JP5521877B2 - Printing method and method for producing decorative molded product - Google Patents

Description

  The present invention relates to a printing method by pad printing and a method for producing a decorative molded product.

Conventionally, a pad printing method is known as a method for directly forming a printed pattern on a curved surface or the like on a substrate. In general, in the pad printing method, ink is applied to the original intaglio plate, the ink on the convex portion is removed using a blade or the like, and the ink remaining in the concave portion is transferred onto the pad by pressing the soft pad. Further, the pad is pressed against the surface of the substrate to be printed so that the ink transferred on the pad is brought into contact with the surface of the substrate to be printed.
On the other hand, Patent Document 1 discloses a pad printing method in which printing accuracy is improved by using a relief printing original plate.

  However, when forming a multicolor printing pattern by these pad printing methods, it is necessary to repeat the printing process for each ink of different colors, which increases the number of work processes and is inferior in productivity. There's a problem. In addition, in order to perform high-quality multicolor printing without color misregistration, it is necessary to accurately match the printing positions in the printing process for each color, and there is a problem that printing accuracy is unstable.

JP-A-2-239972

  SUMMARY OF THE INVENTION An object of the present invention is to provide a pad printing method capable of performing multicolor printing on a substrate to be printed with a small number of steps and having stable printing accuracy.

As a result of intensive studies to solve the above problems, the present inventors transferred a printing layer onto a pad from a pad printing transfer sheet formed by laminating at least a printing layer on a base film, and this pad. It has been found that the above-mentioned problems can be solved by pressing padding on the substrate to be printed.
That is, the present invention
1. Using a transfer sheet for pad printing formed by laminating at least a printing layer on a base film, (A) applying an activator on the printing layer and softening at least a part of the printing layer, (B) softening Pressing the pad onto the printed layer and copying the softened printing layer; and (C) pressing the pad copied the softened printing layer onto the substrate and decorating it. A printing method comprising:
2. The printing method according to 1 above, wherein the printing layer is formed from an ink containing a cellulosic resin as a vehicle.
3. The above 1 or 2, wherein the activator contains 1 to 20% by mass of a phthalate ester, 60 to 90% by mass of an alcohol, 0 to 20% by mass of an ester excluding the phthalate ester, and 1 to 20% by mass of a ketone. 2, the printing method according to
4). In addition to the steps (A) to (C), (D) the printing method according to any one of the above 1 to 3, further comprising a step of forming a protective film on the transferred print layer,
5. 5. The printing method according to any one of 1 to 4 above, wherein the base film is formed using at least one selected from polyolefin resins and polyester resins. A method for producing a decorative molded product, wherein the printing method according to any one of 1 to 5 is used,
Is to provide.

  According to the transfer sheet for pad printing of the present invention, it is possible to perform multicolor printing with a small number of steps on a substrate and to perform pad printing with stable printing accuracy.

It is a schematic sectional drawing which shows an example of a structure of the transfer sheet for pad printing used by this invention. It is a schematic diagram which shows the process of apply | coating an activator on the printing layer of the transfer sheet for pad printing, and softening at least one part of this printing layer. It is a schematic diagram which shows the process of pressing a pad on the softened printing layer of the transfer sheet for pad printing, and copying the softened printing layer. It is a schematic diagram which shows the process which presses on the to-be-printed material the pad which copied the softened printing layer from the transfer sheet for pad printing, and decorates this.

[Printing method]
According to the present invention, the printed material can be transferred onto the printing material by using the transfer sheet for pad printing.
Hereinafter, the printing method of the present invention will be described.

  The printing method of the present invention uses a transfer sheet for pad printing formed by laminating at least a printing layer on a base film, (A) an activator is applied on the printing layer, and at least a part of the printing layer is softened (B) pressing the pad onto the softened printing layer and copying the softened printing layer; and (C) pressing the pad copied from the softened printing layer onto the substrate to be printed. The method includes a step of decorating.

