JPH04204745A - Electrophotographic transfer paper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Field of application for the invention]

The present invention relates to an electrophotographic transfer paper having excellent size properties and constant toner adhesion.

[Conventional technology]

In recent years, electrophotographic transfer paper has been increasingly produced with neutrality, with the aim of improving whiteness and opacity and improving the paper's shelf life through the use of calcium carbonate. When producing paper in neutral conditions, rosin sizing agents that perform well in an acidic atmosphere and in the presence of sulfuric acid cannot be used, and neutral sizing agents are used instead. As a neutral sizing agent, an aqueous dispersion of an alkyl ketene dimer is most commonly used because of its ease of handling or the ability to obtain excellent sizing properties with the addition of a small amount. In addition, cationic polymer-type neutral sizing agents include alkyl ketene dimer (hereinafter abbreviated as AKD) and alkenyl succinic anhydride (
If the amount added is the same as that of ASA (hereinafter abbreviated as ASA), paper of sufficient size cannot be obtained. AKD or AS as a sizing agent for electrophotographic transfer paper
When A is used, increasing the amount of sizing agent added to increase the degree of sizing tends to lower the surface energy of the paper and deteriorate the fixing properties of the toner transferred in an electrophotographic copying machine. As countermeasures against this, attempts have been made to reduce the amount of AKD or ASA added, use other neutral sizing agents, and increase the amount of surface size starch applied.

[Problem to be solved by the invention]

Techniques that can be applied to obtain electrophotographic transfer paper with excellent size and constant toner adhesion include the AK method described above.
These include reducing the amount of D and ASA added, applying other neutral sizing agents, and increasing the amount of surface size starch applied. However, by reducing the amount of AKD added or using other sizing agents, although the toner adhesion is good, paper with sufficient sizing cannot be obtained, and when the amount of surface size starch adhesion increases, the curling properties of the paper deteriorate. In either case, electrophotographic transfer paper of sufficient quality could not be obtained. That is, an object of the present invention is to provide an electrophotographic transfer paper having excellent size properties and toner constant adhesion.

[Means for Solving the Problems] In order to solve the above problems, the present inventors investigated the use of a surface sizing agent whose main component is an olefin/maleic acid copolymer. Copolymer surface sizing agents are excellent, and among them, surface sizing agents made from α-olefin monomers with a carbon number of 10 or less are particularly good, and they are coated with oxidized starch in a size press or gate roll coater. It has been found that by coating the paper surface with -(GRC), the adverse effect of the internal sizing agent on toner adhesion can be significantly reduced. On the other hand, if the α-olefin has 14 or more carbon atoms, the surface free energy decreases, so although improvements in size properties can be expected, improvements in toner adhesion properties are not expected to improve much. On the other hand, when a surface sizing agent in which the α-olefin carbon number is 12 or less and the α-olefin monomer is 50% or less by weight is applied to the paper surface from 0.01 g/d to 0.1 g/d, the toner adheres to a certain level. They discovered that the sex improvement effect was even more remarkable and completed the present invention. The reason for this is that in addition to covering the surface covered with the sizing agent with starch, applying a surface sizing agent with small hydrophobic groups and a small proportion of the hydrophobic group in the molecule increases the surface free energy. It is thought that the adhesion between the paper surface and the polyester resin or styrene acrylic resin used as a toner binder is improved. In the present invention, the electrophotographic transfer paper is used as a recording material in copying machines and page printers using the transfer electrophotographic method (xerography), continuous printers that apply this method, facsimile machines, full-color copying machines, etc. It is something. The pulp used for the base paper of the present invention is NBKPX
LBKPXNBSP, LBSP, GP. Examples include TMP. When using them, they are mixed in a ratio depending on the purpose. In addition, the surface sizing agent whose main component is an olefin/maleic acid copolymer used in the present invention is, for example,
It refers to a surface sizing agent whose main components are an olefin and maleic acid, as described in JP-A-210095, JP-A-2-200896, and the like. If the amount of surface sizing agent applied is less than 0.01 g/d, sufficient improvement in toner adhesion cannot be obtained. Further, even if the coating amount is 0.1 g/rd or more, the toner adhesion is not improved any further. The electrophotographic transfer paper of the present invention includes:
It contains dyes, fillers, sizing agents, fixing agents, dry paper strength enhancers, etc. as necessary. The surface sizing agent of the present invention can be applied to the surface of base paper by size press and GRC, and may be used alone or mixed with starch.

