JP2001262010A - Energy-ray-curable composition for powder coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an energy-ray-curable composition which gives a cured coating film excellent in hardness, smoothness, thermal yellowing resistance, etc., and is useful for powder coating. SOLUTION: This composition comprises (A) a compound having at least two maleimide groups and (B) an ethylenically unsaturated compound copolymerizable with maleimide groups, is prepared by melt blending compound A with compound B, and has a softening point (by the ring and ball method) of 60-130 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a compound containing two or more maleimide groups and a compound containing an ethylenically unsaturated double bond copolymerizable with the maleimide group contained in the maleimide compound. The present invention relates to a specific property composition for energy ray-curable powder coating containing as an essential component. The composition for a powder coating of the present invention can be used for preparing a powder coating useful for coating various substrates such as metals, various inorganic bases, plastics, and wood bases. .

[0002]

2. Description of the Related Art Conventionally, thermosetting paints obtained by blending a curing agent with resins containing various functional groups have been used as crosslinkable powder coatings. However, in such a powder coating, it takes 140 minutes to obtain a sufficiently cured coating film.
It is necessary to bake at a high temperature of not less than ℃, and there is a problem that it is generally not suitable for coating of plastic products and wood products having low heat resistance.

On the other hand, since it can be cured at a low temperature, a composition for powder coating which can be applied to a substrate having low heat resistance as described above is disclosed in JP-A-8-176472. Of unsaturated polyester resin and (meth)
A composition containing an acryloyl group-containing polyurethane resin as an essential component and capable of undergoing radical polymerization crosslinking by heating or crosslinking by irradiation with active energy rays has been studied. EP 0 636 669 A2 discloses an active energy ray cross-linking type powder coating for a powder coating comprising a resin having a specific property of an unsaturated group and a cross-linking agent containing a vinyl ether group, a vinyl ester group or a (meth) acryloyl group. A composition is disclosed.

However, in a powder coating containing the active energy ray-crosslinkable composition as described above, the softening point of the composition is set to a thermosetting type in order to sufficiently flow at a low temperature to obtain a smooth coating film. Although it is necessary to set the temperature significantly lower than that of the composition for powder coating, the softening point cannot be lowered much in order to maintain the blocking resistance at a certain level. Therefore, a coating film obtained from a powder coating prepared from such a composition is inferior in smoothness and requires a large amount of a photopolymerization initiator to obtain sufficient hardness. There was a problem that the heat resistance of the film was insufficient and the yellowing was likely to occur.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the various problems of the conventional powder coating composition as described above, and is excellent in hardness and smoothness and various properties such as heat-resistant yellowing. It is an object of the present invention to provide an energy ray-curable composition useful as a powder coating for providing a cured coating film having excellent heat resistance.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a compound (A) containing two or more maleimide groups and a compound (A)
A compound (B) containing an ethylenically unsaturated double bond copolymerizable with a maleimide group contained in the compound (B) as an essential component, and the compound (A) and the compound (B)
Softening point of composition obtained by melt-blending
However, a powder coating produced from the composition for an energy ray-curable powder coating at 60 to 130 ° C. gives a cured coating film which is excellent in hardness and smoothness, and which is excellent in various performances such as heat-resistant yellowing. The present inventors have found that the above-mentioned problems can be solved, and have completed the present invention.

That is, the present invention relates to a compound (A) containing at least 1.2 maleimide groups.
And a compound (B) containing an ethylenically unsaturated double bond copolymerizable with a maleimide group contained in the compound (A) as an essential component, and the compound (A)
The composition (S) obtained by melt-blending the compound (B) with the compound (B) has a softening point (ring and ball method) of 60 to 130 ° C.,

[0008] 2. The compound (A) is a compound in which a divalent or higher valent organic group containing a spiro ring structure having an ether oxygen atom in the ring and two or more maleimide groups are bonded by a carbon-nitrogen bond, and The powder coating composition according to the above 1, which is a compound having a melting point of 40 ° C. or higher,

3. The compound (A) is a compound in which a divalent or higher valent organic group containing an ether bond derived from an oxymethylene unit and two or more maleimide groups are bonded by a carbon-nitrogen bond, and has a melting point of 40. The composition for a powder coating according to the above 1, which is a compound having a temperature of at least 0 ° C.

[0010] 4. Compound (A) having a softening point of 6
The composition for a powder coating according to the above 1, which is a polymer at 0 to 130 ° C,

5. The composition for powder coating according to the above 4, wherein the polymer is an acrylic resin,

6. The above-mentioned compound (B), wherein the compound (B) contains at least one double bond selected from the group consisting of an acryloyl group, a methacryloyl group, a vinyl ether group and an unsaturated dicarboxylic acid ester group.
Composition for powder coating according to, and,

7. 1 or 6 above, wherein the compound (B) is at least one selected from the group consisting of an acrylic resin, a saturated polyester resin, an unsaturated polyester resin, and a polyurethane resin, each having a softening point of 60 to 130 ° C. The composition for powder coating according to the above.

In the present invention, the softening point is defined as JI
As defined in SK-2207, it refers to the softening temperature measured in glycerin at a rate of 3 ± 0.5 ° C./min by the so-called ring and ball method.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The present invention basically contains a compound (A) containing two or more maleimide groups, and an ethylenically unsaturated double bond copolymerizable with the maleimide group contained in the compound (A). Compound (B) is contained as an essential component,
In addition, the composition (S) obtained by melt-blending the compound (A) and the compound (B) has a softening point of 60 to 130 ° C, which is a composition for an energy ray-curable powder coating. It is about. As described above, the softening point of the composition (S) is from 60 to 60 from the viewpoint of the balance between the blocking resistance of the obtained powder coating and the appearance of the cured coating film.
It is appropriate to set the temperature within the range of 130 ° C, preferably 80 to 120 ° C.

The compound (A) containing two or more maleimide groups used as one of the essential components of the resin composition for powder coating of the present invention will be described.

Examples of the compound (A) containing a maleimide group include oligomers or polymers having a molecular weight distribution such as a condensation system and an addition polymerization system (hereinafter, these are collectively referred to as compound (AP)), And compounds having a relatively high molecular weight and a mixture containing a relatively high content thereof (hereinafter, these are abbreviated as compound (AL)).

Among such compounds (A), compound (A)
Representative examples of L) include a divalent or higher valent organic group containing at least one bond selected from the group consisting of an ester bond, an ether bond, a carbonate bond and a urethane bond, and two or more maleimides. The group is carbon-
Examples include a compound bonded by a nitrogen bond and a compound in which a divalent or higher valent hydrocarbon group and two or more maleimide groups are bonded by a carbon-nitrogen bond.

Among such compounds (AL), specific examples of the compound in which a divalent or higher valent hydrocarbon group and two or more maleimide groups are bonded by a carbon-nitrogen bond include N,
N′-metaphenylene bismaleimide, N, N′-diphenylmethane bismaleimide, ethylene bismaleimide or N, N′-tetramethylene bismaleimide,
Such as N, N'-dodecamethylene bismaleimide.

Among the above-mentioned compounds (AL), specific examples of the compound in which a divalent or higher valent organic group containing at least one ether bond and two or more maleimide groups are bonded by a carbon-nitrogen bond, Is a compound in which a divalent or higher valent organic group containing a spiro ring structure having an ether oxygen atom in the ring and two or more maleimide groups are bonded by a carbon-nitrogen bond [hereinafter, this is referred to as compound (AL-1). Abbreviated name];
A divalent or more organic group containing at least one ether bond derived from an oxymethylene unit represented by —CH ₂ O—, other than the divalent or more organic group included in the compound (AL-1). An organic group and two or more maleimide groups are carbon-
And a compound bonded by a nitrogen bond [hereinafter, this is abbreviated as compound (AL-2)].

As a typical example of the compound (AL-1), a compound represented by the following formula (I) can be given.

[0022]

Embedded image

(Wherein, m and n each independently represent an integer of 1 to 5, and m + n is 6 or less. X and Y each independently have a substituent. Represents an alkylene group which may or may not have an alkylene group or an alkylenecarbonyloxy group which may or may not have a substituent, wherein p1, p2, q1 and q2 are each independently Te, .R ₁ and R ₂ represents an integer of 0 to 5, each independently may have a substituent or may not have, .R represents an alkylene group or an arylene group _'1 And R ′ ₂ each independently represent a hydrogen atom, an alkyl group or an aryl group or an aralkyl group which may or may not have a substituent.)

