Modified fat and method for producing the same, ink composition including the same and method for producing the same, and method for reducing development and / or solidification of precipitates in regenerated vegetable oil or ink composition including the same at low temperatures

Abstract

To provide a modified fat that can reduce the development and solidification of precipitates in regenerated vegetable oil at low temperatures and a method for producing the same, and an ink composition including the same.SOLUTION: A regenerated vegetable oil containing a specific compound derived from the reaction product or its modified form of a polyester compound formed by the condensation of a novolak resin having an epoxy group and a monohydroxy fatty acid having 12 or more carbon atoms is used as a modified oil. This modified fat, different from the original regenerated vegetable oil, reduces the development and solidification of precipitates at low temperatures, making it possible to use it without issue as an oil component in ink compositions.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a modified oil and fat and a method for producing the same, an ink composition using the same and a method for producing the same, and a method for suppressing the formation of precipitates and / or solidification at low temperatures in recycled vegetable oil or an ink composition containing the same. [Background technology]

[0002] There are various types of ink compositions used for printing depending on the printing method. These ink compositions include relatively high-viscosity paste-like ink compositions used in offset printing, letterpress printing, etc., and low-viscosity liquid ink compositions used in flexographic printing, gravure printing, inkjet printing, etc. Among these, oils and fats such as mineral oils and vegetable oils are used in high-viscosity paste-like ink compositions, and in recent years, ink compositions using vegetable oils as the main oil and fat have become widely available in consideration of the environment.

[0003] Vegetable oils used in preparing ink compositions include soybean oil and linseed oil, and in particular, vegetable oils such as soybean oil that can be used for food processing and cooking are widely used as components of ink compositions. Incidentally, such edible oils as soybean oil are used in large quantities every day as frying oil for cooking fried foods in food processing factories, restaurants, delicatessens, and the like. The frying oil used for cooking is replaced periodically because it deteriorates due to heating, and the used frying oil is discarded. The discarded edible oil is collected by waste oil collectors, and a portion of it is recycled and reused as fuel or as a raw material for various processed products.

[0004] As is well known, in recent years, recycling of waste materials has become increasingly common as one of the efforts toward sustainable social development. In the field of ink composition manufacturing, the use of recycled vegetable oil has long been considered as one such effort, and the use of recycled vegetable oil is now becoming common in the field of paste-type ink compositions that use a large amount of oils and fats. As an example of such an effort, Patent Document 1 proposes an offset ink composition that uses recycled vegetable oil. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2001-214105 A Summary of the Invention [Problem to be solved by the invention]

[0006] Although the term "recycled vegetable oil" is used broadly, the degree of deterioration of the oil varies depending on the conditions of use before it becomes waste. Generally, highly deteriorated vegetable oils have a high acid value and a low iodine value. This indicates that the vegetable oil has been decomposed or oxidized due to thermal or light degradation. If such highly deteriorated vegetable oil is used directly to prepare an ink composition, problems such as print staining and reduced storage stability may occur. In fact, the ink composition described in Patent Document 1 is preferably selected to use a recycled vegetable oil with an acid value of less than 3. Therefore, it is believed that the invention described in Patent Document 1 is intended to use a recycled vegetable oil that has undergone relatively little degradation.

[0007] Another problem that can occur with degraded recycled vegetable oil is a decrease in fluidity. As can be seen from the fact that the iodine value of degraded recycled vegetable oil is lower, the double bonds in the fat molecules that make up the vegetable oil are reduced, resulting in a higher melting point than virgin vegetable oil. As a result, degraded recycled vegetable oil has a high viscosity and reduced fluidity, and there is a risk of precipitation or solidification, especially at low temperatures.

[0008] The present invention has been made in view of the above circumstances, and aims to provide a modified oil and fat that can suppress the formation of precipitates and solidification in recycled vegetable oil at low temperatures, a method for producing the same, and an ink composition using the same. [Means for solving the problem]

[0009] The inventors conducted extensive research to solve the above-mentioned problems and discovered that adding a reaction product or a modified product thereof between a novolac resin having epoxy groups and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms to recycled vegetable oil and then heat-treating the mixture improved the fluidity of the recycled vegetable oil and inhibited the formation of precipitates or solidification at low temperatures, leading to the completion of the present invention. For ease of understanding, this specification also refers to "a reaction product or a modified product thereof between a novolac resin having epoxy groups and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms" as "a specific compound." Specifically, the present invention provides the following:

[0010] (1) The present invention relates to a modified oil or fat comprising recycled vegetable oil and a specific compound, wherein the specific compound is a reaction product or a modified product thereof of a novolak resin having an epoxy group and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms.

[0011] (2) The present invention also provides the modified oil or fat according to (1), wherein the acid value of the recycled vegetable oil is 1 mgKOH / g or more.

