JPH03199488A - Production of rosin-based emulsion size - Google Patents

Abstract

PURPOSE:To obtain the subject size in which size particles are extremely, finely and stably dispersed and good in sizing effects by using respective specific substances as a rosin-based substance and dispersing agent in a phase inversion method. CONSTITUTION:The objective size obtained by using a mixture of a phenolic resin with a reinforcing rosin as (A) a rosin-based substance in a molten state and an alkali neutralized salt composed of a styrene-based monomer.acrylic acid ester.acrylic acid.methacrylic acid as a dispersing agent in mixing the component (A) with (B) water containing the aforementioned dispersing agent, forming a dispersion containing the component (A) as a continuous phase and the water as a disperse phase, adding water thereto, inverting the phase and affording an aqueous emulsion in which the water is the continuous phase and the component (A) is the disperse phase. Furthermore, the above-mentioned neutralized salt is used in an amount within the range of 5-20wt.% based on the component (A).

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a method for producing a rosin-based aqueous emulsion useful as a sizing agent for paper manufacturing, and more specifically, relates to a method for producing a rosin-based emulsion sizing agent by a phase inversion method. Relates to improvements in the method of manufacturing.

[Prior Art] In recent years, the paper manufacturing industry has been aiming to recover and reuse papermaking wastewater as much as possible from the viewpoints of stricter regulations regarding factory wastewater, reduction of water costs, and the like. In this case, the quality of papermaking water is inevitably degraded, and it is extremely difficult to impart a sufficient sizing effect to the bottom paper using saponified rosin sizing agents that have been widely used in the past. For this reason, emulsion-type rosin-based sizing agents have been in the spotlight in recent years.

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

However, the rosin-based emulsion sizing agent produced by the conventional inversion method cannot produce homogeneous and fine rosin emulsion particles unless a surfactant-based dispersant is used in a relatively large amount of 4 to 8% by weight based on the rosin-based material. can't get it. However, when such a rosin-based emulsion sizing agent is used in papermaking, foaming occurs in the papermaking system, which not only causes pinholes and the like in the paper but also causes pitch trouble.

[Means for Solving the Problems] In order to solve the above problems, the present inventors have discovered that it is not possible to obtain homogeneous and fine rosin-based emulsion particles even if the amount of surfactant-based dispersant used is reduced. As a result of repeated research on the rosin-based materials that can be produced, we decided to use a mixture of phenolic resin and reinforced rosin as the rosin-based material for the inversion method, and to use specific agents to disperse this rosin-based material as described below. We have discovered that by using an alkali-neutralized salt of a quaternary copolymer, a homogeneous rosin-based emulsion with fine dispersoid particles can be obtained without using any surfactant-based dispersant.

That is, the method for producing a rosin-based emulsion sizing agent according to the present invention involves mixing a molten rosin-based material and water containing a dispersant to form a dispersion in which the rosin-based material is a continuous phase and water is a dispersed phase. A method for producing a rosin-based emulsion sizing agent in which 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, then adding water to the dispersion and inverting the phase. , a mixture of a phenolic resin and a reinforced rosin is used as the rosin substance, and a quaternary copolymer consisting of a styrene monomer, an acrylic ester, acrylic acid, and methacrylic acid is neutralized with an alkali as the dispersant. It is characterized by the use of salt.

The amount of the phenolic resin mixed with the reinforced rosin is in the range of 5 to 20% of the weight of the reinforced rosin.

In the method of the present invention, the phenolic resin refers to an alkylphenol formalin addition condensate, a phenol-modified petroleum resin, etc., and its molecular weight can be 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 performing a condensation reaction of methylol groups to increase the amount. In addition, phenol-modified petroleum resin is produced by reacting petroleum resin with phenol or a phenol compound, or by producing petroleum resin in the presence of phenol or a phenol compound. The molecular weight can be adjusted by adjusting the molar ratio of reactants and the amount of catalyst added.

As the reinforced rosin, a rosin such as gum rosin or tall oil rosin reacted with an α,β-unsaturated polybasic acid by a known method can be used. Examples of α,β-unsaturated polybasic acids include fumaric acid, maleic anhydride, itaconic acid, acrylic acid, and methacrylic acid, but addition of fumaric acid is most preferable, and the amount of addition is 6 to 15%. Preferably it is in the range of 9 to 3%. In the present invention, if desired, a part of the reinforced rosin can be replaced with a phenol resin-modified reinforced rosin.

