Emulsified alkenylsuccinic acid sizing agent

An emulsified alkenylsuccinic acid sizing agent having a solid content of not less than 25% by weight is disclosed, which comprises a composition having not less than 25 parts by weight of alkenylsuccinic acid derived from the reaction product of a branched internal olefin of 12-18 carbon atoms with maleic anhydride, and being dispersed in water with an anionic polymer type dispersant or with an anionic polymer type dispersant and an emulsifier.

FIELD OF THE INVENTION 
The present invention relates to a novel alkenylsuccinic acid type of 
emulsified sizing agent which is stable in storage in high concentration, 
and produces remarkable efficiency in paper sizing. 
BACKGROUND OF THE INVENTION 
Saponification type (or solution type) rosin sizing agents have long been 
used in combination with aluminium sulfate as an internal paper sizing 
agent in acidic paper making. Such kinds of sizing agents are known to be 
less effective at a low addition ratio, and the effect is known to 
decrease at a high temperature or in a neutral pH region or in a closed 
water system. Emulsion type rosin sizing agents were developed to cancel 
such disadvantage of the saponification type rosin sizing agents. However, 
they are still less effective at a low addition ratio in sizing, and are 
not satisfactory. 
To offset the disadvantages of the rosin sizing agents, a product derived 
by alkali-saponification of alkenylsuccinic acid has recently come to be 
used as a sizing agent because of its sufficient effect at a low addition 
ratio (U.S. Pat. No. 4,514,544). However, these sizing agents still have a 
disadvantage that the sizing efficiency is low in high temperature paper 
making or at paper making at around a neutral pH region. 
Further, an emulsion type of alkenylsuccinic acid sizing agent is known 
which is derived by emulsifying alkenylsuccinic anhydride containing an 
emulsifier in a cationized starch solution or water at a low concentration 
of about 0.5 to 3% and is useful as a neutral paper sizing agent (U.S. 
Pat. No. 3,321,069). 
The mechanism of action of alkenylsuccinic anhydride in neutral paper 
making is based on direct reaction of an anhydride group with a hydroxyl 
group of pulp and the fixation thereof onto pulp fibers to produce a 
sizing effect. Accordingly, in conventional neutral paper making, 
alkenylsuccinic anhydride has necessarily been added in an anhydride form 
to a pulp slurry. The alkenylsuccinic anhydride is highly reactive to 
water. Therefore, if the alkenylsuccinic anhydride is preliminarily 
emulsified and dispersed in water, it reacts with water in a short time to 
lose the anhydride group, thereby losing its function as a neutral sizing 
agent, and furthermore causing coagulation, precipitation, or separation 
of the emulsion owing to the change of the emulsion state in a process of 
conversion of alkenylsuccinic anhydride to alkenylsuccinic acid. Thus, an 
alkenylsuccinic anhydride type emulsion sizing agent for neutral paper 
making is storable only for several hours in an aqueous dispersion state. 
Therefore, it cannot be supplied commercially as an emulsion concentrate, 
and has to be emulsified just before paper making by an emulsifying 
machine. Moreover, at an acidic region employing aluminium sulfate as a 
fixing agent, the sizing efficiency develops slowly and is low immediately 
after paper making. 
As described above, the insufficiency of the sizing effect of conventional 
alkenylsuccinic anhydride emulsions immediately after acidic paper making 
is considered to be due to the facts that the emulsion sizing agent is 
fixed in an unchanged acid anhydride form, undergoing slow reaction of the 
alkenylsuccinic anhydride with pulp in an acidic region, and long time is 
required in reaction of the alkenylsuccinic anhydride with water to form 
alkenylsuccinic acid to produce a sizing effect upon reaction with 
aluminum sulfate. Accordingly, if alkenylsuccinic acid preliminarily 
formed from alkenylsuccinic anhydride can be emulsified, rapid reaction 
thereof with aluminium sulfate and sufficient sizing effect are expected 
to be achieved. 
Alkenylsuccinic acids, which are highly hydrophilic, cannot readily be 
emulsified. Therefore it is extremely difficult with conventional 
techniques to prepare the emulsion of the alkenylsuccinic acid which is 
storable stably for a long time in a high concentration. As described 
above, when alkenylsuccinic anhydride is emulsified with a conventional 
technique, the anhydride reacts with water in the emulsion to form 
alkenylsuccinic acid, giving an alkenylsuccinic acid emulsion. In the 
process of conversion of alkenylsuccinic anhydride to alkenylsuccinic 
acid, however, the emulsion state changes, giving no stable emulsion of 
alkenylsuccinic acid. In other words, even though an emulsion of 
alkenylsuccinic anhydride can be prepared temporarily in a high 
concentration, the alkenylsuccinic anhydride reacts with water in the 
emulsion to change into alkenylsuccinic acid, causing simultaneously 
coagulation, precipitation or separation without keeping a stable emulsion 
state, so that a stable emulsion cannot be obtained which contains 
alkenylsuccinic acid in a high concentration. 
The inventors of the present invention made a comprehensive study to 
utilize the superior properties of alkenylsuccinic acid as a sizing agent 
in an emulsion type to solve the aforementioned problems. As a result, the 
present inventors have found that a suitably selected emulsifier and/or an 
anionic polymer type dispersant containing a proper monomer component 
and/or a hydrocarbon resin containing no acid group makes an emulsion 
extremely stable in storage and to produce excellent sizing efficiency in 
paper making even at a low addition ratio, at high temperature, and in 
about a neutral pH region, which could not be achieved by conventional 
saponified alkenylsuccinic acid type sizing agents, and completed the 
present invention. 
SUMMARY OF THE INVENTION 
The present invention intends to provide a novel sizing agent comprising 
alkenylsuccinic acid, which is free from the disadvantages of saponified 
alkenylsuccinic acid type sizing agents and alkenylsuccinic anhydride type 
emulsion sizing agents, and produces excellent sizing efficiency in paper 
making at high temperature over a broad pH range at a low addition ratio 
even immediately after the paper making, and has high storage stability at 
a high concentration. 
