JP3255072B2 - Method for producing aqueous emulsion of rosin-based material, aqueous emulsion composition and sizing agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an aqueous emulsion of a rosin-based substance having excellent storage stability and mechanical stability, which cannot be obtained by conventional methods, by using a high-shear rotary emulsifier. The present invention relates to an aqueous emulsion composition of the rosin-based material and a sizing agent for papermaking using the same, which exhibits excellent sizing performance.

[0002]

2. Description of the Related Art Aqueous emulsions are used in many industrial fields because they can supply a water-insoluble hydrophobic substance at a low viscosity and a high concentration as an aqueous liquid. In particular, a rosin-based substance is used as a hydrophobic substance. Water-based emulsions have been used as sizing agents for papermaking and modifiers for paints and inks. As a method for producing an aqueous emulsion of a rosin-based substance, a high-pressure discharge emulsification method using a solvent, a high-temperature high-pressure discharge emulsification method without using a solvent, a phase inversion emulsification method, and the like are known. As described in Japanese Patent Publication No. 54-36242, a high-pressure discharge emulsification method (solvent method) using the above-described solvent dissolves a rosin-based substance in a water-insoluble volatile organic solvent such as toluene and prepares a solution. After being in the state, a coarse aqueous emulsion of particles is prepared by pre-mixing with an emulsifying dispersant and water, and the mixture is emulsified with a high-pressure discharge emulsifier such as a homogenizer to form an emulsion of fine particles. This is a method of obtaining an aqueous emulsion by removing an organic solvent. This method has the advantage that it is not necessary to raise the temperature during emulsification because the rosin-based substance is in solution even at room temperature. In the high-temperature and high-pressure discharge emulsification method (high-temperature and high-pressure method) without using the solvent, as described in Japanese Patent Application Laid-Open No. 50-156564, a rosin-based material is heated to a temperature higher than the softening point and melted. And then premixing with an emulsifying dispersant and water to prepare an aqueous emulsion having coarse particles, and emulsifying the mixture with a high-pressure discharge emulsifier to obtain an aqueous emulsion of fine particles. The phase inversion emulsification method is disclosed in Japanese Patent Application Laid-Open No. 52-77206.
As described in Japanese Unexamined Patent Publication, while adding a suitable emulsifying dispersant and water to a heated and molten rosin-based substance while stirring, an aqueous emulsion is prepared by inverting the phase from a water-in-oil emulsion to an oil-in-water emulsion. Is a way to get

[0003]

However, the above-mentioned solvent method requires a desolvation step after the completion of emulsification, so that the productivity is low. There are occupational health and safety issues in doing so. In the high-temperature and high-pressure method, the rosin-based material is heated to a high temperature of, for example, 180 ° C. in order to lower the melt viscosity of the rosin-based material.
^It is necessary to emulsify under high pressure such as ^2, and the sealing material of the high-pressure discharge type emulsifier is severely deteriorated, and it is difficult to continuously operate for a long time. However, when the softening point becomes high, it is difficult to obtain a uniformly fine emulsion. As an improvement method thereof, Japanese Patent Application Laid-Open No. 8-117578
In Japanese Patent Application Laid-Open No. H07-155576, a high-shear rotary emulsifier (Cavitron (manufactured by CAVITRON)) is used in place of the high-pressure discharge emulsifier. A method using a type emulsifier (microfluidizer) has been proposed. However, both methods before and after the improvement,
When the rosin-based material has a high softening point, it is necessary to raise the temperature at the time of emulsification and dissolve at a higher rotation or higher pressure, and it is not only difficult to obtain an emulsion of fine and uniform particles, but also to emulsify. There is also a problem in that there is a problem in the durability of the machine, and it is difficult to perform stable continuous production, and further, there is a problem in that an emulsifying dispersant that deteriorates at the melting temperature of the rosin-based substance cannot be used. The above method does not require a large shearing force in the phase inversion emulsification method, but requires a large amount of emulsifying dispersant to obtain a fine and stable aqueous emulsion. There are problems that foaming becomes a problem when the product is used using the emulsion, and that an emulsifying dispersant that can be used in the phase inversion emulsification method, which deteriorates at the melting temperature of the rosin-based material, cannot be used.

A first object of the present invention is to provide a method for producing an aqueous emulsion of a rosin-based substance which does not adversely affect the environment or cause occupational health and safety problems as in the solvent method, and a rosin-based substance. To provide an aqueous emulsion composition and a sizing agent. A second object of the present invention is that it is difficult to obtain an emulsion of fine and uniform particles when a rosin-based substance having a particularly high softening point is used, as in a high-temperature and high-pressure method, and there is a problem in the durability of an emulsifier. An object of the present invention is to provide a method for producing an aqueous emulsion of a rosin-based substance, which does not hinder continuous production, and an aqueous emulsion composition of the rosin-based substance and a sizing agent. A third object of the present invention is to provide a method for producing an aqueous emulsion of a rosin-based substance obtained without using a large amount of an emulsifying dispersant as in a phase inversion emulsification method, an aqueous emulsion composition of the rosin-based substance and a sizing agent. To provide. A fourth object of the present invention is to provide an aqueous emulsion of a rosin-based substance such that an emulsifying dispersant which deteriorates at a high temperature due to a high temperature treatment cannot be used, such as a high temperature high pressure method or a phase inversion emulsification method. It is an object of the present invention to provide a production method, an aqueous emulsion composition of the rosin-based substance, and a sizing agent. A fifth object of the present invention is to provide a method for producing an aqueous emulsion of a rosin-based substance, which can be emulsified by a combination of a rosin-based substance and an emulsifying dispersant, which has been conventionally difficult to emulsify, and an aqueous emulsion of the rosin-based substance. It is to provide a composition and a sizing agent. A sixth object of the present invention is to provide a method for producing an aqueous emulsion of a rosin-based material, which achieves each of the above-mentioned objects, and has excellent storage stability and mechanical stability, an aqueous emulsion composition of the rosin-based material, and It is an object of the present invention to provide a papermaking sizing agent which exhibits excellent sizing performance using the same. A seventh object of the present invention is to realize the above object with high efficiency, simplicity, and low cost.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, using a high-shear type rotary emulsifier, an emulsifying dispersant and a rosin-based substance heated and melted. When performing mixing, the solid content concentration, the emulsifier content and that there is a selective effect on the mixing method, and that a fine and uniform particle emulsion can be obtained by adding a step of diluting the mixture. Have found the present invention. In the present invention, (1) an aqueous solution of an emulsifying dispersant and a rosin-based substance that has been heated and melted are mixed under high shear using a high-shear rotary emulsifying and dispersing machine, and the solid content concentration is 60 to 90% by weight; Emulsifying dispersant solids content in the
A high-concentration mixture producing step of obtaining a high-concentration mixture of 20% by weight; and a high-concentration mixture obtained through the high-concentration mixture producing step was mixed with dilution water to adjust the concentration of the total solid content to less than 60% by weight. A method for producing an aqueous emulsion of a rosin-based substance having an aqueous emulsion producing step of obtaining an aqueous emulsion, wherein the high-shear type rotary emulsifying and dispersing machine faces a stator fixed to an emulsifier body and a pair with the stator. It is possible to mix the aqueous solution of the emulsifying and dispersing agent and the rosin-based substance heated and melted under high shear using a high-shear type rotary emulsifying and dispersing machine. Continuously supplying the emulsified dispersant aqueous solution and the heat-melted rosin-based material to an emulsifying and dispersing machine, and mixing them by a high shear force generated by rotation of the rotor with respect to a stator. There is provided a method for producing an aqueous emulsion of rosin-based material. Also, the present invention
(2) An aqueous solution of an emulsifying dispersant and a rosin-based substance that has been heated and melted are mixed under high shear using a high-shear rotary emulsifying and dispersing machine, and the solid content concentration is 60 to 90% by weight, emulsification in the total solid content. A high-concentration mixture producing step of obtaining a high-concentration mixture having a dispersant solid content of 0.5 to 20% by weight, and diluting water being mixed with the high-concentration mixture obtained in the high-concentration mixture producing step to obtain a total solid content. A method for producing an aqueous emulsion of a rosin-based substance, comprising an aqueous emulsion producing step of obtaining an aqueous emulsion having a concentration adjusted to less than 60% by weight, wherein the high-shear rotary emulsifying and dispersing machine is fixed to an emulsifying machine main body; A stator having a plurality of spaced apart rings, and a rotor having a plurality of rotating rings disposed in opposition to each of the rings of the stator, and sequentially forming each pair of rings; Arrangement And each ring of the stator and the rotor has an elongated hole and / or a fine hole. The rosin-based substance melted by heating and the above-mentioned aqueous solution of the emulsifying dispersant is subjected to high shearing by using a high shearing type rotary emulsifying and dispersing machine. Mixing the aqueous solution of the emulsifying and dispersing agent and the rosin-based substance heated and melted from the center side of the stator and the rotor, so that the elongated holes and / or the pores of the respective rings of the stator and the rotor are sequentially paired. The emulsified dispersant aqueous solution and the heated and melted rosin-based substance are supplied to the gaps between the rings while flowing out, and a high shearing force is applied by rotating the respective rings of the rotor with respect to the respective rings of the stator, so that the two are separated. And a method for producing an aqueous emulsion of a rosin-based substance, which is sequentially taken out from the outer ring side in which the mixture is sequentially arranged, (3), Wherein the plurality of rings are arranged concentrically spaced apart from each other, and the plurality of rings of the rotor are sequentially and alternately arranged to face the respective rings of the stator in the above-mentioned (2). (4) The rosin-based substance according to any one of (1) to (3), wherein the aqueous solution of the emulsifying dispersant and the rosin-based substance heated and melted are supplied to the high-shear rotary emulsifier in separate lines without being mixed. (5), the rotation speed of the rotor of the high-shear rotary emulsifier is 1,000 to 25,000 times per minute, and the peripheral speed of the outermost ring of the rotor is 3 to 100 m / sec. The method for producing an aqueous emulsion of a rosin-based substance according to any one of the above (1) to (4), (6), wherein the aqueous emulsion producing step is a high-shear rotary emulsifier in a high-concentration mixture producing step. The method for producing an aqueous emulsion of a rosin-based substance according to any one of the above (1) to (5), which is a continuous dilution step of diluting with a dilution water while sequentially taking out a mixture of an aqueous solution of an emulsifying dispersant and a rosin-based substance melted by heating, (7) The method of producing an aqueous emulsion of a rosin-based substance according to the above (6) using a high-shear rotary emulsifier in the step of producing an aqueous emulsion, (8), wherein the elongated hole is a slit having a width of 0.1 to 5 mm. The method for producing an aqueous emulsion of a rosin-based substance according to any one of the above (2) to (7), wherein the pores are nozzles having a diameter of 0.1 to 5 mm; A method for producing an aqueous emulsion of a rosin-based substance according to any one of the above (1) to (8),
0), any of the above (1) to (9), wherein the average particle size of the dispersed particles of the aqueous emulsion obtained through the aqueous emulsion forming step is not larger than 0.6 μm and the particle size is not smaller than 1 μm is not larger than 1% by weight. The aqueous emulsion composition of a rosin-based substance produced by the method for producing an aqueous emulsion of a rosin-based substance, (11), (1)
The present invention provides a papermaking sizing agent containing the aqueous emulsion composition 0).

