JPH0217680B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention exhibits a significantly improved size effect, has good stability, is capable of papermaking in the neutral range, and is suitable for both internal and external addition sizing (off-machine sizing). A new type of ketene dimer/carbamoyl lower alkyl starch mannisside quaternized product is available and useful for the sizing process of papers (a term that includes paperboards) that can exhibit excellent sizing effects. This invention relates to an aqueous dispersion or emulsion type paper sizing agent. More specifically, the present invention provides a ketene dimer and a quaternized product of a carbamoyl lower alkyl starch mannamide, which is a quaternized product which has not been described in the literature, in an amount of about 5 to about 50 parts by weight per 100 parts by weight of the dimer. The present invention relates to a paper sizing agent characterized in that it is an aqueous dispersion containing. Conventionally, many proposals have been known as sizing agents for paper manufacturing, and have also been put into practical use. Rosin-based sizing agents, which have been widely used as such sizing agents, exhibit sizing effects through acidic region papermaking using sulfuric acid band, but because of acidic region papermaking, the resulting product may deteriorate over time. , the complexity of pH adjustment during papermaking, problems with wastewater treatment, and problems with corrosion of paper machines and other metal equipment and components.
There are other inconveniences. Furthermore, as fillers, calcium carbonate, clay,
Attempts to use it as a substitute for talc, titanium oxide, etc. also have the disadvantage of being unsuitable due to the problem of carbon dioxide gas generation associated with papermaking in an acidic region. In order to avoid such troubles in papermaking in the acidic region, the use of fixing agents such as sulfuric acid bandate is omitted, and
Aiming for papermaking in the neutral range that improves the size effect,
Many studies and proposals have been made regarding the development of sizing agents suitable for such purposes. However, the reality is that a satisfactory sizing agent cannot be provided. For example, synthetic sizing agents for papermaking using acrylic resins in the neutral range are generally thermosetting, so they have the disadvantage of undesirably hardening the paper quality of the paper web produced.
Further, although the wet strength is improved, there is a disadvantage that when recovering the pulp material, the difficulty of disintegrating the waste paper is worsened, and the recoverability of the pulp material is deteriorated. Furthermore, many proposals regarding so-called ketene dimer-based sizing agents are known (for example, JP-A-52-110906; JP-A-52-110906;
−118010, JP-A-55-90700, JP-A-55-
No. 98997, JP-A-55-37639, JP-A-55-137296
number, etc.). However, conventional aqueous dispersion- or emulsion-type ketene dimer-based sizing agents have problems with mechanical, chemical, and/or stability over time, and various dispersants have been used to improve this problem. has been proposed. Furthermore, ketene dimer-based sizing agents using such dispersants in types and amounts that can provide practical stability have other technical problems such as a non-negligible reduction in sizing efficiency. will occur. The present inventors conducted research to provide a sizing agent free from such technical troubles. As a result, a quaternized product of the carbamoyl lower alkyl starch mannitz compound of the type disclosed in the earlier Japanese Patent Application No. 1-24161 (Patent Publication No. 1-24161), that is, a quaternized product of the formula However, in the formula, R ₁ and R ₂ each represent lower alkyl, R ₃ represents a cationic residue of a quaternizing agent,
