JP2000169542A - Flame-retardant polyurethane resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide flame-retardant polyurethane resin compositions having a high moisture resistance by using a polyurethane resin composition having an isocyanurate ring without containing atoms such as phosphorus and a halogen. SOLUTION: Flame-retardant polyurethane resin compositions contain a polyurethane to be obtained by reacting a polyol composed of at least one component having an average content of oxygen atoms of not more than 20 wt.% with a polyisocyanate in such a weight, based on the polyol, that the NCO/OH index to be obtained from the ratio of the number of isocyanate groups to the number of hydroxyl groups of the polyol is in the range of 200-2,000 with the use of a metal based isocyanurate-forming catalyst in an amount of 0.5-20 pts.wt. based on 100 pts.wt. polyol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant polyurethane resin composition, and more particularly, to heat resistance and moisture resistance having an isocyanurate ring in a molecule formed using a polyol having a low oxygen content. And a flame-retardant polyurethane resin composition having excellent heat resistance.

[0002]

2. Description of the Related Art Conventionally, flame-retardant, heat- and moisture-resistant materials have been required for LSI sealants, circuit board storage cases, circuit board materials, and the like, and polymers containing atoms such as phosphorus and halogen have been required. Is used. However, polymers containing phosphorus and halogens have a problem that toxic substances such as dioxin are generated when incinerated at the time of disposal, so that alternative materials have been required.

[0003]

In order to solve this problem, it is considered to use, for example, a polyurethane resin composition having an isocyanurate ring. Since the polyurethane resin composition having an isocyanurate ring has a network having a cyclic two-dimensional structure, the flame retardancy and heat resistance can be expected to be improved. In addition, it is possible to incinerate or pulverize and reuse it for disposal.
It is also preferable in terms of environmental conservation.

[0004] However, in polyurethanes having isocyanurate rings, isocyanates and polyols are usually polymerized under the condition that NCO groups are in excess. However, since the polyol contains hydrophilic hydroxyl groups, the resulting polyurethane resin composition The product has poor moisture resistance. In preparing polyurethane, an isocyanuration catalyst is usually used. However, this isocyanuration catalyst remaining in the polymer may be used because it may act as a decomposition catalyst when actually used at a high temperature. The desired flame retardancy and heat resistance may not be obtained depending on the isocyanurate-forming catalyst.

The present invention has been made to solve such problems, and an object of the present invention is to use a polyurethane resin which does not contain atoms such as phosphorus and halogen and has an isocyanurate ring. Another object of the present invention is to provide a flame-retardant polyurethane resin composition having high moisture resistance.

[0006]

The flame-retardant polyurethane resin composition of the present invention has an average oxygen atom content of 20% by weight.
A polyol consisting of one or more of the following components,
NCO / O determined from the ratio of the number of isocyanate groups to the number of hydroxyl groups of the polyol relative to the polyol
A polyisocyanate having an H index in the range of 200 to 2,000,
It is characterized by containing a polyurethane obtained by reacting with a metal-based isocyanuration catalyst in a ratio of 0.5 part by weight or more and 20 parts by weight or less with respect to 00 parts by weight. Here, the NCO / OH index refers to a value obtained by multiplying the value obtained by dividing the number of isocyanate groups in the polyisocyanate by the number of hydroxyl groups in the polyol by 100, and accordingly, the NCO / OH index = 100 indicates that the number of isocyanate groups and the number of hydroxyl groups are 1: 1.

In the flame-retardant polyurethane resin composition of the present invention, a polyol comprising one or more components having an average oxygen atom content of 20% by weight or less is used. The hydrophilicity of the product is reduced, and the moisture resistance is improved.

The flame-retardant polyurethane resin composition of the present invention has an NCO / OH index of 200 or more,
Since the number of isocyanate groups is more than the number of hydroxyl groups, an isocyanurate ring is sufficiently formed. The presence of the isocyanurate ring improves the flame retardancy and heat resistance of the obtained polyurethane resin composition.

Further, since the flame-retardant polyurethane resin composition of the present invention is prepared by using a metal-based isocyanuration catalyst, for example, when an amine-based isocyanuration catalyst is used, the flame-retardant polyurethane resin composition may be used at a high temperature. No polyurethane degradation occurs during use.

