JPH052686B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention involves modifying high molecular weight crystalline 1,2-polybutadiene or high molecular weight 1,4-polybutadiene by a polymer reaction on its unsaturated double bonds to obtain a substantial gel content. The present invention relates to a method for producing a novel hydrophilic polymer having an unsaturated double bond in its polymer structure, or an aqueous solution thereof, which does not have an unsaturated double bond. It is used in various other fields including. [Prior art and problems to be solved by the invention] Various water-soluble polymers have been known. For example, natural polymers include alginic acid (sodium alginate), carboxymethyl cellulose (CMC), and methylcellulose [MC:
Methyl etherified cellulose (25-32%)]
Examples include saccharides, polysaccharides, and chemically modified products thereof, and further examples of water-soluble polysaccharides produced by microorganisms include pullulan, dextran, and xanthan gum. Examples of synthetic polymers include polyvinyl alcohol (poval), polyethylene oxide, sodium polyacrylate, and polyacrylamide. These water-soluble polymers have no unsaturated bonds in their polymer structure. The above-mentioned water-soluble polymers are used in various ways in the field of water-soluble polymer materials, taking advantage of their respective property characteristics. For example, adhesives, paints, fiber processing agents, sizing materials, sticky agents for Japanese paper, paperboard, papermaking, emulsifiers, flocculants, liquid friction resistance reducers, thickeners, asphalt emulsifiers, spreading agents for agricultural chemicals, pigment dispersants. In addition to industrial fields such as latex thickeners, soil conditioners, and printing pastes, we also produce ice cream additives, food processing, pharmaceuticals and cosmetics, beer foam stabilizing agents, dietary foods, pharmaceutical tablets, plasma expanders, etc. It is also used in large quantities in bio-related fields. The amount of water-soluble polymers used in the field of water-soluble polymer materials has reached a total of several hundred thousand tons/year (in Japan), and water-soluble polymers with special characteristics are increasingly being sought after. On the other hand, attempts have also been made to make diene polymers having unsaturated double bonds hydrophilic for use in electrodeposition coatings and the like. Originally, diene polymers such as polybutadiene are insoluble in highly polar solvents such as water and alcohols, but if these polymers can be dissolved in water and alcohols, they can be used in many fields of application. can do. Therefore, a large number of various methods have been reported for making diene polymers water-soluble, and they can be broadly classified as follows. (1) Maleation of polybutadiene or further reaction of the maleated product to increase hydrophilicity. (2) Copolymerization of butadiene with other vinyl monomers, or synthesis of butadiene derivatives by reaction of butadiene monomers and their special properties. A method of imparting hydrophilicity by polymerizing a monomer (3) A method of making the polymer hydrophilic by epoxidizing polybutadiene and then opening the oxirane ring with a carboxylic acid, secondary amine or diamine (4) A method of imparting hydrophilicity to the polymer by polymerizing the above ( Methods of making polymers hydrophilic by chemical modification (addition of sulfonic acid groups, etc.) other than methods 1) to (3) However, in the literature, polymers obtained by the above-mentioned known methods are Even if it is described as water-soluble or water-dilutable, it is actually a latex-like substance that is different in concept from water-soluble, and can be diluted with water in the coexistence of a large amount of water-compatible organic solvents such as cellosulbu. Most of them are water-soluble, and very few are truly water-soluble. In addition, in the above-mentioned known method, the base polybutadiene to be chemically modified has a molecular weight of
