JP3219166B2 - Polyester resin for image recording media - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin for an image recording medium used for obtaining a printed image formed on a film, paper, metal, glass, cloth or the like.

[0002]

2. Description of the Related Art Image recording in the present invention mainly refers to a color hard copy recording system such as a sublimation transfer system, a melt transfer system, an ink jet system, and an electrophotographic system. In these image recordings, a polyester resin comprises a dye and a pigment. It is used beyond the method in terms of dispersibility, dyeing property, affinity and the like. For example, as a dyeing resin used for a dyeing layer of a sublimation transfer image-receiving paper, a conventional dyeing resin is disclosed in
-107885, JP-A-60-64899, JP-A-61-258790, JP-A-62-1
As shown in JP-A-05689, there is known one containing a saturated polyester as a main component.

[0003]

Conventionally, a sublimation transfer method,
When a saturated polyester soluble in an organic solvent is used to obtain a printed image in a melt transfer method, an ink jet method, and an electrophotographic method, a high-quality image with good color density, gradation, color reproducibility, and sharpness can be obtained. Although, fingerprints, oil components represented by various cosmetics, erasers, the storage stability of the image due to contamination of the plasticizer component of the vinyl chloride sheet, etc., triggered by the resin attacked by those components, The durability of the obtained printed image is not sufficient, especially in long-term storage, there are problems such as discoloration, image disorder,
It was not at a level that satisfied the required characteristics.

[0004] It is an object of the present invention to provide an organic solvent-resistant, oil- and fat-resistant, fingerprint-resistant and fingerprint-resistant, which causes disturbance of an image formed by a sublimable dye, a pigment ink, a dye ink, a dye toner, a pigment toner and the like. An object of the present invention is to provide a polyester resin exhibiting a property of being excellent in plasticizer properties and further having an affinity for a dye.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies on polyester resins in order to achieve the object of the present invention. As a result, polyester resins having the following composition have been obtained.
The inventors have found that the storage stability of an image is excellent and arrived at the present invention. That is, the present invention has a glass transition temperature of 40 ° C. or higher, a resin specific gravity of 1.25 or higher, an SP value of 9.50 to 12.0, is insoluble in a single organic solvent, is soluble only in a mixed organic solvent, and 60 of the glycol component of the polyester component
A polyester resin for an image recording medium, comprising an amorphous saturated copolymerized polyester resin in which at least mol% is ethylene glycol.

The carboxylic acid component in the polyester of the present invention includes, for example, terephthalic acid, isophthalic acid, orthophthalic acid, 2,3-naphthalic acid, 1,1,3-trimethyl-3-phenylindene-4 ', 5-dicarboxylic acid And dicarboxylic acids that can be used in addition to aromatic dicarboxylic acids such as 5-sodium sulfoisophthalic acid, aromatic carboxylic acids such as p- (hydroxyethoxy) benzoic acid, succinic acid, adipic acid, and the like. Aliphatic dicarboxylic acids such as azelaic acid, sebacic acid, dodecanedicarboxylic acid, fumaric acid, maleic acid,
Examples include unsaturated aliphatic and alicyclic dicarboxylic acids such as tetrahydrophthalic acid and 1,4-cyclohexanedicarboxylic acid, and tri- and tetracarboxylic acids such as trimellitic acid and pyromellitic acid.

As the glycol component, ethylene glycol accounts for at least 60 mol% of the total glycol component. Glycol components other than ethylene glycol used in less than 40 mol% of the total glycol components include diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6- Hexanediol, neopentyl glycol, triethylene glycol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, cyclohexanedimethanol, tricyclodecanedimethylol, bisphenol A ethylene oxide and propylene oxide adducts, Hydrogenated bisphenol A
Of ethylene oxide and propylene oxide. 2,2-diethyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3
-Propanediol and the like. Of these, propylene glycol, neopentyl glycol, polyethylene glycol, tricyclodecane dimethylol, ethylene oxide addition of bisphenol A,
Neopentyl glycol and cyclohexanedimethanol.

In the polyester resin of the present invention, it is essential that ethylene glycol is contained in the total glycol component in an amount of 60 mol% or more. If the content of the glycol is less than 60 mol%, an organic solvent and a plasticizer The resulting image recording is liable to be attacked by oil and fat components, resulting in deterioration of properties of the obtained image recording such as plasticizer resistance, fingerprint resistance and oil and fat resistance.

The Tg of the obtained aqueous polyester resin is 4
The temperature is 0 ° C or higher, preferably 50 ° C or higher. Tg
Is less than 40 ° C., the heat resistance, blocking resistance, etc. of the obtained image are significantly reduced, and the image is blurred and discolored even at about room temperature, adversely affecting the storage stability of the obtained hard copy. Effect.

