JP2003276138A - Decorative sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a decorative sheet which shows a sufficient lamination strength not only at the normal temperature but also at a high temperature of 90°C or higher and outstanding weatherability and suitability for environments in addition to proper pliability, resistance to wear, mar resistance and chemical resistance and after-processability, using a material other than a vinyl chloride resin. <P>SOLUTION: This decorative sheet is constituted by providing an anchor coat layer comprising a two-pack curable anchor coating agent on the surface of a base material sheet made of a non-vinyl chloride material, and further providing a polypropylene resin layer on the anchor coat layer by coextrusion through an adhesive resin layer made of a random polypropylene resin modified by an unsaturated carboxylic acid or its anhydride. In this decorative sheet, the principal agent component of the two-pack curable anchor coating agent is constituted of an isocyanate curable resin comprising a mixture of a polyester polyol and a urethane-modified polyester polyol. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to wooden boards,
The present invention relates to a decorative sheet that is used as a makeup plate by bonding it to the surface of an inorganic board, a metal plate or the like with an adhesive.

[0002]

2. Description of the Related Art Conventionally, vinyl chloride resin sheets have been the most popular as decorative sheets used for the above-mentioned makeup plates. However, in recent years, vinyl chloride resin has become a factor in the generation of hydrogen chloride, which causes acid rain when incinerated, and dioxin, which is a highly toxic substance, and also the problem of bleed-out of the plasticizer added to the vinyl chloride resin sheet. Yes, it has become a problem from the viewpoint of environmental protection.
Due to such circumstances, a decorative sheet using a resin instead of a vinyl chloride resin has been demanded.

Therefore, a decorative sheet using a resin and a copolymer such as polyethylene, polypropylene, polyethylene terephthalate, ethylene-vinyl alcohol and acrylic as a resin replacing the vinyl chloride resin has been proposed.

Among them, a makeup using a polypropylene resin which has appropriate flexibility, abrasion resistance, scratch resistance, heat resistance, chemical resistance, post-processability and the like required for a decorative sheet and is supplied at a low cost Many seats have been proposed. Some decorative sheets using this polypropylene resin have a single layer, but since the design is also important, most of them are composed of a laminate of two or more layers.

Since the polypropylene resin is a resin having poor adhesion to the same or different resins, when the polypropylene resin layer is melt-extruded and laminated on another resin layer (base sheet), for example, Generally, extrusion lamination is performed through an adhesive resin layer such as a maleic acid-modified polyethylene resin or an ethylene- (meth) acrylic acid copolymer.

However, in recent years, not only a decorative sheet using a non-vinyl chloride type material (non-halogen type material) other than a vinyl chloride resin but also a demand for further improvement in physical properties has been great. One of them is the further improvement of heat resistance. When the surface temperature or the ambient temperature of the existing decorative sheet exceeds 90 ° C., the laminate strength is significantly reduced.

The main cause of the decrease in the laminate strength at high temperature is that the maleic acid-modified polyethylene resin, ethylene- (meth) acrylic acid copolymer, etc. used in the above-mentioned adhesive resin layer, at a temperature of 90 ° C. or higher. It is considered that the internal cohesive force is reduced due to thermal softening.

Therefore, the present inventors have already studied and proposed to employ a maleic acid-modified polypropylene resin having high heat resistance as a resin constituting the adhesive resin layer in order to secure the laminate strength at high temperature. (Japanese Patent Application 2000
-108641). However, this resin is generally
Even if the temperature is higher than ℃, the internal cohesive force does not decrease much compared to room temperature, but it has higher rigidity and lower flexibility and interfacial adhesion than maleic acid-modified polyethylene resin. Interface peeling tends to occur. Therefore, there is a concern that the laminate strength may decrease due to exposure to the environment such as repeated cold heat and ultraviolet irradiation.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems. The problem is to use a material other than vinyl chloride resin and In addition to flexibility, abrasion resistance, scratch resistance, chemical resistance, and post-processability, it has sufficient laminate strength not only at room temperature but also at high temperatures of 90 ° C or higher, and has excellent weather resistance and environmental suitability. To provide.

