JP2000344808A - Surfactant composition for emulsion polymerization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition which has a good stability in polymerization and which yields an emulsion having mechanical stability and a small particle diameter and which has a low viscosity by blending a salt of a polysulfoaryl polyoxyalkylene sulfate and a compound with an CMC in a specific range as essential components and setting the weight ratio to a specific value. SOLUTION: A surfactant composition for emulsion polymerization contains a salt of a polysulfoaryl polyoxyalkylene sulfate (A) of the formula I and a compound (B) of the formula II with an CMC in the range of 1×10-5-0.02 molL-1 as essential components in a weight ratio of A/B of 5/95 to 75/25. In the formula, R1 is H or a 1-18C monovalent aliphatic hydrocarbon; R2 is -CH2- or the like; n is 0-3; x and y are each 0-2; R3 is a monovalent aliphatic hydrocarbon; A1 and A2 are each 2-4C alkylene; p and q are each a number of 1-50 which shows the average number of moles of the alkylene oxide added; and M1 and M2 are each a monovalent cation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a surfactant composition for emulsion polymerization.

[0002]

2. Description of the Related Art
In the case of emulsion polymerization of vinyl monomers, etc., non-ionic surfactants such as polyoxyethylene alkyl ether and polyoxyethylene alkyl phenyl ether, alkyl benzene sulfonates, alkyl sulfates, and polyoxyethylene alkyl ether sulfates Anionic surfactants such as salts, polyoxyethylene alkylphenyl ether sulfates, and higher fatty acid salts have been used.

[0003] Among them, surfactants having a low critical micelle concentration (hereinafter referred to as CMC) which are effective in a small amount have been used. On the other hand, a surfactant having a high CMC was not suitable as a surfactant for emulsion polymerization.

The performance required of these surfactants for emulsion polymerization is that the stability during polymerization and the mechanical stability of the emulsion are good, the particle size of the emulsion is small, and the viscosity is low. A surfactant satisfying all of these properties has not been obtained.

[0005] An object of the present invention is to provide a surfactant composition for emulsion polymerization which satisfies all the above-mentioned properties.

[0006]

The present invention provides (a) a salt of a polysulfoarylpolyoxyalkylene sulfate represented by the general formula (I), and (b) a salt represented by the general formula (II):
A compound having a CMC in the range of 1 × 10 ^{−5 to} 0.02 mol L ⁻¹ is an essential component, and the weight ratio of the component (a) to the component (b) is (a) /
(b) Provided is a surfactant composition for emulsion polymerization, wherein the ratio is from 5/95 to 75/25.

[0007]

Embedded image

(Wherein, R ¹ is a hydrogen atom or a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms,

[0009]

Embedded image

N is a number from 0 to 3;
2, R ³ is a monovalent aliphatic hydrocarbon group, A ¹ and A ² are each an alkylene group having 2 to 4 carbon atoms, and p and q are each an average alkylene oxide addition mole number of 1 to 50. The numbers, M ¹ and M ² each represent a monovalent cation, and n y, p A ¹ and q A ² may be the same or different. )

[0011]

DETAILED DESCRIPTION OF THE INVENTION The component (a) of the present invention is a salt of a polysulfoarylpolyoxyalkylene sulfate represented by the general formula (I), and may be used alone or in combination of two or more. The component (b) is represented by the general formula (II),
MC is 1 × 10 ^{−5 to} 0.02 mol L ⁻¹ , preferably 0.001 to 0.
The compound is in the range of 01 molL ^-1 and may be used alone or in combination of two or more. In the present invention, CMC is a value measured by an electric conductivity titration method.

In the general formulas (I) and (II), R ¹ is n
When n is 0, a linear or branched monovalent aliphatic hydrocarbon group having 4 to 12 carbon atoms, and when n is 1 to 3, a hydrogen atom is preferable. x
And y are each preferably a number of 0.15 to 1. R ³ is carbon number
Preferred are 10 to 24, more preferably 11 to 18 linear or branched monovalent aliphatic hydrocarbon groups, especially alkyl groups. A ¹ and A ² are preferably an ethylene group or a propylene group. When two or more alkylene oxides are added, any of random addition and block addition may be used. Further, both of the adding methods may be combined. p and q are preferably a number of 3 to 30.
M ¹ and M ² are preferably alkali metals such as sodium and potassium; ammonium; amines such as alkanolamine.

The compound represented by the general formula (I) is obtained, for example, by adding an alkylene oxide such as ethylene oxide or propylene oxide to a phenol such as alkylphenol, distyrenated phenol or tribenzylated phenol, and then adding SO ₃ gas or the like. The sulfonating agent is preferably added at a ratio of 1 to 2 mol to 1 mol of the alkylene oxide adduct, sulfated, and neutralized with NaOH or the like.

The compound represented by the general formula (II) is, for example,
After adding an alkylene oxide such as ethylene oxide or propylene oxide to the aliphatic monohydric alcohol,
It can be produced by sulfating with a sulfonating agent such as SO ₃ gas and neutralizing with NaOH or the like.

