JP3931939B2 - Method for producing film with excellent surface processability - Google Patents

Description

【００２０】
［評価の結果］
実施例１〜３に示す本発明では、剥離が発生せずに良好な結果が得られたのに対し、比較例１〜５に示す従来例では、剥離やプライマー層の凝集破壊が発生し、満足な結果が得られなかった。
【００２１】
【発明の効果】
本発明によれば、基材フィルムの表面に形成された樹脂をプライマー処理した層とその後の工程で積層される樹脂との接着性を格段に向上させることができるので、ハードコート加工や印刷加工等にも適用でき、表面加工性に優れたフィルムの製造方法を提供できる。
【図面の簡単な説明】
【図１】 本発明のフィルムの一例を示す部分断面説明図である。
【符号の説明】
１ フィルム
２ 基材フィルム
３ 樹脂層
４ ハードコート層
５ 小孔[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a film having excellent surface processability, and in particular, it is aimed at hard coat processing or design for the purpose of preventing damage to the film surface using a fluororesin film or an olefin resin film as a base material. The present invention also relates to a film excellent in surface workability with good adhesion even when using an adhesive such as printing or laminating a film of a substrate and another film.
[0002]
[Prior art]
Conventionally, examples of the film used for such applications include a fluorine resin film, an olefin resin film, and a polyethylene terephthalate film (hereinafter abbreviated as PET film).
Those using a fluorine-based resin film as a base material are used for exterior materials that require weather resistance, such as cars, outer walls of houses, tents, and the like.
Also, those based on olefin-based resin films are mainly used for interiors of houses where vinyl chloride-based resins have been used, such as wallpaper, doors, and home appliances.
Furthermore, what used a PET film as the base material is used for, for example, window pasting, home appliance surface materials, labels, signs, and the like.
[0003]
[Problems to be solved by the invention]
In the above film, first, in the case of a fluorine-based resin film, although it is excellent in terms of contamination, weather resistance, and slipperiness, it is easily scratched and has limited applications, There was a limit in the use of tape material.
Moreover, when laminating | stacking with another film, there are few adhesives with a fluorine resin film and adhesiveness, and the kind of film to laminate | stack was limited. Only the difluoride resin film can be laminated by coextrusion with an acrylic resin, but there is a disadvantage that the processing lot becomes large and the cost becomes high.
Furthermore, in the case of other tetrafluoride resin films, the performance is superior to that of difluoride resin films, but there is a drawback that co-extrusion cannot be performed.
[0004]
Next, in the case of an olefin-based resin film, the easy adhesion treatment method is limited to corona discharge treatment. Currently, in the field used as a substitute for vinyl chloride resin, anchor treatment called a primer is performed immediately after corona discharge treatment, but due to the effects of corona discharge treatment and changes over time, there are variations in products. Due to the frequent occurrence of defects, there was a lot of confusion in the market. Such variations in quality are caused by differences in the components of the olefin resin film, but it has been extremely difficult to adapt the easy adhesion treatment conditions for each component.
[0005]
Furthermore, in the case of PET film, corona discharge treatment and primer treatment can be cited as easy-adhesive treatment methods, but corona discharge treatment has the disadvantage of being less effective than olefin resin films.
Further, regarding the method of performing the heat treatment by in-line treatment at the time of film production under the primer treatment conditions, there is a limit in the selection of the resin, and the selection of the adhesive and the coating agent is necessary.
Furthermore, when processing lots are large and the easy adhesion primer treatment is performed offline, the resin selection range is widened, but the resin with good adhesion to the PET film is limited. Processing was difficult. Thus, the present condition is that the film which eliminates said fault about various films has not been developed yet.
Therefore, the present invention solves the above-mentioned conventional problems, and significantly improves the adhesion between the resin-primed layer and the resin laminated in the subsequent process, and also hard coat processing and printing processing It is an object of the present invention to provide a method for producing a film excellent in surface processability that can be applied to the above.
[0006]
[Means for Solving the Problems]
As a result of intensive research to solve the above problems, the present inventor has provided a resin layer on the surface of the base film, and the surface has a large number of small holes having a specific range of diameters. By setting the ratio between the total area of the holes and the area of the entire surface to a specific condition, an excellent film manufacturing method capable of solving the problems has been found, and the present invention has been completed.
That is, the present invention is, on the surface of the substrate film having a thickness 12～500Myuemu, possess an adhesive and the substrate film, the average particle diameter of silica 30 wt% dispersion containing the 0.01~10μm A resin layer having a thickness of 0.1 to 10 μm is provided, the surface of the resin layer is processed by sandblasting, and then etched with a hydrofluoric acid solution, the total area of small holes is formed on the surface of the resin. Is a method for producing a film excellent in surface workability, in which a large number of small holes having a diameter of 0.01 to 30 μm are formed such that the diameter is in the range of 30 to 90% of the total area .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the film excellent in surface workability of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a partial cross-sectional explanatory view showing an example of the film of the present invention. As shown in this figure, the film 1 of the present invention is mainly composed of a base film 2 and a resin layer 3 provided on the surface. A large number of small holes 5 are formed on the surface of the resin layer 3 in order to improve adhesion to the hard coat layer 4.