[0010]

In order to achieve the above object, the invention according to claim 1 is an anchor coat comprising a two-component curing type anchor coating agent on the surface of a base sheet made of a non-vinyl chloride material. In a decorative sheet comprising a layer, and a polypropylene resin layer at least provided by coextrusion on the layer further through an adhesive resin layer made of a random polypropylene resin modified with an unsaturated carboxylic acid or an anhydride thereof, The decorative sheet is characterized in that the main component of the two-component curable anchor coating agent is an isocyanate curable resin composed of a mixture of polyester polyol and urethane-modified polyester polyol.

Next, the invention according to claim 2 is the decorative sheet according to claim 1, wherein the mixture of the polyester polyol and the urethane-modified polyester polyol is 20 to 80% by weight of polyester polyol and 80% of urethane-modified polyester polyol. It is characterized in that it is constituted by a mixing ratio of ˜20% by weight.

Further, in the invention according to claim 3, in the decorative sheet according to claim 1 or 2, the isocyanate component contained in the two-component curing type anchor coating agent is
It is characterized in that the mixing ratio of isophorone diisocyanate is 30 to 98% by weight and the other isocyanate component is 2 to 70% by weight.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing an example of a decorative sheet according to the present invention. In this decorative sheet, basically, an anchor coat layer 3 made of a two-component curing type anchor coat agent is provided on the surface of a base material sheet 1 made of a non-vinyl chloride material, and an unsaturated carboxylic acid is further formed on the anchor coat layer 3. Alternatively, at least the polypropylene resin layer 5 is provided by coextrusion through the adhesive resin layer 4 made of the random polypropylene resin modified with the anhydride. In the figure, 2 is a pattern layer such as a wood grain pattern provided on the base material sheet 1, 5a is a concave pattern provided on the surface of the prepropylene resin layer 5, and 6 is the outermost surface of the prepropylene resin layer 5. The top coat layers provided in the above are respectively shown.

The base sheet 1 is made of synthetic resin material such as polyethylene, polypropylene, polyethylene terephthalate, ethylene-vinyl alcohol and the like and copolymers thereof. As a method for manufacturing the base sheet 1, for example, a T-die extrusion method can be mentioned. In this case, the synthetic resin material for forming the base sheet 1 is directly colored with a concealing colorant such as a dye or a pigment and extruded from a T die in a heat-melted state to form the base sheet 1. By doing so, the base sheet 1 can be made to have a concealing effect.

As a method for coloring the base sheet 1 in the T-die extrusion method, a fine powdery colorant obtained by treating a pigment with a dispersion aid or a surfactant is used to form the base sheet 1. Of the uncolored ordinary synthetic resin material directly mixed and used, or the uncolored ordinary synthetic resin material for forming the base sheet 1 and the high-concentration pigment are melted. Master batch pellets that have been kneaded and pre-dispersed are created in advance, and in the extrusion hopper,
There is also a masterbatch method of dry blending the masterbatch pellets and an ordinary uncolored synthetic resin material for forming the substrate sheet 1, but the invention is not particularly limited thereto.

The types of pigments mentioned above may be those usually used, but in consideration of heat resistance and weather resistance,
Inorganic pigments such as titanium oxide, ultramarine blue, cadmium pigment, iron oxide and the like are preferable. Organic pigments such as phthalocyanine pigments,
A quinacridone pigment or the like can be used. The selection of the mixing ratio and color of the pigment with respect to the synthetic resin material is based on this base sheet 1.
It may be appropriately determined in consideration of the degree of concealment required for the product or the design, and these selections are not limited at all.

On the other hand, as a method of applying the pattern layer 2 to the base sheet 1, there are a method of applying the surface layer of the base sheet and a method of applying the base sheet itself (within the layer of the sheet 1). A printing method or a transfer method can be used as a method for applying the surface. In the case of the printing method, a general printing method such as a gravure printing method can be adopted, and the ink used at that time is also known, that is, a coloring agent such as a dye or a pigment or an extender pigment is added to the vehicle, and Plasticizer, stabilizer, wax, grease, desiccant, curing agent, thickener, dispersant,
The ink may be an ink obtained by optionally adding a filler and the like and sufficiently kneading with a solvent, a diluent and the like. In the case of the transfer method, for example, the hiding layer and / or the pattern layer 2 or both are formed on the optional transfer base sheet different from the base sheet 1 for the decorative sheet by the above-mentioned forming method or the like. In addition, the transfer base material sheet is peeled off after being bonded to the base material sheet 1 by a thermal laminating method, a dry laminating method, a wet laminating method, an extrusion laminating method or the like, which will be described in detail later, to thereby form a hiding layer. Alternatively, a method of transferring the pattern layer 2 or both to the base sheet 1 can be used.

