阅读说明：本技术 一种分子量高度可控的酚醛树脂及其制备方法和应用 (Phenolic resin with highly controllable molecular weight, and preparation method and application thereof ) 是由 张洁 王光辉 纪爱亮 王文芳 张�成 董栋 张宁 于 2021-08-09 设计创作，主要内容包括：本申请涉及光刻胶技术领域,具体公开了一种分子量高度可控的酚醛树脂及其制备方法和应用。所述制备方法包括如下步骤：制备步骤：在惰性气氛下,甲基苯酚类化合物和醛类化合物在酸性催化剂、水存在下发生反应,得到反应液；脱水脱酚步骤：首先采用水对反应液进行水洗处理并分出水相,重复水洗处理,直至所分出的水相pH=6.5～7；然后在35～80℃温度下进行干燥,得到酚醛树脂。所述分子量高度可控的酚醛树脂是由上述制备方法制备而成。所述分子量高度可控的酚醛树脂在制备光刻胶中的应用。本申请在同一反应条件下达到高度控制酚醛树脂的分子量和软化点的目的,保证酚醛树脂的分子量和软化点稳定。(The application relates to the technical field of photoresist, and particularly discloses a phenolic resin with a highly controllable molecular weight, and a preparation method and application thereof. The preparation method comprises the following steps: the preparation method comprises the following steps: reacting a methylphenol compound and an aldehyde compound in the presence of an acid catalyst and water under an inert atmosphere to obtain a reaction solution; and (3) dehydrating and dephenolizing: firstly, washing the reaction solution with water, separating out a water phase, and repeating the washing until the pH of the separated water phase is = 6.5-7; and then drying at the temperature of 35-80 ℃ to obtain the phenolic resin. The phenolic resin with the highly controllable molecular weight is prepared by the preparation method. The application of the phenolic resin with highly controllable molecular weight in preparing photoresist. The method achieves the aim of highly controlling the molecular weight and the softening point of the phenolic resin under the same reaction condition, and ensures that the molecular weight and the softening point of the phenolic resin are stable.)

1. A preparation method of a phenolic resin with highly controllable molecular weight is characterized by comprising the following steps:

the preparation method comprises the following steps: reacting a methylphenol compound and an aldehyde compound in the presence of an acid catalyst and water in an inert atmosphere to obtain a reaction solution;

and (3) dehydrating and dephenolizing: firstly, washing the reaction solution with water, separating out a water phase, and repeating the washing until the pH of the separated water phase is = 6.5-7; and then drying at the temperature of 35-80 ℃ to obtain the phenolic resin.

2. The preparation method according to claim 1, wherein the pH of the water phase separated from the last water washing treatment is = 6.7-7.

3. The method according to claim 1, wherein the drying temperature is 40 to 60 ℃.

4. The method according to claim 1, wherein the molar ratio of the methylphenol compound to the aldehyde compound is 1 (0.5-1).

5. The method according to claim 1, wherein the methylphenol-based compound is at least one compound selected from the group consisting of 2-methylphenol, 3-methylphenol, 4-methylphenol, 2, 3-dimethylphenol, 2, 4-dimethylphenol, 2, 5-dimethylphenol, 2, 6-dimethylphenol, 3, 5-dimethylphenol, 2,3, 5-trimethylphenol and 3,4, 5-trimethylphenol.

6. The method according to claim 1, wherein the aldehyde compound is at least one selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, and butyraldehyde.

7. The method according to claim 1, wherein the acidic catalyst is at least one selected from the group consisting of p-toluenesulfonic acid, dodecylbenzenesulfonic acid, hydrochloric acid, sulfuric acid and oxalic acid.

8. The method according to claim 1, wherein the reaction temperature is 70 to 100 ℃ and the reaction time is 1 to 7 hours.

9. A phenol resin having a highly controllable molecular weight, which is produced by the production method according to any one of claims 1 to 8.

