JPH0774258B2 - Method for producing flame-retardant polyurethane foam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to cushioning materials such as cushioning skin materials and ceiling materials for automobile seats, sofa upholstery materials for furniture, bed upholstery materials, and cloth materials and leather. The present invention relates to a method for producing a flame-retardant flexible polyurethane foam that can be frame-laminated with a skin material as a cushioning composite material obtained by laminating skin materials such as.

(Prior art) In recent years, flexible polyurethane foam and other sheet materials such as cloth and leather have been used as cushioning materials, and have been used widely as interior materials and furniture for automobiles as a skin material with a good feel and volume. Has been done.

As a method of bonding, there are a method of using an adhesive and a method of heat-melting the surface of the flexible polyurethane foam by a high-frequency welder or a flame to directly adhere it to a cloth or the like, but in particular, fusion bonding by flame, so-called frame lamination Since the method (frame lamination) does not require a drying step and has a high adhesion speed and is an efficient method, the method for laminating flexible polyurethane foam and other sheet-like materials is widely used as an industrially established method. ing.

On the other hand, urethane laminate materials for automobile interior materials are required to have flame retardancy conforming to MVSS-302 in the United States, and flexible polyurethane foams are flame retarded, and various laminate materials with flame retardant foams are used. Being developed.

For example, polyester-based urethane foams made flame-retardant by using halogenated phosphates as flame retardants, and foams made of polyether polyols with improved flame lamination characteristics are used as reactive flame-retardant phosphorus. Alternatively, some use a halogen-containing compound.

(Problems to be Solved by the Invention) However, it has been found that any of these types of foams has the drawback that the fabric or foam of the laminate material is discolored or deteriorated over a long period of time. The material under certain conditions (eg, 100-110 ° C in a closed system)
When a heating acceleration test was performed for 150 to 300 hours), discoloration of the fabric and deterioration of the foam were observed, and there was a problem that it was not always sufficient in terms of heat resistance and stability over time. is there.

Particularly in the case of automobile interior materials, after production, there is often a tendency to be left for a long time in the hot sun in a sealed state with the window closed, so that it is possible to produce a flexible polyurethane foam having excellent heat resistance and stability over time. It was wanted. In addition to the above, in the interior materials for automobiles as described above,
In particular, since it is required to have flame retardancy that conforms to MVSS-302, it has been desired to develop a more excellent foam material.

In view of these requirements, the present invention is capable of frame lamination, has flame retardance that complies with MVSS-302, and is heat resistant without discoloration or deterioration of the laminated material even under the above-mentioned certain practically effective conditions. It is intended to provide a flexible polyurethane foam having good properties.

(Means for Solving Problems) By the way, the deterioration phenomenon of the flame-retardant foam for laminating described above is mainly used as a flame retardant, and is considered to depend on a halogen compound. Flame-retardant foams using only reel phosphate compounds have also been proposed (JP-A-60-112836).
(Japanese Patent Application Laid-Open No. 60-123539), however, is not yet satisfactory.

Therefore, the present inventors have used 5 to 40 parts by weight of an aromatic phosphoric acid ester compound as a flame retardant, diols having a specific molecular weight as a crosslinking agent, and 3 parts by weight of a nitrogen-containing compound having an active hydrogen group as an amine catalyst. If the following three are used in combination, and a specific frame-laminatable polyol is combined with it and foam-polymerized with an organic polyisocyanate, it is excellent in laminate properties, flame retardancy, heat resistance, and has particularly good stability over time. The inventors have found that polyurethane foam can be produced, and have completed the present invention.

That is, according to the present invention, when a flexible polyurethane foam is produced by foaming and polymerizing an organic polyisocyanate and a polyol in the presence of a foaming agent, a catalyst, a foam stabilizer, and other additives, 1) a polyester ether polyol as a polyol component Used alone or in combination with a polyester ether polyol and another polyol; 2) 5 to 40 parts by weight of an aromatic phosphoric acid ester compound as a flame retardant, relative to 100 parts by weight of the above polyol; 3) as a crosslinking agent Flame retardant flexible polyurethane capable of flame lamination, characterized by containing 5 parts by weight or less of diols having a molecular weight of 1000 or less; and 4) 3 parts by weight or less of a nitrogen-containing compound having an active hydrogen group as an amine-based catalyst. It is a method of manufacturing a foam.

In this case, as the polyol capable of flame lamination, a polyfunctional polyester ether polyol or the like can be used, and preferably a bifunctional or bifunctional polyester ether polyol.

This type of polyester ether polyol is, for example, as disclosed in Japanese Examined Patent Publication No. Sho 48-10078, a flexible polyurethane foam produced using this is one that is easily melted by heat and has excellent frame laminating characteristics. And has, for example, the general formula: CO—R—COO—A—O ₁ CO—R—COO _m H (wherein R is a saturated aliphatic or aromatic polycarboxylic acid residue, and A is a cyclic ether group. The compound represents a ring-opened residue, 1 is an average number larger than 1, and m is 0 or 1.) is a polyol having a structure in which a chain composed of a polyester bond is blocked by a polyether compound.

