JPS60199085A - Acrylic adhesive composition - Google Patents

Abstract

PURPOSE:An adhesive composition consisting of the first solution consisting of a specific urethane prepolymer, acrylic compound and polymerization initiator and the second solution consisting of a polymerization initiator and redox-system forming compound. CONSTITUTION:A two-pack type acrylic adhesive composition consisting of a composition consisting of (A) a urethane prepolymer which has (meth)acryloyloxy groups and is a reaction product of an acrylic or methacrylic acid ester having hydroxyl group with an organic polyisocyanate and polybasic acid (anhydride), (B) an acrylic or methacrylic acid (ester) and (C) a peroxy ester as the first solution and an accelerator consisting of (D) the polymerization initiator same as the component (C) and (E) a redox system-forming compound as the second solution.

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, it is easy to work with and is liquid at room temperature.

Specific examples of compositions that are also useful as adhesives include:

There are epoxy adhesives, 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 has the following (A) and (B).

It is composed of a first liquid consisting of the component (C) and a second liquid consisting of the following component (D).

First, component (A) of the first liquid is a urethane prepolymer having a (meth)acryloyloxy group (herein, acryloyloxy group and methacryloyloxy group are collectively referred to as such). Urethane prepolymers are composed of (meth)acrylic esters having hydroxyl groups (in this specification, acrylic esters and methacrylic esters are collectively referred to as such), organic polyisocyanates, and polybasic acids or their acid anhydrides. A preferred urethane prepolymer is one obtained by reacting each raw material in a proportion sufficient to cause most of the isocyanate groups in the organic polyisocyanate to react to form a urethane or an acid amide. The preferred reaction ratio of each raw material is the group -OH in the (meth)acrylic acid ester having a water dispersion group, the group -NCO in the organic polyisocyanate, and the group -CO in the polybasic acid.
More specifically, by OH.

and most preferably (-NCO)/(-0H) = 1.1 to 1.4 xen-COO
H)/((-NCO)-(-OH))=2-4. In this roof tile, n indicates the number of groups -COOHO in the polybasic acid,
When a polybasic acid anhydride is used instead of a polybasic acid, the adhesive strength exhibited by the adhesive composition according to the present invention decreases as the reaction ratio of each raw material in the polybasic acid anhydride deviates from the above range. .

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.

Examples include (meth)acrylic acid hydroxyoctyl ester and (meth)acrylic acid 2-hydroxy-3=chloropropyl ester.

Specific examples of polybasic acids or their anhydrides that are other raw materials include maleic anhydride, maleic acid, itaconic anhydride,
Itaconic acid, tartaric acid, thiomalic acid, malic acid, phthalic anhydride, heptalic acid, cudonoenic anhydride% transaconitic acid, pyromellitic acid, pyromellitic anhydride, trimellitic acid, trimellitic anhydride, gallic anhydride, and Examples include polyphosphoric acid.

Specific examples of organic polyisocyanates that are other raw materials include toluene diisocyanate), 4.4ξ diphenyl diisocyanate, 4゜4'-diphenylmethane diisocyanate, dianisidine 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,
Low molecular weight organic polyisocyanates such as octadecamethylene diisocyanate, 2-chloropropane diisocyanate, 2°2-diethyl ether diisocyanate, tetrachlorophenylene diisocyanate and 1,4,3-heptene diisocyanate; primary amines, secondary grade amines or polyhydric alcohols such as glycerol, polyoxyethylenetriol, polyoxyethylenenatho2ol, 1,2,6-hexanetriol,
Polypropylene glycol, 1,5-bentanediol, ethylene glycol.

Polyhydric flucols such as polyethylene glycol, substituted or unsubstituted bisphenol A,
As already known, there is a φ high molecular weight organic polyisocyanate obtained by reacting with an excess amount of the above-mentioned low molecular weight organic polyisocyanate. Urethane prepolymers with (meth)acryloyloxy groups made from low molecular weight organic polyisocyanates have very high viscosity or are solid, so adhesives using them have a +1111
! Although there are some difficulties when using it, it has the advantage of exhibiting an extremely fast adhesive setting time.
On the other hand, high molecular weight organic polyisocyanates are used as raw materials (
The urethane prepolymer having a meth)acryloyloxy group has an appropriate viscosity, is easy to use as an adhesive, and has satisfactory adhesive properties. Particularly suitable high-molecular organic polyisocyanates in the present invention include polyhydric alcohols having a hydroxyl value of 30 to 200,
It is obtained by reacting with an excess amount of toluene diisocyanate or 4,4'-diphenylmethane diisocyanate.

