JPS58132019A - Production of urethane prepolymer - Google Patents

Abstract

PURPOSE:To produce an NCO group-terminated urethane prepolymer which can provide in good workability, films excellent in weather resistance, by reacting a low-MW polyol with an excess amount of a specified polyisocyanate. CONSTITUTION:As a polyisocyanate component, there is used a bis(isocyanatomethyl)tricyclo[5,2,1,0<2.6>]decane (TCDDI), e.g., 3,8-bis(isocyanatomethyl)tricylo[5,2,1,0<2.6>]decane). Namely, a urethane prepolymer is obtained by polymerizing a low-MW polyol (e.g., trimethylolpropane) and TCDDI in an amount of about 1.5-15 times, by weight, that of the polyol, at about 0-150 deg.C in the presence of about 0.005-5wt%, based on TCDDI, catalyst (e.g., dibutyltin dichloride) and then removing the excess TCDDI.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a urethane prepolymer having an NGO group at its end.

Currently, there are many urethane paints on the market, but the ones that are considered non-yellowing are those made from hexamethylene diisocyanate (hereinafter abbreviated as HDI).
Those made from 1,3-bis(incyanatomethyl lv)cyclohexane (hereinafter abbreviated as H6XD) and 3-isocyanatomethyl-3,5,5-)limethylcyclohexyl isocyanate ( It is roughly divided into those using IPDI (hereinafter abbreviated as IPDI) as a raw material. HDI-based urethane prepolymers not only have poor compatibility with polyols and the like and dilubility with solvents, but also have poor drying properties at low temperatures, especially in winter, which may cause practical problems. Although H6XDI urethane polymers have good compatibility with polyol-μ, etc., satisfactory results have not been obtained in terms of drying properties at low temperatures. IPDI-based urethane prepolymers have good compatibility and drying properties at low temperatures, but poor coating performance. Therefore, attempts have been made to improve the above drawbacks by mixing two or more types of urethane prepolymers, but it is extremely foolish to only highlight the advantages of each urethane prepolymer, and drying properties at low temperatures are still not good. , urethane prepolymers with good coating performance have not been obtained.

In view of these circumstances, we conducted intensive research on a method for producing a urethane prepolymer with improved drying properties at low temperatures and good coating performance.As a result, we found that bis(isocyanatomethyl/L/)tricyclo(5,2゜6 1.0') A urethane prepolymer having NCO groups at the end obtained by reacting decane (hereinafter abbreviated as TCDDI) and a low molecular weight polyol with an excess of NCO groups is
We discovered that it has excellent solubility in solvents and polyol components for paints, has excellent drying properties at low temperatures, and provides excellent coating performance in terms of weather resistance and other properties. Based on this knowledge, we have completed the present invention.

That is, the present invention provides bis(isocyanatomethy/&)
This is a method for producing a urethane prepolymer having an NGO group at the end, which is characterized by reacting lycyclo(5,2,1,0""6]decane with a low molecular weight polyol in an excess of NCO groups.

Examples of TCDDI used in the present invention include 3,
8-bis(isocyanatomethy1v))licyclo(5,
2,1,0') decane, 3,9-bis(isocyanatomethyl/L/)tricyclo[5°2.1.02+
6) Decane, 4,8-bis(isocyanatomethyl)tricyclo[5,2,1,02.6]decane, 4,9-bis(inocyanatomethyl)tricyclo(5,2,1,
0') decane and mixtures thereof.

The low molecular weight polyol used in the present invention is a polyol having a molecular weight of about 62 to 500, specifically, for example, ethylene glycol, 10 pyrene glycol-A/1.
3-Butylene glyco-iv, l.

6-hexanediol, diethylene glyco-1v.

Dipropylene glycol, neopentyl glycol, triethylene glycol/l/, water m bisphenol/l
/A, xylylene glyco-A/, 1,4-butylene glycol, dihydric alcohols such as bisphenol dihydroxypropyl ether, 7 (e.g. glycerin, trimethylolethane, trimethylolpropane, 1,2.6
Examples include trihydric alcohols such as -hexanediol, tetrahydric alcohols such as pentaerythritol, and the like. These can be conveniently used alone or as a mixture of two or more. Among the above-mentioned low molecular weight polyols, trimethylo-propane are particularly preferred.

In the present invention, TCDDI and low molecular weight polio-μ are combined into NCO
React with excess groups. Any ratio may be used as long as there is an excess of NCO groups, but the equivalent ratio of TCDDI to low molecular weight I polyol is preferably about 1.5 to 15, particularly about 4 to 10.

