JPS58152014A - Production of rigid polyurethane foam - Google Patents

Abstract

PURPOSE:A polyol resulting from addition reaction of alkylene oxide to a mixture containing diaminotoluene and a compound with active hydrogens at a specific ratio is used to produce the titled foam with high scorching resistance and little humid-heat deterioration. CONSTITUTION:The addition polymerization of (A) an alkylene oxide, preferably ethylene oxide to a mixture consisting of (B) 20-40pts.wt. of 2,4-diaminotoluene and/or 2,6-diaminotoluene, (C) 20-40pts. of 2,3-diaminotoluene and/or 3,4-diaminotoluene and (D) 60-20pts.wt. of a compound bearing 2-4 active hydrogens such as ethylene glycol is effected and the resultant polyol is used as a polyether polyol to effect the reaction with (E) an organic polyisocyanate in the presence of a catalyst, a foaming agent and a foaming regulator to give the objective foam.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing rigid polyurethane foam using a novel polyether polyol (hereinafter simply referred to as the "new polyol").

Conventionally, polyethers for rigid polyurethane foams include sucrose, sorbitol, pentaerythritol, glycerin, ethylenediamine, etc. with alkylene oxide added thereto.

These polyethers have poor compatibility with polyisocyanates and hyphthalones, and it often occurs that good 7 ohms cannot be obtained. To improve this, polyethers using aromatic diamines such as diaminodiphenylmethane have been used.

Among them, polyether obtained by adding propylene oxide to a mixture of 2,4-diaminotoluene and 2,6-diaminotoluene, which is commonly used, has good compatibility with polyisocyanates and chlorofluorocarbons. Although a foam with fine cells can be produced, the disadvantage is that the viscosity is very high, making workability poor, and the cost of raw materials is high.

Furthermore, the polyol obtained by adding alkylene oxide to a mixture of 2,3-diaminotoluene and 3,4-diaminotoluene has a high viscosity and poor compatibility with CFC blowing agents, and when injected into panels etc. Since the liquid spreads poorly, it is necessary to increase the amount of injection, and the resulting foam has disadvantages such as high fryability and rapid deterioration under moist heat and high temperature. Furthermore, when ethylene oxide was added to increase the hydroxyl value and ethylene oxide was added to lower the viscosity, there were problems such as scorch formation inside the foam and the inclusion of minute cracks.

The present inventors conducted various studies in view of these drawbacks, and as a result, arrived at the present invention.

That is, the present invention is as follows.

2,4-diaminotoluene and/or 2 as an organic polyethyl polyol in the presence of a catalyst, a blowing agent, and a foam stabilizer.
・6-diaminotoluene 20-4o is a hydroxyl group obtained by addition polymerizing alkylene oxide to a mixture consisting of 20-40 parts by weight of 3,4-diaminotoluene and 60-20 parts by weight of a compound having 2 to 4 active hydrogen atoms. A method for producing a rigid polyurethane foam, characterized by using a polyol having a value of 300 to 550.

The weight ratio of the total amount of diaminotoluene used in the present invention to the compound having active hydrogen is 4 0/6 0 to 8
0/20 is preferred. If the blending ratio of diaminotoluene is less than 40/60, the compatibility of the new polyol with crude diphenylmethane diisocyanate (hereinafter referred to as crude MDI) will be poor9 and the liquid spread will be poor. Moreover, if this ratio is 80/20 or more, the viscosity of the polyol becomes high, which deteriorates the workability, and also increases flyability and increases the demolding time of the molded foam.

The amount of 2,4- and/or 2,6-diaminotoluene and 2
- The ratio with the amount of 3- and/or 3,4-diaminotoluene is 20/40 to 40/20.

Preferably it is 40/60 to 60/40. If this ratio is smaller than 20/40, scorch will not easily occur when producing urethane foam.
If this ratio is greater than 4 0/2 0, the viscosity of the polyol increases, resulting in a decrease in workability and an increase in price.

Examples of compounds having 2 to 4 active hydrogen atoms used in the present invention include water, polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, trimethylolpropane, and pentaerythritol, monoethanolamine, diglobanolamine, and triethanol. These include alkanolamines such as amines and ethylenediamine.

In the present invention-c, ethylene oxide (hereinafter simply referred to as EO) and propylene oxide (hereinafter referred to as PO) are usually used as alkylene oxides (hereinafter, when these oxides are collectively referred to as alkylene oxide), EO It is preferable to use it because it reduces the viscosity of the polyol and improves the elongation of the liquid.

Although the method and order of addition of the alkylene oxide are not limited, preferably, the alkylene oxide is added to the base material without a catalyst, and then the alkylene oxide is further added after the addition of a catalyst, and the hydroxyl group of the target polyether is added. Regarding the addition of values of 300 to 550E, there is no particular restriction on the addition position and method of addition! Preferably, EO and PO are added into an alkylene oxide solution which is added without a catalyst, and either block addition or random addition of EO and PO may be performed.

