JPH05320308A - Production of flexible polyurethane foam slab - Google Patents

Abstract

PURPOSE:To obtain a flexible polyurethane foam slab excellent in impact resilience, tensile strength, tear strength, etc., according to a one-shot method by using a specific polyisocyanate component, an active hydrogen compound, an additive and water as a foaming agent. CONSTITUTION:The flexible polyurethane foam slab is produced by reacting (A) a polyisocyanate component composed of a mixture of (A1) diphenylmethane diisocyanate (MDI) containing 5-50wt.% total amount of the 2,2'- and 2,4'-isomers with (A2) polymeric MDI having 30-60wt.% di (MDI) content and <=30wt.% total amount of the 2,2'- and 2,4'-isomers in the di at (2.5/7.5) to (8/2) mixing weight ratio of the components (A1)/(A2) with (B) a polyol component composed of an active hydrogen compound (e.g. polyether polyol), water as a foaming agent and an additive (e.g. a catalyst or a foam stabilizer) according to a one- shot method. The amount of the MDI in the mixture is 50-90wt.% and the total amount of the 2,2'- and 2,4'-isomers in the MDI is 5-50wt.% in the polyisocyanate component (A).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a flexible polyurethane foam slab. More specifically, it relates to a method for producing a water-foamable flexible polyurethane foam slab by using diphenylmethane diisocyanate (hereinafter abbreviated as MDI) and polyphenylpolymethylene polyisocyanate (hereinafter abbreviated as polymeric MDI) as polyisocyanate components.

[0002]

2. Description of the Related Art Conventionally, in the production of flexible polyurethane foam slabs, polyisocyanate is either tolylene diisocyanate (hereinafter abbreviated as TDI) or MD
Mixtures of I and polymeric MDI and TDI have been used. However, the high vapor pressure of TDI deteriorates the manufacturing work environment, and therefore improvement has been desired. Also, TD
Initial curing of the I type is slow, and in most cases, heating is required. Therefore, in recent years, attempts have been made to produce a flexible foam using only MDI-based isocyanate without using TDI, and the prescription for molding with a mold (mold) has gradually become known. However, a technique for producing a flexible foam slab using only MDI-based isocine art has not yet been established. In addition, conventional TDI polyurethane foam slabs have used specific CFCs as a foaming agent in order to lower the density and suppress internal heat generation. However, CFCs may also destroy the ozone layer. It is desirable to develop a formulation that does not use it.

[0003]

DISCLOSURE OF THE INVENTION The inventors of the present invention have conducted extensive studies as to a method for producing a flexible polyurethane foam slab using MDI-based isocyanate and water as a foaming agent, and as a result, MDI is used as an isocyanate component.
It has been found that the problem can be solved by using a mixture of the polymer MDI and polymeric MDI, and the present invention has been completed.

[0004]

That is, the present invention provides a method for producing a flexible polyurethane foam slab by reacting a polyisocyanate, an active hydrogen compound, a foaming agent and an additive, in which only water is used as a foaming agent. Used as the polyisocyanate (a) 2,2'- and 2,4 '
MDI and (b) di content (MDI content) 30 to 60% by weight, the sum of the isomers being 5 to 50% by weight,
The total of 2,2'- and 2,4'-isomers in di is 30
It consists of polymeric MDI whose content is less than or equal to wt.
The weight mixing ratio of / (b) is 2.5 / 7.5 to 8/2,
The MDI in the mixture is 50 to 90% by weight,
The total of 2,2'- and 2,4'-isomers in DI is 5
It is a manufacturing method of a flexible polyurethane foam slab, which is characterized by being 50% by weight.

The present invention is a one-shot method using MDI with an active hydrogen compound without prepolymerization. As the polyisocyanate as the isocyanate component of the present invention, a mixture of MDI and polymeric MDI is used. MDI has a total proportion of 2,2'- and 2,4'-isomers of up to 50% by weight. Polymeric MDI
Has a di content (MDI) of 40 to 60% by weight, and the total ratio of 2,2'- and 2,4'-isomers in di is 5 to 5.
It is 30% by weight. The mixing ratio of such MDI (1) and polymeric MDI (2) is (1) / (2) (weight)
Used in the range of 2.5 / 7.5 to 8/2. The amount of MDI in the mixture is 30-85% by weight,
The sum of the ratios of the 2,2'- and 2,4'-isomers in the
~ 50% by weight.

