JP2006249223A - Primer composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a primer composition capable of exhibiting excellent adhesivity to nylon, polycarbonate and other various substrates. <P>SOLUTION: This primer composition comprises a urethane prepolymer and/or a thermoplastic polyurethane, an epoxy resin, a ketimine compound having a ketimine (C=N) bond derived from a ketone or aldehyde and an amine, and a solvent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a primer composition.

In recent years, nylon and polycarbonate are mainly used for plastic molded articles from the viewpoint of impact resistance, heat resistance, weather resistance, and the like. When adhering such a molded product, it is necessary to apply the adhesive after applying a primer to the surface of the molded product in advance, because an adhesive alone cannot exert a sufficient adhesive force.
Examples of the primer used for nylon and polycarbonate include a primer containing an olefin polymer. For example, Patent Document 1 states that “a propylene random copolymer obtained by copolymerizing propylene and another α-olefin in the presence of a metallocene catalyst has a chlorine content of 10 to 40% by weight. Binder resin composition characterized by comprising a chlorinated propylene random copolymer having a weight average molecular weight of 3000 to 250,000, a stabilizer and an organic solvent has been proposed (see Patent Document 1). .

JP 2003-321588 A

  However, even when the primer described in Patent Document 1 is used, it is difficult to obtain a desired adhesive force. Further, heating was necessary to exert the adhesive force.

Accordingly, an object of the present invention is to provide a primer composition capable of exhibiting excellent adhesion to various substrates such as nylon and polycarbonate.
Another object of the present invention is to provide a primer composition that can be cured rapidly at room temperature and has excellent workability in addition to the above characteristics.

As a result of diligent study, the present inventor has found that, when a urethane prepolymer and / or thermoplastic polyurethane, an epoxy resin, a ketimine compound, and a solvent are contained as components of the primer composition, various materials including nylon and polycarbonate are used. It has been found that the primer composition can exhibit excellent adhesion to the substrate. In addition, it was found that when an epoxy resin that is solid at room temperature and has an epoxy equivalent of 350 or more can be cured quickly at room temperature, it becomes a primer composition excellent in workability.
The present inventor completed the present invention based on these findings.

（式中、Ｒ¹はメチル基または水素原子を表し、Ｒ²はメチル基またはエチル基を表し、Ｒ³は水素原子、メチル基またはエチル基を表し、Ｒ⁴は炭素数１〜６のアルキル基を表し、Ｒ¹およびＲ⁴は結合して環を形成していてもよく、Ｒ²およびＲ⁴は結合して環を形成していてもよい。Ｒ⁵はカルボニル炭素のα位に分岐状炭化水素基もしくは環状炭化水素基を有しない炭素数２以上の炭化水素基または水素原子を表し、Ｒ⁶はカルボニル炭素のα位に分岐状炭化水素基もしくは環状炭化水素基を有しない炭素数２以上の炭化水素基を表す。）
（８）更に、前記ケチミン化合物の加水分解触媒を含有する上記（１）〜（７）のいずれかに記載のプライマー組成物。 That is, the present invention provides the following (1) to (8).
(1) urethane prepolymer and / or thermoplastic polyurethane;
Epoxy resin,
A ketimine compound having a ketimine (C = N) bond derived from a ketone or aldehyde and an amine;
A primer composition containing a solvent.
(2) The primer composition according to (1), wherein the urethane prepolymer and / or thermoplastic polyurethane has a polycarbonate in its skeleton.
(3) The above (1) or (), wherein the polyisocyanate compound constituting the urethane prepolymer and / or thermoplastic polyurethane has an isocyanate (NCO) group bonded to an aliphatic secondary carbon or an aliphatic tertiary carbon. The primer composition as described in 2).
(4) The primer composition according to any one of (1) to (3), wherein the epoxy resin is solid at room temperature and has an epoxy equivalent of 350 or more.
(5) The primer composition according to any one of (1) to (4), wherein the epoxy resin is a rubber-modified epoxy resin.
(6) The primer composition according to any one of (1) to (5), wherein the epoxy resin has an acetoacetate group in the molecule.
(7) The primer composition according to any one of (1) to (6), wherein the ketone or aldehyde is a compound represented by the following formula (1) or (2).

(Wherein R ¹ represents a methyl group or a hydrogen atom, R ² represents a methyl group or an ethyl group, R ³ represents a hydrogen atom, a methyl group or an ethyl group, and R ⁴ represents an alkyl having 1 to 6 carbon atoms. R ¹ and R ⁴ may be bonded to form a ring, R ² and R ⁴ may be bonded to form a ring, and R ⁵ is branched to the α-position of the carbonyl carbon. Represents a hydrocarbon group having 2 or more carbon atoms or a hydrogen atom having no cyclic hydrocarbon group or a cyclic hydrocarbon group, and R ⁶ is a carbon number not having a branched hydrocarbon group or a cyclic hydrocarbon group at the α-position of the carbonyl carbon. Represents two or more hydrocarbon groups.)
(8) The primer composition according to any one of (1) to (7), further comprising a hydrolysis catalyst for the ketimine compound.

