JPH07121612B2 - Copy material - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to recording materials, especially pressure sensitive copying materials.

[Prior Art] Conventionally, a colorless electron-donating color former (hereinafter referred to as "color former") is incorporated in a microcapsule film in the form of a solution and applied to one surface of another paper, and the other surface Apply an electron-accepting substance (hereinafter referred to as "developing agent"), such as clay or polymer material, which has the property of reacting with a color-forming agent to develop a color, and when using, stack these surfaces facing each other. Together,
2. Description of the Related Art Recording materials of the type in which copy recording is performed by applying pressure, that is, pressure-sensitive copying paper is known.

The copying and recording mechanism of this kind of recording material is a developer applied to the surface of the paper which is placed facing the surface, by cleaving the microcapsule film by pressure such as writing pressure and type pressure, releasing the color developer solution. It develops color by contact with.

There is also known a recording material in which each coating layer having such a color-developing mechanism is laminated and coated on one side of one sheet of paper with a microcapsule layer as an inner layer and a developer layer as an outer layer. The coloring mechanism of this recording material is that the microcapsule film is cleaved by a writing pressure, a typing pressure, etc., the color-developing solution is released, and the color is developed by contacting the color-developing agent applied to the outer layer.

The color former solution used for these recording materials is a solution prepared by dissolving an electron-donating color former in one or more hydrophobic solvents. The hydrophobic solvent used here must satisfy the following requirements.

That is, there is no toxicity, there is no unpleasant odor, the solvent itself is colorless or very pale color, it is non-volatile, the solubility of the color former is good, and the solution of the colorant is dissolved. Stability, stable microdispersion during microencapsulation, formation of microcapsule coating on the microdispersion, storage stability of microcapsules, coating material for microcapsules It can be applied uniformly and at a desired pressure on the top, it does not interfere with the color reaction that occurs when the color developer contacts the color developer, and the color development speed is fast, and paper coated with a polymer material is used as the color developer. In that case, the polymer material is also dissolved to make the color-forming agent contact closely, the color image is clear without blur, and a clear color image can be obtained even after long-term storage.

Conventionally, chlorinated diphenyl, which has been widely used as a solvent for recording materials of this kind, is extremely toxic and accumulates in the human body to cause various disorders. It becomes a serious problem when it is always handled by hand like a pressure-sensitive copying material coated with and is not used at present. As an alternative to this, 1-
Phenyl-1-xylylethane, 1-phenyl-1-
Aromatic hydrocarbon oils having two or three aromatic rings such as diarylalkanes such as (ethylphenyl) ethane, alkylnaphthalene, alkylbiphenyl, and partially hydrogenated terphenyl are used.

However, these solvents are expensive, and in order to inexpensively produce pressure-sensitive copying paper, it is widely practiced to mix and use a cheaper auxiliary solvent with the above solvent.

Further, although some of the above solvents have a high viscosity, if a high viscosity oil is used as it is, it is difficult to control the particle size at the time of encapsulation, and further, the fluidity of the color developer solution released from the capsule at the time of pressure printing is high. Poor color development performance due to poor performance. Even in such a case, the above-mentioned auxiliary solvent is used to adjust the viscosity, whereby the particle size at the time of encapsulation can be easily adjusted, and the color forming performance is further improved.

Chlorinated paraffin oil is also used as an inexpensive solvent in some areas. However, chlorinated paraffin oil has a high viscosity and is generally used by mixing with a lower viscosity auxiliary solvent.

As auxiliary agents, in addition to petroleum-based solvents such as kerosene, isoparaffin-based solvents, normal paraffin-based solvents, C _{10 to} C ₁₃
The straight chain alkylene and the like are widely used.

However, the solvent obtained by mixing these auxiliary solvents has various problems. In other words, since paraffinic solvents such as kerosene, isoparaffin, and normal paraffin have poor solubility of the color former, the concentration of the colorant is restricted by mixing these, and the stability of the solution is lowered by causing recrystallization. . Further, these auxiliary solvents have a low dissolving power of the color developer when a polymer material such as phenol resin is used as the color developer, and therefore, when used together with a low-viscosity main solvent,
Even when used in combination with a high-viscosity oil, the color developability is not improved but may be lowered. Further, linear alkylbenzenes also have drawbacks such as a decrease in dye solubility and a slow color development speed, and they are expensive.

