JPH11315182A - Aqueous emulsion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare an aqueous emulsion not containing an organic solvent, having excellent freezing-melting stability and effectively used as a water- and oil-repelling agent, or the like. SOLUTION: This aqueous emulsion is obtained by dispersing the copolymer of a polyfluoroalkyl group-containing (meth)acrylate ester with at least one of a lower alkyl methacrylate, benzyl (meth)acrylate and vinylidene chloride in water in the presence of a nonionic emulsifier containing an α-[1-(allyloxy) methyl-2-(p-nonylphenoxy)ethyl]-ω-hydroxy(polyoxyethylene).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an aqueous emulsion. More specifically, the present invention relates to an aqueous emulsion used as an active ingredient of a water / oil repellent.

[0002]

2. Description of the Related Art Water / oil repellents containing water-soluble organic solvents such as acetone and ethyl acetate, which are found in the prior art, have excellent freeze-thaw stability, but use an organic solvent to reduce the working environment. There are problems such as contamination, or increase of BOD and COD due to contamination of the wastewater with organic solvents.

[0003] Here, the freeze-thaw stability is a test item for checking whether or not the water- and oil-repellent emulsion returns to the original emulsion when the emulsion is once frozen and then returned to room temperature. If the property is poor, for example, precipitation occurs during transportation in cold regions, or a phenomenon that the viscosity increases,
It is a phenomenon that leads to solidification in some cases. If the emulsion is altered based on such a phenomenon, the commercial value of the water / oil repellent is completely lost.

The following have been proposed as water- and oil-repellents containing the above-mentioned water-soluble organic solvents.

JP-A-7-173772: Water-dispersed fluorine-based water / oil repellent obtained by adding 1 to 20 parts by weight of glycol to 100 parts by weight of a polyfluoroalkyl group-containing polymer. here,
When emulsion polymerization of conventional water-dispersed water- and oil-repellent polymer,
For the purpose of improving the compatibility of the polyfluoroalkyl group-containing monomer in an aqueous medium and the compatibility with other comonomers, a low-boiling organic solvent such as acetone or ethyl acetate is used in the monomer mixture 100.
The residual organic solvent reduced the color fastness because it was used in a proportion of 50 parts by weight or more per part by weight, but such a defect was improved by using a smaller amount of glycol. However, there is no difference in that glycol, which is an organic solvent, is still contained in the water- and oil-repellent aqueous emulsion.

JP-A-5-263070: Emulsion polymerization of a fluoroalkyl group-containing monomer is carried out in an aqueous solution containing a specific glycol ether or glycol ester. Although the use ratio of these glycols per 100 parts by weight of the monomer mixture is about 60 to 100 parts by weight of the usual organic solvent, it is stated that it can be reduced to about 10 to 30 parts by weight,
Also in this case, there is no change in that glycols as an organic solvent are contained in the water- and oil-repellent aqueous emulsion.

JP-A-6-17034: A water- and oil-repellent aqueous latex in which a polyfluoroalkyl group-containing polymer is emulsified and dispersed in an aqueous medium containing a glycol ether-based solvent. The proportion of glycol ether solvent used is about 50% of the total amount with water.
-5% by weight, and a considerably large amount of organic solvent is used.

JP-A-5-279541: Various organic solvents such as acetone coexist during emulsion polymerization for producing a fluorine-containing copolymer. It is said that it is possible to leave a significant portion of the solvent in the formed aqueous dispersion, but preferably the solvent is removed under vacuum at 40-90 ° C for safety and industrial hygiene reasons. A method of increasing the cost by removing it is complicated.