  The primer composition of the present invention can exhibit excellent adhesion to various substrates such as nylon and polycarbonate. Moreover, when containing a specific epoxy resin, in addition to said characteristic, it can harden | cure rapidly at normal temperature and is excellent also in workability | operativity.

Hereinafter, the present invention will be described in more detail.
The primer composition of the present invention (hereinafter also referred to as “the composition of the present invention”) is a ketimine derived from a urethane prepolymer and / or thermoplastic polyurethane, an epoxy resin, a ketone or an aldehyde, and an amine (C = N) A primer composition containing a ketimine compound having a bond and a solvent.
Next, each component used for the composition of this invention is explained in full detail.

<Urethane prepolymer and thermoplastic polyurethane>
The urethane prepolymer used in the composition of the present invention is a polyol compound and an excess polyisocyanate compound (that is, an excess of NCO groups with respect to hydroxy (OH) groups), as in a normal one-pack type polyurethane resin composition. Is a reaction product obtained by reacting, and generally contains 0.5 to 10% by mass of NCO groups at the molecular ends.

The polyisocyanate compound for producing such a urethane prepolymer is not particularly limited as long as it is a compound having two or more NCO groups in the molecule. Specific examples thereof include 2,4-tolylene diisocyanate (2,4 -TDI), 2,6-tolylene diisocyanate (2,6-TDI), 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI) , 1,4-phenylene diisocyanate, xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), tolidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI) and the like; hexamethylene diisocyanate ( HDI), G Hexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane aliphatic polyisocyanates such as isocyanate methyl (NBDI); trans-cyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), H ₆ XDI (hydrogenated XDI), Cycloaliphatic polyisocyanates such as H ₁₂ MDI (hydrogenated MDI) and H ₆ TDI (hydrogenated TDI); polyisocyanate compounds such as polymethylene polyphenylene polyisocyanate; carbodiimide-modified polyisocyanates of these isocyanate compounds; these isocyanate compounds These are isocyanurate-modified polyisocyanates, and these may be used alone or in combination of two or more.
A monoisocyanate compound having only one NCO group in the molecule can also be used by mixing with a diisocyanate compound or the like.

  As the polyisocyanate compound, those having an isocyanate (NCO) group bonded to an aliphatic secondary carbon or an aliphatic tertiary carbon have a long pot life in a state where a curing agent is mixed, and are resistant to moisture and heat. Is preferably used from the viewpoint of further improving. Specific examples of such a polyisocyanate compound include TMXDI, IPDI, hydrogenated MDI, and hydrogenated TDI.

  In addition, the polyol compound that produces such a urethane prepolymer is not particularly limited in molecular weight and skeleton as long as it is a compound having two or more OH groups. Specific examples thereof include low molecular weight polyhydric alcohols. , Polycarbonate polyol, polyether polyol, polyester polyol, other polyols, and mixed polyols thereof.

  Here, specific examples of the low-molecular polyhydric alcohols include ethylene glycol (EG), diethylene glycol, propylene glycol (PG), dipropylene glycol, and (1,3- or 1,4-) butanediol. Low molecular polyols such as pentanediol, neopentyl glycol, hexanediol, cyclohexanedimethanol, glycerin, 1,1,1-trimethylolpropane (TMP), 1,2,5-hexanetriol, pentaerythritol; Saccharides; and the like.

The polycarbonate polyol is obtained, for example, by a transesterification reaction between a polyol compound and a dialkyl carbonate. Specific examples of the polyol compound include 1,6-hexanediol, 1,4-butanediol, 1,5-pentanediol, and the like.
As said dialkyl carbonate, the dialkyl carbonate represented by a following formula can be used, for example.

R ⁷ and R ⁸ are each independently an alkyl group having 12 or less carbon atoms.

  Specific examples of the dialkyl carbonate include dimethyl carbonate and diethyl carbonate.

  Catalysts suitable for the transesterification reaction between the polyol compound and the dialkyl carbonate include alkali metal or alkaline earth metal hydroxides such as sodium hydroxide and potassium hydroxide, sodium methylate, potassium methylate and titanium. Examples thereof include metal alcoholates such as tetraisopropylate and zirconium tetraisopropylate. Of these, titanium tetraisopropylate and zirconium tetraisopropylate are preferred.

  Polyether polyols and polyester polyols are usually derived from the above low-molecular polyhydric alcohols, but those derived from aromatic diols can also be suitably used in the present invention. Specific examples of the aromatic diols include xylylene glycol, 1,4-benzenedimethanol, styrene glycol, 4,4′-dihydroxyethylphenol; bisphenol A structure (4, 4'-dihydroxyphenylpropane), bisphenol F structure (4,4'-dihydroxyphenylmethane), brominated bisphenol A structure, hydrogenated bisphenol A structure, bisphenol S structure, and bisphenol AF structure. It is done.

As the polyether polyol derived from the low molecular weight polyhydric alcohols and / or aromatic diols, at least one selected from the compounds exemplified as the low molecular weight polyhydric alcohols and the aromatic diols, ethylene oxide And a polyol obtained by adding at least one selected from alkylene oxide such as propylene oxide and butylene oxide (tetramethylene oxide) and styrene oxide.
Specific examples of such polyether polyols include polyethylene glycol, polypropylene glycol (PPG), ethylene oxide / propylene oxide copolymer, polytetramethylene ether glycol (PTMEG), sorbitol-based polyol, and the like.
Specific examples of polyether polyols having a bisphenol skeleton include polyether polyols obtained by adding ethylene oxide and / or propylene oxide to bisphenol A (4,4′-dihydroxyphenylpropane).

