JPH11254816A - Manufacture of ink jet recording material and ink jet recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a really new manufacture of ink jet recording material having a fine ink drying property, a superior vividness of recorded images, and also surface glossiness. SOLUTION: The recording material is formed by applying a mixture of three components such as a prepolymer component obtained by reacting a polyol and a polyisocyanate (1), a tertiary amine compound (2), and a halogen compound (3). After that, reaction is caused thereto so as to form on the base material surface a polymer having ionene introduced in its molecular skeleton.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a recording material used for ink jet printing or copying using a jet printer with aqueous ink or the like, and a recording material for ink jet obtained by the production method.

[0002]

2. Description of the Related Art Ink jet recording is a method in which ink is ejected from nozzles and adheres to a recording medium to perform recording. In recent years, with the spread of electronic still cameras and computers, the technology for recording these images on paper or the like has rapidly developed.In particular, the inkjet method is easy to use in full color and the printing noise is low. In recent years, it is developing rapidly.

[0003] If the ink of the ink jet system is of the solvent type, it dries quickly and the nozzles are easily clogged.
Since the solvent type has a problem in safety to the human body, an aqueous ink is generally used.

[0004] The aqueous ink used in the ink-jet system is an ink using a pigment or a dye or both as a colorant and a water-soluble dispersant.
The target color is expressed by the overlapping of the four black inks.

[0005] As a recording material used in the ink jet system, a material suitable for a place of use (for example, outdoors or indoors), a use method, and the like is selected. For example, a thermoplastic film, a translucent film, paper , Cloth and the like are used.

Usually, a polyhydric alcohol is often added to the aqueous ink in order to prevent nozzle clogging and improve ejection stability. As a recording material for inkjet recording, the ink should be rapidly absorbed (that is,
That the ink dries quickly), that the recording liquid attached later does not flow into the previously attached dots when the ink dots overlap, that the dot shape is close to a perfect circle and that the density is high, The components are required to have excellent color developing properties, excellent ink fixability, high glossiness on the surface, high whiteness, and the like.

Conventionally, most of recording materials used for observing surface images have used a method in which ink is absorbed into porous voids to fix the recording material. JP-A-8-1142
No. 1 discloses a technique of forming an ink absorbing layer using a coating liquid obtained by mixing polyvinyl pyrrolidone, a water-insoluble acrylic resin, and porous silica and organic fine particles with a solvent.

However, these are not glossy on the surface of the recording material due to their porous nature, and it is necessary to provide a non-porous ink-receiving layer in order to obtain glossiness. Had the disadvantage that the drying property was remarkably poor.

Japanese Patent Publication No. 3-42590 discloses an ink receiving layer containing a reaction product of an isocyanate compound and a polyether polyol. Generally, the ether bond itself has a high hydrophilicity and therefore has excellent water-absorbing property, but as in the examples described in this publication, when the porous body is not contained, the ink is dried more than when the porous body is contained. As a result, the drying performance was poor and the drying speed was not sufficient.

[0010]

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, the present invention has excellent ink drying properties and excellent recorded image clarity,
Further, it is an object of the present invention to provide a completely new method for manufacturing a recording material for ink jet recording, which has excellent surface gloss, and to provide the recording material for ink jet recording.

[0011]

According to the present invention, there is provided a method for producing a recording material for ink jet recording, comprising: a prepolymer component (1) obtained by reacting a polyol with a polyisocyanate; a tertiary amine compound (2); Halogen compound (3) 3
A mixture of the two components is applied to a substrate and then allowed to react,
The present invention is characterized in that a polymer in which ionene is introduced into a molecular skeleton is formed on the surface of a substrate. Further, the inkjet recording material of the present invention is an inkjet recording material obtained by the above-described manufacturing method, wherein a polyurethane elastomer in which ionene is introduced into a molecular skeleton is formed on a substrate surface. It is a feature. Hereinafter, the present invention will be described in detail.

As used herein, "ionene" refers to an ionic segment. The gist of the inkjet recording material of the present invention resides in that a polyurethane elastomer in which ionon is introduced into a molecular structure is used.

The recording material for ink jet of the present invention comprises a polyurethane elastomer. The polyurethane elastomer is obtained by reacting and curing a polyol, a polyisocyanate and a crosslinking agent. The polyol may be a hydrophobic ester component or a hydrophilic ether component, and can be appropriately adjusted depending on the type of ink and the drying property.

In general, dye-type inks exhibit anionic properties. Therefore, the present inventors have noticed that if a cationic structure can be introduced as a cross-linking agent, an anionic ink can be stably fixed, and arrived at the idea that the above object can be achieved by introducing Ionene. Have reached the present invention.

The recording material for ink-jet recording of the present invention has a stable and uniform existence as compared with the case where a quaternary ammonium salt or the like is mixed as an additive because the cationic structure is present in the molecular chain. Since the ink is fixed more uniformly, the image becomes clearer.

This results in an isocyanate content,
The amount of the quaternary ammonium salt in the cross-linking agent can be arbitrarily adjusted, so that not only the fixing property can be easily adjusted according to the type of the ink, but also the physical properties of the ink receiving layer according to the base material can be adjusted. it can.

