JPH03220223A - Production of integral-skin polyurethane foam molding - Google Patents

Abstract

PURPOSE:To obtain the title good molding without using R-11 by reacting a specified high-mol.wt. polyol with a specified crosslinking agent in the presence of a specified blowing agent in a mold. CONSTITUTION:100 pts.wt. high-mol.wt. polyol mainly consisting of a polyoxyalkylenepolyol (a) based on 3C or higher oxyalkylene groups, having 5wt.% or more oxyethylene groups at molecular ends, a total oxyethylene group content of 12wt.% or less and a hydroxyl value of 80 or less is reacted with a polyisocyanate and 30 pts.wt. or less mixture of 3 pts.wt. or more crosslinking agent (b) having at least two functional groups selected from among hydroxyl, prim. amino and sec. amino and a molecular weight per functional group of below 150 with 3 pts.wt. or more compound (c) having at least two said functional groups, a molecular weight per functional group of 600 or less and an aromatic ring and being the same or different from component (b) in the presence of a catalyst, 5-25 pts.wt. blowing agent containing a halohydrocarbon, a foam stabilizer, etc., in a mold.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing integral skin polyurethane foam using a specific blowing agent.

[Prior art] Polyurethane foam molded products with integral skin have a skin layer and a foam layer that are integrally molded, so they have excellent elasticity and tactility, and are therefore used for automobile interiors such as steering wheels, crash pads, headrests, and armrests. Often used for parts. Recently, opportunities for use have expanded to fields other than these, such as housings for office equipment and furniture.

Polyurethane foam with integral skin uses a high molecular weight polyol, a crosslinking agent, and a polyisocyanate as reaction raw materials, which are reacted and cured in a mold in the presence of a catalyst, blowing agent, foam stabilizer, and other auxiliary agents. Manufactured by Molding is performed by injecting a mixture of the above-mentioned raw materials into a mold, and a low-pressure foaming machine or a high-pressure foaming machine (RIM machine) is used for mixing and injecting the raw materials.

[Problem to be solved by the invention] In order to manufacture a molded product of polyurethane foam with integral skin (hereinafter referred to as integral foam),
The use of blowing agents consisting of low-boiling organic compounds is essential.

Conventionally, this blowing agent is R-11 or Freon-1.
Trichlorofluoromethane (boiling point 2
3.8°C) was used. However, due to the occurrence of ozone problems in recent years, the amount of R-11 used must be suppressed, and it is becoming increasingly difficult to use this R-11. As a low-boiling organic compound to replace R-11, halogenated hydrocarbons having hydrogen atoms have been proposed based on ODP (ozone depletion potential) data. For example, representative examples include 1,1-dichloro-2,2,2-trifluoroethane, abbreviated as R-123, 1,1-diccoro-1-fluoroethane, abbreviated as R-141b, and methylene chloride. . However, it has been found that the blowing agent replacing R-11 has properties different from R-11 and cannot simply be used as a substitute for R-11. For example, in a conventional integral form manufacturing recipe, simply R-
When 11 is replaced with a halogenated hydrocarbon having a hydrogen atom such as R-123, R-141b, or methylene chloride, the foam taken out from the mold shrinks (disintegration).
It was found that it causes

The inventor believes that this is R-123, R-123 compared to R-11.
We speculated that the reason for this is that 141b and methylene chloride have high hydrophilic properties and easily interact with high molecular weight polyols.The reason for this is thought to be the presence of hydrogen atoms in the halogenated hydrocarbon.Therefore, The use of relatively hydrophobic high molecular weight polyols was considered, but even this did not necessarily lead to a sufficient solution to the problem.

[Means for Solving the Problems] As a result of further studies in order to solve the above problems, the inventors of the present invention found that in addition to using a relatively hydrophobic high molecular weight polyol, the crosslinking agent was changed to a more hydrophobic one. It has been found that the problem can be solved by using a highly hydrophobic reactive raw material in addition to the crosslinking agent. This third compound has a molecular weight per functional group lower than that of the high molecular weight polyol and has an aromatic nucleus, and those having a lower molecular weight can also be considered as crosslinking agents. The technical gist of the present invention is as follows.

