CN108912599B

CN108912599B - Filter film obtained by compounding nitrile rubber and phenolic resin

Info

Publication number: CN108912599B
Application number: CN201810670458.6A
Authority: CN
Inventors: 冯俊山; 刘冬梅; 冯笑男
Original assignee: Changchun Fengtai Automobile Rubber Industry Co ltd
Current assignee: CHANGCHUN FENGTAI AUTOMOBILE RUBBER INDUSTRY Co.,Ltd.
Priority date: 2018-06-26
Filing date: 2018-06-26
Publication date: 2020-12-25
Anticipated expiration: 2038-06-26
Also published as: CN108912599A

Abstract

The invention relates to the field of automobile filters, in particular to a filter film obtained by compounding nitrile rubber and phenolic resin. The filter film is obtained by compounding raw materials including nitrile rubber and phenolic resin; the weight ratio of the nitrile rubber to the phenolic resin is 1: (1.5-2). The prepared filter film has small shrinkage rate before and after curing when in use, is favorable for adjusting the fine size of the film, simultaneously has the mechanical properties of the impact strength of nitrile rubber, the shear strength, the peel strength and the like of phenolic resin, and particularly can overcome the difficulty that the mechanical properties of the shear strength, the peel strength and the like and the impact strength cannot be simultaneously obtained by adopting the filter film obtained by modifying the phenolic resin by the method provided by the invention.

Description

Filter film obtained by compounding nitrile rubber and phenolic resin

Technical Field

The invention relates to the field of automobile filters, in particular to a filter film obtained by compounding nitrile rubber and phenolic resin.

Background

According to the relevant data of automobile industry yearbook, 879.15 thousands of automobiles are sold in China in 2007, the automobile output and sales volume in 2008 breaks through 900 thousands, and the automobile sales scale in 2010 reaches 1263 thousands. Under the condition of high-speed market scale growth of the automobile industry, the filter industry in China faces important opportunities as a main matching industry of the automobile industry.

The engine has three filters of air, engine oil and fuel oil, which are generally called as 'three filters'. They are responsible for filtering the media in the engine intake system, lubrication system and combustion system, respectively. The filter is originally through the filtration to harmful impurity, makes the engine can normally work under various operating modes to can reach the life of regulation. When the product with unqualified original filtering efficiency is used, dust and impurities harmful to the engine cannot be effectively filtered, the early abrasion of the engine of the motor vehicle can be caused, the service life is shortened, and the engine is damaged or even accidents are caused. There are two main reasons for filter failure: firstly, the quality of the main raw material filter paper used for manufacturing the filter is not good, the aperture is too large, the thickness is uneven, or the folding number of the filter paper is too small, the folding width is too small, and the filter paper cannot play the due filtering role, or the strength of the filter paper is too low, and the filter paper is broken after the air effect of a certain flow, so that the filtering efficiency is greatly reduced. Secondly, the gluing process in the production is not well mastered, or the quality of the gluing agent is not good, so that the filter paper and the end cover cannot keep a sealing state, and dust flows through gaps. The selection and processing technology of the filter paper and the gluing technology of the filter paper are two key quality control points in the production flow of the filter. Some manufacturers purchase cheaper unqualified filter paper and adhesive in order to reduce production cost, or have short bonding time, less or uneven brushing of adhesive and the like, which causes unqualified original filtering efficiency.

Particularly for the air filter, the used adhesive takes epoxy resin as a main raw material, the adhesive is a liquid adhesive, the adhesive needs to be fully stirred before use, and the operation is carried out by adopting a dipping method, a spraying method, a brush coating method, a roll coating method, a transfer method and other methods, so the process is complicated, and the phenomena of uneven adhesive distribution, waste and the like are easy to occur; moreover, the adhesive is brittle after curing, is not impact resistant, and is easily damaged during subsequent processing, transportation and installation, resulting in a short filter life.

In addition, with the rapid development of the rubber industry, rubber composite materials are widely applied, the quality of an adhesive is the key of the quality of a composite product in a rubber and metal composite product, and the requirements on the adhesive technology are more and more strict with the increase of the types of the composite products and the expansion of the application field. The traditional techniques such as chlorinated rubber method and isocyanate method can not meet new requirements, and new adhesives are needed to improve the quality of rubber composite products.

Disclosure of Invention

In order to solve the technical problems, the invention provides a filter film in a first aspect, wherein the filter film is prepared by compounding raw materials including nitrile rubber and phenolic resin; the weight ratio of the nitrile rubber to the phenolic resin is 1: (1.5-2).

As a preferred technical solution, the phenolic resin is a modified phenolic resin.

