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1、 Storage stage issues

1. After adding alcohol ester 12, the coating flocculates, clumps, and breaks down

Phenomenon: After dripping, lumps and clumps appear, which cannot be dispersed by stirring

1. The stock solution is directly and rapidly flushed into the lotion, and the concentration of local additives is too high, causing the emulsion particles to swell violently;

2. Acetate acrylic lotion system has weak resistance to high boiling point esters;

3. The pH of the system is low, and the stability of the lotion is reduced by adding solvent shock.

Solution

1. It is strictly prohibited to directly add pure alcohol ester 12; Dilute with propylene glycol/ethylene glycol at a ratio of 1:0.5-1 first;

2. Slowly add dropwise under low-speed stirring;

3. Feeding sequence: dispersion filler → lotion → diluted alcohol ester 12, do not add additives first and then add lotion;

4. Reduce the single addition rate of vinegar propylene system appropriately and maintain the pH of the system at 8.0-9.0.

2. Oil floating on the surface of the paint and oil droplets appearing on the upper layer after standing still

Phenomenon: A layer of transparent oil phase is left on the surface of the bucket, which temporarily disappears after stirring, and rises again after prolonged storage due to the extremely low solubility of alcohol ester 12 in water; The addition amount exceeds the carrying capacity of lotion particles; Lack of auxiliary solvents (antifreeze alcohol) for medium transition.

Solution

1. Do not add too much, find the minimum amount required for critical film formation;

2. The formula retains an appropriate amount of propylene glycol/ethylene glycol to help disperse the additives;

3. Mix thoroughly before discharging; Stir the product thoroughly before long-term use.

2、 Visual drawbacks of construction and drying

1. The paint film dries slowly, becomes soft in the early stage, is prone to sticking dust, and has short-term rebound

Phenomenon: After several days of construction, it feels sticky to the touch and easily absorbs dust outdoors. The high gloss is caused by the slow evaporation rate of alcohol ester 12; Excessive addition; Poor ventilation, low temperature and high humidity environment make it difficult for additives to diffuse and escape outward.

Key difference: Alcohol ester 12 can gradually evaporate in the later stage and gradually harden after long-term storage, unlike permanent plasticizers. Solution

1. Reduce the amount of additives and do not rely on excessive additives to improve low-temperature construction;

2. Need to accelerate the increase in hardness: a small amount of compound medium volatile solvents such as DPnB (5% to 15% ratio to replace part of C12);

3. It is recommended to ensure good ventilation after construction;

4. Do not increase the dosage of C12 without limit for high Tg wood paint.

2. Slight whitening, fogging, and loss of gloss of the paint film during high humidity and low temperature construction

Phenomenon: When applied in humid weather, the surface becomes hazy and white, and even after a long time of drying, there is still no light. After ventilation and temperature rise, there is a slight improvement due to slow drying speed, and water vapor in the air is trapped inside the coating; Water and additives migrate to the interface to form micro lotion. Alcohol ester 12 itself is not easy to absorb water, and its whitening is mostly due to environmental factors, not hydrolysis of additives

Solution

1. Avoid construction with humidity greater than 85% and temperature lower than the MFFT system;

2. Mix with a small amount of antifreeze solvent to increase the opening time and reduce the risk of water vapor condensation;

3. Properly control the thickness of the wet film and do not apply it excessively.

3. Pinholes, bubbles, volcanic craters

Cause: The feeding speed is too fast, and a large amount of air is sucked in by vigorous stirring; Alcohol ester 12 changes the local surface tension, causing an imbalance in the matching of defoamers. Solution

1. Reduce the stirring speed during the addition stage to minimize air entrapment;

2. It can be added in small quantities in batches, do not throw it all at once;

3. Choose defoamers that are compatible with the solvent system, and add a small amount of foam adjusting defoamers if necessary.

3、 Issues related to film-forming performance

1. The low-temperature environment still causes powdering and powder loss

Many people mistakenly believe that adding alcohol ester 12 will definitely result in low-temperature film formation

2. Insufficient amount added to reduce the required amount of MFFT;

3. The Tg of lotion is too high, and the capacity of pure C12 is limited;

The actual construction temperature is much lower than the MFFT of the coating.

Solution

1. Conduct gradient addition test and measure the minimum film-forming temperature MFFT of the coating;

2. High Tg systems can be combined with a small amount of PPH to improve plasticization efficiency;

3. Prioritize ensuring the construction temperature and cannot rely indefinitely on film-forming additives to make up for it.

2. The paint film’s resistance to scrubbing and water resistance is not as expected

cause

Excessive addition of alcohol ester 12 results in a large amount of additives remaining inside the paint film for a long time, forming hydrophilic microchannels;

2. If the drying and curing time is insufficient, conduct a water resistance test;

Comparison tip: Under the same dosage, the water resistance of alcohol ester 12 is much better than that of benzyl alcohol and EB ethylene glycol butyl ether.

Solution

1. Strictly control the upper limit consumption, and the internal wall is generally not more than 10% (based on the solid content of lotion);

2. The water resistance test must be fully cured (at room temperature for more than 7 days);

3. For exterior wall systems, it is advisable to avoid using low-cost additives to replace alcohol esters in large quantities.

4、 Odor, Environmental Protection, and Storage Stability

1. The finished paint has a strong odor and does not meet the requirements for clean odor

Ethanol ester 12 itself has a characteristic ester odor; High content of inferior by-products; After thick coating, the auxiliary agent slowly and continuously evaporates.

Solution

1. Replace alcohol ester 12 with alcohol ester 16 (OE300 low odor film-forming aid);

2. Avoid compounding with benzyl alcohol, as the combination of the two significantly exacerbates the odor;

3. Optimize the formula and reduce the overall amount of organic solvents.

2. Gloss changes and performance fluctuations after long-term thermal storage

Due to uneven dispersion of the additive, alcohol ester 12 continues to penetrate into the latex particles during high-temperature storage, altering the melting behavior of the particles.

Solution

1. Standardized feeding process to ensure uniform dispersion;

2. Conduct a 50 ℃ thermal storage stability test on the finished product;

3. Stir the plate thoroughly before use after thermal storage.

5、 Unique issues with outdoor exterior wall systems

Late stage loss of gloss and deterioration of weather resistance of paint film

Alcohol ester 12 itself has excellent resistance to hydrolysis and weather, and the problem is basically not caused by the additives themselves. Common causes include:

1. Use inferior alcohol ester 12, which contains unsaturated impurities and small molecule by-products;

2. Coordinated aging with benzyl alcohol and inferior ether additives;

Solution: The exterior wall formula should be as single as possible or only composed of alcohol ester 12 and a small amount of DPnB, and a large amount of benzyl alcohol is prohibited.

6、 Practical points for avoiding pitfalls (directly applicable in the workshop)

1. Best feeding method: alcohol ester 12+propylene glycol pre mixed dilution, slowly added dropwise at low speed;

2. Prioritize conducting MFFT gradient experiments, find the lowest effective addition amount, and reject excessive addition;

3. Acetate acrylic lotion should be added at one time with high concentration with caution;

4. Low odor required: C12 ↔ Compound of alcohol ester 16;

5. Need to accelerate drying and reduce stickiness: a small amount of DPnB compound;

6. External wall system: mainly composed of alcohol ester 12, with minimal addition of benzyl alcohol.