JPH03275138A - Photoreactor - Google Patents

Abstract

PURPOSE:To obtain a photoreactor having a low refractive index and high light transmissivity by forming a layer of a polymer having a fluorine-contg. alicyclic structure on one side of a transparent material brought into contact with a reactive stock soln.. CONSTITUTION:A photoreactor is made of transparent material such as glass or quartz and a layer of a polymer having a fluorine-contg. alicyclic structure obtd. by polymerizing a soln. of a fluorinecontg. monomer such as perfluoroallyl vinyl ether with a polymn. initiator is formed on one side of the transparent material brought into contact with a reactive stock soln. Since the polymer has high transparency, a low refractive index, superior moldability and satisfactory strength, the transparent material of the photoreactor ensures superior transparency, hydrofluoric acid resistance, moldability, adhesive property and strength.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a photoreactor using a polymer having a fluorine-containing aliphatic ring structure as a light transmitting material.

[Prior Art] In many cases, when a chemical reaction is carried out, the reaction proceeds more efficiently by using light energy. In such a case, a reactor partially or entirely made of a light-transmitting material is preferably used.

The material used for the light transmitting material is glass, quartz, etc. depending on the wavelength used. However, in the above materials, the presence of hydrofluoric acid corrodes the surface and reduces the light transmittance of the light transmitting material, making it unusable.

Single crystal sapphire can be used as a material that is not corroded by hydrofluoric acid, but it is very expensive and difficult to mold, making it impractical for industrial use.

On the other hand, Utility Model Publication No. 1-33157 describes a tetrafluoroethylene/hexafluoropropylene copolymer, a tetrafluoroethylene/hexafluoropropylene copolymer that can be melt-molded as a light-transmitting material,
Disclosed are methods using ethylene copolymers, tetrafluoroethylene/perfluoropropyl vinyl, ether copolymers, vinylidene fluoride/hexafluoroisobutylene copolymers, chlorotrifluoroethylene polymers, or vinylidene fluoride polymers. . However, the above-mentioned fluoroolefin polymer has low light transmittance at a thickness that should be selected with strength in mind, and the film-like fluoroolefin polymer is not suitable for use with materials such as quartz plate with good light transmittance. The method of reinforcing with 1-2- has poor adhesion between the fluoroolefin polymer and other materials, and is not durable for long-term use.

[Problems to be Solved by the Invention] The present invention eliminates the drawbacks of conventional materials as described above, and provides a light-transmitting material with excellent transparency, hydrofluoric acid resistance, moldability, adhesiveness, and strength. The object of the present invention is to provide a new photoreactor having the following characteristics.

[Means for Solving the Problems] Based on the recognition of the above-mentioned problems, the present inventors have conducted intensive studies and found that a polymer having a fluorine-containing alicyclic structure has high transparency and a low refractive index. It has been newly discovered that this material is extremely advantageous as a material that provides a light-transmitting material with excellent moldability and sufficient strength.

Thus, the present invention has been completed based on the above findings, and provides a novel photoreactor characterized by using a polymer having a fluorine-containing aliphatic ring structure.

The photoreactor of the present invention may be of any shape, such as an external irradiation type reactor or an internal irradiation type reactor.

In the present invention, the polymer having a fluorine-containing aliphatic ring structure may be exemplified over a wide range of examples, including those that are conventionally known or well-known. Therefore, in the present invention, a fluorine-containing polymer having the above-mentioned specific ring structure in the main chain is preferably employed.

Examples include those having a ring structure as shown in the general formula. Among these, polymers having the following ring structures are representative.

However, the content of the present invention is not limited to these only.

(1) CF2=CF-0-CF2CF2-0-CF2
CF2↓ Radical polymerization (2) CF2=CF-CF2-CFCI-CF2-C
F-CF3I Radical Polymerization There are two methods for producing these polymers. However, it is not limited to these manufacturing methods.

