JP2007196423A - Method for producing decorative sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a decorative sheet which prevents the blocking of a winding core part and other parts when the sheet is transported or stored while a transparent resin layer is rolled up, can obtain adhesion equivalent to that obtained by adhesion facilitating treatment when the sheet is coated with a surface treating agent without being subjected to the adhesion facilitating treatment such as corona treatment, and suppresses the occurrence of a hurt or partial peeling in a finishing layer after the application of the surface treating agent. <P>SOLUTION: The method for producing the decorative sheet 10 having at least a substrate layer 4, a printing layer 2, a transparent polyolefin resin layer 1, and a finishing layer 5 arranged in turn from below includes the first process for pretreating the back of the transparent resin layer 1, the second process for forming the printing layer 2 on the pretreated surface obtained in the first process, the third process for laminating the transparent resin later 1 and the substrate layer 4 together with the printing layer 2 obtained in the second process made an underside, the fourth process in which immediately after the surface treating agent is applied on the surface of the transparent resin layer 1, the surface treating agent is dried initially at 120-180°C, and the fifth process for forming the finishing layer 5 by heating the surface treating agent at 180-240°C. The substrate layer 4 can have a foamable synthetic resin layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a decorative sheet having a polyolefin-based transparent resin layer on the surface, and in particular, a pretreatment (easy adhesion treatment) step for the transparent resin layer when a surface treatment agent is applied to the polyolefin-based transparent resin layer. The present invention relates to a method for producing a decorative sheet that can be omitted and that uniform application of the surface treatment agent can be easily achieved, and that the defect of the polyolefin-based transparent resin layer can be reduced and storage stability can be maintained.

The transparent resin layer of decorative sheets used for flooring and wallpaper materials has good transparency that allows the lower printing layer to be visible, adhesion to the printing layer, and scratch resistance for the purpose of protecting the entire sheet on the surface side. -Adhesion with a surface treatment layer that requires wear resistance is required.
Conventionally, films or sheets made of polyvinyl chloride resin have been used. However, there are problems with plasticizer bleed blended with polyvinyl chloride resin and environmental measures during incineration. Resins (for example, olefin resins, acrylic resins, urethane resins, etc.) are being used, and olefin resins such as ethylene-vinyl acetate copolymers (EVA) and ethylene-acrylic copolymers. The thing using the film or sheet | seat which consists of is mainly used.

However, in order to perform surface treatment or printing on such a transparent resin layer made of olefin resin, the surface is roughened by corona treatment, plasma treatment, etc. from the nonpolarity (micropolarity) of olefin resin, or surface oxidation. It is necessary to carry out a pretreatment (easy adhesion treatment) for improving the adhesion and wettability with a surface treatment agent or ink such as increasing surface activity. Since the method by surface oxidation involves a decrease in physical properties of the transparent resin layer, corona treatment is usually performed as an easy adhesion treatment.
Even if a paint or ink can be applied to the surface of an olefin resin that is not subjected to such an easy adhesion treatment (hereinafter also referred to as “untreated surface”), it peels off from the olefin resin film after drying. In many cases, it became a problem in terms of adhesion.

Therefore, in the production of the conventional decorative sheet, such an easy adhesion treatment process (corresponding to the following A process and C process) to the olefin resin film is essential.
Step A for pretreating the surface of the transparent resin layer,
Step B, in which a surface treatment agent is applied to the surface pretreated in Step A and dried.
C process for pretreating the back surface of the transparent resin layer,
D step of providing a printing layer on the surface pretreated in C step;
After passing through the four steps, after applying the surface treatment agent on one side (front side) of the transparent resin layer and printing on the opposite side (back side),
E process of bonding the transparent resin layer subjected to the surface treatment and printing and the base material layer,
It is common to go through at least 5 steps.
The easy adhesion treatment (pretreatment) to the transparent resin layer performed in the A process and the C process in the above processes is usually performed in an independent process, not in a continuous process of the A to E processes. Is called. That is, as a previous step, an easy adhesion treatment is performed on both surfaces of the transparent resin layer, the transparent resin layer is wound up in a roll shape, and then put into the decorative sheet production process.
The transparent resin layer that has been treated with easy adhesion on both sides, even immediately after being processed, when the roll is formed, the portion close to the winding core is blocked and cannot be used for the production of decorative sheets and is disposed of. It was.
Further, as time elapses after the easy adhesion treatment is performed, a portion that cannot be used due to blocking increases, resulting in a problem that the yield of the transparent resin layer decreases.
Furthermore, since the surface treatment layer is provided on the transparent resin layer (Step B), the surface treatment layer is scratched or partially peeled off at the time of the bonding process in order to perform bonding with the base material (Step E). There were also problems that occurred.

