JP6381216B2 - Transfer sheet and composition for forming an adhesion layer used therefor - Google Patents

Description

  The present invention relates to a transfer sheet. More specifically, the present invention relates to a transfer sheet for peeling a pattern layer on which characters, patterns, etc. are displayed from a base material and sticking the pattern layer to an object to be decorated, and an adhesive layer forming composition used therefor.

  Conventionally, a transfer sheet has been used for decoration of curved surface portions that are difficult to directly print, such as pottery, wheels, helmets and the like of bicycles, motorcycles, and automobiles. In this type of transfer sheet, a pattern layer formed by printing is provided on the surface of a substrate so as to be peelable. Then, the pattern layer is peeled off from the base material of the transfer sheet, and the peeled pattern layer is pasted on a target decorative portion, for example, heated to 80 ° C. or more and baked to perform a print-like decoration. Yes. As for the peeling of the pattern layer, for example, imparting appropriate adhesion and peeling properties to the substrate to the pattern layer, or performing a water-soluble treatment on the surface of the substrate in advance, It is known that the pattern layer can be peeled off from the base material by being immersed in water. Patent document 1 is mentioned as a prior art regarding such a transfer sheet.

Japanese Patent Laid-Open No. 03-243399 Japanese Patent No. 3475252

  By the way, the pattern layer is generally formed by various printing techniques using ink made of a thermosetting resin. Therefore, when pasting on the object to be decorated, the pattern layer is brought into close contact with the object to be decorated by a heat treatment called baking as described above, and then cured and bonded. For this reason, the object to be decorated has, for example, high heat resistance thermoplastic resin material called so-called engineering plastic such as glass fiber reinforced plastic, and heat resistance such as thermosetting resin material such as urethane resin and epoxy resin. Intended for materials composed of materials. On the other hand, the decoration by the transfer sheet may not be applied to an object to be decorated made of a material having a relatively low heat-resistant temperature such as ABS resin (acrylonitrile / butadiene / styrene copolymer resin). there were.

  An object of this invention is to provide the new transfer sheet which can be manufactured by printing and can be affixed on a to-be-decorated object, without requiring a heating. Another object of the present invention is to provide a composition for forming an adhesion layer used for such a transfer sheet.

In order to achieve the above object, the present invention provides a transfer sheet. Such a transfer sheet is provided with a base material, a peelable adhesive layer provided on the base material, and a pattern layer printed on the adhesive layer. The adhesion layer includes an acrylic resin, a tackifier, and spherical inorganic particles.
That is, the transfer sheet disclosed here is not attached directly to the object to be decorated, but is attached via the adhesion layer. Therefore, heating is not necessary when the pattern layer is pasted by such a transfer sheet, and decoration can be performed on an object to be decorated that does not have heat resistance. Further, the formation of the pattern layer is not limited to using a thermosetting resin material.

  Furthermore, the adhesion layer is mainly composed of an acrylic resin, and has an appropriate tackiness by the tackifier, and excessive tackiness is suppressed by the spherical inorganic particles. Thereby, the adhesiveness which can adhere | attach the pattern layer favorably with respect to a base material or to-be-decorated object is realizable. At the same time, when producing such a transfer sheet, it has appropriate releasability (which can be low tack) with respect to other adherends while ensuring adhesion with the pattern layer. Can be realized. That is, for example, blocking that the adhesion layer provided on the substrate adheres to another substrate can be prevented, and adhesion of the plate making to the adhesion layer when printing the pattern layer can be prevented. In addition, since excessive adhesiveness is suppressed, fine adjustment such as needle correction can be performed at the time of application to a decoration object, and a transfer sheet excellent in workability can be provided.

In a preferred embodiment of the transfer sheet disclosed herein, the adhesion layer is formed on the substrate by screen printing.
According to this configuration, it is possible to accurately provide an adhesion layer having an appropriate shape according to the planar shape of the pattern layer on the substrate.

In a preferred embodiment of the transfer sheet disclosed herein, the pattern layer is formed in a region excluding the peripheral portion of the adhesion layer, and on the peripheral portion of the pattern layer and the adhesion layer, In addition, a clear layer is provided.
The clear layer is a transparent layer provided mainly for the purpose of imparting gloss to the pattern layer or protecting the pattern layer, and may preferably be colorless and transparent. Also for this clear layer, thermosetting resins have been widely used conventionally, but according to such a configuration, it becomes possible to attach this clear layer to an object to be decorated without heating through the adhesion layer. . Note that the term “transparent” as used in the present specification means that it is transparent to visible light (for example, a transmittance of light having a wavelength of 400 nm to 700 nm (for example, 550 nm) of 70% or more).

In a preferred embodiment of the transfer sheet disclosed herein, the spherical inorganic particles have a refractive index of 1.2 to 1.55. The spherical inorganic particles may be preferably spherical silica particles having an average particle diameter of 5 nm to 1000 nm.
When the refractive index of the spherical inorganic particles is in the above range, the refractive index can be close to that of the transparent acrylic resin, and the visibility of the object to be decorated as an adherend is enhanced through the adhesion layer. .
In addition, the refractive index regarding the spherical inorganic particles in the present specification is an absolute refractive index n ₁ indicating the refractive index with respect to the vacuum of the spherical inorganic particles, and can be measured based on the minimum deviation method using a spectrometer or the like. . In addition, from the relative refraction n ₁₂ (of the sample) with respect to the air defined by the Japanese Pharmacopoeia, using the known light speed in vacuum and light speed in air, the following formula: absolute refractive index n ₁ = (in air The absolute refractive index may be calculated from: (speed of light at ÷ speed of light in sample) × (speed of light in vacuum / speed of light in air).
In addition, the average particle diameter in the present specification is the particle diameter (50% volume average particle diameter; hereinafter abbreviated as D50) in the particle size distribution measured by a particle size distribution measuring apparatus based on the laser scattering / diffraction method. It may mean.)

In a preferred embodiment of the transfer sheet disclosed herein, the acrylic resin has a number average molecular weight of 1.5 × 10 ⁴ to 15 × 10 ⁴ .
When the average molecular weight is in the above range, good printability can be realized, and an adhesive layer having a desired form can be suitably realized. The number average molecular weight of the acrylic resin is more preferably 3 × 10 ⁴ to 10 × 10 ⁴ .

In a preferred embodiment of the transfer sheet disclosed herein, the elongation percentage of the post-peeling transfer sheet from which the substrate has been peeled is 120% or more.
By setting it as this structure, the transfer sheet which has moderate intensity | strength and the followability with respect to a to-be-decorated object is provided.

In a preferred embodiment of the transfer sheet disclosed herein, the rising slope in the stress-strain curve measured for the post-peeling transfer sheet from which the substrate has been peeled is 0.1 or more.
According to the stress-strain curve, the flexibility of the transfer sheet can be evaluated. By adopting the configuration as described above, a transfer sheet having an appropriate stiffness that does not cause tearing even when applied with a tensile force is provided.

In a preferred embodiment of the transfer sheet disclosed herein, the clear layer is composed of a polymer material including a crosslinked polyrotaxane structure.
According to such a configuration, a clear layer having flexibility even after curing is realized, and a transfer sheet having sufficient strength and followability to an object to be decorated having an aspect with a high curvature is provided. Also provided is a transfer sheet that is also self-healing with respect to scratches.

In a preferred embodiment of the transfer sheet disclosed herein, a water-soluble paste material is provided on the surface of the substrate on the side where the adhesion layer is provided.
According to this configuration, the paste material is dissolved in water by immersing the transfer sheet in water, and only the base material can be easily peeled off from the transfer sheet.

In a preferred embodiment of the transfer sheet disclosed herein, the base material is characterized by being composed of a fiber assembly in which fibers are aggregated.
By setting it as this structure, a water | moisture content can osmose | permeate easily to a base material, for example, melt | dissolution of a water-soluble paste material and peeling of a base material from a transfer sheet can be implement | achieved rapidly and simply.

In another aspect, the present invention provides an adhesive layer forming composition for forming an adhesive layer that is provided between a substrate and a pattern layer and can be peeled from the substrate together with the pattern layer. Such a composition for forming an adhesion layer is characterized in that an acrylic resin, a tackifier, and spherical inorganic particles are dispersed in an organic solvent.
According to such a configuration, there is provided an adhesive layer forming composition that can suitably bond the base material and the pattern layer in the transfer sheet and can be attached to an object to be decorated without requiring heating. The

In a preferred embodiment of the adhesive layer forming composition disclosed herein, the composition is prepared for screen printing.
According to such a configuration, there is provided an adhesive layer forming composition capable of precisely and easily forming an adhesive layer according to the form of the pattern layer by a screen printing method.

