CHENG QILI (CN)
ZHU RUNJUN (CN)
| CN101668827A | 2010-03-10 | |||
| CN1626580A | 2005-06-15 | |||
| CN102493193A | 2012-06-13 | |||
| CN1206721A | 1999-02-03 | |||
| CN101538795A | 2009-09-23 | |||
| CA2545349A1 | 2005-05-26 | |||
| US6660803B1 | 2003-12-09 |
| Claims 1. A process for emulsion polymerizing at least one fluorine-containing monomer or a monomer composition comprising at least 30 wt% of the at least one fluorine-containing monomer, based on the total weight of the monomer composition, wherein, the emulsion polymerization is conducted at 95-200°C. 2. The process of claim 1, wherein the fluorine-containing monomer is a fluorine-containing (meth)acrylate. 3. The process of claim 2, wherein the fluorine-containing monomer has the following formula: CH2=C(-X)-C(=0)-Y-Z-Rf (1) wherein X is H or CH3; Y is O or NH; Z is an aliphatic group having 1-10 carbon atoms, an aromatic or cycloaliphatic group having 6-18 carbon atoms, a -CH2CH2N(R1)S02- group (in which R1 is an alkyl group having 1 to 4 carbon atoms), a -CH2CH(OZ1)CH2- group (in which Z1 is a hydrogen atom or an acetyl group), a -(CH2)m-S02-(CH2)n- group or a -(CH2)m-S-(CH2)n- group where m is 1-10 and n is 0-10; and Rf is a linear or branched, partially or fully fluorine-substituted alkyl group having 1-20 carbon atoms. 4. The process of claim 3, wherein the Rf group is a perfluoroalkyl group. 5. The process of claim 3, wherein Z is a linear or branched alkylene group having 2-6 carbon atoms, preferably is -CH2CH2-; Rf is a linear or branched perfluoroalkyl group having 6-12 carbon atoms, preferably is a linear perfluoroalkyl group having 8-10 carbon atoms. 6. The process of any one of claims 1-5, wherein the monomer composition further comprises at least 30 wt% of at least one hydrophobic monomer selected from C8-C40, preferably Ci0-C2 , more preferably Ci3-C22 alkyl (meth)acrylates, C8-C 0, preferably Ci0-C2 , more preferably Ci3-C22 alkyl acyloxy vinyl esters. 7. The process of any one of claims 1 -6, wherein the monomer composition comprises: a) 30-70 wt% of at least one fluorine-containing monomer selected from (C6- Ci2 perfluoroalkyl) (C2-C6 alkylene) (meth)acrylates, b) 30-70 wt% of at least one hydrophobic monomer selected from Ci2-C24, preferably Ci3-C22 alkyl (meth)acrylates, c) 0-30 wt% of at least one monomer selected from vinyl chloride, (meth)acrylic acid, hydroxyl esters, poly(alkylene glycol) ether esters, Ci-C5 alkyl terminated poly(alkylene glycol) ether esters, glycidyl esters, and alkyl tertiary amino esters of (meth)acrylic acid; (meth)acrylamide, N-alkylol (meth)acrylamide, N-alkyl tertiary amino (meth)acrylamide; salt of alkyl tertiary amino esters of (meth)acrylic acid and N-alkyl tertiary amino (meth)acrylamide; Ci-C5 alkyl acyloxy vinyl esters; vinyl siloxane, (meth)acyloxy siloxane; self-crosslinkable monomers, such as diacetone acrylamide and acetoacetoxyethyl (meth)acrylate; and polyethylenically unsaturated monomers. 8. The process of any one of claims 1-7, wherein the monomer composition comprises: a) 30-65 wt% of at least one fluorine-containing monomer selected from 2- (perfluorohexyl)ethyl (meth)acrylate and 2-(perfluorooctyl)ethyl (meth)acrylate; b) 30-65 wt% of at least one hydrophobic monomer selected from hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, eicosyl (meth)acrylate and docosyl (meth)acrylate; c) 5-20 wt% of at least one monomer selected from hydroxy ethyl (meth)acrylate, hydroxypropyl (meth)acrylate, (meth)acrylamide, N-methylol (meth)acrylamide and vinyl chloride. 9. The process of any one of the preceding claims, wherein the emulsion polymerization is conducted at 95-180°C, preferably 100-170°C, more preferably 120-140°C. 10. The process of any one of the preceding claims, wherein the process is carried out under a pressure of l-30atm, preferably l-20atm, more preferably 1- lOatm. 11. The process of any one of the preceding claims, wherein the solvent for the emulsion polymerization is an aqueous solvent, preferably substantially consists of water, more preferably is water. 12. Emulsion polymer obtained by the process of any one of the preceding claims. 13. A water and oil repellent agent which is an aqueous dispersion comprising the emulsion polymer of claim 12. 14. A process for preparing a water and oil repellent agent, comprising emulsion polymerizing at least one fluorine-containing monomer or a monomer composition comprising at least 30 wt% of the at least one fluorine-containing monomer, based on the total weight of the monomer composition, according to the process of any one of claims 1-11. |
Field of the invention
The present invention relates to a process for emulsion polymerizing fluorine- containing monomers. Particularly, the present invention relates to a process for preparing emulsion polymers which comprise significant amount of fluorine- containing monomers.