No. 5-17538: Perfluoroalkyl acrylate, carboxyl group-containing α, β-ethylenically unsaturated monomer and hydroxyl group-containing α, β-ethylenically unsaturated monomer are emulsified and dispersed in water. An aqueous emulsion is produced by polymerizing particles having a particle size of 0.3 μm or less. In this method, although an organic solvent is not used, a complicated means of irradiating a pre-emulsion having an average particle diameter of about 1 μm with ultrasonic waves for 60 minutes while bubbling with nitrogen gas to reduce the particle diameter to 0.3 μm or less is used. Not only that, but also a carboxyl group is partially present in the produced copolymer, and even if a small amount of a cation component is mixed during water / oil repellency processing such as immersion, precipitation may occur.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide an aqueous emulsion which contains no organic solvent, has excellent freeze-thaw stability, and is effectively used as a water and oil repellent. .

[0011]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
A copolymer of at least one of lower alkyl methacrylate, benzyl (meth) acrylate and vinylidene chloride and a polyfluoroalkyl group-containing (meth) acrylic acid ester is treated with α- [1- (allyloxy) methyl-2- (p- Nonylphenoxy) ethyl] -ω-hydroxy (polyoxyethylene) is achieved by an aqueous emulsion which is dispersed in water with a nonionic emulsifier.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Having an alkyl group having 1 to 4 carbon atoms
Lower alkyl methacrylate, benzyl acrylate,
Copolymerization with benzyl methacrylate or vinylidene chloride
(Meth) acrylic acid containing polyfluoroalkyl group
As a stele, the general formula CH_Two= CRCOOR₁Rf R: hydrogen atom or methyl group R₁: Divalent organic group Rf: one represented by a perfluoroalkyl group having 4 to 20 carbon atoms, for example, the following (meth)
An acrylate compound is shown. CH_Two= CHCOOC_TwoH_FourC_nF_{2n + 1}  CH_Two= C (CH_Three) COOC_TwoH_FourC_nF_{2n + 1}  CH_Two= CHCOOC_FourH₈C_nF_{2n + 1}  CH_Two= C (CH_Three) COOC_FourH₈C_nF_{2n + 1}  CH_Two= CHCOOC_TwoH_FourN (CH_Three) SO_TwoC_nF_{2n + 1}  CH_Two= C (CH_Three) COOC_TwoH_FourN (CH_Three) SO_TwoC_nF_{2n + 1}  CH_Two= CHCOOC_TwoH_FourN (C_TwoH_Five) SO_TwoC_nF_{2n + 1}  CH_Two= C (CH_Three) COOC_TwoH_FourN (C_TwoH_Five) SO_TwoC_nF_{2n + 1}  CH_Two= CHCOOC_TwoH_FourN (C_ThreeH₇) SO_TwoC_nF_{2n + 1}  CH_Two= C (CH_Three) COOC_TwoH_FourN (C_ThreeH₇) SO_TwoC_nF_{2n + 1}  CH_Two= CHCOOC_TwoH_FourC_nF_2nCF (CF_Three)_Two  CH_Two= C (CH_Three) COOC_TwoH_FourC_nF_2nCF (CF_Three)_Two

These exemplified (meth) acrylic acid esters
Of the tell compounds, preferably R₁= C _TwoH_FourIs used
And the perfluoroalkyl group is linear.
Therefore, a mixture of n having various values has a performance and
It is commonly used in terms of cost and cost.

The comonomer to be copolymerized with the perfluoroalkyl group-containing (meth) acrylic acid ester has 1 to 4 carbon atoms from the viewpoint of both water and oil repellency and freeze-thaw stability. The lower alkyl methacrylate having a lower alkyl group, benzyl (meth) acrylate or vinylidene chloride is selected. Perfluoroalkyl group-containing (meth) acrylate and lower alkyl methacrylate, benzyl (meth) acrylate or vinylidene chloride, to satisfy the above properties, the former is about 30 ~
90% by weight, preferably about 45-85% by weight, while the latter is about 70%
To 10% by weight, preferably about 55 to 15% by weight.

