JP2000344807A - Novel surfactant for emulsion polymerization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a novel phosphate-based surfactant for emulsion polymerization which can improve the water resistance of synthetic resins and which can be easily obtained by reacting a polyoxyalkylene alkylcyclohexyl ether and a phosphorylating agent such as phosphoric anhydride. SOLUTION: A surfactant for emulsion polymerization contains a phosphate of the formula. R is a 6-12C alkyl group; A is an ethylene group and/or a propylene group (with the proviso that compounds with all A's being propylene groups are excluded); n is an integer of 1-50; l+m=3 and l is 1 or 2 and m is 1 or 2; and M is H, an alkali metal atom, an alkaline earth metal atom, an alkanolamine residue or NH4. Although the amount of this novel surfactant for emulsion polymerization to be used depends on the type of monomers, the surfactant is generally used in the range of 0.1-10 wt.% based on the total amount of the monomers and preferably in the range of 0.3-5 wt.% in view of effects and economics. Other anionic or nonionic surfactants may be concurrently used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention provides a novel synthetic resin which has less influence on the environment and has excellent water resistance as compared with conventional surfactants for emulsion polymerization, especially when used in emulsion polymerization. It relates to a surfactant for emulsion polymerization.

[0002]

2. Description of the Related Art Conventionally, acrylic resins such as polyalkyl methacrylates, styrene resins such as ABS resins, synthetic rubbers, vinyl chloride resins and the like have been produced by a so-called emulsion polymerization method. As the emulsifier used, anionic surfactants such as alkyl benzene sulfonate, potassium rosinate, and alkyl sulfate, and nonionic surfactants such as polyoxyethylene alkyl ether and polyoxyethylene alkyl phenyl ether are generally used. I have. However, a synthetic resin obtained from a synthetic resin emulsion produced using the above surfactant as an emulsifier has problems such as poor water resistance and poor adhesion. In recent years, paints have been shifted from solvent type to emulsion type due to environmental problems and safety problems, and improvement of the above-mentioned problems has been emphasized in synthetic resin emulsions for paints.

[0003]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a surfactant for emulsion polymerization for producing a synthetic resin excellent in water resistance, having a small influence on the environment by having the above structure. The challenge is to provide.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, the use of a surfactant for emulsion polymerization having a specific structure in the emulsion polymerization has an effect on the environment. The present inventors have found that a synthetic resin having a low water resistance and excellent water resistance can be obtained, and have reached the present invention. That is, the present invention provides the following general formula (1)

Embedded image (However, R is an alkyl group having 6 to 12 carbon atoms, A is an ethylene group and / or a propylene group (however, a propylene group alone is not included), n is an integer of 1 to 50, l
+ M = 3 and l = 1 or 2, m = 1 or 2,
M is a surfactant for emulsion polymerization containing a compound represented by hydrogen atom, alkali metal atom, alkaline earth metal atom, alkanolamine residue or NH ₄ ). Hereinafter, the present invention will be described in detail.

In the present invention, R represented by the general formula (1) is an alkyl group having 6 to 12 carbon atoms, such as hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl and the like. Is exemplified.

Further,-(AO) n- in the general formula (1)
The part indicates a polyalkylene glycol chain obtained by addition polymerization of ethylene oxide and / or propylene oxide. The polymerization number n is in the range of 1 to 50. In the case of ethylene oxide alone, n is preferably in the range of 5 to 10, and in the case of addition copolymerization of ethylene oxide and propylene oxide, n is in the range of 5 to 15 and , Ethylene oxide / propylene oxide = 5/1 to 1 /
The addition polymerization is preferably performed at a molar ratio of 1. The method of addition copolymerization of ethylene oxide and propylene oxide does not change effectively whether it is random or block.

In the general formula (1), M is a hydrogen atom, an alkali metal atom such as lithium, sodium or potassium, an alkaline earth metal atom such as magnesium or calcium (however, the alkaline earth metal atom is usually divalent). From, 1 /
2), ammonium ammonium, monomethylamine,
Ammonium of alkylamine such as dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monopropylamine and dipropylamine or ammonium of alkanolamine such as monoethanolamine, diethanolamine, triethanolamine, methyldiethanolamine and ethyldiethanolamine.

The compound of the general formula (1) relating to the present study is
A novel phosphate-type emulsion polymerization surfactant which can be easily obtained by reacting a polyoxyalkylene alkylcyclohexyl ether with a phosphorylating agent such as phosphoric anhydride. The method of phosphorylation may be performed by a known method.

Further, as monomers applicable to various emulsion polymerizations using the novel surfactant for emulsion polymerization according to the present invention, for example, acrylic acid, methyl acrylate, butyl acrylate, methyl methacrylate, acrylonitrile,
Examples include acrylic monomers such as acrylamide, aromatic monomers such as styrene, and olefin monomers such as ethylene, butadiene, chloroprene, vinyl chloride, and vinylidene chloride, but are not limited to these monomers. As the polymerization initiator, for example, known initiators such as hydrogen peroxide, potassium persulfate, ammonium persulfate, azobisisobutylnitrile and benzoyl peroxide can be used. Redox polymerization may be performed using a reducing substance such as sodium hydrogen sulfite, sodium thiosulfate, and ferrous sulfate. The amount of the novel emulsion polymerization surfactant of the present invention depends on the type of monomer,
Usually, it is in the range of 0.1 to 10% by weight, preferably 0.3 to 5% by weight, based on all monomers. Further, another anionic or nonionic surfactant may be used in combination.