Hereinafter, the present invention will be described in detail. In the present invention, (A) rosins,
(B) α, β-unsaturated carboxylic acid-modified rosins which are reaction products of rosins with α, β-unsaturated carboxylic acid derivatives, (C) rosins, alcohols, phenols,
Rosin esters obtained by an esterification reaction with at least one member of the group consisting of epoxy compounds and the like, and (D) α, β- which is a reaction product of the rosin esters with an α, β-unsaturated carboxylic acid derivative. Examples thereof include unsaturated carboxylic acid-modified rosin esters, and mixtures of these rosin-based substances. Representative examples of the rosins (A) include gum rosin, tall oil rosin, and wood rosin, which are used alone or as a mixture of two or more, and are disproportionated to the rosins.
Rosins also include those subjected to treatments such as hydrogenation, aldehyde modification and polymerization, alone or in combination of two or more. In addition, as the α, β-unsaturated carboxylic acid-modified rosin of the above (B), the rosin contains -C２０C−C ＝ O group-containing acidic compound in an amount of 1 to 20% by weight, preferably 3 to 18% by weight. It is an addition reaction. Representative examples of the acidic compound include α, β-unsaturated carboxylic acids and acid anhydrides thereof. Specifically, fumaric acid, maleic acid, maleic anhydride, itaconic acid, citraconic acid, Examples thereof include citraconic anhydride, acrylic acid, and methacrylic acid, and the reaction can be performed by a known method.

The rosin ester (C) is a compound obtained by an esterification reaction of a rosin with at least one of the group consisting of alcohols, phenols, epoxy compounds and the like, and is a completely or partially esterified compound. Or a mixture thereof. As the alcohols, any of monohydric alcohols and dihydric or higher polyhydric alcohols can be used, and trihydric and / or tetrahydric alcohols are particularly preferable. Examples of these alcohols include glycerin, trimethylolethane, and trimethylol. Propane, 3-methylpentane-1,3,5-triol,
Examples thereof include pentaerythritol ester and diglycerin. Further, as the alcohols, two or more kinds of monohydric alcohols and dihydric or higher polyhydric alcohols can be used in combination. As the phenol, any of monohydric and dihydric or higher polyhydric phenols can be used, and polyhydric phenols are particularly preferable, and examples thereof include hydroquinone, pyrogallol, and bisphenol A. The epoxy compound is a compound having an oxirane ring, and for example, an epoxy resin such as a glycidyl ether type epoxy resin can be used. The esterification reaction between the rosin and the above compound can be performed by a known method.

The emulsifying and dispersing agents used for emulsifying and dispersing the rosin-based substance include those which form a protective colloid. Various low-molecular surfactants, high-molecular emulsifying and dispersing agents, casein, polyvinyl alcohol, Modified starch and the like can be used. In the method for producing an aqueous emulsion using the high-shear type rotary emulsifier according to the present invention, good emulsifying properties can be obtained with any emulsifying dispersant. Of the sizing agent containing the aqueous emulsion. Examples of the polymer emulsifying dispersant include a so-called amphiphilic polymer obtained by copolymerizing an anionic, cationic, or nonionic hydrophilic monomer and a hydrophobic monomer. For example, styrene
Partially or completely saponified (meth) acrylic acid copolymer, anionic or cationic monomer and (meth)
Copolymers with acrylic esters and acrylamide copolymers can be exemplified. Further, cationic polyaminopolyamide-epichlorosiderin resin, alkylenepolyamine-epichlorohydrin resin, poly (diallylamine) -epichlorohydrin resin and the like can be exemplified. These may be used alone or in combination of two or more.

The method for producing a rosin emulsion according to the present invention includes a step of producing a high-concentration mixture and a step of producing an aqueous emulsion. First, in the high-concentration mixture production step, the emulsified dispersant aqueous solution and the heat-melted rosin-based substance are mixed under high shear using a high-shear rotary emulsifier and disperser having a rotor and a stator, and the solids concentration is 60%. -90% by weight, the solid content of the emulsifying dispersant in the total solid content is 0.5-
A highly concentrated mixture which is 20% by weight is obtained. As a high-shear rotary emulsifying and dispersing machine having such a rotor and a stator,
Specific examples of the actual use of a high-concentration homogeneous mixture of an aqueous emulsifying dispersant and a molten rosin-based substance include, for example, “Dispersion Rheology and Dispersion Technology”
(Page 358, published by Shinzansha Scitech, May 20, 1991
High-speed rotation high-shear type stirring / dispersing machine, colloid mill, and the like, which are described in J. Am. Further, in the present invention, it is preferable to continuously mix the aqueous solution of the emulsifying dispersant and the rosin-based substance melted by heating, and the high-shear rotary emulsifying and dispersing machine is preferably of an in-line type. As a high-shear type rotary emulsifying and dispersing machine that can be actually preferably used, a high-speed rotation (thousands to tens of thousands of rpm) of a rotor is performed in a stationary ring (stator) close to an outer peripheral portion of a stirring blade (rotor). A structure capable of applying a shear force to the fluid by supplying the fluid to the narrow gap, wherein the rotor can rotate while maintaining a constant interval of several tens μm to several tens mm with the stator. In addition, a groove is provided in the rotor and / or the stator on a surface where the rotor and the stator are close to each other.
Micropores, long pores or comb teeth are provided, and the rotation of the rotor generates an impact force such as cavitation or pressure wave,
Some of them have a structure that can effectively apply a strong shearing force to a fluid existing in a limited area between the rotor and the stator. A plurality of the rotor / stator pairs may be present inside the emulsifying and dispersing machine. For example, a plurality of rotor / stator pairs are present on the same rotation axis in a planar or vertical shape. The multi-stage type structure in which the fluid is sequentially passed through can obtain stronger shearing force than that of the pair alone. More preferred structure as a high-shear rotary emulsifying and dispersing machine,
A stator in which a plurality of rings having different diameters provided with a plurality of penetrating pores, long pores or comb teeth are arranged on the same plane and concentrically at intervals, and an annular ring between these stator rings A ring similar to the stator is concentrically arranged on the disk-shaped substrate corresponding to the groove, and is constituted by a rotor that is engaged with the stator and rotates, and penetrates the fluid from the central portion to the outer peripheral direction through the ring of the rotor and the stator. It is a multi-stage type that passes through pores and the like and sequentially applies a shearing force to the fluid.

