Curable composition of oxyalkylene polymer

A curable composition comprising an oxyalkylene polymer having reactive silicon groups and at least one other oxyalkylene polymer which contains no reactive silicon group and is either one containing hydroxyl groups and having a number average molecular weight of not less than 4,000 or one having essentially no hydroxyl group. The curable composition gives a cured product which imparts improved drying properties to alkyd paints applied to the cured product.

FIELD OF THE INVENTION 
The present invention relates to a curable composition comprising (i) an 
oxyalkylene polymer having a silicon-containing group which has a hydroxyl 
or hydrolyzable group attached to silicon atom and which is crosslinkable 
through the formation of a siloxane linkage (hereinafter referred to as a 
reactive silicon group) and (ii) a specific oxyalkylene polymer. The 
curable composition is characterized by the property that alkyd resin 
paints applied thereto have an improved drying property. 
BACKGROUND OF THE INVENTION 
Oxyalkylene polymers having reactive silicon groups are curable by the 
moisture in the air at room temperature yielding a rubbery substance 
similar to a room temperature curable silicone rubber. The cured substance 
is useful as a sealant, adhesive and the like owing to its excellent 
elongation, tensile strength, and adhesion. 
One of the characteristics of polymers having reactive silicon groups is 
the advantage that, because the main chain is composed of an oxyalkylene 
polymer, almost all kinds of paints can be applied to the cured substance 
thereof. Incidentally, coating of silicone rubbers with paints is 
virtually impossible due to the water- and oil repellent nature of 
silicone rubber. 
Cured products of a composition of an oxyalkylene polymer having reactive 
silicon groups, however, sometimes cause insufficient drying (hardening) 
of coated alkyd paints, and therefore it is virtually impossible to coat 
the cured products with the paints. As a result, in such a case attempts 
to coat a cured sealant of oxyalkylene polymer that contains plasticizers 
with alkyd paints were almost given up. 
Alkyd paints, however, are used in various applications because of 
advantages in almost all respects over oil paints, e.g., by quick drying, 
hard and glossy films, excellent properties including adhesion, weathering 
resistance, oil resistance, and widely adjustable properties, through 
selection of the kinds of modifying drying oils, oil length and modes of 
modification. Therefore it is very advantageous for cured products of 
oxyalkylene polymers to be coated with alkyd paints. 
At the beginning, even the cause of the poor drying property was entirely 
unclear. However, the present inventors, after a diligent study of the 
cause, found that incorporation of low molecular weight plasticizers in a 
curable composition comprising an oxyalkylene polymer having reactive 
silicon groups impairs the drying property. Plasticizers are used where it 
is neccessary to lower the viscosity of the composition (to improve 
workability at the time of application) or to improve the tensile property 
of the cured substance. Since it is simple to use plasticizers for 
lowering viscosity or improving the tensile property, the present 
inventors, after searching for materials which do not impair the drying 
property of alkyd paints, found that the above problem is eased by the use 
of a high molecular weight plasticizer. 
Among high molecular weight plasticizers, oxyalkylene polymers are superior 
plasticizers since they are cheap and the cured products have excellent 
tensile properties at low temperature. 
The present inventors have examined various oxyalkylene polymers, and found 
that when a specific oxyalkylene polymer is used as a plasticizer for an 
oxyalkylene polymer having reactive silicon groups, the cured product has 
a highly improved drying property. 
SUMMARY OF THE INVENTION 
According to the present invention a curable composition is provided 
comprising (A) an oxyalkylene polymer having at least one 
silicon-containing group which has a hydroxyl or hydrolyzable group 
attached to a silicon atom and which is crosslinkable by forming a 
siloxane linkage, and (B) at least one polymer selected from the group 
consisting of (i) an oxyalkylene polymer containing hydroxyl group, and 
having a number average molecular weight of not less than 4,000 and (ii) 
an oxyalkylene polymer having substantially no hydroxyl group, said 
curable composition being characterized in that alkyd resin paints applied 
thereto have an improved drying property.

