JPH0362458B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for preparing solid, supported catalysts consisting of perfluorocarbon polymers having pendant sulfonic acid groups. Solid perfluorocarbon polymers with pendant sulfonic acid groups can be used for the alkylation of aliphatic or aromatic hydrocarbons, the decomposition of organic hydroperoxides such as cumene hydroperoxide, the sulfonation or nitration of organic compounds, and It is a useful catalyst for the oxyalkylation of hydroxyl compounds. A serious drawback to the practical use of perfluorocarbon sulfonic acid catalysts has been their high cost. It is desirable to form catalysts into thin films as a means of reducing cost and improving effectiveness. This is because this allows for better control of the catalytic action, easier management of the heat of reaction and, in some cases, better selectivity. However, solid perfluorocarbon sulfonic acid catalysts with desirable molecular weights and equivalent weights are not thermoplastic, i.e., do not melt or soften upon heating;
Difficult to handle. Furthermore, perfluorocarbon polymeric sulfonic acids with equivalent weights greater than about 900 and molecular weights in the range of about 50,000 to 100,000 are poorly soluble in any solvent. Equivalent weight is about 900
Smaller polymers with molecular weights below 50,000 are soluble in organic solvents, ethanol, isopropanol, cyclohexanol, and mixtures of organic solvents and water. It is known in the polymer art that crosslinking polymer structures with free radicals and compounds with two functional groups can render low molecular weight polymers nearly insoluble. It is also known that perfluorocarbon polymers tend to reduce molecular weight and are not crosslinked by free radicals. Perfluorocarbon polymers with side chain sulfonic acid groups form salts with metal ions, and these are less soluble in most solvents than sulfonic acid polymers. However, sulfonate salts of perfluorocarbon polymers are not effective strong acid catalysts. There is no known method for precipitating a soluble perfluorosulfonic acid polymer from a solution onto a support and then insolubilizing the perfluorosulfonic acid polymer while retaining catalytic activity. The supported perfluorosulfonic acid catalyst of McClure et al. (U.S. Pat. No. 4,038,213
No.) is practically limited to use with anhydrous hydrocarbons, that is, without organic solvents. One aspect of this invention is an improved method for preparing supported catalysts comprising perfluorosulfonic acids. This embodiment is equivalent
1,000 or more, with a molecular weight of about 50,000 or more, converting the sulfonic acid groups to quaternary ammonium or phosphonium salts and depositing the polymer containing the quaternary ammonium and phosphonium salts on the carrier; It then consists of converting the ammonium and phosphonium salts into sulfonic acids. Another aspect of this invention is a new and improved method for preparing supported catalysts comprising perfluorosulfonic acids. In this method, in order to obtain the desired catalyst,
A perfluorocarbon polymer containing sulfonyl fluoride groups is first provided with the desired catalyst form or coated onto a substrate as an intermediate or precursor. The shaped polymer or coating is then converted to the perfluorocarbon sulfonic acid catalyst to the desired extent to obtain a composite structure consisting of a thin film of perfluorosulfonic acid resin, a thin film of an intermediate or precursor, and a support. do. When the intermediate polymer or precursor is molded as a thermoplastic resin, the molding is carried out by heating. Alternatively, the intermediate polymer or precursor is dissolved in a solvent and then evaporated and deposited to form a coating on the substrate. The sulfonyl fluoride membrane of the intermediate or precursor firmly adheres the perfluorosulfonic acid catalyst to the support and binds the perfluorosulfonyl fluoride, a low-equivalent and usually soluble perfluorinated material on the surface of the intermediate material. It serves to render the sulfonic acid molecule virtually insoluble. Insolubilization is probably due to entanglement of the polymer molecules and partial conversion of sulfonyl groups in the intermediate material or polymer molecules to sulfonic acid groups. Sulfonyl fluoride polymers are virtually insoluble in all solvents except fluorocarbons. The desired dimensions primarily maximize the surface area for reaction, reduce the cost of the catalyst, maximize the number of sulfonic groups on or near the surface of the polymer for efficient utilization of the catalyst, and occur upon solvation. Perfluorosulfonic acid catalysts are supported on solid supports for the purpose of modifying engineering and mechanical properties to obtain changes, fluid flow, heat removal, space-time yield reactions, crushing strength, etc. Desirable supported perfluorosulfonic acid catalysts are preferably prepared by melt deposition, preferably melt coextrusion, of a polymer of halogenated carbon or hydrocarbon onto a solid polymeric support to a thickness of 0.1 to 2.0 mil (0.0025 to 0.51 mm), preferably a 0.2-1.0 mil (0.0051-0.025 mm) coating, consisting of a perfluorosulfonyl fluoride polymer precursor film deposited as a coating with an equivalent weight of
It corresponds to a perfluorosulfonic acid polymer of 500 to 1300, preferably 900 to 1200. and the deposited perfluorosulfonyl fluoride polymer coating is 0.01 to 1.0 mil (0.00025 to 0.025 mm);
It is preferably converted to the corresponding perfluorosulfonic acid polymer to a depth of 0.05 to 0.5 mil (0.0013 to 0.013 mm). The preferred supported catalyst for this process differs significantly from the supported catalyst of McClure et al. (U.S. Pat. No. 4,038,213) in the following respects.