Similarly, examples of the polyester polyol include condensates (condensed polyester polyols) of the above low-molecular polyhydric alcohols and / or aromatic diols with polybasic carboxylic acids; lactone polyols; polycarbonate polyols; It is done.
Specific examples of the polybasic carboxylic acid that forms the condensed polyester polyol include glutaric acid, adipic acid, azelaic acid, pimelic acid, suberic acid, sebacic acid, terephthalic acid, isophthalic acid, dimer acid, Other low molecular carboxylic acids, oligomeric acids, castor oil, hydroxycarboxylic acids such as a reaction product of castor oil and ethylene glycol, and the like can be mentioned. Specific examples of the lactone-based polyol include ring-opening polymers such as propionlactone and valerolactone.
Examples of the polyester polyol having a bisphenol skeleton include condensed polyester polyols obtained by using a diol having a bisphenol skeleton instead of the low molecular polyhydric alcohols or together with the low molecular polyhydric alcohols. Specific examples include polyester polyols obtained from bisphenol A and castor oil, polyester polyols obtained from bisphenol A, castor oil, ethylene glycol, and propylene glycol.

  Specific examples of other polyols include acrylic polyols; polybutadiene polyols; polymer polyols having a carbon-carbon bond in the main chain skeleton such as hydrogenated polybutadiene polyols.

In the present invention, the various polyol compounds exemplified above may be used alone or in combination of two or more.
Among these, polycarbonate polyol is preferable from the viewpoint of improving the adhesion to the adherend surface, particularly the heat and moisture resistance.

  As described above, the urethane prepolymer used in the primer composition of the present invention is obtained by reacting a polyol compound with an excess of a polyisocyanate compound. Specific examples thereof include various polyols exemplified above. The thing by the combination of a compound and various polyisocyanate compounds is mentioned.

  The urethane prepolymer used in the present invention has a structure in which secondary carbon or tertiary carbon is bonded to all NCO groups in the molecule as represented by the following formula (3). It is preferable to use the primer composition obtained for the reason that the moisture and heat resistance is further improved after curing.

In the formula, p represents an integer of 2 or more, and R ⁹ , R ¹⁰ and R ¹¹ may each independently contain at least one heteroatom selected from the group consisting of O, N and S. It is an organic group, and R ¹⁰ may be a hydrogen atom. The plurality of R ⁹ and R ¹⁰ may be the same or different. Further, when R ¹⁰ is a hydrogen atom, R ⁹ and a part of R ¹⁰ may be bonded to form a ring.

Here, the organic group specifically includes, for example, a hydrocarbon group such as an alkyl group, a cycloalkyl group, an aryl group, and an alkylaryl group; and at least a heteroatom selected from the group consisting of O, N, and S And organic groups containing one group (for example, ether, carbonyl, amide, urea group (carbamide group), urethane bond, etc.). Among these, the organic group represented by R ⁹ and R ¹⁰ is preferably an alkyl group, and specifically, a methyl group is preferable.

Furthermore, in the present invention, the urethane prepolymer contains 10 to 90% by mass of a urethane prepolymer having a weight average molecular weight of 1500 or less and a functional group number of 3 or more. This is preferable because the density is increased and the heat and humidity resistance is further improved.
Here, as the “urethane prepolymer having a weight average molecular weight of 1500 or less and a functional group number of 3 or more”, for example, an adduct of the low-molecular polyhydric alcohol and a diisocyanate compound among the polyisocyanate compounds can be mentioned. Specifically, a TMXDI · TMP adduct synthesized from 1,1,1-trimethylolpropane (TMP) and tetramethylxylene diisocyanate (TMXDI) is preferable.
As such an adduct, Seicen 3174 manufactured by Nippon Cytec Industries, Inc. can be used as a commercial product. Further, the adduct is not necessarily an OH: NCO complete adduct, and may contain unreacted raw materials.

Next, the thermoplastic polyurethane used in the composition of the present invention will be described in detail.
In the thermoplastic polyurethane used in the composition of the present invention, an active hydrogen-containing compound containing a polyol compound and a polyisocyanate compound are mixed so that the molar ratio of NCO groups to active hydrogen is about 1/1, It is a linear polymer obtained by reaction.
When the composition of the present invention contains a thermoplastic polyurethane, it has excellent adhesion to an adherend and can have a sufficient pot life.

  As the polyisocyanate compound constituting the thermoplastic polyurethane, those similar to the polyisocyanate compound constituting the urethane prepolymer can be used. In particular, those having an isocyanate (NCO) group bonded to secondary carbon or tertiary carbon are preferred from the viewpoint of further improving the heat and moisture resistance.

  As a polyol compound which comprises the said thermoplastic polyurethane, the thing similar to the polyol compound which comprises the said urethane prepolymer can be used. In particular, the polycarbonate polyol is preferable from the viewpoint of improving the adhesion to the adherend surface, particularly the heat and moisture resistance.

