JP6318561B2 - Stretchable transfer film - Google Patents

Description

The present invention is, with respect to the transfer substrate surface having a three-dimensional shape, functionality and about the transfer fill arm for imparting design properties. More specifically, using vacuum pressure forming, with respect to the transfer substrate surface, directed to suitably transfer fill arm used to impart functionality and design.

Conventionally, as an alternative to coating, a hard coat transfer film in which a transfer layer comprising a protective layer (hard coat layer) and an adhesive layer, or a protective layer, a decorative layer and an adhesive layer is used on a base film, Transfer-type decoration and function-providing technologies have been proposed. For example, a method of transferring a transfer layer onto a resin molded product at the same time as injection molding, a method of transferring a transfer layer to a transfer target with the heat pressure of a hot roll, a vacuum and pressure air, and a heater to the transfer target. There are various methods such as a transfer method.
Among these, when using vacuum, compressed air, and a heater, transfer is performed on the transfer target as follows. First, on the surface of a three-dimensional molded product that is a substrate to be transferred, a transfer film having a transfer layer and having thermoformability is held in a heat-softened state. Next, the air between the substrate to be transferred and the heat-softened transfer film is sucked in vacuum, and compressed air is introduced to the back side of the transfer film as necessary. By doing so, a pressure difference is generated in the air on both surfaces of the transfer film, and the transfer film is molded and closely adhered along the three-dimensional solid shape of the surface of the transfer substrate. From the adhered transfer film, the transfer layer is uniformly transferred to the surface of the substrate to be transferred, and the transfer is completed by peeling the substrate film from the transfer layer.

  The transfer method using vacuum / pressure forming is not limited to the material of the substrate to be transferred, and can also be applied to the substrate having a relatively complicated shape. It is often used for decoration.

  In the transfer film used in such a transfer method by vacuum / pressure forming, the base film needs to have stretchability to follow the shape of the base material to be transferred. In addition, the resin used for the base film is a thermoplastic resin, and the softening temperature is required to be within the heating temperature range during molding. Therefore, for the base film, polyvinyl chloride resin (for example, see Patent Document 1), amorphous polyethylene terephthalate resin (for example, see Patent Document 2), amorphous polyethylene terephthalate resin (for example, see Patent Document 3), etc. The film which consists of is widely used.

Japanese Patent No. 3175057 Japanese Patent No. 4402227 JP 2000-296591 A

  However, while the thermoplastic resin is excellent in thermoformability, it is easily deformed by heat, and there is a problem that the drying temperature during printing / coating on the film is limited. In addition, depending on the material of the base film, there are some which are inferior in solvent resistance, and there is a disadvantage that usable resin materials are limited.

The present invention has been made in view of such circumstances, and its purpose is to prevent deformation due to heating and drying during printing and coating without impairing the thermoformability of the thermoplastic resin, and to resist solvent. and to provide a stretched transcription fill beam imparted with sex.

  In order to solve the above problems, the basic structure of the transfer film of the present invention is that a shape stabilizing layer is provided on both sides of the base film, and at least the transfer layer is laminated on one shape stabilizing layer. And

That is, the invention according to claim 1 of the present invention is a transfer film comprising a base film and a transfer layer, wherein a shape stable layer is provided on both sides of the base film, and the shape stable layer is On one of the surfaces, a transfer layer in which at least a surface protective layer and an adhesive layer are laminated in this order is provided , and the shape stabilizing layer contains at least an acrylic urethane resin obtained by crosslinking an acrylic polyol with an isocyanate compound. Or a resin obtained by crosslinking and curing an active energy ray-curable acrylic resin composition, when the thickness of the shape stabilizing layer is a and the thickness of the base film is ρ , the thickness ρ of the base film is in the range of 25μm or 250μm or less, and, transfer Fi characterized that you satisfy the relation 0.004ρ ≦ a ≦ 0.2ρ It is a non.
Also, the invention according to claim 2 of the present invention, the elongation at break of the form-stable layer, characterized in that at thermoforming temperatures less than 80% to 400% transfer film according to claim 1 It is.
The invention according to claim 3 of the present invention is the transfer film according to claim 1 or 2 , wherein the softening temperature T of the shape stabilizing layer is 80 ° C <T <150 ° C.
The invention according to claim 4 of the present invention is the transfer film according to any one of claims 1 to 3 , wherein the base film is made of a resin mainly composed of a polyvinyl chloride resin .

