JP2779966B2 - Production method of rosin emulsion sizing agent - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for producing a rosin-based aqueous emulsion useful as a sizing agent for papermaking, and more particularly to a rosin-based emulsion sizing agent by a phase inversion method. The present invention relates to an improvement in the method for producing

[Related Art] In the papermaking industry in recent years, from the viewpoints of strengthening regulations on factory wastewater and reducing the cost of water use, it is desired to collect and reuse papermaking wastewater as much as possible. in this case,
The quality of water for papermaking is inevitably reduced, and it is extremely difficult for a saponified rosin sizing agent that has been widely used in the past to give a sufficient size effect to the formed paper. For this reason, emulsion type rosin sizing agents have been spotlighted in recent years.

[Problems to be Solved by the Invention] As a method for producing a rosin-based emulsion sizing agent, a high-pressure emulsification method in which a rosin-based substance is emulsified using a homogenizer, or a solution in which a rosin-based substance is dissolved in an appropriate organic solvent is used. A solvent distillation method in which an emulsifier is emulsified in an aqueous medium in the presence of an emulsifier, and then the organic solvent is distilled off, is known. There is known an inversion method for preparing an O / W emulsion by preparing an O-type emulsion and then adding water to invert the rosin-based material from a continuous phase to a dispersed phase.

However, rosin emulsion sizing agents produced by the conventional inversion method can obtain uniform and fine rosin emulsion particles unless the dispersant is used in a relatively large amount of 4 to 8% based on the rosin material. Can not. However, when such a rosin-based emulsion sizing agent is used in papermaking, foaming occurs in the papermaking system, and not only pinholes and the like are generated in the formed paper, but also pitch trouble is caused.

[Means for Solving the Problems] In order to solve the above problems, the present inventors have proposed a rosin-based substance capable of obtaining uniform and fine rosin emulsion particles even when the amount of the dispersant used is reduced. As a result of repeated studies, if a mixture of phenolic resin and reinforced rosin is used as the rosin-based substance for the inversion method, an emulsion in which the rosin-based substance is fine and evenly dispersed can be obtained even with a relatively small amount of dispersant. Was found to be.

That is, the method for producing a rosin-based emulsion sizing agent according to the present invention comprises mixing a rosin-based material in a molten state with water containing a dispersant to form a dispersion in which the rosin-based material is a continuous phase and water is a dispersed phase. In a method for producing a rosin-based emulsion sizing agent, an aqueous emulsion in which water is a continuous phase and a rosin-based substance is a dispersed phase is obtained by forming a liquid and then inverting the phase by adding water to the dispersion. A mixture of a phenolic resin and a reinforced rosin is used as the rosin-based material.

In the method of the present invention, the phenolic resin refers to an alkylphenol formalin addition condensate, a phenol-modified petroleum resin, and the like, and the molecular weight thereof is about 500 to 2,000, preferably about 1,000. Incidentally, an alkylphenol formalin addition condensate can be produced by adding formaldehyde to an alkylphenol to produce a methylolated alkylphenol and then subjecting it to a condensation reaction of methylol groups to produce a large amount. In addition, phenol-modified petroleum resin, by reacting phenol or phenol compound to petroleum resin,
Alternatively, in the presence of phenol or a phenol compound,
By producing a petroleum resin, a phenol-modified petroleum resin having a hydroxyl group in the molecule can be obtained, and its molecular weight can be adjusted by the molar ratio of the reactants and the amount of the catalyst added.

As the fortified rosin, those obtained by reacting a rosin such as a gum rosin or a tall oil rosin with an α, β-unsaturated polybasic acid by a known method can be used. Examples of the α, β-unsaturated polybasic acid include fumaric acid, maleic anhydride, itaconic acid, acrylic acid, methacrylic acid, and the like. Fumaric acid addition is most preferable, and the addition amount is 6 to 15%. Preferably it is in the range of 9 to 13%. In the present invention, a part of the reinforced rosin can be replaced with a phenol resin-modified reinforced rosin, if desired.

