JPH0575002B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to an emulsifier for emulsion polymerization. [Prior art] Usually, in emulsion polymerization, anionic surfactants such as alkyl sulfates, alkylbenzene sulfates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl ethers, etc. are used as emulsifiers. Nonionic surfactants such as oxyethylene fatty acid esters and Pluronic surfactants are used. Emulsifiers for emulsion polymerization are not only involved in the initiation reaction and production reaction of polymerization, but also in the mechanical stability, chemical stability, freeze stability, and storage stability of the produced emulsion, and also affect the particle size of the emulsion. It is known that it has a great influence on the physical properties of the emulsion, such as viscosity and foaming properties, and the physical properties of the film, such as water resistance, weather resistance, adhesiveness, and heat resistance. [Problems to be Solved by the Invention] However, emulsions produced by emulsion polymerization using ordinary emulsifiers have high foaming caused by the emulsifier, and when the emulsion is made into a film, the emulsifier is liberated. Since it remains in the film in a state of [Means for Solving the Problems] An object of the present invention is to provide an emulsifier for emulsion polymerization which does not have the above-mentioned drawbacks and which acts as an emulsifier during polymerization and is incorporated into the polymer as a monomer. Therefore, the present invention relates to the general formula

[Formula, A is an alkylene group having 2 to 4 carbon atoms, R ₁ is hydrogen or a methyl group, and R ₂ is an alkyl group, alkenyl group, hydrocarbon or acyl group having 8 to 24 carbon atoms. , m is a number from 0 to 50,
The object of the present invention is to provide an emulsifier for emulsion polymerization having a radically polymerizable double bond in the molecule, represented by X (X is a hydrogen atom, or a nanion or anion type hydrophilic group). [Function] The emulsifier for emulsion polymerization of the present invention has a radically polymerizable double bond in its molecule, and is characterized by not only acting as an emulsifier during polymerization but also forming a chemical bond with the polymer as a monomer. . The emulsifier for emulsion polymerization of the present invention can be produced, for example, as follows. That is, the general formula

[Formula, R ₁ is a hydrogen atom or a methyl group]
Unsaturated acids represented by and the general formula

[Formula, A is an alkylene group having 2 to 4 carbon atoms, R ₂ is a hydrocarbon or acyl group such as an alkyl group, alkenyl group, or alkylaryl group having 8 to 24 carbon atoms, and m is an acyl group. 0 to 50, preferably 0 to 20) in the presence of a known catalyst such as a tertiary amine or a quaternary ammonium salt at 50 to 160°C for 3 to 20 hours. After a ring reaction, the general formula

A compound represented by the formula (wherein A, R ₁ , R ₂ and m have the same meanings as above) is obtained. The compound of general formula () corresponds to X=H in general formula (). As an example of producing a product having a nonionic group as X in the general formula (),
Adding an alkylene oxide having 2 to 4 carbon atoms to the compound of general formula () in the presence of a catalyst such as sodium hydroxide, potassium hydroxide, or boron trifluoride,
Using a pressurized reactor, react at 80 to 160℃ to obtain the general formula

A compound represented by the formula (wherein A, m, R ₁ and R ₂ have the same meanings as above, and n is a number from 1 to 100) is obtained. Examples of the alkylene oxide used include ethylene oxide, propylene oxide, butylene oxide, and the like. These may be used alone or in combination. It can also be used in the form of blocks. However, as an emulsifier, it is necessary to maintain a balance between hydrophilicity and hydrophobicity, and the type of glycidyl ether and acid used to form the hydrophobic group, the type of alkylene oxide, and the number of moles added depend on the type of monomer to be polymerized. and is selected to be compatible with the polymerization reaction. In particular, ethylene oxide is important in imparting hydrophilicity, and it is desirable to add 20 to 80 moles. An example of producing a product having an anionic group as X in the general formula () is to esterify the compound of the general formula () or () with sulfuric acid, sulfuric anhydride, chlorosulfonic acid, sulfamic acid, etc. by a conventional method. Anionized, general formula

[Chemical formula] (where A, m, R ₁ and R ₂ have the same meanings as above, l is a number from 0 to 20, M is a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or the number of carbon atoms. 1 to 4 hydroxyalkylammonium), or by converting the compound of the general formula () or () into a phosphoric acid ester using phosphorus pentoxide, polyphosphoric acid, etc. and anionizing it by a conventional method, general formula

