JPH05179043A - Blowing agent comprising fluorobutene and production of plastic foam - Google Patents

Abstract

(57) [Summary] [Structure] 1. A foaming agent for producing a plastic foam, which comprises cis-1,1,1,4,4,4-hexafluoro-2-butene. 2. A method for producing a plastic foam, which comprises using cis-1,1,1,4,4,4-hexafluoro-2-butene as a foaming agent. [Effect] With the use of a foaming agent that has no danger of destroying the ozone layer, is nonflammable, and has excellent compatibility with the foam material, it has excellent heat insulation performance, mechanical strength, and dimensional stability. A plastic foam is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a plastic foam,
In particular, it relates to a foaming agent for the production of 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]

Conventionally, trichlorofluoromethane (CFC-11) has been mainly used as a foaming agent for producing plastic foams such as polyurethane foam.

However, in recent years, when released into the atmosphere, some CFCs destroy the ozone layer in the stratosphere,
As a result, it has been pointed out that it has a serious adverse effect on the earth's ecosystem including humankind. Therefore, the use and production of CFCs, which have a high risk of depletion of the ozone layer, have been limited by international agreements. The above CFC-11 is subject to 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 an ozone depletion problem.

1,1-dichloro-2,2,2-trifluoroethane (HCFC-123) and 1,1-dichloro-1-fluoroethane (HCFC-141b) are proposed as CFCs having a small influence on the ozone layer. However, since they contain chlorine atoms in their molecules, there is still a risk 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-2-29440 discloses CF ₃ CH ₂ CH ₂
The CF _3, (2) Japanese Patent Laid-Open No. 2-235982 is, CF ₃ CH (CH ₃₎ as a HFC having 3 to 5 carbon atoms CF _3, C
F ₃ CH ₂ CF ₃ and CH ₃ CF ₂ CH ₂ CHF
_2, (3) JP-A-2-265933, the the HFC having 3 carbon atoms, and (4) JP-A-3-746, C ₄ F ₉
H and H (CF ₂ ) ₄ H are proposed respectively.

Although these foaming agents do not have a risk of depleting the ozone layer, they are flammable and may cause a fire.
Since it has poor solubility in polyols, the usable polyols are limited, or the obtained foam has insufficient heat insulating performance, mechanical strength, and the like, there is still room for improvement.

[0008]

DISCLOSURE OF THE INVENTION The present invention has no risk of destroying the ozone layer, is nonflammable, has excellent compatibility with the foam raw material, and has excellent heat insulation properties for the foam obtained.
The main object of the present invention is to provide a foaming agent for producing a plastic foam which can impart mechanical strength and the like, and 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 found that cis-1,1,1,4,4,4-hexafluoro-2- It was found that the above object can be achieved by using butene as a foaming agent.

That is, the present invention is based on cis-1, 1, 1, 4,
The present invention provides a foaming agent for producing a plastic foam, which comprises 4,4-hexafluoro-2-butene.

The present invention also provides cis-1, as a foaming agent.
1,1,4,4,4-hexafluoro-2-butene (c
_{is-CF 3 CH = CHCF 3} ; hereinafter, simply HFC-1
Although described as 336, this name is not intended to include other isomers that might otherwise be included in this nomenclature. ) Is used to provide a method for producing a plastic foam.

The HFC-1336 used in the present invention is
It is a known compound and its production method is also described in the literature (for example, J. Chem. Soc., 1952, 2).
054).

The main physical properties of HFC-1336 are shown in Table 1.

Table 1 Molecular weight 164 Boiling point 33 ° C. Ozone depletion potential 0 The blowing agent of the present invention may be used alone or in combination with other blowing agents or water. Other blowing agents that can be used in combination include, for example, CFC-11, CFC-12 and other low boiling point halogenated hydrocarbons; n-pentane,
Low boiling point hydrocarbons such as isopentane; inert gases and the like.

It is more preferable that these combined substances form an azeotropic composition with the foaming agent of the present invention. For example, HF
C-1336 and n-pentane or isopentane are
The former: the latter = 95-80%: Azeotropic formation is carried out in the composition range of 5-20%.

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,

[0018]

[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. 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.

