CN109422861A - Fluorine-free water-drawing agent and preparation method thereof - Google Patents

Abstract

The invention provides a method for preparing a fluorine-free water-drawing agent, which comprises the following steps: step (a): carrying out polymerization reaction on a diol compound with a carboxylic group, a chain extender and polyisocyanate in an organic solvent to obtain a first mixture containing a polyurethane prepolymer; wherein the chain extender is polyester diol, polyether diol, polysilicone diol or a combination thereof; the molar ratio of the total hydroxyl groups of the diol compound with the carboxylic acid group and the chain extender to the total isocyanate groups of the polyisocyanate is 1: 1.2 to 1: 2; step (b): adding a dendritic polyol to the first mixture, and reacting the dendritic polyol with the polyurethane prepolymer in the first mixture to obtain a second mixture; and step (c): adding fatty alcohol into the second mixture for end-capping reaction to obtain a fluorine-free water drawing agent; the invention also provides a fluorine-free water repellent prepared by the method.

Description

Fluorine-free water repellent and preparation method thereof

technical field

The present invention relates to a fluorine-free water-repellent agent and a preparation method thereof, in particular to a fluorine-free water-repellent agent for textiles and a preparation method thereof.

Background technique

The textile industry has long used perfluorinated compounds such as TEFLON developed by DuPont as a water-repellent finishing agent for fabrics. However, related studies have found that perfluorinated compounds contained in clothes are carcinogenic and toxic, and may cause pregnant women to give birth to deformed children; not only that, perfluorinated compounds have the characteristics of being difficult to decompose, causing them to persist and accumulate in animals and plants. However, it circulates in the natural environment for a long time; in view of the danger of perfluorinated compounds, the European Union, the United States and other regions have strictly restricted the use of perfluorinated compounds. Aqueous agents have become an important issue.

In order to solve the above problems, it has been proposed to coat the surface of the fabric with a solution of nano metal particles with lotus effect to form an isolation layer with a water repellent effect. However, the nano metal particle materials have to go through complex synthesis steps and severe reactions. conditions, and even need to be produced with a unique grinding and dispersing technology. Therefore, the manufacturing cost of the aforementioned method is too high, so that it cannot be widely used.

SUMMARY OF THE INVENTION

In view of the technical defects of the above-mentioned water-repellent agent, the purpose of the present invention is to provide a method for preparing a fluorine-free water-repellent agent, because the fluorine-free water-repellent agent prepared by the method does not contain fluorine elements, and can meet the requirements of environmental protection and legal norms.

Another object of the present invention is to provide a method for preparing a fluorine-free water repellent, which is simple and cost-effective, and has potential for commercial implementation.

In order to achieve the foregoing object, the present invention provides a method for preparing a fluorine-free water repellent, comprising the following steps: step (a): adding a diol compound having a carboxylic acid group, a chain extender and a polyisocyanate to Carry out a polymerization reaction in an organic solvent to obtain a first mixture containing a polyurethane prepolymer; wherein, the chain extender is polyester diol, polyether diol, polysilicon diol or its combination; the molar ratio of the total hydroxyl groups of the diol compound with a carboxylic acid group and the chain extender to the total isocyanate groups of the polyisocyanate is 1:1.2 to 1:2; step (b): adding a The dendrimer is added to the first mixture, and the dendrimer is reacted with the polyurethane prepolymer in the first mixture to obtain a second mixture; and step (c): adding a fatty alcohol to the first mixture The end-capping reaction is carried out in the two mixtures to obtain a fluorine-free water repellent.

According to the present invention, because the total isocyanate groups of these reactants in step (a) are more than the total hydroxyl groups, the polyurethane prepolymer obtained after the addition polymerization of these reactants has at least one end is an isocyanate group; In step (b), the isocyanate group of the polyurethane prepolymer is reacted with the hydroxyl group of the dendritic polyol, so that the end of the polyurethane prepolymer has a dendritic structure. In short, the present invention obtains a side chain through addition polymerization of the isocyanate group of the polyisocyanate and the diol with a carboxylic acid group, a hydrophobic chain extender, a dendritic polyol and a hydroxyl group on the aliphatic alcohol. Polyurethane resins with carboxylic acid groups and hydrophobic segments on the main chain. On the one hand, because the carboxylic acid group is a hydrophilic group, the polyurethane resin can be uniformly dispersed in the water-based solution in subsequent applications to improve the coating properties; on the other hand, the polyurethane resin has a hydrophobic segment to make the polyurethane The resins are closely arranged, so that the surface to which the fluorine-free water repellent containing the polyurethane resin is coated has a low surface tension and thus has good water repellency.

