JPS6358816B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for producing acrylic esters. More specifically, the present invention relates to a method for producing an acrylic ester as a monomer that provides a polymer that can effectively act as a water and oil repellent. [Prior Art] Water and oil repellents made of polymers having perfluoroalkyl groups in their side chains have been known for a long time. A water and oil repellent agent comprising a diacetone acrylamide compound or a -CH ₂ OR derivative thereof and, if necessary, a copolymer of vinyl chloride, was also published in Japanese Patent Publication No. 1973-
No. 9416 discloses that a methacrylic acid ester having a perfluoroalkyl group at the end of the ester group is
A water and oil repellent agent comprising a copolymer of ethylhexyl methacrylate, a (meth)acrylic acid ester having a hydroxyl group in the ester group, and N-methylolacrylamide is described. These copolymers having perfluoroalkyl groups in their side chains have the specificity of perfluoroalkyl groups, that is, they lack affinity with substances that do not have perfluoroalkyl groups, and they have extremely low surface tension. It is used in water and oil repellents as a copolymer that has improved other required physical properties by copolymerizing it with other comonomers. For example, in the case of the copolymer described in Japanese Patent Publication No. 47-9416, perfluoroalkyl group-containing methacrylic ester provides water and oil repellency, 2-ethylhexyl methacrylate provides water repellency and flexibility, and hydroxyl group provides water and oil repellency. The (meth)acrylic acid ester and N-methylolacrylamide contained in the copolymer are copolymerized in order to impart adhesion to fibers and the like to the copolymer. Generally, water and oil repellents are used as treatment agents for fibers, etc., but homopolymers with perfluoroalkyl groups in their side chains are crystalline because the perfluoroalkyl groups are rigid and long chains. ,
When such a crystalline polymer is applied to fibers, etc., the fibers etc. become stiff, resulting in a loss of texture. Also, since it is a crystalline polymer, when applied to colored fabrics, etc.
In practice, it is not used in the form of a homopolymer because the dried film of the water and oil repellent is not transparent and spoils the color of fabrics. In order to avoid these drawbacks that occur when a homopolymer having a perfluoroalkyl group in the side chain is used for a water and oil repellent, copolymerization with other comonomers as described in the above-mentioned patent publications is necessary. However, even if the modification is successful, the proportion of perfluoroalkyl group-containing monomer components in the copolymer decreases, resulting in In many cases, water and oil repellency, which is the most desired property, is impaired, and to date, there have been almost no water and oil repellents that can satisfy both water and oil repellency and other physical properties at the same time. This is the reality. [Problems to be Solved by the Invention] The present inventor has devised a polymer that does not take the form of a copolymer that impairs water and oil repellency, and that reduces the rigidity and crystallinity seen in homopolymers. As a result of various studies, we found that a polymer having a poly(perfluoroalkylene glycol) group in its side chain, even if it is a homopolymer, can be applied to fabric without impairing its texture or color. Moreover, it has been found that it exhibits sufficient water and oil repellency. Also,
This polymer can be in the form of a copolymer within a range that does not impair its water and oil repellency; in this case, the washing resistance will be even better. An object of the present invention is to provide a method for producing an acrylic acid ester as a monomer that provides a polymer that can effectively act as a water and oil repellent. [Means for Solving the Problems] Therefore, the present invention relates to a method for producing an acrylic ester, and the acrylic ester produced by the method of the present invention has the general formula (Here, R is a divalent organic bonding group, R' is a hydrogen atom or a methyl group, Rf is a perfluoro lower alkyl group, and n is 0 or 1 to 10
is an integer). Such acrylic esters include: When , the following compounds can be mentioned. Synthesis of acrylic acid ester is carried out by converting the acid fluoride of poly(hexafluoropropylene glycol) obtained by polymerizing hexafluoropropylene oxide into the corresponding carboxylic acid, as exemplified in the reference example below. and glycidyl acrylate or glycidyl methacrylate. The acid fluoride that is the starting material for the synthesis reaction is obtained by polymerizing hexafluoropropylene oxide. When hexafluoropropylene oxide is homopolymerized, an acid fluoride represented by the above formula is obtained, but COF ₂ ,
When CF ₃ COF, C ₂ F ₅ COF, C ₃ F ₇ COF, etc. are used and a polymerization reaction is carried out in the presence of these compounds, polymers containing various perfluoro-lower alkyl groups are produced as shown in the following examples. An acid fluoride is obtained which, upon subsequent hydrolysis, yields the corresponding carboxylic acid. The acid fluoride obtained by polymerizing hexafluoropropylene is a mixture of substances having various numbers of n, and they can be obtained by distillation from n=0 to 1,
It can be separated into fractions 2-3 and 4-6. In addition, by changing the polymerization conditions, it is possible to obtain an acid fluoride having a certain desired number of n. For example, when trying to obtain an acid fluoride with a small number of n, the type of solvent This can be achieved by selecting the desired amount or by increasing the reaction temperature. Specifically, when 100 g of hexafluoropropylene oxide is polymerized at 0°C in the presence of 5 g of cesium fluoride catalyst and 20 ml of acetotrile, the resulting acid fluoride is a mixture of n = 0 to 4; It can be separated into the following fractions by distillation. n=0 5.7g n=1 15.4g n=2 47.3g n=3 18.2g n=4 10.6g The conversion reaction from the acid fluoride to the corresponding carboxylic acid is carried out according to a known method. Below, methods for synthesizing acrylic esters using conversion compounds will be described in sequence. The addition reaction is carried out in the presence of hydroquinone with a catalyst such as triethylamine and trifluoroethane, difluorotetrachloroethane, trifluorotrichloroethane, tetrafluorodibromoethane, tetrafluorodiiodoethane, tetrafluorobromoidoethane, pentafluorobromoethane. , fluorine-containing compound solvents such as pentafluoroiodoethane, trifluorotoluene, and hexafluoroxylene, and ether solvents with a boiling point of 100°C or higher that are compatible with these, such as dioxane,
The reaction is carried out using a mixed solvent with tetrahydrofuran, diglyme, triglyme, tetraglyme, etc., and the reaction does not proceed with these solvents alone. In addition, in this addition reaction, the following by-products may be obtained at the same time. For the polymerization of acrylic esters, general radical polymerization techniques can be applied as is. That is,
In the case of emulsion polymerization, for example, octadecyldimethylamine hydrochloride or the like is used as an emulsifier, and azobisisobutyramidine hydrochloride or the like is used as a polymerization initiator. In the case of solution polymerization, aromatic compounds, ketones, alcohols, A polymerization reaction is carried out using a halogenated hydrocarbon or the like as a polymerization solvent, and azobisisobutyronitrile, peroxide, or the like as a polymerization initiator. The homopolymer of acrylic acid ester itself can be used as a water and oil repellent with desired properties, but it can also be used as a water and oil repellent in the form of a copolymer with other vinyl compounds. Various other vinyl compounds that can be used as comonomers include the following. (1) Vinyl compounds having a hydrocarbon group having 4 or more carbon atoms, such as butyl acrylate, butyl methacrylate, octyl acrylate, octyl methacrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, benzyl acrylate, etc.; halogen-containing vinyl compounds, such as vinyl chloride, Vinylidene chloride, 2-
Chlorethyl vinyl ether, vinyl bromide, vinyl fluoride, vinylidene fluoride, etc.; diene compounds, such as chloroprene, isoprene, butadiene, etc.: These vinyl compounds or diene compounds are about 99% by weight or less, preferably about 90% by weight or less More preferably, it is used in a proportion of about 75% by weight or less, and contributes to improving the flexibility of the polymer and the solubility in halogenated solvents. (2) Vinyl compounds having active groups such as hydroxyl group, amide group, amino group, carboxyl group, phosphoric acid group, sulfonic acid group, etc., such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, N-methylolacrylamide, acrylamide , methacrylamide, 4
-Aminostyrene, acrylic acid, methacrylic acid, maleic acid, 2-acryloyloxyethyl acid phosphate, 4-sulfonylstyrene, etc.: These vinyl compounds are present in an amount of about 0.01 to 10% by weight, preferably about 0.05 to 5% by weight. %, more preferably from about 0.1 to 2% by weight, and the presence of active groups in the vinyl compound increases the polymeric fiber,
Strengthens adhesion to paper, leather, etc. (3) Vinyl compounds having a lower perfluoroalkyl group, such as 2,2,2-trifluoroethyl acrylate, 1,1,1,3,3,3-hexafluoro-2-propyl acrylate: These vinyl compounds , about 10-90% by weight,
Preferably about 20-80% by weight, more preferably about
Used in proportions of 30 to 60% by weight, they further slightly improve the water and oil repellency and flexibility, respectively, of the polymer. Water and oil repellents are prepared in the form of diluted aqueous solutions of polymers synthesized in an aqueous medium by emulsion polymerization or suspension polymerization, or by bulk polymerization. Alternatively, when the solution polymerization method is used, it is carried out in the form of a diluted solution of the organic solvent. Water- and oil-repellent treatment uses water- and oil-repellent agents prepared in this way to treat various fibers such as cotton, wool, silk, polyester, polyamide, and regenerated cellulose, or woven fabrics made from blends thereof, pulp products, leather, etc. This is done on the objects to be processed. Next, the present invention will be described with reference to examples. Reference example: By the method described in Japanese Patent Publication No. 40-10061,
The following reaction was performed. The acid fluoride was hydrolyzed in the absence of a catalyst and converted to the corresponding carboxylic acid. Example 100g of carboxylic acid (n=1) obtained in Reference Example
(0.201 mol), hydroquinone 1.0 g, triethylamine 2.5 g, trifluorotrichloroethane
100 ml and dioxane, and to this mixture 25.6 g (0.200 mol) of glycidyl acrylate.
drip. After reacting for 4 hours under reflux conditions,
The reaction solution is washed with water and the organic phase is separated. After dehydration, this phase is distilled and concentrated. 117 g (yield 93.2%) of concentrate was obtained. Based on the results of NMR spectrum, infrared absorption spectrum measurements, and elemental analysis of this concentrate, this concentrate is considered to be a mixture of compounds represented by the following two formulas. (Main product) (by-product) F-NMR (CF ₃ COOH external standard; same below): 6
~8ppm (CF ₃ , CF ₂ ) 55ppm (CF ₃ CF ₂ CF ₂ O) 69.5ppm (CF) H-NMR (TMS internal standard; same below): 5.5 ~
5.6ppm (acrylic group) Infrared absorption spectrum 3450cm ^-1 (hydroxyl group) 1780cm ^-1 (ester group