[Chemical formula] (wherein A, m, l, R ₁ and R ₂ have the same meanings as above, M ₁ and M ₂ are hydrogen atoms, alkali metals,
A method for obtaining a compound represented by an alkaline earth metal, ammonium or hydroxyalkylammonium having 1 to 4 carbon atoms, in which M ₁ and M ₂ may be different or the same. etc. Furthermore, in the above formulas () and (), M, M ₁ and
Preferred as M ₂ are alkali metals and ammonium, and more preferred is sodium. Ethylenically unsaturated monomers that can be emulsion polymerized using the emulsifier for emulsion polymerization of the present invention include vinyl ester monomers such as vinyl acetate, acrylic acid, methyl acrylate, methyl methacrylate,
Examples include acrylic monomers such as acrylonitrile and acrylamide, aromatic monomers such as styrene, olefinic monomers such as ethylene, butadiene, and chloroprene, and halogen-containing monomers such as vinyl chloride and vinylidene chloride. The monomer used is not particularly limited to the above examples, and any known crosslinking monomer can be used to improve the monomer physical properties. When carrying out emulsion polymerization using the emulsifier for emulsion polymerization of the present invention, the reaction temperature is 0 to 100°C, and the reaction can be carried out by adding a polymerization initiator and a polymerization regulator in an inert gas. Examples of polymerization initiators include water-soluble inorganic peroxides such as hydrogen peroxide, potassium persulfate, and ammonium persulfate, azo compounds such as azobisisobutyronitrile, and organic peroxides such as benzoyl peroxide and peracetic acid. Initiators can be used, and redox polymerization may be carried out using these in combination with reducing properties such as sodium bisulfite, sodium thiosulfate, and ferrous sulfate. The use of a polymerization regulator is optional, but when used, known regulators such as mercaptans and halides can be used. The amount used when carrying out emulsion polymerization using the emulsifier for emulsion polymerization of the present invention can be varied depending on the type of polymer and the composition of monomers, but is usually 0.1
~20% by weight (based on resin emulsion solid content). Further, it is also possible to use any ordinary anionic or nonionic surfactant. [Example] The present invention will be further explained with reference to Examples below, but the present invention is not limited to the following Examples. Example 1

[Formula] (wherein R is a mixture of C ₁₂ H ₂₅ and C ₁₃ H ₂₇ )
Acrylic acid 72.1g to 318.2g glycidyl ether
g and heated to 120℃ using tributylamine as a catalyst.
and react until the acid value is almost gone. (ii) Add ethylene oxide to this reaction product using a pressure-resistant reactor to obtain an emulsifier for emulsion polymerization as an adduct of 40, 60, and 80 moles (indicated as 40EO, 60EO, and 80EO, respectively, in the table below). Ta. Example 2 186 g of nonylphenyl glycidyl ether and 72.0 g of acrylic acid are charged into a reaction vessel, heated to 120° C. using tributylamine as a catalyst, and reacted until the acid value is almost eliminated. Ethylene oxide is added to this reaction product using a pressure reactor.
Emulsifiers for emulsion polymerization were obtained as 20, 40, and 60 molar adducts. Example 3 A similar reaction was carried out using methacrylic acid in place of acrylic acid in Example 1 to obtain 60 and 80 mol adducts. Example 4 Lauryl alcohol EO adduct (EO addition mole number
The same reaction as in Example 1 was carried out using 20 moles of glycidyl ether to obtain an emulsifier for emulsion polymerization as a product of the following formula.

[C] Example 5 Lauryl alcohol EO adduct (number of moles of EO added)
The same reaction as in Example 1 was carried out using 40 moles of glycidyl ether to obtain an emulsifier for emulsion polymerization as a product of the following formula.

