JPS5928322B2 - Emulsifying dispersant for emulsion polymerization - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a latex emulsifying dispersant used in emulsion polymerization of synthetic rubber or synthetic resin.

More specifically, the present invention relates to an emulsifying dispersant useful for improving the stability of latex when used in combination with fatty acid soap and/or rosin acid soap used as an emulsifier during emulsion polymerization of synthetic rubber or synthetic resin. More specifically, it is biodegradable, which not only provides the latex component stability necessary in the latex manufacturing process, but also makes waste liquid treatment extremely easy after coagulating and separating the target rubber or resin component from the emulsion. This invention relates to emulsifying and dispersing agents with excellent properties. Conventional emulsifiers used in emulsion polymerization of synthetic rubber (or some synthetic resins) include asymmetric rosin acid soap, hydrogenated rosin acid soap,
Fatty acid soaps and various synthetic surfactants are used and are collectively called primary emulsifiers, and as dispersants for emulsion polymerization, formalin condensates of naphthalene sulfonic acid or alkylnaphthalene sulfonic acids, various synthetic surfactants, etc. are used. are common and are collectively called secondary emulsifiers.

However, as mentioned above, the distinction between emulsifiers and dispersants during latex synthesis is not necessarily clear; they all contribute to the production and stabilization of latex, and they are collectively called emulsifiers and dispersants. It is a kimono. Considering the effects on polymerization rate, latex stability, and rubber physical properties, it is rare that each of these emulsifying and dispersing agents is used alone, and in many cases, it is common to use an appropriate combination of each. be.

However, it is thought that the dispersant called a secondary emulsifier has the most significant effect on the stability of latex itself, and among these, naphthalene sulfonic acid or formaldehyde condensation-based substances of alkylnaphthalene sulfonic acid are considered to be indispensable. , Demol, Tagsad, Tamor, etc. This is because the naphthalene sulfonic acid/formaldehyde condensation material promotes polymer production without inhibiting polymerization, and contributes to stabilizing the produced latex. This is because most of them do not remain in the rubber and therefore have the advantage of having little effect on the physical properties of the rubber.

In general, emulsifying dispersants for emulsion polymerization, when coagulating and separating rubber or resin components from synthetic rubber or synthetic resin latex, are insolubilized themselves and mixed into the rubber or resin components, and are hardly released into the waste liquid. In some cases, it may be released as it is into the waste liquid, but in the former case, it should not have an adverse effect on the physical properties of the rubber or resin, and in the latter case, it should be easily recovered from the waste liquid, and furthermore, it should be biodegradable. The essential condition is that it is easy to accept. That is, when the rubber or resin component is coagulated and separated from the latex, fatty acid soap or rosinate salt, etc., is mostly trapped in the rubber or resin component, so only a small amount is released into the waste liquid, and only a small amount is mixed into the waste liquid. Even in this case, it can be precipitated and separated from the waste liquid by adding Ca, Mg, Fe, or Al salts or by adding an acid.

Moreover, the compound is highly biodegradable by microorganisms and does not cause any major problems even if it is contained in wastewater. Furthermore, the substance incorporated into the rubber component also has the advantage of improving the physical properties of the rubber. However, sulfonic acid-based substances, which are conventional dispersants for emulsion polymerization, are stable against changes in pH and salting out, and are usually discharged as they are into the waste liquid.
It is difficult to remove even by treatment with Mg, Fe or Al salts. This tendency is particularly noticeable for naphthalene sulfonic acid/formaldehyde condensation substances, which are poorly biodegradable and cannot be broken down even by activated sludge treatment, etc., and if they are contained in wastewater, they cannot be easily treated by normal treatment. Since it cannot be decomposed or recovered, it is highly likely to cause environmental pollution, which is why naphthalene sulfonic acid/formaldehyde condensation materials are increasingly criticized in various fields. As mentioned above, the naphthalene sulfonic acid/formaldehyde condensate accelerates polymerization during emulsion polymerization and is useful for maintaining the stability of latex during polymerization and during mixing of residual monomers, stripping, and process oil after termination of polymerization. However, during the coagulation separation and cleaning process of synthetic rubber or resin, most of it flows out into the waste liquid, and it cannot be recovered by normal methods, so extremely special and expensive processing methods such as wet combustion must be used. . Since it is a sulfonated product, SO2 or N in the exhaust gas is
It is difficult to process a2sO4, etc. In order to solve these problems, various modifications have been made to naphthalene sulfonic acid/formaldehyde condensates, but not only are they unable to provide better performance than conventional products, but they are essentially naphthalene-based, so they are not biodegradable or environmentally friendly. At present, problems such as pollution have not been resolved at all. This led to the emergence of emulsifying and dispersing agents based on a new perspective. From the above-mentioned viewpoint, the present inventors have conducted many studies on surfactants that are easy to treat or do not flow out into waste liquid, from the standpoint of latex stability, soil propagation, and waste liquid treatment, which are necessary as emulsifying dispersants for emulsion polymerization. However, as a result of repeated efforts to develop emulsifying and dispersing agents that have excellent biodegradability and do not have a negative impact on the human body or the biological environment, we have found that α,β-monounsaturated dicarboxylic acids or their anhydrides and unsaturated dicarboxylic acids or their anhydrides and The present inventors have discovered that addition reaction products with compounds having saturated hydrocarbons are effective for the purpose of the present invention, and have completed the present invention.

