JPH06234269A - Water-dispersed resin composition for image recording medium - Google Patents

Abstract

PURPOSE:To obtain a water-dispersed resin composition having a high dyeability with a dye or a pigment and a superior stability to fat and oil components, plasticizer components, heat, light, and the like. CONSTITUTION:A water-dispersed resin composition to be used for an image recording medium is mainly composed of a resin composition composed of a polyester resin (A) and water (B) in a composition ratio of (A)/(B) = (5-50)/(95-50). In the polyester resin (A), 65mol% or more of a glycol component is made of an ethylene glycol, hydrophilic polar groups are contained, Tg is 40 deg.C or higher, and a specifc gravity is 1.25 or more (30 deg.C).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-dispersed polyester resin composition for image recording media which is 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 refers to a sublimation transfer system, a melt transfer system, an electrophotographic system, an inkjet system, etc., and in such a system, a polyester resin is excellent in dyeing property to a dye or a pigment. However, it is usually used. For example, as an image receiving resin in a sublimation transfer system, as disclosed in JP-A-57-107885, JP-A-60-64899, JP-A-61-258790, and JP-A-62-105689. Those containing mainly saturated polyester are known.

However, when such a saturated polyester is used, an image having high dyeability, good gradation and good color reproducibility can be obtained, but in the recorded image, oil and fat components typified by fingerprints, chloride There is a problem that the plasticizer component contained in the vinyl sheet and the like, the image stability against heat and light is not sufficient.

[0004]

DISCLOSURE OF THE INVENTION The present invention, in the above recording system, has high dyeability to dyes and pigments, and
It is intended to provide a water-dispersed resin composition capable of forming an image-recorded material having excellent stability against an oil / fat component, a plasticizer component, heat, light and the like.

[0005]

That is, according to the present invention, 65 mol% or more of the glycol component is composed of ethylene glycol, has at least one kind of hydrophilic polar group, and has a glass transition temperature of 40 ° C. or more and 30% or more. Specific gravity at 1.degree.
It is composed of 25 or more polyester resins (A) and water (B), and the blending weight ratio thereof is (A) / (B) = 5 to 50/95.
The present invention relates to a water-dispersed resin composition for an image recording medium, which contains a resin composition of 50 to 50 as a main component.

In the water-dispersed resin composition of the present invention, it is necessary that the total glycol component contains ethylene glycol in an amount of 65 mol% or more, preferably 7.
It is preferable that the content is 0 mol% or more. When the content of the glycol is less than 65 mol%, the molecular gap of the resin becomes large, so that the oil and fat component and the plasticizer component are likely to permeate and diffuse into the resin, and the resulting image-recorded matter is disturbed.

A large number of glycol compounds can be used as the other glycol component used in less than 35% of the total glycol components. For example, 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, tricyclodecane dimethylol, bisphenol A ethylene oxide and propylene oxide adduct, hydrogenated bisphenol A
Ethylene oxide adduct and propylene oxide adduct of. 2,2-diethyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol and the like can be mentioned. Of these, preferred are diethylene glycol, propylene glycol, neopentyl glycol, polyethylene glycol, tricyclodecane dimethylol, and an ethylene oxide adduct of bisphenol A.

As the carboxylic acid component, terephthalic acid, isophthalic acid, orthophthalic acid, 2,3-naphthalic acid, 1,1,3-trimethyl-3-phenylindene-4,5-dicarboxylic acid, p- (hydroxy) Ethoxy)
Aromatic dicarboxylic acids such as benzoic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid and other unsaturated dicarboxylic acids, fumaric acid, maleic acid, tetrahydrophthalic acid and other unsaturated aliphatic dicarboxylic acids, 1 Alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid and tri- and tetracarboxylic acids such as trimellitic acid and pyromellitic acid can be used.

The polyester resin of the present invention must contain at least one hydrophilic polar group. As the hydrophilic polar group,

[0010]

[Chemical 1] (In the formula, M ₁ represents a hydrogen atom, an alkali metal, a tetraalkylammonium, or a tetraalkylphosphonium,
M ₂ represents a hydrogen atom, an alkali metal atom, a monovalent hydrocarbon group or an amino group, and R ₁ to R ₃ represent a hydrogen atom, an alkyl group having ₁ to 8 carbon atoms or an aryl group. ) Etc. can be mentioned.

Examples of the polar group compound used for introducing a hydrophilic polar group into the resin include the following compounds.

[0012]

[Chemical 2] Polycarboxylic acid which is an acid component of polyester, glyceric acid, dimethylolpropionic acid, N, N-dimethanolglycine, oxycarboxylic acid such as hydroxyethylbenzoic acid, aminocarboxylic acid such as diaminopropionic acid and diaminobenzoic acid, and the like Derivative.

[0013]

[Chemical 3] Nitrogen-containing alcohols such as N-methyldiethanolamine, 2-methyl-2-dimethylaminomethyl-1,3-propanol, 2-methyl-2-dimethylamino-1,3 propanediol and derivatives thereof.