A molded article of polyurethane foam with an integral skin is produced by reacting a high molecular weight polyol, a crosslinking agent, and a polyisocyanate as main reaction materials in a mold in the presence of auxiliary agents such as a catalyst, a blowing agent, and a foam stabilizer. In the method, the oxyethylene group is mainly composed of an oxyalkylene group having 3 or more carbon atoms, has at least 5% of oxyethylene groups at the end of the molecule, and has a total oxyethylene group content of 12% by weight or less,
Polyoxyalkylene polyol with a hydroxyl value of 80 or less (
A high molecular weight polyol containing a) as a main component, based on 100 parts by weight of the polyoxyalkylene polyol (a),
It has two or more functional groups selected from a hydroxyl group, a primary amino group, and a secondary amino group, and has a molecular weight of 150 per functional group.
having a crosslinking agent (b) of less than
A compound (c) of the same type or different type from the crosslinking agent (b)
), a blowing agent 5 containing 3 parts by weight or more of a compound having a molecular weight per functional group of less than 150, 3 parts by weight or more of a compound having an aromatic nucleus and 30 parts by weight or less in total, and a halogenated hydrocarbon having a hydrogen atom. 1. A method for producing a polyurethane foam molded product with an integral skin, characterized by using ~25 parts by weight.

The reaction raw materials for producing the integral-skinned polyurethane foam of the present invention are mainly high molecular weight polyol (a), crosslinking agent (b) and/or the below-mentioned compound (c), and polyisocyanate.

In addition, relatively small amounts of the auxiliary agents described below are often used.

Examples of high molecular weight polyols include high molecular weight polyols having a hydroxyl value of 80 or less (molecular weight per hydroxyl group of about 700 or more) and an average number of hydroxyl groups per molecule of 1.8 or more, and mixtures of two or more thereof, including polyoxyalkylene A material containing polyol as a main component is used. A more preferable hydroxyl value is 5 to 60, particularly 20 to 45. The number of hydroxyl groups per molecule is more preferably 2 to 4, particularly 2 to 3.

Other high molecular weight polyols other than polyoxyalkylene polyols can be polyester polyols, hydroxyl group-containing hydrocarbon polymers, and other high molecular weight polyols that are normally used as raw materials for polyurethane foam, and the amount used is 0 to 100% of the total high molecular weight polyols. 30% by weight, especially 0-15% by weight is preferred.

The main component of the high molecular weight polyol is polyoxyalkylene polyol, and its hydroxylization and number of hydroxyl groups are preferably within the above ranges. Hereinafter, this polyoxyalkylene polyol will be referred to as polyoxyalkylene polyol (a).
That's what it means.

The polyoxyalkylene polyol (a) mainly contains an oxylkylene group having 3 or more carbon atoms such as an oxypropylene group, a 1,2- or 2,3-oxybutylene group, or an oxytetramethylene group. Those having less than the total amount of oxyethylene groups are used. Oxyethylene groups may be present in the polyoxyalkylene silver white in a random or block form, but the presence of 5% by weight or more at least at the end of the polyoxyalkylene chain ensures highly reactive hydroxyl groups. Necessary for a reason.

The content of oxyethylene groups in the entire molecule must be 12% by weight or less. This is because if the amount of oxyethylene groups in the entire molecule is high, the hydrophilicity of the polyoxyalkylene polyol becomes too high. From the viewpoint of ensuring reactivity, it is preferable that the amount of terminal oxyethylene groups be higher, and in view of the balance between the two, it is preferable that substantially all of the oxyethylene groups exist at the ends of the oxyethylene chains.

A more preferable amount of oxyethylene groups is 10% by weight or less, and therefore, a polyoxyalkylene polyol having 5 to 10% by weight of oxyethylene groups at the molecular terminal and substantially no oxyethylene groups in the molecular chain is used. Most preferred. Particularly preferably, 5 to 12% by weight at the end of the molecular chain.
In particular, it is a polyoxybrobyleneoxyethylene polyol having 5 to 10% by weight of oxyethylene groups only at the ends.

The high molecular weight polyols described above may be used in combination with small amounts of other high molecular weight active hydrogen compounds and may also contain other ingredients such as fillers. A typical example of the latter is a polymer-dispersed polyol, also called a polymer polyol. This polymer-dispersed polyol uses a high molecular weight polyol as a dispersion medium,
This is a dispersion of fine polymer particles containing fine polymer particles as a dispersion with good dispersion stability.

