JPS6023695B2 - Method for producing partially urethanized alicyclic carbodiimide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for producing an alcohol masked aliphatic carbodiimide having improved hydrolysis resistance from an alicyclic diisocyanate, an aliphatic alcohol and a carbodiimidization catalyst.

Specifically, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, 4,4-dicyclohexylmethane diisocyanate, and cyclohexyl-1,3-dimethylisocyanate, alicyclic diisocyanate, aliphatic type. The present invention relates to a method for producing a partially urethane pyogenic carbodimide which exhibits improved hydrolysis resistance by adding alcohol and a carbodimidization catalyst to various polyurethane resins based on polyester.

Conventionally, the product value of various polyurethane resins based on polyester has been significantly impaired in a humid atmosphere because the ester bonds of the polyester are hydrolyzed by moisture. As an effective method for solving this problem, it is generally known that adding a carbodimide compound to polyester improves its hydrolysis resistance.

Isocyanates for producing such carbodimide compounds include 2-methylphenylene-1-isocyanate, 2,6-diisopropylphenylene-1-isocyanate, 2-ethoxyphenylene-1-isocyanate, and 2-chlorophenylene-1-isocyanate. ,
2-nitrophenylene-1-isocyanate, 2,6-diethylphenylene-1-isocyanate, 2,4,6
-triisopropylphenylene-1-isocyanate and other organic monoisocyanates, and tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, metaphenylene diisocyanate, 1,5 naphthylene diisocyanate, 4-chloro-1 , 3-phenylene diisocyanate, 1,3-diisopropylphenylene-2,4-diisocyanate, 1-methyl-3,5-diethylphenylene-2,4-diisocyanate, 1,
3,5-triisopropylphenylene-2,4-diisocyanate, 3,3-diethylupisphenylene-4,4
There are organic diisocyanates such as '-diisocyanate.

Generally, these organic monos or organic diisocyanates are heated (usually 1
50 to 200°C), a mono- or polycarbodiimide compound can be obtained. When the present inventor investigated the effect of adding such conventional mono and polycarposimide compounds to the polyurethane resin on hydrolysis resistance, it was confirmed that the effect was still insufficient as described below.

The present inventor investigated various organic diisocyanates for the purpose of developing carbodiimide compounds that improve the hydrolysis resistance of polyurethane resins based on polyester. It has been found that a partially urethanized alicyclic carbodiimide exhibiting hydrolyzability can be obtained, leading to the present invention.

The present invention will be explained below.

The alicyclic diisocyanate used in the present invention is 3-isocyanatomethyl-3,5,5-trimethylsiloxane.
Hexyl isocyanate (hereinafter referred to as mDI), 4,4
-Jishik.

These are hexylmethane diisocyanate (hereinafter referred to as hydrogenated M-cho 1) and cyclohexyl-1,3-dimethyl isocyanate (hereinafter referred to as hydrogenated XDI). Further, examples of the aliphatic alcohol used in the present invention include methanol, ethanol, and n-phthalate.

Lopyl alcohol, n-butanol, s-butanol,
These include isoamyl alcohol, cyclohexanol, 2-chloro-1-gol, 2-octanol, 2-ethylhexanol, and the like. In this application, unreacted isocyanate groups are masked with aliphatic alcohol because polycarbodiimide has the best solubility in polyurethane resin when the molecular weight of carbodimide is adjusted to 500 to 1000. Since isocyanate groups are present, this is urethanized with alcohol to suppress an increase in molecular weight and a decrease in solubility due to reactions between isocyanate groups. As the carbodimidization catalyst used in the present invention, known phospholines, phospholene oxides and sulfides are used, but a particularly preferred catalyst is 1-phenyl-3-methylphosphorene-1-oxide.

The method for producing a partially urethanized alicyclic carbodimide according to the present invention will be described in detail below.

First, an alicyclic diisocyanate and an aliphatic alcohol are mixed so that the isocyanate group has an incyanate content of 5% of the initial content.
The product, which is partially urethanized with alcohol by reacting at a ratio of 0 to 9%, preferably 75 to 9%, is converted to 100 to 160% using a carbodimidization catalyst.
It can be obtained by carrying out a carbodimidation reaction at a temperature of 100 ml, followed by urethanizing the isocyanate group resulting from the reaction with alcohol.

Alternatively, it can also be obtained by carbodimidizing an alicyclic diisocyanate with a carbodimidization catalyst and then completely urethanizing the unreacted isocyanate groups with alcohol.