The fixing property of the anionic ink is related to the cation concentration of the recording material, and when the density is higher than a certain level, the fixing property is remarkably excellent, the image becomes clearer, and the ink absorbing and drying property is also improved. In addition, since the cation concentration can be adjusted depending on the type of the ink, it is possible to cope with any anionic ink.

The present invention is characterized in that Ionene having a repeating unit is introduced into polyurethane. It is preferable that the ionon repeating unit contains a quaternary nitrogen.

The polyurethane according to the present invention can easily be selected for the polyol component forming the soft segment structure, and can be designed in a wide range. It can be freely designed from hydrophobic to hydrophilic.

In the present invention, the ionene segment is introduced to improve the cation concentration in the polyurethane in order to enhance the fixing property of the ink.
Both glossiness and ink absorption drying property can be achieved.
Further, by adjusting the hydrophilicity of the polyol component, even a very thin film can be used.

In the polyurethane elastomer having an ionene structure of the present invention, an isocyanurate crosslink is used as a crosslink structure for the purpose of improving the physical properties as an ink jet recording material, mainly the tackiness after coating and improving the ionene concentration. Therefore, the synthesis is preferably performed in the presence of a solvent.

The method for producing the ink-jet recording material of the present invention includes a prepolymer component (1) obtained by reacting a polyol with a polyisocyanate, a tertiary amine compound (2), and a halogen compound (3). A method in which a mixture of the three components is applied to a substrate, and then reacted and cured by heating as necessary, thereby forming a polymer having ionon introduced into a molecular skeleton on the surface of the substrate. it can.

In this method, since the main agent and the curing agent are mixed and then cured, the pot life of each liquid can be extended for a long time, and the liquid loss can be minimized. Therefore, the manufacturing process of the ink jet recording material is facilitated, and the ink jet recording material can be manufactured at low cost.

Further, as another method for producing a recording material for ink jet recording according to the present invention, three components of an amine-terminated prepolymer component (4), a tertiary amine compound (2), and a halogen compound (3) are used. Can be applied to a substrate, and then reacted to form on the substrate surface a polymer in which ionene has been introduced into the molecular skeleton.

At this time, a mixture obtained by mixing a prepolymer component (4) having an amine terminal and a tertiary amine compound (2) as a main component and a halogen compound (3) as a curing agent is prepared. May be applied to the substrate. The method for producing the amine-terminated prepolymer component (4) is not particularly limited, and examples thereof include a method of reacting a polyol with a polyisocyanate and then reacting an amine having a hydroxyl group.

The polyurethane having a cationic structure according to the present invention is prepared by first reacting a polyol with an isocyanate to form a prepolymer having isocyanate groups at both ends, and then having an OH group capable of reacting with isocyanate at one end, and having an ionene. A tertiary nitrogen which can be quaternized by a reaction with an alkyl halide so as to react with the segment and is reacted with 2-dimethylaminoethanol having an isocyanurate-catalyzing action to react with one end amine fragment and one end isocyanate A prepolymer of nurate was used as a main ingredient. As described above, the main agent is preferably synthesized in advance in the presence of a solvent because it has an isocyanurate bond which is a cross-linking point.

As a curing agent, N, N, N, which forms an ionomer segment with a base material having a terminal amine fragment.
N ', N'-tetramethyl-1,6-diaminohexane (TDH) and 1,6-dibromohexane (DB
H) is added and stirred to coat the substrate. The curing reaction of the coated substrate is accelerated by heating, and a polymer in which ionene is introduced into the molecular skeleton can be formed in a short time.

If necessary, an amine-terminated prepolymer (4) and TDH may be added as a curing agent, followed by coating after stirring. By doing so, since the ionene segment can be introduced later, a polyurethane elastomer having excellent properties as an ink jet recording material as described above in order to improve the cation concentration in the polyurethane structure is used. Obtainable.

The repeating unit of Ionene is not particularly limited, but examples thereof include those represented by the following formula.

[0030]

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Various additives such as a dispersant, a reaction regulator and an antifoaming agent can be added to the polyurethane elastomer as required. The solvent solution thus manufactured is used as an ink receiving layer. The ink receiving layer can be manufactured by coating a base material by various methods and then drying by heating. The thickness of the ink-receiving layer on the substrate can be usually adjusted by applying a coating liquid on the substrate such that the thickness after drying is about 1 to 200 μm. The thickness of the ink receiving layer after drying is more preferably 10 to 50 μm.

[0032]

The present invention will be described below in detail with reference to examples of the present invention, but the present invention is not limited to these examples. Example 1 Polytetramethylene glycol having a molecular weight of 1,000 (PTMG-1000, manufactured by Sanyo Kasei Kogyo Co., Ltd.) as a synthetic polyol of the main agent
And polyoxyethylene glycol having a molecular weight of 1000 (manufactured by Sanyo Chemical Industries, Ltd., PEG1000) were blended at a molar ratio of 7: 3. Next, 4,4′-diphenylmethane diisocyanate (MDI, manufactured by Nippon Polyurethane Industry Co., Ltd., Millionate MT) was added so that the molar ratio of NCO / OH became 2/1, and the mixture was stirred at 65 ° C. under a nitrogen atmosphere. An isocyanate-terminated prepolymer was obtained. The end of the reaction
It was confirmed by the residual NCO group concentration by the amine equivalent method.

