JP3391187B2 - Decorative sheet - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin decorative sheet for a decorative material such as a plastic decorative plywood or a plastic coated steel plate used for furniture, interior materials for buildings and the like.

[0002]

2. Description of the Related Art In general, a decorative material such as a plastic decorative plywood is one in which a printed or colored single-layer or laminated resin sheet (decorative sheet) is attached to a base material such as wood or a steel plate such as plywood. It is well known that a vinyl chloride resin is widely used as a material for this decorative sheet.

A decorative sheet made of such a vinyl chloride resin is excellent in design since it can be colored arbitrarily and is easy to print, and since it has good adhesiveness with a base material, Widely used as a sheet. However, vinyl chloride resin generates hydrogen chloride gas at the time of incineration and disposal after use, and it takes time and cost to treat it, or in order to prevent damage to the furnace material of the incinerator, it is special. Problems such as the fact that a furnace material must be used have been pointed out, and various uses of polyolefin resins have been proposed.

[0004]

However, in the case of polyethylene, which is the most general-purpose polyolefin resin, high density polyethylene lacks transparency, and low density / medium density polyethylene has good transparency but too low rigidity. It has drawbacks. Further, in the case of polypropylene, the rigidity is high, but the folded whitening property is inferior, and it is insufficient as a decorative sheet.

That is, an object of the present invention is to solve the above problems and to provide a decorative sheet made of a polyolefin resin sheet having good transparency, high rigidity, and less likely to cause whitening due to bending.

[0006]

Means for Solving the Problems The gist of the present invention is (1) polypropyrene having the following characteristics (a) and (b):
A cosmetic sheet made from a base sheet made of ren resin
DOO, the melt flow rate of (a) polypropylene resin
0.1-30, heat of fusion of crystal 30-100 J / g
The elastic modulus is 1000-7000 kg / cm ² ,
One (b) polypropylene resin propylene homopolymer,
Propylene Random Copolymer or Ethylene Propylene
Ren block copolymer or a mixture of two or more of these
Ranaru (2) polypropylene resin with a propylene homopolymer
Above consisting of a mixture of propylene random copolymers
The decorative sheet according to (1), (3) the propylene random copolymer is propylene and ethylene.
Consisting of ren and α-olefin having 4 to 12 carbon atoms
One or more olefinic monomers selected from the group
As described above in (1) or (2), which is a random copolymer with
The tensile elastic modulus of the decorative sheet and (4) base sheet put on is 4000-6800k.
In any of the above (1) to (3), which is g / cm ^2.
It is on the makeup sheet.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
The decorative sheet of the present invention has a sheet made of a specific polypropylene resin (hereinafter referred to as a "base material sheet for decorative material") as a base material. As such a decorative sheet, for example, 1) one in which a printing layer is formed on the surface of the specific base material sheet for a decorative material that is not in contact with the base material, and a transparent surface layer is laminated thereon, 2 ) A print layer is formed on the surface of the specific decorative material base sheet that is in contact with the base material, and a transparent surface layer is formed on the other surface, 3) The surface layer is omitted in 2) above, 4 ) In the above 1) and 2), instead of the printing layer, or in addition to the printing layer, the base material sheet for a decorative material is colored with a pigment or the like.

Generally, a surface layer is provided on the surface of the decorative sheet in order to improve the weather resistance, abrasion resistance, scratch resistance, etc. of the decorative material. This layer is a polyolefin resin, polyester resin, acrylic resin, It can be formed by laminating or coating a urethane resin or the like. Further, since the above-mentioned base material sheet for decorative material has good transparency, a sheet made of the same material as the base material sheet can be used as the surface layer.

Embossing may be applied to the surface layer (in the case of the above 3), the surface of the base material sheet for decorative material having no printing layer). The printing layer can be formed by a transfer method as well as a printing method such as gravure printing, offset printing, offset gravure printing, and silk screen printing using ink in which a pigment or the like is dispersed. . For the purpose of improving the adhesion between the printed layer and the base material sheet for decorative material, it is desirable to subject the surface of the base material sheet for decorative material to corona treatment. Further, it is preferable to provide a primer layer between the base sheet and the printing layer because the adhesiveness between the two is further improved. Examples of the primer layer include a solution containing a chlorinated polyolefin resin, polyester, ethylene-vinyl alcohol copolymer, etc. as a main component, and a filler added thereto if necessary.

