JP3322921B2 - Transfer sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer sheet, and more particularly, to a three-dimensional shaped base material (transfer object) constituting cabinets, doors and other fittings, furniture, containers, etc. of various audio and video equipments. The present invention relates to a transfer sheet suitable for applying a pattern to the surface of the sheet by a vacuum press transfer method or urethane foam molding transfer.

[0002]

2. Description of the Related Art As a method for producing a decorative material by transferring a pattern onto the surface of a molding base material having a three-dimensional shape, as described in Japanese Patent Publication No. 3-40720, etc. Print a pattern such as wood grain and an abstract pattern on the surface of the base material film with an ink made of a resin having releasability from the base film, and form an adhesive layer on the surface of the pattern pattern layer. A method in which the transfer sheet is adhered to the surface of a forming base material by a vacuum press laminating method using a transfer sheet, and then only the base film is peeled off from the pattern layer, JP-A-61-128543, Similarly, as described in JP-A-64-83000, an adhesive is applied to the surface of a molding substrate, and only a pattern layer is formed on the molding substrate in the same manner as described above. Adhes the formed transfer film That way, has been known.

[0003] However, in the above-mentioned method, when a permeable, porous and rough surface (having small irregularities) such as wood is used as a molding base, the rough surface having small irregularities is used. The adhesive did not come into contact with the concave portion, or the adhesive which was melted by heat was absorbed into the molding base material, resulting in problems such as insufficient adhesion. In the method described above, since the design pattern layer comes into direct contact with the liquid adhesive layer coated on the molding substrate, the design pattern is dissolved and fluidized by the residual solvent and monomer components of the adhesive layer. And then collapsed.

Further, there is another problem that air (bubbles) remains between the transfer sheet and the adhesive layer at the time of vacuum press laminating and molding, and transfer omission occurs. The present inventors have conducted intensive studies in order to obtain a method of manufacturing a decorative material that has solved the disadvantages of the conventional technology, and have succeeded in transferring or adhering a pattern to a molded substrate having a porous and rough surface. When the substrate film is peeled off, the pattern does not peel off together with the pattern, there is no dissolution and flow of the pattern due to the adhesive component, and air (bubbles) is generated between the transfer sheet and the adhesive layer. A new manufacturing method that can hardly remain is developed and already filed (Japanese Patent Application No. 4-240942).
issue).

[0005] That is, as shown in FIGS. 1 and 2, the surface of a base film 6 made of a thermoplastic resin is coated with an ink made of a resin having a good release property with respect to the base film 6. A pattern 7 such as an abstract pattern is printed, and a solid primer layer 8 having good adhesion to an adhesive 4 applied to a molding substrate 1 described later is formed on the surface of the pattern 7. A second step of applying a liquid adhesive 4 to the surface of the air-permeable base material 1, a pressing rubber-like elastic film 14 and a heating step. Press lamination molding machine 50 having heater 15 for
The molding substrate 1 coated with the adhesive is disposed on the suction table 21 in the above, and the molding is performed so that the primer layer 8 of the transfer sheet 5 and the adhesive layer 4 of the molding substrate 1 face each other. The transfer sheet 5 is set on the base material 1, and the rubber-like elastic film 14 is heated by the heater 15, and the transfer sheet 5 in the closed space formed between the rubber-like elastic film 14 and the suction table 21 is heated. Air is sucked in through air holes 23 formed in the suction table 21, and the rubber-like elastic film 14 is pressed against the molding base 1 as necessary, thereby transferring the transfer sheet 5 to the rubber-like elasticity. Membrane 1
A third step in which the primer layer 8 and the adhesive layer 4 are brought into close contact with each other by being pressed against the surface of the molding base 1 while being softened by heating in step 4; A fourth step of peeling the base sheet 6 from the transfer sheet 5 adhered to the substrate and leaving the pattern layer 7 on the surface of the molding base 1.