In the present invention, even if the polyester ether polyol is not used alone, it is possible to use one which is capable of imparting a frame laminating property of a certain standard or more by using in combination with another commonly used polyether polyol. The polypropylene glycol adduct having 2 to 4 functional groups to be used in combination is a polypropylene glycol having a molecular weight of about 1000 to 6000, which is used for general flexible polyurethane foam, and can change the mechanical properties and cushioning properties of the foam as desired. At the same time, since this type of polyol is inexpensive, it is possible to reduce the overall cost of the polyol.

The combined ratio of the polyfunctional polyester ether polyol and the polyoxypropylene polyol can be arbitrarily selected within the range of 70 to 10 parts by weight: 30 to 90 parts by weight.

This combination ratio depends on the desired physical properties of the intended polyurethane foam, but when the polyester ether polyol exceeds 70 parts by weight, the viscosity of the polyol becomes high and handling becomes difficult, and the compression residual strain of the obtained foam is It becomes large and becomes less practical as a cushion material. On the other hand, if the amount is less than 10 parts by weight, the desired frame laminating property does not reach a certain standard, and the object of the present invention cannot be achieved.

In the production of the frame-laminable flexible polyurethane foam of the present invention, the organic polyisocyanate component and the polyol component based on the specific combination described above are foamed and polymerized in the presence of a foaming agent, a foam stabilizer and the like, It is characterized in that it contains a specific additive in combination for imparting frame laminate characteristics, heat resistance and flame retardancy.

That is, in the present invention, as described above, a polyester ether polyol is used as an aromatic phosphate compound as a flame retardant, a diol having a molecular weight of 1000 or less as a crosslinking agent, and a nitrogen-containing compound having an active hydrogen group as an amine-based catalyst. It is contained in combination.

In this case, the aromatic phosphate compound as a flame retardant not only achieves flame retardancy of the foam, but also has the property of improving heat resistance. Examples of aromatic phosphate compounds that can be used include triphenyl phosphate, tricresyl phosphate, octyl diphenyl phosphate, cresyl diphenyl phosphate, trixylenyl phosphate, and the like.

The content of this aromatic phosphate compound varies depending on the content of other additives used in combination, but is 5 to 40 parts by weight, preferably 10 to 30 parts by weight. If it is less than 5 parts by weight, flame retardant performance is difficult to obtain, and if it exceeds 40 parts by weight, improvement in flame retardant performance is no longer observed, and the physical properties of the resulting foam, particularly mechanical strength such as elongation, etc. This is because not only is it unfavorable because it becomes low, but also the cost increases.

The diols having a molecular weight of 1000 or less contained as a cross-linking agent have the effect of changing the molecular arrangement by changing the structure of the molecular skeleton of the foam (polymer), and as a result, improving the frame lamination characteristics. The aromatic phosphate compound in the foam can control the heat resistance of the foam (polymer) up to around a temperature at which the flame-retardant action can be sufficiently exhibited when heated, and as a result, it is useful for flame-retarding the foam. Is.

Examples of the diols of this kind include ethylene glycol, diethylene glycol, propylene glycol, butylene glycols, neopentyl glycol, triethylene glycol, polyethylene glycols, polypropylene glycols, and bisphenol A. The content in this case depends on the amount of the aromatic phosphate ester compound used, but is preferably 5 parts by weight or less. This is because if the amount exceeds 5 parts by weight, the number of closed cells in the foam increases and the range of the catalyst becomes extremely narrow, resulting in lack of foaming stability.

Examples of the amine-based catalyst that can be used in the present invention include nitrogen-containing compounds having an active hydrogen group. Conventionally used highly sublimable amine-based catalysts cause discoloration of laminated composite materials such as PVC leather and metal corrosion at high temperatures. This is because the nitrogen-containing compound having an active hydrogen group reacts with the free polyisocyanate during foaming and does not cause sublimation of the amine-based catalyst even when the foam is exposed to high temperatures.

Examples of the nitrogen-containing compound having an active hydrogen group that can be used in the present invention include dimethylaminoethanol, dimethylaminoethoxyethanol, N, N, N'-trimethylaminoethylethanolamine, N, N, N'-trimethylaminopropylethanolamine. 1,3-bis (N, N-
Dimethylamino-2-propanol, N, N, N ',
N "tetramethyl N"-(2-hydroxy) ethyltriethylenediamine, N, N, N ', N "-tetramethyl-N"-(2-hydroxy) propyltriethylenediamine, N, N-bis (3-dimethyl) Aminopropyl) aminoethanol, N, N-bis (3-dimethylaminopropyl) amino-2-propanol, N-methyl-N '
(2-Hydroxyethyl) piperazine, N-methyl-
N '-(2-hydroxypropyl) piperazine, N-
Examples include (2-hydroxyethyl) morpholine and 3- (dimethylamino) propylamine carbonate.

