JPS63107572A - Platen roll - Google Patents

Abstract

PURPOSE:To keep print ability and to achieve the light weight and the low noise in a high frequency range of a title roll, by constituting the title platen roll by two layers of an inner layer composed of resin with a shaft as the core and an outer layer composed of rubber composition. CONSTITUTION:A roll is constructed by using a shaft 1 as a core, a rubber composition consisting of high hard rubber or elastomer as an outer layer 3, and resin as an inner layer 2. As the inner layer 2, thermoplastic resin or thermosetting resin and, if necessary, composite material of those containing filler are used for the purposes of having sufficient rigidity and achieving its lightening. Its bending elastic modulus should necessarily be 20,000-150,000kg/cm<2>. Since the outer layer 3 is deeply concerned in noise and besides, largely influences printability, the rubber composition of the outer layer 3 should necessarily be 200-500kg/cm<2> in tensile elastic modules at 5% elongation and 0.15-0.50 in tandelta at 100Hz and 0.3% strain.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a low-noise platen roll that reduces noise during printing in an impact type printer and is lightweight.

The conventional platen roll used in printers using the return ball impact printing method has a highly hard rubber layer 4 concentrically arranged around a metal shaft 1, as shown in Figure 4(a). Or, as shown in Fig. 4(b), a high hardness rubber layer 4 is provided on the outside of an integral roll of a metal shaft 1 and a metal cylinder 5, and these are commonly used. . The problems with these conventional platen rolls are (1) high noise during printing, which is unfavorable for the health of workers and the surrounding indoor office environment; (2) large weight, and large drive motors. Since this is necessary, there is a problem that it is not possible to make the device more compact or to save power.

For this reason, platen rolls with a two-layer structure or a three-layer structure, which are made of a rubber-like elastic body concentrically fixed to a core of a metal shaft or a metal shaft coated with a resin, have been previously proposed. (Patent application 1986-273390, 1986-273391, 1984-273392)
, these inventions had considerable effects in the 2 kHz to 4 kHz range, and were able to achieve noise reduction; however, in order to reduce noise in the relatively high frequency range of 8 kHz, I didn't have high expectations.

- While the mouth is about to unravel Points: As mentioned above, conventional platen rolls are not fully satisfactory in reducing noise in the high frequency range, so the present invention maintains printing suitability, is lightweight, and By achieving low noise in the high frequency range, the aim is to solve problems such as improving and improving the working environment all at once.

The inventors of the present invention have conducted extensive research into a lightweight platen roll that sufficiently exhibits noise reduction performance in the high frequency range for impact-type printers, and have developed the following in Figure 1. As shown in (11), by using a rubber composition made of high hardness rubber or elastomer for the outer layer 3 and using resin for the inner layer 2, sufficient printing suitability is maintained and it is possible to maintain sufficient printability in the high frequency range. We were able to achieve lower noise and lighter weight.

(2) The contribution of the outer layer 3 to noise reduction is greater than that of the inner layer 2, and its material properties include tan, which represents the viscosity term.
We discovered that δ and Es (5% tensile modulus of elasticity) representing a spring ring are dominant, and that there is an optimal range of physical properties, and we would like to make a proposal first (Japanese Patent Application Laid-Open No. 132669/1982). That is,
The optimal physical property range is tan δ of 0.15 to 0.3.
0 and the tensile modulus at 5% elongation is 200 to 45
It was 0 kg/aa.

As a result of further intensive research, the inventors found that ta
It has been found that noise reduction can be achieved even when nδ is 0.15 to 0.50 and the tensile modulus at 52 stone elongation is in the range of 200 to 500 kir/cJ. In other words, the noise generated by the platen roll consists of the noise directly generated by the printing impact and the noise generated by the platen roll vibrating due to the impact.
It has been found that a high tan δ and a low elastic modulus is effective, and a high tan δ and a low elastic modulus is desirable for the latter noise generated by vibration. Furthermore, by setting a high tan δ, vibrations generated by printing impact are transmitted to the casing of the printer, which is effective in reducing the solid sound of the casing generated therefrom, and it is possible to achieve overall noise reduction.

The results of this study show that when tan δ is less than 0.15, the noise generated by the printing impact and the vibration of the roll increases, making it impossible to reduce the noise, while when tan δ is more than 0.5, the temperature dependence of the elastic modulus is large and The behavior of the rubber elastic body upon impact becomes hard, and as a result, noise cannot be reduced.

Regarding the effect of Es, the propagation speed of vibration is in the case of longitudinal waves, and in the case of transverse waves, μ is Poisson's ratio, E is the elastic modulus (Es corresponds here), and ρ is the density. When the Poisson's ratio is small and the amount of deformation is minute, μ can be ignored, and the velocity is vertical.As is obvious, the smaller the elastic modulus Es, the slower the propagation speed, and during this time, the noise is reduced due to the diffusion of vibration energy, etc. can be achieved. Specifically, the purpose is achieved by setting Es to a low elastic modulus of 500 kg/aa or less. However, E5 is 200kg/
If the temperature is below -, the print quality deteriorates particularly in a high temperature range, which is not desirable. In other words, the tensile modulus at 5% elongation is 20
0 to 500 ksr/aa is the optimum physical property range from the viewpoint of reducing noise and maintaining print quality. The above two physical property regions must be satisfied at the same time, and unless either one is satisfied, effective noise reduction cannot be achieved.

