CN107868195B

CN107868195B - Preparation method of cyclohexene modified resorcinol-formaldehyde resin

Info

Publication number: CN107868195B
Application number: CN201711144151.4A
Authority: CN
Inventors: 潘琳琳; 吕寻伟; 马松; 李云峰
Original assignee: Shandong Yanggu Huatai Chemical Co Ltd
Current assignee: Shandong Yanggu Huatai Chemical Co Ltd
Priority date: 2017-11-17
Filing date: 2017-11-17
Publication date: 2020-02-07
Anticipated expiration: 2037-11-17
Also published as: CN107868195A

Abstract

The invention relates to a preparation method of cyclohexene modified phenolic resin, which comprises the following steps: step 1: heating and melting resorcinol, adding cyclohexene under the condition of acid catalysis, and fully reacting the cyclohexene with the resorcinol in an amount which is 50-70% of the total amount of the cyclohexene to obtain a polymerization solution 1; the molar ratio of resorcinol to the total amount of cyclohexene is 1: 0.5 to 1; step 2: dropwise adding the rest cyclohexene into the polymerization solution 1 in sequence, and carrying out polymerization reaction with formaldehyde to obtain a polymerization solution 2; the molar ratio of the resorcinol to the formaldehyde is 1: 0.3 to 0.8; and step 3: adding a terminating agent into the polymerization solution 2, stirring, heating, raising the temperature, carrying out reduced pressure distillation under a vacuum condition, and obtaining the residue after the distillation is finished, namely the product of the invention. The product obtained by the invention is the phenolic reinforced resin for rubber with low content of free phenol, has proper softening point and good reactivity, and improves the crosslinking reaction density of a resin network in the vulcanization process.

Description

Preparation method of cyclohexene modified resorcinol-formaldehyde resin

Technical Field

The invention belongs to the technical field of high polymer materials, and particularly belongs to a preparation method of cyclohexene modified resorcinol-formaldehyde resin.

Background

The hardness and elastic modulus of natural rubber and synthetic rubber (such as styrene butadiene rubber, nitrile butadiene rubber and the like) are low, and the requirements of practical application cannot be met. The hardness and the elastic modulus of the rubber can be improved by filling a large amount of carbon black in the rubber material, but certain rubber components such as tire apex require high rubber material hardness, too much carbon black is filled to cause large processing difficulty and very difficult tire molding. The improved method is that the thermoplastic phenolic resin is added into the rubber compound, and before vulcanization, the resin plays a role of a plasticizer in the rubber compound, so that the rubber compound is convenient to mix and process; in the vulcanization process, the resin and the rubber are vulcanized together to form a resin network and rubber network interpenetrating network system, and the aim of reinforcing the rubber material is fulfilled by utilizing the rigidity of the phenolic network and the interpenetrating superposition of the two networks.

The existing phenolic resin for rubber reinforcement comprises unmodified phenolic resin, cashew nut oil modified phenolic resin, tall oil modified phenolic resin, phenol modified phenolic resin and cyclohexene modified phenolic resin. The unmodified resin has large polarity, high water absorption and poor compatibility with rubber, and a resin area with high local concentration is easily formed in a rubber material, so that a good reinforcing effect cannot be achieved. In the prior art, the cyclohexene-modified resorcinol-formaldehyde resin has very low content of free resorcinol, and is not easy to generate smoke phenomenon, but the reaction activity is obviously reduced, the firmness of the formed network is far lower than that of the network constructed by resorcinol monomers in situ, and the product performance is obviously reduced.

Disclosure of Invention

The preparation method of cyclohexene modified resorcinol-formaldehyde resin provided by the invention can be used for improving the crosslinking reaction density of a resin network in the vulcanization process while keeping the low smoke generation characteristic of the resin at the rubber mixing temperature, thereby improving the performance of alkylated resorcinol resin in the prior art.

The invention discloses a preparation method of cyclohexene modified phenolic resin, which is characterized by comprising the following steps:

step 1: heating and melting 1 part of resorcinol at the temperature of 100-160 ℃, adding cyclohexene under the acid catalysis condition, and fully reacting the cyclohexene with the resorcinol, wherein the used amount accounts for 50-70% of the total amount of the cyclohexene to obtain a polymerization solution 1; wherein the mol ratio of resorcinol to cyclohexene is 1: 0.5 to 1;

step 2: dropwise adding the rest cyclohexene into the polymerization solution 1 in sequence, and carrying out polymerization reaction with formaldehyde at the reaction temperature of 120 ℃ and 150 ℃ for 1-2h to obtain a polymerization solution 2; wherein the molar ratio of the resorcinol to the formaldehyde is 1: 0.3 to 0.8;

and step 3: adding a terminator into the polymerization solution 2, stirring, heating to 140-160 ℃, carrying out reduced pressure distillation under the vacuum condition, wherein the distillation temperature is 140-.