<Process (A)>
In the step (A), as shown in FIG. 2, the activator 3 is applied on the printing layer 2 of the pad printing transfer sheet, and if necessary, the application surface of the activator is made uniform with a smoothing roll. In this step, at least a part of 2 is dissolved or swelled and activated to obtain a softened printing layer 4.
In this step, it is preferable to apply the activator 3 by supplying a transfer sheet for pad printing so that the printed layer 2 side faces upward.

The activator 3 is preferably applied by a spray coating method, a Miya bar coating method, or the like. The application amount of the activator 3 is usually 1 to 50 g / m ² , preferably 3 to 30 g / m ² , and more preferably 10 to 20 g / m ² .

  In addition, after the activator 3 is applied on the printing layer 2, the activator 3 soaks into the printing layer 2 and softens the ink. It is preferable to make the surface uniform. By adopting the smoothing roll, the applied surface of the applied activator 3 becomes uniform, and excellent design properties (transparency) and design reproducibility can be imparted to the printed material. In the present invention, the time until the activator 3 applied on the printing layer 2 soaks into the printing layer 2 and forms the printing layer 4 in which the ink is redissolved and softened is usually about 5 seconds to 3 minutes. .

  The smoothing roll is a roll having a mirror-like or groove-like plate on the surface, and the mirror-like or groove-like plate is actuated with the activator 3 while being rotated forward or counterclockwise with respect to the traveling direction of the pad printing transfer sheet 10. The coating surface is made uniform by touching the coating surface. When the surface of the smoothing roll has a groove-shaped plate, the depth of the groove can be appropriately set depending on the material of the base film 1, the coating amount of the activator 3, the state of the coating surface, and the like. 300 μm is preferable, 20 to 200 μm is more preferable, and there may be one groove or a plurality of grooves. The smoothing roll is preferably applied horizontally to the coated surface of the activator 3 from the viewpoint of making the painted surface of the activator 3 uniform, and is swung in the width direction of the transfer sheet 10 for pad printing. preferable. The rocking speed is usually about 1 to 20 mm / second, preferably 1 to 10 mm / second, and more preferably 2 to 7 mm / second. Moreover, what is necessary is just to set suitably the internal diameter, rotation speed, etc. of said smoothing roll by the material of the base film 1, the application amount of the activator 3, the state of an application surface, etc.

  The activator 3 has a function of dissolving or swelling at least a part of the printing layer 2 for transfer in the transfer sheet 10 for pad printing and softening it, which requires a certain amount of time. On the other hand, it is important not to volatilize until the process of transferring the printing layer to the printing surface of the printing material is completed. Therefore, in order to transfer the print layer to the printing material under optimum conditions in various usage situations, it is important to appropriately adjust the composition and coating amount of the activator 3 and the use conditions of the smoothing roll.

<Process (B)>
Step (B) is a step of copying the softened printing layer 4 by pressing the pad 5 on the softened printing layer 4 as shown in FIG.
The pad 5 is not particularly limited as long as it is a flexible and elastic member that can hold the printing layer 4 temporarily softened on the surface, but made of silicone rubber, urethane rubber, gelatin, nitrile rubber, etc. What has been conventionally used in pad printing can be specified, and usually has a hollow portion inside.
In the step (B), the ink applied on the intaglio original plate in the conventional pad printing method is copied onto the pad. Instead of the intaglio original plate, the ink is applied to the base film 1 obtained in the step (A). A pad printing transfer sheet 10 having a softened printing layer 4 is used.
In this step, it is preferable to press the pad 5 in a state where the pad printing transfer sheet 10 is fixed on a support (not shown) with the softened printing layer 4 side up, and more specifically, When the base film side is affixed to the support by sticking with a double-sided tape or the like, or by vacuum suction, peeling at the interface between the base film 1 and the softened printing layer 4 can be promoted.

<Process (C)>
As shown in FIG. 4, the step (C) is a step of pressing the pad 5 obtained by copying the softened printing layer 4 on the substrate 6 and decorating it.
Step (C) can be performed in the same manner as in the conventional pad printing method.

