Solvent-free yellowing-resistant polyurethane single-component glue and preparation method thereof

Abstract

The invention discloses solvent-free yellowing-resistant polyurethane single-component glue and a preparation method thereof, and belongs to the technical field of high polymer materials. The glue is prepared from the following raw materials in parts by weight: 60 to 70 parts of PTMG2000, 3 to 4 parts of TMP, 30 to 40 parts of a plasticizer, 30 to 40 parts of IPDI, 20 to 30 parts of HMDI, 0.3 to 0.5 part of an antioxidant, 0.4 to 0.6 part of an ultraviolet absorbent, 0.3 to 0.5 part of a light stabilizer and 0.003 to 0.005 part of a catalyst. The preparation method comprises the steps of dehydration, prepolymerization, catalytic chain extension, crosslinking and final polymerization reaction, and the synthesis process is controlled through staged temperature control (115 DEG C dehydration and 80 DEG C polymerization) and NCO endpoint detection. According to the invention, aliphatic isocyanate (IPDI / HMDI) is used for replacing a traditional aromatic raw material, and an anti-aging aid is combined, so that the problem of yellowing of the glue (delta E is less than 1.5 after ultraviolet aging for 500 hours) is thoroughly solved, and meanwhile, solvent-free addition (VOCs is less than 10g / L) is realized, the bonding strength is more than or equal to 2.5 MPa, and the damp-heat aging-resistant peel strength is more than or equal to 4.5 N / mm, and the standards of GB / T 14833-2020 and the like are met. The product is excellent in environmental protection property, weather resistance and construction performance, and is suitable for long-acting bonding of EPDM particle sports fields.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and specifically to a solvent-free yellowing-resistant one-component polyurethane glue and a manufacturing method thereof. Background Art

[0002] With the improvement of the national awareness of health campaigns, the aesthetics, durability and environmental friendliness of sports venues have become the core issues of concern in the industry. At present, the following technical defects need to be urgently solved in the application of one-component polyurethane glue on the market:

[0003] 1. Poor environmental performance

[0004] Traditional glues generally add organic solvents such as benzene and ketones to reduce viscosity, resulting in high content of volatile organic compounds (VOCs), generating pungent odors during construction, and causing potential harm to the environment and human health in the long term, making it difficult to meet the requirements of green environmental protection standards.

[0005] 2. Severe and irreversible yellowing

[0006] Glues made from aromatic polyisocyanates (such as TDI and MDI) are prone to form quinoid structures under the action of ultraviolet rays or thermal oxidation, leading to rapid yellowing (experiments show that ordinary glues turn yellow after several hours of sunlight exposure, and the color significantly deepens to dark yellow after 2 months of outdoor exposure). Yellowing not only causes uneven and dull colors on the surface of sports venues (as shown in Figures 1 - 3 ), but also is accompanied by the aging and degradation of the glue layer, resulting in a decrease in adhesion force of more than 50%, seriously affecting the aesthetics and structural safety of the venue.

[0007] 3. Insufficient weather resistance and anti-aging performance

[0008] Existing glues are prone to oxidative degradation in harsh environments such as high humidity and high ultraviolet rays, and the bonding layer is prone to delamination and particle shedding, unable to meet the long-term use requirements of outdoor sports venues. For example, after 500 hours of ultraviolet aging, the adhesion decay rate of ordinary glues is as high as 40%, while that of yellowing-resistant glues only decreases by 5%-8%.

[0009] 4. Unqualified comprehensive performance

[0010] Most products are difficult to balance key indicators such as viscosity regulation, curing speed, and chemical resistance, resulting in low construction efficiency, poor site flatness, and inability to pass the new national standard (GB / T 14833-2020) and the strict environmental protection detection standards formulated in Shanghai, Shenzhen and other places, restricting their application in high-quality sports venues.

[0011] The above defects indicate that developing a solvent-free, yellowing-resistant and excellent comprehensive performance one-component polyurethane glue has become an urgent technical problem to be solved in the field of sports venue materials. Summary of the Invention

[0012] The technical problems solved by the present invention are poor environmental protection performance, serious and irreversible yellowing phenomenon, insufficient weather resistance and anti-aging performance, and unqualified comprehensive performance.

[0013] The technical solution adopted by the present invention is as follows: a solvent-free yellowing-resistant one-component polyurethane glue is polymerized from the following raw materials in parts by weight:

[0014] 60-70 parts of PTMG2000, 3-4 parts of TMP, 30-40 parts of plasticizer, 30-40 parts of IPDI, 20-30 parts of HMDI, 0.3-0.5 part of antioxidant, 0.4-0.6 part of ultraviolet absorber, 0.3-0.5 part of light stabilizer, 0.003-0.005 part of catalyst.

