JP3225097B2 - Transfer paper for electrophotography - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic transfer paper having improved size and electrophotographic suitability. More specifically, the present invention relates to an electrophotographic transfer paper excellent in size, toner fixability, and multifeed.

[0002]

2. Description of the Related Art In recent years, the use of calcium carbonate as a filler to improve whiteness and opacity, and to improve the storage stability of paper, and the like, has increased the production of transfer paper for electrophotography using neutral papermaking. ing. Also, in an electrophotographic copying machine using a positive polarity toner, a high background (when the filler in the paper powder adhering to the photoreceptor in the transfer process is mixed into the developer in the developing section, the toner and the filler have opposite polarities) , Aggregates are developed on non-image areas), and triboelectric charging as countermeasures against phenomena called deletion (a normal electrostatic latent image cannot be obtained due to a decrease in electrical resistance of the photoconductor in a dark place). Has a positive polarity, and the use of calcium carbonate having high surface electric resistance under high humidity conditions has been proposed (Japanese Patent Publication No. 63-40 / 1988)
No. 312, and Japanese Patent Publication No. 2-54543).

[0003] An internal sizing agent is used in electrophotographic transfer paper for the purpose of improving the sizing property mainly on writing characteristics, whereas the conventional acidic rosin sizing agent is used when producing paper under neutral conditions. Although it exhibited its performance in an acidic atmosphere and in the presence of a sulfate band, the rosin was eluted and a competitive reaction between the sulfate band and calcium carbonate occurred, so that it could not be used.

[0004] Instead of this, an internal sizing agent generally called a neutral sizing agent has been used. The neutral sizing agent referred to herein is an alkyl ketene dimer (hereinafter, AKD)
Abbreviated), alkenyl succinic anhydride (hereinafter, ASA)
Abbreviated). AKD takes advantage of the characteristics of obtaining excellent sizing properties with ease of handling or addition of a small amount, and ASA has been used taking advantage of the characteristics of good rise of sizing properties.

However, when AKD or ASA is used as a sizing agent for electrophotographic transfer paper, if the amount of the sizing agent added is increased for the purpose of increasing the sizing degree, the surface energy of the paper decreases, and the electrophotographic method , There is a tendency that the fixability of the toner transferred by the copying machine is deteriorated. Also, when the amount of the sizing agent added is increased by using AKD to increase the degree of sizing, the friction coefficient of the paper is reduced, and the paper is liable to slip. As a result, there is a problem that double feeding occurs in a copying machine. . As measures against these problems, reduction of the amount of AKD or ASA added, combined use with a cationic polymer type neutral sizing agent represented by a styrene-dimethylaminoether (meth) acrylate-epihalohydrin modified product (Japanese Patent Application Laid-Open No. 132789, and JP-A-57-11249
7) and an increase in the amount of surface-size starch applied.

[0006]

As a technique which can be applied to obtain an electrophotographic transfer paper excellent in size, toner fixability and double feeding, reduction of the addition amount of AKD or ASA as described above is known. , A combination with a cationic polymer type neutral sizing agent, and an increase in the amount of surface size starch applied. However, when the amount of AKD or ASA added is reduced, paper having a sufficient degree of sizing cannot be obtained although the fixability of the toner is good. Further, the combined use of the cationic polymer type with a neutral sizing agent has a problem that poor disintegration of broke and a decrease in the fluorescence intensity of the fluorescent dye remain. On the other hand, when the amount of starch adhering to the surface increased, the curl of the paper deteriorated, and transfer paper for electrophotography of sufficient quality could not be obtained in any case.

Accordingly, an object of the present invention is a neutral paper,
Another object of the present invention is to provide an electrophotographic transfer paper excellent in size, toner fixing property, and double feeding.

[0008]

In order to solve the above-mentioned problems, the present inventors have intensively studied a transfer paper for electrophotography which is a neutral paper and has excellent size, toner fixability, and multifeed. As a result, containing calcium carbonate as a filler,
It has been found that when an anionic neutral rosin sizing agent is used as an internal sizing agent, a remarkable sizing degree and electrophotographic aptitude that cannot be achieved by known techniques can be obtained, and the present invention is completed. It has been reached.

