JPH0662685B2 - Emulsifier for emulsion polymerization - Google Patents

Description

TECHNICAL FIELD The present invention relates to an emulsifier for emulsion polymerization. More specifically, in the emulsion polymerization of an ethylenically unsaturated monomer or a conjugated diene unsaturated monomer or a mixture of these monomers,
In particular, the present invention relates to an emulsifier for emulsion polymerization capable of providing an emulsion suitable for forming a film (film) having significantly improved water resistance.

[Conventional technology]

Conventionally, it is known to use an anion activator as an emulsifier for emulsion polymerization. In this case, as the anion activator, alkyl sulfate, polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl phenyl ether sulfate, alkyl benzene sulfonate, alkyl diphenyl ether disulfonate and the like are used. However, when emulsion polymerization is carried out using these anionic activators, the emulsion obtained is inferior in water resistance, and when used in paints, adhesives, pressure-sensitive adhesives, paper processing agents, etc. It has the drawback of peeling and peeling.

On the other hand, in order to solve such a drawback, in recent years, a group having a surface-active property and a group having a polymerizable property are used in combination in the molecule, not only acting as an emulsifier of a monomer, but also an anionic activator which is polymerized or copolymerized by itself. Various proposals have been made. For example, a method using a copolymerizable emulsifier having an allyl group as a polymerization group (Japanese Patent Publication No. 49-46291) and a method using a copolymerizable emulsifier of maleic acid, fumaric acid or itaconic acid derivative (Japanese Patent Publication No. 51-30284). Issue gazette) etc.

However, in these methods, due to the low copolymerizability of the malein group, fumar group, itaconyl group, and allyl group contained in the structure, various ethylenically unsaturated monomers or conjugated diene unsaturated monomer Since the problem of polymerizability with the body arises and the above-mentioned drawbacks of water resistance due to the anionic activator cannot be sufficiently solved, development of an emulsifier for emulsion polymerization having good water resistance is required.

[Means for solving problems]

The present inventors have conducted extensive studies on an emulsifying agent for emulsion polymerization in order to solve the above-mentioned drawbacks found in conventional anionic surfactants, and as a result, have a radically polymerizable unsaturated carboxylic acid group and a sulfate ester group in the structure, which will be described later. A film in which the compound represented by the formula (I) has remarkably improved water resistance (film)
The present invention has been completed by finding that it is an emulsifier for emulsion polymerization, which can provide emulsion suitable for the formation of

That is, the emulsion polymerization emulsifier of the present invention has the general formula [Wherein R ¹ and R ² are hydrogen atoms or alkyl groups having 1 to 25 carbon atoms and may be the same or different, and R ³ and R ⁴ are alkyl groups having 1 to 25 carbon atoms and benzyl group. , Or a styrene group, which may be the same or different, and m is 0
-2, and Z ¹ and Z ² may be the same or different and have the formula -A ¹ -OA ² -OA ³ -... A ⁿ -O- (wherein A ¹ , A ² , A ³ , ... A ⁿ represent an ethylene group or a propylene group, and may be the same or different, and n represents a polyalkyleneoxy group represented by 1.), and M represents an alkali group. A metal atom, an alkaline earth metal atom, ammonium, or an amine cation is shown, and X is a hydrogen atom or a methyl group. ] It is a compound shown by these.

The emulsifier for emulsion polymerization represented by the above formula (I) of the present invention can be produced by a known method. For example, a substituted or unsubstituted phenol and formalin can be prepared by a conventional method (industrial chemistry magazine,
Volume 66, 391, 1963. Oil Chemistry, Volume 12, p. 625, 1963
Years) to condense under acidic or alkaline conditions, then
Addition of desired amount of alkylene oxide in the presence of catalyst such as alkali and acid by conventional method (Industrial Chemistry, Vol. 66, 391, 1963. Oil chemistry, Vol. 12, 625, 1963) Polymerization to synthesize an alkylene oxide adduct of a substituted or unsubstituted phenol formaldehyde condensate, and then α-
In the presence of an unsaturated carboxylic acid and a catalyst (for example, an inorganic acid such as sulfuric acid) and a polymerization inhibitor (for example, a phenol-based inhibitor such as hydroquinone), a conventional method (Kyoritsu Shuppan, Polymer Experiments Course 9, Synthesis method ”, p. 147, 1961) to synthesize a polymerizable ester of an alkylene oxide adduct of a substituted or unsubstituted phenol formaldehyde condensate, and finally a conventional method with a sulfating agent (Sankyo Publishing, Hiroshi Horiguchi, "New Surfactants," 322-326, 1975. Sulfated by Maki Shoten Publishing, Ryohei Oda, Kazuhiro Teramura, "Surfactants, Synthetic Edition I, 109-110, 1965). After that, it can be manufactured by the method of neutralizing.