It is a cross-sectional schematic diagram explaining the structure of the transfer sheet which concerns on this invention. It is the figure which illustrated the result (a) (b) of the transparency test of the transfer sheet (adhesion layer). It is the figure which illustrated the stress-strain curve of the transfer sheet (transfer part). It is the elements on larger scale of FIG. 3A.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as appropriate. Note that matters other than the matters specifically mentioned in the present specification (for example, the configuration of the transfer sheet, etc.) and matters necessary for carrying out the present invention (for example, general techniques relating to printing methods such as screen printing) Can be understood as a design matter of those skilled in the art based on the prior art in the field. The present invention can be carried out based on the contents disclosed in this specification and common technical knowledge in the field. In addition, in the following drawings, the same code | symbol is attached | subjected and demonstrated to the member and site | part which show | plays the same effect | action, and the overlapping description may be abbreviate | omitted or simplified. In addition, the embodiments described in the drawings are modeled as necessary in order to clearly explain the present invention, and the dimensional relationship (length, width, thickness, etc.) of the actual transfer sheet is not necessarily accurate. It is not a reflection.

  FIG. 1 is a schematic cross-sectional view illustrating the configuration of a transfer sheet 1 disclosed herein. The transfer sheet 1 disclosed herein essentially includes a substrate 10, a peelable adhesion layer 20 provided on the substrate 10, and a pattern layer 30 printed on the adhesion layer 20. It is configured as follows. In a typical configuration, a clear layer 40 for mainly giving gloss or a surface protection (not shown) may be provided on the pattern layer 30. A part formed by peeling the adhesive layer 20 from the base material 10 and comprising the adhesive layer 20 and the pattern layer 30 (and the clear layer 40) (hereinafter, a member peeled together with the adhesive layer 20 from the base material 10 is referred to as a transfer portion). May be affixed to an object to be decorated (that is, an adherend). Hereinafter, each component will be described in detail.

[Base material]
The substrate 10 of the transfer sheet 1 disclosed herein can be composed of various materials conventionally used as a substrate of this type of transfer sheet. For example, it may be composed of a so-called non-porous structure sheet that does not exhibit water permeability, or may be composed of a so-called porous structure sheet that exhibits water permeability. Although there is no particular limitation on the transfer sheet having a structure in which the adhesion layer is peeled off by a wet method using a water-soluble paste material to be described later, it is preferable to use a base material made of a porous material. The porous material here may be any material that has substantially uniform voids (may be pores) over the entire substrate, and there is no particular limitation on the form and ratio of the voids. . As a preferable form of the base material made of such a porous material, a fiber aggregate in which fibers and the like are aggregated can be raised.

  As this fiber assembly, various kinds of paper typified by so-called Japanese paper and Western paper, knitted fabric (knit fabric, etc.), knitted fabric typified by lace, gauze, silk fabric, woven fabric typified by resin woven fabric, etc. It may be a nonwoven fabric represented by cloth, felt, resin nonwoven fabric or the like. Suitable fiber assemblies can be various papers, woven fabrics, and non-woven fabrics. Further, the fibers constituting the fiber assembly are not particularly limited, and may be fibers made of various natural or synthetic organic materials, or fibers made of metal materials, inorganic materials, and mixtures or composites thereof. It may be. Specifically, for example, natural fibers represented by pulp, cotton, wool, sufu (rayon), acetate, nylon, polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyester, etc. Examples thereof include inorganic fibers such as synthetic resin fibers, glass fibers, and carbon nanotubes, metal fibers such as metal whiskers, and blends thereof. These can be used alone or in combination of two or more according to the desired application. Although it does not restrict | limit especially about the thickness of this base material since it depends on a raw material etc., For example, setting it as the range of about 40 micrometers-about 500 micrometers is illustrated.

  The adhesion layer 20 is configured to be peelable from the base material 10. As the peeling method, a technique conventionally used for this type of transfer sheet can be employed. For example, any of dry and wet methods known as general peeling means may be employed. In the case of a dry process, the surface of the substrate 10 on the side where the adhesion layer 20 is provided may be subjected to an easy release treatment with a long-chain alkyl release agent, a silicone release agent, or the like. In the case of a wet type, a water-soluble paste material may be applied to the surface of the substrate 10 on the side where the adhesion layer 20 is provided. The water-soluble paste material is not particularly limited, and suitable examples include water-soluble resins such as polyvinyl alcohol (PVA), thickening polysaccharides such as dextrin, and the like. For example, in the case of a wet type, an appropriate amount of 5 to 20% by weight of water and an additive such as a stabilizer and a viscosity modifier are blended with respect to 100% by weight of a water-soluble paste material such as dextrin. Is preferably applied to the surface of the base material so that the thickness is about 0.1 to 1.0 μm. These release agents or water-soluble paste materials can be supplied (typically applied) to the surface of the base material and dried for easy release treatment. Application of such a release agent or water-soluble paste is easily carried out by using a conventional coater such as a gravure roll coater, reverse roll coater, kiss roll coater, dip roll coater, bar coater, knife coater, spray coater, etc. can do. Depending on the type of substrate, the substrate 10 may be dried at room temperature (25 ° C.) or at a temperature of about 40 to 120 ° C. after the release agent or water-soluble paste is applied.

[Adhesion layer]
As described above, the adhesion layer 20 exhibits a viscoelastic state in a temperature range near room temperature, and adheres to the base material 10 with a small pressure and is configured to be peelable. That is, heating is not required for attachment to the object to be decorated (which can be adhesion and adhesion). From this, this adhesion layer 20 can be grasped also as an adhesive layer. The adhesion layer 20 includes an acrylic resin, a tackifier, and spherical inorganic particles. More specifically, spherical inorganic particles are highly dispersed in an acrylic pressure-sensitive adhesive having an acrylic polymer as a base polymer. The base polymer means a main component among the polymer components, that is, a component contained in excess of 50% by mass. In general, acrylic polymers are characterized by transparency and excellent weather resistance. Therefore, by forming the adhesion layer 20 with an acrylic pressure-sensitive adhesive, for example, when the transfer sheet 1 is affixed to an object to be used outdoors, the adhesion layer 20 is less deteriorated and can be used for a long time. It is preferable because good decorative properties can be exhibited. In addition, the acrylic pressure-sensitive adhesive is such that the acrylic polymer itself can have adhesiveness, but the adherend may be limited depending on the polarity of the acrylic polymer. The tackifier imparts a function of improving the tackiness of the acrylic pressure-sensitive adhesive and adjusting the tackiness so that the adhesion layer 20 does not select the adherend according to the adherend. There is no restriction | limiting in particular in the thickness of this contact | adherence layer 20, For example, it can be set as the thickness of about 5 micrometers-50 micrometers. For example, the thickness can be designed so that the adhesion layer 20 can be provided with sufficient adhesive force, surface followability, and the like according to the surface form of the adherend (the presence or absence of unevenness and the degree thereof).

[Composition for forming an adhesion layer]
Such an adhesion layer 20 is, for example, for forming an adhesion layer capable of forming an adhesion layer in which instantaneous adhesion (so-called tackiness) is suppressed while exhibiting permanent adhesion (so-called adhesion or holding power). It can be constituted by a composition. For example, it can form suitably using the composition for adhesion layer formation indicated here. Such a composition for forming an adhesion layer can be prepared by highly dispersing spherical inorganic particles in an adhesive composition having an acrylic polymer as a base polymer.
Such an acrylic polymer may be various acrylic polymers that can be used for a general adhesive tape or the like. Typically, it may be a monomer mixture containing alkyl (meth) acrylate as a main monomer (a component accounting for more than 50% by weight of the whole monomer) and further containing a submonomer copolymerizable with the main monomer. This monomer mixture may optionally contain other copolymerization components in addition to these main monomer and submonomer. Then, these monomer mixtures are copolymerized to synthesize an acrylic polymer having a predetermined function, thereby forming the adhesion layer 20.

In the present specification, “(meth) acrylate” is a term meaning acrylate and methacrylate. Similarly, “(meth) acryl” is a term meaning acryl and methacryl.
As the alkyl (meth) acrylate, for example, a compound represented by the general formula: CH ₂ ═C (R ¹ ) COOR ² can be suitably used. Here, R ¹ in the formula represents a hydrogen atom or a methyl group. R ² represents a chain alkyl group having 1 to 20 carbon atoms. R ² is preferably an alkyl (meth) acrylate that is a chain alkyl group having 1 to 14 carbon atoms, and an alkyl (meth) acrylate that is a chain alkyl group having 1 to 10, for example, 2 to 8 carbon atoms. Is more preferable. Furthermore, an alkyl (meth) acrylate in which R ² is a butyl group or a 2-ethylhexyl group is preferable.