[0012] (3) The present invention also provides the modified oil or fat according to (1) or (2), wherein the regenerated vegetable oil has an iodine value of less than 110.

[0013] (4) The present invention also provides the modified oil or fat according to any one of (1) to (3), wherein the recycled vegetable oil is a recycled product of used soybean oil.

[0014] (5) The present invention also provides the modified oil or fat according to any one of (1) to (4), wherein the content of the specific compound is 0.1 to 7 parts by mass per 100 parts by mass of the recycled vegetable oil.

[0015] (6) The present invention also provides a method for producing modified oils and fats, comprising a step of heat-treating a mixture of recycled vegetable oil and a specific compound, wherein the specific compound is a reaction product or a modified product thereof of a novolak resin having an epoxy group and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms.

[0016] (7) The present invention also provides a method for producing a modified oil or fat according to (6), wherein the amount of the specific compound added is 0.1 to 7 parts by mass per 100 parts by mass of the recycled vegetable oil.

[0017] (8) The present invention also provides a method for producing a modified oil or fat according to (6) or (7), wherein the acid value of the recycled vegetable oil is 1 mgKOH / g or more.

[0018] (9) The present invention also provides the method for producing modified oils and fats according to any one of (6) to (8), wherein the recycled vegetable oil has an iodine value of less than 110.

[0019] (10) The present invention also provides a method for producing modified oils and fats according to any one of (6) to (9), wherein the recycled vegetable oil is recycled used soybean oil.

[0020] (11) The present invention also relates to an ink composition comprising the modified oil or fat according to any one of items (1) to (5).

[0021] (12) The present invention also provides an ink composition according to the above item (11), which is for offset printing.

[0022] (13) The present invention is also a method for producing an ink composition, which includes a step of heat-treating a mixture containing recycled vegetable oil and a specific compound, wherein the specific compound is a reaction product or a modified product thereof of a novolak resin having an epoxy group and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms.

[0023] (14) The present invention also provides a method for suppressing the formation of precipitates and / or solidification of recycled vegetable oil at low temperatures by adding to the recycled vegetable oil a reaction product or a modified product thereof of a novolak resin having an epoxy group and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms.

[0024] (15) The present invention also relates to a method for suppressing the formation of precipitates and / or solidification at low temperatures in an ink composition containing recycled vegetable oil, characterized in that when preparing an ink composition using recycled vegetable oil, the reaction product or modified product thereof of a novolak resin having an epoxy group and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms is called a specific compound, and the recycled vegetable oil used contains the specific compound. [Effects of the Invention]

[0025] According to the present invention, there are provided a modified oil and fat that can suppress the formation of precipitates and solidification in recycled vegetable oil at low temperatures, a method for producing the same, and an ink composition using the same. DETAILED DESCRIPTION OF THE INVENTION

[0026] An embodiment of the modified oil of the present invention, an embodiment of a method for producing the modified oil, an embodiment of an ink composition, and an embodiment of a method for producing the ink composition will be described below. Note that the present invention is not limited to the following embodiment or embodiment, and can be practiced with appropriate modifications within the scope of the present invention.

[0027] <Modified oils and fats> First, one embodiment of the modified oil of the present invention will be described. The modified oil of the present invention comprises recycled vegetable oil and a specific compound. As described above, this specific compound is a reaction product or a modified product thereof of a novolak resin having an epoxy group and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms. The following is a description.

[0028] [Regenerated vegetable oil] The recycled vegetable oil used in the present invention is vegetable oil that has been degraded by heating or exposure to light and then regenerated. The regeneration process referred to here includes, for example, filtering out residues such as fried food residue after use in the case of edible oil used to prepare fried foods. The degraded vegetable oil may also be recovered and used as is. In such cases, strictly speaking, no processing other than recovery has been performed, but even in this case, the oil is considered "regenerated vegetable oil" in the present invention.

[0029] In the present invention, the cause of deterioration of the vegetable oil used as a raw material for recycled vegetable oil is not particularly important. Examples of such deterioration causes include, but are not limited to, being heated as a frying oil in deep-frying, being used as a lubricant in food processing machines, or being left exposed to sunlight. A typical example is being used as a frying oil in deep-frying. Waste oil used as frying oil is collected by specialized collection companies, and the residue contained therein is filtered out to produce recycled vegetable oil. Such recycled vegetable oil is commercially available in various grades depending on the degree of deterioration, so it is possible to obtain and use such commercially available products.

[0030] The vegetable oil may be edible or non-edible. Examples of such vegetable oils include salad oil, corn oil, olive oil, soybean oil, sunflower oil, canola oil, rapeseed oil, safflower oil, linseed oil, tung oil, castor oil, coconut oil, and palm oil. Among these, soybean oil is a preferred example. In this case, the recycled vegetable oil is a recycled product of used soybean oil.