The substituted or unsubstituted phenols include phenol, cresol, propylphenol, isopropylphenol, n-butylphenol, isobutylphenol, se.
c-butylphenol, t-butylphenol, amylphenol, octylphenol, nonylphenol,
Dodecylphenol, styrenated phenol, benzylated phenol, styrenated cresol, benzylated cresol, xylenol, di-t-butylphenol, dioctylphenol, dinonylphenol, styrenated nonylphenol, styrenated octylphenol and the like can be mentioned.

Examples of the alkylene oxide adduct of the substituted or unsubstituted phenol formaldehyde condensate include ethylene oxide and / or propylene oxide adduct of the substituted or unsubstituted phenol formaldehyde condensate.

The α-unsaturated carboxylic acid used in the reaction of the substituted or unsubstituted phenol formaldehyde condensate with the alkylene oxide adduct includes acrylic acid or methacrylic acid.

Examples of the sulfating agent include sulfuric acid, fuming sulfuric acid, chlorosulfonic acid, sulfuric anhydride, sulfamic acid and the like.

Lithium, sodium, potassium as alkaline metal atoms and calcium as alkaline earth metal atoms,
It contains magnesium, barium, etc., and as amine cations, ammonia and lower alkylamines (methylamine, ethylamine, isopropylamine, dimethylamine, triethylamine, etc.), alkanolamines (monoethanolamine, triethanolamine, etc.), alkanolalkylamines ( Methyl ethanolamine,
Examples include amine cations such as methyldiethanolamine, dimethylethanolamine, diethylethanolamine, dimethyldiethanolamine, diethyldiethanolamine, and heterocyclic amines (morpholine, etc.).

Specific examples of typical compounds of the emulsifier for emulsion polymerization represented by the above formula (I) include the following.

1) EO of p-nonylphenol formaldehyde condensate
(10 mol) Additive polymerizable ester ammonium sulfate salt.

2) Distyrenated phenol formaldehyde condensate
Polymerizable ester ammonium sulfate salt of EO (10 mol) adduct.

3) p-octylphenol formaldehyde condensate
Polymerizable ester sulfate sodium salt of EO (20 mol) PO (2 mol) adduct.

4) Sodium salt of polymerizable ester sulfate of PO (8 mol) adduct of O · P-dibutylphenol formaldehyde condensate.

5) Polymerizable ester ammonium sulfate salt of EO (10 mol) PO (5 mol) EO (15 mol) adduct of styrenated p-octylphenol-formaldehyde condensate.

6) Polymerizable ester sodium sulfate salt of [EO (10 mol) PO (5 mol)] random adduct of p-nonylphenol formaldehyde condensate.

[In the above description, EO (10 moles) means that ethylene oxide is polycondensed on average 10 moles, and PO (2 moles)
Indicates that propylene oxide is polycondensed on average of 2 moles. Others follow this. The emulsifier for emulsion polymerization of the present invention, of course, exhibits sufficient functions by itself, but can be used in combination with a nonionic activator and an anionic activator, if necessary, and also acts as a stabilizer (protective colloid) for emulsion. It can also be used in combination with a water-soluble polymer substance. As the nonionic activator in this case,
Polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, pluronic type activator and the like can be used, and particularly, the average addition mole number of ethylene oxide is 8-10.
0, preferably 8-50 polyoxyethylene based nonionic activators are suitable. When used in combination with an anion activator, for example, long-chain alkyl sulfate, long-chain alkylbenzene sulfonate, polyoxyethylene alkylphenyl ether sulfate, alkyldiphenyl ether disulfonate, etc. can be used. As the water-soluble polymer substance, polyvinyl alcohol, hydroxyethyl cellulose, etc. can be used. When it is used in combination with a nonionic activator and / or an anionic activator and / or a water-soluble polymeric substance, it is 0.05
-10 parts by weight is suitable.