As a preferable technical scheme, the preparation raw material of the modified phenolic resin comprises a functional monomer; the functional monomer molecule contains a multi-ring structure.

As a preferred embodiment, the functional monomer is selected from the group consisting of 2-chloro-4- (trifluoromethyl) phenyl isocyanate, 3- (trifluoromethyl) -4-methylphenyl isocyanate, 5-tert-butyl-3-isoxazolyl isocyanate, 2- (2-thienyl) ethyl isocyanate, 4-isobutoxybenzyl isocyanate, 4-butyl-2-methylphenyl isocyanate, 2,6, 6-tetramethylpiperidin-4-yl isocyanate, cyclohexyl isocyanate, 4- (hexyloxy) phenyl isocyanate, 4- (octyloxy) phenyl isocyanate, 4- (trifluoromethyl) benzyl isocyanate, 3, 5-bis (trifluoromethyl) phenyl isocyanate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, ethyl methacrylate, propyl methacrylate, 2-phenethyl isocyanate and 5-methyl-2- (trifluoromethyl) -3-furyl isocyanate.

As a preferable technical scheme, the weight of the functional monomer accounts for 4-8 wt% of the weight of the modified phenolic resin.

As a preferable technical scheme, the raw material for preparing the modified phenolic resin further comprises a crosslinking monomer.

As a preferable technical scheme, the crosslinking monomer contains ether oxygen bonds in molecules.

As a preferred technical scheme, the crosslinking monomer is 2-methylpropane-2-enoyl isocyanate or 3-ethoxy-2-acryloyl isocyanate.

As a preferable technical scheme, the raw materials for preparing the filter rubber sheet further comprise an anti-aging agent, a vulcanizing agent, an accelerator, a curing agent and an auxiliary agent.

As a preferable technical scheme, the weight ratio of the crosslinking monomer to the functional monomer is (1-2.2): 1.

the second aspect of the invention provides the use of the filter film as described above in the field of automotive filters.

Has the advantages that: compared with the prior art, the filter rubber sheet prepared by the invention has good dimensional stability, and the shrinkage rate of the rubber sheet before and after curing is very small during use, thereby being beneficial to adjusting the fine size of the rubber sheet. The filter film is prepared by compounding the raw materials of the nitrile rubber and the phenolic resin according to a certain weight ratio, and has the mechanical properties of the impact strength of the nitrile rubber, the shear strength of the phenolic resin, the peel strength and the like, particularly, the filter film obtained by modifying the phenolic resin by the method provided by the invention can overcome the difficulty that the mechanical properties of the shear strength, the peel strength and the like and the impact strength cannot be simultaneously obtained, and the obtained filter film has good impact resistance and excellent mechanical properties of the shear strength, the peel strength and the like. Secondly, the applicant finds that the filter rubber sheet prepared from the functional monomer and the crosslinking monomer provided by the application has good heat and humidity aging performance, is not easy to swell or hydrolyze in a high-temperature and humidity environment, can keep good mechanical performance, and has long service life.

Detailed Description

In order to make the technical solution of the present invention clearer, the technical solution provided by the present invention is further explained by the following embodiments.

It is to be understood that the terms "preferred," "preferably," "more preferred," and the like in the context of this invention, refer to embodiments of the invention that may provide certain benefits, under certain circumstances. However, other embodiments may be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the invention.

In order to solve the technical problems in the prior art, the invention provides a filter film in a first aspect, wherein the filter film is prepared by compounding nitrile rubber and phenolic resin; the weight ratio of the nitrile rubber to the phenolic resin is 1: (1.5-2); preferably, the weight ratio of the nitrile rubber to the phenolic resin is 1: 1.8.

the nitrile-butadiene rubber (NBR) is a rubber polymer prepared by butadiene and acrylonitrile through an emulsion polymerization method, and the NBR has better oil resistance and wider use temperature due to the cyano group contained in the molecular chain structure, but has poor use performance under acid gasoline and high-temperature environment for a long time and poor dimensional stability under high temperature. The nitrile rubber has good elasticity and toughness due to the flexible linear molecular chain structure, and the cyano group on the acrylonitrile has good resistance to media such as water, organic solvents, oil and the like, and the polarity of the cyano group is relatively large, so that the nitrile rubber is beneficial to improving the compatibility between the nitrile rubber and other organic resins (phenolic resins). The more the content of acrylonitrile, the better the oil resistance, stability, tensile strength and the like of the rubber, but the worse the cold resistance, toughness and the like.

In a preferred embodiment, the nitrile rubber is nitrile rubber with an acrylonitrile content of 28-35%.

