Room temperature setting adhesive composition

A room temperature setting adhesive composition capable of giving high initial bond strength as well as cured bonds having good resistance to water and boiling contains, as main components thereof, (A) an emulsion containing an acetoacetylated polyvinyl alcohol and a vinyl acetate copolymer produced by copolymerizing an acetoacetylated, ethylenically unsaturated monomer and another ethylenically unsaturated monomer and (B) a resorcinol resin precondensate and, as a curing agent, (C) hexamethylenetetramine.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a room temperature setting adhesive composition 
capable of giving high initial bond strength and cured bonds having good 
water resistance and good boiling water resistance. 
2. Description of the Prior Art 
Emulsions based on polyvinyl acetate or vinyl acetate copolymers 
(hereinafter referred to as "PVAc emulsions") are in general use as room 
temperature setting adhesives. However, when used for bonding purposes, 
such PVAc-based emulsions give cured products or bonds poor in water 
resistance and in boiling water resistance, so that their use is limited 
to indoor applications. To remedy such disadvantage, adhesives comprising 
a PVAc emulsion, a resorcinol resin precondensate and formaldehyde or 
paraformaldehyde and adhesives of the same nature as above except that 
hexamethylenetetramine is used in lieu of said aldehyde have already been 
proposed. 
However, the adhesives obtained by admixing a resorcinol resin 
precondensate and formaldehyde or paraformaldehyde with the 
above-mentioned PVAc emulsion have a strong formalin odor and this is of 
no small concern from the safety and hygiene viewpoint. Moreover, formalin 
released from such adhesives may offer various problems on the adherend 
side. As for the adhesives in which hexamethylenetetramine is used in lieu 
of the aldehyde and which can thus be regarded as improved forms, such 
problems due to the use of formalin as mentioned above can indeed be 
solved but said adhesives are still disadvantageous in that the rate of 
curing is very slow at room temperature, so that heating after spreading 
is required for their practical use. To remove such drawback, an adhesive 
has been proposed which comprises a vinyl acetate emulsion containing an 
acetoacetylated polyvinyl alcohol, a resorcinol resin precondensate and 
hexamethylenetetramine. This adhesive is advantageous in that it can be 
cured rapidly at room temperature and has very little formalin odor. 
Regrettably, however, the use of the above resorcinol resin precondensate 
in an amount not lower than a certain threshold level is essential for 
said adhesive to give cured products which are satisfactory with respect 
to water resistance, boiling water resistance, etc., but the use of the 
resorcinol resin precondensate in increased amounts disadvantageously 
causes a decrease in initial bond strength. 
SUMMARY OF THE INVENTION 
It is an object of the invention, which has now been made in such 
circumstances, to provide a room temperature setting adhesive composition 
capable of giving bonds excellent in all aspects, including water 
resistance and boiling water resistance, with high initial bond strength 
and producible with minimal formalin odor emanation without offering 
particular safety or hygiene problems. 
In accordance with the invention, the above object can be accomplished by 
providing a room temperature setting adhesive composition containing, as 
main components thereof, (A) a polyvinyl acetate emulsion containing an 
acetoacetylated polyvinyl alcohol and (B) a resorcinol resin precondensate 
and, as a curing agent, (C) hexamethylenetetramine characterized in that 
said polyvinyl acetate emulsion is an emulsion of a vinyl acetate 
copolymer produced by copolymerizing an acetoacetylated, ethylenically 
unsaturated monomer and another ethylenically unsaturated monomer.

DETAILED DESCRIPTION OF THE INVENTION 
The present inventors conducted an intensive study to improve the 
above-mentioned adhesive composition according to the latest proposal with 
particular attention to the acetoacetylated polyvinyl alcohol-containing 
polyvinyl acetate emulsion, which is the main component. As a result, it 
has been found that the above-mentioned object can be achieved when a 
vinyl acetate polymer produced by copolymarization of an acetoacetylated, 
ethylenically unsaturated monomer and another ethylenically unsaturated 
monomer, not a simple vinyl acetate polymer, is used as the polymer in the 
above mentioned polyvinyl acetate emulsion. The present invention has been 
completed on the basis of this finding. 
The room temperature setting adhesive composition is produced from said 
vinyl acetate emulsion containing an acetoacetylated polyvinyl alcohol 
(hereinafter, "AAcPVA polymer"), a resorcinol resin precondensate and 
hexamethylenetetramine (hereinafter, "HMTA"). 