In the present invention, an alkali neutralized salt of a quaternary copolymer consisting of a styrene monomer, an acrylic ester, acrylic acid, and methacrylic acid is used as the agent for dispersing the above-mentioned rosin-based substance in an aqueous medium. Here, the styrene monomers include styrene, vinyltoluene, α-
Examples include β-methylstyrene and isopropenyltoluene, and these can be used alone or in combination of two or more. Among them, the use of styrene is most preferred.

In addition, examples of acrylic esters include compounds represented by the general formula %, where R1 is hydrogen or a methyl group, and R2 is a straight or branched alkyl group or cycloalkyl group having 1 to 8 carbon atoms. But R2 has 4 carbons
Preference is given to using compounds which are ˜8 alkyl groups.

The weight percent of each monomer constituting the above-mentioned quaternary copolymer is styrene monomer 50-70%, acrylic ester LO-30%, acrylic acid 10-t5%, methacrylic acid LO-(within a range of 5%). It is in.

If the amount of acrylic ester is less than 10% or more than 30%, the resulting copolymer cannot be expected to have sufficient dispersibility for rosin-based substances. Further, the ratio of acrylic acid to methacrylic acid is preferably in the range of 4/6 to 6/4, and if it deviates from this range, even if the amounts of the other two components are within the predetermined range. Even so, the resulting copolymer cannot exhibit sufficient dispersibility for rosin-based substances.

Although the quaternary copolymer can be prepared by a conventional polymerization method, an emulsion polymerization method is particularly preferred. As an emulsifier for emulsion polymerization, an anionic surfactant and/or a nonionic surfactant with a molecular weight of 100 or less is generally used, but when emulsion polymerizing the four monomer components of the present invention, molecular weight It is optimal to use polyoxyethylene polyoxypropylene with an ff of about 12,000 to 15,000.

During emulsion polymerization, persulfates, hydrogen peroxide, etc. are used as a polymerization initiator in an amount of 1 to 1 to 1% by weight of the monomer mixture as a polymerization initiator.
Use about 5%. In this case, a reducing agent such as a sulfite salt may be used in combination, if necessary, and an oil-soluble peroxide compound or an azo compound may also be used in combination. Furthermore, in order to adjust the molecular weight of the resulting copolymer, chain transfer agents such as mercaptans, thioglycolic acid esters, carbon tetrachloride, and isopropyl alcohol are added.
An appropriate amount can be used depending on the polymerization conditions. The amount of water added at the start of emulsion polymerization is 65-9% of the total reaction mixture.
The desired quaternary copolymer can be obtained by maintaining the amount in the range of 0% by weight, preferably 70 to 75% by weight, and completing the polymerization reaction at a temperature of 50 to 95°C.

By neutralizing this copolymer in a conventional manner, a particularly effective dispersant for the rosin-based substances of the present invention can be obtained. It is preferable to do so. As the neutralizing agent, alkaline compounds such as sodium hydroxide, potassium hydroxide, ammonia, and amines are used alone or in combination.

The alkali neutralized salt of the quaternary copolymer thus prepared is
The rosin-based material of the present invention, that is, the mixture of reinforced rosin and phenolic resin, can be used in a range of 5 to 20% by weight;
The optimum amount used is 10 to 15% by weight.

The alkali neutralized salt of the quaternary copolymer used in the present invention is
It has excellent dispersion ability for rosin-based substances, so
When obtaining an aqueous emulsion from the rosin material by the phase inversion method, it is not necessarily necessary to use a surfactant-based dispersant known in the art. However, the present invention does not exclude the use of these known surfactant-based dispersants.

Therefore, higher alcohol, polyoxyethylene sulfosuccinic acid half ester salt of alkylphenol, alkylarylphenol or polystyrenated phenol, polyoxyethylene sulfate salt of alkylphenol, alkylarylphenol or polystyrenated phenol, alkylbenzene sulfonate, α-olefin sulfone Surfactant-based dispersants such as acid salts can be used in the present invention, but the amount used is within the O range for the rosin-based material.
, L to 1.0% by weight.

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 this melt contains an alkali neutralized salt of the quaternary copolymer described above. First, a homogeneous W10 type emulsion is prepared by thoroughly stirring the aqueous solution while dropping it. Then, warm water was added to this emulsion under vigorous stirring, phase inversion was carried out, and O/
A W-type aqueous emulsion is prepared.

