JPH02214706A - Production of conducting agent for information paper - Google Patents

Abstract

PURPOSE:To provide a conducting agent comprising a polymer having a specific mol.wt. and a specified remaining monomer content, not causing any discoloration, free from any odor and useful for information paper by polymerizing a specific quaternary ammonium salt compound having a plurality of unsaturated groups in the presence of a radical polymerization catalyst comprising a water-soluble azo compound. CONSTITUTION:A quaternary ammonium salt compound of the formula (R<1> and R<2> are H or methyl; R<3> and R<4> are 1-3C alkyl and the total carbon atom number in the alkyl groups R<3> and R<4> is <=4; X is halogen) is polymerized in the presence of a radical polymerization catalyst comprising a water-soluble azo compound [e.g. 2,2'-azobis(2-methylpropionamidine) hydrochloride] to provide a polymer having a mol.wt. corresponding to an intrinsic viscosity of <=0.37 measured in a 1mol NaCl aqueous solution at 30 deg.C, having a remaining monomer content of <=20wt.% and used as a conducting agent for information paper.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing a conductive agent for information paper.

[Conventional technology/issues] Conventionally, electronic copy paper and electrostatic recording paper, which are information paper, have been developed in order to reduce the humidity dependence of electrical resistance and adjust the electrical resistance to the required value to obtain clear images. However, in recent years, the types of information paper that undergoes conductive treatment have expanded to include CAD drawing paper, color copy paper, and thermal paper, and there is a growing demand for improved performance of conductive agents for information paper. There is.

It has been known that various polymer electrolytes, particularly cationic polymer electrolytes, are useful as conductive agents for information paper.

For example, polyvinylbenzyltrimethylammonium chloride, polytrialkylaminoethyl acrylate, etc. are already known, but these conductive agents do not have sufficient conductivity, or the conductive treated paper becomes colored or has an odor. There were other drawbacks.

Therefore, in order to improve the coloring and odor of treated paper, it is known that polydimethyldiallylammonium chloride, which is one of the cationic polymer electrolytes, is used as a conductive agent for information paper (Japanese Patent Publication No. 44 15564), the method for polymerizing polydimethyldiallylammonium chloride described in the publication, i.e., the method for polymerizing polydimethyldiallylammonium chloride described in the publication, ie.
The polymerization method described on page 128 (1957) uses t-butyl peroxide and 2,2'-azoisobutyronitrile as radical polymerization catalysts, and the conductive agents produced by these methods are sufficiently satisfactory. It was not possible to obtain such conductivity.

Accordingly, an object of the present invention is to provide a method for producing a conductive agent for information paper, which does not cause the paper subjected to conductive treatment to be colored or have an odor, and which has excellent conductivity.

[Means for Solving the Problems] As a result of extensive research into conductive materials for information paper made of polydialkyl diallylammonium halide, the present inventors surprisingly found that a water-soluble azo radical polymerization catalyst was used as a radical polymerization catalyst. The present invention was completed based on the discovery that the material used was extremely effective as a conductive agent for information paper.

That is, the present invention relates to the general formula (1) (wherein R- and R-values may be the same or different and represent a hydrogen atom or a methyl group, R3 and R4
may be the same or different, and the number of carbon atoms is 1 to
3, where the total number of carbon atoms in the alkyl groups of R3 and R4 is 4 or less, and X represents a halogen atom) is used as a polymerization catalyst for water-soluble azo radical polymerization. Information characterized in that the polymer is polymerized in the presence of a catalyst to obtain a polymer having a molecular weight of 0.37 or less and having a residual monomer content of 20% by weight or less, which exhibits an intrinsic viscosity measured in a 1 mol N1ce aqueous solution at 30°C. A method for manufacturing a conductive agent for paper.

[Function] In the method of the present invention, the compound represented by the above general formula (1) is
Cyclization polymerization is carried out using a water-soluble azo radical polymerization catalyst.

The water-soluble azo radical polymerization catalyst used in this case is not particularly limited, and any water-soluble azo radical polymerization catalyst can be used. For example, 2.
2'-azobis(2-methylpropionamidine) dihydrochlorite, 2.2'-azobis[2-(2-imidacillin-2-yl)propane] dihydrochloride, 2.2'azobis[2-methyl- N-(phenylmethyl)-propionamidine 1 dihydrochlorite,
2゜2'-azobis(2-methyl-N-2-phenylpropion-amidine) dihydrochloride, 2.2'
One or more types of known water-soluble azo radical polymerization catalysts such as -azobis[N-(2-hydroxyethyl)-2-methyl-propionamidine 1 dihydrochlorite can be used.

In the present invention, the monomer represented by the above general formula (1) has an intrinsic viscosity (measured at 30° C. with a 1 mol NaCl aqueous solution) of 0.37 or less, preferably 0.37 to 0.05, more preferably Lto, It is important to polymerize so that the molecular weight exhibits a molecular weight of 37 to 0.1, and if the molecular weight is larger than the above range and the viscosity is large, there will be a significant decrease in workability.