The neutral rosin sizing agent referred to in the present invention is p
Emulsified rosin sizing agent emulsified with various surfactants or water-soluble polymers used in the neutral region of H6-9. Here, as the rosin substance, gum rosin, wood rosin, tall oil rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, aldehyde modified rosin, rosin ester and other rosins, furthermore, the rosin and acrylic acid, maleic anhydride Examples of the heat-reacted product with an α, β-unsaturated carboxylic acid such as an acid, fumaric acid, and itaconic acid can be given, but in order to suppress the elution of a rosin substance in a neutral region, polymerization, insolubilization treatment such as water resistance is performed. be able to.

[0010] The ionicity of the neutral rosin sizing agent can be selected from anionic and cationic types depending on various surfactants or water-soluble polymers used during emulsification. In the present invention, various anionic, nonionic, cationic or amphoteric retention enhancers conventionally used, polyethylene oxide, polyamide resin, hydrophilic cross-linked polymer particle dispersion or the like or colloidal with its derivatives or denatured products As a result of examining a retention system in which compounds such as silica and bentonite are used in combination as appropriate, an anionic neutral rosin sizing agent and a cationic or amphoteric hydrophilic crosslinked polymer particle dispersion or a derivative or modified product thereof A yield improver with one of the constituent elements,
Alternatively, it was confirmed that a remarkable size effect was obtained when the yield system was combined.

For the purpose of expressing the sizing properties of the neutral rosin sizing agent, a polyvalent metal compound of Al (for example, a sulfate band, polyaluminum chloride, polyaluminum silicate sulfate, sodium aluminate, etc.) is blended. Of course.

The mechanism by which the anionic neutral rosin sizing agent can exhibit sizing properties in the neutral papermaking of the present invention is as follows: the anionic neutral rosin sizing agent is formed on the anionic pulp fiber via a water-soluble cationic polymer such as cationic starch. It is presumed that the neutral rosin sizing agent is fixed and reacts with aluminum ions on the dryer to develop sizing properties. Also,
It is considered that the retention aid improves the sizing property by the effect of collecting the sizing agent fixed to the fine fibers and the free sizing agent.

In the present invention, the rosin sizing agent is characterized in that the amount of rosin compounded in the paper increases and the coefficient of friction of the paper increases. No sliding occurs due to the improvement, and the so-called double feeding problem in which a plurality of transfer sheets are fed on a copying machine is solved. Furthermore, in the present invention, by performing neutral papermaking, calcium carbonate can be blended as a filler, so that the coefficient of friction of the paper, and the controllability are significantly improved, and, in the past, the high background, which had contradictory characteristics, and the release. The so-called phenomenon problem can be solved at the same time.

The pulp used in the present invention includes NBKP, LBKP, NBSP, LBSP, GP,
Waste paper pulp may be used in addition to TMP. In use, they are mixed and used at a ratio according to several purposes. The mixing ratio of waste paper pulp in the whole pulp is preferably 40% or less from the viewpoint of curling after transfer by an electrophotographic copying machine.

The raw materials for waste paper pulp referred to in the present invention include: top white, ruled white, cream white, card, and the like shown in the waste paper standard quality standard table of the Waste Paper Recycling Promotion Center.
Special white, medium white, imitation, fair white, Kent, white art, special top cut,
Other examples include newspapers and magazines. Further specific examples include information-related papers such as uncoated computer papers, thermal papers, printer papers such as pressure-sensitive papers, and OA waste papers such as PPC papers, art papers, coated papers, lightly coated papers, mat papers and the like. Coated paper or high quality paper, color high quality, notebook, stationery, wrapping paper, fancy paper, medium quality paper, newsprint, paper change,
Used paper such as super coated paper, imitation paper, pure white roll paper, uncoated paper such as milk carton and paperboard, chemical pulp paper,
High yield pulp-containing paper is used, but printing, copying,
There is no particular limitation on printing or non-printing.

In addition, waste paper pulp is generally (1) disintegrated .... The waste paper is treated with a mechanical force and a chemical by a pulp to loosen it into a fibrous form, and the printing ink is peeled from the fiber. (2) Dust removal: Foreign matter (such as plastic) and dust contained in the used paper are removed by a screen, a cleaner, or the like. (3) Deinking: The printing ink removed from the fiber using a surfactant is removed out of the system by a flotation method or a washing method. (4) Bleaching: The degree of whiteness of the fiber is increased by using an oxidizing action or a reducing action. It is made from a combination of the four steps.

