JP2002201434A - Production method for colorless polymerized rosin ester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new production method whereby a colorless polymerized rosin ester highly improved in its color tone is obtained without detriment to the characteristics inherent in a conventional polymerized rosin ester. SOLUTION: This method is characterized in that purified polymerized rosin (1) obtained by polymerizing purified rosin is esterified with an alcohol and the resultant ester (2) is hydrogenated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a colorless polymerized rosin ester.

[0002]

2. Description of the Related Art Esterified polymerized rosin obtained from gum rosin, wood rosin or tall oil rosin has excellent properties such as pigment dispersibility, compatibility, tackiness and adhesive strength. It has been awarded as a binder and additive in a wide range of fields such as agents. However, their appearance is generally yellow to brown, and is about 7 to 11 in Gardner color number. When such a polymerized rosin ester having inferior color is used for the above purpose, the hue of the printing ink or paint is changed, and a yellowish color is obtained as a tacky / adhesive agent. is there.

[0003] Therefore, there is a demand for the development of colorless polymerized rosin esters in these applications. However, to the present applicant's knowledge, the fact is that a colorless polymerized rosin ester that can solve such problems has not yet been developed and put on the market.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a novel process for producing a colorless polymerized rosin ester which retains the properties of the conventional polymerized rosin ester and which has a markedly improved color tone. The purpose is to provide.

[0005]

Means for Solving the Problems In view of the above-mentioned problems found in conventional polymerized rosin esters, the present inventors have conducted intensive studies, and as a result, have used a specific rosin as a raw material rosin, polymerized the rosin, and then obtained an ester. The present inventors have found that a colorless polymerized rosin ester capable of solving the above-mentioned problems can be obtained by converting and further hydrogenating, and the present invention has been completed.

That is, the present invention provides a process for producing a colorless polymerized rosin ester, which comprises esterifying a purified polymerized rosin (1) obtained by polymerizing a purified rosin with an alcohol, and then hydrogenating the ester (2). About.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, first, it is essential to use a purified rosin (purified gum rosin, purified wood rosin, and purified tall oil rosin) as a rosin as a starting material. Here, purification means removing high-molecular-weight substances that are considered to have arisen from peroxide contained in the unpurified rosin as a starting material, and unsaponifiable substances originally contained in the rosin. . Specifically, distillation,
Operations such as recrystallization and extraction may be performed, and purification by distillation is industrially preferable. In the case of distillation, the temperature is appropriately selected usually in the range of 200 to 300 ° C. and pressure of 130 to 1300 Pa in consideration of the distillation time. In the case of recrystallization, for example, unpurified rosin is dissolved in a good solvent, then the solvent is distilled off to form a concentrated solution, and a poor solvent is added to this solution. Good solvents include benzene, toluene, xylene, chloroform, lower alcohols, ketones such as acetone, acetates such as ethyl acetate, and the like.
Examples include n-heptane, cyclohexane, isooctane and the like. Further, in the above-mentioned purification, purified rosin can be obtained by converting unpurified rosin into an aqueous alkali solution using alkaline water, extracting the resulting insoluble unsaponifiable substance with an organic solvent, and then neutralizing the aqueous layer.

In the present invention, a step of polymerizing the purified rosin to obtain a purified polymerized rosin (1) is essential.
The conditions for such a polymerization reaction are not particularly limited, and are appropriately selected and determined from conventionally known conditions. For example, purified rosin is sulfuric acid, hydrogen fluoride, zinc chloride, aluminum chloride, titanium tetrachloride, toluene containing a catalyst such as styrene-divinylbenzene copolymer sulfonate,
In a solvent such as xylene or halogenated hydrocarbon, the temperature is 40 to
For example, a method of reacting at about 160 ° C. for about 1 to 10 hours may be used. After the completion of the polymerization reaction, the solvent, the catalyst, the unreacted purified rosin, and the decomposed product are removed from the polymerization reaction product, if necessary, to obtain a purified polymerization rosin (1). As a method for removing the catalyst, for example, washing with water, filtration and the like can be adopted, and as a method for removing the unreacted purified rosin and the decomposition product, vacuum distillation can be adopted. The color tone (Gardner color number) of the purified polymerized rosin (1) obtained as described above is about 4 to 7, and at this level it is hard to say that it is colorless or pale.

The purified polymerized rosin (1) thus obtained
Is a mixture composed of purified rosin (monomer) as an unreacted substance, a dimer component obtained by dimerization of the rosin, and a component having a molecular weight larger than that of the dimer component. The content of the polymer in the purified polymerized rosin (1) varies depending on the reaction temperature, the reaction time, the type of catalyst, the conditions for removing unreacted purified rosin from the polymerized product, and the like during the polymerization reaction. Reaction conditions and the like can be appropriately selected so as to obtain the content. The content of the polymer in the purified polymerized rosin (1) used in the present invention is not particularly limited,
It may be determined according to the use of the finally obtained colorless polymerized rosin ester. Usually, it is about 10 to 85% by weight, preferably 20 to 80% by weight.

