JP7163997B2 - Method for manufacturing decorative molding - Google Patents

Description

TECHNICAL FIELD The present invention relates to a decorative film to be adhered onto a resin molded article by thermoforming, and a method for producing a decorated molded article using the decorative film. More specifically, it is a resin that is excellent in scratch resistance, weather resistance, and design, can exhibit sufficient adhesive strength to resin moldings, and has less grain return after thermoforming and less damage to the film during molding. The present invention relates to a decorative film to be adhered onto a molded article by thermoforming, and a method for producing a decorated molded article using the decorative film.

In recent years, demand for decoration techniques to replace painting has increased due to demands for reducing VOCs (volatile organic compounds), etc., and various decoration techniques have been proposed.

Among them, a technique has been proposed for forming a decorative molded article in which a decorative film and a molded body are integrated by applying a decorative film instead of a coating film to a molded body by vacuum pressure forming or vacuum forming (for example, Patent Document 1 ), which has received particular attention in recent years.

Decoration molding by vacuum pressure molding and vacuum molding has a greater degree of freedom in shape than other decoration molding represented by insert molding. In addition, since it can be thermoformed at a relatively low temperature and low pressure, it is possible to reproduce the texture on the surface of the decorative molded product by adding texture to the surface of the decorative film. It has the advantage of being superior to

Acrylic, which is a thermoplastic resin and easy to thermoform, has excellent properties such as transparency, scratch resistance, weather resistance, and ease of printing in such decorative molding by vacuum pressure molding and vacuum molding. Films made of system resins are widely used as decorative films. However, since the film made of acrylic resin softens in a relatively short time when heated, it is not possible to give a heating time long enough to allow the film to be attached to the object to be decorated in three-dimensional decorative thermoforming. There was a problem that the adhesive strength between the material and the object to be decorated was inferior. To address this problem, the use of layers such as acrylic adhesives, urethane adhesives, and tackifiers has been proposed as a layer for improving adhesive strength, but these layers are represented by polypropylene resins. However, there is a problem that sufficient adhesive strength cannot be obtained for non-polar resins.

To solve this problem, a decorative film including an adhesive layer containing a polypropylene resin is applied to a substrate (molded body) made of a polypropylene resin, so that the decorative film and the molded body are heat-sealed. has been proposed (see Patent Documents 2 and 3, for example). The inventions disclosed in Patent Documents 2 and 3 use a polypropylene-based resin as the adhesive layer of the decorative film. It is necessary to provide a layer of resin, polyurethane resin, polycarbonate or the like. By combining different kinds of raw materials in this way, thermoformability such as drawdown property is expressed, and it is possible to ensure thermoformability in a decorative film made of polypropylene-based resin that does not contain these different kinds of raw materials. The surface of the molded product to which this was adhered was likely to have holes, wrinkles, and entrainment of air. In particular, when polyurethane resin is included as a different raw material, polyurethane resin, which is a thermosetting resin, does not melt when heated, so it is easy to maintain the shape of the film and greatly improves thermoformability, but there is a problem that recyclability is extremely low. rice field.
In addition, the decorative thermoforming by vacuum pressure forming and vacuum forming has the advantage that a molded product having a high degree of integration between the base formed by the process such as injection molding and the decorative film can be obtained. There is a problem that scratches on the surface of the decorative molded product tend to cause poor appearance due to scratches on the surface of the base.

In addition, the decorative thermoforming by vacuum pressure forming and vacuum forming has the advantage that a molded product having a high degree of integration between the base formed by the process such as injection molding and the decorative film can be obtained. There is a problem that scratches on the surface of the decorative molded product tend to cause poor appearance due to scratches on the surface of the base.

JP-A-2002-67137 JP 2013-14027 A JP 2014-124940 A

Conventional techniques have not yet succeeded in developing a decorative film containing an acrylic resin that exhibits good adhesion to a substrate made of a polypropylene resin. In view of the above problems, the subject of the present invention is to provide a decorative film containing an acrylic resin that can achieve high adhesive strength with a substrate made of a polypropylene resin, and a scratch resistance, weather resistance, design, and recycling using the same. To provide a decorative molding having excellent properties.

In three-dimensional decorative thermoforming, it is necessary that the surface of the molded body and the film are sufficiently softened or melted in order to adhere the solid decorative film to the solid resin molded body. It is important to apply the amount of heat necessary to soften or melt the surface of the molded product and the film, but since the acrylic resin film softens in a relatively short time, if the heating time is too long, the viscosity of the film will decrease. We paid attention to the fact that film breakage and disturbance due to the push-up of the molded product in the original decorative thermoforming process and the inflow of air when returning the vacuum chamber box to atmospheric pressure lead to poor appearance. As a result, the sealing layer (I) made of a resin composition capable of exhibiting good adhesive strength containing polypropylene resin (A) and ethylene-α-olefin random copolymer (B) as main components, acrylic resin and an adhesive layer (III) made of an adhesive resin (D) between the sealing layer (I) and the layer (II) can solve the above problems. The discovery led to the completion of the present invention.

That is, the present invention includes the following.
[1] A decorative film to be adhered to a resin molding by thermoforming,
The decorative film contains a polypropylene resin (A) and an ethylene-α-olefin random copolymer (B) as main components, and the polypropylene resin (A) and the ethylene-α-olefin random copolymer (B) The weight ratio between the seal layer (I) made of the resin composition and the layer (II) made of the acrylic resin (C), and the seal layer (I) and the layer (II) including an adhesive layer (III) made of an adhesive resin (D) between
The polypropylene resin (A) satisfies the following requirements (a1),
A decorative film, wherein the ethylene-α-olefin random copolymer (B) satisfies the following requirements (b1) to (b3).
(a1) Melt flow rate (230° C., 2.16 kg load) (MFR(A)) exceeds 0.5 g/10 minutes.
(b1) The ethylene content [E(B)] is 65% by weight or more.
(b2) Density is 0.850 to 0.950 g/cm ³ .
(b3) Melt flow rate (230° C., 2.16 kg load) (MFR(B)) is 0.1 to 100 g/10 minutes.
[2] The decorative film of [1], wherein the ethylene-α-olefin random copolymer (B) satisfies the following requirement (b4).
(b4) The melting peak temperature (Tm(B)) is 30 to 130° C. [3] The ethylene-α-olefin random copolymer (B) is characterized by satisfying the following requirement (b5). The decorative film according to [1] or [2].
(b5) A random copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms.
[4] The adhesive resin (D) is a polyolefin resin having a polar functional group containing at least one heteroatom, and its MFR (230°C, 2.16 kg load) (MFR (D)) is 100 g. / 10 minutes or less The decorative film according to any one of [1] to [3], which is a polyolefin resin.
[5] The step of preparing the decorative film according to any one of [1] to [4], the step of preparing the resin molded body, and placing the resin molded body and the decorative film in a decompressible chamber box. setting, decompressing the inside of the chamber box, heating and softening the decorative film, pressing the decorative film against the resin molding, returning the decompressed chamber box to atmospheric pressure or heating A method for producing a decorative molding, comprising a step of pressing.
[6] The method for producing a decorative molded article according to [5], wherein the resin molded article is made of a propylene-based resin composition.

The decorative film of the present invention exhibits good adhesive strength to molded articles even when heated for a short period of time. can be done. According to the decorative film of the present invention, excellent design properties can be imparted to molded articles while taking advantage of the excellent properties of acrylic resins, such as transparency, scratch resistance, weather resistance, and ease of printing. .

1 is a diagram showing an example of the layer structure of the decorative film of the present invention; FIG. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view for explaining the outline of an apparatus used in the method for manufacturing a decorative molded article of the present invention; FIG. 3 is a schematic cross-sectional view for explaining how a resin molding and a decorative film are set in the apparatus of FIG. 2; FIG. 3 is a schematic cross-sectional view for explaining how the inside of the apparatus of FIG. 2 is heated and depressurized; FIG. 3 is a schematic cross-sectional view for explaining how a decorative film is pressed against a resin molding in the apparatus of FIG. 2; FIG. 3 is a schematic cross-sectional view illustrating how the inside of the apparatus of FIG. 2 is returned to atmospheric pressure or pressurized. FIG. 4 is a schematic cross-sectional view for explaining how the edge of the unnecessary decorative film is trimmed in the obtained decorative molded article. It is a figure which shows an example of the layer structure of the obtained decorative molding.

As used herein, a decorative film refers to a film for decorating a molded article. Decorative molding refers to molding in which a decorative film and a molded body are adhered together. Three-dimensional decorative thermoforming is a process of adhering a decorative film to a molded body, and includes a step of thermoforming the decorative film along the adhering surface of the molded body and simultaneously adhering it, In this step, thermoforming is performed under reduced pressure (vacuum) in order to prevent air from being entrained between the decorative film and the molded article, the heated decorative film is adhered to the molded article, and pressure is applied. It refers to molding, which is the process of bringing into close contact by releasing (pressurizing). BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described in detail.