Background
Fluorine-containing emulsion polymers are widely used in industry. For example, polymers prepared from a polymerizable compound having a perfluoroalkyl or perfluoroalkenyl group and an acrylate or methacrylate group have many desirable properties such as superior weather resistance, high temperature resistance, water and oil repellency, low surface tension, chemical inertness, and low flammability. Some of the properties are useful for a water- and oil-repellent agent used for a textile/woven fabric.
It is well known that it is very difficult to prepare emulsion polymers from fluorine-containing monomers, particularly those containing long perfluorinated alkyl chains, such as fluoroalkyl groups having 4 to 20 carbon atoms, especially when they make up more than 30% of the monomer composition, because these monomers are inherently water insoluble and also have poor solubility in most organic hydrocarbon solvents. The insolubility of perfluorinated monomers limits their ability to be transported from monomer droplets to polymerizing particles. As a result, particle size distribution is broad; composition of a copolymer may not be uniform.
Various methods of polymerizing fluorinated monomers have been developed. One method is using an organic solvent miscible with water to dissolve the fluorinated monomer. Such solvents aid the transportation of monomer from the monomer droplets to the polymerizing particles. Another method uses relatively high levels of fluorinated surfactants or a combination of fluorinated surfactant and a compatibilizer containing a perfluorinated segment and a hydrocarbon segment to avoid gels. These methods have the disadvantage of introducing "foreign" components to the polymer latex, for example, organic solvents contribute to volatile organic compound content, and perfluorinated surfactants dilute the polymer content and end up in the polymer film where they can migrate and thereby alter the surface composition and properties of the film. The use of large amounts of fluorinated surfactants adds to the cost of the polymer latex, which is undesirable.
An alternative method to prepare this kind of polymer commercially is miniemulsion polymerization where the monomer pre-emulsion is prepared by high-speed shearing and/or ultrasonic wave treatment. In order to make preemulsion stable and to get better polymerization efficiency (monomer conversion), fine preemulsion is made before polymerization. CN1346394A disclosed a process for preparing fluorinate acrylic emulsion polymer for water and oil repellency agent, in which monomer preemulsion was prepared under ultrasonic wave for 15min before polymerization. Although high energy ultrasonic wave is helpful to make these fluorinated/non-fluorinated hydrophobic monomers in emulsion, it's limited and critical to use this treatment method in large scale production.
Summary of the invention
The present invention provides a process for emulsion polymerizing at least one fluorine-containing monomer or a monomer composition comprising at least 30 wt% of the at least one fluorine-containing monomer, based on the total weight of the monomer composition,
wherein the emulsion polymerization is conducted at 95-200°C.
The present invention further provides the emulsion polymer obtained from the process of the present invention.
The present invention further provides a water and oil repellent agent which is an aqueous dispersion comprising the emulsion polymer of the present invention.
The present invention further provides a process for preparing a water and oil repellent agent, comprising emulsion polymerizing at least one fluorine- containing monomer or a monomer composition comprising at least 30 wt% of the at least one fluorine-containing monomer according to the process of the present invention. Detailed description of the invention
Although water solubility is not always a linear function of temperature, high temperature can increase diffusivity for low polar and non-polar monomers. By elevating temperature, it is possible to increase saturation concentration of hydrophobic monomers in water, which makes it possible for emulsion polymerizing hydrophobic monomers. Therefore, ultra high shear or ultrasound is not necessarily required to form ultra fine droplets for preparing monomer pre-emulsion in the present invention.
