JPS62284763A - Platen roller - Google Patents

Abstract

PURPOSE:To obtain a platen roller free of possibility of defective printing even when the temperature thereof is raised, by fitting a rubber member containing 2-11wt% of a cross-linking agent to the periphery of a core member. CONSTITUTION:A rubber member 2 containing a cross-linking agent in a concentration of 2-11wt% so as to have a glass transition point in an ordinary service temperature range is used. With the cross-linking agent blended in an amount of 2-11wt%, the hardness and the impact strength of the rubber member are enhanced, so that an effect of preventing defective printing is obtained. The rubber member for a platen roller can be obtained by blending a raw material polymer, carbon, an inorganic filler, an oil, sulfur, a vulcanizing assistant, a vulcanization accelerator, stearic acid and, if required, a poroxide as a cross- linking agent, a plasticizer, a reinforcing agent or the like in appropriate amounts, as in the case of formulation and design for a rubber material for a generally used platen roller.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a platen roller, and more particularly to a platen roller used in a printing device such as a typewriter.

(Prior Art and Problems) Conventionally, printing devices such as typewriters have had a platen roller that acts as a base plate during printing. This platen roller usually has a core part 1 as shown in Figure 1.
It has a cylindrical shape made of a rubber or resin material 2 wrapped around it, and as shown in Fig. 2, a printing hammer 6 is placed around the printing paper 3 and overlapping the ink ribbon 4. The pressed daisy foil 5 is pressed, and the characters of the daisy foil 5 are printed on the printing paper 3.

The printing performance of the printing paper obtained as above is as follows:
Impact 4 when Daisy foil 5 is pressed: +l
The present inventor has confirmed through experiments that it depends on lIj. The impact load is determined by the hardness of the rubber material and the strength and speed of the hammer impact. If this impact load is insufficient, printing defects such as missing parts of characters or unclear outlines of characters will occur.

The occurrence of such printing defects is a serious problem in conventional typewriters, and generally occurs frequently when the environmental temperature is high. This defective print is caused not only by manual typewriters in which the pre-impact fQ is uneven, but also by electric typewriters in which one machine applies a certain impact force to the daisy foil.
It has also been observed that the temperature of the platen roller increases even more when printing continues for a long time.

By the way, the present inventor has learned that printing performance is affected not only by impact loads but also by impact resistance, and that printing can be improved by increasing impact attenuation, represented by rebound resilience (reducing rebound resilience). I found that the performance improved. It has also been found that in the case of rubber materials, the anti-S damping capacity increases at temperatures near the glass transition point.

(Object of the invention) The present invention has been made in view of the above circumstances,
The purpose is to provide a platen roller that does not cause printing defects, and in particular does not cause printing defects even when the temperature rises due to long-term use even if the environmental temperature is high.

[Means for solving problems]

The above object of the present invention is to apply 2 to 1 crosslinking agent around the core metal material.
This is achieved by a platen roller equipped with a rubber material containing 1% by weight.

That is, in order to prevent the occurrence of printing defects by increasing the impact attenuation ability in the normally used temperature range, the present invention has a crosslinking agent concentration of 2 so that the glass transition point is set within the normally used temperature range. ~l l l'l'[jI
i% rubber material is used.

The blending concentration of the crosslinking agent is 2 to l l, 1lIQ%,
Preferably it is 3 to 10.5% by weight, more preferably 1 to 10% by weight.

Blending a large amount of crosslinking agent in the range of 2 to 11% by weight increases the hardness of the rubber material and increases the impact load, which is more effective in preventing printing defects.

In the present invention, the weight percent of the crosslinking agent is the sum of sulfur and peroxide as a crosslinking agent i((ji1%).

The rubber material of the platen roller of the present invention is made of a raw material polymer (
synthetic, natural rubber and/or thermoplastic elastomer), carbon, inorganic fillers, oil, sulfur, vulcanization aids, vulcanization accelerators, stearic acid, and other crosslinking agents and peroxides as necessary. 1 if! It is obtained by blending appropriate amounts of fl agents, reinforcing agents, etc.

Raw material polymers include SBR, NBR, IR, NR,
Rubber or RB of CR, I IR, aR'J.

Thermoplastic elastomers such as SBS, polyolefin, polyester, polyurethane, PVC, or blends thereof are used.

Carbons include l5AF, SAF, and HAF.

FEF, SRF, FT, EPC, MPC or a blend thereof is used.

As the inorganic filler, it is also effective to use calcium carbonate, various clays, talc, etc., or blends thereof, and silica-based fillers such as hydrous silicic acid, anhydrous silicic acid, and their respective salts.

As softeners, those based on vegetable oils such as aromatic, naphthenic and paraffinic ones, and those based on mineral oils such as paraffin wax and mineral rubber are also used. Factices are also used.

