JPS621823B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a leak-proof sheet, and particularly to a method for manufacturing a leak-proof sheet suitable for use by incontinent patients in hospitals, facilities, and homes. Various types of leak-proof sheets are already known, including polyethylene,
Products made by laminating a synthetic resin film such as polyurethane with cotton cloth etc. are commercially available. but,
This type of leak-proof sheet has the disadvantage that it shrinks and wrinkles when subjected to disinfection treatments such as steam sterilization, and its leak-proof properties gradually deteriorate. They also had the disadvantage of degrading when washed with detergents, and furthermore turning yellow and becoming brittle when dried in the sun. In addition, this kind of leak-proof sheet is slippery, and when placed on the bed, it may shift or fall off the bed. This had the disadvantage that it had to be rolled up and used, which meant that it had to be larger than necessary. For this reason, leak-proof sheets have been developed that have a silicone rubber layer on a fiber base material (see Japanese Patent Application Laid-open No. 166236/1983). However, it is difficult to control this process because the formation of this silicone rubber layer is greatly influenced by the physical properties of the silicone rubber used. This silicone rubber layer has the disadvantage of being prone to pinholes and scratches, and in order to reduce these disadvantages, making this film layer thicker will make the entire sheet heavier and inconvenient to handle. It has the disadvantage of being expensive and causing problems in terms of economic efficiency. The present invention relates to a method for manufacturing leak-proof sheets using silicone rubber that solves these disadvantages.This method involves applying a curable liquid organopolysiloxane composition to a silicone rubber thin film, and then applying a curable liquid organopolysiloxane composition to
This method is characterized in that it is pressed against a fiber base material, and then this liquid organosiloxane is cured. To explain this, the present inventors have conducted various studies on a method for producing a leak-proof sheet having a silicone rubber layer that is free of pinholes and scratches, and as a result, a thin silicone rubber film is prepared in advance using a calendar roll or other means. We focused on the fact that the desired leak-proof sheet could be easily obtained by attaching this to a fiber base material, and as a result of researching this attachment method, we found that it requires a curable silicone rubber thin film. When a liquid organosiloxane composition is applied and the coated surface is pressed against a fiber base material, this liquid organosiloxane composition permeates into the fiber base material, and when it is then cured, this silicone rubber thin film and fibers are bonded together. The present invention was completed by confirming that the material could be completely bonded to the base material. The silicone rubber thin film used in the present invention is prepared by forming a thermosetting silicone rubber composition into a film using a calendar roll, or by attaching the thermosetting silicone rubber composition as a film onto a separator using a roll coater, knife coater, etc. Thereafter, this is heated and cured, and the material on the separator can be obtained by peeling it off. However, since this sheet is made into a leak-proof sheet by bonding with the fiber base described later, the film thickness is 10 to 10 cm.
The hardness is preferably in the range of 300 μm, and the JIS hardness is preferably 15 to 60 degrees from the viewpoint of flexibility, texture, anti-slip properties, durability, etc.
It is preferable to set the angle between 30 and 50 degrees. Note that as the silicone rubber composition for forming this silicone rubber thin film, an organopolysiloxane composition containing dimethylpolysiloxane as a main ingredient is used; A room-temperature curing type usually made by adding dimethylvinylphenylpolysiloxane, γ-trifluoropropylmethylvinylpolysiloxane, etc., and adding and mixing various fillers, pigments, property improvers, vulcanizing agents, catalysts, etc. (RTV), low-temperature curing rubber (LTV), or commercially available heat-curable rubbers, but among these, dry silica has excellent mechanical strength. It is recommended to use a medical or food grade silicone rubber composition containing the following. Next, the organopolysiloxane composition to be applied to this silicone rubber thin film is not particularly limited as long as it is liquid and curable; this may be either a so-called silicone varnish or a silicone rubber. However, since this is used for adhesion with the fiber base material described later, it is best to cure at a low temperature.From this point of view, it is recommended that this be cured at a low temperature. It is preferable to use RTV type or LTV type silicone rubber, but this can be prepared by a solution of a heat-curable silicone rubber composition in an organic solvent, or by diluting this with a low-molecular organosiloxane, or by a known method. It may also be a water-soluble emulsion of the produced organopolysiloxane. However, if the viscosity is too high, it will be inconvenient to use, so the viscosity measured at 25°C is preferably 5 to 2000 poise, preferably 50 to 500 poise. The fiber base material to be pressure-bonded with the silicone rubber thin film coated with the above-mentioned liquid organopolysiloxane in the method of this invention may be any material that can be used as a sheet base material, and therefore, the material etc. thereof are particularly limited. Although not required, since this is a leak-proof sheet, it should preferably contain at least 30% by weight of absorbent fibers, including materials with an official moisture content of 5% or more, such as cotton, rayon, or Kyupra. At least 30% hygroscopic fibers