Examples of the film used as the substrate used in the present invention include a fluorine-based resin film, an olefin-based resin film, and a PET film, and can be appropriately selected depending on the application.
[0008]
Examples of the fluororesin film include tetrafluoroethylene-ethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and tetrafluoroethylene-perfluoro. Examples include alkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), polyvinyl fluoride (PVF), chlorofluoroethylene-ethylene copolymer (ECTFE), polychlorotrifluoroethylene (PCTFE), and the like.
[0009]
In addition, as the olefin resin film, homopolymers of olefin monomers such as ethylene, propylene, butene, pentene, and copolymers of these olefin monomers and other unsaturated monomers are used. , Resin films each having a main component are used.
Examples of the homopolymer and copolymer include high-density polyethylene, low-density polyethylene, crystalline ethylene-propylene block copolymer, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, and ethylene-methyl. Methacrylate copolymer, ethylene-ethyl acrylate copolymer, crystalline polypropylene, random polypropylene, block polypropylene, propylene-vinyl acetate copolymer, propylene-methyl acrylate copolymer, propylene-ethyl acrylate copolymer, and the like. These are used alone or in combination of two or more.
Furthermore, what is necessary is just the normally used PET film.
These exemplified substrate films vary in thickness depending on the purpose of use, but have a thickness in the range of 12 to 500 μm. If the thickness is less than 12 μm, the strength is weak when processing, and it is not preferable because it breaks or breaks. On the other hand, if it exceeds 500 μm, the cost increases and the effect of increasing the thickness is normal. It is not preferable because it does not change much.
[0010]
As the resin layer provided on the surface of the base film, a resin material having excellent adhesiveness with the base film is used.
As such a resin material, first, in the case of a fluorine-based resin film, for example, a fluorine resin, a urethane resin, and the like can be mentioned. In particular, in the case of a urethane resin, a silane coupling agent is added to 30 to 40% by weight. The resin material used is used.
Since these materials add and disperse a lot of inorganic fillers, a blend resin of a urethane resin and a silane coupling agent is preferable because of better adhesion.
In the case of an olefin-based resin film, a polyester-based urethane resin having a high degree of polymerization may be mentioned. Among them, a resin material obtained by adding 20 to 50% by weight of a reactive urethane resin having a low degree of polymerization to this resin is preferable. Adopted.
Furthermore, in the case of a PET film, the same resin material as in the case of an olefin resin film can be used.
[0011]
In the resin material exemplified above, the inorganic filler is dispersed in the resin material constituting the resin layer, and then the surface is processed by a sand blast method, and then an etching process is performed to form a large number of small holes.
Silica is employed as the inorganic filler used in the present invention.
The inorganic filler is usually granular and has a circular cross section, but is not limited to this, and may be in a state of secondary aggregation.
The average particle size of the inorganic filler is preferably about the same as the thickness of the resin to be applied, but when transparency is not required, even if the particle size is smaller than the thickness of the applied resin, It can be large. As an average particle diameter of such an inorganic filler, it is the range of 0.01-10 micrometers.
In addition, as the component ratio of the inorganic filler increases with respect to the resin material, the cohesive force of the coating film is inferior, so the addition rate of the inorganic filler is limited. Depending on the type of inorganic filler, the type of resin, and the thickness of the coating film Although the respective limit values are different, the blending ratio is in the range of 1 to 30% by weight with respect to the resin.
[0012]
The thickness of the coating film constituting the resin layer is in the range of 0.1 to 10 μm, preferably in the range of 1 to 5 μm. If this thickness is less than 0.1 μm, the cohesive force in places other than where small holes are provided becomes fragile, and conversely, if the thickness exceeds 10 μm, the cohesive force of the film becomes stable, and more Even if it becomes, there is no marked improvement.
[0013]
In order to form the resin layer constituting the film of the present invention, a coating material in which an inorganic filler is dispersed may be applied to the surface of the base film. Such a coating method is usually performed by a coating machine and applied. A gravure or a Meyer bar method is used for the roll to perform.
In this way, the coating material may be applied directly to the surface of the base film, but after applying a coating material that does not disperse the inorganic filler to about 1 to 3 μm in advance on the base film, the coating layer is applied by applying the coating material. This is preferable because the cohesive force becomes larger and more stable.
[0014]
In the present invention, the surface of the resin layer formed by applying to the base film is in a state where the inorganic filler is covered with the resin, and the inorganic filler is not exposed.
Therefore, the process which removes the part of an inorganic filler by an etching process at a post process, and exposes an inorganic filler on the application | coating surface is required.
In the present invention, the sand blast method is adopted as the method. The sand blasting method is a method in which a minute sand is struck against the film surface to make the surface uneven while removing a slight surface layer on the film surface.