Low molecular weight (liquid) polybutadiene with a molecular weight of less than 10,000 is used in most cases, high molecular weight polymer with a molecular weight of 10,000 or more is hardly used, and high molecular weight crystalline 1,2-polybutadiene is not used at all. High-molecular-weight polybutadiene is produced in much larger quantities than low-molecular-weight polybutadiene, is used in many fields, and has many characteristics in terms of use. However, high molecular weight polybutadiene is insoluble in water and lower alcohols such as methyl alcohol and ethyl alcohol, and is usually insoluble in aromatic hydrocarbon solvents such as benzene, toluene, xylene, or halogen solvents such as chloroform, carbon tetrachloride, and chlorobenzene. Although it dissolves relatively well in these solvents, all of these solvents are highly toxic. Therefore, the use of high molecular weight polybutadiene is largely limited in applications such as coating, coating, and painting as a polymer solution. It is therefore an object of the present invention to provide novel modified polymers having the hydrophilic properties of high molecular weight polybutadiene. [Means for solving the problem] As a result of intensive research, the present inventors have determined that the unsaturated double bonds of high molecular weight crystalline 1,2-polybutadiene or high molecular weight 1,4-polybutadiene are reduced in a specific proportion. and then heating in the presence of a secondary amine to open the epoxy ring at a specific rate to form a tertiary amine structure, which is then reacted with an acid to form a tertiary amine salt. In particular, a hydrophilic diene-based modified polymer that achieves the above objective can be obtained, and the reaction proceeds smoothly without gelation of the polymer during the reaction, so that the obtained modified polymer is substantially The present invention was achieved based on the finding that it does not have a gel content. The present invention was made based on the above findings, and
At least 75% of the unsaturated double bonds are 1,2-bonds, the melting point is 60 to 170℃, and the reduction year (ηsp/c) (200
mg/100ml of tetralin solution, 100℃) is 0.2
The above crystalline 1,2-polybutadiene or the 1,4-polybutadiene in which 85% or more of the unsaturated double bonds are 1,4-bonds and the average molecular weight is 50,000 or more is epoxidized. For polybutadiene, the epoxidation rate is 5 to 45% of its unsaturated double bonds, and for the above 1,4-polybutadiene, the epoxidation rate is 5 to 60% of its unsaturated double bonds, and then these epoxidized Polybutadiene is heated in the presence of a secondary amine to open 5% or more of the unsaturated double bonds in the polybutadiene before epoxidizing the epoxy ring, and an amine is introduced. The present invention provides a method for producing a hydrophilic polymer or an aqueous solution thereof, characterized in that 5% or more of the amine structure is neutralized with an acid. The novel modified polymer obtained by the production method of the present invention is obtained as an aqueous polymer solution or a polymer dispersion using water as the main solvent, and is a hydrophilic polymer having a high molecular weight and having an unsaturated double bond in its polymer structure. It is a polymer and can be used not only in the conventionally known application fields of water-soluble polymers, but also by taking advantage of its characteristics of having unsaturated double bonds (photosensitivity, imparting rubbery properties, curing by thermal crosslinking, etc.) . The method for producing the hydrophilic polymer or its aqueous solution of the present invention will be described below in detail based on its embodiments. The crystalline 1,2-polybutadiene used to make it hydrophilic in the present invention has a 1,2-bond content of 75% or more, a melting point of 60 to 170°C, and a reduction year (ηsp/c) (200 mg/100 ml). Syndiotactic-1,2 with a concentration of tetralin solution (100℃) of 0.2 or more, preferably with a reduced viscosity of 0.5 to 3.0.
- Polybutadiene, more preferably one having an average molecular weight of 50,000 or more. Crystalline 1,2-polybutadiene having a melting point higher than the above range is practically unusable because it is difficult to dissolve in the reaction solvent under the epoxidation reaction conditions during epoxidation. The above-mentioned crystalline 1,2-polybutadiene can be used, for example, in Japanese Patent Publications No. 47-19893, Japanese Patent Publications No. 18005-1980, Japanese Patent Publications No. 5436-1987, Japanese Patent Publications No. 18128-1980, Japanese Patent Publications No. 56-18128,
No. 18129, Special Publication No. 18130, Special Publication No. 53-39917
It can be manufactured by the method described in each bulletin of the issue. In addition, the 1,4-polybutadiene used for hydrophilization in the present invention has a 1,4-bond content (cis-1,4-bond and trans-1,4-bond).
