WO2014178805A1

WO2014178805A1 - Printing ink in instant form and production method thereof

Info

Publication number: WO2014178805A1
Application number: PCT/TR2014/000113
Authority: WO
Inventors: Okan BUDİN
Original assignee: Budi̇n Akarca Mürekkep Ve Boya Sanayi̇ Ti̇caret Anoni̇m Şi̇rketi̇
Priority date: 2013-04-29
Filing date: 2014-04-22
Publication date: 2014-11-06
Also published as: EA201591847A1; EA032121B1; EP2992055A1; UA116468C2

Abstract

The present invention relates to an inks used in packaging industry. The present invention especially relates to printing ink (10) in instant form (powder form that soluble inside liquid by itself) which is used in flexo and rotogravure printing and consisting of pigment, binder, solvents and auxiliary chemicals and the production method of said ink (10).

Description

DESCRIPTION

Printing ink in instant form and production method thereof

Technical Field The present invention relates to an inks used in packaging industry.

The present invention especially relates to printing ink in instant form (powder ink that soluble inside liquid by itself) which is used in flexo and rotogravure printing and consisting of pigment, binder, solvents and auxiliary chemicals and the production method of said ink. Prior Art

Printing is a process of transffering images, writings, graphics and pictures on a surface rapidly with maximum similarity. Today, most common printing types used in printinghouse are letterpress, offset, serigraphy, flexo and rotogravure.

In printing applications, inks are used. Ink is a kind of liquid material which is produced with different kind of colorants, solvents, additives etc. and used for writing, drawing pattern and printing. Most of all writings and pictures on books, newspapers, magazines, packagings, boxes, moneys, posters, stamps, brochures are prepared with the inks.

In flexo and rotogravure printing applications, liquid inks are used. Liquid inks contain around 50-95% of solvent. Containing high percentage of solvent causes this inks classified as an inflammable and an explosive material. Therefore liquid inks present a danger during not only local deliveries but also worldwide sendings due to spillage and leaking. This kind of inks have high fire risk.

Storing and delivering processes of liquid ink are difficult; besides, it occupies larger space during transport and storage. Also, some disadvantages such as sedimentation, colour fading, deformation on packaging, limited shelf life etc. are seen in the liquid ink. Liquid inks have a long production processes. Most of the agents in formulation can only be used after they become semi-finished product. Thus, this circumstance leads to an increase in labor and energy costs.

In conclusion, an improvement in the relevant art is necessary due to the aforementioned drawbacks and the insufficiency of the existing solutions in the field.

Brief Description of the Invention

The present invention is developed by being inspired by the existing situations and seeks to solve the above mentioned drawbacks.

The primary purpose of the present invention is to provide obtaining a printing inks in instant form (powder ink that soluble inside liquid by itself) for use in packaging industry.

The present invention is intended to obtain a printing ink does not pose hazard during transportation and storage.

A purpose of the invention is to shorten production period by providing to obtain inks in a instant form (powder ink that soluble inside liquid by itself).

The present invention is also intended to obtain a printing ink with low cost.

Another purpose of the invention is to provide producing instant form (powder ink that soluble inside liquid by itself) of flexo and rotogravure printing inks.

In order to achieve the above mentioned purposes, the present invention is an ink in instant form (powder ink that soluble inside liquid by itself) which is used on packaging industry and comprising pigment, polyurethane and varnish.

In order to achieve the above mentioned purposes, the present invention is a method to obtain an ink in instant form (powder ink that soluble inside liquid by itself) and it comprises the following process step: - pre-mixing process of pigment, polyurethane and varnish,

- grinding of the obtained mixture,

- drying of the obtained liquid mixture by spraying from nozzle, - separating of powder particules via cyclone filters.

To achive the purposes of the present invention, said drying process is obtained by 80-120 °C stream of air. Premixing process is applied 20-100 minutes, under 30-70 °C heat and 4000-6000 speed. Said grinding process is done 60-80 minutes, under 30-70 °C heat, 1-5 engine current and 0,1 -0,5 bar pressure.

To achive the purposes of the present invention, instant ink (powder ink that soluble inside liquid by itself) comprises wetting agent and/or adhesion enhancer and/or defoaming agent and/or solvent. Said varnish contains individuals or combinations selected from among the nitrocellulose, ethylcellulose, acrylic, vinyl, polyurethane, fenolic resins. Also said solvent are consist of individuals or combinations selected from among the alcohols, esthers, aliphatics and aromatics.

To achive the purposes of the present invention, instant ink (powder ink that soluble inside liquid by itself) comprises by weight 5-50 % pigment, by weight 5-40 % polyurethane, by weight 5-80 % alcohol based solvent, by weight 5-40 % varnish, by weight 0,1-6 % wetting agent, by weight 0,001-1 % defoaming agent, by weight 5-80 % aliphatic esther based solvent, by weight 0,1-6 % adhesion enhancer, by weight 5-80 % glycol based solvent.

