JPS6128808A - Measuring method of strain of surface of rubber - Google Patents

Abstract

PURPOSE:To enable the measurement of a strain under wide-range conditions by a method wherein a grid pattern of a metal thin film is formed on the surface of rubber by evaporation, a halogenated film is formed thereafter on the top surface of the grid pattern, a transparent urethane coat is applied, and then the strain is measured. CONSTITUTION:A grid original plate 5 made of nickel and having 250 meshes is fitted closely and fixed on the surface of an oil seal 1 formed of nitrile rubber or the like, gold is evaporated thereon in vacuum, the original plate 5 is exfoliated, and thus a negative-form metal thin film 2 of the grid pattern is formed on the surface of the seal 1. Next, the top surface of the thin film 2 is halogenated directly by using chlorine and dried for 30min at the room temperature, and thereby a halogenated film 3 is formed. Moreover, a transparent urethane coat containing aliphatic polyisocyanate and polyol as main components is applied on the halogenated film 3, so as to form a coat 4. By this method, the exfoliation of an evaporated metal is prevented, and thus the measurement of a strain in a solution can be performed effectively.

Description

[Detailed Description of the Invention] Purpose of the Invention (Field of Industrial Application) The present invention relates to a method for measuring strain in a minute area on the surface of a sample based on a lattice pattern formed on the surface of the sample by a thin metal film. be.

(Prior art) Generally, when measuring the state of deformation on the surface of a rubber product (hereinafter referred to as the rubber surface), such as strain in a minute area, a grid pattern of an appropriate size is formed on the rubber surface in advance. ,
The lattice method is used to measure the lattice dimensions after deformation.

When forming this lattice pattern, the intervals between the lattice patterns are approximately 0.
Since it is necessary to make the size as small as 1+a+, a photo printing method has conventionally been used. However, in the case of this method, (1) the lattice pattern affects the original deformation of the rubber. - When stretched to a large deformation (approximately 50% or more), the lattice pattern peels off from the rubber surface and does not follow. ■There were problems such as the fact that forming the lattice pattern was time consuming and required additional skill.

Therefore, in order to solve this problem, a vacuum evaporation method was developed in which a lattice pattern is formed by vacuum evaporation as described below.

That is, in this method, a grid original plate is placed in close contact with the rubber surface, a metal such as aluminum or gold is vacuum-deposited thereon, and after the vapor deposition is completed, the grid original plate is removed from the rubber surface to form a grid pattern in a negative state.

However, when a lattice pattern is formed by this vacuum deposition method, the above problem can be solved, but it tends to peel off when immersed in a liquid. When measuring strain in a liquid such as oil using the above method, there is a problem in that the grid pattern peels off and measurement cannot be performed.

(Problems to be Solved by the Invention) The present invention was made to solve the problem that the grid pattern formed on the rubber surface by vacuum deposition peels off in liquid such as oil, making it impossible to measure strain. It is something that

Structure of the Invention (Means for Solving the Problems) In view of the above problems, the present invention forms a halogenated pattern on the upper surface of the lattice pattern, further forms a transparent or translucent urethane coating, and then, It is configured to measure strain.

(Function) The halogenated film firmly adheres the urethane coating to the rubber surface. This protects the lattice-patterned metal film from corrosion by touch or oil.

(Example) Hereinafter, an example in which the present invention is applied to a method for measuring strain in oil of an automobile oil seal formed by blending NBR with trill rubber will be described with reference to FIGS. 1 to 3.

FIG. 1 shows a cross section of an oil seal 1 with a lattice pattern according to the present embodiment. On the surface of the oil seal 1, a gold vapor deposited film 2 is formed with a uniform thickness by vacuum vapor deposition. A negative grid pattern with an interval of about Q and 1 mm is formed in between. A treated film 3 is formed on the upper surface of the vapor deposited film 2 by halogenation treatment in order to firmly adhere the urethane coating film 4 to the oil seal 1.
A transparent urethane coating film 4 is formed on the 1° upper surface of the lattice pattern metal thin film 2 to prevent it from being eroded by oil or the like.

Next, a method for forming the lattice pattern on the oil seal 1 will be described in detail.

First, oil seal 1 used in this example
is blended in the following parts by weight (hereinafter, parts by weight are referred to as parts).

NBR' to trill rubber) 100 parts carbon black 45 parts plasticizer
25 parts stearic acid
1 part ZnO' 5 parts vulcanizing agent 4 parts above N
The B'R formulation was vulcanized at 170° C. for 10 minutes to form oil seal 1.

Next, the metallic screen sheets 1 to 1 are cut to an appropriate size to create a grid original 5 as shown in FIG.

In this embodiment, a commercially available Nilarkel material with a grid spacing of 0.1 mm (2!50 meshes) is used.