Aromatic hydrocarbon oils such as low-boiling alkylbenzene and alkylnaphthalene have excellent solubility and color-developing properties of the color former, but have strong odor and are not suitable for use as an auxiliary solvent.

[Problems to be Solved by the Invention] An object of the present invention is to solve the above-mentioned problems of the prior art, to provide a copying material having excellent coloring performance, and at the same time to achieve economical cost. To do. More specifically, the object of the present invention is to solve the drawbacks of the main solvent and auxiliary solvent conventionally used as a dye solvent for copying materials, for example, pressure-sensitive copying paper, to provide excellent coloring properties, and to make inexpensive copying. To provide the material.

[Means for Solving Problems] The above object of the present invention is to provide a copying material using a solution in which an electron-accepting developer and an electron-donating color developer which develops a color by contacting the developer are dissolved. In the above solvent, (A) mainly contains components contained in a boiling range of 160 to 260 ° C. (converted to normal pressure), and substantially naphthenic hydrocarbons,
Consisting of isoparaffins and tetralin hydrocarbons,
And the content of naphthenic hydrocarbons is 50-80% by weight, the content of tetralinic hydrocarbons is 2-15% by weight, the content of isoparaffins is 10-40% by weight, and the content of alkylbenzenes and alkylnaphthalenes is 5% by weight. % Or less, 5 to 40% by weight of a hydrocarbon mixture oil having a normal paraffin content of 10% by weight or less, and (B) at least 2 non-condensed or condensed aromatic rings.
It is achieved by the copying material of the present invention, which comprises 60 to 95% by weight of one or more hydrocarbon oils or chlorinated paraffin oils having a normal boiling point of 260 ° C. or more.

[Operation] The present invention will be described in more detail below.

The solvent used in the present invention has a specific boiling point range and needs to contain a specific component. First, regarding the boiling point range, it is necessary that the solvent is a hydrocarbon mixture oil that mainly contains components whose boiling point in terms of atmospheric pressure is in the temperature range of 160 to 260 ° C. When a component having a boiling point of less than 160 ° C is used as a solvent, the color development rate of the copying material is high, but the odor is large and it cannot be put to practical use. Also, since the vapor pressure is high,
It becomes more flammable and has a safety problem. Fractions above 260 ° C have a small odor and are preferable in the work environment,
Reduces color development speed. The solvent is then a hydrocarbon mixture oil consisting essentially of naphthenic hydrocarbons and isoparaffins, and tetralinic hydrocarbons. The content of the naphthenic hydrocarbons in the solvent needs to be 50 to 85% by weight. If it is less than 50%, it lowers the solubility of the color former when used as an auxiliary solvent, and further lowers the color development speed of the copying material when a phenol resin is used as the developer. If it exceeds 85%, the odor becomes worse. Due to the presence of isoparaffin, the solvent of the present invention has excellent odor and viscosity reducing effects, but if it is less than 10%, such an improving effect cannot be obtained. On the other hand, when it exceeds 40%, the effect of reducing odor and viscosity is excellent, but the solubility of the phenol resin as a color developing agent and a color developing agent decreases, and the color developing rate decreases. The presence of the tetralin hydrocarbon makes the phenol resin as a color-developing agent and a color-developing agent excellent in solubility, and contributes to the improvement of the color-developing rate. Here, what is defined as a tetralin hydrocarbon includes tetralin, alkyltetralines, indane, and alkylindanes. If it is less than 2%, the dissolving power is insufficient, and if it exceeds 15%, the solubility is excellent, but the odor is deteriorated. Less normal paraffins and alkylbenzenes and alkylnaphthalenes are desirable for the present invention. That is, since normal paraffin is easily crystallized, it is necessary to set it to 10% or less for the present invention. Aromatic hydrocarbons such as alkylbenzenes and alkylnaphthalenes are excellent components in terms of solubility in a color former and phenol resin as a developer, which is a desirable component from the viewpoint of improving color development characteristics, but in terms of odor and toxicity. From the above, it is desirable that the amount be small, and in the present invention, it is necessary that the amount be 5% or less. The present invention, as described above, includes alkylbenzenes,
The content of aromatic hydrocarbons such as alkylnaphthalenes is reduced as much as possible to solve the problems of odor and toxicity, and it consists essentially of naphthene hydrocarbons, tetralin hydrocarbons and isoparaffins. By mainly defining the components and by defining the content, the dissolving power is large even if aromatic hydrocarbons such as alkylbenzenes or alkylnaphthalenes are not substantially contained, and it is superior to the above-mentioned paraffinic solvent. Excellent solubility and color development characteristics are obtained. In addition, compared to low boiling aromatic hydrocarbon oil,
Excellent characteristics such as odor is extremely small. Therefore, each component and its content have important significance.