Urethane prepolymers having (meth)acryloyloxy groups are produced by various methods.

A production method particularly suitable for the present invention is to first react a predetermined amount of an organic polyisocyanate with a (meth)acrylic acid ester having a hydroxyl group to produce a (meth)acryloyloxy compound having an unreacted isocyanate group, and then to produce a (meth)acryloyloxy compound having an unreacted isocyanate group. This is a method of reacting with a required amount of polybasic acid or its anhydride.

In this method, when using a high molecular weight organic polyisocyanate as a raw material, a separately manufactured high molecular weight organic polyisocyanate can be used, or a low molecular weight organic incyanate 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 the production of the urethane prepolymer is preferably 90° C. or lower; if the temperature is too high, the viscosity of the reaction product will increase due to gelation or allophanate formation.

If the reaction temperature is too low, the viscosity of one reactant will increase, and the dispersion and mixing of unreacted raw materials will become insufficient, making it difficult to carry out a smooth reaction. Therefore, one reaction is preferably carried out at around 50°C.

In each step of the synthesis reaction of urethane prepolymer, the group -N
GO is involved and its consumption is involved, and the group -NCO
When analyzed by infrared absorption spectrum, it is 2250crIL-1
Since it exhibits strong absorption characteristics in the vicinity, the progress of the reaction can be easily confirmed by conducting infrared absorption spectrum analysis of the -NCO group in the reactant and tracking its consumption from changes in the intensity of the absorption characteristics. The end point of each reaction step may be taken as the end point of each reaction step when the consumption of the group -NCO has stopped.

The urethane prepolymer having (meth)acryloyloxy groups of the present invention (in the present invention) can be obtained by the method described above.
It can be easily manufactured.

Next, (B) of the first liquid constituting the composition of the present invention
The component is an acrylic compound selected from (meth)acrylic II (herein, acrylic acid and methacrylic acid are collectively referred to as such) and (meth)acrylic acid ester.In the present invention, (B) There is a very wide range of (meth)acrylic acid esters that can be used as a component. Acid esters can be used. Examples of (meth)acrylic acid esters used in the present invention, citing some of these patent publications as appropriate, are as follows:
It is as follows.

[1] A monomer having the general formula or a reaction product of this monomer and an incyanate compound.

However, Ro represents hydrogen or CH3, and % is -CH,
-CH3-, -CH2-CH, -CH3-, or CH
.

-CH-CH5, in which hydrogen at an arbitrary position is eliminated to form a hand for bonding with a %OH group, and n
represents an integer from 1 to 5.

Specifically, the monomer of the general formula [1] is as follows.

2-Hydroxyethyl (meth)acrylate.

2-Hydroxypropyl (meth)acrylate.

1.2-dihydroxyethyl (meth)acrylate, etc.

[2] Monomer of general formula 1.-■. However, R is hydrogen, -CH,yi', -C
m Hs, -CH, OH, or 1 = CH, -0-C-CmCI (t is indicated.

■ R' R' represents hydrogen, chlorine, methyl, or ethyl group.

R' represents hydrogen, -OH1 or =CH, -0-C-C=CHf, m represents an integer R' of 1 to 8, n represents an integer of 1 to 20, and p represents 0 or 1. show.

Specifically, the monomer of the formula (2) includes, for example, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetodiethylene glycol dimethacrylate, 1,2-globylene glycol dimethacrylate,
Diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, di(pentamethylene glycol) dimethacrylate, nato 2 ethylene glycol diacrylate, tetraethylene glycol di(
chloro-acrylate), di-glycerol diacrylate, glycerin trimethacrylate, trimethylolpropane trimethacrylate, di-glycerol tetradimethacrylate, and the like.

[a general formula %formula% A monomer with

However, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R/ represents an alkylene group having 2 to 4 carbon atoms.
represents an integer from 2 to 8.

Specific examples of the monomers having the general formula (2) are as follows.