[0031] Degraded vegetable oils have a lower iodine value and an increased acid value compared to the vegetable oil before degradation. This is because the unsaturated bonds contained in the oil molecules decrease and carboxyl groups are generated in the molecules as the oil deteriorates. The iodine value and acid value serve as indicators of the deterioration of the vegetable oil. An example of the iodine value of the recycled vegetable oil used in the present invention is less than about 110. As is well known to those skilled in the art, the iodine value is the number of grams of iodine added to 100 g of oil. An example of the acid value is 1 mg KOH / g or more and 50 mg KOH / g or less. The lower limit of this acid value is 5 mg KOH / g or 10 mg KOH / g.

[0032] Furthermore, deteriorated vegetable oils may generate hydroperoxide groups (-OOH) at the sites where double bonds previously existed in the oil molecules. In this case, the recycled vegetable oil will have a peroxide value (POV). The recycled vegetable oil of the present invention preferably has a peroxide value of 1 meq / kg or more. The upper limit of this peroxide value is preferably about 1000 meq / kg, more preferably about 800 meq / kg, and even more preferably about 700 meq / kg. The lower limit of the peroxide value is preferably 1 meq / kg, as described above, more preferably about 10 meq / kg, and even more preferably about 30 meq / kg. As is well known, the peroxide value can be determined by reacting potassium iodide with the oil to be measured and titrating the liberated iodine (I2) with a 0.01 N sodium thiosulfate solution. That is, the hydroperoxide groups in fats and oils are replaced with iodine molecules (I2), and the iodine molecules react with starch to turn it blue-purple. This is used to titrate with sodium thiosulfate to determine the amount of sodium thiosulfate consumed until the color disappears. Based on the titration results, the milligram equivalents (meq) of peroxide contained in 1 kg of fat or oil is calculated, which becomes the peroxide value (unit: meq / kg).

[0033] Degraded recycled vegetable oil, i.e., with a low iodine value and a high acid value, not only has high viscosity and poor fluidity at room temperature, but also forms precipitates and solidifies at low temperatures. As already mentioned, such recycled vegetable oil is unsuitable as a raw material for ink compositions, etc. In the present invention, a specific compound (a reaction product or modified product of a novolac resin having an epoxy group and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms) described below is added to such degraded recycled vegetable oil and heat-treated, thereby particularly suppressing the formation of precipitates and solidification of the recycled vegetable oil at low temperatures.

[0034] [Specific compound] The specific compound used in the present invention is a reaction product or modified product thereof between a novolac resin having an epoxy group and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms. While investigating methods for suppressing solidification of deteriorated recycled vegetable oils to ensure their fluidity, the inventors unexpectedly discovered that a compound having both a polyester compound skeleton condensed with a monohydroxy fatty acid and a novolac skeleton effectively suppresses solidification of recycled vegetable oils. The modified oils and fats of the present invention are based on this finding and include, as the specific compound, a reaction product or modified product thereof between a novolac resin having an epoxy group and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms. This specific compound contains both the polyester skeleton and the novolac skeleton.

[0035] A novolak resin having an epoxy group (hereinafter also referred to as "compound (X)") is synthesized, for example, by reacting a novolak resin having a phenolic hydroxyl group with an epichlorohydrin derivative such as epichlorohydrin or β-methylepichlorohydrin in a conventional manner. Various types of novolak resins having such an epoxy group are commercially available for use in preparing epoxy resins, and such commercially available products may be obtained and used to prepare a specific compound.

[0036] As the novolak resin having a phenolic hydroxyl group, for example, a novolak resin derived from a monohydric or polyhydric phenol and an aldehyde by a conventional method can be used.

[0037] Among these, examples of monohydric phenols include unsubstituted phenols such as phenol, cresol, xylenol, trimethylphenol, propylphenol, butylphenol, amylphenol, hexylphenol, octylphenol, nonylphenol, and dodecylphenol, and substituted phenols such as alkylphenols. Examples of polyhydric phenols include catechol, resorcinol, hydroquinone, trihydroxybenzene, and substituted derivatives thereof, as well as dihydroxydiphenylmethanes and dihydroxybiphenyls such as bisphenol A and bisphenol F. These phenols may be used alone or in combination of two or more.

[0038] The aldehydes may be any aldehydes commonly used for producing novolac resins, without any particular limitation. Specific examples include lower aliphatic aldehydes such as formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, n-butylaldehyde, isobutylaldehyde, and glyoxal, and aromatic aldehydes such as furfural and phenylaldehyde. These aldehydes may be used alone or in combination of two or more.