The dispersant of the present invention is substantially the same as a dispersant known in the art except that its use amount is about half to 2 to 4% (based on rosin-based material) compared to the conventional inversion method. No different. Accordingly, polyoxyethylene sulfosuccinic acid half-ester salts of higher alcohols, alkyl phenols, alkyl aryl phenols or polystyrene phenols, polyoxyethylene sulfates of alkyl phenols, alkyl aryl phenols or polystyrene phenols, alkyl benzene sulfonates, α-olefin sulfones Anionic surfactants such as acid salts can be used in the present invention, and nonionic surfactants can be used in combination with them. In particular, the use of polyoxyethylene sulfosuccinic acid half-ester salts of alkylphenols and alkylarylphenols is preferred in the present invention.

According to the method of the present invention, a mixture of a reinforced rosin and a phenolic resin corresponding to 5 to 20% by weight thereof is heated and melted, and the melt is thoroughly stirred while dropping an aqueous solution containing a dispersant, First, a homogeneous W / O emulsion is prepared. Then, warm water of this emulsion is added under vigorous stirring to invert the phase to prepare an O / W type aqueous emulsion.

In this case, the total amount of the aqueous solution containing the dispersant is preferably in the range of 10 to 20% by weight of the melt. When the aqueous solution is dropped, the temperature of the melt is set at 20 degrees below its melting point.
It is preferable to maintain the temperature at a high temperature of at least 100 ° C. so that the temperature of the mixture at the end of the dropwise addition of the aqueous solution of the dispersant is about 100 ° C. Subsequently, the desired aqueous emulsion sizing agent is obtained by successively inverting the temperature of the mixture by dripping warm water at 90 to 95 ° C. with stirring.

[Operation] The rosin-based emulsion sizing agent obtained by the method of the present invention exhibits a good sizing effect despite the small content of the dispersing agent. As a result of being melted down, the melt has improved affinity for water and improved dispersibility in water as compared with the case of the reinforced rosin alone, and therefore, even a small amount of a dispersant can form fine and uniform emulsion particles. It is estimated to be.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. Prior to this, Preparation Examples of the fortified rosin used in the Examples and Comparative Examples will be described.

Preparation Example of Reinforced Rosin In a reactor equipped with a stirrer, a thermometer, an addition port and a condenser, 100 parts by weight of rosin is heated and melted, and 9 parts by weight of fumaric acid is added thereto and the mixture is heated at 195 to 200 ° C. The reaction was performed for 5 hours, and it was confirmed that no unreacted numaric acid was present, and the reaction was completed. The properties of the obtained 9% fumarated rosin were an acid value of 219 and a melting point of 92 ° C.

Example 1 A reactor equipped with a stirrer, a thermometer, a dropping funnel and a condenser was charged with 92.5 parts by weight of the above 9% fumarated rosin,
7.5 parts by weight of a phenolic resin was charged and heated to 140 ° C. to melt. Subsequently, 17.5 parts by weight of an aqueous solution containing 3.5 parts by weight of nonylphenol polyexethylene (n = 10) sulfosuccinic acid half ester sodium trim was dropped and mixed with stirring to obtain a W / O emulsion. At this time, the temperature in the reactor was 96 ° C.

89.5 parts by weight of 90 ° C. warm water was added dropwise to this emulsion with stirring to invert the phase, and the dispersed particles were uniformly and finely concentrated at 50%.
Aqueous emulsion size was obtained. Then it was immediately cooled to 30 ° C.

Example 2 An aqueous emulsion sizing agent having a concentration of 50% was obtained in the same manner as in Example 1 except that the amount of 9% fumarated rosin was changed to 85 parts by weight and the amount of phenolic resin was changed to 15 parts by weight. Was.

Example 3 The same reactor as in Example 1 was charged with 80 parts by weight of 9% fumarated rosin, 10 parts by weight of a phenolic resin and 10 parts by weight of alkenyl succinic acid (average molecular weight: 320), and heated and melted.
Thereafter, the same operation as in Example 1 was repeated to obtain an aqueous emulsion sizing agent having a concentration of 50%.