The water-based polyester resin of the present invention has
The P value is from 9.5 to 12.0. If the P value is less than 9.5, the affinity between the plasticizer and the organic solvent having a high affinity is increased, and the durability of the image and the resistance to the organic solvent are reduced. Let me do it. When the SP value exceeds 12.0, the affinity for water, alcohol, and the like is increased, and the water resistance and the durability of cosmetics and the like other than the plasticizer are significantly reduced.

The specific gravity of the obtained polyester resin is 1.2.
It is essential that it is 5 or more, and if it is less than 1.25,
The storage stability of the recorded image of the image is significantly reduced. Also, by defining the specific gravity of the resin, it becomes possible to control the ratio of ethylene glycol in all the glycol components contained in the polyester resin.

With respect to solubility in organic solvents, it is essential that the polyester resin itself or the obtained hard copy according to the present invention does not completely dissolve in a single organic solvent. In many cases, plasticizers for plastics and the like having an affinity for organic solvents are used.
This is a necessary property against image contamination. However, in consideration of affinity with dyes, coloring materials, pigments, and the like, solubility of the polyester resin in the mixed organic solvent is essential. In the case of a polyester resin having no solubility in a mixed organic solvent, in order to decrease the affinity with a dye, a coloring material, a pigment, and the like, they are aggregated, precipitated, separated over time, and finally formed. Problems such as discoloration and disturbed images occur.

The coating method using the polyester resin according to the present invention is generally used by dissolving the polyester resin in a solvent, or in the form of a non-aqueous dispersion, an aqueous dispersion or an aqueous solution (solvent-free). Can be used with The solid concentration is generally used at about 5 to 70% by weight.

In the present invention, it can be mixed and / or reacted with a resin other than the polyester resin of the present invention. As the resin to be mixed, polyvinyl resin, polycarbonate resin, polyacrylic acid resin,
Examples include polymethacrylic acid-based resins, polyolefin-based resins, cellulose derivative-based resins, polyether-based resins, and polyester-based resins.

The polyester resin of the present invention can be thermoset or crosslinked for the purpose of further improving image durability. Examples of the thermosetting resin used in combination with the crosslinking agent include a silicone resin, a melamine resin, a phenol-formaldehyde resin, an epoxy resin, and an isocyanate resin. In addition, ion crosslinking,
Radiation crosslinking and the like.

In the present invention, various lubricating substances can be blended in addition to the aqueous polyester resin of the present invention for the purpose of improving releasability. As the lubricating substance, a fluorine-based resin, a silicon-based resin, and an organic sulfonate compound,
Interface lubricants such as organic phosphate compounds and organic carboxylate compounds can be used.

Further, the polyester resin in the present invention comprises:
For the purpose of improving the light fastness of the recorded image, an ultraviolet absorber, an antioxidant and the like can be added. The substrate of the image recording medium is not particularly limited, and examples thereof include paper, synthetic paper, various films, various sheets, metal, and glass.

[0018]

EXAMPLES Hereinafter, the present invention will be described with reference to production examples and examples in order to specifically explain the present invention. In the Production Examples and Examples, “parts” means “parts by weight” and “%” means “% by weight”. The number average molecular weight of the produced polymer was measured by GPC, and the polymer composition was measured by 1 H-NMR. Also,
Glass transition temperature was measured by DSC. These results are shown in Table 1.

Resin specific gravity, SP value, heat resistance, plasticizer resistance,
The measuring method and the calculating method for the fingerprint resistance and the solvent resistance are as shown below, and the evaluation results are shown in Table 2.