The present invention provides an emulsified alkenylsuccinic acid sizing 
agent having a solid content of not less than 25% by weight, comprising a 
composition having more than 25 parts by weight of alkenylsuccinic acid 
derived from reaction of a branched internal olefin of 12-18 carbons with 
maleic anhydride, and being dispersed in water by an emulsifier and/or an 
anionic polymer type dispersant. 
DETAILED DESCRIPTION OF THE INVENTION 
The sizing agent of the present invention having the aforementioned 
constitution may be prepared by any of known conventional emulsifying 
methods, among which inversion methods are applicable most simply. In one 
method, alkenylsuccinic acid and a hydrocarbon resins are melt-blended 
thoroughly, and thereto an emulsifier and/or a polymer type dispersant are 
added and mixed sufficiently. Then water is added dropwise with stirring 
to cause phase inversion, thereby giving readily a sizing agent of the 
present invention. 
In another inversion method, the whole or a portion of an emulsifier and/or 
a polymer type dispersant is dissolved in water instead of preliminarily 
to a composition having more than 25 parts by weight of alkenylsuccinic 
acid and the emulsification is conducted by phase inversion. 
Furthermore, by using a high-pressure emulsifying machine, a finely stable 
alkenylsuccinic acid emulsion can be provided. In this case, a composition 
having more than 50 parts by weight of alkenylsuccinic acid is 
melt-blended by heating, and thereto hot water and an emulsifier and/or a 
polymer type dispersant are added to conduct a preliminary emulsification 
using a homogenizer, then emulsification is conducted using a 
high-pressure emulsifying machine. 
Still another emulsifying method is naturally practicable also in which a 
composition having more than 25 parts by weight of alkenylsuccinic acid is 
dissolved in a water-insoluble organic solvent such as benzene and 
toluene, thereto water and an emulsifying agent and/or a polymer type 
dispersant are added, the mixture is emulsified by means of a homogenizer, 
a high-pressure emulsifying machine, and the like, and thereafter the 
organic solvent is distilled off. 
In the present invention, further stable sizing effect can be achieved by 
using a hydrocarbon type resin having no acid group. The mixing ratio is 
75 to 5 parts by weight of hydrocarbon type resin and 25 to 95 parts by 
weight of alkenylsuccinic acid. 
The alkenylsuccinic acid used in the present invention is prepared by 
reacting alkenylsuccinic anhydride with an equimolar amount of water. 
The alkenylsuccinic anhydride is prepared in a known method by addition 
reaction of maleic anhydride to an olefin. The olefin is desirably a 
branched internal olefin having 12 to 18 carbons in view of the sizing 
effect. Although an alkenylsuccinic acid derived from a linear olefin is 
less effective in sizing, it may be blended partially with the 
alkenylsuccinic acid derived from a branched olefin within the range that 
the effect of the present invention is not impaired. 
By using alkenylsuccinic anhydride in place of alkenylsuccinic acid, an 
aqueous emulsion containing alkenylsuccinic anhydride can be obtained in a 
similar emulsification method. In this emulsion, the alkenylsuccinic 
anhydride reacts with water in the emulsion to become alkenylsuccinic acid 
in one or two days. However, owing to coexistence of the hydrocarbon type 
resin of the present invention, the emulsion state does not change at all 
during the conversion of the alkenylsuccinic anhydride to the 
alkenylsuccinic acid, without causing coagulation, precipitation, nor 
separation, being different from the emulsion containing only the 
alkenylsuccinic anhydride. Thus the sizing agent of the present invention 
containing the alkenylsuccinic acid is obtained in a stable form. 
Thus, in a case where an alkenylsuccinic anhydride alone is emulsified, the 
addition of a hydrocarbon type resin is essential. In a case where an 
alkenylsuccinic acid is emulsified, however, the addition of a hydrocarbon 
type resin is not necessarily required. 
The hydrocarbon type resin employed in the present invention may have no 
acid group (e.g., carboxyl group), and is compatible with the 
alkenylsuccinic acid or the alkenylsuccinic anhydride. In view of 
improvement of emulsifiability of the alkenylsuccinic acid and improvement 
of emulsion stability, the preferable resin includes aromatic resins, 
aliphatic resins, and aromatic-aliphatic mixed petroleum resins which are 
produced by polymerizing a cracked petroleum fraction having a boiling 
point in the range of from 20.degree. to 280.degree. C. derived by thermal 
cracking of petroleum; aromatic methylene resins (e.g., benzyl groups are 
bridged with methylene groups) containing substantially no oxygen atom; 
and aromatic formaldehyde resins having aromatic rings bonded through 
methylene, ether, acetal, methylol or the like, prepared by reaction of an 
aromatic compound with formaldehyde in the presence of a catalyst. 
Although the hydrocarbon type resin employed in the present invention, 
which contains no acidic group, gives little sizing effect by itself, it 
serves to improve remarkably the emulsifiability and the emulsion 
stability when used mixedly with the alkenylsuccinic acid. The mixing 
ratio of the alkenylsuccinic acid and the hydrocarbon type resin, which 
are the main constituents of the sizing agent of the present invention, is 
25 to 95% by weight of the alkenylsuccinic acid and 75 to 5% by weight of 
the hydrocarbon type resin. If desired, other resinous material may be 
incorporated in the composition, such as rosin, and a modified rosin such 
as a reaction product of rosin with an .alpha.,.beta.-unsaturated 
polybasic acid, disproportionated rosin, polymerized rosin, hydrogenated 
rosin, a reaction product of rosin with formaldehyde, fatty acid, tall 
oil, wax, hydrocarbons and the like. In this case, the total proportion of 
the alkenylsuccinic acid and the hydrocarbon type resin is preferably not 
less than 50% by weight. If resinous substances other than the 
alkenylsuccinic acid and the hydrocarbon type resin are contained in an 
amount of 50% or more, the sizing efficiency falls undesirably. 
