JP3085590B2 - Thermal transfer receiving sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer receiving sheet, and more particularly, to a thermal transfer receiving sheet excellent in sheet transportability.

[0002]

2. Description of the Related Art A thermal transfer method, in which a thermal transfer sheet and an image receiving sheet are combined and a desired image is transferred to an image receiving surface by heat supplied from a thermal head in response to an electric signal, is performed by a relatively compact printer. Is now attracting attention because it can be printed.
In printing, the ink sheet is usually supplied in a roll state, but the thermal transfer receiving sheet is generally supplied in a sheet form. On the thermal transfer receiving sheet, synthetic paper or polyester film having a smooth surface is preferably used in order to obtain good printing and images.

[0003]

However, the thermal transfer receiving sheet mainly composed of a synthetic resin such as synthetic paper or polyester film has high chargeability and insufficient lubrication, so that it cannot be used in a printer. Double feeding, paper jams, etc. occur during paper feeding and discharging, which often hinders running performance. If the lubricity is poor, the surface of the image may be damaged when the front and back surfaces are rubbed. For this reason, a method of applying an antistatic agent to the back surface of the thermal transfer receiving sheet (JP-A-2-231192, JP-A-2-225584) or a method of applying a resin having lubricity (JP-A-63-194982) is adopted. Have been. However, the use of an antistatic agent as described above results in poor lubricity.Also, even if a methyl methacrylate resin is used as the resin having lubricity, these resins have some lubricity but do not have antistatic properties. The method alone was not enough. The present invention solves the conventional problems as described above, and simultaneously satisfies antistatic properties and lubricity,
It is an object of the present invention to provide a thermal transfer receiving sheet which is less likely to cause double feeding and paper jam at the time of paper feeding and discharging and has good running properties.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have solved the above-mentioned problems. That is, the present invention relates to a thermal transfer receiving sheet provided with an image receiving layer capable of receiving a thermally transferred image on the surface of a sheet-like substrate, wherein a cationic monomer unit ( a) 15 to 60% by weight, hydrophobic monomer unit (b) 30 to 84.9% by weight, and general formula (I)

[0005]

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(Wherein R ₁ represents an alkyl group having 1 to 10 carbon atoms which may be the same or different, or a phenyl group, and n represents an integer of 5 or more). A) a thermal transfer receiving sheet provided with an antistatic lubricating layer containing a cationic copolymer consisting of 0.1 to 20% by weight as a main component;

Hereinafter, the present invention will be described in more detail.
The thermal transfer receiving sheet of the present invention generally has an image receiving layer on the surface of a sheet-like substrate and an antistatic lubricating layer on the back.

(Sheet-like substrate) The sheet-like substrate of the thermal transfer receiving sheet that can be used in the present invention is not particularly limited, but is a synthetic paper of a biaxially stretched film mainly composed of a polyolefin and an inorganic material, a polyester film and the like. Plastic films, laminated sheets obtained by combining them, or those obtained by laminating these with various kinds of paper and the like are suitably used. The thickness of the sheet substrate is 2
0 to 250 μm is preferred.

(Image-Receiving Layer) The image-receiving layer which can be used in the present invention has, on the surface thereof, a layer mainly composed of a resin which receives a dye transferred from a thermal transfer sheet in the case of dye sublimation type thermal transfer. Resins that can be used as this layer include, for example, saturated polyester resins, acrylic resins, vinyl chloride / vinyl acetate copolymer resins, polyamide resins, and the like, and are usually coated with 2 to 20 μm. In addition, in the case of the ink fusion thermal transfer, the image receiving layer may not be particularly provided,
In order to improve the adhesion to the ink and the like, it is preferable to provide a layer containing a styrene / butadiene copolymer resin, a vinylidene chloride resin, or the like as a main component at 1 to 10 μm.

