KR102256280B1 - Unsaturated polyester resin composition for repairing underground pipes by non-digging, reducing VOC emission level, and enhancing the work environment - Google Patents

Abstract

As a resin composition for repairing low-odor non-digging pipelines, maleic anhydride (Maleic anhydride) 5-20 wt%, isophthalic acid (Isophthalic acid) 10-30 wt%, propylene glycol (Propylene glycol) 5-20 wt%, neopentyl glycol (Neopentil glycol) 5 to 20% by weight, Tripropyleneglycol diacrylate (TPGDA) 40 to 50% by weight, catalyst 0.002 to 0.02% by weight, hydroquinone 0.002 to 0.02% by weight, silica fume (Silica) Humed) 0.5 to 2% by weight, and 0.1 to 0.5% by weight of a thixotropic agent anti-settling agent, the low odor non-excavated pipe repair resin composition.

Description

Unsaturated polyester resin composition for repairing underground pipes by non-digging, reducing VOC emission level, and enhancing the work environment}

The present invention does not use styrene that emits volatile organic compounds (VOC) in the case of tube impregnation for pipe repair or curing process, maintains mechanical properties and obtains easy-to-operate viscosity, It relates to a resin composition for repairing a low-odor non-excavated pipeline that can improve the environment.

Various water and sewage pipelines buried underground become old and corroded over time. In the case of these old water pipelines, a huge amount of water leaks or rust is introduced and becomes contaminated. In the case of old sewage pipelines, when cracks occur, sewage flows out of the pipeline and contaminates soil and groundwater, causing environmental pollution problems. do.

In repairing an old buried pipeline that has cracks, etc., the non-excavated pipeline repair method, which inserts a tube into an old buried pipeline that has cracks without digging the ground to form a new composite pipeline, does not require the process of digging the ground and repairing the road. It is a useful construction method in terms of constructability, reliability, economy, and speed.

The non-digging pipe repair method that does not dig is a method of attaching and fixing the tube with the impregnating solution inside it to the inside of the old buried pipe. When entering the inside of the tube, the inner surface of the tube to which the impregnating liquid is applied is reversed to the surface and adhered to the inner wall of the old buried tube, so that the tube is overlaid on the inner wall of the buried tube. At this time, in order for the impregnating liquid to be evenly applied to the buried pipe and to properly adhere to the buried pipe, the impregnating liquid must be evenly applied inside the tube.

The unsaturated polyester resin used in the conventional non-digging pipe repair method has a problem in that the viscosity during impregnation is too high, so that workability is deteriorated, and molding defects occur because it is not uniformly impregnated. To solve this problem, a diluent is used, and a conventional resin composition has used a styrene monomer as a diluent. However, styrene monomer has a low flash point (31 ℃) and a low boiling point (145 ℃), so it is extremely harmful to workers as volatile organic compounds by styrene monomer volatilize during tube impregnation or curing process. City complaints (which are also irritating to the skin) have been frequently caused, and have had adverse effects such as endangering the working environment due to the risk of ignition.

As a background technology related to the present invention, there is Republic of Korea Patent No. 10-1394711 (hereinafter referred to as 'Patent Document 1').

Conventionally, it is desirable to lower the average molecular weight for a low VOC product in order to solve the problems that a large amount of styrene and other VOCs in the resin composition are present, causing a disaster to workers and the environment, and causing the release of styrene vapor to the working atmosphere. However, low molecular weight resins tend to remain sticky for a long time after application of the coating, making it difficult to use. In order to solve this problem, Patent Document 1 proposes a resin composition having a low viscosity and excellent hydrolytic stability and wind damage stability by reducing the content of styrene and using an acrylic resin.

In addition, as a background technology related to the present invention, there is Republic of Korea Patent Registration No. 10-1801290 (hereinafter referred to as 'Patent Document 2').