The fluoroalkyl group-containing copolymer containing these as essential components includes hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl methacrylate, glycerin monomethacrylate, and alkylene glycol. Hydroxyl-containing monomers such as mono (meth) acrylate can be further copolymerized in such a proportion that it occupies about 10% by weight or less, preferably about 0.5 to 7% by weight in the copolymer. These monomers can improve the adhesiveness of the water / oil repellent, or can improve the durability of the water / oil repellent by using a crosslinking agent that reacts with a hydroxyl group.

The copolymer further contains about 10% by weight of the copolymer.
% Or less, preferably at a ratio occupying about 0.5 to 7% by weight, a crosslinkable group-containing monomer such as N-methylol (meth) acrylamide, N-methoxymethylacrylamide, N-butoxymethylacrylamide, acrylamide, glycidyl (Meth) acrylate and the like can be copolymerized. These crosslinkable group-containing monomers can crosslink with the hydroxyl groups on the fiber surface or self-crosslink to increase the durability of the water / oil repellent.

In the copolymerization reaction, at least one of lower alkyl methacrylate, benzyl (meth) acrylate and vinylidene chloride and a polyfluoroalkyl group-containing (meth) acrylate are converted to α- [1- (allyloxy) methyl-2
This is carried out by emulsion polymerization in the presence of a nonionic emulsifier containing-(p-nonylphenoxy) ethyl] -ω-hydroxy (polyoxyethylene). Α used here
-[1- (allyloxy) methyl-2- (nonylphenoxy) ethyl] -ω-hydroxy (polyoxyethylene) has the general formula An unsaturated group-containing nonionic emulsifier represented by the formula:
Ethylene oxide having an added mole number of n = 10, 20, 30, or 40 is commercially available as Asahi Denki Adecaria Soap NE series. The value of n is not limited to this range, and generally a value in the range of 10 to 80 can be used.

The unsaturated group-containing nonionic emulsifier comprises:
About 0.5 to 5%, preferably about 1 to 5% by weight of the monomer mixture
Used at a rate of 4%. If the use ratio is less than this, the desired freeze-thaw stability cannot be obtained, while if used at a higher ratio, the water / oil repellency is reduced.

It is desirable that the unsaturated group-containing nonionic emulsifier is used in combination with another commonly used nonionic emulsifier. Other nonionic emulsifiers include polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, and polyoxyethylene such as polyoxyethylene nonyl phenyl ether. About 1 to 8% of the ether derivative based on the weight of the monomer mixture,
It is preferably used in a ratio of about 2 to 6%, and about 1 to 3 times, preferably about 1.5 to 2.5 times the weight of the specific nonionic emulsifier.

As the radical initiator, organic peroxides,
Any of azo compounds, persulfates and the like can be used, but potassium persulfate, ammonium persulfate, 2,2'-azobis (2-amidinopropane) dihydrochloride and the like are preferably used.

The emulsion polymerization reaction is carried out at about 40 to 80 ° C. in an aqueous medium at about 40 ° C.
Performed for about 1 to 10 hours, where the solid content concentration is about 30 to 50 weight
%, Preferably about 30-45% by weight of an aqueous emulsion. In order to improve the stability to freezing, the selection of a non-fluorine-containing monomer is important, but the solid content of the resulting aqueous emulsion is important, and the freezing stability is improved as the solid content is increased. . Solid content concentration is about
If it is less than 30% by weight, the desired freeze-thaw stability cannot be obtained even when a suitable monomer is selected as the fluorine-free monomer.

In order to obtain an aqueous emulsion having such a solid content, it is necessary to increase the polymer concentration. However, if the polymer concentration is rapidly increased, heat generation during the polymerization reaction may be increased, which may be dangerous. In that case, it is safer not to charge the monomer mixture all at once, but to partly or entirely add it.

[0023]

[Action] and

In general, as the temperature of the aqueous emulsion is lowered, the water starts to freeze and ice crystals begin to grow.
When the ice crystals begin to grow, the emulsion particles approach each other and fixation starts. At this time, if there is a protective layer on the surface of the particles, even if the particles are subjected to pressure from ice crystals, no sticking will occur due to the strong protective layer. However, when an effective protective layer does not exist, particles stick, and when the aqueous emulsion is returned to room temperature, the sticking of the particles is not eliminated, resulting in an increase in viscosity, formation of precipitates, solidification of the whole, etc. Will be reached. The emulsifier used during the polymerization reaction can also form a protective layer, but cannot form a strong protective layer that can withstand the pressure of ice crystals.

