JP2994446B2 - Manufacturing method of rigid polyurethane foam - Google Patents

Description

The present invention relates to a method for producing a rigid polyurethane foam,
More specifically, the present invention relates to a method for producing a rigid polyurethane foam having excellent heat insulating properties, dimensional stability and compressive strength by using dichlorotrifluoroethane or dichlorofluoroethane as a foaming agent.

(Prior Art) Conventionally, as a method for producing a rigid polyurethane foam having excellent heat insulating properties, a method using trichlorofluoromethane (hereinafter abbreviated as CFC-11) as a foaming agent is known. However, CFC-11 (CFC-11) is one of the causes of ozone layer depletion, which is a problem as environmental destruction.
) Are being implemented and eliminated. Therefore, dichlorotrifluoroethane (hereinafter abbreviated as HCFC-123) and dichlorofluoroethane (hereinafter abbreviated as HCFC-141b), which are referred to as alternative freons, are CFC-1
It is considered a leading alternative to 1.

However, HCFC-123, HCFC-141b is used as a foaming agent, and as a polyol, propylene glycol, trimethylolpropane, glycerin, ethylenediamine,
When a polyether polyol using tolylenediamine, pentaerythritol, methylglucoside, sorbitol, sucrose, or the like as an initiator, a conventional CFC-1 is used.
Compared to foam foamed using 1, foaming efficiency is much slower at the beginning, b) foaming efficiency is reduced, c) dimensional stability, compressive strength, thermal conductivity, etc. are significantly reduced. Problems arise. Also, when a bifunctional aromatic polyester polyol composed of an aliphatic polyester polyol such as lactone and a bifunctional alcohol and an aromatic dicarboxylic acid is used, satisfactory foam physical properties cannot be obtained.

(Problems to be Solved by the Invention) An object of the present invention is to produce a rigid polyurethane foam without impairing excellent heat insulating properties, compressive strength and dimensional stability even when HCFC-123 and HCFC-141b are used as a foaming agent. It is to provide a way to do it.

(Means for Solving the Problems) The present invention relates to a method for producing a rigid polyurethane foam using at least an isocyanate component, a polyol component and a foaming agent, wherein a polyol containing a polyhydric alcohol having a functionality of 2 or more as a polyol component and a polyol having a functionality of 3 or more are used. A polyfunctional aromatic polyester polyol having an average number of functional groups of substantially 2 or more obtained from the aromatic polyfunctional carboxylic acid is used in an amount of 5% by weight or more in a polyol component, and dichlorotrifluoroethane or dichlorofluoroethane is used as a blowing agent The present invention relates to a method for producing a rigid polyurethane foam.

In the present invention, as the isocyanate component, various known polyfunctional aliphatic, aliphatic and aromatic isocyanates can be used. For example, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 4,4-
Dicyclohexylmethane diisocyanate (HMDI), 2,
4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), 4,4-diphenylmethane diisocyanate (MDI), ortho toluidine diisocyanate (TODI), naphthylene diisocyanate (NDI), xylylene diisocyanate (XDI), lysine diisocyanate (LDI) and the like.

In the present invention, examples of the bifunctional or higher polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, butanediol, neopentyl glycol, hexamethylene glycol, dipropylene glycol, trimethylene glycol, trimethylolpropane, glycerin, pentaerythritol, And sorbitol and the like. Examples of the trifunctional or higher-functional aromatic polyfunctional carboxylic acid include trimellitic acid, pyromellitic acid and anhydrides or esters thereof.

In the present invention, 5% by weight or more, preferably 10 to 90% by weight of the polyol containing the polyol containing the polyhydric alcohol having 2 or more functional groups and the polyfunctional aromatic polyester polyol obtained from the aromatic polyfunctional carboxylic acid having 3 or more functional groups in the polyol component. %
use. It is possible to use a common polyol in addition to the above specific polyol, such polyols include various known hard urethane polyether polyols,
Polyester polyols and other polyols can be used. Examples of polyether polyols include propylene glycol, trimethylolpropane, glycerin, ethylenediamine, tolylenediamine, pentaerythritol, methyl glucoside, sorbitol, polyether polyols having sucrose and the like as initiators, and polyester polyols such as adipine Acids, suberic acid, sebacic acid, brassic acid, etc.
An aliphatic dicarboxylic acid, terephthalic acid, isophthalic acid or the like as an acid component, and an ether such as an aliphatic diol having 1 to 6 carbon atoms such as ethylene glycol, propylene glycol, neopentyl glycol, and hexamethylene glycol, diethylene glycol, and dipropylene glycol; Glycols, spiroglycols, polyester polyols or polycaprolactone polyols containing N-alkyl dialkanolamine such as N-methyldiethanolamine as a polyol component, and the like, specific examples of which include polyethylene adipate polyol and polybutylene adipate polyol , Adipate polyols such as polyethylene propylene adipate polyol, terephthalic acid polyols (eg, Toyobo,
Examples thereof include trade names such as Byron RUX and Byron RV-200L) and polycaprolactone polyols (eg, Daicel Chemical, trade names Placcel 212 and Placcel 220).

