JP2008050730A - Cationic surface sizing agent and paper coated with the sizing agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance sizing effects of a surface sizing agent on paper free of an internal sizing agent. <P>SOLUTION: The cationic surface sizing agent includes amines (A) and a copolymer (B) which is a copolymer obtained by polymerizing (a) 18-40 wt.% of a tertiary amino group-containing monomer with (b) 10-80 wt.% of a 4-18C alkyl ester of acrylic or methacrylic acid and (c) 0-70 wt.% of styrenes in the presence of a chain transfer agent and carrying out quaternization or without conducting the quaternization. Since the amines (A) such as laurylamine, oleylamine or distearylamine are further contained in the copolymer (B) prepared by reacting the monomer components of specific species in specified contents, the surface sizing agent is efficiently oriented in fiber surfaces of the paper by interaction of the components (A) and (B). Thereby, sizing properties can effectively be improved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention provides a cationic surface sizing agent that is excellent in sizing effect even on paper containing no or a very small amount of an internally added sizing agent.

Recent trends in papermaking technology include the improvement of operability during papermaking, or the increase in papermaking pH due to neutralization and the reduction of dirt in the papermaking system when calcium carbonate is internally added as a filler. The amount of the sizing agent is reduced, or the coating amount of the surface sizing agent is increased after paper making without internal addition, so that the water resistance of paper and paperboard is improved.
Because of such circumstances, cases where the effect of conventional anionic surface sizing agents is low are increasing, and thus, a cationic surface sizing agent is applied particularly to neutral paper.
The cationic surface sizing agent is generally a copolymer having a tertiary amino group mainly composed of styrenes and a tertiary amino group-containing monomer (that is, a cationic monomer), or a copolymer obtained by quaternizing this copolymer. It consists of an aqueous solution.
The prior art of the cationic surface sizing agent is as follows.

(1) Patent Document 1
For the purpose of improving the size effect, (a) 90-60 mol% of styrenes, (b) tertiary amino group or quaternary amino group-containing monomer 0-30 mol%, (c) other vinyl monomers (( (Meth) acrylic acid ester, vinyl acetate, acrylonitrile, acrylamides, (meth) acrylic acid, etc.) 0-10 mol% and a cationic hydrophobic polymer obtained by polymerization reaction in an organic solvent were mixed with cationized starch. Surface sizing agents are disclosed (see claims 1-6, paragraphs 6-7).

(2) Patent Document 2
For the purpose of imparting good sizing properties and disaggregation properties to the paper, (1) 50-98.5 mol% of styrenes, (2) dialkylaminoalkyl (meth) acrylic acid esters or salts thereof 0.1-0.1 9.9 mol%, (3) 0.1 to 10 mol% of the quaternized product of (2) above, (4) 0 to 48.5 mol% of (meth) acrylic acid alkyl ester, and (2) And (3) is a cationic polymer emulsion comprising a constituent monomer having a total amount of 1.5 to 10 mol%, wherein a copolymer obtained by solution polymerization or bulk polymerization is added to water. What can be used for the sizing agent or the surface sizing agent is disclosed (see claims, pages 2 to 3).

(3) Patent Document 3
A copolymer of a hydrophobic monomer and a monomer having a tertiary amino group is quaternized with oxides for the purpose of reducing generation of wrinkles during polymerization, improving size performance and ink jetting suitability, and reducing foamability. Hydrophobic monomers (such as styrenes and (meth) acrylates) in the presence of a cationic surface sizing agent containing a cationic copolymer (A) or a cationic copolymer (A) A cationic surface sizing agent containing a copolymer obtained by polymerizing B) (particularly emulsion polymerization: paragraph 25) is disclosed (see claims 1 to 6).

(4) Patent Document 4
A copolymer of a hydrophobic monomer and a monomer having a tertiary amino group was quaternized for the purpose of reducing generation of wrinkles during polymerization, improving size performance and inkjet suitability, and reducing foamability. In the presence of a mixture of the cationic copolymer (A-1) and the nonionic surfactant (A-2), a hydrophobic monomer (B) such as styrene or (meth) acrylate is polymerized (particularly Emulsion polymerization: A cationic surface sizing agent containing a copolymer obtained by paragraph 29) is disclosed (see claims 1 to 3).

(5) Patent Document 5
For the purpose of improving the size effect, a cationic copolymer (B) obtained by quaternizing a copolymer (A) of styrenes (a) and dialkylaminoalkyl (meth) acrylamide (b) is used as an emulsifying dispersant. Further, a surface sizing agent obtained by emulsion polymerization of a hydrophobic monomer (C) such as styrenes or (meth) acrylic acid esters is disclosed.

(6) Patent Document 6
In the above Patent Document 5, (meth) acrylic acid dialkylaminoalkyl ester (b) is used in place of the preceding dialkylaminoalkyl (meth) acrylamide (b), and styrenes are used as the subsequent hydrophobic monomer (C). A (meth) acrylic acid ester monomer mixture is used.

(7) Patent Document 7
It consists of a water-soluble or water-dispersible copolymer containing styrenes and dialkylaminoalkyl (meth) acrylate and / or dialkylaminoalkyl (meth) acrylamide as constituent monomers on electrophotographic transfer paper using calcium carbonate as a filler. The use of a sizing agent is disclosed (see claims). In this case, the proportion of styrene used is 40 to 95 mol% (see the upper right column on page 3).

(8) Patent Document 8
Disclosed is a surface sizing agent obtained by quaternizing a copolymer containing 95 to 50 mol% of styrenes and 5 to 50 mol% of dialkylaminoalkyl (meth) acrylamide for the purpose of improving rust prevention and sizing properties. (See claims).

(9) Patent Document 9
For the purposes of internal sizing and surface sizing of paper (see paragraph 1), (a) 20-60% by weight of styrenes, (b) 40-80% by weight of (meth) acrylate, and (c) nonionic Emulsion polymerization of 0 to 20% by weight of the functional monomer is carried out in the presence of an aqueous polymer dispersion that acts as an emulsifier,
The aqueous polymer dispersion comprises (d) tertiary amino group-containing (meth) acrylic acid ester and / or (meth) acrylamide 15 to 35% by weight, (e) styrenes 65 to 85% by weight, and (f) Disclosed is an aqueous cationic polymer dispersion characterized in that a solution polymerization of a monomer mixture consisting of 0 to 20% by weight of a nonionic or cationic monomer is prepared in a saturated carboxylic acid. (See claim 1, paragraph 9).
In preparing the emulsifier, saturated C ₁ -C ₆ carboxylic acid is used as a solvent, and for example, formic acid, acetic acid, propionic acid, butyric acid, hydroxypropionic acid, hydroxyacetic acid and the like are exemplified as the saturated carboxylic acid ( (See paragraph 17).