[0039] Novolac resins can be synthesized by reacting the above-mentioned phenols and aldehydes in the presence of an acid catalyst such as paratoluenesulfonic acid, perchloric acid, hydrochloric acid, nitric acid, sulfuric acid, chloroacetic acid, oxalic acid, phosphoric acid, etc. at 80 to 130° C. The progress of this reaction can be monitored by gel permeation chromatography (GPC) or the like.

[0040] Examples of polyester compounds (hereinafter also referred to as compound (Y)) obtained by condensing monohydroxy fatty acids having 12 or more carbon atoms include those obtained by condensing monohydroxy fatty acids having 12 or more carbon atoms, such as 12-hydroxystearic acid, with each other in the presence of an esterification catalyst. These monohydroxy fatty acids have both a hydroxyl group and a carboxyl group in the molecule, and therefore undergo dehydration condensation (esterification reaction) with each other to produce polyester compounds. Such polyester compounds contain a carboxyl group in the molecule that can react with an epoxy group, and react with the epoxy group contained in the molecule of compound (X) to produce a reaction product.

[0041] To obtain a reaction product by reacting the compound (X) and the compound (Y), the mixture is heated. If necessary, a suitable solvent such as dimethylformamide (DMF), toluene, or xylene may be added. The reaction temperature during the reaction can be, but is not limited to, approximately 100 to 175°C. As the compound (X) and the compound (Y) react, the carboxyl group contained in the compound (Y) is consumed, and the acid value of the reaction mixture decreases. Therefore, the progress and completion of the reaction can be determined by monitoring the acid value during the reaction. The acid value at the end of the reaction can be, but is not limited to, approximately 0.1 to 1.0 mgKOH / g.

[0042] The mixing ratio of compound (X) and compound (Y) may be appropriately determined taking into consideration the number of epoxy groups contained in one molecule of compound (X) and the number of carboxy groups contained in one molecule of compound (Y). A preferred example of the mixing ratio of compound (X) and compound (Y) is a ratio in which 0.5 to 0.9 moles of carboxy groups contained in compound (Y) are contained per mole of epoxy groups contained in compound (X), and a more preferred example is a ratio in which 0.6 to 0.85 moles of carboxy groups contained in compound (Y) are contained per mole of epoxy groups contained in compound (X), but this is not particularly limited.

[0043] The reaction product thus obtained may be used as the specific compound as is, or, if necessary, a compound having two or more carboxy groups in the molecule may be further added as compound (Z) to form a modified product, which may then be used as the specific compound. In this case, if a novolak resin having two or more epoxy groups is used as compound (X), the compounds (X) modified with compound (Y) are crosslinked by compound (Z), resulting in a modified product with a higher molecular weight. Using such a modified product with a higher molecular weight as the specific compound is preferred because it can suppress problems such as misting, which are often observed when a low-molecular-weight resin compound is added to an ink composition.

[0044] The compound (Z) is not particularly limited as long as it has two or more carboxy groups in the molecule, and examples of such compounds include isophthalic acid, terephthalic acid, adipic acid, pimelic acid, suberic acid, sebacic acid, and succinic anhydride.

[0045] The reaction temperature when crosslinking with compound (Z) is, for example, about 125 to 175°C, but is not particularly limited thereto. As unreacted epoxy groups react with compound (Z), the number of carboxy groups contained in compound (Z) decreases, and the acid value of the reaction mixture decreases. Therefore, by monitoring the acid value during the reaction, it is possible to determine the progress and completion of the reaction. For example, if the acid value no longer decreases even after the reaction is continued, this means that the epoxy groups have been consumed, and it can be determined that the reaction has ended.

[0046] The amount of compound (Z) added may be determined appropriately depending on the amount of epoxy groups contained in compound (X) and the amount of carboxy groups contained in compound (Y) used in the reaction. A preferred example of such an amount is a ratio of 0.5 to 0.9 moles of carboxy groups contained in compound (Z) per mole difference between the number of moles of epoxy groups contained in compound (X) and the number of moles of carboxy groups contained in compound (Y), and a more preferred example is a ratio of 0.6 to 0.85 moles of carboxy groups contained in compound (Z), but this is not particularly limited.

[0047] The amount of the specific compound added in the modified oil or fat is preferably about 0.1 to 7 parts by mass, more preferably about 0.5 to 6.5 parts by mass, even more preferably about 1 to 6 parts by mass, and particularly preferably about 2 to 5 parts by mass, per 100 parts by mass of the recycled vegetable oil to be modified.

[0048] To prepare the modified oil of the present invention, the recycled vegetable oil to be treated and the specific compound are mixed and heated with stirring. The heating temperature is not particularly limited, but may be, for example, about 50 to 150°C. By performing this heating and stirring, the mixed specific compound is completely dissolved in the recycled vegetable oil, thereby preparing the modified oil.

