JP2006102952A - Thermal recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal recording medium which has high sensitivity, whiteness and excellent resistance to head tailings deposition and sticking, while utilizing waste, considering environments. <P>SOLUTION: In the thermal recording medium with a heat-sensitive color development layer which contains a colorless or pale-color basic colorless dye and an organic developer as main components, formed on a support, a porous particle containing an incineration ash discharged from incineration facilities, contained in a particle of a substance selected from the group consisting of silicic aid, silicate and a mixture thereof, is added. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat-sensitive recording material utilizing a color development reaction between a basic colorless dye and an organic developer.

In general, a heat-sensitive recording material having a heat-sensitive color developing layer mainly composed of a colorless or light-colored dye precursor and a color developer that reacts with the dye precursor when heated is disclosed in Japanese Patent Publication No. 45-14039, Widely used. A thermal printer with a built-in thermal head is used for recording on this thermal recording medium, but such a thermal recording method has no noise during recording compared to other recording methods that have been put to practical use. With the development of the information industry, with the development of the information industry, development and fixing are not necessary, maintenance is free, the equipment is relatively inexpensive and compact, and the resulting color development is very clear. Widely used for various measuring instruments and labels. As these recording apparatuses become more diversified and higher performance is required, the required quality of the thermal recording medium has become higher. With respect to the color development sensitivity, it is required that a clear color image with a high density can be obtained even with a small amount of heat energy as the apparatus is miniaturized and the recording speed is increased.
In order to satisfy these requirements, for example, Japanese Patent Laid-Open No. 56-169087 discloses a method for increasing the color development sensitivity by adding a heat-soluble substance in the heat-sensitive layer, and Japanese Patent Laid-Open No. 56-144193 discloses a color developing ability. Although a method of increasing the color development sensitivity by using a high novel developer is described, all of them have deteriorated heat resistant ground color, dusting with time, and when printing after storing the uncolored part for a long time Since it has defects such as a decrease in color density (reprintability), it cannot be said that the quality is sufficient. In general, a method in which an appropriate sensitizer is used in combination with a dye and a developer is known. For example, when the developer is a phenol compound represented by bisphenol A, p-benzylbiphenyl (special Kaisho 60-82382), benzyl p-benzyloxybenzoate (Japanese Patent Laid-Open No. 57-201691), benzyl naphthyl ether (Japanese Patent Laid-Open No. 58-87094) and the like are used as suitable sensitizers.

In such heat-sensitive recording paper, the above dye, developer, and sensitizer are usually atomized and a recording layer is formed using a binder such as PVA as a binder. For this reason, when recording is performed with heat by bringing the recording head or the like into contact with the recording layer, the components in the recording layer melt and adhere to cause sticking or sticking to the recording head or the like. In order to prevent this, various fillers are included in the recording layer. Among them, when amorphous silica is contained in the recording layer as a filler for thermal recording paper, the surface activity of the silica promotes the reaction between the leuco dye and phenols, thereby producing background color (background fogging). There's a problem.
In order to prevent this, Japanese Patent Publication No. 2-1030 (Patent Document 1) discloses a particle size of a secondary particle size in which a particle size of 4 μm or less is 90% by weight or more as measured by a centrifugal sedimentation method. There has been proposed a thermal recording paper filler comprising finely divided amorphous silica having a distribution and a BET specific surface area of 10 to 100 m ² / g and a bulk density of 0.14 to 0.30 g / ml.
Japanese Patent Publication No. 2-1030

The fine particle amorphous silica solves the above-mentioned problems. However, since silica generally has an active group such as a hydroxyl group on its surface, it is difficult to increase the viscosity of the coating solution. When used as a filler for coating, the coating operation must be performed with a lower filler concentration in the coating solution than calcium carbonate, calcined kaolin, etc., and it takes time to dry. In terms of performance and recording paper production cost, it is not yet satisfactory.
In addition, for example, baked kaolin is used between the recording layer and the support to prevent the adhesion of head debris and increase the sensitivity, but with rapid printer progress (especially speeding up). Therefore, there is a need for a heat-sensitive recording material having more excellent residue adhesion prevention and sticking prevention properties.
In recent years, environmental protection has become an important social issue, and in the field of thermal recording materials, it is necessary to recycle and not use harmful substances. However, it is not easy to link these efforts to practical use. For example, if you try to reuse incinerated ash discharged from combustion facilities such as boilers, which are normally considered as waste, they are colored. Problems such as deterioration of the background color of the thermal recording medium occur.
Therefore, an object of the present invention is to provide a thermal recording material that is excellent in waste adhesion prevention and sticking prevention, has good whiteness, and can form a high density image while effectively using waste in consideration of the environment. It is to provide.

  As a result of intensive studies by the present inventors, the above-mentioned problem is obtained in a thermal recording medium provided with a thermal coloring layer containing a colorless or pale basic colorless dye and an organic developer as main components on a support. By containing in the heat-sensitive recording medium porous particles in which the incinerated ash discharged from the combustion facility is included in particles of a substance selected from the group consisting of silicic acid, silicates and mixtures thereof Achieved.

