JPS62162584A - Recording material for ink jet recording - Google Patents

Abstract

PURPOSE:To enable ink absorptivity, dot shape and color properties to be enhanced, by incorporating a rag pulp into the titled material in an amount not less than a specified value, and specifying the Stoeckigt sizing degree, air permeability and smoothness of the titled material. CONSTITUTION:An rag pulp is incorporated into a recording material in an amount of not less than 10wt%, preferably, no less than 20wt%, whereby an excellent dye-adsorbing capability for a dye used in an ink can be obtained, resulting in that blurring or feathering of the ink will not occur, and images excellent in dot shape and, particularly, color properties can be obtained. Further, the Stoeckigt sizing degree is set to be not higher than 40sec, preferably, not higher than 30sec, the air permeability is set to be not higher than 50sec, and the smoothness is set to be not higher than 40sec, whereby ink absorptivity is enhanced while maintaining more excellent ink fixability and high color properties.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a recording material, and more particularly to a recording material for inkjet recording for recording with aqueous ink.

(Prior Art) Inkjet recording methods include various ink (recording liquid) ejection methods, such as an electrostatic suction method, a method that applies mechanical vibration or displacement to the ink using a piezoelectric element, and a method that heats the ink to foam it. Recording is performed by using a method that uses the pressure to generate and fly ink droplets, and some or all of them adhere to a recording material such as paper, but it generates little noise and It is attracting attention as a recording method that allows high-speed printing and multicolor printing.

Conventionally, the recording material used in this ink-side recording method is paper, which is generally called plain paper.
Recording materials called 1M high to medium-quality paper and inkjet recording paper have been used.

Although commercially available medium-quality papers have excellent writing properties and printability, they have the following drawbacks when subjected to inkjet recording.

(1) During or after inkjet recording, if a part of the recording device or your finger touches the recording section, the ink will not be received quickly and the ink that has not been accepted will rub off.
Staining occurs and image quality is significantly degraded. Furthermore, the records may become illegible.

(2) After the ink adheres to the recording material, feather-like dots (feathering) occur, resulting in dots with extremely low roundness. For this reason, the dot shape is poor and a clear image cannot be obtained.

On the other hand, as the performance of inkjet recording devices improves and becomes more popular, various recording materials have been devised as recording materials for inkjet recording in order to obtain high-resolution, high-quality recorded images (for example, 59-35977, JP 58-132586, JP 52-74340
(see publication).

However, JP-A-59-35977 and JP-A-58
The recording materials described in Japanese Patent No. 132586 and the like are coated papers for inkjet recording that have high ink absorbency and excellent color development, but these recording materials have the following drawbacks.

(3) When writing on a recording material with a writing instrument such as a pencil or a fountain pen, the ink receiving layer is scratched and the writing cannot be done properly.

(4) When inkjet recording is performed on a recording material, mechanical friction between the recording material and the paper feeding part of the recording device causes
The coating layer peels off, so-called powder falling, which contaminates the recording device. In particular, if the fallen ink receiving layer adheres to the head of an inkjet recording device, it may cause clogging of the nozzles of the head.

Furthermore, the inkjet recording paper described in Japanese Patent Application Laid-open No. 52-74340 and the like has the following drawbacks when inkjet recording is performed.

(5) Low dot density.

(6) The dot periphery tends to be blurred, making it impossible to obtain a clear image.

(7) A phenomenon in which ink bleeds onto the back side of the recording surface, so-called bleed-through, occurs.

Conventional recording materials have the above-mentioned drawbacks, and the current situation is that no recording material that solves all of these drawbacks has been obtained.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned drawbacks, to provide a high-performance inkjet recording material that has rapid ink absorption, has excellent dot shape, and forms clear images with especially good color properties. The goal is to provide recording materials.

(Disclosure of the Invention) That is, the present invention contains a rag pulp of 10% by weight or more, a Steckigt sizing degree of 40 seconds or less, and an air permeability of 5.
This is a recording material for inkjet recording characterized by having a smoothness of 0 seconds or less and a smoothness of 30 seconds or less.