It is better to include In addition, the fibrous material constituting this fiber base material may be any of woven fabrics, knitted fabrics, non-woven fabrics, paper-like materials, etc., but it is preferable that this is a non-woven fabric that has been subjected to needle treatment. When a silicone rubber thin film is pressure-bonded to a seed fiber base material, the fluff and fiber tufts present on the surface penetrate into the silicone rubber thin film, resulting in a strong adhesion, as well as capillarity of the fluff and fiber tufts. This provides an additional effect in that the liquid discharged onto the leak-proof sheet is quickly transported to the silicone rubber thin film surface. The leak-proof sheet is manufactured by the method of the present invention by applying a liquid organopolysiloxane composition to the silicone rubber thin film described above, then pressing this onto a fiber base material, and then curing this organosiloxane composition. This is done, for example, in the apparatus shown in the accompanying FIGS. 1 and 2. In FIG. 1, a liquid organopolysiloxane 2 is applied by a doctor knife 3 to a silicone rubber thin film 1 which is formed in advance by calendering or the like and is running on a substrate, and then a laminating roll 4 is applied to the liquid organopolysiloxane 2. The fiber base material 5 is crimped.
The thus obtained laminate consisting of the silicone rubber thin film, curable organopolysiloxane, and fiber base material is then placed in a hot air drying oven, where the organopolysiloxane is cured and the intended leak-proof sheet 7 is produced. be obtained. Moreover, FIG. 2 illustrates a method of continuously carrying out the process from manufacturing the silicone rubber thin film to manufacturing the leak-proof sheet. In this case, the separator 1 supplied from the separator supply roll 11 is
2 is run, and a room temperature curable silicone rubber composition 14 is applied thereto using a doctor knife 13. This is then vulcanized in a heating furnace 15 to form a silicone rubber thin film, and then a doctor knife 16 is applied to this.
A curable organopolysiloxane composition 17 is applied thereto, a fiber base material 19 is pressed onto it using a laminator roll 18, and then the composition is passed through a hot air drying oven 20 to cure the organopolysiloxane. Leak-proof sheet 21 obtained in this way
After being cooled by a cooling roll 22, it is separated from the separator 12 by a knife 23, and the leak-proof sheet 21 is wound onto a roll 24, and the separator 12 is wound onto a roll 25. In the above, the liquid organopolysiloxane composition and the room-temperature curable silicone rubber composition are applied using a doctor knife, but this may also be done using a conventionally known roll coater. is Teflon,
polyethylene, polypropylene, polyester,
Plastic films such as polyvinyl chloride and polyamideimide, or paper, as well as engineered paper whose surface is treated with plastic, are used; Preferably, it is paper. In addition, in the above, the liquid organopolysiloxane composition is applied and immediately bonded to the fiber base material, but depending on the type of organopolysiloxane composition, it may be placed in a hot air drying oven after being applied. The solvent and water may be evaporated in advance, or the organopolysiloxane composition may be partially vulcanized to increase its viscosity. The leak-proof sheet obtained by the method of the present invention has a uniform and smooth surface because the silicone rubber thin film is pre-formed without pinholes or scratches, and also has a liquid organopolysiloxane The penetration of the composition into the fiber base material and its anchoring effect cause the silicone rubber thin film and the fiber base material to be tightly adhered, resulting in excellent leak-proofing properties and durability. The rubber layer has excellent flexibility, elasticity, heat resistance, and weather resistance, as well as a large coefficient of friction, so it can withstand autoclaving, boiling sterilization with hot water, and drying in the sun, and can be used repeatedly. In addition, since it is non-slip, it also has the convenience of not having to fold the end into the bed during use. In addition, although the method of the present invention has been described above for the case where a silicone rubber thin film is pressure-bonded to one side of a fiber base material, it is also possible to pressure-bond a fiber base material to both sides of this silicone rubber thin film as necessary. The sheets made by the method of the present invention can be used not only as bed sheets in hospitals and facilities, but also as household items such as diapers, aprons, coasters, etc., and can also be used as industrial items such as tide protection sheets. can be used. Further, although the method of the present invention has been described above with respect to laminating a silicone rubber thin film and a fiber base material, it can also be used when a plastic foam is substituted for the silicone rubber thin film. Next, examples of the method of the present invention will be given. Example 1 A fiber web obtained by blending 75% rayon fiber and 25% polypropylene fiber was pricked to entangle these fibers, and then an adhesive was added and heat treated. As a result, a nonwoven fabric of 160 g/m ² was made. Next, using a coating knife, apply a room temperature curable silicone rubber composition KE1300RTV [manufactured by Shin-Etsu Chemical Co., Ltd.] to a process paper made of polyester film.
Product Name: 100 parts by weight, 20 parts by weight of thinner and hardening agent
A liquid composition with a viscosity of 250 poise mixed with 10 parts by weight was applied to a film thickness of 50 μm, and this was heated and cured in a hot air drying oven at 150°C for 2 minutes to form a silicone rubber thin film on process paper. It was molded into Next, the above liquid composition was applied again onto this silicone rubber thin film, and the nonwoven fabric obtained above was pressed onto this using a laminating roll, and this was heat-treated at 150°C for 5 minutes in a hot air drying oven. When this liquid composition was heated and cured, the nonwoven fabric had a silicone rubber thin film layer on one side, and the result was 260 g/m ^{2 .}
A sheet containing 100 g/m ² of silicone was obtained. This sheet has no pinholes or scratches in its silicone rubber thin film layer, and its surface is smooth and highly flexible.This is also because the nonwoven fabric and silicone rubber thin film are completely bonded, making it leak-proof. It had excellent physical properties as a sheet. The physical properties of the sheet thus obtained were tested in the following manner and compared with commercially available polyethylene laminate leak-proof sheets, and the results shown in Table 1 were obtained. (1) Washing test Dissolve 42g of synthetic detergent in 30℃ of warm water at 40℃,
Washing was carried out in this solution for 13 continuous hours. (2) Steam test The sample was treated in steam at 130°C for 5 hours. (3) Pinhole test Drop water colored with ink from the fiber base material surface, and judge whether this permeates and contaminates the paper that is in contact with the silicone rubber surface.