That is, the supported catalyst of the present invention is attached to a substantially insoluble intermediate material or precursor perfluorosulfonyl fluoride polymer;
The latter firmly adheres the catalyst membrane to the support and renders normally soluble perfluorosulfonic acid molecules of low equivalent weight and molecular weight virtually insoluble. The perfluorosulfonyl fluoride membrane also serves as a substantially impermeable barrier to minimize permeation of reaction and regeneration fluids to the substrate. Before this invention,
Practical methods for producing the desired supported perfluorosulfonic acid catalysts were not known. The desired supported perfluorocarbon sulfonic acid polymer catalyst is first prepared by using a perfluorocarbon polymer containing sulfonyl fluoride groups or quaternary ammonium or phosphonium sulfonic acid groups as an intermediate or precursor to form the desired catalyst. It can be obtained by molding it into a substrate or by coating it on a substrate. The shaped polymer or coating is then converted to the perfluorocarbon sulfonic acid catalyst to the desired extent. If the intermediate material is thermoplastic, shaping is carried out by heating. or by dissolving the intermediate polymer in a solvent and then evaporating and depositing it to form a coating on the substrate. The supported fluorocarbon polymer catalyst consists of a fluorocarbon polymer containing carboxylic or sulfonic acid groups supported on a substrate. Fluorocarbon polymers consist of copolymers of alpha-olefins (preferably low molecular weight ones such as tetrafluoroethylene, ethylene and propylene) and perfluorovinyl monomers having acid groups or precursor acid groups. A preferred catalyst is a perfluorocarbon copolymer of tetrafluoroethylene and perfluorovinyl ether having the following repeating structure. or

[Formula] or a mixture thereof In the formula, n is 0, 1 or 2, R ¹ is -F or perfluoroalkyl having 1 to 10 carbon atoms, Z is -O-CF ₂ -(CF ₂ ) _n -, −OCF ₂ CFY− or −
_OCFYCF2- , m is an integer of 1 to 9, and Y is -F or trifluoromethyl. Copolymer is 0.5~
May contain 50 mole % perfluorovinyl sulfonic acid. Preferably, the polymeric catalyst has an equivalent weight (polymer weight per sulfonic acid group, in grams) in the range 600 to 2500, most preferably in the range 900 to 1500. The average molecular weight of these copolymers is not exactly known, but it is approximately 50,000 ~
It is believed to be in the range of 100,000. Solid polymer with good mechanical strength is about 20000 or more,
It may have a molecular weight of 500,000 to 1,000,000. Mechanical properties such as tensile strength, tenacity, and bending life improve with increasing molecular weight. The molecular weight of the catalyst having the above structure is usually 1000~
500000, preferably greater than 10000,
The most desirable range is 50,000 to 100,000. According to US Pat. No. 4,038,213 and US Pat. No. 4,052,475, finely ground powders of certain fluorinated polymers having sulfonic acid groups can be dispersed in ethanol. However, the solid perfluorocarbon sulfonic acid polymers of the molecular weight and equivalent weight of this invention do not form true solutions. For example, using a polymer having a molecular weight of about 50,000 to 100,000 and an equivalent weight of about 700 to 1350, a solution of a sulfonyl fluoride precursor and a corresponding perfluorosulfonic acid polymer having an equivalent weight of up to about 900 is used. is a solution prepared by dissolving 3M's commercially available FC-75 fluorocarbon liquid (sulfonyl fluoride polymer) and 95% ethanol (perfluorosulfonic acid polymer), and the concentration of these solutions is 100%.