(USP 3202643, etc.) (3) Ch=CF-0-Ch-CF2CF2 Radical polymerization 1, cyclopolymerization 5-6-2, cyclic monomer-based method (USP 3978030) In the above, perfluoro aliphatic ring However, in the present invention, polymers having a ring structure such as those in which some of the fluorine atoms in the above examples are substituted with other hydrogen atoms or organic groups, or those obtained by metathesis polymerization are used. Things can also be mentioned.

Therefore, the polymer having a specific ring structure in the present invention can be obtained more smoothly and advantageously by the above-mentioned cyclopolymerization, but in particular, the polymer has two polymerizable groups with different polymerizability in the molecule, and By using a monomer in which the linear part of the connecting chain connecting these two polymerizable groups has 2 to 7 atoms, gel formation can be achieved without using ultra-high pressure conditions or large dilution conditions. The cyclization polymerization can proceed smoothly and advantageously by suppressing by-products of.

As a monomer suitable for the above-mentioned cyclization polymerization, first of all, it is desirable that the monomer has two carbon-carbon multiple bonds having different polymerizability. Usually a carbon-carbon double bond is employed. For example, a fluorine-containing monomer with two non-symmetrical multiple bonds, a vinyl group and an allyl group, a vinyl ether group and a vinyl group, a fluorine-containing multiple bond and a hydrocarbon multiple bond, a perfluorinated multiple bond and a partially fluorinated multiple bond. Examples include: Secondly, it is desirable that the number of atoms in the straight portion of the connecting chain connecting these two carbon-carbon multiple bonds is 2 to 7. The number of atoms in the straight part of the connected chain is 0~
When the number is 1, cyclization polymerization is difficult to occur, and the same is true when the number is 8 or more. Generally preferred is a case where the number of atoms is 2 to 5.

Furthermore, the connecting chain is not limited to a straight line, and may have a side chain structure or a ring structure, and the constituent atoms are not limited to carbon atoms, but may include heteroatoms such as O, S, and N. . Thirdly, it is desirable that the fluorine content be 8-10% by weight or more. If the fluorine content is too low, the specificity of fluorine atoms will be difficult to exhibit. Naturally, perfluoromonomers are preferably employed.

Specific examples of the above-mentioned specific fluorine-containing monomer include CF2
=CFOCF2CF=CF2. CF2=CFOCF2C
F2CF=CF2CF2 =CFOCF2CFCF=C
F2. CF2=CFOCF20CF2CF=CF2藝CF3 CF3 CF2=CFCF2CF2CH=CH2, CF2-CF
CF2CFCH=CH2 CF3 CF2=CHOCH2CH2CF=CF2. CH2-C
FCOCH2CH2CF=CF21 CF2=CFOCF2CF=CF(2, CF2=CFO
CF2CF2CH=CH2.

CF2=CFOCF2 (CH2), NHCC)l=c
H21 (However, X is an integer from 0 to 3) CF2=CFOCF2CF2C=CF2. CF2=CF
Examples include O(CF2)20F=CFCF3CF3 CH2=CHOCH2CH2CF2CF=CF2.

In the present invention, those having one vinyl ether group such as CF2-C10- are preferably employed in terms of polymerization reactivity, cyclization polymerization, gelation suppression, etc. In particular, perfluoroallyl vinyl ether (CF2"CFOCF2CF
=CF2) and perfluorobutenyl vinyl ether (CF2=CFOCF2CF2CF=CF2).

9-0- The above monomer components may be employed alone or in combination of two or more, and may also be copolymerized in combination with other copolymer components to the extent that the essence of these components is not impaired. There is no problem, and if necessary, the polymer may be crosslinked by some method.

