JPH0745642B2 - Solvent composition for printing ink - Google Patents

Description

TECHNICAL FIELD The present invention relates to a solvent for printing ink.

Particularly, it relates to a non-toxic solvent most suitable for lithographic printing ink.

[Prior Art and its Problems] Conventionally, various solvents having a boiling point of 230 to 300 ° C. have been used as a solvent for printing ink, particularly a solvent for lithographic printing ink. A typical example is a mineral oil hydrocarbon solvent. Mineral oil-based solvents have the following problems. That is, since mineral oil usually contains 20 to 30% of aromatic components, there is a problem of toxicity, and since it is a co-product, it has a wide boiling point range and contains heavy components, so that it is inferior in dryness after printing. .

Among the aromatic components, benzene, toluene, and xylene have a bad effect on the human body, and thus there is a strong demand for a solvent having a low content of these. In particular, if the benzene content exceeds 1 vol% according to the Ordinance for Prevention of Disturbance of Specific Chemical Substances by the Ordinance of the Ministry of Labor, and if the total amount of toluene and xylene exceeds 5 wt% under the Ordinance for Prevention of Organic Solvent Poisoning of the same Ordinance, it has an adverse effect on the human body. Is emphasized and its use is severely restricted. In addition, these compounds are subject to regulation by the "Standards for Dangerous Toxicity of Chemical Substances" established by the US Department of Labor, and it is obligatory to indicate the presence of these compounds.

In order to solve such a problem, it has been attempted to mix non-toxic paraffins, but the paraffins easily solidify at low temperature (solidify at 5 to 7 ° C.) and adjust the fluidity of the varnish. However, there are problems such as difficulty in removing the resin and insufficient dissolving power of the resin. Further, it has been attempted to use naphthenes in combination, but if the naphthene content is increased, the solubility of the resin will be lower than that of the aromatic hydrocarbon and the gloss of the printed matter will be deteriorated.

[Object of the Invention] An object of the present invention is to provide a solvent that is non-toxic and satisfies all the required properties of odor, resin solubility, gloss of printed matter, high-speed printability, and storage stability of varnish. To do.

[Means for Solving the Problem] The object of the present invention is to provide naphthenes 30 to 80 wt%, isoparaffins 15 to 40 wt%, n-paraffins 0 to 20 w%, tetralines 2 to 15 wt%, and aromatic hydrocarbons. Achieved by a solvent composition for printing inks according to the invention having a boiling point in the range of 230 to 300 ° C. consisting of 0 to 10 wt%.

Hereinafter, the present invention will be described in more detail.

[Constitution of Invention] [Component] The components of the solvent of the present invention are as follows.

(A) Naphthenes 1 to 3 rings are the main components. It is preferable that the main component contains approximately equal amounts of monocycle and bicycle. Naphthenes contribute to improving the solubility of resins and pigments and improving the gloss of printed materials. The content of naphthenes is 30 to 80% by weight. When it is less than 30%, the dissolving power is insufficient, and when it exceeds 80%, the odor is not preferable.

(B) Isoparaffins Isoparaffins contribute to the improvement of odor and low temperature characteristics. The content of isoparaffins is 15-40wt%,
If it is less than 40%, the improvement effect cannot be obtained, and if it exceeds 40%, the dissolving power of the resin decreases.

(C) n-paraffins n-paraffins contribute to the odor improving effect. Content is 0
The content is preferably up to 20% by weight, and when it exceeds 20%, the dissolving power of the resin decreases and the viscosity of the varnish at low temperature increases, so the content is preferably as low as possible.

(D) Tetralins As tetralins, alkyltetralin is the main component. Tetralins contribute to improving the dissolving power of resins and pigments. The content is 2 to 15% by weight, and if it is less than 2%, the dissolving power is insufficient, and if it exceeds 15%, the same drawbacks as aromatic hydrocarbons, that is, odor and the like appear.

(E) Aromatic Hydrocarbons Aromatic hydrocarbons are mainly composed of aromatic hydrocarbons such as alkylbenzene and alkylnaphthalene, which are not subject to legal regulation, and substantially benzene, toluene, and xylene, which are subject to legal regulations. It is not included. In addition, it does not include naphthalene and biphenyls, which are not subject to legal regulations but may cause problems in terms of safety. Although this component contributes to the dissolving power, it is preferably as small as possible from the viewpoint of toxicity and odor, and the content is 0 to 10 wt%, more preferably 0 to 5 wt%.

The present invention is intended to exert excellent performance by reducing the content of aromatic hydrocarbons as much as possible to solve the toxicity problem and at the same time, by synergistically working with other components, each component and its content. Has important significance.
In particular, the inclusion of tetralins as an essential component is indispensable for achieving the effects of the present invention.

