JPH0126606B2 - - Google Patents

Description

[Detailed description of the invention]

"Industrial Application Field" The present invention relates to a method for producing urethane foam. Specifically, by using a polyhydroxy compound as a raw material in combination with specific compounds, it is possible to produce urethane foam with excellent heat resistance, flame retardancy, and low smoke emission. The present invention relates to a method for manufacturing urethane foam. Urethane foam is obtained in the process of polyurethane bond formation by reaction of polyisocyanate and polyhydroxy compound in the presence of a blowing agent, and is used for various purposes. In particular, when polyurethane foam is used for applications such as building materials, it is required to have various physical properties such as heat resistance, flame retardance, and low smoke emission. Heat resistance refers to the property of not causing thermal deformation such as shrinkage due to heat, low smoke emitting property refers to the property of producing a small amount of smoke when burned, and flame retardancy refers to the property of not causing thermal deformation such as shrinkage due to heat. These properties are mutually independent and important physical properties. ``Prior Art'' Various methods have been proposed to impart these properties to urethane foam. For example, flame retardation, particularly a highly flame retardant method, involves adding soluble iron compounds to the foam. A method of adding a silicone surfactant to the foam is known (Japanese Patent Application Laid-Open No. 53-72098), and in order to reduce smoke generation, 5% (by weight) of silicone surfactant is added to the foam.
It is also known to add more than
409). In addition to these methods, various modification methods have been proposed, but each method aims to maintain flame retardancy and reduce the brittleness of the foam, and each has its own advantages and disadvantages, and is still insufficient. It is not yet possible to achieve the desired effect. "Problems to be Solved by the Invention" The inventors of the present invention have conducted further intensive studies on the above-mentioned method in order to produce a urethane foam with better physical properties that combine heat resistance, flame retardance, and low smoke emission. As a result, various polyhydroxy compounds are used as raw materials for manufacturing urethane foam, but by using a specific polyhydroxy compound in combination with a specific additive, iron compounds soluble in the manufacturing solution can be used. The present invention was completed based on the novel finding that it is possible to produce a foam with excellent heat resistance and low smoke emission without impairing the flame retardant effect exhibited by the flame retardant effect. "Means for Solving the Problem" The object of the present invention is to provide a urethane foam that is excellent in heat resistance, flame retardancy, and low smoke emission. When manufacturing polyurethane foam using as the main manufacturing raw material, the polyhydroxy compound is derived from at least one aromatic compound selected from the group consisting of aromatic polyhydric carboxylic acids, carboxylic acid anhydrides, and carboxylic acid esters. 3% by weight or more of an aromatic polyester polyol, and 3% by weight of an organosilicon surfactant selected from an organopolysiloxane-polyoxyalkylene copolymer or a polyalkenylsiloxane having a polyoxyalkylene side chain. This can be easily achieved by using the above method and adding 0.05 to 10% (by weight) of a soluble iron compound to the production stock solution in terms of iron element. Hereinafter, the present invention will be explained in detail, and in this specification, weight % means the proportion in the production stock solution. An iron compound that is soluble in the production stock solution used in the method of the present invention is defined as an iron compound that dissolves at least 0.05% by weight in terms of iron when added to the production stock solution in which the reaction raw material and the blowing agent are mixed before foaming. Representative examples of these compounds include dicyclopentadienyl iron, mono- and di-lower alkyl (1 to 8 carbon atoms) dicyclopentadienyl iron,
For example, ethyldicyclopentadienyl iron, n-
Examples include dicyclopentadienyl iron compounds such as butyldicyclopentadienyl iron, di-n-butyldicyclopentadienyl iron, iron acetylacetonate, iron phthalocyanine compounds, iron chloride, etc., but other iron salts, Even iron coordination compounds are effective as long as they are soluble in the manufacturing solution. Among these, those that dissolve all of the added amount are more efficient. In addition, the production stock solution in this application means the production stock solution before foaming, which contains all raw materials such as polyisocyanate, polyhydroxy compound, blowing agent, catalyst added as necessary, foam stabilizer, and other auxiliary agents. . If the amount of iron compound added is too large, there is a problem that the inside of the foam will be burned (scorch occurs) immediately after foaming, and if it is too small, the flame retardant effect will be low. Therefore, the range of iron compounds is 0.05 to 0.05 of the foam manufacturing stock solution in terms of iron element.
10% by weight (the following percentages are by weight unless otherwise specified)
), and is preferably in the range of 0.35 to 7%, more preferably 0.5 to 5%. The organosilicon surfactant used in the present invention is selected from those widely used as surfactants for urethane foam, and specifically, organopolysiloxane-polyoxyalkylene copolymer, polyoxyalkylene side chain polyalkenyl siloquine having the following. Regarding the manufacturing method, chemical structure, and specific compound examples of these organosilicon surfactants, see, for example, Japanese Patent Publication No. 35-10543, Japanese Patent Publication No. 36-13344, and Japanese Patent Publication No. 37-1989.
8850, Tokuko Shou 38-6000, Tokuko Sho 39-1850, Tokuko Sho
40-12190, Special Publication Showa 42-2719, Special Publication Showa 43-16399,
It is described in Special Publication No. 43-17998, etc. The amount of organosilicon surfactant added according to the invention is considerably higher than the amounts normally used in the production of urethane or isocyanurate foams, preferably 3% by weight or more, preferably 4 to 20% by weight.
%, more preferably from the range of 5 to 10%. The isocyanate compound used in the present invention is an organic compound in which two or more NCO groups are bonded within the same molecule, and includes aliphatic and aromatic polyisocyanate monomers, mixtures thereof, etc. Contains modified products. Examples of the aliphatic polyisocyanate sheet include hexamethylene diisocyanate sheet, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and the like. Examples of aromatic polyisocyanates include tolylene diisocyanate (2,4 and 2,6-
isomer), diphenylmethane diisocyanate,
Vitolylene diisocyanate, naphthylene diisocyanate (e.g. 1,5-naphthylene diisocyanate), polynuclear polyisocyanate (so-called crude,
