JPH034595B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] This invention relates to a sealant for sealant cartridges.

More specifically, the present invention relates to a sealant to be sealed between a cylindrical body of a sealant cartridge and a plunger.

[Prior art] Sealants are used to seal joints, gaps, and cracks in civil engineering buildings, automobiles, trains, aircraft, water tanks, electrical and electronic equipment, and other devices, as well as to bond between various parts. Widely used.

Sealants are usually liquid or paste, and dry or harden to become solid, particularly elastomer, and are sold sealed in containers such as tubes or cartridges.

The cartridge for this purpose has a discharge part on the front end side of the cylindrical body, a plunger is slidably fitted in the rear end part, and a seal is formed between the inner circumferential surface of the cylindrical body and the outer circumferential surface of the plunger. agent is enclosed.

As the sealant, silicone oil (Tokukosho
50-35339), polyethylene-based microcrystalline wax, grease or latex (see JP-A-52-60778), alkyl-modified polysiloxane wax (see JP-A-59-115271)
etc. are known.

[Problems to be solved by the invention] However, silicone oil tends to leak, and polyethylene-based microcrystalline waxes and alkyl-modified polysiloxane waxes tend to crack at low temperatures, and have low sliding properties at low to room temperatures. However, green and latex have the disadvantage that their constituents can contaminate the sealant.

Therefore, the present inventors conducted intensive research to develop a sealant free from such drawbacks, and as a result, they arrived at the present invention.

An object of the present invention is to provide a sealant for a sealant cartridge that does not leak or crack, has excellent sealing properties and sliding properties over a wide temperature range, and does not contaminate the sealant.

[Means for solving the problems and their effects] The purpose is to seal between the inner circumferential surface of the cylindrical body of the sealant cartridge and the outer circumferential surface of the plunger that is slidably fitted into the cylindrical body. In the sealant for
10% by weight and polybutene or polyisobutylene
This is achieved by forming a mixture consisting of 10 to 90% by weight.

To explain this, the sealant sealed between the inner circumferential surface of the cylindrical body of the sealant cartridge and the outer circumferential surface of the plunger that is slidably fitted into the cylindrical body is made of wax 90~ 10% by weight and 10-90% by weight of polybutene or polyisobutylene.

Here, the sealant cartridge may be of any type as long as it has a discharge part on the front end side of the cylindrical body and a plunger is slidably fitted in the rear end.

The cylindrical body is usually cylindrical and is made of, for example, a plastic such as polyethylene or polypropylene;
Polyethylene-coated cardboard: Aluminum foil-coated cardboard: Made of airtight and shape-retaining materials such as aluminum sheets.

The discharge part is located on the distal end side of the cylindrical main body, and usually projects toward the distal end.

Examples of the discharge part include a nozzle-shaped part molded integrally with the cylindrical main body, and a separately molded nozzle screwed into a discharge port located at the center of the discharge part. A plunger is slidably fitted within the rear end of the cylindrical body.

Plungers are usually made of plastic, such as polyethylene or polypropylene.

The plunger has a shape such that its outer circumferential surface is in close contact with the inner circumferential surface of the cylindrical body and can slide within the cylindrical body in its longitudinal direction. When the cylindrical body is cylindrical, the plunger is also shaped like a round cylinder, and its discharge side is closed.
The opposite side is generally open.

A sealant is stored in a space closed by the discharge part and the plunger.

As a sealant, silicone sealant,
Products such as polyurethane sealants, polysulfide sealants, and silane-modified polyether sealants harden into elastomers when discharged into the atmosphere, while acrylic sealants and butyl rubber sealants dry when discharged into the atmosphere. Examples include those that are solid.

The sealant sealed between the inner peripheral surface of the cylindrical body and the outer peripheral surface of the plunger prevents atmospheric moisture and oxygen from entering the cartridge, and prevents components in the sealant from leaking out of the cartridge. Prevent volatilization.

Since the sealant contains wax and polybutene or polyisobutylene in a predetermined ratio, it is a viscous plastic material at around room temperature, and becomes fluid when heated above the melting point of the wax. The preferred penetration degree of the sealant is 40 to 400 at 25°C according to JIS K2207.

