JP2003055635A - Primer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a primer composition which is excellent in the balance between the storage stability and the adhesiveness and allows a longer open time. SOLUTION: The primer composition is characterized in that it contains (a) one or more polyisocyanate compounds, (b) compound(s) represented by formula (1) and/or formula (2), and (c) an organic solvent.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a primer composition, and more particularly to a primer composition capable of maintaining good adhesion to an adherend for a long period of time after application even under high temperature and high humidity.

[0002]

2. Description of the Related Art To bond an automobile body to a windshield or the like, high bond strength and bond durability are required under various conditions such as low temperature, high temperature and high humidity. Typically,
Urethane-based sealants have been used for such applications, but may not meet desired safety or structural goals. Therefore, when bonding the windshield and rear window in most car body assembly work,
The primer is applied before applying the sealant. As such a primer, conventionally, a film-forming component such as polyester polyurethane or acrylic resin,
Some include silane coupling agents, polyisocyanate compounds, carbon black and the like. However, conventional primer compositions use free isocyanate groups in the polyisocyanate compound as the adhesive component, so if a long time is applied before the sealant is applied, the adhesiveness is likely to be lost due to the humidity in the air, and the composition will open. The workability was poor because the time could not be taken long. Further, when trying to take a long open time, it is necessary to use one having a low activity of an isocyanate group, so that the balance with the adhesiveness tends to be poor, and there has never been a primer composition which can satisfy these at the same time. It was Here, the open time means a period from the time when the primer is applied to the adherend to the time when the sealant is applied.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a primer composition which has an excellent balance of storage stability and adhesiveness and which can have a long open time.

[0004]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors, a primer composition containing one or more polyisocyanate compounds and a specific oxazolidine ring-containing compound has improved storage stability and adhesiveness. The present invention has been completed based on the finding that the balance is excellent and the adhesiveness can be maintained for a long period of time after application even under high temperature and high humidity.

That is, the present invention comprises (a) one or more polyisocyanate compounds, and (b) the following general formula (1):
And / or a compound represented by (2) and (c) an organic solvent are provided.

[Chemical 3] (In the formula, m and m ′ are integers of 1 to 6, n and n ′ are integers of 0 to 5, R ¹ and R ⁴ are aliphatic or aromatic hydrocarbon groups having 3 or more carbon atoms, R ² , R ⁵ is a hydrogen atom or an aliphatic or aromatic hydrocarbon group having 3 or more carbon atoms, R ³ , R ⁶
Is a residue obtained by removing an isocyanate group from a polyisocyanate compound, and R ⁷ is an aliphatic hydrocarbon group having 1 to 6 carbon atoms. )

The compound (b) is preferably a reaction product of an oxazolidine compound having active hydrogen and an aliphatic polyisocyanate compound having a secondary isocyanate group and / or a tertiary isocyanate group. The polyisocyanate compound (a) preferably contains at least a compound represented by the following formula (3).

[Chemical 4]

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The primer composition of the present invention will be described in detail below. The primer composition of the present invention comprises (a) one or more polyisocyanate compounds,
It is characterized by containing (b) the compound represented by the general formula (1) and / or (2) and (c) an organic solvent.

The polyisocyanate compound as the component (a) is a compound having two or more isocyanate groups in the molecule and is not particularly limited as long as it is a compound other than the component (b) described later. As the polyisocyanate compound, either an aromatic or an aliphatic polyisocyanate compound can be used. Here, the aromatic polyisocyanate compound means an isocyanate compound in which all the isocyanate groups are directly bonded to the aromatic ring, and the aliphatic polyisocyanate compound means a polyisocyanate compound other than the aromatic polyisocyanate compound. Examples of the aromatic polyisocyanate compound include 2,4
-Or 2,6-tolylene diisocyanate (TD
I), 1,4-phenylene diisocyanate, 4,4 '
-Or 2,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate, tolidine diisocyanate, triphenylmethane triisocyanate, polymethylene polyphenyl isocyanate, a compound represented by the following formula (3), and the like.

[Chemical 5]

Examples of the aliphatic polyisocyanate compound include ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), xylylene diisocyanate and tetramethyl xylylene diisocyanate (T).
MXDI), 1,6,11-undecane triisocyanate, 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate, trimethylhexamethylene diisocyanate, a hydrogenated compound of each aromatic polyisocyanate compound described above, or a compound thereof. Examples thereof include an isocyanurate body of a low molecular weight polyvalent isocyanate compound, a burette body, and an adduct with a polyhydric alcohol.

