JPH01259989A - Dye adhesive resin for sublimated transfer image receiving sheet - Google Patents

Abstract

PURPOSE:To improve coloring density of an image and durability by employing modified polyester resin having Lewis acid skeleton or Lewis acid type polar group. CONSTITUTION:Dye adhesive resin for forming a dye adhesive layer of a sublimated transfer image receiving sheet contains as a main ingredient modified polyester resin including Lewis acid skeleton or/and Lewis acid polar group. The skeleton includes, for example, alkoxyborane skeleton. The polar group includes, for example, nitroso group, nitro group, isothiocyanate group, etc. Since the skeleton and the polar group become the stable adsorption point of sublimated dye molecule, coloring sensitivity for the dye and dye adhering rigidity are improved, and an image having high coloring density and durability is obtained.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a dyeable resin for sublimation transfer image-receiving paper used in combination with a thermal transfer sheet containing a sublimation dye.
It improves its color development and dye fastness.

(Prior art) In the conventional transfer method, a thermal transfer sheet coated with a sublimable disperse dye is heated by a thermal head or the like to transfer the sublimable dye onto a sublimation transfer receiver paper facing the thermal transfer sheet. It is for obtaining an image record.

By using the coloring materials as cyan, magenta, yellow, and black if necessary, and sequentially recording them by heat transfer and overlapping,
Full color images can be obtained.

The dyeing resin used in the dyeing layer of the sublimation transfer image-receiving paper has conventionally been disclosed in Japanese Patent Application Laid-Open Nos. 57-107885, 60-64899, 61-258790, As shown in Japanese Patent No. 62-105689, materials containing saturated polyester as a main ingredient are known.

In addition, with the aim of improving the dye density and the stability of printed image quality, a dyeing layer made of saturated polyester resin or the like was impregnated with finely powdered oxide as a dye adsorbent. -54888 Publication, Jikai Showa 60-
101089, JP-A-59-133098, etc.

(Problems to be Solved by the Invention) Conventionally, when a saturated polyester is used alone as a dyeing layer, a high quality image with good gradation can be obtained, but the color density is not sufficient. In addition, regarding the stability of images, there are problems in that in hot and humid conditions, dyes that have been dyed may migrate and contaminate other transfer objects, and that the clarity of images decreases during storage due to poor light resistance. There was a point.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a dyeable resin forming a dyed layer of a sublimation transfer image-receiving paper, in which the dyeable resin has a Lewis acid skeleton or/and This is a dyeable resin for sublimation transfer image-receiving paper, characterized in that the main component is a modified polyester resin having a Lewis acid type polar group.

The Lewis acid skeleton in the present invention includes, for example, an alkoxyborane skeleton. As a method for introducing an alkoxyborane skeleton into the modified polyester resin of the present invention, tolbutyl borate, tripropyl borate, triethyl borate, tolmethyl borate, triphenyl borate, etc. are copolymerized with other polyesters as monomer raw materials. Among the above boron compounds, a method using tributyl borate is preferred.

Examples of the Lewis acid type polar group in the present invention include a nitroso group, a nitro group, a carbonyl group, a cyano group, an isocyano group, a cyanate group, an isocyanate group, a thiocyanate group, and an isothiocyanate group. Among these, a nitro group is preferred. As a method for introducing a nitro group into the modified polyester resin of the present invention, 5-nitroisophthalic acid, nitroterephthalic acid, 2-(2-nitrophenyl)-1,3-propanediol, etc. are used as monomer raw materials. There is a method of polymerization using it together with other polyester copolymerization components, or a method of introducing it by reacting an organic diisocyanate at the end of the polyester glycol and extending the chain with the diamine compound described below. Examples of the diamine compound include 5-nitro-m-phenylenediamine, 2-nitrophenylenediamine, and the like. Furthermore, there is a method of adding the following monofunctional compound to the polyester glycol terminal via an organic diisocyanate. The -functional compounds include 2-(2,4-dinitrophenyl)ethanol, 2-
Examples include cyano-4-nitroaniline and p-nitrobenzyl alcohol.

Among the above Lewis acid type polar group-containing compounds, preferably 5
-nitroisophthalic acid, 2-cyano-4-nitroaniline, most preferably 5-nitroisophthalic acid.