Further, the transfer paper for electrophotography of the present invention is obtained by applying a starch, polyvinyl alcohol, latex, maleic anhydride type size, α-olefin type size, styrene-acrylic acid type, etc. Apply various surface sizing agents, dimensional stabilizers such as ethylene-urea resin, inorganic conductive agents such as sodium chloride and potassium chloride, organic conductive agents, surfactants, pigments and dyes. As a method for carrying out the method, it is of course possible to use a device such as a conventional size press, a gate roll size press, a size press of a metering blade system, a bill blade, a short dwell coater and the like.

In the paper stock, other than the above, the above-mentioned retention improvers, various anionic, nonionic, cationic or amphoteric substances which have been conventionally used may be used as long as the desired effects of the present invention are not impaired. An internal additive for papermaking such as a drainage improver, a paper strength improver and an internal sizing agent is appropriately selected and used as needed. For example, various starches, polyacrylamide, polyethyleneimine, polyamine, polyamide
1 of polyamine, urea formalin resin, melamine formalin resin, vegetable gum, polyvinyl alcohol, latex, polyethylene oxide, polyamide resin
Species or two or more kinds are used in appropriate combination.

It is also possible to appropriately add an internal additive for papermaking such as a dye, a pH adjuster, an antifoaming agent, a pitch control agent and a slime control agent according to the purpose.

The papermaking method of the present invention is limited to neutral papermaking at a papermaking pH of 6 to 9, but papermaking machines include fourdrinier paper machines, twin wire paper machines, combination paper machines,
A round mesh paper machine, a Yankee paper machine or the like can be used as appropriate.

[0021]

As described in the present invention, neutral paper containing calcium carbonate as a filler and an anionic neutral rosin sizing agent as an internal sizing agent is formed into a paper having a neutral pH of 6 to 9. Also in the region, elution of rosin is minimized, and sufficient sizing can be obtained even with a conventional yield system. Also, since rosin sizing agents do not lower the surface energy of paper,
In addition to excellent toner fixability, double feeding, which is a problem of running property on a copying machine due to a decrease in friction coefficient, is improved.

[0022]

The present invention will be described in detail below with reference to examples. Note that the present invention is not limited to this. All parts and percentages in the following are by weight.

Embodiment 1 1. LBKP (freeness: 350 ml, csf) 70 parts NBKP (freeness: 400 ml, csf) 30 parts Calcium carbonate (Okutama Kogyo; TP-121) 10 parts Anionic Neutral rosin sizing agent (Arakawa Chemical Co., Ltd .; KS-767) 1 part Sulfuric acid band 1 part Amphoteric starch (Oji National Co., Ltd .; Cato3210) 1 part Yield improver (Himo Co., Ltd .; NR-11LS) 0.02 part A 0.3% slurry with a blending width of 1,300 mm and a papermaking speed of 150 m / min. With a Fourdrinier paper machine at 64g /
It was carried out papermaking of m ² of the base paper. The base paper was subjected to a size press with the following composition to obtain a solid content of 1.2 g / m ^2.
Was obtained. 2. Compounding of a size press solution; oxidized starch (manufactured by Nippon Shokuhin Kabushiki Kaisha; MS-3800) 5 parts Sodium chloride 0.15 part Styrene-acrylic acid-based surface sizing agent (Arakawa Chemical Co .; polymalon 1308S) 0.15 parts Water 94. 70 copies

The paper characteristics of the above electrophotographic transfer paper are as follows.
The samples cut in the 4th dimension were evaluated by the following method. 1. Stigecht sizing degree;
The measurement was performed according to P-8112. Electrophotographic transfer paper requires a size of 18 seconds or more in the case of a basis weight of 64 g / m ² , similarly to high quality paper. 2. Static friction coefficient: The static friction coefficient was measured according to JIS P-8147. In this evaluation, front and back, side and side were used as combinations of paper. For electrophotographic transfer paper, a desirable value of the static friction coefficient is 0.45 to 0.75.