[0015] As a further scheme of the present invention: it is polymerized from the following raw materials by weight:

[0016] PTMG2000: 65 kg, TMP: 3.5 kg, plasticizer: 35 kg, IPDI: 35 kg, HMDI: 25 kg, antioxidant: 0.4 kg, ultraviolet absorber: 0.5 kg, light stabilizer: 0.4 kg, catalyst: 0.004 kg.

[0017] As a further scheme of the present invention: it is polymerized from the following raw materials by weight:

[0018] PTMG2000: 65 kg, TMP: 3.5 kg, plasticizer: 35 kg, IPDI: 35 kg, HMDI: 25 kg, antioxidant: 0.4 kg, ultraviolet absorber: 0.5 kg, light stabilizer: 0.4 kg, catalyst: 0.004 kg.

[0019] As a further scheme of the present invention: it is polymerized from the following raw materials by weight:

[0020] PTMG2000: 70 kg, TMP: 4 kg, plasticizer: 40 kg, IPDI: 40 kg, HMDI: 30 kg, antioxidant: 0.5 kg, ultraviolet absorber: 0.6 kg, light stabilizer: 0.5 kg, catalyst: 0.005 kg.

[0021] A method for preparing a solvent-free yellowing-resistant one-component polyurethane glue includes the following steps:

[0022] (1) Add the metered PTMG2000, plasticizer, antioxidant, ultraviolet absorber, and light stabilizer into the reaction kettle, stir and heat up to 115 °C, and dehydrate for 120 minutes under the condition that the vacuum degree is not lower than -0.08 MPa;

[0023] (2) After dehydration is completed, cool down to 80°C, add the metered IPDI, and keep reacting at 80°C for 30 minutes;

[0024] (3) Add the metered catalyst, continue stirring and reacting for 30 minutes, and take samples to measure the NCO content until the reaction reaches the end point;

[0025] (4) Add the metered TMP, react for 10 minutes, and take samples to measure the NCO content until the reaction reaches the end point;

[0026] (5) Add the metered HMDI, keep reacting at 80°C for 30 minutes, and package and discharge the material after reaching the end point.

[0027] As a further solution of the present invention: in the steps (3) and (4), the end point of the NCO content is determined by chemical titration or infrared spectroscopy.

[0028] The beneficial effects of the present invention:

[0029] 1. Green and environmentally friendly, without solvent addition

[0030] In the glue formula, organic solvents such as benzene and ketone are completely abandoned, and the viscosity is reduced only through the synergistic effect of PTMG2000 and plasticizer (the plasticizer accounts for 30-40 parts in Examples 1-3), realizing a construction viscosity ≤ 3000 mPa·s (25°C) to meet the spraying / scraping requirements. The product passes the detection of GB 30982-2014 "Limit of Hazardous Substances in Building Adhesives", the VOCs content < 10 g / L, has no pungent smell, and meets the new national standard and local environmental protection standards.

[0031] 2. Completely prevent yellowing and maintain beauty permanently

[0032] Aliphatic polyisocyanate IPDI and HMDI are compounded (IPDI 30-40 parts, HMDI 20-30 parts) to avoid the formation of quinone structures. Combined with the dual protection of ultraviolet absorber (0.4-0.6 parts) and light stabilizer (0.3-0.5 parts), the adhesive film remains transparent and colorless after being exposed to the sun outdoors for 2 months. After 500 hours of ultraviolet aging, the yellowing index ΔE < 1.5 (ΔE > 15 for ordinary glue), and the adhesion retention rate ≥ 95%.

[0033] 3. Excellent weather resistance and anti-aging performance

[0034] The antioxidant (0.3-0.5 parts) is used to inhibit the thermal oxidation reaction. Combined with the stable chemical structure of aliphatic isocyanate, after the adhesive layer is aged for 1000 hours under high temperature and high humidity (85°C / 85%RH) conditions, the tensile strength retention rate ≥ 90%, and the particle bonding and peeling strength ≥ 4.5 N / mm (≤ 2.0 N / mm for ordinary glue), effectively avoiding delamination and particle dropping phenomena.

[0035] 4. Excellent comprehensive performance, meeting high-standard requirements

[0036] Fast curing: The surface drying time of the glue is ≤ 30 min (25 °C), and the through drying time is ≤ 24 h, improving the construction efficiency;

[0037] High bonding strength: After bonding with EPDM particles, the tensile strength is ≥ 2.5 MPa (GB / T 528 - 2009), far exceeding the national standard requirement of 1.8 MPa;

[0038] Chemical resistance: Resistant to acid (5% H 2 SO 4 ), and after being soaked in alkali (5% NaOH) for 7 days, there is no swelling or cracking, suitable for complex environments;

[0039] Standard compliance: Passed the local standard tests such as Shanghai DB31 / T 669 - 2020 and Shenzhen SZJG 48 - 2018, meeting the requirements for the construction of high-end sports venues.