According to the present invention, the reaction temperature of the step (a) and the step (b) is preferably 50°C to 85°C, more preferably 65°C. Controlling the reaction temperature of step (b) can help to regulate the reaction rate of the addition polymerization reaction and the molecular weight of the polyurethane prepolymer, and avoid problems such as violent exotherm or foaming caused by the reaction being too fast.

In some embodiments, the step (a) may include step (a1): reacting a diol compound having a carboxylic acid group with a polyisocyanate to obtain an intermediate product; and step (a2): making a chain extender Reacted with the intermediate product to obtain a first mixture containing the polyurethane prepolymer. This technical means can have the effect of improving the water solubility and stability of the fluorine-free water-repellent, thereby providing a method for preparing the fluorine-free water-repellent that can obtain stable quality.

Preferably, the reaction temperature of the step (a1) is 50°C to 65°C. More preferably, the reaction temperature of the step (a1) is 65°C. After the reaction of the diol compound with a carboxylic acid group and the polyisocyanate in step (a1) is complete, the temperature can be lowered by 5°C to 15°C, and after adding a chain extender, the temperature can reach step (a2) status.

Preferably, the reaction temperature of the step (a2) is 50°C to 85°C. More preferably, the reaction temperature of the step (a2) is 80°C.

According to the present invention, the polyisocyanate is hexamethylenediisocyanate (HDI), isophorone diisocyanate (5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane, IPDI), toluene Diisocyanate (toluene diisocyanate, TDI), methylene-bis (4-cyclohexylisocyanate, HMDI) or a combination thereof, but not limited thereto. In some embodiments, the polyisocyanate can be a combination of two polyisocyanates, such as isophorone diisocyanate and hexamethylene diisocyanate, isophorone diisocyanate and toluene diisocyanate, or toluene diisocyanate A combination of isocyanate and dicyclohexylmethane diisocyanate, etc. The molar ratio between the two different polyisocyanates is 1:4 to 4:1.

According to the present invention, the diol compound with a carboxylic acid group is 2,2'-dimethylol propionic acid (2,2'-bis(hydroxymethyl)propionic acid, DMPA), 2,2'-dihydroxy Methylbutyric acid (2,2'-bis(hydroxymethyl)butyric acid) or a combination thereof, but not limited thereto.

According to the present invention, the chain extender is polyester diol, polyether diol, polysilicon diol or a combination thereof. Due to the poor water solubility of polysilicon diols, organic solvents are needed to help disperse in subsequent applications; therefore, based on environmental protection considerations, the chain extender is more preferably polyester diol, polyether diol or a combination thereof In this case, accordingly, the fluorine-free water-repellent agent prepared by the method of the present invention does not substantially contain fluorine and silicon components, so the compatibility of the fluorine-free water-repellent agent is better and is not easy to be layered and preserved. longer term.

Preferably, the weight-average molecular weight of the polyester diol is 400 g/mol to 4000 g/mol; for example, the polyester diol may be poly[di(ethylene glycol) )adipate]), etc., but not limited to that. Preferably, the weight average molecular weight of the polyether glycol is 400g/mol to 4000g/mol; for example, the polyether glycol can be polyethylene glycol (poly(oxyethylene), PEG), polypropylene glycol (poly(propylene oxide), PPG) or poly(tetramethylene oxide), PTMEG, etc., but not limited thereto. The weight average molecular weight of the polysilicon glycol is 400 g/mol to 4000 g/mol; for example, the polysilicon glycol can be polydimethylsiloxane (PDMS) with 2 hydroxyl groups, but It is not limited to this.

According to the present invention, in order to obtain a polyurethane prepolymer having an isocyanate group at the end after the polymerization reaction of the diol compound having a carboxylic acid group, the chain extender and the polyisocyanate, Preferably, the molar ratio of the total hydroxyl groups of the diol compound with a carboxylic acid group and the chain extender to the isocyanate groups of the polyisocyanate is 1:1.2 to 1:1.7.

