Primer composition

There is disclosed a primer composition comprising PA0 [A] a reaction product of: PA1 (1) a hydroxyl group-containing organic compound composed of; PA2 (a) an epoxy group-containing alcohol represented by the general formula [I]: ##STR1## wherein, R.sup.1 is a hydrocarbon group having 1 to 15 carbon atoms, or an organic group in which the same or different hydrocarbon groups are bonded to each other by an ether bond or an ester bond; and each of m and n is a value of 1 or more; and PA2 (b) a hydroxyl group-containing (meth)acrylate represented by the formula [II]: EQU (CH.sub.2 .dbd.CR.sup.2 COO).sub.a R.sup.3 [II] PA2 wherein R.sup.2 is a hydrogen atom or a methyl group; R.sup.3 is a substituted or unsubstituted hydrocarbon group, or a group in which the same or different hydrocarbon groups are bonded to each other by ether bond or the ester bond, the R.sup.3 being a-valent and having at least one hydroxyl group; and a is an integer of 1 to 3; PA2 an amount of active hydrogen atoms included in the aforesaid (a) being 25 to 75% with respect to the total amount of active hydrogen atoms included in the aforesaid (1), and PA1 (2) a polyisocyanate including 70 to 100% of the theoretical amount of isocyanato groups which will react with the total amount of the active hydrogen atoms included in the aforesaid (1); PA0 [B] an amino group-containing alkoxysilane or its partially hydrolyzed condensate having 0.5 to 1.5 amino active hydrogen atoms per epoxy group included in the aforesaid (1)(a); and PA0 [C] a diluent.

BACKGROUND OF THE INVENTION 
This invention relates to a primer composition, more specifically to a 
primer composition which permits providing extremely good adhesion 
properties between the primer composition and each of a glass plate and an 
adhesive by previously applying the primer composition to the glass plate, 
when joining the glass plates is carried out with the adhesive. 
Heretofore, as the primers used in causing the glasses to adhere to each 
other, there are known, for example, organic silicon compounds, i.e. 
silane coupling agents and their mixtures, which have carbon functional 
groups such as vinyl groups, amino groups, glycidoxy groups, methacyloxy 
groups and mercapto groups and in which silicon functional groups such as 
alkoxy groups, alkoxy-alkoxy groups and acetoxy groups are directly bonded 
to silicon atoms (e.g., Japanese Provisional Patent Publication No. 
65232/1973). Although being excellent in the adhesion properties to the 
glass, these silane coupling agents are insufficient in an affinity for 
adhesive layers, depending upon kinds of adhesives. Therefore, they have 
the problems that a peel-off phenomenon occurs at the interfacial layer 
between the adhesive layer and the primer layer. 
Further, another kind of primer is extensively known in which an epoxy 
resin and an amino group-containing alkoxysilane are employed together. 
However, such a primer has the drawback that it can not provide a 
sufficient adhesive strength, depending upon certain kinds of adhesives. 
Furthermore, Japanese Provisional Patent Publication No. 120626/1983 
discloses an active energy ray curing composition a film of which is 
formed on the surface of a substrate by the irradiation of active energy 
rays such as ultraviolet rays, a main component of the composition being 
an urethane polyacrylate obtained by the reaction of a hydroxyl 
group-containing epoxy compound which contains an aromatic hydrocarbon 
group and an ether bond or contains an aromatic, an alicyclic or an 
aliphatic hydrocarbon group and an ester bond in its molecular and which 
has a hydroxyl group as a side chain and an epoxy ring at a chain end; a 
polyisocyanate; and a hydroxyl group-containing (meth)acrylate. Such a 
composition just mentioned has the advantage that a treatment can be 
carried out in the absence of any solvent, but the adhesion of this 
composition to the substrate is not satisfactory, since it is dependent 
upon an amount of unreacted epoxy groups. Particularly, such a composition 
has the fault that its heat-resistant adhesion to the glass plate is poor. 
