JP2001253022A - Wood flour-containing plastic film reduced in surface flaw and excellent in design effect and method of manufacturing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wood flour-containing plastic film reduced in surface flaw and excellent in design effect, having a woody feeling and used for decoration, for example, used for the lamination to a metal, a woody material and an inorganic material, and a method for manufacturing the same. SOLUTION: The wood flour-containing plastic film reduced in surface flaw and excellent in design effect is constituted by laminating an upper layer comprising a back-printed transparent thermoplastic resin film with a thickness of 0.01-0.2 mm on a lower layer comprising a thermoplastic resin film with a thickness of 0.05-0.5 mm comprising a resin containing 7 weight% or more of wood flour with a particle size of 2-300 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wood powder-containing plastic film having a small number of surface defects and excellent design, for example, for laminating to a metal, wood material or inorganic material, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, attempts have been made to impart surface characteristics close to those of natural wood to synthetic resin moldings to make the surfaces of various furniture, decorative panels, and daily necessities like natural wood. I have. In order to obtain such a wood-like resin product similar to natural wood, it is necessary to add a required amount of wood flour to a synthetic resin molded product in order to obtain a wood-like appearance by coloring it in a color tone similar to wood. Pigments corresponding to the desired color are added to the molding resin material, and the woodgrain pattern is further complemented by printing or embossing to obtain a resin molded product having a color tone, appearance and texture close to the intended natural wood.

[0003]

However, when wood flour is added, the viscosity when heated and melted becomes higher than when wood flour is not added. The problem that air trapped during kneading work during molding is difficult to escape, remains in the film, causes pinholes, and causes moisture etc. to reach the substrate to be laminated through the pinholes, causing corrosion and the like. There is.

Also, wood flour has a property that particles are agglomerated with each other, and it is impossible to completely disperse the elementary particles even if they are kneaded no matter how the film is formed. For this reason,
As shown in FIG. 4, the resin film 1 containing wood flour is
The surface is uneven and the smoothness is slightly inferior. When printing is performed on a resin film having an uneven surface, a portion where the printing plate cylinder cannot contact the concave portions of the surface is generated. This causes a problem that a beautiful printed pattern cannot be obtained.

[0005]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have intensively developed and as a result, a transparent film is doubled on a film to which wood flour is added, so that pinholes such as corrosion can be prevented. In addition to solving related problems, the back side of the transparent film, that is, the surface on the side to be bonded with the wood flour-added film, is printed. An object of the present invention is to provide a powdered plastic film and a method for producing the same. Furthermore, embossing, wiping, or valley printing can be additionally performed to further improve the design of the surface.

[0006] Products obtained by laminating these plastic films may be subjected to post-processing such as bending. At this time, the upper film has better workability than the lower film containing a large amount of filler such as wood flour. The present inventors have also found that there is also an effect of suppressing defects such as cracks and whitening generated in the lower film by processing, and it has been found that a wood powder-containing plastic film having few surface defects and excellent design properties and a method for producing the same can be provided.

The gist of the present invention is as follows: (1) Wood powder having a particle size of 2 to 300 μm is 7% by weight based on resin.
The lower layer contains a thermoplastic resin film having a thickness of 0.05 to 0.5 mm containing the above, and the upper layer has a thickness of 0.01 to 0.2 mm.
A plastic film containing wood flour, characterized by having a small number of surface defects and excellent design characteristics, characterized by laminating a transparent thermoplastic resin film. (2) The plastic film containing wood powder excellent in design with few surface defects as described in (1) above, wherein printing is performed on a surface to be bonded to the lower film of the upper film.

(3) The plastic film containing wood powder excellent in design with few surface defects as described in (1) or (2), wherein the surface of the upper film is embossed. (4) The plastic film containing wood powder excellent in design with few surface defects as described in (1) or (2) above, wherein the surface of the upper film is embossed and the printing ink is transferred to the embossed concave portions.