【Example】

In the following, the present invention will be explained in detail by way of examples. Note that the present invention is not limited to the examples. All parts and percentages below are by weight. In addition, unless otherwise specified, the values indicating the amount of smearing are the weights after drying. Preparation Example 1 A method for preparing a surface sizing agent obtained by copolymerizing an α-olefin monomer and maleic acid used in Examples is shown below. 98 parts of maleic anhydride and 4 parts of toluene were placed in a flask equipped with a stirrer, cooling tube, dropping funnel, nitrogen introduction tube, and thermometer.
4.6 parts were charged and the temperature was raised to 110° C. under stirring and nitrogen flow. A dropping funnel was charged with 73.7 parts of diisobutylene and 56 parts of 1-octene, and a separate funnel was charged with 10.5 parts of t-butyl peroxybenzoate and 40 parts of 1.luene. These were added dropwise into the flask from the dropping funnel over a period of 1.5 hours, and kept warm under reflux for about 2 hours. Then, t-butylperoxy-2-ethyl hexae! -4.2 parts and 20 parts of toluene were added dropwise over about 30 minutes, and the mixture was further kept at the same temperature for 1 hour. Toluene was distilled off under reduced pressure, and the polymer was mixed with 8 parts of sodium hydroxide, a predetermined amount of water, and 10 L of 28% aqueous ammonia.
An aqueous copolymer solution was obtained by neutralizing the mixture in 1 part. Preparation Examples 2 to 8 Aqueous copolymer solutions were obtained by carrying out the reaction in the same manner as in Preparation Example] except that at least one of the amount of the monomer used and the composition was changed. Example I Pulp 10 prepared by mixing LBKP beaten in a PFI mill to a freeness of 380 m1c, s, f, and NBKP beaten to a freeness of 450 m1e, s, f at a weight ratio of 7.3.
0 parts, 7 parts of light calcium carbonate (TP121, manufactured by Okutama Kogyo Co., Ltd.), 0.1 part of alkyl ketene dimer (Sizepine K 903, manufactured by Arayo Kagaku Co., Ltd.), Amphoteric starch (kei h3
210 (manufactured by Tamago National Co., Ltd.) in an amount of 78 parts to prepare a handmade sheet with a basis weight of 64 g/rd. Note that the sheet was dried at 90° C. for 5 minutes. These sheets are then processed into size presses together with oxidized starch to form α-olefins with carbon numbers of 8, 10, 12, 14, 18 and 5.
Surface sizing agents of different levels were applied, and machine calendering was performed so that the Bekk smoothness was 80 seconds to obtain an electrophotographic transfer paper. Sample 1-1, sample 1-2, sample 1-3 in descending order of the number of carbon atoms in the Nobi-1 olefin in the surface sizing agent used.
, Sample 1-4 and Sample 1-5 5. Example 2 The molar ratio of the α-olefin monomer having 8 carbon atoms was applied to the handmade sheet of Example 1 at three levels of 1.0.20% and 50%. Samples were obtained in the same manner as in Example 1 except that different surface sizing agents were applied. These samples are designated as sample 1-6, sample 1-7, and sample 1-8, respectively, in descending order of molar ratio. Comparative Example 1 Samples were obtained in the same manner as in Example 1 except that no oxidized starch was applied using the size press and no surface sizing agent was added when applying the oxidized starch using the size press. . These samples were divided into sample 2-1 and sample 2-
Set it to 2. The results are summarized in Table 1. (Left below) Here, Tona constant adhesion is a PPC copying machine (5055,