(1) Production Example of Polyester (i) Production of Polyester A In an autoclave equipped with a thermometer and a stirrer, 252 parts of dimethyl terephthalate and 136 parts of dimethyl isophthalate were added.
Parts, 165 parts of ethylene glycol, 132 parts of propylene glycol, and 0.5 part of tetrabutoxytitanate, and heated at 150 to 220 ° C. for 240 minutes to perform transesterification. Then, the reaction system was heated to 240 ° C. for 10 minutes. , Gradually reduce the system pressure to 0.3mmHg after 25 minutes
The reaction was continued under the above conditions for further 60 minutes to obtain a pale yellow transparent polyester A. The number average molecular weight of the obtained resin was 7,000. (Ii) Preparation of Polyester B Terephthalate was placed in an autoclave equipped with a thermometer and a stirrer.
Dimethyl phthalate 194 parts, dimethyl isophthalate 194
Parts, ethylene glycol 203 parts, propylene glycol
86 parts, 0.5 part of tetrabutoxy titanate
And heat at 150-220 ° C for 240 minutes
And then raise the temperature of the reaction system to 240 ° C in 10 minutes.
And gradually reduce the pressure of the system to 0.3 mmHg after 25 minutes.
The reaction was continued for another 70 minutes under these conditions.
A transparent polyester A was obtained. Number average of the obtained resin
The molecular weight was 10,000. (Iii) Preparation of Polyester C Terephthalate was placed in an autoclave equipped with a thermometer and a stirrer.
Dimethyl phthalate 194 parts, dimethyl isophthalate 194
Parts, ethylene glycol 223 parts, tricyclodecanedi
78.5 parts of methylol, cyclohexane dimethanol 5
7.6 parts, 0.5 part of tetrabutoxy titanate
And heat at 150-220 ° C for 240 minutes
And then raise the temperature of the reaction system to 240 ° C in 10 minutes.
And gradually reduce the pressure of the system to 0.3 mmHg after 25 minutes.
The reaction was continued for another 70 minutes under these conditions.
A transparent polyester A was obtained. Number average of the obtained resin
The molecular weight was 11,000. (Iv) Production of Polyester D Terephthalate was placed in an autoclave equipped with a thermometer and a stirrer.
186 parts of dimethyl luate , 186 parts of dimethyl isophthalate
Part, 5-sodium sulfoisophthalic acid 24 parts, ethyl
Glycol 254 parts, diethylene glycol 33 parts,
Charge 0.5 part of tetrabutoxytitanate, 150-
Heat at 220 ° C for 240 minutes to perform transesterification.
The temperature of the reaction system was raised to 240 ° C in 10 minutes,
Gradually reduce the pressure to 0.3 mmHg or less after 25 minutes.
The reaction was continued for another 90 minutes under the conditions
Ester A was obtained. The number average molecular weight of the obtained resin is 18
000. (V) Production of polyester E Terephthalate in autoclave equipped with thermometer and stirrer
Dimethyl phthalate 175 parts, dimethyl isophthalate 213
Parts, 161 parts of ethylene glycol, tricyclodecanedi
353 parts of methylol, tetrabutoxy titanate 0.5
And heated at 150 to 220 ° C for 240 minutes.
After a steal exchange, the reaction system was heated to 240 ° C. for 10 minutes.
And gradually reduce the system pressure to 0.3 after 25 minutes.
mmHg or less, and the reaction was continued under these conditions for another 70 minutes.
Thus, a pale yellow transparent polyester A was obtained. The obtained resin
Had a number average molecular weight of 12,000. (Vi) Production of polyester F In an autoclave equipped with a thermometer and a stirrer,
155 parts of dimethyl luate, cyclohexanedicarboxylic acid 2
06 parts, ethylene glycol 155 parts, propylene glycol
148 parts of coal and 0.5 parts of tetrabutoxytitanate
Prepare, heat at 150-220 ° C for 240 minutes,
Exchange and then bring the reaction system to 240 ° C for 10 minutes.
Raise the temperature, gradually reduce the pressure of the system, 0.3 mm after 25 minutes
Hg or lower, and the reaction was continued under these conditions for another 70 minutes.
A pale yellow transparent polyester A was obtained. Number of resins obtained
The average molecular weight was 12,000. (Vii) Production of polyester G Terephthalate in autoclave equipped with thermometer and stirrer
Dimethyl phthalate 194 parts, dimethyl isophthalate 194
Part, 164 parts of ethylene glycol, neopentyl glyco
183 parts and 0.5 parts of tetrabutoxytitanate
And heat at 150-220 ° C. for 240 minutes,
Exchange, then raise the reaction system to 240 ° C in 10 minutes
And gradually reduce the pressure of the system to 0.3 mmH after 25 minutes.
g and the reaction was continued under these conditions for another 90 minutes.
A yellow transparent polyester A was obtained. Shirahira of the obtained resin
The average molecular weight was 18,000.

(2) Method of Measuring Resin Specific Gravity The specific gravity of the obtained polyester resin was measured by a floating and sedimentation method using a 30 ° C. aqueous solution of calcium chloride. (3) Calculation method of SP value The SP value of the obtained polyester resin was calculated by the method of Small et al.

(4) Evaluation method of heat-resistant dye deposition The image receiving body to which the cyan dye has been transferred is left in a dark place at 60 ° C. for 200 hours, aged, and images are compared with those before the heat resistance test. Aggregation, precipitation, and separation of the dye were visually judged, and those having an abnormality were rated from 1 to 5 with no change, and indicated in five stages according to the degree. (5) Evaluation method of heat resistance (dark fading rate) The image receiving body to which the cyan dye was transferred was left to stand in a dark place at 60 ° C. for 200 hours, aged, and compared with the density before the heat resistance test. It was shown by the dye concentration retention (%).