Next, in the present invention, in addition to the above components, a chain extender, a foam stabilizer, a catalyst, a flame retardant, a plasticizer, and the like can be added as necessary.

The production of the rigid polyurethane foam of the present invention can be carried out according to a generally known method.

(Examples) Hereinafter, examples and comparative examples will be described.

Examples 1 to 6 and Comparative Examples 1 to 8 Hard polyurethane foams were obtained using the components shown in Table 1. That is, first, a liquid mixture shown in Table 1 was prepared, rapidly mixed with crude diphenylmethane diisocyanate, immediately poured into a vertical mold having a size of 200 × 200 × 150 mm, and free-foamed to produce a hard polyurethane foam. . Table 1 shows the properties of the obtained foam. The dimensional stability was measured by measuring the dimensional change when stored at 25 ° C. for 48 hours.
However, the measurement direction is perpendicular to the foaming direction. The details of each component in the table are as follows.

C-MDI (MR-200): Nippon Polyurethane, crude diphenylmethane diisocyanate, NCO (%) 31% Polyol A: Polyester polyol synthesized from diethylene glycol and trimellitic acid, Hydroxyl value 300 mg KOH / g Polyol B: Diethylene glycol and pyromellitite Polyester polyol synthesized from acid, hydroxyl value 350 mgKOH / g GR-31A: Polyether polyol with hydroxyl value 385 mgKOH / g obtained by adding propylene dioxide to tolylenediamine manufactured by Takeda Pharmaceutical SU-450: Mitsui Toatsu Chemicals, Inc. Proxel 305: Polyester polyol having a hydroxyl value of 450 mg KOH / g produced by adding propylene oxide to sucrose manufactured by Daicel Chemical Co., Ltd. Polyester polyol produced by Daicel Chemical Industries, Ltd., ring-opening polymer of ε-caperolactone, hydroxyl value 340 mg KOH / g APP- 315: Union Carbide made cyclic carboxylic acid and die Polyester polyol synthesized from tylene glycol, hydroxyl value 300mgKOH / g Foam stabilizer: SH193 manufactured by Toray Silicon Co., Ltd. Catalyst: KAO No. 1 foaming agent manufactured by Kao Corporation HCFC-123: Dichlorotrim manufactured by Asahi Glass Co., Ltd. Fluoroethane HCFC-141b: Dichlorofluoroethane manufactured by Daikin Industries, Ltd. CFC-11: Trichlorofluoromethane manufactured by Mitsui DuPont Fluorochemicals Co., Ltd. Examples 7 to 12 and Comparative Examples 9 to 16 Each described in Table 2 A hard polyurethane foam was obtained in the same manner as in Example 1 except that the components were used. The results are also shown in Table 2.

(Effects of the Invention) According to the method of the present invention, even when HCFC-123 or HCFC-141b is used as a foaming agent, a rigid polyurethane foam is produced without impairing excellent heat insulating properties, compressive strength and dimensional stability. be able to.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Riichi Nishida 5-7 Nishinakajo-cho, Ibaraki-shi, Osaka Inside Toyo Gum Industry Co., Ltd. (72) Inventor Hiroyuki Anzai Inamicho, Kako-gun, Hyogo 1176 Uchigaike, 6/1 character Toyo Tire & Rubber Co., Ltd. Hyogo Works Hyogo Factory (56) References JP-A-1-225614 (JP, A) JP-A-3-20319 (JP, A) JP-A 3-47822 (JP, A) JP-A-3-195718 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08G 18/42 C08J 9/14

Claims (1)

(57) [Claims] 1. A method for producing a rigid polyurethane foam using at least an isocyanate component, a polyol component and a foaming agent, wherein a polyol containing a dihydric or higher functional alcohol as a polyol component and a trifunctional or higher aromatic polyfunctional carboxylic acid are used. Characterized in that a polyfunctional aromatic polyester polyol having an average number of functional groups of substantially 2 or more obtained from the polyol component is used in an amount of 5% by weight or more in a polyol component, and dichlorotrifluoroethane or dichlorofluoroethane is used as a foaming agent. Manufacturing method of polyurethane foam.