X ^- represents an anion, m is 1 to 3, n' is the number of repeating units of the raw material starch or a lower number, and has a molecular weight corresponding to a reduced viscosity of about 0.1 to about 2.5. The aqueous dispersion or emulsion, which requires a combination of a quaternized product of a carbamoyl lower alkyl starch mannitz compound with a ketene dimer, is a unique paper-making process that combines practical stability and extremely good size effect. discovered that it can be used as a sizing agent. In addition, in the case of a combination of a nonionic surfactant, which is often used as a dispersant, and a ketene dimer in conventional ketene dimer-based sizing agents, the formed aqueous dispersion or emulsion tends to foam. However, in an aqueous dispersion or emulsion that requires a combination of a ketene dimer and a quaternized product of a carbamoyl lower alkyl starch mannicide, which has not been described in the literature, such inconveniences arise. It turns out that it can also be avoided. Furthermore, the aqueous dispersion or emulsion that requires the above combination can be used for papermaking in the neutral range, and can also be used for both internal addition sizing and external addition sizing, and exhibits significantly improved size effects. It was also found to have good stability. Therefore, an object of the present invention is to provide an excellent paper sizing agent. The above objects and many other objects and advantages of the present invention will become more apparent from the following description. The ketene dimer utilized in the sizing agent of the present invention is well known and commercially available. Regarding such ketene dimer, for example, JP-A-52-118010, JP-A-55-90700, JP-A-55
-98997, JP-A-55-37639, etc., and can be used in the present invention. An example of such a ketene dimer is the following formula: However, in the formula, R ¹ and R ² each represent a saturated and unsaturated alkyl group having at least 8 carbon atoms, a cycloalkyl group having at least 6 carbon atoms, an aryl group, an aralkyl group, and an alkali group. An example is a ketene dimer represented by the following, which represents a group selected from the group consisting of: A specific example of such a ketene dimer is:
Octyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, eicosyl, decosyl, tetracosyl, decenyl, tridecenyl, hexadecenyl, eicosenyl, phenyl , benzyl, phenylethyl, tert-butylphenyl, octylphenyl, nonylphenyl, dodecyl phenyl,
Nonylcyclopropyl, dodecylcyclohexyl, nonylcyclohexyl, β-naphthyl, cyclohexyl-ketene dimers montanic acid, naphthenic acid, △ ^9,10 -decylenic acid, △ ^9,10 -dodecylenic acid, palmitoleic acid, Ketene dimers derived from oleic acid, ricinoleic acid, linoleic acid, linolenic acid, eleostearic acid, etc.; coconut oil, babassu oil, palm kernel oil, palm oil, olive oil, peanut oil, rapeseed oil, beef tallow, Examples include ketene dimers derived from natural fatty acid mixtures contained in lard (leaf lard), whale oil, etc.; arbitrary mixtures thereof; and the like. Among these, C ₈ to C ₃₀ (saturated or unsaturated)
Preferred examples include alkylketene dimers having an alkyl group. The sizing agent of the present invention is a ketene dimer as described above.
It contains from about 5 to about 50 parts by weight per 100 parts by weight of a quaternized carbamoyl lower (preferably _C1 - _C4 ) alkyl starch mannicide. The quaternized carbamoyl lower alkyl starch mannicide can be produced by the method described in detail in the aforementioned Japanese Patent Publication No. 1-24161. For example, the quaternized product is described in Japanese Patent Publication No. 45-7759,
Carbamoyl lower alkyl starch which can be produced by known methods disclosed in JP-A No. 49-99177, US Pat. No. 2,938,026, US Pat. It can be produced by subjecting a carbamoyl lower alkyl starch mannicide obtained by mannification using a known method disclosed in Publication No. 2312450 and the like to a quaternization reaction. The quaternization reaction is carried out in a slurry of carbamoyl lower (preferably _C1 - _C4 ) alkyl starch mannissa in an aqueous medium, preferably in the presence of a water-soluble inorganic acid ammonium salt, at a pH of about 6 to about 8. This can be carried out by using a quaternizing agent under these conditions. Examples of water-soluble inorganic acid ammonium salts include ammonium chloride, ammonium sulfate, ammonium carbonate, ammonium nitrate, and ammonium chloride is particularly preferred. or,
As the PH regulator, it is preferable to use an inorganic acid, particularly phosphoric acid. The reaction temperature is preferably about room temperature to about 70°C, more preferably about 30° to about 60°C. The reaction time may be, for example, about 20 minutes to about 90 minutes. The amount of water-soluble inorganic ammonium salt to be used is about 60 to about
An example of the amount used is 120 mol%. In addition, the amount of quaternizing agent used is approximately 80% based on the secondary amine.