Preferable emulsifiers useful in the present invention include one or a 
mixture of two or more of anionic or nonionic emulsifiers. Such preferable 
emulsifiers include anionic surfactants such as alkylbenzenesulfonic acid 
salts, polyoxyethylne alkyl ether sulfuric acid ester salts, 
polyoxyethylene alkylphenyl ether sulfuric acid ester salts, 
polyoxyethylene aralkylphenyl ether sulfuric acid ester salts, alkyl ether 
sulfuric acid ester salts, polyoxyethylene alkyl ether phosphoric acid 
esters and salts thereof, polyoxyethylene alkylphenyl ether phosphoric 
acid esters and salts thereof, polyoxyethylene aralkylphenyl ether 
phosphoric acid esters and salts thereof and the like; nonionic 
surfactants such as polyoxyethylene alkyl ether, polyoxyethylene 
alkylphenyl ether, polyoxyethylene aralkylphenyl ether, sorbitan fatty 
acid ester, polyoxyethylenesorbitan fatty acid ester and the like. Among 
them, preferable are polyoxyethylene nonylphenyl ether phosphoric acid 
ester or polyoxyethylene nonylphenyl ether sulfuric acid ester salt. 
The preferable polymer type dispersants include anionic copolymers of a 
component (A) monomer for constituting a hydrophilic moiety and a 
component (B) monomer for constituting a hydrophobic moiety, or partial or 
complete saponified anionic matter thereof. The component (A) includes 
acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic 
acid, fumaric acid and the like. The component (B) includes styrene type 
monomers such as styrene, and .alpha.-methylstyrene; acrylate esters and 
methacrylate esters such as methyl acrylate, methyl methacrylate, ethyl 
acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 
(meth)acrylamide and acrylonitrile and the like; and mixtures of two more 
thereof. 
The copolymer (or polymer) of the polymer type dispersant contains the 
component (A) in a ratio of from 5 to 100% by weight, preferably from 20 
to 95% by weight, and the component (B) in a ratio of 95 to 0% by weight, 
preferably from 80 to 5% by weight, based on the total monomers. At the 
content of the component (A) of less than 5% by weight, dispersion effect 
is not achievable. The polymer type dispersant is synthesized by 
copolymerization according to a known emulsion polymerization or solution 
polymerization method. The partially or wholly saponified copolymer is 
derived by saponifying the resulting copolymer with an alkali such as 
sodium hydroxide and potassium hydroxide. The required saponification 
degree depends on the application field, and is not specially limited. The 
number average molecular weight of the anionic polymer type dispersant is 
not higher than 500,000, preferably in the range of from 10,000 to 
300,000. 
The amount of an emulsifier and/or a polymer type dispersant is 1 to 20 
parts by weight, preferably 3 to 10 parts by weight with respect to a 
composition having more than 25 parts by weight of alkenylsuccinic acid. 
In order to improve mechanical stability, an acrylamide type water-soluble 
polymer can be added to the resulting emulsion in an amount of 0 to 15 
parts by weight, preferably 5 to 10 parts by weight, with respect to an 
alkenylsuccinic acid or an alkenylsuccinic acid and hydrocarbon type 
resin. The acrylamide type water-soluble polymer includes, e.g., a wholly 
or partially saponified copolymer of (meth)acrylamide and (meth)acrylic 
acid, a wholly or partially saponified copolymer of (meth)acrylamide and 
(meth)acrylic acid, or a wholly or partially saponified copolymer of 
(meth)acrylamide and (meth)acrylic acid and styrene, each of the 
copolymers have a number average molecular weight of 100,000 to 600,000. 
When a solid content concentration of the sizing agent is 1 to 70% by 
weight, a stable emulsion can be obtained. However, when it is less than 
25% by weight, it is not practical in view of high transporting cost. The 
solid content concentration means components other than water in the 
sizing agent. 
The sizing agent of the present invention may be added to paper material in 
any step before the completion of the paper making in the same manner as 
in conventional rosin type sizing agents. For example, the sizing agent of 
the present invention is fixed onto pulp by adjusting the pH of pulp 
slurry to be about 4.0-7.0 by addition of aluminium sulfate before or 
after addition of the sizing agent in or after a beating step. The sizing 
agent of the present invention may be used in combination with a 
conventional sizing agent such as a rosin type sizing agent, a petroleum 
resin sizing agent, and the like in an arbitrary ratio. 
The amount to be used (amount of addition) of the sizing agent of the 
present invention, in internal sizing, is in the range of from 0.01 to 
5.0% by weight, preferably from 0.05 to 3.0% by weight based on the dry 
pulp weight. 
The present invention is described in more detail by reference to examples 
and comparative examples without limiting thereby the invention in any 
way. The term "parts" is based on weight unless otherwise mentioned. 
STORAGE STABILITY TEST 
Alkenylsuccinic acid type emulsion sizing agents prepared as described in 
Examples 1-20 and in Comparative examples 1, 3, 4 and 6, respectively, 
were taken in an amount of 25 g in a 50-ml glass bottle. The sizing agents 
were kept standing at room temperature (25.degree. C.). The stability was 
observed visually after one day, 7 days, and 60 days. Less stable sizing 
agents caused deposition or separation of an oily matter at the bottom of 
the bottle or the top of the liquid. Incidentally, the sizing agents of 
Comparative Examples 2 and 5 are not tested for the storage stability 
because they are not of emulsion types but of saponified types. 
The results are shown in Table 1. 
SIZING EFFICIENCY TEST 
Bleached kraft hardwood pulp was diluted with tap water to a pulp 
concentration of 2.5%, and was beaten by means of a beater to attain a 
Canadian freeness of about 450 ml. The resulting pulp slurry was diluted 
to a concentration of 2.0% by weight with tap water at a temperature of 
50.degree. C. With stirring, aluminum sulfate (in an amount of 1.0% by 
weight based on pulp) was added thereto. Subsequently, the slurry was 
diluted to a concentration of 0.5% by weight with water of pH 4.5 at 
50.degree. C., and one of the sizing agents of Examples 1-20 and 
Comparative Examples 1-6 was added thereto (in an amount of 0.3% by 
weight). Paper was made from the slurry by use of a TAPPI standard machine 
(the basis weight of the finished paper: 60 g/m.sup.2). The resulting wet 
paper was pressed and dried in a conventional manner. The obtained 
finished paper was tested for sizing efficiency immediately after drying 
and after conditioning for one day in a conditioning room at a temperature 
of 20.degree. C. and at a humidity of 65% RH by the Stockigt method 
according to JIS P 8122. 