Moreover, a polyol compound and an amine compound can also be used together as an active hydrogen containing compound made to react with the said polyisocyanate compound.
Examples of the amine compound include amines and alkanolamines. Specific examples of amines include xylylenediamine, ethylenediamine, and propanolamine. Specific examples of alkanolamines include ethanolamine and propanolamine.

  70-100 are preferable and, as for the JIS A hardness of the said thermoplastic polyurethane, 80-95 are more preferable. Within this range, the cured film is imparted with an appropriate hardness and excellent in impact resistance and adhesiveness.

<Epoxy resin>
The epoxy resin used in the primer composition of the present invention is not particularly limited as long as it is a resin composed of a compound having two or more oxirane rings (epoxy groups) in one molecule. The equivalent is preferably 350 or more. When such an epoxy resin is used, the resulting primer composition can be quickly cured at room temperature and has excellent workability.
Normally, the reaction rate between the epoxy group of the epoxy resin and the amino group of the ketimine compound is slower than the reaction rate of the NCO group of the urethane and the amino group of the ketimine compound, so it takes a long time to cure at room temperature. In some cases, heating is necessary. On the other hand, when the epoxy resin is used, the surface tack is eliminated after several minutes even at room temperature after coating. In view of these characteristics, the epoxy equivalent is more preferably 350 to 5000, and still more preferably 400 to 3000.

As the epoxy resin used in the present invention, a conventionally known epoxy resin can be used. Specifically, for example, bisphenol A type, bisphenol F type, brominated bisphenol A type, hydrogenated bisphenol A type, bisphenol S Type, bisphenol AF type, biphenyl type epoxy compound having bisphenyl group, polyalkylene glycol type, alkylene glycol type epoxy compound, epoxy compound having naphthalene ring, epoxy compound having fluorene group, etc. Glycidyl ether type epoxy resin;
Polyfunctional glycidyl ether type epoxy resins such as phenol novolak type, orthocresol novolak type, DPP novolak type, tris-hydroxyphenylmethane type, trifunctional type, tetraphenylolethane type, etc .;
Glycidyl ester type epoxy resin of synthetic fatty acid such as dimer acid;
N, N, N ′, N′-tetraglycidyldiaminodiphenylmethane (TGDDM), tetraglycidyl-m-xylylenediamine, triglycidyl-p-aminophenol, N, N-diglycidyl represented by the following formula (4) An aromatic epoxy resin having a glycidylamino group such as aniline;

Formula (5) epoxy compound having a tricyclo [5,2,1,0 ^2,6] decane ring represented by, specifically, for example, cresol or phenols, such as dicyclopentadiene and cresol An epoxy compound which can be obtained by a known production method of reacting epichlorohydrin after polymerization;

  In formula, m represents the integer of 0-15.

Epoxy resin having a sulfur atom in the main chain of epoxy resin represented by Flep 10 manufactured by Toray Rethiokol; Urethane-modified epoxy resin having urethane bond; rubber such as polybutadiene, liquid polyacrylonitrile-butadiene rubber, acrylonitrile butadiene rubber (NBR) Rubber modified epoxy resin containing bisphenol A type epoxy resin, bisphenol F type epoxy resin, sorbitol type epoxy resin, polyglycerol type epoxy resin, pentaerythritol type epoxy resin, trimethylolpropane type epoxy resin, etc. And epoxy resin having a group.
These may be used alone or in combination of two or more.

  Of the various epoxy resins exemplified above, use of an epoxy resin having an aromatic ring in the skeleton increases the heat resistance of the resulting primer composition and improves the adhesion of the metal vapor-deposited film to the plastic molded product. It is preferable from the point. As such an epoxy resin, commercially available products such as Epicoat 828, Epicoat 154, and Epicoat 630 manufactured by Japan Epoxy Resin Co., Ltd. can be used.

  Moreover, a rubber-modified epoxy resin is preferable from the viewpoint of excellent adhesion to the adherend surface. The rubber-modified epoxy resin is obtained by reacting an epoxy resin with both ends of rubber having functional groups at both ends.

  Moreover, the epoxy resin which has an acetoacetate group in a molecule | numerator from the point which can harden | cure the composition obtained more rapidly is preferable. An epoxy resin having an acetoacetate group in the molecule is a compound having a transesterification reaction between a low molecular weight compound having an acylacetate skeleton and a hydroxy group in the epoxy resin, or a 1,3-diketone group having a substituent at the terminal. And a method of reacting the hydroxy group in the epoxy resin.

  The content of the epoxy resin is preferably 10 to 90% by mass and more preferably 30 to 80% by mass with respect to the total mass of the urethane prepolymer and / or the thermoplastic polyurethane and the epoxy resin. .

<Ketimine compound>
The ketimine compound used in the primer composition of the present invention is a latent curing agent for the urethane prepolymer and epoxy resin described above. That is, the ketimine compound does not react as it is, but is hydrolyzed by moisture in the air to produce an amino group or an imino group, and reacts with the NCO group of the urethane prepolymer and the epoxy group of the epoxy resin to be cured. Therefore, the composition of the present invention can be a one-component primer composition.

  The ketimine compound suitably used in the composition of the present invention is a compound having a ketimine bond derived from a ketone or aldehyde and an amine. In the present specification, the ketimine compound is used in a sense including an aldimine having a —HC═N bond.