Conventionally, styrene (Styrene Monomer) from which VOC is emitted during the curing process has a low flash point of 31° C. in Patent Document 2, and thus always has a fire risk inherent therein. In order to solve this problem, Patent Document 2 discloses hydroxyethyl methacrylate (2-HEMA: 2-Hydroxyethyl Methacrylate) (flash point: 101° C.) and vinyl toluene monomer (VTM: Vinyl Toluene Monomer), which are a kind of acrylic derivative compound, as a diluting solvent. It has been suggested to use as

Even in Patent Documents 1 and 2 shown in the prior background art, the problem with the use of styrene, the problem of flammability and odor are still contained as it is.

That is, even if an acrylic resin is used in Patent Document 1, as described in Patent Document 1, the composition of Patent Document 1 is a composition for painting a ship (ship) and is a composition that can be used in an open working environment, and , Patent Document 1 still contains styrene in the composition, so there is inevitably a problem with the use of styrene by Patent Document 1 as well.

In addition, as described in Patent Document 2, VTM, which has to be included in order to reduce the mechanical properties and viscosity of the resin, still causes an odor problem, and the flash point of VTM is low as 54 ° C, so the conventional problems still occur. There has been a demand to further improve the working environment by using a material with better physical properties than the 2-HEMA of Patent Document 2 (flash point: 101 ° C, boiling point: 250 ° C, vapor pressure at 20 ° C: lower than 1.3) diluent .

Using a bifunctional acrylic monomer having a high flash point and boiling point and a lower vapor pressure instead of a styrene monomer, an organic compound by styrene (22 designated odor substances) ( VOC (volatile organic compounds) is not emitted, volatilization is suppressed during operation, and substances that cause unpleasant odors (eg VTM) are not used, thereby eliminating environmental pollution problems in advance and odors. An object of the present invention is to provide a resin composition that is removed to improve the working environment of the worker, facilitate the work, and increase the safety of the worker.

The resin composition of the present invention improves the working environment by mixing a diluent that reduces the volatilization of volatile organic compounds to an unsaturated alkyd prepared by using a catalyst with a saturated basic acid, an unsaturated basic acid, and a catalyst to suppress the occurrence of odor. Its purpose is to provide

The present invention has a high flash point (155 ℃), a high boiling point (310 ℃), and a lower vapor pressure at 20 ℃ (lower than 0.01) bifunctional instead of a styrene monomer that emits VOCs in a resin composition used for tube impregnation By using an acrylic monomer and not using an odor-generating substance, there is an effect of lowering VOC emission, lowering the risk of flammability, facilitating operation, and remarkably improving the working environment.

The resin composition of the present invention contains 5 to 20% by weight of maleic anhydride, 10 to 30% by weight of isophthalic acid, 5 to 20% by weight of propylene glycol, and 5 to 5% by weight of neopentyl glycol. ~20 wt%, Tripropyleneglycol diacrylate (TPGDA) 40~50 wt%, catalyst 0.002~0.02 wt%, Hydroquinone 0.002~0.02 wt%, Silica Humed 0.5~2 % by weight, and 0.1 to 0.5% by weight of a thixotropic agent anti-settling agent.

The resin composition of the present invention is summarized in a table as follows.

Components Contents (% by weight) Contents (wt%) Maleic anhydride 5-20 10 to 20 Isophthalic acid 10-30 15 to 30 Propylene glycol 5 to 20 5 to 15 Neopentyl glycol 5 to 20 5 to 10 catalyst 0.002 to 0.02 0.002 to 0.02 Tripropylene glycol diacrylate
(TPGDA: Tripropyleneglycol diacrylate) 40 to 50 45 to 50 Hydroquinone 0.002 to 0.02 0.002 to 0.02 Silica Fumed 0.5 to 2 0.5 to 1.5 thixotropic agent 0.1 to 0.5 0.1 to 0.5

The resin composition of the present invention preferably contains 10 to 20 wt% of maleic anhydride, 15 to 30 wt% of isophthalic acid, 5 to 15 wt% of propylene glycol, and neopentyl glycol (Neopentil). glycol) 5-10% by weight, tripropyleneglycol diacrylate (TPGDA) 45-50% by weight, catalyst 0.002 to 0.02% by weight, hydroquinone 0.002 to 0.02% by weight, silica fume (Silica Humed) 0.5 to 1.5% by weight, and 0.1 to 0.5% by weight of a thixotropic agent anti-settling agent.