[0040] 5. Stable process, feasible for industrial production

[0041] The staged temperature-controlled polymerization process (such as dehydration at 115 °C and reaction at 80 °C) combined with NCO endpoint detection ensures batch stability (the NCO content error in Examples 1 - 3 is ≤ 0.2%), and the product storage period is ≥ 12 months with no gel risk. Description of the drawings

[0042] Figure 1 It is a diagram of the ordinary glue and the yellowing-resistant glue film (outdoor for 2 months) of a solvent-free yellowing-resistant one-component polyurethane glue and its manufacturing method according to the present invention.

[0043] Figure 2 It is a diagram of the ordinary glue and the yellowing-resistant glue film (ultraviolet aging for 500 h) of a solvent-free yellowing-resistant one-component polyurethane glue and its manufacturing method according to the present invention.

[0044] Figure 3 It is a comparison diagram of the ordinary glue and the yellowing-resistant glue particle film of a solvent-free yellowing-resistant one-component polyurethane glue and its manufacturing method according to the present invention. Detailed implementation manners

[0045] The present invention will be further described below.

[0046] Example 1

[0047] Raw material ratio:

[0048] PTMG2000: 65 kg, TMP: 3.5 kg, plasticizer: 35 kg, IPDI: 35 kg, HMDI: 25 kg, antioxidant: 0.4 kg, UV absorber: 0.5 kg, light stabilizer: 0.4 kg, catalyst: 0.004 kg

[0049] Preparation steps:

[0050] 1. Dehydration treatment: Add 60 Kg of PTMG2000, 30 Kg of plasticizer, 0.3 Kg of antioxidant, 0.4 Kg of UV absorber, and 0.3 Kg of light stabilizer into the reaction kettle, start stirring and heat up to 115 °C. At the same time, start the vacuum pump to keep the vacuum degree of the reaction kettle above -0.08 MPa and continuously dehydrate for 120 minutes.

[0051] 2. Cooling: After the dehydration is completed, cool down the reaction system to 80 °C.

[0052] 3. Prepolymerization reaction: Add 30 Kg of IPDI into the reaction kettle, keep the temperature at 80 °C and react for 30 minutes.

[0053] 4. Catalytic reaction: Slowly add 0.003 Kg of catalyst under stirring and continue to react for 30 minutes. Take samples to detect the NCO content until the reaction reaches the end point.

[0054] 5. Crosslinking reaction: Add 3 Kg of TMP and react for 10 minutes. Take samples to detect the NCO content until the end point.

[0055] 6. Final polymerization reaction: Add 20 Kg of HMDI, keep the temperature at 80 °C and react for 30 minutes. After detecting that the NCO content meets the standard, discharge and package.

[0056] Example 2

[0057] Raw material ratio:

[0058] PTMG2000: 65 kg, TMP: 3.5 kg, plasticizer: 35 kg, IPDI: 35 kg, HMDI: 25 kg, antioxidant: 0.4 kg, UV absorber: 0.5 kg, light stabilizer: 0.4 kg, catalyst: 0.004 kg

[0059] Preparation steps:

[0060] 1. Dehydration treatment: Add 65 Kg of PTMG2000, 35 Kg of plasticizer, 0.4 Kg of antioxidant, 0.5 Kg of UV absorber, and 0.4 Kg of light stabilizer into the reaction kettle, turn on the stirring, raise the temperature to 115 °C, and turn on the vacuum to keep the vacuum degree of the reaction kettle above -0.08 MPa and continuously dehydrate for 120 min.

[0061] 2. Cooling: After the dehydration is completed, cool down to 80 °C.

[0062] 3. Prepolymerization reaction: Charge 35 Kg of IPDI into the reaction kettle, maintain at 80 °C, and react for 30 min.

[0063] 4. Catalytic reaction: Slowly add 0.004 Kg of catalyst into the reaction kettle under stirring, continue to react for 30 min, sample and measure NCO, and wait until the reaction reaches the end point.

[0064] 5. Crosslinking reaction: Add 3.5 Kg of TMP into the reaction kettle, react for 10 min; sample and measure NCO, and wait until the reaction reaches the end point.

[0065] 6. Final polymerization reaction: Charge 25 Kg of HMDI into the reaction kettle, maintain at 80 °C, react for 30 min, and package and discharge after reaching the end point.

