JPH029605B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a two-component adhesive composition with good adhesive properties. So-called curable compositions are used in many fields, one of their major fields of application being adhesives.
Among the curable compositions currently industrially produced and used, specific examples of compositions that are easy to work with, are liquid at room temperature, and are useful as adhesives include epoxy adhesives, There are acrylic polymer adhesives, etc. However, many of these adhesives have a slow curing speed at room temperature, and have poor adhesive strength, especially peelability.
The splitting and impact strength are not sufficient, and there are problems such as the joint surface easily peeling off due to external force, and there is a need for improved workability and adhesive strength. The present invention has been completed through intensive research against the background as described above. The adhesive composition of the present invention consists of a first liquid consisting of the following components (A), (B), (C) and (D), and a second liquid consisting of the following component (E). configured. First, component (A) of the first liquid is a urethane prepolymer having a (meth)acryloyloxy group (acryloyloxy group and methacryloyloxy group are collectively referred to as such in this specification). This urethane prepolymer is a (meth)acrylic ester having a hydroxyl group (herein,
acrylic esters and methacrylic esters (hereinafter collectively referred to as methacrylic esters), organic polyisocyanates, trivalent or higher polyols, or polyols consisting of diols and trivalent or higher polyols (hereinafter simply referred to simply as polyols). A preferred urethane prepolymer is one obtained by reacting each raw material in a proportion sufficient to react with most of the isocyanate groups in the organic polyisocyanate to form a urethane or acid amide. . The suitable reaction ratio of each raw material is determined by
More specifically, the number of equivalents of the group -OH in NCO, a (meth)acrylic ester having a hydroxyl group, and the group -OH in a polyol is expressed as x, y, and z, respectively, as follows: x/(y+z)
is approximately 1. On the other hand, y/x needs to be 0.01 to 0.60, and the most preferable value is 0.1 to 0.5. As the reaction ratio of each raw material deviates from the above range, the adhesive strength exhibited by the adhesive composition according to the present invention decreases. Among the raw materials for producing urethane prepolymers having (meth)acryloyloxy groups, specific examples of (meth)acrylic acid esters having hydroxyl groups include (meth)acrylic acid hydroxyethyl ester, (meth)acrylic acid 3-hydroxypropyl ester , (meth)acrylic acid hydroxybutyl ester, (meth)acrylic acid hydroxyhexyl ester, (meth)acrylic acid hydroxyoctyl ester, and (meth)acrylic acid 2-hydroxy-3-chloropropyl ester. To give some specific examples of polyols that are other raw materials, diols include polyoxyethylene diol, polyoxypropylene diol, polyoxybutylene diol, polycaprolactone diol, hexane diol, and 1,4-butane diol. Examples of trivalent or higher polyols include trimethylolethane, trimethylolpropane, pentaerythritol, polyoxyethylene triol, polyoxypropylene triol, trishydroxyethyl isocyanurate, polyoxyethylene tetraol, polyoxypropylene tetraol, glycerin, and polyphosphorus. There are acids, etc. Specific examples of organic polyisocyanates that are other raw materials include toluene diisocyanate, 4,4'-diphenyl diisocyanate, 4,4'-diphenyl diisocyanate,
4'-diphenylmethane diisocyanate, dianidine diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diphenyl ether diisocyanate, p-phenylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, ethylene diisocyanate, Cyclohexylene diisocyanate, nonamethylene diisocyanate, octadecamethylene diisocyanate, 2-chloropropane diisocyanate, 2,
Low molecular weight organic polyisocyanates such as 2'-diethyl ether diisocyanate, tetrachlorophenylene diisocyanate, xylylene diisocyanate and 1,4,3-heptene diisocyanate; As if there were
Primary amines, secondary amines or polyhydric alcohols such as glycerol, polyoxyethylene triol, polyoxypropylene triol, polyoxyethylene tetraol, polyoxypropylene tetraol, polypropylene glycol, polyethylene glycol, polycaprolactone polyol, polytetra There are high molecular weight organic polyisocyanates obtained by reacting with polyhydric alcohols such as methylene ether glycol and ether type glycol obtained by adding ethylene oxide and/or propylene oxide to bisphenol A. Urethane polymers with (meth)acryloyloxy groups made from low molecular weight organic polyisocyanates have very high viscosity or are solid, so there are some difficulties when preparing and using adhesives using them. However, it is advantageous in that the setting time of the adhesive is extremely fast. On the other hand, urethane prepolymers with (meth)acryloyloxy groups made from high molecular weight organic polyisocyanates have appropriate viscosity, or even if they are wax-like at room temperature, they can easily become liquid with some heating. Alternatively, since it is highly soluble in component (B), which will be detailed later, it is easy to prepare and use the adhesive, and the adhesive properties are also satisfactory. Particularly suitable high molecular weight organic polyisocyanates in the present invention are those having a hydroxyl value.
