JPS59114097A - Color developer for pressure-sensitive recording paper - Google Patents

Abstract

PURPOSE:To obtain a pressure-sensitive recording paper excellent in color-forming property and weather resistance, by a method wherein a material obtained by adding a propane derivative phenol to a phenolic resin is used as a color developer in a pressure-sensitive recording paper. CONSTITUTION:A propane derivative phenol such as 4,4'-dihydroxydiphenyl-2,2'- propane of formula II is used in a quantity of 5-300pts.wt., preferably 10- 200pts.wt. per 100pts.wt. of a phenolic resin obtained by the reaction of a compound of formula I (wherein R is hydrogen, an alkyl group, a phenyl group, an aralkyl group, a sulfonic acid residue or the like) with an aldehyde. The propane derivative may be of one kind, but it is most preferable to use three kinds of propane derivatives in an appropriate ratio. The two components are mixed with each other in a powder form or in a melted form under heating, thereby obtaining a color developer, from which a dispersed liquid of the color developer for a pressure-sensitive recording paper is prepared by an ordinary method.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel color developer for pressure-sensitive recording paper containing a phenolic resin and a procene derivative phenol as an essential component. The present invention provides a novel color developer for obtaining pressure recording paper.

Pressure-sensitive recording generally involves the reaction between a colorless electron-donating organic compound (hereinafter referred to as a color former) and an electron-accepting color developing substance (hereinafter referred to as a color developer) that can react to form a colored product. This is what was used.

Conventionally, inorganic clays such as acid clay, zeolite, bentonite, and kaolin, and phenol-aldehyde condensates (phenol resins) are known as color developers. Phenolic resin, especially Harati! Functional phenol/formaldehyde condensates have superior performance in forming moisture-resistant colored images compared to inorganic clays, and have already been put to practical use as color developers and have undergone many improvements.

That is, Special Publication No. 1972-20144, Special Publication No. 1973
has been done. However, although these color developers have the ability to form a moisture-resistant color image, the color development rate is insufficient, and the color may turn yellow or the color image may fade when exposed to sunlight. It has the disadvantage of

As a method for improving color development and weather resistance, Japanese Patent Publication No. 47-20971 describes a method of adding a divalent metal salt such as zinc chloride to a no+substituted bifunctional phenol/aldehyde condensate. No. 48-25744 describes a zinc salt of a phenylphenol/formaldehyde condensate, but it has not improved both color development and weather resistance, and there is a strong desire for improvement in color developers.

As a result of research conducted in view of the above circumstances, the inventors have discovered that a color developer having extremely excellent color development and weather resistance can be obtained by adding gulono-4 derived phenyls to a phenol resin.

That is, the present invention provides a combination of a compound represented by the following general formula (1) and H (R: hydrogen, alkyl group, phenyl group, aralkyl group, sulfonic acid group, carboxylic acid group, carboxylic acid ester group, halogen) aldehyde. Phenol resin (A) obtained by reaction
The present invention relates to a novel color developer for pressure-sensitive recording paper, which contains as an essential component one or more propane derivatives (E) represented by the following general formula CI+) and has extremely excellent color development and weather resistance.

The compounds represented by the above general formula [1] constituting the phenolic resin (A) used in the present invention are p-cresol, p-ethylphenol, p-7' lobylphenol,
p-Secondary-butylphenol, p-tert-butylphenol, p-amylphenol, p-cyclohexylphenol, p-hebutylphenol, p-
Tertiary-octylphenol, p-dodecylphenol, p-nonylphenol, p-phenylphenol, p-cumylphenol, p-10ruphenol, p-
These are 74'-substituted phenols and phenols such as bromophenol, p-phenolsulfonic acid, p-phenolcarganic acid, and p-phenolcaldic acid ester, and one or more of these are used. These compounds are preferably p-phenylphenol, p-tertiary
Butylphenol and p-tert-octylphenol. Preferably p-phenylphenol 5
0 to 95 weight iL%,! -1) -Tertiary-butylphenol and/or p-tertiary-octylphenol is used in an amount of 5 to 50% by weight.

The aldehydes used in the present invention include formaldehyde (formalin, paraformaldehyde, formaldehyde gas), acetaldehyde, butyraldehyde, and the like, with formaldehyde being common.

The phenol resin (A) is a novolac type phenol resin obtained by reacting one or more of the para-substituted phenols and phenols with the aldehyde in the presence of a catalyst, and has a melting point of 50 to 170°C. . The phenol resin (A) may be a co-condensed resin of two or more of the above-mentioned phenols, or a mixture of one or more resins of different phenols obtained from one of the above-mentioned phenols.

The propane derivative phenols (B) represented by the above general formula [■] used in the present invention are 4,4'-dihydroxydiphenyl-2,2'-propane (a), 2
．． 4'-dihydroxydiphenyl-2,2'-propane (b) and 2,2'-dihydroxydiphenyl-2,2'-propane (C), one or more of these is used.

