JP6749771B2 - Substrate film for transfer decoration - Google Patents

Description

The present invention relates to a base film for transfer decoration.

A design is imparted by decorating the base material of molded articles such as automobile accessories and miscellaneous goods with various characters and patterns. For a base material of a molded product having a complicated surface shape such as a three-dimensional solid shape, the decorative layer is transferred to the base material of the molded product by a vacuum molding method, an injection molding method, or the like for decoration. In the present specification, the decorative film having the transferred decorative layer is referred to as "transfer decorative film".

The transfer decorative film has, for example, a structure in which a clear layer (protective layer), a coloring layer, and an adhesive layer are provided on a base film, and the transparent film is provided between the base film and the clear layer. A film or the like provided with a mold layer is known (for example, see Patent Document 1).

The vacuum molding method, which is a method of transferring the decorative layer to the base material of the molded product, includes the steps of (i) heating and softening the transferred decorative film in a vacuum chamber to spread it, and (ii) the base material of the molded product. Side (the side to which the decorative layer of the transfer decorative film is transferred, the side to which the transfer layer is attached) is depressurized, the step of pressurizing the space on the opposite side if necessary, (iii) a molded product of the transfer decorative film The step of molding (attaching) along the three-dimensional three-dimensional shape of the substrate, and (iv) the step of peeling off the base film leaving the decorative layer on the substrate of the molded product.

BACKGROUND ART Conventionally, a film using polyester such as polyethylene terephthalate (PET) or an acrylic resin has been used as a substrate (base material) of a transfer decorative film used in a vacuum forming method (Patent Document 1). However, when a film such as PET or acrylic resin is used as the base of the decorative layer, when the transfer decorative film is transferred to the base material of the molded product by the vacuum molding method, the three-dimensional shape of the base material of the molded product is However, there is a problem that the followability of the transfer decorative film is insufficient.

Further, in the vacuum forming method, a process of applying heat to spread the transfer decorative film is performed. In this heat treatment, since the transfer decorative film is subjected to a high temperature of about 170° C. and then molded, it is necessary to cool it once to room temperature when the product in the next step is decorated. Then, there is a problem that this cooling process takes time.

Therefore, there is a demand for a base film that can be vacuum formed even at a relatively low temperature. Examples of such a base film include the use of a polypropylene-based thermoplastic resin. In this case, the followability (vacuum formability) of the transfer decorative film with respect to the molded product is good, but when the transfer decorative film is heated, excessive softening causes the film to sag more than necessary, so-called drawdown occurs. was there.

JP 2011-88420 JP

INDUSTRIAL APPLICABILITY The present invention is applied to a technique for producing a decorative molded product by a vacuum molding method, in which the followability (vacuum moldability) of the transfer decorative film to the molded product is good even under relatively low temperature conditions. The main purpose is to provide a possible substrate film.

Further, the main object of the present invention is to provide a substrate film that can be applied to transfer decorating and that can prevent so-called drawdown in which the film does not sag more than necessary even when the film is heated and softened. And

The present inventor, as a result of intensive research to solve the above problems, found that the above object can be achieved by using an ionomer resin as a resin component used in a layer constituting a substrate film for transfer decoration. The present invention has been completed.

That is, the present invention provides the following substrate film for transfer decoration.

Item 1.
A base film for transfer decoration, which contains 5 to 60% by mass of an ionomer resin based on the total mass of the film.

Item 2.
Item 2. The transfer decorating base film according to Item 1, further comprising 40 to 95% by mass of a thermoplastic resin based on the total mass of the film.

When the base film for transfer decoration film of the present invention is used, by incorporating a specific amount of ionomer resin into the base film, the transfer decorative film can follow the molded product even under relatively low temperature conditions (vacuum molding). Sex) is good.

Further, when the transfer decorating film of the present invention is used, when the transfer decorating film is heated and softened, the film does not sag more than necessary and drawdown can be suppressed.

Therefore, the base film of the present invention can be applied for transfer decoration.

It is a figure which shows the outline of the measuring method of a drawdown amount.

The substrate film for transfer decoration of the present invention is characterized by having a specific content ratio of an ionomer resin.