<Process (D)>
In the printing method of the present invention, in addition to the steps (A) to (C), a step (D) of forming a protective film on the transferred print layer may be added.
In the step (D), the printing layer transferred to the transfer surface of the printing material in the step (C) is coated as necessary to improve surface strength, protect the surface, and adjust the surface gloss. A transparent protective film is formed. As this transparent protective film, for example, a thermoplastic resin, a thermosetting resin, an ultraviolet curable resin, or the like, specifically, a urethane resin, an epoxy resin, an acrylic resin, a fluorine resin, a silicon resin, or the like is used. As a coating method, known methods such as spray coating, electrostatic coating, brush coating, and dip coating can be used.

[Pad printing transfer sheet]
The transfer sheet for pad printing used in the printing method of the present invention is formed by laminating at least a printing layer on a base film, and at least a part of the printing layer is dissolved or swollen and softened using an active agent. Then, the printed material can be decorated by transferring the softened printing layer onto the printed material by pad printing.
FIG. 1 is a schematic cross-sectional view showing an example of the configuration of a pad printing transfer sheet. The transfer sheet 10 for pad printing is provided with a printing layer 2 composed of a plurality of picture layers on a base film 1 by gravure printing or the like.

<Base film>
The base film 1 is not particularly limited as long as it is normally used as a printing sheet, but is preferably water-insoluble, and generally a plastic film can be suitably used. Examples of the plastic include those made of various synthetic resins. Synthetic resins include polyethylene resins such as polyethylene, polypropylene, polymethylpentene, and olefinic thermoplastic elastomers; vinyl resins such as polyvinyl chloride, polyvinylidene chloride, and ethylene-vinyl alcohol copolymers; polyethylene terephthalate and polybutylene terephthalate. Polyester resins such as polyethylene naphthalate and polyester-based thermoplastic elastomers; Acrylic resins such as poly (meth) methyl acrylate, poly (meth) ethyl acrylate and poly (meth) butyl acrylate; nylon 6 or nylon 66, etc. Representative polyamide resin; cellulose triacetate resin; cellophane; polystyrene; polycarbonate resin; polyarylate resin.
Of these, polyolefin resins and polyester resins are preferably used from the viewpoints of cost, mechanical strength, and the like, and stretched polypropylene and polyethylene terephthalate are particularly preferable from the viewpoints of handling properties and costs.

Although the thickness of the base film 1 is not specifically limited, The range of 10-400 micrometers is suitable. When it is 10 μm or more, the uniformity of the film is good and the production stability is high. On the other hand, when it is 400 μm or less, the rigidity of the film does not become too high and the printability is excellent. From the above viewpoint, the thickness of the base film 1 is more preferably in the range of 20 to 200 μm.
Moreover, an additive may be mix | blended with the synthetic resin used for the base film 1 as needed. Examples of the additive include a filler, a flame retardant, an antioxidant, a lubricant, a foaming agent, an ultraviolet absorber, and a light stabilizer.
From the viewpoint of peelability from the printing layer 2, the base film 1 may be provided with a release layer or a peeling layer on the surface on the printing layer 2 side.

<Print layer>
The pad printing transfer sheet 10 has a printing layer 2 for transfer, and as the ink for forming the printing layer 2, a conventionally known ink can be appropriately selected and used.
Examples of the pigment contained in the ink include inorganic materials such as titanium white, antimony white, lead white, iron black, yellow lead, titanium yellow, vermilion, cadmium red, ultramarine, cobalt blue, pearl pigment, and silver pigment such as aluminum paste. Pigments: Organic pigments such as carbo black (black ink), benzidine yellow, isoindolinone yellow, polyazo red, quinacridone red, indanthrene blue, and phthalocyanine blue can be used.