The AAcPVA polymer to be contained in the above-mentioned emulsion is used 
for the purpose of increasing the stability of the vinyl acette polymer 
emulsion as well as for the purpose of improving the compatibility of said 
emulsion with said resorcinol resin precondensate and can be produced by a 
known method, namely by acetoacetylating a polyvinyl alcohol (hereinafter. 
"PVA" polymer with an acetoacetylating agent in ordinary use, such as 
diketene, acetoacetic acid or an acetoacetate ester. Thus, for example, it 
can easily be obtained using diketene, for instance, by the method 
comprising adding a PVA polymer to acetic acid and then adding diketene 
for effecting the acetoacetylation reaction, by the method comprising 
adding diketene to a solution of a PVA polymer in a solvent such as 
dimethylformamide or dioxane to thereby effect the reaction, by the method 
comprising directly reacting a PVA polymer with diketene or by the like 
known method. As the PVA polymer to be used in that case, there may be 
mentioned a partial or complete saponification product derived from 
polyvinyl acetate, a saponification product derived from a copolymer of 
vinyl acetate and one or more other ethylenically unsaturated monomers, 
and a partial acetalization product derived therefrom, for instance. 
Water-soluble ones are preferred and, among them, polyvinyl alcohol 
species having a degree of polymerization of 200-3,000 and a degree of 
saponification of 30-100 mole percent are most suitable. The degree of 
acetoacetylation of the AAcPVA polymer obtained in the above manner should 
preferably be within the range of 0.1-15 mole percent, in which adhesive 
compositions prepared in accordance with the invention can give good 
results with respect to reactivity water resistance of bonds and stability 
of emulsion. 
The vinyl acetate polymer, which is the main component of the 
above-mentioned emulsion, can be prepared by copolymerizing an 
acetoacetylated, ethylenically unsaturated monomer (hereinafter, "AAc 
monomer") and another ethylenically unsaturated monomer. Said AAc monomer 
can be prepared by acetoacetylating hydroxyethyl acrylate or hydroxyethyl 
methacrylate, for instance, with an acetoacetylating agent in common use, 
such as diketene, acetoacetic acid or an acetcacetate ester. When 
diketene, for instance, is used as the acetoacetylating agent, the AAc 
monomer can readily be obtained by a known method, for example by adding 
phenothiazine (polymerization inhibitor) and triethylamine (catalysts) 
i.e., hydroxyethyl acrylate or the like and adding diketene thereto slowly 
thereby effecting the reaction. Said other ethylenically unsaturated 
monomer means vinyl acetate or a mixture of vinyl acetate and one or more 
other ethylenically unsaturated monomers such as (meth)acrylic acid, alkyl 
(meth)acrylates, ethylene, styrene, vinyl chloride and vinyl versatate. 
The resorcinol resin precondensate to be used in the practice of the 
invention is, for example, a precondensate from a resorcinol, such as 
resorcinol or an alkylresorcinol, and an aldehyde, such as formaldehyde, 
or a precondensate from a resorcinol plus a phenol, such as phenol, or an 
amine, such as urea, melamine or guanamine, and an aldehyde. More 
specifically, there may be mentioned resorcinol-aldehyde precondensate, 
alkylresorcinol-aldehyde precondensate, resorcinol-phenol-aldehyde 
precondensate, alkylresorcinol-phenol-aldehyde precondensate, 
resorcinol-melamine-aldehyde precondensate, resorcinol-urea-aldehyde 
precondensate and resorcinol-quanamine-aldehyde precondensate, among 
others. Particularly preferred among these resorcinol resin precondensates 
are resorcinol-aldehyde precondensate, alkyl-resorcinol-aldehyde 
precondensate, resorcinol-phenol-aldehyde precondensate and 
alkylresorcinol-phenol-aldehyde precondensate. These resorcinol resin 
precondensates can be produced by an ordinary method, for example, by 
adding formalin slowly to a solution of resorcin in a solvent, such as an 
alcohol, in the presence of a catalyst, such as oxalic acid to thereby 
effect the reaction. 
Any grade of HMTA which is in general use can be used in the practice of 
the invention. 