2.2-bis(4-methacryloxyjethoxyphenyl)propane, 2,2-bis(4-methacryloxytriethoxyphel)propane/, 2゜2-bis(4-methacryloxytetraethoxyphenyl)propane, 2 ,2-
Bis(4-methacryloxypentaethoxyphenyl)propane/, 2゜2-bis(4-methacryloxyhexaethoxyphenyl)propane, 2,2-bis(4-methacryloxyhexaethoxyphenyl)propane, 2゜2-bis (4-methacryloxyoctaethoxy7enyl)propane, 2,2-bis(4-methacryloxydipropoxyphenyl)propane, 2,2-bis(4-methacryloxytripropoxyphenyl)propane, 2,2- Screw(
4-methacryloxyoctabutoquinphenyl)propane, 2゜2-bix(4-methacryloxydibutoxyphenyl)propane, 2,2-bis(4-methacryloxytriptoxyphenyl)propane, 2,2-bis( 4-methacryloxyoctabutoquinphenyl)propane, 2,2
-bis(diphenyl in 4-acryloxyshed)propane, 2,2-bis(4-acryloxydibutoxyphenyl)propane, 2(4-methacryloxyjethoxyphenyl)-2(4-methacryloxytriethoxyphel) Propane, 2(4-methacryloxydipropoxyphenyl)-2(4methacryloxytriethoxyphenyl)
Propane, 2.2-bis(4-αethylacryloxyjethoxyphenyl)propane, 2.2-bis(αpropylacryloxyjethoxyphenyl)propane, 2(4
-αethyl acryloxyjetoxyphenyl)-2(4
-methacryloxyjethoxyphenyl)propane, etc.

[4] General formula CH3 The monomers having the above general formula (2) are specifically listed below. Note that in this specification, acrylate and methacrylate may be collectively referred to as (meth)acrylate.

Dicyclopentenyl (meth)acrylate, dicyclopentenyloxymethyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, etc.

[5] General formula %formula% A monomer indicated by .

However, horses show hydrogen or CH, and birds have 5 to 5 carbon atoms.
20 cycloalkyl group, phenyl group.

It represents a tetrahydrofurfuryl group or an alkyl group containing 5 to 2 carbon atoms.

Specific examples of the monomer of the formula (2) include:

Examples include cyclohexyl (meth)acrylate and tetrahyacrylate.

[6] General formula A monomer indicated by .

However, R-1 represents hydrogen or CH, R1 represents an alkylev group having 2 to 4 carbon atoms, and R1 represents the same group as an alkyl group having 2 to 40 carbon atoms. However, the sum of the carbon numbers of the horse and R1 groups does not exceed 4o.

Specific examples of the monomer of formula [6] include phenoxy-β-hydroxypropyl (meth)acrylate, cyclohexanoxyl β-hydroxypropyl (meth)acrylate, and nato-2hydrofurfuroxyβ-hydroxypropyl (meth)acrylate. ) acrylate, nonyloxy-
Examples include β-hydroxypropyl (meth)acrylate.

[7] General formula A monomer indicated by .

However, RI represents hydrogen or CH, and R3 represents an alkyl group, vinyl group, aryl group, or alkoxyalkyl group having 1 to 20 carbon atoms.

Specific examples of the monomer of the above formula include carbonylmethyl (meth)acrylate, hetoxycarbonylmethyl (meth)acrylate, and isopropoxycarbonylmethyl (meth)acrylate.

Next, the component (C) in the first liquid in the present invention is:
It is a peroxyester that functions as a polymerization initiator for the components (A) and (B), and specific examples thereof include tert-butyl peroxydipenzoate, tert-butyl peroxyacedate, and tert-butyl peroxyacedate. Examples include butylperoxyimputylate, tertiarybutyl dihydrogen cyphthalate, and the like.

The blending ratios of the (λ) component, (B) component, and (C) component in the first liquid are as follows.

In other words, the total amount of component (A) and component (B) is 41
Based on 100 parts by weight (hereinafter referred to as "parts"), component (A) is preferably 70 to 5 parts, more preferably 60 to 10 parts by weight.
Component CB) is preferably 30 to 95 parts, more preferably 40 to 90 parts. In addition, component (C) is (
The amount is preferably 0.01 to 10 parts, more preferably 1 to 7 parts, based on 100 parts of the total amount of component A) and component (B). This is a factor related to the liquid, and the most appropriate blending ratio varies depending on the type of each component, so it is desirable to set the optimal ratio appropriately depending on the components used, and this can be done by a simple test. This can be easily done.

For the first liquid, in addition to the above three components, various polymers as thickeners, chicken tropic agents, dyes, pigments, radical polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, catechol, phenothiazine, diphenylamine, A small amount of additives such as sheet t-7' hydroxytoluene (abbreviated as BHT), an ultraviolet absorber, an antioxidant, and paraffin may be blended.

The second liquid, which together with the first liquid constitutes the composition of the present invention, is a compound (referred to as component (D)) that forms a redox system with the peroxyester of component (C) in the first liquid, that is, a polymerization initiator. It is an accelerator consisting of As the CD) component, any compound that forms a redox system with peroxyester can be used, and such compounds are widely known (widely known), but in the present invention, among them, aldehyde-amine Condensates are most suitable.