For a high-pH paper making test, evaluation was also made by using aluminum 
sulfate in an amount of 0.7% by weight based on pulp, and dilution-water 
and paper-making-water of pH 6.0. In Examples 1-20 and Comparative 
Examples 4 and 6, the sizing agents were used 10 days after 
emulsification. In Comparative Example 3, the alkenylsuccinic anhydride 
emulsion sizing agent was used immediately after emulsification, since the 
emulsion was so poor in storage stability that the emulsion state could 
not be kept for 10 days after the emulsification. 
MECHANICAL STABILITY TEST 
Mechanical stability of the sizing agents of Examples 15 and 16 and 
Comparative Example 1 was conducted according to JIS K-6387. Specifically, 
in an apparatus (Maron testing machine) described in JIS K-6387, 50 g of 
the sizing agent which was diluted to 10% concentration was added and 
tested for 30 minutes with 10 kg loading, then the sludge occurrence was 
observed. The results are shown in Table 3. Example 15 provides less 
sludge as compared to Comparative Example 1. Example 16 in which 
acrylamide type soluble polymer was added provides no sludge. 
SYNTHESIS OF POLYMER TYPE DISPERSANT 
Synthesis Example 1 
A mixture of 30 parts of styrene, 30 parts of n-butyl acrylate, 40 parts of 
acrylic acid, 5 parts of isopropyl alcohol, 4 parts of polyoxyethylene 
distyrylphenyl ether sulfuric acid ester ammonium (polymerization degree 
of oxyethylene: 13), 1 part of polyoxyethylene octylphenyl ether 
(polymerization degree of oxyethylene: 15), 2 parts of ammonium persulfate 
and 600 parts of water was prepared. The mixture was stirred at 80.degree. 
C. for 3 hours to undergo polymerization. Subsequently, the mixture was 
cooled to 60.degree. C., and thereto 20 parts of 38.9% potassium hydroxide 
was added dropwise gradually. The mixture was further stirred at 
60.degree. C. for 30 minutes, and cooled to room temperature. The 
resulting styrene-acrylic acid type copolymer had a solid content of 15% 
and a saponification degree of 25%. The number-average molecular weight of 
the copolymer before the saponification was about 170,000. 
Synthesis Example 2 
A mixture of 35 parts of styrene, 30 parts of n-butyl acrylate, 35 parts of 
acrylic acid, 5 parts of isopropyl alcohol, 4 parts of polyoxyethylene 
oleylphenyl ether sulfuric acid ester ammonium (polymerization degree of 
oxyethylene: 15), 1 part of polyoxyethylene dodecylphenyl ether 
(polymerization degree of oxyethylene: 12), 2 parts of ammonium persulfate 
and 600 parts of water was prepared. The mixture was stirred at 80.degree. 
C. for 3 hours to undergo polymerization. Subsequently, the mixture was 
cooled to 60.degree. C., and thereto 40 parts of 48.5% sodium hydroxide 
was added dropwise gradually. The mixture was further stirred at 
60.degree. C. for 30 minutes, and cooled to room temperature. The 
resulting styrene-acrylic acid type copolymer had a solid content of 15% 
and a saponification degree of 100%. The number-average molecular weight 
of the copolymer before the saponification was about 160,000. 
Synthesis Example 3 
40 Parts of maleic anhydride was dissolved in 100 parts of isopropyl 
alcohol, and heated under a nitrogen stream to a refluxing temperature. 
Thereto a mixture of 60 parts of n-butyl acrylate, 1 part of 
azobisisobutyronitrile and 100 parts of isopropyl alcohol was added 
dropwise in 2 hours. The mixture was kept at that temperature for 2 hours. 
Then a mixture of 29 parts of sodium hydroxide and 520 parts of water was 
added thereto dropwise. The isopropyl alcohol was distilled off by heating 
the mixture to the boiling temperature. Water was added thereto to obtain 
an aqueous pale brown transparent solution having a solid content of 20%, 
a saponification degree of 90%, and the molecular weight of the polymer of 
about 10,000. 
Synthesis Example 4 
A mixture of 10 parts of stearyl methacrylate, 30 parts of n-butyl 
acrylate, 60 parts of acrylic acid, 5 parts of isopropyl alcohol, 5 parts 
of polyoxyethylene distyrylphenyl ether sulfuric acid ester ammonium 
(polymerization degree of oxyethylene: 13) and 790 parts of water was 
prepared. The mixture was heated to 70.degree. C. with stirring, upon 
which 10 ml of 10% ammonium persulfate was added thereto, and the mixture 
then further heated to 80.degree. C. to undergo polymerization for 2 
hours. Subsequently, the mixture was cooled to 60.degree. C., and 167 
parts of 20% sodium hydroxide was added dropwise gradually. The mixture 
was further stirred for 30 minutes, and cooled to room temperature. The 
resulting acrylic acid-methacrylic acid type copolymer had a solid content 
of 13% and a saponification degree of 100%. The number-average molecular 
weight of the copolymer before the saponification was about 100,000. 
Synthesis Example 5 
A mixture of 4 parts by weight of stearyl methacrylate, 7 parts of n-butyl 
acrylate, 89 parts of acrylic acid, 5 parts of 1% 2-mercaptoethanol and 5 
parts of polyoxyethylene dibutylphenyl ether sulfuric acid ester ammonium 
(polymerization degree of oxyethylene: 13) was prepared. The mixture was 
polymerized in the same manner as in Synthesis Example 4, and saponified 
with 148 parts of 20% sodium hydroxide to obtain a copolymer having a 
solid content of 12% and a saponification degree of 60%. The 
number-average molecular weight of the copolymer before the saponification 
was about 50,000 
Synthesis Example 6 
A mixture of 7 parts of n-butyl acrylate, 93 parts of acrylic acid, 10 
parts of 1% 2-mercaptoethanol and 25 parts of 20% sodium dodecylbenzene 
sulfonate was prepared. The mixture was polymerized in the same manner as 
in Synthesis Example 4, and saponified with 103 parts of 20% sodium 
hydroxide to obtain a copolymer having a solid content of 12% and a 
saponification degree of 40%. The number-average molecular weight of the 
copolymer before the saponification was about 20,000. 