A typical alkylene group which may or may not have a substituent represented by X or Y contained in the compound represented by the above general formula (I) is methylene. Linear alkylene groups such as groups, ethylene groups, trimethylene groups, tetramethylene groups, pentamethylene groups, hexamethylene groups; propylene groups, 1-methyl-trimethylene groups, 2-methyl-trimethylene groups, 1-methyl-tetramethylene groups A 2-methyl-tetramethylene group,
Alkylene groups having a branched structure such as 1-methyl-pentamethylene group, 2-methyl-pentamethylene group, 3-methyl-pentamethylene group, 2,2-dimethyltrimethylene group; hydroxymethylene group, 1-hydroxyethylene group A 1-hydroxytetramethylene group, a 2-hydroxytetramethylene group, a 1-hydroxypentamethylene group,
Hydroxyalkylene groups such as 2-hydroxypentamethylene group and 3-hydroxypentamethylene group; carboxymethylene group, 1-carboxyethylene group, 1-carboxytrimethylene group, 2-carboxytrimethylene group,
1-carboxytetramethylene group, 2-carboxytetramethylene group, 1-carboxypentamethylene group, 2-
Carboxyalkylene groups such as carboxypentamethylene group and 3-carboxypentamethylene group; aminomethylene group, aminoethylene group, 1-aminotrimethylene group, 2
And aminoalkylene groups such as -aminotrimethylene group, 1-aminotetramethylene group, 2-hydroxytetramethylene group, 1-aminopentamethylene group, 2-aminopentamethylene group and 3-aminopentamethylene group. However, the present invention is not limited to these.

Representative alkylenecarbonyloxy groups which may or may not have a substituent represented by X or Y include methylenecarbonyloxy, ethylenecarbonyloxy, trimethylenecarbonyloxy Linear alkylene carbonyloxy groups such as a group, tetramethylenecarbonyloxy group, pentamethylenecarbonyloxy group, hexamethylenecarbonyloxy group; propylenecarbonyloxy group, 1-methyl-trimethylenecarbonyloxy group, 2-methyl-trimethylenecarbonyl Oxy group, 1-methyl-tetramethylenecarbonyloxy group, 2-methyl-tetramethylenecarbonyloxy group, 1-methyl-pentamethylenecarbonyloxy group, 2-methyl-pentamethylenecarbonyloxy group, 3-methyl- Printer methylene carbonyl group, alkylene carbonyloxy group having such branched structure 2,2-dimethyl trimethylene carbonyloxy group;

A hydroxymethylenecarbonyloxy group,
2-hydroxydimethylenecarbonyloxy group, 1-hydroxytrimethylenecarbonyloxy group, 2-hydroxytrimethylenecarbonyloxy group, 1-hydroxytetramethylenecarbonyloxy group, 2-hydroxytetramethylenecarbonyloxy group, 1-hydroxypentamethylene Hydroxyalkylenecarbonyloxy groups such as carbonyloxy group, 2-hydroxypentamethylenecarbonyloxy group and 3-hydroxypentamethylenecarbonyloxy group; aminomethylenecarbonyloxy group, aminoethylenecarbonyloxy group, 1-aminotrimethylenecarbonyloxy group, 2-aminotrimethylenecarbonyloxy group, 1-aminotetramethylenecarbonyloxy group, 1-aminopentamethylenecarbonyloxy group, 2-A Roh pentamethylene carbonyloxy group, 3-amino-pentamethylene carbonyl such aminoalkylene carbonyloxy group group, and the like, but not limited thereto.

Particularly preferred as the various X or Y described above are various alkylene groups or alkylenecarbonyloxy groups not containing an amino group as a substituent.

The ring structure sandwiched between R ₁ and R ₂ is generally called a spiro ring structure. Typical organic groups having such a ring structure are 1,3,5,7- Tetraoxaspiro [3,3] -2,6-heptylene group, 1,
3,5,7-tetraoxaspiro [3,4] -2,6-
Octylene group, 1,3,5,7-tetraoxaspiro [3,5] -2,6-nonylene group, 1,3,6,8-tetraoxaspiro [3,5] -2,7-nonylene group ,
1,3,5,7-tetraoxaspiro [3,6] -2,
6-decylene group, 1,3,6,8-tetraoxaspiro [3,6] -2,7-decylene group, 1,3,7,9-tetraoxaspiro [3,7] -2,8- Undecylene group, 1,3,6,8-tetraoxaspiro [4,4]-
2,7-nonylene group, 1,3,6,8-tetraoxaspiro [4,5] -2,7-decylene group, 1,3,7,9
-Tetraoxaspiro [4,5] -2,8-decylene group, 1,3,7,9-tetraoxaspiro [4,6]-
2,8-undecylene group, 1,3,8,10-tetraoxaspiro [4,7] -2,9-dodecylene group, 2,
4,7,9-tetraoxaspiro [5,5] -3,8-
Undecylene group, 2,4,8,10-tetraoxaspiro [5,5] -3,9-undecylene group, 2,4,8,
10-tetraoxaspiro [5,6] -3,9-dodecylene group, 2,4,9,11-tetraoxaspiro [5,
7] -3,10-tridecylene group and the like. And among these, a 2,4,8,10-tetraoxaspiro [5,5] -3,9-undecylene group is mentioned as one of the particularly preferable ones.

Even if the compound represented by the above formula (I) has a substituent as R ₁ and R ₂ ,
Examples of the alkylene group or arylene group which may not be present include, for example, a linear alkylene group such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, and a hexamethylene group;
-Methyl-trimethylene group, 2-methyl-trimethylene group, 1-methyl-tetramethylene group, 2-methyl-tetramethylene group, 1-methyl-pentamethylene group, 2-methyl-pentamethylene group, 3-methyl-pentane Alkylene groups having a branched structure such as methylene group and 2,2-dimethyltrimethylene group; hydroxymethylene group, 1-hydroxyethylene group, 1-hydroxytrimethylene group,
Hydroxyalkylene groups such as -hydroxytrimethylene group, 1-hydroxytetramethylene group, 2-hydroxytetramethylene group, 1-hydroxypentamethylene group, 2-hydroxypentamethylene group, and 3-hydroxypentamethylene group;

Carboxymethylene group, carboxyethylene group, 1-carboxytrimethylene group, 2-carboxytrimethylene group, 1-carboxytetramethylene group, 2
Carboxyalkylene groups such as -carboxytetramethylene group, 1-carboxypentamethylene group, 2-carboxypentamethylene group and 3-carboxypentamethylene group; aminomethylene group, aminoethylene group, 1-aminotrimethylene group, 2-amino Aminoalkylene groups such as trimethylene group, 1-aminotetramethylene group, 2-hydroxytetramethylene group, 1-aminopentamethylene group, 2-aminopentamethylene group, 3-aminopentamethylene group; phenylene group, 1-methyl Phenylene group, 2
-Methylphenylene group, 1-hydroxyphenylene group,
An arylene group such as a 2-hydroxyphenylene group; an alkylene group substituted with an aryl group such as a benzylidene group, an orthomethylbenzylidene group, a metamethylbenzylidene group, an orthohydroxybenzylidene group, and a metahydroxybenzylidene group. It is not limited. Of the various R ₁ and R ₂ listed here,
Particularly preferred are alkylene and arylene groups that do not contain amino groups.