(Antistatic lubricating layer) An antistatic lubricating layer that can be used in the present invention is provided on the opposite side of the image receiving layer. The antistatic lubricating layer is coated before or after the image receiving layer is provided. Coating is performed by dissolving the cationic copolymer in a solvent such as water, methyl alcohol, ethyl alcohol, or isopropyl alcohol on the opposite surface of the sheet-like substrate provided with the image receiving layer, and thereafter. Used after drying. Coating is not particularly limited, but is usually performed with a coating machine that can apply uniformly and smoothly, such as an air knife coat, a blade coat, a bar coat, a gravure coat, a curtain coat, a roll coat, and the like. Has a coating thickness of 0.1
It is coated so as to be about 5 μm. In addition, as long as it does not adversely affect the performance of the cationic copolymer at the time of coating, if necessary, other resins may be added to this ionic copolymer,
A crosslinking agent, a pigment, and the like can be appropriately mixed and used.

The cationic monomer unit (a) which can be used in the present invention contains a quaternary ammonium base in the unit. Above all, general formula (II)

[0012]

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Wherein A represents O or NH, R ₂ represents hydrogen or CH ₃ , and R ₃ represents an alkylene group having 2 to 4 carbon atoms or a group represented by the formula

[0014]

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Wherein R ₄ , R ₅ and R ₆ represent an alkyl group or an aralkyl group having 1 to 10 carbon atoms which may be the same or different, and X represents a halogen or alkyl sulfate ion By using the monomer unit represented by the formula (1), more excellent antistatic property and lubricity can be imparted.

Specific examples of the cationic monomer unit (a) include (meth) acryloyloxytrimethylammonium chloride, (meth) acryloyloxyhydroxypropyltrimethylammonium chloride, and (meth) acryloyloxytriethylammonium chloride. (Meth) acrylic monomer units such as (meth) acryloyloxydimethylbenzylammonium chloride, (meth) acryloyloxytrimethylammonium methylsulfate, (meth) acrylamidopropyltrimethylammonium chloride, (meth) acrylamidopropyldimethylbenzylammonium chloride And (meth) acrylamide-based cationic monomer units. These may be obtained by polymerizing the corresponding monomer or first polymerizing a monomer having a tertiary amino group, such as dimethylaminoethyl (meth) acrylate or dimethylaminopropylacrylamide, which is a precursor thereof. After that, it may be cationized with a modifying agent such as methyl chloride.

The cationic monomer unit (a) has 15 to 60% by weight of the copolymer. If the amount is less than 15% by weight, the antistatic property becomes insufficient. In particular, at the time of thermal transfer, printing is performed at a high temperature, so that the antistatic property immediately after printing is reduced and transportability becomes a problem. On the other hand, if it exceeds 60% by weight, it becomes excessively hygroscopic and there is no problem in a state where the humidity is controlled. However, when the receiving sheet is stored after printing, it absorbs moisture when the humidity is high, and blocking occurs.
Decrease the commercial value of the print.

As the hydrophobic monomer unit (b) that can be used in the present invention, various units can be used. For example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, Isobutyl (meth) acrylate, tertiary butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2
-Ethylhexyl (meth) acrylate Alkyl (meth) acrylates such as lauryl (meth) acrylate, tridecyl acrylate, and stearyl (meth) acrylate; vinyl esters such as styrene and vinyl acetate; The hydrophobic monomer unit (b) has a content of 30% in the copolymer.
~ 84.9% by weight. If less than 30% by weight,
If the water resistance is insufficient, and if it exceeds 84.9% by weight, the antistatic performance relatively decreases.

The polyorganosiloxane unit (c) which can be used in the present invention has the general formula (I)

[0020]

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(Wherein, R ₁ represents an alkyl group or a phenyl group having 1 to 10 carbon atoms which may be the same or different, and n represents an integer of 5 or more). Here, when n is less than 5, it is difficult to impart sufficient lubricity to the obtained copolymer. The ratio of the polyorganosiloxane unit contained in the cationic copolymer is 0.1 to 20% by weight. If the amount is less than 0.1% by weight, the lubricating property is insufficient, and if it exceeds 20% by weight, the lubricating property cannot be further improved, which is economically disadvantageous.