JP-A-11-323774 JP-A-4-34097 JP 2001-295197 A JP 2001-262495 A JP-A-11-279983 Japanese Patent Laid-Open No. 11-256696 Japanese Patent Application Laid-Open No. 3-16797 JP-A-2-26997 JP 2002-129494 A

Even if a conventional cationic copolymer is applied to paper with extremely low size, which has been increasing in recent years, or paper made without the addition of a sizing agent, it will diffuse into the paper layer and the size effect will be sufficient. It cannot be demonstrated.
For this reason, in order to ensure practical sizing properties, it is necessary to apply a large amount of the above-mentioned copolymer, which is likely to cause problems in terms of operation and cost. This harmful effect increases.
In the above Patent Documents 1 to 9, the size is not a satisfactory level, and the characteristics as a surface sizing agent can be obtained only by means such as composition and blending ratio of various monomers constituting the copolymer and optimization of the polymerization method. It is not easy to improve greatly.

  This invention makes it a technical subject to improve a size effect by coating with the chemical | medical agent amount suppressed on the paper which does not contain an internal sizing agent.

In general, both cationic copolymers and amines have the same cationic charge in an aqueous solution, so it is considered that electrostatic repulsion occurs. In addition, amines cause hydrolysis of the copolymer or water. Although it is considered that the stability of the copolymer is likely to be deteriorated due to a decrease in the property, the present inventors apply a chemical in which amines coexist with this cationic copolymer to paper. Contrary to expectations, it was found that the diffusion of chemicals into the paper layer was suppressed by some interaction and the hydrophobicity was improved.
Based on this knowledge, the present inventors polymerized a tertiary amino group-containing monomer and a hydrophobic monomer to produce a cationic copolymer. And a proper combination of (meth) acrylic acid ester, and the ratio of these monomer components is specified, and amines such as laurylamine, oleylamine, distearylamine, trimethyllaurylammonium chloride are polymerized in the copolymer. When added before or after quaternization after polymerization or after quaternization, it is found that the size effect can be greatly improved even if the surface sizing agent obtained is applied to paper without an internal sizing agent. The present invention has been completed.

That is, the present invention 1 comprises an amine (A) and a copolymer (B),
The copolymer (B) is
(a) 18-40% by weight of a tertiary amino group-containing monomer,
(b) (meth) 10 to 80% by weight of alkyl esters of C ₄ -C ₁₈ acrylic acid,
(c) a cationic surface size characterized by being a copolymer obtained by polymerizing styrenes in an amount of 0 to 70% by weight in the presence of a chain transfer agent to be quaternized or not quaternized. It is an agent.

Invention 2 relates to the invention 1, wherein the amine (A) is an amine having one or more C _{6 to} C ₂₂ substituents, an ammonium salt, a polyvalent amine, or a polyamine obtained by a condensation reaction of an alkylamine and an epihalohydrin. A cationic surface sizing agent characterized in that it is at least one selected from the group consisting of:

  The present invention 3 is the invention 1 or 2, wherein the amine (A) is added in an amount of 0.01 to 30% by weight based on the total amount of the monomer components (a) to (c) of the copolymer (B). It is a cationic surface sizing agent characterized by mixing.

  Invention 4 is characterized in that in any one of Inventions 1 to 3, the tertiary amino group-containing monomer (a) is dialkylaminoalkyl (meth) acrylate and / or dialkylaminoalkyl (meth) acrylamide. A cationic surface sizing agent.

  The present invention 5 is the method according to any one of the present inventions 1 to 4, wherein the amine components (A) are added to polymerize the monomer components (a) to (c), or the monomer components (a) to (c) are polymerized. Then, the amines (A) are added and then quaternized or not quaternized, or the copolymer (B) is quaternized and then the amines (A) are added. Cationic surface sizing agent.

  The present invention 6 comprises a content of the amine (A) of the present invention 1 or 2 and the copolymer (B) of the present invention 1 or 4, or further comprising a polysaccharide, polyvinyl alcohol, or polyacrylamide. It is a surface treatment method in which an inclusion containing at least one water-soluble polymer selected from the group is applied to the surface of paper.

  The present invention 7 is a base paper containing at least one water-soluble polymer selected from the group consisting of the cationic surface sizing agent according to any one of the above-mentioned present inventions 1 to 5, or a polysaccharide, polyvinyl alcohol, or polyacrylamide. This paper is coated on the surface.

  The present invention 8 is the coated paper according to the present invention 7, wherein the base paper is a paper that does not contain an internal sizing agent, or a neutral paper having a Steecht sizing degree of 2 seconds or less. .

As described above, there is a problem that even if a conventional cationic copolymer is applied, it diffuses into the paper layer and the size effect cannot be exhibited sufficiently.
On the other hand, in the cationic surface sizing agent of the present invention, since the copolymer (B) obtained by reacting a specific monomer component with a specific content further contains the amine (A), the effect is exhibited. The mechanism is not yet clear, but when applied to paper, some interaction acts between this copolymer (B) and amines (A) in the coating solution, at the time of coating, or at the time of drying. It can be estimated that the processed surface sizing agent does not diffuse into the paper layer, is uniformly distributed in the vicinity of the paper surface, and is efficiently oriented on the fiber surface of the paper, thereby improving hydrophobicity.
As a result, the size of the paper can be greatly improved, and even if the amount of coating on the paper is reduced, the same quality as when the conventional surface sizing agent is applied at a high concentration can be obtained. In addition, the sizing effect when the internal sizing agent is used in combination can be achieved by using only the surface sizing agent, and is particularly suitable for improving the sizing property of the sizing agent-free internally added paper and high ash neutral paper.
Furthermore, conventionally, the sizing agent component that did not fix on the paper due to the use of a large amount of sizing agent caused precipitation, precipitation, foaming, etc. in the circulation system of the coating liquid. By reducing the amount used, the above operational troubles can be prevented smoothly and costs can be reduced, so productivity is improved.

In the present invention, a specific ratio of amines (A), (a) tertiary amino group-containing monomer, (b) C ₄ -C ₁₈ alkyl ester of (meth) acrylic acid, and (c) styrenes is specified. A cationic surface sizing agent containing a copolymer (B) which is polymerized by quaternization or not quaternized. Second, the amines (A) and the copolymer (B) Is the surface treatment method, and thirdly, the paper coated with the surface sizing agent, especially the paper coated on the base paper containing no or a very small amount of internal sizing agent. .

As the (a) tertiary amino group-containing monomer which is a constituent of the copolymer (B) of the present invention, as shown in the present invention 4, dialkylaminoalkyl (meth) acrylate and / or dialkylaminoalkyl (meth) Acrylamide is suitable.
The dialkylaminoalkyl (meth) acrylate is dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminoethyl (meth) acrylate, diethylaminopropyl (meth) acrylate, or an organic acid salt of these monomers, halogen Representative examples include hydrogen halides and sulfates, and dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate are preferred.
The dialkylaminoalkyl (meth) acrylamide is dimethylaminoethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, diethylaminoethyl (meth) acrylamide, diethylaminopropyl (meth) acrylamide, or an organic acid salt of these monomers, halogen Representative examples include hydrogen halides and sulfates, and dimethylaminopropyl (meth) acrylamide and diethylaminopropyl (meth) acrylamide are preferred. In addition, other tertiary amino group-containing monomers such as dimethylallylamine and diallylmonomethylamine can also be used.