[0014]

[Chemical 4] A pyridine ring-containing compound such as picolinic acid, dipicolinic acid, aminopyridine, diaminopyridine, hydroxypyridine, dihydroxypyridine, aminohydroxypyridine, pyridinedimethanol, pyridinepropanediol, and pyridineethanol, and derivatives thereof.

[0015]

[Chemical 5] Polycarboxylic acids such as 5-sodium sulfoisophthalic acid, 5-tetrabutylphosphonium, sulfoisophthalic acid and sodium sulfosuccinic acid and their derivatives, sodium sulfohydroquinone and alkylene oxide adducts, sodium sulfobisphenol A and alkylene oxide adducts.

[0016]

[Chemical 6] A hydrophilic polar group can be introduced into the polyester resin by adding and reacting these compounds at an arbitrary stage before the completion of polymerization.

The concentration of the hydrophilic polar group in the polyester resin of the present invention is 5 to 4000 eq. Per 10 ⁶ g of the resin. Range, preferably 10 to 3000 eq. Is good.
More desirably, 20 to 1000 eq. Is. The hydrophilic polar group concentration is 5 eq. If it is less than / 10 ⁶ , dispersion in water will be poor. On the other hand, the hydrophilic polar group concentration is 4000 eq. If it exceeds / 10 ⁶ , the resin becomes water-soluble and the water resistance of the coating film deteriorates.

The glass transition temperature of the polyester resin (A) in the present invention must be 40 ° C. or higher in consideration of heat resistance. If the glass transition temperature is less than 40 ° C,
Not only the heat resistance of the obtained image is significantly lowered, but also the image receiving papers cause blocking.

Further, in the polyester resin of the present invention, the specific gravity at 30 ° C. is required to be 1.25 or more from the viewpoint of suppressing permeation and diffusion of oils and fats and plasticizers into the resin, and preferably 1. It is 29 or more. When the specific gravity of the polyester resin is less than 1.25, oils and fats and plasticizers are easily permeated and diffused into the resin on which the image is recorded, and the recorded image is disturbed.

In the present invention, the polyester resin (A)
The blending weight ratio of water and water (B) is important in determining the coatability of the present water-dispersed resin composition, and (A) / (B) = 5 to 5
It must be 0/95 to 50. The amount of the polyester resin (A) contained in the water-dispersed resin composition is 5% by weight.
If it does not reach the above range or exceeds 50% by weight, the viscosity of the resin composition becomes too low or too high, which is not preferable. Further, it is preferable not to use water-soluble organic solvents such as alcohols and glycols, which are often used as water dispersion aids for polyester resins, from the viewpoint of reducing the miscibility of the following aqueous resin and / or aqueous additive. Examples of such water-soluble organic solvents include ethanol, isopropanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, and the like.

The water-dispersed resin composition of the present invention may be used as it is, but the crosslinking reaction may be carried out by any method. For example, a melamine resin, a polyisocyanate compound and its derivative, an epoxy compound, a peroxide, a thermal crosslinking system by using a redox radical initiator in combination, a radiation crosslinking system by ultraviolet rays, electron beams, γ rays, laser beams, etc., air. Examples thereof include a cross-linking system with water and oxygen in the interior, a bio-cross-linking system with an enzyme and the like.

Further, the water-dispersed resin composition of the present invention comprises
If necessary, other water-based resin solution and / or water-based resin emulsion or dispersion can be mixed.
Specific examples include polyolefin resins such as polyethylene and polypropylene, polyester resins, polyether resins, polyamide resins such as nylon 6, polystyrene, poly (meth) acrylic acid ester, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, etc. The vinyl resin, the cellulose resin, and many other resins as simple substances, copolymer solutions, emulsions, and dispersions.

The water-dispersed resin composition of the present invention can be used as it is, but in order to further improve the releasability at the time of thermal transfer and the light resistance of a recorded image, a fluorine resin, a silicone resin, an organic sulfone are used. Acid salt compounds, organic phosphate compounds,
Lubricating substances such as organic carboxylate compounds and UV absorbers,
Various additives such as radical scavengers, antioxidants and quenchers can be added. These additives are preferably water-soluble or water-dispersible from the viewpoint of miscibility with the water-dispersible resin composition of the present invention.

(Examples) The present invention will be specifically described below with reference to examples. In the examples, "parts" means "parts by weight" and "%" means "% by weight". Moreover, evaluation of various characteristics was performed according to the following methods. (1) Copolymer composition It was calculated from the integrated intensity ratio of ¹ H-NMR. (2) Number average molecular weight Calculated in terms of polystyrene by GPC. (3) Glass transition temperature It was measured by DSC. (4) Specific gravity of resin Measured at 30 ° C. by a float-sink method using an aqueous solution of calcium chloride. (5) Average particle size It was measured using Coulter N4 type (manufactured by Coulter).