[0010] The flame-retardant polyurethane resin composition of the present invention, in the above-mentioned constitution, is 120 ° C. and a relative humidity of 95 with respect to the initial hardness of the flame-retardant polyurethane resin composition.
% After being left for 100 hours in an atmosphere of 10% or less and a volume resistivity of 10 ¹¹ Ω · cm or more. By setting the rate of change of hardness and the specific volume resistivity under such conditions as described above, high moisture resistance can be ensured.

Further, the flame-retardant polyurethane resin composition of the present invention has the above-mentioned constitution, and after standing in an atmosphere at 150 ° C. for 100 hours with respect to the initial hardness of the flame-retardant polyurethane resin composition. The rate of change in hardness is 10% or less, and the volume resistivity is 10 ¹¹ Ω · cm or more. By setting the rate of change in hardness and the specific volume resistivity under such conditions as described above, high flame retardancy and heat resistance can be ensured.

[0012]

Embodiments of the present invention will be described below. The flame-retardant polyurethane resin composition of the present invention is prepared using a polyol composed of one or more components having an average oxygen atom content of 20% by weight or less. When the average content of oxygen atoms is more than 20% by weight, the obtained flame-retardant polyurethane resin becomes hydrophilic,
It is not preferable because the moisture resistance decreases.

Preferred polyols include, for example, ester reaction products of a long-chain fatty acid having a hydroxyl group and a polyfunctional polyol. Examples of long-chain hydroxy fatty acids include ricinoleic acid, oxycaproic acid, oxycapric acid, oxyundecanoic acid, oxylinoleic acid, oxystearic acid, oxyhexadecenoic acid, and the like. Of these, ricinoleic acid and oxystearic acid are exemplified. It is preferably used. Examples of the polyfunctional polyol include bifunctional glycols such as ethylene glycol, propylene glycol, butylene glycol, hexamethylene glycol, diethylene glycol, and dipropylene glycol; trifunctional compounds such as trimethylolpropane and triethanolamine; diglycerin;
Examples include tetrafunctional compounds such as pentaerythritol, hexafunctional compounds such as sorbitol, octafunctional compounds such as sugar, and mixtures thereof.

Examples of the polyisocyanate used in the urethane reaction together with the polyol include diphenylmethane diisocyanate (MDI), polymethylene polyphenylene polyisocyanate (crude MDI), polytolylene polyisocyanate (crude TDI), and tolylene diisocyanate (TDI). , Xylylene diisocyanate (XDI), naphthalene diisocyanate (NDI)
Aromatic polyisocyanates such as, aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI),
Examples include alicyclic polyisocyanates such as isophorone diisocyanate (IPDI), and carbodiimide-modified polyisocyanates and isocyanurate-modified polyisocyanates of the above-mentioned polyisocyanates.
In addition, a so-called urethane prepolymer which is a reaction product obtained by reacting an excess of polyisocyanate with a polyol and has an isocyanate group at a molecular terminal can be applied, and a mixture thereof can also be used.

In the present invention, the polyisocyanate is
The amount of the polyisocyanate used is determined so that the NCO / OH index is in the range of 200 to 2,000. When the NCO / OH index is less than 200, the number of isocyanurate rings formed is small,
It is not preferable because flame retardancy and heat resistance are inferior. Also, NC
When the O / OH index is larger than 2,000, the number of isocyanurate rings substantially formed reaches the upper limit, and the effect of increasing the number of NCO groups cannot be obtained.

In the present invention, the above-mentioned reaction between the polyol and the polyisocyanate is carried out using a metal-based isocyanuration catalyst. The metal-based isocyanuration catalyst is used in an amount of 0.5 to 20 parts by weight based on 100 parts by weight of the polyol. When the amount of the metal-based isocyanurate-forming catalyst is less than 0.5 part by weight, sufficient isocyanurate-forming does not occur, which is not preferable. Further, even if the amount of the metal-based isocyanuration catalyst is more than 20 parts by weight based on 100 parts by weight of the polyol, the effect corresponding to the added amount cannot be obtained.

Examples of the metal-based isocyanuration catalyst include:
For example, fatty acid metal salts can be mentioned. Specifically, potassium ricinoleate, sodium ricinoleate,
Examples include potassium stearate, sodium stearate, potassium oleate, sodium oleate, potassium acetate, sodium acetate, potassium naphthenate, sodium naphthenate, potassium octylate, sodium octylate, and mixtures thereof.