The mixing ratio of component (a) to component (b) in the composition of the present invention is (a) / (b) = 5/95 to 75/25 by weight, preferably 10/90 to 50/50. / 50. When (a) / (b) is less than 5/95, the viscosity of the emulsion becomes high and the mechanical stability is not sufficient. If it exceeds 75/25, the particle size becomes too large, and the polymerization stability and mechanical stability are not sufficient.

Specific examples of the monomer capable of performing emulsion polymerization using the surfactant composition of the present invention include styrene, α
-Aromatic vinyl monomers such as methylstyrene and chlorostyrene: acrylates such as methyl acrylate, ethyl acrylate and butyl acrylate: methacrylates such as methyl methacrylate and ethyl methacrylate:
Vinyl halides such as vinyl chloride, vinyl bromide, vinylidene chloride and vinylidene chlorides: vinyl esters such as vinyl acetate and vinyl propionate: nitriles such as acrylonitrile and methacrylonitrile: conjugated dienes such as butadiene and isoprene And so on. These monomers may be used alone or in combination of two or more. The surfactant composition of the present invention is used in an amount of 0.1 to 20 parts by weight per 100 parts by weight of the monomer.
It is preferably used in an amount of 0.5 parts by weight, especially 0.5 to 5 parts by weight.

The surfactant composition of the present invention comprises a nonionic surfactant such as polyoxyethylene (ethylene oxide addition mole number: 0 to 100) alkyl or alkenyl (alkyl having 12 to 24 carbon atoms in the alkyl or alkenyl group) ether. They can be used together. Further, a water-soluble protective colloid or the like can be used in combination.

The emulsion polymerization conditions using the surfactant composition of the present invention are not particularly limited, and the amount of the monomer is preferably from 20 to 70% by weight, particularly preferably from 40 to 50% by weight, based on the whole system. Further, it can be used in any emulsion polymerization method such as a monomer dropping method, a monomer batch charging method and a pre-emulsion method.

[0019]

Examples 1 to 8 and Comparative Examples 1 to 9 The following components (a-1) to (a-4) as components (a) and the following components (b-1) to (b-4) as components (b) The surfactant compositions of the present invention and comparative surfactant compositions were produced in the proportions shown in Table 1 by using

(A-1): Na salt of a reaction product of 18 mol of nonylphenol ethylene oxide adduct and SO ₃ gas at a molar ratio of 1 / 1.5 (a-2): ethylene oxide of distyrenated phenol
Reactant Na with a molar ratio of 1 / 1.2 between 12 moles of adduct and SO ₃ gas
Salt (a-3): Reactant K having a molar ratio of 1 / 1.1 of ethylene oxide 25 mol adduct of tribenzylated phenol and SO ₃ gas Salt (a-4): 4 mol of propylene oxide of nonylphenol, 18 mol of ethylene oxide The molar ratio of the block adduct and SO ₃ gas is 1/2 The reactant ammonium salt (b-1): C ₁₂ H ₂₅ O (CH ₂ CH ₂ O) ₁₈ SO ₃ Na CMC 0.0046m
^{olL -1 (b-2):} C 14 H 29 O (CH 2 CH 2 O) 18 SO 3 Na CMC 0.0012m
^{olL -1 (b-3):} C 12 H 25 O (CH 2 CH 2 O) 12 SO 3 Na CMC 0.004 m
olL ^-1

[0021]

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Here, CMC was measured by the following method.

<Measurement method of CMC> 100 mL of distilled water was placed in a beaker and the electric conductivity was measured with stirring.
]. Use a surfactant solution that has been adjusted to a predetermined concentration in advance.
0.2 mL of the solution was dropped into the beaker, and the electrical conductivity was read each time the solution was dropped. Set the surfactant concentration of the titrant to x molL
^-1 , If the amount of the titrant dropped is ymL, the surfactant concentration C in the solution in the beaker is C = xy · (100 + y)
Becomes The inflection point when the electric conductivity is plotted against C is CMC (temperature 25 ° C.).

Using the obtained surfactant composition, emulsion polymerization was carried out by the monomer dropping method shown below, and the obtained polymer emulsion was evaluated by the following method. Table 1 shows the results
Shown in

(1) Polymerization Stability (Aggregate Amount) The polymer emulsion was filtered through a 200-mesh stainless steel wire gauze. Aggregates adhered to the reactor walls and stirring blades after polymerization were collected and filtered in the same manner, followed by washing with water. After 26.6kPa, 105 ℃
For 2 hours and weighed to determine the amount of aggregates. The polymerization stability was expressed in terms of% by weight of the aggregate based on the total amount of the monomers used.

(2) Mechanical stability 50 g of the polymer emulsion was weighed with a Malon stability tester at 10 k.
g, rotated at 1000 r / min for 5 minutes, the formed aggregate was filtered through a 200-mesh stainless steel wire gauze, and the filter residue was washed with water, dried and weighed at 26.6 kPa and 105 ° C. displayed.