DETAILED DESCRIPTION OF THE INVENTION 
An oxyalkylene polymer having at least one reactive silicon group in its 
molecule [this polymer is hereinafter referred to as oxyalkylene polymer 
(A)] is used in the present invention. Examples of oxyalkylene polymer (A) 
are already disclosed in U.S. Pat. Nos. 3,971,751, 3,979,384 and 
4,323,488, JP-B-45-363l9, JP-B-46-12154 and JP-B-49-32673 (the term "JP-B" 
as used herein means an "examined Japanese patent publication") as well as 
JP-A-50-156599, JP-A-5l-7356l, JP-A-54-6096, JP-A-55-82l23, 
JP-A-55-123620, JP-A-55-125l21, JP-A-55-131022, JP-A-55-135l35, and 
JP-A-55-137l29, (the term "JP-A" as used herein means an "unexamined 
published Japanese patent application") incorporated herein by references. 
The molecular chain of the oxyalkylene polymer (A) preferably has a 
recurring unit that is represented essentially by the general formula: 
EQU --R.sup.1 --O-- 
where R.sup.1 is a substituted or unsubstituted divalent hydrocarbon group 
having 1 to 8 carbon atoms, preferably a hydrocarbon group having 3 or 4 
carbon atoms. 
Specific examples of R.sup.1 include: 
##STR1## 
and the like. 
The molecular chain of the oxyalkylene polymer may be composed of the same 
or different recurring units. A particularly preferred example of R.sup.1 
is 
##STR2## 
The molecular chain of oxyalkylene polymer (A) may contain recurring unit 
other than --R.sup.1 --O--. In such a case it is preferable that the sum 
of the recurring units --R.sup.1 --O-- in the oxyalkylene polymer (A) 
exceeds 60 wt %, and specifically exceeds 80 wt % of said polymer. 
The reactive silicon groups in oxyalkylene polymer (A) or the 
silicon-containing functional groups that are capable of crosslinking by 
forming siloxane bonds, are well known in the art and are characterized by 
their ability to crosslink even at room temperature. Typical examples of 
such reactive silicon functional groups are represented by general formula 
(I): 
##STR3## 
where R.sup.2 is a substituted or unsubstituted monovalent organic group 
having 1 to 20 carbon atoms which may be the same or different; X is a 
hydroxyl group or a hydrolyzable group; a is 0 or an integer of 1 or 2; b 
is 0 or an integer of 1, 2 or 3, with the proviso that 1.ltoreq.the sum of 
a and b, and preferably 1.ltoreq.the sum of a and b.ltoreq.4; and m is 0 
or an integer of 1 to 19, however, not all of the m units 
##STR4## 
are necessarily the same. 
Reactive silicon functional groups which are preferred for such reasons as 
economy are represented by general formula (II): 
##STR5## 
where R.sup.2, X and b are the same as defined above. 
Specific examples of the hydrolyzable group X in formula (I) or (II) 
include a halogen atom, a hydrogen atom, an alkoxy group, an acyloxy 
group, a ketoximate group, an amino group, an amido group, an aminooxy 
group, a mercapto group and an alkenyloxy group. Among these examples, 
alkoxy groups such as methoxy and ethoxy are preferred since they will 
undergo mold hydrolysis. 
Specific examples of R.sup.2 in formula (I) include alkyl groups having 1 
to 20 carbon atoms such as methyl and ethyl, cycloalkyl groups having 3 to 
20 carbon atoms such as cyclohexyl, aryl groups having 6 to 20 carbon 
atoms such as phenyl, and aralkyl groups having 7 to 20 carbon atoms such 
as benzyl. In formula (I) or (II), R.sup.2 may be a triorganosiloxy group 
represented by the following formula: 
EQU (R').sub.3 SiO-- 
where R' is a substituted or unsubstituted monovalent organic group, and 
preferably is a hydrocarbon group having 1 to 20 carbon atoms, such as a 
methyl group, phenyl group, etc., provided that the three R' are not 
necessarily the same. A particularly preferred example of R.sup.2 in 
formula (I) or (II) is methyl. 