The decorative film in the present invention is a decorative film to be adhered onto a resin molding by thermoforming,
The decorative film contains a polypropylene resin (A) and an ethylene-α-olefin random copolymer (B) as main components, and the polypropylene resin (A) and the ethylene-α-olefin random copolymer (B) The weight ratio between the seal layer (I) made of the resin composition and the layer (II) made of the acrylic resin (C), and the seal layer (I) and the layer (II) including an adhesive layer (III) made of an adhesive resin (D) between
The polypropylene resin (A) satisfies the following requirements (a1),
The ethylene-α-olefin random copolymer (B) is a decorative film characterized by satisfying the following requirements (b1) to (b3).
(a1) Melt flow rate (230° C., 2.16 kg load) (MFR(A)) exceeds 0.5 g/10 minutes.
(b1) The ethylene content [E(B)] is 65% by weight or more.
(b2) Density is 0.850 to 0.950 g/cm ³ .
(b3) Melt flow rate (230° C., 2.16 kg load) (MFR(B)) is 0.1 to 100 g/10 minutes.

[Seal layer (I)]
The decorative film of the present invention comprises a seal layer (I) made of a resin composition comprising a polypropylene resin (A) and an ethylene-α-olefin random copolymer (B). The seal layer (I) is a layer that comes into contact with the resin molding (substrate) during three-dimensional decorative thermoforming. By providing the seal layer (I), sufficient adhesive strength can be exhibited even if the film is heated for a short time during three-dimensional decorative thermoforming, and scratches on the substrate surface can be made inconspicuous.

[Polypropylene resin (A)]
The polypropylene-based resin (A) in the present invention includes various types of propylene-based resins such as propylene homopolymer (homopolypropylene), propylene-α-olefin copolymer (random polypropylene), and propylene block copolymer (block polypropylene). Polymers, or combinations thereof can be selected. The propylene-based polymer preferably contains 50 mol % or more of polymerized units derived from a propylene monomer. The propylene-based polymer preferably does not contain polymerized units derived from a polar group-containing monomer.

(a1) Melt flow rate (MFR (A))
The melt flow rate (230° C., 2.16 kg load) MFR (A) of the polypropylene resin (A) contained in the seal layer (I) must exceed 0.5 g/10 min, preferably 1 g /10 minutes or more, more preferably 2 g/10 minutes or more. Within the above range, relaxation at the time of three-dimensional decorative thermoforming progresses sufficiently, sufficient adhesive strength can be exhibited, and scratches on the substrate become inconspicuous. Although there is no upper limit for MFR(A), it is preferably 100 g/10 minutes or less. Within the above range, deterioration in adhesive strength due to deterioration in physical properties does not occur.

In this specification, the MFR of the polypropylene-based resin and the polypropylene-based resin composition described later was measured in accordance with ISO 1133:1997 Conditions M under the conditions of 230° C. and a load of 2.16 kg. The unit is g/10 minutes.

(a2) melting peak temperature (Tm (A))
The melting peak temperature (DSC melting peak temperature, sometimes referred to herein as the “melting point”) (Tm (A)) of the polypropylene resin (A) is preferably 110° C. or higher, and is preferably 115° C. or higher. and more preferably 120° C. or higher. Within the above range, the moldability during three-dimensional decorative thermoforming is good. Although the upper limit of the melting peak temperature is not limited, it is preferably 170° C. or less.

The polypropylene-based resin (A) in the present invention can be a resin polymerized by a Ziegler catalyst, a metallocene catalyst, or the like. That is, the polypropylene-based resin (A) can be a Ziegler catalyst-based propylene polymer or a metallocene catalyst-based propylene polymer.

[Ethylene-α-olefin random copolymer (B)]
The ethylene-α-olefin random copolymer (B) used as an essential component in the seal layer (I) of the present invention has the following properties (b1) to (b3), preferably further (b4) and/or (b5) ).

(b1) ethylene content [E (B)]
The ethylene content [E(B)] of the ethylene-α-olefin random copolymer (B) of the present invention is 65% by weight or more with respect to the total amount of the ethylene-α-olefin random copolymer (B). is required, preferably 68% by weight or more, more preferably 70% by weight or more. Within the above range, sufficient adhesive strength can be exhibited during three-dimensional decorative thermoforming, and the heating time of the film can be shortened. Although the upper limit of the ethylene content [E(B)] is not particularly limited, it is preferably 95% by weight or less.

(Calculation method of ethylene content [E (B)])
The ethylene content [E(B)] of the ethylene-α-olefin random copolymer (B) can be determined from the integrated intensity obtained by ¹³ C-NMR measurement.

(Calculation method 1 (binary system))
First, a method for calculating the ethylene content [E(B)] in a binary copolymer composed of two types of repeating units will be described. In this case, the ethylene content of the ethylene-α-olefin binary copolymer can be determined by (Formula-1-1) and (Formula-1-2).
Ethylene content (mol%) = IE × 100 / (IE + IX) (Formula-1-1)
Ethylene content [E (B)] (% by weight) = [ethylene content (mol%) x molecular weight of ethylene] x 100/[ethylene content (mol%) x molecular weight of ethylene + α-olefin content (mol%) x α- Molecular Weight of Olefin] (Formula-1-2)

Here, IE and IX are integral intensities for ethylene and α-olefin, respectively, and can be obtained by the following (formula-2) and (formula-3).
IE=(I _ββ +I _γγ +I _βδ +I _γδ +I _δδ )/2+(I _αγ +I _αδ )/4 (Formula-2)
IX= _Iαα +( _Iαγ + _Iαδ )/2 (Formula-3)
Here, the subscripts of I on the right side represent carbons described in structural formulas (a) to (d) below. For example, αα indicates the methylene carbon based on the α-olefin chain, and I _αα represents the integrated intensity of the signal of the methylene carbon based on the α-olefin chain.

構造式（ｄ）中、ｎは１以上の奇数を表す。
以下に、エチレン－α－オレフィン二元系共重合体のα－オレフィン毎に（式－２）、（式－３）に用いる積分強度について説明する。

In Structural Formula (d), n represents an odd number of 1 or more.
The integrated intensity used in (Formula-2) and (Formula-3) for each α-olefin of the ethylene-α-olefin binary system copolymer will be described below.

<For ethylene-propylene copolymer>
When the α-olefin is propylene, the ethylene content [E(B)] is obtained by substituting the following integrated intensity values into (Formula-2) and (Formula-3).
I _ββ =I _25.0-24.2
I _γγ =I _30.8-30.6
I _βδ = I _27.8-26.8
I _γδ =I _30.6-30.2
I _δδ = I _30.2-28.0
I _αα =I _48.0-43.9
I _αγ +I _αδ =I _39.0-36.2

Here, the numerical value subscripted to I on the right side indicates the range of chemical shift. For example, I _39.0-36.2 indicates the integrated intensity of the ¹³ C signal detected between 39.0 ppm and 36.2 ppm.
The chemical shifts are set to 1.98 ppm for the hexamethyldisiloxane ¹³ C signal and the chemical shifts for the other ¹³ C signals are referenced to this. Similar to ethylene-propylene copolymers, ethylene-1-butene copolymers, ethylene-1-hexene copolymers, and ethylene-1-octene copolymers are also described below.

<For ethylene-1-butene copolymer>
When the α-olefin is 1-butene, the ethylene content [E(B)] is obtained by substituting the following integrated intensity values into (Formula-2) and (Formula-3).
I _ββ =I _24.6-24.4
I _γγ =I _30.9-30.7
I _βδ = I _27.8-26.8
I _γδ =I _30.5-30.2
I _δδ = I _30.2-28.0
I _αα =I _39.3-38.1
I _αγ +I _αδ =I _34.5−33.8

<For ethylene-1-hexene copolymer>
When the α-olefin is 1-hexene, the ethylene content [E(B)] is obtained by substituting the following integrated intensity values into (Formula-2) and (Formula-3).
I _ββ =I _24.5-24.4
I _γγ =I _31.0-30.8
I _βδ = I _27.5-27.0
I _γδ =I _30.6-30.2
I _δδ = I _30.2-28.0
I _αα =I _40.0-39.0
I _αγ +I _αδ =I _35.0-34.0

そこで、５Ｂ６、６Ｂ６の重なりを補正したＩ_βδと、Ｉ_αγ＋Ｉ_αδを代用し、以下に示される積分強度を（式－２）、（式－３）に代入し、エチレン含量［Ｅ（Ｂ）］を求める。
Ｉ_ββ＝Ｉ_{２４．７－２４．２}
Ｉ_γγ＋Ｉ_γδ＋Ｉ_δδ＝Ｉ_{３２．０－２８．０}
Ｉ_βδ＝２／３×Ｉ_{２７．６－２６．７}
Ｉ_αα＝Ｉ_{４０．８－３９．６}
Ｉ_αγ＋Ｉ_αδ＝Ｉ_βδ＋２×Ｉ_ββ <For ethylene-1-octene copolymer>
When the α-olefin is 1-octene, the methylene carbon of the hexyl branch based on 1-octene overlaps the βδ signal and the αγ+αδ signal (5B6 and 6B6 in the structural formulas below).
I _βδ + I _5B6 = I _27.6-26.7
I _αγ +I _αδ +I _6B6 =I _35.0−34.0