Preferably, the fluorine-containing monomer is a fluorine-containing (meth)acrylate.
More preferably, the fluorine-containing monomer has the following formula:
CH 2 =C(-X)-C(=0)-Y-Z-Rf (1)
wherein
X is H or CH 3 ;
Y is O or NH;
Z is an aliphatic group having 1-10 carbon atoms, an aromatic or cycloaliphatic group having 6-18 carbon atoms, a -CH 2 CH 2 N(R 1 )S0 2 - group (in which R 1 is an alkyl group having 1 to 4 carbon atoms), a -CH 2 CH(OZ 1 )CH 2 - group (in which Z 1 is a hydrogen atom or an acetyl group), a -(CH 2 )m-S0 2 -(CH 2 )n- group or a -(CH 2 )m-S-(CH 2 )n- group where m is 1-10 and n is 0-10; and
Rf is a linear or branched, partially or fully fluorine-substituted alkyl group having 1-20 carbon atoms.
More preferably, the Rf group is a perfluoroalkyl group.
More preferably, Z is a linear or branched alkylene group having 2-6 carbon atoms, preferably is -CH 2 CH 2 -; and
Rf is a linear or branched perfluoroalkyl group having 6-12 carbon atoms, preferably is a linear perfluoroalkyl group having 8-10 carbon atoms.
Specific examples of the fluoroalkyl group-containing (meth)acrylate are as follows:
CF 3 (CF 2 ) 7 (CH 2 ) 10 OCOCH=CH 2
CF 3 (CF 2 ) 7 (CH 2 ) 10 OCOC(CH 3 )=CH 2
CF 3 (CF 2 ) 6 CH 2 OCOCH=CH 2
CF 3 (CF 2 ) 8 CH 2 OCOC(CH 3 )=CH 2 (CF 3 ) 2 CF(CF 2 ) 6 (CH 2 ) 2 OCOCH=CH 2
(CF 3 ) 2 CF(CF 2 ) 8 (CH 2 ) 2 OCOCH=CH 2
(CF 3 ) 2 CF(CF 2 ) 10 (CH 2 ) 2 OCOCH=CH 2
(CF 3 ) 2 CF(CF 2 ) 6 (CH 2 ) 2 OCOC(CH 3 )=CH 2
(CF 3 ) 2 CF(CF 2 ) 8 (CH 2 ) 2 OCOC(CH 3 )=CH 2
(CF 3 ) 2 CF(CF 2 ) 10 (CH 2 ) 2 OCOC(CH 3 )=CH 2
CF 3 CF 2 (CF 2 ) 6 (CH 2 ) 2 OCOCH=CH 2
CF 3 CF 2 (CF 2 ) 8 (CH 2 ) 2 OCOCH=CH 2
CF 3 CF 2 (CF 2 ) 10 (CH 2 ) 2 OCOCH=CH 2
CF 3 CF 2 (CF 2 ) 6 (CH 2 ) 2 OCOC(CH 3 )=CH 2
CF 3 CF 2 (CF 2 ) 8 (CH 2 ) 2 OCOC(CH 3 )=CH 2
CF 3 CF 2 (CF 2 ) 10 (CH 2 ) 2 OCOC(CH 3 )=CH 2
Other than the fluorine monomer mentioned above, the monomer composition to be polymerized preferably further comprises at least 30 wt% of at least one hydrophobic monomer selected from C 8 -C 40 , preferably Ci 0 -C 24 , more preferably Ci 3 -C 22 alkyl (meth)acrylates, C 8 -C 0 , preferably Ci 0 -C 2 , more preferably Ci 3 -C 22 alkyl acyloxy vinyl esters.