According to the present invention, incineration ash discharged from combustion facilities such as boilers that have been normally disposed of can be effectively used, and the environmental burden can be reduced. Moreover, a highly oil-absorbing material can be used without causing deterioration of workability such as thickening of the coating liquid. Further, it has excellent effects of preventing sticking adhesion, anti-sticking and whiteness, and is capable of forming a high density image with high sensitivity.
In the thermosensitive recording material of the present invention, the reason why the excellent effect is obtained is not clearly clarified, but the porous particles used in the present invention are encased in a substance in which the incinerated ash is made of silicic acid or silicate. Therefore, the color is concealed and the whiteness is not lowered even if it is used for a heat-sensitive recording material. Moreover, compared with general silica, activity is suppressed by being combined with incineration ash, and it is considered that the viscosity of the coating solution is improved. In addition, it has a high heat insulation effect, improves color development sensitivity, and has excellent adsorptivity with dyes, color developers, and sensitizers. be able to. Furthermore, since it has a very large oil absorption amount, it absorbs excessive coloring material that melts by the heat from the thermal head during recording at a high concentration, so that adhesion of the melt to the thermal head is suppressed, and It is assumed that the occurrence of sticking is prevented.

Next, the present invention will be described in more detail.
In order to obtain the heat-sensitive recording material of the present invention, porous ash in which incinerated ash discharged from a combustion facility is included in particles of a substance selected from the group consisting of silicic acid, silicates, and mixtures thereof. It is necessary to contain the body. In the present invention, in addition to the thermosensitive coloring layer, an undercoat layer such as a polymer material containing a filler between the support and the thermosensitive coloring layer for the purpose of enhancing the coloring sensitivity, and a thermochromic layer for the purpose of enhancing the storage stability. In addition, a protective layer of a polymer substance or the like, and a single layer or a plurality of intermediate layers may be provided between the thermosensitive coloring layer and the protective layer, and the porous particles are contained in at least one of these layers.
The porous particles used in the present invention are those disclosed in JP-A-2003-71404. Immersion treatment refers to a treatment in which incinerated ash is mixed with a solution in which silicic acid is dissolved under alkaline conditions, and this is neutralized with acid to precipitate silicic acid, etc. Inclusion includes incineration ash, etc. A state in which a part of the surface is covered with silicic acid or the like.

The porous particles used in the present invention include aggregates of particles such as silicic acid and calcined ash particles, aggregates of silicic acid particles, and extremely small amounts of incinerated ash particles (silicic acid, silicates and their Not included in the mixture. That is, at least most of the incinerated ash particles are contained in particles such as silicic acid, and is a concept that includes the form of powder or granulated material. Moreover, oil absorption, a specific surface area, whiteness, etc. are improved from incineration ash. Furthermore, by including incinerated ash in particles such as silicic acid, these various performance improvements are larger than those obtained by simply mixing incinerated ash and particles such as silicic acid.
The incineration ash that is the raw material is coal incineration ash, sludge incineration ash from the papermaking process, and the former refers to coal scum generated in boilers and the like. The composition is very complicated and is composed of various metals and their oxides, sulfides, chlorides, etc., but they differ depending on the production area and cannot be expressed in general terms. Furthermore, in addition to organic substances in coal such as unburned carbon or in sludge, halogens and even heavy metals are included. In the latter, sludge generated from the papermaking process is made from incineration residues such as kilns and heat recovery boilers, and the composition is calcium carbonate, titanium dioxide, talc, kaolin, etc. discharged from the used paper recycling process and papermaking white water. Inorganic pigments, bands that are inorganic flocculants, and some ink components and fibers. All the incineration ash changes with place, time, etc., and it is impossible to express a uniform composition. However, incineration ash generated from any process can be included in particles such as silicic acid, and any of them can improve whiteness. Therefore, porous particles can be formed regardless of combustion conditions such as incineration temperature, time, boiler shape, and the like. However, since the whiteness of the finished granulated product greatly depends on the whiteness of the incinerated ash, it is better to remove the coloring components as much as possible. The coal ash has a particle size of approximately 30 μm or less for fly ash and a size larger than that for bottom ash, but any size and shape can be used. This is presumably because white carbon is composed of a lump of fine particles such as silicic acid called primary particles, and the primary particles aggregate with incineration ash as a nucleus. Furthermore, when using papermaking sludge ash, since white carbon was attached to all particles, even when using inorganic pigments such as calcium carbonate, talc, kaolin, and clay, and fillers in addition to incinerated ash, Porous particles contained in particles such as silicic acid can be created.

Next, it is preferable to use silicic acid as a starting material which exists in a dissolved form in an alkaline solution such as sodium or potassium. This is because sodium silicate precipitates silicic acid by neutralization with acid to form white carbon which is amorphous silicic acid. Furthermore, any ratio of silicon dioxide and sodium oxide in sodium silicate may be used. Commonly available sodium silicate may have a silicon dioxide to sodium oxide molar ratio of about 3: 1, referred to as No. 3 silicon. The sodium silicate concentration at the time of charging is preferably in the range of 0.5 to 25% as SiO ₂ , but if it is too thin, it is not industrially advantageous. As the acid used for neutralization, mineral acid, which is an inorganic acid, is often used as a standard method for producing white carbon. This mineral acid is a general term for inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, and bands. However, there is no problem as long as both include incinerated ash and an amorphous substance can be formed around the ash by silicic acid or the like.