Therefore, I _βδ corrected for overlap of 5B6 and 6B6 and I _αγ +I _αδ are substituted, and the integrated intensity shown below is substituted into (Equation-2) and (Equation-3), and the ethylene content [E (B )].
I _ββ =I _24.7-24.2
I _γγ +I _γδ +I _δδ =I _32.0-28.0
I _βδ = 2/3 x I _27.6-26.7
I _αα =I _40.8-39.6
I _αγ +I _αδ =I _βδ +2×I _ββ

(Calculation method 2 (ternary system))
Next, a method for calculating the ethylene content [E(B)] in a terpolymer composed of three types of repeating units will be described. For example, the ethylene content of the ethylene-propylene-butene terpolymer can be determined by the following (formula-4-1) and (formula-4-2).
Ethylene content (mol%) = IE × 100 / (IE + IP + IB) (Formula-4-1)
Ethylene content [E (B)] (% by weight) = [ethylene content (mol%) x molecular weight of ethylene] x 100/[ethylene content (mol%) x molecular weight of ethylene + propylene content (mol%) x molecular weight of propylene + butene content (mol%) x molecular weight of butene] (Formula-4-2)
Here, IE, IP, and IB are integral intensities for ethylene, propylene, and butene, respectively, and can be obtained by (Formula-5), (Formula-6), and (Formula-7).
IE=(I _ββ +I _γγ +I _βδ +I _γδ +I _δδ )/2+(I _αγ(P) +I _αδ(P) +I _αγ(B) +I _αδ(B) )/4 (Formula-5)
IP=1/3×[ _ICH3 (P)+ICH(P ₎ +Iαα _(PP) +1/2×(Iαα _(PB) + _Iαγ(P) + _Iαδ(P) )] (Formula- 6)
IB=1/4×[( _ICH3 (B)+ICH(B ₎ + _I2B2 +Iαα _(BB) )+1/2×(Iαα _(PB) + _Iαγ(B) + _Iαδ(B) )] .・(Formula-7)
Here, the subscript (P) means a signal based on propylene-derived methyl group branching, and similarly (B) means a signal based on butene-derived ethyl group branching.
Also, αα(PP) means a methylene carbon signal based on a propylene linkage, similarly αα(BB) refers to a methylene carbon signal based on a butene linkage, and αα(PB) refers to a methylene carbon signal based on a propylene-butene linkage. means a signal of

Here, the γγ signal overlaps with the tail of the central propylene methine carbon CH(PPE) signal aligned with propylene-propylene-ethylene, making it difficult to separate the γγ signal.
The γγ signal appears in structural formula (c) with two ethylene chains, and the integrated intensity of γγ derived from ethylene and the integrated intensity of βδ in structural formula (c) satisfy (formula-8).
I _βδ (structural formula (c)) = 2 × I _γγ (Formula-8)
Also, βδ appears in the structural formula (d) having three or more ethylene chains, and the integrated intensity of βδ in the structural formula (d) is equal to the integrated intensity of γδ (formula-9).
I _βδ (structural formula (d))=I _γδ (Formula-9)
Therefore, βδ based on Structural Formula (c) and Structural Formula (d) is obtained by (Formula-10).
I _βδ = I _βδ (structural formula (c)) + I _βδ (structural formula (d)) = 2 x I _γγ + I _γδ (Formula-10)
That is, I _γγ = (I _βδ - I _γδ )/2 (Formula-10′)
Therefore, by substituting (Formula-10') into (Formula-5), IE can be replaced with (Formula-11).
IE=(I _ββ +I _δδ )/2+(I _αγ(P) +I _αδ(P) +I _αγ(B) +I _αδ(B) +3×I _βδ +I _γδ )/4 (Formula-11)
Here, the βδ signal is corrected for the overlap of ethyl branches based on 1-butene, resulting in (Equation-12).
I _βδ = I _{αγ (P)} + I _{α δ (P)} + I _{α γ (B)} + I _{α δ (B)} −2 × I _{β β} (Formula-12)
From (Formula-11) and (Formula-12), IE becomes (Formula-13).
IE=I _δδ /2+I _γδ /4−I _ββ +I _αγ(P) +I _αδ(P) +I _αγ(B) +I _αδ(B) (Formula-13)
Substitute the following into (Formula-13), (Formula-6) and (Formula-7) to obtain the ethylene content.
I _ββ =I _25.2-23.8
I _γδ =I _30.4-30.2
I _δδ = I _30.2-29.8
I _αγ(P) + I _αδ(P) = I _39.5-37.3
I _αγ(B) +I _αδ(B) =I _34.6-33.9
I _CH3(P) = I _22.6-19.0
I _CH(P) = I _29.5-27.6 + I _31.2-30.4 + I _33.4-32.8
I αα _(PP) =I _48.0-45.0
I _CH3(B) = I _11.4-10.0
I _CH(B) = I _35.5-34.7 + I _37.4-36.8 + I _39.7-39.6
Iαα _(BB) =I _40.3-40.0
Iαα _(PB) =I _{44.2-42.0
I2B2} = _I26.7-26.4

For the assignment of each signal, the following five documents were referred to.
Macromolecules, Vol. 10, NO. 4, 1977,
Macromolecules, Vol. 36, No. 11, 2003,
Analytical Chemistry, Vol. 76, No. 19, 2004,
Macromolecules, 2001, 34, 4757-4767,
Macromolecules, Vol. 25, No. 1, 1992

Even if the α-olefin of the ethylene-α-olefin random copolymer is other than the above, each signal is assigned and the ethylene content can be determined in the same manner as described above.

(b2) Density The density of the ethylene-α-olefin random copolymer (B) must be 0.850 to 0.950 g/cm ³ , preferably 0.855 to 0.900 g/cm ³ , more preferably 0.86 to 0.890 g/cm ³ . Within the above range, sufficient adhesive strength is exhibited during three-dimensional decorative thermoforming, and film formability is also good.

(b3) Melt flow rate (MFR (B))
The melt flow rate (230° C., 2.16 kg load) MFR (B) of the ethylene-α-olefin random copolymer (B) must be 0.1 to 100 g/10 min, preferably 0. .5 to 50 g/10 minutes, more preferably 1 to 30 g/10 minutes. Within the above range, the effect of making scratches on the substrate inconspicuous is high.

(b4) melting peak temperature (Tm (B))
The melting temperature peak (DSC melting peak temperature) Tm(B) of the ethylene-α-olefin random copolymer (B) is preferably 30 to 130°C, more preferably 35 to 120°C, still more preferably 40. ~110°C. Within the above range, sufficient adhesive strength can be exhibited during three-dimensional decorative thermoforming.

(b5) α-olefin of ethylene-α-olefin random copolymer (B) The ethylene-α-olefin random copolymer (B) is a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. Preferably. Specific examples of α-olefins having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene and 1-decene. , 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene and the like. Among these, propylene, 1-butene, 1-hexene and 1-octene are particularly preferred.

Such an ethylene-α-olefin random copolymer (B) is produced by copolymerizing each monomer in the presence of a catalyst. Specifically, the ethylene-α-olefin random copolymer (B) can be produced by using a Ziegler catalyst, Phillips catalyst, metallocene catalyst or the like as an olefin polymerization catalyst, using a gas phase method, a solution method, or a high pressure method. can be produced by copolymerizing ethylene with α-olefins such as propylene, 1-butene, 1-hexene, 4-methyl-1-pentene and 1-octene in a process such as slurry method.

The ethylene-α-olefin random copolymer (B) used in the seal layer (I) of the present invention can be used singly or in combination of two or more as long as the effects of the present invention are not impaired.
Commercial products of such ethylene-α-olefin random copolymers include the Kernel series manufactured by Nippon Polyethylene Co., Ltd., the Toughmer P series and Toughmer A series manufactured by Mitsui Chemicals, Inc., and the Engage EG series manufactured by DuPont Dow. is mentioned.

[Resin composition]
The resin composition constituting the seal layer (I) contains a polypropylene resin (A) and an ethylene-α-olefin random copolymer (B) as main components, and the polypropylene resin (A) and ethylene- It may be a mixture or melt-kneaded product with the α-olefin random copolymer (B), or a sequential polymer of the polypropylene resin (A) and the ethylene-α-olefin random copolymer (B). good too.

In the resin composition of the sealing layer (I), the weight ratio ((A):(B)) of the polypropylene resin (A) and the ethylene-α-olefin random copolymer (B) is 97:3 to 5: It should be selected in the range of 95, preferably 95:5 to 10:90, more preferably 93:7 to 20:80. Within the above range, sufficient adhesive strength can be exhibited during three-dimensional decorative thermoforming, the heating time of the film can be shortened, and the adhesiveness between the sealing layer (I) and the layer (II) is good. be.

The resin composition forming the sealing layer (I) may contain additives, fillers, other resin components, and the like. However, the total amount of additives, fillers, other resin components, etc. is preferably 50% by weight or less with respect to the resin composition.

As additives, antioxidants, neutralizers, light stabilizers, ultraviolet absorbers, crystal nucleating agents, antiblocking agents, lubricants, antistatic agents, metal deactivators, etc., can be used in polypropylene resins. Various known additives can be blended.