Then, dimethylformamide (DMF) was added to the isocyanate-terminated prepolymer in the presence of polyol 0.1.
20 mol per 1 mol, 2-dimethylaminoethanol (DAE) is added so that the molar ratio of NCO / OH becomes 2/1, and about 90 °
The mixture was heated and stirred for 1 minute to obtain an amino-terminated prepolymer.
The end of the reaction is the absorption of NCO by FT-IR 2
Confirmed by disappearance of absorption at 275 cm ^-1 .

Formation of Ionene Polymer Surface -N (CH ₃ ) ₂ / TDH / DBH = 1/1 so that the N ⁺ concentration of the obtained ionene polymer is 2% by weight.
/1.5 mol ratio and stirred for about 1 minute. This was coated on a general copy paper by a bar coater method to form a coating film having a thickness of 20 μm.
Then, the composition was heated and cured at 100 ° C. for 10 minutes, and dried to obtain an inkjet recording material having an ionene polymer surface.

Example 2 -N (CH ₃ ) was adjusted so that the N ⁺ concentration was 1.5% by weight.
A recording material for ink jet was obtained in the same manner as in Example 1 except that ₂ / TDH / DBH was added at a molar ratio of 2/1/2.

Example 3 In synthesizing an isocyanate-terminated prepolymer, a polyol was used as a polyethylene adipate having a molecular weight of 1,000 (Nipporan 400 manufactured by Nippon Polyurethane Industry Co., Ltd.).
A recording material for ink jet was obtained in the same manner as in Example 1 except that step 2) was performed. Example 4 An inkjet recording material was obtained in the same manner as in Example 1 except that THD was preliminarily blended with the main agent.

Comparative Example 1 The prepolymer was synthesized in the same manner as in Example 1. Thereafter, this prepolymer was dissolved in DMF, and the weight ratio of 1,4-butanediol to trimethylolpropane was 60/4.
0 was added so that the NCO / OH molar ratio was 1.0, and an ink-jet recording material (composed of polyurethane having no ionene structure) was obtained in the same manner.

Comparative Example 2 An ink-jet recording material (comprising a polyurethane having no ionene structure) was obtained in the same manner as in Comparative Example 1 except that the polyol used was the polyethylene adipate used in Example 3. . Comparative Example 3 After synthesizing an amine-terminated prepolymer, N ⁺
As concentration of 2 _{wt%, -N (CH 3) 2} / TD
H / DBH = 1/1 / 1.5 molar ratio, added approximately
The mixture was reacted for 5 hours and coated in the same manner by a bar coater method. The liquid became cloudy in one hour, and the viscosity increased, so that coating could not be performed.

Examples 1-4 prepared as described above,
With respect to the inkjet recording materials of Comparative Examples 1 to 3, the glossiness was evaluated before printing, and after printing using a commercially available A4 size inkjet printer, the evaluation of the ink drying property and the coloring property was performed. Performed by the method. The results are shown in Table 1.

Evaluation method 1) Glossiness: According to JIS K 7105, the reflectance at 60 degrees of incident light and reflected light was determined using a gloss meter VGS-1D manufactured by Nippon Denshoku Industries Co., Ltd. 2) Ink drying property: After printing, the ink was left at 24 ° C. and 50% RH, and the time required for ink to be removed by touching with a hand was measured. 3) Color development: After printing, visual observation was made, and those with sufficient color development were evaluated as ○, and those with insufficient color development were evaluated as x.

[0041]

[Table 1]

[0042]

According to the present invention, a recording material for ink-jet recording which has the above-mentioned structure, provides a clear image excellent in glossiness and coloring, and also has high drying properties (absorptivity). Can be provided.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Noriko Hiraoka 1-4-52-1107 Nameki, Nagasaki-shi (72) Takako Terada 17-18 Hashiguchicho, Nagasaki-shi

Claims (4)

[Claims] 1. A mixture of a prepolymer component (1), a tertiary amine compound (2), and a halogen compound (3) obtained by reacting a polyol with a polyisocyanate is applied to a substrate. And then reacting to form, on the surface of the base material, a polymer in which ionene is introduced into the molecular skeleton. 2. An amine-terminated prepolymer component (4),
Tertiary amine compound (2) and halogen compound (3)
A method for producing a recording material for ink-jet recording, comprising applying a mixture of the three components to a substrate, and then reacting the mixture to form a polymer having ionon introduced into a molecular skeleton on the surface of the substrate. 3. The inkjet coating according to claim 2, wherein the amine-terminated prepolymer component (4) is mixed with the tertiary amine compound (2), and then the halogen compound (3) is further added to prepare the mixture. Manufacturing method of recording material. 4. An ink-jet recording material produced by the method for producing an ink-jet recording material according to claim 1, wherein a polyurethane elastomer in which ionene is introduced into a molecular skeleton is provided on a surface of the base material. A recording material for ink jet, characterized in that it is formed.