In the present invention, the blending ratio of the phenolic resin (A) and the pro-matri derivative phenols CB) may be any value, but preferably 5 to 5 parts by weight of (B) to 100 parts by weight of (A).
It contains 300 parts by weight, more preferably 10 to 200 parts by weight. If the amount of (B) present is small, the weather resistance of pressure-sensitive recording paper using this as a color developer cannot be obtained sufficiently, but it is preferable to have 21 or more present.

The method for producing the color developer of the present invention includes phenolic resin (A
) and one or more of the propane derivative phenols (B)
Either method can be used, such as a method of mixing two or more seeds in powder form, or a method of heating and melting and mixing the two. This is usually
A wet pulverizer such as an attritor or a sand grinder is used to wet pulverize in water in the presence of a surfactant, a dispersant, etc. as necessary, to form a dispersion liquid, and a color developer dispersion for pressure-sensitive recording paper is prepared. The method of mixing the phenol m fat (A) and the propane derivative phenol (B) in the above-mentioned wet grinder is used. It may also be used by dispersing or dissolving it in a solvent other than wood cutting, or by mixing the two at the time of dispersion or dissolution.

The above color developer dispersion may contain adhesives, inorganic or organic pigments,
A coating liquid is prepared by mixing with a pigment dispersant, a fluorescent whitening agent, an antifoaming agent, a viscosity modifier, an anti-dusting agent, a lubricant, a water resistant agent, etc. This coating liquid is applied to paper or sheets using a roll coater or the like, and dried to obtain a recording paper or recording sheet having the color developer layer of the present invention on its surface.

The solvent used in the above-mentioned dispersion or solution is one of water, alcohols, esters, ketones, aromatics, or high-boiling solvents, or a mixture thereof. For example, 1) nonionic surfactants such as partial esters of polyhydric alcohols such as polyethylene glycol type (ester type, ether type or alkylphenol type) sorbitan ester; 2) formalin condensate of naphthalene-sulfonic acid; Synthetic and natural anionic surfactants such as oligostyrene sulfonates, alkali golden brown salts of maleic acid-cocondensates, and lignin sulfonates; 3) polyphosphoric acids such as sodium metaphosphate and sodium birophosphate; Inorganic ionic surfactants such as salts may be selected and used. A water-soluble polymer compound may also be used as a purulent colloid.

Examples of adhesives added to the coating solution containing the color developer of the present invention include casein, starch, gum arabic, butadiene latex, hydroxyethyl cellulose, vinyl acetate polymer, melamine resin, sodium polyacrylate, and polyester resin. synthetic resins, etc. Furthermore, organic substances such as kaolin, bentonite, melamine resin, original resin, polyacrylic acid resin, polyester resin, phenol resin, resin, epoxy resin, petroleum resin, and xylene resin are used as fillers. As dispersants for these fillers, polyphosphates such as sodium metaphosphate and sodium hexametaphosphate, sodium polyacrylate, and the like are used.

By using the color developer of the present invention, a pressure-sensitive recording paper with extremely excellent color development and weather resistance can be obtained. In this way, pheno-/' 411
The reason why a color developer containing Zolone/4' derivative phenols (B) as an essential component in fat (A) improves color development and weather resistance at the same time, especially when using Zolone/4' derivative phenols (B), which do not exhibit effects when each component is used alone. It is still unclear why the presence of three specific substances in the 4' derivative phenol (B) in the phenol resin (A) significantly improves color development and weather resistance at the same time, but in the case of improvement in color development, Probably propane derivative phenols (B) are phenolic resins (A).
) within the composition range of the present invention, the phenolic resin has coloring ability, and the phenolic resin also becomes easily soluble in the solvent containing the coloring agent, greatly improving the coloring speed and density. It will be done. In addition, in the case of improving weather resistance, propane derivative phenols have a stable molecular structure, so when mixed with a phenol resin (A) that has a chemical structure that easily resonates with sunlight energy, when the phenol resin body) resonates, It is thought that collisions of molecules occur and have the effect of inhibiting resonance. This is considered to be the reason why weather resistance such as yellowing resistance and fading resistance is also significantly improved if the composition is within the range of the composition of the present invention.

Examples of the present invention will be described below, but the present invention is not limited to these examples. It is described here [
Part J and [%J] all indicate "parts by weight" and "% by weight" unless otherwise specified.

Synthesis Example 1 500 parts of p-phenylphenol, 37% formalin 1
24 parts of benzene, 100 parts of benzene, and 5 parts of oxalic acid were placed in a reaction vessel and refluxed at 84°C for 10 hours. Thereafter, the water was dehydrated and the solvent removed under vacuum, and when the internal temperature was raised to 180° C., the pot was taken out of the pot. Solid condensate (X) with yellowish brown color and melting point of 82°C 51
Got 2 copies.