- 1,4-polybutadiene with a high molecular weight of 85% or more and an average molecular weight of 50,000 or more. In addition, hereinafter, when simply referred to as polybutadiene, the above-mentioned crystalline 1,2-polybutadiene and the above-mentioned 1,4-
Refers to both polybutadiene. Therefore, the present invention provides these polybutadienes by partial epoxidation of polybutadiene (first stage reaction), ring opening of the epoxy ring of epoxidized polybutadiene (second stage reaction), and bonded tertiary amine in the ring-opened polymer. It is modified to make it hydrophilic by performing a three-step reaction of neutralizing the structure (third-stage reaction). First, the partial epoxidation of polybutadiene in the first stage reaction will be explained. What is important in this first stage reaction is to control the proportion of unsaturated double bonds (epoxidation rate) in the polybutadiene to be epoxidized. 5-45%, preferably 10-40% for bonding
%, and when 1,4-polybutadiene is used as the polybutadiene, it is preferably 15 to 45% based on all unsaturated double bonds. Polybutadiene that has been epoxidized above the upper limit of the epoxidation rate (45% for crystalline 1,2-polybutadiene, 60% for 1,4-polybutadiene) may gel or undergo the second stage reaction. It becomes insoluble in solvents during the ring-opening reaction step of the epoxy ring. In addition, polybutadiene epoxidized to a lower limit than the lower limit of the epoxidation rate (5% in either case) may not become hydrophilic even after the following second and third stage reactions, or may not become hydrophilic. becomes inadequate. In the present invention, the method of epoxidizing polybutadiene is not particularly limited, and methods such as chlorohydrin method, direct oxidation method, hydrogen peroxide method, alkyl hydroperoxide method, peracid method, etc. Any conventionally known method can be used to epoxidize a compound having . To further explain the epoxidation of polybutadiene by the above peracid method (in situ-peracid method), this epoxidation involves adding an organic acid and hydrogen peroxide to a solution of polybutadiene in an inert organic solvent. The reaction formula is as follows. RCO ₂ H＋H ₂ O ₂ RCO ₃ H＋H ₂ O (1) That is, an organic acid reacts with hydrogen peroxide to form a peracid, which acts on the unsaturated double bonds of polybutadiene to epoxidize the polybutadiene. It is thought that the organic acid produced in the above reaction formula (2) repeats the same reactions as in the above reaction formulas (1) and (2). Formic acid, benzoic acid, acetic acid, etc. can be used as the organic acid, and it is particularly preferable to use formic acid because of its fast epoxidation reaction rate. The inert organic solvent may be one that dissolves polybutadiene, is sparingly soluble in water, and is inert to hydrogen peroxide (or peracid), such as
Hydrocarbons such as benzene, toluene, xylene, cyclohexane; chloroform, carbon tetrachloride,
Halogenated hydrocarbons such as chlorobenzene can be used alone or in combination of two or more. Alternatively, a solution of polybutadiene in an inert organic solvent can be prepared by adding polybutadiene to an inert organic solvent.
Usually 0 to 80℃, preferably 20 to 60℃ for 1 minute to 1
A method of dissolving the polybutadiene in an inert organic solvent by stirring and mixing for a period of time, or a method of adding a polymerization terminator such as water or hydrochloric acid to the polybutadiene polymerization solution to stop the polymerization, and then deashing it by washing with water or the like. can get. The reaction conditions for epoxidation, such as the concentration of polybutadiene in the inert organic solvent solution of polybutadiene, the amount of organic acid and hydrogen peroxide added to it, and the method of their addition, depend on the type of organic acid used and the target. For example, in the case of a peracid method using formic acid as the organic acid, the following reaction conditions are usually employed, although the reaction conditions are not limited as they vary depending on the epoxidation rate and the like. When crystalline 1,2-polybutadiene is used as the polybutadiene, the crystalline 1,2-polybutadiene solution in an inert organic solvent is
The concentration of polybutadiene is approximately 1-30%, and the amount of formic acid added is per 100g of crystalline 1,2-polybutadiene.