The monomer to be copolymerized is not particularly limited as long as it has radical polymerizability, and may include fluorine-containing monomers,
A wide range of hydrocarbons and others may be exemplified. Of course, these monomers may be used alone in radical copolymerization with a monomer capable of introducing the specific ring structure, or two or more of these monomers may be used in combination to carry out the above copolymerization reaction. You can let them do it. In the present invention, it is usually desirable to select fluorine-containing monomers such as fluoroolefins and fluorovinylethers as other monomers. For example, preferred examples include tetrafluoroethylene, perfluoromethyl vinyl ether, perfluoropropyl vinyl ether, and perfluorovinyl ether containing a functional group such as a carboxylic acid group or a sulfonic acid group. Examples include vinyl chloride and chlorotrifluoroethylene.

As for the copolymer composition, in order to take advantage of the characteristics of the specific fluorine-containing aliphatic ring structure aimed at in the present invention, the composition of the cyclic structure is preferably 20% or more, and more preferably 4% or more.
It is desirable that it is 0% or more.

In the present invention, as a method for crosslinking the fluoropolymer, commonly used methods can be appropriately used. For example, crosslinking can be achieved by copolymerizing a monomer having a crosslinking site, by adding a crosslinking agent, or by using radiation or the like.

Furthermore, various additives such as antioxidants and ultraviolet stabilizers can be added to the fluorine-containing polymer in the present invention in order to improve practicality.

Since the polymer having a specific ring structure in the present invention is soluble in fluorine-based solvents, it is also possible to create a thin protective film by casting from a solution. Furthermore, since it is a thermoplastic resin, it has a low melting temperature and a relatively low melt viscosity, so it is easily melted by heat.

The solvent to be used is not limited as long as it dissolves the above polymer, but examples include perfluorobenzene, Perfluoro'' (trade name: fluorinated solvent manufactured by Asahi Glass Co., Ltd.), and Fluorinert (trade name: manufactured by 3M Company). perfluoro (
Liquids containing 2-butyltetrahydrofuran), trichlorotrifluoroethane, etc. are suitable. Naturally, two or more appropriate types can be used in combination as a solvent. Particularly in the case of mixed solvents, hydrocarbons, alcohols, and other organic solvents can also be used in combination. Solution concentration is 0.0
1 wt% to 50 wt%, preferably 0.1 wt% to 2
It is 0wt%.

The photoreactor of the present invention has a layer made of a polymer having a fluorine-containing aliphatic ring structure on at least the surface of the light-transmitting material that contacts the crude reaction liquid. Such a light transmitting material can be easily manufactured by coating a conventional light transmitting material such as quartz with the above-mentioned polymer solution. Alternatively, the light transmitting material may be formed by hot melt molding the above polymer.

[Function] In the present invention, the polymer having a fluorine-containing aliphatic ring structure has low crystallinity or almost no crystallinity, so it exhibits high transparency and high light transmittance even though it is a fluororesin. Moreover, since it is a fluorine-containing polymer, it is thought to have a lower refractive index than ordinary hydrocarbon resins, and is also superior in moisture resistance, weather resistance, and chemical resistance. However, it goes without saying that such explanations are provided to assist in understanding the present invention and are not intended to limit the present invention.

[Examples] Next, Examples of the present invention will be described in more detail, but it goes without saying that this description does not limit the present invention.

Synthesis Example 1 35 g of perfluoroallyl vinyl ether, 5 g of dichlorotrifluoroethane (hereinafter abbreviated as R113), 150 g of ion-exchanged water, and 35 mg of (CaFvCoo)2 as an initiator. , and placed in a pressure-resistant glass autoclave with an internal volume of 200 m1. After purging the system with nitrogen three times, suspension polymerization was carried out at 26°C for 23 hours. As a result, 28 g of polymer was obtained.

When we measured the infrared absorption spectrum of this polymer, we found that
1790 cnr due to the double bond present in the monomer
' , there was no absorption near 1840 cm-'. In addition, this polymer was dissolved in perfluorobenzene and 19F
When the NMR spectrum was measured, a spectrum showing the following repeating structure was obtained.