The reaction between an aliphatic alcohol and an alicyclic diisocyanate is an exothermic reaction.

The urethanization of diisocyanate with alcohol is preferably carried out at a temperature not exceeding the boiling point of the alcohol, that is, at a temperature of 45 to 60 qo.

After the reaction between alcohol and diisocyanate is completed, a carbodimidation catalyst is added and heated gradually to a predetermined temperature (
100 to 16,000) to carry out the carbodimidation reaction.
In order to expel the generated C02 from the system, blowing N2 is effective in promoting the reaction. The reaction temperature in this case is 100~
160 qo, a solventless reaction is preferred, but if a solvent is used if necessary, it must have a high boiling point, dissolve the produced carbodimide, and not react with isocyanate groups. Examples of such solvents are ethylbenzene, cumene, chlorobenzene, 0-dichlorobenzene, and the like. The amount of catalyst for carbodimidization varies depending on the type of diisocyanate, but is 0.5 to 1. Skin t% is appropriate. The reaction progress is 2250 skin-1 of the IR spectrum N=
The absorption peaks of C=○ and 2130 skin-1 and N=C=N are tracked. As the reaction progresses, the absorption peak for N=C=○ decreases and the absorption peak for N=C=N increases. The reaction rate is m by DN=C=○ and DN=C=N, which is determined by the half-value method of the absorption peak of N=C=N, assuming N=C=○.
Obtain according to the formula. N=C=N is a carbodiimide group, N
=C=0 represents an isocyanate group. Reaction rate=2×D
N=C=N/2×DN=C=N+and N:Cni.

XIO. ………………'・}Compared to conventional carbodiimides, the partially urethanized alicyclic carbodiimide of the present application has an additive amount of 0.25 to 1.
Its features are that it exhibits excellent hydrolysis resistance even in a small amount of 0% by weight, and secondly, that it has good solubility in polyurethane resins. The present invention will be explained below while comparing with Examples and Comparative Examples.

In addition, parts in the examples represent parts by weight. Example 1 333 parts of mDI was placed in a 500M separable flask equipped with a reflux condenser, a dropper, a thermometer, a dropping funnel with a side tube, and a nitrogen introduction tube, and the flask was purged with nitrogen.

While pouring IPDI, 24 parts of methanol was added dropwise through a dropping funnel with a side pipe to maintain the reaction temperature at 45-50 pm. After completion of the dropwise addition, the urethanization reaction is continued for 3 hours at a temperature of 50 to 55 qo. Next, after measuring the N=C=○ content and confirming the completion of the reaction between IPDI and methanol, 3
．． Three parts of 1-phenyl-3-methylphosphorene-1-oxide (hereinafter referred to as PM 0) is added to carry out a carbodimidization reaction. At that point, a stream of nitrogen is passed through the nitrogen inlet tube to foam the mixture, and the temperature is gradually raised until the internal temperature is about 150 qo. The reaction rate is determined by m〃N=
It can be known from the absorption band of N=C=N when C=○.
DN=C=N obtained from the IR absorption band by the half-value method
, DN=C=0, the reaction rate is determined by {Equation 11.
When the reaction rate is about 95%, the reaction takes about 30 minutes to reach equilibrium.
It's time. After checking the NCO content, unreacted NC
7.7 parts to mask O (unreacted NCO content =
Add 2.96% methanol dropwise from the addition funnel. Since the reaction temperature is as high as 150° C., methanol becomes gaseous, but loss of methanol can be prevented by sufficiently cooling it with a reflux condenser. After confirming that there is no absorption of unreacted NCO groups by IR (
In particular, to remove excess methanol)
Dry for 2 hours at 10 days to obtain the desired product. Melting point 82-85qo, N=C=N%=18.6%, Mn=
758 was obtained as a pale yellow transparent solid.

Example 2 333 parts of IPDI was placed in a 500' separable flask equipped with the same equipment as in Example 1, and the flask was purged with nitrogen.

After adding 1.7 parts of PMPO, the temperature is gradually raised until the internal temperature is about 150 qo.

A decarbonation reaction occurs, and the reaction progresses gradually. The progress of the reaction is determined by IR measurement in the same manner as in Example 1. The NCO content is checked when the reaction rate determined from the absorption band of m reaches 75%. terminating the carbodimidization reaction,
22.6 parts (NC
Met/ol (equivalent to O content = 11.0%) is added dropwise from the dropping funnel. After the dropwise addition was completed, the reaction was carried out at 150°C for 2 hours, and after confirming that there were no unreacted NCO groups by IR,
In order to remove low boiling point components, the desired product is obtained by drying at 150° C./10 boat days for 2 hours. Melting point 72-74o
o, N=C=N content 12.4%, Mn=780 as a pale yellow solid.