Examples of the alkyl group, aryl group or aralkyl group which may or may not have a substituent as R ′ ₁ and R ′ ₂ include, for example, methyl group, ethyl group, n Linear alkyl groups such as -propyl group, n-butyl group, n-pentyl group, n-hexyl group; isopropyl group, sec-butyl group, isobutyl group, 1-methyl-
Alkyl groups having a branched structure such as butyl group, 2-methyl-butyl group, 1-methyl-pentyl group, 2-methyl-pentyl group, 3-methyl-pentyl group, neopentyl group; hydroxymethyl group, 2-hydroxyethyl Group, 1
-Hydroxypropyl group, 2-hydroxypropyl group,
1-hydroxybutyl group, 2-hydroxybutyl group, 1
-Hydroxypentyl group, 2-hydroxypentyl group,
Hydroxyalkyl groups such as 3-hydroxypentyl group; carboxylmethyl group, 2-carboxyethyl group,
Carboxyalkyl groups such as 1-carboxypropyl group, 2-carboxypropyl group, 1-carboxypropyl group, 2-carboxybutyl group, 1-carboxypentyl group, 2-carboxypentyl group and 3-carboxypentyl group; aminomethyl group Aminoalkyl groups such as, 2-aminoethyl group, 1-aminopropyl group, 2-aminopropyl group, 1-aminobutyl group, 1-aminopentyl group, 2-aminopentyl group and 3-aminopentyl group; phenyl group And aryl groups such as 2-methylphenyl group, 3-methylphenyl group, 2-hydroxyphenyl group and 3-hydroxyphenyl group; and aralkyl groups such as benzyl group, 1-methylbenzyl group and 3-methylbenzyl group. However, the present invention is not limited to this. Among the various R ′ ₁ and R ′ ₂ and the hydrogen atom exemplified herein, particularly preferred are various monovalent organic groups containing no hydrogen atom or amino group.

Contained in the above-mentioned compound (AL-2)
-CH_TwoEther bond derived from O-oxymethylene unit
Representative of a divalent or higher valent organic group containing at least one of
For example,-(CH_Two)_Three-O- (CH_Two)_Three-,-(CH_Two)_Three-O- (CH_Two)
_Two-O- (CH_Two)_Three-,-(CH_Two)_Three-O- (CH _Two)_Four-O- (CH_Two)_Three-,-(CH_Two)_Three-O
-CH_Two-C (CH_Three)_Two-CH_Two-O- (CH_Two)_Three-,-(CH_Two)_Three-O- (CH_Two)_Two-O- (CH
_Two)_Two-O- (CH_Two)_Three-1 to 3 oxymethylene units such as
Containing divalent organic group; C_TwoH_FiveC (CH_TwoOCH_TwoCH_Two-)_Three, C (CH_TwoOC
H_TwoCH_Two-)_FourTrivalent containing oxymethylene units such as
Is a tetravalent organic group;-(CH_Two) rCOO- (CH_Two)_Two-O- (CH_Two)_Two-OOC- (CH
_Two) r- (where r is an integer of 1 to 12),-
(CH_Two) rCOO- (CH_Two)_Two-O- (CH_Two)_Two-O- (CH_Two)_Two-OOC- (CH_Two) r- (however
And r is the same as above),-(CH_Two) rCOO-CH_TwoCH (CH_Three) -O-CH_TwoC
H (CH_Three) -OOC- (CH_Two) r- (where r is the same as above)
A divalent organic group having a stele bond; C_TwoH_FiveC [CH_TwoOCH_TwoCH
_TwoOOC (CH_Two) r-]_Three, C [CH_TwoOCH_TwoCH_TwoOOC (CH_Two) r-]_Four(However,
r is the same as above) and esterified with oxymethine unit
A trivalent or tetravalent organic group having a combination of-; (CH_Two) rCOO-CH_Two
CH (OH) CH_Two-O- (CH_Two)_Two-O-CH_TwoCH (OH) CH_Two-OOC- (CH_Two) r- (however
And r is the same as above),-(CH_Two) rCOO-CH_TwoCH (OH) CH_Two-O- (C
H_Two)_Two-O- (CH_Two)_Two-O-CH _TwoCH (OH) CH_Two-OOC- (CH_Two) r- (however, r
Is the same as above),-(CH_Two) rCOO-CH_TwoCH (OH) CH_Two-O- (CH_Two)_Four-O
-CH_TwoCH (OH) CH_Two-OOC- (CH_Two) r- (where r is the same as above
),-(CH_Two) rCOO-CH_TwoCH (OH) CH_Two-O- (CH_Two)₆-O-CH_TwoCH (OH)
CH_Two-OOC- (CH_Two) r- (where r is the same as above),-(CH_Two) rCO
O-CH_TwoCH (OH) CH_Two-O-CH_TwoC (CH_Three)_TwoCH_Two-O-CH_TwoCH (OH) CH_Two-OOC-
(CH_Two) r- (where r is the same as above),-(CH_Two) rCOO-CH_TwoCH
(OH) CH_Two-O-ph-C (CH_Three)_Two-Ph-O-CH_TwoCH (OH) CH_Two-OOC- (CH_Two) r-
(However, r is the same as above, and -Ph- is paraphenylene
Represents a group),-(CH_Two) rCOO-CH_TwoCH (OH) CH_Two-O-ph-C (CH_Three)_Two-P
h-O-CH_TwoCH (OH) CH_Two-OOC- (CH_Two) r- (However, r and -Ph-
The same as the above).
A divalent organic group; furthermore,-(CH_Two)_Two-OCO (OCH_TwoCH_Two)_Two-OCOO
-(CH_Two)_Two-Or- (CH_Two) _Two-OCO (OCH_TwoCH_Two)_Three-OCOO- (CH_Two)_Two-
Divalent organic groups also containing carbonate groups such as
I can do it.

Accordingly, typical examples of the compound (AL-2) include various compounds having a structure in which a nitrogen atom of a maleimide group is bonded to a terminal carbon atom of various divalent organic groups as described above. No.

Specific examples of the compound (AL) in which two or more maleimide groups are bonded to a divalent or higher valent organic group containing a urethane bond by a carbon-nitrogen bond include various low molecular weight compounds. And various compounds obtained by reacting a hydroxyl group-containing maleimide compound such as an N-hydroxyalkylmaleimide compound. Typical examples of the polyisocyanate compound used in preparing the maleimide compound include tolylene diisocyanate, 4,
Aromatic diisocyanates such as 4'-diphenylmethane diisocyanate; aralkylene diisocyanates such as meta-xylylene diisocyanate; aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate and lysine diisocyanate; isophorone diisocyanate, bis (4- Alicyclic diisocyanates such as isocyanatocyclohexyl) methane and 1,3-bisisocyanatomethylcyclohexane;

Typical examples of the above-mentioned N-hydroxyalkylmaleimide compounds include compounds such as N-hydroxymethylmaleimide, N-2-hydroxyethylmaleimide, and N-4-hydroxybutylmaleimide. By reacting such an N-hydroxyalkylmaleimide compound by a known and commonly used method, a compound containing a desired maleimide group (A
L) can be synthesized.

Specific examples of the compound (AL) in which two or more maleimide groups are bonded to a divalent or higher valent organic group containing an ester bond by a carbon-nitrogen bond include the compounds described above ( AL-2), in addition to the compound having both an ester bond and an oxymethylene unit, a maleimide compound containing various carboxyl groups or a carboxyl obtained from the maleimide compound containing the carboxyl group and a monohydric alcohol. A compound obtained by reacting a maleimide compound containing an acid ester group with a polyhydric alcohol not containing an ether bond; a reaction product of a polyepoxy compound containing no ether bond with a maleimide compound containing a carboxyl group; No.

Representative examples of the maleimide compound containing a carboxyl group used in preparing such a maleimide compound (AL) containing an ester bond include N-carboxymethylmaleimide and N- (2-carboxy). Various N-carboxyalkyls such as ethylmaleimide, N- (3-carboxy) propylmaleimide, N- (5-carboxy) pentylmaleimide, N- (10-carboxy) decylmaleimide, N- (12-carboxy) undecylmaleimide And maleimide compounds. Representative examples of the maleimide compound having a carboxylic acid ester group include various N-type compounds described above.
-Various esters obtained by reacting a carboxyalkylmaleimide compound with various lower monohydric alcohols such as methanol, ethanol or n-butanol.

Representative examples of polyhydric alcohols used for obtaining a maleimide compound (AL) containing an ester bond include ethylene glycol, 1,2
Glycols such as propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,6-hexanediol, neopentyl glycol;
And trihydric or higher polyhydric alcohols such as trimethylolpropane, trimethylolethane, glycerin, pentaerythritol and sorbitol. In order to prepare the compound (AL) from such a polyhydric alcohol and a maleimide compound containing a carboxyl group or a carboxylic ester group as described above, a known and conventional method using a known and commonly used dehydration condensation catalyst or a transesterification catalyst is used. Should be applied.

