JPH06329826A - Foaming agent consisting of fluorocyclobutane compound - Google Patents

Abstract

PURPOSE:To obtain the subject foaming agent useful for producing polyurethane foam, containing (substituted) fluorocyclobutane and excellent in environmental preservability, nonflammability, compatibility with raw materials for foam, heat insulating property of the foam and mechanical strengths. CONSTITUTION:The objective foaming agent contains (substituted) fluorocyclobutane of the formula [R<1>-R<8> are (fluorine substituted) 1-2C alkyl], e.g. cis-1,1,2,2,3,4-hexafluorocyclobutane, etc. Here, the foaming agent preferably contains a mixture of (A) a (substituted) fluorocyclobutane and (B) a hydrocarbon having 20-90 deg.C boiling point.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a foaming agent for the production of foamed plastics, in particular isocyanate-based foams, preferably polyurethane foams, and a process for the production of plastic foams using these foaming agents. .

In this specification, "%" and "parts" mean "wt%" and "parts by weight", respectively.

[0003]

2. Description of the Related Art As a foaming agent used for producing a plastic foam such as polyurethane foam, trichlorofluoromethane (CFC-11) has hitherto been used.
Was mainly used.

However, in recent years, it has been pointed out that, when released into the atmosphere, certain CFCs destroy the ozone layer in the stratosphere, resulting in serious adverse effects on the earth's ecosystem including humans. ing. Therefore, the use and production of CFCs, which have a high risk of ozone depletion, have been limited by international agreements. CFC above
-11 is a target of this restriction, and from this point as well, it is necessary to develop a new foaming agent that has no or low risk of causing ozone layer depletion problems.

1,1-dichloro-2,2,2-trifluoroethane (HCFC-123) and 1,1-dichloro-1-fluoroethane (HCFC-141b) are CFCs which are less likely to destroy the ozone layer. However, since they contain chlorine atoms in the molecule, they have a small effect on the ozone layer, but still retain the property of depleting the ozone layer.

Recently, as a foaming agent using a fluorinated hydrocarbon containing no chlorine atom and having no risk of destroying the ozone layer: (1) JP-A-1-135817 discloses 1,1,2,2-
Tetrafluorocyclobutane, (2) JP-A-1-313
The No. 538 1,2,3,3,4,4- hexafluoro-1-cyclobutene, (3) in _{JP-A-2-29440 CF 3 CH 2 CH 2 CF} 3, (4) JP-2- 235
No. 982 has CF ₃ CH as an HFC having 3 to 5 carbon atoms.
(CH ₃ ) CF ₃ , CF ₃ CH ₂ CF ₃ and CH ₃ C
F ₂ CH ₂ CHF ₂ , (5) HFC having 3 carbon atoms in JP-A-2-265933, and (6) JP-A-3-746.
C ₄ F ₉ H and H (CF ₂ ) ₄ H are newly proposed as HFCs in the issue.

Although these foaming agents do not have a risk of depleting the ozone layer, they are flammable and risk of fire, have poor solubility in polyols, and can be used in a limited number of polyols, or the resulting foams have There were some defects such as insufficient heat insulation performance and mechanical strength, and there was still room for improvement.

The present invention provides a foaming agent which has no danger of depleting the ozone layer, is nonflammable, has excellent compatibility with foam raw materials, and has excellent heat insulating properties and mechanical strength of the resulting foam. It is an object to provide a method for producing a plastic foam using the foaming agent.

[0009]

The present inventor has conducted extensive research in view of the above problems in the prior art, and as a result, the use of fluorocyclobutane, which may have a substituent, as a blowing agent We have found that we can achieve the purpose.

That is, the present invention provides the following foaming agents.