Zinc is a good vulcanization accelerator! (2) Metal oxides such as magnesia and fatty acids such as stearic acid are used.

As the vulcanization accelerator, aldehyde amines, guanidines, thiazoles, thiurams, dithiocarbamates, xanthates, etc., and various combinations thereof are used.

As a crosslinking agent, dicumyl peroxide, ditertiary
Peroxides such as butyl peroxide and benzoyl peroxide, their agglomerated sulfur, organic sulfur-containing compounds, metal oxides, quinone dioximes, organic polyvalent amines, modified phenolic resins, and the like are used.

Examples of plasticizers include phthalates such as oup and oop, adipates such as DO8, sebacates such as DO5, and T.
(Phosphate type such as l+, polyether type,
Polyester type etc. are used.

Further, as the organic reinforcing agent, high styrene resin, phenol resin, modified melamine resin, etc. can be effectively used.

Further, as an adhesive material, a coumaron-indene resin, a phenol-terpene resin, a rosin derivative, etc. are used in an appropriate amount '1.

In addition, various combinations of aldehydes, ketones, amines and their 3A conductors, wax-based products, and stiff materials are used as anti-aging agents.

In addition, xylyl mercaptan, 2-
Benzamide thiophenol, zinc salt, etc. are used.

〔Example〕

Example 1 Rubber as shown in Table 1 was placed in a mold at 150°C.
By vulcanizing for 90 minutes at
A cylindrical rubber material of JIS-A scale (measured at 20° C.) was obtained, and the platen roller of the present invention was obtained by attaching the rubber material to an aluminum core material. This platen roller can be used as an electronic typewriter (Canon: AP).
360) and continuously printed 1000 characters on bank bond paper at 0°C, 20°C, and 50°C, and no printing defects occurred.

Further, the glass transition point temperature of the rubber material of this platen roller was measured by measuring the temperature dispersion of tan δ under conditions of constant strain and constant frequency using a dynamic viscoelasticity measuring device, and found it to be 20°C.

In addition, the rubber shown in Table 1 was put into a mold (J1 to 6:1 OI: for making an impact resilience test test piece) and press-vulcanized at 150°C for 90 minutes, and the resulting test piece was Repulsion resilience was determined at each temperature. The results are shown in Table 2.

Comparative Examples 1 to 3 Platen rollers were made in the same manner as in Example 1 except that rubbers whose formulations are shown in Tables 3 to 5 were used, and the same printing test was conducted. 2, 100, and 150 defective prints occurred for each sample.

Further, the glass transition temperature of the rubber material of this platen roller was determined in the same manner as in Example 1, and was found to be 5°C, -20°C, and 48°C, respectively.

[Tani example]

A large number of platen rollers made of rubber materials with various formulations containing 0.1 to 14% crosslinking agent by market weight were installed in the same printer as in Example 1, and the rubber material portion was heated to -30°C.
1000 characters were continuously printed while maintaining the temperature at 5° C. intervals from 100° C. to 100° C., and the number of defective prints that occurred was measured.

Judgment of measurement results is based on defective printing beyond 10 characters (missing characters, missing parts of ink, unclear printing/outlines, uneven print density). , and those below that were considered to have good printing quality. When we plotted the compounding concentration of the crosslinking agent for each rubber material and the temperature of the platen roller, we could clearly distinguish between the areas of poor printing and the points of good printing.When we drew the boundary line, we can see in Figure 3. A graph like the one shown was obtained.

As can be seen from the graph, the platen roller using a rubber material containing 2 to 11% by weight of a crosslinking agent can be
It can be said that printing defects do not occur even when used at a temperature of 0°C.

Table 1 Table 2 Table i3 Table 4 Table 5 1) Japan Synthetic Rubber 2) Asahi Capo / 3) Shiraishi Kogyo Nizil Bar W 4) Nippon Sun Oil 5), 8) Anauchi Shinko Kagaku 7) Asahi Carbon 8) Asai α Industry 8) Ouchi Kenko Chemical [Effects of the Invention] As described above, the platen roller of the present invention can obtain high-quality printing for a long time even in high environmental temperatures, and has a low concentration of cross-linking agent. Since it can be obtained by a simple operation of adjustment, economical improvement can be achieved.

4. Brief description of surfaces Figure 1 is a schematic diagram of the platen roller of the present invention, Figure 2 is a schematic diagram of the printing part of the printer, and Figure 3 is a diagram of the rubber material of the platen roller. It is a graph showing the correlation between the compounding concentration of the crosslinking agent and the temperature at which it is used, which contributes to the quality and quality of printing.

1. Core metal part 2. Rubber material (resin material) that is a hard elastic layer 3: Printing paper 4. Ink ribbon 5: Daisy foil 6. Printing hammer Prefecture map 2

Claims (1)

[Claims] A platen roller in which a rubber material containing 2 to 11% by weight of a crosslinking agent is attached around a core material.