The phenolic resin is also called bakelite, also called bakelite powder, and is prepared by polycondensation of phenol and formaldehyde under the condition of catalyst, neutralization and water washing, and its specific gravity is about 1.7 on average, and it is easily soluble in alcohol, insoluble in water and stable to water, weak acid and weak base solution. The thermoplastic phenolic resin and the thermosetting phenolic resin can be prepared by regulating and controlling the molar ratio of the phenol to the formaldehyde and the parameters of the catalyst such as the class, the dosage and the like. The molecular chain of the linear thermoplastic phenolic resin has hydroxyl, and can be crosslinked and cured through intermolecular dehydration condensation, but small molecular compounds can be generated in the condensation curing process, so that the formed phenolic resin material is easy to shrink due to volatilization at high temperature, the dimensional stability is poor, the condensation curing process is easy to carry out particularly in a high-temperature environment, and the material has larger shrinkage and poor dimensional stability along with the process.

In the process of reducing the curing size stability of the phenolic resin, the inventor modifies the phenolic resin by adopting isocyanate ethyl acrylate (CAS: 13641-96-8) or isocyano ethyl methacrylate (CAS: 30674-80-7), introduces high-temperature reactive double bond groups on polymer molecules, replaces the traditional condensation curing mode of the phenolic resin, and crosslinks double bonds on the polymer at high temperature to cure and form the phenolic resin. Although the dimensional stability of the phenolic resin material obtained by this method is certainly greatly changed at the time of curing, the aging properties, particularly the aging properties and chemical stability under a high humidity environment, are yet to be further improved, and the applicant speculates that hydrolysis is likely to occur under a high humidity environment, particularly when the environmental temperature is relatively high, due to the introduction of an ester group into the modified phenolic resin molecule, causing a change in the dimensions of the material structure, thereby causing deterioration of the product properties.

In one embodiment, the phenolic resin is a modified phenolic resin; preferably, the raw materials for preparing the modified phenolic resin comprise functional monomers; the functional monomer molecule contains a multi-ring structure; preferably, the functional monomer contains a halogen group thereon; further preferably, the halogen group is selected from a fluorine, chlorine or bromine group. The polycyclic structure may be a benzene ring, a cyclopentyl group, a furan group, a thiophene group, a morpholine group, a piperidine group, or the like.

The applicant finds that a certain amount of functional monomers with polycyclic groups are introduced into the side chain of the phenolic resin molecule, so that the heat resistance of the phenolic resin film can be improved to a certain extent, and the phenolic resin film still has excellent mechanical properties at high temperature. The applicant has also found that when the functional monomer with polycyclic group also contains halogen element (especially fluorine), the performances of high temperature resistance, humidity resistance, solvent resistance and the like are improved obviously, which is probably because fluorine atom has larger electron-withdrawing effect and the bond length of C-F bond is shorter, which can form better shielding effect to C-C bond, and is beneficial to improving the performances of oil resistance, solvent resistance, high temperature resistance and the like of the phenolic resin film.

In the prior art, in order to improve the properties of the phenolic resin, such as strength, adhesion, high temperature resistance and the like, an active group with high rigidity is often introduced into a phenolic resin molecular chain, so that the mobility of the polymer molecular chain at high temperature is reduced, and the activation energy for the migration of the polymer molecular chain is improved. However, the film obtained by the method has the advantages that the flexibility of polymer molecular chains is reduced, the capability of the polymer for changing conformation is weakened, the phenolic resin becomes very brittle after being cured, the impact resistance of the material is greatly influenced, and other mechanical properties are improved by sacrificing the impact resistance of the phenolic resin material. In the invention, the applicant unexpectedly discovers that after the functional monomer with a specific functional group is adopted, the dosage of the functional monomer is regulated and controlled, and the dosage of the nitrile rubber, the curing agent, the curing accelerator and other components compounded with the phenolic resin is adopted, the filter rubber sheet has good mechanical property, and meanwhile, the impact resistance of the filter rubber sheet is not obviously changed, so that the filter rubber sheet with good mechanical property and impact resistance is successfully obtained.

The adhesive used on the filter component is required to have higher strength, cohesiveness, flexibility, impact strength and other properties in the working environment of a three-filter component in engine equipment, so that a functional monomer capable of reacting with the hydroxyl active group on the molecular chain skeleton of the phenolic resin, such as a compound containing carboxyl, isocyanate, acyl chloride and other groups, is introduced to change the aggregation structure of the phenolic resin polymer, and improve the cohesiveness, the impact strength and other properties of the phenolic resin polymer.

