JPS61278524A - Production of flame-retarding urethane foam - Google Patents

Abstract

PURPOSE:To obtain the titled foam free of a halogen odor and a risk of decoloration and suitable for, e.g., a heat-insulating material for various industrial materials, by mixing in isocyanate compound with a specified mixed polyol, a phosphate ester as an additive, a catalyst, a foam stabilizer, a blowing agent, etc., and expanding the mixture. CONSTITUTION:The following components are mixed together with expanded: (A) 100pts.wt. mixed polyol comprising 90-97pts.wt. trifunctional polyol such as polyether polyol, 10-3pts.wt. bisphenol A alkylene oxide adduct and, optionally, 1-5wt% (based on total polyol) phosphorus-containing polyol, (B) 5-45pts. wt. phosphate ester (e.g., tricresyl phosphate) as an additive, (C) is isocyanate compound such as tolylene diisocyanate and, optionally, (D) a catalyst such as a tert. amine, (E) a foam stabilizer such as a silicone type and (F) a blowing agent suh as water or methylene chloride, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing a flame-retardant urethane foam suitable for use as a flame insulating material or cushioning material for vehicles, furniture, and various other industrial materials.

(Prior art) Conventional methods for imparting flame retardancy to urethane foam include: ■ Addition of phosphorus-halogen compounds; ■ Combination of halogen-containing compounds and metal oxides such as antimony dioxide and zinc oxide (
Japanese Patent Publication No. 47-21591) (1) Addition of an inorganic compound having water of crystallization such as aluminum oxide or borax is well known.

However, method (2) has the drawback that the low molecular weight phosphorus-halogen compound exists only as a plasticizer in the polymerized polyurethane foam, and therefore it decomposes and evaporates after long-term use, reducing flame retardancy. Furthermore, when thermally welding synthetic resins and fabrics as automotive interior materials, a large amount of halides decomposes and volatilizes, which worsens the working environment due to odors and smoke, and when PVC is used as the synthetic resin, it discolors the PVC. It had the disadvantage of being easy. Furthermore, depending on the type of phosphorus halogen compound, it may reduce the catalytic ability of the urethanization reaction catalyst, so there are restrictions on the amount used, so special care must be taken in selection.

Method (2) is widely used in Japan for cushioning as there is no change in flammability over time; however, since it uses a halogen compound, deterioration of the working environment during heat welding is unavoidable, and the heat weldability In particular, it is unsuitable for the flame lamination method and produces a foam with a hard feel, so there are many restrictions on its use.

Method (2) is the same as method (2) because the flame retardant performance of the crystalline water inorganic alone is low, so if a high degree of flame retardancy is required for automobiles, furniture, etc., it is necessary to use a halogen compound in combination. The drawbacks of the above-mentioned prior art were unavoidable. (Problems that Ring attempts to solve) The present application overcomes all the drawbacks of the prior art mentioned above.

Manufacture of urethane foam that can be used in a wide range of applications such as frame laminates, cushions, and insulation, and has excellent flame retardancy that complies with FMVSS Section 302, the flame retardant standard of the U.S. automobile safety standards. The purpose is to provide a method.

(Means for Solving the Problems) As a result of extensive research into halogen-incompatible flame retardant means from all angles, the inventors of the present application found that alkylene oxide of bisphenol A is included in a general-purpose trifunctional polyol as a polyol component. Mixing 3 to 10% by weight of an adduct,
And by using phosphoric acid ester in a range of 5 to 45 parts by weight based on 100 parts by weight of the mixed polyol,
It has been found that the flame retardant standard of FMVSS Section 302 can be satisfied.

As the trifunctional polyol used in this application, all known polyether polyols or polyester polyols can be used, and these can also be used in combination. In addition, as long as it is trifunctional, a polyol such as a phosphorus-containing polyol can also be used in combination. However, the amount of the phosphorus-containing polyol used in combination is preferably in the range of 1 to 5% by weight based on the total polyol, and even if the amount of the phosphorus-containing polyol used in combination is increased to 5% by weight or more, it will not contribute to the effect of improving flame retardancy. The alkylene oxide adduct of bisphenol A used in this application is bisphenol A
That is, it is obtained by reacting 2 or more moles of alkylene oxide with 1 mole of 2,2-bis(4-hydroxyphenyl)propane, but ethylene oxide or propylene oxide is generally used as the alkylene oxide, and commercially available products include Toho Chiba Co., Ltd. Chemistry Exhibition BISOL-2
Corresponding to this are Niepole BP, Niepole BP, and Niepole BPE manufactured by Sanyo Chemical Industries. The amount of the alkylene oxide adduct of bisphenol A is in the range of 3 to 10 parts by weight based on 90 to 97 parts by weight of the trifunctional polyol.
If it is less than 10 parts by weight, the flame retardant effect will be poor, and if it is more than 10 parts by weight, the closed cell content of the foam will increase, making it impossible to obtain a good foam. In systems where the above-mentioned phosphorus-containing polyol is used in combination, unless the total amount of the phosphorus-containing polyol and the alkylene oxide adduct of bisphenol A is 10% by weight or less in the trifunctional polyol, the foam will still form closed cells. Please be careful as this can easily occur.