In order to ensure satisfactory curability, the oxyalkylene polymer (A) 
preferably contains at least 1, more preferably at least 1.1, and most 
preferably 1.5 to 4, reactive silicon functional groups per molecule on 
the average. Such reactive silicon functional groups are preferably 
present at terminals of the molecular chain of the oxyalkylene polymer 
(A). 
The oxyalkylene polymer (A) has a number average molecular weight which 
preferably ranges from 3,000 to 30,000, more preferably from 5,000 to 
15,000. Oxyalkylene polymers (A) may be used either alone or in 
combination. 
The oxyalkylene polymer (A) may be prepared by performing an addition 
reaction between hydrosilyl compound such as a compound having a formula 
in which hydrogen is bonded to a group of general formula (I) and an 
oxyalkylene polymer having a group having olefinic unsaturation (olefin 
group) represented by general formula (III): 
##STR6## 
(where R.sup.3 is a hydrogen atom or a monovalent organic group having 1 
to 20 carbon atoms; R.sup.4 is a divalent organic group having 1 to 20 
carbon atoms; c is 0 or 1) in the presence of a catalyst made of a metal 
of group VIII such as platinum. 
Other methods for preparing the oxyalkylene polymer (A) are described 
below: 
(1) reacting a hydroxyl-terminated polyoxyalkylene with a polyisocyanate 
compound such as toluene diisocyanate to form an isocyanate-terminated 
alkylene oxide polymer, and subsequently reacting the terminal isocyanate 
group with a W group in a silicon compound represented by general formula 
(IV): 
##STR7## 
where W is an active hydrogen containing group selected from among a 
hydroxyl group, a carboxyl group, a mercapto group and an amino group 
(primary or secondary); and b, R.sup.2, R.sup.4 and X are each the same as 
defined above; 
(2) performing an addition reaction between an olefin group in an 
olefin-containing polyoxyalkylene represented by formula (III) and a 
mercapto group in a silicon compound of formula (IV) where W is a mercapto 
group; and 
(3) reacting a hydroxyl group in a hydroxyl-terminated polyoxyalkylene with 
a compound represented by general formula (V): 
##STR8## 
where R.sup.2, R.sup.4, X and b are each the same as defined above. It 
should be noted, however, that the oxyalkylene polymer (A) may be prepared 
by other methods. 
In the preparation of oxyalkylene polymer (A) part or all of the X groups 
in the reactive silicon group may be converted to other hydrolyzable 
groups or a hydroxyl group. If the X group is a halogen atom or hydrogen 
atom, it is preferably converted to an alkoxy, acyloxy, aminoxy, 
alkenyloxy, hydroxyl group or some other group. In formula (III), R.sup.3 
is a hydrogen atom or a substituted or unsubstituted monovalent organic 
group having 1 to 20 carbon atoms, and is preferably a hydrogen atom or a 
hydrocarbon group, with the former being particularly preferred. In 
formula (III), R.sup.4 is a divalent organic group having 1 to 20 carbon 
atoms and is preferably --R.sup.5 --, --R.sup.5 OR.sup.5 --, 
##STR9## 
(where R.sup.5 is a hydrocarbon group having 1 to 10 carbon atoms), with a 
methylene group being particularly preferred. The olefin-containing 
alkylene oxide polymer may be prepared by various methods, such as a 
method in which olefin groups are introduced into a hydroxyl-terminated 
polyoxyalkylene by using an ether, ester, urethane or carbonate linkage as 
disclosed in JP-A-54-6097 and a method in which an epoxy compound such as 
ethylene oxide or propylene oxide is polymerized with an olefin-containing 
epoxy compound such as allyl glycidyl ether producing an alkylene oxide 
polymer having an olefin group in a side chain. 
The above-mentioned oxyalkylene polymer (A) is used together with a 
specific oxyalkylene polymer (hereinafter referred to as oxyalkylene 
polymer (B)). The oxyalkylene Polymer (B) is used is to reduce the 
viscosity of the composition, to reduce the cost of the composition and to 
adjust properties of the composition such as hardness, modulus of 
elasticity, and the like, and also acts to improve the drying of alkyd 
paints applied to the cured product as compared with the case where low 
molecular weight plasticizers are combined with the oxyalkylene polymer 
(A). 
