JP3911804B2 - Laminated film for decorative sheet - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin decorative sheet for decorative materials such as plastic decorative plywood and plastic-coated steel plates used for furniture and building interior materials.
[0002]
[Prior art]
In general, decorative materials such as plastic decorative plywood use wood or steel plate such as plywood as a base material, and a single-layer or laminated resin sheet (decorative sheet) that has been printed and colored is pasted on it. As a material of this decorative sheet, there are many examples in which a vinyl chloride resin excellent in designability and adhesiveness is used.
However, in recent years, decorative sheets based on polyolefin resins have been used due to problems such as treatment of hydrogen chloride gas generated at the time of incineration disposal, such as after use, and selection of furnace materials for incinerators used therefor. It has become.
[0003]
[Problems to be solved by the invention]
Ordinary decorative sheets are composed of a transparent surface layer and a printed or colored printed layer, each of which is laminated via an adhesive layer as required, and this laminated sheet is applied to the back side. Alternatively, it is used by being attached to a plywood or the like through a laminated adhesive layer.
In order to prevent such a printed layer from fading and the sheet itself from deteriorating during use, it is common to add a UV absorber as a weather resistance aid to the surface layer or printed layer of the decorative sheet.
[0004]
However, in polyolefin-based decorative sheets, the polyolefin resin that is the base material is non-polar, so the compatibility with high-polarity UV absorbers is low, and an amount that can effectively prevent discoloration and deterioration is blended in the raw material However, when manufacturing and secondary processing the sheet, a phenomenon called “bloom” occurs, which contaminates the surface of the sheet and equipment such as molds and rolls for manufacturing and processing. In many cases, the purpose of the original blending cannot be achieved because the ultraviolet absorber is lost by spraying.
That is, an object of the present invention is to provide a decorative sheet film comprising a polyolefin-based resin sheet that solves the above-mentioned problems, suppresses bloom, and hardly causes fading and deterioration.
[0005]
[Means for Solving the Problems]
The gist of the present invention resides in the following items.
(1) In the laminated film for decorative sheets comprising at least the surface layer (A) and the base material layer (B),
(I) Each of the surface layer (A) and the base material layer (B) has a melt flow rate of 0.1 to 30 (g / 10 minutes), a crystal melting heat of 30 to 150 (J / g), and bending. It consists of a polypropylene film containing a polypropylene resin having an elastic modulus in the range of 5000 to 20000 (kg / cm ² ) and an ultraviolet absorber ,
(Ii) The heat of crystal melting (hereinafter referred to as “ΔHm, _A ”) and the flexural modulus (hereinafter referred to as “Y _A ”) of the polypropylene resin constituting the surface layer (A), and the base material layer (B) The heat of crystal melting (hereinafter referred to as “ΔHm, _B ”) and the flexural modulus (hereinafter referred to as “Y _B ”) of the polypropylene resin constituting the resin are “ΔHm, _A > ΔHm, _B and Y _A > Y _B ”, respectively. meet the relationship, and
(Iii) Content per 100 parts by weight of the polypropylene-based resin of the ultraviolet absorber in the surface layer (A) (hereinafter referred to as “W _A ”) and the polypropylene-based resin 100 of the ultraviolet absorber in the base layer (B) content per part by weight (hereinafter referred to as "W _B"), but "W _a <W _B", characterized in Succoth satisfy the relationship, the laminated film for decorative sheets having a thickness of 0.03～2Mm.
[0006]
(2) W each _A and W _B are cosmetic laminated film sheet according to the above (1) term in the range of 0.01 to 20 parts by weight.
[0007]
( 3 ) The laminated film for decorative sheets according to (1) or (2) above, wherein the ratio of the thickness of the base material layer (B) to the thickness of the laminated film is 50 to 95%.
( 4 ) The polypropylene resin is a random copolymer of propylene and one or more olefinic monomers selected from the group consisting of ethylene and an α-olefin having 4 to 12 carbon atoms. The laminated film for a decorative sheet according to any one of (1) to ( 3 ) above.
[0008]
( 5 ) The laminated film for decorative sheets according to any one of (1) to ( 4 ), wherein the ultraviolet absorber is a benzotriazole-based ultraviolet absorber.
( 6 ) The laminated film for decorative sheets according to the above ( 5 ), wherein the ultraviolet absorber is a benzotriazole ultraviolet absorber having a molecular weight of 380 to 1,000.
