JP2001226412A - Surfactant composition for emulsion polymerization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surfactant composition for emulsion polymerization which can imparts a vinyl-based polymer emulsion excellent in polymerization stability, mechanical stability and chemical stability. SOLUTION: This surfactant composition for emulsion polymerization comprises (I) a compound having a critical micelle concentration(CMC) of 0.007 molL-1 to 0.1 molL-1 and represented by the formula R1O-(A1O)p-SO3M1, (II) a compound having a CMC not smaller than 1×10-5 moll-1 and smaller than 0.007 molL-1 and represented by the formula R2O-(A1O)q-SO3M2 and (III) a compound represented by the formula R3CH2O-(A3O)r-H in a specific content ratio wherein R1 and R2 are each a monovalent aliphatic hydrocarbon group, A1 and A2 are each a 2-4C alkylene group, p and q are each a number of 1 to 50, M1 and M2 are each a monovalent cation, R3 is a 9-13C alkyl group, A3 is a 2-4C alkylene group, r is a number of 15 to 60, and >=80% of r×A3 is ethylene group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surfactant composition for emulsion polymerization, which provides a vinyl polymer emulsion having good polymerization stability, mechanical stability and chemical stability, and emulsion polymerization of vinyl monomers. About the method.

[0002]

2. Description of the Related Art Polymer emulsions obtained by emulsion polymerization of vinyl monomers such as vinyl acetate and acrylic acid esters are directly used in the fields of paints, adhesives, adhesives, paper processing, and fiber processing. Or the polymer is widely separated and used industrially as plastic and rubber. In the emulsion polymerization, anionic surfactants such as linear alkyl sulfates, linear alkylbenzene sulfonates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkyl phenyl ether sulfates, and the like; Nonionic surfactants such as ethylene linear alkyl ether and polyoxyethylene alkylphenyl ether have been used alone or in a mixed system of anionic and nonionic surfactants.

[0003] Emulsifiers in emulsion polymerization not only affect the initiation reaction and growth reaction of the polymerization, but also the stability of the polymer emulsion during polymerization (polymerization stability), the mechanical stability of the formed polymer emulsion, and the chemical stability. Has a significant effect on chemical stability, freeze stability and storage stability. Generally, anionic surfactants have excellent polymerization stability, but have insufficient chemical stability. Nonionic surfactants are excellent in chemical stability, but insufficient in polymerization stability and need to be added in a large amount. In a polymer emulsion for a coating material to which a large amount of an inorganic pigment is added, a mixed system of an anion-nonionic surfactant has been used in order to achieve both chemical stability and polymerization stability. Conventionally, as an anionic surfactant, a critical micelle concentration (hereinafter referred to as C
MC). Meanwhile, CM
Activators with high C were not suitable as surfactants for emulsion polymerization. The performance required of these surfactants for emulsion polymerization is polymerization stability, good mechanical stability and chemical stability of the resulting polymer emulsion, small emulsion particle size, low viscosity, and environmental No problems occur, and a surfactant composition satisfying all of these properties has not been obtained.

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

[0005]

Means for Solving the Problems The present invention, (a) represented by the general formula (I), CMC is 0.007MolL ^-1 or 0.1 mol ^-1
A compound having the following range, (b) represented by the general formula (II),
MC is the 1 × 10 ^-5 molL ^-1 or more 0.007molL compound is in the range of less than ^-1, and (c) the general formula (III) compound represented by the essential components, (a) component and the component (b) Is the molar ratio of (a) / (b)
= 5/95 to 75/25, and the ratio of the total weight of the component (a) and the component (b) to the weight of the component (c) is [(a) + (b)] / (c) = 15 / 85-
Provided is a surfactant composition for emulsion polymerization having a ratio of 70/30, and a method for emulsion polymerization of a vinyl monomer using the surfactant composition.