SUMMARY OF THE INVENTION 
Accordingly, an object of this invention is to provide a primer composition 
by which the above-mentioned problems are overcome and an excellent 
adhesion is established between the primer composition and each of the 
glass plate and the adhesive, when it is used in manufacturing glass-glass 
laminates or glass-polycarbonate laminates. 
The inventors of this invention have intensively conducted researches into 
primer composition which are pretreatment agents for glasses used in 
preparing the glass-glass laminates or the glass-polycarbonate laminates 
by the use of a variety of adhesives, with the aim of improving the 
affinity of primer layers for adhesive layers. As a result, it has been 
found that on using a composition in which an epoxyurethane (meth)acrylate 
is blended with an amino group-containing alkoxysilane or its partially 
hydrolyzed condensate, (meth)acrylic double bonds present in the primer 
composition are reacted with double bonds present in the used adhesive, 
when the adhesive is cured by a low-temperature heating, ultraviolet rays 
or the like, so that a good adhesion can be obtained, and thus this 
invention has now been achieved. 
That is to say, the primer composition of this invention is characterized 
by comprising 
[A] a reaction product of: 
(1) a hydroxyl group-containing organic compound composed of; 
(a) an epoxy group-containing alcohol represented by the general formula 
[I]: 
##STR2## 
wherein, R.sup.1 is a hydrocarbon group having 1 to 15 carbon atoms, or 
an organic group in which the same or different hydrocarbon groups are 
bonded to each other by an ether bond or an ester bond; and each of m and 
n is a value of 1 or more; and 
(b) a hydroxyl group-containing (meth)acrylate represented by the formula 
[II]: 
EQU (CH.sub.2 =CR.sup.2 COO).sub.a R.sup.3 [II] 
wherein R.sup.2 is a hydrogen atom or a methyl group; R.sup.3 is a 
substituted or unsubstituted hydrocarbon group, or a group in which the 
same or different hydrocarbon groups are bonded to each other by ether 
bond or the ester bond, the R.sup.3 being a-valent and having at least one 
hydroxyl group; and a is an integer of 1 to 3; 
an amount of active hydrogen atoms included in the aforesaid (a) being 25 
to 75% with respect to the total amount of active hydrogen atoms included 
in the aforesaid (1); and 
(2) a polyisocyanate including 70 to 100% of the theoretical amount of 
isocyanato groups which will react with the total amount of the active 
hydrogen atoms included in the aforesaid (1); 
[B] an amino group-containing alkoxysilane or its partially hydrolyzed 
condensate having 0.5 to 1.5 amino active hydrogen atoms per epoxy group 
included in the aforesaid (1)(a); and 
[C] a diluent. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In the following, this invention will be further described in detail. 
The epoxy group-containing alcohol (1)(a) serves to give the epoxy groups 
to the reaction product [A] and to thereby provide the composition with 
excellent adhesion properties to both the glass plate and the adhesive 
layer. In the general formula [I], R.sup.1 represents a hydrocarbon group 
having 1 to 15 carbon atoms or an organic group in which the hydrocarbon 
groups are bonded to each other by an ether bond or an ester bond. Such 
hydrocarbon groups may be aromatic or aliphatic, and their examples 
include a hydroxyethyl group, a 2,3-dihydroxypropyl group, a 
2,2-dimethylolbutyl group, a trimethylolethyl group, a 
2-ethyl-2-methylolpropylene group, a 2,2-dimethylolpropylene group, a 
diglycerol group, a sorbitol group, and groups represented by the 
following formulae: 
##STR3## 
Further, in the formula, each of m and n is an integer of 1 or more. 
Examples of such epoxy group-containing alcohols include, in addition to 
glycidol, ethylene glycol monoglycidyl ether, glycerin monoglycidyl ether, 
glycerin diglycidyl ether, trimethylolpropane monoglycidyl ether, 
trimethylolpropane diglycidyl ether, pentaerythritol monoglycidyl ether, 
pentaerythritol diglycidyl ether, pentaerythritol triglycidyl ether, 
diglycerol monoglycidyl ether, diglycerol diglycidyl ether, diglycerol 
triglycidyl ether, sorbitol triglycidyl ether, sorbitol tetraglycidyl 
ether, bisphenol A-diglycidyl ether-modified monoacrylate and compounds 
represented by the following formula: 
##STR4## 
of the recited alcohols, those in which (a) is a glycidol or R.sup.1 is an 
aliphatic hydrocarbon group are preferred, if it is desired that a cured 
primer film is elastic. 