Synthesis Example 7 
A mixture of 4 parts of stearyl methacrylate, 7 parts of n-butyl acrylate, 
75 parts of acrylic acid, 14 parts of acrylamide, 5 parts of 1% 
2-mercaptoethanol and 5 parts of polyoxyethylene distyrylphenyl ether 
sulfuric acid ester ammonium (polymerization degree of oxyethylene: 13) 
was prepared. The mixture was polymerized in the same manner as in 
Synthesis Example 4, and saponified with 242 parts of 20% sodium hydroxide 
to obtain a copolymer having a solid content of 14% and a saponification 
degree of 100%. The number-average molecular weight of the copolymer 
before the saponification was about 50,000. 
Synthesis Example 8 
A mixture of 4 parts of stearyl methacrylate, 15 parts of n-butyl acrylate, 
81 parts of acrylic acid, 5 parts of 2% 2-mercaptoethanol and 5 parts of 
polyoxyethylene distyrylphenyl ether sulfuric acid ester ammonium 
(polymerization degree of oxyethylene: 13) was prepared. The mixture was 
polymerized in the same manner as in Synthesis Example 4, and saponified 
with 226 parts of 20% sodium hydroxide to obtain a copolymer having a 
solid content of 13%, and saponification degree of 100%. The 
number-average molecular weight of the copolymer before the saponification 
was about 60,000.

EXAMPLE 1 
30 parts of an aromatic methylene resin (trade name: Oligotech 1400, made 
by Mitsubishi Oil Co., Ltd., number average molecular weight: 900) was 
mixed with 70 parts of an alkenylsuccinic anhydride derived from addition 
reaction of maleic anhydride to a propylene oligomer (having 18 carbons in 
average). Added thereto were 4 parts of polyoxyethylene nonylphenyl ether 
phosphoric acid ester (polymerization degree of oxyethylene: 17) and 3 
parts of polyoxyethylene nonylphenyl ether sulfuric acid ester ammonium 
(polymerization degree of oxyethylene: 4). Further thereto, water was 
gradually added to cause phase-inversion emulsification to prepare an 
oil-in-water type emulsion of a total solid content of 40% by weight. 
EXAMPLE 2 
30 parts of a commercial aromatic methylene resin (trade name: Oligotech 
1300, made by Mitsubishi Oil Co., Ltd., number average molecular weight: 
700) was mixed with 70 parts of an alkenylsuccinic anhydride derived from 
addition reaction of maleic anhydride to a propylene oligomer (having 15 
carbons in average). Added thereto was 8 parts of polyoxyethylene 
nonylphenyl ether phosphoric acid ester (polymerization degree of 
oxyethylene: 17). Further, 10 parts of aqueous 20% solution of a 
saponified product of a commercial styrene-maleic acid copolymer (Trade 
name: HASMA1100, made by Misawa Ceramic Chemical Co., Ltd.) of a 
saponification degree of 60% was added thereto. Water was gradually added 
to cause phase-inversion emulsification to prepare an oil-in-water type 
emulsion of a total solid content of 45% by weight. 
EXAMPLE 3 
20 Parts of a commercial aromatic methylene resin (trade name: Oligotech 
1300, made by Mitsubishi Oil Co., Ltd., number average molecular weight: 
700) was mixed with 80 parts of an alkenylsuccinic anhydride derived from 
addition reaction of maleic anhydride to a propylene oligomer (having 15 
carbons in average). Added thereto were 4 parts of polyoxyethylene 
nonylphenyl ether phosphoric acid ester (polymerization degree of 
oxyethylene: 17), 3 parts of polyoxyethylene nonylphenyl ether sulfuric 
acid ester ammonium (polymerization degree of oxyethylene: 4), and 2 parts 
of oleic acid. Further thereto, 13 parts of the polymer type dispersant 
prepared in Synthesis example 1 was added, and then water was gradually 
added to cause phase-inversion emulsification to prepare an oil-in-water 
type emulsion of a total solid content of 40% by weight. 
EXAMPLE 4 
10 parts of an alkenylsuccinic anhydride derived from addition reaction of 
maleic anhydride to a linear internal olefin (having 16 carbons in 
average) and 30 parts of an aromatic methylene resin (trade name: 
Oligotech 1400, made by Mitsubishi Oil Co., Ltd., number average molecular 
weight: 900) were mixed with 60 parts of an alkenylsuccinic anhydride 
derived from addition reaction of maleic anhydride to a propylene oligomer 
(having 15 carbons in average). Added thereto were 4 parts of 
polyoxyethylene nonylphenyl ether phosphoric acid ester (polymerization 
degree of oxyethylene: 17), 1 parts of polyoxyethylene distyryl phenyl 
ether phosphoric acid ester (polymerization degree of oxyethylene: 10), 
and 3 parts of polyoxyethylene nonylphenyl ether sulfuric acid ester 
ammonium (polymerization degree of oxyethylene: 4). Further thereto, water 
was gradually added to cause phase-inversion emulsification to prepare an 
oil-in-water type emulsion of a total solid content of 40% by weight. 
