JP2002179713A - Surfactant composition for emulsion polymerization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surfactant composition for emulsion polymerization having good stability of a polymer emulsion during polymerization or mechanical stability of a produced polymer emulsion, and a method of emulsion polymerization of a vinyl monomer. . A surfactant composition for emulsion polymerization containing a compound represented by the formula (I) as an essential component, and a method for emulsion polymerization of a vinyl monomer using the surfactant composition for emulsion polymerization. RCH ₂ O— (EO) _n —H (I) (wherein, R represents an alkyl group having an alkyl group having 10 carbon atoms of 70% by weight or more and an average number of methyl groups of 3 or more; The ethylene group, n is a number of 6 or more and less than 15 indicating the average number of added moles of the oxyethylene 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 gives a vinyl polymer emulsion having good polymerization stability and mechanical stability, and a method for emulsion polymerization of vinyl monomers.

[0002]

2. Description of the Related Art Polymer emulsions obtained by emulsion polymerization of vinyl monomers such as vinyl acetate, acrylates and styrene are blended as they are to form paints, adhesives, paper processing agents, fibers and the like. It is widely and industrially used as a raw material for plastics and rubber in the field of processing agents and the like, or as a polymer after being separated.
In the emulsion polymerization, as an emulsifier, anionic surfactants such as a linear alkyl sulfate ester salt, a linear alkyl benzene sulfonate salt, and a polyoxyethylene alkyl ether sulfate salt; and a polyoxyethylene linear alkyl ether and a polyoxyethylene alkyl. Nonionic surfactants such as phenyl ether are used alone or in a mixed system of anionic and nonionic surfactants.

[0003] Emulsifiers in emulsion polymerization not only affect the initiation reaction and the growth reaction of the polymerization, but also the stability of the polymer emulsion during the polymerization, and further, the mechanical stability, chemical stability, and the like of the formed polymer emulsion. It has a great effect on freezing stability and storage stability. JP-A-52-3
No. 676 discloses an invention in which a polyoxyethylene branched alkyl ether is used as a surfactant for emulsion polymerization of a vinyl monomer. However, the stability of a polymer emulsion during polymerization or the mechanical The objective stability was not enough.

[0004] An object of the present invention is to provide a surfactant composition for emulsion polymerization, which has good stability of a polymer emulsion during polymerization or mechanical stability of a formed polymer emulsion, and a method of emulsion polymerization of a vinyl monomer. Is to do.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a surfactant composition for emulsion polymerization comprising a compound represented by the formula (I) (hereinafter abbreviated as compound (I)) as an essential component, and this emulsion polymerization. Polymerization method of a vinyl monomer using a surfactant composition for use.

RCH ₂ O— (EO) _n —H (I) (wherein R represents an alkyl group having an alkyl group having 10 carbon atoms of 70% by weight or more and an average number of methyl groups of 3 or more; EO is an oxyethylene group, and n is a number of 6 or more and less than 15 indicating the average number of added moles of the oxyethylene group.)

[0007]

DETAILED DESCRIPTION OF THE INVENTION In the formula (I), an alkyl group R
Has a ratio of an alkyl group having 10 carbon atoms of 70% by weight or more, preferably 80% by weight or more, from the viewpoint of polymerization and mechanical stability of the polymer emulsion. The average number of methyl groups of the alkyl group R is 3 or more, preferably 3 to 5,
Particularly preferred is 3-4. n is a number indicating the average number of moles of oxyethylene groups added, and is from 6 to less than 15, preferably 7 to 12, from the viewpoint of the stability of the polymer emulsion. The average number of methyl groups of the alkyl group R is ¹ H-
It can be determined using NMR.

The compound (I) can be produced by a known method, for example, an alcohol having 11 carbon atoms produced by an oxo reaction of an olefin obtained by oligomerization of propylene and butene. It can be obtained by adding ethylene oxide to an alcohol containing 70% by weight or more. Specifically, an olefin having an average carbon number of 10 is synthesized by oligomerizing 2 mol of propylene and 1 mol of butene using an acidic ion exchange resin or alkylaluminum as a catalyst, and then subjecting this to oxo reaction-hydrogenation. Oxo alcohol containing 70% by weight or more of an alcohol having 11 carbon atoms, and further obtained by adding ethylene oxide to the oxo alcohol. For the addition of ethylene oxide, ordinary alkali metal compounds (potassium hydroxide, sodium methoxide, etc.) can be used.