In the production method of the present invention, a step of esterifying the purified polymerized rosin (1) with an alcohol is essential. In the esterification reaction, ordinary conditions can be employed as they are. For example, purified polymerized rosin (1) and the following alcohols are usually mixed in an inert gas stream for 150 minutes.
It may be carried out by heating to ~ 300 ° C and removing generated water out of the system. Examples of the alcohol include, but are not particularly limited to, monohydric alcohols such as n-octyl alcohol, 2-ethylhexyl alcohol, decyl alcohol, and lauryl alcohol; ethylene glycol, diethylene glycol, propylene glycol, neopentyl glycol, cyclohexane dimethanol, and the like. Dihydric alcohols; trihydric alcohols such as glycerin, trimethylolethane, and trimethylolpropane; and tetrahydric alcohols such as pentaerythritol and diglycerin. Note that, in the reaction, an esterification catalyst is not necessarily required, but acetic acid, an acid catalyst such as paratoluenesulfonic acid, an alkali metal hydroxide such as calcium hydroxide, calcium oxide, Metal oxides such as magnesium oxide can also be used. In this step, an antioxidant can be used as necessary.

The purified polymerized rosin ester (2) thus obtained usually has a color tone (Gardner color number) of about 5 to 8.

In the production method of the present invention, a step of hydrogenating the purified polymerized rosin ester (2) is essential as a final step. In the hydrogenation reaction, known hydrogenation reaction conditions can be appropriately selected. That is, the purification is carried out by heating the purified polymerized rosin ester (2) under a hydrogen pressure of usually 1 to 25 MPa, preferably 5 to 20 MPa in the presence of a hydrogenation catalyst. Examples of the hydrogenation catalyst include various known catalysts such as supported catalysts such as palladium carbon, rhodium carbon, ruthenium carbon, and platinum carbon; metal powders such as nickel and platinum; and iodides such as iodine and iron iodide. Particularly preferred are palladium, rhodium, ruthenium or platinum based catalysts. The amount of the catalyst to be used is generally 0.1 to the purified polymerized rosin ester (2).
0.01 to 5% by weight, preferably 0.01 to 2.0% by weight, and the reaction temperature is 100 to 300 ° C, preferably 150 to
２290 ° C.

The colorless polymerized rosin ester obtained by this production method has a color tone (Gardner color number) of 1 or less and a Hazen color number of about 300 to 30, preferably 200 to 30. Since the softening point, molecular weight and acid value of the colorless polymerized rosin ester mainly depend on the alcohol species that are the constituents thereof, these ranges cannot be particularly limited, but may be appropriately adjusted according to the use. You only have to decide. The softening point of the colorless polymerized rosin ester is usually about 100 to 175 ° C, preferably 130 to 170 ° C.
° C, and the weight average molecular weight (polystyrene conversion) is 10
The acid value is about 100 to 3000, preferably about 1500 to 2500, and the acid value is about 10 to 30 mgKOH / g, preferably 10 to 20 mgKOH / g.

The colorless polymerized rosin ester obtained by the production method of the present invention may contain a phenolic antioxidant,
Various additives such as a phosphorus-based antioxidant and an ultraviolet absorber can be added. The colorless polymerized rosin ester can be suitably used for various applications as described above, as it is, or in the form of a dispersion or an emulsion appropriately dispersed in a solvent.

[0015]

According to the present invention, the characteristics (pigment dispersibility, compatibility, viscosity / adhesion, etc.) of the conventional polymerized rosin ester are maintained, and the color tone and the color tone stability upon heating are remarkably improved. Thus, a colorless polymerized rosin ester can be provided.

[0016]

EXAMPLES The present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. In each case,% is based on weight.

Example 1 (1) Purification Unpurified rosin (gum rosin produced in China) of 170.0 mgKOH / g, softening point of 78 ° C. and color tone Gardner 6 was distilled under a reduced pressure of 400 Pa under a nitrogen seal. The main fraction shown in (1) was used as purified rosin. The purified rosin has an acid value of 17
It has a general constant of 8.4 mgKOH / g, a softening point of 88 ° C., and a color tone (Gardner color number) of 3.

