JPH0610238B2 - Method for producing flame-retardant polyurethane foam capable of flame lamination - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a flame-retardant flexible polyurethane foam, and more particularly to a flame-retardant flexible polyurethane capable of being frame-laminated with other materials such as cloth and leather. It relates to a method of manufacturing a foam.

(Prior Art) Flexible polyurethane foam is a material with a cushioning property that is bonded to other materials such as fabric or leather, and has a good feel and a sense of volume, such as cushioning material for automobile seats and ceiling materials, It has been widely used as an upholstery material for sofas and beds for furniture.

As a method for pasting the conventional flexible polyurethane foam with other materials, a method using an adhesive or a method of melting the surface of the flexible polyurethane foam by a high-frequency welder or a flame and directly bonding it to a fabric has been proposed. There is. In particular, fusion bonding by flame, so-called frame laminating method (lamination) uses the adhesiveness of the polyurethane foam itself, so no drying step is required, and the adhesion speed is fast and efficient. It is also a method that has been industrially established and widely generalized as a means for bonding a flexible polyurethane foam and another sheet-like material.

By the way, in the flexible polyurethane foam itself used for this frame termination, various physical properties are required depending on its intended use. For example, in the United States, a urethane laminate material as an interior material for automobiles is FMVSS- Flame retardance that complies with Section 302 (US Federal Motor Vehicle Safety Standards) is required, so various studies have been conducted on the flame retardancy of soft polyurethanes, and the flame retardancy achieved by laminating various flame retardant foams and fabrics to date. Laminate materials have been developed.

For example, polyester-based urethane foams with halogenated phosphates as flame retardants to make them flame-retardant, or foams using polyether polyols that have uniquely improved flame lamination characteristics. Some flame retardants contain a reactive phosphorus- or halogen-containing compound (JP-A-58-19321).

(Problems to be Solved by the Invention) However, in these various foams described above, there is a drawback that the cloth or the foam of the laminate material is discolored or the foam itself is deteriorated. For example, the laminated material is 1 at 100 ° C in a closed system.
When the accelerated heating test is performed for about 50 to 200 hours, thermal discoloration of the fabric and thermal deterioration of the foam are noticeable, and it is not always sufficient in terms of heat resistance and thermal aging stability. Had.

In particular, in the case of automobile interior materials, after production, there is a tendency that they are left for a long period of time under the hot sun in a sealed state with windows closed, and therefore, production of flexible polyurethane foam having excellent heat resistance and thermal aging stability. Was desired. In addition, as described above, since the automobile interior material is required to have flame retardancy particularly conforming to FMVSS-302, it has been desired to develop a more excellent foam material.

(Means for Solving Problems) By the way, it is considered that the deterioration phenomenon of the flame-retardant foam for laminating is mainly dependent on the flame retardant used, and recently, phosphoric acid containing no chlorine atom is used as the flame retardant. Although the ones using only the esters have been proposed, the satisfactory ones have not yet been obtained.

Therefore, in addition to the aromatic phosphoric acid esters used as the flame retardant, the present inventors have prepared a bromine-containing prepolymer having a terminal isocyanate group obtained by reacting a bromine-containing compound having active hydrogen with a polyisocyanate. When used together in a specific blending ratio, a silicone-based surfactant is present as a foam stabilizer, and a specific polyol is combined with this and mixed with an organic isocyanate for foaming polymerization, excellent lamination properties, flame retardancy, and heat resistance. The inventors have newly found that a flexible polyurethane foam having particularly good thermal aging stability can be produced, and 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 and other additives, i) a polyfunctional polyester ether polyol 60 to 10 is used as a polyol component. Parts by weight and a polyol consisting of 40 to 90 parts by weight of polyoxypropylene polyol having a trifunctional molecular weight of 2000 to 5000, and ii) 3 to 30 parts by weight of an aromatic phosphate compound as a flame retardant, And 2 to 10 parts by weight of a bromine-containing prepolymer having a terminal isocyanate group obtained by reacting a bromine-containing compound having an active hydrogen with a polyisocyanate is added in an amount of 2 to 10 parts by weight as a content of the bromine-containing compound having an active hydrogen, iii) a foam stabilizer As a silicone surfactant 0.5 to 5 Characterized in that it contains an amount unit, is to provide a method for producing a flame lamination possible flame retardant flexible polyurethane foams.

(Function) In this case, the polyfunctional polyester ether polyol used as a part of the polyol component is preferably 2
To trifunctional polyester ether polyols.