However, in the present invention, the unsaturated group
By using a nonionic emulsifier having an (allyl group), the emulsifier component can be effectively bonded to the surface of the polyfluoroalkyl group-containing copolymer, whereby a strong protective layer against ice crystals can be formed. .

As described above, in the present invention, an aqueous emulsion having a solid content of about 30% by weight or more can be obtained by using the nonionic emulsifier having an unsaturated group, and this aqueous emulsion has excellent freeze-thaw stability. No special precautions are required during storage in winter or when transporting to cold regions,
Further, it can be effectively used as a water / oil repellent after diluting it with water to a solid concentration of about 0.1 to 1% by weight.

[0026]

Next, the present invention will be described by way of examples.

[0027] Example _{1 CH 2 = CHCOOC 2 H 4} C n F 2n + 1 [FAAC] 300g ( average 9.0 with a mixture of n = having 6 to 14) methacrylate [MMA] 175 g 2-hydroxyethyl acrylate [HEA] 20 g Polyoxyethylene nonyl phenyl ether [Emulsifier A] 12.5 g (Kao product Emulgen 930, HLB = 15.1) Polyoxyethylene nonyl phenyl ether [Emulsifier B] 12.5 g (Kao product Emulgen 950, HLB = 18.2) α- [1- ( Allyloxy) methyl-2- (p-nonylphenoxy) ethyl] 19.2g -ω-hydroxypoly (oxyethylene) [Emulsifier C] (Adeka Electric Soap NEADEA NE-40; n = 40, 65% aqueous solution) Deionized water 1040ml

The above components were charged into a separable flask made of glass having a capacity of 2 L with a stirrer, emulsified with a high-pressure homogenizer (manufactured by Nippon Seiki) at a pressure of 600 kgf / cm ² , and then blown with nitrogen gas. Stir for 30 minutes.

Thereafter, 600 g of the deoxygenated monomer emulsion was taken for dispensing into a stoppered Erlenmeyer flask, and for the remaining monomer emulsion, the internal temperature of the reaction vessel was reduced.
At the time when the temperature was raised to 40 ° C, N- dissolved in 20 ml of deionized water was used.
Charge 5 g of methylol acrylamide (N-MAM), then add 1 g
12 g of 2,2'-azobis (2-amidinopropane) dihydrochloride (V-50, a product of Wako Pure Chemical Industries) dissolved in 00 ml of deionized water was charged.

The internal temperature was gradually raised, and when the temperature reached 65 ° C., 600 g of the monomer emulsion obtained in the Erlenmeyer flask was dropped while being careful not to allow the internal temperature to exceed 70 ° C.
Allowed to react for hours. After the completion of the reaction, the mixture was cooled to obtain 1682 g of an aqueous emulsion having a solid concentration of 31.0% by weight (recovery rate: 94.9%).

Example 2 In Example 1, the same amount of ethyl methacrylate (EMA) was used instead of 175 g of MMA, and α- [1- (allyloxy) methyl-2- (p-nonylphenoxy) was used instead of emulsifier C. Ethyl] -ω-
15.6 g of hydroxypoly (oxyethylene) [Emulsifier D] (Adeka Soap NE-20; n = 20,80% aqueous solution) was used to obtain an aqueous emulsion having a solid content of 31.0% by weight.

Example 3 In Example 1, 140 g of MMA and 35 g of EMA were used instead of 175 g of MMA.
Was used, and the same amount of N-methoxymethylolacrylamide (M-MAM) was used in place of 5 g of N-MAM to obtain an aqueous emulsion having a solid concentration of 31.0% by weight.