The room temperature setting adhesive composition according to the 
invention is produced by compounding the vinyl acetate polymer emulsion 
(A) containing the above-mentioned AAcPVA polymer, the resorcinol resin 
precondensate (B) and hexamethylenetetramine (HMTA) (C). It can be 
produced in the following manner, for instance. 
Thus, the AAcPVA polymer-containing vinyl acetate polymer emulsion (A) is 
prepared by emulsion-polymerizing an AAc monomer and a monomer such as 
vinyl acetate in the presence of an AAcPVA polymer. In this connection, 
the proportion of AAc monomer is preferably in the range of 0.4-20 weight 
percent (hereinafter referred to briefly as %) based on the total amount 
of the constituent monomers of the vinyl acetate polymer. If the 
proportion is less than 0.4%, it is necessary to add a large amount of 
resorcinol resin precondensate in order to ensure a sufficient resistance 
of the bond to water, boiling, etc. and consequently the initial bond 
strength tends to deteriorate. On the other hand, if the proportion of AAc 
monomer exceeds 20%, it becomes difficult to copolymerize vinyl acetate 
and other monomers so that a stable emulsion is hardly obtainable. Even if 
the resulting emulsion is stable at any rate, the final adhesive will have 
only a short pot life and be of little practical use. 
The preferred AAcPVA polymer content of the above emulsion (A) on a 
nonvolatile matter basis is 0.2 to 20 weight parts (hereinafter referred 
to briefly as parts) to each 100 weight parts of the vinyl acetate 
polymer. If the proportion is less than 0.2 parts, the water resistance of 
the resulting bond is insufficient and the compatibility of the emulsion 
with the resorcinol resin precondensate tends to deteriorate. On the other 
hand, if the proportion of AAcPVA polymer exceeds 20 parts, the water 
resistance of the bond tends to decrease because the AAcPVA polymer itself 
is inherently water-soluble. 
The emulsion polymerization may be carried out by the conventional method. 
The AAcPVA polymer itself can act as an emulsifying agent and, therefore, 
the emulsion polymerization of an AAc monomer with vinyl acetate and/or 
other monomer in the presence of a resorcinol polymer does not require an 
emulsifying agent but an ordinary nonionic surfactant may be added in a 
suitable amount. As the emulsion polymerization catalyst, choice may be 
made from among the catalysts commonly used for emulsion polymerization, 
such as persulfates, hydrogen peroxide, redox catalysts and so on. 
To the emulsion (A) obtained in the above manner is added a resorcinol 
resin precondensate (B). The preferred mixing ratio is 10 to 50 parts of 
(B) to each 100 parts of (A). If the proportion of (B) is less than 10 
parts, water resistance, boiling resistance, etc. of the bond are not 
fully satisfactory. On the other hand, if the proportion of (B) exceeds 50 
parts, there is a marked reduction in initial bond strength. 
The above-mentioned HMTA is then added to the resorcinol resin 
precondensate-containing emulsion (A)+(B) thus obtained. Regarding the 
proportion of HMTA, it is preferable from the standpoint of water 
resistance of the bond to use 2 to 30 parts of HMTA to each 100 parts of 
(A)+(B) on a nonvolatile matter basis. 
If necessary, the above composition may be supplemented with fillers such 
as calcium carbonate, talc, clay, etc. and/or film coalescing aids such as 
dibutyl phthalate, dioctyl phthalate, butylcarbitol acetate, 
tetrahydrofurfuryl alcohol and so on. 
By the above series of procedures, there can be obtained a room temperature 
setting adhesive composition according to the present invention. This room 
temperature setting adhesive composition is put to use by mixing the 
above-mentioned components A to C. And this adhesive composition is 
odorless, features a high initial bond strength, and provide a cured 
product excellent in water resistance and boiling resistance. 
It will be apparent from the foregoing description that the room 
temperature setting adhesive composition according to the present 
invention has no formalin odor because it does not contain an aldehyde 
such as formaldehyde or paraformaldehyde, is easy to work with, and is 
capable of bonding wood, bamboo, cloth and other adherends firmly at room 
temperature. Furthermore, as the bond after curing is highly resistant to 
water and boiling, for instance, this adhesive composition can be used 
advantageously in outdoor applications for which the conventional 
adhesives are not suited. Moreover, as the adhesive composition of the 
present invention shows a high initial bond strength, the pressure time 
necessary for bonding adherends is reduced so that the efficiency of 
bonding work is improved. 
