JPH10195165A - Foamed urethane resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition which facilitates agitation during production, gives a foam with low compression set after foaming, and, when used for a sealant for a vehicle lighting fixture, facilitates dismantling and enables the recycling of the lighting fixture by blending selected polyol compounds, a dimerization catalyst, a resinification catalyst, and an isocyanate compound having terminal isocyanato groups. SOLUTION: It is desirable that the polyol compounds contain at least 70 pts.wt. trifunctional polyol having an average molecular weight of at least 3,000 and at least 2 pts.wt. difunctional polyol having an average molecular weight of at most 1,000 and/or trifunctional polyol having an average molecular weight of at most 1,500 and that 100 pts.wt. polyols are blended with 0.5-10 pts.wt. dimerization catalyst and 0.001-1 pt.wt. resinification catalyst. The isocyanate compound having terminal isocyanato groups preferably comprises a urethane prepolymer having an NCO group content of at least 4%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a urethane foam resin composition having a small compression set and, more particularly, to a recycled material which is useful as a sealing material for vehicle lamps, has a small compression set even under heating conditions and has excellent heat resistance. The present invention relates to a urethane foam resin composition which is easily disassembled at the time.

[0002]

2. Description of the Related Art A vehicular lamp such as a headlight or a rear combination lamp basically includes a housing serving as a main body, a light source, and a reflector for reflecting light of the light source forward (in some cases, the reflector is included in the housing). is there)
And a lens for condensing light from the light source and the reflector. In a vehicle lamp such as a headlight, if water or the like enters the inside, the light source may be damaged or the light amount may be reduced. Therefore, a sealing material (gasket, packing) is disposed at a joint between the housing and the lens. Liquid (air) tightness is maintained between the two. On the other hand, in the rear combination lamp, since a lamp is embedded in a vehicle body such as a trunk room, a sealing material (packing material) is provided between the vehicle body and the lamp.

Conventionally, such a sealing material for a vehicular lamp has been formed by a so-called hot melt, and a groove formed at a joint portion of a housing or a lens is filled with a molten hot melt to form a seal between the housing and the lens. By combining the above, the housing and the lens are adhered to each other to keep them liquid-tight. However, in the conventional method using hot melt, the two parts are adhered to each other, and it is necessary to replace all the vehicle lamps except for the light source because only one of the components such as the housing, the lens and the reflector is damaged. Also, there is a problem that various members such as a housing and a lens cannot be recycled at the time of discarding (or scrapping) a vehicle lamp or the like. In addition, if hot melt adheres to an unnecessary portion during the manufacture of a vehicle lamp or the like, the hot melt cannot be completely removed and causes a complaint. Therefore, there is a problem that the member must be discarded.

As a means for solving the problems of such a method using a hot melt, there is known a method of using a foam such as a urethane resin foam or a silicone resin foam as a sealing material. Japanese Patent Application Laid-Open No. 52-113194 discloses a method using a vinyl chloride sol.
Japanese Patent No. 4876 discloses a method using a foamable polysiloxane.

According to the method using a foam, the housing and the lens, and furthermore, both of them and the sealing material are not adhered to each other, so that even when the housing or other member is damaged, only the damaged member can be replaced and discarded. At times, each member can be recycled. Further, even when the composition adheres to an unnecessary portion, the composition can be completely removed after curing, so that there is no need to dispose of the member.

In a method of using a foam as a sealing material, a water-foamable urethane is known as the foam. However, when a two-liquid water-foamable urethane is used as the foam, a two-liquid mixing and discharging machine (dynamic mixer) equipped with a dynamic rotor is required because the compatibility of water, isocyanate and polyol is not good. However, the apparatus is expensive and maintenance is difficult. In addition, since the motor for rotating the rotor is heavy, it is necessary to use a large robot that can withstand this weight when applying the coating with a robot, which is a great limitation.

Further, the conventional urethane foam has a large compression set, and particularly a large compression set under a heating condition. Therefore, when used as a sealing material, it is easy to settle when pressed between members to be sealed. Had a problem.

[0008]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, allows easy stirring during production, has a small compression set of foam after foaming, and can be disassembled after being used as a sealing material for a vehicle lamp. Provided is a urethane foam resin composition which is easy and is useful as a sealing material for a vehicle lamp which enables recycling of the vehicle lamp.