  In the manufacturing method, incineration ash is immersed in alkaline silicate soda to obtain a suspension. In this case, there is no problem whether the coal incineration ash and the sludge incineration ash are independent or mixed. Further, when the incineration ash charging rate (incineration ash weight / white carbon weight) is lowered, the characteristics as white carbon become remarkable, and the whiteness and oil absorption increase. On the contrary, if the amount is decreased, the whiteness and oil absorption will decrease, but the whiteness and oil absorption will be improved compared to the case of incineration ash alone. Thus, the porous granule containing incineration ash can be configured with a large or small incineration ash input rate, and each has its own characteristics, so that the incineration ash input rate is silicic acid or silicic acid. Inclusion with particles such as silicic acid is possible within a wide range of 0.5 to 99.5% by weight with respect to the salt. Furthermore, a preferable incineration ash charging rate is 0.5 to 90%. Inclusion with particles such as silicic acid is not completely carried out when the incineration ash charging rate increases, but the oil absorption and wire wear are improved compared to the incineration ash alone. Moreover, it is preferable to inject incineration ash into the sodium silicate before neutralization by an acid is performed. However, in order to constitute the porous particles used in the present invention, it is not necessary to perform neutralization with this acid, and there is no problem if incinerated ash is introduced under alkaline conditions. This should just be pH 7-14 or more, More preferably, it is pH 10-1414. On the other hand, if the incineration ash is introduced in a state where the neutralization has progressed too much, inclusion with particles such as silicic acid, which is the present invention, centering on the incineration ash becomes difficult.

The suspension thus prepared is brought to an appropriate temperature, acid is added dropwise with stirring, and the mixture is thoroughly mixed. In addition to mineral acids such as sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid, the acid may be organic acids such as acetic acid, oxalic acid, citric acid, and carbonic acid. Furthermore, metal-containing acids including alkali metals and alkaline earth metals may be used, and there is no problem with bands, iron chloride, zinc sulfate, or the like. The concentration does not matter if it can be mixed so that silicic acid does not become a gel. However, when a thin acid of 0.1 N or less is used, the total volume of the suspension is extremely increased by neutralization. Therefore, an appropriate acid concentration of 0.1N or more is necessary, and if possible, an acid having an acid concentration of 1N or more, such as concentrated sulfuric acid, is preferable. What should be noted here is that, when an acid having a high concentration of 1N or more such as the above-described concentrated sulfuric acid is used, it is necessary to perform sufficient stirring. If this is neglected, the suspension becomes a gel and it becomes difficult to take the form of particles, so care must be taken. In addition, the whiteness and oil absorption of the finished product were changed by silicification with an acid containing a metal such as a band during neutralization. Here, silicic acid refers to silicon dioxide (including hydrates having no fixed composition), and silicate refers to general formulas xM ₂ O · ySiO ₂ , xMO · ySiO ₂ , xM ₂ O _3. A compound represented by ySiO ₂ , where M varies depending on the oxidation number. M is a metal such as Al, Fe ₂ , Ca, Mg, Na, and K. Further, a plurality of these metals may be contained, and the ratio can be arbitrarily set. The reason for this is not clear, but it is thought to be caused by the fact that the light reflectance increases by silicate formation and the distribution of micropores changes. In this way, the physical properties change depending on the type of acid, so there is no problem with the ratio of silicic acid and silicate, and by changing this ratio, the whiteness and oil absorption change, and each has a characteristic. A granular body with no

  The acid may be added all at once, but when the acid concentration is high, when the addition speed is increased, or when the agitation is not sufficiently performed, the alkali content is not sufficiently neutralized. It is better to add the acid in several times. In addition, when acid addition is carried out in several times, it is better to allow sufficient time for aging between the two so that sodium silicate and acid react sufficiently. This aging is a process in which neutralization is not performed and stirring by an agitator or a pump is performed so that the slurry does not settle, the sedimentation of the slurry is controlled, and an appropriate temperature is maintained to promote precipitation of particles such as silicic acid. Say. By adding an acid in several steps and further providing an aging step, porous particles including incinerated ash with particles such as silicic acid can be precipitated. Further, as disclosed in JP-A-8-91820, there is no problem even if a pulverization step is provided during the ripening and the particle size is controlled, and there is no problem at any ripening time.