The substrate film for transfer decoration of the present invention is a technique for producing a decorative molded product by a vacuum molding method (three-dimensional vacuum molding method) on the basis of a molded product having a complicated surface shape such as a three-dimensional solid shape. In the above, it is a base film which is preferably used for a transfer decorative film.

Hereinafter, each layer constituting the substrate film for transfer decoration will be described.

(1) Base Film for Transfer Decoration The base film for transfer decoration of the present invention contains an ionomer resin. Examples of the ionomer resin include an olefin-based ionomer resin, a urethane-based ionomer resin, and a fluorine-based ionomer resin. Among these, an olefin-based ionomer resin can be preferably used as a film or sheet molded body.

Ionomer Resin The olefinic ionomer resin is a copolymer having an olefin and an unsaturated carboxylic acid as constitutional units. Examples of the olefin include ethylene and propylene, and as the unsaturated carboxylic acid, (meth)acrylic acid, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, (meth)acrylic Methacrylic acid alkyl esters such as octyl acid can be preferably used.

The olefin-based ionomer resin has ethylene and a binary copolymer having the (meth)acrylic acid as a constitutional unit, or ethylene, the (meth)acrylic acid and the (meth)acrylic acid alkyl ester as a constitutional unit. Examples include terpolymers. As the ionomer resin, a binary copolymer type ionomer resin or a ternary copolymer type ionomer resin in which at least a part of the carboxylic acid is neutralized with a metal ion can be preferably used.

Examples of the metal ions used here include divalent metal ions and trivalent metal ions. Examples of the divalent metal ion include Mg ²⁺ , Ca ²⁺ , Ba ²⁺ , Ni ²⁺ , Zn ²⁺ , Fe ²⁺ , Co ²⁺ , Sn ²⁺ , Pb ²⁺ and Mn ^2+. As the trivalent metal ion, Al ³⁺ , Fe ³⁺ , Cr ^{3+ and the} like can be mentioned. Among them, Zn ²⁺ is preferably used because it has little bleed-out and the characteristics of the molding containing the copolymer are stable.

The olefinic ionomer resin, in particular, the preferred proportion of each structural unit in the terpolymer ionomer resin, ethylene unit 50 to 90 wt%, (meth) acrylic acid unit 5 to 20 wt%, (meth) The alkyl acrylate unit is 5 to 30% by weight.

The density of the ionomer resin, preferably about 900~980kg / m ^3, about 940~960kg / m ³ and more preferably. By setting the density of the ionomer resin to about 900 kg/m ³ or more, it is possible to suppress the thermal deformation during the drying process when processing the base film into the decorative film and to suppress the drawdown. ..

In the present invention, as the ionomer resin, one kind or a plurality of kinds of copolymers having different kinds and contents of metal ions and different numbers of carboxyl groups may be appropriately mixed.

The ionomer resin in the present invention is not limited to the examples.

Other thermoplastic resin Ionomer resin can be used as a mixture with other thermoplastic resin. In this case, it is preferable as the transfer decorating base film from the viewpoint of suppressing thermal deformation during the drying step when processing the base film into the decorating film.

Examples of the thermoplastic resin include a propylene homopolymer, a propylene/ethylene random copolymer, a propylene/α-olefin random copolymer, and a propylene block copolymer. These thermoplastic resins may be used alone or in combination of two or more.

Specific examples of the α-olefin include 1-butene, 2-methyl-1-propene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 2-ethyl-1-butene, 2 ,3-Dimethyl-1-butene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3,3-dimethyl-1-butene, 1-heptene, methyl-1 -Hexene, dimethyl-1-pentene, ethyl-1-pentene, trimethyl-1-butene, methylethyl-1-butene, 1-octene, methyl-1-pentene, ethyl-1-hexene, dimethyl-1-hexene, Propyl-1-heptene, methylethyl-1-heptene, trimethyl-1-pentene, propyl-1-pentene, diethyl-1-butene, 1-nonene, 1-decene, 1-undecene, 1-dodecene and the like. ..

