JP3245624B2 - Thermal transfer recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording medium, and more particularly to a thermal transfer recording medium which is used for display on a display label such as clothing or on clothing itself. The present invention relates to a thermal transfer recording medium in which the transferred image is obtained as an image (including characters, symbols, etc.) having excellent dry cleaning resistance, soaping resistance (water washing resistance), etc. (hereinafter sometimes referred to as "cleaning resistance"). is there.

[0002]

2. Description of the Related Art Many thermal transfer sheets that can be used for clothing have been proposed. Particularly, in the case where the ink layer of the thermal transfer sheet is formed on the object to be transferred in a pattern, research on improving the cleaning resistance of the image formed on the object to be transferred has been energetically conducted. The main factor relates to the fixing property of the binder resin constituting the thermal transfer layer. For example, studies using the following binder resins have been published. (1) polyamide resin and amorphous polyester resin and / or
Or using an epoxy resin (Japanese Patent Application Laid-Open No. 61-24459).
No. 3). (2) a glass transition temperature of 40 ° C. or higher and a number average molecular weight of 10,
An amorphous polyester resin having a glass transition temperature of 50 to 80 ° C. and a number average molecular weight of 5,000 or less and containing a bisphenol component is preferably used (Japanese Patent Laid-Open No. 62-13384). (3) Use of a polymerized fatty acid-based polyamide resin (JP-A-6
2-66991). (4) Use of at least one of vinyl chloride-vinyl acetate copolymer resin, acrylate-vinyl acetate copolymer resin, methacrylate-vinyl acetate copolymer resin or vinyl acetate resin (JP-A-63-56490)
issue). (5) Using butyral resin (JP-A-63-8278)
No. 6). (6) A fatty acid amide or fatty acid imide having a melting point of 120 ° C. or more and a polyamide resin or a vinyl resin having a melting point of 100 ° C. or more are contained (JP-A-63-179791).

However, an image formed on a transfer-receiving body with a thermal transfer ink in which a coloring agent is dispersed in such a binder resin has a cleaning solvent (water, hot water,
Since a substance that is soluble in 1,1,1-trichloroethane, perchrene, naphtha, etc.) is used, the fact is that cleaning resistance is not sufficiently satisfied.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a thermal transfer recording medium capable of forming a color transfer image with excellent transferability from an ink layer to a transfer receiving body and improved cleaning resistance. The subject.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, in a thermal transfer recording medium in which an ink layer mainly containing a colorant and a resin binder is provided on a support, (A) the colorant is (a) copper phthalocyanine and halogen Copper phthalocyanine pigment

(B) Azo pigments represented by the following general formula [1]

Embedded image [Wherein, R ₁ , R ₂ and R ₃ may be the same or different, and H or C _n H _{2n + 1} (where n = 1 to 3)
And X ₁ , X ₂ , X ₃ and X ₄ may be the same or different and are H, Cl or Br]

(C) azo pigments represented by the following general formula [2]

Embedded image Wherein X ₁ , X ₂ and X ₃ may be the same or different and are H, Cl or Br.

(D) An azo pigment represented by the following general formula [3]

Embedded image [Wherein, X ₁ , X ₂ , X ₃ and X ₄ may be the same or different, and each is C _n H _{2n + 1} (where n = 1 to 3), or is selected from H, Cl and Br. Selected atom)

(E) An azo pigment represented by the following general formula [4].

Embedded image [Wherein, R ₁ , R ₂ and R ₃ may be the same or different, and H or C _n H _{2n + 1} (where n = 1 to 3)
Wherein X ₁ , X ₂ , X ₃ and X ₄ may be the same or different and are each H, Cl or Br], and at least one pigment selected from the group consisting of

(B) The ratio of the amount of the colorant to the amount of the resin binder in the ink layer is determined by calculating the bulk (reciprocal of the density) calculated from the powder bulk density of the colorant according to the DIN 53194 method as A (cm ³ / cm).
g), the bulk (reciprocal of the density) of the resin binder is B (cm ³ /
g), when the weight fractions of the colorant and the resin binder in the ink layer are x and y, respectively, a value satisfying the following formula (Axx) / (Bxy) = 3 to 10 A thermal transfer recording medium is provided.