The amount of hydrogen peroxide added is preferably 0.1 to 2 mol, and the amount of hydrogen peroxide added is preferably 0.2 to 4 mol per 100 g of crystalline 1,2-polybutadiene. Also, as polybutadiene, 1,4
- When polybutadiene is used, the concentration of 1,4-polybutadiene in the inert organic solvent solution is about 1 to 30% by weight, and the amount of formic acid added is 0.01 per 100 g of 1,4-polybutadiene.
-2 mol, and the amount of hydrogen peroxide added is preferably 0.1 to 4 mol per 100 g of 1,4-polybutadiene. The amounts of formic acid and hydrogen peroxide added can be changed depending on the target epoxidation rate. Further, hydrogen peroxide is preferably added to a solution of polybutadiene in an inert organic solvent as a 20 to 60% by weight hydrogen peroxide solution. There is no particular restriction on the method of adding formic acid and hydrogen peroxide to a solution of polybutadiene in an inert organic solvent, but the method of adding formic acid to a solution of polybutadiene in an inert organic solvent, mixing, and adding the solution to the resulting solution is not particularly limited. 0
A preferred method is to gradually add a hydrogen peroxide solution having a concentration within the above range while maintaining the temperature at ~80°C. After adding formic acid and hydrogen peroxide in the above specified amounts to the above inert organic solvent solution of polybutadiene, this mixture is heated to 0 to 80°C, preferably 20 to 60°C.
℃, preferably stirring and mixing for 10 minutes to 10 hours,
Epoxidize polybutadiene. When the reaction temperature of epoxidation is lower than the above lower limit,
Polybutadiene is difficult to epoxidize, and if it is higher than the above upper limit, hydrogen peroxide and peracid are likely to decompose, which is dangerous. In addition, a small amount of a stabilizer such as 2,6-di- Tertiary-butyl-P
-Cresol (BHT) etc. can be added, and the addition of such stabilizers is a preferred method. Next, the ring-opening reaction of the epoxy ring of the epoxidized polybutadiene, which is the second stage reaction, will be explained. In the ring-opening reaction of the epoxy ring in the second stage reaction, polybutadiene (epoxidized polybutadiene) whose unsaturated double bonds have been epoxidized at the predetermined ratio in the first stage reaction is reacted in the presence of a secondary amine. The polymer is heated and reacted to open the epoxy ring and introduce an amine, giving the polymer a tertiary amine structure. In the second stage reaction, after the first stage reaction is completed, epoxidized polybutadiene is separated from the reaction product liquid and dissolved in a secondary amine or a reaction solvent containing a secondary amine, or epoxidized polybutadiene is separated from the reaction product liquid. This can be carried out by directly adding the secondary amine to the reaction product liquid following the first stage reaction without separating the polybutadiene. The separation of epoxidized polybutadiene from the reaction product liquid of the first stage reaction can be carried out using a conventionally known separation method. The inert organic solvent in the reaction product solution can be separated by precipitating and separating the rubber-like epoxidized polybutadiene by adding it to a sparingly soluble organic solvent, or by washing the reaction product solution with water and then steam distilling it. This can be carried out by a method in which low-boiling substances such as formic acid (organic acid) are evaporated and epoxidized polybutadiene is precipitated and separated. Note that the second stage reaction is performed at a relatively high temperature (40 to 40℃) as described below.