The addition reaction product of an α,β-monounsaturated dicarboxylic acid or anhydride thereof and a compound having an unsaturated hydrocarbon according to the present invention is an addition reaction product of an alkene and an α,β-monounsaturated dicarboxylic acid or an α,
After adding β-unsaturated dicarboxylic acid anhydride in a solvent or without a solvent at normal pressure or pressure at room temperature to 300'C by the so-called Ane addition reaction, it is directly treated with an alkali or amine (ammonia). The substituted succinic acid having an alkenyl group or its salt may be neutralized or hydrolyzed and then neutralized, and then subjected to an emulsifying and dispersing agent as a substituted succinic acid having an alkenyl group or a salt thereof. It can be used as an emulsifying dispersant as an acid or a salt thereof.

The alkene used in the present invention is suitably an alkene having 8 to 40 carbon atoms, preferably 8 to 22 carbon atoms, and cracking of petroleum paraffin, ethylene, propylene,
α-olefins obtained by polymerization of butylene etc., butadiene oligomers, or olefins obtained by dehydrogenation of petroleum paraffins are suitable, but linear hydrocarbons with less branching are suitable for biological applications. From the viewpoint of degradability, it is more suitable for the purpose of the present invention.

The α,β-monounsaturated dicarboxylic acid or anhydride used in the present invention has 4 to 12 carbon atoms, and preferable examples include maleic anhydride, maleic acid, fumaric acid, citraconic acid, and citraconic anhydride. , itaconic acid and itaconic anhydride.

In general, emulsifying and dispersing agents for emulsion polymerization not only improve the stability of the produced latex, but also play a complex role in the production process of polymer particles because they must ensure smooth polymerization. It is considered to be essentially different from a dispersant for dispersing general pigments, dyes, and other fine powders in water.

In other words, the dispersant for emulsion polymerization is dynamic.
The dispersant for fine powder can be said to be static. Interaction with the polymerization catalyst system is particularly important, and it is ideal to help decompose the catalyst into appropriate radicals. Strong materials cannot be used in emulsion polymerization systems. The compound according to the present invention is considered to have no negative effect on the catalyst system since it gives almost the same emulsion polymerization rate as the conventionally widely used naphthalene sulfonic acid monoformaldehyde condensate type compound. At the same time, the compound of the present invention does not contain any aromatic rings and is extremely biodegradable like fatty acid soaps, so even if it is contained in wastewater, it can be easily post-treated and there is no need to worry about environmental pollution. have

Furthermore, when a resin component or a rubber component is coagulated and separated from latex, even if it is incorporated into the rubber, no adverse effect on the physical properties of the rubber or resin is observed. Furthermore, conventional naphthalene sulfonic acid monoformaldehyde condensation materials have a poor color tone and tend to contaminate the produced latex, and free formalin is often a problem, but the emulsified dispersion of the present invention Depending on the agent, it is possible to overcome these drawbacks. Furthermore, although naphthalene sulfonic acid-formaldehyde condensate dispersants have been recognized to be the best latex stabilizers among known dispersants, they are still not fully satisfactory. The dispersant of the present invention successfully overcomes this problem, and is the first to obtain a dispersant that surpasses the performance of naphthalene sulfonic acid monoformaldehyde condensation product dispersants. Polymerizable monomers to which the dispersant of the present invention can be applied include acrylic acid or methacrylic acid ester,
Acrylamide, N-methylolacrylamide, N,
N-dimethylacrylamide, acrylonitrile, methacrylonitrile, styrene, vinyl chloride, chloroprene,
It includes a very wide range of monomers such as butadiene.

It is particularly effective for polystyrene, styrene-butadiene rubber, acrylonitrile-butadiene rubber, polybutadiene rubber, acrylonitrile-butadiene-styrene rubber, methacrylate-butadiene rubber, polymethacrylate-acrylonitrile, or various modified resins or emulsion polymerization synthetic rubbers or resins of rubber. It can be used as is in conventional emulsion polymerization, whether cold or hot. A feature of the present invention is that it is an emulsifying and dispersing agent with an extremely wide range. In addition, when using the dispersant according to the present invention, it can be used as a dispersant together with fatty acid soap, alkylaryl sulfonate, alkyl sulfate, etc. as an emulsifier when carrying out emulsion polymerization of the polymerizable monomer described above. In addition, the product of the present invention alone can be used as an emulsifier and a dispersant.