Examples of the organic diisocyanate include hexamethylene diisocyanate, tetramethylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, p-xylylene diisocyanate, m-
-xylylene diisocyanate, 1,3-diisocyanate methylcyclohexanone, 1,4-diisocyanate methylcyclohexanone, 4,4'-diisocyanate dicyclohexane, 4,4'-diisocyanate cyclohexylmethane, isophorone diisocyanate), 2
．． 4-tolylene diisocyanate, 2.6-)lylene diisocyanate, p-phenylene diisocyanate,
Examples include diphenylmethane diisocyanate, m-phenylene diisocyanate, 2,4-naphthalene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 4,4'-diisocyanate diphenyl ether, 1,5'-naphthalene diisocyanate, and the like. Among these, p-xylylene diisocyanate, m-xylylene diisocyanate,
These are hexamethylene diisocyanate, tetramethylene diisocyanate, and isophorone diisocyanate.

In the modified polyester resin of the present invention, the Lewis acid skeleton or Lewis acid type polar group has a concentration of, for example, a boron atom or a nitro group of 30-1,000@Q/10'
It is appropriate that it be included so that it becomes g.

The Lewis acid skeleton or Lewis acid type polar group in the modified polyester resin of the present invention serves as an adsorption point for sublimable dyes,
It is thought that it stably binds dye molecules. Therefore, if the concentration of the Lewis acid skeleton or Lewis acid type polar group is lower than the above range, sufficient improvement in dyeing sensitivity and dyeing fastness will not be achieved, and if the concentration exceeds the above range, the solvent solubility of the resin will decrease. , it becomes impossible to coat onto the substrate.

The carboxylic acid components of the modified polyester resin in the present invention include terephthalic acid, isophthalic acid, orthophthalic acid, 2.
Aromatic dicarboxylic acids such as 6-nartaric acid, aromatic oxycarboxylic acids such as p-oxybenzoic acid and p-(hydroxyethoxy)benzoic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, etc. Unsaturated aliphatic dicarboxylic acids, fumaric acid, maleic acid, itaconic acid, tetrahydrophthalic acid, l,4-cyclohexanedicarboxylic acid, and alicyclic dicarboxylic acids, trimellitic acid, trimesic acid, pyromellitic acid, etc. Examples include tri- and tetracarboxylic acids. Among these acid components, it is preferable that aromatic dicarboxylic acids account for 70 mol % or more based on the total acid components.

In addition to the aforementioned diol having a Lewis acid type polar group, examples of the glycol component of the modified polyester resin include ethylene glycol, neopentyl glycol, diethylene glycol, dipropylene glycol, and 2,3.4-trimethyl-1,3-bentanediol. , 3-methyl-pentane-1,5-diol, 1,4-cyclohexane dimetatool, ethylene oxide additive of bisphenol A, ethylene oxide and propylene oxide adduct of hydrogenated bisphenol A, polyethylene glycol, polypropylene glycol , polytetramethylene glycol, 2,2-diethyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol, and the like.

Among the above glycol components, preferably ethylene glycol, neopentyl glycol, 3-methylpentane-1
, 5-diol, ethylene oxide adduct of bisphenol A, 2,2-diethyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol, and the like. Furthermore, trimethyloles such as trimethylolethane, trimethylolpropane, glycerin, and pentaerythritol, and tetraols may be used in combination with the above glycol component.

In addition to the above copolymerization components, various lactone compounds can be used as copolymerization components in the modified polyester resin of the present invention. Examples of the lactone compound include S-valerolactone, ε-caprolactone, β-propiolactone, β-2,2-dimethylpropiolactone, and the like. These lactone compounds may be randomly copolymerized in the modified polyester resin of the present invention, and if necessary, ring-opening addition polymerization is performed on the terminal groups of the modified polyester resin to obtain a block copolymerized modified polyester resin. You can also do that.

The number average molecular weight of the modified polyester resin of the present invention is 2.
000-100.000, preferably 5.000-50
．． If the molecular weight is less than 2.000 in the range of 0.000, the durability of the dyed layer decreases, and if it exceeds 100.000, the solution viscosity becomes too high and it becomes difficult to handle, which is not preferred.

