JPH0778319B2 - Method for manufacturing decorative paper by electron beam curing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a decorative paper used for a decorative board used for furniture, interior materials, etc. by electron beam curing to have surface hardness, abrasion resistance, heat resistance, stain resistance, etc. It is intended to provide a method for efficiently and inexpensively manufacturing a product having excellent surface texture and smoothness.

Conventional decorative boards include polyester decorative boards, melamine decorative boards, diallyl phthalate decorative boards, thin paper pre-coated paper-coated decorative boards, vinyl chloride sheet-coated decorative boards, and the like.Titanium paper, pre-coated paper, vinyl chloride film, etc. Sheet is used, but in any of the methods, there is a drawback that not only the complexity of the processing steps or lack of surface resistance, but also the drawback that a large amount of heat energy is consumed by all the steps. Have.

In view of these drawbacks, a pre-coated paper using electron beam curing is prepared for the purpose of energy saving, simplification of working process, production efficiency, and improvement of durability, and it is supplied as a decorative paper for a decorative sheet. Methods are known.

As these methods, a method of simply applying an electron beam curable coating material on a decorative base paper, and JP 57-13306 A, JP 57-137158 A, JP 57-133067 A described in JP As described above, a method of impregnating and curing is known.

The inventors of the present invention have conducted various trial production studies to develop a decorative paper utilizing electron beam curing, and have found that the above-mentioned conventional method has the following drawbacks.

When the curable coating material is simply applied to the above-mentioned decorative base paper or printing paper, there are the following drawbacks.

When the electron beam curing paint is applied and cured on the base paper with good penetrability, almost no paint remains on the surface of the base paper, so a certain amount of paper-to-paper strength is obtained, but the surface feel and resistance are obtained. It is not possible.

When the coated paper, printing paper, etc. that prevent permeation are coated with an electron beam curing paint and cured, the surface feels thick,
Although it is possible to obtain resistance, it is not possible to obtain the required inter-paper strength as a decorative paper for decorative boards. Therefore, in order to obtain a decorative paper that has good performance and a long-lasting feeling, it is necessary to use paper that has been previously subjected to a sealer treatment or an impregnation treatment with a urethane-based resin or a vinyl-based resin to strengthen the space between sheets. Since it is not obtained, not only is it extremely disadvantageous in terms of the process, but also the advantage of using the electron beam is halved in terms of energy saving. Furthermore, even if the sealer treatment is performed with a solvent-soluble resin, paper 10 is used because of the correlation between the viscosity of the solution used for the sealer and the resin solid content and the surface property after the sealer.
Only 0 parts by weight of resin solids and 20 parts by weight of sealer can be processed. Therefore, not only it is difficult to obtain a sufficient strength between sheets, but also a problem of eye deterioration occurs at the time of laminating on a decorative board substrate in a later step. Further, when a vinyl-based thermoplastic sealer is used, it is easy to handle, but not only sufficient inter-paper strength cannot be obtained, but also sufficient performance in solvent resistance and heat resistance is obtained. It is not possible. On the other hand, regarding the use of sealant such as urethane type resin, although the inter-paper strength is insufficient, better results can be obtained than vinyl type, but the problem of life up to the top coat after impregnation or the problem of curling of impregnated paper Etc. Furthermore, when these solvent-soluble resins are used for impregnation treatment, the viscosity is considerably low (200 cps or less) and low impregnation (20 parts by weight or less of resin solid content per 100 parts by weight of paper). Otherwise, foaming will occur during drying, and it will be difficult to obtain a product having good surface properties even if a top coat is applied in the subsequent process. The method of impregnation curing described below has the following drawbacks.

Since the resin layer does not remain on the surface, it is not possible to obtain good performance peculiar to electron beam curable paints, and the surface lacks a feeling of flesh.

The method of impregnating a sufficient amount by using a high-viscosity coating material to remove the defects of, can be easily analogized. However, according to the experiments by the present inventors, in this method, impregnation for strengthening the sheet interval is performed. Not only does it take a long time to lose the merit of electron beam curing, but a coating or impregnation viscosity of at least 5000 cps or more is required, so a product with good surface properties cannot be obtained. Further, when a high-viscosity paint is impregnated, there is a great difficulty in terms of equipment, such as the backing of a resin and the like, in which the method of supporting impregnated paper after impregnation is air support.

The present invention improves the drawbacks of the known methods as described above, and uses an electron beam curing method to provide a decorative sheet having extremely good paper-to-paper strength, good surface performance, and surface durability. It provides a way to create.

The present invention is to impregnate a paper having good permeability or a printing paper with an impregnating agent containing an electron beam-curable mixture having an ethylenic double bond in the molecule as a main component, and then impregnating the impregnating paper surface with the impregnating agent. To apply a coating agent mainly composed of an electron beam-curable mixture having an ethylenic double bond in a molecule of higher viscosity, and then irradiate an electron beam to simultaneously cure the impregnating agent and the coating agent. Consists of.

