resin which gives a coating film which is non-fluid and non-adhesive. Further, in particular, in the present invention, the ionizing radiation-curable resin layer does not contain a matting agent. As such a resin, there are the following two thermoplastic resins having a radically polymerizable unsaturated group.

(1) Those having a radically polymerizable unsaturated group in a polymer having a glass transition temperature of 0 to 250 ° C. More specifically, a compound obtained by polymerizing or copolymerizing the following compounds (1) to (4) with a radically polymerizable unsaturated group introduced by the methods (a) to (d) described below can be used.

A monomer having a hydroxyl group; N-methylol (meth) acrylamide, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2
-Hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate and the like.

Monomers having a carboxyl group: (meth) acrylic acid, (meth) acryloyloxyethyl monosuccinate and the like.

Monomer having epoxy group: glycidyl (meth) acrylate and the like.

Monomers having an aziridinyl group: 2-aziridinylethyl (meth) acrylate, allyl 2-aziridinylpropionate and the like.

Monomer having an amino group: (meth) acrylamide,
Diaceon (meth) acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate and the like.

Monomers having sulfone groups: 2- (meth) acrylamido-2-methylpropanesulfonic acid, etc.

Monomer having an isocyanate group: 1,4-toluene diisocyanate and 2-hydroxyethyl (meth) acrylate, such as an adduct of 1 mole to 1 mole of diisocyanate and a radical polymerizable monomer having active hydrogen.

Further, adjusting the glass transition point of the above copolymer,
In order to adjust the physical properties of the cured film, the above compound and the following monomers copolymerizable with this compound can be copolymerized. Examples of such a copolymerizable monomer include, for example, methyl (meth) acrylate,
Ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate,
Examples thereof include isoamyl (meth) acrylate, cyclohexyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate.

Next, the polymer obtained as described above is reacted by the methods (a) to (d) described below to introduce a radical-aggregating unsaturated group to obtain an ultraviolet or electron beam curable resin. .

In the case of (a) a polymer or copolymer of a monomer having a hydroxyl group, a monomer having a carboxyl group such as (meth) acrylic acid is subjected to a condensation reaction.

(B) In the case of a polymer or copolymer of a monomer having a carboxyl group or a sulfane group, the above-mentioned monomer having a hydroxyl group is subjected to a condensation reaction.

(C) In the case of a polymer or copolymer of a monomer having an epoxy group, an isocyanate group or an aziridinyl group, the above-mentioned monomer having a hydroxyl group or a monomer having a carboxyl group is added.

(D) In the case of a polymer or copolymer of a monomer having a hydroxyl group or a carboxyl group, a monomer having an epoxy group, a monomer having an aziridinyl group, or a diisocyanate compound and a hydroxyl group-containing acrylate monomer One to one mole of the adduct of the product is subjected to an addition reaction.

In order to carry out the above reaction, it is desirable to add a trace amount of a polymerization inhibitor such as hydroquinone and to carry out the reaction while sending dry air.

(2) A compound having a melting point of room temperature (20 ° C) to 250 ° C and having a radically polymerizable unsaturated group. Specific examples thereof include stearyl acrylate, stearyl (meth) acrylate, triacryl isocyanurate, cyclohexanediol diacrylate, cyclohexadiol di (meth) acrylate, spiroglycol diacrylate, and spiroglycol (meth) acrylate. Also,
In the present invention, the above (1) and (2) may be used as a mixture, and a radical polymerizable unsaturated monomer may be added to them. This radically polymerizable unsaturated monomer improves the crosslink density upon irradiation with ionizing radiation and improves heat resistance. In addition to the above-mentioned monomers, ethylene glycol di (meth) acrylate,
Polyethylene glycol di (meth) acrylate, hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, Dipentaerythritol hexa (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, polyethylene glycol diglycidyl ether di (meth) acrylate, propylene glycol diglycidyl ether di (meth) acrylate, polypropylene glycol diglycidyl ether di (meth ) Acrylate, sorbitol tetraglycidyl ether tetra (meth) acrylate, etc. can be used. Solids of the copolymer mixture described above
It is preferably used in an amount of 0.1 to 100 parts by weight, relative to 100 parts by weight.Although the above can be sufficiently cured by an electron beam, when cured by ultraviolet irradiation, benzoquinone as a sensitizer, Benzoin ethers such as benzoin and benzoyl methyl ether, halogenated acetophenones, and biacetyls that generate radicals by ultraviolet irradiation can also be used.