The vehicle contained in the ink is not particularly limited. For example, various oils such as linseed oil, soybean oil, synthetic drying oil; natural resins such as rosin, hardened rosin, rosin ester, polymerized rosin; phenol resin Synthetic resins such as rosin-modified phenolic resin, maleic acid resin, alkyd resin, petroleum resin, vinyl resin, acrylic resin, polyamide resin, epoxy resin, aminoalkyd resin, fluororesin; nitrocellulose, cellulose acetate butyrate Examples thereof include cellulose resins such as resins and ethyl cellulose; rubber derivatives such as chlorinated rubber and cyclized rubber; and other caseins, dextrins, and zeins. Among these, it is preferable to use a cellulose resin from the viewpoint of transferability to the pad.
The weight average molecular weight of the cellulose resin is preferably 100,000 or more, more preferably 300,000 to 6,000,000, and most preferably 500,000 to 2,000,000.

Moreover, it is preferable to add an ultraviolet absorber or a light stabilizer to the ink, and the weather resistance of the printing layer transferred to the transfer medium can be improved.
Examples of the ultraviolet absorber include organic compounds such as benzotriazole, benzophenone, and salicylic acid ester, and inorganic compounds such as fine particle zinc oxide and cerium oxide having a particle size of 0.2 μm or less. Examples thereof include hindered amine radical scavengers such as bis- (2,2,6,6-tetramethyl-4-piperidinyl) sebacate and radical scavengers such as piperidine radical scavengers.
In addition, content of these ultraviolet absorbers and light stabilizers is about 0.5 to 10% by mass on the basis of the total amount of ink.

  The solvent contained in the ink is not particularly limited, and aliphatic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, alcohols, ketones, ethers, acetate esters, esters, cellosolve, Nitro hydrocarbons, nitriles, amines, other acetals, acids, furans and the like can be mentioned. Among these, in consideration of the environment, it is preferable not to use aromatic hydrocarbons such as benzene, toluene, xylene, etc., and ethyl acetate, propyl acetate, butyl acetate, cellosolve, cyclohexanone, ethyl alcohol, isopropyl alcohol, isobutyl alcohol, Methyl ethyl ketone, methyl isobutyl ketone, propylene glycol mono-butyl ether, propylene glycol, and the like are preferably used from the viewpoint of solubility in the activator composition. In addition, these solvents can be used individually by 1 type or in mixture of 2 or more types.

Although it does not specifically limit as a method of forming the printing layer 2, For example, it can form by offset printing, silk screen printing, inkjet printing, gravure printing, etc.
A printing layer 2 is formed on one surface of the base film 1 by gravure printing or the like. When the multicolor printing layer 2 is formed, the printing layer 2 can be formed by providing two or more pattern layers. In this overprinting, for example, when printing a color photograph or the like, it is common to provide 3 to 7 picture layers. In four-color printing, for example, C (cyan), M (magenta), Y (yellow), and K (black) are generally used. In conventional pad printing, in the case of multicolor printing, depending on the number of colors, the printing layer transfer process from the original plate to the pad, the pad movement process, and the printing layer transfer process from the pad onto the substrate. However, when a pad printing transfer sheet comprising a plurality of pattern layers is used for the printing layer, even if the number of colors is large, it is not necessary to repeat the above series of steps. Since it can be greatly shortened and no color shift occurs, it is extremely useful in practice.

Although there is no restriction | limiting in particular in the thickness of each pattern layer which comprises the printing layer 2, Usually, about 0.1-10 micrometers, Preferably it is 0.5-5 micrometers.
Further, the amount of ink applied when forming each pattern layer is not particularly limited as long as the thickness of each pattern layer is within the above range, and is preferably 0.5 to 1.5 g / m ² . More preferably, it is 0.7-1.4 g / m < ² >.

<Activator>
The activator is applied to the printing layer 2 of the pad printing transfer sheet so that at least a part of the printing layer 2 is appropriately dissolved or swollen to be softened (activated). This state can be maintained until the printed matter is transferred.
The activator used in the present invention can be used as long as it dissolves or swells and softens at least a part of the printing layer 2. For example, a solvent such as esters, alcohols, and ketones is used. In particular, those containing 1 to 20% by mass of a phthalate ester, 60 to 90% by mass of alcohols, and 1 to 20% by mass of ketones are preferably used.

