JPS63118288A - Solvent for pressure sensitive transfer paper and production thereof - Google Patents

Abstract

PURPOSE:To enhance stability to oxidation, by using a mixture obtained by subjecting a mixture of a dimer of a styrene and a styrene-alkylbenzene adduct to hydrogenation of only aliphatic unsaturated double bonds. CONSTITUTION:Compounds of formulas I and II (wherein each of R1, R2, R3 and R4 is -H or an up to 3C alkyl) are brought into reaction with each other by using a cation exchanger as a catalyst to obtain a mixture of a dimer of a styrene and a styrene-alkylbenzene adduct, and aliphatic unsaturated double bonds in the reaction products are hydrogenated, followed by distillation to obtain a mixture of compounds of formulas III, IV and V. The starting compound of formula I may be an alkylbenzene, e.g., toluene, ethylbenzene, o-xylene or isopropylbenzene. The starting compound of formula II may be a styrene, e.g., styrene, alpha-methylstyrene or p-methylstyrene. As a result, the stability to oxidation and dye-dissolving properties can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a solvent for pressure-sensitive copying paper, and more particularly to a solvent for dyes used in microencapsulating dyes for pressure-sensitive copying paper, and a method for producing the same. It is.

(Prior Art) Various solvents have been proposed as dye solvents for pressure-sensitive copying paper, but the various properties and conditions required for these solvents
For example, 1) it must be a high boiling point oil, 2) it must be odorless,
3) Colorless, 4) High dye solubility, 5
) low viscosity, 6) poorly soluble in water, 7)
It has been difficult to obtain a product that satisfies all of the following requirements: non-toxicity, 8) low cost, etc.

In the past, chlorinated biphenyls (hereinafter referred to as rPCBJ) were used as a solvent for pressure-sensitive copying paper, but PCBs were found to be toxic and have extremely low biodegradability.
It became a major social problem.

As a result, strict regulations were put in place for its use, leading to its suspension. For this reason, various alternative oils for PCB have been studied, and various oils such as alkyldiphenyl, diarylalkanes, and alkylnaphthalenes have been proposed, but all of these have the properties required as a solvent, such as odorlessness, solubility of dyes, The low temperature fluidity etc. were not fully satisfied.

Therefore, current techniques for further improving these properties include 1) a method of preparing a dimer mixture using styrene or methylstyrene as a raw material, as described in JP-A-55-63292, and using this as a solvent; Kaisho 55-272
3) A method using 1,3-diphenylbutadiene obtained by hydrogenating an unsaturated dimer of styrene as a solvent, as described in JP-A-55-236 and JP-A-53-53-
A method using an oil such as phenylxylylethane described in Japanese Patent No. 43332 and the like is known.

(Problems to be solved by the invention) However, even in these conventional techniques 1) to 3),
It has been impossible to fully satisfy all of the above-mentioned properties required of a solvent.

That is, in a method in which a mixture of dimers is prepared from styrene or methylstyrene as a raw material and this is used as a solvent, the solubility of the dye is improved by the styrene dimer, especially the cyclic dimer. However, there is a problem that the color development speed becomes slow. In addition, unsaturated dimers of styrenes are
It is unsuitable as a solvent for dyes because it not only gives off an unpleasant odor due to the unsaturated double bonds in the molecule, but also changes over time, causing deterioration of hue and increase in viscosity.

In addition, it is claimed that the method of using 1,3-diphenylbutadiene obtained by hydrogenating an unsaturated dimer of styrene as a solvent has good dye solubility and color development speed. However, it is difficult to highly selectively produce only unsaturated dimers in -i, so various separations, purifications, etc. are performed to obtain unsaturated dimers, which are then hydrogenated. This is not a practical method because it would be expensive.

Furthermore, in the method of using oil such as phenylxylylethane, although such oil has almost satisfactory properties as a solvent for pressure-sensitive copying paper, it has the disadvantage that it does not have sufficient solubility for dyes. be.