The reaction between TCDDI and low molecular weight polyol can be carried out without a solvent, and even with a solvent that does not have active hydrogen (
For example, ethers such as ethyl acetate, butyl acetate, ethers such as ethyl acetate, butyl acetate, dioxane, etc.
Dimenalformamide.

It can also be carried out in Ami-F threads such as dimethylacetamide, ketone solvents such as methyl ethyl ketone). The reaction temperature is about 0 to 150°C, preferably about 20 to 90°C.
It is about ℃.

When reacting TCI) III with a low molecular weight polyol, a tertiary amine or an organometallic catalyst, which is commonly used in the polyurethane field, may be added.

Examples of the catalyst include triethylamine, triethylene diamine, distanoxanes such as tetrahtyltin dichloride, dibutyltin dichloride, dibutyltin oxy-F, dibutyltin diurate, stannous octylate, Examples include lead benzoate, lead naphthenate, iron acetyl acetonate, cobalt benzoate, zinc 2-ethylhexanoate, zinc naphthenate, and organic braiding catalysts are particularly preferred. The amount of catalyst involved is TC
Approximately 0.005 to 5 coulometric % relative to DDI, particularly approximately 0.0
Approximately 3 to 2 weight t% is preferable.

If a solvent is used in the reaction between TCDDI and low molecular weight polyol, it is removed by distillation or the like.

If it is necessary to remove unreacted TCDDI from the reaction solution, it may be removed by, for example, an extraction method, a distillation method, a chromatography method, or a combination thereof.

In the case of the extraction method, the difference in solubility in the extractant of the adduct of low molecular weight polio-μ and TCDDI and unreacted TCDDI is utilized.

As the extractant, aliphatic reconstituted water purple is used.

Among these aliphatic reverted hydrogens, particularly those having a boiling point of about 50 to 10
A temperature of about 0°C is preferable, and specifically, for example, n-
hebutane, n-hexane, ligroin, n-octane,
3-methylpentane, 3-ethylpentane, petroleum benzene or a mixture thereof is used.

Since both the generated adduct and unreacted TCDDI have good solubility in organic solvents, it is extremely difficult to remove only unreacted TCDDI with an extractant and obtain the desired prepolymer with high purity in a good yield. For this purpose, it is preferable to carefully select the type of extractant, etc.

From this point of view, among the above extractants, 4, especially n
- hexane alone or n-hexane at about 8% by weight
A mixed solution of n-hexane-ethyl acetate of 0% or more to less than 100% is preferred, especially n-hexane (approximately 85-95%
A mixed solution of ethyl acetate (about 15 to 5% by weight) is more suitable1, and the extraction temperature is about 15 to 60°C, preferably about 30 to 40°C. The extraction operation is carried out by a conventional method, and may be a continuous method or a 4-batch method. In the case of a continuous method, the extraction agent is used in an amount of about 1 to 4 times, preferably about 2 to 3 times, the amount of the reaction product that is placed directly. , about 2 to 6 for batch type
Double the amount, preferably about 3 to 5 times the amount. The unreacted TCDDI extracted into the extractant can be reused for the reaction with a low molecular weight polyol after the extractant is removed by an operation such as distillation.

When using a distillation method, a patch method can be used, but in order to prevent deterioration due to heating during distillation, it is preferable to use a continuous thin film distillation method, which has a relatively short residence time. Specifically, for example, if the reaction solution is heated to about 160 to 220'C under a vacuum of about 105 g*ag or less and continuous membrane distillation is performed, unreacted TCDDI remains at about 5% by weight or less. can be removed. The removed unreacted TCDDI can be reused for the reaction.

Examples of the chromatographic method include column chromatography, thin layer chromatography, and paper chromatography. The operation method is generally similar to the separation and purification of compounds in the field of chemistry. It is preferable to carry out these operations under a nitrogen atmosphere as quickly as possible.

The urethane prepolymer thus obtained has an NGO group at the end and an amine equivalent of approximately 240 to 400. Excellent solubility in organic solvents,
For example, it is soluble in ethyl acetate, butyl acetate, celloproacetate, benzene, toluene, xylene, methyl ethyl ketone, and the like.

The urethane prepolymer obtained by the method of the present invention is generally diluted with a solvent and used as an isocyanate component of a two-component urethane paint, but it is usually diluted with ethyl acetate to form a solution with a solid content of about 20 to 75% by weight. It is used by mixing with the polyol component for urethane paints.