Preferred isocyanurates of low molecular weight polyisocyanate compounds include isocyanurates such as IPDI and TMXDI, and isocyanurates of TDI and HDI. As an adduct of a low molecular weight polyhydric isocyanate compound and a polyhydric alcohol, trimethylolpropane (TM) is used as the polyhydric alcohol.
An adduct using P) is preferred. Specifically, a TMXDI / TMP adduct (formula (4)) derived from 1,1,1-trimethylolpropane (TMP) and TMXDI is preferable.

[0011]

[Chemical 6]

The above-mentioned adduct is, for example, a seisen 3
A commercially available product such as 160 (Mitsui Cytec Co., Ltd.) can also be used. Such an adduct does not necessarily have to be a complete OH: NCO adduct and may contain unreacted raw materials.

The primer composition of the present invention is used by appropriately selecting one or more of these polyisocyanate compounds. Among these polyisocyanate compounds, the isocyanurate body of a low molecular weight polyvalent isocyanate compound and the compound represented by the above formula (3) are preferable because the balance between the adhesiveness and the storage stability of the primer composition is particularly excellent. used.

In particular, in order to have good adhesion to various adherends, it is preferable that at least the compound represented by the above formula (3) is contained as the component (a). The content of the compound represented by the above formula (3) in the component (a) is preferably 0.5 to 60% by weight, more preferably 1 to 45% by weight, particularly preferably 1.5 to 35% by weight. % By weight. Within this range, the balance between storage stability and adhesiveness is particularly excellent. The total content of the (a) polyisocyanate compound in the primer composition of the present invention is preferably 5 to 75% by weight, more preferably 5 to 60% by weight, particularly preferably 5 to 40% by weight. Is. Within this range, the balance between storage stability and adhesiveness is particularly excellent.

Next, the component (b) of the present invention will be described. The component (b) of the present invention is a compound represented by the following general formula (1) and / or (2).

[Chemical 7]

In the general formulas (1) and (2), m and m '
Is preferably 1, 2, 3, 4, 5, 6, particularly 1 to 3 from the viewpoint of storage stability. n, n ′ are 0, 1, 2,
It is preferably 3, 4, 5, especially 0 to 3, from the viewpoint of adhesiveness and storage stability. R ¹ and R ⁴ have 3 carbon atoms
As described above, it is preferably an aliphatic or aromatic hydrocarbon group having 3 to 18 carbon atoms. For example, as an aliphatic group, n
-Propyl, isopropyl, n-butyl, isobutyl,
2,3-dimethylbutyl, s-butyl, t-butyl, 1
-Methylbutyl, n-pentyl, 2-methylpentyl,
3-methylpentyl, 3,5,5-trimethylpentyl, n-heptyl, n-octyl, n-nonyl, n-decanyl, n-undecanyl, n-dodecanyl, n-tridecanyl, n-tetradecanyl and the like can be mentioned. Examples of the aromatic group include phenyl, naphthyl, alkoxyphenyl and the like, which may have a substituent such as alkyl and alkoxyl. Of these, R ¹ and R ⁴ are isopropyl, 1-methylbutyl, phenyl, p-
Methoxyphenyl and the like are preferable. R ² and R ⁵ are hydrogen atoms or 3 or more carbon atoms, preferably 3 to 1 carbon atoms
8 aliphatic or aromatic hydrocarbon groups, for example R
^The groups exemplified as R ¹ and R ⁴ can be mentioned. Among them, hydrogen atom, isopropyl, 1-methylbutyl, phenyl, p-
Methoxyphenyl is preferred.

R ³ and R ⁶ are residues obtained by removing an isocyanate group from a polyisocyanate compound and may be either aliphatic or aromatic. R ³ and R ⁶ are not particularly limited as long as they are residues obtained by removing the isocyanate group from the polyisocyanate compound exemplified as the component (a). Examples thereof include aromatic groups such as tolylene, diphenylmethane, phenylene and polymethylene polyphenylene, aliphatic groups such as hexamethylene, xylylene, tetramethylxylylene and isophorone, and isocyanurate-modifying groups thereof. Above all,
From the viewpoint of storage stability, an aliphatic group having a secondary or tertiary isocyanate group is preferable, and specific examples thereof include tetramethylxylylene and an isocyanurate-modifying group of isophorone. R ⁷ has 1 to 6 carbon atoms
Is an aliphatic hydrocarbon group. For example, in addition to methyl and ethyl, the groups exemplified for R ¹ and R ² and the like can be mentioned. Of these, methyl, ethyl, isopropyl, n-butyl, isobutyl, t-butyl and the like are preferable.