R ¹ O- (A ¹ O) _p -SO ₃ M ¹ (I) R ² O- (A ² O) _q -SO ₃ M ² (II) R ³ CH ₂ O- (A ³ O) _r- H (III) (wherein, R ¹ and R ² are each a monovalent aliphatic hydrocarbon group,
A ¹ and A ² each represent an alkylene group having 2 to 4 carbon atoms, p and q each represent a number of 1 to 50 indicating an average addition mole number of alkylene oxide, M ¹ and M ² each represent a monovalent cation, p A ¹ and q A ² may be the same or different. R ³ is an alkyl group having 9 to 13 carbon atoms, and A ³ is a C 2 to C 2 alkyl group.
4 alkylene group, r is the number of 15 to 60 showing an average mole number of added alkylene oxide, r pieces of A ³ may be the same or different. However, 80% or more of the r A ³ is an ethylene group. )

[0007]

(A) component of the present invention DETAILED DESCRIPTION OF THE INVENTION, is represented by the general formula (I), CMC is 0.007MolL ^-1 or 0.1 mol ^-1
Hereinafter, the compound is preferably in the range of 0.01 to 0.06 mol L ⁻¹ , and may be used alone or in combination of two or more. Also
The component (b) is represented by the general formula (II) and has a CMC of 1 × 10 ⁻⁵ mol
L ^-1 or 0.007molL less than ^-1, preferably 0.001~0.005mo
It is a compound in the range of IL- ¹ and may be used alone or in combination of two or more. The component (c) is a compound represented by the general formula (III), 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), (II) and (III), R
¹ is preferably a straight-chain or branched-chain alkyl group having 7 to 11 carbon atoms, and R ² is preferably a straight-chain or branched-chain alkyl group having 12 to 24 carbon atoms, particularly 12 to 16 carbon atoms. R ³ is an alkyl group having 9 to 13 carbon atoms,
It is preferably an alkyl group containing 70% by weight or more of an alkyl group having 10 carbon atoms, more preferably 80% by weight or more, from the viewpoint of polymerization stability.

A¹And A^TwoIs an ethylene or propylene group
preferable. Addition of two or more alkylene oxides
If you do, either random addition or block addition
good. Further, both of the adding methods may be combined. It
A over p / 2, q / 2 respectively ¹, A^TwoIs an ethylene group
It is preferred, particularly preferably A¹And A^TwoIs an ethylene group
It is. p and q are preferably a number of 3 to 30. M¹And M^TwoIs
Alkali metals such as sodium and potassium; ammonium
And amines such as alkanolamines are preferred.

A ³ is 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. 80% or more of the r A ³ is an ethylene group, it is preferred that all is ethylene group. r is 15 to 60, preferably 30 to
40.

The compound represented by the general formula (I) or (II) is obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide to an aliphatic monohydric alcohol, and then adding a sulfonating agent such as SO ₃ gas. Sulphated, Na
It can be produced by neutralizing with OH or the like.

The compound represented by the formula (III) can be produced by adding an alkylene oxide to an aliphatic primary monohydric alcohol having 10 to 14 carbon atoms using a known method. For example, it can be obtained by adding an alkylene oxide to an alcohol produced by subjecting an olefin obtained by oligomerization of propylene and butene to an oxo reaction and containing 70% by weight or more of an alcohol having 11 carbon atoms. Specifically, by using an acidic ion exchange resin or alkylaluminum as a catalyst, 2 mol of propylene and 1 mol of butene are oligomerized to synthesize an olefin having an average of 10 carbon atoms, and this is subjected to an oxo reaction-hydrogenation. Oxo alcohol containing at least 70% by weight of an alcohol having 11 carbon atoms, and further adding an alkylene oxide to the oxo alcohol.

The mixing ratio of component (a) to component (b) in the composition of the present invention is (a) / (b) = 5/95 to 75/25, preferably 10/90 to 50, in molar ratio. / 50. If (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.
The ratio of the total weight of the components (a) and (b) to the weight of the component (c) is
[(A) + (b)] / (c) = 15/85 to 70/30, preferably 30/70 to 70/30. [(A) + (b)] / (c) is 15/85
When it is less than 70, the polymerization stability is insufficient, and when it exceeds 70/30, the chemical stability becomes insufficient.

[0015] Specific examples of monomers capable of undergoing emulsion polymerization using the surfactant composition of the present invention include styrene and styrene.
aromatic vinyl monomers such as α-methylstyrene and chlorostyrene; acrylates such as methyl acrylate, ethyl acrylate and butyl acrylate; methacrylates such as methyl methacrylate and ethyl methacrylate; vinyl chloride, odor Vinyl halides such as vinyl chloride and vinylidene chloride and vinylidene halides; vinyl esters such as vinyl acetate and vinyl propionate; nitriles such as acrylonitrile and methacrylonitrile; and conjugated dienes such as butadiene and isoprene. These monomers may be polymerized alone or in combination of two or more. The amount of the vinyl monomer used is preferably 40 to 60% by weight based on the whole system.