The polyorganosiloxane unit in the cationic copolymer is specifically incorporated into the copolymer using a precursor represented by the following general formula (a), (b) or (c). It is suitable. The precursors shown in the general formula below can be incorporated into the copolymer using a reactive group D. General formula (A)

[0023]

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(In the formula, D represents a radical polymerizable group selected from the group consisting of a vinyl group, an acryloyloxyalkyl group and a methacryloyloxyalkyl group, or an epoxy group such as a glycidoxyalkyl group or an aminoalkyl group. , R represents an alkyl group having 1 to 10 carbon atoms or a phenyl group, and n represents an integer of 5 or more.

[0025]

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(Where D represents a radical polymerizable group selected from the group consisting of a vinyl group, an acryloyloxyalkyl group and a methacryloyloxyalkyl group, or an epoxy group such as glycidoxypropyl or an aminoalkyl group; R represents an alkyl group having 1 to 10 carbon atoms or a phenyl group, and n represents an integer of 5 or more.

[0027]

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(Wherein D represents an epoxy group such as glycidoxypropyl, an aminoalkyl group or a mercaptoalkyl group, R represents an alkyl group having 1 to 10 carbon atoms or a phenyl group, and m represents 1 to 20 carbon atoms. Represents an integer, and n represents an integer of 5 or more)

As these precursors, those which are commercially available as reactive silicones can be used. However, considering that the reactivity decreases when the molecular weight becomes high, in the case of the general formulas (a) and (b), Is preferably 200 or less as n, and is preferably 400 or less even when there are many reactive groups of the general formula (C). As a method of incorporating these precursors as components of the cationic copolymer, when the reactive group D is a polymerizable group, it may be polymerized simultaneously with another monomer, and when the reactive group D is a mercaptoalkyl group, the precursor may be used. If the cationic monomer (a) and the hydrophobic monomer (b) are polymerized in the presence of a body, they can be efficiently introduced by chain transfer. Further, when the reactive group D is an epoxy group, the copolymerization of the cationic monomer (a) and the hydrophobic monomer (b) is carried out by (meth) acrylic acid or the like reactive with the epoxy group. With a carboxylic acid group-containing monomer or a monomer such as a hydrochloride of a tertiary amine group-containing monomer such as dimethylaminoethyl (meth) acrylate, and then react with the epoxy group of the precursor. Good. Similarly, when the reactive group D is an aminoalkyl group, the cationic monomer (a) and the hydrophobic monomer (b)
May be carried out with a monomer that reacts with an amino group such as glycidyl (meth) acrylate, and then react with the amino group of the precursor. If necessary, other hydrophilic monomers such as hydroxyethyl (meth) acrylate and vinylpyrrolidone may be contained as copolymer components as long as the antistatic property and lubricity are not adversely affected.

As the polymerization method, known radical polymerization methods such as bulk polymerization, solution polymerization and emulsion polymerization can be carried out. A preferred polymerization method is a solution polymerization method, in which each monomer is dissolved in a solvent, a polymerization initiator is added, and the mixture is heated and stirred under a nitrogen stream. As the solvent, water, alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol are preferable, and these solvents may be mixed and used. As the polymerization initiator, peroxides such as benzoyl peroxide and lauroyl peroxide, and azo compounds such as azobisbutyronitrile and azobisvaleronitrile are suitably used. The monomer concentration is usually 10 to 60% by weight, and the polymerization initiator is usually 0.1 to 10% by weight based on the monomer.

The molecular weight of the cationic copolymer depends on the polymerization temperature, the type and amount of polymerization initiator, the amount of solvent used, polymerization conditions such as chain transfer, the type of polyorganosiloxane precursor and the content of reactive groups, and the like. It can be any level. Generally, the molecular weight of the resulting cationic copolymer is preferably in the range of 5,000 to 500,000. The thermal transfer receiving sheet prepared as described above can prevent electrostatic charging even under the condition of low humidity heated immediately after printing, and can prevent slippage of sheets due to mutual slippage, thereby preventing sheet double feeding and paper jam. Further, since the antistatic lubricating layer according to the present invention is not excessively hygroscopic, when the receiving sheet is stored after printing, blocking due to moisture absorption does not occur.