  As the ketone or aldehyde used for the synthesis of such a ketimine compound, widely known ones can be used, and examples thereof include compounds represented by the following formula (1) or (2).

In the above formula (1), R ¹ represents a methyl group or a hydrogen atom, R ² represents a methyl group or an ethyl group, R ³ represents a hydrogen atom, a methyl group or an ethyl group, and R ⁴ represents 1 to 1 carbon atoms. Represents an alkyl group of 6; R ¹ and R ⁴ may be bonded to form a ring, and R ² and R ⁴ may be bonded to form a ring.
In the above formula (2), R ⁵ represents a hydrocarbon group having 2 or more carbon atoms or a hydrogen atom not having a branched hydrocarbon group or cyclic hydrocarbon group at the α-position of the carbonyl carbon, and R ⁶ represents an α of the carbonyl carbon. Represents a hydrocarbon group having 2 or more carbon atoms which does not have a branched hydrocarbon group or a cyclic hydrocarbon group at the position.

Specific examples of the compound represented by the above formula (1) include methyl-t-butylketone (MTBK), methylisopropylketone (MIPK), pivalaldehyde (trimethylacetaldehyde), and a carbonyl group having a branched carbon. Examples thereof include bonded isobutyraldehyde ((CH ₃ ) ₂ CHCHO), methylcyclohexanone, ethylcyclohexanone, methylcyclohexyl ketone, and the like. These may be used alone or in combination of two or more. Of these, MTBK and MIPK are preferred.

  Specific examples of the compound represented by the formula (2) include diethyl ketone, dipropyl ketone, dibutyl ketone, ethyl propyl ketone, ethyl butyl ketone, butyl propyl ketone, and ethyl isopropyl ketone. These may be used alone or in combination of two or more. Of these, diethyl ketone, dipropyl ketone, and dibutyl ketone are preferred.

  In addition, as the amine compound that can be used as a raw material for the synthesis of the ketimine compound, widely known compounds can be used, and a polyamine having two or more amino groups in the molecule is preferable, and reaction adjustment is easy. In view of the above, it is more preferably a polyamine represented by the following formula (6).

  In formula, n represents the integer of 2-6.

Specifically, ethylenediamine, propylenediamine, butylenediamine, diethylenetriamine, triethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexamethylenediamine, trimethylhexamethylenediamine, N-aminoethylpiperazine, 1,2 - diaminopropane, iminobispropylamine, methyl iminobispropylamine, polyamidoamine, isophorone diamine, a dimethylene amines polyether backbone _{H 2 N (CH 2 CH 2} O) 2 (CH 2) 2 NH 2 ( Jefa 1,5-diamino-2-methylpentane (MPMD, DuPont Japan) such as Mine EDR148, manufactured by Sun Techno Chemical Co., Ltd. Manufactured), m-xylylenediamine (MXDA), polyamidoamine (X2000, manufactured by Sanwa Chemical Co., Ltd.), isophoronediamine, 1,3-bisaminomethylcyclohexane (1,3BAC, manufactured by Mitsubishi Gas Chemical Company), 1- Examples include cyclohexylamino-3-aminopropane, 3-aminomethyl-3,3,5-trimethyl-cyclohexylamine, norbornane diamine (NBDA, manufactured by Mitsui Chemicals), which is a diamine having a norbornane skeleton, and these are used alone. Two or more types may be used in combination.
Of these, 1,3-bisaminomethylcyclohexane (1,3BAC), norbornanediamine (NBDA), m-xylylenediamine (MXDA), Jeffamine EDR148 (trade name), and polyamidoamine are preferable.

As described above, the ketimine compound suitably used in the composition of the present invention is a compound derived from a ketone or aldehyde and an amine, and is a combination of various ketones or aldehydes exemplified above and various amines. Is mentioned. In addition, those obtained from methyl isobutyl ketone (MIBK) and propylene diamine, those obtained from methyl ethyl ketone (MEK) and butylene diamine, those obtained from diethyl ketone and metaxylylene diamine (MXDA), etc. may be used. it can.
Such ketimine compounds can be reacted with ketones or aldehydes and amines heated to reflux in the absence of a solvent or in the presence of a solvent such as benzene, toluene, xylene, etc., while removing the water removed by azeotropic distillation. Can be obtained.

  In the present invention, the ketimine compound is a compound having a structure in which a branched carbon or a ring member carbon is bonded to the α-position of at least one of ketimine carbon or nitrogen, that is, a compound having a bulky group at the α-position of the ketimine bond. In the storage of the composition obtained by blending with the urethane prepolymer and / or the epoxy resin, that is, during the storage of the primer composition of the present invention, the urethane prepolymer and / or the epoxy resin and the ketimine. It is preferable because the reaction with the compound is suppressed and they can exist stably. Here, the ring member carbon may be carbon constituting an aromatic ring or carbon constituting an alicyclic ring.

  In such a ketimine compound, when a branched carbon or a ring member carbon is introduced into the α-position of the ketimine carbon, a ketone or an aldehyde having a branched hydrocarbon group or a cyclic hydrocarbon group at the α-position of the carbonyl carbon described above Is used.