  Since the present invention only requires easy adhesion treatment such as corona treatment on only one side of the transparent resin layer, even if the transparent resin layer is rolled and transported or stored, the core portion and other portions are blocked. In addition, even if the surface treatment agent is applied without performing easy adhesion treatment such as corona treatment, it is possible to obtain adhesiveness equivalent to that when performing easy adhesion treatment, It is an object of the present invention to provide a method for producing a decorative sheet in which scratches and partial peeling are unlikely to occur in the surface treatment layer after application.

In order to solve the above problems, the present inventors first noticed that blocking of the transparent resin layer occurs in order to perform easy adhesion treatment on both surfaces of the transparent resin layer.
Therefore, when a method for eliminating at least one easy adhesion treatment was studied, a specific temperature condition was immediately applied after applying a surface treatment agent on the untreated surface of the transparent resin layer made of an olefin resin layer. The knowledge that it was possible to obtain close contact with the surface treatment agent equivalent to that when pretreatment such as corona treatment was performed by performing the treatment below.

  Next, under such knowledge, in the conventional method, after the surface treatment agent and printing are performed on both surfaces of the transparent resin layer, bonding with the base material layer is performed through the obtained printed layer. Focusing on this point, by performing the surface treatment process after bonding the transparent resin layer and the base material layer, scratches and partial peeling are likely to occur in the applied surface treatment agent every time the processing process is performed. It was found that the problem can be solved.

This invention is made | formed based on the said knowledge, The decorative sheet of this invention is a manufacturing method of the decorative sheet which has a base material layer, a printing layer, a polyolefin-type transparent resin layer, and a surface treatment layer in order from the bottom. The first step of pretreating the back surface of the transparent resin layer, the second step of providing a print layer on the pretreated surface obtained in the first step, and the transparent resin layer with the print layer obtained in the second step as the bottom surface The third step of laminating the base material layer, the fourth step of initial drying of the coating agent at 120 to 180 ° C. immediately after coating the surface treatment agent on the surface of the transparent resin layer, and the coating agent at 180 to 240 ° C. And a fifth step of forming a surface treating agent layer by heating at
Furthermore, when the base material layer has a foamable synthetic resin layer, the foamable synthetic resin layer can be formed by foaming the foamable synthetic resin layer in the fifth step.
The heating time in the fifth step is preferably 120 to 200 seconds in consideration of drying of the surface treatment agent and foaming of the foamable synthetic resin layer.

The 1st process of the manufacturing method of the decorative sheet which concerns on this invention is a process of pre-processing (easy-adhesion process) of the back surface of a polyolefin-type transparent resin layer.
This transparent resin layer is provided on the surface side of the decorative sheet, has a predetermined transparency with which the lower printed layer can be visually recognized, and for example, a film of an olefin resin is used.
The olefin-based resin is not particularly limited, and for example, an ethylene-vinyl acetate copolymer (vinyl acetate monomer part content ratio 5 to 30%), an ethylene-acrylic copolymer (acrylic monomer part content ratio 5). ˜50%), polyolefins, polyolefin ionomers and the like can be preferably used.
In addition, acrylic acid (AA), methacrylic acid (MAA), methyl methacrylate (MMA), ethyl acrylate (EA), methyl methacrylate (MA), etc. can be used as the acrylic monomer of the ethylene-acrylic copolymer. These monomers may be used alone or in combination of two or more as appropriate.

