Environmentally friendly waterproof and oil-proof emulsion with excellent washing durability and preparation method thereof

Abstract

The present invention relates to the technical field of functional finishing agents for textiles, specifically an environmentally friendly waterproof and oil-proof emulsion with excellent wash resistance and a preparation method thereof. The waterproof and oil-proof emulsion comprises 10-30% fluorinated copolymer, 50-70% deionized water, 1-10% emulsifier, and 1-10% cosolvent. The fluorinated copolymer comprises 20-60% fluorinated monomer, 10-30% long-chain alkyl acrylate, 1-20% chlorinated monomer, and 1-30% crosslinking monomer. The fluorinated monomers comprise a combination of two or more monomers, one of which must have a melting point (Tm) greater than 80°C and a chlorinated monomer content of 10-40%, and the other must have a glass transition temperature (Tg) less than 20°C and a chlorinated monomer content of 10-20%. Compared to existing technologies, this waterproof and oil-proof agent exhibits excellent wash resistance and reaches or even exceeds the performance of eight-carbon water-repellents.

Description

Technical Field

[0001] The present invention relates to the technical field of functional finishing agents for textiles, in particular to an environmentally friendly waterproof and oil-proof emulsion with excellent washing durability and a preparation method thereof. Background Art

[0002] As we all know, the mainstream water and oil repellent in the textile industry is still fluorinated acrylic emulsions. Although non-fluorinated water repellents, such as paraffin and silicone-based ones, have emerged in recent years, their performance still cannot match that of fluorinated water repellents, and non-fluorinated water repellents offer little to no oil repellency. Currently, non-fluorinated water repellents hold less than 10% of the market share. Unless a client specifies a non-fluorinated water repellent, fluorinated water repellents remain the preferred choice. Currently, C8 water and oil repellents dominate fluorinated water repellents, primarily due to the crystallization of the side chains of the 8-carbon fluorinated monomers, resulting in superior water and oil repellency. Current research indicates that the dynamic contact angle, particularly the receding contact angle, is not the static contact angle that determines surface properties. Due to the crystallinity of the 8-carbon side chains, the receding contact angle of these monomers is significantly higher than that of shorter-chain fluorinated monomers with 7 or fewer carbon atoms. However, the 8-carbon fluorinated monomers can transform into PFOA, which has been shown to be highly bioaccumulative and difficult to degrade.

[0003] Fiber products treated with water-repellent agents are widely used in everyday clothing, outdoor sportswear, and medical textiles. As people's living standards improve, there is a growing demand for further improvements in the water-repellency, oil-repellency, and softness of these fiber products. In particular, the need to maintain these properties over a long period of time, i.e., the demand for wash durability, is becoming increasingly stringent.

[0004] In order to solve the problem of durability after washing, Japanese Patent Application Laid-Open Nos. 2000-212549 and 2000-282016 disclose the effectiveness of specific cross-linking monomers.

[0005] In order to improve the washing durability, the patent document (CN106536622A) compounded a blocked isocyanate cross-linking agent into the waterproofing agent when treating the fabric to improve the washing durability.

[0006] Some patent documents also disclose the use of vinyl chloride and vinylidene chloride to improve the washing durability of waterproofing agents, which is also improved to a certain extent compared to waterproofing agents that do not use vinyl chloride and vinylidene chloride.

[0007] However, the above methods can only improve the washing durability to a certain extent. Conventional short-chain fluorinated monomers, such as C4 and C6, have structural defects that initially have a certain gap compared to C8 waterproofing agents. Therefore, in terms of washing durability, they still cannot achieve the washing durability performance of conventional C8 waterproofing agents. Summary of the Invention

[0008] (1) Technical problems solved

[0009] In response to the shortcomings of the existing technology, the present invention provides an environmentally friendly waterproof and oil-proof emulsion with excellent washing durability, as the existing conventional short-chain fluorinated monomers cannot reach the level of C8 water-proof agents. Although C6 or C4 fluorinated monomers are used, the washing durability performance of the conventional C8 water-proof agent can still be achieved.