The electrophotographic transfer paper described above is suitable for electrophotography using an electrophotographic copying machine (SF-940) manufactured by Sharp Corporation.
0) was evaluated by the following method using a sample cut in an A4 size square. 1. Toner fixing property: A commercially available 18 mm-wide cellophane adhesive tape (Nichiban; cellophane tape) was adhered to an image portion having an optical density of about 1.4 copied by the above copying machine at a linear pressure of 300 g / cm and 1 cm / cm sec. The evaluation was performed using the ratio of the image density after peeling to the image density before peeling (hereinafter abbreviated as OD ratio) when peeling at a speed of as an index. OD ratio = image density after peeling / image density before peeling The electrophotographic transfer paper is required to have a toner fixing property with an OD ratio of 0.7 or more. The image density was measured using a Macbeth reflection densitometer (manufactured by Macbeth; RD-
918) was used. 2. Double feed: Evaluation was made based on the number of double feeds when 2,500 sheets of A4 size paper were passed on one side in a direction perpendicular to the papermaking (CD direction). Seven or less electrophotographic transfer papers are required. 3. Curl: A4 size paper is passed in the CD direction to make a single-sided copy, then placed on a flat table with the curled side up, and the highest value among the four corners is measured. Evaluation was made based on the average value of the sheets. The transfer paper for electrophotography is desirably 3 mm or less.

Example 2 A sample was prepared in the same manner as in Example 1, except that 0.1 parts of colloidal silica (manufactured by Eka; BMA) was used as a retention aid in Example 1.

Example 3 In Example 1, cationic polyacrylamide (manufactured by Allite Coroit; Percoll 47) as a retention aid was 0.03.
Part, bentonite (manufactured by Alite Koroit Co., Ltd .; Hytorocoll O)
A sample was prepared in the same manner as in Example 3, except that one part was used.

Example 4 A sample was prepared in the same manner as in Example 1 except that the amount of the anionic neutral rosin sizing agent was changed to 2.0 parts.

Example 5 In Example 1, 40 parts of base paper LBKP and 20 parts of NBKP were used.
, A sample was prepared in the same manner as in Example 5 except that the amount of the imitation waste paper pulp was 40 parts and the amount of the anionic neutral rosin sizing agent was 1.2 parts.

Example 6 In Example 1, 40 parts of base paper LBKP and 20 parts of NBKP were used.
Copies, 20 copies of used newspaper pulp and 20 copies of imitation used pulp
A sample was prepared in the same manner as in Example 6, except that the amount of the anionic neutral rosin sizing agent was changed to 1.5 parts.

Example 7 In Example 1, 30 parts of base paper LBKP and 10 parts of NBKP were used.
, A sample was prepared in the same manner as in Example 7, except that the amount of used pulp was 60 parts and the amount of anionic neutral rosin sizing agent was 1.5 parts.

Comparative Example 1 A sample was prepared in the same manner as in Example 1 except that the internal sizing agent was changed from an anionic neutral rosin sizing agent to AKD 0.15 parts.

Comparative Example 2 A sample was prepared in the same manner as in Example 1 except that the internal sizing agent was changed from an anionic neutral rosin sizing agent to 0.08 parts of AKD.

Comparative Example 3 A sample was prepared in the same manner as in Example 1 except that the internal sizing agent was changed from an anionic neutral rosin sizing agent to 0.12 parts of ASA.

Comparative Example 4 A sample was prepared in the same manner as in Example 4 except that the anionic neutral rosin emulsion sizing agent was changed to a cationic neutral rosin emulsion sizing agent (C-10, manufactured by Dick Hercules). Example 4 was used.

Comparative Example 5 A sample was prepared in the same manner as in Example 1 except that the filler was changed from calcium carbonate to Indonesian clay (manufactured by PTALTER ABADI; BRU-30).

Comparative Example 6 A sample was prepared in the same manner as in Example 1 except that the filler was changed from calcium carbonate to talc (manufactured by Hyogo Clay Co., Hyogo Talc).

The above results are summarized in Table 1.

[0039]

[Table 1]

[0040]

As is evident from Table 1, the present invention provides a neutral paper containing calcium carbonate as a filler and an anionic neutral rosin sizing agent as an internal sizing agent. It is possible to manufacture an electrophotographic transfer paper which is excellent in base paper sizing properties and toner fixing properties and has improved double feeding on a copying machine.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 7/00 101 D21H 17/62

Claims (2)

(57) [Claims] 1. A filler containing calcium carbonate as a filler,
And a neutral paper containing an anionic neutral rosin sizing agent as an internal sizing agent. 2. The transfer paper for electrophotography according to claim 1, wherein the neutral paper contains waste paper pulp.