Example 4 In Example 1, the same amount of vinylidene chloride was used instead of MMA.
(VdCl ₂ ) was used to obtain an aqueous emulsion having a solid content of 31.0% by weight.

Example 5 In Example 1, the same amount of benzyl methacrylate (BzMAC) was used in place of MMA to obtain an aqueous emulsion having a solid concentration of 31.0% by weight.

Example 6 In Example 1, the same amount of benzyl acrylate (BzAC) was used instead of 175 g of MMA, and the solid content was 31.0% by weight.
An aqueous emulsion of was obtained.

Example 7 In Example 1, 140 g of VdCl ₂ and BzM were used instead of 175 g of MMA.
An aqueous emulsion having a solid content of 30.5% by weight was obtained using 35 g of AC.

Example 8 In Example 1, 140 g of VdCl ₂ and BzA were used instead of 175 g of MMA.
An aqueous emulsion having a solid content of 30.5% by weight was obtained using 35 g of C.

Example 9 In Example 3, the amount of deionized water was changed to 542 ml to obtain an aqueous emulsion having a solid content of 45.1% by weight.

Example 10 In Example 3, the amount of deionized water was changed to 542 ml, and the same amount of N-MAM was used in place of 5 g of M-MAM to obtain an aqueous emulsion having a solids concentration of 45.1% by weight. .

Comparative Example 1 In Example 1, the amount of deionized water was 13
After changing to 58 ml and performing emulsification and stirring while blowing nitrogen gas, the internal temperature of the reaction vessel was raised to 40 ° C, and N-
Methylol acrylamide aqueous solution and 2,2'-azobis
(2-Amidinopropane) · dihydrochloride aqueous solution was charged in the same manner. Thereafter, the internal temperature was raised to 70 ° C., and the reaction was carried out at that temperature for 4 hours.
Of aqueous emulsion (recovery rate 94.3%).

Comparative Example 2 In Comparative Example 1, the same amount of EMA was used instead of 175 g of MMA.

Comparative Example 3 In Comparative Example 1, 140 g of MMA and 35 g of EMA were used instead of 175 g of MMA.
Was used, and the same amount of M-MAM was used instead of 5 g of N-MAM.

Comparative Example 4 In Comparative Example 1, the same amount of VdCl ₂ was used instead of 175 g of MMA.

Comparative Example 5 In Comparative Example 1, the same amount of BzMAC was used instead of 175 g of MMA.

Comparative Example 6 In Comparative Example 1, the same amount of BzAC was used instead of 175 g of MMA.

Comparative Example 7 In Comparative Example 1, 140 g of VdCl ₂ and BzM were used instead of 175 g of MMA.
AC 35 g was used.

Comparative Example 8 In Comparative Example 1, 140 g of VdCl ₂ and BzA were used instead of 175 g of MMA.
35 g of C was used.

Comparative Example 9 In Example 1, the same amount of 2-ethylhexyl methacrylate was used instead of 175 g of methyl methacrylate.

Comparative Example 10 In Example 1, the same amount of lauryl methacrylate was used instead of 175 g of methyl methacrylate.

Comparative Example 11 In Example 1, the same amount of stearyl methacrylate was used instead of 175 g of methyl methacrylate.

Examples 11-20, Comparative Examples 12-22 The aqueous solutions obtained in Examples 1-10 and Comparative Examples 1-11 above were
Increase the solid content of marjon to 0.5% or 0.25% by weight
Use diluents diluted with water and place in these diluent treatment baths.
Nylon / Taffeta or Polyester / Amunsen
Dipped cloth and squeezed with mangle to the specified pickup
After drying, drying and curing were performed.Processing conditions Nylon / taffeta Polyester / Amunsen  Processing solution concentration (wt%) 0.5 0.25 Pickup (%) 40 60 Drying conditions Temperature (° C) 80 80 hours (min) 10 10 Cure conditions Temperature (° C) 170 150 hours (min) 1.5 3