[0010] (2) Technical solution

[0011] To achieve the above object, the present invention provides the following technical solutions:

[0012] An environmentally friendly waterproof and oil-proof emulsion with excellent washing durability, comprising, by mass fraction:

[0013] Fluorinated copolymer 10-30%,

[0014] Deionized water 50-70%,

[0015] Emulsifier 1-10%,

[0016] Cosolvent 1~10%.

[0017] Further: According to mass fraction, the fluorine-containing copolymer comprises:

[0018] Fluorine-containing monomer 20-60%,

[0019] Long chain alkyl acrylate 10-30%,

[0020] Chlorine-containing monomers 1-20%,

[0021] Cross-linking monomer 1~30%.

[0022] Preferably: the fluorine-containing monomer is composed of two fluorine-containing monomers, one of which has a melting point greater than 80°C and a content of 10-40% in the fluorine-containing copolymer;

[0023] Another fluorine monomer has a glass transition temperature of less than 20°C and its content in the fluorine-containing copolymer is 10-20%.

[0024] Preferably, the side chain length of the long-chain alkyl acrylate is 12 to 30.

[0025] Preferably, the chlorine-containing monomer is vinyl chloride monomer or vinylidene chloride monomer.

[0026] Preferably, the cross-linking monomer is an acrylate monomer with two functional groups, a monomer having a C=C compound and a reactive functional group.

[0027] Preferably, the cross-linking monomer is one or more of hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, epoxy (meth)acrylate, diacetone (meth)acrylamide, N-hydroxymethylacrylamide, 3-chloro-2-hydroxypropyl (meth)acrylate, and glycidyl (meth)acrylate.

[0028] Preferably, the emulsifier is composed of a cationic emulsifier and a nonionic emulsifier, wherein the cationic emulsifier accounts for 30-60% of the emulsifier and has the structural formula of R(CH3)3N + X - , wherein R is a long-chain alkyl group of 12-18, X is a halogen atom of chlorine or bromine; the nonionic emulsifier is a surfactant with an alkyl polyoxyethylene ether structure, and the general formula is RO(CH2CH2O) n H, wherein R is a long-chain alkyl group of 12-20, n is 3-50, and the proportion in the emulsifier is 40-70%.

[0029] Preferably, the co-solvent is a high-boiling-point alcohol solvent having a boiling point higher than 150° C., which is one or more of propylene glycol, dipropylene glycol, and tripropylene glycol.

[0030] On the other hand, the present invention also discloses a method for preparing an environmentally friendly waterproof and oil-proof emulsion with excellent washing durability, comprising the steps of:

[0031] 1) The melting point of the homopolymer T m Greater than 80°C fluorine monomer, homopolymer glass transition temperature T g A fluorinated copolymer composed of a fluorinated monomer at a temperature below 20°C, a long-chain alkyl acrylate, a chlorine-containing monomer, and a cross-linking monomer;

[0032] 2) Preheating the fluorinated copolymer prepared in step 1), deionized water, an emulsifier, and a cosolvent in a 60°C water bath for 40 to 60 minutes, pre-dispersing the mixture under mechanical stirring, and finally homogenizing the mixture under a high-pressure homogenizer to obtain a metastable emulsion with a particle size of less than 150 nm, wherein the sum of the mass percentages of the fluorinated copolymer, deionized water, emulsifier, and cosolvent used is 100%;

[0033] 3) introducing the emulsion obtained in step 2) into a closed autoclave with mechanical stirring, pressurizing the chlorine-containing monomer, and when the temperature rises to 50-80° C., adding a chain transfer agent, dodecyl mercaptan, in an amount of 0.1-0.5% of the comonomer and an initiator in an amount of 0.4-2.0% of the comonomer. The polymerization reaction is carried out for 3-6 hours, and finally the temperature is lowered to room temperature and filtered to obtain a fluorine-containing polymer emulsion.