[0049] <Method for manufacturing modified oils and fats> The method for producing the modified oil of the present invention is also one aspect of the present invention. The method for producing the modified oil of the present invention includes a step of heat-treating a mixture of recycled vegetable oil and the specific compound. This step has already been described, so further explanation will be omitted here.

[0050] The acid value of the recycled vegetable oil to be treated is 1 mgKOH / g or more and 50 mgKOH / g or less, and the iodine value is less than 110. As already mentioned, the recycled vegetable oil is preferably a recycled product of used soybean oil. As already mentioned, the recycled vegetable oil is preferably a recycled product of used soybean oil.

[0051] <Ink composition> An ink composition containing the modified oil of the present invention as an oil component also constitutes one aspect of the present invention.

[0052] The ink composition of the present invention contains the modified oil and fat as an oil component, and is therefore a paste-type ink composition. Among such ink compositions, the ink composition of the present invention is preferably an offset ink composition, and particularly preferably an ink composition for newspaper printing. The ink composition of the present invention has the same composition as a conventional ink composition, except that the modified oil and fat is used as at least a part of the oil component. Such ink compositions generally contain a color pigment, a binder resin, and an oil component. Each component will be described below.

[0053] [Coloring pigments] Color pigments are components that impart coloring power to ink compositions. Examples of color pigments include organic and / or inorganic pigments that have traditionally been used in ink compositions. Examples of such color pigments include yellow pigments such as Disazo Yellow (Pigment Yellow 12, Pigment Yellow 13, Pigment Yellow 17, and Pigment Yellow 1) and Hansa Yellow; magenta pigments such as Brilliant Carmine 6B, Lake Red C, and Watching Red; cyan pigments such as Phthalocyanine Blue, Phthalocyanine Green, and Alkali Blue; black pigments such as carbon black; and fluorescent pigments. Metal powder pigments that impart metallic colors such as gold and silver to ink compositions are also considered color pigments in the present invention. Examples of such metal powder pigments include gold powder, bronze powder, aluminum paste prepared by processing aluminum powder into a paste, and mica powder.

[0054] The amount of color pigment added is, for example, about 8 to 30 mass % of the total ink composition, but is not particularly limited. When preparing a yellow ink composition using a yellow pigment, a magenta ink composition using a magenta pigment, a cyan ink composition using a cyan pigment, or a black ink composition using a black pigment, it is also possible to use a pigment of another color in combination or add an ink composition of another color as a complementary color.

[0055] [Binder resin] The binder resin functions as a binder to fix the pigment on the surface of printing paper and is also used to disperse the pigment in the ink composition. Examples of such binder resins include, without limitation, those commonly used in the field of ink compositions, such as rosin-modified phenolic resins, rosin-modified maleic acid resins, rosin-modified alkyd resins, rosin-modified petroleum resins, rosin ester resins, petroleum resin-modified phenolic resins, acrylic-modified phenolic resins, alkyd resins, vegetable oil-modified alkyd resins, and petroleum resins. The weight-average molecular weight of these resins is preferably about 1,000 to 300,000. These resins may be used alone or in combination.

[0056] Among these binder resins, from the viewpoints of good pigment dispersibility, print quality, and stable printability over long periods of time, it is preferable to use at least one resin selected from the group consisting of rosin-modified phenolic resins, rosin-modified maleic acid resins, and alkyd resins. The weight-average molecular weights of the rosin-modified phenolic resins and rosin-modified maleic acid resins are not particularly limited, but examples thereof include approximately 10,000 to 300,000. The weight-average molecular weight of the alkyd resins is not particularly limited, but examples thereof include approximately 1,000 to 30,000. The amount of binder resin added is preferably approximately 10 to 45% by mass of the total ink composition.

[0057] The binder resin is dissolved or dispersed by heating together with an oil component described below, and used in the form of a varnish. When preparing the varnish, a gelling agent such as a metal chelate compound or a metal soap may be added to the dissolved varnish obtained by dissolving the resin to form a gelled varnish. It is preferable to prepare a gelled varnish from the binder resin and use this in preparing the ink composition, as this can impart appropriate viscoelasticity to the ink composition.