Specific examples of the ketimine compound having a bulky group at the α-position of the ketimine bond include those obtained from methyl isopropyl ketone (MIPK) or methyl-t-butyl ketone (MTBK) and Jeffamine EDR148; MIPK or MTBK And 1,3-bisaminomethylcyclohexane (1,3BAC); obtained from MIPK or MTBK and norbornanediamine (NBDA); MIPK or MTBK and m-xylylenediamine (MXDA) Preferred examples include those obtained from MIPK or MTBK and polyamidoamine (X2000).
Among these, those obtained from MIPK or MTBK and 1,3BAC, those obtained from MIPK or MTBK and NBDA, those obtained from MIPK or MTBK and MXDA are the moisture resistance of the primer composition obtained. This is preferable because the thermal property is improved.

  The ketimine compound obtained from the combination of aldimine and polyamine specifically includes at least one aldehyde selected from the group consisting of pivalaldehyde, isobutyraldehyde and cyclohexanecarboxaldehyde, and norbornanediamine (NBDA). ), 1,3-bisaminomethylcyclohexane (1,3BAC), Jeffamine EDR148 and m-xylylenediamine (MXDA) in combination with at least one amine selected from the group consisting of Illustrated.

  In the present invention, the content of the ketimine compound is such that the equivalent ratio represented by (isocyanate group in the urethane prepolymer + epoxy group in the epoxy resin) / (ketimine bond in the ketimine compound) is 0.5. It is preferable to contain so that it may become -5.0, and it is more preferable to contain so that it may become 1.0-2.0.

<Solvent>
As the solvent used in the primer composition of the present invention, various conventionally known solvents can be used as long as they are inert with respect to the urethane prepolymer and / or thermoplastic polyurethane, epoxy resin and ketimine compound.
Specifically, aromatic hydrocarbons such as benzene, xylene and toluene; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; esters such as methyl acetate, ethyl acetate and butyl acetate; diethyl ether, tetrahydrofuran and dioxane Ethers; and the like. These may be used alone or in combination of two or more.
The solvent is preferably used after being sufficiently dried or dehydrated. Of these, ethyl acetate and toluene are preferred for reasons such as low boiling point and quick drying.

  In the present invention, the content of the solvent may be added so as to adjust the solid content concentration of the primer composition to 1 to 30%, preferably 2 to 20%. It is preferable because it is excellent.

In one preferred embodiment, the primer composition of the present invention contains a hydrolysis catalyst for the ketimine compound.
The hydrolysis catalyst used in the present invention is not particularly limited, and specific examples thereof include carboxylic acids such as 2-ethylhexanoic acid and oleic acid; phosphoric acids such as polyphosphoric acid, ethyl acid phosphate, and butyl acid phosphate; And organic metals such as dilaurate and dioctyltin dilaurate.
If such a hydrolysis catalyst is contained, when the primer composition of the present invention is applied to the surface of a plastic molded body, hydrolysis of the ketimine compound by moisture (water) is promoted, and workability and adhesion are improved. This is preferable because of improving the balance.

  In this invention, it is preferable that it is 0.01-30 mass parts with respect to 100 mass parts of said ketimine compounds, and, as for content of a hydrolysis catalyst, it is more preferable that it is 0.1-20 mass parts.

In one preferred embodiment, the primer composition of the present invention contains a silane coupling agent.
The silane coupling agent used in the present invention is not particularly limited, and specific examples thereof include amino silane, vinyl silane, epoxy silane, methacryl silane, isocyanate silane, ketimine silane, or a mixture or reaction product thereof, or these and polyisocyanate. And the like obtained by the reaction.

  The aminosilane is not particularly limited as long as it is a compound having an amino group or imino group and a hydrolyzable silicon-containing group. For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyl Methyldimethoxysilane, 3-aminopropylethyldiethoxysilane, bistrimethoxysilylpropylamine, bistriethoxysilylpropylamine, bismethoxydimethoxysilylpropylamine, bisethoxydiethoxysilylpropylamine, N-2- (aminoethyl) -3 -Aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, N-2- (aminoethyl)- 3-A Roh propyl ethyl diethoxy silane, and the like.

Examples of vinyl silane include vinyl trimethoxy silane, vinyl triethoxy silane, and tris- (2-methoxy ethoxy) vinyl silane.
Examples of the epoxy silane include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyldimethylethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β- (3,4-epoxycyclohexyl) ethylmethyl. Examples include dimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like.
Examples of methacrylic silane include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane.
Examples of the isocyanate silane include isocyanate propyl triethoxy silane and isocyanate propyl trimethoxy silane.
Examples of ketimine silanes include ketiminated propyltrimethoxysilane and ketiminated propyltriethoxysilane.

It is preferable that content of a silane coupling agent is 0.1-10 mass parts with respect to a total of 100 weight part of the said urethane prepolymer and / or thermoplastic polyurethane, and the said epoxy resin.
If the content of the silane coupling agent is within this range, the adhesion to the adherend becomes better, which is preferable.

  The primer composition of the present invention can contain various additives as required in addition to the above-mentioned various components within a range not impairing the object of the present invention. Examples of the additive include a filler, an anti-aging agent, an antioxidant, an antistatic agent, a flame retardant, an adhesiveness imparting agent, a dispersant, and a solvent.