In a preferred embodiment, the functional monomer is selected from the group consisting of 2-chloro-4- (trifluoromethyl) phenyl isocyanate, 3- (trifluoromethyl) -4-methylphenyl isocyanate, 5-tert-butyl-3-isoxazolyl isocyanate, 2- (2-thienyl) ethyl isocyanate, 4-isobutoxybenzyl isocyanate, 4-butyl-2-methylphenyl isocyanate, 2,6, 6-tetramethylpiperidin-4-yl isocyanate, cyclohexyl isocyanate, 4- (hexyloxy) phenyl isocyanate, 4- (octyloxy) phenyl isocyanate, 4- (trifluoromethyl) benzyl isocyanate, 3, 5-bis (trifluoromethyl) phenyl isocyanate, mixtures thereof, and mixtures thereof, One or more of 2-phenylethyl isocyanate, 5-methyl-2- (trifluoromethyl) -3-furyl isocyanate; preferably, the functional monomer is selected from one or more of 4-isobutoxy benzyl isocyanate, 4- (trifluoromethyl) benzyl isocyanate, 3, 5-bis (trifluoromethyl) phenyl isocyanate and 5-methyl-2- (trifluoromethyl) -3-furyl isocyanate; further preferably, the functional monomer is 5-methyl-2- (trifluoromethyl) -3-furyl isocyanate or 3, 5-bis (trifluoromethyl) phenyl isocyanate.

The applicant finds that the dosage of the functional monomer in the process of preparing the modified phenolic resin has very obvious influence on the change of various properties of the final modified phenolic resin. When the dosage of the functional monomer is excessive, the filter rubber sheet obtained by compounding the obtained phenolic resin and the nitrile rubber becomes brittle, the impact resistance is seriously reduced, and the viscosity of the system is easily too high and the system is thickened too early in the process of preparing the modified phenolic resin, so that the further modification is difficult to carry out. Secondly, the applicant finds that when the amount of the functional monomer is too much, the performances of the obtained filter film such as high temperature resistance, strength and the like are not improved, but are reduced. The possible reasons are that the excessive use of the functional monomer causes poor compatibility among components such as phenolic resin, nitrile rubber and the like in the system, the polymers are not tightly accumulated enough when the obtained filter film is cured and molded, an inhomogeneous aggregation state is formed, a stress concentration area appears in the film, and various performances of the filter film are influenced. When the dosage of the functional monomer is too small, the improvement effect on the performance of the filter film cannot be shown.

In a preferred embodiment, the weight of the functional monomer accounts for 4-8 wt% of the weight of the modified phenolic resin; preferably, it is 7 wt%.

The working environment temperature of air, engine oil and fuel filter components in engine equipment is higher, and the requirements on high temperature resistance, dimensional stability and the like of the components are also higher. Therefore, hydroxyl active groups on the molecular chain skeleton of the phenolic resin are utilized to introduce monomers capable of being crosslinked with the generating molecules, and the original condensation curing type of the phenolic resin is changed, so that the filter rubber sheet is prevented from being greatly shrunk in size during curing. In an embodiment of the present invention, the raw material for preparing the modified phenolic resin further includes a crosslinking monomer.

In one embodiment, the crosslinking monomer contains an ether oxygen bond in the molecule; preferably, the crosslinking monomer has an unsaturated double bond together with an ether oxygen bond. (the ether oxygen bond is formed by replacing hydrogen in hydroxyl of alcohol or phenol by alkyl, and has a general formula of R-O-R ', wherein R and R' can be the same or different.)

In addition, since the crosslinking monomer needs to be introduced into the molecular chain of the phenolic resin polymer and is mainly fixed by reacting with the hydroxyl group on the molecular chain of the phenolic resin, the molecule of the crosslinking monomer needs to have an active group capable of reacting with the hydroxyl group, such as carboxyl, isocyanate, acid chloride, and the like. In the present invention, a crosslinking monomer having an isocyanate group in the molecular chain is preferably used. Preferably, the crosslinking monomer is 2-methylpropan-2-enoyl isocyanate (CAS number: 4474-60-6) or 3-ethoxy-2-acryloyl isocyanate (CAS number: 928778-13-6).