The novel surfactant for emulsion polymerization according to the present invention has less influence on the environment and is superior in water resistance of the resin obtained by polymerization as compared with the conventionally proposed compounds. Although it has not been completely elucidated, it is presumed to be due to the following reasons. That is, the novel emulsion polymerization surfactant according to the present invention is characterized in that it has an alkylcyclohexyl group in the hydrophobic group, and it is considered that this exhibits the desired effect. . Next, the present invention will be described in detail with reference to examples. However, the present invention is not limited to the following examples unless departing from the gist of the present invention.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Synthesis Example of Compound of the Present Invention Synthesis Example 1 578 g (1 mol) of poly (8 mol) oxyethylene nonylcyclohexyl ether was charged into a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, and a small amount of N ₂ gas was introduced. After the temperature was raised to 40 ° C., 71 g (0.5 mol) of phosphoric anhydride was added over about 15 minutes while maintaining the temperature at 40 to 60 ° C.,
Thereafter, the reaction was carried out at the same temperature for 3 hours. Next, after adding 9 g of ion-exchanged water, the temperature was raised to 80 ° C. and the mixture was aged for 3 hours. Thereafter, the resultant was neutralized with an aqueous ammonia solution to obtain a compound (1) of the present invention.

Synthetic Examples 2 to 8 According to Synthetic Example 1, compounds (2) to (8) of this research product were obtained. Details are shown in Table 1.

[0013]

[Table 1]

2. Example 1 In a reaction vessel equipped with a stirrer, a reflux condenser, a thermometer and a dropping funnel, 430 g of ion-exchanged water and the compound (1) of the present invention were added.
6 g was charged, and the inside of the system was replaced with nitrogen gas. Separately, 150 g of methyl methacrylate and 150 g of butyl acrylate were mixed, and a solution obtained by dissolving 0.6 g of ammonium persulfate in 60 g of the mixed monomer and 20 g of ion-exchanged water was added to the reaction vessel. Was. From 10 minutes after the start of the polymerization, the remaining mixed monomer was added dropwise over 3 hours, and the mixture was aged for 1 hour to obtain a synthetic resin emulsion.
The obtained synthetic resin emulsion was evaluated for the amount of agglomerates, surface tension, foamability, and water resistance of a film formed from the emulsion. Table 2 shows the results.

Examples 2 to 8 Emulsions were prepared in the same manner as in Example 1, and the same evaluation was carried out. The results are shown in Table 2.

Comparative Examples A to C In the same manner as in Example 1, as an emulsifier, sodium alkylbenzene sulfonate (hard type) (Comparative Example A), poly (9 mol) sodium oxyethylene nonylphenyl ether phosphate (Comparative Example B), And poly (40 mol) oxyethylene nonyl phenyl ether (Comparative Example C)
A synthetic resin emulsion was obtained. The same evaluation as in Example 1 was performed for this synthetic resin emulsion, and the results are shown in Table 2.

[0017]

[Table 2]

Measurement / Evaluation Method (1) Amount of Aggregate The emulsion was filtered with a 100 mesh nylon cloth, the residue on the nylon cloth was dried at 105 ° C., and the weight was measured and expressed as a percentage of the total monomer. (2) Surface tension Measured by Wilhelmy method. (3) Foaming property A solution obtained by diluting the emulsion twice with ion-exchanged water is
50 ml was taken in a measuring cylinder having a 00 ml stopper, shaken 20 times, and immediately after standing, 1 minute and 5 minutes later, the amount of foam was measured. (4) Water resistance A 0.1 mm thick film was formed on a glass plate, and the time until whitening when immersed in water was indicated.

[0019]

The novel surfactant for emulsion polymerization of the present invention comprises:
By having an alkylcyclohexyl group in the hydrophobic group, there is little effect on the environment, and as shown in Table 2, by using a synthetic resin emulsion by the emulsion polymerization method when making it, it is extremely water-resistant. An excellent synthetic resin can be provided.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D077 AB14 AC01 BA07 BA13 DC02X DC03X DC19X DC19Z DC67X DC67Z DD03X DD04X DD05X DD32X DD32Z DD33X DD33Z DE02X DE03X DE07X DE32X 4J011 KA05

Claims (1)

[Claims] 1. A compound represented by the following general formula (1): (However, R is an alkyl group having 6 to 12 carbon atoms, A is an ethylene group and / or a propylene group (however, a propylene group alone is not included), n is an integer of 1 to 50, l
+ M = 3 and l = 1 or 2, m = 1 or 2,
M is a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, an alkanolamine residue or NH ₄ ).