JPS594657A - Epoxy resin lining material for gas piping - Google Patents

Abstract

PURPOSE:The titled two-pack type lining material in combination with a mixed system of a curing agent, having improved film characteristics against deformation of pipe and resistance to gas, obtained by using a material prepared by reacting an epoxy resin with a carboxyl group-containing butadiene-acrylonitrile copolymer in a specific ratio. CONSTITUTION:For example, (A) an epoxy resin mixed system comprising 5- 75wt% resin (based on resin amount) obtained by reacting (i) an epoxy resin(preferably one having 100-3,500 epoxy equivalents and two or more epoxy groups in one molecule) with (ii) a carboxyl group-containing butadiene-acrylonitrile copolymer, and (iii) a copolymer such as one having carboxyl groups at both the end groups of the molecule is blended with (B) a mixed system of a curing agent in the weight ratio of the component A:B=(1:1)-(4:1), and, if necessary, (C) 0.1- 5pts.wt. (based on 100pts.wt. total amounts of the resins of both the mixed systems) silane coupling agent is added to at least one of the mixed systems, to give the desired lining material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an epoxy resin lining material used for the inner lining of gas piping.

A two-component epoxy resin composition consisting of a compounding system mainly composed of epoxy resin and a compounding system mainly consisting of a curing agent is made by mixing the above two compounding systems and applying it to the construction surface immediately before use. When cured, it forms coatings and other molded products with excellent heat resistance, anticorrosion properties, adhesive properties, etc. In recent years, attempts have been made to apply such two-component epoxy resin compositions as inner lining materials for gas piping.

The performance required for the inner lining material for gas piping is, from the viewpoint of workability, ■ good stirring and mixing properties, ■ long pot life and short curing time to the touch, and ■ wettability to the inner surface of the pipe. The coating film should have good coating properties and be non-sagging. In addition, from the viewpoint of the coating film properties after construction, ■Approximately 102 ~
It must have a coating thickness of 5X103μ, preferably 5XI02 to 2X103μ, ■It must completely cover the inner surface of the piping and will not cause gas leakage even when internal pressure is applied, and ■Deformation of the piping. The coating film follows well against ■
It has excellent resistance to gases in piping,
Examples include.

To date, in order to meet the above-mentioned requirements for workability, we have achieved a pot life of 60 minutes or more at the temperature at the time of construction (approximately 5 to 35 degrees Celsius) and a touch hardening time of less than 24 hours. The above-mentioned two-part epoxy resin composition is used, and has a viscosity of about 5×10 3 to 10 6 centipoise, more preferably around 10′ centipoise, and has appropriate thixotropic properties immediately after mixing. It satisfied the characteristics. However, in terms of coating film properties after construction, in particular, it cannot fully meet the requirements of (1) above.
It was not possible to follow these fluctuations well, and as a result, the lining coating film was damaged, destroyed, and peeled off, making it impossible to put it into practical use (in many cases).

For this reason, efforts have been made to impart flexibility to the lining coating film to improve its ability to follow deformation. For example, as an epoxy resin in an epoxy resin compounding system, a flexible epoxy resin such as a glycidyl ester type epoxy resin such as dimer acid diglycidyl ester or a polyalkylene glycol diglycidyl ether type epoxy resin such as polyethylene glycol diglycidyl ether is used, A method of using this in combination with a flexible curing agent such as a long chain polyamide amine curing agent or a polyether polyamine curing agent is known.

According to the above method, it is possible to obtain a product with excellent flexibility such that the elongation at break is 50% or more, but by increasing the flexibility in this way, the gas resistance deteriorates. There is a problem that the above-mentioned requirement (2) cannot be satisfied, and the coating film swells and peels over time.

In addition, as a flexible curing agent other than the above, butadiene-
An amine modified with acrylonitrile rubber has been proposed, but even in this case, even though it imparts flexibility, a sufficient effect on gas resistance has not been found. It was difficult to satisfy them at the same time.

Therefore, as a result of intensive investigation into a epoxy resin lining material that satisfies both (1) and (2) among the above-mentioned required characteristics, the inventors found that a specific resin was added in a specific proportion as the resin component in the epoxy resin compound system. The present invention was made based on the knowledge that very good results can be obtained in the above-mentioned required characteristics by using this method.

That is, the present invention provides a two-type epoxy resin lining material containing an epoxy resin compound system and a curing agent compound system applied to the inner surface of gas piping, in which the resin content of the epoxy resin compound system is 5 to 75%. Gas piping work J! is characterized in that the weight percentage is made of a resin obtained by reacting an epoxy resin with a carboxyl group-containing butadiene-acrylon copolymer (hereinafter simply referred to as a BN-modified epoxy resin). An epoxy resin-based lining material for gas piping, characterized in that a silane-based coupling agent is further blended into at least one of the above-mentioned specific epoxy resin-based lining material and a curing agent-based lining material; This is related to.