The compound of component (b) is preferably a reaction product of an oxazolidine compound having active hydrogen and an aliphatic polyisocyanate compound having a secondary isocyanate group and / or a tertiary isocyanate group. The oxazolidine compound having active hydrogen is not particularly limited, and examples thereof include compounds represented by the following general formula (5) or (6).

[Chemical 8] R ¹ , R ² , R ⁴ in the general formulas (5) and (6),
R ⁵ and R ⁷ have the same meanings as in formulas (1) and (2).

As the compound represented by the general formula (5),
For example, the following compounds are preferred.

[Chemical 9]

As the compound represented by the general formula (6),
For example, the following compounds are preferred.

[Chemical 10] These compounds are synthesized by a known method from the corresponding aldehyde or ketone and hydroxyalkylamine.

The aliphatic polyisocyanate compound having a secondary isocyanate group and / or a tertiary isocyanate group has a secondary isocyanate group and / or a tertiary isocyanate group among the polyisocyanate compounds of the above component (a). Aliphatic polyisocyanate compounds can be used. By using an aliphatic polyisocyanate compound having such a structure,
The storage stability of the primer composition is particularly excellent. Specifically, IPDI, TMXDI, bicycloheptane triisocyanate, hydrogenated compounds of the above-mentioned aromatic polyisocyanate compounds, isocyanurates of IPDI, TM
Examples include XDI / TMP adducts.

The reaction ratio of the oxazolidine compound having active hydrogen and the aliphatic polyisocyanate compound having a secondary isocyanate group and / or a tertiary isocyanate group is such that the active hydrogen (eg, OH) contained in the oxazolidine compound is The equivalent ratio (for example, NCO / OH) of the isocyanate group (NCO) contained in the polyisocyanate compound is preferably 6/1 to 1/1, more preferably 4/1 to 1/1.

The method of synthesizing the compound of component (b) is not particularly limited. For example, it can be obtained by mixing the aliphatic polyisocyanate compound with an oxazolidine compound having active hydrogen and then reacting the mixture at room temperature to 50 ° C. for 4 to 24 hours. To be
As the reaction solvent, the organic solvent described below can also be used. For example, ethyl acetate, butyl acetate and the like can be preferably used. The compound of component (b) thus synthesized does not need to be isolated and can be used in a state containing a reaction solvent. The compounds of component (b) may be used alone or in combination of two or more. The content of the component (b) in the primer composition of the present invention is
It is preferably 0.05 to 20% by weight, more preferably 0.1 to 15% by weight, particularly preferably 0.1 to 10% by weight.
% By weight. Within this range, the balance between storage stability and adhesiveness is particularly excellent.

The organic solvent contained in the primer composition of the present invention is not particularly limited as long as it is inert to the above component (a) or component (b) and has appropriate volatility. . Specifically, methyl ethyl ketone,
Ethyl acetate, butyl acetate, cellosolve acetate, mineral spirits, toluene, xylene, dimethylacetamide, acetone, n-hexane, methylene chloride,
Tetrahydrofuran, ethyl ether, dioxane and the like can be mentioned. Among these organic solvents, methyl ethyl ketone and ethyl acetate are preferable. These organic solvents may be used alone or in combination of two or more. The organic solvent is preferably dried or dehydrated before use. The content of the organic solvent in the primer composition of the present invention is preferably 5% by weight or more. The content of the organic solvent varies depending on the application,
The solid content concentration of the primer composition is preferably 20 to 5
It is preferable to add so as to adjust to 0% by weight, more preferably 20 to 35% by weight.

The primer composition of the present invention may contain a film-forming resin, if necessary. The film-forming resin is not particularly limited as long as it is a resin that is inactive with respect to isocyanate groups and has film-forming properties, and known resins can be used. For example, acrylic resin, polyester-based polyurethane resin, chlorinated rubber, terpene resin and the like are preferably used. The content of the film-forming resin in the primer composition is preferably 1 to 20% by weight, more preferably 1 to 15% by weight, and particularly preferably 1 to 10% by weight.