Representative examples of the polyepoxy compound used for preparing the compound (AL) by reacting a polyepoxy compound having no ether bond with a maleimide compound having a carboxyl group include adipic acid and sebacine. Polyglycidyl esters of various polycarboxylic acids such as acid, terephthalic acid, trimellitic acid;
3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, bis- (3,4
Alicyclic polyepoxy compounds such as -epoxycyclohexyl) adipate; and polyepoxy compounds containing a heterocyclic ring such as triglycidyl isocyanurate. In order to prepare the compound (A) by the reaction between the polyepoxy compound and the maleimide compound having a carboxyl group as described above, a known and commonly used method used when performing an esterification reaction between the carboxyl group and the epoxy group is used. Apply the method.

Among the compounds (AL), a compound in which two or more maleimide groups are bonded to a divalent or higher valent organic group containing a carbonate bond by a carbon-nitrogen bond is more specifically a bis (maleimide Compounds such as methyl) carbonate and bis (2-maleimidoethyl) carbonate are exemplified.

The various compounds (AL) described above include:
Each of them may be used alone, or two or more compounds may be used in combination. Further, even when these are liquid, the softening point of the composition (S) obtained by melt-blending with the compound (B) is within the above-mentioned range, and within the range not impairing the blocking resistance and the like. Any quantity can be used. Among the compounds (AL), particularly preferable in terms of curability and hardness of the obtained coating film,
A divalent or higher valent organic group containing a spiro ring structure having an ether oxygen atom in the ring and two or more maleimide groups are carbon-
Bonded by a nitrogen bond and having a melting point of 4
0 ° C. or higher, and a compound in which a divalent or higher valent organic group containing an ether bond derived from an oxymethylene unit and two or more maleimide groups are bonded by a carbon-nitrogen bond, and which has a melting point of 40 ° C. A compound having a temperature of not less than ° C.

Further, among the compounds (A) containing a maleimide group, at least one, preferably at least two, compounds (AP), which are oligomers or polymers of condensation type or addition polymerization type, etc. Various polymers containing a maleimide group can be used.
Typical examples of the compound (AP) include various polymers such as polyether resins, modified epoxy resin polymers, polyester resins, polyurethane resins, and vinyl polymers.

Among these polymers, typical vinyl polymers include various polymers such as acrylic polymers, polyolefin polymers, and fluoroolefin polymers. Examples of the polyester-based resin include a saturated polyester resin, an alkyd resin, and an unsaturated polyester resin.

Representative examples of the polyether resin containing a maleimide group as described above include various commonly used hydroxyl group-containing polyethers such as polyethylene glycol, polyethylene triol, polypropylene glycol, polypropylene triol and polytetramethylene glycol. Two or more maleimidoalkyl groups obtained by reacting an ether polyol with a maleimide compound containing a carboxyl group as described above or an ester thereof with a lower alcohol by a dehydration condensation reaction or a transesterification reaction are used. A polyether resin introduced through an ester bond; and a polyether resin containing two or more maleimide groups prepared by the following method.

The above-mentioned polyether polyols and the above-mentioned diisocyanate compound are reacted in a ratio such that the isocyanate groups are excessive with respect to the hydroxyl groups to prepare a prepolymer having an isocyanate group at the terminal, Next, a maleimide compound having a hydroxyl group such as the above-mentioned N-hydroxyalkylmaleimide is reacted with the obtained prepolymer to introduce two or more maleimidealkyl groups via a urethane bond. Diglycidyl ethers of known and commonly used polyether polyols such as polyethylene glycol diglycidyl ale, polypropylene glycol diglycidyl ale, polytetramethylene glycol diglycidyl ale,
A maleimide compound having a carboxyl group such as N-carboxyalkylmaleimide as described above is reacted to introduce two or more maleimidoalkyl groups via an ester bond.

A typical modified epoxy resin-based polymer as the compound (AP) has a number average molecular weight of 50.
Those obtained by reacting a maleimide compound having a carboxyl group such as the above-mentioned N-carboxyalkylmaleimide with various epoxy resins of about 0 to 3,000 are exemplified.

Representative examples of the epoxy resin used at that time include bisphenols obtained by reacting various bisphenol compounds such as bisphenol A, bisphenol S and bisphenol F with epichlorohydrin or methyl epichlorohydrin. ) Glycidyl ether type epoxy resin; hydrogenated bisphenols such as hydrogenated bisphenol A, hydrogenated bisphenol S and hydrogenated bisphenol F, and (methyl) glycidyl of hydrogenated bisphenols obtained by reaction with epichlorohydrin or methylepichlorohydrin Ether type epoxy resin; for the reaction of novolak resin such as phenol novolak resin or cresol novolak resin with epichlorohydrin or methyl epichlorohydrin Ri (methyl) glycidyl ether type epoxy resin of the obtained novolak resins.

Representative examples of the saturated polyester resin containing a maleimide group include, for example, a polyester polyol obtained by condensing a known and commonly used saturated polycarboxylic acid and a known and commonly used polyhydric alcohol as a raw material. Alternatively, polycaprolactone polyols obtained by reacting the above-mentioned polyhydric alcohols with ε-caprolactone, and the above-mentioned various diisocyanates are reacted at a ratio such that the isocyanate groups are excessive relative to the hydroxyl groups. After preparing a prepolymer having an isocyanate group at the terminal, the prepolymer is reacted with a maleimide compound having a hydroxyl group such as the above-mentioned N-hydroxyalkylmaleimides to obtain two or more maleimidealkyl groups. Satiety joined through a bond And polyester resin.

Representative examples of the saturated dibasic acid used in preparing the above-mentioned saturated polyester resin include:
Saturated dibasic acids such as phthalic acid, terephthalic acid, isophthalic acid, succinic acid, adipic acid, sebacic acid, and hexahydrophthalic acid; and trivalent or higher polycarboxylic acids such as trimellitic acid and butanetetracarboxylic acid Which can be used as a reactive derivative such as an ester with a lower alcohol or an acid anhydride.

Representative examples of the polyhydric alcohol used in preparing the above-mentioned saturated polyester resin include various polyhydric alcohols exemplified as those used in preparing the above-mentioned maleimide compound (AL). Polyhydric alcohols.

Representative examples of unsaturated polyester resins containing a maleimide group include unsaturated dibasic acids obtained by condensing a known and commonly used unsaturated dibasic acid with a raw material containing a polyhydric alcohol as an essential component as described above. A polyester polyol containing a basic acid ester group and the above-described various diisocyanates were reacted at a ratio such that the isocyanate group became excessive with respect to the hydroxyl group to prepare a prepolymer containing an isocyanate group at the terminal. A resin obtained by reacting with a maleimide compound containing a hydroxyl group such as the above-mentioned N-hydroxyalkylmaleimides and having two or more maleimidoalkyl groups bonded via a urethane bond may be used.

Representative examples of the unsaturated dibasic acid used in preparing such an unsaturated polyester resin include compounds such as maleic acid, fumaric acid, itaconic acid and tetrahydrophthalic acid, and lower compounds of these compounds. Reactive derivatives such as esters with monohydric alcohols or acid anhydrides are exemplified.

Representative examples of the polyurethane resin as the compound (AP) include, for example, the above-mentioned diisocyanate and polyhydric alcohols as essential raw materials, and an excess of isocyanate groups relative to hydroxyl groups. These are reacted at a ratio to prepare a polyurethane prepolymer containing an isocyanate group, and the obtained prepolymer is reacted with a maleimide compound containing a hydroxyl group such as the above-mentioned N-hydroxyalkylmaleimides. Examples of the obtained polyurethane resin include two or more maleimidealkyl groups bonded via a urethane bond.

In preparing such a polyurethane resin containing a maleimide group, the polyhydric alcohol component used includes, in addition to the various low molecular weight polyhydric alcohols as described above, various polyhydric alcohols as described above. Polyether polyols and polyester polyols can be used.