The thermal transfer recording medium of the present invention has a thermal transfer ink layer formed on a support directly or via a release layer, or via an undercoat layer and a release layer provided thereon. . The support is a plastic film having a thickness of about 3 to 10 μm, for example, a polyester film, a polycarbonate film, a polyimide film, an aromatic polyamide film, a polyetheretherketone film, a polysulfone film, or the like. The adhesion amount of the thermal transfer ink layer is 0.1 to
3.0 g / m ² preferably at about 0.5 to 2.0 g / m ^2, and is formed as a main component a colorant and a resin binder which is insoluble in the cleaning solvent.

The colorant used in the present invention must have resistance to a cleaning solvent and alkali, and must have heat resistance and light resistance. Those having various colors are selected. Colorants suitable for this purpose include the following pigments. (1) Blue / green colorants: Copper phthalocyanine pigments and halogenated phthalocyanine pigments, especially chlorinated phthalocyanine pigments. These pigments are excellent not only in chemical resistance but also in weather resistance including heat resistance and light resistance. (2) Red / brown colorants: water-insoluble azo pigments represented by the general formulas [1], [2] and [4]. (3) Yellow colorant: a water-insoluble azo pigment represented by the general formula [3].

In the present invention, in order to obtain a high quality product, it is important to use the above-mentioned specific colorant in the ink layer and to specify the quantitative ratio of the colorant to the resin binder. It is. That is, the bulk (reciprocal of the density) calculated from the powder bulk density of the colorant according to the DIN 53194 method
Is A (cm ³ / g), the bulk (reciprocal of the density) of the resin binder is B (cm ³ / g), and the weight fractions of the colorant and the resin binder in the ink layer are x and y, respectively. It is necessary that the value satisfy the following expression (A × x) / (B × y) = 3 to 10. Even if the above-mentioned specific colorant is selected, if this ratio is larger than 10, the ink layer tends to fall off from the support, and the formed image has insufficient mechanical properties such as abrasion resistance. . On the other hand, when this ratio is smaller than 3, the cohesive force of the ink layer increases, and the thermal sensitivity decreases. As a result, a so-called "tomochi phenomenon" (for example, a phenomenon in which a portion surrounded by a line on the left side of the character "" is transferred by being surrounded by the surrounding line) occurs. In the present invention, while using the specific colorant described above, by specifying the quantitative ratio of the colorant and the resin binder, it has various colors with good cleaning resistance, and excellent heat sensitivity, and It is possible to obtain a high-quality thermal transfer recording medium free from the "tomo phenomenon".

The resin binder used in the ink layer has a solubility parameter of 9.6 to 14.2 (cal ·
cm ^-3 ) ** 1/2 (** 1/2 means the 0.5 power; the same applies hereinafter). This solubility parameter value (SP value) can be calculated by the following equation. δ ² = E / V [where δ is a solubility parameter and (cal · cm
^-3 ) ** 1/2 and E is the cohesive energy (ca
1 / mol) and V represents molecular volume (cm ³ / mol)]

Examples of the polymer for a resin binder having a solubility parameter in the above range include polyvinyl butyral, polyvinyl chloride, polyvinylidene chloride, vinylidene chloride-acrylonitrile copolymer, fluoropolymer, polyamide, polyethylene, and the like. Polypropylene, polyester, N
BR, ethylene-vinyl acetate copolymer, polyacrylonitrile, polyurethane, vinyl chloride-vinyl acetate copolymer. Among these polymers, as a binder for the ink layer, a melting point (by the DSC method) or a softening point (V
A polymer having an ICAT method of 80 to 150 ° C., and among them, a polyamide resin is excellent in cleaning solvent resistance, heat transferability, and iron resistance. Melting point (DS
C) or softening point (by VICAT method) is 80
Examples of the polyamide resin at a temperature of up to 150 ° C. include the following.