The structural and the characteristic features and all advantages of the present invention will be understood more clearly with the following figures and the detailed description written by referring to said figures. Therefore, the evaluation needs to be done by taking these figures and the detailed description into consideration.

Figures for a Better Understanding of the Invention

Figure 1 : Flow diagram view of instant ink (powder ink that soluble inside liquid by itself) production. Scaling of drawings is not absolutely required and details which are not needed for understanding the present invention could have been neglected. Furthermore, the elements which are at least substantially identical or have at least substantially identical functions are indicated with the same number. Description of Part references

10. Instant ink (powder ink that soluble inside liquid by itself) 15. Raw material 20. Adhesion enhancer 25. Intake air 30. Released air

A. Pre-mixing unit

B. Grinding machine

C. Mixing unit D. Drying Unit

X. Heater Y. Fan Z. Filter

E. Cyclone filters Detailed Description of the Invention

In this detailed description, instant ink (10) (powder ink that soluble inside liquid by itself) and production method which is subject of the present invention are described only for a better understanding of the subject, without constituting any restrictive effect. The present invention is the ink (10) in instant form (powder ink that soluble inside liquid by itself) for use in packaging industry and obtained from the raw materials consist of pigment, binders, solvents and chemical additives. Said ink is especially used in flexo and rotogravure printing.

While producing instant (powder ink that soluble inside liquid by itself) ink (10), it is possible to be used all types of organic and inorganic pigment used in ink industry. Pigment is a coloring agent that gives color to the product and is used in inks and flexible packaging printing sector. According to types of instant (powder ink that soluble inside liquid by itself) ink (10) that will be produced, at least one or the combination of a few pigments used with this purpose could be used. For instance; titannium dioxide is used for white ink.

Polyurethane resins and varnish is used as a binder. Polyurethane resin is used on flexible packaging printing sector and inks and gives flexibility and resistancy to the product. According to type of instant (powder ink that soluble inside liquid by itself) ink (10) that will be produced, it is possible to be used at least one or the combination of a few resins used with this purpose.

It is preferred a varnish that is produced with using nitro cellulose based resin for grinding pigment particules, binding grinded pigment particules, make homogenous film after being applied on printing material and used in flexible packaging printing sector and inks as a second type of binder. Depends on features of ink, said varnish includes cotton or beet based nitro cellulose resin which is dampened with % 30-35 alcohol. It is possible to be used one or the combination of a few type of resins providing formation of ink on printing material according to the type of instant (powder ink that soluble inside liquid by itself) ink (10) which is the subject of the invention. For example; in order to get required specialities of ink, varnishes prepared by using at least one or the combination of nitro cellulose, ethylcelulose, acrylic, vinyl, polyurethane, phenolic resins with each other is used for the production of instant (powder ink that soluble inside liquid by itself) ink (10) which is the subject of the invention.

Auxiliary chemicals are used to desired specialities and resistances on printing are provided by ink. According to desired specialities of ink, it is possible to be used alone or in different combinations of auxiliary chemicals such as defoaming agent for removing occured foam, wetting agent for dampening pigment and flexibility of occured film, adhesion enhancer for providing adhesion of ink film to printing material, micronized waxes for increase the frictional resistance, antislips, slips, surface active agent, viscosity adjuster, anti-sedimentation agent.

In the production of the instant (powder ink that soluble inside liquid by itself) ink (10) which is the subject of the invention, auxiliary chemicals such as wetting agent, defoaming agent, adhesion enhancer are used. Wetting agent provides dampening of pigment. Defoaming agent is used for removing the foam that might occur during mixture of ink, transportation, surging and while printing process on machine. Adhesion enhancer (20) helps to better adhesion of the ink to printing material used in printing and to form a homogenous film. In the production of the ink; it possible to be used all types of auxiliary chemicals used such as wetting agent, defoaming agent, adhesion enhancer in alone or in the combination form.

In the production of the instant (powder ink that soluble inside liquid by itself) ink (10) which is the subject of the invention; alcohol, alphatic esther and glycol based solvents are used. According to the feature of the ink, one or the combination of a few of ethanol, propanol, isobuthonal, isopropyl alcohol, buthanol etc, as alcohol based solvents; one or the combination of a few of ethyl acetate, buthylacetate, propylacetate etc. as an alphatic esther based solvent; one or the combination of a few of ethoxy propanol, methoxy propanol, buthyl glycol etc. as a glycol based solvent can be used. Besides, It is possible to be used one or different combinations of solvents such as alcohols, esthers, alphatics, aromatics etc. that are used in ink industry according to desired features of the ink.

