AU427366B2 - Two-component adhesive composition - Google Patents

Description

25,24 07 The present invention relates to a two-component adhesive composition and a method for binding materials using the same.

Hitherto, there have been known various two-component adhesive compositions to be cured at room temperature. On their use, the components are required to weigh precisely and mixed well together prior to the binding operation. If and when the weighing is made unprecisely or the mixing is effected insuffi- ciently, the adhesion strength may becomp inferior. Further, the adhesive composition after mixing has a pot life and, unless employed within a certain time, the viscosity will increase resulting in solidifying lastly. Moreover, most of the adhesive compositions take a considerable time for curing and the opera- tion efficiency using them is not satisfactory. In order to improve the operation efficiency, heating or warming is occasio- nally effected. In such case, however, a special equipment is needed.

As the results of the extensive .tudy, there has now been provided a two-component adhesive composition overcoming the said drawbacks as seen in the known ones. That is, the adhesive composition of this. invention can be quickly cured at room temperature, assurea the satisfactory adhesion strength and is excellent in the stability on storage. It is particular- ly notable that, different from the known two-component adhesive compositions, the components in the adhesive composition of the invention are not reqaired to mix prior to the use. Thus, the components are separately applied to the materials to be bound and the resulting materials are contacted.each other at the applied portions, followed, by curing to complete the adhesion. Because of such binding mode, it is possible to increase marked-

-2- 427.366

25,24 071. ly the efficiency of the binding operation without any expen- sive equipment. The two-component adhesive composition of the present

invention consists of two component compositions, i.e. a

main composition and an accelerator composition.

The main composition comprises 40 to 80 parts by weight of at least one of divinyl compounds of the formula:

R1 R

CH2 =C C=CH 2 0=C-0-CH 2 -CH-CH 2 0 0-CH H-CH -O0-C=0

C IH CH3 OH CH 3 OH

wherein R1 and R 2 are each hydrogen, methyl or ethyl and n is an integer of 1 to 20, 0.05 to 10 parts by weight of at'least

one of organic hydroperoxides, 0.5 to 15 parts by weight of acrylo- nitrile-butadiene-styrene terpolymer or acrylonitrile-butadiene rubber and 2 to 120 parts by weight of at least one of monovinylic monomers (each vinylic monomer not exceeding 40 parts by weight). The above numerical limitations of the components are

essential for providing the adhesive composition with favorable

properties. Particularly preferred is the composition comprising to 60 parts by weight of at least one of the divinyl compounds, to 5 parts by weight of at least one of organic hydro-

peroxides, 1 to 10 parts by weight of acrylonitrile-butadiene- 120 styrene terpolymer or acrylonitrile-butadiene rubber and 10 to parts by weight of at least one of monovinylic monomers

(each viny-lic monomer not exceeding 40 parts by weight). The main polymerizable component in the main composi-

tion is the divinyl compound, which is per se known[cf. U.S Q 427.366

24 0 1 patent 3,373,075; British patent 1,006,587 The other polymerizable component is a vinylic monomer,

of which examples are acrylic acid, vinyl acetate and B- hydroxyethyl methacrylate. The incorporation of such vinylic

monomer is effective in increasing the curing rate and the primary adhesion strength. The dCrylonitrile-butadiene-styrene terpolymer and the acry1dnitrile-butadiene rubber are well known as "ABS resin" and "NBR", respectively. Those are available as a formulating agent for improving the impact strength and the shear strength of the adhesion resulting from the application of the adhesive composition. The organic peroxide is used as a polymerization

initiator and may be normally a hydroperoxide such as cumene hydroperoxide, methylethylketone hydroperoxide, 2-methylbutene- 1-hydroperoxide, 2,5-dimethylhexane dihydroperoxide and t- butyl hydroperoxide. When desired, the main composition may include one or more additives such as coloring materials, plasticizers and prdellants in addition to the said essential components. The accelerator composition comprises 0.01 to parts by weight of at least one of thiourea derivatives, 0.01 0 0.001 to 5 parts by to 10 parts by weight ofa '-dipryidyl, weight of at least one of metal salts of organic or inorganic acids and 100 to 75 parts by weight of at least one of volatile organic solvents. Although the composition including the bove components in the said numerical limitations is suitable, the more preferred is the one comprising-0.1 to 7 parts by weight of at least one of thiourea derivatives, 0.05 to 5 parts by wieght of 4 427.366

25,24 0 /71 dipyridyl, 0.001 to 3 parts by weight of at least one of metal salts of organic or inorganic acids and 100 to 75 parts by weight of at least one of volatile organic solvents.