In this case, the total amount of the aqueous solution containing the dispersant is preferably in the range of 30 to 60% by weight of the melt. Furthermore, when dropping the aqueous solution, the temperature of the melt is maintained at a temperature 20°C or more higher than its melting point, and the temperature of the mixture is adjusted to approximately 100°C when the aqueous dispersant solution is dropped. is preferable. After that, 90
The desired aqueous emulsion sizing agent is obtained by dropping hot water at ~95°C under stirring and causing phase inversion.

[Function] The rosin-based emulsion sizing agent obtained by the method of the present invention exhibits low foaming properties and good sizing effects, but this is due to the fact that the reinforced rosin is melted in the coexistence of the phenolic resin. , the compatibility with water is improved compared to when the melt is reinforced rosin alone, and in combination with the strong dispersion ability of the alkali-neutralized salt of the specific quaternary copolymer, a fine and homogeneous emulsion is created. It is presumed that this is because particles can be formed.

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example Preparation of reinforced rosin (A) 100 parts by weight of rosin is melted by heating and the temperature is raised to 190°C. 11 parts by weight of fumaric acid was added to this while stirring, and 200
The reaction was carried out at 0.degree. C., and the reaction was completed when it was confirmed that substantially no unreacted fumaric acid existed. The acid value of the obtained reinforced rosin (A) was 241, and the melting point was (00°C).

Production of quaternary copolymer alkali neutralized salt Add emulsifier (polyoxyethylene polyoxypropylene block polymer, trade name Nijipan U-1) to 290 parts by weight of water.
Dissolve 6 parts by weight of No. 03 (manufactured by Kogyo Seiyaku ■) and add No. 1 to this.
Monomers are added in the mixing ratio shown in the table, and a mixture of 10 parts by weight of isopropyl alcohol and 3 parts by weight of 2-ethylhexyl thioglycolic acid ester is added and stirred. Next, 3 parts by weight of APS and 83 parts by weight of 5B were added, and 75 parts by weight were added.
By reacting at ~80°C for 5 hours to complete polymerization,
A copolymer emulsion with a concentration of 27% was obtained.

After that, 28% aqueous ammonia was added to this emulsion to carry out a neutralization reaction for 1 hour, and then water was added so that the concentration was 25% to form a copolymer with a neutralization degree of 75 mol%. A solution of alkali neutralized salt was obtained.

Table 1 Dispersant A 2 5 0 15 Note) ST: Styrene AA Niacrylic acid MAA: Methacrylic acid 2EHA: 2-Ethylhexyl acrylate A phenolic resin was added to the reinforced rosin (A) produced in the previous preparation row to give 100% Parts by weight were heated to 160°C to melt. Next, a dispersant aqueous solution with a concentration of 20% (component: polyoxyethylene sulfosuccinic acid half ester of nonylphenol Na)
2.5 parts by weight of salt) were added and mixed. The internal temperature was maintained at 98°C by refluxing water. While maintaining this temperature, 50 parts by weight of the dispersant A was added and mixed uniformly. Then, hot water at 90° C. was added and phase inversion was performed to obtain an aqueous emulsion sizing agent with uniform and fine dispersed particles and a concentration of 50%.

Comparative Example 1 Reinforced rosin (A) without using phenolic resin
) An aqueous emulsion sizing agent having a concentration of 50% was obtained by a phase inversion method using 100 parts by weight and a 20% aqueous solution of polyoxyethylene sulfosuccinic acid half ester Na salt of nonylphenol.

Comparative Example 2 (method of JP-A-61-108796) Preparation of Reinforced Rosin (B) Reinforced rosin (B) was prepared in the same manner as the above-mentioned method for preparing reinforced rosin using 100 parts by weight of rosin and 10 parts by weight of fumaric acid.
) was prepared.

Preparation of copolymer dispersant A monomer mixture consisting of 60 parts by weight of styrene, 25 parts by weight of acrylic acid, and 15 parts by weight of 2-ethylhexyl acrylate, 5 parts by weight of dodecyl mercaptan, and polyoxyethylene (n=lO) nonylphenyl ether. Add 5 parts by weight of sulfuric acid ester and 3 parts by weight of ammonium persulfate to 3 parts by weight of water.
00 parts by weight and mixed, and emulsion polymerization was carried out at 80° C. for 4 hours. Next, the temperature was cooled to 60°C, and 30.4 parts by weight of a retested potash aqueous solution with a concentration of 48.5% and 30 parts by weight of water were gradually added dropwise, stirred for 30 minutes, and then cooled to obtain a neutralized product with a degree of saponification of 75%. I got it. Water was added to this to obtain a dispersant X having a concentration of 25%.

