JPH0579112B2 - - Google Patents

Description

[Detailed description of the invention]

[Purpose of the Invention] (Industrial Application Field) The present invention is an ink that can be added to pasty printing inks, mainly lithographic or letterpress inks, to improve abrasion resistance, stacking properties, paper release properties from printing paper blankets, etc. The present invention relates to a printing ink additive containing wax- or resin-based particles that is effective in improving the properties of wax or resin, and further relates to a printing ink using this additive. (Prior art) Pastes that are lithographic or letterpress inks using hydrophobic organic liquids, such as sheet-fed offset inks, rotary offset inks, inks for metal plates, with or without dampening water; letterpress inks, etc. A lubricant such as polyethylene wax, polytetrafluoroethylene, or microcrystalline wax is generally added to the printing ink for the purpose of improving the abrasion resistance of the printed matter after drying. These particles are desired to be relatively uniform in particle size. As a means of adding particles mainly composed of wax or resin to pasty printing ink, there is a method of adding and dispersing particles after pulverizing them and adjusting the particle size distribution. After heating and dissolving with solvent,
There are methods such as dispersing with a stirrer or dispersing machine, forming a compound, and adding it. The wax or resin used is generally one that does not dissolve in the varnish or solvent of pasty printing ink. However, there are cases where a material that swells is used. However, pulverization has poor productivity and is disadvantageous in terms of cost since it requires adjustment of the average particle size. Furthermore, compounding the wax or resin requires time to manufacture as it is dispersed in a solvent, and it is difficult to set conditions. (Problem to be Solved by the Invention) Therefore, the wax or resin particles added to the paste printing ink have a uniform particle size, and the added paste printing ink has good abrasion resistance, stackability, and printing properties. There has been a desire for an additive for pasty printing inks that exhibits good paper release properties from paper blankets. Furthermore, there have been expectations for a printing ink additive that has excellent productivity and is easy to add. [Structure of the Invention] (Means for Solving the Problems) The present invention provides an aqueous dispersion of wax or resin, and one or two selected from resin, drying oil, or solvent, which are components of a pasty printing ink varnish. A hydrophobic organic liquid consisting of a mixture of the above,
This invention relates to a paste-like additive for printing ink, which is obtained by mixing and removing water. The additive for pasty printing ink of the present invention is produced by mixing an aqueous dispersion of wax or resin with a varnish or solvent for pasty printing ink consisting of a hydrophobic organic liquid, and forming particles mainly composed of wax or resin. The surface is coated with a hydrophobic printing ink material. The wax or resin-based particles constituting the aqueous dispersion have an average particle size of 30 μm or less;
Preferably particles are 0.1 to 20 μm. The wax or resin is selected from natural waxes, paraffin waxes, polyolefin waxes, or derivatives thereof, nylon resins, vinyl resins, silicone resins, epoxy resins, olefin resins, styrene resins, etc. species or two
It is a mixture of more than one species. These waxes or resins are generally those that do not dissolve in the varnish or solvent of the pasty printing ink. However, it may be one that partially swells. The method for producing the aqueous dispersion of wax or resin-based particles is not particularly limited, and the aqueous dispersion can be produced during synthesis or by post-processing. Commercially available aqueous dispersions can also be used. Note that additives can be used in the particles of the aqueous dispersion, if necessary. For the aqueous dispersion, a soap-free type that does not use a surfactant is preferable from the viewpoint of printability, but in order to improve the productivity of the aqueous dispersion and the ability to coat hydrophobic organic liquids, anionic, cationic, amphoteric or Nonionic surfactants can also be used. The hydrophobic organic liquid that coats the wax or resin-based particles of the aqueous dispersion is liquid at room temperature, and is a varnish or solvent for pasty printing inks. That is, it is one type or a mixture of two or more types selected from resins, drying oils, and solvents used in pasty printing ink varnishes described later. For example, it may be a mixture of a resin dissolved in a liquid component, a drying oil only, or a solvent only. As a mixture, resin 0-70