( 7 ) The laminated film for a decorative sheet according to any one of (1) to ( 6 ), wherein the polypropylene film contains a hindered amine light stabilizer.
[0009]
( 8 ) An adhesive decorative sheet laminated film in which an adhesive layer is laminated on the base material layer (B) of the decorative film laminated film according to any one of (1) to ( 7 ) above.
(9) A decorative sheet obtained by sequentially laminating a printing layer and an adhesive layer on the adhesive layer of the laminated film for decorative sheet according to ( 8 ) above.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
The laminated film for decorative sheets of the present invention is a film obtained by laminating two kinds of films made of a specific polypropylene resin.
The polypropylene resin that is the material of the laminated film for decorative sheets of the present invention refers to a homopolymer of propylene, a copolymer mainly composed of propylene, or a mixture of two or more of these.
[0011]
The polyolefin resin used in the present invention is a random copolymer of propylene and one or more olefinic monomers selected from the group consisting of ethylene and an α-olefin having 4 to 12 carbon atoms. Is preferred. Examples of the α-olefin include butene-1, pentene-1, hexene-1, octene-1, decene-1, dodecene-1, and the like. When the number of carbon atoms of the α-olefin is 13 or more, random copolymerization tends to be difficult, and the transparency of the film tends to be lowered, which is not preferable.
[0012]
Such a random copolymer has an irregular arrangement of olefinic monomers in the polypropylene molecule, disturbing the stereoregularity of the polymer, lowering the crystallinity, providing good transparency and flexibility. It will be rich. The content of the olefin 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 even if a propylene homopolymer or an ethylene / propylene block copolymer is used, or two or more of the above polypropylene resins are used. Even if this mixture is used, the resin can be used without any problem as long as the melt flow rate, heat of crystal fusion, and bending elastic modulus are within the following specific ranges.
[0013]
The melt flow rate of the polypropylene resin used here needs to be 0.1 to 30 (g / 10 minutes). If the melt flow rate is less than 0.1, it is difficult to form and a smooth film is difficult to obtain. On the other hand, when this is larger than 30, the melt viscosity becomes too low and it is difficult to form the film.
The heat of crystal fusion is 30 to 150 J / g, preferably 80 to 140 J / g, and the flexural modulus is required to be in the range of 5000 to 20000 kg / cm ² , preferably 10,000 to 15000 kg / cm ^2. is there.
[0014]
If the heat of crystal fusion is less than 30 J / g or the flexural modulus is less than 5000 kg / cm ² , the film for a decorative sheet is too flexible and easily causes processing problems. On the other hand, when the heat of crystal melting is increased to 150 J / g or the bending elastic modulus exceeds 20000 kg / cm ² , the transparency of the sheet is lowered, whitening at the time of bending, especially whitening at low temperature (0 ° C.). Tend to be inferior.
[0015]
The heat of crystal fusion referred to in the present invention is the crystal on the DSC chart when the resin is once melted to a melting point or higher using a differential scanning calorimeter (DSC) and then cooled at a rate of 10 ° C./min. It is a value calculated from the peak area.
The laminated film for decorative sheets of the present invention is composed of at least two layers of a surface layer (A) and a base material layer (B). The polypropylene resin used for the surface layer (A) and the base material layer (B) has a heat of crystal melting (ΔHm, _A and ΔHm, _B ) and a flexural modulus (Y _A and Y _B ), respectively. The relationship “ΔHm, _A > ΔHm, _B and Y _A > Y _B ” must be satisfied.
[0016]
Further, these layers need to contain an ultraviolet absorber, and the content (WA and WB) of the ultraviolet absorber per 100 parts by weight of the polypropylene resin in each layer is “WA <WB”. that meet the relationship. The content (WA, WB) of these ultraviolet absorbers is preferably 0.01 to 20 parts by weight, preferably 0.05 to 10 parts by weight per 100 parts by weight of the polypropylene resin in each layer. is there. If the amount of the UV absorber used is less than 0.01 parts by weight, it is difficult to obtain a sufficient UV absorbing effect, and thus the effect of preventing discoloration / deterioration tends to be insufficient. The effect corresponding to the increase in the amount of use cannot be obtained, and the possibility of bloom increases, which is not preferable.