In some embodiments of the present invention, the monomer composition comprises:
a) 30-70 wt% of at least one fluorine-containing monomer selected from (C 6 - Ci 2 perfluoroalkyl) (C 2 -C 6 alkylene) (meth)acrylates,
b) 30-70 wt% of at least one hydrophobic monomer selected from Ci 2 -C 2 , preferably Ci 3 -C 22 alkyl (meth)acrylates,
c) 0-30 wt% of at least one monomer selected from vinyl chloride, (meth)acrylic acid, hydroxyl esters, poly(alkylene glycol) ether esters, Ci-C 5 alkyl terminated poly(alkylene glycol) ether esters, glycidyl esters, and alkyl tertiary amino esters of (meth)acrylic acid; (meth)acrylamide, N-alkylol (meth)acrylamide, N-alkyl tertiary amino (meth)acrylamide; salt of alkyl tertiary amino esters of (meth)acrylic acid and N-alkyl tertiary amino (meth)acrylamide; Ci-C 5 alkyl acyloxy vinyl esters; vinyl siloxane, (meth)acyloxy siloxane; self-crosslinkable monomers, such as diacetone acrylamide and acetoacetoxyethyl (meth)acrylate; and polyethylenically unsaturated monomers.
Preferably, the monomer composition comprises:
a) 30-65 wt% of at least one fluorine-containing monomer selected from 2- (perfluorohexyl)ethyl (meth)acrylate and 2-(perfluorooctyl)ethyl (meth)acrylate; b) 30-65 wt% of at least one hydrophobic monomer selected from hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, eicosyl (meth)acrylate and docosyl (meth)acrylate;
c) 5-20 wt% of at least one monomer selected from hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, (meth)acrylamide, N-methylol (meth)acrylamide and vinyl chloride.
Polymerization is usually effected using at least one initiator. At least one initiator may be a peroxide. Examples of suitable peroxides are alkali metal peroxodisulfates such as, for example, potassium peroxodisulfate, sodium peroxodisulfate, ammonium peroxodisulfate, hydrogen peroxide, organic peroxides, such as diacetyl peroxide, di-tert-butyl peroxide, diamyl peroxide, dioctanoyl peroxide, didecanoyl peroxide, dilauroyl peroxide, dibenzoyl peroxide, bis(o-toluoyl) peroxide, succinyl peroxide, tert-butyl peracetate, tert- butyl permaleate, tert-butyl perisobutyrate, tert-butyl perpivalate, tert-butyl peroctanoate, tert-butyl pemeodecanoate, tert-butyl perbenzoate, di-tert-butyl peroxide, tert-butyl hydroperoxide, cumyl hydroperoxide, tert-butyl peroxy-2- ethylhexanoate and diisopropyl peroxidicarbamate. Azo compounds, such as, for example, azobisisobutyronitrile, l-[(l-cyano-l-methylethyl)azo]formamide, 2,2'-azobis{2-methyl-N-[2-(l-hydroxybutyl)]propionamide}, 2,2'-azobis[2- methyl-N-(2-hydroxyethyl)-propionamide] , 2,2 ' -azobis {2-methyl-N- [1,1- bis(hydroxymethyl)-2-hydroxyethyl]propionamide } , 2,2 ' -azobis( 1 -imino- 1 - pyrrolidino-2-methylpropane)dihydrochloride, azobis(2-amidopropane) dihydrochloride and 2,2'-azobis(2-methylbutyronitrile) are also suitable.
Redox initiators are likewise suitable, for example comprising peroxides and oxidizable sulfur compound. Systems comprising acetone bisulfite and organic peroxide, such as tert-C 4 H 9 -OOH, Na 2 S 2 0 5 (sodium disulflte) and organic peroxide, such as tert-C H 9 -OOH or HO-CH 2 S0 2 Na, and organic peroxide, such as tert-C H 9 -OOH, can be used. Systems such as ascorbic acid/H 2 0 2 can also be used.
Macro initiators having same or similar initiating groups as the above mentioned compounds can also be used. Macro initiators are, for example, 4,4'- (l,2-diazenediyl)bis[4-cyano-, polymer with a-hydro-ct)-hydroxypoly(oxy- 1 ,2- ethanediyl) pentanoic acid, (VPE0201, VPE0401, and VPE0601, all from Wako Pure Chemical Industries, Ltd., CAS No.: 105744-24-9), 4,4'-azobis[4-cyano-, polymer with -[(3-aminopropyl)dimethylsilyl]-ro-[[(3-aminopropyl)dimethyl - silyl]oxy]poly[oxy(dimethylsilylene)] pentanoic acid (VPS0501 and VPS 1001, both from Wako Pure Chemical Industries, Ltd., CAS No.: 158947-07-0).