In a preferred embodiment, the preparation method of the modified phenolic resin comprises the following steps:

(1) mixing functional monomer and dibutyltin dilaurate, adding organic solvent (such as DMF, DMSO, DMAc, trichloromethane, dichloromethane, tetrahydrofuran, hexafluoroisopropanol, etc.) for dissolving, and preparing into 0.12g/ml solution;

(2) dissolving phenolic resin in an organic solvent at 80 ℃, then dripping the solution obtained in the step (1) at the speed of 0.4ml/min, stirring for 10min, and heating to 90 ℃ for reaction for 1-2 hours;

(3) and (3) cooling the solution system obtained in the step (2) to 70 ℃, adding a crosslinking monomer, stirring for reacting for 3 hours, cooling to room temperature, concentrating, filtering, and drying to obtain the modified phenolic resin.

The phenolic resin can be selected from the conventional linear bisphenol A phenolic resin on the market, for example, the bisphenol A phenolic resin with the weight average molecular weight of 800-2500 and the hydroxyl equivalent weight of 115-125 can be selected. The organic solvent is not particularly limited, and a conventional solvent, such as an aprotic organic solvent, e.g., DMF, DMAc, acetone, DMSO, dichloromethane, trichloromethane, or the like, may be used. And the dibutyltin dilaurate is used as a catalyst to promote the reaction between the modified monomer and hydroxyl on the molecular chain of the phenolic resin, and the using amount of the dibutyltin dilaurate in the reaction is 0.1-0.3% of the using amount of the phenolic resin.

The applicant found that it is important to control the dropping speed of the functional monomer when it is dropped into the phenolic resin solution, and that when the dropping speed is too fast, the mechanical properties (such as shear strength, peel strength, impact strength, etc.) of the resulting filter sheet may be reduced, possibly because the dropping speed may affect the dispersion of the functional monomer in the phenolic resin solution, affect the uniformity of the reaction thereof, etc. The applicant finds that the filter rubber sheet prepared from the phenolic resin modified by the method can obviously reduce the dosage of auxiliary agents such as curing agent, accelerator, anti-aging agent and the like. When the amount of the auxiliary agent is large in the filter film, a stress concentration area is formed in the material, a mechanical weak point is formed, and the mechanical properties, the stability and other characteristics of the film are reduced.

In one embodiment, the weight ratio of the crosslinking monomer to the functional monomer is (1-2.2): 1; preferably, the weight ratio of the crosslinking monomer to the functional monomer is 1.8: 1.

in one embodiment, the raw materials for preparing the filter rubber sheet further comprise an anti-aging agent, a vulcanizing agent, an accelerator, a curing agent and an auxiliary agent.

In the present invention, the antioxidant is not particularly limited, and examples thereof include amine-ketone compounds, imidazole compounds, amine compounds, phenol compounds, sulfur compounds, phosphorus compounds, and the like; preferably, the anti-aging agent is ODA (4,4' -dioctyl diphenylamine).

In the invention, the vulcanizing agent can be sulfur, thiuram, resin vulcanizing agent and the like; preferably, sulfur is used as the vulcanizing agent.

The promotion in the present invention is an auxiliary additive for promoting reaction curing, shortening curing time or not affecting curing performance at low temperature curing. In one embodiment of the invention, the curing accelerator is selected from one or more of fatty amine accelerator, acid anhydride accelerator, polyether amine catalyst, latent catalyst; preferably, the curing accelerator is selected from one or more of 2,4, 6-tris (dimethylaminomethyl) phenol, triethanolamine, N-dimethylaniline, 1, 8-diazabicycloundecen-7-ene, diethylthiourea, dipropanol, bis (thiocarbonyldimethylamine) disulfide, diphenylhydroxyethyl-3-quinuclidine ester, zinc diethyldithiocarbamate, N-cyclohexyl-2-benzothiazolesulfenamide, 2-mercaptobenzothiazole, dibenzothiazole disulfide; more preferably, the curing accelerator is 2-mercaptobenzothiazole and dibenzothiazyl disulfide; further preferably, the weight ratio of the 2-mercaptobenzothiazole to the dibenzothiazyl disulfide is (1.2-4: 1); still further preferably, the weight ratio is 2.5: 1.

the curing agent in the present invention is a substance capable of further reacting with the phenolic resin polymer to cure and mold the phenolic resin polymer. In one embodiment, the curing agent is selected from one or more of epoxide addition polyamines, aromatic amine curing agents, dicyandiamide, aliphatic amines, imidazole derivatives. Examples of the aliphatic amine curing include vinyl triamine, aminoethyl piperazine, hexamethylenetetramine, ethylenediamine, diaminocyclohexane, triethylenetetramine, dipropylenetriamine, trimethylhexamethylenediamine, and diethylamine; examples of the aromatic amine curing agent include m-phenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, and dibenzylamine ether; preferably, the curing agent is hexamethylenetetramine.