The hydroxyl group-containing (meth)acrylate (1)(b) is the component which 
react with the polyisocyanate of (2) in order to provide the primer 
composition with a property of curing by heating at a relatively low 
temperature or a light irradiation. R.sup.3 in the general formula [II] 
represents an a-valent group having at least one hydroxyl group. This 
a-valent group is a substituted or unsubstituted hydrocarbon group having 
at least one hydroxyl group, or a group, having at least one hydroxyl 
group, in which the same or different hydrocarbon groups are bonded to 
each other by an ether bond or an ester bond. Examples of the R.sup.3 
include hydroxy group-containing hydrocarbon groups such as a hydroxyethyl 
group, a hydroxypropyl group, a glycerol group and a tetramethylolmethyne 
group; hydroxy group-containing hydrocarbon groups containing ether bond 
such as a hydroxybutoxypropoxy group and a hydroxyphenyloxypropoxy group; 
and hydroxy group-containing hydrocarbon groups containing ester bond such 
as a hydroxy-(meth)acryloyloxy group. These hydrocarbon groups may be 
substituted by halogen atoms or the like. If it is desired to provide the 
primer with physical properties, especially, elasticity after curing, the 
valence a is required to be within the range of 1 to 3. Examples of the 
hydroxyl group-containing (meth)acrylates include 2-hydroxyethyl acrylate, 
2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 
2-hydroxy-3-chloropropyl acrylate, 2-hydroxy-3-butoxypropyl acrylate, 
2-hydroxy-3-(meth)acryloyloxypropyl acrylate, 2-hydroxy-3-phenyloxy 
acrylate, 1,4-butylene glycol monoacrylate, glycerin monoacrylate, 
glycerin diacrylate, trimethylolpropane diacrylate, tetramethylolmethane 
triacrylate, triethylene glycol monoacrylate, polypropylene glycol 
monoacrylate and polycaprolactone glycol monoacrylate, and methacrylates 
corresponding to these acrylates. 
The hydroxyl group-containing organic compound (1) is composed of (a) and 
(b). A formulating proportion of (a) and (b) is such that an amount of the 
active hydrogen atoms of (a) is within the range of 25 to 75% with respect 
to the total amount of the active hydrogen atoms which are included in (1) 
and will react with the isocyanate of (2). When the formulating amount of 
(a) is less than 25%, any sufficient adhesive strength will not be 
obtained. On the other hand, when it is more than 75%, any satisfactory 
curing state will not be obtained in the case that the curing is carried 
out by heating at a relatively low temperature or the irradiation of 
ultraviolet rays. 
The polyisocyanate (2) can react with the hydroxyl groups of the 
above-mentioned (1)(a) and (b) in order to form an urethane acrylate 
oligomer [A] which is one of the main components of the primer 
composition. By way of such polyisocyanates, polyisocyanates used in usual 
urethanating reactions can be employed, but when an especially excellent 
light stability is required, it is preferred to employ a so-called 
non-yellowing type polyisocyanate. Examples of these polyisocyanates 
include tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene 
diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, 
hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, 
isophorone diisocyanate, methylene-bis(4-cyclohexyl isocyanate), 
##STR5## 
They may be employed alone or in any combination of two or more thereof. 