1. A foaming agent for a plastic foam containing fluorocyclobutane optionally having a substituent.

2. Formula (I) below:

[0013]

[Chemical 2]

(In the formula, R ^{1 to} R ⁸ are the same or different and each represents a hydrogen atom, a fluorine atom or an alkyl group having 1 or 2 carbon atoms which may be substituted with a fluorine atom.)
Item 2. A foaming agent for plastic foams according to Item 1, which contains fluorocyclobutane represented by

3. At least one of the following (1) to (7)
A foaming agent for a plastic foam according to item 1, which contains a seed; (1) cis-1,1,2,2,3,4-hexafluorocyclobutane, (2) 1,1,2,3,3,4. -Hexafluorocyclobutane, (3) 1,1,2,2,3-pentafluorocyclobutane, (4) 1,1,2,2
3,4-hexafluoro-3-trifluoromethylcyclobutane, (5) 1,1,2,3-tetrafluoro-2
-Trifluoromethylcyclobutane, (6) 1,1,2
-Trifluoro-2-trifluoromethylcyclobutane, (7) 1,1,2,2,3-pentafluoro-3-
Methylcyclobutane.

4. A foaming agent for a plastic foam containing a mixture of a fluorocyclobutane which may have a substituent and a hydrocarbon having a boiling point of 20 to 90 ° C.

The present invention also provides a method for producing a plastic foam, which comprises using the foaming agent according to any one of items 1 to 4 above.

In the present invention, examples of the "substituent having 1 or 2 carbon atoms" include methyl group, trifluoromethyl group, monofluoromethyl group, difluoromethyl group, monofluoroethyl group, difluoroethyl group, trifluoroethyl group. Group, tetrafluoroethyl group, pentafluoroethyl group and the like.

Fluorocyclobutane optionally having a substituent of the present invention (hereinafter abbreviated as "compound of the present application") is a cyclobutane derivative having at least one fluorine atom, and specifically, the following compounds are It is illustrated.

* 1,1,2,2,3,3-hexafluorocyclobutane (boiling point 32 ° C), * trans-1,1,2,2,3,4-hexafluorocyclobutane (boiling point 27 ° C), * Cis-1,1,2,2,3,4-hexafluorocyclobutane (boiling point 63 ° C.), * 1,1,2,3,3,4-hexafluorocyclobutane (boiling point 39 ° C.), * 1,1, 2,2,3-Pentafluorocyclobutane (boiling point 50 ° C.), * 1,1,2,2-Tetrafluorocyclobutane (boiling point 50 ° C.), * 1,1,2,2,3,4-hexafluoro-3 -Trifluoromethylcyclobutane (boiling point 36 ° C), * 1,1,2,3-tetrafluoro-2-trifluoromethylcyclobutane (boiling point 68 ° C), * 1,1,2-trifluoro-2-trifluoromethyl Shiku Butane (boiling point 67.5 ℃), * 1,1,2,2,3- pentafluoro-3-methyl-cyclobutane (boiling point 67.0 ° C.).

The compound of the present invention may be used alone or as a mixture of two or more kinds at any ratio. When there are cis-trans isomers, any isomer or a mixture of both isomers at any ratio may be used. Further, when it becomes an optical isomer, the present invention also includes an arbitrary mixture of R and S isomers including R isomer, S isomer or racemic isomer.

The compounds of the present invention are all known compounds and can be produced, for example, according to the methods described in the following documents.

J. Chem. Soc. , 3198, (1
961), J. Chem. Soc. , 61, (195
6), J. Chem. Soc. , 3203, (196
1), J. Chem. Soc. , Perkin Tra
ns, I, 11,801 (1983) The plastic foam produced by using the foaming agent of the present invention includes, for example, foams made of isocyanate, polyethylene, polystyrene, polyvinyl chloride and phenol / formaldehyde condensate as raw materials. However, a foam made of isocyanate as a raw material is more preferable, and a polyurethane and polyisocyanurate foam is more preferable.

Boiling point 20 to 90 ° C. to be mixed with the present compound
The preferred hydrocarbon for is isopentane (boiling point 28
° C), n-pentane (boiling point 36 ° C), cyclopentane (boiling point 50 ° C), cyclopentene (boiling point 45 ° C), n-
Hexane (boiling point 69 ° C), 2-methylpentane (boiling point 6
0 ° C.), 3-methylpentane (boiling point 63 ° C.), benzene (boiling point 80 ° C.), cyclohexane (boiling point 81 ° C.) and the like, and these can be used alone or in admixture of two or more.