The content of compound (I) in the surfactant composition of the present invention is preferably from 10 to 100% by weight, particularly preferably from 20 to 85% by weight.

[0010] The surfactant composition of the present invention preferably contains an anionic surfactant and / or a nonionic surfactant having an HLB of 16 or more other than the compound (I). The content of the anionic surfactant is from 15 to 15 from the viewpoint of polymerization stability.
70% by weight is preferred, and 15 to 40% by weight is particularly preferred. Nonionic surfactants having an HLB of 16 or more other than the compound (I) are particularly effective for improving the chemical stability of the polymer emulsion, and the content thereof is preferably 15 to 60% by weight. Further, the more preferable range of HLB is 17-1.
9 Here, HLB is determined by the Griffin method.

Furthermore, the surfactant composition of the present invention comprises (a) 20 to 85% by weight of the compound (I), (b) 15 to 40% by weight of the anionic surfactant, and (c) the compound (c). Those containing a nonionic surfactant having an HLB of 16 or more other than (I) at a ratio of (a) / (c) (weight ratio) of 100/0 to 40/60 are particularly preferable.

Examples of the anionic surfactant used in the present invention include linear alkyl sulfates, linear alkyl benzene sulfonates, polyoxyethylene alkyl ether sulfates, and polyoxyethylene alkyl phenyl ether sulfates. Can be illustrated.

The nonionic surfactant having an HLB of 16 or more other than the compound (I) used in the present invention includes polyoxyethylene alkyl ethers (HLBs) such as polyoxyethylene lauryl ether (17 or more moles of EO addition).
16 or more), polyoxyethylene alkylphenyl ether (HLB 16 or more) such as polyoxyethylene nonylphenyl ether (EO addition number 20 or more), distyrenated phenol ethoxylate (HLB 16 or more),
Tribenzylated phenol ethoxylate (HLB16
And the like), but polyoxyethylene alkyl ether (HLB 16 or more) is preferable. Also, formula (I)
A compound represented by the formula (1) wherein n is 15 or more may be used.

The method for emulsion polymerization of a vinyl monomer according to the present invention is a method for emulsion-polymerizing a vinyl monomer using the surfactant composition according to the present invention. In the emulsion polymerization, the amount of the surfactant composition used is preferably 0.1 to 10% by weight based on the total amount of the vinyl monomer.

The vinyl monomers used in the present invention include aromatic vinyl monomers such as styrene, α-methylstyrene and chlorostyrene; ethylene, propylene,
Olefin monomers such as butene, 1-hexene and 1-octene; conjugated dienes such as butadiene and isoprene;
Methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid 2
-(Meth) acrylates such as ethylhexyl; vinyl halides and vinylidenes such as vinyl chloride, vinyl bromide and vinylidene chloride; vinyl acetate, vinyl propionate, branched vinyl carboxylate (Shell Japan Co., Ltd.'s Vova 11 etc.) ) And other vinyl esters; (meth)
And nitriles such as acrylonitrile. These monomers may be polymerized alone or copolymerized. If necessary, a water-soluble monomer such as acrylic acid (salt), methacrylic acid (salt), 2-hydroxyethyl methacrylate, or a monomer having a functional group may be copolymerized for modification. The amount of the vinyl monomer to be used is preferably 40 to 60% by weight based on the whole system.

The initiator used in the emulsion polymerization of the present invention is preferably a persulfate such as potassium persulfate, sodium persulfate or ammonium persulfate.

The method of adding the monomer includes a monomer dropping method,
Alternatively, a pre-emulsion method can be used,
The pre-emulsion method is preferred from the viewpoint of polymerization stability. The dropping time is preferably 1 to 8 hours, and the aging time is preferably 1 to 5 hours. The polymerization temperature is adjusted depending on the decomposition temperature of the initiator, but in the case of persulfate, it is preferably from 70 to 80C.

As a polymerization stabilizer other than the surfactant composition of the present invention, a protective colloid such as polyvinyl alcohol, 2-hydroxyethylcellulose, polyvinylpyrrolidone and a water-soluble polyurethane compound may be used in combination.

