JP2000319411A - Film for decorative sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve weatherability and concealing properties by setting the product of an average primary particle size of almost spherical titanium oxide and an amount of a surface-treating agent covering the surface thereof at a specific value or more. SOLUTION: There is provided a film, for a decorative sheet, made of a thermoplastic resin containing almost spherical titanium oxide characterized by the equation:A×B>=0.3 (wherein A is an average primary particle size (μm); and B is a coated amount (wt.%) of a surface-treating agent). The surface- treating agent preferably comprises at least one selected among metal phosphates, silicon oxides and metal oxides, and concretely are suitable silica, alumina and a mixture thereof, alumina in particular. Titanium oxide is compounded in an amount of 1-50 wt.% and as the thermoplastic resin is preferable a polyolefinic resin, especially a polypropylenic resin. The film does not generate toxic gases when incinerated. The film for a decorative sheet is useful for a plastic decorative plywood used for furniture and building interior materials and the like, and for facing materials of plastic-coated steel plates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In general, as a decorative material such as a plastic decorative plywood, a printed or colored single-layer or multi-layer resin sheet (so-called decorative sheet) is adhered to a base material such as wood such as plywood or a steel plate. It has been known. Among them, the multi-layer decorative sheet has a transparent surface layer, a layer subjected to printing and / or coloring (hereinafter, referred to as “printing layer”), and each of these layers may be an adhesive layer if necessary. Are laminated through. This decorative sheet is used by being attached to a plywood or the like via an adhesive layer laminated on the back surface (print layer side). As a resin film forming each layer of the decorative sheet, a film made of a thermoplastic resin such as a vinyl chloride resin or a polyolefin resin is widely used because of its excellent design and adhesiveness.

[0003] The coloring of the decorative sheet is carried out by blending a colorant such as a pigment with the film. As the colorant, titanium oxide is widely used as a white pigment having excellent hiding power and coloring power. However, when titanium oxide is blended with the resin, the titanium oxide itself has a high activity on the particle surface, which causes a chemical reaction with the resin and deteriorates the resin, and the dispersibility of the titanium oxide is also poor. Those whose surfaces are coated with various inorganic or organic treating agents are used. However, even when titanium oxide coated with these surface treatment agents is used, the weather resistance of the film cannot be sufficiently satisfied, and even if the problem of the weather resistance can be solved, the problem that the concealing property of the film is poor is caused. there were.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a film for a decorative sheet made of a thermoplastic resin which is excellent in weather resistance and hiding properties.

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and have found that titanium oxide is blended so that the average particle diameter and the coating amount of the surface treating agent satisfy a specific relationship. As a result, it has been found that a film for a decorative sheet excellent in both concealing property and weather resistance can be obtained, and the present invention has been accomplished. That is, the gist of the present invention resides in a thermoplastic resin decorative sheet film containing substantially spherical titanium oxide and having the following characteristics (a). (A) The surface of the titanium oxide particles is coated with a surface treatment agent, and the average primary particle diameter of the titanium oxide and the coating amount of the surface treatment agent satisfy the following formula:

[0006]

A × B ≧ 0.3 (where A is the average primary particle diameter of titanium oxide (μm),
B is the coating amount (% by weight) of the surface treatment agent)

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the thermoplastic resin used for the film for a decorative sheet of the present invention include vinyl chloride resins and polyolefin resins. It is preferable to use a polyolefin resin because no harmful gas is generated when incinerated. Examples of the polyolefin resin include a polyethylene resin, a polypropylene resin, and a mixture thereof.