The oxyalkylene polymer (B) is at least one oxyalkylene polymer selected 
from the group consisting of (i) an oxyalkylene polymer containing a 
hydroxyl group and having a number average molecular weight of not less 
than 4,000 and (ii) an oxyalkylene polymer having essentially no hydroxyl 
groups. The oxyalkylene polymer (B) is used as a plasticizer, and 
therefore does not contain (unlike the oxyalkylene polymer (A)) a room 
temperature crosslinkable group such as a reactive silicon group. 
The oxyalkylene polymer (B) like the oxyalkylene polymer (A), contains, as 
monomer units constituting the main chain, not less than 60%, and 
preferably not less than 80% of monomer represented by --R.sup.1 --O--. As 
R.sup.1, preferred is 
##STR10## 
The number average molecular weight of the oxyalkylene polymer (B) (i) is 
required to be not less than 4,000, preferably not less than 4,500, and 
is, most preferably 5,000 to 15,000. When the number average molecular 
weight is less than 4,000 and the polymer has a hydroxyl group, drying of 
a paint film becomes worse when an alkyd paint is applied to the cured 
substance. 
Furthermore, a polymer containing not more than 10% of components having a 
number average molecular weight of 1,000 or less (ratios from the value 
obtained by GPC method, and the same hereinafter) is preferable from the 
standpoint of obtaining better drying property of the alkyd resin paint. A 
polymer containing not more than 5% of these components is particularly 
preferable as polymer (B) (i). 
As for the molecular weights of oxyalkylene polymer (B) (i), those having a 
narrow distribution of molecular weight, or having a small ratio of weight 
average molecular weight (Mw)/number average molecular weight(Mw) are 
preferred because of a lower amount of lower molecular weight components 
and, thereby, a better drying property of the alkyd paint to be applied. 
Preferred are those having an Mw/Mn of 2 or less, and, more preferably, 
not more than 1.5. 
Examples of oxyalkylene polymers (B) (i) include polyoxypropylene glycols 
which have either a molecular weight of not less than 4,000 and a narrow 
molecular weight distribution or a molecular weight of not less than 4,000 
and a small amount of components of molecular weight of 1,000 or less. A 
part of the hydroxyl groups in the polyoxypropylene glycols can be blocked 
by hydrocarbon groups such as alkyloxy, alkylphenyloxy, alkenyloxy, 
allyloxy, etc., or which are blocked through such linkages such as 
urethane, ester, urea, carbonate, etc. by hydrocarbon groups such as 
alkyl, aryl, alkenyl, etc. 
The oxyalkylene polymer (B) (ii) is a polymer which essentially has no 
hydroxyl groups. When a hydroxyl group is contained in the polymer, the 
drying property of alkyd paints applied on the cured product tends to be 
worsened. The drying property of the alkyd paint is further improved where 
the number average molecular weight of the oxyalkylene polymer (B) (ii) is 
large. Since oxyalkylene polymers are produced by an ionic polymerization 
of alkylene oxides, the polymers normally have hydroxyl groups, and 
terminal hydroxyl groups in particular. There are various methods for 
obtaining the oxyalkylene polymer (B) (ii) from an oxyalkylene polymer 
having hydroxyl groups. For example, utilizing the reactivity of the 
hydroxyl groups, not less than 90 mol%, or preferably not less than 95 mol 
% of the hydroxyl groups, are converted to groups other than a hydroxyl 
group by introducing substituted or unsubstituted hydrocarbon groups. 
Examples of the polymers having hydroxyl groups converted to other groups 
include (as mentioned hereinbefore) oxyalkylene polymers in which the 
terminal hydroxyl groups are blocked through such linkages as ether, 
urethane, ester, urea, carbonate, etc. by substituted or unsubstituted 
hydrocarbon groups including alkyl groups such as methyl, ethyl, propyl, 
chloromethyl benzyl, and glycidyl, aryl groups such as phenyl, tolyl and 
chlorophenyl; and alkenyl groups such as vinyl and allyl; said substituted 
or unsubstituted hydrocarbon groups being preferably C.sub.1 to C.sub.40 
hydrocarbon groups. However, oxyalkylene polymers other than these may be 
used so long as essentially no hydroxyl groups are contained therein. 
