Tertiary amine polyurethane catalysts and their use

Abstract

The present application relates to a kind of tertiary amine polyurethane catalyst and its application, in tertiary amine polyurethane catalyst, by introducing the structure of double ether bond that is symmetrically distributed in molecule, and set specific end group that can form hydrogen bond effect, while keeping good catalytic activity, effectively reduce the volatility and migration of catalyst, so as to realize the technical effect of low odor and low emission.

Description

Technical Field

[0001] This invention belongs to the field of catalysts for polyurethane materials, and specifically relates to a tertiary amine polyurethane catalyst and its application. Background Technology

[0002] Polyurethane foam materials are widely used in automotive interiors, furniture, building insulation, and electronic packaging due to their excellent elasticity, cushioning properties, and processability. During the polyurethane foaming process, tertiary amine catalysts are typically added to promote the reaction between isocyanates and polyols or water, thereby controlling the balance between the initiation and gelation reactions.

[0003] The tertiary amine polyurethane catalysts commonly used in the prior art are mostly low molecular weight structures. Although these catalysts have high catalytic activity, they generally have problems such as high volatility, obvious odor, and easy migration in foam systems. This leads to the release of amines during the post-curing and use of the product, resulting in unpleasant odors and volatile organic compound emissions, making it difficult to meet the application scenarios with high requirements for low odor and low emissions.

[0004] To address the aforementioned issues, several patented technologies have proposed reducing the volatility of tertiary amines by increasing their molecular weight. However, such technologies often result in decreased catalytic activity or poor compatibility in polyurethane systems due to increased molecular structural rigidity or polarity imbalance.

[0005] In addition, some patented technologies propose introducing hydroxyl groups or single ether bonds into tertiary amine molecules to improve their solubility and compatibility in polyurethane systems. However, the polar interaction sites introduced by such technologies are limited, and their inhibitory effect on catalyst migration is insufficient, making it difficult to significantly reduce the release of amines in the later stages.

[0006] Some patented technologies attempt to reduce migration by introducing amino or urea bonds into catalyst molecules and utilizing hydrogen bonding. However, these technologies typically lack a systematic design for the overall molecular structural symmetry and compatibility, which can easily lead to increased system viscosity or unstable catalytic activity, making it difficult to achieve a good balance between low odor, low emissions, and high catalytic efficiency.

[0007] Therefore, it is still necessary to develop a novel tertiary amine polyurethane catalyst that simultaneously balances catalytic activity, system compatibility, and migration inhibition capabilities in its structure. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a tertiary amine polyurethane catalyst and its application, particularly relating to a low-odor, low-emission tertiary amine polyurethane catalyst containing a symmetrical biether structure and its application.

[0009] This invention provides a tertiary amine polyurethane catalyst, wherein the general structural formula of the tertiary amine polyurethane catalyst is as follows:

[0010] ;

[0011] Where A is m=1~4; n=1-4; R1 is selected from at least one of C1–C4 alkyl and C4–C5 cycloalkanes, and R2 is selected from at least one of C1–C4 alkyl and C4–C5 cycloalkanes; or R1, R2 and the nitrogen atom to which they are attached together form a 4-6 member nitrogen-containing heterocycle;

[0012] Where B is , , At least one of them; wherein 3 represents a C1–C6 alkyl group.

[0013] Preferably, the A arms are identical and symmetrically distributed.

[0014] Preferably, the tertiary amine polyurethane catalyst is , At least one of them.

[0015] This invention provides an application of the tertiary amine polyurethane catalyst in the preparation of polyurethane foam.

[0016] This invention provides a polyurethane foam, the raw material components of which include polyol, surfactant, isocyanate, and the tertiary amine polyurethane catalyst.

[0017] Preferably, the polyol comprises a polyether polyol; and the surfactant comprises a silicone oil surfactant.

[0018] Preferably, the components, by mass parts, include:

[0019] 100 parts of polyol;

[0020] Surfactant 0.5-5 parts;

[0021] 0.25-0.35 parts of tertiary amine polyurethane catalyst;

[0022] 0-5 parts water;

[0023] 20-80 parts of isocyanate.

[0024] The components also include 0.1-0.5 parts of stannous octoate catalyst.

[0025] This invention provides an application of the polyurethane foam in automotive interiors, furniture, building insulation, and electronic packaging.