[0009]

That is, the present invention provides a foamed urethane resin composition containing a polyol compound, a dimerization catalyst, a resinification catalyst, and an isocyanate compound having an isocyanate group at a terminal and having a small compression set. I do.

The above-mentioned polyol compound may be composed of 70 parts by weight or more of a trifunctional polyol having an average molecular weight of 3000 or more, and 2 parts by weight or more of a bifunctional polyol having an average molecular weight of 1000 or less and / or a trifunctional polyol having an average molecular weight of 1500 or less. And the polyol compound 100
It is preferable that the dimerization catalyst contains 0.5 to 10 parts by weight and the resinification catalyst contains 0.001 to 1 part by weight with respect to parts by weight.

Further, the present invention provides a sealing material for a joint of a vehicular lamp containing the urethane foam resin composition.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The present invention relates to a foamed urethane resin composition containing a polyol compound, a dimerization catalyst, a resinification catalyst, and an isocyanate compound having an isocyanate group at a terminal and having a small compression set.

The polyol compound used in the present invention comprises:
There is no particular limitation as long as the compression set is small when the foam is used. However, a preferred embodiment is that a trifunctional polyol having an average molecular weight (weight average molecular weight, hereinafter simply referred to as an average molecular weight) of 3000 or more is 70 parts by weight or more. Molecular weight 10
And a bifunctional polyol having an average molecular weight of 1500 or less and / or a bifunctional polyol having an average molecular weight of 1500 or less. Foams such as urethane foam resin generally have a large compression set, but the urethane foam resin composition of the present invention preferably contains a polyol having the above average molecular weight and functional number, so that crosslinking between polyol compounds or the like will be described later. By controlling the crosslinking of the isocyanate compound and the polyol compound to be performed, it is possible to obtain a urethane foam having a small compression set and a small set even after being compressed for a long time. Preferably, 5
It is possible to reduce the compression set after 22 hours from 0% compression to 50% or less.

The trifunctional polyol having an average molecular weight of 3,000 or more is a base polyol for producing a urethane foam formed by a crosslinking reaction with an isocyanate compound described later. The content of the trifunctional polyol having an average molecular weight of 3000 or more is 70 parts by weight or more, preferably 70 to 9 parts.
8 parts by weight, more preferably an average molecular weight of 5,000 to 5,000.
It contains 75 to 98 parts by weight of 9000 trifunctional polyols. If the amount of the trifunctional polyol having an average molecular weight of 3000 or more is less than 70 parts by weight, the amount of the base polyol that gives a crosslinking point in the crosslinking reaction is not sufficient, which is not preferable. Further, the average molecular weight of the trifunctional polyol is 3
If it is less than 000, the hardness is high and the compressive force is increased, which is not preferable. Examples of the trifunctional polyol include trihydric alcohols such as glycerin, hexanetriol and trimethylolpropane; alkanolamines such as triethanolamine and tripropanolamine; trihydric phenols such as pyrogallol and pyrologlucinol; And a trifunctional polyol having an average molecular weight of 3000 or more obtained by adding one or more alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran to one or more of the above. These trifunctional polyols may be used alone or in combination of two or more.

The content of the bifunctional polyol having an average molecular weight of 1000 or less and / or the trifunctional polyol having an average molecular weight of 1500 or less is 2 parts by weight or more, preferably 2 to 30 parts by weight, more preferably 2 to 30 parts by weight. It contains 2 to 10 parts by weight of a bifunctional polyol having an average molecular weight of 150 to 600 and / or 5 to 20 parts by weight of a trifunctional polyol having an average molecular weight of 300 to 700. The above average molecular weight 1
When the content of the bifunctional polyol having a molecular weight of 000 or less and / or the trifunctional polyol having an average molecular weight of 1500 or less is less than 2 parts by weight, heat resistance is not improved, which is not preferable.
Further, the molecular weight of the bifunctional polyol is more than 1000, or the molecular weight of the trifunctional polyol is more than 1500, that is, the molecular weight of the bifunctional polyol and the trifunctional polyol is
If it is more than 500 per functional group, heat resistance is not improved, which is not preferable. Examples of the trifunctional polyol include, for example, those having an average molecular weight of 1500 or less among the trifunctional polyols exemplified in the paragraph on the above-mentioned trifunctional polyol having an average molecular weight of 3000 or more. Further, other examples include low-molecular trifunctional polyols such as glycerin, hexanetriol, and trimethylolpropane. Examples of the bifunctional polyol include dihydric alcohols such as ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, diethylene glycol and dipropylene glycol; resorcinol, 4,4′-dihydroxyphenyl One or more dihydric phenols such as propane, 4,4'-dihydroxyphenylmethane and bisphenol; and one or more alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide and tetrahydrofuran With an average molecular weight of 1000
The following can be mentioned. In addition, other 2
Preferable examples of the functional polyol include low molecular polyols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, pentanediol, and hexanediol.
One or more of these trifunctional polyols and bifunctional polyols may be used in combination.