Examples of the thiourea derivatives are trimethyl- thiourea, dipropionylthiourea, diacetylthiourea, tetramethyl- thiourea, etc. As the metal salts of organic or inorganic acids, there may be employed hydrochlorides, sulfates, nitrates, phosphates, aliphatic carboxylates and aromatic carboxylates of copper, cobalt, manganese, vanadium and chromium. Particular- ly preferred are lower alkanoic acid salts acetate) and naphthenates of the said metals. These substances andpU)- dipyridyl are available as the accelerators for the polymeriza- tion of the polymerizable monomer components in the main composi-

tion. Although each of them serves alone as an accelerator, only the combined use of at least one of the thiourea derivatives, T,a'-dipryidyl and at least one of the metal salts of organic

or inorganic acids can assure the favorable instantaneous curing property and the excellent primary adhesion strength of the adhe- sive composition of the invention. Further, such combined use is advantageous, because the resultant accelerator composition is quite stable on storage for a long duration.

Examples of the volatile organic solvent used as the medium for the above accelerator substances are alcohols (e.g. methanol), ketones (e.g.acetone, methylethylketone), esters, halogenated hydrocarbons methylene chloride, trichloro- ethylene, chlorofluoroethylene), etc.

When desired, one or more additives such as coloring materials, plasticizers and propellants may be incorporated into the accelerator composition besides the said essential components.

427.366

25.240/71 For binding materials by the use of the two-component adhesive composition of the invention, the main composition is

applied to one of the materials to be bound and the accelerator

composition to the other, both materials are then contacted close- ly at the applied portions and then the thus bound materials are cured for completion of the adhesion. The satisfactory adhesive

state with the sufficient tensile strength and shear strength can be attained instantaneously by curing at room temperature.

In the above binding operation, the application of the accele- rator composition may be made previously so that the efficiency in the operation will be much elevated just like a conventional one-component adhesive composition. .The materials to be bound may be made of metals (e.g. iron, copper, nickel), plastics polyvinyl chloride resin,

polyacrylic resin, polyepoxy resin), woods, glass, pottery or the like. The application can be effected in a conventional

manner, e.g. painting, spraying, etc. Practical and presently preferred embodiments of the present invention -are illustratively shown in the following Examples wherein parts and are by weight.

Example 1 In a flask equipped with an agitator, there are charged bisphenol A diglycidyl ether ("Epokote 828" manufactured by Shell Petroleum Co., Ltd) (190 parts) and methacrylic acid )80 parts), and triethylamine (5.8 parts) is added thereto at 500C while stirring. ("Epikote" is a Registered Trade Mark). After

maintaining at 50°C for 5 hours, acrylic acid (20 parts)

is added to the resulting mixture, and the reaction is carried

g 427.366

25,24 0/71 out at the same temperature for 10 hours to give a liquid comprising the divinyl compound, of 5000 to 10000 cps in viscosity (hereinafter referred to as "liquid (290 parts). The liquid A (100 parts) is admixed with a vinylic monomer as shown in Table 1, and cumene hydroperoxide (3 parts) and NBR (6 parts) are added thereto to make a main composition. Sepa- rately, tetramethylthiourea (0.8 part), cobalt acetate (0.01 part),.,a'-dipyridyl (1.0 part) and cobalt naphthenate (0.05 part) are dissolved in acetone (100 parts) to make an accele- rator composition.

On the top surface of a steel-made cylindrical piece of 1 cm2 in section area, the accelerator composition is applied. After 30 seconds, the applied surface is closely contacted with the bottom surface of another steel-made cylindrical piece'of 2 1 cm in section area the said bottom surface having been applied the main composition prior to the contacting. The tensile strength is measured 5 minutes, 15 minutes and 24 hours after the contacting.

The results are shown in Table 1, from.which it is seen that the incorporation of the vinylic monomer into the main composition results in the increase of the tensile strength and the primary adhesion strength.

Table 1

427.366

25,240/71

Vinylic monomer Tensile strength after contact (kg/cm Kind Amount added-k/m (part) 5 min. 15 min. 24 hours-

None 0 38 120 235 Vinyl acetate 30 195 210 280 Acrylic acid 10 190 269

-Hydroxy- ethyl meth- 30 189 260 327 acrylate

Example 2 The liquid A obtained in Example 1 (100 parts) is

admixed with cumene hydroperoxide (4 parts), NBR in an amount as shown in Table 2, acrylic acid (20 parts) and vinyl acetate

parts) to make a main composition. Using the main composition and the accelerator compo- sition as shown in Table 2, two steel-made cylindrical pieces are adhered each other in the same manner as in Example 1.

The tensile strength is measured 30 seconds, 1 minute, 5 minutes

and 24 hours after the adhering. The results are shown in Table 2, from which it is seen that a considerable adhesion strength is attained in-an

extremeely short time.

427.366

Table 2 2S.24 0 7l

NBR IAccelerator composition Tniestrength2 after contact conntint (kg/cm (partr 'Components 'Content (part) 30 sec~f min. 5 min. 24 hrs.