Examples of the plastic foam produced by using the foaming agent of the present invention include isocyanate, polyethylene, polystyrene, polyvinyl chloride, phenol /
Examples of the foam include a formaldehyde condensate as a raw material. The foam material according to the present invention is suitable for producing a foam made of isocyanate as a raw material, and particularly suitable for producing a polyurethane foam and a polyisocyanurate foam.

The amount of the foaming agent of the present invention used with respect to the plastic as the foaming raw material is the same as that of the known foaming agent. The amount used is appropriately determined depending on the type of foaming raw material, the density of the desired foam, etc., but is usually 1 to 40% as a ratio of the foaming agent to the total of the foaming raw material and the foaming agent.
Degree, 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, when producing a polyurethane foam, an active hydrogen compound having two or more active hydrogen-containing groups such as a polyol and a polyisocyanate compound may be reacted in the presence of a catalyst and a foaming agent according to a conventional method. More specifically, a desired plastic foam can be produced by a known one-step method, prepolymer method, block foaming method, double belt conveyor method, or the like.

In the method for producing a plastic foam according to the present invention, known additives such as a foam stabilizer and a catalyst may 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 and metal compound catalysts such as organic tin compounds, which are used in an amount of about 0.1 to 5% based on the foaming raw material.

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.

[0035]

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

(1) HFC-1336 used in the present invention
Has an ozone depletion coefficient of 0, and there is no danger of depleting the ozone layer.

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

(3) Since the foaming agent of the present invention has good compatibility with the polyol, it is extremely 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 composed of closed cells, it has excellent heat insulating properties, dimensional stability, compressive strength, appearance and uniformity.

[0041]

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

[0042]

Example 1 Compatibility Test 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 (HFC-1336) and 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 mixed with a shaker for 10 minutes.
After shaking for a minute, 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: 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-1336 (%) 20 30 A ○ ○ B ○ ○ C ○ ○ From the results in Table 2, the foaming agent of the present invention shows that the foaming agent of the present invention has a good mixing ratio with the polyol in the mixing ratio actually used. It was confirmed that they were compatible and formed a stable premix.

[0047]

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'-tetra as a catalyst 2 g of methylhexane-1,6-diamine and 16 g of HFC-1336 as a foaming agent according to the present invention were mixed and stirred vigorously. This stirred mixture was mixed with 148 g of crude polymethylene polyphenyl isocyanate to foam,
A rigid polyurethane foam was obtained.

The foaming and foam physical data are shown below in Table 3-A.

Table 3-A Physical Properties HFC-1336 Cream Time (sec) 8 Gel Time (sec) 60 Free Total Density (kg / m ³ ) 26 Compressive Strength (kg / cm ² ) 1.38 Dimensional Stability (-20 ° C, 24 hours (Δ%)) -0.20 Thermal conductivity (kcal / m · hr · ° C) 0.0185 (2) Production of foam using Polyol C Polyol C 100 g, silicone type conditioning Foaming agent 2 g, water 0.2 g, diethyl ethanolamine as a catalyst 1.
5 g, dibutyltin dilaurate 0.15 g and HFC-1336 16 g of the present invention were mixed and stirred vigorously. This stirred mixture and crude tolylene diisocyanate 9
6 g was 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 HFC-1336 Density (kg / m ³ ) 34 Compressive Strength (kg / cm ² ) Parallel 3.15 Vertical 1.15 Dimensional Stability (Δ%) 110 ° C., 7 days +1.4 70 ° C., 95% RH, 7 days +7.5 −20 ° C., 7 days −0.3 The foaming agent of the present invention was evaluated according to the method specified in JIS A 9514.

From the results shown in Tables 3-A and 3-B, by using the foaming agent of the present invention, the heat insulating property,
It was confirmed that a plastic foam excellent in compressive strength and dimensional stability was obtained.

 ─────────────────────────────────────────────────── ─── 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. A foaming agent for producing a plastic foam, which comprises cis-1,1,1,4,4,4-hexafluoro-2-butene. 2. As a foaming agent, cis-1,1,1,4
A method for producing a plastic foam, which comprises using 4,4-hexafluoro-2-butene.