(3) The outer layer is deeply involved in the above-mentioned noise, and also greatly affects printing suitability. In particular, it correlates with hardness, elastic modulus, and viscous ring tanδ, with hardness of 95 (J
I 5-A) or less, and with a high viscosity system such as tan δ of 0.5 or more, the printing paper will become perforated or torn when struck by the impact head, and will not function as a platen roll. , hardness is 100 or more and tan δ is 0.1
If it is less than 5, the repulsion will be large and the contact time between the printing paper and the head will be extremely short.
Characters with sharp corners, such as fonts, etc., will be blurred or some parts of the characters will not be printed and will be unclear, resulting in poor printing suitability.

In this way, from the point of view of printing suitability, the hardness is 95 to 10.
0, and tan δ needs to be in the range of 0.15 to 0.50. As mentioned in section (2), the modulus of elasticity must be 200 kg/a to maintain printing suitability especially in high temperature ranges! The above is desirable.

(4) For the inner layer 2, a thermoplastic resin or a thermosetting resin and a composite material containing a filler as necessary are used to reduce the weight. Since it is also rotating while being struck by the force, it bends and bends against such external force.
If deformation occurs, it becomes a source of noise and also loses printing suitability, so it must have sufficient rigidity. In order to meet this requirement, the resin used for JEi2 must have a flexural modulus of 20,000 to 150,000.
kg/ad.

To explain the present invention in more detail based on the above study results, materials constituting the outer layer 3 made of a rubber composition include (1) natural rubber, polystyrene-butadiene copolymer rubber, polychloroprene rubber, ethylene-propylene It is characterized by being one or more selected from the group consisting of copolymer rubber, polybutadiene rubber (including 1,2-polybutadiene resin), polyurethane rubber, polyacrylate rubber, polynorbornene rubber, and polybutyl rubber. and (2) one or more selected from the group consisting of natural rubber, polyisoprene rubber, styrene-butadiene copolymer rubber, polychloroprene rubber, ethylene-propylene copolymer rubber, and polybutadiene rubber, and +C-NH in the molecule in sulfurable rubber
A reinforced rubber composition in which short fibers of a thermoplastic polymer having a + group are grafted via an initial polymerization product of a phenol-formaldehyde resin, wherein the proportion of the short fibers of a thermoplastic polymer in the rubber composition is the total rubber component. It is characterized by being 2 to 30 parts by weight per 100 parts by weight, and t
anδ is 0.15-0.50, Es is 200-5 Q
It is sufficient as long as it satisfies Qk, /ad.

In addition, the material constituting the inner N2 (Fig. 1) is A.
There are thermoplastic resins such as BS resin, polystyrene resin, polyethylene resin, polypropylene resin, polyamide resin, AS resin, and noryl resin, and thermosetting resins such as phenol resin, epoxy resin, unsaturated polyester resin, and diallyl phthalate resin. , the bending modulus is 20.
000 to 150.000 kg/d, and these resins may be used alone or in a blend system.

The outer N3 explained above has a thickness of 2 to 5 u+, and the inner J
By making i12 10 to 25 m thick and integrally forming it concentrically on a metal shaft, it has become possible to reduce the weight and noise of the platen roll while maintaining printing suitability.

Next, the present invention will be explained in detail based on Examples, but the present invention is not limited to these Examples in any way.

Example (1) As materials constituting the outer layer 3, 100 parts by weight of ethylene-propylene copolymer, 30 parts by weight of 1,2-polybutadiene resin
A rubber composition consisting of ilJt part and carbon black 100 parts by weight, and its physical properties are 5% elongation tensile modulus 320 kg/c+d, tan δ 0.181, hardness 9.
It is 8. On the other hand, the material constituting the inner layer 2 is AB
Using S resin (Nippon Steel Chemical AB S-300),
A platen roll was obtained which was integrally molded concentrically with the metal core 1 having a diameter of 10 mm using the above-mentioned material and having an inner layer thickness of 1011 nm and an outer layer thickness of 3 nm.

Example (2) The material constituting the outer layer 3 is a rubber composition consisting of 80 parts by weight of styrene-butadiene copolymer, 20 parts by weight of FRR (composition shown below), and 50 parts by weight of carbon black. Physical properties: 5% elongation tensile modulus 470kg
/cffl, tan δ 0.46B, and hardness 97.

The composition of the above FRR is 50 parts by weight of 6-nylon (1030 B manufactured by Ube Industries Ltd.) per 100 parts by weight of natural rubber.
This is a reinforced rubber obtained by kneading 2.14 parts by weight of a novolak-type phenol formaldehyde precondensation product (Showa Kasei (manufactured by 550PL)) and subjecting it to a graft reaction.