The wax plays a central role in the sealing action of the sealant, and may be any of petroleum wax, natural wax, and synthetic wax, as long as it is solid at room temperature.

Examples of petroleum waxes include paraffin wax and microcrystalline wax; examples of natural waxes include plant-based waxes, animal-based waxes, and mineral-based waxes; and examples of synthetic waxes include polyethylene waxes and long-chain alkyl-modified polyester waxes. Examples include siloxane wax and modified wax.

If the wax has a low melting point, it will flow out of the cartridge or flow into the sealant during high temperatures in summer, so the melting point is preferably 45°C or higher, more preferably 60°C or higher. In addition, if the melting point is too high, it will not be easy to apply the coating to the inner peripheral surface of the cylindrical body of the cartridge.
The temperature is preferably 150°C or lower, more preferably 120°C or lower.

Polybutene and polyisobutylene have the effect of turning the wax into a viscous plastic substance, thereby improving the sealing properties and durability of the sealant.

Polybutene is mainly composed of isobutylene from the butane-butene fraction produced by naphtha decomposition.
It is a long-chain hydrocarbon partially copolymerized with n-butene, etc., and the double bond may remain at one end of the molecular chain, or the double bond may be removed by hydrogenation.

Polyisobutylene is a linear hydrocarbon obtained by polymerizing isobutylene, and may have a double bond remaining at one end of the molecular chain.

Both polybutene and polyisobutylene are preferably liquid or raw rubber-like at room temperature, and liquid ones are particularly preferred. Specifically, it is preferable that the kinematic viscosity at 40°C is in the range of 10 cst to 1 million cst.

The blending ratio of wax and polybutene or polyisobutylene is 90 to 10% by weight of wax and 10 to 90% by weight of polybutene or polyisobutylene.

This is because if the wax content exceeds 90% by weight, the adhesiveness will be poor, and if the content is less than 10% by weight, it will become fluid even at room temperature and the position of the plunger will tend to move. From this point of view, wax 80-30% by weight, polybutene or polyisobutylene 20-20%
70% by weight is well preferred.

Different types of wax, polybutene, or polyisobutylene may be used as a mixture, or waxes of the same type but with different melting points or viscosities may be used as a mixture.

In addition to wax and polybutene or polyisobutylene, one or more additives such as dyes, pigments, fillers, and antioxidants may be added to the sealant of the present invention, if necessary.

The sealant of the present invention can be easily produced by mixing or kneading wax, polybutene or polyisobutylene, and other additives as necessary at a temperature higher than the melting point of the wax.

In order to encapsulate the sealant of the present invention between the inner circumferential surface of the cylindrical body of the sealant cartridge and the outer circumferential surface of the plunger that is slidably fitted into the cylindrical body, the sealant is heated. The liquid may be applied to the inner circumferential surface of the cylindrical body or the outer circumferential surface of the plunger using a brush, brush, spatula, or roll, and the plunger may be inserted into the cylindrical body.

[Examples] Examples and comparative examples of the present invention will be described. In Examples and Comparative Examples, "parts" means parts by weight. Penetration is a value according to JIS K2207.

Example 1 In a mixer, 70 parts of commercially available paraffin wax (melting point 69°C, penetration at 25°C 15, penetration at 35°C 20, kinematic viscosity at 100°C 6.4cst) were mixed with 100 parts.
Melt by heating to 30 °C and commercially available polybutene (average molecular weight 545, kinematic viscosity at 40 °C 645 cst, kinematic viscosity at 100 °C 28 cst, specific gravity 8.67, pour point -17.5 °C).
and mixed at 100°C until uniform.
This mixture was a colorless and transparent fluid.

Apply this mixture thinly on the inner circumferential surface of the polyethylene cylindrical body of the sealant cartridge within a range of 0.5 cm to 3.0 cm from the rearmost end, and insert a polyethylene plunger with a depth of 2.5 cm into the rearmost opening of the cylindrical body. The plunger was inserted so that the rearmost end of the plunger was 0.5 cm from the rearmost end of the cylindrical body. The applied mixture was allowed to stand until the temperature reached room temperature. The mixture at room temperature was a cloudy, fairly viscous plastic.