Next, the method for producing the solvent used in the present invention will be described. The solvent of the present invention can be obtained by mixing each component compound having a specific boiling point, but such a method is not always economical. A preferred manufacturing method is as follows. That is, 160 to 2 mainly obtained by distilling crude oil
A fraction obtained by desulfurization and / or denitrification and / or hydrorefining for deolefinized hydrocarbons, which is a fraction contained in the boiling point range of 60 ° C., and then obtained by adsorption separation of normal paraffins, Specifically, it is a method for obtaining a fraction composed of naphthene hydrocarbons, tetralin hydrocarbons and isoparaffins. The distillate having a boiling point (converted to atmospheric pressure) of 160 to 260 ° C obtained by distilling crude oil corresponds to a so-called straight-run kerosene fraction or a straight-run via fraction, such as normal paraffins and isoparaffins. And naphthenic hydrocarbons and aromatic hydrocarbons. Their composition depends on the place of production of crude oil. For producing the solvent used in the present invention, a fraction obtained from any crude oil can be used, but it is preferable to use a fraction obtained from a crude oil rich in naphthene hydrocarbons and naphthalenes.

The fraction is then subjected to hydrorefining. The straight run fraction obtained by distilling crude oil generally contains sulfur compounds, nitrogen compounds and olefin compounds as impurities. Such a sulfur compound, or a fraction obtained by separating normal paraffin from a fraction containing a nitrogen compound and an olefin compound has a strong odor and is not suitable for use.
It is necessary to carry out desulfurization, denitrification and deolefinization by hydrorefining. In addition, the impurities described above interfere with the normal paraffin separation process. In particular, when the adsorption separation method using synthetic zeolite is used, the activity of the adsorbent is remarkably reduced, and therefore it is necessary to remove it. The purification step is
This is carried out in order to remove the above-mentioned sulfur compounds, nitrogen compounds and olefin compounds contained in the straight distillation fraction. Hydrorefining is carried out by a conventional method. That is, as the catalyst, Co-Mo system, Ni-Mo system, Ni-Co-Mo system, Ni-W system catalyst and the like are used, and the reaction temperature is 260 to 430 ° C and the pressure is 20 to 100 Kg /
cm ² , LHSV 0.5-10, hydrogen ratio 50-500 Nm ³ / kl. In this hydrorefining step, in addition to the desulfurization, denitrification, and deolefinization reactions, some aromatic hydrocarbons are nuclear hydrogenated, and some naphthalene compounds are converted to tetralin compounds,
Also, some alkylbenzenes are converted to naphthenes.
Impurities contained in the fraction after hydrorefining, total sulfur 1ppm or less, total nitrogen 1ppm or less, bromine index 100mg / 1000
It is preferably g. As a method for separating the normal paraffin, a conventional method such as a crystallization separation method, a urea adduct method, an adsorption separation method using a synthetic zeolite, or the like can be used. The adsorption separation method using a synthetic zeolite is a particularly preferable method, and the UUC's isosieve method 1 UOP's Molex method and the like are preferably used. It is necessary for the performance of the solvent of the present invention that the residual normal paraffin in the extraction residual oil is 10% by weight or less. The normal paraffin extraction oil thus obtained is essentially composed of naphthene hydrocarbons, isoparaffins, and tetralin hydrocarbons. The extraction residual oil can be used as it is as the solvent of the present invention, but if necessary, further distilled off,
It can also be used as a fraction having an appropriate boiling point range. The solvent of the present invention has various main solvents that are currently generally used as a solvent for a color forming material of a pressure-sensitive copying material, for example, at least two non-condensed or condensed aromatic rings,
When used in combination with an aromatic hydrocarbon oil having a boiling point of 260 ° C or higher, or chlorinated paraffin oil, etc., the synergistic effect is that the solubility of the color former and the solubility of the phenolic resin as the developer are markedly improved, resulting in pressure sensitivity. It exhibits particularly excellent performance in terms of improving the coloring performance of the copying material and economic effects.