Looking specifically at the resin composition of the present invention, the resin composition of the present invention is obtained by mixing a diluent that reduces the volatilization of volatile organic compounds to an unsaturated alkyd prepared by using a catalyst with a saturated basic acid, an unsaturated basic acid, and a polyhydric alcohol. It is a resin composition which suppresses generation|occurrence|production. The resin composition of the present invention does not contain designated odor substances (22 types).

Maleic anhydride, constituting the resin composition of the present invention, is an unsaturated basic acid and imparts unsaturation due to double bonds in the structure to improve curing properties and increase the viscosity of the unsaturated polyester resin, and radical reaction sites for crosslinking used to provide In general, the amount of maleic anhydride is 5 to 20% by weight, preferably 10 to 20% by weight.

In the present invention, isophthalic acid (Isophthalicacid) is used to improve chemical resistance, heat resistance, weather resistance and mechanical properties of the unsaturated polyester resin. In general, the amount of isophthalic acid (Isophthalic acid) is 10 to 30% by weight, preferably 15 to 30% by weight.

In the resin composition of the present invention, propylene glycol (Propylene Glycol) is used to improve physical properties by imparting rigidity to the unsaturated polyester resin. The amount of propylene glycol is 5 to 20% by weight, preferably 5 to 15% by weight.

Neopentil glycol (Neopentil Glycol) is used to improve water resistance, chemical resistance, and weather resistance in the unsaturated polyester resin. The amount of neopentil glycol is 5 to 20 wt%, preferably 5 to 10 wt% to be.

The catalyst is used to accelerate the ester reaction rate between isophthalic acid and glycols with low reactivity. As a catalyst, Hydrated Monobutyltin Oxide, etc. can be used. The amount of catalyst is 0.002 to 0.02% by weight.

Tripropylene glycol diacrylate (TPGDA) of the present invention is a bifunctional acrylic monomer that can be polymerized by free radicals. It is widely used in U.V & E.B curing paints, inks and adhesives as a particularly useful reactive diluent when water resistance and low viscosity are required. Tripropylene glycol diacrylate is used as a diluting solvent to reduce volatilization of volatile organic compounds. In general, the amount of tripropylene glycol diacrylate (Tripropyleneglycol diacrylate, TPGDA) is 40 to 50% by weight, preferably 45 to 50% by weight.

Hydroquinone is used as a polymerization inhibitor (stabilizer) and curing retardant for unsaturated polyester resins. The amount of hydroquinone (Hydroquinone) is 0.002 to 0.02% by weight.

Silica Fumed is used as a thixotropic agent to prevent the flow of unsaturated polyester resin due to gravity in a vertical plane. The amount of silica fume (Silica Humed) is 0.5 to 2% by weight, preferably 0.5 to 1.5% by weight.

A thixotropic agent anti-settling agent is used to prevent sedimentation of silica fume, a thixotropic agent.

1. Preparation of the resin of the present invention

The composition and manufacturing process of an embodiment of the resin composition of the present invention are as follows.

Components Contents (wt%) Maleic anhydride 15 Isophthalic acid 23 Propylene glycol 10 Neopentyl glycol 5 catalyst 0.004 Tripropylene glycol diacrylate
(TPGDA: Tripropyleneglycol diacrylate) 46 Hydroquinone 0.006 Silica Fumed 0.8 thixotropic agent 0.2

1) First reaction step

In a reactor equipped with a stirrer, a calorimeter, a water separation column equipped with a reflux condenser and a nitrogen inlet, 10% by weight of propylene glycol, 5% by weight of neopentil glycol, 23% by weight of isophthalic acid, After adding 0.004% by weight of the catalyst, the temperature of the reactor is raised to 215 ° C. When the temperature rise is completed, the temperature is maintained.