Typical examples of the vinyl polymer as the compound (AP) include various polymers prepared by the following methods. A carboxyl group-containing maleimide compound typified by N-carboxyalkylmaleimide described above is reacted with a previously prepared epoxy group-containing vinyl polymer to form two or more maleimide alkyl groups via an ester bond. Introduce a group. A vinylimide polymer containing an isocyanate group prepared in advance is reacted with a maleimide compound containing a hydroxyl group typified by the N-hydroxyalkylmaleimide described above to form two or more maleimidealkyl groups via a urethane bond. Introduce.

The vinyl polymer containing an epoxy group used in the above-mentioned method includes glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, and 3,4-epoxycyclohexylmethyl (meth).
Acrylate, allyl glycidyl ether, vinyl monomers containing an epoxy group represented by glycidyl vinyl ether alone or by copolymerizing these monomers with other copolymerizable monomers Prepared.

Typical examples of other copolymerizable monomers used in this case include methyl (meth) acrylate, ethyl (meth) acrylate, and n-butyl (meth) acrylate.
Acrylate, iso-butyl (meth) acrylate,
C _{1-such as} tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and stearyl (meth) acrylate
Various alkyl (meth) having C ₁₈ alkyl group
Acrylates;

Various alicyclic alkyl (meth) such as cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate and isobornyl (meth) acrylate
Acrylates; benzyl (meth) acrylate, 2-
Various aralkyl (meth) acrylates, such as phenethyl (meth) acrylate;

Various alkyl esters of crotonic acid, such as methyl crotonate and ethyl crotonate; dimethyl maleate, di-n-butyl maleate, dimethyl fumarate, di-n-butyl fumarate, dimethyl itaconate, Dialkyl esters of various unsaturated dicarboxylic acids such as n-butyl itaconate; containing hydroxyl groups such as 2-hydroxyethyl (mear) acrylate, 2-hydroxypropyl (mear) acrylate and 4-hydroxybutyl (mear) acrylate (Meth) acrylates; 2-hydroxyethyl vinyl ether, 4-
Hydroxy group-containing vinyl ethers such as hydroxybutyl vinyl ether; hydroxyl-containing allyl ethers such as 2-hydroxyethyl allyl ether and 4-hydroxybutyl allyl ether:

Various aromatic vinyl monomers such as styrene, p-tert-butylstyrene, α-methylstyrene and vinyltoluene; (meth) acrylamide;
Various amide group-containing monomers such as N, N-dimethyl (meth) acrylamide and N, N-diethyl (meth) acrylamide; various cyano group-containing monomers such as (meth) acrylonitrile and crotononitrile Various haloolefins such as vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinyl chloride and vinylidene chloride; various α-olefins such as ethylene, propylene and isobutylene s; vinyl acetate, vinyl propionate, vinyl pivalate, such as versatic acid vinyl having C ₈ -C ₁₀ becomes branched alkyl group, various carboxylic acid vinyl esters; ethyl vinyl ether, n- butyl vinyl ether, isobutyl vinyl ether , Cyclohexyl Vinyl ether such as, various alkyl vinyl ethers or cycloalkyl vinyl ethers and the like.

Representative examples of the vinyl monomer containing an isocyanate group used in the above method include 2-isocyanatoethyl (meth) acrylate, 3-isopropenyl-α, α-dimethylbenzyl. Examples include isocyanates.

Typical examples of other vinyl monomers used for copolymerization with the vinyl monomer containing an isocyanate group include the above-mentioned monomers containing an epoxy group. Among the various monomers exemplified above as monomers copolymerizable with the monomer containing an epoxy group, those other than the monomers containing an active hydrogen such as a hydroxyl group are exemplified.

In order to prepare a vinyl-based polymer containing an epoxy group or an isocyanate group by the above-mentioned method or the above-mentioned method, various known and common methods can be applied. It is simple.

The weight-average molecular weight of the various compounds (AP) is generally about 500 to 10 in view of the curability of the powder coating obtained from the composition of the present invention and the appearance of the cured coating film.
It may be set to about 0000, preferably about 1,000 to 50,000. In addition, the amount of the maleimide group introduced into such various polymers needs to be set optimally according to the type of the polymer or the molecular weight of the polymer, but the curability and the flexibility of the cured coating film, etc. From the point of view of the polymer of 1,000
The amount may be about 0.3 to 7.0 mol, preferably about 0.5 to 5.0 mol per gram.

The various compounds (AP) described above are
Even if the composition is liquid, it can be used as long as the softening point of the composition (S) is within the above-mentioned range and the amount does not impair the blocking resistance and the like, but it is solid at least at 30 ° C. Are preferred. The softening point of such a polymer is suitably set within the range of 50 to 140 ° C, preferably 60 to 130 ° C.

Among the above-mentioned various polymers, preferred are modified epoxy resin-based polymers and vinyl-based polymers. Among the vinyl-based polymers, (meth) acrylic acid is particularly preferred. An acrylic resin prepared by using an ester as an essential monomer component is exemplified.

Next, the compound (A) containing a maleimide group-containing compound (A) and a compound (B) containing an ethylenically unsaturated double bond, which has copolymerizability, will be described in detail.

Examples of the ethylenically unsaturated double bond introduced into the compound (B) include an olefinic double bond, a crotonoyl group, an acryloyl group, a methacryloyl group,
Various double bonds other than a maleimide group such as a vinyl ether group, an unsaturated dibasic acid ester group, and a vinyl ester group are exemplified.

The compound (B) includes, in addition to oligomers or polymers having a molecular weight distribution such as a condensation system or an addition polymerization system (hereinafter, these are collectively referred to as compound (BP)), There are a compound, a compound having a relatively high molecular weight and a single molecular weight, and a mixture containing these at a relatively high content (hereinafter, these are abbreviated as compound (BL)). Such a compound (B) may be used alone or as a blend of two or more.

Among the compounds (B), the compound (BL) includes a compound containing one or more such double bonds in the molecule. In the compound (BL) containing two or more double bonds, those double bonds may be the same or two or more different types.

Typical examples of the compound (BL) containing one double bond as the compound (BL) include various functional groups as described above or exemplified as those used in the method. Liquid or solid monomers at room temperature among vinyl monomers or vinyl monomers containing no functional group; or various functional groups such as epoxy group, hydroxyl group and isocyanate group used in the method A vinyl-containing monomer containing a group and a compound containing a functional group such as a carboxyl group, an isocyanate group or a hydroxyl group, which does not contain a double bond, which reacts with the various functional groups. Compounds obtained; (meth) acryloyloxymethylmaleimide, 2-[(meth) acryloyloxy] ethylmaleimide, 5-[( Data) acryloyloxy]
Compounds having both one maleimide group and one double bond other than the maleimide group, such as pentylmaleimide, may be mentioned.

Typical examples of the compound having two or more carbon-carbon double bonds in the molecule as the compound (BL) include the above-mentioned various low molecular weight polyhydric alcohols and ) Ethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate or trimethylolpropane tri (meth) obtained by reacting acrylic acid or crotonic acid
Poly (meth) acrylates represented by acrylates; polycrotonates represented by ethylene glycol dicrotonate, 1,6-hexanediol crotonate or trimethylolpropane tricrotonate; divinyl succinate, adipic acid Polyvinyl esters of polycarboxylic acids such as divinyl ester, divinyl sebacate and divinyl phthalate; ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetramethylene glycol divinyl ether, 1,6-hexanediol divinyl ester Various polyvinyl ethers such as vinyl ether, cyclohexane-1,4-dimethanol divinyl ether, and trimethylolpropane trivinyl ether Ether compounds;

The above-mentioned various low-molecular-weight polyisocyanate compounds are used as hydroxyl-containing (meth) acrylates represented by 2-hydroxyethyl (meth) acrylate or 2-hydroxypropyl (meth) acrylate, It contains hydroxyl groups such as vinyl ethers containing hydroxyl groups typified by ethyl vinyl ether and 4-hydroxybutyl vinyl ether or unsaturated dibasic acid esters containing hydroxyl groups typified by monomethyl-mono-2-hydroxyethyl fumarate A compound in which two or more double bonds are bonded through a urethane bond obtained by reacting with a vinyl monomer to be reacted; further, a polyglycidyl ether of various polyhydric alcohols or the compound (AL) described above. Illustrated as one that can be used when preparing Various polyepoxy compounds such as polyglycidyl ester of carboxylic acid and various carboxyl groups such as (meth) acrylic acid, crotonic acid, monomethyl maleate, monomethyl itaconate, monomethyl fumarate, monovinyl succinate and monovinyl adipate Examples include various monomers containing a hydroxyester group obtained by reacting the vinyl monomer contained therein.