The activator used in the present invention preferably contains a phthalate ester as a plasticizer. The plasticizer is for imparting the activator with a function of softening the ink of the printing layer.
Preferred examples of the phthalic acid ester include phthalic acid diesters such as dimethyl phthalate, dibutyl phthalate, dioctyl phthalate, and diisooctyl phthalate. Of these, dimethyl phthalate and dibutyl phthalate are more preferable, and among them, dimethyl phthalate is preferable from the viewpoint of stabilizing the active state and evaporating with other solvents appropriately.

  Alcohols include ethyl alcohol (boiling point 78 ° C.), isopropyl alcohol (boiling point 82 ° C.), tert-butyl alcohol (boiling point 84 ° C.), n-propyl alcohol (boiling point 97 ° C.), 2-butyl alcohol (boiling point 99 ° C.). Examples include low-boiling alcohols having a boiling point of 70 to 100 ° C., high-boiling alcohols having a boiling point of more than 100 to 130 ° C. such as isobutyl alcohol (boiling point 108 ° C.), n-butyl alcohol (boiling point 117 ° C.), and the like. , Or a combination of two or more. Of these, isopropyl alcohol and isobutyl alcohol are preferred. In addition, it is preferable to use a low-boiling alcohol and a high-boiling alcohol in combination, particularly a combination of isopropyl alcohol and isobutyl alcohol, and a mass ratio of the blend is preferably 1: 7 to 1: 1, and 1: 7. ~ 1: 2 is more preferred.

The ketones preferably include those having a boiling point of 200 ° C. or lower, such as methyl ethyl ketone (boiling point 80 ° C.), methyl isobutyl ketone (boiling point 116 ° C.), dibutyl ketone (boiling point 187 ° C.), and diisobutyl ketone (boiling point 168 ° C.). Among these, at least one selected from dibutyl ketone and diisobutyl ketone is preferable.
To the activator used in the present invention, esters other than phthalate may be added.
Specific examples of esters other than phthalate esters include ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, sec-butyl acetate, tert-butyl acetate, methoxybutyl acetate, butyl carbitol acetate, and dibutyl oxalate. Is mentioned. Of these, acetates are preferable, and at least one selected from ethyl acetate, butyl acetate, and isobutyl acetate is preferable.

  The content of alcohol in the activator used in the present invention is preferably 60 to 90% by mass, and more preferably 70 to 90% by mass. It is preferable that content of ketones is 1-20 mass%, and 5-15 mass% is more preferable. Further, the content of the phthalate ester is preferably 1 to 20% by mass, and there is no problem that a part of the ink dissolves too early, and the pattern does not flow or distort. 15 mass% is more preferable, and 3-10 mass% is further more preferable. The content of esters other than phthalate is preferably 0 to 20% by mass, and more preferably 0 to 15% by mass.

The activator used in the present invention may contain aliphatic hydrocarbons and ethers.
Examples of the aliphatic hydrocarbon include heptane, 2-methylhexane, 3-methylhexane, 3-ethylpentane, octane, and isooctane. Among these, heptane is preferable.
Examples of ethers include butyl cellosolve and isoamyl cellosolve, and among these, butyl cellosolve is preferable.

  Moreover, about the activator used by this invention, the following resin can be added about 1-20 mass% with respect to a solvent, for example. Examples of this resin include vinyl halide polymers such as polyvinyl chloride and polyvinylidene chloride; styrene polymers such as polystyrene and polystyrene derivatives; vinyl ester polymers such as polyvinyl acetate; (meth) acrylic acid, itacon Polymers of ester derivatives of unsaturated carboxylic acids such as acid, crotonic acid, maleic acid or fumaric acid; polymers of nitrile derivatives or acid amide derivatives; N-methylol derivatives of acid amide derivatives of the above unsaturated carboxylic acids And the same N-alkylmethylol ether derivatives, glycidyl (meth) acrylate, allyl glycidyl ether, vinyl isocyanate, allyl isocyanate, 2-hydroxyethyl- (meth) acrylate, 2-hydroxypropyl- (meth) acrylate, ethylene glycol-mono ( A) Thermoplastic resins composed of monomers such as acrylates or copolymers; polyamide resins; polyester resins; phenol resins; melamine resins; urea resins; epoxy resins; diallyl phthalate resins Silicon resin; thermosetting resin such as polyurethane resin or modified resin or initial condensate thereof, natural resin, rosin and derivatives thereof, cellulose derivative such as nitrocellulose, natural or synthetic rubber, petroleum resin, cellulose acetate Examples thereof include cellulose resins such as butyrate (CAB) and nitrocellulose, and alkyd resins.