10. Use of a highly molecular weight controlled phenolic resin according to claim 9 in the preparation of a photoresist.

Technical Field

The application relates to the technical field of photoresist, in particular to a phenolic resin with highly controllable molecular weight, a preparation method and an application thereof.

Background

Semiconductors are widely used in various fields of the present society. In the development of semiconductor technology, photoresists play a crucial role, even called "rare earths in the semiconductor industry".

The main components of the photoresist formulation are resin, sensitizer, solvent and additives. The resin is the most central component in the photoresist formula, and the characteristics of the photoresist, such as the adhesiveness, the film thickness and the like, are mainly determined by the resin. The purity requirement of the photoresist on raw materials is an electronic grade, but the stability of the resin is poor, and the molecular structure is easily changed under the influence of the outside, so that the development difficulty of the photoresist is high.

Among them, the electronic grade phenolic resin is widely used in LCD photoresist, PCB photoresist and semiconductor photoresist because of the characteristics of no swelling, strong plasma etching resistance, high temperature resistance, good resolution, fast alkali dissolution rate and the like in the photoresist developing process. However, in actual production, the softening points and the molecular weights of phenolic resins in different batches of the same formula are greatly different, and even the phenolic resins in the same reaction kettle have different molecular weights due to sequential discharging.

Disclosure of Invention

In order to achieve the purpose of highly controlling the molecular weight and the softening point of the phenolic resin under the same reaction condition and ensure the stability of the molecular weight and the softening point of the phenolic resin, the application provides the phenolic resin with highly controllable molecular weight and a preparation method and application thereof.

In a first aspect, the present application provides a method for preparing a phenolic resin with a highly controllable molecular weight, which adopts the following technical scheme:

a preparation method of a phenolic resin with highly controllable molecular weight comprises the following steps:

the preparation method comprises the following steps: reacting a methylphenol compound and an aldehyde compound in the presence of an acid catalyst and water in an inert atmosphere to obtain a reaction solution;

and (3) dehydrating and dephenolizing: firstly, washing the reaction solution with water, separating out an aqueous phase, and repeating the washing until the pH value of the separated aqueous phase is 6.5-7; and then drying at the temperature of 35-80 ℃ to obtain the phenolic resin.

Optionally, the pH of the water phase separated from the last water washing treatment is 6.8-7. Preferably, the pH of the water phase separated from the last water washing treatment is 6.9-7. Most preferably, the pH of the aqueous phase separated from the last water wash treatment is 7.

Optionally, the drying temperature is 40-60 ℃. Preferably, the drying temperature is 40-55 ℃. More preferably, the temperature of the drying is 40-45 ℃. Most preferably, the temperature of the drying is 40 ℃.

Alternatively, the drying may be carried out at atmospheric pressure or under vacuum, for example at a vacuum of-0.095 MPa.

Wherein drying generally means that the water content of the resulting phenolic resin is less than 1 wt%.

Optionally, the water used in the water washing treatment is deionized water. Preferably, the water used for the water washing treatment is water with the temperature of 60-70 ℃. More preferably, the water used for the water washing treatment is deionized water at 60-70 ℃.

Optionally, the molar ratio of the methylphenol compound to the aldehyde compound is 1 (0.5-1). Preferably, the molar ratio of the methylphenol compound to the aldehyde compound is 1 (0.63-0.9). More preferably, the molar ratio of the methylphenol compound to the aldehyde compound is 1 (0.63 to 0.83). More preferably, the molar ratio of the methylphenol compound to the aldehyde compound is 1 (0.63-0.73). Still more preferably, the molar ratio of the methylphenol compound to the aldehyde compound is 1: 0.63. Most preferably, the molar ratio of the methylphenol compound to the aldehyde compound is 1: 0.73.