The flame-retardant polyurethane resin composition of the present invention has a rate of change in hardness from an initial value of 10% or less when left for 100 hours in an atmosphere at 120 ° C. and a relative humidity of 95%, and has a specific volume resistivity. Is 10 ¹¹ Ω · cm or more. With such a set value, the moisture resistance is maintained and the LSI
It can sufficiently withstand use as a sealant, a circuit board storage case, a circuit board material, and the like.

The flame-retardant polyurethane resin composition of the present invention has a rate of change from the initial value of hardness of 10% or less when left in an atmosphere at 150 ° C. for 100 hours, and a volume resistivity of 10 ^11. Ω · cm or more. With such set values, flame retardancy and heat resistance are maintained, and the material is sufficiently resistant to use as an LSI sealant, a circuit board storage case, a circuit board material, and the like.

[0020]

EXAMPLES Hereinafter, the flame-retardant polyurethane resin composition of the present invention will be described in more detail by way of examples.

(Examples 1 to 6) In a 1,000 cc resin cup, 100 g of a polyol shown in Table 1, 1 g of a metal-based isocyanuration catalyst, and a predetermined amount of a polyisocyanate shown in Table 1 were mixed. After degassing, the mixture was poured on an aluminum mold at 25 ° C., and was cured in about 3 minutes. This cured product was cut into a 40 mm square to prepare a test piece. Using this test piece, the following heat resistance test, room temperature change test, moisture resistance test, and flame retardancy test were performed. Table 1 also shows the results.

(Comparative Examples 1 to 4) With the compositions shown in Comparative Examples 1 to 4 in Table 1, the same operation as in Examples 1 to 6 was carried out.
To 4 were obtained, and test pieces were prepared in the same manner as in Examples 1 to 6 using the same. Using this test piece, the following heat resistance test, room temperature change test, moisture resistance test, and flame retardancy test were performed. Table 1 also shows the results.

[0023]

[Table 1]

(Flame Retardancy Test) US Flame Retardancy Test Method UL-9
4 (1/8 inch). Table 1
The evaluation criteria of “◎”, “○” and “×” in the column of the flame retardancy test are as follows.

…: V-0…: V-2 ×: HB.

(Heat Resistance Test) First, the initial hardness of the test piece was measured. Next, the test piece was left in an atmosphere of 150 ° C. for 100 hours, and its hardness was measured. And
The rate of change of the hardness with respect to the initial hardness was determined. The volume resistivity of the same test piece was measured. The evaluation criteria of “○”, “△” and “×” in the column of the heat resistance test in Table 1 are as follows.

…: Hardness change is 10% or less, volume specific resistivity is 10 ¹¹ Ω · cm or more △: Hardness change is 10% or less, volume specific resistivity is 10 ¹¹ Ω
· Smaller than cm ×: Hardness change is larger than 10%, volume specific resistivity is 10 ¹¹
Less than Ω · cm.

(Moisture Resistance Test) First, the initial hardness of the test piece was measured. Next, the test piece was placed at 120 ° C. and a relative humidity of 9
After being left for 100 hours in a 5% atmosphere, the hardness was measured. Then, the rate of change of the hardness with respect to the initial hardness was determined. The volume resistivity of the same test piece was measured. The evaluation criteria of “○”, “△” and “×” in the column of the moisture resistance test in Table 1 are as follows.

…: Hardness change is 10% or less, volume specific resistivity is 10 ¹¹ Ω · cm or more △: Hardness change is 10% or less, volume specific resistivity is 10 ¹¹ Ω
· Smaller than cm ×: Hardness change is larger than 10%, volume specific resistivity is 10 ¹¹
Less than Ω · cm.

(Room Temperature Curability Test) After mixing a polyol, a polyisocyanate and a metal-based isocyanuration catalyst, the mixture cured within 5 minutes was evaluated as “O”, and was not cured after 5 minutes. Those were marked with "x".

(Test Results) From the results of the tests in Table 1, the evaluations of the flame-retardant polyurethane resins of Examples 1 to 6 were all "O" in any of the tests, and the flame retardancy and heat resistance It was found to be excellent in water resistance and moisture resistance. On the other hand, the flame-retardant polyurethane resins of Comparative Examples 1 to 4 were evaluated as Δ or × in any of the tests. Particularly, in the moisture resistance test, satisfactory results were obtained in all the comparative examples. I couldn't get it.

(Examples 7 to 12) Next, the effect of the difference in the type and amount of the isocyanurate-forming catalyst on the polyisocyanate was examined. With the compositions shown in Table 2, Examples 1 to
By the same operation as in Example 6, flame-retardant polyurethane resins of Examples 7 to 12 were obtained, and respective test pieces were produced. The same test as in Table 1 was performed on the test pieces of Examples 7 to 12, and the results are shown in Table 2.