Resin composition of base film for transfer decoration The base film for transfer decoration contains 5 to 60% by mass of an ionomer resin. Here, the content ratio of the ionomer resin is a ratio with respect to the total mass of the transfer decorating base film.

The transfer decorating base film may have a single-layer structure, or may have a laminated structure of a layer containing an ionomer resin and a layer containing another thermoplastic resin, and between the layers having different ionomer resin contents. It may have a laminated structure.

As the content ratio of the ionomer resin in the transfer decorating base film, with respect to the total mass of the transfer decorating base film, preferably 5 mass% or more, more preferably 7 mass% or more, further 10 mass% or more. preferable. If the content ratio of the ionomer resin is less than 5% by mass, the base film tends to sag due to heating during vacuum forming, so-called drawdown tends to occur.

Further, the content ratio of the ionomer resin is preferably 60% by mass or less, and more preferably 50% by mass or less with respect to the total mass of the base film for transfer decoration. When the content ratio of the ionomer resin exceeds 60% by mass, thermal deformation tends to occur during the drying step when processing the base film into the decorative film.

The base film for transfer decoration preferably further contains 40 to 95% by mass of a thermoplastic resin. Here, the content ratio of the thermoplastic resin is a ratio with respect to the total mass of the transfer decorating base film.

The content ratio of the thermoplastic resin in the transfer decorating base film is preferably 40 mass% or more, and more preferably 50 mass% or more, with respect to the total mass of the transfer decorating base film. When the content ratio of the thermoplastic resin is less than 40% by mass, thermal deformation tends to occur during the drying step when processing the base film into the decorative film.

Further, the content ratio of the thermoplastic resin is preferably 95% by mass or less, more preferably 93% by mass or less, and further preferably 90% by mass or less with respect to the total mass of the base film for transfer decoration. When the content ratio of the thermoplastic resin exceeds 95% by mass, the base film tends to sag due to heating during vacuum forming, so-called drawdown tends to occur.

Layer structure of the transfer decorative base film, the transfer decorative base film, the thickness of the layer when a single layer, preferably about 80 ~ 300 (mu) m, more preferably about 90 ~ 290 (mu) m, more preferably about 100 ~ 280 (mu) m. preferable. By setting the thickness of the layer to 80 μm or more, an effect of suppressing thermal deformation during the drying step when processing the base film into the decorative film can be obtained. Further, by setting the thickness of the layer to 300 μm or less, it is possible to obtain an effect that the substrate film does not sag more than necessary during vacuum forming and drawdown can be suppressed.

In the base film for transfer decoration of the present invention, the film containing the above ionomer resin may be used as the A layer, and a surface layer (B layer) may be provided on the surface of the A layer. By providing the surface layer (B layer), effects such as imparting slipperiness, suppressing blocking, adhesiveness between the clear layer and the release layer, and imparting releasability can be obtained.

Examples of the resin component used in the surface layer (B layer) include thermoplastic resins, and include propylene homopolymers, propylene/ethylene random copolymers, propylene/α-olefin random copolymers, propylene block copolymers, Examples thereof include low density polyethylene, medium density polyethylene, ethylene-α-olefin copolymer, ethylene-vinyl ester copolymer, ethylene-unsaturated carboxylic acid ester copolymer, ethylene-unsaturated carboxylic acid copolymer and the like.

Further, in the substrate film for transfer decoration of the present invention, a back layer (C layer) may be further provided on the surface of the intermediate layer (A layer) which is not in contact with the surface layer (B layer). By providing the back surface layer (C layer), effects such as curling of the film, imparting slipperiness, and blocking of the transfer decorative film can be obtained.

As the resin component used for the back surface layer (C layer), the same resin components as those for the A layer can be mentioned. Further, it is preferable to use the same resin component as the B layer. In this case, the A layer becomes the intermediate layer.

When the transfer decorating base film has a multi-layer structure, the layer structure is a two-layer structure of a surface layer (B layer)/intermediate layer (A layer) or an intermediate layer (A layer)/back surface layer (C layer). , And a three-layer structure of a surface layer (B layer)/intermediate layer (A layer)/back surface layer (C layer). Among these, from the viewpoint of curling of the film, the B layer/A layer A three-layer structure of /C layer is preferable.