The mixing ratio of the compound of the present invention and the hydrocarbon having a boiling point of 20 to 90 ° C. is: the compound of the present invention: hydrocarbon having a boiling point of 20 to 90 ° C. = about 5 to 95%: about 95 to 5%. When the compound of the present application and a hydrocarbon having a boiling point of 20 to 90 ° C. form an azeotrope, there is no change in composition, which is preferable.

The foaming agent of the present invention may be further combined with other substances, and examples of the combination substance include CFC.
11, CFC12, other low-boiling halogenated hydrocarbons, inert gas and the like.

A stabilizer may be added to the foaming agent of the present invention, if necessary. As such a stabilizer,
The following is exemplified.

* Alkenyl group-containing compound having at least one double bond: 1,4-hexadiene, allene,
1,3-butadiene, isoprene, 1,3-pentadiene, β-myrcene, isopropenyltoluene, butadiene, aroocimene,

[0029]

[Chemical 3]

* Epoxy group-containing compounds; for example, ethylene glycol diglycidyl ether, hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylpropane triglycidyl ether, glycerin polyglycidyl ether, glycid- (2-nitro- Phenyl ether), glycid-
(2-nitro-4-chloro-phenyl ether), glycid- (4-vinyl-phenyl ether), glycid-
(4-isopropenyl-phenyl ether), 1,3-
Butadienyl glycidyl ether, 3-methyl-1,3
-Butadienyl glycidyl ether, 3-vinyl-1,
3-Butadienyl glycidyl ether, benzoic acid glycidyl ester, acrylic acid glycidyl ester, furancarboxylic acid glycidyl ester, N, N-diglycidyl aniline, glycidyl phenyl ether, glycidyl-
p-isopropenyl phenyl ether, glycidyl-p
-Nitrophenyl ether and the like.

* Acrylic acid esters and methacrylic acid esters; for example, 2-hydroxyethyl methacrylate, diethylene glycol monoethyl methacrylate, methoxy polyethylene glycol monoethyl methacrylate and the like.

* Polyalkoxylated methacrylates;
For example, polyethylene glycol monoethyl methacrylate, polypropylene glycol monoethyl methacrylate, etc.

* Phenols; for example, 2,6-di-t
-Butyl-p-cresol, thymol, pt-butylphenol, eugenol, isoeugenol, butylhydroxyanisole, t-butylcatechol, 2,5
-Di-t-butyl hydroquinone and the like.

* Cyclic alkylene carbonates such as propylene carbonate, 1,2-butylene carbonate, styrene carbonate, vinyl ethylene carbonate and phenyl ethylene carbonate.

* Nitro compounds; for example, nitromethane, nitroethane, nitropropane, nitrobenzene and the like.

* Benzophenones; for example, t-butylchlorobenzophenone, isoamylbenzophenone and the like.

* Benzotriazoles; hydroxyphenylbenzotriazole, hydroxymethylphenylbenzotriazole, 2- (3 ', 5'-di-t-butyl-2'-hydroxyphenyl) benzotriazole and the like.

* Phenylsalicylates; for example, phenylsalicylate, p-octylphenylsalicylate and the like.

These stabilizers may be used alone or in combination of two or more kinds. The amount of these stabilizers used may vary depending on the type of the stabilizer itself, the composition of the foaming component, etc., but usually about 0.05 to 5% by weight of the foaming component is suitable, and 0.2 to 1. More preferably, it is set to about 0%. If the amount of the stabilizer is too small, the reaction between the polyol and the foaming material cannot be effectively prevented. On the other hand, even if the amount used exceeds 5%, substantial improvement in the stabilizing effect cannot be expected.

The foaming agent of the present invention can be used in the same manner as a known foaming agent for producing a plastic foam.

As the foaming raw material, well-known raw materials can be widely used.

The amount of the foaming agent of the present invention used with respect to the foaming raw material is not different from that of the known foaming agent and is appropriately determined depending on the kind of the foaming raw material, the desired density of the foamed material, etc. The ratio of the foaming agent to the total of the foaming agents is about 1 to 40%, preferably about 2 to 20%.