A formulating proportion of (2) is such that the amount of the isocyanate 
groups included in the polyisocyanate is within the range of 70 to 100%, 
preferably 80 to 100% of a theoretical amount of the isocyanate groups 
which react with the total amount of the active hydrogen atoms included in 
(1)(a) and (b). When the amount of the isocyanate groups is less than 70% 
of the above-mentioned theoretical amount, the unreacted hydroxyl 
group-containing organic compound which has no reactivity with the 
adhesive will be great in amount, so that the adhesive strength of the 
primer composition to the glass plate or the adhesive will be 
deteriorated. On the other hand, when it is more than 100% of the 
theoretical amount, the excessive isocyanate groups will remain and will 
bring about a reaction with the amino groups of (b) which should react 
with epoxy groups, with the result that the adhesive strength will be 
lowered and a stability of the primer composition will be reduced during a 
storage period. 
The above-mentioned component [A] can be prepared, for example, by adding 
dropwise (1)(a) and (b) separately or previously mixed (1)(a) and (b) to 
(2), or treating them in a temporary preparation manner, with stirring, 
but the way of adding dropwise (1)(a) and (b) separately is preferred, 
since the primer obtained in such a way will be excellent in the adhesive 
strength. The reaction for the manufacture of the component [A] can 
progress even at ambient temperature, but it is preferred to heat the 
materials up to 40.degree. to 80.degree. C. at the reaction. In this case, 
a reaction catalyst such as dibutyltin difatty acid salt and a 
polymerization inhibitor such as 2,4-di-tertbutyl-4-hydroxytoluene may be 
added thereto, if desired. Further, at the above-mentioned reaction, the 
diluent (C) not having active hydrogen atoms may be added thereto. After 
the completion of the dropwise addition, the stirring is further continued 
to bring the reaction to an end. The reaction time depends upon a kind of 
polyisocyanate but is preferably in the range of 1 to 30 hours. Moreover, 
in the case that the reaction catalyst is used, its amount depends upon a 
kind of polyisocyanate but is preferably in the range of 0 to 10% by 
weight, more preferably in the range of 0.001 to 2% by weight based on the 
total amount of component [A]. 
The amino group-containing alkoxysilane or its partially hydrolyzed 
condensate of [B] reacts with the epoxy groups of [A] in order to 
introduce a silicon-functionality into the primer composition and to 
thereby improve the adhesion to the glass plate. Examples of such amino 
group-containing alkoxysilanes or their partially hydrolyzed condensates 
include .gamma.-aminopropyltrimethoxysilane, 
.gamma.-aminopropyltriethoxysilane, 
N-(.beta.-aminoethyl)-.gamma.-aminopropyltrimethoxysilane, 
N-(.beta.-aminoethyl)-.gamma.-aminopropylmethyldimethoxysilane, 
.gamma.-anilinopropyltrimethoxysilane and their partially hydrolyzed 
condensates, but they are not limited. Of these compounds, the amino 
group-containing alkoxysilanes, particularly 
N-(.beta.-aminoethyl)-.gamma.-aminopropyltrimethoxysilane is preferred, 
since a good adhesion to the glass plate and the adhesive is obtained 
thereby. 
A formulating amount of [B] is such that the number of amino active 
hydrogen atoms included in [B] is 0.5 to 1.5, preferably, 0.8 to 1.2 per 
epoxy group included in (1)(a). When the number of the amino active 
hydrogen atoms is less than 0.5, a good adhesion to the glass plate and 
the adhesive can not be obtained; when the number is more than 1.5, its 
excess will be in vain, because the adhesion to the glass plate and the 
adhesive will not be improved in proportion to the number of the added 
amino active hydrogen atoms. 