The following working and comparative examples are further illustrative of 
the present invention. 
EXAMPLES 1-11 
The AAc monomer acetoacetoxyethyl acrylate was synthesized. Thus, a 
separable flask equipped with a stirrer, reflux condenser, dropping funnel 
and thermometer was charged with 290 parts of 2-hydroxyethyl acrylate, 
0.025 part of phenothiazine and 0.025 part of triethylamine. While 
replacing the flask inside atmosphere with nitrogen gas, the flask 
contents were heated to 70.degree. C. Then, while maintaining the flask 
inside temperature at 70.degree. C., 220 parts of diketene was added 
dropwise over 1.5 hours, followed by further two hours of reaction at the 
same temperature whereby the desired acetoacetoxyethyl acrylate was 
obtained. The disappearance of the hydroxyl group was confirmed by 
infrared spectrophotometry of the product. 
Using the above acetoacetoxyethyl acrylate, an emulsion (A1) was produced. 
Thus, a separable flask equipped with a stirrer, reflux condenser, 
dropping funnel and thermometer was charged with 150 parts of water, 11 
parts of an AAcPVA (Nippon Synthetic Chemical Industry's GOHSEFIMER-Z-100; 
product of 5 mole percent acetoacetylation of PVA (degree of 
polymerization 500, degree of saponification 99 mole percent)) and 10 
parts of vinyl acetate. The flask contents were heated to 60.degree. C., 
while replacing the flask inside atmosphere with nitrogen gas, with 
addition of 5 parts of 2% aqueous potassium persulfate as the 
polymerization catalyst. After 30 minutes of prepolymerization, 65 parts 
vinyl acetate, 5 parts of the AAc monomer acetoacetoxyethyl acrylate and 
20 parts of vinyl versatate VV-10 (Shell Chemical) (ethylenically 
unsaturated monomer other than vinyl acetate) were added dropwise over 3 
hours. After completion of the addition of all the monomers, the whole 
mixture was ripened at 75.degree. C. for 1 hour to give a vinyl 
acetate-acetoacetylated monomer copolymer emulsion containing the AAcPVA 
polymer. 
A resorcinol resin precondensate (B1) was prepared. Thus, a separable flask 
equipped with a stirrer, reflux condenser, dropping funnel and thermometer 
was charged with 220 parts of resorcinol, 97.4 parts of 37% aqueous 
formaldehyde and 0.8 part of oxalic acid. The flask contents were heated 
to 55.degree. C. with stirring. After heating at this temperature for 1 
hour, the reaction mixture was cooled, followed by adjustment of the pH to 
8.2 by adding 30% aqueous sodium hydroxide. Thus was obtained a resorcinol 
resin precondensate (B1). The thus-obtained emulsion (A1) and resorcinol 
resin precondensate (B1) were used, together with hexamethylenetetramine 
(HMTA), in the proportions given in Table 1 to make up seven adhesive 
compositions (Examples 1-11). 
COMATIVE EXAMPLES 1-5 
For comparison, AAc monomer-free adhesive compositions were prepared in the 
same manner as in the above examples. Thus, in the comparative examples an 
emulsion (X) was prepared by using 70 parts of vinyl acetate in lieu of 65 
parts of vinyl acetate plus 5 parts of acetoacetoxyethyl acrylate used in 
the production of emulsion (A1) in the above examples. The emulsion (X), 
the resorcinol resin precondensate (B1) and hexamethylenetetramine were 
blended in the proportions given in Table 2 to give 5 adhesive 
compositions (Comparative Examples 1-5). 
The adhesive compositions thus obtained in Examples 1-11 and Comparative 
Examples 1-5 were subjected to bond strength testing by the methods 
mentioned below. The test results obtained are shown in Table 1 and Table 
2. 
[Bond strength test 1] 
Birch blocks were used to prepare test specimens. According to JIS K 6804, 
the blocks were bonded together in pairs using each of the above adhesive 
compositions in a spread of about 200 g/m.sup.2 and kept under pressure 
for 1 day. After release of pressure loading, the test specimens were 
allowed to stand for 48-72 hours and then measured for bond strength. 