(5) A thermoplastic resin film having a thickness of 0.05 to 0.5 mm containing 7% by weight or more of wood powder having a particle size of 2 to 300 μm with respect to the resin, and a thermoplastic resin film having a thickness of 0.01 to 0.2 mm. A method for producing a wood flour-containing plastic film having a small number of surface defects and excellent design, characterized in that a transparent thermoplastic resin film is heated and pressed to form two layers. (6) Wood powder of 2 to 300 μm in particle size is 7% by weight based on resin.
By providing an adhesive layer in the middle of the thermoplastic resin film having a thickness of 0.05 to 0.5 mm and a transparent thermoplastic resin film having a thickness of 0.01 to 0.2 mm, and then pressing the adhesive layer 2 A method for producing a wood flour-containing plastic film which is characterized by being layered and has few surface defects and excellent design properties.

(7) A wood excellent in design with few surface defects as described in (5) or (6), wherein printing is performed in advance on the side to which the transparent film is to be bonded, followed by heat-compression. Manufacturing method of plastic film with powder. (8) The method for producing a wood powder-containing plastic film described in (5) to (7), which has a small number of surface defects and is excellent in design, wherein the transparent film is pressure-bonded and then embossed. (9) After crimping a transparent film, emboss processing,
(5) The method for producing a plastic film containing wood powder excellent in design as described in (5) to (7), wherein the printing ink is transferred to the embossed concave portions.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a view showing a process for producing a plastic film according to the present invention. As shown in FIG. 1, the raw wood powder in a coarsely crushed state prepared by mechanically crushing a tree or a chip is repeatedly crushed and classified using a dry ball mill, and the particle size is set to 300 μm or less and 2 μm or more, In addition, a lower layer film is obtained by kneading a fine powder having a water content of 2.0% by weight or less.

The reason why the particle size of the pulverized wood powder is 300 μm or less is necessary in order to uniformly disperse the pulverized wood powder in the resin when the compounding object is a plastic film formed by injection molding or extrusion molding. If the particle size exceeds the above range, the surface of the soft sheet may be roughened and the woody feeling may be reduced. In addition, the reason why the particle diameter is 2 μm or more is that
This is because properties close to those of natural wood cannot be imparted in production and natural wood. Next, if the amount of the woody powder used is less than 7% by weight of the resin, properties close to those of natural wood cannot be imparted. If the amount is too large, the melt viscosity of the resin increases, making melt molding difficult. So, 7-50 for resin
% By weight.

[0013] For 7 to 50 parts by weight of such wood flour,
For example, 100 parts by weight of a resin, an appropriate amount of a stabilizer, a filler, a processing aid, and if necessary, an ultraviolet absorber, a plasticizer, and the like are mixed, and calendered or extruded to form a film. The resin is not particularly limited as long as it is a thermoplastic resin, and polyvinyl chloride resin, polyethylene resin, polypropylene resin, ABS resin, polycarbonate resin, polyurethane resin, polyester resin, acrylic resin, polyamide resin, fluororesin, or the like, or A thermoplastic resin such as a resin polymer blend can be used.

As the plasticizer, for example, phthalates such as dibutyl phthalate, diisobutyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate, dinonyl phthalate and diisodecyl phthalate, which are used for polyvinyl chloride resin, are used. Acid ester plasticizers, adipate ester plasticizers such as di-2-ethylhexyl adipate and diisononyl adipate, other sebacate ester plasticizers, maleate ester plasticizers, fumarate ester plasticizers, trimellitate ester plasticizers Agents, citrate-based plasticizers, and the like.

Further, the pigment to be used is not particularly limited, and any of inorganic and organic pigments used in plastic molding materials and paints can be used. on the other hand,
An appropriate amount of a stabilizer, a filler, a processing aid, and if necessary, an ultraviolet absorber, a plasticizer, and the like are mixed with the transparent upper film resin, and calendered or extruded to form a film. Further, a pigment or dye may be added to the transparent film as long as the transparency is not impaired, so that a colored transparent film can be obtained.