  The granulated product formed by these reactions becomes a wide range of porous particles having an average particle size of 1 to 1000 μm according to the measurement result of the average particle size by the laser method. This average particle size is greatly affected by the size of the incinerated ash that is the starting material, and the granulated product when the incinerated ash containing a large amount of fine particles having an average particle size of about 1 to 30 μm, such as fly ash, is used as an average The particle size is 1 to 50 μm, but it is large when large incineration ash such as bottom ash is included. In the case of using a filler or pigment for a heat-sensitive recording material, it is preferable that the incinerated ash used as a starting material is subjected to pulverization and classification for each particle size to refine the average particle size to 10 μm or less. Preferably, the average particle diameter of the raw material is 0.1 to 5 μm, and the average particle diameter is 0.5 to 10 μm in a state of being covered by particles such as silicic acid. The pulverization is best performed by a method using a pulverizer, and the pulverization method may be either wet or dry. As the pulverizer used in the pulverization process, high-speed rotation such as a ball mill such as a ball mill and a rod mill, a medium agitating pulverizer such as a tower mill, an attritor, a satelite mill, a sand grinder and an annula mill, a colloid mill, a homomixer, an in-line mill, etc. In addition to the pulverizer, a dry pulverizer such as a jet mill may be used. Examples of classification using a sieve include a vibrating sieve, an ultrasonic sieve, a jet screen, an air separator, and a trommel screen. Further, this pulverization step may be carried out in a silicic acid slurry in which sodium silicate or sodium silicate is partially neutralized, and after the addition of sulfuric acid as shown in JP-A-8-91820, the first aging is performed. A technique that sometimes pulverizes to reduce the particle size is particularly suitable. The particles deposited in the present invention are fine, and the incinerated ash contained by the silica deposited in the first step can be pulverized by other types of dispersers and emulsifiers in addition to the above pulverizers. Can be used in combination with a pulverizer. The porous granules produced in this way contain by-produced sodium sulfate, and in order to remove this, filtration, washing with water and repulping are performed, so that part of the sodium sulfate is obtained. Can be removed. However, if there is no problem even if sodium sulfate is included in the purpose of use, there is no problem if it is used as it is. In addition, when drying is necessary due to problems such as transportation, it can be dried by heating or depressurizing, and even if repulping is performed again, the physical properties of the granulated product are hardly changed.

The porous particles thus obtained have an average particle size of 0.1 to 10 μm, and the oil absorption and whiteness are higher than the incinerated ash used as a starting material. Moreover, since silicic acid etc. exists on the incineration ash surface, the performance difference by the quality fluctuation | variation of the incineration ash used as a nucleus decreases, and industrial utilization becomes advantageous. This incinerated ash is contained in particles such as silicic acid, but there are a mixture of completely incinerated ash and a part of which the surface of the incinerated ash is exposed. Further, there are cases where incinerated ash is individually contained in particles such as silicic acid, and there are cases where several incinerated ash are contained in one particle after being treated with particles such as silicic acid. Although it is impossible to separate them, in any case, particles such as silicic acid are present on the surface, so that the performance improvement effect, particularly the oil absorption, etc. is remarkably improved. Furthermore, because the incinerated ash currently used as waste is reused, it is possible to reduce the environmental burden. Moreover, since there is little pre-processing with respect to incineration ash, since oil absorption is higher than the case where a light cal is used, it is specifically used when such a matter is required.
As content of said porous granule, it is desirable that it is the following range with respect to the whole each layer. The thermosensitive coloring layer contains 10 to 60% by weight, preferably 20 to 50% by weight, and the undercoat layer contains 20 to 80% by weight, preferably 30 to 70% by weight.

Next, as the leuco color-forming basic colorless dye used in the present invention, any conventional pressure-sensitive or heat-sensitive recording paper known in the field can be used and is not particularly limited. Preference is given to methane compounds, fluoran compounds, fluorene compounds, divinyl compounds and the like. Specific examples of typical ones are shown below. These dye precursors may be used alone or in combination of two or more.
<Triphenylmethane leuco dye>
3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (also known as crystal violet lactone)
3,3-bis (p-dimethylaminophenyl) phthalide (also known as malachite green lactone)
<Fluoran leuco dye>
3-diethylamino-6-methylfluorane 3-diethylamino-6-methyl-7-anilinofluorane 3-diethylamino-6-methyl-7- (o, p-dimethylanilino) fluorane 3-diethylamino-6-methyl -7-chlorofluorane 3-diethylamino-6-methyl-7- (m-trifluoromethylanilino) fluorane 3-diethylamino-6-methyl-7- (o-chloroanilino) fluorane 3-diethylamino-6-methyl- 7- (p-chloroanilino) fluorane 3-diethylamino-6-methyl-7- (o-fluoroanilino) fluorane 3-diethylamino-6-methyl-7- (m-methylanilino) fluorane 3-diethylamino-6-methyl- 7-n-octylanilinofluorane 3-diethylamino- 6-methyl-7-n-octylaminofluorane 3-diethylamino-6-methyl-7-benzylanilinofluorane 3-diethylamino-6-methyl-7-dibenzylanilinofluorane 3-diethylamino-6-chloro -7-methylfluorane 3-diethylamino-6-chloro-7-anilinofluorane 3-diethylamino-6-chloro-7-p-methylanilinofluorane 3-diethylamino-6-ethoxyethyl-7-anilino Fluorane 3-diethylamino-7-methylfluorane 3-diethylamino-7-chlorofluorane 3-diethylamino-7- (m-trifluoromethylanilino) fluorane 3-diethylamino-7- (o-chloroanilino) fluorane 3- Diethylamino-7- (p-chloroanilino) fluor Down 3-diethylamino-7-(o-fluoroanilino) fluoran 3-diethylamino - benzo [a] fluoran 3-diethylamino - benzo [c] fluoran