The primer composition of the present invention may contain carbon black, if necessary.
Since carbon black shields or absorbs ultraviolet rays and visible rays, weather resistance can be imparted by containing carbon black. The carbon black used in the present invention is not particularly limited, and N1 in the American Society for Testing and Materials standards
10, N220, N330, N550, N770, etc., or a mixture thereof can be used. From the viewpoint of dispersibility, the content of carbon black in the primer composition is preferably 5 to 40% by weight, more preferably 10 to 30% by weight, particularly preferably 10 to 25% by weight.
Is.

Further, other additives may be contained, if desired. For example, inorganic pigments such as lamp black, titanium white, red iron oxide, titanium yellow, zinc white, red lead, cobalt blue, iron black and aluminum powder; neo-zabon black RE, neo black RE, orazole black CN, orazole black Ba (Both are Ciba
Organic pigments such as Geigy Co., Ltd., Spiron Blue 2BH (Hodogaya Chemical Co., Ltd.); Cyasorb UV24Ligh
t Absorber, manufactured by American Cyanamid, Ubinul (Uvinul D-49, D-50, N-35, N-539, General
When an ultraviolet absorber such as (produced by Aniline Co., Ltd.) is contained, it shields or absorbs ultraviolet rays and visible rays and is effective in improving light resistance. Furthermore, fillers such as glass powder, clay, powdered silica gel, ultrafine pulverized silicic acid, molecular sieves (which also have a water-absorbing ability), thickeners, butylbenzyl phthalate, dioctyl phthalate, dibutyl phthalate, chlorinated paraffin, etc. It may contain a plasticizer.

The method for producing the primer composition of the present invention is not particularly limited. For example, the above-mentioned component (a), component (b),
If necessary, carbon black and other additives may be dissolved in an organic solvent, sufficiently kneaded using a mixing device such as a ball mill, and uniformly dispersed.

The primer composition of the present invention thus obtained has an excellent balance between storage stability and adhesiveness. Further, after application, good adhesiveness to an adherend can be maintained for a long period of time even under high temperature and high humidity. The adhesive strength is maintained in a high state even under the conditions of hot water, chemicals and the like. Therefore, the primer composition of the present invention,
The open time can be long and there is no need to re-apply even if it takes a long time to apply the sealant, so it has excellent workability.

The reason why the primer composition of the present invention can maintain good adhesiveness to an adherend for a long period of time even under high temperature and high humidity is not clear. Even if the isocyanate group of is deactivated by moisture, the functional groups having active hydrogen generated by hydrolysis of the oxazolidine ring remain on the surface of the composition, and these can bond with adhesives and sealants having free isocyanate groups. I think this is because of this. The primer composition of the present invention, when exposed to atmospheric humidity, opens the oxazolidine ring to generate active hydrogen, so that there are many active sites for the urethane-based sealant applied thereon. It becomes a state. Therefore, it is considered that the open time can be extended.

[0031]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. First, an oxazolidine compound having active hydrogen and a polyisocyanate compound having a secondary isocyanate group and / or a tertiary isocyanate group were reacted at the composition ratios shown in Table 1 to synthesize compounds b-1 to b-9. As the synthetic method, an oxazolidine compound having active hydrogen was added to a 50% by weight ethyl acetate solution of polyisocyanate, and the reaction was carried out at room temperature to 50 ° C. for 8 to 16 hours. Then, ethyl acetate was added to the reaction solution to adjust the solid content concentration to 50% by weight.

[0032]

[Table 1]

<Ingredients in Table 1> IPDI isocyanurate Isophorone diisocyanate isocyanurate "T1890-100" manufactured by Degussa Huls TMXDI Tetramethyl xylylene diisocyanate TMXDI / TMP adduct Compound represented by formula (4) Oxazolidine (3) 2-phenyl-3-oxazolidine ethanol Oxazolidine (2) 2-pentyl-3-oxazolidineethanol

(Examples 1 to 11) Compounds b-1 to b-
9, a polyisocyanate compound, a polyester-based polyurethane resin, carbon black and ethyl acetate were used in the composition ratios shown in Table 2 and mixed until uniform in a ball mill to obtain a composition. The storage stability and adhesiveness of the obtained composition were evaluated as follows. The results are summarized in Table 2.

<Storage Stability Test> The obtained composition was stored in a closed container at 60 ° C., and the state after 7 days was observed. The case where gelation or solidification did not occur was marked as ○,
The case where gelation or solidification occurred was designated as x.