  This mixed use mode may be used by uniformly mixing the resins, or when using a plurality of transparent resin layers as described later, different olefinic resins are used for each layer. There are various modes of use.

The transparent resin layer may be a single layer or a plurality of layers as described above.
In the case of a plurality of layers, the olefin resin of each layer may be the same or different.
In the case of different types, for example, three layers of an ethylene-vinyl acetate copolymer, an ethylene-methacrylic acid copolymer, and a polyolefin ionomer can be used.
In the case of a plurality of layers, the surface treatment agent is applied to the uppermost layer, and the pretreatment is performed on the lowermost layer to provide a printing layer.

  Moreover, you may add suitably the additive generally used for this kind of transparent resin layers, such as a stabilizer, an antistatic agent, a lubricant, and an antibacterial agent, in a transparent resin layer.

  The method for pretreating the back surface of such a transparent resin layer (easy adhesion treatment) is not particularly limited as long as adhesion and wettability with the ink constituting the printing layer to be described later are enhanced. For example, corona treatment, plasma There are methods such as physical treatment for roughening the surface by treatment and chemical treatment for increasing surface activity by surface oxidation.

The 2nd process in the manufacturing method of the decorative sheet concerning the present invention is a process of providing a printing layer in the field where the pretreatment obtained at the 1st process was performed.
If this printing layer is visually recognized through the transparent resin layer, for example, pattern printing (pattern printing), solid coating printing, character printing, etc. are formed by a normal printing technique such as screen printing, gravure printing, offset printing, etc. Good.

The 3rd process in the manufacturing method of the decorative sheet which concerns on this invention is a process of laminating | stacking a transparent resin layer and a base material layer by making the printing layer obtained at the 2nd process into a lower surface (in other words, via a printing layer). It is.
As a method of laminating, a method of bonding a normal transparent resin layer and a base material layer can be used. For example, after applying a primer to one or both of the printed layer surface and the base material layer of the transparent resin layer on which the printed layer is formed, or after performing primer treatment, the base material layer and the transparent resin layer Can be laminated and integrated by, for example, bonding by thermal lamination.

As this base material layer, what is conventionally used as a base material layer of a decorative sheet may be used, and it is composed of at least a synthetic resin layer and a base fabric layer, and the synthetic resin layer has a foam layer. The resin used may be an olefin resin. The synthetic resin layer may be composed of a plurality of layers. Further, a reinforcing layer such as glass fiber may be provided on the synthetic resin layer.
As the base fabric layer, a woven fabric, a knitted fabric, a non-woven fabric, or the like can be used.

The 4th process in the manufacturing method of the decorative sheet which concerns on this invention is a process of pre-drying at 120-180 degreeC immediately after apply | coating a surface treating agent to the surface of the transparent resin layer laminated | stacked with the base material layer at the 3rd process. It is.
Subsequently, the fifth step is a step of completely curing the surface treatment agent at 180 to 240 ° C. to form a surface treatment layer.
Immediately after the surface treatment agent is applied, the heating process is performed in two stages of low temperature and high temperature in order to keep the surface treatment agent on the transparent resin layer in the low temperature pre-drying first. The surface treatment layer is integrated (formed) by partially evaporating the solvent consisting of water and organic solvent in the agent and then completely removing the solvent by the next high-temperature heating, and uniform adhesion with the transparent resin layer ( This is to obtain (fixation).
When the temperature is lower than 120 ° C. in the low-temperature heating for pre-drying, the surface treatment agent cannot be uniformly fixed on the transparent resin layer, and there may be a portion where the surface treatment agent is not adhered, and the adhesion strength May decrease. On the other hand, if the temperature exceeds 180 ° C., the surface treatment agent cannot be uniformly formed on the transparent resin layer, and there is a possibility that cracking or the like may occur during film formation.
If the high temperature of the fifth step is less than 180 ° C., it takes time to completely cure, and there is a possibility that the adhesion strength may be reduced. If the temperature exceeds 240 ° C., the base material layer may be deformed or adhered. There is a risk that the strength may be reduced or the surface treatment layer may be discolored.
The heating method is not particularly limited as long as the above temperature condition is obtained. For example, two heating ovens or the like may be provided in the production line to set the respective heating temperatures, or one heating oven is used. In such a case, it may be possible to change the temperature partially.

