JPH0489862A - Two-pack polyurethane sealant and composition - Google Patents

Abstract

PURPOSE:To improve the flame retardancy and ease of dismantling by incorporating a flame retardant into a specified polyol component and/or isocyanate component having a dismantling aid incorporated therein. CONSTITUTION:An isocyanate component (A) comprising polymethylene polyphenyl polyisocyanate and/or carbodiimide-modified 4,4'-diphenylmethane diisocyanate that is liquid at ordinary temperature and a polyol component (B) consisting of a polyether polyol having a functionality of 2 to 4 and a number-average molecular weight of 500 to 4,000 and 20-50wt.% polybutadiene polyol having a functionality of 2 to 3 and a number-average molecular weight of 100 to 3,000 and/or castor oil polyol having a functionality of 2 to 3 and a number-average molecular weight of 400 to 1,000 are mixed with a dismantling aid (e.g. dimethylpolysiloxane) in an amount of 0.5-35wt.% based on the total of components A and B, wherein components A and B are mixed so that (NCO/ OH)X100 is 80 to 120. A flame retardant consisting of 40-60wt.% Al(OH)3 having a mean particle diameter of 10-40mum, 3-6wt.% TiO2, and 5-15wt.% tricresyl phosphate is incorporated into this mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to two-part polyurethane sealants and polyurethane compositions that are flame retardant and easily dismantled.

BACKGROUND OF THE INVENTION In recent years, demand for bone sealants has been increasing in a wide range of industrial fields such as architecture, civil engineering, automobiles, and telecommunications.

In particular, polyurethane sealants are in high demand because their performance can be varied in a variety of ways, and they are cheaper than other elastic sealants.Polyurethane sealants come in one-component and two-component types, and are suitable for use in areas where a large area of filling and repair is required. A two-component type is preferred.

SUMMARY OF THE INVENTION The present invention provides a two-component polyurethane sealant particularly suitable for the telecommunications field.

In the telecommunications field, for example, when sealing large switchboards, there is a risk of electrical sparks, and the sealant is required to be flame retardant.

Furthermore, the sealant must be dismantled, peeled off, and refilled for frequent installation of power distribution wires, inspection and repair, etc., so disassembly is required.

In addition, flexibility, antifoaming properties, dehydration properties, and thixotropy properties that are generally required for polyurethane sealants are also required.

The present invention relates to a sealant and a composition that meet these requirements in a well-balanced manner.

Means for Solving the Problems The present invention provides a two-component urethane sealant comprising an isocyanate component and a polyol component. The main component is at least one type of carbodiimide modified product, the main component is a mixture of at least one of polyether polyol, polybutadiene polyol, and castor oil liquid polyol as the polyol component, and the isocyanate component is Or a two-component urethane sealant, which contains a flame retardant in one or both of the polyol components, and a disassembly aid in the polyol component.

2. The flame retardant added to the isocyanate component or polyol component is one or more selected from the group consisting of aluminum hydroxide, titanium dioxide, and tricresyl phosphate with an average particle size of 10 to 40 l. The two-component urethane sealant according to claim 1, wherein the disassembly aid is one or more selected from the group consisting of dimethylpolysiloxane, methylhydrodienepolysiloxane, and alcohol-modified silicone.

3. In a polyurethane composition formed by mixing an isocyanate component and a polyol component, using polymethylene polyphenyl polyisocyanate or a carbodiimide modified product of 4,4°-diphecolmethane diisocyanate that is liquid at room temperature as the isocyanate component, As a polyol component, the main component is a mixture of at least one of polyether polyol, polybutadiene polyol, and castor oil polyol, and as a flame retardant, aluminum hydroxide with an average particle size of 10 to 40 ml is added as a flame retardant.
0-80%, titanium dioxide 3-6% and tricresyl phosphate 5-15%, dimethyl polysiloxane, methylhydrodiene polysiloxane as disassembly aids,
Or alcohol-modified silicon 0.5-35%, other catalysts 0.1-2%, dehydrating agent 1-5%, thixotropy imparting agent 0
．． This is a flame-retardant polyurethane composition characterized by using a mixture containing 2 to 5% of the isocyanate component and the polyol component (each percentage by weight based on the total amount of the isocyanate component and the polyol component).

