JPH086060B2 - Ink solvent - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ink solvent, and more particularly to an ink solvent that imparts proper fluidity (rheological properties) to ink and is excellent in drying property.

[Problems to be Solved by Prior Art and Invention]

In general, inks used for high-speed printing and high-volume printing are required to have high printability and workability. It is known that these suitability is achieved by combining pigments, vehicles (resins, solvents), and auxiliaries to impart certain rheological properties to the ink.

By the way, conventionally, various studies have been conducted on the relationship between the rheological properties of ink and the composition of constituent substances of ink. However, the relationship between this rheological property and the vehicle that is one of the important constituents of the ink, especially the solvent, has not yet been fully investigated, and so far, high-speed, large-volume printing has not been performed. Ink with high performance (proper fluidity, drying property, misting resistance, etc.) has not been developed in response to technological advances.

[Means for solving problems]

The inventors of the present invention have conducted various studies for the purpose of developing a high-performance ink as described above, paying particular attention to the relationship between the rheological properties of the ink and the ink solvent, especially the petroleum solvent, I continued my research from various angles.

As a result, the naphthene content is as high as 30% or more, the aromatic content is as low as 2% or less, and the petroleum hydrocarbon solvent having an appropriate kinematic viscosity, viscosity index and pour point is high. It has been found that it enables the production of high performance inks. The present invention has been completed based on such findings.

That is, the present invention, the kinematic viscosity at 40 ℃ 0.5 ~ 500cSt,
It is intended to provide an ink solvent comprising a petroleum hydrocarbon having a viscosity index of 60 or more, a naphthene content of 30% or more, an aromatic content of 2% or less and a pour point of -20 ° C or less.

The petroleum hydrocarbon that is the solvent for the ink of the present invention is
Kinematic viscosity at 40 ° C is 0.5 to 500 cSt, preferably 2 to 200
cSt. Here, when the kinematic viscosity is less than 0.5 cSt, there is a problem that the evaporation property is high and the stability on the printing press is poor,
On the other hand, when it exceeds 500 cst, the drying property remarkably decreases, which is not preferable.

The petroleum hydrocarbon has a viscosity index of 60 or more, preferably 70 or more. When the viscosity index is less than 60, there is a problem that the resin is excessively swelled and the drying property is deteriorated.

Furthermore, this petroleum hydrocarbon has a naphthene content (%
C _N ) is 30% or more, preferably 30 to 50%. If the naphthene content is less than 30%, the compatibility with the resin or pigment that is the vehicle of the ink becomes poor, and the object of the present invention cannot be achieved.

The aromatic content (% C _A ) of the petroleum hydrocarbon must be 2% or less, preferably 1% or less. If the aromatic content exceeds 2%, the appearance of the solvent is deteriorated and it is not preferable in terms of safety.

The above-mentioned naphthene content (% C _N ) and aromatic content (% C _A ) are ring analysis values by the ndM method.

Further, this petroleum hydrocarbon has a pour point of -20 ° C or lower,
It is preferably -30% or less. If the pour point exceeds -20 ° C, there is a problem that the handling property and the pumping property are deteriorated when it is used in winter or in a cold region, which is unsuitable.

The petroleum hydrocarbon as the solvent for the ink of the present invention may have any of the above properties, but it is more preferable that the total acid value is 0.1 mgKOH / g or less.

Such petroleum hydrocarbons can be produced by various methods. For example, distillate obtained by subjecting paraffin-based crude oil, intermediate-based crude oil, or naphthene-based crude oil to atmospheric distillation to obtain a distillate obtained by further distilling under reduced pressure may be subjected to solvent dewaxing and further subjected to a two-stage hydrotreatment. By subjecting to hydrodewaxing and subsequent precision distillation if necessary, a petroleum hydrocarbon having a predetermined property can be obtained.

In the present invention, the above-mentioned petroleum hydrocarbon is used as a solvent for the ink, and the ink may be produced using this solvent by any known method known in the art. That is, a suitable pigment is added to the vehicle of the present invention containing a solvent and a resin, and if necessary, an auxiliary agent (wetting agent,
Make a color base by thoroughly kneading the mixture with a color-developing agent). The solvent of the present invention may be further added to this to dilute it into an ink.

The pigment used here varies depending on the desired color of the ink and the like, but those conventionally used widely can be used, and examples thereof include carbon black, disazo yellow, carmine 6B, and phthalocyanine blue.

The resin added as a vehicle includes natural and synthetic resins, and specific examples thereof include petroleum resin, rosin-modified phenol resin, alkyd resin and polymerized linseed oil.

Furthermore, fatty acid amines, esterified fatty acids and the like can be used as wetting agents, and natural wax, synthetic wax, clay, calcium carbonate and the like can be used as color developing agents.

〔Example〕

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Example 1 (Preparation of indigo color ink) Petroleum carbonization obtained by subjecting a distillate obtained by distilling an intermediate base crude oil to atmospheric distillation and vacuum distillation to a two-stage hydrogenation treatment and further hydrodewaxing treatment. Hydrogen solvent (kinematic viscosity at 40 ℃ 96cSt,
_A cyan ink was prepared as follows using a viscosity index of 85, pour point of −45 ° C.,% C _A 0.2,% C _N 32.0).