  Examples of the alkyl (meth) acrylate having a chain alkyl group having 1 to 20 carbon atoms include til (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n- Butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) Acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (me ) Acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate Eicosyl (meth) acrylate and the like. These alkyl (meth) acrylates may be used individually by 1 type, and may be used in combination of 2 or more type. Although not particularly limited, preferred alkyl (meth) acrylates include, for example, n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA).

  As a secondary monomer, it has a function of introducing a crosslinking point into the acrylic polymer or controlling the adhesiveness of the acrylic polymer, and a monomer component containing various functional groups depending on the properties of the desired adhesion layer. Can be used. Such functional groups can be, for example, carboxyl groups, hydroxy groups, amide groups, amino groups, epoxy groups, and the like. Although not particularly limited, it is preferable to use an ethylenically unsaturated monomer having a hydroxyl group. The amount of the submonomer is not particularly limited, and can be appropriately designed so as to realize desired adhesion layer characteristics. For example, from the viewpoint of balancing the cohesive strength and adhesiveness of the polymer in a well-balanced manner, the amount of the secondary monomer is 20% by mass or less, more preferably 15% by mass or less, more preferably 15% by mass or less, based on 100% by mass of alkyl (meth) acrylate. It is exemplified to be 10% by mass or less. In addition, you may make it include other copolymerization components other than the submonomer illustrated here.

  Preferred examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl ( (Meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, [4- (hydroxymethyl) cyclohexyl] methyl And hydroxyalkyl (meth) acrylates such as acrylate. A particularly preferred example is 2-hydroxyethyl methacrylate.

What is necessary is just to select suitably the ratio of the submonomer to the said monomer (total amount of a main monomer and a submonomer) according to the desired crosslinking degree, for example, about 1-10 mass% with respect to 100 mass% of all monomer components. It can be. The method for polymerizing the monomer mixture is not particularly limited, and conventionally known general polymerization methods (emulsion polymerization, solution polymerization, etc.) can be employed. In addition, what is marketed can also be utilized for said acrylic polymer. Although it does not specifically limit, As such an acrylic polymer, for example, a Dainar (registered trademark) BR series product manufactured by Mitsubishi Rayon Co., Ltd., and the like can be preferably mentioned.
In the adhesion layer, the proportion of the acrylic resin is preferably 40% by mass or more, and more preferably 50% by mass or more.

  The tackifier is added for the purpose of modifying the adhesion and tackiness of the acrylic resin to the adherend. The type of tackifier is not particularly limited, and can be appropriately selected from various crosslinking agents usually used for acrylic polymer applications in the field of adhesives and pressure-sensitive adhesives. For example, as the tackifier for the acrylic resin, rosin resin, hydrogenated petroleum resin, terpene resin, or the like can be used. Particularly preferred is a rosin ester which is an ester resin derived from a natural resin rosin. Although not particularly limited, the ratio of the tackifier to the acrylic resin is, for example, about 0.4 or more as the mass of the tackifier (B) / the mass of the acrylic resin (A). Is preferable, and more preferably about 0.5 to 1.

The pressure-sensitive adhesive composition includes other optional components such as a crosslinking agent, antistatic agent, anti-blocking agent, leveling agent, plasticizer, dispersant, colorant (pigment, dye, etc.), stabilizer, preservative, anti-aging agent. Various additives that can be generally used in the field of adhesives and pressure-sensitive adhesives such as an agent, a crosslinking accelerator, and a pH adjuster (typically an acid or a base) can be contained. The compounding amount of such an additive can be approximately the same as the compounding amount in a general adhesive composition.
In addition, although it does not specifically limit, the said adhesive composition can also be prepared as a solvent-type adhesive composition of the form melt | dissolved (or disperse | distributed) in various organic solvents. The solvent-type pressure-sensitive adhesive composition is desirable in that viscosity adjustment and uniform mixing can be easily realized, and since it is a homogeneous system, it is easy to form a pressure-sensitive adhesive layer having excellent transparency. The adhesion layer 20 having excellent transparency is advantageous in that it is difficult to visually recognize the presence of the adhesion layer when the clear layer 40 is adhered to the base material 10 or the modification object at the peripheral portion of the adhesion layer 20. It is.

By polymerizing this pressure-sensitive adhesive composition, an acrylic resin component that mainly forms an adhesion layer is constructed. The acrylic resin component preferably has a number average molecular weight (Mm) adjusted to about 1.5 × 10 ⁴ to 15 × 10 ⁴ . Thereby, for example, the adhesion layer 20 enters the fine irregularities on the attachment surface of the object to be modified to achieve strong adhesion, and the adhesion layer 20 itself is not torn or torn against unintended external force. The strength of the can be ensured. Here, when the adhesion layer 20 requires heat resistance, the number average molecular weight is generally increased (for example, 30 × 10 ⁴ or more). However, since such a transfer sheet does not need to be attached by heating, The number average molecular weight can be set relatively low. On the other hand, if the number average molecular weight is too large, tackiness is increased and printability is deteriorated. For example, when the adhesive layer forming composition containing such an adhesive composition is used as an ink and the adhesive layer 30 is formed by printing, the ink (adhesive layer forming composition) is not easily removed from the plate making, or the yarn This is not preferable because it causes pulling and it becomes difficult to achieve precise printing suitably. The number average molecular weight (Mm) is preferably about 10 × 10 ⁴ or less, more preferably about 8 × 10 ⁴ or less, and more preferably about 7 × 10 ⁴ or less. On the other hand, if the number average molecular weight is too small, the adhesion and adhesiveness deteriorate, which is not preferable. For example, after the transfer sheet is attached to the adherend, the transfer sheet once attached due to rubbing or impact may be peeled off, which is not preferable. The number average molecular weight (Mm) is preferably about 1.5 × 10 ⁴ or more, more preferably about 3 × 10 ⁴ or more, and more preferably about 4 × 10 ⁴ or more. .

Tackiness is defined as “one of the main properties of an adhesive, and is a force that adheres to an adherend in a short time (instantly) with a light force”, and is a so-called stickiness index. It can be. Such stickiness is an element completely different from the adhesive force and the like, and can be clearly distinguished. The adhesion layer 20 disclosed herein is adjusted so as to suppress tackiness lower than a general pressure-sensitive adhesive so as to suppress excessive stickiness while having appropriate adhesiveness.
That is, in the composition for forming an adhesion layer disclosed herein, the proportion of the acrylic resin in the acrylic resin, the tackifier, the spherical inorganic particles, and the solvent is about 20% by mass to 40% by mass, preferably Can be 20 mass%-35 mass%. If the amount of the acrylic resin is less than 20% by mass, the viscosity of the composition for forming an adhesion layer becomes too low, and it becomes difficult to obtain good printability. On the other hand, when the amount of the acrylic resin exceeds 40% by mass, it is not preferable because separation from the plate making at the time of printing is poor and stringing tends to occur.

  The spherical inorganic particles have a function of suppressing an increase in tackiness of the acrylic pressure-sensitive adhesive in the adhesion layer 30. As such spherical inorganic particles, for example, substantially spherical particles made of an inorganic material such as a metal oxide or glass can be used. That is, the spherical shape referred to in this specification is not limited to a so-called true spherical shape. The average particle diameter (D50) of the spherical inorganic particles may be about 5 nm to 1000 nm. If the average particle diameter of the spherical inorganic particles is too small, the thixotropy becomes too high when the spherical inorganic particles are dispersed in the acrylic pressure-sensitive adhesive composition, and the adhesive composition for forming an adhesion layer has an appropriate and easy-to-handle viscosity. It is not preferable because it becomes difficult to prepare. From this point of view, the average particle size of the spherical inorganic particles is preferably about 100 nm or more, more preferably 200 nm or more, for example, more preferably about 250 nm or more. Further, if the average particle size of the spherical inorganic particles is too large, it is difficult to maintain the transparency of the adhesion layer, which is not preferable. The transparency of the adhesion layer 30 can be a very important factor in a transfer sheet that requires design. Therefore, the average particle size of the spherical inorganic particles is preferably about 800 nm or less, more preferably about 500 nm or less, and for example, about 350 nm or less.