Hereinafter, the present invention will be explained in detail. In addition, % in the text
and parts are by weight unless otherwise specified.

That is, as the isocyanate component, polymethylene polyphenyl polyisocyanate and liquid MDI obtained by converting a portion of 4°4'-diphenylmethane diisocyanate (MDI) into carbodiimide may be used alone or as a mixture.

On the other hand, as the polyol component, a mixture of polyether polyol as an essential component and at least one of polybutadiene polyol and castor pongee polyol is used.

Polyether polyols are compounds with functional groups of 2 to 2 or more, which are obtained by addition-polymerizing ethylene oxide, propylene oxide, etc. to compounds with active hydrogen atoms such as ethylene glycol, propylene glycol, glycerin, and triethanolamine.
4, and the number average molecular weight is in the range of 500 to 4,000. Preferably, the molecular weight is 1,000 to 3,000. If the molecular weight is less than 1,000, the flexibility is likely to be impaired, and if the molecular weight is 3,000 m, the viscosity of the liquid increases significantly, and when preparing the polyol component, it is difficult to form a powder. This makes mixing the fuel very difficult. Therefore, the larger the amount of polyether polyol used, the easier it is to mix the flame retardant, which is preferable, but it is desirable to use 3 to 20% of the polyol component.

Polybutadiene polyol is a liquid polybutadiene polyol having a functional group number in the range of 2 to 3 and a molecular weight of 100 to 3,000 and having an active hydroxyl group at the end.

The castor pongee yarn polyol has a functional group number in the range of 2 to 3, and a molecular weight of 400 to 1000, and is a polyol having an active hydroxyl group at the end.

This polybutadiene polyol and castor pongee yarn polyol have excellent water resistance, and can be used alone or as a mixture.The larger the amount used, the better, but it is desirable to use 20 to 50% of the polyol component. .

The amounts of the isocyanate component and polyol component described above can be varied within the range of stoichiometrically equal amounts (equivalents) or about ±20% thereof. That is, NGO index/') which represents the reaction ratio between the isocyanate group (NCO) in the isocyanate component and the active hydroxyl group (OH) in the polyol component: (NCOloH)X1
00: can be changed and used in the range of 80-120.

Next, the following additives are added to either or both of the isocyanate component and the polyol component.

(+) As mentioned above, the sealant of the present invention uses a flame retardant.

The flame retardant is mainly S! Use aluminum hydroxide with an average particle size in the range of 10 to 40 μL. When the average particle size is less than 10, the viscosity of the liquid increases and it becomes difficult to handle. Also, 40. If it exceeds the amount, the stability after mixing and dispersion will be poor and two-layer separation will easily occur, which is not preferable.

In addition, organic and inorganic compounds such as trichloroethyl phosphate, tricresyl phosphate, tris (tribromoneopentyl) phosphate,
There are phosphates containing phosphorus, chlorine, and bromine, powdered melamine, PVC powder, chlorinated paraffin, borax, calcium carbonate, antimony trioxide 5 titanium dioxide, etc., and one or more of these types should be used in moderation. I can do it.

Among these flame retardants, powdered flame retardants such as aluminum hydroxide are preferably mixed into the polyol component.

The higher the amount of this flame retardant used, the better the flame retardant effect will be;
It is desirable to set it in the range of 0 to 80%. Usage amount is 40
If it is less than 80%, it becomes difficult to burn, and if it exceeds 80%, the viscosity of the liquid increases, making it difficult to handle and mix with the isocyanate component.

In addition, as a flame retardant, 40 to 80% of aluminum hydroxide with an average particle size of 10 to 40μ, 3 to 6% of dimer + tan, and 5 to 15% of tricresyl phosphate based on the total amount of isocyanate component and polyol component. % of the three components is economically advantageous and easy to handle, and good results can be obtained.