[Formula] 1720cm ^-1 (ester group CH ₂ =CHCOOCH ₂ -) Elemental analysis Calculated value C: 28.84%, H: 1.44%, F: 51.76% Actual value C: 27.15%, H: 0.95%, F: 51.58% Comparative Example In the example, 200 ml of dioxane alone was used instead of the trifluorotrichloroethane-dioxane mixed solvent, and when the reaction was carried out under reflux conditions for 4 hours, the contents gelled. The solution portion was decanted, and the gel-like organic matter was repeated with a total of 1 dioxane and combined with the extracted material, and then the dioxane was distilled off, but a polymeric residue remained.
Only 2.1g was obtained. A polymerization reaction using the acrylic ester thus obtained and a water and oil repellency test using the polymer as the polymerization reaction product were conducted as follows. Application example 220 parts of deionized water heated to 50-60°C (by weight,
15 parts of trimethyloctadecyl ammonium chloride was dissolved in 15 parts of trimethyloctadecyl ammonium chloride (the same applies hereinafter), and a compound represented by the following formula obtained in the same manner as in the above example was added. 100 parts, 2-hydroxyethyl acrylate 0.5
1 part, 0.5 part of N-methylol acrylamide and 100 parts of acetone, and thoroughly mixed with a colloid mill and stirred. After the inside of the reactor is sufficiently purged with nitrogen gas, 0.05 part of azodiisobutyramidine hydrochloride as a radical polymerization initiator is added thereto under reflux conditions. After 4 hours, the copolymerization reaction is terminated. A milky white aqueous latex was obtained with a solid content concentration of 23.2% by weight, indicating that the polymerization reaction had proceeded almost completely. Dilute the obtained aqueous latex with water to approximately 0.5
The solid content concentration is adjusted to % by weight, and a cotton cloth is dipped therein. After soaking for about 5 minutes, the cloth was taken out, water was sufficiently squeezed out using a dehydration roll, and then dried at 175° C. for 5 minutes. The cotton fabric treated with the copolymer in this way was tested for water repellency as follows.
An oil repellency test, a washability test and a stiffness test were conducted. [Water repellency test] A drop of water was dropped onto the treated cotton cloth, and the condition was observed after 5 minutes had passed.