The compound (BP), which is a polymer in the compound (B), has at least one compound in one molecule.
Preferably, various polymers containing at least two double bonds as described above can be used. And
As the double bond to be introduced, only the same kind may be introduced, or two or more different kinds may be introduced. Representative examples of such polymers include polyether resins, modified epoxy resin-based polymers, polyester-based resins, polyurethane-based resins, and vinyl-based polymers.

Among such polymers, typical examples of the vinyl polymer include various polymers such as an acrylic polymer, a polyolefin polymer and a fluoroolefin polymer. Specific examples of the polyester resin include a saturated polyester resin, an unsaturated polyester resin, and an alkyd resin.

Typical examples of the polyether resins containing various double bonds as described above include polyether polyols represented by polyethylene glycol, polyethylene triol, polypropylene glycol, polypropylene triol, polytetramethylene glycol and the like. Poly (meth) acrylates or polycrotonates prepared by reacting (meth) acrylic acid or crotonic acid; polyvinyl ethers of the aforementioned polyether polyols; and various types prepared by the following methods: Of polyether resins.

The prepolymer having a terminal isocyanate group prepared as an intermediate in the above-mentioned method is reacted with various hydroxyl group-containing vinyl monomers as described above to form a urethane bond. Introduce two or more double bonds through. The above-mentioned various polyether polyols are reacted with the above-mentioned various carboxyl group-containing vinyl monomers.

Representative examples of the modified epoxy resin-based polymer as the compound (BP) are exemplified as those used in preparing the above-mentioned modified epoxy resin-based polymer containing a maleimide group. Various modified resins in which a group containing a double bond is bonded via an ester bond obtained by reacting a vinyl monomer containing various carboxyl groups with various epoxy resins as described above. No.

Specific examples of the saturated polyester resin as the compound (BP) include, for example, an isocyanate group at the terminal of the saturated polyester resin as used in preparing the above-mentioned maleimide group-containing saturated polyester resin. A resin in which a group containing two or more double bonds has been introduced via a urethane bond obtained by reacting the introduced prepolymer with the above-mentioned various vinyl group-containing vinyl monomers; 2 A group containing two or more double bonds is introduced via an ester bond obtained by reacting a saturated polyester resin containing at least one carboxyl group with a vinyl monomer containing an epoxy group as described above. Quenched resins.

Specific examples of the unsaturated polyester resin containing a double bond as the compound (BP) include, for example, the unsaturated polyester resin containing a maleimide group as described above. Containing two or more double bonds via urethane bonds obtained by reacting a prepolymer having an isocyanate group introduced into the terminal of a saturated polyester resin with various types of hydroxyl-containing vinyl monomers as described above. A resin into which a functional group is introduced;
A group containing two or more double bonds via an ester bond obtained by reacting an unsaturated polyester resin containing two or more carboxyl groups with a vinyl monomer containing an epoxy group as described above. The resin introduced is mentioned.

As the unsaturated polyester resin as the compound (BP), known and commonly used unsaturated dibasic acids such as maleic acid, fumaric acid and itaconic acid, or a reactive derivative thereof can be used as an essential dibasic acid component. And a resin prepared by a known and commonly used method can also be used.

Specific examples of the polyurethane resin containing a double bond as the compound (BP) include, for example,
The polyurethane prepolymer having a terminal isocyanate group as used in preparing the above-mentioned maleimide group-containing polyurethane resin is reacted with various hydroxyl group-containing vinyl monomers as described above to form urethane. Resins into which a group containing two or more double bonds is introduced via a bond.

Specific examples of the vinyl polymer as the compound (BP) include, for example, various polymers prepared by the following methods. A vinyl polymer containing an epoxy group as used in the above-mentioned method is reacted with various kinds of unsaturated monocarboxylic acids containing a double bond as exemplified in the above-mentioned method. . The isocyanate group-containing vinyl polymer used in the method described above is reacted with various hydroxyl group-containing vinyl monomers as described above to form two or more vinyl monomers via a urethane bond. A group containing a double bond is introduced.

Each of the various compounds (B) described above may be used alone, or two or more compounds may be used in combination. Also, even if these are liquid,
Composition (S) obtained by melt-blending with compound (A)
Can be used as long as it has a softening point within the above-mentioned range and does not impair the blocking resistance and the like. As the double bond contained in such various compounds (B), among the various double bonds described above, an acryloyl group, a methacryloyl group, a vinyl ether group and an unsaturated dicarboxylic acid are preferable from the viewpoint of copolymerizability with a maleimide group. Particularly preferred is at least one selected from the group consisting of acid ester groups.

Among the above-mentioned compounds (B), the particularly preferable compound (BL) preferably has a melting point of 40 ° C. or more from the viewpoint of blocking resistance. Taking into account, more preferably 40
~ 130 ° C. In the compound (B), the weight average molecular weight of the polymer compound (BP) is as follows:
From the viewpoint of the curability of the powder coating obtained from the composition of the present invention, the appearance of the cured coating film, etc., it may be set to about 500 to 100,000, preferably about 1,000 to 50,000. In addition, the amount of the unsaturated double bond to be copolymerized with the maleimide group introduced into the various polymers needs to be optimally set according to the type of the polymer or the molecular weight of the polymer. From the viewpoints of properties and flexibility of the cured coating film, the amount may be about 0.3 to 7.0 mol, preferably about 0.5 to 5.0 mol, per 1,000 g of the polymer. Also,
The compound (BP) is preferably solid at 30 ° C. from the viewpoint of blocking resistance, and has a softening point of 50 ° C.
It is appropriate to set the temperature in the range of 140 to 140 ° C, preferably 60 to 130 ° C. And among the various polymers described above, particularly preferred are vinyl polymers,
Examples include saturated polyester resins, unsaturated polyester resins, and polyurethane resins. Particularly preferred among the vinyl polymers are acrylic resins prepared using (meth) acrylic esters as an essential monomer component.

The powder coating composition used in the present invention can be obtained from the compound (A) and the compound (B) described above. The powder coating has good blocking resistance, curability, smoothness of the coating film and mechanical properties. (AP) which is an oligomer or a polymer as compound (A) from the viewpoint of the balance of the mechanical strength, etc.
When is used, compound (BL) is used as compound (B)
When a solid compound of the compound (AL) is used as the compound (A), a combination using an oligomer or a polymer (BP) as the compound (B) is used, Particularly preferred. The compounding ratio of the compound (A) and the compound (B) is determined based on the balance between the blocking resistance and the curability of the powder coating and the mechanical strength of the coating film. Compound (A) in total weight
5 to 95%, preferably 10 to 90% by weight
%, Most preferably in the range of 20 to 80%.

Thus, the composition for powder coating of the present invention is prepared, and a compound containing one maleimide group is added to such a composition as long as the characteristics of the present invention are not impaired. Can also. Representative examples of such a compound containing one maleimide group include N-alkylmaleimides such as N-methylmaleimide, N-ethylmaleimide and N-butylmaleimide; N-phenylmaleimide, Np-tolyl N-arylmaleimides such as maleimide; N-hydroxymethylmaleimide, N-2
N-hydroxyalkylmaleimides such as -hydroxyethylmaleimide; N-carboxymethylmaleimide, N- (2-carboxy) ethylmaleimide, N-
Carboxyalkylmaleimides such as (5-carboxy) pentylmaleimide; N-methoxycarbonylmethylmaleimide, N- (n-butoxycarbonyl) methylmaleimide, N- (2-methoxycarbonyl) ethylmaleimide, N- (5-methoxycarbonyl) A) a maleimide compound containing a carboxylic acid ester group obtained by reacting a maleimide compound containing a carboxyl group such as pentylmaleimide with a monohydric alcohol;

N-acetoxymethylmaleimide, N-
Maleimide compound containing an ester bond obtained by reacting an N-hydroxyalkylmaleimide such as (5-benzoyloxy) pentylmaleimide or N- (2-acetoxy) ethylmaleimide with a monocarboxylic acid or a derivative thereof; N-methyl It contains a urethane bond obtained by reacting an N-hydroxyalkylmaleimide with a monoisocyanate compound, such as carbamoyloxymethylmaleimide, Nn-butylcarbamoyloxymethylmaleimide, and N- (2-methylcarbamoyloxy) ethylmaleimide. Various compounds such as a maleimide compound are exemplified.