In addition, the above urethane prepolymer is compatible with a wide range of polyols used as polyols for urethane coatings, such as polyester polyols, polyether polyols, acrylic polyols, polyester ether polyols, and oil-modified polyester polyols. It is uniformly compatible with these polyols and gives a transparent surface. The 7cm material obtained from this enamel containing pigments dries to the touch and hardens quickly, and when used for car 4-pieces, there is less dirt and dust attached even at low temperatures. After painting, the masking tool 7゛ can be used in a short period of time, and there is no smearing even when the coating is applied with salt, so it has excellent flame-fixing workability. In addition, the performance of the dried film is excellent, especially the impact resistance of 111Ft#, the dry film is not peeled off by flying pebbles, and the drying property is also excellent.

Next l! Ill? The present disclosure will be explained more specifically with reference to Examples and Comparative Examples. In the dormitory example and ratio 1 example, part indicates the heavy lid part, and % indicates *m%.

Dormitory Example 1 3.8-bis(isocyanatomethyl)tricyclo(5
,2,1,0')decane(3,8-TCDDI)2
00 parts was heated to 80° C., and 10.4 parts of trimethylo-μ propane (NC010H equivalence ratio −7.0) was added to the solution in 1 portion under stirring for 30 minutes. View - [Additional 80-85 after finishing
'C was continued to be heated and stirred for 3 hours. This reaction solution was added to 0.5
Unreacted 3°9-TCDDI was removed by continuous thin film distillation at about 170-175° C. under reduced pressure of mHg. Free 3,8-TCDDI contained in the residue was measured by Gelber Muei V-chromatography (GPC) and found to be 0.5%. The solid content of the residue is 75%.
Add ethyl acid so that it dissolves uniformly. The amine equivalent weight of this prepolymer solution was 420.

This prepolymer solution has extremely high solubility in organic solvents and can be diluted infinitely with ethyl acetate, butyl acetate, benzene, toluene, xylene, methyl ethyl ketone, isobutyl ketone, etc.

The solubility of the urethane prepolymer solution obtained here is compared with other prepolymers for urethane paints.
A solvent was added to oaU fat (all solids 75%), and the volume (dilution) until it became cloudy was measured. The result is the first
Shown in the table. However, as other urethane paint prepolymers, 3,8-TCDDIK can be replaced with 7-hexamethylene diisocyanate (HDI), ω,ω'-diisocyanate)-1,3-dimethylbenzene (XD Engineering), respectively. In Table 1, they are abbreviated as HDI yarn and XDI yarn, respectively.

Table 1 Dilution rate (%) of resin for urethane coatings In order to compare the compatibility of the urethane and repolymers obtained with polyol components or with known additives with other prepolymers for urethane coatings, 1 part resin (all solids content 75%) and acrylic polyol Ataridic A-801 (manufactured by Dainippon Ink & Chemicals Co., Ltd., solids content 50%, OHHSO 33 parts or cellulose acetate butyrate <KAB 551-0.2) Add 3 parts of 20% solids methyl isobutyl ketone solution (manufactured by Eastman Kodak Company), stir well and check its appearance. The results were as shown in Table 2.

In Table 2, the meanings of the prepolymer symbols are the same as in Table 1.

It can be seen that the products of the present invention are excellent in both compatibility with polyols and compatibility with additives.

Table 2 Compatibility of acrylic polyol/with EAB Coating film (
PVC35%) was created.

In particular, here, a product obtained by carrying out the same operation as in the present invention using H5XDI (1,3-bisisocyanatomethylcyclohexane) is listed as a comparative example as a H6MDI system. Examine the 11114 weatherability of the coating film by irradiating it with ultraviolet rays,
The results of comparison with other coatings are shown on N.B. Varnish (N, B,
It is shown in Table 3 in units of The HDI system and XDI system in Table 3 are the same as those in Table 1.

As shown in Table 3, the coating film using the urethane preglymer of the present invention is stable against ultraviolet rays and is particularly resistant to yellowing. This can be clearly seen from the values of Δb and ΔE.

Example 2 200 parts of 3.8-TCDD was heated to 80-85°C,
While stirring, 7.1 parts of glycerin (NGO10H equivalent ratio -7.7) was added dropwise over 1 hour. After completion of dripping, 80-8
Heating was continued with stirring to 5° C. for an additional 5 hours. After the reaction, unreacted 3.8-TcD was removed using the same method as in Example 1.
nIt-removed. Free 3.8-T contained in the residue
CDDI was 0.7%. Ethyl acetate was added to the residue so that the solid content was 75%, and the mixture was uniformly dissolved to obtain a clear prepolymer solution having an amine equivalent of 425.