Examples of antioxidants include phenol-based antioxidants, phosphite-based antioxidants, and thio-based antioxidants. Examples of neutralizing agents include higher fatty acid salts such as calcium stearate and zinc stearate. Hindered amines, benzotriazoles, benzophenones and the like can be exemplified as light stabilizers and ultraviolet absorbers.

Examples of crystal nucleating agents include amide-based nucleating agents such as aromatic carboxylic acid metal salts, aromatic phosphate metal salts, sorbitol derivatives, and rosin metal salts. Among these crystal nucleating agents, pt-butyl benzoate aluminum, 2,2′-methylenebis(4,6-di-t-butylphenyl)sodium phosphate, 2,2′-methylenebis(4 ,6-di-t-butylphenyl)aluminum, bis(2,4,8,10-tetra-tert-butyl-6-hydroxy-12H-dibenzo[d,g][1,2,3]dioxaphospho syn-6-oxide) complex of aluminum hydroxide salt and organic compound, p-methyl-benzylidene sorbitol, p-ethyl-benzylidene sorbitol, 1,2,3-trideoxy-4,6:5,7-bis-[ (4-Propylphenyl)methylene]-nonitol, rosin sodium salt and the like can be exemplified.

Examples of lubricants include higher fatty acid amides such as stearamide. Examples of antistatic agents include fatty acid partial esters such as glycerin fatty acid monoester. Examples of metal deactivators include triazines, phosphones, epoxies, triazoles, hydrazides, and oxamides.

As the filler, various known fillers that can be used for polypropylene resins, such as inorganic fillers and organic fillers, can be blended. Examples of inorganic fillers include calcium carbonate, silica, hydrotalcite, zeolite, aluminum silicate, magnesium silicate, glass fiber and carbon fiber. Examples of organic fillers include crosslinked rubber microparticles, thermosetting resin microparticles, thermosetting resin hollow microparticles, and the like.

Examples of other resin components include modified polyolefins, petroleum resins, and other thermoplastic resins.

The method for producing the resin composition includes a method of melt-kneading the polypropylene resin (A), the ethylene-α-olefin random copolymer (B), additives, fillers, other resin components, etc., and a polypropylene resin. A method of dry-blending an ethylene-α-olefin random copolymer (B) into a melt-kneaded mixture of (A), additives, fillers and other resin components, etc.; In addition to the random copolymer (B), additives, fillers, other resin compositions, etc. can be dispersed in a carrier resin at a high concentration, and a masterbatch can be dry-blended.

[Layer (II)]
The decorative film of the present invention contains a layer (II) made of an acrylic resin (C). By including the layer (II) made of acrylic resin (C), it has excellent design properties that make use of the excellent properties of acrylic resin such as transparency, scratch resistance, weather resistance, and ease of printing. A decorative molding can be obtained.

[Acrylic resin (C)]
The acrylic resin (C) in the present invention includes acrylic resins such as polymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate, methyl methacrylate-butyl methacrylate copolymer, and methyl methacrylate-styrene copolymer. Furthermore, a mixed resin of the above acrylic resin and thermoplastic polyurethane resin, or a mixed resin of the above acrylic resin and acrylic rubber can be used.

The acrylic resin (C) optionally contains general additives such as stabilizers, lubricants, processing aids, impact resistance aids, fillers, coloring agents, matting agents, ultraviolet absorbers, and the like. be able to. Commercially available acrylic resins such as "Acrypet" (trade name) manufactured by Mitsubishi Rayon Co., Ltd., "Sumipex" (trade name) manufactured by Sumitomo Chemical Co., Ltd., and the like can be preferably used as the acrylic resin.

[Adhesion layer (III)]
The decorative film of the present invention contains an adhesive layer (III) made of an adhesive resin (D). By providing an adhesive layer made of an adhesive resin (D), a layer (II) made of an acrylic resin and a sealing layer ( I) can be adhered without using an organic solvent.

[Adhesive resin (D)]
The adhesive resin (D) is a resin that exhibits adhesiveness to both the resin composition comprising the polypropylene resin (A) and the ethylene-α-olefin random copolymer (B) and the acrylic resin (C). Although there is no particular limitation, it is preferably a polyolefin resin having a polar functional group containing a heteroatom.

Polar functional groups containing hetero atoms include epoxy groups, carbonyl groups, ester groups, ether groups, hydroxy groups, carboxy groups or metal salts thereof, alkoxy groups, aryloxy groups, acyl groups, acyloxy groups, acid anhydride groups, An amino group, an imide group, an amide group, a nitrile group, a thiol group, a sulfo group, an isocyanate group, a halogen group and the like. Specific examples of polyolefins having such polar functional groups include acid-modified polypropylene such as maleic anhydride-modified polypropylene, maleic acid-modified polypropylene, and acrylic acid-modified polypropylene; ethylene/vinyl chloride copolymer, ethylene/vinylidene chloride copolymer; Copolymer, ethylene/acrylonitrile copolymer, ethylene/methacrylonitrile copolymer, ethylene/vinyl acetate copolymer, ethylene/acrylamide copolymer, ethylene/methacrylamide copolymer, ethylene/acrylic acid copolymer, ethylene /methacrylic acid copolymer, ethylene/maleic acid copolymer, ethylene/methyl acrylate copolymer, ethylene/ethyl acrylate copolymer, ethylene/isopropyl acrylate copolymer, ethylene/butyl acrylate copolymer , ethylene/isobutyl acrylate copolymer, ethylene/2-ethylhexyl acrylate copolymer, ethylene/methyl methacrylate copolymer, ethylene/ethyl methacrylate copolymer, ethylene/isopropyl methacrylate copolymer, ethylene/ Butyl methacrylate copolymer, ethylene/isobutyl methacrylate copolymer, ethylene/2-ethylhexyl methacrylate copolymer, ethylene/maleic anhydride copolymer, ethylene/ethyl acrylate/maleic anhydride copolymer, ethylene /metal acrylate copolymer, ethylene/metal methacrylate copolymer, ethylene/vinyl acetate copolymer or saponified product thereof, ethylene/vinyl propionate copolymer, ethylene/glycidyl methacrylate copolymer, Ethylene or α-olefin/vinyl monomer copolymers such as ethylene/ethyl acrylate/glycidyl methacrylate copolymer, ethylene/vinyl acetate/glycidyl methacrylate copolymer; chlorinated polypropylene such as chlorinated polyethylene Examples include polyolefins. Moreover, these resins may be used alone, or two or more of them may be mixed. Furthermore, if necessary, other resins or rubbers, tackifiers, various additives, and the like may be mixed.

Examples of the other resins or rubbers include polyα-olefins such as polypentene-1 and polymethylpentene-1, ethylene or α-olefin/α-olefin copolymers such as propylene/butene-1 copolymer, Ethylene or α-olefin/α-olefin/diene monomer copolymers such as ethylene/propylene/5-ethylidene-2-norbornene copolymers, polydiene copolymers such as polybutadiene and polyisoprene, styrene/butadiene random copolymers Polymers, vinyl monomer/diene monomer random copolymers such as styrene/isoprene random copolymers, vinyl monomers such as styrene/butadiene/styrene block copolymers, styrene/isoprene/styrene block copolymers Hydrogenated (vinyl monomer/diene monomer random copolymers), hydrogenation (styrene/butadiene/styrene block copolymers), hydrogenation (styrene/isoprene/styrene block copolymers) (vinyl monomer/diene monomer /vinyl monomer block copolymer), acrylonitrile/butadiene/styrene graft copolymer, methyl methacrylate/butadiene/styrene graft copolymer, and other vinyl monomer/diene monomer/vinyl monomer graft copolymers Polymers, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, polyvinyl acetate, polyethyl acrylate, polybutyl acrylate, polymethyl methacrylate, vinyl polymers such as polystyrene, vinyl chloride/acrylonitrile copolymers, vinyl chloride /vinyl acetate copolymer, acrylonitrile/styrene copolymer, methyl methacrylate/styrene copolymer, and other vinyl copolymers.

Examples of the tackifier include rosin-based resins (gum rosin, tall oil rosin, wood rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, maleated rosin, rosin ester, etc.), terpene phenol resins, terpene resins ( Polymers such as α-pinene, β-pinene, and limonene), aromatic hydrocarbon-modified terpene resins, petroleum resins (aliphatic, alicyclic, aromatic, etc.), coumarone/indene resins, styrene resins, Examples include phenol resins (alkylphenol, phenol xylene formaldehyde, rosin-modified phenol resin, etc.), xylene resins, and the like, and these can be used alone or in combination of two or more. Among these, from the viewpoint of thermal stability, rosin resins, terpene phenol resins, terpene resins, aromatic hydrocarbon-modified terpene resins, petroleum resins, and hydrogenated petroleum resins are preferred, and are compatible with the modified polyolefin resin of the present invention. However, rosin-based resins and terpene phenolic resins are particularly preferred because they can also contribute to adhesion to polar resins.

Examples of the additives include stabilizers such as antioxidants, metal deactivators, phosphorus-based processing stabilizers, ultraviolet absorbers, ultraviolet stabilizers, fluorescent whitening agents, metal soaps, antacid adsorbents, or cross-linking agents. , chain transfer agents, nucleating agents, lubricants, plasticizers, fillers, reinforcing agents, pigments, dyes, flame retardants, antistatic agents, etc., and may be added within a range that does not impair the effects of the present invention.