(6) Evaluation method of plasticizer resistance The surface of the image receiving body onto which the cyan dye has been transferred has a thickness of 80 μm.
A 1 cm @ 2 film of vinyl chloride was applied, and a load of 5 g was further applied on the vinyl chloride film. The film was allowed to stand at 40 DEG C. for 24 hours to see the color loss of the cyan dye and traces of the film. . After aging, those having no change such as color omission without a film mark on the image receiving layer surface were evaluated as ○, those with no change in color but film marks remained as Δ, and those with changed color and film marks remained as X. . (7) Fingerprint resistance evaluation method Thumb is pressed firmly on the surface of the image receiving body to which the cyan dye has been transferred so that the fingerprint remains on the image surface, and is left under an environment of 40 ° C. for 48 hours. , Color loss, and fingerprint traces were observed. After aging, the sample having no color change on the surface of the image receiving layer and having no change in color was evaluated as ○, the sample with no color change but with fingerprint trace remaining was evaluated as △, and the sample in which the dye aggregated on the image surface was evaluated as ×.

(8) Evaluation method of solvent resistance The obtained polyester resin was added to a solvent of methyl ethyl ketone, toluene, methyl ethyl ketone: toluene = 50: 50 so as to have a solid concentration of 20%, and heated to 60 ° C. for 4 hours. The solubility of the heated resin was visually determined. A system in which the form was not completely dissolved and the shape was maintained was evaluated as ○, and the others were evaluated as ×.

Example 1 Polyester resin A was treated with toluene: methyl ethyl ketone =
The mixture was diluted with a 50:50 mixed organic solvent to obtain a 20% solution. It was applied on a 150 μm-thick polyethylene terephthalate-based synthetic paper by a bar coater so that the dry coating thickness was 7 to 10 μm. This solution was blended with 5% by weight of silicone-modified oil (KF-857, manufactured by Shin-Etsu Chemical Co., Ltd.) based on the resin content. Drying at 120 ° C 2
This was performed under the condition of 0 minutes.

Examples 2 to 3 Dyeing layers were formed in the same manner as in Example 1 using polyesters B to C, and Examples 2 to 3 were respectively performed.

Comparative Example 1 A dyeing layer was provided in the same manner as in Example 1 using polyester D, and Comparative Example 1 was obtained.

Comparative Examples 2 to 4 Using polyesters E to G, dyeing layers were provided in the same manner as in Example 1 to obtain Comparative Examples 2 to 4.

Example 5 10 parts of an epoxy resin (Epicoat 1004, manufactured by Shell Chemical) and 5 parts of carbon black (F-Tex-8, manufactured by Cabot Corporation) were mixed and pulverized by a ball mill with 100 parts of roughly pulverized polyester A. After that, the mixture was melt-mixed with a roll mill. After cooling, the mixture was pulverized by a Hosokawa pulverizer. The obtained fine powder was classified and 3 to 20 μm was selected to obtain a toner. 90 parts of carrier-iron powder (EFV200 / 300, manufactured by Nippon Iron Powder Co., Ltd.) was mixed with 10 parts of this toner to prepare a developer. Using this developer, copying was performed with a dry plain paper electrophotographic copying machine to obtain an image. Table 3 shows the results.

Examples 6 and 7 Dyeing layers were provided in the same manner as in Example 5 using polyesters B and C, and Examples 6 and 7 were produced. Table 3 shows the results.

Comparative Example 5 Using a polyester D, a dyeing layer was provided in the same manner as in Example 5 to obtain Comparative Example 5. Table 3 shows the results.

Comparative Examples 6 to 8 Using polyesters E to G, dyeing layers were provided in the same manner as in Example 5 to obtain Comparative Examples 6 to 8. Table 3 shows the results.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

[Table 3]

[0036]

EFFECT OF THE INVENTION Either 60% by mole or more of the glycol component of the polyester component is ethylene glycol, and the glass transition temperature, the specific gravity and the SP value are in specific ranges, and the specific non-glycol having selective solubility in organic solvents. When used in the image recording layer of an image recording medium, the recorded image is resistant to organic solvents, oils and fats, fingerprints, plasticizers, dyes, etc. It shows excellent characteristics.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08G 63/00-63/91

Claims (1)

(57) [Claims] 1. A glass transition temperature of 40 ° C. or higher, a resin specific gravity of 1.25 or higher, an SP value of 9.50 to 12.0, not soluble in a single organic solvent, but soluble only in a mixed organic solvent, and 60 mol% of the glycol component of the polyester component
A polyester resin for an image recording medium, comprising an amorphous saturated copolymerized polyester resin comprising ethylene glycol as described above.