An example of the amount used is 140 mol % to about 140 mol %. When an isolated carbamoyl lower alkyl starch mannissa is used, the reaction is preferably carried out in the presence of the secondary amine in an amount of about 50 to about 100 mol % based on the mannissa. The raw material carbamoyl lower alkyl starch mannitz compound normally exhibits alkalinity due to the secondary amine used in excess in the mannitz reaction during its production, but in the quaternization reaction, this There is no need to neutralize
Moreover, neutralization is rather undesirable. If such a mannification reaction product system is stored for a long time, it will partially undergo hydrolysis, so it is better to avoid long-term storage and subject it to the quaternization reaction. Also, during the quaternization reaction,
In order to maintain stability, for example, ammonium chloride and phosphoric acid are added to a slurry of carbamoyl lower alkyl starch mannissa, and then a lower alcohol is added simultaneously with the addition of the quaternizing agent or as soon as possible after the addition of the quaternizing agent. It is preferred for the formation of good quaternized cation-modified starch. Examples of quaternizing agents used in the production of quaternized carbamoyl lower alkyl starch mannicides used in the sizing agent of the present invention include di-lower alkyl sulfates such as dimethyl alkyl sulfate and diethylalkyl sulfate; for example, benzyl chloride; ,
Dibenzyl halides such as benzyl bromide, benzyl iodide; Epihalohydrins such as epichlorohydrin, epipromohydrin, epiiodohydrin; Lower alkyl halides such as methyl chloride, methyl bromide, ethyl chloride, ethyl bromide; Examples include lower alkylene oxides such as ethylene oxide and propylene oxide. The quaternized product of carbamoyl lower alkyl starch mannitz compound used in the sizing agent of the present invention is a cationic dispersant that has not been previously described in the literature, and is a cationic dispersant that has the formula The -OH group of the primary alcohol of the repeating unit of starch that can be represented by (however, it is not necessary for all of the n units) is the following group, However, in the above, n is the number of repeating units of the raw material starch, m is 1 to 3, preferably 2,
R ₁ and R ₂ each represent a lower alkyl, preferably methyl or ethyl, and R ₃ represents a cationic residue of the quaternizing agent, such as a lower alkyl group, a benzyl group, an epoxy group, a lower alkyl halide group,
represents a lower alkylene oxide group, and X ^-
represents an anion, and is a quaternary cation-modified starch converted to , and can be represented by the following formula. However, in the formula, m, R ₁ , R ₂ and R ₃ are the same as described above, X ^- represents an anion, and n' is the number n of repeating units of the raw material starch or a number less than n. The above-mentioned quaternized compound of carbamoyl lower alkyl starch mannissa used in the sizing agent of the present invention is water-soluble and has a reduced viscosity of about 0.1 to 0.1% as measured in a 0.1% by weight solution of 1/10N NaCl water. about
However, in the sizing agent of the present invention, the degree of cationization is about 0.8 to about 1.5.
More preferably, about 1 to about 1.3 quaternized compounds are used. The sizing agent of the present invention comprises a ketene dimer as described above and a carbamoyl lower alkyl starch as described above in an amount of about 5 to about 50 parts by weight, preferably about 10 to about 30 parts by weight per 100 parts by weight of the dimer. It is an aqueous dispersion (or emulsion) containing a quaternized compound as an essential combination component. This papermaking sizing agent may further contain other additives. Such additives include
Examples include other cationic and/or nonionic dispersants, organic solvents, and the like. Examples of the other dispersants mentioned above include (a) epichlorohydrin; (b-1) a polyalkylene polyamine having two primary amine groups and at least one secondary or tertiary amine group; (b-2) Consisting of a water-soluble reaction product between a dicarboxylic acid and at least one amine selected from the group consisting of (b-1) a polyamide derived from the above-mentioned (b-1) polyalkylene polyamide, and (b-3) a water-soluble dialkylamine. Cationic dispersants; urea-formalin resins; cationic dispersants; and polyvinyl alcohol, glue, oxidized starch, polyoxyalkylene alkyls, polyoxyalkylene alkyl-aryl ethers, or their corresponding mono- or di- Esters, such as polyoxyethylene and/or propylene alkyl and alkyl-containing from 5 to 20 oxyethylene and/or oxypropylene units.
Aryl ether or ester (for example, alkyl group has 8 to 20 carbon atoms, aryl group is phenyl)
Examples include nonionic dispersants such as. The amount of such other cationic and/or nonionic dispersants to be used is about 30 parts by weight or less, for example about 5 to about 30 parts by weight, more preferably about 10 to about 30 parts by weight, based on 100 parts by weight of the ketene dimer. An example of the amount used is about 20 parts by weight. These other cationic and/or nonionic dispersants are used in a secondary amount of about 5 to about 10% by weight based on the amount of the quaternized compound of the carbamoyl lower alkyl starch mannichide used. good. Since excessive amounts of these other cationic and/or nonionic dispersants cause size effects and deterioration of stability, they are preferably used in secondary amounts relative to the quaternized compound. The organic solvent is preferably a non-reactive solvent with a medium boiling point or above, such as kerosene, trichlorethylene, saturated hydrocarbon solvents [for example, Isopar
(Product name) series solvent; ESSO Oil Co., Ltd. product], etc. are examples. The amount used can be selected as appropriate, but it is preferably about 50 parts to about 500 parts based on the ketene dimer.
It mainly serves to stabilize the sizing agent and promote the sizing effect. The sizing agent of the present invention is in the form of an aqueous dispersion or emulsion containing the aforementioned ketene dimer, a quaternized product of carbamoyl lower alkyl starch mannicide, water, and optionally other additives. Such an aqueous dispersion or emulsion can be formed, for example, as follows.