According to the present invention, it has a thermal deformation resistance and solvent resistance, it is possible to provide stretchability transfer fill beam excellent in thermoformability.

It is a schematic sectional drawing which shows an example of the transfer film in this invention. It is a schematic sectional drawing which shows the other example of the transfer film in this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, the transfer film 6 according to the present invention has the shape stabilizing layer 2 laminated on both surfaces of the base film 1, and at least the surface protective layer 4 is bonded on one surface of the shape stabilizing layer. The basic configuration is that a transfer layer 3 in which the layers 5 are laminated in this order is provided.
Although not clearly shown in the drawings, a decorative layer may be provided between the surface protective layer 4 and the adhesive layer 5. The decorative layer is a layer for imparting an arbitrary pattern, color, and appearance effect to the molded product. With such a configuration, the design of the molded product can be dramatically improved.
As the decorative layer, a printed pattern layer, a metallic gloss layer such as sputtering or vapor deposition, or a metallic print layer can be used, and can be provided according to a required design.

The shape stable layer 2 is a layer for imparting heat deformation resistance and solvent resistance to the base film 1. In general, a base film used for vacuum / pressure forming is excellent in thermoformability, but on the other hand, it is easily deformed by being heated during drying during printing / coating. Therefore, the drying temperature cannot be set higher than the heat deformation temperature of the base film. As a result, there is a drawback that the amount of solvent remaining in the obtained transfer film tends to increase. The solvent remaining on the transfer film may be vaporized by heating during vacuum / pressure forming to cause appearance defects such as swelling and whitening. On the other hand, in order to reduce the residual solvent by drying at a low temperature so that the base film is not thermally deformed, it is necessary to lengthen the drying time, leading to high costs such as a long process time.
In addition, some base films have poor solvent resistance depending on the materials used, and there is a drawback that the types of solvents that can be used during printing and coating are limited.
However, by providing the shape stabilizing layer 2 excellent in heat deformation resistance and solvent resistance on both surfaces of the base film 1, the above-described inconveniences in the process can be solved.

  The shape stabilizing layer 2 needs to be provided on both surfaces of the base film 1. When the shape stable layer 2 is formed only on one surface of the base film 1, only the surface of the surface of the base film 1 on which the shape stable layer 2 is not formed has low heat resistance and heat deformation is not caused. Since it becomes large, curvature and a deformation | transformation will occur easily in the base film 1 whole.

  The thickness a of the shape stabilizing layer 2 desirably satisfies the relationship of 0.004ρ ≦ a ≦ 0.2ρ when the thickness of the base film 1 is ρ. If the thickness of the shape stabilizing layer 2 is too thick than the above-described amount, the influence of the heat shrinkage or curing shrinkage of the shape stabilizing layer 2 itself increases during the formation of the shape stabilizing layer 2 and the base film 1 is likely to be deformed. Become. On the other hand, if the thickness of the shape stabilizing layer 2 is too thin than the above-mentioned amount, the imparting of heat deformation resistance and solvent resistance becomes insufficient.

  The elongation at break at the thermoforming temperature of the shape stable layer 2 is preferably 80% or more and less than 400%. When the elongation at break is smaller than the above-mentioned value, the shape followability to the transferred material becomes poor during thermoforming, and the shape of the transferred material that can be transferred is greatly limited. On the other hand, if the elongation at break is too larger than the above-mentioned value, it tends to be deformed by heating and drying during printing and coating, and does not function as a shape-stable layer.