As the non-condensed or condensed type hydrocarbon oil having two or more aromatic rings, those having a boiling point (at atmospheric pressure) of 260 ° C. or higher are desirable, such as phenylnixylilethane, phenylniethylphenylethane, and phenyl. = Isopropylphenylethane, isopropylphenyl = phenylmethane, phenyl = butylphenylmethane, benzylxylene, benzyl = ethylbenzene and other diarylalkanes, diisopropylnaphthalene and other alkylnaphthalenes, isopropylbiphenyl, sec-butylbiphenyl, cyclohexylbiphenyl and other alkyl or cyclo groups. Alkyl biphenyl, partially hydrogenated terphenyl (trade name HB-4
0), dibenzyltoluene, di (α-methylbenzyl)
Triaryl dialkanes such as benzene, di (α-methylbenzyl) xylene, dibenzyl benzene, triaryl alkanes such as diphenyl xylyl butane, naphthyl aryl alkanes such as benzyl naphthalene, α-methyl benzyl naphthalene, benzyl tetraline, α −
Partially hydrogenated condensed ring aromatic aryl alkylated products such as methylbenzyl tetralin can be mentioned.

The number of aromatic rings contained in the aromatic hydrocarbon oil used in combination is preferably at most 3, and when it is 4 or more, the viscosity is high. Therefore, even if the solvent of the present invention is used in combination, the color forming property is low and it is not suitable for practical use.

As the chlorinated paraffin oil, one obtained by chlorinating normal paraffin and having 10 to 14 carbon atoms per molecule and a chlorine content of 30 to 60% by weight is preferably used.

When used in combination with the main solvent and the solvent used in the present invention, the mixing ratio is preferably 5 to 40% of the solvent used in the present invention to the main solvent 60.
˜95%, more preferably 5 to 30% vs 70 to 95%.
When the amount of the solvent of the present invention is less than 5%, the color development performance of the pressure-sensitive copying material to be obtained is improved, or the economic effect due to the combined use is poor.
On the other hand, if it exceeds 40%, the solubility of the color former decreases, so that the stability of the color developer solution decreases, and recrystallization and precipitation of the color former may occur. When it is 40% or more, when a phenol resin is used as a color developer, the solubility of the resin is lowered and the color development performance is also likely to be lowered.

The copying material of the present invention is appropriately produced by using a solution prepared by dissolving an electron-accepting developer and a colorless electron-donating color former which develops a color upon contact with the developer in a solvent used in the present invention. .

Here, as the electron-accepting developer, bentonite, zinc oxide, titanium oxide, kaolin, clay, activated clay, acid clay, zeolite, talc, colloidal silica and the like, and phenolic resins whose use is increasing in recent years And the like, and aromatic carboxylic acids such as salicylic acid, derivatives thereof, polymers thereof, and metal salts thereof such as zinc.

As a colorless electron-donating color developing agent that develops a color by contacting with the color developing agent, a trial methane compound, a diphenyl methane compound, a xanthene compound, a thiazine compound, a spiropyran compound or the like is used. More specifically, methyl violet, crystal violet, malachite green, rhodamine B, O-hydroxybenzalacetophenone, Michler's hydrol derivative, pyromellitic indole derivative, florane derivative, azo blue black, nigrosine, oil black, sudan. III, Sudan IV and the like.

The color former is used by dissolving it in the solvent used in the present invention, and the dissolved amount thereof is about 0.5 to 15% by weight.

Taking a pressure-sensitive copying material, for example, a pressure-sensitive copying paper as an example of the copying material of the present invention, a general manufacturing method thereof will be described. A solution of the above-mentioned color former in a solvent used in the present invention is mixed with gelatin and gum arabic. It is emulsified and dispersed in an aqueous solution, and then a gelatin film is formed around oil droplets emulsified by the coacervation method. Alternatively, a method of forming a resin film by an interfacial polymerization method, an in-situ polymerization method, or the like is often used.
The pressure-sensitive copying paper is manufactured by applying the thus-produced capsule emulsion of fine oil droplets to a paper, and applying the above-mentioned color developer in layers on the surface of the paper facing the application surface or on the application surface.