The emulsifier of the present invention can be used for emulsion polymerization of various monomers. Examples of such monomers include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylate. ) 2-ethylhexyl acrylate,
Esters of acrylic acid or methacrylic acid such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate: vinyl bromide, vinyl chloride,
Vinyl halides such as vinylidene chloride: Acetic acid, propionic acid, vinyl esters of fatty acids such as tertiary synthetic saturated carboxylic acids: Aromatic vinyls such as styrene and α-methylstyrene: Monoolefins such as ethylene and butadiene, or conjugated diolephins Classes: Vinyl cyanides such as acrylonitrile: α-β-unsaturated amides such as acrylamide: α-β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid and fumaric acid.

As the polymerization initiator, initiators usually used for emulsion polymerization can be used without particular limitation, and for example, hydrogen peroxide, potassium persulfate, sodium persulfate, ammonium persulfate, etc. are used, and sodium bisulfite is used as necessary. A reducing agent such as sodium thiosulfate can also be used in combination.

In emulsion-polymerizing a monomer using the emulsifier of the present invention, the emulsifier of the present invention can be used in the same manner as a conventionally known emulsifying agent for emulsion polymerization, and for example, 100% by weight of the monomer. The monomer is typically dispersed and emulsified in water to a concentration of 20-70% by weight in the presence of an emulsifier corresponding to 0.1-10 parts by weight, and 0.1 -2
Emulsion polymerization can be carried out by adding a polymerization initiator corresponding to parts by weight. In this case, the polymerization temperature is usually 40-
90 ° C., preferably 50-80 ° C. The polymerization time is usually 2-10 hours, preferably 3-6 hours. It is also conventional that a pH adjusting agent, a polymerization adjusting agent, and other known additives can be used if necessary.

The polymer emulsion obtained by emulsion-polymerizing the monomer using the emulsifier of the present invention is compared with the polymer emulsion obtained by emulsion-polymerizing the monomer using a conventional anion activator. The film formed from emulsion has the effects of significantly improving whitening and blistering when immersed in water, and having low water absorption. Further, this emulsion has good chemical stability, mechanical stability, storage stability and pigment miscibility.

〔Example〕

Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The parts in the examples and comparative examples represent parts by weight, and%
Indicates% by weight.

Example 1 50 parts of butyl acrylate, 30 parts of methyl methacrylate, 20 parts of styrene and 2 parts of acrylic acid were mixed to prepare a monomer mixture.

The emulsifier p-nonylphenol formaldehyde condensate of the present invention 1.5 parts of the polymerizable ester ammonium sulfate salt of the EO (10 mol) adduct of the condensate of p-nonylphenol formaldehyde was dissolved in 44 parts of deionized water to prepare an emulsifier aqueous solution. This aqueous solution and the above monomer mixture were mixed and stirred to obtain 147.5 parts of an aqueous monomer dispersion.

Next, 50 parts of ion-exchanged water was charged into a glass reactor equipped with a reflux condenser, a thermometer, a nitrogen gas inlet, a dropping funnel and a stirrer, and the temperature was raised to 80 ° C. In a nitrogen stream, 10 parts of a 5% ammonium persulfate aqueous solution was added with stirring. Next, 147.5 parts of the above-mentioned monomer aqueous dispersion was continuously added dropwise over 120 minutes, while maintaining the temperature at 80 ° C. for polymerization. After the dropping was completed, the temperature was kept at the same temperature for 60 minutes to complete the polymerization to obtain a polymer emulsion.

Example 2 Emulsion polymerization was carried out under the same conditions as in Example 1 except that 5 parts of a polymerizable ester ammonium sulfate salt of an EO (10 mol) adduct of the emulsifier p-nonylphenolformaldehyde condensate of the present invention was used.

Example 3 Emulsion polymerization was carried out under the same conditions as in Example 1 except that 1.5 parts of the polymerizable ester ammonium sulfate of the EO (10 mol) adduct of the emulsifier distyrenated phenol formaldehyde condensate of the present invention was used.