[0006] Here, the substrate film 6 constituting the transfer sheet 5 is preferably polyvinyl chloride (PVC), and the ink forming the pattern layer 7 is:
A nitrocellulose-based or cellulose-based resin can be used.
The most suitable material is selected depending on the material used for the adhesive layer 4 applied to the molding base 1, and the resin of the adhesive layer 4 is formed by crosslinking and polymerizing a polyurethane resin (that is, a mixture of a polyol and isocyanate). When a resin having a hydroxyl group in a molecule or a resin having an isocyanate group in a molecule is used, a polyurethane resin is used for both the adhesive layer 4 and the primer layer 8. When used, the adhesive layer 4 contains an excess of isocyanate groups and the primer layer 8 contains an excess of hydroxyl groups, or the adhesive layer 4 contains an excess of isocyanate groups and the primer layer 8 contains an isocyanate group. An aqueous emulsion-based adhesive is preferably used as the adhesive 4 to be applied to the molding substrate 1. In the resin system, the polyurethane or vinyl acetate resin is used, such as have been disclosed.

In the method of manufacturing a decorative material having the above-described structure, the primer 8 is interposed between the pattern layer 7 of the transfer sheet 5 and the adhesive layer 4 applied to the molding substrate 1. Therefore, even when the porous and rough molded substrate 1 is used, the distance between the pattern layer 7 and the primer layer 8
The adhesive strength between the primer layer 8 and the adhesive layer 4 and between the adhesive layer 4 and the molding substrate 1 can be increased,
Since the good releasability is secured between the base film 1 and the pattern layer 7, the pattern 7 can be satisfactorily transferred to the molding base 1, and the pattern 7 is removed together with the base film 6 when peeled off.転 写 剥離 剥離 転 写 、 、 、 、 剥離.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to further improve the stability of a pattern of a decorative material manufactured by the above-mentioned manufacturing method, that is, to further improve the adhesion strength. It is an object of the present invention to obtain a transfer sheet capable of transferring a printed picture pattern to a substrate with a strong adhesive strength.

[0009]

Means for Solving the Problems In order to solve the above-mentioned problems and achieve the object, the present inventors have continued intensive studies, and by doing so, the composition of the adhesive layer applied to the molding base material and When the composition of the layer constituting the contact surface where the transfer sheet is in contact with the adhesive layer has a specific relationship, it has been perceived that the adhesiveness of the pattern transferred to the molding substrate is particularly good. .

The present invention is based on the above perception,
Basically, a transfer sheet for a surface to be bonded, which is a urethane-based resin adhesive, wherein a layer in contact with the surface to be bonded is nitrocellulose resin having a degree of polymerization of 400 or less accounts for 50% or more of the resin ratio. A transfer sheet having at least a resin system is disclosed. The layer other than the layer in contact with the surface to be adhered in the transfer sheet may have a layer structure of a conventionally known transfer sheet, for example, a structure including a base film, a release layer, a pattern layer, a primer layer, or a base layer. A configuration consisting of only a material film and a pattern layer may be used. The picture layer may be formed from a plurality of printed layers, in which case the last printed layer is the layer that comes into contact with the surface to be adhered according to the present invention.

There is no particular limitation on a molding substrate (transfer object) to which a pattern is transferred by the transfer sheet according to the present invention, but a three-dimensional molded article made of a wooden material such as MDF (medium density fiber material), Porous materials such as earthenware and foamed resins (foams such as polyurethane and polyvinyl chloride) which are air-permeable are preferable. In this case, when the molding base is porous, when molding using a vacuum press laminating molding machine as described above, when the urethane-based adhesive described later is in a liquid state, part of the urethane-based adhesive is formed inside the molding base. Therefore, the anchoring hardening further increases the adhesive strength to the molding substrate.