Printing is performed on the lower surface of the transparent upper film, that is, the surface to be doubled with the lower film. The printing ink to be used is not particularly limited. Acrylic resin, vinyl chloride resin, polyester resin, urethane resin, fluorine resin, etc., polyvinyl chloride resin, polyethylene resin, polypropylene resin, ABS resin, polycarbonate resin Printing inks commonly used for polyurethane resins, polyester resins, acrylic resins, polyamide resins, fluororesins and the like can be used. Also, the printing method can be applied without any particular restrictions, such as gravure printing, planographic printing, letterpress printing, screen printing. Printing may be omitted depending on the application.

The reason why the thickness of the thermoplastic resin film containing wood flour is set to 0.05 to 0.5 mm is as follows.
If it is less than 1, the strength of the film is low due to the addition of wood flour, making it difficult to form a stable film. In addition, when forming a film exceeding 0.5 mm, especially when kneading work when forming into a film with a calender roll, too much air is taken in, and not only a pock-like surface state is obtained, but also the workability of the film becomes poor. There is a problem of remarkable reduction.

The reason why the thickness of the upper transparent thermoplastic resin film is set to 0.01 to 0.2 mm is as follows.
If the thickness is less than m, wrinkles and the like occur during printing and embossing and doubling, making it difficult to produce a uniform doubling film. This is because the function of the upper film, which covers the existing pinholes and protects the printing layer, is not improved, but only increases the cost.

FIG. 2 is a view showing a state of a two-layered film according to the present invention. As shown in FIG. 2, a thermoplastic resin film 2 containing wood flour is used as a lower layer, and a transparent thermoplastic resin film 1 is used as an upper layer. In this case, the thickness of the film containing wood flour is 0.05 to
By making it as thin as 0.5 mm, there is an effect of pushing out the trapped bubbles 6. Further, by superimposing the transparent film on the wood-floured film, even if the wood-floured film has a pinhole 7, it is possible to prevent the pinhole 7 from being formed as a penetrating pinhole and consequently causing corrosion. .

A print 3 is applied to the lower surface of the upper transparent film. Since it is easier to perform printing pattern matching and color tone management on a colored film, it is common to apply printing to the lower film surface with a normal printing film, but in the case of a film containing wood powder, the surface is uneven. Therefore, fine print unevenness called omission occurs, and it is difficult to perform uniform printing. Such a printing defect is a fatal defect for an application requiring a special design property such as an interior building material or a container, and it is necessary to solve the defect.

In the present invention, instead of applying a printing pattern to the lower layer film, printing is performed on the lower surface of a transparent and smooth film,
A method of doubling this backprint transparent film to a lower film containing wood flour was proposed. As a result, a plastic film containing wood flour free of printing defects such as omission was successfully obtained. In this method, there is a transparent plastic film layer outside the printing ink layer,
The printed pattern is not only worn for a long time without being rubbed and consumed, but also because the printed pattern can be seen through the transparent layer, there is an advantage in terms of design such as a sense of depth.

Furthermore, it is possible to enhance the design by embossing the surface of the transparent film. Embossing includes a method of doubling a transparent film which has been embossed in advance, and a method of embossing after doubling. Further, when the embossing is a conduit embossing, the wood texture can be further enhanced by embedding the dark color ink in the conduit portion by wiping.

The lower layer film containing wood flour and the transparent upper layer film are formed into two layers by a method suitable for the resin to be used, any one of heat lamination, dry lamination, extrusion lamination, and coextrusion lamination. Thermal lamination is performed by heating the upper layer or lower layer or both films to a temperature higher than the thermal softening temperature, pressing the film with a roll or the like, and then cooling.
This is a method of forming a layer film. Dry lamination is a method of forming a two-layer film by applying a thermoplastic or thermosetting adhesive to the surface of either the upper layer or the lower layer to be laminated, drying and applying heat and pressure while overlapping the other film. is there. If necessary, a heat aging treatment may be performed.