0,d'-Dipyridyl 1.2 Tetramethyl- thiourea Q.9

Cobalt chlbo rj~e0.01

74 180 389 Manganese 4cetate 0.02 Acetone 100

Tetramethyl- 0.9

thiourea 4 Cobalt I 0.01 12 40 162 378 chloride Manganese 0.02 acetate Acetonie 100j IiW-Dipyridyl 0.05

N,NI-Diacetyl- 2.9 thiourea opppr acetate 0.006 10 43 172 407 cetone 100

427,366

25,24 0/71 (Continued) NER Accelerator compositioln Tens ile strength content after contact (kg/cm 2 (art) C-omponents IContent (Part.) 130 sec.1 min. 5 min.124 hrs. Il,a'-Dipyridyl 0.7 Trimethythi..2. 3 4urea 2.3 16F.4 Cobalt acetate 0.002 13 4 16 31 Acetone 100 a,a'-Dipyridyl 0.07 N,N'-Dipro- 2.83- pionylthiourea 4 Chromium 012 14 40' 158 385 naphthenate 0.1 Acetone 100 a,a'-Dipyridyl 0.05 Tetranethyl- thiourea 0.1 Vanadium 00 4 chloride 0.01 15 Copper 2800.85 naphthenate 00 A mixture of acitone and 100 ethanol (8:2)

Example 3 The liquid A obtained in Example 1 (100 parts) is admixed with cumene hydroperoxjide (2.5 parts), acrylic acid parts) and vinyl acetate (30 parts), and ABS resin or NBR in an amount as shown in Table 3 is added or not thereto to make a main c~mpsition. Separately, tetramethylthiourea (0.5 parts), a,c'-dipyridyl (1.0 part), cobalt naphthenate (0.05 part) and- cobalt acetate'(0.01 part) are dissolved in acetone (100 parts) to make an accelerator composition.

The accelerator composition is applied on the one sur- face of a steel-made rectangular strip of 2.54 cm in width, 12.0

427.366

24 0 t7t cm in length and 5 mm in thickness, the application being made

about 2 cm wide from the one edge. The main composition is

applied on the one surface of another steel-made rectangular

strip as above in the similar manner. The said strips are

contacted each other at the applied portions (1.5 cm overlap).

After 24 hours, the shear strength is measured. The results are shown in Table 3, from which it is

seen that the shear strength is markedly increased by the.

incorporation of ABS resin or NBR into the main composition. Table 3

Additive Shear strength 2 Kind Amount added (kg/cm (part) None 0 ABS resin 8 380 256

NBR 8 290 298 280

Example 4 Theliquid A obtained in Example 1 (100 parts) is admixed with acrylic acid (40 parts), vinyl acetate (30 parts) and NBR (7 parts), and cumene hydroperoxide (4 parts) is added thereto to make a main composition. Separately, tetramethyl-

thiourea (0.9 part), a,a'-dipyridyl (0.08 part), cobalt acetate (0.01 part) and cobalt naphthenate (0.01 part).are dissolved in acetone (i:00 parts) to make an accelerator composition. Using the main composition and the accelerator composi- tion, the tensile strungth and the shear strength with the lapse.

of time after adhesion are measured respectively as in Examples

land 3. 3 66

25240/71 The results are shown in Table 4, from which it is

seen that the tensile strength and the shear strength are quite excellent and can be attained rapidly after adhesion. Table 4

Lime elapsed Tensile strength Shear strength after adhesion (k,/c/m2 (kg/cm sec. 32

1 min. 98 2 min. 119 .3min. 185 min. 226 215 24 hrs. 322 290 48 hrs. 360 The accelerator composition obtained as above is chargt in a glass bottle and stored in a desiccator at 500 C for 1 month. Then, the tensile strength and the shear strength with the lapse.

of time after adhesion are measured in the same manner as above. The results are shown in Table 5, from which it is seer that the accelerator composition is excellent in storage stabilit Table

Time elapsed Tensile strength Shear strength after adhesion (kg/c 2 (kF/cm2 sec. 36 min. 214 108 24 hrs. 340 272 48 hrs. 353 285 For comparison, there are prepared accelerator composi-

tions lacking one of tetramethylthiourea, a,a'-dipyridyl and cobalt acetate cobalt naphthenate. Using such accelerator

compositions, the tensile strength are measured in the same

manner as above. 1 4 2 -736

L524 0 17 The results are shown in Table 6, from which it is seen

that all these accelerator compositions can not realize the good adhesion so rapidly as the accelerator composition obtained in

the above Example does and are inferior to the latter in the

stability on storage. Table 6

Components Tensile strength ensile strength in accelerator (before s orage) after storage composition (kg/cm') at 500 C fqr 1 month) (in acetone) 3 min. afte 24 hrs. after (kg/cm adhesion adhesion 3 min. after 124 hrs. aftez adhesion ladhesion etramethyl- thiourea 34 332 38 319 a,a'-Dipyridyl a,a'-Dipyridyl Cobalt acetate 15 326 13 330 Cobalt naphthe nate Tetramethyl- thiourea Cobalt acetate 130 281 85 277 Cobalt nate naphthe- W-h_R t ele~med le