As described above, up to now, it has not been possible to obtain a high boiling point oil that satisfies all of the various requirements required as a solvent for pressure-sensitive copying.

Therefore, the object of the present invention is to solve the conventional problems such as unpleasant odor and poor oxidation stability due to the presence of unsaturated styrene dimer, and low dye solubility, and to develop a dye solvent for pressure-sensitive copying paper. The objective is to provide high boiling point oil at a low price that satisfies various requirements.

(Means for Solving the Problems) That is, the present invention solves the following general formulas (R11R2+ R3 and R3 in formulas (1) to (III))
The present invention relates to a solvent for pressure-sensitive copying paper comprising each compound represented by -H or an alkyl group having 3 or less carbon atoms, respectively.

Further, in the present invention, in producing the pressure-sensitive copying paper solvent, the following general formula, (formula (IV
) and R1+ RZ, R3 and R4 in (V) are the same as those described above) to form a mixture of a styrene dimer and a styrene-alkylbenzene adduct. and then hydrogenating the aliphatic unsaturated double bonds in these reaction products, followed by distillation to obtain a mixture of each compound represented by the general formulas (1) to (I[[). The present invention relates to a method for producing a solvent for pressure-sensitive copying paper.

As the raw material compound represented by the general formula (IV), for example, alkylbenzenes such as toluene, ethylbenzene, 0-xylene, m-xylene, various trimethylbenzenes, and isopropylbenzenes can be used. These alkylbenzene raw materials can be used as a single component or as a mixture.

In addition, as the raw material compound represented by the general formula (V),
For example, styrenes such as styrene, α-methylstyrene, and p-methylstyrene can be used.

Examples of the cation exchanger catalyst used in reacting these raw materials include perfluoro ion exchangers.

This reaction yields a mixture of styrene dimers and styrene-alkylbenzene adducts, but aliphatic unsaturated double bonds of styrene are present in these products (abundance varies depending on raw material composition and reaction reaction). (depending on the conditions), only such aliphatic unsaturated double bonds are selectively hydrogenated using, for example, a nickel-based catalyst such as Ni/diatomaceous earth or Raney nickel. In this way, a colorless and odorless high-boiling hydrocarbon oil is obtained. Incidentally, although some heavy substances may be generated in the step of obtaining the mixture, a mixture consisting of each of the compounds 2N) to (Ill) can be easily obtained by distillation.

(Function) Formulas (1) to (1) constituting the solvent for pressure-sensitive copying paper of the present invention
Each of the compounds represented by I[[] individually has some characteristics as a high boiling point solvent, but a system in which the three are mixed has advantages such as increased dye solubility and color development speed. shows. In other words, the solvent for pressure-sensitive copying paper of the present invention does not necessarily have to consist of a single compound as long as it satisfies certain requirements. Become something. There is no particular restriction on the composition of such a solvent, but the compounds represented by formulas (I) to (I) each contain 50 to 90.5 to 25.5 to 20
(%) is advantageous.

Next, in the manufacturing method of the present invention, the above formulas (1) to (I
The feature is that each compound represented by I) is not synthesized separately and then mixed, but is synthesized simultaneously, and this is the main factor why the present invention is an economical production method. There is. That is, each of the compounds represented by formulas (1) to (I[[) can be synthesized by various known methods, but it is most efficient and economical to synthesize them according to the production method of the present invention described above. It is true.

In the production method of the present invention, there is no particular restriction on the composition of styrenes and alkylbenzene, but in order to obtain a high-boiling oil with a preferred composition, it is desirable that the concentration of styrenes is 5 to 40%. In addition, in this reaction, the catalyst is preferably used in an amount of 0.1% or more, preferably 1 to 10%, based on the styrene in order to increase its effectiveness as a catalyst, and the reaction temperature is preferably 50 to 140'C. .