Applicants have found that the incorporation of a certain amount of dicumyl peroxide (DCP) into the curing agent increases the degree of crosslinking of the polymer in the system, and therefore the addition of 4% by weight of dicumyl peroxide to the curing agent is combined with dicumyl peroxide to provide the hexamethylenetetramine curing agent.

In the present invention, the auxiliary is not particularly limited, and may be stearic acid, a metal oxide (e.g., zinc stearate), or the like.

In order to make the technical solution provided by the present invention clearer, the technical solution of the present invention is further explained by the following specific examples.

Examples

Example 1

Embodiment 1 provides a filter film prepared by compounding nitrile rubber and phenolic resin; the raw materials for preparing the filter rubber sheet comprise, by weight, 15 parts of nitrile rubber, 27 parts of modified phenolic resin, 0.3 part of 2-mercaptobenzothiazole, 0.12 part of dibenzothiazyl disulfide, 0.12 part of sulfur, 0.15 part of stearic acid, 0.15 part of zinc stearate, 0.27 part of antioxidant ODA, 2.5 parts of hexamethylenetetramine and 0.1 part of dicumyl peroxide.

The nitrile rubber is nitrile-41 rubber which is purchased from Lanzhou petrochemical company of China under the trademark N21; the preparation method of the modified phenolic resin comprises the following steps:

(1) mixing 1.2g of functional monomer and 0.03g of dibutyltin dilaurate, adding trichloromethane for dissolving, and preparing a solution of 0.12 g/ml;

(2) taking 17g of linear bisphenol A phenolic resin, dissolving the linear bisphenol A phenolic resin in 120ml of trichloromethane at the temperature of 80 ℃, then dripping the solution obtained in the step (1) at the speed of 0.4ml/min, stirring for 10min, and heating to 90 ℃ to react for 1.5 hours;

(3) and (3) cooling the solution system obtained in the step (2) to 70 ℃, adding 2.16g of crosslinking monomer, stirring for reaction for 3 hours, cooling to room temperature, concentrating, filtering and drying to obtain the modified phenolic resin.

The functional monomer is 5-methyl-2- (trifluoromethyl) -3-furyl isocyanate (CAS: 306935-03-5); the crosslinking monomer is 3-ethoxy-2-acryloyl isocyanate (CAS number: 928778-13-6).

Example 2

Embodiment 2 provides a filter film prepared by compounding nitrile rubber and phenolic resin; the raw materials for preparing the filter rubber sheet comprise, by weight, 15 parts of nitrile rubber, 27 parts of modified phenolic resin, 0.3 part of 2-mercaptobenzothiazole, 0.12 part of dibenzothiazyl disulfide, 0.12 part of sulfur, 0.15 part of stearic acid, 0.15 part of zinc stearate, 0.27 part of antioxidant ODA, 2.5 parts of hexamethylenetetramine and 0.1 part of dicumyl peroxide.

The functional monomer is 5-methyl-2- (trifluoromethyl) -3-furyl isocyanate; the crosslinking monomer is 2-methylpropane-2-enoyl isocyanate (CAS number: 4474-60-6).

Example 3

Embodiment 3 provides a filter film prepared by compounding nitrile rubber and phenolic resin; the raw materials for preparing the filter rubber sheet comprise, by weight, 15 parts of nitrile rubber, 27 parts of modified phenolic resin, 0.3 part of 2-mercaptobenzothiazole, 0.12 part of dibenzothiazyl disulfide, 0.12 part of sulfur, 0.15 part of stearic acid, 0.15 part of zinc stearate, 0.27 part of antioxidant ODA, 2.5 parts of hexamethylenetetramine and 0.1 part of dicumyl peroxide.

The functional monomer is 3, 5-bis (trifluoromethyl) phenyl isocyanate (CAS: 16588-74-2); the crosslinking monomer is 3-ethoxy-2-acryloyl isocyanate (CAS number: 928778-13-6).

Example 4

Embodiment 4 provides a filter film prepared by compounding nitrile rubber and phenolic resin; the raw materials for preparing the filter rubber sheet comprise, by weight, 15 parts of nitrile rubber, 22.5 parts of modified phenolic resin, 0.3 part of 2-mercaptobenzothiazole, 0.12 part of dibenzothiazyl disulfide, 0.12 part of sulfur, 0.15 part of stearic acid, 0.15 part of zinc stearate, 0.27 part of antioxidant ODA, 2.5 parts of hexamethylenetetramine and 0.1 part of dicumyl peroxide.