<Adhesion Test> The composition thus obtained was applied to the surface of an acrylic-coated iron plate and exposed under conditions of 20 ° C. and 55% relative humidity (RH) for 5 minutes, or
After being exposed to the conditions of 40 ° C. and 95% relative humidity for 21 days, a polyurethane sealant (“WS95” manufactured by Yokohama Rubber Co., Ltd.) was pressure-bonded to the coated surface of the composition to a thickness of 3 mm to obtain a test piece. The following peel test was performed using this test piece, and the state of the adhesive interface between the adherend and the composition was observed. In Table 2,
CF indicates that the sealant has undergone cohesive failure, and PS indicates that the sealant-primer interface has failed.
The numerical value indicates the ratio (%) of the destroyed area to the applied area. For example, CF100 indicates that the composition undergoes cohesive failure over the entire coating area and there is no peeling at the interface between the composition and the surface of the adherend. (1) The initial adhesion test piece was left for 72 hours under the conditions of 20 ° C. and relative humidity of 65%, and then a peeling test by knife cutting was performed. (2) The hot water-resistant adhesive test piece was left for 72 hours under the conditions of 20 ° C. and 65% relative humidity, then immersed in warm water of 40 ° C. for 168 hours, and then subjected to a peeling test in the same manner as in (1) above. . (3) The heat-resistant adhesive test piece was allowed to stand for 72 hours under the conditions of 20 ° C. and 65% relative humidity, and then a peeling test was performed in the same manner as in (1) above. (4) After the window washer solution adhesive test piece was left for 72 hours under the conditions of 20 ° C. and 65% relative humidity, it was immersed in a 50 wt% dilution solution of the window washer solution at 20 ° C. for 168 hours, and then the above ( A peeling test was performed in the same manner as 1).

Comparative Example 1 In the same manner as in Examples 1 to 11, compositions were prepared with the composition ratios shown in Table 2 and the storage stability and adhesiveness were evaluated. The results are summarized in Table 2.

[0038]

[Table 2]

<Ingredients in Table 2> Polyisocyanate 1 An ethyl acetate solution of the compound represented by the above formula (3) (solid content concentration: 27% by weight), "Desmodur RFE" polyisocyanate 2 TDI manufactured by Sumitomo Bayer Urethane Co., Ltd. Butyl acetate solution of isocyanurate with HDI (solid content concentration 60% by weight), "Desmodur HL" manufactured by Sumitomo Bayer Urethane Co., Ltd. Polyester polyurethane resin "Pandex T-520 manufactured by Dainippon Ink and Chemicals, Inc."
5 "Carbon Black Asahi Thermal" Asahi Thermal "ethyl acetate

[0040]

EFFECTS OF THE INVENTION The primer composition of the present invention has an excellent balance of storage stability and adhesiveness, and can maintain good adhesiveness to an adherend for a long period of time after application even under high temperature and high humidity. You can have a long open time.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hideyuki Matsuda             2-1, Oiwake, Hiratsuka-shi, Kanagawa Yokohama Rubber Co., Ltd.             Ceremony Company Hiratsuka Factory F term (reference) 4J034 HA02 HA08 HB03 HB07 HB15                       HC32 JA42 MA11 MA21 QA01                       QA03 QC05 RA08                 4J040 DF032 DN072 EF002 EF161                       EF291 EF301 EF311 EF321                       HB02 HB03 HB18 HB31 HB43                       HC16 HC26 JA02 JB02 KA16                       KA23 LA05 LA06 NA15 PA03                       PA30

Claims (3)

[Claims] 1. (a) One or more kinds of polyisocyanate compounds, and (b) the following general formulas (1) and / or (2).
A primer composition comprising the compound represented by: and (c) an organic solvent. [Chemical 1] (In the formula, m and m ′ are integers of 1 to 6, n and n ′ are integers of 0 to 5, R ¹ and R ⁴ are aliphatic or aromatic hydrocarbon groups having 3 or more carbon atoms, R ² , R ⁵ is a hydrogen atom or an aliphatic or aromatic hydrocarbon group having 3 or more carbon atoms, R ³ , R ⁶
Is a residue obtained by removing an isocyanate group from a polyisocyanate compound, and R ⁷ is an aliphatic hydrocarbon group having 1 to 6 carbon atoms. ) 2. The compound according to claim 1, wherein the compound (b) is a reaction product of an oxazolidine compound having active hydrogen and an aliphatic polyisocyanate compound having a secondary isocyanate group and / or a tertiary isocyanate group. The described primer composition. 3. The polyisocyanate compound (a) contains at least a compound represented by the following formula (3):
The primer composition according to claim 1 or 2. [Chemical 2]