MDI or polymeric isocyanate), etc. Further, the aromatic polyester polyol used in the present invention is usually synthesized by a condensation reaction between an aromatic polycarboxylic acid, an ester thereof, or an acid anhydride thereof, and a polyol having a primary hydroxyl group. As aromatic carboxylic acids and their derivatives,
For example, phthalic acid, trimellitic acid, pyromellitic acid, and their esters and acid anhydrides can be mentioned. Examples of the polyol having a primary hydroxyl group to be reacted with an aromatic carboxylic acid include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, trimethylolpropane, and hexanediol. The polyester polyol used in the present invention is obtained by condensing one or more of the above carboxylic acids and polyols, and the hydroxyl value of these polyester polyols is usually 200 to 600 mg.
About KOH/g is preferable. The compositional content (amount used) of this polyester polyol is 3 to 36%, preferably 5 to 20%, and if it is less than 3%, it is difficult to obtain the specified heat resistance and flame retardancy, and if it is less than 36% In the above cases, the equivalence ratio (isocyanate index) decreases and the compatibility decreases, resulting in poor heat resistance, flame retardancy, etc.
This is not very preferable because it may cause disadvantages in terms of physical properties. When producing the foam according to the present invention, a urethanization catalyst and a blowing agent are used, and these are appropriately selected from those used in the production of ordinary urethane foams. As a urethanization catalyst, triethylamine,
N, N', N'-tris (dimethylaminopropyl)
Tertiary amines such as hexahydrotriazine, 2,4,6-tris(dimethylaminomethyl)phenol, tetramethylethylenediamine, diazabicycloalkene; tertiary amines, ethyl alcohol, mono-N-substituted carbonate Examples of using co-catalysts such as acid esters; tertiary phosphines;
Examples include carboxylic acid metal salts such as potassium acetate. In addition, as a blowing agent, a low boiling point inert organic solvent that evaporates due to the heat of reaction generated during foam generation, such as trichloromonofluoromethane, dichlorofluoromethane, dichloromonofluoromethane, hexane, etc., is used, but other isocyanin Compounds that react with carbonate to generate carbon dioxide, such as water, compounds containing water of crystallization, nitroalkanoic acid amides, or compounds that generate gas by thermal decomposition due to the heat of reaction during foam formation, such as sodium bicarbonate. etc. can also be used. In the present invention, since a large amount of organosilicon-based surfactant is used as a smoke suppressant, there is no need to add various kinds of surfactants, but in some cases, it is necessary to add various kinds of surfactants to help homogenize the reaction mixture. Other types of nonionic surfactants, anionic surfactants,
It is also possible to add a cationic surfactant. In the present invention, various additives may be further added as necessary, and examples of additives include phosphorus- and halogen-containing organic compounds, halogen-containing resins,
Additive flame retardants such as antimony oxide and aluminum hydroxide, colored powders such as pigments and dyes, talc,
Examples include diatomaceous earth, inorganic powders such as graphite, short glass fibers, and other inorganic fillers. Various methods are known for producing isocyanurate ring-containing urethane foams, but these can be roughly divided into: (a) adding a trimerization catalyst, blowing agent, surfactant, etc. to organic polyisocyanate; Method of stirring and foaming. (b) A method for producing a modified isocyanurate ring-containing urethane foam, that is, a foaming method similar to the above, in which a modifier is reacted with a polynuclear polyisocyanate in advance to foam the modified polyisocyanate (prepolymer method). (c) a polyol containing an isocyanerate ring;
A foaming method using a polyisocyanate, a blowing agent, a surfactant, and a urethanization catalyst. can be mentioned. The method of the present invention can be applied to any of the methods (a), (b), and (c), but in order to achieve the purpose of the present invention, Among the methods, it is particularly advantageous to carry out the reaction using polyisocyanates modified with small amounts of modifiers. In addition, as the modifier for the modified isocyanurate ring-containing foam in the method (b) above, polyether polyols, polyester polyols, polyepoxides, polycarbon acids, oils and fats having hydroxy end groups, liquid dienes having hydroxy end groups are used. Polymers and phenolic resin initial condensates (phenols, novolacs) are known. Japanese patents regarding the manufacturing method of these various modified isocyanurate ring-containing urethane foams and trimerization catalysts are described in "Plastic Materials" Vol. 16, No. 1 (1975), p. 56. "Effects of the Invention" As detailed above, the foam obtained by the method of the present invention has excellent heat resistance and flame retardancy, and is also low smoke emitting, so it can be used in a wider range of formulations and is effective as a quasi-nonflammable material. It not only has excellent fire prevention performance (JIS A 1301) as an exterior wall material. In particular, the present invention has remarkable effects on composite building materials with iron plates, ceramic materials, aluminum, steel foil, real cement, gypsum boards, and the like. Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. Examples 1 to 2 and Comparative Examples 1 to 3 Polyisocyanates, aromatic polyester polyols, aliphatic polyether polyols, silicone surfactants, trimerization catalysts, flame retardants, ferrocene, and blowing agents were used to prepare polyisocyanates as shown below. An isocyanurate foam was produced. Table 1 shows the blending ratio and the physical properties of the obtained foam. The physical properties of the foam have the following meanings. Raw material polyisocyanate: PAPI-135 (Product name: Polymethylene-polyphenylene-polyisocyanate, NCO equivalent 135, manufactured by Kasei Upjiyon Co., Ltd.) Fragrance polyester polyol: Terate-202
(Product name: OH equivalent 127.5, manufactured by Hercules)
Terate−203 (Product name: OH equivalent 178, Hercules
(Manufactured by Toray Silicone Co., Ltd.) Lipidic polyether polyol: GP-250 (Product name: Sanyo Kasei Co., Ltd.) Silicone surfactant: SH-193 (Product name: Toray Silicone Co., Ltd.) Trimerization catalyst: Crithane-51 (Product name: Flame retardant: Ferrocene (reagent) Foaming agent: R-11E (trichloromonofluoromethane) "Foam properties" Smoke-emitting property: Expressed by JIS A1321 smoke-emitting coefficient CA. Heat resistance: Qualitatively judge items harmful to fire prevention such as deformation and cracks according to JIS A1321. It is expressed as the temperature at which 30% weight loss occurs using a thermobalance. Flame retardancy: Based on JIS K7201's oxygen index method for flame testing of polymer materials. To produce the foam, a mixture of PAPI-135 and other components such as polyol and a blowing agent was thoroughly mixed and the two liquids were combined at the time of foaming and rapidly stirred to cause foaming.