Since the powder coating composition of the present invention prepared as described above uses the compound (A) containing a maleimide group as an essential component, it can be polymerized without adding a photopolymerization initiator. I can do it. In addition, even when a photopolymerization initiator needs to be added, excellent curability can be exhibited by adding a small amount. In particular, a divalent or higher valent organic group containing a spiro ring structure having an ether oxygen atom in the ring described above as a preferable compound (A) component,
And a compound having a melting point of 40 ° C. or higher, or a divalent or higher organic group containing an ether bond derived from an oxymethylene unit, and two or more maleimide groups bonded by a carbon-nitrogen bond. A maleimide group bonded by a carbon-nitrogen bond, and a melting point of 40 ° C.
When the above compounds are used, a cured film exhibiting excellent curability even without adding a photopolymerization initiator and having particularly excellent heat-resistant yellowing can be obtained.

When a photopolymerization initiator is added to the composition of the present invention, various known and commonly used photopolymerization initiators can be added. Representative examples of such a photopolymerization initiator include, for example, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one,
Acetophenone-based compounds such as benzyldimethylketal, 1-hydroxycyclohexyl-phenylketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one; benzoin-based compounds such as benzoin and benzoin-isopropylether; 4,
Acylphosphine oxide compounds such as 6-trimethylbenzoindiphenylphosphine oxide; benzophenone compounds such as benzophenone and methyl 4-phenylbenzophenone benzophenone; thioxanthone compounds such as 2-isopropylthioxanthone and 2,4-dimethylthioxanthone An aminobenzophenone compound such as Michler's ketone, 4,4'-diethylaminobenzophenone; benzyl, methylphenylglyoxyester, 10-butyl-2-chloroacridone, 2-ethylanthraquinone, 9,10-phenanthrene Various compounds such as quinone and camphorquinone are exemplified. When such a photopolymerization initiator is added, the amount added is preferably 0.1 to 100 parts by weight of the composition of the present invention.
The amount may be about 0.01 to 10.0 parts by weight, preferably about 0.1 to 5.0 parts by weight, and most preferably about 0.2 to 3.0 parts by weight.

In curing the composition of the present invention by irradiating it with active energy rays such as ultraviolet rays, a photosensitizer may be used in combination in order to carry out the curing reaction more efficiently. Examples of such a photosensitizer include triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, and 2-dimethylaminobenzoic acid 2-.
Examples include amines such as ethylhexyl. When such a photosensitizer is used, the amount is 0.01 to 10.0, preferably 0.1 to 5.0 parts by weight, and most preferably 100 parts by weight of each composition of the present invention. 0.2-3.0
It may be in the range of parts by weight or degree.

Further, the composition of the present invention may contain various known non-reactive polymers, organic pigments,
Inorganic pigments, inorganic fillers, organic fillers, coupling agents,
A tackifier, a leveling agent, a plasticizer, an antioxidant, an ultraviolet absorber, a flame retardant, a dye, and the like can be appropriately used in combination.

To prepare a powder coating containing the composition of the present invention from each of the above-mentioned components, in addition to the compound (A) and the compound (B), if necessary, a photopolymerization initiator and other additives After the dry blending, the kneaded product obtained by performing melt kneading using a known and customary kneading machine may be subjected to various processes such as coarse pulverization, fine pulverization and classification.

The powder coating containing the composition of the present invention thus prepared can be applied to various known and commonly used substrates. Representative of such substrates are iron,
Various metal bases such as copper, aluminum, lead or their alloys; plastic bases such as polyvinyl chloride, acrylic resin, polycarbonate resin, ABS resin, polyethylene terephthalate, polyethylene, polypropylene; use glass, tile or cement Inorganic bases such as various ceramic bases obtained by the above method; woody bases such as wood and various plywood; various bases such as paper and fiber.

The powder coating containing the composition of the present invention is excellent in curability at low temperatures, and is particularly suitable for coating substrates having poor heat resistance such as various plastics or wood-based substrates. Can be used effectively.

In order to apply the powder coating material thus obtained to a substrate as described above, a known coating method such as an electrostatic coating method or a fluid immersion method is applied, followed by heating and melting to obtain a smooth surface. An active energy ray may be irradiated after forming an uncured film. The heating conditions at that time are appropriately selected according to the softening point of the composition (S) or the type of the substrate. The heating temperature is generally 60 to 140 ° C., preferably 70 to 120 ° C., and the heating time is generally 3 to 3
It is 0 minute, preferably about 5 to 20 minutes. In this way, a cured coating film can be obtained by immediately irradiating with active energy rays in the state of being heated and melted.

As the active energy rays used for curing, various kinds of rays such as ultraviolet rays, visible rays, electron beams and the like can be used, and they can be cured in any atmosphere of air or inert gas. Of these active energy rays, ultraviolet rays are most preferred. As a light source of ultraviolet or visible light, for example, low-pressure mercury lamp, high-pressure mercury lamp, ultra-high-pressure mercury lamp, metal halide lamp, chemical lamp, black light lamp,
Mercury-xenon lamps, excimer lamps, short arc lamps, helium / cadmium lasers, argon lasers, excimer lasers, sunlight and the like can be used.

[0098]

Next, the present invention will be described more specifically with reference examples, examples and comparative examples, but the present invention is by no means limited to these examples. In the following, all parts and percentages are by weight unless otherwise specified.

Reference Example 1 [Preparation Example of Compound (A)] In a reaction vessel equipped with a stirrer, a thermometer, a condenser, a dropping funnel, and a nitrogen inlet tube, 600 parts of xylene was charged and stirred under nitrogen gas. The temperature was raised to 130 ° C. Then, at the same temperature, 30
0 parts, 500 parts of n-butyl methacrylate, 200 parts of glycidyl methacrylate, 50 parts of tert-butyl peroxy-2-ethylhexanoate, di-t
A mixture consisting of 5 parts of tert-butyl peroxide and 66 parts of xylene was added dropwise over 5 hours. After completion of the dropping, heating and stirring were performed at the same temperature for 10 hours to obtain a solution of a polymer containing an epoxy group. Then 100 ° C
And the distillation of xylene was started under reduced pressure. Gradually 1
The temperature was raised to 70 ° C to completely remove xylene, and the softening point was 1
A solid resin having a number average molecular weight of 2,700 and a weight average molecular weight of 6,100 at 00 ° C. was obtained.

100 parts of the solid resin thus obtained, N
22.3 of-(5-carboxy) pentylmaleimide
, A mixture consisting of 0.24 parts of triphenylphosphine and 0.12 parts of hydroquinone monomethyl ether was charged into the same reactor as above, and stirred at 105 ° C. for 1.5 hours while stirring under a stream of nitrogen gas. The acid value was 4.6 mg KOH / g resin and the softening point was 98.
A maleimide group-containing acrylic resin containing about 1.7% by weight of unreacted N- (5-carboxy) pentylmaleimide having a weight average molecular weight in terms of polystyrene of 6,500 as measured by GPC at 0 ° C. was obtained. Hereinafter, this resin is abbreviated as compound (A-1).

Reference Example 2 [Preparation Example of Compound (B)] A reaction vessel equipped with a thermometer, a stirrer, a nitrogen inlet tube and a condenser was charged with 520 of 1,6-hexanediol.
Parts, 62 parts of ethylene glycol, 296 of fumaric acid
Parts, 407 parts of terephthalic acid, 0.56 parts of dibutyltin oxide and 0.25 parts of tert-butylhydroquinone. Heating and stirring were started while blowing nitrogen gas below the liquid level of the mixture. 100 ° C to 22
Gradually raise the temperature to 5 ° C over 6 hours, and further increase to 225 ° C.
The heating and stirring are continued for 2 hours, and the acid value is 11.5 m.
The dehydration-condensation reaction was performed until gKOH / g resin was obtained. Next, the temperature was lowered to 180 ° C., and the condensation reaction was continued under reduced pressure for 1 hour, and the acid value was 5.0 mgKOH / g resin,
The softening point measured by the ring and ball method is 95 ° C., the number average molecular weight in terms of polystyrene measured by GPC is 6,900,
An unsaturated polyester resin having a weight average molecular weight of 22,500 and containing 2.2 mol of double bonds per 1,000 g of the resin was obtained. Hereinafter, this resin is referred to as a compound (B-
Abbreviated as 1).