Next, to explain the present invention in more detail, the present inventor has discovered that as a recording material for inkjet recording using water-based ink,
As a result of intensive research in order to obtain a recording material that solves the drawbacks of the above-mentioned conventional techniques, a recording material containing specific components in a specific proportion or more and having strict specific physical properties has been found to be suitable for ink as a recording material for inkjet recording. It was discovered that the ink absorbs excellently, does not cause ink bleeding or feathering, provides an excellent dot shape, and provides a recorded image with particularly high color, fineness, and high resolution.

In other words, when the recording material contains 10% by weight or more, preferably 20ifi% or more of rag pulp, the presence of this rag pulp makes the paper layer structure very uniform, and it has excellent resistance to dyes in the ink. Dye adsorption ability is obtained,
As a result, there is no ink bleeding or feathering,
It provided an image with excellent dot shape and especially excellent color quality.

Further, in the recording material containing a specific amount of rag pulp, the Steckigt sizing degree is 40 seconds or less, preferably 3 seconds or less.
By setting the air permeability to 50 seconds or less, and the smoothness to 30 seconds or less, ink absorption improves while maintaining even better ink fixation and high color properties, and other ideals. A recording material with excellent performance could be obtained.

On the other hand, if the content of rag pulp is less than 10% by weight, even if the Steckigt sizing, air permeability, and smoothness are within the above-mentioned preferred ranges, the dot shape and color properties will be insufficient, resulting in fine and clear dots. I couldn't get a good image.

The above-mentioned recording material of the present invention can be used in a conventionally known method for obtaining paper, processed paper, synthetic paper, etc., in which at least 10% by weight, preferably 2% by weight, of cotton, hemp, etc.
It is obtained by making paper by adding it so that it accounts for 0% by weight or more, and the Steckigt sizing degree of the paper obtained in this way can be adjusted by the type and amount of the sizing agent and the combination of sulfuric acid band, etc. Performed according to known methods,
Air permeability can be adjusted by valve freeness, filler adjustment, calendering, paper making density, paper making speed, etc., and smoothness can be adjusted by valve freeness, filler, calendering, paper making density, etc. can.

In addition, when adding rag bulb in the above,
Conventionally known additives, such as sizing agents.

Extender pigments, various water-soluble to hydrophobic polymers, dispersants, fluorescent dyes, surfactants, water-resistant agents, etc. can also be added at the same time or at different times! ! It's natural.

The recording material of the present invention as described above can be used for fountain pens, felt-tip pens,
It is suitable not only for general writing using water-based ink, such as a ballpoint pen, but also as a recording material for inkjet recording, which uses water-based ink, and has the following effects.

(1) Water-based ink is highly absorbent, so ink sticks easily! F
After that, it immediately becomes the same state as if it were dried, so even if a part of the recording device or fingers or the like sticks together, it will not contaminate them or the recorded image will become dirty.

(2) When used for inkjet recording, the above (
In addition to the effect of 1), the ink dots are nearly perfect circles and have high density, and the dots do not bleed excessively or feather from the dots, making it possible to form clear and high-resolution images.

(3) The dye in the added ink has good fixing properties and exhibits excellent color properties.

Therefore, the recording material of the present invention is excellent not only as a general recording paper but also particularly as a recording material for inkjet recording.

Next, the present invention will be explained in more detail with reference to Examples, Comparative Examples, and Usage Examples. In addition, parts and percentages in the text are based on weight unless otherwise specified.

Example 1 and Comparative Example 1 After adding 10 parts of clay, 0.01 part of rosin sizing agent, and 0.08 part of sulfuric acid to 60 parts of LBKP, 0 parts of NBKPl, and 10 parts of cotton rag bulb, paper was made, first, and then oxidized. The surface size was treated with starch to obtain a recording material of the present invention having a basis weight of 64 g/m', a Steckigt sizing degree of 4 seconds, an air permeability of 25 seconds, and a smoothness of 15 seconds.

For comparison, the above example was repeated except that the rag bulb was not used, and the same Steckigt size,
A recording material having an air permeability and smoothness ratio of 12m was obtained.

Example 2 and Comparative Example 2 40 parts of LBKP, 35 parts of NBKP, 20 parts of cotton rag bulb and 5 parts of hemp rag bulb, 20 parts of calcium carbonate, 1 part of cationic starch and 0.0 part of alkyl ketene dimer
After adding 8 parts, paper was made, surface size treatment was performed with polyvinyl alcohol, and the paper size was 70 g/rr? A recording material of the present invention having a Steckigt size of 17 seconds, an air permeability of 38 seconds, and a smoothness of 21 seconds was obtained.