Example 5

Embodiment 5 provides a filter film prepared by compounding nitrile rubber and phenolic resin; the raw materials for preparing the filter film comprise, by weight, 15 parts of nitrile rubber, 30 parts of modified phenolic resin, 0.3 part of 2-mercaptobenzothiazole, 0.12 part of dibenzothiazyl disulfide, 0.12 part of sulfur, 0.15 part of stearic acid, 0.15 part of zinc stearate, 0.27 part of antioxidant ODA, 2.5 parts of hexamethylenetetramine and 0.1 part of dicumyl peroxide.

Example 6

Embodiment 6 provides a filter film prepared by compounding nitrile rubber and phenolic resin, which is different from embodiment 1 in that the preparation method of the modified phenolic resin comprises the following steps:

(1) mixing 0.7g of functional monomer and 0.03g of dibutyltin dilaurate, adding trichloromethane for dissolving, and preparing a solution of 0.12 g/ml;

(3) and (3) cooling the solution system obtained in the step (2) to 70 ℃, adding 1.26g of crosslinking monomer, stirring for reacting for 3 hours, cooling to room temperature, concentrating, filtering, and drying to obtain the modified phenolic resin.

Example 7

Embodiment 7 provides a filter rubber sheet prepared by compounding nitrile rubber and phenolic resin, which is different from embodiment 1 in that the amount of the functional monomer is not changed, but the weight ratio of the crosslinking monomer to the functional monomer is 1: 1.

example 8

Embodiment 8 provides a filter film prepared by compounding nitrile rubber and phenolic resin, which is different from embodiment 1 in that the amount of the functional monomer is not changed, but the weight ratio of the crosslinking monomer to the functional monomer is 2.2: 1.

example 9

Embodiment 9 provides a filter film obtained by compounding nitrile rubber and phenolic resin, which is different from embodiment 1 in that the preparation raw materials of the filter film comprise, by weight, nitrile rubber 15, modified phenolic resin 27, 2-mercaptobenzothiazole 0.15, dibenzothiazyl disulfide 0.12, sulfur 0.12, stearic acid 0.15, zinc stearate 0.15, antioxidant ODA 0.27, hexamethylenetetramine 2.5, and dicumyl peroxide 0.1.

Example 10

Embodiment 10 provides a filter film obtained by compounding nitrile rubber and phenolic resin, which is different from embodiment 1 in that the preparation raw materials of the filter film comprise, by weight, nitrile rubber 15, modified phenolic resin 27, 2-mercaptobenzothiazole 0.48, dibenzothiazyl disulfide 0.12, sulfur 0.12, stearic acid 0.15, zinc stearate 0.15, antioxidant ODA 0.27, hexamethylenetetramine 2.5, and dicumyl peroxide 0.1.

Comparative example 1

Comparative example 1 provides a filter sheet compounded from a composition comprising nitrile rubber and phenolic resin, which is different from example 1 in that an unmodified bisphenol a phenolic resin was used, and was obtained from the national trade company of dongpo, national trade, jiang yin, under the designation DPS-2110.

Comparative example 2

Comparative example 2 provides a filter rubber sheet prepared by compounding nitrile rubber and phenolic resin, which is different from example 1 in that the preparation method of the modified phenolic resin comprises the following steps:

(3) and (3) cooling the solution system obtained in the step (2) to 70 ℃, preserving heat, stirring for 3 hours, cooling to room temperature, concentrating, filtering and drying to obtain the modified phenolic resin.

The functional monomer is 5-methyl-2- (trifluoromethyl) -3-furyl isocyanate (CAS: 306935-03-5).

Comparative example 3

Comparative example 3 provides a filter rubber sheet prepared by compounding nitrile rubber and phenolic resin, which is different from example 1 in that the preparation method of the modified phenolic resin comprises the following steps:

(1) taking 17g of linear bisphenol A phenolic resin, dissolving the linear bisphenol A phenolic resin in 120ml of trichloromethane at the temperature of 80 ℃, then adding 0.03g of dibutyltin dilaurate, stirring for 10min, and heating to 90 ℃ for reaction for 1.5 hours;

(2) and cooling the system to 70 ℃, adding 2.16g of crosslinking monomer, stirring for reaction for 3 hours, cooling to room temperature, concentrating, filtering and drying to obtain the modified phenolic resin.

The crosslinking monomer is 3-ethoxy-2-acryloyl isocyanate (CAS number: 928778-13-6).

Comparative example 4

Comparative example 4 provides a filter rubber sheet obtained by compounding nitrile rubber and phenolic resin as raw materials, which is different from example 1 in that the weight ratio of the functional monomer to the crosslinking monomer in the preparation method of the modified phenolic resin is 1: 5, the weight of the functional monomer is 1.2 g.