  In this way, immediately after applying the surface treatment agent, the transparent resin layer and the surface can be heated without applying an easy adhesion treatment such as corona treatment before applying the surface treatment agent by heating under the above two-stage temperature conditions. Strong adhesion to the treatment agent can be obtained.

  As described above, the decorative sheet manufacturing method of the present invention consisting of a total of 5 steps can omit the pretreatment step when applying the surface treatment agent to the transparent resin layer, and the production process is shortened compared to the conventional method. It becomes possible to improve the yield of the resin layer and improve the storage stability.

In the present invention, as the above-mentioned surface treatment agent, a commonly used surface treatment agent can be used. For example, a simple substance such as polyurethane, polyvinyl acetate, acrylic resin, two or more kinds of copolymers, Mixtures of seeds or more can be used.
If these surface treatment agents, not only have sufficient flexibility to protect the decorative sheet, it is possible to obtain high adhesion to the untreated surface of the transparent resin layer made of an olefin resin, The object of the present invention can be effectively achieved.

Furthermore, in the present invention, the heating time in the initial drying in the fourth step is preferably 60 to 120 seconds.
If the heating time is less than 60 seconds, the preliminary drying is insufficient, and if it exceeds 120 seconds, the production efficiency is lowered and the adhesion may be lowered.
The heating time in the fifth step is preferably 120 to 200 seconds.
When the heating time is less than 120 seconds, the adhesiveness is lowered without being completely cured, and when it exceeds 200 seconds, the production efficiency is lowered and the base material layer may be deformed or discolored.

When the foamable synthetic resin layer is provided on the base material layer, it is preferable to select a foaming agent or foaming aid that foams at a heating temperature of 180 to 240 ° C. and a heating time of 100 to 180 seconds.
Examples of the foaming agent used to form the foamable synthetic resin layer include thermal expansion foaming agents such as microcapsules, azodicarbonamide (ADCA), dinitroso / pentamethylene / tetramine (DPI), and oxybisbenzene / sulfonyl. Any pyrolytic foaming agent such as hydrazide (OBSH) can be used. Since the blending amount of the foaming agent varies depending on the desired foaming ratio and type of foaming agent, it cannot be determined unconditionally, but the foaming agent is about 1 to 5 parts by weight with respect to 100 parts by weight of the resin component. Is preferred.

Various methods can be employed to provide the foamable synthetic resin layer. For example, the following method may be performed.
Using calendar molding, etc., the raw material of the foamable synthetic resin layer described later is kneaded, sheeted, and topped to form a foamable synthetic resin layer in an unfoamed state, and other layers are laminated and integrated with the foamable synthetic resin layer. A base material layer is formed.

Although the resin component which comprises the synthetic resin layer of a base material layer and / or a foamable synthetic resin layer is not specifically limited, It is preferable that it is an olefin resin, Especially, an ethylene-vinyl acetate copolymer, an ethylene-acrylic type | system | group It is more preferable to use a resin such as a copolymer, polyethylene, or modified polypropylene alone or in combination of two or more.
As the acrylic monomer of the ethylene-acrylic copolymer, acrylic acid (AA), methacrylic acid (MAA), methyl methacrylate (MMA), ethyl acrylate (EA), methyl methacrylate (MA), etc. can be used. These monomers may be used alone or in combination of two or more kinds as appropriate.