The production of a foam using the foaming agent of the present invention may be carried out in the same manner as a known method. For example, a method of reacting an active hydrogen compound having two or more active hydrogen-containing groups such as a polyol with a polyisocyanate compound in the presence of a catalyst and a foaming agent is widely known in the production of polyurethane foams. It can also be produced by a one-step method known per se, a prepolymer method, a block foaming method or a double belt conveyor method.

In the production method of the present invention, known foam stabilizers, catalysts and the like can be used. Examples of the foam stabilizer include a silicone-based foam stabilizer and a fluorine-containing foam stabilizer, which are used in an amount of about 0.1 to 2% based on the foaming raw material. Examples of the catalyst include tertiary amine catalysts such as triethylenediamine, metal compound catalysts such as organic tin compounds, and the like.
~ 5% is used.

In addition to the foaming agent of the present invention, water, a filler, a coloring agent, a flame retardant, etc. may be added, if necessary.

[0046]

According to the present invention, the following effects are achieved.

(1) The ozone depletion potential of the compound of the present invention is 0, and there is no danger of depleting the ozone layer.

(2) The foaming agent of the present invention is nonflammable depending on the mixing ratio and has low toxicity, and therefore is safe in operation.

(3) The foaming agent of the present invention has good compatibility with a polyol and is therefore suitable for producing a urethane foam.

(4) The foaming agent of the present invention has good storage stability.

(5) Since the plastic foam obtained by using the foaming agent of the present invention is closed cells, it has excellent heat insulation, dimensional stability and compressive strength as well as appearance and uniformity.

[0052]

EXAMPLES Examples and comparative examples will be shown below to further clarify the features of the present invention.

In Example 1 below, the foaming agents (a) to (f) are as follows. Foaming agent (a):
1,1,2,3,3,4-hexafluorocyclobutane, foaming agent (b): 1,1,2,3,3,4-hexafluorocyclobutane / cyclopentane (80/20) foaming agent (c) : Cis-1,1,2,2,3,4-hexafluorocyclobutane Foaming agent (d): cis-1,1,2,2,3,4-hexafluorocyclobutane / cyclopentane (80/20) foaming Agent (e): 1,1,2,2,3,3-hexafluorocyclobutane, Foaming agent (f): trans-1,1,2,2,3,4-hexafluorocyclobutane

[0054]

Example 1 * Compatibility with Polyol The stability of a mixture of the foaming agents (a) to (v) of the present invention and a polyol, that is, a premix was examined by the following method.

A total of 30 g of the foaming agent (a) to the foaming agent (f) of the present invention and the polyol A, B or C was placed in a glass bottle with a screw cap having a capacity of 50 ml, and the mixture was shaken with a shaker.
After shaking for 0 minutes, the mixture was allowed to stand at room temperature for 5 hours, and the presence or absence of separation was visually confirmed.

The following polyols A, B and C were used.

* Polyol A: Polyether polyol having a hydroxyl value of 770 obtained by reacting ethylenediamine with propylene oxide * Polyol B: Polyether polyol having a hydroxyl value of 430 obtained by reacting tolylenediamine with propylene oxide * Polyol C: Sucrose The results of the polyether polyol having a hydroxyl value of 430 reacted with propylene oxide are shown in Table 2 below.

Table 2 Polyol foaming agent (a) (%) Foaming agent (b) (%) 20 20 A ○ ○ B ○ ○ C ○ ○ Table 2 (continued) Polyol foaming agent (c) (%) foaming Agent (d) (%) 20 20 A ○ ○ B ○ ○ C ○ ○ Table 2 (continued) Polyol foaming agent (e) (%) Foaming agent (f) (%) 20 30 20 30 A ○ ○ ○ ○ B ○○○○ C ○○○○ From the results shown in Table 2, the blowing agent of the present invention shows good compatibility with the polyol at the mixing ratio actually used, and can form a stable premix. confirmed.