This type of polyester ether polyol is, for example, as disclosed in Japanese Patent Publication No. Sho 48-10078, a flexible polyurethane foam produced by using this is one which is easily melted by heat and has excellent frame laminating characteristics. And, for example, the general formula for the molecular skeleton: (In the formula, R represents a saturated aliphatic or aromatic polycarboxylic acid residue, A represents a ring-opened residue of a compound having a cyclic ether group, l is an average number larger than 1, and m is 0 or 1. A) and a polyol having a structure in which a chain composed of a polyester bond represented by the formula (3) is blocked by a polyether compound.

However, in the method for producing a flexible polyurethane foam of the present invention, the polyester ether polyol of this kind is not used alone, but by using other commonly used polyether polyol in combination, a flame of a certain standard or more is obtained. It has been newly found that the laminating property can be secured, and it is possible to solve various drawbacks when the above polyester-ether polyol is used alone.

The polyether polyol to be used in combination is a polyol for general flexible polyurethane foam, for example, polyoxypropylene polyol having a substantially trifunctional molecular weight of 2000 to 5000 obtained by addition-polymerizing propylene oxide with glycerin as an initiator. Can be mentioned. By using this polyoxypropylene polyol in combination, it is possible to improve the mechanical properties and cushioning properties of the resulting polyurethane foam.

The combined ratio of the polyfunctional polyester ether polyol and the polyoxypropylene polyol can be arbitrarily selected within the range of 60 to 10 parts by weight: 40 to 90 parts by weight. This combination ratio depends on the desired physical properties of the polyurethane foam to be used, but when the polyester ether polyol exceeds 60 parts by weight, the viscosity of the polyol becomes high and the workability during foam production deteriorates. Although the heat-sealing property of the obtained foam is improved, the compression residual strain of the foam is large and so-called "settling" is also large, and the practicality as a cushion material becomes poor. Further, if the amount is less than 10 parts by weight, frame lamination can be performed, but the so-called initial adhesiveness immediately after laminating may be inferior, and the product is apt to partially float or peel off, so that the object of the present invention cannot be achieved. Will be things.

In the production of the frame-laminatable flexible polyurethane foam of the present invention, an organic polyisocyanate component and a polyol component based on the above-mentioned specific combination are foam-polymerized in the presence of a foaming agent. It is characterized in that it contains a specific additive together for imparting flammability and heat resistance.

That is, in the present invention, a bromine-containing prepolymer having a terminal isocyanate group obtained by reacting a polyisocyanate with a bromine-containing compound having an aromatic phosphate compound and active hydrogen as a flame retardant as described above is used in combination, A silicone-based surfactant as a foam stabilizer is combined with this and contained.

In this case, the aromatic phosphate compound used as the flame retardant together with the prepolymer not only achieves flame retardancy of the foam but also has the property of improving the fusion property. Aromatic phosphate compounds that can be used include, but are not limited to, triphenyl phosphate, tricresyl phosphate, octyl diphenyl phosphate, cresyl diphenyl phosphate, trixylenyl phosphate, triaryl phosphate ester, and the like. Not something.

On the other hand, the prepolymer used in combination with the aromatic phosphate compound as the flame retardant is a bromine-containing prepolymer having a terminal isocyanate group obtained by reacting a bromine-containing compound having active hydrogen with a polyisocyanate. It is also possible to use a bromine-containing compound having active hydrogen in the powder state together with an aromatic phosphoric acid ester compound for a similar purpose as a flame retardant, which has already been filed by the present inventors. However, in the present invention, a bromine-containing compound having active hydrogen in a powder state is not particularly used, and the compatibility with the above-mentioned specific polyol is remarkably increased. A bromine-containing prepolymer having an isocyanate group) is used.

The bromine-containing compound having active hydrogen that constitutes this prepolymer prevents reduction in flame retardancy due to volatilization and outflow of the flame retardant, not only imparts high flame retardancy, but also improves heat resistance of the resulting foam. In addition, it has the effect of increasing the thermal stability over time.

Examples of such a bromine-containing compound having active hydrogen include dibromoneopentyl glycol, tetrabromobisphenol A, 2,2-bis (4-hydroxyethoxy-3,5-dibromophenyl) propane, and the like. As the polyisocyanate forming the prepolymer with the bromine-containing compound having active hydrogen, 2,4- or 2,6-tolylene diisocyanate, hexamethylene diisocyanate, naphthalene diisocyanate, diphenylmethane diisocyanate, or a mixture thereof can be used.

In the present invention, an aromatic phosphoric acid ester compound and a bromine-containing prepolymer having a terminal isocyanate group are used together as a flame retardant. However, the content of this aromatic phosphoric acid ester compound may be other combined additives. However, it is preferably 3 to 30 parts by weight, though it varies depending on the content of If it is less than 3 parts by weight, the improvement of flame retardancy cannot be obtained.
On the other hand, if the amount exceeds 30 parts by weight, the flame retardancy and the fusion property are no longer improved, and the physical properties of the obtained foam, particularly the hardness, are lowered, which is not preferable.