Polymer particles include addition polymer particles and condensation polymer particles, which are produced by polymerizing polymer raw materials such as monomers in a dispersion medium, and by blending separately produced polymer particles with high molecular weight polyol. Manufactured by. The content of polymer fine particles is usually 5 to 45% by weight. Further, even a polymer-dispersed polyol obtained by polymerizing a polymer raw material in a high-molecular-weight polyol can be diluted with a high-molecular-weight polyol afterwards.

The above polyoxyalkylene polyol (a) is used as the high molecular weight polyol of the dispersion medium of the polymer-dispersed polyol. Further, the hydroxyl value of the polymer-dispersed polyol is lower than the hydroxyl value of the high molecular weight polyol of the dispersion medium in accordance with the amount of polymer fine particles. In the present invention, the amount of polymer fine particles of the polymer-dispersed polyol (which may be a diluted product) is preferably 1 to 30% by weight. Furthermore, a high molecular weight polyol blended with inorganic fine particles such as silica fine particles instead of polymer fine particles can also be used.

The crosslinking agent (b) is a compound having a total of two or more functional groups selected from a hydroxyl group, a primary amino group, and a secondary amino group and a molecular weight of less than 150 per functional group, and a mixture of two or more thereof. In particular, compounds having a molecular weight per functional group of less than 100 are preferred. The number of functional groups is preferably 2 to 3, particularly 2. The hydroxyl group is an alcoholic hydroxyl group, especially 1
A grade alcoholic hydroxyl group is preferred.

Examples of crosslinking agents include polyhydric alcohols, alkanolamines, and polyamines, and alkylene oxide adducts of these can also be used as long as they have a low molecular weight. Specifically, for example, ethylene glycol, diethylene glycol, dipropylene glycol, 1.4-butanediol, neopentyl glycol, 1.6-hexanediol, glycerin, bisphenol A-alkylene oxide adduct, monoethanolamine, jetanol. Examples include amines, triethanolamine, diisopropaturamine, triisopropaturamine, ethylenediamine, propylenediamine, diaminocyclohexane, isophoronediamine, diaminobenzene, toluenediamine, diphenylmethanediamine, and xylylenediamine.

Compound (c) is a reaction raw material for improving the solubility of the blowing agent, and like the crosslinking agent (b), it has two or more functional groups, the molecular weight per functional group is 600 or less, and it has an aromatic It is a compound with a nucleus. This compound (c) may be the same type of compound as the crosslinking agent. For example, the above-mentioned crosslinking agent (b) has an aromatic nucleus having a molecular weight of less than 150, particularly less than 100, per functional group. Therefore, a single compound can be used as the crosslinking agent (b) and the compound (c), and of course two or more types within the category of the crosslinking agent (b) can be used (for example, a certain crosslinking agent has an aromatic nucleus). (such as a combination in which the crosslinking agent does not have an aromatic nucleus and the other crosslinking agent has an aromatic nucleus). Preferably, the compound (c) is a compound having a higher molecular weight per functional group than the crosslinking agent (b) used (if there are two or more types of crosslinking agents (b), the average molecular weight is the subject of comparison). More preferably, the molecular weight per functional group is higher than that of the crosslinking agent (b), especially 100
It is a compound with a higher molecular weight. Furthermore, compound (c)
The molecular weight per functional group of is from 100 to 400, especially from 150 to
300 is preferred, and the number of functional groups is preferably 2 to 3, particularly 2. Further, as the functional group, an alcoholic hydroxyl group is preferable.

As the compound (c), polyhydric alcohols having an aromatic nucleus (for example, xylylene glycol), polyhydric phenol-alkylene oxide adducts, aromatic nucleus-containing amine-alkylene oxide adducts, etc. are preferable. Furthermore, polyols obtained by adding aromatic nuclei such as styrene oxide to various polyvalent initiators can also be used. Particularly preferred are compounds obtained by adding an alkylene oxide having 3 or more carbon atoms, particularly propylene oxide, to diphenols or aromatic nucleus-containing amines having two amine hydrogen atoms. As a diphenol, bisphenol A
(dihydroxydiphenylpropane), dihydroxydiphenylmethane, dihydroxydiphenyl ether, dihydroxybiphenyl, catechol, dihydroxynaphthalene, etc. Aminic hydrogen atom refers to a hydrogen atom of an amino group, and has a functionality of 1 for alkylene oxide.
In the case of a primary amino group, it is difunctional, and in the case of a secondary amino group, it is l-functional. Therefore, to produce a bifunctional alkylene oxide adduct, a monoamine is used when it has a primary amino group, and a diamine is used when it has a secondary amino group. Examples of the aromatic nucleus-containing amine include aniline, toluidine, benzylamine, N,N-dialkylphenylenediamine, and aminonaphthalene. The amount of alkylene oxide added to these aromatic nucleus-containing compounds is suitably 1 to 8 molecules per phenolic hydroxyl group or amine hydrogen atom, preferably 1 to 6 molecules, particularly preferably 1.5 to 4 molecules. .