3-dibutylamino-6-methyl-fluorane 3-dibutylamino-6-methyl-7-anilinofluorane 3-dibutylamino-6-methyl-7- (o, p-dimethylanilino) fluorane 3-dibutylamino -6-methyl-7- (o-chloroanilino) fluorane 3-dibutylamino-6-methyl-7- (p-chloroanilino) fluorane 3-dibutylamino-6-methyl-7- (o-fluoroanilino) fluorane 3 -Dibutylamino-6-methyl-7- (m-trifluoromethylanilino) fluorane 3-dibutylamino-6-methyl-7-chlorofluorane 3-dibutylamino-6-ethoxyethyl-7-anilinofluorane 3-dibutylamino-6-chloro-7-anilinofluorane 3-dibutylamino-6-methyl-7- p-methylanilinofluorane 3-dibutylamino-7- (o-chloroanilino) fluorane 3-dibutylamino-7- (o-fluoroanilino) fluorane 3-di-n-pentylamino-6-methyl-7- Anilinofluorane 3-di-n-pentylamino-6-methyl-7- (p-chloroanilino) fluorane 3-di-n-pentylamino-7- (m-trifluoromethylanilino) fluorane 3-di- n-pentylamino-6-chloro-7-anilinofluorane 3-di-n-pentylamino-7- (p-chloroanilino) fluorane 3-pyrrolidino-6-methyl-7-anilinofluorane 3-piperidino- 6-Methyl-7-anilinofluorane 3- (N-methyl-N-propylamino) -6-methyl-7-anilinofluorane 3 (N-methyl-N-cyclohexylamino) -6-methyl-7-anilinofluorane 3- (N-ethyl-N-cyclohexylamino) -6-methyl-7-anilinofluorane 3- (N-ethyl) -N-xylamino) -6-methyl-7- (p-chloroanilino) fluorane 3- (N-ethyl-p-toludino) -6-methyl-7-anilinofluorane 3- (N-ethyl-N-isoamyl) Amino) -6-methyl-7-anilinofluorane 3- (N-ethyl-N-isoamylamino) -6-chloro-7-anilinofluorane 3- (N-ethyl-N-tetrahydrofurfurylamino) -6-Methyl-7-anilinofluorane 3- (N-ethyl-N-isobutylamino) -6-methyl-7-anilinofluorane 3- (N-ethyl-N-ethoxy) (Lopylamino) -6-methyl-7-anilinofluorane 3-cyclohexylamino-6-chlorofluorane 2- (4-oxahexyl) -3-dimethylamino-6-methyl-7-anilinofluorane 2- ( 4-oxahexyl) -3-diethylamino-6-methyl-7-anilinofluorane 2- (4-oxahexyl) -3-dipropylamino-6-methyl-7-anilinofluorane 2-methyl-6 -P- (p-dimethylaminophenyl) aminoanilinofluorane 2-methoxy-6-p- (p-dimethylaminophenyl) aminoanilinofluorane 2-chloro-3-methyl-6-p- (p- Phenylaminophenyl) aminoanilinofluorane 2-chloro-6-p- (p-dimethylaminophenyl) aminoanilinofluorane 2- Toro-6-p- (p-diethylaminophenyl) aminoanilinofluorane 2-amino-6-p- (p-diethylaminophenyl) aminoanilinofluorane 2-diethylamino-6-p- (p-diethylaminophenyl) Aminoanilinofluorane

2-phenyl-6-methyl-6-p- (p-phenylaminophenyl) aminoanilinofluorane 2-benzyl-6-p- (p-phenylaminophenyl) aminoanilinofluorane 2-hydroxy-6- p- (p-phenylaminophenyl) aminoanilinofluorane 3-methyl-6-p- (p-dimethylaminophenyl) aminoanilinofluorane 3-diethylamino-6-p- (p-diethylaminophenyl) aminoani Linofluorane 3-diethylamino-6-p- (p-dibutylaminophenyl) aminoanilinofluorane 2,4-dimethyl-6-[(4-dimethylamino) anilino] -fluorane <fluorene leuco dye>
3,6,6'-tris (dimethylamino) spiro [fluorene-9,3'-phthalide] 3,6,6'-tris (diethylamino) spiro [fluorene-9,3'-phthalide] <divinyl leuco dye >
3,3-bis- [2- (p-dimethylaminophenyl) -2- (p-methoxyphenyl) ethenyl] -4,5,6,7-tetrabromophthalide 3,3-bis- [2- ( p-dimethylaminophenyl) -2- (p-methoxyphenyl) ethenyl] -4,5,6,7-tetrachlorophthalide 3,3-bis- [1,1-bis (4-pyrrolidinophenyl) ethylene -2-yl] -4,5,6,7-tetrabromophthalide 3,3-bis- [1- (4-methoxyphenyl) -1- (4-pyrrolidinophenyl) ethylene-2-yl]- 4,5,6,7-tetrachlorophthalide <Others>
3- (4-Diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide 3- (4-diethylamino-2-ethoxyphenyl) -3- (1 -Octyl-2-methylindol-3-yl) -4-azaphthalide 3- (4-cyclohexylethylamino-2-methoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4- Azaphthalide 3,3-bis (1-ethyl-2-methylindol-3-yl) phthalide 3,6-bis (diethylamino) fluorane-γ- (3'-nitro) anilinolactam 3,6-bis (diethylamino) Fluorane-γ- (4′-nitro) anilinolactam 1,1-bis- [2 ′, 2 ′, 2 ″, 2 ″ -tetrakis- (p-dimethylaminopheny L) -ethenyl] -2,2-dinitrileethane 1,1-bis- [2 ′, 2 ′, 2 ″, 2 ″ -tetrakis- (p-dimethylaminophenyl) -ethenyl] -2-β -Naphthoylethane 1,1-bis- [2 ', 2', 2 ", 2" -tetrakis- (p-dimethylaminophenyl) -ethenyl] -2,2-diacetylethane bis- [2,2,2 ', 2'-tetrakis- (p-dimethylaminophenyl) -ethenyl] -methylmalonic acid dimethyl ester