As commercially available polyolefin resins having a polar functional group, "ADMER" (trade name) manufactured by Mitsui Chemicals, "MODIC" (trade name) manufactured by Mitsubishi Chemical Co., Ltd., and "UMEX" manufactured by Sanyo Kasei Co., Ltd. can be preferably used.

Melt flow rate (MFR(D))
The melt flow rate (230° C., 2.16 kg load) MFR (D) of the adhesive resin (D) is preferably 100 g/10 min or less, more preferably 50 g/10 min or less, still more preferably 20 g/10 min or less. be. By setting the MFR (D) to the above value or less, it becomes possible to laminate the adhesive layer (III) comprising the adhesive resin (D) on the sealing layer (I) by extrusion molding. MFR(D) is preferably 0.1 g/10 minutes or more, more preferably 0.3 g/10 minutes or more. Co-extrusion molding of a resin composition comprising polypropylene resin (A) and ethylene-α-olefin random copolymer (B) and adhesive resin (D) by setting MFR (D) to the above value or more. , it is possible to suppress the occurrence of problems such as the occurrence of interface roughness at the lamination interface and the adhesive resin (D) not being laminated to the end of the film.

[Decorative film]
The decorative film in the present invention includes a seal layer (I) containing a resin composition comprising a polypropylene resin (A) and an ethylene-α-olefin random copolymer (B), a layer comprising an acrylic resin (C) ( II) and an adhesive layer (III) composed of an adhesive resin (D) is included in the order of seal layer (I)/adhesive layer (III)/layer (II). The decorative film can have various structures other than the sealing layer (I), the adhesive layer (III), and the layer (II). That is, even if the decorative film is a three-layer film consisting of the seal layer (I), the adhesive layer (III) and the layer (II), the seal layer (I), the adhesive layer (III) and the layer (II) A multi-layer film having four or more layers composed of other layers may also be used. The seal layer (I) is adhered along the resin molding (substrate). The surface of the decorative film may be textured, embossed, printed, sandblasted, scratched, or the like.

The decorative film has a large degree of freedom in shape, and the edge face of the decorative film is rolled up to the back side of the object to be decorated, so that no seam is formed, so that the appearance is excellent, and further, the surface of the decorative film is given a grain or the like. can express various textures. For example, in the case of imparting texture such as embossing to a resin molding, three-dimensional decorative thermoforming may be performed using an embossed decorative film. For this reason, there are problems when molding with a molded body mold that imparts embossing, that is, a molded body mold is required for each embossing pattern, and it is very difficult and expensive to apply complicated embossing to a curved surface mold. It is possible to solve the problem of being , and to obtain a decorative molded article to which various patterns of embossing are easily applied.

In addition to the sealing layer (I), the adhesive layer (III) and the layer (II), the multilayer film includes a surface layer, a surface decorative layer, a printed layer, a light shielding layer, a colored layer, a substrate layer, a barrier layer, and these layers. Tie layer layers and the like can be included that can be provided between layers.

In the multilayer film, the layers other than the seal layer (I), adhesive layer (III) and layer (II) are preferably thermoplastic resin layers, more preferably polypropylene resin layers. The layers other than the sealing layer (I), the adhesive layer (III) and the layer (II) are composed of the polypropylene-based resin as long as they can be distinguished from the sealing layer (I), the adhesive layer (III) and the layer (II). is not particularly limited. Each layer is preferably a layer containing no thermosetting resin. By using a thermoplastic resin, recyclability is improved, and by using a polypropylene-based resin, complication of the layer structure can be suppressed, and recyclability is further improved.

When the decorative film is a multi-layer film having four or more layers, from the adhesion surface side of the resin molding, the seal layer (I)/adhesive layer (III)/layer (II)/other layers (including a plurality of layers) are formed. and a configuration of sealing layer (I)/other layers (including multiple layers)/adhesive layer (III)/layer (II)/other layers (including multiple layers).

FIGS. 1(a) and 1(b) are explanatory diagrams schematically illustrating cross-sections of embodiments of the decorative film. In FIGS. 1(a) and 1(b), the arrangement of the sealing layer (I), the adhesive layer (III), and the layer (II) will be specified to facilitate understanding. should not be construed as being limited to these examples. In this specification, reference numeral 1 in the drawings is a decorative film, reference numeral 2 is a layer (II), reference numeral 3 is a sealing layer (I), reference numeral 4 is a printing layer (IV), reference numeral 5 is a resin molding, and reference numeral 7 is Adhesive layer (III) is shown. The decorative film of FIG. 1(a) consists of a seal layer (I), an adhesive layer (III) and a layer (II). As shown in FIG. Then, the adhesive layer (III) is laminated on the sealing layer (I), and the layer (II) is laminated on the adhesive layer (III) in this order. The decorative film in FIG. 1(b) consists of a sealing layer (I), an adhesive layer (III), a layer (II) and a printed layer (IV) made of a polypropylene resin, and as shown in FIG. A seal layer (I) is attached to the surface of 5, an adhesive layer (III) is printed on the seal layer (I), a layer (II) is printed on the adhesive layer (III), and a layer (II) is printed. Layer (IV) is laminated in this order.

The decorative film of the present invention preferably has a thickness of about 20 μm or more, more preferably about 50 μm or more, and even more preferably about 80 μm or more. By setting the thickness of the decorative film to such a value or more, the effect of imparting designability is improved, the stability during molding is also improved, and it becomes possible to obtain a better decorated molded product. On the other hand, the thickness of the decorative film is preferably about 2 mm or less, more preferably about 1.2 mm or less, still more preferably about 0.8 mm or less. By reducing the thickness of the decorative film to such a value or less, the time required for heating during thermoforming is shortened, thereby improving productivity and facilitating trimming of unnecessary portions.

In the decorative film of the present invention, the ratio of the thickness of the seal layer (I) to the total thickness of the decorative film is preferably 1 to 69%, and the ratio of the thickness of the adhesive layer (III) is preferably 1%. ∼69% and the proportion of the thickness of layer (II) is preferably between 30 and 98%. If the ratio of the thickness of the seal layer (I) to the entire decorative film is within the above range, sufficient adhesive strength can be exhibited. Further, when the ratio of the thickness of the adhesive layer (III) to the entire decorative film is within the above range, delamination between the layers (I) and (III) can be suppressed. Further, when the ratio of the thickness of the layer (II) to the entire decorative film is within the above range, it is possible to avoid insufficient thermoformability of the decorative film.

[Manufacturing of decorative film]
The decorative film of the present invention can be produced by various known molding methods.
For example, a sealing layer (I) containing a resin composition consisting of a polypropylene resin (A) and an ethylene-α-olefin random copolymer (B), an adhesive layer (III) consisting of an adhesive resin (D) and an acrylic A method of co-extrusion molding the layer (II) made of the resin (C) (with further layers), co-extrusion molding of the seal layer (I) and the adhesive layer (III) and further other layers, and pre-extrusion molding A thermal lamination method in which heat and pressure are applied to bond the layer (II) and the adhesive layer (III) so that the layer (II) and the adhesive layer (III) are in contact with each other on the surface of the layer (II) made of the acrylic resin (C). A layer (II) made of an acrylic resin (C), and a sealing layer (I) containing a resin composition made of a pre-extruded polypropylene resin (A) and an ethylene-α-olefin random copolymer (B). A dry lamination method and a wet lamination method for bonding through the adhesive layer (III), and on the surface of the layer (II) made of the pre-extruded acrylic resin (C), the adhesive layer (III) and the polypropylene Extrusion lamination method in which the resin (A) and the sealing layer (I) containing the resin composition composed of the ethylene-α-olefin random copolymer (B) are melt extruded, or the acrylic resin (C) is extruded in advance. The layer (II) and the sealing layer (I) containing a pre-extruded resin composition comprising a polypropylene resin (A) and an ethylene-α-olefin random copolymer (B) are melt-extruded to form an adhesive layer. Examples include a sand lamination method of adhering in (III). As a device for forming the decorative film, a known co-extrusion T-die molding machine or a known lamination molding machine can be used.

Methods for cooling the molten decorative film extruded from the die include a method of bringing the molten decorative film into contact with one cooling roll via air discharged from an air knife unit or an air chamber unit, A method of pressing and cooling with a plurality of cooling rolls can be used.

In the case of imparting gloss to the decorative film of the present invention, a mirror-finishing method is used in which a specular cooling roll is surface-transferred onto the design surface of the decorative film of the product.

Furthermore, the surface of the decorative film of the present invention may have a textured shape. Such a decorative film is produced by a method in which a melted resin extruded from a die is directly pressed between a roll having an uneven shape and a smooth roll to transfer the uneven shape. It can be manufactured by a surface transfer method or the like in which a heated roll and a smooth cooled roll are brought into pressure contact with each other. Examples of the embossed shape include pear-skin tone, animal skin tone, hairline tone, carbon tone, and the like.

The decorative film of the present invention may be heat-treated after being formed into a film. Examples of the heat treatment method include a method of heating with a hot roll, a method of heating with a heating furnace or a far-infrared heater, and a method of blowing hot air.