It is obtained by reacting a 20-300% polyhydric alcohol with an excess amount of toluene diisocyanate, 4,4'-diphenylmethane diisocyanate or hexamethylene diisocyanate. Urethane prepolymers having (meth)acryloyloxy groups are produced by various methods. A particularly suitable manufacturing method in the present invention is a method containing a predetermined amount of organic polyisocyanate and a hydroxyl group (meth).
In this method, a (meth)acryloyloxy compound having an unreacted isocyanate group is produced by first reacting with an acrylic acid ester, and then this is reacted with a required amount of polyol. When using a high molecular weight organic polyisocyanate as a raw material in this method, a separately manufactured high molecular weight organic polyisocyanate can be used, or a low molecular weight organic polyisocyanate is first reacted with a polyhydric alcohol etc. in the urethane prepolymer synthesis system. It is also possible to form a high molecular weight organic polyisocyanate and use this as a raw material for subsequent reaction operations. The reaction temperature during urethane prepolymer production is 90℃
It is desirable that the temperature be below; if the temperature is too high, the reaction product will thicken due to gelation or allophanate formation. If the reaction temperature is too low, the viscosity of the reactants will increase and unreacted raw materials will be insufficiently dispersed and mixed, making it difficult to perform a smooth reaction. Therefore, the reaction should be carried out at around 50°C, more preferably around 70°C. preferable. The synthesis reaction of urethane prepolymer involves and consumes NCO groups at each step, and NCO groups exhibit strong absorption characteristics near 2250 cm ^-1 when analyzed by infrared absorption spectroscopy, so the reaction is difficult. The progress of the group in the reactant -NCO
It can be easily confirmed by conducting infrared absorption spectrum analysis of NCO and tracing its consumption from changes in the intensity of absorption characteristics, and the end point of each reaction step is when the consumption of NCO has stopped. do it. The urethane prepolymer having a (meth)acryloyloxy group in the present invention can be easily produced by the method described above. Next, component (B) of the first liquid constituting the composition of the present invention is (meth)acrylic acid (herein,
It is an acrylic compound selected from acrylic acid and methacrylic acid (hereinafter collectively referred to as methacrylic acid) and (meth)acrylic acid ester. In the present invention
There is a very wide range of (meth)acic acid esters that can be used as component (B). (Meth)acrylic acid esters can be used. Examples of (meth)acrylic acid esters used in the present invention are as follows, citing some of these patent publications as appropriate. [1] General formula or a reaction product of this monomer and an isocyanate compound. However, R ₁ represents hydrogen or -CH ₃ , and R ₂
is --CH ₂ --CH ₃ , --CH ₂ --CH ₂ --CH ₃ , or

[Formula] represents a compound in which hydrogen at an arbitrary position is eliminated to form a hand for bonding with an OH group, and n represents an integer of 1 to 3. Specific examples of the monomer of general formula [1] are as follows. 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 1,2-dihydroxyethyl (meth)acrylate, etc. [2] General formula monomer. However, R is hydrogen, -CH ₃ , -
C ₂ H ₅ , —CH ₂ OH, or

[Formula], R' represents hydrogen, chlorine, methyl, or ethyl group, R' represents hydrogen, -OH, or

[Formula], m represents an integer of 1 to 8, n represents an integer of 1 to 20, and p represents 0 or 1. Specifically, the monomer of the formula [2] includes, for example, diethylene glycol dimethacrylate, triethylene glycol diacrylate,
triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate,
1,2-propylene glycol dimethacrylate, dipropylene glycol dimethacrylate, polyethylene glycol dimethacrylate, di-(pentamethylene glycol) dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol di-