According to the present invention, the organic solvent is at least one selected from the group consisting of acetone, ethyl acetate and propylene glycol methyl ether.

According to the present invention, the weight-average molecular weight of the dendritic polyol in step (b) is 1500 g/mol to 12000 g/mol, and the number of hydroxyl groups contained in each mole of the dendritic polyol ranges from 10 to 30; The number of hydroxyl groups contained in moles of the dendrimer ranges from 15 to 25. For example, the dendritic polyol may be a dendritic polyester polyol, such as, but not limited to, commercially available from Boltorn Company under the trade names of P-500, P-501, W-3000, etc. Preferably, the dendritic polyol is P-500 or P-501.

According to the present invention, the molar ratio of the dendritic polyol to the polyurethane prepolymer is 1:8 to 1:20. Preferably, the molar ratio of the dendritic polyol to the polyurethane prepolymer is 1:10 to 1:12.

According to the present invention, the fatty alcohol in the step (c) is a straight chain fatty alcohol with 6 to 30 carbon atoms or a branched chain fatty alcohol with 4 to 30 carbon atoms. For example, the fatty alcohol may be 1-octan-1-ol (octan-1-ol), 1-nonanol (nonan-1-ol), 1-decanol (decan-1-ol), n-undecane Alcohol (undecanol), lauryl alcohol (dodecan-1-ol), n-tetradecanol (1-tetradecanol), cetyl alcohol (hexadecan-1-ol), stearyl alcohol (octadecan-1-ol), arachidyl alcohol (arachidylalcohol), n-docosanol (docosanol), n-octacosanol (1-octacosanol) or 1-triacontanol (1-triacontanol) and other straight chain fatty alcohols; the fatty alcohol can also be 2 -Methyl-1-propanol (isobutylalcohol), 2-ethyl-1-hexanol (2-ethyl-1-hexanol), isostearyl alcohol (isostearyl alcohol) and other branched fatty alcohols, but not limited thereto.

Due to the convenience of subsequent application, the solid content of the fluorine-free water repellent can be adjusted to 5wt% to 20wt%. By applying the fluorine-free water-repellent agent to the surface of the fabric to be treated, the fluorine-free water-repellent agent penetrates into the fibers of the fabric to improve the water-repellent effect of the fabric. In order to maintain the stability of the fluorine-free water-repellent, preferably, the pH of the fluorine-free water-repellent can be adjusted to be between 8 and 10.

The material of the fabric to be treated is not particularly limited. For example, natural fibers such as cotton, hemp, silk, and wool can be selected; semi-synthetic fibers such as rayon and acetate can also be selected; or nylon, polyester, and polypropylene can be selected. , polyacrylonitrile and other synthetic fibers, or a blended fiber of at least one natural fiber and at least one synthetic fiber.

According to the present invention, the fabric to be treated is treated with the fluorine-free water-repellent agent, such as dipping, spraying, coating and other processing methods. Preferably, after the fabric has been processed by the aforementioned processing methods, a drying step may be performed to remove the solvent.

In addition, without affecting the effect of the fluorine-free water-repellent agent of the present invention, the fluorine-free water-repellent agent can also be used with other auxiliary additives, such as surfactants, cross-linking agents, lubricants, etc. Wetting agent, antifouling agent or antibacterial agent, etc.

In addition, the present invention further provides a fluorine-free water-repellent prepared by the aforementioned method for preparing a fluorine-free water-repellent.

Description of drawings

1 is a schematic flow chart of the method for preparing a fluorine-free water repellent in Example 1.

Detailed ways

Hereinafter, the specific embodiments of the fluorine-free water repellent of the present invention will be illustrated by means of a number of examples, and those skilled in the art can easily understand the advantages and effects that the present invention can achieve through the contents of this specification, and are not inconsistent with Various modifications and changes can be made to implement or apply the contents of the present invention without departing from the spirit of the present invention. The raw materials used in Examples 1 to 3 are listed in Table 1 below.

Table 1

Example 1:

Please refer to FIG. 1 , which is a schematic flowchart of the method for preparing a fluorine-free water repellent in Example 1.