It is possible to use at least one emulsifler which may be anionic, cationic or nonionic.
Customary nonionic emulsiflers are, for example, ethoxylated mono-, di- and trialkylphenols (degree of ethoxylation: 3 to 50, alkyl radical: C4-Q2) and ethoxylated fatty alcohols (degree of ethoxylation: 3 to 80; alkyl radical: C 8 - C 35 ). Examples are Emulsogen®, Genapol® and Sapogenat® from Clariant, Lutensol® from BASF and Triton® from Dow. Emulsiflcation capability is usually affected and limited by cloud point for nonionic emulsiflers. Consequently, nonionic emulsiflers can be selectively comprised in recipe, or used as post-add after polymerization. Nevertheless, those ones with high cloud point are preferable for high temperature polymerization.
Customary anionic emulsiflers are, for example, alkali metal and ammonium salts of alkyl sulfates (alkyl radical: C 8 to Ci 2 ), of sulfuric acid monoesters of ethoxylated alkanols (degree of ethoxylation: 4 to 50, alkyl radical: C 4 -Ci 8 ) and of ethoxylated alkylphenols (degree of ethoxylation: 4 to 50, alkyl radical: C 4 - Cis), of alkanesulfonic acids (alkyl radical: C 4 -Ci 8 ), of alkylarylsulfonic acids (alkyl radical: C9-C13), and of ethoxylated alkanols (degree of ethoxylation: 4 to 50, alkyl radical: C -Ci 8 ) phosphorous acids.
Suitable cationic emulsiflers are as a rule primary, secondary, tertiary or quaternary ammonium salts having a C 6 -Ci 8 -alkyl, C 6 -Ci 8 -aralkyl or heterocyclic radical, alkanolammonium salts, pyridinium salts, imidazolinium salts, oxazolinium salts, morpholinium salts, thiazolinium salts and salts of amine oxides, quinolinium salts, isoquinolinium salts, tropylium salts, sulfonium salts and phosphonium salts. Dodecylammonium acetate or the corresponding hydrochloride, the chlorides or acetates of various 2-(N,N,N- trimethylammonium)ethylparafflnic acid esters, N-cetylpyridinium chloride, N- laurylpyridinium sulfate and N-cetyl-N,N,N-trimethylammonium bromide, N- dodecyl-N,N,N-trimethylammonium bromide, N,N-distearyl-N,N-dimethyl- ammonium chloride and the Gemini surfactant N,N-(lauryldimethyl)ethylene- diamine dibromide may be mentioned by way of example. Numerous further examples appear in H. Stache, Tensid-Taschenbuch, Carl-Hanser-Verlag, Munich, Vienna, 1981, and in McCutcheon's, Emulsiflers & Detergents, MC Publishing Company, Glen Rock, 1989.
Reactive emulsiflers or polymerizable emulsiflers can also be used to form stable emulsion in the present invention. These emulsiflers have polymerizable groups like unsaturated ethylene groups and can be incorporated into the final polymer. Examples of these emulsiflers include sodium ethylenesulphonate, 2- acrylamido-2-methyl-l-propanesulfonic acid sodium salt, 3-allyloxy-2- hydroxy-l-propanesulfonic acid sodium salt, polyethylene glycol (meth)acrylate.
In the polymerization reaction of the polymerizable monomers, a chain transfer agent may be incorporated with a purpose of controlling the molecular weight. The chain transfer agent is preferably an aromatic compound or a mercaptan, particularly preferably an alkyl mercaptan. As specific examples of the chain transfer agent, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, stearyl mercaptan and -methylstyrene dimer.
Further additives which are customary in emulsion polymerization may be added to the reaction mixture, for example glycols, polyethylene glycols, protective colloids and buffer/pH regulators.
When the monomers are not completely compatibilized, a compatibilizing agent (e.g., a water-soluble organic solvent) capable of sufficiently compatibilizing them is preferably added to these monomers. By the addition of the compatibilizing agent, the emulsiflability and polymerizability can be improved.