(2) As a disassembly aid, the polyol component and isocyanate component are stirred and mixed and poured into the joint of the floorboards, and when hardening, the purpose is to defoam the air bubbles that are drawn in during stirring, and when disassembling the cured elastomer. It is used for the purpose of making it easier to peel off from floorboards, and is generally used for dimethylpolysiloxanes and methylhydrodienepolysiloxanes shown in the following formula with n = 2 to 2000, and for dimethylpolysiloxanes that are active on the side chains of dimethylpolysiloxanes. The amount of modified resin with one hydroxyl group damaged is preferably in the range of 0.5 to 35% based on the total weight of the polyol component and isocyanate component. If it is less than 0.5%, it is difficult to achieve the desired effect. If it exceeds 35%, the amount that oozes out to the surface increases, which is not reasonable.

Dimethylpolysiloxane recon is used and reacts with a part of the isocyanate component to add it into branches to develop a peeling effect. Generally, X=O to 300. A structure in which Y=0 to 300 and R=alkyl group is used.

Alcohol-free silicone (3) Uses a reaction catalyst between isocyanate and polyol.

The catalyst is an amine compound and an organometallic compound used in the urethanization reaction, such as triethylenediamine, N-ethylmorpholine, N,N' dimethylethanolamine, N-methylmorpholine, dimethylethanolamine (thylaminoethyl) ether, etc. , tetramethylhexamethylene diamine, dibutyltin dilaurate.

These include diazabicycloundecene. The amount of catalyst used can be varied over a wide range depending on the working conditions. For example, when triethylenediamine is used, it is used in an amount of about 0.1 to 2% based on the polyol component.

(4) Also, 1 to 5% of a dehydrating agent is added to the total weight of the isocyanate component and polyol component.

Dehydrating agents prevent isocyanates from reacting with water and causing foaming. For example, zeolite etc. can be used.

(5) Also, in order to impart thixotropy to the total weight of the isocyanate component and the polyol component, the thixotropy imparting agent is 0.2
Add ~5%.

A diamine compound such as diaminodiphenylmethane is used as the thixotropy imparting agent, and the rate at which thixotropy occurs can be changed depending on the working conditions at the site during filling and repair.

(6) A crosslinking agent may also be used to adjust the flexibility and disassembly of the polyurethane.

The crosslinking agent is an active hydrogen compound having 2 to 3 functional groups, such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, glycerin, diglycerin, 1,5 bentanediol, 1,6 hexanediol, ethylenediamine, jetanol. amine, triethanolamine, diaminodiphenylmethane,
1.

3-butanediol, 1.4-butanediol, etc. can be used.

The above sardine additives (1) to (6) can be mainly blended into the polyol component, but flame retardants and the like without reaction activity can be blended into the isocyanate component.

This will be specifically explained below using examples.

Example 1 (Polyol component) Polyether polyol village (equivalent value = 1000, 0.01 equivalent) 1
0 parts castor pongee yarn polyol (equivalent value = 340, 0.176 equivalent) 80 (2,
trifunctional, molecular weight 782) DABC[l -33LV'2 (0,0073M amount)
0.8m diaminodiphenylmethane (DD
M) (0, (11 equivalent) 11/ 5H-200 (viscosity 50 cp) ” 1
0 tt dehydrating agent”4 3
tt titanium dioxide IQ
tt tricresyl phosphate 24
//Aluminum hydroxide (particle size 17$4-) 1
10 tt Note: Wood 1 Addition polymer of glycerin/propylene oxide (trifunctional, molecular weight 3000) 2 Catalyst solution in which 33 g of triethylenediamine is dissolved in 66 g of dipropylene glycol 3rd Dimethylpolysiloxane (manufactured by Toshi Silicone) 4th Zeorum (manufactured by Tosoh) and PR-35 (polyol of Sanyo Chemical) mixed in a ratio of 1:1 as a dehydrating agent (isocyanate component) Polymethylene polyphenyl polyisocyanate (equivalent value = 140, 0.238 equivalent, NCO index =
116.3) 33 parts The above polyol component was weighed and taken into a 500 cc plastic container, and thoroughly stirred and mixed using an electric drill with a cage-type stirring rod (1000 rpm).