In the present invention, various lubricating substances may be blended in addition to the modified polyester resin of the present invention for the purpose of improving the releasability from the thermal transfer sheet.

The above-mentioned lubricating substances include fluororesins, silicone resins, organic sulfonate compounds, organic phosphate compounds,
Examples include interfacial lubricants such as organic carboxylate compounds.

Further, the modified polyester resin in the present invention may contain an ultraviolet absorber, a radical scavenger, etc., if necessary, for the purpose of improving the light resistance of recorded images. As the above-mentioned compounds, benzophenone derivatives, quinone compounds, etc. are used.

(Function) The Lewis acid skeleton and Lewis acid type polar group of the modified polyester resin of the present invention serve as stable adsorption points for sublimable dye molecules, so that the color development sensitivity and color fastness to dyes are improved.

(Example) Hereinafter, the present invention will be specifically explained with reference to Examples.

Production examples of various modified polyester resins used as Examples in the present invention and their performance evaluation results are shown below. In the production examples, parts simply indicate parts by weight.
Molecular weight simply refers to number average molecular weight.As for performance evaluation methods, image density and image durability are measured.

The details are as shown below, and the evaluation results are shown in Table 2.

1. Production example of modified polyester resin 1. Dimethyl terephthalic acid 4 was placed in an autoclave equipped with a meter and a stirrer.
46 parts of dimethyl isophthalic acid, 398 parts of ethylene glycol, 400 parts of neopentyl glycol, and 0.68 parts of tetrabutoxy titanate were charged.
Perform transesterification by heating at 0 to 230°C for 120 minutes,
Then 21 parts of 5-nitroisophthalic acid and 1 part of sebacic acid
11 parts were charged and the reaction was further carried out at 220-230'C for 1 hour. Next, the temperature of the reaction system was raised to 250 °C in 30 minutes, the pressure of the system was gradually decreased, and after 45 minutes, Q, 3ms +) 1
The reaction was continued under these conditions for an additional 60 minutes to obtain a pale yellow transparent modified polyester resin A. The molecular weight of the obtained resin was 15,000. Table 1 shows modified polyester resins BD, I, and J obtained by the same manufacturing method. The resin composition was analyzed by 'H-nmr, and the molecular weight was analyzed by GPC.

The concentration of nitro groups contained was determined from the elemental analysis value (N).

Production Example 2 of Modified Polyester Resin 485 parts of dimethyl terephthalic acid, 485 parts of dimethyl isophthalic acid, 409 parts of ethylene glycol, 485 parts of neopentyl glycol and 0.68 parts of tetrabutoxy titanate were placed in the same autoclave as in Production Example 1.
Transesterification is carried out by heating at 150 to 230°C for 120 minutes. The reaction system was then heated to 250°C for 30 minutes,
Gradually reduce the system pressure to 0.3 m va It after 45 minutes.
g or less, and the reaction was continued under these conditions for an additional 60 minutes.

Next, Nt was blown into the system to bring it to normal pressure, and the temperature inside the system was cooled to 210°C. 23 parts of tryptoxy borate was added and the reaction was carried out for 90 minutes under N2 atmosphere at 210''C to obtain a light yellow transparent polyester resin G. The molecular weight of the obtained resin was 20,000.

Table 1 shows modified polyester resins E-H obtained by a similar manufacturing method. Resin composition is 'H-n+mr
The molecular weight was analyzed by GPC. The boron concentration contained was determined from the elemental analysis value (B).

Production Example 3 of Modified Polyester Resin 485 parts of dimethyl terephthalic acid, 485 parts of dimethyl isophthalic acid, 409 parts of ethylene glycol, 485 parts of neopentyl glycol, and 0.68 parts of tetrabutoxy titanate were placed in the same autoclave as in Production Example 1.
Heating at 0 to 230 °C for 120 minutes to carry out transesterification.Then, the reaction system was heated to 250 °C in 30 minutes, the pressure of the system was gradually reduced to 0.3 msHg or less after 45 minutes, and further under these conditions. Continue the reaction for 30 minutes, 12,000 molecules
A polyester diol P was obtained.

100 parts of the above polyester diol P was placed in a reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser, and 70 parts of toluene was added.
After charging and dissolving 1 part of isophorone diisocyanate
3 parts and 0.03 part of diptyltin diurarate were charged and reacted at 90 to 100°C for 2 hours.

