JPH021383A - Dyeable resin for image-receiving material for sublimation transfer - Google Patents

Abstract

PURPOSE:To enhance developed color density of images or the like by providing a dyeable layer comprising a copolymer obtained by addition polymerization of an aromatic polyester with a lactone and having a glass transition temperature of at least 20 deg.C on a base to produce an image-receiving material for sublimation transfer. CONSTITUTION:A dyeable layer comprising as a main constituent a dyeable resin comprising as a main constituent a block copolymeric polyester resin which is obtained by addition polymerization of a lactone with an aromatic polyester having an aromatic dibasic acid as an acid component and which has a glass transition temperature of at least 20 deg.C is provided on a base such as a paper, a synthetic paper, a film or the like to obtain an image-receiving material for sublimation transfer. The block copolymeric polyester can be obtained by bringing the aromatic polyester and the lactone into polyaddition reaction in a molten state or in a solution. The average molecular weight of the block copolymeric polyester is preferably 5,000-100,000.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a dyeable resin for a sublimation transfer image receptor 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 with a thermal hend, etc., and the sublimable dye is transferred onto a sublimation transfer image receptor facing the thermal transfer sheet, thereby creating an image. It is for obtaining records.

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 above-mentioned sublimation transfer image receptor is conventionally disclosed in JP-A-57-107885, JP-A-60-64899, and JP-A-61-258790.
As shown in Japanese Patent Application Laid-Open No. 62-105689, those 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 that the dyeing layer of a sublimation transfer image receptor having a base material and a dyeing layer provided on the base material contains a dyeable resin. The main component is a block copolymerized polyester resin with a glass transition temperature of 20°C or higher, which is obtained by addition polymerizing lactones to an aromatic polyester containing an aromatic dibasic acid as an acid component. This is a dyeable resin for sublimation transfer image receptors, which is characterized by:

The aromatic polyester used in producing the block copolymerized polyester according to the present invention has an aromatic dibasic acid as an acid component, and the aromatic dibasic acids include terephthalic acid, isophthalic acid, Orthophthalic acid, 1
．． Examples include 5-naphthalic acid, 2,6-naphthalic acid, diphenyldicarboxylic acid, diphenylmethanedicarboxylic acid, and the like.

Furthermore, trifunctional or higher functional components such as trimellitic acid and pyromellitic acid may be included within a range that does not impair the properties. Also,
Glycol components include ethylene glycol, neopentyl glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,4-butanediol, 1°5-bentanediol, 1,6-hexanediol, 3-methylbentanediol, 1, 4-Cyclohexane dimetatool, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, 2,2-diethyl-1,3-propanediol, 2-n-butyl-2-ethyl-13-propanediol etc. Further, trimethylolethane, trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, and other trifunctional or higher functional components may be included as long as their properties are not impaired. Further, before addition polymerizing the lactone, the aromatic polyester may be depolymerized with the above-mentioned trifunctional or higher functional polyol.

The block copolymerized polyester used in the present invention is obtained by subjecting an aromatic polyester to a polyaddition reaction with a lactone in a melt state or in a solution.

Block polyesters can be produced by known methods, such as Japanese Patent Publication No. 48-4116.

Examples of the lactone H to be addition-polymerized to the aromatic polyester include ε-caprolactone, δ-valerolactone, 3-methyl-δ-valerolactone, and ε-caprolactone is particularly desirable.

The ratio of aromatic polyester to lactone is such that the glass transition temperature of the block copolymerized polyester is 20° C. or higher. If the glass transition temperature is less than 20°C, a blocking phenomenon will occur significantly, and staining due to dye migration will worsen at high temperatures.

The number average molecular weight of the block copolymerized polyester used in the present invention is in the range of 5.000 to 100,000, preferably 10,000 to so, ooo. If the molecular weight is less than 5.000, the durability of the dyed layer will decrease;
If it exceeds 0.000, the viscosity of the solution increases, making it difficult to handle.