up to g/. A large equivalent weight (approximately 1050) of resin was refluxed with 95% ethanol, thereby dissolving approximately 65% of the resin. The remainder is insoluble in ethanol, representing fractionation of the resin and dissolution of the low molecular weight and low equivalent weight portions of the polymer. An equivalent weight of 1100 perfluorosulfonic acid polymer was refluxed with 95% ethanol, at which time approximately 10% of the resin was dissolved and the remainder was insoluble in the refluxed ethanol. equivalent weight 1200 and
Less than 2% of the 1350 perfluorosulfonic acid resin was insoluble in refluxing ethanol. Perfluorosulfonyl fluoride polymer precursors corresponding to high equivalent weight perfluorosulfonic acid resins are
Concentration of approximately 40-100 in FC-75 fluorocarbon liquid
A solution of g/g was made. Similarly, the desired perfluorocarbon sulfonic acid polymers made in accordance with this invention are substantially non-meltable and cannot be melted to form a true film that adheres to the carrier. (du Pont magazine “Jnnovation”)
See Vol. 4, No. 3, Spring 1973, pages 10-13, which describes the properties and preparation of several perfluorocarbon sulfonic acid polymers and their derivatives, DuPont's NAFION resins. ) Using this method, a supported sulfonic acid polymer having the following properties is obtained. It adheres strongly to the carrier,
A continuous membrane made from an inert polymeric structure or backbone with side chain active sulfonic acid groups, which is insoluble and does not leach from the carrier. The desired manufacturable intermediate polymers can be prepared in a variety of ways, but most commonly they are made from fluorocarbon vinyl ethers with the following molecular formula: MSO ₂ CFR ¹ CF ₂ O [CRYCF ₂ O] _o CF=CF ₂ () In the formula, R ¹ and Y are the same as in the formula and in, n is an integer of 1 to 3, M is fluorine, an amino group and - OM _e is a group selected from the group consisting of groups having the formula, where Me is a group selected from the group consisting of quaternary ammonium and phosphonium groups. Perfluorocarbon vinyl ethers and intermediate polymers derived therefrom are disclosed in U.S. Pat.
It is described in No. 3041317, No. 3282875, No. 3264053, and No. 3882093. The vinyl ether used to make the intermediate polymer can be as described in more detail in Connolly et al., U.S. Pat. No. 3,282,875.
Preferably, the polymerization is carried out using a perfluorinated free radical initiator in a perfluorocarbon solvent.
Since vinyl ethers are liquid under the reaction conditions, vinyl ethers can also be polymerized and copolymerized in large quantities without the use of solvents. Depending on the initiator used, polymerization temperatures range from -50° to +200°C
shall be. Pressure is not critical and is generally used to control the ratio of gaseous monomer to fluorocarbon vinyl ether. Suitable fluorocarbon solvents are known in the art and commonly use perfluoroheptane or perfluorodimethylcyclobutane. Similarly, perfluorinated initiators are known in the art;
Contains perfluoroperoxide and nitrogen fluoride. Vinyl ethers of the above structure can also be polymerized in aqueous solution using peroxide or redox initiators. The polymerization method used corresponds to the method established in the art of polymerizing tetrafluoroethylene in aqueous solution. Copolymerization of tetrafluoroethylene and/or perfluoro-α-olefin with vinyl ether is preferred. A particularly desirable copolymer made by polymerization of perfluoroethylene and a perfluorovinyl ether having sulfonyl fluoride groups will have a repeating structure as in the following example. where n is 1 or 2, or the ratio of x' and y' is about 2-50. These sulfonyl fluorides readily convert to alkali metals and quaternary ammonium sulfonates and quaternary phosphonium sulfonates. Potassium salts and sulfonic acid derivatives of this structure are commercially available under the trade name NAFION resin (EIdu Pont). Sulfonic acid catalysts derived from this structure exhibit the advantage of a high concentration of accessible acid groups in the solid phase. An intermediate polymer is produced and then shaped into the desired catalyst shape. Preferably, thermoplastic intermediate polymers are used because thermoplastics can be formed by heating and extruded or molded into desired shapes and onto a variety of substrates.