[0034] Preferably, the initiator is one or a combination of water-soluble azobisisobutylamidine hydrochloride, ammonium persulfate, and potassium persulfate.

[0035] Preferably, the initiator may also be an azo or peroxide type oil-soluble initiator.

[0036] The copolymer emulsion obtained by the technical solution of the present invention is translucent with blue light, the particle size of the polymer emulsion is in the range of 50 to 150 nm, and the molecular weight of the fluorine-containing polymer is in the range of 10,000 to 100,000.

[0037] (3) Beneficial effects

[0038] The fluorine-containing emulsion with excellent washing durability obtained by the present invention introduces two or more different T g or T m Environmentally friendly fluorinated monomers, which produce the following effects:

[0039] 1. The fluorinated monomers used in the present invention are C6 or C4 fluorinated monomers, and do not contain C8 or above components with strong environmental accumulation;

[0040] 2. T used in the present invention m Greater than 80 ° C fluorinated monomers, improve the advancing contact angle of the polymer, that is, improve the anti-reconstruction property of the polymer film; at the same time, the use of T g Fluorine-containing monomers with a temperature lower than 20°C improve the film-forming property of the polymer film and also increase the contact angle of the polymer film to oil. g or T m The fluorinated monomer improves the contact angle to water and oil, the anti-reconstruction performance of the polymer film, and improves the softness of the film, and the softness of the film is conducive to improving the washing durability. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0042] The raw materials used in the Examples and Comparative Examples are all commercially available industrial products and can be purchased through commercial channels.

[0043] Different T g and T m The fluorinated monomers are shown in Table 1.

[0044]

[0045] Among them, C6NSFA has two Tm, Tm=107℃ is the first transition temperature, and Tm=182℃ is the second transition temperature.

[0046] Example 1

[0047] Add the following components into a 500ml plastic beaker: C6NSFA 40g, C4FA 20g, octadecyl acrylate (C18A) 17g, N-hydroxymethyl acrylamide (NMA) 3g, nonionic emulsifier C 12 H 25 O(CH2CH2O) 20 H 6g, cationic emulsifier C 18 H 37 N + (CH3)3CL - 4g, tripropylene glycol 20g, deionized water 200g, then placed in 60 DEG C of water-baths and heated 40 minutes, dispersion machine disperses 4 minutes, rotating speed 2000rpm / m, then placed in high pressure homogenizer and homogenizes 10 minutes, homogenizing pressure 400kg, obtains stable oil-in-water type miniemulsion, median particle size is 150nm.Then this emulsion is poured in the autoclave equipped with agitator, after nitrogen replacement, is pressed into vinyl chloride (VCM) 25 grams, then adds initiator azobisisobutylamidine hydrochloride 0.5g and lauryl mercaptan 0.2g, water temperature rises to 75 DEG C simultaneously, reacts after 6 hours, obtains stable aqueous polymer dispersion.Tested by GC, monomer conversion is more than 99%; By F analytical calculation, vinyl chloride monomer conversion is 80%.

[0048] Example 2

[0049] The C4FA in Example 1 was replaced by C6FA, and octadecyl acrylate was replaced by behenyl acrylate (C22A). Other components were the same as in Example 1.

[0050] Example 3

[0051] The C6NSFA in Example 1 was replaced by C6SMFA, and octadecyl acrylate was replaced by behenyl acrylate. Other aspects were the same as in Example 1.

[0052] Example 4

[0053] The C6NSFA in Example 2 was replaced with C6SMFA, and the rest was the same as Example 1.

[0054] Example 5

[0055] The C6NSFA in Example 1 was replaced with C6SFA, and the rest was the same as Example 1.