The first reaction is terminated when the acid value of the compositions added to the reactor is measured while maintaining the temperature and the acid value is 20 or less.

2) Secondary reaction step

After the completion of the first reaction, the temperature of the reactor is maintained at 160 ℃, 15% by weight of maleic anhydride is added, the temperature of the reactor is raised to 205 ℃, and when the temperature increase of the reactor is completed, it is required in this state The secondary reaction is terminated after maintaining until reaching the acid values and viscosity values.

The acid value, which is the criterion for terminating the reaction of the compositions in the reactor, is 35 or less, and the viscosity is in the range of Q to S based on Gardner viscosity.

The viscosity of the resin is measured through 'Alkyd Resin: Diluting Solvent', and it is checked every hour by sampling with Alkyd Resin: Diluting Solvent = 2:1 under the condition to realize the physical properties of the finished product.

3) tertiary reaction step

After the secondary reaction was completed, the temperature of the reactor was cooled to 160 °C, and then the reactants of the reactor were transferred to a dilution tank in which 46 wt% of tripropyleneglycol diacrylate (TPGDA) and 0.006 wt% of hydroquinone were added. Agitate and dilute.

4) quaternary reaction step

After the third reaction step, 0.8 wt% of silica fume and 0.2 wt% of a thixotropic agent are added to the resin, and the silica fume is sufficiently dispersed while stirring at high speed.

After dispersing the silica fume, the process of completing the resin manufacturing is completed by adjusting it to meet the required physical properties of the finished product.

2. Comparative Examples and Examples

An experiment was conducted to compare the physical properties of the example using tripropylene glycol diacrylate (TPGDA) of the resin composition of the present invention and the comparative example using a styrene monomer instead. That is, Examples 1 and 2 of the resin composition of the present invention use tripropylene glycol diacrylate (TPGDA), but Comparative Examples 1 and 2 in contrast to this use a conventional styrene monomer instead of TPGDA, and Comparative Example 1 When the remaining components of , 2 were used almost similarly to Examples 1 and 2, their own experiments were conducted to compare their respective physical properties, and the results are as follows.

Item unit Comparative Example 1 Comparative Example 2 Example 1 Example 2 maleic anhydride weight% 18 17 17 15 isophthalic acid weight% 27 26 25 23 propylene glycol weight% 12 11 11 10 neopentyl glycol weight% 6 6 6 5 catalyst weight% 0.004 0.004 0.004 0.004 hydroquinone weight% 0.006 0.006 0.006 0.006 silica fume weight% 0.8 0.8 0.8 0.8 thixotropic agent weight% 0.2 0.2 0.2 0.2 styrene monomer weight% 36 39 - - TPGDA weight% - - 40 46 Viscosity at 25 ℃ poise 25 14 37 30 non-volatile matter % 64 61 - - Gelation time (GT) min 7.6 8.0 5.3 6.3 Minimum curing time (MCT) min 9.6 10.8 6.3 7.2 Peak Heating Time (MET) ℃ 222 225 195 185

Here, GT is an abbreviation for Gel Time, MCT is an abbreviation for Minimum Cure Time, and MET is an abbreviation for Maximum Exothermic Temperature. Examples 1 and 2 of the present invention have a faster gelation time and cure as compared to Comparative Examples 1 and 2 You can see that time goes by quickly. It can be seen that the performance is improved.

As in Examples 1 and 2, the resin composition of the present invention may have different viscosity characteristics depending on the weight ratio of the resin composition, and a low viscosity value for easy operation may be obtained. Furthermore, by varying the weight ratio of the resin composition of the present invention, the 'standard for in-situ curing non-excavating repair tubes for sewage and drainage pipes using thermosetting resins (KS M 3550-9, Table 7 Characteristics of unsaturated polyester resins)' A satisfactory low viscosity characteristic can be obtained. The following is a test result report from an authorized institution for Comparative Example 1 (PT-203T) and another example (PT-500T) of the resin composition of the present invention, which can be compared with the quality standards in the above standards