Further, the heating melting temperature of the resorcinol in the step 1 is 110-.

Further, cyclohexene and resorcinol in the step 1 are reacted for 40-60 min.

Further, in the acid catalysis conditions in the step 1, the acid catalyst is p-toluenesulfonic acid, and the dosage is as follows: p-toluenesulfonic acid: the mass ratio of the resorcinol is 1-10 ‰:1, selecting the mass ratio of 4-6 per mill: 1.

further, the formaldehyde used in the step 2 is a 37% formaldehyde aqueous solution.

Further, the terminating agent in the step 3 is a sodium hydroxide aqueous solution, the mass fraction is 40%, and the use amount is as follows: sodium hydroxide: the mol ratio of the resorcinol is 0.5-0.8 ‰: 1.

the invention has the beneficial effects that:

the cyclohexene modified resorcinol-formaldehyde resin has the following advantages:

1. the cyclohexene-modified resorcinol-formaldehyde resin has low content of free phenol, hardly generates smoke in the rubber mixing process, reduces the smoke to a great extent compared with the prior phenolic resin, does not damage the human health, and avoids environmental pollution.

2. The cyclohexene modified resorcinol-formaldehyde resin has high reaction activity, good thermal stability and good product performance.

3. The cyclohexene raw material has low price, greatly reduces the cost of the resorcinol-formaldehyde resin, and improves the market competitiveness of the product.

The cyclohexene-modified resorcinol-formaldehyde resin is a phenolic reinforced resin for rubber with low content of free phenol, and has a proper softening point and good reactivity; the low fuming characteristic of the resin is ensured at the rubber mixing temperature, and the crosslinking reaction density of a resin network in the vulcanization process is improved, so that the performance of the alkylated resorcinol resin is obviously improved. Meanwhile, the cyclohexene price is relatively low, so that the cost of the adhesive resin is reduced, and the market competitiveness is enhanced.

Detailed Description

The invention is further illustrated by the following specific examples.

In the examples, the aqueous solution of formaldehyde was 37% by mass, and the sodium hydroxide solution was 40% by mass. Other raw materials used in the examples are all commercial products. The "%" is mass percent.

Example 1

Step 1: adding 110.0g of resorcinol and 0.55g of p-toluenesulfonic acid into a 500ml four-neck flask provided with a stirrer, a reflux condenser and a dropping funnel, heating to 110-; obtaining a polymerization solution 1;

step 2: heating the polymerization solution 1 to 130 ℃, slowly dropwise adding 16.4g of cyclohexene and 40.5g of formaldehyde aqueous solution, and finishing dropping within 40 min; after the dropwise addition is finished, the reaction is carried out for 1h under the condition of heat preservation; obtaining a polymerization solution 2 after the reaction is finished;

and step 3: adding 0.35g of sodium hydroxide aqueous solution into the polymerization solution 2, stirring for 20min, and finishing the reaction; heating to 140 ℃, and starting reduced pressure distillation under the vacuum degree of-0.85 MPa, wherein the residual solution is the cyclohexene-modified resorcinol-formaldehyde resin after distillation of the fraction is stopped. The resin obtained in this example was tested for softening point of 102.2 ℃ and free resorcinol content of 0.95%.

Example 2

Step 1: adding 110.0g of resorcinol and 0.88g of p-toluenesulfonic acid into a 500ml four-neck flask provided with a stirrer, a reflux condenser and a dropping funnel, heating to 100 ℃ and 120 ℃ for melting, then dropwise adding 34.4g (0.42mol) of cyclohexene, and carrying out heat preservation and reflux reaction for 55 min; obtaining a polymerization solution 1;

step 2: heating the polymerization solution 1 to 145 ℃, slowly dropwise adding 23.0g of cyclohexene and 48.5g of formaldehyde aqueous solution, and finishing dropping within 50 min; after the dropwise addition, the reaction was carried out for 1.5h under heat preservation. Obtaining a polymerization solution 2 after the reaction is finished;

and step 3: adding 0.4g of sodium hydroxide aqueous solution into the polymerization solution 2, stirring for 25min, and finishing the reaction; heating to 150 ℃, and starting reduced pressure distillation under the vacuum degree of 0.5MPa, wherein the residual solution is the cyclohexene-modified resorcinol-formaldehyde resin after distillation of the fraction is stopped. The resin obtained in this example was tested for softening point 106.5 ℃ and free resorcinol content 1.12%.