[0058] [Oil component] The oil component is used to dissolve or disperse the resin to prepare a varnish or to adjust the viscosity of the ink composition. The ink composition of the present invention is characterized by containing the modified oil / fat of the present invention as at least a portion of the oil component. The modified oil / fat may be used as an oil component for dissolving the binder resin to prepare a varnish, or as an oil component for preparing an ink composition from the varnish, or both. The modified oil / fat may be prepared by previously heating recycled vegetable oil and a specific compound, or by heating a mixture containing recycled vegetable oil, a specific compound, and other components. For example, heating a mixture containing recycled vegetable oil, a specific compound, and a binder resin results in a varnish containing the modified oil / fat and the binder resin. When an ink composition is prepared using such a varnish, the ink composition naturally contains the modified oil / fat of the present invention. Furthermore, the ink composition of the present invention may contain other oil components in addition to the modified oil / fat of the present invention, as needed. Such other oil components may include vegetable oils and mineral oils.

[0059] Examples of such vegetable oils include drying oils and semi-drying oils such as soybean oil, cottonseed oil, linseed oil, safflower oil, tung oil, tall oil, dehydrated castor oil, canola oil, castor oil, coconut oil, and palm oil. These vegetable oils can be used alone or in combination of two or more. The content of the vegetable oil and the modified oil in the ink composition can be, for example, about 5 to 60% by mass of the entire ink composition.

[0060] Examples of mineral oils include light mineral oils called solvent components and heavy mineral oils that are lubricating oils.

[0061] Examples of light mineral oils include non-aromatic petroleum solvents with a boiling point of 160° C. or higher, preferably 200° C. or higher. Examples of such non-aromatic petroleum solvents include AF Solvent No. 4, AF Solvent No. 5, AF Solvent No. 6, and AF Solvent No. 7 manufactured by ENEOS Corporation.

[0062] Heavy mineral oils include various lubricating oils classified as spindle oil, machine oil, dynamo oil, cylinder oil, etc. Among these, from the viewpoint of conforming to U.S. OSHA standards and EU standards, those with a reduced content of condensed polycyclic aromatic components are preferred. Examples of such mineral oils include Ink Oil H8 and Ink Oil H35 manufactured by ENEOS Corporation, and SNH8, SNH46, SNH220, and SNH540 manufactured by Sankyo Yuka Kogyo Co., Ltd.

[0063] These mineral oils can be used alone or in combination of two or more. The content of the mineral oil in the ink composition can be, for example, about 0 to 50 mass % based on the total mass of the ink composition.

[0064] [Other ingredients] In addition to the above components, various other components may be added to the ink composition of the present invention as needed to improve printing performance, etc. Examples of such various components include colorless pigments, resins such as alkyd resins and petroleum resins, salts such as Gilsonite and phosphates, waxes such as polyethylene wax, olefin wax, and Fischer-Tropsch wax, alcohols, antioxidants, etc.

[0065] Colorless pigments, also called extender pigments, are preferably used to adjust properties such as viscoelasticity in the ink composition. Examples of colorless pigments include clay, talc, kaolinite (kaolin), barium sulfate, calcium carbonate, silicon oxide, bentonite, and titanium oxide. The amount of colorless pigment added is, for example, about 0 to 33% by mass of the total ink composition, but is not particularly limited.

[0066] A known method can be used to prepare the printing ink composition of the present invention using the above components. For example, the above components are mixed and milled in a bead mill or triple-roll mill to disperse the pigment, and then additives (antioxidants, alcohols, waxes, etc.) are added as needed, followed by adding an oil component to adjust the viscosity. The viscosity of the ink composition is, for example, 2.0 to 20 Pa·s at 25°C as measured by a Raley viscometer, but is not particularly limited thereto.

[0067] <Method for producing ink composition> The method for producing the ink composition also constitutes one aspect of the present invention. The method for producing the ink composition of the present invention is characterized by comprising a step of heat-treating a mixture containing recycled vegetable oil and the specific compound. These details have already been explained, so further explanation will be omitted here.

[0068] <Method for suppressing the formation of precipitates and / or solidification of recycled vegetable oil at low temperatures> The present invention also provides a method for suppressing the formation and / or solidification of precipitates in recycled vegetable oil by adding to the recycled vegetable oil a reaction product or a modified product thereof of a novolak resin having the above-mentioned epoxy group and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms.

[0069] <Method for suppressing formation of precipitates and / or solidification of ink compositions containing recycled vegetable oil at low temperatures> When preparing an ink composition using recycled vegetable oil, if the reaction product or modified product of a novolak resin having an epoxy group and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms is called a specific compound, one aspect of the present invention is a method for suppressing the formation of precipitates and / or solidification of an ink composition containing recycled vegetable oil at low temperatures, characterized by using the recycled vegetable oil containing this specific compound. [Example]

[0070] The present invention will be explained in more detail below by showing examples, but the present invention is not limited to the following examples in any way.