Examples of the C ₄ -C ₁₈ alkyl ester of (b) (meth) acrylic acid, which is a constituent of the copolymer (B) of the present invention, include n-butyl (meth) acrylate, iso-butyl (meth) acrylate, t -Hydrocarbon esters such as butyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, etc., aliphatic only In addition, (meth) acrylic acid esters containing alicyclic or aromatic hydrocarbon groups can also be used.
Preferred monomer components (b) are iso-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and lauryl (meth) acrylate.

  Examples of the (c) styrenes that are constituents of the copolymer (B) of the present invention include styrene, α-methylstyrene, vinyltoluene, ethylvinyltoluene, chloromethylstyrene, vinylpyridine, and the like.

In producing the copolymer (B) of the present invention, in addition to the components (a) to (c), other vinyl monomers can be used as necessary.
Other monomers include C ₁ -C ₃ alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, iso-propyl (meth) acrylate, hydroxyethyl Hydroxyl group-containing (meth) acrylates such as (meth) acrylate and hydroxypropyl (meth) acrylate, amide groups such as (meth) acrylamide, dimethyl (meth) acrylamide, diethyl (meth) acrylamide and iso-propyl (meth) acrylamide Containing monomers, acrylonitrile, vinyl acetate and the like.
Therefore, for example, a copolymer containing the component (a) or the component (c) and using a combination of a C ₄ -C ₁₈ alkyl ester of (meth) acrylic acid and a C ₁ -C ₃ alkyl ester is the copolymer of the present invention. Although included in the combined, using only alkyl esters of C ₁ -C ₃ of (meth) acrylic acid, a copolymer that does not use a C ₄ -C ₁₈ alkyl esters, departing from this invention.

Next, the ratio of each monomer component constituting the copolymer (B) of the present invention will be described. First, the tertiary amino group-containing monomer (a) is 18 to 40% by weight, preferably 20 to 35% by weight. It is. If it is less than 18% by weight, the solubility in water and the fixability to the pulp fiber are lowered, and if it exceeds 40% by weight, the hydrophobicity is lowered and the size effect is reduced.
The content of the alkyl ester (b) having 4 to 18 carbon atoms of (meth) acrylic acid is 10 to 80% by weight, preferably 15 to 70% by weight. When the amount is less than 10% by weight, the hydrophobicity is lowered, the solubility in the polymerization solvent is lowered, and a copolymer having a non-uniform composition is generated, and the size effect is lowered. If it exceeds 80% by weight, the ratio of the tertiary amino group-containing monomer that becomes a hydrophilic site becomes too low, and the size effect is also lowered. That is, in order to effectively exhibit size, an appropriate amount of component (b) is required as a hydrophobic monomer.
Moreover, content of styrene (c) is 0 to 70 weight%, Preferably it is 0 to 60 weight%. If it exceeds 70% by weight, the solubility in the polymerization solvent is lowered during the polymerization, leading to the formation of a copolymer having a non-uniform composition. In addition, styrene-rich copolymer components have strong intermolecular cohesive energy and extremely high hydrophobicity, so a large amount of water-insoluble components are produced in the water-solubilization process after polymerization, and uniform fixing to paper is impaired. It is. However, since styrenes (c) are more hydrophobic than (meth) acrylic acid esters, they are effective in imparting water repellency to paper and can be contained in appropriate amounts in the copolymer.
Further, other monomers are used as necessary, but their content is 0 to 30% by weight, preferably 0 to 20% by weight.

The method for producing the copolymer of the present invention is not particularly limited, but it is preferably produced by solution polymerization in an organic solvent using components (a) to (c) as constituent monomers.
Examples of the organic solvent include oxygen-containing hydrocarbons such as alcohol and ketone, and aromatic hydrocarbons such as toluene.
For example, isopropanol, n-butanol, iso-butanol, t-butanol, 2-butanol, methyl ethyl ketone, methyl-n-propyl ketone, 3-methyl-2-butanol, diethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, diisopropyl ketone , Ethylbenzene, toluene and the like.
In the present invention, it is necessary to perform polymerization in the presence of a chain transfer agent from the viewpoint of smoothly performing a polymerization reaction by preventing an increase in viscosity during solution polymerization.
As the chain transfer agent, an oil-soluble or water-soluble chain transfer agent can be arbitrarily used. However, when polymerizing in an oleophilic organic solvent, the oil-soluble chain transfer agent uses a hydrophilic organic solvent. In particular, water-soluble chain transfer agents are relatively preferred. Further, an oil-soluble chain transfer agent and a water-soluble chain transfer agent may be used in combination.
Examples of the oil-soluble chain transfer agent include t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, mercaptans such as mercaptopropionate dodecyl, hydrophobic allyl compounds such as (meth) allyl methacrylate, cumene, Examples thereof include carbon tetrachloride, α-methylstyrene dimer, and terpinolene.
As the water-soluble chain transfer agent, in addition to mercaptans such as mercaptoethanol, thioglycerol, thiomalic acid, thioglycolic acid and salts thereof, (meth) allyl alcohol, (meth) allylamine, (meth) allylsulfonic acid and its Examples thereof include hydrophilic allyl compounds such as salts and ethanolamine.
The amount of the chain transfer agent used relative to the monomer is preferably about 1 to 5% by weight, but is not limited to this range.

Moreover, there is no restriction | limiting in the polymerization initiator to be used, An azo polymerization initiator, a peroxide polymerization initiator, and another initiator can be used arbitrarily.
Examples of the azo polymerization initiator include azobismethylbutyronitrile, dimethylazobisisobutyrate, azobisdimethylvaleronitrile, azobisisobutyronitrile, azobis-2-amidinopropane hydrochloride, and the like.
Examples of the peroxide polymerization initiator include benzoyl persulfate, t-butylperoxybenzoate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexanoate, cumene hydroperoxide, and the like. .
Thus, in the present invention, the polymerization reaction is carried out in the presence of a chain transfer agent, but the polymerization reaction may be carried out by a known method including solution polymerization, and is not particularly limited.