[Boiling point]

The boiling range of the solvent of the present invention is 230 to 300 ° C. If it contains less than 230 ° C, the aromatic components that are subject to the above regulations will be mixed in, and the evaporation rate at the time of drying during printing will be too fast, which will increase the viscosity of the ink and cause a paper breakage phenomenon. Cannot print. When it exceeds 300 ° C, the drying speed becomes slow and the printing speed cannot be increased. A more preferable boiling point range is 245 to 280 ° C.

[Solvent manufacturing method]

The solvent of the present invention can be obtained by mixing each component compound, but it is not always economical to necessarily mix or synthesize each component at a predetermined ratio.

The preferred method for producing the solvent of the present invention is as follows.

A petroleum-based fraction, preferably a kerosene fraction having a boiling point range of about 150 to 300 ° C, is subjected to a hydrogenation treatment, and most of the aromatic components are nuclear hydrogenated to be softened into naphthenes and tetralins, and at the same time are impurities. Compounds such as sulfur and nitrogen are desulfurized and denitrified by hydrogenation. After removing all or part of n-paraffins from this product with a molecular sieve or the like, distillation is performed to obtain a solvent fraction having a desired boiling range and composition.

The degree of hydrogenation is adjusted to contain a desired ratio of naphthenes and tetralins. Hydrogen addition pressure is 30-100k
It is preferably carried out at g / cm ² and a temperature of 100 to 300 ° C. in the presence of a known hydrogenation catalyst such as a Group VIII transition metal of the periodic table. The reaction system may be either a batch system or a continuous system.

The composition can be adjusted by adding appropriate components to the solvent fraction thus obtained. This method is extremely economical as the use of by-products in the method for producing n-paraffins that are produced in large quantities as raw materials for synthetic detergents.

〔ink〕

(A) Kind of Ink The solvent of the present invention can be applied to various printing inks, but it is preferably used for lithographic ink, especially for rotary ink.

(B) Ink resin Various known resins can be used as the ink resin. For example, petroleum resin and its modified product, rosin-modified phenol resin, rosin-modified alkyd resin, fatty acid or oil-modified alkyd resin and the like can be used alone or in combination of two or more depending on the purpose.

(C) Other components for inks Linseed oil, tung oil, soybean oil, dehydrated castor oil and the like and drying oils such as polymers and modified products thereof, semi-drying oils and the like can be used.

As the colorant, various pigments such as organic pigments, inorganic pigments, fluorescent pigments, carbon black, and metal powder can be used.

In addition to the above, various additives conventionally used for inks such as wax, grease, thickener, stabilizer, dispersant, filler, and other known additives can be used.

[Action and Effect of the Present Invention] The solution of the present invention exerts an effect that cannot be obtained by each component alone due to the synergistic action of each component.

That is, naphthenes increase the dissolving power of resins and pigments and improve the gloss of the printed surface, and isoparaffin solves the disadvantages of n-paraffins such as lack of dissolving power and poor flowability at low temperature. Synergistically improve the dissolving power of resin and pigment, while suppressing aromatic hydrocarbons as much as possible to solve toxicity, odor and safety, and n-
Paraffins were reduced to solve the drawbacks in solvency and low temperature fluidity.

The solvent of the present invention has the following advantages as compared with conventional ink solvents.

(A) Since it does not substantially contain aromatic substances such as benzene, toluene, and xylene, which are subject to legal regulations, environmental pollution problems do not occur. There is no problem of odor.

(B) As compared with the conventional product in which the solvent power was maintained by an aromatic hydrocarbon which has a problem in toxicity, a high solvent power can be achieved in spite of the reduction in aromaticity or non-aromatization.

(C) Compared with conventional products which have low odor and low toxicity due to the addition of n-paraffins, the solvent itself and the ink varnish do not have high viscosity and low fluidity at low temperature.

(D) The gloss of the printed matter is excellent.

(E) Since the drying speed is high, the printing speed can be improved.

(F) Hydrogenation of petroleum fraction, separation of n-paraffins,
Since the solvent having the optimum composition can be obtained by a series of steps by distillation, the complicated work of preparing a plurality of components and mixing them as in the conventional case is unnecessary. In particular, it is extremely economical when using a by-product in the production of n-paraffins, which is produced in large quantities as a raw material for synthetic detergents and the like.

(G) In relation to the safety of (a) above, the US Occupational Safety and Health Administration (OSHA, Occupation, Safety and Health Admini
stration) Biphenyl and naphthalene, which are regulated by the established "standards of hazards of chemical substances, etc." and which are obligatory to be labeled, are excluded from the law because the composition of the present invention hardly contains them.