A commercially available 18 mm wide adhesive tape (cellophane tape, manufactured by Nichiban Co., Ltd.) was pasted with a linear pressure of 300 g/'cmO to the image area with an optical density of approximately 184, which had been copied using Fuji Xerox Co., Ltd., and was peeled off at a speed of lem/sec. It is the ratio of the image density after peeling to the image density before peeling. For electrophotographic transfer paper (7), a constant toner adhesion of OD ratio of 0.58 or more is required.A Macbeth reflection type densitometer was used to measure the image density. The following OD ratio was used as an index for evaluating the properties: OD ratio - image density after peeling/image density before peeling
The degree of size was measured by the Stegicht method according to J I 5P8122. As with high-quality paper, electrophotographic transfer paper
In the case of a basis weight of 64g7'n, a sizing property of 18 seconds or more is required. From Table 1, a surface sizing agent made from an α-olefin monomer with a carbon number of 12 or less is applied to the paper surface. thing,
It is clear that an electrophotographic transfer paper with excellent toner constant adhesion and sizing properties can be obtained by applying a surface sizing agent having an olefin content ratio of 1096 to 50% to the paper surface. Example 3 A surface sizing agent having an α-olefin carbon number of 8 was used on the same handmade sheet paper as in Example 1, and the amount applied with a size press was 0.01.0.03.0°05. Samples were prepared in the same manner as in Example 1, except that the smear amount was changed to 5 levels of 0, 1, 0,115 g, and 100 g. These samples were classified into Sample 3-1, Sample 3-2, and Sample 3-2 in descending order of smear amount.
Sample 3-3, sample 3-4, and sample 3-5. Example 4 A surface sizing agent having an α-olefin carbon number of 18 was applied to the same hand-made paper as in Example 1, and the amount applied was 0.01.0.03.0°05. Samples were prepared in the same manner as in Example 1, except that the smear amount was changed to 5 levels of 0.10 and 0.15 g/go. 3 These samples were divided into sample 4-1 and sample 4-2 in descending order of smear amount.
, sample 3 Example 3-3, trial amount 4-4, and sample 4-5. The above results are summarized in Table 2. Table 2 [Effects of the Invention] From the above examples, it is clear that the surface of the electrophotographic transfer paper of the present invention, that is, the paper containing an alkyl ketene dimer or alkenyl succinic anhydride, contains an olefin-maleic acid copolymer as the main component. 0.01g/I' of a certain surface sizing agent
It has become clear that electrophotographic transfer paper coated with a coating of 0.110 g/'d or less has excellent size properties and toner fixation properties. Name: Electrophotographic transfer paper 3, relationship with the amended person case Patent applicant address: 4-2 Marunouchi Otsu-chome, Chiyoda-ku, Tokyo Name (598) Mitsubishi Paper Mills Co., Ltd. Patent Department, Mitsubishi Paper Mills Co., Ltd. (3627) 9360 4. Target of amendment (1) "Free energy" on page 4, line 10 of the specification is corrected to "energy". (2) "1 free energy" on page 5, line 1 of the specification is changed to " energy”.

Claims (1)

[Claims] 1. In an electrophotographic transfer paper containing calcium carbonate as a filler and an alkyl ketene dimer or alkenyl succinic anhydride as an internal sizing agent, the main component on the surface is an olefin. Coating amount of surface sizing agent which is maleic acid copolymer is 0.01g/m^2 or more 0.10
An electrophotographic transfer paper characterized by being coated in a range of g/m^2 or less. 2. The raw material olefin monomer of the surface sizing agent has 1 carbon number.
2. The electrophotographic transfer paper according to claim 1, wherein the electrophotographic transfer paper is an α-olefin monomer of 0 or less, and the α-olefin content in the copolymer is 10% or more and 50% or less in mol%.