[0059]

Example 2 * Production of Foam (1) Production of Foam Using Polyol B 100 g of Polyol B, 2 g of silicone type foam stabilizer, 2 g of water, N, N, N ', N'-tetramethyl as catalyst 2 g of hexane-1,6-diamine and 15 g of the foaming agent (a) of the present invention, 12 g of the foaming agent (b), and the foaming agent (c).
15 g, foaming agent (d) 12 g, foaming agent (e) 16
g or a foaming agent (f) 16 g was mixed and vigorously stirred. This stirred mixture and 148 g of crude polymethylene polyphenyl isocyanate were mixed and foamed to obtain a rigid polyurethane foam.

The physical data of the foam and of the foam are shown in Table 3 below.

Table 3 Physical Properties Foaming Agent (a) Foaming Agent (b) Cream Time (sec) 10 12 Gel Time (sec) 62 65 Free Total Density (kg / m ³ ) 34 33 Compressive Strength (kg / cm) ²⁾ 1.30 1.32 dimensional stability -0.3 -0.5 (-20 ℃, 24 h (delta%)) thermal conductivity 0.0185 0.0188 (kcal / m · hr · ℃) first 3 Table (continued) Physical properties Foaming agent (c) Foaming agent (d) Cream time (seconds) 10 12 Gel time (seconds) 62 65 Free total density (kg / m ³ ) 34 33 Compressive strength (kg / cm ² ) 1.30 1.32 Dimensional stability −0.3 −0.5 (−20 ° C., 24 hours (Δ%)) Thermal conductivity 0.0185 0.0188 (kcal / m · hr · ° C.) Third Table (continued) physical properties blowing agent (e) blowing agents (f) Cream time ( ) 8 8 Gel Time (sec) 60 58 Free Total density (kg / m ³⁾ 25 25 compressive strength (kg / cm ²⁾ 1.38 1.38 dimensional stability -0.20 -0.20 (-20 ° C. , 24 hours (Δ%)) Thermal conductivity 0.0184 0.0182 (kcal / m · hr · ° C) In addition, the evaluation method of the foaming agent of the present invention is JIS A 951.
According to 4.

From the results shown in Table 3, it was confirmed that by using the foaming agent of the present invention, a foam excellent in heat insulating property, compressive strength and dimensional stability can be obtained.

[0063]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Tatsumi Tsuchiya 1-1, Nishiichitsuya, Settsu City, Osaka Prefecture Daikin Industries, Ltd. Yodogawa Works (72) Akinori Yamamoto 1-1, Nishiichitsuya, Settsu City, Osaka Prefecture Daikin Industries, Ltd. Yodogawa Manufacturing Co., Ltd.

Claims (5)

[Claims] 1. A foaming agent for a plastic foam containing fluorocyclobutane optionally having a substituent. 2. The following formula (I): (In the formula, R ^{1 to} R ⁸ are the same or different and are hydrogen atoms,
A fluorine atom or an alkyl group having 1 or 2 carbon atoms which may be substituted with a fluorine atom is shown. The foaming agent for plastic foams according to claim 1, comprising fluorocyclobutane represented by the formula (1). 3. A foaming agent for a plastic foam according to claim 1, containing at least one of the following (1) to (7); (1) cis-1,1,2,2,3,4- Hexafluorocyclobutane, (2) 1,1,2,3,3,4-hexafluorocyclobutane, (3) 1,1,2,2,3-pentafluorocyclobutane, (4) 1,1,2,2 ，
3,4-hexafluoro-3-trifluoromethylcyclobutane, (5) 1,1,2,3-tetrafluoro-2
-Trifluoromethylcyclobutane, (6) 1,1,2
-Trifluoro-2-trifluoromethylcyclobutane, (7) 1,1,2,2,3-pentafluoro-3-
Methylcyclobutane. 4. A foaming agent for a plastic foam, which comprises a mixture of optionally substituted fluorocyclobutane and a hydrocarbon having a boiling point of 20 to 90 ° C. 5. A method for producing a plastic foam, which comprises using the foaming agent according to any one of claims 1 to 4.