Of the above-mentioned oxyalkylene polymers (B) (ii), it is convenient to 
use oxyalkylene polymers having alkenyl groups, because these can be raw 
materials for the oxyalkylene polymer (A). 
Although the molecular weight of the oxyalkylene polymer (B) (ii) is not 
restricted, a desirable application of alkyd paints is obtained where the 
molecular weight of the oxyalkylene polymer (B) (ii) is not less than 
1,000. A molecular weight of not less than 4,000, particularly not less 
than 4,500 is more preferable, and most preferable is a molecular weight 
of 5,000 to 15,000. At the same time, the above description of the content 
of the components having a number average molecular weight of 1,000 or 
below and of the molecular weight distribution for the oxyalkylene polymer 
(B) (i) is also true of the oxyalkylene polymer (B) (ii) i.e., the lower 
the content of the components having a number average molecular weight of 
1,000 or below, the more desirable the polymer is, with a minimum Mw/Mn 
being particularly preferred. 
The oxyalkylene polymers (B) may be used alone or in combination. On the 
other hand, the oxyalkylene polymers (B) may be incorporated as a 
plasticizer in the stage of producing the oxyalkylene polymers (A). 
The preferred amount of the oxyalkylene polymer (B) used in the curable 
composition is, based on 100 parts of oxyalkylene polymer (A) (by weight 
and the same hereinafter), 10 to 500 parts, in particular 20 to 200. Where 
the amount is less than 10 parts, the plasticizing effect is so slight 
that a reduction of the modulus of elasticity and an increase in 
elongation are not practically realized, whereas an amount in excess of 
500 parts brings about a slow curing rate. 
The composition of the present invention may contain other additives such 
as curing promoters, fillers, etc. Examples of curing promoters usable in 
the present invention include organo-tin compounds, acidic esters of 
phosphoric acid, reaction products of acidic esters of phosphoric acid and 
amines, saturated or unsaturated multi-valent carboxylic acids or 
anhydrides thereof, organo-titanates, organo-aluminium compounds, 
organo-zirconium compounds and the like. 
Examples of organo-tin compounds include dibutyltin dilaurate, dioctyl-tin 
dimaleate, dibutyl-tin phthalate, tin octylate, dibutyl-tin methoxide. 
Acidic esters of phosphoric acid are phosphates containing 
##STR11## 
portion, e.g., acidic organo-phosphates represented by the formula 
##STR12## 
where d is 1 or 2; and R is a residue of an organic group. Examples of 
which include: 
##STR13## 
Examples of organo-titanates include titanates such as tetrabutyl titanate, 
tetraisopropyl titanate, and triethanol amine titanate. 
The amounts of these titanates used as curing promoter are preferably 0.1 
to 20 parts per 100 parts of the oxyalkylene polymer (A). 
Examples of fillers include heavy calcium carbonate, light calcium 
carbonate, hard calcium carbonate, kaolin, talc, silica, titanium dioxide, 
aluminium silicate, magnesium oxide, zinc oxide, carbon black, etc. 
Examples of other additives include antisagging agents such as hydrogenated 
castor oil, organo-bentonite, etc., colorants and antioxidants. 
Needless to say, in the composition of the present invention, low molecular 
weight plasticizers such as dioctyl phthalate may be used to the extent 
that the effect of the present invention is not hindered. 
The above-mentioned composition of the present invention can be used for 
applications which include adhesives, water repellent paints, sealants, 
molds, casting rubbers and foams. 
A typical composition as: a sealant for architectural use consists of 100 
parts of the oxyalkylene polymer (A), 10 to 300 parts of inorganic fillers 
such as calcium carbonate, talc, kaolin, etc. and, as necessary, suitable 
amounts of other ingredients which include pigments such as titanium 
dioxide, carbon black, etc., antioxidants such as ultraviolet absorbers, 
radical chain terminators, etc., and air drying compounds such as drying 
oils, synthetic drying oils, etc. The composition is sufficiently 
homogenized by milling in a kneader, paint roller, or the like. After 
application of the composition, exposure thereof to the moisture in the 
surrounding air causes the composition to quickly cure--i.e., curing in 
one hour to a few days, and provides a rubbery elastomer having excellent 
weathering resistance and elongation. 