Moreover, although this spherical inorganic particle is not specifically limited, For example, it may be comprised from the inorganic material whose refractive index is 1.2-1.55 (for example, 1.4-1.5). preferable. When the refractive index is in the range, the refractive index is close to that of the acrylic resin mainly constituting the adhesion layer, and the visibility of the object to be decorated as an adherend is enhanced through the adhesion layer. That is, it is preferable because the presence of the spherical inorganic particles in the adhesion layer suppresses light from being refracted or scattered and makes it difficult to visually recognize the existence of the adhesion layer. The spherical inorganic particles having such refractive index, but are not particularly limited, particles such as of silica (SiO ₂₎ may be mentioned as preferred examples.

  The amount of the spherical inorganic particles can be appropriately set in consideration of the balance between the adhesiveness and tackiness of the adhesion layer 20. That is, the blending amount can be determined so that excessive stickiness does not occur while the pressure-sensitive adhesive layer 20 exhibits appropriate adhesiveness. Although it does not restrict | limit in particular, As a rough standard, it is illustrated that the ratio of the spherical inorganic particle which occupies for the contact | adherence layer 20 shall be the range of about 1 mass%-20 mass%. The ratio of the spherical inorganic particles in the adhesive composition for forming an adhesion layer can also be adjusted so that the ratio of the spherical inorganic particles in the adhesion layer 20 falls within the above range. For example, as an example, the proportion of spherical inorganic particles in the total amount of acrylic resin, tackifier, spherical inorganic particles and solvent is about 1% by mass to 15% by mass, more preferably about 2% by mass to 10% by mass. For example, the range of about 2% by mass to 6% by mass is exemplified. If the proportion of the spherical inorganic particles is too small, a transfer sheet with high adhesion and adhesiveness can be obtained, but the substrate that is layered when printing the pattern layer on the substrate with the pressure-sensitive adhesive layer becomes another substrate. It is not preferable because blocking that is adhered to the printed adhesion layer may occur or the printing plate making may adhere to the adhesion layer. On the other hand, when the proportion of the spherical inorganic particles is too large, tackiness can be suppressed, but it becomes difficult to realize sufficient adhesion, which is not preferable. The proportion of the spherical inorganic particles is more preferably about 2% by mass to 6% by mass as a proportion of the adhesion layer 20.

As described above, in the adhesion layer 20 disclosed herein, the balance between the provision of tackiness by the tackifier and the suppression of tackiness by the spherical inorganic particles can be important. This balance depends on the composition of the tackifier, the composition and the particle size of the spherical inorganic particles, etc., and cannot be generally stated. For example, the mass of the tackifier (B) / the mass of the spherical inorganic particles ( C) is preferably about 1 to 10, more preferably about 1.5 to 8. It is preferable that the mass ratio of the tackifier to the spherical inorganic particles is in such a range that both adhesiveness and low tack can be achieved in a desirable balance. Thereby, the adhesion layer 20 that can be cured without heating is realized.
Moreover, about the composition for contact | adherence layer formation, the composition excellent in printability can be obtained. The technique for printing such a composition for forming an adhesion layer is not particularly limited. For example, techniques such as offset printing, gravure printing, ink jet printing, and screen printing can be employed. Although the printability depends on the printing method employed and the conditions such as the plate making, it cannot be generally stated. However, according to such a pressure-sensitive adhesive composition for forming an adhesion layer, a specific example is 50 Screen printing using plate making of ˜350 mesh, for example, approximately 100 to 350 mesh is possible.

  The pattern layer 30 is a component that mainly bears the design that is the transfer purpose of the transfer sheet 1 and is formed on the adhesion layer 20 by printing. In a preferred embodiment of the transfer sheet 1 disclosed herein, the pattern layer 30 can be formed by screen printing (stencil printing). The ink composition used for printing the pattern portion 30 is not particularly limited, and may be composed of the ink used for the pattern layer 20 of the conventional transfer sheet 1 or a commercially available decorative ink. Can do. For example, it may be a heat-resistant ink (typically, an ink composition containing a thermosetting resin or glass flux as a binder together with an inorganic pigment), or a normal ink that is not particularly excellent in heat resistance (typically May be an ink composition containing a thermoplastic binder resin together with an inorganic pigment. Specifically, such an ink composition is prepared by dispersing or dissolving various coloring components and, if necessary, an adhesive, a solvent, a stabilizer, a plasticizer, a curing agent, and the like in an appropriate solvent (vehicle). Can be used. The ink composition can be devised in various ways depending on the characteristics of the object to be decorated and the detailed description thereof is omitted. For example, when a picture layer is pasted on the surface of the decoration, there are various types of ink. A composition (printing paste) obtained by adding a vehicle component to a paint component composed of a mixture of an inorganic pigment and glass flux can be employed. In the case of using such an ink containing glass flux, it is considered that the pattern layer is heated and cured prior to application. Moreover, when a picture layer is affixed to a helmet or the like, a composition (printing paste) in which various inorganic pigments are dispersed in a vehicle component can be employed.

Taking advantage of the transfer sheet 1 disclosed herein that can be attached without heating, it is preferable to form the pattern layer 30 using ink that does not require heating for curing. For example, ink that does not have heat resistance may be used. The pattern layer 30 can be formed by, for example, multicolor printing, and can be formed by printing a plurality of times by using different plate-making (color plates) for each predetermined color. That is, the pattern layer 30 may have a multilayer structure formed by overlapping a plurality of layers having a predetermined color, for example. For example, depending on the content of the pattern, one or more ink compositions (for example, three or more including three primary colors such as magenta, cyan, and yellow, or four or more including black added thereto) are prepared. It can be formed by printing for each color.
There is no restriction | limiting in particular in the thickness of this pattern layer 30, For example, it can typically be set as the thickness of about 20 micrometers-40 micrometers. However, since the pattern layer 30 is a structural layer mainly responsible for design properties, for example, the pattern can be intentionally provided with irregularities and bulges according to the contents of the pattern. In such a case, it goes without saying that the pattern layer 30 may have a desired thickness.

[Clear layer]
The clear layer 40 is a constituent layer that can be optionally provided in the transfer sheet disclosed herein for the purpose of protecting the surface of the transfer sheet 1 and giving gloss to the surface of the pattern layer 30. Such a clear layer 40 can be essentially colorless and transparent to visible light so as not to impair the pattern and design of the pattern layer 30. When the clear layer 40 is provided, the pattern layer 30 is formed in a region where the peripheral edge of the adhesion layer 20 is left, and the clear layer 40 and the adhesion layer 30 are completely covered with the pattern layer 30. It is preferable to form it on the periphery of 20. There is no restriction | limiting in particular in the constituent material etc. about this clear layer 40, It can comprise with the coating material etc. which were used for the clear layer in the conventional transfer sheet 1. FIG. For example, a coating material perm coat containing a glass flux with good transparency is supplied to the surface of the pattern layer 30 and the adhesion layer 20 with a uniform thickness of about 5 μm to 30 μm (for example, 10 μm), and is formed by curing. be able to. Further, for example, a clear coating material made of urethane resin is supplied to the surface of the pattern layer 30 and the adhesion layer 20 with a uniform thickness of about 5 μm to 30 μm (for example, 10 μm) and cured to form. Also good. However, if the transfer sheet 1 disclosed herein has the advantage of being able to be attached without heating, it is preferable to form the clear layer 40 using a material that does not require heating for curing. Suitable examples of such materials include acrylic resins and polymer materials having a crosslinked polyrotaxane structure.

  The polymer material having the crosslinked polyrotaxane structure has, for example, two or more polyrotaxane molecules as disclosed in Patent Document 2, and the crosslinked molecules in which cyclic molecules of the two or more polyrotaxane molecules are crosslinked through chemical bonds. It is a compound having a polyrotaxane at least in part. The polyrotaxane molecule can be explained conceptually as follows: two or more cyclic molecules as “rotors”, and linear molecules as “shafts” that are linked together by piercing the openings (rings) of the cyclic molecules. And blocking groups located at both ends of the linear molecule so that the skewered cyclic molecule is not detached. Such a cyclic molecule and a straight-chain molecule are in a non-covalently integrated inclusion state, and the cyclic molecule can easily move in the axial direction on the straight-chain molecule. In particular, if the cyclic molecules are sparsely linked on the large molecular weight linear molecule, the movement in the axial direction becomes easier. From a relative viewpoint, the polyrotaxane molecule is in a state where the linear molecule can easily move if the cyclic molecule is fixed. Therefore, even when the cyclic molecules form a crosslinked cyclic molecule, the linear molecule can easily move. For example, a polymer having a crosslinked polyrotaxane structure exhibiting such an action can easily form a crosslinked cyclic molecule or a straight-chain molecule even when stress is applied in a direction different from the direction in which it can easily move. By moving to, the internal stress can be made uniform and relaxed. In addition, such a polymer material may be a compound having an entropy elasticity much higher than that of a conventional physical gel due to its structure. That is, it can be a material that can form the clear layer 40 that exhibits high fracture strength, excellent extensibility, and excellent resilience and has very high entropy elasticity.