Comparative Example 1 Emulsion polymerization was carried out under the same conditions as in Example 1 except that 1.5 parts of a typical known emulsifying agent sodium alkyldiphenyl ether disulfonate was used.

Comparative Example 2 Emulsion polymerization was carried out under the same conditions as in Example 1 except that 1.5 parts of a representative known emulsifier polyoxyethylene (6) nonylphenyl ether sulfate ammonium salt was used.

Comparative Example 3 Emulsion polymerization was performed under the same conditions as in Example 1 except that 1.5 parts of a representative known emulsifier sulfosuccinic acid alkylalkenyl sodium salt was used.

Next, the physical properties of the polymer emulsions obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were measured. The results are shown in Table 1.

From the results shown in Table 1, when the emulsifier of the present invention was used, the water resistance of the film formed from the obtained polymer emulsion was good.

Further, the emulsifier of the present invention was excellent in water resistance even if the amount used was increased.

The measuring methods for each item in Table 1 are as follows.

Polymerization stability: Pass with 100 mesh cheese cloth, wash the excess residue with water, and dry with hot air at 105 ± 2 ° C. for 2 hours to obtain a coagulum. This dry weight is expressed in% by weight with respect to the monomers used.

Polymerization conversion rate: Expressed as the solid content of emulsion to the theoretical solid content weight%.

Viscosity: BL type viscometer (25 ° C, 60RPM) Storage stability: Polymer emulsion is evaluated by the following symbols when left for 6 months at room temperature.

∘: Almost no gelation, separation or thickening was observed.

X: There is gelation, separation, or considerable thickening is observed.

Whitening: A film (film) made by applying emulsion to a glass plate using a 10 mil applicator and drying in hot air at 50 ° C for 15 minutes is immersed in warm water at 40 ° C, and the time required for whitening is indicated by the following symbols. Evaluated.

A: 1 day or more O: 1 hour or more and less than 1 day X ... Less than 1 hour XX ... Instantaneous swelling or sagging: The state of the film (film) used in the whitening test is visually determined.

Water Absorption: The water absorption (%) of a film having a thickness of about 0.2 mm formed from emulsion is soaked in 30 ° C warm water for 48 hours.

Example 4 50 parts of 2-ethylhexyl acrylate, 50 parts of methyl methacrylate and 2 parts of acrylic acid were mixed to prepare a monomer mixture.

The emulsifier p-octylphenol-formaldehyde condensate of the present invention was dissolved in EO (20 mol) PO (2 mol) adduct polymerizable ester sulfate sodium salt (1.5 parts) in ion-exchanged water (44 parts) to prepare an aqueous emulsifier solution. This aqueous solution and the above monomer mixture were mixed and stirred to obtain 147.5 parts of an aqueous monomer dispersion.

Next, 50 parts of ion-exchanged water was charged into a glass reactor equipped with a reflux condenser, a thermometer, a nitrogen gas inlet, a dropping funnel and a stirrer, and the temperature was raised to 80 ° C. In a nitrogen stream, 10 parts of a 5% ammonium persulfate aqueous solution was added with stirring. Next, 147.5 parts of the above-mentioned monomer aqueous dispersion was continuously added dropwise over 120 minutes, while maintaining the temperature at 80 ° C. for polymerization. After the dropping was completed, the temperature was kept at the same temperature for 60 minutes to complete the polymerization to obtain a polymer emulsion.

Example 5 Emulsion polymerization under the same conditions as in Example 4 except that 1.5 parts of the polymerizable ester sulfate sodium salt of the PO (8 mol) adduct of the emulsifier O.P-dibutylphenolformaldehyde condensate of the present invention was used. I went.

Example 6 Emulsion polymerization was carried out under the same conditions as in Example 4 except that 1.5 parts of a polymerizable ester ammonium sulfate salt of an EO (10 mol) adduct of the emulsifier p-nonylphenolformaldehyde condensate of the present invention was used.

Comparative Example 4 Example 4 except that 1.5 parts of a representative known emulsifying agent alkyldiphenyl ether disulfonic acid sodium salt was used.
Emulsion polymerization was carried out under the same conditions as in.