[0010] This is schematically shown, for example, as shown in FIG. 1, reference numeral 1 denotes a stator, and rings 3, 4, 5 having a large diameter are sequentially spaced apart from the inside of the bottom of a cylindrical body 2 having a bottom. One introduction pipe portion 6 which is arranged and fixed and is provided so as to penetrate the bottom of the frame body 2 and communicate with the innermost ring 3, is provided. Another introduction pipe 7 penetrating the bottom and communicating between these rings is provided (one introduction pipe 6 and the other introduction pipe 7 communicating with the ring 3 may be provided), and further a frame A lead-out tube 8 is provided in the cylindrical portion of the body 2 so as to communicate with a gap between the inner wall of the frame 2 and the ring 5. Reference numeral 11 denotes a rotor, and a substrate 12
Rings 13, 14, and 15 having large diameters are sequentially arranged on the inner surface of the frame so as to be fitted between the rings 3 and 4, between the rings 4 and 5, and between the ring 5 and the inner wall of the frame 2. The rotating shaft 16 is fixedly provided at the center of the outer surface of the substrate 12, and the rotating shaft 16 is rotatably inserted into a shaft hole (not shown) at the center of the frame plate 17. The rings 3, 4, 5 of the stator 1 and the rings 13, 1 of the rotor 11
4, 15 are the temperatures at which the mixture is obtained, as shown in FIG.
A ring main body 18 made of a material that can withstand impact is provided with elongated holes 19, 19,... The main body 18 has pores 20, 20,. In this case, each ring of the stator 1 and each ring of the rotor 11 may be elongated holes or pores, one may be an elongated hole, the other may be a pore, and vice versa. The width of the holes and / or the diameter of the pores may be the same or different, and each ring of the stator 1 and each ring of the rotor 11 may be different or the same ring may be used in combination. Note that the elongated hole may be a cut groove in which the entire height dimension of the ring main body is cut out.

The stator 1 and the rotor 11 are engaged with each other by fitting each other ring between the other rings, and the opening of the frame 2 is closed by a frame plate 17 by a suitable means. When the rotating shaft 16 is rotated, each ring of the rotor 11 rotates with respect to each meshed ring of the stator 1, and, for example, a rosin-based material heated and melted is introduced from one of the introduction pipes 6. When the aqueous dispersant solution is introduced from the other introduction pipe section 7,
Since each ring has elongated holes and pores as shown in FIGS. 2 and 3, they flow out through the elongated holes and pores into the gap of the meshed ring, and are mixed under the shearing force in the rotational direction. This also takes place between the outer intermeshing rings one after the other and the mixture is withdrawn from the outlet tube 8.
2 are slits having a width of 0.1 to 5 mm.
Is preferably 0.1 to 5 mm. In the high-shear type rotary emulsifying and dispersing machine described above, the rings forming each pair of the stator and the rotor are sequentially arranged in a plane, but may be arranged sequentially in a vertical shape, in which case each ring pair has the same diameter. However, in any case, the above can be applied mutatis mutandis. Commercially available high-shear rotary emulsifying and dispersing machines include an inline dispersing mixer (manufactured by YSTRAL), a Bockbolt homogenizer (manufactured by Bockbolt), a milder (manufactured by Ebara Corporation), and ONLATOR (manufactured by Ebara Corporation). Sakura Mfg.), Pentax Mixer (Alfa Laval), SUPRAT
ON (KRUPP), Cavitron (CAVITR)
ON Company).

The mixture obtained by using the above-mentioned high-shear type rotary emulsifying and dispersing machine has a solid content of 60 to 90% by weight, whereby the concentration of the emulsifying and dispersing agent in the mixture becomes high, and the The effect that the substance and the emulsifying dispersant component are easily homogenized is obtained. In addition, since the mixture of the rosin-based material and the aqueous solution of the emulsifying dispersant has high viscosity and is likely to be unevenly mixed, the emulsifying and dispersing machine needs to be of a high shear type, but excessive shearing may cause heat generation of the mixture. Therefore, a shearing force of such a degree as to be uniformly mixed is required. From this point, the rotation speed of the rotor is 1000 to 25000 rotations per minute (rpm),
The outermost peripheral speed of the rotor is preferably in the range of 3 to 100 m / sec, and the distance between the stator and the rotor is 0.05.
It is preferably from 10 to 10 mm. The interval is 0.05
If the distance is less than 2 mm, the two are in contact because the distance is small,
In addition, the resistance of rotating the rotor with the mixture interposed in the gap becomes too high, which may cause inconvenience such as excessive heat generation.On the other hand, if the gap exceeds 10 mm, a uniform mixture cannot be obtained. As a result, an emulsion having a fine particle size may not be obtained.

In the case of a conventional method for producing an aqueous emulsion using a high-pressure discharge type emulsifier or a high-shear rotary emulsifier, when a rosin-based substance and an aqueous emulsifier solution are mixed, the solid content concentration is equal to the product concentration. For example, at most 50% by weight, an oil-in-water emulsion is already formed, whereas in the method of the present invention, the rosin-based substance, the emulsifying dispersant and a small amount of water are used in the high-concentration mixture forming step. Homogeneously mixed and homogenized, at this time at least a stable oil-in-water emulsion has not been formed, and high temperatures are not necessarily required to obtain a homogeneous mixture due to mixing under high shear However, emulsifying dispersants which are susceptible to thermal deterioration or cannot be used in combination with rosin-based substances in a normal aqueous medium can be used, and are mixed with dilution water in the aqueous emulsion formation step. By being diluted to a concentration of less than 60% by weight is, for the first time fine and stable oil-in-water emulsion is produced. In the high-concentration mixture production step using a high-shear rotary emulsifying and dispersing machine, the total solid content
If the amount is less than 0% by weight, the mixture of the rosin-based substance and the aqueous solution of the emulsifier becomes uneven, and an oil-in-water emulsion having a coarse particle diameter is formed, so that an emulsion of uniform and fine particles can be obtained. On the other hand, if it exceeds 90% by weight, the aqueous solution of the emulsifying dispersant becomes too high in concentration and high in viscosity, and the mixing with the rosin-based substance may become uneven, which is not practical. The high-shear type rotary emulsifying and dispersing machine used in the high-concentration mixture producing step can be connected to a plurality of units in series, and the solid content concentration of the mixture in each high-shearing type rotary emulsifying and dispersing machine is the same, It is also possible to vary within a range of 60 to 90% by weight.

As a pre-process of the high-concentration mixture production process,
The rosin-based material is heated and melted in a tank equipped with a heating device, and has a viscosity of several hundred to several thousand centipoise (cps), and is sent to a high-shear type rotary emulsifying and dispersing machine in a high-concentration mixture production step by a metering pump. . The aqueous solution of the emulsifying dispersant is adjusted so that the solid content of the emulsifying dispersant in the mixture obtained in the high-concentration mixture producing step is 0.5 to 20% by weight of the total solid content and the solid content of the mixture is 60 to 90% by weight. After adjusting the concentration of the emulsifying dispersant, if necessary, add 10
The temperature is adjusted to about 130 ° C., and a predetermined amount is supplied to a high-shear rotary emulsifying and dispersing machine by a metering pump, and mixed with the above-mentioned molten rosin-based substance. Temperature of emulsifying dispersant aqueous solution is 10 ° C
If the temperature is lower than the above, the temperature of the molten rosin-based material mixed in the high-shear type rotary emulsifying and dispersing machine is suddenly lowered, and the rosin-based material and the dispersant aqueous solution are rapidly increased or solidified due to a rapid increase in the viscosity of the rosin-based material. May be difficult to mix uniformly. On the other hand, if the temperature of the emulsifying dispersant aqueous solution exceeds 130 ° C. and is too high, the emulsifying dispersant component may be deteriorated by thermal decomposition or the like. The temperature of the aqueous solution of the emulsifying dispersant is preferably 20 to 90 ° C., and it is not necessary to heat to the melting temperature of the rosin-based substance, and a relatively low temperature that does not cause thermal deterioration of the emulsifying dispersant is preferable. The temperature of the rosin-based material and the aqueous dispersant solution after mixing is determined by the temperature of each of the rosin-based material and the aqueous dispersant solution, the specific heat, the mixing ratio, and the mixing energy received from the high-shear rotary emulsifying and dispersing machine. The temperature is preferably 70 to 180 ° C,
If the temperature is lower than 70 ° C., dispersion in the aqueous emulsion forming step becomes insufficient, and coarse particles may be generated.
If it is higher, thermal degradation of the dispersant component or the rosin-based substance may occur. The emulsifying dispersant solid content is 0.1% of the total solid content.
If the amount is less than 5% by weight, an emulsion having a fine particle size cannot be obtained. If the amount is more than 20% by weight, the foaming property of the emulsion becomes high and the cost becomes disadvantageous.