The polypropylene-based resin, which is a material of the base material sheet for a decorative material used in the present invention, means a homopolymer of propylene, a copolymer mainly composed of propylene, or a mixture of two or more kinds thereof. Of these, a random copolymer of propylene and one or more olefinic monomers selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms is preferable. In such a random copolymer, due to the irregular arrangement of olefinic monomers in polypropylene, the stereoregularity of the polymer is disturbed and the crystallinity is lowered, and the transparency is good and the flexibility is high. Will be things.

As the olefin-based monomer, it is preferable to use one or more olefin-based monomers selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms. Examples of such α-olefins include butene-1, pentene-1, hexene-1, octene-1, decene-1, dodecene-1. α
-If the number of carbon atoms of the olefin is 13 or more, random copolymerization tends to be difficult, and therefore transparency tends to decrease. The content of the olefinic monomer in the copolymer is 1 to 10% by weight, preferably 2 to 6% by weight.

As described above, the polypropylene resin used in the present invention is preferably a random copolymer, but it is also possible to use a propylene homopolymer, an ethylene / propylene block copolymer, or the like. Even if a mixture of two or more kinds is used, it can be used without problems as long as the melt flow rate, the heat of crystal fusion, and the tensile elastic modulus of the resin as a whole are within the above-mentioned specific ranges.

Generally, when the crystallinity is low, the transparency tends to be good, but when it is made into a sheet, it becomes too soft and only a base sheet for a cosmetic material is insufficient. On the other hand, if the crystallinity is high, the transparency is lowered, which is also undesirable. The crystallinity of the polypropylene resin used in the present invention is represented by the following parameters. That is,
Crystal fusion heat is 30 to 100 J / g, preferably 50 to 1
00 J / g and tensile modulus of 1000-7000 k
g / cm ^2, preferably 2000~6000kg / cm ²
Is in the range of.

The heat of crystal fusion is less than 30 J / g,
Tensile elastic modulus is 1000 kg / cm²Sheets that are less than
Unsuitable as a base sheet for cosmetics because it becomes too flexible
On the other hand, the heat of fusion of crystal is 100 J / g or tensile
Elastic modulus is 7,000 kg / cm ²Larger than the sheet
In addition to decreasing transparency, whitening during bending, especially at low temperatures (0
The whitening property in bending becomes poor.

The polypropylene resin should have a melt flow rate of 0.1 to 30 (unit: g / 10 minutes). When the melt flow rate is less than 0.1, it is difficult to mold and it is difficult to obtain a smooth sheet. On the other hand, if it is more than 30, the melt viscosity becomes too low and it is difficult to form a sheet. The heat of crystal fusion referred to in the present invention is a crystal peak area on a DSC chart when a resin is once melted to a melting point or higher and then cooled at a rate of 10 ° C./min using a differential scanning calorimeter (DSC). It is the value calculated more. Well
In addition, the tensile elastic modulus referred to in the present invention means that of the examples of the present specification.
Described in the column of the example using the sheet created in the column
Is the value obtained by the tensile test.

The polypropylene resin may contain an antioxidant, a weather resistance aid (hindered amine light stabilizer, ultraviolet absorber, etc.), a slip agent, a colorant, a filler, a nucleating agent, etc., if necessary. It can be added within a range that does not impair the purpose and performance. As a method for molding the polypropylene-based resin into a base material sheet for a decorative material, a general sheet molding method may be used and is not particularly limited. For example, a T-die extrusion method, an inflation molding method, a calender molding method and the like can be mentioned.

In the present invention, the thickness of the base material sheet for decorative material varies depending on the layer structure of the decorative sheet and its application,
From the standpoint of strength of the entire decorative sheet, post-processing, and ease of handling, it is preferably about 0.05 to 1 mm. A decorative material can be manufactured by laminating a base material such as plywood or a steel plate on such a decorative sheet using an adhesive, an adhesive or the like.

[0018]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. <Examples 1 to 3, Comparative Examples 1 and 2> A polypropylene resin shown in the table was used, a 40 mmφ T-die extruder (T die: 400 mm width) was used, and a die temperature of 220 ° C., a thickness of 100 μm. A base material sheet for a cosmetic material was prepared.