[0019]

EXAMPLES The percentages in the examples are percentages by weight unless otherwise specified.

Examples 1 to 5 and Comparative Examples 1 to 7 A-1 and A-2 in Table 1 as compound (I), B-1 to B-6 in Table 1 as comparative nonionic surfactants, Surfactant other than compound (I) and HL other than compound (I)
As a nonionic surfactant of B16 or more, C-1 to C-2 in Table 2
C-5 was used in the proportions shown in Table 3 to prepare surfactant compositions of the present invention and comparative examples. Using this surfactant composition, emulsion polymerization was carried out by the method shown below, and the performance was evaluated. Table 3 shows the results.

<Emulsion polymerization method> 2.5 g of acrylic acid, 123.75 g of butyl acrylate, methyl methacrylate 12
3.75 g was mixed to prepare a monomer mixture. 5.0 g of a surfactant composition and 0.50 g of potassium persulfate were dissolved in 107.1 g of ion-exchanged water, and the above monomer mixture and a homomixer (TK HOMO MIXER: manufactured by Tokushu Kika Kogyo) were used for 5000 g. The mixture was mixed at a revolution / minute for 10 minutes to obtain a uniform monomer emulsion.

Ion-exchanged water 138 is placed in a separable flask.
g and 39 g of the above-mentioned monomer emulsion, and the mixture was heated to 80 ° C. in a water bath for 20 minutes while stirring under a nitrogen stream.
Next, 316 g of the remaining monomer emulsion was added dropwise over 3 hours. During this time, the temperature in the flask was kept at 80 ° C. After completion of the dropwise addition, the mixture was kept at 80 ° C. for 2 hours to complete the polymerization, and then cooled to room temperature to obtain a polymer emulsion.

<Performance Evaluation Method> (1) Polymerization Stability The above polymer emulsion was filtered through a 200-mesh stainless steel wire mesh, and aggregates adhered to the reactor wall after polymerization, the stirring blades, etc. were collected. It filtered similarly. After washing with water, it was dried at 26.6 kPa and 105 ° C. for 2 hours, weighed, and the amount of aggregates was measured. 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 The filtered polymer emulsion was neutralized with aqueous ammonia to adjust the pH to 8.5. Take 50 g of the neutralized polymer emulsion, and apply a load of 1 with a Malon-type stability tester.
The mixture was stirred under the conditions of 0 kg, 1000 rotations / minute, and 5 minutes. The formed aggregates were collected by filtration with a stainless steel wire net, washed with water, dried at 26.6 kPa and 105 ° C., and weighed. Mechanical stability was expressed in weight percent of agglomerate relative to polymer.

(3) Average particle size The above neutralized polymer emulsion is measured by a dynamic light scattering method N-4PLUS of Coulter Co.
Was used to determine the average particle size.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

[Table 3]

[0029]

When the surfactant composition of the present invention is used for emulsion polymerization, a polymer emulsion having good polymerization stability and excellent mechanical stability can be obtained.

Claims (4)

[Claims] 1. A surfactant composition for emulsion polymerization comprising a compound represented by the formula (I) as an essential component. RCH ₂ O— (EO) _n —H (I) (wherein, R represents an alkyl group having an alkyl group having 10 carbon atoms of 70% by weight or more and an average number of methyl groups of 3 or more; The ethylene group and n are 6 or more and less than 15 indicating the average number of added moles of the oxyethylene group.) (A) converting the compound represented by the formula (I) to 20
８５85% by weight, (b) 15-40 anionic surfactant
% By weight, and (c) H other than the compound represented by the formula (I)
(A) / (c)
The surfactant composition according to claim 1, which is contained at a ratio (weight ratio) of 100/0 to 40/60. 3. An alcohol produced by subjecting an olefin obtained by oligomerization of propylene and butene to an oxo reaction, wherein the compound represented by the formula (I) contains 70% or more of an alcohol having 11 carbon atoms. 2. A compound obtained by adding ethylene oxide to a compound.
Or the surfactant composition according to 2. 4. An emulsion polymerization method for a vinyl monomer using the surfactant composition according to claim 1.