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

Example (a) Production of solvent used in the present invention A kerosene fraction having a boiling point range of 179 to 260 ° C, obtained by distilling Minas crude oil, was subjected to hydrorefining. The hydrorefining is carried out using a Ni-W catalyst at a temperature of 280 ° C, a pressure of 80 Kg, LHSV = 1, and a hydrogen ratio of 300.
It was carried out under the condition of Nm ³ / Kl oil. The obtained hydrogenated refined oil had a sulfur content of 1 ppm or less, a nitrogen content of 1 ppm or less, and a bromine index of 40.
The hydrorefined oil was then treated with a molecular sieve 5A from Linde to separate normal paraffins. Separation condition is temperature 18
The temperature was 0 ° C., the pressure was 25 kg, and LHSV = 1. Then, the extracted residual oil is distilled to obtain a fraction having a boiling point range of 183 to 230 ° C., which is used as the solvent (1) of the present invention. Similarly, boiling point 210-2 by distillation
A fraction at 45 ° C. is obtained, which is designated as solvent (2) according to the invention.
These properties are also shown in Table 1.

Table 1 Solvent of the present invention Solvent of the present invention (1) (2) Distillation properties (° C) Initial distillation 183 210 End point 230 245 Composition (wt%) Normal paraffins 2 7 Isoparaffins 20 24 Naphthene hydrocarbons 66 54 Tetralin-based hydrocarbons 9 11 Aromatic hydrocarbons 3 4 Sulfur content (ppm) 1 or less 1 or less Nitrogen content (ppm) 1 or less 1 or less Viscosity (CS @ 40 ℃) 1.3 1.9 (a) Solubility test of color former Color development The effect of the solvent of the present invention on the dye solubility was investigated using crystal violet lactone for blue as an agent. The test method was as follows. That is, as the main solvent, phenyl nixyl ethane "Nisseki Hysol SAS-29
6 "(trade name, manufactured by Nippon Petrochemical Co., Ltd.), a coloring agent was added to a mixed solvent containing various solvents in an amount of 1% from 4% to 7%, dissolved by heating, and then left at room temperature. , The phenomenon of recrystallization was observed. The results are shown in Table 2. In Table 2, phenyl xylylethane alone is a reference example, and isoparaffin solvent "Isoparal H" (trade name) and kerosene are comparative examples.

As is clear from Table 2, the solvent used in the present invention is unlikely to reduce the solubility of the color former unlike conventional auxiliary solvents.

(C) Manufacture of pressure-sensitive copying paper (C-a) Phenyl xylylethane was used as the main solvent, and the solvent prepared by mixing the solvent prepared in (A) was mixed with crystal violet lactone as a coloring agent.
% Dissolved to obtain a color developer solution.

The solution was then microencapsulated. Microencapsulation was performed by a conventional method by in-situ polymerization using urea and formalin. A sizing agent and a protective material were added to the obtained microcapsule emulsion, which was applied to woodfree paper using a wire bar to obtain an upper leaf paper of pressure-sensitive copying paper. Further, a lower leaf paper coated with a phenol-formaldehyde resin as a color developer was prepared.

(U-b) Diisopropylnaphthalene "KMC-R" (Kureha Chemical Industry Co., Ltd., trade name) is used as the main solvent, and the solvent (1) used in the present invention produced in (A) is used in combination. A pressure-sensitive copying paper was prepared in the same manner as in (a).

(U-c) Using sec-butylbiphenyl as the main solvent, mixing the solvent produced in (A), (U-a)
A pressure sensitive copy paper was prepared in the same manner.

(U-d) Di (α-methylbenzyl) benzene was used as the main solvent. The solvent prepared in (a) was mixed with this to prepare a pressure-sensitive copying paper in the same manner as in (u-a).

For comparison, in each case of (u-a) to (u-d), an upper paper was made in the same manner by using an isoparaffin solvent (trade name "ISOPAR-H") in combination with each main solvent. .
In the case of (u-a), comparison was also made when kerosene was used in combination.