The copolymer (B) obtained by polymerizing the above components (a) to (c) or other components as necessary as a constituent monomer is a quaternizing agent from the standpoint of solubility in water. However, it does not exclude the copolymer (B) in which the tertiary amino group is not quaternized.
The quaternizing agents are dimethyl sulfate, dimethyl carbonate, methyl chloride, allyl chloride, benzyl chloride, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, epibromohydrin, ethylene chlorohydrin, 3-chloro-1, 2- Propanediol, 3-chloro-2-hydroxypropyltrimethylammonium chloride, glycidol, butyl glycidyl ether, allyl glycidyl ether, glycidyl methacrylate and the like can be used alone or in combination. Of the quaternizing agents, epichlorohydrin, benzyl chloride, 3-chloro-1,2-propanediol are preferable.
By making the copolymer quaternized, solubility in water increases in a wide pH range including neutral and alkaline sides, and it can be uniformly dispersed in the coating solution, so that it exhibits a good size effect Can be expected.
This quaternization treatment is generally carried out by removing the solvent after water-solubilizing the cationic copolymer and quaternizing the copolymer. However, after quaternization, the solvent is removed. There is no problem.
The quaternization treatment is basically performed from the viewpoint of facilitating solution polymerization by cation treatment with a quaternizing agent after copolymerizing a constituent monomer including the tertiary amino group-containing monomer (a). The tertiary amino group-containing monomer (a) can be quaternized in advance, and the resulting quaternary ammonium base-containing monomer can be copolymerized.

The surface sizing agent of the present invention is characterized in that the copolymer (B) obtained by reacting the monomer components (a) to (c) further contains an amine (A).
The type of the amines (A) is not particularly limited, but amines having a specific number of carbons are preferable from the viewpoint of improving hydrophobicity, for example, as follows (see the present invention 2).
(1) An amine having at least one substituent having 6 to 22 carbon atoms
(2) An ammonium salt having at least one substituent having 6 to 22 carbon atoms
(3) A polyvalent amine having at least one substituent having 6 to 22 carbon atoms
(4) An amine or ammonium salt obtained by a condensation reaction of an alkylamine and an epihalohydrin having at least one substituent having 6 to 22 carbon atoms

Specific examples of the amines (A) include primary amines such as butylamine, hexylamine, octylamine, laurylamine, oleylamine and stearylamine, secondary amines such as laurylmonomethylamine and distearylamine, dimethyloctylamine, Tertiary amines such as dimethyllaurylamine, dimethylmyristylamine, dimethylpalmitylamine, dimethylbenzylamine, dilaurylmonomethylamine, trioctylamine, quaternary ammonium salts such as laurylammonium bromide, dimethyllaurylammonium chloride, hexamethylenediamine, Piperidine, N-benzylethylenediamine, hardened beef tallow propylenediamine, polyvalent amines such as diethylenetriamine, triethylenetetramine, dimethylamine and epichloro A polyamine obtained by condensation reaction of Dorin.
Among the amines (A), as shown in the present invention 2, the larger the number of carbon atoms in the substituent and the higher the hydrophobicity, the better the size effect, the weaker the odor peculiar to amines, and the better the handling. In some cases, the aqueous solution of the sizing agent may not be uniformly mixed with other components and may precipitate, or may be non-uniformly fixed on paper when coated.
For this reason, in the amines (A), laurylamine, oleylamine, distearylamine, dimethyllaurylamine, dimethylmyristylamine, and trimethyllaurylammonium chloride are preferable.
Further, as described above, the amines (A) of the present invention include quaternary ammonium salts in addition to various amines, but amides are excluded as shown in Test Examples described later.

The amines (A) and copolymers (B) of the present invention can be used alone or in combination, respectively.
As shown in the present invention 3, the content of the amines (A) is 0.01 to 30 with respect to the total amount of the monomer components (a), (b) and (c) constituting the copolymer (B). % By weight is suitable and 0.1-20% by weight is preferred. When the amount is less than 0.01% by weight, the size effect is almost the same as that when the copolymer (B) is used alone. When the amount exceeds 30% by weight, the proportion of the copolymer (B) is relatively reduced to reduce the size. As a result, the mixing property with the copolymer (B) and the water-soluble polymer is hindered, and the viscosity of the sizing agent is increased. Furthermore, when there are too many amines (A), there exists a possibility of raising the pH of a liquid mixture and carrying out the alkali hydrolysis of the functional group which a copolymer (B) has, and losing cationic property.
The content of the amines (A) is influenced by the monomer composition of the copolymer (B), and the amines (A) can be used in combination with the properties of the paper to be coated.

In order to contain the amine (A) in the copolymer (B), it may be added before the polymerization of the copolymer (B) as shown in the present invention 5, or (2) polymerization It may be added later.
In addition, when the copolymer (B) is quaternized, the addition (2) after the polymerization is further performed by adding the amines (A) after the polymerization and before the quaternization or after the quaternization. It is divided when adding.
The surface sizing agent to which amines are added after polymerization is a concept including the surface sizing agent to which amines (A) are added at the time of preparing the coating liquid.
Therefore, the method of preparing a coating liquid by simultaneously mixing the amines (A) with the copolymer (B) or further with a water-soluble polymer (polysaccharide, etc.) It belongs to the form added after polymerization (after quaternization) of (B) (that is, (2) above). That is, the amines (A) and the copolymer (B) are in a coexistence state at the time of preparation of the coating liquid, and the surface sizing agent of the present invention is constituted.

The present invention 6 is a surface treatment method in which a chemical containing the amines (A) and the copolymer (B) of the present invention is applied to the paper surface.
That is, in this surface treatment method, the amines (A) may be added at any time before the polymerization of the copolymer (B), after the polymerization, or at the time of preparing the coating liquid. Included in this method.
In this surface treatment method, in addition to the amines (A) and the copolymer (B), at least one water-soluble polymer selected from the group consisting of polysaccharides, polyvinyl alcohols, and polyacrylamides is further added. The added content may be applied to the surface of the paper.

This invention 7 is various paper which coated the cationic surface sizing agent of the said inventions 1-5 on the base paper.
The surface size of the present invention can be widely applied regardless of whether it is acidic paper using aluminum sulfate as a fixing agent or neutral paper using calcium carbonate as a filler, but neutral paper is preferred.
Specific examples of the base paper include newsprint paper, inkjet paper, thermal recording base paper, pressure-sensitive recording base paper, high-quality paper, paperboard, and other papers. The surface sizing agent of the present invention is a combination with an internal sizing agent. Therefore, in particular, the base paper is preferably paper that does not contain an internal sizing agent (whether acidic paper or neutral paper), and neutral paper having a Steecht sizing degree of 2 seconds or less (this book). (Invention 8) However, the surface sizing agent of the present invention does not exclude application to paper containing an internal sizing agent.
When the surface sizing agent of the present invention is applied, the adhesion amount of the surface sizing agent is about 0.01 to 0.2 g / m ² , preferably about 0.02 to 0.1 g / m ² , Regardless of coating or double-sided coating.
On the other hand, as shown in the present invention 7, on the surface of the base paper, in addition to the surface sizing agent of the present invention, at least one water-soluble highly selected from the group consisting of polysaccharides, polyvinyl alcohols, and polyacrylamides is further provided. Of course, molecules can be applied (this additional application of the water-soluble polymer corresponds to the present invention 6). Examples of the polysaccharide include starches such as oxidized starch, etherified starch, esterified starch, and other modified starches.
In addition, when coating, it goes without saying that an anti-slip agent, a release agent, a rust inhibitor, an antiseptic, and other additives can be used in combination in addition to the water-soluble polymer.