In the thus obtained sealant cartridge, the sealant did not flow out of the cylindrical main body or flow into the sealant housing within the range of 0°C to 60°C. In addition, it was possible to load the plunger into a manual caulking gun and a pneumatic caulking gun and smoothly slide the plunger toward the discharge section. At that time, no cracks were formed in the sealant, and no debris entered the sealant housing. For comparison, only the above-mentioned paraffin wax was heated to 100° C. and melted, sealed between the cylindrical body and the plunger in the same manner as above, and allowed to cool to solidify the wax.

The sealant cartridge thus obtained was loaded with a manual caulking gun and a pneumatic caulking gun, and an attempt was made to move the plunger toward the discharge portion, but the plunger did not move easily. Once it started moving, the wax cracked and debris got into the sealant compartment.

Example 2 Commercially available microlistaline wax (melting point 95°C, kinematic viscosity at 100°C 14.1cst, 25°C
50 parts of commercially available polybutene (average molecular weight 970, kinematic viscosity at 40°C 9.600 cst, kinematic viscosity at 100°C
220cst, specific gravity 0.890, pour point -7.5°C) was added and mixed at 120°C until uniform. This liquid mixture was a colorless and transparent fluid.

0.5cm to 2.5cm from the rear end of the aluminum foil-coated cardboard cylindrical body of the sealant cartridge
Apply this mixture thinly on the inner peripheral surface of the cylindrical body, and insert a polyethylene plunger with a depth of 2.5 cm through the rearmost opening of the cylindrical body so that the rearmost end of the plunger meets the rearmost end of the cylindrical body. I tried to get it all together. The applied mixture was allowed to stand until the temperature reached room temperature. The mixture at room temperature was a cloudy, viscous plastic.

In the thus obtained sealant cartridge, the sealant did not flow out of the cylindrical main body or flow into the sealant housing at a temperature of 0°C to 80°C. In addition, it was possible to load the plunger into a manual caulking gun and a pneumatic caulking gun and smoothly slide the plunger toward the discharge section. At that time, no cracks were formed in the sealant, and no debris entered the sealant housing. For comparison, only the above microcrystalline wax was used.
The wax was heated to 120° C. to melt it, sealed between the cylindrical body and the plunger in the same manner as above, and allowed to cool to solidify the wax.

The sealant cartridge thus obtained was loaded into a manual caulking gun and a pneumatic caulking gun, and an attempt was made to move the plunger toward the discharge portion, but the plunger did not move easily. Once it started moving, the wax cracked and debris got into the sealant compartment.

Example 3 Microlistaline wax (melting point 83°C, kinematic viscosity at 100°C 17.3cst, 25°C
Heat 40 parts of commercially available polydethene (average molecular weight 1350, kinematic viscosity at 40°C 28,000 cst, kinematic viscosity at 100°C
60 parts (590 cst, specific gravity 0.898, pour point 2.5°C) were added and mixed well at 95°C until uniform. This mixture was a colorless and transparent fluid.

Apply this mixture thinly on the inner peripheral surface within 3.0 cm from the rearmost end of the polyethylene cylindrical body of the sealant cartridge, and insert a polyethylene plunger with a depth of 3.0cm from the rearmost opening of the cylindrical body. so that the rearmost end of the plunger was aligned with the rearmost end of the cylindrical body. The applied mixture was allowed to stand until the temperature reached room temperature. The mixture at room temperature was a cloudy, viscous plastic.

In the sealant cartridge thus obtained, the sealant did not flow out of the cylindrical main body or flow into the sealant housing in the range of 0°C to 53°C. In addition, it was possible to load the plunger into a manual caulking gun and a pneumatic caulking gun and smoothly slide the plunger toward the discharge section. At that time, no cracks were formed in the sealant, and no debris entered the sealant housing.