Dissolve the quaternized product of carbamoyl lower alkyl starch mannitz compound in hot water of about 30 to about 40°C, and separately, heat and melt the ketene dimer, and then add the dissolved quaternized product and sufficient stirring conditions. Mix to form an emulsion, then pass through a homogenizer at 500Kg/cm ² to form a complete emulsion. Other cationic or nonionic dispersants such as those exemplified above may be mixed with either the quaternized product or the ketene dimer. Furthermore, when an organic solvent is used, it is preferable to mix it with the ketene dimer. Generally, the order of addition of each drug, the mixing ratio, etc. can be arbitrarily determined and are not particularly limited, and ordinary emulsion technology can be appropriately employed. The sizing agent of the present invention, which can be obtained as described above, can be used in a wide pH range of about 4.5 to about 10, and can be suitably used for papermaking in the neutral range, which is the aim of the industry. Furthermore, with the use of the quaternized compound, improvements in water properties, paper strength, filler retention, fine fibers in the pulp contained in the prepared paper stock raw materials, improvement in the retention of other compounding agents such as colorants, etc. Improvement effects are also expected. The sizing agent of the present invention can be used for both internal addition sizing and external addition sizing. For example, in any process suitable to achieve the desired size effect before feeding into the paper machine, the paper stock may contain at least pulp and filler, and may also contain conventional materials other than filler. Prepared paper stock, which optionally contains additives such as other sizing agents, fixing agents, paper strength agents, colorants, etc., is the prepared paper stock immediately before dilution to the final consistency to be introduced into the paper machine. It can be added at any stage leading up to. Filler, as is well known in the paper industry, is a white, opaque substance that is added to paper raw materials to improve paper surface roughness, poor printability, poor whiteness, etc. substantially insoluble in water;
A chemically almost neutral filling powder made of white clay,
It is a white solid powder represented by kaolin, agarite, talc, calcium carbonate, magnesium carbonate, lime sulfate, barium sulfate, zinc sulfide, titanium oxide, etc. In order to perform internal addition sizing in a neutral range papermaking mode using the sizing agent of the present invention, for example, about 0.01 to about 5% by weight, more preferably about 0.05 to about 2% by weight, based on the dry weight of the pulp in the above raw material. By weight%, the paper can be made under pH conditions of about 6 to about 10, more preferably about 7 to about 9. In addition, when using the sizing agent of the present invention, a cationic dispersant made of a water-soluble reaction product of epichlorohydrin and amines as exemplified above or a quaternary carbamoyl lower alkyl starch mannamide used in the sizing agent of the present invention may be used. from about 0.005 to about 3% by weight, based on the dry weight of the pulp, preferably about
It can be added in an amount of about 0.01 to about 1% by weight. Furthermore, when externally adding sizing, it is possible to perform surface sizing by applying the same amount to the paper web using known means such as coating, spraying, and impregnating in any process after papermaking in the same amount as exemplified for internally adding sizing. can. Next, the present invention will be explained in detail with reference to examples, but these examples are not intended to limit the scope of the present invention in any way. The following percentages are based on weight unless otherwise specified. Comparative example 1 C ₁₈ ketene dimer (stearyl ketene dimer)
120 parts, commercially available cationic starch (cationic equivalent 0.4)
Prepare an emulsified dispersion using 30 parts and water and heat at 80°C.