[0008] As the polyethylene resin, a homopolymer of ethylene and / or a copolymer of ethylene and another monomer copolymerizable with ethylene (low-density polyethylene (LDPE) , Linear low density polyethylene (LLDPE), high density polyethylene (HDP)
E), polyethylene or the like obtained by polymerization using a metallocene catalyst), or a mixture (polymer blend) of the homopolymer and / or copolymer with another polymer. Examples of the polymer that can be mixed with the homopolymer and / or the copolymer to give a polymer blend include, for example, isoprene rubber, butadiene rubber,
Diene rubbers such as butyl rubber, propylene-butadiene rubber, acrylonitrile-butadiene rubber, acrylonitrile-isoprene rubber, and polyolefin-based heats such as ethylene-propylene copolymer rubber, ethylene-propylene non-conjugated diene rubber, and ethylene-butadiene copolymer rubber And a styrene-based thermoplastic elastomer such as a styrene-butadiene-based or styrene-isoprene-based thermoplastic elastomer. Among them, a styrene-butadiene-based thermoplastic elastomer is preferable. The styrene-based thermoplastic elastomer is preferably hydrogenated. The amount of the polymer to be mixed is preferably from 5 to 80% by weight.

Examples of the polypropylene resin include a homopolymer and / or copolymer of propylene, and a mixture (polymer blend) of the homopolymer and / or copolymer with another polymer. Examples of the copolymer include a random copolymer or a block copolymer of propylene and ethylene or another α-olefin, or a propylene graft copolymer having a polyolefin copolymer as a trunk polymer. . Among them, a random copolymer is preferred because the transparency and flexibility of the film are improved. Α- copolymerizable with propylene
As the olefin, those having 4 to 12 carbon atoms are preferable. For example, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1-
Examples thereof include pentene and 1-decene, and one or a mixture of two or more thereof is used. The mixing ratio of the α-olefin is preferably 1 to 10% by weight, particularly preferably 2 to 6% by weight based on propylene.

Examples of the polyolefin copolymer for the backbone polymer of the propylene graft copolymer include ethylene-propylene rubber, ethylene-butene rubber, and ethylene-propylene-diene rubber. Examples of the polymer which can be mixed with a propylene homopolymer and / or copolymer to give a polymer blend include the same polymers as those mixed with the above-mentioned polyethylene resin, and among them, styrene-butadiene type Thermoplastic elastomers are preferred. The styrene-based thermoplastic elastomer is preferably hydrogenated. The amount of the polymer to be mixed is preferably 5 to 80% by weight, more preferably 2 to 80% by weight.
0-60% by weight is preferred. The titanium oxide blended in the decorative sheet film is a titanium oxide that is substantially spherical and that satisfies the following formula, which is coated with a surface treatment agent.

[0011]

A × B ≧ 0.3 (where A is the average primary particle diameter of titanium oxide (μm),
B is the coating amount of the surface treating agent (% by weight)

When the product of A and B is less than 0.3, the coating amount of the surface treating agent with respect to the specific surface area of titanium oxide is not sufficient, and the weather resistance of the decorative sheet film is poor. Further, the product of A and B is preferably 5 or less, and particularly preferably 1 or less. When 0.3 ≦ A × B ≦ 5, a film for a decorative sheet having excellent weather resistance and hiding properties can be obtained.
The average primary particle diameter of titanium oxide is preferably from 0.01 to 1 μm, particularly preferably from 0.1 to 0.5 μm.
If the average primary particle size is less than 0.01 μm or more than 1 μm, the film may have poor concealing properties.

The coating amount of the surface treating agent is preferably 0.01 to 10% by weight, particularly preferably 0.1 to 5% by weight, and more preferably 1 to 3% by weight. If the amount of the surface treatment agent is less than 0.01% by weight, the weatherability of the decorative sheet film may not be sufficiently improved. If the amount is more than 10% by weight, moisture may be absorbed and foaming may occur when the film is formed. is there.

In the present invention, the coating amount of the surface treatment agent is the weight ratio (% by weight) of the surface treatment agent to the total weight of titanium oxide and the surface treatment agent. The “primary particles” described above are particles in the minimum unit that can be determined as individual particles when observed with a transmission electron microscope, and are not partially sintered or aggregated particles. The term “substantially spherical” is an expression that is clearly distinguished from those having anisotropy, and may not necessarily be spherical but may be rectangular or irregular. The term “coating” means that the surface treating agent is present or adsorbed on the surface of the titanium oxide particles in an island shape or exists as a continuous layer.