The intrinsic viscosity [η] of this polymer is
C-75 (Product name: Liquid whose main component is perfluoro(2-butyltetrahydrofuran) manufactured by 3M Company, hereinafter referred to as F
(abbreviated as C-75), was 0.53 at 30°C. The glass transition point of the polymer is 69°C, and it is a tough, transparent, glass-like polymer at room temperature. The 10% thermal decomposition temperature was 462°C, the refractive index was 1.34, which was 15-low, and the light transmittance was as high as 95%.

Synthesis Example 2 Perfluoroperfluorobutenyl vinyl ether 3
5g, R113 5g, ion exchange water 150g.

and as a polymerization initiator ((CH3)2 CHOCOO)
90 mg of No. 2 was placed in a pressure-resistant glass autoclave with an internal volume of 200 m1. After replacing the system with nitrogen three times,
Suspension polymerization was carried out at 0'C for 22 hours. As a result, 28 g of polymer was obtained.

The intrinsic viscosity [η] of this polymer is “′Florinat”
The F,C-7 transition point is 108°C, and it is a tough, transparent, glass-like polymer at room temperature. Also, the 10% thermal decomposition temperature is 465
°C, the refractive index is as low as 1.34, and the light transmittance is 9
It was as high as 5%.

Synthesis Example 3 20 g of 1,1,2,4,4,5.5-hebutafluoro-3-oxa-1,6-hebutadiene and 40 g of R-113 were placed in a nitrogen-substituted Mitsuro flask, and polymerization was started. After adding 20 mg of (C3F7C00)2 as an agent and purging the system with nitrogen, polymerization was carried out at 18°C for 10 hours. As a result, 10 g of polymer was obtained. This polymer was a polymer soluble in R-113, and the intrinsic viscosity [η] at 30°C in meta-xylene hexafluoride was 0.96. 19F and I
It was confirmed by HNMH that the polymer had a ring structure in its main chain.

In addition, this polymer is colorless and transparent, and has a refractive index of 1.36.
The light transmittance was as high as 93%.

Example 1 A fluorinated polyether (CH2CF2CF 20
). After heating to 100° C., the mixture was irradiated with a 450 W ultraviolet lamp while thoroughly stirring and introducing a mixed gas of F 2 /N 2 = 50/50 at a rate of 1200 m+/min. The reaction was terminated after 120 hours. Perfluoropolyether was obtained with a yield of 96%. No corrosion of the quartz ultraviolet irradiation device was observed before and after the reaction.

Example 2 When carried out under the same conditions as in Example 1 except that polyperfluoroallyl vinyl ether obtained in Synthesis Example 1 was used instead of polyperfluoroperfluorobutenyl vinyl ether, perfluoropolyether was obtained with a yield of 95%. No corrosion of the quartz ultraviolet irradiation device was observed before and after the reaction.

Example 3 Poly 1 obtained in Synthesis Example 3 was used instead of polyperfluoroperfluorobutenyl vinyl ether in Example 1.
When carried out under the same conditions as in Example 1 except that 1,2,4,4,5.5-hebutafluoro-3-oxa-1,6-hebutadiene was used, the perfluoropolyether content was 93%. It was obtained with a yield of . No corrosion of the quartz ultraviolet irradiation device was observed before and after the reaction.

[Effects of the Invention] The present invention has the excellent effect of obtaining a photoreactor with a low refractive index of 17-18- and high light transmittance by employing a polymer having a fluorine-containing alicyclic structure as a material. However, those with particularly high fluorine content are also recognized to have heat resistance, chemical resistance, moisture resistance, and stain resistance.

19-

Claims (1)

[Scope of Claims] 1. A photoreactor characterized by having a layer made of a polymer having a fluorine-containing aliphatic ring structure on at least one surface of a light-transmitting material that is in contact with a crude reaction liquid. 2. A photoreactor characterized in that a polymer having a fluorine-containing aliphatic ring structure is used as a light transmitting material.