(1) Binary copolymer

[Table 1] (2) Terpolymer (6/66/610 nylon) (mp 150 ° C) (6/66/12 nylon) (mp 120 ° C) (6/66/12 nylon) (m .P.100 ° C.)

In the present invention, if necessary, other optional substances (for example, stabilizer, resin, etc.) may be contained in the ink layer for the purpose of improving the sensitivity, preventing the ink layer from falling off the support, and improving the dispersibility. , Wax, surfactant, etc.), but the amount should be minimized so as not to reduce the cleaning resistance, alkali resistance, etc. of the ink layer. The material constituting the ink layer is dispersed in an appropriate solvent or is melt-dispersed and applied as a uniform liquid on a support.

An optional release layer provided between the support and the ink layer improves the releasability between the support and the ink layer (including the island-shaped ink) during thermal printing. It is sufficient that the material is heated so as to be melted and turned into a low-viscosity liquid, and the layer is easily cut near the interface between the heated portion and the non-heated portion. Therefore, as a main component of the release layer, a wax-like substance that is hard at room temperature and melts when heated is preferably used. Such wax-like substances include, for example, beeswax, carnauba wax, whale wax,
Natural waxes such as wood wax, candelilla wax, rice bran wax, and montan wax; synthetic waxes such as paraffin wax, microcrystalline wax, oxidized wax, ozokerite, ceresin, ester wax, and polyethylene wax are preferably used. Higher fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, froinic acid, and behenic acid; higher alcohols such as stearyl alcohol and behenyl alcohol; esters such as fatty acid esters of sorbitan; amides such as stearinamide and oleinamide No. In addition, rubbers such as isoprene rubber, butadiene rubber, ethylene propylene rubber, butyl rubber, and nitrile rubber may be added to impart elasticity to the release layer and improve the adhesion between the ink sheet and the transfer target. And
A resin such as an ethylene-vinyl acetate copolymer or an ethylene-ethyl acrylate copolymer may be added in order to impart adhesiveness to the release layer and prevent the release layer from falling off.
The adhesion amount of the release layer is 0.5 to 8 g / m ^2, preferably 1 to 5 g / m ^2.
g / m ² .

If necessary, the undercoat layer provided between the support and the release layer is often used when the surface area is increased by, for example, providing irregularities on the surface. As the surface area increases, the adhesion area between the release layer and the undercoat layer increases accordingly, which not only increases the adhesive strength between the two layers, but also has the effect of making the release layer easier to cut during thermal transfer. Such a concavo-convex shape can be obtained by binding fine powder of a metal oxide to the surface of a support with a binder. In this case, the material of the metal oxide fine particles includes silica, aluminum oxide, magnesia, titanium oxide, zinc oxide, and the like, and the particle size is 0.1 to 3 μm.
The degree is preferred. As the binder here, a thermoplastic resin such as vinyl chloride-vinyl acetate copolymer, ethyl cellulose and the like, a thermosetting resin such as an unsaturated polyester resin, an epoxy resin and the like can be used. The ratio (weight ratio) of these metal oxide fine particles to the binder is desirably 1:10 to 5: 1. The amount of adhesion of the undercoat layer is 0.1 to 3.0 g.
/ M ² , preferably 0.5 to 2.0 g / m ² .

On the other hand, an object to be transferred is one in which a receiving layer mainly composed of a resin having resistance to a cleaning solvent or an alkali is provided on a woven or nonwoven fabric-like support.
As the resin used for such a receiving layer, the same polymer as the resin binder used for the above-mentioned ink layer can be used. Among them, melting point (by DSC method) or softening point (VIC
A thermoplastic resin having an A.T. method of 150 to 260 [deg.] C. is preferable. Among them, a polyamide resin having good cleaning agent resistance and iron resistance is excellent, and this resin has a good effect on thermal transferability. Melting point or softening point is 150-26
Examples of the polyamide resin at 0 ° C. include those represented by the following structural formula.

[0021]

[Table 2] In addition, nylon 6, nylon 66, nylon 610, and the like can also be suitably used.