[Examples] Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples without departing from the gist of the present invention.

Throughout this specification, all temperatures are degrees Celsius and parts and percentages are by weight unless otherwise stated.

(A) Solvent and its production Example 1 Kerosene fraction (65 wt% of paraffins, 25 wt% of naphthenes, 10 wt% of aromatics) having a boiling range of 150 ° C to 280 ° C obtained by distillation of crude oil was added at 280 ° C, 90 kg / As a catalyst under the condition of cm ² ,
Hydrogenation was performed using a nickel-tungsten catalyst, and the obtained product was supplied to a separation column packed with a molecular sieve, and n-
Paraffins were removed. The fraction depleted in n-paraffins was then distilled to obtain a solvent fraction having a boiling point of 243-275 ° C. The composition and properties of this solvent are shown in Table 1.

Example 2 Using a kerosene fraction having properties different from those of Example 1, a solvent having the composition and properties shown in Table 1 was obtained by the same operation as in Example 1.

Comparative Example 1 Tetralin content was 0 wt% for hydrogenation in Example 1.
It was obtained by performing under the following conditions. Table 1 shows the composition and properties of the solvent.
Shown in.

Comparative Example 2 A commercially available mineral oil solvent (boiling point 235 to 290 ° C) and n-paraffin (boiling point 244 to 265 ° C) were mixed in equal amounts. The composition and properties of this mixed solvent are also shown in Table 1.

Comparative Example 3 A commercially available mineral oil-based solvent (boiling point 235 to 290 ° C.) was used. The composition and properties are shown in Table 1.

(B) Solvent evaluation test The test method described in Table 2 is as follows.

(A) Odor Total male and female trained in advance for odor sensory test
In the air-conditioned room, 10 people judged the odor of each solvent in 5 grades according to the following criteria. The result is shown as a disproportionate score.

1 ... Almost odorless 2 ... Slightly odorless 3 ... Odorous 4 ... Quite strong odor 5 ... Strong odor (a) Solubility of resin First, dissolve the DCPD resin or rosin-modified phenolic resin in each solvent of the head, and then the same. The resin concentration was gradually reduced by adding the above solvent, and the resin concentration at the time of turbidity was used as the standard for the solubility of the resin.
It can be said that the solvent having a lower resin concentration has better solubility in the resin.

(C) Storage stability of ink An ink was produced by the following formulation, which is a typical formulation example for offset rotary printing. Formulation wt% Rosin-modified phenolic resin 32.5 Flaxseed oil 13.0 Pigment (Carmine 6B) 17.5 Solvent 37.0 The storage stability was evaluated by putting the ink blended with the above formulation in a spread meter and spreading the ink after 1 minute at 25 ° C. Was measured. The ratio (%) of the value immediately after the production of the ink and the value after the storage for one month is shown. The liquidity does not change, that is, 100 does not decrease, 100 decreases.
Indicates a value that exceeds.

(D) Gloss of printed matter Ink manufactured according to the ink formulation of (c) above 0.4 m
1 was spread on an art paper by an RI tester, left for 24 hours, and then its gloss was measured by a 60 ° -60 ° gloss meter.

(C) Evaluation results As shown in Table-1, the solvents of Examples 1 and 2 do not contain benzene, toluene, xylene, naphthalene or biphenyl, which are subject to legal regulation, and have high viscosity at low temperature. Is not recognized. On the other hand, Comparative Example 2 is solidified at -7 ° C, and Comparative Example 3 shows a remarkable increase in viscosity at -10 ° C.

As shown in Table-2, the solvent of Comparative Example 1 showing good properties in Table-1 is inferior in solubility, storage stability and gloss of the printed matter. Although the solvent of Comparative Example 2 is good and good for each item,
As described above, solidification occurs at -7 ° C, which is a practical problem.
The solvent of Comparative Example 3 has bad odor in addition to the above-mentioned drawbacks. On the other hand, the solvents of Examples 1 and 2 show excellent performance in each item of Table-2.

Claims (2)

[Claims] 1. Naphthenes 30-80 wt%, isoparaffins
A solvent composition for a printing ink having a boiling point of 230 to 300 ° C., which comprises 15 to 40 wt%, 0 to 20 wt% of n-paraffins, 2 to 15 wt% of tetralins, and 0 to 10 wt% of aromatic hydrocarbons. 2. The solvent composition for a printing ink according to claim 1, wherein the aromatic hydrocarbon is substantially free of benzene, toluene, xylene, naphthalene and biphenyl.