Alternatively, if the intermediate polymer is sufficiently soluble, it can be dissolved in a suitable solvent and deposited from solution onto the substrate. The solvent is removed before or after converting the intermediate to the active sulfonic acid form. One of the intermediates of supported perfluorocarbon sulfonic acid catalysts is the corresponding sulfonyl fluoride. The preparation of this sulfonyl fluoride is described in the above-mentioned patent. This material is thermoplastic. Therefore, it can be extruded into thin films, formed into products of various shapes, dip coated or fused onto a substrate. A preferred method for molding thermoplastic sulfonyl fluoride polymers onto a substrate is extrusion coating. In this case, the molten sulfonyl fluoride polymer is formed as a continuous thin film onto the surface of the substrate. If the substrate is a thermoplastic,
The sulfonyl fluoride polymer and the substrate are melt-molded by coextrusion, cut into appropriate sizes and shapes, and then the sulfonyl fluoride polymer is
It may be converted to perfluorosulfonic acid catalyst only to the extent desired. When performing partial conversion of the perfluorosulfonyl fluoride precursor or ammonium salt of the polymer to firmly adhere the sulfonic acid catalyst to the support, the unconverted sulfonyl fluoride polymer exhibits great strength, resistance to solvents and Provides chemically safe adhesion of sulfonic acid catalysts to solid supports. The idea of first depositing a precursor or intermediate and then partially converting the precursor or intermediate to a sulfonic acid is unique in the following respects. This is because the conversion of the sulfonyl fluoride polymer proceeds substantially stepwise into the interior of the polymer as the conversion agent penetrates the polymer structure, thereby forming a transition layer, which contains sulfonic acid groups. and a sulfonyl fluoride group, and is molecularly attached to the sulfonyl fluoride polymer and the perfluorosulfonic acid polymer through molecular entanglement and adhesion. This transition layer polymer is particularly useful for immobilizing low equivalent weight perfluorosulfonic acid polymer molecules. For economy in the preparation and use of supported catalysts, it is desirable to use as little of the expensive sulfonyl fluoride polymer precursor as possible;
It is particularly desirable for immobilizing sulfonic acid polymers on carriers. If a sulfonyl fluoride polymer is deposited onto a carrier that has groups that react with sulfonyl fluoride groups (e.g., amino and hydroxyl groups), it will react and chemically bond the perfluorocarbon polymer to the carrier; Easily minimize the amount of fluoride polymer used. It is also possible to melt-extrude the sulfonyl fluoride polymer onto the surface of a molten carrier. This welds the sulfonyl fluoride polymer to the carrier,
Expensive sulfonyl fluoride polymers are easily molecularly attached and the amount used is easily minimized. Other intermediates for fluorocarbon sulfonic acid catalysts are the corresponding quaternary ammonium or phosphonium sulfonates. Quaternary ammonium or phosphonium sulfonates are perfluorocarbon sulfonic acids or their alkali metal salts.