The primer composition of this invention is substantially composed of 
components [A] and [B], but for the purpose of lowering a viscosity of the 
composition to facilitate its application work, the diluent of [C] is 
further added thereto. Such a diluent may be a reactive material having 
functional groups which will bring about a reaction with the 
above-mentioned component [A] or [B], or a material having no functional 
groups. Examples of the diluents of having no functional groups include 
organic solvents, i.e., aromatic hydrocarbons such as toluene and xylene; 
alcohols such as methanol, ethanol, isopropanol and butanol; alcohol 
ethers such as ethylene glycol monomethyl ether and ethylene glycol 
monoethyl ether as well as their acetic esters; ethers such as diethyl 
ether and tetrahydrofuran; esters such as ethyl acetate, propyl acetate 
and butyl acetate; ketones such as acetone, methyl ethyl ketone, methyl 
isobutyl ketone, cyclohexanone and isophorone; chlorinated hydrocarbons 
such as trichloroethylene, tetrachloroethylene and 1,1,1-trichloroethane; 
and polar solvents such as dimethylformamide and dimethylsulfoxide. They 
may be used alone or in the form of a mixture thereof. Further, examples 
of the reactive diluents include acrylates such as the hydroxyl 
group-containing (meth)acrylates usable as (1)(b), 2-ethylhexyl acrylate, 
propylene glycol diacrylate, butylene glycol diacrylate, 1,4-butanediol 
diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, 
butoxyethylene glycol acrylate, tetrahydrofurfuryl acrylate, cyclohexyl 
acrylate, benzyl acrylate, ethylcarbitol acrylate, butoxyethyl acrylate, 
butoxydiethylene glycol monoacrylate and glycidyl acrylate; methacrylates 
corresponding to the above-mentioned acrylates; (meth)acrylic compounds 
having no hydroxyl groups such as (meth)acrylate oligomers; and vinyl 
compounds such as N-vinyl-2-pyrrolidone. 
In the case that the diluent having the functional groups capable of 
reacting with the isocyanate groups is used in this invention, the diluent 
is to be added after the synthesis of the component [A]. When the used 
diluent has no functional groups which can react with the isocyanate 
groups, it may be added at or after the synthesis of the component [A]. 
The component [C] is blended with the primer composition in such an amount 
that it leads to such a viscosity as to make the application work 
possible. 
In order to facilitate the application work, the primer composition of this 
invention has a viscosity of, preferably, 10,000 cP or less, more 
preferably, 1,000 cP or less at 25.degree. C. When the viscosity is in 
excess of 10,000 cP, it will be difficult to apply it on a substrate in a 
thin state. 
For the sake of the improvement in weathering resistance, the primer 
composition of this invention may further include a known ultraviolet-ray 
absorber, antioxidant, age resister and/or the like. 
The primer composition of this invention has hydroxyl groups, alkoxysilyl 
groups and acryloyl groups as functional groups, and either the epoxy 
groups included in (1)(a) or the amino groups included in [B] further 
remain in the primer composition in compliance with a molar ratio of their 
groups. Thus, to begin with, the primer composition of this invention 
carries out curing at a first step in the range of ambient temperature to 
150.degree. C. after its application on the glass plate, and the 
above-mentioned functional groups except the acryloyl groups 
simultaneously act on silanol groups on the surface of the glass plate in 
order to form a primer layer thereon which is excellent in an adhesive 
strength and is strong. The adhesive including a polymerization initiator 
and having double bonds is then filled or applied thereonto in order to 
allow the acryloyl groups in the primer to react with the double bonds of 
the adhesive, so that the curing of the primer at a second step is carried 
out together with the curing of the adhesive. At this time, in order to 
carry out the curing of the primer at a relatively low temperature for a 
short period of time, and for the purpose of obtaining an excellent 
adhesive strength, it is preferred to previously add the polymerization 
initiator to the primer composition. As the polymerization initiator, a 
thermal polymerization initiator and a photopolymerization initiator may 
be used. Particularly, in the case that the material to be applied and the 
adhesive must not be heated, or in the case that the curing should be 
accomplished in a short time, it is preferred that the photopolymerization 
initiator is employed and the curing is achieved by the irradiation of 
ultraviolet rays. Examples of the photopolymerization initiators include 
benzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 
acetophenone, benzoin, benzoin ethyl ether, benzoin n-propyl ether, 
benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, 
benzyl, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one, 
2-hydroxy-2-methyl-1-phenylpropane-1-one, benzyl sulfide, thioxanthone and 
2-chlorothioxanthone. 
The primer composition of this invention is first applied to the glass 
plate by means of, e.g., brushing or immersion and is then allowed to 
stand at ambient temperature or heated at a relatively low temperature in 
order to accomplish curing and to thereby form a primer layer thereon. 