[0026] The tertiary amine polyurethane catalyst provided in this invention introduces a symmetrically distributed biether bond structure into the molecule and sets specific end groups capable of forming hydrogen bonds. On the one hand, it maintains the catalytic ability for the isocyanate-hydroxyl reaction through the tertiary amine center; on the other hand, it reduces the volatility and migration of the catalyst in foam through its higher molecular weight, biether-compatible structure, and end-group hydrogen bonding. Combined with BP VWT 709 VOC test results, the compounds IV and V phases of this invention exhibit lower total VOC and amine VOC compared to the traditional A33 catalyst, thereby achieving the technical effects of low odor and low emissions.

[0027] Advantages

[0028] (1) The release of amines from the catalyst of the present invention is significantly reduced, and the source of odor in the product is reduced;

[0029] (2) The catalyst of the present invention has reduced mobility in polyurethane foam, and improved the emission performance of total VOC and amine VOC;

[0030] (3) This invention utilizes the synergistic effect of the tertiary amine catalytic center and the symmetrical diether structure to achieve low odor and low emissions without significantly sacrificing foaming catalytic activity;

[0031] (4) The catalyst of the present invention is applicable to polyurethane foam products with high requirements for odor and emission, such as automotive interiors, furniture, building insulation, and electronic packaging. Detailed Implementation

[0032] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0033] Example 1

[0034]

[0035] A metal catalyst (Ni-Al2O3) was loaded into a continuous reactor. Pyrrole and diethylene glycol (1:1 molar ratio) along with hydrogen were introduced into the reactor. The pressure was controlled at 150 kg. The crude product was separated by distillation to obtain compound I, which was tested by GC and found to have a purity of 98.9%.

[0036] Example 2

[0037]

[0038] A metal catalyst (Ni-Al2O3) was loaded into a continuous reactor. Compound I and liquid ammonia (2:1 molar ratio) along with hydrogen were introduced into the reactor at a pressure of 160 kg. The crude product was separated by distillation to obtain compound II, which was found to have a purity of 98.6% by GC testing.

[0039] Example 3

[0040]

[0041] In a 2L glass reactor, compound II and acrylonitrile were added at room temperature, and the temperature was slowly raised to 50°C. The reaction was carried out at 50-55°C for 3 hours without purification, and the mixture was used as the raw material for the next reaction (containing compound III).

[0042] Example 4

[0043]

[0044] In a 2 L hydrogenation reactor, the product of Example 3, ammonia and Raney cobalt were added, and the temperature was slowly raised to 90°C until no hydrogen was consumed. After filtering the catalyst, the crude product was distilled to obtain compound IV with a purity of 99%.

[0045] Example 5

[0046]

[0047] In a 2 L glass reactor equipped with a reflux condenser, mechanical stirrer, and temperature control sleeve, IV and urea were added. After nitrogen passivation, the temperature was raised to 130 °C. At approximately 100-110 °C, the solid completely dissolved. Nitrogen was used to purge the ammonia generated in the reaction to the acid solution for absorption. The reaction was maintained at 130 °C for 12 hours. After vacuum degassing, the temperature was lowered. NMR showed 3.2% IV, 89.2% V, and 6.2% VI.

[0048] Example 6

[0049] Preparation of flexible polyurethane foam and VOC and odor study

[0050] To investigate the impact of organic amines on foam emissions, a formulation containing low-emission polyols was selected. Total emissions and amine emissions were measured. The formulations used are shown in Table 1.

[0051] Table 1. Flexible foam formulation, by parts by weight

[0052]

[0053] SPECFLEX® NC 630, purchased from Dow Chemical, is a high molecular weight, high functionality, and primary hydroxyl content polyether polyol; TEGOSTAB B8228, purchased from Evonik, is an organosilicon foam stabilizer for polyurethane flexible foam; and KOSMOS 29, purchased from Evonik, is an organotin catalyst.

[0054] Weigh out the polyether polyol, water, TEGOSTAB B8228, amine catalyst and KOSMOS 29 according to the formula in Table 1, place them in a mixing cup at room temperature, and stir at about 1500-2000 r / min for 30-60 s to obtain a uniform polyol premix.

[0055] Add TDI-80 (39.6 parts) quickly to the above premix, stir at a high speed of about 2500-3000 r / min for 10-20 seconds, and immediately pour into a pre-prepared open mold or foaming box for free foaming. After the foam has completed foaming and curing, let it mature at room temperature for at least 24 hours; before testing, cut the sample according to the VOC testing requirements, and test the total VOC and amine VOC according to BP VWT 709 conditions.

[0056] According to BP VWT 709 VOC determination method (30 min, 90 °C) o C) The results of the above foam emission were studied, as shown in Table 2.