Raw materials used in the production of instant (powder ink that soluble inside liquid by itself) ink (10) which is the subject of the invention and their usage percentage are given in below Table 1.

Table 1 : Content of instant (powder ink that soluble inside liquid by itself) ink (10) used on packaging sector and usage percentages

In figure 1 , flow chart of the production of the instant (powder that soluble inside liquid by itself) ink (10) is given. As it is seen on said chart; raw materials (15) composed of pigment, polyurethane, varnish, solvents (alcohol, glychol and alphatic esther based) and auxiliary chemicals (wetting agent, defoaming agent) are mixed in premixing unit (A) during 45 minutes with the percentages given in the Table 1. Said mixing process is performed under 50°C temperature and 5000 speed. It is possible to be performed premixing process at values between;

Duration : 20-100 minutes

Temperature: 30-70 °C

Speed: 4000-6000 Obtained mixture is put into grinding machine (B). Grinding process is performed in this unit during 15 minutes, under 40 °C temperature, with 50 speed, with 2,9 engine current and under 0,3 bar pressure.

It is possible to be performed grinding process at values between; Duration : 60-180 minutes Temperature : 30-70 °C Engine Current : 1-5 Pressure : 0,1-0,5 bar

Later, the gloss and grind amount needs to be checked. While checking whether if there is any grinded particules under 5 microns and while comparing the gloss with standart accepted sample, ±%10 differences is accepted. The grinding process should continue until the reference values are reached. The process stops when the reference values are reached.

A mixture that grinding process is completed is taken into another mixing unit (C) and adhesion enhancer (20) is added. The mixture applied grinding process and adhesion enhancer (20) added are mixed in the sa mixing unit (C). Obtained final mixture must be enough fluidity to be transferred from one place to another via pump. For that reason, recipe of the ink needs to be composed accordingly to obtain the desired fluidity. The mixture consisted in the desired fluidity is taken to drying unit (D). On the top part of the drying unit (D) there is one nozzle. Said mixture is sprayed by the nozzle that is adjusted according to the desired particle size. In order to completely remove solvents inside the mixture from the medium, the temperature in the drying unit (D) should be approximately 80-120°C (176-248°F) The entering temperature of the air being used in the drying unit (D) is important. High temperatures cause pigment to burn and decomposition in the product. For this reason, the temperature of the intake air (25) that enters to the drying unit (D) should be between the specified temperatures. Hot air flow can be parallel or opposite to the drops that fall during spraying. The drying process occurs in uniform form. In the drying unit (D), the drying time changes between 5-30 seconds due to surface area of the particles in the mixture is increased by spraying. The hot air flow inside the drying unit (D) is provided with one filter (Z), fan (Y) and heater (X). The ink in the powder form which slides under the drying unit (D) with air flow, is held in cyclone separator or bag filters (E). Dried product falls with its own weight and pile up, and the thin particles inside the air flow are separated using cyclone type separators (E). The instant (powder ink that soluble inside liquid by itself) ink (10) which is obtained by using spray drying technique, releases to the market in packages. The ink (10) which is the subject of the invention is a stable concentrated product that can adhesion to any surface because of its current content. The features like the particle size and density of the instant (powder ink that soluble inside liquid by itself) ink (10), which is obtained from the liquid form mixture by drying, is affected by the temperature of the drying gas and spraying process. Besides, the humidity rate of the final product (%2-5 humidity rate) is controlled by the heat and moisture of the released air flow (30) that comes out of the system. Before printing, instant (powder that soluble inside liquid by itself) ink ( 0) is prepared by adding different ratios of solvent or solvent mixtures according to desired pigmentation or solid content. For example, in order to prepare an ink with %10 solid content, 1 unit powder ink (10) is added to 9 units solvent or solvent mixture. It is dissolved by mixing in 150-200 speed for 5-10 minutes. There is no equipment needed to dissolve the instant (powder that soluble inside liquid by itself) ink(10). Instant (powder that soluble inside liquid by itself) ink (10) can dissolve inside the solvent on its own, with a basic mixing process. The ink prepared with this method, has the same characteristics and resistance properties with liquid ink prepared by the classic method. In order to dissolve the instant (powder that soluble inside liquid by itself) ink (10), alcohol based, aliphatic esther based and glycol based solvents used in the production of the ink (10) are being used. According to the feature of the ink, one or the combination of a few of ethanol, propanol, isobuthonal, isopropyl alcohol, buthanol etc, as alcohol based solvents; one or the combination of a few of ethyl acetate, buthylacetate, propylacetate etc. as an alphatic esther based solvent; one or the combination of a few of ethoxy propanol, methoxy propanol, buthyl glycol etc. as a glycol based solvent can be used. Besides, It is possible to be used one or different combinations of solvents such as alcohols, esthers, alphatics, aromatics etc. that are used in ink industry according to desired features of the ink. When instant (powder that soluble inside liquid by itself) ink (10) which is the subject of the invention mixes with solvent mixture and becomes liquid form, it can be applied to printing materials such as paper, card board, polypropylene, high density polyethylene (HDPE), low density polyethylene (LDPE), bi-oriented polypropylene (BOPP), pearlize, aluminium foil, metalize OPP, PET, PVC, coated paper alone or laminated in different combinations.