REFERENCE EXAMPLE 3 [Same as above] In the same reaction vessel as in Reference Example 1, 168.2 g (1.0 mol) of hexamethylene diisocyanate, 0.4 g (0.64 mmol) of dibutyltin dilaurate,
900 g of chloroform was charged, and the temperature was raised to 55 ° C. while stirring under a stream of nitrogen gas. Then, at the same temperature, 232.3 of 4-hydroxybutyl vinyl ether
Grams (2.0 moles) were added dropwise over 3 hours. After completion of the dropwise addition, the mixture was further stirred at the same temperature for 5 hours, and the formed precipitate was separated by filtration, washed with n-heptane, and dried under reduced pressure to give a pale yellow powder having a melting point of 91 to 100 ° C. To give an addition product of hexamethylene diisocyanate and 4-hydroxybutyl vinyl ether. Hereinafter, this is abbreviated as compound (B-2).

Example 1 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5,
5] The following formula (II) synthesized by an esterification reaction between undecane and N- (5-carboxy) pentylmaleimide:

[0104]

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1,000 parts of a bismaleimide compound having a melting point of 81 to 83 ° C. [hereinafter, abbreviated as compound (A-2)] represented by the following formula: Compound (B-1) prepared in Reference Example 2 described above. 1,000 parts and “Modaflow P-
After mixing 20 parts of III (a flow modifier manufactured by Monsanto Co., USA) with a "Henschel mixer" for 2 minutes, using "Bus Conider PR-46" (single screw extruder manufactured by Bus, Switzerland). After melt-kneading and cooling, coarse pulverization and fine pulverization were performed. The resulting finely pulverized product was passed through a 150-mesh stainless steel wire mesh to obtain a powder coating having an average particle size of 40 μm. Powder coating prepared in this way,
An acrylic urethane-based white cured coating film was previously formed using an electrostatic coating machine, and the coating film surface was # 4
After coating on a mild steel plate having a thickness of 0.8 mm polished with a sandpaper of No. 00, the applied coating was heated and melted in a hot air dryer at an ambient temperature of 120 ° C. Then 12
Using a 0 W high-pressure mercury lamp, irradiation was performed once in the air with an ultraviolet irradiation device at a conveyor speed of 3 m / min to obtain a cured coating film having a thickness of 50 μm.

The pencil hardness of the obtained coating film was as high as H, and the surface roughness (expressed as an average value of the heights between peaks and valleys of the coating film surface) measured with a surface roughness measuring device. ) Is 3 μm
And small and excellent appearance. The color change (Δb value) after leaving the obtained coating film in a hot air dryer at 80 ° C. for 48 hours was as small as 0.5, and it was confirmed that the coating film was excellent in heat-resistant yellowing. The softening point of the composition obtained by melting and mixing 10 parts of the compound (A-2) and 10 parts of the compound (B-1) was 90 ° C.

Examples 2 to 4 The average particle size was determined in the same manner as in Example 1 except that the amounts of the compounds (A), (B) and other additives shown in Table 1 were used. Each clear powder coating having a diameter of about 40 μm was prepared, applied and cured in the same manner as in Example 1, and the cured coating film obtained was evaluated. The results are summarized in the same table.

Comparative Example 1 A compound having an average particle size of about 40 μm was prepared in the same manner as in Example 1 except that the amounts of the compound (B) and other additives shown in Table 1 were used. A clear powder coating was prepared, coated and cured in the same manner as in Example 1, and the cured coating film obtained was evaluated. The results are summarized in the same table.

[0109]

[Table 1] Table 1

(Footnote to Table 1) Compound (A-3): 3,
9-bis (2-hydroxy-1,1-dimethylethyl)
The following formula (III) synthesized by an esterification reaction between -2,4,8,10-tetraoxaspiro [5,5] undecane and N-carboxymethylmaleimide

[0111]

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A bismaleimide compound having a melting point of 92 to 95 ° C.

Compound (A-4): The following formula (IV) synthesized by the reaction of 4,9-dioxaundecane-1,12-diamine and maleic anhydride

[0114]

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A bismaleimide compound having a melting point of 68 to 70 ° C.

Irgacure-184: a photopolymerization initiator manufactured by Ciba Geigy, Switzerland. Softening point of composition (S): For Examples 1 to 4, the softening point of a composition obtained by melt-mixing only the compound (A) component and the compound (B) component at the weight ratio shown in the same table. Was measured, and for Comparative Example 1, the compound (B-1) and the compound (B-1)
Only the softening point of a composition obtained by melt-mixing only the components at the weight ratios shown in the same table was measured.

From the above results, the powder coating obtained from the composition of the present invention is excellent in curability, hardness and smoothness even if the photopolymerization initiator is added or added in a small amount. It is clear that a cured coating film having excellent heat yellowing resistance is obtained.

[0118]

From the composition for an energy ray-curable powder coating of the present invention, a powder coating excellent in curability can be obtained, and the powder coating has hardness, smoothness, and heat resistance yellow. Gives cured coatings with excellent denaturation.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 5/03 C09D 5/03 135/00 135/00 201/02 201/02 (72) Inventor Liner ・Bee Flings Pet Casser Strasse 16A 12307 F-term (reference) 4J011 QA08 QA13 QA19 QA24 QA39 QB02 QB03 QB12 QB14 QB16 QB19 QB24 SA01 SA21 SA31 SA41 SA51 SA63 SA64 UA01 VA02 AB01 A02A01 AB02 AB06 AB07 AB08 AB10 AB15 AB16 AB18 AB23 AB24 AB25 AB32 AB34 AC02 AC03 AC04 AC06 AC08 AE01 AE04 AG01 AG03 AG04 AG23 AG24 AG27 AG32 AG33 BA03 BA04 BA13 BA17 BA20 BA23 CC03 CD08 4J038 FA061 FA062 FA071 FA072 FA181 FA182 FA201 FA202 FA202 FA201 FA271 FA272 FA281 FA282 GA01 GA08 NA01 NA11 PA02 PA17 PC02 PC03 PC06 PC08

Claims (7)

[Claims] 1. A compound (A) containing two or more maleimide groups and a compound (B) containing an ethylenically unsaturated double bond copolymerizable with the maleimide group contained in the compound (A) ) As an essential component, and the composition (S) obtained by melt-blending the compound (A) and the compound (B) has a softening point (ring and ball method) of 60 to 13.
A composition for an energy ray-curable powder coating material, which is at 0 ° C. 2. The compound (A) wherein a divalent or higher valent organic group containing a spiro ring structure having an ether oxygen atom in the ring and two or more maleimide groups are bonded by a carbon-nitrogen bond. The powder coating composition according to claim 1, wherein the compound has a melting point of 40 ° C. or higher. 3. The compound (A) in which a divalent or higher valent organic group containing an ether bond derived from an oxymethylene unit and two or more maleimide groups are bonded by a carbon-nitrogen bond, The powder coating composition according to claim 1, which is a compound having a melting point of 40 ° C or higher. 4. The compound (A) having a softening point of 60
The composition for a powder coating according to claim 1, which is a polymer having a temperature of up to 130C. 5. The powder coating composition according to claim 4, wherein the polymer is an acrylic resin. 6. The compound (B) containing at least one double bond selected from the group consisting of an acryloyl group, a methacryloyl group, a vinyl ether group and an unsaturated dicarboxylic acid ester group. Item 1
The composition for a powder coating according to the above. 7. The compound (B) is at least one selected from the group consisting of acrylic resins, saturated polyester resins, unsaturated polyester resins and polyurethane resins, each having a softening point of 60 to 130 ° C. The composition for a powder coating according to claim 1 or 6.