Water repellency and oil repellency were measured for each of the cloths thus treated. Water repellency: Number 0 to 100 by spray test of JIS L-1092 (1992), the higher the number, the better the performance. Oil repellency: Number 0 to 8 by AATCC TM-118 (1992) , The higher the number, the better the performance

Further, the freeze-thaw stability of the aqueous emulsions obtained in Examples 1 to 10 and Comparative Examples 1 to 11 was measured. Freeze-thaw stability: The aqueous emulsion is placed in a -25 ° C freezer for 16 hours and then kept at room temperature for 8 hours. afterwards,
Visual observation of the state of the aqueous emulsion, separation, thickening,
The test is continued until changes such as precipitation and solidification are observed, and the maximum number of freeze-thaw cycles in which these changes are not observed is counted.

The results obtained are shown in the following table. Table Water EmmaWater / oil repellency (water / oil repellency) Freeze-thawAn example Rejon Nylon polyester Number  Example 11 Example 1 100/3 100/3 10 times or more 〃 12 〃 2 〃 〃 〃 〃 13 〃 3 〃 〃 〃 〃 14 〃 4 100/4 100/4 〃 〃 15 〃 5 〃 〃 〃 〃 16 〃 6 〃 〃 〃 〃 17 〃 7 〃 〃 〃 〃 18 〃 8 〃 〃 〃 〃 19 〃 9 100/3 100/3 〃 〃 20 〃 10 〃 〃 〃 Comparative Example 12 Comparative Example 1 〃 ０ 0 〃 13 〃 2 〃 〃 〃 〃 14 〃 3 〃 〃 〃 〃 15 〃 4 100/4 100/4 〃 〃 16 〃 5 〃 〃 〃 〃 17 〃 6 〃 〃 〃 〃 〃 18 〃 7 〃 〃 〃 〃 19 〃 8 〃 〃 〃 〃 20 〃 9 100/3 100/3 〃 〃 21 〃 10 〃 〃 〃 〃 22 〃 11 〃 〃 〃

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08F 214/08 C08F 214/08 220/18 220/18 220/24 220/24 D06M 15/277 D06M 15/277

Claims (7)

[Claims] 1. A lower alkyl methacrylate, benzyl
A copolymer of at least one of (meth) acrylate and vinylidene chloride and a polyfluoroalkyl group-containing (meth) acrylic ester is treated with α- [1- (allyloxy) methyl-2-
An aqueous emulsion prepared by dispersing in water with a nonionic emulsifier containing (p-nonylphenoxy) ethyl] -ω-hydroxy (polyoxyethylene). 2. A nonionic emulsifier, α- [1- (allyloxy) methyl-2- (p-nonylphenoxy) ethyl] -ω-
2. The aqueous emulsion according to claim 1, wherein hydroxy (polyoxyethylene) and another nonionic emulsifier are used in combination. 3. The aqueous emulsion according to claim 1, wherein a copolymer obtained by further copolymerizing a hydroxyl group-containing monomer is used. 4. The aqueous emulsion according to claim 1, wherein a copolymer obtained by further copolymerizing a monomer having a crosslinkable group is used. 5. A water and oil repellent comprising the aqueous emulsion according to claim 1, 2, 3 or 4 as an active ingredient. 6. A lower alkyl methacrylate, benzyl
A copolymer of at least one of (meth) acrylate and vinylidene chloride and a polyfluoroalkyl group-containing (meth) acrylic ester is treated with α- [1- (allyloxy) methyl-2-
A process for producing an aqueous emulsion, which comprises carrying out emulsion polymerization in the presence of a nonionic emulsifier containing (p-nonylphenoxy) ethyl] -ω-hydroxy (polyoxyethylene). 7. A nonionic emulsifier, α- [1- (allyloxy) methyl-2- (p-nonylphenoxy) ethyl] -ω-
7. The method for producing an aqueous emulsion according to claim 6, wherein hydroxy (polyoxyethylene) and another nonionic emulsifier are used in combination.