In addition to these substances, the receiving layer contains a white pigment such as titanium oxide, silica, alumina, magnesia, zinc oxide, calcium carbonate, etc. in order to improve the whiteness or thermal transferability of the transfer object. Is also good. Further, a plasticizer may be added for giving flexibility. The receiving layer material is used by dissolving or dispersing it in a suitable solvent, or by dissolving and dispersing. Adhesion amount of the receiving layer is 1 to 30 g / m ^2, preferably at about 3 to 20 g / m ² (indicates the amount of deposition on the surface of the adhesion amount, where deposition amount and the back surface of the impregnated on a support Minutes are not included). The above-mentioned woven fabric or non-woven fabric is used as the support of the transferred body. In particular, artificial fibers such as rayon, Bemberg, acetate, nylon, and polyester, or natural fibers such as cotton and silk, or blended fibers thereof Woven fabrics or nonwoven fabrics thereof are preferably used.

In the thermal transfer recording medium and the object to be transferred according to the present invention, the solubility parameter (SP value) of the resin binder of the ink layer and the resin of the receiving layer is in the range of 9.6 to 14.2. Thereby, the soaping resistance can be improved. Further, by setting the melting point or softening point of the resin binder of the ink layer to 80 to 150 ° C., thermal transferability can be improved. Furthermore, by setting the melting point of the resin of the receiving layer to 150 to 260 ° C., the resin of the ink layer and the resin of the receiving layer are well integrated by heat when heat is applied, an image having good fixability is obtained, and the iron resistance is improved. (The iron is often applied at about 150 ° C., but the resin used for the receiving layer and the ink layer of the present invention has a very high melt viscosity. Will not be disturbed). It is effective to use the same type of resin for good integration of the ink layer and the receiving layer.

[0024]

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. In these examples, parts indicate parts by weight.

Reference Example 1, Examples 2 to 7 (A) Preparation of ink dispersion ( Reference Example 1 ) Ink liquid 1: 50 parts of carbon black (black pigment) (reciprocal of bulk density 4.44 cm ³ / g) 6 / 66/12 nylon (reciprocal of density 0.88 cm ³ / g) 50 parts Methanol 900 parts (Axx / Bxy = 4.44 × 0.5 / 0.88 × 0.5 = 5.1) (Example 2) Ink liquid 2: Copper phthalocyanine (blue pigment) 60 parts (reciprocal of bulk density 3.72 cm ³ / g) 6/66/12 nylon 40 parts Methanol 900 parts (Axx / Bxy = 3) 0.72 × 0.6 / 0.88 × 0.4 = 6.3) (Example 3) Ink liquid 3: 71 parts of chlorinated copper phthalocyanine (green pigment) (reciprocal of bulk density 3.50 cm ³ / g) 6/66/12 Nylon 29 parts Methanol 900 parts (Axx / Bxy = (3.50 × 0.71 / 0.88 × 0.29 = 9.7)

Example 4 Ink Liquid 4: Red Azo Pigment of the Following Structural Formula (Inverse of Bulk Density 3.93 cm ³ / g) 55 parts 6/66/12 nylon 45 parts methanol 900 parts (Axx / Bxy = 3.93 × 0.55 / 0.88 × 0.45 = 5.5)

Embedded image

(Example 5) Ink liquid 5: Red azo pigment having the following structural formula (reverse number of bulk density: 4.02 cm ³ / g) 55 parts 6/66/12 nylon 45 parts Methanol 900 parts

Embedded image (Axx / Bxy = 4.02 x 0.55 / 0.88 x 0.45 = 5.6)

(Example 6) Ink liquid 6: Brown azo pigment having the following structural formula (the reciprocal of bulk density: 4.55 cm ³ / g) 40 parts 6/66/12 nylon 60 parts Methanol 900 parts (Axx / B) × y = 4.55 × 0.4 / 0.88 × 0.6 = 3.5)

Embedded image

(Example 7) Ink liquid 7: Yellow azo pigment having the following structural formula (the reciprocal of bulk density 3.76 cm ³ / g) 55 parts 6/66/12 nylon 45 parts Methanol 900 parts

Embedded image (Axx / Bxy = 3.76 × 0.55 / 0.88 × 0.45 = 5.2) These ink liquids 1 to 7 were dispersed for 10 hours using a ball mill, and methanol was used as a dispersion medium. Ink dispersions 1 to 7
Was prepared.