The grating original plate 5 is placed closely on the measurement surface of the oil seal 1, and gold is vacuum-deposited with the periphery fixed with adhesive tape or the like. Then, the evaporated metal adheres to the surface of the A-il seal 1 and forms a evaporated film 2.

The vapor deposition conditions in this example include a degree of vacuum of 10 to 10-
+TOrr, and the thickness of the deposited film 2 is set to 0.01 to 0.05 μm.

When the lattice original 5 is peeled off, a negative lattice pattern is formed on the surface of the A-il seal 1 with the vapor deposited film 2 attached except for the lattice portions, as shown in FIG.

Further, the upper surface of the lattice pattern is subjected to halogenation treatment, and dried at room temperature for 30 minutes to form a halogenation treatment film 3.

The halogenation treatment includes methods using direct halogen, methods using hydrogen halide, methods using hypohalous acid, methods using nitrosyl chloride, methods using alkali hypochlorite, and methods using hypochlorite. Commonly used methods such as a method using t-butyl can be used, and in this example, halogenation treatment was directly performed with chlorine.

Subsequently, a transparent urethane paint containing aliphatic polyisocyanate and polyol as main components is applied onto the halogenated film 3 and dried to form a coating film 4. The urethane paint can be applied by brushing, spraying, dipping, dipping, etc. In this embodiment, dipping is used. It is necessary for the urethane coating film 4 to ensure that the grid pattern can be seen through the coating film 4, and in this embodiment, the dry film thickness is approximately 1 to 30 μm. The drying temperature after application can be set arbitrarily in the range from room temperature to about 80°C, and the drying time can be arbitrarily set in the range from about 30 minutes to about 24 hours. In this example, drying was performed at room temperature for 30 minutes. There is.

The aliphatic polyisocyanate, polyol, and organic solvent used in the paint will be explained in detail.

Examples of aliphatic polyisocyanates include hydrogenated products of 1.6-hexane diisocyanate, 4.4-diphenylmethane diisocyanate, isophorone diisocyanate, hydrogenated products of xylene diisocyanate, and xylene diisocyanate. For example, any one in which the isocyanate group is directly bonded to an aliphatic group may be used.

Examples of the polyol include polypropylene glycol, tetramethylene glycol, polyethylene adipate, polybutylene adipate, polyethylene-butylene adipate, etc., and any polyol that is generally used in the urethane industry may be used.

In addition, low-molecular polyols used for the purpose of improving adhesion, gasoline resistance, and heat resistance include ethyl glycol, propylene glycol, butylene glycol, pentamethylene glycol, 1°6-hexanediol, octyldiol, Examples include diethylene glycol, triethylene glycol, glycerin, and trimethylolpropane.

Examples of organic solvents include benzene, toluene, xylene, methyl acetate, ethyl acetate, isopropyl acetate, amethylate/methoxyketone/methylisopD (pyruketone, methylisobutylketone, 1.1°1-trichloroethane, etc.) can.

In this example, a urethane coating film containing the following parts by weight is used.

Aliphatic polyisocyanate 1.6-hequinane diisocyanate 33.6 parts Polyol polyethylene agitate (molecular weight approximately 2000)
200 parts Organic solvent toluene 233.6 parts The above mixture was reacted in dry nitrogen gas at 80° C. for 3 hours to synthesize the urethane paint.

In addition, in order to shorten the urethanization reaction time or the coating hardening time of the coating material, a catalyst such as triethylamine, triethylenediamine, dibutyldenediuralate, dibutyldenediacetate, etc. may be used.

In addition, in order to confirm the effects of this example, a test piece made of the oil seal 1 was prepared and the tests described below were conducted.

(2) Adhesion: The test piece was folded 180° and the presence or absence of peeling or cracking of the coating film 4 was visually determined.

(2) Followability: The test piece was stretched by 200%, and the presence or absence of peeling or cracking in the coating film 4 was visually determined.

■Measurability: A test piece was photographed at a magnification of approximately 10 times, and the clarity of the grid pattern transferred to the photographic film was visually judged when observed under a microscope.

As a result of the above tests, the vapor deposition #!
Sample No. 2 did not cause problems such as peeling and cracking.

Then, strain measurements were performed using the method described below. That is, the oil seal 1 is deformed by applying an external tensile or compressive force, and the lattice spacing before and after deformation is changed to 2.
Measure the amount by taking a photograph using a microscope or the like. The strain at this time is σ-(), if. )-1.

In this way, by forming the halogenated film 3 on the vapor deposited film 3 and further forming the urethane coating film 4, it is possible to prevent the film from coming into contact with hands or other parts, or being immersed in liquids such as gasoline or oil. Even if the vapor deposited film 2 is removed from the oil seal 1, the vapor deposited film 2 will not be peeled off from the oil seal 1.