The surfactant composition of the present invention comprises a monomer 100
It is preferably used in an amount of 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight, particularly preferably 0.5 to 5 parts by weight with respect to parts by weight.

In the emulsion polymerization of the present invention, polyvinyl alcohol is used.
Water-soluble protective colloids such as alcohol can be used together
You. The initiator used in the emulsion polymerization of the present invention is K_Two(S_TwoO₈)_Two,
(NH_Four) _Two(S_TwoO₈)_TwoAnd the like are preferred.

As a method for adding a monomer in the emulsion polymerization of the present invention, a monomer dropping method, a pre-emulsion method and the like can be used, but a pre-emulsion method is preferred from the viewpoint of polymerization stability. The dripping time is 1 to 8 hours and the aging time is 1
~ 5 hours are preferred. The polymerization temperature is adjusted depending on the decomposition temperature of the initiator. In the case of persulfate, the polymerization temperature is preferably from 70 to 80C.

[0019]

EXAMPLES In the examples,% is% by weight unless otherwise specified.

Examples 1 to 23 and Comparative Examples 1 to 12 The following components (a) to (a-3) and (b)
(b-1) to (b-4), the following (c-1) to (c-6) as the component (c), and the following (d-1) as the comparative nonionic surfactant (component (d)) ~ (D
-2) was blended at the ratios shown in Tables 1 and 2 to prepare surfactant compositions of the present invention and comparative surfactants.

(A-1): C ₈ H ₁₇ O (CH ₂ CH ₂ O) ₁₈ SO ₃ Na CMC 0.029 molL ⁻¹ (a-2): iC ₉ H ₁₉ O (CH ₂ CH ₂ O) ₁₈ SO ₃ Na CMC 0.021 molL ^-1 (a-3): iC ₁₁ H ₂₃ O (CH ₂ CH ₂ O) ₁₈ SO ₃ Na CMC 0.012 mol L ^-1 (b-1): C ₁₂ H ₂₅ O (CH ₂ CH ₂ O) ₁₈ SO ₃ Na CMC 0.0046 molL ^-1 (b-2): C ₁₄ H ₂₉ O (CH ₂ CH ₂ O) ₁₈ SO ₃ Na CMC 0.0012 mol L ^-1 (b-3): C ₁₂ H ₂₅ O ( CH ₂ CH ₂ O) ₁₂ SO ₃ Na CMC 0.0040molL ^-1

[0022]

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(C-1): 35 moles of ethylene oxide adduct of propylene / butene-derived oxo alcohol (c-2): 50 moles of ethylene oxide adduct of propylene / butene-derived oxo alcohol (c- 3): 18 moles of ethylene oxide adduct of oxo alcohol of decene derived from propylene / butene (c-4): 35 moles of ethylene oxide of n-decanol (c-5): 50 moles of ethylene oxide of n-dodecanol Product (c-6): ethylene oxide 35 of n-tetradecanol
Molar adduct (d-1): 18 mol adduct of ethylene oxide of oxo alcohol of octene derived from butene (d-2): 35 mol adduct of ethylene oxide of oleyl alcohol 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 KK, cell CG-511).
B). A surfactant solution adjusted to a predetermined concentration in advance to 0.
2 mL of the solution was dropped into a 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 this surfactant composition, emulsion polymerization was carried out by the following method, and the performance was evaluated by the following method. The results are shown in Tables 1 and 2.

<Emulsion polymerization method> A monomer mixture was prepared by mixing 2.8 g of acrylic acid, 136.1 g of butyl acrylate, and 136.1 g of methyl methacrylate. Ion exchange water 117.9
8.25 g of the surfactant composition and 0.55 g of potassium persulfate were dissolved in g, and the above monomer mixture was mixed and emulsified at 5,000 r / min × 10 minutes with a homomixer to obtain a uniform monomer emulsion.

In a separable flask, add 135.4 ion-exchanged water.
g, and 36.5 g of the above-mentioned monomer emulsion, and stirred in a nitrogen stream for 15 minutes. Next, while stirring in a nitrogen stream,
The temperature was raised in a water bath at 80 ° C. Initial polymerization was carried out for 30 minutes, and 328.6 g of a monomer emulsion was added dropwise over 2 hours. During this time, the temperature in the flask was kept at 80 ± 2 ° C. 3 hours after dropping
After keeping at 80 ° C. and aging, it was cooled to room temperature to obtain a polymer emulsion.