[0056] Example 6

[0057] The amount of C4FA used was adjusted from 20 g to 10 g and the amount of C6FA used was adjusted to 10 g. Other procedures were the same as in Example 1.

[0058] Comparative Example 1

[0059] The two fluorine monomers in Example 1 were replaced with C6FMA, and the rest were the same as in Example 1.

[0060] Comparative Example 2

[0061] The two fluorine monomers in Example 1 were replaced with C4FMA, and the rest were the same as in Example 1.

[0062] Comparative Example 3

[0063] The two fluorine monomers in Example 1 were replaced with C8FA, and the rest were the same as in Example 1.

[0064] Comparative Example 4

[0065] The two fluorine monomers in Example 1 were replaced with a single fluorine monomer C6NSFA, and the rest were the same as in Example 1.

[0066] The two fluorine monomers in Example 1 were replaced with a single fluorine monomer C6SFA, and the rest were the same as in Example 1.

[0067] The amount of each monomer is shown in Table 2:

[0068]

[0069] The test was carried out on three kinds of fabrics (nylon, polyester and cotton) at a test concentration of 4.0%. The crosslinking agent was blocked isocyanate type BN-69 at a dosage of 1%. The test was carried out by dipping and padding at 170°C for 2 minutes, and then the water and oil repellency was evaluated.

[0070] Water and oil repellent washing durability:

[0071] Repeat washing 10 or 20 times according to the AATCC-35 washing method, and then evaluate the water and oil repellency (HL5, HL10, HL20). HL0 refers to the evaluation without washing.

[0072] Water repellency test:

[0073] The test standard is AATCC-22. Using a water spray test device, 250ml of tap water is poured onto the test object within 25 seconds. The fabric wetting state is observed and the water repellency is evaluated. The test results are as follows:

[0074] 100 points: The surface is not wetted and water droplets do not adhere;

[0075] 90 points: The surface is not wet, but there are small water droplets attached;

[0076] 80 points: The surface is wet in the form of water droplets;

[0077] 70 points: The surface is substantially wetted;

[0078] 50 points: The surface is almost completely wetted;

[0079] 0 points: Both the front and back sides are moistened.

[0080] Oil repellency test:

[0081] The test standard is AATCC-118: First, carefully apply five 0.05 mL drops of the lowest-numbered test liquid to the specimen. If no penetration or wetting occurs within 30 seconds, apply a higher-numbered test liquid. The test continues until the test liquid wets the specimen below or around the drop within 30 seconds. The oil repellency rating of the specimen is determined by the highest-numbered test liquid for which three drops fail to wet the specimen within 30 seconds. The rating is shown in the table below.

[0082] The oil-proof test liquid is shown in Table 3:

[0083]

[0084] Hand feel test:

[0085] Place the fabric to be tested in a constant temperature and humidity room at 25°C±2°C and 65%±2% for 24 hours, and then evaluate its softness by hand using the following standards.

[0086] O: soft;

[0087] △: average;

[0088] ×: Hard.

[0089] The test results are shown in Table 4:

[0090]

[0091] In summary, the use of two or more fluoromonomers with different Tg and Tm for polymerization is significantly better than the product obtained by polymerizing one conventional fluoromonomer in terms of washing durability and hand feel.

Claims

1. An environmentally friendly water- and oil-proof emulsion with excellent washing durability, characterized by: According to quality score, including: Fluorinated copolymer 10-30%, Deionized water 50-70%, Emulsifier 1-10%, Cosolvent 1-10%; The fluorinated copolymer contains a fluorinated monomer, which is composed of two fluorinated monomers, wherein the melting point of the homopolymer of one fluorinated monomer is greater than 80°C and the content of the fluorinated copolymer is 10-40%; Another fluorinated monomer has a homopolymer with a glass transition temperature of less than 20°C and a content of 10-20% in the fluorinated copolymer. In terms of mass fraction, the fluorinated copolymer comprises: Fluorine-containing monomer 20-60%, Long chain alkyl acrylate 10-30%, Chlorine-containing monomers 1-20%, Cross-linking monomer 1~30%, The side chain length of the long-chain alkyl acrylate is 12 to 30.