The total amount of the crosslinking agent (b) and compound (c) required is 6 to 30 parts by weight based on 100 parts by weight of the polyoxyalkylene polyol (a). In addition, a small amount of the compound having an aromatic nucleus (at least 3 parts by weight is required, and at least 3 parts by weight of a compound having a molecular weight per functional group of less than 150, especially less than 100).Therefore, all of these requirements are satisfied. If it is a single compound, it is 6 parts by weight or more, and if they are different types of compounds, at least 3 parts by weight each is required.The upper limit of the amount used is 20 parts by weight, The upper limit is 30 parts by weight in total. Preferably 3 to 15 parts by weight each, especially 5 to 15 parts by weight of crosslinking agent (b) and 3 to 10 parts by weight of compound (c), in a total of 8 to 25 parts by weight. It is preferable that there be.

As the blowing agent, water or a low-boiling organic compound is used, but in the case of integral foam, the amount of water used is small or substantially not used compared to the production of ordinary polyurethane foam. Typical examples of low-boiling organic compounds include low-boiling hydrocarbons and halogenated hydrocarbons. As halogenated hydrocarbons, in place of trichlorofluoromethane, which has been widely used in the past, in the present invention, halogenated hydrocarbons with less oxidation problems are mainly used. It is a halogenated hydrocarbon.

The boiling point of this halogenated hydrocarbon having hydrogen atoms is 15
~50°C is preferred, but halogenated hydrocarbons having hydrogen atoms outside this boiling range can also be used. For example, a halogenated hydrocarbon having a hydrogen atom having a boiling point of 0° C. or lower, such as monochlorodifluoromethane (R-22), can also be used.

A particularly preferred boiling point range is 20-45°C. Such halogenated hydrocarbons include the above-mentioned R-123 (bp
27.1℃), R-141b (bp 32.0℃), methylene chloride (bp 40.l'c),
Dichloro-1,1,2-trifluoroethane (R-12
3a; bp28.2°C), 1,1-dichloro-1,
2,2-trifluoroethane (R-123b, bp
30.3°C), 1-chloro-2,2-difluoroethane (R-142, bp 35.1°C), l-chloro-1,2
-difluoroethane (R-142a; bp32.0
°C), 1,1,1,2-tetrafluoroethane (R
-134a; bp -26,5°C), monochlorodifluoromethane (R-22, bp -40,8°C), 1.
1-difluoroethane (R-152a; bp 25
．． 0°C) Monochloro-1.2,2.2-tetrafluoroethane (R-124, bp -12°C) Pentafluoroethane (R-125; bp -48, 5°C), 3.3
-dichloro-1,l.

1.2.2-pentafluoropropane (R-225ca
; bp51.5°C) 1,3-dichloro-1,1,2
,2,3-pentafluoropropane (R-225cb
; bp56. R-C) and the like, and two or more of these can be used in combination. Particularly preferably, R-
123, R-141b, R-22, methylene chloride, and mixtures of two or more thereof. Further, as the halogenated hydrocarbon blowing agent, the above-mentioned specific halogenated hydrocarbon may be used in combination with a smaller amount of a low-boiling point organic compound such as another halogenated hydrocarbon. Although the proportion of the halogenated hydrocarbon used in combination is not particularly limited, it is preferably 30 wt% or more, particularly 40 wt% or more. Particularly preferably 50wt%
That's all. The low-boiling organic compound used in combination preferably has a boiling point within the above range, but may have a boiling point outside this range, such as when producing a composition that azeotropes at the boiling point within the above range. Examples of the low-boiling organic compound used in combination include halogenated hydrocarbons such as R-11, hydrocarbons, and ethers. In addition, since halogenated hydrocarbon blowing agents usually require a stabilizer, a stabilizer may be used in the present invention as well.

The amount of the blowing agent used in the present invention is preferably 5 to 25 parts by weight, particularly 10 to 20 parts by weight, based on the weight of polyoxyalkylene polyol (a) toO.