(chloro-acrylate), di-glycerol diacrylate, glycerin trimethacrylate, trimethylolpropane trimethacrylate, di-glycerol tetramethacrylate, etc. [3] General formula A monomer with However, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R' represents an alkylene group having 2 to 4 carbon atoms, and m represents an integer of 2 to 8. The monomers having the general formula [3] are specifically listed below. 2,2-bis(4-methacryloxydiethoxyphenyl)propane, 2,2-bis(4-methacryloxytriethoxyphenyl)propane, 2,2-bis(4-methacryloxytetraethoxyphenyl)propane , 2,2-bis(4-methacryloxypentaethoxyphenyl)
Propane, 2,2-bis(4-methacryloxyhexaethoxyphenyl)propane, 2,2-
Bis(4-methacryloxyheptaethoxyphenyl)propane, 2,2-bis(4-methacryloxyoctaethoxyphenyl)propane,
2,2-bis(4-methacryloxydipropoxyphenyl)propane, 2,2-bis(4-methacryloxytripropoxyphenyl)propane, 2,2-bis(4-methacryloxyoctapropoxyphenyl)propane , 2,2-bis(4-methacryloxydibutoxyphenyl)propane, 2,2-bis(4-methacryloxytributoxyphenyl)propane, 2,2-bis(4-methacryloxyocbutoxyphenyl)
Propane, 2,2-bis(4-acryloxydiethoxyphenyl)propane, 2,2-bis(4-acryloxydibutoxyphenyl)propane, 2-(4-methacryloxydiethoxyphenyl)-2 (4-methacryloxytriethoxyphenyl)propane, 2(4-methacryloxydipropoxyphenyl)-2(4methacryloxytriethoxyphenyl)propane, 2,2
-Bis(4-αethylacryloxydiethoxyphenyl)propane, 2,2-bis(αpropylacryloxydiethoxyphenyl)propane, 2(4-αethylacryloxydiethoxyphenyl)-2(4 - methacryloxydiethoxyphenyl)propane, etc. [4] General formula A monomer indicated by . However, R ₁ is H, CH ₃ or C ₂ H ₅ ,
R ₂ is -CH ₂ -, -C ₂ H ₄ -, -C ₃ H ₆ -, or

[Formula], where n is 0 and an integer from 1 to 10. The monomers having the general formula [4] are specifically listed below. In addition, in this specification, acrylate and methacrylate may be collectively referred to as (meth)acrylate. dicyclopentenyl (meth)acrylate,
Dicyclopentenyloxymethyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentenyloxypropyl (meth)acrylate, etc. [5] General formula A monomer indicated by . However, _R1 represents hydrogen or _CH3 , and _R2 represents a cycloalkyl group having 5 to 20 carbon atoms, a phenyl group, a tetrahydrofurfuryl group, or an alkyl group having 5 to 20 carbon atoms containing these groups. Specific examples of the monomer of formula [5] include cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, t-butylphenyl (meth)acrylate, and benzyl (meth)acrylate. [6] General formula A monomer indicated by . However, R ₁ represents hydrogen or CH ₃ , R ₂ is an alkylene group having 2 to 40 carbon atoms, and R ₃ is an alkylene group having 2 to 40 carbon atoms.
~40 alkyl group or the same group as _R2 . However, the sum of the carbon numbers of R ₂ and R ₃ groups does not exceed 40. Specific examples of the monomer of formula [6] include phenoxy-β-hydroxypropyl (meth)acrylate, cyclohexanoxy-
Examples include β-hydroxypropyl (meth)acrylate, tetrahydrofurfuroxy-β-hydroxypropyl (meth)acrylate, and nonyloxy-β-hydroxypropyl (meth)acrylate. [7] General formula A monomer indicated by . However, _R1 represents hydrogen or _CH3 , and _R2 represents an alkyl group, vinyl group, aryl group, or alkoxyalkyl group having 1 to 20 carbon atoms. Specific examples of the monomer of formula [7] include carbonylmethyl (meth)acrylate, heptoxycarbonylmethyl (meth)acrylate, and isopropoxycarbonylmethyl (meth)acrylate. Next, the component (C) in the first liquid in the present invention is a peroxyester that functions as a polymerization initiator for the components (A) and (B), and a specific example thereof is a tertiary ester. Butyl peroxybenzoate, tertiary butyl peroxy acetate, tertiary butyl peroxy isobutyrate, tertiary butyl peroxy pivalate, tertiary butyl diperoxy isophthalate, tertiary butyl peroxy neodecanoate,
Tertiary butyl peroxy 2-ethylhexanoate, Tertiary butyl peroxy 3,5,5
-trimethylhexanoate and tert-butyl peroxylaurate. Furthermore, the component (D) in the first liquid in the present invention is a polybasic acid and/or its anhydride,
This component (D) acts as a redox polymerization accelerator,
It is an effective component that makes it possible to shorten the set time from several seconds to several tens of seconds, and also to improve the adhesion between the adhesive and the adherend, especially the peel strength.