As the titanium oxide, for example, titanium chloride,
An aqueous solution of a soluble titanium compound such as titanyl sulfate or organic titanate is mixed with a neutralizing agent to carry out neutralization hydrolysis, and the resulting hydrolyzate is calcined, or so-called chlorine for vapor-phase oxidation of titanium halide. A crystal produced by the method can be used, and the crystal form may be any of an anatase type and a rutile type, and may be a mixture thereof.

Examples of the surface treatment agent include those generally used as a surface treatment agent for titanium oxide. Examples of such agents include metal phosphates, fatty acids and metal salts thereof, silicon oxides, metal oxides, and polyol-based, amine-based, and silicone-based organic treating agents. Note that silicon oxide is obtained by drying hydrated silicon oxide or silicon hydroxide, and metal oxide is obtained by drying hydrated oxide or hydroxide of metal. In addition, it includes at least one of oxides, hydrated oxides, and hydroxides, including that all are hydrated oxides or hydroxides, and the coating amount is converted to oxides. In addition, as metal of phosphate metal salt, fatty acid metal salt and metal oxide, aluminum, zirconium, tin,
Examples include titanium, cerium, zinc, and iron.

Among these surface treatment agents, silica (S
iO ₂ ), alumina (Al ₂ O ₃ ) and mixtures thereof are preferred, and alumina is particularly preferred because of its good dispersibility. To coat titanium oxide with a surface treatment agent, for example, when the surface treatment agent is a metal oxide, a water-soluble metal compound (metal halide, sulfate, etc.) is added to an aqueous dispersion of titanium oxide. After neutralization by adding an alkali or an acid, the neutralized reaction product is separated from the dispersion, washed, dried, and pulverized, whereby the titanium oxide surface-coated with the surface treating agent is added. can get.

The amount of titanium oxide coated on the surface can be appropriately selected depending on the color of the target film, but is usually about 1 to 50% by weight, preferably 5 to 25% by weight. It is preferable to add a hindered amine light stabilizer to the decorative sheet film of the present invention in order to further improve the weather resistance of the film. As the hindered amine-based light stabilizer, those having a molecular weight or an average molecular weight of 2,000 or more are preferably used, such as poly [[6- (1,1,3,3-tetramethylbutyl) amino- 1,3,5-triazine-2,4
-Diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6
-Tetramethyl-4-piperidyl) imino]], dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine succinate, N, N'-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (1,2,
2,6,6-pentamethyl-4-piperidyl) amino]
-6-chloro-1,3,5-triazine condensate, 1,
2,3,4-butanetetracarboxylic acid and 1,2,2
6,6-pentamethyl-4-piperidinol and 3,9
-Bis (2-hydroxy-1,1-dimethylethyl)-
Mixed esterified product with 2,4,8,10-tetraoxaspiro [5,5] undecane, poly [[6-morpholino-s-triazine-2,4-diyl] [(2,2
6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]]. Among them, dimethyl succinate-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, N, N'-bis (3-aminopropyl) ethylenediamine-2,4 -Bis [N-butyl-N- (1,2,
2,6,6-pentamethyl-4piperidyl) amino]-
The 6-chloro-1,3,5-triazine condensate is particularly preferred. In addition, a film obtained by copolymerizing a hindered amine-based light stabilizer having an unsaturated group with a polyethylene resin, particularly a copolymer obtained by copolymerizing 1 to 10% by weight, has a film having weather resistance and discoloration resistance, and titanium oxide. Is preferable because the dispersibility of the polymer becomes good and blooming is difficult to occur.

The amount of the hindered amine light stabilizer is as follows:
It is preferably from 0.01 to 10% by weight, particularly preferably from 0.05 to 5% by weight. If the amount is less than 0.01% by weight, the effect of the hindered amine light stabilizer may not be obtained. If the amount is more than 10% by weight, the film surface may bloom. Further, additives such as an ultraviolet absorber, an antioxidant, a slip agent, a coloring agent, a filler, and a nucleating agent may be added to the film for a decorative sheet of the present invention, if necessary.

