JP2000256549A - Surfactant composition for emulsion polymerization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a surfactant composition for emulsion polymerization which is excellent in stability at the time of polymerization and in the mechanical stability of emulsion and has small particle diameter and low viscosity. SOLUTION: This surfactant composition for emulsion polymerization is obtained by including, as the essential components, (a) a compound shown in general formula I with a critical micell concentration(CMC) in the range of 0.005 to 0.1 molL-1 and (b) a compound shown in general formula II [R2O-(A3O)r- SO3M3] with a CMC in the range of 1×10-5 to 0.02 molL-1; the molar ratio of the component (a) to the component b: a/b=(5:95) to (75/25). (In the above formulas, R1 is a bivalent aliphatic hydrocarbon group or the like; R2 is a univalent aliphatic hydrocarbon group; A1, A2 and A3 are each a 2-4C alkylene group; p and r are each 1-50; q is 0-50; and M1, M2 and M3 are each a univalent 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.

[0004] The performance required of these surfactants for emulsion polymerization is that the stability at the time of polymerization and the mechanical stability of the emulsion are good, the particle size of the emulsion is small and the viscosity is low, No problems occur, and no surfactants satisfying all of these properties have been obtained.

When emulsion polymerization is carried out using an emulsifier described in JP-A-58-154701, an emulsion having a low viscosity can be obtained, but there is a problem that the particle size of the emulsion cannot be reduced.

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

[0007]

The present invention relates to (a) a compound represented by the general formula (I) having a CMC in the range of 0.005 to 0.1 mol L ^-1 and (b) a compound represented by the general formula (II). The compound having a CMC in the range of 1 × 10 ^{−5 to} 0.02 mol L ⁻¹ is an essential component, and the molar ratio of the component (a) to the component (b) is (a) / (b) = 5 /
Provided is a surfactant composition for emulsion polymerization, wherein the surfactant composition is 95 to 75/25.

[0008]

Embedded image

R ² O— (A ³ O) _r —SO ₃ M ³ (II) (wherein R ¹ may have one oxygen atom inserted therein.
A monovalent aliphatic hydrocarbon group, R ² is a monovalent aliphatic hydrocarbon group,
A ¹ , A ² and A ³ are each an alkylene group having 2 to 4 carbon atoms,
p and r are each a number of 1 to 50 indicating an average addition mole number of alkylene oxide, q is a number of 0 to 50 indicating an average addition mole number of alkylene oxide, and M ¹ , M ² and M ³ are each monovalent. Show cations, p A ¹ , q A ² , r
A ³ may be the same or different. )

[0010]

(A) component of the present invention DETAILED DESCRIPTION OF THE INVENTION, is represented by the general formula (I), CMC is 0.005～0.1MolL ^-1, preferably compound is in the range of 0.008 to .06 molL ^-1,
A single type or a combination of two or more types may be used. The component (b) is
Represented by the general formula (II), wherein CMC is 1 × 10 ^{−5 to} 0.02 mol
L ^-1, preferably is a compound in the range of 0.001-0.01 molL ^-1, may be used alone or in combination thereof. 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 an aliphatic dihydric alcohol having 12 to 18 carbon atoms, particularly a residue obtained by removing two hydroxyl groups from 1,2-diol, A residue obtained by removing two hydroxyl groups from a glycerol monoalkyl ether of 18 and a residue obtained by removing two hydroxyl groups from a secondary dihydric alcohol having 12 to 14 carbon atoms are preferable. R ² has 10 to 24 carbon atoms,
Particularly, a linear or branched alkyl group of 12 to 16 is preferable.
A ¹ , A ² and A ³ 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. Each p
Preferably, A ¹ , A ² , A ^{3 of} / 2, q / 2, r / 2 or more are ethylene groups, and particularly preferably, A ¹ , A ² and A ³ are ethylene groups. p, q and r are preferably a number of 3 to 30. M ¹ , M ² and M ³ 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 an aliphatic dihydric alcohol or glycerin monoalkyl ether, and then adding a sulfonating agent such as SO ₃ gas. 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.