On the other hand, the content of the bromine-containing prepolymer having a terminal isocyanate group depends on the amount of the aromatic phosphate compound used, but the content of the bromine-containing compound having an active hydrogen is preferably 2 to 10 parts by weight.

The silicone-based surfactant added as a foam stabilizer is preferably a flame-retardant and high-elasticity silicone, and more preferably a surfactant generally called a low-activity silicone. However, any silicone foam stabilizer that can achieve good urethane foam foaming without any problem may be used, and is not limited to the above. Examples of such silicone-based surfactants include L-5710, L
-5720 (Nippon Unicar Co., Ltd.), F-203, F
-242T, F-258, F-606 (manufactured by Shin-Etsu Silicone Co., Ltd.), B-8202, B-8612 (manufactured by Gold Schmidt) and the like, and the content thereof is 0.5 to 5.
Parts by weight.

Incidentally, other components in the present invention, that is, the organic polyisocyanate, may be those conventionally used for producing a flexible polyurethane foam, further dyes, pigments, plasticizers used for general urethane foam foaming, A foaming agent, a bulking agent and the like can be added.

In addition, in the production of the flexible polyurethane foam capable of lamination 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 mixed stepwise. Further, as foaming, any of slab foaming, mold foaming, spray foaming and the like can be applied.

Thus, in the method of the present invention, a prepolymer of an aromatic phosphoric acid ester compound and a bromine-containing compound having active hydrogen is used in combination as a flame retardant, and a silicone surfactant is combined as a foam stabilizer in the method. And complying with FMVSS-302 standard by including these additives in a specific polyol,
Flexible polyurethane foams with 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 has a thickness of 11
mm, length 3000 mm, width 1400 mm, flame temperature 1000
The surface was melted at a temperature of about ° C, and flame-laminated by laminating with flame-retardant polyester / polyamide 80/20 fabric and press-bonding to obtain a foam-fabric laminated material. This product was similarly subjected to the combustion test and heat resistance test, and the results are also shown in the table.

Each test method was based on the following.

Density: JISK6401 Combustion test of flexible polyurethane foam: FMVSS-302 Item Combustion test of laminate material: FMVSS-302 Heat resistance test of laminate material: Put 10 × 60 × 80mm laminated parts piece in 300ml glass bottle, seal, It was heated at 100 ° C. for 200 hours and visually observed.

(Effects of the Invention) As is clear from the above results, the flexible polyurethane foam of the present invention can favorably perform frame lamination with a fabric or the like, and the obtained laminate material is F
Provide a good laminate material which has flame retardancy conforming to the standard of MVSS-302, is excellent in heat resistance and thermal stability over time, and is free from any thermal discoloration or thermal deterioration of fabric or foam. Is.

Moreover, since an inexpensive polyoxypropylene polyol is used together as one component of the polyol, there is an advantage that the cost can be reduced.

Further, since the flame retardancy is synergistically improved by the combination of the specific flame retardants, the amount of the flame retardant used may be small.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C08G 18/48 NEA 8620-4J C08J 9/02 CFF 9268-4F C08K 5/523 7242-4J C08L 75 / 04 NGD 8620-4J // (C08G 18/08 101: 00) C08L 75:04 8620-4J

Claims (4)

[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 and other additives, i) 60 to 10 parts by weight of a polyfunctional polyester ether polyol as a polyol component. Parts and a polyol consisting of 40 to 90 parts by weight of polyoxypropylene polyol having a molecular weight of 2,000 to 5,000 which is substantially trifunctional, ii) 3 to 30 parts by weight of an aromatic phosphate compound as a flame retardant, and 2 to 10 parts by weight of a bromine-containing prepolymer having an isocyanate terminal group, which is obtained by reacting a bromine-containing compound having active hydrogen with a polyisocyanate, is compounded in an amount of 2 to 10 parts by weight as a bromine-containing compound having active hydrogen. Iii) As a foam stabilizer , 0.5 to 5 parts by weight of silicone surfactant A method for producing a flame-retardant flexible polyurethane foam capable of frame lamination, which comprises: 2. The method according to claim 1, wherein the polyfunctional polyester ether polyol is a bifunctional or trifunctional polyester ether polyol. 3. A bromine-containing compound having active hydrogen is dibromoneopentyl glycol.
Item 2. The method according to item 2 or item 2. 4. The method according to any one of claims 1 to 3, wherein the silicone-based surfactant is for flame retardancy.