In the present invention, in addition to the block copolymerized polyester, the dyeing layer (image-receiving layer) contains a lubricating substance such as a silicone compound or a fluorine-containing compound, and a lubricating substance such as a fluorine-containing compound to improve the releasability from the thermal transfer ribbon. For the purpose of improving adhesion and blocking resistance, compounds reactive with block copolyester, such as polyisocyanate compounds, melamine compounds, urea compounds, and epoxy compounds, are used as curing agents. Good too.

Furthermore, for the purpose of improving the light resistance of recorded images, ultraviolet absorbers, radical scavengers, etc. may be added as necessary.

Examples of substrates for which the dyeable resin of the present invention is used include paper, synthetic paper, various films, and various sheets.

As a method for producing a sublimation transfer image receptor using the dyeable resin of the present invention, a method in which a solution of a block copolymer polyester in a battering machine solvent is applied onto a base material and dried is preferable. It is also possible to use methods such as melt extrusion onto a substrate, thermocompression bonding or thermal transfer of a block copolymerized polyester film onto a substrate, and the like.

(Function) In the block copolymerized polyester of the present invention, the aromatic polyester, which is a rigid segment, is effective for the dyeing fastness of sublimable dyes, and the polylactone, which is a flexible segment, is effective for the color development window of the dye. The color development window for dyes and dye fastness are improved, and high-quality images can be obtained.

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

Synthesis examples of various block copolymerized polyester resins used as examples in the present invention and their performance evaluation results are shown below. In the synthesis examples, the term ``parts'' indicates parts by weight, and the term ``molecular weight'' indicates number average molecular weight.

Regarding the performance evaluation method, image density and image durability were evaluated, and the measurement methods thereof are as shown below.

Synthesis example 1 of O block copolymerized polyester resin Thermometer,
In an autoclave equipped with a stirrer, 485 parts of dimethyl terephthalic acid, 485 parts of dimethyl isophthalic M, 435 parts of ethylene glycol, 1050 parts of an ethylene oxide adduct of bisphenol A (average molecular weight: 350), and 0.34 parts of tetrabutoxy titanate were added in 31 parts. The reaction system was charged into an autoclave and heated at 200-230"C for 4 hours to carry out transesterification, and then the reaction system was heated at 26"C for 30 minutes.
Raise the temperature to 0℃ and gradually reduce the system pressure to 260"C11
Excess glycol was drained out at 0 am Hg, and after 45 minutes the temperature was reduced to 0.3 am Hg or less, and under these conditions, the temperature was further increased to 90
After reacting for a minute, nitrogen gas was introduced into the system and the pressure was returned to normal pressure, then 228 parts of ε-caprolactone was charged, and 6 parts were heated at 220°C.
The polyaddition reaction was carried out for 0 minutes.

The obtained resin was a block copolymerized polyester, and its molecular weight was 27,000 when analyzed by GPC.

The resin composition was analyzed by 'H-++n+r, and the results are shown in Table-
Shown in 1.

Synthesis Examples 2 to 5 of O block copolymerized polyester resin The same amount of raw materials as in Synthesis Example 1 were charged in the same equipment as in Synthesis Example 1,
A polycondensation reaction was carried out in the same manner. After changing to a nitrogen atmosphere, 10.2 parts of pentaerythritol was added and 22
The molds were combined at 0'C for 30 minutes, and 228 parts of ε-caprolactone was added in the same manner as in Synthesis Example 1 to perform a polyaddition reaction. The properties of the obtained resin are shown in Table-1. In addition, block copolymerized polyester resin (Synthesis Example 3
-5) were obtained by the method of Synthesis Example 1 or 2. The properties of the obtained resin are shown in Table I.

Comparative Synthesis Examples 1 to 5 of O-block copolymerized polyester resins In Comparative Synthesis Example 1, transesterification was carried out in the same manner as in Synthesis Example 1. After the transesterification reaction was completed, 285 parts of ε-caprolactone was charged, and after heating at 230'C for 1 hour, the pressure was reduced to carry out a polycondensation reaction.

The obtained polyester resin was found to be a random copolymer when analyzed by 'Lnmr.

In Comparative Synthesis Example 2, the same transesterification reaction as in Synthesis Example 1 was carried out, and then adipic acid was charged and after the esterification reaction, a polycondensation reaction was carried out under reduced pressure.