  The softening temperature T of the shape stabilizing layer 2 is preferably 80 ° C. <T <150 ° C. If the softening temperature is too low, it will be easily deformed by heating and drying during printing and coating, and will not function as a shape stabilizing layer. On the other hand, if the softening temperature is too high, it is necessary to set the heating temperature during vacuum / pressure forming higher than usual, which is disadvantageous in terms of thermal energy efficiency and process time.

  The transfer film 6 according to the present invention may be provided with a release layer 7 between the shape stabilizing layer 2 and the surface protective layer 4 as shown in FIG. However, from the viewpoint of reducing the number of processes and materials, and reducing the cost, it is more desirable to give the shape stabilizing layer 2 the function of a release layer.

  Next, each material which comprises the transfer film which concerns on this invention, and the manufacturing method of a transfer film are demonstrated.

(Base film)
As the material for the base film 1, one having a softening temperature T of 80 ° C. <T <150 ° C. is preferably used, and a resin generally used for vacuum forming and / or pressure forming can be used. For example, polyvinyl chloride resin, non-crystalline polyethylene terephthalate resin, amorphous polyethylene terephthalate resin, polyprolene resin, acrylic resin, etc. are mentioned. It is more preferable because it is inexpensive.
The thickness of the base film 1 is preferably about 25 μm or more and 250 μm or less, and more preferably about 38 μm or more and 150 μm or less. If the thickness of the base film 1 is less than the above range, it is easy to break during vacuum / pressure forming. On the other hand, if the thickness of the base film 1 is too thick than the above range, the moldability is inferior and the material cost is low. Since it becomes expensive, it is not preferable.

(Shape stable layer)
The shape stable layer 2 needs to have at least heat resistance, solvent resistance, top coatability and stretchability, and needs to be formed under coating conditions in which the base film 1 is not thermally deformed. The following two methods can be used as a forming method that satisfies these requirements.
First, as a first method, there is a method in which the shape stabilizing layer 2 is formed of a resin containing at least an acrylic urethane resin obtained by crosslinking an acrylic polyol with an isocyanate compound. In this case, the crosslinking reaction between the acrylic polyol and the isocyanate compound proceeds by aging in a low temperature range of about room temperature to about 50 ° C., and thus it is not necessary to expose to a high temperature. Accordingly, it is possible to suppress problems such as wrinkle generation, heat shrinkage, and crystallization of the base film assumed in the progress of the curing reaction at a high temperature.
Moreover, as a 2nd method, the active energy ray hardening-type resin is apply | coated to a base film, The method of forming the shape stable layer 2 by irradiating an ultraviolet-ray etc. and carrying out cross-linking hardening is mentioned. Here, as the active energy ray-curable resin composition, in particular, when a solvent-free type is used, the shape stable layer 2 can be easily formed not only on heat resistance but also on a substrate film having poor solvent resistance. Is possible.