If the hydroxyl value of the present invention is lower than 300, the obtained foam will shrink at low temperatures, and if it is higher than 550, the viscosity of poly-13ol will increase and scorch will easily occur. Bo-13 isocyanate is used when producing polyurethane foam that is harder than polyether.

Although there is no limitation as it is a conventionally known method, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, isomer ratio (weight ratio) of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate. ) is 80
/2 0,6 5/3 5 mixture.

Crude tolylene diisocyanate, 4-4'-diphenylmethane diisocyanate, conventionally known modified 4-4'-diphenylmethane diisocyanate modified with carbodiimide, etc., crude diphenylmethane diisocyanate,!
・5-S7 ethylene diisocyanate, 0-, Itl- or tiP-xylylene diisocyanate, hexamethylene diisocyanate, etc., dimers and trikeids of these, as well as some of these polyisocyanates, with known low molecules. These may be modified with polyols or known polyethers, and may be used alone or in combination.

The amount of polyisocyanate used is NCO/H (active hydrogen)
is 0.7 to 1.4 (equivalent ratio).

As the foaming aid, a foaming catalyst 1, a foaming agent, and a foam stabilizer are used. As blowing catalysts, conventionally known amine compounds, organic tin compounds, etc. are used, and as blowing agents,
Water, trichloromonofluoromethane, dichlorodifluoromethane, dichlorotetrafluoroethane, monochlorodifluoromethane, methylene chloride, etc. are used. As the foam stabilizer, a conventionally known silicone foam stabilizer is used.

When obtaining a rigid polyurethane foam from the polyether of the present invention, foaming can be carried out by the Wang 7117) method, the prepolymer method or the semi-prepolymer method.

The polyether of the present invention has relatively low viscosity, good liquid flowability, good resistance to chlorofluorocarbons and polyisocyanates, flyability of less than 4, and good physical properties with little heat deterioration or deterioration at high temperatures. You can get the following.

The polyether of the present invention will be specifically described as a hard polyurethane in a wide range of fields such as electric refrigerators, freezers, cold storage boxes, cold and heat insulation materials for construction, sound absorbing materials, synthetic wood, and structural materials. The invention is not limited to these in any way (hereinafter, X indicates weight X).

Production Example 1 2.3- and 3.4-diaminotoluene mixture (hereinafter referred to as o
-TDA) 3.5kF, 2.4- and 2.6-diaminotoluene mixture (hereinafter referred to as m-TDA)
3.5 kf1) Reethanolamine 3.0 kf was put into a reaction vessel, and the mixture was heated and melted to form a nine-sided mixture.

First add 66.5kf to PO, then 66.6kf to EO.
kf was added. Next, add 0.4% caustic potash to the small amount.
After adding KP and raising the reaction temperature to 110°C,
O was added at 149.5 kF. After the reaction was completed, it was neutralized with phosphoric acid, the precipitated crystals were filtered, and the filtrate was used as a product. The obtained polyol (1) had a hydroxyl value of 403 and a viscosity of 4600.
cps/25°C.

Production Example 2 The same base as in Production Example 1 was placed in a reaction vessel, and after melting, first E
6.81 kf for O, then 6 for PO, 67 kf? Then, after adding 0.2 weight
Polyol (2) with cps/25°C was obtained.

Production example 3 m-TDA3.5kf, o-TDA3-5kSF,
) Add 6.11 kF of EO and 7.8 kF of PO to a mixture of 3.0 kF of reethanolamine in the same manner as in Production Example 1.
0kW was added. After adding 0.2% caustic potash.

Added po to 5.0kF, hydroxyl value 540, viscosity 14
A polyol (3) of 600 cps/25°C was obtained.

Production Example 4 9.84kf of PO and 5.21k of EO were added to a mixture of 3.5kf of m-TDA, 4.5kf of o-TDA and 2.0kf of triethanolamine in the same manner as in Production Example 1.
Added F. After death, add 0.3% caustic potash to increase PO to 15.2? added, hydroxyl value 401, viscosity 6800c
A polyol of ps/25°C was obtained.

Production Example 5 6.32 kf of PO, 1 EO, and 4.92 kF were added to a mixture of 4.5 kf of m-TDA, 2-5 kf of o-TDA, and 3.Okf of glycerin in the same manner as in Production Example 1. Caustic power! 41. with addition of jO,2X. PO to 20.
Added 4kf, hydroxyl value 405, viscosity 12500c
A polyol (5) having a temperature of ps/25°C was obtained.

Production example 6 m-TDA 3-5kS', o-TDA3.5kF,
2.52 kF of EO and 8.84 kF of PO were added to the mixture of glycerin 3.OkF in the same manner as in Production Example 1.