[0032]

The present invention will be further described with reference to the following examples. Parts and% in the examples are parts by weight and% by weight.
Respectively. Example 1 In a four-necked flask equipped with a reflux condenser, a thermometer, a glass tube for purging nitrogen, and a stirrer, 55 parts of methyl methacrylate as a hydrophobic monomer unit (b), and a cationic monomer unit (A) as methacryloxyethyltrimethylammonium chloride 80% aqueous solution 50 parts,
The molecular weight of the polyorganosiloxane unit (c) is 50
5 parts of methacryloxy-modified polyorganosiloxane (FM0721 manufactured by Chisso Corporation) and 140 parts of ethyl alcohol and 1 part of azobisisobutyronitrile as a polymerization initiator were added thereto at 80 ° C. for 6 hours under a nitrogen stream. The polymerization reaction was performed to obtain a 40% ethyl alcohol solution of the cationic copolymer (I). After diluting this with ethyl alcohol to 10%, a 150 μm thick synthetic paper (Yupo FP15, manufactured by Oji Yuka Synthetic Paper Co., Ltd.) was used as a sheet-like substrate.
Using 0), an antistatic lubricating layer was formed on one side of the coating by using a bar coater at a solid content of 2 g / m ² and drying. Next, on the other side of the synthetic paper, 4 g of a solid content of the composition (A) for forming an image receiving layer having the following composition was used.
/ M ^2, and dried to form a dye sublimation image-receiving layer, whereby a thermal transfer receiving sheet was obtained.

Composition for forming image receiving layer Polyester resin 15 parts (Toyobo Co., Byron 200) Toluene 40 parts Methyl ethyl ketone 20 parts Epoxy-modified silicone 5 parts (Shin-Etsu Silicone Co., Ltd., KF100T) This thermal transfer receiving sheet was subjected to a sublimation video printer. The print showed no double feed and no other transport problems. Further, even if the front and back surfaces were rubbed, the damage to the image receiving surface was small. Table 1 shows the surface resistivity and coefficient of friction of the antistatic lubricating layer.

Example 2 In the same manner as in Example 1, methyl methacrylate 55
Parts, methacrylamidopropyltrimethylammonium chloride 40 parts, mercapto-modified polyorganosiloxane having a molecular weight of about 7000 (X-2 manufactured by Shin-Etsu Silicone Co., Ltd.)
2-980) 5 parts and isopropyl alcohol 150
Using 1 part of azobisisobutyronitrile and 1 part of azobisisobutyronitrile, a polymerization reaction was carried out at 80 ° C. for 5 hours under a nitrogen stream to obtain a 40% isopropyl alcohol solution of the cationic copolymer (II).
Using this cationic copolymer, as in Example 1,
An antistatic lubricating layer was formed on one side of a synthetic paper having a thickness of 150 μm at a coating amount of ² g / m ² of solid content. Next, a dye sublimation image-receiving layer having a solid content of 4 g / m ² was formed on one surface of the synthetic paper using the image-receiving layer-forming composition (A). When the obtained thermal transfer receiving sheet was printed with a sublimation video printer, there was no double feed and no other transport problems. In addition, even if the front and back surfaces were rubbed, the image receiving surface was hardly damaged. Table 1 shows the surface resistivity and the coefficient of friction of the antistatic lubricating layer.

Comparative Example 1 In the same manner as in Example 1, 4 g of a solid content was formed on one side of a synthetic paper having a thickness of 150 μm using the composition (A) for forming an image receiving layer.
/ M ^2, a dye sublimation image-receiving layer was formed, and a heat transfer receiving sheet was prepared without providing an antistatic lubricating layer on the other side. When this sheet was printed by a sublimation video printer, many double feeds occurred and the conveyance was blocked. Further, when the front and back surfaces were rubbed, many small scratches were made on the image receiving surface. Table 1 shows the surface resistivity and the coefficient of friction of the synthetic paper on which the antistatic lubricating layer was not applied.