The resin content of the epoxy resin compounding system of this invention (hereinafter referred to as B)
In addition to containing N-modified epoxy resins and unmodified epoxy resins, various thermosetting resins or thermoplastic resins that are compatible with these resins are included as necessary. Typical thermosetting resins include phenyl resin, phenolic resin, xylene resin, furan resin, etc. Examples of thermoplastic resins include polyester resin, ethylene-vinyl acetate copolymer, thiocol resin, and ionomer. Examples include resins, modified butadiene-acrylonitrile resins, vinyl acetate, coal tar, asphalt pitch, and other coal-9 petroleum residue resins.

A BN-modified epoxy resin is obtained by reacting an epoxy resin with a carboxyl group-containing butadiene-acrylic nitrile copolymer at a temperature of, for example, around 150°C. As such, those having carboxyl groups at both ends of the molecule represented by the following general formula are suitable.

Furthermore, as the epoxy resin to be reacted with such a copolymer, a bisphenol type epoxy resin is usually used. The epoxy equivalent is about 100 to 3,500,
Those containing an average of two or more epoxy groups in one molecule are preferred. As epoxy resins other than those mentioned above, cycloaliphatic epoxy resins, novolac type epoxy resins, glycidyl ester type epoxy resins, glycidyl ether type epoxy resins, polyglycol type epoxy resins, etc. can also be used.

As the unmodified epoxy resin used in combination with the BN-modified epoxy resin, a bisphenol-type epoxy resin is generally preferably used, as in the case of the above-mentioned BN-modified epoxy resin. It is also preferable to use a flexible epoxy resin such as a glycidyl ester type epoxy resin or a polyglycol type epoxy resin together with this bisphenol type epoxy resin. However, the amount of flexible epoxy resin used is preferably 30% by weight or less of the total amount of epoxy resin (including the epoxy resin as a raw material for synthesizing the BN-modified epoxy resin). If the amount is more than this, there is a risk of causing a problem in gas resistance.

The proportion of the BN-modified epoxy resin in the resin content of such an epoxy resin compounding system is 5 to 75% by weight, preferably 15 to 65% by weight, and by setting it within this range, the lining coating can be improved. It has been found that good results can be obtained in both the flexibility and gas resistance of the membrane. On the other hand, if the above proportion is less than 5% by weight or 75% by weight
Exceeding this value will result in a significant loss of either flexibility or gas resistance.

In addition to the following resin components, the epoxy resin compound system of this invention includes non-reactive diluents such as dibutyl 7-thaleate, dioctyl phthalate, furfuryl alcohol, and methanol, silica, clay, coal powder, calcium carbonate, and asbestos. Known additives such as fillers and fluidity regulators are added depending on the purpose of use. These components have a resin content of 10
It is usually used in a range of 1 to 300 parts by weight per 0 parts by weight.

Further, as the curing agent in the curing agent compounding system applied to this invention, polyamide amine, polyamide, aromatic amine, polyether polyamine, polyalkylene polyamine, butadiene-acrylonitrile rubber modified amine,
Examples include amine-modified adducts, ketimine, amine-containing adducts, separated adducts, imidazole, and guanidine.

Among these hardening agents, flexible modifiers such as butadiene-acrylonitrile rubber-modified amines, long-chain polyamide amines, and polyether polyamines account for 30% by weight of the total hardening agents.
The following ratios are recommended.

If the amount exceeds this range, problems will arise in the gas resistance of the lining coating.

This curing agent compounding system contains such a curing agent as a main component, and the same known additives as in the resin compounding system, such as fillers and fluidity regulators, are mixed therein depending on the purpose of use. These components are usually used in an amount of 1 to 300 parts by weight based on 100 parts by weight of the main component of the curing agent.

In the two-component epoxy resin lining material of this invention, the blending ratio of the epoxy resin blend system and the curing agent blend system is as follows:
Generally, the ratio of epoxy resin blending system to curing agent blending system is 1=
It is preferable to set the ratio to be in the range of 1 to 4:1.

In this invention, it is possible to obtain sufficiently satisfactory flexibility and fluid resistance (gas resistance) with the above configuration, but in order to further improve both characteristics and gas resistance,
A silane coupling agent can be blended into at least one of the epoxy resin blending system and the curing agent blending system.

This silane coupling agent improves adhesion on the substrate surface by reacting with the reactive groups on the substrate surface of the broken adherend and the reactive groups contained in the resin, and also improves adhesion on the substrate surface before and after curing. It also brings about good results in water repellency and liquid repellency at the substrate interface, which contributes to improving gas resistance and adhesion.