Next, after diluting with 65 parts of toluene, 5-nitro-m-
After charging 3 parts of phenylenediamine and reacting at 80 to 90°C for 3 hours, lower the temperature to 70°C and add 135% of methyl ethyl ketone.
The mixture was further reacted for 2 hours to obtain a modified polyester resin M. The molecular weight of the obtained modified polyester M is 42
,000.

Production Example 4 of Modified Polyester Resin In a reaction vessel equipped with a thermometer, a stirrer, and a reflux type cooler, 100 parts of the polyester diol P used in Production Example 3 and 66 parts of toluene were charged and dissolved, followed by 24.5 parts of isophorone diisocyanate. and diptyltin dilaurate 0.0
Next, 100 parts of toluene and 166 parts of methyl ethyl ketone were added, and the reaction temperature was cooled to 40°C.
18 parts of nitroaniline was added and reacted at 40° C. for 1 hour to obtain a modified polyester resin N having a molecular weight of 3,000.

Modified polyester resin M
, N are shown in Table 1. The resin composition was analyzed by 'H-n@r, and the molecular weight was analyzed by GPC. The concentration of nitro groups contained was determined from the elemental analysis value (N).

Z Image Density Evaluation Method The image receptor sheet and the heat transfer sheet are placed one on top of the other so that the dyed layer and the coloring material layer are in contact with each other, and the output of the thermal head is set to 0. 7
Heating was performed at W/dot, head heating time of 8+ms, and dot density of 3 dots/■ to transfer the cyan and magenta dyes in the color material layer to the dyed layer. The density of the resulting transferred image was measured using a Macbeth densitometer.

3. Evaluation method of image durability ■ Evaluation method of moisture resistance and heat resistance Synthetic paper (Yubo PPG-150 manufactured by Tamago Yuka Co., Ltd.
) at 50°C and relative humidity (RH) 80
% atmosphere for one week to perform aging. After aging, the degree of transfer of the dye onto the synthetic paper was visually observed, and those with a clearly low degree of transfer and those with a high degree of O transfer were rated x.

■ Light resistance evaluation method: Exposure was performed for 10 hours under conditions based on JIS LO842. The image density after the above test was measured using a Macbeth densitometer, and the dye density retention rate (%) was compared with the density before the light fastness test.
).

Example 1 Modified polyester resin A was dissolved in a solution of toluene:methyl ethyl ketone = 50:50 to make a 40% solution. Epoxy-modified silicone oil (Shin-Etsu Chemical: KF-102) was added to this solution in an amount of 10% by weight based on resin A.
Synthetic paper with a thickness of 150 μm (manufactured by Tamago Yuka: Yupo PPG-1
50) was coated using a wire bar so as to obtain a dry coating film of 4μ positive. The sheet was dried in an atmosphere at 100° C. for 30 minutes to obtain a dyed layer.

Examples 2 to 12 Using modified polyester resins B-J, M, and N, a dyed layer was provided by the same method as in Example 1, and Example 2 was obtained, respectively.
~12.

Comparative Examples 1 and 2 Comparative Examples 1 and 2 were obtained by using L as a modified polyester resin and providing dyed layers in the same manner as in Example 1.

As is clear from Table 2 below, modified polyester resins having a Lewis acid skeleton and/or a Lewis acid type polar group have excellent performance in terms of dye density, light resistance, moisture resistance and heat resistance.

(Effects of the invention) Conventionally, it has been difficult to satisfy both coloring sensitivity and dyeing fastness with dyeing resins for sublimation transfer image-receiving paper, but compounds having a Lewis acid skeleton or a Lewis acid type polar group By using a modified polyester resin into which is introduced, the above-mentioned drawbacks can be largely overcome, and it is possible to obtain images with excellent color density and durability.

Patent applicant: Toyobo Co., Ltd.

Claims (1)

[Scope of Claims] In the dyeing resin forming the dyeing layer of the sublimation transfer image-receiving paper, the dyeing resin mainly contains a modified polyester resin having a Lewis acid skeleton and/or a Lewis acid type polar group. A dyeable resin for sublimation transfer image-receiving paper, which is characterized by: