JPS59226062A - Composition for paint - Google Patents

Abstract

PURPOSE:To provide the titled composition containing a specific blocked polyurethane prepolymer and a polyoxyalkylene polyamine, and giving a coating film having excellent appearance and chipping resistance. CONSTITUTION:The objective composition contains (A) a blocked prepolymer consisting of (i) the one obtained by blocking an isocyanate-terminated prepolymer of tolylene diisocyanate and a polyol with a lactam blocking agent and/or (ii) the one obtained by blocking an isocyanate terminated prepolymer of methylene-bis(cyclohexyl-isocyanate) and a polyol with an oxime blocking agent, and (B) a polyoxyalkylene polyamine.

Description

[Detailed description of the invention] The present invention relates to a polyurethane coating composition.

Currently, cars, especially passenger cars, have three coats: undercoat, intermediate coat, and top coat.
The road is coated with a layer of paint, but in cold regions, salt is sprayed to prevent roads from freezing, so if there is even the slightest scratch on the paint film, rust can form from there, causing problems. Scratches on the paint film are caused by flying stone chips while driving. Therefore, in order to prevent corrosion caused by salts in automobiles, etc., it is necessary to improve the impact resistance of the coating film against flying stones, that is, the chipping resistance. Until now, vinyl chloride-based and melamine-based paints have been considered as chipping-resistant paints, but vinyl chloride-based paints require thick coating and have a poor appearance. The melamine type has insufficient chipping resistance, and no satisfactory product has been obtained yet. In view of these circumstances, the inventors of the present invention have conducted extensive research and have found that
Among the aromatic polyisocyaners F, tolylene diisonanate is used in particular, and a prepolymer having isocyanate groups at the terminals obtained by reacting this with a polyol is blocked with a lactam-based blocking agent and polyoxyalkylene polyamines. It was discovered that a coating film with a good appearance and excellent chipping resistance could be obtained by combining the above. Also, among organic polyisocyanates,
In particular, by using methylene bis (cyclohexyl isocyanate) and reacting it with a polyol to obtain a prepolymer having an isocyanate group at the end, blocked with an oxime-based blocking agent, and the above-mentioned polyoxyalkylene polyamine, the baking temperature can be increased. It was discovered that a coating film with a low surface resistance, a good appearance, and excellent chipping resistance could be obtained, and based on these findings, the present invention was developed. That is, the present invention provides (
1))! J lylene diisocyanate polyol and a prepolymer having an isocyanate group at the end blocked with a lactam blocking agent and/or methylene bis(cyclohexyl isocyanate) and polyol
This is a coating composition comprising (2) a polyoxyalkylene polyamine, which is obtained by blocking a prepolymer having an isocyanate group at the end with an oxime-based blocking agent.

Examples of the tolylene diisocyanate used in the present invention include 2.4-) lylene diisocyanate), 2.6
-) lylene diisocyanate and mixtures thereof.

Polymerized polyisocyanates such as dimers and dimers of the above isocyanates, and positive imide modified products.

A biuret compound can also be used.

The prepolymer having an isocyanate group at the terminal of tolylene diisocyanate and polyol used in the present invention has the above-mentioned tolylene diisocyanate and polyol in MCO
Excess ratio of groups to OH groups (equivalent ratio of about 12 to 5.
It can be obtained by reacting with O).

Examples of the polyol include compounds containing at least two active hydrogen atoms and having a molecular weight of 62 to 100,000. Specifically, for example, polyester polyol-μ, polyether polyol-μ, polyetherester p-polyol, polyesteramide polyol-〃, acrylic polyol-μ, polyurethane polyol-/I/, polycarbonate polyol-μ
, epoxy polyol-μ, epoxy-modified polyol, polyhydroxyalkane, oil-modified polyol-μ, castor oil, or mixtures thereof. The reaction between tolylene diisocyanate and polyol-μ can be carried out in a solvent without active hydrogen or without a solvent.

Examples of solvents without active hydrogen include ethyl acetate, butyl acetate, and cellosoproacetate.

Power! Pitot μ acetate, dimethyl esters of dibasic acids (e.g. succinic acid, glutaic acid, adipic acid, etc.), esters such as ethyl ρ ketone;

Ketones such as methyl isobutyl ketone, toluene, xylene, SOμPETS Φ100. Examples include aromatic solvents such as Solhessosha 150.

When using a solvent, the solid content in the coating composition is about 20 to
It is used in an amount of about 80% by weight. The reaction temperature is about 0~
If necessary, a catalyst such as a tertiary amine, a metal salt, or an organometallic compound may be used at 200°C.

The prepolymer may contain tolylene diisocyanate monomer. Such polyester polio
An example of μ is a reaction product of a polyhydric alcohol and a polybasic acid. Examples of polyhydric alcohols/l/cols include ethylene glyco-μ, propylene glycol-μ, butylene glyco-μ, hexylene glycol-μ, neopentyl glyco-μ
, V chlorohexanedimethanol〃, diethylene glyco-μ
, triethylene glycol, polyethylene glycol-μ,
Dipropylene glyco-μ, polyoxypropylene glyco-μ, polyoxybutylene glyco-p.

Examples include glycero-A/, )rimethylo-μ propane, pentaerythritol, and so-μ pitot μ.

Examples of polybasic acids include succinic acid, adipic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrahydro-7-μ acid, hexahydrophthalic acid, maleic acid, fumaric acid, and acid anhydrides thereof. etc. can be given.

Further, polyester polyols obtained by ring-opening polymerization of lactones such as cabrocton and methylcaprolactone with glyco-ρ are also suitable examples.

Examples of polyether polyols include epoxide compounds such as ethylene oxide, propylene oxide, butylene oxide, tetophhydrofuran, styrene oxide, epichloro hydrin, phenylene glycidyl ether, allyl glycidyl ether, etc. Polymerization is carried out in the presence of a catalyst such as boron, and these epoxide compounds can be prepared singly or in mixtures, or in combination by addition to a reactive hydrogen atom-containing initiator. Examples of reactive hydrogen atom-containing initiators include water, polyols such as ethylene glycol, propylene glycol, glycero, trimethylop-propane, pentaerythritol, sorbitol, and aminoalcohols such as ethanolamine. , and polyamines such as evaporated ethylenediamine.

Examples of polyether ester polyol include those obtained by subjecting the above-mentioned polyether as a raw material to a polyesterification reaction with a polybasic acid, as well as those obtained by a ring-opening copolymerization reaction of an epoxide compound and an acid anhydride. Compounds having both polyether μ and polyester segments in one molecule can be mentioned.

Examples of polyesteramide polyols include raw materials having amino groups such as ethylenediamine, propylenediamine, hexamethylenediamine, xylylenediamine, hydrogenated xylylenediamine, ethanolodiamine, and propanodiamine during the above polyesterification reaction. Obtained by using them together.

Hydroxyl group-containing polymers, commonly referred to as acrylic polyol-μ, are synthesized by copolymerizing a polymerizable monomer containing one or more hydroxyl groups in one molecule and other monomers that can be copolymerized with this monomer. can do. Examples of hydroxyl group-containing materials include hydroxyethyl acrylate, hydroxypropyl acrylate,
Examples of copolymerizable monomers include hydroxybutymu acrylate, trimethylolpropane acrylic acid monoester, their corresponding methacrylic acid derivatives, polyhydroxybutymasate and fumarate. Examples of copolymerizable monomers include acrylic acid, The methyl, ethyl, propyl, buty-, 2-ethylhexyl, methacrylic, maleic, thumaic, itaconic acids and their corresponding esters as mentioned above, such as styrene, α-methylρ styrene. , vinegar, vinyl acid, acrylonitrile, methacrylonitrile, and other vinyl monomers.

As the polyurethane polyol, for example, polyol-μ
and polyisocyanate, which have a hydroxy μ group at the end. Examples of polio-μ include ethylene glycol, propylene glycol, butylene glycol, hexylene glycol-μ, neopentyl glycol/I/, cyclohexane dimetatool, diethylene glycol-μ, triethylene glycol, digfluorene glycol μ, and crystallo. −μ, trimethylolpropane,
Polio-A such as pentaerythritol μ, sobitol
Polymer polyols such as polyester polyol, polyester ether polyol, polyester amide polyol, and polyester amide polyol can be mentioned. Examples of polyisocyanates include tetofumethylene diisocyanate, hexamethylene diisocyanate), 2,6-diisocyanate, methyl caproate 13-isocyanatomethyfi/-3,5,5-)
LimethylcyclohexyμisoV anate, 4,4'
- Methylenebis(V chlorohex Vμ isocyanate).

1.3- or 1.4-bis(isocyanatomethyl/L
') Cyclohexane, methylcyclohexane-2,4-
diisocyanate, m- or p-phenylene diisocyanate, diphenylmethane-4,4'-diisocyanate), 2,4- or 2°6-dylene diisocyanate, 1,3- or 1,4-xylylene diisocyanate, Diisocyanates or dimers of these polyisocyanates, 3
Examples include polyisocyanates such as polymers.

In addition, a portion of the above polyol-μ is ethylenediamine, propylene diamine, hexamethylene diamine, xylylene diamine, bisaminomethylcyclohexane, 3-aminomethylμm3.5.5-)limethylcyclohexane S//I
Products substituted and reacted with amino compounds such as /amines, ethanolodiamines, propatoolamines, etc. can also be used as polyurethane polyol-μ.

An example of epoxy polyol is a condensed epoxy resin obtained by reacting a polyphenol compound or its nuclear hydride with epichlorohydrin. Epoxy ester resins obtained and modified epoxy resins obtained by reacting with alkanolamines can also be used.

Examples of polyhydroxyalkanes include saponified vinyl acetate homopolymers or copolymers with other copolymerizable heptamers having ethylene bonds, and polygetadiene polyols.

Furthermore, in addition to the hydroxyl group-containing compounds having relatively large molecular weights as described above, low molecular weight polyol-y having a molecular weight in the range of about 62 to 400 can be used alone or in combination.

Examples of these low molecular weight polyols include ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, cyclohexane dimetatool, chrysero-/I/I trimethylolpropane, bentaerythritol μ, and diethylene glycol. Examples include recall, triethylene glycol-μ, and dipropylene glycol.

Examples of the lactam blocking agent reacted with the tolylene diisocyanate prepolymer in the present invention include δ-valerolactam, γ-butyrolactam, ε-caprolactam, and β-propiolactam. Especially ε−
Caprolactam is preferred.

The reaction between the tolylene diisocyanate prepolymer and the lactam blocking agent can be carried out in the above-mentioned organic solvent having no active hydrogen or without a solvent. The reaction temperature is about 30 to 200 tE. Catalysts such as tertiary amines, metal salts, and organometallic compounds may be used as necessary.

The amount of blocking agent used is such that all of the isocyanate groups in the prepolymer are blocked.

Aliphatic instead of tolylene diisocyanate of the present invention,
When aromatic aliphatic or alicyclic polyisocyanates are used, the baking temperature becomes too high to put them into practical use. On the other hand, blocking agents other than lactams, such as alcohol-μ
If a blocking agent is used, the curing will be slow, and the phenol-μ
If oxime-based or oxime-based nofloc agents are used, the stability will be poor when mixed with polyoxyalkylene polyamines, and -
It cannot be used as a liquid paint. A balance between curability and storage stability can be achieved only when tolylene diisocyanate and a lactam blocking agent are combined.

In the present invention, in addition to the prepolymer having an isocyanate group at the terminal of tolylene diisocyanate and polyol-μ blocked with a lactam blocking agent, A prepolymer having an isocyanate group blocked with an oxime blocking agent can also be used. A prepolymer having isocyanate groups at the terminals is obtained by reacting methylene bis(cyclohexyl isocyanate) topolyol in a ratio in which NGO groups are in excess of OH groups (about 1.2 to 5.0 in equivalent ratio). be able to. Here, as methylene bis(cyclohexyl isocyanate), tiJ'2.4'-methylene bis(cyclohexyl isocyanate)'), 4
, 4'-methylenebis(cyclohexyl isocyanate), or a mixture thereof.

The polyol contains at least two active hydrogen atoms similar to those used in producing the prepolymer having isocyanate groups at the terminals of tolylene diisocyanate and polyol-μ, and has a molecular weight of 62 to 100,000. Examples include compounds.

The reaction between methylene bis(cyclohexyl isocyanate) and a polyol can be carried out in the above-mentioned active hydrogen-free solvent or without a solvent. The reaction temperature is about 30
A catalyst such as a tertiary amine, a metal salt, or an organometallic compound may be used as necessary at a temperature of -200°C. The prepolymer may contain a methylene bis(cyclohexyl isocyanate) monomer.

Examples of oxime-based blocking agents for reacting methylene bis(cyclohexy isocyanate) and polyol with a sulfure polymer having isocyanate groups at the terminals include formamide oxime, acetaldoxime, acetoxime, methyl to ethyl toxime, and methyl isopropymu ketoxime. , methylisobutymu-ketoxime, diethylketoxime.

Examples include diacetyl monooxime, benzophenone oxime, and cyclohexanone oxime.

Particularly preferred are methyl ethyl ketoxime, methisobutyl ketoxime, and cyclohexanone oxime.

The reaction between the prepolymer of methylene bis(cyclohexyl isocyanate) and polyol-μ having an isocyanate group at the end and the oxime blocking agent can be carried out in the aforementioned organic solvent having no active hydrogen or without a solvent. Usually, a method is used in which a blocking agent is gradually added to the isocyanate component. Reaction temperature is approximately 0~100℃
That's about it. Although the reaction between the isocyanate group and the blocking agent is very fast, catalysts such as tertiary amines, metal salts, and organometallic compounds may be used if necessary.

The amount of blocking agent used is such that all of the isocyanate groups in the prepolymer are blocked.

In addition, methylene bis (cyclohexyl isocyanate)
If aromatic polyisoneanate is used instead, the stability after mixing with polyoxyalkylene polyamine is poor and it cannot be used as a paint for exile. Further, when an aliphatic or alicyclic isocyanate other than methylene bis(cyclohexyl isocyanate) used in the present invention is used, curing is slow and cannot be used. Furthermore, blocking agents other than oxime-based ones, such as alcohol-based and lactam-based ones, are slow to cure, and phenol-based and imine-based blocking agents are too unstable to be used. Only when combined with a methylene bis(cyclohexyl isocyanate) toxime blocking agent can a balance between curability and storage stability be achieved.

In the present invention, a prepolymer of tolylene diisocyanate and polyol-μ having an isocyanate group at the end is glocked with a lactam blocking agent, and methylene bis(
A mixture of cyclohexyl isocyanate) and a prepolymer of polyol having isocyanate groups at the end and teplocked with an oxime-based blocking agent may be used. The mixing ratio of the former blocked polyisocyanate is about 30-95 to about 5-70 of the latter blocked polyisocyanate in terms of weight ratio.

When block polyisocyanates are used in combination, the baking temperature ranges from low to high temperatures, and coatings with superior physical properties can be obtained. Further, it is particularly preferred since it has advantages such as improved adhesion with the undercoat and topcoat.

The polyoxyalkylene polyamine used in the present invention includes, for example, ethylene glycol and propylene glycol.
, diethylene glycol, chrycerin, trimethylo-μ
propane, triethano-μamine, pentaerythritol) α-methip-glucoside, ethylene diamine,
Polyoxyalkylene diols obtained by addition polymerization of alkylene oxides (e.g., ethylene oxide, propylene oxide, butylene oxide, etc.) to initiators such as diethylene triamine, polyether polyols such as trio-μ, and tetraols are terminated by, for example, ammonolysis. The hydroxyl group of is changed to an amino group.

Specific examples of polyoxyalkylene polyamines include those derived from polypropylene glyco-IVi or triols, where n is about 2 to 100. ] or [in the formula,
x+y+z is about 3-5o. ] Polyoxypropylene polyamines represented by:

Polyoxyalkylene polyamines may be used as they are, but they can also be used as ketimines or enamines by reacting them with ketones. By ketimination or enamination, the storage stability, compatibility and dispersibility of 9M materials, etc. of the composition are further improved. Examples of ketones used for ketimination or enamination include aliphatic, aromatic, and alicyclic ketones such as methi μ ethyl ketone, diethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, acetophenone, and benzophenone. In addition, the above-mentioned polyoxypropylene diamine can be used in combination with polybasic acids such as dimer acids and polymers having epoxy groups.
Alternatively, a portion of the reaction may be performed with a resin or the like. When reacted with a polybasic acid, the water resistance and scorchability of the coating film are improved.

Chemical resistance of coatings when reacted with epoxy groups.

Adhesion properties are further improved.

The blending ratio of the above-mentioned blocked polyisocyanate and polyoxypropylene diamine is block isocyanate) M
number and number of active hydrogen groups is about α1-10, preferably about 0.2
~5. More preferably, it is about 0.4 to 2.0.

When carrying out the present invention, pigments are used as necessary.

Dyes, leveling agents, anti-sagging agents, catalysts, stabilizers, etc. may be used in combination.

The composition thus obtained is useful as a chipping-resistant paint.When coating, it is applied to the object using a spray can, roll coater, or flow coater, and then baked to release the blocked isocyanate and amino groups. The reaction causes cross-linking, resulting in a strong film that is flammable. The resulting coating film shows no so-called discoloration, no thermal deterioration, no foaming, and has a good appearance.It has excellent impact resistance, as well as low-temperature processability, water resistance, and moisture resistance.

It also has good chemical resistance and is used, for example, as a paint for automobiles.

The present invention will be explained in more detail below with reference to Examples and Comparative Examples.

Example 1 Tolylene diisocyanate (2,4 body/2.6 body-80
/20) 174.2f, cerosophore) 373.
29 to 70-75°C and polytetofumethylene ether! Glyco-Iv (molecular weight 1000; ketone hydrofuran was used as the alkylene oxide) 2509 g and trimethylo-propane 22.4 g were added dropwise over about 1 hour. After further reaction at 75-80°C for 3 hours, ε-caprolactam 11! When M and Tetopti 1.3-diacetoxydistanoxane 0.289 μm were added and the reaction was continued for 4 hours at a temperature of 75 to 80 μm, the NGO group disappeared.

Thus, the recycled isocyanate group content is 4.5%.

A blocked polyisocyanate solution with a solid content of 60% was obtained. Add polyoxypropylene triamine (molecular weight approximately 500; Diefermin T-403 manufactured by Mitsui Texaco Chemica) to 933 g of this block polyisocyanate solution.
s2g, precipitated barium sulfate 361 f, riμri 36
04F and 1 g of carbon were mixed and uniformly dispersed using a 3-row micrometer to obtain a coating composition. This composition was placed on a mild steel plate for 1
Apply to a film thickness of 30 to 150μ, 140μ×
After baking for 30 minutes, a tough coating film was obtained. The coating film performance is shown in Table 1. Note that this composition was stable at 45° C. for 30 days.

Example λ 4.4'-methylenebis(cyclohexyμ isocyaner)) 262.4f, force μ pitot μ acetate 410.4
f and diptyltin dilaure) 0. : 1 was heated to 80°C, and polybutylene adipate (molecular weight 1000i Takelac U-2410 Takeda Pharmaceutical Co., Ltd.) 2509 and 1 were added.
．． 226 g of 3-butylene glyco-μ was added dropwise over about 1 hour. After further reacting at 80-85°C for 3 hours, 3
Cooled to 0 t, followed by methyethioketoxime 91
．． 59 was added dropwise. When the reaction was further carried out at 65 u for about 1 hour, the NGO group completely disappeared.

In this way, a blocked polyisocyanate solution with a regenerated NCO group content of 4.1% and a solid content of over 60 was obtained.

This block polyisocyanate solution 10369, polyoxypropylene diamine (molecular weight 500; diefermin D-400 manufactured by Mitsui Texaco Chemical) 2451
1. Precipitated barium sulfate 433, Riμri 4329. 1 g of carbon was mixed and uniformly dispersed using three rolls to obtain a coating composition.

This composition was coated on a mild steel plate to a film thickness of 130 to 150 μm and baked for 30 minutes at 440 tl to obtain a tough coating film. The coating film performance is shown in Table 1. This composition is stable for 30 days at 45°C.

Example 3 The epoxy group disappeared when the same polyoxyprobilexy (1801F) as used in Example 1 was reacted at 70° C. for 4 hours. This polyamine resin is 3339.5 il! Blocked polyisocyanate solution of Example λ 10369. Precipitated barium sulfate 477g, riμri 4769. One ton of carbon was mixed and uniformly dispersed using three rolls to obtain a coating composition. This composition was applied onto a mild steel plate of 130 to 150 JI.
When coated to a film thickness of E and baked for 140 mm x 30 minutes, a strong @'& coating film was obtained. The coating film performance is shown in Table 1.

This composition was stable for 30 days.

Example 4.4'-methylenebira (cyclohex: Jfi/isocyanate) 262.49. Calpitol acetate 43
5g and 80t of dibutyltin dilaure) 0.39
250f and 1,3-butylene glycol/l/2 of the same polybutylene adipate as used in Example λ.
2.69 was added dropwise over about 1 hour. Further 80-8
After reacting at 5C for 3 hours, the mixture was cooled to 40C, and then 1179 tons of methylisobutymu-ketoquine was added dropwise. When the reaction was further carried out at 65° C. for about 1 hour, the NGO groups completely disappeared.

Thus regenerated 1fcO group content 3.9g6. Solid content 60%
A blocked polyisocyanate solution was obtained.

This blocked polyisocyanate solution 1077f, polyoxypropylene triamine 1621F.

Precipitated barium sulfate 4049. Riμri 4031F.

1 g of carbon was mixed and uniformly dispersed using three rolls to obtain a coating composition. This composition was coated on a mild steel plate with 130 to 1
It was applied to a film thickness of 50 μm and baked at 140° C. for 30 minutes. The coating performance is shown in Table 4.

Example: 673 g of the blocked polyisocyanate of Example 1, 288 q of the blocked polyisocyanate of Example λ, and 162 g of polyoxypropylene triamine.

Precipitated barium sulfate 369f, Riμri 368f.

Carbon If was mixed and uniformly dispersed using three rolls to obtain a coating composition. This composition was applied onto a mild steel plate at 130-15
It was applied to a film thickness of 0μ and baked at 140tEx for 30 minutes. The physical properties of the coating film are shown in Table 1.

Comparative Example 1 Tolylene diisocyaner) (2,4 body/2,6 body-80
/20) 17429 to 7rosoμpoacetate) 297.5
9 and added 0.0899 g of dipetitic μtin difurate. Heat this solution to 75°C and heat it to 75°C. A mixture of 162.5 f of Clicor/l'1 molecular weight 650) and 224 f of trimethylo-μ propane is added dropwise over 1 hour.

After the addition of the mixture was completed, the mixture was further heated to 75 to 80° C. at 3 hours. Subsequently, 87.19 ml of methyμethylketoxime was added dropwise over 1 hour. When the mixture was further heated to 65 to 75° C. for 1 hour after the addition of methyμethyμketoxime, the NGO Foundation Fund was completely lost. Thus the recycled incyanate group content!
A blocked polyisocyanate solution with L6% and solid content 60% was obtained.

This solution 750f Ketiminated polyaminopolyamide 261g Precipitated barium sulfate 3039ml
302f carbon
1g*Amine value 286. Polyaminopolyamide with a viscosity of 18,000 cpa was ketiminated with methyl isobutyl ketone and uniformly dispersed using three rolls to obtain a coating composition. This composition was coated on a mild steel plate to a thickness of 130-150μ and baked at 140tC for 30 minutes to obtain a coating film with slight foaming. The first priority is the coating performance and stability of this composition.
Shown in the table.

Comparative example λ Tolylene diisocyanate (2,4 units/2.6 units = 80
/20) 174.29 to cellosolve acetate) 302.
11 and heated to 75'C. Add polytetramethylene ether glycol μ (molecular weight 650) 16 to this solution.
A mixture of 2.5 g and 22.49 g of trimethylo-ppropane was added dropwise over 1 hour. After the addition of the mixture was completed, the mixture was heated to 75-85° C. for an additional 3 hours. followed by pheno-/l
94.1 g of tetrabuty/I/-1,3-diacetoxydistanoxane were added and heated for 5 hours at 75-80°C, and the NGO groups completely disappeared. In this way, a blocked polyisocyanate solution with a content of regenerated isocyanate groups of over 5.6 and a solid content of 60% was obtained.

This blocked polyisocyanate solution: 750g Ketiminated polyaminopolyamide similar to that used in Comparative Example 1: 261g Precipitated barium sulfate
303g talc
3029 carbon
1 g was uniformly dispersed using three rolls to obtain a coating composition. This composition was applied onto a mild steel plate to a thickness of 130 to 150 μm and baked at 140° C. for 30 minutes to obtain a foamed coating. The first priority is the coating performance and stability of this composition.
Shown in the table.

Comparative Example 3 262.49 of 4.4'-methylenebis(cyclohexyμ isocyaner) was dissolved in 373.79 of cellosolve acetate, and 0.112 g of digtyltin dilauret was added. This solution is heated to 75° C. and a mixture of polytetramethylene ether glyco-/l/(molecular weight 650) 162.51 F and trimethylolpropane 22.49 F is added dropwise over 1 hour. After the completion of dropping the mixture, another 3 hours 75 ~
Heat to 80°C.

Subsequently, ε-caprolactam 113.29 was added to 80~
After heating at 85 tlK for 10 hours, the NGO groups completely disappeared. In this way, a 10-pack polyisocyanate solution with a regenerated isocyanate group content of 4.5% and a solid content of 6096 was obtained.

This block polyisocyanate solution Ketiminated polyaminopolyamide similar to that used in 9339 Comparative Example/
261g precipitated barium sulfate
357friμri
356g carbon
A coating composition was obtained by uniformly dispersing 1 g with a three-row micrometer. This composition was coated on a mild steel plate to a thickness of 130 to 150 μm and baked at 140° C. for 30 minutes to obtain a tacky coating. The coating performance and stability of this composition are shown in Table 1.

Comparative Example 4. 262.4 g of 4'-methylenebis(cyclohexyl isocyanate) was dissolved in cellosolve acetate 360.9 V, and 0.108 g of dibutylene/l/a dilauret was added. This solution was heated to 751E and polytetramethylene ether glyco-1v (molecule ('i 625 '')
A mixture of 162.5 g and 22.4 g of trimethylolpropane is added dropwise over the course of 1 hour. After the addition of the mixture is completed, the mixture is heated to 75-80° C. for an additional 3 hours.

Subsequently, pheno-/I/94.11 was added and heated at 80 to 85°C for 10 hours, and the NGO groups completely disappeared.

Thus, the regenerated isocyanate group content 4. r96. A Glock polyisocyanate solution with a solids content of 60% was obtained.

This block polyisocyanate solution: 894gKetiminated polyaminopolyamide similar to that used in Comparative Example/
2619 Precipitated barium sulfate
346g talc
345g carbon 1g
was uniformly dispersed using three rolls to obtain a coating composition. This composition was coated on a mild steel plate to a thickness of 130 to 150 μm and baked at 140° C. for 30 minutes, resulting in a slightly foamy coating. The coating performance and stability of this composition are shown in Table 1.

Table 1 1) After dropping 2 kg of iron WM-5 nuts from a height of 2 m onto a coating film inclined at 45 degrees, a 24-hour crane spray test is carried out.

2) Leave it for 10 days at 50°C and 98g6RH to observe changes in appearance.

3) Soak in 40°C warm water for 10 days and observe changes in appearance.

4) Soak gauze with ethyl acetate and perform a rubbing test to check the appearance of the coating film.

Claims (1)

[Claims] (1)) A prepolymer of lylene diisocyanate and polyol having an isocyanate group at the end is blocked with a lactam blocking agent and /l 7'c
A prepolymer of hamethylene bis(cyclohexyl isocyanate) and polyol having an isocyanate group at the end is blocked with an oxime-based blocking agent (2
) A coating composition containing polyoxyalkylene polyamine