Therefore, it is possible to measure strain over a wide range of environments such as in air and liquid.In particular, the swelling rate of the coating film 4 in gasoline is approximately the same as that of the oil seal 1, making it suitable for measuring strain in gasoline. There is.

Note that the urethane paint of this example can be changed to the following second to eighth formulation examples, and the same effects as those of this example can be obtained.

2nd formulation example Aliphatic polyisocyanate 1.6-hexane diisocyanate 67.2 parts Polyol polyethylene adipate (molecular weight approximately 2000)
200 parts Organic solvent Toluene 267.2 parts The urethane paint of the above formulation example was synthesized in the same manner as in the previous example.

Third formulation example Aliphatic polyisocyanate 1.6-hexane diisocyanate 80.64 parts Polyol polypropylene glycol (molecular weight approximately 2000>
200 parts Organic solvent Toluene 281.88 parts The urethane paint of the above formulation example was synthesized in the same manner as in the previous example.

Fourth Formulation Example A urethane paint was synthesized in the same manner as in the Third Formulation Example except that xylene diisocyanate was used instead of 1,6-hexane diisocyanate in the Third Formulation Example.

5th formulation example Aliphatic polyisocyanate 1.6-hexane diisocyanate [67, 2 parts polyol polyethylene adipate (molecule ω approximately 20 ON degree) 200
Part Organic Solvent Toluene 283.01 parts After reacting the above in dry nitrogen gas at 80'C for 3 hours,
15.81 parts of ethylene glycol was added and reacted again for 30 minutes in dry nitrogen gas at 80°C to synthesize a urethane paint.

6th formulation example Fat-linked polyisocyanate xylene diisocyanate 75.2 parts Polyol polypropylene glycol (molecular weight approximately 1000)
100 parts Organic solvent Toluene 191.01 parts After reacting the above material in nitrogen gas at 80°C for 3 hours, 15.81 parts of ethylene glycol was added and reacted again in dry nitrogen gas at 80°C for 3 hours. A urethane paint was synthesized.

7th formulation example Aliphatic polyisocyanate Hydrogenated 4.4-diphenylmethane diisocyanate 1 Polyol 32.5 (] Polypropylene glycol (molecular weight approximately 1000)
100 (1 organic solvent toluene 930g 30 parts The above mixture was reacted in dry nitrogen gas at 80°C for 3 hours, and then 24.8g of ethylene glycol was added and reacted in dry nitrogen gas at 80°C for 1 hour to produce urethane. Synthesized paint.

8th Formulation Example Aliphatic Polyisocyanate Hydrogenated 4,4-diphenylmethane diisocyanate

132.50 polyol polypropylene glycol (molecular weight approximately 1000)
100 () organic solvent toluene 930 g The above formulation was reacted in dry nitrogen gas at 80°C for 3 hours to synthesize a urethane prepolymer, and immediately before applying the urethane paint on the halogenated layer, urethane prepolymer 10
2.0 g of ethylene glycol. Og was added to make a urethane paint.

Note that the present invention is not limited to the above embodiments,
For example, it is also possible to do as follows.

■Instead of the rubber in the above example, CR (chloroprene rubber), '5BR (styrene, butadiene rubber), NR (
Use rubber such as natural rubber.

(2) Instead of the oil seal 1, parts that require oil resistance such as gaskets and oil-resistant hoses may be used.

(2) The present invention is not limited to the measurement in oil as in the embodiment described above, and the same effects as in the embodiment described above can be obtained even in measurement in air.

Effects of the Invention As detailed above, the present invention forms a halogenated film on the metal deposited on the rubber surface and further forms a urethane coating, thereby preventing the deposited metal from peeling off.
It has the excellent effect of making it possible to measure strain in solutions, especially in gasoline, and to make measurements possible under a wide range of conditions, such as in air and in solutions.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing an embodiment embodying the present invention;
FIG. 2 is a partial plan view of a grating original used in the present invention, and FIG. 3 is a partial cross-sectional view showing a grating pattern formed on the rubber surface by vacuum evaporation. Rubber 1, metal thin film 2, halogenated film 3, urethane coating film 4゜Patent applicant Toyoda Gosei Co., Ltd. Agent
Person Patent Attorney On 1) Hirosenmaru

Claims (1)

[Claims] 1. In a method for measuring strain in a minute area on a sample surface based on a lattice pattern formed by a metal thin film (2) on the surface of a rubber (1), the upper surface of the lattice pattern is halogenated. A method for measuring strain on a rubber surface, which comprises forming a treated pattern (3) and further forming a transparent or translucent urethane coating (4), and then measuring the strain. 2. The method for measuring strain on a rubber surface according to claim 1, wherein the metal thin film (2) is made of gold. 3. The method for measuring strain on a rubber surface according to claim 1, wherein the halogenated film (3) is directly halogenated with chlorine.