Also, when the calendering method is used as the method for producing the base sheet 1 having the concealing property, the same method,
That is, the hiding property and the pattern are imparted to the base sheet 1 by a method of imparting a color hiding property or a pattern to the base sheet 1 itself, or a method in which these methods are combined with the above-mentioned printing method, transfer method and the like. can do.

In the decorative sheet of the present invention, the transparent polypropylene resin layer 5 is laminated on the surface of the base material sheet 1 having such a constitution because the design, the protection of the pattern layer 2 and the scratch resistance. This is to develop abrasion resistance, chemical resistance, weather resistance and the like.

In general, when a polypropylene resin layer is laminated on a base material sheet constituting the decorative sheet of the present invention, as a method therefor, an extrusion laminating method in which a polypropylene resin is melt-extruded from a T-die onto a base material sheet. , A co-extrusion method in which both resins are melt-extruded from a T-die. Of these, the extrusion laminating method has the highest productivity and is preferably used.

However, what is problematic here is the lamination strength of the base material sheet and the polypropylene resin layer. Therefore, in general, in order to obtain a laminating strength, an adhesive resin layer is interposed between them to perform lamination.

However, when a maleic acid-modified polyethylene resin or an adhesive resin such as an ethylene- (meth) acrylic acid copolymer is coextruded and laminated, it is possible to obtain sufficient room temperature laminating strength by the above method. However, it is not possible to obtain the laminate strength under high temperature.

On the other hand, in order to make the laminate strength at room temperature and high temperature compatible in the decorative sheet, the present inventors use unsaturated carboxylic acid or its anhydride as the resin for the adhesive resin layer 4. It has already been found that the problem can be solved by using a modified random polypropylene resin (for example, a random polypropylene resin graft-polymerized with maleic anhydride) (Japanese Patent Application No. 2000-
108641).

That is, in the case of polyethylene modified with unsaturated carboxylic acid or its anhydride, the laminate strength at room temperature is high, but at a high temperature, especially at 90 ° C. or more, it is markedly reduced. The modified homopolypropylene does not show a decrease even at 100 ° C, but the strength itself at room temperature is low. On the other hand, as described above, when the random polypropylene modified with unsaturated carboxylic acid or its anhydride is used as the resin constituting the adhesive resin layer 4, not only the laminate strength at room temperature is relatively good, It is based on the finding that a relatively stable laminate strength can be obtained even at high temperatures within a range of up to about 100 ° C.

Examples of the unsaturated carboxylic acid or its anhydride include acrylic acid, methacrylic acid, maleic acid, phthalic acid, citraconic acid, itaconic acid and their anhydrides. Among these, maleic anhydride is used. Acids are particularly preferred. The amount of these unsaturated carboxylic acid units or their anhydride units is preferably 1 × 10 ⁻⁴ or more and 1 × 10 ⁻¹ mmol equivalent or less as carbonyl groups per 1 g of the composition. The amount of units of unsaturated carboxylic acid or its anhydride contained by modification is 1 × 10.
^-4 mmol equivalent or less does not produce sufficient effect, and 1
Even if it is more than × 10 ^-1 mmol equivalent, the effect of improving the adhesiveness becomes small.

In the present invention, not only is the adhesive resin layer 4 configured as described above, but also the anchor coat layer 3 provided at the interface between the adhesive resin 4 and the base sheet 1
An isocyanate-curable resin that forms a urethane bond by the reaction of a polyol component and an isocyanate component,
Further, an isocyanate-curable resin whose main component is a mixture of polyester polyol and urethane-modified polyester polyol is used. As a result, while maintaining the flexibility of the anchor coat layer 3, it is possible to improve the quick-drying property of the cured coating film and further improve the laminate strength, and the laminate has not only heat resistance but also cold resistance and weather resistance and is produced. It is possible to obtain a decorative sheet with good properties.