(B) Preparation of thermal transfer recording medium A polyester film having a thickness of 4.5 μm was used as a support, and a mixture of the following substances was dispersed on one side of the support by a ball mill for 10 hours. The coating was applied onto the body so as to have a dry adhesion amount of 1 g / m ² and dried to form a release layer on the support. Carnauba wax 9 parts Ethylene / vinyl acetate copolymer 1 part Toluene 90 parts On the other hand, a 1 wt% toluene solution of silicone rubber as a lubricity protective layer on the surface of the support opposite to the release layer is 0.1 g / m ² and dried. Next, the ink dispersions 1 to 7 on the release layer of the support,
Apply each so that the dry adhesion amount is 1 g / cm ² ,
Reference Example 1 in which the ink layer was dried and provided on the release layer
The sheet-like thermal transfer recording media of Examples 2 to 7 were prepared.

Comparative Examples 1 to 5 (A) Preparation of Ink Dispersion (Comparative Example 1) Ink Liquid 8: Copper phthalocyanine (blue pigment) 40 parts 6/66/12 nylon 60 parts Methanol 900 parts (Axx / B × y = 2.8) (Comparative Example 2) Ink Liquid 9: The same brown azo pigment as ink liquid 6 70 parts 6/66/12 nylon 30 parts Methanol 900 parts (Axx / Bxy = 12.1) (Comparative Example 3) Ink liquid 10: Quinacridone red pigment (reciprocal of bulk density 4.15 cm ³ / g) 50 parts 6/66/12 nylon 50 parts Methanol 900 parts (Axx / Bxy = 4.7)

(Comparative Example 4) Ink Liquid 11: Pigment Red 49: 1 using the red azo pigment of Ink Liquid 4
(Ink liquid prepared exactly as in Example 4 except that the reciprocal of the bulk density was 2.80 cm ³ / g). (Axx / Bxy = (2.80 × 0.55 / 0.88 × 0.45 = 3.9)) (Comparative Example 5) Ink liquid 12: Pigment blue 1 of ink liquid 2 was used. Example 2 except that the reciprocal of the bulk density was changed to 3.64 cm ³ / g).
Ink liquid created exactly as above. (Axx / Bxy = 3.64 × 0.6 / 0.88 × 0.4 = 6.2) These ink liquids 8 to 12 were used in the same manner as in Reference Example 1 and Examples 2 to 7. To prepare ink dispersions 8 to 12 using methanol as a dispersion medium.

(B) Preparation of Thermal Transfer Recording Medium The same support as used in Reference Example 1, Examples 2 to 7,
Using the ink dispersions 8 to 12 prepared in Comparative Examples 1 to 5, in the same manner as in Reference Example 1 and Examples 2 to 7, the sheet shape of Comparative Examples 1 to 5 in which the ink layer was provided on the release layer A thermal transfer recording medium was prepared.

[Test Example] Using the thermal transfer recording media of Reference Example 1, Examples 2 to 7 and Comparative Examples 1 to 5, thermal transfer to a transfer target was performed. As the transfer object, a 30 μm thick nylon taffeta having a thickness of 100 μm
One coated with a wet nylon (nylon 6) film of μm was used. Thermal transfer is a commercially available thermal transfer printer (manufactured by Tohoku Ricoh Co., Ltd., line type, head applied energy 10 to 27 mj
/ Mm ² ), an appropriate printing energy (sensitivity) was determined, a transfer image was formed on the transfer object, and the following test was performed using the transfer object having the transfer image.
Table 3 shows the results.