Extrusion lamination is a method in which a lower layer film composition is extruded onto a film from an upper layer film through a T-die or the like, pressed, and cooled to form a two-layer film. For films that do not require printing,
The upper layer film composition is extruded on the lower layer film from a T-die or the like onto a film, and then pressed and cooled to form a two-layer film by extrusion lamination or an extruder having two dies to extrude the upper and lower layers. A co-extrusion lamination method for obtaining a two-layer film is also applicable.

In addition, a so-called wiping process for forming a concavo-convex pattern on the surface of the transparent film by embossing or transferring a printing ink to a concave portion of the emboss, or valet printing for performing printing synchronized with the emboss pattern at the same time as embossing is applied. Is also possible. Further, it is possible to apply a clear coat in the sense of protecting these print layers. These embossing, wiping, valley printing, and top coating may be performed after forming two layers. Alternatively, the clear film may be formed into two layers after performing these processing.

FIG. 3 is a schematic diagram showing a cross section of a film formed into two layers by dry lamination, that is, a film provided with an adhesive layer 4 in the middle. As shown in FIG. 3, a 0.05 to 0.5 mm thick thermoplastic resin film 2 containing wood flour is used as a lower layer, and a 0.01 to 0.2 mm thick transparent thermoplastic resin film 1 is used. It shows a structure in which an adhesive layer 4 is provided between the upper layer of the resin film 2 containing wood powder and the lower layer of the transparent resin film 1 and then pressed to form a two-layer structure. ing.
Thereby, the adhesive effect between the upper layer and the lower layer is provided, and the peeling resistance effect as a whole is improved.

The adhesive is a thermoplastic adhesive.
For example, polyvinyl acetate, polyvinyl alcohol, acrylic adhesive, polyethylene, polyvinyl chloride, etc.,
Any of a thermosetting adhesive such as a melamine resin, a phenol resin, an epoxy resin, and a polyurethane resin may be used. By using this adhesive in the middle between the upper surface of the resin film 2 containing wood powder and the lower surface of the transparent resin film 1, an adhesive effect between the upper layer and the lower layer is provided, and the peeling effect as a whole is improved. It is a thing.

FIG. 4 is a schematic view showing a conventional plastic film containing wood flour. Since the surface of the plastic film containing the wood powder is uneven, the printing ink layer 3 partially has a missing defect 8. Also, since the pinholes 7 present in the plastic film containing wood powder penetrate, laminating this film on a metal plate has a disadvantage that corrosion is likely to occur when placed in a corrosive environment.

[0029]

The present invention will be specifically described below with reference to examples. Table 1 shows the pinhole property, printing defect (missing), and texture of the film in which the upper resin and the lower resin having the composition shown in Table 1 were bonded. At this time, the pinhole property, printing omission and texture were evaluated according to the following criteria. Pinhole property ○: No pinhole is generated. X: It was recognized that many pinholes were generated. Occurrence of printing omission: Not recognized. ×: Many occurrences were observed. Texture ：: Determined by visual and tactile sensations, has a woody feel, no apparent unevenness, is smooth and has excellent appearance. Δ: Judged by visual and tactile sensations, slightly uneven, with some unevenness observed. X: Judgment was made by visual and tactile sensations, and was clearly uneven,
Some unevenness was observed.

[0030]

[Table 1]

As shown in Table 1, as shown in FIG. Nos. 1 to 13 are examples of the present invention. 14 to 29 are comparative examples. No.
Nos. 14 to 29 do not constitute a lower layer, but are composed of one layer of a resin film containing wood flour. 14, 1
In the cases of 8 to 21 and 24 to 29, it was recognized that pinholes were generated. No. In the case of 14-21,
In each case, print omission occurred. In addition, No. 16, 1
In the case of Nos. 7, 22 to 23, the visual and tactile evaluations showed that the surface appearance was non-uniform and the feeling was poor.

[0032]

As described above, according to the present invention, even if it is a thermoplastic resin film containing wood flour, there is no pinhole, and even if it is, it does not reach the through pinhole and has excellent corrosion resistance. In addition, it has an extremely excellent effect of being able to provide a thermoplastic resin film having a woody feel with excellent design properties.

[Brief description of the drawings]

FIG. 1 is a view showing a process for producing a plastic film according to the present invention.