Example 3

Step 1: adding 110.0g of resorcinol and 1.10g of p-toluenesulfonic acid into a 500ml four-neck flask provided with a stirrer, a reflux condenser and a dropping funnel, heating to 130-160 ℃ for melting, then dropwise adding 42.3g (0.6mol) of cyclohexene, and carrying out heat preservation and reflux reaction for 60 min; obtaining a polymerization solution 1;

step 2: heating the polymerization solution 1 to 120 ℃, slowly dropwise adding 22.7g of cyclohexene and 60g of formaldehyde aqueous solution, and finishing dropping within 60 min; after the dropwise addition, the reaction is carried out for 2 hours under the condition of heat preservation. Obtaining a polymerization solution 2 after the reaction is finished;

and step 3: 0.2g of an aqueous sodium hydroxide solution was added to the polymerization solution 2, and the mixture was stirred for 30min to terminate the reaction. Heating to 160 ℃, and starting reduced pressure distillation under the vacuum degree of 1.0MPa, wherein the residual solution is the cyclohexene-modified resorcinol-formaldehyde resin after distillation of the fraction is stopped. The resin obtained in this example was tested for softening point 100.7 ℃ and free resorcinol content 1.52%.

The application performance of the cyclohexene modified resorcinol-formaldehyde resin obtained by the invention is tested as follows:

the test formula is as follows:

raw material name and brand	Amount of formulation per part by mass phr
		National standard natural rubber SCR5#	100
Carbon black N330 as reinforcing agent	55
		Active agent pre-dispersed zinc oxide master colloidal particle ZnO-80	10
P-phenylenediamine anti-aging agent 4020	2
		Adhesion promoter pre-dispersed master colloidal particle HMMM-55	6.5
Pre-dispersed masterbatch DZ-80 of vulcanization accelerator	1.5
		Vulcanizing agent pre-dispersed masterbatch particle HDOT20-80	5.5
Products obtained in the examples	1.5

The test process comprises the following steps: three-stage rubber mixing process is adopted, wherein one stage and two stages are carried out in an internal mixer, and the three stages are carried out in an open mill.

Through the above tests, the following test data were obtained:

TABLE 1160 deg.C vulcanization characteristic data

TABLE 2127 ℃ Mooney scorch data

TABLE 3 tensile stress strain Properties

TABLE 4 rubber to Steel wire adhesion

As can be seen from tables 1, 2, 3 and 4, the cyclohexene-modified resorcinol-formaldehyde resin prepared by the invention has the same application performance in rubber as the resorcinol-formaldehyde resin in the prior art, but the raw material price of the invention is low, and the market competitiveness of the product is strong.

Claims

1. The preparation method of the cyclohexene modified phenolic resin is characterized by comprising the following steps:

step 2: dropwise adding the rest cyclohexene into the polymerization solution 1 in sequence, and carrying out polymerization reaction with all formaldehyde at the reaction temperature of 120-150 ℃ for 1-2h to obtain a polymerization solution 2; wherein the molar ratio of the resorcinol to the formaldehyde is 1: 0.3 to 0.8;

2. The method for preparing cyclohexene modified phenolic resin as claimed in claim 1, wherein the heating melting temperature of resorcinol in step 1 is 110-130 ℃.

3. The method for preparing cyclohexene modified phenolic resin according to claim 1, wherein the reaction time of cyclohexene and resorcinol in step 1 is 40-60 min.

4. The method for preparing cyclohexene modified phenolic resin according to claim 1, wherein the acid catalysis condition in step 1 is that p-toluenesulfonic acid is used as an acid catalyst, and the dosage is as follows: p-toluenesulfonic acid: the mass ratio of the resorcinol is 1-10 ‰: 1.

5. the method for preparing cyclohexene modified phenolic resin according to claim 1, wherein the formaldehyde used in step 2 is 37% formaldehyde aqueous solution.

6. The method for preparing cyclohexene modified phenolic resin according to claim 1, wherein the terminating agent in step 3 is sodium hydroxide aqueous solution, the mass fraction is 40%, and the use amount is as follows: sodium hydroxide: the mol ratio of the resorcinol is 0.5-0.8 ‰: 1.

7. the method for preparing cyclohexene-modified phenolic resin according to claim 4, wherein the ratio of p-toluenesulfonic acid: the mass ratio of the resorcinol is 4-6 per mill: 1.