JP2580653B2 - Papermaking sizing agent - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a papermaking sizing agent, and more particularly to a papermaking sizing agent capable of exhibiting a sizing effect in a short time.

[Conventional technology]

Various sizing agents such as rosin have been used as sizing agents for papermaking, and recently, a ketene dimer made from a fatty acid known as a neutral sizing agent has been particularly awarded.

This ketene dimer has a unique molecular structure containing a four-membered ring having a 2-oxetanone structure in the molecule, which is obtained by converting a fatty acid into an acid chloride, adding a tertiary amine, and performing a dehydrochlorination reaction. is there. At the time of sizing, this ketene dimer is preliminarily emulsified and dispersed in water using an appropriate dispersing agent, and is added to a pulp solution for papermaking so that the ketene dimer is uniformly fixed to pulp fibers. ing.

Regarding the above emulsion, for example, JP-A-57-101095, JP-A-57-112497, JP-A-57-139596, JP-A-60-88196, JP-A-60-99097 Gazette,
JP-A-60-104599 and the like, by selecting the kind of resin acid and the kind of dispersant as a raw material of ketene dimer, to improve the dispersion stability and size effect of the emulsion, etc. Is disclosed.

[Problems to be Solved by the Invention] However, the sizing agent for paper making using this kind of ketene dimer has a drawback that the effect of the sizing treatment is not rapidly exhibited, that is, the rise of the sizing effect is poor.
For this reason, many problems, such as productivity and quality control, have been caused, for example, it cannot be shipped unless it is preserved for several days after paper making, and it is difficult to continuously perform coating after paper making in the case of coated paper. For this reason, overcoming such a problem is one of the technical problems in the sizing agents disclosed in each of the above publications.

In view of such circumstances, the present invention does not have the above-described problems by using a compound having a 4-membered ring having a 2-oxetanone structure in a molecule different from the conventional ketene dimer. The purpose of the present invention is to obtain a papermaking sizing agent having a good size effect.

[Means for solving the problem]

The present inventors have conducted intensive studies to achieve the above object, and as a result of using a ketene multimer produced from dimer acid as a compound having a 4-membered ring having a 2-oxetanone structure in the molecule. As a result, the present inventors have found that a paper sizing agent having a good rise in size effect can be obtained, thereby completing the present invention.

That is, the present invention relates to a sizing agent for papermaking, comprising a ketene polymer produced from dimer acid as a raw material and a dispersant as active ingredients.

[Structure and operation of the invention]

The dimer acid used as a raw material in the present invention is obtained by thermally polymerizing an unsaturated fatty acid having usually 16 to 22 carbon atoms using a catalyst such as clay, and includes a dimer acid as a main component. In addition, high polymers such as monocarboxylic acids and trimer acids are also included.

Such dimer acids are readily available as commercial products, examples of which include Haridimer 250, Haridimer 3
00 [manufactured by Harima Kasei Kogyo Co., Ltd.]; UNIDIME 1
4. Unidim 22 [manufactured by Union Kamp Co., Ltd.]; EMPOL 1014, EMPOL 1018, EMPOL 102
2 (manufactured by Emery Corporation); Versadim 216 (manufactured by Henkel Corporation). In the present invention, these commercially available hydrogenated products may be used.

The ketene multimer of the present invention can be synthesized according to a conventionally known method except that the above dimer acid is used as a raw material.
For example, after converting one or more of the above dimer acids into an acid chloride using phosphorus trichloride, phosgene, or the like,
The ketene multimer of the present invention can be obtained by performing a dehydrochlorination reaction using a tertiary amine such as trimethylamine, triethylamine or tripropylamine.

The obtained ketene multimer is composed of a mixture in which the dimer acid as a raw material contains a monocarboxylic acid or a trimer acid as described above, and the dimer acid as a main component contains two carboxyl groups in one molecule. Therefore, unlike a ketene dimer produced from a conventional fatty acid as a raw material, a ketene dimer containing one or two 4-membered rings having a 2-oxetanone structure in one molecule is mainly used. The composition contains various multimers such as a ketene tripler containing two or more of the above four-membered rings, which seems to be a good result in improving the rise of the size effect aimed at by the present invention. It is.