[Transfer section]
By forming the clear layer 40 from such a polymer material having a crosslinked polyrotaxane structure, the clear layer 40 has high breaking strength, excellent extensibility, and excellent restorability (also referred to as self-repairability). And high entropy elasticity. As a result, the entire post-peeling transfer sheet peeled from the base material, that is, the entire transfer part, imparts high breaking strength, excellent extensibility, excellent resilience, and high entropy elasticity. obtain.
From this point of view, the transfer sheet disclosed herein has a preferred embodiment in which the elongation percentage of the transfer portion is 120% or more. The elongation percentage is not strictly limited, but a suitable range is about 120% to 400%. Such elongation can be measured in accordance with the following procedure, for example, in accordance with the method for measuring elongation of the transfer part in accordance with JIS Z 0237: 2009 adhesive tape / adhesive sheet test method.

That is, first, a test sheet having a predetermined width (for example, a width of 10 mm) and a predetermined length (for example, about 300 mm) is cut out from the transfer sheet. In addition, after installing (pinching) the metal plates for installing the test pieces on the upper and lower chucks of the tensile tester, the chuck position is set so that the distance between the two metal plates on the tensile stress line is an appropriate interval. Adjust. Then, the transfer part is peeled off from the prepared test sheet to form a test piece, and a predetermined length (for example, about 100 mm) of both ends of the test piece is attached to two upper and lower metal plates, and the tensile tester is used. Install. After adjusting the chuck position so that the distance between the metal plates (corresponding to the marked line interval) is a predetermined interval (for example, about 100 mm), the test piece is moved to a predetermined tensile speed (for example, 10 ° C.) at room temperature (25 ° C.). The test piece is stretched until it breaks under the condition of ˜300 mm / min. Based on the stress-strain curve thus obtained, the elongation (E) can be determined from the following equation. The elongation of 120% or more may be a value that is difficult to achieve with a clear layer made of a urethane resin, which is a widely used thermosetting resin.
E = (L ₁ −L ₀ ) ÷ L ₀ × 100
L ₀ : First marked line interval
L ₁ : Distance between marked lines when cutting

  By setting it as the above structures, the transfer sheet which has moderate intensity | strength and the followability with respect to a to-be-decorated object is provided. That is, when the transfer sheet 1 disclosed herein is attached to an object to be decorated, it is possible to apply a certain amount of tension to contact the object to be decorated, and to decorate the transfer part so that wrinkles are unlikely to occur. Can be attached to objects. Further, for example, even if the object to be decorated has a curved surface, the modifying member can be attached to the object to be modified with good followability. Furthermore, even if tension is applied to the transfer portion, tearing is prevented and the transfer portion can be restored to its original shape after being attached, so that it is possible to prevent the design properties of the pattern layer 30 from being impaired. Such shape restoring property can be exhibited not only when the transfer sheet is attached, but also during daily use after application. For example, fine scratches formed on the surface of such a transfer sheet can be repaired over time.

Furthermore, the transfer sheet disclosed herein can be provided not only with the above-described extensibility as described above but also with an appropriate stiffness. Such stiffness reduces, for example, the occurrence of wrinkles when attaching the transfer portion, and also prevents the transfer portion from being excessively stretched by squeezing during wrinkle stretching or fine adjustment of the attachment position. Also have. As a result, transfer with good workability can be realized without impairing the design of the transferred pattern layer and the strength of the transfer portion. Such stiffness can be evaluated by, for example, the rising slope in the stress-strain curve measured for the transfer portion.
From such a viewpoint, the transfer sheet disclosed here evaluates that the inclination of the rising of the transfer portion is 0.1 or more as being favorable for sticking, and is a preferable embodiment. The slope of the rising can be calculated from the linear regression in the initial strain of the stress-strain curve obtained in accordance with the test method for tensile properties of plastic in JIS K 7161: 1994 for the transfer portion. That is, in a stress-strain curve obtained by cutting out a transfer portion from a transfer sheet to a predetermined width (10 mm) to obtain a test piece, and stretching the test piece at a room temperature (25 ° C.) under a tensile speed of 100 mm / min. The slope can be obtained by linear regression of a curve between two points (ε ₁ , ε ₂ ) in the defined initial strain region. Here, the two points (ε ₁ , ε ₂ ) for obtaining the inclination are not strictly limited as long as they are in the initial strain region (elastic region). For example, ε ₁ = 0.0005 and ε ₂ = 0.0025. Illustrated.
By setting it as this structure, the transfer sheet which has a favorable sticking characteristic is provided. That is, there is provided a transfer sheet having an appropriate stiffness that is unlikely to be broken by the tensile force at the time of pasting.

[Protective layer]
The transfer sheet 1 of the present invention described above has a protective layer (not shown) called a cover film or the like for the purpose of preventing the surface from being scratched or contaminated during transport or use. It can also be provided. The entire transfer sheet 1 or most of the transfer sheet 1 may be covered with a protective layer. By covering the pattern layer 30 or the clear layer 40 on the outermost surface of the transfer sheet 1 with such a protective layer, not only the design property of the pattern layer 30 but also the pattern layer 30 or the clear layer 40 is contaminated. Or the occurrence of scratches can be prevented. Such a protective layer can be formed of, for example, a polyolefin resin, a vinyl resin, a polyester resin, or the like.

<How to use>
The transfer sheet configured as described above can be used by peeling the adhesion layer 30 from the substrate 10 and attaching it to the object to be decorated. More specifically, for example, when the adhesion layer 30 is peeled off in a dry manner, the end of the adhesion layer 30 is lifted from the substrate 10, and the adhesion layer 30 (transfer portion) is pulled from the substrate 10. After being peeled off, it can be used by applying a desired tension and / or without applying a tension to the object to be applied at a desired application position and pressing it with a finger or the like. In order to facilitate peeling, a peeling tab or the like may be provided on the transfer portion to be peeled. Further, for example, when the adhesion layer 30 is peeled off by a wet process, the transfer sheet 1 is immersed in water to dissolve the water-soluble paste so that the adhesion layer 30 (transfer portion) is lifted from the substrate 10 and transferred. It can be used by recovering the portion and applying the desired tension and / or applying the desired tension to the desired application position of the object to be decorated and drying it. A water miscible solvent such as alcohol may be added to the water in which the transfer sheet 1 is immersed. In particular, transfer sheets in a form that is peeled off by wet do not complete bonding until the water adhering to the transfer area after drying is dry, so fine adjustment of the attachment position, wrinkle removal, air bleeding, and squeezing It is preferable at the point which can implement | achieve precise transcription | transfer with high designability. In any case, since the transfer sheet 1 disclosed herein includes the adhesion layer 20 having a good balance between adhesiveness and low tackiness, heating is not required during pasting.

<Application>
The transfer sheet disclosed here can be used by being attached to any object to be decorated. The to-be-decorated object here is not limited to the shape of the attachment site | part, For example, a thing with a flat surface may be sufficient, and it may have a surface containing an unevenness | corrugation, a curved surface, etc. Since such a transfer sheet has flexibility and can also have elasticity, it has excellent followability to unevenness, curved surfaces, and the like. Therefore, it is preferable to apply the surface including the unevenness and the curved surface to the object of sticking because the advantage is utilized. In addition, the object to be decorated is not limited to the material of the attachment site, and may be composed of a material having heat resistance, or may be composed of a material not having heat resistance. May be. For example, it can be various organic materials, inorganic materials, metal materials, and the like. Specifically, the organic materials include polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), polystyrene (PS), acrylonitrile butadiene styrene (ABS), acrylonitrile styrene (AS), polymethyl. General-purpose resin such as methacryl (PMMA), polyvinyl alcohol (PVA), polyethylene terephthalate (PET); polyamide (PA), polyacetal (POM), polycarbonate (PC), polyphenylene ether (PPE), polybutylene terephthalate (PBT) , Engineering plastics such as ultra high molecular weight polyethylene (U-PE), polyvinylidene fluoride (PVDF), glass fiber reinforced plastic (FRP); polysulfone (PSF), polyethersulfone (P S), polyphenylene sulfide (PPS), polyacrylate (PAR), polyamideimide (PAI), polyetherimide (PEI), polyetheretherketone (PEEK), polyimide (PI), liquid crystal polymer (LCP), polytetrafluoro Super engineering plastics such as ethylene (PTFE), phenolic resin (PF), urea resin (UF), melamine resin (MF), unsaturated polyester (UP), epoxy resin (EP), silicone resin (SI), polyurethane (PUR ) And the like. Examples of the inorganic material include ceramic and glass. Examples of the metal material include typical elements, carriers composed of metal elements, alloys, intermetallic compounds, and the like. Since such a transfer sheet does not require heating at the time of attachment, it is preferable to apply it to an adherend made of a material that does not have heat resistance because its advantages are utilized. Examples of such objects to be decorated include, for example, the bodies and accessories of vehicles (including bicycles, motorcycles, automobiles, trucks, buses, heavy machinery, etc.), household and industrial electrical equipment, building materials, and exercise. Instruments and the like can be included. More specifically, sports equipment such as helmets, golf clubs, rackets, and bats for various uses, and ceramics such as vases and tableware are included.