Instant (powder that soluble inside liquid by itself) ink (10) which is the subject of the invention does not contain any risk of fire, exploding or flashing. The solvent part of the ink in liquid form is evaporated and the solid part is packed. In the drying process, production of the instant (powder that soluble inside liquid by itself) ink (10) in desired particle size is obtained. This way, the re-grinding and milling of the powder is not needed. Besides, in the process of obtaining instant (powder that soluble inside liquid by itself) ink (10), when recovery of solvent system is added, it is possible to re-use the solvent that was evaporated. During the transportation of the liquid inks used in the current art, leakage and spillage can be seen. Instant (powder that soluble inside liquid by itself) ink (10) which is the subject of the invention eliminates these drawbacks. It provides savings in terms of transportation and storage area.

Since it is obtained a solvent-free instant (powder that soluble inside liquid by itself) ink (10), this circumstance protracts the shelf life of the product. Besides, transportation costs and carbon monoxide oscillation related to transportation decrease due to paper packaging's can be used for powder inks. Paper packages are lighter and has greater qualifications (really low carbon footprint) compared to metal packages. Metal packages are replaced rapidly with paper packages in the world.

The production of liquid inks in the current art is taking a long time. In the production method of instant (powder that soluble inside liquid by itself) ink (10) which is the subject of the invention, the product is obtained directly from the raw materials. This way, saving from the energy and labor cost is possible.

Claims

1. An ink (10) in instant form (powder form that soluble inside liquid by itself) used in the packaging sector, characterized in that; it comprises pigment, polyurethane and varnish.

2. An ink (10) according to claim 1 , characterized in that; it comprises wetting agent and/or adhesion enhancer and/or defoaming agent and/or solvent.

3. An ink (10) according to claim 1 , characterized in that; said varnish comprises individuals or combinations selected from among the nitrocellulose, ethylcellulose, acrylic, vinyl, polyurethane, fenolic resins.

4. An ink (10) according to claim 2, characterized in that; said solvent comprises individuals or combinations selected from among the alcohols, esters, aliphatics and aromatics.

5. An ink (10) according to claim 1 to 4, characterized in that; it comprises by weight %5-50 pigment, by weight %5-40 polyurethane, by weight %5-80 alcohol based solvent, by weight %5-40 varnish, by weight %0,1-6 wetting agent, by weight %0, 001-1 defoaming agent, by weight %5-80 aliphatic ester based solvent, by weight %0,1-6 adhesion enhancer and by weight %5-80 glycol based solvent.

6. A method to obtain an ink (10) in instant form (powder form that soluble inside liquid by itself) used in the packaging sector, characterized in that; it comprises the following process steps;

Premixing process of pigment, polyurethane and varnish,

Grinding of the obtained mixture,

Drying of the obtained liquid mixture by spraying from the nozzle,

Separating of powder particles via cyclone filters (E).

7. A method according to claim 6, characterized in that; it comprises the following process step; -adding wetting and/or defoaming agent and/or solvent and mixing before the grinding process.

8. A method according to claim 6 to 7, characterized in that; it comprises the following process step;

-adding adhesion enhancer (20) to the grinded mixture and mixing after the grinding process.

9. A method according to claim 6, characterized in that; said varnish comprises individuals or combinations selected from among the nitrocellulose, ethylcellulose, acrylic, vinyl, polyurethane, fenolic resins.

10. A method according to claim 7, characterized in that; said solvent comprises individuals or combinations selected from among the alcohols, esters, aliphatics and aromatics.

11. A method according to claim 6, characterized in that; said drying process is provided by the air flow between temperatures of 80-120°C.

12. A method according to claim 6, characterized in that; said premixing process is applied in 4000-6000 speed between temperatures 30-70°C for 20-100 minutes.

13. A method according to claim 6, characterized in that; said grinding process is applied in 1-5 motor current and 0,1-0,5 bar pressure between temperatures 30-70°C for 60-180 minutes.

14. A method according to claim 6 to 13, characterized in that; it comprises by weight %5-50 pigment, by weight %5-40 polyurethane, by weight %5-80 alcohol based solvent, by weight %5-40 varnish, by weight %0,1 -6 wetting agent, by weight %0, 001-1 defoaming agent, by weight %5-80 aliphatic ester based solvent, by weight %0,1-6 adhesion enhancer and by weight %5-80 glycol based solvent.