Phosphate esters used as additives include trimethyl phosphate and triethyl phosphate.

Tributyl phosphate, trioctyl phosphate,
Tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate.

Trixylenyl phosphate, xylenyl diphenyl phosphate, talesyl diphenyl phosphate, octyldiphenyl phosphate, triaryl phosphate, etc. can be used alone or in combination. The amount of phosphoric acid ester added is in the range of 5 to 45 parts by weight per 100 parts by weight of the mixed polyol, and if it is less than 5 parts by weight, even if the proportion of the phosphorus-containing polyol in the mixed polyol is increased.

A foam with good flame retardancy cannot be obtained, and when 45 parts by weight or more is added, compression set properties are significantly reduced.

Good form cannot be obtained. Furthermore, bisphenol A
Although the alkylene oxide adduct generally has poor compatibility with trifunctional polyols, a homogeneous mixed system can be easily obtained by using the above-mentioned phosphoric acid ester in combination.

In this application, there are no particular restrictions on the catalysts, foam stabilizers, and blowing agents used; tertiary amines and organometallic compounds are used as catalysts, silicone foam stabilizers are used as foam stabilizers, and foam stabilizers are used as blowing agents. All known compounds such as water, freon, methylene chloride, and other inert low-boiling hydrocarbon compounds can be used.

In addition, organic or inorganic fillers and reinforcing materials may be used as necessary.
or colorants, known non-halogen flame retardants such as antimony dioxide and aluminum hydroxide.

Alternatively, low molecular weight glycols or chain extenders may be added.

All known isocyanate compounds used in this application can be used, including general-purpose tolylene diisocyanate,
In addition to diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, metaxylene diisocyanate, polymethylene polyphenylisocyanate, or modified products thereof, etc. are used alone or in combination.

(Example) Examples 1 to 7 Three times the amount of each compound shown in Table 1 was used in a conventional manner.
A foam was created by free foaming in a 0x30x30C1l metal container, then heated at 100°C for 10 minutes, and then left at room temperature for 24 hours to mature.FMVSS 3
The burning distance and burning time of the foam were measured according to the combustion test method specified in Section 02, and the apparent density was measured according to the method of ASTM 01564-64. The results are also listed at the bottom of Table 1.

In addition, flame retardancy is judged if the fire is extinguished up to the first marked line placed at a distance of 38fflI11 from the end of the specimen, then it passes regardless of the burning speed, and combustion continues beyond the first marked line. In this case, a case where the burning rate was about 8 am/m/m was judged to be acceptable.

Comparative Examples 1 to 3 The foam was subjected to a combustion test and the apparent density was measured in the same manner as in the examples, except that only the blending ratio of polyol and the blending amount of phosphoric ester were outside the scope of the claims of the present application.The results were as follows: It is shown in Table 2.

(Blank below) (Effects of the invention) ■ An alkylene oxide adduct of bisphenol A, which was developed for the purpose of improving the heat resistance of rigid polyurethane, is mixed with a trifunctional polyol in a range of 3 to 10% by weight, and phosphoric acid By blending the ester in a range of 5 to 45 parts by weight with respect to 100 parts by weight of the mixed polyol,
It complies with the flame retardancy stipulated in FMVSS Section 302 and does not use halogen compounds, so there is no risk of halogen odor occurring when heat fused with fabric or synthetic resin, and there is no disadvantage of discoloring PVC leather. A flame retardant foam can be obtained.

■Generally, alkylene oxide adducts of bisphenol A have poor compatibility with trifunctional polyols and tend to separate into two layers even if mixed as is. However, phosphoric acid esters, which are highly compatible with trifunctional polyols, By mixing them, it is possible to obtain the effect that they can be used in a trifunctional polyol system without any problems, and this can be said to be a practically useful technique.

Claims (1)

[Claims] In producing polyurethane foam, a mixed polyol consisting of 90 to 97 parts by weight of a trifunctional polyol and 3 to 10 parts by weight of an alkylene oxide adduct of bisphenol A is used as a polyol component, and 5 to 5 parts by weight of a phosphoric acid ester is used as an additive. A method for producing flame-retardant urethane foam, characterized in that it is used in combination in a range of 45 parts by weight.