  In the present invention, a conventionally known developer can be used as long as the desired effect on the above-described problems is not impaired. Such developers include activated clay, attapulgite, bisphenol A, 4-hydroxybenzoic acid esters, 4-hydroxyphthalic acid diesters, phthalic acid monoesters, bis- (hydroxyphenyl) sulfides, 4-hydroxy Phenylaryl sulfones, 4-hydroxyphenyl aryl sulfonates, 1,3-di [2- (hydroxyphenyl) -2-propyl] -benzenes, 4-hydroxybenzoyloxybenzoate, bisphenol sulfones, An aminobenzenesulfonamide derivative described in 8-59603, a diphenylsulfone bridged compound described in International Publication WO97 / 16420, a phenolic compound described in International Publication WO02 / 081229 or JP2002-301873, A phenyl novolak type condensation composition described in International Publication WO02 / 098774 or WO03 / 029017, a urea urethane compound described in International Publication WO00 / 14058 or JP2000-143611, N, N′-di-m- Examples thereof include thiourea compounds such as chlorophenylthiourea, and these can be used alone or in admixture of two or more. Among these, 4,4′-dihydroxydiphenylsulfone (bisphenol S) and 4-hydroxy-4′-isopropoxydiphenylsulfone are most preferable in terms of color tone and storage stability.

  In this invention, a conventionally well-known sensitizer can be used in the range which does not inhibit the desired effect with respect to the said subject. Such sensitizers include saturated fatty acid monoamide, ethylene bis fatty acid amide, montanic acid wax, polyethylene wax, 1,2-di- (3-methylphenoxy) ethane, p-benzylbiphenyl, 4-biphenyl-p-tolyl ether. M-terphenyl, 1,2-diphenoxyethane, 4,4′-ethylenedioxy-bis-benzoic acid dibenzyl ester, dibenzoyloxymethane, 1,2-di (3-methylphenoxy) ethylene, 1 , 2-diphenoxyethylene, bis [2- (4-methoxy-phenoxy) ethyl] ether, methyl p-nitrobenzoate, benzyl p-benzyloxybenzoate, di-p-tolyl carbonate, phenyl-α-naphthyl carbonate 1,4-diethoxynaphthalene, 1-hydroxy-2-naphthoic acid Phenyl ester, 4- (m-methylphenoxymethyl) biphenyl, dimethyl phthalate, naphthylbenzyl ether, oxalic acid-di- (p-methylbenzyl), oxalic acid-di- (p-chlorobenzyl), 4-acetylbiphenyl, etc. Although it can illustrate, it is not restrict | limited in particular to these.

As the binder used in the present invention, fully saponified polyvinyl alcohol having a polymerization degree of 200 to 1900, partially saponified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, amide-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, butyral-modified polyvinyl alcohol, and others Modified polyvinyl alcohol, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, styrene-maleic anhydride copolymer, styrene-butadiene copolymer and cellulose derivatives such as ethyl cellulose, acetyl cellulose, polyvinyl chloride, polyvinyl acetate, poly Acrylamide, polyacrylic ester, polyvinyl butyllar, polystyrose and their copolymers, polyamide resin, silico Resins, petroleum resins, terpene resins, ketone resins, and the Khumalo resin. These polymer substances are used by dissolving them in solvents such as water, alcohol, ketones, esters, hydrocarbons, etc., and are used in the state of being emulsified or pasted in water or other media to achieve the required quality. It can also be used in combination.
Further, in the present invention, 4,4′-butylidene (6-tert-butyl-3-methylphenol) is used as an image stabilizer exhibiting the oil resistance effect of a recorded image within a range that does not inhibit the desired effect on the above problems. ), 2,2'-di-t-butyl-5,5'-dimethyl-4,4'-sulfonyldiphenol, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) Butane, 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane and the like can also be added.