In Comparative Synthesis Example 3, transesterification and polycondensation reactions were carried out under the same conditions as in Synthesis Example 1, and ε-caprolactone 5
13 parts were charged and a polyaddition reaction was performed, and the glass transition temperature was 15°C. Moreover, Comparative Synthesis Example 4 contains 10 mol% of adipic acid as an acid component in the dihydrochloric acid component. A comparative synthesis example is an aromatic polyester obtained in Synthesis Example 1 without adding lactone.

Table 1 shows the evaluation results for each characteristic.

The following is a method for evaluating margin O image density. The image receptor sheet and the thermal transfer sheet are stacked so that the dye layer and the coloring material layer are in contact with each other, and the thermal heft is applied from the base material side of the thermal transfer sheet to a thermal heft output of 0.7.
Heating was performed at W/dot, head heating time of 8 ms, dot density of 3 dots/dot, and the cyan and magenta dyes in the color material layer were transferred to the dyed layer. The density of the resulting transferred image was measured using a Macbeth densitometer.

O Image durability evaluation method ■ Evaluation method of moisture resistance and heat resistance Synthetic paper (Yubo PPG-150 manufactured by Oji Yuka Co., Ltd.
) at 50°C and relative humidity (R1+) 80
% atmosphere for one week to perform aging. After aging, the degree of dye transfer onto the synthetic paper was visually observed, and those with a clearly low degree of transfer were rated as ○ and those with a bright degree of transfer were rated as ×.

■ Evaluation method of light resistance Based on JIS LO842 (exposed for 10 hours under conditions).

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.
It was shown in

O anti-blocking image-receiving layer and the layer on the opposite side are overlapped, 10kg/c+fl
The blocking phenomenon was observed after being left at 40° C. for one day under pressure. Those that can be easily peeled off are rated O, and those that are difficult to peel off after blocking are rated x.

Example 1 The block copolymerized polyester resin obtained in Synthesis Example 1 was dissolved in a solvent of toluene:methyl ethyl ketone=so:so to form a 30% solution. Epoxy-modified silicone oil (Shin-Etsu Chemical type: KF-102) was added to this solution in an amount of 5% by weight based on the resin. The coating was applied to obtain a dry film.

The sheet was dried in an atmosphere of 100'C for 30 minutes to obtain a sublimation transfer image receptor. Table 2 shows the characteristics of the obtained image receptor.
Shown below.

Examples 2 to 8 Sublimation transfer image receptors were obtained in the same manner as in Example 1 using the block copolymerized polyester resins obtained in Synthesis Examples 1 to 5. Examples 2 to 8 are used, and the characteristics are shown in Table 2.

Comparative Examples 1 to 7 Sublimation transfer image receptors of Comparative Example 1 were obtained in the same manner as in Example 1 except for using the random polyester obtained in Comparative Synthesis Example. Its characteristics are shown in Table 3.

Furthermore, sublimation transfer image receptors of Comparative Examples 2 to 7 were obtained using the polyesters obtained in Comparative Synthesis Examples 2 to 5 in the same manner as in Example 1. Its characteristics are shown in Table 3.

As is clear from Margin Table 2 below, the block copolymerized polyester resin of the present invention has excellent performance in dyeing density, light resistance, moisture resistance and heat resistance.

(Effects of the invention) Conventionally, it was difficult to satisfy both coloring sensitivity and dyeing fastness with dyeing resins for sublimation transfer image receptors, but a block made by addition polymerizing lactones to aromatic polyester By using a copolymerized polyester resin, the above-mentioned drawbacks can be largely overcome, and it is possible to obtain high-quality images with excellent color density and durability.

Patent applicant: Toyobo Co., Ltd.

Claims (1)

[Scope of Claims] The dyeing layer of a sublimation transfer image receptor having a base material and a dyeing layer provided on the base material is mainly made of a dyeable resin,
The dyeable resin is characterized in that its main constituent is a block copolymerized polyester resin having a glass transition temperature of 20° C. or higher, which is obtained by addition-polymerizing lactones to an aromatic polyester having an aromatic dibasic acid as an acid component. A dyeable resin for sublimation transfer image receptors.