Example 3 3.8-TCDDI 200 parts t-Neoplier dissolved while stirring at 80-85°C - Glyco A/1
6.9 parts (NGO10H equivalent ratio = 5.1) was added dropwise over 1 hour. After the dropwise addition was completed, heating was continued at 80 to 85°C for an additional 3 hours with stirring.

Unreacted 3,8-TCDDI was removed in the same manner as in Example 1 to obtain a residue. Free 3,Q- contained in the residue
TCDDI was 0.7%. Ethyl acetate was added to the residue so that the solid content was 75%, and the mixture was dissolved in a ladle to obtain a clear prepolymer solution with an amine equivalent weight of 415.

Example 4 Acrylic polyolefin obtained by copolymerizing the urethane polymer obtained in Examples 1 and 2.3 with 45 parts of styrene, 45 parts of methyl methacrylate, and 10 parts of 2-hydroxyethyl methacrylate Solid content 50%, 0H (
The performance of the coating film was investigated in combination with ii [i 20 ). Table 4 shows the results. The coating film test was conducted after being left at 45° C. for 3 days after application.

Table 4 Example 5 To 200 parts of mixed TCDDI, 0.04 part of Dipty yv@jJ, Dilaure) was added and heated to 80°C. To this, 10.4 parts of molten trimethylo-/L/10 bread was added dropwise over 1 hour with stirring. The NC010H-equivalent ratio at this time was 7.0. After the dropwise addition was completed, heating and stirring at 75 to 80°C was continued for 3 hours. Contained in the reaction solution and unreacted
'CDDI was extracted and removed using a mixed extractant of n-hexane/ethyl acetate = 90/10. The free 'I'CDDI contained in the residue was 0.8%.

An ethyl acetate solution of a prepolymer with a solid content of 75% was obtained in the same manner as in Example 1. Amine equivalent Fi425 of this solution
Met.

Comparative Example 1 Methyl 3-isocyanato/%/-200 parts of 3,5,5-trimethylcyclohexyl isocyanate (IPDI) and dibutyl lv&! Add 0.04 part of diwolate, 80
heated to ℃. To this, 11.5 parts of gmt trimethylolpropane was added dropwise over 1 hour while stirring. NC at this time
010H is 7.0. After the completion of dripping, add another 75 to 80
The mixture was heated and stirred at ℃ for 3 hours. Unreacted IPDI was removed in the same manner as in Example 5. Free IPDI contained in the residue was 0.8%. This residue has a solid content of 75
% of ethyl acetate and uniformly dissolved.

The amine equivalent weight of this prepolymer solution was 380.

Comparative Example 2 0.04 part of diptyltin dilaurate was added to 200 parts of hexamethylene diisocyanate (HDI) and heated to 80°C. Trimethylolpropane molten in this 15
．． 2 parts were added dropwise over 2 hours with stirring. NC01 at this time
0H is 7.0. After dropping, further heat to 75-80℃
The mixture was heated and stirred for 3 hours. Unreacted HD was removed in the same manner as in Example 5. Free H contained in the residue
D-type was 0.4%. Ethyl acetate/V was added to this residue so that the solid content was 75%, and the mixture was uniformly dissolved.

The amine equivalent weight of this prepolymer solution was 325.

Example 6 The coating film performance was investigated when the urethane prepolymers obtained in Example 5 and Comparative Examples 1 and 2 were applied in combination with the same acrylic polyol as in Example 4. Table 5 shows the results. In the coating film test, the solvent resistance and pencil hardness of the coating film was examined after 7 days had passed at room temperature after application.

(Margin below) (Note 1) Apply masking tape for painting 1 after 5 hours of painting.
After applying the tape for 5 minutes, remove the tape and visually check the condition of the painted surface (presence or absence of adhesive residue).

(Note 2) Drop ethyl acetate onto the LCC coating, rub it 10 times, and visually judge the condition of the coating.

In the table, ◎ means very good, ○ means good, △ means slightly poor, and × means poor.

As is clear from Table 5, the paint using the urethane prepolymer of the present invention is not only dry to the touch and dry to the touch better than IPDI yarn, but also far more dry than HDI yarn, which is said to cure faster. It can be seen that the solvent resistance of the coating film 4 is clearly excellent.

Claims (1)

[Claims] Bis(incyanatomethy/I/)tricyclo[5゜2
．． 1,0') decane and a low molecular weight polyol are reacted with an excess of NCO groups.
A method for producing a urethane prepolymer having an O group.