When the intrinsic viscosity is small, it does not affect workability in any way, but in order to keep the amount of residual monomer within the range described later, it is preferable that it is within the above range.

The polymerization method for obtaining a polymer exhibiting the above-mentioned intrinsic viscosity is not particularly limited, and conventionally known radical polymerization (however, the above-mentioned catalysts are used) may be used. , the reaction temperature may be adjusted appropriately.

That is, when the monomer concentration in the reaction system is low, the molecular weight tends to be low, when the concentration is high, the molecular weight tends to be high, when the amount of catalyst is low, the molecular weight is easy to become high, and when it is large, the molecular weight is easy to become low, and when the reaction temperature is low, the molecular weight is high, When the temperature is high, the molecular weight tends to be low.

Therefore, preferably the above-mentioned water-soluble azo radical polymerization catalyst is used in an amount of 1 to 20% by weight, preferably 2 to 10% by weight, based on the monomer represented by the general formula (1). The monomer concentration expressed by 10 to 90% by weight,
Preferably the amount is 20 to 50% by weight, and the reaction temperature is 40 to 1%.
The reaction is preferably carried out at 10°C, preferably from 50 to 70°C.

Here, if the reaction temperature is lower than the above range, it tends to be difficult for polymerization to proceed, and if the reaction temperature is higher than the above range, it tends to be difficult to control the reaction, so from these points as well, it is difficult to proceed with polymerization. It is preferable to set it as temperature.

Further, in the present invention, it is necessary to carry out the reaction until the residual monomer content becomes 20% by weight or less, preferably 10% by weight or less. If the amount of residual monomer is greater than the above range, sufficient electrical conductivity cannot be obtained.

In order to achieve the above monomer residual amount, it is sufficient to allow sufficient reaction time to complete the polymerization reaction, and although the reaction time is not particularly limited, it can be set as appropriate between approximately 4 hours and 60 hours. You can choose as you like (Although the residual monomer will never be completely reduced to zero, for the sake of convenience here, it is assumed that the polymerization reaction is completed when the polymerization reaction by the catalyst used no longer proceeds).

In the present invention, other radical polymerization catalysts such as peracid radical polymerization catalysts such as potassium persulfate and ammonium persulfate, and organic radical polymerization catalysts such as t-butyl hydroperoxide and benzoyl peroxide may be used without departing from the purpose of the present invention. Although it is acceptable to use peroxide-based radical polymerization catalysts, it is preferable to avoid using these other radical polymerization catalysts as much as possible, and even if they are used, they account for 20% by weight or less, preferably 10% by weight of the total catalyst. The content is more preferably 5% by weight or less.

This is probably due to the following two reasons. That is, (2) persulfate-based radical polymerization catalysts and organic peroxide-based radical polymerization catalysts have low polymerization activity with respect to the compound of general formula (1), so a large amount of unreacted monomer remains, resulting in a decrease in conductive performance.

(2) If the amount of radical polymerization catalyst added is increased in order to reduce the amount of unreacted monomers, the radical polymerization catalyst itself has an adverse effect on conductivity, so even if the amount of unreacted monomers can be reduced, the conductivity will decrease.

Preferred compounds of the general formula (!) used in the present invention are those in which R3 is a methyl group or an ethyl group, R4 is a methyl group or an ethyl group, and particularly those in which both R3 and R4 are a methyl group or an ethyl group. is preferred, and more preferably R3 and R4 are both methyl groups.

There is no particular limitation on the method of conducting conductive treatment on paper using the conductive agent for information paper obtained according to the present invention, and conventionally known methods can be used as appropriate.

For example, an aqueous solution of the conductive agent for information paper may be prepared, and the paper may be subjected to conductive treatment using an off-machine coater, a gate roll size press, or the like.

There is no problem in using the conductive agent obtained by the present invention in combination with other additives as necessary within the scope of the purpose of the present invention, and generally various water-soluble polymers (starch, poval, etc.) A combination of various pigments such as calcium carbonate can be used arbitrarily. In addition, water resistant agents,
Additives such as sizing agents can also be used optionally.

The amount of the conductive agent for information paper of the present invention to be used in paper is not particularly limited, but is preferably 0.1 to 10 y/m'', more preferably 0.5 to 7 g/m''.

[Examples] The present invention will be further explained with reference to Examples below, but the present invention is not limited to the following Examples.

150 g of dimethyldiallylammonium chloride and 350 g of water were placed in a 11-glass four-bottle flask equipped with a K1 Takumi thermometer, a condenser, and a stirrer and dissolved, and the solution was heated to 60°C while nitrogen gas was blown in to replace the nitrogen gas. I did this.

Next, 2.0% by weight of 2.2'
- Add 3.0 g of azobis(2-methylpropionamidine) hydrochloride and polymerize for 15 hours while maintaining the reaction temperature at 60 ± 5°C to prepare a conductive agent for information paper as an aqueous polymer solution with a solid content of 30% by weight. Obtained.