The polyisocyanate is an aromatic, aliphatic, or alicyclic compound having two or more isocyanate groups, and aromatic polyisocyanates are particularly preferred. Specific examples include tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, toridine diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, and modified products thereof. Examples of modified products include prepolymer-type modified products, carbodiimide-modified products, and nurate-modified products. The isocyanate content of the modified product is preferably 10% by weight or more, particularly 16% by weight or more. Preferably diphenylmethane diisocyanate, especially 4.
4-diphenylmethane diisocyanate and modified products thereof are used. The amount of polyisocyanate used is preferably 0.8 to 1.3 equivalents, particularly 0.95 to 1.2 equivalents, per equivalent of other reactive raw materials.

In addition to the blowing agent, the production of integral foam usually requires the use of auxiliary agents such as a catalyst and a foam stabilizer. As the catalyst, a tertiary amine catalyst, an organometallic compound such as an organic tin compound, or another catalyst for producing polyurethane foam can be used alone or in combination, and the use of a tertiary amine catalyst is particularly preferred.

Silicone compounds are widely used as foam stabilizers, and the use of silicones is also preferred in the present invention.

The silicone is preferably diorganopolysiloxane or a block copolymer of diorganopolysiloxane and polyoxyalkylene. The amount of each auxiliary agent used per 100 parts by weight of polyoxyalkylene polyol (a) is not particularly limited, but the catalyst is 0.01 to 5 parts by weight, and the foam stabilizer is 0.1 to 5 parts by weight. . In addition, various auxiliary agents can be optionally used, and examples of auxiliary agents other than those mentioned above include colorants, foam breakers, flame retardants, ultraviolet absorbers, antioxidants, light stabilizers, and fillers.

The integral foam molded article is preferably molded by a method in which a reactive mixture is injected into a mold using a high-pressure foaming machine (ie, a reaction injection molding method). The high-pressure foaming machine is preferably a type that mixes two normal liquids, one of which is
The liquid used is polyisocyanate, and the other liquids are a mixture of all raw materials other than polyisocyanate. In some cases,
It is also possible to form a reactive mixture of three components in total and inject it, including a catalyst or a foam-breaker (usually dispersed or dissolved in some high molecular weight polyol) as a separate component.

EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited to these Examples.

[Example] A mixture of a high molecular weight polyol, a crosslinking agent, a blowing agent, etc. listed in Table 1 below was charged into a tank on the polyol component side of a high-pressure foaming machine, and polyisocyanate was charged into a tank on the incyanate component side. The discharge pressure of the high pressure foaming machine is 18
0 kg/cm2, the discharge rate was 200 g/sec, and the liquid temperature of both components was adjusted to 23±3°C, and reaction sealing part molding was performed.

800mm x 400mm x 10m as mold
A mold with internal dimensions of m(t) is used, and the mold temperature is set to 45
The temperature was adjusted to ~50°C. After taking out the molded product from the mold, it was left in an atmosphere controlled at 23° C. overnight, and physical properties such as density, tensile strength, and elongation were measured. The results are shown in Tables 1 and 2. Note that the amounts of raw materials used are expressed in parts by weight, excluding polyisocyanate.

The types of raw materials used in the present examples and comparative examples are as follows.

A polyoxypropylene oxyethylene triol having a hydroxyl value of 26 and a hydroxyl group number of 3, having 8% by weight of oxyethylene groups only on the side ends of the polyol component.

A polyoxypropylene oxyethylene triol having a hydroxyl value of 28 and a hydroxyl group number of 3 and having 20% by weight of oxyethylene groups only on the side ends of the polyol component.

Polyol C: Diol obtained by adding 4 moles of propylene oxide to 1 mole of bisphenol A.

Polyol D A diol obtained by adding 4 moles of propylene oxide to 1 mole of nianiline.

EG: Ethylene glycol catalyst nitriethylene diamine-EG solution (product name “D”)
abco-EG”) Foam stabilizer: Silicone foam stabilizer (manufactured by Toshi Silicone Co., Ltd., part name “5F-2962”) Polyisocyanate: Modified diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., part name “C-1050°”)゛), isocyanate content 23% by weight. The amount of polyisocyanate used was expressed as an index (100 times the equivalent of polyisocyanate based on 1 equivalent of all raw materials reacting with incyanate groups).