Such silane coupling agents include, for example, the general formula
(For example, hydrolyzable groups such as halogen and alkoxy groups)
Silane compounds represented by the following are preferred, and specific examples thereof include γ-aminopyropyrutriethoxysilane and vinyl-triacetoxysilane.

The amount of these silane coupling agents to be used is approximately 0.1 to 5 parts by weight per 100 parts by weight of the total amount of the resin constituting the epoxy resin compound system and the resin constituting the curing agent compound system. Good. If the amount is too small, the effect of improving gas resistance or adhesion will be poor, and if it is too large, the adhesion will actually decrease and the gas resistance will not be good.

According to the research of the inventor of Dome, in order to have sufficient ability to follow the deformation of external and internal forces that gas piping receives, the inner lining material usually has a tensile elongation at break of 30% or more. In addition, as for durability against the gas fluid contents in the piping, the weight change rate after being immersed in the atmosphere of the fluid contents or in the fluid contents model compound (liquid) for one month is usually 20% or less. is required.

In this invention, as already detailed, the BN-modified epoxy resin is used in a specific proportion as the resin component of the epoxy resin compound system, so that the above-mentioned tensile elongation at break can be increased to 30% or more. Moreover, the rate of weight change in the atmosphere of the fluid contents can be suppressed to 20% or less.

This is very clear from the examples described later.

As detailed above, the two-component epoxy resin lining material of the present invention has sufficient flexibility to respond to external forces and internal deformation that gas piping receives, and has sufficient resistance to gas fluid flowing inside the gas piping. Because of its excellent durability, it is extremely effective as an inner lining material for pipes containing propane gas or other chemical gases.

The lining material of this invention can be applied by a lining method using a pig method in which a painting pig is pumped or indexed, or by a jet lining method or a spray lining method in which the viscosity is appropriately adjusted with an epoxy resin thinner mixed with toluene, methyl isobutyl ketone, etc. In addition to being used as a direct lining for the inner surface of piping, it is also used as an adhesive lining material in a construction method in which pre-formed tubes are loaded inside the piping.

Examples of this invention will be described below. In the following, parts refer to parts by weight.

Example 1 80 parts of Epikote #828 (bisphenol type epoxy resin manufactured by Yuka Shell Teboxy Co., Ltd.) and Hiker C BN1
A 13N modified epoxy resin was produced by reacting 20 parts of 300X8 (B, F, butadiene-acrylonitrile copolymer rubber containing carboxyl groups at both ends, manufactured by Gutdrich) in a melting and mixing pot at 140°C for 2.5 hours. Obtained.

50 parts of this BN modified epoxy resin, Epicoat #828
(mentioned above) 35 parts, S'R-TPG (polyglycol type epoxy resin manufactured by Hanhon Yakuhin Kogyo Co., Ltd.) 15 parts, Titanium White R-650 (manufactured by Sakai Chemical Industry Co., Ltd.) 50 parts, Neutron (
Talc (manufactured by Takehara Chemical Industry Co., Ltd.) 30 parts, Aerosil $38
0 (fine powder silica manufactured by Nippon Aerosil Co., Ltd.) 2 parts and silane coupling agent KBM#403 (manufactured by Shin-Etsu Chemical Co., Ltd.) 1 part
The epoxy resin blending system was prepared by mixing the two parts at room temperature using a Brantley mixer.

Next, 35 parts of Sanmide $301-D Kai 2 (long chain polyamide amine manufactured by Sansho Kagaku Co., Ltd.), 65 parts of Sanmide 76T (polyamide amine manufactured by Sansho Kagaku Co., Ltd.), and Titanium White R-6
50 (mentioned above), 40 parts of Hytron (mentioned above), and 3 parts of Aerosil #380 (mentioned above) were mixed at room temperature using a plantar mixer to prepare a curing agent compounding system.

A two-component epoxy resin lining material of the present invention was obtained by using the above-mentioned epoxy resin blend system and curing agent blend system in a weight ratio of l=1.

Example 2 25 parts of BN modified epoxy resin obtained in Example 1, 65 parts of Epicoat #828 (mentioned above), 10 parts of 5R-TPO (mentioned above)
70 parts, quartz powder 3H (manufactured by Nagase Sangyo Co., Ltd.), Hytron (
15 parts of Aerosil #380 (mentioned above) and 2.5 parts of Aerosil #380 (mentioned above) were mixed in a Brantley mixer at room temperature to prepare an epoxy resin blend system.

Next, 75 copies of Sunmide 76T (mentioned above), Hiker AT
25 parts BN1300 Mixing was performed using a tally mixer to prepare a curing agent blend system.

Above) A two-component epoxy resin lining material of the present invention was obtained by using the own epoxy resin blend system and curing agent blend system in a weight ratio of 1:1.