In the present invention, the rosin-based substance in a molten state with the aqueous solution of the emulsifying dispersant supplied from the metering pump is:
In particular, when the temperature of the emulsifying dispersant aqueous solution is low, it is preferable that the aqueous solution is supplied into the high-shear rotary emulsifying and dispersing machine through separate and independent supply pipes (separate lines). As described in JP-A-8-117578, a method in which an aqueous solution of an emulsifying dispersant and a rosin-based substance in a molten state are combined before being processed by a high-speed rotary emulsifier is used. When the temperature difference between the emulsifying dispersant aqueous solution and the rosin-based material is rapidly cooled and solidified, the mixture becomes uneven at the time of merging, the emulsifying property is deteriorated, and an aqueous emulsion having a fine particle diameter cannot be obtained. Problems arise. In actual emulsification, there are optimum conditions for the supply temperature of the rosin-based substance and the aqueous solution of the emulsifier, the mixing concentration thereof, and the shearing force during the mixing, depending on the type of the rosin-based substance and the emulsifier and their combination.

In the present invention, in the step of producing the aqueous emulsion, the solid content concentration, which is the sum of the emulsifying dispersant and the rosin-based product obtained in the step of producing the high-concentration mixture, is 60 to 90% by weight.
Is diluted so that the total solids content of the concentrated mixture is less than 60%. The dilution water used for this dilution (which may contain at least one kind of a pH adjuster such as salt, acid, or alkali or a polymer substance that contributes to the stabilization of the emulsion) is subjected to temperature adjustment by a heat exchanger, It is preferable to supply at 20 to 130 ° C. If the temperature of the diluting water is too low, there arises a problem that, depending on the composition of the rosin-based substance and the aqueous solution of the emulsifier, a mixture of the two at a high concentration is partially solidified by a temperature shock or undispersed. The method of mixing the dilution water may be either a batch type or a continuous type.
In the case of the batch type, the mixture derived from the high-shear type rotary emulsifying and dispersing machine is stored in a diluting tank having the same conditions as the temperature and pressure in the high-shear type rotary emulsifying and dispersing machine in the high-concentration emulsion production step, and a predetermined amount of dilution water is added. Add and mix. In the case of a continuous type, water used for dilution is supplied by a metering pump, and a static in-line mixer (“Static mixer” (trade name of a product of Noritake Co., Ltd.)), “H
i-Mixier (trade name of product of Toray), "Skaya mixer (trade name of product of Sakura Seisakusho)", rotary emulsifier / disperser (propeller mixer, turbine mixer, dissolver), high-shear rotary emulsifier / disperser, etc. The mixture is sequentially mixed with the mixture sequentially derived from the high-shear type rotary emulsifying and dispersing machine in the high-concentration mixture producing step, but using the same high-shear type rotary emulsifying and dispersing machine used in the high-concentration mixture producing step. The emulsion obtained by performing the dilution in the aqueous emulsion production step is cooled to room temperature by a cooler and taken out.

The aqueous emulsion of the rosin-based substance obtained by such a method is fine particles having an average particle diameter of 0.6 μm or less (not larger than 0.6 μm).
Further, it is characterized in that coarse particles having a size of 1 μm or more (not smaller than 1 μm) are 1% by weight or less (at most 1% by weight) or not included. This is thought to be because the present invention has a high-concentration mixture generation step and an aqueous emulsion generation step, and further, at least in the high-concentration mixture generation step, a high-shear rotary emulsifying and dispersing machine was used, whereby a homogeneous mixture was obtained. Can be Emulsions with a fine particle size may be obtained by a conventional known emulsification method, but the emulsion often contains coarse particles of 1 μm or more, and the coarse particles are obtained by filtering the obtained aqueous emulsion. When used as a product, it may cause clogging or sediment in the product, and if a sizing agent containing these coarse particles is used in the papermaking process, it may cause a paper machine stain problem. There is. The rosin-based emulsion sizing agent for papermaking containing the aqueous emulsion obtained by the present invention reduces dirt in the papermaking system, has excellent sizing performance, and has little sediment in the product, mechanical stability. Has the feature that it is excellent.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 4, a rosin-based substance supply unit 21 capable of supplying a rosin-based substance melted in a kettle equipped with a heating device at a constant flow rate by a metering pump is mixed with an emulsifier and water. An emulsifier aqueous solution supply unit 22 that can adjust an emulsifier concentration to an arbitrary concentration and further supply an emulsifier aqueous solution adjusted to an arbitrary temperature by a heat exchanger at a constant flow rate by a metering pump.
Are supplied from each supply unit to the molten rosin-based substance and the aqueous emulsifier solution in the high-concentration mixture generation step 23, which are schematically shown in FIGS. 1 to 3 and specifically shown in, for example, FIG. The mixture is mixed with a high-shear rotary emulsifying and dispersing machine having a main part structure. In the apparatus shown in FIG. 5, the stator 31 has a nozzle 32 (diameter: 0.6 to 1.5 mm) on the entire peripheral wall, and sequentially large-diameter rings 32, 33, 34, and 35 are attached to a frame body, for example, the frame shown in FIG. The rotor 41 is fixed so as to be fixed to the body 2, while the rotors 41 are successively larger in diameter and provided with equally-spaced cut grooves (slits) (width: 0.6 mm) all around.
A ring 43 fitted between the rings 33 and 34,
A ring 4 having a nozzle (diameter: 0.6 to 1.5 mm) on the entire peripheral wall fitted between the rings 34 and 35;
1, and a rotating shaft and a frame plate are provided as shown in FIG. 1, but the stator 31 and the rotor 41 are hermetically sealed as shown in FIG. In this state, the ring 43 ~
45 faces the rings 32-35 alternately,
The rotor 41 is rotated (the number of rotations is 1000 to 10000).
rpm, average peripheral speed of the rotor ring is 3.9-40m /
Seconds), the rings 43 to 45
35, and the inlets 36 and 37 of the stator 31
Each time the molten rosin-based material and the aqueous solution of the emulsifying and dispersing agent respectively supplied from are discharged through the nozzles and slits of each of the above-mentioned rings, they are mixed under the shearing force of rotation. The mixture is withdrawn from the outlet corresponding to part 8. The number of the high-shear rotary emulsifying and dispersing machines may be one, but a plurality of the high-shearing rotary emulsifying and dispersing machines may be used. Alternatively, the emulsifier aqueous solution or the dilution water may be simultaneously passed through the inlet 37 while passing the mixture again only through the inlet 36 or the mixture again through the inlet 36. The mixture obtained in the high-concentration mixture production step has a solid content concentration of 60 to 90% by weight (solid content of the rosin-based substance and the emulsifier) and a concentration of the solid content of the emulsifying dispersant with respect to the total solid content of 3 to 6% by weight. The temperature at which the mixing is performed is from 130 to 16
The temperature of the emulsifier aqueous solution is set to 0 ° C. and the rosin-based substance melted under these conditions is continuously mixed with the emulsifier aqueous solution.

The temperature 11 obtained in the high concentration mixture production step
The mixture at 0 to 150 ° C. is subjected to an aqueous emulsion forming step 2
4 and mixed with dilution water at a temperature of 20 to 90 ° C. supplied from a dilution water supply unit 25 capable of supplying dilution water temperature-controlled by a temperature control device.
Dilute to 0-60% by weight. At this time, the configuration is different between the case where the dilution is performed continuously and the case where the dilution is performed discontinuously. However, when the dilution is performed continuously, the amount is determined by the high concentration mixture generation step 23 and the dilution water supply unit 25. Using a mixer capable of continuously mixing the mixture and the dilution water supplied at a constant flow rate by a pump, for example, a high-shear rotary emulsifying and dispersing machine used in the high-concentration mixture production step, the mixture is introduced into the inlet 36 in FIG. Dilution water is supplied to the port 37, and both are mixed and diluted. In addition, continuous mixing is performed using a static type in-line mixer according to the above. When the dilution is performed discontinuously, the mixture obtained in the high-concentration mixture generation step and the dilution water are supplied to a dilution tank equipped with a stirrer and stirred and mixed.