Another set of test specimens prepared by bonding, keeping under pressure 
and pressure removal in the same manner as above were immersed in water at 
20.degree. C. for 24 hours and then measured for bond strength for 
comparison with respect to water resistance. Similarly, test specimens 
after removal of pressure loading were immersed in boiling water for 72 
hours, then cooled and tested for bond strength for comparison with 
respect to boiling water resistance. Furthermore, the bond strength after 
repeated boiling was measured by the method described in JIS K 6802. For 
initial bond strength measurement, hemlock spruce boards, 40 mm in width 
and 80 mm in length, were prepared and coated on both sides with each 
adhesive composition in a spread of 300 g/m.sup.2. Immediately thereafter 
a plywood piece, 50 mm in width and 100 mm in length, was applied to each 
side. A pressure of 7 kg/cm.sup.2 was applied to the specimens obtained in 
this manner for 20 minutes and, immediately after removal of pressure 
loading, the plywood pieces bonded to both sides of the hemlock spruce 
board were drawn apart at a drawing rate of 100 mm/min and the force 
required to cause failure of the bond was recorded. 
TABLE 1 
__________________________________________________________________________ 
Example 
1 2 3 4 5 6 7 8 9 10 11 
__________________________________________________________________________ 
Adhesive 
(Al) 
100 100 100 100 100 100 100 100 100 100 100 
component 
(Bl) 
5 10 20 35 50 70 20 20 20 20 20 
(parts) 
HMTA 
10.5 
11.0 
12.0 
13.5 
15.0 
17.0 
1.2 
2.4 
18.0 
36.0 
48.0 
Odor Odor- 
Odor- 
Odor- 
Odor- 
Odor- 
Odor- 
Odor- 
Odor- 
Odor- 
Odor- 
Odor- 
less 
less 
less 
less 
less 
less 
less 
less 
less 
less 
less 
Property of mixture 
Good 
Good 
Good 
Good 
Good 
Good 
Good 
Good 
Good 
Good 
Good 
Bond strength 
200 200 210 200 200 210 180 200 200 200 200 
(20.degree. C.) 
Bond strength after 
80 90 120 110 110 100 70 90 110 110 80 
immersion in water 
for 24 hours 
Bond strength after 
20 40 90 80 100 90 40 60 80 80 40 
immersion in boiling 
water for 72 hours 
Bond strength after 
40 60 110 100 110 100 50 70 110 100 50 
repeated boiling 
Initial bond strength 
27 26 24 16 12 8 22 23 22 24 23 
(kg/4 cm) 
__________________________________________________________________________ 
TABLE 2 
______________________________________ 
Comparative Example 
1 2 3 4 5 
______________________________________ 
Adhesive 
(X) 100 100 100 100 100 
component 
(B1) 10 20 35 50 70 
(parts) HMTA 11.0 12.0 
13.5 
15.0 
17.0 
Odor Odor- Odor- Odor- Odor- Odor- 
less less less less less 
Property of mixture 
Good Good Good Good Good 
Bond strength 
170 190 200 200 210 
(20.degree. C.) 
Bond strength 
40 60 70 90 110 
after immersion 
in water for 24 hours 
Bond strength after 
0 20 40 60 90 
immersion in boiling 
water for 72 hours 
Bond strength after 
20 30 60 80 100 
repeated boiling 
Initial bond strength 
25 23 16 11 7 
(kg/4 cm) 
______________________________________ 
Comparing Examples 1 to 6 in Table 1 with Comparative Examples 1 to 5 in 
Table 2, one finds that the adhesive compositions according to the present 
invention are excellent in water resistance and bond strength after 
boiling notwithstanding the low resorcinol resin precondensate (B1) 
contents. Thus, whereas the adhesive compositions of the Comparative 
Examples must contain about 50 parts of resorcinol resin precondensate 
(B1) in order to have practically useful degrees of water resistance and 
boiling resistance, the precondensate (B1) contents required in the 
Examples of the present invention are only one-half or less. Furthermore, 
it will be apparent from Table 1 and Table 2 that the larger the 
proportion of resorcinol resin precondensate (B1) is, the lower is the 
initial bond strength. However, the adhesive compositions according to the 
present invention ensure excellent resistance of the bond to water and 
boiling even if the proportion of resorcinol resin precondensate (B1) is 
small and, moreover, for the very reason that the precondensate content is 
low, there is no decrease in initial bond strength. Thus, the adhesive 
compositions according to the present invention are not only excellent in 
resistance of the bond to water and boiling but also in initial bond 
strength. Furthermore, as will be apparent from Examples 7 to 11, the 
water resistance decreases as the amount of HMTA becomes excessive 
relative to the emulsion (A1). Therefore, the proportion of HMTA is 
preferably within the range of 2 to 30 parts to each 100 parts of 
(A1)+(B1). 