That is, in the decorative sheet of the present invention, in order to obtain more sufficient strength, the anchor coat layer 3 is formed on the surface of the base sheet 1 (the surface on which the pattern layer 2 is provided).
Then, the adhesive resin layer 4 and the polypropylene resin layer 5 are provided on the anchor coat layer 3 by co-extrusion.

By the way, when the main component constituting the anchor coat layer is the urethane-modified polyester polyol alone, the flexibility of the anchor coat layer is maintained, but the manifestation of the laminate strength is delayed and the anchor coat layer is not lifted or displaced during the manufacturing process. Can occur.

Further, when the main component constituting the anchor coat layer is a polyester polyol alone, the fast drying property of the cured coating film of the anchor coat layer is maintained and the laminate strength is sufficiently developed, but the flexibility of the anchor coat layer is low. There is a possibility that floating will occur due to the load such as environmental changes.

In the present invention, the mixture ratio of the polyester polyol and the urethane-modified polyester polyol constituting the anchor coat layer 3 is 20 to 80% by weight of the polyester polyol and 80 to 20% by weight of the urethane-modified polyester polyol. And while maintaining the flexibility of the anchor coat layer 3, it is possible to further improve the quick-drying property of the cured coating film and the development of the laminate strength.

On the other hand, when isophorone diisocyanate is mixed as each isocyanate component used in the anchor coat layer 3, the cohesive force and flexibility of the anchor coat layer 3 are appropriately improved, and the ordinary temperature laminating strength, heat resistant laminating strength, and laminating strength after environmental test are improved. The inventors have also found that it is possible to obtain a decorative sheet that is improved and has a high overall strength.

The amount of each isocyanate component is preferably 30 to 98% by weight of isophorone diisocyanate and 2 to 70% by weight of the other isocyanate components in the total amount of isocyanate components. Incidentally, the isocyanate component to be combined is not particularly limited to these, for example, one selected from hexamethylidine isocyanate, xylylene diisocyanate, mesitylene diisocyanate, tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, or the like, or A mixture of two or more of them can be preferably used. In particular, 4,4-diphenylmethane diisocyanate has very high activity and can improve the adhesion to polypropylene even in a small amount, and is therefore preferably used.

The method for forming the anchor coat layer 3 is preferably a gravure method (gravure printing method, gravure coating method), but is not limited to the gravure method.

The decorative sheet of the present invention, as described above,
In order to obtain sufficient laminating strength, the base sheet 1
The anchor coat layer 3 (on which the pattern layer 2 is provided) is applied, and then the adhesive resin layer 4 and the polypropylene resin layer 5 are coextruded on the anchor coat layer 3 to form the adhesive layer 4. At this time, the laminate strength can be further improved by blowing ozone gas onto the extruded resin forming the adhesive resin layer 4.

The ozone treatment device used when the ozone gas is blown to the extruded resin forming the adhesive resin layer 4 may be a general one, and is not particularly limited. There are low-concentration high-flow rate type and high-concentration low-flow rate type as the ozone treatment method, and the ozone treatment method cannot be said unequivocally.
Ozone concentration may be adversely affected, and therefore ozone concentration is preferably 20 to 50 g / Nm ³ and ozone flow rate is 1 to 10 Nm ³ / h.

In some cases, the transparent polypropylene resin layer 5 on the surface of the decorative sheet is used as shown in FIG. 1 in order to obtain a feeling of touch on the surface of the decorative sheet and a further design feeling.
It is also possible to form a concave pattern 5a on the surface of the polypropylene resin layer, fill the filling ink in the concave portion (wiping), and provide the top coat layer 6 on the outermost surface of the polypropylene resin layer 5.