The details of the manufacturing method are specified in the previously proposed patent application No. 61-76313. On the other hand, the ABS resin used in Example 1 was used as the material constituting the inner N2, and a platen roll integrally molded concentrically with the core 1 was obtained, with the inner layer having a thickness of 10 μl and the outer layer having a thickness of 31 m.

Comparative Example 1 A rubber composition consisting of 100 parts by weight of styrene-butadiene copolymer and 80 parts by weight of carbon black as the material constituting outer M3, and its physical properties were as follows: 5% elongation tensile modulus: 523 kg/cflI, tan δ0 .466
, the hardness is 97, the materials constituting the core 1 and the inner layer N2 are the same as those in the example, and the inner layer has a thickness of 101 cm.
A platen roll was obtained in which the outer layer had a thickness of 3D and was integrally molded concentrically with the core l.

Comparative Example 2 A shaft with a protruding metal shaft 1 with a diameter of 101 times at both ends as shown in Fig. 2 (bl) has an inner diameter of 24mm and an outer diameter of 30*.
*Thermosetting polyurethane rubber with a thickness of 3 mm is used on the outside of the hollow cylindrical roll, and its physical properties are as follows: 5% elongation tensile modulus is 842 kg / crA, tan δ 0.11
4. The hardness is 98.

Example 1 above. Example 2. Comparative example 1. Details of Comparative Example 2 are shown in Table 1.

Using the platen rolls of Example 1.2 and Comparative Example 1.2 described above, it was installed on an actual printer and
Place it on the table of 100CJ1 in the horizontal direction in front of it.
A microphone was placed at position 1, and measurements were performed with printing paper interposed.

The measurement results of the noise level explained above are shown in Figures 2 and 3.
As shown in the figure. As is clear from FIGS. 2 and 3, the platen roll of the example has a frequency of 3 to 7.0 kHz, especially in the range of 4 to 8 kHz, compared to the platen roll of Comparative Examples 1 and 2. s d
nxi sound level is reduced, and the noise reduction effect is noticeable. In addition, at the same time as the actual noise level measurement, the printing suitability was visually determined by repeatedly hitting angular characters M and W, and in this case, there was no difference between the example and comparative example 1.2, and the results were good.

Regarding the weight, there was almost no difference between Examples and Comparative Example I, but compared to Comparative Example 2, Examples 1 and 2 had a weight of 7 to 8
% weight is lighter.

As detailed above, the platen roll of the present invention is significantly effective in reducing noise, is lightweight, and can contribute to improving the working environment without impairing printing suitability. It also has the effect of saving energy.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a longitudinal sectional view of a platen roll according to the present invention;
FIGS. 2 and 3 are diagrams showing noise levels comparing the platen roll according to the present invention and a platen roll other than the present invention, and FIGS. 4(a) and 4(b) are diagrams showing the noise levels of the conventional platen roll. FIG. In the figure, 1...shaft, 2...inner layer, 3...outer layer, 4...rubber layer, 5...metal cylinder. Agent Patent Attorney 1) Osamu Kuro Figure 1 Figure 4 (a) Figure 2 (dBA)

Claims (5)

[Claims] (1) An inner layer made of a resin that has the shaft as a core and is tightly attached concentrically around the core, and an outer layer that is made of a rubber composition that is further tightly attached around the inner layer concentrically with the core. A platen roll consisting of two layers. (2) The platen roll according to claim (1), wherein the resin of the inner layer is a thermoplastic resin or a thermosetting resin. (3) The inner layer resin has a flexural modulus of 20,000 to 150,
The platen roll according to claim 1, which has a physical property of 000 kg/cm^2. (4) The rubber composition of the outer layer is (a) ethylene-propylene copolymer rubber, polybutadiene rubber (including 1,2-polybutadiene resin), polyurethane rubber, natural rubber, polyisoprene rubber, styrene rubber,
One or more selected from the group consisting of butadiene copolymer rubber, polychloroprene rubber, polyacrylate rubber, polynorbornene rubber, or (b) natural rubber, polyisoprene rubber, styrene-butadiene copolymer rubber, polychloroprene. Thermoplastic having one or more selected from the group consisting of rubber, ethylene-propylene copolymer rubber, and polybutadiene rubber, and vulcanizable rubber with ▲ mathematical formula, chemical formula, table, etc. in the molecule. A reinforced rubber composition in which short fibers of a polymer are grafted via an initial polymerization product of a phenol-formaldehyde resin, wherein the proportion of short fibers of a thermoplastic polymer in the rubber composition is based on 100 parts by weight of the total rubber component. The platen roll according to claim 1, wherein the amount is 2 to 30 parts by weight. (5) The rubber composition of the outer layer has a tensile modulus of elasticity at 5% elongation of 200 to 500 kg/cm^2, 100 Hz, 0
．． The platen roll according to claim 1, wherein tan δ at 3% strain is 0.15 to 0.50.