Referring, now, to the values of bond strength after repeated boiling in 
Tables 1 and 2, the relation between bond strength after repeated boiling 
and amount of resorcinol resin precondensate (B1) was plotted for 
reference. The plots are given in FIG. 1. 
In FIG. 1, the curve (1) represents the data on Examples 1 to 6 and the 
curve (2) represents the data on Comparative Examples 1 to 5. According to 
FIG. 1, the proportion of (B1) at which the bond strength after repeated 
boiling reaches a point of saturation is (B1)/(A1)=20/100 for Examples of 
the present invention, while the corresponding proportion for Comparative 
Examples is (B1)/(X)=60/100. Therefore, using the adhesive composition of 
the present invention (Example 3) and the conventional adhesive 
composition (Comparative Example 6), which corresponded to the 
above-mentioned points of saturation, the relation between pressure time 
and initial bond strength was investigated. 
[Bond strength test 2] 
First, by the same procedure as used in testing the initial bond strength 
in Bond strength test 1, the pull-apart strengths of the above adhesive 
compositions were measured. However, the varying pressure times of 10, 20 
and 30 minutes were used. 
Then, using birch blocks as adherends, each of the above adhesive 
compositions was applied at a spread of about 300 g/m.sup.2 and after a 
pressure time of 20, 40, 60 or 80 minutes, the compression shear strength 
of each test piece was immediately measured in accordance with JIS K 6804. 
The results are shown in Table 3. 
TABLE 3 
______________________________________ 
Pull-apart 
strength (kg/4 
Compression shear 
cm) Pressure time 
strength (kg/cm.sup.2) 
(min.) Pressure time (min.) 
Mixing ratio 10 20 30 20 40 60 80 
______________________________________ 
Example 
(A1)/(B1)/ 15 24 28* 70 90 110 140 
3 HMTA = 
100/20/12 
Compar. 
(X)/(B1)/ 6 11 15 30 50 75 90 
Example 
HMTA = 
6 100/60/16 
______________________________________ 
*The test piece was destroyed. 
It is apparent from the data given in Table 3 that as compared with 
Comparative Example 6, Example 3 of the present invention develops a 
necessary bond strength more than twice as early. This means that the 
pressure time necessary for a given bond strength is shorter and obviously 
this is a great practical advantage. 
EXAMPLES 12-21 
In the preparation of emulsion (A1) according to Example 1, the AAc monomer 
acetoacetoxyethyl acrylate was used in a varying proportion of 0.2, 0.4, 
2, 10 or 20% based on total monomer and 100 parts of each emulsion so 
obtained was mixed with 20 parts of (B1) and 12 parts of HMTA to prepare 
an adhesive composition. Using these adhesive compositions, the bond 
strength test described in Example 1 was performed. The results are shown 
in Table 4. 
Further, in the preparation of emulsion (A1) according to Example 1, 
GOHSEFIMER Z-100, an AAcPVA polymer, was used in a varying proportion of 
0.2, 1, 5, 11, 20 or 25 parts, and 100 parts of each resulting emulsion 
was mixed with 20 parts of (B1) and 12 parts of HMTA to prepare an 
adhesive composition. Using the adhesive compositions thus obtained, the 
bond strength test described in Example 1 was performed. The results are 
shown in Table 4. 
TABLE 4 
__________________________________________________________________________ 
Bond strength 
Bond Bond 
after standing 
strength after 
strength 
Bond strength 
in normal 
immersion 
after 
after repeated 
Example 
Amount condition 
in water 
boiling 
boiling 
__________________________________________________________________________ 
12 AAc monomer, 0.2 (wt %) 
200 60 30 50 
13 0.4 200 80 60 80 
14 2 200 100 80 90 
15 10 210 120 90 110 
16 20 (*1) 200 100 80 100 
17 Z-100 (*2), 0.2 (part) 
200 100 60 60 
18 1 200 110 90 100 
19 5 200 100 80 100 
20 11 210 120 90 110 
21 20 210 100 70 70 
22 25 210 90 40 50 
__________________________________________________________________________ 
(*1): The polymerizability was more or less poor. 