The above-mentioned high concentration mixture producing step 23, aqueous emulsion producing step 24, and emulsifier aqueous solution supply section 22
The step of heating the diluting water supply unit 25 is performed under pressure so that water does not boil violently when each step is performed. As shown in FIG. 4, the aqueous emulsion obtained in the aqueous emulsion production step 24 is cooled to room temperature and normal pressure in a cooling / decompression unit 26, decompressed, and taken out 27.
A more aqueous emulsion of the product is obtained. Although this aqueous emulsion is used as it is as a sizing agent, an additive may be added.

As the rosin-based material, a melting temperature of 130 to
Fumaric acid-reinforced rosin at 170 ° C, polyhydric alcohol ester of rosin, a mixture of maleic anhydride-reinforced rosin and polyhydric alcohol ester of rosin, or maleic anhydride-reinforced rosin ester, respectively, are used as emulsifying dispersants.
Styrene- (meth) acrylic acid (styrene and (meth)
A copolymer containing acrylic acid as an essential component and other vinyl monomers may be copolymerized) Anionic polymer emulsifier, acrylamide ((meth) acrylamide and anionic monomer as essential components, other vinyl Copolymers which may be copolymerized with monomers) Anionic high molecular emulsifier or acrylamide cationic high molecular emulsifier ((meth) acrylamide and cationic monomer are essential components, and other vinyl monomers are copolymerized (A copolymer that may be allowed to react).

The operation of the apparatus shown in FIG. 5 is, for example, performed by the rings 43 and 44 of the rotor 41 and the rings 3 of the stator 31.
As shown in FIG. 6 as viewed from the inlet 36 side for 3,
There is a flow due to the centrifugal force in the slits 51 of the rings 43 and 44 and the nozzle 50 of the ring 33, and the processing liquid (for example, the molten rosin-based material and The emulsified dispersant aqueous solution) receives centrifugal force due to the high speed rotation of the rotor and flows radially outward through this chamber. On the other hand, the chamber flows centrifugally due to the gap between the rotor and the slit of the stator ring and the nozzle. Is repeated, and a differential pressure ΔP is generated at this time. Further, a shear force acts on the processing liquid in the minute gap 53 between the rotor and the stator. The impact force of these flow collisions produces a strong stirring and crushing effect (partially quoted from the "Cabitron" catalog). The same applies to other rings. At this time, in the high concentration mixture generation step,
By supplying the rosin-based substance and the aqueous solution of the emulsifying dispersant separately to a high-shear rotary emulsifier, the two are contacted in a high-shearing force field, so that the mixing is performed uniformly, and the solid content of the mixed solution is also increased. By setting the concentration in the range of 60 to 90% by weight and the concentration of the solid content of the emulsifying dispersant in the total solid content in the range of 0.5 to 20% by weight, a more homogeneous mixture of both can be obtained. (Emulsion with a small number of coarse particles and overwhelmingly fine particles can be made into an emulsion with a narrow distribution.) Since water content is low, uniform mixing of rosin-based material and emulsifying dispersant is performed by limiting the amount ratio of solid content. Therefore, it is possible to use a rosin-based substance and an emulsifying dispersant which are easily deteriorated by heat, and which are difficult to be combined with a normal aqueous medium. Then, after obtaining such a uniform high concentration mixture, an aqueous emulsion producing step is provided, wherein the aqueous emulsion is diluted to obtain a solid content concentration of 60% by weight.
When the content is less than the range, an aqueous emulsion of a product having a small particle size and a narrow distribution can be obtained. It should be noted that the same applies to the apparatus shown in FIGS.

[0023]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto. Also, all parts and percentages in the examples are on a weight basis. First, materials used in Examples and Comparative Examples are manufactured as follows. Production Example 1 (Production of fumaric acid-enhanced rosin-based substance) 90 parts of fumaric acid was gradually added to 440 parts of gum rosin in a molten state at 200 ° C., and the mixture was stirred and kept at 200 ° C. for 2 hours. %) Add 470 parts of tall oil rosin, melt and stir to mix homogeneously.
Thereafter, the obtained reaction product was cooled to room temperature. The reaction product is a fumaric acid-enriched rosin to which 9% of fumaric acid has been added.

Production Example 2 (Production of Polyhydric Alcohol Ester of Rosin Substance) In a 1-liter flask equipped with a stirrer, a thermometer, a nitrogen inlet tube, a water separator and a condenser, 600 parts of gum rosin having an acid value of 170 were added. Prepare 55 parts of glycerin and add 1 at 270 ° C.
The esterification reaction was performed for 5 hours to obtain a reaction product of a polyhydric alcohol ester of a rosin substance.

Production Example 3 (Production of a mixture of maleic anhydride-reinforced rosin and rosin ester) 7 parts of maleic anhydride was added to 43 parts of gum rosin in a molten state at 200 ° C., and the mixture was stirred and kept at 200 ° C. for 2 hours.
50 parts of the rosin ester of Production Example 2 was added and stirred and mixed in a molten state to obtain a 1: 1 weight ratio mixture of maleic anhydride-reinforced rosin and rosin ester.

Production Example 4 (Production of maleic anhydride-reinforced rosin ester) 93 parts of the rosin ester glycerin ester obtained in Production Example 2 was heated to 200 ° C. and melted to obtain maleic anhydride 7
The resulting mixture was heated and maintained at 200 ° C. for 3 hours to obtain a maleic anhydride-enhanced rosin ester as a maleic anhydride reaction product.

Production Example 5 (Production of styrene-methacrylic acid-based anionic polymer emulsifying dispersant) A 1-liter pressure-resistant flask equipped with a stirrer, a thermometer and a nitrogen gas inlet tube was charged with 50 parts of styrene and 3 parts of methacrylic acid.
0 parts, acrylic acid 10 parts, lauryl acrylate 10 parts,
Stir and mix 1 part of ammonium persulfate and 225 parts of water,
Heated at 150 ° C. for 2 hours. Then cool to 60 ° C,
By slowly dropping 35.5 parts of 48.5% sodium hydroxide, stirring for 30 minutes, and then cooling to room temperature,
A styrene-methacrylic acid-based anionic polymer-based emulsifying dispersant as a polymer dispersion having a solid content of 30% was obtained.

Production Example 6 (Production of Cationic Polymer Emulsifier and Dispersant for Examples) According to the method for producing cationic poly (meth) acrylamide having a hydrophobic group in the examples of JP-A-3-227481, Thus, a polymer emulsifying dispersant was produced. In a 1-liter four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube, 31.4 parts of dimethylaminoethyl methacrylate, 85.3 parts of a 50% aqueous acrylamide solution, 20.8 parts of styrene, 100.6 parts of ion-exchanged water, 143.
3 parts and 0.6 part of n-dodecyl mercaptan were charged and 2 parts
The pH was adjusted to 4.5 with a 0% acetic acid aqueous solution. The mixture was heated to 60 ° C. under a nitrogen gas atmosphere while stirring. 2.3 parts of a 5% aqueous solution of ammonium persulfate was added as a polymerization initiator, the temperature was raised to 80 ° C., and the temperature was maintained for 1.5 hours. Then, 0.7 part of a 5% aqueous solution of ammonium persulfate was added. After maintaining at the same temperature for an additional hour, isopropyl alcohol was distilled off, water was further added, and the solid content concentration was 30.
% Of a polymer solution was obtained.

Production Example 7 (Production of anionic polymer-based emulsifying and dispersing agent for Examples) Normal butyl methacrylate was placed in a 1-liter four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube. 19 parts, 50% acrylamide aqueous solution 9
6 parts, 80% acrylic acid aqueous solution 8 parts, ion exchange water 83
, 88 parts of isopropyl alcohol and 0.9 part of n-dodecyl mercaptan, and the mixture was heated to 60 ° C. under a nitrogen gas atmosphere while stirring and mixing. 0.14 parts of azobisisobutyronitrile was added as a polymerization initiator, the temperature was raised to 80 ° C., and the temperature was maintained for 2 hours. Then, ion-exchanged water was added, and then isopropyl alcohol was distilled off. An anionic polymer emulsifier / dispersant as a polymer solution was obtained.

