JPS5836019B2 - Method for producing emulsions containing rosin substances - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an aqueous emulsion containing a rosin-based material.

The rosin-based substances of the present invention are Gumkuchijin, Woodkuchijin,
Tall oil rosin, its modified products and mixtures.

Aqueous emulsions of rosin-based substances are widely used in various technical fields such as paper sizing agents, fiberboard sizing agents, waterproofing agents, adhesives, and coating agents.

Among these types of emulsions, those in which rosin is directly dispersed in an aqueous medium are generally unstable due to the crystallinity of rosin, making it difficult to store for long periods of time, and causing foaming when used. Or, the emulsified particles may become coarse and the desired effect may not be achieved.

For this reason, for example, in the case of rosin-wax emulsions used as sizing agents for fiberboards, amorphous rosin is produced by reacting rosin with formaldehyde, maleic anhydride, etc. in advance to eliminate the crystallinity of the rosin. There are many examples where system substances are used.

However, emulsions produced using non-crystalline mouth-watering substances according to the prior art as described above generally have a high viscosity and are inconvenient to handle. There were also some drawbacks.

In view of these circumstances, the present invention has been developed to provide an emulsion that has excellent stability and can be stored for a long period of time, has a relatively low viscosity even at high concentrations, produces little foaming when used, and has the desired effect sufficiently. The purpose of the present invention is to provide an aqueous emulsion of a rosin-based substance that exhibits the following properties.

As a result of repeated research aimed at developing the above-mentioned aqueous emulsion, the present inventor found that an amorphous rosin-based material can be obtained by reacting a suitable amount of a specific metal compound with a rosin-based material. It has been found that by dispersing this amorphous rosin-based material in an aqueous medium, an aqueous emulsion of a rosin-based material suitable for the purpose of the present invention can be obtained.

Therefore, the method for producing an aqueous emulsion according to the present invention is a method for producing an emulsion in which a rosin-based substance is dispersed in an aqueous medium. When the substance is a modified rosin, it refers to 5 to 30 moles of the rosin before modification.

The method is characterized in that it uses an amorphous reaction product obtained by reacting an alkali metal compound or a zinc compound with a rosin material in an amount that converts it into a metal salt.

The method of the present invention is applicable to the production of emulsions containing rosin substances in general, and can of course be used, for example, to the production of the rosin-wax emulsions described above.

In the present invention, the amorphous reactive substance used as the rosin-based material is prepared by reacting the rosin-based material and a metal compound.

The metal compound to be reacted with the rosin-based substance is a compound of an alkali metal or zinc, and it is practically preferable to use oxides, hydroxides, acetates, etc. of the metals.

The reaction between a rosin-based substance and a metal compound is generally carried out at a temperature of approximately 60°C or higher by melting the rosin-based substance and adding the metal compound to it, but it produces a rosin-based substance-wax emulsion. When doing so, there is no problem in reacting a metal compound with a mixture of rosin-based substances and wax.
This method is industrially advantageous because the reaction can proceed more quickly.

In the reaction between a rosin-based substance and a metal compound, the amount of metal compound used is extremely important, and in the present invention, the amount of metal compound used must be sufficient to convert 5 to 30 moles of rosin into a metal salt. It won't happen.

The reaction between rosin and metal compound proceeds almost quantitatively at a reaction ratio of 2 moles of rosin to 1 mole of metal compound.

Therefore, in order to convert 5 to 30 moles of rosin into metal salt, it is necessary to add 0.025 moles of metal compound to 1 mole of rosin.
~0.15 mol needs to be reacted.

If the conversion of rosin into a metal salt is less than 5 molar percentage of the rosin, it is difficult to completely eliminate the crystallinity of the rosin. If this is used, the melting point of the reaction product will rise too much, making emulsification of the product even more difficult.

The reaction product thus prepared is non-crystalline and is used as a rosin-based material when producing an aqueous emulsion of a rosin-based material. It can also be used in combination with

In dispersing the amorphous reaction product of the present invention in an aqueous medium, any known dispersion method can be used, including when mixed with a rosin-based material of the prior art.

By the way, methods for dispersing rosin-based substances in an aqueous medium include: melting the rosin-based substance and dispersing and emulsifying it using an emulsifier, using an emulsifier and protective colloid together, using a solvent together, and after using a solvent together. A method of distilling off only the solvent and a method of using a high-pressure emulsifier are known, and any of these methods can be employed in the present invention.

The aqueous emulsion of the rosin-based substance produced by the method of the present invention has excellent stability because the rosin-based substance is amorphous, has a relatively low viscosity even at high concentrations, and produces little foaming when used. It can be widely used in paper sizing agents, fiberboard sizing agents, waterproofing agents, adhesives, coating materials, etc.

Example 1 Amorphous rosin materials A to E shown in Table 1 were prepared by changing the types and reaction ratios of rosin and metal compounds.

The reaction was carried out at a temperature of 100 to 150° C. and was terminated when the contents of the reactor became homogeneous and transparent.

Each of the amorphous oral substances A to E10 prepared in this way
Dissolve 0g in 80g of toluene, and add 33g of rosin soap aqueous solution of 15% and 140g of water to this toluene solution.
was added and mixed to obtain a preliminary emulsion.

This was passed through a high-pressure homogenizer three times to obtain a uniform fine-sized emulsion.

This emulsion was heated under reduced pressure (50 to 60 mmHg
) Toluene was recovered by di-distillation to obtain an aqueous emulsion of a rosin-based substance.

For comparison, aqueous emulsions were prepared in the same manner as above using five types of rosin substances JN shown in Table 1.

Table 1 summarizes the presence or absence of crystal precipitation during toluene recovery during the process of preparing each aqueous emulsion and the stability of each aqueous emulsion.

Example 2 150 g of rosin and 150 g of paraffin wax (melting point 6
(4°C) were mixed and melted, a predetermined amount of the metal compound was added thereto, and the mixture was reacted at 110 to 120°C.

The reaction was terminated when the reaction product became homogeneous and transparent, and rosin-based substances F, G, and H, which were mixtures of amorphous rosin and paraffin wax, were obtained.

200g of each of the above rosin substances F-H at 85°C.
Melt this with 67g of rosin soap aqueous solution of 15 pieces,
10% caseinate ammonia aqueous solution 60g and warm water 15g
3 g was added and stirred to obtain a preliminary emulsion.

This preliminary emulsion was passed through a high-pressure homogenizer three times to obtain an aqueous emulsion of a rosin-based material having a fine particle size.

For comparison, rosin-based material 0 in the case where no metal compound is reacted and rosin-based material which is a 1:1 mixture of modified rosin 2 (maleated rosin) and paraffin wax used as a comparative example in Example 1. An aqueous emulsion was obtained using P in the same procedure as above.

For each aqueous emulsion, presence or absence of crystal precipitation during pre-emulsification;
The properties of the aqueous emulsions are also summarized in Table 2.

Claims (1)

[Scope of Claims] 1. In a method for producing an aqueous emulsion containing a rosin-based substance, an amount of an alkaline earth metal compound or a zinc compound such that 5 to 30 moles of rosin in the rosin-based substance is converted into a metal salt. 1. A method for producing an aqueous emulsion containing a rosin-based substance, characterized by using an amorphous reaction product obtained by reacting the above with a rosin-based substance. 2. The method according to claim 1, wherein an oxide, hydroxide or acetate of an alkaline earth metal or zinc is used as the alkaline earth metal compound or zinc compound. 3. The method according to claim 1, wherein the reaction between the gin-based substance and the alkali metal compound or zinc compound is carried out in the presence of wax.