wt%, drying oil 0-100 wt% and solvent 0-70
It is preferable to mix it appropriately within the range of weight %. The amount of hydrophobic organic liquid used in the aqueous dispersion varies depending on the composition and viscosity of the organic liquid, solid content of the aqueous dispersion, particle composition and particle size, etc. 500% by weight is the easiest to convert from a water system to a wastewater system. The aqueous dispersion and the hydrophobic organic liquid are mixed by, for example, adding the aqueous dispersion little by little while stirring the hydrophobic organic liquid. The temperature during addition is between room temperature and 10°C lower than the melting point of the wax or resin, preferably from 30°C to 10°C lower than the melting point of the wax or resin. The hydrophobic organic liquid may be added while stirring the aqueous dispersion. The mixing may be carried out in such a way that the particles of the aqueous dispersion are coated with the varnish or solvent of the pasty printing ink, or undergo phase inversion and water is separated. Once the wax or resin has been coated or phase-inverted with a hydrophobic organic liquid, the water is removed by decantation or other methods, and if necessary, after washing with water, the hydrophobic organic liquid is added to maintain a constant solids content. .
Note that when the amount of the hydrophobic organic liquid is large, it is considered that the process is more like a phase transformation such as in flushing than coating. The additive for pasty printing ink of the present invention is
It is in liquid or wet solid form. The printing ink additive of the present invention is added to various pasty printing inks depending on the purpose, such as improving abrasion resistance, stacking properties, and the ability to release printed paper from a blanket. The amount added is preferably about 0.1 to 30% by weight of the solid content of the wax or resin in the printing ink. Since the additive for printing ink of the present invention is treated with a varnish for printing ink or a solvent, it can be easily added to printing ink. The paste printing ink according to the present invention includes 20 to 50% by weight of resins such as rosin-modified phenolic resins, petroleum resins, alkyd resins, or drying oil-modified resins, and 0% drying oils such as linseed oil, tung oil, and soybean oil. -30% by weight, 10-60% by weight of solvents such as normal paraffin, isoparaffin, naphthene, aromatique, α-olefin or mixtures thereof, 0 additives such as organic pigments, inorganic pigments, extender pigments, dryers, drying inhibitors, etc. Consisting of ~60% by weight. The printing ink of the present invention can be applied to lithographic plates, lithographic plates that do not require dampening water, and letterpress plates, and can be printed on coated paper, high-quality printing paper, medium-quality printing paper, cellophane, plastic, metal plates, fibers, and other printing substrates. It can be used against. The present invention will be explained below with reference to Examples.
"Part" and "%" indicate parts by weight and weight %. Varnish production example 1 To 50 parts of Tamanol 361 (rosin-modified phenolic resin manufactured by Arakawa Chemical Industries), 20 parts of linseed oil and 30 parts of No. 5 solvent (solvent for printing ink manufactured by Nippon Oil Co., Ltd.) were added and dissolved by heating at 200°C. Varnish A was produced. Further, 2 parts of aluminum octylate was added to 98 parts of this varnish A to produce gel varnish B. Varnish Production Example 2 Varnish C was produced in the same manner as in Varnish Production Example 1, except that Tamanol 354 (rosin-modified phenolic resin manufactured by Arakawa Chemical Industries) was used in place of Tamanol 361 in Varnish Production Example 1. Ink production example 65 parts of the gel varnish B obtained in varnish production example 1 and 18 parts of Lionol Blue SM (phthalocyanine blue manufactured by Toyo Ink Manufacturing Co., Ltd.) were milled using a three-roll mill, and after adding 1 part of cobalt naphthenate, No. 5 Using solvent, varnish A, and gel varnish B, the total amount is