Example 1 According to the process shown in FIG. 4, in the rosin-based material supply section 21, the fumaric acid-reinforced rosin obtained in Production Example 1 is melted at 150 ° C., and the melted fumaric acid-reinforced rosin is kept at 150 ° C. I do. In the emulsifier aqueous solution supply section 22, the anionic polymer-based emulsifier / dispersant obtained in Production Example 5 is continuously diluted with water in a line, and the amount of the emulsifier / dispersant in the high-concentration mixture production step and the solid content of the mixture are reduced. After the solid concentration is adjusted so that the partial concentration becomes a predetermined value, heating is performed by a heating device so that the temperature becomes 80 ° C. Next, in the high-concentration mixture production step 23, Cavitron CD-1010 is used as a high-shear rotary emulsifier.
D-1010 is a stator and rotor in which both rings of the stator and the rotor shown in FIG. 5 have the same shape as the slit of FIG. Operation is performed at a peripheral speed of 3.9 m / sec and a rotor rotation speed of 1000 rpm. Under such an operating condition, the fumaric acid fortification in the molten state maintained at 150 ° C. by the metering pump from the rosin-based substance supply unit 21 to the respective inlets corresponding to the inlet 36 and the inlet 37 shown in FIG. While supplying rosin, the emulsifier dispersant was adjusted to a predetermined concentration from the emulsifier aqueous solution supply unit 22 so that the emulsified dispersant in the high-concentration mixture generation step was 5% and the solid content of the mixture was 76%, and the mixture was heated to 80 ° C. An aqueous emulsifier solution is supplied by a metering pump, and the two are mixed in the emulsifier based on the above-described action, and a mixture of the fumaric acid-reinforced rosin and the aqueous emulsifier solution is sequentially taken out from an outlet corresponding to the inlet tube portion 8 in FIG. The mixture thus obtained has a solid content concentration (total of the solid content of the emulsifying dispersant and the fumaric acid-enriched rosin) of 7
6%, temperature 110 ° C. Next, this mixture is diluted in the aqueous emulsion producing step 25. Here, the mixture obtained at the high-concentration mixture producing step 23 (temperature 1
(10 ° C.), 585 g of 90 ° C. water prepared in advance in the dilution water supply unit 24 is supplied, and the mixture is stirred and mixed for 30 minutes. Then, cool under stirring,
An aqueous emulsion of a rosin-based material was obtained as a product.
The obtained aqueous emulsion had a solid content of 35%, the solid content of the emulsifying dispersant in the total solid content was 5%, and the average particle size was 0.1%.
It was 45 μm.

Example 2 In Example 1, the solid content of the emulsifying dispersant was 4% of the total solid content.
%, The solids concentration of the mixture obtained through the high-concentration mixture generation step is 72%, and the solids concentration of the emulsion obtained through the aqueous emulsion generation step is 40%, and the outermost ring of the rotor of the Cavitron CD-1010. Peripheral speed of 23
m / sec, the number of revolutions of the rotor is set to 6000 rpm, and in the aqueous emulsion production step, a static mixer (a mixer in which each of the two liquids to be mixed is supplied at a constant flow rate and mixed in a line) is used to obtain a high concentration. A mixture which is sequentially taken out in a mixture producing step;
A water-based emulsion of a rosin-based substance having an average particle diameter of 0.40 μm was obtained in the same manner except that continuous mixing in which water was supplied at a constant flow rate and mixed and dispersed was performed.

Example 3 In Example 2, the solid content of the emulsifying dispersant was 3% of the total solid content.
%, The solid content of the mixture obtained through the high-concentration mixture generation step is 67%, and the solid content of the emulsion obtained through the aqueous emulsion generation step is 50%, and the stator and rotor of the Cavitron CD-1010 are respectively Was changed to a nozzle type having a hole with a diameter of 0.6 mm on the entire circumference, and the peripheral speed of the outermost ring of the rotor was 39 m /
Secondly, the number of revolutions of the rotor was set to 10000 rpm, and further in the aqueous emulsion forming step,
Using the Cavitron CD-1010 having the same configuration as that used in the above, continuous mixing was performed at a peripheral speed of the outermost ring of the rotor of 23 m / sec and a rotation speed of the rotor of 6000 rpm. An aqueous emulsion of a rosin-based substance having an average particle size of 0.25 μm was obtained in the same manner as in the above.

Example 4 In Example 3, the temperature of the aqueous emulsifier solution in the step of producing a high-concentration mixture was set to 120 ° C., and two liquids of the emulsifier aqueous solution and the molten rosin-based material were mixed into one liquid in the same tube. An aqueous emulsion of a rosin-based material having an average particle diameter of 0.40 μm was obtained in the same manner except that the mixture was supplied to Cavitron CD-1010.

Example 5 The same procedure as in Example 3 was carried out except that a nozzle type in which each ring had a pore diameter of 1.5 mm was used as the stator and rotor of the Cavitron CD-1010 used in the high-concentration mixture production step. Thus, an aqueous emulsion of a rosin-based substance having an average particle diameter of 0.35 μm was obtained.

Example 6 In Example 3, two Cavitron CD-1010s were connected in series in the step of producing a high-concentration emulsion.
The mixed liquid obtained sequentially from the second unit is introduced into the inlet 3 of FIG.
6, the solid content of the mixture obtained from the second unit was 61%, the temperature at the time of supply of the aqueous solution of the emulsifying dispersant was 40 ° C., and both of the two units had the outermost ring of the rotor. An aqueous emulsion of a rosin-based material having an average particle diameter of 0.20 μm was obtained in the same manner except that the peripheral speed was 31 m / sec and the number of revolutions of the rotor was 8000 rpm.

Example 7 In Example 3, the maleic anhydride-enriched rosin and rosin ester mixture obtained in Production Example 3 was used as the rosin-based substance, and the cationic polymer obtained in Production Example 6 was used as an emulsifying dispersant. Using an emulsifying dispersant, the temperature at the time of supplying the rosin-based substance was 140 ° C., the temperature at the time of supplying the aqueous solution of the emulsifying dispersant was 30 ° C., the temperature at the time of supplying the dilution water was 25 ° C. With the exception that 4% of the total solids, the solids concentration of the mixture obtained through the high-concentration mixture forming step was 82%, and the solids concentration of the emulsion obtained through the aqueous emulsion forming step were 45%. Average particle size 0.28
An aqueous emulsion of a rosin-based material of μm was obtained.

Example 8 In Example 3, the maleic anhydride-reinforced rosin and rosin ester mixture obtained in Production Example 3 was used as the rosin-based substance, and the anionic polymer obtained in Production Example 7 was used as an emulsifying dispersant. Using an emulsifying dispersant, the temperature at the time of supplying the rosin-based substance was 140 ° C., the temperature at the time of supplying the aqueous solution of the emulsifying dispersant was 40 ° C., and the temperature at the time of supplying the diluting water was 60 ° C. Is 5% of the total solids, the solids concentration of the mixture obtained through the high-concentration mixture generation step is 89%, the peripheral speed of the outermost ring of the rotor of the Cavitron CD-1010 in the same step is 31 m / sec, The rotation speed is set to 8000 rpm,
The average particle system was similarly adjusted except that the solid content concentration of the mixture obtained through the aqueous emulsion formation step was 45%.
An aqueous emulsion of a 25 μm rosin-based substance was obtained.

Example 9 In Example 3, the maleic anhydride-reinforced rosin ester obtained in Production Example 4 was used as the rosin-based substance, and the anionic polymer emulsifying dispersant obtained in Production Example 5 was used as an emulsifying dispersant. And the temperature at the time of supply of the rosin-based material is 160
C., the temperature at the time of supplying the aqueous solution of the emulsifying dispersant is 60 ° C., the temperature at the time of supplying the diluting water is 80 ° C., and the solid content of the emulsifying dispersant is 6% of the total solid content. An aqueous emulsion of a rosin-based substance having an average particle diameter of 0.23 μm was prepared in the same manner except that the solid content concentration of the mixed solution obtained was 85%, and the solid content concentration of the mixed solution obtained through the aqueous emulsion forming step was 50%. Obtained.

Example 10 In Example 4, the high-shear rotary emulsifier used in the high-concentration mixture production step was replaced with a Pockbolt 100 (manufactured by Bockbolt), and the peripheral speed of the rotor was 19 m / sec. An aqueous emulsion of a rosin-based substance having an average particle diameter of 0.42 μm was obtained in the same manner except that the number of revolutions was set to 3000 rpm and the solid content concentration of the mixture obtained in the high-concentration mixture generation step was set to 72%.

COMPARATIVE EXAMPLE 1 In Example 3, by setting the solid concentration in the high-concentration mixture production step to 50%, an aqueous dispersion passed through the high-concentration mixture production step was obtained, and the aqueous emulsion production step was not performed. Except for the above, an aqueous emulsion of a rosin-based substance having an average particle size of 1.8 μm was obtained in the same manner.

Comparative Example 2 The procedure of Example 3 was repeated, except that the solid content of the emulsion in the aqueous emulsion forming step was changed to 62%, but the emulsion was solidified in the cooling / decompression section.
An aqueous emulsion of a rosin-based material could not be obtained because the production line was blocked.

