JPH05186624A - Urethane prepolymer composition - Google Patents

Abstract

PURPOSE:To provide the subject composition having a flame-retardant function by adding a nitroso foaming agent, an azo foaming agent, etc., to a specific urethane prepolymer. CONSTITUTION:The objective composition comprises (A) 100 pts.wt. of an urethane prepolymer having 0.5-5wt.% of isocyanate groups at the molecular ends, (B) 0.1-5.0 pts.wt. of one or more of a nitroso foaming agent (e.g. dinitropentamethylenetetramine), an azo foaming agent (e.g. azobisisobutyronitrile) and an inorganic compound (e.g. aluminum hydroxide, active carbon), (C) 0.1-5.0 pts.wt. of a foam stabilizer, (D) 0.1-10 pts.wt. of a chlorinated paraffin and, if necessary, a plasticizer, a thixotropy-imparting agent, etc.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a urethane prepolymer composition, more specifically, a flame-retardant function by adding a specific foaming agent and an inorganic compound, and if necessary, a foam stabilizer and chlorinated paraffin. It relates to an added urethane prepolymer composition.

[0002]

2. Description of the Related Art Polyurethane sealing materials are mainly composed of urethane prepolymers containing isocyanate groups (NCO) at the molecular ends, and other plasticizers, fillers, thixotropic agents, etc. There is an added one-component sealant, which reacts with moisture in the air to cure. There is also a two-component sealing material containing the urethane prepolymer as a base, a polyol having active hydrogen as a curing agent, and a plasticizer, a filler, a thixotropic agent, etc. as a base. It is cured by mixing a curing agent. By the way, these sealing materials may be required to have flame retardancy depending on the place of use, and particularly in the case of a two-component type sealing material, there are cases where flame retardancy of the urethane prepolymer as a base is required for storage. Until now, there has been no effective means for making flame retardant.

[0003]

Therefore, the present inventors have
As a result of extensive studies aimed at making the urethane prepolymer flame-retardant, if a specific foaming agent or an inorganic compound is added to the urethane prepolymer, a foam layer and a carbonized and solidified layer are formed at a temperature below the flash point by heating. By adding the foaming agent and the inorganic compound, in addition to the foaming agent and the inorganic compound, the amount of the foaming agent and the inorganic compound can be reduced by using the foam stabilizer and the chlorinated paraffin together. , And at the same time, the recurrent action occurs,
It was found that the subsequent flame retardant effect can be maintained more stably, and the present invention has been completed.

That is, the present invention relates to a urethane prepolymer containing NCO at the molecular end, a nitroso type foaming agent,
A urethane prepolymer composition characterized by adding at least one of an azo type foaming agent and an inorganic compound, and a nitroso type foaming agent to the urethane prepolymer.
A urethane prepolymer composition comprising at least one of an azo foaming agent and an inorganic compound, a foam stabilizer and a chlorinated paraffin.

The urethane prepolymer used in the present invention refers to a reaction product of a polyol and an excess of polyisocyanate, and generally contains 0.5 to 5% (% by weight, hereinafter the same) of NCO at its molecular end. To do.

The above-mentioned polyols include ethylene glycol, propylene glycol, diethylene glycol,
Dipropylene glycol, 1,3-butanediol, 1,
4-butanediol, 4,4'-dihydroxydiphenylpropane, 4,4'-dihydroxydiphenylmethane, glycerin, 1,2,6-hexanetriol, 1,
Polyether polyol obtained by addition-polymerizing alkylene oxide such as ethylene oxide, propylene oxide and butylene oxide to at least one kind of 1,1-trimethylolpropane, pentaerythritol, sorbit, sucrose, etc., other polytetramethylene ether polyol, polymer Examples include polyols and polybutadiene polyols. Ethylene glycol, if necessary
Propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, triethylene glycol, tripropylene glycol, 1,3-
Add polyhydric alcohols such as butanediol, 1,4-butanediol, bishydroxyethylhydroquinone, glycerin, 1,2,6-hexanetriol, 1,1,1-trimethylolpropane, pentaerythritol and diglycerin May be.

The above polyisocyanates include 2,4
-Tolylene diisocyanate or 2,6-tolylene diisocyanate or a mixture thereof, crude tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate or 2,4'-diphenylmethane diisocyanate or a mixture thereof, polymethylene polyphenyl polyisocyanate (crude Diphenylmethane diisocyanate), xylylene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and hexahydroxylylene diisocyanate.

In the present invention, an additive component used for flame retarding the above urethane prepolymer (hereinafter referred to as flame retardant component)
Examples of the nitroso-based foaming agent include dinitropentamethylenetetramine and N, N'-dimethyl-N, N '.
-Dinitrosoterephthalamide), azo blowing agents (eg azobisisobutyronitrile and diazoaminobenzene) and inorganic compounds (eg aluminum hydroxide, magnesium borate and activated carbon),
At least one of these is used. The amount used is usually selected in the range of 0.1 to 5.0 parts based on 100 parts of the urethane prepolymer (parts by weight, the same applies hereinafter). If it is less than 0.1 part, the desired flame retardant effect due to foaming and carbonization will not be exhibited, and if it exceeds 5.0 parts, the workability tends to decrease due to thickening.