EXAMPLE 5 
25 Parts of a commercial aromatic methylene resin (trade name: Oligotech 
1300, made by Mitsubishi Oil Co., Ltd., number average molecular weight: 
700) and 5 parts of fumarated rosin (fumaration degree: 9%) were mixed 
with 70 parts of an alkenylsuccinic anhydride derived from addition 
reaction of maleic anhydride to a propylene oligomer (having 15 carbons in 
average). Added thereto were 4 parts of polyoxyethylene nonylphenyl ether 
phosphoric acid ester (polymerization degree of oxyethylene: 17), and 3 
parts of polyoxyethylene nonylphenyl ether sulfuric acid ester ammonium 
(polymerization degree of oxyethylene: 4). Further thereto, water was 
gradually added to cause phase-inversion emulsification to prepare an 
oil-in-water type emulsion of a total solid content of 40% by weight. 
EXAMPLE 6 
30 parts of an aromatic formaldehyde resin (trade name: Oligotech X, a 
trial sample, made by Mitsubishi Oil Co., Ltd., number average molecular 
weight: 770) was mixed with 70 parts of an alkenylsuccinic anhydride 
derived from addition reaction of maleic anhydride to a propylene oligomer 
(having 15 carbons in average). Thereto, there were added 6 parts of 
polyoxyethylene nonylphenyl ether phosphoric acid ester (polymerization 
degree of oxyethylene: 17), and 12 parts of aqueous 25% sodium 
dodecylbenzenesulfonate solution. Further thereto, water was gradually 
added to cause phase-inversion emulsification to prepare an oil-in-water 
type emulsion of a total solid content of 40% by weight. 
EXAMPLE 7 
30 parts of an aromatic formaldehyde resin (trade name: Oligotech X, a 
trial sample, made by Mitsubishi Oil Co., Ltd., number average molecular 
weight: 770) was mixed with 70 parts of an alkenylsuccinic anhydride 
derived from addition reaction of maleic anhydride to a propylene oligomer 
(having 15 carbons in average). Added thereto were 5 parts of 
polyoxyethylene nonylphenyl ether phosphoric acid ester (polymerization 
degree of oxyethylene: 17), and 3 parts of polyoxyethylene nonylphenyl 
ether (polymerization degree of oxyethylene: 15). Further thereto, 8 parts 
of the polymer type dispersant of Synthesis example 3 was added, and then 
water was gradually added to cause phase-inversion emulsification to 
prepare an oil-in-water type emulsion of a total solid content of 35% by 
weight. 
EXAMPLE 8 
40 parts of a commercial aromatic methylene resin (trade name: Oligotech 
1400, made by Mitsubishi Oil Co., Ltd., number average molecular weight: 
900) was mixed with 60 parts of an alkenylsuccinic anhydride derived from 
addition reaction of maleic anhydride to a propylene oligomer (having 12 
carbons in average). Added thereto were 4 parts of polyoxyethylene 
nonylphenyl ether phosphoric acid ester (polymerization degree of 
oxyethylene: 17), and 3 parts of polyoxyethylene nonylphenyl ether 
sulfuric acid ester ammonium (polymerization degree of oxyethylene: 4). 
Further thereto, water was gradually added to cause phase-inversion 
emulsification to prepare an oil-in-water type emulsion of a total solid 
content of 40% by weight. 
EXAMPLE 9 
20 parts of an aliphatic petroleum resin (trade name: Escorez 1304, made by 
Tonex Co., Ltd., average molecular weight: 1000) was mixed with 80 parts 
of an alkenylsuccinic anhydride derived from addition reaction of maleic 
anhydride to a propylene oligomer (having 15 carbons in average). Added 
thereto was 7 parts of polyoxyethylene nonylphenyl ether phosphoric acid 
ester (polymerization degree of oxyethylene: 17). Further thereto, water 
was gradually added to cause phase-inversion emulsification to prepare an 
oil-in-water type emulsion of a total solid content of 40% by weight. 
EXAMPLE 10 
60 parts of a commercial aromatic methylene resin (trade name: Oligotech 
1300, made by Mitsubishi Oil Co., Ltd., number average molecular weight: 
700) was mixed with 40 parts of an alkenylsuccinic anhydride derived from 
addition reaction of maleic anhydride to a propylene oligomer (having 15 
carbons in average). Thereto 8 parts of polyoxyethylene nonylphenyl ether 
phosphoric acid ester (polymerization degree of oxyethylene: 17) was 
added, and the mixture was heated to 60.degree. C. Further, 6 parts of 
aqueous 45% solution of a commercial anionic oligomer emulsifier (trade 
name: Polywet SN-4, made by Sumitomo Naugatuck Co., Ltd.) was added 
thereto. Then water was gradually added to cause phase-inversion 
emulsification to prepare an oil-in-water type emulsion of a total solid 
content of 40% by weight. 
EXAMPLE 11 
10 parts of a commercial aromatic methylene resin (trade name: Oligotech 
1040, made by Mitsubishi Oil Co., Ltd., number average molecular weight: 
300) was mixed with 90 parts of an alkenylsuccinic anhydride derived from 
addition reaction of maleic anhydride to a propylene oligomer (having 15 
carbons in average). Thereto 40 parts of aqueous 25% sodium 
dodecylbenzenesulfonate solution was added. The resulting mixture is 
further mixed with 257 parts of warm water at 40.degree. C. by means of a 
homomixer, and subsequently passed twice through a piston type 
high-pressure emulsifying machine (made by APV Gaulin Co.) at a pressure 
of 300 kg/cm.sup.2 to prepare an oil-in-water emulsion having a total 
solid content of 30% by weight. 
EXAMPLE 12 
An alkenylsuccinic acid was prepared by reacting, with an equimolar amount 
of water, an alkenylsuccinic anhydride derived by addition reaction of 
maleic anhydride to propylene oligomer (having 15 carbons in average). 60 
Parts of the resulting alkenylsuccinic acid was mixed with 40 parts of a 
commercial aromatic methylene resin (trade name: Oligotech 1100, made by 
Mitsubishi Oil Co., Ltd., number average molecular weight: 350). Further 
added thereto were 4 parts of polyoxyethylene nonylphenyl ether sulfuric 
acid ester ammonium, and 40 parts of polymer type dispersant of Synthesis 
Example 2. The resulting mixture was further mixed with 257 parts of hot 
water by means of a homomixer at 5000 rpm, and cooled to prepare an 
oil-in-water emulsion having a total solid content of 30% by weight. 