Regarding aldehyde-amine composites,
A detailed explanation is given in Japanese Patent No. 7176, and the condensate disclosed in the same patent can be effectively used in the present invention. That is, a suitable aldehyde-amide/condensate is preferably acetic acid.

In the coexistence of carboxylic acids such as propionic acid, butyric acid, and valerian acid, or inorganic acids such as phosphoric acid and sulfuric acid.

At least 1 mol based on the amine condensate, preferably 1.
It is obtained by reacting 0 to 3.5 mol, more preferably 1.5 to 3.0 mol, of an aldehyde, preferably at a temperature of 100 to 175°C. As the aldehyde, aromatic aldehydes such as benzaldehyde and naphthylaldehyde can be used, but aliphatic aldehydes such as formaldehyde, acetaldehyde,
Propionaldehyde, butyraldehyde, heptaldehyde, hexaldehyde, crotonaldehyde, cinnamaldehyde, hydrocinnamaldehyde, 2-phenylpropionaldehyde, etc. are more suitable. On the other hand, the amine used is a primary or secondary aliphatic or aromatic amine. More specifically, as a primary aliphatic amine.

Examples of secondary aliphatic amines include ethylamine, n-propylamine, n-propylamine, i-propylamine, n-hexylamine, t-butylamine, and diethylamine and dipropylamine.

Jimmy propylamine etc. are used as primary aromatic amines such as aniline, p-toluidine, 0-naphthylamine,
p-Naphthylamine, xylidene.

Benzylamine such as p-hensylaniline, and diphenylamine as a secondary aromatic amine.

Examples include N-phenylbenzylamine and N-allylaniline. Examples of useful condensates made from these aldehydes and amines include formaldehyde-p-benzylaniline condensate, acetaldehyde-benzylamine condensate, crotonaldehyde-butylamine feed, cinnamaldehyde-aniline fasteners, skin aldehyde
Butylamine feed, 2-fergropionaldehyde butylamine condensate, butyraldehyde-butylamine condensate, butyraldehyde-aniline condensate, hydrocinnamic aldehyde butylamine condensate, nathaldehyde-〇-toluidine condensate.

Heptaldehyde-N-orylaniline condensate and the like.

Component (D) 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 methylene chloride, trichloroethane,
Rhodinated hydrocarbon solvents such as methylchloroform, trichloroethylene, and trichloromonofluoromethane; ketone or Nisglu II agents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and ethyl acetate; aromatics such as xylene, benzene, and toluene. Examples include hydrocarbon solvents. The concentration of component (D) in the second liquid may be 100% by weight (hereinafter referred to as %), but considering economic efficiency, a lower concentration is suitable,
-1 Too low concentration when applied to the surface of the adherend (1)
A concentration of 0.1 to 30% is preferable since it is difficult to uniformly distribute the components, which may lead to a decrease in adhesive strength.

In the two-component adhesive composition according to the present invention.

By simply bringing the first liquid into contact with the curing accelerator (CD) component in the second liquid, the polymerization and curing reaction of the first liquid immediately starts and proceeds rapidly, achieving a suitable adhesive strength in a short period of time. As shown, 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, this is volatilized. It is most desirable to use this method for bonding together the coated surfaces of each adherend. There are no particular restrictions on the ratio of the applied amounts of the first liquid and the second liquid to the adherend (approximately 10% of the applied amount of component (D) in the second liquid to the applied amount of the first liquid). If the adhesive composition of the present invention is set to about or about this range, the adhesive composition of the present invention will develop excellent adhesive strength in a short period of time.

Next, the present invention will be explained in more detail with reference to Reference Examples and Examples.

[Reference example I]

About 13 parts of toluene diisocyanate (hereinafter referred to as TDI) was placed in a reactor, and while maintaining the reaction temperature at 60 to 70°C al, about 75 parts of polyoxypropylene triol having a molecular weight of about 3,000 was gradually added under stirring to about 1. After stirring for an hour, methacrylic acid 2-hydroxyethyl ester was gradually added to the rim, and the mixture was stirred at 60 to 70°C for about 1 hour.
As a result of the reaction by continuing stirring until the disappearance of the group -NCO was confirmed by analysis, approximately 50.0%
A urethane prepolymer having a viscosity of CPS and having methacryloyloxy groups was obtained. As a result of IR analysis, the following main peaks were confirmed.

-CONH, -0CONH- absorption; 3300-540
0cx, 1730-1740cIL-'.

Absorption of 770-870 α-1 CH, = 6-coo-; 930-950 (!II
-'810-820-1 [Reference Example ■] In the same manner as in Reference Example I except that tartaric acid in Reference Example I was changed to pyromellitic acid and the amount was changed to about 6.5 parts, methacryloyl with a viscosity of about 100,000 cps was prepared. 102.5 parts of a urethane prepolymer having an oxy group was obtained.