Synthesis Example 2 350 parts of p-tert-octylphenol, 150 parts of phenol, 184 parts of 37-thiformalin, 5 parts of 20-thiodium hydroxide aqueous solution, and 300 parts of water were placed in a reaction vessel and refluxed at 97°C for 3 hours. Thereafter, the pH was adjusted to 5 with concentrated sulfuric acid. Next, 2 parts of concentrated hydrochloric acid was added to this, and the mixture was refluxed at 97°C for 1 hour. Thereafter, it was dehydrated under vacuum, and when the internal temperature was raised to 180°C, it was taken out of the pot. 510 parts of a solid condensate (Y) having a yellowish brown color and a melting point of 84° C. was obtained.

Synthesis Example 3 350 parts of p-tert-octylphenol, 150 parts of phenol, 184 parts of 37% formalin, 5 parts of a 20% aqueous sodium hydroxide solution and 300 parts of water were placed in a reaction vessel and refluxed at 97°C for 3 hours. Then adjust the pH with concentrated sulfuric acid.
was adjusted to 6. Next, add 2 parts of concentrated hydrochloric acid to this and
The mixture was refluxed at ℃ for 1 hour. Thereafter, it was dehydrated under vacuum, and when the internal temperature was raised to 180°C, the pressure was returned to normal pressure. To this, 4,4'-dihydroxydiphenyl-2,
1 part of 2'-Proburn was added and melted and mixed. After the contents became uniform, the contents were taken out of the pot to obtain 675 parts of a brown solid condensate (Z) with a melting point of 78°C.

Example 1 The above solid condensate (X) was milled with an average particle size of 100 in a hammer mill.
Finely ground to μ. 100 parts of this fine powder and Sekibu fine powder of 4,4'-dihydroxydiphenyl-2,2'-propane having the same average particle size were placed in a ■-type blender and triblended for 1 hour. I took it out. In this way, a uniform fine powder color developer component (1) was obtained. 40 parts of this color developer component (1), 1 part of anionic surfactant ([Olotane J 731 + manufactured by Rohm & Haas),
0.1 part of PVA powder was charged into an attritor together with 58.9 parts of water and wet-pulverized for 8 hours to obtain a dispersion having a particle size of 5 microns or less.

This dispersion liquid was charged into an experimental mixer according to the formulation shown in Table 1, and mixed uniformly for 1 hour to prepare a coating liquid for sea bream.

Is the coating amount of this coating liquid 5 f/rr? (dry weight) to obtain a recording sheet having a color developer layer on the surface.

Example 2 100 parts of a fine powder of the solid condensate (X) of Example 1 and a fine powder of 4,4'-dino-1-hydrooxydiphenyl-2,2-propane having a similar average particle size 22. Part 5, 2
．． 5 parts of 4'-dihydroxydiphenyl-2,2'-glono-4, 2,2'-dihydroxydiphenyl-
2.5 parts of 2,2'-zoronomone was placed in a V-type blender, triblended for 1 hour, and then taken out. In this way, a uniform color developer component (■) was obtained. This color developer component (If
) 40 parts of an anionic surfactant (
1 part of "Orotan" 731), 0.1 part of PVA powder, 5 parts of water
The mixture was charged into an attritor together with 8.9 parts, and wet-pulverized for 8 hours to obtain a dispersion having a particle size of 5 microns or less.

Thereafter, a recording sheet having a color developer layer on the surface was obtained in the same manner as in Example 1.

Example 3 The above solid condensate (Z) was milled with an average particle size of 100 using a hammer mill.
It was finely pulverized to μ to obtain a color developer component Q [[). 40 parts of this color developer component (In), 1 part of anionic surfactant ("Olotane" 731) and 0.1 part of PVA powder in the same manner as in Example 1.
1 part was charged into an attritor together with 58.9 parts of water and wet-pulverized for 8 hours to obtain a dispersion having a solid particle size of 5 microns or less. Thereafter, a recording sheet having a color developer layer on the surface was obtained in the same manner as in Example 1.

Example 4 16 parts of the solid condensate (X) fine powder of Example 1 was mixed with an anionic surfactant ("Olotane" 731) in the same manner as in Example 1.
1 part of PVA powder and 0.1 part of PVA powder were placed in an attriter together with 58.9 parts of water and wet-pulverized for 3 hours. Here, 20.4 parts of 4,4'-dihydroxydiphenyl-2,2'-fronobutsu having the same particle size as the solid condensate (X), 2
．． After sequentially adding 1.2 parts of 4'-zohydroxydiphenyl-2,2'-propane and 2.4 parts of 2,2'-dihydroxydiphenyl-2,2'-propane, wet milling was further carried out. It continued for 5 hours. In this way, a dispersion containing a color developer component having a particle size of 5 μm or less was obtained. Thereafter, a recording sheet having a color developer layer on the surface was obtained in the same manner as in Example 1.