Explaining in more detail the configuration of the present invention, the paper or printing paper with good permeability provided for the present invention, non-sized paper such as titanium paper, linter paper, kraft paper, high-quality paper,
The base paper such as thin paper or printing paper with a single color or a pattern printed on these base paper is optional, but in consideration of the permeation speed etc., air permeability 500 seconds / 100 cc (Gurley type air permeability meter is used The following are desirable. The basis weight of the paper is arbitrary as long as it satisfies the air permeability, but is limited by the ability of the electron beam curing device used, and generally when using an electron beam irradiation device with an acceleration voltage of 200 kv. When using an electron beam irradiation device having a paper thickness of 0.2 m / m or less and an acceleration voltage of 300 kv, it is difficult to cure unless the paper thickness is 0.3 m / m or less.

As the impregnating agent for impregnating the raw paper or the printing paper, those having a known composition having an ethylene double bond in the molecule which is cured by an electron beam can be used. For example, a prepolymer having an ethylenic double bond in the molecule can be used. Polymers or oligomers such as unsaturated polyesters, polyester acrylates, epoxy acrylates, urethane acrylates, polyether acrylates, polyol acrylates, and various acrylates such as melamine acrylates,
Various methacrylates such as polyester methacrylate, epoxy methacrylate, urethane methacrylate, polyether methacrylate, polyol methacrylate and melamine methacrylate, monomers having an ethylenic double bond, for example, styrene-based monomers such as styrene and α-methylstyrene, acrylic acid Methyl, 2-ethylhexyl acrylate, methoxyethyl acrylate, butoxyethyl acrylate, butyl acrylate, methoxybutyl acrylate, methacrylates, methyl methacrylate, ethyl methacrylate, propyl methacrylate, methoxyethyl methacrylate, methacrylic acid Methacrylic acid esters such as ethoxyethyl, phenyl methacrylate, lauryl methacrylate, acrylamide, methacrylamide Unsaturated carboxylic acid amide, 2- (N, N-dimethylamino) ethyl acrylate, 2- (N, N-dimethylamino) ethyl methacrylate, 2- (N, N-dibenzylamino) ethyl acrylate, Substituted amino alcohol esters of unsaturated acids such as (N, N-dimethylamino) methyl methacrylate, 2- (N, N-dimethylamino) propyl acrylate, ethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol Diacrylate, 1,6
-One or a mixture of two or more polyfunctional compounds such as hexanediol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, dipropylene glycol diacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, diethylene glycol dimethacrylate, Or a compound having the ethylenic double bond,
Polythiol compounds having two or more thiol groups in the molecule, such as trimethylolpropane trithioglycolate, trimethylolpropane trithiopropinate,
A mixture of pentaerythritol tetrathioglycolate and the like can be used.

These impregnating agents may optionally contain a small amount of solvent for viscosity adjustment or a small amount of cellulose resin, styrene resin, acrylic resin, vinyl resin, etc. for hardness adjustment. . The impregnating agent can be impregnated by dipping the paper in the impregnating agent and squeezing with a roller,
Although coating using a roll coater, a flow coater, a gravure coater or the like is optional, it is desirable to perform dipping or coating at a viscosity of 100 cps or less in order to uniformly and efficiently impregnate the paper material. The amount of impregnation is 20 to 100 when the amount of base paper used is 100 parts by weight.
It is desirable to impregnate parts by weight of the impregnant. If the amount is 20 parts by weight or less, not only the inter-paper strengthening is not sufficient, but also the coating agent penetrates in the subsequent coating step and it becomes difficult to obtain sufficient surface performance.

If the amount is 100 parts by weight or less, the surface of the impregnating liquid will be excessively applied, which will adversely affect the adhesion of the surface coating agent in a later step. Remarkably poor workability.
Of course, the cost will be higher than necessary. Next, as the coating agent to be applied to the surface of the impregnated paper, if the main component is an electron beam-curable mixture having an ethylenic double bond in the same molecule as that used as the above-mentioned impregnating agent. It is optional. However, it is necessary to use the present coating agent having a higher viscosity than the impregnating liquid. Depending on the viscosity of the impregnating liquid used, the viscosity of the coating agent should be 2 from 200 centipoise.
000 centipoise is preferable. The reason for using a coating agent with a viscosity higher than that of the impregnating agent is that if a coating material with a lower viscosity is used, it should be further impregnated into the base paper, or it should be mixed with the impregnating agent to provide sufficient surface and meat retention. This is because not only it becomes difficult to obtain, but also the original surface performance of the coating agent cannot be obtained. The coating method of the coating agent has a correlation with the viscosity of the coating agent, but may be gravure coating, knife coating, flow coating, roll coating or the like. If the coating agent has a very high viscosity and it is difficult to obtain smoothness on the surface, a release film is wrapped around the coating agent and irradiated with an electron beam to remove the film after curing. A so-called closed system is also possible.
Naturally, this coating agent is mixed with a pigment for coloring, an extender pigment for gloss adjustment, an inorganic filler, a leveling agent for imparting leveling property, a slip agent for imparting slip property, etc. Doing is optional.