【table】

[Table] Example 2 The liquid composition used in the previous example was applied to the silicone rubber thin film layer of the leak-proof sheet obtained in the previous example, and then the nonwoven fabric obtained in the previous example was crimped onto this coated surface, and the same procedure was applied. When this liquid composition was cured by the method described above, sheets with a weight of 470 g/m ² (of which the silicone content was 150 g/m ² ) had a silicone rubber thin film with nonwoven fabric on both sides, and this sheet had excellent flexibility and water absorption. It has excellent physical properties as a leak-proof sheet.

[Brief explanation of the drawing]

The figures all show the method of the present invention, and Figure 1 is a schematic vertical cross-sectional view showing the steps of the method of the present invention, and Figure 2 is a schematic longitudinal cross-sectional view showing the steps of the method of the present invention.
The figure shows a schematic longitudinal section of the steps of the method according to the invention, including the step of producing a silicone rubber thin film layer. 1...Silicone rubber thin film, 2,17...Liquid organosiloxane composition, 3,13,16...
Doctor knife, 4, 18... Laminator roll, 5, 19... Fiber base material, 6, 15, 20...
Hot air drying oven, 7, 21...Leak-proof sheets, 12...
separator.

Claims (1)

[Claims] 1. Leak prevention characterized by applying a curable liquid organopolysiloxane composition to a silicone rubber thin film, pressing this onto a fiber base material, and then curing the liquid organopolysiloxane. How to make sheets. 2. The method for producing a leak-proof sheet according to claim 1, wherein the fiber base material contains at least 30% by weight of hygroscopic fibers.