Comparative example 5

Comparative example 5 provides a filter rubber sheet obtained by compounding nitrile rubber and phenolic resin as raw materials, which is different from example 1 in that the weight ratio of the functional monomer to the crosslinking monomer in the preparation method of the modified phenolic resin is 1: 0.2, the weight of the functional monomer is 1.2 g.

Comparative example 6

Comparative example 6 provides a filter rubber sheet prepared by compounding nitrile rubber and phenolic resin, which is different from example 1 in that the weight of the functional monomer in the preparation method of the modified phenolic resin is 4.25 g.

Comparative example 7

Comparative example 7 provides a filter film obtained by compounding nitrile rubber and phenolic resin, which is different from example 1 in that the filter film is prepared from raw materials including, by weight, nitrile rubber 3, modified phenolic resin 27, 2-mercaptobenzothiazole 0.3, dibenzothiazyl disulfide 0.12, sulfur 0.12, stearic acid 0.15, zinc stearate 0.15, an anti-aging agent ODA 0.27, hexamethylenetetramine 2.5, and dicumyl peroxide 0.1.

Comparative example 8

Comparative example 8 provides a filter rubber sheet compounded from materials including nitrile rubber and phenolic resin, which is different from example 1 in that the crosslinking monomer is ethyl isocyanate acrylate (CAS: 13641-96-8).

Performance testing

1. Mixing the preparation raw materials of the filter rubber sheet provided by the application by a mixing roll in a conventional manner, discharging the mixture into a mold with a specific size, curing the mixture at 100 ℃ for 10min, then carrying out heat treatment at 250 ℃ for 2min, and measuring the average size shrinkage (%) of the obtained rubber block before and after curing.

2. The filter rubber sheet provided by the application is bonded on a 45# steel plate, is cured for 10min at 100 ℃, is subjected to heat treatment for 2min at 250 ℃, and is then tested for peel strength and shear strength before and after being placed in a constant temperature and humidity box with the temperature of 150 ℃ and the humidity of 90% for 2 hours, wherein the peel strength test is carried out according to the method of the national standard GB/T7760-.

3. Mixing the raw materials for preparing the filter rubber sheet provided by the application by a mixing roll in a conventional manner, cutting the mixture into specific sizes, and carrying out notch impact resistance test on the rubber sheet provided by the application according to the GB/T1043 + 1993 standard.

TABLE 1 Performance test Table

As can be seen from Table 1, the filter film provided by the invention has low shrinkage rate when cured and good dimensional stability in the use process. Meanwhile, the filter rubber sheet has good mechanical properties such as shear strength, peel strength, impact strength and the like, and the filter rubber sheet prepared by compounding the modified phenolic resin and a certain amount of nitrile rubber has good damp-heat aging performance, can be normally used in a high-temperature and humid environment, and the comprehensive performance of the rubber sheet cannot be greatly influenced.

Finally, it should be understood that the above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The filter film is characterized by being prepared by compounding raw materials including nitrile rubber and phenolic resin; the weight ratio of the nitrile rubber to the phenolic resin is 1: (1.5-2);

the phenolic resin is modified phenolic resin;

the preparation raw material of the modified phenolic resin comprises a functional monomer;

the raw materials for preparing the modified phenolic resin also comprise a crosslinking monomer;

the crosslinking monomer is 2-methyl-2-acryloyl isocyanate or 3-ethoxy-2-acryloyl isocyanate;

the functional monomer is selected from 2-chloro-4- (trifluoromethyl) phenyl isocyanate, 3- (trifluoromethyl) -4-methylphenyl isocyanate, 5-tert-butyl-3-isoxazolyl isocyanate, 2- (2-thienyl) ethyl isocyanate, 4-isobutoxybenzyl isocyanate, 4-butyl-2-methylphenyl isocyanate and cyclohexyl isocyanate, 4- (hexyloxy) phenyl isocyanate, 4- (octyloxy) phenyl isocyanate, 4- (trifluoromethyl) benzyl isocyanate, 3, 5-bis (trifluoromethyl) phenyl isocyanate, 2-phenylethyl isocyanate, 5-methyl-2- (trifluoromethyl) -3-furyl isocyanate.

2. The filter film of claim 1, wherein the weight of the functional monomer is 4 to 8 wt% of the weight of the modified phenolic resin.

3. The filter film of claim 1, wherein the raw materials for preparing the filter film further comprise an anti-aging agent, a vulcanizing agent, an accelerator, a curing agent and an auxiliary agent.

4. Use of a filter film according to any of claims 1 to 3 in the field of automotive filters.