  Examples of the filler include wax stone clay, kaolin clay, calcined clay; fumed silica, calcined silica, precipitated silica, ground silica, fused silica; diatomaceous earth; iron oxide, zinc oxide, titanium oxide, barium oxide, oxidized Magnesium; calcium carbonate, magnesium carbonate, zinc carbonate; organic or inorganic fillers such as carbon black; these fatty acids, resin acids, fatty acid ester treated products, and fatty acid ester urethane compound treated products.

Examples of the antiaging agent include hindered phenol compounds and hindered amine compounds.
Examples of the antioxidant include butylhydroxytoluene (BHT) and butylhydroxyanisole (BHA).
Examples of the antistatic agent include quaternary ammonium salts; hydrophilic compounds such as polyglycols and ethylene oxide derivatives.

Examples of the flame retardant include chloroalkyl phosphate, dimethyl / methylphosphonate, bromine / phosphorus compound, ammonium polyphosphate, neopentyl bromide-polyether, and brominated polyether.
Examples of the adhesion-imparting agent include terpene resins, phenol resins, terpene-phenol resins, rosin resins, xylene resins, and epoxy resins.
The above additives can be used in combination as appropriate.

  The method for producing the primer composition of the present invention from the above components is not particularly limited. For example, the above-mentioned urethane prepolymer and / or thermoplastic polyurethane, epoxy resin, ketimine compound and various additions added as desired. The method of mixing an agent with a roll, a kneader, an extruder, a universal stirrer etc. in a solvent is mentioned.

The primer composition of the present invention thus obtained is used by applying to the surface of various substrates.
Various methods can be used as the coating method, and examples thereof include bar coater coating, spin coating, spray coating, and dip coating.

  The primer composition of the present invention can exhibit excellent adhesion to various substrates such as nylon and polycarbonate. Moreover, when containing a specific epoxy resin, in addition to said characteristic, it can harden | cure rapidly at normal temperature and is excellent also in workability | operativity.

Since the primer composition of the present invention has the above-described excellent characteristics, it can be used for bonding various resin parts. Moreover, the primer composition of this invention can be used also for adhesion | attachment of a coated steel plate, a metal vapor deposition film, etc.
Therefore, the primer composition of the present invention is suitably used for a wide range of applications such as for automobiles, buildings, electronic devices, and communication devices.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.
<Urethane prepolymer>
As urethane prepolymer, polycarbonate polyol (Placcel CD220, manufactured by Daicel Chemical Industries, Ltd., weight average molecular weight 2000) and tetramethylxylylene diisocyanate (TMXDI, manufactured by Nihon Cytec Industries, Ltd.) are used as isocyanate group / hydroxy group (hydroxy group 1). 3 groups of NCO groups synthesized by mixing at a quantitative ratio of (number of isocyanate groups per unit) = 2.0 and reacting with stirring in a nitrogen stream at 85 ° C. for 15 hours in the presence of a tin catalyst. A polycarbonate-TMXDI urethane prepolymer containing 5% by mass was used.

<Thermoplastic polyurethane 1>
As the thermoplastic polyurethane 1, the urethane prepolymer obtained by the above method and methyl ethyl ketone (manufactured by Kanto Chemical Co., Inc.) are mixed at a mass ratio of 10/90, and metaxylylenediamine (MXDA, manufactured by Mitsubishi Chemical Co., Ltd.) with stirring. ) Was added so that the NCO group of the urethane prepolymer and the active hydrogen of the amino group of MXDA were equimolar, and reacted with stirring at room temperature for 10 minutes, and TMXDI thermoplastic polyurethane was used.

<Thermoplastic polyurethane 2>
As the thermoplastic polyurethane 2, a polyester-MDI thermoplastic polyurethane (Desmocol 400, manufactured by Bayer, JIS A hardness 90) obtained by reacting a polyester polyol and MDI was used.

<Epoxy resin 1>
As epoxy resin 1, general-purpose bisphenol A type epoxy resin (EP4100E, manufactured by Asahi Denka Kogyo Co., Ltd., epoxy equivalent 188) was used.

<Epoxy resin 2>
As the epoxy resin 2, a solid bisphenol A type epoxy resin (Epicoat 1001, manufactured by Japan Epoxy Resin Co., Ltd., epoxy equivalent 481) was used.

<Epoxy resin 3>
As the epoxy resin 3, NBR modified epoxy resin (EPR1415-1, manufactured by Asahi Denka Kogyo Co., Ltd., epoxy equivalent 400) was used.

<Epoxy resin 4>
As the epoxy resin 4, NBR modified epoxy resin (EPR1508, manufactured by Asahi Denka Kogyo Co., Ltd., epoxy equivalent 290) was used.

<Epoxy resin 5>
Trimethylolpropane polyglycidyl ether (Denacol EX-321, manufactured by Nagase ChemteX Corp.) and t-butyl acetoacetate (manufactured by Kanto Chemical Co., Ltd.), acetoacetate group and trimethylolpropane polyglycidyl in t-butyl acetoacetate The mixture was mixed so that the molar ratio (acetoacetate group / OH group) to OH group in ether was 1.0, and the mixture was heated and stirred at 140 ° C. for 4 hours in the presence of an isopropoxy titanate catalyst (manufactured by Matsumoto Trading Co., Ltd.). An epoxy resin 5 having an acetoacetate group in the molecule (epoxy equivalent 178) was obtained.