(3) Viscosity The viscosity of the polymer emulsion was measured using a B-type viscometer at a temperature of 25 ° C. and a rotation speed of 12 r / min.

(4) Average Particle Size The average particle size of the polymer emulsion particles was measured using a dynamic light scattering particle size analyzer N-4SD manufactured by Coulter Corporation.

<Monomer Dropping Method> 316.25 g of ion-exchanged water, 8.75 g of a surfactant composition, and 0.35 g of potassium persulfate were charged into a separable flask and stirred for 30 minutes in a nitrogen stream. 0.9 g of acrylic acid and 174.1 g of butyl acrylate were mixed, and 8.75 g of the mixed monomer was charged in the above flask, and then placed in a water bath at 60 ° C. and heated. When the temperature reached 58 ° C., the remaining mixed monomer was added dropwise over 2 hours. During this time, the temperature in the flask was kept at 60 ± 2 ° C. After completion of the dropping, the mixture was aged at 60 ° C. for 3 hours, and then cooled to room temperature to obtain a polymer emulsion.

[0030]

[Table 1]

Examples 9 to 15 and Comparative Examples 10 to 17 (a-1) to (a-4) as components (a) and (b-1) to (b-4) as components (b) The surfactant compositions of the present invention and comparative compositions were produced in the proportions shown in Table 2 using the same. Using the obtained surfactant composition, emulsion polymerization was carried out by the batch charging method shown below, and the obtained polymer emulsion was evaluated by the above method. Table 2 shows the results.

<Batch Preparation Method> A separable flask was charged with 316.25 g of ion-exchanged water, 8.75 g of a surfactant composition, and 0.35 g of potassium persulfate, and stirred in a nitrogen stream for 30 minutes. After charging 175 g of styrene monomer into the above flask, the flask was placed in a water bath at 65 ° C. and heated. The temperature in the flask is about
When the temperature reached 62 ° C., the polymerization reaction started. The temperature in the flask was maintained at 65 ± 2 ° C. for 5 hours to complete the polymerization reaction, and a polymer emulsion was obtained.

[0033]

[Table 2]

Examples 16 to 27 and Comparative Examples 18 to 30 (a-1) to (a-4) as components (a) and (b-1) to (b-4) as components (b) The surfactant compositions of the present invention and comparative examples were produced in the proportions shown in Table 3 using the same. Using the obtained surfactant composition, emulsion polymerization was carried out by the following pre-emulsion method, and the obtained polymer emulsion was evaluated by the above method. Table 3 shows the results.

<Pre-emulsion method> Acrylic acid 2.5
g, butyl acrylate 123.75 g, methyl methacrylate 12
3.75 g was mixed to prepare a monomer mixture. 5.0 g of surfactant composition and 0.50 g of potassium persulfate were dissolved in 107.1 g of ion-exchanged water, and the above monomer mixture was mixed with the mixture, and the mixture was emulsified with a homomixer at 5000 r / min for 10 minutes to obtain a uniform monomer emulsion. I got 137.9 g of ion-exchanged water and 36.2 g of the above-mentioned monomer emulsion were charged into a separable flask, and stirred in a nitrogen stream for 30 minutes. Then heat the flask to 80 ° C
In a water bath and heated. Initial polymerization was performed for 30 minutes, and the remaining monomer emulsion was added dropwise over 2 hours. During this time, the temperature in the flask was kept at 80 ± 2 ° C. After completion of the dropwise addition, the mixture was aged for 3 hours at 80 ° C., and then cooled to room temperature to obtain a polymer emulsion.

[0036]

[Table 3]

[0037]

When the surfactant composition of the present invention is used as an emulsifier for emulsion polymerization, the amount of aggregates generated during the polymerization reaction is small (that is, the polymerization stability is good), and the mechanical stability of the obtained emulsion is improved. An emulsion having good properties, small particle size and low viscosity can be obtained.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Yasuo Ishii 1334 Minato, Wakayama-shi, Wakayama F Kao Research Laboratory F-term (reference) 4H003 AB31 AB35 FA30 4J005 AA04 BD06 4J011 KA04 KA23

Claims (1)

[Claims] 1. A salt of a polysulfoarylpolyoxyalkylene sulfate represented by the general formula (I):
(b) CMC represented by the general formula (II) is 1 × 10 ^{−5 to} 0.02 mol
A compound in the range of L ^{-1 as} an essential component;
A surfactant composition for emulsion polymerization, wherein the weight ratio of the component (b) is (a) / (b) = 5/95 to 75/25. Embedded image (Wherein, R ¹ is a hydrogen atom or a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms; n is a number of 0 to 3, x and y are each a number of 0 to 2, R ³ is a monovalent aliphatic hydrocarbon group, and A ¹ and A ² each have 2 carbon atoms.
Alkylene groups, p and q each represent an average number of moles of alkylene oxide, 1 to 50, M ¹ and M ²
Each represents a monovalent cation, n y, p A ¹
And the q A ² may be the same or different. )