As the active hydrogen compound as the polyol component of the present invention, a polyether polyol or a polyester polyol is used, and the polyether polyol is ethylene glycol, propylene glycol, glycerin,
With a polyhydric alcohol such as trimethylolpropane or a polyvalent amine such as ethylenediamine as an initiator, one or two kinds of monomers such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide or epichlorohydrin are added, and a molecular weight It is a polyether polyol having 4000 to 20000 and a functional number of 2 to 8, and among them, a polyether polyol having a functional number of 3 in which glycerin or trimethylolpropane is used as an initiator and ethylene oxide or propylene oxide is added thereto is used. The polyester polyol is preferably a polyester polyol having a molecular weight of 1,000 to 9000 and a functional group number of 2 to 4 obtained from a dibasic acid and a polyhydric alcohol.

As the additive as the polyol component of the present invention, a foam stabilizer, a surfactant, a viscosity adjusting agent, a flame retardant, a catalyst and the like are used. As the foam stabilizer and the surface active agent, an organic silane compound, polysiloxane, polyoxyalkylene siloxane, and other non-silicone surface active agents such as alkylphenol can be used alone or in combination. The size of bubbles, closed cells, and broken bubbles can be controlled by the amount added. As the viscosity adjusting agent, alkylene carbonate or the like is used. A phosphorus halide compound or the like is used as the flame retardant.

As the catalyst, commonly used amine-based and tin-based organic compounds are used. For example, dimethanolamine, triethylenediamine, N-methylmorpholine, N-methyldicyclohexylamine, dimethylimidazole, 1,8-diazabicyclo [5.4.0] undecene-7, tetramethylpropanediamine, tetramethylhexamethylenediamine, bis. Examples include tertiary amines such as (2-dimethylaminoethyl) ether and dimethylcyclohexylamine, and organic tin compounds such as tin octenoate and dibutyltin dilaurate. Preferred catalysts are amine-based.

Foams can be obtained by foaming these components at an isocyanate index (equivalent ratio of NCO group / active hydrogen group) (hereinafter abbreviated as isocyanate index) of 80 to 105. As the foam, a foam having a low density equivalent to that of a TDI-based foam slab can be obtained.

[0010]

INDUSTRIAL APPLICABILITY The present invention can produce a foam having an equivalent low density as compared with the conventional TDI foam slab, although it does not use CFC. In terms of physical properties, the anti-repulsion elasticity, tensile strength, tear strength, etc., are superior to those of the TDI type.

[0011]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. "Parts" and "%" of the compounding recipes in the examples show "parts by weight" and "% by weight", respectively.

Examples 1 to 14 and Comparative Examples 1 to 2 An isocyanate component consisting of MDI and polymeric MDI and a polyol component consisting of polyether, polyester, a foaming agent and other additives were used in the amounts shown in the table, and the liquid temperature was changed. After adjusting the temperature to 25 ° C, weigh out a predetermined amount and 5000r
The mixture was mixed and stirred at pm for 5 seconds to foam. The formulation and results are shown in the table. Table 1 shows the isocyanate components of Examples 1-5. Table 2 shows the polyol components and formulations of Examples 1-5. Table 3 shows the physical properties of the foam slabs of Examples 1-5. Table 4 shows the isocyanate component and the polyol component of Examples 6 to 10 and their blending. Table 5 shows the physical properties of the foam slabs of Examples 6-10. Table 6 shows the isocyanate component and the polyol component of Examples 11 to 14 and their blending. Table 7
Shows the physical properties of the foam slabs of Examples 11-14. Table 8 shows the isocyanate component and the polyol component of Examples 15 to 16 and their formulations. Table 9 shows the physical properties of the foam slabs of Examples 15-16. Table 10 shows the isocyanate component of Comparative Examples 1 and 2, and Table 11 shows the polyol component and the composition of Comparative Examples 1 and 2.