Next, any of acrylic adhesives, epoxy adhesives, urethane adhesives and 
other various organic adhesives having double bonds is applied thereto or 
filled and is then cured by heating, ultraviolet rays irradiation or 
electron beams irradiation to prepare a laminated product excellent in the 
adhesion to the glass and the adhesive. 
The reason why the excellent adhesive strength can be obtained by using the 
primer composition of this invention is that hydroxyl groups produced by 
the reaction of the epoxy groups of the epoxy urethane (meth)acrylate in 
the composition of this invention with the amino groups of the amino 
group-containing alkoxysilane or its partially hydrolyzed condensate and 
alkoxysilyl groups of the said silane act on silanol groups on the surface 
of the glass plate in order to provide a strong adhesive strength between 
the primer layer and the glass plate, and groups having unsaturated double 
bonds react with groups having unsaturated double bonds of the adhesive in 
order to further provide an excellent adhesive strength between the primer 
layer and the adhesive layer. 
The primer composition of this invention which is constituted as mentioned 
above is utilized as a primer when laminates are manufactured by applying 
the organic adhesive to the glass plates, and at this time, an excellent 
adhesion is given to both the glass plates and the adhesive. Further, the 
cured film thus obtained is more elastic than a cured film of a 
conventional epoxy resin primer, therefore it can sufficiently withstand 
shocks from the outside.

The present invention is illustrated by referring to the following 
Examples, in which parts represent all parts by weight. 
EXAMPLE 1 
In a reaction vessel, 388 parts of hydrogenated xylylenediisocyanate and 
0.83 part of 2,6-di-tert-butyl-4-hydroxytoluene were placed, and they were 
heated up to 85.degree. C. with stirring. To the resulting solution, there 
was added dropwise over 2 hours a mixture in which 0.42 part of dibutyltin 
dilaurate and 444 parts of 2-hydroxy-3-phenyloxypropyl acrylate were 
homogeneously dissolved. Next, a temperature of the mixture was raised up 
to 70.degree. C., and 4 hours' heating and stirring were carried out in 
order to prepare an urethane acrylate intermediate having 
2.40.times.10.sup.-3 mole/g of unreacted isocyanato groups. While the 
temperature was maintained at 70.degree. C., 738 parts of 
trimethylolpropane diglycidyl ether were further added thereto, and 
heating and stirring were then continued for 18 hours to obtain a reaction 
product in which a reaction ratio of the isocyanato groups was 98% or 
more. 
After diluted 300 parts of thus obtained reaction product with 700 parts of 
isopropyl alcohol, to the mixture were added 9 parts of 
1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one and 101 parts of 
N-(.beta.-aminoethyl)-.gamma.-aminopropyltrimethoxysilane. Then, they were 
uniformly mixed to prepare a primer composition A. 
EXAMPLE 2 
In a reaction vessel were placed, in the following order, a polyisocyanate, 
a polymerization inhibitor, a hydroxyl group-containing (meth)acrylate, a 
reaction catalyst, an epoxy group-containing alcohol, a diluent, a 
reaction initiator and an amino group-containing alkoxysilane shown in 
Tables 1 and 2 below, and the process of Example 1 was repeated under 
conditions described in Tables 1 and 2 in order to prepare primer 
compositions B to E. 
COMATIVE EXAMPLE 1 
A comparative composition D' was prepared by using the same reaction 
product that was employed for the preparation of the primer composition D, 
but not using the amino group-containing alkoxysilane. 
Table 1 shows blending proportions and reaction requirements for 
synthesizing reaction products, and Table 2 shows blending proportions for 
the preparation of primer compositions. 