  Hereinafter, the adhesive layer forming composition and the transfer sheet disclosed herein and the production methods thereof will be described with reference to specific embodiments. However, it is not intended that the present invention be limited to the following examples.

[Test Example 1]
[Preparation of composition for forming an adhesive]
A composition for forming an adhesive material is prepared by dispersing (A) an acrylic resin, (B) a tackifier, and (C) spherical inorganic particles in an organic solvent with the formulation shown in Table 1 below. did. And No. which changed the ratio of (B) tackifier and (C) spherical inorganic particle into nine ways. The balance between the adhesion and the low tackiness of the adhesion layer formed using the adhesive composition forming compositions 1 to 9 was evaluated.
As the acrylic resin, a transparent thermoplastic resin, manufactured by Mitsubishi Rayon Co., Ltd., Dianar BR (Mn: about 5 × 10 ⁴ , Tg: about 15 ° C., acid value: 1.0 mgKOH / kg) Using. As the tackifier, Superester L (acid value: 18 or less, softening point VIS (mPa · s): 30,000 to 5,000) manufactured by Arakawa Chemical Industries, Ltd. was used. As the spherical inorganic particles, JA-244 (D50: 300 nm) manufactured by Jujo Chemical Co., Ltd., which is a spherical silica powder, was used. As the organic solvent, an isophorone-solvesso mixed solution was used. And after mixing these raw materials by the mixing | blending shown in Table 1 in presence of a dispersing agent and mixing using a stirrer etc., each raw material was disperse | distributed uniformly by performing a dispersion process, for example with a 3 roll mill. A composition for forming an adhesion layer was obtained. In the formulation shown in Table 1, the upper part shows the proportion of the non-volatile component (solid content), and the lower part () shows the proportion of the whole composition.

[Adhesion]
The adhesion of the adhesion layer was evaluated based on JIS K5600-5-6: 1999 paint general test method and adhesion (cross-cut method). That is, as the substrate, an ABS plate coated with urethane having a size of 200 mm × 70 mm was used, and No. prepared above on the surface of the substrate. 1-9 adhesive composition forming compositions were applied and dried to form an adhesive layer having a thickness of about 8-10 μm (the total thickness including the substrate was about 40-100 μm). The substrate on which such an adhesion layer was formed was used as a test plate for adhesion evaluation, and an adhesion test based on the cross-cut method was performed. The test plate was left to stand at room temperature (25 ° C.) for 24 hours and then subjected to an adhesion test.
Next, a cutting knife is applied so that the blade is perpendicular to the surface of the test plate, and a grid-like cut is provided at intervals of 1 mm at a depth reaching the substrate in the adhesion layer. A cross-cut was formed.
Cellophane tape (Nichiban Co., Ltd., plant cellophane tape 18 mm, CT405AP-18) cut to about 75 mm was firmly crimped with fingers in a direction parallel to the cuts on the grids formed in this way. Next, the end of the tape was peeled off at an angle of 60 ° from 0.5 seconds to 1 second, and the state of the grids was classified by comparison with a standard drawing. ) "Column. “Category” indicating adhesion is a classification of the state of peeling (peeling) of the adhesive layer into six stages from “0” to “5”, and is in accordance with JIS regulations. The larger the value, the more the adhesion layer peels from the substrate, indicating poorer adhesion. In the present embodiment, classification “1” or less (peeling less than 5%) can be evaluated as having good adhesion.

[Tackiness]
As a substrate, a commercially available transfer paper (thickness: 200 μm) with one side coated with a water-soluble paste was prepared. And in this base material, the No. prepared above. The adhesion layer was screen-printed using 1 to 9 adhesion material forming compositions, and 100 substrates each having an adhesion layer made of each adhesion material forming composition were produced. Since the substrate with an adhesive layer immediately after printing is automatically laminated by a printing machine, a weight of a predetermined weight (200 g) is placed on the top of the printed substrate with an adhesive layer for a predetermined time (1 hour). Then, tackiness (adhesiveness between substrates with adhesion layers) of each substrate with adhesion layers was evaluated. The tackiness was evaluated according to the following criteria. The results are also shown in Table 1.
A: Tackiness is not felt B: Tackiness is low, and the adhesion layer is easily peeled off even when it comes into contact with another substrate or plate making C: Tackiness is slightly strong, but the adhesion layer is in contact with another substrate or platemaking Even if it peels off (printing with a printing press is possible)
D: Tack property is strong, and when the adhesion layer comes into contact with another base material or plate making, it is difficult to print with a printing machine. In this embodiment, the above-described A to C are evaluated as having good tack property. did.

As shown in Table 1, the composition of the tackifier is in the range of about 27 to 40% by mass in the adhesion layer (solid content), and the mass ratio (B / A) to the acrylic resin is about 0 as described above. It can be seen that the adjustment can be made in the range of 3 to 0.6. Although not specifically shown, it has been confirmed that the mass ratio of the tackifier to the acrylic resin is preferably adjusted to be in the range of about 0.3 to 0.7. If the amount of the tackifier is too large, a transfer sheet with high adhesion between the adhesion layer and the substrate and the pattern layer can be obtained, but it is difficult to leave the substrates and the screen printing plate making while remaining attached to the adhesion layer. It is not preferable because of lack of properties. When the ratio of the tackifier is too small, the tackiness is suppressed, which is preferable, but the adhesiveness is too low, which is not preferable.
On the other hand, when the amount of the spherical inorganic particles is too small, a transfer sheet having excellent adhesion can be obtained, but the tackiness cannot be sufficiently suppressed. Therefore, when printing a pattern layer on a substrate with an adhesion layer, the adhesion layer and another substrate adhere to each other, or screen printing plate making adheres to the production efficiency. Therefore, it is not preferable. If the amount of the spherical inorganic particles is too large, the tackiness can be suppressed, but the adhesion is also lowered, which is not preferable. It was found that the composition of the spherical inorganic particles is preferably adjusted so that the ratio of the spherical inorganic particles to the adhesion layer (solid content) is in the range of about 4% by mass to 10% by mass.
In consideration of the balance between adhesion of the adhesion layer and low tackiness, the blending ratio of the tackifier and the spherical inorganic particles is about the mass ratio of the tackifier / spherical inorganic particles (B / C). However, if it is in the range of more than 2 and less than 11 (for example, 2.5 or more and 10 or less), it is considered that an adhesion layer in which more appropriate low tack property and adhesion students are compatible is obtained.

[Test Example 2]
An adhesive material-forming composition was prepared by dispersing an acrylic resin, a tackifier, and spherical inorganic particles in an organic solvent. As an acrylic resin, a transparent thermoplastic resin, manufactured by Mitsubishi Rayon Co., Ltd., Dianar BR (Mn: about 5 × 10 ⁴ , Tg: about 15 ° C., acid value: 1.0 mg / kg) Using. As the tackifier, Superester L (acid value: 18 or less, softening point VIS (mPa · s): 30,000 to 5,000) manufactured by Arakawa Chemical Industries, Ltd. was used. As the spherical inorganic particles, JA-244 (D50: 300 nm) manufactured by Jujo Chemical Co., Ltd., which is a spherical silica powder, was used. As the organic solvent, an isophorone-rubesso mixed solution was used. And after mixing these raw materials using a stirrer etc., the composition for adhesion | attachment material formation was obtained by performing a dispersion process with a 3 roll mill, for example. The composition of the acrylic resin, the tackifier, and the spherical inorganic particles in the adhesive material forming composition was as shown in Table 2 below. Also, the conditions for the dispersion treatment are the same, and a composition (a) whose dispersibility is improved by blending a dispersant and a composition (b) whose dispersibility is lowered without blending a dispersant. Prepared.