[Decorative molded products]
The present invention also provides a method for producing a decorative molded product using the printing method.
The decorative molded product obtained by the above method is suitably used as an automobile interior material, a building material, furniture, a housing for an electric product, or the like that requires particularly high designability.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
The decorative molded products obtained in each example were evaluated according to the following criteria.
(Evaluation method)
(1) Transfer state The transfer state of the pattern after the activated pattern was transferred to the substrate was visually evaluated. The evaluation criteria are as follows.
○: The pattern is uniformly transferred.
Δ: Some pictures are not printed.
×: The pattern is hardly transferred.

(2) Initial adhesion In the initial state in which the pattern was transferred to the printing material, the state of the pattern when water pressure was applied by a shower was visually evaluated. The evaluation criteria are as follows.
○: The pattern is not damaged by the water pressure, and the transferred state is maintained.
Δ: There is a portion where the pattern is slightly broken.
X: The design is broken and the design is impaired.

(3) Pinholes During transfer, pinholes due to solvent volatilization and the like were observed, and it was visually evaluated whether or not the pattern was transferred and the substrate was visible. The evaluation criteria are as follows.
○: No pinhole.
Δ: Some pinholes were observed, but there was no problem in practical use.
X: A pinhole occurred in the entire pattern.

(4) Pattern cracking After transferring the pattern to the printed material, the pattern was evaluated for cracks and fine cracks (pattern cracking) depending on the degree of dissolution of the printed layer by the activator. The evaluation criteria are as follows.
○: There is no pattern crack.
Δ: There is a crack in a part of the pattern.
X: There are fine pattern cracks and cracks as a whole, and there is no design reproducibility.

(5) Pattern flow After transferring the pattern to the printing material, the state (pattern flow) in which the pattern was displaced from the substrate or bent was evaluated due to the difference in the degree of dissolution of the printed layer by the activator. The evaluation criteria are as follows.
○: There is no pattern flow.
Δ: Pattern distortion in some areas.
X: A pattern flow occurs as a whole, and there is no design reproducibility.

(6) Throwing property It was visually evaluated whether or not the pattern was transferred along the curved surface of the printed material. The evaluation criteria are as follows.
○: The pattern is not cut and is transferred along the curved surface.
Δ: The pattern elongation is slightly non-uniform, but there is no practical problem.
X: There is a crack in the pattern, which impairs the design.

(7) Yuzu skin, surface irregularity The surface smoothness after being transferred to a printed material and dried was evaluated by visual and tactile sensations. The evaluation criteria are as follows.
○: Mirror surface and smooth surface.
Δ: Partially mat-like and slightly uneven, but practically no problem.
X: The entire surface is uneven and rough.

(8) Appearance The design of the printed material after it was transferred to the printed material, dried, and provided with a transparent protective layer was visually evaluated in consideration of the design and elongation. The evaluation criteria are as follows.
○: Good designability.
Δ: There are some defects in the design.
X: The design property is impaired as a whole.

Production Example 1 (Preparation of active agent)
Activator 1 was prepared by mixing 5 parts by mass of dimethyl phthalate, 30 parts by mass of isopropyl alcohol, 55 parts by mass of isobutanol and 10 parts by mass of diisobutyl ketone.