[Decorative molding]
As the molded article (decorative object) to be decorated in the present invention, various molded articles (hereinafter sometimes referred to as "substrate") preferably made of polypropylene resin or polypropylene resin composition can be used. . The molding method of the molded article is not particularly limited, and examples thereof include injection molding, blow molding, press molding, extrusion molding and the like.

Since the polypropylene resin is non-polar, it is a difficult-to-adhere polymer, but the decorative film in the present invention consists of the polypropylene resin (A) and the ethylene-α-olefin random copolymer (B). By including the seal layer (I) containing the resin composition, the decoration film made of polypropylene resin is stuck to the decoration object, thereby exhibiting extremely high adhesive strength and adhering to the surface of the decoration object. It can make scars less noticeable.

As base resins for polypropylene-based resins and polypropylene-based resin compositions, various known propylene monomers such as propylene homopolymers (homopolypropylene), propylene-α-olefin copolymers, or propylene block copolymers are mainly used. Various types of raw materials can be selected. In addition, it may contain a filler such as talc for imparting rigidity and an elastomer or the like for imparting impact resistance, as long as the effects of the present invention are not impaired. In addition, it may contain additive components and other resin components in the same manner as the polypropylene-based resin composition that can constitute the decorative film described above.

The decorative molded article obtained by attaching the decorative film of the present invention to various molded articles formed in a three-dimensional shape made of polypropylene resin has a greatly reduced amount of VOC contained in coatings and adhesives. It can be suitably used as home electric appliances, vehicles (railways, etc.), building materials, daily necessities, and the like.

[Manufacturing of decorative molding]
The method for manufacturing the decorated molded article of the present invention comprises the steps of preparing the above-described decorative film, preparing the resin molded article, and setting the resin molded article and the decorative film in a chamber box capable of reducing pressure. reducing the pressure in the chamber box; heating and softening the decorative film; pressing the decorative film against the resin molding; and returning or pressurizing the reduced pressure chamber box to atmospheric pressure. characterized by comprising

In three-dimensional decorative thermoforming, the object to be decorated and the decorative film are set in a decompressible chamber box, the film is heated and softened while the chamber box is decompressed, and the film is pressed against the object to be decorated. It has a basic process of attaching the decorative film to the surface of the object to be decorated by returning the inside of the chamber box to the atmospheric pressure or pressurizing it, and the film is attached under reduced pressure. As a result, it is possible to obtain a clean decorative molded article free from air pockets. In the manufacturing method of the present invention, any known technique can be used as long as the apparatus and conditions are suitable for three-dimensional decorative thermoforming.

That is, the chamber box may contain all of the objects to be decorated, the decorative film, the mechanism for pressing them, the device for heating the decorative film, etc., or the decorative film may A plurality of divided objects may be used.

The mechanism for pressing the decorative film against the decorative object may be of any type, such as one that moves the decorative object, one that moves the decorative film, or one that moves both.
More specifically, representative molding methods are exemplified below.

A method of adhering a decorative film to an object to be decorated using a three-dimensional decorating thermoforming machine will be exemplified below with reference to the drawings.

As shown in FIG. 2, the three-dimensional decorating thermoforming machine of this embodiment comprises upper and lower chamber boxes 11 and 12, and the decorating film 1 is thermoformed in the two chamber boxes 11 and 12. I'm trying A vacuum circuit (not shown) and an air circuit (not shown) are piped to the upper and lower chamber boxes 11 and 12, respectively.

A jig 13 for fixing the decorative film 1 is provided between the upper and lower chamber boxes 11 and 12 . A table 14 that can be raised and lowered is installed in the lower chamber box 12, and the resin molding (to be decorated) 5 is set on this table 14 (via a jig or the like or directly). be. A heater 15 is incorporated in the upper chamber box 11 and the decorative film 1 is heated by the heater 15 . The object to be decorated 5 can use a propylene-based resin composition as a base.

As such a three-dimensional decoration thermoforming machine, a commercially available molding machine (for example, NGF series manufactured by Fuse Vacuum Co., Ltd.) can be used.

As shown in FIG. 3, first, with the upper and lower chamber boxes 11 and 12 opened, the object to be decorated 5 is placed on the table 14 in the lower chamber box 12, and the table 14 is lowered. Subsequently, the decorative film 1 is set on the film fixing jig 13 between the upper and lower chamber boxes 11 and 12 so that the seal layer (I) faces the substrate.

As shown in FIG. 4, after lowering the upper chamber box 11 and joining the upper and lower chamber boxes 11 and 12 to close the inside of the box, the inside of each of the chamber boxes 11 and 12 is brought into a vacuum suction state, and the heater 15 is heated. The decorative film 1 is heated by.

After the decorative film 1 is heated and softened, the table 14 in the lower chamber box 12 is lifted while the upper and lower chamber boxes 11 and 12 are kept in a state of vacuum suction, as shown in FIG. The decorative film 1 is pressed against the object 5 to be decorated and covers the object 5 to be decorated. Further, as shown in FIG. 6, by opening the upper chamber box 11 to atmospheric pressure or supplying compressed air from a compressed air tank, the decorative film 1 is brought into close contact with the object 5 to be decorated with a greater force.

Subsequently, the interiors of the upper and lower chamber boxes 11 and 12 are opened to atmospheric pressure, and the decorative molding 6 is taken out from the lower chamber box 12 . Finally, as illustrated in FIG. 7, unnecessary edges of the decorative film 1 around the decorative molding 6 are trimmed.

(Molding condition)
The pressure reduction in the chamber boxes 11 and 12 is sufficient as long as air pockets are not generated, and the pressure in the chamber boxes 11 and 12 is 10 kPa or less, preferably 3 kPa, and more preferably 1 kPa or less.

In addition, in the two chamber boxes 11 and 12 divided into upper and lower parts by the decorative film 1, if the internal pressure of the chamber boxes 11 and 12 on the side to which the decorative object 5 and the decorative film 1 are attached is within this range, Well, by changing the pressure of the upper and lower chamber boxes 11 and 12, the drawdown of the decorative film 1 can be suppressed.

At this time, a film made of a general polypropylene-based resin may be greatly deformed or ruptured by a slight pressure fluctuation due to a decrease in viscosity during heating.

The decorative film 1 of the present invention is not only resistant to drawdown, but also resistant to film deformation due to pressure fluctuations.

Heating of the decorative film 1 is controlled by heater temperature (output) and heating time. It is also possible to measure the surface temperature of the film with a thermometer such as a radiation thermometer and use it as a guideline for appropriate conditions.

In the present invention, in order to adhere the polypropylene-based decorative film 1 to the decoration target 5 made of polypropylene-based resin, the surface of the resin molding 5 and the decorative film 1 must be sufficiently softened or melted.

Therefore, it is necessary that the heater temperature is higher than the melting temperature of the polypropylene-based resin that constitutes the object to be decorated 5 and the polypropylene-based resin that constitutes the decorative film 1 . The heater temperature is preferably 160° C. or higher, more preferably 180° C. or higher, and most preferably 200° C. or higher.

The higher the heater temperature, the shorter the time required for heating. If the temperature of the heater becomes too high, not only the moldability deteriorates but also the resin thermally deteriorates. It is below.

An appropriate heating time varies depending on the heater temperature, but it is preferable that the polypropylene-based decorative film is heated and heated for a period of time longer than the time until the polypropylene-based decorative film starts to stretch back, which is called springback.
In other words, the decorative film heated by the heater thermally expands when heated from a solid state, and once sagged as the crystals melt, and once the crystals melt, the molecules relax and temporarily spring back. After that, the film shows the behavior of sagging under its own weight, but after springback, the crystals of the film are completely melted and the molecules relax sufficiently, so that sufficient adhesive strength can be obtained.
Furthermore, surprisingly, the decorative film of the present invention can be strongly adhered to the substrate even if it is subjected to decorative thermoforming before the end of stretching, and it is also highly effective in suppressing untexturing.

On the other hand, if the heating time is too long, the film may sag under its own weight or be deformed due to the pressure difference between the upper and lower chamber boxes 11, 12. Therefore, the heating time should be less than 120 seconds after the end of springback. preferable.

In the case of decorating a molded article having a complicated shape having irregularities or in the case of achieving higher adhesive strength, it is preferable to supply compressed air when adhering the decorative film to the substrate. The pressure inside the upper chamber box 11 when the compressed air is introduced is 150 kPa or higher, preferably 200 kPa or higher, and more preferably 250 kPa or higher. Although there is no particular upper limit, the pressure is 450 kPa or less, preferably 400 kPa or less, since there is a risk of damaging the equipment if the pressure is too high.

EXAMPLES Hereinafter, the present invention will be described in more detail as examples, but the present invention is not limited to these examples.

1. Measurement method of various physical properties (i) Melt flow rate (MFR)
Measured according to ISO 1133:1997 Conditions M at 230° C. and a load of 2.16 kg. The unit is g/10 minutes.

(ii) melting peak temperature (melting point)
Using a differential scanning calorimeter (DSC), once the temperature was raised to 200° C. and held for 10 minutes, the temperature was lowered to 40° C. at a cooling rate of 10° C./min, and again at a heating rate of 10° C./min. The temperature of the endothermic peak top at the time of measurement was taken as the melting peak temperature (melting point). The unit is °C.