[expression] or

It is prepared by treating with the formula: where each R ² substituent is independently alkyl of 1 to 30 carbon atoms, alkylaryl of 7 to 36 carbon atoms, aralkyl of 7 to 36 carbon atoms, phenyl or naphthyl, and X is an inorganic anion, preferably a hydroxyl group or a halogen. The preparation of quaternary ammonium or phosphonium sulfonates is carried out by treating perfluorocarbon sulfonic acids or their alkali metal salts with compounds of formula or for 0.5 to 2 hours at 0 DEG to 100 DEG C. The reaction proceeds under atmospheric pressure, but higher or lower pressures may be used if desired. Sulfonate salts made by this method can be purified by washing with water to remove residual by-products. These sulfonates are thermoplastic. They can therefore be shaped as described above for the sulfonyl fluorides. They are also soluble in polar, aprotic solvents such as dimethylformamide and dimethylsulfoxide. Solutions of such sulfonate salts can therefore be used to coat desired substrates using well known techniques for coating with polymer solutions. Particularly desirable quaternary ammonium and phosphonium sulfonates include tetrabutylammonium hydroxide, benzyltrimethylammonium chloride, hexadecyltrimethylammonium chloride,
and tetrabutylphosphonium iodide. The present invention uses perfluorocarbon polymers having side chain sulfonic acid groups. Supported catalysts can be modified by adding metals, metal oxides, metal ions, metal chelates, and other compounds. These are usually homogeneous solvents. The substrate used to support the catalyst thin film is
Any of a number of materials suitable for use as a catalyst support may be used. Any form of metal, Teflon fiber, asbestos, glass (spirals, beads, cloth, etc.), e.g. screens or sheets
others. Furthermore, the perfluorocarbon sulfonyl fluoride becomes a coating layer, and the desired thickness of the surface layer of the sulfonyl fluoride is converted into an acid catalyst. In one preferred embodiment, the supporting surface is a fluorocarbon such as a sulfonyl fluoride polymer (which can be an intermediate used in forming the catalyst structure), polyethylene, polypropylene, polyamide, polyester, or tetrafluoroethylene polymer. It is a solid polymer that does not have a catalytic effect like a polymer. In other preferred embodiments, the carrier is a metal;
Or it is an inorganic solid substrate such as ceramic. Preferably, the materials are those commonly used in process equipment. Examples of metal carriers include monel, nickel, titanium, copper, brass, stainless steel (eg Hasteloy), tantalum, zirconium, and the like. Particularly suitable is a thin film of solid polymeric acid catalyst supported on an impermeable heat exchanger member, which can be constructed from heat exchanger tubes, plates, etc. made of a heat conductive metal. They are particularly suitable for carrying out processes in which exothermic reactions are controlled. An example is our co-pending U.S. Application No. 132149.
No./1980 (this is now abandoned U.S. Application No.
No. 970,474/1978, a continuation-in-part application), as described and claimed in Hydroperoxide Decomposition. The heat exchanger member carrying the catalyst is substantially impermeable and provides a support for the catalyst film under conditions of heat exchange with the coolant or heat transfer fluid. Catalyst films are typically very thin, ranging from molecular thickness to 10 mils (0.25 mm), and most preferably less than 2 mils (0.051 mm). The intermediate is formed into the desired form, properly adhered to the carrier, and then converted to the active sulfonic acid form. The amount of intermediate to be converted by calculating the number of equivalents in the region to be converted (obtained from the density and equivalent weight of the intermediate) and then reacting with a suitable substance to form the sulfonic acid group. can be easily controlled. The rate of formation of sulfonic acid groups is a function of time, temperature and the concentration of the substance used to convert the intermediate to sulfonic acid. Since both of these variables are easily controllable, conversion of the desired amount of intermediate can be achieved with great precision. The materials necessary to convert the intermediate to the sulfonic acid form will be readily apparent to those skilled in the art.
And this will depend on the type of intermediate.
For example, sulfonyl fluoride is converted to the acid form as follows. First, treatment with an aqueous solution of an alkali metal hydroxide to produce the potassium salt, preferably in the presence of an additional solvent such as dimethyl sulfoxide or hexamethylphosphoramide, followed by treatment with an aqueous solution of an alkali metal hydroxide such as hydrochloric acid and nitric acid. Treatment at an intensity with a PKa less than zero converts the potassium salt to the sulfonic acid form. Quaternary ammonium and phosphonium sulfonates are converted to the sulfonic acid form in a similar manner. Therefore, sulfonic acids may be obtained by ionic conversion. For example, quaternary ammonium and phosphonium sulfonates can be treated with strong acids such as 20% nitric acid. Sometimes it may be desirable to first convert the ammonium or phosphonium sulfonate to the alkali metal salt by such means as treatment with an aqueous sodium chloride solution and then replace the sodium by heat treatment. As previously mentioned, in a preferred embodiment, a thermoplastic intermediate solid polymer of perfluorocarbon vinyl ether having sulfonyl fluoride groups is prepared and the intermediate polymer is applied in the form of a desired catalyst, such as a thin film supported on a metal surface. By shaping the combination and then converting at least a portion of the sulfonyl fluoride groups to the sulfonic acid form, a supported perfluorocarbon sulfonic acid catalyst in the desired form is obtained. This results in a non-plastic catalyst that is firmly adhered to the carrier and has an activity that cannot be extracted from the carrier. The perfluorocarbon sulfonic acid polymer catalyst can thus be formed as a tightly adhered insoluble thin film on the support, preferably as a continuous layer. Such forms of catalyst are extremely effective. The following examples are included for illustrative purposes only and should not be construed as limiting the scope of the invention described herein. EXAMPLE 1 A polymer in the form of a sulfonyl fluoride represented by the formula is formed as a thin film on the inner wall of a tube having an inner diameter of 0.024 inch (0.61 mm), an outer diameter of 0.036 inch (0.91 mm), and a length of 18 feet (5.5 m), Immersed in water at 50°C.