Comparative Example 2 In the same manner as in Example 1, methyl methacrylate 60
Parts, 50 parts of a 80% aqueous solution of methacryloxyethyltrimethylammonium chloride, 140 parts of ethyl alcohol, and 1 part of azobisisobutyronitrile, and a polymerization reaction was carried out at 80 ° C. for 6 hours in a nitrogen stream to obtain a cationic copolymer. A 40% ethyl alcohol solution of the combination (III) was obtained. Using this cationic copolymer, a thickness of 150 μm
An antistatic lubricating layer was formed on one surface of the synthetic paper of Example ^{1 at} a coating amount of ² g / m ² of solids. Next, on the other side of the synthetic paper, using the composition for forming an image receiving layer (A), a solid content of 4% was used.
A g / m ² dye sublimation image-receiving layer was formed. When this thermal transfer receiving sheet was printed by a sublimation video printer, many double feeds were caused and the conveyance was clogged. Further, when the front and back sides were rubbed, many small scratches were made on the image receiving surface. Table 1 shows the surface resistivity and coefficient of friction of the antistatic lubricating layer.

Example 3 In the same manner as in Example 1, methyl methacrylate 52
, 50 parts of a 80% aqueous solution of methacryloxyethyltrimethylammonium chloride, 3 parts of methacrylic acid, 140 parts of ethyl alcohol, and 1 part of azobisisobutyronitrile, and a polymerization reaction was carried out at 80 ° C. for 6 hours under a nitrogen stream. Thereafter, 5 parts of a double-terminal epoxy-modified silicone having a molecular weight of 1000 (FM5511, manufactured by Chisso Corporation) was added, and the mixture was reacted at 80 ° C. for 10 hours to obtain a 40% ethyl alcohol solution of the cationic copolymer (IV). . Using this cationic copolymer, a thickness of 15
An antistatic lubricating layer was formed on one side of a synthetic paper of 0 μm at a coating amount of ² g / m ² of solid content. Next, a dye sublimation image-receiving layer having a solid content of 4 g / m ² was formed on the other surface of the synthetic paper using the image-receiving layer-forming composition (A). When the obtained thermal transfer receiving sheet was printed with a sublimation video printer, there was no double feed and no other transport problems. In addition, even if the front and back surfaces were rubbed, the image receiving surface was hardly damaged. Table 1 shows the surface resistivity and coefficient of friction of the antistatic lubricating layer. In the above example, the surface resistivity was measured immediately after the sheet was heated with a hot air dryer at 100 ° C. for 5 minutes, using a surface resistance meter Hiresta Model HT-250 manufactured by Mitsubishi Yuka.
The friction resistance between the front and back of the receiving sheet was measured by a slip tester method (based on ASTM D1894-73).

[0038]

[Table 1]

[0039]

The thermal transfer receiving sheet prepared as described above prevents electrostatic charging even under a low humidity condition heated immediately after printing, and prevents slippage of sheets due to mutual slippage, thereby preventing sheet double feeding and paper jam. it can. In addition, there is little damage to the image surface. Further, the antistatic lubricating layer according to the present invention is not excessively hygroscopic, so that when the receiving sheet is stored after printing, blocking due to moisture absorption does not occur.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-143195 (JP, A) JP-A-2-281993 (JP, A) JP-A-2-252584 (JP, A) JP-A-3-3 140293 (JP, A) JP-A-61-127390 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/38-5/40

Claims (2)

(57) [Claims] In a thermal transfer receiving sheet provided with an image receiving layer capable of receiving a thermally transferred image on the surface of a sheet-like substrate, a cationic monomer unit ( a) 15 to 60% by weight, a hydrophobic monomer unit (b) 30 to 84.9% by weight, and a compound of the general formula (I) (Wherein R ₁ has the same or different carbon number 1)
Represents an alkyl group or a phenyl group of 10 to 10, and n represents an integer of 5 or more.) A charge mainly comprising a cationic copolymer composed of 0.1 to 20% by weight of a polyorganosiloxane unit (c) A heat transfer receiving sheet comprising an anti-slip layer. 2. The method according to claim 1, wherein the cationic monomer unit (a) has the general formula (II): (Where A represents O or NH, R ₂ represents hydrogen or C
Represents H _3, R ₃ is an alkylene group or a group represented by the formula of 2 to 4 carbon atoms embedded image Wherein R ₄ , R ₅ and R ₆ represent an alkyl group or an aralkyl group having 1 to 10 carbon atoms, which may be the same or different, and X represents a halogen or an alkyl sulfate ion). The heat transfer receiving sheet according to 1.