(D) Measurement of color development speed and color density Overlay the microcapsule application surface of the upper leaf paper with the developer application surface of the lower leaf paper, and use a high pressure press to obtain the upper leaf paper and lower leaf paper from each solvent. The same load was applied to each of the paper combinations to develop color.

The reflectance of the lower leaf paper 1 minute and 1 hour after the loading was measured using a reflection type spectrophotometer.

Table 3 shows the results when phenyl xylylethane was used as the main solvent. As can be seen from the table, the solvent used in the present invention is different from the conventional paraffinic solvent or kerosene, and has an improving effect without impairing the coloring performance.

Table 4 shows the results when diisopropylnaphthalene was used as the main solvent. In the case of diisopropylnaphthalene, the effect of improving the coloring performance of the solvent used in the present invention is more remarkable than in the case of phenyl = xylylethane.

Further, Table 5 shows the results when sec-butylbiphenyl or di (α-methylbenzyl) benzene was used as the main solvent. In any case, it can be seen that the color development performance is improved by using the solvent of the present invention. In particular, when di (α-methylbenzyl) benzene, which is a tricyclic aromatic hydrocarbon, is used as the main solvent, the degree of improvement effect is more remarkable than that of phenyl xylylethane.

In addition, chlorinated paraffin oil "Empara K-45" (manufactured by Ajinomoto Co., Inc., trade name) is used as the main solvent.
Table 6 shows the results when tested in the same manner as in (d).
Also in this case, it can be seen that the color development performance is improved by using the solvent of the present invention together.

EFFECTS OF THE INVENTION (A) A hydrocarbon mixture oil having a specific boiling point range and a specific component composition, which has been conventionally used as a dye solvent for a pressure-sensitive copying material (B) a non-condensation type Alternatively, the present invention which uses a solvent in which one or more specific amounts of hydrocarbon oil or chlorinated paraffin oil having a standard boiling point of 260 ° C. or higher and having at least two condensed aromatic rings is used in combination with a conventional solvent Compared with the copying material used, it has the following characteristics and effects.

(1) The pressure-sensitive copying material can be manufactured at a lower cost than that in the case of using expensive two-ring or three-ring aromatic hydrocarbon oil alone, and the economical effect is excellent.

(2) The solubility of the color former is less likely to decrease as compared with the case where conventionally used isoparaffin, norparaffin, kerosene, linear alkylbenzene or the like is used in combination with the main solvent. Further, even when a polymer material such as phenol resin is used as a color developer, the color development performance is less likely to deteriorate, and when the main solvent has a high viscosity, the color development performance is improved by the combined use.

(3) Unlike the case of using an aromatic hydrocarbon having a low boiling point such as alkylbenzene or alkylnaphthalene, it has less odor and less toxicity.

Claims (4)

[Claims] 1. A copying material using a solution in which an electron-accepting color developer and an electron-donating color developer which develops a color upon contact with the color developer are dissolved, wherein the solvent is (A) 160- It mainly contains components contained in the boiling point range of 260 ° C (at atmospheric pressure), and is essentially naphthenic hydrocarbons,
Consisting of isoparaffins and tetralin hydrocarbons,
And the content of naphthenic hydrocarbons is 50-80% by weight, the content of tetralinic hydrocarbons is 2-15% by weight, the content of isoparaffins is 10-40% by weight, and the content of alkylbenzenes and alkylnaphthalenes is 5% by weight. % Or less, 5 to 40% by weight of a hydrocarbon mixture oil having a normal paraffin content of 10% by weight or less, and (B) at least 2 non-condensed or condensed aromatic rings.
A copying material characterized by comprising 60 to 95% by weight of one or more hydrocarbon oils or chlorinated paraffin oils having a normal boiling point of 260 ° C or more. 2. A copying material according to claim 1, characterized in that the hydrocarbon mixture mainly contains components in the boiling range of 180 to 230 ° C. 3. A copying material as claimed in claim 1, characterized in that the hydrocarbon mixture mainly comprises components in the boiling range from 210 to 250 ° C. 4. A copying material according to any one of claims 1 to 3, wherein the copying material is a pressure-sensitive copying material.