Comparative Example 3 The same procedure as in Example 3 was carried out except that the solid content concentration of the mixture in the high-concentration mixture producing step was 55%, and the solid concentration of the emulsion obtained through the aqueous emulsion producing step was 50%. Thus, an aqueous emulsion of a rosin-based substance having an average particle diameter of 1.5 μm was obtained.

Comparative Example 4 In Example 7, the temperature at the time of supplying the rosin-based material was changed to 16
0 ° C., the temperature at the time of supplying the aqueous solution of the emulsifying dispersant was 150 ° C., the solid content of the emulsifying dispersant was 5% of the total solid content, and the solid content concentration of the dispersion in the high concentration mixture producing step was 45%. In the production process, a Gaulin homogenizer, which is a high-pressure discharge emulsifier, is used.
/ Cm ² , except that the treatment was carried out under a pressure of 0.45 μm, and a dispersion of a rosin-based substance containing 1.3% of an average particle diameter of 0.45 μm and a particle diameter of 1 μm or more was obtained.

Comparative Example 5 In Example 9, the temperature at the time of supplying the rosin-based material was changed to 18
0 ° C., the temperature at the time of supplying the emulsifying dispersant aqueous solution is 160 ° C., using a Gaulin homogenizer, which is a high-pressure discharge type emulsifying machine, in the aqueous emulsion producing step and the same as the solid concentration in the high concentration mixture (preliminary dispersion) producing step. The same operation was carried out except that the treatment was carried out at a solid concentration of 50% by applying a pressure of 600 kgf / cm ² .
An aqueous emulsion of a rosin-based material containing 40 μm and a particle diameter of 1 μm or more containing 1.1% was obtained. However, the particle diameter became larger due to the deterioration of the seal portion of the Gorin homogenizer with the lapse of the processing time. , Processing start 2
After a lapse of time, an aqueous emulsion of a rosin-based substance containing an average particle diameter of 0.65 μm and a particle diameter of 1 μm or more containing 7% was obtained.

Comparative Example 6 The rosin-based material obtained in Production Example 3 was heated and melted at about 150 ° C. using a pressure-resistant flask with stirring blades capable of heating and cooling, and obtained in Production Example 6 while stirring. The obtained cationic polymer emulsifying and dispersing agent was added to and mixed with 7% of the total solid content to obtain a water-in-oil emulsion. Under stirring, hot water was gradually added to cause phase inversion to obtain an oil-in-water emulsion. Hot water was further quickly added and mixed to form a stable oil-in-water emulsion, followed by cooling to room temperature. In this way, an aqueous emulsion of a rosin-based substance having an average particle diameter of 0.48 μm and a particle diameter of 1 μm or more contained 1.5% was obtained.

Comparative Example 7 The rosin-based substance obtained in Production Example 4 was heated and melted at about 160 ° C. using a pressure-resistant flask with stirring blades capable of heating and cooling, and obtained in Production Example 5 while stirring. The obtained anionic polymer emulsifying and dispersing agent was added and mixed so as to be 10% of the total solid content to obtain a water-in-oil emulsion. Under stirring, hot water was gradually added to cause phase inversion to obtain an oil-in-water emulsion. Hot water was further quickly added and mixed to form a stable oil-in-water emulsion, followed by cooling to room temperature. In this way, an aqueous emulsion of a rosin-based substance containing 0.73 μm in average particle diameter and 10% in particle diameter of 1 μm or more was obtained. The main production conditions of the above Examples and Comparative Examples are summarized in Tables 1 and 2, and these Examples,
Tables 1 and 2 collectively show the particle sizes of the obtained aqueous emulsions described in each of the comparative examples.

[0047]

[Table 1]

[0048]

[Table 2]

From the results of the examples and comparative examples, in the examples, the ratio of particles having a particle diameter of 0.2 to 0.45 μm, 1 μm or more (at least 1 μm) can be reduced to 0, which is within the range of the same effect. In contrast, in Comparative Example 1, the solid content concentration in the “high-concentration mixture generation step” is too low. It has been formed, and this step has become the "aqueous emulsion generation step" without going through the "high concentration mixture generation step", and the rosin-based material and the emulsifier aqueous solution are not uniformly mixed. This indicates that dispersed particles cannot be obtained. In Comparative Example 2, the solid content concentration in the “aqueous emulsion generation step” was too high, and the solidification was performed. In Comparative Example 3, the solid content concentration in the “aqueous emulsion generation step” was appropriate. " Becomes the same results as Comparative Example 1 for the solid concentration is too low in concentration mixture forming step ",
Comparative Example 4 corresponds to the case where the product of Example 7 was emulsified by a high-temperature and high-pressure emulsification method. The “high-concentration mixture generation step” was defined as a “preliminary dispersion generation step”, and the “aqueous emulsion generation step” was determined under high-pressure discharge. The emulsification was carried out as a “microparticulation step” using a liquid emulsifier, but only an emulsion having a larger particle diameter than that of Example 7 was obtained. Comparative Example 5
In Example 9, Example 9 was emulsified by the same high-temperature and high-pressure emulsification method as in Comparative Example 4. However, as compared with Example 9, not only those having a large particle size were obtained, but also the emulsifier This indicates that the seal portion deteriorates, and that stable production is difficult. Comparative Examples 6 and 7 were each a combination of the rosin-based substance and the emulsifying dispersant of Examples 7 and 9, and emulsified by the phase inversion emulsification method using a large amount of the emulsifying dispersant. However, only an emulsion having a large particle system was obtained from each of the examples, and in particular, Comparative Example 7
In the case of, the tendency was remarkable. The aqueous emulsion of the rosin-based material of the examples can be used regardless of the type of the emulsifying dispersant and the type of the rosin-based material. By these methods, an aqueous emulsion of a rosin-based substance having higher productivity and a dispersion having a fine particle diameter can be obtained than in the conventional method for obtaining an aqueous emulsion of a rosin-based substance. Table 2 shows the results of a size effect test, a mechanical stability test, and a static stability test performed using the aqueous emulsion compositions of the rosin-based substances obtained in the above Examples and Comparative Examples. The test conditions are as follows.

(Size Effect Test 1) A bleached kraft pulp (mixed pulp having a pulp ratio of 1 to 9 for softwood broadleaf trees) having a hardness of 100 p such that the pulp concentration becomes 2.5%.
pm of dilution water, 400 ml using a beater
Beated to Canadian Standard Freeness. Next, 1.2 liters of the obtained pulp slurry was weighed into a disintegrator, and bansulfate was added to the pulp at 1.5% with stirring, and then the rosin-based material obtained from each of the above Examples and Comparative Examples Was added separately to 0.2% of pulp. Then, the obtained pulp slurry was diluted to a concentration of 0.25% with diluting water having a pH of 4.5, and cationic polyacrylamide (paper strength enhancer DS410, manufactured by PMC Co., Ltd.) was used as a fixing agent. 0.05
%, And the papermaking pH was adjusted with a Noble & Wood paper machine.
5 and drying of the obtained wet paper was performed using a drum dryer under the conditions of 100 ° C. and 100 seconds.
Test papers of the above Examples and Comparative Examples having m ² were obtained.
Each of the obtained test papers was conditioned for 24 hours in a constant temperature and constant humidity (20 ° C., 65% relative humidity) environment, and the size was measured by the Stechich method. This sizing method is described in Production Example 1.
This was performed only for aqueous emulsions of rosin-based substances using the rosin-based substances obtained in (Examples 1 to 6, 10 and Comparative Examples 1 to 3).

(Size Effect Test 2) 1.2 liters of pulp slurry obtained by beating under the same conditions as in the above size effect test 1 was weighed into a disintegrator, and stirred with light calcium carbonate (Okutama Kogyo Co., Ltd.). Tamapearl 121S) was added to pulp at 3.0%, sulphate bread soil was added to pulp at 1.0%, and the paper strength enhancer DS410 was added at 0.2% to pulp. The obtained aqueous emulsion of the rosin-based material was added separately in an amount of 0.4% based on pulp. Then, the obtained pulp slurry was diluted to a concentration of 0.25% with a dilution water of pH 8, and the light calcium carbonate was further added to the pulp by 5%, and the high molecular weight cationic polyacryl abad as a retention agent was added to the pulp by 0.01%. The resulting wet paper was dried with a drum dryer at a paper making pH of 8 using a Noble and Wood paper machine.
The test was performed under the conditions of 00 ° C. and 80 seconds to obtain test papers of the above Examples and Comparative Examples having a basis weight of 65 g / m ² . Each of the obtained test papers is kept at a constant temperature and humidity (20 ° C., relative humidity 65%).
After conditioning for 24 hours in the environment, the size was measured by the Stechich method. This sizing degree measurement method was carried out only for aqueous emulsions of rosin-based substances using the rosin-based substances obtained in Production Examples 3 and 4 (Examples 7 to 9 and Comparative Examples 4 to 7).