In a preferred embodiment, the foamed urethane resin composition of the present invention may contain other polyols in addition to the above-mentioned essential polyols. As such a non-essential polyol, for example, a bifunctional polyol having an average molecular weight of 1,000 or more, preferably 2000 to 4000, a trifunctional polyol having an average molecular weight of 1500 to 3000, a polyfunctional polyol, or the like can be used. When a polyol other than the essential component is contained, there is an advantage that the foam hardness can be improved. The urethane foam resin composition of the present invention comprises these non-essential polyols in 3% of all polyols.
0% by weight or less, preferably 10 to 20% by weight. More preferably, the average molecular weight is 2,000 to 4,000.
10 to 20% by weight of a bifunctional polyol, or 10 to 20% by weight of a bifunctional polyol having an average molecular weight of 2000 to 4000.
It may contain 20% by weight and 10-20% by weight of the polyfunctional polyol.

As the dimerization catalyst used in the present invention, those which promote the dimerization reaction of isocyanate and promote the formation of carbodiimide are used, and a preferred example is a phosphorus-based catalyst. As the phosphorus-based catalyst, specifically,
3-Methyl-1-phenylphosphorene oxide, other phosphine oxides, phosphine complexes and the like (for example, camphenephenylphosphine oxide and those exemplified by the following formulas) are preferable. However, two or more kinds may be used in combination.

Embedded image

The amount of the dimerization catalyst is 0.5 to 10 parts by weight, preferably 1 to 5 parts by weight, per 100 parts by weight of the polyol compound.

The resinification catalyst used in the present invention includes:
Preferred examples include amine-based catalysts and tin-based catalysts. Specifically, as the amine catalyst, triethylenediamine, N, N, N ', N'-tetramethylhexane-1,
6-Diamine, tetramethylguanidine and the like are preferred.
As the tin catalyst, dibutyltin dilaurate, dibutyltin diacetate and the like are preferable. The amine catalyst and the tin catalyst may be used alone or in combination of two or more. The amount of the resination catalyst to be added is 0.001 to 1 part by weight, preferably 0.01 to 1 part by weight, per 100 parts by weight of the polyol compound.
0.6 parts by weight.

If the amounts of the dimerization catalyst and the resinification catalyst are within the above-mentioned ranges, foaming of the urethane resin composition and curing of the urethane resin composition using carbon dioxide generated by a dimerization reaction of an isocyanate compound described later. The balance with the reaction is preferable, the urethane resin composition foams uniformly, and the foam after foaming has sufficient elasticity. However, if the amounts of the dimerization catalyst and the resinization catalyst are outside the above-mentioned ranges, the balance between the foaming and the curing reaction of the urethane resin composition becomes unfavorable. That is, if the amount of the dimerization catalyst is less than 0.5 part by weight, the amount of carbon dioxide generated by the dimerization reaction of the isocyanate compound is not sufficient, and the foaming of the urethane resin composition is not sufficient. On the other hand, if the amount of the resin conversion catalyst is less than 0.001 part by weight, the cells of the foam after foaming are not uniform because the crosslinking reaction by the isocyanate compound is not sufficient, which is not preferable.