That is, first, 70 parts by weight of the above petroleum hydrocarbon solvent, 30 parts by weight of phthalocyanine blue, and 10 parts by weight of the standard ink additive.
A color base was prepared by thoroughly kneading with 20 parts by weight of the color base, and subsequently 24 parts by weight of the color base was added to 70 parts by weight of the petroleum hydrocarbon solvent to dilute the color base ink.

Comparative Example 1 (Preparation of Indigo Color Ink) Petroleum hydrocarbon solvent obtained by subjecting a distillate oil obtained by subjecting a naphthene-based crude oil to atmospheric distillation and vacuum distillation to a solvent extraction treatment (kinematic viscosity at 40 ° C) 102cSt, viscosity index 42, pour point −
_A cyan ink was prepared in the same manner as in Example 1 except that 20 ° C.,% C _A 6.0,% C _N 39.5) was used.

Example 2 (Preparation of Yellow Ink) 73 parts by weight of the petroleum hydrocarbon solvent obtained in Example 1 above, 30 parts by weight of Disazo Yellow and standard ink additive
Mix well with 10 parts by weight to make a color base,
Subsequently, 140 parts by weight of this color base was added to 95 parts by weight of the above petroleum hydrocarbon solvent and diluted to prepare a cyan ink.

Comparative Example 2 (Preparation of Yellow Ink) A yellow ink was prepared in the same manner as in Example 2 except that the petroleum hydrocarbon solvent obtained in Comparative Example 1 was used.

Example 3 (Preparation of Red Ink) 67 parts by weight of the petroleum hydrocarbon solvent obtained in Example 1 above, 28 parts by weight of Carmine 6B and 8 parts by weight of standard ink additive were sufficiently kneaded to form a color base, and subsequently, 120 parts by weight of this color base is added to the above petroleum hydrocarbon solvent 4
1 part by weight was added and diluted to prepare a red ink.

Comparative Example 3 (Preparation of Red Ink) A red ink was prepared in the same manner as in Example 3 except that the petroleum hydrocarbon solvent obtained in Comparative Example 1 was used.

Example 4 (Preparation of Black Ink) A black ink was prepared by adding 12 parts by weight of carbon black 12 and 3 parts by weight of a standard ink additive to 105 parts by weight of the petroleum hydrocarbon solvent obtained in Example 1 above.

Comparative Example 4 (Preparation of Black Ink) A black ink was prepared in the same manner as in Example 4 except that the petroleum hydrocarbon solvent obtained in Comparative Example 1 was used.

Evaluation of Ink Performance The performance of each ink prepared in the above Examples and Comparative Examples was evaluated as follows. The results are shown in Table 1.

Evaluation of Transferability With respect to the above ink, the amount of ink transferred to art paper (transfer rate) was measured with an RI tester with an ink amount of 4 g / m ² on the plate.

Evaluation of Dryability and Immersion Mitoshiki The NIA type automatic color developing machine was used to measure the dryness and immersion Mitoshiki of the above inks in accordance with JIS K-5702. For the evaluation of the drying property, immediately after coloring the art paper, a new paper was placed on it and rubbed with a blade, and this operation was repeated to determine the number of times (the number of papers) until the transfer disappeared. Here, the numerical value of the item of dryness in Table 1 is, for example, 2 + 1/3 indicates that the transfer was performed on two sheets of paper and that of the third sheet was transferred by 1/3.

In addition, the evaluation of the soaking property is based on the ink of the comparative example.

Measurement of tack value Using a THUING ALBER incometer, 32 ℃, 4
The L value of the above ink was determined under the condition of 00 rpm.

Evaluation of misting property Using an incommeter manufactured by THUING ALBER, 32 ° C, 1
The misting property of the above ink was evaluated under the condition of 200 rpm.
In addition, this evaluation was displayed based on the ink of the comparative example.

[Effects of the Invention] When the solvent of the present invention is used, the obtained ink has appropriate fluidity, drying properties and misting resistance, and is suitable for high-speed printing and mass printing.

Further, the solvent not only from the difficulty naphthene base crude availability, high yield can be easily produced even from paraffinic base crude and intermediate base crude, moreover% C for _A is smaller safety Is high.

Therefore, the solvent of the present invention can be effectively used as a solvent for various inks, and also has a great utility value as a solvent for various paints.

Claims (2)

[Claims] 1. A kinematic viscosity at 40 ° C. of 0.5 to 500 cSt and a viscosity index.
An ink solvent composed of petroleum hydrocarbons having a naphthene content of 60 or more, a naphthene content of 30% or more, an aromatic content of 2% or less and a pour point of -20 ° C or less. 2. The solvent for ink according to claim 1, wherein the petroleum hydrocarbon has a total acid value of 0.1 mgKOH / g or less.