93 parts, tack value 11.0~12.0, flow value 16.0~
17.0, and printing ink D was produced. Example 1 100 parts of Varnish A was stirred at 100 rpm using a high-speed mixer at room temperature, and 80 parts of Chemipearl M-200 (aqueous dispersion of low-density polyethylene manufactured by Mitsui Petrochemical Industries, solid content 40%, particle size 5 μm) was added dropwise. , the separated water was removed to obtain a printing ink additive. Add 5 parts of this additive to 100 parts of printing ink D, mix with a high speed mixer, and ink.
I got 1. Example 2 Varnish production example 2 instead of varnish A of example 1
Varnish C obtained from
Ink-2 was obtained in the same manner as in Example 1 using 87 parts of 0.5 μm). Example 3 An example using 80 parts of Chemipearl V-200 (aqueous dispersion of ethylene vinyl acetate copolymer resin manufactured by Mitsui Petrochemical Industries, solid content 40%, particle size 5 μm) instead of Chemipearl M-200 in Example 1. Ink-3 was obtained in the same manner as in Example 1. Example 4 Chemipearl W-100 (aqueous dispersion of polyethylene wax manufactured by Mitsui Petrochemical Industries, solid content 40%, particle size) was used instead of Chemipearl M-200 in Example 1.
Ink was applied in the same manner as in Example 1 using 80 parts of 3μm).
I got 4. Example 5 80 parts of Chemipearl M-200 was stirred at 100 rpm using a high-speed mixer at room temperature, and 32 parts of Solvent No. 5 was added dropwise, and gel varnish B obtained in Varnish Production Example 1 was added. An additive for printing ink was obtained. Add 5 parts of this additive to 100 parts of printing ink D, mix with a high speed mixer, and ink.
Got 5. Example 6 In place of Chemipearl M-200 in Example 1, Dulymer SE-120F (manufactured by Nippon Pure Chemical Industries, Ltd., aqueous dispersion mainly composed of polyacrylonitrile, solid content 124-26%,
Ink-6 was obtained in the same manner as in Example 1 using 128 parts (particle size: 0.1-0.4 μm). Comparative Example 1 To 100 parts of printing ink D, 2.5 parts of Sasol wax (FT wax manufactured by Sasol Corporation, particles with various shapes of which 90% have an average particle size of 10 μm or less) was added, mixed with a high-speed mixer, and ink was mixed.
I got a 7. Comparative example 2 Take 100 parts of varnish A in a hollow beaker and add AC
32 parts of polyethylene 6 (polyethylene manufactured by Allied Fibers & Plastics, in the form of spherical pellets) was mixed, heated to 90°C, melted, and passed through a three-roll mill with a surface temperature of 17°C for two passes to obtain a compound. This additive compound is added to printing ink.
5 parts were added to 100 parts of D and mixed using a high speed mixer to obtain Ink-8. [Evaluation of Ink] 1 Table 1 summarizes the actual time required to produce 1 kg of the additive used in the printing inks of Examples 1 to 6 and Comparative Examples 1 to 2. 2 The performance of the printing inks of Examples 1-6 and Comparative Examples 1-2 was tested for maximum particles in the ink and abrasion resistance, and the results are shown in Table 2. The evaluation method was ``time required for production'', which was expressed as the actual time from the end of measurement until it was possible to add it to the test ink. The unit is minutes. "Maximum particle in ink" Measured with a grindmeter and judged based on the average value of 5 measurements. "Abrasion resistance" Printed matter created with RI tester (printing material is
Pearl coat (coated paper manufactured by Mitsubishi Paper Mills). )
Using the Sutherland Love Tester, 2
lbs., tested under the conditions of 20 times. Good...○, Bad...×, Intermediate...△.

【table】

【table】

[Table] As seen from the evaluation results in Tables 1 and 2, the printing ink of the present invention simultaneously satisfied performance such as productivity, dispersibility, and film strength.

Claims (1)

[Scope of Claims] 1. An aqueous dispersion of wax or resin, and a hydrophobic organic liquid consisting of one or a mixture of two or more selected from resin, drying oil, or solvent, which is a pasty printing ink varnish component, A paste-like additive for printing ink that is obtained by mixing and removing water. 2. The paste-like printing ink additive according to claim 1, wherein the hydrophobic organic liquid is used in an amount of 50 to 500% by weight based on the amount of wax or resin in the aqueous dispersion.