JPH05179041A - Blowing agent comprising fluoromethylpropane - Google Patents

Abstract

PURPOSE:To obtain the subject blowing agent useful for polyurethane, polyisocyanurate, etc., having no danger of destroying an ozone layer, non- combustibility, excellent compatibility, heat insulating properties and mechanical strength, comprising a specific fluorine-containing compound. CONSTITUTION:The blowing agent comprising a compound of the formula (X is H or F). Polyurethane, polyisocyanurate, PE, PS, PVC, etc., is preferably blended with 2-20% of the blowing agent and foamed.

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 this foaming agent. ..

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

[0003]

2. Description of the Related Art As a foaming agent used in the production of plastic foams 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 depletion of the ozone layer, have been limited by international agreements. CFC above
-11 is a target of this restriction, and also from this point, it is necessary to develop a new foaming agent that has no risk of causing the ozone layer depletion problem or has a low risk thereof.

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 little effect on the ozone layer, but still have the property of depleting the ozone layer.

Recently, as a blowing agent using a fluorinated hydrocarbon containing no chlorine atom and having no risk of depleting the ozone layer: (1) JP-A-2-29440 discloses CF ₃ CH ₂ CH ₂
CF ₃ , (2) Japanese Patent Application Laid-Open No. 2-235982 has 3 carbon atoms.
5 HFCs of CF ₃ CH (CH ₃ ) CF ₃ , CF
₃ CH ₂ CF ₃ and CH ₃ CF ₂ CH ₂ CHF ₂ ,
(3) HF having 3 carbon atoms is disclosed in JP-A-2-265933.
C and (4) JP-A-3-746 newly proposes C ₄ F ₉ H and H (CF ₂ ) ₄ H as HFCs.

Although these foaming agents do not have a risk of depleting the ozone layer, they are flammable and have a 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 destroying 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]

As a result of repeated studies in view of the above problems in the prior art, the present inventor has obtained the following formula (I): CF ₃ CH (CHFX) CF ₃ (I) In the above, X represents a hydrogen atom or a fluorine atom. It was found that the above-mentioned object can be achieved by using [] as a foaming agent.

That is, the present invention provides the following formula (I): CF ₃ CH (CHFX) CF ₃ (I) [wherein, X represents a hydrogen atom or a fluorine atom. ] To provide a foaming agent for a plastic foam.

The present invention also provides a foaming agent represented by the following formula (I): CF ₃ CH (CHFX) CF ₃ (I) [wherein, X represents a hydrogen atom or a fluorine atom. ] (Hereinafter, simply referred to as HFC338 or HFC347,
These names shall not include the other isomers that may be naturally included in this nomenclature. ) Is used to provide a method for producing a plastic foam.

HFC338 (2-difluoromethyl-1,1,1,3,3,3-hexafluoropropane) and HFC347 (2-monofluoromethyl-1,1,1,3,3,3) used in the present invention. 3-hexafluoropropane) is a known compound, for example HFC338 is
It can be produced by hydrogenating octafluoroisobutylene as a raw material under a palladium catalyst. In addition, HFC3
47 can be produced by hydrogenating 1,3,3,3-tetrafluoro-2-trifluoromethylpropane as a raw material under a palladium catalyst (Izv. Akad. Na).
ukSSSSRSer. See Khim, 1958, 906).

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. Foams made of isocyanate as a raw material, more preferably polyurethane and polyisocyanurate foams are preferable.

The physical properties of HFC338 and HFC347 are as shown in Table 1 below.

Table 1 Physical properties HFC338 HFC347 Molecular formula CF ₃ CH (CHF ₂ ) CF ₃ CF ₃ CH (CH ₂ F) CF ₃ Molecular weight 202 184 Boiling point 17 ° C. 40 ° C. Ozone depletion potential 0 0 The blowing agent of the present invention is It can be used alone or in combination with other foaming agents or water. Examples of other foaming agents include CFC11 and CFC12, other low-boiling halogenated hydrocarbons, low-boiling hydrocarbons such as n-pentane and isopentane, and an inert gas.

It is more preferable that these combined substances form an azeotrope with the blowing agent of the present invention. For example, HFC338 and HFC347 and n-pentane or isopentane which is a low boiling point hydrocarbon are the blowing agent of the present invention: low boiling point hydrocarbon = 95. ~ 80
%: An azeotrope is formed in the composition range of 5 to 20%.