Comparative Example 1 Solid condensate (X) was milled with an average particle size of 100 in a hammer mill.
The color developer component (powder) was obtained by finely pulverizing the color developer component (
V) In the same manner as in Example 1, 1 part of an anionic surfactant ("Orothane" 731) and 0.4 g of PVA powder were charged into an attritor along with 58.9 parts of water, and wet-pulverized for 8 hours to form a solid. A dispersion liquid having a particle size of 5 μm or less was obtained. Thereafter, a recording sheet having a color developer layer on the surface was obtained in the same manner as in Example 1.

Comparative Example 2 The solid condensate (Y) was finely pulverized with a hammer mill to an average particle size of lOOμ to obtain a color developer component 0). This color developer component (V
Similarly to Example 1, 40 parts of D was added to 1 anionic surfactant (r
1 part of PVA powder and 0.1 part of PVA powder were charged into an attritor together with 58.9 parts of water and wet-pulverized for 8 hours to obtain a dispersion having a solid particle size of 5 μm or less. Thereafter, a recording sheet having a color developer layer on the surface was obtained in the same manner as in Example 1.

Comparative Example 3 4,4'-dihydroxydiphenyl-2,2'-zolopane was used as a color developer component with an average particle size of 10 in a hammer mill.
A recording sheet having a color developer layer on the surface was obtained in the same manner as in Comparative Example 2 except that the finely powdered color developer component (a) pulverized to 0 μm was used.

Comparative Example 4 22.5 parts of 4.41-dihydroxydiphenyl-2,2'-zolopane, 5 parts of 2.4'-dihydroxydiphenyl-2,2'-propane, 2,2'-dihydroxy After pulverizing 2.5 m of diphenyl-2,2'-zolopane to an average particle size of 100 μm using a hammer mill, the mixture was placed in a V-type blender, triblended for 1 hour, and then taken out. A recording sheet having a color developer layer on the surface was obtained in the same manner as in Comparative Example 2 except that this finely powdered color developer component (4) was used as the color developer component.

Performance test method a) Color development: A color development sheet containing crystal violet lactone was layered on the above-mentioned recording sheet, and color development was performed using a direct-acting typewriter. The speed of color development is measured after 60 seconds, and the degree of color development is measured after 60 minutes using a reflective color difference meter (Nippon Denshoku Rifu).
It was measured with The results are reflectance (indicated by a hook; the lower the value, the higher the color density.

b) Brown resistance: The recording sheet colored in step a) above was irradiated with sunlight for 3 hours. In order of decreasing degree of brownness ◎,
It was set as ○, Δ, and ×.

C) Yellowing resistance: The uncolored recording sheet was exposed to sunlight for 3 hours. The grades were rated ◎, ○, Δ, and × in order of decreasing degree of yellowing.

The results are shown in Table 2. As will be seen from now on, the recording sheet having the color developer layer according to the present invention on its surface can reliably exhibit the effects of the essential components.

Table 1

Claims (6)

[Claims] (1) The following = phenolic resin obtained by the reaction of the compound represented by the general formula (1) and aldehydes (A) H (R: hydrogen, alkyl group, phenyl group, aralkyl group,
Sulfonic acid group, carboxylic acid group, caldenic acid ester group,
A novel pressure-sensitive recording paper color developer containing as an essential component one or more of the following general formula [11]: (2) The pressure-sensitive recording paper color developer according to claim 1, which contains 10 to 200 parts by weight of propane derivative phenol (B) per 100 parts by weight of phenol resin (A). (3) 70 Lonogun derivative phenols (B) are 4,4
The pressure-sensitive recording paper color developer according to claim 1 or 2, which is '-dihydroxydiphenyl-2,2'-propane. (4) f-2,4' derivative phenols CB)
-dihydroxydiphenyl-2,2'-pronobase.The pressure-sensitive recording paper color developer according to claim 1 or 2, which is -dihydroxydiphenyl-2,2'-pronobase. (5) Gulonone derivative phenols CB) is 2
, 2'-dihydroxydiphenyl-2,2'-propane. (6) f-lopane derivative phenols) is 4,4'
-dihydroxydiphenyl-2,2'-f/4'
(a), 2,4'-') hydroxydiphenyl-2,4'-sohydroxydiphenyl-2,2'-
The pressure-sensitive recording paper color developer according to claim 1 or 2, which is a mixture of pronocentine (b) and 2,2'-zohydroxydiphenyl-2,2'-propane (0). . The pressure-sensitive recording paper color developer described in item 6.