First, in step (a1), respectively get 33 grams of 2,2'-dimethylol propionic acid and 113 grams of isophorone diisocyanate and add them to the four-necked reactor containing 70 grams of ethyl acetate and 30 grams of acetone , and dropwise 0.1 g of dibutyltin dilaurate catalyst. Then, the above-mentioned reactants were uniformly mixed at 60° C. and reacted for 4 hours to obtain an intermediate product with a -NH(CO)O- functional group, and then the temperature was lowered to 50° C. Wherein, the molar ratio of the total hydroxyl groups of DMPA to the total isocyanate groups of IPDI is 1:2.06.

Subsequently, in step (a2), the temperature was raised to 80°C, and 200 grams of PTMEG-2000 as a chain extender was polymerized with the intermediate product and continued to stir until the reaction was completed, that is, PTMEG 2000 reacted with the intermediate product to A first mixture containing the isocyanate-terminated polyurethane prepolymer is obtained. Among them, the molar ratio of the total hydroxyl groups of PTMEG-2000 to the total isocyanate groups of IPDI is 1:5. Fourier transform infrared spectroscopy (FT-IR) can be used to determine whether the NCO group (transmittance of 2267 cm ⁻¹ ) has reacted to completion.

Next, in step (b), 20 grams of dendritic polyol P-500 was added to the first mixture, and the temperature of the first mixture was raised to 65°C and stirring was continued until the reaction was completed, that is, P-500 and polyamine The formate prepolymer is reacted to obtain a second mixture containing the dendrimer terminated polyurethane. Wherein, the molar ratio of P-500 and polyurethane prepolymer is 1:10.

Next, in step (c), 25 grams of 1-octadecanol was added to the second mixture, so that 1-octadecanol was subjected to an end-capping reaction to the polyurethane in the second mixture to obtain a polyurethane resin the capped product.

Finally, the fluorine-free water repellent was adjusted to a state with a solid content of 6 wt % and a pH of 9.

Example 2:

The method for preparing the fluorine-free water repellent in Example 2 is similar to the steps of the method in Example 1, except that the polyisocyanate is changed to a combination of hexamethylene diisocyanate and isophorone diisocyanate, and hexamethylene diisocyanate is used instead. The molar ratio of diisocyanate to isophorone diisocyanate is 3:7; in addition, the dendritic polyol uses a combination of P-500 and P-501, and the weight ratio of P-500 to P-501 is 1:3 .

Example 3:

The steps of the method for preparing the fluorine-free water repellent in Example 3 are similar to those of the method in Example 2, except that the molar ratio of hexamethylene diisocyanate and isophorone diisocyanate of polyisocyanate is changed to 7:3; In addition, the weight ratio of P-500 to P-501 of the dendrimer was 3:1.

Test Example: Characteristic Analysis of Fluorine-Free Water Repellents Obtained by the Preparation Methods of Examples 1 to 3

Test examples 1 to 3 and reference examples are applied to pure cotton fabrics as an example, and the fluorine-free water repellents and commercially available water repellents ( Trade name: R3, sold by DuPont), the water repellency and water pressure resistance time are the contact angles of water droplets, and the results are shown in Table 2 below.

Test examples 1 to 3 and reference examples listed in Table 2 are the fluorine-free water repellents and commercially available water repellents obtained by the preparation methods of Examples 1 to 3 in sequence as water repellents. It is used together with auxiliary additives such as organic alkali triethylamine; the pure cotton fabric used for testing is applied with these water-repellent agents with auxiliary additives to the pure cotton fabric through the dipping process; then, the aforementioned pure cotton fabric is heated at 160 ℃. After being treated for 90 seconds, the test examples 1 to 3 and the reference example were obtained after cooling to room temperature.

experiment method

1. Initial water repellency: graded using the spray test method of AATCC 22; according to the spray test grading table, grade 5 means the fabric is not wetted, grade 4 means the fabric is slightly wet, and grade 3 means the fabric is wet at the spray point. Wetting, a rating of 2 means the fabric near the spray point is partially wet, while a rating of 1 means the fabric is completely wet.