The foam stabilizer used in the present invention is particularly preferably a silicone type. Such a foam stabilizer can maintain the foam formation of the foam layer formed by the flame retardant component,
Further, by using this foam stabilizer, the effective amount of the flame retardant component can be reduced, which leads to cost reduction and improved sealing performance. The amount of the foam stabilizer used is usually 0.1 to 5.0 parts, preferably 0.3 to 3.0 parts, relative to 100 parts of the urethane prepolymer. 0.
If it is less than 1 part, the foam formation in the foam layer cannot be maintained, and if it exceeds 5.0 parts, the performance and physical properties of the sealing material tend to be deteriorated.

The chlorinated paraffin used in the present invention functions as a foaming aid and contributes to stabilization of the foamed layer after storage (that is, stabilization of foamability). The amount used is usually 0.1 to 10 parts per 100 parts of the urethane prepolymer,
Preferably, it may be selected within the range of 0.1 to 5 parts. 0.1
If it is less than 10 parts, the effect as a foaming aid and the stabilization of the foamed layer after storage cannot be obtained, and if it exceeds 10 parts, the performance and physical properties as a sealing material tend to be deteriorated.

The urethane prepolymer composition according to the present invention is composed of the above-mentioned urethane prepolymer and a flame retardant component, or a system in which a foam stabilizer and chlorinated paraffin are added thereto. Ordinary plasticizers (dibutyl phthalate, dioctyl phthalate, dioctyl adipate, dibutyl sebacate, tris chloroethyl phosphate, etc.), thixotropy imparting agents (fine silica powder, etc.) depending on applications such as architectural sealants and other adhesives. ,
A catalyst (dibutyltin dilaurate, tin octoate, lead octoate, etc.), a stabilizer, a colorant (titanium oxide, carbon black, etc.), a filler (calcium carbonate, talc, etc.) and the like may be added.

[0012]

The composition of the present invention having the above constitution can be decomposed when heated to form a foamed layer and a carbonized and solidified layer on the surface or inside of the urethane prepolymer, which has been a problem in the past. Flame retardation of the urethane prepolymer is achieved.

[0013]

EXAMPLES Next, the present invention will be specifically described with reference to Examples and Comparative Examples. Examples 1 to 7 and Comparative Example 1 Production of Urethane Prepolymer 70 parts of polyether polyol having a number average molecular weight of 2000 (PP2000 manufactured by Sanyo Chemical Industry Co., Ltd.) and 30 parts of tolylene diisocyanate were reacted at 75 ° C. for 3 hours. hand,
2.0% NCO-containing urethane prepolymer (average molecular weight 35,000, viscosity 20000 cps / 20 ° C.) is obtained. Urethane Prepolymer Composition A urethane prepolymer composition is prepared by adding various flame retardant components shown in Table 1 below to the above urethane prepolymer (Comparative Example 1: No addition) and stirring uniformly. Each composition was subjected to a flash point test with a Cleveland open type flash point measuring device specified by the Fire Service Law, and the storage stability (50 ° C x 7
Days) and the results are listed in Table 2.

[0014]

[Table 1]

[Table 2] Example 8 and Comparative Examples 2 to 5 The urethane prepolymer used in Examples 1 to 7 above was added with the components in the number shown in Table 3 below and uniformly stirred to prepare a urethane prepolymer composition.

[0015]

[Table 3]

Flash Point Test Each composition is stored immediately after preparation (initial stage) or at 80 ° C. for 3 days and then at 50 ° C. for 1 month (after storage). Subject to flash point test. The results are shown in Table 4.

[0017]

[Table 4]

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Claims (4)

[Claims] 1. A urethane prepolymer composition comprising at least one of a nitroso-based foaming agent, an azo-based foaming agent and an inorganic compound added to a urethane prepolymer having an isocyanate group at a molecular end. 2. The nitroso-based blowing agent is dinitropentamethylenetetramine and N, N′-dimethyl-N, N′-dinitrosoterephthalamide, and the azo-based blowing agent is azobisisobutyronitrile and diazoaminobenzene, and The urethane according to claim 1, wherein the inorganic compound is aluminum hydroxide, magnesium borate and activated carbon, and 0.1 to 5.0 parts by weight of at least one of these is added to 100 parts by weight of the urethane prepolymer. Prepolymer composition. 3. A urethane prepolymer having an isocyanate group at a molecular end, to which at least one of a nitroso-based foaming agent, an azo-based foaming agent and an inorganic compound, a foam stabilizer and a chlorinated paraffin are added. A urethane prepolymer composition. 4. A nitroso-based foaming agent, an azo-based foaming agent and at least one kind of an inorganic compound in an amount of 0.1 to 5.0 parts by weight, and a foam stabilizer in an amount of 0.1 parts by weight per 100 parts by weight of the urethane prepolymer.
The urethane prepolymer composition according to claim 3, wherein 1 to 5.0 parts by weight and 0.1 to 10 parts by weight of chlorinated paraffin are added.