<Ketimine Compound 1>
Norbornanediamine (NBDA, manufactured by Mitsui Chemicals) and methyl isopropyl ketone (MIPK, manufactured by Kuraray Co., Ltd.) are mixed at an equivalent ratio of 1 / 1.5, and heated at 150 ° C. for 10 hours while removing the water produced. Stir. The reaction was terminated when the generated water reached the theoretical amount, and excess MIPK was removed under reduced pressure to obtain a ketimine compound 1 represented by the following formula (7).

<Ketimine compound 2>
A ketimine compound 2 represented by the following formula (8) was synthesized by the same method as the ketimine compound 1 except that MIPK was changed to diethyl ketone.

<Solvent>
Methyl ethyl ketone (manufactured by Kanto Chemical Co., Inc.) was used as the solvent.

<Hydrolysis catalyst>
As a hydrolysis catalyst, oleic acid (LUNAC OA, manufactured by Kao Corporation) was used.

(Examples 1-7, Comparative Examples 1-2)
Each component mentioned above was mix | blended by the component ratio (mass part) shown in the following Table 1, and each composition was prepared. About each obtained composition, the tack | tuck after application | coating and evaluation of adhesiveness were performed by the method shown below.
The results are shown in Table 1 below.

<Tack after application>
The composition obtained was applied to the surface of a nylon plate (RENY1022H, manufactured by Mitsubishi Engineering Plastics) and allowed to stand at room temperature for 5 minutes, and then the tack when the coated surface was touched with a finger was observed.
“◯” indicates that there was no tack at all, “Δ” indicates that there was a little tack remaining, and “x” indicates that much tack remained.

<Adhesion>
The adhesion was evaluated by a cross-cut tape peeling test.
Each composition obtained was applied to the surface of a molded article made of nylon (RENY1022H, manufactured by Mitsubishi Engineering Plastics), dried at room temperature for 10 minutes, and then 100 pieces of 1 mm substrate on the effective surface of the specimen. (10 × 10), cellophane adhesive tape (width 18mm) is completely attached to the base, and immediately keep one end of the tape at a right angle, pull it away instantaneously, and the number of bases that remain without being completely peeled off I investigated. It is most preferable that the number of base meshes remaining without being completely peeled is 100, that is, those having not been peeled at all, but 90 or more is a practical level.

As is apparent from the results shown in Table 1, the composition comprising the thermoplastic polyurethane and the solvent (Comparative Example 1) had no tack after application, but had poor adhesion. In addition, the composition (Comparative Example 2) containing no general purpose bisphenol A type epoxy resin, ketimine compound, solvent and hydrolysis catalyst, which did not contain urethane prepolymer or thermoplastic polyurethane, had a lot of tack after coating. This is thought to be because the general-purpose bisphenol A type epoxy resin cannot be cured in a short time at room temperature. Also, the adhesion was poor.
On the other hand, the compositions of Examples 1 to 7 had very little tack after coating and were extremely excellent in adhesion.

Claims (8)

A urethane prepolymer and / or a thermoplastic polyurethane;
Epoxy resin,
A ketimine compound having a ketimine (C = N) bond derived from a ketone or aldehyde and an amine;
A primer composition containing a solvent.   The primer composition according to claim 1, wherein the urethane prepolymer and / or the thermoplastic polyurethane has a polycarbonate in a skeleton.   The primer according to claim 1 or 2, wherein the polyisocyanate compound constituting the urethane prepolymer and / or thermoplastic polyurethane has an isocyanate (NCO) group bonded to an aliphatic secondary carbon or an aliphatic tertiary carbon. Composition.   The primer composition according to claim 1, wherein the epoxy resin is solid at room temperature and has an epoxy equivalent of 350 or more.   The primer composition according to claim 1, wherein the epoxy resin is a rubber-modified epoxy resin.   The primer composition according to any one of claims 1 to 5, wherein the epoxy resin has an acetoacetate group in the molecule. The primer composition according to any one of claims 1 to 6, wherein the ketone or aldehyde is a compound represented by the following formula (1) or (2).

(Wherein R ¹ represents a methyl group or a hydrogen atom, R ² represents a methyl group or an ethyl group, R ³ represents a hydrogen atom, a methyl group or an ethyl group, and R ⁴ represents an alkyl having 1 to 6 carbon atoms. R ¹ and R ⁴ may be bonded to form a ring, R ² and R ⁴ may be bonded to form a ring, and R ⁵ is branched to the α-position of the carbonyl carbon. Represents a hydrocarbon group having 2 or more carbon atoms or a hydrogen atom having no cyclic hydrocarbon group or a cyclic hydrocarbon group, and R ⁶ is a carbon number not having a branched hydrocarbon group or a cyclic hydrocarbon group at the α-position of the carbonyl carbon. Represents two or more hydrocarbon groups.)   Furthermore, the primer composition in any one of Claims 1-7 containing the hydrolysis catalyst of the said ketimine compound.