As a comparative example, the above Example 2 was repeated except that the rag bulb was not used, and a recording material for comparison with the same Stekicht sizing degree, air permeability, and smoothness was obtained.

Example 3 and Comparative Example 3 After adding 1 part of cationic starch, 0.02 part of rosin sizing agent and 0.12 part of sulfuric acid band to 20 parts of LBKP, 20 parts of NBKP, 60 parts of cotton rag valve and 20 parts of clay, paper was made, Basis weight 85g/m', Steckicht size 28
A recording material of the present invention was obtained with an air permeability of 18 seconds and a smoothness of 28 seconds.

As Comparative Example 3, Example 3 was slightly repeated except that the rag bulb was not used, and a recording material for comparison with the same Steckigt size, air permeability, and smoothness was obtained.

Comparative Example 4 In Example 1, the rosin sizing agent used was changed to 0.3 parts, and paper with a Steckigt sizing degree of 55 seconds was obtained, and this was used as a recording material for comparison.

Comparative Example 5 The recording material of the present invention of Example 1 was supercalendered to obtain paper with an air permeability of 85 seconds and a smoothness of 92 seconds, which was used as a recording material for comparison.

Example of Use For each of the recording materials of Examples 1 to 3 and Comparative Examples 1 to 5, an on-demand inkjet recording head (discharge Inkjet recording was performed using a recording apparatus having an orifice diameter of 60 gm, a piezo vibrator drive voltage of 70 V, and a frequency of 2.6 KHz.

Clear ink (composition) C, 1, Direct Yellow 86 2 parts diethylene glycol 20 parts polyethylene glycol #200 101 water
68 parts JLi2i (composition) C, 1, Acid Red 35 2 parts diethylene glycol 20 parts polyethylene glycol #200 10 parts water
68 parts above average! (Composition) C, 1, Direct Blue 86 2 parts diethylene glycol 20 parts polyethylene glycol #200 10 parts water
68 parts heavy ink (composition) C, 1, acid black 26 2 parts diethylene glycol 20 parts polyethylene glycol #200 10 parts water
Evaluation results of the recording materials of the 68-part Example and Comparative Example are shown in Table 1.

Each evaluation item in Table 1 was measured according to the following method.

(1) Ink fixation time was measured by measuring the time required for the ink to dry and stop adhering to the finger when touching the recorded image after recording.

(2) The dot density was calculated using Sakura Microdensidometer PD by applying JISK7505 to the printed microdots.
The black dots were measured using M-5 (manufactured by Konishiroku Photo Industry Co., Ltd.).

(3) To calculate the dot shape coefficient, measure the area of the dot using an image analysis device, assume a circle with the same area as the dot, calculate its circumference L1, and measure the length L2 of the dot's circumference. It was calculated using the following formula.

Dot shape factor = LI X100/L2 (%) (4
) In the panel test, a 1010x20 sample was created and 40 people (24 men, 16 women) were asked, "Which one has the best sharpness and contrast?" and the best one was given 5 points, and the worst one was given 5 points. Each item was given 1 point, and the total score was shown for comprehensive evaluation.

l Yonnie Length Shishin 2i ヱ】Ku 22L5x5” [Tomo 2 seconds 3 seconds 4 seconds
- G 1st job -1, 21, 31
, 2 and Σ"L-shaped" Lka 98% 92% 9
4% panel test +53 172 178 - Comparison - i ヱ danko' 2y j:f', IIJ 25 seconds
30 seconds 35 seconds do...t °1-
0.8 0.7
o, aL engineering)”, 85% 68% 7
2% Sho” 2l/? 2) 98 101 103-Rukoku- A base

Claims (3)

[Claims] (1) A recording material for inkjet recording containing 10% by weight or more of rag pulp and having a Steckigt sizing degree of 40 seconds or less, an air permeability of 50 seconds or less, and a Bekk smoothness of 30 seconds or less Material. (2) Claim No. 1 in which the rag pulp is 20% by weight or more and the Steckigt sizing degree is 30 seconds or less
The recording material for inkjet recording described in item ). (3) Claim No. 1 in which the base material of the recording material is paper
) The recording material described in section 2.