For comparison, only the above-mentioned microcrystalline wax was heated to 95° C. to melt it, sealed between the cylindrical body and the plunger in the same manner as above, and allowed to cool to solidify the wax. The sealant cartridge thus obtained was loaded into a manual caulking gun and a pneumatic caulking gun, and the plunger tried to move toward the discharge portion, but it did not move easily. Once it started moving, the wax cracked and debris got into the sealant compartment.

Example 4 In a mixer, a commercially available polyethylene-based microlistalline wax (molecular weight 900, melting point 116°C,
Penetration at 25°C 2) Heat 35 parts to 130°C to melt and use commercially available polyisobutylene (average molecular weight
Kinematic viscosity at 30,000, 160℃ 20,000cst, 200
65 parts (kinematic viscosity at 6,500 cst at 25°C, penetration at 25°C 217, pour point 67.5°C) were added and mixed well at 130°C until uniform. This mixture was a colorless and transparent viscous fluid.

Apply this mixture thinly on the inner peripheral surface within 2.0 cm from the rearmost end of the polyethylene cylindrical body of the sealant cartridge, and insert a polyethylene plunger with a depth of 2.5cm from the rearmost opening of the cylindrical body. so that the rearmost end of the plunger was aligned with the rearmost end of the cylindrical body.

The sealed mixture was allowed to cool until the temperature reached room temperature. The mixture at room temperature was a cloudy, viscous plastic.

In the thus obtained sealant cartridge, the sealant did not flow out of the cylindrical main body or flow into the sealant housing at a temperature of 0°C to 105°C. In addition, it was possible to load the plunger into a manual caulking gun and a pneumatic caulking gun and smoothly slide the plunger toward the discharge section. At that time, no cracks were formed in the sealant, and no debris entered the sealant housing.

For comparison, only the polyethylene-based microcrystalline wax was heated to 130° C. to melt it, sealed between the cylindrical body and the plunger in the same manner as above, and allowed to cool to solidify the wax. The sealant cartridge thus obtained was loaded into a manual caulking gun and a pneumatic caulking gun, and an attempt was made to move the plunger toward the discharge portion, but the plunger did not move easily. Once it started moving, the wax cracked and debris entered the sealant storage compartment.

Example 5 A commercially available oxime-free liquid silicone sealant was injected into the cylindrical body of the sealant cartridge coated with a mixture of wax and polybutene or polyisobutylene as the sealant of Examples 1 to 4. A polyethylene plunger was inserted into the rearmost opening of the cylindrical body, the tube was sealed, and the tube was placed in an atmosphere of 40° C. and 90% RH to examine its storage stability.

None of the silicone sealants in the cartridges hardened or changed in quality even after 90 days. This means that it has not hardened or deteriorated after being left at room temperature for 12 months.

[Effects of the Invention] The sealant for sealant cartridges of the present invention is composed of 90 to 10% by weight of wax and 10 to 90% by weight of polybutene or polyisobutylene. The sealant will not flow out, and the sealed sealant will not flow out or contaminate the sealant while handling the filled sealant cartridge, and the sealant cartridge can be loaded into a caulking gun and the sealant can be discharged. It is characterized by smooth sliding of the plunger and excellent storage stability of the sealant.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a sealant cartridge sealed with the sealant of Example 1. DESCRIPTION OF SYMBOLS 1... Sealant cartridge, 2... Discharge part, 3... Cylindrical body, 4... Plunger, 5
...Sealant, 6...Sealant storage section.

Claims (1)

[Scope of Claims] 1. A sealant for sealing between the inner peripheral surface of a cylindrical body of a sealant cartridge and the outer peripheral surface of a plunger slidably fitted into the cylindrical body, A sealant for a sealant cartridge, characterized in that the sealant is a mixture of 90 to 10% by weight of wax and 10 to 90% by weight of polybutene or polyisobutylene. 2. The sealant according to claim 1, wherein the wax has a melting point of 45°C or higher. 3. The sealant according to claim 1, wherein the polybutene or polyisobutylene is liquid at room temperature.