<Performance Evaluation Method> (1) Polymerization Stability (Aggregate Amount) The polymer emulsion was filtered through a 200-mesh stainless steel wire mesh, and aggregates adhered to the reactor wall, stirring blades, etc. after polymerization were collected and the same. After washing with water, the mixture was dried and weighed at 26.6 kPa and 105 ° C. for 2 hours 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 neutralized with 25% NH ₃ water was rotated by a Malon stability tester under the conditions of 10 kgf and 1000 r / min for 5 minutes. The mixture was filtered through a stainless steel wire gauze, and the residue was washed with water, dried and weighed at 26.6 kPa and 105 ° C. for 2 hours.

(3) Chemical stability The polymer emulsion is prepared by ion-exchanged water with a polymer concentration of 3
% And titrated with a ¹ mol L ^{- 1} aqueous solution of calcium chloride to determine the concentration at which aggregates were formed.

(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.

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

[0033]

[Table 1]

[0034]

[Table 2]

Examples 24 to 30, Comparative Examples 13 to 19 (a) as the component (a-1), (b) as the component (b-1),
As the component (c), the components (c-1) to (c-5), and the comparative nonionic surfactant (component (d)) using the components (d-1) and (d-2) as components,
The compositions shown in Table 3 were blended to prepare surfactant compositions of the present invention and comparative examples. Using this surfactant composition, emulsion polymerization was carried out by the following method, and the performance was evaluated by the above method. Table 3 shows the results.

<Emulsion polymerization method> A monomer mixture was prepared by mixing 8.3 g of acrylic acid, 133.4 g of butyl acrylate, and 133.4 g of styrene. 8.25 g of the surfactant composition and 0.55 g of potassium persulfate were dissolved in 117.9 g of ion-exchanged water, and the above monomer mixture was mixed.
The mixture was emulsified for min × 10 minutes to obtain a uniform monomer emulsion.

In a separable flask, add 135.4 ion-exchanged water.
g and the above-mentioned monomer emulsion 14.6 g were charged and stirred in a nitrogen stream for 15 minutes. Next, while stirring in a nitrogen stream, 80
The mixture was placed in a water bath at ℃ and the temperature was raised. Initial polymerization was performed for 30 minutes, and 350.5 g of a monomer emulsion was added dropwise over 2 hours. During this time, the temperature in the flask was kept at 80 ± 2 ° C. 3 hours after dropping 80
After the mixture was kept at ℃ and aged, it was cooled to room temperature to obtain a polymer emulsion.

[0038]

[Table 3]

[0039]

When the surfactant composition of the present invention is used for emulsion polymerization, a vinyl polymer emulsion having good polymerization stability, mechanical stability and chemical stability, small particle size and low viscosity can be obtained. Can be

Claims (2)

[Claims] 1. A (a) represented by the general formula (I), a compound critical micelle concentration (CMC) in the range of 0.007MolL ^-1 or 0.1 mol ^-1 or less, the table in (b) the general formula (II) And CMC is 1
× 10 ^-5 molL compound is in the range of less than ^-1 or more 0.007MolL ^-1, and (c) a compound represented by the general formula (III) as essential components, the molar ratio of component (a) and component (b) Where (a) / (b) = 5/95
7575/25, and the ratio of the total weight of the components (a) and (b) to the weight of the component (c) is [(a) + (b)] / (c) = 15 / 85-70 / 30
A surfactant composition for emulsion polymerization. R ¹ O- (A ¹ O) _p -SO ₃ M ¹ (I) R ² O- (A ² O) _q -SO ₃ M ² (II) R ³ CH ₂ O- (A ³ O) _r -H (III) (wherein, R ¹ and R ² are each a monovalent aliphatic hydrocarbon group,
A ¹ and A ² each represent an alkylene group having 2 to 4 carbon atoms, p and q each represent a number of 1 to 50 indicating an average addition mole number of alkylene oxide, M ¹ and M ² each represent a monovalent cation, p A ¹ and q A ² may be the same or different. R ³ is an alkyl group having 9 to 13 carbon atoms, and A ³ is a C 2 to C 2 alkyl group.
4 alkylene group, r is the number of 15 to 60 showing an average mole number of added alkylene oxide, r pieces of A ³ may be the same or different. However, 80% or more of the r A ³ is an ethylene group. ) 2. A method for emulsion polymerization of a vinyl monomer using the surfactant composition according to claim 1.