In the present invention, in addition to the above porous particles, other inorganic or organic substances such as silica, calcium carbonate, kaolin, calcined kaolin, diatomaceous earth, talc, titanium oxide, aluminum hydroxide, etc., as long as the effect is not impaired. A filler may be used in combination.
In addition, lubricants such as waxes, benzophenone and triazole ultraviolet absorbers, water resistance agents such as glyoxal, dispersants, antifoaming agents, antioxidants, fluorescent dyes, and the like can be used.
The amount of developer and dye used in the heat-sensitive recording material of the present invention, and the type and amount of other various components are determined according to the required performance and recording suitability, and are not particularly limited. 0.1 to 2 parts of basic colorless dye and 0.5 to 4 parts of filler are used with respect to parts, and the binder is suitably 5 to 25% of the total solid content.
The desired thermosensitive recording sheet can be obtained by coating the coating liquid having the above composition on an arbitrary support such as paper, recycled paper, synthetic paper, film, plastic film, foamed plastic film, and non-woven fabric. Moreover, you may use the composite sheet which combined these as a support body.

  The aforementioned organic developer, basic colorless dye, and materials to be added as necessary are finely pulverized to a particle size of several microns or less with a pulverizer such as a ball mill, an attritor or a sand grinder or an appropriate emulsifier. Depending on the purpose, various additive materials are added to obtain a coating solution. The application means is not particularly limited, and can be applied according to well-known conventional techniques. For example, an off-machine coating having various coaters such as an air knife coater, a rod blade coater, a bill blade coater, a roll coater, and a curtain coater. A machine or an on-machine coating machine is appropriately selected and used.

The physical properties of the porous granules obtained in the production examples described below were measured by the following methods.
Oil absorption: According to JIS K5101.
Particle size distribution (laser diffraction / scattering method): A sample slurry of porous powder is dropped and mixed in pure water to which 0.2% by weight of sodium hexametaphosphate dispersant is added to form a uniform dispersion. Equipment used: Measured using a Malvern Mastersizer S type).

[Production Example 1]
In a reaction vessel (2 L), commercially available No. 3 sodium silicate (SiO ₂ : 20.0%, Na ₂ O: 9.5%) was diluted with water to obtain a 6.9% by weight diluted sodium silicate solution as SiO ₂ 2L was prepared. 30 parts by weight of coal incineration ash (A) is mixed with 100 parts by weight of silicic acid, and the sodium silicate suspension is heated to 85 ° C., and then 98% concentrated sulfuric acid in an amount corresponding to 40% of the neutralization equivalent. Was added at a dropping rate of 2 g / min with sufficient vigorous stirring so that no coarse gel was generated. Thereafter, the mixture was aged for 2 hours with constant stirring at a constant temperature. Next, with the slurry temperature kept at a constant 85 ° C., sulfuric acid having the same concentration as in the first step was added to 80% of the neutralization equivalent under the same conditions as in the first step, and aged for 32 minutes with stirring. Subsequently, sulfuric acid having the same concentration was similarly added to the slurry after aging at an addition rate of 0.8 g / min to adjust the slurry pH to 6. The slurry after completion of the third step was filtered, washed with water, repulped into pure water, and the hydrated silicate slurry was recovered. The obtained slurry was filtered, dissolved in ethanol to a solid content of 10%, filtered again, dried at 105 ° C., and the oil absorption and whiteness of the granulated product were measured. The oil absorption was 296 ml / 100 g, and the ISO whiteness was 66.5%.

[Production Example 2]
A porous granule was prepared in the same manner as in Production Example 1 except that sodium silicate was neutralized with a sulfuric acid band. The oil absorption was 210 ml / 100 g, and the ISO whiteness was 74.7%.
[Production Example 3]
Porous granules were prepared in the same manner as in Production Example 2 except that sludge incineration ash was used instead of coal incineration ash (A). The oil absorption was 210 ml / 100 g, and the ISO whiteness was 85.7%.

[Comparative Production Example 1]
The coal incineration ash (A) used in Production Example 1 was diluted with pure water to 10%, filtered, dissolved in ethanol to a solid content of 10%, filtered again, and dried at 105 ° C. The oil absorption and whiteness of the granulated product were measured. The oil absorption was 26 ml / 100 g, and the ISO whiteness was 45.7%.
[Comparative Production Example 2]
The sludge incineration ash (A) used in Production Example 3 was diluted to 10% with pure water, filtered, dissolved in ethanol to a solid content of 10%, filtered again, and dried at 105 ° C. The oil absorption and whiteness of the granulated product were measured. The oil absorption was 62 ml / 100 g, and the ISO whiteness was 79.1%.

[Comparative Production Example 3]
Porous granules obtained without adding coal incineration ash and coal incineration ash (A) of Comparative Production Example 2 to 30 parts by weight of coal incineration ash (A) with respect to 100 parts by weight of porous granules After mixing, the slurry was diluted to 10% with pure water, filtered, dissolved in ethanol to a solid content of 10% and filtered again, and dried at 105 ° C. to obtain the oil absorption of the granulated product, white The degree was measured. Oil absorption 628ml / 100g, ISO whiteness was 60%.