As a result of IR analysis of the obtained urethane prepolymer, the same main peak as in Reference Example (2) was confirmed.

[Reference example ■]

Replace the tartaric acid in reference example ■ with anhydrous citric acid, and reduce the amount to approx.
The viscosity was approximately 5% by the same method as in Reference Example ■ except that
0000 cps, 101 parts of a urethane prepolymer having methacryloyloxy groups was obtained.

As a result of IR analysis of the obtained urethane prepolymer, the same main peak as in Reference Example (2) was confirmed.

[Reference example■]

Add about 13 parts of TDI to the reactor and set the reaction temperature to 60-7
While maintaining the temperature at 0°C, about 80 parts of polytetramethylene ether glycol having a molecular weight of about 2000 to 2200 was gradually added under stirring, and after stirring for 1 hour, about 9 parts of methacrylic acid 2-hydroxyethyl ester was gradually added under stirring. , and then about 1 part of tartaric acid is added, and the disappearance of the group -NCO becomes IR.
The reaction was continued at a reaction temperature of 60 to 70°C until confirmed by analysis, and as a result, 10 to 1 parts of a methacryloyloxy group-containing sulfurethane prepolymer having a viscosity of about 50,000 cps was obtained.

As a result of the analysis, the same main peak as in Reference Example I could be confirmed.

[Reference example ■]

Km Example Pi was synthesized in the same manner as in Reference Example 2 except that TDI of Pi was changed to about 19 parts of 4.4'-diphenylmethane diisocyanate and tartaric acid was changed to about 1 part of aconitic acid. 109 parts of urethane premapoly 7- having oxy groups were obtained.

As a result of the IR analysis of the obtained urethane prepolymer, the same main peak as in Reference Example (2) was confirmed.

EXAMPLES Using the urethane prepolymers having methacryloyloxy groups obtained in Reference Examples I to (2), a first solution having the composition shown in Table 1 was prepared. Further, a second solution was prepared by dissolving 20 parts of butyraldehyde-aniline condensed metal product (trade name "Tsukusela 8" by Ouchi Shinko Kagaku Co., Ltd.) in 80 parts of trichloroethane.

Table 1 Using carbon steel adherends, the above first liquid was applied to one adherend, and the above second liquid was applied to the other adherend to volatilize tricloethane. After that, the coated surfaces of each side bonding material 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.
Further, T-shaped peel strength was measured according to JIS K-6854. Regarding set time, adhere to JIS K
-6849, and the time required until it could not be removed by pulling it by hand at room temperature was measured, and the time was defined as the set time.

Table 2 Procedural amendment May 1980 Commissioner of the Japan Patent Office Kazuo Wakasugi 1. Indication of the case 1982 Patent Application No. 54488 2. Name of the invention Acrylic adhesive composition 5. Person making the amendment Case and Relationship of Patent Applicant Address: 1-14-1 Nishi-Shinbashi, Minato-ku, Tokyo, Column 5 of Detailed Description of the Invention of the Specification Subject to Amendment Correct the phrase ``when using the field'' to ``if used.''

(2) On page 8, line 3 of the specification [Organic incyanate] That's right. "Organic polyisocyanate" and correct it.

(3) On page 8, line 13 of the specification "Do it at around 50 degrees Celsius" A certain thing "Carry out at around 50 degrees Celsius, more preferably around 70 degrees Celsius." and correct it.

(4) On page 20, lines 9-10 of the specification, the phrase "preferably at a temperature of 100 to 175°C" should be replaced with "preferably at a temperature of 175°C or lower, more preferably at a temperature of 40 to 175°C."
At a temperature of 00℃.''

(5) On page 27, line 6 of the specification, it says “(Ouchi Shinko Kagaku Co., Ltd. product name ``Tsukucellar 8'')''.
”)” is corrected.

(6) In Table 2 on page 28 of the specification, the "Impact strength" column is corrected to r(kPf-cIR/m)J instead of r(kjLf/m)J.

that's all

Claims (1)

[Claims] (A) A urethane prepolymer having a (meth)acryloyloxy group, which is a reaction product of a (meth)acrylic acid ester having a hydroxyl group, an organic polyisocyanate, and a polybasic acid or its anhydride, CB) (meth)acrylic acid and (C) a polymerization initiator selected from peroxy esters, and (D) the polymerization initiator (C) and a redox system. A two-component acrylic adhesive composition in which the second component is an accelerator consisting of a forming compound.