TABLE 1 
______________________________________ 
Primer composition 
B C D E 
______________________________________ 
Polyisocyanate (parts) 
Isophorone diisocyanato 
520 520 
Trimethylol propane (1 mole) 
420 
hexamethylene diisocyanato 
(3 moles) adduct *1 
Trimethylhexamethylene 420 
diisocyanato 
Polymerization inhibitor (parts) 
2,6-Di-tert-butyl-4- 
0.83 0.74 0.83 0.88 
hydroxytoluene 
Hyroxyl group-containing 
acrylate or methacrylate 
(parts) 
2-Hydroxypropyl acrylate 
305 305 
Polypropylene glycol 339 
monomethacrylate *2 
Glycerin dimethacrylate 456 
Reaction catalyst (parts) 
Dibutyltin dilaurate 
0.40 0.37 0.40 0.44 
First step dropwise 
60 70 60 60 
addition temp. (.degree.C.) 
First step dropwise 
2 1 2 2 
addition time (hr.) 
First step reaction 
60 70 60 60 
temp. (.degree.C.) 
First step reaction 
1.5 5 2 3 
time (hr.) 
Unreacted isocyanato groups 
2.62 0.62 2.61 2.26 
of urethane acrylate 
intermediate (10.sup.-3 mole/g) 
Epoxy group-containing 
alcohol (parts) 
Glycidol 174 
Pentaerythritol diglycidyl 
78 
ether 
Glycerin-1,3-diglycidyl 479 
ether 
Sorbitol tetraglycidyl 406 
ether 
Second step dropwise 
60 60 
addition temp. (.degree.C.) 
Second step dropwise 
1 *3 1 *3 
addition time (hr.) 
Second step reaction 
65 75 65 70 
temp. (.degree.C.) 
Second step reaction 
.sup. 1.sup..5 
5 2 3 
time (hr.) 
Reaction ratio of 
&gt;98 &gt;98 &gt;98 &gt;98 
isocyanato group (%) 
______________________________________ 
Note: 
*1 An ethyl acetate solution including 70% of solids. 
*2 The average molecular weight was 360. 
*3 The total amount was added at once. 
TABLE 2 
______________________________________ 
Primer composition 
B C D D' E 
______________________________________ 
Reaction product (parts) 
400 500 400 400 400 
Diluent (parts) 
Ethyl acetate 600 600 
Butyl acetate 600 
Toluene 800 
Xylene 500 
Reaction initiator (parts) 
2-Hydroxy-2-methyl-1- 
8 10 10 10 6 
phenylpropane-1-one 
Amino group-containing 
alkoxysilane (parts) 
.gamma.-Aminopropyltriethoxysilane 
100 
N--(3-Aminoethyl)-.gamma.-amino- 
70 26 51 
propyltrimethoxysilane 
______________________________________ 
EXAMPLE 3 
The primer compositions A to E and the comparative composition D' prepared 
in Examples 1 and 2 were applied to each one surface of the glass plates 
having a square shape one side of which was 30 cm in length and having a 
thickness of 3 mm by the use of a brush, and heating was then carried out 
for a period of 30 minutes at 120.degree. C. in order to prepare primer 
films thereon. Each glass plate and a polycarbonate plate having the same 
plane size as the glass plate and having a thickness of 0.5 mm were fixed 
in parallel by using a spacer so that the primer-applied surface of the 
glass plate might confront the polycarbonate plate and so that both the 
plates might be spaced as much as 0.5 mm, and three sides of the fixed 
plates were sealed with a tape, leaving the one remaining side open. The 
fixed plates were oriented turning up the open sides thereof, and an 
urethane acrylate adhesive U1 modified with a polycarbonate and an amino 
group-containing alkoxysilane and an epoxyacrylate adhesive U2 were each 
fully injected through the open sides into the spaces between the fixed 
plates, least air bubbles should be introduced thereinto. The resulting 
laminates were subjected to ultraviolet rays irradiation for 5 seconds by 
the use of an ultraviolet rays irradiation device equipped with a 30 W/cm 
output high-pressure mercury vapor lamp, with the lamp spaced as much as 
15 cm from the glass plates thereof, in order to cure the adhesives, so 
that there were prepared glass plate-adhesive-polycarbonate plate 
laminates in which each primer layer was formed between the glass plate 
and the adhesive. 