  In addition, in the synthetic resin layer and / or foaming synthetic resin layer, stabilizers, antistatic agents, fillers such as calcium carbonate and talc, flame retardants such as aluminum hydroxide and magnesium hydroxide, lubricants, antibacterial agents, etc. The additive generally used for this kind of synthetic resin layer may be added in a necessary amount.

Furthermore, in the manufacturing method of the decorative sheet of this invention, embossing can also be given from the transparent resin layer side.
This embossing is preferably performed while the entire decorative sheet immediately after foaming is in a heated state in order to satisfactorily form uneven patterns by embossing.
The embossing may be such that the uneven pattern is formed only on the transparent resin layer, or the uneven pattern may be formed across the print layer and the base material layer.

According to the method for producing a decorative sheet of the present invention, the transparent resin layer and the surface treatment layer equivalent to the decorative sheet produced by the conventional production method can be omitted, although the easy adhesion treatment step when applying the surface treatment agent can be omitted. In addition, the provided surface treatment layer can be obtained as a uniform layer, and scratches and partial peeling are less likely to occur in the surface treatment layer after application than in the conventional production method.
In addition, since it is only necessary to perform easy adhesion treatment only on one side of the transparent resin layer, even if the transparent resin layer is easily adhered in a separate process and wound into a roll and moved or stored, it can block on the core portion, etc. It is possible to use the transparent resin layer without waste, and it is possible to store and store the transparent resin layer that has been subjected to the easy adhesion treatment in a roll shape, so that the production efficiency is high. Are better.

In FIG. 1, the embodiment example of the decorative sheet 10 obtained by the manufacturing method of this invention is typically shown.
In FIG. 1, 1 is a transparent resin layer made of an olefin resin, 2 is a printed layer applied to the back surface of the transparent resin layer 1, 4 is a base material layer, and 5 is a surface treatment layer.

Examples 1 to 4 (decorative sheet according to the production method of the present invention)
<First Step> The back surface of a 0.1 mm thick transparent resin layer 1 made of an ethylene-vinyl acetate copolymer (vinyl acetate monomer portion 15%) was roughened by corona discharge treatment.
<Second Step> Gravure printing 2 was performed on the roughened surface.
<Third Step> A solvent-type epoxy resin adhesive was applied to the entire surface of the obtained printing layer 2 and a base material layer 4 having a thickness of 2.0 mm was bonded thereto.
<Fourth Step> After the surface treatment agent shown in Table 1 is applied to the surface of the transparent resin layer 1 after the third step and immediately preliminarily dried under the temperature conditions shown in Table 1,
<5th process> It heated on the temperature conditions shown in Table 1, the surface treatment layer 5 was formed, and the decorative sheet 10 was obtained.

  The surface treating agent used in this example is a solvent type polyurethane resin paint.

Comparative example 1 (decorative sheet by a conventional manufacturing method)
<Step A> Both surfaces of a 0.1 mm thick transparent resin layer made of an ethylene-vinyl acetate copolymer (vinyl acetate monomer portion 15%) were roughened by corona discharge treatment.
<Step B> The same surface treating agent as in Example 1 was applied on the roughened surface and then dried after gravure application.
<Step C> Gravure printing was performed on the roughened surface on the back surface to which the surface treatment agent was applied.
<Step D> A solvent-type epoxy resin adhesive was applied to the entire surface of the obtained printed layer, and a base material layer having a thickness of 2.0 mm was bonded to obtain a decorative sheet.

Comparative Examples 2-4
<First Step> to <Third Step> were performed in the same manner as in Example 1 above.
<Fourth Step> After the surface treatment agent shown in Table 1 is applied to the surface of the transparent resin layer 1 after the third step and immediately preliminarily dried under the temperature conditions shown in Table 1,
<5th process> It heated on the temperature conditions shown in Table 1, the surface treatment layer 5 was formed, and the decorative sheet 10 was obtained.

  The surface states of the decorative sheets obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were observed, and a tape peeling test and a surface friction peeling test were performed as follows. The results are also shown in Table 1.