[0017]
The thickness of the laminated film of the present invention is in the range of 0.03 to 2 mm. It is generally difficult to produce a film with a thickness of less than 0.03 mm. On the other hand, when a film with a thickness exceeding 2 mm is used for a decorative sheet, it is difficult to handle the texture and the bent / end portions when applied to a base material. Become.
Moreover, it is preferable that the ratio of the thickness of the base material layer (B) to the thickness of such a laminated film is 50 to 95%. If the ratio of the thickness of the base material layer (B) to the entire laminated film is out of the above range, the balance between the rigidity of the entire laminated film and the bending whitening property will be lost, or the sheet will become too flexible or hard. Too much, it is not suitable for decorative sheets.
[0018]
As an ultraviolet absorber used for the laminated film of the present invention, 2- [2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydrophthalimidomethyl) -5′-methylphenyl] benzotriazole (Molecular weight 388), 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole (molecular weight 448), 2,2-methylenebis [4- (1,1,1, Benzotriazole ultraviolet absorbers such as 3,3-tetramethylbutyl-6- (2H-benzotriazol-2-yl) phenol] (molecular weight 659), and 2,4-dihydroxybenzophenone, 2-hydroxy-4- Methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2,2′-dihydroxy-4-dimethoxybenzophenone, Scan (2-methoxy-4-hydroxy-5-benzoylphenyl) benzophenone ultraviolet absorbers such as methane can be exemplified.
[0019]
Among them, the use of a benzotriazole-based ultraviolet absorber is suitable for reducing the coloration of the product, and the molecular weight thereof is in the range of 380 to 1000, preferably in the range of 400 to 800. Is more preferred. By setting the molecular weight within the above range, the bloom preventing effect is further increased.
The surface layer of the laminated film for decorative sheets of the present invention and the polypropylene film of the base material layer are bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, 2- (3,5-di-t -Butyl-4-hydroxybenzyl) -2-n-butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), dimethyl succinate-1- (2-hydroxyethyl) -4- Hydroxy-2,2,6,6-tetramethylpiperidine polycondensate and poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl } Hindered amine light stabilizers such as {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] Contain When, further preferable because the deterioration of the polypropylene resin itself of the base material can be prevented.
[0020]
The amount of the hindered amine light stabilizer used is preferably 0.01 to 10 parts by weight per 100 parts by weight of the polypropylene resin from the viewpoints of stabilizing effect and prevention of bloom. In particular, it is more preferable to use a hindered amine light stabilizer having a molecular weight of 1000 or more because the hindered amine light stabilizer itself can reduce the bloom.
[0021]
In the polypropylene resin film used in the present invention, an antioxidant, a slip agent, a colorant, a filler, a nucleating agent, etc., as necessary, in addition to the above-mentioned compounding agents, do not impair the purpose of the present invention. You may add.
A method for producing such a polypropylene film is not particularly limited, and a general method for forming a polyolefin resin sheet may be used. Examples thereof include a T-die extrusion method, an inflation molding method, and a calendar molding method.
[0022]
In addition, as a method of laminating the surface layer (A) and the base material layer (B), individual films are formed and bonded together using a laminator, etc. However, it is preferable to form a laminated film at the same time as molding by a two-layer (or multilayer) T-die extrusion method because the number of steps can be reduced.
[0023]
Furthermore, by laminating an adhesive layer on the base material layer (B) of the laminated film for decorative sheets, a laminated film for decorative sheets having adhesiveness can be obtained. A decorative sheet can be obtained by sequentially laminating a printing layer and an adhesive layer on the adhesive layer of the laminated film for adhesive decorative sheet.
In addition, in order to laminate the adhesive layer and the printing layer, a method of co-extrusion of each layer of the laminated film for decorative sheets, a method of press-bonding or fusing at the same time as forming the film, a laminator etc. for a film formed in advance individually Or a method of applying a liquid or paste-like adhesive or printing ink with a coater.
[0024]
This laminated film for adhesive decorative sheets and decorative sheets are blended with UV absorbers with good retention, so there is little deterioration of the adhesive layer, and troubles such as delamination when used as a decorative sheet can be reduced. it can.
A decorative material can be manufactured by sticking such a decorative sheet to a base material such as a plywood or a steel plate.
[0025]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited by the following examples, unless the summary is exceeded.