EXAMPLE 13 
10 parts of a commercial aromatic methylene resin (trade name: Oligotech 
1100, made by Mitsubishi Oil Co., Ltd., number average molecular weight: 
350) was mixed with 90 parts of an alkenylsuccinic anhydride derived from 
addition reaction of maleic anhydride to a propylene oligomer (having 15 
carbons in average). Thereto 67 parts of the polymer type dispersant of 
Synthesis example 2 was added. The resulting mixture was further mixed 
with 315 parts of warm water at 90.degree. C. by means of a homomixer, and 
subsequently passed twice through a piston type high-pressure emulsifying 
machine (made by APV Gaulin Co.) at a pressure of 500 kg/cm.sup.2 to be 
homogenized, and quickly cooled to room temperature, thus an oil-in-water 
emulsion having a total solid content of 35% by weight being prepared. 
EXAMPLE 14 
An alkenylsuccinic acid was prepared by reacting, with an equimolar amount 
of water, an alkenylsuccinic anhydride derived by addition reaction of 
maleic anhydride to propylene oligomer (having 15 carbons in average). 100 
parts of the resulting alkenylsuccinic acid was mixed with 21 parts of the 
dispersant of Synthesis Example 7. The resulting mixture was further mixed 
with 137 parts of hot water at 50.degree. C. by means of a homomixer 
(10,000 rpm), and subsequently passed four times through a piston type 
high-pressure emulsifying machine (made by APV Gaulin Co.) at a pressure 
of 700 kg/cm.sup.2 to be homogenized, and quickly cooled to room 
temperature, to prepare an oil-in-water emulsion having a total solid 
content of 40% by weight. 
EXAMPLE 15 
An alkenylsuccinic acid was prepared by reacting, with an equimolar water, 
an alkenylsuccinic anhydride derived by addition reaction of maleic 
anhydride to propylene oligomer (having 15 carbons in average). 80 parts 
of the resulting alkenylsuccinic acid was mixed with 20 parts of a 
commercial aromatic methylene resin (trade name: Oligotech 1100, made by 
Mitsubishi Oil Co., Ltd., number average molecular weight: 350). Thereto, 
23 parts of the dispersant of Synthesis Example 4 was added. The resulting 
mixture was further mixed with 135 parts of hot water at 90.degree. C. by 
means of a homomixer (10,000 rpm), and subsequently passed 4 times through 
a piston type high-pressure emulsifying machine (made by APV Gaulin Co.) 
at a pressure of 700 kg/cm.sup.2 to be homogenized, and quickly cooled to 
room temperature to prepare an oil-in-water emulsion having a total solid 
content of 40% by weight. 
EXAMPLE 16 
20 parts of commercial anionic acrylamide polymer (solid content: 15%, 
trade name: Polyacron V, made by Misawa Ceramic Chemical Co., Ltd.) was 
mixed with the emulsion prepared in Example 15 to prepare an oil-in-water 
emulsion having a total solid content of 38% by weight. 
EXAMPLE 17 
An alkenylsuccinic acid was prepared by reacting, with an equimolar amount 
of water, an alkenylsuccinic anhydride derived by addition reaction of 
maleic anhydride to propylene oligomer (having 12 carbons in average). 100 
parts of the resulting alkenylsuccinic acid was mixed with 33 parts of the 
dispersant of Synthesis Example 5. The resulting mixture was further mixed 
with 164 parts of hot water at 40.degree. C. by means of a homogenizer 
(10,000 rpm), and subsequently passed four times through a piston type 
high-pressure emulsifying machine (made by APV Gaulin Co.) at a pressure 
of 700 kg/cm.sup.2 to be homogenized, and quickly cooled to room 
temperature to prepare an oil-in water emulsion having a total solid 
content of 25% by weight. 
EXAMPLE 18 
An alkenylsuccinic acid was prepared by reacting, with an equimolar amount 
of water, an alkenylsuccinic anhydride derived by addition reaction of 
maleic anhydride to propylene oligomer (having 15 carbons in average). 100 
parts of the resulting alkenylsuccinic acid was mixed with 23 parts of the 
dispersant of Synthesis Example 8. The resulting mixture was further mixed 
with 135 parts of hot water at 50.degree. C. by means of a homomixer 
(10,000 rpm), and subsequently passed four times through a piston type 
high-pressure emulsifying machine (made by APV Gaulin Co.) at a pressure 
of 700 kg/cm.sup.2 to be homogenized, and quickly cooled to room 
temperature to prepare an oil-in-water emulsion having a total solid 
content of 40% by weight. 
EXAMPLE 19 
An alkenylsuccinic acid was prepared by reacting, with an equimolar amount 
of water, an alkenylsuccinic anhydride derived by addition reaction of 
maleic anhydride to propylene oligomer (having 15 carbons in average). 80 
parts of the resulting alkenylsuccinic acid was mixed with 20 parts of 
cylinder stock, and further 17 parts of the dispersant of Synthesis 
Example 6 was added thereto. The resulting mixture was further mixed with 
174 parts of hot water at 90.degree. C. by means of a homomixer (10,000 
rpm), and subsequently passed four times through a piston type 
high-pressure emulsifying machine (made by APV Gaulin Co.) at a pressure 
of 700 kg/cm.sup.2 to be homogenized, and quickly cooled to room 
temperature to prepare an oil-in-water emulsion having a total solid 
content of 35% by weight. 
EXAMPLE 20 
An alkenylsuccinic acid was prepared by reaction, with an equimolar amount 
of water, an alkenylsuccinic anhydride derived by addition reaction of 
maleic anhydride to n-butene oligomer (having 16 carbons in average). 100 
parts of the resulting alkenylsuccinic acid was mixed with 21 parts of the 
dispersant of Synthesis Example 7. The resulting mixture was further mixed 
with 137 parts of hot water at 50.degree. C. by means of a homomixer 
(10,000 rpm), and subsequently passed four times through a piston type 
high-pressure emulsifying machine (made by APV Gaulin Co.) at a pressure 
of 700 kg/cm.sup.2 to be homogenized, and quickly cooled to room 
temperature to prepare an oil-in-water emulsion having a total solid 
content of 40% by weight. 