The ionizing radiation curable resin as described above is, if necessary, diluted with a solvent or a monomer so as to have a viscosity through application, applied by a suitable coating method on a substrate, and after application, by embossing, Form fine irregularities.

The embossing can be performed by a known method. For example, as an embossing plate, an embossing roll made of an etching method, a mill extrusion method, an electroforming method, or the like is used, or the embossing roll is heated, or in the same manner. The high-frequency embossing method can be used with the manufactured embossing plate, but other methods may also be used.
The gloss of the embossed surface can be changed by changing the pitch and depth of the unevenness of the plate surface of the embossing plate.

Although ordinary ionizing radiation curable resin is sticky even if it is in a liquid state in the uncured state or is apparently solid, it cannot be embossed like this, but in the present invention, it is similar to the ordinary thermoplastic resin. It uses a special ionizing radiation curable resin that dries after being applied and then undergoes a drying process.Therefore, not only embossing, but also handling of the substrate after applying the ionizing radiation curable resin. No problem occurs on the top.

After the embossing, the base material provided with the ionizing radiation curable resin layer is irradiated with ionizing radiation to cure the ionizing radiation curable resin layer.

Typical examples of ionizing radiation are ultraviolet rays or electron beams.As electron beams, various electrons such as Cocklost-Walton type, Bandegraph type, resonant transformer type, insulating core transformer type, linear type, dynamitron type high frequency type, etc. Using an electron beam emitted from a linear accelerator with an energy in the range of 50 to 1000 KeV, preferably 100 to 300 KeV, and also as a light source for ultra-high pressure mercury lamp, high pressure mercury lamp, low pressure mercury lamp, carbon arc, xenon arc, metal halide lamp, etc. What is emitted from an ultraviolet ray source is used.

In the above, the explanation has been given mainly on the assumption that a layer is formed on one side of the base material and embossed, but if necessary, a layer may be formed on both surfaces and embossed. The same or different.

〔The invention's effect〕

According to this invention, it is possible to form a matte surface by embossing without using a matting agent, and the matte surface itself is made of a cured film of an ionizing radiation curable resin, which is high. Scratch resistance can be imparted, and since no matting agent is used, uneven gloss and change in luster of the product over time do not occur.

 Specific examples according to the present invention will be described below.

[Example 1] A polyethylene terephthalate film (Lumirror T-60 manufactured by Toray Industries, Inc.) having a thickness of 100 µm was used as a substrate,
After coating a melamine acrylate UV curable resin (Mitsubishi Yuka Fine Co., Ltd., Upia LZ-075) on one side with methyl ethyl ketone diluted to a solid content of 40% using a roll coater, Dry with hot air (100 ° C) to turn the coating into a solid film, thickness 10
A μm ultraviolet curable resin layer was formed to obtain a coated film.

Next, after preheating the coated film with a preheater, an embossing roll with unevenness of 5 μm height produced by etching method was heated at 90 ° C while pressing between the heat roll and the rubber impression cylinder at 5 m / min. The resin layer side was passed through at the speed of 4 to perform embossing to obtain an embossed film.

Further, the embossed film is passed through a UV irradiation device equipped with 5 high pressure mercury lamps with ozone (output 80w / cm) at a speed of 5m / min to irradiate UV rays, and the embossed film is embossed. Thus, a film obtained by three-dimensionally crosslinking the ultraviolet curable resin layer of 3 was obtained.

The film thus obtained has a scratch-resistant matte surface, the matte surface of which is treated with steel wool # 00.
The 00 was attached to a Gakushin-type abrasion tester, and even if it was rubbed 20 times back and forth under a load of 500 g, it was not damaged.

In addition, the gloss of the obtained matte surface (based on JIS-Z-8471) was 35.6 ± 0.5 on a 10-point average, showing almost no unevenness.

Furthermore, the gloss of 35.6 immediately after production is 1 week and 1
The gloss after leaving for 3 months was 35.3 and 35.5, respectively, and it was confirmed that there was almost no change with time.

Claims (2)

(57) [Claims] 1. An uncured layer made of an ionizing radiation-curable resin which is solid at room temperature in the uncured state, is non-adhesive, and is thermoplastic, is provided on the surface of a substrate, and then, By heating the layer and pressing with an embossing plate,
Form fine irregularities that produce a matte effect on that layer, then
A method for producing a scratch-resistant matting material, which comprises irradiating with ionizing radiation to cure the layer. 2. A layer made of an ionizing radiation curable resin which is solid at room temperature in the uncured state and is thermoplastic and does not contain a matting agent. For producing a scratch-resistant matte material.