(The polymer was prepared using tetrafluoroethylene perfluorovinyl ether with a sulfonyl fluoride ratio of about 3 and an equivalent weight of 1200. The molecular weight is not precisely known but is believed to be between 50,000 and 100,000. ) A mixture of 10% potassium hydroxide, 35% dimethyl sulfoxide, and 55% water.
This was allowed to flow through the tube for 45 minutes. The mixture may provide excess base to expose the interior surface of the sulfonyl fluoride to aging conditions during this time. A sufficient amount of 2 molar hydrochloric acid was then flushed into the tube to displace the potassium ions. This process converted the inner wall of the tube to a thickness of 0.0011 to 0.0015 inches (0.028 to 0.038 mm) to the sulfonic acid form. Example 2 A 1 inch (25 mm) outside diameter stainless steel inner tube with a 0.02 inch (0.51 mm) layer on the outside and a 0.05 inch radial spacing in between. (1.3
A coaxial tube arrangement is used with a metal outer tube or casing of a diameter that creates an annular space of mm). An amount of reactant sufficient to fill the annular space is allowed to flow turbulently in contact with the surface of the active catalyst. At the same time, a coolant such as water or other thermally conductive liquid is used in sufficient quantity to remove the heat of reaction and maintain the temperature of the mixture of reactants and reaction products at a desired value, e.g. 40°C. The inside of the inner tube was flushed. Another example of a thin film of catalyst formed on a heat exchange member in a suitable heat exchanger with a suitable amount of coolant flowing on the opposite side of the heat exchanger member is described below. A carboxylic acid group catalyst of the "Nafion" type is prepared as a membrane on a steel heat exchange member as follows. A copolymer of tetrafluoroethylene and perfluorovinyl ether methyl ester (in a molar ratio that provides approximately 10-30% ester in the copolymer) is formed as a thin film onto the heat exchanger member. Cover. The surface is then treated with NaOH to saponify the ester groups, then, after washing, treated with dilute acid to form carboxylic acid groups. (For details on the generation of carboxylic acid groups, see Hiroshi Ukihashi's "Chemtech" 1980.
February, pp. 118-120. ) Other types of thin films comprising active solid perfluorocarbon polymers having pendant acid groups supported on the surface of suitable substrates can be readily devised by those skilled in the art with reference to this specification. The supported fluorosulfonic acid catalyst is prepared by coextrusion of a fluorosulfonyl fluoride precursor resin and a polyethylene resin. Coextrusion can be accomplished by conventional techniques, in which the fluorosulfonyl fluoride resin is extruded from a die simultaneously with the melt extrusion of the polyethylene resin. The polyethylene resin is then formed into fibers or wires by extrusion and directed onto which is coated a thin film of molten fluorosulfonyl fluoride resin. The extruded composite is quenched and
By cutting to the desired size, the fluorosulfonyl fluoride membrane is converted to the fluorosulfonic acid catalyst to the desired depth. A typical supported catalyst is a polyethylene resin and a fluorosulfonyl fluoride resin coextruded at a temperature of about 250 to 350°C to coat polyethylene fibers about 5 mils (0.13 mm) in diameter. and a membrane of sulfonyl fluoride resin approximately 0.5 mil (0.013 mm) thick. The extruded compact is cut into lengths of approximately 0.25 inches (6.4 mm) and the fluorosulfonyl fluoride film is converted to a fluorosulfonic acid resin to a depth of approximately 0.35 mils (0.0088 mm). As another example, a supported fluorosulfonic acid catalyst is prepared by melt depositing a coating of sulfonyl fluoride resin onto a nominal 0.5 inch (13 mm) Monel metal tube for a heat exchanger. Melt deposition can be carried out using conventional melt extrusion equipment, in which a metal tube is passed through a die and the molten fluorosulfonyl fluoride polymer is pressed into the tube. The coated metal tubes can be formed into tube banks using conventional techniques for uncoated tubes, and the tube examples can be assembled into a shell and tube heat exchanger. The sulfonyl fluoride coating can be converted to sulfonic acid to the desired depth. Typically, the fluorosulfonyl fluoride resin is extruded at a temperature of about 250-350°C to form a continuous coating on the exterior surface of the metal tube. The film thickness of the fluorosulfonyl fluoride resin is about 0.5 mil (0.013 mm), and the film can be converted to a sulfonic acid catalyst to a depth of about 0.25 mil (0.0063 mm).