Comparison of physical properties of resin compositions (test results commissioned by accredited institutions) Test Items unit Quality standards PT-203T PT-500T test crime prevention density Kg/m3 1.1~1.2 1.121 1.120 See 5.1 of KS M 3331 acid value KOH mg/g 24 or less 15.5 13.8 See 5.3 of KS M 3331 hydroxyl value KOH mg/g 30 or less 24.5 22.3 See 5.4 of KS M 3331 Viscosity poise 20 to 30 25.10 25.50 See 5.5 of KS M 3331 80℃ high temperature curing characteristics (gelation time) s 300 to 600 436 590 See 5.7 of KS M 3331 volatile matter % 35+* 39.0 - See 5.11 of KS M 3331

* A quality standard of 35 or higher for volatile matter (in the case of using styrene) means an acceptable standard, a high value means more volatile content, and a low value means less volatile content.

According to the above experimental results, the Example (PT-500T) of the resin composition of the present invention requested by an authorized agency could obtain a viscosity within the viscosity range of the quality standard.

VOC emission was compared using the resin composition of Comparative Example 1 using a styrene monomer and the resin composition of Example 1 using TPGDA of the present invention.

VOC Emission Comparison Test Items unit Comparative Example 1 Example 1 VOC content upon curing* g/L 241.9 18.1

*: For curing conditions, the resin and the curing agent were mixed and then maintained at 80° C. for 2 hours. Here, the test method is the result obtained by using the certified test method (KS M ISO 11890-1: 2007) without using the own test method.

Looking at [Table 5], when the composition of Comparative Example using a styrene monomer is cured, a volatile organic compound is significantly generated, but when the composition of Example 1 using the tripropylene glycol diacrylate of the present invention is cured, the amount of the volatile organic compound is It can be seen that the incidence decreases rapidly.

Comparison of thinner properties (see MSDS)* Item unit SM EGDMA 2-HEMA VTM TPGDA smell strong ester ester unpleasant unique, weak flash point
(Flash point) ℃ 31 101 101 54 155 Boiling point at 1013hPa ℃ 145 240 250 168 310 Vapor pressure at 20℃ hPa 6.7 <1 1.3 2.0 <0.01

* Depending on the MSDS (Material Safety Data Sheet) provided by each company that sells each substance, the properties of the diluent may be slightly different.

SM: Styrene Monomer

EGDMA: Ethylene Glycol Dimethacrylate

2-HEMA: 2-Hydroxyethyl Methacrylate

TPGDA: Tripropyleneglycol diacrylate

Flash point: When a sample is heated under certain conditions, the amount of vapor generated is sufficient to make a combustible gas mixture with air on the surface of the sample. says the temperature of

Boiling point (Boiling point): The temperature at which a liquid begins to boil as bubbles are generated on the surface and inside. It is the temperature at which the state of matter changes from liquid to gas as well as evaporation from the surface of the liquid.

Vapor pressure: The pressure exhibited by the gas phase of a substance when the condensed phase and the gas phase of the substance are in thermodynamic equilibrium in a closed system.

In [Table 6] above, TPGDA has a higher flash point and boiling point than SM or VTM and a lower vapor pressure, so it can improve the working environment by reducing/suppressing volatilization of volatile organic compounds (VOC) during tube impregnation or curing process, It is possible to prevent civil complaints that occur during work in residential areas in advance, and there is an effect of improving the unpleasant odor of VTM, which further improves the working environment.

Claims (5)

Maleic anhydride 5-20 wt %, Isophthalic acid 10-30 wt %, Propylene glycol 5-20 wt %, Neopentil glycol 5-20 wt %, Tri Tripropyleneglycol diacrylate (TPGDA) 46-50 wt%, catalyst 0.002-0.02 wt%, Hydroquinone 0.002-0.009 wt%, Silica Humed 0.5-2 wt%, and a thixotropic agent A resin composition for repairing a low-odor non-excavated pipeline, comprising 0.1 to 0.5% by weight of an anti-settling agent. delete delete delete delete