[transparency]
The composition (a) and the composition (b) prepared above were each applied to a glass substrate and dried to form adhesion layers (a) and (b), respectively, and visually observed. An observation image of the adhesion layer is shown in FIG. The dried film (a) obtained from the composition (a) in which the silica powder was sufficiently dispersed was colorless and transparent as observed visually. In addition, the characters prepared on the observation table could be observed through the dry film and the glass substrate, and the characters could be clearly confirmed without stagnation. On the other hand, the dry film (b) obtained from the composition (b) in which the dispersion of the silica powder was not sufficiently observed was cloudy when visually observed. In addition, for characters prepared on the observation table, the outline of the characters disappears through the dry film and the glass substrate, light scattering by silica particles occurs, and it can be confirmed that transparency is impaired. It was.
From this, in order to increase the transparency of the adhesion layer of the transfer sheet, it is possible to use fine transparent particles such as silica powder as spherical inorganic particles and to disperse the silica powder in the adhesion layer to a high degree. It turned out to be effective.

[Test Example 3]
(Sample 1)
An adhesive material-forming composition was prepared by dispersing an acrylic resin, a tackifier, and spherical inorganic particles in an organic solvent. As an acrylic resin, a transparent thermoplastic resin, manufactured by Mitsubishi Rayon Co., Ltd., Dianar BR (Mn: about 5 × 10 ⁴ , Tg: about 15 ° C., acid value: 1.0 mg / kg) Using. As the tackifier, Superester L (acid value: 18 or less, softening point VIS (mPa · s): 30,000 to 5,000) manufactured by Arakawa Chemical Industries, Ltd. was used. As the spherical inorganic particles, JA-244 (D50: 300 nm) manufactured by Jujo Chemical Co., Ltd., which is a spherical silica powder, was used. As the organic solvent, an isophorone-rubesso mixed solution was used. And after mixing these raw materials using the stirrer etc. in presence of additives, such as a dispersing agent, the composition for adhesion | attachment material formation was obtained by performing a dispersion process with a 3 roll mill, for example. The composition of the acrylic resin, the tackifier, and the spherical inorganic particles in the adhesive forming composition was as shown in Table 3 below.

  As a base material, a commercially available paper (thickness: 200 μm) coated with a water-soluble paste was prepared. On this base material, the adhesive material-forming composition prepared above was screen-printed and dried at room temperature to form an adhesive layer having a thickness of 10 to 15 μm. Next, a pattern layer having a thickness of 5 μm was screen-printed on the adhesion layer using a black ink (SG700 710 Black, manufactured by Seiko Advance Co., Ltd.) or the like. Then, a clear layer having a thickness of 8.5 μm was formed on the pattern layer using a resin having a crosslinked polyrotaxane structure (manufactured by Seiko Advance Co., Ltd., SRP-A medium). This obtained the transfer sheet (1) disclosed here.

This transfer sheet (1) is immersed in water, the transfer part consisting of the adhesive layer, the pattern layer, and the clear layer is lifted from the base material and collected from the water, and is attached to a test piece made of 200 mm × 70 mm ABS resin. And dried at room temperature. At the time of pasting, it is possible to adjust the precise pasting position and angle of the transfer portion on the test piece, and thereby, the ABS resin product was decorated with a pattern.
Next, with respect to the decoration by such a transfer sheet, the adhesiveness showing the characteristics of the adhesive layer characteristic of the transfer sheet disclosed herein, and additional properties such as weather resistance, hardness, gasoline resistance, and self-healing properties evaluated. The flexibility was evaluated using a transfer sheet before decoration. The results are shown in Table 4 below. The contents of the evaluation methods and the results shown in Table 4 are as follows.

[Adhesion] JIS K 5600-5-6: 1999 Adhesion was evaluated according to adhesion (cross-cut method). That is, by applying a cutter knife so that the blade is perpendicular to the surface of the transfer portion of the test piece prepared above, a grid-like cut at intervals of 1 mm is made at a depth reaching the substrate to the adhesion layer. One book was provided, and 100 grids were formed.
Cellophane tape (Nichiban Co., Ltd., plant cellophane tape 18 mm, CT405AP-18) cut to about 75 mm was firmly crimped with fingers in a direction parallel to the cuts on the grids formed in this way. Next, the end of the tape was peeled off at a 60 ° angle in 0.5 seconds to 1 second, and the cross-cut state was classified by comparison with a standard drawing. ) "Column. “Category” indicating adhesion and criteria for quality determination were the same as in the above-described adhesion evaluation.

[Flexibility] Flexibility was evaluated according to a test of JIS K 7161: 1994 tensile properties. That is, first, the transfer sheet was cut into a 10 mm × 30 mm rectangle and immersed in water to peel the transfer portion from the substrate of the transfer sheet to obtain a test piece. The test piece was placed on a tensile tester (Orientec Co., Ltd., Tensilon Universal Tester RTC-1210) and stretched until it broke at room temperature (25 ° C.) and a tensile rate of 100 mm / min. -Strain curves were obtained. From this stress-strain curve, elongation is based on the following equation: E = (L ₁ −L ₀ ) ÷ L ₀ × 100, L ₀ : First marked line interval, L ₁ : Marked line interval at cutting. The rate (E) was determined and the flexibility was evaluated. In the present embodiment, the case where the elongation was 120% or more was evaluated as ◯, and the case where the elongation was less than 120% was evaluated as x. The results are shown in the “flexibility” column of Table 4.

[Weather resistance] An accelerated weather resistance test was conducted using a sunshine carbon arc lamp type light resistance tester having the ability defined in JIS B 7753: 2007. Specifically, the color value of the transfer part of the test piece is measured before and after irradiating the sunshine carbon weather meter (Ci4000, manufactured by Atlas Co., Ltd.) to the transfer part (decorative surface) of the test piece prepared above. By calculating the color difference ΔE, the change in color tone due to accelerated exposure of the sunshine carbon arc lamp was evaluated. The color value is measured using a color difference meter (manufactured by Konica Minolta Co., Ltd., CR-5) according to the L ^* a ^* b ^* color system before exposure, after 500 hours exposure, and after 1000 hours exposure. Carried out. When measuring the color value, the test piece was removed from the testing machine and allowed to stand in a standard state for drying. The color difference ΔEn (color difference after n hours exposure) was determined by the following formula.
ΔE _n = (Δa ² + Δb ² + ΔL ² ) ^1/2
The measurement results of the color difference are shown in the column of “Weather resistance” in Table 4. In the present embodiment, the case where ΔE ₅₀₀ ≦ 1.5 and ΔE ₁₀₀₀ ≦ 3 was evaluated as having good weather resistance.

  [Hardness] JIS K 5600-5-4: 1999 Mechanical properties of the coating film-Scratch hardness (pencil method), the hardness of the transfer part of the test piece was measured. Specifically, a pencil core with a specified size, shape and hardness is pressed against the surface of the transfer part at an angle of 45 ° and a load of 750 g, and moved to scratch the lowest pencil hardness at which scratches or defects occur. The measurement results are shown in the column “Hardness” in Table 4. In this embodiment, when the scratch hardness is H or higher, the hardness is evaluated as good.

[Gasoline resistance]: The test piece was subjected to the following (1) gasoline drop test and (2) gasoline immersion test. In any of the tests, the surface of the transfer part of the test piece was significantly discolored, blurred, or patterned. If no smearing / unevenness of color, unevenness, wrinkles, peeling, cracking, scratches, etc. are observed, the gasoline resistance is judged to be good, and the above events were observed in any of the tests. The gasoline resistance was judged to be poor. The measurement results are shown in the column of “Gasoline resistance” in Table 4.
(1) Gasoline dripping test: The test piece is tilted at 45 °, and gasoline (white gasoline) is dropped 10 times at 1 minute intervals on the end of the transfer part. After leaving for 1 minute, the gasoline is wiped off and left for 168 hours. did.
(2) Gasoline immersion test: The test piece was immersed in commercially available gasoline so that the surface was hidden about half, immersed for 0.5 hour, taken out, and allowed to stand for 168 hours.