(A) Soaping resistance test: JIS L
= 0844 According to the standard of A-3. (B) Dry cleaning resistance test: JIS L-0
860 standard. (However, the solvent was 1,1,1-trichloroethane and the temperature was 25 ° C.) (Decision) ：: Image did not drop at all ○: Image hardly dropped △: Image slightly dropped ×: Image dropped (C) Iron resistance test: The image portion was rubbed 10 times with an iron set at 150 ° C. with a force of 15 g / cm ² ,
Disturbance of the image was judged with the naked eye. (Judgment) ◎: No image distortion at all ○: Almost no image distortion △: Image is slightly distorted ×: Image is severely distorted

[0036]

[Table 3]

As is clear from the results in Table 3, the specific colorant according to the present invention was used, and the formula (Axx) / (Bx
y) The ink layers of Reference Example 1 and Examples 2 to 7 satisfying 3 to 10 exhibit excellent soaping resistance and dry cleaning resistance under the same thermal transfer conditions, and also have extremely excellent iron resistance. On the other hand, when the value of the above formula is smaller than 3 or larger than 10 even when the coloring agent specified in the present invention is used (Comparative Examples 1 and 2), the soaping resistance is deteriorated or the “tomochi phenomenon” occurs. Therefore, satisfactory results cannot be obtained. Further, when the coloring agent specified in the present invention is not used (Comparative Examples 3 to 5), even if the value of the above formula is 3 to
Even if it is within the appropriate value of 10, the soaping resistance is greatly degraded, and other characteristics also tend to be degraded, indicating that satisfactory results cannot be obtained.

[0038]

The thermal transfer recording medium of the present invention is characterized in that the transferred image has extremely excellent soaping resistance, dry cleaning resistance and ironing resistance, and can be used as a display label for clothing and the like, as well as for displaying the clothing itself. It is also advantageously applied to applications such as use.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-83893 (JP, A) JP-A-2-214696 (JP, A) JP-A-3-213395 (JP, A) JP-A-3- 251491 (JP, A) JP-A-4-347688 (JP, A) JP-A-62-53882 (JP, A) JP-A-62-53891 (JP, A) JP-A-3-79683 (JP, A) JP-A-64-55285 (JP, A) JP-A-63-62787 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/38-5/40 CAPLUS (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. A thermal transfer recording medium comprising a support and an ink layer containing a colorant and a resin binder as main components, wherein (A) the colorant comprises: (a) a copper phthalocyanine-based and halogenated Copper phthalocyanine pigment (b) Azo pigment represented by the following general formula [1] [Wherein, R ₁ , R ₂ and R ₃ may be the same or different, and H or C _n H _{2n + 1} (where n = 1 to 3)
And X ₁ , X ₂ , X ₃ and X ₄ may be the same or different and are each H, Cl or Br.) (C) Azo pigment represented by the following general formula [2] ] Wherein X ₁ , X ₂ and X ₃ may be the same or different and are each H, Cl or Br. (D) An azo pigment represented by the following general formula [3] [Wherein, X ₁ , X ₂ , X ₃ and X ₄ may be the same or different, and each is C _n H _{2n + 1} (where n = 1 to 3), or is selected from H, Cl and Br. (E) an azo pigment represented by the following general formula [4]: [Wherein, R ₁ , R ₂ and R ₃ may be the same or different, and H or C _n H _{2n + 1} (where n = 1 to 3)
And X ₁ , X ₂ , X ₃ and X ₄ may be the same or different and each is H, Cl or Br], and at least one pigment selected from the group consisting of: The ratio of the amount of the colorant to the resin binder in the layer is A (cm ³ / g), the bulk (reciprocal of the density) calculated from the powder bulk density of the colorant according to DIN 53194, and the bulk of the resin binder. When (reciprocal of the density) is B (cm ³ / g) and the weight fractions of the colorant and the resin binder in the ink layer are x and y, respectively, the following formula (Axx) / (Bx y) = 3-10, a thermal transfer recording medium characterized by the following value: 2. The resin binder has a melting point (DSC method) of 80 to 80.
The thermal transfer recording medium according to claim 1, wherein the thermal transfer recording medium is a polyamide at 150 ° C.