Further, a dispersant Y having a concentration of 25% was obtained using the same recipe as above except that 25 parts by weight of methacrylic acid was used in place of 25 parts by weight of acrylic acid.

Using the thus obtained reinforced rosin (B) and dispersants X and Y, an aqueous emulsion sizing agent having a concentration of 50% was obtained in the same manner as in the example.

The appearance, light transmittance, foamability, and size effect of each emulsion sizing agent obtained in the above Examples and Comparative Examples were evaluated by the following methods. The results regarding appearance and light transmittance are shown in Table 2, and the results regarding foamability and size effect are shown in Table 3.

Appearance 50cc of sizing agent in a 200cc transparent glass bottle
Collect the bottle, leave it standing with the cap turned upside down, and observe with the naked eye the state in which the sizing agent flows down the bottle wall in a thin layer.

◎: No coarse particles present, within io seconds A sense of transparency appears.

○: No coarse particles exist, after 20 seconds A sense of transparency appears.

△: Coarse particles are present, after 20 seconds or more A sense of transparency appears over time.

Light transmittance The sizing agent was diluted to a solids concentration of 0.05% by weight using deionized water and measured using a diffraction grating photoelectric colorimeter (Sp
The light transmittance at a wavelength of 560no+ was measured using ectronlc 20 (manufactured by Shimadzu Corporation). The light transmittance of each sizing agent is expressed as a relative value when the light transmittance of pure deionized water is taken as 100%, and the higher the value, the finer the dispersed particle diameter of the sizing agent sample.

(Left below) Foaming test Pulp slurry with a concentration of 0.75% = (Pulp L-BKP C8F16Oml) 80ml, Loo
Collect the sample in a graduated cylinder with a stopper and add 1%
Add 1 ml of band solution and shake 20 times. Next, 1 ml of a diluted sizing agent solution with a solid content concentration of 1% is added, and the mixture is further shaken up and down 20 times. After that, it is left to stand for 5 minutes, and the amount of Western species generated is determined by MIJ. The larger the value, the greater the foaming property.

Size effect test L-BKP (C3F400ml
) to pulp slurry with a concentration of 2.4%, add 20% talc and 0.2% emulsion sizing agent to the bone-dry pulp weight, mix thoroughly, and then add a predetermined amount of sulfuric acid band. (See Table 2) and prepared pulp slurry.

The paper was then hand-sheeted using a TAPPI standard sheet machine in accordance with a conventional method, water squeezed at a press pressure of 8.5 kg/c♂, and then dried for 1 minute using a drum dryer (surface temperature: 70°C) to prepare hand-sheeted paper.

The obtained handmade paper had a paper weight of 160 g/rrr, and after conditioning the humidity, the Steckigt sizing degree was measured according to JIS P-8122.

Sizing agent foaming Symbol: floating species amount size effect Addition amount 0.5% Addition amount 2% 7 12 8 15 7 12 8 15 7 12 8 6 4 4 However, the amount added indicates the amount of band added.

[Effects] As is clear from the above explanation, the rosin-based emulsion sizing agent obtained by the method of the present invention has very fine size particles and is stably dispersed, and the content of the dispersant is small, so it is difficult to pulp. It is characterized by extremely little foaming when added to the slurry and also has a good size effect. Therefore, the present invention has high industrial value as a method for producing a sizing agent that can solve problems caused by the sizing agent due to deterioration of water usage in the papermaking process.

Claims (1)

[Claims] 1. A molten rosin-based material 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, and then the dispersion is 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 water to the liquid and inverting the phase, as the rosin-based substance, A mixture of phenolic resin and reinforced rosin is used, and an alkali neutralized salt of a quaternary copolymer consisting of styrene monomer, acrylic acid ester, acrylic acid, and methacrylic acid is used as the dispersant. A method for producing a rosin-based emulsion sizing agent. 2. The method according to claim 1, wherein the amount of the alkali neutralized salt of the quaternary copolymer used is in the range of 5 to 20% by weight of the rosin-based material. 3. The quaternary copolymer described above has a molecular weight of 2000 to 1500
3. The method according to claim 2, which is prepared by an emulsion polymerization method using 0 polyoxyethylene polyoxypropylene as an emulsifier.