(Production Example of Water-Dispersed Resin Composition) In an autoclave equipped with a thermometer and a stirrer, 268 parts of dimethyl terephthalate, 268 parts of dimethyl isophthalate, 71 parts of 5-sodium sulfoisophthalic acid, 381 parts of ethylene glycol, Charge 49 parts of diethylene glycol and 0.3 part of tetrabutoxy titanate, and add 2 at 150-220 ° C.
Transesterification was carried out by heating for 40 minutes. Then, the reaction system was heated to 250 ° C. in 10 minutes, the system pressure was gradually decreased to 0.3 mmHg or less after 25 minutes, and the reaction was continued for another 60 minutes under these conditions to obtain a pale yellow transparent polyester A. Next, 30 parts of this polyester A and 70 parts of water were charged into a container and stirred at 80 ° C. for about 3 hours to obtain a uniform white aqueous resin dispersion A. The properties of the resulting water-dispersed resin composition A are shown in Table 1. In addition, the compositions and characteristics of the water-dispersed resin compositions B to H obtained by the same method are shown in Table 1.
It was shown to.

[0026]

[Table 1]

Example 1 (Preparation of Image-Receiving Paper for Sublimation Transfer Recording) A water-dispersed resin composition A containing 8% by weight of an emulsion type silicone release agent with respect to the resin component was synthesized into a polypropylene composition having a thickness of 150 μm. It was applied to a paper (Yupo PPG-150 manufactured by Oji Yuka) using a wire bar so that a dry coating film of 4 μm could be obtained. Then, by drying at 120 ° C. for 2 minutes, an image receiving paper for sublimation heat-sensitive recording whose coated layer was a dye receiving layer was obtained.
The obtained image receiving paper was evaluated for print image density, plasticizer resistance, fingerprint resistance, heat resistance, and light resistance by the methods shown below.

(Evaluation of Printed Image Density) A thermal transfer sheet having a dye supplying layer and an image receiving paper were laminated so that the dye supplying layer and the dye receiving layer were in contact with each other. The sublimable cyan dye was transferred onto the image receiving paper by heating from the substrate side of the thermal transfer sheet with a thermal head (head output 0.7 W / dot, head heating time 8 ms, dot density 3 dots / mm). The obtained transferred image density was measured with a reflection densitometer (DM-600 manufactured by Dainippon Screen Co., Ltd.).

(Evaluation of plasticizer resistance) 1 cm ² of a vinyl chloride film having a thickness of 80 μm was adhered to the surface of the image receiving paper on which the cyan dye was transferred, and a load of 5 g was applied on the vinyl chloride film. After being left to stand at 24 ° C. for 24 hours, color loss of the cyan dye and traces of the film were observed. After aging, there is no film mark on the surface of the image-receiving paper and there is no change such as color loss. ○, there is no change in color, but film mark remains. △, color changes and film mark remains. .

(Evaluation of Fingerprint Resistance) The surface of the image receiving paper on which the cyan dye was transferred was strongly pressed with the thumb so that the fingerprint remained on the image surface. Agglomeration, color loss, and fingerprint residue were observed. After aging, those with no fingerprints on the surface of the image receiving paper and no change in color were evaluated as ○, those with fingerprints that did not change in color but remained as fingerprints were evaluated as ×, and those in which the dye aggregated on the image surface were evaluated as ×. .

(Evaluation of light resistance) The image receiving paper on which the cyan dye was transferred had an irradiation energy of 200 K at 40 ° C.
It was irradiated with a xenon lamp so as to have a value of J. The dye concentration retention rate (%) was calculated from the change in concentration before and after light irradiation. Dye density retention rate (%) = (density after light irradiation / density before light irradiation) × 100

(Evaluation of heat resistance (dark fading rate)) The image receiving paper on which the cyan dye was transferred was left to stand in an environment of 60 ° C. in the dark for 200 hours for aging. The dye density retention rate was calculated from the dye density before and after the test. Dye density retention rate (%) = (density after heating / density before heating) × 100 The evaluation results of the above measurement are shown in Table 2.

[0033]

[Table 2]

(Examples 2 and 3 Comparative Examples 1 to 5) Evaluation was performed in the same manner as in Example 1 except that B to H were used instead of the water-dispersed resin composition A. The evaluation results are shown in Table 2.

[0035]

INDUSTRIAL APPLICABILITY As described above, the specific water-dispersed resin composition of the present invention, when used for an image recording medium, has dyeability to dyes and pigments and durability to plasticizer, sebum, heat and light. It is excellent and industrially useful.

Claims (1)

[Claims] 1. A glycol component comprising at least 65 mol% of ethylene glycol, having at least one kind of hydrophilic polar group, and having a glass transition temperature of 40 ° C. or higher and 30.
Consists of polyester resin (A) having a specific gravity of 1.25 or more at ℃ and water (B), and the blending weight ratio is (A) /
(B) = 5-50 / 95-50 A water-dispersed resin composition for an image recording medium, which contains a resin composition as a main component.