[Table] Examples 3 to 7 Foams were produced by varying the amounts of silicone surfactant and iron compound added. Table 2 shows the mixing ratio of raw materials and the physical properties of the obtained foam.

【table】

[Table] Comparative Example 4 Examples 1 to 2 except that aliphatic polyester polyol (Isonol-11 (trade name, manufactured by Upjiyon Co., Ltd.), OH equivalent 234) was used as the polyhydroxy compound, and no iron compound was added. A foam was manufactured in the same manner as above. Table 3 shows the blending ratio of raw materials and the physical properties of the obtained foam. Comparative Examples 5 to 7 Aromatic polyether polyol (BPX-11 (trade name, Asahi Denka Kogyo Co., Ltd.) was used as the polyhydroxy compound.
Example 1 except that the silicone surfactant and the amount of iron compound added were changed.
A foam was produced in the same manner as in 2. Table 3 for raw material blending ratio and obtained foam physical properties
Shown below.

【table】

[Table] Comparative Examples 8 to 9 Foams were produced in the same manner as in Example 1, except that the amount of polyhydroxy compound or organosilicon surfactant added was changed. Table 4 shows the blending ratio of raw materials and the physical properties of the obtained foam.

【table】

[Table] Use

Claims (1)

[Scope of Claims] 1. When producing polyurethane foam using polyisocyanates and polyhydroxy compounds as main raw materials, the polyhydroxy compounds include a group consisting of aromatic polyhydric carboxylic acids, carboxylic acid anhydrides, and carboxylic acid esters. 3% by weight or more of an aromatic polyester polyol derived from at least one aromatic compound selected from the following, and an organopolysiloxane-polyoxyalkylene copolymer or a polyalkenylsiloxane having a polyoxyalkylene side chain. Flame retardant, heat resistant and A method for producing polyurethane foam with excellent low smoke emission. 2. The method for producing a polyurethane foam according to claim 1, wherein the ratio of the aromatic polyester polyol to the organosilicon surfactant is 20/1 to 1/7. 3. Claim 1 or 2, characterized in that the NCO/OH (equivalent ratio) of polyisocyanate and polyhydroxy compound in the raw materials is 1.5 or more.
2. Method for producing polyurethane foam as described in Section 1.