Homogenize with a homogenizer (500Kg/cm ² ) to reduce the total content of ketene dimer and cationic starch to 15
Comparative Example 1 sizing agent (1b) in weight percent was prepared. Comparative Example 2 A ketene dimer was prepared in the same manner as in Comparative Example 1, except that 10% by weight of dimethylamine/epichlorohydrin resin derived from 192 g of 50% dimethylamine and 197 g of epichlorohydrin was added to the commercially available cationic starch. Comparative Example 2 sizing agent (2b) having a total content of 15% by weight of starch and cationic starch was produced. Comparative Example 3 Comparative Example 1 except that 10% by weight of dimethylamine/diethylenetriamine/epichlorohydrin resin derived from 40g of 50% dimethylamine, 3.8g of diethylenetriamine, and 49.6g of epichlorohydrin was added to the commercially available cationic starch. In the same manner, Comparative Example 3 sizing agent (3b) having a total content of ketene dimer and cationic starch of 15% by weight was produced. Comparative Example 4 The same procedure as in Comparative Example 1 was carried out except that 20% by weight of polyvinyl alcohol (completely saponified type) was added to the ketene dimer, and the total content of ketene dimer and cationic starch was 15% by weight. Comparative Example 4 A sizing agent (4b) was produced. Example 1 In Comparative Example 1, a ketene dimer and a quaternized product were prepared in the same manner as in Comparative Example 1, except that a quaternized product (cation equivalent: 1.4) of carbamoylethyl starch mannichide was used instead of a commercially available cationic starch. Total content 15
Example 1 sizing agent (1a) in weight percent was obtained. Example 2 In the same manner as in Example 1, except that 10% by weight of dimethylamine/epichlorohydrin resin was further added to the quaternized product, the total content of ketene dimer and quaternized product was 15% by weight. Example 2 A sizing agent (2a) was obtained. Example 3 In the same manner as in Example 1, except that 10% by weight of dimethylamine/diethyltolyleneamine/epichlorohydrin resin was further added to the quaternized product, the total content of ketene dimer and quaternized product was Example 3 sizing agent (3a) was obtained in an amount of 15% by weight. Example 4 In the same manner as in Example 1, except that 20% by weight of polyvinyl alcohol (completely saponified type) was further added to the ketene dimer, the total content of ketene dimer and quaternized product was 15 Example 4 sizing agent (4a) in weight percent was prepared. Comparative test of size effect and stability: - Internal addition sizing tests were conducted using the sizing agents obtained in Examples 1 to 4 and Comparative Examples 1 to 4. 1% pulp slurry (L-BKP, Canadian Standard Freeness 380ml),
Add the above sizing agent to pulp at 0.10% and 0.20%
After adding at a ratio of (non-volatile content equivalent), the basis weight was
The paper was made to have a weight of 60±1 g/m ³ . The obtained wet paper was dehydrated at 4Kg/ ^cm3 for 1 minute, dried in a rotary dryer (105℃) for 3 minutes, and then the paper stock was dried at 20℃ and 65℃.
Humidity was controlled for 24 hours at %RH. The Steckist sizing (TIS.P8122) of these paper stocks was measured and shown in Table 1 below. The stability of the emulsion was also compared when each size solution was stored at 5°C and 50°C for one week.

[Table] Comparative Example 5 After controlling the pH by adding 8 g of 15% ammonia water to 81 g of 37% formalin solution, 20 g of urea was added and reacted at 80°C, then 5 g of dimethylaniline and 4 g of concentrated sulfuric acid were added. A urea-formalin resin cationic dispersant was formed by condensation at pH 2.5. A comparison was made in the same manner as in Comparative Example 1, except that the above dispersant was further added in an amount of 10% by weight based on the amount of commercially available cationic starch used, and the total content of ketene dimer and cationic starch was 15% by weight. Example 5 A size agent (5b) was obtained. Example 5 In the same manner as in Example 1, except that the same urea-formalin resin cationic dispersant used in Comparative Example 5 was further added in an amount of 10% by weight based on the quaternized product, ketene dispersant was prepared in the same manner as in Example 1. Total content of polymers and quaternized substances
15% by weight of Example 5-1 sizing agent (5a) was obtained. Also, Example 5-1 except that the same amount of saturated hydrocarbon solvent (trade name Isopar M, aniline point 85°C, distillation range 207-257°C) as the ketene dimer used was used.
Example 5-2 sizing agent (5a
- Obtained a). The degree of size was measured in the same manner as in Table 1, and Table 2
It was shown to. Regarding stability, Table 2 shows the stability when stored for 2 weeks.

【table】

Claims (1)

[Claims] 1. A ketene dimer and about 5 to about 50 parts by weight per 100 parts by weight of the dimer, However, in the formula, R ₁ and R ₂ each represent lower alkyl, R ₃ represents a cationic residue of a quaternizing agent,
X ^- represents an anion, m is 1 to 3, n' is the number of repeating units of the raw material starch or a lower number, and has a molecular weight corresponding to a reduced viscosity of about 0.1 to about 2.5. 1. A sizing agent for paper manufacturing, which is an aqueous dispersion containing a quaternized carbamoyl lower alkyl starch mannitz compound. 2. The sizing agent according to claim 1, wherein the ketene dimer is an alkylketene dimer having a _C8 to _C30 alkyl group. 3 The cationic colloidal equivalent of the quaternized carbamoyl lower alkyl starch mannitz compound is about 0.8.
2. The sizing agent of claim 1, wherein the size is from about 1.5 to about 1.5.