FIG. 2 is a diagram showing a state of a two-layered film according to the present invention.

FIG. 3 is a film laminated into two layers by dry lamination,
That is, it is a schematic view showing a cross section of a film according to the present invention in which an adhesive layer is provided in the middle.

FIG. 4 is a view showing a state of a printed thermoplastic resin film containing conventional wood powder.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transparent thermoplastic resin film 2 thermoplastic resin film containing wood powder 3 printing ink layer 4 doubling adhesive layer 5 emboss 6 air bubble 7 pinhole 8 print missing

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takashi Suzuki 2-4-5 Takaido East, Suginami-ku, Tokyo Misawa Homes Co., Ltd. (72) Inventor Shoji Oka 3-29-1 Kimitsudai, Kimitsu-shi, Chiba ( 72) Inventor Tomoki Kaga 1315-1 Itado Market, Sodegaura City, Chiba Prefecture (72) Inventor Junichi Shibuya 1-117, Takebuchi Nishi, Yao City, Osaka Prefecture 591 F term (for reference) 2B250 AA13 BA03 CA11 DA04 EA01 EA13 FA18 FA21 FA28 FA31 FA33 GA03 4F100 AK01A AK01B AK15A AK15B AP01A BA02 BA10A BA10B BA15 CA04A CA13A CB00 DE01A EC032 EC041 J182 GBH EJB31 EJ172 GB EJ172 GB YY00A

Claims (12)

[Claims] 1. A lower layer comprising a thermoplastic resin film having a thickness of 0.05 to 0.5 mm containing 7% by weight or more of wood powder having a particle size of 2 to 300 μm with respect to a resin, and an upper layer having a thickness of 0.01 to 0.5 mm.
A wood flour-containing plastic film having a small surface defect and excellent design characteristics, characterized by laminating a transparent thermoplastic resin film of 0.2 mm. 2. The wood powder-containing plastic film as claimed in claim 1, wherein the surface of the upper film is bonded to the lower film, and the surface of the upper film is printed. 3. The wood flour-containing plastic film according to claim 1, wherein the upper layer film is embossed. 4. The plastic film with wood flour having less surface defects and excellent design properties according to claim 1 or 2, wherein the upper layer film is embossed and the printing ink is transferred to the embossed concave portions. 5. The plastic film containing wood flour according to claim 1, wherein the upper film is a non-plastic film. 6. A thermoplastic resin film having a thickness of 0.05 to 0.5 mm containing 7% by weight or more of wood powder having a particle size of 2 to 300 μm with respect to the resin, and a transparent film having a thickness of 0.01 to 0.2 mm. 2 by thermocompression bonding with a suitable thermoplastic resin film
A method for producing a wood flour-containing plastic film which is characterized by being layered and has few surface defects and excellent design properties. 7. A thermoplastic resin film having a thickness of 0.05 to 0.5 mm containing 7% by weight or more of wood powder having a particle size of 2 to 300 μm and a transparent resin having a thickness of 0.01 to 0.2 mm. A method for producing a wood flour-containing plastic film having few surface defects and excellent design properties, characterized in that an adhesive layer is provided in the middle of a suitable thermoplastic resin film and then pressure-bonded to form two layers. 8. The plastic film containing wood flour having a small number of surface defects and excellent in design properties according to claim 6 or 7, wherein the transparent film is pre-printed on the side to be bonded and then heat-pressed. Manufacturing method. 9. The wood flour according to claim 6, wherein the embossing is performed after the embossed transparent film is pressed or the transparent film is pressed. Production method of plastic film containing. 10. A plastic film containing wood flour having a small number of surface defects and an excellent design property according to claim 6, wherein a transparent film having the printing ink transferred thereon is embossed and pressure-bonded to the embossed concave portion. Manufacturing method. 11. The method according to claim 6, wherein the transparent film is pressed and then embossed, and the printing ink is transferred to the embossed recesses. Manufacturing method of plastic film. 12. The method according to claim 6, wherein the transparent film is a non-plastic film.