(Surface protective layer)
The surface protective layer 4 is in a tack-free state (a state in which the stickiness is eliminated simply by evaporating the solvent component) in the transfer film before being used for transfer, and after being transferred to the transfer target, it is irradiated with active energy rays. It is preferable that it consists of resin which can be bridge | crosslinked by this. The reason for crosslinking by irradiating active energy rays after transfer is that if the transfer film provided with the surface protection layer 4 in a pre-crosslinked state is vacuum-compressed, the transfer film will follow the surface of the transfer object. This is because the surface protective layer 4 is liable to crack when it is stretched, causing a poor appearance. The resin constituting the surface protective layer 4 is not particularly specified as long as it satisfies the required physical properties such as weather resistance, abrasion resistance, scratch resistance, chemical resistance, and the like. It can be suitably selected from resins, acrylic resins, polyester resins and the like. There are mainly the following three methods for bringing the surface protective layer 4 into a tack-free state in the transfer film before being used for transfer. The first method is a method of using a polymer acrylate or methacrylate as the resin constituting the surface protective layer 4. In the second method, as the resin constituting the surface protective layer 4, in addition to the active energy ray-curable resin, a crosslinking reaction product such as isocyanate / polyol resin or epoxy resin / amines is contained and cured appropriately. This is a method of tack-free. The third method uses an active energy ray-curable resin as a resin constituting the surface protective layer 4 and irradiates an appropriate amount of active energy rays within a range that does not impair the shape followability to the transfer target. This is a method of making a linear curable resin into a semi-cured state.
Since the surface protective layer 4 obtained by using any of the above methods retains thermoplasticity, it can be transferred while following the surface shape of the transfer target. Then, the surface protective layer 4 is completely cross-linked and cured by irradiating active energy rays after the transfer. Thereby, the said surface protective layer 4 can make sufficient hardness (hard-coat property) and moldability compatible.
The thickness of the surface protective layer 4 is preferably about 3 to 20 μm.

(Adhesive layer)
The material of the adhesive layer 6 is not particularly limited as long as it has adhesiveness and / or tackiness, and includes what are called adhesives, adhesives, and hot melts.
For example, acrylic, epoxy, vinyl acetate, vinyl chloride, isocyanate, silicone, styrene-butadiene, vinyl chloride-vinyl acetate, ethylene-vinyl acetate, polyester, rubber chloride, chlorinated polypropylene Examples thereof include emulsion resins, organic solvent-type resins, water-soluble resins, etc., each of which uses a single resin such as a polyurethane resin or a polyurethane resin alone, or a mixture thereof.
Although there is no restriction | limiting in particular in the thickness of the contact bonding layer 6, Usually, it is about 0.5 micrometer-10 micrometers.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited only to a following example.

<Example 1>
A polyvinyl chloride resin film having a thickness of 50 μm was used as the base film 1. The thickness of the resin coating solution obtained by adding 10 parts by weight of an isocyanate compound and 1 part by weight of an acrylic silicone resin containing a hydroxyl group to 100 parts by weight of an acrylic polyol on both sides of the base film 1 after drying. Was applied by a micro gravure method so as to be 0.2 μm to form the shape stable layer 2.
Next, the following layers were sequentially laminated as the transfer layer 3 on one surface of the shape stabilizing layer 2. First, a surface-protecting layer 4 was formed by applying a tack-free UV curable resin by a reverse gravure coating method so that the thickness after drying was 10.0 μm.
Next, the acrylic resin adhesive layer 5 was laminated on the surface of the surface protective layer 4 by gravure printing so that the thickness after drying was 2.0 μm, thereby obtaining a transfer film 6 according to the present invention.
The transfer film 6 is heated so that the surface temperature of the transfer film 6 is 100 ° C. with respect to the surface of a polycarbonate ABS alloy molded article having a concave portion with a height difference of 5 mm and an opening of 50 mm square on the top. Then, the substrate film 1 and the shape stabilizing layer 2 of the transfer film 6 were peeled and removed after cooling, and a transfer molded product free from chipping or cracking in the transfer portion could be obtained.

<Example 2>
As the base film 1, an amorphous polyethylene terephthalate resin film having a thickness of 100 μm was used. A microgravure method in which a resin coating solution in which 5 parts by mass of a photopolymerization initiator is added to 100 parts by mass of an ultraviolet curable acrylic resin on both surfaces of the base film 1 is 20 μm after curing. It was applied with. Thereafter, using a high-pressure mercury lamp 80 W / cm, the shape stabilizing layer 2 was formed by irradiating with ultraviolet rays so that the accumulated light amount was 400 mJ / cm ² to be crosslinked and cured.
Next, the following layers were sequentially laminated as the transfer layer 3 on one surface of the shape stabilizing layer 2. First, a surface-protecting layer 4 was formed by applying a tack-free UV curable resin by a reverse gravure coating method so that the thickness after drying was 10.0 μm.
Next, on the surface of the surface protective layer 4, by gravure printing, a pattern layer by printing ink is formed, and further, an acrylic resin adhesive layer 5 is laminated so that the thickness after drying becomes 2.0 μm, A transfer film 6 according to the present invention was obtained.
When the transfer film 6 was used for transfer under the same conditions as in Example 1, it was possible to obtain a transfer molded product having no chipping or cracking in the transfer portion including the pattern layer.