Examples of the cationic surface sizing agent of the present invention, and sizing evaluation test examples when the surface sizing agent obtained in the example is applied to high-quality base paper and newspaper base paper will be sequentially described below. Further, “parts” and “%” in Examples and Test Examples are based on weight unless otherwise specified.
The present invention is not limited to the following examples and test examples, and it is needless to say that arbitrary modifications can be made within the scope of the technical idea of the present invention.

<< Example of surface sizing agent >>
Among Examples 1 to 7, Example 1 is an example in which oleylamine is mixed before polymerization of the copolymer, Example 2 is an example in which trioctylamine is mixed after polymerization of the copolymer and before quaternization, and Example 3 is an example in which dilauryl monomethylamine is mixed after quaternization of the copolymer, Example 4 is an example in which ammonium salt is mixed at the time of preparing the coating solution after quaternization of the copolymer, and Example 5 has many examples. Example 6 in which a polyvalent amine was mixed before polymerization of the copolymer, Example 6 was an example in which a condensed polyamine of dimethylamine and epichlorohydrin was mixed after polymerization and before quaternization, and Example 7 was prepared by adding dimethylmyristylamine. This is an example of mixing after quaternization of the copolymer.

  On the other hand, among Comparative Examples 1 to 9, Comparative Example 1 is an example in which the content of the cationic monomer (a) is less than the lower limit (18%), and Comparative Example 2 has an upper content of the cationic monomer (a) (40 %), Comparative Example 3 uses a short chain alkyl ester having 2 carbon atoms instead of long chain alkyl ester (b), and Comparative Example 4 has a lower content of long chain alkyl ester (b). Less than (10%), an example in which stearylamine was mixed during preparation of the coating liquid, Comparative Example 5 was an example in which the content of the long-chain alkyl ester (b) exceeded the upper limit (80%), and Comparative Example 6 was a styrene An example in which the content of (c) exceeds the upper limit (70%), Comparative Example 7 is an example in which amides are used in combination with a copolymer instead of amines. Comparative Example 8 uses only a copolymer and does not use amines (i.e., based on Example 4 above, the copolymer was quaternized and then mixed with an ammonium salt to obtain a sizing agent) Example). Comparative Example 9 is a blank example using only amines and no copolymer.

  In addition, the monomer composition of the copolymer (B) which comprises each surface sizing agent of Examples 1-7 and Comparative Examples 1-7, the kind of amines (A), and mixing time were put together in FIG. The cationic monomer in the figure represents a tertiary amino group-containing monomer (a), and (meth) acrylate represents (meth) acrylic acid ester (b) or a short chain ester. DM is dimethylaminoethyl methacrylate, DA is dimethylaminoethyl acrylate, DEAEA is diethylaminoethyl acrylate, DMAPAA is dimethylaminopropyl acrylamide, DMAPMA is dimethylaminopropyl methacrylamide, NBMA is n-butyl methacrylate, and EHMA is 2-ethylhexyl methacrylate. , LMA is lauryl methacrylate, CHA is cyclohexyl acrylate, BzMA is benzyl methacrylate, IBMA is iso-butyl methacrylate, TBMA is t-butyl methacrylate, EMA is ethyl methacrylate, TBA is t-butyl acrylate, CHMA is cyclohexyl methacrylate, St is styrene , VT is vinyl toluene, α-MSt is α-methylstyrene Respectively.

(1) Example 1
30 parts of dimethylaminoethyl methacrylate, 60 parts of n-butyl methacrylate, 10 parts of styrene, 15 parts of oleylamine, 2 parts of n-dodecyl mercaptan as a chain transfer agent, and 50 parts of toluene are placed in a four-necked flask. The mixture was heated to 85 ° C., 2.5 parts of 2,2′-azobisisobutyronitrile was added as an initiator, and polymerization was carried out at 90 ° C. for 3 hours.
Next, 300 parts of water and 13 parts of 90% acetic acid were added to make it water-soluble, and then distilled by heating to distill off toluene.
Thereafter, 6 parts of epichlorohydrin was added at 85 ° C., reacted for 3 hours, cooled to 50 ° C., water was added, and an amine-containing cationic copolymer (surface sizing agent) having a solid content of 20% and a pale yellow turbid solution was obtained. Obtained.

(2) Example 2
20 parts of dimethylaminoethyl acrylate, 40 parts of 2-ethylhexyl methacrylate, 40 parts of styrene, 2 parts of t-dodecyl mercaptan as a chain transfer agent, and 50 parts of methyl isobutyl ketone are placed in a four-necked flask up to 85 ° C. The mixture was heated to add 2.5 parts of benzoyl peroxide as an initiator, and polymerized at 90 ° C. for 3 hours.
Next, 300 parts of water and 9 parts of 90% acetic acid were added to make it water-soluble, and then heated to distill off methyl isobutyl ketone.
Thereafter, 0.2 parts of trioctylamine and 9 parts of epichlorohydrin were added at 85 ° C., reacted for 3 hours, cooled and diluted with water, and an amine-containing cationic copolymer having a solid content of 20% and a pale yellow turbid solution. (Surface sizing agent) was obtained.

(3) Example 3
35 parts of diethylaminoethyl acrylate, 60 parts of lauryl methacrylate, 5 parts of vinyltoluene, 2 parts of chain transfer agent n-dodecyl mercaptan and 50 parts of toluene are placed in a four-necked flask and heated to 105 ° C. to start. 2.5 parts of t-butylperoxyisopropyl monocarbonate was added as an agent, and polymerization was performed at 110 ° C. for 3 hours.
Subsequently, 300 parts of water and 12 parts of 90% acetic acid were added to make it water-soluble, and then distilled by heating to distill off toluene.
Thereafter, 15 parts of benzyl chloride was added at 85 ° C. and reacted for 3 hours. After adding 0.5 parts of dilauryl monomethylamine, the mixture was cooled and diluted with water. Sex copolymer (surface sizing agent) was obtained.

(4) Example 4
25 parts of dimethylaminopropylacrylamide, 65 parts of cyclohexyl acrylate, 10 parts of α-methylstyrene, 1 part of n-dodecyl mercaptan as a chain transfer agent and 20 parts of isopropanol are placed in a four-necked flask and heated to 85 ° C. Then, 2.5 parts of t-butylperoxy-2-ethylhexanoate was added as an initiator and polymerized at 90 ° C. for 3 hours.
Next, 300 parts of water and 11 parts of 90% acetic acid were added to make it water-soluble, then 10 parts of epichlorohydrin was added at 85 ° C. without solvent distillation and reacted for 3 hours, cooled, diluted with water, and 20% solid content. A white turbid cationic copolymer was obtained.
Thereafter, the cationic copolymer, lauryl ammonium chloride, and oxidized starch are mixed to prepare a coating solution. In this case, lauryl ammonium chloride is used with respect to 100 parts of the total amount of the constituent monomers of the cationic copolymer. 20 parts were mixed.