In synthesizing such a ketene multimer, a fatty acid having 4 to 30 carbon atoms is used in combination with dimer acid as a raw material component, and after a mixture of both is acid chlorided, a dehydrochlorination reaction is performed with a tertiary amine. Is also good. in this case,
The mixing ratio of the dimer acid and the above fatty acid is preferably such that the dimer acid accounts for 1% by weight or more, preferably 10% by weight or more in the total amount of both. If the amount of dimer acid is too small, the effect of the present invention is impaired, which is not preferable.

Alternatively, a ketene multimer of dimer acid and a ketene dimer of a fatty acid similar to the above may be separately synthesized, and then both may be used as a mixture. In this case, the mixing ratio is such that the ketene multimer of dimer acid is 1% by weight or more, preferably 10% by weight or more in the total amount of both. If the amount of the dimer acid ketene multimer is too small, the same problem as described above occurs, which is also not preferable.

In the present invention, a dispersant for emulsifying and dispersing the ketene polymer in water is used together with the ketene polymer. As the dispersant, any one that does not react with the ketene multimer or does not adversely affect the size effect may be used. However, it is usually preferable to use a cationic dispersant in consideration of the adsorptivity to pulp fibers. .

As the cationic dispersant, any of various dispersants known as suitable for the above-described conventional ketene dimer can be used.
E dispersants.

B) Cationic starch obtained by tertiary or quaternary use of starch derived from corn or potato using 2-diethylaminoethyl chloride, 2.3-epoxypropyltrimethylammonium chloride or the like.

B) A reaction product of a water-soluble long-chain aminopolyamide and epihalohydrin.

C) A quaternized alkylalkyl halide of a homopolymer of dialkylaminoalkyl (meth) acrylate or a copolymer thereof with acrylamide.

D) A homopolymer of dimethylallylammonium chloride or a copolymer of dimethylallylammonium chloride and styrene, or an epihalohydrin modified product thereof.

E) A polyamine having two or more primary amino groups and one or more secondary or tertiary amino groups in one molecule such as diethylenetriamine is condensed with dicyandiamide or cyanamide and then reacted with epihalohydrin. Reaction product.

The amount of these dispersants used is usually 1 to 50% by weight, preferably 5 to 30% by weight, based on the total amount with the ketene polymer. If the amount is too small, a sufficient dispersing effect cannot be obtained, and if it is too large, the sizing effect may be impaired.

The papermaking sizing agent of the present invention contains the above ketene multimer and dispersant as essential components, and usually, as in the case of the conventional ketene dimer, the ketene multimer is previously dissolved in water with a dispersant. It is provided for use as an emulsified emulsion. If necessary, various surfactants, polymer dispersants and the like may be added to the emulsion as a dispersing aid. The concentration of the active ingredient (all the above-mentioned components) in such an emulsion is usually 10
About 40% by weight.

In order to perform sizing using the papermaking sizing agent of the present invention, for example, a papermaking pulp solution containing pulp fibers may be added with a sizing agent comprising the above-mentioned emulsion, and then papermaking may be performed by a conventional method. The amount of the sizing agent used at this time may be such that the effective ingredient is usually 0.05 to 0.5% by weight based on the pulp.

In the sizing treatment, in order to improve the fixability of the sizing agent to pulp fibers, fixing agents similar to those conventionally used in pulp solutions, for example, cationic starch, cationized cellulose, polyamide-shrimphalohydrin type Needless to say, a polymer, polyethyleneimine, polyvinylpyridine or a quaternary product thereof, polydimethylaminoethyl methacrylate or a quaternary product thereof, or a copolymer of such a cationic monomer and acrylamide can be added.

〔The invention's effect〕

As described above, the paper-making sizing agent of the present invention has a good rise in size effect by using a ketene multimer produced from dimer acid as one of the active ingredients, and has a short time after sizing. Since a practical size effect can be exhibited, problems such as productivity and quality control as in the related art can be avoided.