[0057] Table 2 Emission Results of Flexible Foam

[0058]

[0059] DABCO®33LV is a 33% solution of triethylenediamine in dipropylene glycol, purchased from Evonik; JEFFCAT®DPA is a reactive gel catalyst, purchased from Huntsman. As shown in Table 2, compared with the conventional A33 catalyst, compounds IV and V of this invention, when used in flexible polyurethane foam, reduced the total VOC to 10 μg / g and 15 μg / g, respectively, with amine VOCs being undetectable and 0.01 μg / g, respectively. Compared with the reactive catalyst DPA, compounds IV and V of this invention also exhibited lower total VOCs. These results demonstrate that the catalyst of this invention can effectively reduce amine release and total volatile emissions in polyurethane foam.

[0060] The odor characteristics of the material were evaluated using the VDA 270 standard method. Specifically, the sample to be tested (preferably a representative sheet or block sample, typically weighing 0.5–5 g or measuring approximately 10 cm × 5 cm) was placed in a clean, dry, and odorless sealed container. The container was then sealed and subjected to heat treatment under constant temperature conditions to allow volatile substances in the sample to be released and stabilized in the sealed space. The heat treatment conditions were 65℃ ± 2℃ for approximately 2 hours. After heat treatment, the container was removed and opened within a specified time. At least three trained evaluators evaluated the odor inside the container by smelling it and scoring it according to an odor intensity grading standard. The grading level is typically divided into 1–6 levels, where level 1 indicates no noticeable odor and level 6 indicates an extremely strong and unacceptable odor. The evaluation result is usually the average score of all evaluators as the final result. When there are large differences in scores among evaluators, repeated testing can be performed to improve the reliability of the results. The above methods can characterize the odor release properties of materials under heated, sealed conditions, thereby evaluating their odor suitability for applications such as automotive interiors. When necessary, the above odor evaluation methods can also be combined with quantitative analysis methods for volatile organic compounds to obtain more comprehensive performance evaluation results.

[0061] Table 3. Odor Evaluation of Polyurethane Foam

[0062]

[0063] Table 3 shows that compounds IV and V involved in this invention exhibit lower odor levels, at 2.22 and 2.67 respectively, both significantly lower than the comparative samples. These results indicate that compounds IV and V possess superior low-odor performance under the same testing conditions, effectively reducing the odor release intensity of materials under heating conditions. Therefore, they are more suitable for applications with high odor requirements, such as polyurethane material systems for automotive interiors.

[0064] This invention effectively reduces the release of volatile amines or their odor intensity through molecular structure design, thereby significantly improving the sensory properties of the material. Therefore, the compounds of this invention are particularly suitable for applications with strict requirements on odor and volatile organic compound emissions, including but not limited to polyurethane foam materials for automotive interiors.

Claims

1. A tertiary amine polyurethane catalyst, characterized in that, The general structural formula of the tertiary amine polyurethane catalyst is: ； Where A is m=1~4; n=1-4; R1 is selected from at least one of C1–C4 alkyl and C4–C5 cycloalkanes, and R2 is selected from at least one of C1–C4 alkyl and C4–C5 cycloalkanes; or R1, R2 and the nitrogen atom to which they are attached together form a 4-6 member nitrogen-containing heterocycle; Where B is , , At least one of them; wherein 3 represents a C1–C6 alkyl group.

2. The tertiary amine polyurethane catalyst according to claim 1, characterized in that, The A arms are identical and symmetrically distributed.

3. The tertiary amine polyurethane catalyst according to claim 1, characterized in that, The tertiary amine polyurethane catalyst is , At least one of them.

4. The use of the tertiary amine polyurethane catalyst of claim 1 in the preparation of polyurethane foam.

5. A polyurethane foam, characterized in that, The raw material components include polyols, surfactants, isocyanates, and the tertiary amine polyurethane catalyst as described in claim 1.

6. The polyurethane foam according to claim 5, characterized in that, The polyol includes polyether polyol; the surfactant includes silicone oil surfactant.

7. The polyurethane foam according to claim 5, characterized in that, By mass parts, the components include 100 parts of polyol; Surfactant 0.5-5 parts; 0.25-0.35 parts of tertiary amine polyurethane catalyst; 0-5 parts water; 20-80 parts of isocyanate.

8. The polyurethane foam according to claim 7, characterized in that, The components also include 0.1-0.5 parts of stannous octoate catalyst.

9. The application of the polyurethane foam of claim 5 in the fields of automotive interiors, furniture, building insulation, and electronic packaging.

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