After adding caustic potash 0.2X, po was 19,33k
Add f, hydroxyl value 420, viscosity 9200 cps/
Polyol (6) at 25°C was obtained.

Comparative Production Example 1 o-TDA 7-OkF, ) Reethanolamine/
3.0kW of the mixture was added in the same manner as in Production Example 1.

5 and 1 kf were added. After adding 0.2% of caustic potash, 17.74 kf of PO was added and the hydroxyl value was 45.
0 and a viscosity of 8000 cps/25° C. (Comparative 1) was obtained.

Comparative production example 2 o-TDAlokF was heated to 80°C, and EO was 7.21
After the reaction, it was treated in the same manner as in Production Example 1, and the hydroxyl value was 410.
, a polyol with a viscosity of 8,200 cps/25°C (broiled in Hichu).

Examples 1 to 6 and Comparative Examples 1 and 2 500f each of polyols (1) to (6) and (Comparison 1) to (Comparison 2) produced as described above were taken, and PO was added to the lactose sugar and amine mixture. Hydroxyl value 450 obtained by adding
Each was mixed with 500 tons of polyol having a viscosity of 4000 cps/25°C. Trischloroethylphosphor) (TCE) was added to these polyol mixtures in the amounts shown in Table 1.
P) Flame retardant, water, tetramethylhexanediamine (TM
HD) catalyst, silicone foam stabilizer, Freon-11 blowing agent and crude diphenylmethane diisocyanate) (MDI-CR
) were mixed sequentially.

Also, the thickness is 30 mm, the width is 35 Q fnffl >-
The above mixed stock solution 330f was injected into the bottom of the vertical surface of an inverted panel having a side length of 500 mm. After the stock solution foams within the panel and rises within the vertical plane of the panel.

It spread and hardened in the horizontal plane. The elongation of the liquid was compared depending on the distance traveled by this form.

Separately, a box measuring 400 mm in length, 200 mm in width, and 400 mm in height was heated to 45° C., and the above mixed stock solution was poured into it to cause foaming. The foamed and cured foam was allowed to stand overnight, then cut at the center, and the degree of scorch in the foam core was examined.

The liquid elongation and scorch conditions of each mixed stock solution are shown in Table 1, and it is clear that the present invention is superior in terms of liquid elongation and scorch. [Th':1'1) Procedural amendment (voluntary) May 79, 1980 Haruki Shimada, Commissioner of the Patent Office 1. Indication of the case Patent application 1987-33975 2. Name of the invention Method for manufacturing rigid polyurethane foam 3. Relationship with the case of the person making the amendment Patent applicant telephone: 593-7915 4. Column 5 of “Claims” and “Detailed Description of the Invention” of the specification to be amended, Contents of the amendment (1) ) Percentage of claims As per attached sheet (2) Page 3, lines 15-16, "20-40 parts by weight" is corrected to "20-45 parts by weight."

(3) On page 3, line 17, "20-40 parts by weight" is corrected to "20-45 parts by weight."

(4) Page 3, lines 18-19, "60-20 parts by weight" is corrected to "60-10 parts by weight."

(5) Page 4, line 5 Correct 1'-80/20J to r90/IOJ.

(6) Page 4, line 9 “Correct 80/20J to r90/10.J.

(7) Page 4, line 15 [Correct 20/40 to 40/20J to r20/45 to 45/20J.

(8) Page 4, line 16 r40/60 to 60/40J is corrected to ``30/45 to 40/20 J.

(9) Page 4, line 17 1'-20/40 J is corrected as "20/45 J.

QO page 4, line 19 [Correct 40/20J to [45/20J.]

Attachment above: Claims (after correction) In producing a rigid polyurethane foam by reacting an organic polyisocyanate with an active hydrogen-containing compound in the presence of a catalyst, a blowing agent, and a foam stabilizer, 2 as a polyether polyol is used.・20 to 45 parts by weight of 4-diaminotoluene and/or 2,6-reamittoluene, 20 to 4 parts by weight of 2,3-diaminotoluene and/or 3,4-diaminotoluene
Compound 60 having 5 parts by weight and 2 to 4 active hydrogen atoms
Method 8 for producing rigid polyurethane foam, characterized by using a polyol having a hydroxyl value of 300 to 550 obtained by addition polymerizing alkylene oxide to a mixture consisting of ~10 parts by weight

Claims (1)

[Claims] 1. 2,4-diaminotoluene and/or 2 as a polyether polyol in the production of a rigid urethane foam by organic polymerization in the presence of a catalyst, a blowing agent, and a foam stabilizer. - Consisting of 20 to 40 parts by weight of 6-reamittol, 20 to 40 parts by weight of 2,3-diaminotoluene and/or 3,4-diaminotoluene, and 60 to 20 parts by weight of a compound having 2 to 4 active hydrogen atoms. Hydroxyl value 30 obtained by addition polymerizing alkylene oxide to the mixture
Rigid polyurethane foam [[.