[Observation of surface condition]
The surface of the obtained decorative sheet was visually observed to confirm the presence or absence of partial peeling and scratches.
○: Partial peeling / scratches and cracks are not observed. Δ: Partial peeling, scratches and cracks are observed on the surface of the decorative sheet itself.

[Tape peeling test]
A cellophane tape (registered trademark) having a width of 25 mm and a length of 50 mm was attached to the surface of the obtained decorative sheet, this was peeled off, and the presence or absence of peeling of the surface treatment agent (paint) was confirmed and evaluated in the following manner.
◎: No peeling is observed and the film is completely adhered ○: The paint peeled off on the tape is slightly observed and cannot be said to be completely adhered x: Almost all the paint is separated from the decorative sheet, and on the cello tape Attached to

[Surface friction peeling test]
The surface of the decorative sheet thus obtained was rubbed with a roll wrapped with rubber on the assumption that it was rubbed against the guide roll, and the presence or absence of peeling of the surface treatment agent (paint) was confirmed and evaluated in the following manner.
○: No peeling at all Δ: The paint peeled off on the roll is slightly observed, but can be used as a decorative sheet ×: Partial peeling is clearly observed on the surface of the decorative sheet itself

  Furthermore, the transparent resin layer which performed the corona discharge process on the one side created in the Example, and the transparent resin layer which performed the corona discharge process on the both surfaces used in Comparative Example 1 were each rolled into a roll by winding 30 m around the core. Three rolls were prepared, and the unrolled state of the roll was observed after 1 hour, 5 hours, and 24 hours at room temperature of 25 ° C. The product with corona discharge treatment on one side could be unwound to the core part without problems, but the product with corona discharge treatment on both sides was used after 1 hour after the core part was blocked. I couldn't solve it in a state where I could The unusable amount increased for 5 hours and 24 hours, and it was felt as if it was peeled off when unwound.

As can be seen from Table 1, according to the method for producing a decorative sheet of the present invention, it is possible to achieve complete adhesion equivalent to the decorative sheet produced by the conventional production method without performing easy adhesion treatment, and after application as compared with the conventional method. It can be understood that partial peeling and scratches are unlikely to occur in the surface treatment agent.
Further, from the observation of the unrolled state of the roll, it can be seen that the yield of the transparent resin layer and the mobile storage property are improved.

The method for producing a decorative sheet of the present invention has effects such as an easy adhesion treatment step when applying the surface treatment agent and a subsequent drying time, as compared with the conventional method.
The decorative sheet obtained by such a manufacturing method is easy to clean, easy to construct, easy to replace, etc., as a sheet laid on the floor or wall, etc., as a general house, office building, store building, It can be widely used in commercial facilities, public facilities, temples, and various other buildings.

It is a figure which shows typically the example of embodiment of the decorative sheet obtained by the manufacturing method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Decorative sheet 1 Polyolefin-based transparent resin layer 2 Print layer 4 Base material layer 5 Surface treatment layer

Claims (3)

A method for producing a decorative sheet having at least a base layer, a printing layer, a polyolefin-based transparent resin layer, and a surface treatment layer in order from the bottom,
A first step of pretreating the back surface of the transparent resin layer;
A second step of providing a printed layer on the pretreated surface obtained in the first step;
A third step of laminating the transparent resin layer and the base material layer with the printed layer obtained in the second step as the bottom surface;
A fourth step of initial drying the treatment agent at 120 to 180 ° C. immediately after applying the surface treatment agent to the surface of the transparent resin layer;
Furthermore, the 5th process of heating the said processing agent at 180-240 degreeC, and forming a surface treatment layer,
A method for producing a decorative sheet, comprising: The base material layer has a foamable synthetic resin layer,
The method for producing a decorative sheet according to claim 1, wherein the foamable synthetic resin layer is formed by foaming the foamable synthetic resin layer in the fifth step. The method for producing a decorative sheet according to claim 1 or 2, wherein the heating in the fifth step is performed for 120 to 200 seconds.

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