(180℃), and if a large amount of hydrogen peroxide or formic acid remains, the polymer may gel during the reaction. It is preferable to wash the reaction product liquid with water at a relatively low temperature to remove most of the hydrogen peroxide and formic acid. The secondary amine used in the second stage reaction preferably has 10 or less carbon atoms. Examples of such secondary amines having 10 or less carbon atoms include dimethylamine,
diethylamine, di-n-propylamine, di-
Aliphatic secondary amines such as n-butylamine and di-n-pentylamine; cycloaliphatic secondary amines such as morpholine, 2,6-dimethylmorpholine, piperidine, 1-methylpiperazine, and pyrrolidine;
In addition to mixed secondary amines such as N-methylaniline and N-ethylaniline, N-methylbenzylamine, N-methylcyclohexylamine, and diallylamine can be mentioned. Among the above-mentioned secondary amines, those having low steric hindrance in reaction with the epoxy ring, such as linear aliphatic secondary amines and dry aliphatic secondary amines, are preferred. When these secondary amines are used, the polymer is less likely to gel during the reaction or post-treatment. In addition, linear aliphatic secondary amines and dry aliphatic secondary amines are particularly preferred because they react quickly with epoxy rings and produce polymers with better hydrophilicity. The preferred amount of the secondary amine used is 200 g to 10 kg per 100 g of epoxidized polybutadiene. The reaction solvent that can be used in the second stage reaction is a solvent that dissolves both the epoxidized polybutadiene and the polymer produced well, and that does not react with either of them or with the secondary amine. Examples include dimethylform. Amide, dimethylacetamide, hexamethylphosphoramide, dimethylsulfoxide, N-methylpyrrolidone, tetrahydrofuran, dioxane, and the like. Further, the second stage reaction can also be carried out without using the above-mentioned reaction solvent, with the above-mentioned secondary amine also serving as the reaction solvent, which is often preferable because the process is simpler. Water can also be used as a co-solvent. The concentration of epoxidized polybutadiene in the reaction solvent solution of epoxidized polybutadiene is 1 to 50% by weight.
It is preferable that In addition, in the second stage reaction, phenols, acids, water, etc. are used as a reaction catalyst to increase the reaction rate.
Additives such as alcohols (hereinafter referred to as catalysts)
It is particularly preferable to use Examples of the above phenols include phenol,
Examples of the acids include p-toluenesulfonic acid, salicylic acid, formic acid, benzoic acid, lactic acid, oxalic acid, acetic acid, n-butyric acid, etc., and examples of the alcohols include methyl alcohol, ethyl alcohol, etc. Examples include alcohol, propyl alcohol, butyl alcohol, and cyclohexyl alcohol. The preferred amount of these catalysts added is 0.05 to 5 mol per 100 g of epoxidized polybutadiene. Among these catalysts, substances that easily donate protons have a remarkable effect of accelerating the reaction. Furthermore, the effect of adding phenol is also excellent. The ability of these catalysts is thought to be proportional to the strength of the vinegar, and the reaction acceleration effect is thought to be proportional to the amount of catalyst added. The reaction conditions for the second stage reaction are usually a reaction temperature of 40°C.
-180°C, reaction time 1-30 hours. Use of the above catalyst allows the reaction temperature to be lowered, and as a result, high-temperature gelation of high molecular weight polybutadiene can be prevented. Further, the addition of this catalyst is also important in obtaining a modified polymer with better hydrophilicity. There is a concern that the above-mentioned catalyst itself electrophilically opens the epoxide of the epoxidized polybutadiene, but in an amine-rich reaction system, the electrophilic ring-opening caused by the catalyst can be substantially ignored. It is not necessary to react (ring open) all the epoxy rings of the epoxidized polybutadiene in the second stage reaction, and in the case of crystalline 1,2-polybutadiene, the crystalline 1,2-
5 based on the unsaturated double bond of polybutadiene
It is sufficient to open the ring by ~45%, preferably 10-40%,
In the case of 1,4-polybutadiene, it is 5 to 60%, preferably 15% based on the unsaturated double bonds of 1,4-polybutadiene before epoxidizing the epoxy ring.