〔Example〕

Next, examples of the present invention will be described in more detail. In the following, “%” means “% by weight”.

Examples 1 to 7 Seven kinds of ketene multimers shown in Table 1 and dispersants A to D were combined at a predetermined weight ratio, and these were combined at a total concentration of 20.
It was added to water and emulsified and dispersed to give a weight% (concentration used during sizing) to prepare seven types of papermaking sizing agents of the present invention.

Among the ketene multimers shown in Table 1, the ketene multimer of Haridimer 250 of Example 1 was synthesized by the following method. Each of the ketene multimers of Examples 3 to 7 was synthesized in the same manner as described above except that the types of the raw material components were changed. In Example 2, a mixture of a ketene multimer synthesized in the same manner as described above and a ketene dimer of a fatty acid was used. As the dispersants A to D shown in Table 1, the following commercially available products or synthetic products were used.

<Ketene multimer of Haridimer 2500> In a four-necked flask, Haridimer 250 (acid value 19
5) Add 575 g, add 115 g of phosphorus trichloride (chlorine is 1.25 times equivalent to one carboxyl group of dimer acid) while adjusting the temperature to 50 to 60 ° C., stir and heat for 1 hour. . Thereafter, stirring was stopped, heating was stopped, and the mixture was allowed to stand for 3 hours to obtain 550 g of dimer acid chloride in the upper layer.

Next, 500 g of the above dimer acid chloride and 1,000 g of toluene were put into a three-necked flask of 3, and cooled to 20 to 40 g.
At 25 ° C., a mixture of 182 g of triethylamine (2.2 equivalents to dimer acid chloride) and 500 g of toluene was added dropwise over 2.5 hours, and the mixture was heated to 35 ° C. and aged for 2.5 hours.

Next, the temperature was raised to 50 ° C., and 400 g of a 50 ° C. dilute hydrochloric acid aqueous solution containing 6.5 g of hydrogen chloride was added. The toluene was distilled off from the toluene solution of the upper layer to obtain 430 g of a ketene polymer of dimer acid.

<Dispersant A> Cationic starch; trade name CATO manufactured by Oji National Co., Ltd.
15 <Dispersant B> A reactant obtained by reacting 1.2 mol of epichlorohydrin with a condensate of 1 mol of diethyltriamine and 1 mol of dicyandiamide <Dispersant C> Copolymer of acrylamide and 2-diethylaminoethyl methacrylate in a weight ratio of 7: 3 <Dispersant D> Mixture of cationic starch (same as that of dispersant A) and ligninsulfonic acid at a weight ratio of 10: 1 Comparative Examples 1 to 3 Three kinds of ketene dimers shown in Table 1 and dispersant C , D were prepared in the same manner as in Examples 1 to 7, except that a predetermined weight ratio was used.

A size effect test was performed by the following method using each of the paper sizing agents of Examples 1 to 7 and Comparative Examples 1 to 3. The results were as shown in Table 2 below.

<Size effect test> LBKP (Canadian Standard Freeness 380 ml) was used as the test pulp, and cationic starch (commercially available) was used as a fixing agent at 0.2% of the pulp. The amount of each sizing agent added (active ingredient) Was set to 0.1% with respect to the pulp, and the paper was produced under the following conditions. The sizing degree (seconds) of the obtained paper was measured immediately after the paper making and one day later by the Stequich method (JIS P-8122).

Second build: Tappy round hand machine Press: 3.5 kg / cm ² × 5 minutes Drying: Rotary dryer, 100 ° C × 90 seconds Weighing: 60 g / m ² From Table 2 above, the papermaking sizing agents of Comparative Examples 1 to 3 have poor rise in size effect and a low final sizing degree, but the papermaking sizing agents of the present invention of Examples 1 to 7
It can be seen that the rise of the size effect is good, and the final sizing degree is much better than that of the comparative example.

Claims (1)

(57) [Claims] 1. A sizing agent for papermaking, comprising as active ingredients a ketene multimer produced from dimer acid as a raw material and a dispersant.