[0018]

[Table 1]

(2) Polymerization reaction 700 g of the purified rosin obtained in (1), 700 g of xylene, and 17.5 zinc chloride as a polymerization catalyst were placed in a reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube and a decompression device.
g was charged and a polymerization reaction was carried out at 140 ° C. for 7 hours.
After washing 1417 g of a xylene solution of the reaction product with 500 g of warm water, 7 g of concentrated hydrochloric acid and 500 g of warm water were added to wash. After washing twice with 500 g of warm water each time, xylene was distilled off under the conditions of a liquid temperature of less than 200 ° C. and a degree of vacuum of 1300 Pa. Further, the liquid temperature is 200 to 275 ° C and the degree of decompression is 40.
The decomposition product of purified rosin and unreacted purified rosin (200 g in total) were distilled off under the condition of 0 Pa, and the acid value was 135.3 mgK.
OH / g, softening point 146 ° C, color tone (Gardner color number) 6
471 g of a purified polymerized rosin was obtained. By GPC measurement,
It was found that the polymer content in the purified polymerized rosin was 71.3%, the monomer (a hydride of purified rosin) was 27.1%, and the decomposition product was 1.6%.

(3) Esterification reaction 230 g of the purified polymerized rosin obtained in (2) was placed in a reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube and a pressure reducing device.
Glycerin (21.2 g) was charged under a stream of nitrogen.
C. for 2 hours and 270.degree. C. for 10 hours, acid value 10.2 mg KOH / g, softening point 168
A purified polymerized rosin ester having a color tone (Gardner color number) of 6 ° C. was obtained.

(4) Hydrogenation reaction Next, 150 g of the purified polymerized rosin ester obtained in (3), 1.5 g of 5% palladium carbon (water content 50%) as a hydrogenation catalyst, and 150 g of cyclohexane were charged into an autoclave reactor. After removing oxygen in the system, pressurize the system with hydrogen to 10 MPa, and
The temperature was raised to 0 ° C, and a hydrogenation reaction was carried out at the same temperature for 3 hours to obtain a colorless polymerized rosin ester having an acid value of 17.4 mgKOH / g, a softening point of 148 ° C, and a color tone (Hazen color number) of 50.

Example 2 An esterification reaction was carried out in the same manner as in Example 1 (3) except that 25.3 g of pentaerythritol and 1.2 g of glycerin were used instead of 21.2 g of glycerin, and an acid value of 17.3 mg KOH was used. / G, a softening point of 171 ° C. and a color tone (Gardner color number) of 7 were obtained. Then, a hydrogenation reaction was carried out in the same manner as in Example 1 (4), and the acid value was 18.1 mgKOH / g and the softening point was 161.
A colorless polymerized rosin ester having a color tone (Hazen color number) of 80 ° C. was obtained.

Comparative Example 1 (Hydride of unpurified polymerized rosin ester) Using unpurified rosin (gum rosin produced in China) having an acid value of 170.0 mgKOH / g, a softening point of 78 ° C. and a color tone of Gardner 6, was prepared in the same manner as in Example 1 (2). ) To under the same conditions as in Example 1 (4),
A polymerization reaction, an esterification reaction and a hydrogenation reaction were performed to obtain a hydride of a crude polymerized rosin ester. The hydride has an acid value of 17.5 mg KOH / g, a softening point of 147 ° C,
The color tone (Gardner color number) was 5.

Comparative Example 2 (Hydride of Unpurified Polymerized Rosin Ester) Using the same unpurified rosin as in Comparative Example 1, a polymerization reaction, an esterification reaction and a hydrogenation reaction were carried out under the same conditions as in Example 2. Thus, a hydride of a crude polymerized rosin ester was obtained. The hydride has an acid value of 18.8 mgKOH / g,
The softening point was 160 ° C. and the color tone (Gardner color number) was 6.

(Evaluation of Performance) The performance of each polymerized rosin ester obtained in each of the examples and comparative examples was evaluated under the following conditions. The results are shown in Table 2. (Heating stability) 10 g of a sample was placed in a test tube having an inner diameter of 1.5 cm and a height of 15 cm, and was allowed to stand in a circulating drier at 200 ° C. without covering, and the color tone over time (Gardner color number)
Was observed.

[0026]

[Table 2]

Claims (7)

[Claims] 1. A process for producing a colorless polymerized rosin ester, comprising the step of esterifying a purified polymerized rosin (1) obtained by polymerizing a purified rosin with an alcohol and then hydrogenating the ester (2). 2. The process according to claim 1, wherein the color tone (Gardner color number) of the purified polymerized rosin (1) is 4 to 7. 3. The process according to claim 1, wherein the content of the polymer in the purified polymerized rosin (1) is 10 to 85% by weight. 4. The method according to claim 1, wherein the purified polymerized rosin ester (2) has a color tone (Gardner color number) of 5 to 8. 5. The production method according to claim 1, wherein the hydrogenation conditions are a hydrogen pressure of 1 to 25 MPa and a temperature of 100 to 300 ° C. 6. The process according to claim 1, wherein the hydrogenation catalyst is at least one selected from the group consisting of palladium, rhodium, ruthenium and platinum-based catalysts. 7. The production method according to claim 1, wherein the colorless polymerized rosin ester has a color tone (Gardner color number) of 1 or less.