42 7,366

Claims (1)

1. 25,240171 The claims defining the invention are as follows:-

   1. A two-component adhesive composition consisting

   of a main composition comprising 40 to 80 parts by weight of at least one of divinyl compounds of the formula:

   R 2 CH c 2 /3fo .4 Cr C H-CH C=CH22 0 0 0=C-0-CH2-CH -CH-04/\ -CH2-CH-CH 2 _nO

   OH CH 3 OH

   wherein R1 and R2 are each hydrogen, methyl or ethyl and n is an integer of 1 to 20, 0.05 to 10 parts by weight of at least one of organic hydroperoxides, 0.5 to 15 parts by weight of acrylonitrile-butadiene-styrene terpolymer or acrylonitrile- butadiene rubber and 2 to 120 parts by weight of at least one of monovinylic monomers (but each vinylic monomer not exceeding parts by weight) and an accelerator composition comprising 0.01 to 10 parts by weight of at least one of thiourea derivatives, 0.01 to 10 parts by weight of a,a-dipyridyl,

   0.001 to 5 parts by weight of at least one of metal salts of organic or inorganic acids and 100 to 75 parts by weight of at least one of volatile organic solvents. 2. The two-component adhesive composition according

   to claim 1, wherein the main composition comprises 50 to parts by weight of at least one of the divinyl compounds, to 5 parts by weight of at least one of organic hydroperoxides, 1 to 10 parts by weight of acrylonitrile-butadiene-styrene

   terpolymer or acrylonitrile-butadiene rubber and 10 to 120 parts by weight of at least one of monovinylic monomers (but each Svinylic monomer not exceeding 40 parts by weight) and the

   accelerator composition comprises 0.1 to 7 parts by weight 427,366

   25,24 0 71 of at least one of thiourea derivatives, 0.05 to 5 parts by weight of d,a- dipyridyl, 0.001 to 3 parts by weight of at least one of metal salts of organic or inorganic acids and 100 to 75 parts by weight of at least one of volatile organic solvents. 3. The two-component adhesive composition according to claim 1, wherein at least one of the main composition and the accelerator composition comprises at least one of coloring materials, plasticizers and propellants. 4. The two-component adhesive composition according to claim 1, wherein the organic peroxide is cumene hydroperoxide, methylethylketone hydroperoxide, 2-methylbutene-l-hydroperoxide, dihydroperoxide or t-butyl hydroperoxide. The two-component adhesive.composition according to claim 1, wherein the vinylic monomer is acrylic acid, vinyl acetate or ~-hydroxyethyl methacrylate. 6. The two-component adhesive composition according to claim 1, wherein the thiourea derivative is trimethyl- thiourea, dipropionylthiourea, diacetylthiourea or tetramethyl- thiourea. 7. The two-component adhesive composition according to claim 1, wherein the metal salts of organic or inorganic acids, are hydrochlorides, sulfates, nitrates, phosphates, aliphatic carboxylates or aromatic carboxylates of copper, cobalt, manganese, vanadium or chromium. 8. A method for adhering a material on another material which comprises applying a main composition comprising to 80 parts by weight of at least one of divinyl compounds

   427.366

   24 0P1 of the formula:

   CHCH R CH 2 C 3 Y I I eH 2

   0=C-0-CH -CH -CH -C -0-CH-CHCH -0-C=0 2 1 2 -C

   OH CH OH 3 wherein R, and R2 are each hydrogen, methyl or ethyl and n

   is an integer of 1 to 20, 0.05 to 10 parts by weight of at least one of organic hydroperoxides, 0.5 to 15 parts by weight

   of acrylonitrile-butadiene-styrene terpolymer or acrylonitrile butadiene rubber and 2 to 120 parts by weight of at least one of vinylic monomers (but each monovinylic monomer not exceedin

   parts by weight) to the material and an accelerator com- position comprising 0.01 to 10 parts by weight of at least one of thiourea derivatives, 0.01 to 10 parts by weight of d-,'-dipyridyl, 0.001 to 5 parts by weight of at least one

   of metal salts of organic or inorganic acids and 100 to parts by weight of at least one of volatile organic solvents to the other material and contacting the resulting materials

   with each other. 9. The method according to claim 8, wherein the material to which is applied the accelerator composition is dried and then contacted with the material to which is applied

   the main composition.

   Dated this 5th day of February, 1971. SUMITOMO CHEMICAL COMPANY, LIMITED By their Patent Attorneys, A. WALLACE SMITH CO.

   16 427.366