After that, the entire amount of the isocyanate component was put into the 500 cc plastic container containing the polyol component, and after stirring and mixing with the above-mentioned stirrer for 30 seconds, the sauce was poured onto an iron plate.
Reacted and cured.

As a result, the obtained polyurethane elastomer can be easily peeled off from the steel plate, has good disassembly properties, has a hardness (C type) of near 7, an oxygen index of 35, and does not ignite and burn even when directly hit by the flame of an acetylene welding burner. No, the parts that were hit by the fire were only partially melted. In addition, the change in viscosity over time after stirring and mixing was measured using a B-type viscometer (25°C).
, the results are shown in Figure 1.

As can be seen from Fig. 1, there is a thixotropic region in which the viscosity changes little at the beginning of the reaction, so it is best to pour the mixed liquid into the filling part during this period, as the viscosity will increase rapidly after that.
Liquid leakage from gaps can be prevented.

Example 2 The same reaction as in Example 1 was carried out with different ingredients and blending amounts.

Cured. The results are shown in Table 1.

Note: Book 1 Relatively low viscosity → small, medium viscosity →
Medium and high items were rated as large.

Book 2 The stability of polyol components is determined by those without phase separation.
Items with l were marked as x.

3. A sample in which the disassembly aid oozed out onto the surface of the cured product and was easily peeled off was rated as ○, and a sample in which it was not easily peeled off was rated as x.

Book 4 The degree of flame retardancy is O
1 or less was marked as ×.

Effects of the Invention As explained above, by using the two-component urethane sealant of the present invention and the composition obtained by mixing, it has become possible to perform filling repairs with excellent flame retardancy and disassembly properties.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between reaction time and viscosity change.

Claims (1)

[Scope of Claims] 1. In a two-component polyurethane sealant comprising an isocyanate component and a polyol component, the isocyanate component is a carbodiimide-modified product of polymethylene polyphenyl polyisocyanate and 4,4-diphenylmethane diisocyanate, which is liquid at room temperature. The main component is at least one of polyol component, polyether polyol is an essential component, and at least one of polybutadiene polyol and castor oil polyol is mixed as the main component, and isocyanate component or A two-component polyurethane sealant comprising a flame retardant in one or both of the polyol components and a disassembly aid in the polyol component. 2. The flame retardant added to the isocyanate component or polyol component is one or more selected from the group consisting of aluminum hydroxide, titanium dioxide, and tricresyl phosphate with an average particle size of 10 to 40μ. 2. The two-component polyurethane sealant according to claim 1, wherein the disassembly aid is one or more selected from the group consisting of dimethylpolysiloxane, methylhydrogenpolysiloxane, and alcohol-modified silicone. 3. In a polyurethane composition formed by mixing an isocyanate component and a polyol component, polymethylene polyphenyl polyisocyanate or a carbodiimide modified product of 4,4'-diphenylmethane diisocyanate which is liquid at room temperature is used as the isocyanate component, and as the polyol component. The main component is a mixture of polyether polyol as an essential component and at least one of polybutadiene polyol and castor oil polyol, and a flame retardant with an average particle size of 10 to 40μ.
aluminum hydroxide 40~80%, titanium dioxide 3~
6% and tricresyl phosphate 5-15%, 0.5-35% dimethylpolysiloxane, methylhydrodiene polysiloxane, or alcohol-modified silicone as a disassembly aid, 0.1-2% other catalyst, dehydration. Agent 1~
A flame-retardant polyurethane composition characterized by using a mixture containing 5% of a thixotropy imparting agent and 0.2 to 5% of a thixotropy imparting agent (all percentages by weight based on the total amount of an isocyanate component and a polyol component).