Next, a synthesis example of a compound used as an emulsifying dispersant for emulsion polymerization of the present invention will be shown as a reference example, and an example of its application will be shown as an example.

However, it goes without saying that the scope of the present invention is not necessarily limited to these Reference Examples and Examples. Reference example 1 1-dodecene 168.39 and granular maleic anhydride 98
．． 19 was charged into a 1 liter glass autoclave and reacted at 200° C. for 4 hours with stirring.

After the reaction was completed, the reaction product was placed in a three-necked heart-shaped flask at 180°C.
A fraction of 200° C./1 mTnHg was taken to obtain a maleic anhydride dodecene adduct 2209. Add caustic soda (95%) 69.99 and 1.5 liters of water to this and
The mixture was hydrolyzed at 70° C. for 1 hour to obtain an aqueous dicarboxylic acid sodium salt solution, then cooled to room temperature, and a large excess of acetone was added to precipitate the product, which was collected to obtain dodecel succinic acid disodium salt 2609. Reference example 21-hexadecene 224
449 and 98.19 granular maleic anhydride were charged into a 1 liter glass autoclave and reacted at 220°C for 2 hours with stirring.

After the reaction was completed, the reaction product was placed in a three-necked heart-shaped flask at 180°C.
Unreacted maleic anhydride and 1-hexadecene were distilled off at °C/5 mmHg to obtain 3109, a pale and colored solid. To this was added 819 liters of caustic soda (95%) and 1.5 liters of water, and the mixture was hydrolyzed at 60 to 70° C. for 1 hour to obtain an aqueous sodium dicarboxylic acid salt solution. Next, a large excess of acetone was added at room temperature to precipitate a substance, which was collected by F to obtain 3609 as a pale colored solid. Reference example 3 Siepron α-olefin C-151
Alkenylsuccinic acid disodium salt 3659 was obtained in the same manner as in Reference Example 2 using 2131 g of 8 (average molecular weight 213.1) and 98.19 g of granular maleic anhydride.

Reference Example 4 Alkenylsuccinic acid disodium salt 3969 was obtained in exactly the same manner as in Reference Example 2 using α-Olefin-Dialene 208 (average molecular weight 329) (manufactured by Mitsubishi Kasei Corporation) 3299 and maleic anhydride 9819.

Reference Example 5 25.299% of 1-octadecene and 98.19% of maleic anhydride were placed in a 1 liter glass autoclave and reacted at 180° C. for 6 hours with stirring.

After the reaction is complete, transfer the reaction product to a three-necked heart-shaped flask.
``C/10~5mmHg to remove unreacted substances and white solid 3
30g was obtained. To this was added 809 g of caustic soda (95%) and 15 liters of water, and the mixture was hydrolyzed at 60 to 70° C. for 1 hour to obtain an aqueous sodium dicarboxylic acid salt solution. Next, a large excess of acetone was added at room temperature to precipitate the product, and P was removed to obtain white powder octadecenyl succinic acid disodium salt 3809. Reference Example 6 ] Kikimika n-olefin 1518 (1nner01
ef! ne, MW 229.5) 2309 and maleic anhydride 9819 were placed in a 1 liter glass autoclave and reacted at 2200C for 8 hours with stirring.

After the reaction was completed, the reaction product was placed in a three-necked heart-shaped flask, and unreacted materials were distilled off under reduced pressure to obtain a pale colored solid 2609. Add 679 grams of caustic soda (95%) and 1 liter of water to this and
Hydrolysis was carried out for 1 hour. Then, a large excess of acetone was added at room temperature to precipitate the mixture, yielding a pale and colored solid monoalkenylsuccinic acid disodium salt 2759. Reference Example 7 Dissolve hexadecenyl succinic acid dinatium salt 1009 obtained in Reference Example 2 in water, add hydrochloric acid to adjust the pH to 3 or less, and extract with ethyl acetate. After drying the ethyl acetate layer with Glauber's salt, Ethyl acetate was distilled off under reduced pressure to obtain white powder 809 of hexadecenyl succinic acid.