Hereinafter, the present invention will be described by way of examples. In the description, parts indicate parts by weight.
[Example 1]
<Under layer paint>
Porous granules of production example 1 (solid content 20%) 250.0 parts 10% polyvinyl alcohol aqueous solution 50.0 parts An undercoating composition having the above composition was prepared.
<Thermal layer coating>
For each material of the dye and developer, a dispersion having the following composition was prepared in advance, and wet grinding was performed with a sand grinder until the average particle size became 0.5 microns.
<Developer dispersion>
4-hydroxy-4'-isopropoxydiphenylsulfone
6.0 parts 10% aqueous polyvinyl alcohol solution 18.8 parts Water 11.2 parts <Dye dispersion>
3-Di-n-butylamino-6-methyl-7-anilinofluorane
(ODB2) 3.0 parts 10% polyvinyl alcohol aqueous solution 6.9 parts water 3.9 parts <sensitizer dispersion>
Diphenylsulfone 6.0 parts 10% aqueous polyvinyl alcohol solution 18.8 parts Water 11.2 parts

The following compositions were mixed to obtain a thermosensitive coloring layer coating solution.
Developer dispersion 36.0 parts Dye dispersion (ODB2) 13.8 parts Sensitizer dispersion 36.0 parts Kaolin clay 50% dispersion 26.0 parts Zinc stearate 30% dispersion 6.7 parts tsubo The undercoat is applied to the surface of a base paper having an amount of 50 g / m ² and dried, and then the heat-sensitive layer is applied and dried to 6.0 g / m ^2, and the Beck smoothness is 200 to 600 seconds using a super calendar. The heat-sensitive recording material was obtained.

[Example 2]
The porous particle of Production Example 1 of the under layer was changed to 100 parts of kaolin clay (solid content 50%), and the kaolin clay of the heat sensitive layer was changed to 65 parts of the porous particle of Production Example 1 (solid content 20%). A heat-sensitive recording material was obtained in the same manner as in Example 1 except that.
[Example 3]
A heat-sensitive recording material was obtained in the same manner as in Example 1 except that the porous particles in Production Example 1 were changed to the porous particles in Production Example 2 (solid content 20%).
[Example 4]
A heat-sensitive recording material was obtained in the same manner as in Example 2 except that the porous particles of Production Example 1 were changed to the porous particles of Production Example 3 (solid content 20%).

[Comparative Example 1]
A heat-sensitive recording material was obtained in the same manner as in Example 1 except that the porous particles in Production Example 1 were changed to Comparative Production Example 1 (adjusted to a solid content concentration of 20%).
[Comparative Example 2]
A thermosensitive recording material was obtained in the same manner as in Example 2 except that the porous particles in Production Example 1 were changed to Comparative Production Example 1 (adjusted to a solid content concentration of 20%).

[Comparative Example 3]
A heat-sensitive recording material was obtained in the same manner as in Example 1 except that the porous particles in Production Example 1 were changed to Comparative Production Example 2 (adjusted to 20% solid content).
[Comparative Example 4]
A heat-sensitive recording material was obtained in the same manner as in Example 2 except that the porous particles in Production Example 1 were changed to Comparative Production Example 3 (adjusted to a solid content of 20%).

[Reference Example 1]
Instead of the porous particles in Production Example 1, commercially available silica (trade name: P-78A, manufactured by Mizusawa Chemical Co., Ltd., particle diameter 3.3 μm, oil absorption 250 ml / 100 g, adjusted to 20% solid content concentration) is used. A heat-sensitive recording material was obtained in the same manner as in Example 1 except that.
[Reference Example 2]
Instead of the porous particles in Production Example 1, commercially available silica (trade name: P-78A, manufactured by Mizusawa Chemical Co., Ltd., particle diameter 3.3 μm, oil absorption 250 ml / 100 g, adjusted to 20% solid content concentration) is used. A heat-sensitive recording material was obtained in the same manner as in Example 2 except that.

[Thermal recording aptitude evaluation]
The performance of the thermosensitive layers of the thermosensitive recording materials obtained in the above Examples and Comparative Examples was evaluated by the following method.
(Color development sensitivity)
Using TH-PMD manufactured by Okura Electric Co., Ltd., printing was performed on the created thermal recording medium with an applied energy of 0.34 mJ / dot. The image density after printing was measured with a Macbeth densitometer (using an amber filter).
(Head Cus)
Printing was performed using a label printer-less pre-T8 manufactured by SATO, and the degree of head residue adhesion was visually confirmed.
○: Almost no head residue △: Some head residue but no missing print ×: Many head residue and missing print (stick)
Printing was performed at 0 ° C. using a Canon Handy Terminal HT180, and the stick was confirmed.
○: Almost no white spots in the black solid print area △: Some white areas in the black solid print area are observed ×: White areas in the black solid print area are considerably seen

Claims (1)

A heat-sensitive recording medium provided with a heat-sensitive color-developing layer containing a colorless or light-colored basic colorless dye and an organic developer as main components on a support, and incineration ash discharged from a combustion facility in the heat-sensitive recording medium A heat-sensitive recording material comprising porous particles in which particles of a substance selected from the group consisting of silicic acid, silicates, and mixtures thereof are included.