As a method for applying the concave pattern 5a, a usual hot press embossing method may be used, and the method is not limited at all. When the T-die extrusion method is used as the method of forming the polypropylene resin layer 5 (method of obtaining two layers of the adhesive resin layer 4 and the polypropylene resin layer 5 by coextrusion film forming method), the molten resin is cooled. It is a general method that a concave pattern is formed on the surface of the chill roll to be solidified, the extruded resin is embossed between the chill roll and the press roll, and the concave pattern 5a is formed on the surface of the polypropylene resin layer 5. It is also preferable to embed ink in the recesses of the applied recess pattern 5a and provide the top coat layer 6 on the outermost surface of the polypropylene resin layer 5. It can be carried out by the same method as the wiping treatment and the top coat treatment which are performed on the decorative sheet.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The decorative sheet of the present invention will be described below together with its specific manufacturing method with reference to the drawings. <Example 1> As a substrate sheet 1, a random polypropylene resin containing 6% by weight of an inorganic pigment, 0.2% by weight of a phenol-based antioxidant, and 0.1% by weight of a hindered amine-based light stabilizer.
A sheet obtained by melt-extruding a resin containing 3% by weight and 0.2% by weight of an antiblocking agent was used. Next, after corona treatment is applied to the surface of the base material sheet 1, a pattern ink (Toyo Ink Mfg. Co., Ltd.) is applied by a gravure printing method.
Made by Lamister) and given a wood grain pattern, pattern layer 2
And Further, a two-component curing type urethane anchor coating agent [Toyo Ink Mfg. Co., Ltd .; EL510 (polyester polyol) 5
A mixture of 0% by weight and 50% by weight of A520 (urethane modified polyester polyol) manufactured by Mitsui Takeda Chemical Co., Ltd. is used. Also, as the isocyanate, a mixture of 5% by weight of 4,4-diphenylmethane diisocyanate, 50% by weight of isophorone diisocyanate and 45% by weight of hexamethylene diisocyanate is used. A curable urethane anchor coating agent was used. ] Was applied by a gravure printing method to form an anchor coat layer 3.

Separately from this, 0.2% by weight of phenolic antioxidant, 0.3% by weight of hindered amine type light stabilizer, 0.5% by weight of benzotriazole type UV absorber and blocking agent were added to homopolypropylene resin. A transparent polypropylene resin layer 5 constituting resin containing 0.2% by weight of an inhibitor, and a modified random polypropylene resin constituting an adhesive resin layer 4 constituting by graft polymerization with maleic anhydride (carbonyl group in 1 g of modified random polypropylene). (A content of 0.02 millimole equivalent) is co-extruded from a T-die, and is integrated with the base sheet 1 and is passed between a cooling roll and a pressure roll, which are embossed with a conduit, to obtain a laminate. And embossing are performed at the same time, and the adhesive resin is applied to the surface of the anchor coat layer 3 on the base material sheet 1 on which the pattern layer 2 is applied. 4 via a polypropylene resin layer 5 which is embossed concave pattern 5a on the surface was laminated. Immediately before the lamination with the base material sheet 1, ozone gas was blown to the coextruded random polypropylene resin surface serving as the adhesive resin layer 4 by an ozone treatment device to further improve the lamination strength. The obtained laminate was well laminated without causing interfacial peeling due to expansion and contraction of the sheet.

Concave pattern 5 of this laminated laminate
A top coat layer 6 was applied to the outermost surface of the transparent polypropylene resin layer 5 provided with a using a urethane top coat agent to obtain a decorative sheet of the present invention having a structure as shown in FIG.

<Example 2> As a main component of the anchor coating agent used in the anchor coating layer 3, a mixture of 10% by weight of EL510 manufactured by Toyo Ink Mfg. Co., Ltd. and 90% by weight of A520 manufactured by Mitsui Takeda Chemical Co., Ltd. A decorative sheet was prepared in the same procedure as in Example 1 except that
The decorative sheet of Example 2 was obtained.

<Example 3> A decorative sheet was prepared by the same procedure as in Example 1 except that the composition of the component of the isocyanate compounded in the anchor coat agent used in the anchor coat layer 3 was changed to hexamethyl resin isocyanate alone. Then
The decorative sheet of Example 3 was obtained.