A urethane-based resin is applied as an adhesive to the surface of the molding substrate to be adhered. Examples of urethane resins include TDI (tolylene diisocyanate) polypremer, polyfunctional aromatic polyisocyanate, diphenylmethane diisocyanate, HDI (hexamethylene diisocyanate) polypremer, xylylene diisocyanate polypremer, lysine isocyanate polypremer, and diisocyanate derived from dimer acid. And the like, and an appropriate reaction between an isocyanate polypremer represented by, for example, and a polyol represented by polyether polyol, polyester polyol, acrylic polyol, epoxy polyol, and the like.

The surface layer of the transfer sheet, which is in contact with the urethane resin adhesive layer applied to the surface to be bonded of the molding substrate, has a degree of polymerization of at least 400 to 20, preferably 100 to 30. It is composed of a resin system composed of a nitrocellulose resin and any other resin, and pigments, plasticizers, solvents, additives, and the like, which are added as needed.
Further, in the resin system, the nitrocellulose resin is configured to account for 50% or more of the resin ratio. According to the experiments of the inventors, the higher the ratio of nitrocellulose-based resin in the resin system, the better the adhesion, but the better.
When it was 100%, the printing adequacy was lowered, and when it was 50% or less, the adhesion strength was lowered. The degree of nitrification of the nitrocellulose resin is optional, but is preferably about 8 to 15%, particularly preferably about 10 to 13.

There is no particular limitation on other resin materials mixed with the nitrocellulose resin, but alkyd resins are preferred. An appropriate pattern is applied or printed on the base sheet via a release layer as necessary. Coating method,
The printing method is optional, and gravure coating, gravure reverse coating, intaglio printing, letterpress printing, or the like can be used arbitrarily. The picture layer may be a single layer or a multilayer,
Also, the material used to form the pattern layer of the conventional transfer sheet can be appropriately used as the material for forming the pattern layer,
At least the last layer to be coated or printed (it may be a so-called primer layer), that is, the outermost layer is made of a resin in which a nitrocellulose resin having a polymerization degree of 400 or less accounts for 50% or more of the resin ratio. It must be formed of at least the material having.

The method of transferring the transfer sheet having the above structure to a molding substrate is optional, but the vacuum press lamination transfer method disclosed in the above-mentioned Japanese Patent Application No. 4-240942 filed by the same person as the present application. Is particularly effective. Also in the case of urethane foam molding transfer, it is effectively used because a step of applying a urethane resin as an adhesive to the surface of a molding base can be omitted.

[0016]

In the transfer sheet according to the present invention having the above-described structure, the transfer surface of the urethane resin-based adhesive applied to the surface of the molding base material has a degree of polymerization of 400 or less. Since a layer having at least a resin system in which the cellulosic resin accounts for 50% or more of the resin ratio is adhered, it is possible to increase the adhesion to the surface of the molding base material and to have a more stable transfer pattern. A molded article can be obtained.

[0017]

[Example 1]

[Transfer sheet 1] Semi-rigid polyvinyl chloride sheet 8p (RIKEN vinyl R type) 0.08m /
m, and a pattern was printed thereon using gravure printing.