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,

[0019]

[Chemical 1]

* 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. It is more preferable to set it to about 0%. If the amount of the stabilizer is too small, the reaction between the polyol and the foam 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, 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 foam, 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 known one-step method, 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 and the like can be added, if necessary.

[0036]

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

(1) The HFC338 and HFC347 used in the present invention have an ozone depletion potential of 0, and there is no risk of depleting the ozone layer.

(2) Since the foaming agent of the present invention is nonflammable and has low toxicity, it is safe in work.

(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 has closed cells, it has excellent heat insulating properties, dimensional stability, compressive strength, and appearance and uniformity.

[0042]

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

[0043]

Example 1 * Compatibility with polyol The stability of a mixture of the foaming agent 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 of the present invention (HFC338 or HFC347) and polyol A, B or C was placed in a glass bottle with a screw stopper having a capacity of 50 ml, and the mixture was shaken with a shaker for 10 minutes and then allowed to stand at room temperature for 5 hours. Then, 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: Propylene oxide added to sucrose The results of the reacted polyether polyol having a hydroxyl value of 430 are shown in Table 2 below.

Table 2 Polyol HFC-338 (%) HFC-347 (%) 20 30 20 30 A A ○ ○ ○ ○ B ○ ○ ○ ○ C ○ ○ ○ ○ From the results in Table 2, the foaming agent of the present invention. Was confirmed to have good compatibility with the polyol at the mixing ratio actually used and to form a stable premix.

[0048]

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 Hexane-1,6-diamine 2 g and HFC3 of the present invention
20 g 38 or 18 g HFC347 were mixed and stirred vigorously. This stirred mixture and 148 g of crude polymethylene polyphenyl isocyanate were mixed and foamed to obtain a rigid polyurethane foam.

Physical data of the foam and of the foam are shown in Table 3-A below.

Table 3-A Physical Properties HFC338 HFC347 Cream Time (sec) 8 10 Gel Time (sec) 60 65 Free Total Density (kg / m ³ ) 24 24 Compressive Strength (kg / cm ² ) 1.431 .40 Dimensional stability −0.10 −0.20 (−20 ° C., 24 hours (Δ%)) Thermal conductivity 0.0166 0.0178 (kcal / m · hr · ° C.) (2) Use Polyol C Production of the foamed product: Polyol C 100 g, silicone type foam stabilizer 2 g, water 0.2 g, diethyl ethanolamine 1.5 as a catalyst
g, 0.15 g of dibutyltin dilaurate and 20 g of HFC338 or 18 g of HFC347 of the present invention were mixed and vigorously stirred. This stirred mixture and 96 g of crude tolylene diisocyanate were mixed and foamed to obtain a rigid polyurethane foam.

Physical data for the resulting foams are shown in Table 3-B below.

Table 3-B Physical properties HFC338 HFC347 Density (kg / m ³ ) 34 34 Compressive strength (kg / cm ² ) Parallel 3.20 3.15 Vertical 1.25 1.15 Dimensional stability (Δ% ) 110 ° C., 7 days +1.4 +1.4 70 ° C., 95% RH, 7 days +6.0 +7.0 −20 ° C., 7 days −0.2 −0.3 In addition, the evaluation method of the foaming agent of the present invention. Is JIS A 951
According to 4.

From the results of Tables 3-A and 3-B,
It was confirmed that the foaming agent of the present invention can be used to obtain a foam having excellent heat insulating properties, compressive strength and dimensional stability.

[0054]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Ide 1-1 Nishiichitsuya, Settsu-shi, Osaka Daikin Industries, Ltd. Yodogawa Manufacturing Co., Ltd. (72) Tatsumi Tsuchiya Nishiichitsuya 1-1, Settsu-shi, Osaka Daikin Industries Yodogawa Manufacturing Co., Ltd. (72) Inventor Katsuji Fujiwara 1-1 Nishiichitsuya, Settsu-shi, Osaka Daikin Industry Co., Ltd. Yodogawa Manufacturing Co., Ltd.

Claims (2)

[Claims] 1. The following formula (I): CF ₃ CH (CHFX) CF ₃ (I) [wherein, X represents a hydrogen atom or a fluorine atom. ] A foaming agent for plastic foams. 2. A foaming agent represented by the following formula (I): CF ₃ CH (CHFX) CF ₃ (I) [wherein, X represents a hydrogen atom or a fluorine atom. ] The manufacturing method of the plastic foam characterized by using these.