2. Washing 10 times, 20 times, and 40 times Water repellency: According to the spray test method of AATCC 22, test the water repellency after washing the pure cotton fabrics of Test Examples 1 to 3 and Reference Example 10 times, 20 times or 40 times respectively. water effect.

3. Water pressure resistance time: The time required for the deionized water dropped on the pure cotton fabrics of Test Examples 1 to 3 and Reference Example to be completely absorbed was judged with the naked eye.

4. Water drop contact angle: The contact angle when deionized water was dropped onto the surface of the pure cotton fabrics of Test Examples 1 to 3 and Reference Example was measured using a contact angle measuring instrument.

Table 2: Characteristic analysis results of Test Examples 1 to 3 and Reference Example.

As shown in Table 2, the contact angle of water droplets of the fluorine-free water-repellent obtained by the method for preparing the fluorine-free water-repellent provided by the present invention shows that the fluorine-free water-repellent of the present invention has high hydrophobicity; In the water pressure resistance test or the initial water repellency test, it can be found that the fluorine-free water repellent of the present invention has the same good effect as the commercial product; especially, the test example 2 and the test example 3 still have good water repellency even if they are washed many times , enough to see that the fluorine-free water repellent of the present invention also has washing resistance. To sum up, the method for preparing a fluorine-free water-repellent agent of the present invention is simple and cost-effective; and, the method for preparing a fluorine-free water-repellent agent and the prepared fluorine-free water-repellent agent of the present invention not only It can meet environmental protection demands and legal norms, and also has good water repellency, washability and water pressure resistance, so it has high market application value.

Claims (10)

1. a kind of method for preparing floride-free dryingagent, it includes following steps:

Step (a): by one tool carboxylic acid group diatomic alcohol compounds, a chain extender and a polyisocyanates in organic solvent into Row polymerization reaction, to obtain the first mixture containing polyamine urethane prepolymer；Wherein, the chain extender is polyester binary Alcohol, polyethers polybinary alcohol, poly- silicon dihydric alcohol or combinations thereof；The diatomic alcohol compounds and the chain extender of the tool carboxylic acid group are had The molar ratio of total isocyanate group of the total hydroxyl and the polyisocyanates that have is 1:1.2 to 1:2；

Step (b): a tree-shaped polyalcohol is added in first mixture, mixes the tree-shaped polyalcohol with described first Polyamine urethane prepolymer in object is reacted, to obtain the second mixture；And

Step (c): a fatty alcohol is added in second mixture and carries out end capping reaction, to obtain floride-free dryingagent.

2. the method for claim 1, wherein the reaction temperature of the step (a) and step (b) is 50 DEG C to 85 DEG C.

3. the method for claim 1, wherein the step (a) includes:

Step (a1): the diatomic alcohol compounds of the tool carboxylic acid group are reacted with the polyisocyanates, to obtain centre Product, wherein the reaction temperature of the step (a1) is 50 DEG C to 65 DEG C；And

Step (a2): reacting the chain extender with the intermediate product, to obtain containing described in polyamine urethane prepolymer First mixture, wherein the reaction temperature of the step (a2) is 50 DEG C to 85 DEG C.

4. the method for claim 1, wherein the polyisocyanates in the step (a) is that hexa-methylene two is different Cyanate, isophorone diisocyanate, toluene di-isocyanate(TDI), dicyclohexyl methyl hydride diisocyanate or combinations thereof.

5. the method for claim 1, wherein the diatomic alcohol compounds of the tool carboxylic acid group in the step (a) are 2,2'- dihydromethyl propionic acid.

6. the method for claim 1, wherein the weight average molecular weight of the chain extender is 400g/mol to 4000g/ mol。

7. the method for claim 1, wherein weight averaged molecular of the tree-shaped polyalcohol in the step (b) Amount is 1500g/mol to 12000g/mol, and hydroxyl value contained by every mole of tree-shaped polyalcohol is between 15 to 30.

8. the method for claim 1, wherein the fatty alcohol in the step (c) is the straight chain rouge of carbon number 6 to 30 The branched fatty alcohol of fat alcohol or carbon number 4 to 30.

9. the method for claim 1, wherein the solid content of the floride-free dryingagent is 5wt% to 20wt%.

10. a kind of free-floride dryingagent, is that the method as described in any one of claims 1 to 9 is prepared.