(5) Example 5
4 parts of 40 parts of dimethylaminoethyl methacrylate, 50 parts of 2-ethylhexyl methacrylate, 10 parts of benzyl methacrylate, 2 parts of N-benzylethylenediamine, 3 parts of t-dodecyl mercaptan as a chain transfer agent, and 50 parts of methyl isobutyl ketone The flask was placed in a neck flask, heated to 105 ° C., 2.5 parts of t-butyl peroxyisopropyl monocarbonate was added as an initiator, and polymerization was performed at 110 ° C. for 3 hours.
Next, 300 parts of water and 17 parts of 90% acetic acid were added to make it water-soluble, and then heated to distill off methyl isobutyl ketone.
Then, 20 parts of 3-chloro-1,2-propanediol was added at 95 ° C., reacted for 5 hours, cooled and diluted with water, and the amine-containing cationic copolymer of 20% solid content and light brown turbid liquid was obtained. A coalescence (surface sizing agent) was obtained.

(6) Example 6
Four parts of 10 parts of dimethylaminoethyl methacrylate, 10 parts of dimethylaminopropylmethacrylamide, 75 parts of iso-butyl methacrylate, 5 parts of styrene, 1.5 parts of thioglycolic acid as a chain transfer agent, and 50 parts of isopropanol The flask was placed in a flask, heated to 85 ° C., 2.5 parts of 2,2′-azobisisobutyronitrile was added as an initiator, and polymerization was carried out at 90 ° C. for 3 hours.
Next, 300 parts of water and 8 parts of 90% acetic acid were added to make it water-soluble, and then distilled by heating to distill off isopropanol.
Then, 1 part of polyamine (dimethylamine-epichlorohydrin condensation polymer) and 10 parts of epichlorohydrin were added at 85 ° C., reacted for 3 hours, cooled to 50 ° C., water was added, solid content 20%, light yellow transparent liquid amine A containing cationic copolymer (surface sizing agent) was obtained.

(7) Example 7
Four parts of 20 parts of dimethylaminoethyl methacrylate, 77 parts of t-butyl methacrylate, 2 parts of styrene, 1 part of α-methylstyrene, 1.8 parts of n-dodecyl mercaptan as a chain transfer agent, and 15 parts of isopropanol The flask was placed in a flask, heated to 85 ° C., 2 parts of 2,2′-azobisisobutyronitrile was added as an initiator, and polymerization was carried out at 90 ° C. for 3 hours.
Next, 300 parts of water and 8 parts of 90% acetic acid were added to make it water-soluble, then 8 parts of epichlorohydrin was added at 85 ° C. without solvent distillation and reacted for 3 hours. After adding 8 parts of dimethyl myristylamine, the mixture was cooled. Dilution with water gave an amine-containing cationic copolymer (surface sizing agent) having a solid content of 20% and a pale yellow turbid solution.

(8) Comparative Example 1
Four parts of 15 parts of dimethylaminoethyl methacrylate, 70 parts of 2-ethylhexyl methacrylate, 15 parts of styrene, 0.2 part of octylamine, 1.5 parts of chain transfer agent thioglycolic acid and 50 parts of isopropanol The flask was placed in a flask, heated to 85 ° C., 2.5 parts of 2,2′-azobisisobutyronitrile was added as an initiator, and polymerization was carried out at 90 ° C. for 3 hours.
Next, 300 parts of water and 6 parts of 90% acetic acid were added to make it water-soluble, and then distilled by heating to distill off isopropanol.
Then, 10 parts of epichlorohydrin was added at 85 ° C., reacted for 3 hours, cooled to 50 ° C. and water was added to obtain an amine-containing cationic copolymer (surface sizing agent) having a solid content of 20% and a white turbid liquid. It was.

(9) Comparative example 2
60 parts of dimethylaminoethyl acrylate, 40 parts of n-butyl methacrylate, 3.5 parts of chain transfer agent n-dodecyl mercaptan and 50 parts of isopropanol are placed in a four-necked flask and heated to 85 ° C. as an initiator. 2.5 parts of t-butylperoxy-2-ethylhexanoate was added and polymerized at 90 ° C. for 3 hours.
Subsequently, 300 parts of water and 28 parts of 90% acetic acid were added to make it water-soluble, and then distilled by heating to distill off isopropanol.
Thereafter, 5 parts of dimethyl laurylamine and 10 parts of epichlorohydrin were added at 85 ° C., reacted for 3 hours, cooled to 50 ° C., water was added, and the amine-containing cationic copolymer having a solid content of 20% and a pale yellow transparent liquid ( Surface sizing agent) was obtained.

(10) Comparative Example 3
35 parts of dimethylaminoethyl acrylate, 45 parts of ethyl methacrylate, 20 parts of styrene, 2.5 parts of t-dodecyl mercaptan as a chain transfer agent, and 50 parts of toluene are placed in a four-necked flask and heated to 85 ° C. As an initiator, 2.5 parts of t-butylperoxy-2-ethylhexanoate was added and polymerized at 90 ° C. for 3 hours.
Next, 300 parts of water and 15 parts of 90% acetic acid were added to make it water-soluble, and then distilled by heating to distill off toluene.
Then, 10 parts of epichlorohydrin was added at 85 ° C. and reacted for 3 hours, 10 parts of diethylenetriamine was cooled to 50 ° C., water was added, and the amine-containing cationic copolymer (solid surface 20%, pale yellow turbid liquid (surface Sizing agent) was obtained.

(11) Comparative example 4
30 parts of dimethylaminopropylacrylamide, 5 parts of t-butyl acrylate, 65 parts of styrene, 2 parts of n-dodecyl mercaptan as a chain transfer agent and 40 parts of methyl isobutyl ketone are placed in a four-necked flask and heated to 105 ° C. Then, 2.5 parts of t-butylperoxyisopropyl monocarbonate was added as an initiator, and polymerization was carried out at 110 ° C. for 3 hours.
Subsequently, 300 parts of water and 12 parts of 90% acetic acid were added to make it water-soluble, and then heated to distill off methyl isobutyl ketone. Then, 12 parts of 3-chloro-1,2-propanediol was added at 95 ° C., reacted for 5 hours, cooled to 50 ° C., added with water, and a cationic copolymer of white emulsion liquid having a solid content of 20%. Got.
Thereafter, the cationic copolymer, stearylamine and oxidized starch were mixed to prepare a coating liquid. As a ratio at that time, stearylamine 15 was added to 100 parts of the total amount of constituent monomers of the cationic copolymer. The parts were mixed.