<Comparative Example 1>
A polyvinyl chloride resin film having a thickness of 50 μm was used as the base film 1. When one surface of the base film 1 was coated with a tack-free UV curable resin as a surface protective layer 4 by a reverse gravure coating method so that the thickness after drying was 10.0 μm, The surface of the base film was eroded by normal butyl acetate, which was a diluting solvent at the time, and the smoothness of the base film surface was lowered, and the transfer film 6 could not be obtained.

<Comparative example 2>
A polyvinyl chloride resin film having a thickness of 50 μm was used as the base film 1. The thickness of the resin coating solution obtained by adding 10 parts by weight of an isocyanate compound and 1 part by weight of an acrylic silicone resin containing a hydroxyl group to 100 parts by weight of an acrylic polyol on both sides of the base film 1 after drying. Was applied by a microgravure method so that the thickness became 0.1 μm, and the shape stable layer 2 was formed.
Next, a tack-free UV curable resin is applied as a surface protective layer 4 on one surface of the shape stabilizing layer 2 by a reverse gravure coating method so that the thickness after drying becomes 10.0 μm. As a result, the substrate film 1 was greatly wrinkled due to the influence of heat applied to dry the coating solution, and the transfer film 6 could not be obtained.

<Comparative Example 3>
As the base film 1, an amorphous polyethylene terephthalate resin film having a thickness of 100 μm was used. A microgravure method in which a resin coating liquid in which 5 parts by mass of a photopolymerization initiator is added to 100 parts by mass of an ultraviolet curable acrylic resin on both surfaces of the base film 1 is 30 μm in thickness after curing. It was applied with. Then, using a high pressure mercury lamp 80W / cm, integrated light quantity is crosslinked and cured by irradiation with ultraviolet rays to be 400 mJ / cm ^2, it was formed a shape-stable layer 2, the shape stability layer 2 of curing shrinkage by group Large waviness-like deformation occurred in the entire material film 1, and the transfer film 6 could not be obtained.

DESCRIPTION OF SYMBOLS 1 ... Base film 2 ... Shape stabilization layer 3 ... Transfer layer 4 ... Surface protective layer 5 ... Adhesive layer 6 ... Transfer film 7 ... Release layer

Claims (4)

In a transfer film comprising a base film and a transfer layer, a shape stabilizing layer is provided on both surfaces of the base film, and at least a surface protective layer is provided on one surface of the shape stabilizing layer. A transfer layer in which adhesive layers are laminated in this order is provided ,
The shape stabilizing layer includes at least one of a resin containing an acrylic urethane resin obtained by crosslinking an acrylic polyol with an isocyanate compound, or a resin obtained by crosslinking and curing an active energy ray-curable acrylic resin composition,
When the thickness of the shape stabilizing layer is a and the thickness of the base film is ρ, the thickness ρ of the base film is in the range of 25 μm or more and 250 μm or less, and 0.004ρ ≦ a transfer film characterized that you satisfy the relationship ≦ 0.2ρ. The transfer film according to claim 1, wherein the elongation at break of the shape-stable layer is 80% or more and less than 400% at a thermoforming temperature. Wherein the softening temperature T of the form-stable layer is 80 ℃ <T <150 ℃, transfer film according to claim 1 or 2. It said substrate film, characterized by comprising a resin as a main component a polyvinyl chloride resin, a transfer film according to claims 1 to 3.

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