Next, the conditions for the hydrogenation reaction in the production method of the present invention are as follows:
There is no particular restriction as long as only aliphatic unsaturated double bonds can be selectively hydrogenated, but using 0.5 to 5% Ni/diatomaceous earth catalyst, 50 to 70°C, hydrogen pressure 5.
It has been found that preferable results can be obtained when the reaction is carried out at 0 to 100 kg/cm''.

(Example) Next, the present invention will be explained by examples.

A reactor having a volume of 104' and having an agitator and a condenser,
As a catalyst, 20g of cation exchange BIJ (DuPont's Nafion-117) was installed.
Introducing 1 kg of styrene and 4 kg of mixed xylene,
The reaction was carried out at 100°C for 4 hours. The yield of the product at this time was 1.41 kg, and its average molecular weight was 258.

Next, after separating the catalyst and the reaction product, unreacted light bones are distilled off, and Ni/
Hydrogen pressure 100kg/c+a using 28g diatomaceous earth catalyst
'', the reaction was carried out for 3 hours at 70°C. After the reaction, the catalyst and the reaction product were separated, and the reaction product was further distilled under reduced pressure to obtain each of the formulas (1) to (II[) above. 0.98 kg of a mixture of compounds was obtained.

The abundance of the compounds of formulas (I) to (III) in these mixtures was determined by gas chromatography and nuclear magnetic resonance spectroscopy, and was found to be 79%, 12%, and 9%, respectively.
Met.

Approximately 300 m internal volume with a stirring device and a cooler 7! 180 g of toluene was placed in a three-neck flask, and 0.4 g of the same catalyst as in Example 1 was stirred at 100° C., and 20 g of styrene was added dropwise to react for 1 hour. After separating the reaction product from the catalyst and distilling off the light bones, the internal volume was approximately 150cc.
Hydrogenation was carried out in the same manner as in Example 1 except that an autoclave was used to obtain 31.4 g of hydrogenated oil.

In addition, the boiling point of the hydrogenated oil obtained in each of the above examples is 28
It was within the range of 0 to 340°C.

Regarding the oil obtained in Example 1, crystal violet lactone (CVL), which is a typical dye for pressure copying paper, was used.
), CV
The amount of L was increased to 3 g, 3.5 g, and 4 g for dissolution, but no CVL precipitation was observed in any case even after standing for 24 hours.

A microcapsule dispersion was obtained by a known coacervation method using the 3% CVL lysate obtained in Soutachi Sarado Example 3. The resulting dispersion was applied to paper and then dried. When the thus obtained microcapsule-coated paper was placed on top and a paper coated with a color developer was placed on the bottom, printing was performed with a ballpoint pen, and a clear blue color was instantly obtained.

(Effects of the Invention) As explained above, in the present invention, a solvent for pressure-sensitive copying paper consisting of a mixture of predetermined compounds can be synthesized simultaneously, instead of synthesizing the compounds separately and then mixing them. By doing so, it is possible to produce the solvent at a very low cost, and the solvent produced in this manner has the advantage that it is extremely excellent for use in pressure-sensitive copying paper.

Claims (1)

[Claims] 1. The following general formulas: ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (I) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ( III) A solvent for pressure-sensitive copying paper comprising each compound represented by the following formulas (R_1, R_2, R_3 and R_4 in formulas (I) to (III) are each H or an alkyl group). 2. The following general formulas: ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (I) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (III) (Formula ( I ) to (III), R_1, R_2, R_3 and R_4 are each -H or an alkyl group). The following general formulas, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (IV) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (V) (R_1, R_2, R_3 and R_4 in formulas (IV) and (V) are ) are reacted to obtain a mixture of styrene dimers and styrene-alkylbenzene adducts, and then the aliphatic unsaturated diamers in these reaction products are reacted. A method for producing a solvent for pressure-sensitive copying paper, which comprises hydrogenating a double bond and then distilling it to obtain a mixture of compounds represented by the above general formulas (I) to (III).