Optionally, the methylphenol compound is at least one selected from the group consisting of 2-methylphenol, 3-methylphenol, 4-methylphenol, 2, 3-dimethylphenol, 2, 4-dimethylphenol, 2, 5-dimethylphenol, 2, 6-dimethylphenol, 3, 5-dimethylphenol, 2,3, 5-trimethylphenol and 3,4, 5-trimethylphenol. Preferably, the methylphenol-based compound is at least two selected from the group consisting of 2-methylphenol, 3-methylphenol, 4-methylphenol, 2, 3-dimethylphenol, 2, 4-dimethylphenol, 2, 5-dimethylphenol, 2, 6-dimethylphenol, 3, 5-dimethylphenol, 2,3, 5-trimethylphenol and 3,4, 5-trimethylphenol. More preferably, the methylphenol-based compound is at least three selected from the group consisting of 2-methylphenol, 3-methylphenol, 4-methylphenol, 2, 3-dimethylphenol, 2, 4-dimethylphenol, 2, 5-dimethylphenol, 2, 6-dimethylphenol, 3, 5-dimethylphenol, 2,3, 5-trimethylphenol and 3,4, 5-trimethylphenol.

Optionally, the methylphenol compound is at least one selected from the group consisting of 3-methylphenol, 4-methylphenol, 2, 3-dimethylphenol, 3, 5-dimethylphenol and 2,3, 5-trimethylphenol. Preferably, the methylphenol compound is at least two selected from the group consisting of 3-methylphenol, 4-methylphenol, 2, 3-dimethylphenol, 3, 5-dimethylphenol, and 2,3, 5-trimethylphenol. The methylphenol compound is at least three selected from 3-methylphenol, 4-methylphenol, 2, 3-dimethylphenol, 3, 5-dimethylphenol and 2,3, 5-trimethylphenol.

Optionally, the aldehyde compound is at least one selected from formaldehyde, acetaldehyde, propionaldehyde and butyraldehyde. Preferably, the aldehyde compound is formaldehyde.

Optionally, the acidic catalyst is at least one selected from p-toluenesulfonic acid, dodecylbenzenesulfonic acid, hydrochloric acid, sulfuric acid and oxalic acid. Preferably, the acidic catalyst is at least one selected from p-toluenesulfonic acid and oxalic acid.

Optionally, the reaction temperature is 70-100 ℃, and the reaction time is 1-7 hours.

In a second aspect, the present application provides a phenolic resin with highly controllable molecular weight, which adopts the following technical scheme: the phenolic resin with the highly controllable molecular weight is prepared by the preparation method.

In a third aspect, the application provides a use of a phenolic resin with a highly controllable molecular weight in the preparation of a photoresist.

Optionally, the photoresist is an LCD photoresist, a PCB photoresist, or a semiconductor photoresist.

In summary, the present application has the following beneficial effects:

first, the applicant found that "water washing first and then low temperature dehydration" in the dehydration and dephenolization step of the phenolic resin can successfully solve the technical problems to be solved by the present application, and achieve the technical effect of highly controlling the molecular weight and softening point of the phenolic resin.

Secondly, the drying temperature of 40-60 ℃ is preferably selected in the application, so that the controllability of the molecular weight of the phenolic resin can be further enhanced.

Detailed Description

In the actual production of the electronic grade phenolic resin, the softening point and the molecular weight of the phenolic resin in different reaction kettles with the same formula are greatly different, and even the molecular weight of the phenolic resin in the same reaction kettle is different due to the sequential discharging. In order to solve this problem, the present applicant has conducted extensive studies on the synthesis process of a phenol resin, and as a result, found that a main factor causing uncontrollable molecular weight is the dehydration dephenolation step.