This was hydrogenated using Raney-Ni according to a conventional method to obtain about 759 white solid - hexadecanylsuccinic acid.
This was neutralized with an equivalent amount of ammonia aqueous solution to obtain a diammonium salt. Reference example 8 2244 g of 1-hexadecene and 112 g of itaconic anhydride
9 and phenothiazine O. 29 was placed in a 1 liter glass autoclave and reacted at 170°C for 8 hours with stirring. After the reaction, 859 caustic soda (95%) and 2 liters of water were added and hydrolyzed at 80°C for 1 hour, followed by extraction with ethyl acetate. Furthermore, the aqueous layer was taken and hydrochloric acid was added to adjust the pH to 3 or less, and then extracted with ethyl acetate.The ethyl acetate layer was taken and extracted with an aqueous solution of caustic soda, and then a large excess of acetone was added to the aqueous layer to precipitate crystals, and the phenothiatin was sufficiently extracted with acetone. After removal, the residue was dried to obtain 280 fl-α carboxymethyl unsaturated fatty acid disodium salt as a light and colored powder.

Example 1 Using the compounds of the present invention obtained in Reference Examples 1 to 8 as dispersants, emulsion polymerization of styrene-butadiene rubber, which is a typical synthetic rubber, by cold rubber method sulfoxylate formulation was carried out as follows. It was carried out according to the prescription and conditions.

5±0.5 in a 600ml sealed bottle according to the above recipe
Polymerization was carried out for 6 to 8 hours while shaking at °C, and the polymerization rate was 65 ± 3.
%, a polymerization terminator Ne2 was added to stop the reaction.

[Polymerization evaluation]

Latex stability 1: The latex obtained in the above polymerization was transferred to a 500 ml three-necked colben, and steam distilled to remove unreacted butadiene and styrene (30 minutes). The mixture was filtered through a sieve, combined with the coagulum produced during polymerization, dried under reduced pressure at 80° C. for 2 hours, and then weighed, and expressed as a percentage by weight of the produced polymer.

The lower the value, the better the stability. Latex stability 2:
Latex stability (latex) obtained in Section 1
Take a predetermined amount and mix at 14,000 r at room temperature using a lab mixer.
Forced stirring was performed at pm/30 mir1, and the amount of generated aggregates was collected with a 100-mesh stainless wire mesh and washed with water.
After drying at 8°C under reduced pressure for 2 hours, it was weighed and expressed as a percentage by weight of the produced polymer.

The lower the number, the better. Particle size The average particle size was determined by a simple turbidity method.

〔result〕

It is shown in Table 1.

Example 2 Next, a comparison was made between the compounds of the present invention obtained in Reference Examples 1 to 8 and the naphthalene sulfonic acid-formalin condensation dispersant for an acrylonitrile-butyl acrylate copolymer emulsion.

[Polymerization method]

Add the emulsifying dispersant and water to a 500 ml flask equipped with a cooling tube, thermometer, dripping load, stirring bar, and nitrogen introduction tube, dissolve uniformly, and purify the system with nitrogen, then add 10% of the polymerization initiator and monomer. was added and the temperature was raised to 50°C over 10 to 15 minutes to initiate polymerization.

Furthermore, the remaining monomer was added dropwise over 1.5 hours, and the polymerization was completed after 1.5 hours of aging.The stirring speed was 400 rpm.
The coagulated product was filtered through F using a 00 mesh stainless steel mesh, dried at 80° C. for 2 hours under reduced pressure, and then weighed and expressed as weight % of the monomer charged.

The smaller the value, the better the latex stability 2: Take a predetermined amount of the emulsion and run it on a Marlon mechanical stability tester at room temperature (1000 rpm 101<g/51! Iift), and drain the resulting coagulum with a 100 mesh stainless steel screen. Weighed after drying at 80℃ under reduced pressure for 2 hours, % of produced polymer
It was shown in

The smaller the value, the better the latex viscosity Average particle diameter (μ) measured at 25°C using a B-type viscometer Compaction (%) by simple turbidity method A predetermined amount of emulsion was taken and dried overnight at 80°C under reduced pressure. It was determined from the remaining weight.

〔result〕

Shown in Table 2.

Claims (1)

[Scope of Claims] 1. Obtained by reaction of an α,β-unsaturated dicarboxylic acid having 4 to 12 carbon atoms or an anhydride of the dicarboxylic acid with an alkene having 8 to 40 carbon atoms, or by further hydrogenation. An emulsifying dispersant for emulsion polymerization of synthetic rubber or synthetic resin, which contains as an essential component a substituted succinic acid or a salt thereof having at least one alkenyl group or alkyl group. 2. The emulsifying dispersant for emulsion polymerization of synthetic rubber or synthetic resin according to claim 1, wherein the alkene is a linear alkene having 8 to 22 carbon atoms. 3 Claim 1 in which the alkene is hexadecene
An emulsifying dispersant for emulsion polymerization of synthetic rubber or synthetic resin as described in 2. 4. The emulsion for emulsion polymerization of synthetic rubber or synthetic resin according to claim 1, wherein the α,β-unsaturated dicarboxylic acid is one selected from the group consisting of maleic acid, fumaric acid, itaconic acid, and citraconic acid. Dispersant.