[0013]

[Table 1] Note 1 in Table 1) Product name Coronate 11 manufactured by Nippon Polyurethane Industry
04, NCO content 31.5%.

[0014]

[Table 2]

Note 1 in Table 2) Sanyo FA703 manufactured by Sanyo Kasei Co., Ltd.
(Functional group number 3, molecular weight 5100, hydroxyl value 33) 2) Polyether Functional group number 2, molecular weight 47
00 3) Tosoh amine catalyst 4) Tosoh amine catalyst

[0016]

[Table 3]

Note 1 in Table 3) According to JIS K6401. 2) Based on JIS K6301. Table 3 shows the isomer ratios of the isocyanates of Formulas A to E in Table 1 and the physical property changes depending on the MDI content.

[0018]

[Table 4]

Note 1 in Table 4) Product name Sannix FA703 manufactured by Sanyo Chemical Industries
(Functional number 3, molecular weight 5100, hydroxyl value 33) 2) Tosoh amine catalyst 3) Tosoh amine catalyst

[0020]

[Table 5] Table 5 shows the results of testing the effect of water used as a blowing agent.

Note 1 in Table 5) According to JIS K6401. 2) Based on JIS K6301. Table 5 shows the isomer ratios of the isocyanates of Formulas A to E in Table 1 and changes in physical properties depending on the MDI content.

[0022]

[Table 6]

Note 1 in Table 6) Nippon Polyurethane Industry Co., Ltd., trade name Nipporan 22
00, hydroxyl value 60 2) Polyether polyol 8 functional Mw = 200
00 3) 〃 Bifunctional Mw = 40
00 4) 〃 Trifunctional Mw = 30
5) Tosoh Amine Catalyst 6) Tosoh Amine Catalyst 7) Nippon Unicar Product Name Silicon L-5340

[0024]

[Table 7]

Note 1 in Table 7) According to JIS K6401. 2) Based on JIS K6301. Table 7 shows the isomer ratios of the isocyanates of Formulas A to E in Table 1 and the physical property changes depending on the MDI content.

[0026]

[Table 8]

Note 8 in Table 8) Nippon Polyurethane Industry Co., Ltd., trade name Nipporan 22
00, hydroxyl value 60 2) Polyether polyol 8 functional Mw = 200
00 3) 〃 Bifunctional Mw = 40
00 4) 〃 Trifunctional Mw = 30
5) Tosoh Amine Catalyst 6) Tosoh Amine Catalyst 7) Nippon Unicar Product Name Silicon L-5340

[0028]

[Table 9]

Note 1 in Table 9) According to JIS K6401. 2) Based on JIS K6301. Table 7 shows the isomer ratios of the isocyanates of Formulas A to E in Table 1 and the physical property changes depending on the MDI content.

[0030]

[Table 10]

[0031]

[Table 11]

Note 1 in Table 11) Product name Sannix FA703 manufactured by Sanyo Kasei Co., Ltd.
(Functional number 3, molecular weight 5100, hydroxyl value 33) 2) Tosoh amine catalyst 3) Tosoh amine catalyst 4) Nippon Unicar brand name Silicon L-5340

In Comparative Example 1, the foam shrank, and a practical product was not obtained. In Comparative Example 2, foaming was remarkable and no foam was obtained.

Claims (1)

[Claims] 1. A method for producing a flexible polyurethane foam slab by reacting a polyisocyanate, an active hydrogen compound, a foaming agent and an additive, as a foaming agent,
Using water, as a polyisocyanate, (a) 2,
Diphenylmethane diisocyanate in which the total of 2'- and 2,4'-isomers is 5 to 50% by weight, and (b) di
Content of 30 to 60% by weight, 2,2'- and 2, in di
Composed of polyphenyl polymethylene polyisocyanate having a total of 4'-isomers of 30% by weight or less, (a) /
The weight mixing ratio of (b) is 2.5 / 7.5 to 8/2, and the diphenylmethane diisocyanate in the mixture is 50 to 9.
0% by weight, and the total amount of 2,2'- and 2,4'-isomers in the diphenylmethane diisocyanate is 5 to 5.
50% by weight of the method for producing a flexible polyurethane foam slab.