The isocyanate compound used in the present invention
Contains an isocyanate group at the molecular end
If it is not particularly limited, a known polyurethane resin composition
The used polyisocyanate compound can be used
Wear. Addition of isocyanate compound used in the present invention
The amount is not particularly limited because it varies depending on the curing time.
An appropriate amount may be determined according to the activation time. Used in the present invention
Known polyisocyanate compounds include
Various examples are used for the tongue resin composition,
Specifically, 2,4-tolylene diisocyanate (2,4-
TDI), 2,6-tolylene diisocyanate (2,6
-TDI), 4,4'-diphenylmethanediisocyane
(4,4'-MDI), 2,4'-diphenylmeta
Diisocyanate (2,4'-MDI), p-phenyl
Range isocyanate, polymethylene polyphenylenepo
Polyisocyanate, xylylene diisocyanate (XD
I), 1,5-Naphthalenediisocyanate (NDI)
Aromatic polyisocyanates such as hexamethylene diiso
Aliphatic polyisocyanates such as cyanate (HDI);
Isophorone diisocyanate, H ₆XDI (hydrogenated XD
I), H₁₂Alicyclic polyisomers such as MDI (hydrogenated MDI)
Anate; carbodiimide of each of the above polyisocyanates
Modified polyisocyanates or their isocyanurates
And a salt-modified polyisocyanate. these
Among them, preferred are MDI-based isocyanates.
Can be. One or a combination of two or more of these
Used as a fake.

The isocyanate compound used in the present invention is a reaction product obtained by reacting a polyol compound with an excess of a polyisocyanate compound, and is a so-called urethane prepolymer containing an isocyanate group at a molecular terminal. The urethane prepolymer may preferably have an NCO group content of 4% or more. The urethane prepolymer is used for adjusting the mixing ratio of the two components. The urethane prepolymer is not particularly limited as long as it is produced from a polyisocyanate compound and a polyol used in a known polyurethane resin composition, and examples thereof include urethane prepolymers obtained from MDI and TDI. .

If necessary, the composition of the present invention may further contain a low-activity silicone-based surfactant, a foam stabilizer such as a nonionic or ionic surfactant, an antioxidant, an antioxidant, An ultraviolet absorber, a colorant such as a pigment or a dye, a filler such as calcium carbonate or silica, a softener, a plasticizer, a reinforcing agent such as carbon black or silica, and various additives may be blended.

In the production of the urethane foam obtained from the urethane foam resin composition of the present invention, the urethane foam resin composition of the present invention preferably comprises the polyol which is an essential component of the urethane foam resin composition of the present invention. The compound and the dimerization catalyst and the resination catalyst, and, if necessary, other non-essential polyols, a main agent containing the above various additives, and a curing agent containing an isocyanate compound having an isocyanate group at the terminal. It is composed of two components. In the method for producing the urethane foam obtained from the urethane foam resin composition of the present invention, a carbon dioxide gas generated by a dimerization reaction of an isocyanate compound is prepared by previously mixing and mixing two liquids of the main agent and the curing agent into one liquid. Foaming, and a curing reaction is performed. The production method requires a stirring and mixing step. However, the stirring and mixing step does not include water, and the above components to be stirred and mixed have good compatibility. Therefore, a dynamic mixer that dynamically performs highly efficient stirring. Etc., but it is possible to stir easily without using such an expensive and complicated device, and to sufficiently stir with an inexpensive and simple device such as a static mixer for statically mixing. Is obtained. Further, a heating step may be added to promote the reaction. When the urethane foam resin composition of the present invention is used as a sealing material for a vehicular lamp, the reaction temperature of the heating step is preferably 50 to 100 ° C,
More preferably, it is 70 to 80 ° C. If the temperature exceeds 100 ° C., the members of the vehicular lamp will be denatured.

The foamed urethane resin composition of the present invention may be stirred and mixed by a static mixer or the like as described above, applied, and heated to accelerate the reaction. The urethane foam thus obtained is It can be suitably used as a sealing material for a vehicle lamp, more specifically, for a joint between a housing and a lens of a vehicle lamp and a joint between a vehicle lamp and a vehicle body. That is, since the urethane foam obtained by foaming and curing the urethane foam resin composition of the present invention has a small compression set, the urethane foam is preferably used as a sealing material without sagging even when pressed at the joint of a vehicle lamp. Can be used. Further, since the urethane foam resin composition of the present invention does not adhere the housing and the lens of the vehicle lamp, furthermore, both the sealing material, or the vehicle lamp and the vehicle body, and furthermore, both the sealing material and the member such as the housing. Even when damaged, only the damaged member can be replaced, and also at the time of disposal, disassembly is easy and each member can be recycled.