2. The environmentally friendly waterproof and oil-proof emulsion with excellent washing durability according to claim 1, characterized in that: The chlorine-containing monomer is vinyl chloride monomer or vinylidene chloride monomer.

3. The environmentally friendly waterproof and oil-proof emulsion with excellent washing durability according to claim 2, characterized in that: The cross-linking monomer is an acrylate monomer with two functional groups, and the acrylate monomer is a monomer with a C=C double bond functional group and a reactive functional group.

4. The environmentally friendly waterproof and oil-proof emulsion with excellent washing durability according to claim 3, characterized in that: The crosslinking monomer is one or more of hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, epoxy (meth)acrylate, diacetone (meth)acrylamide, N-hydroxymethylacrylamide, 3-chloro-2-hydroxypropyl (meth)acrylate, and glycidyl (meth)acrylate.

5. The environmentally friendly waterproof and oil-proof emulsion with excellent washing durability according to claim 1, characterized in that: The emulsifier is composed of cationic emulsifier and nonionic emulsifier, wherein the cationic emulsifier accounts for 30-60% of the emulsifier and has the structural formula of R(CH3)3N + X - , wherein R is a long-chain alkyl group of 12-18, X is a halogen atom of chlorine or bromine; the nonionic emulsifier is a surfactant with an alkyl polyoxyethylene ether structure, and the general formula is RO(CH2CH2O) n H, wherein R is a long-chain alkyl group of 12-20, n is 3-50, and the proportion in the emulsifier is 40-70%.

6. The environmentally friendly water- and oil-proof emulsion with excellent washing durability according to claim 1, characterized in that: The cosolvent is a high-boiling-point alcohol solvent with a boiling point higher than 150° C., and is one or more of propylene glycol, dipropylene glycol, and tripropylene glycol.

7. The method for preparing an environmentally friendly waterproof and oil-proof emulsion having excellent washing durability according to any one of claims 1 to 6, characterized in that: Including steps: 1) The melting point of the homopolymer T m Greater than 80°C fluorine monomer, homopolymer glass transition temperature T g A fluorinated copolymer composed of a fluorinated monomer at a temperature below 20°C, a long-chain alkyl acrylate, a chlorine-containing monomer, and a cross-linking monomer; 2) Preheating the fluorinated copolymer prepared in step 1), deionized water, an emulsifier, and a cosolvent in a 60°C water bath for 40 to 60 minutes, pre-dispersing the mixture under mechanical stirring, and finally homogenizing the mixture under a high-pressure homogenizer to obtain a metastable emulsion with a particle size of less than 150 nm, wherein the sum of the mass percentages of the fluorinated copolymer, deionized water, emulsifier, and cosolvent used is 100%; 3) introducing the emulsion obtained in step 2) into a closed autoclave with mechanical stirring, pressurizing the chlorine-containing monomer, and when the temperature rises to 50-80° C., adding a chain transfer agent, dodecyl mercaptan, in an amount of 0.1-0.5% of the comonomer and an initiator in an amount of 0.4-2.0% of the comonomer. The polymerization reaction is carried out for 3-6 hours, and finally the temperature is lowered to room temperature and filtered to obtain a fluorine-containing polymer emulsion.

8. The method for preparing an environmentally friendly waterproof and oil-proof emulsion with excellent washing durability according to claim 7, characterized in that: The initiator is one or a combination of water-soluble azobisisobutylamidine hydrochloride, ammonium persulfate and potassium persulfate.

9. The method for preparing an environmentally friendly waterproof and oil-proof emulsion with excellent washing durability according to claim 7, characterized in that: The initiator is an oil-soluble initiator of azo type or peroxide type.

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