The method for obtaining the partially urethanized alicyclic carbodiimide according to Example 1 is called Method A, and the method for obtaining the carbodiimide according to Example 2 is called Method B.

Table 1 shows the composition and properties of carbodimide obtained by methods A and B using various diisocyanates and various alcohols as urethanizing agents.

Table 1. Comparative Example 1 Coestel (hydroxyl value encapsulated average molecular weight 200
0), 45 parts of 1,4-butanediol, 15 parts of diphenylmethane diisocyanate, and 735 parts of dimethylformamide were used as raw materials to prepare an ordinary linear polyurethane resin by a known method.

A free film is created by adding aromatic carposimide to this polyurethane resin.

A dumbbell-shaped specimen for tensile testing (2
No.) was cut out, and the tensile properties were measured after immersing this test piece in 8,000 °C warm water for 9 days. Table 2 shows the nonvolatile content of the above polyurethane resin solution with no addition of aromatic carposimide, 0.25% by weight, 0.5% by weight, and 1% by weight.
．． Normal state physical property values when adding 00% by weight and 8
The tensile properties are shown when immersed in warm water at 0q0 for 9 days.

In Tables 3, 4, and 5 below, a carbodimide compound is added to a polyurethane resin solution to measure physical properties, and the addition ratio of the carbodimide compound is expressed in weight % based on the nonvolatile content of the polyurethane resin solution, as in Table 2. .

Table 2. Note: In Table 2K, 1, 2 and 5 are the same as the sample in Table 1.

Table 2 shows the effect of adding partially urethanized aromatic carbodimide, and although it is effective when compared with the case without addition, there is no one that has a tensile strength retention rate of 80% or more for 9 days at 80:00. Good at best, no. 5 to 1. The retention rate is about 69.1%. Comparative Example 2 Table 3 shows the measurement results of tensile properties when conventional monocarbodiimide compounds and polycarbodimide compounds were added to the linear polyurethane resin of Comparative Example 1.

To the monocarbodiimide compound, 10 parts of 2,6-diisopropylphenylene-1-isocyanate and 2 parts of sodium phenolate were added and heated at 200:00 for about 4 hours.

After the reaction is completed, unreacted isocyanate is removed by distillation, and the reaction product is thoroughly purified using petroleum ether.

The melting point of the reaction product obtained was approximately 470. The polycarposimide compound was prepared by adding 3 parts of 1,3,5-triisopropylphenylene-2,4-diisocyanate and 3 parts of hexamethyltriethylenetetramine at 200°C.
Heat for about 2 hours.

After the reaction is completed, the reaction product is purified in the same manner as for the monocarposimide compound. The melting point of the reaction product obtained was about 195oo. 3. As can be seen from Table 3, if the polycarbodiimide compound is added in an amount of 3 to 4% by weight or more, the tensile strength retention rate will be approximately 75%, but if it is less than 1% by weight, it will not be effective as a water resistance improver.

Also, in the case of a monocarposimide compound, if it is added in an amount of 3 to 4% by weight or more, the tensile strength retention rate will be 81 to 84% and an effect will be produced, but if it is less than 1% by weight, the effect will not be sufficiently obtained. Example 3 Tables 4 and 5 show the results of measuring tensile properties when various partially urethanized alicyclic carbodiimides were added to the linear polyurethane resin of [Comparative Example 1].

4. Remarks: 6, 7, and 10 in Table 4K are the same as the sample images in Table 1. Notes in Table 5K: Shu 8, Secular 9, Statue 11
Table 4 shows the effect of adding partially urethanized carbodiimide based on IPDI.

Compared to conventional mono- and polycarbodiimide compounds, the tensile strength retention rate is 71-86% just by adding 0.25-1.0% by weight, making it a water resistance improver compared to conventional compounds. It seems to be quite effective. Table 5 shows the effect of adding alicyclic carbodimides other than IPDI.

Claims (1)

[Claims] 1. In the production of partially urethanized alicyclic carbodiimide using an alicyclic diisocyanate, an aliphatic monoalcohol, and a carbodiimidization catalyst, 50 to 90 mol percent of the isocyanate groups of the alicyclic diisocyanate are carbodiimidized, and other A method for producing a partially urethanized alicyclic carbodiimide, which comprises subjecting an isocyanate group to a urethanation reaction with an aliphatic monoalcohol.