Examples of the water-soluble organic solvent include acetone, methyl ethyl ketone, ethyl acetate, propylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol, tripropylene glycol and ethanol.
A duration in the range from 30 minutes to 12 hours, preferably from 2 to 8 hours, may be chosen as the duration for the emulsion polymerization.
Preferably, the process of the present invention is carried out at a temperature of 95-180°C, more preferably 100-170°C, particularly preferably 120-140°C.
Preferably, the process of the present invention is carried out under a pressure of l-30atm, preferably l-20atm, more particularly preferably 1-lOatm.
In an embodiment of the present invention, a post polymerization is effected, for example by addition of initiator which is identical or different from the initiator used in the actual copolymerization.
In an embodiment of the present invention, the emulsion polymerization takes place substantially completely.
The emulsion polymerization process of the present invention can achieve high fluorine-containing monomer conversion, thus the incorporation of fluorine- containing monomer in the final polymer can be significantly increased.
The present invention is advantageous in that it provides a novel and feasible method to polymerize fluorine-containing monomer into emulsion polymers. Apart from other costly techniques, high polymerization temperature makes transfer barrier low enough for fluorine-containing monomer. Even larger quantities of fluorine-containing monomers could be polymerized. These emulsion polymers and coating composition thereafter get much lower or even no VOC.
The emulsion polymer obtained from the process of the present invention can be used in preparing water and oil repellent agents.
The thus obtained polymer can be diluted or dispersed with water or an organic solvent if necessary, and then prepared in an arbitrary form such as an emulsion, a solution in an organic solvent and an aerosol to give the water- and oil- repellent agent. The polymer functions as an effective component (an active ingredient) of the water- and oil-repellent agent. The water- and oil-repellent agent comprises the fluorine-containing polymer and a medium (particularly a liquid medium) (for example, an organic solvent and/or water).
Examples
Chemicals
Initiators
2,2'-azobis[2-methylpropionamidine] dihydrochloride (V50, Wako)
2,2'-Azobis[2-methyl-N-(2-hydroxyethyl)propionamide] (VA-086, Wako) Emulsifiers
Octylphenol ethoxylate (Triton ® X305, Dow)
Octadecy trimethyl ammonium chloride (OTAC, Sinopharm Chemical Reagent Co., Ltd.)
Monomers
2-(perfluorooctyl)ethyl methacrylate (C8FMA, Hengtong Fluorine Co., Ltd.) 2-(perfluorohexyl)ethyl methacrylat (C6FMA, Hengtong Fluorine Co., Ltd.) C1 6 -C1 8 alkyl esters of methacrylic acid (Visiomer ® CI 7.4-MA*, Evonik) 2-hydroxyethyl methacrylate (2-HEMA, Evonik )
N-methylol methacrylamide (N-MMAA, Evonik)
Vinyl chloride
* Visiomer ® CI 7.4-MA is a mixture of C1 6 -C1 8 alkyl esters of methacrylic acid.
Neutralizing agent
Acetic acid
Solvent
Deionized water (DW)
Tripropylene glycol (TPG)
Examples 1-6
A 1 -liter, jacketed pressure reactor was equipped with a paddle stirrer, a thermometer, a nitrogen inlet, a feeding line, a vent valve and a pressure meter (including a pressure relief system).
Air in the kettle was replaced by nitrogen gas before experiment. A precharge prepared by mixing the components indicated in Table 1 was charged and heated to 120°C.
A monomer emulsion was prepared by mixing the components indicated in Table 2. A seed emulsion prepared by mixing the components indicated in Table 3 was pumped into the kettle. The content of the kettle was stirred for 30min.
The rest of the monomer emulsion was transferred to the kettle in 4h and a mixture of 0.72g of VA-086 dissolved in 40g of deionized water was co-fed to the reactor in 4.5h. During the feeding of the monomer emulsion, 38.91g of vinyl chloride (VCM) was added to reaction kettle by 4 times (9.73g of VCM at the beginning of each feeding hour).
The temperature of the reaction mixture was allowed to increase to 130°C. After the completion of feeding, the mixture was held for lh. Then a chaser mixture of 0.50g of VA-086 dissolved in 20g of DW was added to the kettle. The reaction mixture was held for another 2h for post-polymerization and then cooled to room temperature. The mixture was neutralized by 0.72g of acetic acid and filtered to remove any coagulation formed.