Specific examples of component (D) include maleic anhydride, maleic acid, itaconic anhydride, itaconic acid, fumaric anhydride, fumaric acid, tartaric acid, thiomalic acid, malic acid, citric anhydride, trans-aconitic acid, and pyromellitic acid. , pyromellitic anhydride, trimellitic anhydride, trimellitic anhydride, gallic anhydride, and borilic acid. (A) component, (B) component, (C) component in the first liquid and
The blending ratio of component (D) is as follows. In other words, component (A) and component (B) are based on the total amount of 100 parts by weight (hereinafter referred to as "parts"), and component (A) is 80 to 5 parts by weight.
parts, preferably 70 to 10 parts, and component (B) is 20 to 95 parts.
parts, preferably 30 to 90 parts. In addition, the (C) component and (D) component are 0.01 to 10 parts, preferably 1 to 7 parts, per 100 parts of the total amount of the (A) component and (B) component, and (D ) component is 0.01 to 20 parts, preferably 0.5 to 10 parts. The ratio of each component in the first liquid is a factor related to the viscosity of the first liquid, storage stability, adhesive strength when used as an adhesive, adhesion speed, etc., and the most appropriate blending ratio is Since the ratio varies depending on the type of each component, it is desirable to appropriately set the optimal ratio depending on the components used, and this can be easily done by a simple test. For the first liquid, in addition to the above four components, various polymers as thickeners, thixotropic agents, dyes, pigments, radical polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, catechol, phenothiazine, diphenylamine, di- t-Butylhydroxytoluene (abbreviation)
A small amount of additives such as ultraviolet absorbers, antioxidants, paraffin, and silane coupling agents may be added. The second liquid, which together with the first liquid constitutes the composition of the present invention, is composed of a compound (referred to as component (E)) that forms a redox system with component (C) in the first liquid, that is, peroxyester, which is a polymerization initiator. It is an accelerator.
As component (E), any compound that forms a redox system with this peroxyester can be used, and such compounds are already widely known, but in the present invention, among them,
Aldehyde-amine condensates are most suitable. Regarding aldehyde-amine condensates,
A detailed explanation is given in Publication No. 52-27176,
The condensate disclosed in the same patent can also be effectively used in the present invention. That is, a suitable aldehyde-amine condensate is preferably used in the presence of a carboxylic acid such as acetic acid, propionic acid, butyric acid, or valeric acid, or an inorganic acid such as phosphoric acid or sulfuric acid, preferably at least 1 mol per 1 mol of the amine.
It is obtained by reacting 1.0 to 3.5 mol, more preferably 1.5 to 3.0 mol, of an aldehyde at a temperature of preferably 175°C or lower, more preferably 40 to 100°C. As the aldehyde, aromatic aldehydes such as benzaldehyde and naphthylaldehyde can be used, but aliphatic aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, heptaldehyde, hexaaldehyde, crotonaldehyde, cinnamaldehyde, hydrocinnamaldehyde, 2-phenylpropionaldehyde and the like are more suitable. On the other hand, as an amine,
Primary or secondary aliphatic or aromatic amines are used. More specifically, the primary aliphatic amines include ethylamine, n-propylamine, n-propylamine, i-propylamine,
n-hexylamine, t-butylamine, etc.