The housing of the vehicle lamp and the seal of the lens and the seal of the vehicle lamp and the vehicle body will be described below as examples of the sealing material for the joint of the vehicle lamp with the urethane foam resin composition of the present invention. A specific example of the use of will be described. The following description refers to the accompanying drawings.

FIG. 1 is a schematic sectional view of an example in which the urethane foam resin composition of the present invention is used as a sealing material in a vehicle lamp used as a headlamp. As shown in FIG. 1, a vehicular lamp 10 used as a headlamp basically holds a light source 12 and a light source 12 at a predetermined position, and has a reflecting mirror on the inner surface to reflect light forward. A housing 14 containing a reflector 15
The open surface of the housing 14 is closed, and a lens 16 for dimming light is integrally formed. The vehicle lamp 10 used as the headlamp in the illustrated example is an example in which the reflector 15 is included in the housing 14, but the vehicle lamp to which the present invention corresponds is not limited to this configuration. For example, the configuration in which the reflector and the housing are separated from each other can cope with all the lens seals of known vehicle lamps such as headlamps and fog lamps. A flange 18 is formed at the upper end on the open side of the housing 14 so as to protrude outward over the entire circumference.
A sealing groove 20 is formed in the flange 18, and a sealing material 22 is inserted (filled). The lens 16 has a joint groove (projection at the lower end of the outer peripheral portion = lens foot) in a seal groove 20.
The lens 16 and the housing 14 are pressed and fixed to each other by a clamp 24 or the like having spring elasticity, so that the open surface of the housing 14 is closed, and the lens 16 and the housing 14 are closed. The joint portion with the liquid 14 (liquid) is formed by the sealing material 22.
The vehicle lamp 10 used as a headlamp is tightly joined.

When the urethane foam resin composition of the present invention is used as the sealing material 22, the urethane foam obtained from the urethane foam resin composition of the present invention has a small compression set. It is preferable as a sealing material without sticking. Further, since the urethane foam obtained from the urethane foam resin composition of the present invention only presses the lens 16 and the housing 14 and the sealing material 22 and the lens 16 and the housing 14 but does not adhere them, Lens 16 and housing 14
In the event of damage, these members can be easily disassembled, and only the damaged members can be replaced, and each member can be recycled even at the time of disposal.

FIG. 2 is a conceptual diagram showing a state in which a vehicle lamp as a rear combination lamp is mounted on a rear portion of the vehicle. FIG. 3 is a cross-sectional view along XY of a joint between the vehicle lamp and the vehicle body in FIG. 2. The urethane foam resin composition adjusted by stirring and mixing in advance is applied to a predetermined position 4 of the body panel 3 in FIG. 3, and heated if necessary.
After foaming and curing, a predetermined position of the vehicular lamp 1 is pressed thereon to form a sealing material (packing material) 2. Since the urethane foam resin composition has low adhesiveness and low compression set, it is suitable as a sealing material between the body panel 3 and the vehicle lamp 1. Further, even when the body panel 3 and the vehicle lamp 1 are not adhered to each other and the sealing member 2, the body panel 3 and the vehicle lamp 1 are not bonded, and the vehicle lamp 1 is damaged, the broken vehicle lamp 1 is disassembled. Therefore, only the damaged member can be replaced, and each member can be recycled even at the time of disposal.

[0030]

EXAMPLES The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the following examples.

In the following examples and comparative examples, test pieces were prepared with the compositions shown in Table 1 below, and the obtained test pieces were evaluated for foam hardness, compression set, and foamability. (Examples 1 to 4) A base material and a curing agent having the compositions shown in Table 1 below were mixed, heated at 80 ° C. for 15 minutes, foamed and cured to prepare a test piece, and the foam hardness, compression set, and foamability were measured. evaluated. (Comparative Examples 1 to 5) Test pieces were prepared from the main agent and the curing agent having the compositions shown in Table 1 in the same manner as in the examples.
In Comparative Example 1, a test piece was prepared from such a main agent and a curing agent without containing a resin catalyst in the main agent, and foamability was evaluated. In Comparative Example 2, a test piece was prepared from such a main agent and a curing agent without containing a dimerization catalyst in the main agent, and foamability was evaluated. In Comparative Examples 3 to 5, the compositions of the polyol compound and the content of the isocyanate compound were changed to prepare and evaluate those having a large compression set.

