JPH02302418A - Isocyanate prepolymer and its production - Google Patents

Abstract

PURPOSE:To obtain the subject polymer having excellent storage stability, capable of forming a coating film having excellent weather resistance, endurance, etc., and useful as coating, etc., by reacting specific cycloalkanediols with an excess aliphatic diisocyanate compound and removing unreacted material. CONSTITUTION:Cycloalkanediols {preferably mixture of 3,8-bis(hydroxy-methyl)- tricyclo[5,2,1,0<2.6>]decane expressed by formula II and 4,9-bis(hydroxymethyl)- tricyclo[5,2,1,0<2.6>]decane expressed by formula III} expressed by formula I are reacted with an aliphatic diisocyanate (e.g. hexamethylene diisocyanate) of excess amount based on the diols and then unreacted diisocyanate compound is removed to provide the objective prepolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a new and useful isocyanate prepolymer and a method for producing such an isocyanate prepolymer.

More specifically, the present invention relates to incyanate preprimers which are obtained by reacting cycloalkanediols with aliphatic diisocyanate compounds and which are useful in the fields of paints, adhesives, sealants, molding materials, etc., and methods for producing the same.

More specifically, the present invention relates to an isocyanate prepolymer having excellent storage stability and a method for producing the same, and furthermore, the present invention relates to an isocyanate prepolymer having low toxicity and durability. Therefore, the present invention relates to an incyanate prepolymer that is extremely useful in a wide range of fields such as paints and adhesives, and a method for producing the same.

[Conventional technology]

Until now, as isocyanate prepolymers,
A variety of compounds have been used, but among them, the most common ones are those obtained by urethanization reactions between organic diisocyanate compounds and various polyols such as alkylene diols and polyester diols.
There are isocyanate prepolymers containing isocyanate groups at the molecular ends, but all of these types of isocyanate prepolymers are used in combination with various polyols, and they can easily be used in combination with various polyols. It is extremely useful in applications such as paints and adhesives because it gives a hardened product.

In this case, when aliphatic diisocyanates are used as the organic diisocyanate compound, inocyanate polymers, which have excellent weather resistance in addition to such mechanical properties, can be used as inocyanate polymers.
It can be said that it is a particularly useful industrial material.

However, isocyanate prepolymers obtained using aliphatic diisocyanates such as hexamethylene diisocyanate are easily used as industrial materials, for example for paints, because they tend to become cloudy due to separation and crystallization. When applied, turbidity can cause
The reality is that this has become a major hindrance in practical use, such as the appearance of 1 "@" on the painted surface.

[Problems that the invention helps solve]

However, the present inventors have solved the above-mentioned drawbacks of the prior art, especially since it does not cause turbidity due to crystallization even when stored at low temperatures, has good storage stability, and has low toxicity. Furthermore, they conducted extensive research in search of industrial materials with excellent weather resistance, durability, and extremely useful physical properties.

As described above, the problem to be solved by the present invention is to solve the problem of turbidity due to crystallization, which is one of the unresolved problems in the prior art. The first object of the present invention is to provide an extremely useful incyanate prepolymer that has excellent storage stability and provides a film with excellent weather resistance, durability, and various physical properties.

[Means to solve the problem]

Therefore, the inventors of the present invention boldly addressed the unresolved problems in the conventional VC technology, and also focused on the new problems to be solved by the invention as described above. Now that all of these problems have been solved, the present invention has been completed.

That is, one object of the present invention is to provide an incyanate prepolymer obtained from a cycloalkanediol represented by the general formula and an aliphatic diisocyanate compound; A cycloalkanediol represented by the general formula is reacted with an aliphatic diisocyanate compound, and then the unreacted diisocyanate compound is removed from the upper eyelid 2! It is intended to provide a back route method for producing incyanate prepolymers, which consists of i-coating.

Here, first, as the cycloalkanediols represented by the above general formula [1], 3,8-bis(hydroxymethyl)-tricyclo(5,2,1,02° 6] Decane and 4,9-bis(hydroxymethyl)-tricyclo[5,2,1,0
Typical examples include 2glue 6]f-can, and mixtures thereof.

However, at present, the commercially available cycloalkanediol is rTCD-Aleoho.
l DM J (produced by Hoechst, West Germany; molecular weight =
196.3), which is the same as the above equation (1
It is a mixture of cycloalkanediols represented by -13 and (1-2), that is, each of the above e- and 3
．． 8-bis(hydroxymethyl)-tricyclo(5,2
, 1,0''6) decane and 4,9-bis(hydroxymethyl)-tricyclo[5,2,1,0''')decane.

Therefore, in the present invention, as a way of representing such a mixture itself, the above general formula (In- is applied to this, and 3(4),8(9)-bis(hydroxymethyl)
-Tricyclo[5,2,1,0'') It will be written as 7'kan.