Secondary aliphatic amines include diethylamine, dipropylamine, di-i-propylamine, etc., and primary aromatic amines include aniline, p-toluidine, 0-naphthylamine, p-naphthylamine, xylidene, benzylamine, p- -benzylaniline, etc., and secondary aromatic amines such as diphenylamine, N-phenylbenzylamine, and N-allylaniline. Specific examples of useful condensates made from these aldehydes and amines include formaldehyde-p-benzylaniline condensate, acetaldehyde-benzylamine condensate, crotonaldehyde-butylamine condensate, cinnamaldehyde-aniline condensate, Skin aldehyde-butylamine condensate, 2-phenylpropionaldehyde-butylamine condensate, butyraldehyde-butylamine condensate, butyraldehyde-aniline condensate, hydrocinnamaldehyde-butylamine condensate, naphthaldehyde
0-Toluidine condensate, heptaldehyde-N-
Allylaniline condensates, etc. Component (E) is better in terms of workability as a promoter if it is dissolved or dispersed in a liquid medium, preferably a solvent with a high evaporation rate, to form the second liquid. Suitable solvents include halogenated hydrocarbon solvents such as methylene chloride, trichloroethane, methylchloroform, trichloroethylene, trichloromonofluoromethane, ketone or ester solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and ethyl acetate. , aromatic hydrocarbon solvents such as xylene, benzene, and toluene. The concentration of component (E) in the second liquid can be 100% by weight (hereinafter referred to as %), but a lower concentration is suitable considering economic efficiency, etc. On the other hand, if the concentration is too low, it will not be applied to the surface of the adherend. When this happens, it becomes difficult to uniformly distribute component (E), which may lead to a decrease in adhesive strength, so a concentration of 0.1 to 30% is preferable. In the two-component adhesive composition according to the present invention,
By simply bringing the first liquid into contact with component (E), which is a curing accelerator in the second liquid, the polymerization and curing reaction of the first liquid starts immediately and progresses quickly, achieving appropriate adhesive strength in a short period of time. Therefore, the first liquid is applied to one adherend, the second liquid is applied as a so-called primer to the other adherend, and if the second liquid contains a solvent, it is volatilized. It is most desirable to use this method in a method of bonding together the coated surfaces of each adherend after the adhesive has been applied. There are no particular restrictions on the ratio of the amount of the first liquid to the second liquid applied to the adherend.
If the applied amount of component (E) in the second liquid is approximately 10% or around this amount relative to the applied amount of the first liquid,
The adhesive composition of the present invention exhibits excellent adhesive strength in a short period of time. Next, the present invention will be explained in further detail with reference to Reference Examples and Examples. Reference example Toluene diisocyanate (hereinafter TDI) is used in the reactor.
), and while maintaining the reaction temperature at 70°C, gradually added about 88 parts (z = 0.044) of polycaprolactone polyol having a molecular weight of about 4000 with stirring, and stirred for about 1 hour. After the reaction, about 3 parts of methacrylic acid 2-hydroxyethyl ester (y = 0.023, y/x = 0.25) was gradually added under stirring and while maintaining the reaction temperature at 70°C.
After stirring and reacting for about 2 hours, about 1 part of trimethylolpropane [z=0.022, x/(y+z)=
Add 1.03, maintain the reaction temperature at 70℃, and analyze the reaction solution using an infrared absorption spectrum, and continue the reaction until it is confirmed that the characteristic absorption of the isocyanate group (around 2250 cm ^-1 ) disappears. did. As a result, a urethane prepolymer was obtained as a waxy solid at room temperature. Furthermore, as a result of analyzing the urethane prepolymer using an infrared absorption spectrum (hereinafter referred to as IR), the following main peaks were confirmed. Absorption of -NHCOO-; 1520 to 1550 cm ^-1 , 1720 to 1740 cm ^-1 CH ₂ =C-COO- Absorption; 930 to 960 cm ^-1 Reference example Approximately 13 parts of TDI (x = 0.149) was placed in a reactor and the reaction was started. While maintaining the temperature at 70°C, about 77 parts of polyoxypropylene triol with a molecular weight of about 3000 (z =
0.077) was gradually added under stirring, and after stirring and reacting for about 1 hour, about 9 parts of methacrylic acid 2-hydroxyethyl ester (y = 0.069, y/x = 0.46)
was gradually added under stirring and while maintaining the reaction temperature at 70°C, stirred and reacted for about 2 hours, and then added about 0.4 parts of trimethylolpropane [z = 0.009, x/
(y + z) = 0.96], the reaction temperature was maintained at 70°C, and the reaction solution was analyzed by IR, and the reaction was continued until it was confirmed that the characteristic absorption of the isocyanate group (around 2250 cm ^-1 ) disappeared. continued. As a result, the urethane prepolymer 99.4 has a viscosity of approximately 50,000 cps at 70°C.
I got the department. As a result of performing IR analysis of this urethane prepolymer, main peaks similar to those of the reference example were confirmed. Reference example: Put approximately 14 parts of TDI (x = 0.161) in a reactor, maintain the reaction temperature at 70°C, and add approximately 79 parts of polycaprolactone polyol (z = 0.079) with a molecular weight of approximately 2000.
was gradually added under stirring and reacted with stirring for about 1 hour, and then about 5 parts of methacrylic acid 2-hydroxyethyl ester (y=0.038, y/x=0.24) was added under stirring and the reaction temperature was increased to 70°C. After gradually adding the mixture while maintaining the temperature at
z) = 0.99], the reaction temperature was maintained at 70°C, and the reaction was continued until the reaction solution was analyzed by IR and it was confirmed that the characteristic absorption of isocyanate groups (around 2250 cm ^-1 ) disappeared. continued. As a result, the urethane prepolymer forms a waxy solid at room temperature.