Comparative Example 1 A decorative sheet was prepared in the same procedure as in Example 1 except that a modified polyethylene resin graft-polymerized with maleic anhydride was used as a constituent resin of the adhesive resin layer 4, and a comparison was made. The decorative sheet of Example 1 was obtained.

<Comparative Example 2> In the above-mentioned Example 1, except that a modified homopolypropylene resin graft-polymerized with maleic anhydride was used as the adhesive resin constituting the adhesive resin layer 4.
A decorative sheet was prepared in the same procedure as above to obtain a decorative sheet of Comparative Example 2.

<Comparative Example 3> A decorative sheet was prepared in the same manner as in Example 1 except that EL510 manufactured by Toyo Ink Mfg. Co., Ltd. was used as the main component of the anchor coating agent used in the anchor coating layer 3. A decorative sheet of Comparative Example 3 was obtained.

For each of the decorative sheets obtained in Examples 1 to 3 and Comparative Examples 1 to 3 as described above, 2
Heating in a 3 ° C atmosphere and at 80 ° C for 120 hours, 90
Heating at 120 ° C for 120 hours, heating at 100 ° C for 120 hours,
The laminate strength under each condition of the environmental test of 4 cycles of 80 ° C. for 2 hours and −20 ° C. for 2 hours was measured, and further the time until reaching 1000 N / m in an atmosphere of 23 ° C. was measured. The results are shown in Table 1 below.

[0047]

[Table 1]

[0048]

As described above, since the decorative sheet of the present invention does not use vinyl chloride at all, there is no fear of environmental problems, and appropriate flexibility, abrasion resistance, scratch resistance, chemical resistance, In addition to the post-processability, it has the effect of providing a decorative sheet having heat resistance of 90 ° C. or higher and excellent environment resistance and weather resistance.

Further, the mixture of the polyester polyol, which is the main component contained in the anchor coat layer, and the urethane-modified polyester polyol is mixed at a mixing ratio of 20 to 80% by weight of polyester polyol and 80 to 20% by weight of urethane-modified polyester polyol. By configuring, the strength can be rapidly expressed and the productivity can be improved while maintaining the above performance.

Further, the above-mentioned performance can be obtained by adjusting the mixing ratio of the isocyanate component contained in the two-component curing type anchor coating agent to 30 to 98% by weight of isophorone diisocyanate and 2 to 70% by weight of the other isocyanate component. The strength of each laminate can be further improved while maintaining it.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an example of a decorative sheet according to the present invention.

[Explanation of symbols]

1 ... Substrate sheet 2 ... Pattern layer 3 ... Anchor coat layer
4 ... Adhesive resin layer 5 ... Polypropylene resin layer 5a ... Recessed pattern 6 ... Top coat layer

Continued front page    F term (reference) 4F100 AK01A AK07 AK07B AK41C                       AK51C AL03 AL03B AL05C                       AL07B AT00A BA03 BA07                       BA10B CA05 CA06 CA07                       CA13 CA17 EH20B EJ13                       EJ40 EJ55 EJ65C HB00                       HB31 JB12C JK07 JK09                       JL01 JL09 JN01

Claims (3)

[Claims] 1. An anchor coat layer made of a two-component curing type anchor coat agent is provided on the surface of a base material sheet made of a non-vinyl chloride material, and a random layer modified with an unsaturated carboxylic acid or its anhydride is further provided thereon. In a decorative sheet having at least a polypropylene resin layer coextruded through an adhesive resin layer made of polypropylene resin, a main component of the two-component curable anchor coating agent is a mixture of polyester polyol and urethane-modified polyester polyol. A decorative sheet comprising an isocyanate-curable resin consisting of 2. The mixture of the polyester polyol and the urethane-modified polyester polyol is characterized in that the polyester polyol and the urethane-modified polyester polyol are mixed in a mixing ratio of 20 to 80% by weight and 80 to 20% by weight, respectively. The decorative sheet according to claim 1. 3. The isocyanate component contained in the two-component curing type anchor coating agent comprises isophorone diisocyanate in an amount of 30 to 98% by weight and the other isocyanate components in an amount of 2 to 70% by weight. The decorative sheet according to claim 1 or 2, which is characterized in that.