If the amine catalyst having an active hydrogen group exceeds 3 parts by weight, the amount of heat generated during foaming of the urethane foam increases and the foam becomes burnt (scorch), lacks stability during foaming, and has low foam elongation. It is not preferable because it causes deterioration of physical properties.

The other components in the present invention, that is, the organic polyisocyanate and the foam stabilizer may be those conventionally used for producing a flexible polyurethane foam, and further commonly used dyes, pigments, plasticizers, and foaming agents. Agents, extenders and the like can also be added.

Further, in the production of the flexible flexible polyurethane foam of the present invention, there is no particular limitation on the mixing order of each component, and all components may be mixed at the same time or may be stepwise mixed.

Thus, in the method for producing a flexible polyurethane foam capable of lamination according to the present invention, an aromatic phosphate ester as a flame retardant is used in place of the halogen compound-phosphate ester compound as a flame retardant that has been conventionally used. The compound is used alone, and a molecular weight of 1000 is used as a cross-linking agent.
A combination of the following diols and nitrogen-containing compounds having an active hydrogen group as an amine-based catalyst, and by incorporating such an additive in a specific polyol, it meets the specifications of MVSS-302 and is excellent. Flexible polyurethane foams having excellent laminating properties are produced.

(Example) Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Flexible polyurethane foams were produced based on the formulations shown in Table 1.

A combustion test was performed on the obtained flexible polyurethane foam, and the results are also shown in the table.

Also, each flexible polyurethane foam is 11mm thick
Sheet, the surface of which is melted under a flame temperature of 900 ° C, and polyester / polyamide 80/20 with a basis weight of 470 g / m ²
The fabric and the non-woven fabric were overlaid and pressure-bonded for frame lamination to obtain a fabric / foam / non-woven laminate material. This product was similarly subjected to a combustion test and a heat resistance test, and the results are also shown in the table. Each test method was based on the following.

Density; JIS K-6401 Flame retardant performance test of flexible polyurethane foam; MVSS-302 Item Flame retardant performance test of laminated material; MVSS-302 Item Heat resistance performance test of laminated material; Cut into 10 x 50 x 100 mm in 500 ml wide-mouth glass bottle Put 4 pieces of stapler (made by Max Co., Ltd.) on the four corners of the laminated component piece, seal, and heat at 100 ° C for 200 hours,
The discoloration of the skin material and the degree of rust on the stapler were visually observed.

(Effects of the Invention) As is clear from the above results, the effects obtained by the present invention are as follows.

(1) Flexible polyurethane foam is MVSS by itself.
-Flame retardant performance that meets the standards of -302 is obtained.

(2) The flexible polyurethane foam can favorably perform frame lamination with a cloth or the like.

(3) The obtained laminated material has a flame-retardant performance that complies with the standards of MVSS-302.

(4) The laminated material is excellent in heat resistance and stability over time.

(5) A good laminate material in which thermal discoloration or deterioration of the fabric or foam is hardly observed.

Also, there is no metal corrosion such as stapler.

In addition to the characteristics as described above, there is an advantage that the cost can be reduced because an inexpensive polyoxypropylene polyol is used together as one component of the polyol.

Further, since the flame retardant performance is synergistically improved by using a combination of specific additives without using the halogen-based compound flame retardant, the amount of the flame retardant used may be small.

 ─────────────────────────────────────────────────── --Continued from the front page (56) Reference JP-A-52-147698 (JP, A) JP-A-61-278524 (JP, A) JP-A-61-34011 (JP, A) JP-A-61- 236812 (JP, A) JP 61-275349 (JP, A)

Claims (2)

[Claims] 1. When producing a flexible polyurethane foam by foaming and polymerizing an organic polyisocyanate and a polyol in the presence of a foaming agent, a catalyst, a foam stabilizer, and other additives, 1) a polyester ether polyol as a polyol component. Used alone or in combination with a polyester ether polyol and another polyol; 2) 5 to 40 parts by weight of an aromatic phosphoric acid ester compound as a flame retardant, relative to 100 parts by weight of the above polyol; 3) as a crosslinking agent Flame retardant flexible polyurethane capable of flame lamination, characterized by containing 5 parts by weight or less of diols having a molecular weight of 1000 or less; and 4) 3 parts by weight or less of a nitrogen-containing compound having an active hydrogen group as an amine-based catalyst. Form manufacturing method. 2. The method for producing flame-retardant flexible polyurethane foam capable of frame lamination according to claim 1, wherein the polyester ether polyol is a bifunctional or trifunctional polyester ether polyol.