(iii) Density The density of the ethylene-α-olefin random copolymer (B) was measured according to JIS K7112: 1999 density gradient tube method.

(iv) ethylene content [E(B)]
The ethylene content [E(B)] of the ethylene-α-olefin random copolymer (B) was obtained from the integrated intensity obtained by ¹³ C-NMR measurement based on the method described above. Sample preparation and measurement conditions are as follows.
200 mg of the sample ethylene-α-olefin random copolymer (B) was mixed with 2.4 ml of o-dichlorobenzene/deuterated brominated benzene (C ₆ D ₅ Br) = 4/1 (volume ratio) and chemical shift It was placed in an NMR sample tube with an inner diameter of 10 mm and dissolved together with hexamethyldisiloxane as a reference substance.
The NMR measurement was performed using an AV400 type NMR apparatus manufactured by Bruker Biospin Co., Ltd. equipped with a 10 mm diameter cryoprobe.
The ¹³ C-NMR measurement conditions were a sample temperature of 120° C., a pulse angle of 90°, a pulse interval of 20 seconds, and an accumulation count of 512 times, and the broadband decoupling method was used.

2. Materials used (1) Polypropylene-based resins The following polypropylene-based resins were used.
(A-1): Propylene-α-olefin copolymer (MFR (A) = 7 g/10 min, Tm (A) = 146°C), manufactured by Japan Polypropylene Corporation, trade name "Novatec (registered trademark) FW3GT" ”
(A-2): Propylene homopolymer (MFR (A) = 10 g/10 min, Tm (A) = 161°C), manufactured by Japan Polypropylene Corporation, trade name "Novatec (registered trademark) FA3KM"

(2) Ethylene-α-olefin random copolymer The following ethylene-α-olefin random copolymer was used.
(B-1): ethylene-butene random copolymer (MFR (B) = 6.8 g/10 min, Tm (B) = 66°C, density = 0.885 g/cm ³ , ethylene content [E (B) ]=84% by weight): Mitsui Chemicals, Inc., trade name “Tafmer A4085S”
(B-2): ethylene-butene random copolymer (MFR (B) = 7.0 g/10 min, Tm (B) = 47°C, density = 0.860 g/cm ³ , ethylene content [E (B) ]=73% by weight): Mitsui Chemicals, Inc., trade name “Tafmer A4050S”
(B-3): ethylene-octene random copolymer (MFR (B) = 2.0 g/10 min, Tm (B) = 77°C, density = 0.885 g/cm ³ , ethylene content [E (B) ]=85% by weight): manufactured by DuPont Dow, trade name “Engage EG8003”
(B-4): ethylene-octene random copolymer (MFR (B) = 2.0 g/10 min, Tm (B) = 38°C, density = 0.860 g/cm ³ , ethylene content [E (B) ]=75% by weight): manufactured by DuPont Dow, trade name “Engage EG8842”
(B-5): ethylene-hexene random copolymer (MFR (B) = 3.5 g/10 min, Tm (B) = 60°C, density = 0.880 g/cm ³ , ethylene content [E (B) ]=76% by weight): manufactured by Japan Polyethylene Co., Ltd., trade name “Kernel KS340T”
(B-6): ethylene-propylene random copolymer (MFR (B) = 7.0 g/10 min, Tm (B) = 38°C, density = 0.860 g/cm ³ , ethylene content [E (B) ]=73% by weight): Mitsui Chemicals, Inc., trade name “Tafmer P0280”

(3) Acrylic resin (C)
(C-1): Polymethyl methacrylate resin film, manufactured by Mitsubishi Rayon Co., Ltd., trade name "Acryprene (registered trademark) HBS010P, film thickness 75 μm"

(4) Adhesive resin (D)
(D-1): Maleic anhydride-modified polyolefin (MFR (D) = 7 g/10 min), manufactured by Mitsubishi Chemical Corporation, trade name "Modic AP (registered trademark) F534A"
(D-2): Maleic anhydride-modified polyolefin (MFR (D) = 1.6 g/10 min), manufactured by Mitsubishi Chemical Corporation, trade name "Modic AP (registered trademark) F532"

3. Production of Resin Molded Article (Substrate) Using the following polypropylene resins (X-1) to (X-3), an injection molded article was obtained by the following method.
(X-1): Propylene homopolymer (MFR = 40 g/10 min, Tm = 165°C), manufactured by Japan Polypropylene Corporation, trade name "Novatec (registered trademark) MA04H"
(X-2): Propylene ethylene block copolymer (MFR = 30 g/10 min, Tm = 164°C), manufactured by Japan Polypropylene Corporation, trade name "Novatec (registered trademark) NBC03HR"
(X-3): 60% by weight of polypropylene resin (X-2), 20% by weight of EBR (Tafmer (registered trademark) A0550S manufactured by Mitsui Chemicals, Inc.) with MFR = 1.0, inorganic filler (Nippon Talc Talc P-6 manufactured by Co., Ltd., average particle size 4.0 μm) 20% by weight blended polypropylene resin composition Injection molding machine: "IS100GN" manufactured by Toshiba Machine Co., Ltd., mold clamping pressure 100 tons Cylinder temperature: 200 ° C.
Mold temperature: 40°C
Injection mold: Width x height x thickness = 120 mm x 120 mm x 3 mm flat plate Condition adjustment: Maintained for 5 days in a constant temperature and humidity room with a temperature of 23 ° C and a humidity of 50% RH

Example 1
・Production of decorative film Seal layer extruder-1 with a diameter of 30 mm (diameter) and adhesive layer extruder-2 with a diameter of 40 mm (diameter) are connected, 2 with a lip opening of 0.8 mm and a die width of 400 mm A seed two-layer T-die was used. A mixture of a polypropylene resin (A-1) and an ethylene-α-olefin random copolymer (B-1) blended in a sealing layer extruder-1 at a weight ratio of 85:15 was applied to an adhesive layer. The adhesive resin (D-1) is put into the extruder-2 for each, the resin temperature is 240 ° C., the discharge rate of the extruder-1 for the seal layer is 4 kg / h, and the discharge rate of the extruder-2 for the adhesive layer is was melt-extruded at 8 kg/h. The melt-extruded film is cooled and solidified while being pressed with an air knife against the first roll rotating at 3 m/min at 80° C. so that the seal layer is in contact with the first roll. A two-layer unstretched film was obtained.
The obtained unstretched film and the film (C-1) made of the acrylic resin (C) were each cut into a width of 250 mm and a length of 1000 mm so that the longitudinal direction was the MD direction of the film. The acrylic film cut out and the adhesive layer of the unstretched film cut out were overlapped so as to be in contact with each other, and integrated using a thermal laminator under the following conditions to obtain a decorative film. Thermal lamination conditions are described below.
Thermal lamination machine: Tester Sangyo Co., Ltd. "Small desktop laminator"
Heating conditions: Acrylic film contact surface, 130°C
Seal layer contact surface, 23°C
Pressurization conditions: 1.5 kgf/m
Line speed: 0.5m/min

• Three-dimensional decorative thermoforming As the resin molded body (substrate) 5, an injection molded body made of the polypropylene-based resin (X-1) obtained above was used.
"NGF-0406-SW" manufactured by Fuse Vacuum Co., Ltd. was used as a three-dimensional decoration thermoforming apparatus. As shown in FIGS. 2 to 7, the decorative film 1 was set on a film fixing jig 13 having an opening size of 210 mm×300 mm so that the seal layer faced the substrate. The resin molded body (substrate) 5 was placed on a sample installation table with a height of 20 mm, which was installed on a table 14 located below the film fixing jig 13, and placed on a sample installation table manufactured by Nichiban Co., Ltd. “Nice Tac NW-K15. ” pasted through. The film fixing jig 13 and the table 14 were installed in the chamber boxes 11 and 12, and the chamber boxes were closed to make the insides of the chamber boxes 11 and 12 airtight. The chamber box is vertically divided through the decorative film 1. - 特許庁The upper and lower boxes are evacuated and the pressure is reduced from the atmospheric pressure (101.3 kPa) to 1.0 kPa. heated. Vacuum suction was continued even during heating, and finally the pressure was reduced to 0.1 kPa. Twenty-five seconds after the decorative film 1 is heated, temporarily slackened, and then stretched back, the table 14 installed in the lower chamber box 12 is moved upward, and the resin molded body is obtained. The (substrate) 5 was pressed against the decorative film 1, and immediately after that, compressed air was fed into the upper chamber box 11 so that the pressure in the upper chamber box 11 was 270 kPa, and the resin molding (substrate) 5 and the decorative film 1 were brought into close contact with each other. Thus, a three-dimensional decorated thermoformed product 6 was obtained in which the decorative film 1 was adhered to the top and side surfaces of the resin molded body (substrate) 5 .