[0066] Example 3

[0067] Raw material ratio:

[0068] PTMG2000: 70 kg, TMP: 4 kg, plasticizer: 40 kg, IPDI: 40 kg, HMDI: 30 kg, antioxidant: 0.5 kg, ultraviolet absorber: 0.6 kg, light stabilizer: 0.5 kg, catalyst: 0.005 kg

[0069] Preparation steps:

[0070] 1. Dehydration treatment: Add 70 Kg of PTMG2000, 40 Kg of plasticizer, 0.5 Kg of antioxidant, 0.6 Kg of ultraviolet absorber, and 0.5 Kg of light stabilizer into the reaction kettle, turn on the stirring, raise the temperature to 115 °C, and turn on the vacuum to maintain the vacuum degree of the reaction kettle above -0.08 MPa, and continuously dehydrate for 120 min.

[0071] 2. Cooling: After dehydration is completed, cool down to 80 °C.

[0072] 3. Prepolymerization reaction: Charge 40 Kg of IPDI into the reaction kettle, maintain at 80 °C, and react for 30 min.

[0073] 4. Catalytic reaction: Slowly add 0.005 Kg of catalyst into the reaction kettle under stirring, continue to react for 30 min, sample and measure NCO, and wait until the reaction reaches the end point.

[0074] 5. Crosslinking reaction: Add 4 Kg of TMP into the reaction kettle, react for 10 min; sample and measure NCO, and wait until the reaction reaches the end point.

[0075] 6. Final polymerization reaction: Charge 40 Kg of HMDI into the reaction kettle, maintain at 80 °C, react for 30 min, and package and discharge after reaching the end point.

[0076] Verification of implementation effect

[0077] The performance of the adhesives obtained in Examples 1-3 was tested, and the results are as follows:

[0078] Test items Example 1 Example 2 Example 3 National standard requirements Viscosity (25°C, mPa·s) 2850 2650 2500 ≤3500 Surface drying time (min) 28 25 22 ≤60 Tensile strength (MPa) 2.6 2.8 3.0 ≥1.8 ΔE after 500h of UV aging 1.3 1.1 0.9 -

[0079] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A solvent-free yellowing-resistant polyurethane one-component glue, characterized in that: It is polymerized by the following raw materials in parts by weight: PTMG2000 60-70 parts, TMP 3-4 parts, plasticizer 30-40 parts, IPDI 30-40 parts, HMDI 20-30 parts, antioxidant 0.3-0.5 parts, UV absorber 0.4-0.6 parts, light stabilizer 0.3-0.5 parts, catalyst 0.003-0.005 parts.

2. The solvent-free yellowing-resistant polyurethane one-component glue according to claim 1, characterized in that: It is polymerized by the following weights: PTMG2000: 65kg, TMP: 3.5kg, plasticizer: 35kg, IPDI: 35kg, HMDI: 25kg, antioxidant: 0.4kg, UV absorber: 0.5kg, light stabilizer: 0.4kg, catalyst: 0.004kg.

3. The solvent-free yellowing-resistant polyurethane one-component glue according to claim 1, characterized in that: It is polymerized by the following weights: PTMG2000: 65kg, TMP: 3.5kg, plasticizer: 35kg, IPDI: 35kg, HMDI: 25kg, antioxidant: 0.4kg, UV absorber: 0.5kg, light stabilizer: 0.4kg, catalyst: 0.004kg.

4. The solvent-free yellowing-resistant polyurethane one-component glue according to claim 1, characterized in that: It is polymerized by the following weights: PTMG2000: 70kg, TMP: 4kg, plasticizer: 40kg, IPDI: 40kg, HMDI: 30kg, antioxidant: 0.5kg, UV absorber: 0.6kg, light stabilizer: 0.5kg, catalyst: 0.005kg.

5. A method for preparing a solvent-free yellowing-resistant polyurethane one-component glue, characterized in that: The following steps are involved: (1) Add the measured PTMG2000, plasticizer, antioxidant, ultraviolet absorber and light stabilizer into a reaction kettle, stir and heat to 115° C., and dehydrate for 120 minutes under a vacuum degree of not less than -0.08 MPa; (2) After dehydration is completed, the temperature is lowered to 80°C, and the measured IPDI is added, and the temperature is maintained at 80°C for 30 minutes; (3) Add the measured catalyst, continue stirring the reaction for 30 minutes, and take samples to measure the NCO content until the reaction reaches the endpoint; (4) adding the measured amount of TMP, reacting for 10 minutes, and taking samples to measure the NCO content until the reaction reaches the endpoint; (5) Add the measured amount of HMDI, maintain the reaction at 80°C for 30 minutes, and package and discharge the material after reaching the endpoint.

6. The method for preparing a solvent-free yellowing-resistant polyurethane one-component glue according to claim 5, characterized in that: In the steps (3) and (4), the endpoint of the NCO content is determined by chemical titration or infrared spectroscopy.

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