The decorative sheet film of the present invention is prepared by mixing a titanium oxide surface-coated on a thermoplastic resin and various additives as required by a master batch or the like, and then extruding a T-die, an inflation molding method and a calendering method. And the like. The thickness of the film is not particularly limited.
It is preferable to set the degree. The film for a decorative sheet of the present invention can be used as a single-layer decorative sheet by performing printing or the like on the surface as necessary. Further, it may be used as a colored layer of a multi-layer decorative sheet. Further, a decorative material can be obtained by laminating a base material such as plywood or a steel plate on the decorative sheet via an adhesive layer.

[0021]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. Examples 1 to 5 and Comparative Examples 1 to 5 <Preparation of Film for Decorative Sheet> Using a composition having the composition described below, a T-die extruder (Pla Giken Co., Ltd.)
(400mm width, die temperature 230 ° C), thickness 8
A 0 μm film was made. The details of the titanium oxide and the hindered amine light stabilizer are as shown in Table 1. Composition : Polypropylene resin (random polypropylene: comonomer; ethylene) 100 parts by weight Titanium oxide (surface treatment agent: described in Table 1) 7.2 parts by weight Hindered amine light stabilizer 0.4 parts by weight

<Evaluation of Performance> 1) Weather Resistance The obtained film was subjected to an accelerated weather resistance test (ultraviolet radiation intensity 90) using a super-accelerated weather resistance tester (Daipla Wintes KU-R4 type “Dipra Metal Weather”).
mW / cm ² , black panel temperature 63 ° C., irradiation 5 hours + condensation 1 hour = 1 cycle = 72 cycles in total), and then a tensile test using a tensile tester (Model 57 manufactured by Kamishima Kikai Co., Ltd.). (The film having the shape shown in JIS K 6732 was used as a test piece and pulled in the film length direction at a speed of 200 mm / min.), And the elongation (%) up to breakage was measured.

[0023]

[Table 1]

[0024]

The film for a decorative sheet of the present invention has excellent weather resistance and concealability, and thus is usefully used as a decorative material.

Continuation of the front page (72) Inventor Somoto Nakai 2nd Oike, Iwazuka-cho, Nakamura-ku, Nagoya-shi, Aichi F-term (reference) 4F071 AA15 AA20 AB17 AB25 AB26 AE22 AF57 AH03 BB04 BB06 BB09 BC01 4J002 AC03X AC06X AC07X AC08X BB03W BB12W BB15W BC05X BG10X BN06W BP02W DE136 FB076 GL01 4J037 AA22 CA09 CA12 CA22 CA23 CA24 CC12 DD05 EE03 EE28 EE33 EE35 EE43 FF02 FF22

Claims (7)

[Claims] 1. A film for a thermoplastic resin decorative sheet containing substantially spherical titanium oxide having the following characteristic (a): (A) The surface of titanium oxide is coated with a surface treatment agent, and the average primary particle diameter of titanium oxide and the coating amount of the surface treatment agent satisfy the following formula: A × B ≧ 0.3 , A is the average primary particle diameter (μm) of titanium oxide,
B is the coating amount (% by weight) of the surface treatment agent) 2. The film for a thermoplastic resin decorative sheet according to claim 1, wherein the surface treatment agent comprises one or more selected from metal phosphates, silicon oxides and metal oxides. 3. The thermoplastic resin decorative sheet film according to claim 2, wherein the metal of the metal oxide is aluminum. 4. The film for a thermoplastic resin decorative sheet according to claim 1, wherein the surface treatment agent is alumina, silica or a mixture thereof. 5. The content of titanium oxide is 1 to 50% by weight.
The thermoplastic resin decorative sheet film according to any one of claims 1 to 4. 6. The thermoplastic resin decorative sheet film according to claim 1, wherein the thermoplastic resin is a polyolefin resin. 7. The film for a thermoplastic resin decorative sheet according to claim 6, wherein the polyolefin resin is a polypropylene resin.