Claims (1)

[Scope of Claims] 1. An impermeable solid substrate, which is coated with a sulfonyl fluoride group convertible to a sulfonic acid group, or a quaternary ammonium salt of sulfonic acid or a side chain of a sulfonium base. consisting essentially of a 0.1 to 10 mil (0.0025 to 0.25 mm) thick film of a fusible solid perfluorocarbon polymer, the polymer film having a surface layer having side chains of sulfonic acid groups that is insoluble and infusible. a solid perfluorocarbon polymer, the unconverted portion of the polymer film adhering said acidic polymer to a substrate. 2 The thin film has a thickness of 0.1 to 2 mils (0.0025 to
0.051 mm) and adapted to contact the reactant and for the substrate to contact a coolant on the opposite side of the thin film coating to remove the heat of reaction, A solid polymeric acid catalyst composite according to claim 1, adapted to carry out strongly exothermic reactions under controlled conditions. 3. The thin film has a molecular weight of 50,000 to 100,000.
A catalyst according to claim 1. 4. The solid polymeric acid catalyst according to claim 1, wherein the supporting substrate is a solid polymer having no catalytic action. 5. The solid polymeric acid catalyst according to claim 1, wherein the supporting substrate is a metal or inorganic solid substrate. 6. The solid polymeric acid catalyst according to claim 1, wherein the supporting substrate is a heat conductive metal. 7 A method for preparing a supported infusible and substantially insoluble catalyst comprising a perfluorocarbon polymer having a side chain sulfonic acid group, the method comprising: first a side chain sulfonyl group convertible to a sulfonic acid group; Thickness of intermediate perfluorocarbon polymer with fluoride groups 0.1 to 10 mils (0.0025 to 0.25
secondly, converting only the surface layer of the side groups of the intermediate in the coating into sulfonic acid groups, thereby converting the unconverted polymer into sulfonic acid groups; obtaining a composite comprising the infusible and substantially insoluble acid polymer catalyst adhered to the supporting substrate. 8. The method of claim 7, wherein the coating is formed by melt deposition of a fusible perfluorocarbon polymer having pendant sulfonyl fluoride groups. 9. The method of claim 7, wherein the perfluorosulfonyl fluoride polymer is extruded onto the substrate to form a coating having a thickness of 0.1 to 2.0 mils (0.0025 to 0.051 mm). 10. The manufacturing method according to claim 7, wherein the intermediate polymer is formed by extruding or coating it as a thin film on a metal surface. 11. A method for preparing a supported infusible and substantially insoluble catalyst comprising a perfluorocarbon polymer having side chain sulfonic acid groups, comprising: first an equivalent weight of at least 1000 and a molecular weight of at least 25000; The intermediate perfluorocarbon polymer having a quaternary ammonium or phosphonium salt of a side chain sulfonic acid has a thickness of 0.1 to 10 mils (0.0025 to 0.25 mm), corresponding to a perfluorocarbon polymer having a side chain sulfonic acid group. coating a solid substrate with a thin film; second, converting some of the side chain sulfonate salts in the coating to sulfonic acid groups, thereby converting the quaternary ammonium or phosphonium salt of the sulfonic acid to an unconverted intermediate polymer having
A method of making a solid polymeric acid catalyst composite comprising the step of providing a substantially insoluble composite of said sulfonic acid polymeric catalyst adhered to said supporting substrate. 12. The method of claim 11, wherein the coating is formed by melt deposition of a fusible perfluorocarbon polymer having a quaternary ammonium or phosphonium salt of a pendant sulfonic acid.