[0071] [Novolak resin having epoxy groups (compound (X))] The following commercially available products were obtained as novolac resins having epoxy groups and used as novolac resins A to C. Novolac resin A: YDPN-638 manufactured by Nippon Steel Chemical & Material Co., Ltd. Novolac resin B: YDCN-700-10 manufactured by Nippon Steel Chemical & Material Co., Ltd. Novolac resin C: EPPN-201 manufactured by Nippon Kayaku Co., Ltd.

[0072] [Synthesis of Polyester A (Compound (Y))] A separable flask equipped with a condenser, a water separation tube, a thermometer, and a nitrogen inlet tube was charged with 300 parts by mass of 12-hydroxystearic acid, 30 parts by mass of xylene, and 0.3 parts by mass of tetra-n-butyl titanate, and the mixture was heated and stirred at 180 to 200°C for 3 hours under a nitrogen stream while separating the generated water with the water separation tube. Next, the xylene was distilled off under reduced pressure to obtain Polyester A, a light brown polymer with a weight-average molecular weight of 800 and an acid value of 80.

[0073] [Synthesis of specific compounds 1 to 9] A reaction vessel was charged with 30 parts by mass of the novolak resin shown in the Compound (X) column in Table 1 below, 64 parts by mass of the polyester A obtained by the above procedure, and 50 parts by mass of dimethylformamide (DMF), and the mixture was heated and stirred at 130 to 150°C for 2 hours under a nitrogen stream. Next, 6 parts by mass of compound (Z1) shown in Table 1 was added, and the mixture was heated and stirred at the same temperature for 2 hours, after which 6 parts by mass of compound (Z2) shown in Table 1 was added, and the mixture was heated and stirred at the same temperature for an additional 3 hours. Thereafter, DMF was distilled off under reduced pressure to obtain specific compounds 1 to 9, respectively.

[0074] [Table 1]

[0075] [Preparation of modified oils and fats (Examples 1 to 18)] Any of the specific compounds 1 to 9 was added to recycled vegetable oil (acid value: 4.0 mg KOH / g, iodine value: 105) in the proportions shown in Tables 2 and 3, and the modified oils and fats of Examples 1 to 18 were obtained by heat treatment at 80°C for 30 minutes.

[0076] [Preparation of modified oils and fats (Comparative Examples 2 to 9)] Polyester A or any of novolac resins A to C was added to recycled vegetable oil (acid value: 4.0 mgKOH / g, iodine value: 105) in the proportions shown in Table 4, and the mixture was heated at 80°C for 30 minutes to obtain the modified oils and fats of Comparative Examples 2 to 9. Note that Comparative Example 1 is the recycled vegetable oil itself used as the raw material.

[0077] [Evaluation of the stability of modified oils and fats] The resulting modified oils and fats (Examples 1 to 18, Comparative Examples 2 to 9) and recycled vegetable oil (Comparative Example 1) were each left to stand for 24 hours at 5° C., after which their flow state and appearance were observed. The evaluation criteria were as follows, and the evaluation results are shown in the “Stability of modified oils and fats” column in Tables 2 to 4. ○: Good fluidity, no precipitates observed △: Fluidity is slightly reduced, but there are no precipitates and no problems with use. ×: No fluidity, the whole solidified or precipitates were observed, and it is not possible to use it.

[0078] [Preparation of varnish] To prepare an ink composition containing the modified oil and fat obtained by the above procedure, a varnish for preparing the ink composition was first prepared. A four-neck flask equipped with a condenser, thermometer, and stirrer was charged with 35 parts by weight of a rosin-modified phenolic resin (KG-2212, manufactured by Arakawa Chemical Industries, Ltd.) with a weight-average molecular weight of 100,000, 20 parts by weight of soybean oil, and 44.5 parts by weight of mineral oil (AF Solvent No. 7, manufactured by ENEOS Corporation). The temperature was then raised to 200°C and maintained at that temperature for 1 hour to dissolve the resin. Then, 0.5 parts by weight of aluminum ethyl acetoacetate diisopropylate (ALCH, manufactured by Kawaken Fine Chemicals Co., Ltd.) was added, and the mixture was heated to 170°C for 60 minutes to obtain a varnish. The soybean oil used to prepare the varnish was virgin. Here, "virgin soybean oil" refers to commercially available soybean oil, not recycled soybean oil.

[0079] [Preparation of ink composition] Ink compositions were prepared using each of the modified oils and fats of Examples 1-18 and Comparative Examples 2-9, as well as the recycled vegetable oil of Comparative Example 1. 16 parts by mass of cyanine blue pigment, 10 parts by mass of calcium carbonate (Shiraishi Calcium Co., Ltd., Hakuenka CC), 64 parts by mass of the above varnish, and 10 parts by mass of either the modified oils and fats of Examples 1-18 and Comparative Examples 2-9 or the recycled vegetable oil of Comparative Example 1 were mixed together. The resulting mixture was milled in a three-roll mill until a sufficiently vivid hue and gloss was achieved for the ink composition, yielding a cyan base. The viscosity of the resulting cyan base was adjusted by adding virgin soybean oil as needed, yielding an ink composition with a Raleigh viscosity of 6.0 Pa·s (25°C). Reference ink compositions were also prepared using virgin soybean oil instead of the modified oils and recycled vegetable oil.