(*2): GOHSEFIMERZ-100 
It is apparent from Examples 12 to 16 in Table 4 that when the 
copolymerizing amount of AAc monomer is less than 0.4 percent, the bond 
strength after boiling and that after repeated boiling are considerably 
sacrificed. In regard to Examples 17 to 22, it is clear that when the 
proportion of GOHSEFIMER Z-100, an AAcPVA polymer, exceeds 20 parts, the 
bond strength after boiling and that after repeated boiling tend to 
decrease. It was also found that polymerizability is sacrificed when the 
amount of AAcPVA polymer is less than 0.2 part. In this connection, the 
use of emulsifying agents was attempted in hopes of improving the 
polymerizability but such attempts failed in effect, for the water 
resistance of adhesive compositions deteriorated. 
EXAMPLES 23-27 
A separable flask fitted with a stirrer, a reflux condenser, dropping 
funnel and thermometer was filled with 150 parts of water, 8 parts of an 
AAcPVA polymer (Nippon Synthetic Chemical Industry, GOHSEFIMER Z-200; 4.5 
mole % acetoacetylated PVA with a degree of polymerization of 1700 and a 
saponification degree of 99 mole %, 2 parts of another AAcPVA polymer 
(Nippon Synthetic Chemical Industry, GOHSEFIMER Z-100) and 10 parts of 
vinyl acetate, and the internal temperature of the flask was increased to 
60.degree. C. with stirring. In this procedure, with the atmosphere in the 
flask being replaced with nitrogen gas, 3 parts of a 10% aqueous solution 
of tartaric acid and 5 parts of a 10% aqueous solution of hydrogen 
peroxide were added as the polymerization catalyst. The prepolymerization 
was conducted for 30 minutes, at the end of which time 88 parts of vinyl 
acetate and 2 parts of acetoacetoxyethyl acrylate, an AAc monomer, were 
added in portions over a period of 3 hours. The mixture was ripened at 
75.degree. C. for 1 hour to give a vinyl acetate-AAc monomer copolymer 
emulsion (A2) containing the AAcPVA polymers. 
On the other hand, a separable flask fitted with a stirrer, reflux 
condenser, dropping funnel and thermometer was filled with 210 parts of 
resorcinol, 10 parts of phenol, 107 parts of 37% formaldehyde and 1 part 
of oxalic acid and the internal temperature of the flask was increased to 
95.degree. C. with stirring. The mixture was heated at that temperature 
for 1 hour and after cooling, the reaction mixture was adjusted to pH 8.2 
with 30% NaOH to give a resorcinol resin precondensate (B2). 
Separately, as another resorcinol resin precondensate (B3), an 
alkylresorcinol/aldehyde precondensate (Nagoya Yukagaku Kogyo, DFK-INB) 
was provided. 
The above emulsion (A2) and resorcinol resin precondensates (B2) and (B3) 
were mixed with the emulsion (A1) and resorcinol resin precondensate (B1) 
used in Example 1 in the combinations shown in Table 5 to give different 
adhesive compositions. The mixing ratio, on a nonvolatile matter basis, of 
said emulsion, resorcinol resin precondensate and HMTA was 100:20:12. 
Using these adhesive compositions of Examples 23 to 27, the bond strength 
test described in Example 1 was carried out. The results are shown in 
Table 5. 
TABLE 5 
______________________________________ 
Example 
23 24 25 26 27 
______________________________________ 
Emulsion A1 A1 A2 A2 A2 
Resorcinol resin 
B2 B3 B1 B2 B3 
precondensate 
Odor Odor- Odor- Odor- Odor- Odor- 
less less less less less 
Property of mixture 
Good Good Good Good Good 
Bond strength after 
200 200 200 190 210 
normal standing 
Bond strength after 
90 100 110 100 100 
immersion in water 
Bond strength 
80 80 80 70 80 
after boiling 
Bond strength after 
100 90 100 90 100 
repeated boiling 
______________________________________ 
It is apparent from the data in Table 5 that an alkylresorcinol-aldehyde 
precondensate or a precondensate of resorcinol and phenol with aldehyde 
can also be used successfully as said resorcinol resin precondensate.