As the irradiation of electron beam to cure the resin after impregnation and coating,
Any device can be used as long as it can irradiate a dose sufficient to cure the impregnating agent and the coating agent.

This is not possible with a conventional solvent-soluble sealer. It is possible to create decorative sheets with perfect paper-to-paper strength and good surface properties.

Since it is possible to impregnate a large amount of resin into the space between the sheets compared to the one using a conventional solvent-soluble sealer, it is possible to produce a decorative sheet with very little eye floss when laminated on a substrate in a post process. Possible.

It is possible to create decorative sheets with a feeling of flesh that is not possible with conventional methods.

Since it is possible to perform impregnation coating online with one expensive electron beam irradiation device, it is possible to manufacture decorative paper extremely efficiently.

Since the impregnating agent and the coating agent are separate, you can select the electron beam curing coating material that suits each application, so you can manufacture decorative paper according to various required qualities such as flexibility, surface performance, and cost.

It is possible to create decorative paper with high speed of energy saving, which is a common advantage of electron beam curing.

Examples of the present invention will be shown below.

This embodiment shows one mode of the invention, and the invention is not limited to this embodiment without departing from the spirit of the invention.

The grain printing titanium paper of Example 1 basis weight 80 g / m ^2, the impregnation agent is adjusted to a viscosity 50cps consisting prescribed -1 coated amount applied impregnated with a roll coater so that 50 g / m ^2.

Formulation-1 Aronix 6100 (acrylic oligomer) 100 parts by weight (trade name, Toagosei Kagaku Kogyo Co., Ltd.) Hydroxypropyl acrylate 20 〃 Neopentyl glycol acrylate 20 〃 140 〃 After that, prescribe with a wire bar on the impregnated paper-2 The coating agent whose viscosity is adjusted to 500 cps is coated so that the coating amount becomes 20 g / m ² .

Prescription-2 Aronix 8030 (acrylic oligomer) 100 parts by weight (Brand name Toagosei Kagaku Kogyo Co., Ltd.) Aronix 6100 (acrylic oligomer) 100 parts by weight Hydroxyethyl acrylate 30 〃 230 〃 After that, the coating surface is applied. From this, an electron beam accelerated at 175 kv was irradiated with 5 Mrad in a nitrogen atmosphere having an oxygen concentration of 300 ppm or less to obtain a decorative paper of the present invention.

Example 2 A thin paper having a basis weight of 23 g / m ² is coated and impregnated with a gravure coater so that the coating amount becomes 10 g / m ² with an impregnating agent having a viscosity of 30 cps according to Formulation-3.

Prescription-3 100 parts by weight of Aronix 6100 (acrylic oligomer) (trade name, Toagosei Kagaku Kogyo Co., Ltd.) Trimethylolpropane triacrylate 30 〃 Hydroxypropyl acrylate 20 〃 Methyl ethyl ketone 20 〃 170 〃 Totally reverse roll on the impregnated paper A coating agent having a viscosity of 1500 cps of Formula-4 is coated with a coater so that the coating amount is 10 g / m ² .

Prescription-4 100 parts by weight of Aronix 8030 (acrylic oligomer) (Brand name: Toagosei Kagaku Kogyo Co., Ltd.) Trimethylolpropane triacrylate 150 〃 Ethylene glycol methacrylic acid 50 〃 Titanium oxide 50 〃 Total 350 〃 After that, the coating agent The coated surface was irradiated with 5 Mrad of an electron beam accelerated at 175 kv in a nitrogen atmosphere having an oxygen concentration of 300 ppm or less to obtain a precoated monochromatic decorative paper of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page Judgment panel Judge Chairman Kazuo Sangata Judge Yukie Sato Judge Kazuo Hirata (56) References JP 57-133067 (JP, A) JP 57-39298 (JP, A) )

Claims (1)

[Claims] 1. A paper having good permeability with an air permeability of 500 sec / 100 cc or less, or 100 parts by weight of printing paper mainly containing an electron beam curable mixture having an ethylene double bond in the molecule and having a viscosity of 100 cps or less. 20 to 100 parts by weight of an impregnating agent as a component is impregnated, and the impregnated paper surface is coated with a coating agent having a viscosity of 200 to 2000 cps and an electron beam curable mixture having an ethylene double bond in the molecule as a main component. A method for producing a decorative paper by electron beam curing, in which the impregnating agent and the coating agent are simultaneously cured by irradiating with an electron beam.