JPH0452230B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording material (recording paper) used in an inkjet recording method, and in particular to an inkjet recording material that has excellent ink color development and forms a recorded image with high resolution and water resistance. The present invention relates to a recording material and an inkjet recording method using the same. Recording methods using recording liquid have been common for a long time, such as writing with a fountain pen, but recently, a so-called inkjet recording method has also appeared, and recording liquid is also used here. The inkjet recording method generates small droplets of recording liquid using various operating principles, and performs recording by flying these droplets and adhering them to a recording material such as paper, but it generates little noise and can print at high speed. , is attracting attention as a recording method that allows multicolor printing. Water-based recording liquids are mainly used for inkjet recording in view of safety and printability. As the recording material used in this inkjet recording method, conventional paper has generally been used. However, as the performance of inkjet recording machines improves, such as faster recording and multicolor recording, recording materials for inkjet recording are also required to have more advanced characteristics. In other words, in order to obtain high-resolution and high-quality recorded images comparable to color photography, the recording material must (1) absorb ink as quickly as possible, and (2) avoid overlapping ink dots. (3) The diameter of the ink dot should not be larger than necessary; (4) The shape of the ink dot should be close to a perfect circle, and the surrounding area should be smooth. (5) The density of the ink dots is high and the periphery of the dots is not blurred; (6) The ink must have excellent color development. On the other hand, since the inkjet recording method uses water-based ink, there is a problem that the recorded images lack water resistance, and when exposed to water, the ink bleeds and becomes unreadable.There is also a need to solve this problem. It had been. However, the reality is that a recording material that satisfies all of these required performances has not yet been found. For example, the inkjet recording paper described in JP-A-52-74304 absorbs ink quickly, but the dot diameter tends to become large, the periphery of the dots tends to blur, and the size of the paper changes significantly after recording. It has the following drawbacks. It is an object of the present invention to provide a recording material for inkjet recording that satisfies the above-mentioned requirements and has particularly high resolution of recorded images and excellent water resistance. Another object of the present invention is to provide a recording material for inkjet recording which has improved coloring properties of ink and has excellent color properties. The above and other objects are achieved by the following invention. That is, in the present invention, the base material or the coating layer provided on the base material has a molecular weight of 1,000 to 200,000, and has the following general formula: (However, m and n are integers, m/(m+n) = 0.5 to 1
It is. ) 6 modified by introducing a dimelamino group shown in
- A recording material for inkjet recording characterized by containing nylon, and an inkjet recording method in which recording is performed by applying ink droplets to the recording material, wherein the recording material is a base material or a material on the base material. has a molecular weight of 1,000 to 200,000 in the coating layer provided, and has the following general formula: (However, m and n are integers, m/(m+n) = 0.5 to 1
It is. This is an inkjet recording method characterized by using a recording material containing 6-nylon modified by introducing a dimethylamino group shown in the following. The modified 6-nylon used in the present invention is typically represented by the following general formula. This modified 6-nylon has a structure in which the hydrogen atom at the alpha position of 6-nylon is replaced with a dimethylamino group, and the hydrophilicity and steric hindrance of the dimethylamino group destroys the crystallinity of 6-nylon, making it water-soluble. It has been given a gender. In the formula, m and n represent integers, m/(m+n)=0.5 to 1, and there is no particular restriction on the bonding mode between the dimethylaminated modified unit and the unmodified unit, and even those bonded randomly. They may also be connected in block form. By changing the substitution rate of dimethylamino groups, the water solubility and softening point of this modified 6-nylon can be changed. preferred from the viewpoint of water solubility. The molecular weight of the modified 6-nylon is suitably about 1,000 to 200,000, preferably about 1,000 to 5,000. On the other hand, the base material of the recording material of the present invention is typically paper, but cloth, resin film, synthetic paper, etc. can also be used as the base material. The method of manufacturing the recording material of the present invention by incorporating the modified 6-nylon as a base material includes, for example, a method of making paper using an aqueous solution of the modified 6-nylon in the papermaking process, or adding the polyamide during impregnation. However, there is a post-treatment method in which the base material is immersed in this, but any method may be used. The optimum concentration of the modified 6-nylon aqueous solution in these cases varies depending on the viscosity of the aqueous solution, but it is generally appropriate to use a concentration within the range of 0.05 to 2% by weight. The amount of the modified 6-nylon contained in the base material is suitably in the range of 0.05 to 2% by weight based on the base material, and if the amount of the modified 6-nylon is too large, ink absorption may occur. This is not preferable because it lowers the temperature. On the other hand, in the recording material of the present invention of the type containing the modified 6-nylon in the coating layer on the base material, the modified 6-nylon is added to the coating liquid, and this coating liquid is applied onto the base material. Manufactured by coating and drying. As other components of the coating liquid in this case, various conventionally known components may be added, such as finely divided silicic acid, clay, talc, diatomaceous earth, calcium carbonate, calcium sulfate, barium sulfate, titanium oxide, titanium oxide, etc. Inorganic pigments such as zinc, satin white, aluminum silicate, and lithopone; Water-soluble polymers such as starch, gelatin, casein, gum arabic, sodium alginate, carboxymethyl cellulose, polyvinyl alcohol, polyvinylpyrrolidone, and sodium polyacrylate; synthetic rubber latex Synthetic resin latex such as; organic solvent soluble resins such as polyvinyl butyral and polyvinyl chloride; and various additives such as dispersants, fluorescent dyes, PH regulators, antifoaming agents, lubricants, preservatives, and surfactants. I can do it. The amount of the modified 6-nylon added to the coating solution is suitably in the range of 0.03 to 20% by weight.