[Table] [Oil repellency test] Drop one drop of the test liquid (mixed liquid at a specific ratio shown in the table below) onto the treated cotton cloth and observe the condition after 5 minutes have elapsed. If the applied test solution is retained on the cloth, test with a test solution with a higher n-heptane content, and conversely, if it is not retained on the cloth, use a test solution with an even higher n-heptane content. test. Then, using the test liquid that can be retained on the cloth at its limit, the oil repellency is evaluated based on the oil repellency evaluation shown in the table below. In the oil repellency evaluation, the case where 100% Nudyol is retained is 50, and the case where 100% Nudyol is not retained is 0.

【table】

[Table] [Washability test] The treated fabric was soaked in water containing 0.1% by weight of neutral chip soap and 0.05% by weight of soda lime.
Stir at 60-80°C for 40 minutes, then press for 30 seconds. After repeating this operation three times, water and oil repellency was evaluated. [Rigidity Test] Based on the JIS L-1096B method, the stiffness is measured, and then the flexibility is calculated according to the following formula. The closer the value of this flexibility is to 1, the closer it is to untreated, and the smaller the value, the harder it is. Flexibility = Bending resistance of untreated fabric/Bending resistance of treated fabric Comparative Application Example In the above application example, the same amount of the compound represented by the following formula was used in place of the compound '. Many precipitates were observed during the polymerization reaction. CH ₂ =CHCOOCH ₂ CH ₂ C ₈ F ₁₇ [Compound] The results obtained in the above application examples and comparative application examples are shown in the following table.

【table】

Claims (1)

[Claims] 1. General formula (Here, Rf is a perfluoro lower alkyl group, and n is an integer of 0 or 1 to 10.) A carboxylic acid represented by A general formula characterized by an addition reaction in the presence of a mixed solvent with an ether solvent having a boiling point of 100°C or higher. (Here, R' is a hydrogen atom or a methyl group,
Rf and n are as defined above) or a method for producing an acrylic ester containing the same as a main component.