Got 100 copies. As a result of IR analysis of the urethane prepolymer, the same main peak as in the reference example was confirmed. Reference example Approximately 24 parts of TDI (z = 0.276) was placed in a reactor, and while maintaining the reaction temperature at 70°C, approximately 47 parts of polytetramethylene ether glycol (z =
0.085) and about 16 parts of polyoxypropylene glycol (z = 0.032) with a molecular weight of 1000 was gradually added under stirring, and after stirring and reacting for about 1 hour,
Methacrylic acid 2-hydroxyethyl ester approx. 10
(y = 0.077, y / =0.067, x/(y+z)=
1.06], the reaction temperature was maintained at 70°C, and the reaction solution was analyzed by IR, and the reaction was continued until it was confirmed that the characteristic absorption of the isocyanate group (around 2250 cm ^-1 ) disappeared. . As a result, about 100 parts of a urethane prepolymer having a viscosity of about 80,000 cps at 70°C was obtained. As a result of IR analysis of the urethane prepolymer, the same main peak as in the reference example was confirmed. Reference example: Approximately 13.8 parts of TDI (x = 0.158) was placed in a reactor, and while maintaining the reaction temperature at 70°C, approximately 79.3 parts of polyoxypropylene glycol with a molecular weight of 2000 (z =
0.079) Gradually add while stirring, stir for about 1 hour and react, then add about 5.2 parts of methacrylic acid 2-hydroxyethyl ester (y = 0.040, y/x = 0.25) under stirring and at a reaction temperature of 70°C. while maintaining
After gradually adding and reacting with stirring for about 1 hour, add about 1.8 parts of trimethylolpropane [z=0.040, x/
(y + z) = 0.99], the reaction temperature was maintained at 70°C, and the reaction solution was analyzed by IR until it was confirmed that the characteristic absorption of the isocyanate group (around 2250 cm ^-1 ) disappeared. The reaction continued. As a result, the urethane prepolymer has a viscosity of approximately 10,000 cps at 70°C.
Got 100 copies. As a result of IR analysis of the urethane prepolymer, the same main peak as in the reference example was confirmed. Examples and Comparative Examples Using the urethane prepolymers having methacryloyloxy groups obtained in Comparative Examples ~, a first liquid having the composition shown in Table 1 was prepared. Further, a second liquid was prepared by dissolving 80 parts of a butyraldehyde-aniline condensate (trade name "Notsu Cellar 8", manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.) in 20 parts of methyl chloroform.

[Table] *1: 2-Hydroxyethyl methacrylate *2: Tertiary butyl peroxybenzoate Using carbon steel adherends, apply the above first liquid to one adherend, and apply the above second liquid to one adherend. After applying the solution to the other adherend and allowing it to air dry, the coated surfaces of each adherend were overlapped and the tensile shear strength was determined according to JIS K-6850, and the impact strength was determined according to JIS K-6855. ,Also
T-shaped peel strength was measured according to JIS K-6854. Regarding the set time, please refer to JIS K- for adhesion.
6849, the time required until it could not be removed by pulling it by hand at room temperature was measured, and that time was taken as the set time. The results were as shown in Table 2.

【table】

Claims (1)

[Claims] 1 (A) Organic polyisocyanate, a (meth)acrylic ester having a hydroxyl group, and a trivalent or higher polyol, or a polyol consisting of a diol and a trivalent or higher polyol, the equivalent of the NCO group that the organic polyisocyanate has is x, and the hydroxyl group is The ratio x/(y+
z) is about 1 and the ratio y/x is 0.01 to 0.60, the reaction product is a urethane prepolymer having (meth)acryloyloxy groups,
(B) one or more acrylic compounds selected from (meth)acrylic acid and its esters, (C) a polymerization initiator selected from peroxy esters, and (D) a polybasic acid and/or its anhydride, Based on 100 parts by weight of the total amount of components (A) and (B), component (A) is 80 to 5 parts by weight, component (B) is 20 to 95 parts by weight, and component (A) is Component (C) is 0.01 to 10 parts by weight and component (D) is 0.01 to 10 parts by weight based on the total amount of component (B) (100 parts by weight).
A two-part acrylic adhesive composition, wherein the first part is 20 parts by weight of the composition, and the second part is (E) an accelerator comprising a compound forming a redox system with the polymerization initiator (C).