The improvements over existing art brought about when the composition is 
used as a water repellent paint include higher resistance to blistering, 
peeling, etc., because of an excellent balance between rupture strength 
and elongation, durability and water resistance. 
For use as an adhesive, application as a structural adhesive is useful 
because of excellent bond strength of the composition, particularly, an 
excellent balance between peel-bond strength and shear-bond strength. 
When coating the cured substance of the composition of the present 
invention with alkyd paints, it is most desirable to apply the paints 
after the composition has almost completely cured. The advantages of doing 
so are, for example, ease of painting because the paint is applied to the 
cured substrate thus rendered suitable as a substrate, and the fact that 
the passage of water needed for curing the oxyalkylene polymer (A), which 
is interrupted by the paint film, is not necessary. However, the 
composition of the present invention may be coated with the alkyd paints 
when the composition becomes tack-free, i.e., the state where the surface 
layer has been solidified. 
The above-mentioned alkyd paints have no specific restrictions. The paints 
have as their main ingredients so-called oil modified alkyd resins 
obtained by modifying the condensates of polybasic acids (phthalic 
anhydride, maleic anhydride, etc.) and polyhydric alcohols (glycerine, 
pentaerithrytol, ethylene glycol, trimethylol ethane, etc.) with fatty 
oils or fatty acids (linseed oil, soybean oil, castor oil, safflower oil, 
etc.) and modified alkyd resins obtained by modifying the alkyd resins 
with other resins or vinyl monomers, or the like. The alkyd paints herein 
referred to include those useful for any type of application, for example, 
alkyd resin varnishes or alkyd resin enamels for rolling stock, aircraft 
and general industries, alkyd ready-mixed paints (or synthetic resin 
ready-mixed paints) for architecture, bridges and ships, and alkyd primers 
for automobiles, machinery, electric appliances and furniture. 
Particularly remarkable effects of the composition of the present 
invention are exerted on long-oil alkyd paints containing a large quantity 
of drying oil and used for general purposes. 
When coating a cured product of the oxyalkylene polymer (A) admixed with 
low molecular weight plasticizers, the principle hitherto adopted was that 
alkyd paints could not be used unless the cured substance was previously 
coated with paints other than alkyd paints (primers). This was because 
drying of alkyd paints directly coated on the cured substance was so 
retarded that the paint film remained tacky even after about one month's 
drying time. However, use of the composition of the present invention, 
even in a system of an oxyalkylene polymer (A) and plasticizers, enables 
an ordinary coating procedure to be used to form a normal alkyd paint film 
on the cured substance. 
Examples given below illustrate the composition of the present invention. 
SYNTHESIS EXAMPLE 1 
800 g of oxypropylene polymer having an average molecular weight of about 
8,000 having allyl ether groups introduced, to 97% of all the terminal 
thereof, was placed in a pressure proof reactor equipped with an agitator, 
and then 19 g of methyldimethoxysilane was added. Further, 0.34 ml of a 
catalyst solution comprising chloroplatinic acid (8.9 g of H.sub.2 
PtCl.sub.6.6H.sub.2 O dissolved in a solvent mixture of 18 ml of isopropyl 
alcohol and 160 ml of tetrahydrofuran) was added, and the mixture was 
reacted at 80.degree. C. for 6 hours. 
It was confirmed by IR spectrometry that hydrosilyl groups scarcely 
remained in the reaction solution. The result of quantitative analysis of 
reactive silicon group by NMR method indicated that an oxypropylene 
polymer having about 1.7 (CH.sub.3 O).sub.2 Si(CH.sub.3)CH.sub.2 CH.sub.2 
CH.sub.2 O-- groups per molecule at terminals thereof was obtained. 
EXAMPLES 1 to 5 AND COMATIVE EXAMPLES 1 to 2 
Compositions comprising the oxyalkylene polymer (A) obtained in Synthesis 
Example 1, oxyalkylene polymers (B), and the other components identified 
in Table 1 were converted into sheets of 3 mm thickness, which were cured 
for one day at room temperature. 