This method is suitable for the present invention, whereby the coating surface layer is uniformly and slightly removed, and the inorganic filler portion and the resin portion are exposed. The particle size and amount of sand used in the sandblasting method and the processing time are adjusted according to the coating thickness. When the thickness is small, the particle size of the sand is reduced, and the amount and processing time are adjusted to be small. If it is thick, the reverse adjustment is performed. However, the particle size of the sand is the same over a certain level, and the rest is adjusted only by the amount and time.
[0015]
Etching is performed on the portion of the inorganic filler exposed by the sandblasting method to form a large number of small holes on the surface of the resin layer. As the etching solution, since the filler is made of an inorganic material, a strong alkaline solution or a corrosive acid solution is used, but an acid solution having little influence on the coating resin is preferable. As the corrosive acid solution of the inorganic material, hydrofluoric acid is most corrosive and has good etching processability. There is no influence on the coating resin component, and the cohesive strength of the film having small pores after corrosion is not impaired. The concentration of this liquid is often used at 30 to 50%.
The etching use residue may be processed after neutralization with alkali, and there is no problem if the inorganic filler component is also subjected to sedimentation or adsorption treatment.
The large number of small holes formed by the etching treatment is more preferably in the range of 30 to 90% , particularly 50 to 70% of the total area of the small holes with respect to the entire surface area. If this ratio exceeds 90%, the resin portion becomes too small at the surface interface, and cohesive failure at that portion easily occurs. On the contrary, if this ratio is less than 30%, the cohesive strength of the resin part at the interface of the surface is satisfied, but when the surface treatment layer having poor adhesiveness is originally stacked, the contact area is small and the shape I cannot expect the throwing effect to do.
[0016]
A hard coat layer for surface processing is formed and used on the surface of the etched resin layer. Such a hard coat layer is made of a commonly used hard coat resin, for example, an acrylic UV hard coat, etc., and after applying this paint, it is cured by irradiation with UV. Surface processing can be performed.
[0017]
【Example】
By the method shown below, a resin layer was provided on the surface of the base film, a hard coat layer was further formed on the surface, and a peel test between the hard coat layer and the resin layer was performed.
[Production method]
1. As the base film, a polyolefin film having a thickness of 100 μm [Pyrene film, manufactured by Toyobo Co., Ltd., trade name] was used.
2. As a method for forming a resin layer on the surface of the base film, the resin component of the coating material to be applied was a blend of polyester urethane resin and isocyanate resin in a weight ratio of 7: 3. The paint was diluted with toluene at a ratio of 50% with respect to the resin.
3. Silica was dispersed in the resin as an inorganic filler to be added. The particle size and amount added were variously changed between the examples and comparative examples.
4). The application was performed with a gravure coater, and the thickness was changed between the example and the comparative example. After coating, the coated surface was dried with dry hot air to dry the diluted solvent and accelerate the curing of the coated resin.
5). The coated surface was sandblasted. The processing conditions were such that about 10% of the coated layer was removed.
6). Etching was performed on the surface that had been scraped off by sandblasting. As the etching conditions, a hydrofluoric acid solution having a concentration of 35% was used. The treatment conditions were a liquid temperature of 40 ° C., and the treatment was performed by changing the time depending on the film thickness and the amount of inorganic filler added.
7). An acrylic UV hard coat paint was applied to the etched polyolefin film having a large number of small holes and cured by UV irradiation.
8). Whether or not the UV cured film was adhered to the polyolefin film was evaluated by a peel test using an adhesive cello tape.
A peel test was performed on the various films produced by the above method, and the results are shown in Table 1.
[0018]
In addition, the evaluation method in a peeling test is as follows.
◎ ... Good without peeling.
X: Cohesive failure of the primer layer occurred.
XX: Peeling occurred between the primer layer and the UV hard coat.
[0019]
[Table 1]

[0020]
[Evaluation results]
In the present invention shown in Examples 1 to 3, good results were obtained without occurrence of peeling, whereas in the conventional examples shown in Comparative Examples 1 to 5, peeling and cohesive failure of the primer layer occurred, Satisfactory results were not obtained.
[0021]
【The invention's effect】
According to the present invention, the adhesion between the layer formed by priming the resin formed on the surface of the base film and the resin laminated in the subsequent steps can be remarkably improved. And a method for producing a film excellent in surface processability can be provided.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional explanatory view showing an example of a film of the present invention.
[Explanation of symbols]
1 Film 2 Base Film 3 Resin Layer 4 Hard Coat Layer 5 Small Hole

Claims (1)

On the surface of the substrate film having a thickness 12～500Myuemu, possess an adhesive and the substrate film, the average particle diameter comprising silica 30 wt% dispersion of 0.01~10μm thickness 0 A resin layer having a thickness of 1 to 10 μm is provided, the surface of the resin layer is processed by sandblasting, and then the etching is performed with a hydrofluoric acid solution. A method for producing a film excellent in surface processability, wherein a large number of small holes having a diameter of 0.01 to 30 μm are formed so as to be in a range of 90% .

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