(Comparative Examples 5 to 9) Next, the flame-retardant polyurethane resins of Comparative Examples 5 to 9 were obtained with the compositions shown in Table 2 by the same operation as in Examples 1 to 6, and each test piece was prepared. did. The same test as in Table 1 was performed on the test pieces of Comparative Examples 5 to 9, and the results are shown in Table 2.

[0034]

[Table 2]

(Test Results) From the results of the tests in Table 2, the flame-retardant polyurethane resins of Examples 7 to 9 using potassium ricinoleate, which is a metal-based isocyanuration catalyst,
In all the tests, the evaluations were all "O", and it was found that they were excellent in flame retardancy, heat resistance and moisture resistance. On the other hand, the flame-retardant polyurethane resins of Comparative Examples 5 to 9 were evaluated as △ or × in any of the tests. Particularly, in the heat resistance test and the moisture resistance test, all of the comparative examples were evaluated. And could not obtain satisfactory results. Comparative Example 6 is a case where a metal-based isocyanurate-forming catalyst and an amine-based isocyanurate-forming catalyst are used in combination. The metal-based isocyanurate-forming catalyst is used in an amount of 0.5 to 20 parts by weight based on 100 parts by weight of the polyol. It can be seen that the flame retardancy, heat resistance and moisture resistance are reduced when the amine-based isocyanuration catalyst is present even when used in a ratio of not more than 3 parts by weight.

In addition, the flame-retardant polyurethane resin compositions of all of the above examples cure within 5 minutes after mixing the polyol, the polyisocyanate, and the metal-based isocyanuration catalyst, so that a curing furnace is not required. Thus, there is an advantage that the productivity can be increased and the cost can be reduced.

[0037]

The flame-retardant polyurethane resin composition of the present invention is prepared using a polyol comprising one or more components having an average oxygen atom content of not more than 20% by weight. Has moisture resistance. Also, NCO / OH
Since it is obtained by reacting a polyol and a polyisocyanate having an index of 200 or more and 2,000 or less, an isocyanurate ring is sufficiently formed, and the obtained polyurethane resin composition has high flame retardancy and heat resistance. are doing. Further, the flame-retardant polyurethane resin composition of the present invention is used in an amount of 0.1 to 100 parts by weight of the polyol.
Since it is obtained by reacting with a metal-based isocyanuration catalyst in a ratio of 5 parts by weight or more and 20 parts by weight or less, polyurethane does not decompose even when used at a high temperature.

The flame-retardant polyurethane resin composition of the present invention can be used in an atmosphere at 120 ° C. and a relative humidity of 95%.
The rate of change of hardness when left for 10 hours is 10% or less,
Since the volume resistivity is 10 ¹¹ Ω · cm or more, high moisture resistance can be secured.

The flame-retardant polyurethane resin composition of the present invention has a hardness change rate of 10% or less and a volume resistivity of 10 ¹¹ Ω · cm when left in an atmosphere at 150 ° C. for 100 hours. As described above, high flame retardancy and heat resistance can be ensured.

Claims (3)

[Claims] 1. A polyol comprising one or more components having an average content of oxygen atoms of 20% by weight or less, and a ratio of the number of isocyanate groups to the number of hydroxyl groups of the polyol with respect to the polyol. Required NCO / O
A polyisocyanate having an H index in a range of 200 to 2,000 is used, and a metal-based isocyanuration catalyst having a ratio of 0.5 to 20 parts by weight based on 100 parts by weight of the polyol is used. A flame-retardant polyurethane resin composition characterized by containing a polyurethane obtained by reacting the same. 2. The rate of change in hardness of the flame-retardant polyurethane resin composition after leaving it in an atmosphere at 120 ° C. and a relative humidity of 95% for 100 hours with respect to the initial hardness of the flame-retardant polyurethane resin composition is 10% or less. The flame-retardant polyurethane resin composition according to claim 1, wherein the modulus is 10 ¹¹ Ω · cm or more. 3. The rate of change of the hardness after being left in an atmosphere at 150 ° C. for 100 hours with respect to the initial hardness of the flame-retardant polyurethane resin composition is 10% or less, and the volume resistivity is 10 ¹¹ Ω. 3. The flame-retardant polyurethane resin composition according to claim 1, wherein the composition is not less than cm.