The coating liquid is applied onto the substrate in an amount of usually about 1 to 50 g/m ² (dry coating amount) by a known method (for example, a roll coater method, a blade coater method, an air knife coater method). Preferably 2-30
Apply approximately g/ ^m2 (dry coating amount). The recording material of the present invention, which contains the modified 6-nylon in the base material or the coating layer provided on the base material in this way, allows the ink to be quickly absorbed into the inside of the recording material, producing a different color of the recording liquid. Even if the recording liquid adheres to the same location repeatedly within a short period of time, there is no flow out or seepage phenomenon of the recording liquid, and a clear image with high resolution can be obtained. Furthermore, it exhibits excellent properties in terms of water resistance and color development, and is suitable as a recording material for inkjet recording. Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 A coating composition was prepared based on the following composition using modified 6-nylon (manufactured by Toray Industries, Inc.) with a dimethylamino group substitution rate of 100%. Fine powder silicic acid 100 parts by weight Polyvinyl alcohol 50〃 Modified 6-nylon 0.5〃 Water 500〃 On the other hand, general high-quality paper (basis weight 65 g/m ² ) with a sizing degree of 35 seconds based on JIS P8122 was used as the base material. , dry coating amount of the above coating composition on this base material
It was coated at a rate of 20 g/m ² using a blade coater method and dried by a conventional method to obtain a recording material. Color inkjet recording was performed on this recording material using the following four colors of ink, and the recording characteristics were evaluated. Yellow ink (composition) CI acid yellow 23 2 parts by weight diethylene glycol 30 〃 Water 70 〃 Magenta ink (composition) CI acid red 92 2 parts by weight diethylene glycol 30 〃 water 70 〃 Cyan ink (composition) CI Direct Blue 86 2 parts by weight diethylene glycol 30 〃 Water 70 〃 Black ink (composition) CI Direct Black 19 2 parts by weight diethylene glycol 30 〃 Water 70 〃 Table 1 shows the evaluation results of the recording properties of the recording material.
The degree of bleeding was determined by measuring the diameter of the printed dot using a stereomicroscope, and expressed by how many times larger the diameter of the printed dot was than that of the ink droplet. Water resistance was evaluated by immersing the recording material in running water for 3 hours, measuring it using a Macbeth densitometer after immersion, and comparing the optical density (OD) with the OD value before immersion. In addition, the color properties are measured using a colorimetric colorimeter ND-1001-
The results measured using DP (manufactured by Nippon Denshoku Kogyo Co., Ltd.) are shown after being converted into Munsell values. Example 2 General paper (basis weight 70 g/m ² ) with a size degree of 0 seconds was immersed in a 1% aqueous solution of modified 6-nylon (manufactured by Toray Industries, Inc.) with a dimethylamino group substitution rate of 74%, and dried. A recording material impregnated with about 0.5% by weight of the modified 6-nylon based on the base material was obtained. Table 1 shows the results of evaluating this recording material in the same manner as in Example 1. Comparative Example 1 A recording material was prepared in the same manner as in Example 1, except that modified 6-nylon was not added to the coating composition. The recording characteristics were evaluated in the same manner as in Example 1, and the results are shown in Table 1. Comparative Example 2 The base material used in Example 2 was used as a recording material without any treatment. The recording characteristics were evaluated in the same manner as in Example 1, and the results are shown in Table 1. 【table】

Claims (1)

[Claims] 1. In the base material or the coating layer provided on the base material, 1000
It has a molecular weight of 200,000 to 200,000 and has the following general formula: (However, m and n are integers, m/(m+n) = 0.5 to 1
It is. ) 6 modified by introducing a dimelamino group shown in
- A recording material for inkjet recording characterized by containing nylon. 2. In an inkjet recording method in which recording is performed by applying ink droplets to a recording material, as the recording material, 1000 ml of ink is added to the base material or a coating layer provided on the base material.
It has a molecular weight of 200,000 to 200,000 and has the following general formula: (However, m and n are integers, m/(m+n) = 0.5 to 1
It is. 1. An inkjet recording method characterized by using a recording material containing 6-nylon modified by introducing a dimethylamino group represented by the following formula.