Based on the discovery, the applicant researches which factors directly influence the stability of the molecular weight of the phenolic resin in the dehydration and dephenolization step, and further, the applicant discovers that the alkylation reaction and the rearrangement reaction can simultaneously occur in the dehydration and dephenolization stage at the temperature of 150 ℃ and 230 ℃ in the dehydration and dephenolization step, and the two reactions are mutually restricted; wherein, the molecular weight of the phenolic resin increases with the time of alkylation reaction, and the rearrangement reaction is intensified with the increase of dehydration temperature and gradually takes the leading reaction. As a result, the applicant has found that "water washing first and then low-temperature dewatering" of the phenolic resin in the dewatering and dephenolizing step can successfully solve the technical problems to be solved by the present application and achieve the technical effect of highly controlling the molecular weight and softening point of the phenolic resin. In addition, the controllability of the molecular weight of the phenolic resin can be further enhanced by adopting a proper low-temperature drying temperature (for example, 40-60 ℃). The present application has been made based on the above findings.

The present application will be described in further detail with reference to examples and comparative examples.

The sources of the raw materials used in the following examples and comparative examples are shown in table 1.

TABLE 1 sources of raw materials

Raw materials	Source
		2-methylphenol	Group of traditional Chinese medicines
3-methylphenol	Group of traditional Chinese medicines
		4-methylphenol	Group of traditional Chinese medicines
3, 5-methylphenol	Group of traditional Chinese medicines
		2, 3-dimethylphenol	Group of traditional Chinese medicines
2, 5-dimethylphenol	Group of traditional Chinese medicines
		2,3, 5-trimethylphenol	Group of traditional Chinese medicines
P-toluenesulfonic acid	Aladdin reagent
		Oxalic acid	Aladdin reagent
37% by mass of formaldehyde	Group of traditional Chinese medicines
		50% by mass of formaldehyde	Group of traditional Chinese medicines
Toluene	Aladdin reagent

The performance detection method of the phenolic resin comprises the following steps:

(1) softening point: the softening point of the phenolic resin is determined by using an FP900 heat value analysis system according to the standard ASTM D3461-97 (2007);

(2) weight average molecular weight: using a Waters1515 separation unit, a Waters2414 differential detector, molecular weight was measured according to GB/T27843-2011 (mobile phase: tetrahydrofuran; flow rate: 1.0 mL/min; sample injection volume: 30. mu.L; sample run time: 35 minutes);

(3) content of free phenol: 2996PPA using waters high Performance liquid chromatography (mobile phase: tetrahydrofuran + water + methanol; flow rate: 1.0 mL/min; temperature: 30 ℃; column: waters ssunfiec 18, 250 mm. times.4.6 mm), microsyringe: and (5) sampling by an automatic sampler.

Table 2 mobile phase gradient elution program list

Time (minutes)	Tetrahydrofuran (volume percent concentration)	Water (volume percent concentration)	Methanol (volume percent concentration)
				0.01	6.0	15.0	79.0
4.00	18.0	9.0	73.0
				20.00	25.0	5.0	70.0
40.00	33.0	0.0	67.0
				50.00	33.0	0.0	67.0
52.00	6.0	15.0	79.0
				60.00	6.0	15.0	79.0

Preparation and performance detection of (I) phenolic resin

The preparation method of the phenolic resin specifically comprises the following steps:

the preparation method comprises the following steps: adding 2-methylphenol, 3-methylphenol, 2, 3-dimethylphenol, p-toluenesulfonic acid and water into a 1000mL four-neck flask with a stirring device, a thermometer and a reflux condenser under the protection of nitrogen, and heating to 90 ℃; slowly dripping formaldehyde, and finishing dripping within 60 minutes; then refluxing and reacting for 3 hours to obtain reaction liquid after the reaction is finished, monitoring and sampling to detect the weight average molecular weight M of the phenolic resin_w-1；

And (3) dehydrating and dephenolizing: firstly, washing the reaction solution with water at 60 ℃, separating out a water phase, and repeating the washing treatment until the pH value of the separated water phase is 7; then transferring the reaction liquid to a low-temperature drying device, and carrying out vacuum drying and dehydration for 15 hours under the conditions of vacuum degree of-0.095 MPa and 50 ℃ to obtain phenolic resin; and the weight average molecular weight M of the phenolic resin was measured_w-2Softening point and free phenol content.