Blowing agent AIR-11 Blowing agent B: R-123 Blowing agent C: R-141b Blowing agent D = methylene chloride Blowing agent E: Equal weight mixture of methylene chloride and R-11 Blowing agent FAR-22 C Effect of the invention] Implementation As is clear from the comparison between the example and the comparative example, R-123 and R-141b were used instead of the conventionally used R-11.
, R-22, or methylene chloride as a blowing agent will not produce a good integral skin. In contrast, in the present invention, the oxyethylene group content of the polyoxyalkylene polyol is made low, and the compound (c) having an aromatic nucleus is used together with (or as a crosslinking agent) the foaming agent. can be used to form a good individual skin.

Claims (1)

[Claims] 1. Integral skin is formed by reacting a high molecular weight polyol, a crosslinking agent, and a polyisocyanate as main reaction raw materials in a mold in the presence of auxiliary agents such as a catalyst, a blowing agent, and a foam stabilizer. In a method for producing a polyurethane foam molded article, the polyurethane foam has mainly oxyalkylene groups having 3 or more carbon atoms, has at least 5% by weight of oxyethylene groups at the molecular terminal, and has a total oxyethylene group content of 12% by weight or less. and a high molecular weight polyol whose main component is a polyoxyalkylene polyol (a) having a hydroxyl value of 80 or less, the polyoxyalkylene polyol (a) 1
00 parts by weight, a crosslinking agent (b) having two or more functional groups selected from a hydroxyl group, a primary amino group, and a secondary amino group and having a molecular weight per functional group of less than 150 and the above functional group A compound (c) of the same or different type as the crosslinking agent (b), which has a molecular weight of 600 or less per functional group and an aromatic nucleus, and a compound (c) with a molecular weight of less than 150 per functional group. with an integral skin characterized by using at least 3 parts by weight of a compound having an aromatic nucleus and a total of 30 parts by weight or less, and 5 to 25 parts by weight of a blowing agent containing a halogenated hydrocarbon having a hydrogen atom. Manufacturing method for polyurethane foam molded products. 2. The crosslinking agent (b) is a compound that may have an aromatic nucleus having a molecular weight per functional group of less than 100, and the compound (c) is a compound having an aromatic nucleus having a molecular weight per functional group of 100 or more, Polyoxyalkylene polyol (a) 100
2. The method according to claim 1, wherein the amount of each used is 3 parts by weight or more and a total of 25 parts by weight or less. 3. The method according to claim 1 or 2, wherein the crosslinking agent (b) is a compound having a total of two alcoholic hydroxyl groups and/or primary amino groups and a molecular weight of less than 200. 4. A claim in which the compound (c) is a compound obtained by adding an alkylene oxide to a polyfunctional phenol or an aromatic nucleus-containing amine having two or more amine hydrogen atoms and having a molecular weight per functional group of 100 or more. Paragraph 1 or 2
The method described in section. 5. The polyoxyalkylene polyol (a) has an oxyethylene group substantially only at the end of the molecule, with a hydroxyl value of 45
The method of claim 1, wherein the polyoxypropyleneoxyethylene polyol is: 6. Halogenated hydrocarbons having hydrogen atoms have a boiling point of 15
2. The method of claim 1, wherein the hydrocarbon is a halogenated hydrocarbon having hydrogen atoms at ~50<0>C. 7. Halogenated hydrocarbon having a hydrogen atom is 1,1-
Dichloro-1-fluoroethane, 1,1-dichloro-2
7. The method according to claim 6, wherein the halogenated hydrocarbon is at least one selected from , 2,2-trifluoroethane, and methylene chloride. 8. Halogenated hydrocarbon having a hydrogen atom is 1,1-
Dichloro-1-fluoroethane, 1,1-dichloro-2
, 2,2-trifluoroethane, 1,2-dichloro-1
, 1,2-trifluoroethane, 1,1-dichloro-1
, 2,2-trifluoroethane, 1-chloro-2,2-
Difluoroethane, 1,1,1,2-tetrafluoroethane, monochlorodifluoromethane, 1-chloro-1,
2-difluoroethane, 1,1-difluoroethane, monochloro-1,2,2,2-tetrafluoroethane, pentafluoroethane, 3,3-dichloro-1,1,1,
2,2-pentafluoropropane, 1,3-dichloro-
The method according to claim 1, wherein the halogenated hydrocarbon is at least one selected from 1,1,2,2,3-pentafluoropropane and methylene chloride.