When the transfer decorating base film has a multilayer structure, the thickness of the entire film is preferably about 80 to 300 μm, more preferably about 90 to 290 μm. By setting the thickness of the film to 80 μm or more, it is possible to obtain the effect of suppressing thermal deformation during the drying step when processing the base film into the decorative film. Further, by setting the thickness of the film to 300 μm or less, it is possible to obtain an effect that the substrate film does not sag more than necessary during vacuum forming and drawdown can be suppressed.

When the transfer decorating base film has a multilayer structure, the thickness of the intermediate layer (A layer) is preferably about 10 to 200 μm, more preferably about 20 to 100 μm. The thickness of the surface layer (B layer) is preferably about 13 to 70 μm, more preferably about 25 to 65 μm. Furthermore, the thickness of the back surface layer (C layer) is preferably about 13 to 70 μm, more preferably about 25 to 65 μm.

Physical property value of transfer decorating base film The transfer decorating base film of the present invention has a TMA displacement amount measured by thermomechanical analysis (TMA) at 85° C. of preferably 10.0% or less, more preferably 9% or less. , 8% or less is more preferable. When the TMA displacement amount is 10.0% or less, the effect of suppressing thermal deformation during the drying step when processing the base film into the decorative film can be obtained. The above TMA displacement amount can be measured in accordance with JIS K7197.

Other Components of Transfer Decorative Base Film The additive of the base film for transfer decorative of the present invention can be added for the purpose of suppressing drawdown during extrusion molding, improving uneven thickness, and improving productivity.

As additives, HAO-LLDPE (Ube Maruzen Polyethylene's Umerit), PTFE (Mitsubishi Rayon's Metabrene), Kaneka's PP processability-improving material, crystal nucleating agent, eye drool inhibitor, antioxidant Etc. can be used. The amount of the additive added is not particularly limited, but from the viewpoint of physical properties and handling, it is preferably 20% by mass or less based on the total mass of the transfer decorating base film.

(2) Method for producing base film for transfer decoration The base film for transfer decoration of the present invention can be produced by extrusion molding a resin component containing an ionomer resin.

Specifically, in the case of a single-layer structure, the resin composition for layer A is supplied to an extruder adjusted to a barrel temperature of 130 to 260°C and extruded in a film form from a T die at 180 to 260°C, It can be produced by cooling and solidifying with a chill roll at ˜70° C., and taking it out substantially without stretching.

In the case of a multilayer structure, the resin composition for the surface layer (B layer), the intermediate layer (A layer), and the resin composition for the back surface layer (C layer) are added at barrel temperatures of 180 to 240, respectively. It can be produced by supplying the composition to an extruder for each layer adjusted to ℃, extruding it into a film form from a multi-layer T die at 180 to 260 ℃, cooling and solidifying with a cooling roll at 30 to 70 ℃, and taking it out substantially without stretching.

The transfer decorating film is manufactured through a step of laminating a clear layer, a coloring layer, an adhesive layer and the like on the transfer decorating base film of the present invention.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

<Resin component>
The resin components used are shown below.

PP-1: PC630A made by Sun Allomer
Ionomer 1: Mitsui DuPont Polychemical Co., Ltd. Hi-Milan 1855 (ionomer resin, density: 960 kg/m ³ , metal ion: Zn ²⁺ ).
Ionomer 2: Himilan 1652 manufactured by Mitsui DuPont Polychemicals (ionomer resin, density: 940 kg/m ³ , metal ion: Zn ²⁺ ).
PET1: Soft Shine manufactured by Toyobo Co., Ltd. Acrylic 1: Acrylene manufactured by Mitsubishi Rayon Co., Ltd.
TPO-1: Prime Polymer's prime TPO E-2900
<Examples 1 to 6 and Comparative Examples 1 to 6 (single layer)>
The resin component and its content ratio shown in Table 1 and Table 2, so that the resin component is supplied to a screw type extruder adjusted to 130 ~ 260 ℃, then extruded into a film from a T-die at 180 ~ 260 ℃. did. Then, this was cooled while passing through a cooling roll of 30 to 70° C. and wound in a substantially unstretched state to prepare a substrate film for transfer decoration.