(Stability stability test) 100 ml of each of the rosin-based emulsion compositions of the above Examples and Comparative Examples were separately placed in a test tube having a length of 30 cm and an inner diameter of 2.1 cm.
After standing for 2 months, the height (mm) of the precipitate settled on the bottom was measured.

(Mechanical Stability Test) 50 g of the rosin-based emulsion composition of each of the above Examples and Comparative Examples was placed in a cup, and the temperature was 25 ° C., the load was 25 kg, and the number of revolutions was 80.
A Marlon stability test was performed at 0 rpm for 10 minutes.
The aggregate formed in each cup was filtered through a 325 mesh wire net, and the amount of precipitation with respect to the total solid content in each cup was measured and expressed as a percentage.

[0054]

[Table 3]

From the above results, when the aqueous emulsion composition of the rosin-based substance of the example was used as a sizing agent, both the size effect test and the stability test of the sizing agent were superior to those of the comparative example, It turns out that it is excellent in emulsifying property.

[0056]

According to the present invention, a rosin-based resin having a particularly high softening point, such as a high-temperature high-pressure method, does not adversely affect the environment as in the solvent method or has a problem in occupational safety and health. When a substance is used, it is difficult to obtain an emulsion of fine and uniform particles, there is a problem with the durability of the emulsifier, and there is no problem in performing continuous production. Conventional emulsification is difficult without the use of a large amount of emulsifying dispersant, as in the case of the high-temperature high-pressure method or the phase inversion emulsifying method. The emulsification is also possible by the combination of the rosin-based substance and the emulsifying dispersant, which has excellent storage stability and mechanical stability,
Provided are a method for producing an aqueous emulsion of a rosin-based substance, which can be realized with high efficiency, simple, and low cost, an aqueous emulsion composition of the rosin-based substance, and a papermaking sizing agent using the same and exhibiting excellent sizing performance. be able to.

[Brief description of the drawings]

FIG. 1 is an exploded explanatory view in which a part of a schematic view of an example of a high-shear type rotary emulsifying and dispersing machine according to the present invention is partially cut away.

FIG. 2 is a perspective view of a main part of an example of the rotor and the stator.

FIG. 3 is a perspective view of a main part of another example of the rotor and the stator.

FIG. 4 is a process explanatory view of one embodiment of the production method of the present invention.

FIG. 5 is an exploded perspective view of a high-shear rotary emulsifying and dispersing machine used in one step, in which a main part is partially cut away.

FIG. 6 is an explanatory view of the principle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 31 Stator 11, 41 Rotor 3-5, 32-35 Stator ring 13-15, 42-45 Rotor ring 19, 51 Slit 20, 50 Pores, nozzle 21 Rosin-based substance supply part 22 Emulsifier aqueous solution supply part 23 High concentration mixture generation step 24 Aqueous emulsion generation step 25 Dilution water supply unit

Continued on the front page (72) Inventor Katsunori Nakamura 17-2, Yawata Kaigan-dori, Ichihara-shi, Chiba PMC Japan Co., Ltd. (72) Inventor Koji Ota 17-2, Yawata-kaigan-dori, Ichihara-shi, Chiba (56) References JP-A-8-117578 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D21H 11/00-27/42 B01F 3/08

Claims (11)

(57) [Claims] An aqueous solution of an emulsifying dispersant and a rosin-based substance that has been heated and melted are mixed under high shear using a high-shear rotary emulsifying and dispersing machine, and the solid content concentration is 60 to 90% by weight. A high-concentration mixture producing step for obtaining a high-concentration mixture having an emulsifying dispersant solid content of 0.5 to 20% by weight; and mixing the high-concentration mixture obtained through the high-concentration mixture producing step with dilution water. A method for producing an aqueous emulsion of a rosin-based substance having an aqueous emulsion producing step of obtaining an aqueous emulsion having a total solid content adjusted to less than 60% by weight, wherein the high-shear rotary emulsifying and dispersing machine is fixed to an emulsifying machine main body. And a rotating rotor disposed opposite to the stator in a pair. The rosin-based material melted by heating and melting the emulsifying dispersant aqueous solution is subjected to high shearing by using a high shearing type rotary emulsifying and dispersing machine. Mix below That is, the high-shear type rotary emulsifying and dispersing machine is continuously supplied with the aqueous solution of the emulsifying dispersant and the fusible rosin-based material by heating, and mixing the two by a high shearing force generated by rotation of the rotor with respect to the stator. A method for producing an aqueous emulsion of a rosin-based substance. 2. An aqueous solution of an emulsifying dispersant and a rosin-based substance heated and melted are mixed under high shear using a high-shear rotary emulsifying and dispersing machine, and the solid content concentration is 60 to 90% by weight. A high-concentration mixture producing step of obtaining a high-concentration mixture having an emulsifying dispersant solid content of 0.5 to 20% by weight, and mixing the high-concentration mixture obtained in the high-concentration mixture producing step with water to obtain a total solid content. A method for producing an aqueous emulsion of a rosin-based substance, comprising an aqueous emulsion producing step of obtaining an aqueous emulsion having a concentration adjusted to less than 60% by weight, wherein the high-shear rotary emulsifying and dispersing machine is fixed to an emulsifying machine main body; A stator having a plurality of spaced apart rings, and a rotor having a plurality of rotating rings disposed in opposition to each of the rings of the stator, and sequentially forming each pair of rings; Arrangement And the rings of the stator and the rotor each have an elongated hole and / or a fine hole, and the rosin-based substance melted by heating with the aqueous solution of the emulsifying dispersant is subjected to high shearing by using a high shearing type rotary emulsifying and dispersing machine. Mixing underneath means that the aqueous solution of the emulsifying dispersant and the rosin-based substance heated and melted are supplied from the center side of the stator and the rotor, and the elongated holes and / or the narrow holes of the respective rings of the stator and the rotor are sequentially paired. Supplying these emulsified dispersant aqueous solution and the heated and melted rosin-based material to the gap between the rings while flowing out from the holes, applying high shearing force by rotating each ring of the rotor with respect to each ring of the stator. A method for producing an aqueous emulsion of a rosin-based substance in which both are mixed and the mixture is sequentially taken out from an outer ring side in which the mixture is sequentially arranged. 3. The rosin of claim 2, wherein the plurality of rings of the stator are concentrically spaced apart and the plurality of rings of the rotor are sequentially and alternately opposed to the respective rings of the stator. A method for producing an aqueous emulsion of a base substance. 4. The rosin-based substance according to claim 1, wherein the aqueous solution of the emulsifying dispersant and the rosin-based substance heated and melted are supplied to the high-shear rotary emulsifier in separate lines without being mixed. A method for producing an aqueous emulsion. 5. The high-shear rotary emulsifier according to claim 1, wherein the number of revolutions of the rotor is 1,000 to 25,000 times per minute, and the peripheral speed of the outermost ring of the rotor is 3 to 100 m / sec. A method for producing an aqueous emulsion of a rosin-based substance according to any one of the above. 6. The aqueous emulsion production step is a continuous dilution step in which a mixture of an aqueous solution of an emulsifying dispersant and a rosin-based substance melted by heating is sequentially taken out from a high-shear rotary emulsifier in a high-concentration mixture production step and diluted with dilution water. A method for producing an aqueous emulsion of a rosin-based substance according to any one of claims 1 to 5. 7. The method for producing an aqueous emulsion of a rosin-based substance according to claim 6, wherein the aqueous emulsion producing step uses a high-shear rotary emulsifier. 8. The aqueous emulsion of a rosin-based substance according to claim 2, wherein the elongated hole is a slit having a width of 0.1 to 5 mm, and the fine hole is a nozzle having a diameter of 0.1 to 5 mm. Production method. 9. The method according to claim 1, wherein the emulsifying dispersant is a polymer emulsifying dispersant. 10. The dispersion particle of the aqueous emulsion obtained through the aqueous emulsion production step has an average particle size of 0.6 μm.
An aqueous emulsion composition of a rosin-based substance produced by the method for producing an aqueous emulsion of a rosin-based substance according to any one of claims 1 to 9, wherein particles having a size not larger than m and not smaller than 1 µm are not larger than 1% by weight. 11. A papermaking sizing agent comprising the aqueous emulsion composition according to claim 10.