Comparative Example 1 An aqueous emulsion for comparison was obtained in the same manner as in Example 1 except that the phenolic resin was not used and the amount of 9% fumarated rosin was increased to 100 parts by weight.

Comparative Example 2 Instead of using no phenolic resin, the amount of 9% fumarated rosin was increased to 100 parts by weight, and a dispersant, nonylphenol polyexethylene (n = 10) was used.
The same operation as in Example 1 was performed except that the amount of sodium sulfosuccinate half ester was increased from 3.5 parts by weight to 5 parts by weight, and the amount of the aqueous solution containing the dispersant was increased to 25 parts by weight. An aqueous emulsion for comparison was obtained.

The appearance, light transmittance, foamability and size effect of each emulsion sizing agent obtained in the above Examples and Comparative Examples were determined by the following methods. Table 1 shows the results of the appearance and the light transmittance, and Table 2 shows the effects of the foamability and the size effect.

Appearance 50cc of the sizing agent is collected in a 200cc transparent glass bottle. After sealing, the bottle is inverted and allowed to stand, and the state in which the sizing agent flows down in a thin layer on the bottle wall surface is visually observed.

：: No coarse particles are present, and a clear feeling appears within 10 seconds.

：: No coarse particles are present, and transparency appears after 20 seconds.

Δ: Coarse particles are present, and a clear feeling appears after 20 seconds or more.

Light transmittance Concentration of the sizing agent in solid form using deionized water
Dilute to 0.05% by weight and use a diffraction grating photoelectric colorimeter (Spectron
ic 20 manufactured by Shimadzu Corporation), the light transmittance at a wavelength of 560 nm was measured. The light transmittance of each sizing agent is shown as a relative value when the light transmittance of deionized water alone is set to 100%, and the higher this value is, the finer the dispersed particle size of the sizing agent sample is.

Foaming test Pulp slurry with a concentration of 0.75% (pulp L-
80 ml of (BKP CSF 400 ml) is collected in a 100 ml measuring cylinder with a stopper, and 1 ml of a 1% band solution is added thereto and shaken 20 times. Next, 1 ml of a diluent for a sizing agent having a solid content of 1% is added, and the mixture is shaken up and down 20 more times. After that, the sample is allowed to stand still and the amount of floating species generated after 5 minutes has elapsed is measured. The higher the numerical value, the greater the foamability.

Size effect test 20% talc and 0.2% emulsion sizing agent are added to 2.4% L-BKP (CSF 400ml) pulp slurry based on the weight of the dry pulp and mixed well. Was mixed (see Table 2) to obtain a prepared pulp slurry. Next, TA
Hand-punched with PPI standard sheet machine, press pressure 3.5Kg / cm ²
And then dried with a drum dryer (surface temperature 70 ° C.) for 1 minute to prepare a hand-made paper. The resulting handmade paper is
It was equivalent to 60 g / m ^2, and after conditioning, the degree of Stigecht sizing was measured according to JIS P-8122.

[Effects] As is clear from the above description, the rosin-based emulsion sizing agent obtained by the method of the present invention has a very fine and stable dispersion of size particles and a small content of a dispersing agent. There is a feature that foaming is extremely small at the time of addition to the slurry, and the size effect is also good. Therefore, the present invention has a high industrial value as a method for producing a sizing agent capable of solving troubles caused by the sizing agent accompanying deterioration of water used in the papermaking process.

Claims (2)

(57) [Claims] A rosin-based material in a molten state and water containing a dispersant are mixed to form a dispersion in which the rosin-based material is a continuous phase and water is a dispersed phase. In the method for producing a rosin-based emulsion sizing agent, which obtains an aqueous emulsion in which water is a continuous phase and a rosin-based substance is a dispersed phase by adding and reversing the phase, a phenolic resin is used as the rosin-based substance. A method for producing a rosin-based emulsion sizing agent, comprising using a mixture of rosin-based emulsion sizing agent and reinforced rosin. 2. The method according to claim 1, wherein the amount of the dispersant used is in the range of 2 to 4% by weight of the rosin-based material.