Calculating the change rate Y of the weight average molecular weight of the phenolic acid resin before and after the dehydration dephenolization step, wherein the calculation formula of the change rate Y is as follows:

examples 1 to 5

In examples 1 to 5, the methylphenol compound is a mixture of 2-methylphenol, 3-methylphenol and 2, 3-dimethylphenol in a molar ratio of 1:1: 1; in addition, in examples 1 to 5, the molar ratio of the methylphenol compound to formaldehyde was changed while keeping the methylphenol compound unchanged.

Table 3 dosage table and performance test results of phenolic resin in examples 1-5

As can be seen from Table 3, the weight average molecular weights of the phenolic resins of examples 1-5 before and after the dehydration dephenolization step do not change much, so that the preparation method provided by the application can achieve the purpose of highly controlling the molecular weight and the softening point of the phenolic resin. Wherein the molar ratio of the methylphenol compound to formaldehyde in example 1 is 1:0.63, and the molar ratio of the methylphenol compound to formaldehyde in example 3 is 1:0.73, the change rate Y of the weight average molecular weight of the phenolic acid resin before and after the dehydration dephenolation step can be made to be less than 1%.

Comparative example 1

Comparative example 1 compared to example 5, except that: comparative example 1 the reaction solution was directly distilled in the dehydration dephenolization at a distillation temperature of 220 c for 150 minutes to obtain a phenol resin.

As a result, it was found that the phenolic resin of comparative example 1 had a local gelation phenomenon, which was caused by the phenolic resin being locally excessively heated.

Example 6

Compared to example 3, the difference is: example 6 the reaction solution obtained in the preparation step was divided into eight parts in the dehydration and dephenolization step, and the pH values of the aqueous phases separated in the last water washing treatment of the eight parts of the reaction solution in the dehydration and dephenolization step were different.

Table 4 example 6 measurement of properties of phenolic resin

As can be seen from Table 4, the pH value of the water phase separated by the last water washing treatment in the dehydration and dephenolization step is 6.5-7, and the change rate Y of the weight average molecular weight of the phenolic resin before and after the dehydration and dephenolization step is small; furthermore, the pH value of the separated water phase in the last washing treatment is 6.7-7, so that the change rate Y is less than 1%; and the closer the pH value of the water phase separated by the last water washing treatment is to 7, the smaller the change rate Y of the weight average molecular weight of the phenolic resin before and after the dehydration and dephenolization steps. This indicates that the change in the weight average molecular weight of the phenolic resin under acidic conditions is large.

Example 7

Compared to example 3, the difference is: in the dehydration and dephenolization step of example 7, sampling was monitored and the molecular weight of the phenolic resin was measured at various drying points, starting from the drying condition of the earliest reaching of a vacuum degree of-0.095 MPa and a temperature of 50 ℃.

Comparative example 2

Compared to example 3, the difference is: comparative example 2 the reaction solution was directly distilled in the dehydration dephenolization step at a distillation temperature of 220 c, starting from the earliest attainment of the distillation temperature, samples were taken and the molecular weight of the phenolic resin was monitored at different distillation time points.

Comparative example 3

Compared to example 3, the difference is: comparative example 3 in the dehydration dephenolization step, the reaction solution was not washed with water and directly vacuum dried under the conditions of a vacuum degree of-0.095 MPa and a temperature of 50 ℃, and samples were monitored and the molecular weights of the phenolic resins at different drying time points were measured, with the earliest reaching of the vacuum drying conditions as the starting point.

TABLE 5 monitoring of the weight average molecular weight of the phenolic resin in the dehydration dephenolation step in example 7 and comparative examples 2 to 3

Weight average molecular weight of phenolic resin at different time points	30 minutes	60 minutes	90 minutes	150 minutes	300 minutes
						Example 7	8201	8205	8211	8213	8219
Comparative example 2	8456	8637	8902	11025	Occurrence of gel phenomenon
						Comparative example 3	8255	8298	8364	8389	8450

As can be seen from Table 5, the change of the weight average molecular weight of the phenolic resin in the dehydration and dephenolization steps of example 7 with time is very small, which shows that the weight average molecular weight of the phenolic resin discharged in the same reaction kettle in sequence is almost unchanged, and the stable performance of the phenolic resin product is ensured.