In the composition of the present invention, the components (a) and (b) are mixed in a molar ratio of (a) / (b) = 5/95 to 75/25, preferably 10/90 to 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.

[0015] Specific examples of monomers which can be subjected to 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 or alkenyl group having 12 to 24 carbon atoms) 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 20 to 70% by weight, particularly preferably 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.

[0018]

Examples 1 to 10 and Comparative Examples 1 to 6 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

[0019]

Embedded image

(A-4): Ammonium salt of a reaction product of a 1/2 (molar ratio) reaction product of an adduct of a secondary dihydric alcohol having 12 to 14 carbon atoms with an average of 20 moles of ethylene oxide and SO ₃ gas the compounds of JP example 1 described in JP ^{58-154701) CMC 0.021 molL -1 (b} -1): C 12 H 25 O (CH 2 CH 2 O) 18 SO 3 Na CMC 0.0046molL -1 (b-2): C ₁₄ H ₂₉ O (CH ₂ CH ₂ O) ₁₈ SO ₃ Na CMC 0.0012 molL ⁻¹ (b-3): C ₁₂ H ₂₅ O (CH ₂ CH ₂ O) ₁₂ SO ₃ Na CMC 0.004 mol L ⁻¹

[0021]

Embedded image

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 while stirring (the electric conductivity meter was CM-20S type of Toa Denpa Kogyo Co., Ltd., cell CG-511).
B). A surfactant solution adjusted to a predetermined concentration in advance to 0.
2 mL of the solution was dropped into the beaker, and the electrical conductivity was read each time the solution was dropped. Change the surfactant concentration of the titrant to x mol
Assuming that L ⁻¹ and the amount of the titrant dropped are ymL, the surfactant concentration C in the solution in the beaker is C = x · y / (100+
y). 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 11 to 14, Comparative Examples 7 to 10 (a-1) and (a-2) as components (a) and (b-1) and (b-2) 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 15 to 24 and Comparative Examples 11 to 15 (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.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroki Sawada 1334 Minato 1334 Minato, Wakayama City, Wakayama Pref. Hiroyuki Aizawa 1334 Minato, Wakayama City, Wakayama Prefecture Kao Corporation Research Laboratory (72) Inventor Yoshinori Mitsuda 1334 Minato, Wakayama City, Wakayama Prefecture Kao Corporation Laboratory F-term (reference) 4D077 AB14 AC01 BA01 BA03 BA07 BA13 BA20 CA03 CA13 CA15 DC02Y DC15Y DC19Y DC20Y DC54Y DC57Y DD03Y DD32Y DD33Y DE02Y DE07Y DE29Y 4J002 AC031 AC061 BC031 BC091 BC111 BD041 BD101 BD111 BF011 BF021 BG041 BG051 BG061 BG101 CH05X CH05Y FD31A 02000

Claims (1)

[Claims] 1. A compound represented by the general formula (I) having a critical micelle concentration (CMC) in the range of 0.005 to 0.1 mol L ^-1 , and (b) a compound represented by the general formula (II) Is 1 × 10 ^-5
A compound in the range of ~ 0.02 molL ^-1 as an essential component,
The molar ratio of component (a) to component (b) is: (a) / (b) = 5 / 95-7
5/25 surfactant composition for emulsion polymerization. Embedded image R ² O— (A ³ O) _r —SO ₃ M ³ (II) (wherein, R ¹ may have one oxygen atom inserted therein.
A monovalent aliphatic hydrocarbon group, R ² is a monovalent aliphatic hydrocarbon group,
A ¹ , A ² and A ³ are each an alkylene group having 2 to 4 carbon atoms,
p and r are each a number of 1 to 50 indicating an average addition mole number of alkylene oxide, q is a number of 0 to 50 indicating an average addition mole number of alkylene oxide, and M ¹ , M ² and M ³ are each monovalent. Show cations, p A ¹ , q A ² , r
A ³ may be the same or different. )