Example 3 65 parts of BN modified epoxy resin obtained in Example 1, 20 parts of Epicote $828 (mentioned above), 10 parts of 5R-TPO (mentioned above)
1 part, 70 parts of quartz powder 311 (mentioned above), 15 parts of Noritron (mentioned above), 2.5 parts of Aerosil #380 (mentioned above), and 0.8 parts of silane coupling agent (mentioned above) at room temperature. The mixture was mixed using a Brantley mixer to prepare an epoxy resin blend system.

Next, 70 copies of Sunmide 76T (mentioned above), Sunmide #
301-D Kai 2 (mentioned above) 20 copies, Epomitsu'ri Q-69
2 (polyether polyamine manufactured by Mikata Petrochemical Epoxy Co., Ltd.) 10 parts, S talc (mentioned above) 100 parts, Aerosil $
380 (mentioned above) were mixed in a Brantley mixer at room temperature to prepare a curing agent blend system.

A two-component epoxy resin lining material of the present invention was obtained by using the above-mentioned epoxy resin blend system and curing agent blend system in a weight ratio of 2=1.

Comparative Example 1 85 parts of Epicote #828 (mentioned above), 15 parts of 5R-TPG (stated above), 50 parts of Titanium White R-650 (stated above), 30 parts of Hytron (stated above), Aerosil #380 (stated above)
2 parts and 1 part of silane coupling agent #380 (described above) were mixed in a Brantley mixer at room temperature to prepare an epoxy resin blend system.

This epoxy resin blend system and the curing agent blend system of Example 1 were used at a weight ratio of 1:1 to produce a two-component epoxy resin lining material.

Comparative Example 2 Hiker ATBN 1300X16 (above) 45 parts, Epomic Q692 (above) 40 parts, Sanmide #3
0112 (mentioned above), 80 parts of S talc (mentioned above), and 2.5 parts of Aerosil #380 (mentioned above) were mixed in a Brantley mixer at room temperature to prepare a curing agent compounding system.

A two-component epoxy resin lining material was prepared by using the epoxy resin blending system of Comparative Example 1 and the curing agent blending system described above in a weight ratio of 1=1.

Comparative Example 3 85 parts of BN-modified epoxy resin obtained in Example 1, 5R-
15 parts of TPO (mentioned above), 5 parts of titanium white R-650 (mentioned above)
0 parts, No1 Itron (mentioned above) 30 parts, Aerosil 138
0 (mentioned above) were mixed using a trowel Brantley mixer at room temperature (17) to prepare an epoxy resin composition system.

This epoxy resin blend system and the cured UL blend system of Example 2 were used in a weight ratio of 1:1 to produce a two-component epoxy resin lining material.

The following tests were conducted to examine the characteristics of each of the lining materials of Examples 1 to 3 and Comparative Examples 1 to 3.

1) Tensile elongation at break: The epoxy resin blend system and curing agent blend system of each lining material were mixed, hardened and punched into No. 2 dumbbells specified in JISK-7113, and tested using a tensile tester at 23°C. Measurement was performed under the condition of 1 acclimatization/min.

2) Weight change rate; mix the epoxy resin blending system and curing agent blending system of each lining material, 1.5+rgrl thickness x 5
It was hardened and molded to 0 standard width x 50 standard length. This was used as a model test for gas durability.A) Weight change rate after immersion in a mixed solution of 30 volume% benzene and 70 volume% isooctane at 23℃ for 30 days, and 1)) Weight change rate after 30 days in distilled water at 23℃ The rate of weight change after immersion for one day was measured.

The results of each test were as shown in the table below.

As is clear from the table above, the lining material of the present invention has a tensile elongation at break of 30% or more, which is required for the inner lining of gas piping, and moreover, it has a tensile elongation at break of 20% or more when immersed in a model compound of gas fluid. The following superposition change rate is shown, and it can be seen that it is extremely practical for gas piping.

Claims (2)

[Claims] (1) In a two-component epoxy resin lining material with an epoxy resin compound system and a curing agent compound system applied to the inner surface of gas piping, 5% of the resin content of the above epoxy resin compound system
An epoxy resin lining material for gas piping, characterized in that ~75% by weight consists of a resin obtained by reacting an epoxy resin with a butadiene-acrylonitrile copolymer containing a carboxyl group. (2) In a two-component epoxy resin lining material containing an epoxy resin compound system and a curing agent compound system applied to the inner surface of gas piping, the resin content of the above epoxy resin compound system is 5 to 5%.
75% by weight consists of a resin obtained by the reaction of an epoxy resin and a carboxyl group-containing butadiene-acrylonitrile copolymer, and at least one of the epoxy resin compounding system in parentheses and the curing agent compounding system is silane-based coupling. The total amount of resin in both formulations is 1.
An epoxy resin lining material for gas piping, characterized in that the lining material is set in a range of 0.1 to 5 times with respect to 00iiJFt part.