[Self-healing property] A wire having a diameter of about 0.8 mm was pressed against the surface of the transfer part of the test piece with a load of 200 g and moved to make a scratch having a length of 30 mm. Immediately after the scratch was applied and after standing for 1 hour, this wound was observed with a surface roughness measuring instrument (Tokyo Seimitsu Co., Ltd., Surfcom 480B) to determine the maximum scratch depth. And the wound restoration rate was computed based on the following formula, and self-repair property was evaluated. In the present embodiment, when the self-repairing property at which scratches cannot be visually confirmed is 90% or more, the self-repairing property is good (◯), and when it is less than 90%, the self-recovering property is poor (×). Evaluated that there was. The measurement results are shown in the column of “self-repairability” in Table 4.
Scratch restoration rate (%) = maximum wound depth 1 hour after wound application / maximum wound depth immediately after wound application × 100

(Sample 2)
Instead of the acrylic resin in the composition for forming an adhesive material of Sample 1, an adhesive layer was formed using an epoxy resin composition containing a thermosetting epoxy resin as a main component. Further, in place of the resin having the crosslinked polyrotaxane structure of Sample 1 above, a clear layer is formed using a widely used urethane resin-based coating material (Seiko Advance Co., Ltd., 7300 overcoat clear), The transfer sheet (2) was obtained under the same conditions as Sample 1. Then, in the same manner as Sample 1, various characteristics of the transfer sheet (2) were evaluated. That is, the above evaluation was performed in a state where the clear layer was not cured by heating. The results are also shown in Table 4.

(Sample 3)
Various characteristics were evaluated in the same manner as in Sample 1 using the transfer sheet (2) obtained in Sample 2 above. However, in Sample 3, when the transfer portion was attached to a test piece made of ABS resin, the transfer portion was heated to 80 ° C. (that is, thermally bonded) to cure the clear layer. Table 4 shows the results of the decorations thus applied.

  As shown in Table 4, in the transfer sheet of Sample 1, an acrylic resin was used as the resin component for forming the adhesion layer, so that the transfer sheet was not required to be heated when the transfer sheet was attached to an object to be decorated. It was confirmed that can be attached with good adhesion. In addition, since the acrylic resin has an appropriate flexibility even after curing at room temperature, the transfer sheet itself of the sample 1 has flexibility and can be attached with good workability. It could be confirmed. Although not specifically shown in the present embodiment, the present inventor uses the acrylic resin as a resin component for forming the adhesion layer, so that, for example, flexibility that can follow a three-dimensional curved surface, an uneven surface, or the like is provided. It has also been confirmed that a transfer sheet having this can be realized. In addition, since it can be attached with high adhesion, the durability against external factors such as hardness and gasoline resistance can be increased.

On the other hand, as shown in Sample 2, when an epoxy resin was used as the resin component for forming the adhesion layer, the adhesion of the adhesion layer could not be expressed unless heating was performed at the time of attachment. It was also found that the durability against external factors such as gasoline resistance is lowered when good adhesion is not expressed in the adhesion layer and good adhesion cannot be performed. In addition, since the urethane layer was used for the clear layer, sufficient surface hardness could not be realized without heating.
As shown in Sample 3, even when an epoxy resin was used as the resin component for forming the adhesion layer, it could be adhered with good adhesion by heating at the time of application. However, it has been confirmed that the transfer sheet paste destination (work) is required to have heat resistance, and the pasting work becomes complicated. In addition, since the epoxy resin causes excessive curing of the adhesive layer by heating, it does not appear in the results of Table 4 above. However, once the transfer sheet of Sample 3 is heated at the time of application, it is applied again even immediately after application. I couldn't.

  The clear layer is required to have a role of providing gloss to the transfer portion and protecting the pattern layer. As shown in Sample 1 and Sample 3 in Table 4, whether a urethane resin, which is a conventional standard clear layer resin, is used, or a resin having self-healing properties such as a polyrotaxane resin is used, a moderate gloss It was confirmed that such a function can be sufficiently provided. In addition, even if some scratches are imparted to the decoration of the transfer sheet by using a resin having a self-repairing property such as a polyrotaxane resin as a resin component forming the clear layer as in Sample 1. It was confirmed that such scratches could be repaired without special treatment and the design of the pattern layer could be maintained at a high level. The decorative material such as a transfer sheet is required to have durability that can withstand the use environment of the decorated object after decoration in addition to workability at the time of manufacture and use (transfer). For example, a helmet such as a motorcycle is more preferably provided with the above adhesion, flexibility, weather resistance, hardness, gasoline resistance, and self-healing properties. Therefore, it was confirmed that the use of the transfer sheet disclosed herein is preferable in order to easily perform decoration in such applications without selecting the material of the base material.

[Test Example 4]
Using the transfer sheets (1) and (2) prepared in Samples 1 and 2, the tensile properties were evaluated. That is, each transfer sheet was cut into a rectangle having a width of 10 mm and a length of 20 mm, and the transfer parts (1) and (2) from which the substrate was peeled were used as test pieces. Based on JIS K7127, the specimen was stretched at room temperature (25 ° C.) with a precision universal testing machine (Orientec Co., Ltd., Tensilon universal testing machine RTC-1210) at a tensile speed of 10 mm / min. A stress-strain curve was recorded. The obtained stress-strain curve is shown in FIG. 3A and the initial strain region is shown in FIG. 3B. The slope of the rising edge of the curve in the initial strain region was calculated by linear regression between two points (ε ₁ , ε ₂ ) of strain amounts ε ₁ = 0.0005 and ε ₂ = 0.0025.

As for the transfer parts (1) and (2), it was confirmed that the elongation rate exceeded 250%, indicating good stretchability. Such stretchability can be said to be easy to deform the transfer portion along the curved surface, and to easily apply the transfer portion along the surface shape of the object to be decorated, that is, to have high curved surface followability.
Further, the rising slope of the stress-strain curve was 0.14 for the transfer portion (1) and 0.13 for the transfer portion (2), both of which were good values. This rising inclination reflects the degree of stiffness of the transfer portion, and can suppress the occurrence of floating and wrinkles after pasting, and the same effect can be obtained even in actual pasting. . That is, in place of the conventional transfer sheet, the transfer sheet disclosed here does not require a heating effect at the time of pasting, and it may be just pasted, but in addition to adhesion, stretchability, followability, etc. It was confirmed that the paste was also excellent in sticking property.

  In addition, about the transfer part (2), it was examined whether the heating at the time of affixing could be skipped by hardening beforehand. However, the transfer part (2) in which both the adhesion layer made of epoxy resin and the clear layer made of urethane resin were previously heat-cured was broken at an elongation of several% in the tensile test. That is, it is expected that a transfer sheet using a conventional thermosetting resin does not have stretchability and cannot follow a curved surface. Therefore, for example, it can be said that it is difficult to decorate a curved surface using such a transfer sheet.

From the above, the transfer sheet disclosed herein can be suitably manufactured by printing such as screen printing, and can be securely attached to the object to be decorated without requiring heating. In addition, since the transfer sheet has a good balance between the adhesiveness of the adhesive layer and the low tackiness, it can be prevented from adhering to the printing plate making and the like, and has excellent adhesiveness to the decoration. It has special characteristics. Further, such a transfer sheet is provided with excellent workability for maintaining sticking because it has an appropriate stiffness and is excellent in followability to a curved surface.
Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

DESCRIPTION OF SYMBOLS 1 Transfer sheet 10 Base material 20 Adhesion layer 30 Picture layer 40 Clear layer

Claims (9)

A substrate;
A peelable adhesion layer provided on the substrate;
A pattern layer printed on the adhesion layer;
A clear layer provided on the pattern layer;
With
The pattern layer is provided in a region excluding a peripheral portion of the adhesion layer,
The clear layer is provided on the peripheral edge of the pattern layer and the adhesion layer,
The adhesion layer includes an acrylic resin, a tackifier, and spherical inorganic particles having a refractive index of 1.2 to 1.55, and is transparent with a light transmittance of 70% or more at a wavelength of 550 nm. Transfer sheet.   The transfer sheet according to claim 1, wherein a ratio of the spherical inorganic particles in the adhesion layer is 1% by mass to 20% by mass.   The transfer sheet according to claim 1 or 2, wherein a ratio B / C of a mass (B) of the tackifier to a mass (C) of the spherical inorganic particles is 1 to 10.   The transfer sheet according to claim 1, wherein the spherical inorganic particles are spherical silica particles having an average particle diameter of 5 nm to 1000 nm. The transfer sheet according to claim 1, wherein the acrylic resin has a number average molecular weight of 1.5 × 10 ⁴ to 15 × 10 ⁴ .   The transfer sheet according to any one of claims 1 to 5, wherein an elongation percentage of the post-peeling transfer sheet from which the substrate has been peeled is 120% or more.   The transfer sheet according to any one of claims 1 to 6, wherein the clear layer is composed of a polymer material containing a crosslinked polyrotaxane structure.   The transfer sheet according to any one of claims 1 to 7, wherein a water-soluble paste material is provided on a surface of the substrate on which the adhesion layer is provided. The transfer sheet according to claim 8, wherein the base material is composed of a fiber assembly in which fibers are aggregated.