However, comparative examples 2 to 3 have a large change in the weight average molecular weight of the phenol resin with time in the dehydration dephenolation step. Among them, the phenolic resin in comparative example 2 undergoes a severe rearrangement reaction due to a long-term high-temperature distillation, and a gelation phenomenon occurs even when the distillation time exceeds 150 minutes, and the molecular weight of the phenolic resin is sharply increased, thereby resulting in uncontrollable molecular weight of the phenolic resin; the phenolic resin in the comparative document 3 is also reacted during the low-temperature drying process due to the acidic pH and the presence of free phenol, resulting in an increase in the molecular weight of the phenolic resin. Therefore, the water washing treatment in the dehydration and dephenolization step plays an important role in controlling the weight average molecular weight of the phenolic resin.

Example 8

Compared to example 3, the difference is: example 8 the reaction solution obtained in the preparation step was divided into ten parts on average, and the drying temperatures of the ten parts of the reaction solution in the dehydration and dephenolization step were different.

Table 6 results of performance test of the phenolic resin of example 8

As can be seen from table 6, by integrating the change rate of the weight average molecular weight of the phenolic resin and the content of the free phenol in the phenolic resin, the drying temperature in the present application is preferably 40 to 60 ℃, and more preferably 40 to 55 ℃, which not only can ensure the controllability of the molecular weight of the phenolic resin, but also can ensure that the content of the free phenol in the phenolic resin is low.

Preparation and performance detection of (II) phenolic resin

TABLE 7 formulation tables for phenolic resins of example 9 and comparative example 4

Example 9

Example 9 the procedure was repeated three times and the preparation of the phenolic resin specifically included the following steps:

the preparation method comprises the following steps: adding 3-methylphenol, 4-methylphenol, oxalic acid and water into a 1000mL four-neck flask with a stirring device, a thermometer and a reflux condenser under the protection of nitrogen, and heating to 95 ℃; slowly dripping formaldehyde, finishing dripping within 60 minutes, and then carrying out reflux reaction for 2 hours; then adding 3, 5-dimethylphenol, continuing reflux reaction for 2 hours, and monitoring and sampling to detect the weight average molecular weight Mw-1 after the reaction is finished;

and (3) dehydrating and dephenolizing: washing the reaction solution with 250mL of 70 ℃ deionized water, and separating to remove the water phase; repeating the water washing step until the pH value of water carried in the reaction solution is 6.5-7; then transferring the reaction liquid to a low-temperature drying device, and carrying out vacuum drying and dehydration for 13 hours under the conditions of vacuum degree of-0.095 MPa and 60 ℃ to obtain phenolic resin; and the weight average molecular weight Mw-2, the softening point and the content of free phenol of the phenolic resin are detected.

Comparative example 4

Comparative example 4 the operation was repeated twice, and compared with example 9, except that: comparative example 4 in the dehydration dephenolization step, the reaction solution was directly distilled at 220 ℃ for 30min to obtain a phenol resin.

Table 8 results of performance test of the phenolic resins provided in example 9 and comparative example 4

As can be seen from table 8, in example 9, three experiments are repeated, and similar experimental results are obtained in the three experiments, so that the preparation method of the phenolic resin provided by the present application has good reproducibility, and the uniform performance of the phenolic resin produced in different reaction kettles using the same formulation can be ensured.

However, in the step of dehydrating and dephenolizing in comparative example 4, the conventional distillation method was adopted, and the reproducibility of the experimental results was not good due to the severe rearrangement reaction and alkylation reaction of the phenolic resin during the dehydration and the removal of free phenol, and the phenomenon of unsmooth distillation caused by the entrapment of moisture in the phenolic resin.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.