The following evaluations were performed on the obtained sheets. The results are also shown in the table. <Evaluation method> 1. Melt flow rate: Measured according to JIS K 6758 (and JIS K 7210). 2. Molding processability: The appearance of the T-die molded sheet was visually judged according to the following criteria.

◯: Good Δ: Some flow marks are present ×: Poor fluidity and uneven flow Tensile test: According to JIS Z 1707, a dumbbell No. 1 test piece was used and the tensile speed was measured at 50 mm / min. 4. Folding whitening property: The whiteness of the bent portion when bent 180 degrees in an atmosphere of 0 ° C. was visually judged according to the following criteria.

◯: No whitening △: Some whitening ×: Significant whitening Haze: The haze value was measured according to JIS K 7105. <Preparation of Decorative Sheet and Decorative Material> Using each of the sheets of the above examples as a base material sheet for a decorative material, one side was subjected to corona treatment, and then a primer containing a chlorinated polyolefin resin as a main component was applied. Grain printing was applied to the treated sheet by gravure printing, the same transparent sheet as the above-mentioned base sheet was overlaid again, and then embossed to obtain a decorative sheet.

A corona treatment was further applied to this back surface to apply an adhesive, and a plywood was adhered as a base material to prepare a decorative material. This decorative material has excellent folding whitening resistance of the decorative sheet, so there is no whitening phenomenon at the corners,
It had a good appearance. It should be noted that the decorative material produced from the decorative sheet of the comparative example made by using the base material sheet for decorative material based on the polypropylene resin having the heat of crystal fusion and the tensile elastic modulus outside the preferred range of the present application has a corner portion of the backing material. Whitening occurred and the quality was inferior.

[0023]

[Table 1] * 1 Resin type: SPX; SPX8600 (Mitsubishi Chemical) FY; FY6C (Mitsubishi Chemical) FG3D; (Mitsubishi Chemical) MA3H; (Mitsubishi Chemical) FX4; (Mitsubishi Chemical) F658D; Grand Polymer S / F ; SPX8600 / FY6C weight ratio * 2: MFR: melt flow rate, the unit g / 10 min * 3: heat of crystal fusion: unit J / g * 4: tensile modulus: unit kg / cm ²

[0024]

The decorative sheet obtained by using the base material sheet for a decorative material made of the specific polypropylene resin of the present invention has a low haze and a good transparency, and thus has a good appearance and also has a whitening by bending. Hateful.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuya Ochiai 2 Oike, Iwazuka-cho, Nakamura-ku, Nagoya, Aichi Prefecture Mitsubishi Chemical MKV Co., Ltd. Nagoya Office (72) Inventor Ken Furuya 2 Oike, Iwazuka-cho, Nakamura-ku, Aichi Prefecture Address Mitsubishi Kagaku MKV Co., Ltd. Nagoya Office (56) Reference JP-A-8-90740 (JP, A) JP-A-8-3380 (JP, A) JP-A-8-73528 (JP, A) JP-A 2-160853 (JP, A) JP-A-58-45244 (JP, A) JP-A-7-126460 (JP, A) JP-A-8-112882 (JP, A) Jitsukoku Sho-62-19766 (JP, A) Y1) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08L 23/00-23/36 C08J 5/18

Claims (4)

(57) [Claims] 1. A portable telephone having the following characteristics (a) and (b):
Made using a base sheet made of polypropylene resin
Cosmetic sheet. (A) The polypropylene resin has a melt flow rate of 0.1 to 30, a heat of crystal fusion of 30 to 100 J / g, and a tensile elastic modulus of 1000 to 7000 kg / cm ² .
One (b) polypropylene resin propylene homopolymer,
Propylene Random Copolymer or Ethylene Propylene
Ren block copolymer or a mixture of two or more of these
Consists of 2. The polypropylene resin is propylene alone.
Consisting of a mixture of polymer and propylene random copolymer
The decorative sheet according to claim 1. 3. A propylene random copolymer is propylene.
And ethylene and α-olefins having 4 to 12 carbon atoms
One or more olefins selected from the group consisting of
A random copolymer with a base monomer according to claim 1 or 2.
The described decorative sheet. 4. The tensile elastic modulus of the base sheet is 4000 to 6
It is 800 kg / cm < ² > , Any one of Claims 1-3.
The decorative sheet according to item.