Example 6 200 g of the compound of Example 1-(i) was placed in a 500 ml glass four-necked flask and cooled to 0 to 5°C. 66.6 g of chlorosulfonic acid was added dropwise to this using a dropping funnel. After the dropwise addition, the mixture was stirred at the same temperature for 1 hour, and the generated HCl was removed by blowing in nitrogen.
Thereafter, the product was neutralized with an aqueous sodium hydroxide solution to obtain a product as a soda salt. Example 7 A compound obtained by using methacrylic acid instead of acrylic acid in Example 1-(i) was subjected to sulfuric acid esterification under the same conditions as in Example 6 to obtain an emulsifier for emulsion polymerization as a product. Example 8 The reaction product of nonylphenyl glycidyl ether and acrylic acid was sulfuric acid esterified by the method of Example 6 to obtain an emulsifier for emulsion polymerization. Example 9 An emulsifier for emulsion polymerization was obtained as a product by sulfuric acid esterification of the reaction product of glycidyl ether of lauryl alcohol with ethylene oxide adduct (15 mole adduct) and acrylic acid by the method of Example 6. Example 10 Nonylphenyl glycidyl ether and acrylic acid were reacted using a boron trifluoride ethyl ether chain as a catalyst, and 15 moles of ethylene oxide was added to this reaction product in a pressure-resistant reactor. The product was obtained by sulfuric acid esterification using the method described above. Example 11 200 g of the compound of Example 1-(i) was placed in a 500 ml glass four-necked flask, and 35 g of phosphorus pentoxide was added at 40°C.
was introduced. After charging, the reaction mixture was heated to 60°C for 2 hours, and further aged at 80°C for 2 hours. after that,
Neutralization with aqueous sodium hydroxide solution gave the product as a soda salt. Example 12 A product was obtained in the same manner as in Example 6 except for neutralization using an aqueous ammonia solution. Example 13 A product was obtained in the same manner as in Example 11, except that it was neutralized using an aqueous sodium hydroxide solution. Reference Example 1 (Example of use of emulsifier for emulsion polymerization) Using the emulsifier for emulsion polymerization obtained in Examples 1 to 13, an emulsion polymerization reaction was carried out using ethyl acrylate as a monomer. Regarding the obtained polymer emulsion, its solid content, mechanical stability, foamability, and water resistance of the polymer film obtained from the polymer emulsion were measured. The obtained results are the first
Shown in Table and Table 2. Polymerization method 120 g of water was charged into a reaction vessel equipped with a reflux condenser, a stirrer, a dropping funnel, and a thermometer, and the inside of the system was purged with nitrogen gas. Separately, 4 g of the emulsifier for emulsion polymerization of the present invention was dissolved in 80 g of ethyl acrylate.
8.4 g, 0.08 g of potassium persulfate, and 0.04 g of sodium bisulfite were added to the reaction vessel, and polymerization was started at 50°C. The remaining monomer/emulsifier mixture for emulsion polymerization was continuously dropped into the reactor over a period of 2 hours, and after completion of the dropwise addition, the mixture was aged for 2 hours to obtain an emulsion. Measurement/evaluation method (solid content) Accurately weigh approximately 1 g of emulsion and heat it at 105±5℃ for 2 hours.
The dry weight after drying for a period of time is measured and expressed in weight %. (Mechanical stability) 50g of emulsion was tested using a Maron method stability tester.
Kg, rotated for 5 minutes at 1000 rpm, the resulting coagulum was filtered through a 100 mesh wire mesh, the filtration residue was washed with water, dried at 105°C for 2 hours, and the weight was expressed as weight% based on the solid content. represent. (Foaming property) Dilute the emulsion twice with water, put 20ml of this diluted emulsion into a 100ml graduated test tube,
Measure the foam height when shaking vigorously up and down for 10 seconds and display it in ml. (Water resistance of film) Evaluate based on the time required for whitening a 0.2 mm polymer film by immersion in water using the following criteria: ◎: 1 day or more, ○: 1 hour or more, ×: less than 1 hour.

【table】

【table】

[Table] Reference Example 2 (Example of use of emulsifier for emulsion polymerization) Using the emulsifier for emulsion polymerization obtained in Examples 1 to 13, styrene and butyl acrylate (weight ratio 1/1)
Emulsion polymerization was carried out in the same manner as in Reference Example 1 using as a monomer. The results obtained are shown in Tables 3 and 4.

【table】

【table】

[Table] [Effects of the invention] The emulsion produced using the emulsifier for emulsion polymerization of the present invention has improved adhesiveness of the polymer film because the emulsifier molecules are chemically bonded to the polymer molecules.
It does not reduce polymer properties such as water resistance, weather resistance, and heat resistance, and foaming of the emulsion is low. In addition, after coagulating the emulsion, filtering out the polymer, and removing unreacted monomers from the filtrate by evaporation, we measured the chemical oxygen demand (COD) to measure the amount of organic matter, but it was almost zero. ,
It was found that the emulsifier for emulsion polymerization used was contained in the polymer and there was no need for wastewater treatment. Furthermore, as is clear from the solid content %, the emulsifier for emulsion polymerization of the present invention hardly behaves like a polymerization inhibitor, and hardly lowers the yield of the polymer.

Claims (1)

[Scope of Claims _] 1 General _formula or an acyl group, m is a number from 0 to 50, and X is a hydrogen atom, or a nonionic or anionic hydrophilic group), an emulsion with a radically polymerizable double bond in the molecule. Emulsifier for polymerization. 2 X in the general formula () is -(AO) _o -H (in the formula, A
is an alkylene group having 2 to 4 carbon atoms, and n is 0 to 4.
100), the emulsifier for emulsion polymerization according to claim 1. 3 In the general formula (), X is -(AO) _l -SO ₃ M (wherein A is an alkylene group having 2 to 4 carbon atoms, l
is a number from 0 to 20, and M is a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or a hydroxyalkylammonium having 1 to 4 carbon atoms. Emulsifier for use. 4 In the general formula ( _{) ,} X is [Formula] , an alkaline earth metal, ammonium or a hydroxyalkylammonium having 1 to 4 carbon atoms, and M ₁ and M ₂ may be different or the same. The emulsifier for emulsion polymerization according to item 1.