The evaluation methods for the foam hardness, compression set and foaming property of the obtained test pieces are as follows. 1) Foam hardness The foam hardness was measured with an Asker C type hardness meter. 2) Compression set It was measured with the aid of the method of JIS K6401. 50
% Of the test piece was held for 22 hours after removing the load, the thickness of the test piece was measured, and the compression set [%] was calculated by the following equation.

[0033]

(Equation 1) In the formula, H ₀ : initial thickness of the test piece (mm) H ₁ : thickness of the test piece after compression (mm) H ₂ : thickness of the spacer (mm) 3) Foamability Foamed urethane resin composition Was visually evaluated. In the table, x indicates that no foaming or uniform foaming was performed, and ◎ indicates that uniform foaming was performed with a substantially uniform cell size.

The components shown in Table 1 used in Examples and Comparative Examples are as follows. Polyol A: trifunctional polyol having an average molecular weight of 5000 (EP33)
0N, manufactured by Mitsui Toatsu Chemical Co., Ltd.) and a trifunctional polymer polyol having an average molecular weight of 8000 (POP36 / 20, manufactured by Mitsui Toatsu Chemicals) in a ratio of 8: 2. B: Bifunctional polyol having an average molecular weight of 150 (triethylene glycol) C: Bifunctional polyol having an average molecular weight of 4000 (Exce
nol 510, manufactured by Asahi Glass Co.) Catalyst D: Dimerization catalyst (carbodiimidization catalyst): 3-methyl-1-phenylphospholene oxide E: Resinization catalyst (amine-based catalyst): Triethylenediamine Foam stabilizer: DABCO33LV, air Fillers: Calcium carbonate (MS700, manufactured by Maruo Calcium Co.) Isocyanate compound F: Urethane prepolymer (M-50, manufactured by Mitsui Toatsu Chemical Co., Ltd.) having an NCO group content of 31.5% and having MDI at the terminal G: 20 parts by weight of a diol having an average molecular weight of 4000 and MDI
The NCO group content adjusted from 24 parts by weight of the compound is 1
Urethane prepolymer having MDI at 6% terminal (M-
50 and Exenol 510 are prepolymerized)

[0035]

[Table 1]

[0036]

The foamed urethane resin composition of the present invention does not contain water, so that it has good compatibility and does not require a stirring step in its production, or can be sufficiently stirred even by using a static mixer or the like. And so on. Further, the foamed foam of the urethane foam resin composition of the present invention has a small compression set and excellent heat resistance even under heating conditions while being a foam, so that it can be suitably used as a sealing material for a vehicle lamp. it can. Further, since the member to be joined to the sealing member is not bonded, the member can be easily disassembled, and the vehicle lamp, which cannot be provided by the sealing member by the hot melt method, can be recycled.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of an example of a vehicular lamp using the sealing method of the present invention.

FIG. 2 is a conceptual diagram showing an example of a state in which a vehicle lamp is mounted on a rear part of a vehicle body.

FIG. 3 is a schematic view of a section taken along line XY of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle light 2 Seal material 3 Body panel 4 Seal material application position 10 Vehicle light 12 Light source 14 Housing (also reflector) 15 Reflector 16 Lens 18 Flange 20 Seal groove 22 Seal material 24 Clamp

Claims (3)

[Claims] 1. A foamed urethane resin composition comprising a polyol compound, a dimerization catalyst, a resinification catalyst, and an isocyanate compound having an isocyanate group at a terminal and having a small compression set. 2. The polyol compound has an average molecular weight of 30.
70 parts by weight or more of a trifunctional polyol of 00 or more, and 2 parts by weight or more of a trifunctional polyol having an average molecular weight of 1000 or less and / or a trifunctional polyol having an average molecular weight of 1500 or less, and based on 100 parts by weight of the polyol compound. The foamed urethane resin composition according to claim 1, wherein the dimerization catalyst contains 0.5 to 10 parts by weight, and the resinification catalyst contains 0.001 to 1 part by weight. 3. A sealing material for a joint of a vehicular lamp containing the urethane foam resin composition according to claim 1.