[0080] [Measurement of residue amount in ink composition] The amount of residue contained in each ink composition was measured for each of the modified oils and fats in Examples 1 to 18 and Comparative Examples 2 to 9, and for ink compositions using recycled vegetable oil or virgin soybean oil in Comparative Example 1. First, virgin soybean oil was added dropwise to 100 g of the ink composition to be measured while stirring with a glass rod to reduce the viscosity to a level that would allow the ink composition to pass through a wire mesh. The resulting low-viscosity ink composition was filtered through a wire mesh with a mesh size of 400, and the material remaining on the wire mesh was recovered. The oil remaining on the surface of the material was wiped off with paper (product name: Kimwipe, manufactured by Nippon Paper Crecia Co., Ltd.), and the residue was then placed on the paper and allowed to dry thoroughly. The mass of the resulting residue was measured and evaluated according to the following criteria. The results are shown in the "Amount of Residue in Ink" column of Tables 2 to 4. ○: The amount of residue is equal to or less than the amount of residue of the ink composition prepared using virgin soybean oil (i.e., the standard product). ×: The amount of residue is larger than that of the ink composition prepared using virgin soybean oil (i.e., the standard product).

[0081] [Table 2]

[0082] [Table 3]

[0083] [Table 4]

[0084] As can be seen from Tables 2 to 4, the modified oils and fats obtained by adding the specific compounds of the present invention to recycled vegetable oils and then heat-treating them all exhibited practically acceptable stability, and the amount of residue left when ink compositions were prepared using these modified oils and fats was also low, which was a good result.On the other hand, recycled vegetable oils to which nothing was added, and modified oils and fats to which polyester or novolac resins, which are raw materials for the specific compounds, were added, showed poor stability and left large amounts of residue when ink compositions were prepared.

Claims

1. Comprising recycled vegetable oil and a specific compound, The modified oil and fat is characterized in that the specific compound is a reaction product of a novolak resin having an epoxy group and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms, or a modified product thereof.

2. The modified oil according to claim 1, wherein the acid value of the recycled vegetable oil is 1 mgKOH / g or more.

3. 2. The modified oil according to claim 1, wherein the regenerated vegetable oil has an iodine value of less than 110.

4. 2. The modified oil according to claim 1, wherein the recycled vegetable oil is recycled used soybean oil.

5. The modified oil or fat according to claim 1, wherein the content of the specific compound is 0.1 to 7 parts by mass per 100 parts by mass of the recycled vegetable oil.

6. The method comprises a step of heat-treating a mixture of recycled vegetable oil and a specific compound, A method for producing modified oils and fats, characterized in that the specific compound is a reaction product or a modified product thereof of a novolak resin having an epoxy group and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms.

7. The method for producing modified oils and fats according to claim 6, wherein the amount of the specific compound added is 0.1 to 7 parts by mass per 100 parts by mass of the recycled vegetable oil.

8. The method for producing modified oils and fats according to claim 6 or 7, wherein the acid value of the recycled vegetable oil is 1 mgKOH / g or more.

9. The method for producing modified oils and fats according to claim 6 or 7, wherein the regenerated vegetable oil has an iodine value of less than 110.

10. 8. The method for producing modified oils and fats according to claim 6 or 7, wherein the recycled vegetable oil is recycled used soybean oil.

11. An ink composition comprising the modified oil or fat according to any one of claims 1 to 5.

12. The ink composition according to claim 11, which is for offset printing.

13. A method for producing an ink composition, comprising a step of heat-treating a mixture containing recycled vegetable oil and a specific compound, A method for producing an ink composition, characterized in that the specific compound is a reaction product or a modified product thereof of a novolak resin having an epoxy group and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms.

14. A method for suppressing the formation of precipitates and / or solidification of recycled vegetable oil at low temperatures by adding to the recycled vegetable oil a reaction product or a modified product thereof of a novolac resin having an epoxy group and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms.

15. When preparing an ink composition using recycled vegetable oil, When a reaction product or a modified product thereof of a novolak resin having an epoxy group and a polyester compound obtained by condensing a monohydroxy fatty acid having 12 or more carbon atoms is referred to as a specific compound, A method for suppressing the formation of precipitates and / or solidification at low temperatures in an ink composition containing recycled vegetable oil, characterized by using recycled vegetable oil containing the specific compound.

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