Next, as the above-mentioned aliphatic diisocyanate compounds, it is particularly desirable to use the compounds 04 to C2o, among which only the most representative ones are listed, such as tetramethylene diisocyanate, hexamethylene diisocyanate, 3-mefk. Examples include nittamethylene diisocyanate, nitotecamethylene diisocyanate, and mixtures thereof.

Also, if specifically desired, cyclohexane diincyanate t fl 1,3-bis(incyanate methyl)
There is no problem in partially using an alicyclic diisocyanate compound such as cyclohexane together with the aliphatic diisocyanate compound 04 to C2o listed above,
In this case, the amount of the alicyclic diisocyanate compound to be used is at most 30,000 ml, in order to prevent the isocyanate prepolymer obtained by the method of the present invention or the method of the present invention from impairing its inherent properties. ] [The amount should be kept to a small amount, with one limit being within i%.

Incyanate grepolymer 'IQ which is the object of the present invention
In producing the product, a cycloalkanediol represented by the above general formula [1] is subjected to a urethanization reaction in an excess of an aliphatic diisocyanate compound. As for the excess ratio, the equivalent ratio (Neolo)1) of the incyanate group of the noisoanate compound to the hydroxyl group of the partner cycloalkanediol [■] is within the range of 4 to 25, preferably 1, and within the range of 8 to 20. Appropriate.

If the equivalent ratio is less than 4, the resulting incyanate grepolymer monochain is likely to be elongated, resulting in the production of a polymer, which is undesirable; This is undesirable because it unnecessarily reduces the yield of the isocyanate prepolymer.

Therefore, the reaction between the cycloalkanediol CI) and the aliphatic twin cyanate compound is usually carried out in the absence of a catalyst over a reaction time of 50 to
Preferably it is carried out in the temperature range of 150°C, in particular A
Specifically, a temperature in the range of 60 to 120°C is suitable.

If the urethanization reaction is carried out at a temperature below 50°C, the reaction will take a long time;
If the temperature exceeds .degree. C., the reaction proceeds too vigorously and is accompanied by side reactions that cause chain elongation, which is not preferable in either case.

[L The appropriate time for the urethanization reaction is 2 to 15 hours.

Next, the reaction mixture after the urethanization reaction is usually purified by distilling off (distilling off) unreacted aliphatic diisocyanate by passing it through a thin film distillation machine to obtain the desired isocyanate prepolymer. However, the resulting product has an extremely low content of unreacted aliphatic diincyanate, low toxicity, and high purity.

Note that the distillation conditions at this time are usually 0.005
~2 Torr #pronation vacuum degree is appropriate, and 80
A distillation temperature of ˜200° C. is suitable.

In addition, the residence time in the thin film distillation machine is within 1 hour, preferably within 30 minutes, and keeping the corners formed in this way for a short time allows the distillation process to maintain high purity without alteration. It also serves the purpose of obtaining incyanate prepolymers.

The production method of the present invention has been described above, and the isocyanate prepolymer of the present invention obtained in this way usually has a prepolymer of the general formula (n) as shown below as a main component. It may contain some chain-extended high molecular weight compounds, and in some cases, allophanate bonds generated by side reactions.

The thus obtained isocyanate blend/IJ of the present invention
It is liquid or semi-solid and has good storage stability, even at low temperatures such as 0°C.
It is extremely useful as an industrial material because it does not precipitate any crystals or increase the amount of crystallized gold, and can maintain its entire transparent liquid or semi-solid state.

That is, the isocyanate prepolymer of the present invention can of course be used as a crosslinking agent for urethane resins as it is, but it can also be used by chain elongation with various diols such as alkylene diols. It is a material suitable for applications such as paints, adhesives, and sealants.

It goes without saying that the incyanate prepolymer of the present invention can be used industrially in a form where the terminal position is an insinate group, but it can be reacted with a known and commonly used 10-layer agent such as methyl ethyl ketoxime. In the form of blocked polyisocyanates, they can serve as important industrial materials, but also in the form diluted with organic solvents or, if desired, mixed with various known and customary fillers such as pigments. May be used.

〔Effect of the invention〕

The incyanate prepolymer of the present invention, which can be easily obtained by the above method, has particularly good storage stability and forms a film with excellent weather resistance and durability. It can be used as it is or by chain elongation with a polyol such as alkylene diol, which is low in toxicity and highly safe. Moreover, it can be used as a curing agent for urethane resins with excellent physical properties, and can also be used as a moisture-curing type. It is made from urethane resin, and is an extremely useful industrial material that can be used as paints, adhesives, sealants, and molding materials.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples. In the following, unless otherwise specified, parts and percentages are as follows:
All items shall be based on weight.