It is sufficient to open the ring by ~45%. That is, for example, if only 5% is epoxidized, all of the ring must be opened, but if 45% (60% in the case of 1,4-polybutadiene) is epoxidized, all of the ring must be opened. The ring may be opened, or the ring may be opened by 5% based on the unsaturated double bonds of the polybutadiene before epoxidation. The amount of epoxy rings remaining in the produced polymer after the completion of the second stage reaction can be roughly estimated by ¹ H-NMR. That is, the produced polymer was dissolved in heavy chloroform (CDCI ₃ ), heavy water (D ₂ O) or heavy methanol (CD ₃ OD) and ¹ H
- Measure NMR to determine the epoxymethine protons and epoxymethylene protons before and after the second stage reaction.

[Formula] or

〔Effect of the invention〕

According to the method for producing a hydrophilic polymer or an aqueous solution thereof of the present invention, a novel modified polymer having hydrophilic properties of high molecular weight polybutadiene or an aqueous solution thereof can be obtained, and at the same time, the polymer gels during the reaction. Since the reaction proceeds smoothly without any gelation, the resulting modified polymer has no substantial gel content. In addition, the modified polymer obtained by the production method of the present invention is obtained as an aqueous polymer solution or a polymer dispersion using water as the main solvent, and is hydrophilic and can be used as a precipitant for water or polybutadiene, which was previously thought to be a precipitant. Methyl alcohol, ethyl alcohol,
It dissolves in alcohols such as isopropyl alcohol, and its properties are completely different from that of polybutadiene before modification, so there are no limitations to its use in applications such as coating, coating, and painting as a polymer solution. water-soluble adhesive,
It can be used in fields such as water-soluble paints, water-absorbing materials, re-wetting adhesives, electrodeposition paints, fibers, and paper applications (antistatic, water-absorbing, moisture-absorbing processing, sticky materials for papermaking, etc.), and is It can be used by taking advantage of special characteristics not found in known water-soluble polymers (photosensitivity, imparting rubbery properties, curability through thermal crosslinking, etc.).

Claims (1)

[Claims] 1. 75% or more of the unsaturated double bonds are 1,2-bonds,
Melting point is 60-170℃ and reduced viscosity (ηsp/c)
(Tetralin solution with a concentration of 200mg/100ml, 100℃)
0.2 or more crystalline 1,2-polybutadiene or 1,4-polybutadiene in which 85% or more of unsaturated double bonds are 1,4-bonds and an average molecular weight of 50,000 or more is epoxidized; - For polybutadiene, the epoxidation rate is 5 to 45% of its unsaturated double bonds, and for the above 1,4-polybutadiene, the epoxidation rate is 5 to 60% of its unsaturated double bonds, and then these Epoxidized polybutadiene is heated in the presence of a secondary amine to open the epoxy ring by 5% or more based on the unsaturated double bonds of the polybutadiene before epoxidizing, and an amine is introduced. A method for producing a hydrophilic polymer or an aqueous solution thereof, which comprises neutralizing 5% or more of the amine structure with an acid. 2 For epoxidized 1,2-polybutadiene, 5 to 45 based on the unsaturated double bond of 1,2-polybutadiene before epoxidizing the epoxy ring.
A method for producing a hydrophilic polymer or an aqueous solution thereof according to claim 1, wherein the hydrophilic polymer is ring-opened. 3 For epoxidized 1,4-polybutadiene, 5 to 60 based on the unsaturated double bond of 1,4-polybutadiene before epoxidizing the epoxy ring.
A method for producing a hydrophilic polymer or an aqueous solution thereof according to claim 1, wherein the hydrophilic polymer is ring-opened. 4. The method for producing a hydrophilic polymer or an aqueous solution thereof according to claim 1, wherein the secondary amine is a secondary amine having 10 or less carbon atoms. 5. The method for producing a hydrophilic polymer or an aqueous solution thereof according to claim 2, wherein the secondary amine is a linear aliphatic secondary amine or a cycloaliphatic secondary amine.