Production Example 2 (Preparation of active agent)
Activator 2 was prepared by mixing 60 parts by mass of butyl carbitol acetate, 20 parts by mass of butyl cellosolve, 10 parts by mass of dibutyl phthalate and 10 parts by mass of xylene.

Example 1
(1) Production of transfer sheet for pad printing A gravure ink [manufactured by DIC Graphics, “GT Color”, vehicle: cellulosic resin on one side of a stretched polypropylene film having a thickness of 18 μm by an electric gravure printing machine ( Weight average molecular weight: 1 million)], and a printing layer (wood pattern) having a thickness of 2 μm composed of the first pattern layer to the fourth pattern layer is formed by multicolor overprinting at a coating amount of 0.75 g / m ^2. Thus, a transfer sheet for pad printing was produced.
The amount of ink applied was determined by measuring the mass before and after ink application.

(2) Preparation of decorative molded product The transfer sheet for pad printing obtained in the above (1) was fixed on a mirror plate via a double-sided tape so that the printed layer faced upward, and prepared in Production Example 1. Activator 1 was applied at a coating amount of 4 g / m ² by the Miyabar coating method. After leaving at room temperature for 1 minute, the printed layer was transferred onto the pad by pressing the pad against the softened printed layer side of the pad printing transfer sheet for 10 seconds. Next, the printed layer transferred onto the pad was pressed against an ABS resin molded body as a printing material for 10 seconds to transfer the printing layer onto the printing material.
Next, the obtained object to be transferred was dried to obtain a decorative molded product to which the printing layer was transferred.
Next, an acrylic resin layer having a thickness of 10 μm was formed as a transparent protective layer on the surface of the print layer of the decorative molded product.
In addition, as for the application amount of the activator, 200 × 400 mm paper is prepared separately, and when the activator is applied under the same conditions as in each example, the mass of the paper before application, the mass within 10 seconds after application, Was measured as the difference in mass.
The results evaluated by the above method are shown in Table 1.

Examples 2-4
A transfer sheet for pad printing was prepared in the same manner as in Example 1 except that the activator and ink shown in Table 1 were used, and a decorative molded product was obtained using the pad transfer sheet.
The results evaluated by the above method are shown in Table 1.

Ink 1: (manufactured by DIC Graphics, “GT color”, vehicle: cellulosic resin, weight average molecular weight: 1 million)
Ink 2: (manufactured by DIC Graphics, “KLCF”, vehicle: cellulose resin, weight average molecular weight: 5 million)
Ink 3: (manufactured by DIC Graphics, “MA”, vehicle: cellulosic resin, weight average molecular weight: 5 million)

  According to the present invention, it is possible to perform multicolor printing on a substrate to be printed with a small number of steps and to perform pad printing with stable printing accuracy. The decorative molded product produced by the pad printing of the present invention can be suitably used as an automobile interior material, building material, furniture, a housing for an electric product, or the like.

1: base film 2: printing layer 3: activator 4: softened printing layer 5: pad 6: substrate 10: transfer sheet for pad printing

Claims (6)

  Using a transfer sheet for pad printing formed by laminating at least a printing layer on a base film, (A) applying an activator on the printing layer and softening at least a part of the printing layer, (B) softening Pressing the pad onto the printed layer and copying the softened printing layer; and (C) pressing the pad copied the softened printing layer onto the substrate and decorating it. A printing method comprising:   The printing method according to claim 1, wherein the printing layer is formed of an ink containing a cellulose resin as a vehicle.   The activator contains 1 to 20% by mass of a phthalate ester, 60 to 90% by mass of an alcohol, 0 to 20% by mass of an ester excluding the phthalate ester, and 1 to 20% by mass of a ketone. Or the printing method of 2.   The printing method according to any one of claims 1 to 3, further comprising (D) a step of forming a protective film on the transferred printing layer in addition to the steps (A) to (C).   The printing method according to claim 1, wherein the base film is formed using one or more selected from polyolefin resins and polyester resins.   A method for producing a decorative molded product, wherein the printing method according to claim 1 is used.

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