Example 1 In a 5-ton round-split four-flask equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, and an air-cooled tube, 3.50 liters of hexamethylene diisocyanate (molecular weight = 168.2) and r TCD-Alcohol were added. 276.69 of DM J (molecular weight = 196.3) was reacted in a nitrogen gas atmosphere at a temperature of 75° C. for 10 hours to complete the urethanization reaction. (NC010H equivalent ratio = 1
4.8) The reaction mixture is then allowed to reach room temperature and then
80.1g total thin film distiller, 0.2-0.6 Tor
Distillation was carried out at a reduced pressure of 120 to 160°C, and the distillation residue contained tc+8.5 of the target isocyanate prepolymer. ! it (conversion rate = 20.3%)
780.8 g (recovery rate = 97.7%') of unreacted hexamethylene diincyanate was obtained as a distillate. Note that the loss in this distillation step was only 0.8 g.

The nine isocyanate prepolymers thus obtained were subjected to various analytical tests, and the f-ter shown in Table 1 was obtained.

From these analysis results, the target object incyanate pre 4
It was confirmed that the remer belongs to the compound having the structure shown by the above-mentioned formula [■], and furthermore, it was confirmed to have the structure shown by the following formula [111].

The isocyanate prepolymer of this example exhibited a transparent liquid state, and even when stored at 0° C., no turbidity due to crystallization occurred, and the storage stability was extremely good.

Comparative Example 1 3,500g of hexamethylene diisocyanate and 1.
127.0 of 4-butanediol (molecular weight = 90.1)
．． The control isocyanate prepolymer obtained in the same manner as in Example 1, except for changing the method to use 9 and I didn't have it.

Comparative Example 2 3,500.9 and 1 of hexamethylene diisocyanate
．． 1 of 6-hexanediol (molecular weight = 118.2g)
66.6,! Changed to use i' and other than 9,
A control isocyanate prepolymer obtained in the same manner as in Example 1 had already solidified in white at room temperature and had no fluidity.

Comparative Example 3 3,500° of hexamethylene diisocyanate. p and 1
．． 4-Cyclohexane dimetatool (molecular weight = 144.
Except for changing to use 203.2g in 2),
A control incyanate prepolymer obtained in the same manner as in Example 1 solidified as a white color at room temperature and showed no improvement in fluidity.

Example 2゜In place of 3.5009 of hexamethylene diisocyanate, tetramethylene diisocyanate (molecular weight = 14
The urethanization reaction was carried out in the same manner as in the example except that 3,000 g of 0.2) was used, and the thin film distillation treatment was carried out. An incyanate prepolymer was obtained, which, as a result of each analysis, had the general formula [1[)
It was confirmed that the compound belongs to .

The isocyanate derelimer of this example had an incyanate group content of 17.2%, was a transparent liquid, and had good storage stability at 0°C.

Comparative Example 4 3,0009 and 1 of tetramethylene diisocyanate
．． The control incyanate prepolymer obtained in the same manner as in Example 2 except that 127.0 g of 4-butanediol was used had already solidified in white at room temperature and was no longer fluid. He had no money at all.

Example 3 Instead of hexamethylene diisocyanate, the same amount of 3
-Methyl-(Urethanization reaction was carried out in the same manner as in Example 1 except that tamethylene diisocyanate was used, and then thin film distillation treatment was carried out.
The desired incyanate prepolymer was obtained with a conversion rate of 0.1%.

As a result of various analyses, this product was confirmed to belong to the compound represented by the above-mentioned general formula (II).

The incyanate prepolymer of this example had an isocyanate group content of 15.2%, was a transparent liquid, and had extremely good storage stability at 0°C.

Comparative Example 5 3-methyl-pentamethylene diisocyanate 3,5
00! i+ and 127.0. of 1,4-butanediol.
A control incyanate prepolymer obtained in the same manner as in Example 3 except for 9 was changed to use 9 and 9.
It had already solidified into a white color at room temperature and had no fluidity at all.

Claims (1)

[Claims] 1. An isocyanate prepolymer obtained from a cycloalkanediol represented by the general formula ▲ Numerical formula, chemical formula, table, etc.▼… [I] and an aliphatic diisocyanate compound. 2. General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼… [I] Cycloalkanediols represented by the diols are reacted with an excess amount of aliphatic diisocyanate compound, and then the unreacted A method for producing an isocyanate prepolymer, comprising removing an aliphatic diisocyanate compound. 3. The cycloalkanediols represented by the above general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼… [ I ] are respectively represented by the formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼… [ I -1] 3,8-bis(hydroxymethyl)-tricyclo[5.2.1.0^2^,^6]decane and 4 shown by the formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [I -2] , 9-bis(hydroxymethyl)-tricyclo[5.2.1.0^2^,^6]decane. 4. The cycloalkanediols represented by the above general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼… [ I ] are respectively represented by the formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼… [ I -1] 3,8-bis(hydroxymethyl)-tricyclo[5.2.1.0^2^,^6]decane and 4 shown by the formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [I -2] , 9-bis(hydroxymethyl)-tricyclo[5.2.1.0^2^,^6]decane. 3. The method for producing an isocyanate prepolymer according to claim 2, wherein the isocyanate prepolymer is a mixture with .