Comparative Example 5 Emulsion polymerization was carried out under the same conditions as in Example 4 except that 1.5 parts of a representative known emulsifier polyoxyethylene (6) nonylphenyl ether sulfate ammonium salt was used.

Next, the physical properties of the polymer emulsions obtained in Examples 4 to 6 and Comparative Examples 4 to 5 were measured by the methods described above. The results are shown in Table 2.

From the results shown in Table 2, when the emulsifier of the present invention was used, the water resistance of the film formed from the obtained polymer emulsion was as good as in Table 1.

Example 7 70 parts of vinyl acetate, 30 parts of Beovar 10 (vinyl ester of a tertiary synthetic saturated carboxylic acid (product of Shell Chemical Co.)) and 2 parts of acrylic acid were mixed to prepare a monomer mixture.

The emulsifier of the present invention 1.5 parts of the polymerizable ester ammonium sulfate salt of the EO (10 mol) adduct of the distyrenated phenol formaldehyde condensate was dissolved in 44 parts of ion-exchanged water to prepare an emulsifier aqueous solution. This aqueous solution and the above monomer mixture were mixed and stirred to obtain 147.5 parts of an aqueous monomer dispersion.

Next, 50 parts of ion-exchanged water was charged into a glass reactor equipped with a reflux condenser, a thermometer, a nitrogen gas inlet, a dropping funnel and a stirrer, and the temperature was raised to 80 ° C. In a nitrogen stream, 10 parts of a 5% ammonium persulfate aqueous solution was added with stirring. Next, 147.5 parts of the above-mentioned monomer aqueous dispersion was continuously added dropwise over 120 minutes, while maintaining the temperature at 80 ° C. for polymerization. After the dropping was completed, the temperature was kept at the same temperature for 60 minutes to complete the polymerization to obtain a polymer emulsion.

Example 8 Emulsifier of the invention Styrenated p-octylphenol formaldehyde condensate EO (10 mol) PO (5 mol) EO (15
Mol) adduct polymerizable ester sulfate ammonium salt 1.
Emulsion polymerization was carried out under the same conditions as in Example 7 except that 5 parts were used.

Example 9 Same as Example 7 except that 1.5 parts of polymerizable ester sodium sulfate salt of [EO (10 mol) PO (5 mol)] random adduct of the emulsifier p-nonylphenol formaldehyde condensate of the present invention was used. The emulsion polymerization was carried out under various conditions.

Comparative Example 6 Example 7 except that 1.5 parts of a representative known emulsifier alkyldiphenyl ether disulfonic acid sodium salt was used.
Emulsion polymerization was carried out under the same conditions as in.

Comparative Example 7 Emulsion polymerization was carried out under the same conditions as in Example 7 except that 1.5 parts of a representative known emulsifier sulfosuccinic acid alkylalkenyl sodium salt was used.

Next, the physical properties of the polymer emulsions obtained in Examples 7 to 9 and Comparative Examples 6 to 7 were measured by the methods described above. The results are shown in Table 3.

From the results shown in Table 3, when the emulsifier of the present invention was used, the water resistance of the film formed from the obtained polymer emulsion was better than that of the control product.

[Effects of the Invention] As is clear from Tables 1, 2, and 3, the film (film) of the polymer emulsion obtained by using the emulsifying agent for emulsion polymerization according to the present invention gives an excellent effect on water resistance. It is a thing.

Claims (1)

[Claims] 1. A formula [Wherein R ¹ and R ² are a hydrogen atom or an alkyl group having 1 to 25 carbon atoms and may be the same or different, and R ³ and R ⁴ are alkyl groups having 1 to 25 carbon atoms and a benzyl group. , Or a styrene group, which may be the same or different, and m is 0
Is an integer of -2, Z ¹ and Z ² may be the same or different, and have the formula -A ¹ -OA ² -OA ³ -... A ⁿ -O- (wherein A ¹ , A ² , A ³ , ..., A ⁿ are ethylene groups or propylene groups and may be the same or different, and n is an integer of 1 or more.) Is a polyalkyleneoxy group, and M is an alkali metal. Atom, alkaline earth metal atom,
It represents an ammonium or amine cation, and X represents a hydrogen atom or a methyl group. ] The compound shown by these is included as an essential component, The emulsifier for emulsion polymerization characterized by the above-mentioned.