・Evaluation of physical properties (1) Evaluation of thermoformability (appearance of decorative molding)
Visually observe the drawdown state of the decorative film during three-dimensional decorative thermoforming and the adhered state of the decorative film to the decorative molded body in which the decorative film is adhered to the base, and use the criteria shown below. evaluated with
○: During the three-dimensional decorative thermoforming, the decorative film did not draw down and the base and the decorative film were in contact with each other over the entire contact surface at the same time. ing.
x: The decorative film was drawn down during the three-dimensional decorative thermoforming, resulting in uneven contact over the entire surface of the substrate.

(2) Adhesive strength between the resin molded body (substrate) and the decorative film "Craft Adhesive Tape No. 712N" manufactured by Nitoms Co., Ltd. was cut into a width of 75 mm and a length of 120 mm, and the edge of the resin molded body (substrate) was cut. The area of 75 mm×120 mm was affixed to a resin molded body (substrate) and masked (the exposed portion of the substrate surface had a width of 45 mm and a length of 120 mm). The resin molding (substrate) was placed in a three-dimensional decorative thermoforming apparatus NGF-0406-SW so that the masking surface of the resin molded body (substrate) was in contact with the decorative film, and three-dimensional decorative thermoforming was performed.

The decorative film surface of the obtained decorative molded product was cut with a cutter in a direction perpendicular to the longitudinal direction of the adhesive tape with a width of 10 mm up to the base surface to prepare a test piece. In the obtained test piece, the adhesive surface between the substrate and the decorative film had a width of 10 mm and a length of 45 mm. Attach the test piece to a tensile tester so that the base portion and the decorative film portion of the test piece are 180°, measure the 180° peel strength of the adhesive surface at a tensile speed of 200 mm / min, and measure the maximum strength at the time of peeling or breaking (N/10 mm) was measured five times, and the average strength was taken as the adhesive strength.

(3) Gloss The gloss (gloss) near the center of the decorative molded body to which the decorative film was attached was measured at an incident angle of 60° using a GLOSS meter VG2000 manufactured by Nippon Denshoku Industries Co., Ltd. . The measuring method complies with JIS K7105-1981.

Table 1 shows the physical property evaluation results of the obtained decorative moldings. The obtained decorative molding was excellent in appearance and adhesion.

Example 2
Evaluation was performed in the same manner as in Example 1, except that the ethylene-α-olefin random copolymer used in the seal layer in the production of the decorative film of Example 1 was changed to (B-2). Table 1 shows the evaluation results. The obtained decorative molding was excellent in appearance and adhesion.

Example 3
Evaluation was performed in the same manner as in Example 1, except that the ethylene-α-olefin random copolymer used in the seal layer in the production of the decorative film of Example 1 was changed to (B-3). Table 1 shows the evaluation results. The obtained decorative molding was excellent in appearance and adhesion.

Example 4
Evaluation was performed in the same manner as in Example 1, except that the ethylene-α-olefin random copolymer used in the seal layer in the production of the decorative film of Example 1 was changed to (B-4). Table 1 shows the evaluation results. The obtained decorative molding was excellent in appearance and adhesion.

Example 5
Evaluation was performed in the same manner as in Example 1, except that the ethylene-α-olefin random copolymer used in the seal layer in the production of the decorative film of Example 1 was changed to (B-5). Table 1 shows the evaluation results. The obtained decorative molding was excellent in appearance and adhesion.

Example 6
Evaluation was performed in the same manner as in Example 1, except that the ethylene-α-olefin random copolymer used in the seal layer in the production of the decorative film of Example 1 was changed to (B-6). Table 1 shows the evaluation results. The obtained decorative molding was excellent in appearance and adhesion.

Example 7
In the production of the decorative film of Example 1, except that the blending ratio of the polypropylene resin (A-1) and the ethylene-α-olefin random copolymer (B-1) was set to 70:30. Evaluation was performed in the same manner as in 1. Table 1 shows the evaluation results. The obtained decorative molding was excellent in appearance and adhesion.

Example 8
In the production of the decorative film of Example 1, except that the blending ratio of the polypropylene resin (A-1) and the ethylene-α-olefin random copolymer (B-1) was set to 30:70. Evaluation was performed in the same manner as in 1. Table 1 shows the evaluation results. The obtained decorative molding was excellent in appearance and adhesion.

Example 9
Evaluation was performed in the same manner as in Example 1 except that the adhesive resin used in the adhesive layer in the production of the decorative film of Example 1 was changed to (D-2). Table 1 shows the evaluation results. The obtained decorative molding was excellent in appearance and adhesion.

Example 10
Evaluation was performed in the same manner as in Example 1, except that the polypropylene resin used in the sealing layer in the production of the decorative film of Example 1 was changed to (A-2). Table 1 shows the evaluation results. The obtained decorative molding was excellent in appearance and adhesion.

Comparative example 1
In the production of the decorative film of Example 1, the ethylene-α-olefin random copolymer (B) was not blended in the sealing layer, and only the polypropylene resin (A-1) was used. A similar evaluation was performed. Table 1 shows the evaluation results.
Since the seal layer did not contain the ethylene-α-olefin random copolymer (B), the adhesion was poor.

Comparative example 2
In the three-dimensional decorative thermoforming of Comparative Example 1, evaluation was performed in the same manner as in Example 1, except that the heating time after springback was changed from 25 seconds to 40 seconds. Table 1 shows the evaluation results.
Since the heating time was long, the decorative film came into contact with the substrate in a saggy state due to its own weight, resulting in uneven contact over the entire decorative molded product and poor appearance.

Comparative example 3
Evaluation was performed in the same manner as in Example 1, except that only the acrylic film (C-1) was used in the production of the decorative film of Example 1. Table 1 shows the evaluation results.
Since no adhesive layer was laminated on the decorative film, it did not adhere to the substrate.

Example 11
Evaluation was carried out in the same manner as in Example 1, except that in the three-dimensional decorative thermoforming of Example 1, the substrate was changed to an injection molded body using resin (X-2). Table 1 shows the results obtained.
The obtained decorative molding was excellent in appearance and adhesion.

Example 12
Evaluation was carried out in the same manner as in Example 1, except that in the three-dimensional decorative thermoforming of Example 1, the substrate was changed to an injection molded body using resin (X-3). Table 1 shows the results obtained.
The obtained decorative molding was excellent in appearance and adhesion.

According to the present invention, it is possible to achieve both sufficient adhesive strength and product appearance, it is possible to reduce product defects by making scratches on the substrate inconspicuous, and it is used for three-dimensional decorative thermoforming that facilitates recycling. A decorative film and a method for producing a decorative molded article using the same are provided.

1 decorative film 2 layer (II)
3 sealing layer (I)
4 printed layer (IV)
5 Resin molding (decorative object, substrate)
6 Decorative molded body 7 Adhesive layer (III)
11 upper chamber box 12 lower chamber box 13 jig 14 table 15 heater

Claims (5)

preparing a decorative film; preparing a resin molded body; setting the resin molded body and the decorative film in a depressurizable chamber box; reducing the pressure in the chamber box; The step of heating and softening the film to generate springback , the step of pressing the decorative film against the resin molded body after the springback is completed, and the step of returning or pressurizing the pressure-reduced interior of the chamber box to the atmospheric pressure. A method for manufacturing a decorative molding characterized by:
The decorative film is a sealing layer (I) containing a resin composition containing a polypropylene resin (A) and an ethylene-α-olefin random copolymer (B), wherein the polypropylene resin (A ) and the ethylene-α-olefin random copolymer (B) is 50% by weight or more, and the weight ratio of the polypropylene resin (A) to the ethylene-α-olefin random copolymer (B) is 97:3 to 5:95, the sealing layer (I) containing the resin composition, the layer (II) containing the acrylic resin (C), and the adhesion between the sealing layer (I) and the layer (II) an adhesive layer (III) containing a flexible resin (D), wherein the sealing layer (I) is a layer in contact with the resin molded body,
The polypropylene resin (A) satisfies the following requirements (a0) and (a1),
A production method characterized in that the ethylene-α-olefin random copolymer (B) satisfies the following requirements (b1) to (b3).
(a0) The polypropylene-based resin (A) contains 50 mol % or more of polymerized units derived from a propylene monomer.
(a1) Melt flow rate (230° C., 2.16 kg load) (MFR(A)) exceeds 0.5 g/10 minutes.
(b1) The ethylene content [E(B)] is 65% by weight or more.
(b2) Density is 0.850 to 0.950 g/cm ³ .
(b3) Melt flow rate (230° C., 2.16 kg load) (MFR(B)) is 0.1 to 100 g/10 minutes. 2. The method for producing a decorated molded article according to claim 1, wherein the ethylene-α-olefin random copolymer (B) satisfies the following requirement (b4).
(b4) The melting peak temperature (Tm(B)) is 30 to 130°C. 3. The method for producing a decorated molded article according to claim 1, wherein the ethylene-α-olefin random copolymer (B) satisfies the following requirement (b5).
(b5) A random copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. The adhesive resin (D) is a polyolefin resin having a polar functional group containing at least one heteroatom, and its MFR (230° C., 2.16 kg load) (MFR (D)) is 100 g/10 min. 4. The method for producing a decorative molded article according to any one of claims 1 to 3, wherein the polyolefin resin is: 5. The method for producing a decorative molded article according to any one of claims 1 to 4, wherein the resin molded article contains a propylene-based resin composition.

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