The amount of unreacted monomers in the obtained aqueous polymer solution was 4.
2% by weight, and the intrinsic viscosity (measured at 30° C. with a 1 molar NaCl aqueous solution) was 0.34.

The same reaction as in Example 1 was carried out except that the amount of radical polymerization catalyst was limited to 3.0% by weight based on the monomers. A conductive agent for information paper was obtained as a combined aqueous solution.

Note that the intrinsic viscosity measured in the same manner as in Example 1 was 0.31.

The same reaction as in Example 1 was carried out except that 2.2'-azobis[2-<2-imidacylin-yl)propane] dihydrochlorite was used as the radical polymerization catalyst, and the unreacted monomer 6. A conductive agent for information paper was obtained as an aqueous polymer solution having a solid content of 3% by weight and a solid content of 30% by weight.

Note that the intrinsic viscosity measured in the same manner as in Example 1 was 0.21.

Example 1 A--The same reaction as in Example 1 was carried out except that diethyldiallylammonium chloride was used instead of dimethyldiallylammonium chloride.

A conductive agent for information paper was obtained as an aqueous polymer solution containing 7.5% by weight of unreacted monomer and 30% by weight of solid content. In addition, Example 1
The intrinsic viscosity measured in the same manner as above was 0.27.

The same reaction as in Example 1 was carried out except that the polymerization time was changed to 7 hours, and a conductive agent for information paper was prepared as an aqueous polymer solution containing 14.3% by weight of unreacted monomer and 30% by weight of solid content. Obtained. Note that the intrinsic viscosity measured in the same manner as in Example 1 was 0.31.

L19L When the same reaction as in Example 1 was carried out except that ammonium persulfate was used as the radical polymerization catalyst, there was 25.7 weight 1% of unreacted monomer, so ammonium persulfate was added to the monomer by 2°0. The reaction was carried out for 15 hours by adding % by weight to obtain an aqueous polymer solution containing 8.9% by weight of unreacted monomers and 30% by weight of solids. Note that the intrinsic viscosity measured in the same manner as in Example 1 was 0.53.

L1 Takumi The same reaction as in Example 1 was carried out except that t-butyl hydroperoxide was used as the radical polymerization catalyst.
Since there was 33.1% by weight of unreacted monomer, an additional 2.0% by weight of t-butyl hydroperoxide was added.
The reaction was carried out for 5 hours to obtain an aqueous polymer solution containing 9.7% by weight of unreacted monomers and 30% by weight of solids. In addition, Example 1
The intrinsic viscosity measured in the same manner as above was 0.15.

JtJl-Example'' The same reaction as in Example 1 was carried out except that the time was changed to 4 hours to obtain an aqueous polymer solution containing 29.4% by weight of unreacted monomers and 30% by weight of solids. Note that the intrinsic viscosity measured in the same manner as in Example 1 was 0.21.

The same reaction as in Example 1 was carried out except that 200 g of dimethyldiallylammonium chloride and 300 g of water were used and the amount of radical polymerization catalyst was 0.5% by weight based on the monomer. A conductive agent for information paper was obtained as an aqueous polymer solution having a solid content of 8.1% by weight and a solid content of 40% by weight. In addition,
The intrinsic viscosity measured in the same manner as in Example 1 was 0.60.

Using the conductive agents for information paper obtained in Examples 1 to 5 and Comparative Examples 1 to 4, paper was treated according to the following method, and the surface resistance value was measured. The results are shown in Table 1 below.

A. Conductive agent treatment method A conductive agent aqueous solution prepared to have a solid content of 10% by weight was coated on paper using a bar coater so as to cover the solid content of 3.5.7 g/11' and dried.

B1 Surface resistance measurement method Conductive treated paper at relative humidity (RH) 25.45.65%
Surface resistance values were measured in accordance with JIS-6911 under each atmosphere (20° C.%).

The measurement was performed using a digital electrometer model TR8652 manufactured by Atopan Test Co., Ltd. at a measurement voltage of 10V.

Table 1: Surface resistance The electrical conductivity is significantly superior to that of paper treated with polymers produced using conventional methods.

Moreover, according to the conductive agent for information paper of the present invention, the treated paper does not change color or acquire an odor.

Claims (1)

[Claims] General formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R^1 and R^2 may be the same or different, and hydrogen atoms or represents a methyl group, R^3 and R^4 may be the same or different and represent an alkyl group having 1 to 3 carbon atoms, where R^3 and R^4
The total number of carbon atoms in the alkyl groups of 4 is 4 or less, and X represents a halogen atom) was polymerized in the presence of a water-soluble azo radical polymerization catalyst as a polymerization catalyst, mole N
A method for producing a conductive agent for information paper, characterized in that a polymer having a molecular weight exhibiting an intrinsic viscosity of 0.37 or less as measured in an aCl aqueous solution and a residual monomer content of 20% by weight or less is obtained.