(15) Comparative Example 5
15 parts of dimethylaminoethyl methacrylate, 85 parts of lauryl methacrylate, 2 parts of benzyldimethylamine, 1.2 parts of chain transfer agent thioglycerol and 40 parts of isopropanol are placed in a four-necked flask and heated to 85 ° C. As an initiator, 2.5 parts of 2,2′-azobisisobutyronitrile was added, and polymerization was performed at 90 ° C. for 3 hours.
Next, 300 parts of water and 6 parts of 90% acetic acid were added to make it water-soluble, and then distilled by heating to distill off isopropanol.
Then, 8.5 parts of epichlorohydrin was added at 85 ° C., reacted for 3 hours, cooled to 50 ° C., water was added, and the amine-containing cationic copolymer (surface sizing agent) having a solid content of 20% and a pale yellow turbid liquid was added. )

(16) Comparative Example 6
15 parts of dimethylaminopropyl methacrylamide, 10 parts of cyclohexyl methacrylate, 75 parts of styrene, 3 parts of α-methylstyrene dimer as a chain transfer agent and 40 parts of toluene are placed in a four-necked flask and heated to 85 ° C. As an initiator, 2.5 parts of 1,1′-azobis (cyclohexane-1-carbonitrile) was added and polymerized at 90 ° C. for 3 hours.
Subsequently, 300 parts of water and 6 parts of 90% acetic acid were added to make it water-soluble, and then distilled by heating to distill off toluene.
Thereafter, 7 parts of benzyl chloride and 2 parts of piperazine were added at 85 ° C., reacted for 3 hours, cooled to 50 ° C., water was added, 20% solid content, white emulsion liquid amine-containing cationic copolymer (surface Sizing agent) was obtained.

(17) Comparative Example 7
30 parts of dimethylaminoethyl methacrylate, 55 parts of iso-butyl methacrylate, 15 parts of styrene, 1.8 parts of n-dodecyl mercaptan as a chain transfer agent, and 25 parts of isopropyl alcohol are placed in a four-necked flask and heated to 85 ° C. The mixture was heated, 2.5 parts of 2,2′-azobisisobutyronitrile was added as an initiator, and polymerization was carried out at 90 ° C. for 3 hours.
Subsequently, 300 parts of water and 12 parts of 90% acetic acid were added to make it water-soluble, and then 10 parts of epichlorohydrin was added at 85 ° C. without solvent distillation and reacted for 3 hours. Polyamide polyamine-epichlorohydrin resin (Harmide PY-525A, Harima 3 parts of Kasei Chemical Co., Ltd.) was added, cooled and diluted with water to obtain a 20% solid content, light yellow transparent amine-containing cationic copolymer (surface sizing agent).

(18) Comparative Example 8
Based on Example 4, the surface sizing agent was obtained in the same manner as in Example 4 except that the copolymer was quaternized and no lauryl ammonium chloride was mixed.

(19) Comparative Example 9
A surface sizing agent was obtained only from dimethyl palmitylamine without using a copolymer (the content of amines is described in the item of preparation of coating liquid described later).

  Therefore, each surface sizing agent obtained in Examples 1 to 7 and Comparative Examples 1 to 9 was applied to high-quality base paper without an internal sizing agent, and a sizing evaluation test was performed. Moreover, the blank example which does not use the surface sizing agent of this invention was made into the comparative example 10.

<< Example of sizing evaluation test for high-quality paper of surface sizing agent >>
(a) Manufacture of fine base paper To LBKP pulp slurry beaten to 450 ml (CSF), 10% light calcium carbonate, 0.5% sulfuric acid band and 0.5% cationized starch were added to the pulp. A fine base paper (basis weight 85 g / m ² ) was wet-made without using a sizing agent.
(b) Preparation of coating solution Each of the surface sizing agents of Examples 1 to 7 and Comparative Examples 1 to 9 was dissolved in a gelatinized solution of oxidized starch to obtain a surface sizing agent of 0.5% and oxidized starch of 6.0. % Coating solution was prepared.
In this case, as described above, in Example 4 and Comparative Example 4, first, a copolymer constituting one of the surface sizing agents of the present invention was produced, and when the coating liquid was prepared, the copolymer and In addition to the oxidized starch, amines constituting the other surface sizing agent of the present invention were mixed. The mixing ratio with respect to the total amount of constituent monomers of the copolymer of amines in Example 4 is 20%, and the mixing ratio with respect to the total amount of constituent monomers of the copolymers of amines in Comparative Example 4 is 15%. is there. In Example 4 or Comparative Example 4, the content of the surface sizing agent comprising an amine and a copolymer and the oxidized starch in the coating solution was as described above, the surface sizing agent being 0.5% and the oxidized starch being 6.0. %.
In Comparative Example 9, only amines were used as a surface sizing agent, and 0.08% of a surface sizing agent (dimethyl palmitylamine) was contained in a 6.0% oxidized starch coating solution.
Further, in Comparative Example 10, a coating solution containing 6.0% oxidized starch was used.
(c) Coating on high-quality base paper One-sided coating was applied to the above-mentioned high-quality base paper to give a liquid absorption of 20 g / m ² on both sides, and dried with a rotary drum dryer at 90 ° C for 90 seconds. A quality coated paper for measurement was obtained.
And about each quality coated paper (Examples 1-7, Comparative Examples 1-10), the sizing degree was measured based on the "paper Stichtite sizing degree test method" of JISP8122.

FIG. 2 shows the test results.
In Comparative Example 10 in which only the oxidized starch was applied, the sizing degree was 1 second, and in Comparative Example 9 in which only the amine (A) was used alone, it was 0 second. Further, the size of Comparative Example 7 in which amides were used in combination with the copolymer (B) of the present invention instead of amines was improved as compared with Comparative Example 9 containing only amines (A), but it was still at a low level. It was.
On the other hand, in Examples 1-7 in which the amines (A) and the cationic copolymer (B) having a specific composition were used in combination, the size properties were both high.
In Comparative Example 8 in which only the cationic copolymer (B) of the present invention was used alone, the size property was improved as compared with other Comparative Examples, but the coating concentration was not so high. It was inferior to ~ 7.
Therefore, it was confirmed that it is necessary to use amines and a copolymer having a specific composition in order to satisfactorily exhibit size characteristics with a coating amount that is not so large.

On the other hand, when a cationic copolymer and an amine are used in combination, the content ratio of the cationic monomer (a), the long-chain alkyl ester of (meth) acrylic acid (b), or the styrenes (c) is within an appropriate range. In Comparative Examples 1-2, Comparative Examples 4-5, and Comparative Example 6 that deviate from each other, the size properties were inferior to those of Comparative Example 7 in which amides and a copolymer were used in combination. Comparative Example 3 using a short-chain alkyl ester having 2 carbon atoms instead of a long-chain acrylic ester was similarly inferior.
As described above, in Examples 1 to 7 using the copolymer (B) in which the monomer components (a) to (c) are in an appropriate range, the evaluation of the size property was high.
Therefore, it has become clear that it is not sufficient to use amines and a cationic copolymer together in order to exert a good size, and it is necessary to use a cationic copolymer having an appropriate composition. .