The emulsion of the examples was translucent and milky with coagulum less than 1 % of total solid.
Comparative Example 1
This comparative example was conducted by mini-emulsion polymerization process.
A monomer emulsion was prepared by homogenizing the ingredients indicated in Table 1 with a high pressure homogenizer at 50°C for 45min. The resulted monomer emulsion mixture had a particle size about 162.7nm. It was charged to a 1L pressure reactor. The emulsion was maintained under nitrogen gas at 60°C for 30min. Then 38.91g of vinyl chloride was charged into reactor, followed by 0.92g V50 dissolved in 30g de-ionized water. The emulsion was stirred at 60°C for another 4h. Then the emulsion was cooled to room temperature and filtered to remove any coagulate formed.
Comparative Example 2
Comparative Example 2 had a similar formulation as Example 1 but was carried out at a lower reaction temperature of about 80°C with initiator V50. This example came out with huge coagulum and an unreacted monomer phase at the bottom of reactor. Coagulum was 92.03g (26.7% of total solid) after drying and unreacted monomer was 86.28g (25.0% of total solid). Table 1 Kettle rechar e
Table 2 Monomer emulsion (ME)
Table 3 Seed emulsion
Physical property of the resulted emulsion polymers
The aqueous emulsions each obtained were measured for solid content, pH value, particle size, which are indicated in Table 4.
Solid content was measured in a halogen moisture analyzer (Mettler Toledo HG63 Halogen) at 140°C.
Particle size was measured in a distribution analyzer (Beckman Coulter Delsa Nano S) for 70 cycles. Table 4 Physical property
Performance test of the emulsion polymers
Treatment of textile fabrics
Each aqueous emulsion was diluted to 0.2% with DW. A cotton fabric, a cotton-polyester mixed fabric, a polyester fabric, or a nylon fabric were immersed therein, and then squeezed with a mangle. The wet pick-up after squeezing was indicated in Table 5. The fabrics were pre-dried at 80°C for 3min and heated at 150°C for 3min. After that, fabrics were ready for test.
Table 5 Wet pick-up
Water-repellency test
Water-repellency was evaluated by spray test according to ISO 4920 and rated according to ISO 4920 as indicated in Table 6.
Table 6 Water-repellency rating
Oil-repellency test
Oil-repellency of textile was evaluated by hydrocarbon resistance test according to ISO 14419, which showed substrate's resistance to absorption of a selected series of liquid hydrocarbons of different surface tensions.
A drop of the test liquid indicated in Table 7 was dropped onto an oil repellent treated fabric. If the droplet remains on the fabric after standing for 30 seconds as indicated in Table 8, the test liquid passes the test, and a test liquid with a higher point was used to for test. The oil-repellency is expressed by the maximum point of the test liquid which passes the test. The oil-repellency is evaluated as nine levels which are 0, 1, 2, 3, 4, 5, 6, 7 and 8 in order of a poor level to an excellent level.
Table 7 Oil-repellency test liquid
Table 8 Criteria for pass or fail in oil-repellency test
The result of water and oil repellency tests is indicated in Table 9 below. Water and oil repellency durability test
The above treated fabrics were washed 5 times or 10 times according to the water washing method defined in ISO 6330 and then air-dried, followed by- water and oil repellency tests again. The results are indicated in Tables 10 and 11.
It can be seen from Table 9-11. Textile fabric turned repellent to water and oil after treated with emulsion respectively obtained in Examples 1 to 6. No wetting was found on surfaces of cotton fabric, cotton-polyester mixed fabric, polyester fabric and nylon fabric. These results of repellency power also had durability after washing 5 or 10 times.
An emulsion, with the same content of fluorine-containing monomer as Ex. 1 , was also presented in comparative example 5, where monomers mixture was sheared at extremely critical condition to be dispersed into nano-droplets before polymerization. Compared to Comp. Example 1, Example 1 had nearly equivalent repellency to water and oil before the washing test, but Example 1 had better durability for water and oil repellency against washing.
Table 9 Water-repellency / oil-repellency
Table 10 Water-repellency / oil-repellency after 5 times of wash
Table 11 Water-repellency / oil-repellency after 10 times of wash
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