The composition of the ink used was as follows: (1) Resin A Nitrocellulose Nitrification degree 10.7-11.5 Polymerization degree 45.0-55.0 B Nitrocellulose Nitrification degree 10.7-11.5 Polymerization degree 55.0-70.0 A nitrocellulose / B nitrocellulose = 1/1 ... 5-15 Alkyd resin ... 1-6 (2) Pigment iron oxide, disazo yellow, cyanine blue, carbon ... 5-30 ( 3) Plasticizer DOP (Dioctyl phthalate) 3-6 (4) Additive Polyethylene wax 1 (5) Solvent Toluene / xylene / ethyl acetate / IPA 42-75 Adjust the amount of each composition to suit printing, and prepare a plurality of types.
The transfer sheet 1 was obtained by performing two colors and solid printing. The applied amount was 4 g / m ² in total. Example 2 Transfer Sheet 2 Nitrocellulose having a degree of polymerization of 25
A transfer sheet 2 was obtained by preparing an ink having the same composition as in Example 1 and performing the same printing on the same base material sheet, except for using the ones of 0 to 350. [Comparative Example 1] [Transfer sheet 3] Nitrification degree as nitrocellulose 11.
An ink having the same composition as in Example 1 was prepared and the same printing was carried out on the same base sheet, except that the ink having a composition of 5 to 12.2 and a degree of polymerization of 410 to 480 was used. [Comparative Example 2] [Transfer sheet 4] Same as Example 1 except that the resin ratio between the nitrocellulose resin and the alkyd resin was reversed so that the nitrocellulose resin was 50% or less of the resin ratio. An ink having the composition was prepared and the same printing was performed on the same base sheet to obtain a transfer sheet 4. [Comparative Test] Using the transfer sheets 1 and 2 according to the present invention and the transfer sheets 3 and 4 as comparative examples, a pattern was transferred by the vacuum press laminating method described above.

As a molding substrate, a urethane adhesive (KONISHI BOND CVC5) is applied to the surface of MDF (medium fiber board).
50) was spray-coated so as to give a coating amount of 100 g / m ² . The transfer surface of the transfer sheet was set on the sheet-side chamber side of the vacuum press-forming apparatus with the printing surface facing the forming base material, and the forming base material after application of the adhesive was set in the base-material-side chamber. Vacuum pressing conditions are: sheet temperature ... 75
° C, preheating time: 5 seconds, pressing time: 2 minutes, breath pressure ...
It was 2.5 kg / cm ² .

After forming, the base sheet of each transfer sheet was peeled off, and the ink was transferred to the forming base. In the transfer sheet 4, when the base sheet was peeled off, a part of the picture remained on the polyvinyl chloride sheet side as the base sheet, and complete transfer could not be performed. Next, a peeling test was performed on the transfer surface of each of the transfer molded products formed by the transfer sheets 1 to 4 using cellophane tape (Nichiban), and the transfer pattern was transferred by the transfer sheets 3 and 4 (Comparative Example). In the case of the transferred molded product, peeling occurred between the urethane adhesive and the transfer ink layer, but the transfer sheets 1 and 2 (the present invention)
In the case of the molded article to which the transfer pattern was transferred, the pattern layer hardly peeled off, and the pattern layer was in close contact with the molding substrate. In particular, in the case of the transfer sheet 1, the adhesion was good.

[0021]

By using the transfer sheet according to the present invention, it is possible to enhance the adhesion between the transfer pattern and the surface of the molding substrate, and it is possible to obtain a molded product having a more stable transfer pattern.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a vacuum press laminating apparatus, which is an example of an apparatus for transferring a picture using a transfer sheet according to the present invention.

FIG. 2 is a diagram provided for describing a transfer sheet and a forming base material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Molding base material 4 Adhesive layer 5 Transfer sheet 6 Base film 7 Picture pattern layer 8 Primer layer 50 Vacuum press lamination molding device 11 Sheet side chamber 14 Rubbery elastic film 15 Heater 21 Base material side chamber

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-63-89377 (JP, A) JP-A-59-148662 (JP, A) JP-A-3-32899 (JP, A) JP-A-59-14889 127791 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B44C 1/165-1/17

Claims (2)

(57) [Claims] 1. A vacuum press transfer method or urethane foaming.
Used to apply a pattern to the surface to be bonded, which is a urethane-based resin adhesive of a molding substrate having a three-dimensional shape by molding transfer
A transfer layer, wherein the layer in contact with the surface to be bonded has at least a resin system in which a nitrocellulose resin having a degree of polymerization of 400 or less accounts for 50% or more of the resin ratio. 2. The pattern according to claim 1, comprising at least a base film and a pattern printing layer, wherein at least the last printed layer of the pattern printing layer is a layer that contacts the surface to be bonded. Transfer sheet.