Next, when Examples 1 to 7 are examined in detail, when a cationic copolymer having a specific composition and amines are contained, even if the amines are mixed before polymerization of the copolymer, polymerization of the copolymer is performed. It was confirmed that the effect of improving the sizing property did not change even if the mixture was mixed before quaternization later or after the quaternization of the copolymer. In addition, when the amines are mixed after the quaternization of the copolymer, the quaternized copolymer is mixed with the amines in the preparation stage of the coating liquid and the gelatinized aqueous solution of a water-soluble polymer (such as oxidized starch) is added. Even when mixed in, an excellent size improvement effect was shown (see Example 4).
Furthermore, as the amines (A) to be used in combination with the copolymer having a specific composition, any of monoamines, quaternary ammonium salts, polyvalent amines, and condensed polyamines of alkylamines and epichlorohydrins are effective. 7 was confirmed.

  Next, for each of the surface sizing agents obtained in the above Examples and Comparative Examples, a sizing evaluation test was performed on newsprint paper containing no internal sizing agent. Moreover, the blank example which does not use the surface sizing agent of this invention was made into the comparative example 11.

<< Example of sizing evaluation test for surface sizing agent on newspapers >>
(a) Manufacture of newspaper base paper A pulp slurry comprising at least 80% by weight of all pulp components of newspaper waste and mechanical pulp, 10% light calcium carbonate, 0.5% sulfuric acid band, and 0.5% cation The newspaper base paper (basis weight 45 g / m ² ) was wet-made without adding the internal starch and using the internal sizing agent.
(b) Preparation of coating solution Each of the surface sizing agents of Examples 1 to 7 and Comparative Examples 1 to 9 was dissolved in a gelatinized solution of oxidized starch to obtain a surface sizing agent of 0.4% and oxidized starch of 4.0. % Coating solution was prepared.
In this case, as described above, in Example 4 and Comparative Example 4, first, one copolymer constituting the surface sizing agent of the present invention was produced, and at the time of preparing the coating solution, the copolymer and In addition to the oxidized starch, the amines constituting the other of the surface sizing agent of the present invention were mixed. In Example 4 or Comparative Example 4, the coating of the surface sizing agent comprising the amines and copolymer and oxidized starch was performed. As described above, the content in the working solution is 0.4% of the surface sizing agent and 4.0% of oxidized starch.
In Comparative Example 9, only amines were used as a surface sizing agent, and 0.08% of a surface sizing agent (dimethyl palmitylamine) was contained in a coating solution of 4.0% oxidized starch.
Furthermore, in Comparative Example 11, a coating solution containing 4.0% oxidized starch was used.
(3) Coating on newspaper base paper Coat on each side of the newspaper base paper so that it has a liquid absorption of 16 g / m ² on both sides and dry it with a rotary drum dryer at 80 ° C for 90 seconds. A measuring newspaper was obtained.
For each newspaper (Examples 1 to 7, Comparative Examples 1 to 9 and 11), according to JAPAN TAPPI paper pulp test method No. 32-2 (paper-water absorption test method-part 2: dropping method), A water absorption test was performed with 5 μL of water, and the time (seconds) required for water absorption was measured to evaluate the superiority or inferiority of the size property.

FIG. 3 shows the test results.
Also in the test with this newsprint, Examples 1-7 showed the outstanding size property with respect to Comparative Examples 1-9 and 11 similarly to the test with the said quality paper.
That is, Comparative Example 9 which is a blank example using only amines, Comparative Example 7 where amides are used in combination with the copolymer of the present invention instead of amines, or only the copolymer of the present invention is used alone. In contrast to Comparative Example 8 used, Examples 1 to 7 are not only excellent in size but also include Comparative Example 6 of the conventional type mainly composed of styrene as a hydrophobic monomer, and components (a) to (c). It is the same in terms of sizing degree to Comparative Examples 1 and 2 and Comparative Examples 4 to 5 in which the content of C is not within the proper range, or Comparative Example 3 using a short chain ester instead of component (b). Showed superiority.
In addition, as in the above-described test example using fine paper, the size effect was clearly improved in Examples 1 to 7 regardless of the mixing time of amines into the copolymer and the type of amines.
As described above, the surface sizing agent of the present invention is used alone on the paper surface without combining with an internal additive sizing agent for high-quality paper or newspaper (that is, even for a base paper without an internal additive sizing agent). It became clear that an excellent sizing effect can be achieved simply by coating.

It is the table | surface which put together the monomer composition at the time of obtaining each copolymer of Examples 1-7 and Comparative Examples 1-7, the kind of amines, content, etc. It is a graph which shows the result of the sizing evaluation test of the quality paper (The comparative example 10 does not use a surface sizing agent) which applied the liquid containing each surface sizing agent of Examples 1-7 and Comparative Examples 1-10. . The table | surface which shows the result of the sizing evaluation test of the newspaper paper (Comparative example 11 does not use a surface sizing agent) which apply | coated the liquid containing each surface sizing agent of Examples 1-7 and Comparative Examples 1-9, 11 It is.

Claims (8)

Containing an amine (A) and a copolymer (B);
The copolymer (B) is
(a) 18-40% by weight of a tertiary amino group-containing monomer,
(b) (meth) 10 to 80% by weight of alkyl esters of C ₄ -C ₁₈ acrylic acid,
(c) a cationic surface size characterized by being a copolymer obtained by polymerizing styrenes in an amount of 0 to 70% by weight in the presence of a chain transfer agent to be quaternized or not quaternized. Agent. The amine (A) is at least one selected from the group consisting of amines having one or more C _{6 to} C ₂₂ substituents, ammonium salts, polyvalent amines, and polyamines by condensation reaction of alkylamines and epihalohydrins. The cationic surface sizing agent according to claim 1.   The amine (A) is mixed in a proportion of 0.01 to 30% by weight based on the total amount of the monomer components (a) to (c) of the copolymer (B). The cationic surface sizing agent described.   The cationic property according to any one of claims 1 to 3, wherein the tertiary amino group-containing monomer (a) is dialkylaminoalkyl (meth) acrylate and / or dialkylaminoalkyl (meth) acrylamide. Surface sizing agent.   Add the amines (A) to polymerize the monomer components (a) to (c), or polymerize the monomer components (a) to (c) and then add the amines (A) to quaternize or The cationic surface according to any one of claims 1 to 4, wherein the amine (A) is added after quaternization of the copolymer (B) without quaternization. Sizing agent.   The content of the amine (A) of claim 1 or 2 and the copolymer (B) of claim 1 or 4, or at least one selected from the group consisting of polysaccharides, polyvinyl alcohols and polyacrylamides The surface treatment method which coats the content which added the water-soluble polymer of this on the paper surface.   The cationic surface sizing agent according to any one of claims 1 to 5, or at least one water-soluble polymer selected from the group consisting of polysaccharides, polyvinyl alcohols, and polyacrylamides. Coated paper.   8. The coated paper according to claim 7, wherein the base paper is a paper containing no internal sizing agent or a neutral paper having a Steecht sizing degree of 2 seconds or less.

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