COMATIVE EXAMPLE 1 
A commercial emulsion type resin type sizing agent (solid content: 50%, 
trade name: OT-500J, made by Dick Hercules Co.) wherein a component 
essentially consisted of a fumarated resin was emulsified with a polymer 
type dispersant was used. 
COMATIVE EXAMPLE 2 
A commercial saponified rosin type sizing agent (solid content: 50%, trade 
name: RF Size 800L made by Misawa Ceramic Chemical Co., Ltd.) wherein a 
component essentially consisted of maleated rosin was saponified with 
potassium hydroxide was used. 
COMATIVE EXAMPLE 3 
10 parts of polyoxyethylene nonylphenyl ether sulfuric acid ester ammonium 
(polymerization degree of oxyethylene: 4) was added to 100 parts of 
alkenylsuccinic acid derived by addition reaction of maleic anhydride to 
propylene oligomer (having 15 carbons in average). The mixture was stirred 
sufficiently at 50.degree. C. One part of the resulting mixture was 
further mixed with 99 parts of water and was emulsified by means of a 
homomixer at 10,000 rpm for 1 minute to obtain an oil-in-water emulsion 
having a total solid content of 1% by weight. 
COMATIVE EXAMPLE 4 
40 parts of a commercial aromatic methylene resin (trade name: Oligotech 
1400, made by Mitsubishi Oil Co., Ltd., number average molecular weight: 
900) was mixed with 60 parts of alkenylsuccinic anhydride derived from 
addition reaction of maleic anhydride with a linear internal olefin 
(having 16 carbons in average). Thereto further mixed were 8 parts of 
polyoxyethylene nonylphenyl ether phosphoric acid ester (polymerization 
degree of oxyethylene: 17), and 2 parts of polyoxyethylene distyrylphenyl 
ether phosphoric acid ester (polymerization degree of oxyethylene: 10). 
Thereto water was added gradually to cause phase-inversion emulsification 
to prepare an oil-in-water type emulsion of a total solid content of 40% 
by weight. 
COMATIVE EXAMPLE 5 
26 parts of an aqueous solution of potassium hydroxide in 126 parts of 
water were added to 60 parts of alkenylsuccinic anhydride derived by 
addition reaction of maleic anhydride with a propylene oligomer (having 12 
carbons in average). The mixture was stirred within the temperature of 
from 90.degree. to 100.degree. C. for 3 hours, and cooled to room 
temperature to obtain a saponification type alkenylsuccinic anhydride 
sizing agent of a total solid content of 40% by weight. 
COMATIVE EXAMPLE 6 
60 parts of a fumarated rosin (fumaration degree: 9%) was mixed with 40 
parts of an alkenylsuccinic anhydride derived from addition reaction of 
maleic anhydride to a propylene oligomer (having 15 carbons in average). 
Thereto polyoxyethylene nonylphenyl ether phosphoric acid ester 
(polymerization degree of oxyethylene: 17), and 3 parts of polyoxyethylene 
nonylphenyl ether sulfuric acid ester ammonium (polymerization degree of 
oxyethylene: 4) were added. Subsequently water was added gradually to 
cause phase-inversion emulsification to prepare an oil-in-water type 
emulsion of a total solid content of 40% by weight. 
TABLE 1 
______________________________________ 
Storage Stability Test 
Amount of deposition after being left standing 
Standing days 
1 day 7 days 60 days 
______________________________________ 
Example 
1 None None None 
2 None None None 
3 None None None 
4 None None None 
5 None None None 
6 None None None 
7 None None Trace amount 
8 None None Trace amount 
9 None None Trace amount 
10 None None None 
11 None None None 
12 None None Trace amount 
13 None None None 
14 None None None 
15 None None None 
16 None None None 
17 None None None 
18 None None None 
19 None None Trace amount 
20 None None None 
Comparative 
Example 
1 None None Trace amount 
2 -- -- -- 
3 Large amount 
Large amount 
Large amount 
4 None None Small amount 
5 -- -- -- 
6 None None None 
______________________________________ 
TABLE 2 
______________________________________ 
Sizing Effect Measurement Test 
Stockigt sizing degree (seconds) 
Aluminum Sulfate 1.0%, 
Aluminum Sulfate 0.7%, 
Water for dilution & 
Water for dilution & 
paper-making: pH 4.5 
paper-making: pH 6.0 
Just after 
After 1 day 
Just after 
After 1 day 
drying conditioning 
drying conditioning 
______________________________________ 
Example 
1 21 24 14 15 
2 22 25 14 16 
3 20 23 13 14 
4 18 20 11 13 
5 20 21 13 15 
6 19 21 13 15 
7 18 20 12 14 
8 18 19 11 12 
9 19 22 12 13 
10 17 18 11 12 
11 17 20 11 13 
12 17 19 11 12 
13 20 22 14 15 
14 17 18 13 13 
15 22 23 17 17 
16 24 24 17 18 
17 18 18 13 14 
18 17 19 12 14 
19 18 18 12 12 
20 17 17 13 14 
Comparative 
Example 
1 14 15 8 9 
2 7 8 5 5 
3 4 8 2 5 
4 6 6 4 5 
5 10 12 7 8 
6 15 15 9 10 
______________________________________ 
TABLE 3 
______________________________________ 
&lt; Mechanical Stability Test &gt; 
Sludge Occurrence 
______________________________________ 
Example 15 Trace 
Example 16 None 
Comp. Ex. 1 Small 
______________________________________ 
The alkenylsuccinic acid type emulsion sizing agent of the present 
invention is superior in storage stability in high concentration and 
exhibits superior sizing effect immediately after paper making in 
comparison with conventional alkenylsuccinic anhydride emulsion sizing 
agent. Further, it does not become deteriorated in sizing effect in high 
temperature paper making over a broad pH range in comparison with 
saponified type alkenylsuccinic acid type sizing agent. 
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.