<Examples 4-6 , Comparative Examples 1-2, Reference Examples 1-3 >
Production of sheet Using the polypropylene resin shown in the table, a sheet (A) and a sheet (A) were formed at a die temperature of 220C in a T-die extruder (double-layer extruder, T-die: 400 mm width) of 40 mmφ + 30 mmφ. The sheet (B) was laminated at the same time as molding to prepare a decorative sheet laminated film having a predetermined layer ratio and an overall thickness of 100 μm.
The following evaluation was performed about the obtained film. The results are shown in the table.
[0026]
Evaluation method 1. Melt flow rate: Measured according to JIS K 6758 (and JIS K 7210).
2. Haze: The haze value was measured in accordance with JIS K 7105.
Evaluation of results The laminated film of the present invention has a small increase in haze after time and a small amount of bloom. In particular, those having a difference in the content of the UV absorber in the surface layer and the base material layer have low initial haze.
[0027]
[Table 1]
[0028]
[Table 2]
[0029]
(Note) (Common to Tables 1 and 2)
Polypropylene resin:
A, C: Propylene homopolymer / ethylene-propylene-random copolymer (1/1)
B, D: ethylene-propylene-random copolymer MFR: melt flow rate bending elastic modulus: unit kg / cm ²
UV absorber:
I: 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole
II: 2,2-methylenebis [4- (1,1,3,3-tetramethylbutyl-6- (2H-benzotriazol-2-yl) phenol]
Hindered amine:
J: dimethyl succinate-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate (molecular weight 3100-4000)
[0030]
【The invention's effect】
A film obtained by laminating a polypropylene resin film of a specific type and composition of the present invention is particularly suitable as a laminated film for a decorative sheet because it has little bloom.

Claims (9)

In the laminated film for decorative sheets comprising at least the surface layer (A) and the base material layer (B),
(1) Each of the surface layer (A) and the base material layer (B) has a melt flow rate of 0.1 to 30 (g / 10 minutes), a crystal melting heat of 30 to 150 (J / g), and bending. It consists of a polypropylene film containing a polypropylene resin having an elastic modulus in the range of 5000 to 20000 (kg / cm ² ) and an ultraviolet absorber ,
(2) Crystal melting heat (hereinafter referred to as “ΔHm, _A ”) and bending elastic modulus (hereinafter referred to as “Y _A ”) of the polypropylene resin constituting the surface layer (A), and the base material layer (B) The heat of crystal melting (hereinafter referred to as “ΔHm, _B ”) and the flexural modulus (hereinafter referred to as “Y _B ”) of the polypropylene resin constituting the resin are respectively “ΔHm, _A > ΔHm, _B and Y _A > Y _B ”. meet the relationship, and
(3) Content of ultraviolet absorber in surface layer (A) per 100 parts by weight of polypropylene resin (hereinafter referred to as “W _A ”) and polypropylene resin 100 of ultraviolet absorber in substrate layer (B) content per part by weight (hereinafter referred to as "W _B"), but "W _a <W _B", characterized in Succoth satisfy the relationship, the laminated film for decorative sheets having a thickness of 0.03～2Mm. W each _A and W _B are laminated film for decorative sheet according to claim 1 which is in the range of 0.01 to 20 parts by weight. The laminated film for a decorative sheet according to claim 1 or 2 , wherein the ratio of the thickness of the base material layer (B) to the thickness of the laminated film is 50 to 95%. The polypropylene resin is a random copolymer of propylene and one or more olefinic monomers selected from the group consisting of ethylene and an α-olefin having 4 to 12 carbon atoms. The laminated film for decorative sheets according to any one of to 3 . The laminated film for a decorative sheet according to any one of claims 1 to 4 , wherein the ultraviolet absorber is a benzotriazole-based ultraviolet absorber. The laminated film for decorative sheets according to claim 5 , wherein the ultraviolet absorber is a benzotriazole ultraviolet absorber having a molecular weight of 380 to 1,000. The laminated film for decorative sheets according to any one of claims 1 to 6 , comprising a hindered amine light stabilizer in the polypropylene film. Decorative base layer of the laminated film sheet (B) adhesive decorative sheet for laminated film adhesive layer are laminated on according to any one of claims 1-7. A decorative sheet in which a printed layer and an adhesive layer are sequentially laminated on the adhesive layer of the laminated film for decorative sheet according to claim 8 .