COMATIVE EXAMPLE 2 
For comparison, glass plates which had not undergone the primer treatment 
were used to prepare similar laminates. For thus prepared laminates, 
appearance and adhesion state were observed, and shear adhesive strength 
and peel-off adhesive strength were measured. Furthermore, for laminates 
prepared in the same manner, the following tests were carried out. 
(1) Boiling test: Each laminate was caused to uprightly stand in warm water 
of 65.degree. C. and was immersed therein for 3 minutes, it was immersed 
immediately in boiling water at 100.degree. C. for 2 hours. Appearance and 
the adhered state of this laminate were compared with those at room 
temperature, and the shear adhesive strength and the peel-off adhesive 
strength were measured. 
(2) Heat resistance test: After the laminate was left to stand in a 
thermostat at 100.degree. C. for 2 hours, comparison and measurements were 
conducted similarly as in (1). 
These results are shown in Table 3 below. 
TABLE 3 
__________________________________________________________________________ 
No primer D' 
Adhe- (Compara- (Compar- 
sive 
Test item tive) A B C D ative) 
E 
__________________________________________________________________________ 
U1 Normal state: 
Appearance 
Color- 
Color- 
Color- 
Color- 
Color- 
Color- 
Color- 
less less less less less less less 
Adhered state 
Good Good Good Good Good Good Good 
Shear adhesive 
72 208* 198* 168* 210* 81 182* 
strength (kg/cm.sup.2) 
Peel-off adhesive 
3.0 9.0 8.8 6.2 9.3 5.3 7.7 
strength (kg/cm) 
Boiling test: 
Appearance 
Not Not Not Not Not ** Not 
changed 
changed 
changed 
changed 
changed changed 
Adhered state 
Not Not Not Not Not ** Not 
changed 
changed 
changed 
changed 
changed changed 
Shear adhesive 
36 82 69 48 94 44 66 
strength (kg/cm.sup.2) 
Peel-off adhesive 
0.9 3.5 2.2 1.4 3.6 1.1 1.8 
strength (kg/cm) 
Heat resistance test: 
Appearance 
Not Not Not Not Not ** Not 
changed 
changed 
changed 
changed 
changed changed 
Adhered state 
Not Not Not Not Not ** Not 
changed 
changed 
change 
changed 
changed changed 
Shear adhesion 
75 220* 201* 169* 216* 80 188* 
strength (kg/cm.sup.2) 
Peel-off adhesive 
3.2 10.3 9.1 6.6 9.5 5.4 7.2 
strength (kg/cm) 
U2 Normal state: 
Appearance 
Color- 
Color- 
Color- 
Color- 
Color- 
Color- 
Color- 
less less less less less less less 
Adhered state 
Good Good Good Good Good Good Good 
Shear adhesion 
19 52 50 46 56 24 52 
strength (kg/cm.sup.2) 
Peel-off adhesive 
0.8 2.2 2.7 2.9 3.7 1.2 3.3 
strength (kg/cm) 
__________________________________________________________________________ 
Note: 
*The glass plate was broken. 
**A partial peeloff occured between the glass plate and the primer layer. 
U1: The main component was synthesized from polycarbonate diol, bisphenol 
A, propylene oxide, 2hydroxypropyl acrylate, 2ethylhexyl acrylate and 
isophoron diisocyanate. 
U2: The main component was synthesized from bisphenol A, epichlorohydrin 
and acrylic acid. 
For the laminates in which the adhesive U2 was used, the boiling test and 
the heat resistance test were carried out, and it has been found that with 
regard to the laminates which had not undergone the primer treatment, the 
adhesive layers were peeled from the glass plates and the polycarbonate 
plates. On the contrary, with regard to the laminates which were treated 
with the primer compositions of this invention, the adhesives were fully 
kept adhering to the surfaces of the glass plates, though they were peeled 
from the polycarbonate plates. With regard to the laminates treated with 
the comparative primer composition D', the primer layers were partially 
peeled from the glass plates, as in the case of the laminates in which the 
adhesive U1 was employed. 
The above-mentioned results indicate that the laminates in which the primer 
compositions of this invention were used had an excellent adhesive 
strength.