The following physical properties of each of the obtained base films for transfer decoration were measured and evaluated.

<Elongation at break (%)>
A tensile tester (Autograph AG-X500N manufactured by Shimadzu Corporation) was set at 90°C. A sample of the base film for transfer decoration was cut into a width of 10 mm, a length of 50 mm, and a distance between marked lines of 40 mm, and a breaking elongation was measured when a tensile test was performed at a speed of 200 mm/min.

In the table, MD represents the breaking strength of the resin in the flow direction when the transfer decorating base film was manufactured, and TD represents the breaking strength of the resin in the width direction when the transfer decorating base film was manufactured.

This is a test for confirming the conformability of the base film for transfer decoration during vacuum forming to the formed product. 90° C. in the table is a heating temperature at the time of vacuum forming, and if it has a breaking elongation of 600% or more at that temperature, it is an excellent substrate film for transfer decoration in the vacuum forming method.

The fact that the heating temperature during vacuum forming can be lowered to 90°C means vacuum forming at a low temperature. Therefore, if the base film for transfer decoration has a good breaking elongation at that temperature, it can be said that the followability (concavo-convex followability) with respect to the molded product is good by the vacuum forming method under low temperature conditions. The decorative layer can be attached to the molded product by three-dimensional vacuum molding under low temperature conditions, and the production efficiency of the decorative molded product can be increased.

<TMA displacement>
It was measured under the following conditions in accordance with JIS K7197. If the TMA displacement is small, it means that the thermal deformation during the drying step when processing the base film into the decorative film is small.

The evaluation criteria for TMA displacement are as follows.

○: When the TMA displacement amount is 10% or less ×: When the TMA displacement amount exceeds 10%

[Measurement condition]
Equipment: TA Instruments TMA Q400
Tension mode Sample: Strip length 24mm, width 5mm strip load: 0.5N
Temperature rise: 10℃/min
Measure the displacement at 85℃

<Drawdown amount>
A substrate film for transfer decoration was set in an opening of 100 mm×100 mm, and heated by an IR heater so that the temperature of the film became 130° C. After heating for 90 seconds, the self-weight sag distance of the film was measured.

The evaluation criteria for the drawdown amount are as follows.

○: When the drawdown amount is 14 mm or less ×: When the drawdown amount exceeds 14 mm

FIG. 1 shows the method for measuring the drawdown amount.

The evaluation results are shown in Tables 1 and 2.

<Examples 7 to 16 and Comparative Examples 7 to 10 (multilayer structure including front surface layer/intermediate layer/back surface layer)>
The resin components and the content ratios of the respective layers shown in Tables 3 and 4 were supplied to each screw type extruder, and then extruded in a film form from a multilayer T die at 180 to 260°C. Then, this was cooled while passing through a cooling roll of 30 to 70° C. and wound in a substantially unstretched state to prepare a substrate film for transfer decoration.

With respect to each of the obtained transfer decorative substrate films, the above physical properties were measured and evaluated.

The evaluation results are shown in Tables 3 and 4.

Claims (3)

A base film for transfer decoration, comprising:
Based on the total mass of the film, containing 5 to 60 mass% ionomer resin , and 40 to 95 mass% thermoplastic resin,
The ionomer resin is an olefinic ionomer resin,
The thermoplastic resin is at least one thermoplastic resin selected from the group consisting of propylene homopolymer, propylene/ethylene random copolymer, propylene/α-olefin random copolymer, and propylene block copolymer. is there,
Substrate film for transfer decoration. The transfer decorating base film according to claim 1, wherein the olefin-based ionomer resin is a copolymer having an olefin and an unsaturated carboxylic acid as constitutional units . The olefin is selected from ethylene and propylene, and the unsaturated carboxylic acid is (meth)acrylic acid, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, And the base film for transfer decoration according to claim 2, which is an methacrylic acid alkyl ester selected from octyl (meth)acrylate.