An alkyd paint (trademark: Rockcoat of Rock Paints, Ltd.) was applied onto 
the sheet, and the hardening state of the film was evaluated by touch with 
a finger after the lapse of days as shown in Table 1. The results are 
shown in Table 1. 
In Table 1, 1 to 5 in the column of the oxyalkylene polymer (B) denote the 
follow: 
(1): oxypropylene polymer having Mn=7,500, Mw/Mn=1.8, both ends composed of 
allyloxy group, with no hydroxyl group; 
(2): oxypropylene polymer having Mn=5,200, M.sub.w /M.sub.n =1.6, both ends 
composed of allyloxy group; 
(3): oxypropylene polymer having Mn=5,l00, Mw/Mn=1.1, 4% of components of 
no more than MW 1,000, ends composed of hydroxyl groups; 
(4): oxypropylene polymer having Mn=4,000, Mw/Mn=1.1, both ends composed of 
allyl ether; 
(5): oxypropylene polymer having Mn=2,400, Mw/Mn=1.1, both ends composed of 
allyl ether. 
Figures in the column of evaluation results indicate hardening degrees of 
alkyd paint films applied, The hardening degrees are: 
5: complete hardening; 
4: slight surface tack despite hardening of the film; 
3: slight adhesion of paint on the finger when the film is touched by 
finger; 
2: adhesion of paint on the finger despite partial hardening of the film; 
1: increase in viscosity in the paint film; 
0: no change in the paint film. 
The results in Table 1 clearly indicate that the use of an oxypropylene 
polymer whose terminal hydroxyl groups have been blocked as indicated in 
Examples 1, 2, 4 and 5 brings about better hardening of alkyd paints in 
comparison with the case where lower molecular weight plasticizers or 
oxypropylene polymers having hydroxyl groups are used. 
Example 3 indicates that the use of an oxypropylene whose molecular weight 
is not less than 4,000 brings about better hardening of alkyd paints in 
comparison with the case where a lower molecular weight polypropylene 
glycol is used. 
TABLE 1 
__________________________________________________________________________ 
Example Comparison 
1 2 3 4 5 1 2 
__________________________________________________________________________ 
Composition (parts) 
Oxypropylene polymer (A) 
100 100 100 100 100 100 100 
of Synthesis Example 1 
Oxyalkylene polymers (B) 
(1) 40 -- -- -- -- -- -- 
(2) -- 40 -- -- -- -- -- 
(3) -- -- 40 -- -- -- -- 
(4) -- -- -- 40 -- -- -- 
(5) -- -- -- -- 40 -- -- 
Oxypropylene polymer *1 
-- -- -- -- -- 40 -- 
Lower molecular weight 
-- -- -- -- -- -- 40 
plasticizer *2 
Calcium carbonate *3 
140 140 140 140 140 140 140 
Titanium dioxide *4 
20 20 20 20 20 20 20 
Antisagging agent *5 
2 2 2 2 2 2 2 
Aminosilane compound *6 
2 2 2 2 2 2 2 
Curing promoter *7 
2 2 2 2 2 2 2 
Evaluation results 
Hardening of alkyd paint 
after: 
one day 4 4 0 3 3 0 0 
3 days 5 4 2 4 3 1 0 
7 days 5 5 3 4 4 2 0 
&gt;12 days 5 5 5 5 5 3 1 
__________________________________________________________________________ 
Note: 
*1: polypropylene glycol having --Mn = 3,000, --Mw/--Mn = 1.1; 
*2: dioctylphthalate; 
*3: CCR of Shiraishi Kogyo Ltd.; 
*4: Rutile type titanium dioxide Trade mark: R820 of Ishihara Sangyo 
Kaisha, Ltd.: 
*5: Hydrogenated castor oil; 
*6: A1120 of Nihon Unicar Ltd.; 
*7: #918 of Sankyo Yukigoshei Ltd. 
While the invention has been described in detail and with reference to 
specific embodiments thereof, it will be apparent to one skilled in the 
art that various changes and modifications can be made therein without 
departing from the spirit and scope thereof.